全文获取类型
收费全文 | 4913篇 |
免费 | 419篇 |
国内免费 | 8篇 |
专业分类
耳鼻咽喉 | 13篇 |
儿科学 | 155篇 |
妇产科学 | 77篇 |
基础医学 | 589篇 |
口腔科学 | 191篇 |
临床医学 | 549篇 |
内科学 | 1001篇 |
皮肤病学 | 53篇 |
神经病学 | 512篇 |
特种医学 | 195篇 |
外科学 | 428篇 |
综合类 | 141篇 |
一般理论 | 3篇 |
预防医学 | 618篇 |
眼科学 | 72篇 |
药学 | 430篇 |
中国医学 | 1篇 |
肿瘤学 | 312篇 |
出版年
2022年 | 46篇 |
2021年 | 73篇 |
2020年 | 52篇 |
2019年 | 76篇 |
2018年 | 82篇 |
2017年 | 60篇 |
2016年 | 71篇 |
2015年 | 70篇 |
2014年 | 113篇 |
2013年 | 156篇 |
2012年 | 258篇 |
2011年 | 235篇 |
2010年 | 140篇 |
2009年 | 163篇 |
2008年 | 236篇 |
2007年 | 207篇 |
2006年 | 176篇 |
2005年 | 200篇 |
2004年 | 170篇 |
2003年 | 171篇 |
2002年 | 203篇 |
2001年 | 148篇 |
2000年 | 168篇 |
1999年 | 131篇 |
1998年 | 64篇 |
1997年 | 50篇 |
1996年 | 59篇 |
1995年 | 48篇 |
1994年 | 43篇 |
1993年 | 52篇 |
1992年 | 112篇 |
1991年 | 92篇 |
1990年 | 107篇 |
1989年 | 84篇 |
1988年 | 96篇 |
1987年 | 84篇 |
1986年 | 100篇 |
1985年 | 86篇 |
1984年 | 61篇 |
1983年 | 55篇 |
1982年 | 49篇 |
1981年 | 40篇 |
1980年 | 35篇 |
1979年 | 55篇 |
1978年 | 47篇 |
1977年 | 35篇 |
1974年 | 41篇 |
1973年 | 35篇 |
1970年 | 42篇 |
1968年 | 41篇 |
排序方式: 共有5340条查询结果,搜索用时 31 毫秒
81.
Barnett J Thomlinson D Perry C Marshall R MacGowan AP 《The Journal of hospital infection》1999,43(4):309-313
A review of the use of manual handling aids in two hospitals found equipment was employed on a multi-patient basis with inadequate cleaning. Sampling with a Casella slit sampler demonstrated frequent contamination by methicillin-resistant Staphylococcus aureus and Clostridium difficile of fabric aids. Recommendations for care of equipment are made. 相似文献
82.
Repeated injections of a ciliary neurotrophic factor analogue leading to long-term photoreceptor survival in hereditary retinal degeneration 总被引:6,自引:0,他引:6
Chong NH Alexander RA Waters L Barnett KC Bird AC Luthert PJ 《Investigative ophthalmology & visual science》1999,40(6):1298-1305
PURPOSE: To determine whether ciliary neurotrophic factor (CNTF) or brain-derived neurotrophic factor (BDNF) treatment leads to long-term photoreceptor survival in hereditary retinal degeneration. METHODS: An autosomal dominant feline model of rod-cone dystrophy was used throughout the study with two normal animals. In the first experiment, intravitreal injections of a human CNTF analogue (Axokine; Regeneron Pharmaceuticals, Tarrytown, NY) were administered to one eye of each animal (n = 10) beginning on postnatal day 10 and were repeated every 4 weeks. Clinical and histopathologic examinations were performed at 5.5, 9.5, and 13.5 weeks. In the second experiment, animals (n = 17) were randomly assigned to receive intravitreal injections of either Axokine (at half the initial dose), human BDNF, or the vehicle for Axokine to one eye at 5.5 weeks. The same therapy was repeated every 4 weeks in each group. Clinical and histopathologic examinations were performed at 9.5, 13.5, and 17.5 weeks. Photoreceptor survival was assessed by cell counting. Apoptotic cells were identified by morphology and a modified TdT-dUTP terminal nick-end labeling (TUNEL) technique. In the third experiment, two normal animals were treated with Axokine as in the first experiment. Glial fibrillary acidic protein ((GFAP) immunohistochemistry was performed to assess glial cell reaction. RESULTS: In the first two experiments, Axokine significantly prolonged photoreceptor survival (P < 0.01) and reduced the presence of apoptotic cells (P < 0.05) and TUNEL-positive cells (P < 0.05). In the second experiment, results in the the BDNF- and sham-injected eyes were not significantly different from those in the untreated eyes. Minimal posterior subcapsular cataract and mild retinal folds were found in all Axokine-treated eyes in both dystrophic and normal animals. These complications were milder in the second experiment when injections were started later and at a reduced dose. GFAP immunolabeling was also increased in all Axokine-treated eyes. CONCLUSIONS: Axokine, but not BDNF, delays photoreceptor loss in this hereditary retinal degeneration. Repeated injections maintain the protective effect. 相似文献
83.
