1,919 results on '"spacer"'
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52. Oxidation of Alloy X-750 with Low Iron Content in Simulated BWR Environment.
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Tuzi, Silvia, Stiller, Krystyna, and Thuvander, Mattias
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INCONEL ,BOILING water reactors ,IRON ,METALLIC oxides ,OXIDATION ,ELECTRON microscopy ,WATER jets - Abstract
This paper presents an investigation of the oxidation of Alloy X-750 containing 5 wt% iron in a simulated boiling water reactor (BWR) environment. The specimens were exposed by a water jet (10 m/s) at 286 °C for durations ranging from 2 to 840 h, and the development of the oxide microstructure was mainly studied using electron microscopy. The results showed that the oxide scale consists of blocky crystals of trevorite on top of a porous inner layer rich in Ni and Cr. After the longest exposure time, the trevorite crystals completely covered the specimen surface. The study further revealed that the rate at which the oxide grew and the metal dissolved both decreased with time, and the metal thinning process appeared to be sub-parabolic. Given the significant variation in iron content in the X-750 specification, the influence of this element on the material's corrosion performance in BWR was examined by comparing the results from this investigation with those from previous work on material containing 8 wt% Fe. The study demonstrates that the oxide growth, metal dissolution and metal thinning were slower in the material with a higher iron content, indicating the importance of this element in limiting the degradation of Alloy X-750 in BWR environments. [ABSTRACT FROM AUTHOR]
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- 2023
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53. Strukturiertes Vorgehen bei infizierter Prothese.
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Scharf, Markus, Schraag, Amadeus Dominik, Ehrnsperger, Marianne, and Grifka, Joachim
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Copyright of Zeitschrift für Rheumatologie is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)
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- 2023
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54. Preparation and Characterization of Organosiloxanes with A Liquid Crystalline Trans-4-Pentylcyclohexanoate Moiety.
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LI-CHUAN WU and CHIH-HUNG LIN
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SILOXANES ,POLYMER liquid crystals ,LIQUID crystal states ,NUCLEAR magnetic resonance spectroscopy ,SILICONES ,LIQUID crystals ,TRANSITION temperature ,DOUBLE bonds - Abstract
In the course of this research, we successfully created three series of liquid crystalline compounds featuring the trans-cyclohexane structure. One series of compounds featured a double bond at the terminal position of the molecules, whereas the remaining two series incorporated disiloxane and trisiloxane groups. Each series comprised five spacers of different lengths, specifically 3, 4, 5, 6, and 11 methylene units. We identified the structures of the synthesized compounds using Nuclear Magnetic Resonance spectroscopy and characterized their liquid crystalline behavior through thermal analysis and polarized optical microscopy. The results revealed that both the length of the spacer and the presence of siloxane groups significantly influenced the liquid crystal phase transitions, transition temperatures, and temperature ranges. These findings provide valuable insights for designing and developing new liquid crystal materials with tailored properties for various applications. [ABSTRACT FROM AUTHOR]
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- 2023
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55. The Effect of Bottom Reinforcement Spacers on Reinforced Concrete Structures Loaded by Explosion.
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Zezulová, Eva, Dubec, Branislav, Dvořák, Petr, Fládr, Josef, and Cibulová, Klára
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REINFORCED concrete ,BLAST effect ,STRUCTURAL failures ,EXPLOSIONS ,CONSTRUCTION slabs ,PRODUCT attributes ,PLASTICS - Abstract
Plastic spacers create a linear and systemic weakening of the structure. The extreme loading of the structure tests the structure itself to its load-bearing limit or even locally exceeds this limit, thus revealing all its weak points, which are the spacers. Nevertheless, the influence of the spacers is not included in the design calculation of the reinforced concrete element. In addition, products intended as spacers for the placement of reinforcement do not belong to the specific families of construction products covered by a harmonized standard of European parliament regulation. For these reasons, it is not required to demonstrate any characteristics of these products. This fact allows the use of arbitrary spacers' shapes and materials. As shown by the experiment carried out, the use of commonly used plastic liners will result in a weakening of the cross-section. The normal assessment of the ultimate or serviceability limit state is not affected by this weakening. An example of an experiment carried out where this problem was captured is the subject of this paper. With Europe's current deteriorated safety situation, understanding the influence of spacers in blast-loaded reinforced concrete structures on structural failure is important, and it is appropriate to further address this issue. Based on this experiment, it is not possible to accurately identify the causes of the explosion cracks. In order to determine with certainty the effect of spacers on the strength of the structure under abnormal blast loadings, research needs to focus on this area. In the field experimental measurements and numerical simulations, it was found that the use of linear spacers has an effect on crack formation under the blast action of the tested slab. [ABSTRACT FROM AUTHOR]
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- 2023
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56. Breast Reconstruction Using a Prepectoral Spacer
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Becker, Hilton, Vidya, Raghavan, editor, and Becker, Hilton, editor
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- 2023
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57. Spacers for 3D Textiles as Reinforcement in Cement Composites: Influence on the Flexural and Cracking Behavior
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El Kadi, M., Gielis, C., Toma, D., Van Hemelrijck, D., Rahier, H., Tysmans, T., Kunieda, Minoru, editor, Kanakubo, Toshiyuki, editor, Kanda, Tetsushi, editor, and Kobayashi, Koichi, editor
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- 2023
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58. CRISPR-Cas systems feature and targeting phages diversity in Lacticaseibacillus rhamnosus strains
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Bahman Panahi, Behnaz Dehganzad, and Yousef Nami
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CRISPR ,genome ,immune system ,phage ,spacer ,Microbiology ,QR1-502 - Abstract
One of the most important adaptive immune systems in bacteria against phages is clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (CAS) genes. In this investigation, an approach based on genome mining was employed to characterize the CRISPR-Cas systems of Lacticaseibacillus rhamnosus strains. The analysis involved retrieving complete genome sequences of L. rhamnosus strains, and assessing the diversity, prevalence, and evolution of their CRISPR-Cas systems. Following this, an analysis of homology in spacer sequences from identified CRISPR arrays was carried out to investigate and characterize the range of target phages. The findings revealed that 106 strains possessed valid CRISPR-Cas structures (comprising CRISPR loci and Cas genes), constituting 45% of the examined L. rhamnosus strains. The diversity observed in the CRISPR-Cas systems indicated that all identified systems belonged to subtype II-A. Analyzing the homology of spacer sequences with phage and prophage genomes discovered that strains possessing only CRISPR-Cas subtype II targeted a broader spectrum of foreign phages. In summary, this study suggests that while there is not significant diversity among the CRISPR-Cas systems identified in L. rhamnosus strains, there exists notable variation in subtype II-A systems between L. rhamnosus and other lactobacilli. The diverse nature of these CRISPR-Cas systems underscores their natural activity and importance in adaptive immunity.
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- 2023
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59. Enhanced antibiotic release from bone cement spacers utilizing dual antibiotic loading with elevated vancomycin concentrations in two-stage revision for periprosthetic joint infection.
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Lunz, Andre, Schonhoff, Mareike, Omlor, Georg W., Knappe, Kevin, Bangert, Yannic, Lehner, Burkhard, Renkawitz, Tobias, and Jaeger, Sebastian
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JOINT infections , *BONE cements , *ANTIBIOTICS , *VANCOMYCIN , *GENTAMICIN - Abstract
Purpose: Antibiotic loaded bone cement spacers provide high local antibiotic concentrations, preserve bone stock, and reduce soft tissue contractions. The objective of this in-vitro study was to compare antibiotic release from spacers, aiming to discover the most optimal preparation and identify modifiable factors that can further enhance antibiotic release. Methods: Six distinct spacer preparation were created using three different bone cements and manual incorporation of antibiotics. During a six-week period, the release of antibiotics from each spacer was measured individually at ten predetermined time points using a chemiluminescent immunoassay. Results: Manually adding 4 g of vancomycin to every 40 g of "Palacos R + G" yielded the most favorable release profile. Throughout all preparations, antibiotic release consistently and significantly decreased over the six-week period. When incorporating a higher concentration of vancomycin, a significantly higher cumulative release of vancomycin was observed, with varying effects on the release of gentamicin. The choice of bone cement had a significant impact on antibiotic release. Conclusion: To enhance antibiotic release from spacers, surgeons should manually incorporate high antibiotic concentrations into the most appropriate bone cement and keep the interim period as short as possible. Specifically, we suggest manual incorporation of 4 g of vancomycin to every 40 g of gentamicin premixed "Palacos R + G" to create bone cement spacers. [ABSTRACT FROM AUTHOR]
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- 2023
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60. The Practice Patterns of American Association of Hip and Knee Surgeons for the Management of Chronic Periprosthetic Joint Infection After Total Knee Arthroplasty.
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Duncan, Stephen T., Schwarzkopf, Ran, Seyler, Thorsten M., and Landy, David C.
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The management of periprosthetic joint infection (PJI) following total knee arthroplasty (TKA) has considerable variation. In order to better capture current preferences for the management of PJI, this study sought to poll the current members of American Association of Hip and Knee Surgeons (AAHKS) first to characterize the distribution of practice patterns. There were 32 questions in an online survey distributed to members of AAHKS. The questions were multiple choice regarding the management of PJI for TKA. There were 844 out of 2,752 members who completed the survey (response rate of 31%). Most of the members were in private practice (50%) compared to 28% being in an academic setting. On average, members were performing between 6 to 20 PJI cases per year. Two-stage exchange arthroplasty was performed in over 75% of the cases with either a cruciate retaining (CR) or posterior stabilized (PS) primary femoral component used in over 50% of the cases and 62% using an all-polyethylene tibial implant. Most of the members were using vancomycin and tobramycin. Typically, 2 to 3 grams of antibiotics were added per bag of cement regardless of the cement type. When indicated, amphotericin was the most often-used antifungal. Post-operative management had major variability with range of motion, brace use, and weight-bearing restrictions. There was variability in the responses from the members of AAHKS, but there was a preference toward performing a two-stage exchange arthroplasty with an articulating spacer using a metal femoral component and an all-polyethylene liner. [ABSTRACT FROM AUTHOR]
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- 2023
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61. Comparative analysis of ferroelectric quad-FinFET with and without Si3N4 spacer on analog/RF, linearity performance and digital inverter application with temperature variation.
