电化学联用技术研究微生物的胞外电子传递机制

胞外电子传递(EET)是指氧化还原反应所产生的电子在微生物细胞内和细胞外的电子受体/电子供体之间互相转移的过程,这一过程伴随着能量和物质的转化。阐明EET机制是提高微生物能量和物质转化效率的基础,为元素的生物地球化学循环、金属防腐以及生物电化学系统的应用等提供理论支撑。电化学技术作为研究电极/溶液界面电子转移的简便、有效方法,在研究微生物的直接电子传递和间接电子传递机制中发挥了重要的作用,也促进了EET机制的研究从宏观层面到微观层面不断深入。本文综述了研究微生物EET机制所涉及的电化学联用技术(包括微电极、扫描电化学显微镜、电化学联用光学显微镜和光谱电化学等);详细介绍了这些电化学联用技术的功能和优势;重点阐述了这些电化学联用技术如何推动着EET机制的研究,从宏观的生物膜层面到微观的单个微生物细胞、蛋白和分子层面不断深入;展望了新的电化学联用技术在EET研究领域的应用前景。国家重点研发计划项目项目(No.2017YFA0206500);;国家自然科学基金项目(No.21777155,21773198,U1705253,21621091)资助~

扫描电化学显微镜用于研究生物膜微环境的电子传递

生物电化学系统(BESs)的核心是生物膜在电极/溶液界面的电子传递反应,研究生物膜微区环境中的电子传递有助于阐明微生物的胞外电子传递(EET)机制,从而有针对性地提高BESs中的电子转移效率。微生物的EET机制包括直接电子传递和间接电子传递,由于生物膜组成复杂,含有多种分泌物、胞外聚合物等,常规电化学方法只能从生物膜宏观层面研究EET机制,无法有效区分这两种电子传递途径的贡献。本文采用电化学循环伏安方法研究了电子穿梭体二茂铁甲醇(FcMeOH)与希瓦氏菌(Shewanella)相互作用的界面过程;基于扫描电化学显微技术构建了穿透模式,通过微电极介导FcMeOH与Shewanella反应,收集仅来自间接电子传递途径产生的电流,同时测定了Shewanella在电极/溶液界面的氧化还原性质和空间分布。本论文将电化学扫描探针显微技术应用于EET的研究,从物理化学角度揭示微生物在代谢过程中与外界的电子传输机制。国家重点研发计划项目(2017YFA0206500);;国家自然科学基金(21777155,21773198,U1705253,21621091)资助~

湿地变形菌门甲烷氧化菌群的缺氧能量代谢

甲烷氧化菌以甲烷作为碳源和能源,在全球甲烷平衡和温室效应控制中扮演着重要角色。甲烷生物氧化过程跨越不同氧化还原生态位,近年来的研究表明,在湿地缺氧生态位下变形菌门甲烷氧化菌具有代谢潜力,但其能量代谢机制尚不清楚。本研究基于生物电化学技术、矿物学实验及微生物组学方法,结果表明变形菌门甲烷氧化菌主导的菌群具有直接和间接胞外电子传递潜力;在氧气耗尽时,甲烷氧化菌群可利用水铁矿作为电子受体完成能量代谢过程,缺氧体系中γ-Proteobacteria纲的甲烷氧化菌和非甲烷氧化微生物共同驱动铁矿还原。本研究探讨了变形菌门甲烷氧化菌主导菌群的缺氧能量代谢过程,拓展了反硝化厌氧甲烷氧化菌及厌氧甲烷氧化古菌主导的缺氧甲烷氧化理论,为甲烷生物控制提供了理论支持

Fabrication and Application of Low-cost Microfluidic Analytical Devices Based on Paraffin-Heptane Treated Paper Substrate

