耐硫催化剂上合成混合醇的研究

通过改进制备方法和添加助剂，用浸渍－热分解法制得了具有高活性和高选择性的MoS2-K-C型耐硫低碳混合醇催化剂。在8.0-11.0MPa,290-340℃，6000-12000h^-1,H2 S 浓度为100ppm 左右的条件下，在直流反应器中对催化剂进行了性能测试，结果表明，醇得率为0.14-0.47gROH(gcat·h)^-1，选择性为89-98%。同时，考察了操作条件对催化剂性能的影响。1042h的试验，证明催化剂具有很好的稳定性。     

Effect of a radial temperature gradient on the stability of the flow of a second-order fluid between two co-axial cylinders

Summary It has been found that the effect of a radial temperature gradient on the Taylor stability problem for a viscoelastic fluid and for a Newtonian fluid is the same.

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Résumé On montre que l'effet d'un gradient de la température radial sur le problème de stabilité de Taylor pour un fluide viscoélastique est semblable à celui d'un fluide Newtonien.

     

Carbon nanotube-enhanced separation of DNA fragments by a portable capillary electrophoresis system with contactless conductivity detection

It was demonstrated that separation of DNA fragments by a CE-contactless conductivity detection system (CE-CCD) could be enhanced with multiple-wall carbon nanotubes (MWCNs) as buffer additive. For HaeIII digest of PhiX174 DNA, optimized MWCN concentration was obtained when the MWCN was above its threshold concentration, at which MWCN could form a network in the buffer as pseudostationary phase to provide additional interaction sites. In the case of larger DNA, MWCN near or below its threshold concentration was enough to provide great improvement of the resolution, which was shown by the separation of the 2-Log DNA ladder. Furthermore, the buffer containing MWCN could provide a more stable baseline in the CE-CCD system, owing to less fluctuation of its conductivity. Compared with CE-UV, CE-CCD with MWCN could provide lower LODs as well as better resolution.     

Cyclometalated Palladium(II) N‐Heterocyclic Carbene Complexes: Anticancer Agents for Potent In Vitro Cytotoxicity and In Vivo Tumor Growth Suppression

Palladium(II) complexes are generally reactive toward substitution/reduction, and their biological applications are seldom explored. A new series of palladium(II) N‐heterocyclic carbene (NHC) complexes that are stable in the presence of biological thiols are reported. A representative complex, [Pd(C^N^N)(N,N′‐nBu₂NHC)](CF₃SO₃) ( Pd1 d , HC^N^N=6‐phenyl‐2,2′‐bipyridine, N,N′‐nBu₂NHC=N,N′‐di‐n‐butylimidazolylidene), displays potent killing activity toward cancer cell lines (IC₅₀=0.09–0.5 μm ) but is less cytotoxic toward a normal human fibroblast cell line (CCD‐19Lu, IC₅₀=11.8 μm ). In vivo anticancer studies revealed that Pd1 d significantly inhibited tumor growth in a nude mice model. Proteomics data and in vitro biochemical assays reveal that Pd1 d exerts anticancer effects, including inhibition of an epidermal growth factor receptor pathway, induction of mitochondrial dysfunction, and antiangiogenic activity to endothelial cells.     

On Frobenius algebras and the quantum Yang-Baxter equation

It is shown that every Frobenius algebra over a commutative ring determines a class of solutions of the quantum Yang-Baxter equation, which forms a subbimodule of its tensor square. Moreover, this subbimodule is free of rank one as a left (right) submodule. An explicit form of a generator is given in terms of the Frobenius homomorphism. It turns out that the generator is invertible in the tensor square if and only if the algebra is Azumaya.

     

Cisplatin cyclodextrin complexes as potential free radical chemoradiosensitizers for enhanced cisplatin treatment of cancers: a quantum mechanical study

It has been shown in this study that {CisPt@[n]CD} complexes formed from the anti-cancer drug cisplatin (CisPt) and cyclodextrins ([n]CD) can be a source of Pt based free radicals such as (H₃N)₂PtCl· and (H₃N)₂Pt·· species in water within a radiation environment which can produce hydrated electrons. Encapsulating CisPt within the [n]CD host takes advantage of the previously described drug delivery and reduced side effect advantages of CDs. Based on quantum mechanical modelling and literature results from other studies, it is predicted that {CisPt@[γ]CD} and the analogous 2-hydroxypropyl[β]cyclodextrin (HPBCD) complex {CisPt@HPBCD} may interact with serum albumin and engage in an enhanced permeation and retention mechanism in solid tumours, offering further synergistic advantages for radiation-{CisPt@[γ]CD} or -{CisPt@HPBCD} regimens over that of the conventional radiation-CisPt regimens in current use in anti-cancer chemoradiotherapies. Comparisons and possible advantages are made with the previously documented chemoradiosensitizing properties of the analogous cucurbit[7]uril based{CisPt@[7]CB} complex with the {CisPt@[γ]CD} and {CisPt@HPBCD} complexes suggest that all three complexes may have different and tailorable anti-tumour uses for a range of different chemotherapeutic environments or protocols.     

Solvent Effects on Aza‐anionic Cycloaromatization of 2‐(2‐Substituted‐ethynyl)benzonitriles

The methanolysis of 2‐(2‐aryl ethynyl)benzonitriles is accelerated when the polar aprotic solvents are added, which could enhance the 6‐endo pathway and give isoquinolones, though the 5‐exo pathway is occupied mostly. The yields of products would also be in creased.     

Thermal degradation kinetics of biodegradable poly(3‐hydroxybutyrate)/layered double hydroxide nanocomposites

The thermal degradation behaviors of biodegradable poly(3‐hydroxybutyrate) (PHB) and PHB/poly(ethylene glycol) phosphonates (PEOPAs)‐modified layered double hydroxide (PMLDH) nanocomposites have been investigated using thermogravimetric analysis. Effects of PMLDH contents on the isothermal degradation kinetics of PHB were explored. These experimental results show that the degradation kinetics of PHB/PMLDH nanocomposites is the chain‐scission process of cyclic β‐elimination reaction with the following autocatalytic reactions, which is very similar to that of pure PHB matrix. Further calculated data based on the autocatalytic model can fit very well with the experimental data. The E_a value of PHB/PMLDH nanocomposites is increased as the content of PMLDH increases. This can be attributed to the incorporation of more PMLDH loading to PHB induced a decrease in the degradation rate and an increase in the residual weight for PHB/PMLDH nanocomposites. © 2008 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 46: 1207–1213, 2008