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Potassium and cerium co-doped Bi4Ti2.86W0.14O12 ceramics with a formula of (K0.5Ce0.5)xBi4−xTi2.86W0.14O12 (abbreviated as KC100x-BITW, x = 0, 0.02, 0.04, 0.06, 0.08, 0.1) were prepared by a conventional solid-state reaction method. The effect of (K0.5Ce0.5) complex doping amount on the structure, dielectric, and piezoelectric properties of the KC100x-BITW ceramics was investigated. X-ray diffraction results indicated that the KC100x-BITW ceramics are Aurivillius-type phase with the bismuth layer structure. (K0.5Ce0.5) complex addition first increases and then decreases the grain size which can be observed by scanning electron microscopy. With the increase of (K0.5Ce0.5) complex doping amount, the Curie temperature (TC) was slightly decreased from 632 to 608 oC. The dielectric and piezoelectric properties were optimized in KC100x-BITW ceramics with x = 0.08 as follows: d33 = 24 pC/N, kp = 8.2%, Qm = 6766, εr = 135 (@100 kHz), tanδ = 0.28% (@100 kHz), Tc = 611 oC, and resistivity ρ = 2.9 × 106 Ω cm at 500 oC, indicating that the KC100x-BITW ceramics are suitable for high-temperature piezoelectric sensing applications.
We report the first experiments on divergent shock-driven Richtmyer–Meshkov instability (RMI) at well-controlled single-mode interfaces. These experiments are performed in a novel divergent shock tube designed by shock dynamics theory. Generally, the perturbation growth can be divided into three successive stages: linear growth, quick reduction in growth rate and instability freeze-out. It is observed that the growth rate at each stage is far lower than its counterpart in planar or convergent geometry due to geometric divergence. We also found that nonlinearity is much weaker than that in planar or convergent RMI, and has a negligible influence on the overall amplitude growth even at late stages when it has become strong. This weak nonlinear effect is because the growth of the third harmonic counteracts its feedback to the fundamental mode. As a consequence, the linear theory of Bell (report no. LA-1321) accounting for geometric divergence and Rayleigh–Taylor (RT) stabilization caused by flow deceleration can reasonably predict the present results from early to late stages. The instability freeze-out at late times is ascribed to the negative growth induced by geometric divergence and RT stabilization, and is also well reproduced by the linear theory.
Oxygen concentration influences oocyte quality and subsequent embryo development, but it remains unclear whether oxygen concentrations affect the developmental competence and transcriptomic profile of yak oocytes. In this study, we investigated the effects of different oxygen concentrations (5% versus 20%) on the developmental competence, reactive oxygen species (ROS) levels, glutathione (GSH) content, and transcriptomic profile of yak oocytes. The results showed that a low oxygen concentration significantly increased the maturation rate of yak oocytes (81.2 ± 2.2% vs 75.9 ± 1.3%) and the blastocyst quality of yak in vitro fertilized embryos. Analysis of ROS and GSH showed that a low oxygen concentration reduced ROS levels and increased the content of GSH (75.05 ± 7.1 ng/oocyte vs 50.63 ± 5.6 ng/oocyte). Furthermore, transcriptomic analysis identified 120 differentially expressed genes (DEGs) between the two groups of oocytes. Gene enrichment analysis of the DEGs indicated multiple cellular processes, including oxidative phosphorylation, transcription regulation, mitochondrial regulation, oestrogen signalling pathway, HIF-1 signalling pathway, TNF signalling pathway, were involved in the response to oxygen concentration alterations. Taken together, these results indicated that a low oxygen concentration improved the developmental competence of yak oocytes.
