jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Alberto Concellón
Source: Angewandte Chemie (article, 2023-09-11)
Field: Materials Science — Electronic, Optical and Magnetic Materials

Liquid Crystal Emulsions: A Versatile Platform for Photonics, Sensing, and Active Matter Abstract The self‐assembly of liquid crystals (LCs) is a fascinating method for controlling the organization of discrete molecules into nanostructured functional materials. Although LCs are traditionally processed in thin films, their confinement within micrometre‐sized droplets has recently revealed new properties and functions, paving the way for next‐generation soft responsive materials. These recent findings have unlocked a wealth of unprecedented applications in photonics (e.g. reflectors, lasing materials), sensing (e.g. biomolecule and pathogen detection), soft robotics (e.g. micropumps, artificial muscles), and beyond. This Minireview focuses on recent developments in LC emulsion designs and highlights a variety of novel potential applications. Perspectives on the opportunities and new directions for implementing LC emulsions in future innovative technologies are also provided. Nanotechnology ; Liquid crystal ; Photonics ; Lasing threshold ; Biomolecule ; Materials science ; Soft matter ; Soft materials ; Variety (cybernetics) ; Microfluidics ; Computer science ; Engineering ; Optoelectronics ; Artificial intelligence Liquid Crystal Research Advancements ; Micro and Nano Robotics
Authors: Hanan O. Farouk | Hager Ebrahim | Heba Sonbol | Monika Malak | Maha Kamal | Noha Ibrahim | Ahmed M. Shawky | Walaa Zarad | Ahmed Emad | Samy Emara
Source: Preprints.org (preprint, 2023-05-08)
Field: Chemistry — Spectroscopy

Sensitivity Enhancement for Separation-Based Analytical Techniques Utilizing Large Volume Injection and Analyte Derivatization for Trace Analysis in Bio-Fluids Despite the fact that strong routine separation methodologies can give reliable specificity and validity at usual working pharmaceuticals concentrations, they may fail at very low concentration levels. This poses considerable challenges for researchers inves-tigating product purity and therapeutic drug monitoring. Sensitivity enhancement pro-cedures are thus required to maximize the performance of separation techniques. Large volume injection, solid phase extraction/solid phase enrichment (SPE/SPEn), pre-, post-, and in-column derivatization, as well as the use of sensitive detection devices are the simplest strategies for improving sensitivity of the separation-based analytical techniques. Large volume injection of samples with online SPE/SPEn coupled with separation techniques increased sensitivity and improved detection as well as quantification limits without affecting peak shape and system performance. Although the primary purpose of derivatization is to improve sensitivity and selectivity, greener derivatization is growing in popularity and should be considered in analytical chemistry. In general, two strategies are essential for accomplishing greener derivatization goals. The first is the search for and use of ecologically acceptable derivatizing reagents, solvents, and reaction conditions. The second is miniaturization and automation of analytical methods. This review discusses significant advances in separation-based analytical techniques, specifically enrichment approaches and detector signal improvement for pharmaceutical quantification in various matrices at very low concentration levels. As a result of improved analytical systems setup in drug assays, the possibility of high-throughput analyses was also highlighted. Derivatization ; Analyte ; Chromatography ; Sensitivity (control systems) ; Solid phase extraction ; Miniaturization ; Chemistry ; Detector ; Process engineering ; Computer science ; Extraction (chemistry) ; Materials science ; Nanotechnology ; High-performance liquid chromatography Analytical Chemistry and Chromatography ; Microfluidic and Capillary Electrophoresis Applications ; Analytical chemistry methods development
Authors: Desiree Rieks | Andreas Kampmann | Nils‐Claudius Gellrich | Nina Ehlert
Source: Current Directions in Biomedical Engineering (article, 2023-09-01)
Field: Materials Science — Surfaces, Coatings and Films

