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Semiconducting fibers (SCFs) are of significant interest to design next-generation wearable and comfortable optoelectronics that seamlessly integrate with textiles. However, the practical applications of current SCFs are always limited by poor optoelectronic performance and low mechanical robustness caused by uncontrollable multiscale structural defects. Herein, a versatile in situ molecular soldering-governed defect engineering strategy is proposed to construct ultrahigh responsivity and robust wet-spun MoS2 SCFs, by using a π-conjugated dithiolated molecule to simultaneously patch microscale sulfur vacancies within MoS2 nanosheets, diminish mesoscale interlayer voids/wrinkles, promote macroscale orientation, build long-range photoelectron percolation bridges, and provide n-doping effect. The derived MoS2 SCFs exhibit over two orders of magnitude higher responsivity (144.3 A W-1) than previously reported fiber photodetectors, 37.3-fold faster photoresponse speed (52 ms) than pristine counterpart, and remarkable bending robustness (retain 94.2% of the initial photocurrent after 50 000 bending-flattening cycles). Such superior robustness and photodetection capacity of MoS2 SCFs further enable large-scale weaving of reliable smart textile optoelectronic systems, such as direction-identifiable wireless light alarming system, modularized mechano-optical communication system, and indoor light-controlled IoT system. This work offers a universal strategy for the scalable production of mechanically robust and high-performance SCFs, opening up exciting possibilities for large-scale integration of wearable optoelectronics.
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BACKGROUND: Medical research in complementary and alternative medicine (CAM) has increased recently, raising ethical concerns about the moral status of CAM. Medical academic journals are responsible for conducting ethical review (ER) of manuscripts to protect the interests of human subjects and to make ethical results available before deciding to publish. However, there has been no systematic analysis of the ER in CAM journals. This study is aim to evaluate the current status of ethical requirements and compliance in CAM journals. METHODS: This is a cross-sectional study. We reviewed instructions for authors (IFAs) of CAM journals included in the Journal Citation Reports (2021) ( https://jcr.clarivate.com ) for general information and requirements for ER. We also browsed the manuscripts regarding randomized controlled trials published by CAM journals in Q1 and Q2 section from January to June, 2023, to check the actual situation of ethical requirement. Descriptive statistics and Fisher's exact test were used for statistical analysis. RESULTS: 27 journals and 68 manuscripts were ultimately included. 92.6% (25/27) IFAs included keywords of ER, indicating the presence of ethical considerations. However, no specific ER was required for CAM (n = 0). We categorized journals by Geographic origin, JCR section, Year of electronic JCR, Types of studies, % of OA Gold to explore the factors that could influence CAM journals to have certain ethical review policies. The results showed there was no statistical significance in certain ethical review policy in any classification of journals (p > 0.05). All RCT manuscripts included in the study generally met the requirements of the published journals for ethical review. CONCLUSIONS: All IFAs discussed ER, but the content was scattered, unfocused, and there were no specific ER requirements regarding CAM. Although the manuscripts basically met the requirements of the journal, it was not possible to get closer to the process of ER in the manuscript. To ensure full implementation of these policies in the future, CAM journals should require authors to provide more details, or to form a list of items necessary for CAM ethical review.
