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61.
In this paper, the “FLIC” difference method with triangular mesh is adopted to numerically simulate the regular and Mach reflections
that occur when a shock wave pass around a wedge. The compuational result is compared with the shock tube experimental results
of G. Ben-Dor and I. I. Glass. The comparison shows that the position, shape of shock wave and height of Mach stem all show
a good agreement. Consequently, the “FLIC” difference method with triangular mesh is quite satisfactory in numerical simulation
of the regular and Mach reflections. 相似文献
62.
焦一鸣 《核聚变与等离子体物理》1994,14(4):9-17
本文利用环形系统的Grad-Shafranov方程得到了D形截面的托卡马克磁面位形,并利用射线追踪技术研究了D形磁面位形下低杂波的运动形态。定性地研究了D形磁面位形下利用低杂波驱动电流的可行性,优化地给出了驱动电流的最佳方式。 相似文献
63.
64.
65.
Veronika Kozlovskaya Yiming Yang Fei Liu Kevin Ingle Aftab Ahmad Ganesh V. Halade Eugenia Kharlampieva 《Molecules (Basel, Switzerland)》2022,27(11)
Limited tissue selectivity and targeting of anticancer therapeutics in systemic administration can produce harmful side effects in the body. Various polymer nano-vehicles have been developed to encapsulate therapeutics and prevent premature drug release. Dually responsive polymeric vesicles (polymersomes) assembled from temperature-/pH-sensitive block copolymers are particularly interesting for the delivery of encapsulated therapeutics to targeted tumors and inflamed tissues. We have previously demonstrated that temperature-responsive poly(N-vinylcaprolactam) (PVCL)-b-poly(dimethylsiloxane) (PDMS)-b-PVCL polymersomes exhibit high loading efficiency of anticancer therapeutics in physiological conditions. However, the in-vivo toxicity of these polymersomes as biocompatible materials has not yet been explored. Nevertheless, developing an advanced therapeutic nanocarrier must provide the knowledge of possible risks from the material’s toxicity to support its future clinical research in humans. Herein, we studied pH-induced degradation of PVCL10-b-PDMS65-b-PVCL10 vesicles in-situ and their dually (pH- and temperature-) responsive release of the anticancer drug, doxorubicin, using NMR, DLS, TEM, and absorbance spectroscopy. The toxic potential of the polymersomes was evaluated in-vivo by intravenous injection (40 mg kg−1 single dose) of PVCL10-PDMS65-PVCL10 vesicles to mice. The sub-acute toxicity study (14 days) included gravimetric, histological, and hematological analyses and provided evidence for good biocompatibility and non-toxicity of the biomaterial. These results show the potential of these vesicles to be used in clinical research. 相似文献
66.
Enhancing the thermostability of a novel beta-agarase AgaB through directed evolution 总被引:1,自引:0,他引:1
To increase the thermostability of β-agarase AgaB by directed evolution, the mutant gene libraries were generated by error-prone
polymerase chain reaction (PCR) and deoxyribonucleic acid (DNA) shuffling. Mutants with high thermostability were screened
by a simple method based on agarase-degrading agar to generate a clear zone on the agar plate. A mutant S2 was obtained through
two rounds of error-prone PCR and a single round of DNA shuffling and selection. It has higher thermostability and slightly
increased catalytic activity than wild-type AgaB. Melting temperature (T
m) of S2, as determined by circular dichroism, is 4.6 °C higher than that of wild-type AgaB, and the half-life of S2 is 350 min
at 40 °C, which is 18.4-fold longer than that of the wild-type enzyme. Saturation mutagenesis and hydrophobic cluster analysis
indicated that hydrophobic interaction might be the key factor that enhances the enzyme stability. 相似文献
67.
The authors are concerned with a class of one-dimensional stochastic Anderson models with double-parameter fractional noises, whose differential operators are fractional. A unique solution for the model in some appropriate Hilbert space is constructed. Moreover, the Lyapunov exponent of the solution is estimated, and its HSlder continuity is studied. On the other hand, the absolute continuity of the solution is also discussed. 相似文献
68.
Zero‐valent iron particles were prepared by wet reduction chemistry assisted with ultrasonic treatment. Such prepared particles have uniform size, exhibit crystalline structure and show strong paramagnetic property. Their surface modification by coating poly(N‐vinyl‐2‐pyrrolidone) (PVP) was investigated. The resulting Fe(0)‐PVP particles were monodispersed and possessed enhancing magnetization saturation. Those synthesis conditions to control the particle size and distribution were exploited. 相似文献
69.
Jiang X Cao Y Wang Y Liu L Shen F Wang R 《Journal of the American Chemical Society》2010,132(43):15328-15333
Drug-lead synthesis through rapid construction of chiral molecular complexity around the biologically relevant framework using a highly efficient strategy is a key goal of organic synthesis. Molecules bearing a spirooxindole-type framework exhibit important bioactivities. Herein, we present a highly efficient and convenient strategy that allows rapid construction of unique optically active spiro[oxazoline-3,3'-oxindole]s through the organocatalyzed asymmetric synthesis of spirocyclic thiocarbamates via an aldol reaction. Preliminary biological evaluation of several of the spirooxazolines using a model of acute neuroinflammation revealed promising antipyretic activity and provided an opportunity to discover new antipyretic agents. 相似文献
70.
以(-)-葑酮为原料经中间体葑胺合成4-葑基氨基硫脲(4), 4与醛缩合得到11个未见文献报道的葑基缩氨基硫脲(5), 5用六氰合铁(III)酸钾氧化成环得到相应的2,5-二取代-1,3,4-噻二唑类化合物(6); 产物的结构经IR, NMR和元素分析确认, 并用X射线衍射法测定化合物6d的晶体结构. 化合物6d属单斜晶系, P2(1)空间群, 晶胞参数 a=1.18719(10) nm, b=1.48814(18) nm, c=1.21629(12) nm, β=118.113(2)°, Mr=343.48, V=1.8953(3) nm3, Dc=1.204 Mg/m3, Z=4, λ=0.071073 nm, μ(Mo Kα)=0.181 mm-1, F(000)=736. 相似文献