Commercial Statistical Software Package Research Articles

Depth of Cure, Hardness, Roughness and Filler Dimension of Bulk-Fill Flowable, Conventional Flowable and High-Strength Universal Injectable Composites: An In Vitro Study.

(1) Objective: To evaluate and compare the depth of cure (DOC) of two bulk-fill flowable composites (Filtek Bulk Fill Flowable Restorative and Tetric EvoFlow Bulk Fill), two conventional flowable composites (Filtek Supreme XTE Flowable Restorative and G-ænial Flo X) and one high-strength universal injectable composite (G-ænial Universal Injectable). (2) Methods: specimens were placed in a stainless-steel mold with an orifice of 4 mm in diameter and 10 mm in depth and light-cured for 20 s using a light emitting diode (LED) light-curing unit (LCU) with an irradiance of 1000 mW/cm2; depth of cure was assessed using the ISO 4049 scrape technique, and the absolute length of the specimen of cured composite was measured in millimeters with a digital caliper. The same procedure was repeated with 14 samples for each material under investigation, for a total number of 70 test bodies. Material roughness and hardness results were also investigated using, respectively, a 3D laser confocal microscope (LEXT OLS 4100; Olympus) at ×5 magnification and a Vickers diamond indenter (Vickers microhardness tester, Shimadzu®, Kyoto, Japan) under 10-N load and a 30 s dwell time. SEM images at 3000 and 9000 magnification were collected in order to study the materials’ filler content. Statistical analysis were performed by a commercial statistical software package (SPSS) and data were analyzed using multiple comparison Dunnett’s test. (3) Results: The average DOC of both bulk-fill composites was more than 4 mm, as a range of 3.91 and 4.53 mm with an average value of 4.24 and 4.12 mm, while that of the conventional flowable composites was much lower, as a range of 2.47 and 2.90 mm with an average value of 2.58 and 2.84 mm; DOC of the high-strength injectable composite was greater than the one of traditional composites, but not to the level of bulk-fill materials, as a range of 2.82 and 3.01 mm with an average value of 3.02 mm. Statistical analysis revealed significant differences (p-values < 0.05) in the depth of cure between bulk fill flowable composites and other composites, while there was no difference (p-values > 0.05) between the materials of the same type. (4) Conclusions: Bulk-fill flowable composites showed significantly higher depth of cure values than both traditional flowable composites and high-strength injectable composites.

Research Dominance Definitions May Not Identify Higher Risk Limb for Anterior Cruciate Ligament Injury in NCAA D3 Student-Athletes.

Background/PurposeRecent work has identified non-significant correlations of established limb dominance to the lower extremity (LE) at greater risk for Anterior Cruciate Ligament (ACL) injury in an active, non-athletic sample. The most common LE dominance definition is preferred leg to kick a ball. Athletes develop a unilaterality pattern different from their active, non-athlete peers. Therefore, the purpose of this study was to explore the correlation between the LE used to kick a ball with and the limb identified at greater risk of ACL injury in National Collegiate Athletic Association (NCAA) Division III athletes.DesignAn Observational Descriptive study designMethodsForty-six student-athletes that were active on their NCAA Division III football, field hockey, volleyball, and soccer team rosters were recruited. Upon completing consent, participants performed two tasks (kicking a ball; unilateral land) in a counterbalanced order. Data were entered into and analyzed with a commercial statistical software package where a phi coefficient and Chi-squared analysis were performed.ResultsOf the 46 student athletes who participated (Female=32, Male=14, 19.48±1.26years, 171.75±10.47cm, 77.26±18.74kg), 25 participants kicked and landed with the same limb. Twenty participants chose kicking and landing with different limbs. The Phi Coefficient (Φ= 0.001; P= 0.97) indicated little to no relationship between the LE a participant kicked and landed with. Likewise, the Chi-square statistic revealed no statistical differences between observed and expected frequencies (χ2= 0.001; p= 0.97).Discussion/ConclusionNCAA Division III athletes display a statistical absence of preferred limb predictability utilizing the most common dominance definition (kicking a ball) as it relates to identifying LE at risk of ACL injury. The results suggest that the prevalent LE dominance definition is problematic when exploring ACL injury risk in this population.

Application of control charts for non-normally distributed data using statistical software program: A technical case study

Control charts are a valuable assessment tool in the healthcare industry. The ease of use of these trending charts is crucial to obtain timely important results with minimum time and efforts. The current case showed analysis of non-normal data to obtain control charts with useful output without using exhaustive different means of transformation and/or omitting aberrant numbers. Raw results for the quality of purified water from water treatment plant that converts municipal water to purified water were collected from two points-of-use - (ζ and Ψ). Data gathered were conductivity and total organic carbon (TOC) measurements. The statistical processing and control charts were done using commercial statistical software package. Statistical analysis of data showed that conductivity and TOC results of both points did not follow Gaussian distribution except TOC of point Ψ where it passed normality test, but they were closest to other distributions. There were several observations of outlier values from the results. Moreover, data normalization did not improve after removal of the extreme values. Data were switched to be interpreted using Laney-modified attribute control charts and compared with the original results drawn using individual-moving range (I-MR). Interestingly, both types of control charts agreed regarding control limits and some alarm points. I-MR and Laney-attribute charts could be used for non-normal data with unusual other types of distributions that may not be suitable for conventional types of control charts with the variable charts possess greater sensitivity of alarm detection over the attribute charts.

