Introduction: Streptococcus pyogenes causes a variety of infectious and non-infectious diseases. Typing of S. pyogenes isolates is one of the essential tools in the epidemiological studies of this bacterium. Random Amplified Polymorphic DNA (RAPD) is a rapid, easy and inexpensive PCR-based typing technique. Low reproducibility of RAPD-PCR is the main disadvantage of this method which will be resolved by optimization of RAPD-PCR protocol. Materials and methods: In this study, optimization of RAPD-PCR protocol including DNA extraction method, primer type, concentrations of PCR reagents, and PCR program was performed using the FACTORIAL DESIGN of experiments for S. pyogenes ATCC 19615 as a standard strain. Then, sixteen S. pyogenes isolates were genotyped by using optimized protocol. Typability, reproducibility, and discriminatory power of the optimized protocol were examined. Results: Among three DNA extraction methods and seven primers that were used, modified set buffer DNA extraction method and P14 primer were selected, respectively. Optimum concentration of PCR reagents were 3 mM MgCl2, 150 pmol primers, 0. 2 mM dNTPs, 10 ng template DNA, and 2 U Taq DNA polymerase and the optimum PCR program consisted of an initial denaturation for 4 min at 94° C followed by 45 cycles of 1 min at 94° C, 2 min at 31° C, 2 min at 72° C, and a final extension at 72° C for 10 min. Results of optimized RAPDPCR were reproducible for S. pyogenes ATCC 19615 and all S. pyogenes isolates. Calculated discriminatory power was satisfactory (DI=1). Sixteen S. pyogenes isolates belonged to sixteen strains which were classified into 3 main clusters on a similarity level of 14%. Discussion and conclusion: A suitable and reproducible RAPD-PCR protocol was obtained for genotyping of S. pyogenes isolates using RAPD-PCR optimization. The optimized protocol in the present study can be used in subsequent experiments on RAPD-PCR profiling for epidemiological study of S. pyogenes isolates.

Cementation is one of the processes employed for recovering Copper from leach liquors especially in small scale mines. The kinetics of cementation is important because of its effect on the capital and operating costs. In this research, the effect of agitation intensity, Cu-concentration, pH, iron surface and reaction time on the cementation kinetics of copper from Cheezeh ore leach liquors has been investigated. The experimental DESIGN method was carried out by using the 2k FACTORIAL approach. Experimental results showed that agitation intensity, Cu-concentration, pH and interaction between Cu-concentration and Ph have the most significant effect on cementation kinetics. Optimum conditions were agitation intensity = 300 rpm, pH=L Cu-concentration= 7 g/l and iron surface= 31.2 cm2. The kinetic constant under these conditions was estimated as 7.66*10-3min-I.

Background and Aim: There is a close relationship between working posture and workstation DESIGN so that the postural problems appear to be largely caused by improperly DESIGNed workstation. There can be no more fundamental aspect of occupational ergonomics than the concern with the DESIGN of the workstation. There is general agreement that health, well-being and productivity of workers are strongly dependent on the success of workstation DESIGN. In ergonomic DESIGN of workstation, different factors should be taken into consideration, above all posture determinant factors. Regarding this, FACTORIAL DESIGN is a very useful methodology for identifying posture determinant factors. By this methodology, workstation variables which affect working posture can be identified. Then, optimum values of these variables are determined for working posture improvement. By this means, workstation DESIGN guidelines can be developed. In this paper, which has been prepared with the aim of introducing FACTORIAL DESIGN in ergonomic studies, an example of FACTORIAL DESIGN application in developing workstation DESIGN guidelines for weaving operation is presented.Materials and Methods: In a FACTORIAL DESIGN of 3x3, nine sets of experimental conditions were tested. The nine sets of experimental conditions consisted of different combinations of seats and weaving heights. Thirty professional weavers participated in the experiments and performed their normal weaving task in 9 experimental sessions. The effects of weaving height and seat type on postural variables were tested by Analysis of Variance (ANOVA) for Repeated Measures.Results: The results obtained in the nine settings were compared and the setting in which optimum working posture adapted was determined. Based on the results, weaving workstation guidelines were developed.Conclusion: It is believed that the recommended workstation improves working posture and results in reduced postural stress on weavers' bodies and, consequently, reduced prevalence of MSDs symptoms.

