Tuning the Local Environment of Pt Species at CNT@MO2-x (M = Sn and Ce) Heterointerfaces for Boosted Alkaline Hydrogen Evolution.

As the most promising hydrogen evolution reaction (HER) electrocatalysts, platinum (Pt)-based catalysts still struggle with sluggish kinetics and expensive costs in alkaline media. Herein, we accelerate the alkaline hydrogen evolution kinetics by optimizing the local environment of Pt species and metal oxide heterointerfaces. The well-dispersed PtRu bimetallic clusters with adjacent MO2-x (M = Sn and Ce) on carbon nanotubes (PtRu/CNT@MO2-x) are demonstrated to be a potential electrocatalyst for alkaline HER, exhibiting an overpotential of only 75 mV at 100 mA cm-2 in 1 M KOH. The excellent mass activity of 12.3 mA µg-1Pt+Ru and specific activity of 32.0 mA cm-2ECSA at an overpotential of 70 mV are 56 and 64 times higher than those of commercial Pt/C. Experimental and theoretical investigations reveal that the heterointerfaces between Pt clusters and MO2-x can simultaneously promote H2O adsorption and activation, while the modification with Ru further optimizes H adsorption and H2O dissociation energy barriers. Then, the matching kinetics between the accelerated elementary steps achieved superb hydrogen generation in alkaline media. This work provides new insight into catalytic local environment design to simultaneously optimize the elementary steps for obtaining ideal alkaline HER performance.

Mechanism and Solution of Overcharge Effect in Lithium-Sulfur Batteries.

Increasing the sulfur cathode load is an important method for promoting the commercialization of lithium-sulfur batteries. However, there is a common problem of overcharging in high-loading experiments, which is rarely reported. In this work, it is believed that an insulating layer of S8 forms on the current collector surface, hindering electron exchange with polysulfides. Continuous external current input during layer formation can cause irreversible electrode changes and overcharging. The general solution is to provide nucleation centers with adsorption sites to promote the 3D growth of the insulated S8 , thus avoiding overcharging. In this work,  a solution is proposed by providing nucleation centers by gallium nitrate, by regulating the 3D growth of S8 away from the surface of the current collector to avoid overcharging and by improving battery performance.

MiR-141-3p-Functionalized Exosomes Loaded in Dissolvable Microneedle Arrays for Hypertrophic Scar Treatment.

Hypertrophic scar (HS) is a common fibroproliferative disease caused by abnormal wound healing after deep skin injury. However, the existing approaches have unsatisfactory therapeutic effects, which promote the exploration of newer and more effective strategies. MiRNA-modified functional exosomes delivered by dissolvable microneedle arrays (DMNAs) are expected to provide new hope for HS treatment. In this study, a miRNA, miR-141-3p, which is downregulated in skin scar tissues and in hypertrophic scar fibroblasts (HSFs), is identified. MiR-141-3p mimics inhibit the proliferation, migration, and myofibroblast transdifferentiation of HSFs in vitro by targeting TGF-ß2 to suppress the TGF-ß2/Smad pathway. Subsequently, the engineered exosomes encapsulating miR-141-3p (miR-141-3pOE -Exos) are isolated from adipose-derived mesenchymal stem cells transfected with Lv-miR-141-3p. MiR-141-3pOE -Exos show the same inhibitive effects as miR-141-3p mimics on the pathological behaviors of HSFs in vitro. The DMNAs for sustained release of miR-141-3pOE -Exos are further fabricated in vivo. MiR-141OE -Exos@DMNAs effectively decrease the thickness of HS and improve fibroblast distribution and collagen fiber arrangement, and downregulate the expression of α-SMA, COL-1, FN, TGF-ß2, and p-Smad2/3 in the HS tissue. Overall, a promising, effective, and convenient exosome@DMNA-based miRNA delivery strategy for HS treatment is provided.

Galactinol synthase 2 influences the metabolism of chlorophyll, carotenoids, and ethylene in tomato fruits.

