全文获取类型
收费全文 | 7083篇 |
免费 | 499篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 150篇 |
儿科学 | 274篇 |
妇产科学 | 474篇 |
基础医学 | 860篇 |
口腔科学 | 144篇 |
临床医学 | 632篇 |
内科学 | 1705篇 |
皮肤病学 | 228篇 |
神经病学 | 529篇 |
特种医学 | 338篇 |
外科学 | 930篇 |
综合类 | 49篇 |
一般理论 | 1篇 |
预防医学 | 501篇 |
眼科学 | 107篇 |
药学 | 382篇 |
中国医学 | 23篇 |
肿瘤学 | 303篇 |
出版年
2023年 | 25篇 |
2022年 | 55篇 |
2021年 | 183篇 |
2020年 | 85篇 |
2019年 | 205篇 |
2018年 | 277篇 |
2017年 | 147篇 |
2016年 | 142篇 |
2015年 | 162篇 |
2014年 | 233篇 |
2013年 | 289篇 |
2012年 | 330篇 |
2011年 | 399篇 |
2010年 | 293篇 |
2009年 | 276篇 |
2008年 | 355篇 |
2007年 | 424篇 |
2006年 | 356篇 |
2005年 | 368篇 |
2004年 | 309篇 |
2003年 | 254篇 |
2002年 | 273篇 |
2001年 | 223篇 |
2000年 | 268篇 |
1999年 | 201篇 |
1998年 | 107篇 |
1997年 | 78篇 |
1996年 | 81篇 |
1995年 | 60篇 |
1994年 | 74篇 |
1993年 | 62篇 |
1992年 | 113篇 |
1991年 | 96篇 |
1990年 | 101篇 |
1989年 | 93篇 |
1988年 | 129篇 |
1987年 | 75篇 |
1986年 | 71篇 |
1985年 | 59篇 |
1984年 | 39篇 |
1983年 | 19篇 |
1982年 | 18篇 |
1980年 | 15篇 |
1979年 | 19篇 |
1977年 | 20篇 |
1976年 | 22篇 |
1975年 | 17篇 |
1974年 | 22篇 |
1973年 | 21篇 |
1972年 | 17篇 |
排序方式: 共有7630条查询结果,搜索用时 375 毫秒
111.
Adjuvant immunization of HLA-A2-positive melanoma patients with a modified gp100 peptide induces peptide-specific CD8+ T-cell responses. 总被引:3,自引:0,他引:3
John W Smith Edwin B Walker Bernard A Fox Daniel Haley Ketura P Wisner Teri Doran Brenda Fisher Lisa Justice William Wood John Vetto Holden Maecker Annemiek Dols Sybren Meijer Hong-Ming Hu Pedro Romero W Gregory Alvord Walter J Urba 《Journal of clinical oncology》2003,21(8):1562-1573
PURPOSE: To measure the CD8+ T-cell response to a melanoma peptide vaccine and to compare an every-2-weeks with an every-3-weeks vaccination schedule. PATIENTS AND METHODS: Thirty HLA-A2-positive patients with resected stage I to III melanoma were randomly assigned to receive vaccinations every 2 weeks (13 vaccines) or every 3 weeks (nine vaccines) for 6 months. The synthetic, modified gp100 peptide, g209-2M, and a control peptide, HPV16 E7, were mixed in incomplete Freund's adjuvant and injected subcutaneously. Peripheral blood mononuclear cells obtained before and after vaccination by leukapheresis were analyzed using a fluorescence-based HLA/peptide-tetramer binding assay and cytokine flow cytometry. RESULTS: Vaccination induced an increase in peptide-specific T cells in 28 of 29 patients. The median frequency of CD8+ T cells specific for the g209-2M peptide increased markedly from 0.02% before to 0.34% after vaccination (P <.0001). Eight patients (28%) exhibited peptide-specific CD8+ T-cell frequencies greater than 1%, including two patients with frequencies of 4.96% and 8.86%, respectively. Interferon alfa-2b-treated patients also had significant increases in tetramer-binding cells (P <.0001). No difference was observed between the every-2-weeks and the every-3-weeks vaccination schedules (P =.59). CONCLUSION: Flow cytometric analysis of HLA/peptide-tetramer binding cells was a reliable means of quantifying the CD8+ T-cell response to peptide immunization. This assay may be suitable for use in future trials to optimize different vaccination strategies. Concurrent interferon treatment did not inhibit the development of a peptide-specific immune response and vaccination every 2 weeks, and every 3 weeks produced similar results. 相似文献
112.
