全文获取类型
收费全文 | 5806篇 |
免费 | 660篇 |
国内免费 | 169篇 |
专业分类
耳鼻咽喉 | 59篇 |
儿科学 | 224篇 |
妇产科学 | 138篇 |
基础医学 | 146篇 |
口腔科学 | 105篇 |
临床医学 | 1283篇 |
内科学 | 1266篇 |
皮肤病学 | 163篇 |
神经病学 | 348篇 |
特种医学 | 200篇 |
外科学 | 1673篇 |
综合类 | 16篇 |
一般理论 | 1篇 |
预防医学 | 345篇 |
眼科学 | 330篇 |
药学 | 123篇 |
肿瘤学 | 215篇 |
出版年
2023年 | 112篇 |
2021年 | 61篇 |
2020年 | 96篇 |
2019年 | 42篇 |
2018年 | 130篇 |
2017年 | 174篇 |
2016年 | 190篇 |
2015年 | 141篇 |
2014年 | 229篇 |
2013年 | 309篇 |
2012年 | 103篇 |
2011年 | 123篇 |
2010年 | 239篇 |
2009年 | 339篇 |
2008年 | 129篇 |
2007年 | 78篇 |
2006年 | 137篇 |
2005年 | 93篇 |
2004年 | 52篇 |
2003年 | 69篇 |
2002年 | 55篇 |
2001年 | 122篇 |
2000年 | 90篇 |
1999年 | 139篇 |
1998年 | 180篇 |
1997年 | 208篇 |
1996年 | 312篇 |
1995年 | 258篇 |
1994年 | 198篇 |
1993年 | 122篇 |
1992年 | 136篇 |
1991年 | 138篇 |
1990年 | 71篇 |
1989年 | 135篇 |
1988年 | 113篇 |
1987年 | 88篇 |
1986年 | 110篇 |
1985年 | 89篇 |
1984年 | 99篇 |
1983年 | 88篇 |
1982年 | 76篇 |
1981年 | 63篇 |
1980年 | 83篇 |
1979年 | 45篇 |
1978年 | 63篇 |
1977年 | 43篇 |
1976年 | 49篇 |
1975年 | 47篇 |
1964年 | 49篇 |
1963年 | 47篇 |
排序方式: 共有6635条查询结果,搜索用时 17 毫秒
1.
2.
Prevalence of vitamin D depletion among morbidly obese patients seeking gastric bypass surgery 总被引:5,自引:0,他引:5
Arthur M. Carlin M.D. D. Sudhaker Rao MB B.S. F.A.C.P. F.A.C.E. Ali M. Meslemani M.D. Jeffrey A. Genaw M.D. Nayana J. Parikh Shiri Levy M.D. Arti Bhan M.D. Gary B. Talpos M.D. 《Surgery for obesity and related diseases》2006,2(2):696-103
BACKGROUND: Abnormalities in calcium and vitamin D metabolism have been reported after bariatric surgery. The purpose of this study was to evaluate vitamin D nutritional status among morbidly obese patients before gastric bypass surgery. METHODS: We prospectively studied 279 morbidly obese patients seeking gastric bypass surgery for vitamin D nutritional status as assessed by serum 25-hydroxyvitamin D level. In addition, serum samples were analyzed for calcium, alkaline phosphatase (AP), intact parathyroid hormone (PTH), and 1,25-dihydroxyvitamin D. RESULTS: Mean patient age was 43 +/- 9 years; 87% of the study patients were women, and 72% were white. Serum calcium and AP levels were normal in 88% and 89% of the patients, respectively. Vitamin D depletion, defined as serum 25-hydroxyvitamin D level 相似文献
3.
4.
