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Abstract It is widely known that some soils have strong levels of disease suppression and prevent the establishment of pathogens in the rhizosphere of plants. However, what soils are better suppressing disease, and how management can help us to boost disease suppression remain unclear. Here, we used field, greenhouse and laboratory experiments to investigate the effect of management (monocropping and rotation) on the capacity of rhizosphere microbiomes in suppressing peanut root rot disease. Compared with crop rotations, monocropping resulted in microbial assemblies that were less effective in suppressing root rot diseases. Further, the depletion of key rhizosphere taxa in monocropping, which were at a disadvantage in the competition for limited exudates resources, reduced capacity to protect plants against pathogen invasion. However, the supplementation of depleted strains restored rhizosphere resistance to pathogen. Taken together, our findings highlight the role of native soil microbes in fighting disease and supporting plant health, and indicate the potential of using microbial inocula to regenerate the natural capacity of soil to fight disease.

Abstract Soil-borne pathogens pose a major threat to food production worldwide, particularly under global change and with growing populations. Yet, we still know very little about how the soil microbiome regulates the abundance of soil pathogens and their impact on plant health. Here we combined field surveys with experiments to investigate the relationships of soil properties and the structure and function of the soil microbiome with contrasting plant health outcomes. We find that soil acidification largely impacts bacterial communities and reduces the capacity of soils to combat fungal pathogens. In vitro assays with microbiomes from acidified soils further highlight a declined ability to suppress Fusarium, a globally important plant pathogen. Similarly, when we inoculate healthy plants with an acidified soil microbiome, we show a greatly reduced capacity to prevent pathogen invasion. Finally, metagenome sequencing of the soil microbiome and untargeted metabolomics reveals a down regulation of genes associated with the synthesis of sulfur compounds and reduction of key traits related to sulfur metabolism in acidic soils. Our findings suggest that changes in the soil microbiome and disruption of specific microbial processes induced by soil acidification can play a critical role for plant health.

By studying the dynamic characteristics of and key growth stages for mercury (Hg) enrichment in rice, the Hg migration and translocation processes in this species can be better understood. In this study, a pot experiment was conducted, wherein two rice cultivars, Tianyouhuazhan (TYHZ, indica) and Zhendao 18 (ZD18, japonica), were selected and planted for analysing the Hg accumulation kinetic characteristics in rice plants. The plants were sampled at each growth stage, and the biomass and total Hg (THg) and methylmercury (MeHg) concentrations of each tissue were measured. The relative Hg contribution rates (CRs) in whole rice plants and rice grains were calculated, and the growth stage with the highest relative contribution was identified as the key growth stage for Hg accumulation. The results indicated that in rice, the MeHg translocation capability was stronger than the THg translocation capability. Significant differences in the kinetic characteristics of Hg accumulation were found between the two rice cultivars, and the TYHZ rice grains had a stronger Hg accumulation ability than the ZD18 rice grains. The key growth stages for THg accumulation in whole rice plants of both cultivars were the tillering and booting stages, while that for MeHg accumulation was the tillering stage. The key period for Hg accumulation in rice grains was the grain filling stage for both cultivars. The insights from this study could provide scientific guidance for the safe production of rice in Hg-contaminated soil.

Background: To investigate the relationship between red blood cell (RBC) folate and congestive heart failure (CHF). Methods: We extracted the concentrations of RBC folate and collated CHF information from the National Health and Nutrition Examination Survey (NHANES) survey (12820 individuals). Weighted univariate logistic regression, weighted multivariate logistic regression, and restrictive cubic spline (RCS) were used to assess the relationship between RBC folate concentrations and CHF. Results: The unadjusted model showed that the highest tertile group of RBC folate concentration was significantly associated with a higher risk of CHF compared to the lowest tertile group of RBC folate levels (odds ratio [OR] = 3.09; 95% confidence interval [CI], 2.14–4.46). Similar trends were seen in the multivariate-adjusted analysis (OR = 1.98; 95% CI: 1.27–3.09). The OR was >1.0 when the predicted RBC folate exceeded 2757 nmol/L in the RCS model, indicating that the risk of CHF was low and relatively stable up to a predicted RBC folate level of 2757 nmol/L, but began to increase rapidly thereafter (p = 0.001). Conclusions: The risk of CHF may be increased either by high RBC folate concentrations (highest tertile of RBC folate or >2637 nmol/L) or by folate deficiency. Considering the two sides of the association between RBC folate and CHF, there is a need for large-scale clinical research to better investigate if the association between RBC folate and CHF is a cause-effect relationship, what are the underlying pathophysiological basis, as well as to identify optimal dietary folate equivalent (DFE) and RBC folate concentration intervals.

