A Hybrid Handover Scheme for Vehicular VLC/RF Communication Networks.

Visible light communication (VLC) is a promising complementary technology to its radio frequency (RF) counterpart to satisfy the high quality-of-service (QoS) requirements of intelligent vehicular communications by reusing LED street lights. In this paper, a hybrid handover scheme for vehicular VLC/RF communication networks is proposed to balance QoS and handover costs by considering the vertical handover and horizontal handover together judging from the mobile state of the vehicle. A Markov decision process (MDP) is formulated to describe this hybrid handover problem, with a cost function balancing the handover consumption, delay, and reliability. A value iteration algorithm was applied to solve the optimal handover policy. The simulation results demonstrated the performance of the proposed hybrid handover scheme in comparison to other benchmark schemes.

Crossover between rigid and reconstructed moiré lattice in h-BN-encapsulated twisted bilayer WSe2 with different twist angles.

A moiré lattice in a twisted-bilayer transition metal dichalcogenide (tBL-TMD) exhibits a complex atomic reconstruction effect when its twist angle is less than a few degrees. The influence of the atomic reconstruction on material properties of the tBL-TMD has been of particular interest. In this study, we performed scanning transmission electron microscopy (STEM) imaging of a moiré lattice in h-BN-encapsulated twisted bilayer WSe2 with various twist angles. Atomic-resolution imaging of the moiré lattice revealed a reconstructed moiré lattice below a crossover twist angle of ∼4° and a rigid moiré lattice above this angle. Our findings indicate that h-BN encapsulation has a considerable influence on lattice reconstruction, as the crossover twist angle was larger in h-BN-encapsulated devices compared to non-encapsulated devices. We believe that this difference is due to the improved flatness and uniformity of the twisted bilayers with h-BN encapsulation. Our results provide a foundation for a deeper understanding of the lattice reconstruction in twisted TMD materials with h-BN encapsulation.

A prediction nomogram for hepatitis B virus-associated hepatocellular carcinoma.

BACKGROUND: The present study aimed to develop and validate a new nomogram for predicting the incidence of hepatocellular carcinoma (HCC) among chronic hepatitis B (CHB) patients receiving antiviral therapy from real-world data. METHODS: The nomogram was established based on a real-world retrospective study of 764 patients with HBV from October 2008 to July 2020. A predictive model for the incidence of HCC was developed by multivariable Cox regression, and a nomogram was constructed. The predictive accuracy and discriminative ability of the nomogram were assessed by the concordance index (C-index), calibration curves, and decision curve analysis (DCA). Risk group stratification was performed to assess the predictive capacity of the nomogram. The nomogram was compared to three current commonly used predictive models. RESULTS: A total of 764 patients with HBV were recruited for this study. Age, family history of HCC, alcohol consumption, and Aspartate aminotransferase-to-Platelet Ratio Index (APRI) were all independent risk predictors of HCC in CHB patients. The constructed nomogram had good discrimination with a C-index of 0.811. The calibration curve and DCA also proved the reliability and accuracy of the nomogram. Three risk groups (low, moderate, and high) with significantly different prognoses were identified (p < 0.001). The model's performance was significantly better than that of other risk models. CONCLUSIONS: The nomogram was superior in predicting HCC risk among CHB patients who received antiviral treatment. The model can be utilized in clinical practice to aid decision-making on the strategy of long-term HCC surveillance, especially for moderate- and high-risk patients.

Field study on pregnant women's thermal preference in different trimesters in winter.

