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This work surveyed the vibration behavior and stability analysis of an underwater moving flexible nanosize beam, implementing numerical and analytical methods as well as tree-based machine learning (ML) algorithms. Dynamic modeling is performed based on the nonlocal stress-strain gradient theory (NSSGT), incorporating variable environmental conditions, surface energy, and rotational inertia effects. The natural frequencies and instability threshold are computed numerically. The exact closed-form mathematical expression for the critical towing velocity of the nanosize beam is determined analytically. Also, decision tree regression and least-squares boosting tree (LSBT) regression algorithms are exploited to predict stability boundaries and the fundamental vibration frequency, and their efficiency is surveyed accordingly. Comparative studies and parametric investigations are conducted. The impressions of geometry, added mass coefficient, scale ratio parameter, surface layer characteristics, fluid mass ratio, humidity, temperature rise, and external magnetic field intensity on the nanosystem dynamics are examined and illuminated. It is detected that the results of the analytical method and ML-based approaches are consistent with those reported by the numerical technique and literature. The results asserted that the proposed ML algorithms have acceptable performance and excellent effectiveness in computational time and cost. It is comprehended that the dynamic features of submerged traveling nanobeams drastically depend on the rotational inertia effects and thickness-dependent scale effects. The stability of the immersed movable nanoscale beams is perceived to improve by increasing the scale ratio parameter and the added mass coefficient. From the perspective of the optimal design of engineering instrumentation tools, the outcomes of the current article can be applied as an inclusive benchmark. [ABSTRACT FROM AUTHOR]

Type B aortic dissection is a rare but life-threatening disease. Thoracic endovascular aortic repair (TEVAR) was widely used for Type B aortic dissection patients in the last decade due to the lower mortality and morbidity compared with open chest surgical repair (OCSR). AKI in type B aortic dissection is a well-recognized complication and indicates poor short-term and long-term outcome. The objective of this concise review was to identify the risk factors and the impact of AKI on type B aortic dissection patients. A literature search was performed using PubMed, Embase, MEDLINE, and Cochrane Library with the search terms 'type B aortic dissection' and 'acute kidney injury' (AKI), and all English-language literatures published in print or available online from inception through August 2020 were thoroughly reviewed. Studies that reported relative AKI risks and outcomes in type B aortic dissection patient were included. Major mechanisms of AKI in type B aortic dissection included renal hypoperfusion, inflammation response, and the use of contrast medium. Type B aortic dissection patients with AKI significantly had increased hospital stay duration, need of renal replacement therapy, and 30-d and 1-year mortality. AKI in type B aortic dissection is a well-recognized complication and associated with poor short-term and long-term outcome. Early identification of high-risk patients, early diagnosis of AKI, stabilization of the hemodynamic parameters, avoidance of nephrotoxic drugs, and optimization of the use of contrast agents are the major strategies for the reduction of AKI in type B aortic dissection patients. [ABSTRACT FROM AUTHOR]

This study investigates local residents' attitudes toward shale gas exploitation in China through interviews of 730 residents of Sichuan Province and explores determinants of their support or opposition. It is the first study in China to explore local residents' attitudes on this subject and we identify underlying factors contributing to such attitudes, including energy poverty, environmental awareness, and risk and benefit perceptions. The results show that the respondents are generally supportive of shale gas development. Fewer than 20% of them report opposing such development. The respondents' supportive attitudes are significantly associated with their positive benefit perceptions, trust in public entities, perspectives on impacts and risks of shale gas exploitation, and knowledge of shale gas technology, while oppositional attitudes are significantly associated with risk perception, energy poverty, and environmental awareness. [ABSTRACT FROM AUTHOR]

A one-pot synthetic strategy was developed for the synthesis of heterocyclic 1,4,2-oxazaphosphinanes via a three component Kabachnik-Fields reaction of 2-aminophenol, diphenyl H-phosphonate and carbonyl compounds. Through this newly developed method, 12 organophosphorus heterocycles and 2 related chrysin derivatives were synthesized with high yields. The target compounds were characterized by 1H, 31P and 13C NMR and MS. [ABSTRACT FROM AUTHOR]

