Local E-rhBMP-2/ß-TCP Application Rescues Osteocyte Dendritic Integrity and Reduces Microstructural Damage in Alveolar Bone Post-Extraction in MRONJ-like Mouse Model.

The pathology of medication-related osteonecrosis of the jaw (MRONJ), often associated with antiresorptive therapy, is still not fully understood. Osteocyte networks are known to play a critical role in maintaining bone homeostasis and repair, but the exact condition of these networks in MRONJ is unknown. On the other hand, the local application of E-coli-derived Recombinant Human Bone Morphogenetic Protein 2/ß-Tricalcium phosphate (E-rhBMP-2/ß-TCP) has been shown to promote bone regeneration and mitigate osteonecrosis in MRONJ-like mouse models, indicating its potential therapeutic application for the treatment of MRONJ. However, the detailed effect of BMP-2 treatment on restoring bone integrity, including its osteocyte network, in an MRONJ condition remains unclear. Therefore, in the present study, by applying a scanning electron microscope (SEM) analysis and a 3D osteocyte network reconstruction workflow on the alveolar bone surrounding the tooth extraction socket of an MRONJ-like mouse model, we examined the effectiveness of BMP-2/ß-TCP therapy on the alleviation of MRONJ-related bone necrosis with a particular focus on the osteocyte network and alveolar bone microstructure (microcrack accumulation). The 3D osteocyte dendritic analysis showed a significant decrease in osteocyte dendritic parameters along with a delay in bone remodeling in the MRONJ group compared to the healthy counterpart. The SEM analysis also revealed a notable increase in the number of microcracks in the alveolar bone surface in the MRONJ group compared to the healthy group. In contrast, all of those parameters were restored in the E-rhBMP-2/ß-TCP-treated group to levels that were almost similar to those in the healthy group. In summary, our study reveals that MRONJ induces osteocyte network degradation and microcrack accumulation, while application of E-rhBMP-2/ß-TCP can restore a compromised osteocyte network and abrogate microcrack accumulation in MRONJ.

Constructing Carbon Nanotube Hybrid Fiber Electrodes with Unique Hierarchical Microcrack Structure for High-Voltage, Ultrahigh-Rate, and Ultralong-Life Flexible Aqueous Zinc Batteries.

Flexible aqueous zinc batteries are promising candidates as safe power sources for fast-growing portable and wearable electronics. However, the low working voltage, poor rate capability, and cycling stability have greatly restricted their development and applications. Here, a new family of flexible bimetallic phosphide/carbon nanotube hybrid fiber electrodes with unique macroscopic microcrack structure and microscopic porous nanoflower structure is reported. The hierarchical microcrack structure not only facilitates the penetration of electrolyte for effective exposure of active sites, but also can serve as buffers to relieve the stress concentrations of the fiber electrode under deformations, enabling impressive electrochemical performance and mechanical flexibility. Particularly, the fabricated flexible aqueous zinc batteries demonstrate high working voltage plateau and specific capacity (≈1.7 V, 258.9 mAh g-1 at 2 A g-1 ), ultrahigh rate capability (135.8 mAh g-1 at 50 A g-1 , fully charged in only 9.8 s) and impressive power density of 79 000 W kg-1 . Moreover, the flexible batteries show ultralong cycling life with 74.6% capacity retention after 20 000 cycles. The fiber batteries are also highly flexible and can be easily knitted into soft electronic textiles to power a smartphone, which are particularly promising for the next-generation of flexible and wearable electronics.

Use of bacterial binder in repair mortar for micro-crack remediation.

Micro-cracks are one of the types of stone deterioration which can propagate and lead to surface detachments and larger cracks in the long run. The present study developed a sustainable and environmentally friendly infill material-biological mortar (BM), as an alternative to conventional approaches. Using a biomineralization approach, this BM was explicitly designed for healing micro-cracks (less than 2 mm) in historic travertines. To this end, the mortar was prepared using a calcifying Bacillus sp. isolated from thermal spring water resources in Pamukkale Travertines (Denizli), stone powder gathered from travertine quarries in the vicinity, and a triggering solution specifically designed to set off calcium carbonate precipitation reaction. After setup, BM was applied to micro-cracks of artificially aged test stones for testing. Scanning electron microscopy revealed calcium carbonate-coated Bacillus sp. bodies in the BM matrix, optical microscopy showed secondary calcite minerals throughout the BM applied micro-cracks, and stereomicroscopy and nanoindentation analyses demonstrated bonding of BM with stone due to microbial calcification activities. Furthermore, BM and original material contact showed a continuous and coherent structure in all samples. Within this context, BM could be considered a promising and alternative approach for the remediation of micro-cracks of historic stones. KEY POINTS: A binder was produced by the MICP of Bacillus sp. Pamukkale. Physical, mineralogical, and nanomechanical characterization demonstrated microbial calcite precipitates in BM. A significant bond was determined between the grains and matrix of BM due to Bacillus sp. calcite production activities.

