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1.
Geophys Res Lett ; 47(15): e2020GL088803, 2020 Aug 16.
Artigo em Inglês | MEDLINE | ID: mdl-32999519

RESUMO

We investigate the forces and atmosphere-ionosphere coupling that create atmospheric dynamo currents using two rockets launched nearly simultaneously on 4 July 2013 from Wallops Island (USA), during daytime Sq conditions with ΔH of -30 nT. One rocket released a vapor trail observed from an airplane which showed peak velocities of >160 m/s near 108 km and turbulence coincident with strong unstable shear. Electric and magnetic fields and plasma density were measured on a second rocket. The current density peaked near 110 km exhibiting a spiral pattern with altitude that mirrored that of the winds, suggesting the dynamo is driven by tidal forcing. Such stratified currents are obscured in integrated ground measurements. Large electric fields produced a current opposite to that driven by the wind, believed created to minimize the current divergence. Using the observations, we solve the dynamo equation versus altitude, providing a new perspective on the complex nature of the atmospheric dynamo.

2.
BMJ Mil Health ; 2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38844376

RESUMO

Dietary supplements, products that contain one or more dietary ingredients, or their components, typically in a concentrated form, are often consumed for purported health and performance benefits. The frequency, forms and motivations for dietary supplement use may differ between civilian and military populations. The objective of this manuscript is to review patterns and trends in dietary supplement use in military personnel from the USA, France, the UK and Slovenia. Main findings indicate that dietary supplement use may be higher in military personnel as compared with civilian populations. Factors motivating dietary supplement use in military personnel include physical and cognitive performance, recovery, and the maintenance of body weight and composition, whereas civilian populations tend to be motivated by health and wellness. Commonly used dietary supplements in military populations, such as proteins and amino acids, may be associated with performance, body weight management and body composition. The relationship between dietary supplement use and the frequency and severity of adverse events, along with the potential benefits of dietary supplements, has not been carefully assessed in military populations and should be the focus of future studies.

3.
J Geophys Res Space Phys ; 127(5): e2021JA030191, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35860290

RESUMO

E × B plasma drifts and plasma number density were measured on two NASA rockets launched simultaneously at sunset from Kwajalein Atoll with apogees of 182 and 331 km, with similar, coincident measurements gathered on the Communications/Navigation Outage Forecasting System (C/NOFS) satellite at 390 km. The combined measurements portray a highly dynamic ionosphere in a narrow range of local time and altitude, providing evidence of vortex-like motions. Although the vertical plasma drift was upwards, its magnitude was not constant, increasing between ∼150 and 250 km altitude where the plasma density was reduced. The zonal plasma drifts displayed a shear with altitude, changing from eastward to westward flow below 270 km, coincident with the larger upward drifts and consistent with the maintenance of the vortex flow. The plasma density on the western flank was highly structured compared to the eastern flank, despite the fact that the western region corresponded to slightly earlier local times. These observations illustrate that the low latitude ionosphere at sunset must be considered as an ensemble of interconnected flows encompassing an evolving "theater," as opposed to a background that simply unfolds linearly with respect to local time. The observations also underscore how satellites at high altitudes do not capture the highly dynamic ionosphere and thermosphere at the lower altitudes which are critical for understanding the electrodynamics system. Such motions set the stage for large scale plasma instabilities to form later in the evening, as observed by radars at Kwajalein and subsequent passes of the C/NOFS satellite.

