全文获取类型
收费全文 | 14027篇 |
免费 | 705篇 |
国内免费 | 101篇 |
专业分类
耳鼻咽喉 | 95篇 |
儿科学 | 353篇 |
妇产科学 | 92篇 |
基础医学 | 1730篇 |
口腔科学 | 384篇 |
临床医学 | 795篇 |
内科学 | 3699篇 |
皮肤病学 | 549篇 |
神经病学 | 943篇 |
特种医学 | 600篇 |
外科学 | 2364篇 |
综合类 | 50篇 |
预防医学 | 458篇 |
眼科学 | 276篇 |
药学 | 1123篇 |
中国医学 | 24篇 |
肿瘤学 | 1298篇 |
出版年
2023年 | 76篇 |
2022年 | 130篇 |
2021年 | 265篇 |
2020年 | 157篇 |
2019年 | 210篇 |
2018年 | 283篇 |
2017年 | 215篇 |
2016年 | 234篇 |
2015年 | 245篇 |
2014年 | 332篇 |
2013年 | 448篇 |
2012年 | 682篇 |
2011年 | 751篇 |
2010年 | 448篇 |
2009年 | 376篇 |
2008年 | 684篇 |
2007年 | 760篇 |
2006年 | 720篇 |
2005年 | 828篇 |
2004年 | 802篇 |
2003年 | 822篇 |
2002年 | 848篇 |
2001年 | 353篇 |
2000年 | 393篇 |
1999年 | 375篇 |
1998年 | 197篇 |
1997年 | 155篇 |
1996年 | 173篇 |
1995年 | 132篇 |
1994年 | 126篇 |
1993年 | 104篇 |
1992年 | 232篇 |
1991年 | 194篇 |
1990年 | 208篇 |
1989年 | 192篇 |
1988年 | 182篇 |
1987年 | 170篇 |
1986年 | 150篇 |
1985年 | 146篇 |
1984年 | 126篇 |
1983年 | 102篇 |
1982年 | 48篇 |
1981年 | 61篇 |
1979年 | 71篇 |
1978年 | 63篇 |
1977年 | 54篇 |
1973年 | 55篇 |
1971年 | 44篇 |
1969年 | 54篇 |
1968年 | 52篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
71.
Takeshi Miyairi Shinichi Takamoto Yutaka Kotsuka Atsuko Takeuchi Katsuo Yamanaka Hajime Sato 《European journal of cardio-thoracic surgery》2005,28(1):97-101; discussion 102-3
OBJECTIVE: Retrograde cerebral perfusion (RCP) is used as an adjunctive method to hypothermic circulatory arrest to enhance cerebral protection in patients undergoing thoracic aortic surgery. It remains unclear whether RCP provides improved neurological and neuropsychological outcome. METHODS: Forty-six patients undergoing thoracic aortic surgery using RCP, and 28 undergoing coronary artery bypass grafting (CABG; n = 28) with CPB, were enrolled in the study. Patients receiving RCP were subdivided into two groups, those with less than 60 min of RCP (S-RCP; n = 27) and with 60 min or more (L-RCP; n = 19). The patients' neurocognitive state was assessed by the revised Wechsler Adult Intelligence Scale a few days before operation, at 2-3 weeks and 4-6 months after operation. RESULTS: There were no stroke, seizure, and hospital mortality in either group. Significant decline between baseline and early scores were seen in three subtests (digit span, arithmetic, and picture completion) for S-RCP and four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP. Significant decline between baseline and late scores were seen in one subtest (arithmetic) for S-RCP, four (digit span, arithmetic, picture completion, and picture arrangement) for L-RCP, and one (object assembly) for CABG. The mean change of scores for one late test (digit symbol) was significantly lower in S-RCP than in CABG. The mean change of scores for three early tests (digit span, vocabulary, and picture arrangement) and four late tests (information, digit span, picture completion, and picture arrangement) were significantly lower in L-RCP than in CABG. Stepwise logistic regression analysis disclosed that, after considering the other variables, significant difference in test score changes were observed between CABG and L-RCP for two early tests (picture completion and digit symbol) as well as for three late tests (digit span, similarities, and picture completion). None of test score changes showed significant difference between CABG and S-RCP. CONCLUSIONS: The neurocognitive outcome in patients undergoing RCP less than 60 min were comparable with patients undergoing CABG without circulatory arrest. Prolonged RCP of 60 min or more in patients undergoing surgery of the thoracic aorta was associated with postoperative neurocognitive impairment. 相似文献
72.
Hiroyuki Sakai Masaki Ibe Hidetoshi Takahashi Shinobu Matsuo Kensaku Okamoto Isao Makino Yukio Oomori Hajime Iizuka 《The Journal of dermatology》1996,23(1):42-46
Langerhans cell histiocytosis is currently regarded as a reactive proliferative process of Langerhans cells rather than a malignancy. The disease is characterized by Langerhans cell infiltration of skin, lung, bone and other organs. We report a 74-year-old man with Langerhans cell histiocytosis who had generalized hemorrhagic and crusted papules. He also had diabetes insipidus. Because he did not have any severe constitutional symptoms or failure of vital organs, we applied topical PUVA treatment to his skin lesions, which responded well to the therapy. Diabetes insipidus, however, remained, in spite of X ray radiotherapy for the pituiary lesion. 相似文献
73.
