全文获取类型
收费全文 | 12093篇 |
免费 | 1296篇 |
国内免费 | 124篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 334篇 |
妇产科学 | 379篇 |
基础医学 | 1633篇 |
口腔科学 | 213篇 |
临床医学 | 1390篇 |
内科学 | 2841篇 |
皮肤病学 | 193篇 |
神经病学 | 1326篇 |
特种医学 | 763篇 |
外国民族医学 | 1篇 |
外科学 | 1237篇 |
综合类 | 239篇 |
一般理论 | 11篇 |
预防医学 | 1196篇 |
眼科学 | 169篇 |
药学 | 732篇 |
中国医学 | 1篇 |
肿瘤学 | 793篇 |
出版年
2021年 | 123篇 |
2020年 | 116篇 |
2019年 | 150篇 |
2018年 | 181篇 |
2017年 | 150篇 |
2016年 | 182篇 |
2015年 | 216篇 |
2014年 | 282篇 |
2013年 | 398篇 |
2012年 | 528篇 |
2011年 | 529篇 |
2010年 | 338篇 |
2009年 | 321篇 |
2008年 | 565篇 |
2007年 | 567篇 |
2006年 | 495篇 |
2005年 | 526篇 |
2004年 | 407篇 |
2003年 | 365篇 |
2002年 | 320篇 |
2001年 | 321篇 |
2000年 | 388篇 |
1999年 | 325篇 |
1998年 | 225篇 |
1997年 | 217篇 |
1996年 | 237篇 |
1995年 | 165篇 |
1994年 | 148篇 |
1993年 | 154篇 |
1992年 | 259篇 |
1991年 | 296篇 |
1990年 | 265篇 |
1989年 | 274篇 |
1988年 | 233篇 |
1987年 | 266篇 |
1986年 | 264篇 |
1985年 | 264篇 |
1984年 | 181篇 |
1983年 | 162篇 |
1982年 | 128篇 |
1981年 | 107篇 |
1980年 | 120篇 |
1979年 | 177篇 |
1978年 | 113篇 |
1977年 | 105篇 |
1976年 | 106篇 |
1975年 | 109篇 |
1974年 | 101篇 |
1973年 | 102篇 |
1972年 | 93篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
We investigated the effects of group socialization procedures on the social behavior of preschool children in two studies. Group socialization procedures consisted of teachers using antecedent and consequent events to promote social interaction during children's games. During intervention, teachers discussed friendship with the children and then prompted and praised child-child social responding within the context of games. Children's social behavior was assessed during two sessions, group game periods (i.e., intervention sessions) and nonintervention play periods (i.e., generalization sessions). In both studies, a multiple baseline design across two target children and peers in their respective group was used to evaluate the effects of group socialization procedures. During group game periods, after intervention, target children increased their rates of both prompted and unprompted social interactions with peers. Also, in nonintervention play periods, target children improved both the rate and the duration of their social responding with peers. Results indicated that group socialization procedures were a practical and effective method for improving young children's social interaction during both structured games and unstructured play activities. 相似文献
52.
53.
AIMS: To study the pattern of expression and prognostic importance of c-erbB-2 protein in cervical carcinoma. METHODS: Sixty two cases of stage IB/IIA cervical carcinoma, representing the three main tumour types, were investigated immunohistochemically for the presence of c-erbB-2 protein expression, using a monoclonal antibody (CB11) to its internal domain. Follow up of at least five years' duration was available in all cases. RESULTS: Definite membrane staining was seen in 38.7% of cases. There was a strong correlation with poor survival (p less than 0.0001) particularly. For those with adenocarcinomas, this was the case when nodal metastases were present. In contrast, for squamous carcinomas and adenosquamous carcinomas, the association with a poor prognosis was most apparent in those patients without lymph node metastases. CONCLUSIONS: These findings raise the possibility that immunostaining for c-erbB-2 protein could be used as a prognostic marker and may help identify those patients for whom early adjuvant treatment might be beneficial. 相似文献
54.
K Rockwood R A Fox P Stolee D Robertson B L Beattie 《Canadian Medical Association journal》1994,150(4):489-495
55.
Coronary thrombolysis is an attractive approach for salvaging jeopardized, ischemic myocardium. The advent of second- and third-generation clot-selective thrombolytic agents will make this approach safer and more widely applicable in the future. However, residual stenoses and reocclusion are common after the thrombolytic therapy. In addition to thrombolysis, future management of coronary thrombosis may include adjunctive pharmacologic therapy such as calcium-channel antagonists, beta-blockers, or oxygen free radical scavengers, and/or mechanical interventions such as balloon or laser angioplasty, or bypass surgery. 相似文献
56.