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Terapias Complementares , Políticas Editoriais , Publicações Periódicas como Assunto , Terapias Complementares/ética , Estudos Transversais , Humanos , Publicações Periódicas como Assunto/ética , Revisão Ética , Autoria , Editoração/éticaRESUMO
Podophyllotoxin (PPT) is a lignan derived from the roots and stems of the Podophyllum plant. However, its enterotoxicity restricts its clinical application. The underlying mechanisms by which PPT exerts its action remain largely elusive. This study aimed to evaluate the molecular mechanisms underlying PPT-induced enterotoxicity utilizing the concept of toxicological evidence chain. Changes in body weight, behavior, and histopathological and biochemical markers in rats were observed. Additionally, microbiome, metabolome, and transcriptome analyses were integrated to identify potential microorganisms, metabolic markers, and major pathways using a co-occurrence network. Our findings suggested that PPT induced pathological changes in rats, including weight loss, diarrhea, and inflammation accompanied by increased levels of IFN-γ, IL-5, IL-6, GRO/KC, and IL-12p70. The decrease in butyrate levels in the PPT group may be related to the enrichment of Firmicutes. The reduction of butyrate levels may impair the expression of PPARγ, subsequently promoting Escherichia-Shigella proliferation. Additionally, the suppression of PPARs pathway may result in the increased production of inflammatory factors, contributing to enterotoxicity. This study offers a novel understanding of the molecular mechanisms underlying PPT-induced enterotoxicity, making a significant contribution to developing strategies to mitigate PPT toxicity and prevent associated diseases.
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Podofilotoxina , Animais , Podofilotoxina/toxicidade , Ratos , Masculino , Microbioma Gastrointestinal/efeitos dos fármacos , Ratos Sprague-Dawley , Receptores Ativados por Proliferador de Peroxissomo/metabolismo , PPAR gama/metabolismo , Microbiota/efeitos dos fármacosRESUMO
Objectives: To evaluate the efficacy and safety of CHM in the prevention of COVID-19 infection and treatment for COVID-19 related symptoms. Design: Prospective open-label randomized controlled trial. Setting: Participants' home in Hong Kong. Participants: Participants who had household close contact with COVID-19-infected family members. Interventions: Close contacts were stratified into 4 groups (cohort A, B, C, D) based on symptoms and infection status and were randomized in 4:1 ratio to receive CHM granules (9g/sachet, two times daily) or blank control for 7 days with 2 weeks of follow-up. Main outcome measures: The primary outcome measure was the rate of positive nucleic acid tests. Secondary outcomes were the proportion of developed COVID-19 related symptoms and adverse events during the whole 3-week study period. Subgroup analysis was used to evaluate demographic factors associated with positive infection rates. Results: A total of 2163 contacts were enrolled and randomly assigned to the CHM group (1720 contacts) and blank control (443 contacts) group. During the 21 days, the rate of PCR-positive cases in cohort A was markedly lower in the CHM group (3.6%) compared to the control group (7.0%) (P=0.036). Overall, the rate of infection in the CHM group was significantly lower than that in the control group (10.69% vs. 6.03%; RR 0.56, 95% CI 0.39-0.82) after 7-day treatment. No serious adverse events were reported during the medication period. Conclusion: The preliminary findings indicate that CHM may be effective and safe in preventing COVID-19. Future double-blind, randomized controlled trials and long-term follow-up are needed to fully evaluate the efficacy of CHM in a larger contact population. Clinical trial registration: ClinicalTrials.gov, identifier NCT05269511.
