全文获取类型
收费全文 | 1414篇 |
免费 | 123篇 |
国内免费 | 3篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 41篇 |
妇产科学 | 22篇 |
基础医学 | 241篇 |
口腔科学 | 47篇 |
临床医学 | 118篇 |
内科学 | 345篇 |
皮肤病学 | 28篇 |
神经病学 | 86篇 |
特种医学 | 27篇 |
外科学 | 211篇 |
综合类 | 25篇 |
一般理论 | 1篇 |
预防医学 | 120篇 |
眼科学 | 39篇 |
药学 | 84篇 |
中国医学 | 7篇 |
肿瘤学 | 77篇 |
出版年
2023年 | 12篇 |
2022年 | 39篇 |
2021年 | 63篇 |
2020年 | 37篇 |
2019年 | 54篇 |
2018年 | 69篇 |
2017年 | 47篇 |
2016年 | 50篇 |
2015年 | 48篇 |
2014年 | 76篇 |
2013年 | 80篇 |
2012年 | 79篇 |
2011年 | 119篇 |
2010年 | 80篇 |
2009年 | 59篇 |
2008年 | 71篇 |
2007年 | 65篇 |
2006年 | 68篇 |
2005年 | 61篇 |
2004年 | 46篇 |
2003年 | 53篇 |
2002年 | 44篇 |
2001年 | 35篇 |
2000年 | 25篇 |
1999年 | 15篇 |
1998年 | 8篇 |
1997年 | 9篇 |
1996年 | 5篇 |
1995年 | 4篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 16篇 |
1991年 | 11篇 |
1990年 | 7篇 |
1989年 | 10篇 |
1988年 | 9篇 |
1987年 | 4篇 |
1986年 | 6篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 2篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1979年 | 7篇 |
1978年 | 3篇 |
1975年 | 2篇 |
1974年 | 2篇 |
1973年 | 2篇 |
1962年 | 1篇 |
1936年 | 1篇 |
排序方式: 共有1540条查询结果,搜索用时 31 毫秒
91.
92.
Coulibaly A. P. Gartman W. T. Swank V. Gomes J. A. Ruozhuo L. DeBacker J. Provencio J. J. 《Neurocritical care》2020,33(1):140-151
Neurocritical Care - How inflammatory cells are recruited into the central nervous system is a topic of interest in a number of neurological injuries. In aneurysmal subarachnoid hemorrhage (SAH),... 相似文献
93.
Development of remineralizing, antibacterial dental materials 总被引:2,自引:0,他引:2
Idris Mehdawi Ensanya A. Abou Neel Sabeel P. Valappil Graham Palmer Vehid Salih Jonathan Pratten Dave A. Spratt Anne M. Young 《Acta biomaterialia》2009,5(7):2525-2539
Light curable methacrylate dental monomers containing reactive calcium phosphate filler (monocalcium phosphate monohydrate (MCPM) with particle diameter of 29 or 90 μm) and β-tricalcium phosphate (β-TCP) at 1:1 weight ratio in a powder:liquid ratio (PLR) of 1:1 or 3:1 and chlorhexidine diacetate (0 or 5 wt.%), were investigated. Upon light exposure, approximately 90% monomer conversion was gained irrespective of the formulation. Increasing the PLR promoted water sorption by the set material, induced expansion and enhanced calcium, phosphate and chlorhexidine release. Concomitantly, a decline in compressive and biaxial flexural strengths occurred. With a reduction in MCPM particle diameter, however, calcium and phosphate release was reduced and less deterioration in strength observed. After 24 h, the remaining MCPM had reacted with water and β-TCP, forming, within the set materials, brushite of lower solubility. This provided a novel means to control water sorption, component release and strength properties. Measurable chlorhexidine release was observed for 6 weeks. Both diffusion rate and total percentage of chlorhexidine release decreased with lowering PLR or by adding buffer to the storage solutions. Higher chlorhexidine release was associated with reduced bacterial growth on agar plates and in a biofilm fermenter. In cell growth media, brushite and hydroxyapatite crystals precipitated on the composite material surfaces. Cells spread on both these crystals and the exposed polymer composite surfaces, indicating their cell compatibility. These formulations could be suitable antibacterial, biocompatible and remineralizing dental adhesives/liners. 相似文献
94.
