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In countries that have not implemented universal antiretroviral treatment (ART), loss to follow-up (LTFU) during pre-ART care remains a problem. We conducted semi-structured interviews with 41 HIV-infected persons who were LTFU during pre-ART care from a prospective cohort of persons newly diagnosed with HIV infection in Freetown, Sierra Leone, in 2012–2013. Interviews determined whether the participant disengaged or transferred care and explored the reasons for being LTFU. Of the 41 participants, 34 (83%) disengaged from care. For persons who disengaged from care, socioeconomic barriers emerged as a dominant theme in both ART-eligible and -ineligible groups while psychosocial barriers emerged as a dominant theme in the ART-ineligible group. Structural barriers emerged as a dominant theme for participants who transferred care. Interventions designed to address socioeconomic and psychosocial barriers may help reduce disengagement from pre-ART care.  相似文献   
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Connections between the thalamus and cortex develop rapidly before birth, and aberrant cerebral maturation during this period may underlie a number of neurodevelopmental disorders. To define functional thalamocortical connectivity at the normal time of birth, we used functional MRI (fMRI) to measure blood oxygen level-dependent (BOLD) signals in 66 infants, 47 of whom were at high risk of neurocognitive impairment because of birth before 33 wk of gestation and 19 of whom were term infants. We segmented the thalamus based on correlation with functionally defined cortical components using independent component analysis (ICA) and seed-based correlations. After parcellating the cortex using ICA and segmenting the thalamus based on dominant connections with cortical parcellations, we observed a near-facsimile of the adult functional parcellation. Additional analysis revealed that BOLD signal in heteromodal association cortex typically had more widespread and overlapping thalamic representations than primary sensory cortex. Notably, more extreme prematurity was associated with increased functional connectivity between thalamus and lateral primary sensory cortex but reduced connectivity between thalamus and cortex in the prefrontal, insular and anterior cingulate regions. This work suggests that, in early infancy, functional integration through thalamocortical connections depends on significant functional overlap in the topographic organization of the thalamus and that the experience of premature extrauterine life modulates network development, altering the maturation of networks thought to support salience, executive, integrative, and cognitive functions.The formation of topographically organized neural connections between cerebral cortex and thalamus is necessary for normal cortical morphogenesis (1), and development of these connections requires thalamocortical projections to synapse transiently in the temporary cortical subplate before penetrating the cortical plate (24). In humans, the subplate is at maximal extent in the last trimester of gestation (5), a time of rapid growth for thalamocortical fibers and the cortical dendritic tree, particularly in heteromodal cortex (6, 7). This process has been shown to be disrupted by preterm birth (8). Premature delivery is associated with increased risk of neurocognitive impairment, and it is widely hypothesized that abnormal development of brain structure during this period is the cause of these problems and may also underlie the development of autistic spectrum disorders and attention deficit disorders in genetically predisposed individuals.During the last trimester of pregnancy, functional MRI (fMRI) detects the emergence of coordinated, spontaneous fluctuations in the blood oxygen level-dependent (BOLD) signals, which are closely linked with the development of electroencephalographic activity (911) and develop into a near-facsimile of the mature adult resting-state network architecture by the normal age of birth at 38–42 wk gestational age (12). However, little is known about the growth of functional connectivity between the thalamus and cortex during this period.Anatomical studies in animals and postmortem adult human subjects have defined the thalamic microstructure and described a corticotopic parcellation of the thalamus with precise connectivity to specific cortical regions (13, 14). Diffusion tensor imaging studies have described a similar pattern of structural thalamocortical connectivity (15, 16), with evidence in adults that some thalamocortical circuits share common thalamic territory, giving the potential for integrative functions (17). Functional connectivity MRI analysis between the thalamus and the cortex has also shown corticotopic organization in the thalamus (18, 19).It is not known, however, when this thalamocortical mapping develops or how it might be disrupted during development. We, therefore, used connectivity fMRI to address a series of questions. First, is the pattern of dominant thalamocortical connectivity at the time of normal birth already similar to the mature adult pattern? Second, in addition to the dominant thalamocortical correlations, is there a pattern of overlapping cortical representations in the neonatal thalamus that might reflect developing integration of functional cortical regions? Third, does the experience of preterm delivery and premature extrauterine life affect the development of thalamocortical connectivity, and is the effect more marked in rapidly developing heteromodal cortex than in more mature primary cortex?  相似文献   
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Purpose