介绍了一种新型的使用石蜡庚烷溶液制备纸基微流控分析装置的工艺,操作更加简单迅速,成本更加低廉。使用混合样品溶液进行测试,证明该装置可以完成对蛋白质、葡萄糖和PH值的同时检测,并可以用于定量分析。纸基微流控分析装置对样品检测的精度范围分别为:牛血清蛋白2.0x10-5~1.00x10-4MOl/l,葡萄糖0.02~0.1 MOl/l。并对加热处理过程中微流控通道壁的扩散现象进行了初步研究,发现加热前后通道壁厚度的变化呈线性规律。Paper is an ideal substrate material for low-cost diagnostic devices and shows a great potential in the fabrication of microfluidic paper-based analytical devices( μPADs).As one of the hot research fileds,a variety of materials and techniques have been proposed to fabricate μPADs.In this paper,we introduced a cheap,simpler and faster fabrication procedure,in which paraffin-heptane solution was used,toward this target.It is confirmed that as-developed protocol could be used for the simultaneous diagnostics of protein, glucose and pH.In addition,it is also applicable for quantitative analysis.The detection ranges of fabricated μPAD for bovine serum albumin and glucose were 2.0 × 10- 5~ 1.00 × 10- 4mol / L and 0.02 ~ 0.1 mol / L, respectively.This paper also preliminarily studied the spreading phenomena of microfluidic channel barrier during heating treatment.We found that the thickness of barrier followed a linear discipline.厦门大学化学化工学院和教育部博士点新教师基金项目(20120121120018); 国家自然科学基金(青年基金)项目(21205099)~

Comparison between the digestive behaviors of a new in vitro rat soft stomach model with that of the in vivo experimentation on living rats - Motility and morphological influences

Xiamen UniversityA 'near-real' in vitro stomach model should not only resemble of the biochemical and physiological conditions found in the real stomachs, but also possess their geometrical and morphological details. In this work, quantitative evidences regarding the physiological relevant morphology including wrinkles on the inner-surface of a new rat model stomach, which assisted the compression and digestion behavior of the dynamics in vitro rat stomach (DIVRS), have been presented. A good repeatability in the tests on the DIVRS is shown, compared with the in vivo experiments of the living rats. However the digestion efficiency and the buffering capacity in the DIVRS were lower than the in vivo systems, most likely due to the limited motility mechanism of the movement of the model stomach system. Further improvements are needed to make the DIVRS more attractive for practical applications. (C) 2013 Elsevier Ltd. All rights reserved

内蒙古包头地区40岁及以上人群抗血小板聚集类药物使用现状及影响因素的真实世界研究 Real World Study on the Current Status and Influencing Factors of Antiplatelet Aggregation Drugs Use among People Aged 40 and above in Baotou, Inner Mongolia

