OBJECTIVES: This study compared the cyclic fatigue resistance of nickel-titanium (NiTi) files obtained in a conventional test using a simulated canal with a newly developed method that allows the application of constant fatigue load conditions. MATERIALS AND METHODS: ProFile and K3 files of #25/.06, #30/.06, and #40/.04 were selected. Two types of testing devices were built to test their fatigue performance. The first (conventional) device prescribed curvature inside a simulated canal (C-test), the second new device exerted a constant load (L-test) whilst allowing any resulting curvature. Ten new instruments of each size and brand were tested with each device. The files were rotated until fracture and the number of cycles to failure (NCF) was determined. The NCF were subjected to one-way ANOVA and Duncan's post-hoc test for each method. Spearman's rank correlation coefficient was computed to examine any association between methods. RESULTS: Spearman's rank correlation coefficient (rho = -0.905) showed a significant negative correlation between methods. Groups with significant difference after the L-test divided into 4 clusters, whilst the C-test gave just 2 clusters. From the L-test, considering the negative correlation of NCF, K3 gave a significantly lower fatigue resistance than ProFile as in the C-test. K3 #30/.06 showed a lower fatigue resistance than K3 #25/.06, which was not found by the C-test. Variation in fatigue test methodology resulted in different cyclic fatigue resistance rankings for various NiTi files. CONCLUSIONS: The new methodology standardized the load during fatigue testing, allowing determination fatigue behavior under constant load conditions.
Androsterone ; Fatigue

PVP only does not enhance the solubility of DHEA but a combination effect will manifeste once the substance is used concurrently with HPCD. In 5,59% HPCD solution, this solubility was enhanced by 115 times and in 5,59% HPCD solution adding 0,1% PVP it was enhanced by 139 times. There is a strict interaction between its components, different evidently from the physical mixed graphic
Povidone ; beta-Cyclodextrins ; Androsterone

BACKGROUND: We evaluated volumetric differences of syringe brand compatibilities, and investigated the impact of false brand settings on target-controlled infusion (TCI) and their methods of correction. METHODS: Gravimetric measurement of 10 ml bolus infusions was performed using BD Plastipak (BDP) and Terumo compatible syringes, while setting to 7 different kinds of brand compatibilities (BDP, Sherwood Monoject, BD Perfusion, Braun Perfusor, Braun Omnifix, Fresenius Injectomat, and Terumo). To investigate the performance of TCI using BDP with a false setting to Terumo (BDPTERUMO) and Terumo to BDP (TERUMOBDP), 24 TCI targeting 4.0 microg/ml of effect-site concentration (Ceff) of propofol were performed. Subsequently, another 24 TCI were evaluated for simple corrections of false settings at 30 min. We also investigated 24 TCI using active corrections (fill-up for BDPTERUMO, evacuation for TERUMOBDP) based on the pharmacokinetics of propofol. The Ceff at 30 min of TCI and time to normalize to +/- 5% of target concentration (T+/-5%target) were compared. RESULTS: The Ceff of BDPTERUMO showed negative bias and 17.2% inaccuracy, and the Ceff of TERUMOBDP showed positive bias and 19.5% inaccuracy. The Ceff at 30 min showed no difference between the methods of correction in BDPTERUMO or TERUMOBDP. The T+/-5%target in both the active corrections was significantly shorter than that of each simple corrections (P < 0.001). CONCLUSIONS: False brand setting of syringe proportionally maintained different predicted concentrations as much as the volumetric differences of syringe brand. Based on the results, it is proposed that correction methods based on pharmacokinetics could effectively normalize the differences, without giving up the wrong TCI.
Androsterone ; Bias (Epidemiology) ; Perfusion ; Propofol ; Syringes

The aim of this study was to measure the brand images of contract foodservice management companies by identifying brand image attributes and then developing a measurement scale to measure the weight of these attributes. The measurement scale was developed by following a 5-stage process that included face-to-face interviews with experts, literature review, questionnaire surveys, verification of scale validity, exploratory factor analysis, and confirmatory factor analysis. A total of 137 items measuring brand image were collected: 37 items from studies of brand image and corporate image, 55 items from studies of contract foodservice management companies and 45 items from the internet and websites of contract foodservice management companies. A survey was then conducted to assess the validity and reliability of the questionnaire items. Ultimately, the 137 items were reduced to 40 items. The calculated Cronbach's alpha for the 40 brand image items was 0.934, demonstrating good internal consistency. Based on exploratory factor analysis (EFA), employee attitude, menu content, corporate image, dining location and ambience, along with 33 subattributes, were identified as brand image attributes. Employee attitude was the most significant attribute influencing brand image. After confirmatory factor analysis (CFA) and a review process, four brand image attributes and 33 subattributes were finalized and incorporated into the scale.
Androsterone ; Contracts ; Internet ; Surveys and Questionnaires ; Reproducibility of Results

