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Abstract The paleoenvironment of Jixian carbonate rocks in the Mesoproterozoic Ordos Basin is studied by carbon and oxygen isotope analyses, diagenetic environment analysis, and the restoration of paleosalinity and paleotemperature. The results indicate that the carbonate rocks of the Jixian System have always been in a near-surface environment and have not been deeply buried. The ranges of variation in δ13CPDB and δ18OPDB are relatively narrow, ranging from − 5.75 to 1.41‰ and − 8.88 to − 4.01‰, respectively, which is consistent with the stable tidal flat sedimentary environment during the Mesoproterozoic in the study area. The paleosalinity (Z) values range from 111.7 to 127.1, and the paleotemperature (T) values range from 32.7 to 57.33 °C, indicating a relatively warm paleoclimatic environment during the Mesoproterozoic era in the study area. The analysis shows that in a warm paleoclimatic environment, although carbon and oxygen isotopes, Z, and T have certain fluctuations, their ranges are relatively small, reflecting to some extent the stable tectonic environment of the study area during the Mesoproterozoic era. Comprehensive research shows that the Ordos Basin had a warm climate and a stable tectonic environment in the Mesoproterozoic, which may be a good response to the North China Block's position near the equator and continuous thermal subsidence in the Mesoproterozoic.

Increasing exploration interest in oil and gas hosted by early Cambrian strata has focused research efforts on early Cambrian sandstones. The origin of phosphorus and the paleoenvironment of phosphorus-bearing sandstones from the Xinji Formation are discussed in this paper. X-ray diffraction, optical microscopy, grain size analysis, total organic carbon, and the concentrations of major, trace, and rare earth elements (REEs) are analyzed in this work. The sandstones are mostly sublitharenite with calcareous cement. The content of the sandstone samples is quartz (39.8%--73.9%), with illite (7.9%--27.6%) and calcite (4.5%--29%). The mineral particles of sandstone samples are mainly well sorted with a fine particle size, suggesting strong paleohydrodynamic force. The value of Si[O.sub.2] is 37.69%--78.19%, followed by [Al.sub.2][O.sub.3] (6.11%--13.67%). Compared with upper continental crust, the boron in the sandstone samples is relatively enriched, whereas Sc, Sr, and Ba are relatively depleted. The [SIGMA]REE content is 124.46-323.99 ppm. Phosphorus is of biogenic origin and enriched by upwelling current. The source of the Xinji Formation sandstone samples was mainly a mixture of sedimentary rock, granite, and alkali basalt, with the provenance of terrestrial clastic materials. The sandstone was deposited under oxic conditions and a warm and humid paleoclimate with saline to brackish features on a passive continental margin. Phosphorus occurring in sandstones is sensitive to paleoclimate and can be used as an indicator to judge paleoclimate, as it is more enriched in warm and humid weather. Key words: geochemistry, paleoenvironment, phosphorus-bearing sandstones, Xinji Formation, Ordos Basin. L'interet croissant pour l'exploration petroliere et gaziere dans des strates d'age cambrien precoce a eu pour consequence d'axer des efforts de recherche sur des gres de cet age. L'origine du phosphore et le paleomilieu de gres contenant du phosphore de la Formation de Xinji sont examines. La diffraction X, la microscopie optique, l'analyse granulometrique, ainsi que l'analyse du carbone organique total et des concentrations d'elements majeurs et en traces et des terres rares ont ete effectuees. Les gres sont pour la plupart des sublitharenites a ciment calcareux. Les teneurs des echantillons de gres en quartz sont de 39,8-73,9 %, avec de l'illite (7,9-27,6 %) et de la calcite (4,5-29 %). Les grains de mineraux sont principalement bien classes et de granulometrie fine, ce qui indiquerait de grandes forces paleohydrodynamiques. Les teneurs en Si[O.sub.2] sont de 37,69-78,19 %, suivies de l'[Al.sub.2][O.sub.3] (6,11-13,67 %). Par rapport a la croute continentale superieure, le bore est relativement enrichi dans les echantillons de gres, alors que le Sc, le Sr et le Ba sont appauvris. Les concentrations en terres rares totales ([SIGMA]REE) sont de 124,46 ppm--323,99 ppm. Le phosphore est d'origine biogenique et enrichi par des courants de remontee. La source des gres etudies de la Formation de Xinji etait principalement constituee d'un melange de roche sedimentaire, de granite et de basalte alcalin, la provenance des materiaux clastiques etant terrestre. Les gres se sont deposes dans des conditions oxydantes et chaudes, dans un paleoclimat humide et dans un milieu de marge continentale passive caracterise par des eaux salines a saumatres. Le phosphore dans les gres est sensible au paleoclimat et peut etre utilise comme indicateur de ce dernier, son enrichissement refletant des conditions meteorologiques chaudes et humides. [Traduit par la Redaction] Mots-cles: geochimie, paleomilieu, gres contenant du phosphore, Formation de Xinji, bassin d'Ordos., Introduction The Ordos Basin is the largest petroliferous basin in China (Zhang 2000; Hou et al. 2003; Xi et al. 2006; Liu et al. 2009; Shi et al. 2009). Current [...]

