scholarly journals Developments in Treatment Methodologies Using Dendrimers for Infectious Diseases

Molecules ◽  
2021 ◽  
Vol 26 (11) ◽  
pp. 3304
Author(s):  
Nina Filipczak ◽  
Satya Siva Kishan Yalamarty ◽  
Xiang Li ◽  
Farzana Parveen ◽  
Vladimir Torchilin
Keyword(s):  
Infectious Diseases ◽  
Antiviral Agents ◽  
Genetic Material ◽  
Three Dimensional ◽  
Specific Group ◽  
Synthetic Vaccines ◽  
Peptide Dendrimers ◽  
Composition And Structure ◽  
Wide Possibility ◽  
Medical Diagnostic

Dendrimers comprise a specific group of macromolecules, which combine structural properties of both single molecules and long expanded polymers. The three-dimensional form of dendrimers and the extensive possibilities for use of additional substrates for their construction creates a multivalent potential and a wide possibility for medical, diagnostic and environmental purposes. Depending on their composition and structure, dendrimers have been of interest in many fields of science, ranging from chemistry, biotechnology to biochemical applications. These compounds have found wide application from the production of catalysts for their use as antibacterial, antifungal and antiviral agents. Of particular interest are peptide dendrimers as a medium for transport of therapeutic substances: synthetic vaccines against parasites, bacteria and viruses, contrast agents used in MRI, antibodies and genetic material. This review focuses on the description of the current classes of dendrimers, the methodology for their synthesis and briefly drawbacks of their properties and their use as potential therapies against infectious diseases.

Crystal Structure Analysis of Cu-Zr Alloys by Convergent Beam Diffraction

1981 ◽  
Vol 39 ◽  
pp. 354-355
Author(s):  
A. F. Marshall ◽  
J. W. Steeds ◽  
D. Bouchet ◽  
S. L. Shinde ◽  
R. G. Walmsley
Keyword(s):  
Crystal Structure ◽  
Point Group ◽  
Intermetallic Phase ◽  
Three Dimensional ◽  
Crystal Structure Analysis ◽  
Ion Milling ◽  
Composition And Structure ◽  
Unit Cells ◽  
Sputter Deposited ◽  
Convergent Beam

Convergent beam electron diffraction is a powerful technique for determining the crystal structure of a material in TEM. In this paper we have applied it to the study of the intermetallic phases in the Cu-rich end of the Cu-Zr system. These phases are highly ordered. Their composition and structure has been previously studied by microprobe and x-ray diffraction with sometimes conflicting results.The crystalline phases were obtained by annealing amorphous sputter-deposited Cu-Zr. Specimens were thinned for TEM by ion milling and observed in a Philips EM 400. Due to the large unit cells involved, a small convergence angle of diffraction was used; however, the three-dimensional lattice and symmetry information of convergent beam microdiffraction patterns is still present. The results are as follows:1) 21 at% Zr in Cu: annealed at 500°C for 5 hours. An intermetallic phase, Cu3.6Zr (21.7% Zr), space group P6/m has been proposed near this composition (2). The major phase of our annealed material was hexagonal with a point group determined as 6/m.

Electrophoresis-Microwave Synthesis of S, N-Doped Graphene Foam for High-Performance Supercapacitors

2021 ◽  
Author(s):  
Wenqiang Wang ◽  
Wenyi Zhang ◽  
Gengchao Wang ◽  
Chunzhong Li
Keyword(s):  
Electrode Material ◽  
Microwave Synthesis ◽  
High Performance ◽  
Three Dimensional ◽  
Graphene Foam ◽  
Composition And Structure ◽  
Doped Graphene ◽  
The Ideal

The three-dimensional self-standing architecture of heteroatom-doped graphene is the ideal electrode material for supercapacitors. However, the facile control of its composition and structure is still a challenge. Herein we have...

scholarly journals Amino Acid Substitutions Associated with Treatment Failure for Hepatitis C Virus Infection

