scholarly journals Self-Propelled Motion Sensitive to the Chemical Structure of Amphiphilic Molecular Layer on an Aqueous Phase

Membranes ◽  
2021 ◽  
Vol 11 (11) ◽  
pp. 885
Author(s):  
Muneyuki Matsuo ◽  
Hiromi Hashishita ◽  
Satoshi Nakata
Keyword(s):  
Stearic Acid ◽  
Aqueous Phase ◽  
Chemical Structure ◽  
Molecular Level ◽  
Molecular Layer ◽  
Molecular Structures ◽  
The Self ◽  
Contributing Factors ◽  
Molecular Layers ◽  
Tof Ms

Two novel amphiphiles, N-(3-nitrophenyl)stearamide (MANA) and N,N′-(4-nitro-1,3-phenylene)distearamide (OPANA), were synthesized by reacting nitroanilines with one or two equivalents of stearic acid. We investigated how the molecular structures of these compounds influenced the characteristics of a self-propelled camphor disk placed on a monolayer of the synthesized amphiphiles. Three types of motion were observed at different surface pressures (Π): continuous motion (Π < 4 mN m−1), deceleration (4 mN ≤ Π ≤ 20 mN m−1), and no motion (Π > 20 mN m−1). The speed of the motion of the camphor disks was inversely related to Π for both MANA and OPANA at the temperatures tested, when Π increased in the respective molecular layers under compression. The spectroscopic evidence from UV-Vis, NMR, and ESI-TOF-MS revealed that the dependence of the speed of the motion on Π originates from the intermolecular interactions that are present in the monolayers. This study suggests that it is possible to control the self-propelled motion by manipulating contributing factors at the molecular level.

A Solvent-Dependent and Electrochemically Controlled Self-Assembling/Disassembling System

2003 ◽  
Vol 68 (9) ◽  
pp. 1647-1662 ◽  
Author(s):  
Valeria Amendola ◽  
Massimo Boiocchi ◽  
Yuri Diaz Fernandez ◽  
Carlo Mangano ◽  
Piersandro Pallavicini
Keyword(s):  
Equilibrium Mixture ◽  
Bidentate Ligand ◽  
Molecular Structures ◽  
The Self ◽  
Molar Ratio ◽  
Crystal And Molecular Structures ◽  
Self Assembling ◽  
Irreversible Oxidation ◽  
Irreversible Reduction ◽  
Metal Ligand

The bis-bidentate ligand R,S-1,2-diphenyl-N,N'-bis(2-quinolinemethylidene)ethane-1,2-diamine (ligand 4), containing two (iminomethyl)quinoline moieties separated by a cis-1,2-diphenylethylene spacer, forms stable complexes with both CuI and CuII. With CuII, the monomeric 1:1 complex [CuII(4)]2+ is obtained both in CH3CN and CH2Cl2. With CuI and overall 1:1 metal/ligand molar ratio, an equilibrium mixture is obtained in CH3CN, consisting of [CuI(4)2]+, [CuI2(4)2]2+ and [CuI2(4)(CH3CN)4]2+. The preponderant species is the two-metal one-ligand "open" complex [CuI2(4)(CH3CN)4]2+, in which each Cu+ cation is coordinated in a tetrahedral fashion by one (iminomethyl)quinoline unit and by two CH3CN molecules. Precipitation from the equilibrium mixture yields only crystals of [CuI2(4)(CH3CN)4](ClO4)2·2CH3CN, whose crystal and molecular structures have been determined. On the other hand, in the poorly coordinating CH2Cl2 solvent, only the dimeric helical [CuI2(4)2]2+ complex is obtained, when the overall metal/ligand 1:1 molar ratio is chosen. Addition of large quantities of acetonitrile to solutions of [CuI2(4)2]2+ in dichlorometane results in the formation of [CuI2(4)(CH3CN)4]2+, i.e. in the solvent-driven disassembling of the CuI helicate. While electrochemistry in CH3CN is poorly defined due to the presence of more than one CuI species, cyclic voltammetry experiments carried out in CH2Cl2 revealed a well defined behavior, with irreversible oxidation of [CuI2(4)2]2+ and irreversible reduction of [CuII(4)]2+ taking place at separate potentials (∆E ≈ 700 mV). Irreversibility and separation of the redox events are due to the self-assembling and disassembling processes following the reduction and oxidation, respectively.

