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Water-stable macroporous hydrogels, inspired by the structural and chemical characteristics of plant stems, are expected to open a wide range of possibilities in soft materials for passive liquid transport. However, obtaining efficient materials for these applications still poses a major challenge due to the complexity of shaping hydrogels at the relevant scale-length. Here, water-stable macroporous hydrogels were fabricated using alginate and TEMPO-oxidized cellulose via a new approach involving ice templating and topotactic ion-crosslinking with Ca 2+ . This approach fully avoids the energy-intensive lyophilization process and results in composite hydrogels with pore sizes akin to those found in celery xylem, a model we chose for plant stems. Importantly, the pore size could be tailored by adjusting both the ice-growth velocities and the ratios of alginate to oxidized cellulose. The resulting hydrogels displayed remarkable water stability along with viscoelastic properties and wettability that depend on the alginate and oxidized cellulose ratios. Mechanical properties, such as compression stress and toughness, consistently increased with higher alginate contents. In addition, liquid transport measurements on crosslinked hydrogels with varying compositions and ice growth velocities revealed rising speeds comparable to those observed in celery, confirming the ability of polysaccharide-based hydrogels obtained by ice templating and topotactic crosslinking as relevant materials to mimic the function of plant stems. Due to their intrinsic biocompatibility, the materials presented here offer significant potential for developing soft liquid transport systems suited for biological settings, with promising applications in both environmental and bioengineering fields.

Repairing tubular tissues-the trachea, the esophagus, urinary and gastrointestinal tracts, and the circulatory system-from trauma or severe pathologies that require resection, calls for new, more effective graft materials. Currently, the relatively narrow family of materials available for these applications relies on synthetic polymers that fail to reproduce the biological and physical cues found in native tissues. Mimicking the structure and the composition of native tubular tissues to elaborate functional grafts is expected to outperform the materials currently in use, but remains one of the most challenging goals in the field of biomaterials. Despite their apparent diversity, tubular tissues share extensive compositional and structural features. Here, we assess the current state of the art through a dual layer model, reducing each tissue to an inner epithelial layer and an outer muscular layer. Based on this model, we examine the current strategies developed to mimic each layer and we underline how each fabrication method stands in providing a biomimetic material for future clinical translation. The analysis provided here, addressed to materials chemists, biomaterials engineers and clinical staff alike, sets new guidelines to foster the elaboration of new biomimetic materials for effective tubular tissue repair.

This paper focuses on the modeling, control, and simulation of an over-actuated hexacopter tilt-rotor (HTR). This configuration implies that two of the six actuators are independently tilted using servomotors, which provide high maneuverability and reliability. This approach is predicted to maintain zero pitch throughout the trajectory and is expected to improve the aircraft's steering accuracy. This arrangement is particularly beneficial for precision agriculture (PA) applications where accurate monitoring and management of crops are critical. The enhanced maneuverability allows for precise navigation in complex vineyard environments, enabling the unmanned aerial vehicle (UAV) to perform tasks such as aerial imaging and crop health monitoring. The employed control architecture consists of cascaded proportional (P)-proportional, integral and derivative (PID) controllers using the successive loop closure (SLC) method on the five controlled degrees of freedom (DoFs). Simulated results using Gazebo demonstrate that the HTR achieves stability and maneuverability throughout the flight path, significantly improving precision agriculture practices. Furthermore, a comparison of the HTR with a traditional hexacopter validates the proposed approach.

Introduction: This study aimed to compare a new multicolored rotary system with four heat-treated rotary instruments using the multimethod approach., Methods: Three-hundred instruments of RCS Rainbow, Rotate, RaCe EVO, OneCurve, and ProTaper Ultimate systems were evaluated regarding their design (stereomicroscopy, scanning electron microscopy, and 3D surface scanning), metallurgy, and mechanical performance (cyclic fatigue, torsional resistance, bending and buckling resistance, and cutting ability). Unprepared surfaces after canal preparation of maxillary molars were evaluated using micro-computed tomography. Kruskal-Wallis and one-way analysis of variance post hoc Tukey tests were used for statistical comparisons (α = 5%)., Results: Instruments exhibited variations in active blade length, number of spirals, and cross-sectional designs. RCS Rainbow showed specific phase transformation temperatures, highest bending (400.5gf) and buckling (286gf) resistance values, and lowest mean angle of rotation (529°) (P < .05). OneCurve exhibited superior cutting ability (8.4 mm) and longer time to fracture (112s). RaCe EVO displayed the lowest time to fracture (51s), maximum torque (1.2 N.cm), buckling (174gf), and bending resistance (261gf) values (P < .05). ProTaper Ultimate showed the highest torque (1.6 N.cm) and angle of rotation (611°) (P < .05), while its bending load (262gf) was comparable to RaCe EVO (P > .05). Rotate instrument showed intermediate values in the mechanical tests. No difference was observed regarding the unprepared canal surfaces (P > .05) CONCLUSIONS: RCS Rainbow demonstrates a trade-off between flexibility and other mechanical properties. Its dimensions exceeded those of other instruments, affording it higher torque resistance, yet concurrently reducing its flexibility, angle of rotation, and cutting ability. OneCurve stands out as a well-balanced choice by integrating geometric design and mechanical performance., (Copyright © 2024 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Synthetic tubular grafts currently used in clinical context fail frequently, and the expectations that biomimetic materials could tackle these limitations are high. However, developing tubular materials presenting structural, compositional and functional properties close to those of native tissues remains an unmet challenge. Here we describe a combination of ice templating and topotactic fibrillogenesis of type I collagen, the main component of tissues' extracellular matrix, yielding highly concentrated yet porous tubular collagen materials with controlled hierarchical architecture at multiple length scales, the hallmark of native tissues' organization. By modulating the thermal conductivity of the cylindrical molds, we tune the macroscopic porosity defined by ice. Coupling the aforementioned porosity patterns with two different fibrillogenesis routes results in a new family of tubular materials whose textural features and the supramolecular arrangement of type I collagen are achieved. The resulting materials present hierarchical elastic properties and are successfully colonized by human endothelial cells and alveolar epithelial cells on the luminal side, and by human mesenchymal stem cells on the external side. The proposed straightforward protocol is likely to be adapted for larger graft sizes that address ever-growing clinical needs, such as peripheral arterial disease or tracheal and bronchial reconstructions.

Ceratocystis fimbriata is a destructive fungal pathogen of sweetpotato ( Ipomoea batatas ) that leads to losses at all stages of sweetpotato production. Accurate detection of C. fimbriata would allow for more efficient deployment of management tactics in sweetpotato production. To develop a diagnostic assay, a hybrid genome assembly of C. fimbriata isolate AS236 was generated. The resulting 31.7-MB assembly was near-chromosome level, with 18 contigs, 6,481 predicted genes, and a BUSCO completion score of 98.4% when compared with the fungus-specific lineage database. Additional Illumina DNA reads from C. manginecans, C. platani , and a second C. fimbriata isolate (C1421) were then mapped to the assembled genome using BOWTIE2 and counted using HTSeq, which identified 148 genes present only within C. fimbriata as molecular diagnostic candidates; 6 single-copy and 35 highly multi-copy (>40 BLAST hits), as determined through a self-BLAST-P alignment. Primers for PCR were designed in the 200-bp flanking region of the first exon for each candidate, and the candidates were validated against a diverse DNA panel containing Ceratocystis species, sweetpotato pathogens, and plants. After validation, two diagnostic candidates amplified only C. fimbriata DNA and were considered to be highly specific to the species. These genetic markers will serve as valuable diagnostic tools with multiple applications including the detection of C. fimbriata in seed, soil, and wash water in sweetpotato production., Competing Interests: The author(s) declare no conflict of interest.

