全文获取类型
收费全文 | 47248篇 |
免费 | 2821篇 |
国内免费 | 119篇 |
专业分类
耳鼻咽喉 | 686篇 |
儿科学 | 2103篇 |
妇产科学 | 1075篇 |
基础医学 | 5897篇 |
口腔科学 | 1947篇 |
临床医学 | 4512篇 |
内科学 | 9670篇 |
皮肤病学 | 1165篇 |
神经病学 | 3917篇 |
特种医学 | 1471篇 |
外国民族医学 | 2篇 |
外科学 | 7203篇 |
综合类 | 171篇 |
一般理论 | 17篇 |
预防医学 | 3119篇 |
眼科学 | 1333篇 |
药学 | 3098篇 |
中国医学 | 185篇 |
肿瘤学 | 2617篇 |
出版年
2023年 | 356篇 |
2022年 | 333篇 |
2021年 | 843篇 |
2020年 | 569篇 |
2019年 | 893篇 |
2018年 | 1399篇 |
2017年 | 1004篇 |
2016年 | 1124篇 |
2015年 | 1130篇 |
2014年 | 1412篇 |
2013年 | 2120篇 |
2012年 | 3309篇 |
2011年 | 3730篇 |
2010年 | 1937篇 |
2009年 | 1419篇 |
2008年 | 3145篇 |
2007年 | 3382篇 |
2006年 | 3292篇 |
2005年 | 3327篇 |
2004年 | 3202篇 |
2003年 | 2946篇 |
2002年 | 2825篇 |
2001年 | 951篇 |
2000年 | 1038篇 |
1999年 | 690篇 |
1998年 | 398篇 |
1997年 | 327篇 |
1996年 | 263篇 |
1995年 | 235篇 |
1994年 | 205篇 |
1993年 | 186篇 |
1992年 | 173篇 |
1991年 | 160篇 |
1990年 | 144篇 |
1989年 | 137篇 |
1988年 | 115篇 |
1987年 | 104篇 |
1986年 | 122篇 |
1985年 | 81篇 |
1984年 | 104篇 |
1983年 | 88篇 |
1982年 | 79篇 |
1981年 | 56篇 |
1980年 | 68篇 |
1979年 | 88篇 |
1978年 | 63篇 |
1977年 | 59篇 |
1976年 | 50篇 |
1974年 | 51篇 |
1973年 | 53篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Rodrigo Holanda Mendonça Ligia Maria Sotero Machado Carlos Otto Heise Graziela Jorge Polido Ciro Matsui André Macedo Serafim Silva Umbertina Conti Reed Edmar Zanoteli 《Neuromuscular disorders : NMD》2021,31(6):498-504
Spinal muscular atrophy (SMA) is a motor neuron disease associated with progressive muscle weakness and motor disability. The motor unit number index (MUNIX) is a biomarker used to assess loss of motor units in later-onset SMA patients. Twenty SMA patients (SMA types 3 and 4), aged between 7 and 41 years, were clinically evaluated through the Hammersmith Motor Functional Scale Expanded and the Spinal Muscular Atrophy-Functional Rating Scale. The patients underwent compound motor action potential (CMAP) and MUNIX studies of the right abductor pollicis brevis, abductor digiti minimi and tibialis anterior (TA) muscles. Age-matched healthy controls (n = 20) were enrolled to obtain normative CMAP and MUNIX values from the same muscles. Compared to healthy controls, SMA patients showed significant reductions in MUNIX values among all muscles studied, whereas CMAP showed reductions only in the weaker muscles (abductor digiti minimi and TA). MUNIX variability was significantly higher in the SMA group than in the control group. MUNIX variability in TA correlated with CMAP variability. Motor functional scores correlated with TA MUNIX. The MUNIX study is feasible in later-onset SMA patients, and TA MUNIX values correlate with disease severity in patients with mild motor impairment. 相似文献
992.
İlker Durak Recep Çetin Özden Çandır Erdinç Devrim Bülent Kılıçoğlu Aslıhan Avcı 《Immunological investigations》2013,42(1):105-114
The aim of this study was to determine if the natural antioxidant foods, dried black grape and garlic, protect against cyclosporine nephrotoxicity. Forty-two Sprague–Dawley rats were given Cyclosporine A (CsA) orally for 10 days, with the antioxidant food supplementation begun 3 days before CsA treatment and continued during the study period (totaling 13 days). In each group (control, CsA alone, CsA plus black grape, CsA plus aqueous garlic extract, aqueous garlic extract alone and black grape alone), there were 7 animals. At the end of the study period, the animals were sacrificed; their kidneys were removed and prepared for biochemical and histopathological investigations. Oxidant (xanthine oxidase enzyme and malondialdehyde) and antioxidant (superoxide dismutase, glutathione peroxidase and catalase enzymes) parameters were measured in the kidney tissues of the groups. Histopathological examinations of the tissues were also performed.It has been found that CsA creates oxidant load to the kidneys through both xanthine oxidase activation and impaired antioxidant defense system, which accelerates oxidation reactions in the kidney tissue. Supplementation with either dried black grape or aqueous garlic extract led to reduced malondialdehyde level in the kidney tissue possibly, by preventing oxidant reactions. In conclusion, the results suggest that impaired oxidant/antioxidant balance may play part in the CsA-induced nephrotoxicity, and some foods with high antioxidant power may ameliorate this toxicity, in agreement with studies with antioxidant vitamins. 相似文献
993.
