How polymer additives reduce the pour point of hydrocarbon solvents containing wax crystals

We have investigated how four different pour point depressant (PPD) polymers affect the pour point transition in mixtures of a single pure wax in a solvent. We used either n-eicosane (C20), CH3(CH2)18CH3, n-tetracosane (C24), CH3(CH2)22CH3 or n-hexatriacontane (C36), CH3(CH2)34CH3 as the wax component with either n-heptane or toluene as the solvent component. For all wax–solvent combinations, the measured variation of wax solubility with temperature is well predicted by ideal solution theory. The variation of pour point temperature as a function of the overall wax concentration is quantitatively modelled using the idea that, for each overall wax concentration, the pour point occurs at a temperature at which a critical volume fraction ϕ* of wax crystals has precipitated. Close to the pour point temperature, extraction and examination of the wax crystals show they consist of polydisperse, irregularly-shaped platelets with axial ratios (h/d, where h is the plate thickness and d is the plate long dimension) in the range 0.005–0.05. It is found that the measured ϕ* values corresponding to the pour point transitions are weakly correlated with the wax crystal axial ratios (h/d) for all wax–solvent–PPD polymer combinations. These results indicate that the pour point transition occurs at a volume fraction larger than the value at which the volumes of rotation of the platelet crystals overlap, i.e., 2.5(h/d) < ϕ* < 11(h/d). PPD polymers work, in part, by increasing the wax crystal axial ratio (h/d), thereby increasing ϕ* and reducing the pour point temperature. Since the PPD's ability to modify the wax crystal shape relies on its adsorption to the crystal-solution surface, it is anticipated and observed experimentally that optimum PPD efficacy is correlated with the difference between the wax and the polymer solubility boundary temperatures. This finding and the mechanistic insight gained here provide the basis for a simple and rapid screening test to identify candidate species likely to be effective PPDs for particular wax systems

Depleting Depletion: Maintaining Single-Walled Carbon Nanotube Dispersions after Graft-to Polymer Functionalization

Grafting polymers onto single-walled carbon nanotubes (SWCNTs) usefully alters properties but does not typically yield stable, solvated species directly. Despite the expectation of steric stabilization, a damaging (re)dispersion step is usually necessary. Here, poly(vinyl acetate)s (PVAc) of varying molecular weights are grafted to individualized, reduced SWCNTs at different concentrations to examine the extent of reaction and degree of solvation. The use of higher polymer concentrations leads to an increase in grafting ratio (weight fraction of grafted polymer relative to the SWCNT framework), approaching the limit of random sequentially adsorbed Flory ‘mushrooms’ on the surface. However, at higher polymer concentrations, a larger percentage of SWCNTs precipitate during the reaction; an effect which is more significant for larger weight polymers. The precipitation is attributed to depletion interactions generated by ungrafted homopolymer overcoming Coulombic repulsion of adjacent like-charged SWCNTs; a simple model is proposed. Larger polymers and greater degrees of functionalization favor stable solvation, but larger and more concentrated homopolymers increase depletion aggregation. By using low concentrations (25 μM) of larger molecular weight PVAc (10 kDa), up to 65% of grafted SWCNTs were retained in solution (at 65 μg mL-1) directly after the reaction

Practice nurse-supported weight self-management delivered within the national child immunisation programme for postnatal women:a feasibility cluster RCT

