Your browser doesn't support javascript.
loading
: 20 | 50 | 100
1 - 20 de 1.549
1.
Adv Mater ; : e2405030, 2024 May 29.
Article En | MEDLINE | ID: mdl-38808576

Neuromorphic visual systems can emulate biological retinal systems to perceive visual information under different levels of illumination, making them considerable potential for future intelligent vehicles and vision automation. However, the complex circuits and high operating voltages of conventional artificial vision systems present great challenges for device integration and power consumption. Here, we report bioinspired synaptic transistors based on organic single crystal phototransistors, which exhibit excitation and inhibition synaptic plasticity with time-varying. By manipulating the charge dynamics of the trapping centers of organic crystal-electret vertical stacks, organic transistors can operate below 1 V with record high on/off ratios close to 108 and sharp switching with a subthreshold swing of 59.8 mV dec-1. Moreover, the approach offers visual adaptation with highly localized modulation and over 98.2% recognition accuracy under different illumination levels. These bioinspired visual adaptation transistors offer great potential for simplifying the circuitry of artificial vision systems and will contribute to the development of machine vision applications. This article is protected by copyright. All rights reserved.

2.
Ann Rheum Dis ; 2024 May 08.
Article En | MEDLINE | ID: mdl-38724075

OBJECTIVE: Recent studies indicate that N-acetyltransferase 10 (NAT10)-mediated ac4C modification plays unique roles in tumour metastasis and immune infiltration. This study aimed to uncover the role of NAT10-mediated ac4C in fibroblast-like synoviocytes (FLSs) functions and synovial immune cell infiltration in rheumatoid arthritis (RA). METHODS: FLSs were obtained from active established patients with RA. Protein expression was determined by western blotting or immunohistochemistry or multiplexed immunohistochemistry. Cell migration was measured using a Boyden chamber. ac4C-RIP-seq combined with RNA-seq was performed to identify potential targets of NAT10. RNA immunoprecipitation was used to validate the interaction between protein and mRNA. NAT10 haploinsufficiency, inhibitor remodelin or intra-articular Adv-NAT10 was used to suppress arthritis in mice with delayed-type hypersensitivity arthritis (DYHA) and collagen II-induced arthritis (CIA) and rats with CIA. RESULTS: We found elevated levels of NAT10 and ac4C in FLSs and synovium from patients with RA. NAT10 knockdown or specific inhibitor treatment reduced the migration and invasion of RA FLSs. Increased NAT10 level in the synovium was positively correlated with synovial infiltration of multiple types of immune cells. NAT10 inhibition in vivo attenuated the severity of arthritis in mice with CIA and DTHA, and rats with CIA. Mechanistically, we explored that NAT10 regulated RA FLS functions by promoting stability and translation efficiency of N4-acetylated PTX3 mRNA. PTX3 also regulated RA FLS aggression and is associated with synovial immune cell infiltration. CONCLUSION: Our findings uncover the important roles of NAT10-mediated ac4C modification in promoting rheumatoid synovial aggression and inflammation, indicating that NAT10 may be a potential target for the treatment of RA, even other dysregulated FLSs-associated disorders.

