首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   369篇
  免费   19篇
  国内免费   4篇
耳鼻咽喉   9篇
儿科学   5篇
妇产科学   7篇
基础医学   38篇
口腔科学   7篇
临床医学   34篇
内科学   31篇
皮肤病学   3篇
神经病学   32篇
特种医学   67篇
外科学   46篇
综合类   3篇
预防医学   31篇
眼科学   2篇
药学   47篇
中国医学   2篇
肿瘤学   28篇
  2023年   3篇
  2022年   4篇
  2021年   5篇
  2020年   4篇
  2019年   8篇
  2018年   15篇
  2017年   4篇
  2016年   6篇
  2015年   9篇
  2014年   6篇
  2013年   23篇
  2012年   25篇
  2011年   48篇
  2010年   26篇
  2009年   16篇
  2008年   43篇
  2007年   38篇
  2006年   34篇
  2005年   19篇
  2004年   21篇
  2003年   14篇
  2002年   11篇
  2001年   1篇
  1999年   2篇
  1998年   3篇
  1996年   1篇
  1995年   1篇
  1975年   1篇
  1968年   1篇
排序方式: 共有392条查询结果,搜索用时 15 毫秒
91.
Epidemiological and experimental data point to involvement of oxygen derived radicals in the pathogenesis of gynecological disorders, as well as in cancer development. The objective of the present study was to examine changes in activities and levels of copper/zinc superoxide dismutase (CuZnSOD) and lipid hydroperoxides (LOOH) in blood and endometrial tissue of patients diagnosed with uterine myoma, endometrial polypus, hyperplasia simplex, hyperplasia complex and adenocarcinoma endometrii. The results of our study have shown decreased SOD activities and unchanged SOD protein level in blood of all examined patients in comparison to healthy subjects. Decrease of both SOD activity and level was found in endometrium of patients with hyperplasia simplex, hyperplasia complex and adenocarcinoma in comparison to women with polypus or myoma. LOOH level was elevated in both tissues of patients with hyperplasia or adenocarcinoma in comparison to healthy subjects or patients with benign diagnosis. Our findings suggest that the decrease in SOD activity and level, as well as the increase in LOOH level, in patients with gynecological disorders, render these patients more susceptible to oxidative damage caused by reactive oxygen species (ROS). An imbalance in ROS formation and SOD level may be important in the pathogenesis and/or perpetuation of tissue damage in gynecological patients. Since evidence suggests that SOD may be a therapy target for cancer treatment, our findings provide a basis for further research and options for clinical applications.  相似文献   
92.
93.
The antiproliferative and cytotoxic potential of the natural anthracycline aloin from Aloe vera was tested on human uterine carcinoma HeLaS3 cells. Aloin showed a pronounced antiproliferative effect at physiological concentration (IC50 = 97 microM), caused cell cycle arrest in the S phase and markedly increased HeLaS3 cell apoptosis (to 24%). In the concentration range of 20-100 microM, its action was accompanied by remarkable changes in the activity of almost all antioxidant enzymes: MnSOD activity was increased many fold, while CuZnSOD and iNOS activities were inhibited. Moreover, inhibition of CuZnSOD was shown to occur by direct aloin interaction with the enzyme. As catalase activity was not changed, it is suggested that such conditions were responsible for antiproliferative and cytotoxic effects owing to accumulation of H2O2. Aloin alone was a more potent proapoptotic agent than a 2 Gy fractional dose of ionizing radiation or a combination of the two. Compared to other currently used therapeutics, aloin, due to its less undesirable side effects and antimetastatic potential, may prove to be the agent of choice on which clinical protocols for the treatment of human cervical carcinoma should rely in future.  相似文献   
94.
AIM: To estimate the characteristics of Color Doppler findings and the results of hepatic radionuclide angiography (HRA) in secondary Hodgkin's hepatic lymphoma.
METHODS: The research included patients with a diagnosis of Hodgkin's lymphoma with metastatic focal lesions in the liver and controls. Morphologic characteristics of focal liver lesions and hemodynamic parameters were examined by pulsed and Color Doppler in the portal, hepatic and splenic veins were examined. Hepatic perfusion index (HPI) estimated by HRA was calculated. was observed. Lesions were mostly hypoechoic and mixed, solitary or multiple. Some of the patients presented with dilated splenic veins and hepatofugal blood flow. A pulse wave was registered in the centre and at the margins of lymphoma. The average velocity of the pulse wave was higher at the margins (P 〉 0.05). A continuous venous wave was found only at the margins of lymphoma. There was no linear correlation between lymphoma size and velocity of pulse and continuous wave (r = 390, P 〈 0.01). HPI was significantly lower in patients with lymphomas than in controls (P 〈 0.05), pointing out increased arterial perfusion in comparison to portal perfusion.
