Correction for 'Benzoflavone derivatives as potent antihyperuricemic agents' by Jatinder V. Singh
et al.
,
MedChemCommun
, 2019, DOI:
10.1039/c8md00512e
.
SNH Arylamination of 5-, 6-, 7-, and 8-nitroquinolines in anhydrous DMSO gave not only the arylamino derivatives of the respective nitroquinolines, but also the arylamino derivatives of ...nitrosoquinolines. In the case of 6-nitroquinoline, the first representatives of polycyclic structures on the basis of pyrido3,2-aphenazine 7-oxide were isolated.
A diastereoselective zinc-mediated propargylation of non-enolizable norbornyl alpha-diketones and an efficient AgI-catalyzed cycloisomerization of the resulting alpha-keto homopropargyl alcohols with ...terminal alkynes leading to spirocyclic dihydrofurans have been reported. The dihydrofurans obtained were subjected to hydrogenation to afford spiro tetrahydrofuran derivatives in nearly quantitative yields (98-99%). Eventually, the prepared alpha-spiro tetrahydrofuran norbornyl monoketones were utilized as precursors for acid-mediated Grob-type fragmentation reactions and converted into 1-oxaspiro4.5decan-6-one derivatives by treatment with p-toluenesulfonic acid.
•The fractional differences and sums within delta and nabla are studied summarized and related by some identities so that it becomes helpful to proceed to other types of fractional differences.•The ...definition of left and right fractional differences with discrete exponential kernels and their corresponding sums have been given and studied on the time scale hZ. (CFC and CFR h-fractional differences and their corresponding CF h-fractional sums)•The definition of left and right fractional differences with discrete MittagLeffler kernels and their corresponding sums have been given and studied on the time scale hZ. (ABC and ABR h-fractional differences and their corresponding AB h-fractional sums)•Working on hZ will guarantee better numerical solutions for complex system models depending on discrete fractional calculus and it will affect the domain of convergence for the fractional differences and sums.
The aim of this article is to recall and study fractional derivatives with singular kernels on hZ and define fractional derivatives with non-singular exponential and Mittag–Leffler kernels on hZ and study some of their properties. We shall follow the nabla time scale analysis and relate the h−nabla classical discrete fractional derivatives to the delta existing ones studied before by some authors. Some dual identities between left and right and delta and nabla, left and right h−fractional difference types will be investigated. The nabla h− discrete versions of the Mittag-Leffler functions will be recalled by means of the nabla h−fatorial functions and nabla h−Taylor polynomials. The discrete Laplace on hZ and its convolution theory are used often to proceed in our investigation. The obtained results will generalize the nabla classical discrete fractional differences and the nabla discrete fractional differences with discrete exponential and ML−kernels studied recently by Abdeljawad and Baleanu by setting h=1.
No nonlocality. No fractional derivative Tarasov, Vasily E.
Communications in nonlinear science & numerical simulation,
September 2018, 2018-09-00, 20180901, Letnik:
62
Journal Article
Recenzirano
Odprti dostop
•Principle of nonlocality for fractional derivatives is suggested.•A criterion, which allows one to identify false fractional derivatives, is proposed.•Conformable and local fractional derivatives ...are equivalent to integer derivatives.•Alternative and M-fractional derivatives are equivalent to integer derivatives.•The Caputo–Fabrizio fractional derivatives are equivalent to integer derivatives.
The paper discusses the characteristic properties of fractional derivatives of non-integer order. It is known that derivatives of integer orders are determined by properties of differentiable functions only in an infinitely small neighborhood of the considered point. Therefore differential equation, which is considered for this point and contains a finite number of integer-order derivatives, cannot describe nonlocality in space and time. This allows us to propose a principle of nonlocality for fractional derivatives. We state that if the differential equation with fractional derivative can be presented as a differential equation with a finite number of integer-order derivatives, then this fractional derivative cannot be considered as a derivative of non-integer order. This means that all results obtained for this type of fractional derivatives can be derived by using differential operators with integer orders. To illustrate the application of the nonlocality principle, we prove that the conformable fractional derivative, the M-fractional derivative, the alternative fractional derivative, the local fractional derivative and the Caputo–Fabrizio fractional derivatives with exponential kernels cannot be considered as fractional derivatives of non-integer orders.
