377 research outputs found
Torrefaction of residues and by-products from sunflower chain
The high heterogeneity of some residual biomasses makes rather difficult their energy use and standardisation is a key aspect for these fuel products. Torrefaction is an interesting process used to improve the quality of ligno-cellulosic biomasses and to achieve standardisation. In the present study torrefaction has been employed on residues and by-products deriving from sunflower production chain, in particular sunflower stalks and oil press cake. The thermal behaviour of materials has been studied at first by thermo-gravimetric analysis in order to identify torrefaction temperatures range. Different residence time and torrefaction temperatures have been employed in a bench top torrefaction reactor afterwards. Analyses of raw and torrefied materials have been carried out to assess the influence of the process. As a consequence of torrefaction, the carbon and ash contents increase while the volatilisation range is reduced making the material more stable and standardised. Mass yield, energy yield and energy densification reach values of about 60 %, 80 % and 1.33 for sunflower stalks and 64 %, 85 % and 1.33 for sunflower oil press cake respectively. As highlighted by results, torrefaction is more interesting for sunflower stalks than oil cake and husks because of the different starting characteristics. Untreated oil cake and husks already show a good high heating value and the eventual torrefaction should be mild. On the contrary for sunflower stalks the process is more useful and could be more severe
Effects of Silica Modification (Mg, Al, Ca, Ti, and Zr) on Supported Cobalt Catalysts for H<sub>2</sub>-Dependent CO<sub>2</sub> Reduction to Metabolic Intermediates
Serpentinizing hydrothermal systems generate H2 as a reductant and harbor catalysts conducive to geochemical CO2 conversion into reduced carbon compounds that form the core of microbial autotrophic metabolism. This study characterizes mineral catalysts at hydrothermal vents by investigating the interactions between catalytically active cobalt sites and silica-based support materials on H2-dependent CO2 reduction. Heteroatom incorporated (Mg, Al, Ca, Ti, and Zr), ordered mesoporous silicas are applied as model support systems for the cobalt-based catalysts. It is demonstrated that all catalysts surveyed convert CO2 to methane, methanol, carbon monoxide, and low-molecular-weight hydrocarbons at 180 °C and 20 bar, but with different activity and selectivity depending on the support modification. The additional analysis of the condensed product phase reveals the formation of oxygenates such as formate and acetate, which are key intermediates in the ancient acetyl-coenzyme A pathway of carbon metabolism. The Ti-incorporated catalyst yielded the highest concentrations of formate (3.6 mM) and acetate (1.2 mM) in the liquid phase. Chemisorption experiments including H2 temperature-programmed reduction (TPR) and CO2 temperature-programmed desorption (TPD) in agreement with density functional theory (DFT) calculations of the adsorption energy of CO2 suggest metallic cobalt as the preferential adsorption site for CO2 compared to hardly reducible cobalt–metal oxide interface species. The ratios of the respective cobalt species vary depending on the interaction strength with the support materials. The findings reveal robust and biologically relevant catalytic activities of silica-based transition metal minerals in H2-rich CO2 fixation, in line with the idea that autotrophic metabolism emerged at hydrothermal vents
Critically appraised topic for the most effective and safe treatment for canine generalised demodicosis
Background
Canine generalised demodicosis is an inflammatory parasitic skin disease caused by an excessive proliferation of Demodex spp. Generalized demodicosis is a severe skin disease, that can be life threatening if not treated properly. Many of the current treatment options are not licensed for the treatment of generalised demodicosis, it have a low safety margin and may be poorly efficacious and time-consuming for the owner; there is a need for a safe, efficacious treatment for canine demodicosis. Our objective was to systematically review the literature to determine the most effective and safe topical or systemic therapy for canine generalised demodicosis. Single case reports and case series with fewer than five patients were not reviewed as they were considered to be poor quality evidence. A detailed literature search identified 21 relevant clinical trials and these were critically assessed.
Results
The analysis of the best available evidence on March 5, 2018, suggests that six are the most effective and safe treatments for generalised canine demodicosis including (in alphabetical order): doramectin (oral or parenteral); fluralaner (oral); imidacloprid/moxidectin (topical); ivermectin (oral, not as first choice treatment); milbemycin oxime (oral); and sarolaner (oral). There was insufficient evidence to allow comment on the appropriateness of other treatment protocols for canine generalised demodicosis in this CAT.
