全文获取类型
收费全文 | 7232篇 |
免费 | 511篇 |
国内免费 | 125篇 |
专业分类
耳鼻咽喉 | 123篇 |
儿科学 | 194篇 |
妇产科学 | 186篇 |
基础医学 | 927篇 |
口腔科学 | 365篇 |
临床医学 | 613篇 |
内科学 | 1793篇 |
皮肤病学 | 170篇 |
神经病学 | 489篇 |
特种医学 | 341篇 |
外科学 | 851篇 |
综合类 | 54篇 |
一般理论 | 3篇 |
预防医学 | 607篇 |
眼科学 | 103篇 |
药学 | 583篇 |
中国医学 | 41篇 |
肿瘤学 | 425篇 |
出版年
2023年 | 42篇 |
2022年 | 105篇 |
2021年 | 224篇 |
2020年 | 135篇 |
2019年 | 216篇 |
2018年 | 271篇 |
2017年 | 170篇 |
2016年 | 212篇 |
2015年 | 247篇 |
2014年 | 303篇 |
2013年 | 351篇 |
2012年 | 506篇 |
2011年 | 506篇 |
2010年 | 280篇 |
2009年 | 261篇 |
2008年 | 386篇 |
2007年 | 439篇 |
2006年 | 315篇 |
2005年 | 305篇 |
2004年 | 267篇 |
2003年 | 256篇 |
2002年 | 221篇 |
2001年 | 199篇 |
2000年 | 179篇 |
1999年 | 182篇 |
1998年 | 83篇 |
1997年 | 87篇 |
1996年 | 51篇 |
1995年 | 46篇 |
1994年 | 37篇 |
1993年 | 34篇 |
1992年 | 84篇 |
1991年 | 86篇 |
1990年 | 86篇 |
1989年 | 53篇 |
1988年 | 45篇 |
1987年 | 62篇 |
1986年 | 46篇 |
1985年 | 61篇 |
1984年 | 42篇 |
1983年 | 34篇 |
1980年 | 20篇 |
1979年 | 38篇 |
1978年 | 20篇 |
1975年 | 24篇 |
1974年 | 27篇 |
1973年 | 26篇 |
1972年 | 19篇 |
1969年 | 23篇 |
1968年 | 19篇 |
排序方式: 共有7868条查询结果,搜索用时 62 毫秒
81.
Claudio Pinto María Raquel Ibez Gloria Loyola Luisa Len Yasmin Salvatore Carla Gonzlez Víctor Barraza Francisco Castaeda Rebeca Aldunate Loretto Contreras-Porcia Karen Fuenzalida Francisca C. Bronfman 《Nutrients》2021,13(6)
The biomedical potential of the edible red seaweed Agarophyton chilense (formerly Gracilaria chilensis) has not been explored. Red seaweeds are enriched in polyunsaturated fatty acids and eicosanoids, which are known natural ligands of the PPARγ nuclear receptor. PPARγ is the molecular target of thiazolidinediones (TZDs), drugs used as insulin sensitizers to treat type 2 diabetes mellitus. Medical use of TZDs is limited due to undesired side effects, a problem that has triggered the search for selective PPARγ modulators (SPPARMs) without the TZD side effects. We produced Agarophyton chilense oleoresin (Gracilex®), which induces PPARγ activation without inducing adipocyte differentiation, similar to SPPARMs. In a diet-induced obesity model of male mice, we showed that treatment with Gracilex® improves insulin sensitivity by normalizing altered glucose and insulin parameters. Gracilex® is enriched in palmitic acid, arachidonic acid, oleic acid, and lipophilic antioxidants such as tocopherols and β-carotene. Accordingly, Gracilex® possesses antioxidant activity in vitro and increased antioxidant capacity in vivo in Caenorhabditis elegans. These findings support the idea that Gracilex® represents a good source of natural PPARγ ligands and antioxidants with the potential to mitigate metabolic disorders. Thus, its nutraceutical value in humans warrants further investigation. 相似文献
82.
Aline S. Hora Sueli A. Taniwaki Nathana B. Martins Nataly N.R. Pinto Andr E. Schlemper Andr L.Q. Santos Matias P.J. Szab Paulo E. Brando 《Emerging infectious diseases》2021,27(4):1177
We obtained the complete sequence of a novel poxvirus, tentatively named Brazilian porcupinepox virus, from a wild porcupine (Coendou prehensilis) in Brazil that had skin and internal lesions characteristic of poxvirus infection. The impact of this lethal poxvirus on the survival of this species and its potential zoonotic importance remain to be investigated. 相似文献
83.
