首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   296062篇
  免费   17219篇
  国内免费   414篇
耳鼻咽喉   4205篇
儿科学   10283篇
妇产科学   10243篇
基础医学   44943篇
口腔科学   7496篇
临床医学   24146篇
内科学   55747篇
皮肤病学   6309篇
神经病学   20998篇
特种医学   11610篇
外国民族医学   43篇
外科学   46650篇
综合类   7765篇
现状与发展   1篇
一般理论   160篇
预防医学   19893篇
眼科学   6943篇
药学   20865篇
中国医学   787篇
肿瘤学   14608篇
  2018年   3611篇
  2017年   2650篇
  2016年   3069篇
  2015年   3486篇
  2014年   4569篇
  2013年   7203篇
  2012年   9051篇
  2011年   9435篇
  2010年   6119篇
  2009年   5541篇
  2008年   8659篇
  2007年   9507篇
  2006年   9348篇
  2005年   8944篇
  2004年   8654篇
  2003年   8157篇
  2002年   7753篇
  2001年   13318篇
  2000年   13646篇
  1999年   11415篇
  1998年   3022篇
  1997年   2788篇
  1996年   2633篇
  1995年   2544篇
  1994年   2342篇
  1992年   8312篇
  1991年   8449篇
  1990年   8259篇
  1989年   8075篇
  1988年   7313篇
  1987年   7071篇
  1986年   6719篇
  1985年   6514篇
  1984年   4760篇
  1983年   4118篇
  1982年   2469篇
  1979年   4427篇
  1978年   3228篇
  1977年   2731篇
  1976年   2503篇
  1975年   2833篇
  1974年   3352篇
  1973年   3362篇
  1972年   3118篇
  1971年   2948篇
  1970年   2838篇
  1969年   2581篇
  1968年   2538篇
  1967年   2373篇
  1966年   2264篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
161.
BACKGROUND: The present study investigated the use of acupuncture analgesia in maxillofacial surgery. PATIENTS AND METHODS: Acupuncture analgesia was applied in 120 patients. In 20 of these, surgery was carried out under general anaesthesia in combination with acupuncture analgesia. In 100 patients, acupuncture analgesia was applied in addition to traditional postoperative analgesia. In case of troublesome postoperative pain, it was necessary to carry out additional sessions (1-4) of acupuncture stimulation. RESULTS: When acupuncture analgesia was used, the pulse rate and blood pressure during surgery generally remained stable. In the present study serum cortisol was also measured and showed only minor elevation. DISCUSSION: The present study demonstrated favourable results when the first variant of the brake method of acupoint stimulation was used for 40-50 min with additional manual twirling of the needles. This involved inserting needles into the acupoints and, using slow, rolling manual movements increasing the amplitude step-by-step provoking simultaneous especially strong patient sensations. CONCLUSION: Acupuncture analgesia can be a useful adjunct to conventional anaesthesia in maxillofacial surgery.  相似文献   
162.
D J Harris  G O Waring  L L Burk 《Ophthalmology》1989,96(11):1597-1607
After penetrating keratoplasty in 52 eyes, keratography refraction and keratometry were used to select appropriate interrupted sutures for removal in order to reduce astigmatism. All eyes had one continuous and either 12 or 16 interrupted nylon sutures. The keratographs were examined retrospectively and separated into six groups on the basis of similar mire patterns. The removal of single sutures associated with three of these patterns reduced astigmatism by the following average amounts: symmetrical oval pattern, 0.44 diopters (D); D-shaped oval pattern, 2.07 D; and focal indentation pattern, 6.60 D. The other three patterns--mildly disrupted mires, incomplete mires, and uninterpretable mires--did not allow quantification of results. Examples of these keratographic patterns are presented and recommendations are made for their use in the management of astigmatism following penetrating keratoplasty.  相似文献   
163.
In a series of 75 spines studied at autopsy, the authors found 21 (28%) affected by ankylosing hyperostosis. The 21 cases included three in the cervical spine, 12 in the thoracic spine, and five in the lumbar spine. One case had both thoracic and lumbar spine disease. The average age was 65 years (range, 50-90 years). The mean weight was 85 kg, which was 20 kg more than the mean weight of the nonaffected subjects. Four cases had adult onset diabetes mellitus. No other endocrine or arthritic disease was noted either clinically or at autopsy. No abnormalities of calcium or phosphorus metabolism were found. The cause of death was unrelated to their spine disease, and clinical records were devoid of any major complaints referable to the spine.  相似文献   
164.
