944 resultados para Tecnécio Tc 99m sestamibi


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In the previous Comment, Forker and co-workers claim that perturbed angular correlation (PAC) data leave no alternative to the conclusion that the spontaneous magnetization of PrCo2 and NdCo2 undergoes a discontinuous, first-order phase transition at TC. We show here that their claim is in clear contradiction with a wealth of experimental evidence, including our own. Finally, we propose a possible origin for the disagreement between their interpretation of the PAC results and the literature on this subject.

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The application of organic residues to the soil can increase soluble organic carbon (SOC) and affect the pH and electrolytic conductivity (EC) of the soil. However, the magnitude of these changes depends on the type of residue and the applied dose. This study aimed to evaluate the effect of increasing C rates contained in organic residue on the pH, EC, water-extractable total carbon (WETC), water-extractable organic carbon (WEOC), and water-extractable inorganic carbon (WEIC) in soil treated with manure (chicken, swine, and quail), sawdust, coffee husk, and sewage sludge. The levels of total C (TC- KH2PO4), organic carbon (OC- KH2PO4), and inorganic C (IC- KH2PO4) extractable by a 0.1 mol L-1 KH2PO4 solution were also quantified in soil under the effect of increasing rates of chicken and quail manures. The following rates of organic residue C were applied to a dystrophic Red Latosol (Oxisol) sample: 0, 2,000, 5,000, 10,000, and 20,000 mg kg-1. The addition of organic residues to the soil increased pH, except in the case of sewage sludge, which acidified the soil. The acidity correction potential of chicken and quail manure was highest, dependent on the manure rate applied; regardless of the dose used, sawdust barely alters the soil pH. At all tested rates, the EC of the soil treated with swine manure, coffee husk, and sawdust remained below 2.0 dS m-1, which is a critical level for salinity-sensitive crops. However, the application of chicken or quail manure and sewage sludge at certain rates increased the EC to values above this threshold level. Highest levels of WETC, WEOC, and WEIC were obtained when chicken and quail manure and coffee husk were applied to the Oxisol. The quantities of SOC extracted by KH2PO4 were higher than the quantities extracted by water, demonstrating the ability of soil to adsorb C into its colloids.

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The Division of Criminal and Juvenile Justice Planning (CJJP) recently released an evaluation of the intensive substance abuse treatment program at the Iowa Correctional Institution for Women (ICIW) – STAR (Sisters Together Achieving Recovery). STAR is a licensed inpatient program utilizing a genderbased therapeutic community model (TC).

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Magnetic-relaxation measurements of a Tl-based high-Tc superconductor show temperature-independent flux creep below 6 K. The effect is analyzed in terms of the overdamped quantum diffusion of two-dimensional vortices. Good agreement between theory and experiment is found.

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OBJECTIVE: To describe the determinants of self-initiated smoking cessation of duration of at least 6 months as identified in longitudinal population-based studies of adolescent and young adult smokers. METHODS: A systematic search of the PubMed and EMBASE databases using smoking, tobacco, cessation, quit and stop as keywords was performed. Limits included articles related to humans, in English, published between January 1984 and August 2010, and study population aged 10-29 years. A total of 4502 titles and 871 abstracts were reviewed independently by 2 and 3 reviewers, respectively. Nine articles were retained for data abstraction. Data on study location, timeframe, duration of follow-up, number of data collection points, sample size, age/grade of participants, number of quitters, smoking status at baseline, definition of cessation, covariates and analytic method were abstracted from each article. The number of studies that reported a statistically significant association between each determinant investigated and cessation were tabulated, from among all studies that assessed the determinant. RESULTS: Despite heterogeneity in methods across studies, five factors robustly predicted quitting across studies in which the factor was investigated: not having friends who smoke, not having intentions to smoke in the future, resisting peer pressure to smoke, being older at first use of cigarette and having negative beliefs about smoking. CONCLUSIONS: The literature on longitudinal predictors of cessation in adolescent and young adult smokers is not well developed. Cessation interventions for this population will remain less than optimally effective until there is a solid evidence base on which to develop interventions.

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Magnetic interactions in ionic solids are studied using parameter-free methods designed to provide accurate energy differences associated with quantum states defining the Heisenberg constant J. For a series of ionic solids including KNiF3, K2NiF4, KCuF3, K2CuF4, and high- Tc parent compound La2CuO4, the J experimental value is quantitatively reproduced. This result has fundamental implications because J values have been calculated from a finite cluster model whereas experiments refer to infinite solids. The present study permits us to firmly establish that in these wide-gap insulators, J is determined from strongly local electronic interactions involving two magnetic centers only thus providing an ab initio support to commonly used model Hamiltonians.

