Prediction of cross-border spread of the COVID-19 pandemic: A predictive model for imported cases outside China.

The COVID-19 pandemic has been present globally for more than three years, and cross-border transmission has played an important role in its spread. Currently, most predictions of COVID-19 spread are limited to a country (or a region), and models for cross-border transmission risk assessment remain lacking. Information on imported COVID-19 cases reported from March 2020 to June 2022 was collected from the National Health Commission of China, and COVID-19 epidemic data of the countries of origin of the imported cases were collected on data websites such as WHO and Our World in Data. It is proposed to establish a prediction model suitable for the prevention and control of overseas importation of COVID-19. Firstly, the SIR model was used to fit the epidemic infection status of the countries where the cases were exported, and most of the r2 values of the fitted curves obtained were above 0.75, which indicated that the SIR model could well fit different countries and the infection status of the region. After fitting the epidemic infection status data of overseas exporting countries, on this basis, a SIR-multiple linear regression overseas import risk prediction combination model was established, which can predict the risk of overseas case importation, and the established overseas import risk model overall P <0.05, the adjusted R2 = 0.7, indicating that the SIR-multivariate linear regression overseas import risk prediction combination model can obtain better prediction results. Our model effectively estimates the risk of imported cases of COVID-19 from abroad.

Revealing microscopic dynamics: in situ liquid-phase TEM for live observations of soft materials and quantitative analysis via deep learning.

In various domains spanning materials synthesis, chemical catalysis, life sciences, and energy materials, in situ transmission electron microscopy (TEM) methods exert a profound influence. These methodologies enable the real-time observation and manipulation of gas-phase and liquid-phase reactions at the nanoscale, facilitating the exploration of pivotal reaction mechanisms. Fundamental research areas like crystal nucleation, growth, etching, and self-assembly have greatly benefited from these techniques. Additionally, their applications extend across diverse fields such as catalysis, batteries, bioimaging, and drug delivery kinetics. However, the intricate nature of 'soft matter' presents a challenge due to the unique molecular properties and dynamic behavior of these substances that remain insufficiently understood. Investigating soft matter within in situ liquid-phase TEM settings demands further exploration and advancement compared to other research domains. This research harnesses the potential of in situ liquid-phase TEM technology while integrating deep learning methodologies to comprehensively analyze the quantitative aspects of soft matter dynamics. This study centers on diverse phenomena, encompassing surfactant molecule nucleation, block copolymer behavior, confinement-driven self-assembly, and drying processes. Furthermore, deep learning techniques are employed to precisely analyze Ostwald ripening and digestive ripening dynamics. The outcomes of this study not only deepen the understanding of soft matter at its fundamental level but also serve as a pivotal foundation for developing innovative functional materials and cutting-edge devices.

Application of Dominant Gut Microbiota Promises to Replace Fecal Microbiota Transplantation as a New Treatment for Alzheimer's Disease.

Several studies have confirmed that the pathophysiological progression of Alzheimer's disease (AD) is closely related to changes in the intestinal microbiota; thus, modifying the intestinal microbiota has emerged as a new way to treat AD. Effective interventions for gut microbiota include the application of probiotics and other measures such as fecal microbiota transplantation (FMT). However, the application of probiotics ignores that the intestine is a complete microecosystem with competition among microorganisms. FMT also has issues when applied to patient treatment. In a previous study, we found that eight species of bacteria that are isolated with high frequency in the normal intestinal microbiota (i.e., intestinal dominant microbiota) have biological activities consistent with the effects of FMT. In this article, we confirmed that the treatment of intestinal dominant microbiota significantly restored intestinal microbiota abundance and composition to normal levels in APP/PS1 mice; downregulated brain tissue pro-inflammatory cytokines (IL-1ß and IL-6) and amyloid precursor protein (APP) and ß-site APP cleavage enzyme 1 (BACE1) expression levels; and reduced the area of Aß plaque deposition in the brain hippocampus. Our study provides a new therapeutic concept for the treatment of AD, adjusting the intestinal microecological balance through dominant intestinal microbiota may be an alternative to FMT.