Background: Pregnancy is a high-risk time for excessive weight gain. The rising prevalence of obesity in women, combined with excess weight gain during pregnancy, means that there are more women with obesity in the postnatal period. This can have adverse health consequences for women in later life and increases the health risks during subsequent pregnancies. Objective: The primary aim was to produce evidence of whether or not a Phase III trial of a brief weight management intervention, in which postnatal women are encouraged by practice nurses as part of the national child immunisation programme to self-monitor their weight and use an online weight management programme, is feasible and acceptable. Design: The research involved a cluster randomised controlled feasibility trial and two semistructured interview studies with intervention participants and practice nurses who delivered the intervention. Trial data were collected at baseline and 3 months later. The interview studies took place after trial follow-up. Setting: The trial took place in Birmingham, UK. Participants: Twenty-eight postnatal women who were overweight/obese were recruited via Birmingham Women’s Hospital or general practices. Nine intervention participants and seven nurses were interviewed. Interventions: The intervention was delivered in the context of the national child immunisation programme. The intervention group were offered brief support that encouraged self-management of weight when they attended their practice to have their child immunised at 2, 3 and 4 months of age. The intervention involved the provision of motivation and support by nurses to encourage participants to make healthier lifestyle choices through self-monitoring of weight and signposting to an online weight management programme. The role of the nurse was to provide regular external accountability for weight loss. Women were asked to weigh themselves weekly and record this on a record card in their child’s health record (‘red book’) or using the online programme. The behavioural goal was for women to lose 0.5-1 kg per week. The usual-care group received a healthy lifestyle leaflet. Main outcome measures: The primary outcome was the feasibility of a Phase III trial to test the effectiveness of the intervention, as assessed against three traffic-light stop-go criteria (recruitment, adherence to regular self-weighing and registration with an online weight management programme). Results: The traffic-light criteria results were red for recruitment (28/80, 35% of target), amber for registration with the online weight loss programme (9/16, 56%) and green for adherence to weekly self-weighing (10/16, 63%). Nurses delivered the intervention with high fidelity. In the qualitative studies, participants indicated that the intervention was acceptable to them and they welcomed receiving support to lose weight at their child immunisation appointments. Although nurses raised some caveats to implementation, they felt that the intervention was easy to deliver and that it would motivate postnatal women to lose weight. Limitations: Fewer participants were recruited than planned. Conclusions: Although women and practice nurses responded well to the intervention and adherence to self-weighing was high, recruitment was challenging and there is scope to improve engagement with the intervention.Future work: Future research should focus on investigating other methods of recruitment and, thereafter, testing the effectiveness of the intervention.Trial registration: Current Controlled Trials ISRCTN12209332.Funding: This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 25, No. 49. See the NIHR Journals Library website for further project information.</p

Blood pressure monitoring in high-risk pregnancy to improve the detection and monitoring of hypertension (the BUMP 1 and 2 trials): protocol for two linked randomised controlled trials.

INTRODUCTION: Self-monitoring of blood pressure (BP) in pregnancy could improve the detection and management of pregnancy hypertension, while also empowering and engaging women in their own care. Two linked trials aim to evaluate whether BP self-monitoring in pregnancy improves the detection of raised BP during higher risk pregnancies (BUMP 1) and whether self-monitoring reduces systolic BP during hypertensive pregnancy (BUMP 2). METHODS AND ANALYSES: Both are multicentre, non-masked, parallel group, randomised controlled trials. Participants will be randomised to self-monitoring with telemonitoring or usual care. BUMP 1 will recruit a minimum of 2262 pregnant women at higher risk of pregnancy hypertension and BUMP 2 will recruit a minimum of 512 pregnant women with either gestational or chronic hypertension. The BUMP 1 primary outcome is the time to the first recording of raised BP by a healthcare professional. The BUMP 2 primary outcome is mean systolic BP between baseline and delivery recorded by healthcare professionals. Other outcomes will include maternal and perinatal outcomes, quality of life and adverse events. An economic evaluation of BP self-monitoring in addition to usual care compared with usual care alone will be assessed across both study populations within trial and with modelling to estimate long-term cost-effectiveness. A linked process evaluation will combine quantitative and qualitative data to examine how BP self-monitoring in pregnancy is implemented and accepted in both daily life and routine clinical practice. ETHICS AND DISSEMINATION: The trials have been approved by a Research Ethics Committee (17/WM/0241) and relevant research authorities. They will be published in peer-reviewed journals and presented at national and international conferences. If shown to be effective, BP self-monitoring would be applicable to a large population of pregnant women. TRIAL REGISTRATION NUMBER: NCT03334149.This work is funded from a National Institute for Health Research (NIHR) Programme grant for applied research (RP-PG- 1209-10051) and an NIHR Professorship awarded to RJM (NIHR-RP- R2- 12-015). RJM and KLT receive funding from the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care Oxford at Oxford Health NHS Foundation Trust. JS is a National Institute for Health Research (NIHR) Senior Investigator and supported by the National Institute for Health Research (NIHR) Collaboration for Leadership in Applied Health Research and Care South London (NIHR CLAHRC South London) at King’s College Hospital NHS Foundation Trust. Service support costs will be administered through the NIHR Clinical Research Network

Independence of Sexual and Anti-Predator Perceptual Functions in an Acoustic Moth: Implications for the Receiver Bias Mechanism in Signal Evolution