Why is the age-standardized incidence of low-trauma fractures rising in many elderly populations? 总被引:4,自引:0,他引:4
Pekka Kannus Seppo Niemi Jari Parkkari Mika Palvanen Ari Heinonen Harri Siev?nen Teppo J?rvinen Karim Khan Markku J?rvinen 《Journal of bone and mineral research》2002,17(8):1363-1367
Low-trauma fractures of elderly people are a major public health burden worldwide, and as the number and mean age of older adults in the population continue to increase, the number of fractures is also likely to increase. Epidemiologically, however, an additional concern is that, for unknown reasons, the age-standardized incidence (average individual risk) of fracture has also risen in many populations during the recent decades. Possible reasons for this rise include a birth cohort effect, deterioration in the average bone strength by time, and increased average risk of (serious) falls. Literature provides evidence that the rise is not due to a birth cohort effect, whereas no study shows whether bone fragility has increased during this relatively short period of time. This osteoporosis hypothesis could, however, be tested if researchers would now repeat the population measurements of bone mass and density that were made in the late 1980s and the 1990s. If such studies proved that women's and men's age-standardized mean values of bone mass and density have declined over time, the osteoporosis hypothesis would receive scientific support. The third explanation is based on the hypothesis that the number and/or severity of falls has risen in elderly populations during the recent decades. Although no study has directly tested this hypothesis, a great deal of indirect epidemiologic evidence supports this contention. For example, the age-standardized incidence of fall-induced severe head injuries, bruises and contusions, and joint distortions and dislocations has increased among elderly people similarly to the low-trauma fractures. The fall hypothesis could also be tested in the coming years because the 1990s saw many research teams reporting age- and sex-specific incidences of falling for elderly populations, and the same could be done now to provide data comparing the current incidence rates of falls with the earlier ones. 相似文献
5.
6.
LESLEY BOULTON MB CHB FRACO DO Ophthalmologist 《Clinical & experimental ophthalmology》1986,14(4):365-371
The Low Vision Clinic at the Palmerston North Hospital has now been oerating for 70 years. Over the course of these ten years a number of factors have emerged which can be as readily applied to general ophthalmological practice as to low vision practice. The philosophy of low vision care is one of which all ophthalmologists should be aware and includes factors to be taken into account when dealing with children, people in the workplace, and everyday factors involved in daily living activities, all of which are equally relevant in routine ophthalmological practice. This paper endeavours to share some thoughts on these factors and also discusses means by which the visually handicapped can be helped in areas where specialist low vision services are not readily available. 相似文献
7.
Comparison of trichloroethylene and enflurane as adjuncts to nitrous oxide and relaxant anaesthesia 总被引:1,自引:0,他引:1
Forty women who underwent gynaecological surgery were randomly allocated to receive trichloroethylene, enflurane, or enflurane plus fentanyl as adjuncts to nitrous oxide/relaxant anaesthesia with controlled ventilation. No serious cardiac dysrhythmias were seen in any group. Each patient was observed postoperatively for 4 hours by a nurse blind to the technique used, and questioned at 24 hours by a similarly blinded anaesthetist. Recovery after trichloroethylene was not significantly prolonged although postoperative analgesia by visual analogue was better, opiate analgesia was required less frequently and there was less nausea and vomiting than in either of the enflurane groups. We argue for the continued use of trichloroethylene by this technique, because it costs one hundred times less than enflurane and because of the potential morbidity of the postoperative opiate dosage required after enflurane. 相似文献
8.
E.Paul Kirk MB BS J. Santa MD T. Heckler MBA M. Collins MD 《American journal of obstetrics and gynecology》1998,178(6):1222-1228
OBJECTIVE: Our purpose was to assess whether legislative action influenced the role of obstetrician-gynecologists as primary care physicians. STUDY DESIGN: An observational study was performed on the basis of a questionnaire sent to 410 obstetrician-gynecologists and 27 medical directors of managed-care organizations. RESULTS: Of 67% of obstetrician-gynecologists and 96% of medical directors who responded, there was agreement as to the content of primary care, but a minority (38%) of obstetrician-gynecologists identified themselves as primary care providers. A minority of medical directors (35%) felt that obstetrician-gynecologists should serve in that role. Both obstetrician-gynecologists and medical directors felt that legislation had little impact. CONCLUSION: The reticence of obstetrician-gynecologists to assume a major role in primary care appears to be the result of an uneasiness with accepting a more comprehensive role in patient management and gatekeeping. They appear comfortable with the more traditional roles but feel that training and experience has not prepared them well for the management of more complex medical problems. (Am J Obstet Gynecol 1998;178:1222-8.) 相似文献
9.
10.
Patients'attitudes to rectal drug administration 总被引:2,自引:0,他引:2
One hundred adult patients attending for day case surgery were surveyed by anonymous questionnaire in order to determine their attitudes to rectal drug administration. Fifty four patients did not want an analgesic drug (diclofenac sodium) administered rectally whilst under anaesthesia, all preferring to take it orally if available. Ninety eight patients thought that drugs administered per rectum should always be discussed with them beforehand and a few had very strong feelings about this route of administration. We suggest that prescribers of rectal diclofenac should always discuss it with patients pre-operatively. Whilst many are happy to have suppositories, some young patients are sensitive about this and prefer to take such medication by mouth. 相似文献