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The carbon (C) cycling in semiarid and arid areas remains largely unexplored, despite the wide distribution of drylands globally. Rehabilitation practices have been carried out in many desertified areas, but information on the C sequestration capacity of recovering vegetation is still largely lacking. Using the eddy-covariance technique, we measured the net ecosystem CO2 exchange (NEE) over a recovering shrub ecosystem in northwest China throughout 2012 in order to (1) quantify NEE and its components and to (2) examine the dependence of C fluxes on biophysical factors at multiple timescales. The annual budget showed a gross ecosystem productivity (GEP) of 456 g C m−2 yr−1 (with a 90% prediction interval of 449–463 g C m−2 yr−1) and an ecosystem respiration (Re) of 379 g C m−2 yr−1 (with a 90% prediction interval of 370–389 g C m−2 yr−1), resulting in a net C sink of 77 g C m−2 yr−1 (with a 90% prediction interval of 68–87 g C m−2 yr−1). The maximum daily NEE, GEP and Re were −4.7, 6.8 and 3.3 g C m−2 day−1, respectively. Both the maximum C assimilation rate (i.e., at the optimum light intensity) and the quantum yield varied over the growing season, being higher in summer and lower in spring and autumn. At the half-hourly scale, water deficit exerted a major control over daytime NEE, and interacted with other stresses (e.g., heat and photoinhibition) in constraining C fixation by the vegetation. Low soil moisture also reduced the temperature sensitivity of Re (Q10). At the synoptic scale, rain events triggered immediate pulses of C release from the ecosystem, followed by peaks of CO2 uptake 1–2 days later. Over the entire growing season, leaf area index accounted for 45 and 65% of the seasonal variation in NEE and GEP, respectively. There was a linear dependence of daily Re on GEP, with a slope of 0.34. These results highlight the role of abiotic stresses and their alleviation in regulating C cycling in the face of an increasing frequency and intensity of extreme climatic events.

This study sought to explore endothelial nitric oxide synthase (eNOS) expression in acute pulmonary thromboembolism (APE).eNOS expression in lung tissue and bone marrow-derived endothelial progenitor cells (BM-EPCs) from APE mouse models was assessed by immunohistochemistry and real-time PCR. A gene expression profile meta-analysis was performed on human venous thromboembolism (VTE) whole blood samples recorded in the Gene Expression Omnibus (GEO) repository. Significantly expressed genes were determined from the microarray data by unsupervised clustering and supervised classification. Selected sample data with significantly expressed genes were further analyzed by principal component analysis (PCA), followed by Bayesian probit regression. Key discriminate genes were further grouped and annotated using functional annotations and gene enrichments using the online Database for Annotation, Visualization and Integrated Discovery (DAVID) software (v. 6.7).While eNOS expression was significantly higher, serum nitric oxide levels were significantly lower in APE mice (20.42 ± 2.15 μM) compared to controls (53.50 ± 5.69 μM, p0.001). eNOS mRNA and protein levels were significantly upregulated in BM-EPCs from APE mice. GEO repository data reported 3,397 upregulated and 4,173 downregulated genes (including eNOS) in VTE patients. In this regression analysis, the significant principal component PC1 and PC2 (p0.05) were useful in distinguishing the VTE classification. The coefficient value of eNOS was -0.47707 in PC1 and -0.08429 in PC2, which did have some proportions on these significantly discriminated components but did not contribute significantly to the VTE classification. Functional enrichment in terms of acetylation and phosphoproteins were high.Our findings, therefore, suggest that expression of eNOS is significantly altered in APE and may be a potential peripheral blood biomarker. Modulation of eNOS expression may be used for APE treatment.

To enhance the understanding of Takayasu's arteritis with pulmonary vascular involvement through the analyses on clinical features, imaging findings, misdiagnoses and treatments.A retrospective study was conducted to analyze the clinical records of patients diagnosed as Takayasu's arteritis with pulmonary vascular involvement admitted to Beijing Chaoyang Hospital from January 2004 to December 2014.In recent 10 years, there were 90 patients diagnosed as Takayasu's arteritis in Beijing Chaoyang Hospital, 33 of them were involved with pulmonary arterial, which account for 36.7%, while 12 cases were involved with pulmonary arteries alone, which account for 13.3% of all. Among the 33 patients, dyspnea (23 cases, 69.7%) was the most common symptom, followed by hemoptysis (19 cases, 57.6%) and Vascular murmur (23 cases, 69.7%), pleural effusion (8 cases, 24.2%), unequal blood pressure of upper limbs (4 cases, 12.1%) were the main signs. The diagnostic time varied significantly, from 1 month to 10 years. 21 patients were misdiagnosed and the misdiagnosis rate was 63.6%.Takayasu's arteritis with pulmonary vascular involvement is not rare. The clinical manifestation of Takayasu's arteritis is unspecific and misdiagnosis rate is relatively high. Therefore, we should raise awareness of Takayasu's arteritis and detailed clinical examination will be helpful to reduce the misdiagnosis rate.

Soil respiration (Rs) and its biophysical controls were measured over a fixed sand dune in a desert-shrub ecosystem in northwest China in 2012 to explore the mechanisms controlling the spatial heterogeneity in Rs and to understand the plant effects on the spatial variation in Rs in different phenophases. The measurements were carried out on four slope orientations (i.e., windward, leeward, north- and south-face) and three height positions on each slope (i.e., lower, upper, and top) across the phenophases of the dominant shrub species (Artemisia ordosica). Coefficient of variation (i.e., standard deviation/mean) of Rs across the 11 microsites over our measurement period was 23.5 %. Soil respiration was highest on the leeward slope, but lowest on the windward slope. Over the measurement period, plant-related factors, rather than micro-hydrometeorological factors, affected the topographic variation in Rs. During the flowering-bearing phase, root biomass affected Rs most, explaining 72 % of the total variation. During the leaf coloration-defoliation phase, soil nitrogen content affected Rs the most, explaining 56 % of the total variation. Our findings highlight that spatial pattern in Rs was dependent on plant distribution over a desert sand dune, and plant-related factors largely regulated topographic variation in Rs, and such regulations varied with plant phenology.