4.
Ecol Evol ; 12(6): e8932, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35784056

RESUMO

Plant phenology is not only manifested in the seasonal timing of vegetative and reproductive processes but also has ontogenetic aspects. The adaptive basis of seasonal phenology has been considered mainly in terms of climatic drivers. However, some biotic factors as likely evolutionary influences on plants' phenology appear to have been under-researched. Several specific cases of putative biotic factors driving plant phenology are outlined, involving both herbivores and pathogens. These illustrate the diversity of likely interactions rather than any systematic coverage or review. Emphasis is on woody perennials, in which phenology is often most multifaceted and complicated by the ontogenetic aspect. The complete seasonal leaf fall that characterizes deciduous plants may be a very important defense against some pathogens. Whether biotic influences drive acquisition or long-term persistence of deciduousness is considered. In one case, of leaf rusts in poplars, countervailing influences of the rusts and climate suggest persistence. Often, however, biotic and environmental influences likely reinforce each other. The timing and duration of shoot flushing may in at least some cases contribute to defenses against herbivores, largely through brief periods of "predator satiation" when plant tissues have highest food value. Wide re-examination of plant phenology, accommodating the roles of biotic factors and their interplays with environments as additional adaptive drivers, is advocated toward developing and applying hypotheses that are observationally or experimentally testable.

5.
Ultrasound Med Biol ; 34(8): 1292-306, 2008 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-18343021

RESUMO

The purpose of this study was to characterize the ultrasonic properties of agar-based tissue-mimicking materials (TMMs) at ultrasound frequencies centered around 20 MHz. The TMM acoustic properties measured are the amplitude attenuation coefficient alpha (dB cm(-1)MHz(-1)), the speed of sound (ms(-1)) and the backscattered power spectral density (distribution of power per unit frequency normalized to the total received power) characteristics of spectral slope (dB MHz(-1)), y-axis intercept (dB) and reflected power (dB). The acoustic properties are measured over a temperature range of 22 to 37 degrees C. An intercomparison of results between two independent ultrasound measurement laboratories is also presented. A longitudinal study of the acoustic properties over a period of two years is also detailed, and the effect of water immersion on the acoustic properties of TMM is measured. In addition, the physical parameters of mass density rho (kg m(-3)) and specific heat capacity C (J kg(-1) K(-1)) are included. The measurement techniques used were based on the substitution technique using both broadband and narrowband pulses centered on 20 MHz. Both the attenuation coefficient and speed of sound (both group and phase) showed good agreement with the expected values of 0.5 dB cm(-1) MHz(-1) and 1540 ms(-1), respectively, with average values over the three-year period of 0.49 dBcm(-1)MHz1 (SD +/- 0.05) and 1540.9 ms(-1) (SD +/- 8.7). These results also showed agreement between the two independent measurement laboratories. Speed of sound and attenuation coefficient were shown to change with temperature with rates of + 2.1 m s(-1) degrees C(-1) and -0.005 dB cm(-1) MHz(-1) degrees C(-1), respectively. Attenuation changed linearly with frequency at the high frequency range of 17 to 23 MHz, and speed of sound was found to be independent of frequency in this range. The spectral slope of relative backscattered power for the material increased with frequency at typically 1.5 dB MHz(-1). This compared favorably with theoretical spectral slope values, calculated for a variety of scatterer sizes, albeit at a lower frequency range. It is also noticed that, on extrapolation back to lower frequencies, the backscatter is comparable with that measured at 7 MHz. Overall, this non-commercial agar-based TMM is shown to perform as expected at the higher frequency range of 17 to 23 MHz and is seen to retain its acoustic properties of attenuation and speed of sound over a three-year period.


Assuntos
Imagens de Fantasmas/normas , Ultrassonografia/instrumentação , Ágar , Calibragem , Humanos , Valores de Referência , Espalhamento de Radiação , Temperatura , Fatores de Tempo
6.
Chem Commun (Camb) ; 54(16): 1980-1983, 2018 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-29404555

RESUMO

New Raman spectra of Na2S dissolved in hyper-concentrated NaOH(aq) and CsOH(aq) cast serious doubt on the widely-assumed existence of S2-(aq). To avoid conceptual and practical problems with sulfide equilibria in numerous applications, S2-(aq) should be expunged from the chemical literature. Thermodynamic databases involving sulfide minerals also need careful revision.

