scholarly journals The application of Box-Behnken-Design in the optimization of HPLC separation of fluoroquinolones

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Andrzej Czyrski ◽  
Justyna Sznura
Keyword(s):  
Statistical Analysis ◽  
Retention Time ◽  
Hplc Separation ◽  
Box Behnken Design ◽  
Relative Retention ◽  
Time Symmetry ◽  
Half Height ◽  
Resolution Factor ◽  
Level Of Significance ◽  
Significant Factors

AbstractBox-Behnken Design is a useful tool for the optimization of the chromatographic analysis. The goal of this study was to select the most significant factors that influenced the following parameters of the chromatographic separation: retention time, relative retention time, symmetry of the peaks, tailing factor, a number of theoretical plates, Foley – Dorsey parameter, resolution factor, peak width at half height. The results underwent the ANOVA test to find the statistically significant variables and interactions between them. The level of significance was for p < 0.05. The polynomial equations described quantitatively the statistically significant parameters and the interactions between them. The statistical analysis indicated both the best conditions for the separation of the compounds and the variables that were most influential for peaks’ parameters. The four-factor analysis performed for LEVO and MOXI indicated that ACN, TEA and pH are the most significant factors that influence the separation. The analysis for the pair CIPRO and LEVO required six factors. The statistical analysis proved that the most significant factors are ACN, MeOH and TEA. In the separation of these two compounds on the HPLC column, the interaction ACN × MeOH was also significant.

2,2-Dialkylacetic Acids -A New Class of Naturally Occurring Lipid Constituents

1995 ◽  
Vol 50 (1-2) ◽  
pp. 123-126 ◽  
Author(s):  
Gottfried Raab ◽  
Jürgen Jacob
Keyword(s):  
Retention Time ◽  
Relative Retention Time ◽  
Methyl Esters ◽  
South American ◽  
Time Data ◽  
New Class ◽  
The Past ◽  
Relative Retention ◽  
Naturally Occurring ◽  
Acetic Acids

Abstract The uropygial gland waxes of the South American red-legged Seriema (Cariama cristata (L., 1766)) were found to be composed of unbranched alcohols and 2,2′-dialkyl-substituted acetic acids which so far have not been found in skin lipids. When used as a chemosystematic character, the occurrence of this lipid class separates the order Cariamiformes (Seriemas) from all other avian orders hitherto investigated, especially from the Gruiformes (cranes and rails) to which they have been tentatively attributed in the past. From the GC retention time data now available for a series of 2-alkyl-substituted fatty acid methyl esters relative retention time indices for other compounds may be predicted.

scholarly journals Effect of the ketoprofen on the preemptive analgesia in female cats undergoing to ovariohysterectomy

Revista CERES ◽  
2017 ◽  
Vol 64 (1) ◽  
pp. 18-24
Author(s):  
Dayvid Vianêis Farias de Lucena ◽  
Fernanda Vieira Henrique ◽  
Amara Gyane Alves de Lima ◽  
Almir Pereira de Souza ◽  
Pedro Isidro da Nóbrega Neto
Keyword(s):  
Statistical Analysis ◽  
Preemptive Analgesia ◽  
Pain Scores ◽  
Significant Difference ◽  
Reduction Of Pain ◽  
Baseline Values ◽  
Student’S T ◽  
Level Of Significance ◽  
Postoperative Administration ◽  
Student’S T Test

