RESULTS: Two potent hydrocarbon-degraders (ADL15 and ADL36) were identified via partial 16S rRNA gene sequence analysis, and revealed to be closely related to the genus Pseudomonas and Rhodococcus sp., respectively. Factors affecting diesel degradation such as temperature, hydrocarbon concentration, pH and salt tolerance were studied. Although strain ADL36 was able to withstand a higher concentration of diesel than strain ADL15, both strains showed similar optimal condition for the cell's growth at pH 7.0 and 1.0% (w/v) NaCl at the conventional 'one-factor-at-a-time' level. Both strains were observed to be psychrotrophs with optimal temperatures of 20 °C. Qualitative and quantitative analysis were performed with a gas chromatograph equipped with a flame ionisation detector to measure the reduction of n-alkane components in diesel. In the pre-screening medium, strain ADL36 showed 83.75% of n-dodecane mineralisation while the reduction of n-dodecane by strain ADL15 was merely at 22.39%. The optimised condition for n-dodecane mineralisation predicted through response surface methodology enhanced the reduction of n-dodecane to 99.89 and 38.32% for strain ADL36 and strain ADL15, respectively.
CONCLUSIONS: Strain ADL36 proves to be a better candidate for bioaugmentation operations on sites contaminated with aliphatic hydrocarbons especially in the Antarctic and other cold regions. The results obtained throughout strongly supports the use of RSM for medium optimisation.
PURPOSE: The purpose of this study was to determine esthetic perceptions of the Malaysian population regarding the width of buccal corridor spaces and their effect on smile esthetics in individuals with short, normal, and long faces.
MATERIAL AND METHODS: The image of a smiling individual with a mesofacial face was modified to create 2 different facial types (brachyfacial and dolicofacial). Each face form was further modified into 5 different buccal corridors (2%, 10%, 15%, 22%, and 28%). The images were submitted to 3 different ethnic groups of evaluators (Chinese, Malay, Indian; 100 each), ranging between 17 and 21 years of age. A visual analog scale (50 mm in length) was used for assessment. The scores given to each image were compared with the Kruskal-Wallis test, and pairwise comparison was performed using the Mann-Whitney U test (α=.05).
RESULTS: All 3 groups of evaluators could distinguish gradations of dark spaces in the buccal corridor at 2%, 10%, and 28%. Statistically significant differences were observed among 3 groups of evaluators in esthetic perception when pairwise comparisons were performed. A 15% buccal corridor was found to score esthetically equally within 3 face types by all 3 groups of evaluators. The Indian population was more critical in evaluation than the Chinese or Malay populations. In a pairwise comparison, more significant differences were found between long and short faces and the normal face; the normal face was compared with long and short faces separately.
CONCLUSIONS: The width of the buccal corridor space influences smile attractiveness in different facial types. A medium buccal corridor (15%) is the esthetic characteristic preferred by all groups of evaluators in short, normal, and long face types.
PURPOSE: The purpose of this observational study was to measure the prevalence of the presence of the anterior loop and to estimate sex and ethnicity-related variations in anterior loop length in the Malaysian population.
MATERIAL AND METHODS: A total of 100 cone beam computed tomography (CBCT) Digital Imaging and Communications in Medicine (DICOM) files were selected from a pool of 810 ongoing or completed patients in 3 different ethnic groups: Malay (33), Indian (33), and Chinese (34). The DICOM data were imported into commercial software. The IAN was traced with software along with the anterior loop and part of the incisive nerve. The vertical length of the nerve was estimated from the canal to the opening of the mental foramen from the cross-sectional view and translated to the panoramic view. Measurement was made from this point to the most anterior point of the anterior loop by following the trajectory of the nerve and was repeated on the opposite side. A 2-way mixed analysis of variance (ANOVA) test was carried out to evaluate the sex- and ethnicity-related variations (α=.05).
RESULTS: The anterior loop was present in 94% of the 100 participants. Overall anterior loop length (AnLL) ranged between 0.73 and 7.99 mm with a mean length of 3.69 ±1.75 mm on the left side and 3.85 ±1.73 mm on the right side. Among all participants, no statistically significant differences were found between the left and right sides of the mandible (P=.379). Overall, no significant main effect of ethnicity (P=.869) or sex (P=.576) was found on AnLL measurements. Also, with multiple comparisons, no significant effect was found between each pair of ethnic groups. Men in all 3 ethnic groups had greater AnLL than women.
CONCLUSIONS: The anterior loop was present in 94% of the 100 participants among the 3 major ethnic groups of Malaysia. Overall AnLL ranged between 0.73 and 7.99 mm and mean lengths of 3.69 ±1.75 mm on the left side and 3.85 ±1.73 mm on the right side, with no significant ethnicity- or sex-related variations.