7.
Int J Impot Res ; 29(5): 202-206, 2017 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-28701798

RESUMO

The goal of this study was to determine potential positive effects of cognitive behavioral therapy (CBT) on Pakistani men with ED who were undergoing treatment with a PDE-5 inhibitor. We used a pre-post research design comparing men with and without adjunctive CBT. Men in the two groups were compared to determine whether CBT improved sexual function, as measured by the International Index of Erectile Function (IIEF). A total of 60 individuals diagnosed with ED completed the study. Participants were systematically assigned to one of two groups, the CBT group or the control group. The sample was drawn from outpatients referred through several hospitals in Islamabad. All men showed improvement in sexual functioning over the course of the study, though post treatment, men in the CBT group showed greater improvement on IIEF subscales of erectile functioning, orgasmic function, intercourse satisfaction and overall satisfaction than those in the control group. CBT can be considered an effective and supportive means for achieving better sexual outcomes for Pakistani men taking PDE-5 inhibitors for erectile problems.


Assuntos
Terapia Cognitivo-Comportamental , Coito/psicologia , Disfunção Erétil/psicologia , Disfunção Erétil/terapia , Inibidores da Fosfodiesterase 5/uso terapêutico , Adulto , Humanos , Masculino , Orgasmo , Paquistão , Satisfação do Paciente , Ereção Peniana , Índice de Gravidade de Doença , Adulto Jovem
8.
Arch Intern Med ; 149(4): 885-8, 1989 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2705837

RESUMO

Cofactors for the clinical expression of infection due to the human immunodeficiency virus (HIV) are not well understood. We asked if there was a familial tendency to the development of complications of HIV infection. We examined 35 hemophilic sibships in which at least two brothers with classic hemophilia (factor VIII deficiency) were infected with HIV. Twenty-four (34%) of the 70 patients had serious sequelae of infection, and 46 (66%) were asymptomatic or had only lymph node enlargement. Using Fisher's exact test, we found the concordance among siblings for serious sequelae of HIV infection was greater than would be expected by chance. When analysis was restricted to include only siblings known to be infected for more than two years, this concordance was still present. In the study population, birth order and mean yearly usage of factor VIII concentrate were unrelated to the outcome of HIV infection. The data indicate a familial tendency to serious complications of HIV infection. The factor(s) responsible for this familial tendency are currently under investigation.


Assuntos
Síndrome da Imunodeficiência Adquirida/complicações , Doenças Hematológicas/etiologia , Hemofilia A/terapia , Síndrome da Imunodeficiência Adquirida/transmissão , Doenças Hematológicas/genética , Hemofilia A/genética , Humanos , Masculino , Fatores de Risco
9.
Neurosci Biobehav Rev ; 19(2): 201-9, 1995.
Artigo em Inglês | MEDLINE | ID: mdl-7630576

RESUMO

The psychophysiological method has been applied to the study of human sexual response for well over three decades. The value of this method in providing an objective, integrated approach to the understanding of sexual response, and more specifically sexual dysfunction, is presented. Selected results from recent studies using this methodology illustrate the complex relationships that emerge among cognitive, affective, and physiological components of the sexual response. In addition, data from a systematic study of the use of psychophysiological procedures as an aid in differential diagnosis are given as evidence that this methodology offers a further strategy for assessing problems such as erectile dysfunction and premature ejaculation. Finally, recent findings utilizing sensory psychophysical procedures which relate subjective penile thresholds to sexual response and dysfunction are reviewed. Such procedures also study the interaction of physical/physiological systems with psychological events, and as such may be considered relevant to understanding the relationship between psychological aspects of sexual response.


