Lessons from probiotic-host interaction studies in murine models of experimental colitis

In inflammatory bowel diseases (IBD), it is known that besides genetic and environmental factors (e.g. diet, drugs, stress), the microbiota play an important role in the pathogenesis. Patients with IBD have an altered microbiota (dysbiosis) and therefore, probiotics, defined as 'live micro-organisms that when administered in adequate amounts can confer a health benefit on the host', have been suggested as nutritional supplements to restore these imbalances. The best response on probiotics among the different types of IBD appears to be in the case of ulcerative colitis. Although probiotics show promise in IBD in both clinical and animal studies, further mechanistic studies are necessary to optimize the use of probiotics as supporting therapy in IBD. Murine models of experimental colitis have been used for decades to study this pathology, and these models have been proven useful to search for new therapeutic approaches. The purpose of this review is to summarize probiotic-host interaction studies in murine models of experimental colitis and to evaluate how these models can further help in understanding these complex interactions. Unraveling the molecular mechanisms behind the beneficial effects will assist in better and possibly more efficient probiotic formulations.     

Solving the inverse problem for aggregation in activated sludge flocculation using a population balance framework.

Many systems contain populations of individuals. Often, they are regarded as a lumped phase, which might, for some applications, lead to inadequate model predictive power. An alternative framework, Population Balance Models, has been used here to describe such a system, activated sludge flocculation in which particle size is the property one wants to model. An important problem to solve in population balance modelling is to determine the model structure that adequately describes experimentally obtained data on for instance, the time evolution of the floc size distribution. In this contribution, an alternative method based on solving the inverse problem is used to recover the model structure from the data. In this respect, the presence of similarity in the data simplifies the problem significantly. Similarity was found and the inverse problem could be solved. A forward simulation then confirmed the quality of the model structure to describe the experimental data.     

A meta-analytic investigation of the relationship between attentional bias and subjective craving in substance abuse.

Theoretical models of addiction suggest that attentional bias for substance-related cues should be associated with self-reported craving. The authors evaluated the strength of the association by performing a meta-analysis on 68 independent data sets from which correlation coefficients between subjective craving and attentional bias indices were derived. Additional stratified analyses were conducted to identify any variables that might moderate the association between craving and attentional bias. The primary meta-analysis indicated a significant, albeit weak (r = .19), association between attentional bias and craving. Stratified analyses revealed that the association was larger for illicit drug and caffeine craving than for alcohol and tobacco craving, larger for direct measures of attention (eye movement measures and event-related potential measures) than for indirect behavioral measures of attentional bias, and larger when craving strength was high than when it was low (all ps     

Assessment of mass transfer coefficients in coalescing slug flow in vertical pipes and applications to tubular airlift membrane bioreactors

One of the operational challenges associated with membrane bioreactors (MBRs) is the fouling of the membranes. In tubular side-stream MBRs, fouling reduction can be achieved through controlling the hydrodynamics of the two-phase slug flow near the membrane surface. The two-phase slug flow induces higher shear stresses near the membrane surface, which generate high mass transfer coefficients from the surface to the bulk region. However, measuring the mass transfer coefficient is difficult in complex heterogeneous mixtures like activated sludge and existing techniques (e.g. electrochemical methods) cannot be applied directly. As an alternative, in this work, a multidisciplinary approach was selected, by exploiting dimensionless analysis using the Sherwood number. Mass transfer coefficients were measured at various superficial velocities of gas and liquid flow in a tubular system. Due to the variability of the mass transfer coefficient obtained for each experimental condition, the results were compiled into, mass transfer coefficient histograms (MTH) for analysis. A bimodal MTH was observed, with one peak corresponding to the mass transfer induced by the liquid flow, and the other peak induced by the gas flow. It was noted that coalescence of bubbles affects the MTH. Coalescence increased the “width” of the peaks (i.e. the estimate of the variability of the mass transfer coefficient) and the height of the peak (i.e. amount of time that a mass transfer coefficient of a given value is maintained). A semi-empirical relationship based on the Lévêque relationship for the Sherwood number (mass transfer coefficient) was formulated for the laminar regime. A test case comparison between water and activated sludge was performed based on full-scale airlift MBR operational conditions. It was found that the Sherwood number in the non-Newtonian case is 8% higher than that in the Newtonian case.     

A real option-based supply chain project evaluation and scheduling method

Supply chain departments spend their time managing numerous projects that will improve and maintain their supply chains. Recent literature has most frequently described the content of these projects and their scheduling but neglected to include risk and uncertainty in the expected cost, profits and time durations of these projects. In this article, we have introduced real option valuation (ROV) to supply chain project scheduling as a flexible method to quantify those risks. Our proposed two-step framework links ROV to all relevant constraints of a multi-project set-up by binary fuzzy goal programming. We applied the framework to a real-life case study data of 21 projects that were facing numerous risks and resource constraints. The results show how scheduling performance improved in comparison to methods ignoring risk and uncertainty (e.g. net present value-based scheduling). For validation we conducted hypothesis tests and sensitivity analysis, and provide an in-depth discussion. The findings contribute to research and practice by capturing project-related risks and managerial flexibilities in general and in supply chains in particular.     

