AChE inhibitionOther cholinesterasesPhysical propertiesLatency and toxicityPharmacological propertiesClinical manifestationsTreatmentPyridostigmineAtropinePralidoxime
  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   136343篇
  免费   9457篇
  国内免费   631篇
耳鼻咽喉   1652篇
儿科学   3424篇
妇产科学   2448篇
基础医学   17418篇
口腔科学   2913篇
临床医学   13342篇
内科学   28056篇
皮肤病学   1751篇
神经病学   12001篇
特种医学   5401篇
外科学   21842篇
综合类   1927篇
现状与发展   1篇
一般理论   173篇
预防医学   12443篇
眼科学   2916篇
药学   9689篇
  2篇
中国医学   179篇
肿瘤学   8853篇
  2023年   671篇
  2022年   1051篇
  2021年   2587篇
  2020年   1468篇
  2019年   2400篇
  2018年   2928篇
  2017年   2119篇
  2016年   2235篇
  2015年   2719篇
  2014年   4020篇
  2013年   6069篇
  2012年   8872篇
  2011年   9456篇
  2010年   5266篇
  2009年   4812篇
  2008年   8402篇
  2007年   9005篇
  2006年   8571篇
  2005年   8732篇
  2004年   8383篇
  2003年   7883篇
  2002年   7704篇
  2001年   1291篇
  2000年   1070篇
  1999年   1403篇
  1998年   1631篇
  1997年   1307篇
  1996年   1257篇
  1995年   1219篇
  1994年   1038篇
  1993年   1005篇
  1992年   840篇
  1991年   872篇
  1990年   762篇
  1989年   731篇
  1988年   757篇
  1987年   740篇
  1986年   764篇
  1985年   841篇
  1984年   909篇
  1983年   870篇
  1982年   1134篇
  1981年   1161篇
  1980年   967篇
  1979年   638篇
  1978年   671篇
  1977年   600篇
  1976年   524篇
  1975年   470篇
  1974年   480篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
OBJECTIVE: Tumors arising within augmentation cystoplasties are aggressive, have poor prognosis and the majority are not detected at follow-up cystoscopy. Genetic changes in tumors precede morphological abnormalities. Therefore, the aim of this study was to investigate whether genetic abnormalities detected by comparative genomic hybridization (CGH) could be used to identify those patients with augmentation cystoplasties at increased risk of tumorigenesis. METHODS: Bladder biopsy samples were obtained from 16 augmentation cystoplasty patients both distant from and near to the enterovesical anastomosis. CGH was used to detect genetic abnormalities in DNA extracted from the biopsies, archival specimens of two augmentation cystoplasties and two de novo bladder adenocarcinomas. RESULTS: A greater number of amplifications on 2p, 3q, 8q, 9p, 17p, 18pq and 20pq, were observed in bladder biopsies obtained near to the enterovesical anastomosis compared to those taken distant to the suture line. CGH of archival augmentation cystoplasty tumor DNA indicated abnormalities at several loci with amplifications at 2q, 5q, 10p and 21pq, while deletions occurred at 5p and 16p. CONCLUSIONS: The results of this study suggest that the urothelium adjacent to the bladder and/or bowel anastomosis in augmentation cystoplasties is genetically unstable. Furthermore, longitudinal studies are required to establish whether or not patients exhibiting genetic instability following augmentation cystoplasty are at greater risk of developing tumors than those with genetically stable epithelia.  相似文献   
62.
Clinical outcomes data can be used to facilitate patient management decisions, assess clinician and organizational performance, and to provide evidence for the effectiveness of surgery and rehabilitation. The validity of the inferences made from outcomes data are dependent on the validity of the outcomes measures themselves and the circumstances under which the data were collected, analyzed, and interpreted. Clinical outcomes may include measures of impairment of body structure and function, activity limitation, and participation restriction. However, because the relationship between impairment and the resulting activity limitation and participation restriction is not direct, and because activity limitations and participation restrictions are of the utmost concern to the athlete, the primary clinical outcome should be measures of activity limitation and participation restriction. Activity limitation and participation restriction may be measured either through direct observation of performance or by general or specific measures of health related quality of life. Clinical outcomes data must be collected systematically to ensure valid inferences from the data.  相似文献   
63.
The second part of this review addresses the treatment and prognosis of the vasculitides Wegener's granulomatosis, microscopic polyangiitis, Churg–Strauss syndrome and polyarteritis nodosa. Treatment regimens consist of an initial remission phase with aggressive immunosuppression, followed by a more prolonged maintenance phase using less toxic agents and doses. This review focuses on the initial treatment of fulminant vasculitis, the mainstay of which remains immunosuppression with steroids and cyclophosphamide. For Wegener's granulomatosis and microscopic polyangiitis plasma exchange can be considered for first-line therapy in patients with acute renal failure and/or pulmonary haemorrhage. Refractory disease is rare and is usually due to inadequate treatment. The vasculitides provide a particular challenge for the critical care team. Particular aspects of major organ support related to these conditions are discussed. Effective treatment has revolutionized the prognosis of these conditions. However, mortality is still approximately 50% for those requiring admission to intensive care unit. Furthermore, there is a high morbidity associated with both the diseases themselves and the treatment.  相似文献   
64.
Ultrasensitive bright field in situ hybridization assays using enzyme metallography (EnzMet) have been developed and validated, but little is known regarding the applicability of EnzMet for immunophenotypic detection of protein via IHC. Superior resolution via discrete metallographic deposits offers the potential for enhancing high-resolution immunophenotyping. Using high-complexity tissue microarrays (TMAs), 88 common solid tumors were evaluated by automated EnzMet (Nanoprobes and Ventana). Targets were chosen to assess the ability of EnzMet to specifically localize encoded antigens in the nucleus (estrogen receptor), cytoplasm (cytokeratins), and cytoplasmic membrane (HER2) in TMAs. Results were compared with conventional IHC diaminobenzidine (DAB) immunostaining. There was full concordance between the EnzMet and conventional IHC results. Furthermore, the EnzMet reaction products did not appreciably diffuse, were dense and sharply defined, and provided excellent high-resolution differentiation of cellular compartments in paraffin sections for the nuclear, cytoplasmic, and cell membrane-localized antigens evaluated. The higher density of elemental silver deposited during enzyme metallography permitted evaluation of core immunophenotypes at a relatively low magnification, allowing more tissue to be screened in an efficient manner. This preliminary study shows the utility of using enzyme metallography for high-resolution immunophenotyping in TMAs.  相似文献   
65.
A technique is presented which allows the rapid precise harvesting of split-skin grafts in rats. This technique uses the skin which would have been discarded in the formation of an open wound as a donor site thus reducing the overall assault on the animal.  相似文献   
66.
Background: Bupivacaine retards myocardial acidosis during ischemia. The authors measured function of rat isolated hearts after prolonged storage to determine whether bupivacaine improves cardiac protection compared with standard cardioplegia alone.

