44 research outputs found

    Origin and evolutionary history of Populus (Salicaceae): Further insights based on time divergence and biogeographic analysis

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    IntroductionPopulus (Salicaceae) species harbour rich biodiversity and are widely distributed throughout the Northern Hemisphere. However, the origin and biogeography of Populus remain poorly understood.MethodsWe infer the divergence times and the historical biogeography of the genus Populus through phylogenetic analysis of 34 chloroplast fragments based on a large sample.Results and DiscussionEurasia is the likely location of the early divergences of Salicaceae after the Cretaceous-Paleogene (K-Pg) mass extinction, followed by recurrent spread to the remainder of the Old World and the New World beginning in the Eocene; the extant Populus species began to diversity during the early Oligocene (approximately 27.24 Ma), climate changes during the Oligocene may have facilitated the diversification of modern poplar species; three separate lineages of Populus from Eurasia colonized North America in the Cenozoic via the Bering Land Bridges (BLB); We hypothesize that the present day disjunction in Populus can be explained by two scenarios: (i) Populus likely originated in Eurasia and subsequently colonized other regions, including North America; and (ii) the fact that the ancestor of the genus Populus that was once widely distributed in the Northern Hemisphere and eventually wiped out due to the higher extinction rates in North America, similar to the African Rand flora. We hypothesize that disparities in extinction across the evolutionary history of Populus in different regions shape the modern biogeography of Populus. Further studies with dense sampling and more evidence are required to test these hypotheses. Our research underscores the significance of combining phylogenetic analyses with biogeographic interpretations to enhance our knowledge of the origin, divergence, and distribution of biodiversity in temperate plant floras

    Comparative efficacy of face-to-face and internet-based cognitive behavior therapy for generalized anxiety disorder: A meta-analysis of randomized controlled trial

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    ObjectiveThe study aimed to ascertain the comparative efficacy of these two forms on reducing anxiety scores of scales in patients with a generalized anxiety disorder (GAD) by examining the available evidence for face-to-face cognitive behavior therapy (CBT) and internet-based cognitive behavior therapy (ICBT). Moreover, this study attempted to determine whether ICBT can obtain similar benefits as CBT for GAD patients during coronavirus disease 2019 (COVID-19) due to the quarantine policy and the requirement of social distance.MethodsThis meta-analysis was registered with the International Prospective Register of Systematic Reviews (PROSPERO) according to the guidelines in the Preferred Reporting Items for Systematic Reviews and Meta-analyses statement (registration number CRD42021241938). Therefore, a meta-analysis of randomized controlled trials (RCTs) examining CBT or ICBT was conducted in this study to treat GAD patients diagnosed with DMS-IV. The researchers searched PubMed, MEDLINE, Embase, PsycINFO, and the Cochrane Database of Systematic Reviews for relevant studies published from 2000 to July 5, 2022. Evidence from RCTs was synthesized by Review Manager 5.4 as mean difference (MD) for change in scores of scales through a random-effects meta-analysis.ResultsA total of 26 trials representing 1,687 participants were pooled. The results demonstrated that ICBT and CBT were very close in the effect size of treating GAD (MD = −2.35 vs. MD = −2.79). Moreover, they still exhibited a similar response (MD = −3.45 vs. MD = −2.91) after studies with active control were removed.ConclusionRegarding the treatment of GAD, ICBT can achieve a similar therapeutic effect as CBT and could be CBT's candidate substitute, especially in the COVID-19 pandemic era, since the internet plays a crucial role in handling social space constraints.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=241938, identifier CRD42021241938

    Layer-by-Layer Epitaxy of Multilayer MoS2 Wafers

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    Two-dimensional (2D) semiconductor of MoS2 has great potential for advanced electronics technologies beyond silicon1-9. So far, high-quality monolayer MoS2 wafers10-12 are already available and various demonstrations from individual transistors to integrated circuits have also been shown13-15. In addition to the monolayer, multilayers have narrower band gaps but improved carrier mobilities and current capacities over the monolayer5,16-18. However, achieving high-quality multilayer MoS2 wafers remains a challenge. Here we report the growth of high quality multilayer MoS2 4-inch wafers via the layer-by-layer epitaxy process. The epitaxy leads to well-defined stacking orders between adjacent epitaxial layers and offers a delicate control of layer numbers up to 6. Systematic evaluations on the atomic structures and electronic properties were carried out for achieved wafers with different layer numbers. Significant improvements on device performances were found in thicker-layer field effect transistors (FETs), as expected. For example, the average field-effect mobility ({\mu}FE) at room temperature (RT) can increase from ~80 cm2V-1s-1 for monolayer to ~110/145 cm2V-1s-1 for bilayer/trilayer devices. The highest RT {\mu}FE=234.7 cm2V-1s-1 and a record-high on-current densities of 1.704 mA{\mu}m-1 at Vds=2 V were also achieved in trilayer MoS2 FETs with a high on/off ratio exceeding 107. Our work hence moves a step closer to practical applications of 2D MoS2 in electronics.Comment: 13 pages,4 Figure

