全文获取类型
收费全文 | 90篇 |
免费 | 5篇 |
国内免费 | 1篇 |
专业分类
妇产科学 | 4篇 |
基础医学 | 8篇 |
临床医学 | 5篇 |
内科学 | 31篇 |
神经病学 | 10篇 |
特种医学 | 2篇 |
外科学 | 9篇 |
综合类 | 1篇 |
药学 | 15篇 |
中国医学 | 1篇 |
肿瘤学 | 10篇 |
出版年
2023年 | 1篇 |
2022年 | 11篇 |
2021年 | 3篇 |
2020年 | 2篇 |
2019年 | 4篇 |
2018年 | 2篇 |
2017年 | 2篇 |
2016年 | 2篇 |
2015年 | 4篇 |
2014年 | 6篇 |
2013年 | 3篇 |
2012年 | 10篇 |
2011年 | 4篇 |
2010年 | 4篇 |
2009年 | 2篇 |
2008年 | 5篇 |
2007年 | 5篇 |
2006年 | 4篇 |
2005年 | 2篇 |
2004年 | 4篇 |
2003年 | 4篇 |
2002年 | 4篇 |
1999年 | 1篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 3篇 |
1991年 | 1篇 |
排序方式: 共有96条查询结果,搜索用时 15 毫秒
1.
Lucie Sobolová Nina Skottová Rostislav Vecera Karel Urbánek 《Pharmacological research》2006,53(2):104-112
This study evaluated the influence of silymarin (SM) and polyphenolic fraction (PF) of silymarin on cholesterol absorption in rats fed on high cholesterol diet (HCD). HCD induced a remarkable increase in hepatic, plasma, VLDL and LDL cholesterol, a decrease in HDL cholesterol and an elevation in triacylglycerol (TAG) levels in plasma, VLDL and in the liver. SM and PF were administered as dietary supplements (1.0%) in HCD for 18 days. Intestinal cholesterol absorption was measured by dual-isotope plasma ratio method, which calculates percent of cholesterol absorption from the ratio of two labelled cholesterol doses, one given intragastrically (14C) and one intravenously (3H). Silymarin and PF significantly reduced cholesterol absorption in rats fed on HCD and caused significant decreases in plasma and VLDL cholesterol and content of cholesterol and TAG in the liver. The level of HDL cholesterol was significantly increased after silymarin, but not after administration of PF. The levels of TAG in plasma and VLDL were not affected by either silymarin or PF. These results suggest that the inhibition of cholesterol absorption caused by silymarin and its polyphenolic fraction could be a mechanism contributing to the positive changes in plasma cholesterol lipoprotein profile and in lipid content in liver. 相似文献
2.
Shamil D. Akhmedov M.D. Euvgenily V. Krivoschekov M.D. Mariana V. Pekarskaya M.D. Alexander L. Krylov M.D. Zhanna V. Vesnina M.D. Vladimir I. Chernov M.D. Alexander M. Chernyavskiy M.D. Yuriy Y. Vechersky M.D. Rostislav S. Karpov M.D. Edward A. Nechaev M.D. Vikenty V. Pekarski M.D. 《Journal of cardiac surgery》1995,10(5):573-579
Thirty-five cardiomyoplasty procedures were performed in five patients with dilated and 30 patients with ischemic cardiomyopathies. Russian-made cardiomyostimulators (CMS) were implanted in these patients. Twenty-one patients underwent a one-step procedure using a left thoracotomy for cardiomyoplasty, while in 14 patients, a two-step procedure that included a mid-line sternotomy was carried out. During the average follow-up period of 9 ± 2.1 months, studies were carried out that showed in survivors improved clinical functional status and decreased heart failure symptoms. Evidence of revascularization of the ischemic myocardium from the latissimus dorsi muscle (LDM) wrap was obtained by angiography and radioactive scintigraphy. In five patients, the CMS had to be removed due to complications, and in all these patients, their clinical functional status deteriorated following the cessation of cardiomyostimulation. 相似文献
3.
