全文获取类型
收费全文 | 31579篇 |
免费 | 2084篇 |
国内免费 | 101篇 |
专业分类
耳鼻咽喉 | 218篇 |
儿科学 | 982篇 |
妇产科学 | 742篇 |
基础医学 | 4789篇 |
口腔科学 | 530篇 |
临床医学 | 4194篇 |
内科学 | 6307篇 |
皮肤病学 | 584篇 |
神经病学 | 3273篇 |
特种医学 | 674篇 |
外科学 | 2517篇 |
综合类 | 201篇 |
一般理论 | 29篇 |
预防医学 | 3530篇 |
眼科学 | 572篇 |
药学 | 2248篇 |
1篇 | |
中国医学 | 101篇 |
肿瘤学 | 2272篇 |
出版年
2024年 | 31篇 |
2023年 | 298篇 |
2022年 | 588篇 |
2021年 | 998篇 |
2020年 | 607篇 |
2019年 | 824篇 |
2018年 | 983篇 |
2017年 | 706篇 |
2016年 | 783篇 |
2015年 | 987篇 |
2014年 | 1140篇 |
2013年 | 1776篇 |
2012年 | 2479篇 |
2011年 | 2665篇 |
2010年 | 1327篇 |
2009年 | 1243篇 |
2008年 | 2088篇 |
2007年 | 2105篇 |
2006年 | 2058篇 |
2005年 | 1904篇 |
2004年 | 1813篇 |
2003年 | 1653篇 |
2002年 | 1489篇 |
2001年 | 213篇 |
2000年 | 170篇 |
1999年 | 222篇 |
1998年 | 257篇 |
1997年 | 203篇 |
1996年 | 192篇 |
1995年 | 140篇 |
1994年 | 141篇 |
1993年 | 124篇 |
1992年 | 118篇 |
1991年 | 119篇 |
1990年 | 106篇 |
1989年 | 119篇 |
1988年 | 73篇 |
1987年 | 90篇 |
1986年 | 71篇 |
1985年 | 67篇 |
1984年 | 78篇 |
1983年 | 84篇 |
1982年 | 90篇 |
1981年 | 58篇 |
1980年 | 63篇 |
1979年 | 47篇 |
1978年 | 28篇 |
1977年 | 36篇 |
1976年 | 34篇 |
1974年 | 32篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
A S Brickman A L Trujillo M S Gutin M L Tuck 《The Journal of clinical endocrinology and metabolism》1987,64(2):297-303
ACTH-, angiotensin II (AII)-, and K+-mediated aldosterone responses in vitro are dependent on extracellular and intracellular Ca concentrations. This study examined in vivo the relationship of changes in ambient serum calcium (serum Ca) to ACTH- and AII-mediated aldosterone release in hypoparathyroid subjects. Plasma aldosterone (PA) responses to graded dose infusions of ACTH and AII were examined in hypoparathyroid (HypoPTH) patients before (n = 8) and after correction of hypocalcemia (n = 6) and compared to responses in 20 normotensive normocalcemic subjects. ACTH and AII were infused for 90 min at rates increasing from 12.5 to 50 mIU/30 min and 0.5 to 2.0 ng/kg X min, respectively. Pretreatment mean serum Ca was 6.8 +/- 0.2 (+/- SEM) mg/dl, and it rose to 9.3 +/- 0.2 mg/dl after 3-8 weeks of vitamin D administration. In the untreated HypoPTH patients, basal mean PA (5.4 +/- 1.3 ng/dl) was lower (P less than 0.01) than in the normal subjects (10.6 +/- 0.6 ng/dl) or treated HypoPTH patients (9.5 +/- 1.8 ng/dl). There was a marked reduction in PA responses to ACTH at all doses in the untreated HypoPTH patients compared to the normal subjects. With normalization of serum Ca in four patients, the mean peak PA response to ACTH (25.1 +/- 6.0 ng/dl) was not significantly different from normal (28.9 +/- 1.7 ng/dl). During graded dose AII infusion in five untreated HypoPTH patients, mean PA levels increased from 6.9 +/- 1.2 to 11.6 +/- 2.2 ng/dl; when the serum Ca was normal, the corresponding values were 8.7 +/- 1.8 and 20.2 +/- 3.61 ng/dl. There was a positive correlation (r = 0.475; P less than 0.05) between basal PA and serum Ca levels. In addition, maximum changes in mean arterial pressure in response to AII infusions were significantly greater after correction of hypocalcemia. These observations indicate that in HypoPTH patients, extracellular Ca concentrations can influence humoral aldosterone response to ACTH and AII and pressor responses to AII. 相似文献
32.