This study investigated the differences in the thermal preferences of pregnant women during various trimesters and the factors influencing these preferences. The survey was conducted in a hospital waiting room, encompassing the testing of thermal environmental parameters, and the distribution of questionnaires to pregnant women. These questionnaires encompassed various aspects, including basic information, thermal responses, pregnancy diseases, and more. In total, 1388 questionnaires were collected, distributed across the first trimester (225 participants), second trimester (498 participants), and third trimester (665 participants). The findings revealed a notable shift in the thermal preferences of pregnant women as their pregnancies progressed, transitioning from a preference for warmer conditions to a preference for cooler environments. Specifically, the mean thermal preference scores for the first, second, and third trimesters were 0.82, -0.27, and -1.76, respectively. These shifting preferences were associated with various factors, including pregnancy diseases, pre-pregnancy body mass index (PBMI), and exercise habits. Notably, hyperthyroidism, a higher PBMI, and regular exercise were correlated with a preference for cooler conditions, whereas hypothyroidism, anemia, a lower PBMI, and rare exercise were associated with a preference for warmer environments. Furthermore, it was observed that the actual neutral temperatures for pregnant women in the first, second, and third trimesters were 20.3 °C, 19.5 °C, and 19 °C, respectively. By contrast, the predicted neutral temperatures were 23.5 °C for the first and third trimesters and 23.4 °C for the second trimester. This indicated that the Predicted Mean Vote (PMV) model tended to underestimate the acceptability that pregnant women experienced in colder environments. Given the unique thermal preferences of pregnant women, further research is essential to refine thermal comfort parameters and the PMV model tailored specifically to this demographic.

Symmetry Engineering in Twisted Bilayer WTe2.

The fabrication of artificial structures using a twisted van der Waals assembly has been a key technique for recent advancements in the research of two-dimensional (2D) materials. To date, various exotic phenomena have been observed thanks to the modified electron correlation or moiré structure controlled by the twist angle. However, the twisted van der Waals assembly has further potential to modulate the physical properties by controlling the symmetry. In this study, we fabricated twisted bilayer WTe2 and demonstrated that the twist angle successfully controls the spatial inversion symmetry and hence the spin splitting in the band structure. Our results reveal the further potential of a twisted van der Waals assembly, suggesting the feasibility of pursuing new physical phenomena in 2D materials based on the control of symmetry.

Lipid acyl chain protrusion induced by the influenza virus hemagglutinin fusion peptide detected by NMR paramagnetic relaxation enhancement.

The glycoprotein spikes of membrane-enveloped viruses include a subunit that catalyzes fusion (joining) of the viral and target cell membranes. For influenza virus, this is subunit 2 of hemagglutinin which has a âˆ¼ 20-residue N-terminal fusion peptide (Fp) region that binds target membrane. An outstanding question is whether there are associated membrane changes important for fusion. Several computational studies have found increased "protrusion" of lipid acyl chains near Fp, i.e. one or more chain carbons are closer to the aqueous region than the headgroup phosphorus. Protrusion may accelerate initial joining of outer leaflets of the two membranes into a stalk intermediate. In this study, higher protrusion probability in membrane with vs. without Fp is convincingly detected by larger Mn2+-associated increases in chain 13C NMR transverse relaxation rates (Γ2's). Data analysis provides a ratio Γ2,neighbor/Γ2,distant for lipids neighboring vs. more distant from the Fp. The calculated ratio depends on the number of Fp-neighboring lipids and the experimentally-derived range of 4 to 24 matches the range of increased protrusion probabilities from different simulations. For samples either with or without Fp, the Γ2 values are well-fitted by an exponential decay as the 13C site moves closer to the chain terminus. The decays correlate with free-energy of protrusion proportional to the number of protruded -CH2 groups, with free energy per -CH2 of ∼0.25 kBT. The NMR data support one major fusion role of the Fp to be much greater protrusion of lipid chains, with highest protrusion probability for chain regions closest to the headgroups.

All-dry flip-over stacking of van der Waals junctions of 2D materials using polyvinyl chloride.