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Vanlalawmpuia, K. and Medury, Aditya Sankar
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COMPARATIVE studies , *LOW temperatures , *TEMPERATURE - Abstract
The article presents a comparative study on the performance of a ferroelectric quad-FinFET (Fe-QFinFET) with and without the implementation of Si3N4 spacer for different temperature variations by integrating the temperature-dependent Landau-coefficients into the 3D TCAD simulator. The drain current enhances in the subthreshold region while it decreases in the superthreshold region as the temperature is increased. The analog/RF parameters are enhanced at lower temperatures with the spacer dielectric. However, the Fe-QFinFET with spacer have incurred an expense in the form of a substantially high gate capacitance. A digital inverter is used to analyse the circuit performance of the Fe-QFinFET. [ABSTRACT FROM AUTHOR]
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- 2023
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62. Comparison of Structural Features of CRISPR-Cas Systems in Thermophilic Bacteria.
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Wang, Chuan, Yang, Yuze, Tang, Shaoqing, Liu, Yuanzi, Wei, Yaqin, Wan, Xuerui, Liu, Yajuan, Zhang, Zhao, and Sunkang, Yongjie
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CRISPRS ,THERMOPHILIC bacteria ,BACTERIAL adaptation ,WHOLE genome sequencing - Abstract
The clustered regularly interspaced short palindromic repeat (CRISPR) is an adaptive immune system that defends most archaea and many bacteria from foreign DNA, such as phages, viruses, and plasmids. The link between the CRISPR-Cas system and the optimum growth temperature of thermophilic bacteria remains unclear. To investigate the relationship between the structural characteristics, diversity, and distribution properties of the CRISPR-Cas system and the optimum growth temperature in thermophilic bacteria, genomes of 61 species of thermophilic bacteria with complete genome sequences were downloaded from GenBank in this study. We used CRISPRFinder to extensively study CRISPR structures and CRISPR-associated genes (cas) from thermophilic bacteria. We statistically analyzed the association between the CRISPR-Cas system and the optimum growth temperature of thermophilic bacteria. The results revealed that 59 strains of 61 thermophilic bacteria had at least one CRISPR locus, accounting for 96.72% of the total. Additionally, a total of 362 CRISPR loci, 209 entirely distinct repetitive sequences, 131 cas genes, and 7744 spacer sequences were discovered. The average number of CRISPR loci and the average minimum free energy (MFE) of the RNA secondary structure of repeat sequences were positively correlated with temperature whereas the average length of CRISPR loci and the average number of spacers were negatively correlated. The temperature did not affect the average number of CRISPR loci, the average length of repeats, or the guanine-cytosine (GC) content of repeats. The average number of CRISPR loci, the average length of the repeats, and the GC content of the repeats did not reflect temperature dependence. This study may provide a new basis for the study of the thermophilic bacterial adaptation mechanisms of thermophilic bacteria. [ABSTRACT FROM AUTHOR]
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- 2023
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63. Finite element analysis of the mechanical strength of a new hip Spacer
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Hao Ge, Hongsong Yan, Xianwang Liu, Yiwei Huang, and Jianchun Zeng
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Finite element ,Periprosthetic joint infection ,Bone cement ,Spacer ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background and objective At present, the influence of the internal metallic endoskeleton of Spacer on the biomechanical strength of Spacer remains unclear. The aim of this study was to analyze the mechanical stability of a novel Spacer applying a annular skeleton that mimics the structure of trabecular bone using finite element methods. Metheds The femur models of three healthy individuals and skeletonless Spacer, K-Spacer, and AD-Spacer were assembled to create 15 3D models. Finite element analysis was performed in an Ansys Bench2022R1. Biomechanical parameters such as stress and strain of the Spacer, internal skeleton and femur were evaluated under three loads, which were applied with the maximum force borne by the hip joint (2100 N), standing on one leg (700 N), and standing on two legs (350 N). The mechanical properties of the new hip Spacer were evaluated. Result The stresses on the medial and lateral surfaces of the AD-Spacer and K-Spacer were smaller than the stresses in the state without skeletal support. The maximum stresses on the medial and lateral surfaces of the AD-Spacer were smaller than those of the inserted K-Spacer, and the difference gradually increased with the increase of force intensity. When the skeleton diameter was increased from 3 to 4 mm, the stresses in the medial and lateral sides of the AD-Spacer and K-Spacer necks decreased. The stress of both skeletons was concentrated at the neck, but the stress of the annular skeleton was evenly distributed on the medial and lateral sides of the skeleton. The mean stress in the proximal femur was higher in femurs with K-Spacer than in femurs with AD-Spacer. Conclusions AD-Spacer has lower stress and higher load-bearing capacity than K-Spacer, and the advantages of AD-Spacer are more obvious under the maximum load state of hip joint.
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- 2023
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64. Persistent Chronic Periprosthetic Joint Infection Treated with Three-Stage Revision Hip Arthroplasty: A Case Report
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Nurul Ramadian and Jifaldi Afrian Maharaja Dinda Sedar
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total hip arthroplasty ,periprosthetic joint infection ,spacer ,debridement ,human and medicine ,Medicine - Abstract
Background: Periprosthetic Joint Infection (PJI) is a dreadful complication of primary Total Hip Arthroplasty (THA). Following revision THA, up to 17% of revision THA can be complicated with PJI. Three-stage revision should only be done if simple debridement fails to treat PJI. Here we present a rare case of persistent PJI, treated with three-stage revision and bone grafting. Case Report: A thirty-seven-year-old female patient came with a chief complaint of hip pain four months ago. Four years ago, the patient had a right column femur fracture and was treated with THA. One year afterward, the implant was infected, and the hip was debrided. One year later, the infection symptom recurred, and three-stage revision hip arthroplasty was planned with one year delay for each stage: removal of the implant, replacement of spacer, and reimplantation. The acetabular bone was augmented using autograft from the iliac wing during reimplantation. After reimplantation, the pain subsides, and the patient can walk normally again. Discussion: Previous studies have found various risk factors that might contribute to the failure of two-stage revision arthroplasty. The infecting bacteria is one of the major risk factors, and therefore appropriate antibiotic is important. Augmentation of bone graft can also supplement acetabular bone loss during failed THA as it helps as a scaffold for bone healing. Conclusion: Three-stage revision hip arthroplasty after PJI using bone graft for augmentation is possible with a good result.
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- 2023
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65. Rationale for choosing a spacer at the first treatment stage for late deep periprosthetic knee joint infection
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Stanislav A. Linnik, Anna G. Afinogenova, Gennady E. Afinogenov, Anna A. Spiridonova, Yaroslav B. Tsololo, Giorgi Karagezov, Valerii M. Khaidarov, Dmitry V. Kravtsov, Ivan O. Kucheev, Aleksandr A. Khromov, Ismael Abbas, and Maksim V. Maryshev
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knee joint ,two-stage revision arthroplasty ,periprosthetic infection ,antimicrobial composition ,spacer ,Orthopedic surgery ,RD701-811 - Abstract
Background Periprosthetic infection develops in 0.5 to 5.0 % of cases after knee replacement, which is a social and economic problem. The most common causes of periprosthetic infection are methicillin-resistant staphylococcus aureus (MRSA) (36 %), gram-negative bacteria, and microbial associations. The study was aimed at improving the results of the sanitizing stage of revision arthroplasty in patients with periprosthetic infection of the knee joint by a developed long-acting antimicrobial composition and improving the designs of articulating spacers of the knee joint. Materials and Methods The treatment results of 121 patients with knee joint periprosthetic infection were analyzed. Nine patients had an early periprosthetic infection and 112 had a late one. Patients in satisfactory condition with stable implant components who had early periprosthetic infection underwent surgical treatment of the purulent focuses, replacement of a polyethylene tibial insert, thorough surgical wound washing using pulse lavage, drainage, and VAC-therapy. Patients with late periprosthetic infection were divided into 3 groups on the basis of the spacer used. An articulating spacer based on the developed antimicrobial composition of prolonged action (RU 191236 patent) was used in 59 patients of the first group. Preformed spacers were implanted in 29 patients of the second group, and 18 patients of the third group got a block-shaped spacer. Results An antibacterial anti-adhesive non-toxic composition with a prolonged action based on bone cement with gentamicin and such antiseptics as poviargol, dioxydine, and high-molecular polyvinylpyrrolidone has been developed. All the patients underwent the sanitizing stage of revision arthroplasty, implant removal, and spacer installation. Periprosthetic infection recurrence developed in 3 patients of the first group, 9 patients of the second group and 7 patients of the third one. The average time from the sanitizing stage to the second final stage of revision was 3-6 (4.8 ± 1.9) months. Discussion According to scientific data, the impregnation of new antibiotics into bone cement with gentamicin does not improve the antimicrobial effect of a spacer, especially in case of antibiotic-resistant strains. Block-shaped and preformed spacers lead to infection recurrence and complications. Antiseptic impregnation with different mechanisms of action is able to affect antibiotic-resistant bacteria, and the polymer is able to prolong the effect. Conclusion The use of articulating spacers for the knee joint, which include an antimicrobial composition, allows preserving the function of the joint and reducing the number of infectious complications, which facilitates the final stage of revision arthroplasty.
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- 2023
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66. Ohmic charging in capacitive deionization: Efficient water desalination using capacitive spacers
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Johan Nordstrand and Joydeep Dutta
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capacitive deionization ,desalination ,modeling ,simulation ,spacer ,Materials of engineering and construction. Mechanics of materials ,TA401-492 - Abstract
Abstract Capacitive deionization (CDI) is a promising desalination technology based on electrosorption on the surfaces of microporous electrodes. However, low total dissolved solids (TDS) in the water restricts its efficacy. In this work, we develop the theory of capacitive spacers (CS) in CDI. The investigations reveal a mechanism that we call ohmic charging; that is, the resistive losses in the spacer region drive adsorption in the CS. As a consequence, the obtained results show that such spacers can improve desalination efficiency, especially at ion‐starved conditions. The spacers also enhance the charging rate of the electrodes because the overall resistance is lower when the current can pass the spacer material instead of the solution, through the adsorption of anions on one side and cations on the other. Going deeper, the investigations reveal a major challenge; the spacer naturally discharges on the same timescale as the electrode charging timescale. However, only the fast timescale matters with low ionic content solutions, and under these conditions the CS are found to be superior. Put together, CS can make a significant difference, especially when the ion concentration is low or the cycle times are short.
