This study presents development and application of a fully coupled two-phase (methane and water) and poromechanics numerical model for the analysis of geomechanical impact on coalbed methane (CBM) production. The model considers changes in two-phase fluid flow properties, i.e., coal porosity, permeability, water retention, and relative permeability curves through changes in cleat fractures induced by effective stress variations and desorptioninduced shrinkage. The coupled simulator is first verified for poromechamics coupling and simulation parameters of a CBM reservoir model are calibrated by history matching against one year of CBM production field data from Shanxi Province, China. Then, the verified simulator and calibrated CBM reservoir model are used for predicting the impact of geomechanics on production rate for twenty years of continuous CBM production. The simulation results show that desorption-induced shrinkage is the dominant process in increasing permeability in the near wellbore region. Away from the wellbore, desorptioninduced shrinkage is weaker and permeability is reduced by pressure depletion and increased effective stress. A sensitivity analysis shows that for coal with a higher sorption strain, a larger initial Young's modulus and smaller Poisson's ratio promote the enhancement of permeability as well as the production rate. Moreover, the conceptual model of the cleat system, whether dominated by vertical cleats with permeability correlated to horizontal stress or with permeability correlated to mean stress can have a significant impact on the predicted production rate. Overall, the study clearly demonstrates and confirms the critical importance of considering geomechanics for an accurate prediction of CBM production. (1) A fully coupled two-phase flow and poromechanics model for methane recovery (2) Simulation parameters are calibrated by history matching against field data (3) The geomechanics behaviors significantly affect the prediction of CBM production
ObjectiveTo determine the impact factors of latent tuberculosis infection (LTBI) and the knowledge of TB prevention and treatment policy among health care workers (HCWs) in different types of hospitals and explore the strategies for improving TB prevention and control in medical institutions in China.MethodsA cross-sectional study was carried out to evaluate the risk of TB infection and personnel occupational protection among HCWs who directly engage in medical duties in one of two public hospitals. Each potential participant completed a structured questionnaire and performed a tuberculin skin test (TST). Factors associated with LTBI were identified by logistic regression analysis.ResultsSeven hundred twelve HCWs completed questionnaires and 74.3% (n = 529) took the TST or had previous positive results. The TST-positive prevalence was 58.0% (n = 127) in the infectious disease hospital and 33.9% (n = 105) in the non-TB hospital. The duration of employment in the healthcare profession (6–10 years vs. ≤5 years [OR = 1.89; 95% CI = 1.10, 3.25] and>10 vs. ≤5[OR = 1.80; 95% CI = 1.20, 2.68]), type of hospital (OR = 2.40; 95% CI = 1.59, 3.62), and ever-employment in a HIV clinic or ward (OR = 1.87; 95% CI = 1.08, 3.26)were significantly associated with LTBI. The main reasons for an unwillingness to accept TST were previous positive TST results (70.2%) and concerns about skin reaction (31.9%).ConclusionA high prevalence of TB infections was observed among HCWs working in high-risk settings and with long professional experiences in Henan Province in China. Comprehensive guidelines should be developed for different types of medical institutions to reduce TB transmission and ensure the health of HCWs.
Objectives. This study aims to analyze the cesarean section (CS) rates and vaginal delivery rates in tertiary hospitals of China, explore the costs of two different deliveries, and examine the relative influencing factors of the costs in both CS and vaginal deliveries. Methods. 30,168 anonymized obstetric medical cases were selected from three sample tertiary hospitals in Chongqing Municipality from 2011 to 2013. Chi-square test was used to compare the distributions of CS and vaginal deliveries under different indicators. Mann–Whitney test and Kruskal-Wallis test were adopted to analyze the differences under different items. Multiple linear regression was used to determine the influencing factors of the costs of different delivery modes. Results. (1) The rates of CS were 69%, 65.5%, and 59.2% in the three sample tertiary hospitals in Chongqing from 2011 to 2013. (2) The costs and the length of stay of CS were greater than those of vaginal delivery, which had significant differences (P < 0.005). (3) The areas, length of stay, age, medical insurance, and modes of delivery were the influencing factors of both CS and vaginal delivery costs. Discussion. The high CS rates in China must be paid significant attention. The indicators of two modes of delivery should be regulated strictly. CS rate reduction and saving medical resources will be the benefits if vaginal delivery is chosen by pregnant women.
Mitochondrial quality control plays an important role in maintaining mitochondrial homeostasis and function. Disruption of mitochondrial quality control degrades brain function. We found that flunarizine (FNZ), a drug whose chronic use causes parkinsonism, led to a parkinsonism-like motor dysfunction in mice. FNZ induced mitochondrial dysfunction and decreased mitochondrial mass specifically in the brain. FNZ decreased mitochondrial content in both neurons and astrocytes, without affecting the number of nigral dopaminergic neurons. In human neural progenitor cells, FNZ also induced mitochondrial depletion. Mechanistically, independent of ATG5- or RAB9-mediated mitophagy, mitochondria were engulfed by lysosomes, followed by a vesicle-associated membrane protein 2– and syntaxin-4–dependent extracellular secretion. A genome-wide CRISPR knockout screen identified genes required for FNZ-induced mitochondrial elimination. These results reveal not only a previously unidentified lysosome-associated exocytosis process of mitochondrial quality control that may participate in the FNZ-induced parkinsonism but also a drug-based method for generating mitochondria-depleted mammal cells.
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