Ali K. Shargh Aude Picard Rostislav Hrubiak Dongzhou Zhang Russell J. Hemley Shanti Deemyad Niaz Abdolrahim Saveez Saffarian 《Proceedings of the National Academy of Sciences of the United States of America》2022,119(27)
Formation of vitreous ice during rapid compression of water at room temperature is important for biology and the study of biological systems. Here, we show that Raman spectra of rapidly compressed water at greater than 1 GPa at room temperature exhibits the signature of high-density amorphous ice, whereas the X-ray diffraction (XRD) pattern is dominated by crystalline ice VI. To resolve this apparent contradiction, we used molecular dynamics simulations to calculate full vibrational spectra and diffraction patterns of mixtures of vitreous ice and ice VI, including embedded interfaces between the two phases. We show quantitatively that Raman spectra, which probe the local polarizability with respect to atomic displacements, are dominated by the vitreous phase, whereas a small amount of the crystalline component is readily apparent by XRD. The results of our combined experimental and theoretical studies have implications for detecting vitreous phases of water, survival of biological systems under extreme conditions, and biological imaging. The results provide additional insight into the stable and metastable phases of H2O as a function of pressure and temperature, as well as of other materials undergoing pressure-induced amorphization and other metastable transitions.Life as we know it on Earth depends on water. However, water also poses a critical challenge to life when it freezes at atmospheric pressure and low temperatures. The crystallization of H2O to form hexagonal ice () under these conditions is accompanied by its well-known expansion, which has a dramatic impact on the structure and function of living cells. This crystallization of H2O disrupts biological membranes and intracellular organization in living organisms and also displaces and concentrates salts and nutrients in the space between crystals (1). Like many liquids, however, rapid cooling of H2O at ambient pressure to below its glass-transition temperature results in the formation of an amorphous phase known as low-density amorphous ice. Amorphous solid H2O provides a chance for biological functions to survive where life otherwise cannot exist. Low-density amorphous ice is not the only amorphous form of H2O. Ice Ih transforms to high-density amorphous (HDA) ice by application of ∼1 GPa of pressure at temperatures below 130 K (2, 3). In addition, a distinct, very-high-density amorphous state (vHDA) can form by isobaric heating and cooling of the HDA (4). low-density amorphous, high-density amorphous, and very-high-density amorphous state ice thus represent the three dominant, solid amorphous forms of H2O at low temperatures.Solid amorphous phases of H2O are broadly important in biology and biological applications. That amorphous H2O which can exist over a broad range of temperatures, from cryogenic conditions to room temperature, is particularly interesting in the context of biological systems. Managing ice crystals is vital for extremophiles to survive damaging effects of H2O crystallization. These organisms inhibit the growth of ice crystals and regulate the size and shape of the crystals using special antifreeze proteins (5, 6). Additionally, amorphous phases of H2O are important in preserving biological samples in cryotomography applications. In cryotomography, the amorphous H2O at low temperature is utilized routinely for sample preparation (7, 8), and significant efforts have been devoted to increase information obtained from cryotomography techniques. The low-temperature regime of amorphous H2O routinely accessed in cryotomography creates challenges for light microscopy due to freezing of index-matching medium and objectives, which result in lowering the resolution of light microscopy in these applications. Room-temperature amorphous phases of H2O are, therefore, advantageous for light microscopy applications and further development of techniques such as correlative light and electron microscopy (9–11).While formation of amorphous phases of H2O below 200 K has been reported in many studies (2, 3, 12–16), a particularly interesting result is the observation of the Raman signature of HDA ice during fast compression of water at room temperature and moderate pressures (17). On the other hand, independent X-ray diffraction (XRD) measurements of H2O on fast compression could not verify the formation of amorphous H2O above 200 K (18). Here, we report high-resolution micro-Raman and synchrotron XRD measurements conducted in parallel in rapidly compressed samples of water in diamond anvil cells (DACs). Our findings, that are supported by molecular dynamics simulations, shed light on the nature of the HDA ice at room temperature and reconciled conflicting previous reports. 相似文献
4.
