Development of Synthetic Strategies to Access Optically Pure Feringa’s Motors

Synthesis ◽  
2021 ◽  
Author(s):  
Yu-Nan Qin ◽  
Chen Zhang ◽  
Quan Li ◽  
Guang-Yan Du
Keyword(s):  
Smart Materials ◽  
Molecular Motors ◽  
Large Scale ◽  
Molecular Motor ◽  
Short Review ◽  
Chiral Auxiliary ◽  
Great Promise ◽  
First And Second Generation ◽  
Optically Pure ◽  
Intrinsic Feature

Light-driven unidirectional molecular motor has gained enormous attention since the pioneering work by Prof. Ben L. Feringa in 1999 and it holds great promise in next generation smart materials. The intrinsic feature of point chirality and helicity of these motor molecules requires efficient strategies to access their optically pure form especially when chirality-sensitive materials are fabricated. In this short review, we will summarize synthetic strategies to access optically pure first and second generation molecular motors. Generally, three strategies will be discussed including direct asymmetric synthesis, chiral auxiliary method and resolving agent aided chiral separation. We expect this review can ignite the enthusiasm of synthetic chemists to address very fundamental but unavoidable synthetic questions for chiral alkene based molecular motors concerning their large scale applications.

STM STUDIES ON MOLECULAR ROTORS AND MOTORS

2018 ◽  
Vol 25 (Supp01) ◽  
pp. 1841004 ◽  
Author(s):  
CHEN NI ◽  
JUN-ZHONG WANG
Keyword(s):  
Molecular Motors ◽  
Large Scale ◽  
Molecular Motor ◽  
Translational Motion ◽  
Solid Surfaces ◽  
Atomic Scale ◽  
Molecular Rotors ◽  
Scanning Tunneling ◽  
Molecular Rotor ◽  
Tunneling Microscopy

Molecular motor is a nanoscale machine that consumes energy to produce work via the unidirectional and controlled movement. They are universal in nature and essential to numerous processes of life. When mounted onto solid surfaces, scanning tunneling microscopy (STM) is a powerful technique to characterize the molecular rotors and motors due to the atomic-scale resolution coupled with its ability to track the motion of molecular rotor and motor over time. Moreover, the molecular rotors and motors can be powered by STM tip through injecting tunneling electrons. This review addresses recent advances in the STM studies of the structure, motion, and manipulation of molecular rotors and motors. The developments of surface-mounted azimuthal and altitudinal rotor and motors, large-scale array of molecular rotors, as well as the molecular motors with translational motion will be addressed.

4D printing technology, modern era: A short review

2020 ◽  
pp. 92-111
Author(s):  
Khodadad Mostakim ◽  
Nahid Imtiaz Masuk ◽  
Md. Rakib Hasan ◽  
Md. Shafikul Islam
Keyword(s):  
Smart Materials ◽  
Computer Aided Design ◽  
Short Review ◽  
Stimuli Responsive ◽  
4D Printing ◽  
Space Applications ◽  
Printing Technology ◽  
Practical Applications ◽  
Biomedical Technologies ◽  
Novel Material

The advancement in 3D printing has led to the rapid growth of 4D printing technology. Adding time, as the fourth dimension, this technology ushered the potential of a massive evolution in fields of biomedical technologies, space applications, deployable structures, manufacturing industries, and so forth. This technology performs ingenious design, using smart materials to create advanced forms of the 3-D printed specimen. Improvements in Computer-aided design, additive manufacturing process, and material science engineering have ultimately favored the growth of 4-D printing innovation and revealed an effective method to gather complex 3-D structures. Contrast to all these developments, novel material is still a challenging sector. However, this short review illustrates the basic of 4D printing, summarizes the stimuli responsive materials properties, which have prominent role in the field of 4D technology. In addition, the practical applications are depicted and the potential prospect of this technology is put forward.

scholarly journals A model of processive walking and slipping of kinesin-8 molecular motors

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ping Xie
Keyword(s):  
Single Molecule ◽  
Molecular Motors ◽  
External Load ◽  
Molecular Motor ◽  
Velocity Versus ◽  
Stick Slip ◽  
Load Dependence ◽  
Chemomechanical Coupling ◽  
Similarities And Differences ◽  
Stick Slip Motion