The resistance of nickel-titanium endodontic instruments against cyclic fatigue failure remains a significant concern in clinical settings. This study aimed to assess the cyclic fatigue strength of five nickel-titanium rotary systems, while correlating the results with the instruments' geometric and metallurgical characteristics. A total of 250 new instruments (sizes S1/A1, S2/A2, F1/B1, F2/B2, F3/B3) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-Files systems underwent mechanical testing. Prior to experimental procedures, all instruments were meticulously inspected to identify irregularities that could affect the investigation. Using a stereomicroscope, design characteristics such as the number of spirals, length, spirals per millimeter, and average helical angle of the active blade were determined. The surface finishing characteristics of the instruments were examined using a scanning electron microscope. Differential scanning calorimetry was employed to establish the instruments' phase transformation temperatures, while energy-dispersive X-ray spectroscopy was utilized to analyze the elemental composition of the alloy. The instruments were subjected to cyclic fatigue testing within a stainless steel non-tapered artificial canal featuring a 6 mm radius and 86 degrees of curvature. Appropriate statistical tests were applied to compare groups, considering a significance level of 0.05. The assessed design characteristics varied depending on the instrument type. The least irregular surface finishing was observed in U-Files and Premium Taper Gold files, while the most irregular surface was noted in Go-Taper Flex. All instruments exhibited near-equiatomic proportions of nickel and titanium elements, whereas ProTaper Universal and U-Files instruments demonstrated lower phase transformation temperatures compared to their counterparts. Larger-sized instruments, as well as ProTaper Universal and U-Files, tended to display lower cyclic fatigue strength results. Overall, the design, metallurgical, and cyclic fatigue outcomes varied among instruments and systems. Understanding these outcomes may assist clinicians in making more informed decisions regarding instrument selection.

Aim: To compare eight large- and low-tapered heat-treated reciprocating instruments regarding their design, metallurgy, mechanical properties, and irrigation flow through an in silico model., Methodology: A total of 472 new 25-mm E-Flex Rex (25/.04 and 25/.06), Excalibur (25/.05), Procodile (25/.06), Reciproc Blue R25 (25/.08v), WaveOne Gold Primary (25/.07v), and Univy Sense (25/.04 and 25/.06) instruments were evaluated regarding their design (stereomicroscopy, scanning electron microscopy, and 3D surface scanning), metallurgy (energy-dispersive X-ray spectroscopy and differential scanning calorimetry), and mechanical performance (cyclic fatigue, torsional resistance, cutting ability, bending and buckling resistance). Computational fluid dynamics assessment was also conducted to determine the irrigation flow pattern, apical pressure, and wall shear stress in simulated canal preparations. Kruskal-Wallis and one-way anova post hoc Tukey tests were used for statistical comparisons (α = 5%)., Results: Instruments presented variations in blade numbers, helical angles, and tip designs, with all featuring non-active tips, symmetrical blades, and equiatomic nickel-titanium ratios. Cross-sectional designs exhibited an S-shaped geometry, except for WaveOne Gold. Univy 25/.04 and Reciproc Blue displayed the smallest and largest core diameters at D3. Univy 25/.04 and E-Flex Rec 25/.04 demonstrated the longest time to fracture (p < .05). Reciproc Blue and Univy 25/.04 exhibited the highest and lowest torque to fracture, respectively (p < .05). Univy 25/.04 and Reciproc Blue had the highest rotation angles, whilst E-Flex Rec 25/.06 showed the lowest angle (p < .05). The better cutting ability was observed with E-Flex Rec 25/.06, Procodile, Excalibur, and Reciproc Blue (p > .05). Reciproc R25 and E-Flex Rec showed the highest buckling resistance values (p < .05), with WaveOne Gold being the least flexible instrument. The impact of instruments' size and taper on wall shear stress and apical pressure did not follow a distinct pattern, although Univy 25/.04 and E-Flex Rec 25/.06 yielded the highest and lowest values for both parameters, respectively., Conclusions: Low-tapered reciprocating instruments exhibit increased flexibility, higher time to fracture, and greater angles of rotation, coupled with reduced maximum bending loads and buckling strength compared to large-tapered instruments. Nevertheless, low-tapered systems also exhibit lower maximum torque to fracture and inferior cutting ability, contributing to a narrower apical canal enlargement that may compromise the penetration of irrigants in that region., (© 2024 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Aim: To compare the design, metallurgy, and mechanical properties of four heat-treated reciprocating instruments coupled with the evaluation of the irrigation flow using an in silico model., Methodology: New EdgeOne Fire Primary, Easy-File Flex Regular 25, WaveOne Gold Primary and Reciproc Blue R25 instruments (n = 124) were initially evaluated regarding their design through stereomicroscopy, scanning electron microscopy and 3D surface scanning. In addition, energy-dispersive X-ray spectroscopy was utilized to determine their elemental composition, and differential scanning calorimetry tests to evaluate their phase transformation temperatures. Their mechanical performance was further assessed through torsional and bending tests. Using scans obtained from a real tooth and the instruments, a computational fluid dynamics assessment was conducted to determine the irrigation flow pattern, apical pressure, and wall shear stress in simulated canal preparation. Mood's median and One-way anova post hoc Tukey tests were used for statistical comparisons (α = 5%)., Results: Reciproc Blue exhibited a superior number of blades (n = 8), whereas EdgeOne Fire had the highest overall volume (4.38 mm 3 ) and surface area (32.32 mm 2 ). At the 3-mm axial level, EdgeOne Fire displayed the lowest core diameter (0.13 mm), while Reciproc Blue had the highest (0.16 mm). All blades were symmetrical, and the tips of the instruments were non-active but differed from each other. The most irregular surfaces were observed in EdgeOne Fire and Easy-File Flex. All instruments were manufactured from nickel-titanium alloys and exhibited distinct phase transformation temperatures. WaveOne Gold and Reciproc Blue demonstrated the highest maximum torque values (1.87 and 1.62 N cm, respectively), while the lowest was observed on EdgeOne Fire (1.21 N cm) (p < .05). The most flexible (p < .05) were EdgeOne Fire (angle of rotation: 602.6°; maximum bending load: 251.4 g.f) and Reciproc Blue (533.2° and 235.6 g.f). There were no significant differences observed in the irrigation flow among the four domains generated by the tested instruments., Conclusions: Despite observing variations in the design, phase transformation temperatures, and in the torsional and bending test outcomes among the four heat-treated reciprocating instruments, no significant differences were found in the irrigation flow pattern among the different groups in the simulated root canal preparations., (© 2023 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Aim: To assess the influence of a flat-side design on the geometry, metallurgy, mechanical performance and shaping ability of a novel nickel-titanium rotary instrument., Methodology: Sixty-five new 25-mm flat-side rotary instruments (size 25, taper 0.04) and their nonflat-side prototypes (n = 65) were assessed for major deformations and examined regarding macroscopic and microscopic design, determination of nickel and titanium elements ratio, measurement of phase transformation temperature and evaluation of mechanical performance parameters including time/cycles to fracture, maximum torque, angle of rotation, maximum bending and buckling strengths and cutting ability. Additionally, unprepared canal areas, volume of hard tissue debris and percentage reduction of dentine thickness were calculated for each tested instrument after preparing mesial canals of mandibular molars (n = 12), using micro-CT imaging. Statistical analyses were performed using the U-Mann-Whitney test and independent Student t-test (α = 5%)., Results: The number of spirals (n = 8) and blade direction (clockwise) were similar between both flat and nonflat instruments, whilst the helical angles were equivalent (⁓25°). Flat-instruments showed inconsistencies in the homogeneity of the gold colour on the flat-side surface, blade discontinuity, and incomplete and variable S-shaped cross-sections. The titanium-to-nickel ratios were equivalent, but significant differences in the R-phase finish and austenitic start phase transformation temperatures were observed between the flat and nonflat-side instruments. The flat-side instruments demonstrated superior cutting ability compared to the nonflat instruments, as well as, significantly lower values for time to fracture, rotation to fracture and maximum torque to fracture (p < .001). No statistical difference was observed between tested instruments regarding angle of rotation (p = .437), maximum bending (p = .152) and buckling load (p = .411). Preparation protocols using flat and nonflat instruments did not show any statistically significant differences (p > .05). All flat-side instruments exhibited deformation after shaping procedures., Conclusions: The flat-side instrument showcased enhanced cutting ability compared to its nonflat counterpart. However, it exhibited inferior performance in terms of time, rotation and maximum torque to fracture, along with distinct phase transformation temperatures. No differences were observed in the titanium-to-nickel ratios, angle of rotation, maximum bending, buckling load, preparation time, percentage of untouched canal walls, volume of hard tissue debris and percentage reduction of dentine thickness., (© 2023 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Aim: To compare two flat-side single-file rotary instruments with three single-file reciprocating systems through a multimethod assessment., Methodology: A total of 290 new NiTi single-file rotary (AF F One Blue 25/0.06 and Platinum V.EU 25/0.06) and reciprocating (One Files Blue R25, Reciproc Blue R25, Reciproc R25) instruments were selected, carefully examined for any major deformations, and evaluated regarding their macroscopic and microscopic design, nickel and titanium elements ratio, phase transformation temperatures, and mechanical performance (time/rotation to fracture, maximum torque, angle of rotation, microhardness, maximum bending, and buckling strengths). One-way anova post hoc Tukey, T-test, and nonparametric Mood's median tests were used for statistical comparisons (α = 5%)., Results: Tested instruments had identical blade counts and near-identical helical angles of approximately 24° (rotary instruments) and 151° (reciprocating instruments). The flat-side analysis revealed a few inconsistencies, such as discontinuity segments, different orientations, and gaps in the homogeneity of the bluish colour. Microscopically, flat-side instruments exhibited blade discontinuity and an incomplete S-shaped cross-section. The surface finish was smoother for One Files Blue and more irregular for both rotary instruments. There were distinct phase transformation temperatures amongst all instruments. All heat-treated instruments were in R-phase arrangement, and Reciproc was in R-phase plus austenite at test temperature (20°C). Compared with the reciprocating instruments, both flat-side instruments exhibited lower results in the cyclic fatigue tests using two different clockwise kinematics, maximum torque, angle of rotation, and maximum buckling strength (p < .05). The rotary systems also exhibited low flexibility (p < .05). AF F One Blue had the lowest microhardness, whilst Reciproc had the highest value., Conclusion: This multimethod investigation revealed that the flat-side rotary instruments underperformed the reciprocating instruments regarding cyclic fatigue (with two different clockwise kinematics), maximum torque, angle of rotation, maximum buckling strength, and flexibility. Manufacturing inconsistencies were also observed in some of the flat-side instruments, including discontinuity segments, different orientations, and in the homogeneity of their bluish colour given by the heat treatment., (© 2023 The Authors. International Endodontic Journal published by John Wiley & Sons Ltd on behalf of British Endodontic Society.)