Galactinol synthase (GolS), which catalyses the synthesis of galactinol, is the first critical enzyme in the biosynthesis of raffinose family oligosaccharides (RFOs) and contributes to plant growth and development, and resistance mechanisms. However, its role in fruit development remains largely unknown. In this study, we used CRISPR/Cas9 gene-editing technology in tomato (Solanum lycopersicum) to create the gols2 mutant showing uniformly green fruits without dark-green shoulders, and promoting fruit ripening. Analysis indicated that galactinol was undetectable in the ovaries and fruits of the mutant, and the accumulation of chlorophyll and chloroplast development was suppressed in the fruits. RNA-sequencing analysis showed that genes related to chlorophyll accumulation and chloroplast development were down-regulated, including PROTOCHLOROPHYLLIDE OXIDOREDUCTASE, GOLDEN 2-LIKE 2, and CHLOROPHYLL A/B-BINDING PROTEINS. In addition, early color transformation and ethylene release was prompted in the gols2 lines by regulation of the expression of genes involved in carotenoid and ethylene metabolism (e.g. PHYTOENE SYNTHASE 1, CAROTENE CIS-TRANS ISOMERASE, and 1-AMINOCYCLOPROPANE-1-CARBOXYLIC ACID SYNTHASE2/4) and fruit ripening (e.g. RIPENING INHIBITOR, NON-RIPENING, and APETALA2a). Our results provide evidence for the involvement of GolS2 in pigment and ethylene metabolism of tomato fruits.

Analysis of anatomic location of burns inpatients in China from 2009 to 2018.

BACKGROUND: Burns cause serious physical and psychological harm to patients, placing a heavy burden on the global healthcare system. Our previous study detailed the epidemiological characteristics of burn injuries in Chinese inpatients from 2009 to 2018. Interestingly, the anatomic locations of burn injuries vary by gender, age, provinces, and outcomes among different causes. Therefore, this current study aims to analyze the characteristics of burn injuries in inpatients with various burn sites by collecting data in China from 2009 to 2018. This analysis will inform future healthcare system decisions and provide effective strategies. METHODS: Burns inpatients from 196 hospitals across 31 provinces in China were included in the study, covering the period from 2009 to 2018. The data collected encompassed information on gender, age, etiology, regions, clinical outcomes, and anatomical locations of the injuries. Data analysis was conducted using Microsoft Excel 2007. RESULTS: From 2009 to 2018, a total of 333,995 burns inpatients were recorded. The most vulnerable parts to burns were multiple burn sites (230,090, 68.89%). Women were more susceptible to lower limb burns (15,608, 14%), while men were more prone to eye injuries (8,387, 3.37%) and hand burns (6,119, 2.75%). The age group of 0-10 years was the most vulnerable to burns across all body areas, including internal organs. In China, individuals aged 20-50 years were at a higher risk of head and neck burns compared to other age groups. The Han population showed increased vulnerability to eye injuries (2.12 times higher than minorities), respiratory tract issues (2.09 times higher than minorities), and trunk burns (1.83 times higher than minorities), while being less susceptible to internal organ injuries (0.23 times fewer than minorities) and lower limb burns (0.78 times fewer than minorities). The southwest region had the highest proportion of burns inpatients with burns affecting single body parts, whereas the eastern area had the highest rates of respiratory tract burns (0.85%) and multiple burn sites (80.64%). Scalding was identified as the most common cause of burns, while flame burns (769, 55.81%) and chemical burns (438, 47.35%) were the main causes of respiratory tract and internal organ injuries, respectively. CONCLUSIONS: This study provides an initial description of characteristics of burns inpatients with various anatomic locations of burns in China over the past decade. Our findings will contribute to the most up-to-date clinical evidence database for healthcare planning and prevention initiatives in both China and other countries.

A feasibility study to predict 3D dose delivery accuracy for IMRT using DenseNet with log files.

