全文获取类型
收费全文 | 33002篇 |
免费 | 2993篇 |
国内免费 | 126篇 |
专业分类
耳鼻咽喉 | 332篇 |
儿科学 | 1100篇 |
妇产科学 | 647篇 |
基础医学 | 4591篇 |
口腔科学 | 427篇 |
临床医学 | 3905篇 |
内科学 | 7188篇 |
皮肤病学 | 762篇 |
神经病学 | 3461篇 |
特种医学 | 1043篇 |
外国民族医学 | 1篇 |
外科学 | 4997篇 |
综合类 | 239篇 |
一般理论 | 29篇 |
预防医学 | 2805篇 |
眼科学 | 392篇 |
药学 | 1893篇 |
中国医学 | 66篇 |
肿瘤学 | 2243篇 |
出版年
2023年 | 113篇 |
2022年 | 237篇 |
2021年 | 564篇 |
2020年 | 484篇 |
2019年 | 869篇 |
2018年 | 976篇 |
2017年 | 803篇 |
2016年 | 821篇 |
2015年 | 1014篇 |
2014年 | 1240篇 |
2013年 | 1724篇 |
2012年 | 2036篇 |
2011年 | 2243篇 |
2010年 | 1438篇 |
2009年 | 1315篇 |
2008年 | 1957篇 |
2007年 | 2021篇 |
2006年 | 1974篇 |
2005年 | 2034篇 |
2004年 | 1949篇 |
2003年 | 1977篇 |
2002年 | 2026篇 |
2001年 | 358篇 |
2000年 | 307篇 |
1999年 | 361篇 |
1998年 | 402篇 |
1997年 | 376篇 |
1996年 | 295篇 |
1995年 | 336篇 |
1994年 | 278篇 |
1993年 | 262篇 |
1992年 | 201篇 |
1991年 | 208篇 |
1990年 | 173篇 |
1989年 | 150篇 |
1988年 | 165篇 |
1987年 | 170篇 |
1986年 | 149篇 |
1985年 | 144篇 |
1984年 | 156篇 |
1983年 | 125篇 |
1982年 | 176篇 |
1981年 | 175篇 |
1980年 | 155篇 |
1979年 | 96篇 |
1978年 | 103篇 |
1977年 | 92篇 |
1976年 | 74篇 |
1975年 | 64篇 |
1972年 | 67篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Pushparany Chanmugathas Jean -Marc Bollag 《Archives of environmental contamination and toxicology》1988,17(2):229-237
An acid sandy loam soil was used in a column study to determine the effect of microorganisms on Cd mobilization in soil and its speciation in column leachates. Non-sterile and sterile (gamma-irradiated) soil columns were initially treated with 90 mg of Cd (NO3)2, and approximately 20 mg of added Cd was retained in the soil. Soil columns were subsequently eluted with a sterile nutrient medium for a period of up to 38 days. Non-sterile and sterile soil columns leached with sterile deionized water served as unsupplemented controls. During a leaching period of 38 days, about 36% of the sorbed Cd in soil was mobilized in the presence of microorganisms and nutrients, while less than 16% of the Cd was released from the sterile and unsupplemented soil controls. To characterize the chemical form of the microbially mobilized Cd, the leachates were analyzed by gel filtration chromatography. In this study, 86% to 93% of the mobilized Cd was associated with the low molecular weight inorganic and organic fraction, while the remainder was eluted in the high molecular weight range. The low molecular weight Cd fractions were further examined by solid phase extraction (C18 Sep-Pak), and cation-exchange chromatography. From the various analyses, it was concluded that a significant amount of Cd existed as a hydrophilic organic complex, and the remainder as cationic Cd. Soil microorganisms were mostly responsible for the transformation of Cd in soil and its subsequent mobilization. 相似文献
32.
Joyce J. Fitzpatrick Sheila Ryan DeWitt Baldwin Roger Bulger Jean Johnson-Pawlson Christopher McLaughlin Maureen Kelley Leopold Selketr Bernardine Lacey Charlene Hanson Robin Harvan Patricia Hinton Walker David Sluyter Mary Joan Ladden Neal Vanselow 《Journal of Midwifery & Women's Health》1998,43(1):61-65
In 1995, the National League for Nursing commissioned a Panel on Interdisciplinary/Transdisciplinary Education. The focus of the Panel's work was to examine educational issues that transcend the health professions and to make recommendations for future implementation of an interdisciplinary approach to addressing them. This article is being simultaneously published by several professional journals. The goal is to seek as much feedback as possible. 相似文献
33.
