全文获取类型
收费全文 | 1109篇 |
免费 | 84篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 19篇 |
妇产科学 | 20篇 |
基础医学 | 154篇 |
口腔科学 | 27篇 |
临床医学 | 131篇 |
内科学 | 255篇 |
皮肤病学 | 16篇 |
神经病学 | 90篇 |
特种医学 | 30篇 |
外科学 | 184篇 |
综合类 | 10篇 |
预防医学 | 109篇 |
眼科学 | 37篇 |
药学 | 53篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 6篇 |
2022年 | 11篇 |
2021年 | 17篇 |
2020年 | 13篇 |
2019年 | 16篇 |
2018年 | 22篇 |
2017年 | 14篇 |
2016年 | 12篇 |
2015年 | 21篇 |
2014年 | 22篇 |
2013年 | 37篇 |
2012年 | 53篇 |
2011年 | 62篇 |
2010年 | 32篇 |
2009年 | 20篇 |
2008年 | 47篇 |
2007年 | 59篇 |
2006年 | 63篇 |
2005年 | 56篇 |
2004年 | 45篇 |
2003年 | 41篇 |
2002年 | 48篇 |
2001年 | 34篇 |
2000年 | 41篇 |
1999年 | 31篇 |
1998年 | 22篇 |
1997年 | 14篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1992年 | 7篇 |
1991年 | 9篇 |
1990年 | 21篇 |
1989年 | 16篇 |
1988年 | 17篇 |
1987年 | 14篇 |
1986年 | 15篇 |
1985年 | 8篇 |
1984年 | 11篇 |
1983年 | 11篇 |
1982年 | 14篇 |
1981年 | 12篇 |
1980年 | 11篇 |
1979年 | 10篇 |
1977年 | 6篇 |
1976年 | 6篇 |
1974年 | 9篇 |
1973年 | 11篇 |
1972年 | 6篇 |
1971年 | 6篇 |
1969年 | 7篇 |
排序方式: 共有1197条查询结果,搜索用时 430 毫秒
1.
2.
T W Mattox R O Brown B A Boucher E A Buonpane T C Fabian R W Luther 《JPEN. Journal of parenteral and enteral nutrition》1988,12(6):592-596
The purpose of this study was to evaluate the use of serum fibronectin and serum somatomedin-C as nutritional markers during enteral nutrition support (ENS) of critically ill, traumatized patients using an enteral product containing high concentrations of branched-chain amino acids. Twelve critically injured patients received a standard enteral formula with 30 g of a 44% branched-chain amino acid supplement added to each liter of formula. Fibronectin concentration, somatomedin-C concentration, and nitrogen balance were measured on study days 1, 4, 7, 14, 21, 28 or until adequate oral intake began. Both fibronectin and somatomedin-C concentrations increased significantly from baseline by day 7 of ENS. Nitrogen balance increased significantly from baseline by day 4. On days 14 and 21, only somatomedin-C and nitrogen balance increased significantly from baseline. Nitrogen balance was significantly correlated with somatomedin-C concentration (r = 0.53, p less than 0.01), cumulative caloric intake (r = 0.68, p less than 0.01), and cumulative nitrogen intake (r = 0.72, p less than 0.01). The results of this study suggest that serum somatomedin-C is useful and serum fibronectin has potential in monitoring nutrition support response in critically ill, traumatized patients. 相似文献
3.
J B?rsch R Luther J Preisler R Grünewald 《Zeitschrift für die gesamte innere Medizin und ihre Grenzgebiete》1988,43(5):119-121
We made a retrospective analysis with regard to the bacteriology and to the therapy of all patients with pleural empyema who were treated in the district lung hospital from 1. 1. 1982-31. 12. 1986. 92 patients had a non-specific empyema, only 3 patients had a specific empyema. All patients were aspirated repeatedly with physiological saline solution instillation and antimicrobic drug instillation in the pleural cavity. This daily aspiration and lavage was successfully in 65 patients. This method was ineffective in 30 patients. We treated 7 patients of this group by the closed drainage (rubber-tube drain), in 4 patients successfully. 3 patients had to be treated by a surgical operation. An insufficient obliteration of the cavity of empyema occurred also in 23 patients of this group. A systematic daily aspiration for a longer time led to regression of the cavity in 4 cases, whereas a surgical operation was necessary in 19 patients. We consider the daily aspiration and lavage as an effective method in patients in early acute stages of empyema. 相似文献
4.
