全文获取类型
收费全文 | 6238篇 |
免费 | 394篇 |
国内免费 | 13篇 |
专业分类
耳鼻咽喉 | 67篇 |
儿科学 | 207篇 |
妇产科学 | 128篇 |
基础医学 | 723篇 |
口腔科学 | 75篇 |
临床医学 | 768篇 |
内科学 | 1062篇 |
皮肤病学 | 72篇 |
神经病学 | 734篇 |
特种医学 | 238篇 |
外科学 | 667篇 |
综合类 | 240篇 |
一般理论 | 6篇 |
预防医学 | 756篇 |
眼科学 | 139篇 |
药学 | 494篇 |
1篇 | |
中国医学 | 1篇 |
肿瘤学 | 267篇 |
出版年
2023年 | 52篇 |
2022年 | 126篇 |
2021年 | 259篇 |
2020年 | 100篇 |
2019年 | 169篇 |
2018年 | 209篇 |
2017年 | 140篇 |
2016年 | 164篇 |
2015年 | 150篇 |
2014年 | 198篇 |
2013年 | 304篇 |
2012年 | 374篇 |
2011年 | 363篇 |
2010年 | 229篇 |
2009年 | 216篇 |
2008年 | 274篇 |
2007年 | 299篇 |
2006年 | 276篇 |
2005年 | 272篇 |
2004年 | 212篇 |
2003年 | 207篇 |
2002年 | 196篇 |
2001年 | 115篇 |
2000年 | 148篇 |
1999年 | 140篇 |
1998年 | 63篇 |
1997年 | 53篇 |
1996年 | 30篇 |
1995年 | 34篇 |
1994年 | 48篇 |
1993年 | 36篇 |
1992年 | 84篇 |
1991年 | 68篇 |
1990年 | 66篇 |
1989年 | 69篇 |
1988年 | 51篇 |
1987年 | 61篇 |
1986年 | 68篇 |
1985年 | 57篇 |
1984年 | 55篇 |
1983年 | 40篇 |
1982年 | 52篇 |
1981年 | 31篇 |
1980年 | 36篇 |
1979年 | 33篇 |
1978年 | 27篇 |
1977年 | 28篇 |
1976年 | 26篇 |
1975年 | 26篇 |
1974年 | 29篇 |
排序方式: 共有6645条查询结果,搜索用时 15 毫秒
71.
Kirsten Barnicot Jennie Parker Sarah Kalwarowsky Eloise Stevens Jane Iles Paul Ramchandani Mike Crawford 《Psychology and psychotherapy》2023,96(2):480-503
Objectives
We explored mothers' and clinicians' experiences of a video feedback intervention adapted for perinatal ‘personality disorder’ (VIPP-PMH) and the acceptability of a randomised controlled trial (RCT) examining its effectiveness.Design
In-depth qualitative interviews with participants from a two-phase feasibility study of the VIPP-PMH intervention. Participants were mothers experiencing enduring difficulties in managing emotions and relationships, consistent with a ‘personality disorder’, and their 6- to 36-month-old children.Methods
Forty-four qualitative interviews were conducted, including all nine mothers receiving VIPP-PMH during the pilot phase, 25 of the 34 mothers participating in the RCT (14 allocated to the VIPP-PMH arm and 9 from the control arm), 11 of the 12 clinicians delivering VIPP-PMH and one researcher. Interview data were thematically analysed.Results
Mothers described feeling motivated to take part in the research and understood the need for randomisation. Research visits were largely experienced positively, with some suggestions for improvement in questionnaire timing and accessibility. Almost all mothers initially felt anxious about being filmed, but reported positive experiences of the intervention, particularly valuing its non-judgemental, positive and child-focussed nature, their supportive relationship with the therapist and the insights they gained on their child.Conclusions
The findings indicate the likely feasibility and acceptability of undertaking a future definitive RCT of the VIPP-PMH intervention in this population. In designing a future trial, a positive and non-judgemental therapeutic relationship will be important to allay mothers' anxieties about being filmed, and careful consideration should be given to the timing and accessibility of questionnaires used. 相似文献72.
Some states have adopted Medicaid reimbursement systems that pay nursing homes according to patient type. These case-mix adjusted reimbursements are intended in part to eliminate the incentive in prospective systems to exclude less profitable patients. This study estimates the marginal costs of different patient types under Minnesota's case-mix system and compares them to their corresponding reimbursements. We find that estimated costs do not match reimbursement rates, again making some patient types less profitable than others. Further, in confirmation of our estimates, we find that the percentage change in patient days between 1986 and 1990 is explained by our profitability estimates. 相似文献
73.
