A Predictive Model for Convective Flows Induced by Surface Reactivity Contrast

Concentration gradients in a fluid along a reactive surface due to contrast in surface reactivity generate convective flows. These flows result from contributions by electro and diffusio osmotic phenomena. In this study we have analyzed reactive patterns that release and consume protons, analogous to bimetallic catalytic conversion of peroxide. Here, we present a simple analytical model that accurately predicts the induced potentials and consequent velocities in such systems over a wide range of input parameters. Our model is tested against direct numerical solutions to the coupled Poisson, Nernst-Planck, and Navier-Stokes equations. Our analysis can be used to predict enhancement of mass transport and the resulting impact on overall catalytic conversion, and is also applicable to predicting the speed of catalytic nanomotors

Oral bioaccessibility tests to measure potentially toxic elements in inhalable particulate matter collected during routine air quality monitoring

The simplified bioaccessibility extraction test (SBET) and the stomach phase of the unified bioaccessibility method (UBM) have been modified for use in assessing the bioaccessibility of potentially toxic elements in samples of PM10 collected during routine air quality monitoring. Arsenic, Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured by inductively coupled plasma mass spectrometry in extracts of synthetic PM samples prepared by loading candidate soil reference material BGS102 onto TX40 (Teflon-coated borosilicate) filters widely used in standard commercial tapered element oscillating microbalance/filter dynamics measurement system (FDMS) ambient particulate monitors. Analysis of blanks revealed two important sources of contamination that had to be controlled in order to achieve reproducible results. The syringe filters used in the SBET released Cu and Zn into sample extracts during filtration and had to be washed with 80 mL of 0.4 M glycine at pH 1.5 immediately prior to use, whilst the FDMS filters used to collect PM10 were found to contain sufficient extractable Zn (ca. 3 μg per filter) to almost double the concentration released by the soil. The latter is a consequence of the use of Zn in filter manufacture and so could not be eliminated, but was successfully overcome by means of blank-subtraction. A ten-fold miniaturisation of the SBET and six-fold miniaturisation of the UBM allowed 0.1 g samples to be processed, with analyte recoveries generally within ±10% of those obtained when the conventional procedures were used. Comparison between results obtained when the modified procedures were applied to soil alone, and when soil was loaded onto FDMS filters, indicated that the presence of the filter had no effect on extraction efficiency, except for Fe, provided blank-correction was performed. Results obtained for As, Cd and Pb when the modified UBM was applied to BGS102 on FDMS filters were 4.40 ± 0.04, 0.224 ± 0.002 and 17.3 ± 0.8 mg kg-1, respectively (n = 3), all within recommended ranges

A novel two-step sequential bioaccessibility test for potentially toxic elements in inhaled particulate matter transported into the gastrointestinal tract by mucociliary clearance

A novel two-step sequential extraction has been developed to assess the bioaccessibility of As, Cd, Cr, Cu, Fe, Mn, Ni, Pb, and Zn in airborne particulate matter following inhalation and transport into the human gastrointestinal tract by mucociliary clearance. A new artificial mucus fluid (AMF) was used to determine the bioaccessible potentially toxic element (PTE) fraction in the upper airways, in sequence with the simplified bioaccessibility extraction test (SBET) or the stomach phase of the unified bioaccessibility method (gastric fluid only) (UBMG). Filter dynamic measurement system TX40 filters smeared with soil reference material (BGS RM 102) were used as test samples. Analysis was performed by ICP-MS. Comparison between results obtained for soil alone and when the soil was supported on TX40 filters indicated that the presence of the substrate did not affect the extraction efficiency, although a large Zn blank was detected. The sequential AMF→SBET extraction liberated similar amounts of Fe, Mn, Ni and Zn to the SBET alone; but significantly less Cd; and significantly more As, Cr, Cu and Pb. The sequential AMF→UBMG extraction liberated similar amounts of Cd, Cr, Mn and Zn to the UBMG alone, but significantly less As, Fe and Ni; and significantly more Cu and Pb. Enhanced extractability was due to the greater quantities of exchangeable ions and complexing agents present. Adoption of a two-step sequential extraction (AMF followed by either the SBET or the UBMG) is recommended because it is more representative of biological conditions and avoids overestimation or underestimation of bioaccessible PTE concentrations

Efficacy and safety of more intensive lowering of LDL cholesterol: a meta-analysis of data from 170 000 participants in 26 randomised trials

