全文获取类型
收费全文 | 28244篇 |
免费 | 2550篇 |
国内免费 | 43篇 |
专业分类
耳鼻咽喉 | 305篇 |
儿科学 | 1094篇 |
妇产科学 | 615篇 |
基础医学 | 3609篇 |
口腔科学 | 427篇 |
临床医学 | 3514篇 |
内科学 | 4764篇 |
皮肤病学 | 500篇 |
神经病学 | 2806篇 |
特种医学 | 813篇 |
外国民族医学 | 1篇 |
外科学 | 3983篇 |
综合类 | 627篇 |
一般理论 | 23篇 |
预防医学 | 3452篇 |
眼科学 | 430篇 |
药学 | 2077篇 |
中国医学 | 44篇 |
肿瘤学 | 1753篇 |
出版年
2023年 | 235篇 |
2022年 | 337篇 |
2021年 | 790篇 |
2020年 | 433篇 |
2019年 | 753篇 |
2018年 | 877篇 |
2017年 | 619篇 |
2016年 | 597篇 |
2015年 | 682篇 |
2014年 | 941篇 |
2013年 | 1329篇 |
2012年 | 1904篇 |
2011年 | 1959篇 |
2010年 | 1082篇 |
2009年 | 945篇 |
2008年 | 1526篇 |
2007年 | 1529篇 |
2006年 | 1467篇 |
2005年 | 1445篇 |
2004年 | 1297篇 |
2003年 | 1234篇 |
2002年 | 1183篇 |
2001年 | 654篇 |
2000年 | 580篇 |
1999年 | 496篇 |
1998年 | 239篇 |
1997年 | 198篇 |
1996年 | 235篇 |
1995年 | 175篇 |
1994年 | 173篇 |
1993年 | 150篇 |
1992年 | 360篇 |
1991年 | 358篇 |
1990年 | 368篇 |
1989年 | 326篇 |
1988年 | 266篇 |
1987年 | 283篇 |
1986年 | 218篇 |
1985年 | 251篇 |
1984年 | 205篇 |
1983年 | 159篇 |
1982年 | 136篇 |
1981年 | 106篇 |
1980年 | 117篇 |
1979年 | 171篇 |
1978年 | 143篇 |
1977年 | 108篇 |
1976年 | 101篇 |
1974年 | 128篇 |
1973年 | 110篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
31.
Alexander L Green Erlick A C Pereira Dominic Kelly Peter G Richards Michael G Pike 《Journal of clinical neuroscience》2007,14(11):1049-1054
All 253 children receiving neurosurgical intervention for hydrocephalus (HCP) at a single British Neurosurgical Unit over a decade were investigated by retrospective case note review. Referral rates and mean age at presentation remained stable throughout, as did proportions of children presenting due to myelomeningocoele or meningitis. Comparing the first and second halves of the decade, the predominant aetiologies (intraventricular haemorrhage [IVH] at <1 year and brain tumour at 1-16 years) reduced from comprising half (70/129) of all cases to just over one-third (43/124). Other significant changes included a 45% reduction in neonatal IVH and a 179% increase in rare miscellaneous disorders. Outcome after 4 years of follow-up for all patients showed 44.4% without deficit, 11.9% with non-cognitive neurological deficits only, 11.5% with cognitive impairment only, 13.5% with both cognitive and neurological impairments, and 15.5% mortality. 相似文献
32.
Scott W. Powers Kelly C. Byars Monica J. Mitchell Susana R. Patton Teresa Schindler Margaret H. Zeller 《Children's Health Care》2003,32(4):297-311
This pilot study examined a behavioral treatment to increase calorie intake in toddlers with cystic fibrosis. Eight toddlers were randomly assigned to behavioral plus nutrition (BEH) or nutrition intervention (NTR) conditions. Calorie intake and weight were measured at pre- and posttreatment. The BEH group showed a trend for changes in calorie intake pre- to posttreatment (p = .07; 40% increase). Results for the BEH and NTR groups did not differ significantly. Most participants achieved weight gains consistent with normal growth. Seventy-five percent had not shown this pattern during the year prior to intervention. These results support the feasibility and potential for behavioral interventions in this age group. 相似文献
33.
The correct timing of surgery in cases of gallstone pancreatitis is debatable. To delineate more clearly the influence of the timing of surgery in the treatment of the disease, a prospective randomized clinical study of early surgery (less than 48 hours after admission) and delayed surgery (more than 48 hours after admission) was conducted in 165 patients. Ranson's prognostic signs of severity of disease were used to classify the patients into two risk groups: mild pancreatitis (three or fewer positive signs) and severe pancreatitis (more than three positive signs). In patients with three or fewer positive Ranson's signs, the time of surgery appeared to have little effect on the outcome, whereas in patients with more than three positive signs, early surgery resulted in a significant increase in rates of morbidity and mortality. Controlled randomization showed that in patients with gallstone pancreatitis, edematous or hemorrhagic necrotizing pancreatitis can develop, with or without impacted stones, early or late in the progression of the disease, during early or delayed surgery. These findings suggest that (1) although a gallstone initiates a bout of pancreatitis, it does not cause the progression of the disease; (2) the fate of the progression of pancreatitis is decided early by the amount of digestive enzymes being activated; (3) early removal of an impacted stone does not ameliorate the progression of pancreatitis; and (4) surgery should be performed during the initial hospital admission after the pancreatitis has subsided. 相似文献
34.
