全文获取类型
收费全文 | 893篇 |
免费 | 95篇 |
国内免费 | 2篇 |
专业分类
耳鼻咽喉 | 9篇 |
儿科学 | 34篇 |
妇产科学 | 24篇 |
基础医学 | 126篇 |
口腔科学 | 13篇 |
临床医学 | 124篇 |
内科学 | 135篇 |
皮肤病学 | 13篇 |
神经病学 | 62篇 |
特种医学 | 43篇 |
外科学 | 108篇 |
综合类 | 22篇 |
一般理论 | 1篇 |
预防医学 | 124篇 |
眼科学 | 11篇 |
药学 | 96篇 |
中国医学 | 6篇 |
肿瘤学 | 39篇 |
出版年
2023年 | 8篇 |
2022年 | 17篇 |
2021年 | 23篇 |
2020年 | 18篇 |
2019年 | 30篇 |
2018年 | 32篇 |
2017年 | 16篇 |
2016年 | 22篇 |
2015年 | 26篇 |
2014年 | 34篇 |
2013年 | 42篇 |
2012年 | 60篇 |
2011年 | 45篇 |
2010年 | 23篇 |
2009年 | 17篇 |
2008年 | 48篇 |
2007年 | 63篇 |
2006年 | 38篇 |
2005年 | 35篇 |
2004年 | 33篇 |
2003年 | 26篇 |
2002年 | 24篇 |
2001年 | 24篇 |
2000年 | 26篇 |
1999年 | 28篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 5篇 |
1994年 | 7篇 |
1993年 | 8篇 |
1992年 | 14篇 |
1991年 | 15篇 |
1990年 | 14篇 |
1989年 | 15篇 |
1988年 | 5篇 |
1987年 | 8篇 |
1986年 | 6篇 |
1985年 | 4篇 |
1984年 | 9篇 |
1983年 | 8篇 |
1982年 | 6篇 |
1981年 | 4篇 |
1978年 | 13篇 |
1977年 | 13篇 |
1976年 | 5篇 |
1975年 | 5篇 |
1974年 | 11篇 |
1973年 | 5篇 |
1968年 | 5篇 |
1921年 | 3篇 |
排序方式: 共有990条查询结果,搜索用时 15 毫秒
1.
Single doses of primaquine did not produce methemoglobinemia in beagle bitches. Repeated daily administration for 12 days produced a gradually rising level of methemoglobin over that time period, unaccompanied by depletion of erythrocytic reduced glutathione. Primaquine was mutagenic in the Ames test in Salmonella typhimurium strain TA 1537, with or without S9, using a liquid preincubation assay. Primaquine was non-mutagenic in this assay to strains TA 1535, TA 1538, TA 98 and TA 100, regardless of the presence or absence of S9. In the standard overpour Ames test, the drug was non-mutagenic in all 5 Salmonella strains, both with and without S9 metabolic activation. 相似文献
2.
S Lori Brown Roselie A Bright Diane E Dwyer Betsy Foxman 《Journal of human lactation》2005,21(2):169-174
Breast pumps are medical devices used to express milk and maintain the milk supply. The purpose of this study was to characterize adverse events reported to the United States Food and Drug Administration (FDA) on breast pumps. Thirty-seven adverse event reports on breast pumps were identified from the Manufacturer and User Facility Device Experience database between 1992 and 2003. Four additional reports were found in the Device Experience Network database from 1992 to 1996. The most commonly reported adverse events for electric breast pumps were pain, soreness, or discomfort; the need for medical intervention; and breast tissue damage. Most frequently reported problems for manual breast pumps were breast tissue damage and infection. Contamination of breast milk during pumping was also reported. Breast pump adverse events are likely underreported to the FDA. Reporting adverse events is important for improving the design and manufacture of breast pumps and subsequently decreasing adverse events. 相似文献
3.
J E Bright A C Woodman T C Marrs S G Wood 《Xenobiotica; the fate of foreign compounds in biological systems》1987,17(1):79-83
A methaemoglobin former, 4-aminopropiophenone (p-aminopropiophenone, PAPP), which is active only after metabolic activation in vivo, exhibits a sex difference in male Beagle dogs and bitches. Bitches produced more methaemoglobin for a given dose of PAPP than male dogs. The probable reason for this difference was a lower rate of N-hydroxylation in male dogs. 相似文献
4.
1 The standard drug for the treatment of arsenic poisoning is BAL (dimercaprol). BAL possesses marked side-effects and a low safety ratio, drawbacks which new BAL analogues, DMPS and DMSA, do not possess. 2 The efficacy of three chelating agents, BAL, DMPS and DMSA, has been evaluated as a treatment for systemic organic arsenic poisoning, induced by intravenous dichloro(2-chlorovinyl)arsine (lewisite) administration to rabbits. Equimolar dosing schedules were used based upon realistic doses for the most toxic agent, BAL. 3 It was concluded that all three dimercapto chelating agents provided significant protection against the lethal systemic effects of lewisite, and, under the test conditions reported here, there was no significant difference between them in therapeutic efficacy. 4 The cause of mortality following intravenous lewisite in treated and untreated rabbits was pulmonary damage. 5 It is considered that DMPS and DMSA are worthy of further study as replacements for BAL in the treatment of systemic poisoning by lewisite. 相似文献
5.
