scholarly journals Recent Developments of Useful MALDI Matrices for the Mass Spectrometric Characterization of Lipids

Biomolecules ◽  
2018 ◽  
Vol 8 (4) ◽  
pp. 173 ◽  
Author(s):  
Jenny Leopold ◽  
Yulia Popkova ◽  
Kathrin Engel ◽  
Jürgen Schiller
Keyword(s):  
Small Molecules ◽  
Liquid Crystalline ◽  
De Novo ◽  
Organic Matrix ◽  
Laser Wavelength ◽  
Benzoic Acid Derivatives ◽  
The Matrix ◽  
Recent Developments ◽  
Ionization Methods

Matrix-assisted laser desorption/ionization (MALDI) is one of the most successful “soft” ionization methods in the field of mass spectrometry and enables the analysis of a broad range of molecules, including lipids. Although the details of the ionization process are still unknown, the importance of the matrix is commonly accepted. Both, the development of and the search for useful matrices was, and still is, an empirical process, since properties like vacuum stability, high absorption at the laser wavelength, etc. have to be fulfilled by a compound to become a useful matrix. This review provides a survey of successfully used MALDI matrices for the lipid analyses of complex biological samples. The advantages and drawbacks of the established organic matrix molecules (cinnamic or benzoic acid derivatives), liquid crystalline matrices, and mixtures of common matrices will be discussed. Furthermore, we will deal with nanocrystalline matrices, which are most suitable to analyze small molecules, such as free fatty acids. It will be shown that the analysis of mixtures and the quantitative analysis of small molecules can be easily performed if the matrix is carefully selected. Finally, some basic principles of how useful matrix compounds can be “designed” de novo will be introduced.

scholarly journals A multiplexed, automated evolution pipeline enables scalable discovery and characterization of biosensors

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Brent Townshend ◽  
Joy S. Xiang ◽  
Gabriel Manzanarez ◽  
Eric J. Hayden ◽  
Christina D. Smolke
Keyword(s):  
Small Molecules ◽  
Biosynthetic Pathway ◽  
De Novo ◽  
Living Cells ◽  
Regulate Gene Expression ◽  
Liquid Handling ◽  
Regulate Gene

AbstractBiosensors are key components in engineered biological systems, providing a means of measuring and acting upon the large biochemical space in living cells. However, generating small molecule sensing elements and integrating them into in vivo biosensors have been challenging. Here, using aptamer-coupled ribozyme libraries and a ribozyme regeneration method, de novo rapid in vitro evolution of RNA biosensors (DRIVER) enables multiplexed discovery of biosensors. With DRIVER and high-throughput characterization (CleaveSeq) fully automated on liquid-handling systems, we identify and validate biosensors against six small molecules, including five for which no aptamers were previously found. DRIVER-evolved biosensors are applied directly to regulate gene expression in yeast, displaying activation ratios up to 33-fold. DRIVER biosensors are also applied in detecting metabolite production from a multi-enzyme biosynthetic pathway. This work demonstrates DRIVER as a scalable pipeline for engineering de novo biosensors with wide-ranging applications in biomanufacturing, diagnostics, therapeutics, and synthetic biology.

scholarly journals A multiplexed, automated evolution pipeline enables scalable discovery and characterization of biosensors

2020 ◽  
Author(s):  
Brent Townshend ◽  
Joy Xiang ◽  
Gabriel Manzanarez ◽  
Eric Hayden ◽  
Christina Smolke
Keyword(s):  
Small Molecules ◽  
Biosynthetic Pathway ◽  
De Novo ◽  
Living Cells ◽  
Regulate Gene Expression ◽  
Liquid Handling ◽  
Regulate Gene

AbstractBiosensors are key components in engineered biological systems, providing a means of measuring and acting upon the large biochemical space in living cells. However, generating small molecule sensing elements and integrating them into in vivo biosensors have been challenging. Using aptamer-coupled ribozyme libraries and a novel ribozyme regeneration method, we developed de novo rapid in vitro evolution of RNA biosensors (DRIVER) that enables multiplexed discovery of biosensors. With DRIVER and high-throughput characterization (CleaveSeq) fully automated on liquid-handling systems, we identified and validated biosensors against six small molecules, including five for which no aptamers were previously found. DRIVER-evolved biosensors were applied directly to regulate gene expression in yeast, displaying activation ratios up to 33-fold. DRIVER biosensors were also applied in detecting metabolite production from a multi-enzyme biosynthetic pathway. This work demonstrates DRIVER as a scalable pipeline for engineering de novo biosensors with wide-ranging applications in biomanufacturing, diagnostics, therapeutics, and synthetic biology.

scholarly journals Dereplikace látek a de novo charakterizace malých molekul z hmotnostních spekter