Prolactin and growth hormone receptors 总被引:2,自引:0,他引:2
35.
P. Brouqui C. Le Cam P. J. Kelly R. Laurens A. Tounkara S. Sawadogo V lo-Marcel L. Gondao B. Faugere J. Delmont A. Bourgeade Prof. D. Raoult 《European journal of epidemiology》1994,10(6):695-698
Human ehrlichiosis is a recently recognized rickettsial disease. It is caused byEhrlichia chaffeensis, an intraleucocytic Gram-negative, obligate intracellular bacterium, grouped within the genusEhrlichiae. Most human cases of ehrlichiosis have been diagnosed in the USA. Two cases have been reported outside of the USA, one in Europe and one in Africa. From 1 January to 30 June 1992, 765 sera from blood donors or other asymptomatic subjects in 8 African countries, including Ivory Coast, Burkina Faso, Mali, Central African Republic, Angola, Zimbabwe, Mozambique and Commores Islands, were tested by indirect immunofluorescence for the presence ofE. chaffeensis antibodies. Positive sera were confirmed by Western immunoblotting. Only two of 765 sera tested were positive. One serum obtained from Burkina Faso had an IgG titer of 1:200 and one from Mozambique had an IgG titer of 1:80. Human ehrlichiosis seems to occur infrequently in Africa, although many more sera from additional African countries need to be evaluated. 相似文献
36.
Effects of age and age-related hearing loss on the neural representation of speech cues. 总被引:6,自引:0,他引:6
OBJECTIVE: To examine the effects of aging and age-related hearing loss on the perception and neural representation of a time-varying speech cue. METHODS: P1, N1 and P2 cortical responses were recorded from younger and older normal-hearing adults, as well as older adults with age-related hearing loss. Synthetic speech tokens representing 10 ms increments along a /ba/-/pa/ voice-onset-time (VOT) continuum were used to evoke the responses. Each participant's ability to discriminate the speech tokens was also assessed. RESULTS: Compared with younger participants, older adults with and without hearing loss had more difficulty discriminating 10 ms VOT contrasts. In addition, both older groups elicited abnormal neural response patterns. There were no significant age-related findings for P1 latency; however, N1 latencies were prolonged for both older groups in response to stimuli with increased VOT durations. Also, P2 latencies were delayed for both older groups. The presence of age-related hearing loss resulted in a significant increase in N1 amplitude in response to voiceless stimuli. CONCLUSIONS: Aging and age-related hearing loss alter temporal response properties in the central auditory system. Because both older groups had difficulty discriminating these same speech stimuli, we conclude that some of the perceptual difficulties described by older adults might be due to age-related changes regulating excitatory and inhibitory processes. SIGNIFICANCE: Some of the speech understanding difficulties expressed by elderly adults may be related to impaired temporal precision in the aging auditory system. This might explain why older adults frequently complain that wearing a hearing aid makes speech louder, but does not necessarily improve their ability to understand speech. 相似文献
37.
Abstract: Most individuals concerned about hereditary breast cancer risk will neither order nor benefit from genetic testing at the present time. Many will, however, seek information about their risk and testing. Risk assessment services, in addition to providing information about hereditary risk and genetic testing, need also to include assessment of non-hereditary risks, information about how to evaluate risks, early detection modalities, the etiology of cancer, and assistance in devising follow-up health care plans. Psychosocial factors, particularly those pertaining to the individual's past history with illness and beliefs about causes and prognosis, must be taken into account to provide relevant information that is understood. A case history with examples of some of the types of information that lead to informed consent in a cancer risk assessment setting is provided. 相似文献
38.
Which nutrients are processed by a poorly perfused gut? 总被引:1,自引:0,他引:1
Kelly A Tappenden 《Nutrition in clinical practice》2003,18(4):294-296
39.
40.
In order to determine the effects of the Fowler-Stephens orchiopexy (FSO) on fertility, young rats underwent simulated FSO, FSO and concurrent contralateral orchiectomy (FSO/OR), unilateral orchiectomy (OR), or sham operation (controls). Twelve weeks after the operation, each male rat was mated to two proven-fertile female rats for 17 days (three ovulatory cycles). Two weeks later, both male and female rats were killed. No pregnancy resulted from the matings of the FSO/OR males. In contrast, pregnancy ensued in 13 of 16 (81%) females in the FSO group, 9 of 14 (64%) in the OR group, and 11 of 12 (92%) in the control group. There were no fertile males in the FSO/OR group. In the FSO group, eight of eight males induced pregnancy in at least one female; in the OR group, six of seven (86%) males were fertile as were all six males in the control group. No differences in litter size or fetal weight were observed between fertile females in various groups. 相似文献