Aim: This study aimed to compare three rotary instruments produced by the EDM process with the heat-treated ProTaper Gold system regarding design, metallurgy, mechanical properties and shaping ability., Methodology: HyFlex EDM (25/~), Neoniti (25/.06), EDMax (25/.06) and ProTaper Gold (25/.08v) instruments (n = 58 per group) were compared regarding design, metallurgy and mechanical performance. Unprepared canal areas were calculated for each system after preparation of mesiobuccal, mesiolingual and distal canals of mandibular molars (15 canals per group) using micro-CT technology. Statistical analyses were performed using One-way anova post-hoc Tukey and Kruskal-Wallis post-hoc Dunn's tests (α = 5%)., Results: All instruments had asymmetrical blades, no radial lands, no major defects and almost equiatomic nickel/titanium ratios, but different cross-section designs, tip geometries and surface appearances. Although instruments had distinct transformation temperature curves, they showed crystallographic martensitic arrangement at 21°C and mixed austenite plus R-phase at body temperature. Neoniti and HyFlex EDM showed similar results in all mechanical tests (p > .05), while EDMax and ProTaper Gold had similar time to fracture (p = .841), maximum bending load (p = .729), and cutting ability (p = .985). ProTaper Gold showed the highest torque to failure (p < .001) and HyFlex EDM had the lowest buckling resistance (p < .001). Mean percentages of unprepared canal areas ranged from 20.4% to 25.7% in the mesial canals, and from 20.8% to 26.2% in the distal canal, with no statistical differences among systems (p > .05)., Conclusions: Instruments' geometry and phase transformation temperatures influenced the results of the mechanical tests, but not their shaping ability., (© 2023 British Endodontic Society. Published by John Wiley & Sons Ltd.)

Objective: This study aimed to compare 3 reciprocating systems regarding design, metallurgy, mechanical properties, and shaping ability., Materials and Methods: New Reciproc Blue R25, WaveOne Gold Primary, and REX 25 instruments (n=41 per group) were analyzed regarding design, metallurgy, and mechanical performance, while shaping ability (untouched canal walls, volume of removed dentin, and hard tissue debris) was tested in 36 anatomically matched root canals of mandibular molars. Results were compared using one-way ANOVA post hoc Tukey and Kruskal-Wallis tests with a significant level set at 5%., Results: All instruments showed symmetrical cross sections with asymmetrical blades, no radial lands, no major defects, and an almost equiatomic nickel and titanium ratio. The highest R-phase start temperatures were observed with WaveOne Gold (46.1°C) and REX (44.8°C), while Reciproc Blue had the lowest R-phase start (34.5°C) and finish (20°C) temperatures. WaveOne Gold had the lowest time to fracture (169 s) and the highest maximum load (301.6 gf) (P <0.05). The maximum torque of Reciproc Blue (2.2 N.cm) and WaveOne Gold (2.1 N.cm) were similar (P >0.05), but lower than REX (2.6 N.cm) (P <0.05). No statistical differences were observed among instruments in the angle of rotation (P >0.05) and in the shaping ability in both mesial and distal canals (P >0.05)., Conclusion: Although the overall design, temperature transition phases and mechanical behavior parameters were different among tested instruments, they were similar in terms of shaping ability., Clinical Relevance: All tested heat-treated NiTi reciprocating systems showed similar shaping ability, without clinically significant errors., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Aim: To compare design, metallurgy and mechanical performance of the ProTaper (PT) Ultimate system with instruments of similar dimensions from the ProGlider, PT Gold and PT Universal systems., Methodology: New PT Ultimate instruments (n = 248) were compared with instruments of similar dimensions from ProGlider (n = 31), PT Gold (n = 155) and PT Universal (n = 155) systems regarding their number of spirals, helical angle, blade symmetry, tip geometry, surface finishing, nickel/titanium ratio, phase transformation temperatures and mechanical performance. One-way anova and nonparametric Mood's median tests were used for statistical comparison (α = 5%)., Results: All instruments had symmetrical blades without radial lands or flat sides, similar surface finishing and an almost equiatomic nickel/titanium ratio, whilst the number of spirals, helical angles and the tip geometry were different. PT Ultimate instruments showed 3 distinct heat treatments that matched with the colour of their metal wire. Slider and ProGlider instruments had similar R-phase start (Rs) and R-phase finish (Rf) temperatures. SX, F1, F2, F3 and Shaper instruments showed equivalent heat treatments (Rs ~45.6°C and Rf ~28.3°C) that were similar to their PT Gold counterparts (Rs ~47.9°C and Rf ~28.2°C), but completely distinct to the PT Universal ones (Rs ~16.2°C and Rf ~-18.2°C). Amongst the PT Ultimate instruments, the lowest maximum torques were observed in the SX (0.44 N cm), Slider (0.45 N cm) and Shaper (0.60 N cm) instruments, whilst the highest was noted in the FXL (4.90 N cm). PT Ultimate Slider and ProGlider had similar torsional (~0.40 N cm) and bending loads (~145.0 gf) (p = 1.000), whilst the other PT Ultimate instruments showed statistically significantly lower maximum torque, higher angle of rotation and lower bending load (higher flexibility) than their counterparts of the PT Universal and PT Gold systems., Conclusions: The PT Ultimate system comprises instruments with 3 distinct heat treatments that showed similar phase transformation temperatures to their heat-treated analogues. PT Ultimate instruments presented lower torsional strength and superior flexibility than their counterparts, whilst maximum torque, angle of rotation and bending loads progressively increased with their sizes., (© 2022 The Authors. International Endodontic Journal published by John Wiley & Sons Ltd on behalf of British Endodontic Society.)

