351 research outputs found

    Attosecond Streaking in the Water Window: A New Regime of Attosecond Pulse Characterization

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    We report on the first streaking measurement of water-window attosecond pulses generated via high harmonic generation, driven by sub-2-cycle, CEP-stable, 1850 nm laser pulses. Both the central photon energy and the energy bandwidth far exceed what has been demonstrated thus far, warranting the investigation of the attosecond streaking technique for the soft X-ray regime and the limits of the FROGCRAB retrieval algorithm under such conditions. We also discuss the problem of attochirp compensation and issues regarding much lower photo-ionization cross sections compared with the XUV in addition to the fact that several shells of target gases are accessed simultaneously. Based on our investigation, we caution that the vastly different conditions in the soft X-ray regime warrant a diligent examination of the fidelity of the measurement and the retrieval procedure.Comment: 14 Pages, 12 figure

    Meissner to vortex phase transition in a two-leg ladder in artificial gauge field

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    International audienceWe consider a two-leg boson ladder in artificial gauge field with hard-core intraleg and negligible interleg interactions. Using numerical simulations based on the Density Matrix Renormalization Group (DMRG) algorithm, combined with a bosonization approach, we study its commensurate-incommensurate transition to a vortex phase at a critical flux. We discuss the finite-size scaling behavior of the longitudinal current near the transition. For weak interchain bo-son hopping, the finite size scaling is in agreement with the predictions from bosonization

    Smoking Cessation on Periodontal and Peri-Implant Health Status: A Systematic Review

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    Since smoking is considered among the main risk factors for the onset and progression of periodontitis and peri-implantitis, the present systematic review aimed to evaluate the effect of smoking cessation on clinical, radiographic, and gingival crevicular periodontal parameters around natural teeth and dental implants in ex-smokers compared to current and non-smokers. The study protocol was developed based on the PRISMA guidelines, the research question was formulated according to the PICO model, and the literature search was conducted through PubMed/MEDLINE, Cochrane library, and BioMed Central databases. From the 916 title/abstracts initially identified, seven articles were included in the present systematic review and assessed for quality through the ROBINS-I tool. Reported findings on clinical and crevicular periodontal parameters around natural teeth were contrasting when comparing ex-smokers to current and non-smokers; thus, individualized recommendations for previous smoker periodontal patients are currently lacking. No data on radiographic parameters were retrieved. Similarly, data on periodontal parameters around dental implants were not available, highlighting the need for focused investigations assessing the role of both smoking habit and cessation on peri-implant health status and responsiveness to treatment

    Levelized Cost of Heat for Linear Fresnel Concentrated Solar Systems

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    In this paper, a deep investigation upon levelized cost of heat (LCOH) produced by small-scale solar linear concentrating Fresnel collectors (CSLFC) is proposed. Solar industrial process heat applications have temperature requirements from about 60 °C to 260 °C. CSLFCs can effectively integrate conventional fossil fuel thermal systems. The study is addressed to assess technology cost projection needed to achieve competitive LCOH. So, on the basis of a framework specifically developed for these economic assessments, the best investment scenarios, in terms of industrial application, geographical location and technical design solutions, where to effectively apply the technology of CSLFC, are highlighted. The analysis has been focused on specific cost of several existing CSLFCs associated with declared performances at different operating temperatures. Two main classes of CSLFC with different total efficiency (optical and thermal) corresponding to various design solutions and specific cost were selected. The expected performances in the whole application temperature range have been evaluated through Glayx Tech proprietary simulation code, including optical and thermal unsteady analysis. A huge database coming from full CSLFC simulation varying latitude, yearly DNI, operating fluid, outlet temperature, thermal storage options, has been collected. CLSFC design and performance requirements are the key-choice to achieve competitive LCOH: the use of high efficiency – high cost components is not always rewarding in terms of final LCOH and must be attentively decided basing on site, irradiation, heat quality and LCOH target. In this perspective, CLSFCs are the most promising for industrial small scale heat applications since they show the greatest potential to reduce manufacturing costs

    Reproductive disorders induced by Chlamydophila spp. infections in an italian mediterranean buffalo (bubalus bubalis) herd

