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51.
P G Holt 《American journal of industrial medicine》1987,12(6):711-716
The features of the cotton dust syndrome which need to be considered when formulating a hypothesis on mechanism(s) are: 1) the presence of fever, 2) the "Monday effect," 3) the slow onset of forced expiratory volume in 1 second (FEV1) changes, and 4) the presence of bronchitis in chronic sufferers but the absence of emphysema or fibrosis. The main hypotheses concerning the mechanisms are direct release of histamine triggered by cotton dust components, immune reactions (principally antibody mediated) to cotton dust antigens, and inflammatory response(s) triggered by endotoxins released from bacterial contaminants on the dust. While histamine release and immune reactions may occur as a result of cotton dust inhalation, it is suggested that they are of secondary importance in comparison to inflammation. Evidence is reviewed that implicates bacterial lipopolysaccharide (LPS) present in the dust as the principal etiologic agent in this process. It is postulated that LPS inhalation stimulates a secretory response by lung macrophages, involving the release of effector molecules which trigger coagulation, bronchoconstriction, fever, and mucus production. LPS-induced macrophage secretory products also promote the local sequestration and activation of both neutrophils and platelets, which serve to amplify the inflammatory response. Evidence is presented implicating both interstitial and alveolar macrophages in this process. The problems associated with the identification of "high risk" groups of cotton workers will be discussed, from a number of viewpoints; consideration will be given to the role of a variety of environmental factors (including tobacco smoking) in this context, as well as possible genetic factors.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
52.
C B Styles S Holt K L Bowes R Hooper 《Journal of the Canadian Association of Radiologists》1984,35(1):31-33
Esophageal transit scintigraphy and esophageal manometry were compared in forty-two patients with symptoms of esophageal disease. Fifteen healthy volunteers were studied as a control group for the scintigraphic investigation. Agreement between the tests was present in 79% of patients. In all the five patients in whom the esophageal manometry was abnormal and the esophageal transit study was normal, the manometric finding was "giant esophageal contractions." In four of the control group an abnormal transit pattern was observed on one of two esophageal studies. Esophageal transit scintigraphy has some limitations as a screening test for esophageal motor dysfunction. 相似文献
53.
In light of recent developments within both health care and robotics, the use of robots within the human body has become attainable. Here we discuss the milestones for the realization of autonomous microrobots in medical applications. The desired tasks were classified by identifying the difficulties and requirements faced by the robot. In addition, we classified the levels of autonomy seen in microrobots for these uses. The aim of this article is to provide readers with a good understanding of the current state and future possibilities in this field. 相似文献
54.
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56.
Chan Curtis Bavinton Benjamin R. Prestage Garrett E. Broady Timothy R. Mao Limin Rule John Wilcock Ben Holt Martin 《Archives of sexual behavior》2022,51(5):2509-2521
Archives of Sexual Behavior - Changes to how gay, bisexual, and other men who have sex with men (GBM) connect with each other and with their communities have implications for HIV prevention. Social... 相似文献
57.
A mouse model of AChR deficiency syndrome with a phenotype reflecting the human condition 总被引:2,自引:0,他引:2
Cossins J Webster R Maxwell S Burke G Vincent A Beeson D 《Human molecular genetics》2004,13(23):2947-2957
The two subtypes of mammalian muscle nicotinic acetylcholine receptors (AChR) are generated by the substitution of the epsilon (adult) subunit for the gamma (fetal) subunit within the AChR pentamer. Null mutations of the adult AChR epsilon-subunit gene are the most common cause of the AChR deficiency syndrome. This is a disorder of neuromuscular transmission characterized by non-progressive fatigable muscle weakness present throughout life. In contrast with the human disorder, mice with AChR epsilon-subunit null mutations die between 10 and 14 weeks of age. We generated transgenic mice that constitutively express the human AChR gamma-subunit in an AChR epsilon-subunit 'knock-out' background. These mice, in which neuromuscular transmission is mediated by fetal AChR, live well into adult life but show striking similarities to human AChR deficiency syndrome. They display fatigable muscle weakness, reduced miniature endplate potentials and endplate potentials, reduced motor endplate AChR number and altered endplate morphology. Our results illustrate how species differences in the control of ion-channel gene expression may affect disease phenotype, demonstrate that expression of adult AChR subtype is not essential for long-term survival, and suggest that in patients with AChR deficiency syndrome, up-regulation of the gamma-subunit could be a beneficial therapeutic strategy. 相似文献
58.
I W Iglehart J D Sutton J C Bender R A Shaw C M Ziminski P A Holt M C Hochberg T M Zizic E W Engle M B Stevens 《The Journal of rheumatology》1990,17(2):159-162
This prospective, double blind study was undertaken to test the efficacy of intravenous "minipulse" (100 mg) methylprednisolone (MP) therapy versus standard pulse (1000 mg) MP therapy in rheumatoid arthritis (RA). Thirty-six patients with RA synovitis flares were randomized to receive either 100 or 1000 mg MP IV QD x 3 doses. These 2 universally comparable groups exhibited no statistically significant differences in their striking prompt and sustained clinical improvement. These data suggest that minipulse MP is as efficacious as conventional pulse MP in the treatment of RA flares. 相似文献
59.
Gladys Morales Samuel Durán-Agüero Solange Parra-Soto Leslie Landaeta-Díaz Valeria Carpio Brian Cavagnari Israel Rios-Castillo Edna Nava-González Jhon Bejarano-Roncancio Beatriz Núñez-Martínez Karla Cordón-Arrivillaga Eliana Meza-Miranda Saby Mauricio-Alza Georgina Gómez Gabriela Murillo Jacqueline Araneda-Flores 《American journal of human biology》2023,35(8):e23900
60.
Quirk P Ward LC Thomas BJ Holt TL Shepherd RW Cornish BH 《Clinical nutrition (Edinburgh, Scotland)》1995,14(6):348-353
The use of multiple frequency bioelectrical impedance analysis (MFBIA) was compared with single frequency bioelectrical impedance analysis (SFBIA) and anthropometry to estimate the size of the body cell mass (BCM) in a paediatric cystic fibrosis population. BCM was independently determined from the accepted gold standard reference of total body potassium (TBK). MFBIA was used to measure the impedance of the body at 248 frequencies from 4 kHz to 1 MHz. Data were analysed using Cole-Cole plots of reactance versus resistance. The limits of agreement procedure was used to determine the reliability and precision of the different techniques to predict values for TBK, in an individual subject. The results indicate that MFBIA with a precision of 12% offers little improvement over single frequency BIA but is better and more accurate than anthropometry for the prediction of TBK in an individual patient. 相似文献