全文获取类型
收费全文 | 32688篇 |
免费 | 2441篇 |
国内免费 | 64篇 |
专业分类
耳鼻咽喉 | 201篇 |
儿科学 | 1134篇 |
妇产科学 | 1055篇 |
基础医学 | 4409篇 |
口腔科学 | 632篇 |
临床医学 | 4853篇 |
内科学 | 6175篇 |
皮肤病学 | 330篇 |
神经病学 | 3027篇 |
特种医学 | 716篇 |
外科学 | 3360篇 |
综合类 | 629篇 |
一般理论 | 42篇 |
预防医学 | 4307篇 |
眼科学 | 290篇 |
药学 | 1982篇 |
中国医学 | 21篇 |
肿瘤学 | 2030篇 |
出版年
2023年 | 152篇 |
2022年 | 219篇 |
2021年 | 509篇 |
2020年 | 319篇 |
2019年 | 562篇 |
2018年 | 604篇 |
2017年 | 447篇 |
2016年 | 526篇 |
2015年 | 611篇 |
2014年 | 860篇 |
2013年 | 1367篇 |
2012年 | 1986篇 |
2011年 | 2007篇 |
2010年 | 1085篇 |
2009年 | 1062篇 |
2008年 | 1873篇 |
2007年 | 1923篇 |
2006年 | 1857篇 |
2005年 | 1867篇 |
2004年 | 1788篇 |
2003年 | 1725篇 |
2002年 | 1678篇 |
2001年 | 555篇 |
2000年 | 626篇 |
1999年 | 599篇 |
1998年 | 398篇 |
1997年 | 352篇 |
1996年 | 339篇 |
1995年 | 344篇 |
1994年 | 297篇 |
1993年 | 290篇 |
1992年 | 451篇 |
1991年 | 434篇 |
1990年 | 447篇 |
1989年 | 397篇 |
1988年 | 361篇 |
1987年 | 359篇 |
1986年 | 311篇 |
1985年 | 326篇 |
1984年 | 287篇 |
1983年 | 226篇 |
1982年 | 212篇 |
1981年 | 189篇 |
1980年 | 198篇 |
1979年 | 210篇 |
1978年 | 190篇 |
1977年 | 144篇 |
1976年 | 149篇 |
1974年 | 162篇 |
1973年 | 143篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
D. S. H. Bell 《Diabetologia》2007,50(3):695
82.
83.
84.
85.
Susan Bell 《The Journal of neuroscience nursing》2004,36(4):195-199
Germinomas are the most common type of germ cell tumor occurring commonly before the second decade of life. Because of the radiosensitivity of germinomas, traditional treatment following diagnosis has been conventional radiotherapy. The desire to defer radiotherapy to avoid the delayed neurocognitive effects has led researchers to investigate the use of up front chemotherapy. A major limitation in using chemotherapy for brain tumors has been the inability to deliver drugs across the blood brain barrier. The blood brain barrier consortium has developed chemotherapy protocols for patients with malignant brain tumors through the use of reversible osmotic opening of the blood brain barrier. While the patient is under general anesthesia, osmotic opening or disruption is achieved by a 30-second intracarotid infusion of mannitol. The mannitol infusion is followed by both intraarterial and intravenous chemotherapy. By administering chemotherapy in conjunction with blood brain barrier disruption, drug delivery to the tumor and the brain around tumor is increased. 相似文献
86.
87.
Diana Bell Yi-Jue Zhao Pulivarthi H. Rao Randal S. Weber Adel K. El-Naggar 《Head and neck pathology》2007,1(2):165-168
We present an adenoid cystic carcinoma of the base of tongue in a 48-year-old male with a restricted chromosomal alteration
by cytogenetic and spectral karyotypic analysis (SKY). SKY and G-banding analyses identified the t(6;14)(q25;q13) as the sole
structural aberration in all metaphases analyzed. This finding supports a critical role for this event in the development
of this tumor. The implications of chromosome 6q translocation in this case and in previously reported adenoid cystic carcinomas
are highlighted and discussed. 相似文献
88.
Background: The Farnsworth D15 test is designed to categorise colour vision deficiency as severe or moderate. The level of difficulty of the test was set so that those who passed it should be able to recognise surface colour codes, such as those used for electrical wiring. The test is widely used to provide advice to patients with abnormal colour vision and is often used for occupational selection when reliable recognition of surface colour codes is required. However, there has been only one previous study of the correlation between performance at the D15 test and the naming of surface colour codes and there has been no study of whether a person who passes the D15 can reliably name surface colours. Methods: One hundred and two people aged 11 to 65 years with abnormal colour vision were recruited from consecutively presenting optometric patients and were asked to name the colours of fabric, paint and cotton thread samples. There were 10 colours in each class of material and the samples were presented in a large (five to 10 degree angular subtense) and small size (2.5 deg and a single thread). The errors made were compared to those made by an age‐matched control group of equal size with normal colour vision. Results: The correlations between the Farnsworth D15 colour confusion index and colour naming errors were 0.62 for the large stimuli and 0.73 for the small stimuli. Its sensitivity and specificity identifymg those who made more errors than the worst performing colour normal person were 0.80 and 0.69 (large stimuli) and 0.75 and 0.71 (small stimuli). A Nagel anomaloscope range of less than 35 scale units provides essentially the same sensitivity and specificity. Conclusions: About 40 per cent of those with abnormal colour vision can name the main colours correctly under good visibility conditions. The D15 test is an imperfect predictor of those who can name surface colour codes correctly but it does provide useful information for general counselling. It is not suitable as a single test for occupational selection because it will pass 20 per cent who cannot name surface colours correctly and fail 30 per cent who can. In occupations in which recognition of surface colour codes is of critical importance, it may be best not to select people with abnormal colour vision because of the lack of a colour vision test that is a perfect predictor of the ability to recognise surface colours. 相似文献
89.
Hugh Devlin Kety Karayianni Anastasia Mitsea Reinhilde Jacobs Christina Lindh Paul van der Stelt Elizabeth Marjanovic Judith Adams Susan Pavitt Keith Horner 《Oral surgery, oral medicine, oral pathology, oral radiology, and endodontics》2007,104(6):821-828
OBJECTIVES: Measurement of cortical thickness and subjective assessment of cortical porosity on panoramic radiographs are methods previously reported for diagnosing osteoporosis. The aims of this study were to determine the relative efficacy of the mandibular cortical index and cortical width in detecting osteoporosis, both alone and in combination, and to determine the optimal cortical width threshold for referral for additional osteoporosis investigation. STUDY DESIGN: Six hundred seventy-one postmenopausal women 45 to 70 years of age were recruited for this study. They received dual energy x-ray absorptiometry (DXA) scans of the left hip and lumbar spine (L1 to L4), and dental panoramic radiographic examinations of the teeth and jaws. Three observers separately assessed the mandibular cortical width and porosity in the mental foramen region of the mandible. Cortical width was corrected for magnification errors. Chi-squared automatic interaction detection analysis (CHAID) software was used (SPSS AnswerTree, version 3.1, SPSS Inc., Chicago, IL). RESULTS: Chi-squared automatic interaction detection analysis showed that the cortical porosity was a poorer predictor of osteoporosis than mandibular cortical width. For the 3 observers, a mandibular cortical width of <3 mm provided diagnostic odds ratios of 6.51, 6.09, and 8.04. The test is therefore only recommended in triage screening of individuals by using radiographs made for purposes other than osteoporosis. CONCLUSION: When evaluating panoramic radiographs, only those patients with the thinnest mandibular cortices (i.e., <3 mm) should be referred for further osteoporosis investigation. 相似文献