G. Lallement Didier Clarençon Catherine Masqueliez Dominique Baubichon Monique Galonnier Marie-France Burckhart Michel Peoc’h Jean Claude Mestries 《Archives of toxicology》1997,72(2):84-92
Organophosphorus nerve agents are still in use today in warfare and as terrorism compounds. Classical emergency treatment
of organophosphate poisoning includes the combined administration of a cholinesterase reactivator (an oxime), a muscarinic
cholinergic receptor antagonist (atropine) and a benzodiazepine anticonvulsant (diazepam). However, recent experiments with
primates have demonstrated that such treatment, even when administered immediately after organophosphate exposure, does not
rapidly restore normal electroencephalographic (EEG) activity and fails to totally prevent neuronal brain damage. The objective
of this study was to evaluate, in a realistic setting, the therapeutic benefit of administration of GK-11 (gacyclidine), an
antiglutamatergic compound, as a complement to the available emergency therapy against organophosphate poisoning. GK-11 was
injected at a dose of 0.1 mg/kg (i.v) after a 45-min latency period to heavily intoxicated (8 LD50) primates. Just after intoxication, man-equivalent doses of one autoinjector containing atropine/pralidoxime/diazepam were
administered. The effects of GK-11 were examined on survival, EEG activity, signs of toxicity, recovery after challenge and
central nervous system histology. The present data demonstrate that treatment with GK-11 prevents the mortality observed after
early administration of classical emergency medication alone. EEG recordings and clinical observations also revealed that
GK-11 prevented soman-induced seizures and motor convulsions. EEG analysis within the classical frequency bands (beta, theta,
alpha, delta) demonstrated that central activity was totally restored to normal after GK-11 treatment, but remained profoundly
altered in animals receiving atropine/pralidoxime/diazepam alone. GK-11 also markedly accelerated clinical recovery of soman-challenged
primates. Lastly, this drug totally prevented the neuropathology observed 3 weeks after soman exposure in animals treated
with classical emergency treatment alone. GK-11 represents a promising adjuvant therapy to the currently available emergency
polymedication to ensure optimal management of organophosphate poisoning in man. This drug is presently being evaluated in
a human clinical trial for a different neuroprotective indication.
Received: 16 June 1997 / Accepted: 23 September 1997 相似文献
34.
Yawata Ayumi; Kanzaki Akio; Gilsanz Florinda; Delaunay Jean; Yawata Yoshihito 《Blood》1997,90(6):2471-2481
35.
Gail Pairitz Jarvik Terri H. Beaty Paul R. Gallagher Paul M. Coates Jean A. Cortner 《Genetic epidemiology》1993,10(4):257-270
A sample enriched for familial combined hyperlipidemia (FCHL) was examined for evidence of an association between genotype at an apolipoprotein B (apoB) elevating locus defined by complex segregation analysis and FCHL. Complex segregation analysis detected a locus with a large effect on plasma apoB levels and was used to compute the most probable genotype of family members. None of the 35 normolipidemic adults carried a copy of the allele associated with elevated apoB levels, yet 58% of the 109 adults with FCHL carried 1 (29%) or 2 (28%) copies. Two of 28 (7%) normal children had 1 copy of this allele and none had 2 copies, while 88 of 182 (48%) children with FCHL had 1 (26%) or 2 (22%) copies. Further, 4l of 48 (85%) individuals classified as having hyperapobetalipoproteinemia did not carry a copy of this “elevated apoB” allele. Therefore, the presence of the allele associated with elevation of apoB level is highly predictive of FCHL and this association cannot be explained solely by the presence of elevated apoB levels in FCHL, suggesting that the locus controlling apoB levels may play an etiologic role in FCHL. © 1993 Wiley-Liss, Inc. 相似文献
36.