The Fengcheng Formation in the Mahu sag of the Junggar Basin was primarily composed of detritus, pyroclastic material, carbonates, and evaporites. In order to establish the diagenesis pathways of the Fengcheng Formation, some methods of polarized light microscope, SEM, CL, EPMA, LR, and fluid inclusion analysis were applied to discuss the diagenesis process. The results showed the following: (a) The formation of an alkaline lake was the result of the influence of a high concentration of sodium-rich sources, and it led to the preservation of alkaline minerals in the stratum. (b) After the sediments were buried, three mineral assemblages were formed in the Fengcheng Formation, which are carbonate mineral assemblages (i.e., calcite + ferreous dolomite), reedmergnerite and carbonate mineral assemblages (i.e., reedmergnerite + calcite + ferreous dolomite), and reedmergnerite and alkaline mineral assemblages (i.e., reedmergnerite + shortite + trona), respectively. (c) According to the homogenization temperature of reedmergnerite primary fluid inclusions, the alkaline diagenesis of Fengcheng Formation was divided into an early stage (≤100 °C) and a middle stage (>100 °C), respectively. The earlier stage is marked by the formation of ferrous saddle dolomite, quartz dissolution, and the agglutination of laumontite. These processes occurred under normal burial conditions. The latter is marked by the reedmergnerite's appearance, which is correlated with the deep hydrothermal activity controlled by faults. (d) Based on sedimentary and diagenetic factors, including climate, provenance, diagenetic surroundings, and the action of subsurface fluid, the alkaline deposition-diagenesis model for shale series in four stages of the Fengcheng Formation was established. [ABSTRACT FROM AUTHOR]

Wide‐bandgap (WBG) perovskite solar cells (PSCs) have garnered significant attention for their potential applications in tandem solar cells. However, their large open‐circuit voltage (VOC) deficit and serious photo‐induced halide segregation remain the main challenges that impede their applications. Herein, a post‐treatment strategy without thermal annealing is presented to form a 2D top layer of 2‐thiopheneethylammonium lead halide (n = 1) on WBG perovskites. This thermal annealing‐free post‐treatment method can more effectively passivate the defects of WBG methylamine (MA)‐free formamidinium/cesium lead iodide/bromide perovskite films and suppress photo‐induced perovskite phase segregation, as compared with the thermal annealing method that yields multi‐2D phases. The resulting opaque and semi‐transparent 1.66 eV‐bandgap perovskite solar cells deliver maximum power conversion efficiencies of 21.47% (a small VOC deficit of 0.43 V) and 19.11%, respectively, both of which are among the highest reports for inverted MA‐free WBG PSCs. Consequently, four‐terminal all‐perovskite tandem cells realize a remarkable efficiency of 26.64%, showing great promise for their applications in efficient multi‐junction tandem solar cells. [ABSTRACT FROM AUTHOR]

