7-(Dialkylamino)coumarin-4-yl]methyl-Caged Compounds as Ultrafast and Effective Long-Wavelength Phototriggers of 8-Bromo-Substituted Cyclic Nucleotides

[7-(Dimethylamino)coumarin-4-yl]methyl (DMACM) and [7-(diethylamino)coumarin-4-yl]methyl (DEACM) esters of 8-bromoadenosine 3',5'-cyclic monophosphate (8-Br-cAMP) and 8-bromoguanosine 3',5'-cyclic monophosphate (8-Br-cGMP) are described as novel caged compounds for 8-bromo-substituted cyclic nucleotides. Synthesis is accomplished by treatment of the free acids of the cyclic nucleotides with the corresponding 7(dialkylamino)-substituted 4(diazomethyl)coumarins. Irradiation of the DMACM- and DEACM-caged cyclic nucleotides with UV light stimulates the release of the cyclic nucleotides within roughly a nanosecond. The new caged compounds are resistant to hydrolysis in aqueous buffers and exhibit long-wavelength absorption properties with maxima at 400 nm, high extinction coefficients, and high quantum yields (0.15-0.31). Their favorable properties render these compounds the most efficient and rapid phototriggers of 8-bromo-substituted cyclic nucleotides known. The usefulness of the compounds for physiological studies under nondamaging light conditions was examined in HEK293 cells expressing the alpha subunit of the cyclic-nucleotide-gated (CNG) channel of cone photoreceptors (CNGA3) and of olfactory neurons (CNGA2) by using confocal laser scanning microscopy and the patch clamp technique.     

TNT和有机染料废水的光催化氧化动力学特性

利用光催化氧化技术能有效处理各类有机废水,具有高效、低选择性和不产生二次污染的特点,探讨了循环式浆态光催化反应器中有机染料和TNT模拟生产废水的光催化氧化特性以及光催化氧化动力学。基于羟基自由基生成、扩散以及羟基自由基与污染物分子的反应,建立了相应的光催化氧化动力学模型。结果表明,采用光催化氧化技术去除有机染料和TNT效果明显。光照时间为6h时,在一定的初始TNT浓度下,模拟红水中TNT去除率达90％以上。对不同染料和TNT不同初始浓度下的光催化氧化反应动力学研究表明,此过程符合拟一级动力学。所提出的光催化氧化动力学模型能够很好地描述有机染料和TNT的光催化氧化过程。     

纳米碳集聚体与纳米金刚石低填充PP的研究

采用爆炸法合成了纳米碳集聚体和纳米金刚石,将其低填充聚丙烯(PP)制备了复合材料,研究了复合材料的结晶行为和力学性能。结果表明：填充纳米粒子提高了PP的α晶态的结晶度,添加0．06％纳米碳集聚体或纳米金刚石的PP的结晶度分别提高了16．74％和25．83％;PP复合材料的拉伸强度随纳米粒子用量的增加而提高,但冲击强度下降。     

New inhibitors of the Tat-TAR RNA interaction found with a "fuzzy" pharmacophore model

TAR RNA is a potential target for AIDS therapy. Ligand-based virtual screening was performed to retrieve novel scaffolds for RNA-binding molecules capable of inhibiting the Tat-TAR interaction, which is essential for HIV replication. We used a "fuzzy" pharmacophore approach (SQUID) and an alignment-free pharmacophore method (CATS3D) to carry out virtual screening of a vendor database of small molecules and to perform "scaffold-hopping". A small subset of 19 candidate molecules were experimentally tested for TAR RNA binding in a fluorescence resonance energy transfer (FRET) assay. Both methods retrieved molecules that exhibited activities comparable to those of the reference molecules acetylpromazine and chlorpromazine, with the best molecule showing ten times better binding behavior (IC50 = 46 microM). The hits had molecular scaffolds different from those of the reference molecules.     

