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Modal global linear stability analysis of thermal convection is performed with the linearized lattice Boltzmann method (LLBM). The onset of Rayleigh–Bénard convection in rectangular cavities with conducting and adiabatic sidewalls and the instability of two-dimensional (2-D) and three-dimensional (3-D) natural convection in cavities are studied. The method of linearizing the local equilibrium probability distribution function that was first proposed by Pérez et al. (Theor. Comp. Fluid Dyn., vol. 31, 2017, pp. 643–664) is extended to solve the coupled linear Navier–Stokes equations together with the linear energy equation in this work. A multiscale analysis is also performed to recover the macroscopic linear Navier–Stokes equations from the discrete lattice Boltzmann equations for both the single and multiple relaxation time models. The present LLBM is implemented in the framework of the Palabos library. It is validated by calculating the linear critical value of 2-D natural convection that the LLBM with the multiple relaxation time model has an error less than 1 % compared with the spectral method. The instability mechanism of the flow is explained by kinetic energy transfer analysis. It is shown that the buoyancy mechanism and inertial mechanism tend to stabilize the Hopf bifurcation of the 2-D natural convection at Pr < 0.08 and Pr > 1, respectively. For 3-D natural convection, subcritical bifurcation of the Hopf type is found for low-Prandtl-number fluids (Pr < 0.1).
Widely distributed Mid-Neoproterozoic mafic rocks of the Qilian – Qaidam – East Kunlun region record the tectonic evolution of the northeastern Tibetan Plateau. This study presents whole-rock geochemistry, zircon U–Pb geochronology and Hf isotopes for the Xialanuoer gabbros of the central South Qilian Belt (SQB). Zircon laser ablation – inductively coupled plasma – mass spectrometry (LA-ICP-MS) U–Pb dating indicates that the gabbros were emplaced at ca. 738 Ma, indicating they are contemporaneous with mafic magmatism elsewhere in the northeastern Tibetan Plateau. The gabbros have low SiO2, Cr and Ni contents and Mg# values, are relatively enriched in light rare-earth elements (LREEs) and depleted in high-field-strength elements (HFSEs; e.g. Nb and Ta), have no positive Zr or Hf anomalies and have relatively high Nb/Ta but low Nb/La ratios. These data indicate that the Xialanuoer gabbros formed from calc-alkaline basaltic magmas that were originally generated by the partial melting of an enriched mantle of type-I (EMI-type) enriched region of the lithospheric mantle, underwent little to no crustal contamination prior to their emplacement, and have within-plate basalt geochemical affinities. Combining these data with the presence of widespread contemporaneous continental rift-related magmatism and sedimentation in the North Qilian, Central Qilian, South Qilian, Quanji, North Qaidam and East Kunlun regions suggests that the northeastern Tibetan Plateau underwent Mid-Neoproterozoic continental rifting, which also affected other Rodinian blocks (e.g. Tarim, South China, Australia, North America and Southern Africa).
Mammal sex determination depends on whether the X sperm or Y sperm binds to the oocyte during fertilization. If the X sperm joins in oocyte, the offspring will be female, if the Y sperm fertilizes, the offspring will be male. Livestock sex control technology has tremendous value for livestock breeding as it can increase the proportion of female offspring and improve the efficiency of livestock production. This review discusses the detailed differences between mammalian X and Y sperm with respect to their morphology, size, and motility in the reproductive tract and in in vitro conditions, as well as ’omics analysis results. Moreover, research progress in mammalian sex control technology has been summarized.
Natural enemies that impact pest populations must be understood in order to build integrated pest control strategies and to understand the most important aspects affecting pest dynamics. Haloxylon ammodendron (C. A. Mey.) Bunge is an important perennial plant species extensively used in sand stabilization and wind prevention in arid areas. This study aimed to determine the main defoliators that damage H. ammodendron and the parasitoid complex associated with them. Twelve species of defoliators were found in Northern Xinjiang, and Teia dubia (Tauscher) (Lepidoptera: Lymantriidae), Scrobipalpa sp. (Lepidoptera: Gelechiidae), and Eucharia festiva Hüfnagel (Lepidoptera: Arctiidae) were the dominant pests. T. dubia is the predominant defoliator with three generations a year. Northwest China, Central Asia, and the Mediterranean region are potentially suitable habitats for T. dubia in the world, while Xinjiang is the primary distribution area in China. Parasitoids belonging to seven species and four families were reared from the larvae of T. dubia, they were all endoparasitoids and koinobiont. Cotesia sp. (Hymenoptera: Braconidae) is the dominant parasitoid and prefer to parasitic in the 3rd–5th instar larvae. The present study provides the basis for understanding the species composition and natural enemies of lepidopteran defoliators. It will be an effective tool for the integrated pest management programs of H. ammodendron forest.
