1,168 research outputs found

    Characterization of multilayer stack parameters from X-ray reflectivity data using the PPM program: measurements and comparison with TEM results

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    Future hard (10 -100 keV) X-ray telescopes (SIMBOL-X, Con-X, HEXIT-SAT, XEUS) will implement focusing optics with multilayer coatings: in view of the production of these optics we are exploring several deposition techniques for the reflective coatings. In order to evaluate the achievable optical performance X-Ray Reflectivity (XRR) measurements are performed, which are powerful tools for the in-depth characterization of multilayer properties (roughness, thickness and density distribution). An exact extraction of the stack parameters is however difficult because the XRR scans depend on them in a complex way. The PPM code, developed at ERSF in the past years, is able to derive the layer-by-layer properties of multilayer structures from semi-automatic XRR scan fittings by means of a global minimization procedure in the parameters space. In this work we will present the PPM modeling of some multilayer stacks (Pt/C and Ni/C) deposited by simple e-beam evaporation. Moreover, in order to verify the predictions of PPM, the obtained results are compared with TEM profiles taken on the same set of samples. As we will show, PPM results are in good agreement with the TEM findings. In addition, we show that the accurate fitting returns a physically correct evaluation of the variation of layers thickness through the stack, whereas the thickness trend derived from TEM profiles can be altered by the superposition of roughness profiles in the sample image

    Doping and temperature dependence of Mn 3d states in A-site ordered manganites

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    We present a systematic study of the electronic structure in A-site ordered manganites as function of doping and temperature. The energy dependencies observed with soft x-ray resonant diffraction (SXRD) at the Mn L_{2,3} edges are compared with structural investigations using neutron powder diffraction as well as with cluster calculations. The crystal structures obtained with neutron powder diffraction reflect the various orbital and charge ordered phases and show an increase of the Mn-O-Mn bond angle as function of doping and temperature. Cluster calculations show that the observed spectral changes in SXRD as a function of doping are more pronounced than expected from an increase in bandwitdh due to the increase in Mn-O-Mn bond angle, and are best described by holes that are distributed at the neighbouring oxygen ions. These holes are not directly added to the Mn 3d shell, but centered at the Mn site. In contrast, the spectral changes in SXRD as function of temperature are best described by an increase of magnetic correlations. This demonstrates the strong correlations between orbitals and magnetic moments of the 3d states

    Dapoxetine treatment in patients with lifelong premature ejaculation: the reasons of a Waterloo

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    Objective To assess both the acceptance and the discontinuation rates from dapoxetine, the first oral pharmacological agent indicated for the treatment of premature ejaculation (PE). Methods One hundred twenty consecutive potent patients (mean age 40.3 years; range 18-63 years) seeking medical treatment for lifelong PE were enrolled in a prospective phase II study. Moreover, they were assessed regarding detailed medical and sexual history, intravaginal ejaculatory latency time (IELT), International Index of Erectile Function (IIEF), and complete physical examination. The patients received a dapoxetine prescription (30 mg on demand) and unresponded cases received increased dose (60 mg after 3 months). The patients were evaluated at 1, 3, 6, and 12 months, and requested to complete a multiple-choice global assessment questionnaire regarding specific reasons for eventual therapy discontinuation. Results Twenty-four of the patients (20%) decided not to start dapoxetine. Fear of using a "drug" was the most frequently reported reason for treatment nonacceptance (50%) and the cost of treatment was the reason for 25% of the patients. Ninety-six patients (80%) started the therapy. Twenty-six percent dropped out after 1 month, 42.7% dropped out after 3 months, 18.7% dropped out at 6 months, 2% dropped out at 12 months, and 10.4% are continuing the therapy after 1 year. The main reasons were effect below expectations 24.4%, costs 22.1%, side effects 19.8%, loss of interest in sex 19.8%, and no efficacy 13.9%. Conclusion Twenty percent of lifelong PE patients seeking medical treatment for early ejaculation freely decided not to start treatment with dapoxetine, and roughly 90% of the patients who started therapy discontinued after 1 year. �� 2013 Elsevier Inc. All Rights Reserved

