全文获取类型
收费全文 | 71826篇 |
免费 | 6107篇 |
国内免费 | 225篇 |
专业分类
耳鼻咽喉 | 582篇 |
儿科学 | 2731篇 |
妇产科学 | 1938篇 |
基础医学 | 10384篇 |
口腔科学 | 1298篇 |
临床医学 | 9911篇 |
内科学 | 14478篇 |
皮肤病学 | 1426篇 |
神经病学 | 7226篇 |
特种医学 | 1693篇 |
外国民族医学 | 4篇 |
外科学 | 7032篇 |
综合类 | 574篇 |
一般理论 | 67篇 |
预防医学 | 8085篇 |
眼科学 | 1127篇 |
药学 | 4146篇 |
2篇 | |
中国医学 | 80篇 |
肿瘤学 | 5374篇 |
出版年
2023年 | 648篇 |
2022年 | 936篇 |
2021年 | 1985篇 |
2020年 | 1496篇 |
2019年 | 2192篇 |
2018年 | 2448篇 |
2017年 | 1910篇 |
2016年 | 2075篇 |
2015年 | 2188篇 |
2014年 | 2788篇 |
2013年 | 3990篇 |
2012年 | 5431篇 |
2011年 | 5440篇 |
2010年 | 3122篇 |
2009年 | 2798篇 |
2008年 | 4539篇 |
2007年 | 4613篇 |
2006年 | 4441篇 |
2005年 | 4175篇 |
2004年 | 4028篇 |
2003年 | 3643篇 |
2002年 | 3310篇 |
2001年 | 661篇 |
2000年 | 544篇 |
1999年 | 618篇 |
1998年 | 790篇 |
1997年 | 601篇 |
1996年 | 525篇 |
1995年 | 509篇 |
1994年 | 428篇 |
1993年 | 409篇 |
1992年 | 391篇 |
1991年 | 346篇 |
1990年 | 326篇 |
1989年 | 284篇 |
1988年 | 260篇 |
1987年 | 208篇 |
1986年 | 215篇 |
1985年 | 208篇 |
1984年 | 229篇 |
1983年 | 208篇 |
1982年 | 231篇 |
1981年 | 215篇 |
1980年 | 171篇 |
1979年 | 124篇 |
1978年 | 114篇 |
1977年 | 128篇 |
1976年 | 119篇 |
1974年 | 99篇 |
1973年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
Marie Thérèse Labro 《Clinical microbiology and infection》1996,1(S1):S24-S30
A brief overview is provided of the bioactivity of macrolides against a range of bacterial species. Topics considered include the cellular pharmacokinetics of uptake and efflux of these drugs and the importance of intra- or extracellular and cytoplasmic or granular location on their activity. Emphasis is placed on the importance of synergy between macrolides and host defenses, with drug accumulation producing modification of cellular function, such as enhancement of phagocytosis, and exocytosis of polymorphonuclear neutrophils. Such interaction may explain the activity of such agents against organisms which normally inhibit fusion of phagolysosomes. 相似文献
52.
Anne Hagemeijer Arjan Buijs Elizabeth Smit Bart Janssen Geert-Jan Creemers Dorien Van Der Plas Gerard Grosveld 《Genes, chromosomes & cancer》1993,8(4):237-245
Leukemic cells from two patients with Philadelphia-negative chronic myeloid leukemia (CML) were investigated: I) Cytogenetics showed a normal 46.XY karyotype in both cases, 2) molecular studies revealed rearrangement of the M-BCR region and formation of BCR-ABL fusion mRNA with b2a2 (patient I) or b3a2 (patient 2) configuration, and 3) fluorescence in situ hybridization (FISH) demonstrated relocation of the 5′ BCR sequences from one chromosome 22 to one chromosome 9. The ABL probe hybridized to both chromosomes 9 at band q34, while two other probes which map centromeric and telomeric of BCR on 22q 11 hybridized solely with chromosome 22. For the first time, a BCR-ABL rearrangement is shown to take place on 9q34 instead of in the usual location on 22q 11. A rearrangement in the latter site is found in all Ph-positive CML and in almost all investigated CML with variant Ph or Ph-negative, BCR-positive cases. The few aberrant chromosomal localizations of BCR-ABL recombinant genes found previously were apparently the result of complex and successive changes. Furthermore in patient 2, both chromosomes 9 showed positive FISH signals with both ABL and BCR probes. Restriction fragment length polymorphism (RFLP) analysis indicated that mitotic recombination had occurred on the long arm of chromosome 9 and that the rearranged chromosome 9 was of paternal origin. The leukemic cells of this patient showed a duplication of the BCR-ABL gene, analogous to duplication of the Ph chromosome in classic CML. In addition they had lost the maternal alleles of the 9q34 chromosomal region. The lymphocytes of patient 2 carried the maternal chromosome 9 alleles and were Ph-negative as evidenced by RFLP and FISH analyses, respectively. © 1993 Wiley-Liss, Inc. 相似文献
53.
