Rotation of a strongly coupled dust cluster in plasma by the torque of an electron beam.

A 1-mm-size cluster composed of 10 dust particles immersed in plasma is rotated by the torque of a pulsed electron beam with energy in the range 8-12 keV. The dust particles are electrically charged spheres with radius 5.9 µm and are levitated in the plasma sheath, forming a round, planar, Coulomb-coupled cluster. The electron beam irradiates the dust cluster passing slightly off its center, and sets the particles in motion by the action of the electron drag force. The total torque at 12 keV is 4.9±0.2×10^{-11} Nm at an angular speed 1.41±0.05 rad s^{-1}. The main dynamical features of the cluster such as intershell rotation and itinerancy of the dust particles inside the cluster are simulated by using a molecular dynamics code.

The influence of socioeconomic status on presentation and outcome of acute kidney injury.

AIM: Although socioeconomic background is known to impact on the incidence and progression of chronic kidney disease, its influence of on the presentation and outcome for acute kidney injury is not known and is the subject of this study. DESIGN: The Welsh National electronic AKI reporting system was used to identify all cases of AKI in patients >18 years of age between March 2015 and November 2017. METHODS: Socioeconomic classification of patients was derived from the Welsh Index Multiple Deprivation score (WIMD). Patients were grouped according to the WIMD score by their postcode, and the ranked data were categorized into percentiles and correlated with incidence and measures of AKI severity and outcome. RESULTS: Date was collected on a total of 57 654 patients. Increased deprivation was associated with higher AKI incidence rates, more episodes of AKI per patient and more severe AKI at presentation. In contrast 90-day mortality was highest in the most affluent areas. Mortality in affluent areas was driven by increased patient age. Corrected for age 90-day mortality was higher in areas of increased deprivation. CONCLUSION: This study highlights that AKI incidence presentation and outcomes are adversely affected by social deprivation. Further studies are required to understand the extent to which these differences reflect patient related factors or regional differences in provision and access to care.

Adding a new dimension to the weekend effect: an analysis of a national data set of electronic AKI alerts.

BACKGROUND: Increased mortality related to differences in delivery of weekend clinical care is the subject of much debate. AIM: We compared mortality following detection of acute kidney injury (AKI) on week and weekend days across community and hospital settings. DESIGN: A prospective national cohort study, with AKI identified using the Welsh National electronic AKI reporting system. METHODS: Data were collected on outcome for all cases of adult AKI in Wales between 1 November 2013 and 31 January 2017. RESULTS: There were a total of 107 298 episodes. Weekday detection of AKI was associated with 28.8% (26 439); 90-day mortality compared to 90-day mortality of 31.9% (4551) for AKI detected on weekdays (RR: 1.11, 95% CI: 1.08-1.14, P < 0.001, HR: 1.16 95% CI: 1.12-1.20, P < 0.001). There was no 'weekend effect' for mortality associated with hospital-acquired AKI. Weekday detection of community-acquired AKI (CA-AKI) was associated with a 22.6% (10 356) mortality compared with weekend detection of CA-AKI, which was associated with a 28.6% (1619) mortality (RR: 1.26, 95% CI: 1.21-1.32, P < 0.001, HR: 1.34, 95%CI: 1.28-1.42, P < 0.001). The excess mortality in weekend CA-AKI was driven by CA-AKI detected at the weekend that was not admitted to hospital compared with CA-AKI detected on weekdays which was admitted to hospital (34.5% vs. 19.1%, RR: 1.8, 95% CI: 1.69-1.91, P < 0.001, HR: 2.03, 95% CI: 1.88-2.19, P < 0.001). CONCLUSION: 'Weekend effect' in AKI relates to access to in-patient care for patients presenting predominantly to hospital emergency departments with AKI at the weekend.

Community acquired acute kidney injury: findings from a large population cohort.