Edgar Holznagel Barbara Yutzy Walter Schulz‐Schaeffer Kay‐Martin Hanschman Andreas Stuke Uwe Hahmann Mechthild Törner Cheick Coulibaly Andreas Hoffmann Gerhard Hunsmann Johannes Löwer 《Transfusion》2010,50(2):452-466
BACKGROUND: The cellular prion protein (PrPc) plays a central role in prion diseases such as variant Creutzfeldt‐Jakob disease. This disease can be transmitted by blood transfusion. However, the exact kinetics of blood infectivity and the blood fraction carrying infectivity have not yet been identified. STUDY DESIGN AND METHODS: Simian PrPc epitopes were mapped by flow cytometry using monoclonal antibodies (MoAbs). A whole blood/no wash protocol was established, validated, and applied to investigate peripheral blood cell–associated PrPc expression profiles in bovine spongiform encephalopathy (BSE)‐infected cynomolgus monkeys and age‐/sex‐matched controls. In addition, physiologic expression patterns on blood cells and in lymphoid tissues were determined. RESULTS: In BSE‐infected macaques, blood lymphocyte–associated PrPc fluorescence gradually increased years before the onset of clinical signs (pF test < 0.0001). The increase in fluorescence intensity was detectable with MoAb 12F10, whereas we failed to detect an increase with 3F4. In parallel, plasma concentrations of soluble CD230 also increased. Centrifugation of lymphocytes almost completely eliminated differences between infected and noninfected animals, most likely caused by a partial loss in cell‐associated CD230 into the plasma supernatant. CONCLUSION: Blood lymphocytes from asymptomatically infected as well as diseased macaques were characterized by increased CD230 fluorescence, and phosphatidylinositol‐phospholipase C–resistant PrP molecules contributed at least partially to this increase. Conformational changes within PrPc molecules may be the underlying mechanism for the increased PrPc fluorescence. This cell‐associated phenomenon contributed at least partially to an increase in soluble plasma‐derived PrPc levels. It is not yet known whether these changes reflect infectivity. 相似文献
95.
An undescribed virus with isometric particles and a diameter of ca. 30 nm was identified in diseased samples of wild and cultivated Rubus species and molecularly characterized. Its genome was 6,463 nt, excluding the 3′-terminal poly(A) tail, and contained a single
open reading frame coding for a 2,035-amino-acid-long precursor polypeptide (p223). The amino terminal portion of p223, identified
as a replication-associated polyprotein, contained conserved motifs of methyltransferase, endopeptidase/protease, helicase
and RNA-dependent RNA polymerase. The carboxy terminus of the large polypeptide is involved in the formation of two viral
coat protein subunits with deduced molecular masses of 23 and 21 kDa. Pairwise comparisons and phylogenetic analyses showed
closest relationships of this virus with oat blue dwarf virus and citrus sudden death-associated virus, sharing levels of
genome sequence conservation far below the species demarcation level established for tymovirids. Our data indicate that this
virus, for which the name blackberry virus S (BlVS) is proposed, is a hitherto undescribed species of the genus Marafivirus, family Tymoviridae. A survey conducted in Mississippi, USA, has shown that BlVS is also present in cultivated Rubus germplasm. This work represents the first report of a marafivirus infecting small fruits. 相似文献
96.
L. Bezza A. Mannarino K. Fattarsi C. Mikail L. Abou F. Hadji-Minaglou J. Kaloustian 《Phytothérapie》2010,8(5):277-281
Artemisia herba-alba Asso (Asteraceae) essential oil (EO), obtained by hydrodistillation from aerial parts, and was investigated using GC-FID and GC-MS techniques. The EO yield, based on dry weight, was 0.95% (v/w). Forty six components corresponding to 92.61% of the oil were identified. The EO contained in majority: cis-chrysanthenyl acetate (25.12%); (2E,3Z) 3,5-heptadienal-2-ethyliden-6-methyl (8.39%); α-thujone (7.85%); myrtenyl acetate (7.39%); verbenone (7.19%), chrysanthenone (4.98%). Chemical composition was very specific for this Algerian plant. 相似文献
97.
98.