Introduction: The aim of this study was to compare E1-Irrisonic (Helse Ultrasonics, Ocoee, FL) and Irri Black (Helse Ultrasonics), a novel ultrasonic tip with diamondlike carbon treatment, regarding their design, metallurgy, microhardness, bending resistance, and time to fracture under the oscillatory fatigue test., Methods: A total of 17 E1-Irrisonic and 17 Irri Black new ultrasonic tips were selected. The tip geometry and surface finishing were assessed using scanning electron microscopy. The elemental composition was defined by energy-dispersive X-ray spectroscopy. Hardness Knoop was calculated using a microhardness tester. The maximum load required to displace the instrument in 45° was recorded in gram/force, oscillatory fatigue was measured in seconds at the moment of instrument fracture, and the size of the separate fragments was determined in millimeters. The Student t test was used for statistical comparison (α = 5%)., Results: Scanning electron microscopic analyses revealed that E1-Irrisonic had a flat end tip, whereas a noncutting rounded tip was observed in Irri Black. The surface of E1-Irrisonic was smoother than Irri Black, which was irregular. Energy-dispersive X-ray spectroscopic analyses showed that the elemental compositions of the E1-Irrisonic and Irri Black tips were consistent with stainless steel and titanium-aluminum alloys, respectively. Irri Black showed significantly higher bending load resistance, time to fracture under oscillatory motion, and hardness Knoop than the E1-Irrisonic tip (P < .05), whereas the length of fragments was similar (P > .05)., Conclusion: Diamondlike carbon treatment improved hardness Knoop and reduced the flexibility of the Irri Black ultrasonic tip, improving its time to fracture under oscillatory motion compared with the nontreated E1-Irrisonic tip., (Copyright © 2022 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Circulating tumor cells (CTCs) represent an interesting source of biomarkers for diagnosis, prognosis, and the prediction of cancer recurrence, yet while they are extensively studied in oncobiology research, their diagnostic utility has not yet been demonstrated and validated. Their scarcity in human biological fluids impedes the identification of dangerous CTC subpopulations that may promote metastatic dissemination. In this Perspective, we discuss promising techniques that could be used for the identification of these metastatic cells. We first describe methods for isolating patient-derived CTCs and then the use of 3D biomimetic matrixes in their amplification and analysis, followed by methods for further CTC analyses at the single-cell and single-molecule levels. Finally, we discuss how the elucidation of mechanical and morphological properties using techniques such as atomic force microscopy and molecular biomarker identification using nanopore-based detection could be combined in the future to provide patients and their healthcare providers with a more accurate diagnosis.

Standard in vitro cell cultures are one of the pillars of biomedical sciences. However, there is increasing evidence that 2D systems provide biological responses that are often in disagreement with in vivo observations, partially due to limitations in reproducing the native cellular microenvironment. 3D materials that are able to mimic the native cellular microenvironment to a greater extent tackle these limitations. Here, we report Porous yet Dense (PyD) type I collagen materials obtained by ice-templating followed by topotactic fibrillogenesis. These materials combine extensive macroporosity, favouring the cell migration and nutrient exchange, as well as dense collagen walls, which mimic locally the extracellular matrix. When seeded with Normal Human Dermal Fibroblasts (NHDFs), PyD matrices allow for faster and more extensive colonisation when compared with equivalent non-porous matrices. The textural properties of the PyD materials also impact cytoskeletal and nuclear 3D morphometric parameters. Due to the effectiveness in creating a biomimetic 3D environment for NHDFs and the ability to promote cell culture for more than 28 days without subculture, we anticipate that PyD materials could configure an important step towards in vitro systems applicable to other cell types and with higher physiological relevance.

Here, we report the draft genome sequence of Calonectria pteridis, the causal agent of Calonectria leaf blight in eucalyptus plantations in Brazil. The 58,373,473-bp genome assembly consists of 1,167 scaffolds, with a GC content of 50.21%. These genomic data can contribute to future studies involving the biology, adaptability, and pathogenicity of C. pteridis.

Instruments' mechanical strength and flexibility are traditionally tested by running cyclic fatigue, torsional, bending, buckling, and microhardness tests. Several cyclic fatigue test models have been used in endodontics, all capable of providing a curved trajectory for the instrument to rotate. Cyclic fatigue testing allows the identification of conditions that may affect the fatigue strength outcomes, such as the canal radius and degree of curvature, handpiece static versus dynamic motions, test temperature, kinematics, instrument previously wear and sterilization cycles, or instrument's size and metal alloy features. Because of the international test specifications for both torsional and bending tests, the variations of their models are not as many as for cyclic fatigue. These tests have also identified conditions capable of affecting the outcomes, such as kinematics, instruments' preloading, cross-sectional diameters, or alloy heat treatments. Buckling and microhardness are less common, with the metal alloy being considered to have a major influence on the results. Instruments' mechanical testing, having all these individual conditions as independent variables, allowed the understanding of them and molded the way the technical procedures are performed clinically. Even though the artificiality and simplicity of these tests will hardly mimic real working situations, and independent of being capable of producing cornerstone knowledge, these tests are also associated with inconsistency, a lack of reproducibility, and low external validity. Several attempts have been made to increase the generalizability of the outcomes by adding test settings that intend to mimic the clinical condition. Although pertinent, these settings may also add variabilities inherent to their concepts and practical applications in the laboratory environment. Although the actual studies should be seen as laboratory mechanical tests that measure very specific parameters under very particular conditions and that by far do not mimic the clinical condition, the lower validity drawback seems to be possible to be minimized when achieving a comprehensive understanding of the instrument behavior. A finite element method and/or a multimethod research approach may lead to superior data collection, analysis, and interpretation of results, which when associated with a reliable confounding factor control and proper study designs may be helpful tools and strategies in order to increase the reliability of the outcomes., (Copyright © 2022 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

This study aimed to compare three endodontic rotary systems. The new Genius Proflex (25/0.04), Vortex Blue (25/0.04), and TruNatomy (26/0.04v) instruments (n = 41 per group) were analyzed regarding design, metallurgy, and mechanical performance, while shaping ability (untouched canal walls, volume of removed dentin and hard tissue debris) was tested in 36 anatomically matched root canals of mandibular molars. The results were compared using one-way ANOVA, post hoc Tukey, and Kruskal−Wallis tests, with a significance level set at 5%. All instruments showed symmetrical cross-sections, with asymmetrical blades, no radial lands, no major defects, and almost equiatomic nickel−titanium ratios. Differences were noted in the number of blades, helical angles, cross-sectional design, and tip geometry. The Genius Proflex and the TruNatomy instruments had the highest and lowest R-phase start and finish temperatures, as well as the highest and lowest time and cycles to fracture (p < 0.05), respectively. The TruNatomy had the highest flexibility (p < 0.05), while no differences were observed between the Genius Proflex and the Vortex Blue (p > 0.05). No differences among tested systems were observed regarding the maximum torque, angle of rotation prior to fracture, and shaping ability (p > 0.05). The instruments showed similarities and differences in their design, metallurgy, and mechanical properties. However, their shaping ability was similar, without any clinically significant errors. Understanding these characteristics may help clinicians to make decisions regarding which instrument to choose for a particular clinical situation.

Silk from Bombyx mori is one of the most exciting materials in nature. The apparently simple arrangement of its two major components─two parallel filaments of silk fibroin (SF) coated by a common sericin (SS) sheath─provides a combination of mechanical and surface properties that can protect the moth during its most vulnerable phase, the pupal stage. Here, we recapitulate the topology of native silk fibers but shape them into three-dimensional porous constructs using an unprecedented design strategy. We demonstrate, for the first time, the potential of these macroporous silk foams as dermal patches for wound protection and for the controlled delivery of Rifamycin (Rif), a model antibiotic. The method implies (i) removing SS from silk fibers; (ii) shaping SF solutions into macroporous foams via ice-templating; (iii) stabilizing the SF macroporous foam in a methanolic solution of Rif; and (iv) coating Rif-loaded SF foams with a SS sheath. The resulting SS@SF foams exhibit water wicking capacity and accommodate up to ∼20% deformation without detaching from a skin model. The antibacterial behavior of Rif-loaded SS@SF foams against Staphylococcus aureus on agar plates outperforms that of SF foams (>1 week and 4 days, respectively). The reassembly of natural materials as macroporous foams─illustrated here for the reconstruction of silk-based materials─can be extended to other multicomponent natural materials and may play an important role in applications where controlled release of molecules and fluid transport are pivotal.