Parabronema skrjabini is one of the most harmful nematodes to camels and is responsible for economic losses in animal husbandry industry. There is an urgent need for in-depth studies of potential vectors of the nematode due to its scant regarding information. As previous studies indicated that flies may be the vectors of P. skrjabini, we captured flies in the main camel-producing areas of Inner Mongolia. After autopsy of the specimens of two species of horn flies, we observed the morphology of the suspected nematode larvae found in them. Internal transcribed spacer ribosomal-DNA gene sequences were considered the best candidate to confirm the species of the larvae found. Our results showed that the homology compared with P. skrjabini was 99.5% in GenBank. Subsequently, we preliminarily identified two species of horn flies through morphological observation and then sequenced the mitochondrial-DNA-gene cytochrome oxidase subunit I obtained from two species of horn flies, with 100 and 99.2% similarity to sequences deposited in GenBank, respectively. Thus, we identified Haematobia titillans and Haematobia irritans and provided evidence for their potential role as vectors of parabronemosis. Our study provides reference for future research on the life history of the nematode and the vectors of parabronemosis.
The novel coronavirus disease 2019 (COVID-19) pandemic has spread to over 213 countries and territories. We sought to describe the clinical features of fatalities in patients with severe COVID-19.
We conducted an Internet-based retrospective cohort study through retrieving the clinical information of 100 COVID-19 deaths from nonduplicating incidental reports in Chinese provincial and other governmental websites between January 23 and March 10, 2020.
Approximately 6 of 10 COVID-19 deaths were males (64.0%). The average age was 70.7 ± 13.5 y, and 84% of patients were elderly (over age 60 y). The mean duration from admission to diagnosis was 2.2 ± 3.8 d (median: 1 d). The mean duration from diagnosis to death was 9.9 ± 7.0 d (median: 9 d). Approximately 3 of 4 cases (76.0%) were complicated by 1 or more chronic diseases, including hypertension (41.0%), diabetes (29.0%) and coronary heart disease (27.0%), respiratory disorders (23.0%), and cerebrovascular disease (12.0%). Fever (46.0%), cough (33.0%), and shortness of breath (9.0%) were the most common first symptoms. Multiple organ failure (67.9%), circulatory failure (20.2%), and respiratory failure (11.9%) are the top 3 direct causes of death.
COVID-19 deaths are mainly elderly and patients with chronic diseases especially cardiovascular disorders and diabetes. Multiple organ failure is the most common direct cause of death.
TiAl alloys are potential structural high-temperature structural materials at a service temperature of ~900 °C, while poor ductility at room temperature and high creep rate at the elevated temperature limits the applications. To improve the room-temperature and high-temperature mechanical properties of Ti–44Al–5Nb–3Cr–1.5Zr, Mo and B were introduced into this system and Ti–44Al–5Nb–3Cr–1.5Zr–xMo–yB alloys were proposed. And then, we, respectively, studied the microstructures and mechanical properties of Ti–44Al–5Nb–3Cr–1.5Zr–xMo–0B and Ti–44Al–5Nb–3Cr–1.5Zr–1Mo–yB to elucidate the role for the addition of Mo and B. It is found that Mo can increase the fraction of B2 phase in the alloys and the microstructures of the alloys are greatly refined by the addition of B. The compression test results indicate that Mo has a positive influence on the high-temperature compressive properties of TiAl-based alloys, whereas B addition can improve their room-temperature compressive properties of Ti–44Al–5Nb–3Cr–1.5Zr–1Mo–yB alloys; the morphology of borides in each sample should be the structural origin for these phenomena.
Accumulating studies have found structural and functional abnormalities of the striatum in bipolar disorder (BD) and major depressive disorder (MDD). However, changes in intrinsic brain functional connectivity dynamics of striato-cortical circuitry have not been investigated in BD and MDD. This study aimed to investigate the shared and specific patterns of dynamic functional connectivity (dFC) variability of striato-cortical circuitry in BD and MDD.
Brain resting-state functional magnetic resonance imaging data were acquired from 128 patients with unmedicated BD II (current episode depressed), 140 patients with unmedicated MDD, and 132 healthy controls (HCs). Six pairs of striatum seed regions were selected: the ventral striatum inferior (VSi) and the ventral striatum superior (VSs), the dorsal-caudal putamen (DCP), the dorsal-rostral putamen (DRP), and the dorsal caudate and the ventral-rostral putamen (VRP). The sliding-window analysis was used to evaluate dFC for each seed.
