全文获取类型
收费全文 | 960篇 |
免费 | 128篇 |
国内免费 | 32篇 |
专业分类
耳鼻咽喉 | 4篇 |
儿科学 | 45篇 |
妇产科学 | 22篇 |
基础医学 | 130篇 |
口腔科学 | 9篇 |
临床医学 | 96篇 |
内科学 | 235篇 |
皮肤病学 | 75篇 |
神经病学 | 58篇 |
特种医学 | 95篇 |
外科学 | 67篇 |
综合类 | 41篇 |
预防医学 | 117篇 |
眼科学 | 4篇 |
药学 | 60篇 |
1篇 | |
肿瘤学 | 61篇 |
出版年
2022年 | 7篇 |
2021年 | 15篇 |
2020年 | 20篇 |
2019年 | 19篇 |
2018年 | 18篇 |
2017年 | 20篇 |
2016年 | 12篇 |
2015年 | 24篇 |
2014年 | 27篇 |
2013年 | 39篇 |
2012年 | 38篇 |
2011年 | 57篇 |
2010年 | 40篇 |
2009年 | 22篇 |
2008年 | 43篇 |
2007年 | 59篇 |
2006年 | 48篇 |
2005年 | 37篇 |
2004年 | 32篇 |
2003年 | 33篇 |
2002年 | 23篇 |
2001年 | 26篇 |
2000年 | 31篇 |
1999年 | 18篇 |
1998年 | 31篇 |
1997年 | 21篇 |
1996年 | 24篇 |
1995年 | 18篇 |
1994年 | 21篇 |
1993年 | 19篇 |
1992年 | 21篇 |
1991年 | 20篇 |
1990年 | 12篇 |
1989年 | 17篇 |
1988年 | 24篇 |
1987年 | 24篇 |
1986年 | 17篇 |
1985年 | 14篇 |
1984年 | 10篇 |
1983年 | 10篇 |
1982年 | 10篇 |
1980年 | 4篇 |
1977年 | 10篇 |
1976年 | 4篇 |
1975年 | 6篇 |
1974年 | 5篇 |
1972年 | 4篇 |
1969年 | 5篇 |
1967年 | 4篇 |
1965年 | 4篇 |
排序方式: 共有1120条查询结果,搜索用时 15 毫秒
1.
2.
L R Baker W J Mallinson M C Gregory E A Menzies W R Cattell H N Whitfield W F Hendry J E Wickham A M Joekes 《British journal of urology》1987,60(6):497-503
Sixty patients with idiopathic retroperitoneal fibrosis presenting between 1965 and 1984 are reviewed. Their mean age at presentation was 56 years and the male:female ratio was 3:1. The commonest presenting symptoms were flank and abdominal pain, weight loss, nausea and polyuria. Physical examination was usually normal, expect for the presence of hypertension. Anaemia and elevation of erythrocyte sedimentation rate were usually present. Proteinuria was found in less than a third of patients at presentation and significant bacteriuria was uncommon. The correct diagnosis was made or suspected in very few patients before referral. The cumulative actuarial survival rate was 86% at 1 year and 78% at 2 years. Seventeen patients died; they were significantly older and more uraemic at the time of referral than those who survived. A few patients did well with either corticosteroid therapy or ureterolysis alone. In the majority, both operation and steroid treatment were necessary. In bilateral obstruction with residual function in both kidneys, bilateral ureterolysis proved superior to unilateral operation (each followed by steroid therapy) in conserving renal function. Operation alone or steroid therapy alone should be considered in cases where steroids or surgery respectively present particular hazards. The less traumatic unilateral operation should be considered in poor risk patients and in those whose renal function is absent on one side. In many survivors, disease activity has persisted for many years. Life-long follow-up is recommended. 相似文献
3.
4.
Anulus fibrosus in bulging intervertebral disks 总被引:1,自引:0,他引:1
In this investigation the association of radial tears of the anulus fibrosus and bulging of the intervertebral disk was studied. An index of disk bulging was measured in sagittal anatomic sections in 149 lumbar disks from 31 cadavers. The indexes of disk bulging were correlated with stages of disk development and the presence of an annular tear. The largest disk-bulging indexes were always associated with radial tears of the anulus. Eighty-four percent of the disks with radial tears had disk-bulging indexes greater than 2.5 mm. Most normal adult disks had an index of less than 2.5 mm. The results challenge the concept that the anulus fibrosus is intact in bulging disks, although ruptured in herniated disks. 相似文献
5.
6.
7.
Combined assessment of intestinal disaccharidases in congenital asucrasia by differential urinary disaccharide excretion.
下载免费PDF全文
![点击此处可从《Journal of clinical pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Investigation of intestinal disaccharide hydrolysis and permeability by means of a non-invasive differential sugar absorption test was performed in a family containing two siblings with primary sucrase-isomaltase deficiency. The procedure, which depends on measurement of urinary excretion ratios after the oral administration of lactose, sucrose, palatinose, lactulose and L-rhamnose, is capable of simultaneous determination of intestinal lactase, sucrase, and isomaltase activity and lactulose:rhamnose permeability. The results corresponded well with those of disaccharidase assay and histological findings in jejunal biopsy tissue obtained from the patients. Palatinose proved a satisfactory substrate for in vivo assessment of intestinal isomaltase activity. The method described provides a reliable and comprehensive assessment of intestinal disaccharide hydrolysis, and simultaneous estimation of permeability assists discrimination of primary from secondary disaccharidase deficiency. The ability to assess three different disaccharidase activities in addition to intestinal permeability by means of a single test, and the simplicity of preservation and transport of urine samples for sugar analysis, makes this a convenient, definitive method for the investigation of defective sugar absorption in both patients and population groups. 相似文献
8.
