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   2615篇
  免费   194篇
  国内免费   7篇
耳鼻咽喉   21篇
儿科学   107篇
妇产科学   31篇
基础医学   286篇
口腔科学   50篇
临床医学   210篇
内科学   711篇
皮肤病学   75篇
神经病学   141篇
特种医学   119篇
外科学   392篇
综合类   100篇
一般理论   1篇
预防医学   135篇
眼科学   55篇
药学   207篇
中国医学   12篇
肿瘤学   163篇
  2022年   19篇
  2021年   52篇
  2020年   24篇
  2019年   41篇
  2018年   42篇
  2017年   39篇
  2016年   49篇
  2015年   55篇
  2014年   60篇
  2013年   79篇
  2012年   122篇
  2011年   152篇
  2010年   71篇
  2009年   78篇
  2008年   98篇
  2007年   111篇
  2006年   104篇
  2005年   97篇
  2004年   92篇
  2003年   69篇
  2002年   62篇
  2001年   58篇
  2000年   81篇
  1999年   53篇
  1998年   34篇
  1997年   31篇
  1996年   23篇
  1995年   26篇
  1994年   17篇
  1992年   80篇
  1991年   39篇
  1990年   53篇
  1989年   39篇
  1988年   47篇
  1987年   45篇
  1986年   36篇
  1985年   37篇
  1984年   27篇
  1983年   17篇
  1982年   18篇
  1979年   41篇
  1978年   24篇
  1977年   26篇
  1975年   23篇
  1974年   26篇
  1973年   37篇
  1972年   32篇
  1971年   22篇
  1970年   20篇
  1935年   16篇
排序方式: 共有2816条查询结果,搜索用时 859 毫秒
81.
Mucormycosis of the gastrointestinal tract is a rare infection that usually occurs in patients who are immunocompromised and carries a high mortality. We report four cases of gastrointestinal mucormycosis seen over a one year period with different presentations, risk factors and different anatomical sites of involvement. A preoperative diagnosis was made only in one patient. All underwent surgery, three survived and one died postoperatively from multiorgan failure.  相似文献   
82.
83.
Biologic disease modifying anti-rheumatic drugs (DMARD) have revolutionized the management of several rheumatic disorders, especially those with autoimmune inflammatory etiology. A decade of experience has further endorsed their efficacy and unraveled safety issues. Treat to target remission is the current mantra. Infections remain the single most important complication. However, the access to biologics has been severely restricted by their exorbitant cost. Several biologics will lose their patent in the imminent future. An exact replica of a protein molecule is difficult if not impossible. Molecules seemingly similar to biologics called biosimilars or ‘follow on biologics’ are likely to flood the markets world wide at a challenging and affordable price. However, the acceptability of biosimilars will be driven by several contentious issues connected with manufacture, standardization, extent of validation (compared to source innovator biologic), interchangeability (with biologic), regulatory issues, and other patient centric socioeconomic issues. India is likely to provide a fertile field for biosimilar drugs and patients stand to gain from an expanded access and newer treatment paradigms. The fierce competition between several pharmaceutical companies (Indian and multinationals) to gain supremacy will fuel better affordability, equity and access to medicine while upholding the science of quality drugs. The stage is now set for this next big revolution in therapeutics.  相似文献   
84.

Background

Ventriculoperitoneal shunt (VPS) surgery is the most common procedure performed for the treatment of hydrocephalus. Erosive bladder perforation by a peritoneal catheter is an extremely rare complication of VPS. Only ten cases involving the normal (non-augmented) urinary bladder have been reported so far.

Case

We report a case of erosive bladder perforation, intra-corporeal knot formation, and perurethral extrusion of the distal end of VPS. This is the second only case report so far in the world literature showing triad of uncommon VPS complications in a single patient.

