scholarly journals Cellular Self-Digestion and Persistence in Bacteria

2021 ◽  
Vol 9 (11) ◽  
pp. 2269
Author(s):  
Sayed Golam Mohiuddin ◽  
Sreyashi Ghosh ◽  
Han G. Ngo ◽  
Shayne Sensenbach ◽  
Prashant Karki ◽  
...  
Keyword(s):  
Building Blocks ◽  
Review Article ◽  
Stress Conditions ◽  
The Self ◽  
Nutrient Depletion ◽  
Bacterial Persistence ◽  
Temporary Protection ◽  
Evolutionarily Conserved ◽  
Degradative Enzymes

Cellular self-digestion is an evolutionarily conserved process occurring in prokaryotic cells that enables survival under stressful conditions by recycling essential energy molecules. Self-digestion, which is triggered by extracellular stress conditions, such as nutrient depletion and overpopulation, induces degradation of intracellular components. This self-inflicted damage renders the bacterium less fit to produce building blocks and resume growth upon exposure to fresh nutrients. However, self-digestion may also provide temporary protection from antibiotics until the self-digestion-mediated damage is repaired. In fact, many persistence mechanisms identified to date may be directly or indirectly related to self-digestion, as these processes are also mediated by many degradative enzymes, including proteases and ribonucleases (RNases). In this review article, we will discuss the potential roles of self-digestion in bacterial persistence.

Formation of Carbon-Oxygen Bond Mediated by Hypervalent Iodine Reagents Under Metal-free Conditions

2020 ◽  
Vol 17 ◽  
Author(s):  
Ayesha Jalil ◽  
Yaxin O Yang ◽  
Zhendong Chen ◽  
Rongxuan Jia ◽  
Tianhao Bi ◽  
...  
Keyword(s):  
Natural Products ◽  
Bond Formation ◽  
Building Blocks ◽  
Review Article ◽  
Hypervalent Iodine ◽  
Metal Free ◽  
Bioactive Natural Products ◽  
The Past ◽  
Oxygen Bond ◽  
Privileged Scaffolds

: Hypervalent iodine reagents are a class of non-metallic oxidants have been widely used in the construction of several sorts of bond formations. This surging interest in hypervalent iodine reagents is essentially due to their very useful oxidizing properties, combined with their benign environmental character and commercial availability from the past few decades ago. Furthermore, these hypervalent iodine reagents have been used in the construction of many significant building blocks and privileged scaffolds of bioactive natural products. The purpose of writing this review article is to explore all the transformations in which carbon-oxygen bond formation occurred by using hypervalent iodine reagents under metal-free conditions

Stress-responsive properties of metallocenes in metallopolymers

2021 ◽  
Author(s):  
Ye Sha ◽  
Hao Zhang ◽  
Zhou Zhou ◽  
Zhenyang Luo
Keyword(s):  
Molecular Level ◽  
Building Blocks ◽  
Review Article ◽  
Stress Responsiveness

This review article combines the field of metallopolymers and stress-responsiveness on a molecular level, namely, metallocenes, as emerging stress-responsive building blocks for materials.

scholarly journals Self-Assembly of Shape-Tunable Oblate Colloidal Particles into Orientationally Ordered Crystals, Glassy Crystals and Plastic Crystals

Soft Matter ◽  
2021 ◽  
Author(s):  
Jiawei Lu ◽  
Xiangyu Bu ◽  
Xinghua Zhang ◽  
Bing Liu
Keyword(s):  
Crystal Structures ◽  
Self Assembly ◽  
Colloidal Particles ◽  
Building Blocks ◽  
Fundamental Question ◽  
The Self ◽  
Plastic Crystals ◽  
Self Assembled ◽  
Glassy Crystals ◽  
The Relationship

The shapes of colloidal particles are crucial to the self-assembled superstructures. Understanding the relationship between the shapes of building blocks and the resulting crystal structures is an important fundamental question....