Kevin Gruffydd-Jones Sandra Hollinghurst Sabbi Ward Gordon Taylor 《The British journal of general practice》2005,55(521):918-923
BACKGROUND: There is a high non-attendance rate for traditional clinic-based routine asthma care in general practice. Alternative methods of providing routine asthma care need to be examined. AIM: To examine the cost and effectiveness of targeted routine asthma care in general practice using telephone triage, compared to usual clinic care. DESIGN OF STUDY: An open randomised controlled trial. SETTING: A single semi-rural practice in the southwest of England. METHOD: Adult patients with asthma were randomised to receive either their routine asthma care in the surgery or care by telephone triage. Asthma control parameters, health status and NHS resource utilisation were measured over the 12-month study period. RESULTS: One hundred and ninety-four patients were randomised and 35% per cent more patients (n = 84 versus n = 62) received more than one consultation in the telephone group. Asthma control as measured by the asthma control questionnaire (ACQ) was similar in the clinic and telephone groups: mean change in ACQ = -0.11 (95% CI = -0.32 to 0.11) versus -0.18 (95% CI = -0.38 to 0.02). Mean NHS costs were 210 pounds sterling per patient per year in the telephone group compared to 334 pounds sterling in the clinic group (P-value of bootstrapped difference = 0.071). CONCLUSION: Targeted routine asthma care by telephone triage of adult asthmatics can lead to more asthma patients being reviewed, at less cost per patient and without loss of asthma control compared to usual routine care in the surgery. 相似文献
33.
34.
Selene Dall' Acqua Coutinho José Daniel Fedullo Sandra Helena Corrêa 《Medical mycology》2006,44(4):383-387
The objective of this study was to determine the presence of different species of the genus Malassezia in the healthy external auditory canal of wild felids maintained in captivity. One hundred and thirty-two adult animals (264 samples of cerumen), 77 males (58.3%) and 55 females (41.7%), were studied: large felids (55 animals) - 26 lions (Panthera leo), 13 tigers (Panthera tigris), 6 leopards (Panthera pardus), 6 jaguars (Panthera onca), 2 cheetahs (Acinonyx jubatus), 2 pumas (Puma concolor); small felids (77 animals) - 29 tiger cats (Leopardus tigrinus), 19 jaguarundis (Herpailurus yagouaroundi), 10 margays (Leopardus wiedii), 9 pampas cats (Oncifelis colocolo), 6 geoffroy's cats (Oncifelis geoffroyi), and 4 servals (Leptailurus serval). Samples were obtained by the introduction of a sterile swab into the ear canal after cleaning the auricle with an alcohol-ether solution. The swabs were seeded onto Petri dishes containing modified Mycosel agar and sterile olive oil was added to the surface of the medium before specimen seeding. The plates were incubated at 35oC for two weeks. The isolates were analyzed regarding macro-and micromorphology and identified through catalase tests and growth on Tween 20, 40, 60 and 80. Malassezia spp. were isolated from 58 of the felids studied (43.9%) and from 102 samples of cerumen (38.6%). Malassezia sympodialis was isolated exclusively in large felids (33 animals-56.9%), and Malassezia pachydermatis exclusively in smaller varieties (25 animals - 43.1%). The incidence of fungi was higher in lions, with yeast being isolated in 25 of 26 animals (96.2%). Forty-eight strains (47.1%) were isolated from the right ear canal and 54 (52.9%) from the left. Although M. pachydermatis is the species considered a member of the microbiota of the mammalian external ear canal these results suggest that M. sympodialis participates in the microbiota of large felids. 相似文献
35.
Luisa Rocha Manola Cuellar-Herrera Marcos Velasco Francisco Velasco Ana-Luisa Velasco Fiacro Jiménez Sandra Orozco-Suarez Anna Borsodi 《Seizure》2007,16(7):645-652
Opioid receptor binding was evaluated in parahippocampal cortex (PHC) obtained from patients with intractable mesial temporal lobe epilepsy (MTLE) with and without subacute high frequency electrical stimulation (HFS) in this brain area. Mu, delta and nociceptin receptor binding was determined by autoradiography in PHC of five patients (ESAE group) with MTLE history of 14.8 +/- 2.5 years and seizure frequency of 11 +/- 2.9 per month, two of them (40%) with mesial sclerosis. This group demonstrated antiepileptic effects following subacute HFS (130 Hz, 450 micros, 200-400 microA), applied continuously during 16-20 days in PHC. Values were compared with those obtained from patients with severe MTLE (history of 21.7 +/- 2.8 years and seizure frequency of 28.2 +/- 14 per month) in whom electrical stimulation did not induce antiepileptic effects (ESWAE group, n = 4), patients with MTLE in whom no electrical stimulation was applied (MTLE group, n = 4) and autopsy material acquired from subjects without epilepsy (n = 4 obtained from three subjects). Enhanced 3H-DAMGO (MTLE, 755%; ESAE, 375%; ESWAE, 693%), 3H-DPDPE (MTLE, 242%; ESAE, 80%; ESWAE, 346%) and 3H-nociceptin (MTLE, 424%; ESAE, 217%; ESWAE, 451%) binding was detected in the PHC of all epileptic groups. However, tissue obtained from ESAE group demonstrated lower opioid receptor binding (3H-DAMGO, 44.5%, p < 0.05; 3H-DPDPE, 47%, p < 0.05; 3H-nociceptin, 39.3%, p < 0.5) when compared with MTLE group. The present results indicate that a high effectiveness to the antiepileptic effects induced by HFS is associated with reduced opioid peptide binding. 相似文献
36.