    Room-temperature correlated states in twisted bilayer MoS2_2

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    Moir\'e superlattices have emerged as an exciting condensed-matter quantum simulator for exploring the exotic physics of strong electronic correlations. Notable progress has been witnessed, but such correlated states are achievable usually at low temperatures. Here, we report the transport evidences of room-temperature correlated electronic states and layer-hybridized SU(4) Hubbard model simulator in AB-stacked MoS2_2 homo-bilayer moir\'e superlattices. Correlated insulating states at moir\'e band filling factors v = 1, 2, 3 are unambiguously established in twisted bilayer MoS2_2. Remarkably, the correlated electronic states can persist up to a record-high critical temperature of over 285 K. The realization of room-temperature correlated states in twisted bilayer MoS2_2 can be understood as the cooperation effects of the stacking-specific atomic reconstruction and the resonantly enhanced interlayer hybridization, which largely amplify the moir\'e superlattice effects on electronic correlations. Furthermore, extreme large non-linear Hall responses up to room-temperature are uncovered near correlated insulating states, demonstrating the quantum geometry of moir\'e flat conduction band.Comment: 13 pages, 3 figure

    Seasonal human coronavirus NL63 epidemics in children in Guilin, China, reveal the emergence of a new subgenotype of HCoV-NL63

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    IntroductionSeasonal human coronavirus NL63 (HCoV-NL63) is a frequently encountered virus linked to mild upper respiratory infections. However, its potential to cause more severe or widespread disease remains an area of concern. This study aimed to investigate a rare localized epidemic of HCoV-NL63-induced respiratory infections among pediatric patients in Guilin, China, and to understand the viral subtype distribution and genetic characteristics.MethodsIn this study, 83 pediatric patients hospitalized with acute respiratory infections and positive for HCoV-NL63 were enrolled. Molecular analysis was conducted to identify the viral subgenotypes and to assess genetic variations in the receptor-binding domain of the spiking protein.ResultsAmong the 83 HCoV-NL63-positive children, three subgenotypes were identified: C4, C3, and B. Notably, 21 cases exhibited a previously unreported subtype, C4. Analysis of the C4 subtype revealed a unique amino acid mutation (I507L) in the receptor-binding domain of the spiking protein, which was also observed in the previously reported C3 genotype. This mutation may suggest potential increases in viral transmissibility and pathogenicity.DiscussionThe findings of this study highlight the rapid mutation dynamics of HCoV-NL63 and its potential for increased virulence and epidemic transmission. The presence of a unique mutation in the C4 subtype, shared with the C3 genotype, raises concerns about the virus’s evolving nature and its potential public health implications. This research contributes valuable insights into the understanding of HCoV-NL63’s epidemiology and pathogenesis, which is crucial for effective disease prevention and control strategies. Future studies are needed to further investigate the biological significance of the observed mutation and its potential impact on the virus’s transmissibility and pathogenicity

    A promising Na3V2(PO4)(3) cathode for use in the construction of high energy batteries