Controllable Synthesis of Cobalt Porphyrin Nanocrystals through Micelle Confinement Self-Assembly

MRS Advances ◽  
2020 ◽  
Vol 5 (42) ◽  
pp. 2147-2155
Author(s):  
Sudi Chen ◽  
Xitong Ren ◽  
Shufang Tian ◽  
Jiajie Sun ◽  
Feng Bai
Keyword(s):  
Self Assembly ◽  
Water Oxidation ◽  
Separation Efficiency ◽  
Noncovalent Interactions ◽  
Building Blocks ◽  
The Self ◽  
Hexagonal Prism ◽  
Assembly Process ◽  
Surfactant Micelles ◽  
Cobalt Porphyrin

AbstractThe self-assembly of optically active building blocks into functional nanocrystals as high-activity photocatalysts is a key in the field of photocatalysis. Cobalt porphyrin with abundant catalytic properties is extensively studied in photocatalytic water oxidation and CO2 reduction. Here, we present the fabrication of cobalt porphyrin nanocrystals through a surfactant-assisted interfacial self-assembly process using Co-tetra(4-pyridyl) porphyrin as building block. The self-assembly process relies on the combined noncovalent interactions such as π-π stacking and axial Co-N coordination between individual porphyrin molecules within surfactant micelles. Tuning different reaction conditions (temperature, the ratio of co-solvent DMF) and types of surfactant, various nanocrystals with well-defined 1D to 3D morphologies such as nanowires, nanorods and nano hexagonal prism were obtained. Due to the ordered accumulation of molecules, the nanocrystals exhibit the properties of the enhanced capability of visible light capture and can conduce to improve the transport and separation efficiency of the photogenerated carriers, which is important for photocatalysis. Further studies of photocatalytic CO2 reduction are being performed to address the relationship between the size and shape of the nanocrystals with the photocatalytic activity.

A Dynamic Route to Structure and Function: Recent Advances in Imine-Based Organic Nanostructured Materials

2013 ◽  
Vol 66 (1) ◽  
pp. 9 ◽  
Author(s):  
Yi Liu ◽  
Zhan-Ting Li
Keyword(s):  
Self Assembly ◽  
Reaction System ◽  
Functional Materials ◽  
Building Blocks ◽  
The Self ◽  
Interlocked Molecules ◽  
Functional Aspects ◽  
Imine Bond ◽  
And Function ◽  
Dynamic Route

The chemistry of imine bond formation from simple aldehyde and amine precursors is among the most powerful dynamic covalent chemistries employed for the construction of discrete molecular objects and extended molecular frameworks. The reversible nature of the C=N bond confers error-checking and proof-reading capabilities in the self-assembly process within a multi-component reaction system. This review highlights recent progress in the self-assembly of complex organic molecular architectures that are enabled by dynamic imine chemistry, including molecular containers with defined geometry and size, mechanically interlocked molecules, and extended frameworks and polymers, from building blocks with preprogrammed steric and electronic information. The functional aspects associated with the nanometer-scale features not only place these dynamically constructed nanostructures at the frontier of materials sciences, but also bring unprecedented opportunities for the discovery of new functional materials.

scholarly journals Depression Survivors Among Emerging Adults: Their Healing Journey

2021 ◽  
Vol 7 (2) ◽  
pp. 47-65
Author(s):  
Wei Zhe Pui ◽  
Jamayah Saili
Keyword(s):  
Qualitative Study ◽  
Coping Strategies ◽  
Emerging Adults ◽  
Healing Process ◽  
Well Being ◽  
Building Blocks ◽  
Structured Interview ◽  
The Self ◽  
Healing Journey

This qualitative study explored the healing process of depression survivors among emerging adults with effective coping strategies utilised by them. A semi-structured interview was conducted on participants aged between 18-28 years old. A theme narrating the experience of the depression survivors were identified: The journey of healing - Crawling out of the quicksand. The survivors emphasised that to achieve healing, everything starts from within the self, and they had been putting in a lot of their extra efforts in helping themselves heal. They all went beyond recovery, where their efforts illustrated their focus on healing, thriving, and achieving optimal well-being upon recovery. Significantly, the relevance and applicability of the building blocks of Seligman’s PERMA model of well-being towards those efforts taken were revealed in the study. .

scholarly journals Supramolecular assemblies of organo-functionalised hybrid polyoxometalates: from functional building blocks to hierarchical nanomaterials

2022 ◽  
Author(s):  
Jamie M. Cameron ◽  
Geoffroy Guillemot ◽  
Theodor Galambos ◽  
Sharad S. Amin ◽  
Elizabeth Hampson ◽  
...  
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
Supramolecular Assemblies ◽  
The Self ◽  
Supramolecular Materials ◽  
Inorganic Hybrid ◽  
Hierarchical Nanomaterials