F. Luther J. D. Kindelan D. P. Roberts-Harry J. M. H. Dibbets 《European journal of dental education》1998,2(4):165-171
A questionnaire was used to compare undergraduate student satisfaction with orthodontic teaching in two units; one in Leeds, UK, the other in Marburg, Germany. Whilst the methods of teaching differed between the units, the aim was to highlight aspects of both courses which students might wish to see improved. Statistical analysis suggested that students appreciate clarity of course structure and means of assessment and that use of a course manual is helpful in achieving this. Recommended texts to back-up course work are also appreciated whilst students from both locations, want to see more patients. Alternatives, such as patient case folders, computer-assisted learning packages and use of videos showing treatment progression, seem to be acceptable alternatives should there be difficulty in supplying “real” patients. The relevance of laboratory courses needs to be reviewed. Overall, the use of student questionnaires is seen as a useful tool in monitoring standards of teaching. 相似文献
5.
6.
Involvement of pp60c-src with two major signaling pathways in human breast cancer. 总被引:14,自引:3,他引:11 下载免费PDF全文
D K Luttrell A Lee T J Lansing R M Crosby K D Jung D Willard M Luther M Rodriguez J Berman T M Gilmer 《Proceedings of the National Academy of Sciences of the United States of America》1994,91(1):83-87
The phosphotyrosine residues of receptor tyrosine kinases serve as unique binding sites for proteins involved in intracellular signaling, which contain SRC homology 2 (SH2) domains. Since overexpression or activation of the pp60c-src kinase has been reported in a number of human tumors, including primary human breast carcinomas, we examined the interactions of the SH2 and SH3 domains of human SRC with target proteins in human carcinoma cell lines. Glutathione S-transferase fusion proteins containing either the SH2, SH3, or the entire SH3/SH2 region of human SRC were used to affinity purify tyrosine-phosphorylated proteins from human breast carcinoma cell lines. We show here that in human breast carcinoma cell lines, the SRC SH2 domain binds to activated epidermal growth factor receptor (EGFR) and p185HER2/neu. SRC SH2 binding to EGFR was also observed in a nontumorigenic cell line after hormone stimulation. Endogenous pp60c-src was found to tightly associate with tyrosine-phosphorylated EGFR. Association of the SRC SH2 with the EGFR was blocked by tyrosyl phosphopeptides containing the sequences surrounding tyrosine-530, the regulatory site in the SRC C terminus, or sequences surrounding the major sites of autophosphorylation in the EGFR. These results raise the possibility that association of pp60c-src with these receptor tyrosine kinases is an integral part of the signaling events mediated by these receptors and may contribute to malignant transformation. 相似文献
7.
Epitope-mapped monoclonal antibodies as tools for functional and morphological analyses of the human urokinase receptor in tumor tissue. 总被引:2,自引:2,他引:2 下载免费PDF全文
T. Luther V. Magdolen S. Albrecht M. Kasper C. Riemer H. Kessler H. Graeff M. Müller M. Schmitt 《The American journal of pathology》1997,150(4):1231-1244
uPAR (CD87), the receptor for the urokinase-type plasminogen activator (uPA) facilitates tumor cell invasion and metastasis by focusing uPA proteolytic activity to the cell surface. As uPAR exists in various molecular forms, it is desirable to use well defined antibodies for analyses of uPAR antigen expression in human malignant tumors by immunological methods. Therefore, twelve monoclonal antibodies (MAbs) directed against uPAR were generated by using nonglycosylated, recombinant human uPAR (spanning amino acids 1 to 284), expressed in Escherichia coli, as the immunogen. The reaction pattern of these MAbs with the immunogen and a series of carboxyl-terminally truncated versions of uPAR demonstrated that at least six different epitopes of uPAR are recognized. All MAbs reacted under reducing conditions in immunoblot analyses with E. coli-expressed uPA and also with highly glycosylated, functionally intact, recombinant human uPAR expressed in Chinese hamster ovary (CHO) cells. Seven of the MAbs recognized CHO uPAR under nonreducing conditions as well. By flow cytofluorometric analyses, three of these MAbs were shown to bind to native human uPAR present on the cell surface of monocytoid U937 cells with MAb IIIF10 being the best. Saturation of uPAR with uPA on U937 cells completely blocked interaction of MAb IIIF10 with uPAR (mapped epitope, amino acids 52 to 60 of domain I of uPAR). In turn, preincubation of U937 cells with MAb IIIF10 efficiently reduced binding of uPA to uPAR, indicating that the epitope detected by MAb IIIF10 is located within or closely to the uPA-binding site of uPAR, and thus, this site may be a target to influence uPA/uPAR-mediated proteolysis in tumors. Binding of MAbs IID7 or IIIB11 (mapped epitope, amino acids 125 to 132 of domain II of uPAR) to uPAR is not affected when uPAR is occupied by uPA. As these MAbs reacted strongly with cellular uPAR antigen in formalin-fixed paraffin-embedded tumor sections, the domain-II-specific antibodies IID7 and IIIB11 may be useful for immunohistochemical studies of uPAR expression in tissue remodeling processes in tumor invasion. In conclusion, we have devised well defined and epitope-mapped MAbs to uPAR that are highly specific tools for detection and targeting of uPAR in tumor tissue. 相似文献
8.
