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L'objectif de cette mise au point était de rapporter les modalités/indications de la radiothérapie (RT) stéréotaxique dans le cancer de la prostate (CaP) localisé, ainsi que d'expliquer le rôle de l'urologue dans cette préparation à l'irradiation. Une recherche sur la base de données PubMed et un examen narratif des articles ont été effectués en Décembre 2023 afin de proposer une revue compréhensive de la littérature sur le sujet. Seuls les articles en français ou en anglais ont été examinés. La RT stéréotaxique, ou en conditions d'hypofractionnement extrême, délivre généralement 35–40 Gy en 5 séances, guidée par l'image et en modulation d'intensité. Dans le traitement primaire du CaP localisé, la RT stéréotaxique est indiquée chez les patients à risque faible ou intermédiaire favorable, sans association à une hormonothérapie, chez des patients sélectionnés et dans des centres experts, selon les données d'efficacité de l'essai HYPO-RT-PC, et des données de sécurité de l'essai PACE-B. Dans le traitement de rattrapage après traitement primaire non chirurgical, la (ré)-irradiation stéréotaxique semblerait apporter des résultats oncologiques similaires aux autres modalités de traitement. Récemment, l'essai de phase I du GETUG-31 a comparé 2 schémas de RT stéréotaxique et rapportés des résultats encourageants dans cette indication. Le rôle de l'urologue est primordial avant RT stéréotaxique et une description de la préparation consistant en la mise en place de fiduciaires et de Spacer est proposée (https://www.urofrance.org/formation/pose-de-fiduciaires-et-spacer-par-voie-transperineale/) La RT stéréotaxique du CaP localisé est une thérapie aux indications croissantes, ou la collaboration urologue-radiothérapeute est primordiale. The aim was to report the modalities/indications of stereotactic body radiotherapy (SBRT) in localized prostate cancer (PCa) and to explain the role of the urologist in preparing for irradiation. A PubMed database search and narrative review of articles was performed in December 2023 to provide a comprehensive review of the literature on the subject. Only articles in French or English were examined. SBRT generally delivers 35-40 Gy over 5 sessions, image-guided and intensity-modulated. In the primary treatment of localized CaP, SBRT is indicated in patients at low or favorable intermediate risk, without combination with androgen deprivation therapy, in selected patients and in expert centers, based on efficacy data from the HYPO-RT-PC trial, and safety data from the PACE-B trial. Stereotactic (re)irradiation would appear to provide similar oncological results to other treatment modalities, in the case of salvage treatment after primary non-surgical treatment. The results of the GETUG-31 trial are encouraging, but larger comparative studies are still needed to clarify the place of SBRT in this indication. The role of the urologist is paramount prior to SBRT, and a description of the preparation consisting in the placement of gold markers and Spacer is proposed (https://www.urofrance.org/formation/pose-de-fiduciaires-et-spacer-par-voie-transperineale/) SBRT in localized CaP is a therapy with growing indications, where urologist-radiotherapist collaboration is crucial. [ABSTRACT FROM AUTHOR]

Mixing in gas separation membranes has received much less attention than in membrane liquid separation because gas molecules have much smaller viscosity, allowing them to diffuse easily through membranes without requiring significant flow mixing. However, due to advancements in membrane fabrication technologies aimed at improving material properties, concentration polarization (CP) might become an issue in gas separation due to enhanced membrane efficiency and permeability. Consequently, a 2D CFD analysis is conducted to evaluate the impact of spacer-induced mixing on membrane gas concentration polarization for typical CO 2 /CH 4 gas separation. Results show that spacers generally enhance flux performance while reducing CP in the membrane channel when compared to the case without spacers. Furthermore, the effectiveness of spacer-flux-to-pressure-loss-ratio (SPFP) reaches a peak for a Reynolds number in the range of 5 < Re h < 200 because of the trade-off between flux and pressure drop. This mixing-induced flux enhancement is most effective under high CP conditions (less mixing) within the membrane channel. Similarly, flux enhancement due to spacers can be observed as membrane selectivity, pressure ratio and feed gas concentration increase due to enhanced CP. [Display omitted] • 2D CFD analysis of the impact of spacer-induced mixing on membrane gas separation. • The spacer-flux-to-pressure-loss-ratio reaches a peak at 5 < Re h < 200. • Spacer reduces CP and enhances gas permeation flux compared with empty channel. • Spacer is most effective in enhancing gas permeate flux under high CP conditions. • Spacer enhances flux as selectivity, pressure ratio and feed concentration increase. [ABSTRACT FROM AUTHOR]

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]

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]

[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]

[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]

• Electron delocalization enhances the photostability of 2D/3D perovskite films and solar cells. • Uniform electron distribution in conjugated spacer molecules effectively passivate the trap states in 2D/3D perovskite films. • Values of J sc and V oc observed for solar cells based on conjugated spacer molecules are considerably enhanced. • Electron delocalization is essential for the design of photostable and efficient solar cells. Photodegradation and defect passivation of hybrid metal halide perovskites are still challenges toward related highly stable optoelectronic devices such as solar cells. Herein, we show that photodegradation and defect density can be drastically reduced in 2D/3D perovskites by engineering the conditions for carrier delocalization. For this purpose, conjugated, partially conjugated and non-conjugated spacer molecules of similar sizes as well as n values have been systematically changed in 2D/3D perovskites based on archetypical MAPbI 3. The decrease of calculated HOMO-LUMO gaps of complexes with spacer molecules (E HL-complex) correlated well with the decrease of the Urbach energy, the decrease of the trap-state density, and the strong reduction of photodegradation of 2D/3D perovskite films, whereas the photodegradation was practically independent of the n value for conjugated spacer molecules. In addition, the short circuit current density (J sc) and open circuit voltage (V oc) of the prepared solar cells increased with decreasing E HL-complex ; hence, maximum initial values of J sc and V oc larger than those of identically prepared reference solar cells based on 3D MAPbI 3 were reached. We also demonstrate that the photodegradation of solar cells decreased monotonously with increasing initial power conversion efficiency. Thus, delocalization by optimum coupling of electron wavefunctions between conjugated spacer molecules and binding moieties at the perovskite enhances defect passivation and strongly reduces photodegradation in 2D/3D perovskites. [ABSTRACT FROM AUTHOR]

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This work presents a novel three-channel Tree-FET optimized for superior DC and analog performance metrics. The device structure features nanosheets with a width (NS WD) of 9 nm, a thickness (NS TH) of 5 nm, and interbidge dimensions of 8 nm in height (IB HT) and 5 nm in width (IB WD). The Tree-FET demonstrates an exceptional on/off current ratio of 107 through meticulous engineering, significantly outperforming conventional FET configurations. Our comprehensive study explores the effects of different spacer materials, including HfO 2 , Al 2 O 3 , Si 3 N 4 , and SiO 2 , across varied channel lengths. The superior dielectric properties of HfO 2 contribute to fine-tuning the device's characteristics, making it a standout choice for optimizing performance. Out of all HfO 2 has been found to perform exceptionally well, offering the best combination of electrostatic control and minimized leakage currents. Because the Tree-FET has better electrostatic integrity and can keep working well with different spacer materials and channel lengths, it has much potential as a flexible and valuable part for next-generation semiconductor devices. The promising DC and analog metrics achieved through this novel design pave the way for developing more compact, high-performance electronic components. • Novel Device Introduction. • Presentation of a three-channel Tree-FET optimized for superior Dc and analog performance. • Device Structure: • Nanosheet with a width (NS WD) of 9 nm and thickness of (NS TH) of 5 nm. • Interbridge dimensions: 8 nm in height (IB HT) and 5 nm in width (IB WD). • Performance Metrics. • In the existing literature Tree-FET with 2 channels were explored. But for the first time I proposed a novel device with three channels by varying different spacer materials at various channel lengths (12 nm–20 nm) which will optimize the device performance. • By adding extra interbridge enhance the performance metrics like exceptional On-Current (10−5), Off Current (10−12) and On -Off current ratio (107), outperforming conventional FETs. • Spacer Material Study: • Analysis of different spacer materials: HfO 2 , Al 2 O 3 , Si 3 N 4 , and SiO 2. • HfO 2 found to offer the best electrostatic control and minimized leakage currents. • Dielectric Properties: • HfO 2 's superior dielectric properties contribute to fine-tuning device characteristics. • Versatility and Efficiency: • Tree-FET maintains robust performance across varied spacer materials and channel lengths. • Potential as a versatile and efficient component for next generation semiconductor devices. • Implications: • Promising DC and analog metrics (g m ,g ds ,TGF,TFP, GFP and f T) pave the way for developing more compact and high-performance electronic components. [ABSTRACT FROM AUTHOR]

