679 research outputs found
New class of 3D topological insulator in double perovskite
We predict a new class of three-dimensional topological insulators (TIs) in
which the spin-orbit coupling (SOC) can more effectively generate a large band
gap at point. The band gap of conventional TI such as BiSe is
mainly limited by two factors, the strength of SOC and, from electronic
structure perspective, the band gap when SOC is absent. While the former is an
atomic property, we find that the latter can be minimized in a generic
rock-salt lattice model in which a stable crossing of bands {\it at} the Fermi
level along with band character inversion occurs for a range of parameters in
the absence of SOC. Thus, large-gap TI's or TI's comprised of lighter elements
can be expected. In fact, we find by performing first-principle calculations
that the model applies to a class of double perovskites ABiXO (A = Ca,
Sr, Ba; X = Br, I) and the band gap is predicted up to 0.55 eV. Besides, more
detailed calculations considering realistic surface structure indicate that the
Dirac cones are robust against the presence of dangling bond at the boundary
with a specific termination.Comment: submitted; title changed and new references added; see DOI for
published versio
Physiological indexes, psychological resilience, sensory functions, and sleep quality on the cognitive function of older adults with pre-frailty: a predictive study
Population ageing has increased the prevalence of
prefrailty comorbid with cognitive impairment among older adults. However, few
studies have explored the risk factors common to both prefrailty and cognitive
impairment. This study determined the predictive accuracy of demographic
characteristics, physiological indexes, psychological resilience, sensory
function, and sleep quality on the cognitive function of older adults with
prefrailty. In this cross-sectional study, the physiological
indexes, psychological resilience, sensory function, sleep quality, and cognitive
function of 167 community-dwelling older adults with prefrailty recruited through
purposive sampling were measured. SPSS software was used for data coding and
compilation. Data analysis involved the use of descriptive statistics, the
independent samples t test, the chi-square test, and logistic
regression. Overall, in cognitive function, there was no
difference in gender but were in age, were incapable of text messaging, had a
greater number of chronic diseases, were less able to perform activities of daily
living, had low psychological resilience, and had depressive tendencies. In
addition, Text messaging capability and depression status can all predict the
cognitive impairment state of prefrail older elderly. Physiological indexes, psychological resilience, sensory function, and sleep
quality can affect cognitive function in older adults with prefrailty. Meanwhile,
depressive tendencies and the inability to send text messages on a mobile device
constituted critical predictors of cognitive function in the participants
Archaeobotanical evidence of plant cultivation from the Sanbaopi site in south-western Taiwan during the Late Neolithic and Metal Age
Despite decades of lively debate about Taiwan’s role in the spread of early agriculture, crops and cultivation practices to the Indo-Pacific region, there is little archaeobotanical data from the island. Here we present the first directly dated and systematically analysed macrobotanical records from Taiwan obtained by flotation at the archaeological site Sanbaopi 5 (23°07′03′′N, 120°15′32′′E), representing the Dahu (1400 BCE–100 CE) and Niaosong (100–1400 CE) culture periods. The results suggest that Middle Dahu (900–100 BCE) communities in the study area practiced rainfed crop cultivation with mainly foxtail (Setaria italica) and broomcorn (Panicum miliaceum) millet and rice (Oryza sativa). Pulses (Vigna angularis, Glycine soja/max) were also part of the subsistence of local farmers and used as supplementary food and/or green manure. The archaeobotanical record together with archaeological site data for prehistoric China substantiates evidence that the Dahu culture originates in the Lower Yellow River region and migrated to Taiwan along the East China Sea coast. The emergence of the Dahu culture coincided with the spread of mixed millet-rice farming to the Korean Peninsula and Japan and was possibly related to enhanced economic and political expansion of the Shang and Western Zhou dynasties and the long-term weakening of summer monsoon precipitation. Pigeon pea (Cajanus cajan) and mung bean (V. radiata var. radiata) assemblages from the sixth century CE Niaosong period highlight the influx of goods, crops, knowledge and people from South and Southeast Asia via southern routes in the context of enhanced exchange across the South China Sea region
Association of Chinese Herbal Medicine use with the depression risk among the long-term breast cancer survivors: A longitudinal follow-up study
