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731.
Jung da Y Kim EY Joo SY Park JB Moon C Kim SH Sim EY Joh JW Kwon CH Kwon GY Kim SJ 《Experimental & molecular medicine》2008,40(1):1-10
Pancreatic islet transplantation can correct the abnormal glucose metabolism of Type 1 diabetes. Although immunosuppressants greatly reduce the acute rejection rate in transplant patients, the long-term side effects can be debilitating. Therefore, researchers are seeking to develop new immunosuppressive regimens that induce maximal levels of immunosuppression with minor side effects. Rosmarinic acid (Ros A) is a secondary metabolite of certain herbs and has multiple biological activities, including anti-inflammatory effects. Here, we have investigated whether treatment of mice with a combination of Ros A and anti-CD154 monoclonal antibody (MR1) improves islet allograft survival in a murine model. After transplantation, the mice were treated with either Ros A, MR1, or both (the "double" treatment). Allograft survival was prolonged in the double-treated animals compared to animals that received only Ros A or MR1. As is the case with the single-treated animals at 15 days after transplantation, the double-treated recipients did not display a significant decrease in the expression of cytokines or the population of activated T cells. Infiltrating CD3(+) T cells were reduced in the MR1- or double therapy relative to control or RosA group. However, at the same time point, double-treated graft showed fewer apoptotic cells and increased expression of insulin and glucagons, compared to the single-treatment groups. Furthermore, long-term (>150 days) allografts that were received with double therapy exhibited larger islet clusters and contained more insulin- and glucagon-positive cells, relative to the MR1-treated grafts. In conclusion, treatment with both Ros A and MR1 has a synergistic effect in murine islet allotransplantation. 相似文献
732.
Ucun F Güçlü V Sağlam A 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2008,70(3):524-531
The optimized molecular structures, vibrational frequencies and corresponding vibrational assignments of conformations of 2-hydroxy-3-nitropyridine and 3-hydroxy-2-nitropyridine molecules have been investigated using ab initio Hartree-Fock (HF) and density functional theory (B3LYP) methods with 6-311++G(d,p) basis set. The comparison of the experimental and calculated spectra of the molecules have shown that they exist in two conformations with the two OH bond angles (110 degrees and 250 degrees ) respective to the CO bond in the ground state and their energy curves having two minimums have been drawn. 相似文献
733.
734.
Radovan Bast Dr. Andreas Heßelmann Dr. Paweł Sałek Dr. Trygve Helgaker Prof. Dr. Trond Saue Dr. 《Chemphyschem》2008,9(3):445-453
We test the performance of four‐component relativistic density functional theory by calculating the static and frequency‐dependent electric dipole–dipole polarizabilities of all (ground‐state) closed‐shell atoms up to Ra. We consider 12 nonrelativistic functionals, including three asymptotically shape‐corrected functionals, by using two smooth interpolation schemes introduced by the Baerends group: the gradient‐regulated asymptotic connection (GRAC) procedure and the statistical averaging of (model) orbital potentials (SAOP). Basis sets of doubly augmented triple‐zeta quality are used. The results are compared to experimental data or to accurate ab initio results. The reference static electric dipole polarizability of palladium has been obtained by finite‐field calculations using the coupled‐cluster singles, doubles, and perturbative triples method within this work. The best overall performance is obtained using hybrid functionals and their GRAC shape‐corrected versions. The performance of SAOP is among the best for nonhybrid functionals for Group 18 atoms but its precision degrades when considering the full set of atoms. In general, we find that conclusions based on results obtained for the rare‐gas atoms are not necessarily representative of the complete set of atoms. GRAC cannot be used with effective core potentials since the asymptotic correction is switched on in the core region. 相似文献
735.
Xie Jintao Wang Jian Lyu Yiming Wang Dingbiao Peng Xu Liu Huadong Xiang Sa 《Journal of Thermal Analysis and Calorimetry》2022,147(12):6883-6892
Journal of Thermal Analysis and Calorimetry - The CO2-based mixed refrigerants R744/R152a and R744/R161 are proposed to enhance the thermodynamic performance of pure CO2 refrigerant. The basic... 相似文献
736.
A major unresolved problem of density functional theory is the yet unknown exchange-correlation functional, which leads to a proliferation of its less or more successful approximations. A practical implementation of these numerous functionals can present a substantial challenge particularly if the higher order functional derivatives are required. We present a systematic method of functional implementation. The method allows a clean handling of a large number of functionals in a mutually independent way. We developed an extensive set of automatic test routines to facilitate functional and derivative testing with respect to the implementation correctness and numerical stability. An integral part of the presented solution is a program for automatic code generation from analytical formulas that uses only freely available tools. Code for evaluation of functionals and their first, second, third, and fourth derivatives can be generated, which accelerates the development, implementation, and testing of new functionals. 相似文献
737.
Liquid crystalline dendrimers 总被引:1,自引:0,他引:1
738.
A stereospecific synthesis of 11-cis-retinoids has as its key step the hitherto unexplored palladium-catalyzed cross-coupling of trans-trienyl electrophiles and (1Z,3E)-penta-1,3-dienyl boronates (a Suzuki-Miyaura reaction) or stannanes (a Stille reaction). This highly convergent approach constitutes the first application of cis-organometallic moieties to the synthesis of 11-cis-retinoids and represents a general, straightforward route to the visual chromophore. 相似文献
739.
Buchmüller W Hamaguchi K Lebedev O Ramos-Sánchez S Ratz M 《Physical review letters》2007,99(2):021601
We study the possibility of realizing the neutrino seesaw mechanism in the E(8) x E(8) heterotic string. In particular, we consider its Z6 orbifold compactifications leading to the supersymmetric standard model gauge group and matter content. We find that these models possess all the necessary ingredients for the seesaw mechanism, including the required Dirac Yukawa couplings and large Majorana mass terms. We argue that this situation is quite common in heterotic orbifolds. In contrast with the conventional seesaw of grand unified theories (GUTs), no large GUT representations are needed to generate the Majorana mass terms. The total number of right-handed neutrinos can be very large, up to O(100). 相似文献
740.