Real-time monitoring of proton exchange membrane fuel cell stack failure

Uneven pressure drops in a 75-cell 9.5-kWe proton exchange membrane fuel cell stack with a U-shaped flow configuration have been shown to cause localised flooding. Condensed water then leads to localised cell heating, resulting in reduced membrane durability. Upon purging of the anode manifold, the resulting mechanical strain on the membrane can lead to the formation of a pin-hole/membrane crack and a rapid decrease in open circuit voltage due to gas crossover. This failure has the potential to cascade to neighbouring cells due to the bipolar plate coupling and the current density heterogeneities arising from the pin-hole/membrane crack. Reintroduction of hydrogen after failure results in cell voltage loss propagating from the pin-hole/membrane crack location due to reactant crossover from the anode to the cathode, given that the anode pressure is higher than the cathode pressure. Through these observations, it is recommended that purging is avoided when the onset of flooding is observed to prevent irreparable damage to the stack

Precipitate stability and recrystallisation in the weld nuggets of friction stir welded Al-Mg-Si and Al-Mg-Sc alloys

Two different precipitate hardening aluminium alloys processed by friction stir welding were investigated. The microstructure and the hardness of the as delivered materials were compared to that of the weld nugget. Transmission electron microscopy observations combined with three-dimensional atom probe analyses clearly show that \beta;" precipitates dissolved in the nugget of the Al-Mg-Si giving rise to some supersaturated solid solution. It is shown that the dramatic softening of the weld could be partly recovered by post-welding ageing treatments. In the Al-Mg-Sc alloy, Al3Sc precipitate size and density are unchanged in the nugget comparing to the base metal. These precipitates strongly reduce the boundary mobility of recrystallised grains, leading to a grain size in the nugget much smaller than in the Al-Mg-Si alloy. Both coherent and incoherent precipitates were detected. This feature may indicate that a combination of continuous and discontinuous recrystallisation occurred in the weld nugget

Electronic Medical Record Cancer Incidence over Six Years Comparing New Users of Glargine with New Users of NPH Insulin

Background: Recent studies suggested that insulin glargine use could be associated with increased risk of cancer. We compared the incidence of cancer in new users of glargine versus new users of NPH in a longitudinal clinical cohort with diabetes for up to 6 years. Methods and Findings: From all patients who had been regularly followed at Massachusetts General Hospital from 1/01/2005 to 12/31/2010, 3,680 patients who had a medication record for glargine or NPH usage were obtained from the electronic medical record (EMR). From those we selected 539 new glargine users (age: 60.1±13.6 years, BMI: 32.7±7.5 kg/m2) and 343 new NPH users (61.5±14.1 years, 32.7±8.3 kg/m2) who had no prevalent cancer during 19 months prior to glargine or NPH initiation. All incident cancer cases were ascertained from the EMR requiring at least 2 ICD-9 codes within a 2 month period. Insulin exposure time and cumulative dose were validated. The statistical analysis compared the rates of cancer in new glargine vs. new NPH users while on treatment, adjusted for the propensity to receive one or the other insulin. There were 26 and 28 new cancer cases in new glargine and new NPH users for 1559 and 1126 person-years follow-up, respectively. There were no differences in the propensity-adjusted clinical characteristics between groups. The adjusted hazard ratio for the cancer incidence comparing glargine vs. NPH use was 0.65 (95% CI: 0.36–1.19). Conclusions: Insulin glargine is not associated with development of cancers when compared with NPH in this longitudinal and carefully retrieved EMR data

The effect of deworming on growth in one-year-old children living in a soil-transmitted helminth-endemic area of Peru: a randomized controlled trial

BACKGROUND:Appropriate health and nutrition interventions to prevent long-term adverse effects in children are necessary before two years of age. One such intervention may include population-based deworming, recommended as of 12 months of age by the World Health Organization in soil-transmitted helminth (STH)-endemic areas; however, the benefit of deworming has been understudied in early preschool-age children. METHODOLOGY/PRINCIPAL FINDINGS:A randomized, double-blind, placebo-controlled trial was conducted to determine the effect of deworming (500 mg single-dose crushed mebendazole tablet) on growth in one-year-old children in Iquitos, Peru. Children were enrolled during their routine 12-month growth and development clinic visit and followed up at their 18 and 24-month visits. Children were randomly allocated to: Group 1: deworming at 12 months and placebo at 18 months; Group 2: placebo at 12 months and deworming at 18 months; Group 3: deworming at both 12 and 18 months; or Group 4: placebo at both 12 and 18 months (i.e. control group). The primary outcome was weight gain at the 24-month visit. An intention-to-treat approach was used. A total of 1760 children were enrolled between September 2011 and June 2012. Follow-up of 1563 children (88.8%) was completed by July 2013. STH infection was of low prevalence and predominantly light intensity in the study population. All groups gained between 1.93 and 2.05 kg on average over 12 months; the average difference in weight gain (kg) compared to placebo was: 0.05 (95% CI: -0.05, 0.17) in Group 1; -0.07 (95%CI: -0.17, 0.04) in Group 2; and 0.04 (95%CI: -0.06, 0.14) in Group 3. There was no statistically significant difference in weight gain in any of the deworming intervention groups compared to the control group. CONCLUSIONS:Overall, with one year of follow-up, no effect of deworming on growth could be detected in this population of preschool-age children. Low baseline STH prevalence and intensity and/or access to deworming drugs outside of the trial may have diluted the potential effect of the intervention. Additional research is required to overcome these challenges and to contribute to strengthening the evidence base on deworming. TRIAL REGISTRATION:ClinicalTrials.gov (NCT01314937)