No relevant studies have yet been conducted to explore which measurement can best predict the survival time of patients with cancer cachexia. This study aimed to identify an anthropometric measurement that could predict the 1-year survival of patients with cancer cachexia. We conducted a nested case–control study using data from a multicentre clinical investigation of cancer from 2013 to 2020. Cachexia was defined using the Fearon criteria. A total of 262 patients who survived less than 1 year and 262 patients who survived more than 1 year were included in this study. Six candidate variables were selected based on clinical experience and previous studies. Five variables, BMI, mid-arm circumference, mid-arm muscle circumference, calf circumference and triceps skin fold (TSF), were selected for inclusion in the multivariable model. In the conditional logistic regression analysis, TSF (P = 0·014) was identified as a significant independent protective factor. A similar result was observed in all patients with cancer cachexia (n 3084). In addition, a significantly stronger positive association between TSF and the 1-year survival of patients with cancer cachexia was observed in participants aged > 65 years (OR: 0·94; 95 % CI 0·89, 0·99) than in those aged ≤ 65 years (OR: 0·96; 95 % CI 0·93, 0·99; Pinteraction = 0·013) and in participants with no chronic disease (OR: 0·92; 95 % CI 0·87, 0·97) than in those with chronic disease (OR: 0·97; 95 % CI 0·94, 1·00; Pinteraction = 0·049). According to this study, TSF might be a good anthropometric measurement for predicting 1-year survival in patients with cancer cachexia.
The association between blood transfusion and ventilator-associated events (VAEs) has not been fully understood. We sought to determine whether blood transfusion increases the risk of a VAE.
Nested case-control study.
This study was based on a registry of healthcare-associated infections in intensive care units at West China Hospital system.
1,657 VAE cases and 3,293 matched controls were identified.
For each case, 2 controls were randomly selected using incidence density sampling. We defined blood transfusion as a time-dependent variable, and we used weighted Cox models to calculate hazard ratios (HRs) for all 3 tiers of VAEs.
Blood transfusion was associated with increased risk of ventilator-associated complication-plus (VAC-plus; HR, 1.47; 95% CI, 1.22–1.77; P <.001), VAC-only (HR, 1.29; 95% CI, 1.01–1.65; P = .038), infection-related VAC-plus (IVAC-plus; HR, 1.78; 95% CI, 1.33–2.39; P < .001), and possible ventilator-associated pneumonia (PVAP; HR, 2.10; 95% CI, 1.10–3.99; P = .024). Red blood cell (RBC) transfusion was also associated with increased risk of VAC-plus (HR, 1.34; 95% CI, 1.08–1.65; P = .007), IVAC-plus (HR, 1.70; 95% CI, 1.22–2.36; P = .002), and PVAP (HR, 2.49; 95% CI, 1.17–5.28; P = .018). Compared to patients without transfusion, the risk of VAE was significantly higher in patients with RBC transfusions of >3 units (HR, 1.73; 95% CI, 1.25–2.40; P = .001) but not in those with RBC transfusions of 0–3 units.
Blood transfusions were associated with increased risk of all tiers of VAE. The risk was significantly higher among patients who were transfused with >3 units of RBCs.
To investigate the clinical impact of ventilator-associated events (VAEs) on adverse prognoses and risk factors for mortality among intensive care unit (ICU) patients receiving invasive mechanical ventilation (IMV) based on an ICU healthcare-associated infection (ICU-HAI) registry.
A cohort study was conducted based on an ICU-HAI registry including 30,830 patients between 2015 and 2018.
The study was conducted using data from 5 adult ICUs of a referral hospital.
Adult patients in the ICU-HAI registry who received ≥4 consecutive IMV days.
Clinical outcomes and mortality risk factors for VAEs were analyzed using propensity score matching (PSM), multivariate regression models, and sensitivity analyses.
Of 6,426 included patients, 1,803 developed 1,899 VAEs. After PSM, patients with VAEs did have prolonged length of stay in the ICU and in the hospital, increased hospitalization costs, longer days on mechanical ventilation, higher proportion of ≥9 days on mechanical ventilation, higher rate of failure in extubating mechanical ventilation, and excess all-cause mortality in the ICU. Older age (adjusted OR [aOR], 1.02), higher APACHE II score on ICU admission (aOR, 1.06), pneumonia (aOR, 1.49), blood transfusion (aOR 1.43), immunosuppressive drugs (aOR, 1.69), central-line catheter (aOR, 2.06), and ≥2 VAEs in the ICU (aOR, 1.99) were associated with higher risks for all-cause mortality in an ICU.