Background Breast cancer patients are at elevated risk of depression during treatment, thus provoking the chance of poor clinical outcomes. This retrospective cohort study aimed to investigate whether integrating Chinese herbal medicines citation(CHM) into conventional cancer therapy could decrease the risk of depression in the long-term breast cancer survivors. Methods A cohort of patients aged 20–70 years and with newly diagnosed breast cancer during 2000–2008 was identified from a nationwide claims database. In this study, we focused solely on survivors of breast cancer at least1 year after diagnosis. After one-to-one matching for age, sex, and baseline comorbidities, breast cancer patients who received (n = 1,450) and did not receive (n = 1,450) CHM treatment were enrolled. The incidence rate and hazard ratio citation(HR) for depression between the two groups was estimated at the end of 2012. A Cox proportional hazard model was constructed to examine the impact of the CHM use on the risk of depression. Results During the study period, the incidence rate of depression was significantly lower in the treated cohort than in the untreated cohort [8.57 compared with 11.01 per 1,000 person-years citation(PYs)], and the adjusted HR remained significant at 0.74 (95% CI 0.58–0.94) in a Cox proportional hazards regression model. The corresponding risk further decreasing to 43% among those using CHM for more than 1 year. Conclusion Finding from this investigation indicated that the lower risk of depression observed in breast cancer patients treated with CHM, suggesting that CHM treatment should be considered for disease management toward breast cancer. Yet, the optimal administered dose should be determined in further clinical trials
Neuroprotective Effect of Ginkgolide B on Bupivacaine-Induced Apoptosis in SH-SY5Y Cells
Local anesthetics are used routinely and effectively. However,
many are also known to activate neurotoxic pathways. We tested the neuroprotective
efficacy of ginkgolide B (GB), an active component of Ginkgo biloba, against
ROS-mediated neurotoxicity caused by the local anesthetic bupivacaine.
SH-SY5Y cells were treated with different concentrations of bupivacaine
alone or following preincubation with GB. Pretreatment with GB increased
SH-SY5Y cell viability and attenuated intracellular ROS accumulation, apoptosis,
mitochondrial dysfunction, and ER stress. GB suppressed bupivacaine-induced
mitochondrial depolarization and mitochondria complex I and III inhibition and increased
cleaved caspase-3 and Htra2 expression, which was strongly indicative of activation of
mitochondria-dependent apoptosis with concomitantly enhanced expressions of Grp78,
caspase-12 mRNA, protein, and ER stress. GB also improved ultrastructural changes
indicative of mitochondrial and ER damage induced by bupivacaine. These results implicate
bupivacaine-induced ROS-dependent mitochondria, ER dysfunction, and apoptosis,
which can be attenuated by GB through its antioxidant property
Spatiotemporal Genotype Replacement of H5N8 Avian Influenza Viruses Contributed to H5N1 Emergence in 2021/2022 Panzootic
Since 2020, clade 2.3.4.4b highly pathogenic avian influenza H5N8 and H5N1 viruses have swept through continents, posing serious threats to the world. Through comprehensive analyses of epidemiological, genetic, and bird migration data, we found that the dominant genotype replacement of the H5N8 viruses in 2020 contributed to the H5N1 outbreak in the 2021/2022 wave. The 2020 outbreak of the H5N8 G1 genotype instead of the G0 genotype produced reassortment opportunities and led to the emergence of a new H5N1 virus with G1's HA and MP genes. Despite extensive reassortments in the 2021/2022 wave, the H5N1 virus retained the HA and MP genes, causing a significant outbreak in Europe and North America. Furtherly, through the wild bird migration flyways investigation, we found that the temporal-spatial coincidence between the outbreak of the H5N8 G1 virus and the bird autumn migration may have expanded the H5 viral spread, which may be one of the main drivers of the emergence of the 2020-2022 H5 panzootic.IMPORTANCESince 2020, highly pathogenic avian influenza (HPAI) H5 subtype variants of clade 2.3.4.4b have spread across continents, posing unprecedented threats globally. However, the factors promoting the genesis and spread of H5 HPAI viruses remain unclear. Here, we found that the spatiotemporal genotype replacement of H5N8 HPAI viruses contributed to the emergence of the H5N1 variant that caused the 2021/2022 panzootic, and the viral evolution in poultry of Egypt and surrounding area and autumn bird migration from the Russia-Kazakhstan region to Europe are important drivers of the emergence of the 2020-2022 H5 panzootic. These findings provide important targets for early warning and could help control the current and future HPAI epidemics.</p
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