全文获取类型
收费全文 | 1440篇 |
免费 | 111篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 137篇 |
妇产科学 | 35篇 |
基础医学 | 215篇 |
口腔科学 | 36篇 |
临床医学 | 165篇 |
内科学 | 306篇 |
皮肤病学 | 19篇 |
神经病学 | 83篇 |
特种医学 | 161篇 |
外科学 | 135篇 |
综合类 | 23篇 |
预防医学 | 60篇 |
眼科学 | 7篇 |
药学 | 89篇 |
中国医学 | 1篇 |
肿瘤学 | 76篇 |
出版年
2021年 | 20篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 21篇 |
2017年 | 19篇 |
2016年 | 16篇 |
2015年 | 19篇 |
2014年 | 33篇 |
2013年 | 39篇 |
2012年 | 44篇 |
2011年 | 38篇 |
2010年 | 50篇 |
2009年 | 49篇 |
2008年 | 58篇 |
2007年 | 49篇 |
2006年 | 65篇 |
2005年 | 58篇 |
2004年 | 58篇 |
2003年 | 56篇 |
2002年 | 59篇 |
2001年 | 60篇 |
2000年 | 56篇 |
1999年 | 50篇 |
1998年 | 44篇 |
1997年 | 49篇 |
1996年 | 56篇 |
1995年 | 42篇 |
1994年 | 36篇 |
1993年 | 48篇 |
1992年 | 28篇 |
1991年 | 20篇 |
1990年 | 32篇 |
1989年 | 26篇 |
1988年 | 23篇 |
1987年 | 31篇 |
1986年 | 38篇 |
1985年 | 15篇 |
1984年 | 15篇 |
1983年 | 8篇 |
1982年 | 21篇 |
1981年 | 7篇 |
1980年 | 9篇 |
1979年 | 4篇 |
1977年 | 10篇 |
1976年 | 9篇 |
1975年 | 9篇 |
1974年 | 4篇 |
1973年 | 3篇 |
1972年 | 6篇 |
1970年 | 4篇 |
排序方式: 共有1557条查询结果,搜索用时 15 毫秒
1.
D Gröne† R Treudler† EM de Villiers‡ R Husak† CE Orfanos† ChC Zouboulis†§ 《Journal of the European Academy of Dermatology and Venereology》2006,20(2):202-205
Cidofovir is an acyclic nucleoside phosphonate with broad-spectrum activity against DNA viruses, including human papilloma virus (HPV). However, data on the efficacy of cidofovir in an immunosuppressive setting remain contradictory. We report for the first time on the promotion of the healing of recalcitrant warts in a patient with myelodysplastic syndrome with intravenous cidofovir treatment. 相似文献
2.
C E Hack J Wagstaff R J Strack van Schijndel A J Eerenberg H M Pinedo L G Thijs J H Nuijens 《Thrombosis and haemostasis》1991,65(5):497-503
Patients treated with high doses of interleukin-2 (IL-2) because of cancer, develop hemodynamic and vasopermeability changes, that resemble those observed in sepsis. These patients thus provide a unique opportunity to study the early events in the development of septic shock. We analysed the changes that occurred in the contact system of coagulation in plasma from 4 patients, who together received seven 12-day cycles of high doses of IL-2. Levels of factor XII and prekallikrein during the cycles progressively fell to 50 and 30% of their initial levels, respectively, whereas significant increases in plasma factor XIIa- and kallikrein-C1-inhibitor complexes were not observed (in 3 out of 211 samples slightly increased levels of both complexes were found). The reductions in factor XII and prekallikrein were only in part due to protein leakage, since levels were still significantly lower, i.e., 80 and 50%, respectively, when corrected for albumin decreases. Levels of high molecular weight kininogen (HMWK) also decreased during IL-2 therapy, however, this decrease paralleled that of albumin. SDS-PAGE analysis of plasma HMWK did not reveal increased cleavage of this protein. The reduction of factor XII and prekallikrein, corrected for protein leakage, significantly correlated with albumin levels and inversely with daily cumulative weight gain in the patients. Thus, we demonstrate that factor XII and prekallikrein decrease during IL-2 therapy. As these decreases, already observed after 1 day treatment, were disproportional to that of albumin, a negative acute phase reactant, and correlated with signs of the vascular leak syndrome, we favor the explanation that they reflected activation rather than a decreased synthesis of the contact system proteins.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
3.
The reliability and validity of two tests (cold water and reactive hyperaemia) designed to confirm a patient's history of vibration induced white finger were studied. The cold water test is a measure of digital rewarming after hand immersion in cold water. Reactive hyperaemia consists of measuring digital rewarming after cold water immersion plus temporary ischaemia imposed on the hand. For ten weeks, ten healthy male volunteers were submitted once a week to both tests to study their reliability. The results showed a strong inter and intraindividual scattering. The mean value for the whole group, however, did not differ significantly from one week to the next. Fifty two subjects exposed to hand/arm vibration were submitted to both tests to estimate their validity. They were classified, according to their medical history, into three groups: A = no symptoms, B = tingling or numbess, or both, C = Raynaud's phenomenon. Both tests agreed with the clinical staging. For reactive hyperaemia, however, the differences between the groups were statistically significant only when the test was performed at 10 degrees C. These tests are more useful to study a group than an individual case. Time has no significant effect on the mean result of a group. 相似文献
4.