Application of statistical process control for spotting compliance to good pharmaceutical practice

For the release of pharmaceutical products into the drug market; most of the pharmaceutical companies depend on acceptance criteria - that are set internally, regulatory and/or pharmacopeially. However, statistical process control monitoring is underestimated in most quality control in cases; although it is important not only for process stability and efficiency assessment but also for compliance with all appropriate pharmaceutical practices such as good manufacturing practice and good laboratory practice, known collectively as GXP. The current work aims to investigate two tablet inspection characteristics monitored during in-process control viz. tablet average weight and hardness. Both properties were assessed during the compression phase of the tablet and before the coating stage. Data gathering was performed by the Quality Assurance Team and processed by Commercial Statistical Software packages. Screening of collected results of 31 batches of an antibacterial tablet - based on Fluoroquinolone -showed that all the tested lots met the release specifications, although the process mean has been unstable which could be strongly evident in the variable control chart. Accordingly, the two inspected processes were not in the state of control and require strong actions to correct for the non-compliance to GXP. What is not controlled cannot be predicted in the future and thus the capability analysis would be of no value except to show the process capability retrospectively only. Setting the rules for the application of Statistical Process Control (SPC) should be mandated by Regulatory Agencies.

Synergistic Effect of Polyherbal Formulations on DPPH Radical Scavenging Activity

Plant extracts contains huge number of chemical compounds that may give interaction effect which could affect the antioxidant properties especially when mixed together. Therefore, in this present study, the synergistic effect towards 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity presence in aqueous extract of herbal leaves of Strobilanthes crispus (Pecah beling), Phyllanthus niruri (Dukung anak), Orthosiphon aristatus (Misai kucing) and Stevia rebudiana has been evaluated. Synergy is the interaction of two or more extracts to produce a combined effect greater than the totality of their individual effects. There were 22 formulations consisting various proportions of the extracts designated using the commercial statistical software package which is Design Expert 6.0.4. The in-vitro antioxidant study of the extracts and their different combinations were conducted by DPPH radical scavenging activity. The results suggest that O. aristatus has higher potential of antioxidant properties. Synergistic effect was exhibited in the majority of all combinations as well as the combination of the four plant extracts. The highest synergistic effect indicated in the fifth formulation (S. crispus and P. niruri). However, the sixth formulation (S. crispus and S. rebudiana) showed the lowest synergistic effect. In conclusion, the present study justifies these polyherbal formulations have promising antioxidant properties in term of DPPH radical scavenging activity and validates their synergistic effect by having an improved activity in most of the formulations. Thus, it is sensible to mix the studied polyherbal formulations as food supplements or food ingredients in the future.

SQA: a software tool for integrated sediment quality evaluation based on the Weight-Of-Evidence procedure

A new software tool for integrative sediment quality assessment is developed. The program is based on WOE methodologies which together may be used for assessing degree of contamination in marine sediment. Statistical analysis of field-collected and lab-based data is performed by means of commercial statistical software package Statistica 6.0. The designed tool provides user-friendly interface, is extremely easy in use, greatly simplifies statistical analysis process, interprets the results in text and graphical format.

PRACTICAL APPROACH TO INTERVAL ESTIMATION FOR THE WEIBULL MEAN LIFETIME

Key Words: Censored dataDelta methodGamma functionMean lifetimeMaximum likelihood estimatorNaive estimator

The Generalised Estimating Equations: A Comparison of Procedures Available in Commercial Statistical Software Packages

The Generalised Estimating Equations: A Comparison of Procedures Available in Commercial Statistical Software Packages

The Generalised Estimating Equations: A Comparison of Procedures Available in Commercial Statistical Software Packages

