Effect of water deficit on growth and photosynthetic characteristics of 13 winter wheat

Wheat is one of the major crops in the world and is rather sensitive to water deficit and differences between genotypes for water tolerance have been previously testified. Experiment was conducted in a greenhouse with 13 cultivars grown in control and water deficit conditions. Gas exchange, chlorophyll fluorescence parameters, above ground biomass and total leaf area were measured to determine water tolerance. Drought susceptibility indexes were used to estimate the relative tolerance of wheat cultivars to water deficit. Water deficit decreased total leaf area, above-ground biomass, net photosynthesis, stomatal conductance, internal CO2 concentration and the actual quantum yield of PS II electron transport relative to cultivars that were grown under control condition. Measurement of stomatal conductance provided useful information to assess genetic differences in wheat for absolute performance when subjected to water deficit. Besides, CY20 and XN979 showed more drought tolerance than other wheat cultivars in terms of drought susceptibility indexes.Key words: Wheat cultivars, growth, chlorophyll fluorescence, gas exchange, water deficit

1α, 25-dihydroxyvitamin D3 suppresses differentiation, maturation and activation of dendritic cells from patients with systemic lupus erythematosus

BACKGROUND: Dendritic cells (DC), professional antigen presenting cells, are believed to play a crucial role in the pathogenesis of systemic lupus erythematosus (SLE). 1α, 25-dihydroxyvitamin D3 (VitD3), in addition to its effect on bone metabolism, has been increasingly recognised to have immunomodulatory effects. OBJECTIVE: To examine the effect of VitD3 on the differentiation, maturation, and activation of DCs in SLE patients. METHODS: CD14+ monocyte–derived DCs from SLE patients and age- and sex-matched controls were derived from growth medium cultured with IL-4, GM-CSF. Mature DCs were induced by addition of lipopolysaccharide and tumour necrosis factor-α in the presence or absence of VitD3 (1×10-10 M) and/or dexamethasone (1×10-6 M). The expression of CD1a, a DC marker and markers of maturation and co-stimulatory molecules such as CD80, CD86, CD40, HLA-DR and CD83 were examined by flow cytometry. After stimulation of DCs with CD40L for 24 hours, the production of pro-inflammatory cytokines including IL-12 and IL-6, were measured by ELISA kits. RESULTS: VitD3 suppresses differentiation of monocytes into DCs as showed by the decreased expression of CD1a (P<0.05). VitD3 inhibits the expression of maturation markers including CD86, CD40 and CD83 (P<0.05), but not CD80 and HLA-DR. This effect was more marked in SLE patients (n=14) than controls (n=9). In combination with dexamethasone, VitD3 displayed more potent immunosuppressive effect on DCs. Under the effect of VitD3, stimulated DCs produced less of IL-12 (3.1 vs 10.4 pg/mL, P=0.02) and IL-6 (216.0 vs 224.0 pg/mL, P=0.21) in SLE patients as well as controls (8.0 vs 36.6 μg/mL, P=0.01 for IL-12) and (380.7 vs 415.2 pg/mL, P=0.04 for IL-6). CONCLUSION: VitD3 is found to inhibit differentiation, maturation, and activation of DCs in vitro in both SLE patients and controls and may be considered as immunomodulatory agent in the treatment of SLE.published_or_final_versionThe 15th Medical Research Conference (15th MRC), Department of Medicine, University of Hong Kong, Hong Kong, 16 January 2010. In Hong Kong Medical Journal, 2010, v. 16 n. 1, suppl. 1, p. 57, abstract no. 9

Construction and Control of Genetic Regulatory Networks: A Multivariate Markov Chain Approach

In the post-genomic era, the construction and control of genetic regulatory networks using gene expression data is a hot research topic. Boolean networks (BNs) and its extension Probabilistic Boolean Networks (PBNs) have been served as an effective tool for this purpose. However, PBNs are difficult to be used in practice when the number of genes is large because of the huge computational cost. In this paper, we propose a simplified multivariate Markov model for approximating a PBN The new model can preserve the strength of PBNs, the ability to capture the inter-dependence of the genes in the network, qnd at the same time reduce the complexity of the network and therefore the computational cost. We then present an optimal control model with hard constraints for the purpose of control/intervention of a genetic regulatory network. Numerical experimental examples based on the yeast data are given to demonstrate the effectiveness of our proposed model and control policy.published_or_final_versio

Anisotropic step-flow growth and island growth of GaN(0001) by molecular beam epitaxy

GaN(0001) thin films are grown using radio frequency plasma assisted molecular beam epitaxy. By changing the growth temperature, anisotropic growth rate behavior is observed in both the step-flow growth mode and the 2D island growth mode. Tunneling scanning microscopy reveals, in the step-flow growth mode, strong influences from the growth anisotropy on the shape of the terrace edges, resulting in striking differences between hexagonal and cubic films. In the 2D nucleation growth mode, triangularly shaped islands are formed. The significance of growth anisotropy to growing high quality GaN films is discussed.published_or_final_versio

Preconditioning with Porphyromonas gingivalis lipopolysaccharide may confer cardioprotection and improve recovery of the electrically induced intracellular calcium transient during ischemia and reperfusion