目的 明确真实世界内蒙古包头地区40岁及以上人群抗血小板聚集类药物的使用情况，以及不同人群服药率的影响因素。 方法 采用以居委会、村委会为单位的多级、整群、随机抽样方法，在2021年6月—2022年9月抽取包头地区40岁及以上常住居民。采用调查问卷形式收集研究对象的一般资料、既往病史及抗血小板聚集类药物使用情况。按照是否有心脑血管疾病（cardio cerebrovascular diseases，CVD）以及是否存在CVD危险因素将研究对象分为3组：CVD组（既往患CVD人群）、CVD危险因素组（无CVD病史，有以下1个或多个CVD危险因素：高血压、糖尿病、高血脂、吸烟史、饮酒史、肥胖）、健康对照组（无CVD病史，无CVD危险因素）。比较3组间一般资料的差异。根据是否服用抗血小板聚集类药物，将CVD组和CVD危险因素组的研究对象分别分为服药组和未服药组，采用单因素和多因素分析调查两组中影响服药的相关因素。 结果 ①研究共纳入2100例有效调查对象，其中CVD组298例（14.2%）、CVD危险因素组1040例（49.5%）、健康对照组762例（36.3%）。3组人群中抗血小板聚集类药物应用率分别为51.68%（154例）、33.46%（348例）和6.69%（51例），组间差异有统计学意义（P＜0.001）。②多因素分析显示，CVD组中较高学历（以小学及以下学历为基线，高中OR 2.429，95%CI 1.277～4.619，P=0.007、本科及以上学历OR 8.500，95%CI 1.015～12.165，P=0.048）以及合并糖尿病（OR 2.820，95%CI 1.377～5.777，P=0.005）的患者更倾向于应用抗血小板聚集类药物；CVD危险因素组中抗血小板聚集类药物应用率受个人经济收入（以＜1.0万/年为基线，＞5.0万/年  OR 18.547，95%CI 8.948～38.444，P＜0.001）、学历（以小学及以下学历为基线，本科及以上学历OR 5.512，95%CI 1.736～17.495，P=0.004）、吸烟史（OR 0.712，95%CI 0.541～0.936，P=0.015）、BMI（与低BMI患者相比，BMI正常OR 5.640，95%CI 1.172～27.144，P=0.031）；肥胖 （OR 8.440，95%CI 1.684～42.293，P=0.009）、患高血压（OR 246.029，95%CI 112.44～538.337， P＜0.001）、患糖尿病（OR 117.689，95%CI 51.041～271.367，P＜0.001）等因素的独立影响。③CVD组和CVD危险因素组的服药原因中医师处方占比最高，分别为83.12%和79.60%；健康对照组服药原因从高到低依次为自觉应该服用（47.06%）、亲友介绍（29.41%）、广告媒体宣传（13.73%）和医师处方（9.80%）。 结论 内蒙古包头地区40岁及以上人群中使用抗血小板聚集类药物进行CVD一级、二级预防的情况不理想，不同人群服药影响因素各不相同，且存在健康人群不规范和错误用药情况。 Abstract: Objective To clarify the use of antiplatelet aggregating drugs in people aged 40 years and above in Baotou area of Inner Mongolia in the real world, and the factors influencing the rate of taking drugs in different populations. Methods A multilevel, whole-group, random sampling method with neighborhood and village committees was used to draw permanent residents aged 40 years and above in Baotou area from June 2021 to September 2022. A questionnaire was used to collect general information, past medical history and the use of anti-platelet aggregating drugs from the study population. The subjects were divided into three groups according to the presence or absence of cardio cerebrovascular diseases (CVD) and the presence of CVD risk factors: CVD group (with previous CVD), CVD risk factor group (no history of CVD, with one or more of the following CVD risk factors: hypertension, diabetes mellitus, hyperlipidemia, history of smoking, history of alcohol consumption, obesity), the healthy control group (no history of CVD, no risk factors for CVD). The differences in general information between the 3 groups were compared. The subjects in the CVD group and the CVD risk factor group were divided into the medication group and the non-medication group according to whether they were taking antiplatelet aggregation drugs or not, and the relevant factors affecting medication taking in the two groups were investigated using univariate and multifactorial analyses. Results ①A total of 2100 validated subjects were included in the study, including 298 cases (14.2%) in the CVD group, 1040 cases (49.5%) in the CVD risk factor group, and 762 cases (36.3%) in the healthy control group.The rates of taking antiplatelet aggregation drugs in the three groups were 51.68% (154 cases), 33.46% (348 cases), and 6.69% (51 cases), respectively, with statistically significant differences between groups (P50 000/year, OR 18.547, 95%CI 8.948-38.444, P<0.001), education (primary school education or less as the baseline, bachelor's degree and above, OR 5.512, 95%CI 1.736-17.495, P=0.004), smoking history (OR 0.712, 95%CI 0.541-0.936, P=0.015), normal BMI (compared to low BMI patients, OR 5.640, 95%CI 1.172-27.144, P=0.031), obesity (OR 8.440, 95%CI 1.684-42.293, P=0.009), having hypertension (OR 246.029, 95%CI 112.44-538.337, P<0.001), having diabetes (OR 117.689, 95%CI 51.041-271.367, P<0.001) were independently influenced by other factors. ③The reasons for taking medication in the CVD and CVD risk factor groups were the highest among physician prescriptions, 83.12% and 79.60%, respectively; the reasons for taking medication in the healthy control group were, in descending order, consciously should take it (47.06%), introduced by friends and relatives (29.41%), advertised media (13.73%), and physician prescription (9.80%). Conclusions The use of antiplatelet aggregation drugs for primary and secondary prevention of CVD among people aged 40 years and above in Baotou, Inner Mongolia is not satisfactory, and the factors influencing the use of drugs vary among different groups, and there are cases of irregular or even incorrect use of drugs among healthy people

Digestive behaviours of large raw rice particles in vivo and in vitro rat stomach systems

