Modelling and simulation of a single slit micro packed bed reactor for methanol synthesis

A mathematical model for a single slit packed microstructured reactor-heat exchanger in the synthesis of methanol from syngas was developed. The model constitutes a simplified 3D-pseudo homogeneous approach for a reaction slit with integrated pillar geometry. Literature kinetic rate expressions for methanol synthesis over commercial Cu/ZnO/support type catalysts were applied at 80 bar total pressure, temperature range of 473-558 K, and syngas composition of H$_{2}$/CO/CO$_{2}$/N$_{2}$:65/25/ 5/5 mol%. The model is found capable of predicting experimental CO conversion data with acceptable accuracy. Superior thermal stability of the microchannel upon variation of different parameters such as contact time, feed gas temperature and reaction temperature were shown. The simulation results also reveal that the microchannel reactor can operate free of performance loss due to concentrations field that may arise from overlaid temperature fields. Simulations have also been used to calculate the rapid temperature transients at the inlet. The agreement between simulation results and experimental data signifies the applicability of the developed model for further design and performance optimization of microstructured reactors for methanol synthesis and other exothermic processes

Melanoma central nervous system metastases: current approaches, challenges, and opportunities

Melanoma central nervous system metastases are increasing, and the challenges presented by this patient population remain complex. In December 2015, the Melanoma Research Foundation and the Wistar Institute hosted the First Summit on Melanoma Central Nervous System (CNS) Metastases in Philadelphia, Pennsylvania. Here, we provide a review of the current status of the field of melanoma brain metastasis research; identify key challenges and opportunities for improving the outcomes in patients with melanoma brain metastases; and set a framework to optimize future research in this critical area

Mammalian cell transfection: the present and the future

Transfection is a powerful analytical tool enabling study of the function of genes and gene products in cells. The transfection methods are broadly classified into three groups; biological, chemical, and physical. These methods have advanced to make it possible to deliver nucleic acids to specific subcellular regions of cells by use of a precisely controlled laser-microcope system. The combination of point-directed transfection and mRNA transfection is a new way of studying the function of genes and gene products. However, each method has its own advantages and disadvantages so the optimum method depends on experimental design and objective

Risk of dementia and mild cognitive impairment in older people with subjective memory complaints: meta-analysis

Objective: To investigate whether people with subjective memory complaints (SMC) but no objective deficits are at increased risk of developing mild cognitive impairment (MCI) and dementia. Method: Major electronic databases were searched till 03/2014, and a meta-analysis was conducted using inception cohort studies. Results: Across 28 studies, there were 29 723 unique individuals (14 714 with SMC and 15 009 without SMC) (mean 71.6 years) followed on average for 4.8 years through to dementia. The annual conversion rate (ACR) of SMC to dementia was 2.33% (95% CI = 1.93%–2.78%) a relative risk (RR) of 2.07 (95% CI = 1.76–2.44) compared with those without SMC (n = 15 009). From 11 studies the ACR of developing MCI was 6.67% (95% CI = 4.70–8.95%). In long-term studies over 4 years, 14.1% (9.67–19.1%) of people with SMC developed dementia and 26.6% (95% CI = 5.3–39.7) went on to develop MCI. The ACR from SMC to dementia and MCI were comparable in community and non-community settings. Conclusion: Older people with SMC but no objective complaints are twice as likely to develop dementia as individuals without SMC. Approximately 2.3% and 6.6% of older people with SMC will progress to dementia and MCI per year

The Effects of Dietary Mobile Apps on Nutritional Outcomes in Adults with Chronic Diseases : A Systematic Review and Meta-Analysis

Abstract Background Dietary interventions are effective prevention and treatment strategies for chronic diseases; however, they require extensive commitment, time, and resources. Dietary mobile applications (apps) have gained popularity and are thus being incorporated into dietary management. Objective The aim of this review is to assess the effects of the use of dietary mobile apps on nutritional outcomes in adults with chronic diseases. Methods A systematic review was conducted following PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines using MEDLINE, PubMed, Embase, and CINAHL databases. The protocol was registered on PROSPERO. Intervention studies evaluating the nutritional outcomes of dietary apps, published in English between January 1, 2007 and November 15, 2017 were included. The methodological quality of included articles was assessed via the Academy of Nutrition and Dietetics\u27 Quality Criteria Checklist: Primary Research. Heterogeneity was confirmed using the I2 index and a random-effects meta-analysis was performed for randomized controlled trials. Estimates of the pooled mean difference were calculated for app usage compared to no app usage. Main outcomes measure Nutritional outcomes, categorized as food-/nutrition-related, anthropometric measurements, pertinent clinical/biochemical data, and nutrition-focused physical findings, were extracted from the included intervention studies. Results Upon completion of the searches, 18,649 articles were identified, and data were extracted from 22 articles. Pooled estimates showed a significantly greater decrease in weight ( “2.45 kg, 95% CI “3.33 to “1.58 kg; P Conclusions The findings of this systematic review and meta-analysis indicate that dietary mobile apps are effective self-monitoring tools, and that their use results in positive effects on measured nutritional outcomes in chronic diseases, especially weight loss

Immune activation in irritable bowel syndrome: can neuroimmune interactions explain symptoms?

Irritable bowel syndrome (IBS) is a functional disorder of the gastrointestinal (GI) tract characterized by pain or discomfort from the lower abdominal region, which is associated with altered bowel habit. Despite its prevalence, there is currently a lack of effective treatment options for patients. IBS has long been considered as a neurological condition resulting from alterations in the brain gut axis, but immunological alterations are increasingly reported in IBS patients, consistent with the hypothesis that there is a chronic, but low-grade, immune activation. Mediators released by immune cells act to either dampen or amplify the activity of GI nerves. Release of a number of these mediators correlates with symptoms of IBS, highlighting the importance of interactions between the immune and the nervous systems. Investigation of the role of microbiota in these interactions is in its early stages, but may provide many answers regarding the mechanisms underlying activation of the immune system in IBS. Identifying what the key changes in the GI immune system are in IBS and how these changes modulate viscerosensory nervous function is essential for the development of novel therapies for the underlying disorder.Patrick A. Hughes, Heddy Zola, Irmeli A. Penttila, L. Ashley Blackshaw, Jane M. Andrews, and Doreen Krumbiege

The Wnt Receptor, Lrp5, Is Expressed by Mouse Mammary Stem Cells and Is Required to Maintain the Basal Lineage

Background: Ectopic Wnt signaling induces increased stem/progenitor cell activity in the mouse mammary gland, followed by tumor development. The Wnt signaling receptors, Lrp5/6, are uniquely required for canonical Wnt activity. Previous data has shown that the absence of Lrp5 confers resistance to Wnt1-induced tumor development. Methodology/Principal Findings: Here, we show that all basal mammary cells express Lrp5, and co-express Lrp6 in a similar fashion. Though Wnt dependent transcription of key target genes is relatively unchanged in mammary epithelial cell cultures, the absence of Lrp5 specifically depletes adult regenerative stem cell activity (to less than 1%). Stem cell activity can be enriched by.200 fold (over 80 % of activity), based on high Lrp5 expression alone. Though Lrp5 null glands have apparent normal function, the basal lineage is relatively reduced (from 42 % basal/total epithelial cells to 22%) and Lrp52/2 mammary epithelial cells show enhanced expression of senescence-associated markers in vitro, as measured by expression of p16 Ink4a and TA-p63. Conclusions/Significance: This is the first single biomarker that has been demonstrated to be functionally involved in stem cell maintenance. Together, these results demonstrate that Wnt signaling through Lrp5 is an important component o