International audienceThe receiver bias model for the evolution of mating signals proposes that selection favors male displays that happen to stimulate a general, ancestral perception in females such that receptivity and successful courtship increase. If these male signals do arise, however, the female perception will operate in two contexts, the original, typically non-sexual, one and courtship. We may then ask whether these two functions represent the same or distinct traits, which may be under separate neural and genetic control. We studied this question in Achroia grisella, a pyralid moth species in which males attract females, with an ultrasonic mating song. Hearing in pyralid moths is widespread and originated in an anti-predator context – the perception and avoidance of echolocating bats – and it is inferred that the male song found in A. grisella, and in several other pyralid species, arose subsequently via a receiver bias mechanism: Females perceiving male-produced ultrasound and responding with anti-predator behavior normally exhibited in the presence of bat echolocations may have inadvertently increased the likelihood of successful courtship. We measured hearing responses in both sexual and anti-predator contexts in inbred lines developed from an A. grisella population. Significant inter-line variance was observed for sensitivity thresholds for female response to male song and for both female and male responses to synthetic bat echolocation signals. Female responses to male song and to synthetic echolocations differed markedly in sensitivity, and the median sexual and anti-predator responses in the various lines were not correlated. However, a higher level of similarity occurs between the female and male anti-predator responses. Thus, genetic variance for sexual and anti-predator responses appears to exist, and the two responses may represent independent traits. These results imply that when male signals originate via a receiver bias mechanism, female perception does not necessarily remain fixed in its ancestral state but has the potential for continued modification

An infant femur bearing cut marks from Roman Hambleden, England

A perinatal infant skeleton from the first–fourth century AD Roman villa site at Hambleden, England, shows what appear to be cut marks on the proximal part of the right femur. Gross, microscopic and micro-computed tomography evaluations suggest that they occurred perimortem and were probably caused by a non-serrated blade. The reason for the cuts is uncertain, but their location is consistent with the practice of embryotomy, as described in classical sources for obstructed labour due to a dead or dying foetus in a breech or leg presentation. If this interpretation is correct, this case represents a rare example of embryotomy in the palaeopathological record

Complementary and alternative medicine (CAM) use among non-Hispanic white, Mexican American, and Vietnamese American patients with type 2 diabetes.

PurposeThis study examines the use of complementary and alternative medicine (CAM) by ethnicity/race among patients with type 2 diabetes.Subjects and methodsFour hundred and ten (410) patients with type 2 diabetes recruited from an academic-medical center completed a survey assessing CAM use, diabetes status, and sociodemographic characteristics.ResultsSeveral significant ethnic/racial differences were observed in CAM use (both in the types of providers seen as well as in the herbs and dietary supplements used). Although White patients reported using CAM in addition to their diabetes medication (mean [SD] 4.9 [0.4] on a scale from 1=never to 5=always) more frequently than Mexican American patients (3.1 [1.6], p&lt;.05), Mexican American patients (1.4 [1.1]) used CAM instead of their diabetes medications more frequently than non-Hispanic White patients (1.0 [0.1], p&lt;.05). More Mexican American (66.7%) and Vietnamese American patients (73.7%) than non-Hispanic Whites (11.8%, p=.002) described CAM practitioners as being closer to their cultural traditions than Western practitioners, whereas Vietnamese [End Page 1941] patients were more likely to describe use of herbs and supplements as closer to their cultural traditions (84.5% versus 15.3% for White and 30.9% for Mexican American patients, p &lt;.001).ConclusionsConsidering the variability and perceptions in CAM use, providers should discuss with their patients how their CAM use may influence diabetes management behaviors

Complementary and Alternative Medicine (CAM) Use among Non-Hispanic White, Mexican American, and Vietnamese American Patients with Type 2 Diabetes

PurposeThis study examines the use of complementary and alternative medicine (CAM) by ethnicity/race among patients with type 2 diabetes.Subjects and methodsFour hundred and ten (410) patients with type 2 diabetes recruited from an academic-medical center completed a survey assessing CAM use, diabetes status, and sociodemographic characteristics.ResultsSeveral significant ethnic/racial differences were observed in CAM use (both in the types of providers seen as well as in the herbs and dietary supplements used). Although White patients reported using CAM in addition to their diabetes medication (mean [SD] 4.9 [0.4] on a scale from 1=never to 5=always) more frequently than Mexican American patients (3.1 [1.6], p&lt;.05), Mexican American patients (1.4 [1.1]) used CAM instead of their diabetes medications more frequently than non-Hispanic White patients (1.0 [0.1], p&lt;.05). More Mexican American (66.7%) and Vietnamese American patients (73.7%) than non-Hispanic Whites (11.8%, p=.002) described CAM practitioners as being closer to their cultural traditions than Western practitioners, whereas Vietnamese [End Page 1941] patients were more likely to describe use of herbs and supplements as closer to their cultural traditions (84.5% versus 15.3% for White and 30.9% for Mexican American patients, p &lt;.001).ConclusionsConsidering the variability and perceptions in CAM use, providers should discuss with their patients how their CAM use may influence diabetes management behaviors