Nanoemulgels are composed of O/W nanoemulsion and hydrogels and are considered as ideal carriers for the transdermal drug delivery because these have high affinity to load hydrophobic drugs. The stable formulation of eprinomectin (EPR) is very challenging because of it is high hydrophobic nature. In this work, we have prepared EPR loaded nanoemulgel for the treatment of endo- and ectoparasites. The surface morphology of optimized formulations was characterized by scanning electron microscopy. Additionally, skin permeability and irritation tests were conducted for in vitro safety and in vivo skin retention and pearmeation test of EPR nanoemulgel were conducted for efficacy study. Obtained results indicated that the optimized formulation had good shear-thinning behavior, bioadhesiveness properties, and are nanosized droplets with porous internal structure, which are required for topical application. Furthermore, this formulation has showed good skin permeability in comparison to suspension and has no skin irritating property. Overall, the obtained results proved that nanoemulgel is a promising carrier for transdermal drug delivery and EPR nanoemulgel is a promising formulation for the treatment of endo- and ectoparasites. [ABSTRACT FROM AUTHOR]

A series of biologically important 3/4-sulfonylquinoline derivatives was synthesized starting from easily available sodium benzenesulfinates, diethylH-phosphonate and 2-substituted quinolineN-oxides in one-pot under metal-free conditions.H-phosphonate plays a decisive role in activating the C3-H, C4-H bonds of the 2-substituted quinolineN-oxides. The isolated 3/4-sulfonylquinolines were characterized by1H,13C NMR spectroscopy and HR MS. [ABSTRACT FROM AUTHOR]

The present reaction provides a simple and convenient synthetic strategy to construct β-iodovinyl sulfones through molecular iodine and DTBP (di-tert-butyl peroxide) promoted difunctionalization of alkynes with sodium benzenesulfinates under mild and environmentally-benign conditions. A series of substituted (E)-β-iodovinyl sulfones were synthesized with excellent stereo- and regio-selectivities. [ABSTRACT FROM PUBLISHER]

Through 1,3-dipolar cycloaddition reaction, 1,4,5-trisubstituted-1,2,3-triazole and phosphate-containing chrysin derivatives were synthesized with high yields. The target compounds were characterized by1H,31P,13C NMR spectroscopy and HRMS. [ABSTRACT FROM AUTHOR]

A practical and efficient method for the synthesis of 1,2,3-triazole-amino-bisphosphonates derivatives was developed through two steps: The Michael addition reaction of propargyl amine with vinylidene bisphosphonate, and the 1,3-dipolar “click” cycloaddition assisted by ultrasound irradiation. This approach has significant advantages in terms of experimental simplicity, mild reaction condition, and can be easily scaled up. The target compounds were characterized by1H-,31P-,13C-NMR spectroscopy and high-resolution mass spectral analyses. [ABSTRACT FROM PUBLISHER]

Based on the phosphorylated reaction, an efficient general synthetic approach that provide facile, rapid and cheap access to a wide range of novel phosphoramide derivatives of paeonol has been developed. These analogues of paeonol are synthesized in high yields and elucidated by IR, HR MS, and NMR. [ABSTRACT FROM AUTHOR]

A series of new piperazine phosphoramide derivatives of 4-hydroxycoumarin were synthesized through a facile phosphorylating reaction starting from 4-hydroxycoumarin and various phosphorylating agents. The title compounds were characterized by IR, NMR, electrospray ionization-mass spectrometry, and high-resolution mass spectrometry, and their spectroscopic data were further analyzed to feature the related spectroscopic characteristics of the compounds of this class. GRAPHICAL ABSTRACT [ABSTRACT FROM AUTHOR]

Coumarin-7,8-cyclophosphoramide derivatives were conveniently prepared by a facile method. 7-Hydroxycoumarin was aminomethylated regioselectively at the 8-C position using the Mannich reaction. The newly formed 8-(N-alkylaminomethyl) coumarins were then coupled with bis-β-chloroethyl dichlorophosphamide to form coumarin-7,8-cyclophosphoramide analogs. An efficient, highly regioselective method to synthesize coumarin-7,8-cyclophosphoramide derivatives is provided, and the approach has the merits of mild reaction conditions. [ABSTRACT FROM AUTHOR]

