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21.
Dr. Ayumi Hirano‐Iwata Yutaka Ishinari Dr. Hideaki Yamamoto Prof. Michio Niwano 《化学:亚洲杂志》2015,10(6):1266-1274
Ion channel proteins provide gated pores that allow ions to passively flow across cell membranes. Owing to their crucial roles in regulating transmembrane ion flow, ion channel proteins have attracted the attention of pharmaceutical investigators as drug targets for use in the studies of both therapeutics and side effects. In this review, we discuss the current technologies that are used in the formation of ion channel‐integrated bilayer lipid membranes (BLMs) in microfabricated devices as a potential platform for next‐generation drug screening systems. Advances in BLM fabrication methodology have allowed the preparation of BLMs in sophisticated formats, such as microfluidic, automated, and/or array systems, which can be combined with channel current recordings. A much more critical step is the integration of the target channels into BLMs. Current technologies for the functional reconstitution of ion channel proteins are presented and discussed. Finally, the remaining issues of the BLM‐based methods for recording ion channel activities and their potential applications as drug screening systems are discussed. 相似文献
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《印度化学会志》2023,100(3):100935
The educational value of nanofluids in several industrial and biological sectors, particularly in fluid movement systems known as peristalsis, has piqued researchers' interest in studying the peristaltic movement of nanofluids. Additionally, nanoparticles have crucial roles in many engineering and manufacturing processes, including those involving heat exchangers, cooling systems, boilers, MEMS, chemical engineering, laser diode arrays, and cool automotive engines. Various studies have been conducted on this subject. This is done by looking at how migratory gyrotactic microorganisms migrate through an artery that is anisotropically narrowing in a blood-based nanofluid that is non-Newtonian. To comprehend, the Powell-Eyring fluid model is used how the blood's rheology differs from that of a Newtonian fluid. Both Newtonian fluid characteristics and non-Newtonian traits can be seen in this fluid pattern. Equations for continuity, temperature, motile microbes, momentum, and concentration are used to create the mathematical formulation. The series solutions, which are produced using perturbation theory solutions are discussed using graphs for all dominant parameters. Discussion also includes the distribution of temperature, velocity, and swimming microorganisms. Additionally, the effects of wall shear stress, the Nusselt and Sherwood numbers, as well as the phenomena of trapping, are all examined in detail and shown in the graphs. Entropy generation analyses have also been undertaken. The investigation also reveals a crucial behaviour in the use of the heart-lung engine for extracorporeal blood circulation in medicine that may have an impact on the damage of red blood cells as a result of the large fluctuation in wall shear stress. When liquids are transported using arthro pumps and roller pumps in living organs, the results are likewise of significant use. The results are very helpful for executing particle movements in cardiac surgery and may be applicable to the fluid peristaltic pump used in haemodialysis. 相似文献
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Here we describe the story behind the link between molecular chirality and macroscopic phenomena, the latter being a probe for the direct assignment of absolute configuration of chiral molecules. First, a brief tour of the history of molecular stereochemistry, starting with the classic experiment reported by Pasteur in 1848 on the separation of enantiomorphous crystals of a salt of tartaric acid, and his conclusion that the molecules of life are chiral of single-handedness. With time, this study raised, inter alia, two fundamental questions: the absolute configuration of chiral molecules and how a molecule of given configuration shapes the enantiomorphous morphology of its crystal. As for the first question, following the beginning of crystal structure determination by X-ray diffraction in 1912, it took almost 40 years before Bijvoet assigned molecular chirality through the esoteric method involving anomalous X-ray scattering. We have been able to address and link both questions through ‘everyday concepts of left and right’ (in the words of Jack Dunitz) by the use of ‘tailor-made’ auxiliaries. By such means, it proved possible to reveal, through morphology, etch patterns, epitaxy and symmetry reduction of both chiral and, paradoxically, centrosymmetric crystals, the basic chiral symmetry of the molecules of life, the α-amino acids and sugars. 相似文献
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Elastic-inertial focusing has attracted increasing interest in recent years due to the three-dimensional (3D) single-train focusing ability it offers. However, multi-train focusing, instead of single-train focusing, was observed in viscoelastic fluids with low elasticity as a result of the competition between inertia effect and viscoelasticity effect. To address this issue, we employed the secondary flow to facilitate single-train elastic-inertial focusing in low elasticity viscoelastic fluids. A three-section contraction-expansion channel was designed to induce the secondary flow to pinch the multiplex focusing trains into a single one exactly at the channel centerline. After demonstrating the focusing process and mechanism in our device, we systematically explored and discussed the effects of particle diameter, operational flow rate, polymer concentration, and channel dimension on particle focusing performances. Our device enables single-train focusing of particles in viscoelastic fluids with low elasticity, and offers advantages of planar single-layer structure, and sheathless, external-field free operation. 相似文献
27.
