Aridification in a farming-pastoral ecotone of northern China from 2 perspectives: Climate and soil.

Understanding the impact of climate change on terrestrial wet and dry changes and the relationship between the two is of great significance to the sustainable development of terrestrial ecosystems. The farming-pastoral ecotone of northern China (FPENC) is an area that is sensitive to climate change, suffering from perennial drought and a clear aridification trend. Unlike previous single-factor, single-timescale studies, we identified aridification in the region based on a dataset established by remote sensing and ground-based monitoring stations from a combination of two perspectives: climate and soil. The results show that, in terms of climate, the period from 2000 to 2019 was the driest in the region during the last 120 years , and the summer drought was the most severe and shifted from a summer to spring drought; in terms of soil, the soil aridification trend in the region was severe, with 16.1% of the areas becoming significantly drier (P < 0.1) among the years and 41.6% in spring, respectively. Similar to climate change, soils exhibited recessive aridification due to the counterbalancing effect of the dry and wet seasons within the year. Then the coupling relationship between climate change and soil aridification was established in time and space. Moreover, the spatiotemporal response patterns of both were obtained. The results showed that the frequency of soil drought under meteorological drought conditions showed an increasing trend and that the sensitivity of soil drought occurrence increased. Among them, the effect of precipitation on relative soil moisture (RSM) was immediate, and the effect of prolonged warming on RSM is greater. The area of soil aridification that was caused by climatic aridification in spring accounted for 13.7% of the entire area. The regional aridification research mode proposed in this paper can provide ideas for subsequent studies.

Sex differences in outcomes and risk factors among elderly patients with ischemic stroke.

We aimed to investigate the sex differences in the clinical characteristics and risk factors for adverse outcomes among elderly patients with atherosclerotic stroke. We recruited 942 consecutive patients with atherosclerotic stroke aged 75 years and older between January 2008 and December 2013 from Jiamusi University First Hospital, China. Stroke subtype, severity, risk factors, and outcomes (mortality, dependency, and recurrence) at 3 and 12 months after stroke were recorded and assessed. Mortality at 3 months after stroke was higher in men than in women. Stroke severity was an independent risk factor for mortality, dependency, and recurrence at 3 and 12 months after stroke in both men and women. However, the presence of total anterior circulation infarct and obesity protected against mortality at 3 months after stroke in men, while total anterior circulation infarct was a risk factor for dependency at 3 months after stroke in women. In women, positive associations were found between fasting plasma glucose level and mortality at 3 months after stroke and between hypertension, atrial fibrillation, and recurrence at 12 months after stroke. These findings suggest that it is crucial to control the primary risk factors individually by sex, especially regarding hypertension and atrial fibrillation management, to improve secondary prevention of stroke among the elderly and reduce the burden of stroke in China.

Wnt5a attenuates hypoxia-induced pulmonary arteriolar remodeling and right ventricular hypertrophy in mice.

Hypoxic pulmonary hypertension (HPH), which is characterized by pulmonary arteriolar remodeling and right ventricular hypertrophy, is still a life-threatening disease with the current treatment strategies. The underlying molecular mechanisms of HPH remain unclear. Our previously published study showed that Wnt5a, one of the ligands in the Wnt family, was critically involved in the inhibition of hypoxia-induced pulmonary arterial smooth muscle cell proliferation by downregulation of ß-catenin/cyclin D1 in vitro. In this study, we investigated the possible functions and mechanisms of Wnt5a in HPH in vivo. Recombinant mouse Wnt5a (rmWnt5a) or phosphate buffered saline (PBS) was administered to male C57/BL6 mice weekly from the first day to the end of the two or four weeks after exposed to hypoxia (10% O2). Hypoxia-induced pulmonary hypertension was associated with a marked increase in ß-catenin/cyclin D1 expression in lungs. Right ventricular systolic pressure and right ventricular hypertrophy index were reduced in animals treated with rmWnt5a compared with PBS. Histology showed less pulmonary vascular remodeling and right ventricular hypertrophy in the group treated with rmWnt5a than with PBS. Treatment with rmWnt5a resulted in a concomitant reduction in ß-catenin/cyclin D1 levels in lungs. These data demonstrate that Wnt5a exerts its beneficial effects on HPH by regulating pulmonary vascular remodeling and right ventricular hypertrophy in a manner that is associated with reduction in ß-catenin/cyclin D1 signaling. A therapy targeting the ß-catenin/cyclin D1 signaling pathway might be a potential strategy for HPH treatment.

Higher level of heme oxygenase-1 in patients with stroke than TIA.