Assuntos
Psicofísica , Psicofisiologia , Disfunções Sexuais Fisiológicas/diagnóstico , Disfunções Sexuais Fisiológicas/psicologia , Feminino , Humanos , Masculino , Disfunções Sexuais Fisiológicas/fisiopatologia
10.
Proc Biol Sci ; 264(1383): 919-25, 1997 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-9265191

RESUMO

Benson & Perrett's (1991 b) computer-based caricature procedure was used to alter the positions of anatomical landmarks in photographs of emotional facial expressions with respect to their locations in a reference norm face (e.g. a neutral expression). Exaggerating the differences between an expression and its norm produces caricatured images, whereas reducing the differences produces 'anti-caricatures'. Experiment 1 showed that caricatured (+50% different from neutral) expressions were recognized significantly faster than the veridical (0%, undistorted) expressions. This held for all six basic emotions from the Ekman & Friesen (1976) series, and the effect generalized across different posers. For experiment 2, caricatured (+50%) and anti-caricatured (-50%) images were prepared using two types of reference norm; a neutral-expression norm, which would be optimal if facial expression recognition involves monitoring changes in the positioning of underlying facial muscles, and a perceptually-based norm involving an average of the expressions of six basic emotions (excluding neutral) in the Ekman & Friesen (1976) series. The results showed that the caricatured images were identified significantly faster, and the anti-caricatured images significantly slower, than the veridical expressions. Furthermore, the neutral-expression and average-expression norm caricatures produced the same pattern of results.


Assuntos
Gráficos por Computador , Emoções , Expressão Facial , Percepção Visual , Adulto , Ira , Caricaturas como Assunto , Medo , Felicidade , Humanos , Sistemas de Informação , Pessoa de Meia-Idade , Tempo de Reação
11.
Am J Cardiol ; 75(12): 818-21, 1995 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-7717287

RESUMO

Assessment of ventricular contractility in the newborn infant using standard echocardiographic indexes can result in error due to the unique physiologic state that exists in the neonatal period. It has been suggested from animal and human studies that maturational alterations in contractility occur with birth and continue throughout infancy. To further investigate these developmental changes, 41 newborn infants aged 3 to 10 days and 37 children aged 3 to 18 years were evaluated with 2-dimensional and M-mode echocardiography. The rate-corrected velocity of circumferential fiber shortening (VCFc)-end-systolic wall stress (ESWS) relation was used as a load-independent estimate of contractility. Preload, afterload, and ventricular mass were also measured. Despite similar shortening fractions, the infant group had significantly higher mean VCFc and lower ESWS than the older age group (1.28 vs 1.08 circ/s and 30.2 vs 37.3 gm/m2, respectively). An inverse linear relation between VCFc and ESWS was found in both age groups. The y-intercept was higher in the infant group (p < 0.01), and the slope of the mean regression line was steeper than in the older children (p < 0.01). Ventricular mass in relation to body surface area increased with age. We conclude that (1) newborn infants have a higher basal contractile state that cannot be accounted for by lower afterload, (2) myocardial performance is more sensitive to afterload in the immature heart, and (3) shortening fraction may underestimate ventricular function in the newborn.


Assuntos
Débito Cardíaco/fisiologia , Ecocardiografia , Recém-Nascido/fisiologia , Contração Miocárdica/fisiologia , Volume Sistólico/fisiologia , Adolescente , Envelhecimento/fisiologia , Superfície Corporal , Criança , Pré-Escolar , Ecocardiografia Doppler , Feminino , Ventrículos do Coração/diagnóstico por imagem , Humanos , Modelos Lineares , Masculino , Sístole/fisiologia , Função Ventricular Esquerda/fisiologia , Pressão Ventricular/fisiologia
12.
Am J Cardiol ; 79(11): 1552-5, 1997 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-9185656

RESUMO

This study examines whether digital acoustic analysis of individual cardiac sound components for intensity, timing, and frequency could differentiate between innocent and pathologic murmurs. With use of this new technology, sensitive and specific criteria can be established for a fast and easy screening procedure to help differentiate between innocent and ventricular septal defect murmurs in children with suspected heart disease.


