全文获取类型
收费全文 | 2581篇 |
免费 | 118篇 |
国内免费 | 22篇 |
专业分类
耳鼻咽喉 | 21篇 |
儿科学 | 85篇 |
妇产科学 | 34篇 |
基础医学 | 254篇 |
口腔科学 | 56篇 |
临床医学 | 219篇 |
内科学 | 471篇 |
皮肤病学 | 66篇 |
神经病学 | 144篇 |
特种医学 | 71篇 |
外科学 | 597篇 |
综合类 | 36篇 |
一般理论 | 1篇 |
预防医学 | 157篇 |
眼科学 | 71篇 |
药学 | 262篇 |
中国医学 | 14篇 |
肿瘤学 | 162篇 |
出版年
2024年 | 4篇 |
2023年 | 29篇 |
2022年 | 45篇 |
2021年 | 94篇 |
2020年 | 41篇 |
2019年 | 80篇 |
2018年 | 95篇 |
2017年 | 58篇 |
2016年 | 88篇 |
2015年 | 90篇 |
2014年 | 139篇 |
2013年 | 192篇 |
2012年 | 223篇 |
2011年 | 222篇 |
2010年 | 123篇 |
2009年 | 104篇 |
2008年 | 196篇 |
2007年 | 178篇 |
2006年 | 165篇 |
2005年 | 131篇 |
2004年 | 148篇 |
2003年 | 103篇 |
2002年 | 72篇 |
2001年 | 12篇 |
2000年 | 10篇 |
1999年 | 12篇 |
1998年 | 14篇 |
1997年 | 8篇 |
1996年 | 6篇 |
1995年 | 5篇 |
1994年 | 8篇 |
1993年 | 1篇 |
1991年 | 4篇 |
1990年 | 3篇 |
1989年 | 4篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1978年 | 1篇 |
1977年 | 2篇 |
1976年 | 1篇 |
排序方式: 共有2721条查询结果,搜索用时 15 毫秒
31.
Lal Pawanindra Anubhav Vindal Manoj Midha Prashant Nagpal Alpana Manchanda Jagdish Chander 《Surgical endoscopy》2015,29(10):2921-2927
32.
Kapil S. Agrawal Manoj V. Bachhav Charudatta S. Naik Shikha Gupta Anup V. Sarda Vyoma Desai 《Indian Journal of Plastic Surgery》2015,48(2):172-177
Augmentation rhinoplasty can be carried out using a wide range of materials including autologous bone and/or cartilage as well as alloplasts. Use of biologic bone and cartilage grafts results in lower infection rates, but they are associated with long-term resorption and donor-site morbidity. Alloplastic materials, in particular silicone, have been associated in literature with extrusion, necrosis of the tip, mobility and deviation or displacement of the implant, immobile nasal tip and infection. However, they have the advantages of being readily available and easy to reshape with no requirement for harvesting autografts.
Aim:
To overcome these problems associated with silicone implants for which the authors have devised a novel technique, the “rideon technique”.Materials and Methods:
The present study was carried out on 11 patients over a period of 4 years. The authors have devised a simple technique to fix the silicone implant and retain it in place. Restricting the implant to only dorsum avoided common complications related to the silicone implant.Results:
The authors have used this technique in 11 patients with encouraging results. Follow-up ranged from 12 months to 36 months during which patients were assessed for implant mobility, implant extrusion and tip necrosis. There was no incidence of above mentioned complications in these patients.Conclusion:
The “rideon technique” provides excellent stability to silicone implants and restricting the implant only to dorsum not only eliminates chances of tip necrosis and thus implant extrusion but also maintains natural shape, feel and mobility of the tip.KEY WORDS: Alloplasts, autografts, rhinoplasty, silicone implants 相似文献33.
34.
A series of magnetically separable rGO/Fe3O4 nanocomposites with various amounts of graphene oxide were successfully prepared by a simple ultrasonication assisted precipitation combined with a solvothermal method and their catalytic activity was evaluated for the selective liquid phase oxidation of cyclohexene using hydrogen peroxide as a green oxidant. The prepared materials were characterized using XRD, FTIR, FESEM, TEM, HRTEM, BET/BJH, XPS and VSM analysis. The presence of well crystallized Fe3O4 as the active iron species was seen in the crystal studies of the nanocomposites. The electron microscopy analysis indicated the fine surface dispersion of spherical Fe3O4 nanoparticles on the thin surface layers of partially-reduced graphene oxide (rGO) nanosheets. The decoration of Fe3O4 nanospheres on thin rGO layers was clearly observable in all of the nanocomposites. The XPS analysis was performed to evaluate the chemical states of the elements present in the samples. The surface area of the nanocomposites was increased significantly by increasing the amount of GO and the pore structures were effectively tuned by the amount of rGO in the nanocomposites. The magnetic saturation values of the nanocomposites were found to be sufficient for their efficient magnetic separation. The catalytic activity results show that the cyclohexene conversion reached 75.3% with a highest 1,2-cyclohexane diol selectivity of 81% over 5% rGO incorporated nanocomposite using H2O2 as the oxidant and acetonitrile as the solvent at 70 °C for 6 h. The reaction conditions were further optimized by changing the variables and a possible reaction mechanism was proposed. The enhanced catalytic activity of the nanocomposites for cyclohexene oxidation could be attributed to the fast accomplishment of the Fe2+/Fe3+ redox cycle in the composites due the sacrificial role of rGO and its synergistic effect with Fe3O4, originating from the conjugated network of π-electrons in its surface structure. The rapid and easy separation of the magnetic nanocomposites from the reaction mixture using an external magnet makes the present catalysts highly efficient for the reaction. Moreover, the catalyst retained its activity for five repeated runs without any drastic drop in the reactant conversion and product selectivity.A series of magnetically-separable and reusable rGO/Fe3O4 nanocomposites were successfully synthesized for the selective liquid-phase oxidation of cyclohexene to 1,2-cyclohexane-diol. 相似文献
35.
