Potassium, Calcium, and Magnesium Bridging of AOT to Mica at Constant Ionic Strength.

The bridging effect of a series of common cations between the anionic mica surface and the AOT anion has been studied in a condition of constant ionic strength and surfactant concentration. It was found that sodium ions did not show any bridging effect in this system; however, calcium, magnesium, and potassium all caused adsorption of the organic to the mica surface. The concentrations at which bridging occurred was probed, revealing that only a very low bridging cation concentration was required for binding. The bridged layer stability was also investigated, and the interaction was shown to be a weak one, with the bound layer in equilibrium with the species in the bulk and easily removed. Even maintaining ionic strength and bridging ion concentration was not sufficient to retain the layer when the free organic in solution was removed.We thank EPSRC and BP plc for the funding (RG8620) that made this work possible

Advances in Nondietary Management of Children with Atopic Dermatitis

This paper discusses recent advances in therapy of atopic dermatitis (AD), excluding those that include dietary management. Some of these therapies are anecdotal, experimental, or somewhat controversial. It is important to emphasize that physicians should not try what is new without first having given standard therapy a long and reasonable chance to succeed. This is important because AD does not last forever, and in many patients, mild disease heals spontaneously.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72467/1/j.1525-1470.1989.tb00820.x.pd

Sampling Effort and Uncertainty in Leaf Litterfall Mass and Nutrient Flux in Northern Hardwood Forests

Designs for litterfall sampling can be improved by understanding the sources of uncertainty in litterfall mass and nutrient concentration. We compared the coefficient of variation of leaf litterfall mass and nutrient concentrations (nitrogen, phosphorus, calcium, magnesium, and potassium) at different spatial scales and across years for six northern hardwood species from 23 stands in the White Mountains of New Hampshire, USA. Stands with steeper slopes (P = 0.01), higher elevations (P = 0.05), and more westerly aspect (P = 0.002) had higher interannual variation in litter mass, probably due to a litter trap design that allowed litter to blow into traps in windy years. The spatial variation of nutrient concentrations varied more across stands than within stands for all elements (P \u3c 0.001). Phosphorus was the most spatially variable of all nutrients across stands (P \u3c 0.001). Litter nutrient concentrations varied less from year to year than litter mass, but the magnitude of difference depended on the element and tree species. We compared the relative importance of variation in mass vs. concentration to estimates of nutrient flux by simulating different sampling intensities of one while holding the other constant. In this dataset, interannual variability of leaf litter mass contributed more to uncertainty in litterfall flux calculations than interannual variation in nutrient concentrations. Optimal sampling schemes will depend on the elements of interest and local factors affecting spatial and temporal variability

Engineering tyrosine residues into hemoglobin enhances heme reduction, decreases oxidative stress and increases vascular retention of a hemoglobin based blood substitute

Hemoglobin (Hb)-based oxygen carriers (HBOC) are modified extracellular proteins, designed to replace or augment the oxygen-carrying capacity of erythrocytes. However, clinical results have generally been disappointing due to adverse side effects, in part linked to the intrinsic oxidative toxicity of Hb. Previously a redox-active tyrosine residue was engineered into the Hb β subunit (βF41Y) to facilitate electron transfer between endogenous antioxidants such as ascorbate and the oxidative ferryl heme species, converting the highly oxidizing ferryl species into the less reactive ferric (met) form. We inserted different single tyrosine mutations into the α and β subunits of Hb to determine if this effect of βF41Y was unique. Every mutation that was inserted within electron transfer range of the protein surface and the heme increased the rate of ferryl reduction. However, surprisingly, three of the mutations (βT84Y, αL91Y and βF85Y) also increased the rate of ascorbate reduction of ferric(met) Hb to ferrous(oxy) Hb. The rate enhancement was most evident at ascorbate concentrations equivalent to that found in plasma (< 100 μM), suggesting that it might be of benefit in decreasing oxidative stress in vivo. The most promising mutant (βT84Y) was stable with no increase in autoxidation or heme loss. A decrease in membrane damage following Hb addition to HEK cells correlated with the ability of βT84Y to maintain the protein in its oxygenated form. When PEGylated and injected into mice, βT84Y was shown to have an increased vascular half time compared to wild type PEGylated Hb. βT84Y represents a new class of mutations with the ability to enhance reduction of both ferryl and ferric Hb, and thus has potential to decrease adverse side effects as one component of a final HBOC product

Bariatric-metabolic surgery for NHS patients with type 2 diabetes in the United Kingdom National Bariatric Surgery Registry