Crack Detecting Method Based on Grid-Type Sensing Networks Using Electrical Signals.

Cracks have a primary effect on the failure of a structure. Therefore, the development of crack sensors with high accuracy and resolution and cracks detection method are important. In this study, the crack sensors were fabricated, and the crack locations were detected with the electrical signal of the crack sensor. First, a metal grid-type micro-crack sensor based on silver was fabricated. The sensor is made with electrohydrodynamics (EHD) inkjet printing technology, which is well known as the next generation of printed electronics technology. Optimal printing conditions were established through experiments, and a grid sensor was obtained. After that, single cracks and multiple cracks were simulated on the sensor, and electrical signals generated from the sensor were measured. The measured electrical signal tracked the location of the cracks in three steps: simple cross-calculation, interpolation, and modified P-SPICE. It was confirmed that cracks could be effectively found and displayed using the method presented in this paper.

Reconfigurable Laser-Stimulated Lock-In Thermography for Surface Micro-Crack Detection.

Surface crack detection and sizing is essential for the manufacturing and maintenance of engines, run parts, and other metal elements of aircrafts. Among various non-destructive detection methods, the fully non-contact and non-intrusive technique based on laser-stimulated lock-in thermography (LLT) has recently attracted a lot of attention from the aerospace industry. We propose and demonstrate a system of reconfigurable LLT for three-dimensional surface crack detection in metal alloys. For large area inspection, the multi-spot LLT can speed up the inspection time by a factor of the number of spots. The minimum resolved size of micro-holes is ~50 µm in diameter limited by the magnification of the camera lens. We also study the crack length ranging from 0.8 to 3.4 mm by varying the modulation frequency of LLT. An empirical parameter related to the thermal diffusion length is found to show the linear dependence with the crack length. With the proper calibration, this parameter can be used to predict the sizing of the surface fatigue cracks. Reconfigurable LLT allows us to quickly locate the crack position and accurately measure its dimensions. This method is also applicable to the non-destructive detection of surface or sub-surface defect in other materials used in various industries.

An Improved Mask R-CNN Micro-Crack Detection Model for the Surface of Metal Structural Parts.

Micro-crack detection is an essential task in critical equipment health monitoring. Accurate and timely detection of micro-cracks can ensure the healthy and stable service of equipment. Aiming at improving the low accuracy of the conventional target detection model during the task of detecting micro-cracks on the surface of metal structural parts, this paper built a micro-cracks dataset and explored a detection performance optimization method based on Mask R-CNN. Firstly, we improved the original FPN structure, adding a bottom-up feature fusion path to enhance the information utilization rate of the underlying feature layer. Secondly, we added the methods of deformable convolution kernel and attention mechanism to ResNet, which can improve the efficiency of feature extraction. Lastly, we modified the original loss function to optimize the network training effect and model convergence rate. The ablation comparison experiments shows that all the improvement schemes proposed in this paper have improved the performance of the original Mask R-CNN. The integration of all the improvement schemes can produce the most significant performance improvement effects in recognition, classification, and positioning simultaneously, thus proving the rationality and feasibility of the improved scheme in this paper.

Enhancing the Reversibility of Lithium Cobalt Oxide Phase Transition in Thick Electrode via Low Tortuosity Design.

