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   439篇
  免费   15篇
  国内免费   2篇
儿科学   14篇
妇产科学   8篇
基础医学   82篇
口腔科学   32篇
临床医学   35篇
内科学   69篇
皮肤病学   3篇
神经病学   39篇
特种医学   11篇
外科学   63篇
综合类   8篇
预防医学   13篇
眼科学   2篇
药学   44篇
中国医学   1篇
肿瘤学   32篇
  2021年   2篇
  2020年   3篇
  2019年   4篇
  2017年   2篇
  2016年   2篇
  2015年   4篇
  2014年   6篇
  2013年   10篇
  2012年   16篇
  2011年   18篇
  2010年   10篇
  2009年   13篇
  2008年   9篇
  2007年   13篇
  2006年   10篇
  2005年   8篇
  2004年   13篇
  2003年   14篇
  2002年   15篇
  2001年   14篇
  2000年   20篇
  1999年   15篇
  1998年   19篇
  1997年   22篇
  1996年   7篇
  1995年   7篇
  1993年   8篇
  1992年   13篇
  1991年   15篇
  1990年   8篇
  1989年   18篇
  1988年   11篇
  1987年   20篇
  1986年   9篇
  1985年   5篇
  1984年   9篇
  1983年   7篇
  1981年   3篇
  1980年   3篇
  1979年   7篇
  1978年   9篇
  1977年   2篇
  1976年   5篇
  1972年   6篇
  1971年   3篇
  1969年   3篇
  1968年   4篇
  1967年   3篇
  1966年   2篇
  1965年   1篇
排序方式: 共有456条查询结果,搜索用时 15 毫秒
31.
目的探讨重型颅脑损伤开颅术中急性脑膨出原因及防治。方法对术中出现急性脑膨出的46例病人进行回顾性分析。结果导致脑膨出的主要原因有迟发性颅内血肿、急性弥漫性脑肿胀、低血压、低血氧及较大回流静脉的损伤。结论术中出现急性脑膨出的病因是多方面的,针对不同的病因采取相应的措施,可以减轻脑组织的损害,降低病死率。  相似文献   
32.
Objective : To determine the approach to identifying neonatal hypoglycaemia and the definition of neonatal hypoglycaemia used by neonatal paediatricians in Australian Level 3 neonatal intensive care units (NICU).
Methodology : A questionnaire was sent to the 101 neonatal paediatricians in the 22 Level 3 NICU in Australia asking their method of screening for, and definition of, neonatal hypoglycaemia.
Results : Responses were received from 70 neonatal paediatricians, including all 22 directors. A bedside glucose meter is used in 19 of 22 NICU to screen for hypoglycaemia, whilst one NICU uses a glucose analyzer and another NICU uses a visual colour comparison method. One NICU does not screen, but has blood glucose measured in a satellite laboratory. If the screening method suggests hypoglycaemia, 62 of 63 neonatal paediatricians proceed to blood glucose determination in a laboratory, mostly using plasma samples. Based on the laboratory measurement, the definition of neonatal hypoglycaemia ranged from <1.1 to 3.0 mmol/L.
Conclusions : The majority of neonatal paediatricians in Australian NICU screen for neonatal hypoglycaemia using a bedside glucose meter. There is a wide range in the definition of neonatal hypoglycaemia from <1.1 to 3.0mmol/L.  相似文献   
33.
A rhodacyanine dye called MKT-077 has shown a highly selective toxicity toward several distinct human malignant cell lines, including bladder carcinoma EJ, and has been subjected to clinical trials for cancer therapy. In the pancreatic carcinoma cell line CRL-1420, but not in normal African green monkey kidney cell line CV-1, it is selectively accumulated in mitochondria. However, both the specific oncogenes responsible for its selective toxicity toward cancer cells, and its target proteins in these cancer cells, still remain to be determined. This study was conducted using normal and ras-transformed NIH 3T3 fibroblasts to determine whether oncogenic ras mutants such as v-Ha-ras are responsible for the selective toxicity of MKT-077 and also to identify its targets, using its derivative called "compound 1" as a specific ligand. We have found that v-Ha-ras is responsible for the selective toxicity of MKT-077 in both in vitro and in vivo. Furthermore, we have identified and affinity purified at least two distinct proteins of 45 kD (p45) and 75 kD (p75), which bind MKT-077 in v-Ha-ras-transformed cells but not in parental normal cells. Microsequencing analysis has revealed that the p45 is a mixture of beta- and gamma-actin, whereas the p75 is HSC70, a constitutive member of the Hsp70 heat shock adenosine triphosphatase family, which inactivates the tumor suppressor p53. MKT-077 binds actin directly, bundles actin filaments by cross-linking, and blocks membrane ruffling. Like a few F-actin-bundling proteins such as HS1, alpha-actinin, and vinculin as well as F-actin cappers such as tensin and chaetoglobosin K (CK), the F-actin-bundling drug MKT-077 suppresses ras transformation by blocking membrane ruffling. These findings suggest that other selective F-actin-bundling/capping compounds are also potentially useful for the chemotherapy of ras-associated cancers.  相似文献   
34.
