全文获取类型
收费全文 | 678篇 |
免费 | 67篇 |
国内免费 | 1篇 |
专业分类
耳鼻咽喉 | 3篇 |
儿科学 | 40篇 |
妇产科学 | 9篇 |
基础医学 | 77篇 |
口腔科学 | 23篇 |
临床医学 | 60篇 |
内科学 | 147篇 |
皮肤病学 | 14篇 |
神经病学 | 54篇 |
特种医学 | 17篇 |
外国民族医学 | 1篇 |
外科学 | 68篇 |
综合类 | 8篇 |
一般理论 | 1篇 |
预防医学 | 80篇 |
眼科学 | 36篇 |
药学 | 77篇 |
中国医学 | 9篇 |
肿瘤学 | 22篇 |
出版年
2023年 | 3篇 |
2022年 | 20篇 |
2021年 | 32篇 |
2020年 | 17篇 |
2019年 | 24篇 |
2018年 | 34篇 |
2017年 | 25篇 |
2016年 | 28篇 |
2015年 | 32篇 |
2014年 | 37篇 |
2013年 | 41篇 |
2012年 | 61篇 |
2011年 | 77篇 |
2010年 | 37篇 |
2009年 | 26篇 |
2008年 | 38篇 |
2007年 | 38篇 |
2006年 | 33篇 |
2005年 | 23篇 |
2004年 | 14篇 |
2003年 | 19篇 |
2002年 | 14篇 |
2001年 | 14篇 |
2000年 | 9篇 |
1999年 | 3篇 |
1998年 | 6篇 |
1997年 | 1篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 1篇 |
1992年 | 5篇 |
1991年 | 3篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 1篇 |
1985年 | 1篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1971年 | 1篇 |
排序方式: 共有746条查询结果,搜索用时 296 毫秒
41.
A 54 year old man is described with signs compatible with ocular myasthenia gravis and an apparent excellent response to pyridostigmine. Subsequent clinical progression and further investigation suggested the presence of an inflammatory brain stem lesion, which responded to corticosteroid therapy. Clinical relapse, including the development of central neurogenic hyperventilation, led to a brain stem biopsy, confirming a diagnosis of B cell lymphoma. This case illustrates the propensity of primary CNS lymphoma (PCNSL) to mimic other conditions. Brain MRI is mandatory in presumed "test negative" ocular myasthenia with atypical clinical findings. Spontaneous regression of PCNSL or response to corticosteroids is common and should not mitigate against the diagnosis. Histopathological confirmation should ideally be made before starting therapy, as this may obscure or delay the correct diagnosis. Although PCNSL is rare, it must be considered in all patients with brain stem syndromes, and in all patients 50 years or older with contrast enhancing focal lesions. 相似文献
42.
Cutaneous sporotrichosis is clinically divided into two main types: lymphocutaneous and fixed plaque type. Our report represents an unusual case with both types simultaneously. Fluconazole 150 mg once weekly was used as the treatment. The fixed type lesions responded very well and were healed after 4 months, but the lymphocutaneous lesions were not controlled even after 6 months of the treatment. 相似文献
43.
44.
G Shams M W Harrold B Grazyl D D Miller D R Feller 《European journal of pharmacology》1990,184(2-3):251-256
The beta 1- and beta 2-adrenoceptor agonist properties of trimetoquinol (TMQ, I) and N-benzyl ring substituted TMQ analogues (II, 4'-methylbenzylTMQ; III, 4'-chloro-benzylTMQ; IV, 4'-methoxybenzylTMQ; V, 4'-nitrobenzylTMQ; VI, 3',4'-dichlorobenzylTMQ; and VII, 4'-aminobenzylTMQ) were studied in guinea pig atria and trachea. All compounds gave concentration-dependent responses in atria and trachea, and the rank order of beta-adrenoceptor agonist potency was I greater than VII greater than II greater than V greater than IV greater than VI greater than III and I greater than VII greater than IV = VI greater than V greater than III greater than II, respectively. Whereas the N-benzyl substitution reduced potency for beta-agonist activity, the beta 2/beta 1-selectivity ratio was enhanced by addition of groups to the N-benzyl ring, and the rank order of beta 2-selectivity was VI (10-fold) greater than III (8-fold) = IV (8-fold) greater than VII (3-fold) greater than V = I greater than II. The results show that varying the nature of substituents on the N-benzyl ring of TMQ produces compounds which retain greater beta 2-selectivity. 相似文献
45.
BACKGROUND: There have been many studies in recent years concerning the role of nitric oxide (NO) in acute renal failure (ARF). In this study, the effects of the inhibition or the induction of NO synthase (NOS) on gentamicin-induced ARF was investigated in isolated perfused rat kidneys. METHODS: Kidneys from male Sprague-Dawley rats were perfused in situ for 90 min. Perfusion was conducted in the presence of inulin (60 mg/dL in perfusion buffer) as a glomerular filtration rate (GFR) marker. Six groups (total: 42 rats) were studied: group 1, controls with no treatment; group 2, L-arginine (2 mM in perfusate); group 3, L-nitro-arginine-methyl ester (L-NAME, 0.1 mM in perfusate); group 4, gentamicin (GM, 0.5 mg/mL in perfusate); group 5, GM + L-arginine (same dose as groups 2 and 4) and; group 6, GM + L-NAME (same dose as groups 3 and 4). Cell injury was assessed by measuring N-acetyl-beta-D-glucosaminidase (NAG), lactate dehydrogenase (LDH) and alkaline phosphatase (ALP) activity in urine. RESULTS: L-arginine prevented, whereas L-NAME enhanced, GM-induced enzyme release and GFR reduction. Histological studies showed that GM-treated kidneys had clear signs of tubular damage and this damage was increased by simultaneous L-NAME and GM administration. CONCLUSION: This study suggests that NO formation could prevent the GM-induced nephrotoxicity in this ARF model. 相似文献
46.