ABSTRACT The objective of this study was to investigate the effect of the ketoprofen on the preemptive analgesia in female cats submitted to ovariohysterectomy. Sixteen healthy cats were distributed into two groups, with eight animals each, by means of a draw, in a preemptive group (PREG), in which the animal received ketoprofen (1 mg/kg) subcutaneously two hours before the surgery; and postsurgery group (POSG), in which ketoprofen (1 mg/kg) was administered subcutaneously immediately after surgery. In both groups, ketoprofen was given 24, 48 and 72 hours after the first adminstration. Heart and respiratory frequencies and glycemia were measured in all animals during the days first ten postsurgery. Analgesia was measured by assigning scores at zero, two, four, six, 12, 24, 48, 72, 96, 120, 144, 168, 192, 216 and 240 hours after the surgical procedure. Statistical analysis was performed using two-way analysis of variance followed by Tukey's test to compare the moments and Student's t-test for comparison between groups. Pain scores were evaluated using test of U-Mann-Withney or Kruskall-Wallis, all at the 5% level of significance. Pain scores were significantly lower in PREG in M0, M6, M72, M96 and M120. No significant difference was found in the levels of glycemia in comparison to baseline values. Ketoprofen promotes postsurgery analgesia in female cats submitted to ovariohysterectomy and preemptive and postsurgery administration provides an earlier reduction of pain scores when compared to postoperative administration, only.

scholarly journals Enzyme Immunoassay for Aflatoxin B1-Lysine Adduct and Its Validation

2001 ◽  
Vol 84 (5) ◽  
pp. 1465-1474 ◽  
Author(s):  
Nayak Sujatha ◽  
Sarilla Suryakala ◽  
Beedu Sashidhar Rao
Keyword(s):  
Enzyme Immunoassay ◽  
Aflatoxin B1 ◽  
Retention Time ◽  
Simple Procedure ◽  
Molar Ratio ◽  
Rat Serum ◽  
In Vitro Synthesis ◽  
Coating Antigen ◽  
Relative Retention

Abstract A simple procedure was developed for in vitro synthesis and characterization of aflatoxin B1-lysine adduct using aflatoxin B1, N-α-acetyl lysine and m-chloroperbenzoic acid (MCPBA). At a molar ratio of 1:16 (aflatoxin B1:N-α-cetyl lysine), the recovery of adduct was 62%. Analysis of the adduct by thinlayer chromatography showed a single spot (Rf= 0). Absorption spectra of the adduct showed 2 peaks at 275 and 335 nm. Liquid chromatographic (LC) analysis of th AFB1-lysine adduct showed a relative retention time of 2.1 min. Using the same epoxidation procedure, BSA-AFB1 adduct and ovalbumin-AFB1 adduct were synthesized for production of antibodies and as coating antigen, respectively. Control rat serum, spiked with AFB1-lysine adduct and subjected to LC analysis showed a retention time of 2.1 min, which is similar to that of AFB1-lysine reference standard, synthesized. Further, enzymatically hydrolyzed, control rat serum spiked with BSA-AFB1 adduct showed 2 peaks with retention times of 2.1 and 2.7 min. Based on the LC analysis, recovery of BSA-AFB1 in terms of AFB1-lysine adducts was 67 ± 5%. The major peak (2.1 min) accounted for 72% of the adduct; the second minor peak (2.7 min) accounted for 28% of the total AFB1-lysine adducts formed. Stability studies on the AFB1-lysine adduct synthesized, indicated that it was stable for 1 month. Antibody capture assay showed an absorbance of 0.9 to 1.0 at a dilution of 1:50 000 when ovalbumin-AFB1 was used as a coating antigen. Indirect competitive ELISA showed 50% displacement (IC50) of the antibodies at a concentration of 13 ng AFB1-lysine, whereas the IC50 for AFB1 was 7 ng. The recovery of AFB1-lysine adduct spiked to control rat serum followed by enzymatic hydrolysis and immunoanalysis (indirect ELISA) was 93 ± 6%. The enzyme immunoassay was validated by a rodent model, in which the animals were exposed to aflatoxin B1 (20 μg AFB1/kg body mass/day). The level of AFB1-lysine adduct in the rat serum was 27.3 ± 4.37 μg/mg albumin.

scholarly journals Fuel and lubricant consumption in felling the young oak-hornbeam stands