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- 2023
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67. A case of treatment of a fungal periprosthetic infection with a carbon-coated implant
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L. I. Malyuchenko, N. S. Nikolaev, L. V. Lyubimova, E. V. Preobrazhenskaya, and D. N. Efimov
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periprosthetic infection ,candida albicans ,two-stage revision ,spacer ,carbon coating ,silver plating ,Medicine (General) ,R5-920 - Abstract
Background. Arthroplasty is the most common surgical treatment for patients with end-stage knee arthrosis. From 2 to 7% of those operated on are patients with rheumatoid arthritis. The inflammatory process in the joint, low rehabilitation potential, long-term therapy with hormonal and genetically engineered biological agents, poor bone quality form a high risk of periprosthetic infection. In this group of patients, the saprophytic microorganism Candida albicans more often forms biofilms on endoprosthesis components, which presents difficulties in the treatment of periprosthetic infection.Aims: demonstration of a clinical case and rationale for the treatment of periprosthetic knee infection caused by Candida albicans using a revision implant with an anti-biofilm coating.Materials and methods. A clinical case presents the results of examination and treatment of a 46-year-old patient with secondary gonarthrosis on the background of rheumatoid arthritis with developed periprosthetic infection are evaluated. Surgical treatment was carried out by two-stage sanitation, using as part of the spacer an implant coated with silver-doped two-dimensionally ordered linear-chain carbon, against the background of etiotropic intravenous treatment with fluconazole.Results. The likely cause of the development of a fungal periprosthetic infection is a decrease in the activity of the immune system against the background of taking cytostatics and hormonal drugs in combination with the frequent uncontrolled use of antibacterial drugs. The choice of surgical tactics in favor of a two-stage revision is justified by the isolation of a «difficult to treat» Candida albicans. Timely diagnosis and the chosen method of treatment in combination allowed to no recurrence during the observation period of 12 months after the 2nd stage of revision.Conclusions. The results demonstrate the effectiveness of a spacer coated with silver-doped two-dimensionally ordered linear-chain carbon at the stage of sanitation for the treatment of periprosthetic infection caused by the «difficult to treat» Candida albicans.
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- 2023
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68. Clinical evaluation of a new technique for custom-made spacers in septic two-stage revision of total hip arthroplasties.
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Mederake, Moritz, Hofmann, Ulf Krister, and Fink, Bernd
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REOPERATION , *JOINT infections , *REIMPLANTATION (Surgery) , *TOTAL hip replacement , *REINFECTION , *COMPARATIVE studies - Abstract
Introduction: In septic two-stage revision surgery, success depends on numerous factors. Key steps are the procedure of ex- and reimplantation and the choice of spacer in the interim phase. The latter is still a matter of debate. Recently, we showed the microbial non-inferiority of a spacer technique using prosthetic cemented implants with an individualized antibiotic mixture in the cement applying a mechanically inferior cementation method. The aim of the present study was to evaluate the clinical results of these spacers in view of either an endofemoral or a transfemoral procedure. Materials and methods: Our collective consisted of 86 patients (45 endofemoral and 41 transfemoral procedures). The collective was analyzed with respect to complications, reinfection rate and clinical status at the end of the interim phase. Results of an endofemoral and transfemoral approach were compared. Results: With a median Staffelstein-Score of 60 (range 31–81) at the end of the interim phase, the first clinical results are promising. The reinfection-free rate after a median follow-up of 50 months was 90%. Spacer-related complications occurred in 8% of the total collective. Comparing the endo- and transfemoral procedure, there were no statistical differences in complications or regarding the clinical and infectiological outcome. Conclusions: In this study, we were able to show good clinical results for the presented spacer technique. With no relevant difference in outcome, the decision for an endofemoral or transfemoral technique can be based on technical deliberations. Further prospective comparative studies are necessary to show the clinical benefit of this procedure. [ABSTRACT FROM AUTHOR]
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- 2023
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69. Self-Aggregation, Antimicrobial Activity and Cytotoxicity of Ester-Bonded Gemini Quaternary Ammonium Salts: The Role of the Spacer.
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Liang, Yaqin, Li, Hui, Ji, Jiahui, Wang, Jiayu, and Ji, Yujie
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QUATERNARY ammonium salts , *ANTI-infective agents , *ESCHERICHIA coli , *SURFACE tension , *HELA cells , *AMMONIUM salts - Abstract
Five ester-bonded gemini quaternary ammonium surfactants C12-En-C12 (n = 2, 4, 6), with a flexible spacer group, and C12-Bm-C12 (m = 1, 2), with rigid benzene spacers, were synthesized via a two-step reaction and analyzed. Furthermore, the effects of the spacer structure, spacer length and polymerization degree on the self-aggregation, antimicrobial activity and cytotoxicity of C12-En-C12 and C12-Bm-C12 and their corresponding monomer N-dodecyl-N,N,N-trimethyl ammonium chloride DTAC were investigated. The results showed that C12-En-C12 and C12-Bm-C12 had markedly lower critical micellar concentration (CMC) values and lower surface tension than DTAC. Moreover, the CMC values of C12-En-C12 and C12-Bm-C12 decreased with increasing spacer length. In the case of equivalent chain length, the rigidity and steric hindrance of phenylene and 1,4-benzenediyl resulted in larger CMC values for C12-Bm-C12 than for C12-En-C12. The antibacterial ability of C12-En-C12 and C12-Bm-C12 was assessed using Escherichia coli (E. coli) and Staphylococcus albus (S. aureus) based on minimum inhibitory concentrations (MICs). Furthermore, C12-En-C12 and C12-Bm-C12 exhibited higher antimicrobial activity than DTAC and had stronger function toward S. aureus than E. coli. The antimicrobial activity was enhanced by increasing the spacer chain length and decreased with the increased rigidity of the spacers. The cytotoxic effects of C12-En-C12 and C12-Bm-C12 in cultured Hela cells were evaluated by the standard CCK8 method based on half-maximal inhibitory concentration (IC50). The cytotoxicity of C12-En-C12 and C12-Bm-C12 was significantly lower than alkanediyl-α,ω-bis(dimethyldodecylammonium) bromide surfactants and DTAC. The spacer structure and the spacer length could induce significant cytotoxic effects on Hela cells. These findings indicate that the five ester-bonded GQASs have stronger antibacterial activity and lower toxicity profile, and thus can be used in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]
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- 2023
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70. 纳米乳液型冲洗隔离液体系构建及性能评价.
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孟仁洲, 牟少敏, 李渊, 王成文, 于永金, and 齐奉忠
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DRILLING fluids , *DRILLING muds , *CEMENT slurry , *INTERFACIAL tension , *DYNAMIC stability , *SLURRY , *POLYMERS - Abstract
Oil based drilling fluids have been widely used in drilling unconventional wells, and one of the key problems with the use of oil based drilling fluids is how to effectively clean off the residue mud and the mud cakes on the borehole wall to provide a good bonding surface for cement slurries. Nanometer emulsion has low surface tension, small droplets and strong solubilization capacity, making it a good flushing fluid for cleaning residue oil based drilling fluids. Take the flushing efficiency and the sizes of the emulsion droplets as the evaluation criteria, a nanometer emulsion was selected as a flushing fluid for residue oil based mud cleaning. By testing the stability, electric potential and sizes of the droplets, the compatibility of the emulsion and spacer additives was analyzed, and a nanometer emulsion flushing spacer was formulated as a result of the study. Laboratory studies show that by changing the ratio of two surfactants, which are alkyl glycoside and polyoxyethylene ether, from 2∶8 to 9∶1, the flushing efficiency of the nanometer emulsion first increased and then decreased, the sizes of the droplets first decreased and then increased. The consistency between the flushing efficiency and small droplet size of the nanometer emulsion provides a theoretical basis for selecting an emulsion with both high flushing efficiency and dynamic stability. Some polymer additives will increase the viscosity of the nanometer emulsion and the oil-water interfacial tension, but do not significantly affect the stability of the nanometer emulsion. Surfactants with opposite charges will decrease the Zeta potential of a nanometer emulsion droplet, leading to a decrease of the stability of the nanometer emulsion. Commonly additives can be directly used to control of properties of a nanometer emulsion and to make nanometer emulsion flushing spacers. The spacer formulated in this study has stable rheology, high settling stability and good compatibility with cement slurries at temperatures up to 100 ℃. At 120 ℃, the spacer has flushing efficiency in 3 min of more than 99% and is able to remarkably enhance the bonding strength of the cement sheaths on the walls of the borehole drilled with an oil based drilling fluid. [ABSTRACT FROM AUTHOR]
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- 2023
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71. The impact of the spacer and metal layer on the absorption of the heterostructures composed of TMDCs to design narrowband and broadband absorbers.
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Ansari, Narges, Mohebbi, Ensyieh, and Rezaei, Narges
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HETEROSTRUCTURES , *OPTICAL polarization , *OPTICAL devices , *ABSORPTION , *LIGHT absorption , *COPPER-zinc alloys - Abstract
Owing to their exceptional optical and electronic properties, the two-dimensional transition metal dichalcogenide (TMDC) monolayers have received a great deal of attention. In fact, it has been suggested that heterostructures including spacers, metals, and two of the TMDC monolayers increase absorption of the narrowband and broadband in the visible range. This study investigates the effects of the number, place, and thickness of the spacers; metal thickness; and angle and polarization of the incident light on the absorption. Inserting the spacer into the structure increases the absorption via inducing light localization and enhancing the intensity of the light in the TMDC monolayers. Further, the effect of employing one spacer on improving the absorption is almost equal to making use of double spacers. The proposed structures by enhanced light-material interaction can raise the amount of the absorption over 90% throughout the broadband wavelength range of 300–480 nm and above 65% at the narrowband wavelength of 617 nm. The findings of the study suggest promising prospects of these structures for a variety of applications particularly in narrowband and broadband optical devices. [ABSTRACT FROM AUTHOR]
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- 2023
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72. Staged Management of Infection with Adjustable Spacers After Megaprosthesis Implantation in Primary Sarcoma Patients.
