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排序方式: 共有244条查询结果,搜索用时 15 毫秒
161.
Industrial radiography is the process of using either gamma-emitting radionuclide sources or X-ray machines to examine the safety of industrial materials. Industrial radiographers are among the radiation workers who receive the highest individual occupational radiation doses. To assess occupationally induced chromosomal damage, we performed the cytokinesis-block micronucleus (CBMN) assay in peripheral lymphocytes of 29 male industrial radiographers, exposed to ionizing radiation for 12.8 years+/-11.2, in comparison with 24 gender-, age-, and smoking habits-matched controls. The CBMN assay was combined with fluorescent in situ hybridization with a pan-centromeric DNA probe in 17 exposed subjects and 17 controls randomized from the initial populations. The mean cumulative equivalent dose, recorded by film dosimeters, was 67.2 mSv+/-49.8 over the past 5 years. The mean micronucleated binucleated cell rate (MCR) was significantly higher in the industrial radiographers than in the controls (10.7 per thousand +/-5.2 versus 6.6 per thousand +/-3.1, P=0.009); this difference was due to a significantly higher frequency of centromere-negative micronuclei (C-MN) in exposed subjects than in controls (8.5 per thousand +/-4.9 versus 2.2 per thousand +/-1.6, P<0.001). The two populations did not significantly differ in centromere-positive micronuclei (C+MN) frequency. These findings demonstrate a clastogenic effect in lymphocytes of industrial radiographers. MCR significantly positively correlated with age in the two groups. After correction for the age effect, MCR did not correlate with duration of occupational exposure. No correlation between radiation doses and MCR, C-MN, and C+MN frequencies was observed. In addition to physical dosimetry records, the enhanced chromosomal damage in lymphocytes of industrial radiographers emphasizes the importance of radiation safety programs. 相似文献
162.
C Giavoli V Cappiello S Porretti C L Ronchi E Orsi P Beck-Peccoz M Arosio 《Hormones et métabolisme》2003,35(9):557-561
In the present report, we have compared 12 months of rhGH therapy given daily (D) at the beginning and then on alternate days (A) to 20 subjects with severe adult-onset GH deficiency (GHD). Aim of the study was to establish whether the lower frequency injection regimen is as effective as the daily dose. Measurements included: IGF-I levels, body composition (BF%), lipid profile, insulin sensitivity by homeostasis model assessment (HOMA-IR) and quantitative insulin check index (QUICKI), as well as thyroid function. Evaluation on A therapy was performed both 12 and 36 hours after the last rhGH injection. The final rhGH dose was 0.3 +/- 0.1mg/day. During A, the dose used in D was doubled and given on alternate days. Recombinant hGH given during the A period induced changes in IGF-I levels, BF% and lipid profile comparable to daily treatment. HOMA-IR increased similarly after both regimens, though QUICKI did not significantly change. A significant reduction in serum FT4 levels occurred after both D and A therapy, so that an adjustment of L-T4 replacement dose in 5 of 20 patients was necessary. No differences were found in the various parameters after 12 and 36 hours post rhGH injection. In conclusion, rhGH therapy given on alternate days is clinically effective and may result in improved patient compliance. Monitoring glucose tolerance and thyroid function while on rhGH is essential. 相似文献
163.
Stefanini MA Orsi AM Gregório EA Viotto MJ Baraldi-Artoni SM 《Journal of morphology》1999,242(3):247-255
The efferent ductules of the pigeon are localized in the epididymal region and are topographically divided into proximal and distal, both portions being lined with stereociliated pseudostratified epithelium. Transmission electron microscopy shows five distinct cell types: light, dark, and angular non-ciliated cells with possible apocrine secretory role cells and halo cells, possibly intraepithelial leucocytes. The proximal efferent ductules have the widest diameter among all ductules in the epididymal region. 相似文献
164.
Piera Valenti Paolo Visca Giovanni Antonini Nicola Orsi 《FEMS microbiology letters》1986,33(2-3):271-275
Abstract The mechanism of antifungal activity of lactoferrin (Lf) and ovotransferrin (OTR) towards Candida albicans and Candida krusei was studied. In low iron-content medium, in minimal medium supplemented by 2,2'-dipyridyl, and in a medium in which Lf or OTR were separated from the culture by a dialysis membrane, the growth of C. albicans and C. krusei was proportional to the endogenous iron. Differences were observed when Lf or OTR was in contact with the fungal cells: C. albicans was inhibited, whereas C. krusei was not. Direct fluorescence indicated binding of Lf and OTR only on C. albicans surfaces, and suggested that antifungal activity is not simply related to iron deprivation, but involves interaction of the protein with the fungal surface. 相似文献
165.
