27 research outputs found

    Production of microemulsion by membrane emulsification: Comparison of empty ceramic tube membrane and membrane equipped with static turbulence promoters

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    Membrane emulsification (ME) is a relatively new technique for the highly controlled production of particulates, which helps to obtain a narrower distribution compared to other emulsification techniques such as homogenizers or ultrasound. Benefits of membrane emulsification for food applications include the low shear properties and the uniform size distribution. In this process, the dispersed phase (oil) is pressed through the pores of a microporous membrane directly into the continuous phase (water) flowing tangentially to the membrane surface. The purpose of the emulsification experimentations was to find and model operating conditions of the operation. In laboratory experiments from conventional, commercial grade sunflower oil (dispersed phase) and from distilled water (solid phase), emulsions were prepared. The ceramic tube membrane with nominal pore size of 1.4 μm was used in the experiments (ZrO2). In order to increase the shear-stress near the membrane wall (influence the characteristics of the flow regime of the continuous phase), a kind of self-fabricated helical-shaped-ribbon reducer was installed inside the tube membrane

    Examination of whey de-fatting by enhanced membrane filtration

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    The largest quantities of by-products of dairy processing originates from the cheese making. Whey proteins are used for animal feeding and human nutrition as well, for example in dry soups, infant formulas, and supplements. The fat components of the whey might impair its use. The aim of our experiments was to investigate the separation of the lipid fraction of whey. The microfiltration is said to be a gentle and energy efficient method for this task. During the measurements 0.2 μm microfiltration membranes were used and the membrane separation was enhanced by vibration, inserting static mixer and air sparging. The de-fatting efficiency, the retention of the whey components, the flux values, and the resistances in different combinations were compared in this paper

    Knowledge of cervical cancer and attendance at cervical cancer screening: a survey of Black women in London.

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    Women from ethnic minority backgrounds are less likely to attend cervical screening, but further understanding of ethnic inequalities in cervical screening uptake is yet to be established. This study aimed to explore the socio-demographic and ethnicity-related predictors of cervical cancer knowledge, cervical screening attendance and reasons for non-attendance among Black women in London

    Partial refinement of fungal chitinase (Beauveria bassiana) with multistage membrane filtration

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    Microscopic organisms play a vital role in the field of green technology. Among the genera fungi, the group of entomopathogens includes Beauveria bassiana, which has been found to have multifunctional applications. In this present research, we have attempted to partially purify chitinase from two strains of Beauveria bassiana (F881 and F911), each cultured in minimal media with 1% (w/v) colloidal chitin as well as in Sabouraud's dextrose media with 1% (w/v) colloidal chitin. The purification process was done with a setup of ceramic membranes, which comprises two stages, ultrafiltration (50 nm pore size membrane) and nanofiltration (MWCO 5 kDa). Furthermore, with the analysis of yield of enzymatically hydrolyzed NAG (N-acetyl glucosamine), resistance and fouling of the membrane were also studied

    Youth-friendly HIV self-testing: Acceptability of campus-based oral HIV self-testing among young adult students in Zimbabwe.

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    BACKGROUND: Targeted HIV testing strategies are needed to reach remaining undiagnosed people living with HIV and achieve the UNAIDS' 95-95-95 goals for 2030. HIV self-testing (HIVST) can increase uptake of HIV testing among young people, but user perspectives on novel distribution methods are uncertain. We assess the acceptability, perceived challenges, and recommendations of young adult lay counselor-led campus-based HIVST delivery among tertiary school students aged 18-24 years in Zimbabwe. METHODS: We purposively sampled participants from an intervention involving campus-based HIVST using lay workers for distribution. We conducted in-depth interviews (IDIs) and focus group discussions (FGDs) among young adults from 10 universities and colleges in Zimbabwe who: (1) self-tested on campus; (2) self-tested off campus; and (3) opted not to self-test. We audio recorded and transcribed all interviews. Using applied thematic analysis, two investigators identified emergent themes and independently coded transcripts, achieving high inter-coder agreement. RESULTS: Of the 52 young adults (53.8% male, 46.1% female) interviewed through 26 IDIs and four FGDs, most IDI participants (19/26, 73%) favored campus-based HIVST, describing it as a more autonomous, convenient, and socially acceptable experience than other facility or community-based HIV testing services. Despite general acceptability, participants identified challenges with this delivery model, including: perceived social coercion, insufficient privacy and access to post-test counseling. These challenges influenced some participants to opt against self-testing (6/52, 11.5%). Recommendations for improved implementation included integrating secondary distribution of test kits and increased HIV counseling options into campus-based programs. CONCLUSIONS: Barriers to HIV testing among young people are numerous and complex. As the number of new HIV infections among youth continue to grow worldwide, targeted strategies and youth friendly approaches that increase access to testing are needed to close the diagnostic coverage gap. This is the first study to describe young adult acceptance of campus-based delivery of HIVST by lay counselors in Zimbabwe

