998 resultados para Transdutor de 5 a 10 MHz


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We compared different approaches to analyze running mechanics alterations during repeated treadmill sprints. Thirteen active male athletes performed five 5-second sprints with 25 seconds of recovery on an instrumented treadmill. This approach allowed continuous measurement of running kinetics/kinematics and calculation of vertical and leg stiffness variables that were subsequently averaged over 3 distinct sections of the 5-second sprint (steps 2-5, 7-10, and 12-15) and for all steps (steps 2-15). Independently from the analyzed section, propulsive power and step frequency decreased with fatigue, while contact time and step length increased (P < .05). Except for step frequency, all mechanical variables varied (P < .05) across sprint sections. The only parameters that highly depend on running velocity (propulsive power and vertical stiffness) showed a significant interaction (P < .05) between the analyzed sections, with smaller magnitude of fatigue-induced change observed for steps 2-5. Considering all steps or only a few steps during early, middle, or late phases of 5-second sprints provides similar mechanical outcomes during repeated treadmill sprinting, although acceleration induces noticeable differences between the sections studied. Furthermore, quantifying mechanical alterations from the early acceleration phase may not be readily detectable, and is not recommended.

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Aim: We have previously documented the feasibility of neoadjuvant chemotherapy and EPP in a multicenter trial of MPM (Weder, Ann Oncol 18: 1196, 2007). The objectives of the trimodality trial SAKK17/04 (NCT00334594) were to evaluate the time to loco-regional relapse with or without high dose hemithoracic radiotherapy in a prospective multicenter randomized phase II trial in patients with R0 and R1 resection after neoadjuvant chemotherapy and EPP. Methods: Eligible patients had pathologically confirmed MPM, surgically resectable TNM stage (T1-3 N0-2 M0), PS0-1, ages 18-70 years. Part 1 had a phase II design, and included neoadjuvant chemotherapy with 3 cycles of cisplatin and pemetrexed, followed by restaging and EPP. The primary endpoint of part 1 was complete macroscopic resection (R0-1). Part 2 randomized consenting patients with R0-1 resection into two parallel phase II arms (control arm A and radiotherapy arm B). The primary endpoint for part 2 was loco-regional relapse-free survival (RFS). To detect a 1 year increase with 80% power and 10% alpha, 37 patients were needed for arm B. Secondary endpoints included operability, tolerability of chemotherapy and radiotherapy, survival, and translational research Results: Because accrual of part 2 was slower than planned, the trial was stopped in 2013. Overall, 153 patients entered the trial, of whom 125 underwent surgery and 99 had a complete macroscopic resection (primary endpoint part 1). Of the later patients, 54 could be randomized 1:1 into each arm. Reasons for non-randomization included patient refusal in 24 and ineligibility or protocol deviations in 21. Of the 27 patients randomized to hemithoracic radiotherapy, 25 completed the treatment as planned. For part 1 the median RFS was 8.8 (95%CI: 7.3-10.7) and median OS was 15.0 (95% CI: 12.1-19.3) months. For part 2 the median local RFS for group A was 7.6 (95%CI: 5.5-10.7) and for group B 9.4 (95%CI: 6.5-11.9) months (primary endpoint part 2), while the overall RFS and OS for group A were 5.7 (95%CI: 3.5-8.8) and 16.9 (95%CI: 10.7-23.6) months and for group B 7.6 (95% CI:5.2-10.6) and 14.9 (95%CI: 7.0-17.6) months. Conclusions: This study did not reach the primary endpoint which was defined as one-year increase in loco-regional relapse-free survival and thus does not support the routine use of hemithoracic RT after neoadjuvant chemotherapy and EPP. Disclosure: All authors have declared no conflicts of interest.

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Background: Endometriosis is an estrogen-dependent, pro-inflammatory, pro-angiogenic condition that affects 5 to 10% of women of reproductive age. Its defining feature is the presence of endometrium-like tissue in sites outside the uterine cavity, primarily on the pelvic peritoneum and ovaries. The main clinical features are chronic pain, pain during intercourse and infertility. In patients with endometriosis, inflammatory and immune responses, angiogenesis and apoptosis are altered in favour of the survival and replenishment of endometriotic tissue. These basic pathological processes depend on the excessive formation of estrogen and prostaglandins. Recently, new cellular and molecular mechanisms for the resolution of inflammation have been discovered, revealing key roles for lipid mediators such as lipoxins, resolvins and protectins. It is possible that disequilibrium in the expression of these molecules exists in endometriosis. Objective: To compare the expression of two proteins involved in the synthe sis and in the function of lipid mediators; the Arachidonate 15-lipoxygenase (ALOXI5), implicated in the synthesis of lipoxins A4 and B4 and the Formyl peptide receptor 1 (FPRLI), the specific receptor for Lipoxin A4 and B4, between women who suffer from endometriosis and a control group. We wish to demonstrate the cellular localisation of these two molecules and to investigate if their expression is alteted in this pathology. Methods and Materials Using immunohistochemistry we will compare ALOXI5 and FPRLI staining, in endometrium, normal peritoneum and endometriotic lesions. The samples are being collected in the department of Gynaecology and Obstetrics at the Centre Hospitalier Universitaire Lausanne (CHUV). Women attending the department for laparoscopic investigation of pain/infertility, suspected endometriosis or for a hysterectomy, are invited to participate. Approval of the ethics committee (Commission d'Ethique de la recherché clinique) was obtained in March 2009. Clinical samples will only be obtained from subjects having consented. Expected results and interpretation: No published studies investigating the expression of these two molecules in endometriotic lesions exist. A better understanding of the mechanisms underlying this disease will result in the development of new medical therapies and new diagnostic tests, with the aim of ameliorating the quality of life of endometriosis patients.

