RESUMO
Stark broadening of hydrogen lines in the presence of a magnetic field is revisited, with emphasis on the role of the ion component under typical conditions of magnetized fusion devices. An impact theory for ions valid at low density (N_{e} < or approximately 10;{14} cm;{-3}) and taking into account the Zeeman degeneracy removal of the atomic states is developed. It is shown that the Stark widths of the Lorentz triplet components strongly depend on the magnetic field. The model is validated by a computer simulation method. For the lateral sigma components of Lyalpha , we show that the impact approximation still holds for densities as high as N_{e} approximately 10;{15} cm;{-3}. In contrast, for the central pi component as well as for the other lines from low principal quantum number, significant discrepancies between the proposed theory and the simulation results appear at high density. Application to Dalpha in tokamak divertor plasma conditions shows that, in this case, the quasistatic approximation becomes more relevant.
RESUMO
Two-dimensional echocardiography has proven very useful in assessing valvular heart disease, but the technique is limited in certain groups of patients and is unable to quantify a transvalvular pressure gradient. Advances in the Doppler ultrasound techniques have made it possible to noninvasively measure velocity of flow across a stenotic heart valve and to calculate the pressure gradient. A commercially available, continuous and pulse wave Doppler instrument was utilized to assess the transvalvular pressure gradient in patients with mitral and aortic stenosis and the transmitral pressure half-time to calculate mitra valve area. Thirty-five consecutive adult patients with suspected aortic stenosis and 30 adult patients with suspected mitral stenosis underwent Doppler ultrasound examination within 24 hours of cardiac catheterization. An adequate Doppler examination was obtained in 81% of the patients with aortic stenosis, with a correlation between the Doppler-derived transaortic gradient and the catheterization-derived gradient of 0.94. The Doppler-measured gradient accurately separated those patients with significant aortic stenosis (gradients of greater than 50 mm Hg) from those patients with noncritical aortic stenosis. Similarly, an adequate Doppler examination was obtained in 90% of the adult patients with mitral stenosis. There was also close correlation between the mitral valve area and mean pressure gradient measured by the Doppler technique and that obtained at the time of cardiac catheterization (r = 0.87 and 0.85, respectively). The Doppler technique proved to be useful in those patients who had also undergone prior mitral commissurotomy. This study confirms that the combined continuous pulse wave Doppler technique will serve as a valuable addition to the diagnostic capabilities offered by echocardiography.
Assuntos
Estenose da Valva Aórtica/diagnóstico , Estenose da Valva Mitral/diagnóstico , Ultrassonografia , Adulto , Idoso , Cateterismo Cardíaco , Ecocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Pressão , Ultrassom/instrumentaçãoRESUMO
Three patients with liver metastases from colon carcinoma were studied with 2-deoxy-2-[F-18]fluoro-d-glucose (F-18-FDG) using positron emission tomography. The radioactivity in the metastatic tumor increased continuously following the injection of F-18-FDG, whereas it decreased in normal liver tissue. This resulted in the tumor to normal-liver ratio of 3.3-4.7 at 50 min after injection. The liver tumor was visualized as an increased accumulation of radioactivity in all patients, with the central area of the tumor showing less activity. These preliminary results suggest that F-18-FDG may be useful as a positive imaging agent for the detection and characterization of liver tumors.
Assuntos
Adenocarcinoma/diagnóstico por imagem , Neoplasias do Colo/diagnóstico por imagem , Desoxiaçúcares , Desoxiglucose , Neoplasias Hepáticas/diagnóstico por imagem , Tomografia Computadorizada de Emissão , Adenocarcinoma/secundário , Idoso , Desoxiglucose/análogos & derivados , Feminino , Flúor , Fluordesoxiglucose F18 , Humanos , Neoplasias Hepáticas/secundário , Masculino , Pessoa de Meia-Idade , RadioisótoposRESUMO
AIM: The aim of the study was to establish which anthropometric characteristics, physical abilities and psycho-physiological properties determine the success of adolescent female volleyballers at competitions. METHODS: For this purpose we studied 32 female volleyballers aged 13-16 years. The anthropometric examination included 43 measurements, 7 tests of physical fitness, and 4 series of computerised psycho-physiological tests (n=21). The performance of game elements was measured empirically during championship games using the original computer program "Game". RESULTS: The proficiency of performing volleyball elements - serve, reception, feint, block and spike - was calculated by regression models from the 14 anthropometric measurements, 4 physical fitness and 7 psychophysiological test results, which showed significant correlation with proficiency in the game. The predictive power of the models was at least 32% and in average 56%. The anthropometric factor was significant in the performance of all the elements of the game, being most essential (71-83%) for attack, block and feint. Good results in physical ability tests granted success in serve, attack and reception. CONCLUSION: It was possible to predict the efficiency of reception (44%) by endurance, flexibility and speed measuring tests. Medicine ball throwing test was essential for attack (22%). Psycho-physiological tests were significant for the performance of block (98%), attack (80%), feint (60%) and reception (39%).