Patients with VAEs indeed had poorer clinical outcomes. Older age, higher APACHE II score on ICU admission, pneumonia, blood transfusion, immunosuppressive drugs, central-line catheter, and ≥2 VAEs in the ICU were risk factors for all-cause mortality of VAE patients in the ICU.
Calcification within breast cancer is a diagnostically significant radiological feature that generally consists of hydroxylapatite. Samples from 30 cases of breast carcinoma with calcification were investigated using optical microscopy, energy-dispersive X-ray analysis, transmission-electron microscopy, Fourier-transform infrared spectroscopy, Raman spectroscopy, synchrotron radiation X-ray diffraction and X-ray fluorescence. Under optical microscopy, the calcifications were found to consist of either irregular aggregates with widths > 200 μm or spherical aggregates similar to psammoma bodies with an average diameter of 30 μm. Transmission-electron microscopy showed that short columnar or dumbbell-shaped crystals with widths of 10–15 nm and lengths of 20–50 nm were the most common morphology; spherical aggregates (~1 μm in diameter) with amorphous coatings of fibrous nanocrystals were also observed. Results indicated that hydroxylapatite was the dominant mineral phase in the calcifications, and both CO32– and cation substitutions (Na, Mg, Zn, Fe, Sr, Cu and Mn) were present in the hydroxylapatite structure. Fourier-transform infrared spectra show peaks at 872 and 880 cm–1 indicating that CO32– substituted both the OH– (A type) and PO43– (B type) sites of hydroxylapatite, making it an A and B mixed type. The ratio of B- to A-type substitution was estimated in the range of 1.1–18.7 from the ratio of peak intensities (I872/I880), accompanied with CO32– contents from 1.1% to 14.5%. Trace arsenic, detected in situ by synchrotron radiation X-ray fluorescence was found to be distributed uniformly in the calcifications in the form of AsO43– substituting for PO43–. It is therefore proposed that identifying these trace elements in breast cancer calcifications may be promising for future clinical diagnostics.
Despite high altitude was implicated in adverse birth outcomes, there remained a paucity of evidence on low-to-medium altitude effect. This study aimed to explore the association of low-to-medium altitude with birth outcomes. A population-based cross-sectional survey was performed using a stratified multistage random sampling method among women with their infants born during 2010–2013 in Northwestern China. Altitude was determined in meters based on the village or community of the mother’s living areas. Birth outcomes involved birth weight, gestational age, and small for gestational age (SGA). Generalized linear models were fitted to investigate the association of altitude with birth outcomes. Moreover, the dose–response relationship between altitude and birth outcomes was evaluated with a restricted cubic spline function. A total of 27 801 women with their infants were included. After adjusting for potential confounders, every 100-m increase in the altitude was associated with reduced birth weight by 6.4 (95% CI −8.1, −4.6) g, the slight increase of gestational age by 0.015 (95% CI 0.010, 0.020) week, and an increased risk of SGA birth (odds ratio 1.03, 95% CI 1.02, 1.04). Moreover, there was an inversely linear relationship between altitude and birth weight (P for overall < 0.001 and P for nonlinear = 0.312), and a positive linear relationship between altitude and SGA (P for overall < 0.001 and P for nonlinear = 0.194). However, a nonlinear relationship was observed between altitude and gestational age (P for overall < 0.001 and P for nonlinear = 0.010). The present results suggest that low-to-medium altitude is possibly associated with adverse birth outcomes.
Comprehensive screening of rice (Oryza sativa L. subsp. japonica Kato) germplasm resources with different nitrogen (N) efficiency levels is effective for improving N use efficiency (NUE) while reducing pollution and providing high quality, yield, and efficiency agriculture. We investigated 14 indices of 38 varieties under three N application levels to assess differences among genotypes. Rice varieties were classified for screening and identifying N efficient. Descriptive statistical analysis results indicated significant differences in relative yield, and also in NUE indices (agronomic utilization rate and partial productivity of N fertilizer). The genotype main effects and genotype–environment interaction effects (GGE) biplot analysis was used to evaluate suitable varieties, compare the stable and high yield capabilities of different varieties, find the ideal variety, and describe the correlation, discrimination and representativeness of the indices under different N application levels. Descriptive statistical, discrimitiveness and representativeness and factor analysis were used to select indices, in which the panicle number per plant and soil and plant analyzer development (SPAD) value were the key indices for evaluation and identification. Heatmap and hierarchical cluster analysis based on the average value of evaluation indices, and scatter plot based on the comprehensive value of N efficiency (P) according to formula showed that all varieties could be divided into five types under different N treatments. Our findings work toward developing N efficient rice varieties to improve NUE, reduce N fertilizer application and thus N waste, consequently mitigating the effects of rice production on the environment to ensure food security and sustainable agricultural development.
