全文获取类型
收费全文 | 12735篇 |
免费 | 750篇 |
国内免费 | 53篇 |
专业分类
耳鼻咽喉 | 183篇 |
儿科学 | 358篇 |
妇产科学 | 293篇 |
基础医学 | 1652篇 |
口腔科学 | 452篇 |
临床医学 | 942篇 |
内科学 | 3133篇 |
皮肤病学 | 253篇 |
神经病学 | 1124篇 |
特种医学 | 380篇 |
外科学 | 1723篇 |
综合类 | 59篇 |
预防医学 | 1045篇 |
眼科学 | 244篇 |
药学 | 879篇 |
中国医学 | 52篇 |
肿瘤学 | 766篇 |
出版年
2023年 | 86篇 |
2022年 | 189篇 |
2021年 | 419篇 |
2020年 | 219篇 |
2019年 | 341篇 |
2018年 | 435篇 |
2017年 | 286篇 |
2016年 | 312篇 |
2015年 | 331篇 |
2014年 | 489篇 |
2013年 | 617篇 |
2012年 | 878篇 |
2011年 | 980篇 |
2010年 | 583篇 |
2009年 | 468篇 |
2008年 | 738篇 |
2007年 | 758篇 |
2006年 | 709篇 |
2005年 | 703篇 |
2004年 | 636篇 |
2003年 | 572篇 |
2002年 | 491篇 |
2001年 | 214篇 |
2000年 | 240篇 |
1999年 | 221篇 |
1998年 | 129篇 |
1997年 | 93篇 |
1996年 | 73篇 |
1995年 | 74篇 |
1994年 | 74篇 |
1993年 | 54篇 |
1992年 | 110篇 |
1991年 | 79篇 |
1990年 | 88篇 |
1989年 | 90篇 |
1988年 | 70篇 |
1987年 | 65篇 |
1986年 | 54篇 |
1985年 | 58篇 |
1984年 | 44篇 |
1983年 | 49篇 |
1980年 | 23篇 |
1979年 | 31篇 |
1978年 | 28篇 |
1976年 | 23篇 |
1975年 | 25篇 |
1974年 | 31篇 |
1973年 | 25篇 |
1971年 | 23篇 |
1970年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 9 毫秒
21.
22.
23.
Treatment of Status Epilepticus in Adults: Guidelines of the Italian League Against Epilepsy 总被引:2,自引:1,他引:1
Fabio Minicucci †Giancarlo Muscas ‡Emilio Perucca §Giuseppe Capovilla Federico Vigevano ¶Paolo Tinuper 《Epilepsia》2006,47(S5):9-15
Summary: Status epilepticus (SE) is a medical emergency which can lead to significant morbidity and mortality and requires prompt diagnosis and treatment. SE is differentiated into generalized or partial SE on the basis of its electro-clinical manifestations. The guidelines for the management of SE produced by the Italian League against Epilepsy also distinguish three different stages of SE (initial, established and refractory), based on time elapsed since the onset of the condition and responsiveness to previously administered drugs. Treatment should be started as soon as possible, particularly in generalized convulsive SE, and should include general support measures, drugs to suppress epileptic activity and, whenever possible, treatments aimed at relieving the underlying (causative) condition. Benzodiazepines are the first line antiepileptic agents, and i.v. lorazepam is generally preferred because it is associated with a lower risk of early relapses. If benzodiazepines fail to control seizures, i.v. phenytoin is usually indicated, though i.v. phenobarbital or i.v. valproate may also be considered. Refractory SE requires admission to an intensive care unit (ICU) to allow adequate monitoring and support of respiratory, metabolic and hemodynamic functions and cerebral electrical activity. In refractory SE, general anesthesia may be required. Propofol and thiopental represent first line agents in this setting, after careful assessment of potential risks and benefits. 相似文献
24.
M de la Hera A de la Hera A Ramos L Buelta J L Alonso V Rodriguez-Valverde J Merino 《International immunology》1992,4(1):67-74
BALB/c mice injected at birth with 10(8) semi-allogeneic (C57BL/6 x BALB.IgHb)F1 spleen cells develop a lupus-like syndrome in which autoantibodies bear exclusively the donor allotype. We have analyzed the evolution of donor B cell chimerism and the autoimmune manifestations during the first year of life in these mice. Anti-DNA, -histone, and -cardiolipin IgG antibodies as well as circulating immune complexes appeared in the second week of life, reached the highest values around the sixth week, and then progressively dropped to normal values after the sixth month in most mice. The kinetics of the evolution of the autoimmune manifestations, as well as the kinetics of serum donor Ig allotype, were parallel to the kinetics of donor B cell chimerism, which was particularly prominent in the spleens in early weeks of life, and progressively decreased after remission of the autoimmune syndrome. Membrane-proliferative glomerulonephritis, which was followed as the more representative histological abnormality in this model, was particularly evident after 10 weeks of life, but disappeared by the end of the follow-up. Interestingly, when mice with a self-limited disease were re-injected with 10(8) F1 spleen cells i.v., a flare in the serological manifestations was observed. In these re-injected mice a predominance of anti-DNA, IgG1 antibodies bearing exclusively the donor allotype was also observed, as in the early weeks of life.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
25.
