喹喔啉类化合物的质谱研究

本文报道了２，６－二取代、２，３－二取代喹喔啉类化合物的电子轰击质谱。根据高分辨质谱及联动扫描质谱揭     

Extension behavior and morphology in polypropylene extended under hydrostatic pressure

The effect of hydrostatic pressure on molecular deformation of polypropylene extended under hydrostatic pressure is investigated by using internal friction measurements, wide angle X-ray diffraction, and polarizing microscopy. A homogeneously transparent straight part is obtained by extending samples in the pressure range from 78 to 128 MPa. The overall mechanical properties of a sample extended under P = 102 MPa is significantly different from that of a sample extended under P = 128 MPa. The difference is related to the magnitude of hydrostatic pressure, the extension ratio, and the extent of transparency. The observed results on the β relaxation in the extended samples is found to be related to the morphological reorganization from a coarse spherulitic to a fine spherulitic structure. The cold-drawn sample at atmospheric pressure has the γ-peak at around °50°C, while the hydrostatically extruded samples and the extended samples have no γ-peak. Consequently, the hydrostatic pressure suppresses the formation of the molecular structure relevant to the γ relaxation.     

Pseudomonas spp. convert metmyoglobin into deoxymyoglobin

Meat ‘reddening’ by bacteria was observed in chilled beef. To identify the reddening bacteria, isolates were inoculated onto beef and the changes in CIE L^*a^*b^* values monitored. As a result, two Pseudomonas spp., including Pseudomonas fragi which is commonly observed in raw meat, were selected and identified as reddening bacteria. The reddening was coincidentally occurred with the appearance of slime, and the increase in thiobarbituric acid-reactive substances (TBARS) was simultaneously suppressed. In myoglobin-containing nutrient broth, it is shown spectroscopically that P. fragi converted metmyoglobin into deoxymyoglobin. It was concluded that the meat reddening was due to the formation of deoxymyoglobin, induced by the very-low-oxygen tension brought about by Pseudomonad’s oxygen consumption: This oxygen depletion simultaneously suppressed TBARS increase.     

Note: Unshielded bilateral magnetoencephalography system using two-dimensional gradiometers

Magnetoencephalography (MEG) noninvasively measures neuronal activity with high temporal resolution. The aim of this study was to develop a new type of MEG system that can measure bilateral MEG waveforms without a magnetically shielded room, which is an obstacle to reducing both the cost and size of an MEG system. An unshielded bilateral MEG system was developed using four two-dimensional (2D) gradiometers and two symmetric cryostats. The 2D gradiometer, which is based on a low-T(c) superconducting quantum interference device and wire-wound pickup coil detects a magnetic-field gradient in two orthogonal directions, or ?/?x(?(2)B(z)/?z(2)), and reduces environmental magnetic-field noise by more than 50 dB. The cryostats can be symmetrically positioned in three directions: vertical, horizontal, and rotational. This makes it possible to detect bilateral neuronal activity in the cerebral cortex simultaneously. Bilateral auditory-evoked fields (AEF) of 18 elderly subjects were measured in an unshielded hospital environment using the MEG system. As a result, both the ipsilateral and the contralateral AEF component N100m, which is the magnetic counterpart of electric N100 in electroencephalography and appears about 100 ms after the onset of an auditory stimulus, were successfully detected for all the subjects. Moreover, the ipsilateral P50m and the contralateral P50m were also detected for 12 (67%) and 16 (89%) subjects, respectively. Experimental results demonstrate that the unshielded bilateral MEG system can detect MEG waveforms, which are associated with brain dysfunction such as epilepsy, Alzheimer's disease, and Down syndrome.     

Syntheses,characterizations, and redox behaviors of new self-assembled metal complexes with bridging ligands incorporating chalcogen sites

Three new complexes, [Zn(dbsf)₂(dmf)₂] · 5.5dmf (dbsf = 4,4′-sulfonyldibenzoate) (1β), [Cu(tdsa)(phen)₂] · 1.5EtOH (tdsa = 5,5′-thiodisalicylate, phen = 1,10-phenanthroline) (2), and [Cu(sdp)(phen) · Cu(Hsdp)(phen)(CH₃COO)] · 3EtOH (sdp = 4,4′-sulfonyldiphenolate) (3) were prepared and structurally characterized. Complex 1β shows a one-dimensional coordination framework constructed from bridges between Zn(II) centers with two ligands. Complex 2 is a monomeric complex, which assembles by π–π interactions. Complex 3 shows a unique two-dimensional coordination framework that is constructed from two Cu(II) centers, sdp, and Hsdp. The redox properties of these three complexes were characterized by solid-state cyclic voltammetry. Complexes 1β and 3 show irreversible reduction waves because of the reduction of their sulfone sites. Complex 2 shows an irreversible oxidation wave because of oxidation of the sulfide site.     