We demonstrated an all-dry polymer-to-polymer transfer technique for two-dimensional (2D) crystal flakes using a polyvinyl chloride (PVC) layer deposited on a piece of polydimethylsiloxane (PDMS). Unexpectedly, the pickup/release temperatures were modified in wider temperature range simply by changing the thickness of the PVC layer than changing the plasticizer ratio. Utilizing the difference in the pickup/release temperatures depending on the PVC film thickness, 2D flakes were transferred from a thicker PVC film to a thinner one. This polymer-to-polymer transfer technique can be utilized to flip over van der Waals heterostructures. As a demonstration, we fabricated a mountain-like stacked structure of hexagonal boron nitride flakes using the flip-over stacking technique. Finally, we compared the results of thermomechanical analysis with the pickup/release temperatures of the PVC/PDMS stamp. The PVC was revealed to be at the glass transition and in the viscoelastic flow regimes when the 2D flakes were picked up and dry released, respectively. Our polymer-to-polymer transfer method facilitates flip-over van der Waals stacking in an all-dry manner, expanding the possibility of 2D materials device fabrications.

Epidemiological characteristics and survival analysis on patients with occupational pneumoconiosis in Zhejiang Province from 1987 to 2019.

Objective: To evaluate risk factors affecting survival in patients diagnosed with pneumoconiosis and propose strategies to improve the quality of life in these patients. Methods: The basic patient information was obtained from the pneumoconiosis report card. Disease types, regions, and industry distribution of pneumoconiosis were analyzed. The Kaplan-Meier survival curves and the Cox proportional risk regression model was used for survival analysis. Results: A total of 13,812 patients were diagnosed with pneumoconiosis in Zhejiang province from 1987 to 2019. The overall survival rate at the end of life table analysis was 83%. Kaplan-Meier analyses showed that there were significant differences between survival curves depending on the stage of first diagnosis, age at first diagnosis, type of pneumoconiosis, industry, and duration of dust exposure (P < 0.05). The results of Cox proportional hazards regression analysis showed that pneumoconiosis stage of first diagnosis, age at first diagnosis, industry, and duration of dust exposure were risk factors affecting patient survival (P < 0.05). Conclusions: The patients with high stage of pneumoconiosis at first diagnosis, older age, and long duration of dust exposure should be followed up and monitored as key population, and the industries with high incidence of pneumoconiosis such as mining and construction should be supervised as key industries.

Resonant Tunneling between Quantized Subbands in van der Waals Double Quantum Well Structure Based on Few-Layer WSe2.

We demonstrate van der Waals double quantum well (vDQW) devices based on few-layer WSe2 quantum wells and a few-layer h-BN tunnel barrier. Due to the strong out-of-plane confinement, an exfoliated WSe2 exhibits quantized subband states at the Γ point in its valence band. Here, we report resonant tunneling and negative differential resistance in vDQW at room temperature owing to momentum- and energy-conserved tunneling between the quantized subbands in each well. Compared to single quantum well (QW) devices with only one QW layer possessing quantized subbands, superior current peak-to-valley ratios were obtained for the DQWs. Our findings suggest a new direction for utilizing few-layer-thick transition metal dichalcogenides in subband QW devices, bridging the gap between two-dimensional materials and state-of-the-art semiconductor QW electronics.

Methylation of the HCBP6 promoter is associated with primary biliary cholangitis pathogenesis.

Hepatitis C virus core-binding protein 6 (HCBP6), first characterized in our laboratory and also referred to as FUNDC2, is involved in lipid and glucose metabolism, platelet activation, and platelet survival. Here we demonstrate that hypermethylation of mitochondrial HCBP6 is linked Primary Biliary Cholangitis (PBC) pathogenesis. Serum and liver levels of HCBP6 in PBC patients were reduced in comparison with controls. Further research confirmed a correlation between CpG1 hypermethylation and HCBP6 levels. Taken together, our results reveal another new feature of HCBP6.

Comparative Analysis of Heat-Tolerant and Heat-Susceptible Rice Highlights the Role of OsNCED1 Gene in Heat Stress Tolerance.

