全文获取类型
收费全文 | 1028篇 |
免费 | 77篇 |
国内免费 | 9篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 45篇 |
妇产科学 | 5篇 |
基础医学 | 104篇 |
口腔科学 | 44篇 |
临床医学 | 92篇 |
内科学 | 184篇 |
皮肤病学 | 41篇 |
神经病学 | 37篇 |
特种医学 | 163篇 |
外国民族医学 | 1篇 |
外科学 | 147篇 |
综合类 | 39篇 |
预防医学 | 89篇 |
眼科学 | 35篇 |
药学 | 49篇 |
中国医学 | 1篇 |
肿瘤学 | 33篇 |
出版年
2021年 | 7篇 |
2020年 | 5篇 |
2019年 | 13篇 |
2018年 | 18篇 |
2017年 | 14篇 |
2016年 | 14篇 |
2015年 | 30篇 |
2014年 | 15篇 |
2013年 | 37篇 |
2012年 | 30篇 |
2011年 | 36篇 |
2010年 | 36篇 |
2009年 | 52篇 |
2008年 | 30篇 |
2007年 | 29篇 |
2006年 | 21篇 |
2005年 | 18篇 |
2004年 | 37篇 |
2003年 | 26篇 |
2002年 | 18篇 |
2001年 | 11篇 |
2000年 | 8篇 |
1999年 | 23篇 |
1998年 | 55篇 |
1997年 | 65篇 |
1996年 | 57篇 |
1995年 | 46篇 |
1994年 | 41篇 |
1993年 | 38篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 19篇 |
1989年 | 15篇 |
1988年 | 23篇 |
1987年 | 26篇 |
1986年 | 23篇 |
1985年 | 12篇 |
1984年 | 8篇 |
1983年 | 9篇 |
1982年 | 22篇 |
1981年 | 5篇 |
1980年 | 10篇 |
1979年 | 5篇 |
1978年 | 6篇 |
1977年 | 7篇 |
1976年 | 9篇 |
1975年 | 7篇 |
1970年 | 6篇 |
1968年 | 7篇 |
1966年 | 4篇 |
排序方式: 共有1114条查询结果,搜索用时 0 毫秒
31.
Fifty women with polycystic ovaries took part in a prospective randomized
study. All women required treatment by in-vitro fertilization (IVF) for
reasons other than anovulation. They had all previously undergone ovarian
stimulation with gonadotrophin therapy which had failed to result in
pregnancy or had been abandoned due to high risk of developing ovarian
hyperstimulation syndrome (OHSS). Twenty-five women were treated by
long-term pituitary desensitization followed by gonadotrophin therapy,
oocyte retrieval and embryo transfer (group 1). Twenty-five women underwent
laparoscopic ovarian electrocautery after pituitary desensitization
followed by gonadotrophin therapy, oocyte retrieval and embryo transfer
(group 2). A significantly higher number of women in group 1 had to have
the treatment cycle abandoned due to impending or actual OHSS, determined
by endocrine and clinical findings. In addition, the development of
moderate or severe OHSS in completed cycles was higher in group 1. The
pregnancy rate and miscarriage rates in the two treatment groups were
similar. The authors propose that laparoscopic ovarian electrocautery is a
potentially useful treatment for women who have previously had an IVF
treatment cycle cancelled due to risk of OHSS or who have suffered OHSS in
a previous treatment cycle.
相似文献
32.
The bias favoring deletion over inversion in DH-JH rearrangement has been
known for years, but the underlying mechanism has yet to be fully defined.