Azza Abou El Enein Reham A. Aleem Afify Doaa M. Soliman Nehal Dyaa 《Comparative clinical pathology》2014,23(1):111-118
The importance of chimerism is that it is useful to demonstrate engraftment. It allows for early intervention which might facilitate treatment of emerging relapse in leukemia, and it may help to prevent graft rejection. The aim of this study is to evaluate mixed red cell population and red blood cell chimerism after hematopoietic stem cell transplantation to predict the final outcome of mixed chimerism which may help in deciding interventions and preventing graft rejection. This study was conducted on 22 bone marrow-transplanted patients admitted to Bone Marrow Transplantation (BMT) Unit, Nasser institute, using simple agglutination method and flow cytometery (FCM) technique. In our study, three recipients had complete chimerism after 6 month which was detected by agglutination method, and one recipient had complete chimerism after 1 year which was detected by both simple agglutination method and FCM. Two recipients had mixed-field agglutination after 30 days which was detected by agglutination method and FCM. Evaluating erythrocyte repopulation by the agglutination method is feasible, easy, and cost-effective. FCM analysis is a simple, sensitive test and an objective method, which could be used as a protocol for follow-up to detect chimerism after allogeneic BMT. However, due to the difficulty found in retrieving the patients for follow-up, we suggest the use of alternative methods for detection of chimerism as variable number of tandem repeats and XY fluorescence in situ hybridization probe. 相似文献
99.
Ahmed Abou‐Elseoud Tuomo Starck Jukka Remes Juha Nikkinen Osmo Tervonen Vesa Kiviniemi 《Human brain mapping》2010,31(8):1207-1216
Independent component analysis (ICA) of functional MRI data is sensitive to model order selection. There is a lack of knowledge about the effect of increasing model order on independent components' (ICs) characteristics of resting state networks (RSNs). Probabilistic group ICA (group PICA) of 55 healthy control subjects resting state data was repeated 100 times using ICASSO repeatability software and after clustering of components, centrotype components were used for further analysis. Visual signal sources (VSS), default mode network (DMN), primary somatosensory (S1), secondary somatosensory (S2), primary motor cortex (M1), striatum, and precuneus (preC) components were chosen as components of interest to be evaluated by varying group probabilistic independent component analysis (PICA) model order between 10 and 200. At model order 10, DMN and VSS components fuse several functionally separate sources that at higher model orders branch into multiple components. Both volume and mean z‐score of components of interest showed significant (P < 0.05) changes as a function of model order. In conclusion, model order has a significant effect on ICs characteristics. Our findings suggest that using model orders ≤20 provides a general picture of large scale brain networks. However, detection of some components (i.e., S1, S2, and striatum) requires higher model order estimation. Model orders 30–40 showed spatial overlapping of some IC sources. Model orders 70 ± 10 offer a more detailed evaluation of RSNs in a group PICA setting. Model orders > 100 showed a decrease in ICA repeatability, but added no significance to either volume or mean z‐score results. Hum Brain Mapp, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
100.
La Ruche G Ladner J Lattier R Djéha D Louise D Coulibaly IM 《Health policy and planning》2000,15(4):441-446
In C?te d'Ivoire, management of sexually transmitted diseases (STDs) is based on a syndromic approach. The National Health Information System (NHIS), set up in 1995, supervises data drawn monthly on three STD syndromes: genital ulcers, discharges and warts. Information is collected in each community-based public clinic, collated in the 29 districts, then in the 10 regions, and finally centralized. We assessed the relevance of this information and its usefulness for the STD programme. The number of cases notified in adults of 15 years and above was compared in men and women for the years 1995 and 1996. The absolute number of cases was related to the number of consultations to evaluate the relative share of STDs in health care services, and to the population size to estimate STD annual incidence. Between 1995 and 1996, the number of reported STD cases remained steady in men, 32 410 and 31 470 cases, respectively, but increased by 35% in women, from 64 794 to 87 622 cases. As a result, STD annual incidence was unchanging in men (8%), but increased in women from 17 to 23%. However, between these two years, the relative contribution of STDs to all consultations decreased from 4.7 to 3.5% in men, while remaining steady in women, at around 7.0%. In this 2-year period, the ratio of the numbers of ulcers in men and women was about 1:1, and did not vary by district. In contrast, discharges were reported 2.7 times more by women, with a differing sex ratio from district to district. We suggest that vaginal discharges are often physiological, and are poorly instructive for STD surveillance. In contrast, ulcers in both genders, and male discharges, provide relevant information for the STD programme, for example to estimate the volume of STD drugs needed for public health services and to assess the epidemiological trends of STDs. 相似文献