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   45239篇
  免费   2161篇
  国内免费   217篇
耳鼻咽喉   719篇
儿科学   834篇
妇产科学   765篇
基础医学   6016篇
口腔科学   1335篇
临床医学   3009篇
内科学   10682篇
皮肤病学   632篇
神经病学   3582篇
特种医学   1551篇
外科学   7999篇
综合类   177篇
一般理论   2篇
预防医学   1568篇
眼科学   689篇
药学   3762篇
中国医学   95篇
肿瘤学   4200篇
  2021年   708篇
  2020年   414篇
  2019年   575篇
  2018年   688篇
  2017年   540篇
  2016年   687篇
  2015年   727篇
  2014年   954篇
  2013年   1244篇
  2012年   1996篇
  2011年   2143篇
  2010年   1229篇
  2009年   1079篇
  2008年   2066篇
  2007年   2214篇
  2006年   2142篇
  2005年   2137篇
  2004年   2068篇
  2003年   2099篇
  2002年   2049篇
  2001年   1671篇
  2000年   1820篇
  1999年   1525篇
  1998年   510篇
  1997年   424篇
  1996年   370篇
  1995年   346篇
  1994年   325篇
  1993年   302篇
  1992年   1137篇
  1991年   962篇
  1990年   934篇
  1989年   961篇
  1988年   858篇
  1987年   849篇
  1986年   796篇
  1985年   787篇
  1984年   541篇
  1983年   437篇
  1982年   228篇
  1979年   485篇
  1978年   283篇
  1977年   259篇
  1975年   211篇
  1974年   225篇
  1973年   205篇
  1972年   206篇
  1971年   234篇
  1969年   231篇
  1968年   216篇
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
2.
BackgroundLocomotive syndrome is a condition of reduced mobility due to problems with locomotive organs. Although lumbar spinal canal stenosis is one of the major diseases constituting locomotive syndrome, only few studies have focused on the association between the two pathologies. We aimed to investigate the effect of surgery on lumbar spinal canal stenosis with respect to locomotive syndrome using various physical function tests, including locomotive syndrome risk tests, before and after surgery.MethodsClinical data of 101 consecutive patients (male = 46; female = 55; mean age, 69.3 years) who underwent surgery for lumbar spinal canal stenosis at our institute were prospectively collected. Results of physical function tests, including stand-up test, two-step test, and 25-Question Geriatric Locomotive Function Scale, and the sagittal vertical axis were evaluated before and 1 year after surgery. The association between several parameters and improvement of risk level in locomotive syndrome was evaluated.ResultsIn the total assessment, 93.1% of cases were in stage 2 and 6.9% in stage 1 preoperatively, while 72.4% were in stage 2, 22.4% in stage 1, and 5.2% in stage 0 at 1 year postoperatively. Postoperative improvement in the total assessment was observed in 28.7% of cases. Several physical function tests and sagittal vertical axis showed significant improvement after surgery. On multiple logistic regression analysis, age >75 years (odds ratio = 10.9, confidence interval = 1.09–109) and postoperative sagittal vertical axis >40 mm (odds ratio = 17.8, confidence interval = 1.78–177) were significant risk factors associated with non-improvement in risk level of locomotive syndrome.ConclusionsSurgical treatment for lumbar spinal canal stenosis improved physical function, including locomotive syndrome. Risk factors associated with non-improvement of locomotive syndrome were later-stage elderly and postoperative sagittal balance impairment.  相似文献   
3.
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   
4.

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   
5.
6.
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   
7.
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   
8.
Rescue therapy for gastrointestinal (GI) refractory bleeding, perforation, and fistula has traditionally required surgical interventions owing to the limited performance of conventional endoscopic instruments and techniques. An innovative clipping system, the over‐the‐scope clip (OTSC), may play an important role in rescue therapy. This innovative device is proposed as the final option in endoscopic treatment. The device presents several advantages including having a powerful sewing force for closure of GI defects using a simple mechanism and also having an innovative feature, whereby a large defect and fistula can be sealed using accessory forceps. Consequently, it is able to provide outstanding clinical effects for rescue therapy. This review clarifies the current status and limitations of OTSC according to different indications of GI refractory disease, including refractory bleeding, perforation, fistula, and anastomotic dehiscence. An extensive literature search identified studies reported 10 or more cases in which the OTSC system was applied. A total of 1517 cases described in 30 articles between 2010 and 2018 were retrieved. The clinical success rates and complications were calculated overall and for each indication. The average clinical success rate was 78% (n = 1517) overall, 85% for bleeding (n = 559), 85% (n = 351) for perforation, 52% (n = 388) for fistula, 66% (n = 97) for anastomotic dehiscence, and 95% (n = 122) for other conditions, respectively. The overall and severe OTSC‐associated complications were 1.7% (n = 23) and 0.59% (n = 9), respectively. This review concludes that the OTSC system may serve as a safe and productive device for GI refractory diseases, albeit with limited success for fistula.  相似文献   
9.
10.
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