Background: Lowering of LDL cholesterol with standard statin regimens reduces the risk of occlusive vascular events in a wide range of individuals. We aimed to assess the safety and efficacy of more intensive lowering of LDL cholesterol with statin therapy. Methods: We undertook meta-analyses of individual participant data from randomised trials involving at least 1000 participants and at least 2 years' treatment duration of more versus less intensive statin regimens (five trials; 39 612 individuals; median follow-up 5·1 years) and of statin versus control (21 trials; 129 526 individuals; median follow-up 4·8 years). For each type of trial, we calculated not only the average risk reduction, but also the average risk reduction per 1·0 mmol/L LDL cholesterol reduction at 1 year after randomisation. Findings: In the trials of more versus less intensive statin therapy, the weighted mean further reduction in LDL cholesterol at 1 year was 0·51 mmol/L. Compared with less intensive regimens, more intensive regimens produced a highly significant 15% (95% CI 11–18; p<0·0001) further reduction in major vascular events, consisting of separately significant reductions in coronary death or non-fatal myocardial infarction of 13% (95% CI 7–19; p<0·0001), in coronary revascularisation of 19% (95% CI 15–24; p<0·0001), and in ischaemic stroke of 16% (95% CI 5–26; p=0·005). Per 1·0 mmol/L reduction in LDL cholesterol, these further reductions in risk were similar to the proportional reductions in the trials of statin versus control. When both types of trial were combined, similar proportional reductions in major vascular events per 1·0 mmol/L LDL cholesterol reduction were found in all types of patient studied (rate ratio [RR] 0·78, 95% CI 0·76–0·80; p<0·0001), including those with LDL cholesterol lower than 2 mmol/L on the less intensive or control regimen. Across all 26 trials, all-cause mortality was reduced by 10% per 1·0 mmol/L LDL reduction (RR 0·90, 95% CI 0·87–0·93; p<0·0001), largely reflecting significant reductions in deaths due to coronary heart disease (RR 0·80, 99% CI 0·74–0·87; p<0·0001) and other cardiac causes (RR 0·89, 99% CI 0·81–0·98; p=0·002), with no significant effect on deaths due to stroke (RR 0·96, 95% CI 0·84–1·09; p=0·5) or other vascular causes (RR 0·98, 99% CI 0·81–1·18; p=0·8). No significant effects were observed on deaths due to cancer or other non-vascular causes (RR 0·97, 95% CI 0·92–1·03; p=0·3) or on cancer incidence (RR 1·00, 95% CI 0·96–1·04; p=0·9), even at low LDL cholesterol concentrations. Interpretation: Further reductions in LDL cholesterol safely produce definite further reductions in the incidence of heart attack, of revascularisation, and of ischaemic stroke, with each 1·0 mmol/L reduction reducing the annual rate of these major vascular events by just over a fifth. There was no evidence of any threshold within the cholesterol range studied, suggesting that reduction of LDL cholesterol by 2–3 mmol/L would reduce risk by about 40–50%

Densitas Gizi dan Morbiditas Serta Hubungannya dengan Status Gizi Anak Usia Prasekolah Pedesaan

Usia prasekolah merupakan periode golden age yang rentan terhadap penyakit infeksi sehingga harus diperhatikan pemenuhan gizinya agar dapat tumbuh kembang secara optimal. Tujuan penelitian ini adalah untuk mengkaji densitas zat gizi dan energi pangan, densitas asupan zat gizi dan energi, morbiditas, serta hubungannya dengan status gizi BB/U, TB/U, dan BB/TB pada anak usia prasekolah di daerah pedesaan. Penelitian ini menggunakan data Improving Child Growth and Development through Nutrition and Psychosocial Intervention in Early Childhood Education (PAUD) Setting in Rural Areas berkerja sama dengan Nestle Foundation (NF) Switzerland. Desain penelitian ini adalah cross-sectional study melibatkan 120 anak usia prasekolah usia 4-6 tahun. Lokasi dan subjek dipilih secara purposive dilakukan di Kecamatan Tamansari dan Kecamatan Dramaga, Kabupaten Bogor. Studi ini menemukan bahwa sebagian besar subjek memiliki status gizi yang baik. Densitas gizi pangan anak usia prasekolah pedesaan rendah kualitas zat gizinya. Densitas asupan zat gizi mikro ditemukan rendah tetapi tinggi densitas asupan energi. Lebih dari setengah subjek dengan tingkat morbiditas tinggi. Densitas asupan energi signifikan berhubungan dengan status gizi BB/U dan BB/TB (p<0.05). Densitas asupan protein signifikan berhubungan dengan status gizi BB/U dan TB/U (p<0.05). Morbiditas tidak signifikan berhubungan dengan status gizi