Conclusion

Prompt management could avoid further complications. Patient’s parents should be aware about this rare complication, so that they can seek timely medical help.  相似文献   
85.
Dental caries is the most common disease to cause irreversible damage in humans. Several therapeutic agents are available to treat or prevent dental caries, but none besides fluoride has significantly influenced the disease burden globally. Etiologic mechanisms of the mutans group streptococci and specific Lactobacillus species have been characterized to various degrees of detail, from identification of physiologic processes to specific proteins. Here, we analyze the entire Streptococcus mutans proteome for potential drug targets by investigating their uniqueness with respect to non-cariogenic dental plaque bacteria, quality of protein structure models, and the likelihood of finding a drug for the active site. Our results suggest specific targets for rational drug discovery, including 15 known virulence factors, 16 proteins for which crystallographic structures are available, and 84 previously uncharacterized proteins, with various levels of similarity to homologs in dental plaque bacteria. This analysis provides a map to streamline the process of clinical development of effective multispecies pharmacologic interventions for dental caries.  相似文献   
86.
A facile method was developed for the synthesis of quinazolinone derivatives in a one-pot condensation reaction via in situ amine generation using ammonia as the amine source and with the formation of four new C–N bonds in good to excellent yields. With the optimised method, we synthesized a library of piperazine linked quinazoline derivatives and the synthesized compounds were evaluated for their inhibitory activity against Mycobacterium tuberculosis. The compounds 8b, 8e, 8f, 8m, 8n and 8v showed potent anti-mycobacterial activity with MIC values of 2–16 μg mL−1. All the synthesized compounds follow Lipinski''s rules for drug likeness.

A facile method was developed for the synthesis of quinazolinone derivatives in a one-pot condensation reaction via in situ amine generation using ammonia as the amine source and with the formation of four new C–N bonds in good to excellent yields.  相似文献   
87.
88.
Introduction: Numerous biomarkers have been evaluated for the diagnosis, assessment of disease activity, prognosis, and response to treatment in sarcoidosis. In this report, we discuss the clinical and research utility of several biomarkers used to evaluate sarcoidosis.

Areas covered: The sarcoidosis biomarkers discussed include serologic tests, imaging studies, identification of inflammatory cells and genetic analyses. Literature was obtained from medical databases including PubMed and Web of Science.

Expert commentary: Most of the biomarkers examined in sarcoidosis are not adequately specific or sensitive to be used in isolation to make clinical decisions. However, several sarcoidosis biomarkers have an important role in the clinical management of sarcoidosis when they are coupled with clinical data including the results of other biomarkers.  相似文献   

89.
Dutch-belted and New Zealand White rabbits were passively immunized with AVP-21D9, a human monoclonal antibody to protective antigen (PA), at the time of Bacillus anthracis spore challenge using either nasal instillation or aerosol challenge techniques. AVP-21D9 (10 mg/kg) completely protected both rabbit strains against lethal infection with Bacillus anthracis Ames spores, regardless of the inoculation method. Further, all but one of the passively immunized animals (23/24) were completely resistant to rechallenge with spores by either respiratory challenge method at 5 weeks after primary challenge. Analysis of the sera at 5 weeks after primary challenge showed that residual human anti-PA levels decreased by 85 to 95%, but low titers of rabbit-specific anti-PA titers were also measured. Both sources of anti-PA could have contributed to protection from rechallenge. In a subsequent study, bacteriological and histopathology analyses revealed that B. anthracis disseminated to the bloodstream in some na?ve animals as early as 24 h postchallenge and increased in frequency with time. AVP-21D9 significantly reduced the dissemination of the bacteria to the bloodstream and to various organs following infection. Examination of tissue sections from infected control animals, stained with hematoxylin-eosin and the Gram stain, showed edema and/or hemorrhage in the lungs and the presence of bacteria in mediastinal lymph nodes, with necrosis and inflammation. Tissue sections from infected rabbits dosed with AVP-21D9 appeared comparable to corresponding tissues from uninfected animals despite lethal challenge with B. anthracis Ames spores. Concomitant treatment with AVP-21D9 at the time of challenge conferred complete protection in the rabbit inhalation anthrax model. Early treatment increased the efficacy progressively and in a dose-dependent manner. Thus, AVP-21D9 could offer an adjunct or alternative clinical treatment regimen against inhalation anthrax.  相似文献   
90.
This article reviews theoretical and practical approaches for setting priorities in global child health research investments. It also provides an overview of previous attempts to develop appropriate tools and methodologies to define priorities in health research investments. A brief review of the most important theoretical concepts that should govern priority setting processes is undertaken, showing how different perspectives, such as medical, economical, legal, ethical, social, political, rational, philosophical, stakeholder driven, and others will necessarily conflict each other in determining priorities. We specially address present research agenda in global child health today and how it relates to United Nation's (UN) Millennium Development Goal 4, which is to reduce child mortality by two-thirds between 1990 and 2015. The outcomes of these former approaches are evaluated and their benefits and shortcomings presented. The case for a new methodology for setting priorities in health research investments is presented, as proposed by Child Health and Nutrition Research Initiative, and a need for its implementation in global child health is outlined. A transdisciplinary approach is needed to address all the perspectives from which investments into health research can be seen as priorities. This prioritization requires a process that is transparent, systematic, and that would take into account many perspectives and build on advantages of previous approaches.  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