Assuntos
Sopros Cardíacos/etiologia , Comunicação Interventricular/diagnóstico , Fonocardiografia , Adolescente , Criança , Pré-Escolar , Diagnóstico Diferencial , Ecocardiografia Doppler , Feminino , Comunicação Interventricular/complicações , Comunicação Interventricular/diagnóstico por imagem , Humanos , Lactente , Recém-Nascido , Masculino , Fonocardiografia/métodos
13.
Am J Cardiol ; 79(3): 344-9, 1997 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-9036756

RESUMO

Most natural history data regarding pulmonary stenosis (PS) were obtained from cardiac catheterization studies over 15 to 20 years ago. Selection bias in these studies often excluded patients with mild disease and infants. Today, Doppler echocardiography allows accurate serial assessments of stenotic lesions in patients of all ages. This study evaluates the natural history of PS utilizing serial Doppler examinations in the pediatric population. A total of 147 patients with PS and serial echocardiographic data were identified. Age at initial echocardiogram ranged from 2 days to 15 years, with a mean follow-up of 2.4 years. Sixteen of 56 patients (29%) initially evaluated within 1 month had a > or = 20 mm Hg increase in their peak systolic pressure gradient. Only 7 of 89 patients (8%) initially evaluated over 1 month had a > or = 20 mm Hg increase. Eleven of 40 newborn infants (28%) with mild obstruction had progression to moderate or severe PS compared with 10 of 68 patients (15%) initially evaluated over 1 month. Moderate PS in the newborn was also more likely to progress compared with older children. Of the 16 newborns with > or = 20 mm Hg increases, 8 developed the increase in < or = 6 months. In contrast, no patient aged >2 years whose initial gradient was <50 mm Hg developed severe PS. Mild PS may not be static, particularly in young infants. Progression in this age group occurs more often and more rapidly than in older infants and children.


Assuntos
Ecocardiografia Doppler , Estenose da Valva Pulmonar/diagnóstico por imagem , Estenose da Valva Pulmonar/fisiopatologia , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Pré-Escolar , Fatores de Confusão Epidemiológicos , Feminino , Humanos , Lactente , Recém-Nascido , Masculino
14.
Cognition ; 63(3): 271-313, 1997 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-9265872

RESUMO

We report four experiments investigating the perception of photographic quality continua of interpolated ('morphed') facial expressions derived from prototypes of the 6 emotions in the Ekman and Friesen (1976) series (happiness, surprise, fear, sadness, disgust and anger). In Experiment 1, morphed images made from all possible pairwise combinations of expressions were presented in random order; subjects identified these as belonging to distinct expression categories corresponding to the prototypes at each end of the relevant continuum. This result was replicated in Experiment 2, which also included morphs made from a prototype with a neutral expression, and allowed 'neutral' as a response category. These findings are inconsistent with the view that facial expressions are recognised by locating them along two underlying dimensions, since such a view predicts that at least some transitions between categories should involve neutral regions or identification as a different emotion. Instead, they suggest that facial expressions of basic emotions are recognised by their fit to discrete categories. Experiment 3 used continua involving 6 emotions to demonstrate best discrimination of pairs of stimuli falling across category boundaries; this provides further evidence of categorical perception of facial expressions of emotion. However, in both Experiment 1 and Experiment 2, reaction time data showed that increasing distance from the prototype had a definite cost on ability to identify emotion in the resulting morphed face. Moreover, Experiment 4 showed that subjects had some insight into which emotions were blended to create specific morphed images. Hence, categorical perception effects were found even though subjects were sensitive to physical properties of these morphed facial expressions. We suggest that rapid classification of prototypes and better across boundary discriminability reflect the underlying organisation of human categorisation abilities.


Assuntos
Discriminação Psicológica/fisiologia , Emoções/classificação , Expressão Facial , Reconhecimento Visual de Modelos/fisiologia , Percepção Social , Adulto , Análise de Variância , Humanos , Análise por Pareamento , Pessoa de Meia-Idade
15.
Cognition ; 76(2): 105-46, 2000 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-10856740

