Heat treatment influence on the superconducting properties of nanometric-scale Nb(3)Sn wires with Cu-Sn artificial pinning centers

Since the discovery of Nb(3)Sn superconductors many efforts have been expended to improve the transport properties in these materials. In this work, the heat treatment profiles for Nb(3)Sn superconductor wires with Cu(Sn) artificial pinning centers (APCs) with nanometric-scale sizes were analyzed in an attempt to improve the critical current densities and upper critical magnetic field. The methodology to optimize the heat treatment profiles in respect to the diffusion, reaction and formation of the superconducting phases is described. Microstructural characterization, transport and magnetic measurements were performed in an attempt to relate the microstructure to the pinning mechanisms acting in the samples. It was concluded that the maximum current densities occur due to normal phases (APCs) that act as the main pinning centers in the global behavior of the Nb(3)Sn superconducting wire. The APC technique was shown to be very powerful because it permitted mixing of the pinning mechanism. This achievement was not possible in other studies in Nb(3)Sn wires reported up to now.

Superhyperfine interactions in inhomogeneously broadened paramagnetic centers observed via a hole-burned free induction decay

Superhyperfine interactions in inhomogeneously broadened paramagnetic centers are observed using a single high-turn-angle microwave pulse. The free induction signal that follows the hole-burning pulse exhibits oscillations that are distinct from the oscillatory free induction decay observable in some inhomogeneously broadened systems. It contains frequencies characteristic of the superhyperfine splittings, together with a zero frequency component. Experimental examples of the effect in both orientationally disordered (powdered) and structurally disordered (glassy) systems are presented and compared with the conceptually similar Fourier transform electron paramagnetic resonance detected nuclear magnetic resonance experiment, together with numerical simulations. (C) 2003 American Institute of Physics.

Diagnostic Performance of Coronary Angiography by 64-Row CT

Background: The accuracy of multidetector computed tomographic (CT) angiography involving 64 detectors has not been well established. Methods: We conducted a multicenter study to examine the accuracy of 64-row, 0.5-mm multidetector CT angiography as compared with conventional coronary angiography in patients with suspected coronary artery disease. Nine centers enrolled patients who underwent calcium scoring and multidetector CT angiography before conventional coronary angiography. In 291 patients with calcium scores of 600 or less, segments 1.5 mm or more in diameter were analyzed by means of CT and conventional angiography at independent core laboratories. Stenoses of 50% or more were considered obstructive. The area under the receiver-operating-characteristic curve (AUC) was used to evaluate diagnostic accuracy relative to that of conventional angiography and subsequent revascularization status, whereas disease severity was assessed with the use of the modified Duke Coronary Artery Disease Index. Results: A total of 56% of patients had obstructive coronary artery disease. The patient-based diagnostic accuracy of quantitative CT angiography for detecting or ruling out stenoses of 50% or more according to conventional angiography revealed an AUC of 0.93 (95% confidence interval [CI], 0.90 to 0.96), with a sensitivity of 85% (95% CI, 79 to 90), a specificity of 90% (95% CI, 83 to 94), a positive predictive value of 91% (95% CI, 86 to 95), and a negative predictive value of 83% (95% CI, 75 to 89). CT angiography was similar to conventional angiography in its ability to identify patients who subsequently underwent revascularization: the AUC was 0.84 (95% CI, 0.79 to 0.88) for multidetector CT angiography and 0.82 (95% CI, 0.77 to 0.86) for conventional angiography. A per-vessel analysis of 866 vessels yielded an AUC of 0.91 (95% CI, 0.88 to 0.93). Disease severity ascertained by CT and conventional angiography was well correlated (r=0.81; 95% CI, 0.76 to 0.84). Two patients had important reactions to contrast medium after CT angiography. Conclusions: Multidetector CT angiography accurately identifies the presence and severity of obstructive coronary artery disease and subsequent revascularization in symptomatic patients. The negative and positive predictive values indicate that multidetector CT angiography cannot replace conventional coronary angiography at present. (ClinicalTrials.gov number, NCT00738218.).