Although vision is considered the dominant modality, recent studies demonstrate the influence of other modalities on visual perception. For example, in the sound-induced flash illusion, two auditory stimuli cause one visual flash to be perceived as two. We report an extension of the sound-induced flash illusion to the tactile-visual domain, yielding the touch-induced flash illusion. Observers reported seeing two flashes on the majority of trials when a single flash was presented concurrently with two task-irrelevant brief tactile stimuli. Somatosensory stimulation changed the sensitivity (d') of detecting visual stimuli, which suggests that the observed effect is at least partly due to perceptual interactions. Together with other recent findings, these results challenge the notion that the processing of visual information is independent of activity in other modalities. 相似文献
47.
48.
Hyder AA Arifeen S Begum N Fishman S Wali S Baqui AH 《Injury control and safety promotion》2003,10(4):205-210
The study focuses on children less than 5 years old and explores the epidemiological profile and correlates of drowning as a challenge to child survival in Bangladesh. Two data sources from Bangladesh, a cohort of 8,070 children followed for 2 years in a rural area and a nation-wide survey conducted in 1996-97 have been used. In addition, a systematic review of the literature has been conducted spanning the past two decades for analysis of drowning in children. Seventy drowning deaths were reported in the cohort and 726 deaths were reported in the national survey. Verbal autopsy and semi-structured interviews were conducted on all deaths. Drowning accounted for 43% of deaths in the cohort and 20% of deaths in 1-4-year-old children in the national survey. Most drowning deaths were in 12-23 month old children from falling into ditches and ponds. Communities provided valuable insights on possible interventions to reduce deaths due to drowning. Drowning is a newly recognized challenge for Bangladesh. Considerable research and programmatic work is required to understand the nature of the problem and develop appropriate interventions. This paper calls on aid agencies to create opportunities for drowning research and action in their work plans for the country. 相似文献
49.
Volatile anaesthetic minimum alveolar concentration (MAC, a measure of anaesthetic requirement) increased in a time-dependent manner in rats fed a Mg2+-deficient diet. MAC values in hypomagnesemic rats were 22-30 per cent greater than those in age-matched controls at 12 and 17 days after starting the diet (p < 0.01). Noradrenergic neuronal activity, as assessed from the ratio of the concentration of 3,4-dihydroxyphenylethylene-glycol (DHPG) to that of norepinephrine (NE), decreased in the brain stem and cerebrum-cerebellum in hypomagnesemic rats owing to an increase in NE concentration in both regions of the brain (p < 0.025). We conclude that prolonged hypomagnesemia (> or = 12 days) increases volatile anaesthetic MAC in the rat. The concomitant decrease in the ratio of DHPG/NE suggests that this increase in MAC cannot be attributed to an increase in noradrenergic neuronal activity in brain. 相似文献
50.
A. Minetti M. Shams Eldin I. Defourny G. Harczi 《Tropical medicine & international health : TM & IH》2009,14(10):1210-1214
Objectives To describe the implementation of the WHO2006 growth standards in a therapeutic feeding programme.
Methods Using programme monitoring data from 21 769 children 6–59 months admitted to the Médecins Sans Frontières therapeutic feeding programme during 2007, we compared characteristics at admission, type of care and outcomes for children admitted before and after the shift to the WHO2006 standards. Admission criteria were bipedal oedema, MUAC <110 mm, or weight-for-height (WFH) of <-70% of the median (NCHS) before mid-May 2007, and WFH <-3 z score (WHO2006 ) after mid-May 2007.
Results Children admitted with the WHO2006 standards were more likely to be younger, with a higher proportion of males, and less malnourished (mean WFH -3.6 z score vs. mean WFH -4.6 z score). They were less likely to require hospitalization or intensive care (28.4% vs. 77%; 12.8% vs. 36.5%) and more likely to be treated exclusively on an outpatient basis (71.6% vs. 23%). Finally, they experienced better outcomes (cure rate: 89% vs. 71.7%, death rate: 2.7% vs. 6.4%, default rate: 6.7% vs. 12.3%).
Conclusions In this programme, the WHO2006 standards identify a larger number of malnourished children at an earlier stage of disease facilitating their treatment success. 相似文献
Methods Using programme monitoring data from 21 769 children 6–59 months admitted to the Médecins Sans Frontières therapeutic feeding programme during 2007, we compared characteristics at admission, type of care and outcomes for children admitted before and after the shift to the WHO
Results Children admitted with the WHO
Conclusions In this programme, the WHO