799 research outputs found
A novel description of ISFET sensitivity with the buffer capacity and double-layer capacitance as key parameters
The pH sensitivity of ISFETs arises from interactions of protons with ISFET gate surface sites. This sensitivity is described by a new simpler model with the intrinsic buffer capacity and the differential capacitance as key parameters. The obtained expression is independent of the models used for the chemical surface equilibria and the charge profile in the solution. The general expression for the sensitivity is elaborated using the site-binding theory and the Gouy-Chapman-Stern theory. The relatively high sensitivity of Ta2O5 ISFETs is explained using this elaborated theory. It is shown that the electrolyte concentration has almost no influence on the sensitivity of Ta2O5 ISFETs
Ik zie, ik zie, wat jij niet ziet. Het gebruik van paragnosten door de Nederlandse politie.
Abstract In many police investigations a psychic turns up to help the investigation with his extraordinary knowledge of the crime and the crime scene. Little is known about how the Dutch police deals with psychics and their information. We conducted research into this phenomenon via interviews with experts, a review of the legal literature and an online questionnaire for police practitioners. Although a guideline by the public prosecutor’s office state psychics are not to be consulted without permission, most police practitioners are not aware of this guideline. At the moment little is known about the actual use of information of psychics in police investigations
Processing of marula (Sclerocarya birrea subsp. Caffra) fruits : a case study on health-promoting compounds in marula pulp
Marula is a multipurpose tree from Southern Africa, used by local people for its fruit, and cosmetic oil from the seed and for medicinal products from the bark and leaves. Fruits are eaten raw, or used to prepare juices, jams, conserves, dry fruit rolls, or fermented to make alcoholic beverages like beer, wine and Amarula. The fruit is a vital source of vitamin C for rural people most of whom cannot afford other more expensive sources of vitamin C. The specific processing methods and conditions of making marula juice vary among different regions. This thesis investigated the fate of antioxidants, i.e. vitamin C, and their activities due to heat processing and fermentation of the marula pulps and its juices. The results showed that marula fruit pulp has a vitamin C content higher than that of most fruits, ranging from 62 mg/100 g fresh weight– to over 400 mg/100 g. Juice production was optimized by an experimental design combined with response surface modelling: adding pectinase (in the range of 0.1 to 0.14%) increased the yield of marula juice by 23%. The optimal extraction temperature for the content of vitamin C and polyphenols as well as for the antioxidant activity ranged between 40 and 60°C. At heating temperatures below 125ºC, ascorbic acid in marula pulp was about 15-fold more stable than in mango and guava pulp. The results further revealed that marula peel contained more volatile compounds (75) including all the identified volatiles (41) of the flesh. Marula fruit is a rich source of vitamin C and other antioxidants. The use of unfermented juice should be encouraged since it can contribute to the energy intake of the marula juice drinkers. Marula juice is a rich source of natural antioxidants. In addition, marula processors are advised to incorporate (part of) the skin in products such as juices, jams, jellies and alcoholic beverages during processing to enhance the unique characteristic marula flavor in the products which are currently claimed not to have a strong marula like flavour.</p
Systematic review and meta-analysis of vancomycin-induced nephrotoxicity associated with dosing schedules that maintain troughs between 15 and 20 milligrams per liter
In an effort to maximize outcomes, recent expert guidelines recommend more-intensive vancomycin dosing schedules to maintain vancomycin troughs between 15 and 20 mg/liter.The widespread use of these more-intensive regimens has been associated with an increase in vancomycin-induced nephrotoxicity reports.The purpose of this systematic literature review is to determine the nephrotoxicity potential of maintaining higher troughs in clinical practice.All studies pertaining to vancomycin-induced nephrotoxicity between 1996 and April 2012 were identified from PubMed, Embase, Cochrane Controlled Trial Registry, and Medline databases and analyzed according to Cochrane guidelines.Of the initial 240 studies identified, 38 were reviewed, and 15 studies met the inclusion criteria.Overall, higher troughs ( >15 mg/liter) were associated with increased odds of nephrotoxicity (odds ratio [OR], 2.67; 95% confidence interval [CI], 1.95 to 3.65) relative to lower troughs of >15 mg/liter.The relationship between a trough of >15 mg/liter and nephrotoxicity persisted when the analysis was restricted to studies that examined only initial trough concentrations (OR, 3.12; 95% CI, 1.81 to 5.37).The relationship between troughs of >15 mg/liter and nephrotoxicity persisted after adjustment for covariates known to independently increase the risk of a nephrotoxicity event.An incremental increase in nephrotoxicity was also observed with longer durations of vancomycin administration.Vancomycin-induced nephrotoxicity was reversible in the majority of cases, with short-term dialysis required only in 3% of nephrotoxic episodes.The collective literature indicates that an exposure-nephrotoxicity relationship for vancomycin exists.The probability of a nephrotoxic event increased as a function of the trough concentration and duration of therapy
