Floral scents, specialized metabolites and stress-response activities in Heritiera fomes and Bruguiera gymnorrhiza from Sundarban mangrove ecosystem.

Floral biochemistry and stress physiology is an underexplored aspect of mangroves, which should be investigated as part of preservation and restoration efforts. A thriving true mangrove tree (Bruguiera gymnorrhiza (L.) Lamk.) and a threatened mangrove-associate species (Heritiera fomes Buch. Ham.) were studied in the Sundarban region of India for seasonal variations in floral odours, non-volatile phytochemicals, antioxidant enzyme activities, and surface water chemistry in surrounding habitat. Both species were found to exhibit significant differences in floral volatilomes, protein contents, antioxidant enzyme activities, total flavonoids, and total phenolic contents between spring and autumn blooms. The bird-pollinated flowers of B. gymnorrhiza also showed considerable seasonal differences in floral anthocyanin and proline contents, indicating vulnerability of the post-anthesis open flowers to environmental factors. Contrarily to previous findings, B. gymnorrhiza floral bouquet appeared to be enriched in various classes of volatiles - dominated by sulphurous compounds in bud stage and terpenoids in open stage. Floral anthocyanins, contributing to the striking colouration of the calyx, were found to comprise cyanidin and delphinidin derivatives. Other glycosides of cyanidin and delphinidin were detected in H. fomes flowers, contributing to visual guides to potential food rewards for pollinating insects. Floral tissue in H. fomes was found to be protected by densely overlapping layers of stellate trichomes containing sesquiterpenoids as phytoprotectants. Comparison of the two floral species suggested that H. fomes flowering is optimized to oligohaline (but not freshwater) vernal conditions; whereas B. gymnorrhiza blooms are adapted for biologically enriched (including abundant herbivores and microbial growth), mesohaline forest habitats.

A comparative study on the effect of polishing systems on the color and surface texture of different porcelain systems - feldspathic, pressable, and computer-aided design/computer-aided manufacturing.

Aim: To find and compare the qualitative and quantitative change in color and surface texture of feldspathic ceramic, pressable ceramic and ceramic used in computer-aided design/computer-aided manufacturing CAD/CAM after different surface treatments namely glazing, abrading and polishing. To compare the effectiveness of pearl finish polishing paste and Soflex polishing system used in the study. Setting and Design: In-vitro, comparative study. Materials and Methods: Disc-shaped feldsapathic, pressable, CAD/CAM ceramic specimens were fabricated. Surface roughness and color parameters Δ L*, Δa*, and Δ b* were measured before glazing, after glazing, after abrasion with 02 diamond bur and after polishing with two different polishing systems. Surface roughness was measured qualitatively using scanning electron microscopy and quantitatively using an optical profilometer. The value of color parameters was obtained using a colorimeter. Data were statistically analyzed with ANOVA. Statistical Analysis Used: SPSS software 20.0 version (IBM, New York, United states of America). Results: Unglazed feldspathic, pressable and CAD/CAM porcelain specimens showed a mean surface roughness value of 2.73 ± 0.38, 3.54 ± 1.42, and 3 ± 1.74 specimens. After glazing and polishing, the surface roughness values decreased. After abrasion, surface roughness values increased. Polishing did not alter the color along the red green axis and yellow blue axis. Conclusions: Abraded specimens of feldspathic, pressable and CAD/CAM after polishing using pearl finish polishing paste and Soflex disc became smoother than glazed specimens. When pearl finish polishing paste and Soflex discs were compared for their effectiveness the former appeared to be more superior but not to a significant level. Mechanically altering feldspathic, pressable, and porcelain used in CAD/CAM technology does not cause any change in shade.

Knowledge, awareness, attitude and practice of dental practitioners regarding Covid-19 pandemic and infection control: a cross sectional study in Kolkata metropolitan region.

BACKGROUND: Coronavirus disease 2019 (COVID-19) is a global pandemic with more than 53,973 people affected in West Bengal state of India. OBJECTIVES: The aim of present study was to assess the Knowledge, Attitudes and Practices (KAP) of dental practitioners in Kolkata city, West Bengal, India regarding COVID-2019 pandemic. MATERIALS AND METHOD: Online questionnaire was distributed among dentists across West Bengal city, using a combination of convenience and snowball sampling. The questionnaire had 17 questions: (1) Section A was 'General section' which comprised of socio-demographic and professional details of the subjects; and (2) Section B comprised of 14 questions depicting knowledge, awareness attitude and practice regarding COVID-19. The data collected was subjected to statistical analysis with level of significance at p=0.05. The descriptive statistical analysis was done to compute frequency and percentages. Intergroup comparison was determined by Chi-square statistical analysis to determine the level of significance for responses of each question. RESULTS: Around 70.4% undergraduates participated in the study. Only 4.3% showed accurate knowledge with respect to the incubation period of coronavirus. Coughing and sneezing was considered to be the most common mode of transmission. 98.9% of dentists considered fever to be the characteristic symptom of the disease. Hand washing and alcohol rubs was advocated by 99.5% of the dentist. Emergency procedures were considered necessary by 90.8% dentists. 75.1% of dentists agree that their practice has been affected by the pandemic. CONCLUSION: A constant update regarding COVID-19 should be made available to dental health care professionals through webinars, seminars, discussions and articles. Dentists should keep themselves updated and help to fight against this pandemic.