Anne B. Fulton Ronald M. Hansen 《Documenta ophthalmologica. Advances in ophthalmology》1988,68(3-4):293-304
Scotopic b-wave stimulus/response (S/R) functions are abnormal in several human retinal degenerative disorders. However, the mechanisms by which diseases affect the S/R parameters are not yet fully known. Three experiments were done to simulate functional pathologies known to occur in retinal degenerations: 1) attenuated sensitivity of retinal units, 2) loss of rhodopsin, 3) loss of sensitivity with little or no loss of rhodopsin. None of the experimental perturbations of normal function replicated the pattern of S/R abnormalities caused by retinal degenerations. Thus, in the retinal degenerative disorders intrinsic abnormalities of cellular processing must affect the organization of distal retinal function indexed by the b-wave. 相似文献
54.
Marianne R. Freeman Wiley Mittenberg Marie Dicowden Maya Bat-Ami 《Brain injury : [BI]》1992,6(1):65-70
A controlled treatment outcome study was conducted comparing the efficacy of memory remediation treatment with no treatment on traumatic brain-injury patients. The memory remediation treatment consisted of both compensatory and executive training skills and was delivered 6 hours weekly over a 2 1/2-week period. Six subjects in the treatment group and 6 subjects in the control group were matched on WAIS-R FSIQ scores, pre-test memory scores and age. Pre-and post-test measures were obtained for both groups on a paragraph memory task. A significant difference was demonstrated between the treatment and control post-test memory scores. The experimental group significantly improved memory scores beyond that of the control group, suggesting that memory remediation is effective for head-injury patients with memory deficits. Discussion of findings and suggestions for further investigation are presented. 相似文献
55.
Martin E. Weinand Bruce Hermann Allen R. Wyler L. Philip Carter K. J. Oommen David Labiner Geoff Ahern Anne Herring 《Epilepsia》1994,35(5):1054-1059
Summary: We report a series of 8 patients with ictal déjà vu. Subdural strip electrocorticographic (ECoG) monitoring localized the ictal epileptogenic focus as follows: right (n = 6) and left (n = 2) mesiotemporal lobe. In all 8 patients, the left hemisphere was dominant for language function based on intracarotid amytal testing. In 6 right-handed patients, ictal déjà vu was associated with a right temporal lobe focus. However, in the 2 left-handed patients, the ictal focus was left temporal lobe. Although ictal déjà vu localizes the epileptic focus to temporal lobe, this experiential phenomenon appears to lateralize to the hemisphere nondominant for handedness. 相似文献
56.
Adele L Boskey David J Moore Michael Amling Ernesto Canalis Anne M Delany 《Journal of bone and mineral research》2003,18(6):1005-1011
Osteonectin function in bone was investigated by infrared analysis of bones from osteonectin-null (KO) and wildtype mice (four each at 11, 17, and 36 weeks). An increase in mineral content and crystallinity in newly formed KO bone and collagen maturity at all sites was found using FTIR microspectroscopy and imaging; consistent with osteonectin's postulated role in regulating bone formation and remodeling. Mineral and matrix properties of tibias of osteonectin-null mice and their age- and background-matched wildtype controls were compared using Fourier-transform infrared microspectroscopy (FTIRM) and infrared imaging (FTIRI) at 10- and 7-mm spatial resolution, respectively. The bones came from animals that were 11, 17, and 36 weeks of age. Individual FTIRM spectra were acquired from 20 x 20 microm areas, whereas 4096 simultaneous FTIRI spectra were acquired from 400 x 400 microm areas. The FTIRM data for mineral-to-matrix, mineral crystallinity, and collagen maturity were highly correlated with the FTIRI data in similar regions. In general, the osteonectin-null mice bones had higher mineral contents and greater crystallinity (crystal size and perfection) than the age-matched wildtype controls. Specifically, the mineral content of the newly forming periosteal bone was increased in the osteonectin-null mice; the crystallinity of the cortical bone was decreased in all but the oldest animals, relative to the wildtype. The most significant finding, however, was increased collagen maturity in both the cortical and trabecular bone of the osteonectin-null mice. These spectroscopic data are consistent with a mechanism of decreased bone formation and remodeling. 相似文献
57.