Novel polyion complex with interpenetrating polymer network of poly(acrylic acid) and partially protected poly(vinylamine) using N-vinylacetamide and N-vinylformamide

Poly(vinylamine), the simplest polycation with primary amines, was applied to interpenetrating polymer networks (IPN) with poly(acrylic acid). N-Vinylformamide (NVF) was employed for amino-protected monomers to control electrostatic balance. pH-responsivities of IPNs varied, depending on the hydrolysis conditions and acrylic acid (AAc) concentration of the second network. Poly(N-vinylacetamide)-co-poly(N-vinylformamide) (4/6, mol/mol) was employed for the first network, subsequently hydrolyzed with 50% amide groups, and the second network was polymerized with 0.25 mol L⁻¹ AAc, extremely shrunken hydrogels with polyion complex were formed at pH 7, showing that the controlled amount of highly active primary amines are available in IPN.     

Capability of Utilizing CYP3A5 Polymorphisms to Predict Therapeutic Dosage of Tacrolimus at Early Stage Post-Renal Transplantation

While CYP3A5 polymorphisms are used to predict the initial dosage of tacrolimus therapy, the predictive capability of genetic information for dosing at early stage post-renal transplantation is unknown. We investigated the influence of polymorphisms over time. An initial oral dose of modified-release once-daily tacrolimus formulation (0.20 mg/kg) was administered to 50 Japanese renal transplant patients every 24 h. Stepwise multiple linear regression analysis for tacrolimus dosing was performed each week to determine the effect of patient clinical characteristics. The dose-adjusted trough concentration was approximately 70% higher for patients with the CYP3A5*3/*3 than patients with the CYP3A5*1 allele before the second pre-transplantation tacrolimus dose (0.97 (0.78–1.17) vs. 0.59 (0.45–0.87) ng/mL/mg; p < 0.001). The contribution of genetic factors (CYP3A5*1 or *3) for tacrolimus dosing showed increased variation from Day 14 to Day 28 after transplantation: 7.2%, 18.4% and 19.5% on Days 14, 21 and 28, respectively. The influence of CYP3A5 polymorphisms on the tacrolimus maintenance dosage became evident after Day 14 post-transplantation, although the tacrolimus dosage was determined based only on patient body weight for the first three days after surgery. Tacrolimus dosage starting with the initial administration should be individualized using the CYP3A5 genotype information.     

Fabrication of Flexible and Transparent Conductive Nanosheets by the UV‐Irradiation of Gold Nanoparticle Monolayers

Conductive films that are highly transparent and flexible are extremely attractive for emerging optoelectronic applications. Currently, indium‐doped tin oxide films are the most widely used transparent conductive films and much research effort is devoted to developing alternative transparent conductive materials to overcome their drawbacks. In this work, a novel and facile approach for fabricating transparent conductive Au nanosheets from Au nanoparticles (AuNPs) is proposed. Irradiating an AuNP monolayer at the air–water interface with UV light results in a nanosheet with ≈3.5 nm thickness and ≈80% transparency in the UV–visible region. Further, the so‐fabricated nanosheets are highly flexible and can maintain their electrical conductivity even when they are bent to a radius of curvature of 0.6 mm. Fourier‐transform infrared and X‐ray photoelectron spectroscopy characterizations reveal that the transformation of the monolayer of AuNPs into the nanosheet is induced by the photodecomposition and/or photodetachment of the dodecanethiol ligands capping the AuNPs. Further, the UV‐irradiation of a hybrid monolayer consisting of AuNPs and silica particles affords the patterning of Au nanosheets with periodic hole arrays.     

Development of Endothelial Cell Networks in 3D Tissues by Combination of Melt Electrospinning Writing with Cell‐Accumulation Technology

A remaining challenge in tissue engineering approaches is the in vitro vascularization of engineered constructs or tissues. Current approaches in engineered vascularized constructs are often limited in the control of initial vascular network geometry, which is crucial to ensure full functionality of these constructs with regard to cell survival, metabolic activity, and potential differentiation ability. Herein, the combination of 3D‐printed poly‐ε‐caprolactone scaffolds via melt electrospinning writing with the cell‐accumulation technique to enable the formation and control of capillary‐like network structures is reported. The cell‐accumulation technique is already proven itself to be a powerful tool in obtaining thick (50 µm) tissues and its main advantage is the rapid production of tissues and its ease of performance. However, the applied combination yields tissue thicknesses that are doubled, which is of outstanding importance for an improved handling of the scaffolds and the generation of clinically relevant sample volumes. Moreover, a correlation of increasing vascular endothelial growth factor secretion to hypoxic conditions with increasing pore sizes and an assessment of the formation of neovascular like structures are included.