Coronary Artery Stenoses: Accuracy of 64-Detector Row CT Angiography in Segments with Mild, Moderate, or Severe Calcification-A Subanalysis of the CORE-64 Trial

Purpose: To evaluate the influence of cross-sectional arc calcification on the diagnostic accuracy of computed tomography (CT) angiography compared with conventional coronary angiography for the detection of obstructive coronary artery disease (CAD). Materials and Methods: Institutional Review Board approval and written informed consent were obtained from all centers and participants for this HIPAA-compliant study. Overall, 4511 segments from 371 symptomatic patients (279 men, 92 women; median age, 61 years [interquartile range, 53-67 years]) with clinical suspicion of CAD from the CORE-64 multi-center study were included in the analysis. Two independent blinded observers evaluated the percentage of diameter stenosis and the circumferential extent of calcium (arc calcium). The accuracy of quantitative multidetector CT angiography to depict substantial (>50%) stenoses was assessed by using quantitative coronary angiography (QCA). Cross-sectional arc calcium was rated on a segment level as follows: noncalcified or mild (<90 degrees), moderate (90 degrees-180 degrees), or severe (>180 degrees) calcification. Univariable and multivariable logistic regression, receiver operation characteristic curve, and clustering methods were used for statistical analyses. Results: A total of 1099 segments had mild calcification, 503 had moderate calcification, 338 had severe calcification, and 2571 segments were noncalcified. Calcified segments were highly associated (P < .001) with disagreement between CTA and QCA in multivariable analysis after controlling for sex, age, heart rate, and image quality. The prevalence of CAD was 5.4% in noncalcified segments, 15.0% in mildly calcified segments, 27.0% in moderately calcified segments, and 43.0% in severely calcified segments. A significant difference was found in area under the receiver operating characteristic curves (noncalcified: 0.86, mildly calcified: 0.85, moderately calcified: 0.82, severely calcified: 0.81; P < .05). Conclusion: In a symptomatic patient population, segment-based coronary artery calcification significantly decreased agreement between multidetector CT angiography and QCA to detect a coronary stenosis of at least 50%.

Seven-year trend analysis of nosocomial candidemia and antifungal (fluconazole and caspofungin) use in Intensive Care Units at a Brazilian University Hospital

Candidemia is associated with high morbidity and mortality resulting in significant increases in the length of patients` hospitalization and in healthcare costs. Critically ill patients are at particular risk for candidemia because of their debilitated condition and frequent need for invasive procedures. The aim of this study was to characterize the incidence and epidemiology of candidemia over a seven-year period in intensive care units (ICUs) and the use of fluconazole and caspofungin in a large university-affiliated hospital. All cases of candidemia were identified by surveillance, using the Centers for Diseases Control and Prevention criteria. Demographic variables, use of antifungal (fluconazole and caspofungin) and patient outcomes were evaluated. The 2 test for linear trend was employed to evaluate the distribution of Candida spp. and the use of fluconazole and caspofungin by defined daily dose (DDD) per 1,000 patients-days during the study period. One hundred and eight episodes of candidemia were identified. The overall incidence of candidemia (P=0.20) and incidence of non-Candida albicans Candida infections (P=0.32) remained stable over the study period and ranged from 0.3-0.9 episodes per 1,000 catheter-days and 0.39-0.83 episodes per 1,000 patients-days. However, the use of fluconazole and caspofungin increased significantly (P0.001). While there were no reports of the use of fluconazole for prophylaxis in 1999, its use for this purpose increased from 3% in 2000 to 7.0% (P=0.07) in 2006. C. albicans was the most frequent specie isolated and burns and cancer were the most frequent underlying conditions. The overall mortality was 76%. There was no difference between C. albicans and non-C. albicans Candida infections when the crude and 14-day mortality rates were compared. Our data demonstrated that C. albicans is still the most frequent species causing candidemia in our intensive care units. Our rates of candidemia are lower than those reported from the region and similar to American and European hospitals. Although the incidence of blood stream infections (BSI) and candidemia remained stable, the use of fluconazole and caspofungin increased significantly over the years included in this study but had no impact on the incidence of infections caused by non-C. albicans Candida species.

