398 research outputs found
THE INFLUENCE OF TRANSITION METALS ON THE PERFORMANCE OF Pt Rh Pd/γ-AL2O3 THREE WAY CATALYSTS FOR PURIFICATION OF AUTOMOTIVE EXHAUST GAS
The influences of transition metal oxides (Zr, Mn, Co, Cu, Mo) on the performance of Pt Rh Pd/γ-Al2O3 three way catalysts were studied. The characteristics of the catalysts are investigated by using XRD, TPD, TPR. Experimental results show that the addition of Zr, Mn, Co, and Cu promoters improved the activity of Pt Rh Pd/γ-Al2O3 catalyst remarkably for CO, CH and NOx conversion, respectively. The effective order of the promoters is CuO > ZrO2 > Co3O4 > MnO2. The addition of CuO improved the dispersion of the noble metal on the γ-Al2O3 support and increased the absorption of Pt Rh Pd/γ-Al2O3 catalyst for CO and O2, in addition, promoted the reduction of the noble metal.
KEY WORDS: Purification of exhaust gas, Pt Rh Pd/γ-Al2O3 catalyst, Transition metals
Bull. Chem. Soc. Ethiop. 2006, 20(1), 113-120
Biochemical Components Associated With Microbial Community Shift During the Pile-Fermentation of Primary Dark Tea
Primary dark tea is used as raw material for compressed dark tea, such as Fu brick tea, Hei brick tea, Hua brick tea, and Qianliang tea. Pile-fermentation is the key process for the formation of the characteristic properties of primary dark tea, during which the microorganism plays an important role. In this study, the changes of major chemical compounds, enzyme activities, microbial diversity, and their correlations were explored during the pile-fermentation process. Our chemical and enzymatic analysis showed that the contents of the major compounds were decreased, while the activities of polyphenol oxidase, cellulase, and pectinase were increased during this process, except peroxidase activity that could not be generated from microbial communities in primary dark tea. The genera Cyberlindnera, Aspergillus, Uwebraunia, and Unclassified Pleosporales of fungus and Klebsiella, Lactobacillus of bacteria were predominant in the early stage of the process, but only Cyberlindnera and Klebsiella were still dominated in the late stage and maintained a relatively constant until the end of the process. The amino acid was identified as the important abiotic factor in shaping the microbial community structure of primary dark tea ecosystem. Network analysis revealed that the microbial taxa were grouped into five modules and seven keystone taxa were identified. Most of the dominant genera were mainly distributed into module III, which indicated that this module was important for the pile-fermentation process of primary dark tea. In addition, bidirectional orthogonal partial least squares (O2PLS) analysis revealed that the fungi made more contributions to the formation of the characteristic properties of primary dark tea than bacteria during the pile-fermentation process. Furthermore, 10 microbial genera including Cyberlindnera, Aspergillus, Eurotium, Uwebraunia, Debaryomyces, Lophiostoma, Peltaster, Klebsiella, Aurantimonas, and Methylobacterium were identified as core functional genera for the pile-fermentation of primary dark tea. This study provides useful information for improving our understanding on the formation mechanism of the characteristic properties of primary dark tea during the pile-fermentation process
Monocyte at diagnosis as a prognosis biomarker in tuberculosis patients with anemia
BackgroundAnemia leads to a lower cure rate and poor prognosis in tuberculosis patients. Effective predictors for the prognosis of tuberculosis with anemia (A-TB) are urgently needed. Monocyte has been proven to be a prognostic biomarker of many lung diseases. Whether monocyte that the predominant innate immune cell as early defense against tuberculosis can predict A-TB is not known.MethodsData for A-TB patients with initial treatment in Shanghai Pulmonary Hospital were retrospectively collected and analyzed. Logistics regression analysis was used to study the correlation between peripheral blood cells and treatment outcomes. The receiver operating characteristic (ROC) curve was used to determine the cut-off value. We estimated a 12-month prognosis using Kaplan–Meier techniques. The Cox proportional hazards model was used for the univariate and multivariate analyses to analyze the predictors of poor prognosis of A-TB.ResultsOf 181 patients analyzed, 94 were cured and 87 non-cured. Logistic regression analysis identified monocyte as an independent immune-related risk factor for the prognosis of A-TB (OR: 7.881, 95% CI: 1.675–37.075, P = 0.009). The ROC curve