全文获取类型
收费全文 | 5126篇 |
免费 | 445篇 |
国内免费 | 19篇 |
专业分类
耳鼻咽喉 | 37篇 |
儿科学 | 182篇 |
妇产科学 | 100篇 |
基础医学 | 939篇 |
口腔科学 | 96篇 |
临床医学 | 525篇 |
内科学 | 1156篇 |
皮肤病学 | 80篇 |
神经病学 | 499篇 |
特种医学 | 108篇 |
外科学 | 515篇 |
综合类 | 35篇 |
一般理论 | 1篇 |
预防医学 | 554篇 |
眼科学 | 106篇 |
药学 | 314篇 |
中国医学 | 5篇 |
肿瘤学 | 338篇 |
出版年
2024年 | 10篇 |
2023年 | 52篇 |
2022年 | 73篇 |
2021年 | 122篇 |
2020年 | 98篇 |
2019年 | 127篇 |
2018年 | 131篇 |
2017年 | 124篇 |
2016年 | 125篇 |
2015年 | 144篇 |
2014年 | 152篇 |
2013年 | 218篇 |
2012年 | 384篇 |
2011年 | 401篇 |
2010年 | 200篇 |
2009年 | 172篇 |
2008年 | 298篇 |
2007年 | 334篇 |
2006年 | 280篇 |
2005年 | 280篇 |
2004年 | 325篇 |
2003年 | 276篇 |
2002年 | 256篇 |
2001年 | 85篇 |
2000年 | 87篇 |
1999年 | 79篇 |
1998年 | 56篇 |
1997年 | 41篇 |
1996年 | 39篇 |
1995年 | 31篇 |
1994年 | 29篇 |
1993年 | 28篇 |
1992年 | 65篇 |
1991年 | 47篇 |
1990年 | 34篇 |
1989年 | 45篇 |
1988年 | 38篇 |
1987年 | 35篇 |
1986年 | 25篇 |
1985年 | 37篇 |
1984年 | 24篇 |
1983年 | 25篇 |
1982年 | 16篇 |
1981年 | 9篇 |
1978年 | 8篇 |
1972年 | 15篇 |
1971年 | 19篇 |
1970年 | 10篇 |
1969年 | 8篇 |
1968年 | 11篇 |
排序方式: 共有5590条查询结果,搜索用时 15 毫秒
61.
Tatad AM Nesin M Peoples J Cheung S Lin H Sison C Perlman J Cunningham-Rundles S 《Neonatology》2008,94(1):8-15
BACKGROUND: Neonatal susceptibility to bacterial infection is associated with an immature immune system, but the role of different bacterial antigens in specific responses is largely unknown. OBJECTIVE: To evaluate differences in intracellular cytokine response to physiologically relevant bacterial antigens in term and preterm infants as compared with adults. METHODS: Cord blood samples from preterm and term neonates and adult peripheral blood samples were cultured ex vivo with and without whole heat-killed bacteria. Intracellular leukocyte production of interleukin (IL)-6, IL-10, IL-12, and IL-8 responses was assessed by flow cytometry. RESULTS: Monocytes were the primary producers of all mediators. Escherichia coli was the most potent stimulant. Lactobacillus plantarum 299v activated fewer monocytes as compared with E. coli for all responses (p < 0.05), except for IL-12 in term neonates. IL-6 response to Staphylococcus epidermidis was lower in both groups of neonates as compared with adults (p = 0.023 and p = 0.001). IL-8 response to S. epidermidis was lower in term as compared with preterm neonates and adults (p = 0.003). IL-10 response to group B streptococci was lower in term neonates as compared with adults and higher in preterm as compared with term neonates (p = 0.015). CONCLUSIONS: Monocytes from term neonates compared to preterm neonates show a downregulated anti-inflammatory response to specific bacteria. High neonatal response to pathogenic E. coli in the preterm infant could cause uncontrolled inflammatory response, while lower IL-6 response to S. epidermidis in neonates may indicate a basis for vulnerability to S. epidermidis infection. 相似文献
62.
63.
Miethbauer S Günther W Schmidtke KU Heiser I Gräfe S Gitter B Liebermann B 《Journal of natural products》2008,71(8):1371-1375
Both the phytopathogenic fungus Ramularia collo-cygni and the hyperparasite R. uredinicola biosynthesize a number of red and yellow anthraquinone derivatives called rubellins. The new compounds uredinorubellins I and II, which were isolated from R. uredinicola, contribute to understanding the biosynthesis pathway that leads from simple anthraquinones to the rubellins. In addition, we isolated for the first time such simple compounds as chrysophanol and helminthsporin from both Ramularia species. A blue compound isolated from the mycelium of R. collo-cygni was revealed to be a unique 9,4-anthracenedione derivative. Structure elucidation by (1)H and (13)C NMR of the new but unstable compound caeruleoramularin was possible only by feeding the fungus different labeled (13)C acetates. The photodynamic activity of the uredinorubellins was comparable to rubellin D, whereas chrysophanol and caeruleoramularin did not display such activity. 相似文献
64.
Bolignano D Coppolino G Crascì E Campo S Aloisi C Buemi M 《The journal of obstetrics and gynaecology research》2008,34(2):137-143
Renal damage, which can be caused by gestational anomalies such as pre-eclampsia, carries a risk of gestational complications; the greatest risk being in women who become pregnant while on hemodialysis or peritoneal dialysis. If this rare event occurs, there is a marked increase in the risk of pre-eclampsia, early uterine contractions and hydramnios, hypertensive crisis, preterm delivery and intrauterine growth retard. Furthermore, newborns are almost always of low birthweight. Patients who undergo renal transplantation are another high-risk category. In such cases, the pregnancy itself can compromise the success of the transplant and the immunosuppressive therapy correlated to it can become a threat to the course of the pregnancy and normal fetal growth. Therefore, in view of the lack of appropriate guidelines for the best possible approach to the treatment of women on dialysis or of those with a renal transplantation, it is best to advise these patients against becoming pregnant and/or to provide a valid counselling service illustrating the extreme difficulties and dangers involved in becoming pregnant. 相似文献
65.
