基于超高效液相色谱的改良直接肽反应试验预测化学物皮肤致敏性

建立基于超高效液相色谱改良直接肽反应试验预测化学物致敏性并提高检测效率和通量。选择8种已知皮肤致敏性化合物与半胱氨酸多肽或赖氨酸多肽反应24 h,通过基于超高效液相色谱或高效液相色谱的检测系统计算得到多肽消耗率预测受试物皮肤致敏性。结果显示,基于超高效液相色谱的改良直接多肽反应试验能正确区分8种化学物为皮肤致敏物或非致敏物,且节省检测时间,提高检测通量,同时色谱峰分离度更高。     

Synthesis of novel oxidizable polymerization sensitizers based on the dithiinoquinoxaline skeleton

Novel dyes, based on the dithiinoquinoxaline skeleton, were synthesized and characterized using ¹H NMR spectroscopy and chemical ionization mass spectroscopy. Their spectral properties, such as absorption, emission spectra and quantum yield of fluorescence, were also measured. Electron donating properties of the title compounds were estimated on the basis of DFT calculations. The studied dyes were used as oxidizable sensitizers for 2,4,6-tris(trichloromethyl)-1,3,5-triazine (Tz). The dye/Tz photoredox pairs were found to be effective visible-wavelength initiators of free radical polymerization. The ability of these systems to act as photoinitiators strongly depended upon the free energy change of the photoinduced electron transfer from the excited dyes to Tz. It has been shown that the intermolecular electron transfer is the limiting step in the photopolymerization initiated by these studied initiator systems.     

How Far Are We from Prescribing Fasting as Anticancer Medicine?

(1) Background: the present review provides a comprehensive and up-to date overview of the potential exploitation of fasting as an anticancer strategy. The rationale for this concept is that fasting elicits a differential stress response in the setting of unfavorable conditions, empowering the survival of normal cells, while killing cancer cells. (2) Methods: the present narrative review presents the basic aspects of the hormonal, molecular, and cellular response to fasting, focusing on the interrelationship of fasting with oxidative stress. It also presents nonclinical and clinical evidence concerning the implementation of fasting as adjuvant to chemotherapy, highlighting current challenges and future perspectives. (3) Results: there is ample nonclinical evidence indicating that fasting can mitigate the toxicity of chemotherapy and/or increase the efficacy of chemotherapy. The relevant clinical research is encouraging, albeit still in its infancy. The path forward for implementing fasting in oncology is a personalized approach, entailing counteraction of current challenges, including: (i) patient selection; (ii) fasting patterns; (iii) timeline of fasting and refeeding; (iv) validation of biomarkers for assessment of fasting; and (v) establishment of protocols for patients’ monitoring. (4) Conclusion: prescribing fasting as anticancer medicine may not be far away if large randomized clinical trials consolidate its safety and efficacy.     

多官能团单体对聚乙烯的增感辐致凝胶效应

研究了典型的多官能团单体三羟甲基丙烷三甲基丙烯酸酯（TMPTMA）对不同种类聚乙烯辐致凝胶效应的促进作用，实验表明：多官能团单体对聚乙烯早期的辐射交联有显著的促进作用，但随着剂量的增加，作用逐渐减弱直至消失，它对聚乙烯的极限凝胶分量几乎没有贡献，这种作用对聚乙烯的品种没有选择性，依据对实验事实的分析，多官能团单体对聚乙烯辐射交联的促进机理应是：辐射引发单体聚合，在聚合的同时向大分子链频繁发生链转移，从而形成大分五－单体聚合物之间的交联网络，由于更高的剂量率能够引发更多的聚合反应动力学链，所以有助于单体对交联促进作发挥。     