Casley William L.; Menzies Allan; Girard Michel; Larocque Lyse; Mousseau Nicole; Whitehouse Larry W.; Moon Thomas W. 《Toxicological sciences》1997,40(2):228-237
The 3-demethylation of caffeine can be used as an index of cytochromeP450 CYP1A2 activity in vivo. We compared the plasma levelsof caffeine and the 3-demethylated metabolite, 1,7-dimethylxanthine,in six common inbred strains (A/J, P/J, BALB/cJ, C3H/HeJ, AKR/J,and SWR/J) and one inbred strain (APN) derived in our laboratoryfrom outbred Swiss-Webster mice on the basis of its relativesusceptibility to acetaminophen-induced hepatotoxicity. We foundsignificant variations between a number of the common strains,all of which produced significantly higher caffeine 3-demethylationindices than our APN strain. In three of the six common strains,there was a significant difference between males and females,with the females having consistently lower 1,7-xanthine/caffeineratios. Hepatic Cyp1a2 expression was compared between APN andC3H/HeJ males. Microsomal methoxyresorufin O-demethylation,acetanilide 4-hydroxylation, and CYP1A2 immunoreactive proteinlevels were significantly higher in C3H/HeJ relative to APNmice, as were hepatic CYP1A2 mRNA levels. These results indicatethe importance of strain and gender to the outcome of pharmacologicalor toxicological studies involving CYP1A2-mediated metabolism,as well as the suitability of the plasma 1,7-dimethylxanthine/caffeineratio as a marker of CYP1A2 activity in the mouse. The strikingdifferences observed between the APN and C3H/HeJ mice suggestthat these strains may be suitable for a genetic analysis ofthe regulation of the basal expression of CYP1A2, a key enzymeIn procarcinogen activation. 相似文献
9.
Changes in iron histochemistry after hypoxic-ischemic brain injury in the neonatal rat 总被引:6,自引:0,他引:6
Palmer C Menzies SL Roberts RL Pavlick G Connor JR 《Journal of neuroscience research》1999,56(1):60-71
Iron can contribute to hypoxic-ischemic brain damage by catalyzing the formation of free radicals. The immature brain has high iron levels and limited antioxidant defenses. The objective of this study was to describe the early alterations in nonheme iron histochemistry following a hypoxic-ischemic (HI) insult to the brain of neonatal rats. We induced a HI insult to the right cerebral hemisphere in groups of 7-day-old rats. Rats were anesthetized, then their brains were perfused and fixed at 0, 1, 4, 8, 24 hr, and 1, 2, and 3 weeks of recovery. Forty-micron-thick frozen sections were stained for iron using the intensified Perls stain. Increased iron staining was first detected within the cytoplasm of cells with pyknotic nuclei at 4 hr of recovery. Staining increased rapidly over the first 24 hr in regions of ischemic injury. By 7 days recovery, reactive glia and cortical blood vessels also stained. Increased staining in gray matter persisted at 3 weeks of recovery, whereas white matter tracts had fewer iron-positive cells compared to normal. The early increase in iron staining could be caused by an accumulation of iron posthypoxicischemic injury or a change in iron from nonstainable heme iron to stainable nonheme iron. Regardless of the source, our results indicate that there is an increase in iron available to promote oxidant stress in the neonatal rat brain following hypoxia-ischemia. 相似文献
10.
Early stage nasopharyngeal carcinoma: radiotherapy dose and time factors in tumor control 总被引:1,自引:0,他引:1
Chang JT; See LC; Liao CT; Chen LH; Leung WM; Chen SW; Chen WC 《Japanese journal of clinical oncology》1998,28(3):207-213
OBJECTIVE: To evaluate radiotherapy dose and length of treatment in the
control of early stage nasopharyngeal carcinoma (NPC) treated with a
combination of external radiotherapy and brachytherapy, MATERIALS &
METHODS: We reviewed the records of 133 patients with early stage
nasopharyngeal carcinoma (stage I or II, AJC/UICC staging system) who
received definitive radiotherapy in Chang Gung Memorial Hospital from 1979
to 1991. The median follow-up time was 7.1 years with a minimum of 2 years.
All patients were treated with megavoltage external radiotherapy to the
nasopharynx area (63-72 Gy) followed by high dose rate intracavitary
brachytherapy (5-16.5 Gy in one to three fractions, spaced 1-2 weeks
apart). The median total dose and time of irradiation was 75 Gy (69.8-81.4
Gy) and 11.6 weeks (7.8-20 weeks) respectively. Survival analysis was used
to examine the effect of several variables on prognosis. RESULTS: The
5-year rates were 86.4% for local control, 84.7% for disease free survival,
88.5% for actuarial survival and 84.2% for overall survival. The treatment
group (combination of time and dose of irradiation) was the most important
prognostic factor according to Cox's proportional hazard model. Patients
receiving radiation at a total dose of < or = 75 Gy completed in < 12
weeks showed the best prognosis. CONCLUSION: Treatment time and total
treatment dose are both important factors in treating early stage NPC.
Decreasing the total radiation time to < 12 weeks and not exceeding a
radiation dose of 75 Gy gave the best results.
相似文献