A phenylhydrazone-based indole receptor for sensing acetate.

A novel phenylhydrazone-based indole anion receptor is synthesized by a simple method, and the receptor binds acetate anions with good selectivity in DMSO solution, which is related to the structure of the receptor matching with the anion. The binding properties of the host are examined by UV-vis changes. The color changes of the host upon the addition of a variety of structurally different anions were also utilized as nake-eyed recognization (from orange to purple, first figure), The hydrogen bonds between recognization sites (phenylhydrazone and indole N-H) and anions were determined on the basis of (1)H NMR experiments.

[Spectral power distribution and quantum yield of Sm3+-doped bismuth tellurite glass under the excitation of violet LED].

A new method for measuring the spectral power distribution in Sm3+-doped bismuth tellurite glass with higher refractive index and lower phonon energy by using integrating sphere was introduced and designed for the first time. Fluorescence measurement system was constituted by integrating sphere of 10-inch diameter, which was connected to a DDC detector. A standard halogen lamp was used to calibrate the measurement system and the auxiliary standard halogen lamp was employed for collating inner change in integrating sphere.

Gain analysis of an optical multipass cell for spectroscopic measurements in luminous environments.

The signal improvement obtained for a spectroscopic measurement with a multipass cell can be expressed as the gain over a single pass measurement. We develop a unified analysis of amplitude gain and signal-to-noise ratio (SNR) gain for both cw and pulsed systems with application to Rayleigh/Raman spectroscopy, fluorescence, and similar techniques. Our analysis reveals that the SNR gain is dependent on the single pass efficiency, number of passes, and temporal overlap.

Flexible-Boundary Quantum-Mechanical/Molecular-Mechanical Calculations: Partial Charge Transfer between the Quantum-Mechanical and Molecular-Mechanical Subsystems.

Based on the principle of electronic chemical potential equalization, we propose a flexible-boundary scheme to account for partial charge transfers between the quantum-mechanical (QM) and molecular-mechanical (MM) subsystems in combined QM/MM calculations. The QM subsystem is viewed as an open system with a fluctuating number of electrons and is described by a statistical mixture of ensemble that consists of states of integer number of electrons. The MM subsystem serves as a reservoir that exchanges electrons with the QM subsystem.

Pathophysiological implications of transient receptor potential channels in vascular function.

Purpose Of Review: Although Ca influx plays a pivotal role in neurohormonal and myogenic control of vascular tone and slow progressive vascular remodeling, the molecular identification of those Ca sources/pathways had long been elusive. The review will introduce recent discoveries that mammalian homologues of Drosophila transient receptor potential protein expressed in various regions of the vasculature exhibit appropriate features to elucidate these pathways, with associated dysfunctions.

Recent Findings: Recent investigations have revealed that expressed as well as native vascular transient receptor potentials behave as Ca-permeable cation channels that open in response to phospholipase C-coupled vasoconstrictors, mechanical forces and/or hypertrophic stimuli, thereby regulating the vascular resistance/tone and blood pressure/flow, and proliferative/apoptotic reorganization of vascular tissues.

A novel fluorescent and colorimetric anion sensor based on thiourea derivative in competitive media.

A novel and simple fluorescent receptor bearing thiourea moiety as recognition site was described. The recognition behavior of the receptor toward different anions was investigated in DMSO/H2O (95:5 v/v) and dry DMSO through two various channels: the colorless-yellow color change and a remarkable enhancement of the fluorescence. And the enhancement of the fluorescence was attributed to an anion-induced increase of the rigidity of the host molecule.

Multicoefficient Gaussian-3 calculation of the rate constant for the OH + CH4 reaction and its 12C/13C kinetic isotope effect with emphasis on the effects of coordinate system and torsional treatment.

Rate constants and (12)C/(13)C kinetic isotope effects are calculated by direct dynamics for the OH + CH(4) --> H(2)O + CH(3) reaction. The electronic structure calculations required to generate the implicit potential energy surface were carried out by the high-level multicoefficient Gaussian-3/version-3 (MCG3) method and compared to two other multilevel methods, MC3BB and MC3MPW, and three density functional methods, M06-2X, BB1K, and MPW1K. The rate constants and (12)C/(13)C kinetic isotope effects are shown to depend strongly on the coordinate system used to calculate the frequencies as well as on the method used to account for the torsional anharmonicity of the lowest-frequency vibrational mode of the generalized transition states.

A simple and efficient colorimetric anion receptor for H(2)PO(4)(-).

A novel and neutral anion sensor bearing a urea group as binding sites and 2,4-di nitrophenylhydrazine unit as a molecular architecture and a chromophore was synthesized and the visible color changes, the UV-vis and (1)H NMR spectral responses toward anions were assessed.