5.
6.
This paper reviews the results of toxicity studies conducted in laboratory animals to evaluate the safety of the herbicide trifluralin (TFL). The data show that TFL is slightly toxic following single oral exposure. Testing for embryotoxicity in rats and rabbits indicated no teratogenic potential, and many different mutagenicity tests showed that TFL was non-genotoxic. Subchronic and chronic toxicity testing in rats, mice and dogs indicated that TFL was haematotoxic (anaemia and methaemoglobinaemia), particularly in the dog, and slightly hepatotoxic. No-observed-effect levels of 4.8 and 41 mg/kg body weight/day, respectively, were determined in dogs and rats exposed chronically to TFL. Oncogenicity studies in rats and mice revealed no carcinogenic potential. Since the data for TFL indicated no mutagenic or other special toxicological risks, it is suggested that a safety factor of 100 could be used for the determination of the acceptable daily intake of TFL, which would be 0.05 mg/kg body weight/day. 相似文献
7.
Digital radiography of subtle pulmonary abnormalities: an ROC study of the effect of pixel size on observer performance 总被引:3,自引:0,他引:3
Forty conventional radiographs with examples of mild interstitial infiltrates and subtle pneumothoraces and 40 normal studies of the chest were selected and digitized, with pixel sizes of 1.0, 0.5, 0.2, and 0.1 mm. Observer performance tests were carried out using receiver operating characteristic analysis. Conventional radiographs and digitized images were compared. The results indicate that, in such cases, diagnostic accuracy increases significantly as the pixel size is reduced, at least to the 0.1-mm level. We conclude that, for digital systems using screen-film or similar image receptors, use of a pixel size substantially larger than 0.1 mm may result in some loss of diagnostic accuracy. 相似文献
8.
9.
J P de Boer G J Wolbink L G Thijs J W Baars J Wagstaff C E Hack 《Immunopharmacology》1992,24(2):135-148
Sepsis is a clinical syndrome that is usually induced by bacterial infections. It is generally assumed that the syndrome results from an excessive triggering of endogenous inflammatory mediators by the invading microorganisms. These mediators include substances released by activated monocytes, macrophages, endothelial cells and neutrophils such as cytokines, reactive oxygen species and proteases, as well as activation products of coagulation, fibrinolysis, contact and complement systems. Recent studies have suggested that cytokines and complement activation products may have overlapping biological activities. In addition, multiple interactions in vitro as well as in vivo between cytokines and complement have been described. Here we will review some of these recent studies and will discuss their relevance for the pathogenesis of sepsis and septic shock. 相似文献
10.
Steenbergen EJ; Verhagen OJ; van Leeuwen EF; van den Berg H; von dem Borne AE; van der Schoot CE 《Blood》1995,86(2):692-702
Crosslineage T-cell receptor delta (TCR delta) rearrangements are widely used as tumor markers for the follow up of minimal residual disease in childhood B-precursor acute lymphoblastic leukemia (ALL) by polymerase chain reaction (PCR). The major drawback of this approach is the risk of false-negative results due to clonal evolution. We investigated the stability of V delta 2D delta 3 rearrangements in a group of 56 childhood B-precursor ALL patients by PCR and Southern blot analysis. At the PCR level, V delta 2D delta 3-to-J alpha rearranged subclones (one pathway for secondary TCR delta recombination) were demonstrated in 85.2% of V delta 2D delta 3-positive patients tested, which showed that small subclones are present in the large majority of patients despite apparently monoclonal TCR delta Southern blot patterns. Sequence analysis of V delta 2D delta 3J alpha rearrangements showed a biased J alpha gene usage, with HAPO5 and J alpha F in 26 of 32 and 6 of 32 clones, respectively. Comparison of V delta 2D delta 3 rearrangement status between diagnosis and first relapse showed differences in seven of eight patients studied. In contrast, from first relapse onward, no clonal changes were observed in six patients studied. To investigate the occurrence of crosslineage TCR delta rearrangements in normal B and T cells, fluorescence-activated cell sorter-sorted peripheral blood CD19+/CD3- and CD19-/CD3+ cell populations from three healthy donors were analyzed. V delta 2D delta 3 rearrangements were detected at low frequencies in both B and T cells, which suggests that V delta 2-to-D delta 3 joining also occurs during normal B-cell differentiation. A model for crosslineage TCR delta rearrangements in B-precursor ALL is deduced that explains the observed clonal changes between diagnosis and relapse and is compatible with multistep leukemogenesis of B-precursor ALL. 相似文献