Assuntos
Antropometria , Metabolismo Energético/fisiologia , Aptidão Física/fisiologia , Desempenho Psicomotor/fisiologia , Esportes/fisiologia , Adolescente , Feminino , Humanos , Análise de Regressão , Estatística como AssuntoRESUMO
Anthropometric investigation of 670 female students (aged 18-22), 1114 schoolgirls (aged 15-18) and 253 schoolboys (aged 17-18) has demonstrated that the body structure in these samples formed a distinctive system of significantly intercorrelated variables with the body mass and length being the major characteristics. By means of a mass-length (height-weight) classification it is possible to systematize all the single parameters, indices and body composition characteristics. Body mass and length are also assumed as a basis for the formation of extreme pure somatotypes--pycnic and leptosomatic females.
Assuntos
Antropometria , Adolescente , Adulto , Estônia , Feminino , Humanos , MasculinoRESUMO
The divergence that occurs at large impact parameters in Stark collision operators is examined for low-density hydrogen plasmas. In a previous work [J. Rosato, H. Capes, and R. Stamm, Phys. Rev. E 86, 046407 (2012)], we showed that the correlations between a radiating atom and the charged particles surrounding it affect the mean evolution of the atom, resulting in a mitigation of the Stark broadening near the line center. In this work, we examine the physical mechanism underlying this mitigation with an approach inspired from the standard semiclassical impact model. Our approach accounts for the atom-perturber correlations in a simple fashion, through a cutoff at large impact parameters, and embraces the impact model in the weakly coupled plasma limit. Comparisons with numerical simulations are performed and indicate a good agreement.
RESUMO
An investigation of spectral line broadening in plasmas is carried out within a kinetic-theory approach, based on the Bogoliubov-Born-Green-Kirkwood-Yvon (BBGKY) hierarchy. The model employs a resummation procedure to account for correlated emitter-perturber collisions. Applications to hydrogen lines indicate that such collisions strongly affect the width and the shape in the core region. This argument is supported by comparisons to numerical simulations. It is also shown that the usual collision operator models, based on a binary description of emitter-perturber collisions, can be extremely inaccurate. The present model, in a better agreement with numerical simulations, is suggested as an extension suitable for the design of fast and accurate numerical routines for plasma diagnostics.
Assuntos
Ecocardiografia , Infarto do Miocárdio/diagnóstico , Adulto , Idoso , Eletrocardiografia , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Contração Miocárdica , Infarto do Miocárdio/fisiopatologia , Risco , Choque Cardiogênico/prevenção & controle , Fatores de TempoAssuntos
Comportamento Animal , Caramujos/fisiologia , Simbiose , Animais , Eucariotos , Especificidade da EspécieRESUMO
On the first inertial-confinement-fusion ignition facility, the target capsule will be DT filled through a long, narrow tube inserted into the shell. microg-scale shell perturbations Delta m' arising from multiple, 10-50 microm-diameter, hollow SiO2 tubes on x-ray-driven, ignition-scale, 1-mg capsules have been measured on a subignition device. Simulations compare well with observation, whence it is corroborated that Delta m' arises from early x-ray shadowing by the tube rather than tube mass coupling to the shell, and inferred that 10-20 microm tubes will negligibly affect fusion yield on a full-ignition facility.
