Asymmetric α‐Hydroxylation of a Lactone with Vinylogous Pyridone by Using a Guanidine–Urea Bifunctional Organocatalyst: Catalytic Enantioselective Synthesis of a Key Intermediate for (20S)‐Camptothecin Analogues

We have developed a catalytic asymmetric synthesis of (S)‐4‐ethyl‐6,6‐(ethylenedioxy)‐7,8‐dihydro‐4‐hydroxy‐1H‐pyrano[3,4‐f]indolizine‐3,10(4H)dione ( 5 a ), a synthetic intermediate for (20S)‐camptothecin analogues. A key step in this synthesis is an asymmetric α‐hydroxylation of a lactone with a vinylogous pyridone structure ( 8 a ) by using a guanidine–urea bifunctional organocatalyst. The present oxidation was successfully applied to the synthesis of C20‐modified derivatives of (+)‐C20‐desethylbenzylcamptothecin ( 13 ).     

sdg Interacting boson model: hexadecupole degree of freedom in nuclear structure

Thesdg interacting boson model (sdgIBM), which includes monopole (s), quadrupole (d) and hexadecupole (g) degrees of freedom, enables one to analyze hexadecupole (E4) properties of atomic nuclei. Various aspects of the model, both analytical and numerical, are reviewed emphasizing the symmetry structures involved. A large number of examples are given to provide understanding and tests, and to demonstrate the predictiveness of thesdg model. Extensions of the model to include proton-neutron degrees of freedom and fermion degrees of freedom (appropriate for odd mass nuclei) are briefly described. A comprehensive account ofsdgIBM analysis of all the existing data on hexadecupole observables (mainly in the rare-earth region) is presented, includingβ ₄ (hexadecupole deformation) systematics,B(IS4; 0 _GS ⁺ →4 _γ ⁺ ) systematics that give information about hexadecupole component in γ-vibration,E4 matrix elements involving few low-lying 4⁺ levels,E4 strength distributions and hexadecupole vibrational bands in deformed nuclei. The survey of literature for this review was concluded in December 1991.     

Instanton counting on blowup. II. K-theoretic partition function

We study Nekrasov's deformed partition function $Z(\varepsilon_1,\varepsilon_2,\vec{a};\mathfrak q,\boldsymbol\beta)$ of 5-dimensional supersymmetric Yang-Mills theory compactified on a circle. Mathematically it is the generating function of the characters of the coordinate rings of the moduli spaces of instantons on $\mathbb R^4$. We show that it satisfies a system of functional equations, called blowup equations, whose solution is unique. As applications, we prove (a) $F(\varepsilon_1,\varepsilon_2,\vec{a};\mathfrak q,\boldsymbol\beta) = \varepsilon_1\varepsilon_2 \log Z(\varepsilon_1,\varepsilon_2,\vec{a};\mathfrak q,\boldsymbol\beta)$ is regular at $\varepsilon_1 = \varepsilon_2 = 0$ (a part of Nekrasov's conjecture), and (b) the genus $1$ parts, which are first several Taylor coefficients of $F(\varepsilon_1,\varepsilon_2,\vec{a};\mathfrak q,\boldsymbol\beta)$, are written explicitly in terms of $\tau = d^2 F(0,0,\vec{a};\mathfrak q,\boldsymbol\beta)/da^2$ in rank $2$ case.     

IBA,macroscopic SU(3) and microscopic description of ground state bands in rotational nuclei

The number of bosons deduced from variational calculations of spectra and intrinsic mass quadrupole moments of heavy deformed nuclei are compared with predictions of IBA in the SU(3) limit. The differenct between the two suggest the need for including l > 2 bosons in IBA.     

Studies on the goodness of IBA group symmetries. I. Centroids,widths and partial widths for irreducible representations of IBA group symmetries

We present explicit analytic expressions for the centroids, widths and partial widths of the eigenvalue distribution over an irreducible representation corresponding to various group symmetries of the interacting boson approximation model of Arima and Iachello. As an example we present a study of the goodness of IBA group symmetries for Sm isotopes.     

