全文获取类型
收费全文 | 9482篇 |
免费 | 600篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 62篇 |
儿科学 | 313篇 |
妇产科学 | 322篇 |
基础医学 | 1410篇 |
口腔科学 | 121篇 |
临床医学 | 931篇 |
内科学 | 2167篇 |
皮肤病学 | 204篇 |
神经病学 | 895篇 |
特种医学 | 127篇 |
外科学 | 822篇 |
综合类 | 69篇 |
一般理论 | 8篇 |
预防医学 | 1119篇 |
眼科学 | 274篇 |
药学 | 670篇 |
中国医学 | 39篇 |
肿瘤学 | 577篇 |
出版年
2024年 | 7篇 |
2023年 | 70篇 |
2022年 | 200篇 |
2021年 | 356篇 |
2020年 | 206篇 |
2019年 | 286篇 |
2018年 | 305篇 |
2017年 | 229篇 |
2016年 | 243篇 |
2015年 | 322篇 |
2014年 | 418篇 |
2013年 | 507篇 |
2012年 | 817篇 |
2011年 | 855篇 |
2010年 | 488篇 |
2009年 | 401篇 |
2008年 | 685篇 |
2007年 | 696篇 |
2006年 | 634篇 |
2005年 | 565篇 |
2004年 | 466篇 |
2003年 | 429篇 |
2002年 | 430篇 |
2001年 | 60篇 |
2000年 | 27篇 |
1999年 | 50篇 |
1998年 | 55篇 |
1997年 | 34篇 |
1996年 | 26篇 |
1995年 | 31篇 |
1994年 | 19篇 |
1993年 | 26篇 |
1992年 | 19篇 |
1991年 | 18篇 |
1990年 | 16篇 |
1989年 | 13篇 |
1988年 | 8篇 |
1987年 | 13篇 |
1986年 | 7篇 |
1985年 | 5篇 |
1984年 | 7篇 |
1983年 | 7篇 |
1982年 | 9篇 |
1981年 | 12篇 |
1980年 | 5篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1973年 | 7篇 |
1972年 | 6篇 |
1960年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
11.
Comorbidities in head and neck cancer: agreement between self-report and chart review. 总被引:1,自引:1,他引:0
Shraddha S Mukerji Sonia A Duffy Karen E Fowler Mumtaz Khan David L Ronis Jeffrey E Terrell 《Otolaryngology--head and neck surgery》2007,136(4):536-542
OBJECTIVES: To determine the accuracy of self-reported comorbidities compared with medical record review and the clinical and sociodemographic characteristics associated with accuracy of self-reported comorbidities. STUDY DESIGN: We conducted a prospective study of 458 newly diagnosed head and neck cancer patients using self-administered questionnaire and medical chart review data. Overall and itemwise consistency between self-report and chart review was evaluated. Social, clinical, and demographic characteristics of consistent versus inconsistent responders were analyzed. RESULTS: Seventy-four percent of patients had at least one comorbidity. There was good overall consistency between self-report and chart review (kappa = 0.50). Compared with consistent responders, inconsistent responders were found to be older (P < 0.05), have lower sleep (P < 0.05) and physical activity scores (P < 0.05), be more depressed (P < 0.05), and have more severe comorbidities (P < 0.05). CONCLUSIONS AND SIGNIFICANCE: Self-report may be considered as an alternative to chart review for comorbidity assessment in head and neck cancer patients. Younger patients, those with good general health, fewer depressive symptoms, and mild comorbidities, are more likely to give responses consistent with chart review. 相似文献
12.
In reaction time (RT) tasks, event-related potentials (ERPs) reveal a response-locked negative wave when subjects commit errors. This wave, termed "error negativity" (Ne) or "error-related negativity" (ERN), is thought to index response-monitoring processes. With conventional monopolar recordings, this negativity is hardly seen on correct responses, likely overlapped by a large positive wave. Indeed, after Laplacian transformation (a spatial high-pass filter), a small Ne-like wave is unmasked. Recently, it has been shown that the positivity on monopolar recordings was larger for correct responses preceding an error than for correct responses preceding a correct trial. After Laplacian transformation, it appears that this effect is due, at least in part, to a decrease of the Ne-like wave on correct responses preceding an error. This result indicates that, as the Ne on errors, the Ne-like wave on correct responses is sensitive to performance and hence is likely related to response-monitoring processes. 相似文献
13.
López-Giral S Quintana NE Cabrerizo M Alfonso-Pérez M Sala-Valdés M De Soria VG Fernández-Rañada JM Fernández-Ruiz E Muñoz C 《Journal of leukocyte biology》2004,76(2):462-471
B cell neoplasms present heterogeneous patterns of lymphoid organ involvement, which may be a result of the differential expression of chemokine receptors. We found that chemokine receptor (CCR)7, CXC chemokine receptor (CXCR)4, or CXCR5, the main chemokine receptors that mediate B cell entry into secondary lymphoid tissues and their homing to T cell and B cell zones therein, were highly expressed in B malignancies with widespread involvement of lymph nodes. Conversely, those pathologies with little or no nodular dissemination showed no expression to very low levels of CCR7 and CXCR5 and low to moderate levels of CXCR4. These findings provide evidence for the role of CCR7, CXCR4, and CXCR5 in determining the pattern of lymphoid organ involvement of B tumors. Functional studies were performed on B malignancies expressing different levels of CCR7, CXCR5, and CXCR4. Multiple myeloma (MM) cells did not express CCR7 nor CXCR5 and did not migrate in response to their ligands; a moderate expression of CXCR4 on MM cells was accompanied by a migratory response to its ligand, CXCL12. By contrast, cells from B cell chronic lymphocytic leukemia (B-CLL) expressed the highest levels of these chemokine receptors and efficiently migrated in response to all ligands of CCR7, CXCR4, and CXCR5. In addition, the migration index of B-CLL cells in response to both of the CCR7 ligands correlated with the presence of clinical lymphadenopathy, thus indicating that the high expression of functional chemokine receptors justifies the widespread character of B-CLL, representing a clinical target for the control of tumor cell dissemination. 相似文献
14.