Seth Iwan Chia-Min Lin Christopher Perreault Kallol Chakrabarty Cheng-Chien Chen Yogesh Vohra Rostislav Hrubiak Guoyin Shen Nenad Velisavljevic 《Materials》2022,15(9)
The high-entropy transition metal borides containing a random distribution of five or more constituent metallic elements offer novel opportunities in designing materials that show crystalline phase stability, high strength, and thermal oxidation resistance under extreme conditions. We present a comprehensive theoretical and experimental investigation of prototypical high-entropy boride (HEB) materials such as (Hf, Mo, Nb, Ta, Ti)B2 and (Hf, Mo, Nb, Ta, Zr)B2 under extreme environments of pressures and temperatures. The theoretical tools include modeling elastic properties by special quasi-random structures that predict a bulk modulus of 288 GPa and a shear modulus of 215 GPa at ambient conditions. HEB samples were synthesized under high pressures and high temperatures and studied to 9.5 GPa and 2273 K in a large-volume pressure cell. The thermal equation of state measurement yielded a bulk modulus of 276 GPa, in excellent agreement with theory. The measured compressive yield strength by radial X-ray diffraction technique in a diamond anvil cell was 28 GPa at a pressure of 65 GPa, which is a significant fraction of the shear modulus at high pressures. The high compressive strength and phase stability of this material under high pressures and high temperatures make it an ideal candidate for application as a structural material in nuclear and aerospace fields. 相似文献
5.
Ruth Simmons Igor Semenenko Maria Tolpina Rostislav Tereschenko Ludmila Kotlik Lyubov Zasyptka Gary Murphy Elaine Mckinney Andrew Copas Ruslan Malyuta Kholoud Porter 《AIDS and behavior》2014,18(2):411-418
The proportion of new HIV diagnoses between May and December 2009 across Odessa recently-infected was estimated using the BED-CEIA assay. Logistic regression models were used to explore factors associated with testing as recent. Of 1,313 newly-diagnosed individuals, 321 (24 %) were classified as recent. Recent infection was less likely among older adults [odds ratio (OR) = 0.70 per 10-year increase, 95 % CI 0.60–0.82]. Compared to men residing in Odessa city, women in rural Odessa and non-resident men were more likely to be recently-infected (OR 1.85, 1.26–2.71 and 2.83, 1.15–6.97, respectively). Reason for test was not associated with recent infection. In sensitivity analysis, after excluding individuals tested due to clinical indications, the proportion recently-infected and the association with age remained virtually unchanged. Our findings suggest a high risk of onward transmission, particularly in younger age groups. These findings highlight the need for tailored prevention strategies and ongoing RITA testing to monitor and evaluate effectiveness of prevention programmes. 相似文献
6.
Richard Milkovič Peter Telekes Pavel Nedbal Vladimír Hraboš Petra Antonová Rostislav Polášek 《Cor et vasa》2012,54(2):e104-e107
Tumors of the heart are not very common in the population. The clinical symptoms are non-specific and depend on the size and localization of the tumor. Our case report describes a 56 year-old male, who was referred to our facility for selective coronary angiography with a clinical picture of ST segment elevation myocardial infarction. However, the cause of the ECG changes was advanced lung carcinoma growing into the myocardium. 相似文献
7.
