Synergistic activity between a spinach-derived natural antioxidant (NAO) and commercial antioxidants in a variety of oxidation systems

Recently, there has been great interest in the potential health benefits of foods containing polyphenols, especially from plants, due to their antioxidant content. Natural antioxidant (NAO) is a unique, powerful antioxidant which was isolated in our lab from spinach leaves. The main goal of this study was to examine potential synergistic activity in combinations of NAO and commercial antioxidants. The antioxidant activity was tested in several in vitro systems including fatty acid and fat oxidation and also in cancer cell lines. We used the unique optical live cell array (LCA) technology to monitor the generation of reactive oxygen species (ROS) in single cells over time. NAO was combined with selected commercial antioxidants, and synergistic activity that reduced ROS generation was found with three polyphenols – ferulic acid, caffeic acid, and epigallocatechin-3-gallate (EGCG). These findings demonstrate the importance of using antioxidant ‘cocktails’ which may enhance medical effects in many kinds of diseases, including cardiovascular diseases and cancer.     

Human thymidine kinase 2: molecular cloning and characterisation of the enzyme activity with antiviral and cytostatic nucleoside substrates

Based on amino acid sequence information from purified mitochondrial thymidine kinase (TK2), a cDNA of 1930 bp was cloned, containing an open reading frame encoding 232 amino acid residues starting with the N-terminal sequence determined from the native human protein preparation. Northern blot analysis with the cDNA coding region demonstrated several TK2 mRNAs, with 2 and 4 kb forms present in many tissues. We also characterised N-terminally truncated (starting at position 18) human TK2 with pharmacologically important antiviral and cytostatic nucleoside analogues. Results were highly similar to those with the native TK2 preparation. The anti-leukaemic drug arabinosyl cytosine is phosphorylated. The antitumour drug difluorodeoxycytidine and its metabolite difluorodeoxyuridine are good substrates, with K(m) values of 66 and 29 microM, respectively, and a relative Vmax of 0.6 compared to that of thymidine. Negative cooperativity was found with thymidine and the anti-HIV drug 3'-azidothymidine, but the reaction followed Michaelis-Menten kinetics with deoxycytidine, arabinosyl cytosine, and arabinosyl thymine. The results demonstrate a broad substrate specificity and complex kinetics, and suggest a role for TK2 in the activation of chemotherapeutic nucleoside analogues.     

Easy on that trigger dad: a study of long term family photo retrieval

We examine the effects of new technologies for digital photography on people’s longer term storage and access to collections of personal photos. We report an empirical study of parents’ ability to retrieve photos related to salient family events from more than a year ago. Performance was relatively poor with people failing to find almost 40% of pictures. We analyze participants’ organizational and access strategies to identify reasons for this poor performance. Possible reasons for retrieval failure include: storing too many pictures, rudimentary organization, use of multiple storage systems, failure to maintain collections and participants’ false beliefs about their ability to access photos. We conclude by exploring the technical and theoretical implications of these findings.     

Doping effect on secondary phases,microstructure and electrical conductivities of LaGaO3 based perovskites

The intermediate temperature electrolytes La_1?xSr_xGa_1?yMg_yO_3?δ (LSGM, where δ = (x + y)/2) with perovskite structure were prepared using a poly(vinyl alcohol) (PVA) solution polymerization method. Three secondary phases were identified by X-ray diffraction, LaSrGaO₄, LaSrGa₃O₇ and La₄Ga₂O₉. The relative amount of these secondary phases depended on the doping compositions. Sr doping produced more Sr rich secondary phases with increasing content, while enhanced solid solubility was observed with Mg addition. Sintered samples showed dense microstructures with well-developed equiaxed grains, and the secondary phases were mainly in the grain boundaries. LaSrGaO₄ could not be detected by SEM for the sintered pellets. The oxygen ionic conductivity was enhanced by doping with Sr and Mg. Mg doping showed the increased conductivity activation energy. La_0.8Sr_0.2Ga_0.9Mg_0.1O_2.85 had the highest ionic conductivity σ = 0.128 S/cm at 800 °C in this work.     