2022 ◽  
Vol 116 (1) ◽  
pp. 11-19
Author(s):  
Jiří Novák ◽  
Vladimír Havlíček
Keyword(s):  
Mass Spectrometry ◽  
Small Molecules ◽  
Mass Spectra ◽  
De Novo ◽  
Imaging Mass Spectrometry ◽  
Mass Spectrometry Data ◽  
Data Sets ◽  
Liquid Chromatography Mass Spectrometry ◽  
Imaging Mass Spectrometry Data

We describe the molecular dereplication principles and de novo characterization of small molecules obtained from liquid-chromatography mass spectrometry and imaging mass spectrometry data sets. Our methodology aims at supporting chemists and computer programmers to understand the hidden computing algorithms used for metabolomics mass spectrometry data processing. The approaches have been made available in the open-source tool CycloBranch. The presented tutorial extends the interpretation of mass spectra portfolia described in a series of papers published in Chemicke Listy, issues 2/2020 and 3/2020.

Continuum Modeling for Repetitive Lattice Structures

1988 ◽  
Vol 41 (7) ◽  
pp. 285-296 ◽  
Author(s):  
Ahmed K. Noor
Keyword(s):  
Lattice Structures ◽  
Continuum Modeling ◽  
The Matrix ◽  
The Status ◽  
Analytic Expressions ◽  
Recent Developments ◽  
Definition Of ◽  
Constitutive Matrix ◽  
The Continuum

The status and some recent developments of continuum modeling for repetitive lattice structures are summarized. Discussion focuses on a number of aspects including definition of an effective substitute continuum; characterization of the continuum model; and the different approaches for generating the properties of the continuum, namely, the constitutive matrix, the matrix of mass densities, and the matrix of thermal coefficients. Also, a simple approach is presented for generating the analytic expressions and/or numerical values of the continuum properties. Sample numerical results are presented to demonstrate the effectiveness of the continuum modeling approach. Future directions of research on continuum modeling are identified. These include needed extensions and applications of continuum modeling as well as computational strategies and modeling techniques.

scholarly journals Thermal and Optical Characterization of Polymer-Dispersed Liquid Crystals

2012 ◽  
Vol 2012 ◽  
pp. 1-13 ◽  
Author(s):  
Robert A. Shanks ◽  
Daniel Staszczyk
Keyword(s):  
Liquid Crystals ◽  
Liquid Crystalline ◽  
Scanning Calorimetry ◽  
Uv Curable ◽  
Polymer Dispersed Liquid Crystals ◽  
The Matrix ◽  
Polymer Dispersed ◽  
Acrylate Resin ◽  
Display Order

Liquid crystals are compounds that display order in the liquid state above the melting temperature and below the mesogenic isotropic temperature. Polymer-dispersed liquid crystals (PDLCs) are composite materials in which liquid crystalline material is dispersed within a polymer matrix to form micron-sized droplets. The aim was to prepare several cholesteryl esters or alkoxybenzoic acid PDLCs and characterise thermal and optical properties. Differential scanning calorimetry and polarized optical microscopy were employed. The matrix polymer was a one-component UV-curable epoxy-acrylate resin. PDLCs were formed through entropy controlled phase separation resulting from UV-initiated crosslinking. The liquid crystals, both as mesogenic moieties and as dispersed droplets, exhibited various textures according to their molecular order and orientation. These textures formed in constrained regions separated by phase boundaries that occurred at temperatures characteristic of each liquid crystal used. The PDLC phase transitions occurred at temperatures lower than those exhibited by the mesogenic components in the neat state.

scholarly journals The anticancer natural product ophiobolin A induces cytotoxicity by covalent modification of phosphatidylethanolamine

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Christopher Chidley ◽  
Sunia A Trauger ◽  
Kıvanç Birsoy ◽  
Erin K O'Shea
Keyword(s):  
Small Molecules ◽  
Natural Product ◽  
Mechanism Of Action ◽  
De Novo ◽  
Covalent Modification ◽  
Human Cells ◽  
Head Group ◽  
Loss Of Function ◽  
Drug Leads

Phenotypic screens allow the identification of small molecules with promising anticancer activity, but the difficulty in characterizing the mechanism of action of these compounds in human cells often undermines their value as drug leads. Here, we used a loss-of-function genetic screen in human haploid KBM7 cells to discover the mechanism of action of the anticancer natural product ophiobolin A (OPA). We found that genetic inactivation of de novo synthesis of phosphatidylethanolamine (PE) mitigates OPA cytotoxicity by reducing cellular PE levels. OPA reacts with the ethanolamine head group of PE in human cells to form pyrrole-containing covalent cytotoxic adducts and these adducts lead to lipid bilayer destabilization. Our characterization of this unusual cytotoxicity mechanism, made possible by unbiased genetic screening in human cells, suggests that the selective antitumor activity displayed by OPA may be due to altered membrane PE levels in cancer cells.