A multimethod study was conducted to assess the differences between original (PG-OR) and counterfeit (PG-CF) ProGlider instruments regarding design, metallurgical features, and mechanical performance. Seventy PG-OR and PG-CF instruments (n = 35 per group) were evaluated regarding the number of spirals, helical angles, and measuring line position by stereomicroscopy, while blade symmetry, cross-section geometry, tip design, and surface were assessed by scanning electron microscopy. Energy-dispersive X-ray spectroscopy and differential scanning calorimetry were used to identify element ratio and phase transformation temperatures, while cyclic fatigue, torsional, and bending testing were employed to assess their mechanical performance. An unpaired t-test and nonparametric Mann−Whitney U test were used to compare instruments at a significance level of 5%. Similarities were observed in the number of spirals, helical angles, blade symmetry, cross-sectional geometries, and nickel−titanium ratios. Measuring lines were more reliable in the original instrument, while differences were noted in the geometry of the tips (sharper tip for the original and rounded for the counterfeit) and surface finishing with PG-CF presenting more surface irregularities. PG-OR showed significantly more time to fracture (118 s), a higher angle of rotation (440°), and a lower maximum bending load (146.3 gf) (p < 0.05) than PG-CF (p < 0.05); however, maximum torque was similar for both instruments (0.4 N.cm) (p > 0.05). Although the tested instruments had a similar design, the original ProGlider showed superior mechanical behavior. The results of counterfeit ProGlider instruments were unreliable and can be considered unsafe for glide path procedures.

Objectives: To compare the design, metallurgy, mechanical performance, and canal preparation of 5 rotary systems., Material and Methods: A total of 735 25-mm NiTi instruments (sizes 0.17[0.18]/.02v, 0.20/.04v, 0.20/.07v, 0.25/.08v, 0.30/.09v) from ProTaper Gold, ProTaper Universal, Premium Taper Gold, Go-Taper Flex, and U-File systems were compared regarding overall geometry and surface finishing (stereomicroscopy and scanning electron microscopy), nickel and titanium ratio (energy-dispersive spectroscopy), phase transformation temperatures (differential scanning calorimetry), mechanical performance (torsional and bending tests), and unprepared canal surface (micro-CT). One-way ANOVA and Mood's median tests were used for statistical comparisons with a significance level set at 5%., Results: Stereomicroscopic analysis showed more spirals and high helical angles in the Premium Taper Gold system. All sets of instruments had symmetrical spirals, no radial lands, no major defects, and an almost equiatomic ratio between nickel and titanium elements, while differences were observed in their tips' geometry and surface finishing. At room temperature (20 °C), DSC test revealed martensitic characteristics for ProTaper Gold and Go-Taper Flex, and mixed austenite plus R-phase for the Premium Taper Gold, while ProTaper Universal and U-Files had full austenitic characteristics. Overall, larger instruments had higher torque resistance and bending load values than smaller ones, while a lack of consistency and mixed values were observed in the angle of rotation. The 0.25/.08v and 0.30/.09v instruments of ProTaper Universal and U-File had the highest maximum torques, the lowest angles of rotation, and the highest bending loads than other tested systems (P < .05). No significant difference was noted regarding the untouched root canal walls after preparation with the tested systems (P > .05)., Conclusions: Although differences observed in the overall geometry and phase transformation temperatures have influenced the results of mechanical tests, unprepared canal surface areas were equivalent among systems., Clinical Relevance: Root canal preparation systems with similar geometries might present different mechanical behaviors but equivalent shaping ability., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Background: The aim of this study was to comprehensively evaluate the cyclic fatigue strength of ProGlider, Edge Glide Path, and R-Pilot instruments., Methods: Sixty-three instruments were submitted to a multimethod evaluation. Their design was analyzed by stereomicroscopy and scanning electron microscopy, including the number of blades, helical angle means, cross-sectional design, surface finishing, and symmetry. Energy-dispersive X-ray spectroscopy was used determine the nickel/titanium elements ratio, and differential scanning calorimetry determined the instruments' phase transformation temperatures. The cyclic fatigue tests were conducted in an artificial canal with a 6 mm radius and 86 degrees of curvature. The Mood's median test and one-way ANOVA were used to determine differences, with the significance level set at 0.05., Results: The ProGlider presented the highest number of blades ( n = 21), while R-Pilot had the highest helical angles (26.4°). Differences were noted in the instruments' cross-sections and surface finishing. The ProGlider and R-Pilot showed some similarities regarding the phase transformation temperatures but differed from the Edge Glide Path. All alloys showed an almost equiatomic nickel/titanium ratio. The R-Pilot instruments showed a significantly higher ( p < 0.05) time to fracture than both the other files., Conclusion: Reciprocating R-Pilot instruments showed a higher cyclic fatigue time to fracture than the ProGlider and Edge Glide Path rotary files.

The structural and thermophysical characteristics of an Ni-rich NiTi alloy rod produced on a laboratory scale was studied. The soak temperature of the solution heat-treatment steps above 850 °C taking advantage of the precipitate dissolution to provide a matrix homogenization, but it takes many hours (24 to 48) when used without thermomechanical steps. Therefore, the suitable reheating to apply between the forging process steps is very important, because the product's structural characteristics are dependent on the thermomechanical processing history, and the time required to expose the material to high temperatures during the processing is reduced. The structural characteristics were investigated after solution heat treatment at 900 °C and 950 °C for 120 min, and these heat treatments were compared with as-forged sample structural characteristics (one hot deformation step after 800 °C for a 30 min reheat stage). The phase-transformation temperatures were analyzed through differential scanning calorimetry (DSC), and the structural characterization was performed through synchrotron radiation-based X-ray diffraction (SR-XRD) at room temperature. It was observed that the solution heat treatment at 950 °C/120 min presents a lower martensitic reversion finish temperature (A f ); the matrix was fully austenitic; and it had a hardness of about 226 HV. Thus, this condition is the most suitable for the reheating stages between the hot forging-process steps to be applied to this alloy to produce materials that can display a superelasticity effect, for applications such as crack sensors or orthodontic archwires.

Recognizing the imperative to evaluate species recovery and conservation impact, in 2012 the International Union for Conservation of Nature (IUCN) called for development of a "Green List of Species" (now the IUCN Green Status of Species). A draft Green Status framework for assessing species' progress toward recovery, published in 2018, proposed 2 separate but interlinked components: a standardized method (i.e., measurement against benchmarks of species' viability, functionality, and preimpact distribution) to determine current species recovery status (herein species recovery score) and application of that method to estimate past and potential future impacts of conservation based on 4 metrics (conservation legacy, conservation dependence, conservation gain, and recovery potential). We tested the framework with 181 species representing diverse taxa, life histories, biomes, and IUCN Red List categories (extinction risk). Based on the observed distribution of species' recovery scores, we propose the following species recovery categories: fully recovered, slightly depleted, moderately depleted, largely depleted, critically depleted, extinct in the wild, and indeterminate. Fifty-nine percent of tested species were considered largely or critically depleted. Although there was a negative relationship between extinction risk and species recovery score, variation was considerable. Some species in lower risk categories were assessed as farther from recovery than those at higher risk. This emphasizes that species recovery is conceptually different from extinction risk and reinforces the utility of the IUCN Green Status of Species to more fully understand species conservation status. Although extinction risk did not predict conservation legacy, conservation dependence, or conservation gain, it was positively correlated with recovery potential. Only 1.7% of tested species were categorized as zero across all 4 of these conservation impact metrics, indicating that conservation has, or will, play a role in improving or maintaining species status for the vast majority of these species. Based on our results, we devised an updated assessment framework that introduces the option of using a dynamic baseline to assess future impacts of conservation over the short term to avoid misleading results which were generated in a small number of cases, and redefines short term as 10 years to better align with conservation planning. These changes are reflected in the IUCN Green Status of Species Standard., (© 2021 The Authors. Conservation Biology published by Wiley Periodicals LLC on behalf of Society for Conservation Biology.)

