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101.
Muhammad Saleem Anser Ali Chang-Shik Choi Bong Joo Park Eun Ha Choi Ki Hwan Lee 《Journal of fluorescence》2014,24(4):995-1001
In recent years, fluorescent probes for the detection of environmentally and biologically important metal cations have received extensive attention for designing and development of fluorescent chemosensors. Herein, we report the photophysical results of 2-(2-fluorobenzoyl)-N-(2-methoxyphenyl) hydrazinecarbothioamide (4) functionalized as Ni (II) sensor in micromolar concentration level. Through fluorescence titration at 488 nm, we were confirmed that ligand 4 showed the remarkable emission by complexation between 4 and Ni (II) while it appeared no emission in case of the competitive ions (Cr3+, Fe2+, Co2+, Ba2+, Cu2+, Ca2+, Na+, K+, Cu+, Cs+). Furthermore, ligand 4 exhibited no toxicity with precise cell permeability toward normal living cells using L929 cell lines in bio imaging experiment investigated through confocal fluorescence microscope. The non-toxic behavior of ligand 4 (assessed by MTT assay) and its ability to track the Ni2+ in living cells suggest its possibility to use in biological system as nickel sensor. Figure
? 相似文献
102.
Bong Jae?Chung Kirk?McDermid Ashwin?VaidyaEmail author 《The European Physical Journal B - Condensed Matter and Complex Systems》2014,87(1):20
Optimality principles have long been popular in the natural sciences and enjoyed much successes in various applications. However these principles seem to be disparate, each applied in limited contexts and there are far too many of them causing some consternation among scientists and philosophers of science regarding the ad-hoc nature of the optimality arguments. In this paper, we discuss the Maximum entropy production (MaxEP) as a plausible over-arching principle to understand stable configurations in fluid mechanics and related problems. The MaxEP being based upon sound physical arguments and in the immutable laws of thermodynamics along with the fact that it has been successfully co-opted across disciplines makes it worthy of attention. We discuss various physical and metaphysical aspects of this principle and use it to analyze some model problems regarding patterns in particle sedimentation such as sedimentation of a particle in Newtonian and non-Newtonian fluids and stable deformation of a falling droplet. 相似文献
103.
Microfluidic technologies are emerging as an enabling tool for various applications in tissue engineering and cell biology. One emerging use of microfluidic systems is the generation of shape-controlled hydrogels (i.e., microfibers, microparticles, and hydrogel building blocks) for various biological applications. Furthermore, the microfluidic fabrication of cell-laden hydrogels is of great benefit for creating artificial scaffolds. In this paper, we review the current development of microfluidic-based fabrication techniques for the creation of fibers, particles, and cell-laden hydrogels. We also highlight their emerging applications in tissue engineering and regenerative medicine. 相似文献
104.
We have designed a 21-residue α-peptide that simultaneously recognizes two decadeoxyoligothymidine (dT(10)) tracts to form triplexes with a peptide-DNA strand ratio of 1:2. The synthetic peptide side chain displays 10 melamine rings, which provide a bifacial thymine-recognition interface along the length of the 21-residue peptide. Recognition is selective for thymine over other nucleobases and drives the formation of ternary peptide·[dT(10)](2) complexes as well as heterodimeric peptide·[dT(10)C(10)T(10)] hairpin structures with triplex stems. 相似文献
105.
SK Das CS Lim SY Yang JH Han BR Cho 《Chemical communications (Cambridge, England)》2012,48(67):8395-8397
We report a two-photon probe (FS1) which shows a 21-fold two-photon excited fluorescence enhancement in response to H(2)S and can selectively detect H(2)S in a rat hippocampal slice at a depth of 90-190 μm by using two-photon microscopy. 相似文献
106.
Indocyanine green (ICG) encapsulated hyaluronic acid (HA) nanogels were first studied for highly selective detection of specific cancers and lymph nodes via hyaluronidase sensitive switch-on of near infrared fluorescence as a long-lasting and stimuli-responsive imaging probe. 相似文献
107.
