全文获取类型
收费全文 | 201431篇 |
免费 | 3094篇 |
国内免费 | 82篇 |
专业分类
耳鼻咽喉 | 1323篇 |
儿科学 | 7612篇 |
妇产科学 | 3672篇 |
基础医学 | 20153篇 |
口腔科学 | 2434篇 |
临床医学 | 15151篇 |
内科学 | 35693篇 |
皮肤病学 | 1346篇 |
神经病学 | 18993篇 |
特种医学 | 9737篇 |
外国民族医学 | 2篇 |
外科学 | 31899篇 |
综合类 | 2564篇 |
一般理论 | 26篇 |
预防医学 | 20755篇 |
眼科学 | 3274篇 |
药学 | 11033篇 |
中国医学 | 661篇 |
肿瘤学 | 18279篇 |
出版年
2023年 | 285篇 |
2022年 | 535篇 |
2021年 | 1083篇 |
2020年 | 650篇 |
2019年 | 878篇 |
2018年 | 22729篇 |
2017年 | 17984篇 |
2016年 | 20178篇 |
2015年 | 1675篇 |
2014年 | 1790篇 |
2013年 | 2077篇 |
2012年 | 8784篇 |
2011年 | 22851篇 |
2010年 | 19721篇 |
2009年 | 12367篇 |
2008年 | 20857篇 |
2007年 | 23045篇 |
2006年 | 1822篇 |
2005年 | 3400篇 |
2004年 | 4531篇 |
2003年 | 5329篇 |
2002年 | 3390篇 |
2001年 | 626篇 |
2000年 | 742篇 |
1999年 | 473篇 |
1998年 | 401篇 |
1997年 | 384篇 |
1996年 | 245篇 |
1995年 | 258篇 |
1994年 | 222篇 |
1993年 | 162篇 |
1992年 | 290篇 |
1991年 | 339篇 |
1990年 | 374篇 |
1989年 | 328篇 |
1988年 | 274篇 |
1987年 | 281篇 |
1986年 | 229篇 |
1985年 | 232篇 |
1984年 | 213篇 |
1983年 | 152篇 |
1982年 | 117篇 |
1980年 | 133篇 |
1979年 | 150篇 |
1978年 | 142篇 |
1976年 | 127篇 |
1975年 | 107篇 |
1974年 | 138篇 |
1973年 | 142篇 |
1972年 | 108篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
991.
Robson C. Gutierre Mizue I. Egami Marta M. Antoniazzi Carlos Jared 《Comparative clinical pathology》2008,17(4):221-228
The caecilians (Amphibia, Gymnophiona) constitute one of the least known groups of terrestrial vertebrates because most species
live underground in quite inaccessible environments. Siphonops annulatus is an exclusively fossorial species and is the most extensively distributed caecilian in South America. Little is known of
this order concerning circulating granulocytes, including their morphological and cytochemical structure and ultrastructure.
This paper is part of a project covering the study of granulocytes in representative species of the order Amphibia. Blood
extensions were carried out and submitted to Leishman, Toluidine Blue, Periodic acid Schiff, Sirius Red and hydrogen o-toluidine peroxide methods. Part of the samples was prepared for conventional transmission electron microscopy. Among granular
leukocytes, mature and immature neutrophils and eosinophils were identified, plus basophils. The most frequent granulocyte
encountered in S. annulatus peripheral blood is the neutrophil. This is a cell with a hyper-segmented nucleus and with a very clear cytoplasm when compared
to the eosinophil, which presents large cytoplasmic acidophilic granules. On the other hand, the basophils present basophilic
and metachromatic granules. Glycogen was detected in the cytoplasm of the neutrophils and eosinophils, while basic protein
rich in amino acids was observed in the eosinophil’s granules. Myeloperoxidase activity was detected in the cytoplasm of the
neutrophils and eosinophils. Neutrophils were ultrastructurally detected with three types of small granules: eosinophils with
large and small spherical granules and basophils with large spherical granules with lamellate structures. 相似文献
992.
David P. Bazett-Jones Ren Li Eden Fussner Rosa Nisman Hesam Dehghani 《Chromosome research》2008,16(3):397-412
Electron microscopy has been the ‘gold standard’ of spatial resolution for studying the structure of the cell nucleus. Electron
spectroscopic imaging (ESI) offers advantages over conventional transmission electron microscopy by eliminating the need for
heavy-atom contrast agents. ESI also provides mass-dependent and element-specific information at high resolution, permitting
the distinguishing of structures that are primarily composed of protein, DNA, or RNA. The technique can be applied to understand
the structural consequences of epigenetic modifications, such as modified histones, on chromatin fiber morphology. ESI can
also be applied to elucidate the multifunctional behavior of subnuclear ‘organelles’ such as the nucleolus and promyelocytic
leukemia nuclear bodies.
The authors dedicate this paper to the memory of Ying Ren (1961–2007). We all benefited from knowing her. Our research advanced
through the technical creativity she provided. 相似文献
993.
994.
A 40-year-old woman presented with progressive lower leg pain and spontaneous toe movement. The EMG showed a posterior tibial nerve mononeuropathy and continuous myokymic discharges in posterior tibial-innervated muscles. The MRI revealed a markedly enlarged posterior tibial nerve. Toe movements and myokymia were unaffected by the proximal transection of the lesion but ceased abruptly when the distal end of the fusiform "tumor" was resected, suggesting that spontaneous electrical foci may have been located along the nerve lesion. The markedly enlarged nerve segment contained edematous, swollen fascicles with marked Schwann cell onion-bulb lesions and angiocentric, lymphocytic, and lymphofollicular infiltration. This nerve lesion is an example of a newly recognized entity called hypertrophic mononeuritis. 相似文献
995.