William G. Kohn Jonathan A. Ship Jane C. Atkinson Lauren L. Patton Philip C. Fox 《Journal of oral pathology & medicine》1992,21(2):70-74
Sequential salivary gland scintigraphy with 99mTc-technetium pertechnetate (Tc-99) is a safe, minimally invasive test for study of major salivary glands. However, its relationship to salivary function has not been investigated in detail. We have investigated the relationship between major salivary gland flow rates and Tc-99 scans and developed a new rating scale using scans of a control group with normal salivary function. Salivary flow rates and Tc-99 scans were obtained from healthy, non-medicated subjects (n = 33) and from xerostomic patients (n = 22). There were significant differences between the groups for salivary flow rates and Tc-99 ratings. Significant correlations were found between salivary flow rates and Tc-99 ratings in the control and xerostomic groups. The Tc-99 rating scale proved reliable in assessing salivary dysfunction, and showed a high inter-examiner correlation. These results demonstrate the usefulness of salivary gland scintigraphy in assessing major salivary gland flow rates and the utility of a new rating scale. 相似文献
57.
Characterization of a benzyladenine binding-site peptide isolated from a wheat cytokinin-binding protein: sequence analysis and identification of a single affinity-labeled histidine residue by mass spectrometry 总被引:3,自引:1,他引:2
下载免费PDF全文
![点击此处可从《Proceedings of the National Academy of Sciences of the United States of America》网站下载免费的PDF全文](/ch/ext_images/free.gif)
A C Brinegar G Cooper A Stevens C R Hauer J Shabanowitz D F Hunt J E Fox 《Proceedings of the National Academy of Sciences of the United States of America》1988,85(16):5927-5931
A wheat embryo cytokinin-binding protein was covalently modified with the radiolabeled photoaffinity ligand 2-azido-N6-[14C]benzyladenine. A single labeled peptide was obtained after proteolytic digestion and isolation by reversed-phase and anion-exchange HPLC. Sequencing by classical Edman degradation identified 11 of the 12 residues but failed to identify the labeled amino acid. Analysis by laser photodissociation Fourier-transform mass spectrometry of 10 pmol of the peptide independently confirmed the Edman data and also demonstrated that the histidine residue nearest the C terminus (underlined) was modified by the reagent in the sequence Ala-Phe-Leu-Gln-Pro-Ser-His-His-Asp-Ala-Asp-Glu. 相似文献
58.
Background. Paragangliomas of the head and neck are slow-growing tumors that originate from neural crest cells. Between 7% and 9% of these tumors have a familial occurrence. The suspected gene for familial paragangliomas (FP) is transmitted with an autosomal dominant mode of inheritance with incomplete penetrance, and appears to exhibit genomic imprinting. It has been demonstrated by family studies that individuals who inherit the gene(s) from their father will develop the disease. Through linkage analysis, the gene(s) for FP has been postulated to be located on the long arm of chromosome 11. The discovery of many different genes has been elucidated through the cytogenetic analysis of affected individuals who carry specific chromosome aberrations. This project was designed to look for chromosome abnormalities in several second-generation family members to further assist in the localization of the gene(s) for FP. Methods. This study involved the cytogenetic evaluation of lymphocytes, fibroblasts, and tumor cells of several second-generation family members from a three-generation family with FP of the head and neck to look for chromosome abnormalities generally, and for abnormalities of chromosome 11 specifically. Standard cytogenetic techniques were used for lymphocyte and fibroblast cultures. Tumor cells were cultured in a collagen matrix with F12 medium supplemented with 3% L-glutamine and 10% fetal calf serum. Results. There were no detectable abnormalities of chromosome 11 in any of the cells. However, nonrandom abnormalities of chromosomes 5 and 7 were seen in some of the tumor cells of one FP patient. To our knowledge, this is the first article which demonstrated the ability to successfully culture FP of the head and neck. © 1995 Jons Wiley & Sons, Inc. 相似文献
59.
60.
Although Acinetobacter is usually a species of low virulence, it is becoming increasingly more important as a cause of hospital outbreaks, particularly on intensive care units. Antibiotic resistance can develop rapidly. This organism has not been reported to cause skin abscesses previously. We describe a case of a neonate who developed an Acinetobacter abscess on our neonatal intensive care unit. 相似文献