全文获取类型
收费全文 | 46959篇 |
免费 | 2883篇 |
国内免费 | 384篇 |
专业分类
耳鼻咽喉 | 626篇 |
儿科学 | 875篇 |
妇产科学 | 838篇 |
基础医学 | 5661篇 |
口腔科学 | 2115篇 |
临床医学 | 3809篇 |
内科学 | 12397篇 |
皮肤病学 | 591篇 |
神经病学 | 5014篇 |
特种医学 | 1832篇 |
外科学 | 7600篇 |
综合类 | 127篇 |
一般理论 | 8篇 |
预防医学 | 1840篇 |
眼科学 | 775篇 |
药学 | 2510篇 |
中国医学 | 89篇 |
肿瘤学 | 3519篇 |
出版年
2023年 | 479篇 |
2022年 | 438篇 |
2021年 | 1622篇 |
2020年 | 1090篇 |
2019年 | 1511篇 |
2018年 | 1741篇 |
2017年 | 1369篇 |
2016年 | 1517篇 |
2015年 | 1625篇 |
2014年 | 2117篇 |
2013年 | 2654篇 |
2012年 | 4036篇 |
2011年 | 4018篇 |
2010年 | 2202篇 |
2009年 | 2031篇 |
2008年 | 3100篇 |
2007年 | 3201篇 |
2006年 | 2855篇 |
2005年 | 2667篇 |
2004年 | 2431篇 |
2003年 | 2120篇 |
2002年 | 1873篇 |
2001年 | 327篇 |
2000年 | 271篇 |
1999年 | 270篇 |
1998年 | 285篇 |
1997年 | 257篇 |
1996年 | 193篇 |
1995年 | 199篇 |
1994年 | 190篇 |
1993年 | 153篇 |
1992年 | 142篇 |
1991年 | 118篇 |
1990年 | 112篇 |
1989年 | 84篇 |
1988年 | 100篇 |
1987年 | 74篇 |
1986年 | 64篇 |
1985年 | 70篇 |
1984年 | 71篇 |
1983年 | 61篇 |
1982年 | 67篇 |
1981年 | 40篇 |
1980年 | 39篇 |
1979年 | 48篇 |
1978年 | 36篇 |
1977年 | 24篇 |
1974年 | 24篇 |
1973年 | 34篇 |
1972年 | 28篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
1.
Ruscitti Piero Di Cola Ilenia Berardicurti Onorina Conforti Alessandro Iacono Daniela Pantano Ilenia Rozza Gelsomina Rossi Silvia De Stefano Ludovico Balduzzi Silvia Vitale Antonio Caso Francesco Costa Luisa Prete Marcella Navarini Luca Atzeni Fabiola Guggino Giuliana Perosa Federico Cantarini Luca Frediani Bruno Montecucco Carlomaurizio Ciccia Francesco Giacomelli Roberto Cipriani Paola 《Clinical rheumatology》2022,41(11):3597-3597
Clinical Rheumatology - 相似文献
2.
Marco N. Iannone Stefano Stucchi Elia A. Turolla Chiara Beretta Samuele Ciceri Clizia Chinello Lisa Pagani Sergio Todde Patrizia Ferraboschi 《Journal of labelled compounds & radiopharmaceuticals》2022,65(3):48-62
In the last decade, the development of new radiopharmaceuticals for the imaging and therapy of prostate cancer has been a highly active and important area of research, especially focusing on the prostate-specific membrane antigen (PSMA), an antigen which is upregulated in prostate, as well as in other tumor cells. A large variety of PSMA ligands have been radiolabeled, to date. Among the various derivatives, PSMA-617 resulted to be one of the most interesting in terms of interaction with the antigen and clinical properties, and its lutetium-177 labeled version has recently been approved by regulatory agencies for therapeutic purposes. For this reasons, the radiolabeling with fluorine-18 of a PSMA-617 derivative might be of interest. Beside other methodologies to radiolabel macromolecules with fluorine-18, the “click-chemistry” approach resulted to be very useful, and the copper-catalyzed azide-alkyne cycloaddition (CuAAC) is considered one of most efficient and reliable. This paper proposes the synthesis of a suitable precursor for the radiolabeling with fluorine-18 of a new PSMA-617 derivative. The whole radiosynthetic procedure has been fully automated, and the final product, which proved to be stable in plasma, has been obtained with radiochemical yield and purity suitable for subsequent preclinical studies. 相似文献
3.
4.
Klaus Schneider Marco Dilger Claudia Drossard Heidi Ott Eva Kaiser 《Journal of applied toxicology : JAT》2022,42(5):913-926
Frameworks for deriving occupational exposure limits (OELs) and OEL-analogue values (such as derived-no-effect levels [DNELs]) in various regulatory areas in the EU and at national level in Germany were analysed. Reasons for differences between frameworks and possible means of improving transparency and harmonisation were identified. Differences between assessment factors used for deriving exposure limits proved to be one important reason for diverging numerical values. Distributions for exposure time, interspecies and intraspecies extrapolation were combined by probabilistic methods and compared with default values of assessment factors used in the various OEL frameworks in order to investigate protection levels. In a subchronic inhalation study showing local effects in the respiratory tract, the probability that assessment factors were sufficiently high to protect 99% and 95% of the target population (workers) from adverse effects varied considerably from 9% to 71% and 17% to 87%, respectively, between the frameworks. All steps of the derivation process, including the uncertainty associated with the point of departure (POD), were further analysed with two examples of full probabilistic assessments. It is proposed that benchmark modelling should be the method of choice for deriving PODs and that all OEL frameworks should provide detailed guidance documents and clearly define their protection goals by stating the proportion of the exposed population the OEL aims to cover and the probability with which they intend to provide protection from adverse effects. Harmonisation can be achieved by agreeing on the way to perform the methodological steps for deriving OELs and on common protection goals. 相似文献
5.
