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   40174篇
  免费   2299篇
  国内免费   112篇
耳鼻咽喉   466篇
儿科学   2347篇
妇产科学   887篇
基础医学   5177篇
口腔科学   891篇
临床医学   3285篇
内科学   7994篇
皮肤病学   958篇
神经病学   2237篇
特种医学   849篇
外科学   5365篇
综合类   1383篇
一般理论   17篇
预防医学   2718篇
眼科学   1573篇
药学   3683篇
中国医学   275篇
肿瘤学   2480篇
  2023年   257篇
  2022年   698篇
  2021年   1238篇
  2020年   685篇
  2019年   939篇
  2018年   1140篇
  2017年   792篇
  2016年   1054篇
  2015年   1094篇
  2014年   1491篇
  2013年   1959篇
  2012年   2688篇
  2011年   2746篇
  2010年   1540篇
  2009年   1372篇
  2008年   2026篇
  2007年   2036篇
  2006年   2067篇
  2005年   1643篇
  2004年   1686篇
  2003年   1420篇
  2002年   1272篇
  2001年   851篇
  2000年   883篇
  1999年   766篇
  1998年   366篇
  1997年   257篇
  1996年   275篇
  1995年   262篇
  1994年   219篇
  1993年   186篇
  1992年   521篇
  1991年   431篇
  1990年   454篇
  1989年   414篇
  1988年   379篇
  1987年   364篇
  1986年   369篇
  1985年   340篇
  1984年   298篇
  1983年   236篇
  1982年   165篇
  1979年   247篇
  1978年   167篇
  1977年   198篇
  1975年   177篇
  1974年   199篇
  1973年   187篇
  1972年   182篇
  1971年   170篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Gestational trophoblastic neoplasia (GTN) patients are treated according to the eight-variable International Federation of Gynaecology and Obstetrics (FIGO) scoring system, that aims to predict first-line single-agent chemotherapy resistance. FIGO is imperfect with one-third of low-risk patients developing disease resistance to first-line single-agent chemotherapy. We aimed to generate simplified models that improve upon FIGO. Logistic regression (LR) and multilayer perceptron (MLP) modelling (n = 4191) generated six models (M1-6). M1, all eight FIGO variables (scored data); M2, all eight FIGO variables (scored and raw data); M3, nonimaging variables (scored data); M4, nonimaging variables (scored and raw data); M5, imaging variables (scored data); and M6, pretreatment hCG (raw data) + imaging variables (scored data). Performance was compared to FIGO using true and false positive rates, positive and negative predictive values, diagnostic odds ratio, receiver operating characteristic (ROC) curves, Bland-Altman calibration plots, decision curve analysis and contingency tables. M1-6 were calibrated and outperformed FIGO on true positive rate and positive predictive value. Using LR and MLP, M1, M2 and M4 generated small improvements to the ROC curve and decision curve analysis. M3, M5 and M6 matched FIGO or performed less well. Compared to FIGO, most (excluding LR M4 and MLP M5) had significant discordance in patient classification (McNemar's test P < .05); 55-112 undertreated, 46-206 overtreated. Statistical modelling yielded only small gains over FIGO performance, arising through recategorisation of treatment-resistant patients, with a significant proportion of under/overtreatment as the available data have been used a priori to allocate primary chemotherapy. Streamlining FIGO should now be the focus.  相似文献   
2.
Colorectal cancer (CRC) is the third most diagnosed cancer and the second leading cause of cancer-related mortality in the United States. Across the globe, people in the age group older than 50 are at a higher risk of CRC. Genetic and environmental risk factors play a significant role in the development of CRC. If detected early, CRC is preventable and treatable. Currently, available screening methods and therapies for CRC treatment reduce the incidence rate among the population, but the micrometastasis of cancer may lead to recurrence. Therefore, the challenge is to develop an alternative therapy to overcome this complication. Nanotechnology plays a vital role in cancer treatment and offers targeted chemotherapies directly and selectively to cancer cells, with enhanced therapeutic efficacy. Additionally, nanotechnology elevates the chances of patient survival in comparison to traditional chemotherapies. The potential of nanoparticles includes that they may be used simultaneously for diagnosis and treatment. These exciting properties of nanoparticles have enticed researchers worldwide to unveil their use in early CRC detection and as effective treatment. This review discusses contemporary methods of CRC screening and therapies for CRC treatment, while the primary focus is on the theranostic approach of nanotechnology in CRC treatment and its prospects. In addition, this review aims to provide knowledge on the advancement of nanotechnology in CRC and as a starting point for researchers to think about new therapeutic approaches using nanotechnology.  相似文献   
3.
Sorsby fundus dystrophy (SFD), an autosomal dominant, fully penetrant, degenerative disease of the macula, is manifested by symptoms of night blindness or sudden loss of visual acuity, usually in the third to fourth decades of life due to choroidal neovascularization (CNV). SFD is caused by specific mutations in the Tissue Inhibitor of Metalloproteinase-3, (TIMP3) gene. The predominant histo-pathological feature in the eyes of patients with SFD are confluent 20–30 m thick, amorphous deposits found between the basement membrane of the retinal pigment epithelium (RPE) and the inner collagenous layer of Bruch's membrane. SFD is a rare disease but it has generated significant interest because it closely resembles the exudative or “wet” form of the more common age-related macular degeneration (AMD). In addition, in both SFD and AMD donor eyes, sub-retinal deposits have been shown to accumulate TIMP3 protein. Understanding the molecular functions of wild-type and mutant TIMP3 will provide significant insights into the patho-physiology of SFD and perhaps AMD. This review summarizes the current knowledge on TIMP3 and how mutations in TIMP3 cause SFD to provide insights into how we can study this disease going forward. Findings from these studies could have potential therapeutic implications for both SFD and AMD.  相似文献   
4.
5.
Haemophilia is a common cause of genetically inherited bleeding disorders. Pseudotumours occur in 1–2 % of persons with severe forms of haemophilia. These are a result of repeated haemorrhage into soft tissues, subperiosteum or a site of bone fracture with inadequate resorption of the extravasated blood. There are a number of therapeutic alternatives for this dangerous condition: surgical removal, percutaneous management, irradiation, embolization etc. In this case report, we describe the natural history, clinical course and successful surgical management of a patient with haemophilia who presented with a massive pseudotumour. We also briefly review the relevant literature on the various therapeutic modalities that have been implemented in the management of this rare complication. Though surgeons may be averse to operate on haemophiliacs, primary surgical management as done in our case may prove to be the definitive treatment option for such patients.  相似文献   
6.
7.
8.
9.

