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   297篇
  免费   14篇
儿科学   1篇
基础医学   57篇
口腔科学   2篇
临床医学   16篇
内科学   65篇
皮肤病学   34篇
神经病学   22篇
特种医学   9篇
外科学   38篇
预防医学   16篇
眼科学   1篇
药学   18篇
肿瘤学   32篇
  2022年   3篇
  2021年   2篇
  2020年   5篇
  2018年   7篇
  2017年   7篇
  2016年   7篇
  2015年   4篇
  2014年   4篇
  2013年   6篇
  2012年   21篇
  2011年   12篇
  2010年   9篇
  2009年   5篇
  2008年   17篇
  2007年   14篇
  2006年   15篇
  2005年   12篇
  2004年   7篇
  2003年   17篇
  2002年   8篇
  2001年   7篇
  2000年   10篇
  1999年   5篇
  1997年   4篇
  1994年   3篇
  1993年   4篇
  1992年   11篇
  1991年   5篇
  1990年   2篇
  1989年   3篇
  1988年   3篇
  1987年   4篇
  1986年   6篇
  1985年   13篇
  1984年   12篇
  1983年   6篇
  1982年   1篇
  1981年   2篇
  1980年   2篇
  1979年   3篇
  1978年   2篇
  1976年   1篇
  1975年   6篇
  1974年   4篇
  1973年   1篇
  1971年   1篇
  1970年   3篇
  1969年   1篇
  1968年   1篇
  1965年   1篇
排序方式: 共有311条查询结果,搜索用时 31 毫秒
91.
Recently developed expandable metallic stents have been adopted to superior vena cava syndrome with good results. We inserted stents into the superior vena cava in 4 patients with superior vena cava syndrome. The results were comfortable and no complications. We should consider the stenting as the first choice for superior vena cava syndrome.  相似文献   
92.
BACKGROUND: Very few population based cohort studies have focused on the long term recurrence of stroke. OBJECTIVE: To examine 10 year cumulative recurrence rates for stroke in a Japanese cohort according to pathological type and clinical subtype of brain infarction. METHODS: During a 32 year follow up of 1621 subjects >/=40 years of age, 410 developed first ever stroke. These were followed up prospectively for 10 years after stroke onset. RESULTS: During follow up, 108 (26%) experienced recurrent stroke. The cumulative recurrence rates were 35.3% at five years and 51.3% at 10 years. The 10 year recurrence rates of subarachnoid haemorrhage (SAH), brain haemorrhage, and brain infarction were 70.0%, 55.6%, and 49.7%, respectively; the difference between SAH and brain infarction was significant (p = 0.004). Most recurrent episodes after SAH or brain haemorrhage happened within a year after the index stroke, whereas recurrence of brain infarction increased consistently throughout the observation period. Cardioembolic stroke had a higher recurrence rate (75.2%) than lacunar infarction (46.8%) (p = 0.049). The 10 year risk of stroke recurrence increased with age after lacunar or atherothrombotic brain infarction, but not after the other types or subtypes. After atherothrombotic brain infarction, cardioembolic stroke, or SAH, the type and subtype of most recurrent strokes were the same as for the index stroke, but recurrence after lacunar infarction or brain haemorrhage showed divergent patterns. CONCLUSIONS: Japanese people have higher recurrence rates of stroke than other populations. Recurrence rate after a first brain infarct increases consistently through the next 10 years.  相似文献   
93.
94.
OBJECTIVE: Several studies have shown associations between diabetes and various types of cancer other than gastric cancer. The aim of this cohort study was to evaluate the impact of fasting plasma glucose (FPG) levels on gastric cancer occurrence. RESEARCH DESIGN AND METHODS: A total of 2,466 Japanese subjects aged > or =40 years were stratified into three groups according to FPG tertiles (<5.3 mmol/l, low FPG; 5.3-5.8 mmol/l, modest FPG; >5.8 mmol/l, high FPG) and followed up prospectively for 9 years. RESULTS: During the follow-up, 66 subjects experienced gastric cancer. In men, the age-adjusted incidences were significantly higher in the modest-FPG (7.0 per 1,000 person-years, P < 0.05) and high-FPG (7.2, P < 0.05) groups than in the low-FPG group (2.2). In women, the high-FPG group also had a significantly higher age-adjusted incidence of gastric cancer compared with the low-FPG group (2.5 vs. 0.8, P < 0.05). The multivariate analysis with Cox's proportional hazards model revealed that the risks of gastric cancer in the modest-FPG (relative risk [RR] 2.3 [95% CI 1.1-5.0]) and high-FPG (3.1 [1.5-6.4]) groups were significantly higher than that in the low-FPG group, even after adjusting for other comprehensive risk factors, including Helicobacter pylori status, smoking, and dietary factors. However, this FPG-cancer association was observed only among H. pylori-seropositive subjects. CONCLUSIONS: Our findings suggest that a modest increase in FPG is a risk factor for gastric cancer and that hyperglycemia is a possible cofactor increasing the risk posed by Helicobacter pylori infection.  相似文献   
95.