Immune deficiencies in chronic intestinal pseudo-obstruction 总被引:1,自引:0,他引:1
ML Forchielli MC Young AF Flores D. Richardson CW Lo 《Acta paediatrica (Oslo, Norway : 1992)》1997,86(10):1077-1081
Aim: Chronic intestinal pseudo-obstruction has been associated with urinary disorders, myopathy, and ophthalmoplegia in adults and cholelithiasis in children. We observed a high percentage of total-parenteral-nutrition-dependent patients with pseudo-obstruction and recurrent infections requiring gammaglobulin infusions. Methods: AH records for 23 children with chronic intestinal pseudo-obstruction (10 females and 13 males, mean age 9.8 y ± 4.9 y, range 4–24 y) referred for a nutritional evaluation from 1992 to 1995 were reviewed. Chronic intestinal pseudo-obstruction was diagnosed by clinical, radiographic findings and antroduodenal manometry. Intestinal full-thickness biopsies were performed in seven children. Results: Hypogammaglobulinemia was diagnosed in 18 patients (78%): 16 patients had various immunoglobulin deficiencies and 2 had selective antibody deficiency. Intravenous gammaglobulin was administered in 14 patients. Other medical conditions affecting the children are summarized as follows: autonomic dysfunction in 10 patients (43%), recurrent hypoglycemia in 9 (39%), asthma in 9 (39%), cholecystitis in 7 (30%), low serum carnitine level in 6 (26%), urinary dysfunction in 6 (26%), pancreatitis in 5 (22%), behavioral problems in 5 (22%), myopathy in 2 (9%), idiopathic thrombocytopenia in 2 (8%), velopharyngeal insufficiency in 1 (4%), oculocutaneous albinism in 1 (4%), Pierre-Robin syndrome in 1 (4%), and protein C deficiency in 1 (4%). Munchausen syndrome was suspected in two patients. Conclusions: Chronic intestinal pseudo-obstruction appears to be associated with immune deficiencies. It is unclear if the immune deficiencies, intestinal pseudo-obstruction, and the other medical conditions have a common underlying etiology. Repeated infections may be due to impaired immune function in children with chronic intestinal pseudo-obstruction. We recommend screening for immune deficiencies in children with chronic intestinal pseudo-obstruction. 相似文献
113.
Breast-milk samples from 101 mothers from the basin of Rio Aloya, Nicaragua, were collected on two occasions within the first trimester of lactation. Milk samples were analyzed for 13 organochlorine pesticides: (1) p,p'-dichlorophenyldichloroethylene; (2) p,p'-dichlorophenyltrichloroethane; (3) p,p'-dichlorophenyldichlorodiene; (4) alpha-hexachlorocyclohexane; (5) beta-hexachlorocyclohexane; (6) gamma-hexachlorocyclohexane; (7) delta-hexachlorocyclohexane; (8) toxaphene; (9) dieldrin; (10) endrin; (11) aldrin; (12) heptachlor; and (13) heptachlor-epoxide. Organochlorines of the dichlorodiphenylethane class (i.e., p,p'-dichlorodiphenylethane and p,p'-dichlorodiphenylethane) were found in all samples and at the highest mean concentrations observed in the study. Chemicals in the hexachlorocyclohexane family (i.e., alpha- and delta-hexachlocyclohexane) were not found at all (0%), and the other hexachlorocyclohexane compounds (i.e., beta > gamma) were found in less than 6% of the samples. Twenty percent or less of the sample contained chlorInated cyclodienes (i.e., dieldrin > endrin > heptachlor-epoxide > heptachlor). No measurable concentrations of alpha-hexachlorocyclohexane, aldrin, p,p'-dichlorophenyldichlorodiene, and toxaphene were found in the breast milk samples. Analysis of variance demonstrated that only the concentration of p,p'-dichlorophenyldichloroethylene p,p'-dichlorophenyltrichloroethane, and endrin were affected significantly by maternal age. Overall, with the exception of p,p'-chlorophenyldichloroethylene, and p,p'-dichlorophenyltrichloroethane, the mean concentrations of the analyzed pesticides were low. Total p,p'-dichlorophenyltrichloroethane concentrations that exceeded the allowed daily intake set by the World Health Organisation were found in 5.9% of the samples. 相似文献
114.
Effect of genetic modification of acute inflammatory responsiveness on tumorigenesis in the mouse 总被引:1,自引:3,他引:1
115.
It is currently very rare to find mammary involvement in cases of tuberculosis, in either primary or secondary form. Diagnosis
is classically clinical and microbiological, and the basic techniques used in imaging diagnosis are mammography and ultrasound.
Computed tomography may define the involvement of the thoracic wall in those cases which present as mammary masses adhering
to deep levels, and is also able to evaluate accompanying pulmonary disease, if it is present. Traditionally, treatment has
consisted of quadrantectomy and specific antibiotic therapy. We present a case of tuberculous mammary abscess secondary to
pulmonary disease, which was treated by percutaneous drainage controlled by CT and specific antibiotic therapy. We revise
the diagnosis, differential diagnosis and treatment of mammary tuberculosis.
Received: 27 July 1998; Revision received: 2 February 1999; Accepted: 20 April 1999 相似文献
116.
