311 research outputs found

    Unusual pressure-induced electronic structure evolution in organometal halide perovskite predicted from first-principles

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    Pressure has been demonstrated to be an effective parameter to alter the atomic and electronic structures of materials. By using the first-principles calculations based on density functional theory (DFT), we systematically investigated the changes in the atomic and electronic structures of the cubic MAPbI(3) phase under pressures. It is found that the band gap of the compressed cubic MAPbI(3) structure exhibits a remarkable redshift to 1.114/1.380 eV in DFT/HSE-SOC calculation under a mild pressure of 2.772 GPa, and subsequently shows a widening at higher pressures until similar to 20 GPa. As the pressure further increases, the band gap closes at similar to 80 GPa. Detailed structural and electronic characteristic analyses indicate that the band gap of the cubic MAPbI(3) structure is determined by two competing effects: the lattice contraction decreases its band gap while the PbI6 octahedral filling increases it. Given that, pressure can be a powerful tool to help understanding the optoelectronic properties of perovskite materials

    A new type of simplified inverse Lax-Wendroff boundary treatment I: hyperbolic conservation laws

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    In this paper, we design a new kind of high order inverse Lax-Wendroff (ILW) boundary treatment for solving hyperbolic conservation laws with finite difference method on a Cartesian mesh. This new ILW method decomposes the construction of ghost point values near inflow boundary into two steps: interpolation and extrapolation. At first, we impose values of some artificial auxiliary points through a polynomial interpolating the interior points near the boundary. Then, we will construct a Hermite extrapolation based on those auxiliary point values and the spatial derivatives at boundary obtained via the ILW procedure. This polynomial will give us the approximation to the ghost point value. By an appropriate selection of those artificial auxiliary points, high-order accuracy and stable results can be achieved. Moreover, theoretical analysis indicates that comparing with the original ILW method, especially for higher order accuracy, the new proposed one would require fewer terms using the relatively complicated ILW procedure and thus improve computational efficiency on the premise of maintaining accuracy and stability. We perform numerical experiments on several benchmarks, including one- and two-dimensional scalar equations and systems. The robustness and efficiency of the proposed scheme is numerically verified

    Sleep Problems in Children With ADHD: Associations with Internalizing Symptoms and Physical Activity

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    Children with attention deficit hyperactivity disorder (ADHD) experience high rates of sleep problems and are at increased risk for developing internalizing problems. This study aimed to examine the association of sleep problems and physical activity with internalizing symptoms in children with ADHD. This cross-sectional study included 188 children with ADHD (M age = 8.60 ± 1.38, 78.7% boys). Self-reported questionnaires were used to assess sleep problems (Pittsburgh Sleep Quality Index [PSQI]) and internalizing symptoms (Depression Anxiety Stress Scale 21 [DASS 21]). The presence of sleep problems was defined as a PSQI score \u3e 5. Physical activity was recorded by an ActiGraph GT9X Link accelerometer for 7 consecutive days. In total, 111 children with ADHD presented with sleep problems (59%). Compared with their counterparts without sleep problems, children with sleep problems spent less time in daily moderator-to-vigorous physical activity (MVPA) (F = 15.35, η2 = .079), had a lower proportion of meeting the WHO-recommended 60 min of daily MVPA guideline (F = 9.57, η2 = .050), and showed more internalizing symptoms: depression (F = 10.09, η2 = .053), anxiety (F = 15.84, η2 = .081), and stress (F = 6.98, η2 = .037). BMI, daytime dysfunction of PSQI, and MVPA guideline attainment were significantly associated with internalizing symptoms in children with ADHD. Daytime dysfunction of PSQI is associated with more severe internalizing symptoms, and MVPA guideline attainment may reduce the likelihood of developing depression and anxiety in children with ADHD. Future studies are needed to examine the long-term effects of sleep on internalizing symptoms and the effects of PA-based interventions on sleep and internalizing symptoms in children with ADHD, respectively