To elucidate the mechanism underlying the response of rice to heat stress (HS), the transcriptome profile of panicles was comparatively analyzed between the heat-tolerant line 252 (HTL252) and heat-susceptible line 082 (HSL082), two rice recombinant inbred lines (RILs). Our differentially expressed gene (DEG) analysis revealed that the DEGs are mainly associated with protein binding, catalysis, stress response, and cellular process. The MapMan analysis demonstrated that the heat-responsive (HR) genes for heat shock proteins, transcription factors, development, and phytohormones are specifically induced in HTL252 under HS. Based on the DEG analysis, the key gene OsNCED1 (Os02g0704000), which was induced under HS, was selected for further functional validation. Moreover, 9-cis-epoxycarotenoid dioxygenase (NCED) is a key rate-limiting enzyme in the ABA biosynthetic pathway. Overexpression of OsNCED1 improved the HS tolerance of rice at the heading and flowering stage. OsNCED1-overexpression plants exhibited significant increases in pollen viability, seed setting rate, superoxide dismutase (SOD) and peroxidase (POD) activities, while significantly lower electrolyte leakage and malondialdehyde (MDA) content relative to the wild type (WT). These results suggested that OsNCED1 overexpression can improve the heat tolerance of rice by enhancing the antioxidant capacity. Overall, this study lays a foundation for revealing the molecular regulatory mechanism underlying the response of rice to prolonged HS.

9-cis-epoxycarotenoid dioxygenase 1 confers heat stress tolerance in rice seedling plants.

High temperature is one of the main constraints affecting plant growth and development. It has been reported that abscisic acid (ABA) synthesis gene 9-cis-epoxycarotenoid dioxygenase (NCED) positively regulates plant resistance to salt, cold, and drought stresses. However, little is known about the function of the NCED gene in heat tolerance of rice. Here, we found that OsNCED1 was a heat stress inducible gene. Rice seedlings overexpressing OsNCED1 showed enhanced heat tolerance with more abundant ABA content, whereas the knockout mutant osnced1 accumulated less ABA and showed more sensitive to heat stress. Under heat stress, increased expression of OsNCED1 could reduce membrane damage and reactive oxygen species (ROS) level of plants, and elevate the activity of antioxidant enzymes. Moreover, real time-quantitative PCR (RT-qPCR) analysis showed that overexpression of OsNCED1 significantly activated the expression of genes involved in antioxidant enzymes, ABA signaling pathway, heat response, and defense. Together, our results indicate that OsNCED1 positively regulates heat tolerance of rice seedling by raising endogenous ABA contents, which leads to the improved antioxidant capacity and activated expression of heat and ABA related genes.

An EjbHLH14-EjHB1-EjPRX12 module is involved in methyl jasmonate alleviation of chilling-induced lignin deposition in loquat fruit.

Loquat fruit are susceptible to chilling injuries induced by postharvest storage at low temperature. The major symptoms are increased lignin content and flesh firmness, which cause a leathery texture. Pretreatment with methyl jasmonate (MeJA) can alleviate this low-temperature-induced lignification, but the mechanism is not understood. In this study, we characterized a novel class III peroxidase, EjPRX12, and studied its relationship to lignification. Transcript levels of EjPRX12 were attenuated following MeJA pretreatment, consistent with the reduced lignin content in fruit. In vitro enzyme activity assay indicated that EjPRX12 polymerized sinapyl alcohol, and overexpression of EjPRX12 in Arabidopsis promoted lignin accumulation, indicating that it plays a functional role in lignin polymerization. We also identified an HD-ZIP transcription factor, EjHB1, repressed by MeJA pretreatment, which directly bound to and significantly activated the EjPRX12 promoter. Overexpression of EjHB1 in Arabidopsis promoted lignin accumulation with induced expression of lignin-related genes, especially AtPRX64. Furthermore, a JAZ-interacting repressor, EjbHLH14, was characterized, and it is proposed that MeJA pretreatment caused EjbHLH14 to be released to repress the expression of EjHB1. These results identified a novel regulatory pathway involving EjbHLH14-EjHB1-EjPRX12 and revealed the molecular mechanism whereby MeJA alleviated lignification of loquat fruit at low temperature.