6.
Paul G. Richardson Fredrik Schjesvold Katja Weisel Philippe Moreau Larry D. Anderson Darrell White Paula Rodriguez-Otero Pieter Sonneveld Monika Engelhardt Matthew Jenner Alessandro Corso Jan Dürig Michel Pavic Morten Salomo Meral Beksac Albert Oriol Jindriska Lindsay Anna Marina Liberati Monica Galli Pawel Robak Alessandra Larocca Munci Yagci Filiz Vural Abraham S. Kanate Ruiyun Jiang Lara Grote Teresa Peluso Meletios Dimopoulos 《European journal of haematology》2022,108(1):73-83
7.
8.
Theresa M. Thole Joern Toedling Annika Sprüssel Sebastian Pfeil Larissa Savelyeva David Capper Clemens Messerschmidt Dieter Beule Stefanie Groeneveld-Krentz Cornelia Eckert Guido Gambara Anton G. Henssen Sabine Finkler Johannes H. Schulte Anja Sieber Nils Bluethgen Christian R. A. Regenbrecht Annette Künkele Marco Lodrini Angelika Eggert Hedwig E. Deubzer 《International journal of cancer. Journal international du cancer》2020,146(4):1031-1041
Accurate modeling of intratumor heterogeneity presents a bottleneck against drug testing. Flexibility in a preclinical platform is also desirable to support assessment of different endpoints. We established the model system, OHC-NB1, from a bone marrow metastasis from a patient diagnosed with MYCN-amplified neuroblastoma and performed whole-exome sequencing on the source metastasis and the different models and passages during model development (monolayer cell line, 3D spheroid culture and subcutaneous xenograft tumors propagated in mice). OHC-NB1 harbors a MYCN amplification in double minutes, 1p deletion, 17q gain and diploid karyotype, which persisted in all models. A total of 80–540 single-nucleotide variants (SNVs) was detected in each sample, and comparisons between the source metastasis and models identified 34 of 80 somatic SNVs to be propagated in the models. Clonal reconstruction using the combined copy number and SNV data revealed marked clonal heterogeneity in the originating metastasis, with four clones being reflected in the model systems. The set of OHC-NB1 models represents 43% of somatic SNVs and 23% of the cellularity in the originating metastasis with varying clonal compositions, indicating that heterogeneity is partially preserved in our model system. 相似文献
9.
Susanna Zanutto Chiara Maura Ciniselli Antonino Belfiore Mara Lecchi Enzo Masci Gabriele Delconte Massimo Primignani Giulia Tosetti Marco Dal Fante Linda Fazzini Aldo Airoldi Marcello Vangeli Francesca Turpini Giovanni Giuseppe Rubis Passoni Paolo Viaggi Monica Arena Roberta Ilaria Olimpia Motta Anna Maria Cantù Cristiano Crosta Giuseppe De Roberto Francesca Iannuzzi Andrea Cassinotti Valentina Dall'Olio Laura Tizzoni Gabriella Sozzi Emanuele Meroni Luigi Bisanti Marco Alessandro Pierotti Paolo Verderio Manuela Gariboldi 《International journal of cancer. Journal international du cancer》2020,146(4):1164-1173
Colorectal cancer (CRC) screening programs help diagnose cancer precursors and early cancers and help reduce CRC mortality. However, currently recommended tests, the fecal immunochemical test (FIT) and colonoscopy, have low uptake. There is therefore a pressing need for screening strategies that are minimally invasive and consequently more acceptable to patients, most likely blood based, to increase early CRC identification. MicroRNAs (miRNAs) released from cancer cells are detectable in plasma in a remarkably stable form, making them ideal cancer biomarkers. Using plasma samples from FIT-positive (FIT+) subjects in an Italian CRC screening program, we aimed to identify plasma circulating miRNAs that detect early CRC. miRNAs were initially investigated by quantitative real-time PCR in plasma from 60 FIT+ subjects undergoing colonoscopy at Fondazione IRCCS Istituto Nazionale dei Tumori, then tested on an internal validation cohort (IVC, 201 cases) and finally in a large multicenter prospective series (external validation cohort [EVC], 1121 cases). For each endoscopic lesion (low-grade adenoma [LgA], high-grade adenoma [HgA], cancer lesion [CL]), specific signatures were identified in the IVC and confirmed on the EVC. A two-miRNA-based signature for CL and six-miRNA signatures for LgA and HgA were selected. In a multivariate analysis including sex and age at blood collection, the areas under the receiver operating characteristic curve (95% confidence interval) of the signatures were 0.644 (0.607–0.682), 0.670 (0.626–0.714) and 0.682 (0.580–0.785) for LgA, HgA and CL, respectively. A miRNA-based test could be introduced into the FIT+ workflow of CRC screening programs so as to schedule colonoscopies only for subjects likely to benefit most. 相似文献
10.
Despite the existence of endemic mycoses in Latin America and the Caribbean, in addition to a large population of patients at risk for invasive mycoses, the capability of medical centres to perform a proper diagnosis in mycology has not been studied in the region. Moreover, availability of antifungal drugs in the region is unknown. Here, we report the results of a survey involving 129 centres in 24 countries. Only 9% of centres would have the potential to apply for the minimum standards in mycology, as determined by the European Confederation of Medical Mycology. There is an urgent need to improve diagnostic conditions in Latin America and the Caribbean, as well as providing access to safer and more efficacious antifungal drugs. 相似文献