Both BD II and MDD exhibited increased dFC variability between the left DRP and the left supplementary motor area, and between the right VRP and the right inferior parietal lobule. The BD II had specific increased dFC variability between the right DCP and the left precentral gyrus compared with MDD and HCs. The MDD had increased dFC variability between the left VSi and the left medial prefrontal cortex compared with BD II and HCs.
The patients with BD and MDD shared common dFC alteration in the dorsal striatal-sensorimotor and ventral striatal-cognitive circuitries. The patients with MDD had specific dFC alteration in the ventral striatal-affective circuitry.
To investigate homocysteine (Hcy) and folate levels, prevalence of hyperhomocysteinaemia (HHcy) and folate deficiency, which are affected by lifestyles in urban, agricultural and stock-raising populations.
This is a cross-sectional study.
Urban, agricultural and stock-raising regions in Emin, China.
Totally 1926 subjects – 885 (45·9 %) from urban, 861 (44·7 %) from agricultural and 180 (9·4 %) from stock-raising regions – were obtained using multistage stratified random sampling. Inclusion criteria encompassed inhabitants aged ≥15 years who resided at the current address for ≥6 months and agreed to participate in the study. Surveys on health behaviour questionnaires and physical examinations were conducted and blood samples collected.
The folate level of subjects from the stock-raising region was the lowest, followed by those from the agricultural region, and the highest in those from the urban region (3·48 v. 6·50 v. 7·12 ng/ml, P < 0·001), whereas mean Hcy showed no significant difference across regions. The OR for HHcy in stock-raising regions was 1·90 (95 % CI 1·11, 3·27) compared with the urban region after adjusting for all possible covariates. The OR for folate deficiency in stock-raising and agriculture regions was 11·51 (95 % CI 7·09, 18·67) and 1·91 (95 % CI 1·30, 2·82), respectively, compared with the urban region after adjusting for all possible covariates.
HHcy and folate deficiency are highly prevalent in stock-raisers, which is of important reference for HHcy control in Xinjiang, with a possibility of extension to others with approximate lifestyles.
The oxidation behavior of the selective laser melting (SLM)–fabricated Inconel 718 was investigated through isothermal oxidation testing at 650 °C for 500 h and compared with that of the as-cast and as-forged specimens at the same testing conditions. The effect of microstructure and surface roughness on the oxidation behavior of the SLM-fabricated, as-cast, and as-forged Inconel 718 specimens was examined. The result shows that Inconel 718 fabricated by SLM with the unique layer structure exhibited a better resistance to the 500 h oxidation at 650 °C compared with as-cast and as-forged 718 with coarse dendritic structure and uniform equiaxed grain microstructure, respectively. The influence of the surface roughness on the long-time oxidation resistance of SLM specimens is not pronounced compared with that of as-cast and as-forged specimens. The tiny dendrites instead of grain boundaries are a major influencing factor for the oxidation process of SLM specimens. The surface roughness has more evident influence on the oxidation resistance of as-forged specimens than that of the as-cast ones subjected to the 500 h oxidation at 650 °C.
Outbreaks of norovirus-associated gastroenteritis have been reported in schools in recent decades in China. For early warning and response to infectious disease outbreaks, the Shanghai Infectious Diseases Bud Event Surveillance System (IDBESS) was established in 2016. Bud event is a term used for the early sign of a potential infectious disease outbreak in public settings when the first few cases appear. This study aimed to describe the epidemiological characteristics of Norovirus-associated gastroenteritis bud events from June 2016 to December 2017 and to understand factors influencing the severity of events. Data were extracted from the IDBESS, supplemented by field investigations and school absence surveillance. In total, 189 bud events of Norovirus-associated gastroenteritis were reported in schools and kindergartens, affecting 3827 individuals and 52.38% happened in primary schools. The attack rate of Norovirus-associated gastroenteritis was 3.82% on average in students in the affected schools. In each event, case numbers varied between 5 and 148, with a median of 16. The duration of bud events lasted for 2 days on average. School absence happened in 47.93% (1797/3749) of affected students and the average duration of absence was 3.07 days. It was found that a longer delay before reporting was associated with a longer-lasting duration of bud event (OR = 2.25, 95% CI: 1.65, 3.07). In conclusion, ascribed to the sensitive threshold for alerting and the timely field investigation, the surveillance of bud events of Norovirus-associated gastroenteritis is effective in the control of Norovirus infection among preschool children and students in Shanghai.