OBJECTIVE: This study aims to explore the feasibility of DenseNet in the establishment of a three-dimensional (3D) gamma prediction model of IMRT based on the actual parameters recorded in the log files during delivery. METHODS: A total of 55 IMRT plans (including 367 fields) were randomly selected. The gamma analysis was performed using gamma criteria of 3% /3 mm (Dose Difference/Distance to Agreement), 3% /2 mm, 2% /3 mm, and 2% /2 mm with a 10% dose threshold. In addition, the log files that recorded the gantry angle, monitor units (MU), multi-leaf collimator (MLC), and jaws position during delivery were collected. These log files were then converted to MU-weighted fluence maps as the input of DenseNet, gamma passing rates (GPRs) under four different gamma criteria as the output, and mean square errors (MSEs) as the loss function of this model. RESULTS: Under different gamma criteria, the accuracy of a 3D GPR prediction model decreased with the implementation of stricter gamma criteria. In the test set, the mean absolute error (MAE) of the prediction model under the gamma criteria of 3% /3 mm, 2% /3 mm, 3% /2 mm, and 2% /2 mm was 1.41, 1.44, 3.29, and 3.54, respectively; the root mean square error (RMSE) was 1.91, 1.85, 4.27, and 4.40, respectively; the Sr was 0.487, 0.554, 0.573, and 0.506, respectively. There was a correlation between predicted and measured GPRs (P < 0.01). Additionally, there was no significant difference in the accuracy between the validation set and the test set. The accuracy in the high GPR group was high, and the MAE in the high GPR group was smaller than that in the low GPR group under four different gamma criteria. CONCLUSIONS: In this study, a 3D GPR prediction model of patient-specific QA using DenseNet was established based on log files. As an auxiliary tool for 3D dose verification in IMRT, this model is expected to improve the accuracy and efficiency of dose validation.

Predicting the error magnitude in patient-specific QA during radiotherapy based on ResNet.

BACKGROUND: The error magnitude is closely related to patient-specific dosimetry and plays an important role in evaluating the delivery of the radiotherapy plan in QA. No previous study has investigated the feasibility of deep learning to predict error magnitude. OBJECTIVE: The purpose of this study was to predict the error magnitude of different delivery error types in radiotherapy based on ResNet. METHODS: A total of 34 chest cancer plans (172 fields) of intensity-modulated radiation therapy (IMRT) from Eclipse were selected, of which 30 plans (151 fields) were used for model training and validation, and 4 plans including 21 fields were used for external testing. The collimator misalignment (COLL), monitor unit variation (MU), random multi-leaf collimator shift (MLCR), and systematic MLC shift (MLCS) were introduced. These dose distributions of portal dose predictions for the original plans were defined as the reference dose distribution (RDD), while those for the error-introduced plans were defined as the error-introduced dose distribution (EDD). Different inputs were used in the ResNet for predicting the error magnitude. RESULTS: In the test set, the accuracy of error type prediction based on the dose difference, gamma distribution, and RDD + EDD was 98.36%, 98.91%, and 100%, respectively; the root mean squared error (RMSE) was 1.45-1.54, 0.58-0.90, 0.32-0.36, and 0.15-0.24; the mean absolute error (MAE) was 1.06-1.18, 0.32-0.78, 0.25-0.27, and 0.11-0.18, respectively, for COLL, MU, MLCR and MLCS. CONCLUSIONS: In this study, error magnitude prediction models with dose difference, gamma distribution, and RDD + EDD are established based on ResNet. The accurate prediction of the error magnitude under different error types can provide reference for error analysis in patient-specific QA.

Strong Acid Enabled Comprehensive Training of Poly (Sodium Acrylate) Hydrogel Networks.