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COVID-19 , Medicamentos de Ervas Chinesas , SARS-CoV-2 , Humanos , Masculino , Feminino , Hong Kong/epidemiologia , Pessoa de Meia-Idade , COVID-19/prevenção & controle , COVID-19/epidemiologia , Adulto , Medicamentos de Ervas Chinesas/uso terapêutico , Medicamentos de Ervas Chinesas/efeitos adversos , Medicamentos de Ervas Chinesas/administração & dosagem , Estudos Prospectivos , Tratamento Farmacológico da COVID-19 , Resultado do Tratamento , Características da Família , Idoso , Adulto Jovem , AdolescenteRESUMO
BACKGROUND: It is urgent to implement interventions to increase vaccination rates of influenza/pneumonia vaccines in older adults, yet the effectiveness of different intervention strategies has not been thoroughly evaluated. OBJECTIVE: We aimed to assess the effectiveness of intervention strategies for increasing the coverage of influenza/pneumonia vaccination in older adults. METHODS: PubMed, Web of Science, Cochrane Library, Embase, China Biology Medicine disc, China National Knowledge Infrastructure and Wanfang were searched from 1 January 2000 to 1 October 2022. RCTs that assessed any intervention strategies for increasing influenza/pneumonia vaccination coverage or willingness in older adults were included. A series of random-effects network meta-analysis was conducted by using frequentist frameworks. RESULTS: Twenty-two RCTs involving 385,182 older participants were eligible for further analysis. Eight types of intervention strategies were evaluated. Compared with routine notification, health education (odds ratio [OR], 1.85 [95%CI, 1.19 to 2.88]), centralised reminder (OR, 1.63 [95%CI, 1.07 to 2.47]), health education + onsite vaccination (OR, 2.89 [95%CI, 1.30 to 6.39]), and health education + centralised reminder + onsite vaccination (OR, 20.76 [95%CI, 7.33 to 58.74]) could effectively improve the vaccination rate. The evidence grade was low or very low due to the substantial heterogeneity among studies. CONCLUSIONS: Our findings suggest that health education + centralised reminder + onsite vaccination may potentially be an effective strategy regardless of cost, but the evidence level was low. More rigorous trials are needed to identify the association between strategies and vaccination rates among older adults and to integrate such evidence into clinical care to improve vaccination rates.
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Vacinas contra Influenza , Influenza Humana , Metanálise em Rede , Pneumonia , Cobertura Vacinal , Humanos , Vacinas contra Influenza/administração & dosagem , Idoso , Influenza Humana/prevenção & controle , Cobertura Vacinal/estatística & dados numéricos , Pneumonia/prevenção & controle , Pneumonia/epidemiologia , Educação em Saúde/métodos , Vacinação/estatística & dados numéricos , Sistemas de AlertaRESUMO
Perovskite light-emitting diodes (PeLEDs) have shown great potential in the display domain due to their wide color gamut, narrow emission, and low cost. In current PeLEDs manufacturing methods, thermal evaporation shows great competitiveness with its advantages of easy patterning, production line compatibility, and solvent-free processability. However, the development of thermally evaporated blue PeLEDs is limited by their low radiative recombination rate and high defect density. Herein, we report high-performance thermally evaporated blue PeLEDs by in situ introduction of ammonium cations. We confirm that phenethylammonium (PEA+) has lower adsorption energy, which significantly reduces the low-n phases in a quasi-2D perovskite film. The energy transfer rate is also promoted by the PEA+ addition. As a result, we fabricate blue PeLEDs with an external quantum efficiency of 1.56% by thermal evaporation. The strategy of arranging phase distribution could benefit the industrialization of full-color PeLEDs.
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Long non-coding RNA (LncRNA) SOX21-AS1 has been reported that it plays an important role in biological processes of several cancers. However, how it functions in cervical cancer (CC) still remain unclear. This investigation seeks to explore the impact of SOX21-AS1 on CC cell proliferation, invasion and migration and its association to the FZD3 and the Wnt/ß-catenin signaling pathway. SOX21-AS1 expression levels were detected using real-time quantitative PCR in 20 cases of cervical cancer together with its adjacent tissues and several cervical cancer cell lines. Transgenic technology and functional experiments were conducted to confirm the carcinogenic properties of SOX21-AS1, and western blot was utilized to analyze the regulatory network composed of SOX21-AS1, FZD3 and the Wnt/ß-catenin signaling pathway in CC. Through bioinformatics analysis, we found that the expression of SOX21-AS1 in CC was the highest among 16 kinds of tumor tissues. Moreover, clinical specimens confirmed that both CC tissues and cell lines possessed elevated SOX21-AS1 expressions (P < 0.01). CC cells which stably expressed upregulated SOX21-AS1 were noted to possesses higher rates of metastasis, invasion and proliferation, lower apoptotic rates and higher expression of FZD3,ß-catenin and c-myc (P < 0.01). Conversely, the use of small interfering RNA to inhibit the expression of SOX21-AS1 yielded the opposite results (P < 0.01). SOX21-AS1 functions as an oncogenic LncRNA which enhances CC cell metastasis, invasion and proliferation through FZD3 upregulation via Wnt/ß-catenin-signaling pathway activation. This LncRNA may represent an important biomarker for CC patients.
