scholarly journals Multi-Enzyme Systems in Flow Chemistry

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 225
Author(s):  
Pedro Fernandes ◽  
Carla C. C. R. de Carvalho
Keyword(s):  
Metabolic Pathways ◽  
High Selectivity ◽  
Flow Chemistry ◽  
Cascade Reactions ◽  
Flow Reactors ◽  
Whole Cells ◽  
Operation Conditions ◽  
Recent Developments ◽  
Sound Environment ◽  
Key Aspects

Recent years have witnessed a growing interest in the use of biocatalysts in flow reactors. This merging combines the high selectivity and mild operation conditions typical of biocatalysis with enhanced mass transfer and resource efficiency associated to flow chemistry. Additionally, it provides a sound environment to emulate Nature by mimicking metabolic pathways in living cells and to produce goods through the systematic organization of enzymes towards efficient cascade reactions. Moreover, by enabling the combination of enzymes from different hosts, this approach paves the way for novel pathways. The present review aims to present recent developments within the scope of flow chemistry involving multi-enzymatic cascade reactions. The types of reactors used are briefly addressed. Immobilization methodologies and strategies for the application of the immobilized biocatalysts are presented and discussed. Key aspects related to the use of whole cells in flow chemistry are presented. The combination of chemocatalysis and biocatalysis is also addressed and relevant aspects are highlighted. Challenges faced in the transition from microscale to industrial scale are presented and discussed.

scholarly journals Cardiac Organoids to Model and Heal Heart Failure and Cardiomyopathies

Biomedicines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 563
Author(s):  
Magali Seguret ◽  
Eva Vermersch ◽  
Charlène Jouve ◽  
Jean-Sébastien Hulot
Keyword(s):  
Tissue Engineering ◽  
Drug Testing ◽  
Cardiac Tissue ◽  
Cardiac Tissue Engineering ◽  
Cardiac Cells ◽  
Cardiac Functions ◽  
Different Types ◽  
Recent Developments ◽  
Human Cardiac Tissue ◽  
Key Aspects

Cardiac tissue engineering aims at creating contractile structures that can optimally reproduce the features of human cardiac tissue. These constructs are becoming valuable tools to model some of the cardiac functions, to set preclinical platforms for drug testing, or to alternatively be used as therapies for cardiac repair approaches. Most of the recent developments in cardiac tissue engineering have been made possible by important advances regarding the efficient generation of cardiac cells from pluripotent stem cells and the use of novel biomaterials and microfabrication methods. Different combinations of cells, biomaterials, scaffolds, and geometries are however possible, which results in different types of structures with gradual complexities and abilities to mimic the native cardiac tissue. Here, we intend to cover key aspects of tissue engineering applied to cardiology and the consequent development of cardiac organoids. This review presents various facets of the construction of human cardiac 3D constructs, from the choice of the components to their patterning, the final geometry of generated tissues, and the subsequent readouts and applications to model and treat cardiac diseases.

Recent developments in enantioselective organocatalytic cascade reactions for the construction of halogenated ring systems

2021 ◽  
Author(s):  
Ana Maria Madeira Martins Faisca Phillips ◽  
Ana Maria Madeira Martins Faisca Phillips ◽  
Armando J. L. Pombeiro
Keyword(s):  
Cascade Reactions ◽  
Ring Systems ◽  
Recent Developments

scholarly journals Experimental Models for Studying HPV-Positive and HPV-Negative Penile Cancer: New Tools for An Old Disease

Cancers ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 460
Author(s):  
Beatriz Medeiros-Fonseca ◽  
Antonio Cubilla ◽  
Haissa Brito ◽  
Tânia Martins ◽  
Rui Medeiros ◽  
...  
Keyword(s):  
Mouse Models ◽  
Cell Lines ◽  
Penile Cancer ◽  
Hpv Infection ◽  
Experimental Models ◽  
In Vivo Models ◽  
Recent Developments ◽  
Key Aspects

Penile cancer is an uncommon malignancy that occurs most frequently in developing countries. Two pathways for penile carcinogenesis are currently recognized: one driven by human papillomavirus (HPV) infection and another HPV-independent route, associated with chronic inflammation. Progress on the clinical management of this disease has been slow, partly due to the lack of preclinical models for translational research. However, exciting recent developments are changing this landscape, with new in vitro and in vivo models becoming available. These include mouse models for HPV+ and HPV− penile cancer and multiple cell lines representing HPV− lesions. The present review addresses these new advances, summarizing available models, comparing their characteristics and potential uses and discussing areas that require further improvement. Recent breakthroughs achieved using these models are also discussed, particularly those developments pertaining to HPV-driven cancer. Two key aspects that still require improvement are the establishment of cell lines that can represent HPV+ penile carcinomas and the development of mouse models to study metastatic disease. Overall, the growing array of in vitro and in vivo models for penile cancer provides new and useful tools for researchers in the field and is expected to accelerate pre-clinical research on this disease.

scholarly journals Modeling the mind: Assessment of if…then… profiles as a window to shared and idiosyncratic psychological processes