This paper introduces new feed spacer geometry for the forward osmosis (FO) membrane modules in an attempt to achieve more water flux than conventional models. The geometry is based on a mesh with star- shaped cross-section filaments, and it is optimized by using the response surface methodology (RSM) with a central composite design (CCD) in a series of numerical simulations. Filament thickness, filaments distance, and curvature radius are evaluated as main geometry parameters, while pressure drop and water flux are observed as responses. Two models are extracted with R2 of more than 99%. Results show the filament thickness and distance have a highly significant effect on responses. Simultaneous optimization of water flux and pressure drop predict the best results would be obtained with a filament thickness of 0.4 mm, a filament distance of 2.32 mm, and a curvature radius ratio of 0.7 with a desirability of 0.66. The vertical movement of filaments in the channel, zigzag, and uniform mode, negatively affect the spacer performance. The results of the newly developed spacer were compared with those of a commercial spacer with 31 mil thickness. The optimized spacer achieved 8% more water flux than the commercial 31-mil spacer in the proposed conditions. This research shows that the newly developed FO spacers could improve the performance of this process. [ABSTRACT FROM AUTHOR]

The initial presentation of a mucinous adenocarcinoma of the appendix can be a peri-appendicular abscess. The abdominal wall muscles can be invaded during radiological or surgical drainage. The management of such a tumour is complex. The resection of a drainage route can be uncertain and R1. In this case, further treatment with adjuvant radiotherapy may be necessary. One possible deleterious side effect of radiotherapy on the abdominal wall is radiation injury to the bowel. As a preventive measure, a spacer (here a breast prosthesis) can be interposed. [ABSTRACT FROM AUTHOR]

Two new random donor-acceptor (D-A) copolymers, signed as P1 and P2, were designed and synthesized. Electrochemical and spectroelectrochemical measurements were performed to investigate absorption, energy levels, electronic and optical band gaps for comparison. The polymers were used as donor polymers in the active layer to fabricate non-fullerene, bulk heterojunction (BHJ) organic photovoltaics (OPVs). Investigations were carried out through the conventional BHJ structure; ITO/PEDOT: PSS/Active Layer/LiF/Al, where active layer consists of 3,9-bis(2-methylene-(3-(1,1-dicyanomethylene)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2′,3′-d']- s -indaceno[1,2-b:5,6-b']dithiophene (ITIC) as the acceptor and thienopyrroledione containing donors. The device based on P1:ITIC(1:1) blend with a thickness of 161 nm gave the best performance with a power conversion efficiency (PCE) of 7.94%, an open-circuit voltage (V OC) of 0.86 V, a short-current density (J SC) of 18.45 mA cm−2 and a fill factor (FF) of 50.12%. The highest PCE obtained from P2 based organic solar cell is 1.96%. P2 exhibited low solubility attributed to the lack of alkyl groups enhancing polymer solubility, electronic properties, and photovoltaic performances. The research outputs exhibit that introduction of alkyl chains on the polymer backbone can enhance device performance. [Display omitted] • Two new random copolymers based on thienopyrroledione (TPD) were synthesized. • Polymers were used as donor materials in non-fullerene BHJ OPVs. • Effect of introduction of alkyl chains on device performance was investigated. • The best result for power conversion efficiency was found to be 7.94%. • Alkyl chains' effect on OPVs' performance is investigated. [ABSTRACT FROM AUTHOR]

[Display omitted] • Impact of flow promoters was elucidated through experiments and CFD simulations. • Same-sized 3D-printed flow promoters were tested in membrane distillation process. • Patterned module maintained sustained flux (up to VCF 2), 33% longer than spacer. • Patterned module showed enhanced resistant to scale formation on membrane surface. This study addresses the challenges of membrane distillation (MD), such as polarization effects, membrane scaling and fouling, and pore wetting, by introducing flow promoters (spacer, membrane module, and patterned membrane) to enhance MD performance. Utilizing 3D printing technology, we fabricated these flow promoters and employed computational fluid dynamics (CFD) simulations to evaluate different pattern designs and predict their impact on MD membrane scaling formation. The simulation outcomes guided the selection of a square pattern for the flow promoter, which demonstrated promising results. While the spacer and patterned membrane exhibited dead zones that limited MD performance, the patterned module presented rapid flow velocity with minimal dead zones. Compared to the spacer, the patterned module maintained a constant flux until a volume concentration factor of 2.0, prolonging operation by 33 %. Observation also revealed reduced crystal attachment on the membrane surface when using the patterned module, suggesting effective prevention of scale formation. These findings underscore the importance of modulation studies, particularly highlighting the superior efficiency of the patterned module over other flow promoters. Therefore, this study advocates for modulation strategies, such as the patterned module, as optimized approaches to enhance MD performance by mitigating scaling formation. [ABSTRACT FROM AUTHOR]

Using an inert spacer UGH2, we have selectively separated the exciplex that forms between the TCTA donor and PO-T2T acceptor. We observed distinct emission behavior due to the interplay of ΔE ST (singlet–triplet energy difference) and E a (activation energy) concerning the donor–acceptor (D-A) distance. At a separation distance of 1 nm, we observed the maximum intensity of exciplex emission indicating optimum condition in this system. [Display omitted] • The research investigated the interaction between TCTA and PO-T2T, specifically focusing on the long-range exciplex formation. By introducing a UGH2 inert spacer layer, they explored how this affected the exciplex characteristics. • The study observed distinct emission behavior arising from the interplay of several factors: k r (rate constant for radiative decay), k RISC (rate constant for intersystem crossing), ΔE ST (energy difference between singlet and triplet states), and E a (activation energy). These parameters collectively influenced the exciplex properties. • At a separation distance of 1 nm, a delicate balance between k r and ΔE ST facilitated the emergence of exciplex emission. This finding shed light on the systematic changes in photophysical parameters associated with exciplex D-A behavior. Exciplexes are crucial in organic optoelectronic devices since well-elaborated charge-transfer (CT) complexes exhibit unique exciton generation behavior. Thus, understanding the CT energy structures with exciton dynamics depending on donor–acceptor separation distances is essential for extracting their full potential. In this study, we investigated a long-range exciplex behavior between the electron donor of tris(4-carbazoyl-9-ylphenyl)amine (TCTA) and the electron acceptor of 2,4,6-tris[3-(diphenylphosphinyl)phenyl]-1,3,5-triazine (PO-T2T) by finely controlling their distance with 1,4-bis(triphenylsilyl)benzene (UGH-2) as a spacer layer. We report the characteristic exciplex photophysical kinetic behavior with time-dependent dynamics in terms of the donor–acceptor distance associated with the singlet–triplet energy gap and activation energy variation. [ABSTRACT FROM AUTHOR]