Abstract Background Atrial fibrillation (AF) is one of the most prevalent sustained cardiac arrhythmias. The latest studies have revealed a tight correlation between nonalcoholic fatty liver disease (NAFLD) and AF. However, the exact molecular mechanisms underlying the association between NAFLD and AF remain unclear. The current research aimed to expound the genes and signaling pathways that are related to the mechanisms underlying the association between these two diseases. Materials and methods NAFLD- and AF- related differentially expressed genes (DEGs) were identified via bioinformatic analysis of the Gene Expression Omnibus (GEO) datasets GSE63067 and GSE79768, respectively. Further enrichment analysis of Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG), the construction of a protein–protein interaction (PPI) network, the identification of significant hub genes, and receiver operator characteristic curve analysis were conducted. The gene-disease interactions were analyzed using the Comparative Toxicogenomics Database. In addition, the hub genes were validated by quantitative Real-Time PCR (qRT-PCR) in NAFLD cell model. Results A total of 45 co-expressed differentially expressed genes (co-DEGs) were identified between the NAFLD/AF and healthy control individuals. GO and KEGG pathway analyses revealed that the co-DEGs were mostly enriched in neutrophil activation involved in the immune response and cytokine-cytokine receptor interactions. Moreover, eight hub genes were selected owing to their high degree of connectivity and upregulation in both the NAFLD and AF datasets. These genes included CCR2, PTPRC, CXCR2, MNDA, S100A9, NCF2, S100A12, and S100A8. Conclusions In summary, we conducted the gene differential expression analysis, functional enrichment analysis, and PPI analysis of DEGs in AF and NAFLD, which provides novel insights into the identification of potential biomarkers and valuable therapeutic leads for AF and NAFLD.

In developing countries, like Pakistan, the pursuit of urbanization and economic development disrupts the delicate ecosystem, resulting in additional biogeochemical emissions of heavy metals into the human habitat and posing significant health risks. The levels of these trace elements in humans remain unknown in areas at higher risk of pollution in Pakistan. In this investigation, selected trace metals including Copper (Cu), Chromium (Cr), Lead (Pb) Cadmium (Cd), Cobalt (Co), Nickel (Ni), and Arsenic (As) were examined in human hair, urine, and nail samples of different age groups from three major cities (Muzaffargarh, Multan, and Vehari) in Punjab province, Pakistan. The results revealed that the mean concentrations (ppm) of Cr (1.1) and Cu (9.1) in hair was highest in Muzaffargarh. In urine samples, the mean concentrations (μg/L) of Co (93), As (79), Cu (69), Cr (56), Ni (49), Cd (45), and Pb (35) were highest in the Multan region, while As (34) and Cr (26) were highest in Vehari. The mean concentrations (ppm) of Ni (9.2), Cr (5.6), and Pb (2.8), in nail samples were highest in Vehari; however, Multan had the highest Cu (28) concentration (ppm). In urine samples, the concentrations of all the studied metals were within permissible limits except for As (34 µg/L) and Cr (26 µg/L) in Vehari. However, in nail samples, the concentrations of Ni in Multan (8.1 ppm), Muzaffargarh (9 ppm), Vehari (9.2 ppm), and Cd (3.69 ppm) in Muzaffargarh exceeded permissible limits. Overall, the concentrations of metals in urine, nail, and hair samples were higher in adults (39–45 age group). Cr, Cu, and Ni revealed significantly higher concentrations of metals in hair and water in Multan, whereas As in water was significantly (p < 0.001) correlated with urinary As in Multan, indicating that the exposure source was region-specific.