CONCLUSION: Color Doppler ultrasonography is a sensitive method for the detection of neovascularization in Hodgkin's hepatic lymphoma and estimation of its intensity. Hepatic radionuclide angiography can additionally help in the assesment of vascularisation of liver lesions.  相似文献   
95.
The fluorescence properties of anticancer drugs (ACDs), including steady-state native fluorescence, time-resolved fluorescence, fluorescence polarization, excimer and exciplex emission, laser-induced fluorescence (LIF) with one- or two-photon excitation are reviewed, as well as the use of fluorogenic labels and fluorescent probes for the non-fluorescent ACDs. The interest of monitoring the fluorescence spectral changes to study the interactions of ACDs with biomolecules, such as DNA, proteins, vesicles, and the formation of complexes is discussed. The fluorescence methodologies used for ACDs studies, including fluorescence with two-photon excitation, liquid chromatography and capillary electrophoresis with fluorescence and laser-induced fluorescence (LIF) detection, and fluorescence microscopy, are also surveyed. Analytical and bioanalytical applications of fluorescence, indicating good selectivity and very low limits of detection at the nanomolar and picomolar level for most ACDs, are described. Biomedical and clinical applications of the fluorescence methods, mostly oriented towards the evaluation of the cytoxicity and anti-tumor potential of ACDs in single cells as well as in biological fluids, including blood, serum, plasma, cerebrospinal fluid, urine and feces, are also discussed in detail. This review is based on selected literature published in the last decade (1994-2003).  相似文献   
96.
An emerging class of natural surfactants, named alkylpolyglucosides, which can form both, the thermotropic and the lyotropic liquid crystalline phases, were focused. The aim of the study was to integrate some physicochemical properties (characterised through the polarization and transmission electron microscopy, wide-angle X-ray diffraction, thermal analysis and rheology) of the three formulations based on cetearyl glucoside and cetearyl alcohol, with the in vitro (the artificial skin constructs) and in vivo bioavailability of hydrocortisone (HC), in comparison with a standard pharmacopoeial vehicle. The parameters measured in vivo were erythema index (an instrumental human skin blanching assay), transepidermal water loss (TEWL) and stratum corneum hydration. A complex colloidal structure of lamellar liquid crystalline and lamellar gel crystalline type was deduced for sugar surfactant-based vehicles. In dependence on surfactant/water/oil ratio, several thermodinamically variable fractions of water were predicted. Rheological profile of the vehicle appeared to influence the in vitro profile of permeation. A surplus of total amount of drug permeated in vitro from the alkylpolyglucoside-based vehicles coincided with the more pronounced increase of TEWL and less marked blanching action of HC from the selected alkylpolyglucoside-based vehicle tested in vivo, related to the pharmacopoeial one. These findings imply an enhanced delivery of HC from this vehicle and its putative penetration enhancing effect, probably dependent on specific distribution of the vehicle's inherent water.  相似文献   
97.
Early diagnosis of the central nervous system (CNS) infections is a precondition of their successful treatment. However, the essential standard examination of the cerebrospinal fluid (CSF) is sometimes neither specific enough to define their basic nature, nor sufficient to differentiate them from processes of non-infectious origin. Supposing that the released surface molecules of activated immunocompetent cells could better define the character of inflammatory reaction, the levels of soluble CD4 antigens (sCD4) were determined with enzyme-immunosorbent test in the CSF of the patients with various CNS diseases. In contrast to cerebrovascular insults, toxic-metabolic, and other conditions in control group, detectable sCD4 concentrations in acute encephalitis (24 +/- 11 U/ml) were verified at the beginning of the disease, being also present in cytologically diagnosed normal CSF findings. They were significantly higher (p<0.05) compared to acute serous meningitis (13.5 +/- 8 U/ml), while in purulent meningitis they were measurable only after the disease progression--in correlation with the disturbed brain system function. The obtained results suggested the significance of CD4 antigen levels in CSF as a sensitive and specific marker of lymphocytic infiltration of the brain parenchyma, the measurement of which could contribute to early identification of the CNS infections, better understanding of their pathogenesis, and the assessment of the actual level of the destruction of neurons.  相似文献   
98.