Lithium cobalt oxide (LCO) is a widely used cathode material for lithium-ion batteries. However, it suffers from irreversible phase transition during cycling because of high cutoff voltage or huge concentration polarization in thick electrode, resulting in deteriorated cyclability. Here, we design a low tortuous LiCoO2 (LCO-LT) electrode by ice-templating method and investigate the reversibility of LCO phase transition. LCO-LT thick electrode shows accelerated lithium-ion transport and reduced concentration polarization, achieving excellent rate capability and homogeneous actual operating voltage. Moreover, LCO-LT thick electrode exhibits a durable phase transition between O2 and H1-3, mitigated volume expansion, and suppressed microcrack formation. LCO-LT electrode (25 mg cm-2) delivers improved capacity retentions of 94.4% after 200 cycles and 93.3% after 150 cycles at cutoff voltages of 4.3 and 4.5 V, respectively. This strategy provides a new concept to improve the reversibility of LCO phase transition in thick electrode by low tortuosity design.

Micro-CT evaluation of the effect of various ScRp instrumentation methods on cement loss, porosity and micro-crack formation.

OBJECTIVES: The purpose of this study was to compare the effectiveness of three different instruments on cement loss, porosity and micro-crack formation, which was not evaluated before, following scaling and root planning (SRP) using micro-computed tomography (micro-CT). METHODS: In this experimental study, 30 single-rooted extracted human teeth were used and divided into three groups. All the teeth were scanned with micro-CT before and after SRP. Group 1: SRP was performed with Gracey curettes, Group 2: SRP was performed by using an ultrasonic device, and Group 3: SRP was performed by using diamond burs. Cement loss from the root surface, porosity, and micro-crack formation in the root dentine were analysed. Micro-CT is used for qualitative and quantitative analysis of samples. The obtained data were analysed statistically (p < 0.05). RESULTS: Minimum cement loss following SRP was detected with ultrasonic scaler (26.98 mm3 ), whereas the highest was created by diamond burs (96.20 mm3 ) (p < 0.05). The total porosity values after SRP were 0.278%, 0.334% and 0.252% for Groups 1, 2 and 3, respectively. Although Group 3 had the least porosity values, there was no statistically significant difference between the groups. The highest micro-crack formation was seen in Group 2 and the lowest was in Group 1 with a significant difference (p < 0.05). CONCLUSIONS: More cement loss was observed with diamond burs. Ultrasonic devices appear to be a viable alternative to instrumentation with curettes. However, ultrasonic devices should be used carefully because of micro-crack formation since the micro-crack resulting from instrumentation with hand instruments is the least of all.

Finite Element Models of Osteocytes and Their Load-Induced Activation.

PURPOSE OF REVIEW: Osteocytes are the conductors of bone adaptation and remodelling. Buried inside the calcified matrix, they sense mechanical cues and signal osteoclasts in case of low activity, and osteoblasts when stresses are high. How do osteocytes detect mechanical stress? What physical signal do they perceive? Finite element analysis is a useful tool to address these questions as it allows calculating stresses, strains and fluid flow where they cannot be measured. The purpose of this review is to evaluate the capabilities and challenges of finite element models of bone, in particular the osteocytes and load-induced activation mechanisms. RECENT FINDINGS: High-resolution imaging and increased computational power allow ever more detailed modelling of osteocytes, either in isolation or embedded within the mineralised matrix. Over the years, homogeneous models of bone and osteocytes got replaced by heterogeneous and microstructural models, including, e.g. the lacuno-canalicular network and the cytoskeleton. The lacuno-canalicular network induces strain amplifications and the osteocyte protrusions seem to be stimulated much more than the cell body, both by strain and fluid flow. More realistic cell geometries, like minute constrictions of the canaliculi, increase this effect. Microstructural osteocyte models describe the transduction of external stimuli to the nucleus. Supracellular multiscale models (e.g. of a tunnelling osteon) allow to study differential loading of osteocytes and to distinguish between strain and fluid flow as the pivotal stimulatory cue. In the future, the finite element models may be enhanced by including chemical transport and intercellular communication between osteocytes, osteoclasts and osteoblasts.

Micro-CT evaluation of 'danger zone' and microcrack formation in mesial root canals of primary teeth with single-file rotary and reciprocating systems.

