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   10599篇
  免费   631篇
  国内免费   85篇
耳鼻咽喉   128篇
儿科学   293篇
妇产科学   337篇
基础医学   1250篇
口腔科学   283篇
临床医学   918篇
内科学   2423篇
皮肤病学   182篇
神经病学   450篇
特种医学   401篇
外国民族医学   1篇
外科学   1509篇
综合类   327篇
一般理论   7篇
预防医学   727篇
眼科学   349篇
药学   984篇
中国医学   106篇
肿瘤学   640篇
  2023年   139篇
  2022年   347篇
  2021年   467篇
  2020年   311篇
  2019年   405篇
  2018年   442篇
  2017年   317篇
  2016年   312篇
  2015年   286篇
  2014年   441篇
  2013年   551篇
  2012年   774篇
  2011年   784篇
  2010年   464篇
  2009年   366篇
  2008年   573篇
  2007年   586篇
  2006年   484篇
  2005年   456篇
  2004年   400篇
  2003年   335篇
  2002年   303篇
  2001年   153篇
  2000年   140篇
  1999年   144篇
  1998年   90篇
  1997年   69篇
  1996年   62篇
  1995年   60篇
  1994年   67篇
  1993年   41篇
  1992年   75篇
  1991年   67篇
  1990年   84篇
  1989年   70篇
  1988年   72篇
  1987年   66篇
  1986年   68篇
  1985年   49篇
  1984年   40篇
  1983年   25篇
  1982年   24篇
  1981年   20篇
  1980年   25篇
  1979年   32篇
  1977年   31篇
  1976年   23篇
  1973年   17篇
  1970年   19篇
  1969年   15篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Pilonidal disease is a disease of relatively young people, the exact aetiology of which is unknown. Treatment options vary from simple incision to complex flap procedures. Each method has its advocates and they all have a variable recurrence rate. The multiplicity of procedures testifies to the lack of an optimal treatment method. The objective of this study is to compare sinotomy, that is, simply laying the sinus open with the more popular radical surgery, where the sinus-bearing tissues are excised. Patients who were admitted to Aseer Central Hospital, Saudi Arabia with a pilonidal sinus or abscess, in the period from April 1999 to January 2005, were identified. The medical records were reviewed and data related to the patient characteristics, disease process and the procedures carried out were noted. Identified patients were contacted by phone to check recurrence of the disease and their abidance to instructions regarding regular hair removal from the area. Eighty-one patients were included in the study. The median age was 24.2 years (range 16-60 years). There were 9 women and 72 men. All procedures were carried out under general anaesthesia except sinotomy, which was carried out under general or local anaesthesia. The surgical procedure was incision and drainage of abscess in 16 cases (19.8%), excision with primary closure in 29 cases (35.8%), excision by the open method in 15 cases (18.5%), sinotomy in 14 cases (17.3%) and rhomboid flap construction in 8 cases (9.9%). The overall recurrence rate was 26.9%, and the mean hospital stay was 4.1 days. Sinotomy had a low recurrence rate (12.5%) and a short hospital stay (2.8 days). Sinotomy has the advantages of simplicity, the possibility of operating under local anaesthesia, with an acceptable recurrence rate. We recommend sinotomy for pilonidal sinus and abscess alike, both in primary and recurrent cases.  相似文献   
992.
Malignant melanoma is one of the most aggressive and invasive metastatic tumors derived from melanocytes that have undergone malignant transformation by acquisition of genetic and epigenetic alterations. Oligonucleotide microarray-based screening of distinct stages in the tumor progression model of cutaneous melanoma identified ASK/Dbf4, as a novel determinant for melanoma development. Quantitative real-time polymerase chain reaction-based confirmation of ASK/Dbf4 on a series of benign nevi, dysplastic nevi, primary cutaneous melanomas and cutaneous melanoma metastases; and a number of other controls using normal human melanocytes as calibrator not only revealed a melanoma-specific over-expression but also revealed that higher ASK/Dbf4-expressing melanomas were associated with lower relapse-free survival. Additionally, we also confirmed the observed over-expression of ASK/Dbf4 in melanoma using western blot analysis and immunohistochemistry. As ASK/Dbf4 is known to be a cyclin-like regulatory subunit of mammalian Cdc7 from the studies in yeast, the present study investigated its role in melanoma cells. In keeping with its expected role, our data suggest that up-regulated ASK/Dbf4 is localized in the nucleus and binds to human Cdc7 to form Cdc7-ASK/Dbf4 complexes in several analyzed melanoma cell lines. Further, we demonstrate that small interfering RNA-mediated depletion of ASK/Dbf4 retarded melanoma cell survival and proliferation. In summary, we report the differential regulation of a novel gene, namely ASK/Dbf4, in melanoma and suggest that up-regulation of ASK/Dbf4 is a novel molecular determinant with prognostic relevance that confers a proliferative advantage in cutaneous melanoma.  相似文献   
993.
994.
Trichoepithelioma (TE) is a benign tumor of follicular origin that presents as small, skin-colored papules predominantly on the face. When more than one family member is affected, the disease is known as multiple familial trichoepithelioma (MFT). It is a rare autosomal dominant (AD) skin disease. Malignant transformation is very rare. We present a case of MFT in a female patient and her father with malignant transformation to basal cell carcinoma (BCC) in the father. We summarized the main histological differential parameters between TE and BCC and applied immunophenotyping for both by administration of Bcl2, CD34, CD10 and androgen receptor (AR) antibodies.  相似文献   
995.
996.
Autozygosity mapping (AM) is a technique utilised for mapping homozygous autosomal recessive (AR) traits and facilitation of genetic diagnosis. We investigated the utility of AM for the molecular diagnosis of heterogeneous AR disorders, using epidermolysis bullosa (EB) as a paradigm. We applied this technique to a cohort of 46 distinct EB families using both short tandem repeat (STR) and genome‐wide single nucleotide polymorphism (SNP) array‐based AM to guide targeted Sanger sequencing of EB candidate genes. Initially, 39 of the 46 cases were diagnosed with homozygous mutations using this method. Independently, 26 cases, including the seven initially unresolved cases, were analysed with an EB‐targeted next‐generation sequencing (NGS) panel. NGS identified mutations in five additional cases, initially undiagnosed due to the presence of compound heterozygosity, deep intronic mutations or runs of homozygosity below the set threshold of 2 Mb, for a total yield of 44 of 46 cases (95.7%) diagnosed genetically.  相似文献   
997.
998.
Stroke is a serious life-threatening medical condition and is one of the principal reasons for death and disabilities worldwide. The aim of the present study was to determine the neuroprotective effects of hydroxychloroquine (HCQ) and the timing of its administration in cerebral ischemia/reperfusion (I/R) in rats. A global I/R model was used, and HCQ was administered in either pre- or post-treatment doses of 25 and 50 mg/kg. Effects of HCQ on infarct size, histological changes, oxidative stress, and learning and memory were evaluated. Phospho-AMPK and SQSTM1/p62 protein levels were also measured to elucidate the possible mechanisms involved. HCQ in both pre- (at doses of 25 and 50 mg/kg) or post-treatment (at a dose of 50 mg/kg) protocols reduces brain infarct size and histopathological changes and improves learning and memory after cerebral I/R. Pre-treatment with HCQ reduced AMPK activity with no significant effect on SQSTM1/p62 increment. Post-treatment with HCQ increased AMPK activity and SQSTM1/p62 protein levels. Our results show the neuroprotective effects of HCQ on cerebral I/R through the reduction in infarct size, histopathological changes, and improvement in memory and learning functions. Moreover, AMPK and autophagy may play a role in this protective effect.  相似文献   
999.