Effect of chronic diseases on willingness to receive the second COVID-19 vaccine booster dose among cancer patients: A multicenter cross-sectional survey in China.

BACKGROUND: Cancer patients and those with chronic diseases face severe outcomes from SARS-CoV-2 infection. However, their willingness to receive a second booster dose remains low. This study identified factors affecting the willingness of cancer patients with chronic diseases (CPCD) and cancer patients without chronic diseases (non-CPCD) to receive the second COVID-19 booster vaccine dose. METHODS: A multicenter cross-sectional study was conducted across 4 tertiary care hospitals in China. Based on the Health Belief Model, a questionnaire assessed respondents' perceptions of the second booster dose. Multivariable logistic regression analyzed factors influencing the willingness to receive a second vaccine dose. RESULTS: Out of 171 CPCD and 722 non-CPCD, CPCD showed a higher willingness to receive the second booster dose than non-CPCD (46.8% vs 32.3%, P < .001). Factors influencing CPCD's willingness included the belief that vaccination was detrimental to cancer treatment and the perceived higher infection risk compared to healthy individuals. Fear of vaccination's negative impact on cancer treatment was the main factor affecting non-CPCD's willingness (each P < .05). CONCLUSIONS: Different factors influenced the willingness of the 2 groups. Health education interventions should be implemented alongside vaccination, involving patients' relatives and medical staff, for both CPCD and non-CPCD populations. Additionally, health management service interventions should emphasize the benefits of vaccination for CPCD to improve their second dose coverage.

Comparison of the two surgery methods combined with accelerated rehabilitation in the treatment of lateral compression type 1 pelvic fractures in the elderly.

BACKGROUND: Treating lateral compression type 1 (LC1) pelvic ring injuries in older patients is controversial. This study evaluated surgical treatments combined with ERAS for treating LC1 pelvic fractures in the elderly. METHODS: In this retrospective study, patients who underwent surgery with INFIX (supra-acetabular spinal pedicle screws, and a subcutaneous connecting rod; the experimental group) or superior pubic ramus cannulated screw (the control group) fixation of LC1 pelvic fracture from January 2019 to January 2022 were reviewed. Injury radiography and computed tomography were performed to determine the Young-Burgess classification. All patients performed standardized early rehabilitation exercises after surgery and were followed up for > 12 months. After surgery, the Matta score and the visual analog scale (VAS) were evaluated, and the postoperative weight-bearing time and the length of stay (LOS) were recorded. The Barthel index and the Majeed score were evaluated at 4 months after surgery and at the last follow-up. RESULTS: Fifty-three patients were included. Thirty-two patients included in the experimental group had a mean age of 75.0 ± 6.2 (range, 66-86) years, and the other 21 patients in the control group had a mean age of 74.6 ± 4.6 (range, 68-83) years. The mean follow-up time was 13.1 ± 1.6 (range, 12-18) months in the experimental group and 13.4 ± 1.3 (range, 12-16) months in the control group. There were no significant differences in follow-up time between the groups (P > 0.05). The mean VAS score, time to weight-bearing, and LOS were 2.0 ± 0.7 (range, 1-3), 1.1 ± 0.3 (range, 1-2) d, and 5.8 ± 0.9 (range, 4-7) d in the experimental group and 2.3 ± 1.2 (range, 1-5), 2.5 ± 1.6 (range, 1-7) d, and 6.1 ± 1.6 (range, 5-11) d in the control group, respectively. Between the two groups, there was a significant difference in the postoperative time to weight-bearing (P < 0.05), while there was no significant difference in the LOS (P > 0.05). No bedrest-related complications occurred in either group. The Matta score was 90.6% in the experimental group and 90.4% in the control group (P > 0.05). At the 4-months follow-up, the experimental group had a better Barthel index and Majeed score compared with the control group, which were 86.1 ± 6.2 (range, 70-95) vs. 81.2 ± 4.1 (range, 75-90) and 86.3 ± 3.3 (range, 78-91) vs. 80.3 ± 3.9 (range, 76-86), respectively. The experimental group had better early rehabilitation effect than the control group. There was no significant difference in Barthel index and Majeed score between the two groups at the last follow-up (P > 0.05). CONCLUSION: Both INFIX and intramedullary superior pubic ramus cannulated screws can successfully treat LC1 pelvic fractures and reduce bed rest complications among older patients.