analysis proved that the most discriminative cut-off value of monocyte was 0.535 × 10^9/L. K–M analysis demonstrated that the cumulative cure rates of A-TB were significantly higher in A-TB with monocyte < 0.535 × 10^9/L (69.62%) than that in those with monocyte ≥ 0.535 × 10^9/L (38.24%) (Log-rank, χ2 = 16.530, P < 0.0001). On univariate and multivariable analysis, monocyte was an independent predictor of poor prognosis in A-TB. Similarly, monocyte was also an independent predictor of poor pulmonary cavity closure in A-TB (HR: 3.614, 95% CI: 1.335–9.787, P = 0.011).ConclusionIn A-TB patients, elevated monocyte was associated with poor prognosis and poor cavity pulmonary closure. Monocyte may provide a simple and inexpensive prognostic biomarker in A-TB
Observations of rapidly growing whistler waves in front of space plasma shock
Whistler mode wave is a fundamental perturbation of electromagnetic fields and plasmas in various environments including planetary space, laboratory and astrophysics. The origin and evolution of the waves are a long-standing question due to the limited instrumental capability in resolving highly variable plasma and electromagnetic fields. Here, we analyse data with the high time resolution from the multi-scale magnetospheric spacecraft in the weak magnetic environment (i.e., foreshock) enabling a relatively long gyro-period of whistler mode wave. Moreover, we develop a novel approach to separate the three-dimensional fluctuating electron velocity distributions from their background, and have successfully captured the coherent resonance between electrons and electromagnetic fields at high frequency, providing the resultant growth rate of unstable whistler waves. Regarding the energy origin for the waves, the ion distributions are found to also play crucial roles in determining the eigenmode disturbances of fields and electrons. The quantification of wave growth rate can significantly advance the understandings of the wave evolution and the energy conversion with particles
Does the integration of agriculture and tourism promote agricultural green total factor productivity?—Province-level evidence from China
The integrated development of agriculture and tourism is conducive to the realization of agricultural ecological value, which will promote the green development of agriculture and improve the green total factor productivity of agriculture as well. Based on panel data in China from 2008 to 2019, the super-efficiency SBM method and the coupling coordination degree model were used to estimate the agricultural green total factor productivity (AGTFP) and the integration level of agriculture and tourism (ATL). The dynamic spatial Durbin model and threshold effect model were used to demonstrate the effects and characteristics of the agriculture and tourism integration on AGTFP. Results showed that: 1) During the study period, AGTFP and ATL increased steadily, and showed obvious spatial agglomeration characteristics; 2) The integration of agriculture and tourism will directly promote the improvement of AGTFP in the local region, and this impact has a spatial spillover effect. The direct effect in the central region in China is the strongest, and the spillover effect in the eastern region is the largest. 3) The influence of the agriculture and tourism integration on AGTFP was enhanced with the improvement of ATL, showing a threshold characteristic. From the perspective of subregion, the threshold value of ATL in the eastern region is the lowest, while the threshold value in the western region is the highest. The results of this study provide useful enlightenment for promoting the deep integration of agriculture and tourism and improvement of AGTFP so as to promote the green development of agriculture
Analysis of the effect of anti-tuberculosis treatment and lung injury in patients with tuberculosis combined with underlying disease