RESUMO

The physical differences between facial expressions (e.g. fear) and a reference norm (e.g. a neutral expression) were altered to produce photographic-quality caricatures. In Experiment 1, participants rated caricatures of fear, happiness and sadness for their intensity of these three emotions; a second group of participants rated how 'face-like' the caricatures appeared. With increasing levels of exaggeration the caricatures were rated as more emotionally intense, but less 'face-like'. Experiment 2 demonstrated a similar relationship between emotional intensity and level of caricature for six different facial expressions. Experiments 3 and 4 compared intensity ratings of facial expression caricatures prepared relative to a selection of reference norms - a neutral expression, an average expression, or a different facial expression (e.g. anger caricatured relative to fear). Each norm produced a linear relationship between caricature and rated intensity of emotion; this finding is inconsistent with two-dimensional models of the perceptual representation of facial expression. An exemplar-based multidimensional model is proposed as an alternative account.


Assuntos
Caricaturas como Assunto , Emoções , Expressão Facial , Reconhecimento Visual de Modelos , Adulto , Aprendizagem por Discriminação , Feminino , Humanos , Masculino , Percepção Social
16.
Psychoneuroendocrinology ; 12(2): 149-58, 1987.
Artigo em Inglês | MEDLINE | ID: mdl-3602262

RESUMO

The endocrine, genital, and cognitive--affective responses of sexually functional men were compared under sexually arousing and non-arousing conditions. Sexually aroused subjects showed significantly higher serum luteinizing hormone concentrations than non-aroused subjects. Testosterone concentration was correlated with higher levels of penile response, but it did not prime further sexual arousal. Cortisol and prolactin concentrations decreased in both groups, more in the non-aroused group, and appeared to both inhibit and facilitate sexual response, depending on the level of anxiety reported by the subjects. Cortisol was correlated with self-reported worry, and testosterone with relaxation. These results support a multidimensional approach to the endocrine study of sexual arousal that includes both cognitive and genital response components.


Assuntos
Nível de Alerta/fisiologia , Hormônios Esteroides Gonadais/sangue , Ereção Peniana , Comportamento Sexual/fisiologia , Adolescente , Adulto , Afeto/fisiologia , Humanos , Hidrocortisona/sangue , Hormônio Luteinizante/sangue , Masculino , Prolactina/sangue , Testosterona/sangue
17.
Psychoneuroendocrinology ; 21(6): 545-58, 1996 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-8983090

RESUMO

We have repeated a study of the objective (labium minus temperature) and subjective (semantic scales) changes in sexual arousability over the menstrual cycle to erotic video stimulation in 20 women with natural cycles. We extended the study with concomitant vibrotactile stimulation of the clitoral region. In an earlier study women tested for the first time in their follicular phase were sexually more aroused (as indicated by greater increase in labium minus temperature) than women tested for the first time during their luteal phase. When these women were retested in their alternative phase of the menstrual cycle, those who were then follicular did not score higher than those who were then luteal. We then postulated the involvement of a cognitive or conditioned phenomenon which was responsible for the women's repeating their initial phase-dependent response when tested the second time in their alternative phase of the cycle. Identical results were obtained in the present study as far as sexual arousability is concerned during the first test, i.e. follicular women generally scored higher than luteal women; this difference in response persisted during the second test. Concomitant vibrotactile stimulation had no effect on labium minus temperature change but raised subjective sexual arousal and caused a 'more pleasurable' response to the erotic video. Subjective sexual and subjective genital arousal were positively correlated, but neither was significantly correlated with labium minus temperature change. The relationship between menstrual cycle phase and sexual arousal was further substantiated by the reported greater increase in sexual desire after the first erotic video in follicular women than in luteal women. This increased desire, as well as more erotic fantasies, persisted during the next 24 h. In conclusion, studies into effects of menstrual cycle phase on sexual arousability in the laboratory should seriously consider the possible learning and conditioning effects as suggested by the present investigation.


