TNT-RDX混合废水处理的实验研究——生物-吸附法

介绍了在２５￣３５℃的温度下，用厌氧－兼氧－水生生物－吸附组合工艺处理ＴＮＴ和ＲＤＸ混合废水的方法，进行了日处理量为６０￣９００Ｌ的实验室放大实验。当ＴＮＴ和ＲＤＸ混合废水总浓度为４￣１２ｍｇ／Ｌ时，经过该工艺处理后可达到国家排放标准。其中厌氧－兼氧能去除废水中８０％以上的ＴＮＴ和ＲＤＸ，水生生物（水葫芦）对ＴＮＴ及ＲＤＸ也有一定的降解效果，最后用活性炭吸附可以实现深度处理。     

Identification and molecular characterization of two tandemly located flagellin genes from Aeromonas salmonicida A449

Two tandemly located flagellin genes, flaA and flaB, with 79% nucleotide sequence identity were identified in Aeromonas salmonicida A449. The fla genes are conserved in typical and atypical strains of A. salmonicida, and they display significant divergence at the nucleotide level from the fla genes of the motile species Aeromonas hydrophila and Aeromonas veronii biotype sobria. flaA and flaB encode unprocessed flagellins with predicted Mrs of 32,351 and 32,056, respectively. When cloned under the control of the Ptac promoter, flaB was highly expressed when induced in Escherichia coli DH5alpha, and the FlaB protein was detectable even in the uninduced state. In flaA clones containing intact upstream sequence, FlaA was barely detectable when uninduced and poorly expressed on induction. The A. salmonicida flagellins are antigenically cross-reactive with the A. hydrophila TF7 flagellin(s) and evolutionarily closely related to the flagellins of Pseudomonas aeruginosa and Vibrio anguillarum. Electron microscopy showed that A. salmonicida A449 expresses unsheathed polar flagella at an extremely low frequency under normal laboratory growth conditions, suggesting the presence of a full complement of genes whose products are required to make flagella; e.g., immediately downstream of flaA and flaB are open reading frames encoding FlaG and FlaH homologs.     

Underrecognition of cervical Neisseria gonorrhoeae and Chlamydia trachomatis infections in the emergency department

OBJECTIVES: 1) To quantify the frequency of underrecognized Neisseria gonorrhoeae and Chlamydia trachomatis cervical infections in women tested in the ED, 2) to describe and compare the characteristics of those treated and not treated during the initial visit, and 3) to quantify the delay interval until treatment was provided. METHODS: A 2-year, retrospective consecutive case series was performed from June 1, 1992, to May 31, 1994. There were 148 women with > or = 1 discrete occurrence of culture-proven cervical N. gonorrhoeae or C. trachomatis infection studied. All the patients were evaluated in a university-affiliated, tertiary care hospital-based ED with a large rural referral area. The main outcome measures were the proportions of patients with positive cultures both treated and not treated in the ED, the clinical characteristics of each group, and the proportion remaining untreated or experiencing treatment delays of > 2 weeks after attempted phone, mail, and public health follow-up. RESULTS: Of 157 occurrences of positive cultures for N. gonorrhoeae or C. trachomatis, 86 (53%) were treated with a regimen suggested by the CDC prior to ED release. The proportion of women with isolated C. trachomatis infections that were underrecognized and untreated initially was larger than the proportions with isolated N. gonorrhoeae or combined infections (79% vs 27% and 53%, respectively, p < 0.0001). Women with findings suggestive of advanced disease (history of fever or chills, or examination evidence of temperature > 38 degrees C, purulent vaginal discharge, or any uterine/salpinx/ovarian tenderness) were more often recognized and treated with appropriate antibiotics initially (p = 0.02 to < 0.00001 for all). After phone, mail, and public health follow-up, treatment could not be documented for 25% of the occurrences, in all cases due to an inability to locate the patient. An additional 20% of the women did not receive treatment for 14-60 days. CONCLUSIONS: In this population, both N. gonorrhoeae and C. trachomatis cervical infections are frequently underrecognized in the ED, with isolated C. trachomatis infections associated with significantly higher proportions of underrecognition. Many affected women remain untreated for extended intervals, creating public and individual health risks. Improved point of contact detection, follow-up, and treatment policies are needed to limit these risks.     

ACAT inhibitors derived from hetero-Diels-Alder cycloadducts of thioaldehydes

Acyl-CoA:cholesterol acyltransferase (ACAT) is the enzyme largely responsible for intracellular cholesterol esterification. A systemic inhibitor of ACAT is believed to be able to slow or even reverse the atherosclerotic process. Towards that goal, a series of cyclic sulfides, derived from the hetero-Diels-Alder reaction of thioaldehydes with 1,3-dienes, and bearing carboxamide substituents, were prepared and evaluated for in vitro (in several tissues and species) and ex vivo ACAT inhibition. Minor changes in subsequent structure were found to have a significant effect in optimization of the biological activity of this series of compounds.     