BACKGROUND: The extent of patient contact with medical services prior to development of community acquired-acute kidney injury (CA-AKI)is unknown. AIM: We examined the relationship between incident CA-AKI alerts, previous contact with hospital or primary care and clinical outcomes. DESIGN: A prospective national cohort study of all electronic AKIalerts representing adult CA-AKI. METHODS: Data were collected for all cases of adult (≥18 years of age) CA-AKI in Wales between 1 November 2013 and 31 January 2017. RESULTS: There were a total of 50 560 incident CA-AKI alerts. In 46.8% there was a measurement of renal function in the 30 days prior to the AKI alert. In this group, in 63.8% this was in a hospital setting, of which 37.6% were as an inpatient and 37.5% in Accident and Emergency. Progression of AKI to a higher AKI stage (13.1 vs. 9.8%, P < 0.001) (or for AKI 3 an increase of > 50% from the creatinine value generating the alert), the proportion of patients admitted to Intensive Care (5.5 vs. 4.9%, P = 0.001) and 90-day mortality (27.2 vs. 18.5%, P < 0.001) was significantly higher for patients with a recent test. 90-day mortality was highest for patients with a recent test taken in an inpatient setting prior to CA-AKI (30.9%). CONCLUSION: Almost half of all patients presenting with CA-AKI are already known to medical services, the majority of which have had recent measurement of renal function in a hospital setting, suggesting that AKI for at least some of these may potentially be predictable and/or avoidable.

Acute kidney injury electronic alerts in primary care - findings from a large population cohort.

BACKGROUND: Electronic reporting of AKI has been used to aid early AKI recognition although its relevance to CA-AKI and primary care has not been described. AIMS: We described the characteristics and clinical outcomes of patients with CA-AKI, and AKI identified in primary care (PC-AKI) through AKI e-Alerts. DESIGN: A prospective national cohort study was undertaken to collect data on all e-alerts representing adult CA-AKI. METHOD: The study utilized the biochemistry based AKI electronic (e)-alert system that is established across the Welsh National Health Service. RESULTS: 28.8% of the 22 723 CA-AKI e-alerts were classified as PC-AKI. Ninety-day mortality was 24.0% and lower for PC-AKI vs. non-primary care (non-PC) CA-AKI. Hospitalization was 22.3% for PC-AKI and associated with greater disease severity, higher mortality, but better renal outcomes (non-recovery: 18.1% vs. 21.6%; progression of pre-existing CKD: 40.5% vs. 58.3%). 49.1% of PC-AKI had a repeat test within 7 days, 42.5% between 7 and 90 days, and 8.4% was not repeated within 90 days. There was significantly more non-recovery (24.0% vs. 17.9%) and progression of pre-existing CKD (63.3% vs. 47.0%) in patients with late repeated measurement of renal function compared to those with early repeated measurement of renal function. CONCLUSION: The data demonstrate the clinical utility of AKI e-alerts in primary care. We recommend that a clinical review, or referral together with a repeat measurement of renal function within 7 days should be considered an appropriate response to AKI e-alerts in primary care.

Assessment of perioperative nutrition practices and attitudes-A national survey of colorectal and GI surgical oncology programs.

BACKGROUND: Implementation of evidence-based peri-operative nutrition in the U.S. is poorly described and hypothesized to be suboptimal. This study broadly describes practices and attitudes regarding nutrition screening/intervention in U.S. gastrointestinal and oncologic surgeons. METHODS: Nationwide nutritional practice survey of GI/Oncologic surgical faculty. RESULTS: Program response rates were 57% and 81% for colorectal and oncology fellowships, respectively. Only 38% had formal nutritional screening processes in place. Average estimated percent of patients malnourished, receiving nutritional screening, and receiving nutritional supplementation preoperatively were 28%, 43%, and 21%, respectively. University-affiliation (p = 0.0371) and a formal screening process (p = 0.0312) predicted higher preoperative nutritional screening rates. Controversy existed regarding routine use of perioperative immunonutrition, but strong consensus emerged that lack of awareness regarding positive data for immunonutrition impedes usage. CONCLUSION: U.S. surgeons recognize importance of perioperative nutritional screening and benefits of basic nutrition therapy. However, limited formal nutrition screening programs currently exist indicating a significant need for implementation of nutrition screening and basic nutrition intervention. Further work on education, implementation and identifying clinical research needs for immunonutrition interventions is also vitally needed. SUMMARY: This study broadly describes nutritional practices and attitudes of gastrointestinal and oncologic surgeons across the U.S. Surgeons recognize both the importance of proper perioperative surgical nutritional support and the potential value to their practice in terms of outcomes, but this study confirms poor implementation of evidence-based nutrition practices in GI and oncologic surgery programs. This study describes a significant opportunity to capitalize on current favorable surgeon beliefs (and positive published data) regarding the benefit of perioperative nutrition to improve surgical nutrition practice and patient outcomes in the U.S.