Assuntos
Libido/fisiologia , Ciclo Menstrual/fisiologia , Comportamento Sexual/fisiologia , Adolescente , Adulto , Feminino , Humanos , Pessoa de Meia-Idade , Progesterona/sangue , Temperatura Cutânea/fisiologia
18.
Invest Radiol ; 30(6): 341-4, 1995 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-7490185

RESUMO

RATIONALE AND OBJECTIVES: Infection is a serious complication of metallic prosthesis implantation and may necessitate removal of the prosthesis. This study uses an animal model to evaluate the effects of coating stainless steel wire implants with fibrinolytic agents to prevent infection after bacterial contamination. METHODS: Three types of steel wire implants were used: plain stainless steel, heparin-coated steel, and urokinase-heparin-coated steel. Wire implants were incubated in a known concentration of Staphylococcus epidermidis and placed into the subcutaneous tissues of three groups of anesthetized hamsters. The implants and surrounding tissues were excised after 1 week and submitted for quantitative cultures. RESULTS: Using 100 organisms as the upper allowable limit to categorize abscesses as noninfected, the following rates of noninfectivity were observed: group 1 (control), 0% noninfected; group 2 (heparin-coated wire), 40% noninfected; and group 3 (urokinase-heparin-coated wire), 50% noninfected. The noninfectivity rates of groups 2 and 3 were significantly higher than the rate of group 1 (P < 0.001). There was no significant difference between groups 2 and 3 (P = 0.19). CONCLUSIONS: Both the heparin-coated and urokinase-heparin-coated wire exhibited significantly decreased infection rates compared with uncoated wire; the heparin coating may inhibit bacterial adherence. The urokinase coating of the heparin-coated wire appears to further decrease the infection rate, but not to a statistically significant degree.


Assuntos
Fibrinolíticos/uso terapêutico , Heparina/uso terapêutico , Ativadores de Plasminogênio/uso terapêutico , Próteses e Implantes , Infecções Relacionadas à Prótese/prevenção & controle , Aço Inoxidável , Infecções Estafilocócicas/prevenção & controle , Staphylococcus epidermidis , Ativador de Plasminogênio Tipo Uroquinase/uso terapêutico , Abscesso/microbiologia , Abscesso/prevenção & controle , Animais , Aderência Bacteriana/efeitos dos fármacos , Fios Ortopédicos , Contagem de Colônia Microbiana , Tecido Conjuntivo/cirurgia , Cricetinae , Procedimentos Cirúrgicos Dermatológicos , Modelos Animais de Doenças , Contaminação de Equipamentos , Fibrinolíticos/administração & dosagem , Heparina/administração & dosagem , Ativadores de Plasminogênio/administração & dosagem , Staphylococcus epidermidis/isolamento & purificação , Propriedades de Superfície , Ativador de Plasminogênio Tipo Uroquinase/administração & dosagem
19.
J Am Geriatr Soc ; 45(11): 1352-9, 1997 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9361661