Soil co-contamination with cadmium (Cd) and arsenic (As) occurs frequently and has caused increasing concern. This study aimed to explore the transfer characteristics and the chemical forms, subcellular distribution of Cd and As, as well as the synthesis of phytochelatins (PCs) and other chelates in peanut (Arachis hypogaea L.) plants grown in a Cd and As co-contaminated soil, shedding light on the mechanisms involved. Compared with the single Cd contamination, Cd–As co-contamination led to a higher accumulation of Cd in peanut plants. Conversely, compared to the single As contamination, the As content increased in peanut shoots but decreased in roots and grains under Cd–As co-contamination. Furthermore, the Cd–As interaction resulted in notable changes in peanut plants’ physiological and biochemical responses. In the roots and shoots, there was an 81.8% and 60.0% increase in water-soluble Cd. In the roots, metallothioneins (MTs) content increased by 50%, while PCs increased by 6.4% in the shoots. These changes promoted the translocation of Cd from roots to grains. The Cd–As interaction also influenced the synthesis of MTs in the roots, showing a 41.2% increase, and facilitated the transfer of As to the shoots. In peanut shoots, Cd increased the cell wall fraction of As by 34.5%, decreased the proportion of water-soluble As by 31.8%, and increased PCs content by 6.9%. These changes inhibited the migration of As from shoots to grains. Overall, Cd–As co-contamination increased Cd in peanut grains by increasing water-soluble forms and MTs in roots, while Cd–As co-contamination decreased As in peanut grains by increasing cell wall fractions and PCs in shoots. These findings provide a theoretical basis for understanding Cd–As interactions in soil–peanut systems.

Abstract Background Obesity has been widely reported to be associated with the disease progression of coronavirus disease 2019 (COVID-19); however, some studies have reported different findings. We conducted a systematic review and meta-analysis to investigate the association between obesity and poor outcomes in patients with COVID-19 pneumonia. Methods A systematic review and meta-analysis of studies from the PubMed, Embase, and Web of Science databases from 1 November 2019 to 24 May 2020 was performed. Study quality was assessed, and data extraction was conducted. The meta-analysis was carried out using fixed-effects and random-effects models to calculate odds ratios (ORs) of several poor outcomes in obese and non-obese COVID-19 patients. Results Twenty-two studies (n = 12,591 patients) were included. Pooled analysis demonstrated that body mass index (BMI) was higher in severe/critical COVID-19 patients than in mild COVID-19 patients (MD 2.48 kg/m2, 95% CI [2.00 to 2.96 kg/m2]). Additionally, obesity in COVID-19 patients was associated with poor outcomes (OR = 1.683, 95% CI [1.408–2.011]), which comprised severe COVID-19, ICU care, invasive mechanical ventilation use, and disease progression (OR = 4.17, 95% CI [2.32–7.48]; OR = 1.57, 95% CI [1.18–2.09]; OR = 2.13, 95% CI [1.10–4.14]; OR = 1.41, 95% CI [1.26–1.58], respectively). Obesity as a risk factor was greater in younger patients (OR 3.30 vs. 1.72). However, obesity did not increase the risk of hospital mortality (OR = 0.89, 95% CI [0.32–2.51]). Conclusions As a result of a potentially critical role of obesity in determining the severity of COVID-19, it is important to collect anthropometric information for COVID-19 patients, especially the younger group. However, obesity may not be associated with hospital mortality, and efforts to understand the impact of obesity on the mortality of COVID-19 patients should be a research priority in the future.

Biochar is a stable carbon rich by-product synthesized through pyrolysis of plant and animal based biomass, and nano-biochar material has gained increasing attention due to its unique properties for environmental applications. In the present study, a simple cost-effective method for the synthesis of biochar nanoparticles through hydrothermally using agricultural residuals and by-products was developed. Both soybean straw and cattle manure were selected as the feedstock to produce the bulk-biochar. The synthesis procedure involved the digestion of the bulk-biochar with concentrated nitric acid and sulfuric acid in a high pressure condition using a hydrothermal reactor. The suspension was isolated using vacuum filtration with 0.22-μm membrane followed by drying at 65 °C in an oven. Scanning electron microscopy results revealed that both of the biochars had a well-developed porous structure following pyrolysis. Both transmission electron microscopy and the dynamic light scattering results of the hydrothermally treated biochar indicated that the soybean straw and cattle manure biochar nanodots had an average of 5-nm and 4-nm in size, respectively. Overall two raw materials produced 8.5–10% biochar nanodots. The present method presents a simple, quick and cost-effective method for synthesis of biochar nanodots. The method provided a useful tool discovering the applicability biochar nanodots for environmental applications.• Nano-biochar formation from bulk-biochar using hydrothermal reactor• Evaluate nano-biochar's environmental fate and behavior in soil and water• Synthesize multifunctional adsorbent using nano-biochar as primary material