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OBJETIVO: Estabelecer os custos dos controles de qualidade para os radiofármacos marcados com [99mTc]tecnécio nos serviços de medicina nuclear do Brasil, em atenção às resoluções RDC nº 38/2008 e RDC nº 63/2009 editadas pela Agência Nacional de Vigilância Sanitária. MATERIAIS E MÉTODOS: Foram apurados preços de materiais de consumo, equipamentos e de mão-de-obra para a realização dos controles de qualidade. Os valores foram convertidos para unidades de volume, tempo e outras unidades cabíveis para a determinação do preço unitário. RESULTADOS: O investimento para aquisição de materiais de consumo e equipamentos foi estimado ser de R$ 35.500,00. O custo final para o controle de cada kit variou entre R$ 6,44 e R$ 7,80, dependendo do produto a ser analisado e do profissional selecionado para execução do procedimento. Esses valores podem representar de 0,5% a 10% do valor recebido pelas instituições pela realização dos exames. Na prática, o custo efetivo pode ser menor, uma vez que o produto de um kit pode ser utilizado em diversos pacientes. CONCLUSÃO: Em face do ganho de qualidade e segurança dos pacientes, concluímos que os custos da implantação do programa de controle de qualidade podem ser absorvidos no planejamento financeiro dos serviços de medicina nuclear.

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Elevated concentrations of albumin in the urine, albuminuria, are a hallmark of diabetic kidney disease and are associated with an increased risk for end-stage renal disease and cardiovascular events. To gain insight into the pathophysiological mechanisms underlying albuminuria, we conducted meta-analyses of genome-wide association studies and independent replication in up to 5,825 individuals of European ancestry with diabetes and up to 46,061 without diabetes, followed by functional studies. Known associations of variants in CUBN, encoding cubilin, with the urinary albumin-to-creatinine ratio (UACR) were confirmed in the overall sample (P = 2.4 × 10(-10)). Gene-by-diabetes interactions were detected and confirmed for variants in HS6ST1 and near RAB38/CTSC. Single nucleotide polymorphisms at these loci demonstrated a genetic effect on UACR in individuals with but not without diabetes. The change in the average UACR per minor allele was 21% for HS6ST1 (P = 6.3 × 10(-7)) and 13% for RAB38/CTSC (P = 5.8 × 10(-7)). Experiments using streptozotocin-induced diabetic Rab38 knockout and control rats showed higher urinary albumin concentrations and reduced amounts of megalin and cubilin at the proximal tubule cell surface in Rab38 knockout versus control rats. Relative expression of RAB38 was higher in tubuli of patients with diabetic kidney disease compared with control subjects. The loci identified here confirm known pathways and highlight novel pathways influencing albuminuria.

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Objective: To analyze standardized uptake values (SUVs) using three different tube current intensities for attenuation correction on 18FNaF PET/CT scans. Materials and Methods: A total of 254 18F-NaF PET/CT studies were analyzed using 10, 20 and 30 mAs. The SUVs were calculated in volumes of interest (VOIs) drawn on three skeletal regions, namely, right proximal humeral diaphysis (RH), right proximal femoral diaphysis (RF), and first lumbar vertebra (LV1) in a total of 712 VOIs. The analyses covered 675 regions classified as normal (236 RH, 232 RF, and 207 LV1). Results: Mean SUV for each skeletal region was 3.8, 5.4 and 14.4 for RH, RF, and LV1, respectively. As the studies were grouped according to mAs value, the mean SUV values were 3.8, 3.9 and 3.7 for 10, 20 and 30 mAs, respectively, in the RH region; 5.4, 5.5 and 5.4 for 10, 20 and 30 mAs, respectively, in the RF region; 13.8, 14.9 and 14.5 for 10, 20 and 30 mAs, respectively, in the LV1 region. Conclusion: The three tube current values yielded similar results for SUV calculation.