Background

Multiple myeloma (MM) is a hematologic malignancy of plasma cell origin. MM primarily affects bone marrow, but extramedullary sites can also be involved. Myelomatous pleural effusion (MPE) is an atypical and rare complication of MM. We aimed to systematically study the incidence and clinicopathologic profile of patients with MPE in a real-world setting.

Patients and Methods

In this retrospective study, 415 consecutive patients with MM managed at a tertiary care center in North India during a study period of January 1, 2010 to December 31, 2015 were evaluated for MPE. The patients with MPE were analyzed for their clinical profile, diagnosis, treatment, and outcomes.

Results

Of these 415 patients, 11 (2.65%) patients had MPE. The median age of the study population was 50 years with male preponderance. The majority of these patients had immunoglobin (Ig)G Kappa disease. All patients had higher than International Staging System stage I disease. MPE was a presenting feature at MM diagnosis in 45.45% (n = 5) of the patients, whereas the rest developed MPE during follow-up. MPE presented predominantly (81.8%) as a unilateral effusion. Concurrent extramedullary involvement at other site was seen in 45.45% (n = 5), with 3 (27%) patients having concurrent myelomatous ascites. Six of these were managed aggressively, whereas 5 patients opted for palliation. The outcomes were dismal (90.9% mortality), with a median survival of 2.47 months.

Conclusion

MPE is a rare entity, and positive outcomes of therapy remain low with dismal prognosis.  相似文献   
10.
Mirror movements are simultaneous, involuntary, identical movements occurring during contralateral voluntary movements. These movements are considered as soft neurologic signs seen uncommonly in clinical practice. The mirror movements are described in various neurological disorders which include parkinsonism, cranio veretebral junction anamolies, and hemiplegic cerebral palsy. These movements are intriguing and can pose significant disability. However, no such observation regarding mirror movements in progressive hemifacial atrophy have been reported previously. We are reporting a teenage girl suffering from progressive hemifacial atrophy and epilepsy with demonstrable mirror movements in hand.  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