The design of admirable hydrogel networks is of both practical and fundamental importance for diverse applications of hydrogels. Herein a general strategy of acid-assisted training is designed to enable multiple improvements of conventional poly (sodium acrylate) networks for hydrogels. Hydrophobic homogeneous crosslinked poly (sodium acrylate) hydrogels are prepared to verify the strategy. The multiple improvements of poly (sodium acrylate) networks are simply achieved by immersing the hydrogel networks into 4 M H2SO4 solutions. The introduced acids would induce transformation of poly (sodium acrylate) into poly (acrylic acid) at hydrogel surface, which constructs dynamic hydrogen bonding interactions to tighten the network. The acid-containing poly (sodium acrylate) hydrogels newly generate anti-swelling and self-healing performance, and show mechanical improvement. The internal poly (sodium acrylate) of the pristine acid-containing hydrogels is further fully transformed via acid-infiltration after following cyclic stretch/release training to significantly improve the mechanical performance. The Young's modulus, stress, and toughness of the fully-trained hydrogels are 187.6 times, 35.6 times, and 5.4 times enhanced, respectively. The polymeric networks retain isotropic in fully-trained hydrogels to ensure superior stretchability of 8.6. The acid-assisted training performance of the hydrogels can be reversibly recovered by NaOH neutralization. The acid-assisted training strategy here is general for poly (sodium acrylate) hydrogels.

Image-based features in machine learning to identify delivery errors and predict error magnitude for patient-specific IMRT quality assurance.

OBJECTIVE: To identify delivery error type and predict associated error magnitude by image-based features using machine learning (ML). METHODS: In this study, a total of 40 thoracic plans (including 208 beams) were selected, and four error types with different magnitudes were introduced into the original plans, including 1) collimator misalignment (COLL), 2) monitor unit (MU) variation, 3) systematic multileaf collimator misalignment (MLCS), and 4) random MLC misalignment (MLCR). These dose distributions of portal dose predictions for the original plans were defined as the reference dose distributions (RDD), while those for the error-introduced plans were defined as the error-introduced dose distributions (EDD). Both distributions were calculated for all beams with portal dose image prediction (PDIP). Besides, 14 image-based features were extracted from RDD and EDD of portal dose predictions to obtain the feature vectors. In addition, a random forest was adopted for the multiclass classification task, and regression prediction for error magnitude. RESULTS: The top five features extracted with the highest weight included 1) the relative displacement in the x direction, 2) the ratio of the absolute minimum residual error to the maximal RDD value, 3) the product of the maximum and minimum residuals, 4) the ratio of the absolute maximum residual error to the maximal RDD value, and 5) the ratio of the absolute mean residual value to the maximal RDD value. The relative displacement in the x direction had the highest weight. The overall accuracy of the five-class classification model was 99.85% for the validation set and 99.30% for the testing set. This model could be applied to the classification of the error-free plan, COLL, MU, MLCS, and MLCR with an accuracy of 100%, 98.4%, 99.9%, 98.0%, and 98.3%, respectively. MLCR had the worst performance in error magnitude prediction (70.1-96.6%), while others had better performance in error magnitude prediction (higher than 93%). In the error magnitude prediction, the mean absolute error (MAE) between predicted error magnitude and actual error ranged from 0.03 to 0.33, with the root mean squared error (RMSE) varying from 0.17 to 0.56 for the validation set. The MAE and RMSE ranged from 0.03 to 0.50 and 0.44 to 0.59 for the test set, respectively. CONCLUSION: It could be demonstrated in this study that the image-based features extracted from RDD and EDD can be employed to identify different types of delivery errors and accurately predict error magnitude with the assistance of ML techniques. They can be used to associate traditional gamma analysis with clinically based analysis for error classification and magnitude prediction in patient-specific IMRT quality assurance.

Photobiomodulation promotes hair regeneration in injured skin by enhancing migration and exosome secretion of dermal papilla cells.

