首页 | 官方网站   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   5469篇
  免费   268篇
  国内免费   26篇
医药卫生   5763篇
  2023年   36篇
  2022年   54篇
  2021年   77篇
  2020年   58篇
  2019年   98篇
  2018年   113篇
  2017年   101篇
  2016年   103篇
  2015年   106篇
  2014年   155篇
  2013年   180篇
  2012年   318篇
  2011年   357篇
  2010年   218篇
  2009年   174篇
  2008年   306篇
  2007年   357篇
  2006年   339篇
  2005年   352篇
  2004年   287篇
  2003年   295篇
  2002年   311篇
  2001年   121篇
  2000年   121篇
  1999年   143篇
  1998年   88篇
  1997年   54篇
  1996年   58篇
  1995年   44篇
  1994年   42篇
  1993年   43篇
  1992年   67篇
  1991年   55篇
  1990年   53篇
  1989年   50篇
  1988年   40篇
  1987年   44篇
  1986年   55篇
  1985年   41篇
  1984年   32篇
  1983年   28篇
  1982年   17篇
  1981年   18篇
  1980年   25篇
  1979年   16篇
  1978年   13篇
  1977年   12篇
  1976年   11篇
  1975年   13篇
  1973年   13篇
排序方式: 共有5763条查询结果,搜索用时 15 毫秒
1.
Humoral hypercalcemia of malignancy (HHM) in neoplastic syndrome has been most commonly reported in squamous cell carcinoma. Gallbladder carcinoma with HHM is uncommon. In this report, we describe a male case of gallbladder carcinoma with marked hypercalcemia and a high level of serum parathyroid hormone-related peptide (PTHrP). An immunohistochemical examination using PTHrP was also positive.  相似文献   
2.
3.
Vasopressin, a hormone secreted from the posterior lobe of the hypophysis, has endocrinological and antidiuretic effects; it contracts vessels and smooth muscles, especially intestinal smooth muscle. In the present study, we investigated the role of vasopressin (Pitressin: arginine-vasopressin) in elimination of intestinal gas on excretory urography reading. Sixty outpatients were randomly divided into six groups. In Group I, the routine procedure was employed, i.e. laxatives the previous night and NPO the morning of the examination. In Groups II to VI, different dose regimens were employed: 6 or 10 units of Pitressin was administered by subcutaneous injection 30 minutes prior to injection of a contrast medium, with or without NPO. Intestinal gas elimination was evaluated by X-ray films taken before and after injection of Pitressin. The efficacy was rated by four grades. There were no significant differences in the gas elimination or occurrence of side effects between any two groups. Younger patients seemed to respond quickly to Pitressin and good effects were obtained. These results indicate that the pretreatment for excretory urography with 6 units of Pitressin without NPO may be a safe and effective alternative method for elimination of intestinal gas, in particular for young patients.  相似文献   
4.
An examination was made of neurogenesis in the anteroventral periventricular nucleus (AVPv) of the preoptic area of the rat using bromodeoxyuridine (BrdU), a thymidine analog, and a BrdU-specific antibody. Cells in the AVPv of adult rats were labeled with the antibody when BrdU was injected into pregnant rats once during day 13 to 18 of gestation, but not during day 10 to 12 nor 19 to 20 of gestation nor on postnatal day 1, indicating that neurogenesis of the AVPv occurs during a limited period from day 13 to 18 of gestation. Next, to examine the effects of androgen on neurogenesis, BrdU was injected once on day 15 into pregnant rats that also received injections of testosterone propionate (TP). The number of BrdU-labeled cells in the AVPv was similar in control female and male fetuses and female fetuses from pregnant rats that received daily injections of TP during days 14 to 16, when fetuses were examined on day 17 of gestation. These results suggest that the neurogenesis that was recognized by labeling with BrdU was not affected by the treatment with TP. On day 21 of gestation, BrdU-labeled cells in the AVPv of control male fetuses and female fetuses that received TP during days 14 to 18 were fewer in number than those in female fetuses of the control group, whereas treatments with TP during days 14 to 16 and during days 17 to 18 did not cause any significant decrease in number of BrdU-labeled cells. These findings support the hypothesis that elimination of a population of cells, for example, by cell death as described previously, is enhanced in male fetuses and in female fetuses treated with TP repetitively.  相似文献   
5.