G T Gerhard M R Malinow T G DeLoughery A J Evans G Sexton S L Connor R C Wander W E Connor 《The American journal of clinical nutrition》1999,70(2):252-260
BACKGROUND: Premenopausal black women have a greater rate of coronary artery disease (CAD) than do premenopausal white women. Plasma total homocysteine concentrations, a risk factor for CAD, have not been reported in premenopausal black women. OBJECTIVE: The purpose of this study was to compare plasma total homocysteine, folate, and vitamin B-12 concentrations in premenopausal black and white women. DESIGN: Eighty-nine black and 90 white, healthy, premenopausal women living in Portland, OR, were recruited. Dietary histories were obtained by using the Diet Habit Survey, a 40-item eating-behavior questionnaire. Plasma concentrations of total homocysteine, folate, and vitamin B-12 were measured. RESULTS: Black women had higher plasma total homocysteine (8.32 compared with 7.60 micromol/L;P = 0. 013), lower plasma folate (6.62 compared with 9.88 nmol/L;P < 0. 0001), and higher vitamin B-12 (355 compared with 283 pmol/L;P < 0. 001) concentrations than white women. White women had a greater rate of daily multivitamin supplement use (42.4% compared with 24.7%;P = 0.019) and ate more ready-to-eat cereal than did black women. After adjustment for multivitamin use and intake of ready-to-eat cereal, plasma total homocysteine concentrations did not differ significantly, but plasma folate remained significantly lower in the black women. None of the black women but 12.3% of the white women (P = 0.013) were homozygous for the cytosine to thymidine mutation at nucleotide 677 in the methylenetetrahydrofolate reductase gene. CONCLUSIONS: Black women had higher plasma total homocysteine and lower plasma folate concentrations than white women, largely because of lifestyle factors, which may contribute to the greater rate of CAD in premenopausal black than in white women. 相似文献
74.
Dredge K Connor TJ Kelly JP Leonard BE 《International journal of immunopharmacology》1999,21(10):663-673
Tricyclic antidepressants (TCAs) of which imipramine is one, are commonly used in the treatment of depressive disorders and other forms of psychiatric illness. There have been many reports regarding the suppressive effects of TCAs on immune function. However, information is still limited regarding the effects of TCAs on the immune system, as many of the studies conducted to date have concentrated on in vitro exposure to such drugs, or ex vivo measures of immunity following drug administration. Thus in the present investigation, an in vivo challenge with bacterial lipopolysaccharide (LPS) (100 microg/kg; i.p.) was used to assess immunocompetence following administration of a single high dose of the TCA, imipramine (100 mg/kg, p.o.). The results demonstrated that imipramine pretreatment inhibits LPS-induced increases in serum concentrations of the proinflammatory cytokine, tumor necrosis factor (TNF)-alpha both 3 and 6 h, following administration. However, LPS-induced interleukin (IL)-1beta secretion was not significantly altered following imipramine treatment at either of the timepoints examined. In addition, serum concentrations of corticosterone and the antiinflammatory cytokine IL-10 were measured, and imipramine treatment failed to alter either basal, or LPS-induced increases in these immunosuppressive agents. In conclusion, although IL-1beta and TNF-alpha are both macrophage-derived proinflammatory cytokines, the present study demonstrates a differential sensitivity of these cytokines to the suppressive effects of the TCA imipramine. Furthermore, the suppressive effects of imipramine on LPS-induced TNF-alpha secretion could not be attributed to either increased glucocorticoid levels, or increased secretion of the antiinflammatory cytokine IL-10. The relevance of these findings to antidepressant-induced immunotoxicity are discussed. 相似文献
75.
76.
