全文获取类型
收费全文 | 15959篇 |
免费 | 1267篇 |
国内免费 | 368篇 |
专业分类
耳鼻咽喉 | 106篇 |
儿科学 | 547篇 |
妇产科学 | 268篇 |
基础医学 | 4205篇 |
口腔科学 | 211篇 |
临床医学 | 927篇 |
内科学 | 2377篇 |
皮肤病学 | 298篇 |
神经病学 | 996篇 |
特种医学 | 456篇 |
外国民族医学 | 2篇 |
外科学 | 1879篇 |
综合类 | 1104篇 |
现状与发展 | 2篇 |
预防医学 | 665篇 |
眼科学 | 154篇 |
药学 | 1781篇 |
1篇 | |
中国医学 | 329篇 |
肿瘤学 | 1286篇 |
出版年
2023年 | 236篇 |
2022年 | 407篇 |
2021年 | 515篇 |
2020年 | 463篇 |
2019年 | 623篇 |
2018年 | 546篇 |
2017年 | 505篇 |
2016年 | 469篇 |
2015年 | 558篇 |
2014年 | 881篇 |
2013年 | 915篇 |
2012年 | 684篇 |
2011年 | 872篇 |
2010年 | 767篇 |
2009年 | 773篇 |
2008年 | 694篇 |
2007年 | 701篇 |
2006年 | 711篇 |
2005年 | 625篇 |
2004年 | 584篇 |
2003年 | 517篇 |
2002年 | 384篇 |
2001年 | 334篇 |
2000年 | 258篇 |
1999年 | 272篇 |
1998年 | 256篇 |
1997年 | 240篇 |
1996年 | 239篇 |
1995年 | 201篇 |
1994年 | 164篇 |
1993年 | 166篇 |
1992年 | 141篇 |
1991年 | 132篇 |
1990年 | 98篇 |
1989年 | 87篇 |
1988年 | 108篇 |
1987年 | 98篇 |
1986年 | 97篇 |
1985年 | 190篇 |
1984年 | 189篇 |
1983年 | 127篇 |
1982年 | 133篇 |
1981年 | 113篇 |
1980年 | 101篇 |
1979年 | 91篇 |
1978年 | 63篇 |
1977年 | 52篇 |
1976年 | 55篇 |
1975年 | 42篇 |
1973年 | 39篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Xiao-Long Tang Yan-Dong Miao Deng-Hai Mi 《World journal of gastrointestinal oncology》2022,14(1):366-368
The present letter to the editor is in response to the research “Outcomes of curative liver resection for hepatocellular carcinoma in patients with cirrhosis” by Elshaarawy et al in World J Gastroenterol 2021; 13(5): 424–439. The preoperative assessment of the liver reserve function in hepatocellular carcinoma (HCC) patients with cirrhosis is crucial, and there is no universal consensus on how to assess it. Based on a retrospective study, Elshaarawy et al investigated the impact of various classical clinical indicators on liver failure and the prognosis after hepatectomy in HCC patients with cirrhosis. We recommend that we should strive to explore new appraisal indicators, such as the indocyanine green retention rate at 15 min. 相似文献
2.
Major depressive disorder and other neuropsychiatric disorders are often managed with long-term use of antidepressant medication. Fluoxetine, an SSRI antidepressant, is widely used as a first-line treatment for neuropsychiatric disorders. However, fluoxetine has also been shown to increase the risk of metabolic diseases such as non-alcoholic fatty liver disease. Fluoxetine has been shown to increase hepatic lipid accumulation in vivo and in vitro. In addition, fluoxetine has been shown to alter the production of prostaglandins which have also been implicated in the development of non-alcoholic fatty liver disease. The goal of this study was to assess the effect of fluoxetine exposure on the prostaglandin biosynthetic pathway and lipid accumulation in a hepatic cell line (H4-II-E-C3 cells). Fluoxetine treatment increased mRNA expression of prostaglandin biosynthetic enzymes (Ptgs1, Ptgs2, and Ptgds), PPAR gamma (Pparg), and PPAR gamma downstream targets involved in fatty acid uptake (Cd36, Fatp2, and Fatp5) as well as production of 15-deoxy-Δ12,14PGJ2 a PPAR gamma ligand. The effects of fluoxetine to induce lipid accumulation were attenuated with a PTGS1 specific inhibitor (SC-560), whereas inhibition of PTGS2 had no effect. Moreover, SC-560 attenuated 15-deoxy-Δ12,14PGJ2 production and expression of PPAR gamma downstream target genes. Taken together these results suggest that fluoxetine-induced lipid abnormalities appear to be mediated via PTGS1 and its downstream product 15d-PGJ2 and suggest a novel therapeutic target to prevent some of the adverse effects of fluoxetine treatment. 相似文献
3.