Effects of the receptors bearing phenol group and copper(II) on the anion recognition and their analytical application.

Two novel artificial receptors based on diamide and bearing phenol group and copper(II) have been synthesized. Their anion-binding properties are evaluated for F(-), Cl(-), Br(-), I(-), AcO(-), H(2)PO(4)(-) and OH(-) by UV-vis and (1)H NMR titration experiments to further elucidate the impact of phenol group and copper(II) on the chemistry of anion-recognition. Results indicate that the interacted model of fluoride anion with receptor 1 is different from other anions and the (1)H NMR signals of receptor 2 occur changes after the addition of fluoride anion.

Self-Consistent Polarization of the Boundary in the Redistributed Charge and Dipole Scheme for Combined Quantum-Mechanical and Molecular-Mechanical Calculations.

The recently developed redistributed charge (RC) and redistributed charge and dipole (RCD) schemes are electrostatic-embedding schemes to treat a quantum-mechanical/molecular- mechanical (QM/MM) boundary that passes through covalent bonds. In the RC and RCD schemes, the QM subsystem is polarized by the MM subsystem, but the MM subsystem is not polarized by the QM one; this results in an unbalanced treatment of the electrostatic interactions. In the work reported here, we developed improved schemes, namely, the polarized-boundary RC scheme (PBRC) and the polarized-boundary RCD (PBRCD) scheme, by adding self-consistent mutual polarization of the boundary region of the MM subsystem to the previous schemes.

Differences in tissue-remodeling potential of aortic and pulmonary heart valve interstitial cells.

Heart valve interstitial cells (VICs) appear to have a dynamic and reversible phenotype, an attribute speculated to be necessary for valve tissue remodeling during times of development and repair. Therefore, we hypothesized that the cytoskeletal (CSK) remodeling capability of the aortic and pulmonary VICs (AVICs and PVICs, respectively), which are dominated by smooth muscle alpha-actin, would exhibit unique contractile behaviors when seeded on collagen gels. Using a porcine cell source, we observed that VIC populations did not contract the gels at early time points (2 and 4 hours) as dermal fibroblasts did, but formed a central cluster of cells prior to contraction.

Amyloid beta ion channel: 3D structure and relevance to amyloid channel paradigm.

Alzheimer's disease (AD) is a protein misfolding disease. Early hypothesis of AD pathology posits that 39-43 AA long misfolded amyloid beta (Abeta) peptide forms a fibrillar structure and induces pathophysiological response by destabilizing cellular ionic homeostasis. Loss of cell ionic homeostasis is believed to be either indirectly due to amyloid beta-induced oxidative stress or directly by its interaction with the cell membrane and/or activating pathways for ion exchange.

Biomechanical properties of native basement membranes.

Basement membranes are sheets of extracellular matrix that separate epithelia from connective tissues and outline muscle fibers and the endothelial lining of blood vessels. A major function of basement membranes is to establish and maintain stable tissue borders, exemplified by frequent vascular breaks and a disrupted pial and retinal surface in mice with mutations or deletions of basement membrane proteins. To directly measure the biomechanical properties of basement membranes, chick and mouse inner limiting membranes were examined by atomic force microscopy.

Studies on synthesis and anion recognition properties of (3'-nitrobenzo)[2,3-d]-(3''-nitrobenzo)[9,10-d]-1,4,8,11-tetraazacyclotetradecane-5,7,12,14-tetraone.

A novel artificial receptor, (3'-nitrobenzo)[2,3-d]-(3''-nitrobenzo)[9,10-d]-1,4,8,11-tetraazacyclotetradecane-5,7,12,14-tetraone, was designed and synthesized. The interactions of this receptor with different anions were determined by UV-vis and (1)H NMR titration experiments, and their affinity constants to different anions were compared with those of other similar/different systems. The results indicated that this receptor showed a high selective and recognitive ability for F(-) among F(-), Cl(-), Br(-), I(-), AcO(-), OH(-), and H(2)PO(4)(-).

Adaptive partitioning in combined quantum mechanical and molecular mechanical calculations of potential energy functions for multiscale simulations.

In many applications of multilevel/multiscale methods, an active zone must be modeled by a high-level electronic structure method, while a larger environmental zone can be safely modeled by a lower-level electronic structure method, molecular mechanics, or an analytic potential energy function. In some cases though, the active zone must be redefined as a function of simulation time. Examples include a reactive moiety diffusing through a liquid or solid, a dislocation propagating through a material, or solvent molecules in a second coordination sphere (which is environmental) exchanging with solvent molecules in an active first coordination shell.

