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排序方式: 共有1423条查询结果,搜索用时 15 毫秒
51.
Jacklyn Cho BS Brittany Toffey MD Ariel F. Silva NP Ariel Shalev MD Monika M. Safford MD Erica Phillips MD MS Ann Lee BS Faith Wiggins BS MS Elissa Kozlov PhD Emma K. Tsui PhD MPH Nicola Dell PhD Ariel C. Avgar PhD Susan J. Andreae PhD MPH Madeline R. Sterling MD MPH MS 《Health services research》2023,58(3):697-704
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Ildar Salakhov Elena Tkacheva Valeriy Kozlov Dmitriy Galanin Anas Sakhabutdinov 《RSC advances》2021,11(34):20916
The regularities of ethylene–propylene copolymerisation over a vanadium oxytrichloride (VOCl3)–ethylaluminium sesquichloride (EASC) catalytic system in the presence of hexachloro-p-xylene (HCPX), tert-butyl chloride, trichlorotoluene, hexachlorocyclopentadiene, and trichloroacetate were studied. The main kinetic regularities of ethylene–propylene copolymerisation when using HCPX were determined and the kinetic parameters of the process were obtained. It was shown that hexachloro-p-xylene is the most efficient promoter of polymerisation that increases activity of the “vanadium” catalyst severalfold and enhances propylene reactivity in its copolymerisation with ethylene. A number of molecular characteristics and physicochemical parameters were determined for the synthesised samples of ethylene–propylene copolymers. The resulting copolymers have a higher molecular weight and a broad molecular weight distribution and are richer in propylene monomers compared to the copolymers synthesised in the catalytic system without HCPX. Modification of the “vanadium” catalyst yields the copolymer with a more homogeneous structure. Assumptions were made about the mechanism of action of the promoter under study in the VOCl3–EASC catalytic system.Hexachloro-p-xylene was found to be an effective promoter of olefin copolymerisation in the presence of vanadium catalyst, which increases the activity severalfold, enhances propylene incorporation in the copolymer, and results in a more homogeneous polymer. 相似文献
55.
The present study compared intake of sweet (saccharin), bitter (quinine), and neutral (water) tastants available either in the context of suckling behavior through a surrogate nipple or independent adultlike feeding through an intraoral cheek cannula in 3-hr-old newborn rats lacking any suckling experience and 24-hr-old rats with regular experience with the dam's nipple. The new technique of online monitoring of fluid flow was applied for assessment of the temporal patterns of ingestion. Newborn and 1-day-old rats tested in the context of suckling behavior showed extremely low intake of quinine, moderate intake of water, and high intake of saccharin. In the same way, they demonstrated low intake of quinine and high intake of saccharin in the context of independent feeding, but intake of water was also high and comparable to that of saccharin. Suckling rats attained higher efficacy of fluid extraction from nipple than pups drinking from cannula. The differential responsiveness to quinine, saccharin, and water in suckling rats was also manifested through attachment behavior, with pups spending less time on the nipple providing quinine and more time on the nipple with saccharin than on the nipple providing water. These results suggest that neonates show taste differentiation as early as 3 hr after birth, and that this taste differentiation is more pronounced in the context of suckling behavior than in the context of adultlike, independent ingestion. 相似文献
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Biomedical Engineering - 相似文献
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Irving F. Hoffman Carl A. Latkin Polina V. Kukhareva Sergey V. Malov Julia V. Batluk Alla V. Shaboltas Roman V. Skochilov Nicolay V. Sokolov Sergei V. Verevochkin Michael G. Hudgens Andrei P. Kozlov 《AIDS and behavior》2013,17(7):2510-2520
We evaluated the efficacy of a peer-educator network intervention as a strategy to reduce HIV acquisition among injection drug users (IDUs) and their drug and/or sexual networks. A randomized controlled trial was conducted in St. Petersburg, Russia among IDU index participants and their risk network participants. Network units were randomized to the control or experimental intervention. Only the experimental index participants received training sessions to communicate risk reduction techniques to their network members. Analysis includes 76 index and 84 network participants who were HIV uninfected. The main outcome measure was HIV sero-conversion. The incidence rates in the control and experimental groups were 19.57 (95 % CI 10.74–35.65) and 7.76 (95 % CI 3.51–17.19) cases per 100 p/y, respectively. The IRR was 0.41 (95 % CI 0.15–1.08) without a statistically significant difference between the two groups (log rank test statistic X2 = 2.73, permutation p value = 0.16). Retention rate was 67 % with a third of the loss due to incarceration or death. The results show a promising trend that this strategy would be successful in reducing the acquisition of HIV among IDUs. 相似文献
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A. Ya. Goncharova A. S. Kamrukov A. B. Kirpichenkov N. P. Kozlov N. N. Kutina V. A. Sarychev A. F. Seliverstov 《Pharmaceutical Chemistry Journal》2008,42(10):596-598
A new oxidative process for the destruction of organic proteinaceous compounds in aqueous solutions, based on the combined
use of high-intensity pulsed continuous-spectrum radiation and hydrogen peroxide, is proposed and tested experimentally. The
radiation source was a high-power pulsed xenon lamp. Studies using an aqueous hemoglobin solution as an example demonstrated
the efficient photo-oxidative destruction of a protein, accompanied by significant decreases in chemical oxygen consumption
and dry residue. This process might be used in the development of new techniques for cleansing effluents from contemporary
industrial drugs and biochemicals production facilities.
Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 42, No. 10, pp. 46–48, October, 2008. 相似文献