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    High-energy batteries need significant cathodes which can simultaneously provide large specific capacities and high discharge plateaus. NASICON-structured Na3V2(PO4)3 (NVP) has been utilised as a promising cathode to meet this requirement and be used in the construction of high energy batteries. For a hybrid-ion battery by employing metallic lithium as an anode, NVP exhibits an initial specific capacity of 170 mA h g 1 in the voltage range of 1.6–4.8 V with a long discharge plateau around 3.7 V. Three Na(2) sites for NVP are found capable to be utilised through the application of a wide voltage window but only two of them are able to undergo ions exchange to produce a NaLi2V2(PO4)3 phase. However, a hybrid-ion migration mechanism is suggested to exist to describe the whole ion transport in which the effects of a Na-ion ‘‘barrier’’ results in a lowered ion diffusion rate and observed specific capacity. 1. Introduction Lithium-ion battery (LIB) technology is critically needed for many applications in a plethora of industries and is an important energystorage solution which can be potentially applied, for instance into electric vehicles (EVs).1,2 However, LIB has continued to be primarily relegated by the electronics market mainly due to its cost and material issues3 and the lack of high-performance cathode materials have become a technological bottleneck for the commercial development of advanced LIB.4 Particularly for the entrance of LIB into high energy fields, such as EVs and renewable energy storage in smart grids, the demand for highcapacity and voltage cathodes is starting to become a key focus of research. In the search for new positive-electrode materials for LIB, recent research has focused upon nano-structured lithium transitional-metal phosphates that exhibit desirable properties such as high energy storage capacities combined with electrochemical stability.5,6 Olivine LiFePO4,7 as one member of this class, has risen to prominence so far due to other characteristics involving low cost, low environmental impact and safety, which ar

    Sub-Hourly Variability of Stable Isotopes in Precipitation in the Marginal Zone of East Asian Monsoon

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    Isotope data at mid-latitude locations are commonly available on annual, monthly, and daily timescales; however, they are rarely available for the variations occurring on the sub-hourly scale within individual precipitation events. To fill this gap, sub-hourly (every 10 min) sequential samples were collected for nine precipitation events, and the δ18O values of the individual events were analyzed from June to October 2019 in Lanzhou, Northwest China. The Sequential Meteoric Water Line (SMWL) correlation between δ2H and δ18O is δ2H = 7.33 δ18O + 9.78 (R2 = 0.97, N = 170). All events had a similar decreasing variability pattern in the initial period (before the vertical gray dotted line), while during the later period (after the vertical gray dotted line), negative δ18O values dominated, exhibiting a different pattern. Variations in the δ18O values were about 1–5‰ during most intra-events. We found that δ18O values mainly exhibit three patterns in the intra-event, namely a “V”-shaped pattern, an “L”-shaped pattern, and a decreasing pattern. Positive δ18O values are controlled by re-evaporation in the beginning period. Relative humidity has no effect on the δ18O values of precipitation events, mainly because dry and warm conditions are conducive to the evaporation of rainwater in the study region. The changes in the isotopic characteristics of precipitation are closely linked to the regional climate. The continuous analysis of precipitation samples revealed that the rapid change of δ18O values is related to different moisture sources and transport paths. A new air mass with enriched heavy isotope intrusion can change the isotopic composition in the intra-event

    Syntheses, Characterization, and Application of Tridentate Phenoxyimino-Phenoxy Aluminum Complexes for the Coupling of Terminal Epoxide with CO<sub>2</sub>: From Binary System to Single Component Catalyst

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    A series of binuclear aluminum complexes 1–3 supported by tridentate phenoxyimino-phenoxy ligands was synthesized and used as catalysts for the coupling reaction of terminal epoxide with carbon dioxide. The aluminum complex 1, which is catalytically inactive toward the coupling of epoxide with CO2 by itself, shows moderate activity in the presence of excess nucleophiles or organic bases at high temperature. In sharp contrast to complex 1, bifunctional complexes 2 and 3, which incorporate tertiary amine groups as the built-in nucleophile, are able to efficiently transform terminal epoxide with CO2 to corresponding cyclic carbonates as a sole product by themselves at 100 °C. The number of amine groups on the ligand skeleton and the reaction temperature exert a great influence on the catalytic activity. The bifunctional complexes 2 and 3 are also active at low carbon dioxide pressure such as 2 atm or atmospheric CO2 pressure. Kinetic studies of the coupling reactions of chloropropylene oxide/CO2 and styrene oxide/CO2 using bifunctional catalysts under atmospheric pressure of CO2 demonstrate that the coupling reaction has a first-order dependence on the concentration of the epoxide

    Decomposition Analysis of Depressive Symptom Differences Among Older Adults With Hypertension Between Urban and Rural Areas: Cross-Sectional Study

