全文获取类型
收费全文 | 1347638篇 |
免费 | 97745篇 |
国内免费 | 2175篇 |
专业分类
耳鼻咽喉 | 18731篇 |
儿科学 | 44411篇 |
妇产科学 | 38989篇 |
基础医学 | 196762篇 |
口腔科学 | 37036篇 |
临床医学 | 115852篇 |
内科学 | 265642篇 |
皮肤病学 | 27592篇 |
神经病学 | 105793篇 |
特种医学 | 52276篇 |
外国民族医学 | 367篇 |
外科学 | 207463篇 |
综合类 | 27510篇 |
现状与发展 | 1篇 |
一般理论 | 369篇 |
预防医学 | 99252篇 |
眼科学 | 30789篇 |
药学 | 102542篇 |
2篇 | |
中国医学 | 2560篇 |
肿瘤学 | 73619篇 |
出版年
2018年 | 13416篇 |
2016年 | 11339篇 |
2015年 | 13115篇 |
2014年 | 18206篇 |
2013年 | 27539篇 |
2012年 | 38479篇 |
2011年 | 40970篇 |
2010年 | 24090篇 |
2009年 | 22571篇 |
2008年 | 39605篇 |
2007年 | 42985篇 |
2006年 | 43470篇 |
2005年 | 42475篇 |
2004年 | 40951篇 |
2003年 | 39412篇 |
2002年 | 38904篇 |
2001年 | 58829篇 |
2000年 | 60179篇 |
1999年 | 51438篇 |
1998年 | 15098篇 |
1997年 | 13565篇 |
1996年 | 13721篇 |
1995年 | 12954篇 |
1994年 | 12237篇 |
1993年 | 11352篇 |
1992年 | 41471篇 |
1991年 | 40807篇 |
1990年 | 40256篇 |
1989年 | 39079篇 |
1988年 | 36464篇 |
1987年 | 35682篇 |
1986年 | 34070篇 |
1985年 | 32516篇 |
1984年 | 24285篇 |
1983年 | 21197篇 |
1982年 | 12803篇 |
1981年 | 11336篇 |
1980年 | 10584篇 |
1979年 | 22918篇 |
1978年 | 16174篇 |
1977年 | 13974篇 |
1976年 | 13171篇 |
1975年 | 14358篇 |
1974年 | 16844篇 |
1973年 | 16223篇 |
1972年 | 15451篇 |
1971年 | 14354篇 |
1970年 | 13322篇 |
1969年 | 12833篇 |
1968年 | 12045篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
G H Ross 《Toxicology and industrial health》1992,8(4):87-94
The essential features of treatment for chemical sensitivity are: 1) Encouraging the provision of clean air, food, water, and surroundings. 2) Identifying substances to which the patient is sensitive, with subsequent a) enhanced avoidance, or b) specific immunotherapy to reduce the patient's reactivity to those substances. 3) Assessing and enhancing the patient's nutritional status to maximize the body's ability to detoxify and to minimize the free-radical production and oxidative stress of xenobiotics. 4) Addressing concurrent problems such as infections, immunosuppression, and other medical conditions in an appropriate fashion. 5) Evaluating the patient's psychologic status and addressing any social and emotional problems in a compassionate manner. The author believes that multiple chemical sensitivity is a real condition with documented physiologic abnormalities. It is not a functional or psychologic illness or a belief system of the patient. Second, this condition is diagnosable and treatable by various means. These treatment options not only make common sense but usually result in significant improvement for these unfortunate patients, who deserve the very best efforts of their health care providers. 相似文献
82.
A Moberg Wing K Wing K Tholin R Sj?str?m B Sandstr?m G Hallmans 《European journal of clinical nutrition》1992,46(8):585-595
Exposure to cadmium via the diet is known to depend to a large extent on the intake of cereal grains, particularly the high-fibre fractions of wheat. Subjects with low iron status absorb more cadmium than those with better iron status. The purpose of the present study was to determine to what extent cadmium accumulation in human placenta is affected by the intake of grain fibre and maternal iron status during pregnancy. Thirty-nine pregnant women participated in the study. In each trimester the women were requested to complete a dietary history and to allow blood samples to be taken for haemoglobin, serum ferritin and serum thiocyanate determinations, the latter as a marker for smoking. At delivery the whole placenta was taken for the determination of the cadmium concentration. The 32 women who had serum thiocyanate levels less than 70 mumol/l, who had completed at least one dietary history and from whom a blood sample was obtained in the third trimester, were included in the final statistical analyses. In the group of women who consumed less than the median intake of grain fibre and had more than 15 micrograms ferritin/l serum in the third trimester, the placenta cadmium concentration was nearly half that in the placentae of women who had consumed more grain fibre or had lower iron status in late pregnancy. 相似文献
83.