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Şirin, Evrim, Sofulu, Ömer, Baysal, Özgür, Akgülle, Ahmet Hamdi, and Erol, Bülent
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MUSCULOSKELETAL system diseases , *PROSTHETICS , *DEBRIDEMENT , *BONE cements , *OSTEOSARCOMA , *CONNECTIVE tissues , *SURGICAL complications , *PLASTIC surgery , *SURGERY , *PATIENTS , *INFECTION , *TREATMENT effectiveness , *CANCER patients , *REOPERATION , *DEATH , *LEG amputation , *ORTHOPEDIC apparatus , *ANTIBIOTICS , *EVALUATION - Abstract
Background: While periprosthetic joint infection has always been a significant concern for orthopaedic surgeons, the rate of infection is five to ten times higher after tumor prosthesis implantation. With the growing use of mega-implants, the number of these infections has also increased. We aimed to investigate the results of our patients with a primary malignant musculoskeletal tumor, who underwent two-stage revision surgery for an infected mega-prosthesis. We also presented the emerging complicatons and required soft tissue reconstruction procedures. Methods: The study included 32 primary bone and soft tissue sarcoma patients who underwent a two-stage revision procedure for infection. After a rigorous bone and soft tissue debridement procedure at the first stage, antibiotic-loaded bone cement was wrapped around a cloverleaf type intramedullary nail and inserted into the forming gap. After a minimum of 6 weeks of antibiotic therapy, depending on patients' clinical signs and serum infection markers, the reimplantation stage was undertaken. Results: The mean oncologic follow-up period was 28 months (range 5–96 months). During this period, 11 patients died because of non-infection related causes, 12 patients were alive with their disease, whereas 9 patients were totally free of their oncologic condition. The infection was eradicated in all survivors except one patient, where a high-level transfemoral amputation became necessary. Conclusion: Periprosthetic infection after tumor proshesis implantation in cancer patients can be managed with same principles as conventional arthroplaty procedures, taking care that they are immunocompromised and vulnerable patients and their bone stock loss is significant which makes surgical options more challenging. [ABSTRACT FROM AUTHOR]
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- 2023
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73. Analysis of CRISPR/Cas Genetic Structure, Spacer Content and Molecular Epidemiology in Brazilian Acinetobacter baumannii Clinical Isolates.
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Silva, Adrianne M. A., Luz, Ana C. O., Xavier, Keyla V. M., Barros, Maria P. S., Alves, Hirisleide B., Batista, Marcus V. A., and Leal-Balbino, Tereza C.
- Subjects
ACINETOBACTER baumannii ,MOLECULAR epidemiology ,CRISPRS ,MOBILE genetic elements ,BACTERIAL evolution ,ROOT rots ,NOSOCOMIAL infections ,PLANT viruses - Abstract
CRISPR/Cas is a molecular mechanism to prevent predatory viruses from invading bacteria via the insertion of small viral sequences (spacers) in its repetitive locus. The nature of spacer incorporation and the viral origins of spacers provide an overview of the genetic evolution of bacteria, their natural viral predators, and the mechanisms that prokaryotes may use to protect themselves, or to acquire mobile genetic elements such as plasmids. Here, we report on the CRISPR/Cas genetic structure, its spacer content, and strain epidemiology through MLST and CRISPR typing in Acinetobacter baumannii, an opportunistic pathogen intimately related to hospital infections and antimicrobial resistance. Results show distinct genetic characteristics, such as polymorphisms specific to ancestor direct repeats, a well-defined degenerate repeat, and a conserved leader sequence, as well as showing most spacers as targeting bacteriophages, and several self-targeting spacers, directed at prophages. There was a particular relationship between CRISPR/Cas and CC113 in the study of Brazilian isolates, and CRISPR-related typing techniques are interesting for subtyping strains with the same MLST profile. We want to emphasize the significance of descriptive genetic research on CRISPR loci, and we argue that spacer or CRISPR typing are helpful for small-scale investigations, preferably in conjunction with other molecular typing techniques such as MLST. [ABSTRACT FROM AUTHOR]
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- 2023
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74. MucoUp® as a spacer in brachytherapy for uterine cervical cancer: A first-in-human experience
- Author
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Yoichi Muramoto, Naoya Murakami, Tatsuki Karino, Satoru Sugimoto, Jun Takatsu, Masaki Oshima, Yasuo Kosugi, Terufumi Kawamoto, Takashi Hirayama, Kazunari Fujino, Yasuhisa Terao, and Naoto Shikama
- Subjects
Brachytherapy ,Uterine cervical cancer ,Spacer ,MucoUp® ,Medical physics. Medical radiology. Nuclear medicine ,R895-920 ,Neoplasms. Tumors. Oncology. Including cancer and carcinogens ,RC254-282 - Abstract
We first used MucoUp®, a hyaluronic acid used in endoscopic resection, as a spacer in brachytherapy. In five cervical cancer patients, MucoUp® insertion increased a 90% dose of the high-risk CTV to over 80 Gy while decreasing the dose of organs at risk. No related adverse events were observed.
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- 2023
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75. Respiratory Equipment Adaptations in a Low-Resource Setting
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Desai, Brinda, Shah, Zubin, Slusher, Tina M., editor, Bjorklund, Ashley R., editor, and Lauden, Stephanie M., editor
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- 2022
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76. Demonstration of High-Permittivity Sidewall Spacer in Negative Capacitance FinFET
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Chauhan, Vibhuti, Samajdar, Dip Prakash, Bagga, Navjeet, Ghosh, Arindam, Series Editor, Chua, Daniel, Series Editor, de Souza, Flavio Leandro, Series Editor, Aktas, Oral Cenk, Series Editor, Han, Yafang, Series Editor, Gong, Jianghong, Series Editor, Jawaid, Mohammad, Series Editor, Mukherjee, Kalisadhan, editor, Layek, Rama Kanta, editor, and De, Debasis, editor
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- 2022
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77. Force Simulation of Four Bundle Spacer Under Short Circuit Condition
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Lei, Wang, Jianli, Zhao, Liang, Wang, Zijian, Zhao, Angrisani, Leopoldo, Series Editor, Arteaga, Marco, Series Editor, Panigrahi, Bijaya Ketan, Series Editor, Chakraborty, Samarjit, Series Editor, Chen, Jiming, Series Editor, Chen, Shanben, Series Editor, Chen, Tan Kay, Series Editor, Dillmann, Rüdiger, Series Editor, Duan, Haibin, Series Editor, Ferrari, Gianluigi, Series Editor, Ferre, Manuel, Series Editor, Hirche, Sandra, Series Editor, Jabbari, Faryar, Series Editor, Jia, Limin, Series Editor, Kacprzyk, Janusz, Series Editor, Khamis, Alaa, Series Editor, Kroeger, Torsten, Series Editor, Li, Yong, Series Editor, Liang, Qilian, Series Editor, Martín, Ferran, Series Editor, Ming, Tan Cher, Series Editor, Minker, Wolfgang, Series Editor, Misra, Pradeep, Series Editor, Möller, Sebastian, Series Editor, Mukhopadhyay, Subhas, Series Editor, Ning, Cun-Zheng, Series Editor, Nishida, Toyoaki, Series Editor, Oneto, Luca, Series Editor, Pascucci, Federica, Series Editor, Qin, Yong, Series Editor, Seng, Gan Woon, Series Editor, Speidel, Joachim, Series Editor, Veiga, Germano, Series Editor, Wu, Haitao, Series Editor, Zamboni, Walter, Series Editor, Zhang, Junjie James, Series Editor, Yang, Qingxin, editor, Liang, Xidong, editor, Li, Yaohua, editor, and He, Jinghan, editor
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- 2022
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78. Femoral Spacers in Septic Two-Stage Revision
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Fink, Bernd and Fink, Bernd
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- 2022
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79. Mechanical strength of antibiotic-loaded PMMA spacers in two-stage revision surgery
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Andre Lunz, Kevin Knappe, Georg W. Omlor, Mareike Schonhoff, Tobias Renkawitz, and Sebastian Jaeger
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Periprosthetic joint infection ,Two-stage revision ,PMMA bone cement ,dALBC ,Spacer ,Diseases of the musculoskeletal system ,RC925-935 - Abstract
Abstract Background Antibiotic-loaded polymethylmethacrylate (PMMA) bone cement spacers provide high local antibiotic concentrations and patient mobility during the interim period of two-stage revision for periprosthetic joint infection (PJI). This study compares mechanical characteristics of six dual antibiotic-loaded bone cement (dALBC) preparations made from three different PMMA bone cements. The study`s main objective was to determine the effect of time and antibiotic concentration on mechanical strength of dALBCs frequently used for spacer fabrication in the setting of two-stage revision for PJI. Methods A total of 84 dual antibiotic-loaded bone cement specimens made of either Copal spacem, Copal G + V or Palacos R + G were fabricated. Each specimen contained 0.5 g of gentamicin and either 2 g (low concentration) or 4 g (high concentration) of vancomycin powder per 40 g bone cement. The bending strength was determined at two different timepoints, 24 h and six weeks after spacer fabrication, using the four-point bending test. Results Preparations made from Copal G + V showed the highest bending strength after incubation for 24 h with a mean of 57.6 ± 1.2 MPa (low concentration) and 50.4 ± 4.4 MPa (high concentration). After incubation for six weeks the bending strength had decreased in all six preparations and Palacos R + G showed the highest bending strength in the high concentration group (39.4 ± 1.6 MPa). All low concentration preparations showed superior mechanical strength compared to their high concentration (4 g of vancomycin) counterpart. This difference was statistically significant for Copal spacem and Copal G + V (both p
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- 2022
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80. A Mid‐term Follow‐up Study on the Reimplantation of Autoclaved Femoral and Tibial Components as Spacers for Treating Infected Total Knee Arthroplasty
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Peng Li, Zhiqi Zhu, Xiangyang Tang, and Zhanjun Shi
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Arthroplasty ,Component ,Disinfection ,Infection ,Replantation ,Spacer ,Orthopedic surgery ,RD701-811 - Abstract