PURPOSE: Debonding of a composite resin core of the fiber post often occurs at the interface between these two materials. The aim of this study was to evaluate the effects of different surface treatment methods on bond strength between fiber posts and composite core. MATERIALS AND METHODS: Sixty-four fiber posts were picked in two groups (Hetco and Exacto). Each group was further divided into four subgroups using different surface treatments: 1) silanization; 2) sandblasting; 3) Treatment with 24% H2O2, and 4) no treatment (control group). A cylindrical plexiglass matrix was placed around the post and filled with the core resin composite. Specimens were stored in 5000 thermal cycles between 5degrees C and 55degrees C. Tensile bond strength (TBS) test and evaluation using stereomicroscope were performed on the specimen and the data were analyzed using two-way ANOVA, Post Hoc Scheffe tests and Fisher's Exact Test (alpha=.05). RESULTS: There was a significant difference between the effect of different surface treatments on TBS (P<.001) but different brands of post (P=.743) and interaction between the brand of post and surface treatment (P=.922) had no significant effect on TBS. Both silanization and sandblasting improved the bonding strength of fiber posts to composite resin core, but there were not any significant differences between these groups and control group. CONCLUSION: There was not any significant difference between two brands of fiber posts that had been used in this study. Although silanization and sandblasting can improve the TBS, there was not any significant differences between surface treatments used.
Androsterone ; Polymethyl Methacrylate ; Post and Core Technique

PURPOSE: Perceived color of ceramics changes by the spectral power distribution of ambient light. This study aimed to quantify the amount of shifts in color and color coordinates of clinically simulated seven all-ceramics due to the switch of three ambient light sources using a human vision simulating spectroradiometer. MATERIALS AND METHODS: CIE color coordinates, such as L*, a* and b*,of ceramic specimens were measured under three light sources, which simulate the CIE standard illuminant D65 (daylight), A (incandescent lamp), and F9 (fluorescent lamp). Shifts in color and color coordinate by the switch of lights were determined. Influence of the switched light (D65 to A, or D65 to F9), shade of veneer ceramics (A2 or A3), and brand of ceramics on the shifts was analyzed by a three-way ANOVA. RESULTS: Shifts in color and color coordinates were influenced by three factors (P<.05). Color shifts by the switch to A were in the range of 5.9 to 7.7 DeltaE*abunits, and those by the switch to F9 were 7.7 to 10.2; all of which were unacceptable (DeltaE*ab > 5.5). When switched to A, CIE a* increased (Deltaa*: 5.6 to 7.6), however, CIE b* increased (Deltab*: 4.9 to 7.8) when switched to F9. CONCLUSION: Clinically simulated ceramics demonstrated clinically unacceptable color shifts according to the switches in ambient lights based on spectroradiometric readings. Therefore, shade matching and compatibility evaluation should be performed considering ambient lighting conditions and should be done under most relevant lighting condition.
Androsterone ; Ceramics ; Humans ; Light ; Lighting ; Reading ; Vision, Ocular

The government is now operating a pilot project of generic prescription in the National Medical Center and planning to execute it after analyzing the results. The aims of changing Brand Name Prescription (Proprietary Names Prescription) to Generic Prescription (Nonproprietary Names Prescription) are to reduce medical expenses, to increase patient's conveniences and rights, and to strengthen pharmaceutical companies' internal competitiveness. However, we doubt whether these goals can be reached by the execution of the Generic Prescription. More important is that Korea is not well prepared with the medicine bioequivalent experiments, which can be potentially harmful to patients. If the government should carry out this plan just because the pilot project involving some relatively safe medicines does not show problems, it will confront with big damages. Namely, carrying out the Generic Prescription in an unprepared condition will not benefit but will cause a big damage to the patients.
Androsterone ; Human Rights ; Humans ; Korea ; Lifting ; Prescriptions ; Therapeutic Equivalency

