1,119 results match your criteria conditions transforms

Eradication of Intracellular Salmonella Typhimurium by Polyplexes of Acid-Transforming Chitosan and Fragment DNA.

Macromol Biosci 2021 Apr 18:e2000408. Epub 2021 Apr 18.

132 Sprague Hall, Irvine, CA, 92697, USA.

Antibiotics are highly successful against microbial infections. However, current challenges include rising antibiotic resistance rates and limited efficacy against intracellular pathogens. A novel form of a nanomaterial-based antimicrobial agent is investigated for efficient treatment of an intracellular Salmonella enterica sv Typhimurium infection. Read More

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Preparation of poly(sodium 4-styrene sulfonate) grafted magnetic chitosan microspheres for adsorption of cationic dyes.

Int J Biol Macromol 2021 Apr 15;181:810-823. Epub 2021 Apr 15.

School of Chemical Engineering and Technology, North University of China, Taiyuan 030051, PR China. Electronic address:

A novel adsorbent with high adsorption capacity to remove cationic dyes was synthesized. Sodium 4-styrene sulfonate (SSS) was grafted polymerization on the surface of magnetic chitosan microspheres via -NH/SO surface initiating system, obtaining MCS-g-PSSS microspheres. The grafted microsphere was characterized by Fourier transforms infrared spectroscopy, X-ray diffraction, scanning electron microscopy, X-ray photoelectron spectroscopy, vibration sample magnetometer and the Brunauer-Emmett-Teller. Read More

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Quantifying Preservation Potential: Lipid Degradation in a Mars-Analog Circumneutral Iron Deposit.

Astrobiology 2021 Apr 8. Epub 2021 Apr 8.

Department of Earth Science and Engineering, Impacts and Astromaterials Research Centre, Imperial College London, London, United Kingdom.

Comparisons between the preservation potential of Mars-analog environments have historically been qualitative rather than quantitative. Recently, however, laboratory-based artificial maturation combined with kinetic modeling techniques have emerged as a potential means by which the preservation potential of solvent-soluble organic matter can be quantified in various Mars-analog environments. These methods consider how elevated temperatures, pressures, and organic-inorganic interactions influence the degradation of organic biomarkers post-burial. Read More

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Superior Wear-Resistance of TiCT Multilayer Coatings.

ACS Nano 2021 Apr 6. Epub 2021 Apr 6.

Department of Chemical Engineering, Biotechnology and Materials, FCFM, University of Chile, Santiago, 8370415, Chile.

Owing to MXenes' tunable mechanical properties induced by their structural and chemical diversity, MXenes are believed to compete with state-of-the-art 2D nanomaterials such as graphene regarding their tribological performance. Their nanolaminate structure offers weak interlayer interactions and an easy-to-shear ability to render them excellent candidates for solid lubrication. However, the acting friction and wear mechanisms are yet to be explored. Read More

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Light-Adapted Charge-Separated State of Photosystem II: Structural and Functional Dynamics of the Closed Reaction Center.

Plant Cell 2021 Jan 25. Epub 2021 Jan 25.

Institute of Plant Biology, Biological Research Centre, Szeged, Hungary.

Photosystem II (PSII) uses solar energy to oxidize water and delivers electrons for life on Earth. The photochemical reaction center of PSII is known to possess two stationary states. In the open state (PSIIO), the absorption of a single photon triggers electron-transfer steps, which convert PSII into the charge-separated closed state (PSIIC). Read More

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January 2021

Base-Mediated Intramolecular Cyclization of α-Nitroethylallenic Esters as a Synthetic Route to 5-Hydroxy-3-pyrrolin-2-ones.

J Org Chem 2021 Apr 31;86(8):5630-5638. Epub 2021 Mar 31.

Medicinal and Process Chemistry Division, CSIR-Central Drug Research Institute, BS-10/1, Sector 10, Jankipuram extension, Sitapur Road, P.O. Box 173, Lucknow 226031, India.

An unprecedented CsCO-mediated intramolecular cyclization/rearrangement cascade that transforms α-nitroethylallenic esters to functionalized pyrrolin-2-ones has been uncovered. This reaction provides a new and practical approach for the synthesis of medicinally privileged 5-hydroxy-3-pyrrolin-2-ones under mild conditions. The broad potential of this new method was demonstrated by an efficient Au/Ag-catalyzed heteroarylation of 5-hydroxy-3-pyrrolin-2-ones employing electron-rich heteroarenes to furnish heteroaryl-lactam derivatives. Read More

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Development of Wide Field of View Three-Dimensional Field Ion Microscopy and High-Fidelity Reconstruction Algorithms to the Study of Defects in Nuclear Materials.