A 47-year-old male was concerned with a large AVM involved extensively in the parietal region and the posterior fossa. Radiological examinations showed multiple radiolucencies in the parietal and occipital bone and torturous vascular nets (nidus) in those bones on the angiograms. Nidus was found also in the dura mater in the posterior fossa. Therefore, this case seemed to be an extremely rare case of calvarial AVM in the parietal region with the mixed calvarial dural AVM in the posterior fossa. His symptoms were bruit, transient hemiparesis and Gerstmann's syndrome in addition to the symptoms due to raised intracranial pressure. Favorable results of therapies could be attained by extensive exfoliation of dura mater from the cranial bone and incision of proximal dura mater in the sinus.  相似文献   
6.
The significance of preoperative chemoembolization using ethiodized oil, cisplatin and gelatin sponge (Sandwich therapy) for resectable hepatocellular carcinoma (HCC) was evaluated. One hundred and thirteen patients with solitary and less than 10 cm sized HCC who underwent radical hepatic resection were chosen for this study. Fifty-three patients received Sandwich therapy before surgery (Group A), and the remaining 60 patients under-went surgery without any preoperative treatments (Group B). Any background factors between two groups were not significantly different. The anticancer effects of this therapy were evaluated by histologic examination in 31 patients who had preoperative Sandwich therapy. In 22 of 31 patients (71%), the main nodules were completely necrotic. The ratios of patients with complete necrosis in daughter nodules were 7/12 (58%), in portal vein tumor emboli, 7/10 (70%), in intracapsular invasions, 11/21 (52%), in extracapsular invasions, 4/11 (36%). The 4-year disease-free survival rates in Group A and Group B were 56% and 27% respectively, and the rate of the former was significantly higher than that of the latter (p less than 0.05). The 4-year survival rates in Group A and Group B were 83% and 53% respectively. The rate of Group A was also significantly higher than that of Group B (p less than 0.01). We concluded that preoperative Sandwich therapy was very significant to obtain successful long-term disease-free survival and survival in regard to relatively early stage HCC.  相似文献   
7.
We used morphological, biochemical and immunohistochemical methods to assess the response of Müller cells after experimental lensectomy-vitrectomy in rabbits. We observed widened intercellular spaces between the Müller cells and nerve fibers of ganglion cells, and increased electron opacity in the Müller cells of eyes injected with silicone oil. No apparent morphological changes were detected in the Müller cells of air-injected eyes. The specific and total activities of Müller cell-marker enzymes (glucose 6-phosphatase and glutamine synthetase) showed an initial increase, followed by a decrease. Glial fibrillary acidic protein immunoreactivity was not found in the Müller cells of the normal rabbit retina but was exhibited after surgery. Our results showed that markers of Müller cells associated with glycogenolysis and/or gluconeogenesis, glutamate-glutamine cycle and cytoskeletal protein metabolism were affected by the experimental lensectomy-vitrectomy.  相似文献   
8.
9.
The cause of aplastic anemia associated with hepatitis (AAH) is as yet still unknown. There is a supposed relation to the immune mechanisms, however few reports have shown the effects of monocytes on the pathogenesis in the patients with AAH. We have reported a case of a 12-year-old boy with AAH related to cytomegaloviruses, and studied the hemopoietic progenitors. He showed pancytopenia and hypoplasia of the bone marrow on admission to our hospital. The culture studies showed that mononuclear cells (MNC) of the bone marrow produced few hemopoietic colonies in all cell lineages. However, the depletion of adherent cells from the MNC increased numbers of erythroid, neutrophil-macrophage and megakaryocyte colonies. Furthermore, the addition of adherent cells of the peripheral blood suppressed the colony formation in the aforementioned cell lineages by marrow MNC from which adherent cells, phagocytic cells and T-cells were abrogated. The results way suggest that monocytes play some soles in the pathogenesis of aplasia through inhibitor of hemopoiesis.  相似文献   
10.
The treatment of patients with anterior abdominal stab wounds remains controversial. We reserve celiotomy for patients who have clinical findings of peritonitis or hemorrhage. Repeated physical examination is the most important element of observation. Recently, 330 patients with stable abdominal stab wounds presented over a 12-month period. These patients were followed up with serial physical examinations and laboratory measurements. Of the 330 patients, 107 patients (32%) required celiotomy for the repair of a life-threatening injury (group 1); 28 patients (8%) underwent nontherapeutic celiotomies (group 2); 19 patients (6%) had negative explorations (group 3); and 176 patients (53%) were observed and discharged (group 4). There were three missed injuries in group 4. Serial physical examination can be a reliable technique in the management of abdominal stab wounds and is comparable to other approaches.  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-23

京公网安备 11010802026262号