Marshall ME Wolf M O'Rourke M Barnett TC Crawford ED 《Cancer biotherapy & radiopharmaceuticals》1996,11(2):119-123
Based upon prior data suggesting that alpha-interferon possesses chemomodulatory activity, the Southwest Oncology Group conducted a study in which patients with hormone refractory, metastatic (stage D2) adenocarcinoma of the prostate were treated with 5-fluorouracil (5-FU) and Roferon-A. All patients had bidimensionally measurable disease. Treatment consisted of 5-FU 750 mg/m2/day by continuous i.v. infusion for 5 days with Roferon-A 9 million units subcutaneously ono days 1, 3 and 5. Roferon-A was continued three times weekly throughout treatment. Following a one week hiatus from 5-FU (week 2), 5-FU was continued at a dose of 750 mg/m2 i.v. bolus weekly. Nineteen patients were evaluable for toxicity. The most common toxicities were gastrointestinal and mucosal, hematologic and a flu-like syndrome. There were no deaths related to treatment. Among the 14 patients evaluable for response, the response rate was 0% (95% confidence interval, 0-18%). Thirteen of the 19 evaluable patients have died with a median survival of 9 months. The combination of 5-FU and Roferon-A does not have sufficient activity against advanced, hormone refractory prostate cancer to warrant further investigation. 相似文献
84.
85.
M L Barnett 《The Journal of investigative dermatology》1978,70(3):141-142
Changes in desmosomes were noted in nonacantholytic regions of skin explants cultured in the presence of intercellular antibodies. These changes included dissociation of desmosomes, as well as a "selective loss" of desmosomal components in one or both of neighboring cells. 相似文献
86.
P H Barnett E A Zerhouni R I White S S Siegelman 《AJR. American journal of roentgenology》1980,134(3):439-447
Computed tomography (CT), using a sequential timed scanning technique, was performed on six patients with hepatic cavernous hemangiomas. Initial examination shows a moderately homogeneous circumscribed area with reduced attenuation values. Serial scans after injection of a bolus of contrast material show early peripheral opacification while the central part of the lesion retains low attenuation values for several minutes. Later scans demonstrate a variable degree of "filling in" of the central part of the hemangioma. If the characteristic appearance of this lesion is recognized, confusion with other ominous lesions and biopsy can be avoided. Because of limited experience, the described pattern may not be absolutely pathognomonic for hemangioma, so angiography is currently advised to confirm the diagnosis. 相似文献
87.
Lisa A. Musmanno Robert S. Jamison Richard S. Barnett Edward Buford Jeffrey N. Davidson 《Somatic Cell and Molecular Genetics》1992,18(4):309-318
The mammalianCAD gene codes for a 240-kDa multifunctional protein that catalyzes the first three steps of de novo pyrimidine biosynthesis. Previously, the longest cDNA construct available was missing approximately 500 bp of coding sequence at the 5 end, thereby lacking the sequence to encode the entire carbamylphosphate synthetase (CPSase) domain. Here, a completeCAD hamster cDNA is constructed, placed into a mammalian expression vector, and transfected into hamster cells deficient in CAD. Transfectants show coordinately restored levels of all three enzyme activities and the presence of full-length CAD protein. A derivative construct of theCAD cDNA was generated that should encode only the CPSase domain. When transfected into mammalian cells, a protein was synthesized that had significant CPSase activity both in vivo and in vitro. The two constructs generated in this study will facilitate the study of CAD structure, function, and allosteric regulation. 相似文献
88.
89.
90.
G Barnett C W Chiang M Perez-Reyes S M Owens 《Journal of pharmacokinetics and biopharmaceutics》1982,10(5):495-506
Six subjects each smoked a 1% marijuana cigarette and 2 hr later smoked a second one. Plasma levels of delta-9-tetrahydrocannabinol were measured for 9 hr with a radioimmunoassay. Heart rate and self-reported "high" were measured for 2 hr after each cigarette. All three measures showed a rapid increase after the start of smoking with Cmax occurring before the end of smoking. There was a strong correlation between decrease in heart rate and plasma levels from 10 min after smoking until 120 min. All pharmacodynamic response measures returned to baseline values within approximately 2 hr. 相似文献