OBJECTIVES/GOALS: Vitamin D [25(OH)D], known to have anti-inflammatory and anti-fibrotic effects in other tissues, may also impact adipose tissue. We designed parallel studies in humans and rodents to define the effects of vitamin D on adipose tissue inflammation and fibrosis, and on systemic insulin resistance. METHODS/STUDY POPULATION: We performed a randomized, double-blinded placebo-controlled trial to examine the effects of repleting vitamin D at to two levels (to >30 ng/ml and to > 50 ng/ml) in 25(OH)D-deficient (<20 ng/ml), insulin resistant, overweight-to-obese humans (n = 19). A comprehensive study of whole-body insulin action was undertaken with euglycemic stepped hyperinsulinemic clamp studies, both before (1st visit) and after administration of vitamin D or placebo (2nd visit and 3rd visit). Adipose tissue fibrosis and inflammation were quantified by ‘real-time’ rt-PCR and immunofluorescence. To determine whether vitamin D’s effects are mediated through adipocytes, we performed hyperinsulinemic clamp studies and adipose tissue analysis in an adipocyte-specific vitamin D receptor knockout (VDR KO) mouse model. RESULTS/ANTICIPATED RESULTS: 25(OH)D repletion (to >30 ng/ml) was associated with reductions in adipose tissue expression of inflammatory (0.6-0.7-fold decreased expression of TNF-α, IL-6, iNOS and PAI-1) and pro-fibrotic (0.4-0.8-fold decreased expression of TGF-β1, HiF1α, Collagen I, V, VI and MMP7) factors, decreased collagen VI immunofluorescence (p = 0.02) and improved hepatic insulin sensitivity in humans, with suppression of endogenous glucose production (EGP) (1.28 ± 0.20 vs 0.88 ± 0.18 mg/kg/min, p = 0.03). Compared to wild type (WT), VDR KO mice exhibited increased adipose tissue expression of several pro-inflammatory (Tnf-α, iNos, Pai-1, Mcp-1 and F4/80; 4-10 fold) and pro-fibrotic genes (Tgf-β1, Collagen VI, and Tsp1; 2-4 fold), in concert with hepatic insulin resistance (EGP 10 ± 3 vs 3 ± 2 mg/kg/min in WT, p = 0.021). DISCUSSION/SIGNIFICANCE OF IMPACT: Collectively, these complementary human and rodent studies establish a beneficial role of vitamin D to improve hepatic insulin resistance, likely by restraining adipose tissue inflammation and fibrosis. Thus, normalizing 25(OH)D levels could have metabolic benefits in targeted individuals. CONFLICT OF INTEREST DESCRIPTION: N/A
BaxSr(1−x)TiO3 (BST) thin films were fabricated on a Ti substrate using micro-arc oxidation (MAO) in an aqueous solution with the addition of 0.6 M Ba(OH)2, 0.4 M Sr(OH)2, and 0.05 M EDTA. The morphology, composition, and electrical properties of BST films prepared under different processing times were characterized, and MAO growth characteristics of BST films were discussed. Results indicate that dielectric and ferroelectric properties of BST films are positively correlated with surface morphology dependent on MAO spark patterns. To obtain a smooth and compact film, the large spark stage should be avoided. During MAO processes, elements from the substrate and electrolyte solution migrate in opposite directions under an electric field, resulting in Ba, Sr, Ti, and O elements exhibiting a gradient distribution between the BST film and the Ti substrate. BST film prepared using MAO is composed of two layers: an outer loose layer and an inner dense layer. In addition, because of the position of discharge breakdown continually changing, the interface between the film and the substrate is uneven. As MAO processing time increases, BST film thickness increases and ferroelectric property improves. When processing time is 15 min, the residual polarization intensity (2Pr) of the BST film is about 4.9 μC/cm2.