N deposition and elevated CO2 on methane emissions: Differential responses of indirect effects compared to direct effects through litter chemistry feedbacks
Increases in atmospheric CO2 concentration and N deposition are expected to affect methane (CH4) production in soils and emission to the atmosphere, directly through increased plant litter production and indirectly through changes in substrate quality. We examined how CH4 emission responded to changes in litter quality under increased N and CO2, beyond differences in CH4 resulting from changes in litter production. We used senesced leaves from 13C-labeled plants of Molinia caerulea grown at elevated and ambient CO2 and affected by N fertilization to carry out two experiments: a laboratory litter incubation and a pot experiment. N fertilization increased N and decreased C concentrations in litter whereas elevated CO2 decreased litter quality as reflected in litter C and N concentrations and in the composition of lignin and saturated fatty acids within the litter. In contrast to our expectations, CH4 production in the laboratory incubation decreased when using litter from N-fertilized plants as substrate, whereas litter from elevated CO2 had no effect, compared to controls without N and at ambient CO2. Owing to high within-treatment variability in CH4 emissions, none of the treatment effects were reflected in the pot experiment. C mineralization rates were not affected by any of the treatments. The decrease in CH4 emissions due to indirect effects of N availability through litter quality changes (described here for the first time) contrast direct effects of N fertilization on CH4 production. The complex interaction of direct effects with indirect effects of increased N on litter quality may potentially result in a net decrease in CH4 emissions from wetlands in the long term.Fil: Pancotto, Veronica Andrea. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Centro Austral de Investigaciones CientÃficas; ArgentinaFil: Bodegom, P. M. van. University Of Amsterdam; PaÃses BajosFil: Hal, J. van. University Of Amsterdam; PaÃses BajosFil: Logtestijn, R. S. P. van. University Of Amsterdam; PaÃses BajosFil: Blokker, P.. University Of Amsterdam; PaÃses BajosFil: Toet, S.. University Of Amsterdam; PaÃses Bajos. University Of York; Reino UnidoFil: Aerts, R.. University Of Amsterdam; PaÃses Bajo
Knowledge deficit and fear of COVID-19 among higher education students during the first wave of the pandemic and implications for public health: a multi-country cross-sectional survey
Coverage determinants of breast cancer screening in Flanders:an evaluation of the past decade
Background Breast cancer (BC) is the most common cancer in women in the developed world. In order to find developing cancers in an early stage, BC screening is commonly used. In Flanders, screening is performed in and outside an organized breast cancer screening program (BCSP). However, the determinants of BC screening coverage for both screening strategies are yet unknown. Objective To assess the determinants of BC screening coverage in Flanders. Methods Reimbursement data were used to attribute a screening status to each woman in the target population for the years 2008-2016. Yearly coverage data were categorized as screening inside or outside BCSP or no screening. Data were clustered by municipality level. A generalized linear equation model was used to assess the determinants of screening type. Results Over all years and municipalities, the median screening coverage rate inside and outside BCSP was 48.40% (IQR: 41.50-54.40%) and 14.10% (IQR: 9.80-19.80%) respectively. A higher coverage rate outside BSCP was statistically significantly (P < 0.001) associated with more crowded households (OR: 3.797, 95% CI: 3.199-4.508), younger age, higher population densities (OR: 2.528, 95% CI: 2.455-2.606), a lower proportion of unemployed job seekers (OR: 0.641, 95% CI: 0.624-0.658) and lower use of dental care (OR: 0.969, 95% CI: 0.967-0.972). Conclusion Coverage rate of BC screening is not optimal in Flanders. Women with low SES that are characterized by younger age, living in a high population density area, living in crowded households, or having low dental care are less likely to be screened for BC in Flanders. If screened, they are more likely to be screened outside the BCSP
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