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排序方式: 共有218条查询结果,搜索用时 109 毫秒
1.
A Cecile J W Janssens Yurii S Aulchenko Stefano Elefante Gerard J J M Borsboom Ewout W Steyerberg Cornelia M van Duijn 《Genetics in medicine》2006,8(7):395-400
PURPOSE: There is ongoing debate about whether testing low-risk genes at multiple loci will be useful in clinical care and public health. We investigated the usefulness of multiple genetic testing using simulated data. METHODS: Usefulness was evaluated by the area under the receiver-operating characteristic curve (AUC), which indicates the accuracy of genetic profiling in discriminating between future patients and nonpatients. The AUC was investigated in relation to the number of genes assumed to be involved, the risk allele frequency, the odds ratio of the risk genotypes, and to the proportion of variance explained by genetic factors as an approximation of the heritability of the disease. RESULTS: We demonstrated that a high (AUC > 0.80) to excellent discriminative accuracy (AUC > 0.95) can be obtained by simultaneously testing multiple susceptibility genes. A higher discriminative accuracy is obtained when genetic factors play a larger role in the disease, as indicated by the proportion of explained variance. The maximum discriminative accuracy of future genetic profiling can be estimated at present from the heritability and prevalence of disease. CONCLUSIONS: Genetic profiling may have the potential to identify individuals at higher risk of disease depending on the prevalence and heritability of the disease. 相似文献
2.
Daniel Hork Franti eksvec Jaroslav Klal Arnold A. Adamyan Yurii D. Volynskii Olga S. Voronkova Leonid S. Kokov Klara Z. Gumargalieva 《Biomaterials》1986,7(6):467-470
In this study we report the results of clinical experiments, obtained with spherical particles made from poly(2-hydroxyethyl methacrylate) used in the embolization of arteriovenous anastomoses, in the suppression of pulmonary haemorrhage and haemoptysis and in the occlusion of some other arteries. So far we have used these particles in the treatment of 187 patients. It must be stressed that the advantage of spherical particles consists in the simplicity of their introduction into the blood vessel through a catheter, while in the blood vessel itself the particle swells in blood still more, when compared with the particle size in saline. This results in an immediate and permanent haemostatic effect. No revascularization occurs. 相似文献
3.
Gennadii D. Bukatov Sergei H. Shepelev Vladimir A. Zakharov Sergei A. Sergeev Yurii I. Yermakov 《Macromolecular chemistry and physics.》1982,183(11):2657-2665
By use of the quenching technique with 14CO and 14CO2 the number of active centers and the propagation rate constants (kp) were determined for the propylene polymerization on different titanium-magnesium catalysts in the presence and absence of an organoaluminium cocatalyst. The kp values at 70°C were found to be 500–1000 1·mol?1·s?1, which were confirmed by independent data of molecular mass measurements of the isotatic polymer after a short polymerization time (5 s). Similar isotactic and atactic kpvalues were found. The maximum number of active centers for supported titanium-magnesium catalysts can reach about 10% of the titanium content in the catalyst. The kp values of ethylene polymerization on catalysts active without an organoaluminium cocatalyst were also determined (≈ 104 l·mol?1·s?1 at 70°C). 相似文献
4.
Sergey V. Lindeman Igor I. Ponomaryov Nikolai I. Raevsky Yurii T. Struchkov Alexandr L. Rusanov 《Macromolecular chemistry and physics.》1994,195(2):555-570
The X-ray structural investigation of the naphthoylenebis-(benzimidazole) ( 1 ) cis- and trans-isomers as models for the cis and trans elementary units of the corresponding poly(naphthoylene-benzimidazoles) (PNBI) was carried out. The correctness of the previous identification of the isomers was confirmed, and exact geometrical parameters of the PNBI elementary units (required, in particular, for the calculation of the Kuhn segment of PNBI) were determined. Quantum-chemical semi-empirical calculations of the ground and excited electronic states of the isomers were carried out. Both experimental and theoretical data confirm a larger stability of the planar π-conjugated structure of the trans-isomer in comparison with the cis-isomer in the ground as well as in the excited electronic state. Crystals of the cis- and trans-isomers obtained from trifluoroacetic acid solutions are the solvates of bis(trifluoroacetates) of diprotonated 1 with an extremely high content of the solvating trifluoroacetic acid. This peculiarity is favourable for modelling the main characteristics of the interaction between PNBI and protonic polar solvent molecules, viz. preferred types of H-bonding and a possibility of interaction of the electronic lone pairs of the solvent molecules with the π-electronic systems of the elementary units of PNBI by charge transfer complexes. 相似文献
5.
6.
