全文获取类型
收费全文 | 8580篇 |
免费 | 740篇 |
国内免费 | 14篇 |
专业分类
耳鼻咽喉 | 74篇 |
儿科学 | 290篇 |
妇产科学 | 242篇 |
基础医学 | 1201篇 |
口腔科学 | 102篇 |
临床医学 | 895篇 |
内科学 | 1537篇 |
皮肤病学 | 85篇 |
神经病学 | 1289篇 |
特种医学 | 161篇 |
外科学 | 957篇 |
综合类 | 124篇 |
一般理论 | 9篇 |
预防医学 | 1087篇 |
眼科学 | 179篇 |
药学 | 507篇 |
中国医学 | 10篇 |
肿瘤学 | 585篇 |
出版年
2023年 | 183篇 |
2022年 | 262篇 |
2021年 | 540篇 |
2020年 | 314篇 |
2019年 | 383篇 |
2018年 | 355篇 |
2017年 | 253篇 |
2016年 | 272篇 |
2015年 | 314篇 |
2014年 | 349篇 |
2013年 | 442篇 |
2012年 | 589篇 |
2011年 | 531篇 |
2010年 | 276篇 |
2009年 | 234篇 |
2008年 | 369篇 |
2007年 | 422篇 |
2006年 | 369篇 |
2005年 | 305篇 |
2004年 | 287篇 |
2003年 | 229篇 |
2002年 | 214篇 |
2001年 | 124篇 |
2000年 | 112篇 |
1999年 | 131篇 |
1998年 | 51篇 |
1997年 | 50篇 |
1996年 | 62篇 |
1995年 | 41篇 |
1994年 | 42篇 |
1993年 | 33篇 |
1992年 | 89篇 |
1991年 | 83篇 |
1990年 | 93篇 |
1989年 | 85篇 |
1988年 | 64篇 |
1987年 | 74篇 |
1986年 | 66篇 |
1985年 | 67篇 |
1984年 | 37篇 |
1983年 | 27篇 |
1982年 | 25篇 |
1980年 | 25篇 |
1979年 | 34篇 |
1976年 | 24篇 |
1975年 | 26篇 |
1974年 | 30篇 |
1973年 | 31篇 |
1972年 | 34篇 |
1971年 | 22篇 |
排序方式: 共有9334条查询结果,搜索用时 15 毫秒
1.
Rachel A. Woolrich Myra J. Cooper Hannah M. Turner 《Cognitive therapy and research》2006,30(6):735-748
Objective: The study explored the semantic content and origins of negative self-beliefs, and their functional links to “not eating enough” and other behaviors, in participants with anorexia nervosa (AN). Method: Fifteen women meeting DSM-IV criteria for AN were compared with 17 dieting and 18 non-dieting women matched on age and number of years of education. The main outcome measure was a semi-structured interview. Results: Six themes were identified in the beliefs of participants with AN. These were, in order of decreasing frequency, powerlessness (present in all but three AN participants), failure, defectiveness, unattractiveness, worthlessness and emptiness. Importantly, powerlessness and failure beliefs were consistently present independent of Beck Depression Inventory-II scores. The negative early life experiences associated with these beliefs had high distress and responsibility ratings. Participants with AN reported that they employed specific behaviors, particularly ‘not eating enough,’ and ‘placating others,’ to try to reduce the cognitive and emotional impact of their negative self-beliefs. Discussion: The findings are discussed in relation to the role of powerlessness and the function of “not eating enough” in cognitive theory and therapy for AN.
相似文献
相似文献
2.
Antony E. Shrimpton Robert L. Schelper Reinhold P. Linke John Hardy Richard Crook Dennis W. Dickson Takashi Ishizawa Richard L. Davis 《Neuropathology》2007,27(3):228-232
Over 100 mutations in the presenilin‐1 gene (PSEN1) have been shown to result in familial early onset Alzheimer disease (EOAD), but only a relatively few give rise to plaques with an appearance like cotton wool (CWP) and/or spastic paraparesis (SP). A family with EOAD, seizures and CWP was investigated by neuropathological study and DNA sequencing of the PSEN1 gene. Aβ was identified in leptomeningeal vessels and in cerebral plaques. A single point mutation, p.L420R (g.1508T > G) that gives rise to a missense mutation in the eighth transmembrane (TM8) domain of PS1 was identified in two affected members of the family. p.L420R (g.1508T > G) is the mutation responsible for EOAD, seizures and CWP without SP in this family. 相似文献
3.