Introduction: This study aims to compare the design, metallurgy, microhardness, and mechanical properties of 3 glide path nickel-titanium (NiTi) instruments., Methods: A total of 132 ProGlider (Dentsply Sirona, Ballaigues, Switzerland), Edge Glide Path (EdgeEndo, Johnson City, TN), and R-Pilot instruments (VDW, Munich, Germany) (44 per group) were selected. Design was assessed through stereomicroscopy (blades, helical angle, measuring lines, and deformation) and scanning electron microscopy (symmetry, cross section, tip, and surface finishing). NiTi ratios were measured by energy-dispersive X-ray spectroscopy and phase transformation temperatures by differential scanning calorimetry. Microhardness and mechanical performance (torsion, bending, and buckling resistance tests) were also evaluated. Statistical analyses were performed with the Mood median test with a significance set at 5%., Results: The Edge Glide Path had the lowest number of blades and the R-Pilot the greatest helical angle. All instruments had an almost equiatomic NiTi ratio, while showing different cross sections and tip geometries. The Edge Glide Path had a smoother surface finishing. The R-Pilot showed martensitic characteristics at room temperature, whereas mixed austenite plus R-phase was observed in the other instruments. The R-Pilot had higher results on the microhardness (436.8 hardness Vickers number), maximum torsion (0.9 Ncm), and buckling load (0.7 N) tests (P < .05), whereas the Edge Glide Path had a superior angle of rotation (683.5°) and the ProGlider was more flexible (144.1 gf) (P < .05)., Conclusions: Differences in the design of the instruments and the phase transformation temperatures accounted for their mechanical behavior. The R-Pilot showed the highest torque, buckling, and microhardness, whereas the ProGlider instrument was the most flexible., (Copyright © 2021 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Seeding materials with living cells has been-and still is-one of the most promising approaches to reproduce the complexity and the functionality of living matter. The strategies to associate living cells with materials are limited to cell encapsulation and colonization, however, the requirements for these two approaches have been seldom discussed systematically. Here we propose a simple two-dimensional map based on materials' pore size and the cytocompatibility of their fabrication process to draw, for the first time, a guide to building cellularized materials. We believe this approach may serve as a straightforward guideline to design new, more relevant materials, able to seize the complexity and the function of biological materials. This article is part of the theme issue 'Bio-derived and bioinspired sustainable advanced materials for emerging technologies (part 1)'.

Sepiolite and palygorskite fibrous clay minerals are 1D silicates featuring unique textural and structural characteristics useful in diverse applications, and in particular as rheological additives. Here we report on the ability of grinded sepiolite to generate highly viscous and stable hydrogels by sonomechanical irradiation (ultrasounds). Adequate drying of such hydrogels leads to low-density xerogels that show extensive fiber disaggregation compared to the starting sepiolite-whose fibers are agglomerated as bundles. Upon re-dispersion in water under high-speed shear, these xerogels show comparable rheological properties to commercially available defibrillated sepiolite products, resulting in high viscosity hydrogels that minimize syneresis. These colloidal systems are thus very interesting as they can be used to stabilize many diverse compounds as well as nano-/micro-particles, leading to the production of a large variety of composites and nano/micro-architectured solids. In this context, we report here various examples showing how colloidal routes based on sepiolite hydrogels can be used to obtain new heterostructured functional materials, based on their assembly to solids of diverse topology and composition such as 2D and 1D kaolinite and halloysite aluminosilicates, as well as to the 2D synthetic Mg,Al-layered double hydroxides (LDH)., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Ruiz-Hitzky, Ruiz-García, Fernandes, Lo Dico, Lisuzzo, Prevot, Darder and Aranda.)

Freeze-drying is the most widespread method to preserve protein drugs and vaccines in a dry form facilitating their storage and transportation without the laborious and expensive cold chain. Extending this method for the preservation of natural biomaterials and cells in a dry form would provide similar benefits, but most results in the domain are still below expectations. In this review, rather than consider freeze-drying as a traditional black box we "break it" through a detailed process thinking approach. We discuss freeze-drying from process thinking aspects, introduce the chemical, physical, and mechanical environments important in this process, and present advanced biophotonic process analytical technology. In the end, we review the state of the art in the freeze-drying of the biomaterials, extracellular vesicles, and cells. We suggest that the rational design of the experiment and implementation of advanced biophotonic tools are required to successfully preserve the natural biomaterials and cells by freeze-drying. We discuss this change of paradigm with existing literature and elaborate on our perspective based on our new unpublished results., (Copyright © 2021 The Authors. Published by Elsevier B.V. All rights reserved.)

The interaction between the stress-induced martensitic transformation and resistivity behavior of superelastic NiTi shape memory alloy (SMA) was studied. Strain-controlled low-cycle fatigue up to 6% was monitored by in situ electrical resistivity measurements. The experimental results show that a great motion of martensite fronts results in a significant accumulation of defects, as evidenced by transmission electron microscopy (TEM), before and after the tensile cycles. This gives rise to an overall increase of the resistivity values up to the maximum deformation. Therefore, the research suggests that shape memory alloy wire has great potential as a stress sensor inside bulk materials.

The authors report a very rare case of bilateral occipital condyle fractures (OCF) that was associated with complete separation fracture of the inferior clivus resulting in craniocervical dislocation alongside dissociation of C1-C2 joint complex. Also, a new type of the Anderson and Montesano classification system is presented with two subtypes of injuries. Type IVA occurs when the OCF is associated a clivus avulsion fracture, while Type IVB occurs when the OCF is associated with complete "en piece" separation fracture of the inferior clivus. Both Type IV injuries are considered highly unstable, and surgical fixation is the recommended treatment option., (© 2021. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Biological tissues rich in type I collagen exhibit specific hierarchical fibrillar structures together with remarkable mechanical toughness. However, the role of collagen alone in their mechanical response at different structural levels is not fully understood. Here, it is proposed to rationalize such challenging interplay from a materials science perspective through the subtle control of this protein self-assembly in vitro. It is relied on a spray-processing approach to readily use the collagen phase diagram and set a palette of biomimetic self-assembled collagen gels in terms of suprafibrillar organization. Their mechanical responses unveil the involvement of mechanisms occurring either at fibrillar or suprafibrillar scales. Noticeably, both modulus at early stage of deformations and tensile toughness probe the suprafibrillar organization, while durability under cyclic loading and stress relaxation reflect mechanisms at the fibril level. By changing the physicochemical environment, the interfibrillar interactions are modified toward more biomimetic mechanical responses. The possibility of making tissue-like materials with versatile compositions and toughness opens perspectives in tissue engineering., (© 2021 Wiley-VCH GmbH.)

Aim: To compare the ProTaper Next (PTN) system with a replica-like and a counterfeit system regarding design, metallurgy, mechanical performance and shaping ability., Methodology: Replica-like (X-File) and counterfeit (PTN-CF) instruments were compared to the PTN system regarding design (microscopy), phase transformation temperatures (differential scanning calorimetry), nickel-titanium ratio (energy-dispersive X-ray spectroscopy), cyclic fatigue, torsional resistance, bending strength, and untouched canal areas in extracted mandibular molars (micro-CT). anova, post hoc Tukey's and Kruskal-Wallis tests were used according to normality assessment (Shapiro-Wilk test) with the significance level set at 5%., Results: Overall similarities in design and nickel-titanium (Ni/Ti) ratio were observed amongst instruments with the X-File having a smoother surface finish. PTN and PTN-CF had mixed austenite plus R-phase (R-phase start approximately at 45 ºC and near 30 ºC, respectively), whilst X-File instruments were austenitic (R-phase started at approximately at 17 ºC) at room temperature (20 ºC). PTN-CF had the greatest inconsistency in the phase transformation temperatures. Time to fracture of PTN-CF X2 and X3 was significantly shorter than PTN and X-File instruments (P < 0.05), whilst no difference was noted in maximum torque to fracture amongst the tested systems (P > 0.05). X-Files and PTN-CF had a stress-induced phase change during bending load. Mean unprepared surface areas of root canals were 25.8% (PTN), 31.1% (X-File) and 32.5% (PTN-CF) with no significant difference amongst groups (P > 0.05)., Conclusion: Similarities amongst the systems were noted in the Ni/Ti ratio and maximum torque to fracture, whilst differences were observed in the design, phase transformation temperatures and mechanical behaviour. The ProTaper Next counterfeit instruments could be considered as the less secure system considering its low-cyclic fatigue resistance. Apart from these differences, the unprepared canal surface areas, obtained with the tested systems, were similar., (© 2020 International Endodontic Journal. Published by John Wiley & Sons Ltd.)

Ice templating - or freeze casting - has flourished in multiple domains as a straightforward process to shape solutions and particle suspensions into macroporous materials. Longtime used as a process to shape colloidal suspensions into lightweight ceramics, the use of ice templating has evolved to fabricate materials that mimic the architecture of biological tissues such as nacre and bone. Recently, the technique has been used to shape biopolymers for cell culture systems and tissue engineering applications and eventually to allow the fabrication of biomaterials containing living cells. Here we review how ice templating has progressed to cope with intrinsically labile biological matter and how these advances may shape the future 3D cell culture, tissue engineering and ultimately, cryobiology.

