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101.
Bacteriochlorophyll (BChl) derivatives (with central Mg replaced by metal "M") ([M]-BChl with M = 2H, Mg, Zn, Pd, Cu) have been investigated for their photodynamic capacity and stability toward photodegradation in organic solvents and aqueous micellar solution. A protocol has been developed for screening new sensitizers. BChl and [Zn]-BChl are efficient sensitizers, but they are also quickly degraded by the reactive oxygen species (ROS) produced by autosensitization, as well as by hetero-sensitization with 17(4)-methyl-13(2)-demethoxycarbonyl-pheophorbide a (MPP). Photostable [Cu]-BChl is a poor sensitizer, whereas [Pd]-BChl and bacteriopheophytin a are not only very efficient sensitizers but are also very stable toward ROS. beta-Carotene is no efficient physical quencher of ROS in the system; rather, it acts as a photochemical quencher that competes with [M]-BChl and undergoes photooxygenation at high rates. Photolability seems to depend on the pigment oxidation potential and, in parallel, on the presence of central metals preferring coordination numbers higher than 4, whereas photodynamic capacity depends on long excited state life-times of the pigment or efficient intersystem crossing (or both). 相似文献
102.
103.
Helen?BarbasEmail author Claus?C?Hilgetag Subhash?Saha Caterina?R?Dermon Joanna?L?Suski 《BMC neuroscience》2005,6(1):32
Background
The neocortical commissures have a fundamental role in functional integration across the cerebral hemispheres. We investigated whether commissural projections in prefrontal cortices are organized according to the same or different rules as those within the same hemisphere, by quantitatively comparing density, topography, and laminar origin of contralateral and ipsilateral projections, labeled after unilateral injection of retrograde tracers in prefrontal areas. 相似文献104.
105.
We observed a strong, more than 16-fold, enhancement of Texas Red-labeled BSA fluorescence emission when deposited on silver colloid coated surfaces (SCCS). The same labeled protein deposited on silver island films (SIFs) showed an approximate 8-fold fluorescence enhancement. The lifetimes of Texas Red-BSA fluorescence are significantly shorter on silvered surfaces than on uncoated quartz substrate indicating a strong change in radiative decay rate of the dyes. We also observed a 36-fold increased brightness of overlabeled fluorescein-HSA deposited on silver colloid coated surface. Stronger enhancement observed for overlabeled Fl-HSA protein indicates that presence of silver particles partially decreased self-quenching. Our results indicate that surfaces coated with silver colloids are valuable substrates for metal-enhanced fluorescence. 相似文献
106.
Wongi Park Minyong Yang Hyewon Park Dr. Joanna M. Wolska Dr. Hyungju Ahn Prof. Dr. Tae Joo Shin Prof. Dr. Damian Pociecha Prof. Dr. Ewa Gorecka Prof. Dr. Dong Ki Yoon 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(24):7108-7113
Herein, it is reported that the polymorphism in the helical nanofilament (HNF, B4) liquid-crystalline phase depends on the fabrication methods, that is, UV-driven formation and template-assisted self-assembly in the nanoconfined geometry. As a result, uniaxially oriented HNFs with different helical structures were obtained, in which generation of the twisted-ribbon and cylindrical-ribbon polymorphs showed that even the molecular lattice has a different orientation. The detailed structures were directly observed by SEM and grazing-incidence X-ray diffraction with synchrotron radiation. The resultant polymorphs could be used in chiro-optical applications due to the capability for fine control of the helical structures. 相似文献
107.
Joanna Wilk 《Experimental Thermal and Fluid Science》2009,33(2):267-272
An experimental investigations of convective mass/heat transfer in short circular channel with small inner diameter at Re numbers ranging from 20 to 250 were performed. Mean values of convective mass transfer coefficients were measured using electrochemical technique – limiting current method. The results of dimensionless mass transfer coefficient Sh were compared with conventional theory. It was observed the increase of experimental Sh in compare with data from classical correlation relative to channels of conventional size. The heat transfer correlation was obtained on the basis of mass/heat transfer analogy. Chilton–Colburn analogy was applied. The effects were compared with the available literature experimental thermal balance results. 相似文献
108.
109.
We consider a subclass of the class of close-to-convex functions. We show the relationship between our class and the appropriate subordination. Moreover, we give the coefficient estimates and a sufficient condition for functions to belong to the class investigated. Finally, we obtain the distortion and the growth theorems. The results presented are a generalization of the results obtained by Gao and Zhou. 相似文献
110.
The aim of the paper is to point out some imprecision in Srivastava and Hui’s tests for multivariate normality. A correction for their tests is proposed. 相似文献