Silicon–glass instrumented solid-phase extraction–zone electrophoresis microchip with thin amorphous silicon film electrodes: performance in immunoaffinity analysis

Silicon–glass microchips were designed and fabricated for on-chip solid phase extraction (SPE) and zone electrophoresis studies. The solvent channels for extraction and the separation channels for analyses were fabricated sequentially on the silicon device. Electrical contacts were integrated in a fused silica glass lid. Amorphous silicon thin film electrodes were fabricated for high voltage and conductivity detection. A chip installation rack with electrical and fluidic contacts was constructed to facilitate the experiments. Simulation was used to elucidate both the liquid flow and the electric field distribution. The operational performance of the microchips was demonstrated by using a fluorescein isothiocyanate (FITC)-labelled testosterone derivative as the model analyte and fluorescein as both the negative control and the calibration compounds. In SPE an immunosorbent, based on recombinant anti-testosterone Fab-fragments, was immobilized to activated Sepharose gel. Simultaneous monitoring of the movement of FITC-testosterone from SPE cavity through the channel to the detection point was performed with a laser-induced fluorescence detector. The observed limit of detection for FITC-testosterone was 2 μM.     

Supramolecular β‐Sheet Suckerin–Based Underwater Adhesives

Nature has evolved several molecular strategies to ensure adhesion in aqueous environments, where artificial adhesives typically fail. One recently‐unveiled molecular design for wet‐resistant adhesion is the cohesive cross‐β structure characteristic of amyloids, complementing the well‐established surface‐binding strategy of mussel adhesive proteins based on 3,4‐l ‐dihydroxyphenylalanine (Dopa). Structural proteins that self‐assemble into cross β‐sheet networks are the suckerins discovered in the sucker ring teeth of squids. Here, light is shed on the wet adhesion of cross‐β motifs by producing recombinant suckerin‐12, naturally lacking Dopa, and investigating its wet adhesion properties. Surprisingly, the adhesion forces measured on mica reach 70 mN m^?1, exceeding those measured for all mussel adhesive proteins to date. The pressure‐sensitive adhesion of artificial suckerins is largely governed by their cross‐β motif, as evidenced using control experiments with disrupted cross‐β domains that result in complete loss of adhesion. Dopa is also incorporated in suckerin‐12 using a residue‐specific incorporation strategy that replaces tyrosine with Dopa during expression in Escherichia coli. Although the replacement does not increase the long‐term adhesion, it contributes to the initial rapid contact and enhances the adsorption onto model oxide substrates. The findings suggest that suckerins with supramolecular cross‐β motifs are promising biopolymers for wet‐resistant adhesion.     

AKR‐Prüfverfahren: Auf dem Weg zur Performance‐Prüfung

ASR Test Methods: On the Way to Performance Testing To avoid a deleterious alkali silica reaction in concrete structures (ASR) the alkali‐reactivity potential of aggregates must be known. Then appropriate preventive measures can be applied when reactive aggregates are used. In the past the alkali reactivity of dense aggregates was tested with the concrete prism test with the 40 °C fog chamber method. Comparative investigations with storage in an outdoor exposure site confirm, that reactive aggregates, that have to be tested according to Part 3 of the Alkali Guidelines of the German Committee for Reinforced Concrete (DAfStb), can be identified in the laboratory test. For a quick assessment the 60 °C concrete prism test can be used as an alternative. Its suitability was confirmed by a comparison to the 40 °C fog chamber method. The assessment of the suitability of specific concrete compositions in performance tests is necessary to avoid excluding aggregates or cements unnecessarily from application as well as to simulate an external supply of alkalis if necessary. These tests give information about the possible appearance of a deleterious ASR with a specific concrete composition depending on the exposure or humidity class of the concrete. To develop such a performance test, the Research Institute of the Cement Industry examined, amongst others, cores from affected and unaffected concrete pavements in concrete prism tests with the 40 °C fog chamber method and 60 °C concrete prism test with and without an external supply of alkalis.     

Benecol——一种有效、安全降低血清胆固醇水平的独特食品配料

在世界范围内,心血管疾病--冠心病(CHD)、中风、周围动脉疾病的患病数量正在增加.据世界卫生组织(WHO)统计估计,每年大约有1600万人死于各种形式的心血管疾病.高血清胆固醇足导致各种心血管疾病的主要危险因素之一.近来,通过饮食方法如功能食品来降低胆固醇水平已经引起了极大关注.植物甾醇和植物甾烷醇是动物胆固醇的植物等价物,因为它们在植物细胞中的作用与胆固醇在动物细胞中的作用是一样的.如果在日常的饮食当中含有足量的植物甾醇或植物甾烷醇,则它们可以有效地降低胃肠道中对胆固醇的吸收量,从而降低血清胆固醇浓度.植物甾烷醇酯是世界上第一个基于植物甾醇的降低胆固醇的商业食品配料.1995年芬兰首次生产出添加植物甾烷醇酯的降胆固醇食品.如今,在全世界的24个国家销售Benecol品牌的各种植物甾烷醇酯强化食品,包括植物黄油、酸奶、牛奶、橙汁、通心粉等.Benecol食品含有植物甾烷醇酯,专门针对想通过饮食方法降低血清胆固醇水平的人群.植物甾烷醇酯的安全性已经得到了严格的安全性测试,并得到了40多项人体临床研究的证实.国际专业团体已经充分肯定了植物甾烷醇酯食品的降低胆固醇的功效.