A 61-year-old Chinese man presented with a nearly 30-year history of an anomalous origin of the left coronary artery. He had been diagnosed with an anomalous origin of the left coronary artery in 1989. He then underwent regular echocardiographic examinations and it was found that his heart was gradually enlarging. After a >20-year asymptomatic period, he developed recurrent chest discomfort and palpitation. Coronary computed tomography angiography suggested that the left coronary artery anomaly originated from the pulmonary artery; additionally, the right coronary artery was tortuous and thickened. Coronary angiography showed that the right coronary artery was huge and buckling. The patient underwent corrective surgery of the anomalous origin of the left coronary artery from the pulmonary artery, aortic valve mechanical valve replacement, mitral valve plasty, and tricuspid valve plasty in Fuwai Hospital (National Center of Cardiovascular Disease of China), and the anatomic results of the surgery were good.

A 54-year-old Chinese woman presented with a 10-year history of repeated paroxysmal palpitations. She was diagnosed with paroxysmal supraventricular tachycardia by 12-lead electrocardiogram and was advised to undergo catheter-based radiofrequency ablation. During the procedure, a rare complication occurred that was diagnosed as a right internal mammary artery penetrating injury. After appropriate emergency treatment with arterial embolization and membrane-covered stent implantation, the patient was out of immediate danger of haemorrhaging. Follow-up computed tomography angiography of the subclavian artery at 3 months after she was discharged from hospital revealed stent-graft patency with no evidence of in-stent thrombosis or stent stenosis. No problems were observed at the 6-month follow-up visit.

Background/Aims: Transplantation of endothelial progenitor cells (EPCs) plays a therapeutic role in pulmonary arterial hypertension (PAH). Meanwhile, recruitment of progenitors has potential inflammatory effects and exaggerates vascular injury. CD40 pathway is identified as a major player in vascular inflammatory events. In this study, we investigated the role of CD40 pathway in regulating early outgrowth EPC functions, and searched for improvements in PAH cell therapy. Methods: EPCs were isolated from rat bone marrow and cultured for 7 days. After treatment with soluble CD40 ligand (sCD40L) for 24 hours, EPC migration, adhesion, proliferation, paracrine and vasculogenesis functions were tested. Rat PAH model was founded by subcutaneous injection of monocrotaline (MCT). Control EPCs or lentivirus vectors (Lv)-shRNA-CD40 EPCs were infused via tail vein at day 7, 14, and 21 after MCT injection. Therapeutic effects were evaluated at day 28. Results: sCD40L dose-dependently impaired EPC migration, adhesion, proliferation, and vasculogenesis functions. However, paracrine effects of soluble intercellular adhesion molecule-1, vascular endothelial growth factor and interleukin-6 were dose-dependently improved by sCD40L. Control EPC-derived conditioned medium protected endothelial cell in vitro vasculogenesis, while sCD40L-pretreated ones showed detrimental effects. After MCT injection, sCD40L levels in rat serum increased gradually. Other than in vitro results, benefits of both two EPC treatments were obvious, even taken at day 21. Benefits of control EPCs wore off over time, but those of Lv-shRNA-CD40 EPCs were more effective and enduring, as characterized by both ameliorated rat hemodynamic and reversed vascular remodeling. Furthermore, Lv-shRNA-CD40 EPCs integrated into endothelium better, rather than into adventitia and media. Conclusion: sCD40L impaired protective effects of EPCs. Traditional EPC treatments were limited in PAH, while interruption of CD40 pathway of transplanted cells could apparently improve the therapeutic efficacy.