Cruciferous vegetables contain high levels of glucosinolates (GSL) and isothiocyanates (ITC). ITC are known to induce glutathione S-transferases (GST) and thus exert their anticarcinogenic effects. This study explored the combined effects of cruciferous vegetable, GSL and ITC intake and GST polymorphisms on breast cancer risk. A total of 737 breast cancer cases and 756 controls were recruited into this case–control study. OR and 95 % CI were assessed by multivariable logistic regression. Higher cruciferous vegetable, GSL and ITC intakes were inversely associated with breast cancer risk, with adjusted OR of 0·48 (95 % CI 0·35, 0·65), 0·54 (95 % CI 0·40, 0·74) and 0·62 (95 % CI 0·45, 0·84), respectively. Compared with women carrying the GSTP1 rs1695 wild AA genotype and high cruciferous vegetable, GSL or ITC intake, carriers of the AA genotype with low cruciferous vegetable, GSL and ITC intake had greater risk of breast cancer, with adjusted OR of 1·43 (95 % CI 1·01, 1·87), 1·34 (95 % CI 1·02, 1·75) and 1·37 (95 % CI 1·05, 1·80), respectively. Persons with the GSTM1-null genotype and lower intake of cruciferous vegetables, GSL and ITC had higher risk of breast cancer than those with the GSTM1-present genotype and higher intake, with OR of 1·42 (95 % CI 1·04, 1·95), 1·43 (95 % CI 1·05, 1·96) and 1·45 (95 % CI 1·06, 1·98), respectively. Among women possessing the GSTT1-present genotype, low intake of cruciferous vegetables, GSL or ITC was associated with higher risk of breast cancer. But these interactions were non-significant. This study indicated that there were no significant interactions between cruciferous vegetable, GSL or ITC intake and GST polymorphisms on breast cancer risk.
Post-cardiac surgery patients exhibit a higher incidence of postoperative delirium (PD) compared to non-cardiac surgery patients. Patients with various cardiac diseases suffer from preoperative sleep disorder (SPD) induced by anxiety, depression, breathing disorder, or other factors.
To examine the effect of sleep disorder on delirium in post-cardiac surgery patients.
We prospectively selected 186 patients undergoing selective cardiac valve surgery. Preoperative sleep quality and cognitive function of all eligible participants were assessed through the Pittsburgh Sleep Quality Index (PSQI) and the Montreal Cognitive Assessment, respectively. The Confusion Assessment Method for Intensive Care Unit was used to assess PD from the first to seventh day postoperatively. Patients were divided into two groups according to the PD diagnosis: (1) No PD group and (2) the PD group.
Of 186 eligible patients, 29 (15.6%) were diagnosed with PD. A univariate analysis showed that gender (p = 0.040), age (p = 0.009), SPD (p = 0.008), intraoperative infusion volume (p = 0.034), postoperative intubation time (p = 0.001), and intensive care unit stay time (p = 0.009) were associated with PD. A multivariate logistic regression analysis demonstrated that age (odds ratio (OR): 1.106; p = 0.001) and SPD (OR: 3.223; p = 0.047) were independently associated with PD. A receiver operating characteristic curve demonstrated that preoperative PSQI was predictive of PD (area under curve: 0.706; 95% confidence interval: 0.595–0.816). A binomial logistic regression analysis showed that there was a significant association between preoperative 6 and 21 PSQI scores and PD incidence (p = 0.009).
Preoperative SPD was significantly associated with PD and a main predictor of PD.