Objective Infection after total knee arthroplasty (TKA) is a rare but devastating complication. Different types of spaces have been used in two‐stage revision. The study aimed to evaluate the effect of autoclaved femoral and tibial components as spacers for treating periprosthetic infections after TKA. Methods A retrospective study was performed for 13 patients (five males, eight females) with a mean age of 69 ± 6 (range, 57–80) years and suffering from periprosthetic infection after TKA. They were treated with unconventional two‐stage revision from May 2008 to June 2017. In the first‐stage surgery, the autoclaved femoral and tibial components were reimplanted with a new liner as a spacer after a thorough debridement. After 4–6 months, the second‐stage surgery was performed according to the patients' requirements. The knee society score (KSS) and knee range of motion (ROM) were assessed before and after surgery. The reinfection rate was calculated. Results The mean duration of follow‐up was 5.7 ± 2.1 (range, 3.1–8.8) years. Culture‐positive infections comprised 69% of the cohort. All patients were able to walk 24 h after the first stage surgery, and the knee ROM could reach 90° in 1 week. Two patients (15.4%) experienced an infection recurrence. One patient was reinfected 1 year after the first stage surgery. Another patient developed reinfection 3 years after surgery but did not choose re‐revision and died of pneumonia. Only one patient underwent the second stage revision. The remaining 10 patients refused to receive a new prosthesis. At the time of the final follow‐up, six patients had slight pain in the knee while walking, and one patient required crutches to walk. There were no signs of prosthesis dislocation, rupture, deep vein thrombosis, pulmonary embolism, or delayed wound healing. No radiolucent lines or osteolysis were found. The mean KSS improved from 51 ± 10 (range, 35–63) points preoperatively to 79 ± 5 (range, 60–85) points at the final follow‐up. The average ROM before and after the first stage surgery were 62° ± 29° (range, 10°–100°) and 104° ± 9° (range, 90°–120°) (t = 4.659, P
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- 2022
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81. Safety and tolerability of biodegradable balloon spacers in patients undergoing radiotherapy for organ-confined prostate cancer
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Luca Topazio, Federico Narcisi, Fabio Tana, Cosimo Ciotta, Vincenzo Iossa, Pasquale Perna, Francesco Chiaramonti, and Federico Romantini
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Prostate cancer ,Spacer ,Radiotherapy ,Hypo-fractionated radiotherapy ,Diseases of the genitourinary system. Urology ,RC870-923 - Abstract
Introduction: Radiotherapy is a common treatment for prostate cancer, and can be administered in various ways, including 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and hypo-fractionated radiation therapy. During treatment the gastrointestinal tract may be exposed to radiation and the rectal wall may be exposed to high doses of ionizing radiation, which can lead to rectal bleeding, ulcers or fistulas, and an increased risk of rectum cancer. Various strategies to minimize these complications have been developed in the last decade; one of the most promising is to use a rectal balloon to fixate the prostate gland during treatment or to inject biodegradable spacers between the prostate and rectum to reduce the rectal dose of radiation. Aim of our paper is to evaluate the safety and tolerability of spacers implantation. Materials and methods: From January 2021 to June 2022 all patients with a diagnosis of prostate cancer with unfavorable/ intermediate risk - poor prognosis and programmed hypofractionated radiation therapy were enrolled. In all patients biodegradable balloons spacers were placed posteriorly to the prostate to increase the separation between prostate and rectum. The duration of the procedure, observation time, the appearance of early and late complications and their severity (according to Charlson comorbidity index) and tolerability of the device were recorded at the time of positioning and after 10 days. Results: 25 patients were enrolled in our study. Two patients (8%) underwent acute urine retention resolved with catheterization and one patient (4%) developed a mild perineal hematoma that did not require any treatment. As regards late complications 1 patient (4%) developed hyperpyrexia (> 38°C) the day after the procedure requiring continuation of antibiotic regimen. At T1 visit we recorded no medium-high grade complications. As for the tolerability of the device, it was optimal with no perineal discomfort or alterations of bowel function. Conclusions: Biodegradable balloon spacers appears to be safe and well tolerated and its positioning does not present any technical difficulties or risks of major complications.
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- 2023
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82. Finite element analysis of the mechanical strength of a new hip Spacer.
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Ge, Hao, Yan, Hongsong, Liu, Xianwang, Huang, Yiwei, and Zeng, Jianchun
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FINITE element method ,HIP joint ,CANCELLOUS bone ,SKELETON ,JOINT infections - Abstract
Background and objective: At present, the influence of the internal metallic endoskeleton of Spacer on the biomechanical strength of Spacer remains unclear. The aim of this study was to analyze the mechanical stability of a novel Spacer applying a annular skeleton that mimics the structure of trabecular bone using finite element methods. Metheds: The femur models of three healthy individuals and skeletonless Spacer, K-Spacer, and AD-Spacer were assembled to create 15 3D models. Finite element analysis was performed in an Ansys Bench2022R1. Biomechanical parameters such as stress and strain of the Spacer, internal skeleton and femur were evaluated under three loads, which were applied with the maximum force borne by the hip joint (2100 N), standing on one leg (700 N), and standing on two legs (350 N). The mechanical properties of the new hip Spacer were evaluated. Result: The stresses on the medial and lateral surfaces of the AD-Spacer and K-Spacer were smaller than the stresses in the state without skeletal support. The maximum stresses on the medial and lateral surfaces of the AD-Spacer were smaller than those of the inserted K-Spacer, and the difference gradually increased with the increase of force intensity. When the skeleton diameter was increased from 3 to 4 mm, the stresses in the medial and lateral sides of the AD-Spacer and K-Spacer necks decreased. The stress of both skeletons was concentrated at the neck, but the stress of the annular skeleton was evenly distributed on the medial and lateral sides of the skeleton. The mean stress in the proximal femur was higher in femurs with K-Spacer than in femurs with AD-Spacer. Conclusions: AD-Spacer has lower stress and higher load-bearing capacity than K-Spacer, and the advantages of AD-Spacer are more obvious under the maximum load state of hip joint. [ABSTRACT FROM AUTHOR]
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- 2023
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83. Mechanical complications of hip spacers: a systematic review of the literature.
- Author
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Sambri, Andrea, Fiore, Michele, Rondinella, Claudia, Morante, Lorenzo, Paolucci, Azzurra, Giannini, Claudio, Alfonso, Calogero, and De Paolis, Massimiliano
- Subjects
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JOINT infections , *ARTIFICIAL joints , *FEMORAL fractures , *HIP joint , *MECHANICAL failures ,ACETABULUM surgery - Abstract
Introduction: Temporary spacers used in the staged revision of a hip prosthetic joint infection (PJI) have been associated with several mechanical complications with very variable reported general complications rates up to 73%. The aim of this systematic review was to assess the mechanical complications associated with hip antibiotic-loaded spacers when treating periprosthetic hip PJI. Methods: Through an electronic systematic search of PubMed, articles reporting mechanical complications of spacers used in the treatment of hip PJI were reviewed. Dislocations, spacer fracture, femoral fractures, and acetabular lysis rates were evaluated. Results: Forty studies were included. Standardized molded spacers had a significantly higher weighted mean of total mechanical complication rates (37.2%) when compared to standardized preformed spacers (13.8%, p = 0.039), while no significant difference was found between molded spacers and manually shaped spacers. Spacer dislocation was the most frequent complication. No significant difference in mechanical complication rate was found between spacers with and without any metallic component. Conclusions: Spacer placement in chronic PJI of the hip with bone and soft-tissue defects is challenging and bears a high risk of mechanical failures and progressive bone loss during the interim period. A careful patient selection for spacer implantation is mandatory. [ABSTRACT FROM AUTHOR]
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- 2023
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84. Assessing Inhaler Techniques of Asthma Patients Using Aerosol Inhalation Monitors (AIM): A Cross-Sectional Study.
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Alotaibi, Mansour M., Hughes, Louise, and Ford, William R.
- Subjects
SPIROMETRY equipment ,ASTHMA ,CONFIDENCE intervals ,CROSS-sectional method ,DRUGSTORES ,NEBULIZERS & vaporizers ,DESCRIPTIVE statistics ,RESEARCH funding ,DISEASE prevalence ,CHI-squared test ,INHALATION administration ,SOCIODEMOGRAPHIC factors ,DATA analysis software ,ODDS ratio - Abstract
A high percentage of asthma patients have symptoms that are not well controlled, despite effective drugs being available. One potential reason for this may be that poor inhaler technique limits the dose delivered to the lungs, thereby reducing the therapeutic efficacy. The aim of this study was to assess the prevalence of poor inhaler technique in an asthma patient population and to probe the impact of various demographic parameters on technique quality. This study was conducted at community pharmacies across Wales, UK. Patients diagnosed with asthma and 12 years or older were invited to participate. An aerosol inhalation monitor (AIM, Vitalograph
® ) was used to measure the quality of patient inhaler technique. A total of 295 AIM assessments were carried out. There were significant differences in the quality of inhaler technique across the different inhaler types (p < 0.001, Chi squared). The best technique was associated with dry-powder inhalers (DPI devices, 58% of 72 having good technique), compared with pressurized metered-dose inhalers (pMDI) or pMDIs with a spacer device (18% of 174 and 47% of 49 AIM assessments, respectively). There were some significant associations between gender, age, and quality of inhaler technique, as determined with adjusted odds ratios. It seems that the majority of asthmatic patients were not using their inhalers appropriately. We recommend that healthcare professionals place more emphasis on assessing and correcting inhaler technique, as poor inhaler technique might be responsible for the observed lack of symptom control in the asthma patient population. [ABSTRACT FROM AUTHOR]- Published
- 2023
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85. Two-stage revision for treatment of tuberculous prosthetic hip infection: an outcome analysis.