    Biochemical activities of lactose-derived prebiotics — a review

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    In the dairy industry different types of prebiotics, such galacto-oligosaccharide, lactulose, lactosucrose, tagatose, lactitol, lactobiono- and glucono-δ-lactone are synthesized through different chemical and biochemical reactions (hydrolysis, transgalactosylation, isomerization, fructosyl-transfer, reduction, and oxidation) as well as microbial fermentation processes using raw whey or isolated lactose as feedstock. Lactose-derived prebiotics have several functional and nutritional values. The biochemical activities of lactose-based prebiotics are expressed in the presence of probiotics (lactic acid bacteria, yeasts, Bacillus spp.). Galacto-oligosaccharide and lactosucrose reduce the risk of bowel disorder (diarrhea), inflammatory bowel disease (ulcerative colitis and crohn’s disease), and colon cancer. Galacto-oligosaccharide helps colonic absorption of minerals (iron, magnesium and calcium) and prevents osteoporosis. Lactulose, galacto-oligosaccharide, and lactitol promote laxative activity. Furthermore, lactulose may decrease the risk of hepatic encephalopathy. Prebiotics have low calorific value and glycemic index. Galacto-oligosaccharide and tagatose reduce the risks of hyperglycemia (Type 2 diabetes) and low density lipid (lipoprotein) accumulation in blood stream. Moreover, prebiotics improve immunomodulation, which reduces the risk of respiratory infection and allergies. This review describes unique biochemical mechanisms of several types of lactose-derived prebiotics

    The voice of the student as a ‘consumer’

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    Bunce discusses the impact of students being defined as ‘consumers’ of their higher education. The chapter first considers when and why students came to be defined as consumers in England and Wales, UK, and then reflects upon the advantages and disadvantages associated with treating students as consumers of their education. This discussion includes the perspectives of both students and academic staff, and reviews empirical evidence about the effects of students themselves identifying as consumers on their approaches to learning and academic performance. The chapter concludes with a summary of the challenges for universities when listening to the student as consumer voice and emphasises the importance of striking a balance between making students feel heard, while resisting the notion that ‘the customer is always right’

    Continuous Membrane Emulsification with Pulsed (Oscillatory) Flow

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Industrial and Engineering Chemistry Research, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see: http://dx.doi.org/10.1021/ie3020457Tubular micrometer pore sized sieve type membranes with internal diameter of 14 mm and length of 60 mm containing uniform pores of diameter 10 and 20 μm were used to generate emulsions of sunflower oil dispersed in water and stabilized by Tween 20 using oscillatory flow of the continuous phase. Drop diameters between 30 and 300 μm could be produced, in a controllable way and with span values of down to 0.4. By using pulsed flow it was possible to provide dispersed phase concentrations of up to 45% v/v in a single pass over the membrane, that is, without the need to recirculate the continuous phase through the membrane tube. It was possible to correlate the drop size produced with the shear conditions at the membrane surface using the wave shear stress equation. The oscillatory Reynolds number indicated flow varying from laminar to substantially turbulent, but the change in flow conditions did not show a notable influence on the drop diameters produced, over what is predicted by the varying wall shear stress applied to the wave equation. However, the 20 μm pore sized sieve type membrane appeared to allow the passage of the pressure pulse through the membrane pores, under certain operating conditions, which did lead to finer drop sizes produced than would be predicted. These through-membrane pulsations could be suppressed by changes in operating conditions: a higher dispersed phase injection rate or more viscous continuous phase, and they did not occur under similar operating conditions used with the 10 μm pore sized sieve type of membrane. Generating emulsions of this size using pulsed continuous phase flow provides opportunities for combining drop generation at high dispersed phase concentration, by membrane emulsification, with downstream processing such as reaction in plug flow reactors

    The impact of immediate breast reconstruction on the time to delivery of adjuvant therapy: the iBRA-2 study

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    Background: Immediate breast reconstruction (IBR) is routinely offered to improve quality-of-life for women requiring mastectomy, but there are concerns that more complex surgery may delay adjuvant oncological treatments and compromise long-term outcomes. High-quality evidence is lacking. The iBRA-2 study aimed to investigate the impact of IBR on time to adjuvant therapy. Methods: Consecutive women undergoing mastectomy ± IBR for breast cancer July–December, 2016 were included. Patient demographics, operative, oncological and complication data were collected. Time from last definitive cancer surgery to first adjuvant treatment for patients undergoing mastectomy ± IBR were compared and risk factors associated with delays explored. Results: A total of 2540 patients were recruited from 76 centres; 1008 (39.7%) underwent IBR (implant-only [n = 675, 26.6%]; pedicled flaps [n = 105,4.1%] and free-flaps [n = 228, 8.9%]). Complications requiring re-admission or re-operation were significantly more common in patients undergoing IBR than those receiving mastectomy. Adjuvant chemotherapy or radiotherapy was required by 1235 (48.6%) patients. No clinically significant differences were seen in time to adjuvant therapy between patient groups but major complications irrespective of surgery received were significantly associated with treatment delays. Conclusions: IBR does not result in clinically significant delays to adjuvant therapy, but post-operative complications are associated with treatment delays. Strategies to minimise complications, including careful patient selection, are required to improve outcomes for patients
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