金属蒸气法制备聚合物固载Pd－Cu双金属原子簇

为了不使用任何还原剂而获得聚合物固载高分散零价双金属加氢催化剂，利用金属蒸气法制备了３种不同Ｐｄ／Ｃｕ质量比的聚合物固载双金属原子簇。透射电镜（ＴＥＭ）和Ｘ衍射（ＸＲＤ）测定表明，Ｐｄ－Ｃｕ原子簇粒度很小，平均直径小于３．０ｎｍ。Ｘ射线光电子能谱（ＸＰＳ）表明，Ｐｄ和Ｃｕ均为零价态。Ｐｄ－Ｃｕ原子簇在异丙叉加氢反应中具有很高的活性和选择性。这些结果提供了令人信服的证据，即金属蒸气法可用于在聚合物孔穴内直接而温和地置入小的零价金属原子簇，而且这样制备的聚合物固载金属原子簇很适合于催化应用。     

高阻带抑制有源声表面波滤波组件

介绍有源声表面波滤波组件的设计思路。报道最新研制的高性能滤波组件，其中心频率４０ＭＨｚ，３ｄＢ相对带宽０．８％，阻带抑制优于１００ｄＢ，矩形系数（Δｆ１００ｄＢ／Δｆ３ｄＢ）小于３，输入输出端口电压驻波比接近１。组件体积８５ｍｍ×３５ｍｍ×２４ｍｍ，重量小于１１５ｇ     

Synthesis and cytotoxicity of potential tumor-inhibitory analogues of trimelamol (2,4,6-tris[(hydroxymethyl)methylamino]-1,3,5-triazine) having electron-withdrawing groups in place of methyl

In exploring the structural features which determine the antitumor activity of 2,4,6-tris-[(hydroxymethyl)methylamino]-1,3,5-triazine (trimelamol, 1), we have synthesized analogues in which the methyl groups have been replaced by the electron-withdrawing substituents 2,2,2-trifluoroethyl (5), propargyl (13), and cyanomethyl (15) via the respective tris(alkylamino)triazines 3, 12, and 14. Three mono[(hydroxymethyl)amino]triazines (4, 7, and 10) were also prepared. All the new tris(hydroxymethyl) derivatives showed cytotoxicities toward a variety of experimental rodent and human ovarian tumor cell lines similar to those shown by 1, the cyanomethyl analogue (15) having the most favorable profile. Mono(hydroxymethyl) derivatives (4 and 7) were ca. one-third as toxic. The new tris(hydroxymethyl) analogues were more stable to aqueous hydrolysis than was 1. Half-life (pH 7.5) values were, for 1, 120 min, for 5, 690 min, for 13, 450 min, and for 15, 275 min, but at pH 2.0, 15 (t1/2 350 min) was the most stable. This cyanomethyl analogue was also the most water-soluble, being comparable to 1 whereas 5 and 13 were poorly soluble.     

Adverse environmental conditions in the respiratory and medical ICU settings

Sleep deprivation and fragmentation occurring in the hospital setting may have a negative impact on the respiratory system by decreasing respiratory muscle function and ventilatory response to CO2. Sleep deprivation in a patient with respiratory failure may, therefore, impair recovery and weaning from mechanical ventilation. We postulate that light, sound, and interruption levels in a weaning unit are major factors resulting in sleep disorders and possibly circadian rhythm disruption. As an initial test of this hypothesis, we sampled interruption levels and continuously monitored light and sound levels for a minimum of seven consecutive days in a medical ICU, a multiple bed respiratory care unit (RCU) room, a single-bed RCU room, and a private room. Light levels in all areas maintained a day-night rhythm, with peak levels dependent on window orientation and shading. Peak sound levels were extremely high in all areas representing values significantly higher than those recommended by the Environmental Protection Agency as acceptable for a hospital environment. The number of sound peaks greater than 80 decibels, which may result in sleep arousals, was especially high in the intensive and respiratory care areas, but did show a day-night rhythm in all settings. Patient interruptions tended to be erratic, leaving little time for condensed sleep. We conclude that the potential for environmentally induced sleep disruption is high in all areas, but especially high in the intensive and respiratory care areas where the negative consequences may be the most severe.     

More investigations of leakage and nonleakage conductor-backedcoplanar waveguide

Through rigorous full-wave analysis, the effective dielectric constant, normalized attenuation constant, characteristic impedance, and radiation pattern of two types of conductor-backed coplanar waveguides are obtained. The analytic results show that the leakage effect is not only controlled by the thickness and dielectric constant of the substrate but also by the slot width. The leakage power transforms to a radiation space wave and a surface wave, the transverse electric field diagrams in the substrate and the far-zone radiation pattern verify the leakage phenomenon. The first structure has the maximum radiation intensity in the endfire direction, while the second one which has more leaky waves radiates into the air, is better served as a radiating device. For both structures under the nonleakage condition, the characteristic impedance is sensitive to the change of the strip width but not the slot width. Using these properties, the nonleaky and leaky circuits can exist on the same circuit board by choosing appropriate circuit dimensions