Objective·To investigate the impact of complications on the prognosis and lung injury of patients with tuberculosis..Methods·A retrospective cohort study was used for analysis, to select a total of 450 smear-positive tuberculosis (TB) patients, 323 males (71.8%) and 127 females (28.2%), from January to December 2018 at Shanghai Pulmonary Hospital, Tongji University School of Medicine, which were divided into non-complication group and complication group (diabetes, hypertension, liver diseases, kidney diseases and gallbladder diseases). Overall treatment outcomes and lung injuries in TB patients with and without complications were analyzed by using χ2 test. Stratified analysis of the impact of each comorbidity on the prognosis and lung injury of TB patients was performed. Kaplan-Meier analysis was used to analyze the temporal correlation between complications and tuberculosis prognosis.Results·Four hundred and fifty patients with a median age of 33 years were included, 173 of whom had complications: diabetes in 49 cases, hypertension in 23 cases, liver diseases in 83 cases, kidney diseases in 35 cases, and gallbladder diseases in 17 cases. The cure rate of TB patients without complications was 80.5%, which was significantly higher than that of the group with complications (P<0.05); the significantly lower cure rate of TB patients with diabetes, hypertension and kidney diseases at diagnosis was the key cause of anti-tuberculosis treatment failure; TB patients with diabetes and liver diseases had higher lung bacterial load and larger areas of lung damage, and TB patients with diabetes and kidney diseases had higher incidence of pulmonary cavity.Conclusion·Diabetes, hypertension and kidney diseases exacerbate lung damage and lead to lower TB cure rates. Early interventions by clinicians at the time of diagnosis can improve cure rates, shorten treatment time, and reduce medical costs for TB patients
Response to Pegylated Interferon Plus Ribavirin in Patients with Hepatitis C Virus Genotype 6a Infection from Guangdong and Guangxi Province of China
Aim. Our aim is to survey the treatment effect of PEG-IFN plus ribavirin in patients infected with HCV genotype 6a in Guangdong and Guangxi province of China and investigate best course of antiviral treatment for patients with HCV-6a infection. Methods. 515 eligible patients received subcutaneous 180 μg PEG-IFNα-2a or 1.5 μg/kg PEG-IFNα-2b once weekly plus oral ribavirin. Primary outcome was SVR by intention-to-treat analysis. Secondary outcome was RVR, cEVR, ETR, and relapse rate. Results. SVR in patients with HCV-6a infection treated for 48 weeks was comparable to that in patients with HCV-2/3 infection (80.9% versus 82.5%, p=0.812) and higher than that in patients with HCV-1b infection (80.9% versus 67.2%, p=0.014). ETR (98.9% versus 90.6%, p=0.016), virological response at month 3 of end-of- treatment (88.8% versus 76.6%, p=0.044), SVR (80.9% versus 65.6%, p=0.032), and virological response at month 12 of end-of-treatment (76.4% versus 60.9%, p=0.04) in patients with HCV-6a infection treated for 48 weeks were higher than those in patients with HCV-6a infection treated for 24 weeks. Conclusion. SVR in patients with HCV-6a treated for 48 weeks was comparable to that in patients with HCV-2/3 infection and higher than that in patients with HCV-1b infection; patients with HCV-6a infection treated for 48 weeks had a superior treatment response than patients treated for 24 weeks
Extracellular volume quantitation using dual-energy CT in patients with heart failure: Comparison with 3T cardiac MR
Backgrounds: Cardiac magnetic resonance (CMR) T1 mapping and the extracellular volume (ECV) have been developed to quantitative analysis of diffusely abnormal myocardial fibrosis (MF). However, dual-energy CT (DECT) has a potential for calculation of ECV. The aim of this study is to evaluate the feasibility and accuracy of DECT technique in determining the ECV in patients with heart failure, with 3T CMR as the reference. Methods: Thirty-five patients with various reasons of heart failure were enrolled in this study. Both DECT and CMR exams were completed within 24 h. ECVs were calculated, and the relationship between DECT-ECV, CMR-ECV, and other heart function parameters, including left ventricular end systolic and diastolic volume, cardiac output and ejection fraction(LVESV, LVEDV, CO, LVEF), Brain natriuretic peptide (BNP) was determined. All participants gave informed consent, and the study was approved by the institutional review board. Results: The median ECVs on DECT and CMR were 33% (95%CI: 32%–36%) and 30% (95%CI: 30% - 32%), respectively. A good correlation between myocardial ECV at DECT and that at CMR (r = 0.945, P < 0.001) was observed. Bland-Altman analysis between DECT and CMR showed a small bias (2.6%), with 95% limits of agreement of −0.4% and 5.6%. Interobserver agreement for ECV at DECT was excellent (ICC = 0.907). Both ECVs, for DECT and CMR, were inversely associated with LVEF and CO. Conclusion: DECT-based ECV could be an alternative non-invasive imaging tool for myocardial tissue characterization. However, overestimation of the extent of diffuse MF is observed with use of DECT
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