With the rapid development of the internet economy, many manufacturers have opened online direct sales channels and built multi-channel distribution systems. Meanwhile, both consumers and companies are paying more attention to extended warranty services. Considering a dual-channel supply chain with a manufacturer and a retailer, we assume the manufacturer provides an extended warranty in the online direct channel and investigates the decision making of the supply chain players. We develop three game models to study this problem, and they are the basic model without extended warranty (Model B), the decentralized decision model with the manufacturer's extended warranty (Model M), and the centralized decision model with the manufacturer's extended warranty (Model C). The Stackelberg game method is used to solve the established model, the influence of relevant parameters on the solution result is analyzed, and different models are compared. Compared with Model B, we find that the whole supply chain always be better, but the retailer would be worse in Model M. Compared with Model M, we find that the entire supply chain always performs better in Model C. Finally, we do some sensitivity analysis. [ABSTRACT FROM AUTHOR]

Quasi‐two‐dimensional (quasi‐2D) perovskite light‐emitting diodes (PeLEDs) are considered as one of the most potential candidates in electroluminescence territory owing to their unique quantum confinement effect and excellent thermal stability of the light. Nevertheless, heterogeneous energy domain distribution leads to severe non‐radiative recombination in the process of energy transfer, which enormously hinders the performance and application of PeLEDs. Herein, an ambipolar amino acid, 5‐aminovaleric acid (5AVA), is demonstrated to be able to coordinate lead and halides simultaneously with its carboxyl and amidogen groups. The coordinated ambipolar molecule not only reconstitutes energy domains of perovskites but also minimizes the interfacial defects of PeLEDs. Accordingly, the presence of 5AVA in perovskite precursors leads to dramatic suppression of the n = 1 and n = 2 phases and accelerates energy transfer from wide bandgap domains to narrow bandgap ones. As a result, maximum external quantum efficiency (EQE) of 19.3% (18.20% ± 1.10%) is achieved in quasi‐2D green PeLEDs with current efficiency of 61.7 cd A−1. [ABSTRACT FROM AUTHOR]

External encapsulation technique as a straightforward craft process has been adopted to prevent the infiltration of moisture and oxygen, thereby improving environmental stabilities of lead halide perovskite solar cells (PSCs). However, irreversible light‐induced degradation originating from various vacancies and ion diffusion or migration inside the device cannot be efficiently solved by external encapsulation. Herein, an internal encapsulation strategy by introducing NbCl5 at the buried tin oxide/perovskite interface and spin‐casting n‐butylammonium bromide on top of perovskite is developed to comprehensively passivate the vacancies and hence block the channels for ion diffusion or migration. The internal encapsulation strategy results in better homogeneous electron transport layer and effective vacancy passivation at the buried interface and simultaneously generates a more homogeneous, better crystallized perovskite in the vertical direction with significantly reduced residual PbI2. Furthermore, fewer oxygen vacancies and formation of ultrathin Nb2O5 lead to a better interfacial energy level alignment for electron transfer. As a result, power conversion efficiency (PCE) of the resulting PSCs is as high as 24.01%. More importantly, the device demonstrates an excellent stability, retaining 88% of its initial PCE at its maximum power point tracking measurement (under 100 mW cm–2 white light illumination at ≈55 °C temperature, in N2 atmosphere) after 1000 h. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) has been widely investigated in optoelectronic devices because of its non-toxicity, high optical absorption coefficient, intrinsic p-type conductivity, and high hole mobility. However, misaligned energy levels remain an obstacle to obtaining efficient optoelectronic devices due to the extremely high conduction band minimum of Cu2O. Here, a band-aligned wide bandgap Ga2O3 buffer layer is introduced and a graded heterojunction ZnO/Ga2O3/Cu2O is realized. The oxygen-vacancy concentration and therefore the Fermi level, optical transmittance, and bandgap of the Ga2O3 films can be tuned by controlling the oxygen environment during pulsed laser deposition. The performance of the optoelectronic devices is improved by incorporating an optimized Ga2O3 buffer layer deposited at 1 Pa oxygen pressure with a deposition temperature of 100 °C. Photodetectors with a response range from the near-ultraviolet to the visible-light region, good linearity, fast response, and excellent long-term stability are demonstrated. In the meantime, an enhancement of the external quantum efficiency of 66% was reached by inserting the Ga2O3 buffer layer. Heterojunctions with gradient energy bands are confirmed to be effective in accelerating charge transport and suppressing carrier recombination through Kelvin probe force microscopy (KPFM) studies. Our work provides a new approach for developing self-powered ultraviolet and visible-light photodetectors with low-cost and high stability. [ABSTRACT FROM AUTHOR]