The Generalised Estimating Equations (GEE) proposed by Liang and Zeger (1986) and Zeger and Liang (1986) have found considerable attention in the last decade (for an overview see e.g. Ziegler, and Blettner, 1998). Several self-made programs for solving the GEE are available. This paper presents a comparison of three GEE procedures that are already available in SAS PROC GENMOD, STATA procedure XTGEE and SUDAAN PROC MULTILOG. We show that the estimation results may be quite distinct due to different implementations. Summing up, it is pleasant that GEE is becoming established in commercial software packages. However, some aspects of the implementations should be improved. Die Generalised Estimating Equations (GEE), die zuerst von Liang und Zeger (1986) sowie Zeger und Liang (1986) vorgeschlagen wurden, fanden in den vergangenen zehn Jahren große Beachtung (für eine Übersicht s. z. B. Ziegler, Kastner und Blettner, 1998). Verschiedene selbst entwickelte Programme zum Lösen der GEE stehen zur Verfügung. In dieser Arbeit werden drei GEE Prozeduren miteinander verglichen, die in SAS PROC GENMOD, STATA Prozedur XTGEE und SUDAAN PROC MULTILOG implementiert sind. Es wird gezeigt, daß die Schätzergebnisse aufgrund unterschiedlicher Implementierungen sehr verschieden sein können. Daher ist es zwar zu begrüßen, daß die GEE inzwischen in kommerziellen Softwarepaketen zur Verfügung stehen. Doch sollten verschiedene Aspekte der derzeitigen Implementierung verbessert werden.

Cerebrovascular fiberoptic catheter oximetry in an intracranial pressure model in swine. New aspects of a clinical routine

The reliability of continuous fibreoptic oximetry in cerebral venous blood and its correlation with intracranial and cerebral perfusion pressures (pressure-volume curve) were examined in an experimental porcine study. The pressure in the infratentorial compartment of 13 domestic pigs (18-24 kg) was gradually increased by inflating a Fogarty balloon catheter placed on the surface of the right cerebellar hemisphere and below the tentorium. Single volumes of 0.4 ml saline were injected into the inflatable balloon at 1-min intervals up to a total volume of 7 ml. Intracranial pressure (ICP), arterial blood pressure, cerebral perfusion pressure (CPP), and cerebral venous saturation measured continuously by fibreoptic oximetry and intermittent blood-gas analyses (SjO2 superior sagittal sinus) were monitored during balloon inflation. All data were down-loaded onto a PC and evaluated off-line by a commercial statistical software package. Over the whole pressure-volume curve, two phases of SjO2 behaviour were registered by continuous fibreoptic oximetry (Oximetrix 3, Abbott) (Fig. 1). CPP ranges of less than 50% reduction from the initial value showed a linear correlation (rmittl. = 0.712, P < 0.01) between both parameters (CPP-SjO2). In CPP ranges below a crucial point of about 50 mmHg no such correlation was found (rmittl = 0.176, P < 0.5). In contrast, in 3 pigs a very good correlation was found between CPP and SjO2 over the whole pressure-volume curve as measured by blood-gas analyses of samples from the cerebrovenous catheter (rmittl. = 0.84, P < 0.05). We conclude that in physiological CPP ranges down to 50 mmHg, SjO2 measurement is a reliable method of detecting oxygen desaturation in cerebrovenous blood. Below that CPP value, the fibreoptic catheter showed repeated false-high oxygen saturation values. The accuracy of SjO2 measurement seems to depend on sufficient cerebral blood flow (CBF): with decreasing CBF the amount of cerebral venous outflow is diminished. We believe this is why we could not find a correlation in low CPP ranges with the oximetry catheter. This flow-dependency is a new aspect of fibreoptic cerebrovenous oximetry. The authors recommend that rising SjO2 values after desaturation events be confirmed by blood-gas analyses.

The use of LOTUS 1-2-3 in statistics

This paper describes a convenient way of performing statistical tests in biology. The recent development of powerful spreadsheet programs for microcomputers has made it possible to easily apply various statistical significance tests on biological data. Presently the following tests have been implemented in the LOTUS 1-2-3 framework: Student's t-test, chi-square test, analysis of variance (single classification random ANOVA), Student-Neumann-Kuels test, correlation analysis and analysis of linear regression (single and multilevel design). The most important advantages gained by using 1-2-3 instead of the commercial statistical software packages are the simplicity of entering data, the possibility of asking “what-if?” questions, the simple, but useful graphical presentation of data and the case of actual building of the tests.

Application of pattern-recognition techniques in wavelength selection for instrumentally read reagent strips.

Pattern recognition techniques--discriminant analysis and principal component analysis--are utilized in selecting the wavelengths for monitoring, by reflectance spectroscopy, color-generating reactions involving uric acid and cholesterol in serum. The data base we used was accumulated by a rapid-scanning reflectance spectrophotometer that measured reflectance at 16 wavelengths every 5 s after the reaction was initiated. The data were then analyzed in multidimensional space mainframe computer with commercial statistical software packages. The most appropriate wavelengths were those that yielded the largest generalized distance between analyte concentration by discriminant analysis and the largest weighting coefficient by principal component analysis. For uric acid, taking the ratio of reflectance measured at two wavelengths instead of at a single wavelength much better separates the clinically significant concentrations. For cholesterol, the initiated. The data were then analyzed in multidimensional space hemoglobin, can be clearly demonstrated y the "pattern" generated with principal component analysis. generalized distance between analyte generalized distance between analyte concentration by discriminant