Biofunctional Constituents from Michelia compressa var. lanyuensis with Anti-Melanogenic Properties.

Seven compounds were extracted and purified from the roots of Michelia compressa var. lanyuensis. These compounds are liriodenine, (-)-N-acetylanonaine, pressalanine A, p-dihydroxybenzaldehyde, 3,4-dihydroxybenzoic acid, (-)-bornesitol and ß-sitostenone. These compounds were screened for anti-proliferation and anti-tyrosinase activities in B16F10 cells. Liriodenine, pressalanine A, (-)-bornesitol and ß-sitostenone displayed cytotoxicity at high concentration (100 µM), but liriodenine (5 µM), (-)-N-acetylanonaine (10 µM), and ß-sitostenone (5 µM) inhibit tyrosinase activity and reduce the melanin content in B16F10 cells without cytotoxicity, suggesting that liriodenine and ß-sitostenone could be safe and potentially used in cosmetic skin whitening.

Phase-preserved optical elevator.

The unique superiority of transformation optics devices designed from coordinate transformation is their capability of recovering both ray trajectory and optical path length in light manipulation. However, very few experiments have been done so far to verify this dual-recovery property from viewpoints of both ray trajectory and optical path length simultaneously. The experimental difficulties arise from the fact that most previous optical transformation optics devices only work at the nano-scale; the lack of intercomparison between data from both optical path length and ray trajectory measurement in these experiments obscured the fact that the ray path was subject to a subwavelength lateral shift that was otherwise not easily perceivable and, instead, was pointed out theoretically [B. Zhang et al. Phys. Rev. Lett. 104, 233903, 2010]. Here, we use a simple macroscopic transformation optics device of phase-preserved optical elevator, which is a typical birefringent optical phenomenon that can virtually lift an optical image by a macroscopic distance, to demonstrate decisively the unique optical path length preservation property of transformation optics. The recovery of ray trajectory is first determined with no lateral shift in the reflected ray. The phase preservation is then verified with incoherent white-light interferometry without ambiguity and phase unwrapping.

Combining multiple classifications of chemical structures using consensus clustering.

Consensus clustering involves combining multiple clusterings of the same set of objects to achieve a single clustering that will, hopefully, provide a better picture of the groupings that are present in a dataset. This Letter reports the use of consensus clustering methods on sets of chemical compounds represented by 2D fingerprints. Experiments with DUD, IDAlert, MDDR and MUV data suggests that consensus methods are unlikely to result in significant improvements in clustering effectiveness as compared to the use of a single clustering method.

Association of COVID-19 vaccination with herpes zoster: a systematic review and meta-analysis.

BACKGROUND: Following COVID-19 vaccination, several herpes zoster cases have been reported, making it critical to explore the association between herpes zoster and COVID-19 vaccination. This is especially true in the context of increasing the number of participants enrolled to receive COVID-19 vaccination. RESEARCH DESIGN AND METHODS: Three databases, including the Cochrane Library, PubMed, and EMBASE, were searched for relevant studies before 25 December 2021 according to preliminarily determined inclusion and exclusion criteria without any language limitations. Four cohort studies were included in this systematic review and meta-analysis. RESULTS: Compared with the placebo group, there was no evidence that the COVID-19 vaccination group was associated with increased incidence of herpes zoster (Risk ratio [RR]: 1.06; 95% confidence interval [CI]: 0.91 to 1.24). There is no evidence that the COVID-19 vaccination from Moderna is associated with the incidence of herpes zoster compared with vaccination from Pfizer (RR: 0.20; 95% CI: 0.01 to 2.99). CONCLUSIONS: To date, there is no evidence of an association between covid-19 vaccination and herpes zoster.

Biphotonic-induced reorientation inversion in azo-dye-doped liquid crystal films.

