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排序方式: 共有137条查询结果,搜索用时 46 毫秒
31.
The multicomponent T2 relaxation in bovine nasal cartilage (BNC) was investigated by nuclear magnetic resonance spectroscopy using the Carr-Purcell-Meiboom-Gill (CPMG) sequence and microscopic magnetic resonance imaging (μMRI) method using a CPMG-SE imaging sequence. All experimental data were analyzed by the non-negative least square (NNLS) procedure. Only one T2 component was found in BNC by both experimental methods (about 113 and 170 ms before and after being enzymatically digested by trypsin). Several experimental and specimen-related factors were investigated in this study, and it was found that some of them could produce artificial multi-component T2, including the use of the standard MSME imaging sequence at certain imaging gradients. 相似文献
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In vivo triple quantum filtered twisted projection sodium MRI of human articular cartilage 总被引:2,自引:0,他引:2
Borthakur A Hancu I Boada FE Shen GX Shapiro EM Reddy R 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1999,141(2):286-290
In this work, we present the first triple quantum filtered (TQF) sodium MR images of the human knee joint in vivo. A 3D TQF data set of 16 slices was obtained in 20 min using a TQF pulse sequence preencoded to a twisted projection imaging readout. Images clearly demarcate patellar cartilage and also demonstrate fluid signal suppressed by the triple quantum filter. Biexponential transverse relaxation times were calculated by fitting the TQF free induction decay to a theoretical signal expression. The average values from three healthy volunteers were T(2fall)(*) = 9.59 +/- 0.35 ms and T(2rise)(*) = 0.84 +/- 0.06 ms. Application of TQF imaging in biological tissues is discussed. 相似文献
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Eliav U Keinan-Adamsky K Navon G 《Journal of magnetic resonance (San Diego, Calif. : 1997)》2003,165(2):276-281
The splitting and the lineshape of the satellite transitions of 23Na are measures of the residual quadrupolar interaction and its distribution, which are related to the degrees of order and binding of sodium in biological tissues. However, these transitions are often masked by the stronger signals of the central transition and the isotropic sodium ions. A way to suppress the central signals, while preserving the lineshape and the intensity of the satellites, is suggested and tested on a liquid crystal and on bovine articular cartilage. 相似文献
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17400鲨鱼软骨血管生成抑制因子的纯化及生物学活性研究 总被引:4,自引:0,他引:4
采用盐酸胍抽提、膜超滤、丙酮分级沉淀、Sephadex-75柱层析和C4反相高效液相色谱等分离步骤,从广东阳江鲨鱼软骨中纯化获得新的鲨鱼软骨血管生成抑制因子SCAI-c(SharkCartilageAngiogenesis In-hibitor-c,SCAI-c);SDS-PAGE电泳银染显示为一条带,根据蛋白质的相对迁移率计算,分子量为17400;它对鸡胚绒毛尿囊膜血管的形成具有显著抑制效应,并有明显的浓度依赖关系.SCAI-c与SCAI-a具有类似的生物学特征. 相似文献
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Hae Lim Kim Hae Jin Lee Dong-Ryung Lee Bong-Keun Choi Seung Hwan Yang 《Molecules (Basel, Switzerland)》2020,25(22)
The aim of this study was to determine the anti-osteoarthritic effects of LI73014F2, which consists of Terminalia chebula fruit, Curcuma longa rhizome, and Boswellia serrata gum resin in a 2:1:2 ratio, in the monosodium iodoacetate (MIA)-induced osteoarthritis (OA) rat model. LI73014F2 was orally administered once per day for three weeks. Weight-bearing distribution and arthritis index (AI) were measured once per week to confirm the OA symptoms. Synovial membrane, proteoglycan layer, and cartilage damage were investigated by histological examination, while synovial fluid interleukin-1β level was analyzed using a commercial kit. Levels of pro-inflammatory mediators/cytokines and matrix metalloproteinases (MMPs) in the cartilage tissues were investigated to confirm the anti-osteoarthritic effects of LI73014F2. LI73014F2 significantly inhibited the MIA-induced increase in OA symptoms, synovial fluid cytokine, cartilage damage, and expression levels of pro-inflammatory mediators/cytokines and MMPs in the articular cartilage. These results suggest that LI73014F2 exerts anti-osteoarthritic effects by regulating inflammatory cytokines and MMPs in MIA-induced OA rats. 相似文献
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The steady-state composition of articular cartilage has previously been described as a balance between the metabolism of matrix molecules and the loss of these components from the tissue. Single compartment kinetic models have previously been developed to describe the relationship between these processes and overall (spatially-averaged) concentration of matrix molecules. Here, we develop a continuum model to describe the relationship between spatially-varying matrix concentrations and the processes of matrix formation, binding, degradation, and molecular transport within and from the cartilage tissue. At steady-state, the resultant concentration profile, and also spatially-averaged concentration, are predicted to depend on the balance between diffusivity and binding rate, diffusivity and formation rate, and various rate processes, some of which depend on tissue thickness. The predicted concentration profile, for certain parameter values, exhibits similarities to that known to exist for the proteoglycan matrix component, suggesting that transport factors may play an important role in causing the spatial variation in this component. Under other conditions, the predicted concentration profile may have a large portion of bound components and be relatively constant, consistent with the known distribution of collagen in cartilage. Thus, the continuum model may provide insight into the biophysical mechanism underlying matrix distribution within different regions of articular cartilage. 相似文献
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