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71.
Internet addiction (IA) is an emerging social and mental health issue among youths. Analysis of risk factors, as well as their interactions, is crucial for understanding the development of IA. This study investigated the relationship between recent stressful life events, personality traits, perceived family functioning and IA in 892 college students. Subjects were classified into categories (non‐addicted, mild IA or severe IA) using the Chen Internet Addiction Scale. Stressful life events, personality traits and family functioning were assessed using the Adolescent Self‐Rating Life Events Checklist, the Eysenck Personality Questionnaire, and the Family Adaptability and Cohesion Scale, respectively. The results indicated that compared with non‐addicted subjects, subjects with severe IA (9.98%) had lower family functioning, lower extraversion, higher neuroticism and psychoticism, and more stressful life events, and subjects with mild IA (11.21%) had higher neuroticism and more health and adaptation problems. Neuroticism and health and adaptation problems were potential predictors of IA. An interaction effect between psychoticism and total life stress on IA was also found. These findings highlight the role of personality traits and life stress and their interactions in college students' IA. Further research should explore the mechanisms underlying the interaction effect of psychoticism with life stress on IA. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   
72.
With low melting point, extremely low vapor pressure and non-flammability, ionic liquids have been attracting much attention from academic and industrial fields. Great efforts have been made to facilitate their applications in catalytic processes, extraction, desulfurization, gas separation, hydrogenation, electronic manufacturing, etc. To reduce the cost and environmental effects, different technologies have been proposed to recover the ionic liquids from different solutions after their application. This review is mainly focused on the recent advances of the recovery and purification of ionic liquids from solutions. Several methods for recovery of ionic liquids including distillation, extraction, adsorption, membrane separation, aqueous two-phase extraction, crystallization and external force field separation, are introduced and discussed systematically. Some industrial applications of ionic liquid recovery and purification methods are selected for discussion. Additionally, considerations on the combined design of different methods and process optimization have also been touched on to provide potential insights for future development of ionic liquid recovery and purification.

