全文获取类型
收费全文 | 1627篇 |
免费 | 111篇 |
国内免费 | 4篇 |
专业分类
耳鼻咽喉 | 6篇 |
儿科学 | 56篇 |
妇产科学 | 43篇 |
基础医学 | 206篇 |
口腔科学 | 73篇 |
临床医学 | 106篇 |
内科学 | 361篇 |
皮肤病学 | 50篇 |
神经病学 | 56篇 |
特种医学 | 192篇 |
外国民族医学 | 1篇 |
外科学 | 193篇 |
综合类 | 50篇 |
预防医学 | 128篇 |
眼科学 | 10篇 |
药学 | 76篇 |
中国医学 | 4篇 |
肿瘤学 | 131篇 |
出版年
2023年 | 5篇 |
2022年 | 10篇 |
2021年 | 34篇 |
2020年 | 23篇 |
2019年 | 23篇 |
2018年 | 32篇 |
2017年 | 28篇 |
2016年 | 29篇 |
2015年 | 29篇 |
2014年 | 39篇 |
2013年 | 55篇 |
2012年 | 85篇 |
2011年 | 63篇 |
2010年 | 77篇 |
2009年 | 77篇 |
2008年 | 80篇 |
2007年 | 76篇 |
2006年 | 60篇 |
2005年 | 60篇 |
2004年 | 46篇 |
2003年 | 61篇 |
2002年 | 39篇 |
2001年 | 48篇 |
2000年 | 47篇 |
1999年 | 41篇 |
1998年 | 49篇 |
1997年 | 44篇 |
1996年 | 42篇 |
1995年 | 40篇 |
1994年 | 28篇 |
1993年 | 26篇 |
1992年 | 32篇 |
1991年 | 18篇 |
1990年 | 24篇 |
1989年 | 25篇 |
1988年 | 31篇 |
1987年 | 20篇 |
1986年 | 27篇 |
1985年 | 20篇 |
1984年 | 14篇 |
1983年 | 18篇 |
1982年 | 14篇 |
1981年 | 18篇 |
1980年 | 21篇 |
1979年 | 9篇 |
1978年 | 9篇 |
1976年 | 8篇 |
1975年 | 8篇 |
1974年 | 4篇 |
1969年 | 4篇 |
排序方式: 共有1742条查询结果,搜索用时 15 毫秒
91.
Masclee AA; Hopman WP; Corstens FH; Rosenbusch G; Jansen JB; Lamers CB 《Radiology》1989,173(2):407-410
Both ultrasonography (US) and cholescintigraphy are used to study gallbladder dynamics. The present study was undertaken to determine whether the two methods provide the same or different information relating to gallbladder emptying. Emptying was simultaneously studied with both methods during infusion of graded physiologic doses of cholecystokinin (CCK) in six healthy subjects. Infusion of stepwise increasing doses of CCK, ranging from 0.03 to 0.5 Ivy dog units per kilogram of body weight per hour (IDU/kg.h), induced significant dose-related increases in plasma CCK, decreases in gallbladder volume assessed with US, and gallbladder emptying assessed with cholescintigraphy. The threshold dose for inducing significant gallbladder emptying was 0.13 IDU/kg.h, as determined with both techniques, indicating similar detection limits. There was a highly significant correlation between decreases in gallbladder volume and decreases in radioactive counts over the gallbladder region, with a tendency toward greater gallbladder responses at sonography during the early phase of gallbladder contraction and toward greater responses at cholescintigraphy during the later phase of gallbladder contraction. It is concluded that these methods can be used interchangeably for the quantitation of gallbladder emptying. 相似文献
92.
We describe an automated method for calcium assay, for use with the Cobas-Bio centrifugal analyzer. Calcium is reacted with cresolphthalein complexone and the absorbance of the calcium--dye complex at 575 nm is measured. EDTA is then added to break up the calcium--dye complex and the absorbance at 575 nm is re-measured, to correct for endogenous color and turbidity. Day-to-day precision data, determined over four months, were as follows: mean = 92.9 mg/L, CV = 1.47%; n = 216; mean = 128.7 mg/L, CV = 1.72%; n = 216. Comparison of the Cobas-Bio method (y) with an atomic absorption spectrometric method (x) gave the following results: y = 1.012x--2.05, r = 0.991, Sy/x = 1.2, mean x = 92.63 mg/L, mean y = 91.69 mg/L, n = 74. Hemoglobin, bilirubin, or turbidity does not interfere. At the medical decision value (110 mg/L), the overall analytical error is 4.6 mg/L, which is less than the 5 mg/L allowable (95% confidence limit) error. 相似文献
93.
94.
H W van der Kroon T M van Vroonhoven L T Douglas 《International journal of obesity (2005)》1977,1(4):325-330
Latent obese-hyperglycemic mice exhibit significantly subnormal heart rate and level of oxygen consumption as early as three and eight days post-partum, respectively. Also, loss of body weight during a three-hour fasting period is detectably less extreme in obese than in normal litter mates as early as five days post-partum. Regression analysis of the differences between the latent obese and normal litter mates suggests that these symptoms begin developing at birth. 相似文献
95.