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    The Italian Mediterranean Buffalo (Bubalus bubalis) has low fecundity and high incidence of abortion. Several studies have associated reproductive failure of water buffalo with viral infections but there is limited information on the role of chlamydial infections. To investigate the presence and the role of Chlamydiaceae in water buffalo a retrospective study was performed in a farm where, in the arch of 11 months, the pregnant heifers suffered an abortion rate of 36.8% in the 3rd and 5th month of pregnancy. Antibodies to Chlamydiaceae were detected in 57% of the aborted cows, while the rate of positivity was 0% in overtly healthy cows used as control. By a PCR assay 3 of 14 vaginal swabs from aborted animals tested positive for Chlamydophila agents and, additionally, 3 out of 7 aborted foetuses tested positive for Chlamydophila spp., with two being co-infections by Cp. abortus and Cp. pecorum and one being characterised as Cp. abortus. The presence of anti-Chlamydiaceae antibodies in 57% of the aborted animals and the detection of Chlamydophila agents in foetal organs and in vaginal swabs is consistent with the history of abortions (P<0.002) observed in the herd and may suggest a pathogenic role by Chlamydophila spp. in water buffalo

    Estimation of buffalo cheese yield by using the chemical-physical parameters of the milk

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    The aim of this study was to estimate cheese yield by using the chemical- physical parameters of the milk. Analysis were performed on 325 milk samples with 80-219 days in milk interval. Furthermore, buffaloes which showed a ratio between theoretical cheese yield (calculated by Altiero formula) and real cheese yield at 28 hours higher (Group A) or lower (Group B) than 0.983, were compared taking into account 5 hypothetical analytical potentialities of laboratories: 1) Fat percentage; 2) Protein and fat percentages; 3) Protein and fat percentages, pH and SH; 4) Protein and fat percentages, pH, SH, urea, protein percentage corrected per urea, lactose, solids-not-fat (SNF) and SCC; 5) Protein and fat percentages, pH, SH, urea, protein percentage corrected per urea, lactose, SNF, SCC, TAMF, milk DM percentage, ash percentage and casein percentage. Correlation and regression analyses with stepwise method were performed for curd quantity in relation to the physic-chemical ad microbiological milk composition by using SPSS 15.0. As expected, R2 value was such high as the number of variables included in the calculation. A higher R2 value was observed in those samples characterized by a ThCY/28CY ratio < 0.983. ThCY calculated according to Altiero et al (1989), underestimated 28CY of +1.8 g/litre in all samples, whereas a difference between –2.2 (Laboratory 2) and +1.0 (Laboratory 3) g/litre was registered if the actual formula is utilized. According to Altiero formula, 28CY was overestimated of 9.6 g/litre in Group A, whereas it was underestimated of 1.8 g/litre in Group B. According to our study, the estimation of 28CY showed a difference between –9.3 (Laboratory 2) and 9 (Laboratory 1) g/litre in Group A and – 3.5 (Laboratory 1) e 0.0 (Laboratory 5) g/litre

    Effects of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 in IBS patients

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    Background: Irritable bowel syndrome (IBS) is a common gastrointestinal disorder, which still lacks effective therapy. We aimed to investigate the effects of a novel formulation of Bifidobacterium longum BB536 and Lactobacillus rhamnosus HN001 with vitamin B6 (LBB) on symptoms, intestinal permeability, cultivable bacteria and metabolome in IBS subjects. Materials and methods: Twenty-five IBS patients (Rome IV criteria) (M:F&nbsp;=&nbsp;8:17; age 48&nbsp;years&nbsp;±&nbsp;11 SD) were randomized to treatment (LBB) or placebo (one month each) in a crossover randomized double-blind controlled trial. Symptoms, intestinal habits, disease severity, intestinal permeability and intestinal microbiota were analysed at 0, 30, 45 and 60&nbsp;days. Results: Percentage decrease from baseline of abdominal pain (−48.8% vs −3.5%), bloating (−36.35% vs +7.35%) and severity of disease (−30.1% vs −0.4%) was significantly (P&nbsp;&lt;.0001) greater with LBB than placebo, respectively. In IBS-D patients, the improvement from baseline of Bristol score was more consistent with LBB (from 6&nbsp;±&nbsp;0.4 to 4.3&nbsp;±&nbsp;1.1, P&nbsp;&lt;.00001) than placebo (from 6.2&nbsp;±&nbsp;0.7 to 5.3&nbsp;±&nbsp;1.1, P&nbsp;=.04). In IBS-C patients, Bristol score tended to improve from baseline after LBB (2.6&nbsp;±&nbsp;1.1 vs 3.2&nbsp;±&nbsp;0.5, P&nbsp;=.06). LBB significantly improved the percentage of sucralose recovery (colonic permeability) (1.86&nbsp;±&nbsp;0.1 vs 1.1&nbsp;±&nbsp;0.2, P&nbsp;=.01). During treatment, presumptive lactic acid bacteria and bifidobacteria, relative abundance of propanoic, butanoic, pentanoic acids and hydrocarbons increased, while phenol decreased. Conclusions: The novel formulation of B. longum BB536 and L. rhamnosus HN001 with B6 vitamin improves symptoms and severity of disease, restores intestinal permeability and gut microbiota in IBS patients

