Determination of the internal piezoelectric potentials and indium concentration in InGaN based quantum wells grown on relaxed InGaN pseudo-substrates by off-axis electron holography.

Micro light emitting diodes have been grown by metal organic vapor phase epitaxy on standard GaN and partly relaxed InGaNOS substrates with the purpose of incorporating higher concentrations of indium for identical growth conditions. Green emission has been demonstrated at wavelengths of 500 nm for the GaN template and 525 and 549 nm for the InGaNOS substrates, respectively. The structure, deformation, indium concentration and piezoelectric potentials have been measured with nm-scale spatial resolution in the same specimens by transmission electron microscopy. We show by off-axis electron holography that the piezoelectric potential and information about the indium concentration from the mean inner potential are obtained simultaneously. By separating the components using a model, we show that for higher concentrations of indium in the quantum wells (QWs) grown on InGaNOS substrates, the piezoelectric potentials are reduced. The measurements of the indium concentrations by electron holography have been verified by combining energy dispersive x-ray spectrometry, x-ray diffraction and from the tensile deformation made by precession electron diffraction. A discussion of the limitations of these advanced aberration-corrected transmission electron microscopy techniques when applied to nm-scale QW structures is given.

Initiation of forward gait with lateral occurrence of emotional stimuli: general findings and relevance for pedestrians crossing roads.

With reference to theoretical models regarding links between emotions and actions, the present study examined whether the lateral occurrence of an emotional stimulus influences spatial and temporal parameters of gait initiation in 18 younger and 18 older healthy adults. In order to simulate road-crossing hazard for pedestrians, slides of approaching cars were used and they were presented in counterbalanced order with threatening slides from the International Affective Picture System (IAPS) and control slides of safe walking areas. Each slide was presented on the left side of the participant once the first step was initiated. The results evidenced medio-lateral shifts to the left for the first step (right foot) and to the right for the second step (left foot). These shifts were both modulated by the slide contents in such a way that the resulting distance between the screen and the foot (right or left) was larger with the IAPS and traffic slides than with the control slides. The slides did not affect the base of support, step length, step velocity and time of double support. Advancing age influenced the subjective impact of the slides and gait characteristics, but did not modulate medio-lateral shifts. The data extend evidence of fast, emotional modulation of stepping, with theoretical and applied consequences.

Enhanced precision of ankle torque measure with an open-unit dynamometer mounted with a 3D force-torque sensor.

PURPOSE: Many studies have focused on maximum torque exerted by ankle joint muscles during plantar flexion. While strength parameters are typically measured with isokinetic or isolated ankle dynamometers, these devices often present substantial limitations for the measurement of torque because they account for force in only 1 dimension (1D), and the device often constrains the body in a position that augments torque through counter movements. The purposes of this study were to determine the contribution of body position to ankle plantar-flexion torque and to assess the use of 1D and 3D torque sensors. METHODS: A custom designed 'Booted, Open-Unit, Three dimension, Transportable, Ergometer' (B.O.T.T.E.) was used to quantify plantar flexion in two conditions: (1) when the participant was restrained within the unit (locked-unit) and (2) when the participant's position was independent of the ankle dynamometer (open-unit). Ten young males performed maximal voluntary isometric plantar-flexion contractions using the B.O.T.T.E. in open and locked-unit mechanical configurations. RESULTS: The B.O.T.T.E. was reliable with ICC higher than 0.90, and CV lower than 7 %. The plantar-flexion maximal resultant torque was significantly higher in the locked-unit compared with open-unit configuration (P < 0.001; +61 to +157 %) due to the addition of forces from the body being constrained within the testing device. A 1D compared with 3D torque sensor significantly underestimated the proper capacity of plantar-flexion torque production (P < 0.001; -37 to -60 %). CONCLUSIONS: Assessment of plantar-flexion torque should be performed with an open-unit dynamometer mounted with a 3D sensor that is exclusive of accessory muscles but inclusive of all ankle joint movements.

The "Swiss Statement": who knows about it? How do they know? What are its effects on people living with HIV/AIDS?