E. J. Ramos H. S. Pollinger M. D. Stegall J. M. Gloor A. Dogan J. P. Grande 《American journal of transplantation》2007,7(2):402-407
Rituximab, intravenous immunoglobulin (IVIG) and rabbit antithymocyte globulin (rATG) all have been suggested to have an effect on antibody producing cells, however, supporting data are lacking. To assess the impact of these agents on splenic B‐cell populations in vivo, we retrospectively examined 25 spleens removed from patients treated with these agents as part of desensitization protocols in either ABO incompatible or positive crossmatch living donor kidney transplantation. These were compared to control (CTL) spleens removed for trauma. CTLs and spleens removed at transplant after multiple pretransplant plasmaphereses (PP) plus low‐dose IVIG showed similar large numbers of naïve B cells (CD20+ and CD79+), plasma cells (CD138+) and memory B cells (CD27+ cells). Adding rituximab to this PP/IVIG regimen reduced the number naïve B cells, but had no effect on memory or plasma cells. Combination treatment (PP/IVIG, rituximab and rATG) showed a trend toward the reduction of CD27+ cells, but again plasma cells were unchanged. We conclude that none of these protocols reduces splenic plasma cells in vivo. PP/low‐dose IVIG does not alter splenic B cells, but the addition of rituximab decreases mature B cells. Memory B cells may be affected by combination therapy including rATG and requires further study. 相似文献
26.
Dalton A Anjos Elba C S C Etchebehere Celso D Ramos Allan O Santos César Albertotti Edwaldo E Camargo 《Journal of nuclear medicine》2007,48(5):764-770
PET with (18)F-FDG has been considered of limited value for detection of bladder cancer because of the urinary excretion of the tracer. The purpose of this study was to investigate the role of PET/CT in the detection and restaging of bladder cancer using furosemide and oral hydration to remove the excreted (18)F-FDG from the bladder. METHODS: Seventeen patients with bladder cancer (11 without cystectomy, 6 with total cystectomy and urinary diversion) underwent (18)F-FDG PET/CT from head to the upper thighs 60 min after the intravenous injection of 370 MBq of (18)F-FDG. Additional pelvic images were acquired 1 h after the intravenous injection of furosemide and oral hydration. PET/CT findings were confirmed by MRI, cystoscopy, or biopsy. RESULTS: PET/CT was able to detect bladder lesions in 6 of 11 patients who had not undergone cystectomy. These images changed the PET/CT final reading in 7 patients: Recurrent bladder lesions were detected in 6 patients, pelvic lymph node metastases in 2 patients, and prostate metastasis in 1. This technique overcame the difficulties posed by the urinary excretion of (18)F-FDG. Hypermetabolic lesions could be easily detected by PET and precisely localized in the bladder wall, pelvic lymph nodes, or prostate by CT. Seven of 17 patients (41%) were upstaged only after delayed pelvic images. CONCLUSION: Detection of locally recurrent or residual bladder tumors can be dramatically improved using (18)F-FDG PET/CT with delayed images after a diuretic and oral hydration. 相似文献
27.
CD24 expression on human keratinocytes 总被引:4,自引:0,他引:4
Pedro Redondo Jesús García-Foncillas Iouri Okroujnov Iñigo de Felipe Emilio Quintanilla 《Experimental dermatology》1998,7(4):175-178
Abstract: CD24 or Nectadrin is a cell surface glycoprotein expressed in pre-B lymphocytes, T lymphocytes, neurons, muscle cells and carcinoma cells. Its function is not completely known, but it has been suggested that it is involved in cell adhesion and signalling. CD24 has recently been identified as the human molecule homologous to the murine heat-stable antigen (HSA). HSA is expressed by murine keratinocytes and delivers costimulatory signals in T-cell activation. Long-term cultures of normal human keratinocytes (HKC) were obtained from skin of human female breast sections and either left untreated or were treated with phorbol-12-myristate-13-acetate (PMA) at 10–100 ng/ml, calcium 0.5–2 mM or IFN-γ 100–1000 U/ml, for 24–48 h. Using RT-PCR and flow cytometry we showed that HKC express low levels of CD24 even under basal conditions, and the treatment with calcium, PMA or IFN-γ increased levels of CD24 mRNA and protein. To the best of our knowledge, this is the first report to measure CD24 expression and production by cultured HKC in basal conditions and after stimulation. Further studies are needed to determine biological and therapeutical relevance of these findings. 相似文献
28.
