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91.
M. V. Sil’nikov A. I. Mikhailin A. V. Petrov Yu. I. Meshcheryakov V. A. Ermolaev N. S. Kochetova S. M. Usherenko 《Technical Physics Letters》2000,26(8):734-736
Effect of the shock-wave treatment on the dynamic strength of a 38KhN3MFA grade steel was studied in two different regimes—shock wave propagation and superdeep incorporation of ultrafine powder. In the first case, an increase in the dynamic strength is observed, related primarily to a decrease in the proportion of hard and brittle domains in the material as a result of the shock-wave action. The superdeep ultrafine powder incorporation produced no significant effects on the dynamic properties of steel. 相似文献
92.
Joyce Chai Jimmy Lin Wlodek Zadrozny Yiming Ye Margo Stys-Budzikowska Veronika Horvath Nanda Kambhatla Catherine Wolf 《International Journal of Speech Technology》2001,4(3-4):285-295
This paper describes the evaluation of a natural language dialog-based navigation system (HappyAssistant) that helps users access e-commerce sites to find relevant information about products and services. The prototype system leverages technologies in natural language processing and human-computer interaction to create a faster and more intuitive way of interacting with websites, especially for less experienced users. The result of a comparative study shows that users prefer the natural language-enabled navigation two to one over the menu driven navigation. In addition, the study confirmed the efficiency of using natural language dialog in terms of the number of clicks and the amount of time required to obtain the relevant information. In the case study, as compared to the menu driven system, the average number of clicks used in the natural language system was reduced by 63.2% and the average time was reduced by 33.3%. 相似文献
93.
94.
Veronika A. Myasoedova Tatyana V. Kirichenko Alexandra A. Melnichenko Varvara A. Orekhova Alessio Ravani Paolo Poggio Igor A. Sobenin Yuri V. Bobryshev Alexander N. Orekhov 《International journal of molecular sciences》2016,17(8)
The risk of cardiovascular disease and atherosclerosis progression is significantly increased after menopause, probably due to the decrease of estrogen levels. The use of hormone replacement therapy (HRT) for prevention of cardiovascular disease in older postmenopausal failed to meet expectations. Phytoestrogens may induce some improvements in climacteric symptoms, but their effect on the progression of atherosclerosis remains unclear. The reduction of cholesterol accumulation at the cellular level should lead to inhibition of the atherosclerotic process in the arterial wall. The inhibition of intracellular lipid deposition with isoflavonoids was suggested as the effective way for the prevention of plaque formation in the arterial wall. The aim of this double-blind, placebo-controlled clinical study was to investigate the effect of an isoflavonoid-rich herbal preparation on atherosclerosis progression in postmenopausal women free of overt cardiovascular disease. One hundred fifty-seven healthy postmenopausal women (age 65 ± 6) were randomized to a 500 mg isoflavonoid-rich herbal preparation containing tannins from grape seeds, green tea leaves, hop cone powder, and garlic powder, or placebo. Conventional cardiovascular risk factors and intima-media thickness of common carotid arteries (cIMT) were evaluated at the baseline and after 12 months of treatment. After 12-months follow-up, total cholesterol decreased by 6.3% in isoflavonoid-rich herbal preparation recipients (p = 0.011) and by 5.2% in placebo recipients (p = 0.020); low density lipoprotein (LDL) cholesterol decreased by 7.6% in isoflavonoid-rich herbal preparation recipients (p = 0.040) and by 5.2% in placebo recipients (non-significant, NS); high density lipoprotein (HDL) cholesterol decreased by 3.4% in isoflavonoid-rich herbal preparation recipients (NS) and by 4.5% in placebo recipients (p = 0.038); triglycerides decreased by 6.0% in isoflavonoid-rich herbal preparation recipients (NS) and by 7.1% in placebo recipients (NS). The differences between lipid changes in the isoflavonoid-rich herbal preparation and placebo recipients did not reach statistical significance (p > 0.05). Nevertheless, the mean cIMT progression was significantly lower in isoflavonoid-rich herbal preparation recipients as compared to the placebo group (6 μm, or <1%, versus 100 μm, or 13%; p < 0.001 for the difference). The growth of existing atherosclerotic plaques in isoflavonoid-rich herbal preparation recipients was inhibited by 1.5-fold (27% versus 41% in the placebo group). The obtained results demonstrate that the use of isoflavonoid-rich herbal preparation in postmenopausal women may suppress the formation of new atherosclerotic lesions and reduce the progression of existing ones, thus promising new drug for anti-atherosclerotic therapy. Nevertheless, further studies are required to confirm these findings. 相似文献
95.