The publication of the "Swiss Statement" in 2008 shook the international HIV prevention and advocacy scene. HIV behavioral research has provided us with some studies focusing on the potential changes that new prevention strategies can produce, but results are not conclusive. Besides, there is a lack of data concerning awareness of these kinds of prevention strategies on real-life settings, studying mainly the behavior of people recruited in different types of trials (e.g., circumcision, pre and post-exposure prophylaxis). The present study aims to (1) identify the factors associated with awareness of the "Swiss Statement" among PLWHA, (2) determine in which setting they became aware of it, and (3) look for potential, behavioral, and/or emotional changes as a consequence of this awareness. In order to achieve these three objectives, we used the data collected by a community-based survey called "HIV, Hepatitis and you." In order to determine the factors associated with the awareness of the Swiss Statement, univariate and multivariate logistic regression were performed. Main results show that among the 997 HIV-positive people answering the questionnaire, 57% knew about the Swiss Statement, and that their main source of information was the associative setting, while 30% declared having found out about it from their doctor. As for the factors associated with the awareness of the Swiss Statement, we found that the following variables were significantly associated with such awareness: living in stable housing, having a CD4 count above 350 cell/mm(3), having an undetectable viral load, being in contact with a HIV-solidarity network, feeling of belonging to the LGBT community, and filling out the questionnaire online. The results of this study point out that interventions addressed to improve access to health-related information for PLWHA facing socioeconomical difficulties and isolation are strongly needed.

Genesis of a KPC-producing Klebsiella pneumoniae after in vivo transfer from an imported Greek strain.

We document here the in vivo transfer of bla(KPC-2) between intensive care unit-acquired and a commensal strain of K. pneumoniae in a French patient after his repatriation from Greece. This first report of an emerging KPC-producing strain in France raises further concerns about the spread of carbapenem resistance among Enterobacteriaceae.

Simplification and first validation of a short battery of patient questionnaires for clinical management of HIV-infected patients: The HIV-SQUAD (Symptom Quality of life Adherence) Questionnaire.

PURPOSE: Questionnaires assessing patient-reported outcomes in HIV are either too long or not HIV-specific. Our aim was to develop and validate a simplified HIV patient questionnaire. METHOD: 607 HIV patients treated with a combination of antiretroviral (ARV) drugs were enrolled in an observational, longitudinal study. Questionnaires covering health-related quality of life (HRQoL), satisfaction, tolerability, and adherence were administered at baseline (BL) and Month 3 (M3). The items were selected according to their content and discriminant properties. The simplified questionnaire was then administered at Month 12 (M12). Psychometric properties of physical wellbeing, psychological well-being, and global HRQoL scores were assessed. RESULTS: The simplified questionnaire included 12 HRQoL items, 13 side-effects items, and one visual analog scale (VAS) measuring adherence. The principal component analysis (PCA) confirmed the validity of the global HRQoL score. The multivariate analysis showed acceptable-to-good internal consistency of the three scores. Convergent and discriminant validity were excellent for the physical score. The global score showed significant differences according to time since diagnosis, hepatitis coinfection, CD4 count, and viral load. CONCLUSION: This questionnaire deals with the major aspects of HIV patient perceptions. The global HRQoL score is well correlated to the surrogate markers of HIV. Such a questionnaire may represent a new tool for the therapeutic management of HIV-infected patients. Further steps are required to complete these results.

The impact of dam flushing event on dissolved trace elements concentrations: Coupling integrative passive sampling and discrete monitoring.

Sediments accumulation in reservoirs induces water storage capacities reduction and flood risks increases rendering dam flushing or dredging events compulsory for security reasons. Short transient events like dam flushing monitoring is still a great challenge because the suspended sediments and contaminants concentrations increases could occur over only few hours/days and cover tens of kilometres. Since 1942, 21 dam flushing events have been performed on the Upper Rhône River (from Lake Geneva in Switzerland to Lyon in France) in order to evacuate accumulated sediments behind the Verbois dam (Switzerland). We designed an original sampling strategy to assess the 2016 dam flushing event consequences on the spatio-temporal dynamics of dissolved trace elements concentration and to reveal how passive sampling monitoring (Diffusive Gradient in Thin films, DGT) could improve this evaluation. Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd, Pb, As and Hg dissolved concentrations were monitored by discrete and passive sampling at 3 stations over 160 km downstream the Verbois dam. Since dissolved Fe, Cu, Cd, Cr, Pb, Zn and Hg concentrations did not show great variations during the flushing event, the DGT efficiency was not fully demonstrated for these elements. In contrast, a sharp increase of Mn, Ni, Co and As dissolved concentrations (up to 22 times) was recorded, resulting mainly from a release from resuspended sediment. The dissolved As increase was mainly caused by reduced arsenic (AsIII) increase, even monitored 160 km downstream the Verbois dam. The DGT measurements were highly representative of trace elements concentrations and As speciation dynamics in comparison with discrete sampling. Although relatively high dispersion was highlighted for some elements DGT measurements during the flushing event, we showed that DGTs are robust and powerful time-integrative tools to monitor many trace elements more efficiently than discrete sampling during a short transient event on a large spatial scale.