Dr. Hajime Kuwayama MD 《Digestive diseases and sciences》1996,41(5):979-983
Sucralfate accelerates the healing of chronic gastric ulcers, but its mechanism is not well understood. We studied the effect of long-term administration of sucralfate on gastric epithelial proliferation in the rat by means of tritiated thymidine autoradiography. Rats were treated perorally with 500 mg/kg sucralfate once a day. After 28 days, rats were injected with tritiated thymidine 1µCi/g body weight and sacrificed 1 hr later. Autoradiographs from antral and fundic mucosae were prepared and a number of proliferative measurements were made. Long-term sucralfate administration produced an increase in tritiated thymidine labeling of epithelial cells and expansion of the proliferative zone in antral mucosa. These results indicate that long-term sucralfate ingestion stimulates gastric antral epithelial proliferation in the rat. In light of the fact that chronic gastric ulcers are usually located in the antral region in humans, this enhanced epithelial proliferation may contribute to the beneficial effect of sucralfate in accelerating the healing of gastric ulcers. 相似文献
74.
Hajime Kazamatsuri M.D. Tetsuya Hirose M.D. Osamu Kanno M.D. Nobumasa Kato M.D. Hiromoto Yasuda 《Psychiatry and clinical neurosciences》1994,48(4):869-879
Abstract: Two autopsied female sibling cases of sudanophilic leukodystrophy are reported. Case A and case B were the second and third of seven siblings, and a sister and a brother died from severe progressive neurological disease with similar symptoms. Consanguineous marriages were noted in the family of both cases through the past three generations. Case A gradually developed intellectual deterioration and tetraplegia at the age of 29, progressed to akinetic mutism within one year and thereafter survived for 14 years. Neuropathologically, a severe atrophy and degeneration were noted in the white matter of the whole cerebrum, sparing the subcortical U-fibers. Myelin and axons were severely damaged with peripheral astrocytic gliosis. Case B developed similar clinical symptoms at the age of 20 and survived for 7 years in the state of akinetic mutism. Similar postmortem findings as those of case A were found in the white matter of the cerebrum with formation of sudanophilic breakdown products and with thick fibrillary gliosis. The pyramidal tract was completely degenerated. There was no accumulation of abnormal lipid in the brains of both cases. 相似文献
75.
76.
Kenji Wakabayashi Kazuo Kawasaki Daizo Yonemura Kiyohiko Yamazaki 《Documenta ophthalmologica. Advances in ophthalmology》1986,63(4):383-388
We previously reported the hyperosmolarity response (a decrease of the ocular standing potential by hyperosmolarity) as a new clinical test of the retinal pigment epithelium (RPE) activity. In the present study a hypertonic solution (Fructmanit, 1.4 × 103 m0sm/1) was intravenously injected for 20 min in proportion to a subject's total blood volume (TBV). At the injection speed of 5, 10, and 15% of the subjects' TBV per hour the mean amplitude of the hyperosmolarity response in normal subjects was 19.7, 30.1 and 36.4% respectively. The amplitude of the hyperosmolarity response depends on the logarithm of the dose of the hypertonic solution within the range of the dose tested.We previously found that hyperosmolarity suppresses the light rise. The present study investigated this suppressive effect in a quantitative manner. The light rise (a full-field illumination of 1.2 × 103 cdl/m2) was dose-dependently suppressed by Fructmanit. The mean of the light rise to dark trough ratio in normal subjects was 1.81 with no osmotic stress, and 1.64, 1.41 and 1.29 respectively at the injection speeds of 5, 10, and 15%. The suppression of the light rise by hyperosmolarity is compatible with the view that the hyperosmolarity response and the light rise share the basal membrane of the RPE as the main site of their generation. 相似文献
77.
A 51-year-old woman, with progressive gait disturbance and dysarthria, had been diagnosed as Menzel-type spinocerebellar degeneration. Later, she developed dystonic posture of upper limbs and bulging eyes. She was diagnosed as Machado-Joseph disease from neurological findings, which consisted of cerebellar signs, pyramidal tract signs and extrapyramidal tract signs and peripheral neuropathy. She died suddenly of unknown origin. Her illness lasted about 13 years. Neuropathological findings showed moderate neuronal loss with gliosis in the subthalamic nucleus, globus pallidus, substantia nigra, dentate nucleus, oculomotor and hypoglossal nucleus and anterior horn. Positron emission tomography (PET) using 15O steady state inhalation technique revealed reduction of cerebral blood flow and cerebral metabolic rate of oxygen in not only cerebellum but also cerebral cortex. These findings are different from typical PET findings of spinocerebellar degeneration. 相似文献
78.
79.
This report describes an experimental model of chronic tonsillar herniation and its effects on the spinal cord. In ten rats, a small piece of chemically induced mammary cancer was transplanted to the supraoccipital bone. In all cases, the transplanted cancers grew into the posterior fossa, destroying the supraoccipital bone and compressing the cerebellum extradurally. In six of the ten rats, tonsillar herniation was observed at 8–14 weeks after transplantation. Transdural infiltration of the tumor cells was not apparent in any animal. In those rats with tonsillar herniation (n=6), the spinal cord from the C5 to the T8 segments showed enlargement of the central canal without exception. Histological examination revealed the following changes: stretching and thinning of the ependymal cells; swelling of the astrocytic processes; and extracellular edema, predominantly in the dorsal gray matter, but also in the ventral inner portion of the dorsal column. In the control group (n=4) and those rats without tonsillar herniation (n=4), such histological changes of the spinal cord were not observed. Although the lesions can not be regarded as representing mature syringomyelia, they most likely constitute an earlier evolutionary stage. 相似文献
80.