Fullerene derivatives: an attractive tool for biological applications 总被引:24,自引:0,他引:24
The fullerene family, and especially C60, has very appealing photo-, electro-chemical and physical properties, which can be exploited in many and different biological fields. Fullerene is able to fit inside the hydrophobic cavity of HIV proteases, inhibiting the access of substrates to the catalytic site of the enzyme. It can be used as radical scavenger; in fact some water-soluble derivatives are able to reduce ROS concentrations. At the same time, if exposed to light, fullerene can produce singlet oxygen in high quantum yields. This action, together with the direct electron transfer from excited state of fullerene and DNA bases, can be used to cleave DNA. In this review we report the most recent aspects of fullerene biological applications. 相似文献
66.
67.
Gastrointestinal stromal tumors in patients with neurofibromatosis: imaging features with clinicopathologic correlation 总被引:6,自引:0,他引:6
Levy AD Patel N Abbott RM Dow N Miettinen M Sobin LH 《AJR. American journal of roentgenology》2004,183(6):1629-1636
OBJECTIVE: The purpose of this study was to evaluate the clinical, pathologic, and imaging features of gastrointestinal stromal tumors that occur in patients with neurofibromatosis. CONCLUSION: Gastrointestinal stromal tumors that occur in patients with neurofibromatosis commonly originate from the proximal small intestine and are often multiple. The cross-sectional imaging appearance of gastrointestinal stromal tumors that occur in patients with neurofibromatosis is similar to that of gastrointestinal stromal tumors that occur in the general population. 相似文献
68.
We leveraged genetic variants associated with caffeine metabolism in the two-sample Mendelian randomization framework to investigate the effect of plasma caffeine levels on the risk of Alzheimer’s disease and Parkinson’s disease. Genetic association estimates for the outcomes were obtained from the International Genomics of Alzheimer’s Project, the International Parkinson’s Disease Genomics consortium, the FinnGen consortium, and the UK Biobank. Genetically predicted higher plasma caffeine levels were associated with a non-significant lower risk of Alzheimer’s disease (odds ratio 0.87; 95% confidence interval 0.76, 1.00; p = 0.056). A suggestive association was observed for genetically predicted higher plasma caffeine levels and lower risk of Parkinson’s disease in the FinnGen consortium. but not in the International Parkinson’s Disease Genomics consortium; no overall association was found (odds ratio 0.92; 95% confidence interval 0.77, 1.10; p = 0.347). This study found possible suggestive evidence of a protective role of caffeine in Alzheimer’s disease. The association between caffeine and Parkinson’s disease requires further study. 相似文献
69.
Leonora W. de Boo Katarzyna J
wiak Heikki Joensuu Henrik Lindman Susanna Lauttia Mark Opdam Charlaine van Steenis Wim Brugman Roelof J. C. Kluin Philip C. Schouten Marleen Kok Petra M. Nederlof Michael Hauptmann Sabine C. Linn 《British journal of cancer》2022,126(10):1401
Background The addition of adjuvant capecitabine to standard chemotherapy of early-stage triple-negative breast cancer (TNBC) patients has improved survival in a few randomised trials and in meta-analyses. However, many patients did not benefit. We evaluated the BRCA1-like DNA copy number signature, indicative of homologous recombination deficiency, as a predictive biomarker for capecitabine benefit in the TNBC subgroup of the FinXX trial.Methods Early-stage TNBC patients were randomised between adjuvant capecitabine-containing (TX + CEX: capecitabine-docetaxel, followed by cyclophosphamide-epirubicin-capecitabine) and conventional chemotherapy (T + CEF: docetaxel, followed by cyclophosphamide-epirubicin-fluorouracil). Tumour BRCA1-like status was determined on low-coverage, whole genome next-generation sequencing data using an established DNA comparative genomic hybridisation algorithm.Results For 129/202 (63.9%) patients the BRCA1-like status could be determined, mostly due to lack of tissue. During a median follow-up of 10.7 years, 35 recurrences and 32 deaths occurred. Addition of capecitabine appears to improve recurrence-free survival more among 61 (47.3%) patients with non-BRCA1-like tumours (HR 0.23, 95% CI 0.08–0.70) compared to 68 (52.7%) patients with BRCA1-like tumours (HR 0.66, 95% CI 0.24–1.81) (P-interaction = 0.17).Conclusion Based on our data, patients with non-BRCA1-like TNBC appear to benefit from the addition of capecitabine to adjuvant chemotherapy. Patients with BRCA1-like TNBC may also benefit. Additional research is needed to define the subgroup within BRCA1-like TNBC patients who may not benefit from adjuvant capecitabine.Subject terms: Breast cancer, Translational research, Predictive markers, Breast cancer 相似文献
70.
Filippo Monelli Francesco Venturelli Lisa Bonilauri Elisa Manicardi Valeria Manicardi Paolo Giorgi Rossi Marco Massari Guido Ligabue Nicoletta Riva Susanna Schianchi Efrem Bonelli Pierpaolo Pattacini Maria Chiara Bassi Giulia Besutti 《肝癌研究(英文版)》2021,7(4):13-24
Aim: In this systematic review, guidelines on non-alcoholic fatty liver disease (NAFLD) were evaluated, aiming at a guideline synthesis focusing on diagnosis an... 相似文献