Helicobacter pylori and Crohn's disease: A retrospective single-center study from China

AIM: To investigate the association between Helicobacter pylori (H. pylori ) infection and the prevalence of Crohn's disease (CD). METHODS: Subjects were selected from patients admitted the gastrointestinal (GI) department at The First Affiliated Hospital School of Medicine (Zhejiang University)for abdominal pain, hematochezia, diarrhea and other GI symptoms between January 2008 and September 2012. CD was diagnosed by endoscopy and biopsy. H. pylori infection was detected by a 14 C-urea breath test and culturing of the biopsy sample. Demographic, anthropometric and serologic data were collected for each patient. H. pylori infection rate was compared between CD and control groups, followed by a subgroup analysis based on extent and severity of CD. Student's t , Mann-Whiney U , and χ 2 tests were used to analyze the data. RESULTS: A total of 447 patients were analyzed, including 229 in the CD group and 248 in the control group. There were no significant differences in age, sex, and rates of hypertension or diabetes. However, the CD group showed significantly higher rates of smoking history (34.9% vs 18.1%), alcohol intake (17.4% vs 8.1%), white blood cell count (9.7 ± 2.9 × 10 9 /L vs 4.3 ± 0.9 × 10 9 /L), and C-reactive protein (36.3 ± 20.8 mg/L vs 5.5 ± 2.3 mg/L) but lower body mass index (24.5 ± 2.0 kg/m 2 vs 26.0 ± 2.2 kg/m 2 ) than the control group. The H. pylori infection rate in the CD group was 27.1%, significantly lower than that of 47.9% in the control group. Furthermore, the H. pylori infection rates in patients with colonic, small intestine, ileocolonic and extensive CD were 31.1%, 28.9%, 26.8% and 25.9% respectively, all of which were significantly lower than in the control group. Finally, the H. pylori infection rates in patients with remission, moderate and severe CD were 34.3%, 30.7% and 22.0% respectively, which were also significantly lower than in the control group. CONCLUSION: Lower H. pylori infection in CD patients suggests a correlation between bacterial infection and CD, suggesting caution when considering H. pylori eradication in CD patients.

The effect of agglomerate on micro-structural evolution in solid-state sintering

Discrete element method （DEM） is used in the present paper to simulate the microstructural evolution of a planar layer of copper particles during sintering. Formation of agglomerates and the effect of their rearrangement on densification are mainly focused on. Comparing to the existing experimental observations, we find that agglomerate can form spontaneously in sintering and its rearrangement could accelerate the densification of compacts. Snapshots of numerical simulations agree qualitatively well with experimental observations. The method could be readily extended to investigate the effect of agglomerate on sintering in a three- dimensional model, which should be very useful for understanding the evolution of microstructure of sintering systems.

Factors influencing particle agglomeration during solid-state sintering

Discrete element method （DEM） is used to study the factors affecting agglomeration in three-dimensional copper particle systems during solid-state sintering. A new parameter is proposed to characterize agglomeration. The effects of a series of factors are studied, including particle size, size distribution, inter-particle tangential viscosity, tem- perature, initial density and initial distribution of particles on agglomeration. We find that the systems with smaller particles, broader particle size distribution, smaller viscos- ity, higher sintering temperature and smaller initial density have stronger particle agglomeration and different distribu- tions of particles induce different agglomerations. This study should be very useful for understanding the phenomenon of agglomeration and the micro-structural evolution during sin- tering and guiding sintering routes to avoid detrimental ag- glomeration.

基于正交试验的空调室外机顶板优化设计

In this paper,the modal analysis of an air conditioner outdoor unit is carried out and the simulation results are compared with the experimental results to verify its accuracy.Aseparate structural optimization analysis is performed for the top plate,and the compression bars of the top plate are changed from transverse to vertical placement.The simulation results show that the natural frequency and stiffness of the top plate are improved.Under the premise of vertical placement of the compression bars,a three-factor,three-level orthogonal test is conducted to find the optimal combination of low-order natural frequency and high-order natural frequency in the given range.

