ON RINGS OVER WHICH THE INJECTIVE HULL OF EACH CYCLIC MODULE IS Σ-EXTENDING

2012 ◽  
Vol 12 (01) ◽  
pp. 1250127 ◽  
Author(s):  
SARAPEE CHAIRAT ◽  
DINH VAN HUYNH ◽  
CHITLADA SOMSUP
Keyword(s):  
Injective Hull ◽  
Cyclic Module ◽  
Interesting Class

Carl Faith (2003) introduced and investigated an interesting class of rings over which every cyclic right module has Σ-injective injective hull (abbr., right CSI-rings). Inspired by this we investigate rings over which every cyclic right R-module has a Σ-extending injective hull. We call such rings right CSE-rings and show that the class of right CSE-rings and that of right CSI-rings coincide. We also use other hulls of cyclic modules to define other classes of rings, and investigate their structure. We prove, among others, that a ring R is right QI if and only if the quasi-injective hull of each cyclic right module is Σ-injective.

Inorganic Gold and Polymeric Poly(Lactide-co-glycolide) Nanoparticles as Novel Strategies to Ameliorate the Biological Properties of Antimicrobial Peptides

2020 ◽  
Vol 21 (4) ◽  
pp. 429-438 ◽  
Author(s):  
Bruno Casciaro ◽  
Francesca Ghirga ◽  
Deborah Quaglio ◽  
Maria Luisa Mangoni
Keyword(s):  
Antimicrobial Peptides ◽  
Biological Properties ◽  
Biological Profile ◽  
Innovative Strategy ◽  
Different Types ◽  
New Antibiotics ◽  
Interesting Class ◽  
Alternative Antimicrobials ◽  
Nanoparticulate Systems ◽  
Infective Activity

Cationic antimicrobial peptides (AMPs) are an interesting class of gene-encoded molecules endowed with a broad-spectrum of anti-infective activity and immunomodulatory properties. They represent promising candidates for the development of new antibiotics, mainly due to their membraneperturbing mechanism of action that very rarely induces microbial resistance. However, bringing AMPs into the clinical field is hampered by some intrinsic limitations, encompassing low peptide bioavailability at the target site and high peptide susceptibility to proteolytic degradation. In this regard, nanotechnologies represent an innovative strategy to circumvent these issues. According to the literature, a large variety of nanoparticulate systems have been employed for drug-delivery, bioimaging, biosensors or nanoantibiotics. The possibility of conjugating different types of molecules, including AMPs, to these systems, allows the production of nanoformulations able to enhance the biological profile of the compound while reducing its cytotoxicity and prolonging its residence time. In this minireview, inorganic gold nanoparticles (NPs) and biodegradable polymeric NPs made of poly(lactide-coglycolide) are described with particular emphasis on examples of the conjugation of AMPs to them, to highlight the great potential of such nanoformulations as alternative antimicrobials.

Oxa-Michael polyaddition of vinylsulfonylethanol for aliphatic polyethersulfones

2021 ◽  
Author(s):  
Nicole Ziegenbalg ◽  
Ruth Lohwasser ◽  
Giovanni D’Andola ◽  
Torben Adermann ◽  
Johannes Christopher Brendel
Keyword(s):  
Refractive Index ◽  
High Temperature ◽  
Flame Retardant ◽  
Chemical Resistance ◽  
High Refractive Index ◽  
Industrial Applications ◽  
Interesting Class ◽  
The Common ◽  
Flame Retardant Properties

Polyethersulfones are an interesting class of polymers for industrial applications due to their unusual properties such as a high refractive index, flame-retardant properties, high temperature and chemical resistance. The common...

scholarly journals Interactions between an Associative Amphiphilic Block Polyelectrolyte and Surfactants in Water: Effect of Charge Type on Solution Properties and Aggregation

Polymers ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 1729
Author(s):  
Patrizio Raffa
Keyword(s):  
Surface Tension ◽  
Self Assembly ◽  
Interaction Model ◽  
Industrial Applications ◽  
Molecular Organization ◽  
Different Types ◽  
Solution Rheology ◽  
Interesting Class ◽  
First Time