Malecki EA Cook BM Devenyi AG Beard JL Connor JR 《Journal of the neurological sciences》1999,170(2):112-118
Hypotransferrinemia (hpx/hpx) is a genetic defect in mice resulting in <1% of normal plasma transferrin (Tf) concentrations; heterozygotes for this mutation (+/hpx) have low circulating Tf concentrations. These mice provide a unique opportunity to examine the role of Tf in Fe and Mn transport in the brain. Twenty weanling wild-type BALB/cJ mice, 15 +/hpx mice, and 12 hpx/hpx mice of both sexes were injected i.v. with either 54MnCl(2) or 59FeCl(3) either 1 h or 1 week before killing at 12 weeks of age. Total brain counts of 54Mn and 59Fe were measured, and regional brain distributions were assessed by autoradiography. Hypotransferrinemia did not affect total brain Mn uptake. However, 1 week after i.v. injection, hpx/hpx mice had less 54Mn in forebrain structures including cerebral cortex, corpus callosum, striatum, and substantia nigra. The +/hpx mice had the highest total brain 59Fe accumulation 1 h after i.v. injection. A striking effect of regional distribution of 59Fe was noted 1 week after injection; in hpx/hpx mice, 59Fe was located primarily in choroid plexus, whereas in +/+ and +/hpx mice 59Fe was widely distributed, with relatively high amounts in cerebral cortex and cerebellum. We interpret these data to mean that Tf is necessary for the transport of Fe but not Mn across the blood-brain barrier, and that there is a Tf-independent uptake mechanism for iron in the choroid plexus. Additionally, these data suggest that endogenous synthesis of Tf is necessary for Fe transport from the choroid plexus. 相似文献
77.
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
78.
Wyke S Myles S Popay J Scott J Campbell A Girling J 《Health & social care in the community》1999,7(6):394-407
The introduction of total purchasing pilots (TPPs) into the National Health Service (NHS) gave general practitioners (GPs) significant new opportunities to take responsibility for the development of community and continuing care (CCC) services. Based on five case studies of TPPs involved in developing CCC this paper asks three questions: (1) to what extent were the TPP’s involvement in CCC informed by an awareness of CCC policy?; (2) were TPPs involved in joint commissioning to develop integrated purchasing or provision which was informed by population based needs assessment?; (3) were TPPs seeking to involve users, carers and voluntary agencies in their plans? The findings indicate that TPPs showed little awareness of national or local policy for CCC, although their project initiatives did address some of the policy issues (in particular a recognition of the need for joint working at the practice level). At the time of fieldwork, four of the case study TPPs had begun to investigate the potential for integrated purchasing, and three of them had relatively sophisticated models of both horizontally and vertically integrated provision of care. However, the TPPs developments were not based on systematic population based needs assessment. The paper concludes that there is potential for the primary care led groups proposed in the recent white papers in England, Scotland and Wales to improve integration of care both horizontally and vertically. However, they may need policy guidance and push to: encourage them to put CCC high on their agenda for action; to work with people with expertise in population based, prevention focused, needs assessment; and to find innovative ways to include users, carers and voluntary agencies. Incentives or levers (such as control over budgets) may be needed to promote joint working between staff in different agencies. 相似文献
79.
80.
Reboxetine attenuates forced swim test-induced behavioural and neurochemical alterations in the rat.
T J Connor P Kelliher A Harkin J P Kelly B E Leonard 《European journal of pharmacology》1999,379(2-3):125-133
The forced swim test is a behavioural paradigm that is predicative of antidepressant activity in rodents. Until recently, research has focused on the ability of antidepressant drugs to decrease immobility in the forced swim test paradigm, but the neurochemical sequelae induced by swim stress, or the neurochemical basis of antidepressant-induced behavioural changes have received little attention. In this regard, we have recently demonstrated that forced swim test exposure increases serotonergic activity in the amygdala, frontal cortex and hippocampus and dopamine turnover in the striatum. In addition, forced swim test-exposure activates the hypothalamic pituitary adrenal axis. The purpose of the present study was to examine the effect of treatment with the selective noradrenaline reuptake inhibitor reboxetine (3, 10 and 30 mg/kg; i.p.) on immobility and defaecation scores in the forced swim test, and on forced swim test-induced neurochemical and hypothalamic pituitary adrenal axis changes in the rat. Reboxetine treatment (10 and 30 mg/kg) significantly decreased immobility and defaecation in the forced swim test in dose dependent manner. Furthermore, reboxetine produced a dose dependent attenuation of forced swim test-induced increases in serotonin turnover in the amygdala and frontal cortex and dopamine turnover in the striatum. Reboxetine (30 mg/kg) produced a modest, but non-significant, attenuation of forced swim test-induced increases in serum corticosterone concentrations. These data demonstrate that, in addition to the behavioural activity of reboxetine in the rat forced swim test paradigm, a dose-dependent attenuation of swim stress-induced increases in serotonergic and dopaminergic activity occurred in a region specific manner. These are the first data to demonstrate that treatment with the selective noradrenaline reuptake inhibitor, reboxetine can impact on the activity of other neurotransmitter systems in response to stress. Moreover, these data further demonstrate that this paradigm is a valuable tool in studying the effect of antidepressants, on both behaviour and swim stress-related alterations in central neurotransmitter function and hypothalamic pituitary adrenal axis activity in the rat. 相似文献