Correction to: Functional outcomes in adult patients with herpes simplex encephalitis admitted to the ICU: a multicenter cohort study.

The original article unfortunately contained a mistake. Due to technical problems the study group was not tagged correctly. Please find the correct tagging down below. We apologize for the mistake.

Functional outcomes in adult patients with herpes simplex encephalitis admitted to the ICU: a multicenter cohort study.

PURPOSE: We aimed to study the association of body temperature and other admission factors with outcomes of herpes simplex encephalitis (HSE) adult patients requiring ICU admission. METHODS: We conducted a retrospective multicenter study on patients diagnosed with HSE in 47 ICUs in France, between 2007 and 2017. Fever was defined as a body temperature higher or equal to 38.3 °C. Multivariate logistic regression analysis was used to identify factors associated with poor outcome at 90 days, defined by a score of 3-6 (indicating moderate-to-severe disability or death) on the modified Rankin scale. RESULTS: Overall, 259 patients with a score on the Glasgow coma scale of 9 (6-12) and a body temperature of 38.7 (38.1-39.2) °C at admission were studied. At 90 days, 185 (71%) patients had a poor outcome, including 44 (17%) deaths. After adjusting for age, fever (OR = 2.21; 95% CI 1.18-4.16), mechanical ventilation (OR = 2.21; 95% CI 1.21-4.03), and MRI brain lesions > 3 lobes (OR = 3.04; 95% CI 1.35-6.81) were independently associated with poor outcome. By contrast, a direct ICU admission, as compared to initial admission to the hospital wards (i.e., indirect ICU admission), was protective (OR = 0.52; 95% CI 0.28-0.95). Sensitivity analyses performed after adjustment for functional status before admission and reason for ICU admission yielded similar results. CONCLUSIONS: In HSE adult patients requiring ICU admission, several admission factors are associated with an increased risk of poor functional outcome. The identification of potentially modifiable factors, namely, elevated admission body temperature and indirect ICU admission, provides an opportunity for testing further intervention strategies.

Cessation of screening for intestinal carriage of extended-spectrum ß-lactamase-producing Enterobacteriaceae in a low-endemicity intensive care unit with universal contact precautions.

OBJECTIVES: The usefulness of screening for carriage of extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL-E) with active surveillance cultures (ASC) remains equivocal in low-endemicity intensive care units (ICUs). Our primary objective was to appraise the impact of ceasing ASC on the incidence of ICU-acquired ESBL-E infections in an ICU with universal contact precautions (CP). Patient outcomes and carbapenem consumption were also investigated. METHODS: A single-ICU, retrospective, uncontrolled before-and-after study including all patients admitted for ≥3 days during two consecutive 1-year periods with and without ASC. RESULTS: A total of 524 and 545 patients were included during the ASC and the no-ASC periods, respectively. Twenty-eight patients (5.3%) from the ASC period were ESBL-E carriers. An ICU-acquired ESBL-E infection (median duration of risk exposure, 4 (range 2-9) days for both periods) occurred in 1.1% and 1.5% of patients admitted during the ASC and the no-ASC periods (p = 0.64), with no inter-period variation in incidence after adjustment on competing risks of death and ICU discharge (standardized hazard ratio (SHR) 2.32, 95% CI 0.80-6.73, p = 0.12). An admission during the no-ASC period exerted no independent impact on the hazards of ESBL-E infections (adjusted OR 1.16, 95% CI 0.38-3.50, p = 0.79), in-ICU death (SHR 1.22, 95% CI 0.93-1.59, p = 0.15) and extended length of stay (SHR for discharge 0.89, 95% CI 0.79-1.01, p = 0.08). Carbapenem exposure in patients without ESBL-E infection decreased between the ASC and no-ASC periods (75 versus 61 carbapenem-days per 1000 patient-days, p = 0.01). CONCLUSIONS: In a low-endemicity ICU with universal CP, the withdrawal of routine screening for ESBL-E carriage had no significant effect on the incidence of ICU-acquired ESBL-E infections and patient outcomes. Carbapenem consumption decreased in patients without ESBL-E infection.

French hospital discharge database (PMSI) and bacterial resistance: Is coding adapted to hospital epidemiology?

