scholarly journals The Design Strategy for an Aggregation- and Crystallization-Induced Emission-Active Molecule Based on the Introduction of Skeletal Distortion by Boron Complexation with a Tridentate Ligand

Crystals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 615 ◽  
Author(s):  
Shunsuke Ohtani ◽  
Masayuki Gon ◽  
Kazuo Tanaka ◽  
Yoshiki Chujo
Keyword(s):  
Molecular Motion ◽  
Large Degree ◽  
Design Strategy ◽  
Optical Data ◽  
Tridentate Ligand ◽  
Positive Role ◽  
Distorted Structure ◽  
New Strategy ◽  
Calculation Results ◽  
Boron Complexes

We describe here a new design strategy for obtaining boron complexes with aggregation- and crystallization-induced emission (AIE and CIE, respectively) properties based on the introduction of skeletal distortion. According to our recent results, despite the fact that an almost planar structure and robust conjugation were obtained, the boron azomethine complex provided a slight emission in solution and an enhanced emission in aggregation and crystal. Quantum calculation results propose that unexpected emission annihilation in solution could be caused through intramolecular bending in the excited state. Herein, to realize this unique molecular motion and obtain AIE and CIE molecules, the phenyl quinoline-based boron complexes BPhQ and BPhQm with distorted and planar structures were designed and synthesized, respectively. BPhQm showed emission in solution and aggregation-caused quenching (ACQ, BPhQm: ΦF,sol. = 0.21, ΦF,agg. = 0.072, ΦF,cryst. = 0.051), while BPhQ exhibited a typical AIE and CIE (BPhQ: ΦF,sol. = 0.008, ΦF,agg. = 0.014, ΦF,cryst. = 0.017). The optical data suggest that a large degree of molecular motion should occur in BPhQ after photo-excitation because of the intrinsic skeletal distortion. Furthermore, single-crystal X-ray diffraction data indicate that the distorted π-conjugated system plays a positive role in presenting solid-state emission by inhibiting consecutive π–π interactions. We demonstrate in this paper that the introduction of the distorted structure by boron complexation should be a new strategy for realizing AIE and CIE properties.

Visualization and Manipulation of Molecular Motion in Solid State through Photo-Induced Clusteroluminescence

2019 ◽  
Author(s):  
Haoke Zhang ◽  
Lili Du ◽  
Lin Wang ◽  
Junkai Liu ◽  
Qing Wan ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Excited State ◽  
Solid State ◽  
Light Source ◽  
Molecular Motion ◽  
Molecular Machine ◽  
Conjugated Molecules ◽  
Time Resolved ◽  
Packing Structure ◽  
New Strategy

<p>Building molecular machine has long been a dream of scientists as it is expected to revolutionize many aspects of technology and medicine. Implementing the solid-state molecular motion is the prerequisite for a practical molecular machine. However, few works on solid-state molecular motion have been reported and it is almost impossible to “see” the motion even if it happens. Here the light-driven molecular motion in solid state is discovered in two non-conjugated molecules <i>s</i>-DPE and <i>s</i>-DPE-TM, resulting in the formation of excited-state though-space complex (ESTSC). Meanwhile, the newly formed ESTSC generates an abnormal visible emission which is termed as clusteroluminescence. Notably, the original packing structure can recover from ESTSC when the light source is removed. These processes have been confirmed by time-resolved spectroscopy and quantum mechanics calculation. This work provides a new strategy to manipulate and “see” solid-state molecular motion and gains new insights into the mechanistic picture of clusteroluminescence.<br></p>

scholarly journals Self-assembly induced luminescence of Eu3+-complexes and application in bioimaging

2021 ◽  
Author(s):  
Ping-Ru Su ◽  
Tao Wang ◽  
Pan-Pan Zhou ◽  
Xiao-Xi Yang ◽  
Xiao-Xia Feng ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Rare Earth ◽  
Luminescence Intensity ◽  
Self Assembly ◽  
Room Temperature ◽  
Molecular Motion ◽  
Proof Of Concept ◽  
Room Temperature Phosphorescence ◽  
New Strategy ◽  
Size Controlled