Frank Greenberg Luther K. Robinson John M. Opitz James F. Reynolds 《American journal of medical genetics. Part A》1989,32(1):90-92
We present a girl with mild manifestations of the Brachmann-de Lange syndrome (BDLS) with gradual change of the phenotype. Her findings support the hypothosis of variability of the phenotypic spectrum of the disorder. 相似文献
9.
Genotyping of a homogeneous group of Yersinia pestis strains isolated in the United States 下载免费PDF全文
Yersinia pestis, the causative agent of deadly plague, is considered a reemerging infectious disease and a significant biological terrorism threat. The present project focused on epidemiological investigation of the genetic variability of well-documented strains of Y. pestis from the United States by pulsed-field gel electrophoresis (PFGE) and restriction fragment length polymorphism (RFLP) analysis with insertion sequences IS100 and IS285 as probes. We examined 37 U.S. Y. pestis strains and isolates of a single ribotype, ribotype B, recovered between 1939 and 1998 from patients, animals, and fleas. Our results showed that all isolates had similar PFGE patterns, but minor differences such as missing, additional, and shifted bands were found among almost all strains if they came from different parent strains. The 37 strains and isolates were divided into 26 PFGE types. RFLP analysis with IS100 as a probe divided these strains and isolates into 16 types, with 43% belonging to IS100 type 1. Typing with IS285 as a probe was less specific and led to only four RFLP types, with 81% belonging to type 1. Similarity analysis with BioNumerics software showed that all strains shared >or=80, 86, and 91% similarities on dendrograms prepared from digitized PFGE, IS100 RFLP analysis, and IS285 RFLP analysis images, respectively. Our results demonstrate that PFGE offers an increased ability to discriminate between strains (Simpson's index of diversity, 0.98) and therefore can significantly improve epidemiological studies related to the origin of new plague isolates. 相似文献
10.
Comorbid psychiatric disorders in depressed outpatients: demographic and clinical features 总被引:2,自引:0,他引:2
Rush AJ Zimmerman M Wisniewski SR Fava M Hollon SD Warden D Biggs MM Shores-Wilson K Shelton RC Luther JF Thomas B Trivedi MH 《Journal of affective disorders》2005,87(1):43-55
BACKGROUND: This study evaluated the clinical and sociodemographic features associated with various degrees of concurrent comorbidity in adult outpatients with nonpsychotic major depressive disorder (MDD). METHODS: Outpatients enrolled in the STAR*D trial completed the Psychiatric Diagnostic Screening Questionnaire (PDSQ). An a priori 90% specificity threshold was set for PDSQ responses to ascertain the presence of 11 different concurrent DSM-IV Axis I disorders. RESULTS: Of 1376 outpatients, 38.2% had no concurrent comorbidities, while 25.6% suffered one, 16.1% suffered two, and 20.2% suffered three or more comorbid conditions. Altogether, 29.3% met threshold for social anxiety disorder, 20.8% for generalized anxiety disorder, 18.8% for posttraumatic stress disorder, 12.4% for bulimia, 11.9% for alcohol abuse/dependence, 13.4% for obsessive-compulsive disorder, 11.1% for panic disorder, 9.4% for agoraphobia, 7.3% for drug abuse/dependence, 3.7% for hypochondriasis, and 2.2% for somatoform disorder. Those with more concurrent Axis I conditions had earlier ages at first onset of MDD, longer histories of MDD, greater depressive symptom severity, more general medical comorbidity (even though they were younger than those with fewer comorbid conditions), poorer physical and mental function, health perceptions, and life satisfaction; and were more likely to be seen in primary care settings. LIMITATIONS: Participants had to meet entry criteria for STAR*D. Ascertainment of comorbid conditions was not based on a structured interview. CONCLUSIONS: Concurrent Axis I conditions (most often anxiety disorders) are very common with MDD. Greater numbers of concurrent comorbid conditions were associated with increased severity, morbidity, and chronicity of their MDD. 相似文献