84.
Francesca Di Giallonardo Angie N Pinto Phillip Keen Ansari Shaik Alex Carrera Hanan Salem Christine Selvey Steven J Nigro Neil Fraser Karen Price Joanne Holden Frederick J Lee Dominic E Dwyer Benjamin R Bavinton Jemma L Geoghegan Andrew E Grulich Anthony D Kelleher the NSW HIV Prevention Partnership Project 《Journal of the International AIDS Society》2021,24(1)
IntroductionThe human immunodeficiency virus 1 (HIV‐1) pandemic is characterized by numerous distinct sub‐epidemics (clusters) that continually fuel local transmission. The aims of this study were to identify active growing clusters, to understand which factors most influence the transmission dynamics, how these vary between different subtypes and how this information might contribute to effective public health responses.MethodsWe used HIV‐1 genomic sequence data linked to demographic factors that accounted for approximately 70% of all new HIV‐1 notifications in New South Wales (NSW). We assessed differences in transmission cluster dynamics between subtype B and circulating recombinant form 01_AE (CRF01_AE). Separate phylogenetic trees were estimated using 2919 subtype B and 473 CRF01_AE sequences sampled between 2004 and 2018 in combination with global sequence data and NSW‐specific clades were classified as clusters, pairs or singletons. Significant differences in demographics between subtypes were assessed with Chi‐Square statistics.ResultsWe identified 104 subtype B and 11 CRF01_AE growing clusters containing a maximum of 29 and 11 sequences for subtype B and CRF01_AE respectively. We observed a > 2‐fold increase in the number of NSW‐specific CRF01_AE clades over time. Subtype B clusters were associated with individuals reporting men who have sex with men (MSM) as their transmission risk factor, being born in Australia, and being diagnosed during the early stage of infection (p < 0.01). CRF01_AE infections clusters were associated with infections among individuals diagnosed during the early stage of infection (p < 0.05) and CRF01_AE singletons were more likely to be from infections among individuals reporting heterosexual transmission (p < 0.05). We found six subtype B clusters with an above‐average growth rate (>1.5 sequences / 6‐months) and which consisted of a majority of infections among MSM. We also found four active growing CRF01_AE clusters containing only infections among MSM. Finally, we found 47 subtype B and seven CRF01_AE clusters that contained a large gap in time (>1 year) between infections and may be indicative of intermediate transmissions via undiagnosed individuals.ConclusionsThe large number of active and growing clusters among MSM are the driving force of the ongoing epidemic in NSW for subtype B and CRF01_AE. 相似文献
85.
Michel Ribeiro Fernandes Caroline Lorenzoni Almeida Ghezzi Tomaz JM Grezzana-Filho Fl via Heinz Feier Ian Leipnitz Aljamir Duarte Chedid Carlos Thadeu Schmidt Cerski Marcio Fernandes Chedid Cl ber Rosito Pinto Kruel 《World journal of gastrointestinal surgery》2021,13(3):315-322
BACKGROUNDPrimary extra-gastrointestinal stromal tumors (E-GIST) of the liver are rare. The clinical presentation may range from asymptomatic to bleeding or manifestations of mass effect. Oncologic surgery followed by adjuvant therapy with imatinib is the standard of care. However, under specific circumstances, a cytoreductive approach may represent a therapeutic option. We describe herein the case of an 84-year-old woman who presented with a tender, protruding epigastric mass. Abdominal computed tomography scan revealed a large, heterogeneous mass located across segments III, IV, V, and VIII of the liver. The initial approach was transarterial embolization of the tumor, which elicited no appreciable response. Considering the large size and central location of the tumor and the advanced age of the patient, non-anatomic complete resection was indicated. Due to substantial intraoperative bleeding and hemodynamic instability, only a near-complete resection could be achieved. Histopathology and immunohistochemical staining confirmed the diagnosis of primary E-GIST of the liver. Considering the risk/benefit ratio for therapeutic options, debulking surgery may represent a strategy to control pain and prolong survival.CASE SUMMARYHere, we present a case report of a patient diagnosed with E-GIST primary of the liver, which was indicated a cytoreductive surgery and adjuvant therapy with imatinib.CONCLUSIONE-GIST primary of the liver is a rare conditional, the treatment is with systemic therapy and total resection surgery. However, a cytoreductive surgery will be necessary when a complete resection is no possible. 相似文献
86.
