全文获取类型
收费全文 | 1093篇 |
免费 | 62篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 6篇 |
妇产科学 | 12篇 |
基础医学 | 147篇 |
口腔科学 | 14篇 |
临床医学 | 109篇 |
内科学 | 365篇 |
皮肤病学 | 11篇 |
神经病学 | 89篇 |
特种医学 | 26篇 |
外科学 | 240篇 |
综合类 | 5篇 |
预防医学 | 31篇 |
眼科学 | 13篇 |
药学 | 55篇 |
肿瘤学 | 37篇 |
出版年
2023年 | 17篇 |
2022年 | 30篇 |
2021年 | 58篇 |
2020年 | 19篇 |
2019年 | 29篇 |
2018年 | 38篇 |
2017年 | 17篇 |
2016年 | 22篇 |
2015年 | 32篇 |
2014年 | 41篇 |
2013年 | 56篇 |
2012年 | 81篇 |
2011年 | 90篇 |
2010年 | 49篇 |
2009年 | 40篇 |
2008年 | 72篇 |
2007年 | 55篇 |
2006年 | 53篇 |
2005年 | 53篇 |
2004年 | 59篇 |
2003年 | 45篇 |
2002年 | 37篇 |
2001年 | 21篇 |
2000年 | 18篇 |
1999年 | 18篇 |
1997年 | 3篇 |
1996年 | 7篇 |
1995年 | 4篇 |
1991年 | 3篇 |
1989年 | 4篇 |
1988年 | 4篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 7篇 |
1983年 | 3篇 |
1981年 | 2篇 |
1980年 | 3篇 |
1979年 | 3篇 |
1978年 | 8篇 |
1977年 | 2篇 |
1976年 | 3篇 |
1975年 | 3篇 |
1974年 | 5篇 |
1972年 | 3篇 |
1971年 | 3篇 |
1970年 | 7篇 |
1969年 | 6篇 |
1968年 | 4篇 |
1967年 | 4篇 |
排序方式: 共有1169条查询结果,搜索用时 15 毫秒
61.
Ioana Mihaela Citu Cosmin Citu Florin Gorun Ioan Sas Larisa Tomescu Radu Neamtu Andrei Motoc Oana Maria Gorun Bogdan Burlea Felix Bratosin Daniel Malita 《Viruses》2022,14(2)
Globally, COVID-19 vaccines are currently being used to prevent transmission and to reduce morbidity and death associated with SARS-CoV-2 infection. Current research reveals that vaccines such as BNT162b2 and Ad26.COV2.S are highly immunogenic and have high short-term effectiveness for most of the known viral variants. Clinical trials showed satisfying results in the general population, but the reluctance in testing and vaccinating pregnant women left this category with little evidence regarding the safety, efficacy, and immunogenicity following COVID-19 vaccination. With the worldwide incidence of COVID-19 remaining high and the possibility of new transmissible SARS-CoV-2 mutations, data on vaccination effectiveness and antibody dynamics in pregnant patients are critical for determining the need for special care or further booster doses. An observational study was developed to evaluate pregnant women receiving the complete COVID-19 vaccination scheme using the BNT162b2 and Ad26.COV2.S, and determine pregnancy-related outcomes in the mothers and their newborns, as well as determining adverse events after vaccination and immunogenicity of vaccines during four months. There were no abnormal findings in pregnancy and newborn characteristics comparing vaccinated versus unvaccinated pregnant women. COVID-19 seropositive pregnant women had significantly higher spike antibody titers than seronegative patients with similar characteristics, although they were more likely to develop fever and lymphadenopathy following vaccination. The same group of pregnant women showed no statistically significant differences in antibody titers during a 4-month period when compared with case-matched non-pregnant women. The BNT162b2 and Ad26.COV2.S vaccines are safe to administer during the third trimester of pregnancy, while their safety, efficacy, and immunogenicity remain similar to those of the general population. 相似文献
62.
Adelina Silvana Gheorghe erban Mircea Negru Mdlina Preda Raluca Ioana Mihil Isabela Anda Komporaly Elena Adriana Dumitrescu Cristian Virgil Lungulescu Lidia Anca Kajanto Bogdan Georgescu Emanuel Alin Radu Dana Lucia Stnculeanu 《Nutrients》2022,14(6)
Knowledge regarding the influence of the microbial community in cancer promotion or protection has expanded even more through the study of bacterial metabolic products and how they can modulate cancer risk, which represents an extremely challenging approach for the relationship between intestinal microbiota and colorectal cancer (CRC). This review discusses research progress on the effect of bacterial dysbiosis from a metabolic point of view, particularly on the biochemical mechanisms of butyrate, one of the main short chain fatty acids (SCFAs) with anti-inflammatory and anti-tumor properties in CRC. Increased daily intake of omega-3 polyunsaturated fatty acids (PUFAs) significantly increases the density of bacteria that are known to produce butyrate. Omega-3 PUFAs have been proposed as a treatment to prevent gut microbiota dysregulation and lower the risk or progression of CRC. 相似文献
63.
