Differential scanning calorimetry with curve-fitting program used to quantitatively analyze the polymorphic transformation of famotidine in the compressed compact

Differential scanning calorimetry (DSC) combined with a curve-fitting program was utilized to quantitatively determine the polymorphic composition of famotidine in the compacts prepared by different compression treatments. Two types of famotidine compacts (compact I or II) were prepared by compressing a conical shape or a flattened shape of powder bed of famotidine form B. The compact I was constructed by a transparent region in the center with an opaque region surrounded outside, but the compact II was formed by a whole opaque region only. A drilled disc sample was prepared and then directly determined by DSC analysis. The Raman spectral results clearly indicate that all the compacts whether in any region before DSC determination were only of famotidine form B and independent of compression pressure applied. Under DSC determination, however, the curve-fitted relative compositions of form B in the drilled disc I sample were gradually reduced to 23-24% with the increase of compression pressure, whereas the curve-fitted relative composition of form A was slowly increased up to 76-77%. A transitional phase of famotidine form B (form B*) in the transparent region of the compact I after applying >150 kg/cm(2) of compression pressure was easily detected, and then transformed to famotidine form A under DSC heating process. But this transitional phase and polymorphic transformation of famotidine could not be detected by other spectroscopic methods. This suggests that the DSC heating system was a preferred method not only to quantitatively analyze the polymorphic transformation of famotidine but also to find a newly transitional phase of famotidine in the compressed compact.     

岩盐型 LiTiO2的合成和表征

在常压、110℃用浓LiOH水溶液和粉末TiO2（锐钛矿）反应的方法，合成了岩盐型LiTiO2，并采用TEM、XRD、XPS、TG／DTG等手段对岩盐型LiTiO2进行了表征．结果表明，采用该方法制得的岩盐型LiTiO2为纳米颗粒状的非化学计量物质，在≤500℃其晶型是稳定的，在室温下它有较强的吸水性．     

Elastic properties of cubic, tetragonal and monoclinic ZrO2 from first-principles calculations

In terms of first-principles calculations, elastic stiffness constants C_ij’s as well as the polycrystalline aggregates including the bulk, shear, Young’s moduli, Possion’s ratio, and anisotropy factors have been predicted for three technologically important polymorphs of ZrO₂, i.e., monoclinic m-ZrO₂, tetragonal t-ZrO₂, and cubic c-ZrO₂. Here, both the strain vs. stress (S-S) and the strain vs. strain energy (S-E) methods are adopted. In the first-principles calculations, both the local density approximation (LDA) and the generalized gradient approximation (GGA) are utilized. It is found that the more accurate structural and elastic properties are determined by LDA in comparison with experimental results and the S-S method is more effective than the S-E method although the two methods predict the similar results. The predicted negative values for C₁₆, C₃₆, and C₄₅ of m-ZrO₂ suggest that the certain normal or shear stress corresponds to an opposite shear strain for reducing the total energy. Small differences of shear and Young’s modulus between m-ZrO₂ and t-ZrO₂ suggest that their mechanical properties are comparable.     

占压下埋地聚乙烯管力学响应的数值模拟

率下聚乙烯（PE）管的单轴拉伸试验,拟合得到PE本构模型的参数,确定了其屈服应力,建立了关于管道横截面对称的长方形管土模型,研究了埋地PE管在静载正压占压载荷作用下的力学响应,分析了占压参数（占压区长、占压区宽）的影响。结果表明,占压下埋地聚乙烯管竖直方向最大偏移发生在轴向横截对称面上;管内最大Mises应力随占压载荷的增大而增大,但其位置从管顶（底）转移至起拱线上;管道屈服时,占压载荷随着占压参数的增大,呈指数下降趋势。     

Performance evaluation of coherence-based adaptive imaging using clinical breast data