Microsc Microanal 2021 Apr;27(2):365-384

Normandie Université, UNIROUEN, INSA Rouen, CNRS, Groupe de Physique des Matériaux, Rouen76000, France.

This article presents a fast and highly efficient algorithm developed to reconstruct a three-dimensional (3D) volume with a high spatial precision from a set of field ion microscopy (FIM) images, and specific tools developed to characterize crystallographic lattice and defects. A set of FIM digital images and image processing algorithms allow the construction of a 3D reconstruction of the sample at the atomic scale. The capability of the 3D FIM to resolve the crystallographic lattice and the finest defects in metals opens a new way to analyze materials. Read More

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Dietary restriction transforms the mammalian protein persulfidome in a tissue-specific and cystathionine γ-lyase-dependent manner.

Nat Commun 2021 03 19;12(1):1745. Epub 2021 Mar 19.

Department of Cardiovascular and Metabolic Sciences, Cleveland Clinic Lerner Research Institute, Cleveland, OH, USA.

Hydrogen sulfide (HS) is a cytoprotective redox-active metabolite that signals through protein persulfidation (R-SSH). Despite the known importance of persulfidation, tissue-specific persulfidome profiles and their associated functions are not well characterized, specifically under conditions and interventions known to modulate HS production. We hypothesize that dietary restriction (DR), which increases lifespan and can boost HS production, expands tissue-specific persulfidomes. Read More

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Reformulation of an extant ATPase active site to mimic ancestral GTPase activity reveals a nucleotide base requirement for function.

Elife 2021 Mar 11;10. Epub 2021 Mar 11.

Laboratory of Molecular Biology, National Cancer Institute, National Institutes of Health, Bethesda, United States.

Hydrolysis of nucleoside triphosphates releases similar amounts of energy. However, ATP hydrolysis is typically used for energy-intensive reactions, whereas GTP hydrolysis typically functions as a switch. SpoIVA is a bacterial cytoskeletal protein that hydrolyzes ATP to polymerize irreversibly during sporulation. Read More

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Molecular Insights into Warfarin Sodium 2-Propanol Solvate Solid Form Changes and Disproportionation Using a Low Volume Two-Stage Dissolution Approach.

Mol Pharm 2021 04 9;18(4):1779-1791. Epub 2021 Mar 9.

Lachman Institute for Pharmaceutical Analysis, Long Island University, 75 Dekalb Ave, Brooklyn, New York11201, United States.

The current research work focuses on understanding the reported discrepancies and our observations in the dissolution profiles of warfarin sodium tablets and potential patient-based failure modes during oral warfarin therapy. It was hypothesized that freely soluble crystalline warfarin sodium (WAR) at first transforms into noncrystalline warfarin sodium (WAR) under stress conditions. The WAR → WAR conversion facilitates the rapid formation of the poorly soluble unionized form, which could lead to dissolution failures and potential poor in vivo performance. Read More

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Updates on metaQuantome Software for Quantitative Metaproteomics.

J Proteome Res 2021 Apr 8;20(4):2130-2137. Epub 2021 Mar 8.

Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota Twin Cities, Minneapolis, Minnesota 55455, United States.

metaQuantome is a software suite that enables the quantitative analysis, statistical evaluation. and visualization of mass-spectrometry-based metaproteomics data. In the latest update of this software, we have provided several extensions, including a step-by-step training guide, the ability to perform statistical analysis on samples from multiple conditions, and a comparative analysis of metatranscriptomics data. Read More

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Concurrent self-regulated autonomous synthesis and functionalization of pH-responsive giant vesicles by a chemical pH oscillator.

Soft Matter 2021 Apr;17(15):4011-4018

Department of Earth and Planetary Science and Origins of Life Initiative, Harvard University, 20 Oxford Street, Cambridge, Massachusetts 02138, USA. and Santa Fe Institute, Santa Fe, New Mexico 87501, USA.