Background and Objective: There is ample evidence that prevalence of both communicable and no communicable diseases due to consumption of red meat and its processed products, e.g., sausages, is on the increase. Considering this, and concern about undesirable effects of adding preservatives to red meat products, prompted us to explore the feasibility of producing non-meat sausage without addition of preservatives.Materials and Methods: The fixed components of the sausage to be produced were isolatedsoy protein, gluten, soybean oil, ice, water, salt and spices. Using the full actorial DESIGN method, 8 formulations were developed, each one of the 3 variable components(modified corn starch, carrageen an and egg white powder) being added to the fixed componentsattwolevels. To judge the quality of the processed products, sensory evaluation was performed on taste, odor, and texture, slicing ability and overall acceptability by the hedonic (scale 1-9) test. In addition, the ability of the model was assessed by lack of fittest, correlation coefficient(R2) androot meansquare error (RMSE). Also ANOVA was performed to determine the independent effect of each one of the variables andtheir interactions (a p<0.05was used for statistical significance).Results: The independent effect of each variable (modified corn starch, carrageen an and egg white) on each response shows that the overall evaluation model (p=0.0001; lack of fit=0.1220; r=0.83, the highest correlation)is the best model for predicting the optimum formulation. Further analysis of the data showed that, in addition to the independent effect of each of the the 3 variable components, their interactions also affect overall assessment significantly.Conclusion: Based on the equation obtained for overall assessment, it can be concluded that real levels of 0.5, 3 and 3 are best for carrageen an, modified corn starch and egg white, respectively.

In order to enhancein vitro dissolution and content uniformity of poorly soluble drug glimepiride by preparing solid dispersions using modified solvent fusion method, solid dispersions of drug were prepared by modified fusion solvent method using PEG 6000 and PVP K25 (as carrier). Eight batches (F1-F8) were prepared by FACTORIAL DESIGN (23) by taking three factors i.e. the concentration of: drug (X1), PEG 6000 (X2) and PVP K25 (X3). DSC, FTIR spectroscopy, powder X-ray diffraction (XRD) and SEM studies were used to characterize solid dispersions. In vitro release was carried out using USP II dissolution apparatus. Multilinear regression analysis was applied to develop mathematical model to estimate cumulative drug release.The batch F3 was found to be best batch as it showed maximum in vitro dissolution after 30 min. Improvement in dissolution behavior of solid dispersion batches was observed due to conversion of crystalline form of drug to amorphous form as confirmed by DSC, FTIR studies and X-RD studies. SEM photographs of batch F3 showed porous nature of particle surface. Uniformity of content of different batches was found to be in range as specified by IP. Solid dispersion prepared via modified fusion solvent method was proved to be beneficial in enhancement of dissolution rate of poorly-water soluble drug using hydrophilic carriers. Retrospectively, this model can further be utilized to DESIGN solid dispersions for desired release characteristics.

Solid lipid nanoparticles of atovaquone (ATQ-SLN) were prepared by high shear homogenization method using tripalmitin, trilaurin, and Compritol 888 ATO as the lipid matrices and Phospholipon 90H, Tween 80, and poloxamer 188 as the surfactants. Optimization of the formulations was conducted using 6 sets of 24 full-FACTORIAL DESIGN based on four independent variables that were the number of homogenizing cycles, concentration of the lipid, concentration of the co-surfactant, and concentration of the main surfactant. The dependent variables were particle size and polydispersity index (PdI). The homogenizing cycles showed a negative influence on the dependent variables which reduced both the particle size and the PdI value. Moreover, a combination of certain percentages of the main surfactant and co-surfactant also showed a negative influence that reduced both the particle size and PdI value. Selected formulations from each DESIGN were further characterized for the entrapment efficiency and yield. The optimised formulation of ATQ-SLN consisted of trilaurin, Phospholipon 90H and Tween 80 with a particle size of 89.4 ± 0.2 nm and entrapment efficiency of 83.0 ± 1.7%. The in-vitro release evaluation of the formulation showed a complete and immediate release of ATQ from the SLN that could be a solution to improve the poor aqueous solubility and hence poor bioavailability of the drug.