Sound-velocity inhomogeneities degrade both the spatial resolution and the contrast in diagnostic ultrasound. We previously proposed an adaptive imaging approach based on the coherence of the data received in the channels of a transducer array, and we tested it on phantom data. In this study, the approach was tested on clinical breast data and compared with a correlation-based method that has been widely reported in the literature. The main limitations of the correlation-based method in ultrasonic breast imaging are the use of a near-field, phase-screen model and the integration errors due to the lack of a two-dimensional (2-D) array. In contrast, the proposed coherence-based method adaptively weights each image pixel based on the coherence of the receive-channel data. It does not make any assumption about the source of the focusing errors and has been shown to be effective using 1-D arrays. This study tested its in vivo performance using clinical breast data acquired by a programmable system with a 5 MHz, 128-channel linear array. Twenty-five cases (6 fibroadenomas, 10 carcinomas, 6 cysts, and 3 abscesses) were investigated. Relative to nonweighted imaging, the average improvements in the contrast ratio and contrast-to-noise ratio for the coherence-based method were 8.57 dB and 23.2%, respectively. The corresponding improvements when using the correlation-based method were only 0.42 dB and 3.35%. In an investigated milk-of-calcium case, the improvement in the contrast was 4.47 dB and the axial and lateral dimensions of the object were reduced from 0.39 to 0.32 mm and from 0.51 to 0.43 mm, respectively. These results demonstrate the efficacy of the coherence-based method for clinical ultrasonic breast imaging using 1-D arrays.     

Bed type and flow mechanism of deep water sub-lacustrine fan fringe facies:an example from the Middle Permian Lucaogou Formation in Southern Junggar Basin of NW China

Submarine or sub-lacustrine lobe deposits are important reservoirs,but the fan fringe deposits form heterogeneities within deep water fan deposits.Fan fringe fa...     

Alpha-Lipoic Acid Inhibits Spontaneous Diabetes and Autoimmune Recurrence in Non-Obese Diabetic Mice by Enhancing Differentiation of Regulatory T Cells and Showed Potential for Use in Cell Therapies for the Treatment of Type 1 Diabetes

Type 1 diabetes (T1D) is caused by the destruction of β cells in pancreatic islets by autoimmune T cells. Islet transplantation has been established as an effective treatment for T1D. However, the survival of islet grafts is often disrupted by recurrent autoimmunity. Alpha-lipoic acid (ALA) has been reported to have immunomodulatory effects and, therefore, may have therapeutic potential in the treatment of T1D. In this study, we investigated the therapeutic potential of ALA in autoimmunity inhibition. We treated non-obese diabetic (NOD) mice with spontaneous diabetes and islet-transplantation mice with ALA. The onset of diabetes was decreased and survival of the islet grafts was extended. The populations of Th1 cells decreased, and regulatory T cells (Tregs) increased in ALA-treated mice. The in vitro Treg differentiation was significantly increased by treatment with ALA. The adoptive transfer of ALA-differentiated Tregs into NOD recipients improved the outcome of the islet grafts. Our results showed that in vivo ALA treatment suppressed spontaneous diabetes and autoimmune recurrence in NOD mice by inhibiting the Th1 immune response and inducing the differentiation of Tregs. Our study also demonstrated the therapeutic potential of ALA in Treg-based cell therapies and islet transplantation used in the treatment of T1D.     

Differential Scanning Calorimetry with Curve-Fitting Program Used to Quantitatively Analyze the Polymorphic Transformation of Famotidine in the Compressed Compact

Differential scanning calorimetry (DSC) combined with a curve-fitting program was utilized to quantitatively determine the polymorphic composition of famotidine in the compacts prepared by different compression treatments. Two types of famotidine compacts (compact I or II) were prepared by compressing a conical shape or a flattened shape of powder bed of famotidine form B. The compact I was constructed by a transparent region in the center with an opaque region surrounded outside, but the compact II was formed by a whole opaque region only. A drilled disc sample was prepared and then directly determined by DSC analysis. The Raman spectral results clearly indicate that all the compacts whether in any region before DSC determination were only of famotidine form B and independent of compression pressure applied. Under DSC determination, however, the curve-fitted relative compositions of form B in the drilled disc I sample were gradually reduced to 23–24% with the increase of compression pressure, whereas the curve-fitted relative composition of form A was slowly increased up to 76–77%. A transitional phase of famotidine form B (form B*) in the transparent region of the compact I after applying >150 kg/cm² of compression pressure was easily detected, and then transformed to famotidine form A under DSC heating process. But this transitional phase and polymorphic transformation of famotidine could not be detected by other spectroscopic methods. This suggests that the DSC heating system was a preferred method not only to quantitatively analyze the polymorphic transformation of famotidine but also to find a newly transitional phase of famotidine in the compressed compact.     

Power substation magnetic field measurement using digital signalprocessing techniques

In this paper, a method is presented for measurement of power frequency magnetic fields due to distorted sinusoidal currents in power systems. The proposed method is an integral approach and consists of a multi-rate digital signal processor, an adaptive filter and an overlap processor. In field test, actual test results are accomplished by a standard area-type measurement setup to identify and characterize magnetic fields distribution of a 69 kV SF₆-gas insulated substation (GIS) using the proposed method