Tailoring of Surface Acidic Sites in Co-MoS2 Catalysts for Hydrodeoxygenation Reaction.

CoMo sulfides are typical catalysts for selective hydrodeoxygenation (HDO) of phenolics to aromatics which is important in bio-oil upgrading. However, it is still a challenge to promote the intrinsic activity of Co-MoS2 catalysts. Defect chemistry provides a good option to improve surface reactivity in catalysis. In this work, we report a facile H2O2 etching method to tailor the concentration of surface acidic sites. The molar ratio of H2O2/MoS2 can be altered to tune sulfur defects on the MoS2 surface for stabilizing Co species to form CoMoS active sites. The optimized Co-MoS2-2 catalyst, with the highest concentration of acidic sites, exhibits 3.4 times higher activity than the Co-MoS2-0 sample in the HDO of p-cresol to toluene. It is also found the HDO activity shows a linear relationship with the amount of surface acid (both Lewis and Brønsted acid) over the Co-MoS2-x catalysts. We believe that the understanding of the role of surface acidity would provide new opportunities for the rational design of efficient Co-MoS2 catalysts.

Resonant Tunneling Due to van der Waals Quantum-Well States of Few-Layer WSe2 in WSe2/h-BN/p+-MoS2 Junction.

Few-layer transition metal dichalcogenides (TMDs) exhibit out-of-plane wave function confinement with subband quantization. This phenomenon is totally absent in monolayer crystals and is regarded as resulting from a naturally existing van der Waals quantum-well state. Because the energy separation between the subbands corresponds to the infrared wavelength range, few-layer TMDs are attractive for their potential to facilitate the application of TMD semiconductors as infrared photodetectors and emitters. Here, we report a few-layer WSe2/h-BN tunnel barrier/multilayer p+-MoS2 tunnel junction to access the quantized subbands of few-layer WSe2 via tunneling spectroscopy measurements. Resonant tunneling and a negative differential resistance were observed when the top of the valence band Γ-point of p+-MoS2 was energetically aligned with one of the empty subbands at the Γ-point of few-layer WSe2. These results demonstrate a critical step toward the utilization of subband quantization in few-layer TMD materials for infrared optoelectronics applications.

Online teaching self-efficacy during COVID-19: Changes, its associated factors and moderators.

Online teaching transition during COVID-19 school lockdown elicited challenges for teachers and schools across the globe. The existing literature on the impact of COVID-19 in the education sector is predominantly descriptive and focused on the difficulties faced by teachers during the process of transferring into online teaching, mainly in the higher education sector. This study adopted a mixed-method design to examine online teaching self-efficacy (TSE) during COVID-19, its associated factors and moderators. A sample of 351 Chinese school teachers retrospectively reported their online TSE at the beginning and end of COVID-19 school lockdown, out of which six were followed up for an in-depth interview. TSE for online instruction did not significantly increase (ß = .014, p > 0.05) whereas that for technology application increased significantly (ß = .231, p < 0.01). Lack of experience in online teaching, separation of teachers from students, school administrative process and unsatisfactory student academic performance were identified as the major associated factors. A moderation effect of adaptability and teacher burnout on the change in online TSE were examined, of which passion burnout was the only significant moderator toward the change in online TSE. The study thus concluded that teachers' online TSE for technology application increased among Chinese teachers during COVID-19 school lockdown. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s10639-021-10486-3.

A suspected case of COVID-19 turned into a confirmed case: a case report.

COVID-19 (coronavirus disease 2019) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and discovered in 2019. The clinical manifestations include fever, coughing, difficulty in breathing and even death from multiple organ failure. Nucleic acid test is the golden standard method for confirmation of infection. According to the Chinese 'Seventh Edition of the COVID-19 Diagnosis and Treatment Protocol', suspected patients with negative nucleic acid tests from two consecutive airway specimens can be excluded from diagnosis and released from quarantine. The current report describes a suspected COVID-19 case that had a history of close contact with a COVID-19 patient. The diagnosis was confirmed after the SARS-CoV-2 nucleic acid was detected after four sputum sample tests (sampling interval of at least 24 h).

