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Belfield EJ Gan X Mithani A Brown C Jiang C Franklin K Alvey E Wibowo A Jung M Bailey K Kalwani S Ragoussis J Mott R Harberd NP 《Genome research》2012,22(7):1306-1315
Ionizing radiation has long been known to induce heritable mutagenic change in DNA sequence. However, the genome-wide effect of radiation is not well understood. Here we report the molecular properties and frequency of mutations in phenotypically selected mutant lines isolated following exposure of the genetic model flowering plant Arabidopsis thaliana to fast neutrons (FNs). Previous studies suggested that FNs predominantly induce deletions longer than a kilobase in A. thaliana. However, we found a higher frequency of single base substitution than deletion mutations. While the overall frequency and molecular spectrum of fast-neutron (FN)-induced single base substitutions differed substantially from those of "background" mutations arising spontaneously in laboratory-grown plants, G:C>A:T transitions were favored in both. We found that FN-induced G:C>A:T transitions were concentrated at pyrimidine dinucleotide sites, suggesting that FNs promote the formation of mutational covalent linkages between adjacent pyrimidine residues. In addition, we found that FNs induced more single base than large deletions, and that these single base deletions were possibly caused by replication slippage. Our observations provide an initial picture of the genome-wide molecular profile of mutations induced in A. thaliana by FN irradiation and are particularly informative of the nature and extent of genome-wide mutation in lines selected on the basis of mutant phenotypes from FN-mutagenized A. thaliana populations. 相似文献
94.
Ramaswamy S Schornack PA Smelko AG Boronyak SM Ivanova J Mayer JE Sacks MS 《NMR in biomedicine》2012,25(3):410-417
The intimal and medial linings of the pulmonary artery consist largely of vascular endothelial cells (VECs) and vascular smooth muscle cells (VSMCs), respectively. The migration of these cell types to a potential tissue-engineered pulmonary valve (TEPV) implant process is therefore of interest in understanding the valve remodeling process. Visualization and cell tracking by MRI, which employs hypointense contrast achievable through the use of superparamagnetic iron oxide (SPIO) microparticles to label cells, provides a method in which this can be studied. We investigated the SPIO labeling efficiency of human VECs and VSMCs, and used two- and three-dimensional gradient echo sequences to track the migration of these cells in agar gel constructs. Protamine sulfate (4.5 μg/mL) was used to enhance SPIO uptake and was found to have no influence on cell viability or proliferation. MRI experiments were initially performed using a 9.4-T scanner. The results demonstrated that the spatial positions of hypointense spots were relatively unchanged over 12 days. Subsequent MR experiments performed at 7 T demonstrated that three-dimensional imaging provided the best spatial resolution to assess cell fate. R(2)* maps were bright in SPIO cell-encapsulated gels in comparison with unlabeled counterparts. Signal voids were ruled out as hypointense regions owing to the smooth exponential decay of T(2)* in these voxels. As a next step, we intend to use the SPIO cell labeling and MR protocols established in this study to assess whether hemodynamic stresses will alter the vascular cell migratory patterns. These studies will shed light on the mechanisms of vascular remodeling after TEPV implantation. 相似文献
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Sharan D Parijat P Sasidharan AP Ranganathan R Mohandoss M Jose J 《Journal of occupational rehabilitation》2011,21(4):520-525
Introduction Work-related musculoskeletal disorders are common in computer professionals. Workstyle may be one of the risk factors in
the development of musculoskeletal discomfort. The objective of this retrospective study was to examine the prevalence of
adverse workstyle in computer professionals from India and to evaluate if workstyle factors were predictors of pain and loss
of productivity. Methods Office workers from various information technology (IT) companies in India responded to the short-form workstyle questionnaire
and pain questionnaire. Correlation analyses were conducted to examine the associations between different variables followed
by a multivariate logistic regression to understand the unique predictors of pain and loss of productivity. Results 4,500 participants responded to the workstyle and pain questionnaire. 22% of participants were reported to have a high risk of an adverse workstyle. 63% of participants reported pain symptoms.
Social reactivity, lack of breaks, and deadlines/pressure subscales of workstyle questionnaire were significantly correlated
with pain and loss of productivity. Regression analyses revealed that workstyle factors and duration of computer use per day
were significant predictors of pain. Conclusion Workstyle seems to be a mediating factor for musculoskeletal pain, discomfort, and loss of productivity. Based on the study
findings, it is recommended that intervention efforts directed towards prevention of musculoskeletal disorders should focus
on psychosocial work factors such adverse workstyle in addition to biomechanical risk factors. 相似文献
97.