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Background. Hepatitis B virus (HBV) is an important cause of chronic viral disease worldwide and can be life threatening. While a safe and effective vaccine is widely available, 5 to 10% of healthy vaccinees fail to achieve a protective anti-hepatitis B surface antigen antibody (anti-HBs) titer (>10mIU/ml). A limited number of studies investigated host genetics of the response to HBV vaccine. To our knowledge, no comprehensive overview of genetic polymorphisms both within and outside the HLA system has been done so far. Aim. The aim of this study was to perform a systematic review of the literature of human genetics influencing immune response after hepatitis B vaccination. Methods. Literature searches using keywords were conducted in the electronic databases Medline, Embase and ISI Web of Science the cut-off date being March 2014. After selection of papers according to stringent inclusion criteria, relevant information was systematically collected from the remaining articles, including demographic data, number of patients, schedule and type of vaccine, phenotypes, genes and single nucleotide polymorphisms (SNPs) genotyping results and their association with immune response to hepatitis B vaccine. Results. The literature search produced a total of 1968 articles from which 46 studies were kept for further analyses. From these studies, data was extracted for 19 alleles from the human leukocyte antigen (HLA) region that were reported as significant at least twice. Among those alleles, 9 were firmly associated with vaccine response outcome (DQ2 [DQB1*02 and DQB1*0201], DR3 [DRB1*03 and DRB1*0301], DR7 [DRB1*07 and DRB1*0701], C4AQ0, DPB1*0401, DQ3, DQB1*06, DRB1*01 and DRB1*13 [DRB1*1301]). In addition, data was extracted for 55 different genes from which 13 extra-HLA genes had polymorphisms that were studied by different group of investigators or by the same group with a replication study. Among the 13 genes allowing comparison, 4 genes (IL-1B, IL-2, IL-4R and IL- 6) revealed no significant data, 6 genes (IL-4, IL-10, IL-12B, IL-13, TNFA, IFNG and TLR2) were explored with inconsistent results and 2 genes (CD3Z and ITGAL) yielded promising results as their association with vaccine response was confirmed by a replication approach. Furthermore, this review produced a list of 46 SNPs from 26 genes that were associated with immune response to vaccine only once, providing novel candidates to be tested in datasets from existing genome-wide association studies (GWAS). Conclusion. To the best of our knowledge, this is the first systematic review of immunogenetic studies of response to hepatitis B vaccine. While this work reassesses the role of several HLA alleles on vaccine response outcome, the associations with polymorphisms in genes outside the HLA region were rather inconsistent. Moreover, this work produced a list of 46 significant SNPs that were reported by a single group of investigators, opening up some interesting possibilities for further research.

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The experimental results for the 2-propanolysis of benzoyl, benzyl, benzene sulphenyl and benzene sulphonyl chlorides obtained by conductimetric technique were compared with estimates for chlorobenzene which is extremely unreactive as an electrophile. We thus obtained the following reactivity sequence: PhSCl>PhCOCl>PhSO2Cl>PhCH2 Cl>PhCl with rate-coefficiente ratios (in the same order): 9.5 x 10(4) : 1: 7.14 x 10-2 : 4.7 x 10-3 : about 10-26. We have discussed these results in specific terms and with the aid of general conclusions which stem from our own classification of electrophiles.

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This paper proposes an experiment to be performed in both instrumental analysis and experimental physical-chemistry curricular disciplines in order to open options to develop challenging basic research activities. Thus the experimental procedures and the results obtained in the preparation of electrodeposited lead dioxide onto graphite and its evaluation as potentiometric sensor for H3O+ and Pb2+ ions, are presented. The data obtained in acid-base titrations were compared with those of the traditional combination glass electrode at the same conditions. Although a linear sub-Nernstian response to free hydrogen ions was observed for the electrodeposited PbO2 electrode, a good agreement was obtained between them. Working as lead(II) sensing electrode, the PbO2 showed a linear sub-Nernstian behavior at total Pb2+ concentrations ranging from 3,5 x 10-4 to 3,0 x 10-2 mol/L in nitrate media. For the redox couple PbO2/Pb(II) the operational slope converges to the theoretical one, as the acidity of the working solution increases.