87.
Canonical Wnt signals are essential for homeostasis of the intestinal epithelium 总被引:25,自引:0,他引:25 下载免费PDF全文
To assess the critical role of Wnt signals in intestinal crypts, we generated transgenic mice ectopically expressing Dickkopf1 (Dkk1), a secreted Wnt inhibitor. We find that epithelial proliferation is greatly reduced coincidentally with the loss of crypts. Although enterocyte differentiation appears unaffected, secretory cell lineages are largely absent. Disrupted intestinal homeostasis is reflected by an absence of nuclear beta-catenin, inhibition of c-myc expression, and subsequent up-regulation of p21CIP1/WAF1. Thus, our data are the first to establish a direct requirement for Wnt ligands in driving proliferation in the intestinal epithelium, and also define an unexpected role for Wnts in controlling secretory cell differentiation. 相似文献
88.
Economic evaluation of pharmaceuticals: a European perspective 总被引:1,自引:0,他引:1
Drummond M Rutten F Brenna A Pinto CG Horisberger B Jönsson B Le Pen C Rovira J von der Schulenburg MG Sintonen H 《PharmacoEconomics》1993,4(3):173-186
In recent years there has been a large increase in the number of economic evaluations of pharmaceuticals. Many of these studies have been commissioned by individual pharmaceutical companies, in support of new or existing products. In 2 countries, Australia and Canada (in the province of Ontario), draft guidelines issued by the government have outlined the requirements for economic evaluations to be submitted in support of requests for reimbursement (government subsidy) of particular products. One consequence of the guidelines is that they clarify what is required, and in specifying the procedure for submission of dossiers, identify a clear audience for the economic evaluation. In contrast, the situation in Europe is diverse. A wide range of healthcare systems exist, including national health services and more liberal systems, involving a wide range of insurers and providers. European countries also differ widely in their approach to the pricing and reimbursement of pharmaceuticals. Because of this diversity, the nature, conduct and impact of economic evaluation in Europe is not clear. It is therefore difficult for pharmaceutical companies to develop appropriate strategies for economic evaluation and for analysts to decide on appropriate study methodology. This article reviews the nature of any official guidance or requirements for economic evaluation, the potential for use of economic evaluation, the range of studies carried out and the identifiable impacts. There is currently no official guidance in any country, although some countries are considering issuing guidelines. In some countries there is official encouragement to pharmaceutical companies to undertake studies, and where economic data have been presented they have been considered by the relevant committees. The potential uses of economic evaluation vary widely from country to country. These can be classified in terms of a potential role in undertaking national price negotiations, deciding on reimbursement status or copayment level, deciding on inclusion in local formularies or in treatment guidelines, or in improving prescribing decisions. Approximately 80 economic evaluations of pharmaceutical products have been conducted to date in Europe, covering a wide range of clinical areas. There are relatively few examples of identifiable effects of such studies. In part this is because it is often difficult to assess the part played by various items of data. Nevertheless, the overriding conclusion is that economic evaluation of medicines is likely to be more relevant in Europe in the future. The problem for the pharmaceutical industry is in determining when and how. 相似文献
89.
Arullani A Cappello G De Pinto M Gabbianelli C 《Clinical nutrition (Edinburgh, Scotland)》1990,9(4):237-238
Anastomosis dehiscences after gastrectomy are a major post-operative complication often resulting in the death of the patient. 13 patients with dehiscences resulting in enterocutaneous fistulae have been treated with parenteral and/or enteral nutrition. Spontaneous closure rate was 84.6% and mean time for fistula closure was 22.4 days from the onset of nutritional treatment. On the base of nutritional effectiveness no difference could be found between enteral and parenteral nutrition in this series. 相似文献
90.
Competition in the health care market has intensified in recent years. Health care providers are increasingly adopting innovative marketing techniques to secure their positions in the marketplace. This paper examines an innovative marketing technique, situational segmentation, and assesses its applicability to the health care market. Situational segmentation has proven useful in many consumer goods markets but has received little attention in the context of health care marketing. A two-stage research process is used to develop a taxonomy of situational factors pertinent to health care choice. In stage one, focus group interviews are used to gather information which is instrumental to questionnaire development. In stage two, the responses of 151 subjects to a 51 item questionnaire are factor analyzed. The results demonstrate that situational segmentation is a viable strategy in the health care market. 相似文献