全文获取类型
收费全文 | 1278383篇 |
免费 | 98208篇 |
国内免费 | 1989篇 |
专业分类
耳鼻咽喉 | 18429篇 |
儿科学 | 44351篇 |
妇产科学 | 35008篇 |
基础医学 | 182170篇 |
口腔科学 | 33585篇 |
临床医学 | 111246篇 |
内科学 | 258260篇 |
皮肤病学 | 28020篇 |
神经病学 | 100358篇 |
特种医学 | 51198篇 |
外国民族医学 | 660篇 |
外科学 | 196404篇 |
综合类 | 27052篇 |
现状与发展 | 1篇 |
一般理论 | 377篇 |
预防医学 | 95714篇 |
眼科学 | 27919篇 |
药学 | 94762篇 |
2篇 | |
中国医学 | 2424篇 |
肿瘤学 | 70640篇 |
出版年
2018年 | 13132篇 |
2017年 | 9963篇 |
2016年 | 10897篇 |
2015年 | 12369篇 |
2014年 | 17163篇 |
2013年 | 26209篇 |
2012年 | 36016篇 |
2011年 | 38053篇 |
2010年 | 22800篇 |
2009年 | 21810篇 |
2008年 | 36639篇 |
2007年 | 39249篇 |
2006年 | 39499篇 |
2005年 | 38437篇 |
2004年 | 37589篇 |
2003年 | 36443篇 |
2002年 | 35793篇 |
2001年 | 63987篇 |
2000年 | 66494篇 |
1999年 | 56407篇 |
1998年 | 15128篇 |
1997年 | 13753篇 |
1996年 | 14195篇 |
1995年 | 13452篇 |
1994年 | 12765篇 |
1993年 | 11790篇 |
1992年 | 44554篇 |
1991年 | 43464篇 |
1990年 | 42216篇 |
1989年 | 40111篇 |
1988年 | 36894篇 |
1987年 | 36234篇 |
1986年 | 33618篇 |
1985年 | 32278篇 |
1984年 | 24136篇 |
1983年 | 20268篇 |
1982年 | 11723篇 |
1981年 | 10691篇 |
1980年 | 9515篇 |
1979年 | 21341篇 |
1978年 | 14821篇 |
1977年 | 12532篇 |
1976年 | 11693篇 |
1975年 | 12623篇 |
1974年 | 14661篇 |
1973年 | 14117篇 |
1972年 | 12944篇 |
1971年 | 11729篇 |
1970年 | 11050篇 |
1969年 | 10024篇 |
排序方式: 共有10000条查询结果,搜索用时 14 毫秒
131.
J Rochemaure P Lehert J Sauvaget M Robillard A Betbeder-Matibet 《Revue de pneumologie clinique》1988,44(1):43-47
Fifty-six patients with recurrent bronchopulmonary infections associated with chronic bronchitis were randomly allocated to 2 groups, to assess whether treatment with an immunomodulator, Diribiotin CK, could enhance resistance to infection. The double-blind, placebo-controlled prospective trial over a 9 month period showed that this immunomodulator was well tolerated and significantly reduced the rate of respiratory tract infection. The drug also significantly reduced the prescribing of antibiotic medication and the rate of absenteism from work. These effects have been demonstrated in a rigorously designed clinical study. This is the first time that a clear clinical activity has been attributed to an inducer of soluble mediators of immunity. 相似文献
132.
133.
LUCAS D.; MENEZ J. F.; BODENEZ P.; BACCINO E.; BARDOU L. G.; FLOCH H. H. 《Alcohol and alcoholism (Oxford, Oxfordshire)》1988,23(1):23-31
Acetaldehyde, the first metabolite of ethanol, reacts with haemoglobinin vitro to produce acetaldehydehaemoglobin adducts.Some clinical studies on the minor haemoglobins have suggestedthat these adducts may be formed in people abusing alcohol.Under hydrolysis of haemoglobin, with oxalic acid at 100°Cin sealed vials, some acetaldehyde was released and then specificallydetermined by HPLC. The kinetics of hydrolysis were studiedusing haemoglobin previously labelled with 14[C] acetaldehyde.The maximum liberation of 14[C] acetaldehyde was obtained after3 hr 30 min hydrolysis and this time factor was then utilizedin the analysis of alcoholic and control haemoglobin. Thus,we have confirmed the formation of acetaldehyde haemoglobinadducts in vivo. It must be noted that the released acetaldehydecorresponds only to an index of the stable adducts. The levelswere higher in alcoholics than in controls (1.417±0.171and 1.295±0.139 nmol/mg Hb, respectively, P<0.001).In conclusion, this marker is not a convenient tool for themonitoring of alcohol exposure levels because of the low differencesbetween alcoholic and control haemoglobins. 相似文献
134.