Inorganic material (scale) precipitation on reverse osmosis (RO) membranes is a serious issue in plants because performance recovery via cleaning is challenging, and the replacement expenses are enormous. This study investigated the calcium sulfate scaling phenomena on membranes using a flat membrane cell with a spacer to model a spiral wound-type RO element. Subsequently, the mass transfer coefficient of the flat membrane cell with the spacer and the convergent value of permeate flux due to solute precipitation were determined. The dimensionless equation for the mass transfer coefficient of the cell with the spacer could be expressed using the dimensionless equation for the mass transfer coefficient of a flat membrane cell without a spacer. The behavior in permeate flux due to the precipitation of calcium sulfate on the RO membrane of the cell with the spacer was analyzed based on the scaling-based critical flux and scaling index, which discriminate scale precipitation. Finally, scale precipitation experiments were conducted by varying spacers and the operating conditions of pressure, solute concentration, temperature, and Reynolds number; the permeate flux was confirmed to converge to the scaling-based critical flux, and the scaling index could discriminate the operating condition area of scale precipitation. [Display omitted] • Investigated calcium sulfate scaling phenomena on membranes with/without spacer. • Expressed mass transfer coefficients of cells with/without spacer using same equation. • Permeate fluxes with/without spacer converge to the scaling-based critical fluxes. • S caling index with/without spacer discriminates whether scale precipitation occurs. [ABSTRACT FROM AUTHOR]

Introduction: Bioactive glass S53P4 (BAG-S53P4) has been used in the treatment of osteomyelitis with excellent results. The aim of this study was to evaluate the clinical and radiographic results of patients treated with use of antibiotic-loaded cement beads, followed by bone defects filling using bioglass.Methods: We treated a prospective series of patients presenting with acute or chronic osteomyelitis of a long bone of the upper or lower limb. The first-stage procedure involved debridement and filling of cavitary defects with antibiotic-loaded polymethylmethacrylate (PMMA) beads. When signs of infection subsided, the defects were filled with BAG-S53P4. The main outcomes assessed were the reinfection rate, need for reoperation, radiographic and functional evaluations (DASH and Lysholm scores).Results: Ten patients were included, aged between 4 and 66 years (mean 25.4 years). The source of infection was hematogenic in five cases and post-traumatic in the other five. Hematogenic infections required two debridements before filling with bioglass, whereas post-traumatic cases required only one. The time between the first debridement and the application of bioglass varied from 1 to 63 weeks (average of 17 weeks). All patients showed a favorable evolution after bioglass procedure, with no need for reoperation or relevant wound problems. The radiographic evaluation showed partial incorporation of the material and adequate bone formation, and functional scores were satisfactory in all cases.Conclusion: The treatment of osteomyelitis with surgical debridement and PMMA beads, followed by filling of bone defect with BAG-S53P4, was effective in all patients evaluated, with adequate infectious control and bone regeneration. No cases required reoperation after bioglass implantation. Patients with hematogenous osteomyelitis required a greater number of debridements before filling with bioglass. [ABSTRACT FROM AUTHOR]

Background: High rates of spacer-related complications in two-stage exchange total hip arthroplasty (THA) have been reported. Patients with advanced bone defects and abductor deficiency may benefit from a nonspacer two-stage revision. This study reports on the clinical course of a contemporary two-stage exchange for periprosthetic hip infection without spacer insertion.Methods: We reviewed 141 infected THAs with extensive bone loss or abductor damage who underwent two-stage exchange without spacer placement. The mean duration from resection arthroplasty to reimplantation was 9 weeks (2-29). Clinical outcomes included interim revision, reinfection, and aseptic revision rates. Restoration of leg-length and offset was assessed radiographically. Modified Harris hip scores were calculated. Mean follow-up was 5 years (3-7). Treatment success was defined using the modified Delphi consensus criteria.Results: Thirty-four patients (24%) had treatment failure, including 13 reinfections, 16 interim redebridements for persistent infection, 2 antibiotic suppressive therapies, and 3 prosthetic joint infection-related deaths. Aseptic rerevision after reimplantation was necessary in 14 patients (10%). Dislocation accounted for most aseptic complications, with 20 dislocations occurring in 15 patients (11%). Leg-length and offset were restored to preoperative measures. Mean modified Harris hip scores significantly improved from 35 points to 67 points.Conclusion: A nonspacer two-stage exchange is a viable option for managing chronically infected THA with severe bone loss or abductor deficiency, showing comparable rates of interim revision and recurrence of infection. Cementless reimplantation demonstrates good midterm survivorship with comparable functional outcomes and leg-length restoration. However, dislocation continues to be a major concern. [ABSTRACT FROM AUTHOR]

Background: The purpose of this randomized clinical trial is to compare perioperative and postoperative variables between static and articulating spacers for the treatment of chronic periprosthetic joint infection (PJI) complicating total hip arthroplasty (THA).Methods: Fifty-two patients undergoing resection arthroplasty as part of a 2-stage exchange for PJI at 3 centers were randomized to either a static (n = 23) or articulating spacer (n = 29). The primary endpoint was operative time of the second-stage reimplantation and power analysis determined that 22 patients per cohort were necessary to detect a 20-minute difference. Seven patients were lost to follow-up, 4 were never reimplanted, and one died before discharge after reimplantation. Forty patients were followed for a mean 3.2 years (range 2.0-7.1).Results: There were no differences in operative time at second-stage reimplantation (143 minutes static vs 145 minutes articulating, P = .499). Length of hospital stay was longer in the static cohort after stage 1 (8.6 vs 5.4 days, P = .006) and stage 2 (6.3 vs 3.6 days, P < .001). Although it did not reach statistical significance with the numbers available for study, nearly twice as many patients in the static cohort were discharged to an extended care facility after stage 1 (65% vs 30%, P = .056).Conclusion: This randomized trial demonstrated that the outcomes of static and articulating spacers are similar in the treatment of THA PJI undergoing 2-stage exchange arthroplasty. The significantly longer length of hospital stay associated with the use of static spacers may have important economic implications for the health care system. [ABSTRACT FROM AUTHOR]