2002 ◽  
pp. 59-66
Author(s):  
Vojislav Bajic ◽  
Milorad Danilovic
Keyword(s):  
Statistical Analysis ◽  
Analysis Of Variance ◽  
Unit Area ◽  
Function Form ◽  
Tree Diameter ◽  
Significant Difference ◽  
The Difference ◽  
Level Of Significance ◽  
Average Consumption

Based on the elements of statistical analysis on the dependence of fuel and lubricant consumption on tree diameter, it was assessed that with the increase of tree diameter, the fuel and lubricant consumption in the young oak and hornbeam stands decreases significantly, both in clear felling and in thinning and that the function form Y=exp(a+b x X?1) is the best description of the correlation The consumption of fuel compared to lubricant consumption is almost double, which agrees with the results of the previous studies. Average consumption of fuel and lubricant is 17.43 mL x tree?1, on the plots 20.27 mL x tree?1, average consumption of lubricant per tree on skid roads is 9.4 mL x tree?1, on the plots 11 mL x tree?1. The higher consumption of fuel and lubricant on the plots with selective thinning is the consequence of the longer time needed for the conversion per tree, compared to that in clear felling The consumption of fuel per unit area on the skid roads (clear felling) is 22.9 L x ha?1, on the plots (selective thinning) 7.6 L x ha?1. The consumption of lubricant on the skid roads is 13.3 L x ha?1, on the plots 4.29 L x ha?1. The higher consumption of fuel and lubricant per unit area on the skid roads is due to the difference in the number of trees per unit area Based on the results of the analysis of variance, it was found out that between fuel and lubricant consumption in selective thinning and in felling the trees along tractor skid roads there is no statistically significant difference at the level of significance of 95%. So, for practical purposes, the unique norms of consumption can be established for the stands similar to those in which the study was performed.

scholarly journals PENGARUH PROFESIONALISME DAN KOMITMEN ORGANISASI TERHADAP KINERJA INTERNAL AUDITOR PADA BPK PERWAKILAN DKI JAKARTA

2019 ◽  
Vol 2 (2) ◽  
pp. 390
Author(s):  
Ratna Ningsih Radjak
Keyword(s):  
Statistical Analysis ◽  
Organizational Commitment ◽  
Hypothesis Testing ◽  
Multiple Regression ◽  
Regression Coefficient ◽  
Internal Auditor ◽  
Research Results ◽  
Internal Auditors ◽  
Level Of Significance ◽  
Positive Effect

This study aims to determine the Effect of Professionalism and Organizational Commitment on Internal Auditor Performance on DKI Jakarta Representative BPK. The method used to determine the Effect of Professionalism and Organizational Commitment on Internal Auditor Performance uses multiple regression statistical analysis. Based on the research results and hypothesis testing it can be proven that partially the professionalism variable has a positive effect on the performance of the Internal Auditor. While the Organizational Commitment variable significantly influences the performance of the Internal Auditor. Simultaneously the variable Professionalism and Organizational Commitment significantly influence the performance of Internal Auditors. The ability of the variable Professionalism and Organizational Commitment to explain changes in Auditor Performance is equal to 60.8% and the rest is caused by other factors not examined. Of the three variables that most dominantly affect the performance of the Internal Auditor is Professionalism, based on the value of the regression coefficient and the t-level of significance of the Professionalism variable is higher than the Organizational Commitment variable. Thus the Auditor Professionalism really helps the Auditor to improve his performance.

scholarly journals EXPERIMENTAL DESIGN FOR SIMULTANEOUS PRODUCTION OF PHB, MESOPHILIC PROTEASES AND LIPASES

2011 ◽  
Vol 12 (2) ◽  
pp. 155-184 ◽  
Author(s):  
Amro Abd al fattah Amara
Keyword(s):  
Statistical Analysis ◽  
Experimental Design ◽  
Bacillus Pumilus ◽  
Bacillus Species ◽  
Bacillus Sp ◽  
Box Behnken Design ◽  
Simultaneous Production ◽  
The Media ◽  
Excel Solver