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    Abstract BackgroundHypertension is the most prevalent chronic disease among China’s older population, which comprises a growing proportion of the overall demographic. Older individuals with chronic diseases have a higher risk of developing depressive symptoms than their healthy counterparts, as evidenced in China’s older population, where patients with hypertension exhibit varying rates of depression depending on residing in urban or rural areas. ObjectiveThis study aimed to investigate factors influencing and contributing to the disparities in depressive symptoms among older urban and rural patients with hypertension in China. MethodsWe used a cross-sectional study design and derived data from the 8th Chinese Longitudinal Health Longevity Survey of 2018. The Fairlie model was applied to analyze the factors contributing to disparities in depressive symptoms between urban and rural older populations with hypertension. ResultsThe sample size for this study was 5210, and 12.8% (n=669) of participants exhibited depressive symptoms. The proportions of depressive symptoms in rural and urban areas were 14.1% (n=468) and 10.7% (n=201), respectively. In rural areas, years of education (1-6 years: odds ratio [OR] 0.68, 95% CI 1.10-1.21; ≥7 years: OR 0.47, 95% CI 0.24-0.94), alcohol consumption (yes: OR 0.52, 95% CI 0.29-0.93), exercise (yes: OR 0.78, 95% CI 0.56-1.08), and sleep duration (6.0-7.9 hours: OR 0.29, 95% CI 0.17-0.52; 8.0-9.9 hours: OR 0.24, 95% CI 0.13-0.43; ≥10.0 hours: OR 0.22, 95% CI 0.11-0.41) were protective factors against depressive symptoms in older adults with hypertension, while gender (female: OR 1.94, 95% CI 1.33-2.81), self-reported income status (poor: OR 3.07, 95% CI 2.16-4.37), and activities of daily living (ADL) dysfunction (mild: OR 1.69, 95% CI 1.11-2.58; severe: OR 3.03, 95% CI 1.46-6.32) were risk factors. In urban areas, age (90-99 years: OR 0.37, 95% CI 0.16-0.81; ≥100 years: OR 0.19, 95% CI 0.06-0.66), exercise (yes: OR 0.33, 95% CI 0.22-0.51), and sleep duration (6.0-7.9 hours: OR 0.27, 95% CI 0.10-0.71; 8.0-9.9 hours: OR 0.16, 95% CI 0.06-0.44; ≥10.0 hours: OR 0.18, 95% CI 0.06-0.57) were protective factors, while years of education (1-6 years: OR 1.91, 95% CI 1.05-3.49), self-reported income status (poor: OR 2.94, 95% CI 1.43-6.08), and ADL dysfunction (mild: OR 2.38, 95% CI 1.39-4.06; severe: OR 3.26, 95% CI 1.21-8.76) were risk factors. The Fairlie model revealed that 91.61% of differences in depressive symptoms could be explained by covariates, including years of education (contribution 63.1%), self-reported income status (contribution 13.2%), exercise (contribution 45.7%), sleep duration (contribution 20.8%), ADL dysfunction (contribution −9.6%), and comorbidities (contribution −22.9%). ConclusionsOlder patients with hypertension in rural areas had more depressive symptoms than their counterparts residing in urban areas, which could be explained by years of education, self-reported income status, exercise, sleep duration, ADL dysfunction, and comorbidities. Factors influencing depressive symptoms had similarities regarding exercise, sleep duration, self-reported income status, and ADL dysfunction as well as differences regarding age, gender, years of education, and alcohol consumption

    Gold recovery from E-waste using freestanding nanopapers of cellulose and ionic covalent organic frameworks

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    The ever-increasing production of electronic devices generates a huge amount of electronic waste (E-waste). Therefore, there is an urgent need for advanced recycling technology for E-waste that provides both economic and environmental benefits. Herein, we describe the preparation of flexible, freestanding CF-COF nanopapers consisting of cellulose fibers (CFs) and guanidinium-based ionic covalent organic framework (COF) that can be used for recovering gold from E-waste leaching solutions via a membrane separation technique. Due to the synergetic effects of physical adsorption, ion exchange and chemical reduction, the COF has an extremely high capture capacity (up to 1,794 mg of Au per gram of COF), is highly selective and has fast kinetics for adsorbing trace amounts of [AuCl4]â\u88\u92 in aqueous solution. The high COF loadings (â\u88Œ50 wt%) and hierarchical porosity of the CF-COF nanopapers resulted in excellent performance when capturing gold species from the E-waste leaching solution. This study provides new possibilities for developing sustainable membrane materials, and highly efficient and cost-effective techniques for the recovery of precious metals from E-waste
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