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The magnetic coupling constant of selected cuprate superconductor parent compounds has been determined by means of embedded cluster model and periodic calculations carried out at the same level of theory. The agreement between both approaches validates the cluster model. This model is subsequently employed in state-of-the-art configuration interaction calculations aimed to obtain accurate values of the magnetic coupling constant and hopping integral for a series of superconducting cuprates. Likewise, a systematic study of the performance of different ab initio explicitly correlated wave function methods and of several density functional approaches is presented. The accurate determination of the parameters of the t-J Hamiltonian has several consequences. First, it suggests that the appearance of high-Tc superconductivity in existing monolayered cuprates occurs with J/t in the 0.20¿0.35 regime. Second, J/t=0.20 is predicted to be the threshold for the existence of superconductivity and, third, a simple and accurate relationship between the critical temperatures at optimum doping and these parameters is found. However, this quantitative electronic structure versus Tc relationship is only found when both J and t are obtained at the most accurate level of theory.

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We report the first example of a transition to long-range magnetic order in a purely dipolarly interacting molecular magnet. For the magnetic cluster compound Mn6O4Br4(Et2dbm)6, the anisotropy experienced by the total spin S=12 of each cluster is so small that spin-lattice relaxation remains fast down to the lowest temperatures, thus enabling dipolar order to occur within experimental times at Tc=0.16 K. In high magnetic fields, the relaxation rate becomes drastically reduced and the interplay between nuclear- and electron-spin lattice relaxation is revealed.

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In July of 2009, the Division of Criminal and Juvenile Justice Planning (CJJP) received Byrne Justice Assistance Grant/American Recovery and Reinvestment Act funding from the Governor’s Office of Drug Control Policy to conduct a process and outcome evaluation of the STAR (Sisters Together Achieving Recovery) program housed at the Iowa Correctional Institution for Women (ICIW) in Mitchellville, Iowa. The STAR Program is a licensed inpatient substance abuse treatment program that utilizes a Therapeutic Community model (TC). All offenders exiting the STAR program between October 1, 2004 and June 30, 2008 were included in the study (n=173). A comparison sample was drawn of offenders exiting the ICIW during the same release time frame with identified but untreated substance abuse needs (n= 173). March 31, 2010 was designated as the cut-off date for the study. This yielded an average post-program follow-up time of 3.1 years. The STAR group was further divided into two groups by time of program exit. Participants exiting the program between October 1, 2004 and June 30, 2006 were designated as STAR 1 (n=78) and those exiting the program between July 1, 2006 and June 30, 2008 were designated as STAR 2 (n=95). In order to have comparable tracking time between STAR groups, tracking time for STAR 1 concluded July 31, 2008. This yielded an average post release follow-up time of 2.4 years for both groups. Demographic, Program, Intervention, and Outcome data were examined. Comparisons were made between groups as well as categories of participation.

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We conducted a genome-wide scan using variance components linkage analysis to localize quantitative-trait loci (QTLs) influencing triglyceride (TG), high density lipoprotein-cholesterol (HDL-C), low density lipoprotein-cholesterol, and total cholesterol (TC) levels in 3,071 subjects from 459 families with atherogenic dyslipidemia. The most significant evidence for linkage to TG levels was found in a subset of Turkish families at 11q22 [logarithm of the odds ratio (LOD)=3.34] and at 17q12 (LOD=3.44). We performed sequential oligogenic linkage analysis to examine whether multiple QTLs jointly influence TG levels in the Turkish families. These analyses revealed loci at 20q13 that showed strong epistatic effects with 11q22 (conditional LOD=3.15) and at 7q36 that showed strong epistatic effects with 17q12 (conditional LOD=3.21). We also found linkage on the 8p21 region for TG in the entire group of families (LOD=3.08). For HDL-C levels, evidence of linkage was identified on chromosome 15 in the Turkish families (LOD=3.05) and on chromosome 5 in the entire group of families (LOD=2.83). Linkage to QTLs for TC was found at 8p23 in the entire group of families (LOD=4.05) and at 5q13 in a subset of Turkish and Mediterranean families (LOD=3.72). These QTLs provide important clues for the further investigation of genes responsible for these complex lipid phenotypes. These data also indicate that a large proportion of the variance of TG levels in the Turkish population is explained by the interaction of multiple genetic loci.

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Multisensory and sensorimotor integrations are usually considered to occur in superior colliculus and cerebral cortex, but few studies proposed the thalamus as being involved in these integrative processes. We investigated whether the organization of the thalamocortical (TC) systems for different modalities partly overlap, representing an anatomical support for multisensory and sensorimotor interplay in thalamus. In 2 macaque monkeys, 6 neuroanatomical tracers were injected in the rostral and caudal auditory cortex, posterior parietal cortex (PE/PEa in area 5), and dorsal and ventral premotor cortical areas (PMd, PMv), demonstrating the existence of overlapping territories of thalamic projections to areas of different modalities (sensory and motor). TC projections, distinct from the ones arising from specific unimodal sensory nuclei, were observed from motor thalamus to PE/PEa or auditory cortex and from sensory thalamus to PMd/PMv. The central lateral nucleus and the mediodorsal nucleus project to all injected areas, but the most significant overlap across modalities was found in the medial pulvinar nucleus. The present results demonstrate the presence of thalamic territories integrating different sensory modalities with motor attributes. Based on the divergent/convergent pattern of TC and corticothalamic projections, 4 distinct mechanisms of multisensory and sensorimotor interplay are proposed.