P‐type semiconductor cuprous oxide (Cu2O) offers promising optoelectronic applications such as solar cells and photodetectors owing to its considerable absorption coefficients and high carrier mobility. However, polycrystalline Cu2O films with low carrier mobility resulting from excessive grain boundaries and structure disorder fail to meet the demands for these optoelectronic applications. Here a stress‐assisted thermal oxidation method to fabricate p‐type <110>‐textured quasi‐single crystalline Cu2O (c‐Cu2O) wafers with centimeter‐scale grains is developed. It is found that strain energy induced by thermal contact stress plays a critical role in crystal growth. The resultant <110>‐textured quasi‐single c‐Cu2O wafers exhibit excellent crystallinity with rocking curve having a low full width at half maximum of 0.022°, a low defect density of 2 × 1011 cm−3, a high mobility exceeding 100 cm2 V−1 s−1, and a long minority lifetime of 98.5 µs. Such quasi‐single c‐Cu2O wafers lead to efficient solar cells with an open‐circuit voltage of 0.95 V and highly responsive photodetectors with superior cycling stability. These results indicate not only the advancement of fabricating high‐quality Cu2O wafers upon controllable methodology but also the promising optoelectronic applications using p‐type metal oxide semiconductors. [ABSTRACT FROM AUTHOR]

Trap‐induced nonradiative recombination and decomposition are the major limiting factors that hinder the development of mixed‐halide wide‐bandgap perovskite solar cells. Specifically, the incorporation of formamidinium (FA+) and bromide in wide‐bandgap (WBG) perovskite materials leads to shallow‐energy‐level traps and inferior light stability. Herein, the electron‐withdrawing molecule 2,3,5,6 tetrafluoro‐7,7,8,8‐tetracyanoquinodimethane (F4‐TCNQ) is used as an effective passivator and stabilizer, which has molecular interaction with the FA+ cation for reducing trap densities and enhancing the stability of WBG perovskite solar cells. It is found that the extended π aromatic system in F4‐TCNQ can enhance the binding energy and stabilize the FA+ cation in perovskite films. Furthermore, the 1.67 eV bandgap inverted perovskite solar cells with a small amount of F4‐TCNQ have shallower defect levels, reduced trap density, and decreased nonradiative recombination, therefore giving a remarkably improved power conversion efficiency (PCE) of 20.0%. Most importantly, the unencapsulated devices with F4‐TCNQ additive have greatly enhanced stability, maintaining 88% of their peak PCEs under continuous illumination after 840 h, whereas the control devices only retain 48% of their PCEs after 500 h. [ABSTRACT FROM AUTHOR]

Metal halide perovskite nanocrystals (NCs) serve as a kind of ideal semiconductor for luminescence and display applications. However, the optoelectronic performance and stability of perovskite NCs are mainly subjected to current ligand strategies since these ligands exhibit a highly dynamic binding state, which complicates NC purification and storage. Herein, a method named diffusion‐induced extraction is developed for crystallization (DEC) at room temperature, in which silicone oil serves as a medium to separate the solvent from perovskite precursors and diethyl ether promotes the nucleation, leading to highly emissive perovskite NCs. The formation mechanism of NCs using this approach is elucidated, and their optoelectronic properties are fully characterized. The resultant NCs ink exhibits a high photoluminescence quantum yield (PLQY) over 90% with a narrow full width at half maximum of 17 nm. The DEC method strengthens the interaction between ligand and NCs via the hydrophobic silicone oil. Therefore, the NCs maintain almost 95% of their initial PLQYs after aging more than seven months in air. The findings will be of great significance for the continued advancement of high PLQY perovskite NCs through a better understanding of formation dynamics. The DEC strategy presents a major step forward for advancing the field of perovskite semiconductor nanomaterials. [ABSTRACT FROM AUTHOR]