Introduction: This study aimed to compare the ProTaper Universal (PTU; Dentsply Maillefer, Ballaigues, Switzerland) system with 6 replicalike instruments regarding instrument design, mechanical performance, and alloy characteristics., Methods: New rotary instruments (size 20/.07v) of PTU and 6 replicalike systems (EdgeTaper [EdgeEndo, Johnson City, TN], U-File [Dentmark, Ludhiana, India], Go-Taper Universal [Access, Shenzhen, China], Super Files [Flydent, Shenzhen, China], Multitaper [Proclinic Expert, Besançon, France], and Pluri Taper [Bestdent, Shenzhen, China]) (n = 329) were selected and evaluated regarding their design, mechanical performance, and metallurgical characteristics. The results were compared using the nonparametric Mood median test and 1-way analysis of variance with the significance level set at 0.05., Results: Replicalike instruments were similar to PTU regarding design, maximum torque to fracture (P > .05), and ratio of nickel and titanium elements. Scanning electron microscopy revealed differences in the geometry of the tip and finishing surfaces. Time to fracture of Go-Taper Universal (50.0 seconds) was similar to PTU (44.0 seconds) (P > .05), but the U-File (63.5 seconds), Edge Taper (87.5 seconds), and Super Files (130 seconds) showed significantly higher values (P < .05). The highest maximum torque was observed in the Super Files instrument (P < .05), but no statistical difference was noted among the other instruments (P > .05). The angle of rotation before rupture of the Multitaper (574°) and Pluri Taper (481°) was higher than PTU (354°) (P < .05). Differential scanning calorimetric analysis showed clear differences on the transformation temperatures among the tested instruments. The R-phase start and finish temperatures of PTU were 11.0°C and -18.0°C, respectively., Conclusions: Overall, replicalike instruments were similar to PTU regarding the torsional resistance, geometric design, and near equiatomic proportions of nickel and titanium elements. In 3 of the 4 mechanical tests, the EdgeTaper (torque, angle of rotation, and bending load) and Go-Taper Universal (time to fracture, torque, and angle of rotation) systems were similar to PTU., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Cellulose nanocrystals (CNC) and xyloglucan (XG) were used to construct new aerogels inspired by the hierarchical organization of wood tissue, i.e., anisotropic porous cellular solid with pore walls containing oriented and stiff cellulose nanorods embedded in hemicellulose matrix. Aerogels with oriented or disordered pores were prepared by directional and non-directional freeze-casting from colloidal dispersions of XG and CNC at different ratios. XG addition induced a clear improvement of the mechanical properties compared to the CNC aerogel, as indicated by the Young modulus increase from 138 kPa to 610 kPa. The addition of XG changed the pore morphology from lamellar to alveolar and it also decreased the CNC orientation (the Hermans' orientation factor was 0.52 for CNC vs 0.36-0.40 for CNC-XG). The aerogels that contained the highest proportion of XG also retained their structural integrity in water without any chemical modification. These results open the route to biobased water-resistant materials by an easy and green strategy based on polymer adsorption rather than chemical crosslinking., (Copyright © 2020. Published by Elsevier Ltd.)

Fractionated reaction time can be used to determine distinct epochs known as pre-motor, response and movement times (MTs) of a reaction time task. The purpose of this study was to compare elite and novice athletes performing a taekwondo kick in terms of the fractionated reaction time and electromyography (EMG) activation patterns of the muscles of the striking lower limb and the lower back. We hypothesised that the pre-motor time, response time (RT) and MT would be the shorter for elite athletes compared to novices. We collected data on 13 elite and 10 novice athletes when performing a roundhouse kick. The experiment included EMG electrodes placed on five low back and lower extremity muscles and an electrogoniometer placed on the kicking knee. We found that pre-motor time was shorter and the RT was longer for elite athletes than novice athletes. Moreover, the integrated EMG of the main knee extensor does not differ between groups though other leg and trunk muscles do. The results allow coaches and teachers to understand this particular taekwondo kicking movement which could ultimately improve the technique in order to establish training and teaching goals.

Introduction: This study aimed to compare the mechanical and metallurgical properties and shaping ability of different rotary systems using a multimethod approach., Methods: New NeoNiti A1 (Neolix SAS, Châtres-La-Forêt, France), HyFlex EDM One File (Coltène/Whaledent, Altstätten, Switzerland), ProTaper Gold F2 (Dentsply Maillefer, Ballaigues, Switzerland), and ProTaper Universal F2 (Dentsply Maillefer) rotary instruments were tested regarding cyclic fatigue, torsional resistance, design, and morphologic characteristics using scanning electron microscopy, metal alloy characterization using differential scanning calorimetry, and energy-dispersive X-ray spectroscopy. Additionally, their shaping ability on the preparation of 48 canals of maxillary molars was evaluated using micro-computed tomographic technology. Mechanical and metallurgical analyses were compared using analysis of variance post hoc Tukey tests, whereas the independent Student t test was used to compare the shaping ability of the ProTaper systems or the thermomechanically treated instruments. The significance level was set at 5%., Results: The highest cyclic fatigue was observed with the NeoNiti and HyFlex EDM instruments (P > .05), whereas HyFlex EDM had the highest angular rotation to fracture (P < .05). Scanning electron microscopic/energy-dispersive X-ray spectroscopic analyses confirmed similarities in the instruments' design and an almost equiatomic composition of the systems. Differential scanning calorimetry showed that ProTaper Gold had higher transformation temperatures than ProTaper Universal, whereas a similar transformation was observed between NeoNiti and HyFlex. Micro-computed tomographic analysis revealed that, despite the fact that none of the systems was able to prepare all root canal walls, no statistical differences were observed in either ProTaper systems (P > .05) or the thermomechanically treated instruments (P > .05)., Conclusions: Apart from differences in the mechanical tests and metallurgical characterization, systems with comparable instrument dimensions and preparation protocols showed a similar percentage of untouched surface areas in the root canal preparation of maxillary molars., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Cryopreservation is the only fully established procedure to extend the lifespan of living cells and tissues, a key to activities spanning from fundamental biology to clinical practice. Despite its prevalence and impact, the central aspects of cryopreservation, such as the cell's physicochemical environment during freezing, remain elusive. Here we address that question by coupling in situ microscopic directional freezing to visualize cells and their surroundings during freezing with the freezing-medium phase diagram. We extract the freezing-medium spatial distribution in cryopreservation, providing a tool to describe the cell vicinity at any point during freezing. We show that two major events define the cells' local environment over time: the interaction with the moving ice front and the interaction with the vitreous moving front, a term we introduce here. Our correlative strategy may be applied to cells relevant to clinical research and practice and may help in the design of new cryoprotective media based on local physicochemical cues.

Introduction: The aim of this study was to evaluate the cyclic fatigue resistance of 3 replicalike rotary instruments compared with their original brand systems using continuous rotation and optimum torque reverse (OTR) kinematics., Methods: New F1 rotary instruments (n = 20 per group) from ProTaper Universal (Dentsply Maillefer, Ballaigues, Switzerland) and ProTaper Gold (Dentsply Maillefer) original brand systems were compared with 3 replicalike instruments (U-File [Dentmark, Ludhiana, India], Super Files [Shenzhen Flydent Medical, Shenzhen, China], and Super Files Blue [Shenzhen Flydent Medical]) regarding cyclic fatigue resistance. In each group, the selected instruments were randomly distributed into 2 subgroups (n = 10) according to the kinematics. In the rotary group (ROT), the instruments were activated with a continuous clockwise rotation (300 rpm, 1.5 Ncm), whereas in the OTR group, asymmetric oscillatory motion was performed setting the OTR function at 300 rpm and adjusting the torque limit at the minimum level using the TriAuto ZX2 motor (J Morita, Kyoto, Japan). The time to fracture was recorded and statistically compared according to the kinematics (ROT × OTR) and the instrument type (replicalike × original brand) using the independent sample t test (α = 0.05). Additionally, the metal alloy characterization of each system was performed by differential scanning calorimetry and energy-dispersive X-ray spectroscopy., Results: Statistical analysis revealed significantly higher time to fracture for all rotary systems tested in OTR motion compared with continuous rotation (P < .05) with a mean percentage increase ranging from 52.1% (ProTaper Gold) to 156.7% (U-File). The replicalike instruments showed a significantly higher time to fracture compared with the respective original brand instruments in either ROT or OTR motion (P < .05). Replicas presented austenitic temperatures above the ones displayed by the original brands and an almost equiatomic ratio between nickel and titanium elements., Conclusions: OTR motion significantly improved the fatigue resistance of both original and replicalike systems. The replicas showed higher cyclic fatigue resistance than original brand instruments and higher transition temperatures to the austenitic phase., (Copyright © 2020 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.)