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Cervical cancer, the second leading cause of cancer mortality in women worldwide, results from infection with a subset of human papillomaviruses (HPV), HPV-16 being the most prevalent type. The available prophylactic vaccines are an effective strategy to prevent this cancer in the long term. However, they only target 70-80% of all cervical cancers and cannot control existing HPV infections and associated lesions. Therapeutic vaccines are thus necessary for women who cannot benefit from prophylactic vaccination. Induction of protective immune responses in the genital mucosa (GM) may be crucial for efficacy of HPV therapeutic vaccines. We report here that mice that received a single subcutaneous (s.c.) vaccination of an adjuvanted long synthetic HPV16 E7(1-98) polypeptide showed induction of 100% tumor protection against s.c. TC-1 tumors and that tumor regression was mainly provided by CD8 T cells. In vivo cytotoxic assay revealed high E7-specific cytolytic T lymphocytes activity in spleen and in genital draining lymph nodes (LN), and E7-specific CD8 T cells could be detected in GM by tetramer staining. More importantly, high-avidity E7-specific INF-gamma secreting CD8 T cells were induced not only in blood, spleen and LN but also in GM of vaccinated mice, thus providing evidence that a parenteral vaccination may be sufficient to provide regression of genital tumors. In addition, there was no correlation between the responses measured in blood with those measured in GM, highlighting the necessity and relevance to determine the immune responses in the mucosa where HPV-tumors reside.

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OBJECTIVE: To examine the incremental cost effectiveness of the five first line pharmacological smoking cessation therapies in the Seychelles and other developing countries. DESIGN: A Markov chain cohort simulation. SUBJECTS: Two simulated cohorts of smokers: (1) a reference cohort given physician counselling only; (2) a treatment cohort given counselling plus cessation therapy. INTERVENTION: Addition of each of the five pharmacological cessation therapies to physician provided smoking cessation counselling. MAIN OUTCOME MEASURES: Cost per life-year saved (LYS) associated with the five pharmacotherapies. Effectiveness expressed as odds ratios for quitting associated with pharmacotherapies. Costs based on the additional physician time required and retail prices of the medications. RESULTS: Based on prices for currently available generic medications on the global market, the incremental cost per LYS for a 45 year old in the Seychelles was 599 US dollars for gum and 227 dollars for bupropion. Assuming US treatment prices as a conservative estimate, the incremental cost per LYS was significantly higher, though still favourable in comparison to other common medical interventions: 3712 dollars for nicotine gum, 1982 dollars for nicotine patch, 4597 dollars for nicotine spray, 4291 dollars for nicotine inhaler, and 1324 dollars for bupropion. Cost per LYS increased significantly upon application of higher discount rates, which may be used to reflect relatively high opportunity costs for health expenditures in developing countries with highly constrained resources and high overall mortality. CONCLUSION: Pharmacological cessation therapy can be highly cost effective as compared to other common medical interventions in low mortality, middle income countries, particularly if medications can be procured at low prices.

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OBJECTIVE: This systematic review and meta-analysis of randomized controlled trials (RCTs) assesses the effect of pharmacist care on cardiovascular disease (CVD) risk factors among outpatients with diabetes. RESEARCH DESIGN AND METHODS: MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials were searched. Pharmacist interventions were classified, and a meta-analysis of mean changes of blood pressure (BP), total cholesterol (TC), LDL cholesterol, HDL cholesterol, and BMI was performed using random-effects models. RESULTS: The meta-analysis included 15 RCTs (9,111 outpatients) in which interventions were conducted exclusively by pharmacists in 8 studies and in collaboration with physicians, nurses, dietitians, or physical therapists in 7 studies. Pharmacist interventions included medication management, educational interventions, feedback to physicians, measurement of CVD risk factors, or patient-reminder systems. Compared with usual care, pharmacist care was associated with significant reductions for systolic BP (12 studies with 1,894 patients; -6.2 mmHg [95% CI -7.8 to -4.6]); diastolic BP (9 studies with 1,496 patients; -4.5 mmHg [-6.2 to -2.8]); TC (8 studies with 1,280 patients; -15.2 mg/dL [-24.7 to -5.7]); LDL cholesterol (9 studies with 8,084 patients; -11.7 mg/dL [-15.8 to -7.6]); and BMI (5 studies with 751 patients; -0.9 kg/m(2) [-1.7 to -0.1]). Pharmacist care was not associated with a significant change in HDL cholesterol (6 studies with 826 patients; 0.2 mg/dL [-1.9 to 2.4]). CONCLUSIONS: This meta-analysis supports pharmacist interventions-alone or in collaboration with other health care professionals-to improve major CVD risk factors among outpatients with diabetes.