Tunable superomniphobic surfaces for sorting droplets by surface tension.

We utilized tunable superomniphobic surfaces with flower-like TiO2 nanostructures to fabricate a simple device with precisely tailored surface energy domains that, for the first time, can sort droplets by surface tension. We envision that our methodology for droplet sorting will enable inexpensive and energy-efficient analytical devices for personalized point-of-care diagnostic platforms, lab-on-a-chip systems, biochemical assays and biosensors.

A comparative cross-cultural study of the prevalence of late life depression in low and middle income countries.

BACKGROUND: Current estimates of the prevalence of depression in later life mostly arise from studies carried out in Europe, North America and Asia. In this study we aimed to measure the prevalence of depression using a standardised method in a number of low and middle income countries (LMIC). METHODS: A one-phase cross-sectional survey involving over 17,000 participants aged 65 years and over living in urban and rural catchment areas in 13 sites from 9 countries (Cuba, Dominican Republic, Puerto Rico, Mexico, Venezuela, Peru, China, India and Nigeria). Depression was assessed and compared using ICD-10 and EURO-D criteria. RESULTS: Depression prevalence varied across sites according to diagnostic criteria. The lowest prevalence was observed for ICD-10 depressive episode (0.3 to 13.8%). When using the EURO-D depression scale, the prevalence was higher and ranged from 1.0% to 38.6%. The crude prevalence was particularly high in the Dominican Republic and in rural India. ICD-10 depression was also associated with increased age and being female. LIMITATIONS: Generalisability of findings outside of catchment areas is difficult to assess. CONCLUSIONS: Late life depression is burdensome, and common in LMIC. However its prevalence varies from culture to culture; its diagnosis poses a significant challenge and requires proper recognition of its expression.

Time-resolved measurement of global synchronization in the dust acoustic wave.

A spatially and temporally resolved measurement of the synchronization of the naturally occurring dust acoustic wave to an external drive and the relaxation from the driven wave mode back to the naturally occuring wave mode is presented. This measurement provides a time-resolved measurement of the synchronization of the self-excited dust acoustic wave with an external drive and the return to the self-excited mode. It is observed that the wave synchronizes to the external drive in a distinct time-dependent fashion, while there is an immediate loss of synchronization when the external modulation is discontinued.

Evolution of frequency clusters in the naturally occurring dust acoustic wave.

The spatiotemporal evolution of the naturally occurring dust acoustic wave mode is experimentally investigated in a weakly coupled dc glow discharge dusty plasma system over a range of neutral gas pressures through the application of a time-resolved Hilbert Transform. Frequency clusters are observed over a range of neutral gas pressures, though their spatial distribution varies with neutral gas pressure. It is also observed that the wave frequency is observed to drop by ∼ 10 Hz across these frequency clusters independent of the experimental parameters.

Dynamical (e,2e) studies of tetrahydropyran and 1,4-dioxane.