DIELECTRICALLY-ASSISTED DRYING OF A NONHYGROSCOPIC POROUS MATERIAL

Experiments and simulations for dielectrically-assisted drying of a nonhygroscopic material that exhibits negligible capillary moisture transfer have been conducted in order to ascertain phenomena associated with the transient drying process. Results and predictions indicate that, in general, dielectrically-assisted drying is characterized by three drying regimes. An initial regime occurs in which the material is heated convectively and dielectrically, followed by a transition regime and ultimately, a final regime during which the material is dielectrically heated and convectively cooled. During the final regime, an inverted temperature distribution in the material induces internal condensation which influences transport rates and the thermal response of the system. Measured and predicted drying histories are bracketed by algebraic expressions derived from simple energy balances under a range of conditions where volumetric dielectric heating is strong, relative to surface convective heating or cooling.     

长源距变密度测井

用长源距全波列测井资料回放的变密度图及从套管波首波提取的声幅曲线对套管井进行固井质量检查取得了比较理想的效果。实测资料说明该方法较怕幅和普通变密度测井能更准确地鉴定水泥环两个界面的胶结质量。提出了明确的鉴定标准并建议加长普通变密度测井仪的源距到７ｆｔ，尽量采用这种长源距离密度测井检查固井质量。     

Cross-Layer Communication With an Optical Packet Switched Network via a Message Injection Control Interface

Message injection control and queue management for an optical packet switched network is demonstrated via interoperation of a network with an optical interface buffer. In a time-slotted manner, cross-layer signaling is employed between the input buffer and network to dynamically reroute dropped payload packets with multiple wavelength-striped 10-Gb/s channels. At the output of the network, error-free transmission with bit-error-rates less than were confirmed, with an introduced power penalty of 3.5 dB.     

A low-noise latching comparator probe for waveform sampling applications

A new latching comparator probe is described. The probe is being developed as part of an effort to augment voltage measurement capability in the 10 Hz to 1 MHz frequency range. The probe offers an input voltage range of /spl plusmn/10 V, input impedance of 1 M/spl Omega/ and root mean square noise referred to the input as low as 55 /spl mu/V. The probe's 3-dB bandwidth is approximately 20 MHz. Total harmonic distortion is as low as -93 dB at 50 kHz. Gain flatness is within /spl plusmn/10 /spl mu/V/V from 100 Hz to 100 kHz. Improved step settling performance is achieved using a technique that minimizes circuit thermal errors. The probe's input range can be extended with a frequency-compensated 1-M/spl Omega/ input impedance attenuator allowing measurement of pulses in the microsecond regime up to 100 V. The attenuator can be compensated further with a digital filtering algorithm to achieve gain accuracy better than 100 /spl mu/V/V.     

重油强化蒸馏技术的应用

介绍一种基于石油胶体结构理论上的重油强化蒸馏新技术，实验室试验及工业应用试验表明，在减压蒸馏进料中加入微量强化剂，可提高减压蜡油（VGO）产率约1．3％，同时VGO质量得到明显改善。     

Prediction of survival with fluorine-18-fluoro-deoxyglucose and PET in head and neck cancer

The aim of this prospective study was to investigate if high uptake of 18F-fluoro-2-deoxy-D-glucose (FDG) is associated with aggressiveness in head and neck cancer and low probability of survival. METHODS: Thirty-seven patients with squamous-cell carcinoma of the head and neck underwent FDG-PET in the fasting state before cancer treatment. FDG uptake in primary tumor was quantitated as the standardized uptake value of FDG normalized to the predicted lean body mass (SUVlean, n = 37) and as the graphically determined metabolic rate for FDG (rMR[FDG], n = 34). Paraffin-embedded tumor samples were used for histologic evaluation, and expression of cytokeratin and Ki-67 antigen were assessed by immunohistochemistry. RESULTS: Interobserver agreement for the determination of quantitative uptake of FDG in tumors was excellent (r2 = 0.996, p < 0.00001), and all 37 primary tumors were visualized. A high uptake of FDG as assessed by SUVlean was associated with a higher than the median mitotic count (p = 0.01), absence of keratinization (p = 0.03), low or moderate histological grade of differentiation (p = 0.046) and advanced stage (p = 0.03), but not with Ki-67 expression (p = 0.11). The overall survival of patients with a SUVlean lower than or equal to the median value (9.0) was clearly better in univariate analysis than that of patients with a SUVlean higher than the median (3-yr survival 73% versus 22%, relative risk of death (RR) 4.2, 1.6-11.0). However, in a multivariate analysis the only independent predictors of survival were the mitotic count (RR 4.0, 1.4-11.7) and stage (3.8, 1.2-12.2). CONCLUSION: High uptake of FDG in untreated head and neck cancer is associated with advanced disease, and may portend poor survival. Aggressive treatment approaches should be considered for patients presenting with a tumor with high uptake of FDG.