Danuta Wasserman Christer HellstrÖm Jerzy Wasserman Olof Beck Eva Andersson Marie Åsberg 《Archives of Suicide Research》1997,3(3):153-169
The aim of this study was to investigate markers of serotonin and immune function in suicidal patients. Cytotoxic activity of natural killer cells (NK) and CD16 lymphocytes were studied in 28 suicide attempters and 26 healthy controls, and related in patients to 5-hydroxyindoleacetic acid (5-HIAA) in cerebrospinal fluid (CSF). Patients with CSF 5-HIAA below the median had significantly lower NK cell activity than other patients. CD16 cell frequency was significantly lower in patients than in controls, and patients also tended to have lower NK cell cytotoxicity than healthy controls. There were no statistically significant correlations between 4-hydroxy-3methoxyphenyl glycol (HMPG), homovanillic acid (HVA), CSF cortisol and NK cell activity. The results support the hypothesis of compromised immune function in suicidal patients with evidence of disordered serotonin function. 相似文献
58.
Marie Biancuzzo 《分娩》1994,21(2):96-100
ABSTRACT: This case report describes a primipara who successfully breastfed 35-week-gestation twins for over six months. Positive interactions, research-based management strategies, and innovative problem solving helped her avoid the individual, interpersonal, and system factors that can injuence lactation failure. (BIRTH 21:2, June 1994) 相似文献
59.
OBJECTIVE: To describe the rationale, methodology, and general sample characteristics of the Canadian Psychiatric Association (CPA) practice profile survey, a national survey of psychiatrists and psychiatric practice. METHOD: Mail-in interviews were sent to all Canadian psychiatrists listed in their provincial registers and to all active CPA members (total = 3628). Respondents provided general information about their professional activities for one 24-hour day and detailed information for 1 randomly selected hour. Patient information--including sociodemographics, diagnostic profiles, functioning levels, risk of harm to self or others, and disposition--was elicited for 1 patient seen during the random hour as well as for the most seriously ill patient receiving clinical services that day. RESULTS: There was a 45.5% response rate. Questionnaires completed by nonpsychiatrists or with a large percentage of missing or incorrect data were eliminated (107 surveys), resulting in a final sample size of 1570. CPA members and those from Western Canada responded at a higher rate to the survey. The results suggest some cause for concern about future manpower shortages. Most psychiatrists practise eclectically, seeing patients across the life-span, and working in both community and institutional settings. The old and the young appear to be underserviced, compared with adults. CONCLUSIONS: This study represents an important step forward in evaluating the profile and activities of the profession. 相似文献
60.
Martine Visser Johan Marinus Anne M Stiggelbout Jacobus J Van Hilten 《Movement disorders》2004,19(11):1306-1312
We developed a questionnaire to assess autonomic symptoms in patients with Parkinson's disease (PD) and evaluated its reliability and validity. Based on the results of a postal survey in 46 PD patients, 21 multiple system atrophy patients, and 8 movement disorders specialists, items were included according to their frequency, burden, and clinical relevance. The questionnaire was evaluated in 140 PD patients and 100 controls, and test-retest reliability was established in a sample of 55 PD patients. The SCOPA-AUT consists of 25 items assessing the following regions: gastrointestinal (7), urinary (6), cardiovascular (3), thermoregulatory (4), pupillomotor (1), and sexual (2 items for men and 2 items for women) dysfunction. Test-retest reliability was good. Autonomic problems increased significantly with increasing disease severity for all autonomic regions, except sexual dysfunction. We conclude that SCOPA-AUT is a reliable and valid questionnaire that evaluates autonomic dysfunction in PD. 相似文献