3.
Article En | MEDLINE | ID: mdl-38769796

PURPOSE: To evaluate the postoperative outcomes of the all-inside technique in arthroscopic anterior cruciate ligament reconstruction (ACLR). METHODS: Patients who underwent ACLR using the all-inside technique between 2018 and 2021 were retrospectively assessed. All patients were followed up for at least 2 years. Functional recovery and pain relief were assessed using the International Knee Documentation Committee (IKDC) score, Lysholm score, Knee Injury and Osteoarthritis Outcome Score (KOOS) and visual analogue scale (VAS). Instrumented laxity was assessed via side-to-side difference using the Kneelax3 arthrometer. Graft maturity was estimated using the signal-to-noise quotient value based on magnetic resonance imaging (MRI). Adverse events during and after the surgery were recorded. RESULTS: A total of 78 patients were included in this study, with a mean age of 28.1 ± 7.6 years. The IKDC (p < 0.001), Lysholm (p < 0.001) and KOOS (p < 0.001 for all subgroups) scores at the final follow-up were significantly higher than those before the surgery. The VAS scores (p < 0.05) were significantly lower than those before surgery. The side-to-side difference results indicated that 50 patients had a difference of less than 3 mm, indicating a tight graft, whereas only 1 patient had a difference of >5 mm, indicating a loose graft. The median signal-to-noise quotient of the graft on MRI was 1.4 (P25, P75: 1.0, 2.0). No intraoperative adverse events were observed. Postoperative adverse events included three cases of infection, three cases of graft rerupture, two cases of cyclops lesion and one case of surgical intervention for a meniscal tear. CONCLUSION: ACLR using the all-inside technique offers promising results in patients with ACL rupture. LEVEL OF EVIDENCE: Level IV.

4.
Mol Psychiatry ; 2024 May 16.
Article En | MEDLINE | ID: mdl-38755244

Pre-existing psychiatric disorders were linked to an increased susceptibility to COVID-19 during the initial outbreak of the pandemic, while evidence during Omicron prevalence is lacking. Leveraging data from two prospective cohorts in China, we identified incident Omicron infections between January 2023 and April 2023. Participants with a self-reported history or self-rated symptoms of depression or anxiety before the Omicron pandemic were considered the exposed group, whereas the others were considered unexposed. We employed multivariate logistic regression models to examine the association of pre-existing depression or anxiety with the risk of any or severe Omicron infection indexed by medical interventions or severe symptoms. Further, we stratified the analyses by polygenic risk scores (PRSs) for COVID-19 and repeated the analyses using the UK Biobank data. We included 10,802 individuals from the Chinese cohorts (mean age = 51.1 years, 45.6% male), among whom 7841 (72.6%) were identified as cases of Omicron infection. No association was found between any pre-existing depression or anxiety and the overall risk of Omicron infection (odds ratio [OR] =1.04, 95% confidence interval [CI] 0.95-1.14). However, positive associations were noted for severe Omicron infection, either as infections requiring medical interventions (1.26, 1.02-1.54) or with severe symptoms (≥3: 1.73, 1.51-1.97). We obtained comparable estimates when stratified by COVID-19 PRS level. Additionally, using clustering method, we identified eight distinct symptom patterns and found associations between pre-existing depression or anxiety and the patterns characterized by multiple or complex severe symptoms including cough and taste and smell decline (ORs = 1.42-2.35). The results of the UK Biobank analyses corroborated findings of the Chinese cohorts. In conclusion, pre-existing depression and anxiety was not associated with the risk of Omicron infection overall but an elevated risk of severe Omicron infection, supporting the continued efforts on monitoring and possible early intervention in this high-risk population during Omicron prevalence.

5.
Chemistry ; : e202401250, 2024 May 05.
Article En | MEDLINE | ID: mdl-38705864

9,9-Dimethyl-9,10-dihydroacridine (DMAC) is one of the most widely used electron donor for constructing high-performance thermally activated delayed fluorescence (TADF) emitters. However, DMAC-based emitters often suffer from the imperfect color purity, particularly in blue emitters, due to its strong electron-donating capability. To modulate donor strength, 2,7-F-Ph-DMAC and 2,7-CF3-Ph-DMAC were designed by introducing the electron-withdrawing 2-fluorophenyl and 2-(trifluoromethyl)phenyl at the 2,7-positions of DMAC. These donors were used, in combination with 2,4,6-triphenyl-1,3,5-triazine (TRZ) acceptor, to develop novel TADF emitters 2,7-F-Ph-DMAC-TRZ and 2,7-CF3-Ph-DMAC-TRZ. Compared to the F- or CF3-free reference emitter, both two emitters showed hypsochromic effect in fluorescence and comparable photoluminescence quantum yields without sacrificing the reverse intersystem crossing rate constants. In particular, 2,7-CF3-Ph-DMAC-TRZ based OLED exhibited a blue shift by up to 39 nm and significantly improved Commission International de l'Éclairage (CIE) coordinates from (0.36, 0.55) to (0.22, 0.41), while the external quantum efficiency kept stable at about 22.5 %. This donor engineering strategy should be valid for improving the color purity of large amount of acridine based TADF emitters. It can be predicted that pure blue TADF emitters should be feasible if these F- or CF3-modifed acridine donors are combined with other weaker electron acceptors.