La radiothérapie stéréotaxique dans le traitement du cancer de la prostate localisé est pourvoyeuse de toxicités rectales, qui peut être réduite en utilisant un espaceur rectal. L'objectif de cette étude rétrospective était de démontrer la faisabilité d'une implantation sous anesthésie locale et l'utilité d'un espaceur dans la réduction de la dose dans la paroi rectale. Nous avons recueilli les données de l'ensemble des patients atteints d'un adénocarcinome de la prostate localisé traité par irradiation stéréotaxique de 40 Gy (en cinq fractions) entre 2018 et 2020. Un espaceur (SpaceOAR®) a été mis en place en fonction de la disponibilité du dispositif. Nous avons relevé des indicateurs dosimétriques concernant le volume cible et les organes à risque. Les valeurs continues ont été représentées par leurs moyennes et comparées avec un test de Mann–Whitney. Parmi les 35 patients d'une moyenne d'âge de 75 ans, 17 ont bénéficié de la pose d'un espaceur rectal, sans complication lors de l'implantation, permettant un espacement moyen de 10 mm. Les fortes doses dans la paroi rectale étaient significativement plus basses avec l'espaceur (volume recevant 38 Gy et plus [V38] : 0,39 cm3 contre 0,72 cm3 ; p = 0,02). Il y avait une tendance à une meilleure couverture du volume cible prévisionnel (PTV) avec l'espaceur (p = 0,07). Les doses reçues par la paroi vésicale étaient similaires entre les deux groupes. L'implantation sous anesthésie locale d'un espaceur rectal est faisable, et s'accompagne d'une diminution de la dose dans le rectum, avec une meilleure couverture du PTV. Stereotactic body radiotherapy (SBRT) of prostate cancer is associated with rectal toxicities, which can be reduced by using a hydrogel spacer. The object of this retrospective study was to show the feasibility of spacer placement under local anesthesia and utility of hydrogel spacer to reduce the dose to the rectal wall. We collected data from all patients with localised prostate cancer treated with SBRT (40 Gy in 5 fractions) between 2018 and 2020. A hydrogel spacer (SpaceOAR®) was placed depending on the availability of the product. We collected dosimetric data for target volumes and organs at risk. We calculated mean values, which were compared using non-parametric tests. Among 35 patients, mean age was 75 years. Seventeen had a spacer placed, with a mean space created of 10 mm. No complication was reported during the intervention. High doses to the rectal wall were significantly lower in spacer group (V38: 0.39 cm3 vs. 0.72 cm3; P = 0.02). PTV were better covered in spacer group (P = 0.07). Doses to the bladder wall were similar in both groups. Spacer procedure under local anesthesia was well tolerated. Hydrogel spacer allowed to reduce doses to the rectum while improving PTV coverage. [ABSTRACT FROM AUTHOR]

Infection after total elbow arthroplasty (TEA) is a difficult problem for both patients and surgeons. When two-stage revision is required, a custom antibiotic laden articulating spacer fashioned using Ilizarov external fixation rods allows for a functional elbow prior to revision. The purpose of this review and case series is to investigate clinical and patient reported outcomes of the articulating spacer and investigate its effectiveness as bridge prosthesis and a long-term option prior to revision. A retrospective review between 2016 and 20 identified patients with an infected TEA treated with an articulating spacer. Patient age, surgical indication, spacer duration, and comorbidities were recorded. Outcome scores included Visual Analog Scale (VAS) for pain (1-10), Single Assessment Numerical Evaluation (SANE) (0-100%) of overall elbow function, and range of motion at the pre-spacer, three month, and most recent follow-up visit. Statistical analysis compared outcomes at each time period using an analysis of variance or Friedman's test followed by post-hoc analyses using paired t-tests or Sign tests. Minimal Detectable Change (MDC) was calculated for pain and SANE scores. Eleven articulating spacers (9 patients) with 13 months mean spacer implantation were identified. Mean long-term spacer implantation (4 patients, 6 spacers) was 22 months (range 7-40). Median pain scores were significantly lower at three month and latest follow-up relative to preoperative assessment. Analysis of long term spacers revealed a significant decrease in pain scores from pre-op to 3 months. Analysis of SANE scores demonstrated three month and latest follow-up scores to be significantly improved from preoperative assessment. SANE scores for long-term spacers were significantly improved at three months and last follow-up. Range of motion analysis demonstrated no significant differences other than significantly increased pronation/supination at three months in long term spacers. Eight of 11 spacers met MDC for pain and 5/11 for SANE at three months. Three of 6 long-term spacers met MDC for SANE. Total implant cost is $158.32. Most spacers are effective in clearing infection, but a custom articulating spacer importantly provides significant, early pain relief and improved patient reported function of the elbow. Improvements in range of motion are also achieved. An articulating spacer allows for an improved quality of life during the interim period prior to revision as well as a long-term option providing sustained improvement in function for those unwilling to undergo further surgery or with complex medical issues that preclude them from a definitive revision. Level IV; Case Series [ABSTRACT FROM AUTHOR]

Background: Total hip arthroplasty (THA) is one of the most successful operations in all of medicine in improving patient pain and restoring function. However, complications do arise after primary and revision THA. Dislocation of a THA, also known as instability, occurs in 1-2% of primary THAs and up to 30% of revision THAs. Most dislocations in the United States are initially managed with closed reduction under procedural sedation in emergency departments (EDs) by on-call orthopedists or emergency medicine specialists.Objective: In this review the characteristics of the articulations that may require closed reduction in the ED are described, as well as their radiographic findings prior to reduction. Finally, we present subtle radiographic findings associated with failed closed reductions.Discussion: Due to the different types of implants that have been introduced, closed reduction can be challenging in certain cases. Iatrogenic intraprosthetic dislocations are becoming more common with the increased use of dual-mobility liners. There are also dislocations after staged revision THA cases with the use of spacers. In spacers with semi-constrained articulation, there is the possibility of partial reduction of the spacer.Conclusions: Dislocation is one of the most common mechanical complications after primary and revision THA. In the majority of the cases, acute closed reduction can be achieved successfully in the ED setting. However, there are specific dislocation types that present unique challenges to acute reduction. [ABSTRACT FROM AUTHOR]

Radiation therapy for intracranial lesions is constrained by dose to neurologic organs at risk. We report 2 cases, a newly diagnosed chondrosarcoma and a previously irradiated meningioma, with tumors that abutted the optic chiasm following subtotal resection. Definitive radiotherapy would have required either undercoverage of the tumor or treatment of the chiasm with doses posing an unacceptable risk of blindness. Therefore, the patients underwent open surgery with placement of an abdominal fat autograft to provide space between the tumor and the optic structures at risk. Patients received definitive fractionated stereotactic radiotherapy. For each patient, we retrospectively compared the treated plan (with fat autograft) to a second plan generated using the pre-autograft imaging, maintaining similar tumor coverage. For the chondrosarcoma, the fat autograft reduced the optic chiasm maximum dose by 21% (70.4 Gy to 55.3 Gy). For the reirradiated peri-optic meningioma, the optic chiasm maximum dose was reduced by 10% (50.8 Gy to 45.9 Gy), the left optic nerve by 17% (48.9 Gy to 40.4 Gy), and the right optic nerve by 30% (32.3 Gy to 22.6 Gy). We demonstrate the utility of abdominal fat autograft placement to maximize coverage of tumor while minimizing dose to intracranial organs at risk. [ABSTRACT FROM AUTHOR]

Background: In difficult-to-treat cases, it is necessary to add debridement steps in prosthesis-free interval of 2-stage exchange. We aimed to analyze the functional and clinical outcome of patients treated with a multistage exchange of total hip arthroplasty without the use of spacers, rather only cementless implants.Methods: Between 2009 and 2018, 84 patients (mean age: 67.3 [39-90] years) suffering chronic late-onset periprosthetic joint infection (PJI) were treated using a multistage prosthesis exchange without spacers. The mean follow-up was 70 ± 45.3 [14-210] months. The treatment included prosthesis exchange and at least 1 additional revision step before a reimplantation, owing to ongoing acute infection in the prosthesis-free interval. High-efficiency antimicrobial therapy was administered in between, which was discontinued after cementless revision implantation.Results: The mean number of revisions between explantation and implantation was 2.6 (1-9). The most common microorganism was Staphylococcus epidermidis (53.6%) followed by Staphylococcus aureus (16.7%) and Cutibacterium acnes (11.9%). The bacterial load was more than one bacterium per patient in 38% of cases. All patients could be treated using a cementless implant. PJI remission was achieved in 92% of cases. Overall, 9 prostheses (11%) were replaced because of an ongoing PJI or fracture. The mean modified Harrison Hip Score was 63.4 (22-88) points. No patient died.Conclusion: Multistage total hip arthroplasty exchange showed high remission rates and low mortality in difficult-to-treat cases. Spacer-free and multistage treatment had no negative effect on the success rate or functional outcome, consistent with the results of published 2-stage exchange studies. Implantation of an uncemented press-fit prosthesis was possible in all patients with no elevated periprosthetic fracture rate. [ABSTRACT FROM AUTHOR]