Abstract Design and engineering of highly efficient emitting materials with assembly-induced luminescence, such as room temperature phosphorescence (RTP) and aggregation-induced emission (AIE), have stimulated extensive efforts. Here, we propose a new strategy to obtain size-controlled Eu3+-complex nanoparticles (Eu-NPs) with self-assembly induced luminescence (SAIL) characteristics without encapsulation or hybridization. Compared with previous RTP or AIE materials, the SAIL phenomena of increased luminescence intensity and lifetime in aqueous solution for the proposed Eu-NPs are due to the combined effect of self-assembly in confining the molecular motion and shielding the water quenching. As a proof of concept, we also show that this system can be further applied in bioimaging, temperature measurement and HClO sensing. The SAIL activity of the rare-earth (RE) system proposed here offers a further step forward on the roadmap for the development of RE light conversion systems and their integration in bioimaging and therapy applications.

scholarly journals The SARS CoV-2 spike domain, RGD and integrin binding effect-relationship for vaccine design strategy

2021 ◽  
Vol 5 (1) ◽  
pp. 027-041
Author(s):  
M Luisetto ◽  
G Tarro ◽  
Edbey Khaled ◽  
N Almukthar ◽  
L Cabianca ◽  
...  
Keyword(s):  
Vaccine Design ◽  
Design Strategy ◽  
Spike Protein ◽  
Pathological Effect ◽  
Technical Data ◽  
Binding Effect ◽  
New Strategy ◽  
Rare Side Effect ◽  
New Generation

Related the need to search new strategy in vaccine design in order to reduce also some rare effect like trombosys for some registered products it is interesting the role played by the SPIKE RGD domain. The binding with molecules like Fibronectin is a process that must to be deeply investigated. A better understanding in this process can be used to improve safety of the new generation of COVID vaccine. The rare effect like thrombosis recognized by regulatory agency produced a modification of technical data sheet of some vaccine so the phenomena Is interesting to be more investigated. Spike protein and its domains are involved in producing pathological effect of the COVID-19 disease. What it is interesting is that some pathological effect of this pathology are similar to some rare side effect produced by some COVID-19 vaccine classes. After a review of interesting literature related this topics is submitted an experimental projects able to verify in vitro the spike procoaugulant property.

Visualization and Manipulation of Molecular Motion in Solid State through Photo-Induced Clusteroluminescence

2019 ◽  
Author(s):  
Haoke Zhang ◽  
Lili Du ◽  
Lin Wang ◽  
Junkai Liu ◽  
Qing Wan ◽  
...  
Keyword(s):  
Quantum Mechanics ◽  
Excited State ◽  
Solid State ◽  
Light Source ◽  
Molecular Motion ◽  
Molecular Machine ◽  
Conjugated Molecules ◽  
Time Resolved ◽  
Packing Structure ◽  
New Strategy

<p>Building molecular machine has long been a dream of scientists as it is expected to revolutionize many aspects of technology and medicine. Implementing the solid-state molecular motion is the prerequisite for a practical molecular machine. However, few works on solid-state molecular motion have been reported and it is almost impossible to “see” the motion even if it happens. Here the light-driven molecular motion in solid state is discovered in two non-conjugated molecules <i>s</i>-DPE and <i>s</i>-DPE-TM, resulting in the formation of excited-state though-space complex (ESTSC). Meanwhile, the newly formed ESTSC generates an abnormal visible emission which is termed as clusteroluminescence. Notably, the original packing structure can recover from ESTSC when the light source is removed. These processes have been confirmed by time-resolved spectroscopy and quantum mechanics calculation. This work provides a new strategy to manipulate and “see” solid-state molecular motion and gains new insights into the mechanistic picture of clusteroluminescence.<br></p>

Incorporation of Vibration Control in Determination of Structural Parameters of Gear Systems

1998 ◽  
Author(s):  
Y. Wang ◽  
W. J. Zhang ◽  
C. M. Kalker-Kalkman ◽  
Q. Li
Keyword(s):  
Vibration Control ◽  
Structural Parameters ◽  
Design Strategy ◽  
Design Variables ◽  
Conflicting Objectives ◽  
Pareto Sets ◽  
New Strategy ◽  
System Vibration ◽  
Gear Systems

Abstract A new design strategy of gear system is proposed in this paper. Traditionally, development of gear systems undergoes as such. First gear structural parameters are determined. Then control of dynamic behaviours such as control of vibration is dealt with, where gear structural parameters cannot be changed any more. The new strategy suggests that during the design process of determining gear structure parameters, vibration control is taken into account. In order to see the effects of such a design strategy, an optimal design model is developed which contains two conflicting objectives, system vibration and system volume. The design variables include both discrete ones and continuous ones. Genetic algorithm, together with Pareto sets, is employed to solve this complex optimal problem. Through the simulation studies on selected cases, improvement on the system vibration control is shown with this new design strategy.