Growth of AgBr/Ag_(3)PO_(4) Heterojunction on Chitosan Fibers for Degrading Organic Pollutants

Using Fiber as the based material for photocatalyst particles is favorable for their recovery,thereby avoiding the photocatalyst particles cause secondary pollution to water environment.In this work,the AgBr and Ag_(3)PO_(4) photocatalyst particles were loaded onto the surface of chitosan fiber(CF)via chelation and in situ anion-exchange method.The photocatalytic results illustrated that the AgBr/Ag_(3)PO_(4)/CF composites displayed the best photocatalytic performance when the mass ratio of Ag_(3)PO_(4) and AgBr onto the CF was approximately 1:0.15,their degradation rate can reach 98.1%for the methyl orange(MO)solution,this value far exceeded those of pure CF,AgBr/CF composites,and Ag_(3)PO_(4)/CF composites.Besides,the AgBr/Ag_(3)PO_(4)/CF composites also shown excellent durability,after the fifth cycle,they still maintained a decolorization rate of 86.4%for the MO solution,while the Ag_(3)PO_(4)/CF composites maintained a decolorization rate of only 70.7%.Based on these results,we consider that the AgBr/Ag_(3)PO_(4)/CF composites have high practical interest in environmental remediation.

Citric acid reduces the decline in P300 amplitude induced by acute alcohol consumption in healthy adults

Event-related potential (ERP) is a reliable neuroelectric measure of brain activity that helps to confirm the assessment of mental status and cognitive impairment. Many studies have reported that alcoholics show a significantly lower ERP P300 amplitude than the norm. In the present study, ERP P300 waves were measured to evaluate the effect of citric acid on cognitive function during excessive alcohol consumption in healthy adults. Five volunteers were selected through clinical interview, physical examination, and psychiatric assessment for participation in this study. In a double-blind placebo-controlled before-after design, each subject was treated with 5 ml/kg body weight alcohol, 5 ml/kg body weight alcohol and 1 mg citric acid, or a placebo on three separate occasions, one week apart. ERP P300, blood biochemical indicators, blood alcohol concentrations (BACs) and acetaldehyde concentrations were assessed. Repeated measure analysis of variance (ANOVA) with a within-subjects factor was used to evaluate differences in blood biochemical indicators, BACs, blood acetaldehyde concentrations, and ERP P300 in the three sessions of assessments. Several blood biochemical indicators showed significant differences between treatments, including the levels of cholinesterase (CHE), total bile acid (TBA), triglyceride (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), very low-density lipoprotein cholesterol (VLDL-C), and glycylproline dipeptidyl aminopeptidase (GPDA). BACs after consumption of alcohol alone or citric acid with al- cohol were significantly higher compared to those after placebo treatment (P<0.05). There were no significant dif- ferences in blood acetaldehyde concentrations between the treatments. The P300 amplitudes on the frontal (Fz), central (Cz), and parietal (Pz) regions of the scalp after consumption of alcohol were significantly lower than those after consumption of the placebo or citric acid with alcohol (P<0.05), while there were no significant differences between the latter two treatments. The results of this study suggest that citric acid could reduce the decline in ERP P300 amplitude and cognitive ability induced by acute alcohol consumption. It may also affect some blood biochemical indicators, but the specific mechanisms need further research.

后掠角及反角可控的吻切锥乘波体设计方法

目的:在飞行器设计中,后掠角及反角会对飞行器的升阻比及横向静稳定性带来影响。本文基于吻切锥乘波体设计方法,将后掠角及反角引入到乘波体的设计过程中,以期实现吻切锥乘波体后掠角及反角的可控设计。创新点:1.通过理论推导建立后掠角及反角与吻切锥乘波体设计中前缘线在水平面投影型线以及激波底部型线的关系;2.通过数值计算,研究后掠角及反角研究对吻切锥乘波体升阻比及横向静稳定性的影响。方法:1.引入基于水平投影型线的吻切锥乘波体设计方法,给出一种前缘点求解方案(图2和4);2.通过理论推导,构建设计参数(后掠角与反角)与乘波体设计输入型线的关系(公式(10)和(11));3.通过数值模拟,验证设计方法的可行性和有效性(图14和15),以及分析非设计点和设计点下后掠角及反角对乘波体升阻比及横向静稳定性的影响(图17~19,21~23)。结论:1.考虑到最大升阻比,后掠角仅在亚音速和跨/超音速时对升阻比起作用,在高超音速时其影响几乎可以忽略;2.在高超音速时,反角会对升阻比产生影响;3.对于乘波器的设计,考虑横向静稳定性时,反角比后掠角更重要;4.下反角有利于横向静稳定性。