2021 ◽  
Author(s):  
Vivian Zayas ◽  
Randy T. Lee ◽  
Yuichi Shoda
Keyword(s):  
Social Cognitive ◽  
Processing System ◽  
Cognitive Tasks ◽  
Affective Processing ◽  
Causal Inferences ◽  
Causal Processes ◽  
Recent Developments ◽  
Key Aspects ◽  
The Mind ◽  
Personality System

People’s behavior is characterized by stable if…then… profiles, or if in x situation then behavior a, but if in y situation then behavior b. But how do researchers conceptualize and measure if…then… profiles? Drawing from Cognitive-Affective Processing System (CAPS) theory, we discuss recent developments in assessing if…then… profiles, and how such profiles can provide a window for elucidating key aspects of the underlying personality system. Specifically, the Highly-Repeated Within-Person (HRWP) approach assesses how a behavior varies as a function of key features in a situation, and operationalizes if…then… profiles as regression betas. We illustrate how the HRWP approach can be applied to data from often-used social cognitive tasks, wherein an individual is exposed to a large number of situations that differ on a dimension that has been experimentally-manipulated by the researcher, and their behaviors to the situations are tracked. The HRWP approach allows researchers to more precisely assess a given individual’s if…then… pattern, make stronger causal inferences about a given individual’s personality system, and empirically investigate, rather than simply assume, if there are meaningful differences between individuals in the causal processes.

scholarly journals Pathway swapping: Toward modular engineering of essential cellular processes

2016 ◽  
Vol 113 (52) ◽  
pp. 15060-15065 ◽  
Author(s):  
Niels G. A. Kuijpers ◽  
Daniel Solis-Escalante ◽  
Marijke A. H. Luttik ◽  
Markus M. M. Bisschops ◽  
Francine J. Boonekamp ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Metabolic Pathways ◽  
Applied Research ◽  
Central Metabolism ◽  
Microbial Genomes ◽  
Cellular Processes ◽  
Recent Developments ◽  
One Step ◽  
Saccharomyces Kudriavzevii

Recent developments in synthetic biology enable one-step implementation of entire metabolic pathways in industrial microorganisms. A similarly radical remodelling of central metabolism could greatly accelerate fundamental and applied research, but is impeded by the mosaic organization of microbial genomes. To eliminate this limitation, we propose and explore the concept of “pathway swapping,” using yeast glycolysis as the experimental model. Construction of a “single-locus glycolysis” Saccharomyces cerevisiae platform enabled quick and easy replacement of this yeast’s entire complement of 26 glycolytic isoenzymes by any alternative, functional glycolytic pathway configuration. The potential of this approach was demonstrated by the construction and characterization of S. cerevisiae strains whose growth depended on two nonnative glycolytic pathways: a complete glycolysis from the related yeast Saccharomyces kudriavzevii and a mosaic glycolysis consisting of yeast and human enzymes. This work demonstrates the feasibility and potential of modular, combinatorial approaches to engineering and analysis of core cellular processes.

scholarly journals Manufacturing chemicals with light: any role in the circular economy?

2020 ◽  
Vol 378 (2176) ◽  
pp. 20190260
Author(s):  
M. Poliakoff ◽  
M. W. George
Keyword(s):  
Circular Economy ◽  
World Wide ◽  
Chemical Elements ◽  
Flow Chemistry ◽  
Scaling Up ◽  
Chemical Plants ◽  
The Sun ◽  
Organic Photochemistry ◽  
Recent Developments ◽  
Pharmaceutical Manufacture

We outline how recent developments in photochemistry can contribute to the realization of the 1912 vision of the pioneering Italian scientist Giacomo Ciamician, namely world-wide chemical-using industry-based chemical plants fuelled solely by the Sun. We then show how a combination of organic photochemistry and flow chemistry could contribute to the circular economy by harnessing the ability of light to provide the energy to promote reactions without the need for some of the added reagents that are necessary in more traditional chemical routes, so-called 'reagentless' chemistry. Photochemistry has a long history but recently it has undergone a renaissance, particularly with the rise in interest in photoredox chemistry. Continuous photoreactors offer a route to scaling up such reactions to a productivity needed for smaller scale pharmaceutical manufacture. We describe some reactor designs from our own laboratory and outline some of their applications. We then relate these to the requirements of the circular economy and the need to conserve the stocks of the less abundant chemical elements. This article is part of a discussion meeting issue ‘Science to enable the circular economy'.

scholarly journals Machine learning for human learners: opportunities, issues, tensions and threats

2020 ◽  
Author(s):  
Mary E. Webb ◽  
Andrew Fluck ◽  
Johannes Magenheim ◽  
Joyce Malyn-Smith ◽  
Juliet Waters ◽  
...  
Keyword(s):  
Machine Learning ◽  
Deep Learning ◽  
Ethical Issues ◽  
Practical Experience ◽  
Learning Systems ◽  
Learning System ◽  
Adaptive Behaviour ◽  
Recent Developments ◽  
Key Aspects ◽  
School Curricula