Phylogeography of rabies virus isolated from herbivores and bats in the Espírito Santo State, Brazil
Luiz Fernando Pereira Vieira Sílvia Regina Ferreira Gonçalves Pereira Pedro Carnieli Jr. Luiz Carlos Barbosa Tavares Ivanete Kotait 《Virus genes》2013,46(2):330-336
Rabies is enzootic in the State of Espírito Santo, Brazil. Every year, cattle and horses die from rabies that is transmitted by the vampire bat Desmodus rotundus. This paper describes the spread of the rabies virus by the continuous diffusion model using relaxed random walks with BEAST software. Forty-one (41) sequences of gene G from the rabies virus that was isolated from bats and domestic herbivores from several areas of the state between 2006 and 2010 were analyzed. The phylogenetic tree showed three main clusters as well as two sub-clusters under cluster 2. A spatial analysis showed that three strains of the rabies virus spread independently. In general, central Espírito Santo, which is mountainous, was the area where separation of the virus strains occurred. This physical barrier, however, was overcome at some point in time, as samples from different lineages were found in the same microarea. 相似文献
994.
Alexandre Simões Nogueira Eduardo Sanches Gonçales Paulo Sergio da Silva Santos José Humberto Damante Phillipe Nogueira Barbosa Alencar Fernanda Araújo Sampaio Alexandre Simões Garcia 《Surgical and radiologic anatomy : SRA》2013,35(9):867-871
Despite the nomenclature suggested to be a tumor, torus palatinus (TP) is an overgrowth of the bone in the palatal region and represents an anatomic variation. Its prevalence varies among the population studied and its etiology is still unclear; however, it seems to be a multifactorial disorder with genetics and environmental involvement. Surgical removal of the TP is indicated in the following circumstances: (1) deglutition and speech impairment, (2) cancer phobia, (3) traumatized mucosa over the torus, and (4) prosthetic reasons. The aim of this case report is describe cases that occurred in two sisters, emphasizing the genetic etiology of this anatomic variation. In addition, intra-oral exam and computed tomography scan (axial, coronal and sagittal view) provided a detailed assessment of the TP and elimination of other possible diagnoses, furthermore allowed a better analyzes of the anatomic relation with adjacentes structures. No surgical removal was indicated for both cases. 相似文献
995.
Chiang Jannifer O. Azevedo Rafael S. Justino Maria C. A. Matos Haroldo J. Cabeça Hideraldo L. S. Silva Sandro P. Henriques Daniele F. Silva Eliana V. P. Andrade Gabriela S. S. Vasconcelos Pedro FC. Martins Lívia C. Azevedo Raimunda S. S. 《Journal of neurovirology》2021,27(4):626-630
Journal of NeuroVirology - We describe two neurological cases of Oropouche virus infection in northern Brazil, where the virus is endemic but neglected as a pathogen. This study reiterates the... 相似文献
996.
Rodney A. Bray Elisabeth Faliex Jean François Allienne Gabriel Mouahid 《Parasitology research》2013,112(12):3981-3989
Lepidapedon sereti n. sp. is described from the macrourid Coelorinchus sereti from the deep water off Vanuatu. It is placed in the Elongatum group and Elongatum subgroup. It differs from the other species described in this subgroup by the distinctly dorsally subterminal excretory pore. It also differs from other species in combinations of size, excretory vesicle length, proportions of forebody, post-testicular region and other metric features. This constitutes the first record of a Lepidapedon (sensu stricto) from the Central Western Pacific Ocean. 相似文献
997.