The value of maternal C-reactive protein (CRP) levels as predictors of fetal and maternal infective morbidity and fetal mortality was assessed prospectively over a 6-month period in all cases of premature rupture of the fetal membranes or suspected premature labour. Statistical analysis of results showed that CRP at a level of 1.32 mg/dl is a sensitive marker of infective morbidity in mother and neonate. Furthermore, there was a significant association between raised CRP levels and low-birth-weight babies, suggesting that intra-uterine infection is a major cause of prematurity in the study population.  相似文献   
165.
A questionnaire survey of career choices was carried out among 112 medical graduates, after one year's internship (group I), during their National Youth Corps programme in Kaduna, Lagos, Cross River and Oyo states of Nigeria, and 365 final-year medical undergraduates (group 2) in the colleges of medicine in the corresponding states. A total of 13% in group I and 40% in group 2 were undecided as regards their first choice. Obstetrics and gynaecology was the most popular first choice in both groups. General practice ranked fifth among group I, but displaced surgery to rank second among group 2. The differences were statistically significant. A total of 41% of group I and 46% of group 2 preferred to work in a teaching hospital, reflecting the high preference for surgical specialties. Twenty-six per cent and 33.7% of respondents in groups 1 and 2 respectively wished to own their own practice or work in the private sector. General practice is a new specialty and its growth is supported by a national postgraduate training programme. A shift towards general practice is seen compared with previous studies of career preference among Nigerian medical graduates and students. This may be due to a changing balance of supply and demand in the medical work-force, or a better assessment of the nation's health problems and manpower needs.  相似文献   
166.
In general, defects in phagocytosis and in humoral or cellular immunity do not appear to predispose to the acquisition of UTI but do influence the clinical manifestations and the severity, microbiology, and complications of infection once it is established. The incidence of UTI in immunosuppressed patients other than diabetics or renal transplant recipients is not higher than the incidence in nonimmunosuppressed individuals. The higher frequencies of infection seen in diabetics and in renal transplant recipients correlate best with the duration of bladder instrumentation rather than with glycosuria or immunosuppressive regimen. Neutropenia blunts the clinical manifestations of UTI and predisposes to bacteremia. Use of broad spectrum antibiotics results in alterations in indigenous flora, promotes urinary infections with resistant nosocomial pathogens, and predisposes to fungemia with hematogenous seeding of the urinary tract. Routine screening for detection of asymptomatic bacteriuria and prompt institution of antimicrobial therapy is indicated only in renal transplant recipients within 3 months of their surgery and not in any of the other diseases discussed.  相似文献   
167.
168.
169.
The influence of chronic administration of a dry cleared extract of Glycyrrhiza glabra (DCEG) containing flavonoids on the behavioral status and learning of intact and ovariectomized adult female rats has been studied. The DCEG preparation was administered in low (0.5 mg/kg, i.p.) and high (5.0 mg/kg, i.p.) daily doses over a period of 14 days and the results were evaluated on the passive avoidance situation model and in the open field test. It was established that the chronic administration of DCEG in both low and high doses produced correction of the passive avoidance performance in ovariectomized female rats. The administration of DCEG in a low dose also positively influenced the structure of purposeful behavior of females with deficiency of estrogens. __________ Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 39, No. 8, pp. 27 – 29, August, 2005.  相似文献   
170.
We tested the hypothesis that innate immune signaling in utero could disrupt the structural development of the fetal lung, contributing to the pathogenesis of bronchopulmonary dysplasia. Injection of Escherichia coli lipopolysaccharide (LPS) into the amniotic fluid of E15 BALB/cJ mice increased the luminal volume density of fetal mouse lungs at embryonic day (E) 17 and E18. LPS also increased luminal volume and decreased distal lung branching in fetal mouse lung explants. This effect required NF-kappaB activation and functional Toll-Like Receptor 4. Airway branching may require fibronectin-dependent epithelial-mesenchymal interactions, representing a potential target for innate immune signaling. Anti-fibronectin antibodies and LPS both blocked distal lung branching. By immunofluorescence, fibronectin localized to the clefts between newly formed airways but was restricted to peripheral mesenchymal cells in LPS-exposed explants. These data suggest that LPS may alter the expression pattern of mesenchymal fibronectin, potentially disrupting epithelial-mesenchymal interactions and inhibiting distal airway branching and alveolarization. This mechanism may link innate immune signaling with defects in structural development of the fetal lung.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号