Synthesis and single crystal structures of substituted-1,3-selenazol-2-amines

This article belongs to the Special Issue Celebrating Two Centuries of Research in Selenium Chemistry: State of the Art and New ProspectivesThe synthesis and X-ray single crystal structures of a series of new 4-substituted-1,3-selenazol-2-amines is reported. The efficient preparation of 4-substituted-1,3-selenazol-2-amines was carried out by two-component cyclization of the selenoureas with equi-molar amounts of α-haloketones. The selenoureas were obtained from the reaction of Woollins’ reagent with cyanamides, followed by hydrolysis with water. All new compounds have been characterized by IR spectroscopy, multi-NMR (1H, 13C, 77Se) spectroscopy, accurate mass measurement and single crystal X-ray structure analysis.Publisher PDFPeer reviewe

Synthesis and structural study of novel selenation derivatives of N, N-Dialkylcyanamides

We are grateful to the University of St Andrews for financial support and the EPSRC National Mass Spectrometry Service Centre (Swansea) for mass spectral measurements.The reaction of 2,4-bis(phenyl)-1,3-diselenadiphosphetane-2,4-diselenide {[PhP(Se)(µ-Se)]2, Woollins’ reagent, WR } with N, N-dialkylcyanamides 1–3 in refluxing toluene solution led to the corresponding [2+3] cycloaddition products 4-dialkylamino-2,5-diphenyl-1,3,2,5-selenazadiphosphole 2,5-diselenides 4–6 in good yields, the latter were further treated with water resulting in the corresponding hydrolysis derivatives dialkyl-selenoureas 7–9 , and phosphinodiselenoates 10 and 11 . Selenourea 7 could be transferred into 1,3-selenazol-2-amines 12–15 in excellent yields by further cyclization with four different α-haloketones. All new compounds have been characterized by IR spectroscopy, multi-NMR (1H, 13C, 31P, 77Se) spectroscopy and accurate mass measurement. The single crystal X-ray structural features of nine new compounds are also discussed.PostprintPostprintPeer reviewe

Estimation of Total Body Skeletal Muscle Mass in Chinese Adults: Prediction Model by Dual-Energy X-Ray Absorptiometry

Background: There are few reports on total body skeletal muscle mass (SM) in Chinese. The objective of this study is to establish a prediction model of SM for Chinese adults. Methodology: Appendicular lean soft tissue (ALST) was measured by dual energy X-ray absorptiometry (DXA) and SM by magnetic resonance image (MRI) in 66 Chinese adults (52 men and 14 women). Images of MRI were segmented into compartments including intermuscular adipose tissue (IMAT) and IMAT-free SM. Regression was used to fit the prediction model SM = c + k × ALST. Age and gender were adjusted in the fitted model. The piece-wise linear function was performed to further explore the effect of age on SM. ‘Leave-One-Out Cross Validation’ was utilized to evaluate the prediction performance. The significance of observed differences between predicted and actual SM was tested by t test and the level of agreement was assessed by the method of Bland and Altman. Results: Men had greater ALST and IMAT-free SM than women. ALST was the primary predictor and highly correlated with IMAT-free SM (R2 = 0.94, SEE = 1.11 kg, P<0.001). Age was an additional predictor (SM prediction model with age adjusted R2 = 0.95, SEE = 1.05 kg, P<0.001). There was a piece-wise linear relationship between age and IMAT-free SM: IMAT-free SM = 1.21×ALST−0.98, (Age <45 years) and IMAT-free SM = 1.21×ALST−0.98−0.04× (Age−45), (Age ≥45years). The prediction performance of this age-adjusted model was good due to ‘Leave-One-Out Cross Validation’. No significant difference between measured and predicted IMAT-free SM was detected. Conclusion: Previous SM prediction model developed in multi-ethnic groups underestimated SM by 2.3% and 3.4% for Chinese men and women. A new prediction model by DXA has been established to predict SM in Chinese adults

SafeLight: A Reinforcement Learning Method toward Collision-free Traffic Signal Control

Traffic signal control is safety-critical for our daily life. Roughly one-quarter of road accidents in the U.S. happen at intersections due to problematic signal timing, urging the development of safety-oriented intersection control. However, existing studies on adaptive traffic signal control using reinforcement learning technologies have focused mainly on minimizing traffic delay but neglecting the potential exposure to unsafe conditions. We, for the first time, incorporate road safety standards as enforcement to ensure the safety of existing reinforcement learning methods, aiming toward operating intersections with zero collisions. We have proposed a safety-enhanced residual reinforcement learning method (SafeLight) and employed multiple optimization techniques, such as multi-objective loss function and reward shaping for better knowledge integration. Extensive experiments are conducted using both synthetic and real-world benchmark datasets. Results show that our method can significantly reduce collisions while increasing traffic mobility.Comment: Accepted by AAAI 2023, appendix included. 9 pages + 5 pages appendix, 12 figures, in Proceedings of the Thirty-Seventh AAAI Conference on Artificial Intelligence (AAAI'23), Feb 202

Single crystal X-ray structural features of aromatic compounds having a pentafluorosulfuranyl (SF5) functional group

The authors are grateful to the University of St Andrews for financial support.Nine pentafluorosulfuranyl (SF5)-containing aromatic compounds have been characterized crystallographically. The SF5 group has an umbrella geometry, and the sulfur atom in the SF5 group is in an approximately octahedral coordination environment. All S-F bond lengths [1.572(3) to 1.618(3) Å] are very similar and the C-S-Fax bond angles [178.94(14) to 180°] are very close to each other. The angle of two adjacent Feq is approximate to 90°. The intramolecular and intermolecular interactions such as Caryl-H···Feq, Caryl-H···O/N/F/Cl interactions, and π-stacking interactions play a very important role in their three-dimension packing frameworks.PostprintPostprintPeer reviewe

Evaluation of Juglans regia L., root for wound healing via antioxidant, antimicrobial and anti-inflammatory activity

304-311The burden of the management of problematic skin wounds characterized by a compromised skin barrier is growing rapidly. There is an urgent requirement for efficient mechanism-based treatments and more efficacious drug delivery systems. The present study was aimed to examine the wound healing potential of Juglans regia L. root (JR) in rats by incision and excision wound methods via the anti-inflammatory, antioxidant and antimicrobial activities. We have used tensile strength and biochemical parameters for studying the wound healing properties of JR by incision wound methodology. The anti-inflammatory effect was assessed by the measurement of paw edema in carrageenan-induced inflammation in rats. The wound contraction area, antioxidant status, and antimicrobial studies were exhausted excision wound methodology. There was a significant decrease in percent inhibition of paw edema (0.63 ± 0.03 to 0.33 ± 0.02 after 24 h) with an increase in JR concentration. Tensile strength and hydroxyproline level of different concentrations (1, 2.5, 5, and 10% w/w) of JR ointment treated groups were found significantly (P <0.001) comparable to the reference group. Moreover, JR showed significant antimicrobial and antioxidant properties, by its ability to increase antioxidant and antimicrobial levels. In conclusion, the overall results obtained in this study clarify that JR inhibits paw edema and accelerates cutaneous wound healing

Efficient synthesis of novel chalcogen-containing derivatives of DNA nucleobases

The formation of a library of chalcogen-containing DNA nucleobase derivatives is presented. Reacting easily accessible 9-(2-bromoethyl)adenine with chalcogen-containing nucleophilic reagents led to a series of novel heteroatom derivatives incorporating S, Se and Te atoms prepared in satisfactory yields. Two representative X-ray structures are reportedPostprintNon peer reviewe