828 resultados para undergraduate laboratory


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rockburst is characterized by a violent explosion of a block causing a sudden rupture in the rock and is quite common in deep tunnels. It is critical to understand the phenomenon of rockburst, focusing on the patterns of occurrence so these events can be avoided and/or managed saving costs and possibly lives. The failure mechanism of rockburst needs to be better understood. Laboratory experiments are undergoing at the Laboratory for Geomechanics and Deep Underground Engineering (SKLGDUE) of Beijing and the system is described. A large number of rockburst tests were performed and their information collected, stored in a database and analyzed. Data Mining (DM) techniques were applied to the database in order to develop predictive models for the rockburst maximum stress (σRB) and rockburst risk index (IRB) that need the results of such tests to be determined. With the developed models it is possible to predict these parameters with high accuracy levels using data from the rock mass and specific project.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The sand fly Lutzomyia cruzi is considered as one of vectors of visceral leishmaniasis in Brazil. This work examined optimum feeding age, feeding time, host preference, fecundity rates, and female blood meal volume taken by single females from a closed colony of L. cruzi. Mean feeding time was longer on hamsters, 6.6 minutes, than on humans, 5.7 minutes. 49.1% of the 48h-old flies fed on humans and 43.3% of 72h-old flies fed on hamsters. Of a total of 120 females, 61% fed on humans and 25% fed on hamsters. Total fecundity was significantly higher in females fed on hamster than on human or opossum. Laboratory-reared L. cruzi females fed earlier, more promptly, and preferably on humans than on hamsters when offered these blood-meal sources simultaneously. The blood-meal volume is higher in females fed on hamsters than other hosts (human and opossum).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: Theoretical and empirical analysis of items and internal consistency of the Portuguese-language version of Social Phobia and Anxiety Inventory (SPAI-Portuguese). METHODS: Social phobia experts conducted a 45-item content analysis of the SPAI-Portuguese administered to a sample of 1,014 university students. Item discrimination was evaluated by Student's t test; interitem, mean and item-to-total correlations, by Pearson coefficient; reliability was estimated by Cronbach's alpha. RESULTS: There was 100% agreement among experts concerning the 45 items. On the SPAI-Portuguese 43 items were discriminative (p < 0.05). A few inter-item correlations between both subscales were below 0.2. The mean inter-item correlations were: 0.41 on social phobia subscale; 0.32 on agoraphobia subscale and 0.32 on the SPAI-Portuguese. Item-to-total correlations were all higher then 0.3 (p < 0.001). Cronbach's alphas were: 0.95 on the SPAI-Portuguese; 0.96 on social phobia subscale; 0.85 on agoraphobia subscale. CONCLUSION: The 45-item content analysis revealed appropriateness concerning the underlying construct of the SPAI-Portuguese (social phobia, agoraphobia) with good discriminative capacity on 43 items. The mean inter-item correlations and reliability coefficients demonstrated the SPAI-Portuguese and subscales internal consistency and multidimensionality. No item was suppressed in the SPAI-Portuguese but the authors suggest that a shortened SPAI, in its different versions, could be an even more useful tool for research settings in social phobia.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: To determine if abnormal laboratory findings are more common in individuals with hypertension and in those with other risk factors, such as obesity, smoking and alcohol ingestion. METHODS: A study was carried out in the general outpatient clinics of a university hospital (145 individuals without previous diagnosis of hypertension) and the following variables were assessed: high blood pressure (as defined by the VI Joint National Committee on Prevention, Detection and Treatment of High Blood Pressure - VI JNC), obesity [calculated using body mass index (BMI)], tobacco use, and alcoholic ingestion. The laboratory examinations consisted of the following tests: hemogram, glycemia, uric acid, potassium, total/HDL-fraction cholesterol, triglycerides, calcium and creatinine. RESULTS: High blood pressure was not associated with a higher number of abnormal laboratory tests. Hypertensive individuals with a BMI > or = 25kg/m² or normotensive obese individuals, however, had a higher frequency of diabetes (12X), hypertriglyceridemia (3X), and hypercholesterolemia (2X), as compared with hypertensive individuals with BMI <25kg/m² and preobese/normal weight normotensive individuals. CONCLUSION: High blood pressure is not associated with a higher frequency of abnormal laboratory tests. The association of high blood pressure and obesity, however, increases the detection of diabetes and dyslipidemias.