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MEGA is the chemical workplace exposure database of the Institute for Occupational Safety (BIA) of the German Berufsgenossenschaften (BG) (statutory accident institutions for insurance and prevention). On the legal basis of the social insurance law the inspectorates of the BGs conduct workplace measurements of chemical and biological agents. The BGs have cooperated with BIA within the Berufsgenossenschaftliches Messsystem Gefahrstoffe--BGMG since 1972: measurements are done by the BGs, analyses and data processing are the tasks of BIA. In 1999 31,000 measurements with 68,000 analyses were taken in 4,000 enterprises. All data are stored in the MEGA-database with up to 150 pieces of information (describing type of workplace, working conditions, measured substances, sampling strategy, sampling duration, sampling and analytical method etc.), for each result. MEGA contains today about 1,000,000 measurements of more than 400 substances starting in 1972. MEGA is used by BIA and the BGs for the following purposes: prevention (e.g., identification of hazards, efficiency of exposure reducing measures, determination of technical criteria for exposure limit values), epidemiological questions, and investigations of occupational diseases. In the framework of the measuring and inspection activities and tasks of the inspectorates of the BGs the locations for measurements are not randomly selected, but are based on criteria such as supposed critical exposure situations or testing the efficiency of exposure reducing measures. Nevertheless, a statistical appraisal of the data is possible for different purposes considering the specific determinants of the results, as, for example, classification of enterprises (sectors), workplaces (activities, tasks), used materials, and products. The MEGA-database will be further developed into a multifactorial exposure database with additional data on biological exposure to bacteria and funghi, but also noise and other data.
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Bases de Dados Factuais , Substâncias Perigosas , Serviços de Informação , Exposição Ocupacional/estatística & dados numéricos , Alemanha , Guias como Assunto , Humanos , Publicações , Medição de Risco/estatística & dados numéricosRESUMO
Despite intensive research in recent decades, the search for the aetiopathogenesis of psychiatric diseases is just as relevant as ever. In recent years, ideas of the aetiopathogenesis of psychotic diseases based on the concept of "vulnerability" in its diverse variations and developments have been gained increasingly ground. The publications of Zubin and associates above all have contributed to a "vulnerability model". According to this descriptive model, schizophrenic disturbances develop as a result of stimuli/irritants or stress factors under modulation of the social and physical environment as well as dependent on the premorbid personality. The increased vulnerability which gives rise to this is perceived as a threshold descensus of the individual towards stimuli/irritants (with a deficit counter--irritants impulses). Apart from that, multi-causality of vulnerability is assumed as the starting point, whereby there is the possibility of several therapy approaches. Moreover, contrary to the prevailing pessimistic view that schizophrenia is a process-type progressive disease, an episodic nature of schizophrenic psychoses is postulated with a prognosis that is indeed positive in the long term. In recent years, although often not explicitly stated, Zubin's concept of vulnerability was also indubitably subjected to various further developments (the vulnerability stress model by Nuechterlein and associates as also the integrative psycho-biological schizophrenia model by Ciompi may serve as examples). Worth mentioning are also various new concepts from system sciences (such as those from cybernetics, synergetics, the chaos theory, the communication theory, structure determinism etc.), which endeavour to clarify the problem of psychosis. The evaluation of central neurophysiological function deviations with schizophrenics and their relations has so far been oriented above all towards the vulnerability model of Zubin and Nuechterlein, which differentiates temporarily relatively stable trait markers with generally unaltered expressivity at the pre-, intra-, and post-psychotic stages as well as episode markers and intermediate markers. However, specific factors contributing to the pathogenesis of schizophrenic disturbances have not as yet been found, in addition, there is still a multitude of methodological problems and distinctive features to fulfill the expectation of a comprehensive concept with which the whole complexity of the occurrence, the progress, and the outcome of psychoses can be explained. Reintroduction of the concept of vulnerability experienced, as Schmidt-Degenhardt put it, "a renaissance in use that appeared almost inflationary and a completely dubious popularisation ... without reference to its historical implications...". Consequently, a critical view of the use of this term would appear to be necessary.