Intracranial germinomas are accompanied occasionally by a significant granulomatous change and abundant fibrous tissue, and this has made their pathological diagnosis difficult. However, the incidence of the granulomatous reaction and the presence of fibrous tissue together with their clinical characteristics in intracranial germinomas have not been fully investigated. Twenty-four germinomas, none of which had received preoperative treatment, were clinicopathologically examined. The location of the tumor was the pineal region (5 cases), the suprasellar region (13 cases), multiple lesions (2 cases), the basal ganglia region (1 case), and other regions (3 cases). Histologically, the germinomas could be divided into two types: (1) type A (18 cases) consisted mainly of large neoplastic cells and small lymphocytes, showing a two-cell pattern; (2) type B (6 cases) consisted predominantly of fibroinflammatory tissues containing occasional neoplastic cells (5/6 cases) and, rarely, neoplastic cells (1/6 cases). Perioperatively, two-cell-pattern germinomas (type A) were characterized as soft tumors and fibroinflammatory germinomas (type B) as hard tumors. Thus, the fibroinflammatory type B accounted for 25% of the intracranial germinomas. Although there were no topographical and clinical differences between the two types, we conclude that immunohistological studies to detect neoplastic germ cells are warranted in cases of small stereotactic biopsies of hard type B tumors.  相似文献   
96.
Summary.  Objective: Pure germinomas have a good prognosis compared to those with syncytiotrophoblastic giant cells (STGCs), which show elevated human chorionic gonadotropin or human chorionic gonadotropin-beta (hCG/hCG-beta) levels and relapse frequently. However, the long-term outcome of patients with germinoma and detectable hCG/hCG-beta in cerebrospinal fluid (CSF) but not in serum is unclear.  Materials and Methods: The outcome of patients with pure germinomas (no increase in hCG/hCG-beta in serum or CSF, 13 cases; group A), germinomas with STGC (increased hCG/hCG-beta in serum, 13 cases; group B) and germinomas with increased hCG/hCG-beta only in CSF (6 cases; group C) was analyzed.  Results: All three groups received similar radiotherapy. Groups A and C each showed a 10-year survival rate of 100%, while this was only 69.2% in group B. The 10-year relapse-free survival rates were 92.3%, 69.2% and 83.3% (groups A, B and C, respectively). Groups A and C each had one case of tumor relapse, but there was no recurrence simply by the application of radiotherapy. On the other hand, in group B, tumor relapse was seen in 4/13 (30.8%) cases. Three of them showed relapse within the region of the initial radiation exposure and died despite all available treatment.  Conclusion: Patients with an increased hCG/hCG-beta level in CSF may be considered to be similar to pure germinomas and should be treated and followed-up carefully. Published online October 31, 2002 Acknowledgments  We greatly appreciate the technical assistance of Miss Yoshie Yasui. This work was supported in part by Grants-in-Aid for Scientific Research from the Ministry of Education (Nos. 08671611, 10877218, and 13671462) and an Academic Frontier Project from the Ministry of Education, Science and Culture, and a Parent's Association Grant from Kitasato University, School of Medicine, Japan. Correspondence: S. Utsuki, M.D., Department of Neurosurgery, Kitasato University School of Medicine, 1-15-1 Kitasato, Sagamihara, Kanagawa 228-8555 Japan.  相似文献   
97.
98.
Neisseria meningitidis serogroup C polysaccharide (PS C) was conjugated to serogroup B outer membrane vesicles (OMV) in order to test the possibility of obtaining a bivalent group B and C meningococcus vaccine. The conjugate and controls were injected intraperitoneally into groups of ten mice with boosters on days 14 and 28 after the primary immunization. The following groups were used as control: (i) PS C; (ii) PS C plus OMV; (iii) OMV; and (iv) saline. The serum collected on days 0, 14, 28 and 42 were tested by enzyme-linked immunosorbent assay (ELISA) for PS C and OMV, and by complement mediated bactericidal assay against serogroups B and C. ELISA for PS C as well as bactericidal titres against serogroup C meningococci of the conjugated vaccine increased eight-fold (ELISA) and 32 fold (bactericidal) after 42 days in comparison with the PS C control group. ELISA for OMV and bactericidal titre against serogroup B meningococci of the conjugate showed no significant difference in comparison with the OMV containing controls. Furthermore, Western Blot assay of the conjugate immune serum did not bind OMV class four protein which is related to the complement dependent antibody suppressor. The results indicate that the PS C-OMV conjugate could be a candidate for a bivalent vaccine toward serogroups B and C meningococci.  相似文献   
99.
100.
BACKGROUND: How leukotrienes (LTs) and IgE-mediated allergy reflect clinical features in patients with chronic obstructive pulmonary disease (COPD) remains unclear. OBJECTIVE: Our goal was to determine whether LTB4 and LTC4 would correlate with airway obstruction and whether IgE-mediated allergy would influence the generation of LTs and bronchial hyperresponsiveness in patients with COPD. METHODS: We measured the pulmonary function, methacholine bronchial hyperresponsiveness, and generation of LTB4 and LTC4 from peripheral leukocytes stimulated with calcium ionophore A23187 in relation to the presence of specific IgE antibodies against inhalant allergens. RESULTS: The leukocytes of patients with COPD generated significantly more LTB4 (with allergy, P <.001; without allergy, P <.001) and LTC4 (with allergy, P <.001; without allergy, P <.01) than the leukocytes of the control subjects. LTC4 production was significantly higher in the allergic COPD subjects than in the nonallergic COPD patients (P <.01), but the amount of LTB4 generated was not significantly different. FEV(1) significantly correlated with the level of both LTB4 (with allergy, r = -0.556, P =.0375; without allergy, r = -0.731, P =.0046) and LTC4 (with allergy, r = -0.764, P =.0043; without allergy, r = -0.526, P =.0414) generation in COPD. The log(10) of the minimum dose of methacholine was significantly higher in COPD patients without allergy than in those with allergy (P <.05). CONCLUSION: Enhanced LT generation from peripheral leukocytes is observed in patients with COPD, and the presence of specific IgE antibodies against inhalant allergens enhances LTC4 generation, bronchial hyperresponsiveness, and the relationship between LTC4 generation and airway obstruction.  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