Seasonal Characteristics of Black Carbon Aerosol and its Potential Source Regions in Baoji, China

Continuous measurements of black carbon (BC) aerosol were made at a midsized urban site in Baoji, China, in 2015. The daily average mass concentrations varied from 0.6 to 11.5 mu g m(-3), with an annual mean value of 2.9 +/- 1.7 mu g m(-3). The monthly variation indicated that the largest loading of BC occurred in January and the smallest in June. The mass concentrations exhibited strong seasonality, with the highest occurring in winter and the lowest in summer. The large BC loadings in winter were attributed to the increased use of fuel for domestic heating and to stagnant meteorological conditions, whereas the low levels in summer were related to the increase in precipitation. BC values exhibited similar bimodal diurnal patterns during the four seasons, with peaks occurring in the morning and evening rush hours and an afternoon trough, which was associated with local anthropogenic activities and meteorological conditions. A potential source contribution function model indicated that the effects of regional transport mostly occurred in spring and winter. The most likely regional sources of BC in Baoji were southern Shaanxi province, northwestern Hubei province, and northern Chongqing during spring, whereas the northeastern Sichuan Basin was the most important source region during winter

Effect of reduced nitrogen fertilizer application combined with biochar on nitrogen utilization of flue-cured tobacco and its association with functional gene expressions of the nitrogen cycle in rhizosphere soil

Studies have shed light on the impact of the co-application of inorganic fertilizer and biochar on soil fertility, health, and crop growth performance and yield. However, insufficient literature exists regarding the appropriate nitrogen reduction ratio for enhancing soil quality and maximizing crop nitrogen utilization following the application of biochar in a continuous tobacco-rice rotation field. Here, we explored nitrogen absorption and utilization patterns of tobacco crops, as well as the response characteristics of functional genes related to soil nitrogen cycling subjected to the interaction of reduced nitrogen utilization ratios following biochar application in a long-term tobacco-rice rotation field. The results showed that the treatments with 10% (T2) and 20% (T3) nitrogen reduction combined with biochar (30 t∙ha−1) promoted nitrogen utilization efficiency and nitrogen harvest index of tobacco plants. In the second year of the experiment, T2 and T3 significantly increased the nitrogen harvest index by 3.85% and 5.78% compared with the conventional nitrogen application treatment (T1), respectively. We believe that the increase in abundance of nitrification, nitrogen fixation, and ammonification genes, including nxrA, nifH, and UreC in the rhizosphere soil, precipitate the high nitrogen absorption and utilization efficiency in the biochar combined with nitrogen reduction treatments, respectively. This suggests that biochar application at a rate of 30 t·ha−1, nitrogen fertilizer usage can be reduced by 10% and 20% to achieve optimal and sustainable tobacco production

Seasonal Distribution of Atmospheric Coarse and Fine Particulate Matter in a Medium-Sized City of Northern China

Atmospheric particulate matter (PM) was measured continuously at an urban site in Baoji city in northern China in 2018 to investigate the seasonal distribution characteristics. Coarse PM (PM2.5–10) was more prevalent in spring, substantially due to the regional transport of dust. High loadings of coarse PM were found at night compared to daytime, which could result from high production and unfavorable dispersion conditions. Fine PM (PM2.5) constituted, on average, 54% of the total PM mass concentration, whereas it contributed more than 97% of the total PM number concentration. The number and mass concentrations of fine PM increased substantially in the winter, which was possibly due to the enhanced production of atmospheric secondary processes and coal combustion. Precursor gaseous pollutants and meteorology greatly influenced the PM distributions. Fine PM was associated more strongly with gas pollutants than coarse PM, which suggested that it largely originated from secondary production and combustion sources. High relative humidity appeared to promote the production of fine PM, whereas it facilitated the removal of coarse PM. This study highlights that different air-pollution control strategies should be used for coarse and fine PM according to the distribution characteristics and influencing factors in similar medium-sized urban areas

Composition and size distribution of airborne particulate PAHs and oxygenated PAHs in two Chinese megacities

Concentrations and compositions of PAHs and oxygenated PAHs (OPAHs) in four size ranges of ambient particles (9.0 mu m) collected in Xi'an and Guangzhou, two megacities of China, during the winter and summer of 2013 were measured and compared with those in 2003. The TSP-equivalent concentrations of Sigma 14PAHs in Xi'an and Guangzhou are 57 +/- 20 and 18 +/- 23 ng m(-3) in winter, 5-10 times higher than those in summer. PAHs in both cities are dominated by 5- and 6-ring congeners in summer. In contrast, they are dominated by 4- and 5-ring congeners in winter, probably due to enhanced gas-to-particle phase partitioning of the semi-volatile PAHs. TSP-equivalent Sigma OPAHs during winter are 54 +/- 15 and 23 +/- 32 ng m(-3) in Xi'an and Guangzhou and dominated by 5-ring OPAHs

Hsp90 Regulates Activation of Interferon Regulatory Factor 3 and TBK-1 Stabilization in Sendai Virus-infected Cells