Recovery and purification of ionic liquids from solutions.  相似文献   
73.
74.
血管内皮生长因子与结肠及直肠癌淋巴结转移的关系   总被引:2,自引:0,他引:2  
目的 :研究结肠及直肠癌活体组织中血管内皮生长因子 (VEGF)、p53蛋白和增殖细胞核抗原 (PCNA)表达与淋巴结转移的关系。方法 :应用病理学诊断的方法检查淋巴结有无癌细胞转移。直肠癌组织标本做VEGF、p53蛋白和PCNA免疫组织化学染色。结果 :VEGF阳性表达的结肠及直肠癌患者淋巴结转移率为 65 .91 % (2 9/ 4 4 ) ,VEGF阴性的患者淋巴结转移率为 1 9.2 8% (1 6/ 83) ,差异有极显著意义 (χ2 =1 2 .0 777,P <0 .0 0 1 ) ;而p53及PCNA阳性表达的患者淋巴结转移和阴性表达患者的淋巴结转移之间差异无显著意义。结论 :结肠及直肠癌组织中VEGF的表达可为患者的淋巴结转移情况的判断及预后提供重要的参考依据  相似文献   
75.
Differences in susceptibility to diabetic nephropathy (DN) between mouse strains with identical levels of hyperglycemia correlate with renal levels of oxidative stress, shown previously to play a central role in the pathogenesis of DN. Susceptibility to DN appears to be genetically determined, but the critical genes have not yet been identified. Overexpression of the enzyme glyoxalase 1 (Glo1), which prevents posttranslational modification of proteins by the glycolysis-derived α-oxoaldehyde, methylglyoxal (MG), prevents hyperglycemia-induced oxidative stress in cultured cells and model organisms. In this study, we show that in nondiabetic mice, knockdown of Glo1 increases to diabetic levels both MG modification of glomerular proteins and oxidative stress, causing alterations in kidney morphology indistinguishable from those caused by diabetes. We also show that in diabetic mice, Glo1 overexpression completely prevents diabetes-induced increases in MG modification of glomerular proteins, increased oxidative stress, and the development of diabetic kidney pathology, despite unchanged levels of diabetic hyperglycemia. Together, these data indicate that Glo1 activity regulates the sensitivity of the kidney to hyperglycemic-induced renal pathology and that alterations in the rate of MG detoxification are sufficient to determine the glycemic set point at which DN occurs.  相似文献   
76.
Although the local application of mitomycin C may prevent epidural adhesion after laminectomy, mitomycin C can induce neurotoxicity in optic and acoustic nerves at high concentrations. To determine the safe concentration range for mitomycin C, cotton pads soaked with mitomycin C at different concentrations(0.1, 0.3, 0.5, and 0.7 mg/mL) were immediately applied for 5 minutes to the operation area of rats that had undergone laminectomy at L1. Rat sciatic nerves, instead of dorsal nerves, were used in this study. The results showed that mitomycin C at 0.1–0.5 mg/mL did not damage the structure and function of the sciatic nerve, while at 0.7 mg/mL, mitomycin C significantly reduced the thickness of the sciatic nerve myelin sheath compared with lower concentrations, though no functional change was found. These experimental findings indicate that the local application of mitomycin C at low concentrations is safe to prevent scar adhesion following laminectomy, but that mitomycin C at high concentrations( 0.7 mg/mL) has potential safety risks to peripheral nerve structures.  相似文献   
77.
This study describes the properties of an amphotericin B-containing mucoadhesive nanostructured lipid carrier (NLC), with the intent to maximize uptake within the gastrointestinal tract. We have reported previously that lipid nanoparticles can significantly improve the oral bioavailability of amphotericin B (AmpB). On the other hand, the aggregation state of AmpB within the NLC has been ascribed to some of the side effects resulting from IV administration. In the undissolved state, AmpB (UAmpB) exhibited the safer monomeric conformation in contrast to AmpB in the dissolved state (DAmpB), which was aggregated. Chitosan-coated NLC (ChiAmpB NLC) presented a slightly slower AmpB release profile as compared to the uncoated formulation, achieving 26.1% release in 5?hours. Furthermore, the ChiAmpB NLC formulation appeared to prevent the expulsion of AmpB upon exposure to simulated gastrointestinal pH media, whereby up to 63.9% of AmpB was retained in the NLC compared to 56.1% in the uncoated formulation. The ChiAmpB NLC demonstrated mucoadhesive properties in pH 5.8 and 6.8. Thus, the ChiAmpB NLC formulation is well-primed for pharmacokinetic studies to investigate whether delayed gastrointestinal transit may be exploited to improve the systemic bioavailability of AmpB, whilst simultaneously addressing the side-effect concerns of AmpB.  相似文献   
78.
79.
Background: Treatment of uremia is now dominated by dialysis; in some cases, patients are treated with dialysis for decades, but overall outcomes are disappointing. A number of studies have confirmed the relevance of several experimental insights to the pathogenesis of uremia, but the specific biomarkers of uremia have not been fully elucidated. To date, our knowledge about the alterations in DNA 5-hydroxymethylcytosine (5-hmC) in uremia is unclear, to investigate the role of DNA 5-hmC in the onset of uremia, we performed hMeDIP-chip between the uremia patients and the normal controls from the experiment to identify differentially expressed 5-hmC in uremia-associated samples. Methods: Extract genomic DNA, using hMeDIP-chip technology of Active Motif companies for the analysis of genome-wide DNA 5-hmC, and quantitative real-time PCR confirmation to identify differentially expressed 5-hmC level in uremia-associated samples. Results: There were 1875 genes in gene Promoter, which displayed significant 5-hmC differences in uremia patients compared with normal controls. Among these genes, 960 genes displayed increased 5-hmC and 915 genes decreased 5-hmC. 4063 genes in CpG Islands displayed significant 5-hmC differences in uremia patients compared with normal controls. Among these genes, 1780 genes displayed increased 5-hmC and 2283 genes decreased 5-hmC. Three positive genes, HMGCR, THBD, and STAT3 were confirmed by quantitative real-time PCR. Conclusion: Our studies indicate the significant alterations of 5-hmC. There is a correlation of gene modification 5-hmC in uremia patients. Such novel findings show the significance of 5-hmC as a potential biomarker or promising target for epigenetic-based uremia therapies.  相似文献   
80.

Objectives

The purpose of the study was to investigate the correlation between fit accuracy and fracture resistance of zirconia abutments, as well as its feasibility for clinical applications.

Methods

Twenty self-made zirconia abutments were tested with 30 Osstem GSII implants. First, 10 Osstem GSII implants were cut into two parts along the long axis and assembled with the zirconia abutments. The microgaps between the implants and the zirconia abutments were measured under a scanning electron microscope. Second, the zirconia abutments were assembled with 20 un-cut implants and photographed before and after being fixed with a central screw of 30-N cm torque. The dental films were measured by Digora for Windows 2.6 software. Then the fracture resistance of zirconia abutments was measured using the universal testing machine at 90°. All results were analyzed using SPSS13.0 software.

Results

The average internal-hexagon microgaps between the implants and zirconia abutments were 19.38 ± 1.34 μm. The average Morse taper microgap in the implant–abutment interface was 17.55 ± 1.68 μm. The dental film showed that the Morse taper gap in the implant–abutment interface disappeared after being fixed with a central screw of 30-N cm torque, and the average moving distance of the zirconia abutments to the implants was 0.19 ± 0.02 mm. The average fracture resistance of zirconia abutments was 282.93 ± 17.28 N. The internal-hexagon microgap between the implants and zirconia abutments was negatively related to the fracture resistance of the abutments (r1 = −0.97, p < 0.01). The Morse taper microgap in the implant–abutment interface was negatively related to the fracture resistance of the abutments (r2 = −0.84, p < 0.01).

Conclusions

The microgap between implant and abutment was negatively related to the fracture resistance of the abutment, while the internal-hexagon microgap has better correlation than the Morse taper microgap. The closure of microgap is helpful to improve the fracture resistance of zirconia abutments. The fracture resistance of zirconia abutments can satisfy the clinical application.  相似文献   
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