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Bi3TiNbO9, a layered ferroelectric photocatalyst, exhibits great potential for overall water splitting through efficient intralayer separation of photogenerated carriers motivated by a depolarization field along the in-plane a-axis. However, the poor interlayer transport of carriers along the out-of-plane c-axis, caused by the significant potential barrier between layers, leads to a high probability of carrier recombination and consequently results in low photocatalytic activity. Here, we have developed an efficient photocatalyst consisting of Bi3TiNbO9 nanosheets with a gradient tungsten (W) doping along the c-axis. This results in the generation of an additional electric field along the c-axis and simultaneously enhances the magnitude of depolarization field within the layers along the a-axis due to strengthened structural distortion. The combination of the built-in field along the c-axis and polarization along the a-axis can effectively facilitate the anisotropic migration of photogenerated electrons and holes to the basal {001} surface and lateral {110} surface of the nanosheets, respectively, enabling desirable spatial separation of carriers. Hence, the W-doped Bi3TiNbO9 ferroelectric photocatalyst with Rh/Cr2O3 cocatalyst achieves an efficient and durable overall water splitting feature, thereby providing an effective pathway for designing excellent layered ferroelectric photocatalysts.
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BACKGROUND: While substantial placebos have been used in herbal medicine (HM) clinical trials for rare diseases, the use and quality of reporting of HM-placebo remain unclear. We aim to describe the use of HM-placebo in clinical trials for rare diseases and determine the quality of reporting in these trials. METHODS: This is a cross-sectional study. We searched PubMed, Embase, Web of Science, SinoMed, China National Knowledge Infrastructure, WanFang database, China Science and Technology Journal Database, National Institute of Informatics Support Academic Information Services, ClinicalTrials.gov and Chinese Clinical Trials Registry from their inception date to 14 February 2023 to identify registered and published trials that use placebos as a comparator in rare diseases. We collected data on placebo use reporting and the efficacy and safety of placebo. Descriptive statistics, the Chi-square test, and Binary multivariable logistic regression analysis were used to determine the placebo characteristics of the HM trial and its effect on reporting. RESULTS: Among the 55 studies, we included that with a median administration time of placebo of 84 days (IQR 42-180) and a median placebo sample size of 30 (IQR 24-54). About half of the trials (27, 49.1%) did not provide their ethical approvals, and one trial had details of informed consent. None of the studies were fully reported and more than half of the items reported less than 50%. A total of 10 trials (18.2%) of placebo has active ingredients even though none of them performed pharmacological inert tests. Of the 29 studies with available data on adverse events, 5 (17.2%) trials did not show a better safety profile in the placebo group. Under the context that a relatively high-quality report is defined as a report with more than 9 items, there was a statistically significant difference between the two groups in the rate of relatively high-quality reports of the administration time (p = 0.047, OR 0.10, 95% CI 0.01 to 0.90), but the results are not representative. CONCLUSION: The overall situation of HM-placebo in the field of rare diseases was poor. In particular, the placebo is tied to the quality of trials, and poor placebo hinders the generation of high-quality evidence for herbal clinical trials in the field of rare diseases. We summarize the current methods of assessment involved in the use of placebos and propose various considerations for placebos in different contexts. Our study can greatly promote rare disease researchers to review the quality of their placebo and clinical trials. It is imperative to guarantee that meticulously conducted research generates clinical evidence of the highest caliber. We also expect that in the future, more rigorous relevant standards about the reporting and design of HM-placebo will be developed. High-quality clinical trials are the prerequisite for the wide clinical application of herbal medicines for rare diseases.