It has been suggested that the ratio of deletion/inversion is determined by
the combined effect of two factors: (i) the relative strengths of 5' and 3'
recombination signal sequences (RSS) of a DH segment, and (ii) the
efficiency with which the deletional product (one joint) forms relative to
the inversional product (two joints). In this study, we analyzed for the
first time the effect of factor 1 alone on the biased 3' RSS utilization in
DH-JH joining by using deletional plasmids in an extrachromosomal substrate
V(D)J recombination assay. It was found that the 3' RSS and associated
coding end (12 bp) mediate recombination more efficiently than the 5'
RSS/coding end DH-JH plasmids. These results demonstrate that the effect of
the RSS/coding end alone can account, at least partially, for the
predominant deletion in DH-JH recombination. The potential effect of the
relative strength of RSS and associated coding end on the ordered
rearrangement of DH-JH followed by VH to DH-JH was also assessed. When
recombination frequencies of D-->J (3' DH to J3) were compared with
frequencies of V-- >D (VHPJ14 to 3' DH or VHOX2 to 3' DH), it was found
that V-->D joining was, if anything, more efficient than D-->J
joining. Therefore, if all three segments were accessible, RSS/coding end
effects would not contribute to the ordered rearrangement of the IgH locus.
相似文献
33.
Debelenko LV; Brambilla E; Agarwal SK; Swalwell JI; Kester MB; Lubensky IA; Zhuang Z; Guru SC; Manickam P; Olufemi SE; Chandrasekharappa SC; Crabtree JS; Kim YS; Heppner C; Burns AL; Spiegel AM; Marx SJ; Liotta LA; Collins FS; Travis WD; Emmert-Buck MR 《Human molecular genetics》1997,6(13):2285-2290
Lung carcinoids occur sporadically and rarely in association with multiple
endocrine neoplasia type 1 (MEN1). There are no well defined genetic
abnormalities known to occur in these tumors. We studied 11 sporadic lung
carcinoids for loss of heterozygosity (LOH) at the locus of the MEN1 gene
on chromosome 11q13, and for mutations of the MEN1 gene using dideoxy
fingerprinting. Additionally, a lung carcinoid from a MEN1 patient was
studied. In four of 11 (36%) sporadic tumors, both copies of the MEN1 gene
were inactivated. All four tumors showed the presence of a MEN1 gene
mutation and loss of the other allele. Observed mutations included a 1 bp
insertion, a 1 bp deletion, a 13 bp deletion and a single nucleotide
substitution affecting a donor splice site. Each mutation predicts
truncation or potentially complete loss of menin. The remaining seven
tumors showed neither the presence of a MEN1 gene mutation nor 11q13 LOH.
The tumor from the MEN1 patient showed LOH at chromosome 11q13 and a
complex germline MEN1 gene mutation. The data implicate the MEN1 gene in
the pathogenesis of sporadic lung carcinoids, representing the first
defined genetic alteration in these tumors.
相似文献
34.
It is highly recommended to conduct a prophylactic check for any dental problems on patients who suffer from leukaemia before chemotherapy begins. Bacteraemia caused by oral microflora may be very dangerous for patients with haematological malignancies. However, it should be noted that the prophylactic process itself might bring about life-threatening complications if there is only a short interval between dental treatment and the beginning of chemotherapy, or if the dental treatment is too aggressive. We present a case where this prophylactic procedure produced life-threatening complications for a patient with acute myeloid leukaemia. 相似文献
35.
目的探讨敏感性编码技术(SENSE)前瞻性门控螺旋相位对比MR检查序列在儿童与成人先天性心脏病检查的可行性。材料与方法当地伦理委员会批准该项研究,所有 相似文献
36.
目的采用心脏MR(CMR)前瞻性研究冠状动脉斑块对心肌缺血的预测价值。方法 52例行冠状动脉造影(CA)后评定为可疑冠心病(CAD)的病人进行了CMR和 相似文献
37.
HH Chen MR Phillips H Cheng QQ Chen XD Chen D Fralick YE Zhang M Liu J Huang M Bueber 《上海精神医学》2012,24(6):305-321
The following document is a translation of the first national mental health law of the People''s Republic of China, which was adopted by the National People''s Congress on October 26, 2012. The original Chinese version of the law is available at the official government website: http://www.gov.cn/jrzg/2012-10/26/content_2252122.htm. The translation was completed by a team of translators at the Shanghai Mental Health Center at the Shanghai Jiao Tong University School of Medicine. The translators have added footnotes at the end of the document that explain their choices in sections where alternative translations are possible and that provide background information for sections that may be confusing to readers unfamiliar with China. This translation should be cited as follows:ChenHH, Phillips MR, Cheng H, Chen QQ, Chen XD, Fralick D, Zhang YE, Liu M, Huang J, Bueber M. Mental Health Law of the People''s Republic of China (English translation with annotations). Shanghai Archives of Psychiatry. 2012; 24(6):305-321. doi:10.3969/j.issn.1002-0829.2012.06.001Shanghai Archives of Psychiatry 相似文献
38.