BACKGROUND: Discrepancy between efficacy of prophylactic lithium and its effectiveness in ordinary clinical practice necessitates long-term follow-up data from specialised lithium clinics. Also, role of psychosocial factors in influencing the outcome is unclear. METHODS: One hundred and eighteen patients of bipolar affective disorder attending a lithium clinic were followed-up for approximately 11 years (range 2-27 years). Demographic and clinical data, measures of social support and psychosocial stress were obtained at the intake in 1989-1990. Study design combined retrospective chart-review (till the time of intake) with prospective follow-up till July 1995. RESULTS: On lithium, the patients had a mean of 0.43 relapses per year (manic, 0.26; depressive, 0.17) which was significantly less (p < 0.01) than the pre-lithium episode frequency. The figure for entirely relapse-free patients was 24%, and 62% had relapses up to one episode per year (median = 0.3 per year). Fifty-eight (49%) patients were good responders to lithium (relapses < or = 0.30 per year). In comparison to good responders, partial/poor responders had a significantly greater number of pre-lithium depressive episodes, poor lithium compliance, more psychosocial stress and lower social support at intake. These variables correlated well with relapses and explained 32% of the variance of the data. CONCLUSIONS: Lithium had a definite prophylactic effect on long-term outcome. Social support and stressful life events are significant correlates of response to lithium. CLINICAL IMPLICATIONS: Lithium prophylaxis of bipolar affective disorders seems justified though psychosocial factors appear to modulate its effectiveness. LIMITATIONS: Other psychotropic medications were used during relapse and the assessment of psychosocial factors was cross-sectional. 相似文献
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S. Thangminlal Vaiphei Joshua Keppen Saibadaiahun Nongrum R.C. Chaubey L. Kma R.N. Sharan 《Journal of radiation research》2015,56(1):177-185
In gene expression studies, it is critical to normalize data using a stably expressed endogenous control gene in order to obtain accurate and reliable results. However, we currently do not have a universally applied endogenous control gene for normalization of data for gene expression studies, particularly those involving 60Co γ-ray-exposed human blood samples. In this study, a comparative assessment of the gene expression of six widely used housekeeping endogenous control genes, namely 18S, ACTB, B2M, GAPDH, MT-ATP6 and CDKN1A, was undertaken for a range of 60Co γ-ray doses (0.5, 1.0, 2.0 and 4.0 Gy) at 8.4 Gy min−1 at 0 and 24 h post-irradiation time intervals. Using the NormFinder algorithm, real-time PCR data obtained from six individuals (three males and three females) were analyzed with respect to the threshold cycle (Ct) value and abundance, ΔCt pair-wise comparison, intra- and inter-group variability assessments, etc. GAPDH, either alone or in combination with 18S, was found to be the most suitable endogenous control gene and should be used in gene expression studies, especially those involving qPCR of γ-ray-exposed human blood samples. 相似文献
100.
Deepak Pinto K. Manjunath Amarnath D. Savur Naufal Rizwan Ahme Sharan Mally V. Ramya 《中华创伤杂志(英文版)》2019,22(5):270-273
Purpose: Open tibia fracture is prone to infection, consequently causing significant morbidity and increasing the hospital stay, occupational loss and onset of chronic osteomyelitis. Intramedullary nailing is one choice for treating tibia shaft fractures. To improve the delivery of antibiotics at the tissue-implant interface, many methods have been proposed as a part of prophylaxis against infection. This study was conducted to study the role of gentamicin-impregnated intramedullary interlocking (IMIL) nail in the prevention of infection in Gustilo type I and II open tibia fractures and to compare the results with
regular intramedullary nail.
Methods: The study included 28 patients with open tibia fractures (Gustilo type 1 or type 2); of them 14 underwent regular IMIL nailing and the other 14 were treated with gentamicin-coated nailing. Randomization was done by alternate allocation of the patients. Follow-up was done postoperatively (day 1), 1 week, 6 weeks, and 6 months for bone union, erythrocyte sedimentation rate (ESR), hemo globin and C-reactive protein (CRP). Statistical significance was tested using unpaired t-test. A p value less than 0.05 was considered significant.
Results: There were 4 cases of infection in controls (regular IMIL nail) and no infection among patients treated with gentamicin-coated nail during the follow up (X2 = 4.66, p = 0.031). At 6 months post operatively, CRP (p = 0.031), ESR (p = 0.046) and hemoglobin level (p = 0.016) showed significant dif ference between two groups. The bone healing rate was better with gentamicin-coated nail in comparison to regular IMIL nail at 6 months follow-up (p = 0.016).
Conclusion: Gentamicin-coated IMIL nail has a positive role in preventing infection in Gustilo type I and II open tibia fractures. 相似文献