    Exploring the pathogenesis of colorectal carcinoma complicated with hepatocellular carcinoma via microarray data analysis

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    Background: Despite the increasing number of research endeavors dedicated to investigating the relationship between colorectal carcinoma (CRC) and hepatocellular carcinoma (HCC), the underlying pathogenic mechanism remains largely elusive. The aim of this study is to shed light on the molecular mechanism involved in the development of this comorbidity.Methods: The gene expression profiles of CRC (GSE90627) and HCC (GSE45267) were downloaded from the Gene Expression Omnibus (GEO) database. After identifying the common differentially expressed genes (DEGs) of psoriasis and atherosclerosis, three kinds of analyses were performed, namely, functional annotation, protein‐protein interaction (PPI) network and module construction, and hub gene identification, survival analysis and co-expression analysis.Results: A total of 150 common downregulated differentially expressed genes and 148 upregulated differentially expressed genes were selected for subsequent analyses. The significance of chemokines and cytokines in the pathogenesis of these two ailments is underscored by functional analysis. Seven gene modules that were closely connected were identified. Moreover, the lipopolysaccharide-mediated signaling pathway is intricately linked to the development of both diseases. Finally, 10 important hub genes were identified using cytoHubba, including CDK1, KIF11, CDC20, CCNA2, TOP2A, CCNB1, NUSAP1, BUB1B, ASPM, and MAD2L1.Conclusion: Our study reveals the common pathogenesis of colorectal carcinoma and hepatocellular carcinoma. These common pathways and hub genes may provide new ideas for further mechanism research

    Effect of Core Values of General Practice on Adherence of Patients with Diabetes

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    BackgroundTreatment adherence is closely related to disease control for patients with diabetes. Primary care is general, and continuous, which may satisfy the general and continuous healthcare needs of diabetic patients. But the association of core values of general practices with adherence of diabetic patients is not yet clear.ObjectiveTo explore the effect of core values of general practice (first contact/first line care, continuity, accessibility, comprehensiveness, coordination and patient-oriented) on the adherence (medication adherence, diet adherence, exercise adherence, self-monitoring adherence and regular hospital visits adherence) of type 2 diabetic patients, providing a reference for improving the adherence of such patients by precisely enhancing the core values of general practices.MethodsA survey was conducted between August and September 2019 with a convenience sample of type 2 diabetics receiving contacted family doctor services from Shayuan Community Health Center of Guangzhou using a questionnaire consisting of three parts〔demographic information, the Chinese version of Primary Care Assessment Survey (ASPC) , and Adherence to Out-of-hospital Treatment of Type 2 Diabetics (AOTTD) 〕. Treatment adherence was compared by various personal factors. Multiple linear regression was used to analyze the association of the core values of general practice with treatment adherence.ResultsAltogether, 224 cases who handed in responsive questionnaires were included for final analysis. The average scores of AOTTD, and ASPC of the respondents were (80.57±11.27) and (72.95±11.40) , respectively. The scores of AOTTD differed significantly by sex and understanding level of type 2 diabetes (P<0.05) . The total score of ASPC and the score of its each domain were associated with the total score of AOTTD, or the domain score of regular hospital visits (P<0.10) . The scores of two domains (accessibility and coordination) of the ASPC were associated with the medication adherence score (P<0.10) . The domain score of coordination was associated with the diet adherence score (P<0.10) . The score of each domain of the ASPC (except for coordination) was associated with the self-monitoring adherence score (P<0.10) .ConclusionFor type 2 diabetics, strengthening each of the core values of general practice could contribute to the increase of their treatment adherence, and regular hospital visits adherence. Improving the accessibility of general practice could enhance their medication adherence. Improving the coordination of general practice could enhance their medication adherence and diet adherence. Improving first contact/first line care, continuity, accessibility, comprehensiveness, coordination and patient-oriented values of general practice could contribute to the increase of their medication adherence. But no association was found between the core values of general practice and patients'exercise adherence, which suggests that providing more exercise resources and environmental support for these patients may be a solution

