AIM: To analyze the efficacy of ultraviolet (UV) light initiating corneal cross-linking (CXL). METHODS: The time-dependent absorption of UV light due to the depletion of the initiator (riboflavin) was calculated. The ...AIM: To analyze the efficacy of ultraviolet (UV) light initiating corneal cross-linking (CXL). METHODS: The time-dependent absorption of UV light due to the depletion of the initiator (riboflavin) was calculated. The effective dose of CXL with corneal surface covered by a thin layer of riboflavin was derived analytically. The cross linking time was calculated by the depletion level of the riboflavin concentration. A comprehensive method was used to derive analytic formulas. RESULTS: The effective dose of CXL was reduced by a factor (R) which was proportional to the thickness (d) and concentrations (C-0) of the riboflavin surface layer. Our calculations showed that the conventional dose of 5.4 J/cm(2) had a reduced effective dose of 4.3 and 3.45 J/cm(2), for d was 100 and 200 pm, respectively, and C-0=0.1%. The surface cross linking time was calculated to be T*=10.75s, for a depletion level of 0.135 and UV initial intensity of 30 mW/cm(2). The volume T* was exponentially increasing and proportional to exp (bdC(0)), with b being the steady state absorption coefficient. CONCLUSION: The effective dose of CXL is reduced by a factor proportional to the thickness and concentrations of the riboflavin surface layer. The wasted dose should be avoided by washing out the extra riboflavin surface layer prior to the UV light exposure.展开更多
Dear Editor,Plant viruses cause great economic losses to tobacco production(Dai et al.,2012).Many types of viruses have been reported to infect tobacco plants,including Tobacco mosaic virus(TMV)(Chen et al.,2014),Cucu...Dear Editor,Plant viruses cause great economic losses to tobacco production(Dai et al.,2012).Many types of viruses have been reported to infect tobacco plants,including Tobacco mosaic virus(TMV)(Chen et al.,2014),Cucumber mosaic virus(CMV)(Dai et al.,2012),Tobacco展开更多
Background: Tranexamic acid and vitamin C derivatives are important reagent used in cosmetic skin-whitening products. Recently, self-perceptions regarding improvement in facial skin status have been increasingly recog...Background: Tranexamic acid and vitamin C derivatives are important reagent used in cosmetic skin-whitening products. Recently, self-perceptions regarding improvement in facial skin status have been increasingly recognized as an important outcome of whitening cosmetic products intervention. Aims: The purpose of the study was to determine the receptiveness of objective and self-perceived facial skin status using whitening cosmetic products. Methods: A total of 40 volunteers were photographed using the Visia<sup>?</sup> machine and completed questionnaires at pre- and post-operation (8 weeks after receiving whitening cosmetic products). Visia<sup>?</sup> digital image analysis and questionnaires were used for assessment of facial skin status. The receptiveness of objective and self-perceived measures was assessed by paired t test and Effect Size (ES). Results: There were progresses with regard to the surface spot (ES = 0.22), wrinkles (ES = 0.24), texture (ES = 0.31) and pores (ES = 0.21) after using cosmetic products with tranexamic acid. For self-perceived measures, there were significant progresses in pigmented spots (ES = 0.75), rough complexion (ES = 0.76), red complexion (ES = 0.41), wrinkle (ES = 0.58) and obvious pores (ES = 0.75). Conclusions: This study suggests that the whitening cosmetic products are associated with improvement of objective and self-perceived facial skin status. The results could be provided as available information for cosmetic investigation.展开更多
基金Supported by an internal grant from New Vision Inc.Talent-Xiamen(XM-200)Program(Xiamen Science&Technology Bureau,China)
文摘AIM: To analyze the efficacy of ultraviolet (UV) light initiating corneal cross-linking (CXL). METHODS: The time-dependent absorption of UV light due to the depletion of the initiator (riboflavin) was calculated. The effective dose of CXL with corneal surface covered by a thin layer of riboflavin was derived analytically. The cross linking time was calculated by the depletion level of the riboflavin concentration. A comprehensive method was used to derive analytic formulas. RESULTS: The effective dose of CXL was reduced by a factor (R) which was proportional to the thickness (d) and concentrations (C-0) of the riboflavin surface layer. Our calculations showed that the conventional dose of 5.4 J/cm(2) had a reduced effective dose of 4.3 and 3.45 J/cm(2), for d was 100 and 200 pm, respectively, and C-0=0.1%. The surface cross linking time was calculated to be T*=10.75s, for a depletion level of 0.135 and UV initial intensity of 30 mW/cm(2). The volume T* was exponentially increasing and proportional to exp (bdC(0)), with b being the steady state absorption coefficient. CONCLUSION: The effective dose of CXL is reduced by a factor proportional to the thickness and concentrations of the riboflavin surface layer. The wasted dose should be avoided by washing out the extra riboflavin surface layer prior to the UV light exposure.
基金supported by the 111 Project of the Education Ministry of China (No. B07049)the National High-tech R&D Program of China (No. 2012AA101504)
文摘Dear Editor,Plant viruses cause great economic losses to tobacco production(Dai et al.,2012).Many types of viruses have been reported to infect tobacco plants,including Tobacco mosaic virus(TMV)(Chen et al.,2014),Cucumber mosaic virus(CMV)(Dai et al.,2012),Tobacco
文摘Background: Tranexamic acid and vitamin C derivatives are important reagent used in cosmetic skin-whitening products. Recently, self-perceptions regarding improvement in facial skin status have been increasingly recognized as an important outcome of whitening cosmetic products intervention. Aims: The purpose of the study was to determine the receptiveness of objective and self-perceived facial skin status using whitening cosmetic products. Methods: A total of 40 volunteers were photographed using the Visia<sup>?</sup> machine and completed questionnaires at pre- and post-operation (8 weeks after receiving whitening cosmetic products). Visia<sup>?</sup> digital image analysis and questionnaires were used for assessment of facial skin status. The receptiveness of objective and self-perceived measures was assessed by paired t test and Effect Size (ES). Results: There were progresses with regard to the surface spot (ES = 0.22), wrinkles (ES = 0.24), texture (ES = 0.31) and pores (ES = 0.21) after using cosmetic products with tranexamic acid. For self-perceived measures, there were significant progresses in pigmented spots (ES = 0.75), rough complexion (ES = 0.76), red complexion (ES = 0.41), wrinkle (ES = 0.58) and obvious pores (ES = 0.75). Conclusions: This study suggests that the whitening cosmetic products are associated with improvement of objective and self-perceived facial skin status. The results could be provided as available information for cosmetic investigation.
