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   552篇
  免费   27篇
  国内免费   19篇
耳鼻咽喉   3篇
儿科学   25篇
妇产科学   10篇
基础医学   56篇
口腔科学   11篇
临床医学   70篇
内科学   167篇
皮肤病学   11篇
神经病学   30篇
特种医学   46篇
外科学   64篇
综合类   22篇
预防医学   26篇
眼科学   3篇
药学   34篇
肿瘤学   20篇
  2018年   4篇
  2017年   4篇
  2016年   6篇
  2015年   15篇
  2014年   16篇
  2013年   15篇
  2012年   11篇
  2011年   8篇
  2010年   30篇
  2009年   23篇
  2008年   9篇
  2007年   20篇
  2006年   10篇
  2005年   11篇
  2004年   6篇
  2003年   8篇
  2002年   12篇
  2001年   11篇
  2000年   11篇
  1999年   11篇
  1998年   30篇
  1997年   19篇
  1996年   25篇
  1995年   13篇
  1994年   12篇
  1993年   15篇
  1992年   6篇
  1991年   13篇
  1990年   6篇
  1989年   15篇
  1988年   16篇
  1987年   9篇
  1986年   6篇
  1985年   7篇
  1983年   4篇
  1982年   7篇
  1980年   6篇
  1975年   3篇
  1972年   3篇
  1968年   3篇
  1962年   3篇
  1959年   15篇
  1958年   16篇
  1957年   14篇
  1956年   10篇
  1955年   15篇
  1954年   19篇
  1952年   5篇
  1949年   3篇
  1948年   4篇
排序方式: 共有598条查询结果,搜索用时 15 毫秒
31.
Background: Central nervous system (CNS) complications such as seizures and reduced consciousness are important in glufosinate and may occur in severe glyphosate poisoning. The aim of this study was to assess the possible role of serum S100B protein as a biochemical marker of CNS complications associated with glyphosate or glufosinate poisoning.

Methods: The study enrolled 40 patients (23 glyphosate poisoning and 17 glufosinate poisoning). Altered consciousness and seizure were observed during hospitalization. S100B level was measured with fully automated modular analytic E170 system using electrochemoluminometric immunoassay.

Results: Among 40 patients, neurologic features were observed in 12 patients with a median time to onset of 21.5 (IQR 8.25–24.75) h. Serum S100B concentrations measured on admission were higher in the group with neurologic features than in the group without neurologic features [0.148?μg/L (IQR 0.128–0.248) vs. 0.072?μg/L (IQR 0.047–0.084), p?Conclusions: In our pilot study, S100B was a significant predictor of neurologic complications in patients with glyphosate and glufosinate poisoning. Large prospective cohorts are needed to confirm this finding.  相似文献   
32.
BACKGROUND: Recently, neoadjuvant radio-chemotherapy has been demonstrated to induce tumour remission and to prolong survival of patients with locally advanced adenocarcinoma of the oesophagogastric junction.The present study was performed to re-evaluate these data. PATIENTS AND METHOD: A non-randomised trial of multimodal treatment was conducted in order to investigate histopathologic response and survival of patients with adenocarcinoma of the oesophagogastric junction. Treatment consisted of 2 courses of combined chemotherapy with 15 mg/kg 5-fluorouracil on days 1-5 and 75 mg/m(2) cisplatin on day 8 and simultaneous radiation (40 Gy), and a second course starting on day 36, followed by surgery. Abdomino-thoracic oesophagectomy and systematic 2-field lymphadenectomy were performed in patients with Barrett's carcinoma. D2-gastrectomy was performed in patients with type 2 or 3 cancer of the oesophagogastric junction according to the Siewert classification. Probability of survival was estimated using the Kaplan-Meier method. RESULTS: 16 patients with a mean age of 57 years were enrolled in this study. Surgery was performed in 14 of these patients. Response to treatment was evident in 10 patients, but none of these patients had complete histopathologic response. Toxicity related to radiochemotherapy was mild to moderate (37.5%). Perioperative complications, both medical and surgical, occurred in 71.4% of patients. 2 patients had fatal complications. 30-day mortality was 25.4%. The probability of survival at 2 years after surgery was 61.2%. CONCLUSION: Neoadjuvant radio-chemotherapy followed by surgery for cancer of the oesophagogastric junction is associated with a considerable rate of complications. Histopathologic response to radio-chemotherapy is poor. In consequence of these preliminary results, the present study was terminated and the protocol of a future study was modified.  相似文献   
33.
Malignant intestinal non-Hodgkin's lymphoma from the surgical point of view   总被引:1,自引:0,他引:1  
Samel S  Wagner J  Hofheinz R  Sturm J  Post S 《Onkologie》2002,25(3):268-271
BACKGROUND: Primary intestinal non-Hodgkin's lymphoma (I-NHL) is much less frequent than gastric lymphoma and has hardly been studied in prospective trails. To the surgeon, patients frequently present with abdominal emergencies. PATIENTS AND METHODS: A consecutive series of patients subjected to surgery because of I-NHL between 1998 and 1999 was evaluated retrospectively for characteristic clinical, radiographic and intraoperative findings. Patients with gastric lymphoma were not considered. RESULTS: 10 patients, 8 males and 2 females, with I-NHL were subjected to first-line surgery because of painful abdominal tumor, intestinal hemorrhage, obstruction or perforation. I-NHL was located most often in the small bowel (n = 7). It was rare in the colon (n = 2) and the duodenum (n = 1). Median postoperative follow-up was 28 months. Perioperative mortality was 10% (n = 1). Probability of survival 3 years after surgery was 60%. CONCLUSIONS: Patients with I-NHL frequently present with complications of tumor growth, requiring urgent surgical treatment. Irrespective of surgical complications we advocate surgery in cases of resectable disease as first-line treatment. Adjuvant treatment is indicated with respect to resection status and histopathological staging.  相似文献   
34.