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Van Le, Tuan, Duong, Tran Binh, Hien, Kha Quang, Ton, Quyen Nguyen Quang, Huyn, Tan, Binh, Tran Phuoc, Tu, Dao Thanh, Tho, Pham Phuoc, Binh, Le Nguyen, Hau, Huynh Phuoc, and Hung, Truong Nguyen Khanh
- Subjects
- *
TUBERCULOSIS diagnosis , *TOTAL hip replacement , *DEBRIDEMENT , *BONE cements , *TIME , *RETROSPECTIVE studies , *SURGERY , *PATIENTS , *ACQUISITION of data , *TREATMENT duration , *VANCOMYCIN , *INFECTION , *TREATMENT effectiveness , *STREPTOMYCIN , *STAPHYLOCOCCAL diseases , *REOPERATION , *TUBERCULOSIS , *MEDICAL records , *ANTITUBERCULAR agents , *DESCRIPTIVE statistics , *MIXED infections , *STAPHYLOCOCCUS , *POLYMERASE chain reaction , *PROSTHESIS-related infections , *ANTIBIOTICS , *ARTHROCENTESIS , *EVALUATION - Abstract
Objectives: Prosthetic joint infections (PJI) and especially tuberculosis (TB) PJI are rare diseases and hard to cure. The effectiveness of treatments for tuberculous PJI still remains a problem. The objective of this research was to indicate the success of two-stage revision replacement and also giving the associated criteria. Methods: From 2015 to 2020, five patients with tuberculous PJI were treated with two-stage revision at Cho Ray hospital, Vietnam. We collected the dataset which included demographic data, the interval from the time of joint replacement to reported infection, records of tuberculous PJI, administration of anti-TB medications (duration, months), history of operation(s), duration of follow-up, and specific type(s) of antibiotics loaded in bone cement. The approval for this study was made by the institutional review board from Cho Ray Hospital, Vietnam. We conducted a literature review based on the keywords "PJI" and "TB" on PubMed. Results: Five patients [median age 66 years (range 35–84)] had found tuberculous PJI. The median time from arthroplasty to diagnosis was 19 months (range 4–48). The diagnosis was confirmed by joint aspirates or synovial tissue. Positive PCR was also reported in all cases. The average duration of anti-tuberculosis polytherapy administration was 14.4 months. The operative techniques on five patients included debridement and using spacer loaded with 2 g streptomycin (and 2 g vancomycin if they got a coinfection) for 1 pack of bone cement, and revision arthroplasty. In most cases, the outcome of treatment using two-stage revision replacement was 80%. Overall, the auxiliary bacterial infections were recognized in three patients with tuberculous PJI and Staphylococcus aureus. Streptomycin and vancomycin were loaded in a cement spacer to increase the success rate, and tuberculous PJI was controlled for all patients. Conclusion: Tuberculous PJI can be controlled with two-stage revision replacement with an antibiotic-loaded cement spacer that is molded intraoperatively with custom mold and prolonged anti-tuberculosis treatment in all cases. Level of evidence: IV. [ABSTRACT FROM AUTHOR]
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- 2023
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86. Cure rate of infections is not an argument for spacer in two-stage revision arthroplasty of the hip.
- Author
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Adl Amini, Dominik, Wu, Chia H., Perka, Carsten, and Bäcker, Henrik C.
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TOTAL hip replacement , *HEMIARTHROPLASTY , *JOINT infections , *PERIPROSTHETIC fractures , *MICROBIAL cultures , *STAPHYLOCOCCUS epidermidis - Abstract
Introduction: A devastating complication after total hip arthroplasty (THA) is chronic periprosthetic joint infection (PJI). Most frequently spacers (Sp) with or without antibiotics are implanted in a two-stage procedure even though not always indicated due to unknown pathogen, femoral and acetabular defects or muscular insufficiency. Materials and methods: A retrospective analysis of a prospectively collected database was conducted, analyzing the treatment of 44 consecutive cases with chronic PJI undergoing two-stage revision using a Girdlestone situation (GS) in the interim period between 01/2015 and 12/2018. Diagnostics included intraoperative microbiological cultures, histological analysis, sonication of the initial implant, analysis of hip aspiration, as well as laboratory diagnostics and blood cultures. We analyzed the general and age-group-specific success rate of treatment using GS. Furthermore, we compared our data with the current literature on spacer implantation regarding common complications. Results: In total, 21 female and 23 male patients at a mean age of 59.3 ± 9.6 years were included. Age groups were divided into young, mid-age, and elderly. In most patients, microbiology revealed Staphylococcus epidermidis in 39.1% of cases, following Staphylococcus lugdunensis and Staphylococcus aureus in 10.9% after THA explantation. For histology, Krenn and Morawietz type 2 (infectious type) was diagnosed in 40.9%, type 3 (infectious and abrade-induced type) in 25.0%. With GS, the total cure rate was 84.1% compared to 90.1% (range 61–100%) using Sp as described in the literature. Among age-groups, cure rate varied between 77.8 and 100%. Other complications, which only occurred in the mid-age and elderly group, included the necessity of transfusion in 31.1%, and in total, one periprosthetic fracture was identified (2.3%). Conclusion: GS shows an acceptable cure rate at a minimum of 2 years when compared to the cure rate reported in the literature for Sp without major complications. For patients with increased risks for treatment failure using spacer, GS seems to be an alternative for chronic PJI when looking at the success rate of treatment. Level of evidence: III, Retrospective trial. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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87. Safety and tolerability of biodegradable balloon spacers in patients undergoing radiotherapy for organ-confined prostate cancer.
- Author
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Topazio, Luca, Narcisi, Federico, Tana, Fabio, Ciotta, Cosimo, Iossa, Vincenzo, Perna, Pasquale, Chiaramonti, Francesco, and Romantini, Federico
- Subjects
RADIOTHERAPY ,PROSTATE cancer ,INTENSITY modulated radiotherapy ,PROSTATE cancer patients ,RECTAL cancer ,PROSTATE - Abstract
Introduction: Radiotherapy is a common treatment for prostate cancer, and can be administered in various ways, including 3D conformal radiotherapy (3DCRT), intensity-modulated radiotherapy (IMRT) and hypo-fractionated radiation therapy. During treatment the gastrointestinal tract may be exposed to radiation and the rectal wall may be exposed to high doses of ionizing radiation, which can lead to rectal bleeding, ulcers or fistulas, and an increased risk of rectum cancer. Various strategies to minimize these complications have been developed in the last decade; one of the most promising is to use a rectal balloon to fixate the prostate gland during treatment or to inject biodegradable spacers between the prostate and rectum to reduce the rectal dose of radiation. Aim of our paper is to evaluate the safety and tolerability of spacers implantation. Materials and methods: From January 2021 to June 2022 all patients with a diagnosis of prostate cancer with unfavorable/intermediate risk - poor prognosis and programmed hypofractionated radiation therapy were enrolled. In all patients biodegradable balloons spacers were placed posteriorly to the prostate to increase the separation between prostate and rectum. The duration of the procedure, observation time, the appearance of early and late complications and their severity (according to Charlson comorbidity index) and tolerability of the device were recorded at the time of positioning and after 10 days. Results: 25 patients were enrolled in our study. Two patients (8%) underwent acute urine retention resolved with catheterization and one patient (4%) developed a mild perineal hematoma that did not require any treatment. As regards late complications 1 patient (4%) developed hyperpyrexia (> 38°C) the day after the procedure requiring continuation of antibiotic regimen. At T1 visit we recorded no medium-high grade complications. As for the tolerability of the device, it was optimal with no perineal discomfort or alterations of bowel function. Conclusions: Biodegradable balloon spacers appears to be safe and well tolerated and its positioning does not present any technical difficulties or risks of major complications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
88. Persistent Chronic Periprosthetic Joint Infection Treated with Three-Stage Revision Hip Arthroplasty: A Case Report.
- Author
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Ramadian, Nurul and Dinda Sedar, Jifaldi Afrian Maharaja
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TOTAL hip replacement ,HIP joint ,INFECTION ,REOPERATION ,BONE grafting - Published
- 2023
- Full Text
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89. Design and Analysis of a Symmetrical Low-κ Source-Side Spacer Multi-gate Nanowire Device.
- Author
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Gowthami, Y., Balaji, B., and Rao, K. Srinivasa
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NANOELECTRONICS ,NANOWIRE devices ,MILLIMETER waves ,NANOWIRES ,METAL oxide semiconductor field-effect transistors ,SILICON nanowires ,ELECTRIC capacity - Abstract
In this paper, we propose a symmetrical low-κ source-side spacer multi-gate nanowire device design and analysis. High-κ spacer materials are currently researched extensively for improving electrostatic control and suppressing short-channel effects in nanoscale electronics. However, the excessive increase in fringe capacitance of high-κ spacers degrades the dynamic circuit performance. Surprisingly, this approach achieves a significant reduction in gate capacitance by maximizing the use of high-κ spacer material. Three different structures, a symmetrical dual-κ spacer, symmetrical low-κ drain-side spacer, and symmetrical low-κ source-side spacer multi-gate nanowire MOSFET, are simulated, and the symmetrical low-κ source-side spacer multi-gate nanowire device is found to achieve lower gate capacitance. Simulations performed in Silvaco TCAD showed drain current (I
d ) of 4.9 A/mm, OFF-current (Ioff) of 9.54 × 10−12 A, transconductance (gm ) of 2.7 S/mm at Vgs = −0.4 V, cutoff frequency (fT ) of 560 GHz, drain conductance (gd ) of 0.657 S/mm, and ON-resistance (Ron ) of 0.6 ohm mm The proposed structure is thus applicable for next-generation terahertz/millimeter wave high-power applications and thus is highly recommended for digital applications. [ABSTRACT FROM AUTHOR]- Published
- 2023
- Full Text
- View/download PDF
90. Dose Distribution of High Dose-Rate and Low Dose-Rate Prostate Brachytherapy at Different Intervals—Impact of a Hydrogel Spacer and Prostate Volume.