Eric W. Dickson MD Gary V. Doern PhD Leo Trevino PhD Michelle Mazzoni PhD Stephen O. Heard MD 《Academic emergency medicine》2003,10(10):1019-1023
OBJECTIVES: Patients undergoing emergent endotracheal intubation are at increased risk for developing pneumonia. Although numerous strategies have been investigated to reduce ventilator-associated pneumonia (VAP), the incidence of VAP and its associated mortality remains high. This investigation tested the hypothesis that LiquiVent (Alliance Pharmaceutical, San Diego, CA-LV) delivered antibiotics (via spray-dried microspheres-SDM) would improve survival in a rat model of descending gram-negative pneumonia. METHODS: Wistar rats (n = 49) were randomized to receive prophylaxis with 1). nothing (controls); 2). intramuscular (IM) tobramycin, 3). intratracheal LV plus SDM shells (vehicle), 4). intratracheal LV plus SDM shells plus IM tobramycin, or 5). intratracheal LV plus SDM containing 1 mg/kg of tobramycin. All interventions were given 24 hours before a bacterial challenge with 10(8) colony-forming units of intratracheal Klebsiella pneumoniae. Mortality at ten days was the sole outcome measure. Survival in individual groups was compared with controls by Fisher's exact test with Bonferroni correction for multiple comparisons. RESULTS: All animals in the control group died of pneumonia within ten days of bacterial inoculation (0% survival). Prophylaxis with either IM tobramycin or SDM vehicle plus IM tobramycin provided no protection (0% survival). This is in sharp contrast to the cohort receiving pretreatment with tobramycin-containing SDM delivered via LV, in which 60% of the animals survived to study completion (p < 0.05). CONCLUSIONS: Prophylaxis with SDM containing antibiotics delivered in low-dose LV provided significant protection in a rat model of descending gram-negative pneumonia. These data support the hypothesis that perfluorocarbon-delivered intratracheal antimicrobials may be useful in the prevention of VAP. 相似文献
4.
Familial expansile osteolysis: a morphological, histomorphometric and serological study. 总被引:1,自引:0,他引:1
Biopsies from the diseased bones of patients with familial expansile osteolysis (FEO) were examined by light and electron microscopy. Focal concentrations of multinuclear osteoclasts were present, and these contained viral-like microcylindrical inclusions which appeared exclusive to their nuclei. No consistent relationship was found between osteoclast size and the number of osteoclast nuclei containing microcylindrical inclusions. Quantitative histomorphometry showed evidence of increased bone remodelling with high bone cell densities and a decrease of the reversal period in bone remodelling. The lesions contained prominent woven bone and fibrovascular tissue, together with mononuclear cells and adipocytes. Little bone was found in the most radiolucent lesions, which were almost totally occupied by adipocytes and fibrovascular tissue. Serology did not reveal any significant differences between the viral antibody titres of patients and their age- and sex-matched controls. The present study suggests that intranuclear viral-like microcylindrical inclusions of osteoclasts are not a specific feature of Paget's disease, and are found in other disorders of osteoclast function, including pycnodysostosis, osteopetrosis, giant cell tumours, and familial expansile osteolysis. 相似文献
5.
6.
7.
8.
9.
We report two cases of colorectal carcinoma in children with a delay in diagnosis due to the low index of suspicion of this pathology as the cause of presenting symptoms. We conclude that any child presenting with unexplained rectal bleeding and abdominal pain should be investigated with endoscopy and barium enema. 相似文献
10.
Diagnostic accuracy has been addressed previously for Parkinson's disease in a brain bank collection, but accuracy of progressive supranuclear palsy (PSP) has not been addressed in a similar setting. Clinical and genetic features of pathologically confirmed cases of PSP were compared with misdiagnosed cases to determine ways to improve diagnostic accuracy. Medical records were reviewed for 180 cases sent to the Society of Progressive Supranuclear Palsy Brain Bank that had standardized neuropathologic evaluations as well as determination of apolipoprotein E and tau genotypes. Of the 180 cases studied, 137 had PSP and 43 had other pathologic diagnoses. Corticobasal degeneration (CBD), multiple system atrophy (MSA), and diffuse Lewy body disease (DLBD) accounted for 70% of the misdiagnosed cases. History of tremor, psychosis, dementia, and asymmetric findings were more frequent in misdiagnosed cases. The frequency of H1 tau haplotype (93 vs. 80%) and H1H1 genotype (86 vs. 66%) were significantly greater and APOE epsilon4 carrier state was significantly less (17 vs. 41 %) in PSP compared with misdiagnosed cases. Pathologic evaluation of clinically diagnosed PSP remains important for definitive diagnosis, and CBD, MSA, and DLBD are the disorders most likely to be misdiagnosed as PSP. Tremor, psychosis, early dementia, asymmetric findings, absence of H1 haplotype, and presence of APOE epsilon4 should raise questions about a diagnosis of PSP. 相似文献