Primary osteogenic sarcoma of the skull is an exceedingly rare condition. An adult male patient is described, who had a painless swelling in the right forehead that had rapidly enlarged in the previous 6 months. Radiological investigations showed a large destructive mass lesion involving the right side of the frontal bone with extension into the frontal sinus, causing marked extradural compression of brain parenchyma. Histopathological examination confirmed the lesion to be primary osteogenic sarcoma.  相似文献   
35.
The present study investigated the expression and distribution of three isoforms of nitric oxide synthase (NOS) in different anatomical regions of the human stomach and in gastric neoplastic tissues by immunohistochemistry using specific antibodies. Intracellular localization of individual isoenzymes of NOS was detected in normal gastric mucosa. Gastric cancer tissues had a marked reduction of all three NOS isoforms expression. The expression of the endothelial NOS, neuronal NOS and inducible NOS in the tumor tissue was significantly lower than in normal gastric mucosa (P = 0.01, P = 0.02, P < 0.01, respectively). In the tumor tissue the expression of inducible NOS was significantly lower than the expression of both constitutive forms of NOS (P < 0.01). There was a tendency to higher expression of both constitutive forms of NOS in earlier stages T2 of the tumor compared to advanced T4 tumor. In contrast, the expression of inducible NOS was higher than in the advanced T4 tumor than in the earlier stages T2 of the tumor. The mapping of the expression of endothelial NOS, neuronal NOS and inducible NOS in human stomach showed higher expression of NOS isoforms in the distal third than in the proximal third of the stomach (P = 0.03, P = 0.04, P = 0.01, respectively). We conclude that there is greater expression of NOS in the stomach corpus and in antrum than in the proximal third of the normal human stomach mirroring the anatomical predilection of common pathological changes in this part of the human stomach. Furthermore, there was loss of the expression of individual isoenzymes in gastric neoplasms.   相似文献   
36.
37.
The rare neoplastic cystic adenomas of the pancreas form two groups of tumors: macrocystic mucinous and microcystic serous adenomas. Both entities show specific radiologic and histologic features. Several recent case reports, however, suggest some diversity within the group of microcystic serous adenomas. We present the case of a young man operated because of epigastric pain for 12 months and a palpable microcystic tumor of the pancreatic head. Multiple cysts communicating with branches of the pancreatic duct in an alveolar-like pattern were demonstrated on endoscopic retrograde cholangiopancreatography. Histologic examination of the specimen confirmed the diagnosis of a serous adenoma of the pancreas. The tumor morphology in this case may suggest a ductal origin of microcystic serous adenomas.  相似文献   
38.
The derivation of Reed-Sternberg cells in Hodgkin's lymphoma has been a subject of great interest. In most cases, Reed-Sternberg cells seem to be derived from germinal center B cells. In few sporadic cases, a T-cell origin has been shown. This article supports the concept of a T-cell derivation for rare cases of Hodgkin's lymphoma and provides evidence of a novel mechanism of pathogenesis from chronic inflammation in the skin.  相似文献   
39.
Lord  ST; Fowlkes  DM 《Blood》1989,73(1):166-171
The initial event in fibrin clot formation is the thrombin-catalyzed cleavage of the A alpha chain of human fibrinogen. Most of the information required for thrombin recognition and cleavage of the A alpha chain lies in the amino terminal 51 residue CNBr fragment. By selective modification of residues in this region, we probed the features that participate in thrombin interactions. We constructed a vector which expressed a tripartite protein (tribrid) consisting of amino acids 1 to 50 of the A alpha chain followed by 60 amino acids of chicken collagen and the beta-galactosidase protein from Escherichia coli. Cell lysates run on NaDodSO4-polyacrylamide gels contained the predicted band of molecular weight (mol wt) 125,000. The tribrid reacted with a monoclonal antibody, Mab-Y18, which recognizes the amino terminus of the A alpha chain. When cell lysates were incubated with thrombin, FPA was released. By including one heterogeneous oligonucleotide in the construction, we generated plasmids that encoded three specific amino acid substitutions. Surprisingly, changing Gly14 to Val did not alter thrombin cleavage, although recognition by Mab-Y18 was lost. Substitution of lie for Arg23 did not alter either thrombin cleavage or monoclonal recognition. Substitution of Leu for Arg 16 altered thrombin cleavage; unexpectedly, recognition by Mab-Y18 was not changed.  相似文献   
40.
The study was performed as the second part of an investigation to assess sleep behavior and circadian rhythmicity in aircrew operating regular passenger flights between Germany and East Asia via Anchorage (ANC). Continuous records of sleep and ratings of sleep quality were obtained by sleep logs from 101 B747-cockpit crewmembers, starting at least 3 d before commencing flight duty, continuing during days on duty (the duration depending on the flight schedule) and finishing 4 d after return, at the earliest. Regardless of the specific duty roster, sleep deficit occurred mainly after the first flight leg to ANC, presumably due to the 10-h time zone difference and the short layover time. During the layover in the Far East, the sleep deficit diminished partly because of additional naps. Sleep was often disturbed and scattered over days and nights. Another pronounced sleep deficit occurred after the first return flight from South Korea or Japan to ANC. Compared to the outgoing layover period in ANC, the number and duration of naps increased during this layover and, additionally, on the first 2 d after returning home. Poorer sleep quality ratings were associated with accumulated sleep deficit and increased napping, but significant decrements in sleep quality were seen only during two out of the six different duty rosters. All six of the polar route duty rosters may lead to significant sleep disturbances. During some flight schedules the sleep deficit is large enough to raise operational implications.  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