The semibatch BrO3--SO32- pH oscillator serves as the radical source for the in situ polymerization of the pH-responsive 2-(diisopropylamino)-ethyl methacrylate monomer on poly(ethylene-glycol)-macroCTA chain and generates an amphiphilic block copolymer. These building blocks concurrently self-assemble to micelles and then transforms to vesicles as the chain length of the hydrophobic block growths. Large amplitude oscillations in the concentration of H+ by the semibatch BrO3--SO32- are provoked when the conditions in the system are favorable. Read More

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Fluorocarbon-Functionalized Superhydrophobic Metal-Organic Framework: Enhanced CO Uptake via Photoinduced Postsynthetic Modification.

Inorg Chem 2021 Mar 3;60(6):3823-3833. Epub 2021 Mar 3.

Chemistry and Physics of Materials Unit, School of Advanced Materials (SAMat), Jawaharlal Nehru Centre for Advanced Scientific Research, Jakkur, Bangalore-560064 (India).

The design and synthesis of porous materials for selective capture of CO in the presence of water vapor is of paramount importance in the context of practical separation of CO from the flue gas stream. Here, we report the synthesis and structural characterization of a photoresponsive fluorinated MOF {[Cd(bpee)(hfbba)]·EtOH} () constructed by using 4,4'-(hexafluoroisopropylidene)bis(benzoic acid) (hfbba), Cd(NO), and 1,2-bis(4-pyridyl)ethylene (bpee) as building units. Due to the presence of the fluoroalkyl -CF functionality, compound exhibits superhydrophobicity, which is validated by both water vapor adsorption and contact angle measurements (152°). Read More

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Transpupillary Two-photon In vivo Imaging of the Mouse Retina.

J Vis Exp 2021 02 13(168). Epub 2021 Feb 13.

John F. Hardesty, MD Department of Ophthalmology and Visual Sciences, Washington University School of Medicine; Department of Neuroscience, Washington University School of Medicine; Hope Center for Neurological Disorders, Washington University School of Medicine;

The retina transforms light signals from the environment into electrical signals that are propagated to the brain. Diseases of the retina are prevalent and cause visual impairment and blindness. Understanding how such diseases progress is critical to formulating new treatments. Read More

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February 2021

Transient increase in VEGF-A leads to cardiac tube anomalies and increased risk of congenital heart malformations.

Anat Rec (Hoboken) 2021 Feb 23. Epub 2021 Feb 23.

Department of Biomedical Engineering, Oregon Health and Science University, Portland, Oregon, USA.

Vascular endothelial growth factor (VEGF) plays a critical role during early heart development. Clinical evidence shows that conditions associated with changes in VEGF signaling in utero are correlated with an increased risk of congenital heart defects (CHD) in newborns. However, how malformations develop after abnormal VEGF exposure is unknown. Read More

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February 2021

Supervised machine learning approach to molecular dynamics forecast of SARS-CoV-2 spike glycoproteins at varying temperatures.

MRS Adv 2021 Feb 17:1-6. Epub 2021 Feb 17.

Stony Brook University, Stony Brook, NY 11790 USA.

Abstract: Molecular dynamics (MD) simulations are a widely used technique in modeling complex nanoscale interactions of atoms and molecules. These simulations can provide detailed insight into how molecules behave under certain environmental conditions. This work explores a machine learning (ML) solution to predicting long-term properties of SARS-CoV-2 spike glycoproteins (S-protein) through the analysis of its nanosecond backbone RMSD (root-mean-square deviation) MD simulation data at varying temperatures. Read More

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February 2021

Stabilization and electronic topological transition of hydrogen-rich metal LiMoH under high pressures from first-principles predictions.

Sci Rep 2021 Feb 18;11(1):4079. Epub 2021 Feb 18.

Extreme Conditions Physics Research Laboratory (ECPRL) and Physics of Energy Materials Research Unit, Department of Physics, Faculty of Science, Chulalongkorn University, Bangkok, 10330, Thailand.

Regarded as doped binary hydrides, ternary hydrides have recently become the subject of investigation since they are deemed to be metallic under pressure and possibly potentially high-temperature superconductors. Herein, the candidate structure of LiMoH is predicted by exploiting the evolutionary searching. Its high-pressure phase adopts a hexagonal structure with P6/mcm space group. Read More

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February 2021

Polymorphism of benzylthiouracil, an active pharmaceutical ingredient against hyperthyroidism.

Int J Pharm 2021 Apr 11;598:120378. Epub 2021 Feb 11.

Grup de Caracterització de Materials, Departament de Física and Barcelona Research Center in Multiscale Science and Engineering, Universitat Politècnica de Catalunya, EEBE, Campus Diagonal-Besòs, Av. Eduard Maristany 10-14, 08019 Barcelona, Catalunya, Spain.