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Intrauterine growth restriction (IUGR) is one of the leading causes of perinatal mortality and morbidity. Nowadays, this condition is detected in the 3rt and last trimester of gestation when the pathology is already established and success of therapeutic strategies are limited. As the physiopathology of the disease suggests that the problem stems from poor placental implantation, it would be quite advantageous to identify women at increased risk in the first or second trimester of gestation because it then might be possible to offer treatment interventions or at least to establish increased surveillance for high risk pregnancies. Maternal levels of pregnancy-associated plasma protein-A (PAPP-A) and free β human chorionic gonadotropin (free βhCG) has been shown to be effective in first trimester screening for chromosomal abnormalities, primarily trisomies 21, 13 and 18. Previous studies evaluating PAPP-A and free βhCG measured in the first trimester in relation with IUGR have provided conflicting results. Moreover, it has been suggested that black ethnicity is another important predictive factor for fetal growth restriction.Objective: To analyse the association between first trimester serum analytes (PAPP-A and free βhCG) and ethnicity with Intrauterine Growth Restriction.Methods: The study consists in a retrospective cohort, including all singleton pregnancies with complete outcome data that had undergone first trimester screening (PAPP-A and free βhCG) at 11-13+6weeks of gestation between 1/1/2010 - 31/12/2012 in Hospital Universitari Dr Josep Trueta. Biochemical markers are converted to multiples of the median (MoMs) and percentiles 5 and 10 are calculated. The association between free βhCG and PAPP-A with the incidence of IUGR is evaluated in combination with maternal ethnicity. Bivariate and logistic regression analyses are performed to adjust this association for co variables

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The solubility product value of SrO has been found to be equal to 10-4,2 (molality scale) in molten equimolar mixture of NaCl and KCl at 727ºC, using a potentiometric method involving a calcia stabilized zirconia membrane electrode. This value, which is in a logical agreement with other alkaline-earth oxide determined solubilities, is compared to those of 10-5,8, 10-3,0 and 10-3,08 (molality scale) found in the litterature 33, 22 and 5 years ago, respectively. Such discrepencies have called the attention of the authors, their possible reasons (methodology, titrating agent) are analyzed and a theoretical discussion, for considering the authors' value as more reliable, is given in this paper.

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Phenil glycidyl ether (PGE), a monofunctional diluent, has been used in epoxy resins formulations in order to increase the toughness of the epoxy molded composite. In a systematic study concerning its influence in the cure kinetics of the epoxy resin, it was used in concentrations of 2,5; 5,0; 10 and 20% in relation to a diglycidyl ether bisphenol-A (DGEBA)/diamino diphenil-sulfone (DDS) base matrix. Dynamic and isothermal scanning analysis were carried out using a differential scanning calorimety (DSC) equipment. For all the concentrations of PGE, a n order kinetics was observed, with n varing between 0,35 -- 0,91 as a function of the increase in the PGE concentration.

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A capillary microtrap thermal desorption module is developed for near real-time analysis of volatile organic compounds (VOCs) at sub-ppbv levels in air samples. The device allows the direct injection of the thermally desorbed VOCs into a chromatographic column. It does not use a second cryotrap to focalize the adsorbed compounds before entering the separation column so reducing the formation of artifacts. The connection of the microtrap to a GC–MS allows the quantitative determination of VOCs in less than 40 min with detection limits of between 5 and 10 pptv (25 °C and 760 mmHg), which correspond to 19–43 ng m−3, using sampling volumes of 775 cm3. The microtrap is applied to the analysis of environmental air contamination in different laboratories of our faculty. The results obtained indicate that most volatile compounds are easily diffused through the air and that they also may contaminate the surrounding areas when the habitual safety precautions (e.g., working under fume hoods) are used during the manipulation of solvents. The application of the microtrap to the analysis of VOCs in breath samples suggest that 2,5-dimethylfuran may be a strong indicator of a person's smoking status

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A simple flow injection procedure was developed for determining dipyrone (1-phenyl-2,3-dimethyl-4-methylaminomethano-5-pyrazolone sodium, metamizol, analgin) in pharmaceutical formulations. The determination is based on the reduction of Ag+ ions to Ag0 by dipyrone. A colloidal suspension of Ag0 produced was transported by carrier solution (0.01 mol L-1 NaOH) and turbidimetrically detected at 425 nm. The analytical curve for dipyrone was linear in the range from 5.0 x 10-4 to 2.5 x 10-3 mol L-1 with a correlation coefficient of 0.9990. The detection limit was 1.3 x 10-4 mol L-1 (3sigmaB/slope). The relative standard deviation for ten successive measurements was 1.8% and an analytical frequency of 45 h-1 was obtained. The recovery values from three samples ranged from 96.0 to 102%.

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Pilocarpus riedelianus was studied in order to obtain compounds with activity against fungi and bacteria. The dichloromethane extract, the most active one, was chromatographed yielding hexane and dichloromethane fractions. Six known sesquiterpenes, alpha-calacorene, beta-calacorene, gamma-calacorene, cadalene, sesquichamaenol and 1-hydroxy-1,3,5-bisabolatrien-10-one were identified in the hexane fractions. The identification of these compound was done by NMR and GC/MS analyses. The hexane fraction from the dichloromethane extract showed activity against several fungi and bacteria.