Gaetano D'Avino 《Electrophoresis》2021,42(21-22):2293-2302
The migration of a spherical particle immersed in a viscoelastic liquid flowing in a microchannel with a triangular cross-section is investigated by direct numerical simulations under inertialess conditions. The viscoelastic fluid is modeled through two constitutive equations to investigate the effect of the second normal stress difference and the resulting secondary flows on the migration phenomenon. The results are presented in terms of trajectories followed by the particles released at different initial positions over the channel cross-section in a wide range of Weissenberg numbers and confinement ratios. Particles suspended in a fluid with a negligible second normal stress difference migrate toward the channel centerline or the closest wall, depending on their initial position. A much more complex dynamics is found for particles suspended in a fluid with a relevant second normal stress difference due to the appearance of secondary flows that compete with the migration phenomenon. Depending on the Weissenberg number and confinement ratio, additional equilibrium positions (points or closed orbits) may appear. In this case, the channel centerline becomes unstable and the particles are driven to the corners or “entrapped” in recirculation regions within the channel cross-section. The inversion of the centerline stability can be exploited to design efficient size-based separation devices. 相似文献
28.
大环分子如环糊精、冠醚等因具备独特的空腔结构, 能够通过主-客体相互作用实现对分子、离子的特异性识别, 因此常被应用于人工跨膜离子传输系统的研究和开发. 与天然的通道蛋白相比, 大环分子具有价格低廉、性质稳定、结构易于修饰和功能化等诸多优点, 因而备受科研工作者们的关注. 本综述详细介绍了大环分子在人工离子通道领域中的研究进展, 按照不同的大环分子进行分类, 系统归纳了基于大环结构的人工跨膜通道的制备方法、结构调控以及其在生物医药领域中的潜在应用. 最后对大环类人工离子通道做了简要的总结和展望, 该综述对于发展新型人工离子通道以及发掘其潜在的应用价值具有重要意义. 相似文献
29.
Long Cheng Haonan Yang Xingyu Chen Guozhen Liu Dr. Yanan Guo Prof. Gongping Liu Prof. Wanqin Jin 《化学:亚洲杂志》2021,16(20):3162-3169
Graphene oxide (GO) is a promising two-dimensional building block for fabricating high-performance gas separation membranes. Whereas the tortuous transport pathway may increase the transport distance and lead to a low gas permeation rate, introducing spacers into GO laminates is an effective strategy to enlarge the interlayer channel for enhanced gas permeance. Herein, we propose to intercalate CO2-philic MIL-101(Cr) metal-organic framework nanocrystals into the GO laminates to construct a 2D/3D hybrid structure for gas separation. The interlayer channels were partially opened up to accelerate gas permeation. Meanwhile, the intrinsic pores of MIL-101 provided additional transport pathways, and the affinity of MIL-101 to CO2 molecules resulted in higher H2/CO2 diffusion selectivity, leading to a simultaneous enhancement in gas permeance and separation selectivity. The MIL-101(Cr)/GO membrane with optimal structures exhibited outstanding and stable mixed-gas separation performance with H2 permeance of 67.5 GPU and H2/CO2 selectivity of 30.3 during the 120-h continuous test, demonstrating its potential in H2 purification application. 相似文献
30.
An automated NMR chemical shift assignment algorithm was developed using multi-objective optimization techniques. The problem is modeled as a combinatorial optimization problem and its objective parameters are defined separately in different score functions. Some of the heuristic approaches of evolutionary optimization are employed in this problem model. Both, a conventional genetic algorithm and multi-objective methods, i.e., the non-dominated sorting genetic algorithms II and III (NSGA2 and NSGA3), are applied to the problem. The multi-objective approaches consider each objective parameter separately, whereas the genetic algorithm followed a conventional way, where all objectives are combined in one score function. Several improvement steps and repetitions on these algorithms are performed and their combinations are also created as a hyper-heuristic approach to the problem. Additionally, a hill-climbing algorithm is also applied after the evolutionary algorithm steps. The algorithms are tested on several different datasets with a set of 11 commonly used spectra. The test results showed that our algorithm could assign both sidechain and backbone atoms fully automatically without any manual interactions. Our approaches could provide around a 65% success rate and could assign some of the atoms that could not be assigned by other methods. 相似文献