BACKGROUND: Although single-file rotary systems are accepted in the field of paediatric dentistry in terms of providing time advantage, research works continue due to the variable anatomical structure of the root canal. AIM: This study aimed to evaluate rotary systems in different kinematics in terms of microcracks and the shaping of the danger zone in primary molars by micro-CT. DESIGN: The mesial canals of primary molars (n = 30) were used. Root canals in each group (n = 10) were prepared with single-file rotary systems (One Shape®, OS; XP-endo® Shaper, XP-ES; WaveOne Gold, WOG). The images were evaluated for dentin thickness in the danger zone and microcrack formation. RESULTS: WOG caused the highest dentin reduction in the danger zone area. OS led to significantly less dentin reduction than XP-ES and WOG (P < .05). The XP-ES showed the highest number of microcracks (P < .05). No statistically significant difference was found between WOG and OS (P > .05). In all systems, more microcracks were observed in the middle third than coronal and apical. CONCLUSION: Within the limitations of this study, the rotary systems were superior to reciprocating in terms of shaping ability in the danger zone. It is thought that further studies with different systems should be designed considering the anatomical variations and chemical composition of primary teeth.

Vertical Load and Torque during Postspace Preparation and Their Influence on Microcrack Development.

PURPOSE: To investigate, in vitro, the magnitudes of vertical load and torque generated during post space preparation of root canal treated teeth and their influence on microcrack development. MATERIALS AND METHODS: Forty extracted premolars with single canals were decoronated. The roots were prepared using ProTaper Next system (Dentsply Sirona) to X3 file, obturated, and provisionalized. After a 3-week incubation period, the roots were distributed into 2 groups according to the post drill system used (ParaPost fiber post and RelyX fiber post). During post space preparation, the vertical load, torque, and preparation time were recorded. Before and after the post space preparation, the roots were imaged with micro-computed tomography (SkyScan 1172; Bruker micro-CT) to detect new microcracks. The data were analyzed using the Mann-Whitney U-test and chi-square test. RESULTS: In ParaPost and RelyX, the post space was prepared in 48.31 ±25.28 and 47.71 ±13.36 seconds, respectively (p = 0.360). The peak vertical load generated with ParaPost (20.23 ±7.80 N) was significantly lower than that of RelyX (29.43 ±5.82 N) (p = 0.010). The maximum torque attained with ParaPost (1.42 ±0.61 N.cm) was found to be significantly lower than that of RelyX (3.23 ±1.58 N.cm) (p = 0.000). No post drill fracture or visible deformation was noticed throughout the experiment. New microcracks were found in three ParaPost samples only. CONCLUSIONS: The choice of postdrill influenced the loads and torques generated during postspace preparation. The ParaPost system showed favorably lower load and torque values during the postspace preparation compared with the RelyX system.

Reconstructing the Environmental Degradation of Polystyrene by Accelerated Weathering.

The fragmentation of macro- into microplastics (MP) is the main source of MP in the environment. Nevertheless, knowledge about degradation mechanisms, changes in chemical composition, morphology, and residence times is still limited. Here, we present a long-term accelerated weathering study on polystyrene (PS) tensile bars and MP particles using simulated solar radiation and mechanical stress. The degradation process was monitored by gel permeation chromatography (GPC), scanning electron microscopy (SEM), energy-dispersive X-ray (EDX), 13C magic-angle spinning (MAS) NMR spectroscopy, tensile testing, and Monte Carlo simulations. We verified that degradation proceeds in two main stages. Stage I is dominated by photooxidation in a near-surface layer. During stage II, microcrack formation and particle rupturing accelerate the degradation. Depending on the ratio and intensity of the applied stress factors, MP degradation kinetics and lifetimes vary dramatically and an increasing amount of small MP fragments with high proportions of carboxyl, peroxide, and keto groups is continuously released into the environment. The enhanced surface area for adsorbing pollutants and forming biofilms modifies the uptake behavior and interaction with organisms together with potential ecological risks. We expect the proposed two-stage model to be valid for predicting the abiotic degradation of other commodity plastics with a carbon-carbon backbone.

Influence of additional apical enlargement on microcrack formation in root dentine: a micro-computed tomography investigation.