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Medicamentos de Ervas Chinesas , Humanos , China , Estudos Transversais , Medicamentos de Ervas Chinesas/uso terapêutico , Medicina Herbária , Doenças Raras/tratamento farmacológico , Ensaios Clínicos como AssuntoRESUMO
The difference in age structure and aging population level was an important factor that caused the difference in COVID-19's case fatality rate (CFR) in various regions. To eliminate the age effect on estimating the CFR of COVID-19, our study applied nonlinear logistic model and maximum likelihood method to fit the age-fatality curves of COVID-19 in different countries and regions. We further computed the standardized mortality ratio from the age-fatality curves of COVID-19 in the above regions and found that the risk of COVID-19 death in Wuhan was of a moderate level, while the non-Hubei region was even lower, compared with other regions. Regarding the disparity of CFRs among different regions in the country, we believed that there might be an unascertained phenomenon in high-endemic regions. Based on age-fatality rate curves, we estimated unascertained rates in cities with severe epidemics such as Wuhan and New York, and it was found that the total unascertained rates in Wuhan and New York were 81.6% and 81.2%, respectively. Meanwhile, we also found that the unascertained rates varied greatly with age.
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A systematic review and meta-analysis were conducted to evaluate the clinical effectiveness and safety of Shugan Jieyu capsules for treating insomnia by searching seven databases up to February 21, 2022. The study was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The quality of the studies was assessed using the risk of bias assessment tool. This article describes in detail how to retrieve and screen the literature. The detailed steps for conducting the meta-analysis are also included in the protocol. Fourteen studies were found to be eligible, including 1,283 insomnia patients (644 with and 639 without Shugan Jieyu capsules at baseline). The meta-analysis showed a better total clinical effectiveness (odds ratio [OR]: 5.71, 95% confidence interval [CI]: 3.56 to 9.15) and a lower Pittsburgh Sleep Quality Index (PSQI) score (mean difference [MD]: -2.95, 95% CI: -4.97 to -0.93) with combined Shugan Jieyu capsules and Western medicine compared to Western medicine alone. The secondary outcomes showed that the Shugan Jieyu capsule group had significantly reduced adverse reactions and improvements in sleep duration, night awakening, nightmares with excessive dreaming, daytime sleepiness, and low energy. Further multicenter randomized trials must be encouraged to provide more concrete evidence on whether Shugan Jieyu capsules are beneficial in routine clinical practice.
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Medicamentos de Ervas Chinesas , Distúrbios do Início e da Manutenção do Sono , Humanos , Cápsulas , Bases de Dados Factuais , Duração do Sono , Medicamentos de Ervas Chinesas/uso terapêuticoRESUMO
BACKGROUND: Propensity score analysis is increasingly used to control for confounding factors in observational studies. Unfortunately, unavoidable missing values make estimating propensity scores extremely challenging. We propose a new method for estimating propensity scores in data with missing values. MATERIALS AND METHODS: Both simulated and real-world datasets are used in our experiments. The simulated datasets were constructed under 2 scenarios, the presence (T = 1) and the absence (T = 0) of the true effect. The real-world dataset comes from LaLonde's employment training program. We construct missing data with varying degrees of missing rates under three missing mechanisms: MAR, MCAR, and MNAR. Then we compare MTNN with 2 other traditional methods in different scenarios. The experiments in each scenario were repeated 20,000 times. Our code is publicly available at https://github.com/ljwa2323/MTNN . RESULTS: Under the three missing mechanisms of MAR, MCAR and MNAR, the RMSE between the effect and the true effect estimated by our proposed method is the smallest in simulations and in real-world data. Furthermore, the standard deviation of the effect estimated by our method is the smallest. In situations where the missing rate is low, the estimation of our method is more accurate. CONCLUSIONS: MTNN can perform propensity score estimation and missing value filling at the same time through shared hidden layers and joint learning, which solves the dilemma of traditional methods and is very suitable for estimating true effects in samples with missing values. The method is expected to be broadly generalized and applied to real-world observational studies.