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: To determine the frequency of hypothyroidism in a sample of hyperlipemic patients and evaluate clinical and laboratory factors indicative of thyropathy among them. METHODS: Fifty-one hyperlipemic patients, grouped according to an earlier or recent diagnosis of their thyroid function into euthyroid and hypothyroid, were evaluated with clinical and laboratory examinations of blood levels of free T4 and TSH (by radioimmunoassay). Patients were on average 46.8±11.7 years old, predominantly of the female sex (62.5%); 31% had a previous diagnosis of hypothyroidism and were under treatment with thyroxin. RESULTS: Fourteen three percent of patients analyzed had hypothyroidism, which had not been detected before. Differentiating attributes of the groups analyzed were: a predominance of females among the hypothyroid patients and a higher HDL serum concentration among those recently diagnosed. CONCLUSION: In the present study, new cases of hypothyroidism in hyperlipemic patients were a frequent occurrence, yet few clinical and laboratory data except tests evaluating free T4 and TSH in the blood indicated which patients had thyroid dysfunction.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: To report a training program in cardiology emphasizing changes in its pedagogical practice. These changes were put into practice by some teachers at the Medical School of Porto Alegre of the University of Rio Grande do Sul (FAMED/UFRGS) aiming to make faculty and student activities more dynamic and to promote more efficacious learning. The training program is directed at 5th semester medical students and aims at a behavioral change in teachers and students to promote more interaction, to favor exchanges, and to make the teaching-learning process easier, always maintaining the patient in the center of the medical activity. METHODS: The program emphasizes the definition of general and specific objectives for each activity to be developed by the students, with training in the area of admission to the cardiology service, with special emphasis on behavioral change in the cognitive, motor, affective, and attitudinal areas. Knowledge was developed by means of interactive seminars with initial and final assessment tests to identify students' and teachers' performance. The students were evaluated in an immediate, continuous, and progressive way in their daily activities and through comparison of the results of 2 tests, one applied at the beginning of the training and the other at its end. These 2 tests contained the same questions. RESULTS: We systematically assessed 560 students over 4 years. The mean grades of the tests performed prior to and after the 244 seminars were 7.38±1.66 and 9.17± 0.82, respectively (p<0.0001). For the tests applied at the beginning and at the end of the training, the mean grades were 5.61±1.61 and 9.37±0.90, respectively (p<0.0001). CONCLUSION: The program proved to be efficient both for the students' learning and for assessing their performance in a systematic and objective way.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

OBJECTIVE: To verify the association of serum markers of myocardial injury, such as troponin I, creatinine kinase, and creatinine kinase isoenzyme MB, and inflammatory markers, such as tumor necrosis factor alpha (TNF-alpha), C-reactive protein, and the erythrocyte sedimentation rate in the perioperative period of cardiac surgery, with the occurrence of possible postpericardiotomy syndrome. METHODS: This was a cohort study with 96 patients undergoing cardiac surgery assessed at the following 4 different time periods: the day before surgery (D0); the 3rd postoperative day (D3); between the 7th and 10th postoperative days (D7-10); and the 30th postoperative day (D30). During each period, we evaluated demographic variables (sex and age), surgical variables (type and duration , extracorporeal circulation), and serum dosages of the markers of myocardial injury and inflammatory response. RESULTS: Of all patients, 12 (12.5%) met the clinical criteria for a diagnosis of postpericardiotomy syndrome, and their mean age was 10.3 years lower than the age of the others (P=0.02). The results of the serum markers for tissue injury and inflammatory response were not significantly different between the 2 assessed groups. No significant difference existed regarding either surgery duration or extracorporeal circulation. CONCLUSION: The patients who met the clinical criteria for postpericardiotomy syndrome were significantly younger than the others were. Serum markers for tissue injury and inflammatory response were not different in the clinically affected group, and did not correlate with the different types and duration of surgery or with extracorporeal circulation.