全文获取类型
收费全文 | 44115篇 |
免费 | 2897篇 |
国内免费 | 446篇 |
专业分类
耳鼻咽喉 | 707篇 |
儿科学 | 507篇 |
妇产科学 | 648篇 |
基础医学 | 7418篇 |
口腔科学 | 981篇 |
临床医学 | 3699篇 |
内科学 | 8366篇 |
皮肤病学 | 1915篇 |
神经病学 | 3278篇 |
特种医学 | 2870篇 |
外国民族医学 | 1篇 |
外科学 | 5250篇 |
综合类 | 202篇 |
现状与发展 | 1篇 |
一般理论 | 7篇 |
预防医学 | 2053篇 |
眼科学 | 905篇 |
药学 | 4458篇 |
中国医学 | 645篇 |
肿瘤学 | 3547篇 |
出版年
2024年 | 29篇 |
2023年 | 326篇 |
2022年 | 1104篇 |
2021年 | 1744篇 |
2020年 | 830篇 |
2019年 | 1157篇 |
2018年 | 1347篇 |
2017年 | 1145篇 |
2016年 | 1677篇 |
2015年 | 2215篇 |
2014年 | 2596篇 |
2013年 | 2848篇 |
2012年 | 4230篇 |
2011年 | 4034篇 |
2010年 | 2325篇 |
2009年 | 2009篇 |
2008年 | 2717篇 |
2007年 | 2486篇 |
2006年 | 2183篇 |
2005年 | 2009篇 |
2004年 | 1567篇 |
2003年 | 1356篇 |
2002年 | 1134篇 |
2001年 | 834篇 |
2000年 | 757篇 |
1999年 | 549篇 |
1998年 | 228篇 |
1997年 | 154篇 |
1996年 | 126篇 |
1995年 | 95篇 |
1994年 | 100篇 |
1993年 | 83篇 |
1992年 | 155篇 |
1991年 | 172篇 |
1990年 | 180篇 |
1989年 | 147篇 |
1988年 | 125篇 |
1987年 | 114篇 |
1986年 | 97篇 |
1985年 | 74篇 |
1984年 | 49篇 |
1983年 | 39篇 |
1982年 | 29篇 |
1981年 | 38篇 |
1979年 | 30篇 |
1978年 | 22篇 |
1977年 | 23篇 |
1975年 | 18篇 |
1974年 | 19篇 |
1970年 | 23篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
Airway hyperresponsiveness (AHR) is a characteristic feature of asthma, but is also frequently demonstrated by children and adults with chronic obstructive lung diseases. AHR is usually measured by bronchial challenges using direct or indirect stimuli. The aim of this study was to compare these two types of bronchial challenge in children with post-infectious bronchiolitis obliterans (BO). Methacholine and adenosine 5'-monophosphate (AMP) challenges were used as tools for the evaluation of AHR to direct and indirect stimuli, respectively, in children with post-infectious BO (n = 28). These results were compared with those of asthmatic (n = 30) and control children (n = 25). Altogether, twenty-two patients (78.6%) with post-infectious BO were hyperreactive to methacholine with a provocative concentration causing a 20% fall in forced expiratory volume in one second (PC20) of <16 mg x mL(-1), but only six (21.4%) were hyperreactive to AMP with a PC20 of <200 mg x mL(-1). All patients with asthma responded positively to methacholine, and most (28, 93.3%) also responded positively to AMP. The majority of controls were insensitive to both challenges. Airway hyperresponsiveness to methacholine is a frequent, but by no means universal, finding in children with post-infectious bronchiolitis obliterans, but is usually not accompanied by airway hyperresponsiveness to adenosine 5'-monophosphate. This finding suggests that airway hyperresponsiveness in patients with post-infectious bronchiolitis obliterans has characteristics that differ from those of asthmatic subjects. 相似文献
62.
63.
We describe the enhancement patterns of myoepithelioma in two patients with a soft palate mass. In the first case, helical CT revealed a faintly enhancing mass. Histologically, the tumor was composed of plasmacytoid cells in a background of rich myxoid stroma. Immunostaining for CD34 showed scanty blood vessels. In the second case, helical CT revealed an intensely enhancing mass. Histologically, the mass was a cellular tumor with fibrous stroma. Immunostaining for CD34 also showed frequent blood vessels. 相似文献
64.
Nephron Sparing Surgery for De Novo Renal Cell Carcinoma in an Allograft Kidney: A Case Report 总被引:1,自引:0,他引:1
Kyun II Park Hitoshi Inoue Choi Jan Kim Tadao Tomoyoshi 《International journal of urology》1997,4(6):611-614
De novo renal cell carcinoma in a renal allograft is rare and has special implications in renal transplant recipients. We describe a patient with a renal allograft who developed a de novo renal cell carcinoma in the functioning renal allograft 258 months after transplantation. The patient underwent enucleation of the tumor because preoperative MRI showed it was well-encapsulated. A DNA banding study showed that the tumor originated from the donor. Indications for conservative renal surgery in renal cell carcinoma have been increasing. Accordingly, 1 option in the treatment of de novo renal cell carcinoma in a functioning renal allograft is enucleation as a method of nephron sparing surgery. 相似文献
65.
Rett's syndrome(RS) is a progressive neurodegenerative disorder characterized by exclusive occurrence in females, autistic behavior, dementia, gait ataxia, loss of purposeful use of the hands with stereotypic hand movement, and seizures. Initially RS was considered to be very rare; however, recent reports suggest that the prevalence is considerably higher and occurrence is world-wide. Because the pathophysiological process remains unknown, the diagnosis of RS is based mainly on its characteristic clinical features and course. We experienced two cases of RS which, to our knowledge, are the first reported in Korea. It is quite possible that many patients with RS not yet being diagnosed in Korea. 相似文献
66.