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Redes Neurais de Computação , Humanos , Pontuação de PropensãoRESUMO
Yellow light-emitting diodes (LEDs) are widely utilized in high-quality lighting, light communication, indicator lamps, etc. Owing to their outstanding material properties and device performance, the metal halide perovskites have demonstrated a significant potential for LED applications. However, the performance of the yellow perovskite LEDs (PeLEDs) is inferior to that of their green and red counterparts, with the maximum external quantum efficiency (EQE) limited to â¼3.1%. Further, a majority of the yellow PeLEDs are fabricated using the spin-coating methods. The current study reports the development of the yellow CsPbBr2I PeLEDs based on an all-vacuum deposition approach, which has been widely employed in the commercial organic LEDs (OLEDs). By controlling the co-evaporation rate of CsI and PbBr2, the growth kinetics of the perovskite layer are regulated to achieve a small grain size of â¼31.8 nm. Consequently, an improved radiative recombination rate (8.04 × 10-9 cm3/s) is obtained owing to the spatial confinement effect. The PeLEDs based on the optimal perovskite film demonstrate the yellow electroluminescence (574 nm) with a maximum EQE of â¼3.7% and luminance of â¼16,200 cd/m2, thus, representing one of the most efficient and bright yellow PeLEDs. Overall, this study provides a useful guideline for realizing the efficient PeLEDs based on the thermal evaporation strategy and highlights the potential of PeLED as an efficient and bright yellow light source.
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Objective: To investigate the efficacy of Integrative medicine (IM), compare with Western medicine (WM), in the treatment of rheumatoid arthritis (RA) in a cohort study. Methods: This is a cohort study with recruitment of RA patients from 10 hospitals in China. The primary outcome was change in disease activity score 28 (DAS28) during 4 follow-up visits. Generalized estimating equation (GEE) models that controlled for variables were used to investigate a time trend and assess group differences in the primary outcome and secondary outcomes after propensity score matching (PSM). Results: A total of 3195 patients with RA received IM (n = 1379, 43.2%) or WM (n = 1816, 56.8%). Following 1:1 propensity score matching, 1,331 eligible patients prescribed IM were compared to 1,331 matched patients prescribed WM. The GEE analysis with PSM showed that the IM was more beneficial to significantly decrease the levels of VAS, PGA and PhGA (VAS: odds ratio (OR), 0.76; 95% CI, 0.63-0.92; p = 0.004; PGA: OR, 0.76; 95% CI, 0.64-0.92; p = 0.007; and PhGA: OR, 0.77; 95% CI, 0.64, 0.93; p = 0.004), and reduce DAS28 (OR, 0.84; 95% CI, 0.73-0.98; p = 0.030) in the per-protocol population. Conclusion: This study suggests that compare to WM, IM has advantages in improving RA-related outcomes. However, the statistical significance might not reveal significant clinical difference. Further studies should be focused on specific treatment strategies and/or disease stages.
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The online preparation of fibers using molten modified blast furnace slag can not only achieve the high-value-added utilization of the slag but can also make use of the sensible heat of the slag. In this paper, blast furnace slag was modified using iron tailings, and was then used to prepare slag fiber online; the effects of the acidity coefficient on the properties of the molten modified blast furnace slag and modified blast furnace slag fiber were investigated. With an increase in the acidity coefficient from 1.2 to 1.6, the temperature range of the slag melt, with viscosity in the 1-3 Pa·s range, increased from 101.2 °C to 119.9 °C. The melting temperature increased from 1326.2 °C to 1388.7 °C, and the suitable fiber-forming temperature range increased from 70.7 °C to 82.9 °C. With the increasing acidity coefficient, the crystallization temperature of the molten modified slag decreased markedly. When the acidity coefficient was greater than 1.4, the slag system was still in a disordered glassy phase at 1100 °C. The hardening speed gradually reduced with the increasing acidity coefficient when the modified slag was cooled at the critical cooling rate, resulting in a gradual increase in fiber formability. The fibers prepared from the modified slag at different acidity coefficients had smooth surfaces, and were arranged in a crossed manner at the macroscopic level. Their color was white, and small quantities of slag balls were doped inside the fibers. With an increase in the acidity coefficient from 1.2 to 1.6, the average fiber diameter increased from 4.2 µm to 8.2 µm, and their slag ball content increased from 0.73% to 4.49%. Overall, the acidity coefficient of modified blast furnace slag should be less than 1.5 in actual production.