PH-triggered drug release of ciprofloxacin from layer-by-layer coatings on titanium Abstract Implant-associated infections are still a major issue in implant surgery. Biofilms tend to form on implant surfaces, like titanium, and can hardly be reached by the immune system. Additionally, systemic treatments with antibiotics often fail and cause severe side effects for the patient. Direct delivery of the antibiotic from the implant surface to the surrounding tissue is one approach to solve this problem. To realize this, the application of pH-sensitive coatings on implant surfaces, which release their cargo only if an infection arises, is a promising option. This can be triggered by the decrease of the pH value occurring in infected tissue. For such pH-sensitive systems with integrated drug loading capacity layer-by-layer coatings with weak polyelectrolytes can be used. Here, we present a coating applied on titanium substrates by dip-coating. As negatively charged polyelectrolyte polyacrylic acid, as positively charged poly(allylamine hydrochloride) is used. As an effective drug, the antibiotic ciprofloxacin is incorporated into the coating and the release profiles are recorded. Polyelectrolyte ; Polyacrylic acid ; Coating ; Implant ; Allylamine ; Titanium ; Materials science ; Layer (electronics) ; Ciprofloxacin Hydrochloride ; Biomedical engineering ; Drug delivery ; Ciprofloxacin ; Polymer ; Antibiotics ; Chemical engineering ; Chemistry ; Nanotechnology ; Composite material ; Surgery ; Medicine ; Biochemistry Polymer Surface Interaction Studies ; Orthopedic Infections and Treatments ; Orthopaedic implants and arthroplasty
Authors: Chinmayee Chowde Gowda | John Cavin | Partha Kumbhakar | Chandra Sekhar Tiwary | Rohan Mishra
Source: ChemRxiv (preprint, 2023-11-27)
Field: Materials Science — Materials Chemistry

Flexible Nanogenerators based on Enhanced Flexoelectricity in Mn3O4 Membranes Atomically thin, few-layered membranes of oxides show unique physical and chemical properties compared to their bulk forms. We have exfoliated manganese oxide (Mn3O4) membranes from the naturally occurring mineral Hausmannite and used them to make flexible, high-performance nanogenerators. We observe an enhanced power density in the membrane nanogenerators (NG) with the best-performing device showing a power density of 7.99 mW m-2 compared to 1.04 µW m-2 obtained from NG made up of bulk Mn3O4. We also observe a sensitivity of 108 mV kPa-1 for applied forces < 10 N in the membrane NGs. We attribute the improved performance of these NGs to enhanced flexoelectric response in few-layers of Mn3O4. Using first-principles calculations, we calculate the flexoelectric coefficients of monolayer and bilayer Mn3O4, and find them to be 50 – 100 times larger than other two-dimensional transition metal dichalcogenides (TMDCs). Using a model based on classical beam theory, we find increasing activation of the bending mode with decreasing thickness of the oxide membranes, which in turn leads to a large flexoelectric response. As a proof-of-concept, we made flexible nanogenerators using exfoliated Mn3O4 membranes and used them in self-powered paper-based devices. This research paves the way for the exploration of few-layered membranes of other centrosymmetric oxides for application as energy harvesters. Membrane ; Flexoelectricity ; Materials science ; Monolayer ; Bilayer ; Nanotechnology ; Oxide ; Power density ; Optoelectronics ; Power (physics) ; Chemical engineering ; Composite material ; Chemistry ; Piezoelectricity ; Engineering Nonlocal and gradient elasticity in micro/nano structures ; Advanced Materials and Mechanics ; Innovative Energy Harvesting Technologies
Authors: Suguru ISHIDA | Masataka Ijiri | Toshiko Osada | Satoshi KOBAYASHI
Source: Mechanical Engineering Journal (article, 2023-01-01)
Field: Materials Science — Polymers and Plastics

Improvement in thermal conductivity and mechanical properties for polyamide-6 composite including carbon fiber and alumina particle In this study, we will report the efficiency of hybrid filler for the mechanical properties and the thermal conductivity of Polyamide-6 (PA6) composite. One of the ways to improve the thermal conductivity of the composite is to add fillers to the matrix, but the excessive filler causes the composite to form aggregation and void. They make the mechanical properties and thermal conductivity decline. As the solution to this problem, to use of hybrid filler is expected to realize the lower filler content of composite with keeping the properties. However, the most efficient ratio of hybrid filler is unclear. In this study, PA6 and filler were composited using a twin-shaft melt-mixing machine. A manual injection molding machine was then used to produce test specimens for thermal conductivity measurement and tensile test specimens. Thermal conductivity was measured based on the laser flash method. The structure of the composite was also investigated by fracture surface observation after tensile testing. It is revealed that two types of fillers were composited with PA6 to obtain higher thermal conductivity than that of a single filler with the same filler content. This is because the different shapes of the two fillers made the thermally conductive path. Materials science ; Composite material ; Thermal conductivity ; Composite number ; Filler (materials) ; Ultimate tensile strength ; Polyamide ; Molding (decorative) Natural Fiber Reinforced Composites ; Smart Materials for Construction ; Fiber-reinforced polymer composites
Authors: Marina Jurisch | Cristiano Fantini | Rodinei Augusti | Mariana Ramos Almeida
Source: Journal of Mass Spectrometry (article, 2023-12-25)
Field: Chemistry — Spectroscopy