Manuela G. Neuman Loida Oruña Gabriel Coto Guillermo Lago Radu Nanau Marc Vincent 《Clinical biochemistry》2010,43(10-11):822-826
Ethanol is commonly used in cosmetic and pharmaceutical preparations.ObjectiveThe present study aimed to assess ethanol-induced apoptosis and the possible repair by hyaluronic acid (HA) in vitro. In addition we aimed to determine the modulation of tumor necrosis factor (TNF-α) and interferon (IFN-α).Design and methodsWe treated human A431 epidermoid skin cells and mouse fibroblasts with two concentrations of ethanol for 24 h. HA obtained from umbilical cord excision was used at three concentration levels (2%, 4% and 8%) to determine its efficacy in the treatment. We measured cytotoxicity, TNF-α and IFN-α and visualized the cultures by electron microscopy.ResultsTreatment of cells with ethanol at 50 mM and 100 mM increased both the percentage of cells undergoing apoptosis, as well as the release of TNF-α into the culture medium.ConclusionsEthanol may induce apoptosis in skin cells by enhancing the effects of TNF-α. HA in the 2% and 4% concentrations reduced TNF-α and morphological inflammation both in human A431 epidermoid skin cells and in mouse fibroblasts. 相似文献
64.
65.
Diego Penela Cheryl Teres Juan Fernández-Armenta Luis Aguinaga Luis Tercedor David Soto-Iglesias Beatriz Jauregui Augusto Ordóñez Juan Acosta Felipe Bisbal Marta Aceña Etelvino Silva Alfredo Chauca Francesco De Sensi Radu Vatasescu Pablo Sánchez-Millán Julio Carballo Lluis Mont Antonio Berruezo 《Heart rhythm》2021,18(1):27-33
66.
67.
The hamartomatous polyps in Peutz-Jeghers syndrome may have malignant potential. To differentiate between hamartomatous and adenomas polyps, vascular characterization can be assessed using noninvasive procedures, such as contrast-enhanced ultrasound (CEUS). The neo-angiogenic characteristics of colorectal adenomas and carcinomas are expressed as an anarchic vascular pattern observed on CEUS. Using CEUS in a patient with Peutz-Jeghers syndrome, we describe for the first time the vascularization of a hamartomatous colonic polyp that exhibits a hierarchy branching pattern. 相似文献
68.
Michael J. Stechman Mary Weisters Fergus V. Gleeson† Gregory P. Sadler Radu Mihai 《Clinical endocrinology》2009,71(6):787-791
Objective Parathyroidectomy for primary hyperparathyroidism (PHPT) is curative in over 95% of cases. Although PHPT affects up to 2% of the elderly population, whose life expectancy may be a decade or more, such patients may be denied surgery because of perceived risk. This study investigates the outcomes of surgery for PHPT in the elderly. Design and patients Consecutive patients with PHPT treated at a tertiary referral centre over 5 years. Measurements A prospective database recorded clinical, biochemical and pathological information. Pasieka’s parathyroid symptom scores were obtained pre‐operatively and post‐operatively, from a recent subgroup of 70 consecutive patients. Deaths during follow‐up were identified using the NHS Strategic Tracing Service. Statistical analysis was performed with spss v12.0. Results Between November 2002 and October 2007, 224 patients (17–89 years) underwent surgery for PHPT. In the subgroup comprising patients aged >75 years there was a significantly greater proportion of women (47/56 vs. 52/81, P < 0·05). Pre‐operative indices of these patients were similar to younger patients, as were proportions undergoing minimally invasive parathyroidectomy (n = 134) or bilateral neck exploration (n = 90). Patients >75 years had a longer hospital stay (1·6 vs. 0·8 days, P = 0·003). Pasieka’s symptom scores improved significantly at 3–6 months postoperatively in all age groups. During a minimum median follow‐up of 22 months, there were seven patients with persistent/recurrent disease. Median 2‐year survival of those aged 60–74 and those over 75 ranged from 85–90%. Conclusion Parathyroidectomy is safe in the elderly and is associated with a significant improvement in symptoms. As survival after operation is similar to younger patients, surgery should be considered in all elderly patients with PHPT. 相似文献
69.
70.
The importance of erythroid expansion in determining the extent of apoptosis in erythroid precursors in patients with beta-thalassemia major 总被引:3,自引:1,他引:2
Centis F Tabellini L Lucarelli G Buffi O Tonucci P Persini B Annibali M Emiliani R Iliescu A Rapa S Rossi R Ma L Angelucci E Schrier SL 《Blood》2000,96(10):3624-3629
Beta-thalassemia major is characterized by ineffective erythropoiesis leading to severe anemia and extensive erythroid expansion. The ineffective erythropoiesis is in part due to accelerated apoptosis of the thalassemic erythroid precursors; however, the extent of apoptosis is surprisingly variable. To understand this variability as well as the fact that some patients undergoing allogeneic marrow transplantation are resistant to the myeloablative program, we attempted more quantitative analyses. Two groups of patients totaling 44 were studied, along with 25 healthy controls, and 7 patients with hemolysis and/or ineffective erythropoeisis. By 2 flow cytometric methods, thalassemic erythroid precursors underwent apoptosis at a rate that was 3 to 4 times normal. Because thalassemic marrow has between 5- to 6-fold more erythroid precursors than healthy marrow, this translated into an absolute increase in erythroid precursor apoptosis of about 15-fold above our healthy controls. In searching for the causes of the variability in thalassemic erythroid precursor apoptosis, we discovered tight direct correlations between the relative and absolute extent of apoptosis and the extent of erythroid expansion as measured either by the absolute number of marrow erythroid precursors or by serum soluble transferrin receptor levels. These results could mean that the most extreme rates of erythroid proliferation lend themselves to cellular errors that turn on apoptotic programs. Alternatively, extreme rates of erythroid hyperplasia and apoptosis might be characteristic of more severely affected patients. Lastly, extreme erythroid hyperplasia could generate such numbers of apoptotic erythroid precursors that marrow macrophages are overwhelmed, leaving more apoptotic cells in the sample. 相似文献