Petra Faltejskova Andrej Besse Sabina Sevcikova Lenka Kubiczkova Marek Svoboda Jan Smarda Igor Kiss Rostislav Vyzula Ondrej Slaby 《International journal of colorectal disease》2012,27(11):1401-1408
Purpose
MicroRNA-21 (miR-21) is one of the miRNAs that are frequently and highly overexpressed in tumor tissue of colorectal cancer (CRC) patients; however, only a little is known about its functional role in CRC.Methods
We examined the expression level of miR-21 in 44 paired samples of tumoral and non-tumoral colon tissues diagnosed for CRC using TaqMan real-time PCR method. Furthermore, we used miR-21 inhibitor (anti-miR-21) to transient knockdown of miR-21 in DLD-1 colon cancer cells and examined the effects of miR-21 silencing on viability, apoptosis, chemosensitivity, cell cycle, and migration of DLD1 cells.Results
The expression levels of miR-21 were significantly increased in CRC tumor tissue (P?<?0.0001). Significant differences in miR-21 levels were observed also between CRC tissues of patients with CRC in different clinical stages: I vs. II (P?=?0.033) and I vs. IV (P?=?0.021). Kaplan–Meier analysis proved that the miR-21 expression levels are correlated to shorter overall survival of CRC patients (P?=?0.0341). MiR-21 silencing in DLD1 cell line had no effect on the cell viability; however, when combined with chemotherapeutics (5-FU, L-OHP, and SN38), it contributed to the decrease of cell viability. Suppression of miR-21 decreased cell migration ability of DLD-1 cells by nearly 30?% (P?=?0.016).Conclusion
We have confirmed the overexpression of miR-21 in CRC samples and its correlation with advanced disease and shorter overall survival. These findings could be described in part by the fact that CRC cells with increased expression of miR-21 have higher migration ability. 相似文献8.
Hezova R Kovarikova A Bienertova-Vasku J Sachlova M Redova M Vasku A Svoboda M Radova L Kiss I Vyzula R Slaby O 《World journal of gastroenterology : WJG》2012,18(22):2827-2831
AIM: To investigate whether selected single nucleotide polymorphisms (SNPs) in miR-196a2, miR-27a and miR-146a genes are associated with sporadic colorectal cancer (CRC).METHODS: In order to investigate the effect of these SNPs in CRC, we performed a case-control study of 197 cases of sporadic CRC and 212 cancer-free controls originating from the Central-European Caucasian population using TaqMan Real-Time polymerase chain reaction and allelic discrimination analysis.RESULTS: The genotype and allele frequencies of SNPs were compared between the cases and the controls. None of the performed analysis showed any statistically significant results.CONCLUSION: Our data suggest a lack of association between rs11614913, rs895819 and rs2910164 and colorectal cancer risk in the Central-European Caucasian population, a population with an extremely high incidence of sporadic colorectal cancer. 相似文献
9.
Lisa Adelfinger Rostislav Turecek Klara Ivankova Anders A. Jensen Stephen J. Moss Martin Gassmann Bernhard Bettler 《Biochemical pharmacology》2014
GABAB receptors assemble from GABAB1 and GABAB2 subunits. GABAB2 additionally associates with auxiliary KCTD subunits (named after their K+ channel tetramerization-domain). GABAB receptors couple to heterotrimeric G-proteins and activate inwardly-rectifying K+ channels through the βγ subunits released from the G-protein. Receptor-activated K+ currents desensitize in the sustained presence of agonist to avoid excessive effects on neuronal activity. Desensitization of K+ currents integrates distinct mechanistic underpinnings. GABAB receptor activity reduces protein kinase-A activity, which reduces phosphorylation of serine-892 in GABAB2 and promotes receptor degradation. This form of desensitization operates on the time scale of several minutes to hours. A faster form of desensitization is induced by the auxiliary subunit KCTD12, which interferes with channel activation by binding to the G-protein βγ subunits. Here we show that the two mechanisms of desensitization influence each other. Serine-892 phosphorylation in heterologous cells rearranges KCTD12 at the receptor and slows KCTD12-induced desensitization. Likewise, protein kinase-A activation in hippocampal neurons slows fast desensitization of GABAB receptor-activated K+ currents while protein kinase-A inhibition accelerates fast desensitization. Protein kinase-A fails to regulate fast desensitization in KCTD12 knock-out mice or knock-in mice with a serine-892 to alanine mutation, thus demonstrating that serine-892 phosphorylation regulates KCTD12-induced desensitization in vivo. Fast current desensitization is accelerated in hippocampal neurons carrying the serine-892 to alanine mutation, showing that tonic serine-892 phosphorylation normally limits KCTD12-induced desensitization. Tonic serine-892 phosphorylation is in turn promoted by assembly of receptors with KCTD12. This cross-regulation of serine-892 phosphorylation and KCTD12 activity sharpens the response during repeated receptor activation. 相似文献
10.