Jane Maienschein James L. W. West Betty Bright 《Pediatric nephrology (Berlin, Germany)》2004,19(12):1437-1438
6.
Salt appetite and lesions of the ventral part of the ventral median preoptic nucleus 总被引:3,自引:0,他引:3
Angiotensin receptors in the most ventral part of the ventral median preoptic nucleus (VVMnPO) or organum vasculosum laminae terminalis appear to be important for salt appetite to angiotensin in rats. If so, then small lesions of this region should reduce salt appetite that is dependent on angiotensin. In separate experiments, the lesion greatly reduced salt appetite after treatments with chronic oral captopril or sodium depletion. On the other hand, the VVMnPO lesion actually enhanced salt appetite to deoxycorticosterone acetate. The lesion did not affect water intake to water deprivation, combined food-water deprivation, isoproterenol, or hypertonic saline, and basal plasma osmolality and sodium values were normal. These experiments suggest that VVMnPO lesions selectively affect angiotensin-induced salt appetite without producing the gross hydrational deficits that occur with larger lesions of the ventral forebrain. 相似文献
7.
Pincivero DM Coelho AJ Campy RM Salfetnikov Y Bright A 《European journal of applied physiology》2002,87(4-5):448-455
The purpose of this study was to examine the effect of voluntary contraction efforts on the median frequency (f
med) of the electromyogram (EMG) recorded from the quadriceps femoris muscle in healthy men and women. A group of 30 healthy
volunteers (15 men, 15 women) were assessed for EMG activity of the vastus medialis (VM), vastus lateralis (VL), and rectus
femoris (RF) muscles during isometric contractions with the knee at 60° flexion. Subjects performed a series of 5 s maximal
voluntary isometric contractions that anchored the perceptual range with a "10" on a 10-point scale. Sub-maximal isometric
contractions were then separately performed at the following perceived effort levels on the 10-point scale: 1, 2, 3, 4, 5,
6, 7, 8 and 9, in a random order. Subjects were instructed to maintain the contraction at each perceived level of effort for
5 s. The f
med of the three muscles was assessed using a power spectrum analysis performed over 11 consecutive, 512 ms, epochs overlapping
each other by half their length during the middle 3 s of each contraction. The f
med for each of the 11 epochs was then determined for each muscle, followed by calculation of the means and normalized coefficients
of variation [(standard deviation/mean)×100%] for each contraction. The results demonstrated that the mean f
med of VL was significantly greater than those of the other two muscles, and that f
med of RF was significantly greater than that of VM. The VL muscle demonstrated a significant increase in mean f
med across the contraction efforts, compared to the VM and RF muscles that displayed a significant decrease. The men displayed
significantly higher f
med values for the VM muscle than did the women, as well as showing a significantly greater increase across the contraction efforts
for the VL muscle. The variability of f
med was shown to be significantly higher for the VM muscle, compared to the VL and RF muscles. The findings of this study suggest
that the f
med statistic is most sensitive to contraction intensity efforts for the VL muscle, and that men display significantly higher
values for the VL and VM muscles, compared to women.
Electronic Publication 相似文献
8.
Studies on the role of HLA-DR in macrophage-T cell interactions 总被引:1,自引:0,他引:1
The purpose of this paper is to illustrate the difficulties we have encountered in attempting to analyse the role of HLA-DR in the antigen-dependent co-operation between macrophages and T cells which leads to a T-cell proliferative response. We have adopted the two most commonly used approaches; attempted inhibition by anti-HLA-DR antisera and study of co-operation between cells of unrelated individuals, and have found both methods unsatisfactory. With the first method we found that anti-HLA antisera could inhibit proliferative responses in a non-specific manner. Both anti-HLA-A, B and anti-HLA-DR antisera could inhibit and this inhibition was largely Fc-dependent. Using pepsin-digested antisera we have no evidence for a unique role for HLA-DR in these proliferative responses. The second method, study of co-operation between cells of unrelated individuals, proved extremely difficult to analyse because of the background allogeneic reaction. Whether cells of two individuals appeared to co-operate to give an antigen-specific response depended on the number of cells used and the calculations applied to the data. However, it was clearly possible to demonstrate co-operation between DR different individuals. 相似文献
9.
Tyler LK Bright P Dick E Tavares P Pilgrim L Fletcher P Greer M Moss H 《Cognitive neuropsychology》2003,20(3):541-559
A key issue in cognitive neuroscience concerns the neural representation of conceptual knowledge. Currently, debate focuses around the issue of whether there are neural regions specialised for the processing of specific semantic attributes or categories, or whether concepts are represented in an undifferentiated neural system. Neuropsychological studies of patients with selective semantic deficits and previous neuroimaging studies do not unequivocally support either account. We carried out a PET study to determine whether there is any regional specialisation for the processing of concepts from different semantic categories using picture stimuli and a semantic categorisation task. We found robust activation of a large semantic network extending from left inferior frontal cortex into the inferior temporal lobe and including occipital cortex and the fusiform gyrus. The only category effect that we found was additional activation for animals in the right occipital cortex, which we interpret as being due to the extra visual processing demands required in order to differentiate one animal from another. We also carried out analyses in specific cortical regions that have been claimed to be preferentially activated for various categories, but found no evidence of any differential activation as a function of category. We interpret these data within the framework of cognitive accounts in which conceptual knowledge is represented within a nondifferentiated distributed system. 相似文献
10.