Nitroreductase activity of NADH dehydrogenase of the respiratory redox chain. 总被引:1,自引:0,他引:1
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1. An NADH-dependent nitroreductase from the inner membrane of ox liver mitochondria copurified with Complex I of the respiratory redox chain (NADH:ubiquinone oxidoreductase, EC 1.6.5.3). 2. The corresponding nitroreductase from ox heart mitochondria co-purified with the NADH-cytochrome c reductase of Mahler, Sarkar & Vernon [(1952) J. Biol. Chem. 199, 585-597] [NADH: (acceptor) oxidoreductase, EC 1.6.99.3], a component of Complex I that contains the FMN. 3. The mitochondrial nitroreductase activity is attributed to the flavoprotein component of Complex I. 相似文献
166.
Objective
To assess the association between unhealthy dietary habits and cognition in older adults from Southern Brazil.Methods
This cross-sectional study analyzed data from the second wave of a population- and household-based epidemiological survey (2013–2014) conducted in the city of Florianópolis. A total of 1,197 older adults (778 women) over 60 years old participated in the study. Cognition, the dependent variable, was measured by the Mini-Mental State Examination (MMSE). The independent variables were the following indicators of unhealthy dietary habits: low intake of fruits and vegetables (≤ 4 servings/day); fish (< 1 serving/week); and habitual fatty meat intake (yes/no). Adjustments were made for age, education level, income, smoking status, alcohol intake, leisure-time physical activity, depression symptoms, chronic diseases, and body mass index. Simple and multiple linear regression analyses were performed, considering sampling weights and stratification by gender.Results
The mean MMSE scores for men and women were 25.15 ± 5.56 and 24.26 ± 5.68, respectively (p = 0.009). After adjustments, in women low fruit and vegetable intake (≤ 4 servings/day) was independently associated with the lowest MMSE scores. No associations were found in men. Additionally, women’s mean MMSE scores increased as their daily frequency of fruit and vegetable intake increased (p = 0.001).Conclusion
Women with low fruit and vegetable intake according to the World Health Organization (WHO) have lower cognition scores. Regular intake of fruits, vegetables, and fish in exchange of fatty meats may be a viable public policy strategy to preserve cognition in aging. 相似文献167.
Alexander D. Orsi Srinath Chakravarthy Paul K. Canavan Estefanía Peña Ruben Goebel Askhan Vaziri 《Computer methods in biomechanics and biomedical engineering》2016,19(5):493-506
This study determined which knee joint motions lead to anterior cruciate ligament (ACL) rupture with the knee at 25° of flexion. The knee was subjected to internal and external rotations, as well as varus and valgus motions. A failure locus representing the relationship between these motions and ACL rupture was established using finite element simulations. This study also considered possible concomitant injuries to the tibial articular cartilage prior to ACL injury. The posterolateral bundle of the ACL demonstrated higher rupture susceptibility than the anteromedial bundle. The average varus angular displacement required for ACL failure was 46.6% lower compared to the average valgus angular displacement. Femoral external rotation decreased the frontal plane angle required for ACL failure by 27.5% compared to internal rotation. Tibial articular cartilage damage initiated prior to ACL failure in all valgus simulations. The results from this investigation agreed well with other experimental and analytical investigations. This study provides a greater understanding of the various knee joint motion combinations leading to ACL injury and articular cartilage damage. 相似文献
168.
Inhibitory effect of selected lactic acid bacteria on microflora associated with ready-to-use vegetables 总被引:1,自引:0,他引:1
The addition of selected lactic acid bacteria strains had a remarkable inhibitory effect on the growth dynamics of microflora associated with ready-to-use vegetables, during refrigerated storage. In particular, coliforms and enterococci were strongly reduced or eliminated from the products from the third day of storage. Lactobacillus casei strains proved more effective than pediococci. The use of lactic cultures able to produce bacteriocins and to grow at low temperatures could be a useful tool to preserve fresh vegetables and to ensure their microbiological safety. 相似文献
169.
M D Pai S M Dias A M Orsi G Seullner V D Pai 《Gegenbaurs morphologisches Jahrbuch》1990,136(6):753-757
Capsular veins of 36 kidneys in cat (Felis domestica) have been investigated on macroscopical level. There are venous shunts on the superficial renal level which occur in both surfaces (dorsal and ventral) and different pathways of these vessels for comparative diagnosis. The collateral renal circulation may be sufficient to maintain the renal vascularization in stress conditions. 相似文献
170.
A M Vicari S Viganó D'Angelo S Testa G Comi G Galardi E Orsi A D'Angelo 《Hormones et métabolisme》1992,24(11):516-519
The fibrinolytic system was investigated in 38 patients (21 males and 17 females) affected by type 1 diabetes mellitus (18 free from complications, 10 with retinopathy, and 10 with autonomic neuropathy) and in 8 healthy controls. Two separate fibrinolysis-stimulating tests were done: standardized venous occlusion and 1-desamino-8-D-arginine vasopressin infusion. Plasma tissue plasminogen activator antigen and activity and plasma plasminogen activator inhibitor activity were measured. All the patients were in good metabolic control (mean HbA1c 7.4%, range 6.1-8.0%). No significant differences were observed either between the diabetic patients and the control subjects, nor among the subgroups of diabetic patients. The fibrinolytic system is probably not involved in type 1 diabetes mellitus. 相似文献