The crystal structures of dimorphic benzylthiouracil, a drug against hyperthyroidism, have been redetermined and the atom coordinates of the two independent molecules of form I have been obtained for the first time. The dimorphism convincingly demonstrates the conformational versatility of the benzylthiouracil molecule. It has been established through calorimetric studies that the low-temperature form II transforms endothermically (ΔH = 5. Read More

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Contextualizing the biological relevance of standardized high-resolution respirometry to assess mitochondrial function in permeabilized human skeletal muscle.

Acta Physiol (Oxf) 2021 04 3;231(4):e13625. Epub 2021 Mar 3.

Innland University of Applied Sciences, Lillehammer, Norway.

Aim: This study sought to provide a statistically robust reference for measures of mitochondrial function from standardized high-resolution respirometry with permeabilized human skeletal muscle (ex vivo), compare analogous values obtained via indirect calorimetry, arterial-venous O differences and P magnetic resonance spectroscopy (in vivo) and attempt to resolve differences across complementary methodologies as necessary.

Methods: Data derived from 831 study participants across research published throughout March 2009 to November 2019 were amassed to examine the biological relevance of ex vivo assessments under standard conditions, ie physiological temperatures of 37°C and respiratory chamber oxygen concentrations of ~250 to 500 μmol/L.

Results: Standard ex vivo-derived measures are lower (Z ≥ 3. Read More

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GLAGC: Adaptive Dual-Gamma Function for Image Illumination Perception and Correction in the Wavelet Domain.

Sensors (Basel) 2021 Jan 27;21(3). Epub 2021 Jan 27.

School of Mechanical and Electronic Engineering, Wuhan University of Technology, Wuhan 430074, China.

Low-contrast or uneven illumination in real-world images will cause a loss of details and increase the difficulty of pattern recognition. An automatic image illumination perception and adaptive correction algorithm, termed as GLAGC, is proposed in this paper. Based on Retinex theory, the illumination of an image is extracted through the discrete wavelet transform. Read More

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January 2021

Chemical Composition and Molecular-Specific Optical Properties of Atmospheric Brown Carbon Associated with Biomass Burning.

Environ Sci Technol 2021 02 27;55(4):2511-2521. Epub 2021 Jan 27.

Department of Earth and Planetary Sciences, Weizmann Institute of Science, Rehovot 76100, Israel.

This study provides molecular insights into the light absorption properties of biomass burning (BB) brown carbon (BrC) through the chemical characterization of tar condensates generated from heated wood pellets at oxidative and pyrolysis conditions. Both liquid tar condensates separated into "darker oily" and "lighter aqueous" immiscible phases. The molecular composition of these samples was investigated using reversed-phase liquid chromatography coupled with a photodiode array detector and a high-resolution mass spectrometer. Read More

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February 2021

Ionic Phases of Ammonia-Rich Hydrate at High Densities.

Phys Rev Lett 2021 Jan;126(1):015702

Key Laboratory of Materials Physics, Institute of Solid State Physics, HFIPS, Chinese Academy of Sciences, Hefei 230031, China.

Mixtures of ammonia and water are major components of the "hot ice" mantle regions of icy planets. The ammonia-rich ammonia hemihydrate (AHH) plays a pivotal role as it precipitates from water-rich mixtures under pressure. It has been predicted to form ionic high-pressure structures, with fully disintegrated water molecules. Read More

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January 2021

Traffic accident detection and condition analysis based on social networking data.

Accid Anal Prev 2021 Mar 15;151:105973. Epub 2021 Jan 15.

Department of Information and Communication Engineering, Inha University, Incheon, South Korea. Electronic address:

Accurate detection of traffic accidents as well as condition analysis are essential to effectively restoring traffic flow and reducing serious injuries and fatalities. This goal can be obtained using an advanced data classification model with a rich source of traffic information. Several systems based on sensors and social networking platforms have been presented recently to detect traffic events and monitor traffic conditions. Read More

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COVID-19 era healthcare ethics education: Cultivating educational and moral resilience.

Nurs Ethics 2021 Feb 11;28(1):58-65. Epub 2021 Jan 11.

Bern University of Applied Sciences, Switzerland; University of Zurich, Switzerland.