We studied the cellular distribution of CB1 cannabinoid receptors in the superior colliculus of the rat using an antibody raised against the N-terminal of the receptor. The effect of unilateral cannabinoid receptor stimulation in the intermediate layers of the superior colliculus on rotational behavior in rats was also explored. The antibody against CB1 receptors outlined the crossed descending system of the superior colliculus (predorsal bundle output system) as well as the collicular commisure. The potent cannabinoid agonist CP55,940 (5 microgram/0.25 microliter) induced strong contralateral turning when microinjected unilaterally into the lateral intermediate layers of the superior colliculus. The levels of turning obtained with the intracollicular administration of the cannabinoid were comparable to the highest levels obtained with dopamine agonists in the basal ganglia. The D(2) dopamine agonist quinpirole or the D(1) dopamine agonist SKF82958 reversed this contralateral rotation but failed to affect motor behavior on their own. A new motor pathway for cannabinoids is discussed. 相似文献
117.
118.
Karina Richani Roberto Romero Yeon Mee Kim Enola Cushenberry Eleazar Soto Yu Mi Han Jimmy Espinoza Chong Jai Kim 《The journal of maternal-fetal & neonatal medicine》2006,19(8):509-515
OBJECTIVE: Tissue microarray (TMA) technology allows simultaneous examination of the expression of many molecular markers (protein, mRNA, DNA, etc.) with high-throughput. The application of this technology, to date, has been largely confined to the study of cancer. Placental pathology poses unique challenges because of the size of the organ, its complex anatomy, as well as its histological heterogeneity. The objective of this study was to assess the feasibility and efficiency of TMAs for immunohistochemistry and in situ hybridization of placental tissues. STUDY DESIGN: TMAs were constructed using an automated tissue arrayer. Standard 0.6-mm or 1-mm microarray needles were used. Villous parenchyma, basal plate, and chorioamniotic membranes were targeted in each block. Five mum-thick TMA sections underwent immunohistochemical analysis of both cytoplasmic and nuclear antigens using a panel of antibodies against a variety of cytoplasmic [cytokeratin-7, vascular endothelial growth factor (VEGF), and protein Z], membranous (endoglin), and nuclear (c-fos and c-jun) antigens. mRNA in situ hybridization for surfactant protein A (SP-A) and chromogenic in situ hybridization for the Y chromosome (DYZ1) were also performed. RESULTS: Validation of TMA immunoreactivity demonstrated comparable results with corresponding whole sections. When a two-tiered scoring system (positive/negative) was employed, there was agreement between two and three cores and whole tissue sections (kappa>0.7). When a three-tiered scoring system (negative, weak-positive, or strong-positive) was used, the data from three cores showed the highest agreement with whole tissue sections (kappa >0.7). In situ hybridization experiments for mRNA and DNA were also successful in that the signals were readily detectable. Successful transfer from the donor block to the recipient block differed according to the anatomical compartment. The transfer efficiency of villous parenchyma, basal plate, and chorioamniotic membranes were 96.9% (875/903), 76.7% (115/150), and 75.4% (224/297), respectively. CONCLUSION: TMA is a practical and effective tool for high-throughput molecular analysis of the human placenta. Duplicate and triplicate cores offer agreement with whole tissue sections for two-category distinction immunostaining. TMA also affords relevant results from in situ hybridization experiments for mRNA and DNA. The major advantages are the conservation of tissues and reagents, simultaneous comparison of molecular markers in different anatomical compartments of the placenta, and reduction of experimental error. 相似文献
119.
Event-related potentials as a function of movement parameter variations during motor imagery and isometric action 总被引:4,自引:0,他引:4
Romero DH Lacourse MG Lawrence KE Schandler S Cohen MJ 《Behavioural brain research》2000,117(1-2):83-96
Neuroimaging and electrophysiological studies have shown that executed action and motor imagery activate common neuronal substrates, leading to the hypothesis that movement preparation and motor imagery are functionally equivalent processes. This study further tested the functional equivalence hypothesis by determining whether electrocortical patterns associated with variations in motor control parameters are similar during imagined and executed actions. Event-related potentials (ERPs) were recorded from the supplementary motor/premotor area (SMA/PMA; FCz site) and primary motor area (M1; C3, C4 sites) during an executed and an imagined, cued, discrete isometric contraction task while target force (TF; low, moderate) and rate of force development (RFD; slow, rapid) were varied. For M1, the correlation of ERPs between moderate- and low force-executions was near zero and N2 amplitude was greater for moderate than low force executions, indicating that M1 activity is related to TF. Rapid executions were greater in amplitude and longer in latency than slow executions and the ERPs for rapid- and slow-executions were negatively correlated, indicating that M1 activity is also related to RFD. There were no differences in N2 amplitude and a zero correlation between execution and imagined actions of similar TF and RFD, indicating that neither TF or RFD are represented in M1 activity during imagery. For SMA/PMA, there was a moderate correlation between moderate- and low force-executions and larger N2 amplitude for moderate- than for low force-executions, indicating that TF may be related to SMA/PMA electrocortical activity. ERP patterns were uncorrelated between rapid- and slow-execution at FCz, but N2 amplitude was the same, making it unclear whether the RFD parameter is represented in FCz activity. The correlational and N2 amplitude analyses demonstrate that patterns of electrocortical activity at SMA/PMA are nearly isomorphic during executed and imagined actions as TF and RFD are varied. These results provide evidence that patterns of electrocortical activity associated with variations in the parameters of executed action are similar during motor imagery at SMA/PMA but not at M1. 相似文献
120.