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Transtornos Mentais/psicologia , Psicologia do Esquizofrênico , Humanos , Transtornos Mentais/etiologia , Modelos PsicológicosRESUMO
The article describes an anthropometric cross-sectional study of 374 healthy schoolgirls aged 12-15 years from secondary schools of Tartu (Estonia). 29 body measurements and 9 skinfolds were measured. Mean skinfolds and 6 indices and ratios (including body mass index) were calculated. In each age group the data were systematized into 5 height-weight SD-classes according to the correspondence between body height and weight. The medium class lies between -0.5 SD and +0.5 SD of the respective age group mean (M +/- 0.5 SD); the other classes contain the respective outer values. All the subjects were assigned into one of the following five categories: three height/weight-concordant categories: I = small (small height-small weight), II = medium (medium height-medium weight), III = large (big height-big weight) and two height/weight-disconcordant categories: IV = so-called pyknomorphous, V = so-called leptomorphous. Categories IV and V thus contained three height/weight subclasses each. The body build categories differ significantly from each other within both groups (I-III and IV-V) in all age groups in all measured variables, except sternum length, abdomen length, trunk length, biacromial breadth, biiliocrystal breadth, femur breadth, ankle breadth, humerus breadth, wrist breadth, and head circumference for which no significant differences between pyknomorphous and leptomorphous categories were found. A multidimensional statistical model of body build might be used in girls going through puberty to systematize and compare morphological variables with other assessed characteristics in different applied studies, for example physiological, sociological, psychological, or nutritional.
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Antropometria/métodos , Adolescente , Criança , Estônia , Feminino , Humanos , Distribuição Aleatória , Valores de Referência , Dobras Cutâneas , SomatotiposRESUMO
Quantitative determination of stained proteins following polyacrylamide gel electrophoresis (PAGE) is of increasing interest especially since computer-aided densitometers have become available as well as recipes for sensitive and background-free staining with Coomassie Brilliant Blue dyes. However, avoidance of separation artifacts is not the only essential prerequisite for quantitative evaluation. The local particle density of a protein in a given gel is of critical importance since it determines its stainability. Depending on local protein concentration, the dye binding to the same amount of a given protein differs considerably. Since the stainability of proteins using colloidal staining procedures, as with Coomassie Brilliant Blue dyes, is time-dependent and, in addition, also dependent on the pore size of a given polyacrylamide gel used for PAGE, calibration curves for quantitative determinations have to be prepared in polyacrylamide gels of the same composition as used for PAGE. Staining conditions also have to be identical for calibration gels and gels under analysis. If, however, a set of calibration curves is prepared for different staining times, it is possible to calculate a generalized calibration curve, allowing for quantitative evaluation with flexible staining time. Furthermore, and in consequence of the implications due to particle density, quantitative determination via densitometry is only possible by determining the protein amount of each single measuring point (pixel) via its absorbance on the basis of a calibration curve. Since the particle density is inherent in a calibration curve, the final summation of the protein amount per pixel will give values close to reality.
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Proteínas/análise , Corantes de Rosanilina , Coloração e Rotulagem , Calibragem , Coloides , Densitometria , Difusão , Eletroforese em Gel de Poliacrilamida , Luz , Modelos Químicos , Reprodutibilidade dos Testes , Espalhamento de RadiaçãoRESUMO
In 18 consecutive patients with a new murmur following acute myocardial infarction (AMI), examination by two-dimensional echocardiography (2DE) correctly excluded ventricular septal defects (VSD) in eight patients and enabled direct visualization of the VSD in 10 patients. In three patients, 2DE was the first technique to establish the diagnosis. In all patients with VSD, 2DE diagnosis was confirmed by catheterization, surgery, and/or postmortem examination. In six patients with VSD, 2DE contrast studies were performed and were positive. 2DE enabled localization of the VSD in all patients (five inferior, five anterior). To evaluate left ventricular (LV) function, a 2DE wall motion index (WMI) was calculated using an 11 segment model of the LV. While there was no difference (p greater than 0.2) in AMI-VSD survivors versus nonsurvivors in age, kinase, and AVO2 difference, there was no overlap in WMI (p = 0.004) of survivors (0.80 +/- 0.36) versus nonsurvivors (1.66 +/- 0.19). Thus 2DE allows accurate detection and localization of postmyocardial infarction VSD and enables determination of prognosis of these patients.