Tracing and isolation of close contacts is used to control outbreaks of coronavirus disease 2019 (COVID‐19) in China. However, risk factors associated with the occurrence of COVID‐19 among close contacts have not been well described. A total of 106 household contacts were included in this study, of whom 19 developed into COVID‐19 cases, and the secondary attack rate was 17.9%. Multivariable analysis showed that increasing risk of occurrence of COVID‐19 among household contacts was associated with female index patients (adjusted hazard ratio [aHR] = 3.84, 95% CI = 1.07–13.78), critical disease index patients (aHR = 7.58, 95% CI = 1.66–34.66), effective contact duration with index patients > 2 days (aHR = 4.21, 95% CI = 1.29–13.73), and effective contact duration > 11 days (aHR = 17.88, 95% CI = 3.26–98.01). The sex and disease severity of index patients with COVID‐19 and longer effective contact duration with patients with confirmed COVID‐19 could help epidemiologists to identify potential COVID‐19 cases among household contacts at an early stage. [ABSTRACT FROM AUTHOR]

Antireflection (AR) film is a widely used technology to enhance the performance of photovoltaic devices that require transparent electrodes in the photovoltaic industry. At present, several AR films including monolayer MgF2 or multilayered composite films, textured polydimethylsiloxane (PDMS) and porous SiO2 have been successfully applied due to their excellent properties. Nevertheless, all of the above-mentioned AR films have some minor drawbacks to overcome, for instance, the cost or thermal durability. Herein, we report a cost-effective and low-temperature method to fabricate a mesoporous aluminum oxide (meso-Al2O3) layer as the AR coating with high thermal durability, which will meet the fabrication condition of various photovoltaic devices. Briefly, the process begins at magnetron sputtering a compact Al2O3 film, which shows no AR effect, followed by a hot water treatment at 80 °C to turn the compact film into a mesoporous film with graded-index and AR effect. The application of meso-Al2O3 AR film enhances the maximum transmittance of our laboratory-used fluorine-doped tin oxide (FTO) from 84% to 89%, which is in good agreement with our theoretical simulation named graded-index approximation. Taking perovskite solar cells (PSCs) as an example, planar PSCs with meso-Al2O3 AR film deliver excellent photon conversion efficiency of 21.5%, which is higher than that of cells without meso-Al2O3 AR film (20.9%). [ABSTRACT FROM AUTHOR]

The article focuses on the stratigraphic analysis of the Ordovician period where the level of the greenhouse gases was at it's highest level.

In this manuscript, Ni ions-doped NaYF:Yb/Er nanoparticles have been synthesized via a modified hydrothermal method. The upconversion luminescence intensities of the green (G) and red (R) emission of NaYF:Yb/Er co-doped with 20 mol% Ni ions are the strongest which increase 32.84 and 20.99 times than that without doping Ni, respectively. In addition, the R/G ratio decreases with the concentration of Ni increasing from 0 to 40 mol%. The underlying reason for luminescence enhanced and the R/G ratio decreased by Ni doping is explored by a series of controlled experiments, and the mechanism based on the crystal field asymmetry, different substitution by Ni, the energy transition of Er is studied in detail. The study indicates that the misshapen crystal field plays an important role in enhancement fluorescence emission, and several factors affect the R/G ratio including the crystal field, the substitution site and the energy transition. Our result may play a certain function for study and design of high-performance upconversion materials. [ABSTRACT FROM AUTHOR]

For middle/short-range terrestrial high-speed free-space optical (FSO) communication systems employing ON–OFF keying (OOK) and PIN photodiode receivers, the noise distribution is symbol-dependent, and the symmetry of the underlying communication channel cannot be assumed. Therefore, this letter employs the asymmetric density evolution technique and an optimization scheme combining four different search algorithms to optimize low-density parity-check (LDPC) codes for these FSO systems. Compared with the conventional LDPC codes that are designed assuming symbols-independent symmetric channels the optimized codes are much closer to the Shannon limit for OOK modulated binary non-symmetric channels. [ABSTRACT FROM PUBLISHER]