低压反渗透和纳滤在水的净化和脱盐中的应用

研究了低压余ESPA-1膜和纳滤UPMN-P膜的工作特点。所使用的模拟溶液中含有不同浓度的NaCl、CaCl2、CsCl和SrCl2，OPMN-P膜显示出可以减少水的硬度，而ESPA-1膜既成功地从微碱水中去除了二价离子，又成功地去除了单价离子。研究结果已经被应用于正在开发的工业设备。     

Docosahexaenoic acid supplementation in vegetarians effectively increases omega-3 index: A randomized trial

Low red blood cell (RBC) membrane content of FPA+DHA (hereafter called omega-3 index) has recently been described as an indicator for increased risk of death from coronary heart disease. The relationship between plasma and RBC FA, focusing on omega-3 index, and the response to DHA supplementation were investigated in a double-blind, randomized, placebo-controlled, intervention study. Healthy vegetarians (87 f, 17 m) consumed daily a microalgae oil from Ulkenia sp. (0.94 g DHA/d) or olive oil (placebo) for 8 wk. DHA supplementation significantly increased DHA in RBC total lipids (7.9 vs. 4.4 wt%), in RBC PE (12.1 vs. 6.5 wt%), in RBC PC (3.8 vs. 1.4 wt%), and in plasma phospholipids (PL) (7.4 vs. 2.8 wt%), whereas EPA levels rose to a much lesser extent. Microalgae oil supplementation increased the omega-3 index from 4.8 to 8.4 wt%. After intervention, 69% of DHA-supplemented subjects (but no subject of the placebo group) reached an omega-3 index above the desirable value of 8 wt%. Omega-3 index and EPA+DHA levels in RBC PE, RBC PC, and plasma PL were closely correlated (r always >0.9). We conclude that an 8-wk supplementation with 0.94 g DHA/d from microalgae oil achieves a beneficial omega-3 index of ≥8% in most subjects with low basal EPA+DHA status. RBC total FA analyses can be used instead of RBC lipid fraction analyses for assessing essential FA status, e.g., in clinical studies.     

Operating limits and features of direct air capture on K2CO3/ZrO2 composite sorbent

Potassium carbonate-based sorbents are prospective materials for direct air capture (DAC). In the present study, we examined and revealed the influence of the temperature swing adsorption (TSA) cycle conditions on the CO₂ sorption properties of a novel aerogel-based K₂CO₃/ZrO₂ sorbent in a DAC process. It was shown that the humidity and temperature drastically affect the sorption dynamic and sorption capacity of the sorbent. When a temperature at the sorption stage was 29 ℃ and a water vapor pressure in the feed air was 5.2 mbar (1 bar = 10⁵ Pa), the composite material demonstrated a stable CO₂ sorption capacity of 3.4% (mass). An increase in sorption temperature leads to a continuous decrease in the CO₂ absorption capacity reaching a value of 0.7% (mass) at T = 80 ℃. The material showed the retention of a stable CO₂ sorption capacity for many cycles at each temperature in the range. Increasing P_H2O in the inlet air from 5.2 to 6.8 mbar leads to instability of CO₂ sorption capacity which decreases in the course of 3 consecutive TSA cycles from 1.7% to 0.8% (mass) at T = 29 ℃. A further increase in air humidity only facilitates the deterioration of the CO₂ sorption capacity of the material. A possible explanation for this phenomenon could be the filling of the porous system of the sorbent with solid reaction products and an aqueous solution of potassium salts, which leads to a significant slowdown in the CO₂ diffusion in the composite sorbent grain. To investigate the regeneration step of the TSA cycle in situ, the macro ATR-FTIR (attenuated total reflection Fourier-transform infrared) spectroscopic imaging was applied for the first time. It was shown that the migration of carbonate-containing species over the surface of sorbent occurs during the thermal regeneration stage of the TSA cycle. The movement of the active component in the porous matrix of the sorbent can affect the sorption characteristics of the composite material. The revealed features make it possible to formulate the requirements and limitations that need to be taken into account for the practical implementation of the DAC process using the K₂CO₃/ZrO₂ composite sorbent.     

燃煤工业锅炉的干法排烟脱硫装置——燃煤工业锅炉上安装的第一套工业化的干法排烟脱 硫装置,到1982年春,其运行时间已超过2万小时,运转效率大于97％。

1978年9月,Hammermill Paper公司与Mikropul有限公司签订了一项建造一套干法排烟脱硫装置的合同。这套干法排烟脱硫装置,安装在麻萨诸塞州沃罗诺柯Strathmore Paper公司燃煤锅炉上,该锅炉是由