A novel, selective, and sensitive magnetic-mimetic enzyme fluorescence immunoassay method for antigen detection has been developed by taking advantage of a magnetic separation process and the amplification feature of the hemin label. This method is based on a twice amplified fluorescence signal. The signal is first amplified due to the ultrasmall size and the high surface-to-volume ratio of the silica-coated magnetite nanoparticles, which enable the nanoparticles to carry much more antibodies. Second, the mimetic enzyme (hemin) as a labeling reagent catalyzes the reaction of p-hydroxyphenyl acetic acid and H2O2 can further amplify the fluorescence signal. This protocol was also evaluated for a sandwich-type immunoassay of human IgG, and the calibration graph for human IgG was linear over the range of 0-100 ng mL-1 with a detection limit of 9.8 ng mL-1. This method can easily separate magnetic nanoparticles from the solution, which simplified the process and played a promising role for various applications in immunoassay. [ABSTRACT FROM AUTHOR]

Several new 2-[bis(2-chloroethyl)amino)]-7-methoxyl-3-alkyl-4-methyl-1,3,2-benzoxazaphosphorin-2-oxides(3a-e) have been synthesized by cyclic condensation of bis(2-chloroethyl)amino phosphoryl dichloride and 2-(1-alkylamino) ethyl-4-methoxylphenol. The title compounds are characterized by NMR, ESI-Q-TOF, and ESI-MS. [ABSTRACT FROM AUTHOR]

Three solanesyl phosphonates were synthesized using standard Arbuzov reaction, and their structures were determined by ESI-MS, NMR, and IR. [ABSTRACT FROM AUTHOR]

Electrospray ionization ion trap mass spectrometry was used for the investigation of noncovalent complexes formed between β-cyclodextrin (CD) and protein or dipeptide in aqueous solution. After one of those noncovalent complexes has formed, it was found that addition of the other ligand compound would produce the competitive noncovalent complexes. Measurements were obtained with four proteins, such as hen egg lysozyme, cytochrome c, insulin and RNase A, and three dipeptides, respectively. The data obtained from the investigated systems show that ESI-MS is not only a reliable, sensitive, and fast technique for the analysis of the β-CD/protein and β-CD/dipeptide complexes, but also an interesting tool to observe the transformation from one complex to the other in aqueous solution. [ABSTRACT FROM AUTHOR]

7-hydroxyflavone, chrysin, 4′-chloro-7-hydroxyisoflavone and 4′-fluo-7-hydroxy-isoflavone were phosphoylated by the Atheron–Todd reaction. The expected phosphates are obtained in good yields. [ABSTRACT FROM AUTHOR]

AbstractThis work scrutinized the vibration behavior of nanoscale beam structures with rotating motion according to the nonlocal stress-strain gradient theory (NSSGT). The surface layer energy, rotary inertia factor, and thickness-dependent scale impacts are considered in the mathematical simulation. Additionally, parametric examinations are exploited to comprehend the impressions of varying environmental fields and follower and axial forces. Adopting Hamilton’s principle, the dynamic equation of nanoscale beams with rotation is achieved. The eigenvalue analysis is accomplished with the aid of the Galerkin decomposition scheme, and dynamic characteristics are recognized. Besides, machine learning (ML)-based approaches, viz., artificial neural network (ANN) and Gaussian support vector machine (GSVM) techniques, are exploited to predict the vibration frequencies. Comparison analyses with existing scientific reports in the open technical literature are conducted to guarantee the correctness of the deduced outcomes. The performance and correctness of ANN and GSVM techniques are verified by assessing the performance parameters of ML approaches. The numerical technique outcomes are consistent with those of ML-assisted models. Furthermore, the proposed ML prediction models are perceived to have excellent performance (viz., low mean square error and high determination coefficient) and superior computational time and cost-effectiveness. It is deduced that the scale-dependency in the thickness direction improves the vibration frequency. Moreover, the vibration frequencies are decreased/increased with increasing nanobeam thickness/length by considering the surface layer energy. The current research outcomes can be valuable in designing next-generation high-speed rotating nanodevices, inspiring further innovation and development in the field. [ABSTRACT FROM AUTHOR]