scholarly journals Pterygium—The Good, the Bad, and the Ugly

Cells ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1567
Author(s):  
Sara I. Van Acker ◽  
Bert Van den Bogerd ◽  
Michel Haagdorens ◽  
Vasiliki Siozopoulou ◽  
Sorcha Ní Dhubhghaill ◽  
...  
Keyword(s):  
Dna Damage ◽  
Molecular Level ◽  
The Self ◽  
Grading System ◽  
Ocular Surface Squamous Neoplasia ◽  
True Nature ◽  
Intervention Point ◽  
Pathological Evaluation ◽  
Repair Mechanisms ◽  
Life Threatening

Pterygium is a multifaceted pathology that displays apparent conflicting characteristics: benign (e.g., self-limiting and superficial), bad (e.g., proliferative and potentially recurrent) and ugly (e.g., signs of preneoplastic transformation). The natural successive question is: why are we lacking reports showing that pterygium lesions become life-threatening through metastasis, especially since pterygium has considerable similarities with UV-related malignancies on the molecular level? In this review, we consider how our pathophysiological understanding of the benign pterygium pathology overlaps with ocular surface squamous neoplasia and skin cancer. The three UV-related disorders share the same initial insult (i.e., UV radiation) and responsive repair mechanisms to the ensuing (in)direct DNA damage. Their downstream apoptotic regulators and other cellular adaptations are remarkably alike. However, a complicating factor in understanding the fine line between the self-limiting nature of pterygium and the malignant transformation in other UV-related diseases is the prominent ambiguity in the pathological evaluation of pterygium biopsies. Features of preneoplastic transformation (i.e., dysplasia) are used to define normal cellular reactions (i.e., atypia and metaplasia) and vice versa. A uniform grading system could help in unraveling the true nature of this ancient disease and potentially help in identifying the earliest intervention point possible regarding the cellular switch that drives a cell’s fate towards cancer.

Kinetic theory of protein filament growth: Self-consistent methods and perturbative techniques

2014 ◽  
Vol 29 (02) ◽  
pp. 1530002 ◽  
Author(s):  
Thomas C. T. Michaels ◽  
Tuomas P. J. Knowles
Keyword(s):  
Self Assembly ◽  
Protein Structures ◽  
Filamentous Growth ◽  
Molecular Structures ◽  
The Self ◽  
Rate Equations ◽  
Disease States ◽  
Self Consistent ◽  
Monomeric Proteins ◽  
General Physical

Filamentous protein structures are of high relevance for the normal functioning of the cell, where they provide the structural component for the cytoskeleton, but are also implicated in the pathogenesis of many disease states. The self-assembly of these supra-molecular structures from monomeric proteins has been studied extensively in the past 50 years and much interest has focused on elucidating the microscopic events that drive linear growth phenomena in a biological setting. Master equations have proven to be particularly fruitful in this context, allowing specific assembly mechanisms to be linked directly to experimental observations of filamentous growth. Recently, these approaches have increasingly been applied to aberrant protein polymerization, elucidating potential implications for controlling or combating the formation of pathological filamentous structures. This article reviews recent theoretical advances in the field of filamentous growth phenomena through the use of the master-equation formalism. We use perturbation and self-consistent methods for obtaining analytical solutions to the rate equations describing fibrillar growth and show how the resulting closed-form expressions can be used to shed light on the general physical laws underlying this complex phenomenon. We also present a connection between the underlying ideas of the self-consistent analysis of filamentous growth and the perturbative renormalization group.

scholarly journals The Vehicle Determines the Destination: The Significance of Seminal Plasma Factors for Male Fertility

2020 ◽  
Vol 21 (22) ◽  
pp. 8499
Author(s):  
Fengli Wang ◽  
Weina Yang ◽  
Sijin Ouyang ◽  
Shuiqiao Yuan
Keyword(s):  
Seminal Plasma ◽  
Male Fertility ◽  
Reproductive Tract ◽  
Biological Fluid ◽  
Female Reproductive Tract ◽  
Molecular Structures ◽  
Contributing Factors ◽  
Non Invasive ◽  
Long Time ◽  
Plasma Factors

Of all human infertility cases, up to 50% show contributing factors leading to defects in the male reproductive physiology. Seminal plasma (SP) is the biological fluid derived from the male accessory sex gland which carries spermatozoa passing throughout the male and female reproductive tract during ejaculation. It contains a complicated set of heterogeneous molecular structures, including proteins, cell-free nucleic acid (DNA, microRNA and LncRNA), and small-molecule metabolites as well as inorganic chemicals (ions). For a long time, the substantial significance of seminal plasma factors’ functions has been underestimated, which is restricted to spermatozoa transport and protection. Notably, significant advancements have been made in dissecting seminal plasma components, revealing new insights into multiple aspects of sperm function, as well as fertilization and pregnancy outcomes in recent years. In this review, we summarize the state-of-art discoveries regarding SP compositions and their implications in male fertility, particularly describing the novel understanding of seminal plasma components and related modifications using “omics” approaches and mainly focusing on proteome and RNA-seq data in the latest decade. Meanwhile, we highlighted the proposed mechanism of the regulation of SP molecules on immunomodulation in the female reproductive tract. Moreover, we also discussed the proteins investigated as non-invasive diagnosis biomarkers for male infertility in the clinic.