The effects of soil rare earth element (REE) on navel orange quality and safety in rare earth ore areas have gained great attention. This study investigated the transfer characteristics of REE from soil to navel orange pulp (Citrus sinensis Osbeck cv. Newhall) and examined the effects of soil REE on internal fruit quality in Xinfeng County, Jiangxi province, China. Path analysis showed that soil REE, pH, cation exchange capacity (CEC), and Fe oxide (Feox) significantly affected pulp REE concentrations. A Freundlich-type prediction model for pulp REE was established: log[REEpulp] = -1.036 + 0.272 log[REEsoil] - 0.056 pH - 0.360 log[CEC] + 0.370 log[Feox] (n = 114, R2 = 0.60). From the prediction model, it was inferred that even when soil REE and Feox were as high as 1038 mg kg-1 and 96.4 g kg-1, respectively, and pH and CEC were as low as 3.75 and 5.08 cmol kg-1, respectively, pulp REE concentrations were much lower than the food limit standard. Additionally, soil REE levels were significantly correlated with selected fruit quality indicators, including titratable acidity (r = 0.52, P < 0.01), total soluble solids (r = 0.48, P < 0.01) and vitamin C (r = 0.56, P < 0.01). Generally, under routine methods of water and fertilization management, the cultivation of navel oranges in rare earth ore areas of south China with soil REE ranging from 38.6 to 546 mg kg-1 had improved in internal fruit quality.

The differences in rhizosphere nitrification activities between high- and low- fertility soils appear to be related to differences in dissolved oxygen concentrations in the soil, implying a relationship to differences in the radial oxygen loss (ROL) of rice roots in these soils. A miniaturised Clark-type oxygen microelectrode system was used to determine rice root ROL and the rhizosphere oxygen profile, and rhizosphere nitrification activity was studied using a short-term nitrification activity assay. Rice planting significantly altered the oxygen cycling in the water-soil system due to rice root ROL. Although the oxygen content in control high-fertility soil (without rice plants) was lower than that in control low-fertility soil, high rice root ROL significantly improved the rhizosphere oxygen concentration in the high-fertility soil. High soil fertility improved the rice root growth and root porosity as well as rice root ROL, resulting in enhanced rhizosphere nitrification. High fertility also increased the content of nitrification-induced nitrate in the rhizosphere, resulting in enhanced ammonium uptake and assimilation in the rice. Although high ammonium pools in the high-fertility soil increased rhizosphere nitrification, rice root ROL might also contribute to rhizosphere nitrification improvement. This study provides new insights into the reasons that an increase in soil fertility may enhance the growth of rice. Our results suggest that an amendment of the fertiliser used in nutrient- and nitrification-poor paddy soils in the red soil regions of China may significantly promote rice growth and rice N nutrition.

Soil environmental quality standards in respect of heavy metals for farmlands should be established considering both their effects on crop yield and their accumulation in the edible part. A greenhouse experiment was conducted to investigate the effects of chromium (Cr) on biomass production and Cr accumulation in carrot plants grown in a wide range of soils. The results revealed that carrot yield significantly decreased in 18 of the total 20 soils with Cr addition being the soil environmental quality standard of China. The Cr content of carrot grown in the five soils with pH>8.0 exceeded the maximum allowable level (0.5 mg kg−1) according to the Chinese General Standard for Contaminants in Foods. The relationship between carrot Cr concentration and soil pH could be well fitted (R 2 = 0.70, P <0.0001) by a linear–linear segmented regression model. The addition of Cr to soil influenced carrot yield firstly rather than the food quality. The major soil factors controlling Cr phytotoxicity and the prediction models were further identified and developed using path analysis and stepwise multiple linear regression analysis. Soil Cr thresholds for phytotoxicity meanwhile ensuring food safety were then derived on the condition of 10 percent yield reduction. [ABSTRACT FROM AUTHOR]