Sources and implications of black carbon (BC) and mineral dust (MD) on two glaciers on the central Tibetan Plateau were estimated based on in situ measurements and modeling. The results indicated that BC and MD accounted for ~11 ± 1% and 4 ± 0% of the albedo reduction relative to clean snow, while the radiative forcing varied between 11 and 196 and 1–89 W m−2, respectively. Assessment of BC and MD contributions to the glacier melt can reach up 88 to 434 and 35 to 187 mm w.e., respectively, contributing ~9–23 and 4–10% of the total glacier melt. A footprint analysis indicated that BC and MD deposited on the glaciers originated mainly from the Middle East, Central Asia, North China and South Asia during the study period. Moreover, a potentially large fraction of BC may have originated from local and regional fossil fuel combustion. This study suggests that BC and MD will enhance glacier melt and provides a scientific basis for regional mitigation efforts.
NGC 300 is a near-optical twin of the Local Group galaxy M33, which are benchmarks for understanding late-type spiral galaxies. They are two bulgeless and low-mass spiral galaxies in different environments. In order to explore the common properties and differences between the two nearby low-mass systems, we first use the simple chemical evolution model to explore the star formation history (SFH) of NGC300 and M33, and then compare the feasible model predicted SFH of NGC 300 with that of M33. Through comparing the SFHs between them, it can be found that the mean stellar age of NGC 300 is older than that of M33, there is a recent lack of primordial gas infall onto the disk of NGC 300, recent star formation along the disk of NGC 300 is less active than that of M33, and the local environment may play a key role in the secular evolution of a galaxy.
The experimental study on thermocapillary convection in liquid bridges of large Prandtl number has been carried out on Tiangong-2 in space. The purpose of these experiments is to study the oscillation instability of thermocapillary convection, and to discover and recognize the mechanism of destabilization of thermocapillary convection in the microgravity environment in space. In this paper, the geometry of a half-floating-zone liquid bridge is featured by the aspect ratio Ar and volume ratio Vr, and its influence on critical conditions of oscillatory thermocapillary convection is studied. More than 700 sets of space experiments have been finished. The critical conditions and oscillation characteristics of thermocapillary convection instability in the Ar–Vr parameter space have been fully obtained under microgravity conditions for the first time. It is found that the Ar–Vr parameter space can be divided into two regions of different critical conditions and oscillation characteristics: the region of low frequency oscillation, and the region of high frequency oscillation. More importantly, we obtain the complete configuration of these two stability neutral curves, and find that the low frequency mode is a ‘’ type curve. Based on this, we discuss the influence of heating rate on the oscillation mode. It is found that the heating rate affects the selection of critical mode, which results in a jump change of critical temperature difference. The findings of this study are helpful to better understand the critical modes and transition processes of thermocapillary convection in liquid bridges with different configurations.
Light-absorbing impurities (LAIs, e.g. black carbon (BC), organic carbon (OC), mineral dust (MD)) deposited on snow cover reduce albedo and accelerate its melting. Northern Xinjiang (NX) is an arid and semi-arid inland region, where snowmelt leads to frequent floods that have been a serious threat to local ecological security. There is still a lack of quantitative assessments of the effects of LAIs on snowmelt in the region. This study investigates spatial variations of LAIs in snow and its effect on snow albedo, radiative forcing (RF) and snowmelt across NX. Results showed that concentrations of BC, OC (only water-insoluble OC), MD ranged from 32 to 8841 ng g−1, 77 to 8568 ng g−1 and 0.46 to 236 µg g−1, respectively. Weather Research and Forecasting Chemistry model suggested that residential emission was the largest source of BC. Snow, Ice, and Aerosol Radiative modelling showed that the average contribution of BC and MD to snow albedo reduction was 17 and 3%, respectively. RF caused by BC significantly exceeded RF caused by MD. In different scenarios, changes in snow cover duration (SCD) caused by BC and MD decreased by 1.36 ± 0.61 to 6.12 ± 3.38 d. Compared with MD, BC was the main dominant factor in reducing snow albedo and SCD across NX.
Cinnamomum chago is a woody species of the family Lauraceae endemic to Yunnan province, China, previously known from only one location, and categorized as a Plant Species with Extremely Small Population. We surveyed to determine the distribution and population size of C. chago, characterize its habitat, identify any threats, assess its conservation status, and provide guidelines for its management and conservation. During 2014–2017 we found only 64 mature C. chago, in five locations. These small, fragmented populations occur along Lancang River in Dali Prefecture at altitudes of 2,200–2,400 m. The species' extent of occurrence is c. 923 km2, with an area of occupancy of c. 60 km2. The habitat of the species has been degraded by expansion of pastoral activities and deforestation. We recommend categorization of C. chago as Endangered on the IUCN Red List, prevention of the collection of seeds and wood of the species, protection and monitoring, and ex situ propagation for future reintroductions.