J. Brauner M. Hallin A. Deplano R. De Mendonça C. Nonhoff R. De Ryck S. Roisin M. J. Struelens O. Denis 《European journal of clinical microbiology & infectious diseases》2013,32(5):613-620
The present study reports the evolution of the demographic characteristics and the molecular epidemiology of community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) in Belgium from 2005 to 2009. Four hundred and ten CA-MRSA isolates were prospectively collected and screened for the presence of Panton–Valentin leucocidin (PVL) and toxic shock syndrome toxin 1 (TSST-1) encoding genes, while clinical information were recorded. PVL- and TSST-1-positive isolates were genotyped by pulsed-field gel electrophoresis (PFGE). Staphylococcal cassette chromosome mec (SCCmec) type, spa type and multilocus sequence type (MLST) were determined on representative isolates. One hundred and fifty-nine (39 %) isolates were PVL-positive. PVL-positive isolates were significantly more frequently isolated from skin or soft tissue than PVL-negative isolates, causing mainly subcutaneous abscesses and furuncles. Patients with PVL-positive CA-MRSA were significantly younger than patients with PVL-negative CA-MRSA. Eighty-seven percent of the PVL-positive isolates belonged to a limited number (n?=?7) of PFGE types belonging to sequence types (ST) ST80, ST8, ST30, ST5, ST152, ST338 and a new ST, a single-locus variant of ST1. A temporal evolution of the distribution of these PFGE types was observed, characterised by (1) the dissemination of the ST8-SCCmecIV arcA-positive (USA300) genotype and (2) a genetic diversification. Forty-seven (11 %) strains were TSST-1-positive, of which 65 % clustered into four PFGE types, all belonging to ST5. The epidemiology of CA-MRSA in Belgium is changing, as the rapid diffusion of the USA300 clone seems to occur, together with a clonal diversification. 相似文献
998.
Mariana Leandro Leandro Andrade Luciano Vespoli Julia Moreira Vivian Pimentel Fabiano Soares Lucas Passamani Vanildo Silveira Gonçalo de Souza Filho 《Research in microbiology》2021,172(1):103785
Plant growth-promoting bacteria are a promising alternative to improve agricultural sustainability. Gluconacetobacter diazotrophicus is an osmotolerant bacterium able to colonize several plant species, including sugarcane, coffee, and rice. Despite its biotechnological potential, the mechanisms controlling such osmotolerance remain unclear. The present study investigated the key mechanisms of resistance to osmotic stress in G. diazotrophicus. The molecular pathways regulated by the stress were investigated by comparative proteomics, and proteins essential for resistance were identified by knock-out mutagenesis. Proteomics analysis led to identify regulatory pathways for osmotic adjustment, de novo saturated fatty acids biosynthesis, and uptake of nutrients. The mutagenesis analysis showed that the lack of AccC protein, an essential component of de novo fatty acid biosynthesis, severely affected G. diazotrophicus resistance to osmotic stress. Additionally, knock-out mutants for nutrients uptake (Δtbdr and ΔoprB) and compatible solutes synthesis (ΔmtlK and ΔotsA) became more sensitive to osmotic stress. Together, our results identified specific genes and mechanisms regulated by osmotic stress in an osmotolerant bacterium, shedding light on the essential role of cell envelope and extracytoplasmic proteins for osmotolerance. 相似文献
999.
Rogier Thomas Eberl Isabelle Moretto Florian Sixt Thibault Catherine François-Xavier Estève Clémentine Abdallahoui Maroua Behague Lucile Coussement Antoine Mathey Lucas Mahy Sophie Buisson Marielle Salmon-Rousseau Arnaud Duong Michel Chavanet Pascal Bernard Quentin Nicolas Barbara Benguella Leila Bonnotte Bernard Blot Mathieu Piroth Lionel 《European journal of clinical microbiology & infectious diseases》2021,40(9):2023-2028
European Journal of Clinical Microbiology & Infectious Diseases - During an epidemic period, we compared patients hospitalized for initial suspicion of COVID-19 but for whom an alternative... 相似文献
1000.
Marine Mommert Magali Perret Matthew Hockin Sébastien Viel Alexandre Belot Jean-Christophe Richard Mehdi Mezidi Jean-Baptiste Fassier Etienne Javouhey ANTOINE Study Group COVID-SER Study Group COVID-HCL Study Group Andrew Hemmert François Mallet Sophie Trouillet-Assant Karen Brengel-Pesce 《European journal of immunology》2021,51(4):989-994
Low concentrations of type-I interferon (IFN) in blood seem to be associated with more severe forms of Coronavirus disease 2019 (COVID-19). However, following the type-I interferon response (IR) in early stage disease is a major challenge. We evaluated detection of a molecular interferon signature on a FilmArray® system, which includes PCR assays for four interferon stimulated genes. We analyzed three types of patient populations: (i) children admitted to a pediatric emergency unit for fever and suspected infection, (ii) ICU-admitted patients with severe COVID-19, and (iii) healthcare workers with mild COVID-19. The results were compared to the reference tools, that is, molecular signature assessed with Nanostring® and IFN-α2 quantification by SIMOA® (Single MOlecule Array). A strong correlation was observed between the IR measured by the FilmArray®, Nanostring®, and SIMOA® platforms (r-Spearman 0.996 and 0.838, respectively). The FilmArray® panel could be used in the COVID-19 pandemic to evaluate the IR in 45-min with 2 min hand-on-time at hospitalization and to monitor the IR in future clinical trials. 相似文献