    Hydrogen sulphide is involved in testosterone vascular effect

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    BACKGROUND: Testosterone (T) induces a rapid relaxation in vascular tissues of different species due to a nongenomic effect of this steroid on vessels. Different mechanisms have been proposed to explain T-induced vasodilatation but the effective mechanism(s) and the mediators involved are still a matter of debate. OBJECTIVES: We have evaluated if H(2)S pathway is involved in T vascular effects. DESIGN AND SETTING: Male Wistar rats were sacrificed and thoracic aorta was rapidly dissected and cleaned from fat and connective tissue. Rings of 2-3 mm length were cut and placed in organ baths filled with oxygenated Krebs solution at 37 degrees C and mounted to isometric force transducers. H(2)S determination was performed on thoracic aortic rings incubated with T or vehicle and in presence of inhibitors. H2S concentration was calculated against a calibration curve of NaHS (3-250 microM). Results were expressed as nmoles/mg protein. MEASUREMENTS: Vascular reactivity was evaluated by using isometric transducers. H(2)S determination was performed by using a cystathionine beta-synthetase (CBS) and cystathionine gamma lyase (CSE) activity assay. CSE and CBS protein levels were assessed by Western blot analysis. Statistical analysis was performed by using two-way ANOVA and unpaired Student's t-test where appropriate. RESULTS: T significantly increased conversion of L-cysteine to H(2)S. This effect was significantly reduced by PGG and BCA, two specific inhibitors of CSE. T (10 nM-10 microM) induced a concentration-dependent vasodilatation of rat aortic rings in vitro that was significantly and concentration-dependent inhibited by PGG, BCA, and glybenclamide. Incubation of aorta with T up to 1 h did not change CBS/CSE expression, suggesting that T modulates enzymatic activity. CONCLUSIONS: Here we demonstrate that T vasodilator effect involves H(2)S, a novel gaseous mediator. T modulates H(2)S levels by increasing the enzymatic conversion of L-cysteine to H(2)S

    Role of Chlamydia Trachomatis infection in young men : what we need to know?

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    Chlamydia Trachomatis infections are the most common sexually transmitted bacterial infections worldwide: Because Chlamydia Trachomatis infections are asymptomatic in approximately 50% of infected men and 70% of infected women, there is a high risk for reproductive tract sequelae and high diffusion of the disease. Recently some studies improved the comprehension of this infection and its natural history highlighting the fact that severe complications can be avoided only by a proper early diagnosis and appropriate treatment. We reviewed the literature related to the new findings in the treatment of Chlamydia Trachomatis infection in sexually active young men. Articles from 1960-2014 were identified through a Medline search using the keywords "Chlamydia Trachomatis" combined with "urethritis", "epididymitis", "prostatitis" "treatment" or "management". Several studies highlighted that Chlamidia are only metabolically active in the host cell and therefore only targeted intracellularly by antibiotics. However, even if the standard therapy includes intracellularly-accumulated antibiotics such as tetracyclines or macrolides, recent evidences highlight the role of quinolones. In particular recent studies hilight the role of prulifloxacin in the treatment of chronic prostatitis patients for improving patient's quality of life and decreasing the IL-8 level. However, there is a need for future studies and to diffuse the knowledge about Chlamydia Trachomatis especially in urological clinical practice, in order to reduce the risk of diagnosis failure

    The role of flower pollen extract in managing patients affected by chronic prostatitis/chronic pelvic pain syndrome. a comprehensive analysis of all published clinical trials

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    Background: Chronic prostatitis/chronic pelvic pain syndrome (CP/CPPS) is still a challenge to manage for all physicians. We feel that a summary of the current literature and a systematic review to evaluate the therapeutic efficacy of flower pollen extract would be helpful for physicians who are considering a phytotherapeutic approach to treating patients with CP/CPPS. Methods: A comprehensive search of the PubMed and Embase databases up to June 2016 was performed. This comprehensive analysis included both pre-clinical and clinical trials on the role of flower pollen extract in CP/CPPS patients. Moreover, a meta-analysis of available randomized controlled trials (RCTs) was performed. The NIH Chronic Prostatitis Symptom Index (NIH-CPSI) and Quality of Life related questionnaires (QoL) were the most commonly used tools to evaluate the therapeutic efficacy of pollen extract. Results: Pre-clinical studies demonstrated the anti-inflammatory and anti-proliferative role of pollen extract. 6 clinical, non-controlled studies including 206 patients, and 4 RCTs including 384 patients were conducted. The mean response rate in non-controlled studies was 83.6% (62.2%-96.0%). The meta-analysis revealed that flower pollen extract could significantly improve patients’ quality of life [OR 0.52 (0.34-.0.81); p = 0.02]. No significant adverse events were reported. Conclusion: Most of these studies presented encouraging results in terms of variations in NIH-CPSI and QoL scores. These studies suggest that the use of flower pollen extract for the management of CP/CPPS patients is beneficial. Future publications of robust evidence from additional RCTs and longer-term follow-up would provide more support encouraging the use of flower pollen extracts for CP/CPPS patients