96.
Rearing behavior, locomotor activity, body temperature, and adrenal activity were recorded in male mice from two inbred strains and from two lines selected for rearing frequency. Significant positive correlations between rearing and locomotion indicated that loci responsible for rearing performance may act through a system which regulates the level of arousal. Although strain and line differences were found for behavior, temperature, and adrenal activity, no specific genetic relationship could be established between the behavioral and the physiological variables. 相似文献
97.
Direct demonstration of transsynaptic degeneration in the human visual system: a comparison of retrograde and anterograde changes 总被引:1,自引:0,他引:1
下载免费PDF全文
![点击此处可从《Journal of neurology, neurosurgery, and psychiatry》网站下载免费的PDF全文](/ch/ext_images/free.gif)
RM Beatty AA Sadun LEH Smith JP Vonsattel EP Richardson Jr 《Journal of neurology, neurosurgery, and psychiatry》1982,45(2):143-146
Transneuronal degeneration of retinal ganglion cells was directly demonstrated in a patient who had unilateral removal of the striate cortex forty years prior to necropsy. For comparison, another case is presented showing anterograde transneuronal atrophy forty years after enucleation of one eye. 相似文献
98.
The incidence of penile cancer is low in men who have been circumcised at infancy. It is unknown whether a causative relationship exists between circumcision and the substantially reduced incidence of penile cancer. A normal foreskin has no known aetiological role in the development of penile cancer. A narrow, non-retractable foreskin predisposes the patient to infection and contributes to the development of penile cancer, together with the known risk factors of smoking and human papillomavirus infection. Circumcision represents a complex of social and behavioural factors. Analyses have not taken all of these factors into consideration. It is unlikely that circumcision itself protects against the development of penile cancer. 相似文献
99.
Kroon BK Horenblas S Meinhardt W van der Poel HG Bex A van Tinteren H Valdés Olmos RA Nieweg OE 《European urology》2005,47(5):601-6; discussion 606
PURPOSE: The aim of this study was to evaluate the results of 10 years dynamic sentinel node biopsy experience in penile carcinoma at our institute. PATIENTS AND METHODS: 140 patients with clinically node-negative groins were prospectively included. Lymphoscintigraphy was performed after injection of 99mTechnetium-nanocolloid around the primary tumour. The sentinel node was intraoperatively identified with the aid of patent blue dye and a gamma ray detection probe. Lymph node dissection was performed only if sentinel node metastasis was found. Median follow-up was 52 months (range 5-129). RESULTS: Lymphoscintigraphy visualized at least 1 sentinel node in 138 patients. Sentinel node metastasis was found in 37 inguinal regions of 31 patients. The sentinel node was the only tumour-positive node in 78% (29/37) of the dissection specimens. Complications occurred in 8% (17/206) of the operated groins. False-negative results were encountered in 6 patients resulting in a false-negative rate of 16% (6/37 patients). 5-year disease-specific survival was 96% and 66% for patients with a tumour-negative sentinel node and tumour-positive sentinel node, respectively (p=0.001). CONCLUSION: Dynamic sentinel node biopsy in penile carcinoma is of important diagnostic, prognostic, and therapeutic value at the cost of only minor morbidity. 相似文献
100.
Patients with penile carcinoma benefit from immediate resection of clinically occult lymph node metastases 总被引:6,自引:0,他引:6
Kroon BK Horenblas S Lont AP Tanis PJ Gallee MP Nieweg OE 《The Journal of urology》2005,173(3):816-819
PURPOSE: In this retrospective study we compared the clinical outcome of early vs delayed excision of lymph node metastases in patients with penile squamous cell carcinoma. MATERIALS AND METHODS: A total of 40 patients with a T2-3 penile carcinoma with lymph node metastases were included in this study. All patients initially presented with bilateral impalpable lymph nodes. In 20 patients (50%) metastases were removed when they became clinically apparent during meticulous followup (median interval 6 months, range 1 to 24). There were 20 patients (50%) who underwent resection of inguinal metastases detected on dynamic sentinel node biopsy before they became palpable. The histopathological characteristics of the tumors and lymph nodes were reevaluated. RESULTS: The 2 populations were similar in terms of patient age, T-stage, pathological tumor grade, vascular invasion and infiltration depth. Disease specific 3-year survival of patients with positive lymph nodes detected during surveillance was 35% and in those who underwent early resection, 84% (log rank p = 0.0017). In multivariate analysis early resection of occult inguinal metastases detected on dynamic sentinel node biopsy was an independent prognostic factor for disease specific survival (p = 0.006). CONCLUSIONS: Early resection of lymph node metastases in patients with penile carcinoma improves survival. 相似文献