Frontal Chromatography of Proteins: The Effect on Column Performance of the Restricted Diffusion of Molecules in Porous Chromatographic Adsorbents

A theoretical formulation is presented that can be used to describe the dynamic behavior of frontal chromatography of proteins in columns packed with adsorbent particles in which restricted pore diffusion of the adsorbate molecules occurs. The results of this work clearly indicate that the time for breakthrough and the effective utilization of the adsorptive capacity of the chromatographic particles increase as (a) the size of the adsorbate and/or ligand (active site) molecule decreases, (b) the pore connectivity, n(T), of the porous network of the adsorbent particles increases, and (c) the column length, L, increases. Copyright (C) 1998 Elsevier Science B.V

Electrocatalytic oxidation of moxifloxacin hydrochloride on modified glassy carbon surface and determination in Avelox tablets

This work presents an electroanalytical method for the determination of moxifloxacin hydrochloride (MOX) in tablets. The surface of the glassy carbon electrode (GCE) was modified by electrochemical polymerization of 4-aminobenzene sulfonic acid in phosphate buffer solution (pH 7.0).The oxidative behavior of MOX was studied at glassy carbon and modified glassy carbon electrodes in different buffer systems using the cyclic voltammetry technique. The modified glassy carbon electrode (poly(4-ABSA/GCE) has very high catalytic ability for electrooxidation of MOX. Acetate buffer (pH 5.0) was selected as the optimum medium for the oxidation of MOX at poly(4-ABSA/GCE) due to the highest electronic signal increase obtained. Differential pulse voltammetry (DPV) and chronoamperometry (CA) techniques were used for voltammetric determination of MOX. The values of limit of detection (LOD) and limit of quantification (LOQ) were determined to be 3.19×10 -7 M and 1.06×10 -6 M for DPV; and 5.50×10 -7 M and 1.83×10 -6 M for CA, respectively. A highly sensitive electroanalytical method for the determination of MOX in Avelox tablets by DPV was described. © 2019 Bulgarian Academy of Sciences, Union of Chemists in BulgariaGaziosmanpasa University Scientific Research Fund, (2016/76); Gaziosmanpasa Üniversites

Health and health belief factors associated with screening and help-seeking behaviours for breast cancer symptoms: a systematic review and meta-analysis of the European evidence

Purpose: The aim of this systematic review was to identify health or health belief factors associated with mammography attendance or with self-initiated medical help-seeking for breast cancer symptoms among women in Europe. Methods: Five databases were searched for articles published between 2005 and 2018. Meta-analyses were conducted for 13 factors related to screening attendance and two factors associated with help-seeking behaviour. Where there were too few studies to include in the meta-analysis a narrative synthesis was undertaken. Results: Sixty-five studies were included. Never having had cervical screening (d=-0.72, p<0.001) and higher perceived barriers to mammography (d=-0.40, p<0.001) were associated with lower levels of screening attendance. Possessing health insurance (d=0.49, p<0.001), greater perceived benefits (d=0.31, p<0.001) and motivation (d=0.36, p=0.003) towards screening, and higher perceived seriousness (d=0.24, p=0.019) and susceptibility (d=0.20, p=0.024) towards breast cancer were associated with a higher level of screening attendance. Presenting with a non-lump symptom was associated with a longer time to presentation (d=0.32, p<0.001). The narrative synthesis revealed that previous benign breast disease was associated with a higher level of screening attendance but with a longer time to presentation. Conclusions: The review identified key similarities in factors associated with screening and help-seeking behaviours which offer scope for combined interventions aimed at women that target both behaviours. Furthermore, the review highlighted that fewer studies have focused on help-seeking behaviour, despite two thirds of breast cancer cases being self-detected. Future research should further examine predictors of help-seeking behaviour including a focus on modifiable factors, such as BMI, and physical activity

Innovation capability and its role in enhancing the relationship between TQM practices and innovation performance

Innovation plays a critical role in predicting the long-term survival of organizations, determining an organization’s success and sustaining its global competitiveness, especially in an environment where technologies, competitive position and customer demands can change almost overnight, and where the life-cycle of products and services are becoming shorter.Therefore, the main purpose of this paper is to extend the existing knowledge as to the relationship between TQM practices and innovation performance by exploring the expected role of innovation capability as mediator to enhance this relationship.At the same time, this study attempted to shed a light on how to improve innovation performance of manufacturing companies in Malaysia.The gained results indicated that innovation capability mediates the relationship between TQM practices and innovation performance. More importantly, this study supports the findings of the past studies that questioned the role of TQM practices in improving innovation performance. Finally, in light of the obtained results, several recommendations were introduced to assist decision makers in manufacturing companies

Stabilization of galvanic sludge by microwave pre-treated pyrolysis

The study was aimed examine the effect of microwave preheated pyrolysis on the characteristics of volatile metal compounds. In order to monitor the behavior of volatile metals, samples were preheated with microwave oven in varying energy ranges and process durations. In order to determine optimum conditions, 360-, 600- and 900-W microwave power and 3-, 5- and 10-min microwave irradiation were used. Chemical analyses of samples were carried out both before and after experiments by X-ray fluorescence. Pyrolysis experiments were performed in a laboratory-scale fixed-bed updraft stainless steel reactor in the presence of 1 L min(-1) N-2 gas. Content of synthetic gas product obtained via pyrolysis was analyzed by a continuous gas analyzer. Microwave preheated pyrolysis resulted an increase in the weight percentage of calcium oxide, iron(III) oxide, and chromium(III) oxide in galvanic sludge. Similar changes were determined for most of the samples at 600 W and 5 min of microwave preheated pyrolysis. In this point, the weight percentage of calcium oxide, iron(III) oxide, and chromium(III) oxide were measured as 22.47, 16.93, and 5.63 wt% which were 19.86, 10.89, and 3.03 wt% after single pyrolysis. It is concluded that, future analysis are needed to increase the efficiency of stabilization by microwave preheated pyrolysis

Dynamic Pressure Rise in the Drying Chamber as a Remote Sensing Method for Monitoring the Temperature of the Product during the Primary Drying Stage of Freeze Drying

A novel dynamic pressure rise method is developed as a remote sensing procedure for determining at different times during the primary drying stage of the freeze drying process (i) the temperature of the moving interface between the dried and frozen layers of the product (ii) the temperature close to the upper surface of the dried layer of the product, (iii) the temperature of the bottom surface of the frozen layer of the product, and (iv) the temperature profile of the frozen layer of the product. Furthermore, by knowing the temperature of the heating plate and determining the value of the temperature of the moving interface from the dynamic pressure rise method, the value of the position of the moving interface could be determined by an expression presented in this work