    Rome consensus conference-statement: human papilloma virus diseases in males

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    Human Papillomavirus (HPV) is a very resistant, ubiquitous virus that can survive in the environment without a host. The decision to analyse HPV-related diseases in males was due to the broad dissemination of the virus, and, above all, by the need to stress the importance of primary and secondary prevention measures (currently available for women exclusively). The objective of the Consensus Conference was to make evidence-based recommendations that were designed to facilitate the adoption of a standard approach in clinical practice in Italy. METHODS: The Sponsoring Panel put a series of questions to the members of the Scientific Committee who prepared a summary of the currently available information, relevant for each question, after the review and grading of the existing scientific literature. The summaries were presented to a Jury, also called multidisciplinary Consensus Panel, who drafted a series of recommendations. RESULTS: The prevalence of HPV in males ranges between 1.3-72.9%;. The prevalence curve in males is much higher than that in females and does not tend to decline with age. Women appear to have a higher probability of acquiring HPV genotypes associated with a high oncogenic risk, whereas in males the probability of acquiring low- or high-risk genotypes is similar. The HPV-related diseases that affect males are anogenital warts and cancers of the penis, anus and oropharynx. The quadrivalent vaccine against HPV has proved to be effective in preventing external genital lesions in males aged 16-26 years in 90.4%; (95%; CI: 69.2-98.1) of cases. It has also proved to be effective in preventing precancerous anal lesions in 77.5%; (95%; CI: 39.6-93.3) of cases in a per-protocol analysis and in 91.7%; (95%; CI: 44.6-99.8) of cases in a post-hoc analysis. Early ecological studies demonstrate reduction of genital warts in vaccinated females and some herd immunity in males when vaccine coverage is high, although males who have sex with males gained no benefit at all. Males with an immunodeficiency disease are at greater risk of developing disease. Infertility seems to be caused by HPV in some cases. Studies demonstrate vaccination to both genders can be more efficacious and social equity matters are to be taken into consideration. CONCLUSIONS: The Jury made Recommendations based on the scientific evidence presented by the Scientific Committee. Accordingly, for prevention purposes and social fairness and equality, as both sexes are affected by the disease, the vaccination of 12-year-old males against HPV should be recommended in order to guaranty protection to everyone. Aspects related to healthcare policy and economic sustainability, are to be discussed by respective public system representatives. More campaigns to raise awareness through all institutional channels are needed, not only regarding anogenital warts, but for HPV-related diseases in general in males in accordance to new scientific evidences

    Mediterranean Diet as a Shield against Male Infertility and Cancer Risk Induced by Environmental Pollutants: A Focus on Flavonoids

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    The role of environmental factors in influencing health status is well documented. Heavy metals, polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls, dioxins, pesticides, ultrafine particles, produced by human activities put a strain on the body’s entire defense system. Therefore, together with public health measures, evidence-based individual resilience measures are necessary to mitigate cancer risk under environmental stress and to prevent reproductive dysfunction and non-communicable diseases; this is especially relevant for workers occupationally exposed to pollutants and/or populations residing in highly polluted areas. The Mediterranean diet is characterized by a high intake of fruits and vegetables rich in flavonoids, that can promote the elimination of pollutants in tissues and fluids and/or mitigate their effects through different mechanisms. In this review, we collected evidence from pre-clinical and clinical studies showing that the impairment of male fertility and gonadal development, as well as cancers of reproductive system, due to the exposure of organic and inorganic pollutants, may be counteracted by flavonoids

    Magnetic and electronic Co states in layered cobaltate GdBaCo2O5.5-x

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    We have performed non-resonant x-ray diffraction, resonant soft and hard x-ray magnetic diffraction, soft x-ray absorption and x-ray magnetic circular dichroism measurements to clarify the electronic and magnetic states of the Co3+ ions in GdBaCo2O5.5. Our data are consistent with a 3+ Py Co HS state at the pyramidal sites and a 3+ Oc Co LS state at the octahedral sites. The structural distortion, with a doubling of the a axis (2ap x 2ap x 2ap cell), shows alternating elongations and contractions of the pyramids and indicates that the metal-insulator transition is associated with orbital order in the t2g orbitals of the 3+ Py Co HS state. This distortion corresponds to an alternating ordering of xz and yz orbitals along the a and c axes for the 3+ Py Co . The orbital ordering and pyramidal distortion lead to deformation of the octahedra, but the 3+ Oc Co LS state does not allow an orbital order to occur for the 3+ Oc Co ions. The soft x-ray magnetic diffraction results indicate that the magnetic moments are aligned in the ab plane but are not parallel to the crystallographic a or b axes. The orbital order and the doubling of the magnetic unit cell along the c axis support a non-collinear magnetic structure. The x-ray magnetic circular dichroism data indicate that there is a large orbital magnetic contribution to the total ordered Co moment
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