2020 ◽  
Vol 58 (12) ◽  
Author(s):  
María Eugenia Soria ◽  
Carlos García-Crespo ◽  
Brenda Martínez-González ◽  
Lucía Vázquez-Sirvent ◽  
Rebeca Lobo-Vega ◽  
...  
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Amino Acid ◽  
Treatment Failure ◽  
Antiviral Agents ◽  
Three Dimensional ◽  
Sustained Viral Response ◽  
Amino Acid Substitutions ◽  
Hepatitis C Virus Infection ◽  
Bona Fide

ABSTRACT Despite the high virological response rates achieved with current directly acting antiviral agents (DAAs) against hepatitis C virus (HCV), around 2% to 5% of treated patients do not achieve a sustained viral response. The identification of amino acid substitutions associated with treatment failure requires analytical designs, such as subtype-specific ultradeep sequencing (UDS) methods, for HCV characterization and patient management. Using this procedure, we have identified six highly represented amino acid substitutions (HRSs) in NS5A and NS5B of HCV, which are not bona fide resistance-associated substitutions (RAS), from 220 patients who failed therapy. They were present frequently in basal and posttreatment virus of patients who failed different DAA-based therapies. Contrary to several RAS, HRSs belong to the acceptable subset of substitutions according to the PAM250 replacement matrix. Their mutant frequency, measured by the number of deep sequencing reads within the HCV quasispecies that encode the relevant substitutions, ranged between 90% and 100% in most cases. They also have limited predicted disruptive effects on the three-dimensional structures of the proteins harboring them. Possible mechanisms of HRS origin and dominance, as well as their potential predictive value for treatment response, are discussed.

scholarly journals Application of Dendrimers for the Treatment of Infectious Diseases

Molecules ◽  
2018 ◽  
Vol 23 (9) ◽  
pp. 2205 ◽  
Author(s):  
Zandile Mhlwatika ◽  
Blessing Aderibigbe
Keyword(s):  
Drug Delivery ◽  
Drug Resistance ◽  
Infectious Diseases ◽  
Water Solubility ◽  
Three Dimensional ◽  
Parasitic Infections ◽  
Release Mechanism ◽  
Macromolecular Network ◽  
And Control ◽  
Drug Encapsulation Efficiency

Dendrimers are drug delivery systems that are characterized by a three-dimensional, star-shaped, branched macromolecular network. They possess ideal properties such as low polydispersity index, biocompatibility and good water solubility. They are made up of the interior and the exterior layers. The exterior layer consists of functional groups that are useful for conjugation of drugs and targeting moieties. The interior layer exhibits improved drug encapsulation efficiency, reduced drug toxicity, and controlled release mechanisms. These unique properties make them useful for drug delivery. Dendrimers have attracted considerable attention as drug delivery system for the treatment of infectious diseases. The treatment of infectious diseases is hampered severely by drug resistance. Several properties of dendrimers such as their ability to overcome drug resistance, toxicity and control the release mechanism of the encapsulated drugs make them ideal systems for the treatment of infectious disease. The aim of this review is to discuss the potentials of dendrimers for the treatment of viral and parasitic infections.

scholarly journals Vertical circulation and thermospheric composition: a modelling study

1999 ◽  
Vol 17 (6) ◽  
pp. 794-805 ◽  
Author(s):  
H. Rishbeth ◽  
I. C. F. Müller-Wodarg
Keyword(s):  
Concentration Ratio ◽  
Atomic Oxygen ◽  
Molecular Nitrogen ◽  
Three Dimensional ◽  
Atmospheric Composition ◽  
Vertical Circulation ◽  
Energy Inputs ◽  
Composition And Structure ◽  
Vertical Distributions ◽  
Summer Hemisphere