RESUMO

OBJECTIVE: To present and evaluate an instrument, the Telephone Cognitive Assessment Battery (TCAB), designed to be administered over the telephone to assess the cognitive status of older individuals. The TCAB addresses mental status, reasoning and executive ability, primary and secondary memory, and language. It consists of six neuropsychological tests and takes approximately 15 to 20 minutes to complete. DESIGN: The instrument is evaluated with a comparative cross-sectional design, with data collected both prospectively and retrospectively. SETTING: The University Hospitals of Cleveland/Case Western Reserve University Alzheimer Center Research Registry. PARTICIPANTS: Forty Alzheimer's Disease cases selected from among those most recently recruited into the Registry and 40 cognitively intact Registry controls. Controls were selected randomly so that the two groups had similar distributions of age, sex, and education. MEASUREMENTS: The cognitive status of all participants was assessed utilizing both the TCAB and the usual in-person Registry evaluation, which includes medical history data and in-person assessment of cognitive status. In order to measure the potential learning effect of repeated testing, half of the cases and half of the controls were recruited and assessed over the telephone with the TCAB before their in-person Registry evaluation (with a waiting period of at least 2 weeks between evaluations), whereas the other two halves received the TCAB after they had become part of the Registry. The TCAB was administered to all participants by a single investigator. Two clinical evaluators, blinded to the Registry diagnosis of the subjects, independently classified the subjects as cognitively impaired, normal, or questionable on the basis of the results of the TCAB and a brief listing of medical illness and depressive symptoms. A final classification was achieved through consensus and subsequently compared with the Registry diagnosis, taken here to be the gold standard. RESULTS: Test scores of subjects assessed by TCAB before receiving the in-person assessment were compared with those of subjects receiving the in-person assessment first. There were no significant differences between mean scores of the two groups (those with TCAB first and those with TCAB last) for either cases or normal controls. High values of the kappa statistic were obtained for the two initial evaluators of the TCAB classification, demonstrating excellent interrater reliability. Regarding the reconciled TCAB classification, the ability of the TCAB to correctly classify subjects according to cognitive status, while controlling for potential confounders such as age and educational level, was assessed by means of discriminant analysis techniques. Knowledge of the TCAB classification and age allowed the correct classification of 95% of the participants; this was not significantly improved by knowledge of other potential determinants. Sensitivity and specificity were calculated under two schema for classifying those subjects in the "questionable" category. Positive and negative predictive values of the TCAB were computed assuming a prevalence of cognitive impairment of 10% in the older population. High negative predictive values (over 99%) were obtained under both schema, whereas the positive predictive values were seen to be more dependent on the classification of questionables. CONCLUSION: Research studies involving ascertainment of cognitive status of older people, particularly those that require periodic follow-up, such as those focusing on healthy aging, commonly suffer from lack of representativeness of subjects, often brought about by problems related to mobility of potential participants. It is also crucial that normal individuals who are recruited initially to serve as controls in epidemiologic studies of dementing illnesses be reevaluated periodically, and this may be hindered by the same obstacles. (ABSTRACT TRUNCATED)


Assuntos
Transtornos Cognitivos/diagnóstico , Programas de Rastreamento/métodos , Vigilância da População/métodos , Idoso , Estudos de Casos e Controles , Transtornos Cognitivos/epidemiologia , Intervalos de Confiança , Estudos Transversais , Humanos , Testes Neuropsicológicos , Valor Preditivo dos Testes , Estudos Prospectivos , Reprodutibilidade dos Testes , Sensibilidade e Especificidade , Telefone
20.
J Am Geriatr Soc ; 48(7): 800-6, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10894320

RESUMO

OBJECTIVES: To study the association between cigarette smoking and Alzheimer's Disease (AD). DESIGN: Intrafamily case-control, with sibling controls and a variable number of controls per case. SETTING: AD cases were identified through the Research Registry of the University Hospitals of the Cleveland/Case Western Reserve University Alzheimer Center. PARTICIPANTS: Study subjects were 86 probable AD cases (index cases) and all of their full siblings, alive or dead, aged > or = 50 years, a total of 238 subjects. MEASUREMENTS: Exposure for each individual was ascertained with a questionnaire answered by several informants. Cognitive status of siblings of the AD cases (impaired or intact) was ascertained by telephone using validated instruments. Diagnosis of dementia in cognitively impaired siblings of index cases was not attempted. RESULTS: Chi-square analysis tested for departure from a random distribution of disease across smokers and nonsmokers within families. No significant departure was found utilizing all families (P > .40) nor utilizing those families where only the index case was affected (P > .90). Conditional logistic regression evaluated the association within families, controlling for age, sex, and education. Analyses both included and excluded secondary cases of cognitive impairment. No association was found between smoking and disease (OR = 1.26; 95% confidence interval, 0.66-2.42, and OR = 1.42; 95% confidence interval, 0.69-2.89, respectively). CONCLUSIONS: No significant association was found between smoking and cognitive status. Further, analyses based on the comparison of persons with AD with their unaffected siblings also suggest that smoking does not decrease the risk of AD.


Assuntos
Doença de Alzheimer/etiologia , Fumar/efeitos adversos , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/epidemiologia , Estudos de Casos e Controles , Intervalos de Confiança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Testes Neuropsicológicos , Núcleo Familiar , Ohio
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