Technological advances in recent decades have led to the availability of new modes to administer patient-reported outcomes (PROs). To aid selecting optimal modes of administration (MOA), we undertook a systematic review to determine whether differences in bias (both size and direction) exist among modes.

Methods

We searched five electronic databases from 2004 (date of last comprehensive review on this topic) to April 2014, cross-referenced and searched reference lists. Studies that compared two or more MOA for a health-related PRO measure in adult samples were included. Two reviewers independently applied inclusion and quality criteria and extracted findings. Meta-analyses and meta-regressions were conducted using random-effects models.

Results

Of 5100 papers screened, 222 were considered potentially relevant and 56 met eligibility criteria. No evidence of bias was found for: (1) paper versus electronic self-complete; and (2) self-complete versus assisted MOA. Heterogeneity for paper versus electronic comparison was explained by type of construct (i.e. physical vs. psychological). Heterogeneity for self-completion versus assisted modes was in part explained by setting (clinic vs. home); the largest bias was introduced when assisted completion occurred in the clinic and follow-up was by self-completion (either electronic or paper) in the home.

Conclusions

Self-complete paper and electronic MOA can be used interchangeably for research in clinic and home settings. Self-completion and assisted completion produce equivalent scores overall, although heterogeneity may be induced by setting. These results support the use of mixed MOAs within a research study, which may be a useful strategy for reducing missing PRO data.
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We sought to evaluate the feasibility of conducting a randomized trial to evaluate the efficacy of a preschool/kindergarten curriculum intervention designed to increase 4-year-old children's knowledge of healthy eating, active play and the sustainability consequences of their food and toy choices. Ninety intervention and 65 control parent/child dyads were recruited. We assessed the study feasibility by examining recruitment and participation, completion of data collection, realization of the intervention and early childhood educators’ experiences of implementing the study protocol; our findings suggest the intervention was feasible to deliver. In addition, children's sustainability awareness of non-compostable and recyclable items increased. Children in the intervention group significantly reduced their sugary drink consumption and increased their vegetable intake at follow-up compared to control. We conclude with recommendations for revisions to the child interview and parent questionnaire delivery to ensure the roll out of the randomized trial is conducted efficiently and rigorously.  相似文献   
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Individuals with sudden unilateral deafness offer a unique opportunity to study plasticity of the binaural auditory system in adult humans. Stimulation of the intact ear results in increased activity in the auditory cortex. However, there are no reports of changes at sub-cortical levels in humans. Therefore, the aim of the present study was to investigate changes in sub-cortical activity immediately before and after the onset of surgically induced unilateral deafness in adult humans. Click-evoked auditory brainstem responses (ABRs) to stimulation of the healthy ear were recorded from ten adults during the course of translabyrinthine surgery for the removal of a unilateral acoustic neuroma. This surgical technique always results in abrupt deafferentation of the affected ear. The results revealed a rapid (within minutes) reduction in latency of wave V (mean pre = 6.55 ms; mean post = 6.15 ms; p < 0.001). A latency reduction was also observed for wave III (mean pre = 4.40 ms; mean post = 4.13 ms; p < 0.001). These reductions in response latency are consistent with functional changes including disinhibition or/and more rapid intra-cellular signalling affecting binaurally sensitive neurons in the central auditory system. The results are highly relevant for improved understanding of putative physiological mechanisms underlying perceptual disorders such as tinnitus and hyperacusis.  相似文献   
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