Aim: Bariatric-metabolic surgery is approved by the National Institute of Health and Care Excellence (NICE) for people with severe obesity and type 2 diabetes (T2DM) (including class 1 obesity after 2014). This study analysed baseline characteristics, disease severity and operations undertaken in people with obesity and T2DM undergoing bariatric-metabolic surgery in the UK National Health Service (NHS) compared to those without T2DM. Methods: Baseline characteristics, trends over time and operations undertaken were analysed for people undergoing primary bariatric-metabolic surgery in the NHS using the National Bariatric Surgical Registry (NBSR) for 11 years from 2009 to 2019. Clinical practice before and after the publication of the NICE guidance (2014) was examined. Multivariate logistic regression was used to determine associations with T2DM status and the procedure undertaken. Results: 14,948/51,715 (28.9%) participants had T2DM, with 10,626 (71.1%) on oral hypoglycaemics, 4322 (28.9%) on insulin/other injectables, and with T2DM diagnosed 10+ years before surgery in 3876 (25.9%). Participants with T2DM, compared to those without T2DM, were associated with older age (p &lt; 0.001), male sex (p &lt; 0.001), poorer functional status (p &lt; 0.001), dyslipidaemia (OR: 3.58 (CI: 3.39–3.79); p &lt; 0.001), hypertension (OR: 2.32 (2.19–2.45); p &lt; 0.001) and liver disease (OR: 1.73 (1.58–1.90); p &lt; 0.001), but no difference in body mass index was noted. Fewer people receiving bariatric-metabolic surgery after 2015 had T2DM (p &lt; 0.001), although a very small percentage increase of those with class I obesity and T2DM was noted. Gastric bypass was the commonest operation overall. T2DM status was associated with selection for gastric bypass compared to sleeve gastrectomy (p &lt; 0.001). Conclusion: NHS bariatric-metabolic surgery is used for people with T2DM much later in the disease process when it is less effective. National guidance on bariatric-metabolic surgery and data from multiple RCTs have had little impact on clinical practice.</p

A Core Outcome Set for the Benefits and Adverse Events of Bariatric and Metabolic Surgery:the BARIACT project

BackgroundBariatric and metabolic surgery is used as a treatment for patients with severe and complex obesity. However, there is a need to improve outcome selection and reporting in bariatric surgery trials. A Core Outcome Set (COS), an agreed minimum set of outcomes reported in all studies of a specific condition, may achieve this. Here, we present the development of a COS for BARIAtric and metabolic surgery Clinical Trials-the BARIACT Study.Methods and findingsOutcomes identified from systematic reviews and patient interviews informed a questionnaire survey. Patients and health professionals were surveyed three times and asked to rate the importance of each item on a 1-9 scale. Delphi methods provided anonymised feedback to participants. Items not meeting predefined criteria were discarded between rounds. Remaining items were discussed at consensus meetings, held separately with patients and professionals, where the COS was agreed. Data sources identified 2,990 outcomes, which were used to develop a 130-item questionnaire. Round 1 response rates were moderate but subsequently improved to above 75% for other rounds. After rounds 2 and 3, 81 and 14 items were discarded, respectively, leaving 35 items for discussion at consensus meetings. The final COS included nine items: "weight," "diabetes status," "cardiovascular risk," "overall quality of life (QOL)," "mortality," "technical complications of the specific operation," "any re-operation/re-intervention," "dysphagia/regurgitation," and "micronutrient status." The main limitation of this study was that it was based in the United Kingdom only.ConclusionsThe COS is recommended to be used as a minimum in all trials of bariatric and metabolic surgery. Adoption of the COS will improve data synthesis and the value of research data. Future work will establish methods for the measurement of the outcomes in the COS

Towards a neutron and X-ray reflectometry environment for the study of solid–liquid interfaces under shear

Funder: Infineum UK LtdAbstract: A novel neutron and X-ray reflectometry sample environment is presented for the study of surface-active molecules at solid–liquid interfaces under shear. Neutron reflectometry was successfully used to characterise the iron oxide–dodecane interface at a shear rate of 7.0×102s-1 using a combination of conventional reflectometry theory coupled with the summation of reflected intensities to describe reflectivity from thicker films. Additionally, the structure adopted by glycerol monooleate (GMO), an Organic Friction Modifier, when adsorbed at the iron oxide–dodecane interface at a shear rate of 7.0×102s-1 was studied. It was found that GMO forms a surface layer that appears unaltered by the effect of shear, where the thickness of the GMO layer was found to be 24.3-10.2+9.9 Å under direct shear at 7.0×102s-1 and 25.8-5.2+4.4 Å when not directly under shear. Finally, a model to analyse X-ray reflectometry data collected with the sample environment is also described and applied to data collected at 3.0×103s-1

HD-PTP Is a Catalytically Inactive Tyrosine Phosphatase Due to a Conserved Divergence in Its Phosphatase Domain

The HD-PTP protein has been described as a tumor suppressor candidate and based on its amino acid sequence, categorized as a classical non-transmembrane protein tyrosine phosphatase (PTP). To date, no HD-PTP phosphorylated substrate has been identified and controversial results concerning its catalytic activity have been recently reported

Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy

Background A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets. Methods Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis. Results A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001). Conclusion We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty