全文获取类型
收费全文 | 12381篇 |
免费 | 1279篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 109篇 |
儿科学 | 349篇 |
妇产科学 | 259篇 |
基础医学 | 1685篇 |
口腔科学 | 222篇 |
临床医学 | 1599篇 |
内科学 | 2629篇 |
皮肤病学 | 142篇 |
神经病学 | 1284篇 |
特种医学 | 377篇 |
外国民族医学 | 1篇 |
外科学 | 1451篇 |
综合类 | 331篇 |
一般理论 | 9篇 |
预防医学 | 1319篇 |
眼科学 | 221篇 |
药学 | 981篇 |
中国医学 | 11篇 |
肿瘤学 | 703篇 |
出版年
2021年 | 174篇 |
2020年 | 107篇 |
2019年 | 190篇 |
2018年 | 176篇 |
2017年 | 150篇 |
2016年 | 154篇 |
2015年 | 196篇 |
2014年 | 251篇 |
2013年 | 396篇 |
2012年 | 499篇 |
2011年 | 508篇 |
2010年 | 298篇 |
2009年 | 290篇 |
2008年 | 437篇 |
2007年 | 540篇 |
2006年 | 521篇 |
2005年 | 513篇 |
2004年 | 455篇 |
2003年 | 474篇 |
2002年 | 452篇 |
2001年 | 433篇 |
2000年 | 458篇 |
1999年 | 416篇 |
1998年 | 163篇 |
1997年 | 145篇 |
1996年 | 146篇 |
1995年 | 135篇 |
1994年 | 149篇 |
1993年 | 131篇 |
1992年 | 325篇 |
1991年 | 323篇 |
1990年 | 254篇 |
1989年 | 256篇 |
1988年 | 257篇 |
1987年 | 257篇 |
1986年 | 237篇 |
1985年 | 215篇 |
1984年 | 191篇 |
1983年 | 174篇 |
1982年 | 128篇 |
1981年 | 110篇 |
1979年 | 163篇 |
1978年 | 152篇 |
1977年 | 105篇 |
1976年 | 130篇 |
1975年 | 101篇 |
1974年 | 130篇 |
1973年 | 169篇 |
1972年 | 118篇 |
1968年 | 104篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
101.
G Land J Burke C Shelby J Rhodes J Collett I Bennett J Johnson 《Journal of clinical microbiology》1996,34(9):2300-2303
A screening test has been developed for the presumptive identification of Torulopsis (Candida) glabrata from other common clinical isolates of yeast-like fungi. An interlaboratory comparison of a protocol consisting of morphology on cornmeal Tween 80 agar and trehalose fermentation at 42 degrees C was successful in differentiating T. glabrata from other taxa that are frequent or possible clinical isolates. The screening results for 517 clinical yeast isolates, 241 of which were T. glabrata, were compared with their final identification via commercial systems (API20C Yeast Identification System [bioMERIEUX, Hazelwood, Mo.] and Rapid Yeast Identification Panel [Dade Microscan, Sacramento, Calif.]). The trehalose screening test has a sensitivity and a specificity of 97.8 and 95.8%, respectively, and a positive predictive value of 97.4% and a negative predictive value of 96.5%. Overall, the trehalose screen had an efficiency rating of 93.9% for ruling in or out T. glabrata. Since T. glabrata represents a substantial part of the workload in a clinical laboratory, a significant reduction in direct and indirect costs should be realized. 相似文献
102.