A university extension course in leprosy: telemedicine in the Amazon for primary healthcare

There is a high prevalence of leprosy in the Amazon region of Brazil. We have developed a distance education course in leprosy for training staff of the Family Health Teams (FHTs). The course was made available through a web portal. Tele-educational resources were mediated by professors and coordinators, and included the use of theoretical content available through the web, discussion lists, Internet chat, activity diaries, 3-D video animations (Virtual Human on Leprosy), classes in video streaming and case simulation. Sixty-five FHT staff members were enrolled. All of them completed the course and 47 participants received a certificate at the end of the course. At the end of the course, 48 course-evaluation questionnaires were answered. A total of 47 participants (98%) considered the course as excellent. The results demonstrate the feasibility of an interactive, tele-education model as an educational resource for staff in isolated regions. Improvements in diagnostic skills should increase diagnostic suspicion of leprosy and may contribute to early detection.

Low dose of fine particulate matter (PM2.5) can induce acute oxidative stress, inflammation and pulmonary impairment in healthy mice

Air pollution is associated with morbidity and mortality induced by respiratory diseases. However, the mechanisms therein involved are not yet fully clarified. Thus, we tested the hypothesis that a single acute exposure to low doses of fine particulate matter (PM2.5) may induce functional and histological lung changes and unchain inflammatory and oxidative stress processes. PM2.5 was collected from the urban area of Sao Paulo city during 24 h and underwent analysis for elements and polycyclic aromatic hydrocarbon contents. Forty-six male BALB/c mice received intranasal instillation of 30 mu L of saline (CTRL) or PM2.5 at 5 or 15 mu g in 30 mu L of saline (P5 and P15, respectively). Twenty-four hours later, lung mechanics were determined. Lungs were then prepared for histological and biochemical analysis. P15 group showed significantly increased lung impedance and alveolar collapse, as well as lung tissue inflammation, oxidative stress and damage. P5 presented values between CTRL and P15: higher mechanical impedance and inflammation than CTRL, but lower inflammation and oxidative stress than P15. In conclusion, acute exposure to low doses of fine PM induced lung inflammation, oxidative stress and worsened lung impedance and histology in a dose-dependent pattern in mice.

Demographic profile of blood donors at three major Brazilian blood centers: results from the International REDS-II study, 2007 to 2008

BACKGROUND: The profile of blood donors changed dramatically in Brazil over the past 20 years, from remunerated to nonremunerated and then from replacement to community donors. Donor demographic data from three major blood centers establish current donation profiles in Brazil, serving as baseline for future analyses and tracking longitudinal changes in donor characteristics. STUDY DESIGN AND METHODS: Data were extracted from the blood center, compiled in a data warehouse, and analyzed. Population data were obtained from the Brazilian census. RESULTS: During 2007 to 2008, there were 615,379 blood donations from 410,423 donors. A total of 426,142 (69.2%) were from repeat (Rpt) donors and 189,237 (30.8%) were from first-time (FT) donors. Twenty percent of FT donors returned to donate in the period. FT donors were more likely to be younger, and Rpt donors were more likely to be community donors. All were predominantly male. Replacement donors still represent 50% of FT and 30% of Rpt donors. The mean percentage of the potentially general population who were donors was approximately 1.2% for the three centers (0.7, 1.5, and 3.1%). Adjusting for the catchment`s area, the first two were 2.1 and 1.6%. CONCLUSIONS: Donors in the three Brazilian centers tended to be younger with a higher proportion of males than in the general population. Donation rates were lower than desirable. There were substantial differences in sex, age, and community/replacement status by center. Studies on the safety, donation frequencies, and motivations of donors are in progress to orient efforts to enhance the availability of blood.