Organic–inorganic hybrid polyoxometalates are versatile building blocks for the self-assembly of functional supramolecular materials.

scholarly journals Modification of a Single Atom Affects the Physical Properties of Double Fluorinated Fmoc-Phe Derivatives

2021 ◽  
Vol 22 (17) ◽  
pp. 9634
Author(s):  
Moran Aviv ◽  
Dana Cohen-Gerassi ◽  
Asuka A. Orr ◽  
Rajkumar Misra ◽  
Zohar A. Arnon ◽  
...  
Keyword(s):  
Amino Acid ◽  
Physical Properties ◽  
Self Assembly ◽  
Deep Understanding ◽  
Building Blocks ◽  
The Self ◽  
Single Atom ◽  
Supramolecular Organization ◽  
Assembly Process ◽  
Wide Range

Supramolecular hydrogels formed by the self-assembly of amino-acid based gelators are receiving increasing attention from the fields of biomedicine and material science. Self-assembled systems exhibit well-ordered functional architectures and unique physicochemical properties. However, the control over the kinetics and mechanical properties of the end-products remains puzzling. A minimal alteration of the chemical environment could cause a significant impact. In this context, we report the effects of modifying the position of a single atom on the properties and kinetics of the self-assembly process. A combination of experimental and computational methods, used to investigate double-fluorinated Fmoc-Phe derivatives, Fmoc-3,4F-Phe and Fmoc-3,5F-Phe, reveals the unique effects of modifying the position of a single fluorine on the self-assembly process, and the physical properties of the product. The presence of significant physical and morphological differences between the two derivatives was verified by molecular-dynamics simulations. Analysis of the spontaneous phase-transition of both building blocks, as well as crystal X-ray diffraction to determine the molecular structure of Fmoc-3,4F-Phe, are in good agreement with known changes in the Phe fluorination pattern and highlight the effect of a single atom position on the self-assembly process. These findings prove that fluorination is an effective strategy to influence supramolecular organization on the nanoscale. Moreover, we believe that a deep understanding of the self-assembly process may provide fundamental insights that will facilitate the development of optimal amino-acid-based low-molecular-weight hydrogelators for a wide range of applications.

Regular High-Nuclearity Species from Square Building Blocks: A Triangular 3 × [2 × 2] Ni12 Complex Generated by the Self-assembly of Three [2 × 2] Ni4 Molecular Grids

2012 ◽  
Vol 51 (14) ◽  
pp. 7445-7447 ◽  
Author(s):  
Yurii S. Moroz ◽  
Serhiy Demeshko ◽  
Matti Haukka ◽  
Andriy Mokhir ◽  
Utpal Mitra ◽  
...  
Keyword(s):  
Self Assembly ◽  
Building Blocks ◽  
The Self

scholarly journals Time, perspective and semantic representation

2017 ◽  
Vol 10 (1) ◽  
pp. 26-55 ◽  
Author(s):  
K. M. JASZCZOLT
Keyword(s):  
Time Perspective ◽  
Semantic Representation ◽  
Building Blocks ◽  
The Self ◽  
Epistemic Modality ◽  
Conceptual Approach ◽  
Temporal Asymmetry ◽  
Temporal Reference ◽  
Semantic Building Blocks ◽  
Cognitive Plausibility

abstractI discuss the perspectival nature of temporality in discourse and argue that the human concept of time can no more be dissociated from the perspectival thought than the concept of the self can. The corollary of this observation is that perspectival temporality can no more be excluded from the semantic representation than the notion of the self can: neither can be reduced to the bare referent for the purpose of semantic representation if the latter is to retain cognitive plausibility. I present such a semantic qua conceptual approach to temporal reference developed within my theory of Default Semantics. I build upon my theory of time as epistemic modality according to which, on the level of conceptual qua semantic building blocks, temporality reduces to degrees of detachment from the certainty of the here and the now. I also address the questions of temporal asymmetry between the past and the future, and the relation between metaphysical time (timeM), psychological time (timeE, where ‘E’ marks the domain of epistemological enquiry), and time in natural language (timeL), concluding that the perspective-infused timeE and timeL are compatible with timeM of mathematical models of spacetime: all are definable through possibility and perspectivity.

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