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BACKGROUND: Climate change caused by environmental pollution is the most important one of many environmental health hazards currently faced by human beings. In particular, the extreme temperature is an important risk factor for death from respiratory and circulatory diseases. This study aims to explore the meteorological-health effect and find out the vulnerable individuals of extreme temperature events in a less developed city in western China. METHOD: We collected the meteorological data and data of death caused by respiratory and circulatory diseases in Mianyang City from 2013 to 2019. The nonlinear distributed lag model and the generalized additive models were combined to study the influence of daily average temperature (DAT) on mortality from respiratory and circulatory diseases in different genders, ages. RESULTS: The exposure-response curves between DAT and mortality from respiratory and circulatory diseases presented a nonlinear characteristic of the "V" type. Cumulative Relative Risk of 30 days (CRR30) of deaths from respiratory diseases with 4.48 (2.98, 6.73) was higher than that from circulatory diseases with 2.77 (1.96, 3.92) at extremely low temperature, while there was no obvious difference at extremely high temperature. The health effects of low temperatures on the respiratory system of people of all ages and genders were persistent, while that of high temperatures were acute and short-term. The circulatory systems of people aged < 65 years were more susceptible to acute effects of cold temperatures, while the effects were delayed in females and people aged ≥65 years. CONCLUSION: Both low and high temperatures increased the risk of mortality from respiratory and circulatory diseases. Cold effects seemed to last longer than heat did.
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Doenças Cardiovasculares , Transtornos Respiratórios , China/epidemiologia , Cidades/epidemiologia , Temperatura Baixa , Feminino , Temperatura Alta , Humanos , Masculino , Mortalidade , Fatores de Risco , Temperatura , Fatores de TempoRESUMO
Phase junctions of photocatalysts can promote the separation of photogenerated charge carriers for efficient utilization of the carriers. Construction of phase junctions and establishing their structure-performance relationship are still required. Herein, polycrystalline TiO2 decahedral plates with different phases were synthesized by thermal treatment-induced topotactic transition of titanium oxalate crystals. The phase of TiO2 evolved from pure anatase to anatase-brookite, anatase-brookite-rutile, and then to anatase-rutile, while the morphology of the decahedral plates was well maintained. The biphase anatase-brookite was found to be most efficient in photocatalytic hydrogen generation. Specifically, the hydrogen generation rate of the biphase anatase-brookite TiO2 was nearly 2.4 times greater than that of the biphase anatase-rutile TiO2. The spatially resolved surface photovoltage measurements indicate the more efficient separation of photogenerated charge carriers and thus greater photocatalytic activity of the former. This work provides a strategy for developing efficient phase-junction photocatalysts.