Abstract. The coupled thermosphere-ionosphere-plasmasphere model CTIP is used to study the global three-dimensional circulation and its effect on neutral composition in the midlatitude F-layer. At equinox, the vertical air motion is basically up by day, down by night, and the atomic oxygen/molecular nitrogen [O/N2] concentration ratio is symmetrical about the equator. At solstice there is a summer-to-winter flow of air, with downwelling at subauroral latitudes in winter that produces regions of large [O/N2] ratio. Because the thermospheric circulation is influenced by the high-latitude energy inputs, which are related to the geometry of the Earth's magnetic field, the latitude of the downwelling regions varies with longitude. The downwelling regions give rise to large F2-layer electron densities when they are sunlit, but not when they are in darkness, with implications for the distribution of seasonal and semiannual variations of the F2-layer. It is also found that the vertical distributions of O and N2 may depart appreciably from diffusive equilibrium at heights up to about 160 km, especially in the summer hemisphere where there is strong upwelling. Atmospheric composition and structure (thermosphere · composition and chemistry) · Ionosphere (ionosphere · atmosphere interactions)

Synthesis of Layered Titanate Micro/nano-materials for Efficient Pollutant Treatment in Aqueous Media

2011 ◽  
Vol 1309 ◽  
Author(s):  
Y. X. Tang ◽  
Y. K. Lai ◽  
D. G. Gong ◽  
Zhili Dong ◽  
Z. Chen
Keyword(s):  
Aqueous Media ◽  
Three Dimensional ◽  
High Specific Surface Area ◽  
Nano Materials ◽  
Raman Scattering Spectroscopy ◽  
Micro Particles ◽  
Transmission Electron ◽  
Composition And Structure ◽  
Layered Titanate ◽  
The One

ABSTRACTIn this work, the one dimensional (1D) titanate nanotubes (TNT)/nanowires (TNW), bulk titanate micro-particles (TMP), and three dimensional (3D) titanate microsphere particles (TMS) with high specific surface area were synthesized via different approaches. The chemical composition and structure of these products have been characterized by field emission scanning electron microscopy (FESEM), transmission electron microscope (TEM) study and Raman scattering spectroscopy. The as-prepared TMS shows excellent adsorption performance compared with TMP, TNW and TNT when methylene blue (MB) and PbII ions are used as representative organic and inorganic pollutants.

The first uranyl complexes with valerate ions

2013 ◽  
Vol 69 (7) ◽  
pp. 721-726 ◽  
Author(s):  
Anton V. Savchenkov ◽  
Anna V. Vologzhanina ◽  
Larisa B. Serezhkina ◽  
Denis V. Pushkin ◽  
Viktor N. Serezhkin
Keyword(s):  
Three Dimensional ◽  
Uranyl Complexes ◽  
X Ray ◽  
Alkyl Groups ◽  
Neutral Compound ◽  
Homologous Compounds ◽  
Composition And Structure ◽  
Ft Ir ◽  
A Site ◽  
Ir Spectroscopic

FT–IR spectroscopy and single-crystal X-ray structure analysis were used to characterize the discrete neutral compound diaquadioxidobis(n-valerato-κ2O,O′)uranium(VI), [UO2(C4H9COO)2(H2O)2], (I), and the ionic compound potassium dioxidotris(n-valerato-κ2O,O′)uranium(VI), K[UO2(C4H9COO)3], (II). The UVIcation in neutral (I) is at a site of 2/msymmetry. Potassium salt (II) has two U centres and two K+cations residing on twofold axes, while a third independent formula unit is on a general position. The ligands in both compounds were found to suffer severe disorder. The FT–IR spectroscopic results agree with the X-ray data. The composition and structure of the ionic potassium uranyl valerate are similar to those of previously reported potassium uranyl complexes with acetate, propionate and butyrate ligands. Progressive lengthening of the alkyl groups in these otherwise similar compounds was found to have an impact on their structures, including on the number of independent U and K+sites, on the coordination modes of some of the K+centres and on the minimum distances between U atoms. The evolution of the KUO6frameworks in the four homologous compounds is analysed in detail, revealing a new example of three-dimensional topological isomerism in coordination compounds of UVI.