4.
目的:观察理气中药经验组方对糖尿病大鼠胃排空延迟的干预作用。方法:雌雄各半成年SD大鼠110只,随机分为正常组(A组)、糖尿病中药组(B组)、糖尿病胃复安组(C组)、糖尿病组(D组)。A组、D组1次/d按10 mL/只予0.9%生理盐水灌胃,B组1次/d按8 mL/只予中药煎剂灌胃,C组1次/d按0.5 mg/只予胃复安片灌胃。喂养12周后,行13C胃排空实验及甲基橙水溶液胃排空实验,观察各组大鼠胃排空情况。结果:糖尿病大鼠胃排空较正常大鼠明显延迟(P0.01),糖尿病大鼠胃排空延迟模型制作成功。糖尿病中药组和糖尿病胃复安组大鼠胃排空较糖尿病组快(P0.01);糖尿病中药组大鼠胃排空较糖尿病胃复安组大鼠快(P0.05)。结论:常规喂养12周后糖尿病大鼠出现胃排空延迟。理气中药陈皮、枳实、木香、香附组方煎剂和胃复安均能促进糖尿病大鼠胃排空,理气中药组方煎剂的效果优于胃复安。 相似文献
5.
DNA mixture interpretation can produce opposing conclusions by qualified forensic analysts, even within the same laboratory. The long-delayed publication of the National Institutes of Standards and Technology (NIST) study of 109 North American crime laboratories in this journal demonstrates this most clearly. This latest study supports earlier work that shows common methods such as the Combined Probability of Inclusion (CPI) have wrongly included innocent people as contributors to DNA mixtures. The 2016 President's Council of Advisors on Science and Technology report concluded, “In summary, the interpretation of complex DNA mixtures with the CPI statistic has been an inadequately specified—and thus inappropriately subjective—method. As such, the method is clearly not foundationally valid” [7]. The adoption of probabilistic genotyping by many laboratories will certainly prevent some of these errors from occurring in the future, but the same laboratories that produced past errors can also now review old cases with their new software—without additional bench work. It is critical that laboratories adopt procedures and policies to do this. 相似文献
6.
6-Mercaptopurine (6-MP) is commonly used for treatment of acute lymphoblastic leukemia (ALL). The incidence of hematotoxicity caused by this drug is quite high in Asians even using a standard low dosage regimen. The present study was aimed to elucidate the impact of thiopurine S-methyltransferase (TPMT), a nucleoside diphosphate-linked moiety X-type motif 15 (NUDT15), inosine triphosphatase (ITPA) and ATP Binding Cassette Subfamily C Member 4 (ABCC4) polymorphisms on hematotoxicity in pediatric patients who received a standard low starting dose of 6-MP. One hundred and sixty-nine pediatric patients were enrolled and their genotypes were determined. Patients who carried NUDT1513 and NUDT1512 genotypes were at a 10–15 fold higher risk of severe neutropenia than those of the wild-type during the early months of the maintenance phase. Risk of neutropenia was not significantly increased in patients with other NUDT15 variants as well as in patients with TPMT, ITPA or ABCC4 variants. These results suggest that NUDT15 polymorphisms particularly, NUDT1513 and NUDT1512, play major roles in 6-MP-induced severe hematotoxicity even when using a standard low dosage of 6-MP and genotyping of these variants is necessary in order to obtain precise tolerance doses and avoid severe hematotoxicity in pediatric patients. 相似文献
7.