Evaluation of a latex agglutination test for Clostridium difficile in two nursing home outbreaks. 总被引:1,自引:3,他引:1 下载免费PDF全文
R G Bennett B E Laughon L M Mundy L D Bobo C A Gaydos W B Greenough rd J G Bartlett 《Journal of clinical microbiology》1989,27(5):889-893
The Culturette Brand Clostridium difficile test (CDT; Marion Laboratories, Inc., Kansas City, Mo.) is a latex agglutination test for C. difficile. The recent controversy involving the identity of antigens detected by CDT has made decisions on its use difficult. We compared the test results with those of selective culture and stool cytotoxin assays in investigations of two nursing home outbreaks of C. difficile-associated disease in order to formulate usage recommendations. Selective culture for C. difficile identified 27 (19%) of 142 subjects as carriers. CDT and the stool cytotoxin assay identified only 52 and 48% of these carriers, respectively. Compared with the stool cytotoxin assay, CDT had a high sensitivity (92%) and specificity (89%) for the detection of C. difficile disease, but the positive predictive value of the test was only 17% when the prevalence of disease was 2%. We conclude that the CDT should not be used to identify carriers but that it is a sufficiently sensitive and specific screening test for diagnosing C. difficile disease. However, since the positive predictive value of the CDT is low when the prevalence of disease is low, positive test results should be confirmed by the stool cytotoxin assay. 相似文献
103.
A comparison was made of the activities of clinical dextran and bradykinin in rats. Chiefly by using antagonists, major differences were identified and the study confirmed that bradykinin is unlikely to play a major role in the dextran anaphylactoid reaction. 相似文献
104.
Feng J Zheng J Bennett WP Heston LL Jones IR Craddock N Sommer SS 《American journal of medical genetics》2000,96(3):412-417
Steroid hormone administration causes behavior changes in many and psychosis in a few. The clinical features suggest that genetic variants of the glucocorticoid receptor or cofactors could produce susceptible subpopulations who react adversely to hormonal cascades. To investigate this possibility, coding and splice site sequences of the glucocorticoid receptor were scanned for single nucleotide polymorphisms in genomic DNA samples from 100 schizophrenics (86 Caucasians and 14 African-Americans) and 40 Caucasians with puerperal psychosis. Five amino acid substitutions were found in the amino-terminal domain at frequencies of 0.6 to 3.8% in Caucasians: R23K, F29L, L112F, D233N, and N363S. In addition, four silent nucleotide changes were found: E22E, K293K, D677D, and N766N; a transversion in intron 4 occurred beyond the splice junction. None of these variants can be linked to these disorders at present. However, the N363S variant contributes a new potential phosphorylation site and has been associated with increased body mass and reduced bone mineral density [Huizenga et al., 1998], so it is possible that the other missense variants confer traits that currently are unrecognized. Comparisons to natural glucocorticoid receptor mutants in the familial glucocorticoid resistance syndrome and steroid resistant leukemias suggest that amino acid substitutions at highly conserved residues may cause severe functional defects and serious illness, while changes at less conserved sites produce lesser alterations and milder disease. 相似文献
105.
The Masson-Fontana silver stain for melanin was employed for the differentiation of pathogenic fungal species in human or mouse tissues. The fungi studied were Candida albicans, Candida tropicalis, Candida glabrata (Torulopsis glabrata), Cryptococcus neoformans, Cryptococcus bacillisporus, Coccidioides immitis, Blastomyces dermatitidis, Histoplasma capsulatum, Paracoccidioides brasiliensis, Sporothrix schenckii, Rhizopus rhizopodiformis, and Aspergillus fumigatus. The tissue sections stained with Masson-Fontana silver stain showed a dark brown to black color in the wall of cryptococci, whereas the walls of remaining fungal species were hyaline, except for those of S. schenckii. The yeastlike cells of S. schenckii showed faint brown pigment on the wall. Cultures of these fungi showed staining characteristics identical to those of the in vivo results. Cultures of four nonpathogenic Cryptococcus species, Cryptococcus uniguttulatus, Cryptococcus laurentii, Cryptococcus terreus, and Cryptococcus luteolus, were also tested for staining by the Masson-Fontana procedure. Of these, only C. laurentii stained positively, and the pigment on the cell wall was as intense as that of the cells of C. neoformans. These results indicate that the Masson-Fontana silver stain can be used as a specific stain in the histological diagnosis of cryptococcosis. 相似文献
106.