The role of ferrous iron in the phosphorus cycle of an aquatic ecosystem is poorly understood because of a lack of suitable methods to quantitatively evaluate ferrous iron phosphorus (FIP) phases. Using sediments sampled from Fubao Bay of Dianchi Lake in China, a novel extraction method for FIP using 2,2′-bipyridine was explored. Total phosphorus and iron in the sediments ranged from 1.0 to 5.0 mg/g (dry weight) and 28.5 to 90.6 mg/g, respectively. Organic content (as indicated by loss on ignition or LOI) and iron(II) ranged from 3.1 to 27.0% and 26.5 to 64.9 mg/g, respectively. The dissolution dynamics of FIP extraction with a low solid/liquid ratio (1:25) indicated that a single application of 0.2% 2,2′-bipyridine extracted both iron(II) (Fe(II)) and phosphorus (as P043-) in sediments with different organic contents with low efficiency. The extraction efficiency of Fe(II) was improved by alteration of the solid/liquid ratio, but the effect was limited. However, addition of a 1:1000 solid/liquid ratio of 0.5 M potassium chloride to a 0.2% 2,2′-bipyridine solution significantly accelerated extraction of FIP with the release of Fe(II) and phosphorus toward equilibrium at approximately 150 hours. Further investigation demonstrated that 2,2′-bipyridine exhibited a higher selectivity in distinguishing FIP from phosphorus bound to ferric (Fe(III)) oxides or precipitated by calcium (Ca2+). Air-drying sediments significantly decreased the amount of extracted FIP, which indicates that fresh, wet sediment should be used in this type of FIP extraction. Based on experimental results using the proposed extraction protocol, (1) FIP in sediments of Fubao Bay had a predominant status in the lake sediment and accounted for 23.4 to 39.8% of total phosphorus, and (2) Fe(II)FIP released in the extraction is directly proportional to phosphorusF,P (Fe(II)FIP = 2.84 X PFIP + 0.0007; R² = 0.97) with an average molar ratio of Fe(II)FIP/PFIP of 2.7. This study shows that FIP extraction with 2,2′-bipyridine is a robust method for releasing ferrous iron associated with phosphorus. Further, the high percentage of FIP in total phosphorus (40%) measured in the study site using this extraction method suggests that FIP might have been often underestimated in previous studies. Water Environ. Res., 84 2037 (2012). [ABSTRACT FROM AUTHOR]

Pulmonary arterial hypertension (PAH) is a fatal disease characterized by a progressive increase in pulmonary vascular resistance and vascular remodeling leading to right heart failure and early death. The pathology of PAH is associated with endothelium dysfunction and vascular remodeling in pulmonary arteries. In diseased pulmonary arteries, the balance between matrix metalloproteinases (MMP) and tissue inhibitors of metalloproteinases (TIMP) is broken down. In this process, TIMP are up-regulated, which inhibits MMP, promotes extracellular matrix (ECM) deposition and finally leads to vascular remodeling. So, what would happen to PAH if the expression of TIMP was down-regulated in diseased pulmonary vessels? We hypothesize that the attenuation of TIMP at the advanced stage of PAH might reverse severe PAH, via ameliorating vascular remodeling and endothelium repair. [ABSTRACT FROM AUTHOR]

Summary: Background: Endothelial dysfunction plays a central and critical role in the initiation and development of idiopathic pulmonary arterial hypertension (IPAH), and a variety of evidence suggests that endothelial progenitor cells (EPCs) constitute one aspect of endothelium repair. In addition, transplantation of EPCs could attenuate pulmonary hypertension induced by monocrotaline in rats. However, it has not been examined and reported whether circulating EPCs from patients with IPAH are damaged. Methods: EPCs were isolated and cultured from patients with IPAH (n=20) and matched healthy volunteers (n=20). Circulating EPC numbers (enumerated as AC133+KDR+ cells) as well as migratory and adhesive activity were assessed. Blood levels of vascular endothelial growth factor (VEGF), homocysteine (Hcy), B-type natriuretic peptide (BNP), von Willebrand Factor (vWF) and interleukin-6 (IL-6) were also measured. Results: A significant decrease was observed in circulating EPC (AC133+KDR+ cells, 86.6±20.7cells/ml blood vs. 119.6±25.4cells/ml blood, P<0.001) numbers and the cell numbers expanded in vitro (47.2±14.5 vs. 70.7±15.2EPCs/×200 field; P<0.001) in patients with IPAH. EPCs from patients with IPAH were significantly impaired in their migratory capacity and ability to adhere to fibronectin. Blood levels of VEGF, Hcy, BNP, vWF and IL-6 were elevated in patients with IPAH. EPC numbers and activity were inversely related to Hcy, IL-6, BNP and vWF. Conclusions: Our observations indicated that EPC numbers and functional capacity were impaired in patients with IPAH, which might not only give potential insight into the pathophysiological mechanisms but also might be useful for identifying suitable therapeutic targets in these patients. [Copyright &y& Elsevier]