A benzimidazole-based chromogenic anion receptor.

A benzimidazole-based anion receptor 1 has been designed and synthesized. The structure of 1 is confirmed through single crystal X-ray diffraction analysis. Anion-binding studies carried out using (1)H NMR and UV-visible revealed that this compound exhibits selective recognition toward F(-) over other halide anions.

Quantitative structure analysis of genetic diversity among spring bread wheats (Triticum aestivum L.) from different geographical regions.

Genetic diversity in spring bread wheat (T. aestivum L.) was studied in a total of 69 accessions.

Synthesis, characterization and biological activity of complexes of lanthanum(III) with 2-(1'-phenyl- 2'-carboxyl-3'-aza-n-butyl)-1,10-phenanthroline and 2-(1'-p-phenol-2'-carboxyl-3'-aza-n-butyl)-1,10-phenanthroline.

Two novel ligands 2-(1'-phenyl-2'-carboxyl-3'-aza-n-butyl)-1,10-phenanthroline (L1) and 2-(1'-p-phenol-2'-carboxyl-3'-aza-butyl)-1,10-phenanthroline (L2), and their La(III) complexes of La(III)L1, La(III)(L1)(2), La(III)L2, and La(III)(L2)(2), were synthesized and characterized by (1)H NMR, elemental analysis, IR, thermal analysis and conductance measurement. All complexes have been assayed for anticancer activity in vitro against HL-60 (human leukocytoma) cells, PC-3MIE8 (human prostate carcinoma) cells, BGC-823 (human stomach carcinoma) cells, MDA-MB-435 (human galactophore carcinoma) cells, Bel-7402 (human liver carcinoma) cells, and HeLa (human cervix carcinoma) cells. Results showed that the two complexes La(III)L1 and La(III)(L1)(2) exhibited good cytotoxic activity against different cell lines in general; and La(III)(L1)(2) is more effective than cisplatin against all six cell lines.

alpha-Tocopherol intake and plasma concentration of Hispanic and non-Hispanic white elders is associated with dietary intake pattern.

alpha-Tocopherol from foods has been associated with protection against several chronic diseases and maintenance of immune function. However, most people do not meet current recommendations for intake. We examined alpha-tocopherol intake and plasma concentration in a representative sample of Puerto Rican and Dominican older adults (n = 447) and in neighborhood-matched non-Hispanic whites (n = 155).

Multiconfiguration Molecular Mechanics Based on Combined Quantum Mechanical and Molecular Mechanical Calculations.

The multiconfiguration molecular mechanics (MCMM) method is a general algorithm for generating potential energy surfaces for chemical reactions by fitting high-level electronic structure data with the help of molecular mechanical (MM) potentials. It was previously developed as an extension of standard MM to reactive systems by inclusion of multidimensional resonance interactions between MM configurations corresponding to specific valence bonding patterns, with the resonance matrix element obtained from quantum mechanical (QM) electronic structure calculations. In particular, the resonance matrix element is obtained by multidimensional interpolation employing a finite number of geometries at which electronic-structure calculations of the energy, gradient, and Hessian are carried out.

Primary pancreatic lymphoma: report of six cases.

Aim: To heighten recognition of primary pancreatic lymphoma (PPL) in clinical practice.

Methods: A retrospective review of the clinical presentation, imaging characteristics and pathological features of PPL patients were presented, as well as their diagnosis and treatment, in combination with literature review.

Results: Histological diagnosis was made in four patients by surgery and in two patients by EUS-FNA.

Redistributed charge and dipole schemes for combined quantum mechanical and molecular mechanical calculations.

Special care is needed in carrying out combined quantum mechanical and molecular mechanical (QM/MM) calculations if the QM/MM boundary passes through a covalent bond. The present paper discusses the importance of correctly handling the MM partial point charges at the QM/MM boundary, and in particular, it contributes in two aspects: (1) Two schemes, namely, the redistributed charge (RC) scheme and the redistributed charge and dipole (RCD) scheme, are introduced to handle link atoms in QM/MM calculations. In both schemes, the point charge at the MM boundary atom that is replaced by the link atom is redistributed to the midpoint of the bonds that connect the MM boundary atom and its neighboring MM atoms.

[Calculation of optical parameters and investigation of luminescence spectra in Sm3+ doped borate glasses].

In the present paper, Sm3+ doped borate glasses (LBLB) with high effective visible fluorescence emission have been synthesized. The absorption and fluorescence spectra of this glass were measured and analyzed. The absorption spectra were fitted by J-O theory, and the intensity parameters omega = (2, 4, 6) were found to be 6.