    An Empirical Study and Analysis of Text-to-Image Generation Using Large Language Model-Powered Textual Representation

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    One critical prerequisite for faithful text-to-image generation is the accurate understanding of text inputs. Existing methods leverage the text encoder of the CLIP model to represent input prompts. However, the pre-trained CLIP model can merely encode English with a maximum token length of 77. Moreover, the model capacity of the text encoder from CLIP is relatively limited compared to Large Language Models (LLMs), which offer multilingual input, accommodate longer context, and achieve superior text representation. In this paper, we investigate LLMs as the text encoder to improve the language understanding in text-to-image generation. Unfortunately, training text-to-image generative model with LLMs from scratch demands significant computational resources and data. To this end, we introduce a three-stage training pipeline that effectively and efficiently integrates the existing text-to-image model with LLMs. Specifically, we propose a lightweight adapter that enables fast training of the text-to-image model using the textual representations from LLMs. Extensive experiments demonstrate that our model supports not only multilingual but also longer input context with superior image generation quality.To appear in ECCV-2024, Project page: https://llm-conditioned-diffusion.github.io

    Mining Magnaporthe oryzae sRNAs With Potential Transboundary Regulation of Rice Genes Associated With Growth and Defense Through Expression Profile Analysis of the Pathogen-Infected Rice

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    In recent years, studies have shown that phytopathogenic fungi possess the ability of cross-kingdom regulation of host plants through small RNAs (sRNAs). Magnaporthe oryzae, a causative agent of rice blast, introduces disease by penetrating the rice tissues through appressoria. However, little is known about the transboundary regulation of M. oryzae sRNAs during the interaction of the pathogen with its host rice. Therefore, investigation of the regulation of M. oryzae through sRNAs in the infected rice plants has important theoretical and practical significance for disease control and production improvement. Based on the high-throughput data of M. oryzae sRNAs and the mixed sRNAs during infection, the differential expressions of sRNAs in M. oryzae before and during infection were compared, it was found that expression levels of 366 M. oryzae sRNAs were upregulated significantly during infection. We trained a SVM model which can be used to predict differentially expressed sRNAs, which has reference significance for the prediction of differentially expressed sRNAs of M. oryzae homologous species, and can facilitate the research of M. oryzae in the future. Furthermore, fifty core targets were selected from the predicted target genes on rice for functional enrichment analysis, the analysis reveals that there are nine biological processes and one KEGG pathway associated with rice growth and disease defense. These functions correspond to thirteen rice genes. A total of fourteen M. oryzae sRNAs targeting the rice genes were identified by data analysis, and their authenticity was verified in the database of M. oryzae sRNAs. The 14 M. oryzae sRNAs may participate in the transboundary regulation process and act as sRNA effectors to manipulate the rice blast process

    Exceptional electrostrain with minimal hysteresis and superior temperature stability under low electric field in KNN-based lead-free piezoceramics

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    Over the past two decades, (K0.5Na0.5)NbO3 (KNN)-based lead-free piezoelectric ceramics have made significant progress. However, attaining a high electrostrain with remarkable temperature stability and minimal hysteresis under low electric fields has remained a significant challenge. To address this long-standing issue, we have employed a collaborative approach that combines defect engineering, phase engineering, and relaxation engineering. The LKNNS-6BZH ceramic, when sintered at Tsint = 1170 ℃, demonstrates an impressive electrostrain with a d33∗ value of 0.276% and 1379 pm·V–1 under 20 kV·cm–1, which is comparable to or even surpasses that of other lead-free and Pb(Zr,Ti)O3 ceramics. Importantly, the electrostrain performance of this ceramic remains stable up to a temperature of 125 ℃, with the lowest hysteresis observed at 9.73% under 40 kV·cm–1. These excellent overall performances are attributed to the presence of defect dipoles involving VA′–VO∙∙ and BNb′–VO∙∙, the coexistence of R–O–T multiphase, and the tuning of the trade-off between long-range ordering and local heterogeneity. This work provides a lead-free alternative for piezoelectric actuators and a paradigm for designing piezoelectric materials with outstanding comprehensive performance under low electric fields

