全文获取类型
收费全文 | 956篇 |
免费 | 47篇 |
国内免费 | 35篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 73篇 |
妇产科学 | 8篇 |
基础医学 | 112篇 |
口腔科学 | 53篇 |
临床医学 | 110篇 |
内科学 | 213篇 |
皮肤病学 | 23篇 |
神经病学 | 19篇 |
特种医学 | 190篇 |
外科学 | 54篇 |
综合类 | 26篇 |
预防医学 | 52篇 |
眼科学 | 14篇 |
药学 | 36篇 |
中国医学 | 2篇 |
肿瘤学 | 40篇 |
出版年
2022年 | 5篇 |
2021年 | 14篇 |
2020年 | 4篇 |
2019年 | 13篇 |
2018年 | 21篇 |
2017年 | 13篇 |
2016年 | 17篇 |
2015年 | 24篇 |
2014年 | 22篇 |
2013年 | 35篇 |
2012年 | 24篇 |
2011年 | 18篇 |
2010年 | 47篇 |
2009年 | 44篇 |
2008年 | 24篇 |
2007年 | 34篇 |
2006年 | 27篇 |
2005年 | 46篇 |
2004年 | 22篇 |
2003年 | 11篇 |
2002年 | 12篇 |
2001年 | 23篇 |
2000年 | 18篇 |
1999年 | 22篇 |
1998年 | 48篇 |
1997年 | 49篇 |
1996年 | 49篇 |
1995年 | 34篇 |
1994年 | 40篇 |
1993年 | 35篇 |
1992年 | 13篇 |
1991年 | 18篇 |
1990年 | 10篇 |
1989年 | 24篇 |
1988年 | 48篇 |
1987年 | 19篇 |
1986年 | 15篇 |
1985年 | 28篇 |
1984年 | 6篇 |
1983年 | 2篇 |
1982年 | 6篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1978年 | 5篇 |
1977年 | 7篇 |
1976年 | 12篇 |
1975年 | 3篇 |
1973年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有1038条查询结果,搜索用时 15 毫秒
71.
Liu J Zheng BS Aposhian HV Zhou YS Chen ML Zhang AH Waalkes MP. 《Journal of the peripheral nervous system : JPNS》2002,7(3):208-208
Optimization of a previously disclosed sorbitol dehydrogenase inhibitor (SDI, II) for potency and duration of action was achieved by replacing the metabolically labile N,N-dimethylsulfamoyl group with a variety of heterocycles. Specifically, this effort led to a series of novel, in vitro potent SDIs with longer serum half-lives and acceptable in vivo activity in acutely diabetic rats (e.g., 62, 67, and 69). However, the desired in vivo potency in chronically diabetic rats, ED90 less than or equal to 5 mg/kg/day, was achieved only through further modification of the piperazine linker. Several members of this family, including 86, showed better than the targeted potency with ED90 values of 1-2 mg/kg/day. Compound 86 was further profiled and found to be a selective inhibitor of sorbitol dehydrogenase, with excellent pharmacodynamic/pharmacokinetic properties, demonstrating normalization of sciatic nerve fructose in a chronically diabetic rat model for approximately 17 h, when administered orally at a single dose of 2 mg/kg/day. 相似文献
72.
Oscillatory motion of the normal cervical spinal cord 总被引:2,自引:0,他引:2
73.
Williamson MR; Boyd CM; McGuire EL; Angtuaco T; Westbrook KC; Lang NP; Alston J; Broadwater JR; Navab F; Bersey ML 《Radiology》1986,159(1):272-273
The nuclear medicine bleeding scan is frequently insufficient to locate sites of bleeding precisely, in spite of its great sensitivity. A small, hand-held Geiger-Müller counter, placed directly on exposed intestine in the operating room, enables precise location of the probable bleeding site. In three patients, the technique allowed a minimal amount of intestine to be resected, distinguished between large- and small-intestinal hemorrhage, and eliminated other foci as sites of bleeding. 相似文献
74.
75.
76.
After the introduction of the lateral compactage of gutta percha in endodontic clinic of OdontoStomatology Institute of Dakar in 1995; the immediate evaluation of the quality and the limit of the canal obturation due to a prospective study on 157 monoradicular teeth so be 168 canals (11 supplementary canals) has shown that 75% of canals are of type I of Vertucci and that the apical limit of security is reached within 80.25% of cases. The manual step back canal preparation (79.17%) and the technique of canal obturation by lateral compactage of gutta percha [(64.88%); Apical limit of security: 59.52%] permit to obtain a densities (95.83%) and homogeneous (79.57%) canal obturation. The indication of gutta percha compactage on monoradicular teeth (hermetic and tridimensional root canal filling) must avail to apical curved roots of lateral incisive, the use of adapted instruments in case of canines (31 mm) and apical stop cone on necrotic pulp teeth. 相似文献
77.