We present experimental and theoretical results for the electron-impact ionization of the highest occupied molecular orbitals of tetrahydropyran and 1,4-dioxane. Using an (e,2e) technique in asymmetric coplanar kinematics, angular distributions of the slow ejected electron, with an energy of 20 eV, are measured when incident electrons at 250 eV ionize the target and scatter through an angle of either -10° or -15°. The data are compared with calculations performed at the molecular 3-body distorted wave level. Fair agreement between the theoretical model and the experimental measurements was observed. The similar structures for these targets provide key insights for assessing the limitations of the theoretical calculations. This study in turn facilitates an improved understanding of the dynamics in the ionization process.

A dynamical (e,2e) investigation of the structurally related cyclic ethers tetrahydrofuran, tetrahydropyran, and 1,4-dioxane.

Triple differential cross section measurements for the electron-impact ionization of the highest occupied molecular orbitals of tetrahydropyran and 1,4-dioxane are presented. For each molecule, experimental measurements were performed using the (e,2e) technique in asymmetric coplanar kinematics with an incident electron energy of 250 eV and an ejected electron energy of 20 eV. With the scattered electrons being detected at -5°, the angular distributions of the ejected electrons in the binary and recoil regions were observed. These measurements are compared with calculations performed within the molecular 3-body distorted wave model. Here, reasonable agreement was observed between the theoretical model and the experimental measurements. These measurements are compared with results from a recent study on tetrahydrofuran [D. B. Jones, J. D. Builth-Williams, S. M. Bellm, L. Chiari, C. G. Ning, H. Chaluvadi, B. Lohmann, O. Ingolfsson, D. Madison, and M. J. Brunger, Chem. Phys. Lett. 572, 32 (2013)] in order to evaluate the influence of structure on the dynamics of the ionization process across this series of cyclic ethers.

Kinetics of the melting front in two-dimensional plasma crystals: Complementary analysis with the particle image and particle tracking velocimetries.

Melting of a two-dimensional plasma crystal occurring due to a mode-coupling instability is studied using particle tracking and particle image velocimetry techniques. By combining these techniques, it is possible to identify the location of a propagating melting front and find a characteristic scale length for the temperature gradient across the front. It is found that the measurements of heat transport are consistent with a simple two-dimensional model allowing us to estimate the thermal diffusivity. The measured values for the thermal diffusivity are consistent with previously measured values.

Dynamical (e,2e) studies of tetrahydrofurfuryl alcohol.

Cross section data for electron scattering from DNA are important for modelling radiation damage in biological systems. Triply differential cross sections for the electron impact ionization of the highest occupied outer valence orbital of tetrahydrofurfuryl alcohol, which can be considered as an analogue to the deoxyribose backbone molecule in DNA, have been measured using the (e,2e) technique. The measurements have been performed with coplanar asymmetric kinematics at an incident electron energy of 250 eV, an ejected electron energy of 20 eV, and at scattered electron angles of -5°, -10°, and -15°. Experimental results are compared with corresponding theoretical calculations performed using the molecular 3-body distorted wave model. Some important differences are observed between the experiment and calculations.

Experimental and theoretical investigation of the triple differential cross section for electron impact ionization of pyrimidine molecules.

Cross-section data for electron impact induced ionization of bio-molecules are important for modelling the deposition of energy within a biological medium and for gaining knowledge of electron driven processes at the molecular level. Triply differential cross sections have been measured for the electron impact ionization of the outer valence 7b(2) and 10a(1) orbitals of pyrimidine, using the (e, 2e) technique. The measurements have been performed with coplanar asymmetric kinematics, at an incident electron energy of 250 eV and ejected electron energy of 20 eV, for scattered electron angles of -5°, -10°, and -15°. The ejected electron angular range encompasses both the binary and recoil peaks in the triple differential cross section. Corresponding theoretical calculations have been performed using the molecular 3-body distorted wave model and are in reasonably good agreement with the present experiment.

Folate in skin cancer prevention.