Clinical Validity of the Protocol for Multi-Professional Centers for the Determination of Signs and Symptoms of Temporomandibular Disorders. Part II

The aims of this study were to analyze the criterion and construct validity of Part II of the protocol for multi-professional centers for the determination of signs and symptoms of temporomandibular disorders (ProTMDMulti) as a measure of TMD severity. The study was conducted on eight asymptomatic subjects (CG) and 30 subjects with articular TMD (TMDG), according to the Research Diagnostic Criteria for TMD (RDC/TMD). The ProTMDMulti-Part II was validated using the Helkimo Clinical Dysfunction Index (Di). The construct validity was tested using the analysis of the ability of ProTMDMulti-part II to differentiate the CG from the TMDG and to measure the changes that occurred in the TMDG between the period before and after TMD treatment. Correlations between the Di and the ProTMDMulti-Part II scores were calculated using the Spearman test. Inter- and intragroup comparisons were made (p<0.05). There was a statistically significant correlation between the Helkimo Clinical Dysfunction Index (Di) and the severity scores of the ProTMDMulti-Part II. There was a significant difference between TMDG and CG regarding the severity of signs and symptoms. The present study provides statistical evidence of the clinical validity of the ProTMDmulti-Part II as a measure of the severity of TMD symptoms.

Characteristics of a large population of patients with refractory epilepsy attending tertiary referral centers in Italy

P>The characteristics of 1,124 consecutive adults and children with refractory epilepsy attending 11 tertiary referral centers in Italy were investigated at enrollment into a prospective observational study. Among 933 adults (age 16-86 years), the most common syndromes were symptomatic (43.7%) and cryptogenic (39.0%) focal epilepsies, followed by idiopathic (8.1%) and cryptogenic/symptomatic generalized (6.2%) epilepsies. The most common syndrome among 191 children was symptomatic focal epilepsy (35.1%), followed by cryptogenic focal (18.8%), cryptogenic/symptomatic generalized (18.3%), undetermined whether focal or generalized (16.8%), and idiopathic generalized (7.3%). Primarily and secondarily generalized tonic-clonic seizures were reported in 27.8% of adults and 16.8% of children. The most commonly reported etiologies were mesial temporal sclerosis (8.0%) and disorders of cortical development (6.2%) in adults, and disorders of cortical development (14.7%) and nonprogressive encephalopathies (6.8%) in children. More than three-fourths of subjects in both age groups were on antiepileptic drug (AED) polytherapy.

Audit and comprehensive health assessment programme in the primary healthcare of adults with intellectual disability: a pilot study

International research has demonstrated significant shortcomings in the health of adults with intellectual disability (ID). Because general practitioners (GPs) are the main providers of primary healthcare for this population, strategies to improve general practice care are an important aspect of rectifying these shortcomings. The present pilot study aimed to determine the effect of various interventions on health maintenance activities and to assess their acceptability to GPs, with a view to informing larger scale studies. The GPs were recruited through an earlier questionnaire-based postal survey. The GPs identified all their adult patients with ID, then obtained consent for participation from three patients randomly selected by the investigators. The GPs completed two self-evaluation forms and case note audits 12 months apart, read a synopsis of the relevant literature provided by the researchers, and completed a comprehensive health assessment (CHA) of their three patients. Forty-five GPs agreed to participate in the CHA programme (CHAP), and 15 completed the project. Thirty-eight patients completed the project. The number of patient-GP dyads who completed the project was too small to demonstrate statistically significant changes in health issues over time. The GPs found that the synopsis of the literature was the best intervention for increasing knowledge and was also the most practical to use in general practice. The CHAP was the intervention that prompted the most action from the GP which would not have been undertaken otherwise. The CHAP appeared to provide a superior review process compared to the other interventions used in the present study. The numbers of health maintenance activities found to be overdue and the number of health issues detected as a result of the process were considerable. The CHAP served as a communication tool and an educative instrument, providing a basis for future studies and strategies to improve the general practice care of adults with ID.