Extramarital sex and HIV risk behavior among US adults: results from the National AIDS Behavioral Survey. 总被引:4,自引:4,他引:0
下载免费PDF全文
![点击此处可从《American journal of public health》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Data from the National AIDS Behavioral Survey were used to examine the social distribution of extramarital sex and risk for human immunodeficiency virus (HIV) infection among married individuals in the United States. Of 1686 married respondents living across the United States, 2.2% reported extramarital sex; of 3827 married respondents living in 23 urban areas with large Hispanic or African-American populations, 2.5% reported having sexual partners outside marriage. The data indicate that the correlates of extramarital sex varied by race/ethnicity. Low levels of condom use were found among people reporting extramarital sex (8% to 19% consistent users). 相似文献
67.
C van Kerckhove L Luyrink J Taylor H Melin-Aldana K Balakrishnan W Maksymowych M Elma D Lovell E Choi D N Glass 《The Journal of rheumatology》1991,18(6):874-879
To further investigate a clinical impression that patients with early onset pauciarticular juvenile rheumatoid arthritis (EOPA-JRA) who carry HLA-DQw1 have more severe arthritis, we subtyped HLA-DQw1 in American midwestern patients with EOPA-JRA. The HLA-DQA1*0101 subtype was present in 10 of 19 patients who developed persistent polyarticular erosive disease compared with 18 of 92 healthy controls (chi 2 = 9.13, p = 0.003, RR = 4.6), and occurred more frequently in this polyarticular group than in patients without polyarticular erosive disease (chi 2 = 4.11, p = 0.040, RR = 3.0). The presence of HLA-DQA1*0101 was significantly lower in patients with chronic iridocyclitis than in patients without chronic iridocyclitis (chi 2 = 7.07, p = 0.008, RR = 0.21). In HLA-DQA1*0101 positive patients, DNA sequences of the beta-1 domain of the HLA-DQ alpha and HLA-DQ beta genes (HLA-DQA1*0101, HLA-DQB1*0501 and HLA-DQB1*0503) were identical to those in controls. In this midwestern EOPA-JRA population, HLA-DQA1*0101 or genes in linkage disequilibrium with it, are associated with a cohort of patients with EOPA-JRA with distinct clinical characteristics. 相似文献
68.
Seong-Woong Kim Kyu-Won Shim Nick Plesnila Yong-Oock Kim Joong-Uhn Choi Dong-Seok Kim 《Child's nervous system》2007,23(2):201-206
Objects We designed several distraction devices and applied these instruments in 14 patients with varying types of craniosynostosis.
The aim of this report is to clarify the advantages and disadvantages of these surgical methods and to discuss current concepts
for the surgical strategy in the treatment of craniosynostosis.
Methods From January 2000 to July 2005, 28 patients with craniosynostosis were retrospectively analyzed. Surgical treatment was performed
on 14 patients using the distraction method with internal distraction devices that we designed, in which 5 patients had plagiocephaly,
3 brachycephaly, and 6 scaphocephaly. All patients underwent preoperative and postoperative evaluations, which included the
patient’s neurological state, and three-dimensional CT.
Results With distraction devices, the time required for the surgery could be shortened almost 3 1/3 h; the bleeding during the surgery
was decreased with reduced requirement of more than 200 ml of blood transfusion as compared with remodeling surgery. Postoperatively
achieved distraction distances varied from 30.0 to 47.5 mm (mean, 42.99 mm). The average increased volume percent of cranium
in distraction surgery group was 20.9% (range, −11.5 to 58.9%) after full distraction.
Conclusion With distraction surgery, satisfactory cranial volume expansion and aesthetically pleasing morphological states were achieved
in all cases, and the efficacy was statistically significantly high as compared with remodeling method. 相似文献
69.
YoungSoon Yang Jung Eun Kim Jung Seok Lee SangYun Kim 《JOURNAL OF CLINICAL NEUROLOGY》2007,3(4):192-196
A 42-year-old man with left posterior inferior cerebellar artery (PICA) infarction presented with akinetic mutism and cognitive impairment. Initially he suffered from akinetic mutism and MRI-documented infarction in the distribution of the left PICA. Twelve days later he developed cognitive impairment. Neuropsychological tests were performed, with the results corrected for age and education being compared with published Korean norms. Impaired performances were evident on executive function testing, with difficulties in planning, abstract reasoning, set-shifting, and perseveration. Akinetic mutism and cognitive-affective syndrome may be a manifestation of unilateral PICA infarction. 相似文献
70.
Eun Yeon Joo Jee Hyun Kim Woo Suk Tae Sun Jung Han Seunghwan Kim Myoung-Hee Kim Hong Sik Byun Seung Bong Hong 《Journal of neuroimaging》2004,14(4):365-368
A patient with chronic cerebral paragonimiasis began to have new motor seizures of the right face manifested by clonic contractions that occurred several hundred times a day, consistent with simple partial status epilepticus. Ictal electroencephalogram discharges started from the left frontal region and then spread to the left hemisphere with left frontal maximum. But clinical seizures were limited to the right face. The frequent partial seizures were controlled by the intravenous infusion of phenytoin. Brain magnetic resonance imaging showed multiple conglomerated round nodules with encephalomalacia in the left temporal and occipital lobes. Applying the technique of ictal-interictal single-photo emission computed tomography subtraction, the authors were able to localize the focal ictal-hyperperfusion on left precentral cortex adjacent to the lesions that correspond to the anatomical distribution of left face motor area. 相似文献