Aberrant fetal programming in gestational diabetes mellitus seems to increase the risk of obesity, type 2 diabetes, and cardiovascular disease. The inability to accurately identify gestational ...diabetes mellitus in the first trimester of pregnancy has thwarted ascertaining whether early therapeutic interventions reduce the predisposition to these prevalent medical disorders.
A metabolomics study was conducted to determine whether advanced analytical methods could identify accurate predictors of gestational diabetes mellitus in early pregnancy.
This nested observational case-control study was composed of 92 gravidas (46 in the gestational diabetes mellitus group and 46 in the control group) in early pregnancy, who were matched by maternal age, body mass index, and gestational age at urine collection. Gestational diabetes mellitus was diagnosed according to community standards. A comprehensive metabolomics platform measured 626 endogenous metabolites in randomly collected urine. Consensus multivariate criteria or the most important by 1 method identified low–molecular weight metabolites independently associated with gestational diabetes mellitus, and a classification tree selected a subset most predictive of gestational diabetes mellitus.
Urine for both groups was collected at a mean gestational age of 12 weeks (range, 6–19 weeks’ gestation). Consensus multivariate analysis identified 11 metabolites independently linked to gestational diabetes mellitus. Classification tree analysis selected a 7-metabolite subset that predicted gestational diabetes mellitus with an accuracy of 96.7%, independent of maternal age, body mass index, and time of urine collection.
Validation of this high-accuracy model by a larger study is now needed to support future studies to determine whether therapeutic interventions in the first trimester of pregnancy for gestational diabetes mellitus reduce short- and long-term morbidity.
An orthogonal aminoacyl-tRNA synthetase/tRNA pair is a crucial prerequisite for site-specific incorporation of unnatural amino acids. Due to its high codon suppression efficiency and full ...orthogonality, the pyrrolysyl-tRNA synthetase/pyrrolysyl-tRNA pair is currently the ideal system for genetic code expansion in both eukaryotes and prokaryotes. There is a pressing need to discover or engineer other fully orthogonal translation systems. Here, through rational chimera design by transplanting the key orthogonal components from the pyrrolysine system, we create multiple chimeric tRNA synthetase/chimeric tRNA pairs, including chimera histidine, phenylalanine, and alanine systems. We further show that these engineered chimeric systems are orthogonal and highly efficient with comparable flexibility to the pyrrolysine system. Besides, the chimera phenylalanine system can incorporate a group of phenylalanine, tyrosine, and tryptophan analogues efficiently in both E. coli and mammalian cells. These aromatic amino acids analogous exhibit unique properties and characteristics, including fluorescence, post-translation modification.
This study analyzes the effect of ambiguity aversion on precautionary effort under a two period model when background risk like income risk is added to loss. Precautionary effort only affects the ...probability of loss occurrence. The sufficient conditions under which a risk averse and ambiguity averse individual makes more effort than a risk averse and ambiguity neutral one are as follows. First, the distribution of background risk changes in type of first order stochastic dominance. Second, the distribution of background risk changes in type of second order stochastic dominance and the utility function shows prudence. In both cases, AAA (absolute ambiguity aversion) should not increase. That is, AAA denotes DAAA (Decreasing Absolute Ambiguity Aversion) or CAAA (Constant Absolute Ambiguity Aversion). The effect of AAA is not observed in the existing literatures which assume a one-period model. In a one period model, the effect of AAA on precautionary effort of a long term may have ignored. Lastly, precautionary effort increases if and only if AAA is not increasing in cases when the background risk follows binary distribution or an individual is risk neutral and ambiguity averse.