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   46052篇
  免费   2327篇
  国内免费   198篇
耳鼻咽喉   753篇
儿科学   849篇
妇产科学   832篇
基础医学   6165篇
口腔科学   1355篇
临床医学   3204篇
内科学   10916篇
皮肤病学   815篇
神经病学   3822篇
特种医学   1542篇
外科学   7392篇
综合类   194篇
一般理论   3篇
预防医学   1794篇
眼科学   777篇
药学   3877篇
中国医学   116篇
肿瘤学   4171篇
  2023年   209篇
  2021年   690篇
  2020年   448篇
  2019年   615篇
  2018年   767篇
  2017年   622篇
  2016年   729篇
  2015年   765篇
  2014年   1048篇
  2013年   1336篇
  2012年   2103篇
  2011年   2279篇
  2010年   1320篇
  2009年   1177篇
  2008年   2098篇
  2007年   2312篇
  2006年   2230篇
  2005年   2205篇
  2004年   2171篇
  2003年   2164篇
  2002年   2062篇
  2001年   1654篇
  2000年   1788篇
  1999年   1514篇
  1998年   472篇
  1997年   375篇
  1996年   349篇
  1995年   323篇
  1994年   299篇
  1993年   271篇
  1992年   1109篇
  1991年   928篇
  1990年   907篇
  1989年   947篇
  1988年   836篇
  1987年   841篇
  1986年   787篇
  1985年   774篇
  1984年   536篇
  1983年   429篇
  1982年   222篇
  1979年   484篇
  1978年   277篇
  1977年   255篇
  1975年   212篇
  1974年   230篇
  1972年   209篇
  1971年   231篇
  1969年   232篇
  1968年   216篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
The association between kidney function and cancer incidence is inconsistent among previous reports, and data on the Japanese population are lacking. It is unknown whether kidney function modifies the cancer risk of other factors. We aimed to evaluate the association of estimated glomerular filtration rate (eGFR) with cancer incidence and mortality in 55 242 participants (median age, 57 years; 55% women) from the Japan Multi-Institutional Collaborative Cohort Study. We also investigated differences in cancer risk factors between individuals with and without kidney dysfunction. During a median 9.3-year follow-up period, 4278 (7.7%) subjects developed cancer. Moderately low and high eGFRs were associated with higher cancer incidence; compared with eGFR of 60-74 ml/min/1.73 m2, the adjusted hazard ratios (HRs) (95% confidence intervals [CIs]) for eGFRs of ≥90, 75-89, 45-59, 30-44 and 10-29 ml/min/1.73 m2 were 1.18 (1.07-1.29), 1.09 (1.01-1.17), 0.93 (0.83-1.04), 1.36 (1.00-1.84) and 1.12 (0.55-2.26), respectively. High eGFR was associated with higher cancer mortality, while low eGFR was not; the adjusted subdistribution HRs (95% CIs) for eGFRs of ≥90 and 75-89 ml/min/1.73 m2 were 1.58 (1.29-1.94) and 1.27 (1.08-1.50), respectively. Subgroup analyses of participants with eGFRs ≥60 and <60 ml/min/1.73 m2 revealed elevated cancer risks of smoking and family history of cancer in those with eGFR <60 ml/min/1.73 m2, with significant interactions. Our findings suggest that the relationship between eGFR and cancer incidence was U-shaped. Only high eGFR was associated with cancer mortality. Kidney dysfunction enhanced cancer risk from smoking.  相似文献   
3.

Background

Anticoagulation therapy, particularly subcutaneous heparin therapy, is recommended for cancer-associated thrombosis. However, not starting or discontinuing anticoagulation was not rare. The aim of the present study was to examine the practical issues related to anticoagulation therapy and effects of subcutaneous heparin therapy for cancer-associated stroke.

Methods

Patients with cancer-associated stroke in our stroke center between October 2014 and August 2017 who were diagnosed as having acute ischemic stroke based on diffusion-weighted imaging were retrospectively enrolled. Baseline clinical characteristics, heparin injection, reasons for no subcutaneous heparin therapy, and clinical outcomes were collected.

Results

A total of 59 patients with cancer-associated stroke (75 ± 10 years old, male 42%) were enrolled. Lung cancer was the most frequently observed cancer (n = 17, 29%), followed by gastric cancer (n = 8, 14%) and pancreatic cancer (n = 8, 14%). Of the 19 patients (32%) who underwent subcutaneous heparin therapy, it was discontinued in 9 (47%), mainly because of patients’ medical conditions (deterioration of cancer or hemorrhagic complication). Ten patients with long-term subcutaneous heparin therapy did not have stroke recurrence. In contrast, among nine patients who discontinued subcutaneous heparin therapy, three (33%) had recurrence of ischemic stroke. Of the 40 patients without subcutaneous heparin therapy, the main reasons for no subcutaneous heparin therapy were the patients’ medical conditions (n = 22, 55%).