- Author
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Haddad, Hathal, Hermani, Horst, Hanitzsch, Herbert, Heidrich, Albert, and Pinkawa, Michael
- Subjects
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TREATMENT effectiveness , *T-test (Statistics) , *RADIATION doses , *CHI-squared test , *DESCRIPTIVE statistics , *RADIOISOTOPE brachytherapy , *DATA analysis software , *PROSTATE tumors , *RADIATION dosimetry - Abstract
Simple Summary: Two different prostate brachytherapy methods are applied to treat prostate cancer: either a permanent implant of low-dose-rate (LDR-BT) sources or a temporary implant of high-dose-rate (HDR-BT) sources. This study aimed to compare the dose distributions, specifically focusing on the impact of a prostate-rectum spacer and prostate volume. The prostate dose coverage was comparable between different techniques. HDR-BT was characterized by a considerably more homogenous dose distribution and lower doses to the urethra. The minimum dose of up to 5 mm from the prostate was higher for larger prostates. As a consequence of the hydrogel spacer in HDR-BT patients, the intraoperative rectum dose was considerably lower, especially in smaller prostates. However, prostate volume dose coverage was not improved. The dosimetric results explain the clinical differences between the techniques reported in the literature. The study aimed to compare the dose distribution in permanent low-dose-rate brachytherapy (LDR-BT) and high-dose-rate brachytherapy (HDR-BT), specifically focusing on the impact of a spacer and prostate volume. The relative dose distribution of 102 LDR-BT patients (prescription dose 145 Gy) at different intervals was compared with the dose distribution of 105 HDR-BT patients (232 HDR-BT fractions with prescription doses of 9 Gy, n = 151, or 11.5 Gy, n = 81). A hydrogel spacer (10 mL) was only injected before HDR-BT. For the analysis of dose coverage outside the prostate, a 5 mm margin was added to the prostate volume (PV+). Prostate V100 and D90 of HDR-BT and LDR-BT at different intervals were comparable. HDR-BT was characterized by a considerably more homogenous dose distribution and lower doses to the urethra. The minimum dose in 90% of PV+ was higher for larger prostates. As a consequence of the hydrogel spacer in HDR-BT patients, the intraoperative dose at the rectum was considerably lower, especially in smaller prostates. However, prostate volume dose coverage was not improved. The dosimetric results well explain clinical differences between these techniques reported in the literature review, specifically comparable tumor control, higher acute urinary toxicity rates in LDR-BT in comparison to HDR-BT, decreased rectal toxicity after spacer placement, and improved tumor control after HDR-BT in larger prostate volumes. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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91. Novel Method to Reduce Electric Field Intensity on Gas-Insulated Switchgear Spacer with Conductor Topology.
- Author
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Hidayat, Syarif, Fabio, Muhammad Rizal, and Khayam, Umar
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ELECTRIC fields , *ELECTRIC field effects , *MOBILE geographic information systems , *TOPOLOGY - Abstract
Various method has been attempted to improve the reliability of Gas Insulated Switchgear (GIS) spacer by manipulating their shape and material. This paper discusses a novel simple approach to reduce electric field intensity on GIS spacer by manipulating the conductor shape inside it. To analyze its effect on electric field distribution, finite element analysis is done on 3 phase GIS spacer. An existing design is used as base analysis and modification to both its notches size and distance to the surface are modified. From the simulation, adding notches to spacer and bulge on the conductor may reduce electric field intensity on both the surface of the spacer and inside of the spacer compared to an unmodified cylindrical shape conductor design. This notches addition also helps with the added mechanical strength of the conductor and spacer. Keeping the notches size and moving it closer to the spacer surface will reduce electric field stress on the surface but will not reduce the maximum electric field occurring inside of the spacer. Last modification on its notches, by increasing its size, electric field intensity could be reduced by up to 68% and is observed as an optimal modification to the spacer design [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
92. Ohmic charging in capacitive deionization: Efficient water desalination using capacitive spacers.
- Author
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Nordstrand, Johan and Dutta, Joydeep
- Subjects
DEIONIZATION of water ,WATER use ,IONIC solutions ,CHONDROITIN sulfates ,ELECTRODES - Abstract
Capacitive deionization (CDI) is a promising desalination technology based on electrosorption on the surfaces of microporous electrodes. However, low total dissolved solids (TDS) in the water restricts its efficacy. In this work, we develop the theory of capacitive spacers (CS) in CDI. The investigations reveal a mechanism that we call ohmic charging; that is, the resistive losses in the spacer region drive adsorption in the CS. As a consequence, the obtained results show that such spacers can improve desalination efficiency, especially at ion‐starved conditions. The spacers also enhance the charging rate of the electrodes because the overall resistance is lower when the current can pass the spacer material instead of the solution, through the adsorption of anions on one side and cations on the other. Going deeper, the investigations reveal a major challenge; the spacer naturally discharges on the same timescale as the electrode charging timescale. However, only the fast timescale matters with low ionic content solutions, and under these conditions the CS are found to be superior. Put together, CS can make a significant difference, especially when the ion concentration is low or the cycle times are short. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
93. Treatment of Fracture-Related Infections with Bone Abscess Formation after K-Wire Fixation of Pediatric Distal Radius Fractures in Adolescents—A Report of Two Clinical Cases.
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Scharf, Markus, Walter, Nike, Rupp, Markus, and Alt, Volker
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ABSCESS treatment ,ANTIBIOTICS ,THERAPEUTIC use of biomedical materials ,INTERNAL fixation in fractures ,PERIOSTEUM ,HYDROXYAPATITE ,PERIOPERATIVE care ,DEBRIDEMENT ,RANGE of motion of joints ,BONE resorption ,RADIAL bone ,SURGICAL complications ,MAGNETIC resonance imaging ,STAPHYLOCOCCAL diseases ,ANTIBIOTIC prophylaxis ,CEFAZOLIN ,FRACTURE fixation ,SURGICAL site infections ,DISTAL radius fractures ,BONE grafting ,FRACTURE healing ,POLYMETHACRYLIC acids ,MICROBIAL sensitivity tests - Abstract
Closed reduction and K-wire fixation of displaced distal radius fractures in children and adolescents is an established and successful surgical procedure. Fracture-related infections after K-wire fixation are rare but can have significant consequences for the patient. There is a lack of literature on the treatment of K-wire-associated fracture-related infections in children and adolescents. Herein, we report two cases of fracture-related infection after initial closed reduction and Kirschner wire fixation in two adolescents. One 13-year-old boy and one 11-year-old girl were seen for fracture-related infections 4 and 8 weeks after closed reduction and percutaneous K-wire fixation of a distal radius, respectively. X-ray and magnetic resonance imaging (MRI) revealed a healed fracture with osteolytic changes in the metaphyseal radius with periosteal reaction and abscess formation of the surrounding soft tissue structures. A two-staged procedure was performed with adequate debridement of the bone and dead space management with an antibiotic-loaded polymethyl methacrylate (PMMA) spacer at stage 1. After infection control, the spacer was removed and the defect was filled with autologous bone in one case and with a calcium sulphate–hydroxyapatite biomaterial in the other case. In each of the two patients, the infection was controlled and a stable consolidation of the distal radius in good alignment was achieved. In one case, the epiphyseal plate was impaired by the infection and premature closure of the epiphyseal plate was noted resulting in a post-infection ulna plus variant. In conclusion, a fracture-related infection after Kirschner wire fixation of pediatric distal radius fractures is a rare complication but can occur. A two-stage procedure with infection control and subsequent bone defect reconstruction was successful in the presented two cases. Premature closure of the epiphyseal growth plate of the distal radius is a potential complication. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
94. Dissecting spacer induced membrane deformation and fluid hydraulic behavior in reverse osmosis.
- Author
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Deng, Rihong, Mo, Jiahao, Yang, Yang, Pei, Zhiqiang, and Li, Xianhui
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REVERSE osmosis , *COMPUTATIONAL fluid dynamics , *HYDRAULIC fluids , *HYDRAULICS , *DEFORMATIONS (Mechanics) - Abstract
Feed spacer is a key component of the spiral wound membrane module. However, the membrane deformation induced by the feed spacer under high pressure presents a significant challenge to long-term operation of reverse osmosis (RO) membrane. This deformation alters the fluid hydraulic behavior within the feed channel and its underlying mechanism remains elusive. In this study, the computational fluid dynamics (CFD) simulation was conducted to illustrate the impact of the feed spacer geometry on membrane deformation under high pressure and the resultant changes in hydraulic performances. The simulated results revealed that an increase in the mesh angle and a reduction in the filament diameter and length, led to a higher degree of membrane deformation. In addition, larger mesh angles and filament diameters, and shorter the filament lengths could significantly enhance the performance of the spiral wound membrane (SWM) module. This study provides an insight for the design of feed spacer to optimize the performance of reverse osmosis membrane module. [Display omitted] • Effect of spacer on RO membrane deformation was revealed for the first time. • The correlations exist among spacer geometry, membrane deformation and hydraulics. • Changing spacer parameters are able to reduce membrane deformation. • Membrane deformation amplified the influence of spacer parameters on hydraulics. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
95. Enhancing recovery of gold(III) from hydrochloric acid solutions using gemini surfactant microemulsions: The effect of spacer group.
- Author
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Lu, Guoqiang, Li, Xingyao, Zhou, Youbin, and Zhang, Yongmin
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PRECIOUS metals , *METAL wastes , *ELECTRIC potential , *SURFACE analysis , *BINDING constant - Abstract
[Display omitted] • Microemulsions based on gemini surfactant with different spacers were reported for gold recovery. • Outstanding extraction efficiency (>99 %) was obtained via microemulsion extraction. • Hydroxyl group in spacer greatly improves extraction performance due to a large binding constant. • Sulfate group in spacer discounts the extraction performance caused by partial neutralization. • Extraction process was optimized by response surface analysis. The recovery of precious metals from waste has garnered significant attention owing to their non-renewable nature and essential role in the burgeoning information industry. However, enhancing the extraction efficiency of microemulsions remains a significant challenge. In this study, three water-in-oil microemulsions were formulated using gemini surfactants with different spacers (14-OH-14, 14-SO 4 -14, and 14-3-14) as emulsifiers, supplemented with n-butanol as a cosurfactant, n-heptane as the oil phase, and NaCl aqueous solution as the internal aqueous phase. These microemulsions were employed for the extraction of gold(III) from hydrochloric acid solutions. The results illustrate that all three microemulsions effectively extracted gold(III) through a spontaneous, exothermic, enthalpy-driven anion-exchange mechanism, achieving notable extraction efficiency. In contrast to 14-3-14, incorporating –OH into the spacer significantly augments the positive electrostatic potential through the cationization of –OH in an HCl solution, resulting in a higher binding constant (2.43) and thereby improving the extraction efficiency. However, the presence of −SO 4 diminishes the positive electrostatic potential through partial neutralization, resulting in a lower binding constant (1.17), which is detrimental to the extraction process. Response surface optimization revealed that concentrations of C (14-OH-14) and V (1-butanol) significantly influence extraction efficiency and exhibit pronounced interaction. At optimal conditions (C (14-OH-14) = 0.09 mol·L−1, V (1-butanol) = 47.41 %, R=20, and C (NaCl) = 1.57 mol·L−1), over 95.54 % of gold(III) can be extracted from actual e-waste solutions. This study offers an alternative approach for designing or selecting surfactants in microemulsion-based extraction of gold(III) from e-waste. [ABSTRACT FROM AUTHOR]
- Published
- 2025
- Full Text
- View/download PDF
96. Comparative performance study of paperboard disposable spacers versus commercial valved holding chambers for aerosol delivery.
