Effects and properties of poly(arylene ether benzonitrile)s of various molecular weights blended with sulfonated poly(ether ether ketone)

Poly(arylene ether benzonitrile) (PAEBN) was synthesized with 2,6‐dichlorobenzonitrile and biphenol. PAEBNs with various molecular weights (MWs), 1,640,000 and 185,000 g/mol, were synthesized by control of the stoichiometry of the monomers and were blended with sulfonated poly(ether ether ketone) (SPEEK). The effects of MW on the water uptake, swelling, methanol permeability, and proton conductivity of the SPEEK/PAEBN blend membranes were investigated. The molecular mobility of the SPEEK/PAEBN blends was also examined in this study. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

A Multisite Comparison of Actuarial Risk Instruments for Sex Offenders.

Four actuarial instruments for the prediction of violent and sexual reoffending (the Violence Risk Appraisal Guide [VRAG], Sex Offender Risk Appraisal Guide [SORAG], Rapid Risk Assessment for Sex Offender Recidivism [RRASOR], and Static-99) were evaluated in 4 samples of sex offenders (N = 396). Although all 4 instruments predicted violent (including sexual) recidivism and recidivism known to be sexually motivated, areas under the receiver operating characteristic (ROC) were consistently higher for the VRAG and the SORAG. The instruments performed better when there were fewer missing items and follow-up time was fixed, with an ROC area up to .84 for the VRAG, for example, under such favorable conditions. Predictive accuracy was higher for child molesters than for rapists, especially for the Static-99 and the RRASOR. Consistent with past research, survival analyses revealed that those offenders high in both psychopathy and sexual deviance were an especially high-risk group. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

与客户建立互惠互利长期稳定的营销关系

在我国加入WTO之后，国内钢铁企业与经销商之间如何实现互惠互利，并建立起长期稳定的营销关系。     

大型软件缺陷修正跨国外包后的质量控制

研究了大型软件A93K SOC Series 93000缺陷修正在跨国外包后的质量控制问题,提出了采用缺陷跟踪和缺陷检查的解决方案;并通 过缺陷修正数量和工作流服务质量等指标的分析,论证了CRT(Customer Response Team)质量控制的有效性;得到了综合评价缺陷修正质量控 制成效的一个重要技术指标,即缺陷修正比率FROC(Fixing Rate of CR)。     

碳铬镍含量对高铬铸铁测温保护管性能的影响

通过高温氧化和高温磨损实验,研究了C、Cr、Ni 3个主要元素对高铬铸铁在高温条件下抗氧化和抗磨损性能的影响。结果表明:Cr含量越高,抗氧化性能和抗磨损性能越好;提高碳含量,明显提高高铬铸铁的高温抗磨性能;当w(Cr)=16％时,加入Ni能提高高铬铸铁的高温抗氧化性能;w(Cr)=30％时,Ni对高铬铸铁的抗氧化性能和抗磨损性能影响不明显.在1100℃以下,选用w(C)=2.8％,w(Cr)=30％、不加Ni的高铬铸铁铸造高温抗磨热电偶保护管,既有较好的使用寿命,又可降低成本.     

国内外拉伸型干酪的种类及研究进展

概述了拉伸型干酪的种类、工艺,以及国外拉伸型干酪的研究进展.同时研讨了我国少数民族传统拉伸型干酪-乳扇的生产历史、工艺、研究情况,以及与国外传统拉伸型干酪的比较;并介绍了国内对Mozzarella干酪的研究进展.     

Glucuronidation of N-hydroxy heterocyclic amines by human and rat liver microsomes

