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.

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.

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.

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.

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.

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.

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 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.

Exciton Hall effect in monolayer MoS2.

The spontaneous Hall effect driven by the quantum Berry phase (which serves as an internal magnetic flux in momentum space) manifests the topological nature of quasiparticles and can be used to control the information flow, such as spin and valley. We report a Hall effect of excitons (fundamental composite particles of electrons and holes that dominate optical responses in semiconductors). By polarization-resolved photoluminescence mapping, we directly observed the Hall effect of excitons in monolayer MoS2 and valley-selective spatial transport of excitons on a micrometre scale. The Hall angle of excitons is found to be much larger than that of single electrons in monolayer MoS2 (ref. ), implying that the quantum transport of the composite particles is significantly affected by their internal structures. The present result not only poses a fundamental problem of the Hall effect in composite particles, but also offers a route to explore exciton-based valleytronics in two-dimensional materials.

Superconductivity in Pristine 2H_{a}-MoS_{2} at Ultrahigh Pressure.

As a follow-up of our previous work on pressure-induced metallization of the 2H_{c}-MoS_{2} [Chi et al., Phys. Rev. Lett. 113, 036802 (2014)PRLTAO0031-900710.1103/PhysRevLett.113.036802], here we extend pressure beyond the megabar range to seek after superconductivity via electrical transport measurements. We found that superconductivity emerges in the 2H_{a}-MoS_{2} with an onset critical temperature T_{c} of ca. 3 K at ca. 90 GPa. Upon further increasing the pressure, T_{c} is rapidly enhanced beyond 10 K and stabilized at ca. 12 K over a wide pressure range up to 220 GPa. Synchrotron x-ray diffraction measurements evidenced no further structural phase transition, decomposition, and amorphization up to 155 GPa, implying an intrinsic superconductivity in the 2H_{a}-MoS_{2}. DFT calculations suggest that the emergence of pressure-induced superconductivity is intimately linked to the emergence of a new flat Fermi pocket in the electronic structure. Our finding represents an alternative strategy for achieving superconductivity in 2H-MoS_{2} in addition to chemical intercalation and electrostatic gating.

Microbial nitrogen removal of ammonia wastewater in poly (butylenes succinate)-based constructed wetland: effect of dissolved oxygen.

Constructed wetland (CW) is popular in wastewater treatment for its prominent advantage of low construction and operation cost. However, the nitrogen removal in conventional CW is usually limited by the low dissolved oxygen (DO) and insufficient electron donor. This paper investigated the nitrogen removal performance and mechanisms in the poly (butylenes succinate)-based CW (PBS-CW) while treating ammonia wastewater under different DO levels. The average DO contents in limited-aeration and full-aeration phases were 1.68 mg L-1 and 5.71 mg L-1, respectively. Results indicated that, with the ammonia nitrogen loading rate of 25 g N m-3 day-1, total nitrogen removal ratios in the PBS-CW under the limited-aeration and full-aeration phases were 72% and 99%, respectively. Combined analyses revealed that simultaneous nitrification and denitrification (SND) via nitrite/nitrate were the main microbial nitrogen removal pathways in the aeration phase of the PBS-CW (> 89%). The microbial carrier of biodegradable material was believed to play a significant role in prompting SND performance while dealing with low C/N wastewater. Due to the coexistence of micro-anaerobic zone and carbon supply inside the coated biofilm, the high DO level in the PBS-CW increased the abundance of the nitrifying bacteria (amoA and nxrA), denitrifying bacteria (narG, nirK, nirS, and nosZ), and even anammox bacteria (anammox 16s rRNA). These features are beneficial to many microbial processes which require the simultaneous aerobic, anoxic, and anaerobic environment.

Extended Polymorphism of Two-Dimensional Material.

When controlling electronic properties of bulk materials, we usually assume that the basic crystal structure is fixed. However, in two-dimensional (2D) materials, atomic structure or polymorph is attracting growing interest as a controlling parameter to functionalize their properties. Various polymorphs can exist in transition metal dichalcogenides (TMDCs) from which 2D materials are generated, and polymorphism has drastic impacts on the electronic states. Here we report the discovery of an unprecedented polymorph of a TMDC 2D material. By mechanical exfoliation, we made thin flakes from a single crystal of 2Ha-type tantalum disulfide (TaS2), a metallic TMDC with a charge-density-wave (CDW) phase. Microbeam X-ray diffraction measurements and electrical transport measurements indicate that thin flakes possess a polymorph different from any one known in TaS2 bulk crystals. Moreover, the flakes with the unique polymorph displayed the dramatically enhanced CDW ordering temperature. The present results suggest the potential existence of diverse structural and electronic phases accessible only in 2D materials.

EjNAC3 transcriptionally regulates chilling-induced lignification of loquat fruit via physical interaction with an atypical CAD-like gene.

Lignin is an important component of many plant secondary cell walls. In the fruit of loquat (Eriobotrya japonica), lignification of cell walls in the fleshy tissue occurs when fruit are subjected to low-temperature storage, which is commonly used to avoid the rapid senescence that occurs at room temperature. In this study, two NAC domain genes, EjNAC3 and EjNAC4, were isolated and shown to be significantly induced at 0 °C, which was concomitant with an increase in the fruit lignification index. Lignification and expression of both EjNAC3 and EjNAC4 were inhibited by low-temperature conditioning and by heat treatment. In addition, EjNAC3 trans-activated the lignin biosynthesis-related EjCAD-like promoter, which was measured using a dual-luciferase assay. Further analysis with yeast one-hybrid and electrophoretic mobility shift assays indicated that EjNAC3 could physically bind to the promoter of the EjCAD-like gene. Thus, EjNAC3 is a direct regulator of loquat chilling-induced lignification, via regulations of EjCAD-like.

Gate-Optimized Thermoelectric Power Factor in Ultrathin WSe2 Single Crystals.

We report an electric field tuning of the thermopower in ultrathin WSe2 single crystals over a wide range of carrier concentration by using electric double-layer (EDL) technique. We succeeded in the optimization of power factor not only in the hole but also in the electron side, which has never been chemically accessed. The maximized values of power factor are one-order larger than that obtained by changing chemical composition, reflecting the clean nature of electrostatic doping.

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.

Ambipolar MoS2 thin flake transistors.

Field effect transistors (FETs) made of thin flake single crystals isolated from layered materials have attracted growing interest since the success of graphene. Here, we report the fabrication of an electric double layer transistor (EDLT, a FET gated by ionic liquids) using a thin flake of MoS(2), a member of the transition metal dichalcogenides, an archetypal layered material. The EDLT of the thin flake MoS(2) unambiguously displayed ambipolar operation, in contrast to its commonly known bulk property as an n-type semiconductor. High-performance transistor operation characterized by a large "ON" state conductivity in the order of ~mS and a high on/off ratio >10(2) was realized for both hole and electron transport. Hall effect measurements revealed mobility of 44 and 86 cm(2) V(-1) s(-1) for electron and hole, respectively. The hole mobility is twice the value of the electron mobility, and the density of accumulated carrier reached 1 × 10(14) cm(-2), which is 1 order of magnitude larger than conventional FETs with solid dielectrics. The high-density carriers of both holes and electrons can create metallic transport in the MoS(2) channel. The present result is not only important for device applications with new functionalities, but the method itself would also act as a protocol to study this class of material for a broader scope of possibilities in accessing their unexplored properties.

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.

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.