OBJECTIVES: To assess the effect of additional apical enlargement using nickel titanium (NiTi) instruments on the incidence of microcracks using micro-computed tomographic analysis. MATERIALS AND METHODS: Fifty-one premolars with single canals were enlarged to ProTaper Gold (PTG) F2 (25/08) (Dentsply Sirona), ProFile Vortex Blue (VB) 25/06 (Dentsply Tulsa), or WaveOne Gold (WOG) primary (25/07) (Dentsply Sirona) NiTi rotary instruments (n = 17 each). Afterward, additional apical enlargement was performed in each group with its corresponding larger instrument (F3 (30/09), VB 30/06, or WOG Medium (35/06) instruments, respectively). All teeth were imaged with micro-computed tomography before canal enlargement and after initial and additional apical enlargements to detect new microcracks at the apical 5 mm. An Aligned Rank Transform ANOVA was conducted to examine the effects of file type and canal enlargement on the number of new microcracks resulting from enlargement. A Kruskal-Wallis test was run to compare the file types at each canal enlargement stage. RESULTS: A significant main effect (P = 0.026) of canal enlargement on the number of new microcracks was found; the number of apical microcracks found after additional enlargement was significantly greater than baseline (P = 0.021); no significant difference was found between baseline and initial enlargement (P = 0.506) and between initial enlargement and additional enlargement (P = 0.252). The Kruskal-Wallis tests found no difference between file types at baseline (P = 0.348), after initial enlargement (P = 0.369) or additional enlargement (P = 0.133). CONCLUSIONS: Regardless of the instrumentation system used, additional apical enlargement led to the formation of high number of new microcracks. CLINICAL SIGNIFICANCE: The results indicated that additional enlargement induced significant number of apical microcracks.

Laboratory Experiments and Grain Based Discrete Element Numerical Simulations Investigating the Thermo-Mechanical Behaviour of Sandstone.

Thermo-mechanical loading can occur in numerous engineering geological environments, from both natural and anthropogenic sources. Different minerals and micro-defects in rock cause heterogeneity at a grain scale, affecting the mechanical and thermal properties of the material. Changes in strength and stiffness can occur from exposure to elevated temperatures, with the accumulation of localised stresses resulting in thermally induced micro-cracking within the rock. In this study we investigated thermal micro-cracking at a grain scale through both laboratory experiments and their numerical simulations. We performed laboratory triaxial experiments on specimens of fine-grained sandstone at a confining pressure of 5 MPa and room temperature (20 ∘ C ), as well as heating to 50 ∘ C , 75 ∘ C and 100 ∘ C prior to mechanical loading. The laboratory experiments were then replicated using discrete element method simulations. The geometry and granular structure of the sandstone was replicated using a Voronoi tessellation scheme to produce a grain based model. Strength and stiffness properties of the Voronoi contacts were calibrated to the laboratory specimens. Grain scale thermal properties were applied to the grain based models according to mineral percentages obtained from quantitative X-ray diffraction analysis on laboratory specimens. Thermo-mechanically coupled modelling was then undertaken to reproduce the thermal loading rates used in the laboratory, before applying a mechanical load in the models until failure. Laboratory results show a reduction of up to 15% peak strength with increasing thermal loading between room temperature and 100 ∘ C , and micro-structural analysis shows the development of thermally induced micro-cracking in laboratory specimens. The mechanical numerical simulations calibrate well with the laboratory results, and introducing coupled thermal loading to the simulations shows the development of localised stresses within the models, leading to the formation of thermally induced micro-cracks and strength reduction upon mechanical loading.

Microcomputed tomography assessment of microcracks following temporary filling placement.

OBJECTIVES: The aim of this study was to detect microcracks and cuspal deflection in tooth crown following the application of temporary filling using microcomputed tomography (micro-CT). MATERIALS AND METHODS: A mesio-occluso-distal cavity preparation was performed, followed by endodontic access cavity preparation and root canal shaping. Cavities were classified into two groups according to the type of temporary filling material used; Coltosol F (Coltene Whaledent) (Group I) and intermediate restorative material (IRM; Dentsply Sirona) (Group II). Micro-CT images before and after temporary filling material placement were obtained and then compared for the presence of microcracks. Microcracks considered in our data analysis were the new ones that were detected after temporary filling material placement. The mean number of new microcracks per tooth recorded for both groups were compared using Mann-Whitney U test. The number of teeth with new microcracks in both groups was compared by chi-square test. Repeated measures t test was conducted to observe the effect of temporary filling on the intercuspal distance (ICD). Also, the mean difference in the ICDs detected after temporary filling placement in both groups were compared by independent t test. The significance level was set at 5%. RESULTS: Eleven microcracks were detected in group I, whereas only three microcracks were observed in group II (p < 0.01). The mean numbers of new microcracks were 0.84 and 0.21 in group I and II, respectively (p < 0.01). There was no significant difference in the ICDs in group I (0.006±0.02 mm) and group II (0.018 ± 0.03 mm) (p > 0.26). Most of the microcracks were found in the dentin structure. The cavity's box area was more affected by new microcracks, compared with the cavity's coronal area. The new microcracks were mainly observed in the mesiodistal direction. No complete fractures were reported in our study. CONCLUSIONS: Both temporary fillings induced microcracks; Coltosol F can induce more microcracks than IRM in premolar teeth after 1-week storage. Most of the microcracks were observed in the dentin structure of the cavity's box area running mesiodistally. CLINICAL RELEVANCE: The results indicated that the tested temporary fillings developed microcracks on the tooth crown with slight deflection of the cusps.