Merrick CJ Huttenhower C Buckee C Amambua-Ngwa A Gomez-Escobar N Walther M Conway DJ Duraisingh MT 《The Journal of infectious diseases》2012,205(10):1593-1600
Chronic infections with the human malaria parasite Plasmodium falciparum depend on antigenic variation. P. falciparum erythrocyte membrane protein 1 (PfEMP1), the major erythrocyte surface antigen mediating parasite sequestration in the microvasculature, is encoded in parasites by a highly diverse family of var genes. Antigenic switching is mediated by clonal variation in var expression, and recent in vitro studies have demonstrated a role for epigenetic processes in var regulation. Expression of particular PfEMP1 variants may result in parasite enrichment in different tissues, a factor in the development of severe disease. Here, we study in vivo human infections and provide evidence that infection-induced stress responses in the host can modify PfEMP1 expression via the perturbation of epigenetic mechanisms. Our work suggests that severe disease may not be the direct result of an adaptive virulence strategy to maximize parasite survival but that it may indicate a loss of control of the carefully regulated process of antigenic switching that maintains chronic infections. 相似文献
36.
Goodyear OC Dennis M Jilani NY Loke J Siddique S Ryan G Nunnick J Khanum R Raghavan M Cook M Snowden JA Griffiths M Russell N Yin J Crawley C Cook G Vyas P Moss P Malladi R Craddock CF 《Blood》2012,119(14):3361-3369
Strategies that augment a GVL effect without increasing the risk of GVHD are required to improve the outcome after allogeneic stem cell transplantation (SCT). Azacitidine (AZA) up-regulates the expression of tumor Ags on leukemic blasts in vitro and expands the numbers of immunomodulatory T regulatory cells (Tregs) in animal models. Reasoning that AZA might selectively augment a GVL effect, we studied the immunologic sequelae of AZA administration after allogeneic SCT. Twenty-seven patients who had undergone a reduced intensity allogeneic transplantation for acute myeloid leukemia were treated with monthly courses of AZA, and CD8(+) T-cell responses to candidate tumor Ags and circulating Tregs were measured. AZA after transplantation was well tolerated, and its administration was associated with a low incidence of GVHD. Administration of AZA increased the number of Tregs within the first 3 months after transplantation compared with a control population (P = .0127). AZA administration also induced a cytotoxic CD8(+) T-cell response to several tumor Ags, including melanoma-associated Ag 1, B melanoma antigen 1, and Wilm tumor Ag 1. These data support the further examination of AZA after transplantation as a mechanism of augmenting a GVL effect without a concomitant increase in GVHD. 相似文献
37.
38.
39.
Lalwani S Govindasamy M Gupta M Siraj F Varma V Mehta N Kumaran V Mohan N Chopra P Arora A Agarwal S Soin A Nundy S 《Indian journal of gastroenterology》2012,31(3):139-143
Mucormycosis of the gastrointestinal tract is a rare infection that usually occurs in patients who are immunocompromised and carries a high mortality. We report four cases of gastrointestinal mucormycosis seen over a one year period with different presentations, risk factors and different anatomical sites of involvement. A preoperative diagnosis was made only in one patient. All underwent surgery, three survived and one died postoperatively from multiorgan failure. 相似文献
40.
Joshua Burns Manoj Menezes Richard S. Finkel Tim Estilow Isabella Moroni Emanuela Pagliano Matilde Laurá Francesco Muntoni David N. Herrmann Kate Eichinger Rosemary Shy Davide Pareyson Mary M. Reilly Michael E. Shy 《Journal of the peripheral nervous system : JPNS》2013,18(2):177-180
Long‐term studies of Charcot‐Marie‐Tooth (CMT) disease across the entire lifespan require stable endpoints that measure the same underlying construct (e.g., disability). The aim of this study was to assess the relationship between the CMT Pediatric Scale (CMTPedS) and the adult CMT Neuropathy Score (CMTNSv2) in 203 children, adolescents, and young adults with CMT. There was a moderate curvilinear correlation between the CMTPedS and the CMTNSv2 (Spearman's rho ρ = 0.716, p < 0.0001), although there appears to be a floor effect of the CMTNSv2 in patients with a milder CMT phenotype. Univariate analyses indicate that the relationship between the CMTPedS and CMTNSv2 scores improves with worsening disease severity and advancing age. Although one universal scale throughout life would be ideal, our data supports the transition from the CMTPedS in childhood to the CMTNSv2 in adulthood as a continuum of measuring lifelong disability in patients with CMT. 相似文献