6.
Food Funct ; 2024 May 24.
Article En | MEDLINE | ID: mdl-38787733

Bioactive oligopeptides have gained increasing attention due to their diverse physiological functions, and these can be transported into the vasculature via transcellular and paracellular pathways. Among these, paracellular transport through the intercellular space is a passive diffusion process without energy consumption. It is currently the most frequently reported absorption route for food-derived bioactive oligopeptides. Previous work has demonstrated that paracellular pathways are mainly controlled by tight junctions, but the mechanism by which they regulate paracellular absorption of bioactive oligopeptides remains unclear. In this review, we summarized the composition of paracellular pathways across the intercellular space and elaborated on the paracellular transport mechanism of bioactive oligopeptides in terms of the interaction between oligopeptides and tight junction proteins, the protein expression level of tight junctions, the signaling pathways regulating intestinal permeability, and the properties of oligopeptides themselves. These findings contribute to a more profound understanding of the paracellular absorption of bioactive oligopeptides.

7.
Curr Issues Mol Biol ; 46(5): 3866-3876, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38785508

Cold stress significantly affects gene expression in adipocytes; studying this phenomenon can help reveal the pathogeneses of conditions such as obesity and insulin resistance. Adipocyte triglyceride lipase (ATGL); cell death-inducing deoxyribonucleic acid (DNA) fragmentation factor subunit alpha (DFFA)-like effector (CIDEA); and uncoupling protein genes UCP1, UCP2, and UCP3 are the most studied genes in pig adipose tissues under cold stress. However, contradictory results have been observed in gene expression changes to UCP3 and UCP2 when adipose tissues under cold stress were examined. Therefore, we conducted a meta-analysis of 32 publications in total on the effect of cold stress on the expression of ATGL, CIDEA, UCP2, and UCP3. Our results showed that cold stress affected the expression of swine adipocyte genes; specifically, it was positively correlated with the expression of UCP3 in swine adipocytes. Conversely, expression of ATGL was negatively affected under cold stress conditions. In addition, the loss of functional UCP1 in pigs likely triggered a compensatory increase in UCP3 activity. We also simulated the docking results of UCP2 and UCP3. Our results showed that UCP2 could strongly bind to adenosine triphosphate (ATP), meaning that UCP3 played a more significant role in pig adipocytes.

9.
Nat Commun ; 15(1): 4167, 2024 May 16.
Article En | MEDLINE | ID: mdl-38755131

Mechanical energy harvesting using triboelectric nanogenerators is a highly desirable and sustainable method for the reliable power supply of widely distributed electronics in the new era; however, its practical viability is seriously challenged by the limited performance because of the inevitable side-discharge and low Coulombic-efficiency issues arising from electrostatic breakdown. Here, we report an important progress on these fundamental problems that the spontaneously established reverse electric field between the electrode and triboelectric layer can restrict the side-discharge problem in triboelectric nanogenerators. The demonstration employed by direct-current triboelectric nanogenerators leads to a high Coulombic efficiency (increased from 28.2% to 94.8%) and substantial enhancement of output power. More importantly, we demonstrate this strategy is universal for other mode triboelectric nanogenerators, and a record-high average power density of 6.15 W m-2 Hz-1 is realized. Furthermore, Coulombic efficiency is verified as a new figure-of-merit to quantitatively evaluate the practical performance of triboelectric nanogenerators.