Background: New technologies and inadequate management of work might have negative impact on the mental health of workers., Objective: To investigate factors associated with the prevalence of burnout and levels of job satisfaction among emergency department and intensive care providers in a large public hospital., Methods: Cross-sectional study with 91 healthcare workers, who were administered the self-report questionnaires Maslach Burnout Inventory - Human Services Survey (MBI-HSS) and Job Satisfaction Scale (JSS20/23)., Results: The sample was predominantly composed of women (58.2%), married workers or with a stable partner (52.8%), having attended graduate studies (75.8%) and with average age 37 years old. Twenty-five percent of the participants exhibited emotional exhaustion and dissatisfaction with the work environment and hierarchical relationships, and 66% had already thought of leaving the profession. Allocation to intensive care unit, lack of professional growth opportunities, dissatisfaction with hierarchical relationships, nursing profession, and having thought of leaving the profession explained 55% of the prevalence of emotional exhaustion., Conclusion: Positive correlation between emotional exhaustion and job dissatisfaction was the earliest identifiable indicator of burnout. Periodic evaluations for early detection and prevention are important to reduce occupational disorders, and consequently improve the quality and safety of care delivery.

What is the pressure generated by ice crystals during ice-templating? This work addresses this crucial question by estimating the pressure exerted by oriented ice columns on a supramolecular probe composed of a lipid lamellar hydrogel during directional freezing. This process, also known as freeze-casting, has emerged as a unique processing technique for a broad class of organic, inorganic, soft, and biological materials. Nonetheless, the pressure exerted during and after crystallization between two ice columns is not known, despite its importance with respect to the fragility of the frozen material, especially for biological samples. By using the lamellar period of a glycolipid lamellar hydrogel as a common probe, we couple data obtained from ice-templated-resolved in situ synchrotron small-angle X-ray scattering (SAXS) with data obtained from controlled adiabatic desiccation experiments. We estimate the pressure to vary between 1 ± 10% kbar at -15 °C and 3.5 ± 20% kbar at -60 °C.

Extracellular matrices (ECM) rich in type I collagen exhibit characteristic anisotropic ultrastructures. Nevertheless, working in vitro with this biomacromolecule remains challenging. When processed, denaturation of the collagen molecule is easily induced in vitro avoiding proper fibril self-assembly and further hierarchical order. Here, an innovative approach enables the production of highly concentrated injectable collagen microparticles, based on collagen molecules self-assembly, thanks to the use of spray-drying process. The versatility of the process is shown by performing encapsulation of secretion products of gingival mesenchymal stem cells (gMSCs), which are chosen as a bioactive therapeutic product for their potential efficiency in stimulating the regeneration of a damaged ECM. The injection of collagen microparticles in a cell culture medium results in a locally organized fibrillar matrix. The efficiency of this approach for making easily handleable collagen microparticles for encapsulation and injection opens perspectives in active tissue regeneration and 3D bioprinted scaffolds., (© 2019 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Type I collagen is the main component of the extracellular matrix (ECM). In vitro, under a narrow window of physicochemical conditions, type I collagen self-assembles to form complex supramolecular architectures reminiscent of those found in native ECM. Presently, a major challenge in collagen-based biomaterials is to couple the delicate collagen fibrillogenesis events with a controlled shaping process in non-denaturating conditions. In this work, an ice-templating approach promoting the structuration of collagen into macroporous monoliths is used. Instead of common solvent removal procedures, a new topotactic conversion approach yielding self-assembled ordered fibrous materials is implemented. These collagen-only, non-cross-linked scaffolds exhibit uncommon mechanical properties in the wet state, with a Young's modulus of 33 ± 12 kPa, an ultimate tensile stress of 33 ± 6 kPa, and a strain at failure of 105 ± 28%. With the help of the ice-patterned microridge features, normal human dermal fibroblasts and C2C12 murine myoblasts successfully migrate and form highly aligned populations within the resulting three-dimensional (3D) collagen scaffolds. These results open a new pathway to the development of new tissue engineering scaffolds ordered across various organization levels from the molecule to the macropore and are of particular interest for biomedical applications where large-scale 3D cell alignment is needed such as for muscular or nerve reconstruction.

Although there is a consensus among conservation biologists about the importance of genetic information, the assessment of extinction risk and conservation decision-making generally do not explicitly consider this type of data. Genetic data can be even more important in species where little other information is available. In this study, we investigated a poorly known legume tree, Dimorphandra exaltata, from the Brazilian Atlantic Forest, a hotspot for conservation. We coupled species distribution models and geospatial assessment based on herbarium records with population genetic analyses to evaluate its genetic status and extinction risk, and to suggest conservation measures. Dimorphandra exaltata shows low genetic diversity, inbreeding, and genetic evidence of decrease in population size, indicating that the species is genetically depleted. Geospatial assessment classified the species as Endangered. Species distribution models projected a decrease in range size in the near future (2050). The genetic status of the species suggests low adaptive potential, which compromises its chances of survival in the face of ongoing climatic change. Altogether, our coupled analyses show that the species is even more threatened than indicated by geospatial analyses alone. Thus, conservation measures that take into account genetic data and the impacts of climate change in the species should be implemented.

Objectives: To evaluate the relationship between drug interactions and QT-interval prolongation in patients admitted to a general intensive care unit (ICU)., Methods: This study was approved by the Institutional Review Board and written informed consent was obtained from all patients. From May 2015 to July 2016, all patients over 18 years-old admitted to the ICU for more than 24 h and in whom the QT-interval on the ECG could be read were prospectively included in this observational, cross-sectional study. All medications administered in the 24 h prior to admission were recorded and the QT-interval was measured upon ICU admission and corrected with Bazzet's formula (QTc). Drug-drug interactions involving drugs potentially associated with QTc prolongation (DDIQT) were searched and QTc increase associated with pharmacokinetic (PK-DDIQT) and pharmacodynamic (PD-DDIQT) interactions was assessed with multiple regression adjusted by patient varibles., Results: The study population consisted of 283 patients, 54.4% males, mean age 57.6 ± 16.7 years-old. Forty five (15.9%) patients presented 65 DDIQT with predominance of pharmacodynamic (66.1%). The risk of DDIQT prescription increased with lower systolic blood pressure, in hypokalemia, in non-diabetics and with the number of medications. PK-DDIQT alone did not affect the QTc interval (7.75 ms, 95%CI: -22.4 to 37.9 ms, p = 0.61), but PD-DDIQT increased QTc by 28.4 ms (95%CI: 9.67 to 47.4 ms, p = 0.003). Most PD-DDIQT involved metoclopramide with ondansetron or amiodarone, and ondansetron with ciprofloxacin., Conclusions: In patients exposed to drugs associated with prolonged QTc in the 24 h prior to ICU admission, pharmacodynamic DDIQT are associated with increased risk of QTc prolongation.

Purpose: To investigate the prevalence and risk factors of acquired long QT syndrome (LQTS) on admission to a general Intensive Care Unit (ICU), and to assess the risk of LQTS associated with prescribed medications., Methods: Prospective observational, cross-sectional study approved by the Institutional Review Board. Between May 2014 and July 2016, 412 patients >18 years-old consecutively admitted to the ICU of a university hospital were included. LQTS was defined as a QT interval on the admission electrocardiogram corrected using Bazett's formula (QTc) >460 ms for men and >470 ms for women. All medications administered within 24 hours before admission were recorded. Logistic regression was used., Results: LQTS prevalence was 27.9%. In LQTS patients, 70.4% had ≥ 1 LQTS-inducing drug prescribed in the 24 hours prior to ICU admission versus 70.4% in non-LQTS patients (p = 0.99). Bradycardia and Charlson morbidity index score are independent risk factors for LQTS. Haloperidol (OR 4.416), amiodarone (OR 2.509) and furosemide (OR 1.895) were associated with LQTS, as well as another drug not yet described, namely clopidogrel (OR 2.241)., Conclusions: The LQTS is highly prevalent in critically ill patients, ICU patients are often admitted with LQTS-inducing medications, and patients with slow heart rate or with high Charlson comorbidity index should be evaluated for LQTS., Competing Interests: The authors have declared that no competing interests exist.