The study of the petrogenesis of some magmatic rocks with special geochemical attributes provides effective information for us to explore the deep geodynamic background of their formation. A series of granitic porphyry dykes have been found in the mélange zone of the Asa region in southern Tibet, whose genesis may be closely related to the evolution of the Meso-Tethyan Ocean. Regional geodynamic evolution is investigated by whole-rock geochemical analysis, zircon U–Pb dating and Lu–Hf isotopic analysis of two porphyritic granites. The Asa porphyritic granites have high SiO2 (74.29–78.65 wt %) and alkalis (Na2O + K2O = 6.51–9.35 wt %) contents, and low Al2O3 (11.60–14.51 wt %), CaO (0.04–0.19 wt MgO (0.01–0.10 wt %) contents. They are enriched in Zr, Nb, Ce, Y and Hf and depleted in Ti, Ba, Sr and P, consistent with A-type granites. The samples are relatively rich in LREEs, with LREE/HREE ratios of 1.73–3.04. They display negative Eu anomalies (Eu/Eu* = 0.24–0.28) and obvious Ce anomalies in some samples. Zircon U–Pb analyses show that the porphyritic granites formed in late Early Cretaceous time, 107.4 to 105.5 Ma. Zircon εHf(t) values are in the range of 6.9 to 12.0. These data indicate that the porphyritic granites were sourced from interaction between mantle-derived and juvenile lower crust-derived melts, with the addition of oceanic sediment-derived melts. This occurred when the subducting Bangong–Nujiang oceanic crust split to create a slab window. Rising asthenosphere triggered re-melting of lower crust basalts, resulting in the formation of the late Early Cretaceous A-type granites around Asa.
We formulate a
-Schur algebra associated with an arbitrary
-invariant finite set
of integral weights for a complex simple Lie algebra with Weyl group
. We establish a
-Schur duality between the
-Schur algebra and Hecke algebra associated with
. We then realize geometrically the
-Schur algebra and duality and construct a canonical basis for the
-Schur algebra with positivity. With suitable choices of
in classical types, we recover the
-Schur algebras in the literature. Our
-Schur algebras are closely related to the category
, where the type
is studied in detail.
B vitamins (including folate, vitamin B2, vitamin B6 and vitamin B12) and methionine are essential for methylation reactions, nucleotide synthesis, DNA stability and DNA repair. However, epidemiological evidence among Chinese populations is limited. The objective of this study was to evaluate B vitamins and methionine in relation to colorectal cancer risk in a Chinese population. A case–control study was conducted from July 2010 to April 2019. A total of 2502 patients with colorectal cancer were recruited along with 2538 age- (5-year interval) and sex-matched controls. Dietary data were collected using a validated FFQ. Multivariable logistic regression was used to assess OR and 95 % CI. The intake of folate, vitamin B2, vitamin B6 and vitamin B12 was inversely associated with colorectal cancer risk. The multivariable OR for the highest quartile v. the lowest quartile were 0·62 (95 % CI 0·51, 0·74; Ptrend < 0·001) for folate, 0·46 (95 % CI 0·38, 0·55; Ptrend < 0·001) for vitamin B2, 0·55 (95 % CI 0·46, 0·76; Ptrend < 0·001) for vitamin B6 and 0·72 (95 % CI 0·60, 0·86; Ptrend < 0·001) for vitamin B12. No statistically significant association was found between methionine intake and colorectal cancer risk. Stratified analysis by sex showed that the inverse associations between vitamin B12 and methionine intake and colorectal cancer risk were found only among women. This study indicated that higher intake of folate, vitamin B2, vitamin B6 and vitamin B12 was associated with decreased risk of colorectal cancer in a Chinese population.