Fabrice Barlesi Edward B. Garon Dong-Wan Kim Enriqueta Felip Ji-Youn Han Joo-Hang Kim Myung-Ju Ahn Mary Jo Fidler Matthew A. Gubens Gilberto de Castro Veerle Surmont Qiao Li Anne C. Deitz Gregory M. Lubiniecki Roy S. Herbst 《Journal of thoracic oncology》2019,14(5):793-801
Introduction
In the phase II/III KEYNOTE-010 study (ClinicalTrials.gov, NCT01905657), pembrolizumab significantly prolonged overall survival over docetaxel in patients with previously treated, programmed death ligand 1–expressing (tumor proportion score ≥ 1%), advanced NSCLC. Health-related quality of life (HRQoL) results are reported here.Methods
Patients were randomized 1:1:1 to pembrolizumab 2 or 10 mg/kg every 3 weeks or docetaxel 75 mg/m2 every 3 weeks. HRQoL was assessed using European Organisation for Research and Treatment of Cancer (EORTC) Quality of Life Questionnaire (QLC) Core 30 (C30), EORTC QLQ–Lung Cancer 13 (LC13), and EuroQoL-5D. Key analyses included mean baseline-to-week-12 change in global health status (GHS)/quality of life (QoL) score, functioning and symptom domains, and time to deterioration in a QLQ-LC13 composite endpoint of cough, dyspnea, and chest pain.Results
Patient reported outcomes compliance was high across all three instruments. Pembrolizumab was associated with better QLQ-C30 GHS/QoL scores from baseline to 12 weeks than docetaxel, regardless of pembrolizumab dose or tumor proportion score status (not significant). Compared with docetaxel, fewer pembrolizumab-treated patients had “deteriorated” status and more had “improved” status in GHS/QoL. Nominally significant improvement was reported in many EORTC symptom domains with pembrolizumab, and nominally significant worsening was reported with docetaxel. Significant prolongation in true time to deterioration for the QLQ-LC13 composite endpoint emerged for pembrolizumab 10 mg/kg compared to docetaxel (nominal two-sided p = 0.03), but not for the 2-mg/kg dose.Conclusions
These findings suggest that HRQoL and symptoms are maintained or improved to a greater degree with pembrolizumab than with docetaxel in this NSCLC patient population. 相似文献8.
Keith P. Reber John D. Sivey Matthew Vollmuth Priyansh D. Gujarati 《Journal of labelled compounds & radiopharmaceuticals》2022,65(9):254-263
Parabens are antimicrobial additives found in a wide array of consumer products. However, the halogenated compounds formed from parabens during wastewater disinfection are a potential environmental concern. In order to identify these transformation products and investigate their mechanism of formation, a synthetic route to ethyl parabens labeled with the stable isotope carbon-13 at specific positions within the benzene ring was developed. This efficient two-step procedure starts from commercially available 13C-labeled phenols and involves (1) initial acylation of the phenol via a Houben–Hoesch reaction with trichloroacetonitrile followed by (2) a modified haloform reaction of the resulting trichloromethyl ketone to afford the corresponding 13C-labeled ethyl parabens in 65%–80% overall yield. The scope of the modified haloform reaction was also investigated, allowing for the synthesis of other parabens derived from primary or secondary alcohols, including 13C- and deuterium-labeled esters. In addition, 4-hydroxybenzoic acid can be formed directly from the common trichloromethyl ketone intermediate upon treatment with lithium hydroxide. This protocol complements existing methods for preparing 13C-labeled paraben derivatives and offers the specific advantages of exhibiting complete regioselectivity in the Houben–Hoesch reaction (to form the para-disubstituted product) and avoiding the need for protecting groups in the modified haloform reaction that forms the paraben esters. 相似文献
9.
《Clinical Lymphoma, Myeloma & Leukemia》2020,20(8):e461-e467
IntroductionVon Willebrand factor (vWF) cleaving protease ADAMTS-13 has a key role for maintaining normal size of vWF. A deficiency or dysfunction of vWF cleaving protease is associated with ultra large vWF multimers and thrombotic microangiopathy. Patients with cancers have reduced levels of vWF cleaving protease. In this pilot study, we have evaluated whether or not deficiencies of ADAMTS-13 were present in myelodysplastic syndromes (MDS). Moreover, we assessed if a reduction in basal levels of ADAMTS-13 may play a role in the prognosis of MDS.Patients and MethodsWe measured and compared the levels of vWF cleaving protease ADAMTS-13 in 100 patients with MDS and 35 healthy controls. Patients were divided into 2 groups according to the International Prognostic Scoring System: group I consisting of 44 patients with low-risk MDS and group II of 56 patients with high-risk MDS. Patients with high-risk and low-risk MDS presented significantly lower levels of ADAMTS-13 than controls (P < .001 and P = .0177, respectively). High-risk patients had significantly lower levels of ADAMTS-13 when compared with the low-risk group (P < .001).ResultsWe found that reduced levels of ADAMTS-13 have a relationship with overall survival (P < .001). Statistical analysis showed that ADAMTS-13 correlates with cytogenetics (P < .001) and a tendency of slight correlation with platelet count and basal levels of ADAMTS-13 (R, 0.35; P value, 0.001). Moreover, we found that levels of ADAMTS-13 have correlation with response to treatment (P < .001).ConclusionsADAMTS-13 in MDS might represent a surrogate marker of prognosis, response to therapy, or disease progression. Further studies are needed. 相似文献
10.