Determination of the bandgap and split-off band of wurtzite GaAs

GaAs nanowires with a 100% wurtzite structure are synthesized by the vapor-liquid-solid method in a molecular beam epitaxy system, using gold as a catalyst. We use resonant Raman spectroscopy and photoluminescence to determine the position of the crystal-field split-off band of hexagonal wurtzite GaAs. The temperature dependence of this transition enables us to extract the value at 0 K, which is 1.982 eV. Our photoluminescence excitation spectroscopy measurements are consistent with a band gap of GaAs wurtzite below 1.523 eV

Feasibility and performance study for a space-borne 1645nm OPO for French-German satellite mission MERLIN

We present a theoretical and experimental analysis of a pulsed 1645 nm optical parametric oscillator (OPO) conducted to prove the feasibility of such a device for a spaceborne laser transmitter in an integrated path differential absorption (IPDA) lidar system. The investigation is part of the French-German satellite mission MERLIN (Methane Remote Sensing Lidar Mission). As an effective greenhouse gas, methane plays an important role for the global climate. The architecture of the OPO is based on a conceptual design developed by DLR, consisting of two KTA crystals in a four-mirror-cavity. One of the cavity mirrors is piezo-driven to provide single frequency operation of the OPO. Using numerical simulations, we studied the performance and alignment tolerances of such a setup with KTP and KTA and investigated means to optimize the optical design by increasing the efficiency and decreasing the fluence on the optical components. For the experimental testing of the OPO, we used the INNOSlab-based ESA pre-development model ATLAS as pump laser at 1064 nm. At a pulse frequency of 25 Hz this MOPA delivers a pump energy up to 45 mJ with a beam quality factor of about M² = 1.3. With KTP as nonlinear crystal the OPO obtained 9.2 mJ pulse energy at 1645 nm from 31.5 mJ of the pump and a pump pulse duration of 42 ns. This corresponds to an optical/optical efficiency of 29%. After the pump pulse was reduced to 24 ns a similar OPO performance could be obtained by adapting the pump beam radius

Lower ribavirin biodisponibility in patients with HIV-HCV coinfection in comparison with HCV monoinfected patients.

International audienceBACKGROUND: In HIV infected patients, the impact of ribavirin (RBV) pharmacology on sustained virologic response (SVR) to hepatitis C virus (HCV) treatment has not been fully investigated. The objective of this study was to compare the early RBV plasma exposure between a population of HIV-HCV coinfected patients and an HCV monoinfected group. METHODS: Early RBV plasma exposure (expressed as Area Under the Curve (AUC) from 0 to 4 h) after a 600 mg first dose of RBV was measured in a population of HIV-HCV coinfected patients in comparison with an HCV monoinfected group. Peripheral blood samples were collected before the 600 mg RBV first dose (T0) to ensure no detectable baseline plasma RBV, and then 30 mn, 1, 2 and 4 hours after RBV intake (T0.5, T1, T2 and T4). RESULTS: Eighty-six patients with chronic hepatitis C entered the study among whom 23 (27%) were HIV-HCV coinfected. Coinfected patients had a significantly lower RBV-AUC(0-4h) (median: 1469 μg*h/L [range 936-3677]) compared with monoinfected patients (2030 μg*h/L [851-7700]; p = 0.018). This RBV under exposure in coinfected patients persisted after normalization of AUC to RBV dose per kilogram of body weight (182 μg*h/L [110-425] versus 271 μg*h/L [82-1091], p = 0.001). CONCLUSIONS: These results suggest that lower early bioavailability of RBV could be one of the reasons for lower SVR in HIV-HCV coinfected patients treated with pegylated interferon/RBV combination therapy. RBV plasma underexposure seems to be associated with the immunological status of the patients with lower AUC(0-4h) values observed in the more immunosuppressed coinfected patients

A highly virulent variant of HIV-1 circulating in the Netherlands

We discovered a highly virulent variant of subtype-B HIV-1 in the Netherlands. One hundred nine individuals with this variant had a 0.54 to 0.74 log10 increase (i.e., a ~3.5-fold to 5.5-fold increase) in viral load compared with, and exhibited CD4 cell decline twice as fast as, 6604 individuals with other subtype-B strains. Without treatment, advanced HIV-CD4 cell counts below 350 cells per cubic millimeter, with long-term clinical consequences-is expected to be reached, on average, 9 months after diagnosis for individuals in their thirties with this variant. Age, sex, suspected mode of transmission, and place of birth for the aforementioned 109 individuals were typical for HIV-positive people in the Netherlands, which suggests that the increased virulence is attributable to the viral strain. Genetic sequence analysis suggests that this variant arose in the 1990s from de novo mutation, not recombination, with increased transmissibility and an unfamiliar molecular mechanism of virulence