10.
Open Biol ; 14(5): 230358, 2024 May.
Article En | MEDLINE | ID: mdl-38689555

The nucleolus is the most prominent liquid droplet-like membrane-less organelle in mammalian cells. Unlike the nucleolus in terminally differentiated somatic cells, those in totipotent cells, such as murine zygotes or two-cell embryos, have a unique nucleolar structure known as nucleolus precursor bodies (NPBs). Previously, it was widely accepted that NPBs in zygotes are simply passive repositories of materials that will be gradually used to construct a fully functional nucleolus after zygotic genome activation (ZGA). However, recent research studies have challenged this simplistic view and demonstrated that functions of the NPBs go beyond ribosome biogenesis. In this review, we provide a snapshot of the functions of NPBs in zygotes and early two-cell embryos in mice. We propose that these membrane-less organelles function as a regulatory hub for chromatin organization. On the one hand, NPBs provide the structural platform for centric and pericentric chromatin remodelling. On the other hand, the dynamic changes in nucleolar structure control the release of the pioneer factors (i.e. double homeobox (Dux)). It appears that during transition from totipotency to pluripotency, decline of totipotency and initiation of fully functional nucleolus formation are not independent events but are interconnected. Consequently, it is reasonable to hypothesize that dissecting more unknown functions of NPBs may shed more light on the enigmas of early embryonic development and may ultimately provide novel approaches to improve reprogramming efficiency.


Cell Nucleolus , Chromatin , Embryonic Development , Animals , Humans , Mice , Cell Nucleolus/metabolism , Chromatin/metabolism , Chromatin Assembly and Disassembly , Gene Expression Regulation, Developmental , Zygote/metabolism , Zygote/cytology
11.
J Colloid Interface Sci ; 671: 434-440, 2024 May 25.
Article En | MEDLINE | ID: mdl-38815378

Photoelectrochemical (PEC) water splitting is an effective and sustainable method for solar energy harvesting. However, the technology is still far away from practical application because of the high cost and low efficiency. Here, we report a low-cost, stable and high-performing industrial-Si-based photoanode (n-Indus-Si/Co-2mA-xs) that is fabricated by simple electrodeposition. Systematic characterizations such as scanning electron microscopy, X-ray photoelectron spectroscopy have been employed to characterize and understand the working mechanisms of this photoanode. The uniform and adherent dispersion of co-catalyst particles result in high built-in electric field, reduced charge transfer resistance, and abundant active sites. The core-shell structure of co-catalyst particles is formed after the activation process. The reconstructed morphology and modified chemical states of the surface co-catalyst particles improve the separation and transfer of charges, and the reaction kinetics for water oxidation greatly. Our work demonstrates that large-scale PEC water splitting can be achieved by engineering the industrial-Si-based photoelectrode, which shall guide the development of solar energy conversion in the industry.

12.
Sci Rep ; 14(1): 10471, 2024 05 07.
Article En | MEDLINE | ID: mdl-38714840

Lung diseases globally impose a significant pathological burden and mortality rate, particularly the differential diagnosis between adenocarcinoma, squamous cell carcinoma, and small cell lung carcinoma, which is paramount in determining optimal treatment strategies and improving clinical prognoses. Faced with the challenge of improving diagnostic precision and stability, this study has developed an innovative deep learning-based model. This model employs a Feature Pyramid Network (FPN) and Squeeze-and-Excitation (SE) modules combined with a Residual Network (ResNet18), to enhance the processing capabilities for complex images and conduct multi-scale analysis of each channel's importance in classifying lung cancer. Moreover, the performance of the model is further enhanced by employing knowledge distillation from larger teacher models to more compact student models. Subjected to rigorous five-fold cross-validation, our model outperforms existing models on all performance metrics, exhibiting exceptional diagnostic accuracy. Ablation studies on various model components have verified that each addition effectively improves model performance, achieving an average accuracy of 98.84% and a Matthews Correlation Coefficient (MCC) of 98.83%. Collectively, the results indicate that our model significantly improves the accuracy of disease diagnosis, providing physicians with more precise clinical decision-making support.