The study of interactions between polyelectrolytes (PE) and surfactants is of great interest for both fundamental and applied research. These mixtures can represent, for example, models of self-assembly and molecular organization in biological systems, but they are also relevant in industrial applications. Amphiphilic block polyelectrolytes represent an interesting class of PE, but their interactions with surfactants have not been extensively explored so far, most studies being restricted to non-associating PE. In this work, interactions between an anionic amphiphilic triblock polyelectrolyte and different types of surfactants bearing respectively negative, positive and no charge, are investigated via surface tension and solution rheology measurements for the first time. It is evidenced that the surfactants have different effects on viscosity and surface tension, depending on their charge type. Micellization of the surfactant is affected by the presence of the polymer in all cases; shear viscosity of polymer solutions decreases in presence of the same charge or nonionic surfactants, while the opposite charge surfactant causes precipitation. This study highlights the importance of the charge type, and the role of the associating hydrophobic block in the PE structure, on the solution behavior of the mixtures. Moreover, a possible interaction model is proposed, based on the obtained data.

scholarly journals Discovery of a Novel Styrene Monooxygenase Originating from the Metagenome

2007 ◽  
Vol 73 (18) ◽  
pp. 5832-5839 ◽  
Author(s):  
Erik W. van Hellemond ◽  
Dick B. Janssen ◽  
Marco W. Fraaije
Keyword(s):  
Styrene Oxide ◽  
Enantiomeric Excess ◽  
Metagenomic Library ◽  
Blue Pigment ◽  
Sequence Identity ◽  
Small Family ◽  
Genome Sequence Database ◽  
Loam Soil ◽  
Interesting Class ◽  
Styrene Derivatives

ABSTRACT Oxygenases form an interesting class of biocatalysts, as they typically perform oxygenations with exquisite chemo-, regio-, and/or enantioselectivity. It has been observed that, once heterologously expressed in Escherichia coli, some oxygenases are able to form the blue pigment indigo. We have exploited this characteristic to screen a metagenomic library derived from loam soil and identified a novel oxygenase. This oxygenase shows 50% sequence identity with styrene monooxygenases from pseudomonads (StyA). Only a limited number of homologs can be found in the genome sequence database, indicating that this biocatalyst is a member of a relatively small family of bacterial monooxygenases. The newly identified monooxygenase catalyzes the epoxidation of styrene and styrene derivatives and forms the corresponding (S)-epoxides with excellent enantiomeric excess [e.g., (S)-styrene oxide is formed with >99% enantiomeric excess, ee] and therefore is named styrene monooxgenase subunit A (SmoA). SmoA shows high enantioselectivity towards aromatic sulfides [e.g., (R)-ethyl phenyl sulfoxide is formed with 92% ee]. This excellent enantioselectivity in combination with the moderate sequence identity forms a clear indication that SmoA from a metagenomic origin represents a new enzyme within the small family of styrene monooxygenases.

A New Construction of the Injective Hull

1968 ◽  
Vol 11 (1) ◽  
pp. 19-21 ◽  
Author(s):  
Isidore Fleischer
Keyword(s):  
Essential Extension ◽  
Injective Hull ◽  
Minimal Cardinality ◽  
New Construction ◽  
Definition Of

The definition of injectivity, and the proof that every module has an injective extension which is a subextension of every other injective extension, are due to R. Baer [B]. An independent proof using the notion of essential extension was given by Eckmann-Schopf [ES]. Both proofs require the p reliminary construction of some injective overmodule. In [F] I showed how the latter proof could be freed from this requirement by exhibiting a set F in which every essential extension could be embedded. Subsequently J. M. Maranda pointed out that F has minimal cardinality. It follows that F is equipotent with the injective hull. Below Icon struct the injective hull by equipping Fit self with a module strucure.

An Interesting Class of Monotonic Functions

1909 ◽  
Vol 16 (1) ◽  
pp. 4
Author(s):  
Arthur R. Schweitzer
Keyword(s):  
Monotonic Functions ◽  
Interesting Class

scholarly journals Aromatic Selenocyanates as a New Class of Non-Mutagenic Antimicrobial Selenium Compounds with Pronounced Activity against Multidrug Resistant ESKAPE Bacteria

2018 ◽  
Author(s):  
Muhammad Jawad Nasim ◽  
Karolina Witek ◽  
Annamaria Kincses ◽  
Muhammad Sarfraz ◽  
Ewa Żesławska ◽  
...  
Keyword(s):  
Cytotoxic Activity ◽  
Multidrug Resistant ◽  
Synthetic Chemistry ◽  
High Biological Activity ◽  
Selenium Compounds ◽  
X Ray Crystallography ◽  
Organic Selenium ◽  
Interesting Class ◽  
Mrsa Strains

