全文获取类型
收费全文 | 299277篇 |
免费 | 8740篇 |
国内免费 | 1129篇 |
专业分类
耳鼻咽喉 | 3079篇 |
儿科学 | 8454篇 |
妇产科学 | 4878篇 |
基础医学 | 36603篇 |
口腔科学 | 4662篇 |
临床医学 | 24050篇 |
内科学 | 53037篇 |
皮肤病学 | 4705篇 |
神经病学 | 26566篇 |
特种医学 | 16055篇 |
外科学 | 44987篇 |
综合类 | 2830篇 |
现状与发展 | 3篇 |
一般理论 | 27篇 |
预防医学 | 24573篇 |
眼科学 | 5952篇 |
药学 | 20264篇 |
中国医学 | 2122篇 |
肿瘤学 | 26299篇 |
出版年
2023年 | 677篇 |
2022年 | 2697篇 |
2021年 | 4506篇 |
2020年 | 2159篇 |
2019年 | 3038篇 |
2018年 | 25150篇 |
2017年 | 19963篇 |
2016年 | 22945篇 |
2015年 | 6440篇 |
2014年 | 7382篇 |
2013年 | 8462篇 |
2012年 | 18225篇 |
2011年 | 31450篇 |
2010年 | 24636篇 |
2009年 | 16558篇 |
2008年 | 26682篇 |
2007年 | 28472篇 |
2006年 | 7058篇 |
2005年 | 8207篇 |
2004年 | 8595篇 |
2003年 | 8866篇 |
2002年 | 6403篇 |
2001年 | 3302篇 |
2000年 | 3209篇 |
1999年 | 2294篇 |
1998年 | 1114篇 |
1997年 | 877篇 |
1996年 | 599篇 |
1995年 | 558篇 |
1994年 | 487篇 |
1993年 | 392篇 |
1992年 | 789篇 |
1991年 | 782篇 |
1990年 | 761篇 |
1989年 | 632篇 |
1988年 | 517篇 |
1987年 | 505篇 |
1986年 | 359篇 |
1985年 | 398篇 |
1984年 | 283篇 |
1983年 | 212篇 |
1982年 | 161篇 |
1981年 | 168篇 |
1980年 | 168篇 |
1979年 | 224篇 |
1978年 | 170篇 |
1976年 | 144篇 |
1975年 | 125篇 |
1974年 | 159篇 |
1973年 | 122篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
921.
Shi Yong Ryu Chong-Kyo Lee Chong Ock Lee Hae Soo Kim Ok Pyo Zee 《Archives of pharmacal research》1992,15(3):242-245
Two triterpenes 1 and 2 with antiviral activity againstHerpes simplex virus type 1in vitro were isolated fromPrunella vulgaris. Each compound caused a significant reduction in viral cytopathic effect whenvero cells were exposed to them for 72 hours after viral challenge. They were identified asbetulinic acid(1) and 2α, 3α-dihydroxyurs-12-en-28-oic acid(2) on the basis of their spectroscopic properties. The antiviral activity of them was estimated as EC50=30 μg/ml(1) and 8 μg/ml(2), respectively by plaque reduction assay. 相似文献
922.
S. H. Kim J. W. Milsom J. M. Church K. A. Ludwig A. Garcia-Ruiz J. Okuda V. W. Fazio 《Surgical endoscopy》1997,11(10):1013-1016
Background: Because of the inability to palpate colonic tumors during laparoscopy, their location must be precisely identified before
resection is undertaken.
Method: A retrospective study was performed of 58 patients in order to be able to describe our methods of tumor localization for
laparoscopic colorectal operations and to review their effectiveness.
Results: In all patients, the entire colon was examined preoperatively by colonoscopy. In one patient, preoperative colonoscopic localization
was inaccurate. In 31 patients, tumors were easily detectable at surgery. In five patients with the tumor in the right colon,
even though the lesion was not detectable at surgery, right colectomy was performed without marking because preoperative colonoscopy
reliably identified the lesion adjacent to the ileocecal valve. Twenty-two patients required some type of procedure to localize
the tumor. The procedures and their problems were as follows: preoperative tattoo (five)—tattoo not visualized (one); intraoperative
colonoscopy alone (six), combined with intraoperative tattoo (four) or clip (three)—poor operative exposure due to bowel distension
(nine), hard to see the clip (three), dislodged clip (two), inadequate resection margin (one); intraoperative proctoscopy
alone (two), combined with laparoscopic stitch (two)—no problems. In no patient was tumor present at a resection line and
in no patient was the wrong segment resected.
Conclusions: Reliable preoperative identification of the tumor adjacent to the ileocecal valve can permit right colectomy without marking.
Lesions in the upper rectum can be approached via intraoperative proctoscopy ± suture placement. If the surgeon anticipates
intraoperative localization may be difficult, lesions other than rectal or cecal ones should probably be marked by preoperative
tattooing. Further studies regarding the technique of tattooing are warranted.
Received: 18 July 1996/Accepted: 10 March 1997 相似文献
923.
924.
925.
