Study of the surface modification of the PMMA by UV-radiation

AbstractIn this paper, we present the evolution of the thermo-mechanical properties of PolyMethylMethAcrylate (PMMA) materials exposed to Ultra-Violet (UV) light. We observed a decrease of the strength and Young’s modulus with the increase of the UV irradiation dose, which have been correlated to the physico-chemical degradation of the PMMA and the occurrence of surface damage

Patients with schizophrenia and their finances: how they spend their money

Introduction: Although most patients with schizophrenia rely on state financial support, little is known about their expenses and how they use the money at their discretion. However, the ability to budget is a predictive factor in rehabilitation. An assessment of financial management skills could make it possible to develop more appropriate psycho-social assistance. Method: Fifty-seven outpatients with schizophrenia treated in the public sector in Geneva, Switzerland took part in the study. Psychosocial, diagnostic, neurocognitive and symptomatological measures were collected. Data were gathered on patients' incomes and quality of life. A prospective analysis of their expenses during a 1-month period was also performed. Results: Median income was 4,125 Swiss francs per month (i.e., 3,372 US dollars). After paying fixed expenses (which were handled with or without the assistance of a representative payee), a mean of 400 Swiss francs remained at their disposal to use as they wished. Seventy-two percent of this money was devoted to the use of psychoactive substances (e.g., cigarettes, alcohol, cannabis) or various drinks in coffee houses, and 28% on leisure activities (trips, sports and other recreational activities). Eighty-four percent of patients would have liked to have more money for leisure activities. The study was well-accepted and led to modification of the treatment plan in 84% of cases. Conclusion: Most of the discretionary money patients received was used for buying substances with addictive properties; this may hinder the practice of activities favouring recovery. Thus, it appears essential to guide patients in the management of their budget

As time goes by - Overlooking 40 years of inpatient burn treatment at a national pediatric burn center in Switzerland

BACKGROUND Despite extensive prevention programs, burns remain a frequent cause of injury in Switzerland with a known age peak in children. Pediatric burns may cause substantial morbidity, a psyochological burden and therapy related high economic costs. To improve preventive measures, precise knowledge of etiology and treatment of pediatric burns in Switzerland as well as their temporal evolution is indispensable. METHODS The present retrospective analysis included pediatric burn patients admitted for acute treatment to the Pediatric Burn Center of the University Children`s Hospital Zurich over the last four decades. Sociodemographic, injury related, and treatment related data were extracted from medical records. Linear regression analysis was applied to determine temporal changes during the past four decades and chi-square and t-tests were applied wherever applicable. RESULTS A total of 3425 acute burn patients were included in the study between 1977 and 2020, corresponding to a mean of 89 patients/year. Mean age was 3.60 ± 4.12 years, three quarters of all patients were preschool children (0-5 years) and mean total body surface area (TBSA) burned was 8.01% ± 9.57%, however only around one fifth had severe burns (>10% TBSA). Scald burns (65.31%) and flame burns (32.99%) were most commonly seen. Linear regression analysis showed the total number of thermal injuries treated at our center to have increased significantly as of 2004 (p < 0.001). Separate analysis showed the same for small and medium (<10% TBSA) burns (p < 0.001), whereas the number of severe burns did not increase significantly. Length of stay (LOS) was highly associated with %TBSA burned. The percentage of female patients amongst all patients increased over time (p = 0.012). LOS per TBSA burned decreased significantly (p < 0.001). CONCLUSION The present data show pediatric burns to remain a major health burden in Switzerland, especially small and medium burns in preschool children. Prevention programs should focus on this age population as well as on scald and flame burns as most common etiologies. The observed decrease in length of stay suggests a major improvement in overall quality of care in pediatric burns and supports centralization of care