Objectives

To present a systematic review and critical analysis of clinical studies for necrotising otitis externa (NOE), with the aim of informing best practice for diagnosis and management.

Design

Medline, Embase, Cochrane Library and Web of Science were searched from database inception until 30 April 2021 for all clinical articles on NOE. The review was registered on PROSPERO (ID: CRD42020128957) and conducted in accordance with PRISMA guidelines.

Results

Seventy articles, including 2274 patients were included in the final synthesis. Seventy-three percent were retrospective case series; the remainder were of low methodological quality. Case definitions varied widely. Median patient age was 69.2 years; 68% were male, 84% had diabetes and 10% had no reported immunosuppressive risk factor. Otalgia was almost universal (96%), with granulation (69%) and oedema (76%) the commonest signs reported. Pseudomonas aeruginosa was isolated in 62%, but a range of bacterial and fungal pathogens were reported and 14% grew no organism. Optimal imaging modality for diagnosis or follow-up was unclear. Median antimicrobial therapy duration was 7.2 weeks, with no definitive evidence for optimal regimens. Twenty-one percent had surgery with widely variable timing, indication, or procedure. One-year disease-specific mortality was 2%; treatment failure and relapse rates were 22% and 7%, respectively.

Conclusion

There is a lack of robust, high-quality data to support best practice for diagnosis and management for this neglected condition. A minimum set of reporting requirements is proposed for future studies. A consensus case definition is urgently needed to facilitate high-quality research.  相似文献   
1000.
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