SUBJECTS AND METHODS: Two cases with stage II tongue cancer who exhibited different responses to intra-and peri-tumoral administration of rlL-2 alone are presented. Special consideration is given to the relationship between tumor responses to rlL-2 and clinicopatholog-ical and immunohistopathological findings.
RESULTS: The patient who responded completely to treatment showed an exophytic tumor growth pattern, low-grade cancer invasion, and predominant infiltration of CD8+ lymphocytes over CD4+ lymphocytes in cancer cell nests. The non-responder showed endophytic tumor growth, high-grade cancer invasion, and uniform distribution of both CD4+ and CD8+ lymphocytes in cancer cell nests.
CONCLUSIONS: Distribution of adequate amounts of T lymphocytes subsets may be necessary in order for good tumor response to biotherapy with rlL-2; other clinical and histopathological variables predicting the effect for cancer chemotherapy remain to be identified.  相似文献   
35.
36.
37.
38.
Heterogeneity of chemosensitivity of esophageal and gastric carcinoma   总被引:9,自引:0,他引:9  
Esophageal and gastric cancer have a poor prognosis, and chemotherapy is rarely of long-term benefit. This may be related in part to heterogeneity of chemosensitivity and to constitutive resistance to individual cytotoxic drugs. This study aimed to demonstrate the degree of heterogeneity of chemosensitivity between tumors. We have examined the heterogeneity of chemosensitivity in esophageal and gastric cancer specimens (n=85) using an ex vivo ATP-based chemosensitivity assay (ATP-TCA). A variety of chemotherapeutic agents were tested. Sixty-four specimens were endoscopic biopsy samples; the remainder were from resection specimens. Cells were obtained from 62 specimens (73%). Eight assays were infected due to contamination/infection of the biopsy material, giving an evaluability rate of 87%. Analysis of the data showed considerable heterogeneity of chemosensitivity. The most active single agents identified by the assay were mitomycin C (56% sensitivity) and 5-fluorouracil (5-FU; 42% sensitivity). Exposure of tumor cells to combinations of drugs showed ECF (epirubicin, cisplatin, 5-FU) and mitomycin C+5-FU to be moderately active regimens. Other experimental drug combinations showed greater activity. There is a marked heterogeneity of chemosensitivity in esophageal and gastric cancers. The degree of heterogeneity observed suggests that the ATP-TCA could be used to individualize chemotherapy by selecting agents for particular patients. This approach provides the rationale for a trial of ATP-TCA-directed therapy to determine whether individualization of chemotherapy might improve patient response and survival.  相似文献   
39.
In the isolated rat aorta, a ROCKs (rhoA-dependent coiled coil serine/threonine kinases) inhibitor, Y-27632, inhibited the contractions induced not only by receptor agonists but also by high K(+) with the similar IC(50) values (0.8 - 4.9 microM). However, Y-27632 did not inhibit the increment of cytosolic Ca(2+) concentration ([Ca(2+)](i)) due to these stimulants. The Y-27632-induced inhibition of contraction was accompanied by an inhibition of myocin light chain (MLC) phosphorylation, although inhibition of contraction was stronger than that of MLC phosphorylation during the initial phase of contraction. Y-27632 had no effect on the myocin light chain kinase (MLCK) activity. This inhibitor also did not directly change the phosphatase activity. These results suggest that Y-27632 is a selective inhibitor of ROCKs with no direct inhibitory effect on [Ca(2+)](i), calmodulin, MLCK, or phosphatase. Y-27632 disrupted the actin filament network and decreased the filamentous actin, implying that the stronger inhibition by Y-27632 on early phase of contraction than MLC phosphorylation may be explained by this effect. These results suggest that the high K(+)-induced MLC phosphorylation and contraction are mediated not only by the classical Ca(2+)/calmodulin-dependent MLCK system but also by a novel MLC phosphorylation pathway involving ROCKs. One of the possibilities is that high K(+) activates ROCKs to inhibit myosin phosphatase resulting in an augmentation of MLC phosphorylation and contraction.  相似文献   
40.
BACKGROUND: Although metastasis of cancer in the oral region to the submandibular node is well described, there has been no anatomic representation of lymph vessels penetrating the oral floor and draining into the node. MATERIALS AND METHODS: Ninety specimens were obtained from formalin-fixed, donated cadavers. Histologic observations using serial sections followed the macroscopic observations. RESULTS: In 19 of 90 specimens, we found afferent collecting lymph vessels exiting from the mylohyoid surface and draining into the preglandular submandibular node. In 3 of the 19 specimens, collecting vessels passing through the narrow muscle gap with or without arteries, veins, and nerves were identified histologically. The postglandular submandibular node was not evident in the drainage route. CONCLUSIONS: Although it carries a low incidence, because of the direct lymphatic route or pathway between the oral region and preglandular submandibular node, the pathologically positive supraomohyoid node sometimes seems to be found even in elective neck dissection. However, we speculate that sentinel node investigation would reveal the much more critical role of the jugulodigastric node not only as the actual sentinel node but also as the common terminal node along the various drainage routes from the oral region.  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