全文获取类型
收费全文 | 667篇 |
免费 | 34篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 9篇 |
妇产科学 | 25篇 |
基础医学 | 67篇 |
口腔科学 | 11篇 |
临床医学 | 74篇 |
内科学 | 182篇 |
皮肤病学 | 2篇 |
神经病学 | 8篇 |
特种医学 | 93篇 |
外科学 | 57篇 |
综合类 | 70篇 |
预防医学 | 33篇 |
眼科学 | 4篇 |
药学 | 22篇 |
中国医学 | 1篇 |
肿瘤学 | 46篇 |
出版年
2021年 | 5篇 |
2019年 | 10篇 |
2018年 | 8篇 |
2017年 | 6篇 |
2016年 | 11篇 |
2015年 | 13篇 |
2014年 | 18篇 |
2013年 | 18篇 |
2012年 | 18篇 |
2011年 | 15篇 |
2010年 | 26篇 |
2009年 | 21篇 |
2008年 | 30篇 |
2007年 | 31篇 |
2006年 | 31篇 |
2005年 | 18篇 |
2004年 | 29篇 |
2003年 | 20篇 |
2002年 | 19篇 |
2001年 | 30篇 |
2000年 | 27篇 |
1999年 | 28篇 |
1998年 | 27篇 |
1997年 | 20篇 |
1996年 | 20篇 |
1995年 | 8篇 |
1994年 | 12篇 |
1993年 | 13篇 |
1992年 | 11篇 |
1991年 | 12篇 |
1990年 | 17篇 |
1989年 | 19篇 |
1988年 | 13篇 |
1987年 | 17篇 |
1986年 | 9篇 |
1985年 | 11篇 |
1984年 | 5篇 |
1983年 | 7篇 |
1981年 | 7篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 8篇 |
1973年 | 6篇 |
1972年 | 2篇 |
1971年 | 3篇 |
1969年 | 2篇 |
1968年 | 2篇 |
1966年 | 2篇 |
排序方式: 共有707条查询结果,搜索用时 0 毫秒
1.
2.
3.
4.
The sonographic appearance of the testis after administration of chemotherapy for metastatic germ cell neoplasm is not well known. Fifty-six patients (60 testes) who were previously treated with chemotherapy for metastatic germ cell neoplasm (originally diagnosed by removal of the contralateral testis or by biopsy of metastatic disease) underwent sonography followed by orchiectomy. The sonographic characteristics found to predict viable intratesticular tumor were: lesion size larger than 5 mm, fewer echoes than adjacent parenchyma (hypoechoic), inhomogeneous echo texture, poor margin definition, cystic areas, or highly hyperechoic foci within a hypoechoic lesion. Fibrosis was predicted by finding single or multiple small, highly hyperechoic lesions. These results suggest the potential for predicting the pathologic diagnosis in some patients after receiving chemotherapy for germ cell neoplasm. 相似文献
5.
Expression of the mitochondrial uncoupling protein gene from the aP2 gene promoter prevents genetic obesity. 总被引:12,自引:3,他引:9 下载免费PDF全文
J Kopecky G Clarke S Enerbck B Spiegelman L P Kozak 《The Journal of clinical investigation》1995,96(6):2914-2923
The brown fat-specific mitochondrial uncoupling protein (UCP) provides a mechanism for generating heat by uncoupling respiration and oxidative phosphorylation. It has been suggested that this system of thermogenesis can provide a defense against obesity. To test this idea, we created a transgenic mouse in which the fat-specific aP2 gene promoter directed Ucp expression in white fat and provided for the constitutive expression of Ucp in brown fat. Transgenic mice showed both Ucp mRNA and immunoreactive UCP in white fat at 2-10% the level normally measured in brown fat. A reduction in subcutaneous fat of aP2-Ucp C57BL/6J mice was observed at 3 mo of age. When the transgene was expressed in Avy genetically obese mice reductions in total body weight and subcutaneous fat stores were observed. Female transgenic Avy mice at 13 mo of age weighed 35 grams, a weight indistinguishable from nontransgenic C57BL/6J mice. Gonadal fat showed an increase in a novel adipocyte derivative that did not accumulate lipids and that constituted approximately 80% of the mass of the tissue in Avy transgenic. A major effect of aP2-Ucp in brown fat was to reduce endogenous gene expression by as much as 95%. The results suggest that UCP synthesized from the aP2 gene promoter is thermogenically active and capable of reducing fat stores. 相似文献
6.
