全文获取类型
收费全文 | 1237篇 |
免费 | 68篇 |
国内免费 | 48篇 |
专业分类
耳鼻咽喉 | 5篇 |
儿科学 | 51篇 |
妇产科学 | 174篇 |
基础医学 | 100篇 |
口腔科学 | 22篇 |
临床医学 | 144篇 |
内科学 | 170篇 |
皮肤病学 | 19篇 |
神经病学 | 63篇 |
特种医学 | 192篇 |
外科学 | 52篇 |
综合类 | 36篇 |
一般理论 | 1篇 |
预防医学 | 115篇 |
眼科学 | 5篇 |
药学 | 77篇 |
中国医学 | 1篇 |
肿瘤学 | 126篇 |
出版年
2021年 | 7篇 |
2020年 | 12篇 |
2019年 | 8篇 |
2018年 | 8篇 |
2017年 | 10篇 |
2015年 | 39篇 |
2014年 | 46篇 |
2013年 | 82篇 |
2012年 | 38篇 |
2011年 | 32篇 |
2010年 | 34篇 |
2009年 | 32篇 |
2008年 | 29篇 |
2007年 | 72篇 |
2006年 | 34篇 |
2005年 | 45篇 |
2004年 | 27篇 |
2003年 | 38篇 |
2002年 | 31篇 |
2001年 | 20篇 |
2000年 | 40篇 |
1999年 | 36篇 |
1998年 | 29篇 |
1997年 | 33篇 |
1996年 | 22篇 |
1995年 | 30篇 |
1994年 | 27篇 |
1993年 | 19篇 |
1992年 | 22篇 |
1991年 | 22篇 |
1990年 | 28篇 |
1989年 | 32篇 |
1988年 | 29篇 |
1987年 | 17篇 |
1986年 | 25篇 |
1985年 | 16篇 |
1984年 | 18篇 |
1983年 | 12篇 |
1982年 | 11篇 |
1981年 | 14篇 |
1980年 | 12篇 |
1979年 | 15篇 |
1978年 | 11篇 |
1977年 | 12篇 |
1976年 | 17篇 |
1974年 | 8篇 |
1970年 | 9篇 |
1968年 | 8篇 |
1947年 | 6篇 |
1927年 | 7篇 |
排序方式: 共有1353条查询结果,搜索用时 15 毫秒
51.
52.
Saravanan R Rajendran P Thyagarajan SP Smythe LD Norris MA Symonds ML Dohnt MF 《Annals of tropical medicine and parasitology》2000,94(5):503-506
Leptospira were successfully isolated from the urine of an Indian patient who had been clinically diagnosed as having leptospirosis. In an attempt to determine the source of this infection, 28 rats (Rattus rattus) and 58 bandicoots (Bandicota bengalensis) living in the vicinity of the patient's home in Avadi, a suburban area of the city of Chennai (Madras), India, were then investigated. Each animal was checked for infection by microscopical examination of fresh and stained urine, serological analysis of serum, and the culture of urine and kidney samples. Direct, dark-field, observation of fresh urine samples and examination of urine samples after Fontana's silver staining were found to be the least sensitive of the tests used. The results of the serological microscopic agglutination test (MAT) indicated that four (14.3%) of the rats and nine (16.1%) of the bandicoots had significant agglutinins, predominantly for the serogroups icterohaemorrhagiae and autumnalis. Leptospira were isolated from at least one culture of samples from one rat and each of four bandicoots. Each of these rodent isolates and the human isolate were typed as Leptospira interrogans serovar autumnalis. 相似文献
53.
D A Symonds 《Gynecologic oncology》1990,39(3):272-276
In a series of 38 nonmetastasizing and 29 metastasizing endometrial cancers, histologic subtype, aneuploidy, nuclear grade, and depth of myometrial invasion were the features most distinctly separating these two groups of patients. The most important factor was histologic type: papillary, papillary serous, adenosquamous, clear cell, and diffusely infiltrating carcinomas were strongly correlated with metastasis using chi square analysis. Nuclear grade 3 and deep myometrial invasion were similar to each other in sensitivity and predictive value, and both were also strongly correlated with metastatic risk. Aneuploidy, also correlated with metastasis, was similar to nuclear grade 3 and deep myometrial invasion in predictive value but was more sensitive. DNA analysis appeared to be most useful when histologic studies were inconclusive in assigning a high degree of risk. Twice as many aneuploid carcinomas having nuclear grade 2 (intermediate risk) morphology proved to be metastatic. A similar relationship was found with deep myometrial invasion. A quantitative correlation between the DNA index and the risk of metastasis was found; a DNA index above 1.5 was a strong attribute of the metastatic group. 相似文献
54.