BACKGROUND: There is a reverse relationship between serum bilirubin level and incidence of stroke, heme oxygenase-1 (HO-1) can catalyze heme into bilirubin, it is unknown the association of HO-1 level with risk of stroke. METHODS: Sixty patients with stroke and fifty patients with transient ischemic attack (TIA) were recruited. Serum level of HO-1, total and direct bilirubin, alanine transaminase, live function, lipid profile and infection status of patients were measured. RESULTS: Significant differences were found between two groups in terms of serum levels of HO-1 (163.6±58.7 vs. 141.2±49.7, P=0.032), total bilirubin (10.1±4.6 vs. 15.8±2.7, P<0.001), direct bilirubin (3.2±2.1 vs. 5.9±1.2, P<0.001), fasting glucose (6.7±3.1 vs. 4.9±1.3, P<0.001), cholesterol (4.4±1.1 vs. 3.9±0.8, P=0.005) and diastolic blood pressure (DBP) (84.9±9.4 vs. 81.3±9.2, P=0.046). In multivariate analysis, serum direct bilirubin (OR, 2.83; P<0.001), total bilirubin (OR, 1.82, P=0.001), DBP (OR, 0.88, P=0.041), and fasting glucose (OR, 0.34, P<0.001) were independent predictors of stroke. CONCLUSIONS: Serum HO-1 level is higher in patients with stroke than TIA, but the bilirubin level is lower in patients with stroke than TIA and is an independent predictor of stroke. Further studies are warranted to clarify the underlying link among HO-1, bilirubin and stroke.

mTORC1 is involved in hypoxia-induced pulmonary hypertension through the activation of Notch3.

Hypoxia-induced pulmonary hypertension (HPH) is a clinical syndrome associated with high morbidity and mortality. However, the underlying mechanisms remain unclear. Both the mammalian target of rapamycin (mTOR) and the Notch3 signaling pathways have been reported to be involved in HPH; however, it is unknown whether there is a connection between these two signaling pathways in HPH. This study was designed to investigate the relationship between mTOR and Notch3 in HPH. After treatment with 10% O2 for 4 weeks, male C57BL/6 mice developed HPH with gradually increased right ventricular systolic pressure (RVSP), right ventricular hypertrophy index (RVHI), and pulmonary arteriolar remodeling accompanied by the activation of mTOR complex 1 (mTORC1) and Notch3 in the lung tissue and pulmonary arterioles. Pretreatment with the mTORC1 inhibitor rapamycin not only alleviated pulmonary arterial pressure and pulmonary arteriolar remodeling but also suppressed hypoxia-induced mTORC1 and Notch3 activation. Prophylactic N-[N-(3,5-difluorophenacetyl)-L-alanyl]-S-phenylglycine t-butyl ester (DAPT) administration, a Notch signaling inhibitor, protected against the effects of hypoxia. These in vivo data were confirmed by in vitro experiments on human pulmonary arterial smooth muscle cell (PASMC) exposed to 3% O2 . Furthermore, overexpression of Notch3 intracellular domain partially abrogated the inhibitory effects of rapamycin on human PASMC proliferation. These data indicate that both mTORC1 and Notch3 signaling are involved in HPH and the downstream effects of mTORC1 activation in HPH are partially dependent on the activation of Notch3 signaling.

Evidence for a crucial role played by oxygen vacancies in LaMnO3 resistive switching memories.

LaMnO(3) (LMO) films are deposited on SrTiO(3):Nb (0.8 wt%) substrates under various oxygen pressures to obtain different concentrations of oxygen vacancies in the films. The results of X-ray diffraction verify that with a decrease of the oxygen pressure, the c-axis lattice constant of the LMO films becomes larger, owing to an increase of the oxygen vacancies. Aberration-corrected annular-bright-field scanning transmission electron microscopy with atomic resolution and sensitivity for light elements is used, which clearly shows that the number of oxygen vacancies increases with the decrease of oxygen pressure during fabrication. Correspondingly, the resistive switching property becomes more pronounced with more oxygen vacancies in the LMO films. Furthermore, a numerical model based on the modification of the interface property induced by the migration of oxygen vacancies in these structures is proposed to elucidate the underlying physical origins. The calculated results are in good agreement with the experimental data, which reveal from a theoretical point of view that the migration of oxygen vacancies and the variation of the Schottky barrier at the interface with applied bias dominate the resistive switching characteristic. It is promising that the resistive switching property in perovskite oxides can be manipulated by controlling the oxygen vacancies during fabrication or later annealing in an oxygen atmosphere.

Molecular cloning and sequence analysis of heavy- and light-chain variable region genes of anti-CD71 monoclonal antibody.

OBJECTIVE: To clone heavy-chain and light-chain variable region (VH and VL) gene of mouse-anti-human CD71 monoclonal antibody (mAb). METHOD: One-step method was used to extract total RNA, and a set of oligonucleotide primers were designed to amplify the cDNAs with reverse transcriptase-polymerase chain reaction (RT-PCR), and the resultant products were respectively cloned into PMD18-T vector and their sequences analyzed. RESULTS: The PCR product obtained with the oligonucleotide primers for the variable region of mouse immunoglobulin heavy chain was about 350 bp and that with oligonucleotide primers for the light chain was about 320 bp, and their DNA sequences were determined. CONCLUSION: The length of the cloned heavy chain variable region was 348 bp, belonging to mouse heavy-chain subgroup II(A); the light-chain variable region was 336 bp that belongs to mouse kappa light-chain subgroup II.