Echinococcus multilocularis infection in solid organ transplant recipients

Alveolar echinococcosis (AE) is a zoonosis caused by the ingestion of eggs of the tapeworm Echinococcus multilocularis, causing a severe infection most often localized in the liver. Its behavior is similar to that of a malignant tumor as it invades surrounding tissues and can metastasize to distant organs. If left untreated, the mortality of AE can be as high as 90% after 10 years. In the immunosuppressed host, a higher incidence of AE has been reported. Additionally, AE seems to have a faster evolution, with more severe manifestations. However, there are very few data on the epidemiology and clinical manifestations of AE specifically in solid-organ transplant (SOT) recipients. In this multicentric case series, we retrospectively collected de novo cases of AE in SOT recipients by searching the STCS database in Switzerland and the FrancEchino registry in France for cases from 01/2008 to 08/2018. We collected data about the clinical presentation, diagnosis, treatment and outcome at each center using a standardized collection form. A total of 7 patients were identified (kidney=5, heart=1, lung=1), 5 in France and 2 in Switzerland. Six patients presented with liver AE and one with lung AE. AE was asymptomatic at diagnosis in 4 patients and presented with abdominal pain in 2 of them. One had undocumented symptoms. The median time between transplantation and diagnosis was 66 months (ranging from 12 to 240). Two patients had no liver lesions 26 and 43 months prior to diagnosis, respectively. Diagnosis was done by serology in all cases (Western-blot was positive in all 7 cases, Em2+ was positive in 1/3, hydatic fluid antigen ELISA in 4/4 and indirect hemagglutination in 3/3). Imaging was atypical in 2 cases, with a pseudo-tumoral appearance in one case. Biopsies confirmed AE in 3 cases but led to an erroneous diagnosis in one case. Four of the 7 patients were operated (all incomplete resections) and 2 died following the operation. Albendazole was started in all surviving patients and was well tolerated by all patients (tolerance undocumented in one case). AE remained stable in 3 of the 5 cases and progressed in 1 case. The evolution is undocumented in one case. One patient died of cause unrelated to AE. The incidence of AE seems to be higher and its evolution faster in SOT recipients than in the general population. Our data also suggest that diagnosis of AE in this population is more challenging, with atypical imaging and sometimes misleading biopsies. In this series, post-operative mortality was high, perhaps suggesting that a more conservative approach is needed in this immunocompromised population

Cancer Incidence Among Those Initiating Insulin Therapy With Glargine Versus Human NPH Insulin

OBJECTIVE To add to the evidence on comparative long-term effects of insulin analog glargine versus human NPH insulin on the risk for cancer. RESEARCH DESIGN AND METHODS We identified cohorts of initiators of glargine and human NPH without an insulin prescription during the prior 19 months among patients covered by the Inovalon Medical Outcomes Research for Effectiveness and Economics Registry (MORE2 Registry) between January 2003 and December 2010. Patients were required to have a second prescription of the same insulin within 180 days and to be free of cancer. We balanced cohorts on risk factors for cancer outcomes based on comorbidities, comedication, and health care use during the prior 12 months using inverse probability of treatment weighting. Incident cancer was defined as having two claims for cancer (any cancer) or the same cancer (breast, prostate, colon) within 2 months. We estimated adjusted hazard ratios (HRs) and their 95% CI using weighted Cox models censoring for stopping, switching, or augmenting insulin treatment, end of enrollment, and mortality. RESULTS More patients initiated glargine (43,306) than NPH (9,147). Initiators of glargine (NPH) were followed for 1.2 (1.1) years and 50,548 (10,011) person-years; 993 (178) developed cancer. The overall HR was 1.12 (95% CI 0.95–1.32). Results were consistent for breast cancer, prostate cancer, and colon cancer; various durations of treatment; and sensitivity analyses. CONCLUSIONS Patients initiating insulin glargine rather than NPH do not seem to be at an increased risk for cancer. While our study contributes significantly to our evidence base for long-term effects, this evidence is very limited mainly based on actual dynamics in insulin prescribing