The application of photobiomodulation (PBM) in regenerative medicine has expanded to the treatment of alopecia caused by various reasons. However, the mechanisms responsible for its effects are poorly understood. Here, we aimed to investigate the effects of PBM on hair regeneration in injured skin and to explore the underlying mechanisms. The scratched epidermis or dermis models were established in C57 mice aged 7-8 weeks. We found that the scratched epidermis had no influence on hair regeneration, but the scratched dermis led to obvious hair follicle atrophy and significantly influenced hair regeneration. The wounds in scratched dermis models were treated with PBM (655 nm, 3 J/cm2 [10 min]) and the hair regeneration and cell proliferation in hair follicle were evaluated. Compared with control, the hair coverage level was significantly enhanced after PBM treatment. Sox9+ and PCNA+ cells in hair follicle were obviously observed in PBM-treated group, but not in control. In vitro, the effects of PBM on the function of dermal papilla cells (DPCs) were investigated. The results showed that the migration of DPCs was increased significantly by PBM (655 nm, 3 J/cm2 [10 min]), whereas no effect was found on proliferation. Furthermore, we found that PBM promoted exosome secretion of DPCs, accompanied by the activation of Akt/GSK-3ß/ß-catenin pathway. AKT inhibitor MK-2206 effectively blocked PBM-induced migration and exosome secretion of DPCs. These findings suggest that the enhanced migration and exosome secretion of DPCs mediated by the Akt/GSK-3ß/ß-catenin pathway were responsible for the promotion of hair regeneration in injured skin by PBM.

Photobiomodulation Therapy With Different Wavebands for Hair Loss: A Systematic Review and Meta-Analysis.

BACKGROUND: Photobiomodulation is a promising therapy for hair loss with negligible side effects. However, the reported effects of photobiomodulation therapy for hair loss are inconsistent. OBJECTIVE: To assess the curative effect of photobiomodulation therapy for the treatment of hair loss. METHODS: A systematic review of self-controlled studies and randomized controlled trials was conducted. ScienceDirect, PubMed, and Wiley Online Library were searched from the earliest date to May 30, 2021. RESULTS: Thirty-six studies (966 patients) were included. Two to 4 meta-analyses with different indices were performed separately on 4 groups of studies to test the effectiveness of the following hair loss treatments: ultraviolet light for alopecia areata (AA), red light for androgenetic alopecia (AGA), infrared light for AA, and infrared light for AGA. All meta-analyses showed that treatments were superior to control ( p < .05). CONCLUSION: The meta-analyses strongly suggested that photobiomodulation therapies with ultraviolet and infrared light were effective for treating AA, and photobiomodulation therapies with red light and infrared light were effective for treating AGA.

A novel CRT-IMRT-combined (Co-CRIM) planning technique for peripheral lung stereotactic body radiotherapy in pinnacle treatment planning system.

OBJECTIVES: This study attempts to explore a novel peripheral lung stereotactic body radiotherapy (SBRT) planning technique that can balance the pros and cons of three-dimensional conformal radiotherapy (CRT) and intensity-modulated radiation therapy (IMRT) / volumetric modulated arc therapy (VMAT). METHODS: Treatment plans were retrospectively designed based on CRT, IMRT, VMAT, and the proposed CRT-IMRT-combined (Co-CRIM) techniques using Pinnacle treatment planning system (TPS) for 20 peripheral lung cancer patients. Co-CRIM used an inverse optimization algorithm available in Pinnacle TPS. To develop a Co-CRIM plan, the number of segments in each field was limited to one, the minimum segment area was set to the internal target volume (ITV), and the minimum monitor units (MU) of the segment was the quotient of fractional dose divided by twice the number of total fields. The performance of Co-CRIM was then compared with other techniques. RESULTS: For conformity index (CI), Co-CRIM performed comparably to IMRT/VMAT but better than CRT. For gradient index (GI), Co-CRIM was similar to IMRT/VMAT or CRT. For heterogeneity index (HI), Co-CRIM was comparable to IMRT/VMAT, higher than CRT. The dosimetric results of spinal cord and lung with Co-CRIM were better than CRT, comparable to IMRT, but inferior to VMAT. The MU resulted from Co-CRIM was lower than IMRT/VMAT but higher than CRT. For plan verification γ passing rate, Co-CRIM was higher than IMRT/VMAT, comparable to CRT. For planning time, Co-CRIM was shorter than CRT or VMAT but similar to IMRT. CONCLUSIONS: The proposed Co-CRIM technique on Pinnacle TPS is an effective planning technique for peripheral lung SBRT.