    Effect of lifestyle changes on erectile dysfunction in obese men: a randomized controlled trial

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    Context: Healthy lifestyle factors are associated with maintenance of erectile function in men. Objective: To determine the effect of weight loss and increased physical activity on erectile and endothelial functions in obese men. Design, Setting, and Patients: Randomized, single-blind trial of 110 obese men (body mass index ≥30) aged 35 to 55 years, without diabetes, hypertension, or hyperlipidemia, who had erectile dysfunction that was determined by having a score of 21 or less on the International Index of Erectile Function (IIEF). The study was conducted from October 2000 to October 2003 at a university hospital in Italy. Interventions: The 55 men randomly assigned to the intervention group received detailed advice about how to achieve a loss of 10% or more in their total body weight by reducing caloric intake and increasing their level of physical activity. Men in the control group (n=55) were given general information about healthy food choices and exercise. Main Outcomes Measures: Erectile function score, levels of cholesterol and tryglycerides, circulating levels of interleukin 6, interleukin 8, and C-reactive protein, and endothelial function as assessed by vascular responses to L-arginine. Results: After 2 years, body mass index decreased more in the intervention group (from a mean [SD] of 36.9 [2.5] to 31.2 [2.1]) than in the control group (from 36.4 [2.3] to 35.7 [2.5]) (P<.001), as did serum concentrations of interleukin 6 (P=.03), and C-reactive protein (P=.02). The mean (SD) level of physical activity increased more in the intervention group (from 48 [10] to 195 [36] min/wk; P<.001) than in the control group (from 51 [9] to 84 [28] min/wk; P<.001). The mean (SD) IIEF score improved in the intervention group (from 13.9 [4.0] to 17 [5]; P<.001), but remained stable in the control group (from 13.5 [4.0] to 13.6 [4.1]; P=.89). Seventeen men in the intervention group and 3 in the control group (P=.001) reported an IIEF score of 22 or higher. In multivariate analyses, changes in body mass index (P=.02), physical activity (P=.02), and C-reactive protein (P=.03) were independently associated with changes in IIEF score. Conclusion: Lifestyle changes are associated with improvement in sexual function in about one third of obese men with erectile dysfunction at baseline

    Higher reliability of 18F-FDG target background ratio compared to standardized uptake value in vulnerable carotid plaque detection: a pilot study.

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    Objective: To evaluate the role of [18F]-fluorodeoxyglucose positron emission tomography/computer tomography [18F-FDG PET/CT] comparing target background ratio (TBR) and standardized uptake value (SUV) with the histopathological inflammatory status of the carotid plaques. Background: Vulnerable carotid plaques are the primary cause of acute cerebrovascular events. 18F-FDG PET/CT represents a morpho-functional technique able to identify the highly inflamed and most vulnerable carotid plaques. Several literature studies experimented this new method to identify vascular inflammation, but few have effectively compared PET/CT results with plaque histological data and no studies had directly compared TBR to SUV. Methods: Thirty-two consecutive patients (20 men and 12 women, mean age 74 ± 8 years) undergoing carotid endarterectomy were enrolled and studied with carotid 18F-FDG PET/CT. Maximum and mean SUV and TBR were used to quantify 18F-FDG uptake while surgical specimens were analyzed by optical microscopy to identify inflamed carotid plaques, with evaluation of macrophages infiltration by mean of immunohistochemistry. On the basis of the presence of inflammation at the histological analysis, we divided population in two groups: group A (n = 12) patients with inflamed carotid plaques and group B (n = 20) patients with non-inflamed ones, then crossed and evaluated the histological data with 18F-FDG PET/CT findings. Results: SUV max and SUV mean values resulted higher in group A (respectively, 2.14 ± 0.77 and 1.99 ± 0.68) than in group B (respectively, 1.79 ± 0.37 and 1.64 ± 0.34) without reaching a statistical significance (p = ns). TBR max and TBR mean values resulted higher in group A (respectively, 1.42 ± 0.32 and 1.34 ± 0.26) than in group B (respectively, 1.16 ± 0.19 and 1.03 ± 0.20) with a statistically significant differences between the two groups and carotid inflammation (respectively, p < 0.01 and p < 0.001). Conclusion: TBR (max and mean values) is a more reliable parameter than SUV in identifying inflamed plaques. Although limited by the small population analyzed, our results suggest the important role of 18F-FDG PET/CT, using TBR, in identification of high-risk carotid atherosclerotic plaques. © 2014 The Japanese Society of Nuclear Medicine
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