Characterization of offline analysis of particulate matter with FIGAERO-CIMS

Measurements of the molecular composition of organic aerosol (OA) constituents improve our understanding of sources, formation processes, and physicochemical properties of OA. One instrument providing such data at a time resolution of minutes to hours is the chemical ionization time-of-flight mass spectrometer with filter inlet for gases and aerosols (FIGAERO-CIMS). The technique collects particles on a filter, which are subsequently desorbed, and the evaporated molecules are ionized and analyzed in the mass spectrometer. However, long-term measurements using this technique and/or field deployments at several sites simultaneously require substantial human and financial resources. The analysis of filter samples collected outside the instrument (offline) may provide a more cost-efficient alternative and makes this technology available for the large number of particle filter samples collected routinely at many different sites globally. Filter-based offline use of the FIGAERO-CIMS limits this method, albeit to particle-phase analyses, which is likely at a reduced time resolution compared to online deployments. Here we present the application and assessment of offline FIGAERO-CIMS, using Teflon and quartz fiber filter samples that were collected in autumn 2018 in urban Beijing. We demonstrate the feasibility of the offline application with a “sandwich” sample preparation for the over 900 identified organic compounds with (1) high signal-to-noise ratios, (2) high repeatability, and (3) linear signal response to the filter loadings. Comparable overall signals were observed between the quartz fiber and Teflon filters for 12 and 24 h samples but with larger signals for semi-volatile compounds for the quartz fiber filters, likely due to adsorption artifacts. We also compare desorption profile (thermogram) shapes for the two filter materials. Thermograms are used to derive volatility qualitatively based on the desorption temperature at which the maximum signal intensity of a compound is observed (Tmax⁡). While we find that Tmax⁡ can be determined with high repeatability (±5.7 ∘C) from the duplicate tests for one filter type, we observe considerable differences in Tmax⁡ between the quartz and Teflon filters, warranting further investigation into the thermal desorption characteristics of different filter types. Overall, this study provides a basis for expanding OA molecular characterization by FIGAERO-CIMS to situations where and when deployment of the instrument itself is not possible.</p

Sexual selection and the evolution of condition-dependence: an experimental test at two resource levels

Stronger condition-dependence in sexually selected traits is well-documented, but how this relationship is established remains unknown. Moreover, resource availability can shape responses to sexual selection, but resource effects on the relationship between sexual selection and condition-dependence are also unknown. In this study, we directly test the hypotheses that sexual selection drives the evolution of stronger-condition-dependence and that resource availability affects the outcome, by evolving fruit flies (Drosophila melanogaster) under relatively strong or weak sexual selection (through varied sex ratios) and at resource-poor or resource-rich adult diets. We then experimentally manipulated condition via developmental diet and assessed condition-dependence in adult morphology, behavior, and reproduction. We observed stronger condition-dependence in female size in male-biased populations and in female ovariole production in resource-limited populations. However, we found no evidence that male condition-dependence increased in response to sexual selection, or that responses depended on resource levels. These results offer no support for the hypotheses that sexual selection increases male condition-dependence or that sexual selection's influence on condition-dependence is influenced by resource availability. Our study is, to our knowledge, the first experimental test of these hypotheses. If the results we report are general, then sexual selection's influence on the evolution of condition-dependence may be less important than predicted

Saturated free fatty acids induce cholangiocyte lipoapoptosis

Recent studies have identified a cholestatic variant of nonalcoholic fatty liver disease (NAFLD) with portal inflammation and ductular reaction. Based on reports of biliary damage, as well as increased circulating free fatty acids (FFAs) in NAFLD, we hypothesized the involvement of cholangiocyte lipoapoptosis as a mechanism of cellular injury. Here, we demonstrate that the saturated FFAs palmitate and stearate induced robust and rapid cell death in cholangiocytes. Palmitate and stearate induced cholangiocyte lipoapoptosis in a concentration-dependent manner in multiple cholangiocyte-derived cell lines. The mechanism of lipoapoptosis relied on the activation of caspase 3/7 activity. There was also a significant up-regulation of the proapoptotic BH3-containing protein, PUMA. In addition, palmitate-induced cholangiocyte lipoapoptosis involved a time-dependent increase in the nuclear localization of forkhead family of transcription factor 3 (FoxO3). We show evidence for posttranslational modification of FoxO3, including early (6 hours) deacetylation and dephosphorylation that coincide with localization of FoxO3 in the nuclear compartment. By 16 hours, nuclear FoxO3 is both phosphorylated and acetylated. Knockdown studies confirmed that FoxO3 and its downstream target, PUMA, were critical for palmitate- and stearate-induced cholangiocyte lipoapoptosis. Interestingly, cultured cholangiocyte-derived cells did not accumulate appreciable amounts of neutral lipid upon FFA treatment. CONCLUSION: Our data show that the saturated FFAs palmitate and stearate induced cholangiocyte lipoapoptosis by way of caspase activation, nuclear translocation of FoxO3, and increased proapoptotic PUMA expression. These results suggest that cholangiocyte injury may occur through lipoapoptosis in NAFLD and nonalcoholic steatohepatitis patients