Understanding ZIF particle chemical etching dynamics and morphology manipulation: in situ liquid phase electron microscopy and 3D electron tomography application.

In situ liquid phase transmission electron microscopy (TEM) and three-dimensional electron tomography are powerful tools for investigating the growth mechanism of MOFs and understanding the factors that influence their particle morphology. However, their combined application to the study of MOF etching dynamics is limited due to the challenges of the technique such as sample preparation, limited field of view, low electron density, and data analysis complexity. In this research, we present a study employing in situ liquid phase TEM to investigate the etching mechanism of colloidal zeolitic imidazolate framework (ZIF) nanoparticles. The etching process involves two distinct stages, resulting in the development of porous structures as well as partially and fully hollow morphologies. The etching process is induced by exposure to an acid solution, and both in situ and ex situ experiments demonstrate that the outer layer etches faster leading to overall volume shrinking (stage I) while the inner layer etches faster giving a hollow morphology (stage II), although both the outer layer and inner layer have been etched in the whole process. 3D electron tomography was used to quantify the properties of the hollow structures which show that the ZIF-67 crystal etching rate is larger than that of the ZIF-8 crystal at the same pH value. This study provides valuable insights into MOF particle morphology control and can lead to the development of novel MOF-based materials with tailored properties for various applications.

Uptake of Heterologous or Homologous COVID-19 Booster Dose and Related Adverse Events Among Diabetic Patients: A Multicenter Cross-Sectional Study - China, 2022.

What is already known about this topic?: Although a third coronavirus disease 2019 (COVID-19) vaccination (booster) dose is highly recommended for diabetic patients, the vaccination behaviors and related adverse events are unclear among diabetic patients with a COVID-19 booster dose. What is added by this report?: Diabetic patients with higher postprandial blood glucose, worrying about the safety of the booster dose were less likely to get the vaccine. While having positive attitudes towards COVID-19 booster vaccination, trusting the health professionals' advice on vaccination, diabetic patients were more likely to get the booster vaccine. Furthermore, the prevalence of adverse events was not significantly different between the homologous and heterologous boosting groups. What are the implications for public health practice?: Effective measures should be taken to promote the COVID-19 booster dose uptake among diabetic patients. Health professionals should educate Chinese diabetic patients about the safety and efficacy of booster doses and continue to increase the COVID-19 booster dose vaccination coverage.

Accelerated rehabilitation in treating neer type V distal clavicle fractures using anatomical locking plates with coracoclavicular ligament augmentation.

Background: There is still no gold standard treatment for Neer type V distal clavicle fractures. This study was designed to evaluate the therapeutic effects of accelerated rehabilitation in treating Neer type V fractures using anatomical locking plate (ALP) fixation with additional coracoclavicular (CC) ligament augmentation. Methods: In this retrospective study, patients who underwent ALP fixation with additional suture anchor fixation of acute Neer type V distal clavicle fracture from January 2016 to January 2021 were reviewed. Injury radiography and computed tomography (CT) were performed to determine the Neer classification. All patients performed standardized early rehabilitation exercises after surgery and were followed up for more than 12 months. The Constant-Murley score (CMS); the disabilities of the arm, shoulder, and hand (DASH) questionnaire; visual analog scale (VAS); and the percentage of modified CC distance (MCCD%) were evaluated at the last follow-up. Results: Thirty-two patients were included in this study. The mean follow-up time was 31.1 ± 10.4 months. All patients achieved bone union 6-8 weeks (7.2 ± 0.7 weeks) after surgery and were allowed to return to normal daily life. No surgery-related complications occurred in any case. The MCCD% value at the last follow-up (104.7% ± 8.5%) significantly decreased compared with preoperative MCCD% value (162.8% ± 7.2%) (p < 0.001), indicating that all patients achieved ideal fracture reduction. And all patients obtained satisfactory shoulder joint function with a mean CMS of 97.1 ± 2.6, a mean DASH score of 1.6 ± 1.3, and a mean VAS score of 0.4 ± 0.6. Conclusion: This study has demonstrated that ALP fixation with additional suture anchor fixation is a promising strategy for accelerated rehabilitation in treating patients with Neer type V fracture.