The reorientation inversion of liquid crystal molecules in azo-dye-doped liquid crystal (ADDLC) films irradiated by biphotonic (green and red light) lasers is studied using the self-phase-modulation method. The results show that the induced change of refractive index (∆n) in an ADDLC cell illuminated with a fixed intensity of green light increases with the red-light intensity. Notably, the value of ∆n is initially negative, and becomes positive when the intensity of the red laser is increasing. It is due to the fact that an extra positive torque is exerted on the LCs, which is produced by cis-isomers upon absorbing red light to compensate the negative torque induced by the excitation of the green light.

Prey envenomation does not improve digestive performance in Taiwanese pit vipers (Trimeresurus gracilis and T. stejnegeri stejnegeri).

It has been a common belief that snake venom may help in the digestion of its prey, although direct examples and supporting evidence have not been sufficient. To address this, the present study examined whether preinjecting natural amounts of pit viper venom into experimental mice may accelerate their digestion by the snakes or gain energy benefit as compared to the control without the envenomation. Live adults of two Asian pit viper species Trimeresurus gracilis and T. stejnegeri stejnegeri, which inhabit the cold and warm environment respectively, were the subjects studied herein. A natural dose of 1.2 mg of each of the pit viper venom in phosphate-buffered saline (PBS) was injected into the mouse (about 10% of the snake mass) before it was being fed to the same species of vipers, while the pit vipers in control group were given mouse injected with sterile PBS. The snakes were kept at 14 degrees C or 24 degrees C, and parameters of gut passage time, costs of digestion, and/or digestive efficiency were measured. The results did not support the hypotheses that envenomation facilitates prey digestion. The venom in fact caused longer first defecation time and lower assimilation energy at 14 degrees C. Besides, the time to reach the oxygen consumption peak, and the first defecation time of T. s. stejnegeri were longer than that of T. gracilis.

On the trail of preventing meningococcal disease: a survey of students planning to travel to the United States.

BACKGROUND: College freshmen living in dormitories are at increased risk for meningococcal disease. Many students become a high-risk population when they travel to the United States. This study surveyed the knowledge, attitudes toward, and behavior surrounding the disease among Taiwanese college students planning to study in the United States, and to identify factors that may affect willingness to accept meningococcal vaccination. METHODS: A cross-sectional survey of college students going to study in the United States was conducted in a medical center-based travel medicine clinic. Background information, attitudes, general knowledge, preventive or postexposure management, and individual preventive practices were collected through a structured questionnaire. RESULTS: A total of 358 students were included in the final analysis. More than 90% of participants believed that preventing meningococcal disease was important. However, fewer than 50% of students accurately answered six of nine questions exploring knowledge of the disease, and only 17.3% of students knew the correct management strategy after close contact with patients. Logistic regression analysis showed that students who understood the mode of transmission (odds ratio: 3.21, 95% CI = 1.117-9.229), medication management (1.88, 1.045-3.38), and epidemiology (2.735, 1.478-5.061) tended to be vaccinated. CONCLUSIONS: Despite an overall positive attitude toward meningococcal vaccination, there was poor knowledge about meningococcal disease. Promoting education on the mode of transmission, epidemiology, and pharmacological management of the disease could increase vaccination rates. Both the governments and travel medicine specialists should work together on developing an education program for this high-risk group other than just requiring vaccination.

Effect of data standardization on chemical clustering and similarity searching.

Standardization is used to ensure that the variables in a similarity calculation make an equal contribution to the computed similarity value. This paper compares the use of seven different methods that have been suggested previously for the standardization of integer-valued or real-valued data, comparing the results with unstandardized data. Sets of structures from the MDL Drug Data Report and IDAlert databases and represented by Pipeline Pilot physicochemical parameters, molecular holograms and Molconn-Z parameters are clustered using the k-means and Ward's clustering methods. The resulting classifications are evaluated in terms of the degree of clustering of active compounds selected from eleven different biological activity classes, with these classes also being used in similarity searches. It is shown that there is no consistent pattern when the various standardization methods are ranked in order of decreasing effectiveness and that there is no obvious performance benefit (when compared to unstandardized data) that is likely to be obtained from the use of any particular standardization method.