Methods: After measuring cardiac function on a Langendorff apparatus, hearts were perfused with cardioplegia alone (controls), cardioplegia containing 500 [mu]m bupivacaine, or cardioplegia containing 2 mm lidocaine; were stored at 4[degrees]C for 12 h; and were then reperfused. Heart rate and left ventricular developed pressures were measured for 60 min. Maximum positive rate of change in ventricular pressure, oxygen consumption, and lactate dehydrogenase release were also measured.

Results: All bupivacaine-treated, four of five lidocaine-treated, and no control hearts beat throughout the 60-min recovery period. Mean values of heart rate, left ventricular developed pressure, maximum positive rate of change in ventricular pressure, rate-pressure product, and efficiency in bupivacaine-treated hearts exceeded those of the control group (P < 0.001 at 60 min for all). Mean values of the lidocaine group were intermediate. Oxygen consumption of the control group exceeded the other groups early in recovery, but not at later times. Lactate dehydrogenase release from the bupivacaine group was less than that from the control group (P < 0.001) but did not differ from baseline.  相似文献   

67.
Geoghegan  James; Tong  Jeffrey L 《CEACCP》2006,6(6):230-234
The first 150 words of the full text of this article appear below. Key points
  • Chemical personal protective equipment must be wornwhen in contact with contaminated casualties.
  • Recognizing theclinical features of chemical warfare agent poisoning allowssupportive treatment and appropriate antidotes to be promptlyadministered.
  • The mnemonic DUMBELS describes the muscarinicfeatures of the nerve agent poisoning toxidrome.
  • There areeffective antidotes for poisoning with nerve agents, blood agents(metabolic poisons), botulinum toxin and kolokol-1.
  • There areno specific antidotes for blistering agents (vesicants) andchoking agents.
  Chemical warfare (CW) agents are chemical substances that havea direct toxic effect on plants, animals and humans. Classifiedaccording to their physiological effects, agents effective againsthumans include nerve agents, blistering agents (vesicants),blood agents, choking agents and toxins. Incapacitating, vomiting,psychoactive and riot control agents (e.g. CS gas) also exist.1 All personnel in contact with contaminated casualties must wearthe appropriate level of chemical personal protective equipment(CPPE) until adequate decontamination is . . . [Full Text of this Article]
   Nerve agents