Chronic lymphocytic leukemia (CLL) is a neoplastic disease characterized by the accumulation of morphologically mature monoclonal CD 5+ B cells in the early phase (G0/G1) of the cell cycle. It is considered that the accumulation of neoplastically transformed lymphocytes B (CLL cells) is primarily the consequence of the disturbance, i.e., blockade of these cells' apoptosis process. Apoptosis is the specific process of programmed cell death regulated by numerous extracellular and intracellular mechanisms. The Bcl-2 proteins are well-known modulators of this process. Some of these proteins (such as Bcl-2, and Bcl-XI) are anti-apoptotic, while others (such as Bad or Bax) are pro-apoptotic. Our study included the analysis of 20 peripheral blood specimens from 20 patients with CLL, and 20 peripheral blood specimens of healthy persons who represented the control group. Using Western blotting analysis, we quantitatively examined the protein expression of Bcl-2 family (Bcl-2, Bax, Bad, and Bcl-XI). The level of Bcl-2 (p = 3.68 x 10(-10)), Bax (p = 0.019), and Bad (p = 0.073) proteins expression was significantly increased in all the analyzed peripheral blood samples of patients, while the level of Bcl-XI protein (p = 0.75) did not significantly differ in peripheral blood samples of patients, compared to the controls. The results of this study showed that the increased level of expression of Bcl-2, Bax, and Bad protein represented the most striking feature of CLL cells. Moreover, the variations in the expression of only one protein of the Bcl-2 family could not represent the prognostic parameter in the treatment of this disease.  相似文献   
99.
BACKGROUND: High-dose chemotherapy followed by hematopoietic stem cell support can be used as a first-line treatment in patients with germ-cell tumor (GCT) with poor prognosis. Long-term survival rate is attained in 50% of these patients. The aim of this paper was to present the experience at the Department of Hematology, Military Medical Academy, with high-dose cytostatic therapy as first-line chemotherapy in GCT patients with poor prognosis. METHODS: Between 1997 and 2003, five patients with high-risk germ-cell tumors were treated with high-dosage chemotherapy followed by an autologous stem cell transplantation. All the patients were with non-seminomatous germ-cell tumors with mixed histology, and one was with extragonadal retroperitoneal germ-cell tumor. RESULTS: The follow-up period ranged from 8 to 33 months. Three patients achieved complete remision, two patients only partial remision, and one was not followed-up. One patient was with residual tumor resection, using retroperitoneal lymphadenectomy, after autologous stem cell transplantation. All the patients were treated according to standard protocols. CONCLUSION: Early high-dose chemotherapy associated with hematopoietic stem cell support as a first-line treatment in the patients with germ-cell tumor with a poor prognosis, represented an efficient treatment modality.  相似文献   
100.
Amifostine protection against doxorubicin cardiotoxicity in rats   总被引:3,自引:0,他引:3  
Aminothiol amifostine (AMI) protects against toxic effects of both ionizing radiation and numerous anticancer drugs. The aim of this study was to investigate the potential protective effects of AMI against doxorubicin (DOX)-induced cardiotoxicity in rats. Male Wistar rats were treated with AMI (75 mg/kg i.p.) and/or DOX (1.25 mg/kg i.p.), 4 times per week, for 4 weeks. Mortality, general condition and body weight of the animals were observed during the whole treatment, and for a further 4 weeks, until the end of experiment. Evaluation of cardioprotective efficacy of AMI was performed by analyzing the electrocardiographic parameters and response to the pro-arrhythmic agent aconitine, as well as activity registration of the in situ rat heart preparations. Necropsy was also performed at the end of the experiment, and heart excision, weight and macroscopic examination were done before histological evaluation. Doxorubicin caused rat heart disturbances manifested by prominent electrocardiographic changes (Salpha-T prolongation and T-wave flattening), significantly enhanced response to aconitine, decrease of the heart rate and contractility, as well as histopathologically verified myocardial lesions. The heart changes were accompanied by 40% mortality rate, significant decline in body mass and severe effusion intensity score in 66.6% of the animals. Application of AMI before each dose of DOX significantly reduced or completely prevented its toxic effects. Therefore, since AMI had very good protective effects against a high dose of DOX given as a multiple, low, unitary dose regimen, not only on the heart but on the whole rat as well, it could be recommended for further investigation in this potentially new indication for clinical application.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号