AbstractMachine learning systems are infiltrating our lives and are beginning to become important in our education systems. This article, developed from a synthesis and analysis of previous research, examines the implications of recent developments in machine learning for human learners and learning. In this article we first compare deep learning in computers and humans to examine their similarities and differences. Deep learning is identified as a sub-set of machine learning, which is itself a component of artificial intelligence. Deep learning often depends on backwards propagation in weighted neural networks, so is non-deterministic—the system adapts and changes through practical experience or training. This adaptive behaviour predicates the need for explainability and accountability in such systems. Accountability is the reverse of explainability. Explainability flows through the system from inputs to output (decision) whereas accountability flows backwards, from a decision to the person taking responsibility for it. Both explainability and accountability should be incorporated in machine learning system design from the outset to meet social, ethical and legislative requirements. For students to be able to understand the nature of the systems that may be supporting their own learning as well as to act as responsible citizens in contemplating the ethical issues that machine learning raises, they need to understand key aspects of machine learning systems and have opportunities to adapt and create such systems. Therefore, some changes are needed to school curricula. The article concludes with recommendations about machine learning for teachers, students, policymakers, developers and researchers.

scholarly journals Cascades, Catalysis and Chiral Ligand Control with SmI2; The Rebirth of a Reagent

2020 ◽  
Vol 74 (1) ◽  
pp. 18-22
Author(s):  
Áron Péter ◽  
David J. Procter
Keyword(s):  
Electron Transfer ◽  
Cascade Reactions ◽  
Single Electron ◽  
Radical Reactions ◽  
Chiral Ligand ◽  
Single Electron Transfer ◽  
Recent Developments ◽  
Radical Cascade

This review focuses on recent developments from our laboratory in the field of radical reactions mediated by the archetypal reductive single electron transfer (SET) reagent, SmI2. Namely, we have expanded the scope of reducible carbonyl moieties to esters and amides and have exploited the resultant ketyl radicals in radical cascade reactions that generate unprecedented scaffolds. Moreover, we have taken the first steps to address the long-standing challenges of catalysis and chiral ligand control associated with the reagent.

scholarly journals Enzymatic Bioreactors: An Electrochemical Perspective

Catalysts ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1232
Author(s):  
Simin Arshi ◽  
Mehran Nozari-Asbemarz ◽  
Edmond Magner
Keyword(s):  
Direct Electron Transfer ◽  
High Surface ◽  
High Surface Area ◽  
Enzyme Engineering ◽  
Future Perspective ◽  
Enzymatic System ◽  
Reaction Conditions ◽  
Flow Reactors ◽  
Recent Developments ◽  
Enzyme Cascades

Biocatalysts provide a number of advantages such as high selectivity, the ability to operate under mild reaction conditions and availability from renewable resources that are of interest in the development of bioreactors for applications in the pharmaceutical and other sectors. The use of oxidoreductases in biocatalytic reactors is primarily focused on the use of NAD(P)-dependent enzymes, with the recycling of the cofactor occurring via an additional enzymatic system. The use of electrochemically based systems has been limited. This review focuses on the development of electrochemically based biocatalytic reactors. The mechanisms of mediated and direct electron transfer together with methods of immobilising enzymes are briefly reviewed. The use of electrochemically based batch and flow reactors is reviewed in detail with a focus on recent developments in the use of high surface area electrodes, enzyme engineering and enzyme cascades. A future perspective on electrochemically based bioreactors is presented.

Comparison of Regional Lung Deformation Between Dynamic and Static CT Imagery Using Inverse Consistent Registration

2009 ◽  
Author(s):  
Ryan Amelon ◽  
Kai Ding ◽  
Kunlin Cao ◽  
Gary E. Christensen ◽  
Joseph M. Reinhardt ◽  
...  
Keyword(s):  
Image Data ◽  
Lung Mechanics ◽  
Ct Scans ◽  
Positive Pressure ◽  
Displacement Fields ◽  
Regional Patterns ◽  
Recent Developments ◽  
The Difference ◽  
Key Aspects ◽  
Lung Deformation

The mechanics of lung deformation is traditionally assessed at a whole-lung or lobar level. We submit that key aspects of lung mechanics maybe better understood by studying regional patterns of lung deformation by leveraging recent developments in tomographic imaging and image processing techniques. Our group has developed an inverse consistent registration technique for estimating local displacement distributions from paired lung CT volumes [1,2]. This facilitates the estimation of strain distributions and consequently, the regional patterns in volume change and its preferential directionalities (anisotropy in deformation). In this study, we use this novel method to compare regional deformation in the lungs between static and dynamic inflations in an adult sheep. Much of our research has focused on registration of static lung images at different positive end-expiratory pressures (PEEP). More recently, respiratory-gated CT scans of supine, positive-pressure inflated sheep lungs have been gathered in order to compare the displacement fields of a dynamically inflating lung to the static lung scans. The theory is that scanning a dynamically inflating lung will more accurately reflect natural deformation during breathing by realizing time-dependent mechanical properties (viscoelasticity). The downside to human dynamic lung imaging is the increased radiation dose necessary to acquire the image data across the respiratory cycle, though low-dose CT scans are an option [3]. This experiment observed the difference in strain distribution between dynamically inflated lungs versus static apneic lungs using the inverse consistent image registration developed in our lab.

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