On the validity of Fourier's law in systems with spatially varying strain rates

Non-equilibrium molecular dynamics (NEMD) simulations are used to study the generation of heat fluxes in systems with spatially varying shear rates. We show that the kinetic temperature, when used in Fourier's law of heat conduction, does not correctly account for the heat flux, and that the normal temperature as described by Rugh (1997, Phys. Rev. Lett., 78, 772), should be used. Only in the absence of normal temperature gradients can heat fluxes due to strain rate coupling be correctly calculated.     

A New Isoflavone Glucoside from Astragalus membranaceus

TheAstragalusrootisaveryoldandwell-kn0wndrugintraditionalChinesemedicine,usedasanantiperspirant,adiureticandatonic.InourchemicalstudiesonRadixAstragali,weobtainedseveralc0mpounds.Thispaperdescribesthestructuralelucidationofanewis0flavoneglycoside,3'-meth0xy-5'-hydroxy-is0flavoneglucosideI.CompoundI,paleyellowneedle-crystals,mp232~234"C,withm0lecularf0rmulaofCzzHzz0lobased0ntheLD-MS[M K] 485.O847(Calc-485.O844),wasshownt0haveaphenolicgroupbyitsc0lor-reactionwith3?Cl3inethanolandthehyd…     

PHOTOCHEMICAL REACTIONS IN RIGID MEDIA-I. THE EFFECT OF GELATIN ON THE AEROBIC PHOTOCHEMISTRY OF RIBOFLAVIN IN AQUEOUS SOLUTION

Abstract— The addition of potassium iodide to dilute aqueous solutions of riboflavin reduced both the rate of the aerobic photolysis and the fluorescence quantum yield of riboflavin in the same proportions. This indicated that under these conditions the photolysis proceeded from the singlet excited state. The addition of gelatin to aqueous solutions of riboflavin also reduced the rate of the aerobic photolysis but increased slightly the quantum yield of fluorescence. The rates and the fluorescence of solutions of riboflavin to which gelatin had been added were also reduced by the addition of potassium iodide but in this case the effect on the rate was proportionately greater than the effect on the fluorescence. The data suggests that in the presence of gelatin the mechanism of the reaction is changed and that the triplet state becomes more important.     

肿瘤的化学治疗——ⅩⅫ.DL-N-二氯乙酰基-7-硝基色氨酸及其有关化合物的合成

1.本文叙述以7-硝基吲哚(ⅩⅣ)为原料,合成DL-N-二氯乙酰基-7-硝基色氨酸(Ⅷ)及其乙酯(Ⅺ);从DL-色氨酸(Ⅰ_a)制备DL-N-二氯乙酰基色氨酸(Ⅶ).2.从7-硝基克胺(ⅩⅤ)合成7-硝基吲哚乙酸(Ⅹ)及其甲酯(ⅩⅢ_a)和乙酯(ⅩⅢ_b).3.化合物Ⅷ和Ⅺ对HeLa细胞有明显的抑制作用.     

A Green Approach to Producing Polymer Microparticles for Local Sustained Release of Flavopiridol

Poly(lactic-co-glycolic acid)(PLGA) microparticles represent an important class of materials used for drug delivery. Current synthesis frequently uses conventional emulsion, where dichloromethane(DCM) is used as the organic phase solvent. Due to the health and environmental toxicity of DCM and its slow degradation, this work replaces DCM with a greener solvent, dimethyl carbonate(DMC). To attain narrow distribution of PLGA particle size, microfluidic flow focusing was chosen over conventional emulsion. This new approach successfully produced PLGA microparticles encapsulated with flavopiridol, a kinase inhibitor. These particles exhibit sustained release profile more desirable than the conventional counterparts. The cytotoxicity and activity tests have demonstrated high biocompatibility and efficacy of these PLGA particles. The high sustainability is also evaluated using simple E-Factor(sEF) and complete E-Factor(cEF). The lower health and environmental toxicities of DMC than DCM are evidenced by approximately one order of magnitude higher in lethal dose, i. e., 50%(LD₅₀) values in rat, 5-fold faster degradation rate, and 30% higher GlaxoSmithKline(GSK) combined greenness value. The approach reported in this work shall provide a new and green means for drug delivery in general. The products enable local sustained delivery of flavopiridol for prevention of post-traumatic osteoarthritis, and anti-cancer therapy.