AbstractKinesin-8 molecular motor can move with superprocessivity on microtubules towards the plus end by hydrolyzing ATP molecules, depolymerizing microtubules. The available single molecule data for yeast kinesin-8 (Kip3) motor showed that its superprocessive movement is frequently interrupted by brief stick–slip motion. Here, a model is presented for the chemomechanical coupling of the kinesin-8 motor. On the basis of the model, the dynamics of Kip3 motor is studied analytically. The analytical results reproduce quantitatively the available single molecule data on velocity without including the slip and that with including the slip versus external load at saturating ATP as well as slipping velocity versus external load at saturating ADP and no ATP. Predicted results on load dependence of stepping ratio at saturating ATP and load dependence of velocity at non-saturating ATP are provided. Similarities and differences between dynamics of kinesin-8 and that of kinesin-1 are discussed.

scholarly journals Molecules as tracers of galaxy evolution

2012 ◽  
Vol 8 (S292) ◽  
pp. 199-208 ◽  
Author(s):  
Susanne Aalto
Keyword(s):  
Black Holes ◽  
Star Formation ◽  
High Resolution ◽  
Galaxy Evolution ◽  
Large Scale ◽  
Short Review ◽  
Stimulated Emission ◽  
Molecular Gas ◽  
Infrared Galaxies ◽  
Luminous Infrared Galaxies

AbstractStudying the molecular phase of the interstellar medium in galaxies is fundamental for the understanding of the onset and evolution of star formation and the growth of supermassive black holes. We can use molecules as observational tools exploiting them as tracers of chemical, physical and dynamical conditions. In this short review, key molecules (e.g. HCN, HCO+, HNC, HC3N, CN, H3O+) in identifying the nature of buried activity and its evolution are discussed including some standard astrochemical scenarios. Furthermore, we can use IR excited molecular emission to probe the very inner regions of luminous infrared galaxies (LIRGs) allowing us to get past the optically thick dust barrier of the compact obscured nuclei, e.g. in the dusty LIRG NGC4418. High resolution studies are often necessary to separate effects of excitation and radiative transport from those of chemistry - one example is absorption and effects of stimulated emission in the ULIRG Arp220. Finally, molecular gas in large scale galactic outflows is briefly discussed.

scholarly journals Evaluation of an Interprofessional Problem-based Learning Module on Care of Persons Living with HIV/AIDS

2010 ◽  
Vol 1 (2) ◽  
Author(s):  
Marcel D'Eon ◽  
Peggy Proctor ◽  
Jane Cassidy ◽  
Nora McKee ◽  
Krista Trinder
Keyword(s):  
Student Satisfaction ◽  
Interprofessional Education ◽  
Large Scale ◽  
Interprofessional Collaboration ◽  
Learning Experience ◽  
Problem Based Learning ◽  
Great Promise ◽  
Persons Living With Hiv ◽  
Post Test ◽  
Hiv Aids

Background: Interprofessional education (IPE) holds great promise in continuing to reform the management of complex chronic conditions such as HIV/AIDS, and Problem-based Learning (PBL) is a suitable format for IPE. This study aimed to evaluate the effectiveness of a large scale, compulsory interprofessional PBL module on HIV/AIDS education. In 2004, 30 physical therapy and 30 medical students at the University of Saskatchewan engaged in the HIV/AIDS PBL module. By 2007 over 300 students from seven healthcare programs were involved.Methods and Findings: The module was evaluated over the years using student satisfaction surveys, focus groups, self-assessments, and in 2007 with written pretest/post-tests. Students rated the learning experience about both HIV/AIDS and about interprofessional collaboration, at 4 or 5 out of 6 and effect sizes fell between d = .70 and 3.19. That only one pre-test/post-test study was conducted at a single institution is one of the limitations of this study.Conclusions: Students generally thought highly of the interprofessional PBL module on HIV/AIDS and learned a considerable amount. Although more research is needed to substantiate the self-assessment data, establish what and how much is being learned, and compare PBL to alternative methodologies, PBL is a promising approach to IPE.