Keywords: Isolation; quarantine; SARS-CoV-2; Beta variant; Alpha variant; COVID-19; transmission; international travel EN Isolation quarantine SARS-CoV-2 Beta variant Alpha variant COVID-19 transmission international travel 1 2 2 01/05/22 20211201 NES 211201 Quarantine of international travelers at arrival, often in specialized quarantine centers or hotels, is a measure frequently used by many countries to reduce the risk of importation.[1-2, 3] Evidence of the risk for transmission by contaminated environment or fomites via infected travellers from such quarantine facilities is lacking. Isolation, quarantine, SARS-CoV-2, Beta variant, Alpha variant, COVID-19, transmission, international travel Environmental surfaces from their quarantine rooms were sampled and tested for SARS-CoV-2, using the same methods as reported in a previous study.4 In total, 22 environmental samples collected from 11 sampling sites of each quarantine room were taken. [Extracted from the article]

We evaluated the genetic and environmental contributions to metabolic cardiovascular risk factors and their mutual associations. Eight metabolic factors (body mass index, waist circumference, waist-to-hip ratio, systolic blood pressure, diastolic blood pressure, total serum cholesterol, serum triglycerides, and serum uric acid) were measured in 508 twin pairs aged 8–17 years from the Qingdao Twin Registry, China. Linear structural equation models were used to estimate the heritability of these traits, as well as the genetic and environmental correlations between them. Among boys, body mass index and uric acid showed consistently high heritability (0.49–0.81), whereas other traits showed moderate to high common environmental variance (0.37–0.73) in children (8–12 years) and adolescents (13–17 years) except total cholesterol. For girls, moderate to high heritability (0.39–0.75) were obtained for six metabolic traits in children, while only two traits showed high heritability and others mostly medium to large common environmental variance in adolescents. Genetic correlations between the traits were strong in both boys and girls in children (rg = 0.64–0.99 between body mass index and diastolic blood pressure; rg = 0.71–1.00 between body mass index and waist circumference), but decreased for adolescent girls (rg = 0.51 between body mass index and waist-to-hip ratio; rg = 0.55 between body mass index and uric acid; rg = 0.61 between body mass index and systolic blood pressure). The effect of genetic factors on most metabolic traits decreased from childhood to adolescence. Both common genetic and specific environmental factors influence the mutual associations among most of the metabolic traits. [ABSTRACT FROM PUBLISHER]

Mixed tin–lead (Sn–Pb) perovskites often face a daunting challenge: rapid and uncontrollable crystallization, leading to a plethora of defects and significant stress. This issue is particularly exacerbated during the blade‐coating preparation of scalable Sn–Pb perovskite films. In this study, a facile strategy involving the addition of ammonium citrate (AC) to narrow‐bandgap mixed Sn–Pb perovskite precursors is introduced. AC, armed with its arsenal of multiple carboxyl and amino groups, acts as a virtuoso conductor, orchestrating controlled crystal growth by harmonizing with Pb2+ and Sn2+ ions. This addition significantly boosts the crystallinity of the perovskite films, alleviates interface stress, inhibits Sn2+ oxidation, and mitigates interfacial defects. Consequently, The blade‐coated AC‐incorporated mixed Sn–Pb perovskite solar cells achieve a high photovoltaic conversion efficiency of nearly 21%. Furthermore, extending this strategy to two‐terminal all‐perovskite tandem solar cells yielded a remarkable maximum efficiency of 27.20%. This work presents an effective strategy for producing efficient blade‐coated mixed Sn–Pb perovskite solar cells, heralding a pathway toward scalable fabrication of all‐perovskite tandem solar cells. [ABSTRACT FROM AUTHOR]