Background: The purpose of this study was to compare patients who had chronic prosthetic joint infection treated using three methods of articulating polymethylmethacrylate spacers in two-stage reimplantation.Methods: We identified 77 patients who had chronic prosthetic joint infection with a minimum of one-year follow-up. Reinfection rates were determined using modified International Consensus group criteria.Results: The overall reinfection rate was 18% (14 of 77 patients). Despite a higher medical comorbidity in the second-generation spacer cohort, there were no statistical differences in reinfection rates between articulating spacer types.Conclusion: This study suggests that there were no differences in efficacy between the traditional molded, first-generation premolded, and second-generation premolded articulating spacers, but more studies with high level of evidence are needed. [ABSTRACT FROM AUTHOR]

An articulating or nonarticulating antibiotic hip spacer can be placed following the first stage implant removal of a periprosthetic hip joint infection. Antibiotic spacers help fill in the dead space created at the time of resection and provide a high local concentration of antibiotics. Theoretical advantages of a static spacer include a higher elution of antibiotics because of the increased surface area, the ability to protect deficient bone in the proximal femur/acetabulum, and the ability to immobilize the periarticular soft tissues. Advantages of an articulating spacer include improved ambulation and easier motion for the patient, maintenance of soft tissue tension, and an easier surgical reconstruction at the time of the second stage. Additionally, an articulating antibiotic spacer may minimize the risk of dislocation following the second stage reconstruction. The choice of articulating or nonarticulating is currently one of surgeon preference yet it is advised that surgeons consider an articulating spacer for all patients except those with severe femoral/acetabular bone loss or deficient abductors. [ABSTRACT FROM AUTHOR]

Antibiotic-loaded bone cement (ALBC) spacer constructs for the treatment of periprosthetic joint infections of the knee continue to evolve from the original hockey puck designs. Countless techniques have since been described for augmentation of ALBC spacers with the use of intramedullary (IM) dowels. The use of IM dowels has become a vital addition to any knee spacer construct. ALBC IM dowels are an excellent vessel to provide targeted local antibiotic treatment to high-risk areas like the medullary canal while increasing the overall therapeutic antibiotic elution. In addition, IM dowels provide needed stabilization to the relatively unstable intra-articular spacer component, thereby reducing spacer-related complications like displacement and fracture. Therefore, we recommend regular use of IM dowel augmentation to ALBC spacer constructs. [ABSTRACT FROM AUTHOR]

Schematic diagram of "Ludwigia sedioides" inspired substance-exchangeable spacer PTMS@P with PRP incorporated and its therapeutic effects for skin flap repair. [Display omitted] • A "Ludwigia sedioides" inspired ultra-thin microporous spacer is developed. • Slow-released growth factors from PRP strengthen revascularization and ECM synthesis. The spacer facilitates vascular shuttling and substance exchange. Extended vascular networks promoted skin flap survival and regeneration. Adequate substance exchange is an important prerequisite for tissue repair, and how to efficiently establish mature vascular networks to enhance the graft-host substance exchange is a challenge. Herein, inspired by the special structure of the aquatic plant "Ludwigia sedioides", ultra-thin microporous scaffolds (TMS) of bovine Achilles tendon derived collagen were fabricated as "floating leaves" via pyridine reaction, and cleverly combined with platelet-rich plasma (PRP) after the Schiff base and Michael additions reactions of polydopamine to construct a biomimetic "Ludwigia sedioides" spacer (PTMS@P), allowing blood vessels (as a "rhizome") freely shuttling and substance exchange. In this spacer, growth factors were efficiently released to peak concentrations in the first 12 h, thereby facilitating rapid blood vessel growth. In the subsequent 96 h, these slow-released growth factors retained at 11.6 % to 45.8 % of the peak concentrations, sustainedly promoting vascular networks shuttling through the spacer, graft-host substance exchange and extracellular matrix synthesis in fibroblasts. In vitro, the spacer significantly fostered fibroblasts and endothelial cells' proliferation, adhesion and migration, which were fundamental for revascularization and substance exchange. Immunohistochemical staining of CD31 and Ki67 in vivo demonstrated that abundant vascular networks shuttled through PTMS@P and extended from flap base to the farther flap body, promoting more robust substance exchange and cellular metabolism, which significantly enhanced the survival of ischemic flaps in nude mice. Altogether, this "Ludwigia sedioides" inspired spacer PTMS@P with strengthened revascularization and substance-exchange functionality holds promising applications for tissue repair and regeneration. [ABSTRACT FROM AUTHOR]

Cable wake-induced vibrations (CWIV) and tower column wake-induced vibrations (TWIV) are two types of detrimental vibrations for long hanger cables in suspension bridges. In this study, the hybrid control strategy that combines spacers with dampers is proposed as a potentially effective method for mitigating these vibrations. To validate this hypothesis, the control performance of spacers combined with dampers for both CWIV and TWIV is evaluated through aero-elastic wind tunnel tests. The universal characteristic equation of the hanger cable-spacers-damper system is derived. On this basis, modal behaviors of hanger cables with spacers and dampers are investigated to demonstrate the control principle of the hybrid strategy. The three-dimensional aero-elastic models of hanger cables, spacers, and the eddy current damper are designed and manufactured to evaluate the combined control performance of spacers and dampers for CWIV and TWIV by a series of wind tunnel tests. In addition, the effect of modal damping ratios on the control performance of TWIV is investigated by an oil damper installed at a high location on hanger cables. The results showed that spacers combined with dampers are more effective than spacers alone in mitigating CWIV and TWIV. The hybrid control strategy can suppress the vibration response of CWIV to an acceptable level, but a larger modal damping ratio in the first global mode (approximately 3%) is required to mitigate TWIV. ● Derive the universal characteristic equation of the hanger-spacers-damper system. ● Illustrate combined control principle of spacers and dampers for hanger vibration. ● Evaluate the combined control performance for CWIV and TWIV by aeroelastic test. ● Required modal damping ratios of hanger cables for suppressing TWIV are determined. [ABSTRACT FROM AUTHOR]

Here, in this study we report the synthesis and characterizations of novel electrolyte based on dicationic salts 1,3-bis(1-alkyl-1,2,4-triazolium)mesitylene bis(tetrafluoroborate). Two cations were linked by mesitylene as spacer. Using 1H NMR, 13C NMR, FTIR and RAMAN spectroscopy methods the structural characterization of synthesized salts were done. Cyclic voltammetry, electrochemical impedance spectroscopy, thermogravimetry analysis, and differential scanning calorimetry have all been used to examine their thermal, electrochemical, and transport properties. Their suitability for energy storage was examined by fabricating a cell out of it in a Swagelok, where ionic liquid gel polymer electrolyte (ILGPE) was used as electrolyte and the graphite-PTFE sheet functioned as an electrode to construct a symmetrical EDLC. A wide working electrochemical potential window range of 0 to 4.5 V was obtained after studying the electrochemical cell performance, indicating that the dicationic salts can be employed as a promising electrolyte. It provided an effective areal capacitance of 63.13 F/cm2. Even after 2000 consecutive cycles of charging and discharging, the fabricated device continues to retain about 80 % of its initial capacitance. The GCD curves provided computed values for energy and power density of 1.1 μWh and 317.5 μW/cm2, respectively. [Display omitted] [ABSTRACT FROM AUTHOR]