Akermanite bioceramic enhances wound healing with accelerated reepithelialization by promoting proliferation, migration, and stemness of epidermal cells.

Reepithelialization is an important step of wound healing, which is mainly completed by proliferation and migration of epidermal cells. Akermanite is a Ca-, Mg-, and Si-containing bioceramic. This study evaluated the effects of Akermanite on wound healing and investigated the mechanisms. Using scald burn mice models, we demonstrated that local Akermanite treatment significantly accelerated wound healing by increasing reepithelialization and the stemness of epidermal cells. Epidermal cells were cultured in medium containing Akermanite extracts to explore the cellular mechanism of reepithelialization. Akermanite promoted the cell proliferation and migration, maintaining more cells in the S and G2 /M phases of the cell cycle. An additional study showed that Akermanite enhanced the expressions of integrinß1, Lgr4, Lgr5, and Lgr6, which are specific molecular markers of epidermal stem cells, accompanied by the activation of the Wnt/ß-catenin pathway. These results suggested that Akermanite accelerated reepithelialization by increasing the proliferation, migration, and stemness of epidermal cells in a manner related to the Wnt/ß-catenin pathway, which might contribute, at least partially, to accelerated wound healing by Akermanite therapy.

Regenerative and protective effects of calcium silicate on senescent fibroblasts induced by high glucose.

Diabetic wounds are a common complication of diabetes and therefore a pressing issue for clinicians. High-glucose (HG)-induced fibroblast senescence is mainly responsible for delayed wound healing. Calcium silicate (CS), a kind of bioceramic, is thought to have regenerative properties. The aim of this study was to determine the regenerative and protective effects of CS on senescent fibroblasts induced by HG. Fibroblasts were passaged five times and treated with HG and CS. Compared with the normal glucose (NG) group, the proliferation, migration, and differentiation capacity of HG-induced fibroblasts significantly decreased (P < .05). After treatment with CS, the functions of HG-induced senescent fibroblasts were partly restored (P < .05). The mechanism of the regenerative and protective effects of CS may be related to the decreased reactive oxygen species generation, improved senescent state (SA-ß-gal expression decreased), up-regulated expression of Smad2 and phosphorylated Smad2, and down-regulated expression of p16, p21, and p53. An in vivo experiment also demonstrated that CS had a therapeutic effect on diabetic wounds via differentiation of fibroblasts into myofibroblasts and enhanced collagen deposition. These results indicate that CS may be a promising candidate for diabetic wound therapy.

Household Transmission of Human Adenovirus Type 55 in Case of Fatal Acute Respiratory Disease.

We identified a case of fatal acute respiratory disease from household transmission of human adenovirus type 55 (HAdV-55) in Anhui Province, China. Computed tomography showed severe pneumonia. Comparative genomic analysis of HAdV-55 indicated the virus possibly originated in Shanxi Province, China. More attention should be paid to highly contagious HAdV-55.

The Effect of Chyle Fat Injection on Human Hypertrophic Scars in an Animal Model: A New Strategy for the Treatment of Hypertrophic Scars.

BACKGROUND: Chyle fat transplantation has shown positive effects on preexisting human hypertrophic scars (HSs) in a nude mouse HS graft model. METHODS: Hypertrophic scar fragments were obtained from 5 surgically treated burn patients and implanted into the backs of nude mice in 3 groups: group A, control; group B, triamcinolone; and group C, chyle fat. The specimens were implanted after the corresponding intralesional injection in each group, and the mice were observed for 4 weeks. In total, 18 mice and 72 scar specimens were studied. After 4 weeks, the HSs were removed from the mice. Then, the scar weights, histology, and decorin staining were assessed to evaluate the therapeutic efficacy. RESULTS: An obviously significant difference was observed in the HS weight reduction between groups A and C (P < 0.01), and a significant difference in the HS weight reduction was observed between groups A and B (P < 0.05). However, there was no significant difference between groups B and C. The treatment groups (groups B and C) showed strong decorin staining. Furthermore, the decorin staining was much stronger in group C than in group B (P < 0.05). Significant differences in extracellular matrix deposition were observed among the 3 groups, as determined by Masson trichrome staining. Both groups B and C showed significant therapeutic efficacy compared with group A, and group C exhibited a significant therapeutic effect compared with group B (P < 0.05). CONCLUSIONS: This study indicates that chyle fat grafting is beneficial for treating HSs.