Effective coupling between upconversion nanoparticles (UCNPs) and localized surface plasmon resonance (LSPR) nanostructures have been successfully used to improve the upconversion luminescence (UCL) of lanthanide ions. Here, to explore a more effective coupling method between Cu 1.8 S and UCNPs, Cu 1.8 S@NaYF 4 : X%Yb3+@NaYF 4 : Yb3+, Er3+ nanoparticles were synthesized. In comparison to NaYF 4 @NaYF 4 : Yb3+, Er3+ nanoparticles, the UCL intensity of the green and red emissions of Cu 1.8 S@NaYF 4 : 30%Yb3+@NaYF 4 : Yb3+, Er3+ nanoparticles were conspicuously increased by ~28-fold and ~101-fold, respectively. The significant enhancement of UCL in Cu 1.8 S@NaYF 4 : 30%Yb3+@NaYF 4 : Yb3+, Er3+ nanoparticles comes from the synergistic contribution of two aspects: LSPR light scattering of the Cu 1.8 S core and the increased near-infrared absorption from the appropriate amount of Yb3+ ions in the intermediate layer. The present work is important for possible applications of such core-shell nanoparticles to photocatalysis, bioluminescent labeling, and perovskite solar cells. [ABSTRACT FROM AUTHOR]

Background and Objectives: Fruit, vegetable, seafood, and dairy intake may reduce the risk of type 2 diabetes, but this relationship is unclear. We aimed to examine the associations between fruit, vegetable, seafood, and dairy intake and type 2 diabetes prevalence in a Chinese population.Methods and Study Design: A total of 4,343 individuals aged 35-74 years participated in a population-based cross-sectional study in Qingdao, China. The frequency and quantity of fruit, vegetable, seafood, and dairy intake were determined using a standard food frequency questionnaire. Diabetes was classified according to the WHO/IDF 2006 criteria. Logistic regression analysis was employed to estimate odds ratio (OR) for type 2 diabetes in relation to fruit, vegetable, seafood, and dairy intake in a multivariable model.Results: The multivariate-adjusted ORs (95% confidence interval) for the presence of type 2 diabetes were 0.68 (0.46-0.98), 0.50 (0.37-0.68), and 0.91 (0.66-1.25), respectively, for the highest versus the lowest groups regarding total fruit and vegetable, fruit or vegetable intake in women. The ORs for type 2 diabetes prevalence regarding the quantity of fruit and vegetable, fruit, and yogurt intake were 0.88 (0.78-0.99), 0.71 (0.61-0.82), and 0.56 (0.32-0.98) in women, but not in men. Seafood consumption was inversely associated with diabetes risk in men, but not in women; the corresponding figures were 0.58 (0.35-0.96) and 0.92 (0.63-1.36), respectively.Conclusions: Fruit, vegetable, and yogurt intake in women and seafood intake in men were inversely associated with type 2 diabetes prevalence in this Chinese population. These findings require confirmation in a prospective study. [ABSTRACT FROM AUTHOR]

Factors associated with negative conversion of SARS-CoV-2 RNA in hospitalized patients have not yet been systematically determined. We conducted a retrospective cohort study of COVID-19 patients in Qingdao, China. Both univariate and multivariate analysis were performed to identify independent factors for time to viral RNA negative conversion. Data on patients with re-detectable viral RNA after showing negative on RT-PCR test (intermittent negative status) were also analyzed. A total of 59 patients confirmed with COVID-19 were included in this study, with a median duration of 1 (interquartile range, IQR: 0–2) day from symptom onset to hospital admission. Median communicable period (from first day of positive nucleic acid test to first day of consecutive negative results) was 14 (IQR: 10–18) days, and 7 (IQR: 6–10) days for 10 patients with intermittent negative results. Age older than 45 years (hazard ratio, HR: 0.378; 95% confidence interval, CI: 0.205–0.698) and chest tightness (HR: 0.290; 95%CI: 0.091–0.919) were factors independently affecting negative conversion of SARS-CoV-2 RNA. Headache (odds ratio: 7.553; 95%CI: 1.011–28.253) was significantly associated with intermittent negative status, with a predicted probability of 60%. Older age and chest tightness were independently associated with delayed clearance of SARS-CoV-2 RNA in hospitalized patients. These predictors would provide a new perspective on early identification of patients with prolonged viral shedding and facilitate optimal isolation protocols and treatment strategies. Unlabelled Image • Older age were independently associated with delayed clearance of SARS-CoV-2 RNA. • Chest tightness were independently associated with delayed clearance of SARS-CoV-2 RNA. • Intermittent negative status was predicted a probability of 60% if occurring headache. [ABSTRACT FROM AUTHOR]