Molecular Motors: Force and Movement Generated by Single Myosin II Molecules

Physiology ◽  
2002 ◽  
Vol 17 (5) ◽  
pp. 213-218 ◽  
Author(s):  
Caspar Rüegg ◽  
Claudia Veigel ◽  
Justin E. Molloy ◽  
Stephan Schmitz ◽  
John C. Sparrow ◽  
...  
Keyword(s):  
Optical Tweezers ◽  
Single Molecule ◽  
Molecular Motors ◽  
Molecular Motor ◽  
Myosin Ii ◽  
Force Production ◽  
Myosin Isoforms ◽  
Single Molecule Level ◽  
Recent Developments ◽  
Muscle Myosin

Muscle myosin II is an ATP-driven, actin-based molecular motor. Recent developments in optical tweezers technology have made it possible to study movement and force production on the single-molecule level and to find out how different myosin isoforms may have adapted to their specific physiological roles.

scholarly journals Molecular mechanisms for microtubule length regulation by kinesin-8 and XMAP215 proteins

2014 ◽  
Vol 4 (6) ◽  
pp. 20140031 ◽  
Author(s):  
Louis Reese ◽  
Anna Melbinger ◽  
Erwin Frey
Keyword(s):  
Molecular Motors ◽  
Molecular Mechanisms ◽  
Molecular Motor ◽  
Mutual Exclusion ◽  
High Growth ◽  
Dependent Manner ◽  
Dynamic Regulation ◽  
Filament Dynamics ◽  
Length Regulation ◽  
The Stability

The cytoskeleton is regulated by a plethora of enzymes that influence the stability and dynamics of cytoskeletal filaments. How microtubules (MTs) are controlled is of particular importance for mitosis, during which dynamic MTs are responsible for proper segregation of chromosomes. Molecular motors of the kinesin-8 protein family have been shown to depolymerize MTs in a length-dependent manner, and recent experimental and theoretical evidence suggests a possible role for kinesin-8 in the dynamic regulation of MTs. However, so far the detailed molecular mechanisms of how these molecular motors interact with the growing MT tip remain elusive. Here we show that two distinct scenarios for the interactions of kinesin-8 with the MT tip lead to qualitatively different MT dynamics, including accurate length control as well as intermittent dynamics. We give a comprehensive analysis of the regimes where length regulation is possible and characterize how the stationary length depends on the biochemical rates and the bulk concentrations of the various proteins. For a neutral scenario, where MTs grow irrespective of whether the MT tip is occupied by a molecular motor, length regulation is possible only for a narrow range of biochemical rates, and, in particular, limited to small polymerization rates. By contrast, for an inhibition scenario, where the presence of a motor at the MT tip inhibits MT growth, the regime where length regulation is possible is extremely broad and includes high growth rates. These results also apply to situations where a polymerizing enzyme like XMAP215 and kinesin-8 mutually exclude each other from the MT tip. Moreover, we characterize the differences in the stochastic length dynamics between the two scenarios. While for the neutral scenario length is tightly controlled, length dynamics is intermittent for the inhibition scenario and exhibits extended periods of MT growth and shrinkage. On a broader perspective, the set of models established in this work quite generally suggest that mutual exclusion of molecules at the ends of cytoskeletal filaments is an important factor for filament dynamics and regulation.

Total Productive Maintenance: Competing or Complementary to other Initiatives?

2013 ◽  
Vol 315 ◽  
pp. 472-476
Author(s):  
Adnan Hj. Bakri ◽  
Abdul Rahman Abdul Rahim ◽  
Noordin Mohd Yusof
Keyword(s):  
Large Scale ◽  
Manufacturing Industry ◽  
Short Review ◽  
The Other ◽  
Total Quality ◽  
Total Productive Maintenance ◽  
Quality Initiatives ◽  
Practical Applications ◽  
Manufacturing Organization