Deep Learning , Lung Neoplasms , Neural Networks, Computer , Humans , Lung Neoplasms/pathology , Lung Neoplasms/diagnosis , Lung Neoplasms/classification , Small Cell Lung Carcinoma/diagnosis , Small Cell Lung Carcinoma/pathology , Small Cell Lung Carcinoma/classification , Carcinoma, Squamous Cell/diagnosis , Carcinoma, Squamous Cell/pathology , Adenocarcinoma/pathology , Adenocarcinoma/diagnosis , Adenocarcinoma/classification , Image Processing, Computer-Assisted/methods , Diagnosis, Differential
13.
Sci Data ; 11(1): 492, 2024 May 14.
Article En | MEDLINE | ID: mdl-38744849

Surface ozone is an important air pollutant detrimental to human health and vegetation productivity, particularly in China. However, high resolution surface ozone concentration data is still lacking, largely hindering accurate assessment of associated environmental impacts. Here, we collected hourly ground ozone observations (over 6 million records), remote sensing products, meteorological data, and social-economic information, and applied recurrent neural networks to map hourly surface ozone data (HrSOD) at a 0.1° × 0.1° resolution across China during 2015-2020. The coefficient of determination (R2) values in sample-based, site-based, and by-year cross-validations were 0.72, 0.65 and 0.71, respectively, with the root mean square error (RMSE) values being 11.71 ppb (mean = 30.89 ppb), 12.81 ppb (mean = 30.96 ppb) and 11.14 ppb (mean = 31.26 ppb). Moreover, it exhibits high spatiotemporal consistency with ground-level observations at different time scales (diurnal, seasonal, annual), and at various spatial levels (individual sites and regional scales). Meanwhile, the HrSOD provides critical information for fine-resolution assessment of surface ozone impacts on environmental and human benefits.

14.
Metabolites ; 14(5)2024 Apr 27.
Article En | MEDLINE | ID: mdl-38786732

The role of metabolic traits in ischemic stroke (IS) has been explored through observational studies and a few Mendelian randomization (MR) studies employing limited methods in European populations. This study aimed to investigate the causal effects of metabolic traits on IS in both East Asian and European populations utilizing multiple MR methods based on genetic insights. Two-sample and multivariable MR were performed, and MR estimates were calculated as inverse-variance weighted (IVW), weighted median, and penalized weighted median. Pleiotropy was assessed by MR-Egger and Mendelian randomization pleiotropy residual sum and outlier tests. Systolic blood pressure (SBP) was associated with an increased risk of IS by IVW in both European (ORIVW: 1.032, 95% CI: 1.026-1.038, p < 0.001) and Japanese populations (ORIVW: 1.870, 95% CI: 1.122-3.116, p = 0.016), which was further confirmed by other methods. Unlike the European population, the evidence for the association of diastolic blood pressure (DBP) with IS in the Japanese population was not stable. No evidence supported an association between the other traits and IS (all Ps > 0.05) in both races. A positive association was found between SBP and IS in two races, while the results of DBP were only robust in Europeans.

15.
Food Chem X ; 22: 101336, 2024 Jun 30.
Article En | MEDLINE | ID: mdl-38623514

Ochratoxin A (OTA) contamination in grape juice has attracted widespread concern as OTA can lead to kidney disease and cause adverse neurological effects. An effective method to remove OTA is to make use of highly adsorbent materials that are able to remove the toxic contaminant. Recently, inactivated Lactobacillus plantarum-based biosorbents have shown to be an efficient, cost-effective and environmentally friendly bioremediation method in removing toxic pollutants such as OTA. We used five chemical thiol-modification methods to improve the adsorption efficiency of OTA in grape juice. The esterification of Lactobacillus plantarum (L-Es) significantly increased the sulfhydryl contents (-SH) by 251.33 µmol/g and >90% of OTA was removed. However, the inactivated microbial adsorbent was difficult to separate after adsorption and therefore, the prepared L-Es were embedded into the cellulose nanocrystals (L-Es@CNCs). Moreover, L-Es@CNCs significantly increased the adsorption rate of OTA in grape juice samples by 88.28% with negligible effects on juice quality due to the properties of easy re-use and excellent biodegradability. This showcases its potential application for OTA removal in the grape juice industry.