High-Resolution Electron Tomography of Ultrathin Boerdijk-Coxeter-Bernal Nanowire Enabled by Superthin Metal Surface Coating.

The rapid advancement of transmission electron microscopy has resulted in revolutions in a variety of fields, including physics, chemistry, and materials science. With single-atom resolution, 3D information of each atom in nanoparticles is revealed, while 4D electron tomography is shown to capture the atomic structural kinetics in metal nanoparticles after phase transformation. Quantitative measurements of physical and chemical properties such as chemical coordination, defects, dislocation, and local strain have been made. However, due to the incompatibility of high dose rate with other ultrathin morphologies, such as nanowires, atomic electron tomography has been primarily limited to quasi-spherical nanoparticles. Herein, the 3D atomic structure of a complex core-shell nanowire composed of an ultrathin Boerdijk-Coxeter-Bernal (BCB) core nanowire and a noble metal thin layer shell deposited on the BCB nanowire surface is discovered. Furthermore, it is demonstrated that a new superthin noble metal layer deposition on an ultrathin BCB nanowire could mitigate electron beam damage using an in situ transmission electron microscope and atomic resolution electron tomography. The colloidal coating method developed for electron tomography can be broadly applied to protect the ultrathin nanomaterials from electron beam damage, benefiting both the advanced material characterizations and enabling fundamental in situ mechanistic studies.

Coronal and sagittal spinopelvic alignment in the patients with unilateral developmental dysplasia of the hip: a prospective study.

BACKGROUND: How the hip dysplasia affects the spinopelvic alignment in developmental dysplasia of the hip (DDH) patients is unclear, but it is an essential part for the management of this disease. This study aimed to investigate the coronal and sagittal spinopelvic alignment and the correlations between the spinopelvic parameters and the extent of hip dysplasia or the low back pain in unilateral DDH patients. METHODS: From September 2016 to March 2021, 22 unilateral patients were enrolled in the DDH group with an average age of 43.6 years and 20 recruited healthy volunteers were assigned to the control group with an average age of 41.4 years. The Cobb angle, seventh cervical vertebra plumbline-central sacral vertical line (C7PL-CSVL), third lumbar vertebra inclination angle (L3IA), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), thoracic kyphosis (TK), thoracolumbar kyphosis (TLK) and lumbar lordosis (LL) were measured on the standing anteroposterior and lateral full-length standing spine radiographs. Additionally, the Oswestry Disability Index (ODI) and Japanese Orthopaedic Association Back Pain Evaluation Questionnaire (JOABPEQ) were used to assess the degree of low back pain. RESULTS: Cobb angle (8.68 ± 6.21° vs. 2.31 ± 0.12°), L3IA (4.80 ± 5.47° vs. 0.83 ± 0.51°), C7PL-CSVL (1.65 ± 1.57 cm vs. 0.48 ± 0.33 cm), PT (15.02 ± 9.55° vs. 9.99 ± 2.97°) and TLK (7.69 ± 6.66° vs. 3.54 ± 1.63°) were significantly larger in DDH patients, whereas LL (37.41 ± 17.17° vs. 48.79 ± 7.75°) was significantly smaller (P < 0.05). No correlation was found between significantly different spinopelvic parameters and the extent of dysplasia. Statistical analysis revealed correlations between ODI and Cobb angle (r = 0.59, P < 0.01), PT (r = 0.49, P = 0.02), TK (r = -0.46, P = 0.03) and TLK (r = 0.44, P = 0.04). Correlations between JOABPQE score and the Cobb angle (r = -0.44, P = 0.04), L3IA (r = -0.53, P = 0.01), PT (r = -0.44, P = 0.04), and TK (r = 0.46, P = 0.03) were also observed. CONCLUSIONS: Cobb angle, L3IA, C7PL-CSVL in coronal plane and PT, TLK in sagittal plane increased, while LL decreased in unilateral DDH patients. These significantly different spinopelvic parameters have no correlation with the extent of dysplasia. Changes in coronal and sagittal plane including Cobb angle, L3IA, PT, TK and TLK were associated with the low back pain in the patients with unilateral DDH.