The objective of this short review paper is to examine the practical applications of Total Productive Maintenance (TPM) in the manufacturing industry. In this short review, an attempt was made to critically discuss the previous literatures related to TPM with the other established quality initiatives in the manufacturing, such as Total Quality Management (TQM) and Just-In-Time practice (JIT). This literature review-based research revealed an important research gaps related to TPM. The significance role of TPM as an important complementary to either TQM or JIT initiative is observed not been well addressed in the available literatures. Most of the researches available investigate these initiatives separately, focuses on the other element rather than addressing on the significant role of TPM as one of the main thrust. The separate implementation of such quality initiatives in the manufacturing organization means the requirement of large scale human, financial and technical resources as well the associated problems of running competing project in the company. The outcomes from this review justify the needs of further research in the area of TPM integration with other available initiatives, to further enhance its methodology aimed at solidifying its philosophy towards more realistic practical applications.

scholarly journals Active and Unidirectional Acceleration of Biaryl Rotation by a Molecular Motor

2019 ◽  
Author(s):  
Edgar Uhl ◽  
Peter Mayer ◽  
Henry Dube
Keyword(s):  
Potential Energy ◽  
Motor Unit ◽  
Rate Constants ◽  
Molecular Motors ◽  
Molecular Motor ◽  
Molecular Machine ◽  
Single Bond ◽  
Bond Rotation ◽  
Immense Potential

Light driven molecular motors possess immense potential as central driving units for future nanotechnology. Integration into larger molecular setups and transduction of their mechanical motions represents the current frontier of research. Here we report on an integrated molecular machine setup allowing to transmit potential energy from a motor unit unto a remote receiving entity. The setup consists of a motor unit connected covalently to a distant and sterically strongly encumbered biaryl receiver. By action of the motor unit single bond rotation of the receiver is strongly accelerated and forced to proceed unidirectionally. The transmitted potential energy is directly measured as the extent to which energy degeneration is lifted in the thermal atropisomerization of this biaryl. Energy degeneracy is reduced by as much as 2.3 kcal/mol and rate accelerations up to 2x10<sup>5</sup> fold in terms of rate constants are achieved.<br><b></b>

scholarly journals Potential uses of biomass from fast-growing crop miscanthus×giganteus

2012 ◽  
Vol 66 (2) ◽  
pp. 223-233 ◽  
Author(s):  
Nada Babovic ◽  
Gordana Drazic ◽  
Ana Djordjevic
Keyword(s):  
Panicum Virgatum ◽  
Large Scale ◽  
Low Cost ◽  
Water Concentration ◽  
High Water ◽  
Perennial Grasses ◽  
Great Promise ◽  
Cellulose Content ◽  
Production Chain ◽  
Miscanthus Giganteus

There is an increasing interest in perennial grasses as a renewable source of bioenergy and feedstock for second-generation cellulosic biofuels. Switchgrass (Panicum virgatum) and miscanthus (Miscanthus?giganteus), belonging to the parennial grasses group, are the major lignocellulosic materials being studied today as sources for direct energy production, biofuels, bioremediation and other. They have the ability to grow at low cost on marginal land where they will not compete with the traditional food crops. Miscanthus?giganteus possesses a number of advantages in comparison with the other potential energy crops such as are: high yields, low moisture content at harvest, high water and nitrogen use efficiencies, low need for annual agronomic inputs such as fertilizers and pesticides, high cellulose content, non-invasive character, low susceptibility to pests and diseases and broad adaptation to temperate growing environments. The main problems are low rate of survival during the first winter after the creation of plantation and the relatively high establishment costs. Miscanthus?giganteus is grown primarily for heat and electricity generation but can also be used to produce transport fuels. Miscanthus biomass has a very good combustion quality due to its low water concentration as well as its low Cl, K, N, S and ash concentrations compared to other lignocellulose plants. It is expected that miscanthus will provide cheaper and more sustainable source of cellulose for production of bioethanol than annual crops such as corn. Miscanthus has great promise as a renewable energy source, but it can only be realised when the grass production has been optimised for large-scale commercial cultivation. However, further research is still needed to optimise agronomy of miscanthus, to develop the production chain and pre-treatment as well as to optimise energy conversation route to produce heat, electricity, and/or fuels from biomass, if miscanthus is to compete with fossil fuel use and be widely produced.

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