Conclusions
In our critical appraisal of the best scientific literature, there is evidence for recommending the use of 6 therapeutic options against demodectic mange. Further, in vivo, controlled, randomized and blinded clinical trials are required, to evaluate new therapies
Survival Outcomes and Effect of Early vs. Deferred cART Among HIV-Infected Patients Diagnosed at the Time of an AIDS-Defining Event: A Cohort Analysis
Objectives: We analyzed clinical progression among persons diagnosed with HIV at the time of an AIDS-defining event, and assessed the impact on outcome of timing of combined antiretroviral treatment (cART).Methods: Retrospective, European and Canadian multicohort study.. Patients were diagnosed with HIV from 1997-2004 and had clinical AIDS from 30 days before to 14 days after diagnosis. Clinical progression (new AIDS event, death) was described using Kaplan-Meier analysis stratifying by type of AIDS event. Factors associated with progression were identified with multivariable Cox regression. Progression rates were compared between those starting early (<30 days after AIDS event) or deferred (30-270 days after AIDS event) cART.Results: The median (interquartile range) CD4 count and viral load (VL) at diagnosis of the 584 patients were 42 (16, 119) cells/mu L and 5.2 (4.5, 5.7) log(10) copies/mL. Clinical progression was observed in 165 (28.3%) patients. Older age, a higher VL at diagnosis, and a diagnosis of non-Hodgkin lymphoma (NHL) (vs. other AIDS events) were independently associated with disease progression. Of 366 patients with an opportunistic infection, 178 (48.6%) received early cART. There was no significant difference in clinical progression between those initiating cART early and those deferring treatment (adjusted hazard ratio 1.32 [95% confidence interval 0.87, 2.00], p = 0.20).Conclusions: Older patients and patients with high VL or NHL at diagnosis had a worse outcome. Our data suggest that earlier initiation of cART may be beneficial among HIV-infected patients diagnosed with clinical AIDS in our setting
Effect of stocking density and use of environmental enrichment materials on the welfare and the performance of pigs in the growth and finishing phases
Aim of study: To evaluate the effects of stocking density and the use of environmental enrichment (EE) objects on the welfare and the performance of pigs in the growing and finishing phases.Area of study: The southern region of Brazil.Material and methods: A total of 240 pigs, 120 immunocastrated males and 120 females, with an initial weight of 22.38 ± 2.38 kg and mean age of 65 days, were submitted to two stocking densities conditions (0.85 and 1.28 m²pig) with and without EE for 117 days. The experimental design was a 2×2×2 factorial (two categories, two densities, and two EE conditions), with six replicates. Performance variables and behavior were evaluated.Main results: For stocking density, there was a significant difference in the finishing phase from 148 to 161 days of age for the final weight (FW), average daily weight gain (ADWG), and feed conversion rate (FCR). For the EE factor, there was no difference in any of the phases or in the overall period. In the overall period, the higher availability of space improved the results of FW (140.56 kg vs 136.63 kg), ADWG (1.005 kg vs 0.974 kg), and FCR (2.05 vs 2.10). There was no effect of EE, stocking densities, or their interaction on the frequency of different behaviors of the pigs in the growth and finishing phases.Research highlights: There was no effect of interactions between enriched environments, stocking densities, and sex for animal performance and behavioral frequencies; however, differences between the factors were observed separately. The higher availability of space improved the results of FW, ADWG, and FCR
INITIAL HIGH ELECTRIC FIELD – VACUUM ARC BREAKDOWN TEST RESULTS FOR ADDITIVELY MANUFACTURED PURE COPPER ELECTRODES
Additive Manufacturing (AM) is already wellestablished for various manufacturing pplications,
providing many benefits such as design freedom, novel and complex cooling designs for the parts and different performance improvements, as well as significantly reducing the production time. With the mentioned characteristics, AM is also being considered as a
technology for manufacturing a Radio Frequency Quadrupole (RFQ) prototype. For this application, an important parameter is the voltage holding capability of the surfaces. Furthermore, the voltage holding capability of pure copper surfaces manufactured by AM is of interest for the accelerator community at large for prospective future developments. To characterize these properties, a series of high electric field tests were performed on pure copper electrodes produced by AM, using the CERN pulsed highvoltage DC system. The tests were carried out with AM produced electrodes with large surface roughness. During
the testing process, a high vacuum was maintained. The electric breakdown rate was also monitored to ensure not to exceed the breakdown limit of 10ିହ breakdowns per pulse. The achieved results provide the first, initial reference values for the performance of AM built pure
copper electrodes for vacuum arc breakdown testing. Initial results prove the capability of AM electrodes to hold a high electric field, while having low breakdown rates. These are crucial results for further AM technology usage for different AM pure-copper accelerator components
po 472 chemotherapy resistance associated epithelial to endothelial transition in gastric cancer