Self-Healing Properties of Bioinspired Amorphous CaCO3/Polyphosphate-Supplemented Cement.

There is a strong interest in cement additives that are able to prevent or mitigate the adverse effects of cracks in concrete that cause corrosion of the reinforcement. Inorganic polyphosphate (polyP), a natural polymer that is synthesized by bacteria, even those on cement/concrete, can increase the resistance of concrete to progressive damage from micro-cracking. Here we use a novel bioinspired strategy based on polyP-stabilized amorphous calcium carbonate (ACC) to give this material self-healing properties. Portland cement was supplemented with ACC nanoparticles which were stabilized with 10% (w/w) Na-polyP. Embedding these particles in the hydrated cement resulted in the formation of calcite crystals after a hardening time of 10 days, which were not seen in controls, indicating that the particles dissolve and then transform into calcite. While there was no significant repair in the controls without ACC, almost complete closure of the cracks was observed after a 10 days healing period in the ACC-supplemented samples. Nanoindentation measurements on the self-healed crack surfaces showed a similar or slightly higher elasticity at a lower hardness compared to non-cracked surfaces. Our results demonstrate that bioinspired approaches, like the use of polyP-stabilized ACC shown here, can significantly improve the repair capacity of Portland cement.

Comparative Evaluation of Microcrack Formation in Different Kinematics Using Rotary and Reciprocating File Systems: An In Vitro Study.

AIM AND OBJECTIVE: To compare r oot microcrack formation after r oot canal preparation using ProTaper Next in r otation or forward r eciprocation and Waveone gold in r everse r eciprocating motion. MATERIALS AND METHODS: Buccal r oots of 60 maxillary premolars with mature apices were selected, for different instrumentation techniques and divided into three groups. Coronal access was achieved and the canals were confirmed for apical patency. The canals were then instrumented using the following instrumentation techniques: ProTaper Next in r otation or forward r eciprocation or Waveone gold in r everse reciprocation. The tooth was then subjected to sectioning using a diamond saw under water cooling and then was visualized under the stereomicroscope for dentinal microcrack. RESULTS: The results showed that the maximum dentinal microcrack formed at apical 3 and 6 mm was in Waveone gold in reverse reciprocation followed by ProTaper Next in forward reciprocation and rotation. However, the p value was found to be not significant at 3 and 6 mm (p value-0.082 and 0.23). CONCLUSION: Nickle titanium rotary instruments tend to induce varied degrees of root dentinal damage during canal instrumentation. ProTaper Next files in rotation as well as forward reciprocation presented with minimal microcrack defects when compared with Waveone gold. CLINICAL SIGNIFICANCE: Root canal preparation, when performed by manual or engine-driven techniques, has shown to produce structural defects in the root dentin. One of the causes of failures in root canal treatment is because of fracture in the dentin that occurs due to these procedures. Though all the motion kinematics caused microcracks in this study, it was seen that rotational motion produced the least structural damage to the dentin.

Russeting partially restores apple skin permeability to water vapour.