A Critical Review of the \u3csup\u3e15\u3c/sup\u3eN\u3csub\u3e2\u3c/sub\u3e Tracer Method to Measure Diazotrophic Production in Pelagic Ecosystems

Dinitrogen (N2) fixation is an important source of biologically reactive nitrogen (N) to the global ocean. The magnitude of this flux, however, remains uncertain, in part because N2 fixation rates have been estimated following divergent protocols and because associated levels of uncertainty are seldom reported—confounding comparison and extrapolation of rate measurements. A growing number of reports of relatively low but potentially significant rates of N2 fixation in regions such as oxygen minimum zones, the mesopelagic water column of the tropical and subtropical oceans, and polar waters further highlights the need for standardized methodological protocols for measurements of N2 fixation rates and for calculations of detection limits and propagated error terms. To this end, we examine current protocols of the 15N2 tracer method used for estimating diazotrophic rates, present results of experiments testing the validity of specific practices, and describe established metrics for reporting detection limits. We put forth a set of recommendations for best practices to estimate N2 fixation rates using 15N2 tracer, with the goal of fostering transparency in reporting sources of uncertainty in estimates, and to render N2 fixation rate estimates intercomparable among studies

Variation in chemical composition and volatility of oxygenated organic aerosol in different rural, urban, and mountain environments

The apparent volatility of atmospheric organic aerosol (OA) particles is determined by their chemical composition and environmental conditions (e.g., ambient temperature). A quantitative, experimental assessment of volatility and the respective importance of these two factors remains challenging, especially in ambient measurements. We present molecular composition and volatility of oxygenated OA (OOA) particles in different rural, urban, and mountain environments (including Chacaltaya, Bolivia; Alabama, US; Hyytiälä, Finland; Stuttgart and Karlsruhe, Germany; and Delhi, India) based on deployments of a filter inlet for gases and aerosols coupled to a high-resolution time-of-flight chemical ionization mass spectrometer (FIGAERO-CIMS). We find on average larger carbon numbers (nC) and lower oxygen-to-carbon (O : C) ratios at the urban sites (nC: 9.8 ± 0.7; O : C: 0.76 ± 0.03; average ±1 standard deviation) compared to the rural (nC: 8.8 ± 0.6; O : C: 0.80 ± 0.05) and mountain stations (nC: 8.1 ± 0.8; O : C: 0.91 ± 0.07), indicative of different emission sources and chemistry

Sexual selection and the evolution of condition-dependence: an experimental test at two resource levels

Stronger condition-dependence in sexually selected traits is well-documented, but how this relationship is established remains unknown. Moreover, resource availability can shape responses to sexual selection, but resource effects on the relationship between sexual selection and condition-dependence are also unknown. In this study, we directly test the hypotheses that sexual selection drives the evolution of stronger-condition-dependence and that resource availability affects the outcome, by evolving fruit flies (Drosophila melanogaster) under relatively strong or weak sexual selection (through varied sex ratios) and at resource-poor or resource-rich adult diets. We then experimentally manipulated condition via developmental diet and assessed condition-dependence in adult morphology, behavior, and reproduction. We observed stronger condition-dependence in female size in male-biased populations and in female ovariole production in resource-limited populations. However, we found no evidence that male condition-dependence increased in response to sexual selection, or that responses depended on resource levels. These results offer no support for the hypotheses that sexual selection increases male condition-dependence or that sexual selection’s influence on condition-dependence is influenced by resource availability. Our study is, to our knowledge, the first experimental test of these hypotheses. If the results we report are general, then sexual selection’s influence on the evolution of condition-dependence may be less important than predicted