Sonia Ehrlich Tania Bustos Inder J. Paika Aubrey Milunsky John M. Opitz 《American journal of medical genetics. Part A》1983,15(2):261-263
Some variation in the phenotype of patients with dup(18q) is recognized. Our patient has the phenotype described for dup(18qter). 相似文献
15.
Contraceptive use among South Asian women attending general practices in southwest London. 下载免费PDF全文
Sonia Saxena Pippa Oakeshott Sean Hilton 《The British journal of general practice》2002,52(478):392-394
A cross-sectional survey of contraceptive practices was conducted among 180 South Asian women aged 16 to 50 years, attending inner-city general practices. Overall prevalence of contraceptive use was 63% and ranged from 70% in South Asian teenagers, to only 50% in women over 30 who had completed their family. Thirteen per cent of women had had a termination of pregnancy Although contraceptive use in this group is increasing, it has not yet reached national levels. 相似文献
16.
17.
18.
Ben Jemaa Z Mahjoubi F Ben Haj H'mida Y Hammami N Ben Ayed M Hammami A 《Pathologie-biologie》2004,52(2):82-88
Antimicrobial susceptibility and frequency of occurrence of clinical blood isolates in Sfax-Tunisia (1993-1998). The choice of antimicrobial therapy for the treatment of bacteremia is often empirical and based on the knowledge of susceptibility profiles of the most common bacteria causing such infections. This study determines the bacterial etiology of bacteremic episodes and antimicrobial susceptibility patterns recorded at a teaching hospital, from January 1993 to December 1998. We collected 2979 strains responsible for bacteremia. Gram negative bacteria were predominant (60%). The organisms recovered most frequently were Staphylococcus aureus (18.9%), Escherichia coli (14.7%), Klebsiella pneumoniae (14%) and Pseudomonas aeruginosa (7.6%). The incidence of resistance to methicillin were 17.4% for Staphylococcus aureus and 26.8% for coagulase negative Staphylococcus. No resistance to glycopeptides was observed among the enterococci and staphylococci studied. 27.7% of enterobacteriaceae were resistant to third generation cephalosporins. Imipenem was the most active agent against gram negative bacteria. To carry out a surveillance of bacteremic episodes occurring at every hospital, it is necessary to provide valuable information which should be the basis for effective empiric therapy. 相似文献
19.
Heterogeneous pattern of chromosomal breakpoints involving the MYC locus in multiple myeloma 总被引:2,自引:0,他引:2
Fabris S Storlazzi CT Baldini L Nobili L Lombardi L Maiolo AT Rocchi M Neri A 《Genes, chromosomes & cancer》2003,37(3):261-269
Chromosomal rearrangements of the MYC locus, which often involve the IG loci, are recurrent events in multiple myeloma (MM) and plasma cell leukemia (PCL). We used dual-color fluorescence in situ hybridization (FISH) to characterize the breakpoint locations of chromosomal translocations/rearrangements involving the MYC locus at 8q24 found in a panel of 14 MM cell lines and 70 primary tumors (66 MM and 4 PCL). MYC locus alterations were observed in 21 cases: MYC/IG (mainly IGH@) fusions in 11 cell lines and three patients (2 MM and 1 PCL), and extra signals and/or abnormal MYC localizations in seven patients (5 MM and 2 PCL). Fourteen of these cases were investigated by FISH analyses by use of a panel of BAC clones covering about 6 Mb encompassing the MYC locus. The breakpoints were localized in a region 100-250 kb centromeric to MYC in four cases, a region 500-800 kb telomeric to the gene in four cases, and regions > or = 2 Mb centromeric or telomeric to MYC in five cases. Two different breakpoints were detected in the KMS-18 cell line, whereas the insertion of a MYC allele was found in a complex t(16;22) chromosomal translocation in the RPMI8226 cell line. Our data document a relatively high dispersion of 8q24 breakpoints in MM. 相似文献
20.
Maria do Carmo Debur Juliano Bordignon Claudia Nunes Duarte dos Santos Luine Rosele Vidal Meri Bordignon Nogueira Sérgio Monteiro de Almeida Sonia Mara Raboni 《Journal of clinical virology》2007,39(1):59-62
BACKGROUND: Human metapneumovirus (hMPV) has been described as an etiologic agent of acute respiratory infections (ARI), mainly in pediatric patients. Viral isolation is difficult and has low sensitivity, and consequently RT-PCR assays are currently used for detection. OBJECTIVES: Detect hMPV in ARI in hospitalized children in Southern Brazil; standardize a RT-PCR for routine hMPV diagnosis; validate a positive control for molecular tests; and perform phylogenetics analyses. STUDY DESIGN: Nasopharyngeal aspirates (NPA) from 156 hospitalized children were studied. A conserved region of the nucleoprotein gene was cloned, characterized and used to standardize an RT-PCR assay. Phylogenetic analyses were performed. Clinical data were obtained from medical records. RESULTS: hMPV was detected in 6.4% of the samples. Dyspnea and wheezing were frequently reported symptoms and the most common diagnoses were bronchiolitis, acute respiratory insufficiency or laryngotracheobronchitis. Nucleotide sequence alignment revealed 97.7% identity with genotype A1 of hMPV. The detection limit of hMPV genomes by RT-PCR in clinical samples was 180 copies/microL. CONCLUSION: This is the first report of the detection and genetic characterization of hMPV infections in children with lower ARI in Southern Brazil. 相似文献