OBJECTIVE: A preliminary analysis of data consistency on different types of bacterial resistance by infection site and causative agents was conducted using the French hospital discharge database (French acronym PMSI) to assess the use of the database in a national cartography tool. MATERIAL AND METHODS: Hospital stays in medical, surgical, and obstetrical units were extracted from the 2014 PMSI database using the ICD-10 diagnosis codes. Bacterial infections, causative agents, and resistance corresponding to these stays were also identified. RESULTS: Data from 1258462 patients, corresponding to a total of 1617893 stays, was extracted. Among these stays, 46% were associated with a bacteria code and 7% with a resistance code. Lower respiratory tract infections were the most frequent infections (32% of stays; pneumonia in 95% of cases), followed by genitourinary infections (26%), intra-abdominal infections and diarrhoeas (24%), and skin and soft tissue infections (15%). Inconsistencies were observed between the types of infection and associated bacteria and between bacteria and associated resistance. These inconsistencies are likely due to initial coding errors. CONCLUSION: The cartography of bacterial infections cannot be developed using the data of the current PMSI coding. These results underline the need to improve the coding of PMSI data for its use as a complementary tool of epidemiological surveillance of bacterial infections.

A simple ultra-high-performance liquid chromatography-high resolution mass spectrometry assay for the simultaneous quantification of 15 antibiotics in plasma.

Antibiotic (ATB) treatment of critically ill patients with pathophysiological injuries remains a challenge due to the constant increase in antimicrobial resistance. Therapeutic drug monitoring (TDM) is advised for ATB dose adjustments to avoid suboptimal concentrations and dose-related adverse effects. Therefore, a single and reliable analytical method for a broad selection of ATBs was developed using a high-resolution mass spectrometry (HRMS) platform for frequent use in intensive care units. An UHPLC assay coupled to high resolution accurate mass acquisition has been developed for the quantification of penicillins (amoxicillin, oxacillin, piperacillin, and ticarcillin), cephalosporines (cefepime, cefotaxime, ceftazidime, and ceftriaxone), carbapenems (ertapenem, imipenem, and meropenem), lincosamide (clindamycin), quinolones (ofloxacin and ciprofloxacin) and tazobactam. Plasma samples (100µL) were spiked with an internal standard solution followed by protein precipitation. Separation was achieved on an Accucore C18 column, which enabled sample analysis every 9min. All compounds were detected in electrospray positive ion mode and quantified with a linear regression between 0.5 and 32mg/L (r2>0.998). Overall precision and accuracy did not exceed 15%. No significant matrix effect was observed for the studied ATBs. Stored stock solutions at -20°C were stable for 6 months, except for amoxicillin and imipenem. Analytes in plasma were stable for 24h under ambient conditions as well as in post-preparation in an autosampler, except for amoxicillin and imipenem. This HRMS assay provides the simultaneous quantification of 15 ATB; it fulfills the usual quality criteria and was successfully applied for routine TDM of ATBs. The method is based on a full scan acquisition, and it would be easy to add other compounds to the present panel in the future, as this assay has already been proven to be efficient for different classes of compounds.

[Coasting and ovarian stimulation protocols in high-responder patients undergoing assisted conception]. / Le coasting et les protocoles de stimulation chez les hyperrépondeuses en AMP.

Over-responsive patients are at risk of ovarian hyperstimulation, which may lead to severe complications. The choice of ovarian stimulation protocol or the use of a coasting (gonadotrophins suspension) with its associated risk of too strong ovarian response will be discussed herein. As for in vitro fertilization stimulation protocols, the best are probably those which use steadily increasing low doses of gonadotrophins, associated to GnRH agonists (low-dose protocols) or those which complete a double hypophyseal inhibition (estro-progestative association and GnRH agonists). GnRH antagonists may also reduce the risk of ovarian hyperstimulation, by estradiol drop. Outside the context of in vitro fertilization GnRH continuous administration or low -dose gonadotrophin stimulation are the best options. A coasting will be performed when an excess follicle response is documented. Under strict hormonal follow-up and within four days it allows achieving a high rate of pregnancy with a lower risk of hyperstimulation. Compared to other therapies of hyperstimulation syndrome, the coasting allows to avoid cycle cancellation or freezing of all embryos.

In vitro inhibition of platelet aggregation by bile salts.

In a series of in vitro experiments, the influence of bile salts on platelet aggregation by ADP or by collagen and on serotonin-14C release by collagen, was studied. Sodium salts of the following bile acids showed a clear inhibitory effect: glycochenodeoxycholic acid, taurochenodeoxycholic acid, glycocholic acid, taurocholic acid and cholic acid. Lowering the pH of the platelet-rich plasma resulted in decrease platelet aggregation by ADP and by collagen. Bile salts further enhanced the inhibitory effect of pH change. In contrast the sodium salt of chenodeoxycholic acid was the sole aggregation inducing bile salt we studied. Relating the above studies to the clinical situation of upper gastroduodenal mucosal haemorrhage, we suggest that biliary reflux as well as the acidic environment may contribute to a poor haemostatic response by impaired platelet aggregation in the upper gastrointestinal tract of otherwise normal human subjects.