Eun Won Seo Ji Hee Han Cheol Ho Heo Prof. Dr. Jae Ho Shin Prof. Dr. Hwan Myung Kim Prof. Dr. Bong Rae Cho 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(39):12388-12394
Two‐photon microscopy (TPM) has become an indispensable tool in the study of biology and medicine due to the capability of this method for molecular imaging deep inside intact tissues. For the maximum utilization of TPM, a variety of two‐photon (TP) probes for specific applications are needed. In this article, we report a small‐molecule TP probe (ANO1) for nitric oxide (NO) that shows a rapid and specific NO response, a 68‐fold fluorescence enhancement in response to NO, and a maximum TP‐action cross‐section of 170 GM (GM: 10?50 cm4 photon?1) upon reaction with excess NO. This probe can be easily loaded into cells and tissues and can real‐time monitor NO in living tissues at 100–180 μm depth for longer than 1200 s through the use of TPM, with minimum interference from other biologically relevant species. 相似文献
108.
The mechanism of self-sustained oscillations in laminar cavity flows has been well characterized; however, the occurrence
of self-sustained oscillations in turbulent cavity flows has only previously been characterized by direct observation of flows.
Here, the quantitative characteristics of vortical structures in turbulent flows over an open cavity were determined, and
then statistical properties were examined for evidence of self-sustained oscillations. Specifically, instantaneous velocity
fields were measured using PIV and wall pressure fluctuations were determined from microphone data. Cavity geometries of L/D = 1 and 2, where L and D are the length and depth of the cavity, respectively, were used under conditions where the incoming boundary layer was turbulent
at Re
θ
= 830. Statistical analyses were applied based on the instantaneous velocity fields of PIV data. The spatial distributions
of vertical velocity correlations (v–v) showed alternating patterns that reflect the organized nature of the large-scale vortical structures corresponding to the
modes of N = 2 for L/D = 1 and N = 3 for L/D = 2. These values were consistent with the numbers of vortical structures obtained from a modified version of Rossiter’s equation.
Furthermore the numbers of vortical structures determined in the statistical analyses were consistently observed in instantaneous
distributions of the swirling strength (λ
ci). The incoming turbulent boundary layer can give rise to the formation of large-scale vortical structures responsible for
self-sustained oscillations. 相似文献
109.
Kingsley Christian Kemp Wanuk Choi Donghui Jo Sung Hwan Park Suk Bong Hong 《Chemical science》2022,13(35):10455
The search for new zeolite structures and compositions remains important in synthetic materials science due to the high impact on developing new chemical technologies, as well as on improving existing ones. Herein we present the synthesis and structure of PST-35, a novel medium-pore germanosilicate (Si/Ge = 2.1–6.6) zeolite, achieved by combining the excess fluoride approach and the unique structure directing ability of Ge in the presence of 1,2,3-triethylimidazolium ions as an organic structure-directing agent. PST-35 contains a zig-zag 10-ring (4.6 × 6.7 Å) channel system constructed of strictly alternating large 28-hedral ([48·58·68·82·102]) and smaller 18-hedral ([46·54·64·82·102]) cages of anomalous orthorhombic shape. The PST-35 structure is built from the connection of pst-35 layers consisting of small 8-hedral ([43·54·6]) cages, previously unobserved zeolite building layers, through single 4-rings.A medium-pore zeolite containing 2 novel orthorhombic-shaped cages was synthesized by combining the tendency of Ge to form double 4-ring units with the structure-directing ability of 1,2,3-triethylimidazolium ions under excess fluoride conditions. 相似文献
110.
Seungwan Seo Nak Ho Ahn Jeong Hwan Lee Lisa M. Knight Jaime G. Moscoso Wharton A. Sinkler Sesh Prabhakar Christopher P. Nicholas Suk Bong Hong Gregory J. Lewis 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(27):9130-9135
The charge density mismatch concept was applied to the synthesis of high‐charge‐density silicoaluminophosphate SAPO‐69 (OFF) and SAPO‐79 (ERI) and zincoaluminophosphate PST‐16 (CGS), PST‐17 (BPH), PST‐19 (SBS), and ZnAPO‐88 (MER) molecular sieves. Combined alkali‐organoammonium structure direction in these systems is thus enabled. Structure direction is treated from the perspective of stabilizing an ionic framework, the relationships between reaction charge density (OH?/H3PO4), alkali and organoammonium content, and ionicity of tetrahedral framework atoms in successful structure direction are presented. 相似文献