Conclusions

Although subcutaneous heparin therapy was given to only one third of cancer-associated stroke patients, long-term subcutaneous heparin therapy might prevent recurrence of cancer-associated stroke.  相似文献   
4.
5.
6.
BackgroundAxillary lymph node (LN) dissection after neoadjuvant chemotherapy (NAC) still remains a standard treatment of initially LN-positive primary breast cancer because of the difficulty of assessment of LN status. The aim of this study was to assess the LN status after NAC in initially LN-positive primary breast cancer patients who were assessed as clinically LN-negative after NAC (ycN0) and identify factors associated with loss of LN metastasis.Patients and MethodsThe study cohort comprised 279 patients with cytology-proven LN-positivity before NAC. LN status was assessed by ultrasonography. Regional recurrence-free survival and overall survival according to pathologic LN after NAC (ypN) status were assessed in patients with ycN0.ResultsOf the 279 patients, 179 patients (64.2%) had ycN0. High nuclear grade, estrogen receptor-negative (ER?), and human epidermal growth factor receptor 2-positive (HER2+), were significant predictors of ycN0/ypN0 (P < .001, .007, and .046, respectively). Metastases persisted in 1 or 2 LNs for 5 (20.0%) of 25 patients with ER?/HER2+ and for 4 (21.1%) of 19 patients with ER?/HER2?, and in 3 or more LNs for 0 (0%) of 25 patients with ER?/HER2+ and for 1 (5.3%) of 19 patients with ER?/HER2?. Patients with ER+ tumors had more numerous residual LN metastases than those with ER? tumors (P < .001). Among patients with ycN0, ypN status was not associated with regional recurrence-free survival or overall survival.ConclusionsThree or more residual LN metastases were rare in patients with ER? tumors if assessed as ycN0 by ultrasonography. Prospective studies are needed to confirm the prognostic impact of not performing axillary lymph node dissection in such patients.  相似文献   
7.
World Journal of Surgery - Preoperative nutritional status is considered to affect the short-term and long-term outcomes of cancer patients. The clinical value of the controlling nutritional status...  相似文献   
8.
Although rheumatologists, neurologists and dermatologists see patients with polymyositis (PM) and dermatomyositis (DM), their management appears to vary depending on the physician's specialty. The aim of the present study was to establish the treatment consensus among specialists of the three fields to standardize the patient care. We formed a research team supported by a grant from the Ministry of Health, Labor and Welfare, Japan. Clinical questions (CQ) on the management of PM and DM were raised. A published work search on CQ was performed primarily using PubMed. Using the nominal group technique, qualified studies and results in the published work were evaluated and discussed to reach consensus recommendations. They were sent out to the Japan College of Rheumatology, Japanese Society of Neurology and Japanese Dermatological Association for their approval. We reached a consensus in 23 CQ and made recommendations and a decision tree for management was proposed. They were officially approved by the three scientific societies. In conclusion, a multidisciplinary treatment consensus for the management of PM and DM was established for the first time.  相似文献   
9.
A 3‐month‐old boy developed small papules on his trunk. After the papules increased in number, the patient was diagnosed with Langerhans cell histiocytosis based on the pathological findings. He was referred to our department for further examination. Upon initial examination, the papules and nodules were scattered on his back, abdomen and lumbar region. Because he did not present with any organ involvement except the skin, he was diagnosed with single‐system and skin‐limited Langerhans cell histiocytosis. Skin rashes were treated with a topical steroid and started regressing 3 months after onset. All papules disappeared 6 months after onset. In this boy, the Langerhans cell histiocytosis tumor cells expressed phosphorylated extracellular signal‐regulated kinases. In Langerhans cell histiocytosis, BRAF V600E and other genes are known to mutate to act as driver mutations in stem cells of the myeloid dendritic cell lineage. Consequently, extracellular signal‐regulated kinases are continuously activated, which contributes to Langerhans cell histiocytosis carcinogenesis.  相似文献   
10.
We report a case of kerion celsi due to Trichophyton tonsurans. An 18‐year‐old male student judo practitioner had alopecic patches, black dots and subcutaneous abscesses on the right temporal region. The damaged hair represented endothrix infection with T. tonsurans, as assessed by mycological examinations. He was treated with oral itraconazole without any therapeutic effect, followed by terbinafine with good effect. A skin biopsy showed neutrophil, lymphocyte and histiocyte infiltration into the dermis and subcutaneous tissue with abscesses around a number of dilated hair follicles. Immunostaining showed that the expression level of human β‐defensin 2 (HBD‐2) was decreased in the epidermis of the alopecic and adjacent skin. Because interleukin (IL)‐17A generally induces HBD‐2 production by epidermal keratinocytes, we also immunohistochemically investigated IL‐17A expression. Unexpectedly, many IL‐17A‐bearing cells were found around destructed hair follicles, indicating that IL‐17A expression was not attenuated, but rather increased in the skin lesion. Our case suggests that IL‐17A‐upregulated antimicrobial peptide expression is disordered in kerion celsi, and severe inflammation with IL‐17A may cause tissue damage and resultant scar.  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