In this study newly diagnosed male and female lung cancer patients admitted to two Ontario Cancer Foundation treatment clinics were interviewed. Information was obtained on demographic variables, presence of other chronic illness and the following psychosocial attributes: locus of control, social support and personality traits. From the clinic charts, information on stage of disease and pathological diagnosis was obtained. After controlling for the effects of stage and pathological diagnosis, the following psychological variables were found to increase the odds of death from lung cancer among males and females combined at one year after diagnosis: a high need for one aspect of social support, a reserved personality and the extremes of the personality trait soberness vs enthusiasm. 相似文献
135.
Ticks of the Ornithodoros moubata complex were collected from domestic pig sties and dwelling houses, and from a warthog habitat, and tested for the presence of African swine fever (ASF) virus. Collections were made in 9 of the 24 districts of Malawi, these being primarily the districts in which O. moubata is most numerous. ASF virus was isolated from ticks collected in both domestic pig sties and houses in certain villages in Mchinji district where ASF outbreaks had recently occurred. Mchinji district is in the centre of a large ASF enzootic area which stretches into other districts of Malawi and also into Zambia and Mozambique. The high titre of virus in some of the ticks demonstrates that O. moubata can act as a virus reservoir and potential vector of disease in the field situation in Malawi. 相似文献
136.
137.
Juvenile hypocalcemia provokes persistent electroencephalographic change in renally compromised rats
J J Lipman D L White P L Lawrence P E Teschan 《Journal of the American College of Nutrition》1988,7(6):453-460
In view of the putative involvement of calcium in uremic encephalopathy and the critical importance of this element in juvenile development, we examined the effect of temporary restriction of dietary calcium intake on serum chemistry and the quantitative electroencephalogram (Q.EEG) in unilaterally 3/4 nephrectomized juvenile male Sprague-Dawley rats. Animals were renally infarcted at 22-26 days of age (50-74 g) and placed on one of two isocaloric dietary regimens: powdered normal rat diet (ND, n = 25) or low calcium diet (LCD, n = 8) for 30 days. At this time, ND animals showed normal serum chemistries, whereas LCD rats were hypocalcemic and azotemic with significantly elevated blood urea nitrogen (BUN) and serum creatinine concentrations and reduced renal creatinine clearance values. All animals thereafter received ND for 25-34 further days, during which time chronic Q.EEG electrodes were implanted. At the end of the common ND feeding period, serum chemistry values were equal and normal in both groups. The average theta/alpha ratio (TAR) of the overnight Q.EEG was assessed for 3 days. We found that the TAR of previously LCD animals was significantly elevated compared with ND rats. This indicates an encephalopathic slowing of the background rhythm of these animals. We conclude that, following restoration of a transient uremic and hypocalcemic episode induced by LCD feeding, the Q.EEG background frequency of juvenile renally impaired rats was abnormally slow after 30 days of ND feeding. 相似文献
138.
139.
This paper examines the effects of intraocular epinephrine on systemic blood pressure and heart rate during cataract surgery. Sixty-two patients were studied, all of whom received an intraocular infusion of approximately 200 to 300 mL of balanced salt solution with 0.5 mL of epinephrine 1:1000. There was no statistically significant change in blood pressure or heart rate during the time of epinephrine administration. Electrocardiogram monitoring during surgery showed no changes. We believe that dilute concentrations of epinephrine administered during extracapsular cataract extraction pose little threat of systemic toxicity. 相似文献
140.
B. Bogin P. Smith A.B. Orden M.I. Varela Silva J. Loucky 《American journal of human biology》2002,14(6):753-761
Maya families from Guatemala migrated to the United States in record numbers from the late 1970s to the early 1990s. Births to Maya immigrant women have created a sizable number of Maya American children. The height and sitting height of 5 to 12 years children (n = 431) were measured in 1999 and 2000. Leg length was estimated and the sitting height ratio was calculated. These data were compared with a sample of Maya children living in Guatemala measured in 1998 (n = 1,347). Maya American children are currently 11.54 cm taller and 6.83 cm longer‐legged, on average, than Maya children living in Guatemala. Consequently, the Maya Americans have a significantly lower average sitting height ratio (i.e., relatively longer legs in proportion to length of the head and trunk) than do the Maya in Guatemala. These results add support to the hypothesis that both the height and body proportions of human populations are sensitive indicators of the quality of the environment for growth. Am. J. Hum. Biol. 14:753–761, 2002. © 2002 Wiley‐Liss, Inc. 相似文献