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   1278170篇
  免费   92839篇
  国内免费   1988篇
耳鼻咽喉   18205篇
儿科学   42275篇
妇产科学   37824篇
基础医学   187232篇
口腔科学   35394篇
临床医学   108284篇
内科学   251758篇
皮肤病学   26515篇
神经病学   99335篇
特种医学   50161篇
外国民族医学   367篇
外科学   197852篇
综合类   26519篇
现状与发展   1篇
一般理论   301篇
预防医学   92628篇
眼科学   29075篇
药学   97871篇
  1篇
中国医学   2497篇
肿瘤学   68902篇
  2018年   11833篇
  2015年   11640篇
  2014年   16044篇
  2013年   24399篇
  2012年   33601篇
  2011年   36029篇
  2010年   21257篇
  2009年   20051篇
  2008年   35042篇
  2007年   38014篇
  2006年   38582篇
  2005年   37846篇
  2004年   36441篇
  2003年   35424篇
  2002年   34972篇
  2001年   58137篇
  2000年   59634篇
  1999年   50724篇
  1998年   14240篇
  1997年   12825篇
  1996年   13084篇
  1995年   12351篇
  1994年   11765篇
  1993年   10866篇
  1992年   41002篇
  1991年   40373篇
  1990年   39898篇
  1989年   38738篇
  1988年   36137篇
  1987年   35372篇
  1986年   33749篇
  1985年   32156篇
  1984年   23941篇
  1983年   20829篇
  1982年   12385篇
  1981年   10936篇
  1980年   10214篇
  1979年   22649篇
  1978年   15887篇
  1977年   13743篇
  1976年   12986篇
  1975年   14215篇
  1974年   16700篇
  1973年   16096篇
  1972年   15330篇
  1971年   14246篇
  1970年   13231篇
  1969年   12755篇
  1968年   11993篇
  1967年   10492篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
181.
Previous studies of giant axonal neuropathy have reported clinical and pathological findings that indicate involvement of the central nervous system. We studied 3 boys with giant axonal neuropathy, who were 14 to 16 years of age, using auditory, visual, and somatosensory evoked potentials. Absence of waveforms and prolongation of peak and interwave latencies were found. Abnormalities were noted in all modalities. The auditory brainstem evoked response in particular indicated a significant increase in brainstem conduction time. These studies add clinical neurophysiological confirmation of the central nervous system involvement in this disorder and may also provide a means of quantitative evaluation of its progression.  相似文献   
182.
We report a case of vasoactive-agent-induced priapism successfully treated in the emergency department with 10 mg of metaraminol injected into the corpora cavernosa.  相似文献   
183.
184.
The effect of proteases inhibitors, epsilon-amino-caproic acid and gordox, on reproduction of rotavirus SA-11 in MA-104 cells was studied by enzyme immunoassay. These inhibitors were shown to exert an inhibiting effect on rotavirus reproduction.  相似文献   
185.
Haemophilus influenzae vaccine containing polyribosyl ribitol phosphate (PRP) or PRP covalently linked to diphtheria toxoid (PRP-D) was given to 94 healthy infants 17 to 22 months of age at the same time, but not at the same site, as a diphtheria-tetanus-pertussis booster. Systemic reactions were similar in the two vaccine groups and resembled those expected with the diphtheria-tetanus-pertussis injection alone. Six (13%) and seven (14%) of the PRP and PRP-D recipients, respectively, had minor local reactions to the Haemophilus vaccine. Among the 77 children who were not already naturally immune (ie, anti-PRP antibody concentration of less than or equal to 0.15 micrograms of protein per milliliter) before vaccination, PRP-D was significantly more effective than PRP in inducing protective levels of antibody. Only 15 (43%) of the 35 nonimmune PRP recipients achieved a concentration of greater than or equal to 0.15 microgram/mL and only seven (20%) reached a concentration greater than or equal to 1.0 micrograms/mL following vaccination. In contrast, 34 (81%) of the 42 nonimmune recipients of PRP-D had a concentration of greater than or equal to 0.15 microgram/mL following vaccine and 32 (62%) had a concentration of greater than or equal to 1.0 micrograms/mL (P less than or equal to .001). These results suggest that more than one-half of nonimmune 18-month-old infants will not respond to PRP with protective levels of antibody. In light of the current data, recommendation for revaccination at 24 months of age for those immunized at any younger age is appropriate.  相似文献   
186.
In establishing the liability of optometrists for negligence the courts have applied the same standard of care that is imposed upon other health care professionals, holding that optometrists must employ the minimum degree of skill, care and learning that is ordinarily exhibited by members of the profession who are in good standing. The leading cases establishing this standard have involved glaucoma, retinal detachment, and intraocular tumors. Optometrists have also been held liable under product liability law for injuries caused by ophthalmic lenses, which illustrates the trend toward strict liability. Other cases have involved the doctrine of informed consent.  相似文献   
187.
We review evidence suggesting that deaf speakers do not move their articulators toward the following open posture throughout closure and report results from a preliminary cinefluorographic study. Two prelingually deaf and two hearing speakers produced two different strings of alternating heterogeneous monosyllables as though speaking in time with a metronome (the so-called P-center task). Events traditionally associated with vowel production appeared evenly timed throughout the productions, and, in general, the deaf speakers performed similarly to the hearing speakers. We relate the results to Fowler's (1983) interpretation of the P-center phenomenon as an indicant of continuous vowel production.  相似文献   
188.
Biopsies from the diseased bones of patients with familial expansile osteolysis (FEO) were examined by light and electron microscopy. Focal concentrations of multinuclear osteoclasts were present, and these contained viral-like microcylindrical inclusions which appeared exclusive to their nuclei. No consistent relationship was found between osteoclast size and the number of osteoclast nuclei containing microcylindrical inclusions. Quantitative histomorphometry showed evidence of increased bone remodelling with high bone cell densities and a decrease of the reversal period in bone remodelling. The lesions contained prominent woven bone and fibrovascular tissue, together with mononuclear cells and adipocytes. Little bone was found in the most radiolucent lesions, which were almost totally occupied by adipocytes and fibrovascular tissue. Serology did not reveal any significant differences between the viral antibody titres of patients and their age- and sex-matched controls. The present study suggests that intranuclear viral-like microcylindrical inclusions of osteoclasts are not a specific feature of Paget's disease, and are found in other disorders of osteoclast function, including pycnodysostosis, osteopetrosis, giant cell tumours, and familial expansile osteolysis.  相似文献   
189.
190.
Previous studies have shown that stimulation of adrenergic receptors in the brain increases the expression of the immediate early gene (IEG), c-fos, in vivo (Mol. Brain Res., 6(1989) 39-45). The present study was undertaken to determine whether this also holds for other IEGs which have been shown to be activated in brain cell culture by adrenergic agonists. Both yohimbine injection and stressful stimulation, two treatments causing brain norepinephrine (NE) release, were found to cause a parallel, transient activation of at least 5 IEGs (c-fos, nur77, tis-7, zif-268 and tis-21) in the rat cortex. Genes that are not immediate early (beta-actin, NGF and HSP70) were found not to be affected in the interval used (6 h). The responses were mediated predominantly by beta-adrenoceptors with some contribution from alpha 1 receptors. The parallel activation of multiple genes by noradrenergic receptors may enable the coding of different biochemical responses to the activation of different receptors.  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