16.
J Phys Chem A ; 128(16): 3170-3179, 2024 Apr 25.
Article En | MEDLINE | ID: mdl-38624170

We perform a high-level ab initio study on 20 electronic states of monochlorosilylene (HSiCl) using an internally contracted multireference configuration interaction method including Davidson correction (icMRCI+Q). The spin-orbit coupling (SOC) effect is investigated, leading to splitting of the 20 spin-orbit-free states into 50 spin-orbit-coupled states. Vertical transition energies, oscillator strengths, and potential energy curves are presented with and without considering the SOC effect. Analysis indicates that the SOC effect plays an important role, especially for the high-lying excited states of HSiCl. The state interaction and the dynamics of the electronic states of HSiCl in the ultraviolet region are discussed based on our calculation results. Our study paves the way to understanding the behavior of electronic excited states of monochlorosilylene.

17.
Clin Breast Cancer ; 2024 Mar 08.
Article En | MEDLINE | ID: mdl-38670862

BACKGROUND: The combination of neoadjuvant chemotherapy and anti-angiogenesis therapy for patients with triple-negative breast cancer (TNBC) remains inadequately supported by evidence. We conducted a single-arm, open-label, multicenter, phase II trial to evaluate the efficacy and toxicity of anlotinib plus epirubicin and cyclophosphamide followed by paclitaxel in patients with IIB to IIIA stage TNBC. METHODS: Newly diagnosed patients received epirubicin at 90 mg/m2 and cyclophosphamide at 600 mg/m2 followed by docetaxel at 100 mg/m2 (21 days per cycle; total of 4 cycles), along with oral anlotinib (12 mg qd, d1-14; 21 days per cycle; total of 4 cycles). Subsequently, patients underwent surgery. The primary endpoint of this study was pathologic complete response (pCR). RESULTS: Among the 34 included patients, the median age was 46.5 years (range: 27-72); all were female. Pathological assessment revealed that 17 patients achieved RCB 0 response, which is currently defined as pathologic complete response; 3 patients achieved RCB 1; 12 patients achieved RCB 2; and 1 patient achieved RCB 3. The probability of a grade 3 adverse reaction was 17.6%, and no grade 4 adverse reactions occurred. The most common hematological adverse reaction was leukopenia (13/34, 38.2%), of which 5.9% (2/34) were grade 3. The most common non-hematological adverse reactions were oral mucositis (16/34, 58.8%), fatigue (50.0%), hand-foot syndrome (50.0%), hypertension (44.1%), bleeding (44.1%), and alopecia (32.4%). CONCLUSION: The combination of anlotinib and EC-T chemotherapy demonstrated tolerable side effects in the neoadjuvant treatment of early TNBC. pCR was higher than what has been reported in previous clinical studies of chemotherapy alone. This study provides additional rationale for using anlotinib plus docetaxel-epirubicin-based chemotherapy regimen in patients with early-stage TNBCs.