Composites - Characterization of Composite Filling Materials: Reactor Response

1988 ◽  
Vol 2 (1) ◽  
pp. 122-133 ◽  
Author(s):  
I.E. Ruyter
Keyword(s):  
Composite Materials ◽  
Review Paper ◽  
Organic Matrix ◽  
Dental Composite ◽  
Clinical Behavior ◽  
Filling Materials ◽  
The Matrix ◽  
Inorganic Fillers ◽  
Ceramic Fillers

Dental composite restorative materials consist of an organic matrix, ceramic fillers, and the interface between the inorganic fillers and the matrix. Marked variations in the composition of the composite materials, as well as different degrees of conversion after polymerization, have been observed. These circumstances lead to substantial differences in the properties of polymerized composite materials. The variations in clinical behavior of the different composite materials, e.g., discoloration or lack of wear resistance, may be explained on the basis of differences in composition. This review paper describes the composition, conversion, and properties of presently available composite materials.

TEM characterization of reaction zone in a SiC fiber-reinforced titanium alloy

1988 ◽  
Vol 46 ◽  
pp. 738-739
Author(s):  
G. Das ◽  
R. E. Omlor
Keyword(s):  
Titanium Alloys ◽  
Reaction Zone ◽  
Carbon Layer ◽  
Fiber Reinforced ◽  
Reaction Products ◽  
Sic Fibers ◽  
Sic Fiber ◽  
The Matrix ◽  
Immense Potential

Fiber reinforced titanium alloys hold immense potential for applications in the aerospace industry. However, chemical reaction between the fibers and the titanium alloys at fabrication temperatures leads to the formation of brittle reaction products which limits their development. In the present study, coated SiC fibers have been used to evaluate the effects of surface coating on the reaction zone in the SiC/IMI829 system.IMI829 (Ti-5.5A1-3.5Sn-3.0Zr-0.3Mo-1Nb-0.3Si), a near alpha alloy, in the form of PREP powder (-35 mesh), was used a茸 the matrix. CVD grown AVCO SCS-6 SiC fibers were used as discontinuous reinforcements. These fibers of 142μm diameter contained an overlayer with high Si/C ratio on top of an amorphous carbon layer, the thickness of the coating being ∽ 1μm. SCS-6 fibers, broken into ∽ 2mm lengths, were mixed with IMI829 powder (representing < 0.1vol%) and the mixture was consolidated by HIP'ing at 871°C/0. 28GPa/4h.

Morphology of High-Performance Rigid-Rod Polymer Fibers and Molecular Composites

1989 ◽  
Vol 47 ◽  
pp. 338-339
Author(s):  
W.W. Adams ◽  
S. J. Krause
Keyword(s):  
Tensile Strength ◽  
High Performance ◽  
Liquid Crystalline ◽  
Molecular Level ◽  
Synergistic Effects ◽  
Tensile Modulus ◽  
Commercial Development ◽  
The Matrix ◽  
Molecular Composites ◽  
Rigid Rod

Rigid-rod polymers such as PBO, poly(paraphenylene benzobisoxazole), Figure 1a, are now in commercial development for use as high-performance fibers and for reinforcement at the molecular level in molecular composites. Spinning of liquid crystalline polyphosphoric acid solutions of PBO, followed by washing, drying, and tension heat treatment produces fibers which have the following properties: density of 1.59 g/cm3; tensile strength of 820 kpsi; tensile modulus of 52 Mpsi; compressive strength of 50 kpsi; they are electrically insulating; they do not absorb moisture; and they are insensitive to radiation, including ultraviolet. Since the chain modulus of PBO is estimated to be 730 GPa, the high stiffness also affords the opportunity to reinforce a flexible coil polymer at the molecular level, in analogy to a chopped fiber reinforced composite. The objectives of the molecular composite concept are to eliminate the thermal expansion coefficient mismatch between the fiber and the matrix, as occurs in conventional composites, to eliminate the interface between the fiber and the matrix, and, hopefully, to obtain synergistic effects from the exceptional stiffness of the rigid-rod molecule. These expectations have been confirmed in the case of blending rigid-rod PBZT, poly(paraphenylene benzobisthiazole), Figure 1b, with stiff-chain ABPBI, poly 2,5(6) benzimidazole, Fig. 1c A film with 30% PBZT/70% ABPBI had tensile strength 190 kpsi and tensile modulus of 13 Mpsi when solution spun from a 3% methane sulfonic acid solution into a film. The modulus, as predicted by rule of mixtures, for a film with this composition and with planar isotropic orientation, should be 16 Mpsi. The experimental value is 80% of the theoretical value indicating that the concept of a molecular composite is valid.

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