Complete and unambiguous assignments of 1H and 13C chemical shifts of new arylamino derivatives of ortho-naphthofuranquinones

Six new nor-beta-lapachones have been synthesized from reaction of 3-bromo-nor-beta-lapachone with arylamines. These derivatives have potent anticancer properties against several cell lines. Here, we report complete unambiguous assignments of (1)H and (13)C chemical shifts of the new compounds. The assignments were made using a combination of one- and two-dimensional NMR techniques ((1)H, (13)C, (1)H-(1)H COSY, (1)H-(13)C HSQC, and (1)H-(13)C HMBC).     

Heart rate variability analysis by chaotic global techniques in children with attention deficit hyperactivity disorder

Attention deficit hyperactivity disorder (ADHD) is characterized by decreased attention span, impulsiveness, and hyperactivity. Autonomic nervous system imbalance was previously described in this population. We aim to compare the autonomic function of children with ADHD and controls by analyzing heart rate variability (HRV). Children with ADHD (22 boys, mean age 9.964 years) and 28 controls (15 boys, mean age 9.857 years) rested in supine position with spontaneous breathing for 20 min. Heart rate was recorded beat by beat. HRV analysis was performed by use of chaotic global techniques. ADHD promoted an increase in the chaotic forward parameter. The algorithm which applied all three chaotic global parameters was only the second optimum statistically measured by Kruskal–Wallis (P < 0.0001) and low standard deviations. It was also highly influential by principal component analysis with almost all variation covered by the first two components. The third algorithm which lacked the (high spectral Detrended Fluctuation Analysis) parameter performed best statistically. However, we chose the algorithm which applied all three chaotic globals due to previous studies mentioned in the text—forward and inverse problems. Comparison of the autonomic function by analyzing HRV with chaotic global techniques suggests an increase in chaotic activity in children with ADHD in relation to the control group. © 2015 Wiley Periodicals, Inc. Complexity 21: 412–419, 2016     

The quadrupole moments of Cd and Zn isotopes - an apology

In 2010 we presented an update of the nuclear quadrupole moments (Q) for the Cd and Zn isotopes, based essentially on straightforward density functional (DF) calculations (H. Haas and J.G. Correia, Hyperfine Interact 198, 133–137 (2010)). It has been apparent for some years that the standard DF procedure obviously fails, however, to reproduce the known electric-field gradient (EFG) for various systems, typical cases being Cu₂O, As and Sb, and the solid halogens. Recently a cure for this deficiency has been found in the hybrid DF technique. This method is now applied to solid Cd and Zn, and the resultant quadrupole moments are about 15 % smaller than in our earlier report. Also nuclear systematics, using the recently revised values of Q for the long-lived 11/2 isomers in¹¹¹Cd to¹²⁹Cd, together with earlier PAD data for^107,109Cd, leads to the same conclusion. In addition, EFG calculations for the cadmium dimethyl molecule further support the new values: Q(¹¹¹Cd, 5/2⁺) = .683(20) b, Q(⁶⁷Zn, gs) = .132(5) b. This implies, that the value for the atomic EFG in the \(^{3}\textit {P}_{1}\) state of Zn must be revised, as it has been for Cd.     

Stability of ground-states for a system of <Emphasis Type="Italic">M</Emphasis> coupled semilinear Schrödinger equations

We focus on the study of the stability properties of ground-states for the system of M coupled semilinear Schrödinger equations with power-type nonlinearities and couplings. Our results are generalizations of the theory for the single equation and the technique used is a simplification of the original one. Depending on the power of the nonlinearity, we may observe stability, instability and weak instability. We also obtain results for three distinct classes of bound-states, which is a special feature of the \({M \geqslant 2}\) case.     

Stereoselective synthesis of the 6,6-spiroketal core of CP-61,405 (routiennocin)

A convergent and efficient synthesis of the 6,6-spiroketal core of the ionophore antibiotic CP-61,405 (routiennocin) is described. The synthesis required 10 steps from N-propionyl oxazolidinone (S)-8 and produced the desired spiroketal in 36% overall yield.     

Study by liquid secondary ion and electrospray mass spectrometry of synthesized and formed-in-source metallocorroles

Liquid secondary ion and electrospray mass spectrometry were used to study the complexation in-source of 5,10,15-tris(pentafluorophenyl)corrole with several divalent transition-metal ions. The metallocorrole ions formed in-source were identified by comparing their product ion mass spectra with the spectra of the same ions formed from metallocorroles obtained from classical procedures. Positive metallocorrole ion formation is accompanied by oxidation of the metal centre. Mechanisms were proposed for the oxidation processes, and data from negative-ion spectra reinforced these mechanisms.     

QCD2 from supergravity and mass gaps in QCD

As a test of the conjectured QCD/supergravity duality, we consider mass gaps in the supergravity construction of QCD₂. We find a mass gap in the dual field theory both when using non-rotating and rotating black D2-branes as backgrounds in the supergravity construction of QCD₂. So, since pure QCD₂ does not have a mass gap, the dual field theory of the supergravity construction of QCD₂ cannot be pure QCD₂. Considering the mass scales in the dual field theory of the supergravity construction of QCD₂, we find that this is explainable both in the case of the non-rotating background and of the rotating background. In particular, the mass gap in the case of the rotating background can be explained using results of the large angular momentum limit of euclidean rotating branes, obtained recently by Cvetic and Gubser. We furthermore remark on the possible implications for the mass gaps in the supergravity constructions of QCD₃ and QCD₄.     

A Convenient Synthesis of Diketopyrrolopyrrole Dyes

Diketopyrrolo[3,4-c]pyrroles (DPP) are high-performance organic optoelectronic materials. They have applications in solar cells, fluorescent probes, bioimaging, photodynamic/photothermal therapy, and in many other areas. This article reports a convenient two-step synthesis of various DPP dyes from Pigment Red 254, an inexpensive commercial pigment. The synthesis includes a Suzuki–Miyaura cross-coupling reaction of a bis(4-chlorophenyl)DPP derivative with aryl and hetaryl boronic acids under mild reaction conditions. The new dyes show large Stokes shifts and high fluorescence quantum yields, important features for their potential use in technical and biological applications.     

Synthesis of new aza-bicyclic 2-isoxazolines by 1,3-dipolar cycloaddition of endocyclic enecarbamates and enamides with nitrile oxides

Novel aza-bicyclic 2-isoxazolines, 4,5-dihydroisoxazole[5,4-b]pyrrolidines, and 4,5-dihydroisoxazole[5,4-b]piperidines were synthesized in a highly regioselective manner through a 1,3-dipolar cycloaddition reaction of 5- and 6-membered endocyclic enecarbamates and enamides with several nitrile oxides in good to excellent yields. Hydrogenolysis of 5- and 6-membered Cbz-cycloadducts led to secondary amines, which presented distinctive stabilities. 2-Isoxazoline bisamides were obtained in good yields through a N-benzoylation, followed by ammonolysis of the secondary amine, or directly from ammonolysis of the cycloadducts.