The rhoptry kinase 18 of Toxoplasma gondii (TgROP18) has been identified as a key virulence factor that allows the parasite to escape from host immune defences and promotes its proliferation in host cells. Although much research is focused on the interaction between host cells and TgROP18, the development of monoclonal antibodies (mAbs) against TgROP18 has not been reported till date. To produce mAbs targeting TgROP18, two hybridomas secreting mAbs against TgROP18, designated as A1 and T2, were generated using cell fusion technology. The subtypes of the A1 and T2 mAbs were identified as IgG3 λ and IgM κ, and peptide scanning revealed that the core sequences of the antigenic epitopes were 180LRAQRRRSELVFE192 and 351NYFLLMMRAEADM363, respectively. The T2 mAb specifically reacted with both T. gondii type I and Chinese I, but not with T. gondii type II, Plasmodium falciparum or Schistosoma japonicum. Finally, the sequences of heavy chain and light chain complementarity-determining regions of T2 were amplified, cloned and characterized, making the modification of the mAb feasible in the future. The development of mAbs against TgROP18 would aid the investigation of the molecular mechanisms underlying the modulation of host cellular functions by TgROP18, and in the development of strategies to diagnose and treat Toxoplasmosis.
Regarding the effect of composition on the mechanical properties of intermetallic phases such as Laves phases, there is conflicting information in the literature. Some authors observed defect hardening when deviating from stoichiometric Laves phase composition, whereas others find defect softening. Here, we present a systematic investigation of the defect state, hardness, and elastic modulus of cubic and hexagonal NbCo2 Laves phases as a function of crystal structure and composition. For this purpose, diffusion couples were prepared which exhibit diffusion layers of the cubic C15 and hexagonal C14 and C36 NbCo2 Laves phases, with concentration gradients covering their entire homogeneity ranges from 24 to 37 at.% Nb. Direct observations of dislocations and stacking faults in the diffusion layers as a function of composition were performed by electron channeling contrast imaging, and the hardness and elastic modulus were probed in the diffusion layers along the concentration gradients by nanoindentation.
Losing one's only child is a major traumatic life event that may lead to post-traumatic stress disorder (PTSD); however, the underlying mechanisms of its psychological consequences remain poorly understood. Here, we investigated subregional hippocampal functional connectivity (FC) networks based on resting-state functional magnetic resonance imaging and the deoxyribonucleic acid methylation of the human glucocorticoid receptor gene (NR3C1) in adults who had lost their only child.
A total of 144 Han Chinese adults who had lost their only child (51 adults with PTSD and 93 non-PTSD adults [trauma-exposed controls]) and 50 controls without trauma exposure were included in this fMRI study (age: 40–67 years). FCs between hippocampal subdivisions (four regions in each hemisphere: cornu ammonis1 [CA1], CA2, CA3, and dentate gyrus [DG]) and methylation levels of the NR3C1 gene were compared among the three groups.
Trauma-exposed adults, regardless of PTSD diagnosis, had weaker positive FC between the left hippocampal CA1, left DG, and the posterior cingulate cortex, and weaker negative FC between the right CA1, right DG, and several frontal gyri, relative to healthy controls. Compared to non-PTSD adults, PTSD adults showed decreased negative FC between the right CA1 region and the right middle/inferior frontal gyri (MFG/IFG), and decreased negative FC between the right DG and the right superior frontal gyrus and left MFG. Both trauma-exposed groups showed lower methylation levels of the NR3C1 gene.
Adults who had lost their only child may experience disrupted hippocampal network connectivity and NR3C1 methylation status, regardless of whether they have developed PTSD.
The aim of this research was to identify variation in the yak lipin-1 gene (LPIN1) and determine whether this variation affects milk traits. PCR-single stranded conformational polymorphism (PCR-SSCP) analysis was used to detect variation in the 5′ untranslated region of LPIN1 in 500 yaks from four populations: Tianzhu white yaks, Qinghai yaks, wild × domestic-cross yaks and Gannan yaks. Four unique PCR-SSCP patterns, representing four different DNA sequence variants (named A, B, C and D), were observed. These contained six single nucleotide polymorphisms. Female Gannan yaks with BC genotype produced milk with a higher fat content (P < 0.001) and total milk solids (P < 0.001), than those with the AA, AB and BB genotypes. These results would suggest that LPIN1 is having an effect on yak milk fat synthesis.