The COVID-19 Vaccination Behavior and Correlates in Diabetic Patients: A Health Belief Model Theory-Based Cross-Sectional Study in China, 2021.

The population with diabetes is more susceptible to severe acute respiratory syndrome-associated coronavirus (SARS-CoV)-2, and have a significantly higher coronavirus disease-2019 (COVID-19) mortality rate. Previous studies have shown low willingness for the COVID-19 vaccination, and there are limited reports on the behavior and relevance of the COVID-19 vaccination. This study aimed to determine the uptake behavior and associated factors of the COVID-19 vaccine. In our cross-sectional questionnaire-based clinical study, 645 diabetes patients affiliated with two affiliated hospitals of Changzhi Medical College completed the questionnaire between June to October 2021. The health belief model (HBM) was used in examining factors influencing vaccination behavior. After adjusting for covariates with significant differences in social background characteristics, a multivariable logistic regression was used to determine predictors related to uptake in COVID-19 vaccination. A total of 162 vaccinated and 483 unvaccinated eligible diabetic patients were recruited. Patients who believed that the COVID-19 syndrome is severe (aOR3.67, 95%CI 1.88−7.17; p < 0.001), believe that vaccination can significantly reduce the risk of SARS-Cov-2 infection (aOR3.48, 95%CI 1.80−6.73; p < 0.001), believe that vaccination is beneficial to themselves and others (aOR 4.53, 95%CI 1.71−11.99; p = 0.002), think that relatives' vaccination status has a positive impact on their vaccination behavior (aOR 5.68, 95%CI 2.83−11.39; p < 0.001), and were more likely to be vaccinated; worrying about the adverse health effects of COVID-19 vaccination (aOR 0.18, 95%CI 0.09−0.35; p < 0.001) was negatively correlated with COVID-19 vaccination behavior. Health care workers should provide targeted informative interventions based on the safety and protective effects theory of HBM to improve vaccination behavior in patients with diabetes.

COVID-19 Vaccine Hesitancy and Associated Factors among Diabetes Patients: A Cross-Sectional Survey in Changzhi, Shanxi, China.

Patients with diabetes are more susceptible to severe acute respiratory syndrome-associated coronavirus (SARS-CoV)-2 infection, but vaccine hesitancy is a problem in this population. We investigated the prevalence of SARS-CoV-2 vaccine hesitancy among diabetes patients in China through a cross-sectional survey from April and August 2021 using a questionnaire administered to patients at two hospitals affiliated with Changzhi Medical College (Shanxi, China). The health belief model (HBM) is used examining factors influencing vaccine hesitancy. After adjusting for potential confounders, a multivariate logistic regression model was used to analyze correlations between vaccine hesitancy and associated factors. Of the 483 participants, 56.4% (273/483) had vaccine hesitancy, including 58.2% (159/273) who were unsure of being vaccinated and 41.8% (114/273) who were unwilling. Although patients considered SARS-CoV-2 infection to be serious (adjusted odds ratio [aOR] = 3.90, 95% confidence interval [CI]: 2.36-6.42; p < 0.001), they had concerns about vaccine safety (aOR = 3.05, 95% CI: 1.89-4.91; p < 0.001). Relatives' vaccination status did not influence participants' willingness to be vaccinated (aOR = 2.43, 95% CI: 1.39-4.25; p < 0.001). Disagreement with physicians' view that vaccination can reduce SARS-CoV-2 infection risk was independently correlated with vaccine hesitancy (aOR = 2.25, 95% CI: 1.28-3.95; p < 0.001). Diabetes patients in China need to be educated on SARS-CoV-2 vaccine safety and protective effects to increase the vaccination rate in this population.