F. Oner L. Ramos R. Simmermacher P. Kingma C. Diekerhof W. Dhert A. Verbout 《European spine journal》2002,11(3):235-245
Reproducibility of fracture classification systems in general has been a matter of controversy. The reproducibility of spinal fracture classifications has not been sufficiently studied. We studied the inter-observer and intra-observer reproducibility of the Magerl (AO) classification using radiograms, CTs and MRIs of 53 patients. We compared this classification with the older and simpler Denis classification. Five observers classified the fractures, first using the radiograms and CTs and, 6 weeks later, with radiograms and MRIs. Three of the observers repeated the readings after 3 months. Three observers also classified the fractures according to Denis. Agreement was measured using Cohen's kappa test. The type (A, B, C) classification of the AO system was fairly reproducible with CTs. With MRI this was only moderate. Group subclassification of the types yielded higher kappa values, corresponding to substantial agreement. The agreement was, in general, better with the Denis classification, but the variance was higher due to the difficulty of finding proper categories for some injury patterns. Although the AO classification allows proper registration of all kinds of injury, the reproducibility, especially at the type level, is problematic. Use of MRI and better definition of the distinctive properties of the three different types may enhance the reproducibility of the scheme. 相似文献
29.
Effect of elevated prolactin levels on the synthesis and release of catecholamines from the adrenal medulla in female rats 总被引:1,自引:0,他引:1
J Fernandez-Ruiz M Cebeira C Agrasal J A Tresguerres A I Esquifino J A Ramos 《Neuroendocrinology》1987,45(3):208-211
Recent evidence suggests that increased plasma prolactin (PRL) levels could be modifying the synthesis and release of catecholamines (CA) from the adrenal medulla. In order to study this possibility, female rats bearing an anterior pituitary gland, from a litter-mate donor, under the right kidney capsule since day 30 of life and their sham-operated controls were sacrificed by decapitation 45 days after the transplant operation. Plasma PRL and CA levels and CA content in the adrenal medulla were analyzed. A significant increase in plasma PRL levels was shown in grafted (22 +/- 2 micrograms/l) when compared to control rats (6 +/- 0.3 micrograms/l), together with a significant increase in plasma norepinephrine (NE) (4.2 +/- 1.1 micrograms/l vs. 1.7 +/- 0.7 micrograms/l) and epinephrine (E) (2.9 +/- 0.6 micrograms/l vs. 1.6 +/- 0.2 micrograms/l). Similar plasma dopamine (DA) levels were found in both groups (0.6 +/- 0.2 micrograms/l vs. 0.8 +/- 0.3 micrograms/l). An increase in adrenal DA content (29.1 +/- 6.8 ng/mg protein), together with a decrease in NE (33.3 +/- 6.8 ng/mg protein) and E content (65.9 +/- 11.8 ng/mg protein) was detected in grafted as compared to control rats (DA: 12.0 +/- 3.6 ng/mg protein; NE: 79.3 +/- 22.1 ng/mg protein; E: 184.2 +/- 39.2 ng/mg protein). We can conclude from these data that the elevation of circulating PRL levels induced by a pituitary graft is able to increase the synthesis and release of CA from the adrenal medulla in female rats. 相似文献
30.
Antonio Cuadrado Emilio Fábrega Fernando Casafont Fernando Pons-Romero 《Liver transplantation》2005,11(4):420-426
The aim of this study was to evaluate the rate of alcohol recidivism after orthotopic liver transplantation (OLT) for alcoholic liver disease (ALD) and its influence on the allograft and patient survival, as well as the development of comorbidities and de novo cancers. The study was performed on 54 subjects previously analyzed and transplanted in our center for ALD, whose follow-up was prolonged to a mean of 99.2 (SD 31.7) months (range, 14-155). Medical records were reviewed, and data on alcohol consumption, therapeutic compliance, graft evolution, rejection, infections, comorbidities, rates of de novo malignancies and other clinical events, and survival were collected. Comparisons between groups were performed by the Fisher's exact test, and survival was assessed by the Kaplan-Meier method. Survival curves were compared using the Mantel-Cox statistic. The risk of death resulting from alcohol recidivism was analyzed with a Cox proportional hazards model. Fourteen patients who underwent transplantation for ALD (25.9%) returned to alcohol use between 5.0 and 86.9 months after OLT (median, 47.5). There was no significant association between the presence or absence of alcohol recidivism and the occurrence of graft rejection, infections, associated comorbidities after OLT, or compliance. The 5- and 10-year survival rates for patients with alcohol recidivism were 92.9% and 45.1%, respectively, compared with 92.4% and 85.5%, respectively, for patients without alcohol recidivism. These figures show significantly lower survival rates in recidivistic patients after 10 years (P < 0.01, Mantel-Cox). The fact that patients who resumed alcohol consumption have a worse 10-year survival rate might be attributed to a higher frequency of deaths, primarily from cancer and cardiovascular events. 相似文献