Skin, the largest, most exposed organ of the body, provides a protective interface between humans and the environment. One of its primary roles is protection against exposure to sunlight, a major source of skin damage where the UV radiation (UVR) component functions as a complete carcinogen. Melanin pigmentation and the evolution of dark skin is an adaptive protective mechanism against high levels of UVR exposure. Recently, the hypothesis that skin pigmentation balances folate preservation and Vitamin D production has emerged. Both micronutrients are essential for reproductive success. Photodegradation of bioactive folates suggests a mechanism for the increased tendency of populations of low melanin pigmentation residing in areas of high UV exposure to develop skin cancers. Folate is proposed as a cancer prevention target for its role in providing precursors for DNA repair and replication, as well as its ability to promote genomic integrity through the generation of methyl groups needed for control of gene expression. The cancer prevention potential of folate has been demonstrated by large-scale epidemiological and nutritional studies indicating that decreased folate status increases the risk of developing certain cancers. While folate deficiency has been extensively documented by analysis of human plasma, folate status within skin has not been widely investigated. Nevertheless, inefficient delivery of micronutrients to skin and photolysis of folate argue that documented folate deficiencies will be present if not exacerbated in skin. Our studies indicate a critical role for folate in skin and the potential to protect sun exposed skin by effective topical delivery as a strategy for cancer prevention.

A brief dementia screener suitable for use by non-specialists in resource poor settings--the cross-cultural derivation and validation of the brief Community Screening Instrument for Dementia.

OBJECTIVE: Brief screening tools for dementia for use by non-specialists in primary care have yet to be validated in non-western settings where cultural factors and limited education may complicate the task. We aimed to derive a brief version of cognitive and informant scales from the Community Screening Instrument for Dementia (CSI-D) and to carry out initial assessments of their likely validity. METHODS: We applied Mokken analysis to CSI-D cognitive and informant scale data from 15 022 participants in representative population-based surveys in Latin America, India and China, to identify a subset of items from each that conformed optimally to item response theory scaling principles. The validity coefficients of the resulting brief scales (area under ROC curve, optimal cutpoint, sensitivity, specificity and Youden's index) were estimated from data collected in a previous cross-cultural validation of the full CSI-D. RESULTS: Seven cognitive items (Loevinger H coefficient 0.64) and six informant items (Loevinger H coefficient 0.69) were selected with excellent hierarchical scaling properties. For the brief cognitive scale, AUROC varied between 0.88 and 0.97, for the brief informant scale between 0.92 and 1.00, and for the combined algorithm between 0.94 and 1.00. Optimal cutpoints did not vary between regions. Youden's index for the combined algorithm varied between 0.78 and 1.00 by region. CONCLUSION: A brief version of the full CSI-D appears to share the favourable culture- and education-fair screening properties of the full assessment, despite considerable abbreviation. The feasibility and validity of the brief version still needs to be established in routine primary care.

An epidemic of furniture-related dermatitis: searching for a cause.

Background Sitting in new chairs or sofas has elicited dermatitis in numerous patients in Finland and in the U.K. since autumn 2006. The cause of the dermatitis seemed to be an allergen in the furniture materials. Objectives To determine the cause of the dermatitis in patients with furniture-related dermatitis. Methods Altogether 42 patients with furniture-related dermatitis were studied. First, 14 Finnish patients were patch tested with the standardized series and with the chair textile material. A thin-layer chromatogram (TLC) strip and an extract made from the same textile material were tested in seven Finnish patients. The test positive spot of the TLC and the content of a sachet found inside a sofa in the U.K. were analysed by using gas chromatography-mass spectrometry. All chemicals analysed were patch tested in 37 patients. Results A positive patch test reaction to the chair textile and to its extract was seen in all patients tested, one-third of whom had concurrent reactions to acrylates. Positive reactions to the same spot of the TLC strip were seen in five of seven patients and dimethyl fumarate was analysed from the spot as well as from the sachet contents. Dimethyl fumarate (0.01%) elicited positive reactions in all the patients. The other chemicals analysed did not elicit positive reactions, but one patient in the U.K. had a positive reaction to tributyl phosphate. Conclusions Sensitization to dimethyl fumarate was seen in all the patients with furniture-related dermatitis. Concurrent sensitization or cross-reactions were common among the sensitized patients.