Ligand removal of Au25 nanoclusters by thermal and electrochemical treatments for selective CO2 electroreduction to CO.

Undercoordinated metal nanoclusters have shown great promise for various catalytic applications. However, their activity is often limited by the covalently bonded ligands, which could block the active surface sites. Here, we investigate the ligand removal process for Au25 nanoclusters using both thermal and electrochemical treatments, as well as its impact on the electroreduction of CO2 to CO. The Au25 nanoclusters are synthesized with 2-phenylethanethiol as the capping agent and anchored on sulfur-doped graphene. The thiolate ligands can be readily removed under either thermal annealing at ≥180°C or electrochemical biasing at ≤-0.5 V vs reversible hydrogen electrode, as evidenced by the Cu underpotential deposition surface area measurement, x-ray photoelectron spectroscopy, and extended x-ray absorption fine structure spectroscopy. However, these ligand-removing treatments also trigger the structural evolution of Au25 nanoclusters concomitantly. The thermally and electrochemically treated Au25 nanoclusters show enhanced activity and selectivity for the electrochemical CO2-to-CO conversion than their pristine counterpart, which is attributed to the exposure of undercoordinated Au sites on the surface after ligand removal. This work provides facile strategies to strip away the staple ligands from metal nanoclusters and highlights its importance in promoting the catalytic performances.

High-Performance Pt-Co Nanoframes for Fuel-Cell Electrocatalysis.

Pt-based alloy catalysts are promising candidates for fuel-cell applications, especially for cathodic oxygen reduction reaction (ORR) and anodic methanol oxidation reaction (MOR). The rational design of composition and morphology is crucial to promoting catalytic performances. Here, we report the synthesis of Pt-Co nanoframes via chemical etching of Co from solid rhombic dodecahedra. The obtained Pt-Co nanoframes exhibit excellent ORR mass activity in acidic electrolyte, which is as high as 0.40 A mgPt-1 initially and 0.34 A mgPt-1 after 10 000 potential cycles at 0.95 VRHE. Furthermore, their MOR mass activity in alkaline media is up to 4.28 A mgPt-1 and is 4-fold higher than that of commercial Pt/C catalyst. Experimental studies indicate that the weakened binding of intermediate carbonaceous poison contributes to the enhanced MOR behavior. More impressively, the Pt-Co nanoframes also demonstrate remarkable stability under long-term testing, which could be attributed to the negligible electrochemical Co dissolution.

Surface and Interface Control in Nanoparticle Catalysis.

The surface and interfaces of heterogeneous catalysts are essential to their performance as they are often considered to be active sites for catalytic reactions. With the development of nanoscience, the ability to tune surface and interface of nanostructures has provided a versatile tool for the development and optimization of a heterogeneous catalyst. In this Review, we present the surface and interface control of nanoparticle catalysts in the context of oxygen reduction reaction (ORR), electrochemical CO2 reduction reaction (CO2 RR), and tandem catalysis in three sections. In the first section, we start with the activity of ORR on the nanoscale surface and then focus on the approaches to optimize the performance of Pt-based catalyst including using alloying, core-shell structure, and high surface area open structures. In the section of CO2 RR, where the surface composition of the catalysts plays a dominant role, we cover its reaction fundamentals and the performance of different nanosized metal catalysts. For tandem catalysis, where adjacent catalytic interfaces in a single nanostructure catalyze sequential reactions, we describe its concept and principle, catalyst synthesis methodology, and application in different reactions.