- Author
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Eynaud, Emma, Leclerc, Lara, Moreau-Neidhardt, Manon, and Pourchez, Jérémie
- Subjects
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METERED-dose inhalers , *PARTICULATE matter , *FLUTICASONE propionate , *CARDBOARD , *GRANULAR flow - Abstract
[Display omitted] The aim of this study is to evaluate and compare the performance, for the administration of fluticasone propionate with a pressurized metered-dose inhaler (pMDI), of two low-tech paperboard spacers versus two commercially available valved holding chambers (VHC). According to the Canadian standard CAN/CSA-Z264.1–02, total emitted dose (TED) and aerodynamic size distribution were measured for the pMDI in combination with 4 different spacers: a homemade paper cup spacer, the DispozABLE® paperboard spacer, the AeroChamber Plus® plastic VHC, and the Vortex® aluminium VHC. The two disposable paperboard spacers had a lower TED compared to the aluminium VHC, but delivered more than 2.5 times the dose of fluticasone than the commercial plastic VHC. The 3 antistatic devices (i.e. the aluminium VHC, the paperboard DispozABLE® spacer and the paper cup spacer) delivered a significantly higher dose of fine particles than the less antistatic plastic VHC. Their fine particle fraction was statistically similar to that obtained with pMDI without spacer. This respirable fraction ensures an optimal therapeutic effect. All spacers limited the flow of coarse particles, thus avoiding adverse effects on the trachea and oropharynx. We have shown that inexpensive and low-tech paperboard spacers are interesting alternatives for the administration of aerosols. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
97. CrisprVi: a software for visualizing and analyzing CRISPR sequences of prokaryotes
- Author
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Lei Sun, Jinbiao Wang, Fu Yan, Gongming Wang, Yun Li, and Jinlin Huang
- Subjects
CRISPR ,Direct repeat ,Spacer ,Visualization ,Statistics ,Consensus sequence ,Computer applications to medicine. Medical informatics ,R858-859.7 ,Biology (General) ,QH301-705.5 - Abstract
Abstract Background Clustered regularly interspaced short palindromic repeats (CRISPR) and their spacers are important components of prokaryotic CRISPR-Cas systems. In order to analyze the CRISPR loci of multiple genomes more intuitively and comparatively, here we propose a visualization analysis tool named CrisprVi. Results CrisprVi is a Python package consisting of a graphic user interface (GUI) for visualization, a module for commands parsing and data transmission, local SQLite and BLAST databases for data storage and a functions layer for data processing. CrisprVi can not only visually present information of CRISPR direct repeats (DRs) and spacers, such as their orders on the genome, IDs, start and end coordinates, but also provide interactive operation for users to display, label and align the CRISPR sequences, which help researchers investigate the locations, orders and components of the CRISPR sequences in a global view. In comparison to other CRISPR visualization tools such as CRISPRviz and CRISPRStudio, CrisprVi not only improves the interactivity and effects of the visualization, but also provides basic statistics of the CRISPR sequences, and the consensus sequences of DRs/spacers across the input strains can be inspected from a clustering heatmap based on the BLAST results of the CRISPR sequences hitting against the genomes. Conclusions CrisprVi is a convenient tool for visualizing and analyzing the CRISPR sequences and it would be helpful for users to inspect novel CRISPR-Cas systems of prokaryotes.
- Published
- 2022
- Full Text
- View/download PDF
98. Investigation of Growth of Microorganisms within the Spacers of Children with Cystic Fibrosis
- Author
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MA Moslehi and F Ghasemi Najafabadi
- Subjects
microorganism ,spacer ,children ,cystic fibrosis ,Medicine (General) ,R5-920 - Abstract
Background & aim: Cystic fibrosis is a monogenic disorder in several systems. Since spacers used by these patients may be used several times a day, many of them do not know how to wash and use them, so these devices are good places for bacteria to grow. Therefore, this study was performed to identify and determine the relationship between the growth of microorganisms inside spacers and the effect of washing on possible microbial infections in patients with cystic fibrosis. Methods: This is an intervention pilot study to determine the effect of the growth of microorganisms in the spacer of patients with cystic fibrosis on the exacerbation of pulmonary involvement. In the present study, 30 people were examined as a pilot sample due to the lack of a similar study. Patients were selected from children with cystic fibrosis referred to Imam Reza clinic. The target group was patients with a positive sputum culture (throat). At first, after the last use of a spacer, the culture was taken from the sputum and the inner surface of the spacer. Patients with a positive culture were instructed to wash their spacers in the second step. Washing was done daily after each use and immersion in sterile vinegar solution for 20 minutes and then rinsing and drying spontaneously in air and sun twice a week. After four weeks, the initial questionnaire was completed again for patients, and the change in clinical status was assessed. The error level of the first type was considered equal to 0.05. SPSS software version 26 was used for analysis. Results: In this study, 30 participants with a mean age of 7.51 (4.21) with a maximum age of 18 years and a minimum of 1.5 years. 19 (63.3) were boys, and 11 (36.7) were girls. None of the demographic and clinical variables were significant on the growth of microorganisms within the spacers in patients with cystic fibrosis. Sixteen patients (53.3%) had negative spacer culture, and 14 patients (46.6%) had positive spacer culture, of which 7 of them had the same result of sputum and throat culture, and in 7 patients, it was different. A 4-week period of using sterile vinegar (as mentioned) to wash spacer and educate families to observe spacer hygiene was performed again from the culture machine, all of which had 14 negative cultures. Conclusion: It seems that contamination of the spacers used by patients is a relatively common finding (46.6% of patients). Due to the physical condition of these children and their susceptibility to respiratory infections, they may act as a source for microbial infections. Patients with a positive spacer culture had more hospitalizations than patients with a negative culture, which can confirm the relationship between spacer contamination and pulmonary exacerbation of these patients. Therefore, educating patients about hygiene and regular washing of the respiratory tract in children with Cystic fibrosis is strongly recommended.
- Published
- 2022
99. Spacer effects on thermal-hydraulic performance of fluid flow at supercritical pressure in annular channel - CFD methodology
- Author
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S.K. Dhurandhar, S. L. Sinha, and S.K. Verma
- Subjects
heat transfer performance ,spacer ,numerical simulation ,supercritical pressure ,annulus flow ,flow characteristic ,Mechanical engineering and machinery ,TJ1-1570 ,Mechanics of engineering. Applied mechanics ,TA349-359 - Abstract
Spacer is a vital component in assembly of nuclear fuel rod bundles. It is used to support and maintain suitable distance between the rods in assembly of nuclear fuel bundle. Spacer promotes the local heat transfer in downstream to the spacer in rod bundle. The objective of present work is to analyse the spacer effects on thermal and hydraulic performance of R-134a at supercritical condition of pressure 4.5 MPa in an annular flow. A Computational Fluid Dynamics (CFD) code ANSYS Fluent has been used for present numerical analysis and SST (Shear Stress Transport) k-ω turbulence model was considered for turbulence flow analysis. Numerical analysis was carried out in an annular channel of 6 mm hydraulic diameter with spacer, located at middle of channel. Hydraulic and thermal performance due to the spacer have been investigated for three different mass flow rates (0.33175, 0.41469 and 0.53909 kg/s) and three different heat fluxes (60, 100 and 160 kW/m2 ). Two blockage ratios of 0.3 and 0.38 have been used in present analysis. Due to the presence of spacer as flow obstruction, it is observed that at spacer location, velocity increased significantly and subsequent decrease in pressure. Also; it is noticed that the wall temperature is decreased and corresponding coefficient of heat transfer enhanced significantly at the location of spacer in annular channel. The observed value of ratio of Nusselt number for the case of spacer and without spacer (Nu/Nu*) shows better agreement with correlations data for flow obstacle at Re=97000.
- Published
- 2022
- Full Text
- View/download PDF
100. Asymmetric Thermal and Water Vapor Transport of Polyester Spacer and Cotton Nonwoven Fabric Assembly
- Author
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Qing Chen, Dahua Shou, Chao Sun, Bailu Fu, Rong Zheng, and Jintu Fan
- Subjects
thermal resistance ,water vapor resistance ,spacer ,nonwoven ,asymmetric ,Science ,Textile bleaching, dyeing, printing, etc. ,TP890-933 - Abstract
Spacer fabric is often used in cushions, footwear, filter material, and other products because of its high air permeability and three-dimensional (3D) structure. However, for practical applications, it is typically combined with other materials. We investigated the thermal properties and water vapor permeability of assembly-combined thicker spacer (16 mm) and various cotton nonwoven fabrics. The assembly-combined lightest nonwoven (30 g/m2) and spacer fabric exhibited the highest thermal resistance, increasing by 66.62% compared with the bare spacer fabric; however, no significant difference was observed when combined with the heaviest woven fabric (60 g/m2). Furthermore, the fabric arrangement during assembly could affect the heat and moisture-transfer efficiencies. The assembly-combined lightest nonwoven (30 g/m2) and spacer fabric under the upward test condition exhibited the highest thermal resistance, highest Clo, lowest heat transfer coefficient, highest insulation ratio, and lowest evaporation resistance among all assemblies. Higher thermal resistance and lower evaporative resistance could benefit physiological comfort. However, the assembly-combined heaviest nonwoven and spacer fabric under the downward test condition exhibited similar thermal resistance to the spacer fabric and the highest evaporation resistance. The asymmetric heat- and moisture-transfer properties of a porous assembly can contribute toward developing new materials for applications in other engineering fields.
- Published
- 2023
- Full Text
- View/download PDF
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