Tricking Enzymes In Living Cells: A Mechanism-Based Strategy For Design of DNA Topoisomerase Biosensors

2021 ◽  
Author(s):  
Sai Ba ◽  
Guangpeng Gao ◽  
Tianhu Li ◽  
Hao Zhang
Keyword(s):  
Design Strategy ◽  
Living Cells ◽  
Molecular Probes ◽  
Chemical Bonds ◽  
Dna Topoisomerase ◽  
Dna Topoisomerases ◽  
Catalytic Activities ◽  
New Strategy ◽  
Clinical Tools ◽  
Catalytic Cycles

Abstract Most activity-based molecular probes are designed to target enzymes that catalyze the breaking of chemical bonds and the conversion of a unimolecular substrate into bimolecular products. However, DNA topoisomerases are a class of enzymes that alter DNA topology without producing any molecular segments during catalysis, which hinders the development of practical methods for diagnosing these key biomarkers in living cells. Here, we established a new strategy for the effective sensing of the expression levels and catalytic activities of topoisomerases in cell-free systems and human cells. Using our newly designed biosensors, we tricked DNA topoisomerases within their catalytic cycles to switch on fluorescence and resume new rounds of catalysis. Considering that human topoisomerases have been widely recognized as biomarkers for multiple cancers and identified as promising targets for several anticancer drugs, we believe that these DNA-based biosensors and our design strategy would greatly benefit the future development of clinical tools for cancer diagnosis and treatment.

scholarly journals Effects of Transition Elements on the Structural, Elastic Properties and Relative Phase Stability of L12 γ′-Co3Nb from First-Principles Calculations

Metals ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 933
Author(s):  
Cuiping Wang ◽  
Chi Zhang ◽  
Yichun Wang ◽  
Jiajia Han ◽  
Weiwei Xu ◽  
...  
Keyword(s):  
Elastic Properties ◽  
First Principles ◽  
Temperature Stability ◽  
Alloying Elements ◽  
First Principles Calculations ◽  
High Temperature Stability ◽  
Transition Elements ◽  
Transfer Energy ◽  
Positive Role ◽  
Calculation Results

In order to explore novel light-weight Co-Nb-based superalloys with excellent performance, we studied the effects of alloying elements including Sc, Ti, V, Cr, Mn, Fe, Ni, Y, Zr, Mo, Tc, Ru, Rh, Pd, Hf, Ta, W, Re, Os, Ir and Pt on the structural stability, elastic and thermodynamic properties of γ′-Co3Nb through first-principles calculations. The results of transfer energy indicate that Y, Zr, Hf and Ta have a strong preference for Nb sites, while Ni, Rh, Pd, Ir and Pt have a strong tendency to occupy the Co sites. In the ground state, the addition of alloying elements plays a positive role in improving the stability of γ′-Co3Nb compound. The order of stabilizing effect is as follows: Ti > Ta > Hf > Pt > Ir > Zr > Rh > V > Ni > W > Sc > Mo > Pd > Re > Ru. Combining the calculation results of elastic properties and electronic structure, we found that the addition of alloying elements can strengthen the mechanical properties of γ′-Co3Nb, and the higher spatial symmetry of electrons accounts for improving the shear modulus of γ′-Co3Nb compound. At finite temperatures, Ti, Ta, Hf, Pt, Ir, Zr and V significantly expand the stabilization temperature range of the γ′ phase and are potential alloying elements to improve the high-temperature stability of the γ′-Co3Nb compounds.

scholarly journals Tricking enzymes in living cells: a mechanism-based strategy for design of DNA topoisomerase biosensors