The COVID-19 pandemic crisis has had profound effects on global health, healthcare, and public health policy. It has also impacted education. Within undergraduate healthcare education of doctors, nurses, and allied professions, rapid shifts to distance learning and pedagogic content creation within new realities, demands of healthcare practice settings, shortened curricula, and/or earlier graduation have also challenged ethics teaching in terms of curriculum allotments or content specification. Read More

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February 2021

The simultaneous use of Emotional suppression and Situation selection to regulate emotions incrementally favors physiological responses.

BMC Psychol 2020 Dec 11;8(1):133. Epub 2020 Dec 11.

Institute of Psychology, University of Lausanne, Lausanne, Switzerland.

Background: Emotion regulation alters the trajectories of emotional responses and, when effective, transforms the emotional responses to help individuals adapt to their environment. Previous research has mainly focused on the efficiency of regulation strategies performed individually at a given time. Yet, in daily life, it is likely that several strategies are often combined. Read More

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December 2020

Molecular links between endocrine, nervous and immune system during chronic stress.

Brain Behav 2021 Feb 8;11(2):e01960. Epub 2020 Dec 8.

Department of Medical and Surgical Sciences, University of Foggia, Foggia, Italy.

Introduction: The stress response is different in various individuals, however, the mechanisms that could explain these distinct effects are not well known and the molecular correlates have been considered one at the time. Particular harmful conditions occur if the subject, instead to cope the stressful events, succumb to them, in this case, a cascade reaction happens that through different signaling causes a specific reaction named "sickness behaviour." The aim of this article is to review the complex relations among important molecules belonging to Central nervous system (CNS), immune system (IS), and endocrine system (ES) during the chronic stress response. Read More

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February 2021

Synchronized oscillations, traveling waves, and jammed clusters induced by steric interactions in active filament arrays.

Soft Matter 2021 Jan 8;17(4):1091-1104. Epub 2020 Dec 8.

Department of Physics, Indian Institute of Technology Bombay, Mumbai, India.

Autonomous active, elastic filaments that interact with each other to achieve cooperation and synchrony underlie many critical functions in biology. The mechanisms underlying this collective response and the essential ingredients for stable synchronization remain a mystery. Inspired by how these biological entities integrate elasticity with molecular motor activity to generate sustained oscillations, a number of synthetic active filament systems have been developed that mimic oscillations of these biological active filaments. Read More

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January 2021

Quantized Constant-Q Gabor Atoms for Sparse Binary Representations of Cyber-Physical Signatures.

Milton A Garcés

Entropy (Basel) 2020 Aug 26;22(9). Epub 2020 Aug 26.

Infrasound Laboratory, University of Hawaii, Manoa, HI 96740, USA.

Increased data acquisition by uncalibrated, heterogeneous digital sensor systems such as smartphones present new challenges. Binary metrics are proposed for the quantification of cyber-physical signal characteristics and features, and a standardized constant-Q variation of the Gabor atom is developed for use with wavelet transforms. Two different continuous wavelet transform (CWT) reconstruction formulas are presented and tested under different signal to noise ratio (SNR) conditions. Read More

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Measuring the Tangle of Three-Qubit States.

Entropy (Basel) 2020 Apr 11;22(4). Epub 2020 Apr 11.

Departament de Física Quàntica i Astrofísica and Institut de Ciències del Cosmos (ICCUB), Universitat de Barcelona, Martí i Franquès 1, 08028 Barcelona, Spain.

We present a quantum circuit that transforms an unknown three-qubit state into its canonical form, up to relative phases, given many copies of the original state. The circuit is made of three single-qubit parametrized quantum gates, and the optimal values for the parameters are learned in a variational fashion. Once this transformation is achieved, direct measurement of outcome probabilities in the computational basis provides an estimate of the tangle, which quantifies genuine tripartite entanglement. Read More

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Dynamics of grain boundary premelting.

Sci Rep 2020 Dec 3;10(1):21074. Epub 2020 Dec 3.

Access e.V., Intzestr. 5, 52072, Aachen, Germany.

The mechanical strength of a polycrystalline material can be drastically weakened by a phenomenon known as grain boundary (GB) premelting that takes place, owing to the so-called disjoining potential, when the dry GB free energy [Formula: see text] exceeds twice the free energy of the solid-liquid interface [Formula: see text]. While previous studies of GB premelting are all limited to equilibrium conditions, we use a multi-phase field model to analyze premelting dynamics by simulating the steady-state growth of a liquid layer along a dry GB in an insulated channel and the evolution of a pre-melted polycrystalline microstructure. In both cases, our results reveal the crucial influence of the disjoining potential. Read More

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December 2020