For seventeen years, a young man suffered from headaches of one to three days duration occurring once every six or seven days and totally disappearing between episodes. These were strictly unilateral (always on the left side), and were absolutely responsive to indomethacin. They differ clinically from the other two indomethacin-responsive headaches described up to now: Hemicrania Continua (HC) and Chronic Paroxysmal Hemicrania (CPH). He has a sister suffering from HC. Similar to HC, but unlike CPH, topical tyramine in our patient's eyes resulted in anisocoria before, but not after, indomethacin treatment. Our case differs from HC, however, in its time pattern; it could either be a pre-chronic stage of HC or a new type of headache. It seems unlikely that a time pattern that has remained unchanged for 17 years will become continuous, as in HC, in the future, and thus it is possible that our patient represents a case of a new type of headache that we propose to name "Hemicrania Episodica." In any case, it seems probable that this type of headache, although clinically different, may share a common pathogenic basis with HC. 相似文献
996.
997.
The constitutional gain-of-function variant p.Glu1099Lys in NSD2 is associated with a novel syndrome
Bernt Popp Melanie Brugger Sibylle Poschmann Tobias Bartolomaeus Maximilian Radtke Julia Hentschel Nataliya Di Donato Andreas Rump Janina Gburek-Augustat Elisabeth Graf Matias Wagner Ina Sorge Johannes R Lemke Thomas Meitinger Rami Abou Jamra Vincent Strehlow Theresa Brunet 《Clinical genetics》2023,103(2):226-230
998.
Wenjie Bi Anke Kraft Sophie Engelskircher Jasmin Mischke Moana Witte Frank Klawonn Marco van Ham Markus Cornberg Heiner Wedemeyer Julia Hengst Lothar Jänsch 《European journal of immunology》2023,53(11):2250291
Chronic hepatitis C virus (HCV) infections compromise natural killer (NK)-cell immunity. Direct-acting antivirals (DAA) effectively eliminate HCV, but the long-term effects on NK cells in cured patients are debated. We conducted a proteomic study on CD56+ NK cells of chronic HCV-infected patients before and 1 year after DAA therapy. Donor-variation was observed in NK-cell proteomes of HCV-infected patients, with 46 dysregulated proteins restored after DAA therapy. However, 30% of the CD56+ NK-cell proteome remained altered 1 year post-therapy, indicating a phenotypic shift with low donor-variation. NK cells from virus-negative cured patients exhibited global regulation of RNA-processing and pathways related to “stimuli response”, “chemokine signaling”, and “cytotoxicity regulation”. Proteomics identified downregulation of vesicle transport components (CD107a, COPI/II complexes) and altered receptor expression profiles, indicating an inhibited NK-cell phenotype. Yet, activated NK cells from HCV patients before and after therapy effectively upregulated IFN-γ and recruited CD107a. Conversely, reduced surface expression levels of Tim-3 and 2B4 were observed before and after therapy. In conclusion, this study reveals long-term effects on the CD56+ NK-cell compartment in convalescent HCV patients 1 year after therapy, with limited abundance of vesicle transport complexes and surface receptors, associated with a responsive NK-cell phenotype. 相似文献
999.
Chlorhexidine susceptibility and Eagle effect in planktonic cells and biofilm of nosocomial isolates
Marchi Ana Paula Farrel Côrtes Marina Vásconez Noguera Saidy Rossi Flavia Levin Anna Sara Figueiredo Costa Silvia Perdigão Neto Lauro Vieira 《European journal of clinical microbiology & infectious diseases》2023,42(6):787-792
European Journal of Clinical Microbiology & Infectious Diseases - The aim of this study is to evaluate the chlorhexidine gluconate (CHG) susceptibility in both planktonic cells and biofilm of... 相似文献
1000.
Nausicaa Christodoulou Léa Bertrand Laura Palagini Justine Frija-Masson Marie-Pia d'Ortho Michel Lejoyeux Dieter Riemann Julia Maruani Pierre A. Geoffroy 《Journal of sleep research》2023,32(1):e13752
Insomnia is the most frequent sleep disorder and a public health concern that increased during the Covid 19 pandemic. Fully restrictive lockdowns during Covid are interesting periods to examine the impact of environmental and behavioural changes on the emergence of insomnia symptoms. In this cross-sectional study we aimed to (1) determine the main factors associated with insomnia symptoms during a Covid-19 fully restrictive lockdown examining the associated daily life alterations and (2) create a predictive model of insomnia symptoms. We used the data drawn from the “Covid-RythmE” study that reached volunteers from the general French population through an online survey during the last 2 weeks of the 2 month full lockdown. Associations with insomnia symptoms were tested and significant associations were entered in a Backward Stepwise Logistic Regression (BSLR) to assess the best combination to classify individuals with or without insomnia symptoms. From the 1624 participants, 50.64% suffered from mild to severe insomnia symptoms as assessed by the ISI. The best combination for explaining insomnia symptoms with 74.26% of accuracy included: age (OR = 1.15), females (OR = 1.26), smaller home sizes (OR = 0.77), environmental noises (OR = 1.59), anxiety symptoms (OR = 1.24), depressive symptoms (OR = 1.15), regularity of sleep–wake schedules (OR = 1.25), exposure to screen during the morning (OR = 1.13), and LED light during the evening (OR = 1.17). Thus, lifestyle schedule and exposure to natural synchronizers such as light, are primordial in considering in insomnia physiopathology, prevention and treatment, as well as the associated mental health status. 相似文献