• Using RSM and CFD, operational parameters of spacer-filled channel are optimized. • Pressure drop, water flux and SCE are representing output operational parameters. • System sensitivity from inlet velocity, mesh, and attack angles is investigated. • Velocity variation along the flow and its effect on optimal conditions is discussed. • Inlet velocity has the greatest impact on the output parameters in design space. Using the response surface methodology (RSM) coupled with computational fluid dynamics, the hydrodynamic and mass transfer have been investigated in a spacer-filled channel. Geometry of an industrial reverse osmosis spiral-wound membrane module has been set to optimize the pressure drop, water permeation flux and the spacer configuration efficacy with respect to the average inlet velocity, the spacer attack angle and the spacer mesh angle. Several tools have been used to implement the response surface methodology: The Latin Hypercube Sampling Design method for design points generation, the Kriging model for interpolation and regression, and the genetic algorithm for optimization. It was found that the optimum configuration taking all the output operational parameters into account was stood up at the attack angle of 75°, the mesh angle of 85.9°, and the average inlet velocity of 0.0428 m/s. Also the global sensitivity analysis has been performed, which the average inlet velocity and the attack angle were obtained the most and the least effective parameters on optimum conditions, respectively. Due to the change in the velocity along the RO module with several SWM elements, the optimum performance was achieved by adjusting the geometric structure of the spacers with velocity variations in each RO element. [ABSTRACT FROM AUTHOR]

In the present work, a comprehensive study of temperature on gate-all-around silicon nanowire FETs (GAA-SNWTs) with source/drain underlap is performed to investigate the influence of Air as spacer dielectric, on analog/RF behavior of the device. The transconductance g m of the device enhances when the temperature is dropped down to 100 K. Thus, the analog/RF figure-of-merit (FOM) of the device enhances, rendering the device suitable for low temperature, low-power high-frequency operations. For targeting low power applications, FOMs are elicited at 10 μA/μm. It is perceived that the intrinsic gain of the device is marginally altered for distinct spacer dielectric (Si 3 N 4 and air). Frequencies like cut-off frequency (f T) and maximum oscillation frequency (f MAX) of air spacer dielectric based underlap GAA-SNWTs are enhanced by 2.15 times and 1.73 times respectively when the operating temperature is dropped down to 100 K from 400 K. This results in higher percentage improvement in RF-FOM in terms of transconductance frequency product (TFP), gain-frequency product (GFP), and gain transconductance frequency product (GTFP). [ABSTRACT FROM AUTHOR]

Highlights • A method for modeling the flexible bundled conductors was established. • The CBCM was modified for loading force on the intermediate of the conductor. • The bending stiffness of the conductor was considered in the model. Abstract To evaluate the terminal force and configuration of bundled flexible conductors used in high voltage substations, this study developed a parametric method for modelling the large planar deflection of the flexible conductors. The flexible conductors were assumed to be planar beams. Based on the chained-beam constraint model (CBCM), the equations of the constraint effects of spacers and the geometric constraint of the bundled conductors were added to the model. Additionally, the CBCM was modified to capture the loading of a concentrated force on the intermediate part of the conductors. The model was validated by static tests and finite element analyses. Some case studies on the terminal force and configuration of the bundled flexible conductors based on this model were carried out. The terminal force and configuration of the bundled conductors calculated with and without bending stiffness were compared, showing that the constraint effects of the spacers increased the stiffness of the bundled conductors. Ignoring the bending stiffness and the constraint effects of the spacers will lead to analytical errors in the terminal force and configurations of the bundled flexible conductors used in high voltage substations. [ABSTRACT FROM AUTHOR]

Highlights • We used a newly developed, high-porosity unidirectional porous hydroxyapatite spacer for double-door laminoplasty. • Regenos spacers lowered the risk of dislocation after implantation and facilitated bone bonding. • Breakage and deformity of Regenos spacers was observed at high rates because of their insufficient mechanical strength. Abstract We used a newly developed, high-porosity unidirectional porous hydroxyapatite spacer (Regenos spacer, not approved by the FDA). To assess the short-term bone bonding capacity of Regenos spacer used in a double-door laminoplasty, including displacement, deformation, and absorption after implantation. Fifty patients underwent a double-door laminoplasty using Regenos spacers, with computed tomography (CT) images obtained at 2–4 weeks and 6–12 months, post-surgery, in 30 patients. Bone bonding rate, amount of displacement, and the incidence of deformation and absorption were evaluated from the early and late postoperative CT images. Bone bonding rate for Regenos spacers, using our modified classification, was 48.9% at 6 months, post- surgery, and 67.0% at 12 months. The change in anterior-posterior diameter of the spinal canal (ΔH) was significantly greater for Regenos spacers than for autologous bone spacers (p < 0.05). There was no difference in the change in angle between the vertebral arch and the posterior wall of the vertebral body (ΔR) between the Regenos and autologous bone spacers. Deformation was identified in 21.3% (10/47). Though, no evidence of breakage along their long axis was identified among these 10 cases on axial CT images with passable clinical results. Regenos spacers lowered the risk of early dislocation after implantation and facilitated bone bonding due to infiltration of surrounding tissue. However, the deformation and absorption was observed at high rates because of their insufficient mechanical strength, we need to require a longer term follow-up to more clearly evaluate their adverse impact in clinically. [ABSTRACT FROM AUTHOR]

Abstract Purpose Accelerated partial breast irradiation is a treatment option for selected patients with early-stage breast cancer. Some accelerated partial breast irradiation techniques lead to skin toxicity with the skin dose as a main risk factor. Biodegradable spacers are effective and safe in prostate brachytherapy to protect the rectum. We hypothesize that a subcutaneous spacer injection reduces the skin dose in breast brachytherapy. Methods and Materials Ultrasound-guided spacer injections, either hyaluronic acid (HA) or iodined polyethylene glycol (PEG), were performed on fresh mastectomy specimens. Success was defined as a spacer thickness of ≥5 mm in the high-dose skin area. Usability was scored using the system usability scale. Pre and postinjection CT scans were used to generate low-dose-rate seed brachytherapy treatment plans after defining a clinical target volume. Maximum dose to small skin volumes (D 0.2cc) and existence of hotspots (isodose ≥90% on 1 cm2 of skin) were calculated as skin toxicity indicators. Results We collected 22 mastectomy specimens; half had HA and half had PEG injection. Intervention success was 100% for HA and 90.9% for PEG (p = NS). Hydrodissection was feasible in 81.8% with HA and 63.6% with PEG. Median system usability scale score was 97.5 for HA and 82.5 for PEG (p < 0.001). Mean D 0.2cc was 80.8 Gy without spacer and 53.7 Gy with spacer (p < 0.001). Skin hotspots were present in 40.9% without spacer but none with spacer (p < 0.001). Conclusions A spacer injection in mastectomy specimens is feasible. An extra 5 mm space is always achieved, thereby potentially reducing the skin dose dramatically in low-dose-rate seed breast brachytherapy. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Heparin was immobilized successfully on Ps microspheres with L-phenylalanine as a ligand for endotoxin adsorption. • Heparin as a molecular spacer of adsorbents surface improved the hydrophilicity and blood compatibility of microspheres. • L-phenylalanine grafted on adsorbents played a synergistic role with heparin in improving anticoagulation of adsorbents. • The adsorption capacity of endotoxin for Ps-Hep-Phe was increased compared with the nascent microspheres. Abstract Heparin, a highly sulfated linear polysaccharide, with anticoagulation function and blood compatibility is widely used as a biomaterials in medical application, but the most importance of heparin is its structure function as the macromolecular space arm. In this study, heparin as a spacer was covalently immobilized on the chloromethylated polystyrene microspheres (Ps) and then connected with l -phenylalanine forming the Ps- Hep -Phe structure, which was developed for endotoxin adsorption in hemoperfusion. The grafting density of heparin reach the maximum when the initial concentration of heparin solution was 5 mg/mL. The adsorbents with the heparin as a spacer showed the prolonged clotting times, low protein adsorption, and reduced the hemolysis rate, indicating that heparin-modified adsorbents have great blood compatibility. The adsorption capacity of Ps-Hep-Phe for endotoxin was 25.15 EU/g in dynamic adsorption, higher than that of Ps. Therefore, this study imply that heparin would be promising for modification of adsorbents in hemoperfusion. [ABSTRACT FROM AUTHOR]