Combining surface‐enhanced Raman spectroscopy and paper spray mass spectrometry for the identification and confirmation of psychotropic substances in alcoholic beverages Criminal practices in which an individual becomes vulnerable and prone to sexual assault after ingesting drinks spiked with doping substances have become a social concern globally. As forensic protocols require a multi-tiered strategy for chemical evidentiary analysis, the backlog of evidence has become a significant problem in the community. Herein, a fast, sensible, and complementary dual analytical methodology was developed using a single commercial paper substrate for surface-enhanced Raman spectroscopy (SERS) and paper spray mass spectrometry (PS-MS) analysis to identify psychotropic substances added to alcoholic beverages irrefutably. To study and investigate this criminal practice, pharmaceutical formulations containing distinct psychotropic substances (zolpidem, clonazepam, diazepam, and ketamine) were added to drinks typically consumed at parties and festivals (Pilsen beer, açaí Catuaba®, gin tonic, and vodka mixed with Coca-Cola Zero®). A simple liquid-liquid extraction with a low-temperature partitioning (LLE-LTP) procedure was applied to the drinks and effectively minimized matrix effects. As a preliminary analysis, SERS spectra combined with Hierarchical Clustering Analysis (HCA) provided sufficient information to investigate the samples further. The presence of the protonated species for the psychotropic substances in the spiked drinks was readily verified in the mass spectra and confirmed by tandem mass spectrometry. Finally, the results demonstrate the potential of this methodology to be easily implemented into the routine of forensic laboratories and to be further employed at harm reduction tends at parties and festivals to detect contaminated beverages promptly and irrefutably as an efficient tool to prevent such crimes. Chemistry ; Chromatography ; Nitrazepam ; Mass spectrometry ; Diazepam ; Pharmacology Mass Spectrometry Techniques and Applications ; Spectroscopy Techniques in Biomedical and Chemical Research ; Advanced Chemical Sensor Technologies
Authors: Simona Lojevec Hartl | Simon Žakelj | Marija Sollner Dolenc | Vladimir Smrkolj | Janez Mavri
Source: The Protein Journal (article, 2023-06-01)
Field: Chemistry — Electrochemistry

How Azide Ion/Hydrazoic Acid Passes Through Biological Membranes: An Experimental and Computational Study Hydrazoic acid (HN<sub>3</sub>) and its deprotonated form azide ion (N<sub>3</sub><sup>-</sup>) (AHA) are toxic because they inhibit the cytochrome c oxidase complex IV (CoX IV) embedded in the inner mitochondrial membrane that forms part of the enzyme complexes involved in cellular respiration. Critical to its toxicity is the inhibition of CoX IV in the central nervous system and cardiovascular system. Hydrazoic acid is an ionizable species and its affinity for membranes, and the associated permeabilities, depend on the pH values of aqueous media on both sides of the membranes. In this article, we address the permeability of AHA through the biological membrane. In order to understand the affinity of the membrane for the neutral and ionized form of azide, we measured the octanol/water partition coefficients at pH values of 2.0 and 8.0, which are 2.01 and 0.00034, respectively. Using a Parallel Artificial Membrane Permeability Assay (PAMPA) experiment, we measured the effective permeability through the membrane, which is logP<sub>e</sub> - 4.97 and - 5.26 for pH values of 7.4 and pH 8.0, respectively. Experimental permeability was used to validate theoretical permeability, which was estimated by numerically solving a Smoluchowski equation for AHA diffusion through the membrane. We demonstrated that the rate of permeation through the cell membrane of 8.46·10<sup>4</sup> s<sup>-1</sup> is much higher than the rate of the chemical step of CoX IV inhibition by azide of 200 s<sup>-1</sup>. The results of this study show that transport through the membrane does not represent the rate-limiting step and therefore does not control the rate of CoX IV inhibition in the mitochondria. However, the observed dynamics of azide poisoning is controlled by circulatory transport that takes place on a time scale of minutes. Membrane ; Chemistry ; Azide ; Hydrazoic acid ; Lipophilicity ; Partition coefficient ; Membrane permeability ; Biophysics ; Permeability (electromagnetism) ; DIDS ; Biochemistry ; Nuclear chemistry ; Chromatography ; Organic chemistry Electrochemical Analysis and Applications ; Electrochemical sensors and biosensors ; Molecular Sensors and Ion Detection
Authors: Laurine Kaul | Adrian I. Abdo | Tom Coenye | Simon Swift | Andrew C.W. Zannettino | Regine Süss | Katharina Richter
Source: Biofilm (article, 2023-05-17)
Field: Chemistry — Organic Chemistry