    Waning neutralizing antibodies through 180 days after homologous and heterologous boosters of inactivated COVID-19 vaccine

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    To enhance the personal immunity to COVID-19, a third booster dose of inactivated COVID-19 vaccines program campaign was implemented in China. Our study endeavored to compare the dynamics of neutralizing antibodies generated by four distinct booster vaccines against three kinds of live SARS-CoV-2 virus (wild-type, Delta AY.23, and Omicron BA5.2). This cohort study involved 320 healthy individuals, who were randomly assigned to four groups, to receive boosters with inactivated vaccine (COVac and BIBP), the adenovirus type-5-vectored vaccine (Convidecia), and the recombinant protein-based vaccine (Zifivax), respectively, all the vaccines studied had the Wuhan variant as their parental variant. Participants were recruited from December 2021 to June 2022, with a follow-up period of 180 days. We evaluated humoral immune responses and their longevity by measuring the geometric mean titers (GMTs) of neutralizing antibodies against the SARS-CoV-2 virus at various time points post-boost. After 180 days of follow-up, 310 participants completed the study. Across all booster groups, neutralizing antibodies against the wild-type virus declined sharply within the first 90 days, accounting for an 81.24 to 92.34% reduction, then slowed down with gradually decreasing decay rates. By day 14 of post-boost, the ability to neutralize the Delta variant slightly diminished compared to the wild-type, whereas neutralizing antibodies against the Omicron variant exhibited a more pronounced decline, ranging from 10.78 to 19.88 times lower than those against the wild-type. Notably, heterologous boosting with the Convidecia vaccine maintained higher GMTs of neutralizing antibodies against both Delta and Omicron variants compared to the other boosters. At 180 days of post-boost, GMTs of neutralizing antibodies against SARS-CoV-2 had substantially decreased, yet individuals who received the Convidecia vaccine still exhibited higher titers than those who received other boosters. In summary, neutralizing antibody levels significantly waned 180 days after the third vaccine dose, with the most pronounced decline occurring within the initial 90 days. Heterologous boosting with Convidecia demonstrated a more robust, durable, and broad humoral immune response compared to boosting with inactivated vaccines or Zifivax, suggesting that adenovirus vector vaccines possess a special advantage in the realm of vaccine development for preventing infectious diseases

    Identification of candidate gene for the defective kernel phenotype using bulked segregant RNA and exome capture sequencing methods in wheat

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    Wheat is a significant source of protein and starch worldwide. The defective kernel (Dek) mutant AK-3537, displaying a large hollow area in the endosperm and shrunken grain, was obtained through ethyl methane sulfonate (EMS) treatment of the wheat cultivar Aikang 58 (AK58). The mode of inheritance of the AK-3537 grain Dek phenotype was determined to be recessive with a specific statistical significance level. We used bulked segregant RNA-seq (BSR-seq), BSA-based exome capture sequencing (BSE-seq), and the ΔSNP-index algorithm to identify candidate regions for the grain Dek phenotype. Two major candidate regions, DCR1 (Dek candidate region 1) and DCR2, were identified on chromosome 7A between 279.98 and 287.93 Mb and 565.34 and 568.59 Mb, respectively. Based on transcriptome analysis and previous reports, we designed KASP genotyping assays based on SNP variations in the candidate regions and speculated that the candidate gene is TraesCS7A03G0625900 (HMGS-7A), which encodes a 3-hydroxy-3-methylglutaryl-CoA synthase. One SNP variation located at position 1,049 in the coding sequence (G>A) causes an amino acid change from Gly to Asp. The research suggests that functional changes in HMGS-7A may affect the expression of key enzyme genes involved in wheat starch syntheses, such as GBSSII and SSIIIa
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