Abstract An ultrasensitive sandwich-type electrochemical immunosensor was designed by using gold nanoparticles (Au NPs) as the substrate material and microporous carbon spheres (CS) loading silver nanoparticles (Ag NPs) spaced Hemin/reduced graphene oxide (Hemin/rGO) porous composite materials (Ag NPs@CS-Hemin/rGO) as the detection antibodies (Ab 2) label for detecting carcinoembryonic antigen (CEA). The Au NPs with good electrical conductivity and biocompatibility could accelerate the electron transfer on the electrode interface and enhance the load capacity of capture antibodies (Ab 1). Hemin is peroxidase-like substance which has excellent catalytic ability for H 2 O 2 reduction but easy to molecular aggregation and oxidative self-destruction. Reduced graphene oxide (rGO) is a good supporting material for Hemin to mitigate this disadvantage. CS loading Ag NPs (Ag NPs@CS) as the spacer inserts into Hemin/rGO sheet can overcome the irreversible stacking of rGO, and form complex porous structure which exposes more active sites of Hemin. Moreover, Ag NPs loaded on CS also has catalytic ability for H 2 O 2 reduction. Thus the Ag NPs@CS-Hemin/rGO used as the Ab 2 label has a large working surface area and high utilization rate, which heightens the catalytic ability for H 2 O 2 reduction to amplify the current signal effectually. The current signal and the logarithm of CEA concentration presented a wide linear response range of 20 fg/mL to 200 ng/mL, and the detection limit of CEA was 6.7 fg/mL. Furthermore, the designed immunosensor exhibited a good reproducibility, selectivity and stability, which confirms a broad development prospect when applying it in early clinical detection. Highlights • The immunosensor exhibits a broad detection range and low detection limit for CEA. • The Ag NPs@CS-Hemin/rGO was first applied as an Ab 2 label to amplify current signal. • Use Ag NPs@CS as the spacer inserted into Hemin/rGO to form porous structure. • The immunosensor shows a good prospect in early clinical detection. [ABSTRACT FROM AUTHOR]

Abstract Background In a two-stage exchange protocol for prosthetic joint infection (PJI), bacteria surviving over the antibiotic-loaded cement spacers may cause the persistence of infection with renewed clinical symptoms following the surgery. Culture after sonication of removed prosthesis is more sensitive than conventional periprosthetic tissue culture for the microbiological diagnosis of PJI. The aim of this study was to assess whether sonication of the spacer at the time of the second-stage procedure may improve the diagnosis of persistent PJI. Methods We evaluated by microbiological culture the sonication fluid from 222 cement spacers implanted in a two-stage exchange protocol in 157 patients affected by PJI. A mean of 1.3 (range, 1–4) spacer per patient was performed. Results In 53 out of 222 spacers analyzed infection was confirmed according to the MSIS criteria. In 22 cases the infection was confirmed by both cultures on periprosthetic tissue and on sonication fluid from the spacers. In 23 cases persistent PJI was identified because of only cultures of periprosthetic tissue and 8 because of results obtained after spacer sonication. The sensitivity of periprosthetic tissue cultures was higher than that of cultures performed on sonication fluid (84.9% vs 56.6%, p <.001). Conclusions Even though sonication of cement spacers has performances inferior than those reported for prosthesis, it can be considered a complementary method to unravel persistent infection during a two-stage exchange protocol for PJI. Highlights • Sonication of cement spacers has performances inferior than for prosthesis. • It is a complementary method to unravel persistent infection. • More relapsing PJI were observed in patients with multiple spacer exchange. [ABSTRACT FROM AUTHOR]

Highlights • By substituting metal instead of graphite, the size of a PEMFC is reduced to 1/4. • The required Reynolds number for cooling is reduced 50% by using 5 vol% nanofluid. • At high Reynolds numbers, nanofluids’ concentration is not an effective factor. Abstract Polymer electrolyte membrane fuel cells (PEMFC) can be a promising energy source if optimal thermal management is provided, and also manufacturing cost is reduced for mass production. These are the main goals researchers have been recently pursuing to commercialize the PEMFCs. Here, a new simulation based design is proposed for a PEMFC with metallic bipolar plates. Using metal plates facilitates the manufacturing process and provides the possibility of forming them into desired shapes. Metallic bipolar plates are considered for both the reacting and cooling sites by pressing them into desired forms. Here, three different spacer plates as models A, B and C are designed to let fluid pass through the extruded site. The bipolar plate surface-averaged temperature is the parameter for evaluating the performance of the spacers in cooling strategy. Model C showing the best performance with least surface-averaged temperature among others, it was considered for further investigations. Moreover, spacer C is improved by punching some holes in critical regions to allow the fluid flow more easily in order to attain a uniform temperature distribution in lower Reynolds number. Using water based nanofluid with a concentration 5 vol%, the desired cooling performance is achieved at Reynolds number 500, which is reduced to a half if compared with the base fluid. Also, the innovative cooling design employed in our study is believed to exquisitely contract the size of a PEMFC and hence successfully reduce its weight. [ABSTRACT FROM AUTHOR]

This study provides a comprehensive and systematic overview of the fundamental characteristics of heat and mass transfer in the direct contact membrane distillation (DCMD) process that employs different types of spacers on one or both surfaces of the membrane. Detailed theoretical investigations were carried out to demonstrate the effects of spacers adjacent to the membrane surface on heat and mass transfer enhancement in the DCMD with a PTFE/PP composite membrane, complemented with experimental data for model validation. Thus, this work aimed to propose and demonstrate the heat transfer correlation for spacer-filled channels to reliably predict the heat and mass transfer improvement by non-woven net spacers in the DCMD process. The results showed that the permeate flux enhancement by the spacers ranged between 7% and 19% only for the spacer-filled permeate channels and between 21% and 33% only for the spacer-filled feed channels even at higher flow rates, thus indicating lower flux enhancements in the spacer-filled permeate channels. This was because the influence of spacers on flux improvement became more evident at higher temperatures owing to higher temperature polarization. In this study, the maximum flux enhancement of approximately 43% over the empty channels was achieved using the thinnest and densest spacer with a hydrodynamic angle of 90°, adjacent to both membrane surfaces. [ABSTRACT FROM AUTHOR]

Experimental and numerical investigations on spacer-induced heat transfer deterioration of supercritical water in annular channel have been carried out. The test section consists of a heated outer rod of 15.0 mm inner diameter and a concentric unheated inner rod of 7.41 mm outer diameter, forming a 3.80-mm-wide annular channel. A spacer with block ratio of 0.3 is equipped into the channel. The experimental conditions are the pressure of 23–25 MPa, mass flux of 450–1200 kg/(m 2 s), heat flux of 400–1000 kW/m 2 and fluid temperature of 240–450 °C. The spacer-induced heat transfer deterioration occurs at the conditions of mass flux 450 kg/(m 2  s), heat flux 400 kW/m 2 and specific fluid temperature region. Based on the experimental data, the criteria for the occurrence of deterioration are obtained. For the case that heat transfer deteriorates, the wall temperature experiences a couple of oscillations before recovering to the fully developed state. In order to study the mechanism of this complicated heat transfer behavior, numerical simulation has been performed with FLUENT and a reasonable explanation has been proposed. [ABSTRACT FROM AUTHOR]

