Retinoic acid conjugates as potential antitumor agents: synthesis and biological activity of conjugates with Ara-A, Ara-C, 3(2H)-furanone, and aniline mustard moieties

In a dual targeting approach, to explore the ability of tretinoin (all-trans-retinoic acid) to behave as a covalent carrier for cytotoxic entities, conjugates of retinoic acid with a few representative molecules, being important examples of antitumor pharmacophores (i.e., nucleoside analogues and alkylating agents), have been synthesized and tested for their cytostatic and differentiating activity. All compounds were stable to in vitro hydrolysis in human plasma and more lipophilic than the parent compounds, thus consenting enhanced uptake into the cells. Among the nucleoside analogues the Ara-C derivatives 3 and 6 and the Ara-A derivative 7 proved the most cytostatic (IC50 < 0.32 microgram/mL) resulting from 25- to > 144-fold more active (Ara-A derivatives) or at least as equally active (Ara-C derivatives) as compared to the parent nucleosides. Compound 3, endowed with a highly lipophilic silyl moiety at the 3' and 5' positions, showed the highest differentiating activity (54% and 44% differentiated HL-60 cells at 0.2 and 0.05 microgram/mL respectively). With regard to the retinoic acid conjugates of alkylating agents, compound 10 was the most cytostatic agent (IC50 < 0.32 microgram/mL) and the most potent differentiating agent (33-34% at 0.32 and 0.08 microgram/mL). These structures may also be regarded as analogs of either retinoic acid or the cytotoxic compound.     

Primary lymphoma of the breast. Three cases of non-Hodgkin lymphoma

Primary and sole breast lymphoma is a very rare disease. With the review of our series of 616 cases operated on for breast cancer, only 3 cases (0.48%) of primary breast non-Hodgkin lymphoma (LNH) have been observed. The authors outline the problems concerning diagnosis and therapy of this rare disease: pathological and immunohistochemical aspects are discussed. They stress the importance of staging in order to plan a correct multidisciplinary approach.     

Thermoplastic elastomeric composition based on maleic anhydride–grafted ground rubber tire

Ground rubber tire (GRT) powder was maleated in an internal mixer using maleic anhydride and dicumyl peroxide at 160°C. Maleated GRT was characterized by using X‐ray photoelectron spectroscopy, Fourier transform infrared spectroscopy, wettability, and differential scanning calorimetry. The physical properties of the dynamically vulcanized 60 : 40, rubber : plastic composition based on acrylated high‐density polyethylene as the plastic phase and ethylene propylene diene rubber containing maleated GRT as the rubber phase were found to be greater than the corresponding composition containing nonmaleated GRT. The blend was found to be reprocessable, like themoplastic elastomers. © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 370–378, 2002; DOI 10.1002/app.10348     

Effect of nickel content on the formation and properties of amorphous Al100-xRE5Nix alloys

The thermal stability and formation range of amorphous Al100-xLn5Nix (x = 3, 5, 9, 13, 17, 21, 23) alloys were studied by differential scanning calorimetry and X-ray diffraction techniques. The microhardness, Hv, of these Al–RE–Ni alloys was measured. The experimental results show that toughness was adversely affected by increase in the nickel content. The atomic size factor was applied to explain the formation mechanism of aluminium-based amorphous alloys by the atomic clusters model. The minimum concentration of nickel in Al–RE–Ni alloys results from the effective atomic volume difference of the nickel and aluminium atoms. This revised version was published online in November 2006 with corrections to the Cover Date.     

高含硫钻井液缓蚀剂的合成及性能研究

本文合成了抑制H₂S腐蚀的咪唑啉类缓蚀剂,并研究了它们的性能。正交试验表明,最佳合成条件是:反应温度:190～200℃;酸:胺(mol比)=1:1.05;反应时间以3～5小时为宜。根据以上条件合成的缓蚀剂,在含有3200mg/lH₂S的泥浆中,用量为0.2%时,抑制效果能达到80～90%,与碱式碳酸锌复配使用时,能提高缓蚀效率和降低碱式碳酸锌的用量,并发现缓蚀剂与CaO之间具有明显的协同效应。泥浆流变性能试验表明,缓蚀剂能提高泥浆的动切力和动塑比,对失水量影响不大。此外,利用X-射线衍射试验证明:(1)低碳钢在含H₂S的泥浆中,腐蚀产物的主要组成为Fe₉S₆;(2)H₂S会破坏FCLS的稳定性,分解出Fe²⁺,与H₂S反应生成面心立方的Fe₂S₄。     

Influence of heat transfer on anodic oxidation of aluminium

The influence of convective heat transfer on constant current density anodizing of aluminium in sulfuric acid has been examined in a wall-jet electrode reactor. The uniformity of the anodic film thickness is related to the local electrode temperature distribution, which is dependent on the convection. The higher the local temperature, the greater the local oxide thickness. An increased local temperature enhances local field assisted oxide dissolution at the pore bases, and consequently acts to increase the local current density. At relatively high current densities, local features develop on the electrode surface, accompanied by high initial, local temperature rises. The relevance of such local features, limiting useful oxide growth, is considered further.     

SCRATCH RESISTANT POLYIMIDE COATINGS FOR ALUMINOSILICATE GLASS SURFACES

Several polyimide resins were tested as possible scratch resistant coatings for aluminosilicate glass centrifuge tubes. Tubes with siloxane pretreatments provided the best adhesion between the polyimide and glass surface. Resins synthesized with an alkoxysilane group incorporated into the polyimide chain also showed improved adhesion, but the results were not as significant as when the pretreatment was used. Elastic recovery and effective Young's modulus of the polyimide coatings were calculated from nano-scratching. The results indicate that polyimides with a lower modulus, and higher elastic recovery, protected the glass surface best, exhibiting compression of the coating layer. An example was poly-4-4'-oxydiphenylene pyromellitimide (PMDA-ODA), whereas the coatings with a high effective Young's modulus and low elastic recovery ruptured. An example of a failed coating was poly-4,4'-carbonyldiphenylene 3,3',4,4'-biphenylenetetracarboximide (BPDA-DABP) which had low amount of elastic recovery, high effective Young's modulus and a large amount of flaking during macroscratch testing.     

A comparison of procedures for estimating the impact of nondensable gases on steam condensation taking into account the interaction of power engineering processes in the primary circuit of a nuclear power installation

We consider two procedures for evaluating the influence of nondensables on steam condensation taking into account the integral effect from interaction between the water-chemistry and thermal-hydrodynamic processes occurring in the primary coolant circuit of a nuclear power installation (NPI). Results from calculations of the passive safety system of an NPI are given.     

Effects of e-enforcement in the Netherlands

E-enforcement, or electronic enforcement, is the use of electronic tools in law enforcement. We shall distinguish between the first and second generations of e-enforcement. The first generation of e-enforcement tools provided means of "automated enforcement". This article is based on our research into the effects of two forms of second generation e-enforcement: the digital tachograph and 'Weigh in Motion' (WIM). The digital tachograph replaces the analog tachograph in all heavy goods vehicles within the European Union. The equipment registers drivers' driving and rest times. Weigh in Motion with Video (WIM-Vid) is a system involving sensors in the road and cameras, which detect and register overloading of heavy goods vehicles. The WIM-Vid system was developed and implemented in the Netherlands and is currently attracting international attention. We compare the situation prior to the introduction of these e-enforcement measures to the situation after the introduction of e-enforcement.