T2 -Mapping evaluation of early cartilage alteration of talus for chronic lateral ankle instability with isolated anterior talofibular ligament tear or combined with calcaneofibular ligament tear.

PURPOSE: To quantitatively evaluate the cartilage alteration of talus for chronic lateral ankle instability (LAI) with isolated anterior talofibular ligament (ATFL) tear and combined ATFL and calcaneofibular ligament (CFL) tear using T2 -mapping at 3.0T. MATERIALS AND METHODS: In all, 27 patients including 17 with isolated ATFL tear and 10 with ATFL+CFL tear, and 21 healthy subjects were recruited. All participants underwent T2 -mapping scan at 3T and patients completed American Orthopaedic Foot and Ankle Society (AOFAS) scoring. The total talar cartilage (TTC) was segmented into six compartments: medial anterior (MA), medial center (MC), medial posterior (MP), lateral anterior (LA), lateral center (LC), and lateral posterior (LP). The T2 value of each compartment was measured from T2 -mapping images. Data were analyzed with one-way analysis of variance (ANOVA), Student's t-test, and Pearson's correlation coefficient. RESULTS: The T2 values of MA, MC, MP, TTC in the ATFL group and MA, MC, MP, LC, LP, TTC in the ATFL+CFL group were higher than those in the control group (P < 0.05). Moreover, the T2 values of MC, MP, LC, and TTC in the ATFL+CFL group were higher than those in the ATFL group (P < 0.05). The T2 values of MA in both patient groups were negatively correlated with AOFAS scores (r = -0.596, r = -0.690, P < 0.05). CONCLUSION: Chronic LAI with ATFL tear had a trend of increasing cartilage T2 values in talar trochlea, mainly involving medial cartilage compartments. Chronic LAI with ATFL+CFL tear might result in higher T2 values in a much larger cartilage region than with ATFL tear. MA could be the main cartilage compartment that may affect the patient's clinical symptoms. LEVEL OF EVIDENCE: 1 Technical Efficacy: Stage 3 J. Magn. Reson. Imaging 2018;47:69-77.

Bone Marrow-Derived Mesenchymal Stem Cells Promoted Cutaneous Wound Healing by Regulating Keratinocyte Migration via ß2-Adrenergic Receptor Signaling.

Mesenchymal stem cells (MSCs) play an important role in cutaneous wound healing; however, the functional mechanisms involved in the healing process are poorly understood. A series of studies indicate that keratinocytes that migrate into the wound bed rely on an epithelial-mesenchymal transition (EMT)-like process to initiate re-epithelialization. We therefore examined whether bone marrow-derived MSCs (BMSCs) could affect biological behavior and induce EMT-like characteristics in the human epidermal keratinocytes (HEKs) and in the immortalized human keratinocyte cell line HaCaT cells, and we investigated the signaling pathways of BMSC-mediated phenotypic changes. By assessing the expression of EMT-related markers including E-cadherin, α-SMA, and Snail family transcription factors by ß2-adrenergic receptor (ß2-AR) blockage using ICI-118,551, a ß2-AR selective antagonist, or ß2-AR small interfering RNA (siRNA), we showed an involvement of ß2-AR signaling in the induction of EMT-like alterations in human keratinocytes in vitro. ß2-AR signaling also affected collective and individual cell migration in human keratinocyte cell lines, which was attenuated by administration of ICI-118,551. Treating the cells with BMSC-conditioned media (BMSC-CM) not only recapitulated the effect of isoproterenol (ISO) on cell migration but also induced the expression of ß2-AR and a panel of proteins associated with mesenchymal phenotype in HEKs and HaCaT cells. Similarly, a blockade of the ß2-AR by either ICI-118,551 or ß2-AR siRNAs reversed both responses of the epidermal keratinocyte cell lines relative to BMSC-CM exposure. These results were further verified in our vivo findings and indicated that the exogenous application of MSCs promoted cutaneous wound healing and endowed the keratinocytes surrounding the wound area with an increased migratory phenotype through activation of ß2-AR signaling. Our findings suggest a biochemical mechanism underlying the function of MSCs in wound re-epithelization, which provides a reliable theoretical basis for the wide application of MSCs in the treatment of chronic wounds.