Numerous advances in technology have been made in the last several years in the diagnosis and treatment of the infertile man. Using case presentations, this article highlights these important new developments and reviews the basics of a comprehensive male infertility evaluation. The use of ultrasound as a critical, indispensable, yet noninvasive tool in the evaluation of possible male reproductive tract obstruction is discussed. Since assisted reproductive techniques (ARTs) have be come increasingly important in the management of the otherwise untreatable infertile man, specialized testing of sperm function, e.g., the sperm penetration assay (SPA), and strict morphology assessment are often useful prior to the initiation of some of these assisted reproductive procedures such as intrauterine insemination (IUI) or in vitro fertilization (IVF). Testicular touch preparation cytology and image analysis are also important additions to routine testicular biopsy for quantifying the extent of spermatogenesis. Finally, the revolutionary micromanipulation procedure of intracytoplasmic sperm injection (ICSI) has forever changed the practice of andrology by enabling men previously thought to be irreversibly infertile the chance to initiate their own biologic pregnancy. 相似文献
926.
Whether dyslipoproteinemias can be corrected with 24-day mountain therapy in a mid-mountainous area (the village of Malinovka, 1600 m above the sea-level) was studied in 225 males who had sustained large myocardial infarction. The posthospital rehabilitation of postinfarction patients in a mid-mountainous sanatorium caused a substantial change in blood lipoprotein composition, which were generally antiatherogenic. The antiatherogenic changes in blood lipoprotein composition retained within 10 months after their stay at the sanatorium, which indicates that mid-mountain climate is a promising tool for non-drug prevention and correction of atherogenic dyslipoproteinemias. 相似文献
927.
Julio A. Ramirez 《Disease Management & Health Outcomes》2003,11(1):33-43
Several national and international organizations have developed and published guidelines for the treatment of patients with community-acquired pneumonia (CAP). Guidelines from Europe, the US, Canada and Latin America classify patients in different groups based on the severity of pneumonia, site of care and presence of risk factors for resistant organisms. The initial antibacterial therapy is designed to cover only the likely organisms able to infect a particular group of patients. An evaluation of current guidelines indicates that there are significant similarities in regard to classification of patients and initial antibacterial therapy. One objective of this review is to present the clinician with a practical approach to antibacterial selection based on current published guidelines for CAP.Although most of the care recommended in guidelines is evidence-based and associated with better clinical outcomes and/or decreased healthcare cost, there is still a significant gap between recommended care and actual care of patients with CAP. Dissemination of guidelines at the local level has proved to have a minimal effect in changing local practices. To bring the local care of patients with CAP closer to the care recommended in guidelines, it is necessary to have an appropriate plan for guideline implementation. This review provides the clinician and other healthcare decision-makers with a methodology for implementation of national guidelines at the local hospital level. 相似文献
928.
Francesco Franceschi Umile Giuseppe Longo Laura Ruzzini Paolo Simoni Bruno Beomonte Zobel Vincenzo Denaro 《Knee surgery, sports traumatology, arthroscopy》2007,15(3):266-268
Bilateral discoid medial menisci is an extremely rare condition of the knee and it can be associated to other pathological
findings, including anterior portion cyst formation. We report on the clinical features, radiographic findings, treatment
and results of one patient who presented a bilateral medial discoid meniscus combined with posterior portion cyst of the left
knee. To the best of the author’s knowledge, this is the first case of bilateral medial discoid meniscus associated with posterior
portion cyst formation. 相似文献
929.
930.
Robert C Bast Hans Lilja Nicole Urban David L Rimm Herbert Fritsche Joe Gray Robert Veltri George Klee Andrew Allen Nam Kim Steven Gutman Mark A Rubin Andrew Hruszkewycz 《Clinical cancer research》2005,11(17):6103-6108
A group of investigators met at a Specialized Programs of Research Excellence Workshop to discuss key issues in the translation of biomarker discovery to the development of useful laboratory tests for cancer care. Development and approval of several new markers and technologies have provided informative examples that include more specific markers for prostate cancer, more sensitive tests for ovarian cancer, more objective analysis of tissue architecture and an earlier indication of response to treatment in breast cancer. Although there is no clear paradigm for biomarker development, several principles are clear. Marker development should be driven by clinical needs, including early cancer detection, accurate pretreatment staging, and prediction of response to treatment, as well as monitoring disease progression and response to therapy. Development of a national repository that uses carefully preserved, well-annotated tissue specimens will facilitate new marker development. Reference standards will be an essential component of this process. Both hospital-based and commercial laboratories can play a role in developing biomarkers from discovery to test validation. Partnering of academe and industry should occur throughout the process of biomarker development. The National Cancer Institute is in a unique position to bring together academe, industry, and the Food and Drug Administration to (a) define clinical needs for biomarkers by tumor type, (b) establish analytic and clinical paradigms for biomarker development, (c) discuss ways in which markers from different companies might be evaluated in combination, (d) establish computational methods to combine data from multiple biomarkers, (e) share information regarding promising markers developed in National Cancer Institute-supported programs, and (f) exchange data regarding new platforms and techniques that can accelerate marker development. 相似文献