Introduction Gastric cancer (GC) is the fifth most common cancer worldwide and the third leading cause of cancer-related deaths. To date, gastrectomy and chemotherapy are the only therapeutic options, but drug resistance is the main cause for treatment failure. Vasculogenic mimicry (VM) is a new model of neovascularization in aggressive tumours and has been correlated with poor prognosis in GC patients. Our group has developed chemotherapy-resistant GC cells using the Caucasian adenocarcinoma cell line AGS and three drugs among the most used in clinic (5-fluorouracil, cisplatin and paclitaxel) henceforward denominated 5FUr, CISr, TAXr. Our study has highlighted phenotypical differences among chemo-sensitive and chemo-resistant cell lines such as acquisition of stem-like phenotype and increased capacity to form vessels. Material and methods Establishment of AGS resistant cell lines exposing cells to increasing dilution of drugs for over 9 months up to dilutions higher than IC50 values initially verified on AGS cells through MTT analysis. Quantitative RT-PCR, flow cytometry and western blot analysis for stemness and VM markers. Vasculogenic mimicryassay Results and discussions AGS cells acquired chemoresistance as indicated by the increase of IC50 values in drug-treated cells with respect to AGS. Furthermore, MTT assay highlighted that there is not cross-resistance among 5FUr, CISr and TAXr. Supportive data is that cells are MDR1 negative. Resistant cells showed an upregulation of Yamanaka factors either in qPCR and flow cytometer analysis, and particularly interesting is ALDH overexpression in 5FUr. TWIST upregulation suggested the investigation of VM which resulted particularly enhanced in 5FUr cells which demonstrated their ability to form and sustain vessels up to 96 hours in the tube formation assay. Markers of VM such Laminin γ2 and Ephrin A2 showed an increase in resistant cells and especially in 5FUr. Conclusion One of the most interesting result is that 5FUr cells acquire stemness properties and are positive to the tube formation assay suggesting that VM might be one mechanisms adopted by cells to avoid drugs exposure. These findings suggest that acquisition of chemoresistance could cause a relapse of disease in which tumour cells take advantage of their capability to perform VM in order to self-sustain their growth and that may be cause of poor outcomes
Fractional snow cover in the Colorado and Rio Grande basins, 1995-2002
A cloud-masked fractional snow-covered area (SCA) product gridded at 1 km was developed from the advanced very high resolution radiometer for the Colorado River and upper Rio Grande basins for 1995-2002. Cloud cover limited SCA retrievals on any given 1-km2 pixel to on average once per week. There were sufficient cloud-free scenes to map SCA over at least part of the basins up to 21 days per month, with 3 months having only two scenes sufficiently cloud free to process. In the upper Colorado and upper Grande, SCA peaked in February-March. Maxima were 1-2 months earlier in the lower Colorado. Averaged over a month, as much as 32% of the upper Colorado and 5.5% of the lower Colorado were snow covered. Snow cover persisted longest at higher elevations for both wet and dry years. Interannual variability in snow cover persistence reflected wet-dry year differences. Compared with an operational (binary) SCA product produced by the National Operational Hydrologic Remote Sensing Center, the current products classify a lower fraction of pixels as having detectable snow and being cloud covered (5.5% for SCA and 6% for cloud), with greatest differences in January and June in complex, forested terrain. This satellite-derived subpixel determination of snow cover provides the potential for enhanced hydrologic forecast abilities in areas of complex, snow-dominated terrain. As an example, we merged the SCA product with interpolated ground-based snow water equivalent (SWE) to develop a SWE time series. This interpolated, masked SWE peaked in April, after SCA peaked and after some of the lower-elevation snow cover had melted. Copyright 2008 by the American Geophysical Union
Clinical Outcomes in Persons Coinfected With Human Immunodeficiency Virus and Hepatitis C Virus: Impact of Hepatitis C Virus Treatment
Background:
A hepatitis C (HCV) cure is associated with changes in lipids and inflammatory biomarkers, but its impact on clinical endpoints among treated human immunodeficiency virus (HIV)/HCV coinfected persons is unclear. /
Methods:
People living with HIV from EuroSIDA with a known HCV status after January 2001 were classified into strata based on time-updated HCV RNA measurements and HCV treatment, as either HCV antibody–negative; spontaneously resolved HCV; chronic, untreated HCV; cured HCV (HCV RNA–negative); or HCV treatment failures (HCV RNA–positive). Poisson regression was used to compare incidence rates between HCV groups for end-stage liver disease (ESLD; including hepatocellular carcinoma [HCC]), non–acquired immunodeficiency virus defining malignancy (NADM; excluding HCC), and cardiovascular disease (CVD). /
Results:
There were 16 618 persons included (median follow-up 8.3 years, interquartile range 3.1–13.7). There were 887 CVD, 902 NADM, and 436 ESLD events; crude incidence rates/1000 person-years follow-up were 6.4 (95% confidence interval [CI] 6.0–6.9) for CVD, 6.5 (95% CI 6.1–6.9) for NADM, and 3.1 (95% CI 2.8–3.4) for ESLD. After adjustment, there were no differences in incidence rates of NADM or CVD across the 5 groups. HCV-negative individuals (adjusted incidence rate ratio [aIRR] 0.22, 95% CI 0.14–0.34) and those with spontaneous clearance (aIRR 0.61, 95% CI 0.36–1.02) had reduced rates of ESLD compared to cured individuals. Persons with chronic, untreated HCV infections (aIRR 1.47, 95% CI 1.02–2.13) or treatment failure (aIRR 1.80, 95% CI 1.22–2.66) had significantly raised rates of ESLD, compared to those who were cured. /
Conclusions:
Incidences of NADM or CVD were independent of HCV group, whereas those cured had substantially lower incidences of ESLD, underlining the importance of successful HCV treatment for reducing ESLD
- …