Interferon regulatory factor 3 (IRF3) plays a crucial role in mediating cellular responses to virus intrusion. The protein kinase TBK1 is a key regulator inducing phosphorylation of IRF3. The regulatory mechanisms during IRF3 activation remain poorly characterized. In the present study, we have identified by yeast two-hybrid approach a specific interaction between IRF3 and chaperone heat-shock protein of 90 kDa (Hsp90). The C-terminal truncation mutant of Hsp90 is a strong dominant-negative inhibitor of IRF3 activation. Knockdown of endogenous Hsp90 by RNA interference attenuates IRF3 activation and its target gene expressions. Alternatively, Hsp90-specific inhibitor geldanamycin (GA) dramatically reduces expression of IRF3-regulated interferon-stimulated genes and abolishes the cytoplasm-to-nucleus translocation and DNA binding activity of IRF3 in Sendai virus-infected cells. Significantly, virus-induced IRF3 phosphorylation is blocked by GA, whereas GA does not affect the protein level of IRF3. In addition, TBK1 is found to be a client protein of Hsp90 in vivo. Treatment of 293 cells with GA interferes with the interaction of TBK1 and Hsp90, resulting in TBK1 destabilization and its subsequent proteasome-mediated degradation. Besides maintaining stability of TBK1, Hsp90 also forms a novel complex with TBK1 and IRF3, which brings TBK1 and IRF3 dynamically into proximity and facilitates signal transduction from TBK1 to IRF3. Our study uncovers an essential role of Hsp90 in the virus-induced activation of IRF3

Table_2_Nursing management of treatment-related venous thromboembolism in patients with multiple myeloma.pdf

ObjectivesVenous thromboembolism (VTE) is a common complication among patients with newly diagnosed multiple myeloma (NDMM). Therefore, this study aimed to analyze the incidence and risk factors associated with VTE in the current era of thromboprophylaxis and to propose appropriate nursing measures.MethodsA total of 1,539 NDMM patients were retrospectively analyzed. All patients underwent VTE risk assessment and received aspirin or low molecular weight heparin (LMWH) to prevent thrombosis, followed by appropriate care based on their individual thrombosis risk. The incidence of VTE and its related risk factors were then analyzed.ResultsAll patients received at least four cycles of therapy containing immunomodulators (IMiDs) and/or proteasome inhibitors (PIs). We assigned 371 patients (24.1%) to the moderate-risk thrombosis group, who received daily aspirin (75 mg) for thrombosis prevention and 1,168 patients (75.9%) to the high-risk group, who received daily low molecular weight heparin (3,000 IU) for thrombosis prevention two times a day. Among all the patients, 53 (3.4%) experienced lower extremity venous thromboembolism events, with three of those patients experiencing a concurrent pulmonary embolism. A multivariate analysis indicated that bed rest lasting more than 2 months and plasma cells of ≥60% were independent factors associated with thrombosis.ConclusionMore effective risk assessment models are needed to predict thrombosis accurately. In addition, nurses involved in the treatment and management of thrombosis should continually engage in professional development to enhance their knowledge and skills.</p

Table_1_Nursing management of treatment-related venous thromboembolism in patients with multiple myeloma.pdf

ObjectivesVenous thromboembolism (VTE) is a common complication among patients with newly diagnosed multiple myeloma (NDMM). Therefore, this study aimed to analyze the incidence and risk factors associated with VTE in the current era of thromboprophylaxis and to propose appropriate nursing measures.MethodsA total of 1,539 NDMM patients were retrospectively analyzed. All patients underwent VTE risk assessment and received aspirin or low molecular weight heparin (LMWH) to prevent thrombosis, followed by appropriate care based on their individual thrombosis risk. The incidence of VTE and its related risk factors were then analyzed.ResultsAll patients received at least four cycles of therapy containing immunomodulators (IMiDs) and/or proteasome inhibitors (PIs). We assigned 371 patients (24.1%) to the moderate-risk thrombosis group, who received daily aspirin (75 mg) for thrombosis prevention and 1,168 patients (75.9%) to the high-risk group, who received daily low molecular weight heparin (3,000 IU) for thrombosis prevention two times a day. Among all the patients, 53 (3.4%) experienced lower extremity venous thromboembolism events, with three of those patients experiencing a concurrent pulmonary embolism. A multivariate analysis indicated that bed rest lasting more than 2 months and plasma cells of ≥60% were independent factors associated with thrombosis.ConclusionMore effective risk assessment models are needed to predict thrombosis accurately. In addition, nurses involved in the treatment and management of thrombosis should continually engage in professional development to enhance their knowledge and skills.</p

Reciprocal REGγ-Nrf2 Regulation Promotes Long Period ROS Scavenging in Oxidative Stress-Induced Cell Aging

Increased accumulation of reactive oxygen species (ROS) and decline of adaptive response of antioxidants to oxidative stimuli has been implicated in the aging process. Nuclear factor erythroid 2-related factor 2 (Nrf2) activation is a core event in attenuating oxidative stress-associated aging. The activity is modulated by a more complex regulatory network. In this study, we demonstrate the proteasome activator REGγ function as a new regulator of Nrf2 activity upon oxidative stress in cell aging model induced by hydrogen peroxide (H2O2). REGγ deficiency promotes cell senescence in primary MEF cells after H2O2 treatment. Accordingly, ROS scavenging is accelerated in WT cells but blunted in REGγ lacking cells during 12-hour recovery from a 1-hour H2O2 treatment, indicating long-lasting antioxidant buffering capacity of REGγ. Mechanistically, through GSK-3β inhibition, REGγ enhances the nuclear distribution and transcriptional activity of Nrf2, which is surveyed by induction of phase II enzymes including Ho1 and Nqo1. Meanwhile, Nrf2 mediates the transcriptional activation of REGγ upon H2O2 stimulation. More interestingly, short-term exposure to H2O2 leads to transiently upregulation and gradually descent of REGγ transcription, however sustained higher REGγ protein level even in the absence of H2O2 for 24 hours. Thus, our results establish a positive feedback loop between REGγ and Nrf2 and a new layer of adaptive response after oxidative stimulation that is the REGγ-GSK-3β-Nrf2 pathway