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BACKGROUND: Corona virus disease 2019 (COVID-19) showed a significant difference in case fatality rate between different regions at the early stage of the epidemic. In addition to the well-known factors such as age structure, detection efficiency, and race, there was also a possibility that medical resource shortage caused the increase of the case fatality rate in some regions. METHODS: Medline, Cochrane Library, Embase, Web of Science, CBM, CNKI, and Wanfang of identified articles were searched through 29 June 2020. Cohort studies and case series with duration information on COVID-19 patients were included. Two independent reviewers extracted the data using a standardized data collection form and assessed the risk of bias. Data were synthesized through description and analysis methods including a meta-analysis. RESULTS: A total of 109 articles were retrieved. The time interval from onset to the first medical visit of COVID-19 patients in China was 3.38±1.55 days (corresponding intervals in Hubei province, non-Hubei provinces, Wuhan, Hubei provinces without Wuhan were 4.22±1.13, 3.10±1.57, 4.20±0.97, and 4.34±1.72 days, respectively). The time interval from onset to the hospitalization of COVID-19 patients in China was 8.35±6.83 days (same corresponding intervals were 12.94±7.43, 4.17±1.45, 14.86±7.12, and 5.36±1.19 days, respectively), and when it was outside China, this interval was 5.27±1.19 days. DISCUSSION: In the early stage of the COVID-19 epidemic, patients with COVID-19 did not receive timely treatment, resulting in a higher case fatality rate in Hubei province, partly due to the relatively insufficient and unequal medical resources. This research suggested that additional deaths caused by the out-of-control epidemic can be avoided if prevention and control work is carried out at the early stage of the epidemic. TRIAL REGISTRATION: CRD42020195606.
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COVID-19 , COVID-19/epidemiologia , China/epidemiologia , Estudos de Coortes , Hospitalização , Humanos , SARS-CoV-2RESUMO
With rapid advances of perovskite light-emitting diodes (PeLEDs), the large-scale fabrication of patterned PeLEDs towards display panels is of increasing importance. However, most state-of-the-art PeLEDs are fabricated by solution-processed techniques, which are difficult to simultaneously achieve high-resolution pixels and large-scale production. To this end, we construct efficient CsPbBr3 PeLEDs employing a vacuum deposition technique, which has been demonstrated as the most successful route for commercial organic LED displays. By carefully controlling the strength of the spatial confinement in CsPbBr3 film, its radiative recombination is greatly enhanced while the nonradiative recombination is suppressed. As a result, the external quantum efficiency (EQE) of thermally evaporated PeLED reaches 8.0%, a record for vacuum processed PeLEDs. Benefitting from the excellent uniformity and scalability of the thermal evaporation, we demonstrate PeLED with a functional area up to 40.2 cm2 and a peak EQE of 7.1%, representing one of the most efficient large-area PeLEDs. We further achieve high-resolution patterned perovskite film with 100 µm pixels using fine metal masks, laying the foundation for potential display applications. We believe the strategy of confinement strength regulation in thermally evaporated perovskites provides an effective way to process high-efficiency and large-area PeLEDs towards commercial display panels.
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Flat panel displays enjoy 100 billion-dollar markets with significant penetration in daily life, which require efficient, color-saturated blue, green, and red light-emitting diodes (LEDs). The recently emerged halide perovskites have demonstrated low-cost and outstanding performance for potential LED applications. However, the performance of blue perovskite LEDs (PeLEDs) lags far behind red and green cousins, particularly for color coordinates approaching (0.131, 0.046) that fulfill the Rec. 2020 specification for blue emitters. Here, a high-efficiency, lead-free perovskite, CsEuBr3 , is reported that exhibits bright blue exciton emission centered at 448 nm with a color coordinates of (0.15, 0.04), contributed from Eu-5dâEu-4f/Br-4p transition with an optical band gap of 2.85 eV. Further optical characterizations reveal its short excited-state lifetime of 151 ns, excellent exciton diffusion diffusivity of 0.0227 cm2 s-1 , and high quantum yield of ≈69%. Inspired by these findings, deep-blue PeLEDs based on all-vacuum processing methods, which have been demonstrated as the most successful approach for the organic LED industry, are constructed. The devices show a maximum external quantum efficiency of 6.5% with an operating half-lifetime of 50 mins at an initial brightness of 15.9 cd m-2 . It is anticipated that this work will inspire further research on lanthanide-based perovskites for next-generation LED applications.