MAIN CONCLUSION: The higher water loss of russeted fruit results from the higher permeance of the periderm of the russeted skin as compared to that of the intact cuticle and epidermis. Apple fruit surfaces are often in-parallel composites, comprising areas of intact cuticle (atop a healthy epidermis) adjacent to areas covered by periderm (so-called russet). The occurrence of non-russeting and russeting genotypes makes this species an ideal model to study the barrier properties of its composite skin. The objective was to quantify the water vapour permeances of non-russeted ([Formula: see text]) and russeted fruit skins ([Formula: see text]). Rates of water loss from whole fruit ([Formula: see text]) and excised epidermal skin segments (ES) or peridermal skin segments (PS) were quantified gravimetrically. The [Formula: see text] was larger in russeting than in non-russeting genotypes because [Formula: see text] exceeded [Formula: see text] by about twofold. Also, the [Formula: see text] of russeting genotypes was larger than that of non-russeting genotypes. Generally, [Formula: see text] was more variable than [Formula: see text]. These differences were consistent across seasons and genotypes. The lower [Formula: see text] as compared to [Formula: see text] resulted primarily from the higher wax content of the cuticle of the [Formula: see text]. For non-russeted genotypes, the value of [Formula: see text] was significantly related to the permeance determined on the same intact fruit ([Formula: see text]). Close relationships were also found between the [Formula: see text] calculated from [Formula: see text] determined on the same fruit and the measured [Formula: see text]. For russeting genotypes, the [Formula: see text] or [Formula: see text] were not correlated with [Formula: see text]. The [Formula: see text] calculated from [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] (all determined on an individual-fruit basis) was significantly correlated with the measured [Formula: see text]. Our results demonstrate that the periderm permeance exceeds the cuticle permeance and that permeances of non-russeted surfaces of russeting genotypes exceed those of non-russeting genotypes.

Oxygen Vacancy Diffusion and Condensation in Lithium-Ion Battery Cathode Materials.

Oxygen vacancies (OV) are native defects in transition metal (TM) oxides and their presence has a critical effect on the physicochemical properties of the oxide. Metal oxides are commonly used in lithium-ion battery (LIB) cathodes and there is still a lack of understanding of the role of OVs in LIB research field. Here, we report on the behavior of OVs in a single-crystal LIB cathode during the non-equilibrium states of charge and discharge. We found that microcrack evolution in a single crystal occurs due to OV condensation in specific crystallographic orientations generated by the continuous migration of OVs and TM ions. Moreover, understanding the effects of the presence and diffusion of OVs in metal oxides enables the elucidation of most of the conventional mechanisms of capacity fading in LIBs and provides new insights for new electrochemical applications.

Spatial Distribution of Microcracks in Osteoarthritic Femoral Neck: Influence of Osteophytes on Microcrack Formation.

Osteophytes have been suggested to influence the bone mechanical properties. The aim of this study was to compare the microcrack density in osteophytes with that in the other parts of the osteoarthritic femoral neck (FN). The presence of microcracks was investigated in the ultra-distal FN and in the osteophytes in samples obtained during hip arthroplasty in 24 postmenopausal women aged 67 ± 10 years. Furthermore, the 3D microarchitecture and the collagen crosslinks contents were assessed by high-resolution peripheral quantitative computed tomography and high-performance liquid chromatography, respectively. Osteophytes were present in the 24 FN, mainly at the level of the inferior quadrant. Microcracks were present in all FN with an average of 2.8 per sample. All observed microcracks were linear. The microcrack density (Cr.N/BV; #/mm2) was significantly higher in cancellous than in cortical bone (p = 0.004), whereas the microcrack length (Cr.Le, µm) was significantly greater in cortical bone (p = 0.04). The collagen crosslinks ratio pyridinoline/deoxypyridinoline was significantly and negatively correlated with Cr.N/BV in the posterior (r' = - 0.68, p = 0.01) and inferior (r' = - 0.53, p = 0.05) quadrants. Microcracks were observed in seven osteophytes in seven patients. When microcracks were present in the osteophyte area, Cr.N/BV was also significantly higher in the whole FN and in the quadrant of the osteophyte compared to the cases without microcrack in the osteophyte (p < 0.03). In conclusion, in FN from hip osteoarthritis microcracks are present in all FNs but in only 23% of the osteophytes. The microcrack formation was greater and their progression was smaller in the cancellous bone than in the cortex. The spatial distribution of microcracks varied according to the proximity of the osteophyte, and suggests that osteophyte may influence microcrack formation related to changes in local bone quality.