Treatment of talus osteochondral defects in chronic lateral unstable ankles: small-sized lateral chondral lesions had good clinical outcomes.

PURPOSE: To assess and compare the clinical and MRI outcomes of patients with talus osteochondral defect (OCD) and patients without OCD in a cohort with chronic lateral ankle instability. METHODS: All patients who underwent open or arthroscopic anterior talofibular ligament repair of the lateral ligament complex by a single surgeon were included in this study. Ankle arthroscopic surgery was initially performed to manage any intra-articular OCD, including debridement and microfracture. Functional scores (AOFAS, Karlsson score) and Tegner activity level scores were determined. An MRI scan was performed at follow-up to assess talus OCD after treatment. Spearman's correlation coefficients were calculated between functional scores and various factors. RESULTS: A total of 104 patients with chronic ankle instability were included in this study. Among them, 33 patients had cartilage injury on the talus (OCD group), and the other 71 patients had no cartilage injury (control group). After surgery, there was a significant increase in the AOFAS scores (p < 0.001), the Karlsson scores (p < 0.001), and the Tegner activity scores (p < 0.001) in both the OCD group and the control group. However, there was no significant difference in the AOFAS scores (90.7 ± 6.6 vs. 92.5 ± 8.5; n.s.), the Karlsson scores (89.7 ± 9.3 vs. 91.2 ± 9.1; n.s.), or the Tegner activity scores (5 vs. 6; n.s.) between the OCD group and the control group postoperatively. In the OCD group, there was a significant negative association between the functional scores (AOFAS, Karlsson score, or Tegner score) and the number of intra-articular lesions. For the lateral OCD, the mean lesion area significantly decreased from 49.0 ± 10.7 mm2 preoperatively to 18.3 ± 13.1 mm2 at the final follow-up (p < 0.001). CONCLUSION: No significant difference in functional outcomes was found between the OCD group and the control group postoperatively. Arthroscopic microfracture is a good option for the long-term treatment of lateral talus OCD. LEVEL OF EVIDENCE: III.

Interference screw insertion angle has no effect on graft fixation strength for insertional Achilles tendon reconstruction.

PURPOSE: To compare the effect of two interference screw insertion angles on the biomechanical properties of the insertional Achilles tendon (IAT) reconstruction. METHODS: Nine matched pairs of fresh-frozen human cadaveric Achilles tendon specimens were randomized to two groups with interference screw insertion angles of 60° and 120°. The IAT reconstruction was performed by fixing the graft tendon with the interference screw. Each specimen was loaded to failure. The load at failure, stiffness, and mode of failure were documented. Differences in load at failure and stiffness were analysed. RESULTS: There was no statistically significant difference between the 60° and 120° groups for failure load (149.137 ± 20.836 versus 155.428 ± 28.343 N, respectively, n.s.) and stiffness (14.523 ± 2.824 N/mm versus 14.727 ± 2.192 N/mm, respectively, n.s.). The most common mode of failure was the graft pulling out of the bone tunnel when the screw broke. CONCLUSIONS: Graft fixation at two different interference screw insertion angles for IAT reconstruction exhibited equivalent biomechanical performance. When performing this procedure, surgeons may choose the interference screw insertion angle based on personal preference.