Objective To explore the characteristics of arrhythmogenic right ventricular cardiomyopathy (ARVC). Methods Seven patients with arrhythmogenic right ventricular cardiomyopathy and 34 members of three families were studied. All patients and family members underwent history collection, clinical examination, electrocardiogram (ECG), two-dimensional echocardiography (2-DE) and a signal averaging electrocardiogram. Programmed ventricular stimulation was performed in five patients. Results All patients and family members had normal morphologic characteristics and normal function of the left ventricular by 2-DE. Fourteen persons had abnormal findings indicating ARVC. Five had enlargement of the right ventricular with diffused hypocontractility, eight had thin and systolic bulging in the focal anterior wall with hypokinesia and one had bulging of the inferior wall. Twenty-five persons (seven patients and 18 family members) had abnormal findings in ECG. Positive ventricular late potential was recorded in 13 persons (six patients). Two to three monomorphic ventricular tachycardia (VT) with left bundle branch block (LBBB) configurations were induced in five patients. Ventricular fibrillation was induced in two patients during the electrophysiologic study (EPS). Five patients had very high pacing threshold and/or ineffective pacing in one or many regions of the right ventricle. Two members of one family died suddenly. One member was a dwarf with ARVC. Spontaneous VT with a left bundle branch block (LBBB) configuration was recorded in five patients, polymorphic VT with extremely short coupling interval in one, and premature ventricular complexes with LBBB configuration in 12 (six patients). Conclusion Our familial study strongly suggests that ARVC may be a hereditary disease and it is helpful in the diagnosis and detection of ARVC. The most common manifestations were abnormal structure and function of the right ventricle and abnormal ECG of repolarization and ventricular arrhythmia which originates from the right ventricle. 相似文献
78.
Julia ML Brotherton 《Journal of paediatrics and child health》2014,50(12):959-965
The development of efficacious prophylactic human papillomavirus vaccines provided an opportunity for the primary prevention of related infections and diseases. Certain oncogenic human papillomaviruses that preferentially infect the genital epithelium cause cervical cancer and a substantial proportion of anal, penile, vaginal, vulvar and oropharyngeal cancers. Following extensive clinical trials demonstrating their efficacy and safety, two vaccines have been in global use for over 6 years. This review summarises the accumulated evidence regarding their high level of efficacy, safety in population usage, reductions in genital warts, infections and cervical disease following their adoption, and facilitators and barriers to achieving high vaccination coverage. The review also discusses practical issues and frequently asked questions regarding duration of effect, vaccination of women treated for cervical disease and alternate vaccination schedules, as well as the need to review cervical screening strategies in the post‐ vaccination environment. 相似文献
79.
B-cell acute lymphoblastic leukemia (B-ALL), more frequently than any other B-lineage neoplasm, exhibits oligoclonal Ig heavy chain (IgH) gene rearrangement in 15% to 43% of all cases studied. To study the molecular processes that promote multiple IgH rearrangements, a comprehensive sequence analysis of a B-ALL case was performed in which seven clonal IgH gene rearrangements were identified. The genetic profiles suggested that a single leukemic progenitor clone evolved into several subclones through dual processes of variable (VH) to preexisting diversity-joining (DJH) gene segment rearrangement and VH to VH gene replacement. Predominant IgH-V usage and the uniquely rearranged clonotype-specific VHDJH region gene sequences were identified using a novel DNA-based gene amplification strategy. Polymerase chain reaction (PCR) was directed by an IgH-J generic primer and a complement of family-specific IgH-V primers that defined the major B-cell IgH-V gene usage. Clonality of rearranged VHDJH bands was substantiated by high resolution denaturant gel electrophoretic analysis. Sequence patterns of the amplified VHDJH fragments segregated into two groups defined by common DJH sequences. Partial N region homology at the VHD junction as well as shared DJH sequences firmly established VH to VHDJH gene replacement as a mechanism generating clonal evolution in one group. In the second subset, oligoclonality was propagated by independent VH gene rearrangements to a common DJH precursor. The contributions of all clonal Ig-VHDJH repertoires for each group was approximately 50% and reflected a symmetric distribution of leukemic subclones generated by either process. Thus, oligoclonal rearrangements evolved by two independent, yet seemingly contemporaneous molecular genetic mechanisms. All seven clones displayed nonfunctional Ig-VHDJH recombinations. These observations may have relevance to the recombinatorial opportunities available during normal B-cell maturation. 相似文献
80.
S Paeschke N Horn C Fotopoulou A Zambon-Bertoja A Sollwedel ML Zenclussen P Casalis J Dudenhausen HD Volk F Chen A Zenclussen 《American journal of reproductive immunology (New York, N.Y. : 1989)》2005,54(2):120-121
The acceptance of the semiallogeneic fetus within the maternal environment requires tolerance mechanisms not fully characterized yet. Normal pregnancy is known to be associated with a Th2 profile. Furthermore, T-regulatory cells were proposed to regulate the Th2/Th1 balance at early stages of pregnancy. Treg may avoid the shift to a Th1 profile preventing miscarriage. Accordingly, spontaneous abortion is characterized by a Th1 dominance and diminished levels of Tregulatory cells (Treg). The major aim of the present work was to investigate if pre-eclampsia, a late immunological complication of pregnancy, is characterized by similar hallmarks. Therefore, we measured the surface antigens CD4, CD25, CD8, CTLA4 (as well as the secretion of IL-10) in peripheral blood from patients suffering from pre-eclampsia (n = 8) and age-matched patients undergoing normal pregnancies (n = 9) by 4-colour flow-cytometry. We were not able to find any significant differences in the levels of CD4+ , CD25+ , CD8+ , CTLA4, CD4+ /CD25+ , CD4+ /CD25bright , CD4+ /CTLA4, CD25+ /CTLA4, CD4+ /CD25+ /CTLA4, CD8+ /CD25+ , CD8+ /CTLA4 or CD8+ /CD25+ /CTLA4 cell subsets. Our data suggest that Treg may not participate in the onset of pre-eclampsia and suggest other regulatory mechanisms during late pregnancy. 相似文献