Goodman MT Shvetsov YB McDuffie K Wilkens LR Zhu X Ning L Killeen J Kamemoto L Hernandez BY 《The Journal of infectious diseases》2008,197(7):957-966
BACKGROUND: The majority of anal cancer is associated with human papillomavirus (HPV) infection, yet little is known about women's risk of acquisition of anal HPV infection. METHODS: Risk factors for the acquisition of anal HPV infection were examined in a longitudinal cohort study of 431 women, via repeated measurement of HPV DNA. RESULTS: Seventy percent of women were positive for anal HPV infection at one or more clinic visits from baseline through a follow-up period that averaged 1.3 years. The incidence of a high-risk (HR) infection was 19.5 (95% confidence interval [CI], 16.0-23.6) per 1000 woman-months. The most common incident HR HPV types were HPV-53, -52 and -16. The presence of an HR anal HPV infection at baseline increased the risk of an incident anal infection by 65%. Baseline HR cervical HPV infection also predicted the acquisition of an HR anal HPV infection (odds ratio, 1.81 [95% CI, 1.09-3.02]). Nonviral risk factors for acquisition of HR HPV infection included younger age, lower socioeconomic status, greater lifetime number of sexual partners, past use of hormones, and condom use. CONCLUSIONS: The results of this study suggest that women's risk of anal HPV infection is as common as their risk of cervical HPV infection. 相似文献
7.
Theory of the initial stages of electrochemical formation and growth of a single metal nanocluster on an indifferent nanoelectrode has been developed and analyzed. General theoretical time dependences of the current and nanocluster size have been presented for the case of diffusion controlled growth at potentio- and galvanostatic deposition, and cyclic voltammetry.The models of formation and growth of a single nanocluster on a nanoelectrode are presented for three basic electrochemical methods (cyclic voltammetry, potentiostatic and galvanostatic electrodeposition). 相似文献
8.
Butov Dmytro Feshchenko Yurii Myasoedov Valeriy Kuzhko Mykhailo Gumeniuk Mykola Gumeniuk Galyna Tkachenko Anton Nataliya Nekrasova Borysova Olena Butova Tetiana 《Wiener Medizinische Wochenschrift》2022,172(11-12):261-267
Wiener Medizinische Wochenschrift - This study assessed the effectiveness and diagnostic significance of hypertonic saline sputum induction for improving Mycobacterium tuberculosis (MTB) detection.... 相似文献
9.
An acoustic metamaterial superlattice is used for the spatial and spectral deconvolution of a broadband acoustic pulse into narrowband signals with different central frequencies. The operating frequency range is located on the second transmission band of the superlattice. The decomposition of the broadband pulse was achieved by the frequency-dependent refraction angle in the superlattice. The refracted angle within the acoustic superlattice was larger at higher operating frequency and verified by numerical calculated and experimental mapped sound fields between the layers. The spatial dispersion and the spectral decomposition of a broadband pulse were studied using lateral position-dependent frequency spectra experimentally with and without the superlattice structure along the direction of the propagating acoustic wave. In the absence of the superlattice, the acoustic propagation was influenced by the usual divergence of the beam, and the frequency spectrum was unaffected. The decomposition of the broadband wave in the superlattice’s presence was measured by two-dimensional spatial mapping of the acoustic spectra along the superlattice’s in-plane direction to characterize the propagation of the beam through the crystal. About 80% of the frequency range of the second transmission band showed exceptional performance on decomposition. 相似文献
10.
Olga A. Goncharova Andrey Yu. Luchkin Nina P. Andreeva Vadim E. Kasatkin Sergey. S. Vesely Nikolay N. Andreev Yurii I. Kuznetsov 《Materials》2022,15(4)
It has been shown by a set of corrosion, electrochemical and physical methods that a chamber corrosion inhibitor that consists of a mixture of octadecylamine (ODA) and benzotriazole (BTA) efficiently protects copper and brass from atmospheric corrosion and can be used for the temporary protection of metal items. The optimum temperatures of treatment with the ODA + BTA mixed inhibitor is 120 °C for brass and 100 °C for copper. One-hour treatment in ODA + BTA vapors at these temperatures results in the formation of nanosized adsorption films on the surface of these metals. These films stabilize the passive state and provide efficient temporary protection of metal items. The ODA + BTA inhibitor is superior to its components in terms of protective aftereffect. Our analysis of the mutual effect of BTA and ODA indicated that they show an antagonism of protective action on copper, but there is also a synergistic enhancement in the case of brass. Electrochemical impedance spectroscopy studies demonstrate that the inhibitors in question mainly act by using a blocking mechanism on copper and brass. Chamber treatment of the metals studied in vapors of the ODA + BTA mixture resulted in a noticeable hydrophobization of the copper surface and an insignificant effect on the brass surface. Chamber treatment of copper samples with artificially created polymodal roughness made it possible to obtain a superhydrophobic surface. 相似文献