Spatial and temporal control of microwave triggered chemiluminescence: a protein detection platform

We have combined the principles of microwave circuitry and antenna design and our recent work in microwave-triggered metal-enhanced chemiluminescence to now "trigger" chemically and enzyme-catalyzed chemiluminescent reactions with spatial and temporal control. With this technology platform, we achieve spatial and temporal control of enzyme and chemically catalyzed chemiluminescence reactions to achieve more than 500-fold increases in "on-demand" photon flux from chemically catalyzed chemiluminescent reactions. We also report a 6-fold increase in photon flux from HRP-catalyzed assays on disposable coverslips functionalized with HRP and placed proximal to the substrates modified with thin-film aluminum triangle disjointed "bow-tie" structures. In addition, we demonstrate the applicability of this technology to develop multiplexed or high-throughput chemiluminescent assays. We also demonstrate the clinical and biological relevance of this technology platform by affixing aluminum structures in proximity to HRP protein immobilized on nitrocellulose to improve the sensitivity for this model Western blot scheme by 50-fold. We believe analytical applications that rely on enzyme-catalyzed chemiluminescence, such as immunoassays, may greatly benefit from this new platform technology.     

成革固体废弃物中重金属毒性测定的研究

本文主要研究对象是皮革制品中对生态体系有害的重金属毒性。采用电感耦合等离子体发射仪（ICP-OES）测定皮革样品中的重金属浓度,重金属的毒性是采用MetPLATE生物测定法。在铬盐和铝盐鞣制的成革中,铬和铝占到重金属总浓度的98％,而在一些植鞣革中,锆是检测到的唯一重金属。铬鞣革、铝鞣革以及植鞣革的平均抑制值分别为98．08％、97．04％和62．36％。     

Surface plasmon coupled fluorescence in the ultraviolet and visible spectral regions using zinc thin films

The use of zinc thin films deposited onto glass supports for surface plasmon coupled fluorescence (SPCF) over a broad 200 nm wavelength range is demonstrated. Fresnel calculations performed in the ultraviolet and visible spectral range are predicted to generate surface plasmon modes in 30 nm zinc thin films. In this spectral range, the extent of coupling of light to zinc thin films was shown to be significant as compared to similar aluminum, gold, and silver thin films. The experimental demonstration of SPCF using 30 nm zinc thin films in the ultraviolet and visible spectral regions was undertaken using three different fluorophores 2-AP, POPOP, and FITC, respectively. Surface plasmon coupled fluorescence from zinc thin films was p-polarized and highly directional with lambda max conferred at an angle of 58, 68, and 60 degrees for FITC, POPOP, and 2-AP, respectively. s-Polarized emission from zinc thin films was negligible for all fluorophores except for a sample spin coated from a 10% PVA solution, which resulted in significant s-polarized emission due to the generation of waveguide modes. The experimental results are consistent with reflectivity curves that are theoretically predicted using Fresnel calculations. Given the growing use and utility of plasmon-enhanced fluorescence in the analytical and biological sciences, our findings will serve as a useful tool for workers in the ultraviolet and visible spectral regions.     

Low Temperature Plasma for decontamination of E. coli in milk

Raw milk is a natural, highly nutritious product and a quick and easy supplement for human dietary requirements. Elimination of bacteria in milk has been a problem for decades and new methods with regards to non-thermal applications which do not harm the chemical composition of milk, are currently under investigation. The objective of the study was to determine the potential use of a novel, Low Temperature Plasma (LTP) system for its capability of killing Escherichia coli in milk with different fat contents. The time dependent effect of atmospheric corona discharge generated with 9kV of AC power supply on E. coli ATCC 25922 dispersed in whole, semi skimmed and skimmed milk was examined. Plasma was applied at time intervals of 0, 3, 6, 9, 12, 15 and 20min. A significant 54% reduction in the population of E. coli cells after only 3min was observed regardless of the fat content of the milk. The initial pre-plasma bacterial count of 7.78 Log CFU/ml in whole milk was decreased to 3.63 Log CFU/ml after 20min of plasma application. LTP did not cause any significant change to the pH and color values of raw milk samples. No viable cells were detected after one week examination in whole milk samples and remained so over the 6week storage period. The findings of this study show that the novel LTP system tested was able to significantly reduce E. coli in milk by more than a 3 fold log reduction without significantly affecting pH or color properties.     

Mathematical Modeling of Carbon Content and Intercritical Annealing Temperature in DP Steels by Factorial Design Method

2k factorial design is employed to find the mathematical relation between the carbon content and intercritical annealing temperature （IAT） in order to predict the responses namely martensite volume fraction （MVF）, microhardness （H）, yield strength （YS）, ultimate tensile strength （UTS）, total elongation （TEL）, yield ratio （YR） and Charpy impact energy （CIE） in dual phase （DP） steels. Steels containing different carbon contents （0.085% C and 0.380% C） had been chosen for this purpose. The main advantages of factorial design are its easy implementation and the effective computation compared with the other optimization techniques, which were employed for predicting mentioned responses in the literature. To verify the proposed approach based on factorial design, experiments for verification were performed. The results of the verification experiments and the mathematical models are in accordance with each other and the literature.     