Study of internal structure of the human fetus in utero by echo-planar magnetic resonance imaging 总被引:1,自引:0,他引:1
I R Johnson M K Stehling A M Blamire R J Coxon A M Howseman B Chapman R J Ordidge P Mansfield E M Symonds B S Worthington 《American journal of obstetrics and gynecology》1990,163(2):601-607
The ultrafast echo-planar magnetic resonance imaging technology, developed and built in Nottingham, has been used to produce the first snapshot images of the human fetus in utero. The imager, operating at a proton resonance frequency of 22 MHz, produces transaxial views in 64 or 128 milliseconds. These images comprise either 64 x 128 or 128 x 128 pixels with an in-plane resolution of 3 x 3 mm2. The slice thickness is 10 mm. Fetal scans of up to 32 contiguous slices are produced in a few minutes. These have been used to study the internal structure of the uterus and the fetus in a range of cases with gestations ranging from 26 weeks to term. Echo-planar imaging seems particularly suitable as an imaging modality since its high speed obviates image blurring arising from fetal motion. 相似文献
55.
Gangadhar NL Rajasekhar M Smythe LD Norris MA Symonds ML Dohnt MF 《Revue scientifique et technique (International Office of Epizootics)》2000,19(3):793-799
Isolation of Leptospira from the kidneys of Rattus rattus wroughtoni hinton, Rattus rattus rufescens, Bandicota bengalensis and Bandicota indica was attempted in Bangalore in southern India. In total, 296 spirochaetes were isolated from 1,348 kidney cultures (an isolation rate of 22%). A batch of fifty-six isolates from India was identified, based on serological and polymerase chain reaction analysis, of which twenty-three isolates were identified as L. inadai by the World Health Organization/Food and Agriculture Organization Collaborating Centre for Reference and Research on Leptospirosis, in Brisbane. This is the first record of isolation of L. inadai from rodents. The preponderance of L. inadai in four different species of rodents suggests that these animals could be the natural reservoir hosts of L. inadai, and raises a critical question as to the likely impact of this species of Leptospira on the renal carrier status of other Leptospira pathogenic to humans and animals in this part of India. Virulence studies conducted at the University of Trieste in Italy, revealed that isolates of L. inadai from India were moderately or totally serum resistant when subjected to a serum killing test. To establish the possible seroprevalence of this species in the population, the inclusion of L. inadai in the battery of leptospiral antigens used for sero-epidemiological studies is recommended. 相似文献
56.
Clinical implications for immunoscintigraphy in patients with ovarian malignancy: a preliminary study using monoclonal antibody 791T/36 总被引:1,自引:0,他引:1
E M Symonds A C Perkins M V Pimm R W Baldwin J G Hardy D A Williams 《British journal of obstetrics and gynaecology》1985,92(3):270-276
Twelve patients with suspected primary and recurrent carcinoma of the ovary have undergone immunoscintigraphy with an antitumour monoclonal antibody in order to assess the impact of the technique on patient management. Consistent tumour uptake of radiolabelled antibody was visualized in malignant tumours after subtraction of the blood background activity. Eight patients were imaged before surgery and in all of these the sites of uptake visualized on the images agreed with the surgical findings. In one patient with recurrent disease the imaging information was used as an aid for establishing the extent of external beam radiotherapy. A repeat study in this patient 6 months later revealed a reduction in the size of the tumour, which still concentrated labelled antibody and confirmed the viability of repeat investigations. Immunoscintigraphy was capable of providing diagnostic information which may offer an alternative to second-look surgery in these patients. 相似文献
57.
Magnetic resonance imaging and placenta previa 总被引:3,自引:0,他引:3
M C Powell J Buckley H Price B S Worthington E M Symonds 《American journal of obstetrics and gynecology》1986,154(3):565-569
Twenty-five women with diagnoses of placenta previa on ultrasound examination underwent magnetic resonance imaging examination. An assessment of placental position and the relationship of the lower placental edge to the internal os was made with both techniques and the results were compared. There was complete correlation of placental localization but significant differences were found in the determination of the degree of placenta previa. This occurred more often with posteriorly situated placentas. Magnetic resonance imaging directly affected management with regard to delivery in seven cases. Magnetic resonance imaging provides a technique capable of accurately assessing placental position and its relationship to the cervix, thereby leading to a reduction in hospitalization and inappropriate operations. 相似文献
58.
We investigated the effect of toremifene, interferon-alpha2a, interferon-alpha2b and interferon-alpha2c, singly and in combination for their effect on the growth of ZR-75-1 human breast cancer cells. Median effect analysis was used to determine synergistic or additive effects. Anti-proliferative studies showed that the growth of ZR-75-1 cells was inhibited to a greater extent by combination treatment with toremifene plus interferon-alpha2a, resulting in a synergistic interaction (CI <1) for all concentrations tested. A combination of toremifene plus interferon-alpha2b resulted in a synergistic interaction (CI <1) for the two highest concentrations of toremifene (10(-6) and 10(-7) M) and an additive effect (CI approximately equal to 1) for the lower concentrations (10(-8) to 10(-10) M). When toremifene was combined with interferon-alpha2c no additive or synergistic interaction was determined. 相似文献
59.
60.