The interaction between tick-borne encephalitis (TBE) virus strain Hypr and mouse peritoneal macrophages was followed in vitro. Macrophages from juvenile mice (8-11 days old) were more permissive for virus infection than macrophages from adults (25-30 days old). Anti-TBE antibody in the subneutralizing dose increased the number of infected macrophages as well as virus release into the culture medium. Concanavalin A (con A), which bound to the virus as well as to the surface of macrophages, increased the uptake of the virus, but it neither enhanced the number of infected cells nor increased the virus release into medium. Antibody and lectin can modify the interaction between TBE virus and macrophages. Nevertheless, the Fc receptor-mediated endocytosis seems to be a necessary prerequisite for enhancing the effect of a ligand. 相似文献
7.
This paper describes the tragic case of a young woman who died of cancer of
the colon after successfully donating eggs to her younger sister. Although
there is no direct link between her operation and the subsequent
development of bowel carcinoma, this case imparts a feeling of unease when
seen in conjunction with other cases reported during the last few years. It
is a reminder that little is known of the long-term consequences of some
aspects of assisted conception. Women undergoing ovarian stimulation for
themselves or a matched recipient have the right to be advised, in an
agreed format, that there is some concern about unproven potential risks
from the stimulatory drugs. The safety of egg donors must assume priority
over all other considerations, including lack of donors or any moral
position. The recent decision by the Human Fertilisation and Embryology
Authority (HFEA) to withdraw any form of payment or recompense to egg
donors does not seem to us to be based on a balance of scientific advances,
patient needs and the ethics of gamete supply. They state that the
intention to withdraw payments was implicit in the 1990 Human Fertilisation
and Embryology (HFE) Act. However the Act was based on the Warnock report
made 6 years earlier. Even in 1990 ovum donation was uncommon and fertility
drugs had not yet caused any unease. The Act provided the HFEA with
discretionary powers to issue directions so that the future policies would
be consistent with any emerging new medical evidence. It is imperative that
the HFEA provide convincing evidence on how the current policy of payment
to donors harms society, donors or recipients, and how in the UK the new
policy will improve medical practice in assisted conception. Successful
pilot studies must precede the implementation of any new policy. Failure to
do this could cause irreversible harm to the practice of assisted
conception using donor gametes, which will ultimately be against the basic
aims of the 1990 HFE Act.
相似文献
8.
T Carlile K J Kopecky D J Thompson J R Whitehead F I Gilbert A J Present B A Threatt P Krook E Hadaway 《JAMA》1985,254(8):1050-1053
Mammographic parenchymal patterns have been proposed as a method of determining women at high risk of developing breast cancer. Wolfe's original report of relative risks as high as 37:1 for "dysplastic" breasts (DY) as compared with adipose breasts (N1), with intermediate values of P1 and P2, were not uniformly confirmed by others. (Relative risks are used here as the equivalent of odds ratios.) A case-control study of 706 breast cancers, each with two matching controls, drawn from 40,000 participants in four Breast Cancer Detection Demonstration Project clinics, was conducted to assess the role of the Wolfe classification of breast parenchymal patterns as a breast-cancer risk factor together with a set of well-established risk factors for breast cancer. Relative risks of 3.1 for DY to N1, 3.5 for P2 to N1, and 2.0 for P1 to N1 were determined. These are comparable to or greater than other known risk factors found in the same population. The Wolfe classification of parenchymal patterns strengthens the basis for clinical judgment, but should not be used exclusively to determine intervention in an individual patient's care. 相似文献
9.
Eighty four out of 2151 militancy trauma patients sustained severe maxillofacial injury from Jan 1990 to March 1993. The resuscitation, stabilisation and intensive care of these patients was based on management priorities of primary resuscitation, care of airway, management of haemodynamics, oxygenation and monitoring. Anaesthesia was administered in a situation when the airway was likely to be compromised and the patients were critically sick. Initial ventilation and oxygenation was the most difficult and could be achieved with satisfactory seal around the face mask by applying water-soaked guaze pieces around the mouth and nose to “fill-in” the defects. Tracheal intubation could be accomplished with intravenous sedation by an experienced anaesthesiologist. Dental occlusion and wiring necessiated the placement of nasotracheal tube for 48-72 hours after surgery.KEY WORDS: Trauma, Maxillofacial injury, Trauma anesthesia, Anaesthesia and critical care 相似文献
10.
One hundred patients undergoing abdominal surgery were included in this prospective study. The role of local application of Betadine, use of synthetic sutures, and use of low pressure subcutaneous suction drainage were evaluated in preventing post-operative wound infection. The infection rate was 15 per cent with Betadine, 15.4 per cent with prolene, 20 per cent with subcutaneous suction drainage and 30.8 per cent in the control group.KEY WORDS: Surgical wound infection, Betadine, Sutures, Infection control 相似文献