Jan Kotl Michal Bua Veronika Urbanov Pavlína ez
ov Jindich Chmela Helena Langhansov Daniel Sojka Michael Mare Michail Kotsyfakis 《International journal of molecular sciences》2021,22(10)
The hard tick Ixodes ricinus is a vector of Lyme disease and tick-borne encephalitis. Host blood protein digestion, essential for tick development and reproduction, occurs in tick midgut digestive cells driven by cathepsin proteases. Little is known about the regulation of the digestive proteolytic machinery of I. ricinus. Here we characterize a novel cystatin-type protease inhibitor, mialostatin, from the I. ricinus midgut. Blood feeding rapidly induced mialostatin expression in the gut, which continued after tick detachment. Recombinant mialostatin inhibited a number of I. ricinus digestive cysteine cathepsins, with the greatest potency observed against cathepsin L isoforms, with which it co-localized in midgut digestive cells. The crystal structure of mialostatin was determined at 1.55 Å to explain its unique inhibitory specificity. Finally, mialostatin effectively blocked in vitro proteolysis of blood proteins by midgut cysteine cathepsins. Mialostatin is likely to be involved in the regulation of gut-associated proteolytic pathways, making midgut cystatins promising targets for tick control strategies. 相似文献
96.
97.
98.
Two tetraplex real-time PCR for the detection and quantification of DNA from eight allergens in food 总被引:2,自引:0,他引:2
René Köppel Veronika Dvorak Franziska Zimmerli Alda Breitenmoser Albert Eugster Hans-Ulrich Waiblinger 《European Food Research and Technology》2010,230(3):367-374
According to the EU and Swiss legislation, food has to be labelled for allergens to enable allergic consumers to avoid such
food and its products. To provide efficient and reliable methods, two novel quantitative multiplex real-time polymerase chain
reaction systems were developed and validated. They simultaneously determine DNA of peanut, hazelnut, celery, soy, egg, milk,
almond and sesame, respectively. The tests exhibit good specificity and sensitivity in the range of 0.01%. Due to low DNA
amounts, lower sensitivities for egg and milk were obtained. First comparisons of ELISA results with PCR results suggest a
qualitative accordance, but a low correlation of quantitative results. 相似文献
99.
Miloš Janeček Josef Stráský Jakub Čížek Petr Harcuba Kristína Václavová Veronika V. Polyakova Irina P. Semenova 《Metallurgical and Materials Transactions A》2014,45(1):7-15
Ultrafine-grained biocompatible Ti-6Al-7Nb alloy was produced by high pressure torsion (HPT). Lattice defects—vacancies and dislocations—investigated by positron annihilation spectroscopy, observations by scanning electron microscopy, and microhardness evaluation are linked to the strain imposed by different numbers of HPT revolutions and to the distance from the specimen center. Positron annihilation spectroscopy showed significant increase of dislocation density and concentration of vacancy clusters after ½ of the HPT revolution. Microhardness increases by 20 pct with increasing strain, but it is heterogenous due to duplex microstructure. The heterogeneity of the microhardness increases with increasing strain, suggesting that a heavily deformed and fragmented α + β lamellar microstructure is more hardened than primary alpha grains. The defect structure is homogenous after ½ HPT revolution, while the microhardness becomes homogenous after 3 HPT revolutions only. 相似文献
100.
Jernej Zupanc Damjana Drobne Barbara Drasler Janez Valant Ales Iglic Veronika Kralj-Iglic Darko Makovec Michael Rappolt Barbara Sartori Ksenija Kogej 《Carbon》2012,50(3):1170-1178
There are some molecular dynamic simulations but a paucity of experimental evidence of the effects of C-60 fullerene on lipid bilayers. The aim of this study is to assess the potential for disruption of the lipid bilayer by C-60 suspended in water. We selected a C-60 suspension that has previously been shown to provoke cell membrane destabilisation in vivo. Electromobility measurements show significant negative surface charge on the C-60 nanoparticles suspended in a glucose solution and a zeta potential of ?26 mV. The prevalent C-60 clusters have hydrodynamic radii of approximately 2 nm. Phase contrast microscopy and computer aided image analysis results show that C-60 causes shape transformations and rupture of unilamellar phospholipid vesicles, indicative of changes in their average mean curvature. Small-angle X-ray scattering reveals that C-60 provokes disruptions of external membranes of multilamellar vesicles only after freeze and thaw cycles. Here, the liposomes undergo breakage and annealing steps which increase the probability for fullerenes to insert into the MLVs. Our experimental findings confirm the potential of C-60 to reconstruct lipids in biological membranes. This research enhances our understanding of the impact of engineered nanoparticles on cell membranes. 相似文献