BACKGROUND: Topical steroids are a widely used therapeutic agent in dermatology. However, little objective data has been collected in order to assess the awareness, knowledge and behavior of patients regarding the use of topical steroids. OBJECTIVE: The goal of this study was to investigate the current state of awareness, knowledge, and behavior of patients regarding topical steroid use. METHODS: A written questionnaire was distributed to 570 outpatients who visited the dermatologic clinics of the University Hospital. Of these, 504 were appropriate and thus were included in this study for further statistical analysis. The questionnaire consisted of 26 items concerning the overall evaluation of the awareness, and behavior of outpatients regarding their use of topical steroids. RESULTS: The results demonstrated that of 504 patients included in the analysis, 53.8% bought topical steroids with a dermatologist's prescription, whereas 33.6% obtained their topical steroids without prescription. The patient recognition rate of brand name, therapeutic effects, and side effects of topical steroids was 58%, 77% and 26%, respectively. Twenty percent of patients who have used topical steroids complained of side effects, the most common of which being pruritus (7.5% of cases). More than half of the patients said they obtained their information about topical steroids from sources other than the dermatologist. More than three quarters of patients (77%) applied topical steroids 1-2 times per day, whereas the overusers (4%) and the long-term users (16%) were applying topical steroids more than 5 times a day and longer than 16 weeks, respectively. CONCLUSION: The results indicate that topical steroids have been used without sufficient information and guidelines. Taken together, it is suggested that dermatologists should more thoroughly explain the therapeutic effects, indications, and side effects of topical steroids to their patients.
Androsterone ; Dermatology ; Humans ; Outpatients ; Prescriptions ; Pruritus ; Steroids ; Surveys and Questionnaires

BACKGROUND: Gray hair naturally develops in the process of human aging. Many people with gray hair periodically dye their hair. Hair dyeing products are widely used and they can cause adverse effects. Therefore, the user's knowledge and recognition about hair dyeing and related side effects are important. OBJECTIVE: The goal of this study was to lay the foundation for understanding, preventing and treating side effects caused by hair coloring products. METHODS: We conducted a questionnaire survey for adult males and females aged over 20 who had gray hair. A total of 500 subjects were included in this study and statistical analysis was performed. RESULTS: Large numbers of the people who had experience with hair dye (233 out of 319 people, 73.0%) did not know about the exact brand name of the hair dye product that they were using. Of 319 hair dye users, 23.8% (76 out of 319) people stated that they experienced side effects. Despite the occurrence of side effects from hair dyeing products, it seems they did not realize the seriousness of the side effects or the need for treatment. CONCLUSION: It is advisable to introduce a system that enables users to become aware of the ingredients and side effects of hair coloring products and give opportunities for users to become aware of the side effects of hair coloring through education, publicity and publication of an informational booklet.
Adult ; Aged ; Aging ; Androsterone ; Female ; Hair ; Hair Color ; Hair Dyes ; Humans ; Male ; Pamphlets ; Publications ; Surveys and Questionnaires

The aim of the present study is to compare the corrosion tendency using two kinds of NiTi files in the various environmental conditions through the visual examination and electrochemical analysis. ProTaper Universal S2, 21 mm (Dentsply Maillefer, Ballaigues, Switzerland) and Hero 642, 0.06 tapers, size 25, 21 mm (Micromega, Besancon, France) rotary instruments were tested. The instruments were randomly divided into eighteen groups (n = 5) by the immersion temperature, the type of solution, the brand of NiTi rotary instrument and the presence of mechanical loading. Each file was examined at various magnifications using Scanning Electron Microscope (JEOL, Akishima, Tokyo, Japan) equipped with energy dispersive X-ray microanalysis (EDX). EDX was used to determine the components of the endodontic file alloy in corroded and noncorroded areas. The corrosion resistance of unused and used NiTi files after repeated uses in the human teeth was evaluated electrochemically by potentiodynamic polarization test using a potentiostat (Applied Corrosion Monitoring, Cark-in-Cartmel, UK). Solution temperature and chloride ion concentration may affect on passivity of NiTi files. Under the conditions of this in vitro study, the corrosion resistance is slightly increased after clinical use.
Alloys ; Androsterone ; Collodion ; Corrosion ; Electron Probe Microanalysis ; Electrons ; Humans ; Immersion ; Tokyo ; Tooth