Premalignant lesions and nonsquamous malignancy of the penis and carcinoma of the scrotum. 总被引:2,自引:0,他引:2
P F Schellhammer G H Jordan E L Robey J T Spaulding 《The Urologic clinics of North America》1992,19(1):131-142
Premalignant lesions of the penis include cutaneous horn, balanitis xerotica obliterans, and leukoplakia. The true incidence of progression of each of these to squamous-cell carcinoma is unknown. Bowenoid papulosis, erythroplasia of Queyrat, and Bowen's disease are histologically identical to in situ carcinoma. Although the first is consistently benign, the latter two regularly evolve into invasive cancer. Malignant scrotal lesions include squamous-cell carcinoma, liposarcoma, leiomyosarcoma, basal-cell carcinoma, extramammary Paget's disease, erythroplasia of Queyrat, malignant melanoma, and metastases. Hemangioma can be confused with carcinoma. 相似文献
84.
85.
Van Landeghem G; Haese P; Lamberts L; Barata J; DeBroe M 《Nephrology, dialysis, transplantation》1997,12(8):1692-1698
Background: The association between aluminium and
dialysis encephalopathy and deterioration of the neurological state during
desferrioxamine treatment of dialysis patients is well established. At
present little is known about the speciation and the mechanisms underlying
the element's neurotoxicity. Methods. Aluminium speciation was performed in
cerebrospinal fluid samples of acutely aluminium-intoxicated dialysis
patients using a recently developed high-performance liquid
chromatographic/electro-thermal atomic absorption spectrometric hybrid
method. Results: Baseline cerebrospinal fluid
aluminium levels of samples taken shortly after the intoxication were low
but elevated (5.0±2.0 &mgr;g/l, n=3) as compared to subjects
with normal renal function (<1 &mgr;g/l). In contrast to the
situation noted in serum and to the iron speciation in cerebrospinal fluid,
aluminium was not bound to transferrin but appeared as two distinct
compounds, the main fraction eluting at the elution volume of aluminium
citrate/silicate. The second compound was not identified. Forty-four hours
after desferrioxamine administration the cerebrospinal fluid aluminium
levels had increased up to a concentration of 10.3±2.5
&mgr;g/l (n=3). This was accompanied by a change in the speciation
profile with aluminium appearing at the elution volume of aluminoxamine.
Conclusion: Our findings may contribute to a better
understanding of the neurotoxic effects of aluminium and its
desferrioxamine chelate in dialysis patients. 相似文献
86.
87.
88.
Variations of the medial and inferior choanal limits may facilitate snoring. These are: 1) short vomer without crista choanalis vomeris and adaptational formations, 2) extremely concave posterior margin of the hard palate leading to disproportion between the muscular and aponeurotic part of m. tensor veli palatini and hence to a flabby soft palate especially during sleep, and 3) neonatal relation of the height and width of the choane resulting in a very large choanal region instead of relative reduction of choanal width compared to its increasing height. All these variations result in a flabby soft palate especially during sleep and may lead to formation of whirles of inspired air and snoring. 相似文献
89.
Various forms of signal processing are used in modern ASP hearing aids. The present study investigated the relationship between sentence recognition ability and two types of signal processing used in commercially available hearing aids. Results indicated a significant improvement in sentence recognition ability employing an instrument with adaptive compression (variable release time) versus an instrument with an adaptive high-pass filter with short attack and release times. Data were obtained for a single-talker competing message at several message-to-competition ratios. The adaptive compression system may prove to be beneficial to hearing-impaired listeners in certain background noise environments. 相似文献
90.