In vitro and in vivo evaluation of diethyldithiocarbamate with copper ions and its liposomal formulation for the treatment of Staphylococcus aureus and Staphylococcus epidermidis biofilms Surgical site infections (SSIs) are mainly caused by <i>Staphylococcus aureus</i> (<i>S. aureus</i>) and <i>Staphylococcus epidermidis</i> (<i>S. epidermidis</i>) biofilms. Biofilms are aggregates of bacteria embedded in a self-produced matrix that offers protection against antibiotics and promotes the spread of antibiotic-resistance in bacteria. Consequently, antibiotic treatment frequently fails, resulting in the need for alternative therapies. The present study describes the <i>in vitro</i> efficacy of the Cu(DDC)<sub>2</sub> complex (2:1 M ratio of diethyldithiocarbamate (DDC<sup>-</sup>) and Cu<sup>2+</sup>) with additional Cu<sup>2+</sup> against <i>S. aureus</i> and <i>S. epidermidis</i> biofilms in models mimicking SSIs and <i>in vitro</i> antibacterial activity of a liposomal Cu(DDC)<sub>2</sub> + Cu<sup>2+</sup> formulation. The <i>in vitro</i> activity on <i>S. aureus</i> and <i>S. epidermidis</i> biofilms grown on two hernia mesh materials and in a wound model was determined by colony forming unit (CFU) counting. Cu<sup>2+</sup>-liposomes and Cu(DDC)<sub>2</sub>-liposomes were prepared, and their antibacterial activity was assessed <i>in vitro</i> using the alamarBlue assay and CFU counting and <i>in vivo</i> using a <i>Galleria mellonella</i> infection model. The combination of 35 μM DDC<sup>-</sup> and 128 μM Cu<sup>2+</sup> inhibited <i>S. aureus</i> and <i>S. epidermidis</i> biofilms on meshes and in a wound infection model. Cu(DDC)<sub>2</sub>-liposomes + free Cu<sup>2+</sup> displayed similar antibiofilm activity to free Cu(DDC)<sub>2</sub> + Cu<sup>2+</sup>, and significantly increased the survival of <i>S. epidermidis</i>-infected larvae. Whilst Cu(DDC)<sub>2</sub> + Cu<sup>2+</sup> showed substantial antibiofilm activity <i>in vitro</i> against clinically relevant biofilms, its application in mammalian <i>in vivo</i> models is limited by solubility. The liposomal Cu(DDC)<sub>2</sub> + Cu<sup>2+</sup> formulation showed antibiofilm activity <i>in vitro</i> and antibacterial activity and low toxicity in <i>G. mellonella</i>, making it a suitable water-soluble formulation for future application on infected wounds in animal trials. Staphylococcus epidermidis ; Staphylococcus aureus ; Microbiology ; Biofilm ; In vivo ; In vitro ; Antibiotics ; Chemistry ; Bacteria ; Biology ; Biochemistry Antimicrobial agents and applications ; Bacterial biofilms and quorum sensing ; Antimicrobial Peptides and Activities
Authors: Matthew J. Keller | Qiu Zhang | Shuo Qian | Brian Sanders | Hugh O’Neill | Robert L. Hettich
Source: Analytical Chemistry (article, 2023-12-27)
Field: Chemistry — Physical and Theoretical Chemistry