环氧有机硅阳离子型光敏预聚物的合成及其光敏性能的研究

合成了环氧有机硅光敏预聚物及阳离子光引发剂甲苯茂铁四氟硼酸盐，研究光引发剂种类、预聚物与单体配比、增感剂结构等因素对固化速度的影响，发现预聚物体系的感度较高，最小感度值为165mJ/cm^2；并讨论了甲苯茂铁四氟硼酸盐的暗聚合能力。     

纳米尺寸硫化镍化学增感剂

本文发现了硫化镍纳米粒子对卤化银乳剂的化学增感作用，采用水不溶性的硫化镍纳米粒子作为化学增感剂，与水溶性的硫代硫酸钠增感剂相比，可以在乳剂灰雾增加不大的条件下明显提高乳剂的感光度和反差。     

鲁明胶介质中AgBr／I纳米粒子的生长与感光性能

本文以鱼明胶为分散介质 ,采用双注法制备AgBr/I纳米粒子乳剂 ,控制银盐与卤溶液的注入速率 (R) ,以TEM观测了粒子的生长 ,据此探讨了该乳剂中AgBr/I纳米粒子平均粒径 ( d)及分布 (±σ)与反应条件的关系 .发现在R为 1 .3mmol/min— 8mmol/min范围内 ,随R增大 , d减小 ,R d间呈良好的线性关系 .除个别外 ,±σ值变化不明显 .对于该纳米粒子乳剂采用二氧化硫脲进行化学敏化 ,结果表明 :适当增加二氧化硫脲的加入量和延长敏化时间 ,均可有效提高乳剂的感光度 ,并有助于改善其低照度互易律失效 ,此外还揭示了曝光光源色温对该乳剂感光性能的影响 .     

Hydrogenation of nitriles with iridium-triphenylphosphine complexes

Reactions of cationic iridium(I)-COD (COD = 1,5-cyclooctadiene) complexes, [Ir(COD)(PhCN)(PPh₃)]ClO₄ (1), [Ir(COD)(PPh₃)₂]ClO₄ (2) and [Ir(COD)(PhCN)₂]ClO₄ (3) with nitriles under H₂ catalytically produce primary, secondary and tertiary amines. Hydrogenation of nitriles (RCN) gives HCl salts of amines (RCH₂NH₂HCl, (RCH₂)₂NH HCl) in CH₂Cl₂. Secondary and tertiary amines seem to be produced by the reactions of RCN with primary and secondary amines, respectively under H₂ in the presence of catalysts. The hydrogenation in the presence of1 and2 is homogeneously catalyzed by soluble iridium-PPh₃ complexes formed in the reactions of1 and2 with H₂ and RCN whereas the hydrogenation in the presence of3 is heterogeneous by metallic iridium powders produced in the reduction of3 by H₂.     

含碘高氯乳剂的制备和性能研究

碘离子掺入到高氯乳剂可以显著提高其感光性能。碘离子掺入到亚表层可增加乳剂的光吸收,提高感光度,增加反差。最佳掺入量为0.6％mol/mol Ag,掺入位置在65％Ag处,KI加入速度约8s。在一定范围内(小于1.5％mol/mol Ag)碘离子掺入亚表层对清晰度没有明显影响。如果铱掺杂的掺杂位置为亚表层,掺杂量为10~(-7)mol/mol Ag,铱络合物可有效地改善含碘高氯乳剂的高照度互易律失效。     

A Dye-Sensitized Nanoporous TiO2 Photoelectrochemical Cell with Novel Gel Network Polymer Electrolyte

A novel gel network polymer electrolyte based on polysiloxane with internal plasticizing PEO chains was applied in fabricating solid-state dye-sensitized TiO₂ photoelectrochemical cells. Ethylene carbonate (EC)/propylene carbonate (PC) and LiI/I₂ were added as liquid plasticizer to improve the performance. The cells showed open circuit voltage of 0.69 V and short circuit current density of 1.7 mA cm^–2 under 28 mW cm^–2 white light illumination. The energy conversion efficiencies and fill factors of the cells were 2.9% and 0.72.