Importance of Baseline Prognostic Factors With Increasing Time Since Initiation of Highly Active Antiretroviral Therapy: Collaborative Analysis of Cohorts of HIV-1-Infected Patients

Background: The extent to which the prognosis for AIDS and death of patients initiating highly active antiretroviral therapy (HAART) continues to be affected by their characteristics at the time of initiation (baseline) is unclear. Methods: We analyzed data on 20,379 treatment-naive HIV-1- infected adults who started HAART in 1 of 12 cohort studies in Europe and North America (61,798 person-years of follow-up, 1844 AIDS events, and 1005 deaths). Results: Although baseline CD4 cell count became less prognostic with time, individuals with a baseline CD4 count 350 cells/μL (hazard ratio for AIDS = 2.3, 95% confidence interval [CI]: 1.0 to 2.3; mortality hazard ratio = 2.5, 95% CI: 1.2 to 5.5, 4 to 6 years after starting HAART). Rates of AIDS were persistently higher in individuals who had experienced an AIDS event before starting HAART. Individuals with presumed transmission by means of injection drug use experienced substantially higher rates of AIDS and death than other individuals throughout follow-up (AIDS hazard ratio = 1.6, 95% CI: 0.8 to 3.0; mortality hazard ratio = 3.5, 95% CI: 2.2 to 5.5, 4 to 6 years after starting HAART). Conclusions: Compared with other patient groups, injection drug users and patients with advanced immunodeficiency at baseline experience substantially increased rates of AIDS and death up to 6 years after starting HAART

Trastuzumab resistance: Bringing tailored therapy to the clinic

SCOPUS: re.jinfo:eu-repo/semantics/publishe

Long-term neurological symptoms after acute COVID-19 illness requiring hospitalization in adult patients: insights from the ISARIC-COVID-19 follow-up study

in this study we aimed to characterize the type and prevalence of neurological symptoms related to neurological long-COVID-19 from a large international multicenter cohort of adults after discharge from hospital for acute COVID-19

Sex differences in post-acute neurological sequelae of SARS-CoV-2 and symptom resolution in adults after coronavirus disease 2019 hospitalization: an international multi-centre prospective observational study

: Although it is known that coronavirus disease 2019 can present with a range of neurological manifestations and in-hospital complications, sparse data exist on whether these initial neurological symptoms of coronavirus disease 2019 are closely associated with post-acute neurological sequelae of SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2; PANSC) and whether female versus male sex impacts symptom resolution. In this international, multi-centre, prospective, observational study across 407 sites from 15 countries (30 January 2020 to 30 April 2022), we report the prevalence and risk factors of PANSC among hospitalized adults and investigate the differences between males and females on neurological symptom resolution over time. PANSC symptoms included altered consciousness/confusion, fatigue/malaise, anosmia, dysgeusia and muscle ache/joint pain, on which information was collected at index hospitalization and during follow-up assessments. The analysis considered a time to the resolution of individual and all neurological symptoms. The resulting times were modelled by Weibull regression, assuming mixed-case interval censoring, with sex and age included as covariates. The model results were summarized as cumulative probability functions and age-adjusted and sex-adjusted median times to resolution. We included 6862 hospitalized adults with coronavirus disease 2019, who had follow-up assessments. The median age of the participants was 57 years (39.2% females). Males and females had similar baseline characteristics, except that more males (versus females) were admitted to the intensive care unit (30.5 versus 20.3%) and received mechanical ventilation (17.2 versus 11.8%). Approximately 70% of patients had multiple neurological symptoms at the first follow-up (median = 102 days). Fatigue (49.9%) and myalgia/arthralgia (45.2%) were the most prevalent symptoms of PANSC at the initial follow-up. The reported prevalence in females was generally higher (versus males) for all symptoms. At 12 months, anosmia and dysgeusia were resolved in most patients, although fatigue, altered consciousness and myalgia remained unresolved in >10% of the cohort. Females had a longer time to the resolution (5.2 versus 3.4 months) of neurological symptoms at follow-up for those with more than one neurological symptom. In the multivariable analysis, males were associated with a shorter time to the resolution of symptoms (hazard ratio = 1.53; 95% confidence interval = 1.39-1.69). Intensive care unit admission was associated with a longer time to the resolution of symptoms (hazard ratio = 0.68; 95% confidence interval = 0.60-0.77). Post-discharge stroke was uncommon (0.3% in females and 0.5% in males). Despite the methodological challenges involved in the collection of survey data, this international multi-centre prospective cohort study demonstrated that PANSC following index hospitalization was high. Symptom prevalence was higher and took longer to resolve in females than in males. This supported the fact that while males were sicker during acute illness, females were disproportionately affected by PANSC