Inhibitory effect of acetylsalicylic acid on human platelet function in normal volunteers and in women using a combined oral contraceptive regime.

Six parameters related to the release reaction were measured simultaneously in 10 human volunteers prior to the intake of one single dose of 1 g acetylsalicylic acid and 1, 4, 5, 6 and 7 days alter: deltaE5 with diluted collagen, deltaE10 with Thrombofax and the serotonin-14C release by undiluted and diluted collagen, by Thrombofax and by bovine plasma. The duration of the inhibitory effect varied according to the test used. It was the most prolonged (through the 7th day) if serotonin-14C release by diluted collagen was measured. A systematic investigation of the platelet release reaction in women taking a combined oral contraceptive was also performed. There were no statistically significant differences from a control group. No difference in acetylsalicylic acid sensitivity, measured 24 hours after intake of 1 g of aspirin, could be demonstrated.

New developments in stem cell transplantation with special reference to the first in utero transplants in humans.

Based on the experience acquired in post-natal liver transplantation since 1974, we recently initiated pre-natal, in utero stem cell transplantation from the human fetal liver. The first two fetuses that we treated had immunodeficiencies, the third one had thalassemia major. Donors and recipients were not matched. The fetal cells were infused in the umbilical vein of the first two patients and injected intraperitoneally into the third one, under ultrasonic visualization. The first patient, born in 1988, has both engraftment of donor cells and reconstitution of cell-mediated immunity. This child, who had bare lymphocyte syndrome, has no clinical manifestation of the disease and he lives normally at home. The second child, born in 1989, has not yet developed a significant reconstitution of immunity although donor cell engraftment has been proven (Y chromosome in this female patient). The third patient has also evidence of donor cell take (Y chromosome in a female patient) but the effect on thalassemia has not yet been fully analyzed (donor hemoglobin present in small quantity). In all 3 cases, no side-effect of any kind developed in the mother nor in the fetus. Several advantages appear to be associated with in utero FLT: increased probability of graft take, ideal isolation of patient (in the uterus), optimal environment for fetal cell development (in the fetal host).

Stereospecific distribution of fatty acids in human plasma triglycerides.

Because of a biological difference between both primary hydroxylgroups of glycerol there are three distinct hydroxylgroups esterified with fatty acids in triglycerides. The distribution of fatty acids in the three distinct positions of triglycerides can be investigated by a combination of partial hydrolysis of triglycerides by pancreatic lipase, phosphorylation of the diglycerides formed and the stereospecific action of phospholipase A on phosphatides. Plasma triglycerides from normal and hyperlipemic humans are analysed. Human plasma triglycerides are highly asymmetric. The 1-position contains more than twice as much palmitic acid as the 3-position. Statistically significant differences are found between normal and hyperlipemic humans for palmitic and linoleic acid at the 2-position, and for oleic and linoleic acid at the 3-position.

Determination of molybdenum in human serum by neutron activation analysis.

Several investigators have reported serum molybdenum determinations in healthy humans. However, their results diverge quite widely. We determined the element by neutron activation analysis in 30 individuals. We found a mean value of 0.58 ng/ml, a standard deviation of 0.21 ng/ml and a range of 0.28--1.17 ng/ml.

Influence of pathological state on the acoustic attenuation coefficient slope of liver.

The acoustic attenuation coefficient slope (beta) of liver was estimated in vivo from the spectral difference of returned echoes. beta of normal young subjects was lower than that of older subjects (mean: 0.340 vs 0.418 dB/cm.MHz). Limited fluid withdrawal from the body by haemodialysis did not affect beta. In alcoholic liver disease beta was related to the amount of fat and of fibrous tissue in liver biopsy specimens. High values of beta were observed as soon as the degree of steatosis exceeded 5 vol%. There was a similar increase of beta in the presence of fibrous interlobular septa. In normal liver beta was related to the amount of triglycerides in the liver specimen.

Sample contamination as a source of error in trace-element analysis of biological samples.

Trace-element levels estimated by different investigators are often disparate. It is becoming increasingly evident that sample contamination may explain some of the discrepancies. A method has been developed for the direct estimation of potential errors. This shows that extraneous additions occurring during sample collection and preparation may give rise to grossly misleading results on subsequent analysis.