Sandra Fabian Heike Hesse Roland Grassme Ingo Bradl Annette Bernsdorf 《Pathophysiology》2005,12(4):281-287
The results of most reported studies show differences between the muscular activity of low back pain patients and healthy subjects, but the focus has usually been on trunk muscles only, and they have not involved work-related tests or exercises. The reintegration of chronic low back pain patients to job market is a common problem. Therefore assessment systems like the functional capacity evaluation (FCE) according to Isernhagen [S.J. Isernhagen, Work Injury: Management and Prevention, Aspen Publishers Inc., Gaithersburg, MD, 1988] are often used tools to determine the physical abilities and deficits of long-time incapacitated persons. The aim of the present study was to compare the healthy persons and chronic low back pain patients in performing a FCE-test and to analyse their muscular activation and motion patterns. The results indicate differences in the activation patterns of the groups in the test task “floor to waist lift” common in many occupations. 相似文献
37.
Sergi Sastre Francisco Maculé Sandra Lasurt Josep-María Segur Lluis Lozano Montse Nuñez Santiago Suso 《European journal of orthopaedic surgery & traumatology : orthopedie traumatologie》2007,17(4):393-397
Five patients with idiopathic transient osteoporosis were examined. Bone scanning and MRI was helpful in the diagnosis to differentiate of necrosis and all patients recovered completely with conservative and symptomatic treatment. There was no history of trauma in all patients. MRI was realized previously in all cases to confirm the diagnosis and after the resolution of symptomathology. 相似文献
38.
Sandra Urdaneta Hartmann Brian Wigdahl Elizabeth B Neely Cheston M Berlin Cara-Lynne Schengrund Hung-Mo Lin Mary K Howett 《Journal of human lactation》2006,22(1):61-74
Reduction of transmission of human immunodeficiency virus type 1 (HIV-1) through human milk is needed. Alkyl sulfates such as sodium dodecyl sulfate (SDS) are microbicidal against HIV-1 at low concentrations, have little to no toxicity, and are inexpensive. The authors have reported that treatment of HIV-1-infected human milk with < or = 1% (10 mg/mL) SDS for 10 minutes inactivates cell-free and cell-associated virus. The SDS can be removed with a commercially available resin after treatment without recovery of viral infectivity. In this article, the authors report results of selective biochemical analyses (ie, protein, immunoglobulins, lipids, cells, and electrolytes) of human milk subjected to SDS treatment and removal. The SDS treatment or removal had no significant effects on the milk components studied. Therefore, the use of alkyl sulfate microbicides to treat milk from HIV-1-positive women may be a simple, practical, and nutritionally sound way to prevent or reduce transmission of HIV-1 while still feeding with mother's own milk. 相似文献
39.
Blindsight is a visual phenomenon whereby hemianopic patients are able to process visual information in their blind visual field without awareness. Previous research demonstrating the existence of blindsight in hemianopic patients has been criticized for the nature of the paradigms used, for the presence of methodological artifacts, and for the possibility that spared islands of visual cortex may have sustained the phenomenon because the patients generally had small circumscribed lesions. To respond to these criticisms, the authors have been investigating for several years now residual visual abilities in the blind field of hemispherectomized patients in whom a whole cerebral hemisphere has been removed or disconnected from the rest of the brain. These patients have offered a unique opportunity to establish the existence of blindsight and to investigate its underlying neuronal mechanisms because in these cases, spared islands of visual cortex cannot be evoked to explain the presence of visual abilities in the blind field. In addition, the authors have been using precise behavioral paradigms, strict control for potential methodological artifacts such as light scatter, fixation, criterion effects, and macular sparing, and they have utilized new neuroimaging techniques such as diffusion tensor imaging tractography to enhance their understanding of the phenomenon. The following article is a review of their research on the involvement of the superior colliculi in blindsight in hemispherectomized patients. . 相似文献
40.
Sandra E. File 《Human psychopharmacology》1987,2(3):151-158
The clinical efficacy of the benzodiazepines in reducing anxiety is widely accepted. However, the search for novel anxiolytics continues, motivated by the hope of finding a non-sedative anxiolytic. This article reviews the pre-clinical evidence for new compounds as it relates both to their anxiolytic actions in animal tests and to their sedative potential. Drugs acting at sites on the GABA-benzodiazepine receptor complex are discussed, as well as the potential importance of aminergic and peptidergic pathways. 相似文献