Abstract  The effect of rainfall and nitrogen (N) input on nitrate leaching in a rain-fed peanut–oilseed rape system on an acidic soil in subtropical China was investigated in a field lysimeter experiment from 1997 to 2000. Drainage and nitrate leaching were simulated using the Water and Nitrogen Management Model (WNMM). Nitrate concentrations in the drainage water and nitrate leaching increased with increasing N application rate. Annual leaching losses ranged from 21.1 to 46.3 kg N ha−1 (9.5–16.8%) for inputs between 0 and 150 kg N ha−1. Growth of oilseed rape decreased the nitrate concentration in the drainage water, but growing N fixing peanuts did not. Rainfall had a greater impact on nitrate leaching than crop uptake. Nitrate concentrations in the drainage water were relatively low (1.95–4.33 mg N l−1); this was caused by the high precipitation, the low nitrification rate, and the low residual nitrate in the soil. The loss of nitrate was low during the dry season (October–February) and in the dry year (rainfall 17% below average) mainly as a result of reduced drainage. WNMM satisfactorily simulated the inter-monthly variation in drainage and total nitrate leached, with respective relative root mean square errors of 42.7% and 70.2%, mean modelling efficiencies of 0.88 and 0.67, and mean relative errors of −3.82% and 21.8%. The modelled annual N losses were only 1–7% less than the observed values. [ABSTRACT FROM AUTHOR]

Background: Hyperhomocysteinemia (HHcy) contributes to atherosclerosis and coronary artery diseases by inducing endothelial cell injury and dysfunction. Recent studies provided increasing evidence that endothelial progenitor cells (EPCs) participated in ongoing endothelial repair. The changes of EPCs in patients with HHcy have not yet been elucidated. Therefore, we investigated the number and functional activity of EPCs in patients with HHcy. Methods: Human EPCs were isolated and cultured from patients with HHcy (n = 30) and matched volunteers (n = 30). Circulating EPCs were enumerated as AC133+KDR+ cells via fluorescence-activated cell sorter analysis. Additionally, EPC were expanded from human blood in vitro and identified by DiI-acLDL uptake and lectin staining by direct fluorescent staining under a laser scanning confocal microscope. EPC migration activities were determined by modified Boyden chamber assay. EPC adhesion assay was performed by replating cells on fibronectin-coated dishes and then counting adherent cells. Results: A significant decrease was observed in circulating EPC (AC133+KDR+ cells) numbers in patients with HHcy compared with control subjects (63.9 ± 11.7 cells/mL vs. 91.5 ± 14.2 cells/mL blood, p <0.01). In addition, the numbers of EPCs also decreased in patients with HHcy after ex vivo cultivation (36.1 ± 6.5 vs. 51.5 ± 8.3 EPCs/×200 field, p <0.01). Both circulating EPCs and differentiated EPCs were inversely correlated with total homocysteine levels. In addition, EPCs from patients with HHcy were significantly impaired in their migratory capacity and ability to adhere to fibronectin compared with controls. Conclusions: The present study demonstrated that EPC numbers and functional capacity were impaired in patients with HHcy. [Copyright &y& Elsevier]

Recently, some studies have shown that nicotine increased neovascularization, which involves endothelial progenitor cells (EPCs). The effects of nicotine on EPCs are still unclear at present. Therefore, the authors investigated whether nicotine had influences on EPC number and activity. The EPCs were stimulated with nicotine (to make a series of final concentrations: 10 - 12 mol/L, 10 - 10 mol/L, 10 - 8 mol/L, 10 - 6 mol/L, 10 - 4 mol/L) or vehicle control for the respective time points(12, 18, 24, 32, and 48 hours). The EPCswere characterized as adherent cells double positive for DiLDL uptake and lectin binding by direct fluorescent staining under a laserscanning confocal microscope. They were further documented by demonstrating the expression of KDR, VEGFR-2, and AC133 with flow cytometry. The EPC proliferation, migration, and in vitro vasculogenesis activity were assayed with the 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay; the modified Boyden chamber assay; andthe in vitro vasculogenesis kit, respectively. The EPC adhesion assay was performed by replating those on fibronectin-coated dishes and then counting the adherent cells. As a result, nicotine dose dependently increased the EPC number and the proliferative, migratory, adhesive, and in vitro vasculogenesis capacity at nicotine concentrations of 10 - 12 to 10 - 8 mol/L. The peak effects on EPCs were observed at concentrations of nicotine 10 - 8 mol/L, similar to those in the blood of smokers. In addition, nicotine (10 - 8 mol/L) time dependently increased the EPC number and activity. However, cytotoxicity was seen at higher nicotine concentrations (> 10 - 6 mol/L). In conclusion, nicotine had complex effects on EPCs: nicotine might induce the augmentation of EPCs with enhanced functional activity at relatively low concentrations. However, cytotoxicity was seen at higher nicotine concentrations. [ABSTRACT FROM AUTHOR]