Bone tissue scaffolds that closely mimic the mechanical and biological properties of natural bone is critical for enhancing the outcomes in treatment of bone tissue damages. This study introduces an optimisation approach to DESIGNing bone tissue engineering scaffolds using Triply Periodic Minimal Surface (TPMS) structures, evaluated through a Full FACTORIAL DESIGN methodology. Finite Element Analysis was applied to simulate the TPMS scaffolds under mechanical loading. The influence of key factors of strut thickness, unit cell configuration, and TPMS type, on the scaffold’s mechanical performance, specifically targeting Young's modulus was evaluated. By employing Full FACTORIAL DESIGN, this study generates empirical models of Young’s modulus as a function of those key factors. Primitive and Gyroid TPMS structures emerged as optimal, achieving Young's modulus values of 4912.3 MPa and 4666.7 MPa, respectively, with configurations of 0.01 mm strut thickness in a 3-unit cell construct. These results demonstrate that optimised TPMS scaffolds can meet the mechanical demands of bone tissue while providing adequate porosity for cell proliferation and nutrient transport, essential for effective bone regeneration.

The objective of this work was to develop bioadhesive topical gel of Aceclofenac with the help of response-surface approach. Experiments were performed according to a 3-level FACTORIAL DESIGN to evaluate the effects of two independent variables [amount of Poloxamer 407 (PL-407 =X1) and hydroxypropylmethyl cellulose K100 M (HPMC=X2)] on the bioadhesive character of gel, rheological property of gel (consistency index), and in-vitro drug release. The best model was selected to fit the data. Mathematical equation was generated by DESIGN Expert® software for the model which assists in determining the effect of independent variables. Response surface plots were also generated by the software for analyzing effect of the independent variables on the response. Quadratic model was found to be the best for all the responses. Both independent variable (X1 and X2) were found to have synergistic effect on bioadhesion (Y1) but the effect of HPMC was more pronounced than PL-407. Consistency index was enhanced by increasing the level of both independent variables. An antagonistic effect of both independent variables was found on cumulative percentage release of drug in 2 (Y3) and 8 h (Y4). Both independent variables approximately equally contributed the antagonistic effect on Y3 whereas antagonistic effect of HPMC was more pronounced than PL-407.The effect of formulation variables on the product characteristics can be easily predicted and precisely interpreted by using a 3-level FACTORIAL experimental DESIGN and generated quadratic mathematical equations.

A chromium electroplating bath with the ability to produce homogenous mist was used to evaluate parameters influencing hexavalent chromium (Cr+6) mist sampling methods. The results of 48 Cr+6 mist samples collected using the U.S. National Institute for Occupational Safety and Health method 7600 showed that Cr+6 concentration was higher: (1) For sampling by closed-face filter cassettes than for sampling by open-face filter cassettes (P<0.001); (2) for samples collected at 35 cm above the electroplating solution surface than for samples collected at 50 cm (P<0.001); (3) for sampling duration of 30 minutes than for sampling duration of 180 minutes (P<0.001); and, (4) for samples extracted immediately after sampling than for samples with delayed extraction (24 hours after sampling) (P<0.001). It is concluded that the accuracy of Cr+6 mist sampling in electroplating shops will be enhanced when: (1) closed-face filter cassette is used to prevent liquid splash contamination; (2) the recommended sampling height is 35 cm above the solution surface; (3) the sampling duration is short-approximately 30 minutes; and, (4) the extraction of the Cr+6 sample is performed as soon as the sampling is completed.