Can majority support save an endangered language? A case study of language attitudes in Guernsey

Many studies of minority language revitalisation focus on the attitudes and perceptions of minorities, but not on those of majority group members. This paper discusses the implications of these issues, and presents research into majority andf minority attitudes towards the endangered indigenous vernacular of Guernsey, Channel Islands. The research used a multi-method approach (questionnaire and interview) to obtain attitudinal data from a representative sample of the population that included politicians and civil servants (209 participants). The findings suggested a shift in language ideology away from the post-second world war ‘culture of modernisation’ and monolingual ideal, towards recognition of the value of a bi/trilingual linguistic heritage. Public opinion in Guernsey now seems to support the maintenance of the indigenous language variety, which has led to a degree of official support. The paper then discusses to what extent this ‘attitude shift’ is reflected in linguistic behaviour and in concrete language planning measures

DNS of the kappa-mechanism. I. Radial modes in the purely radiative case

Context: Hydrodynamical model of the kappa-mechanism in a purely radiative case. Aims: First, to determine the physical conditions propitious to kappa-mechanism in a layer with a configurable conductivity hollow and second, to perform the (nonlinear) direct numerical simulations (DNS) from the most favourable setups. Methods: A linear stability analysis applied to radial modes using a spectral solver and DNS thanks to a high-order finite difference code are compared. Results: Changing the hollow properties (location and shape) lead to well-defined instability strips. For a given position in the layer, the amplitude and width of the hollow appear to be the key parameters to get unstable modes driven by kappa-mechanism. The DNS achieved from these more auspicious configurations confirm the growth rates as well as structures of linearly unstable modes. The nonlinear saturation follows through intricate couplings between the excited fundamental mode and higher damped overtones.Comment: 15 pages, 15 figures, 1 table, accepted for publication in A&

Multi-Periodic Oscillations in Cepheids and RR Lyrae-Type Stars

Classical Cepheids and RR Lyrae-type stars are usually considered to be textbook examples of purely radial, strictly periodic pulsators. Not all the variables, however, conform to this simple picture. In this review I discuss different forms of multi-periodicity observed in Cepheids and RR Lyrae stars, including Blazhko effect and various types of radial and nonradial multi-mode oscillations.Comment: Proceedings of the 20th Stellar Pulsation Conference Series: "Impact of new instrumentation & new insights in stellar pulsations", 5-9 September 2011, Granada, Spai

Recoil following Wiktor stent implantation for restenotic lesions of coronary arteries

The purpose of this study was to determine acute recoil of the vessel wall immediately after Wiktor stent implantation in native coronary arteries of 77 consecutive patients and to assess whether there was compression or “late recoil” of the stent itself at long-term follow-up. Furthermore, the relationship between recoil and a number of clinical, angiographic, and procedural variables was studied in addition to the relation between acute recoil renarrowing or restenosis was assessed. All angiograms were analyzed with the Cardiovascular Angiography Analysis System using automated edge detection. Acute recoil was defined by the difference between the mean diameter of the fully expanded balloon on which the stent was mounted and the mean diameter of the stented segment. Late recoil was calculated by comparing the mean diameter of the stent itself immediately after implantation and at follow-up without opacification of the vessel. Acute recoil amounted to 0.25 ± 0.32 mm or 8.2%. Multivariate analysis identified sex (coefficient = –0.20, p = 0.04) and stent/artery ratio (coefficient = 0.99, p = 0.0001) as the only independent predictors of acute recoil. “Late recoil” of the stent itself was not observed. The overall difference between the mean diameter of the stent itself immediately after implantation and at follow-up was –0.15 ± 0.33 mm, suggesting an overall increase in diameter of 5.0%. There was no relation between acute recoil and late restenosis. On the contrary, there was a trend towards a greater degree of recoil in patients without restenosis. Moreover, linear regression analysis disclosed a weak but negative correlation between acute recoil and a loss in minimal luminal diameter (coefficient: –0.55, p = 0.04). The Wiktor stent effectively scaffolds the instrumented vessel. Only a minimal amount of acute recoil was noted, which did not contribute to late luminal renarrowing or restenosis. In addition, no late compression of the stent itself was observed. These data suggest that tissue ingrowth into the lumen of the stented segment is the main cause of late luminal renarrowing after stent implantation. © 1994 Wiley-Liss,Inc.