The food-borne carcinogenic and mutagenic heterocyclic aromatic amines undergo bioactivation to the corresponding N-hydroxy (OH)-arylamines and the subsequent N-glucuronidation of these metabolites is regarded as an important detoxification reaction. In this study, the rates of glucuronidation for the N-OH derivatives of 2-amino-3-methylimidazo[4,5-f]-quinoline (IQ), 2-amino-1-methyl-6-phenylimidazo[4,5-b]-pyridine (PhIP), 2-amino-6-methyl-dipyrido[1,2-a:3',2'-d]imidazole (Glu-P-1) and 2-amino-3,8-dimethylimidazo[4,5-f]quinoxaline (MeIQx) by liver microsomal glucuronosyltransferase were compared to that of the proximate human urinary bladder carcinogen, N-OH-aminobiphenyl (N-OH-ABP) and the proximate rat colon carcinogen N-OH-3,2'-dimethyl-4-amino-biphenyl (N-OH-DMABP). Human liver microsomes catalyzed the uridine 5'-diphosphoglucuronic acid (UDPGA)-dependent glucuroidation of N-OH-IQ, N-OH-PhIP, N-OH-Glu-P-1 and N-OH-MeIQx at rates of 59%, 42%, 35% and 27%, respectively, of that measured for N-OH-ABP (11.5 nmol/min/mg). Rat liver microsomes also catalyzed the UDPGA-dependent glucuronidation of N-OH-PhIP, N-OH-Glu-P-1 and N-OH-IQ at rates of 30%, 20% and 10%, respectively of that measured for N-OH-DMABP (11.2 nmol/min/mg); activity towards N-OH-MeIQx was not detected. Two glucuronide(s) of N-OH-PhIP, designated I and II, were separated by HPLC. Conjugate II was found to be chromatographically and spectrally identical with a previously reported major biliary metabolite of PhIP in the rat, while conjugate I was identical with a major urinary metabolite of PhIP in the dog. Hepatic microsomes from rat, dog and human were found to catalyze the formation of both conjugates. The rat preferentially formed conjugate II (I to II ratio of 1:15), while the dog and human formed higher relative amounts of conjugate I (I to II ratio of 2.5:1.0 and 1.3:1.0 respectively). Fast atom bombardment mass spectrometry of conjugates I and II gave the corresponding molecular ions and showed nearly identical primary spectra. However, collision-induced spectra were distinct and were consistent with the identity of conjugates I and II as structural isomers. Moreover, the UV spectrum of conjugate I exhibited a lambda max at 317 nm and was essentially identical to that of N-OH-PhIP, while conjugate II was markedly different with a lambda max of 331 nm. Both conjugates were stable in 0.1 N HCl and were resistant to hydrolysis by rat, dog and human liver microsomal beta-glucuronidases.(ABSTRACT TRUNCATED AT 400 WORDS)     

A convenient method to discriminate between cytochrome P450 enzymes and flavin-containing monooxygenases in human liver microsomes

Liver microsomes are a frequently used probe to investigate the phase I metabolism of xenobiotics in vitro. Structures containing nucleophilic hetero-atoms are possible substrates for cytochrome P450 enzymes (P450) and flavin-containing monooxygenases (FMO). Both enzymes are located in the endoplasmatic reticulum of hepatocytes and both need oxygen and NADPH as cofactors. The common method to distinguish between the two enzyme systems is to use the thermal inactivation of FMO and to inhibit P450 completely with carbon monoxide, N-octylamine or N-benzylimidazole. In the literature no indication could be found that the heat inactivation of FMO does not affect any of the human P450 enzymes or that the overall P450 inhibitors inhibit the different human P450 enzymes sufficiently and do not affect the FMO. The effect of N-benzylimidazole and heat inactivation was tested on specific activities of seven P450 enzymes in human liver microsomes, 1A2, 2A6, 2C9, 2C19, 2D6, 3A4/5, and 2E1, using methoxyresorufin O-demethylation, coumarin 7-hydroxylation, (S)-warfarin 4-hydroxylation, (S)-(+)-mephenytoin 4-hydroxylation, dextrometorphan O-demethylation, oxidation of denitronifedipine, and chlorzoxazone 6-hydroxylation respectively. The sulfoxidation of methimazole (MMI) was used as a specific probe for the determination of FMO activity. Methimazole sulfoxidation was compared with the well known assay for FMO metabolism, the formation of N,N-dimethylaniline (DMA) N-oxide, to be confirmed as an exclusively FMO mediated reaction. The participation of P450 and FMO in the sulfoxidation of four sulfur containing peptides, ametryne; terbutryne, prometryne and methiocarb was investigated using human liver microsomes. All four reactions were demonstrated to be catalysed predominantly by cytochrome P450.     

Noninvasive assessment of the direct action of oral nifedipine and nicardipine on left ventricular contractile state in patients with systemic hypertension: importance of reflex sympathetic responses

BACKGROUND: Alveolar macrophages from patients with sarcoidosis were analyzed for their ability to secrete tumor necrosis factor-alpha (TNF-alpha), interleukin-1-beta (IL-1-beta), and interleukin-6 (IL-6). RESULTS: Constitutive release of all three monokines in these patients was concomitantly increased in the active state of disease in comparison with inactive sarcoidosis or healthy control subjects. Alveolar macrophages from patients with inactive sarcoidosis compared with cells from healthy subjects showed increased spontaneous secretion of TNF-alpha and IL-6 only, whereas the constitutive release of IL-1-beta was similar as in healthy volunteers. In vitro stimulation of alveolar macrophages from healthy control subjects with lipopolysaccharide or pokeweed mitogen led to a time- and dose-dependent enhanced secretion of TNF-alpha, IL-1-beta, and IL-6. In a similar manner, with corresponding cells from patients with sarcoidosis the secretion of all three cytokines could be further increased by stimulation with lipopolysaccharide or pokeweed mitogen. CONCLUSIONS: The data presented indicate that an increased release of TNF-alpha, IL-1-beta, and IL-6 correlates to disease activity and may play a critical part in the pathogenesis of sarcoidosis.