Background and Objective: Porphyromonas gingivalis lipopolysaccharide (LPS) is a ligand for cell surface toll-like receptors (TLR), TLR2 and TLR4 while stimulation of either leads to cardioprotection. We hypothesized that: (1) pretreatment with P. gingivalis LPS at appropriate concentrations would induce cardioprotection against injury induced by ischemia and reperfusion; and (2) P. gingivalis LPS pretreatment at cardioprotective concentrations may reduce Ca2+ overload, which is a precipitating cause of injury, and improve recovery of contractile function. Material and Methods: Male Sprague-Dawley rats were randomly selected to receive intraperitoneal saline or hot phenol-water-extracted P. gingivalis LPS at 0.2, 0.5, 1.0, 2.0 or 4.0 mg/kg 24 h before the experiment. The hearts were isolated and subjected to regional ischemia by coronary artery ligation followed by reperfusion. In isolated rat ventricular myocytes, the cytosolic Ca2+ level and the electrically induced intracellular calcium (E[Ca2+]i) transient, which reflects contractile function, were determined after pretreatment with a cardioprotective dose of P. gingivalis LPS. Results: Pretreatment with 0.5 mg/kg P. gingivalis LPS significantly reduced, while pretreatment with 1.0-4.0 mg/kg significantly increased infarct size. The Ca2+ overload induced by ischemia-reperfusion was attenuated in myocytes from rats pretreated with 0.5 mg/kg P. gingivalis LPS. Pretreated myocytes also showed an increased amplitude of the E[Ca2+]i transient, no prolongation of the time to reach the peak E[Ca2+]i transient and shorter 50% decay time during reperfusion. Conclusion: At a dosage of 0.5 mg/kg, P. gingivalis LPS confers cardioprotection against ischemia-reperfusion-induced injury and improved intracellular E[Ca2+]i transient recovery, hence improving myocyte contractile recovery. © 2009 John Wiley & Sons A/S.postprin

Topological Homogeneity for Electron Microscopy Images

In this paper, the concept of homogeneity is defined, from a topological perspective, in order to analyze how uniform is the material composition in 2D electron microscopy images. Topological multiresolution parameters are taken into account to obtain better results than classical techniques.Ministerio de Economía y Competitividad MTM2016-81030-PMinisterio de Economía y Competitividad TEC2012-37868-C04-0

Atherosclerosis in patients with rheumatoid arthritis

Both Rheumatoid Arthritis (RA) and atherosclerosis are complex polygenic diseases. Previous studies have demonstrated that patients with RA are associated with up to 60% increased risk of cardiovascular disease related death. Nonetheless, the increased cardiovascular morbidity and mortality in patients with RA cannot be entirely explained by traditional risk factors, and likely to be multifactorial. The present article reviews the data supporting the association of RA with cardiovascular risk factors, possible mechanism for developing atherosclerosis and evaluates the potential strategies that may prevent premature atherosclerosis in these patients.published_or_final_versio

Temperature-vacuum swing adsorption for direct air capture by using low-grade heat

Direct air capture (DAC) is a promising carbon mitigation technology and will likely be part of extensive carbon removal portfolio. Adsorptive DAC is an appropriate option for carbon capture to utilize low-grade heat because of its desirable regeneration temperature and adaptability to be integrated with renewables. Building indoor environment with CO2 concentrations above 1000 ppm provides another suitable scenario for DAC. Herein, DAC using temperature-vacuum swing adsorption (TVSA) is presented and analyzed by integrating various low-grade heat sources in buildings. An amine-functionalized metal organic framework is selected for process simulation, and the performance is compared with those using other sorbents. It indicates that amine-functionalized material has advantages in CO2 productivity and purity. A techno-economic analysis is carried out to explore the benefit of the proposed DAC in buildings. The results show that regeneration by heat pumps at 373 K is the most competitive solution and has 176.7 $·tCO2−1 of the levelized cost of DAC (LCOD). Compared with conventional energy supply, solutions with low-grade heat utilization in buildings could achieve lower carbon intensity and increase by 5.2–25.0% in net LCOD. These results will provide practical guidelines for DAC application with lower energy penalties and costs

Stabilizing forces acting on ZnO polar surfaces: STM, LEED, and DFT

published_or_final_versio

Clinical significance of hepatic derangement in severe acute respiratory syndrome

Aim: Elevation of alanine aminotransferase (ALT) level is commonly seen among patients suffering from severe acute respiratory syndrome (SARS). We report the progression and clinical significance of liver derangement in a large cohort of SARS patient. Methods: Serial assay of serum ALT was followed in patients who fulfilled the WHO criteria of SARS. Those with elevated ALT were compared with those with normal liver functions for clinical outcome. Serology for hepatitis B virus (HBV) infection was checked. Adverse outcomes were defined as oxygen desaturation, need of intensive care unit (ICU) and mechanical ventilation and death. Results: Two hundred and ninety-four patients were included in this study. Seventy (24%) patients had elevated serum ALT on admission and 204 (69%) patients had elevated ALT during the subsequent course of illness. Using peak ALT >5×ULN as a cut-off and after adjusting for potential confounding factors, the odds ratio of peak ALT >5× ULN for oxygen desaturation was 3.24 (95%CI 1.23-8.59, P = 0.018), ICU care was 3.70 (95%CI 1.38-9.89, P = 0.009), mechanical ventilation was 6.64 (95%CI 2.22-19.81, P = 0.001) and death was 7.34 (95%CI 2.28-24.89, P = 0.001). Ninety-three percent of the survived patients had ALT levels normalized or were on the improving trend during follow-up. Chronic hepatitis B was not associated with worse clinical outcomes. Conclusion: Reactive hepatitis is a common complication of SARS-coronavirus infection. Those patients with severe hepatitis had worse clinical outcome. © 2005 The WJG Press and Elsevier Inc. All rights reserved.published_or_final_versio