腹主动脉瘤中定常流动的三维数值模拟

目的讨论定常流动情况下，三维腹主动脉瘤模型内的流动情况。方法应用三维非对称模型进行数值模拟。结果结果表明，在对称面上有一个涡而横截面上有两对涡的存在。壁面切应力在动脉瘤的出口处数值较高且变化大。结论流动和壁面切应力分布反应动脉瘤出口处为破裂的危险区域。     

Reactive Sintering of Dysprosium-Iron Garnet via a Perovskite-Hematite Solid State Reaction and Physical Properties of the Material

In this paper, we report on a successful synthesis of dysprosium iron garnet Dy₃Fe₅O₁₂ (DyIG) by a reactive synthesis method involving dysprosium iron perovskite and hematite. Phase formation was traced using dilatometry, and XRD measurements attested to the formation of the desired structure. Samples with relative density close to 97% were fabricated. The samples were characterized using vibrating sample magnetometry, dielectric spectroscopy, and UV-Vis-NIR spectroscopy. Magnetic properties were probed in temperatures between 80 and 700 K with a maximum applied field of 1 kOe. The measurements revealed several effects: the compensation of magnetic moments at a certain temperature, the inversion of the magnetocaloric effect, and the ability to measure the Curie temperature of the material. Activation energy was determined from UV-Vis-NIR and dielectric spectroscopy measurements. Characteristic magnetic temperatures and activation energy values of the samples were similar to bulk DyIG obtained using other methods.     

二苯乙烯类化合物对蛋白激酶C的抑制作用

报道15种二苯乙烯类化合物对蛋白激酶C(PKC)活性的影响。其中从中药金雀根中分得的3种二苯乙烯类低聚体α-viniferin,kobophenol A 和 miyabenolC,它们抑制PKC的IC₅₀分别为62.5,52.0和27.5μmol·L^-1。另外6种含酚羟基的二苯乙烯化合物对PKC也显示不同程度的抑制作用,但当酚羟基全甲基化或全乙酰化后其抑制作用大大降低甚至消失。酶动力学研究证明miyabenolC对PKC的抑制作用属于非竞争性抑制。     

Activation of Akt is increased in the dysplasia-carcinoma sequence in Barrett's oesophagus and contributes to increased proliferation and inhibition of apoptosis: a histopathological and functional study

Background  

The incidence of oesophageal adenocarcinoma is increasing rapidly in the developed world. The serine-threonine protein kinase and proto-oncogene Akt has been reported to regulate proliferation and apoptosis in several tissues but there are no data on the involvement of Akt in oesophageal carcinogenesis. Therefore we have examined the activation of Akt in Barrett's oesophagus and oesophageal adenocarcinoma and the functional effects of Akt activation in vitro.     

Validation of a patient-administered questionnaire to measure the severity and bothersomeness of lower urinary tract symptoms in uncomplicated urinary tract infection (UTI): the UTI Symptom Assessment questionnaire

OBJECTIVE: To develop and validate a self-administered questionnaire to assess the 'severity' and 'bothersomeness' of the most frequently reported signs and symptoms of uncomplicated urinary tract infection (uUTI). SUBJECTS AND METHODS: The UTI Symptoms Assessment questionnaire (UTISA) is a 14-item instrument asking about the severity and bothersomeness of seven key uUTI symptoms. It was developed after comprehensive literature and data review and administration in draft form to a sample of 30 women with uUTI. The final questionnaire was completed by 276 women with uUTI who participated in a noncomparative clinical trial of ciprofloxacin. The women completed the questionnaire in electronic format at baseline (before the first dose of ciprofloxacin once-daily), at 3-h and 8-h intervals until all UTI symptoms were resolved, and at the test-of-cure visit. Baseline scores on the King's Health Questionnaire (KHQ) were used to assess convergent and divergent validity; responses to the Global Rating of Change (GRC) were used to assess both responsiveness and the 'minimally important difference'. Discriminant validity and responsiveness were assessed by comparing UTISA scores with a clinical evaluation of UTI symptoms performed by the investigator at baseline and at the test-of-cure visit. RESULTS: The UTISA was found to comprise three four-item domains named 'urination regularity', 'problems with urination', and 'pain associated with UTI'. Two questions asking about haematuria loaded on a fourth factor. The three domains were homogeneous (with high inter-item correlations) and internally consistent. Convergent validity was shown by high correlations between similar UTISA and KHQ domains (all r(s) > 0.40), and divergent validity by small correlations between unlike domains (all r(s) < 0.15). In general, the UTISA domains showed excellent discriminant validity, with scores on selected domains discriminating between women with different clinical evaluations. The responsiveness of the UTISA was also excellent, with high correlations between changes in domain scores and the clinical evaluation and GRC items. Symptom improvement was highest in the first 3 h, leading to greater responsiveness and minimally important difference during this period. However, the UTISA could detect even small subsequent changes. CONCLUSION: The three-domain UTISA has excellent psychometric properties and it is likely to prove an excellent tool for assessing uUTI outcome from a patient's perspective, both in research and clinical settings.     

Volume expansion with albumin decreases mortality after coronary artery bypass graft surgery

OBJECTIVES: Albumin and nonprotein colloids (starches, dextran, and others) are used frequently as blood volume expanders in coronary artery bypass graft (CABG) surgery. The objective of this study was to determine differences between colloids with regard to patient characteristics and mortality rates. DESIGN AND SETTING: Discharge data collected in the Solucient Clinical Pathways Database from 19,578 patients undergoing CABG surgery were analyzed. MEASUREMENTS: Patients receiving albumin and nonprotein colloids were compared with regard to baseline patient characteristics. A multiple regression model was developed to determine if albumin use was independently associated with mortality rates. RESULTS: Albumin was used in 8,084 cases (41.3%). The use of albumin and nonprotein colloids was not related to patient characteristics. Mortality was lower in the albumin group compared to the nonprotein colloid group (2.47% vs 3.03%, p = 0.02). In the multivariable logistic regression analysis, albumin use was associated with 25% lower odds of mortality compared to nonprotein colloid use (odds ratio, 0.80; 95% confidence interval, 0.67 to 0.96). CONCLUSION: Colloid administration in CABG surgery was unrelated to patient characteristics. Albumin use appears to be associated with lower incidence of mortality after CABG surgery compared to nonprotein colloid use.