Improving the early diagnosis of suspected patients with COVID-19: a retrospective study of 106 patients.

INTRODUCTION: An outbreak of coronavirus disease 2019 (COVID-19) occurred in Wuhan, Hubei Province, China. This study aimed to analyze the clinical and epidemiologic characteristics of patients with COVID-19 to better differentiate the suspected patients in Beijing, China. METHODOLOGY: This was a retrospective, single-center study. Clinical and epidemiologic data were collected from suspected patients with COVID-19 admitted to Beijing Ditan Hospital from January 29 to February 21, 2020. RESULTS: One hundred and six patients (60 males and 46 females, median age 36 years) were enrolled. Thirty-six patients were ultimately laboratory confirmed. Fifty-three were excluded from the diagnosis of COVID-19. The remaining 17 patients were highly suspected, although their nucleic acid tests were repeatedly negative. The confirmed patients and highly suspected patients had a significantly higher proportion of epidemiologic history than the excluded patients (P < 0.001). There was no significant difference in clinical symptoms or the underlying diseases among the three groups. The confirmed patients had a higher frequency of lymphopenia and eosinopenia than the highly suspected and excluded patients. Chest computed tomography scans showed bilateral lung involvement, and ground-glass opacity was more likely observed in the confirmed patients. CONCLUSION: The clinical features of the confirmed patients with COVID-19 were insufficient for early diagnosis of COVID-19. The epidemiologic history was of great significance in the early diagnosis of COVID-19. More sensitive diagnostic methods are needed to aid the differential diagnosis of suspected patients with COVID-19.

A family cluster of severe acute respiratory syndrome coronavirus 2 infections.

Clinical and epidemiological knowledge of 2019 novel coronavirus disease (COVID-19) is limited. We reported a family cluster of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) cases in Beijing, China. This family comprised three laboratory confirmed cases with clinical symptoms. All three patients had close contact with a relative from Wuhan, Hubei Province. Throat swab samples were all positive for SARS-CoV-2 using real-time reverse transcriptase-polymerase chain reaction assays. Chest computerized tomography revealed ground-glass opacities and consolidation. SARS-CoV-2 infections tend to clusters. Physicians should be aware of contact history so that infected patients can be identified promptly and further spreading prevented.

Association between osteoporosis and hepatitis B cirrhosis: a case-control study.

BACKGROUND AND AIMS: Hepatitis B virus (HBV)-related cirrhosis is associated with decreased bone mineral density (BMD); however, the mechanism is yet unknown. To assess the incidence of osteoporosis in patients with HBV-associated cirrhosis and relevant mechanisms. METHODS: A total of 80 hospitalized patients with HBV-associated cirrhosis and 80 healthy controls were enrolled. The levels of serum osteocalcin, total procollagen type 1 amino-terminal propeptide, ß-C-terminal telopeptide of type I collagen (ß-CTX), and 25-hydroxy vitamin D3 (25(OH)D3) was evaluated in the cirrhosis group. RESULTS: The BMDs of the lumbar spine (P<0.001) and hip joints (P=0.015) in the cirrhosis group were significantly lower than those in the controls. The incidence of osteoporosis in the cirrhosis group was significantly higher than that in the control group (P<0.001). Compared to the patients of the Child-Pugh grade A and B, the BMD of lumbar spine and 25(OH)D3 was significantly decreased in patients of grade C, while ß-CTX was elevated. Patients in the cirrhosis group faced a higher risk of osteoporosis as compared to the controls(P<0.001). CONCLUSIONS: Enhanced bone resorption accounted for increased risk of osteoporosis in severe cirrhosis. Thus, HBV-associated cirrhosis was a risk factor for osteoporosis.