纳米技术在软化工序中的应用

在传统的软化工序中,为了除去无用残留物,通常使用从猪或牛胰腺中分离提取的的胰酶。一般来说,软化工序结束后,浴液的酶不能重复利用,被排放到废水中。由于这些错误,软化工序增加了额外的废水处理费用。纳米粒子有较大的表面积和较自己的体重高数百倍的结合容量。他们也可以通过染料载体使用非纤维蛋白的吸附。通过这种方式,我们研究了染料亲和纳米颗粒代替酶软化过程。在这项研究中,p(HEMA)(2-羟基乙基甲基丙烯酸酯)纳米颗粒通过表面活性剂乳液自由聚合产生。P(HEMA)纳米粒子的特性通过傅里叶变换红外光谱(FTIR)和扫描电子显微镜(SEM)表征。三嗪染料活性红120通过化学方法附加到p(HEMA)纳米粒子。这些染料包含p(HEMA)-活性红120具有亲和力的纳米颗粒,用于在水溶液中非纤维蛋白质的吸附。此外优化了p(HEMA)-活性红120在间歇反应器的实验条件和其吸附容量。结果证明了纳米颗粒的可重用性和其作为软化剂的有效性。因此,和软化工序中的酶相比,p(HEMA)-活性红120纳米粒子是一种环境友好的、廉价的、可重复使用的材料。     

严重干旱迫使土耳其减少向叙利亚供水

严重干旱迫使土耳其将幼发拉底河向下游叙利亚的流量减少到接近协议水平的一半。按照协议幼发拉底河向叙利亚的供水量应为 50 0ｍ3/ｓ ,到 2 0 0 0年 9月已降至 30 0ｍ3/ｓ ,这种情况可能要持续到2 0 0 1年 3月。由于降雨少 ,严重干旱 ,使土耳其建在幼发拉底河上的水电站发电量锐减 ,且使土耳其无法根据 1984年与叙利亚达成的双边协议向叙利亚供水 50 0ｍ3/ｓ。干旱使水库水位下降到 10ａ来最低水位 ,而土耳其电力需求的增长 ,能源部门未作足够的投资造成严重缺电。土耳其最大 ,世界第 6大的阿塔图克坝 ,水位降至 52 6.6ｍ ,只比死水位高60…     

DASH questionnaire for the analysis of musculoskeletal symptoms in industry workers: a validity and reliability study

Purpose

The disabilities of the arm, shoulder and hand (DASH) questionnaire is a self-administered region-specific outcome instrument developed as a measure of self-rated upper-extremity disability and symptoms. The aim of this study was to evaluate the reliability and the construct validity of the DASH questionnaire by establishing its correlation to the Medical Outcomes Study Short Form-36 (SF-36) in industry workers. Also we aimed to investigate whether the DASH can be used as a standardized questionnaire to evaluate the work-related musculoskeletal disorders (WMSDs) in upper extremity in industrial settings and epidemiological studies.

Material and methods

The Turkish version's reliability and construct validity were evaluated in 240 industry workers with upper-extremity musculoskeletal complaints. Workers were asked to complete a packet that included the DASH and the SF-36. Test-retest reliability was assessed in all workers who filled in the DASH questionnaire 15 days later. Construct validity was evaluated by comparing the overall and work component DASH scores with SF-36 summary and subscales.

Results

The mean DASH score for the textile workers whose duties were confection, dyeing, sewing, quality control and packaging was calculated as 65, 55, 68, 54 and 67, respectively. As a result of this study, pain intensity in shoulder, wrist and hand was significantly associated with the DASH score (p<0.05). Internal consistency of the DASH was high (Cronbach alpha 0.91). Test-retest reliability was excellent for the overall DASH (intraclass correlation coefficient (ICC) 0.92). Moderate correlations (p<0.05) were found between the overall and work component DASH and the SF-36 summary scales. Pearson correlation coefficients of the overall and work component DASH to the SF-36 subscales ranged from −0.33 to −0.82.

Conclusion

These results support that DASH is a reliable and valid instrument to measure functional disability and investigate the ergonomic risk factors in textile workers with upper-extremity musculoskeletal complaints.     

Nanomechanical characterization by double-pass force-distance mapping

We demonstrate high speed force-distance mapping using a double-pass scheme. The topography is measured in tapping mode in the first pass and this information is used in the second pass to move the tip over the sample. In the second pass, the cantilever dither signal is turned off and the sample is vibrated. Rapid (few kHz frequency) force-distance curves can be recorded with small peak interaction force, and can be processed into an image. Such a double-pass measurement eliminates the need for feedback during force-distance measurements. The method is demonstrated on self-assembled peptidic nanofibers.