scholarly journals The biological applications of DNA nanomaterials: current challenges and future directions

2021 ◽  
Vol 6 (1) ◽  
Author(s):  
Wenjuan Ma ◽  
Yuxi Zhan ◽  
Yuxin Zhang ◽  
Chenchen Mao ◽  
Xueping Xie ◽  
...  
Keyword(s):  
Self Assembly ◽  
Drug Carrier ◽  
Genetic Material ◽  
Three Dimensional ◽  
Real Life ◽  
Dna Nanotechnology ◽  
Structural Development ◽  
Biological Applications ◽  
Dna Materials ◽  
Functional Dna

AbstractDNA, a genetic material, has been employed in different scientific directions for various biological applications as driven by DNA nanotechnology in the past decades, including tissue regeneration, disease prevention, inflammation inhibition, bioimaging, biosensing, diagnosis, antitumor drug delivery, and therapeutics. With the rapid progress in DNA nanotechnology, multitudinous DNA nanomaterials have been designed with different shape and size based on the classic Watson–Crick base-pairing for molecular self-assembly. Some DNA materials could functionally change cell biological behaviors, such as cell migration, cell proliferation, cell differentiation, autophagy, and anti-inflammatory effects. Some single-stranded DNAs (ssDNAs) or RNAs with secondary structures via self-pairing, named aptamer, possess the ability of targeting, which are selected by systematic evolution of ligands by exponential enrichment (SELEX) and applied for tumor targeted diagnosis and treatment. Some DNA nanomaterials with three-dimensional (3D) nanostructures and stable structures are investigated as drug carrier systems to delivery multiple antitumor medicine or gene therapeutic agents. While the functional DNA nanostructures have promoted the development of the DNA nanotechnology with innovative designs and preparation strategies, and also proved with great potential in the biological and medical use, there is still a long way to go for the eventual application of DNA materials in real life. Here in this review, we conducted a comprehensive survey of the structural development history of various DNA nanomaterials, introduced the principles of different DNA nanomaterials, summarized their biological applications in different fields, and discussed the current challenges and further directions that could help to achieve their applications in the future.

Creating a tissue-specific microdispersed matrix from a decellularized porcine liver

2020 ◽  
Vol 4 ◽  
pp. 41-50
Author(s):  
A.D. Kirillova ◽  
◽  
Yu.B. Basok ◽  
A.E. Lazhko ◽  
A. M. Grigoryev ◽  
...  
Keyword(s):  
Sodium Dodecyl ◽  
Genetic Material ◽  
Three Dimensional ◽  
Dimensional Structure ◽  
Porcine Liver ◽  
Tissue Specific ◽  
Main Components ◽  
Triton X ◽  
Injectable Form

The main problem with decellularization of liver tissue as a tissue-specific matrix/scaffold in liver bioengineered structures is the need to maximize the preservation of the original three-dimensional structure of the tissue and the main components of its extracellular matrix (ECM) while removing cells and genetic material. The attempts to use the existing protocols for the decellularization of other tissues and organs have been unsuccessful. The aim of the work is to develop a method for creation of tissue-specific microdispersed matrix from decellularized porcine liver (TMM DLp). The protocol for decellularization of porcine liver (Lp) fragments has been developed based on the complex application of chemical (sodium dodecyl sulfate and Triton X-100), biochemical (DNase I), and physical (supercritical CO2) methods for treatment the initial tissue. As a result of the found optimal conditions for decellularization of Lp with subsequent cryomicronization of DLp, the injectable form of the microdispersed tissue-specific matrix was obtained, which represents DLp microparticles with the size of 100-200 microns with the residual amount of DNA no more than 10±1.5 ng/mg (less than 1.0%), with the preservation of the microstructure and basic composition of the liver ECM. According to the assessment of biocompatible properties in vitro, TMM DLp samples meet the criteria of biological safety for cytotoxicity and hemolytic activity.

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