PtCuNi Tetrahedra Catalysts with Tailored Surfaces for Efficient Alcohol Oxidation.

Direct methanol/ethanol alkaline fuel cells (DMAFCs/DEAFCs) represent an attractive mobile power generation technology. The methanol/ethanol oxidation reaction (MOR/EOR) often requires high-performance yet expensive Pt-based catalysts that may be easily poisoned. Herein, we report the development of PtCuNi tetrahedra electrocatalysts with optimized specific activity and mass activity for MOR and EOR. Our synthetic and structural characterizations show that these PtCuNi tetrahedra have Cu-rich core and PtNi-rich shell with tunable surface composition. Electrocatalytic studies demonstrate that Pt56Cu28Ni16 exhibits exceptional MOR and EOR specific activities of 14.0 ± 1.0 mA/cm2 and 11.2 ± 1.0 mA/cm2, respectively and record high mass activity of 7.0 ± 0.5 A/mgPt and 5.6 ± 0.6 A/mgPt, comparing favorably with the best MOR or EOR Pt alloy-based catalysts reported to date. Furthermore, we show that the unique core-shell tetrahedra configuration can also lead to considerably improved durability.

[Effect and mechanisms of vitamin E on early steroid-induced avascular necrosis of femoral head in rats].

OBJECTIVE: To investigate the possibility of mitochondria-dependent apoptosis as a mechanism of early steroid-induced avascular necrosis of femoral head (SANFH) in rats and vitamin E as a possible prevention strategy. METHODS: Seventy-two male Sprague Dawley rats were randomly divided into control group, model group, and intervention group, with 24 rats in each group. The rats in control group were not treated as normal control. The rats in model group and intervention group were established early SANFH models by lipopolysaccharide combined with methylprednisolone injection. At the same time, the rats in intervention group were injected with vitamin E (40 mg/kg) every day for 7 days. At 2, 4, and 8 weeks after the final injection, the bilateral femoral heads were harvested and observed by HE staining, TUNEL assay, immunohistochemical staining, and Western blot. The rate of empty lacunae, apoptotic index, and the expressions of Caspase-9, Caspase-3, and cytochrome-c (Cyt-c) proteins were calculated. RESULTS: According to histological staining, there were significant differences in the rate of empty lacunae between intervention group and control group at 8 weeks ( P<0.05) and between intervention group and model group at 4 and 8 weeks ( P<0.05). The apoptotic index of intervention group was significantly lower than that of model group at each time point ( P<0.05). And there was significant difference between the intervention group and the control group at 8 weeks ( P<0.05). According to immunohistochemistry staining and Western blot, the expressions of Cyt-c, Caspase-9, and Caspase-3 all significantly decreased in intervention group than those in model group at each time point ( P<0.05); and the differences were significant between intervention group and control group at 8 weeks ( P<0.05). CONCLUSION: Vitamin E can delay the progression of early SANFH by reducing mitochondrial dependent osteocyte apoptosis.

Solution-processable 2D semiconductors for high-performance large-area electronics.