Jean Addington Chrystal Mansley Donald Addington 《Revue canadienne de psychiatrie》2003,48(4):272-276
OBJECTIVE: To examine the extent of weight gain in the first year of treatment in an early psychosis program. METHOD: Subjects were 114 individuals who had experienced a first episode of psychosis and had completed 1 year in a comprehensive first-episode program. Weight and body mass index were calculated on entry to the program and at 6 and 12 months. Most of the subjects were all being prescribed second-generation antipsychotics. RESULTS: Significant increases in mean weight were observed in these young individuals over the course of the first year of treatment. CONCLUSIONS: If we are to work toward optimum treatment for first-episode subjects then potential weight gain needs to be addressed at the beginning of treatment and monitored during treatment. 相似文献
37.
Hsiu Hui Chiu Hsiao Hui Chou Wen Dar Jean Wung Yang Shieh 《Journal of microbiology, immunology, and infection》2007,40(1):14-23
BACKGROUND AND PURPOSE: Marine luminous bacteria were isolated and identified from samples in shallow coastal waters of Taiwan during the relatively warm seasons. METHODS: Identification of the luminous isolates was performed based on differences of phenotypic and genotypic characteristics together with data from phylogenetic analysis. RESULTS: Twenty seven strains of marine luminous bacteria were isolated. They were divided into five types based on differences of phenotypic characteristics. However, they could be clustered into only two genotypes according to the analysis of restriction patterns of polymerase chain reaction-amplified 16S rRNA genes digested with various restriction enzymes. The characterization data together with the 16S rRNA gene-based phylogenetic analysis revealed that the isolates included in phenotype I (seven isolates) could be Photobacterium leiognathi, and those included in phenotypes II-V (twenty isolates) might be classified as Vibrio harveyi. However, phylogeny based on gyrB sequences indicated that phenotypes II-V could be classified into two species, V. harveyi and Vibrio campbellii. CONCLUSION: Culturable luminous bacteria in the shallow coastal waters of Taiwan during the sampling period are dominated by V. harveyi/campbellii and P. leiognathi, and the former species appeared to be more prevalent and numerous than the latter species in general. 相似文献
38.
39.
Mathieu Beaulieu David Williamson Gilbert Pichette Jean Lachaine 《Infection control and hospital epidemiology》2007,28(11):1305-1307
Our study was conducted to determine whether use of gastric acid-suppressive agents increased the risk of Clostridium difficile-associated disease (CDAD) in a medical intensive care unit of one of the first hospitals to be threatened by the current CDAD epidemic in Quebec, Canada. Our findings suggest that efforts to determine risk factors for CDAD should focus on other areas, such as older age and antibiotic use. 相似文献
40.
Presence of specific 11C-meta-Hydroxyephedrine retention in heart, lung, pancreas, and brown adipose tissue. 总被引:1,自引:0,他引:1
(11)C-meta-Hydroxyephedrine (HED) is used in cardiac PET as an index of norepinephrine (NE) reuptake transporter (NET) density and synaptic NE levels. Whereas cardiac uptake is well documented, tracer retention in other tissues with rich noradrenergic innervation is unclear. Dysfunctional sympathetic nervous system (SNS) function in extracardiac metabolic storage tissues (i.e., adipose tissue and skeletal muscle) and endocrine organs contributes to several disorders. The aim of this study was to determine the potential of HED as an index of NE function in brown adipose tissue, lung, pancreas, skeletal muscle, and kidney by identifying NET-specific retention and determining the presence of radiolabeled metabolites. METHODS: Male Sprague-Dawley rats were administered HED and sacrificed at 30 min after tracer injection. Tissues were rapidly excised and counted for radioactivity, and relative tracer retention was quantified. Pretreatment with NET inhibitors established specific HED accumulation. The effect of elevated NE was tested by subcutaneous minipump NE infusion or inhibition of monoamine oxidase. Column-switch high-performance liquid chromatography (HPLC) was used to analyze the presence of radiolabeled metabolites in heart, brown adipose tissue, pancreas, and plasma. RESULTS: NET-specific retention was observed in heart, brown adipose tissue, lung, and pancreas but not in liver, skeletal muscle, or kidney. A dose-dependent response of HED accumulation to treatments elevating NE levels was established in tissues exhibiting specific uptake. At 30 min after tracer administration, HPLC analysis revealed 93%-95% of total radioactivity signal derived from unchanged HED in heart, pancreas, and brown adipose tissue compared with 61% +/- 8% unchanged HED in plasma. CONCLUSION: In addition to the heart, lung, pancreas, and brown adipose tissue exhibit specific and NE-responsive uptake of HED, supporting the potential for novel PET studies of SNS integrity in these tissues. 相似文献