Polycyclic Aromatic Hydrocarbons (PAHs) Biodegradation by Basidiomycetes Fungi, Pseudomonas Isolate, and Their Cocultures: Comparative In Vivo and In Silico Approach

The polycyclic aromatic hydrocarbons (PAHs) biodegradation potential of the five basidiomycetes' fungal monocultures and their cocultures was compared with that of a Pseudomonas isolate recovered from oil-spilled soil. As utilization of hydrocarbons by the microorganisms is associated with biosurfactant production, the level of biosurfactant production and its composition by the selected microorganisms was also investigated. The Pseudomonas isolate showed higher ability to degrade three of the five PAHs but the isolate did not produce biosurfactant higher than C. versicolor and P. ostreatus. Among the PAHs, the most effective biodegradation of PAH--pyrene (42%)--was obtained with the fungus C. versicolor. Cocultures involving the fungi and Pseudomonas could not significantly degrade the selected PAHs compounds above that degraded by the most efficient monoculture. A slight increase in pyrene degradation was observed in cocultures of C. versicolor and F. palustris (93.7% pyrene). The crude biosurfactant was biochemically characterized as a multicomponent surfactant consisting of protein and polysaccharides. The PAH biodegradation potential of the basidiomycetes fungi positively correlated with their potential to express ligninolytic enzymes such as lignin peroxidase (Lip), manganese peroxidase (Mnp), and laccase. The present study utilized in silico method such as protein-ligand docking using the FRED in Open Eye software as a tool to assess the level of ligninolytic enzymes and PAHs interactions. The in silico analysis using FRED revealed that of the five PAHs, maximum interaction occurred between pyrene and all the three ligninolytic enzymes. The results of the in silico analysis corroborated with our experimental results showing that pyrene was degraded to the maximum extent by species such as C. versicolor and P. ostreatus.     

Determination of musty odorants, 2-methylisoborneol and geosmin, in environmental water by headspace solid-phase microextraction and gas chromatography--mass spectrometry.

A simple and sensitive method for the determination of musty odorants, 2-methylisoborneol (MIB) and geosmin (GSM), in environmental water was developed by headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography-mass spectrometry. MIB and GSM were separated within 10 min using a DB-1 capillary column and detected in the selective ion monitoring mode. HS-SPME using a polydimethylsiloxane/divinylbenzene fiber provided effective sample enrichment, and was carried out by fiber exposition at 70 degrees C for 30 min. Using this method, the calibration curves of MIB and GSM were linear in the range of 0-500 pg/mL, with a correlation coefficient above 0.9977 (n=24). The detection limits (S/N=3) of MIB and GSM were 0.9 and 0.6 pg/mL, respectively. This method was successfully applied to the analysis of environmental water samples without interference peaks.     

SiC Nanostructures Toward Biomedical Applications and Its Future Challenges

The present work reviews current research activities for possible applications of silicon carbide (SiC) nanostructures. The main attention is devoted to emerging biomedical applications which can bring a boon for a healthy society. Highlights toward the widespread of SiC nanostructures in new fields of applications are reviewed and explained. This article surveys some of the recent work using SiC nanostructures in biomedical field, sensing, and energy harvesting including a review on nanostructure biocompatibility research to date.

The review article begins with an overview of the state of art of silicon carbide along with their behavior, properties, and applications of SiC in bulk, thin films, and nanoscale forms, respectively. The multidisciplinary applications of SiC nanostructures are also highlighted. Different applications elaborated are as follows: (1) biomedical/nanomedical applications, (2) nanoelectronics, (3) sensing applications, (4) energy harvesting, and (5) other emerging areas. The possibility for employing SiC nanostructures to be accomplished in upgrading the existing devices is suggested based on their properties. This article is concluded with some challenges for future applications.     

Local physical quantities for spin based on the relativistic quantum field theory in molecular systems

Local physical quantities for spin are investigated on the basis of the four‐ and two‐component relativistic quantum theory. In the quantum field theory, local physical quantities for spin such as the spin angular momentum density, spin torque density, zeta force density, and zeta potential play important roles in spin dynamics. We discuss how to calculate these local physical quantities based on the two‐component relativistic quantum theory. Some different types of relativistic numerical calculations of local physical quantities in Li atom and C₆H₆ are demonstrated and compared. Local physical quantities for each orbital are also discussed, and it is seen that a total local zeta potential is given as a result of some cancellation of large contributions from each orbital. © 2016 Wiley Periodicals, Inc.     

Ag‐CNT Architectures for Attomolar Dopamine Detection and 100‐Fold Fluorescence Enhancements with Cellphone‐Based Surface Plasmon‐Coupled Emission Platform

We report cellphone‐based detection of dopamine with attomolar sensitivity in clinical samples with the use of a surface plasmon‐coupled emission (SPCE) platform. To this end, silver‐coated carbon nanotubes were used as spacer and cavity materials on SPCE substrates to obtain up to 100‐fold fluorescence enhancements. The presence of silver on the carbon nanotubes helped to overcome fluorescence quenching arising due to π–π interactions between the carbon nanotube and rhodamine 6G. The competing adsorption of dopamine versus rhodamine 6G on graphene oxide was utilized to develop this sensing platform.