Selenocyanates form an interesting class of organic selenium compounds as they serve as multifunctional agents (being the precursors of seleninic acids and diselenides in synthetic chemistry and as antimicrobial and cytotoxic agent in biology) and, due to their similarity with better known thiocyanates promise high biological activity. Yet whilst selenocyanates are common in synthetic chemistry, they are rarely considered in pharmaceutical design. Arylmethyl selenocyanates (1-13) have been synthesized and an insight into their structural properties using X-ray crystallography has been obtained. The compounds subsequently have been evaluated for their potential antimicrobial, nematicidal and cytotoxic activity. ADMET properties in vitro, using mutagenicity (AMES) and permeability (PAMPA) tests, have been determined. The compounds exhibit pronounced activity against various strains of bacteria (both Gram-positive and Gram-negative) and yeasts. Among them, benzylselenocyanate (1) represents the most active anti-ESKAPE agent, with potent antibacterial activity, especially against multidrug resistant MRSA strains (HEMSA 5). Our results demonstrate that the arylmethyl selenocyantes are not only non-mutagenic but also possess moderate cytotoxic activity against cancer cells.

scholarly journals Selection of a Nuclease-Resistant RNA Aptamer Targeting CD19

Cancers ◽  
2021 ◽  
Vol 13 (20) ◽  
pp. 5220
Author(s):  
Carla L. Esposito ◽  
Katrien Van Roosbroeck ◽  
Gianluca Santamaria ◽  
Deborah Rotoli ◽  
Annamaria Sandomenico ◽  
...  
Keyword(s):  
B Cell ◽  
Binding Activity ◽  
Rna Aptamer ◽  
Transmembrane Glycoprotein ◽  
B Cell Malignancy ◽  
A Cell ◽  
Enrichment Protocol ◽  
Interesting Class ◽  
Exponential Enrichment ◽  
Cluster Of Differentiation

The transmembrane glycoprotein cluster of differentiation 19 (CD19) is a B cell–specific surface marker, expressed on the majority of neoplastic B cells, and has recently emerged as a very attractive biomarker and therapeutic target for B-cell malignancies. The development of safe and effective ligands for CD19 has become an important need for the development of targeted conventional and immunotherapies. In this regard, aptamers represent a very interesting class of molecules. Additionally referred to as ‘chemical antibodies’, they show many advantages as therapeutics, including low toxicity and immunogenicity. Here, we isolated a nuclease-resistant RNA aptamer binding to the human CD19 glycoprotein. In order to develop an aptamer also useful as a carrier for secondary reagents, we adopted a cell-based SELEX (Systematic Evolution of Ligands by EXponential Enrichment) protocol adapted to isolate aptamers able to internalise upon binding to their cell surface target. We describe a 2′-fluoro pyrimidine modified aptamer, named B85.T2, which specifically binds to CD19 and shows an exquisite stability in human serum. The aptamer showed an estimated dissociation constant (KD) of 49.9 ± 13 nM on purified human recombinant CD19 (rhCD19) glycoprotein, a good binding activity on human B-cell chronic lymphocytic leukaemia cells expressing CD19, and also an effective and rapid cell internalisation, thus representing a promising molecule for CD19 targeting, as well as for the development of new B-cell malignancy-targeted therapies.

scholarly journals The ideal of Lipschitz classical p-compact operators and its injective hull

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Toufik Tiaiba ◽  
Dahmane Achour
Keyword(s):  
Banach Space ◽  
Compact Operator ◽  
Metric Space ◽  
Metric Spaces ◽  
Compact Operators ◽  
Operator Ideal ◽  
Linear Case ◽  
Injective Hull ◽  
Nuclear Operators ◽  
The Ideal

Abstract We introduce and investigate the injective hull of the strongly Lipschitz classical p-compact operator ideal defined between a pointed metric space and a Banach space. As an application we extend some characterizations of the injective hull of the strongly Lipschitz classical p-compact from the linear case to the Lipschitz case. Also, we introduce the ideal of Lipschitz unconditionally quasi p-nuclear operators between pointed metric spaces and show that it coincides with the Lipschitz injective hull of the ideal of Lipschitz classical p-compact operators.

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