18.
Sci Total Environ ; 929: 172405, 2024 Jun 15.
Article En | MEDLINE | ID: mdl-38626822

Significant spatial variability of groundwater arsenic (As) concentrations in South/Southeast Asia is closely associated with sedimentogenesis and biogeochemical cycling processes. However, the role of fine-scale differences in biogeochemical processes under similar sedimentological environments in controlling the spatial heterogeneity of groundwater As concentrations is poorly understood. Within the central Yangtze Basin, dissolved organic matter (DOM) and microbial functional communities in the groundwater and solid-phase As-Fe speciation in Jianghan Plain (JHP) and Jiangbei Plain (JBP) were compared to reveal mechanisms related to the spatial heterogeneity of groundwater As concentration. The optical signatures of DOM showed that low molecular terrestrial fulvic-like with highly humified was predominant in the groundwater of JHP, while terrestrial humic-like and microbial humic-like with high molecular weight were predominant in the groundwater of JBP. The inorganic carbon isotope, microbial functional communities, and solid-phase As-Fe speciation suggest that the primary process controlling As accumulation in JHP groundwater system is the degradation of highly humified OM by methanogens, which drive the reductive dissolution of amorphous iron oxides. While in JBP groundwater systems, anaerobic methane-oxidizing microorganisms (AOM) coupled with fermentative bacteria, iron reduction bacteria (IRB), and sulfate reduction bacteria (SRB) utilize low molecular weight DOM degradation to drive biotic/abiotic reduction of Fe oxides, further facilitating the formation of carbonate associated Fe and crystalline Fe oxides, resulting in As release into groundwater. Different biogeochemical cycling processes determine the evolution of As-enriched aquifer systems, and the coupling of multiple processes involving organic matter transformation­iron cycling­sulfur cycling-methane cycling leads to heterogeneity in the spatial distribution of As concentrations in groundwater. These findings provide new perspectives to decipher the spatial variability of As concentrations in groundwater.


Arsenic , Environmental Monitoring , Groundwater , Water Pollutants, Chemical , Groundwater/chemistry , Arsenic/analysis , Water Pollutants, Chemical/analysis , China , Rivers/chemistry
19.
Heliyon ; 10(7): e28579, 2024 Apr 15.
Article En | MEDLINE | ID: mdl-38560102

To evaluate the performance of online teaching during the COVID-19 period, we collected 1886 survey data from college students in Hubei Province, China. The scoring rules of the Framework for Teaching were used to measure college students' satisfaction with online teaching, and an econometric model was constructed to empirically validate its dynamic influences. We found that college students' satisfaction with online teaching during the COVID-19 pandemic was lower than that with offline teaching. Online teaching satisfaction was significantly affected by variables of class size, proportion of online teaching, epidemic severity, college grade, network, course classification, major classification, and the teacher's age and skills. It was further found that as COVID-19 gradually dissipated, offline teaching should be resumed as soon as possible. These findings objectively evaluate the teaching performance of college students during the COVID-19 pandemic and can provide suggestions for optimizing online teaching during future emergencies.

20.
J Colloid Interface Sci ; 666: 118-130, 2024 Jul 15.
Article En | MEDLINE | ID: mdl-38588624

The phenol-formaldehyde (PF) resin is an economical precursor for spherical hard carbon (HC) anodes for sodium-ion batteries (SIBs). However, achieving precise molecular-level control of PF-based HC microspheres, particularly for optimizing ion transport microstructure, is challenging. Here, a sodium linoleate (SL)-assisted strategy is proposed to enable molecular-level engineering of PF-based HC microspheres. PF microspheres are synthesized through the polymerization of 3-aminophenol and formaldehyde, initially forming oxazine rings and then undergoing ring-opening polymerization to create a macromolecular network. SL functions as both a surfactant to control microsphere size and a catalyst to enhance ring-opening polymerization and increase polymerization of PF resin. These modifications lead to reduced microsphere diameter, increased interlayer spacing, enhanced graphitization, and significantly improved electron and ion transfer. The synthesized HC microspheres exhibit a remarkable reversible capacity of 337 mAh/g, maintaining 96.9 mAh/g even at a high current density of 5.0 A/g. Furthermore, the full cell demonstrates a high capacity of 150 mAh/g, an energy density of 125.3 Wh kg-1, an impressive initial coulombic efficiency (ICE) of 930.3% at 1 A/g, and remarkable long-term stability over 3000 cycles. This study highlights the potential of surfactant-assisted molecular-level engineering in customizing HC microspheres for advanced SIBs.

...