V Ramesh M Ramam MR Capoor S Sugandhan J Dhawan G Khanna 《Journal of the European Academy of Dermatology and Venereology》2010,24(10):1220-1225
Background Subcutaneous zygomycosis is an uncommon condition observed in tropics. Few series have been published, particularly from the northern regions of India. Objectives The aim of this study was to describe clinical, investigative and therapeutic details in subcutaneous zygomycosis observed in two teaching hospitals in Delhi. Patients and methods Ten patients seen over a period of 10 years (1999–2009) form the material for this report. Results There were four children and six adults. In four children, the presentation was a subcutaneous localized mass or gradually spreading plaque. In the others, it was observed over nasal region of face, spreading inward into mucosal sites and paranasal sinuses, and outward to the contiguous areas. Regional lymphadenopathy was present in two with facial lesions. Majority showed a granulomatous infiltrate with admixture of other cells, mainly eosinophils. Aseptate or poorly septate hyphae were observed in seven. In one patient in whom no hyphae were observed, there was dense perivascular inflammation. Organisms were cultured from four patients, Basidiobolus ranarum in two and Syncephalastrum racemosum in two. The main therapy used was a saturated solution of potassium iodide (KI). Four received only KI of which two attained cure after 3 months and 9 months respectively, and the other two showed signs of regression. In one boy subsidence was associated with reduced circumference of thigh. Ketoconazole or itraconazole was given with KI to hasten regression when response was slow or there were side‐effects to KI. Conclusion Awareness and early recognition will prevent disfigurement produced by advanced disease, misdiagnosis and unnecessary surgical intervention. 相似文献
39.
Differentiation of thrombi from slow flow in the pulmonary arteries, sometimes observed in the presence of pulmonary arterial hypertension, can be equivocal. Magnetic resonance (MR) imaging was performed in a patient with chronic pulmonary thromboembolism and pulmonary arterial hypertension using an electrocardiographically gated technique that allowed visualization of the pulmonary arteries at the end of diastole and multiple times during systole. These images were compared with those of a patient with primary pulmonary hypertension and those of healthy subjects. Thrombi were discrete structures, seen throughout the cardiac cycle on both the first and second spin-echo images, and decreased in signal intensity on the second image. Slow flow increased in signal intensity and changed in structure during the cardiac cycle and was seen best on the second image. MR may play an important role in excluding large central thrombi as the cause of pulmonary arterial hypertension. It is a noninvasive method for defining pulmonary arterial wall thickness and for direct visualization of chronic pulmonary thrombus. 相似文献
40.
Pulmonary manifestations of AIDS: review of 106 episodes 总被引:9,自引:0,他引:9
We reviewed the clinical records and chest radiographs of all patients admitted to our institution between 1982 and 1984 who had pulmonary disease and who were later proved to have acquired immunodeficiency syndrome (AIDS) (95 patients). Diffuse parenchymal lung disease was the most common finding. These infiltrates were usually interstitial and caused by Pneumocystis carinii pneumonia or P. carinii combined with cytomegalovirus infection. Focal, multilobar, interstitial infiltrates were also often seen and usually caused by P. carinii or P. carinii and cytomegalovirus infections. Rarely, well-defined, multiple, interstitial nodules less than 10 mm in diameter were the only or predominant characteristic and were seen only in association with Mycobacterium tuberculosis or Cryptococcus neoformans infections or Kaposi sarcoma. Hilar or mediastinal adenopathy occurred in 17 of the 21 patients with M. tuberculosis or C. neoformans infections. In contrast, only 4% of patients with P. carinii infections presented with these findings. We also found that hilar or mediastinal adenopathy was not significantly associated with peripheral adenopathy. Lung cavitation, pleural effusion, or a normal chest radiograph was uncommon. 相似文献