Characterization of the <i>In Vivo</i> Deuteration of Native Phospholipids by Mass Spectrometry Yields Guidelines for Their Regiospecific Customization Customization of deuterated biomolecules is vital for many advanced biological experiments including neutron scattering. However, because it is challenging to control the proportion and regiospecificity of deuterium incorporation in live systems, often only two or three synthetic lipids are mixed together to form simplistic model membranes. This limits the applicability and biological accuracy of the results generated with these synthetic membranes. Despite some limited prior examination of deuterating <i>Escherichia coli</i> lipids <i>in vivo</i>, this approach has not been widely implemented. Here, an extensive mass spectrometry-based profiling of <i>E. coli</i> phospholipid deuteration states with several different growth media was performed, and a computational method to describe deuterium distributions with a one-number summary is introduced. The deuteration states of 36 lipid species were quantitatively profiled in 15 different growth conditions, and tandem mass spectrometry was used to reveal deuterium localization. Regressions were employed to enable the prediction of lipid deuteration for untested conditions. Small-angle neutron scattering was performed on select deuterated lipid samples, which validated the deuteration states calculated from the mass spectral data. Based on these experiments, guidelines for the design of specifically deuterated phospholipids are described. This unlocks even greater capabilities from neutron-based techniques, enabling experiments that were formerly impossible. Chemistry ; Deuterium ; Mass spectrometry ; Biomolecule ; Characterization (materials science) ; Tandem mass spectrometry ; Membrane ; Tandem ; Neutron scattering ; Chromatography ; Analytical Chemistry (journal) ; Neutron ; Nanotechnology ; Nuclear physics ; Biochemistry thermodynamics and calorimetric analyses ; Chemical Reactions and Isotopes ; Mass Spectrometry Techniques and Applications
Authors: Stan Perchepied | Zhuoheng Zhou | Goran Mitulović | Sebastiaan Eeltink
Source: Journal of Separation Science (review, 2023-09-01)
Field: Chemistry — Spectroscopy

Exploiting ion‐mobility mass spectrometry for unraveling proteome complexity Ion mobility spectrometry-mass spectrometry (IMS-MS) is experiencing rapid growth in proteomic studies, driven by its enhancements in dynamic range and throughput, increasing the quantitation precision, and the depth of proteome coverage. The core principle of ion mobility spectrometry is to separate ions in an inert gas under the influence of an electric field based on differences in drift time. This minireview provides an introduction to IMS operation modes and a description of advantages and limitations is presented. Moreover, the principles of trapped IMS-MS (TIMS-MS), including parallel accumulation-serial fragmentation are discussed. Finally, emerging applications linked to TIMS focusing on sample throughput (in clinical proteomics) and sensitivity (single-cell proteomics) are reviewed, and the possibilities of intact protein analysis are discussed. Ion-mobility spectrometry ; Mass spectrometry ; Proteome ; Proteomics ; Chemistry ; Fragmentation (computing) ; Ion-mobility spectrometry–mass spectrometry ; Ion ; Analytical Chemistry (journal) ; Tandem mass spectrometry ; Nanotechnology ; Chromatography ; Selected reaction monitoring ; Computer science ; Materials science ; Biochemistry Mass Spectrometry Techniques and Applications ; Advanced Proteomics Techniques and Applications
Authors: Johanna Tüshaus | Amirhossein Sakhteman | Severin Lechner | Matthew The | Eike Mucha | Christoph Krisp | Jürgen Schlegel | Claire Delbridge | Bernhard Küster
Source: bioRxiv (Cold Spring Harbor Laboratory) (preprint, 2023-06-08)
Field: Chemistry — Spectroscopy

A region-resolved proteomic map of the human brain enabled by high-throughput proteomics Abstract Substantial efforts are underway that aim to deepen our understanding of human brain morphology, structure and function using high-resolution imaging as well has high-content molecular profiling technologies. The current work adds to these efforts by providing a comprehensive and quantitative protein expression map of 13 anatomically distinct brain regions covering more than 10,000 proteins. This was enabled by the optimization, characterization and implementation of a high-sensitivity and high-throughput micro-flow liquid chromatography timsTOF tandem mass spectrometry system (LC-MS/MS) capable of analyzing &gt;2,000 consecutive samples prepared from formalin fixed paraffin embedded (FFPE) material. Analysis of this proteomic resource highlighted e.g. brain region-enriched protein expression patterns and functional protein classes, protein localization differences between brain regions and individual protein markers for specific brain regions. To facilitate access to and ease further mining of the data by the scientific community, all data can be explored online in a purpose-built Shiny App ( https://brain-region-atlas.proteomics.ls.tum.de ). Proteomics ; Computational biology ; High resolution ; Profiling (computer programming) ; Protein expression ; Human Protein Atlas ; Human brain ; Computer science ; Neuroscience ; Biology ; Gene ; Biochemistry Advanced Proteomics Techniques and Applications ; Metabolomics and Mass Spectrometry Studies ; Mass Spectrometry Techniques and Applications