scholarly journals Lissencephaly-pachygyria and cerebellar hypoplasia in a calf

2016 ◽  
Vol 46 (9) ◽  
pp. 1622-1628
Author(s):  
Bianca Lemos dos Santos ◽  
Maria Cecília Florisbal Damé ◽  
Ana Carolina Barreto Coelho ◽  
Plínio Aguiar Oliveira ◽  
Clairton Marcolongo-Pereira ◽  
...  
Keyword(s):  
Gray Matter ◽  
Molecular Layer ◽  
Clinical Signs ◽  
Sporadic Case ◽  
Cerebellar Hypoplasia ◽  
Congenital Diseases ◽  
Central Nervous Systems ◽  
Thoracic And Abdominal ◽  
Molecular Layers ◽  
The Brain

ABSTRACT: A case of lissencephaly-pachygyria and cerebellar hypoplasia diagnosed in a Charolais x Tabapuã calf is described. The calf presented since birth, clinical signs characterized by apathy, prolonged recumbency, tremors of the head and neck, ataxia, hypermetria, difficulty walking, blindness and swelling of the joints of the four limbs. Due to the unfavorable prognosis, the animal was euthanized and necropsied at 34 days of age. At necropsy, a rudimentary development of the brain folds (gyri) and grooves (sulci) was observed, and the cerebellum was hypoplastic. The cut surface of the brain exhibited thickening of the gray matter (pachygyria) in the frontal, parietal, temporal and occipital cortices and narrowing of the white matter. In the organs of the thoracic and abdominal cavities, no significant lesions were observed. Histologically, cerebral cortex was thick and exhibited neuronal disorganization of the gray matter. The cerebellum had a thin molecular layer, and neuronal disorganization with ectopia of the Purkinje neurons in the region of the granular and molecular layers. There were no bacterial growths in cultures of joint swabs. This was the only case on the property, which suggests that this malformation, which has not previously been described in cattle, was a sporadic case, and it was not possible to determine its cause. Neurological lesions and clinical sings presented here should be considered in the differential diagnosis of congenital diseases of the central nervous systems of cattle.

MALDI-TOF MS Reveals the Molecular Level Structures of Different Hydrophilic−Hydrophobic Polyether-esters†

2009 ◽  
Vol 10 (6) ◽  
pp. 1540-1546 ◽  
Author(s):  
Grazyna Adamus ◽  
Minna Hakkarainen ◽  
Anders Höglund ◽  
Marek Kowalczuk ◽  
Ann-Christine Albertsson
Keyword(s):  
Molecular Level ◽  
Maldi Tof Ms ◽  
Maldi Tof ◽  
Tof Ms

Silica Surface Modification Reactions with Aluminum and Boron Alkyls and (Alkyl)Chlorides: Reactivities and Surface Nanostructures

2008 ◽  
Vol 8 (2) ◽  
pp. 660-666 ◽  
Author(s):  
Jonathan P. Blitz ◽  
Jeannine M. Christensen ◽  
Carol A. Deakyne ◽  
Vladimir M. Gun'ko
Keyword(s):  
Chemical Structure ◽  
Silica Surface ◽  
Molecular Level ◽  
Ring Structure ◽  
Membered Ring ◽  
Silica Surfaces ◽  
Surface Nanostructures ◽  
Reactive Groups ◽  
Aluminum Compounds ◽  
Silica Surface Modification

The functionalization of nanoporous and nanoparticulate silica surfaces requires a molecular level understanding of the chemistry and structures which result from surface reactions. Various types of reactive groups on silica can participate, giving rise to different nanostructures. It is necessary to devise methods to alter the reactive nature of silica surfaces to control the nanoscale chemical structure. Various silica pretreatments are utilized to alter the silica surface prior to reaction with AlEt3, AlEtxCl3−x, BEt3, BCl3, and TiCl4. Reactivities of these surface reactive reagents are compared. Aluminum compounds preferentially react with loss of alkane rather than HCl, in a thermodynamically controlled reaction as determined by ab initio computational methods. Consideration of the structures resulting from reaction of the boron and aluminum compounds above with silica surface diols has been taken into account. Particular attention has been paid to the possibility of forming a cyclic 4-membered ring structure. While this is unlikely to form from reactions with MCl3, such structures may be possible when reacting silicas with MMe3.

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