In this paper a class of conformally flat interior solutions of Einstein-Maxwell equations for a charged sphere is obtained. These solutions satisfy physical conditions inside the sphere. [ABSTRACT FROM AUTHOR]

Background aims. Tissue inhibitor of metalloproteinases-1 (TIMP-1) plays an important role in the development of pulmonary arterial hypertension. However, the molecular regulatory mechanisms of TIMP-1 in the pulmonary arteries are not fully understood, especially in human pulmonary arterial smooth muscle cells (HPASMCs). We investigated the signaling pathway involved in the regulation of TIMP-1 in HPASMCs induced by transforming growth factor (TGF)-β1. Methods. Cultured HPASMCs were incubated with different concentrations of TGF-β1 (0-40 ng/mL) for 24 h or with 10 ng/mL TGF-β1 for different times (1-48 h). Results. Western blot, real-time polymerase chain reaction and enzyme-linked immunosorbent assay analyses showed that TGF-β1 enhanced the expression and secretion of TIMP-1 in a time-dependent and dose-dependent fashion. TGF-β1 could phosphorylate two of the three mitogen-activated protein kinases-extracellular signal-regulated kinase 1/2 (ERK1/2) and p38, but not c-Jun NH2-terminal kinase. Of these kinases, only the inhibition of ERK1/2 by U0126, which was a specific inhibitor of mitogen-activated protein kinase/ERKl/2, effectively blocked the TGF-β1-induced expression of TIMP-1. Mithramycin, an inhibitor of Spl transcription factor, also significantly inhibited the expression of TIMP-1. Additionally, electrophoretic mobility shift assay showed that TGF-β1 could up-regulate the DNA-binding activity of Spl and that U0126 and mithramycin could effectively inhibit these events. Conclusions. TGF-β1 could stimulate the expression and secretion of TIMP-1 in HPASMCs in a time-dependent and dose-dependent fashion, and ERK1/2 and Spl signaling pathways might be involved in these activities. [ABSTRACT FROM AUTHOR]

Epidemiologic data suggested that there was an obvious predominance of young adult patients with a slight female proneness in severe acute respiratory syndrome (SARS). The angiotensin-converting enzyme 2 (ACE2) was very recently identified as a functional receptor for SARS virus and is therefore a prime target for pathogenesis and pharmacological intervention. Rats of both genders at three distinct ages (young-adult, 3 months; middle-aged, 12 months; old, 24 months) were evaluated to determine the characteristic of ACE2 expression in lung and the effect of aging and gender on its expression. ACE2 was predominantly expressed in alveolar epithelium, bronchiolar epithelium, endothelium and smooth muscle cells of pulmonary vessels with similar content, whereas no obvious signal was detected in the bronchiolar smooth muscle cells. ACE2 expression is dramatically reduced with aging in both genders: young-adult vs. old P < 0.001 (by 78% in male and 67% in female, respectively) and middle-aged vs. old P < 0.001 (by 71% in male rats and 59% in female rats, respectively). The decrease of ACE2 content was relatively slight between young-adult and middle-aged groups (by 25% in male and 18% in female, respectively). Although there was no gender-related difference of ACE2 in young-adult and middle-aged groups, a significantly higher ACE2 content was detected in old female rats than male. In conclusion, the more elevated ACE2 in young adults as compared to aged groups may contribute to the predominance in SARS attacks in this age group.