Graphical abstract With an alky thiophene and a bare thiophene as spacer, PBTTF-H exhibits high photovoltaic properties in the non-halogenated processed devices. Highlights • Three new BDF-FBT based polymers with different spacer were investigated. • With an alky thiophone and a bare thiophone as the spacer, PBTTF-H performs best. • A hexyl side chain leads a PCE gap of 5% between PBTTF-C 6 and PBTTF-H based cells. Abstract In this work, we demonstrate the chemical optimization of benzo[1,2-b:4,5-b′]dithiophene (BDT)-5,6-difluorobenzo-[2,1,3]thiadiazole (FBT) D-A alternating copolymer for obtaining the efficient polymeric donors for the environment-friendly solution processed polymer solar cells (PSCs). Three polymers PBTF, PBTTF-C 6 and PBTTF-H, in which one or two alky thiophene units are inserted into the backbone of BDT-FBT alternating copolymer, present much different performances either in the PSCs processed from halogenated solvent and additive or in the PSCs processed from non-halogenated solvent and additive. With an alky thiophene and a bare thiophene as the spacer, PBTTF-H performs best among the three. Especially when the devices processed from 1,2,4-trimethylbenzene and diphenyl ether, in which the highest PCE of 6.80% is achieved with a V OC of 0.77 V, a J SC of 13.67 mA cm−2 and a FF of 64.2%. We think these results will cast light on developing new polymeric donors of the green-solvent-processed PSCs. [ABSTRACT FROM AUTHOR]

Highlights • We used a newly developed, high-porosity unidirectional porous hydroxyapatite spacer with expectation of high bone conductive potential and biomechanical strength, both of which are essential for a lamina spacer for open-door type laminoplasty. • The aim of the present study was to elucidate the effectiveness of Regenos laminar spacers for open-door type laminoplasty. • Regenos spacers are not suitable for open-door laminoplasty because of adverse events. Abstract We used a newly developed, high-porosity unidirectional porous hydroxyapatite spacer (Regenos spacer, not approved by the FDA). The aim of the present study was to elucidate the effectiveness of Regenos laminar spacers for open-door type laminoplasty. The present study included 39 patients who underwent open-door type laminoplasty with Regenos spacers from April 2015 to December 2016 and were followed up for at least 6 months after surgery. We grafted 68 Regenos spacers in 39 patients. Pre- and postoperative neurological status of patients were evaluated using JOA score and recovery rate. Breakage of Regenos spacers, laminar closure, and bone-hydroxyapatite spacer bonding were assessed using 12-month postoperative sagittal and axial CT images. The average preoperative JOA score was 9.5 ± 3.2/17, and the average postoperative JOA score was 12.5 ± 2.9/17. JOA score recovery rate was 34 ± 41% at the latest follow-up visit. The bony fusion rate of the hinge sides was 87%. Breakage and deformity of implanted spacers was observed in 69% of patients and 59% of spacers with a CT sagittal view, and CT axial view at 12 months revealed fine cracks and collapse in 17 spacers in 14 patients. The average angle was −2.4 ± 4.8°, including 46 of 68 spacers showing a negative value, resulting in a rate of laminar reclosure of 35%. Postoperative CT demonstrated good bone bonding rate. Nevertheless, clinical results with low recovery rates were obtained with complications related to the use of Regenos spacers. [ABSTRACT FROM AUTHOR]

Butyl group and unsaturated groups (2-butenyl, 2-butynyl and dimethylphenyl) have been introduced as spacers of Gemini surfactants for modifying vermiculite (VT) to exploit easily industrialized adsorbents and to explore systematically the effects of spacers on the adsorption of p -nitrophenol (PNP). Four organo-vermiculites (OVTs including 12-A-12-VT (alkyl), 12-P-12-VT (dimethylphenyl), 12-E-12-VT (2-butenyl), 12-Y-12-VT (2-butynyl)) have been prepared successfully and characterized by FT-IR, XRD, TG, SEM, BET, elemental analysis and Zeta potential. The results show that the four have low saturated adding amount of surfactant (0.4 CEC), and 12-A-12 with flexible alkyl group shows markedly higher loading amount (18.8 wt%) on VT than the three surfactants with rigid unsaturated spacer (16.7 wt%, 15.7 wt% and 15.4 wt%). The batch experiment results of OVTs to PNP demonstrate that the four are ranked by adsorption capacity as follow: 12-A-12-VT > 12-P-12-VT > 12-E-12-VT    ≈  12-Y-12-VT, their maximum adsorption all occur at pH = 6 within 20 min and 12-A-12-VT possess stronger removal capacity ( q max  = 106.5 mg/g) than other clay-based adsorbents. Furthermore, Kinetic studies are found pseudo-second-order ( R 2  > 0.999) and equilibrium data are fitted well by Freundlich isotherm model ( R 2  > 0.98). The calculated thermodynamic parameters exhibit that the adsorption processes of PNP on OVTs are physical and exothermic. [ABSTRACT FROM AUTHOR]

Gemini cationic surfactant with tetrasiloxane-tailed has potential to improve performance and biocompatibility in a range of applications. With different rigidity spacers, structure effects on their self-assembling behavior and interface properties are obvious. Hence, it should be possible to tune system surface properties and aggregation morphology in aqueous solution by changing rigidity of spacers. A series of novel cationic tetrasiloxane Gemini surfactants MR8M, MDM, MDOM were designed and synthesized by a simple process. Their surface property, hydrolysis resistance ability, wetting ability, aggregation behavior as well as antibacterial activity in aqueous solutions were studied. These three surfactants exhibited high hydrolysis resistance in both acidic and neutral aqueous solutions. On one hand, surface tension of MR8M (γ CMC  = 19 mN/m) and MDOM (γ CMC  = 23 mN/m), significantly lower than C 8 -PSi-C 8 (γ CMC  = 37 mN/m) with siloxane spacer and pure hydrocarbon equivalents. On the other hand, MR8M can wet the highly hydrophobic PTEF plate completely at low concentration (0.4 mM). In addition, different aggregations, MDM with only vesicle, MDOM with spherical micelle and vesicle micelle and MR8M spherical micelle, wormlike micelle and vesicle were observed to assemble. Moreover, the antibacterial activity of these surfactants increased as the rigidity of spacer increased and MDM exhibited best antibacterial activity. [ABSTRACT FROM AUTHOR]

High-performance pressure sensors attract widespread attention due to the potential applications in human-machine interaction and wearable electronics. However, most of flexible pressure sensors need elaborate nanostructure design, and thus their manufacture is consuming and complicated. Therefore, a large-scale and low-cost technology is highly desirable to fabricate flexible pressure sensitive materials with high sensitivity in broad pressure range. Here, an MXene-sponge was fabricated by a simple and efficient dipping-coating process method and was applied in the piezoresistive sensor with insulating Polyvinyl Alcohol (PVA) nanowires as a spacer. The sensor based on MXene-sponge presents high sensitivity for a broad pressure range (147 kPa −1 for less than 5.37 kPa region and 442 kPa −1 for 5.37–18.56 kPa region), a low detection limit of 9 Pa, a rapid response time of 138 ms, and an excellent durability over 10,000 cycles. Human physiological signal (such as respiration, joint movement and pulses) can be real-time monitored by the MXene-sponge sensor. The potential applications of the sensor in measuring pressure distribution and human-machine interaction are also explored. [ABSTRACT FROM AUTHOR]