ABSTRACT: Bacillus species are able to produce PHB, Proteases and Lipases. Bacillus subtilius, Bacillus pumilus, Bacillus therigienesis and Bacillus sp. were used. Plackett-Burman, Box-Behnken design and the Excel solver were used to optimize the production. The statistical analysis of the results proved insignificant relationship between the media compositions and the responses. The results clearly proved a competition between the production of PHB, Proteases and Lipases. Meanwhile systematic experimental design succeeded to minimize this competition. The maximum gained PHB in this study were 16.48 g/l/48 hr. In case of Proteases and Lipases were 534, and 22.56 Units/ml/48 h respectively. The strategies used in this study are recommended for simultaneous production of PHB and proteases. For some extend lipases produced too.

LEUKEMIA AND MEDICAL RADIATION

PEDIATRICS ◽  
1959 ◽  
Vol 23 (3) ◽  
pp. 453-461
Author(s):  
Donald W. Polhemus ◽  
Richard Koch
Keyword(s):  
Statistical Analysis ◽  
Maternal Exposure ◽  
Gastrointestinal System ◽  
Medical Radiation ◽  
The Difference ◽  
Level Of Significance ◽  
Roentgen Rays

Radiation histories were compiled on 251 leukemic children and compared with an equal number of matched controls. In general, exposure to radiation was significantly more frequent among the leukemic group. Thymic irradiation was found to be associated with six times the usual incidence of leukemia, the data being highly significant (p &lt;.01). Statistical analysis of the data relative to fluoroscopic studies of the heart or gastrointestinal system, even though not highly significant, does indicate the possibility of a relationship between this type of radiation and an increased incidence of leukemia (p &lt;.05). Diagnostic roentgenograms had been performed more frequently in the leukemic group, but the level of significance was not great (p &lt;.05). Maternal exposure to roentgen rays during pregnancy had occurred somewhat more commonly in the leukemic group, but the difference was too small to be significant (p &lt;.10).

Computational Techniques in Statistical Analysis and Exploitation of CNC Machining Experimental Data

2012 ◽  
pp. 111-143 ◽  
Author(s):  
N. A. Fountas ◽  
A. A. Krimpenis ◽  
N. M. Vaxevanidis
Keyword(s):  
Statistical Analysis ◽  
Cnc Machining ◽  
Cnc Machine Tools ◽  
Computational Techniques ◽  
Sculptured Surfaces ◽  
Cnc Machine ◽  
Machining Processes ◽  
Software Modules ◽  
Level Of Significance ◽  
Cam Software

Extracting CNC machining data on- or off-line demands thorough and careful planning. Exploitation of this data can be carried out by statistical methods, in order to obtain the most influential parameters along with their respective level of significance. However, significance of machining parameters varies according to the posed Quality Characteristics at each machining phase. In actual experiments, measuring devices and assemblies are used, and data is recorded in computer archives. To shorten the production time and cost, machining processes are planned on CAM software, especially when complex part geometries, such as sculptured surfaces, are involved. Hence, planning machining experiments using CAM software modules is an efficient approach for experimentation on the actual CNC machine tools. Data extraction and statistical analysis methodologies are presented along with respective machining experimental examples.

Capillary Gas Chromatographic Separation of Various Stimulants

1985 ◽  
Vol 68 (4) ◽  
pp. 809-810
Author(s):  
Devendra Trivedi
Keyword(s):  
Retention Time ◽  
Chromatographic Separation ◽  
Relative Retention Time ◽  
Reference Standard ◽  
Relative Retention ◽  
Gas Chromatographic Separation

Abstract A capillary gas chromatographic (GC) method was developed for the separation of various stimulants of forensic and pharmaceutical interest. The data consist of retention time, relative retention time, corrected retention time, and relative corrected retention time, calculated using ephedrine as reference standard.

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