The extent to which protein synthesis is involved in working memory was investigated with the protein synthesis inhibitor anisomycin (ANI). Rats were trained to perform accurately on a 12-arm radial maze when delays of 240 min were interposed between choice 6 and choice 7. Bilateral hippocampal cannulas were then implanted. Accuracy on choices 7-12 was studied when ANI or saline was injected either 30 min before choice 1 or 5-10 min after choice 6 (Experiment 1). Pretrial injection of ANI significantly impaired performance following the 240-min delay, whereas ANI injected during the delay had no such effect. In Experiments 2 and 3, the ANI-induced amnesia was replicated, and the temporal course of development of the amnesia was determined. Pretrial administration of ANI did not significantly affect retention after a 2-min delay but did produce amnesia after delays of 15 min or longer. These data suggest that protein synthesis is important for the formation of temporary memories, provided the retention interval is long enough. It is suggested that working memory includes both short-term and long-term components. Protein synthesis appears to be important for formation of the long-term component, but not the short-term component, of working memory. 相似文献
107.
S R Bennett J P Greer R S Stein A D Glick J B Cousar R D Collins 《American journal of clinical pathology》1984,82(1):104-109
A case of mycosis fungoides in which pathologic rupture of the spleen led to intraperitoneal hemorrhage and death is described. To our knowledge, splenic rupture has not been reported previously as a cause of death in mycosis fungoides. Immunologic studies demonstrated that the neoplastic cell was a suppressor/cytotoxic T-cell. In most cases of mycosis fungoides or the Sézary syndrome, the neoplastic cell has been a helper/inducer T-cell. This case was very aggressive clinically with prominent visceral involvement and suggests that mycosis fungoides may be clinically diverse as well as immunologically heterogeneous. 相似文献
108.
J. L. Deuve N. C. Bennett P. C. M. O’Brien M. A. Ferguson-Smith C. G. Faulkes J. Britton-Davidian T. J. Robinson 《Chromosome research》2006,14(6):681-691
Cross-species chromosome painting was used to determine homologous chromosomal regions between two species of mole-rat, the
naked mole-rat, Heterocephalus glaber (2n = 60), and the giant mole-rat, Cryptomys mechowi (2n = 40), using flow-sorted painting probes representative of all but two of the H. glaber chromosomal complement. In total 43 homologous regions were identified in the C. mechowi genome. Eight H. glaber chromosomes are retained in toto in C. mechowi, and 13 produce two or more signals in this species. The most striking difference in the karyotypes of the two taxa concerns
their sex chromosomes. The H. glaber painting probes identified a complex series of translocations that involved the fractionation of four autosomes and the subsequent
translocation of segments to the sex chromosomes and to autosomal partners in the C. mechowi genome. An intercalary heterochromatic block (IHB) was detected in sex chromosomes of C. mechowi at the boundary with the translocated autosomal segment. We discuss the likely sequence of evolutionary events that has led
to the contemporary composition of the C. mechowi sex chromosomes, and consider these in the light of prevailing views on the genesis of sex chromosomes in mammals. 相似文献
109.
110.
Radcliffe Jerilynn; Bennett David; Kazak Anne E.; Foley Bernadette; Phillips Peter C. 《Journal of pediatric psychology》1996,21(4):529-539
Examined the adjustment of 6- to 18-year-old children and adolescents(n = 38) 2 to 5 years postdiagnosis of brain tumor with respectto standardized measures of anxiety and depression; self-perceptions;and adaptive living skills. Child, mother, and teacher reportdata were used. Maternal adjustment (anxiety and depression,parenting stress) was also assessed. Children and adolescentssurviving brain tumors reported themselves to be generally withinthe normal range. However, maternal ratings of social problemswere higher than normative scores and significantly lower thannorms on social problems, scholastic competence, and communicationskills. Teacher ratings on the Teacher Rating Form were allwithin normal limits. Maternal adjustment measures were withinthe normal range, although the Parent-Child Dysfunctional Interactionsubscale of the Parenting Stress Index was elevated. No differencesin scores were found between children in regular and specialeducation, or between children who had received radiation andthose who did not. This sample of survivors of pediatric braintumors and their mothers had relatively mild problems in adjustment,supporting a competency-based view of the adaptation of pediatricpatients and their families. 相似文献