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Sai Ba ◽  
Guangpeng Gao ◽  
Tianhu Li ◽  
Hao Zhang
Keyword(s):  
Design Strategy ◽  
Living Cells ◽  
Molecular Probes ◽  
Chemical Bonds ◽  
Dna Topoisomerase ◽  
Dna Topoisomerases ◽  
Catalytic Activities ◽  
New Strategy ◽  
Clinical Tools ◽  
Catalytic Cycles

AbstractMost activity-based molecular probes are designed to target enzymes that catalyze the breaking of chemical bonds and the conversion of a unimolecular substrate into bimolecular products. However, DNA topoisomerases are a class of enzymes that alter DNA topology without producing any molecular segments during catalysis, which hinders the development of practical methods for diagnosing these key biomarkers in living cells. Here, we established a new strategy for the effective sensing of the expression levels and catalytic activities of topoisomerases in cell-free systems and human cells. Using our newly designed biosensors, we tricked DNA topoisomerases within their catalytic cycles to switch on fluorescence and resume new rounds of catalysis. Considering that human topoisomerases have been widely recognized as biomarkers for multiple cancers and identified as promising targets for several anticancer drugs, we believe that these DNA-based biosensors and our design strategy would greatly benefit the future development of clinical tools for cancer diagnosis and treatment. Graphical Abstract

ON THE DIFFERENT VELOCITIES OF INLET BOUNDARY CONDITIONS FOR HUMAN ARM ANALYSIS OF ARTERIAL FLOW USING ONE-WAY FLUID–SOLID COUPLING

2021 ◽  
pp. 2150049
Author(s):  
Quanyu Wu ◽  
Liu Xiaojie ◽  
Liu Meijun ◽  
Pan Lingjiao ◽  
Qian Chunqi
Keyword(s):  
Shear Stress ◽  
Boundary Conditions ◽  
Static Pressure ◽  
Stress Distributions ◽  
Human Arm ◽  
Arterial Model ◽  
New Strategy ◽  
Calculation Results ◽  
Wall Deformation ◽  
Dynamics Simulations

Simulations for blood hydrodynamic problems have been still largely incomplete despite years of research, especially for the inlet of boundary conditions that served as an essential part in computational fluid dynamics simulations of blood flow in human arteries. In this paper, the four different velocities of inlet boundary conditions were tested and compared in the human arm arterial model developed by us previously. Based on the selected points of nine key areas in the blood model,[Formula: see text] we analyzed the calculation results of pressure and shear stress distributions in detail. Our results show that they are changeable in different [Formula: see text] (different peak velocities of inlet boundary). The results further show that the static pressure of the aortic tree is higher than the static pressure of the branch, while the shear stress of the aortic tree is lower than the shear stress of the branch. On the other hand, the velocities changed in different [Formula: see text], the vessel walls of max total deformation appear in the middle radial obviously, compared with the equivalent and shear stress show at the entrance and bifurcations. In all, the simulation results of the brachial arteries provide the wall deformation, pressure and shear stress characteristics in different [Formula: see text], and offer a new strategy to study the two-way coupling of hemodynamics in the arm arterial model.

Experimental Evidence of the Thermal Cloak Based on the Path Design of the Heat Flux

2018 ◽  
Vol 140 (10) ◽  
Author(s):  
Xiao He ◽  
Tianzhi Yang ◽  
Linzhi Wu
Keyword(s):  
Heat Flux ◽  
Experimental Evidence ◽  
Thermal Protection ◽  
Large Degree ◽  
New Method ◽  
Material Parameters ◽  
Path Design ◽  
New Strategy ◽  
Transient Thermal ◽  
Blue Print

We recently showed theoretically that the infinite singularity of the thermal cloak designed by transformation thermodynamics could be eliminated by a new method—the path design of the heat flux without any approximation. In this paper, we present the experimental evidence of such a new strategy of thermal cloak, that is, a truly singularity-free thermal cloak. We fabricate such a transient thermal cloak device without using extreme material parameters. The experimental results show fully controlled, transient cloaking behavior, which are perfectly consistent with the theoretical derivations and simulated results. Since one can flexibly design the path of heat flux in the cloak, it has the large degree-of-freedom to construct thermal cloaks with the specific distributions of material parameters. The new method provides a new blue print for the transient thermal protection of a specific target.

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