In vivo (testing on living animals) and in vitro experiments are the two main approaches to studying the digestive behaviours of different kinds of foods within the gastrointestinal (GI) tract. In our previous work, an initial dynamic in vitro rat stomach (DIVRS) system was created to investigate its digestion capacity of casein powder (water suspension) using an angled plate driven by a motor and an eccentric shaft to create pulsing compression on a polymeric rat stomach model. This indicated that the system was effective in showing the correct trends of the digestion and emptying of solid or semi-solid food matter with small particle size. In this paper, raw rice particles (larger size) were used as model food to study their digestive behaviours with the aid of the same DIVRS and a simple stirred tank reactor (STR). These results were then compared with the in vivo experiments of the living rats. Moreover, the effect of rotating speeds of the impeller in the STR on the digestive behaviours of raw rice particles was also investigated. Better repeatability and similar digestive behaviours were achieved in both the STR and the DIVRS than that could be obtained in the living rats. Both of the STR and DIVRS were effective in reducing the large raw rice particles into small ones. However, the digestive efficiency and buffering ability in vitro were lower than that in vivo due to less sufficient mixing of ingested materials. The stirring speed had a significant influence on the particle digestion in the STR; so, stirring speed must be considered in terms of using STR as an in vitro digestion system for studying digestive behaviours in the GI tract. The mixing behaviour needs to be quantified and understood. Further improvement has to be made by setting up more powerful contractions within the walls on the DIVRS to make it more attractive for practical applications. ? 2014 Published by Elsevier Ltd

Study on the dissolution of heat-induced ovalbumin gel in alkaline solutions relevant to the removal of fouling deposits

Xiamen UniversityHeat-induced whey protein concentrate gels (HIWPCG) have previously been used to simulate milk fouling and cleaning processes. The related research has generated considerable knowledge, which is of practical interest. In the current study, heat-induced ovalbumin gels (HIOVAG) have been employed to investigate the dissolution process (related to chemical cleaning process). Both HIOVAG and HIWPCG are sensitive to NaOH solution, which is a common cleaning fluid in food industry. In contrast to the HIWPCG behavior, HIOVAG dissolution presents no optimal NaOH concentration where the rate of dissolution is highest. The dissolution temperature was found to positively influence the dissolution process of HIOVAG, i.e. the dissolution rate increased with increasing dissolution temperature. In addition, ovalbumin (OVA) concentration in HIOVAG was found to be another important factor influencing the dissolution process. However, the stirring speed (convection) and heating time had no effect in the range tested, indicating that the process was internally limited. (C) 2012 Elsevier Ltd. All rights reserved

Experimental investigation of egg ovalbumin scaling on heated stainless steel surface and scale-removal compared with that of whey protein

Fouling and cleaning on a heat exchanger surface during milk processing have been studied extensively in the past due to their great importance in energy, product quality, and safety. However, little information is available for egg ovalbumin (OVA) fouling and cleaning behavior. In the present work, fouling and cleaning behaviors of OVA were investigated using a real-time monitoring system for heat transfer coefficient. A comparison was made between the behavior of whey protein concentrate (WPC) and that of OVA. WPC has been well studied which can be used as a benchmark. Ultrasonic cleaning was also applied to investigate the cleaning behavior of OVA fouling. Results have shown that OVA created more thermal resistance than WPC in the 2. h fouling process. It was also much more difficult to remove the OVA deposit than the WPC fouling. Different from what were observed from WPC deposit, there was no optimal cleaning rate for OVA deposit in the NaOH concentration range tested (0-2.0. wt%), while WPC fouling is known to have the highest cleaning rate around 0.5. wt% NaOH concentration at moderate temperatures. ? 2013

Investigation on a soft tubular model reactor based on bionics of small intestine-residence time distribution

The human small intestine is responsible for virtually all nutrient uptake and more than 95% of the water absorption in digestion, which is attributed to the vast mucosal surface area and the peristalsis of small intestine. Under the broad conceptual framework of bio-inspired chemical process engineering, by mimicking the structure and functions of small intestine, a flexible tubular reactor with villous protrusions distributed evenly on the inner wall was designed and constructed in this study. In order to understand the flow behavior in the reactor, the residence time distribution (RTD) of fluid particles in the reactor was measured by introducing electrochemical active tracer. Also, a simple mechanism of peristalsis was introduced, and its effects on the RTD in the reactor were investigated. The experimental results showed that the tailing of RTD function curve in the small intestine model reactor was extended significantly compared to a normal tubular reactors. The residence time and mixing of fluid (particles) in the reactor can be regulated efficiently by controlling the peristaltic actions (frequency and location)