Two-dimensional (2D) materials, consisting of atomically thin crystal layers bound by the van der Waals force, have attracted much interest because of their potential in diverse technologies, including electronics, optoelectronics and catalysis1-10. In particular, solution-processable 2D semiconductor (such as MoS2) nanosheets are attractive building blocks for large-area thin-film electronics. In contrast to conventional zero- and one-dimensional nanostructures (quantum dots and nanowires, respectively), which are typically plagued by surface dangling bonds and associated trapping states, 2D nanosheets have dangling-bond-free surfaces. Thin films created by stacking multiple nanosheets have atomically clean van der Waals interfaces and thus promise excellent charge transport11-15. However, preparing high-quality solution-processable 2D semiconductor nanosheets remains a challenge. For example, MoS2 nanosheets and thin films produced using lithium intercalation and exfoliation are plagued by the presence of the metallic 1T phase and poor electrical performance (mobilities of about 0.3 square centimetres per volt per second and on/off ratios of less than 10)2,12, and materials produced by liquid exfoliation exhibit an intrinsically broad thickness distribution, which leads to poor film quality and unsatisfactory thin-film electrical performance (mobilities of about 0.4 square centimetres per volt per second and on/off ratios of about 100)14,16,17. Here we report a general approach to preparing highly uniform, solution-processable, phase-pure semiconducting nanosheets, which involves the electrochemical intercalation of quaternary ammonium molecules (such as tetraheptylammonium bromide) into 2D crystals, followed by a mild sonication and exfoliation process. By precisely controlling the intercalation chemistry, we obtained phase-pure, semiconducting 2H-MoS2 nanosheets with a narrow thickness distribution. These nanosheets were then further processed into high-performance thin-film transistors, with room-temperature mobilities of about 10 square centimetres per volt per second and on/off ratios of 106 that greatly exceed those obtained for previous solution-processed MoS2 thin-film transistors. The scalable fabrication of large-area arrays of thin-film transistors enabled the construction of functional logic gates and computational circuits, including an inverter, NAND, NOR, AND and XOR gates, and a logic half-adder. We also applied our approach to other 2D materials, including WSe2, Bi2Se3, NbSe2, In2Se3, Sb2Te3 and black phosphorus, demonstrating its potential for generating versatile solution-processable 2D materials.

Effects of Catalyst Processing on the Activity and Stability of Pt-Ni Nanoframe Electrocatalysts.

Pt-based alloys have shown great promise as cathodic catalysts for cost-effective proton-exchange membrane fuel cells. Post-synthesis treatment has been recognized as a critical step to improve the catalytic performance of Pt-based alloys. Here, we present the effects of catalyst processing on the catalytic behavior of Pt-Ni nanoframe electrocatalysts in oxygen reduction reaction. The Pt-Ni nanoframes were made by corroding the Ni-rich phase from solid rhombic dodecahedral particles. A total of three different corrosion procedures were compared. Among them, electrochemical corrosion led to the highest initial specific activity (1.35 mA cm-2 at 0.95 V versus reversible hydrogen electrode) by retaining more Ni in the nanoframes. However, the high activity gradually went down in a subsequent stability test due to continuous Ni loss and concomitant surface reconstruction. On the other hand, the best stability was achieved by a more-aggressive corrosion using oxidative nitric acid. Although the initial activity was compromised, this procedure imparted a less-defective surface, and thus, the specific activity dropped by only 7% over 30 000 potential cycles. These results indicate a delicate trade-off between the activity and stability of Pt-Ni nanoframe electrocatalysts. The obtained understanding of how to balance the activity-stability trade-off via catalyst processing can be generalized to other Pt-based alloys.

On-Chip in Situ Monitoring of Competitive Interfacial Anionic Chemisorption as a Descriptor for Oxygen Reduction Kinetics.

The development of future sustainable energy technologies relies critically on our understanding of electrocatalytic reactions occurring at the electrode-electrolyte interfaces, and the identification of key reaction promoters and inhibitors. Here we present a systematic in situ nanoelectronic measurement of anionic surface adsorptions (sulfates, halides, and cyanides) on ultrathin platinum nanowires during active electrochemical processes, probing their competitive adsorption behavior with oxygenated species and correlating them to the electrokinetics of the oxygen reduction reaction (ORR). The competitive anionic adsorption features obtained from our studies provide fundamental insight into the surface poisoning of Pt-catalyzed ORR kinetics by various anionic species. Particularly, the unique nanoelectronic approach enables highly sensitive characterization of anionic adsorption and opens an efficient pathway to address the practical poisoning issue (at trace level contaminations) from a fundamental perspective. Through the identified nanoelectronic indicators, we further demonstrate that rationally designed competitive anionic adsorption may provide improved poisoning resistance, leading to performance (activity and lifetime) enhancement of energy conversion devices.