61,650 results match your criteria thermodynamic stability

"Two Ships in a Bottle" Design for Zn-Ag-O Catalyst Enabling Selective and Long-Lasting CO Electroreduction.

J Am Chem Soc 2021 Apr 14. Epub 2021 Apr 14.

Department of Chemical Engineering, Waterloo Institute for Nanotechnology, Waterloo Institute for Sustainable Energy, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada.

Electrochemical CO reduction (CORR) using renewable energy sources represents a sustainable means of producing carbon-neutral fuels. Unfortunately, low energy efficiency, poor product selectivity, and rapid deactivation are among the most intractable challenges of CORR electrocatalysts. Here, we strategically propose a "two ships in a bottle" design for ternary Zn-Ag-O catalysts, where ZnO and Ag phases are twinned to constitute an individual ultrafine nanoparticle impregnated inside nanopores of an ultrahigh-surface-area carbon matrix. Read More

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Reduced phase stability and faster formation/dissociation kinetics in confined methane hydrate.

Proc Natl Acad Sci U S A 2021 Apr;118(16)

University Grenoble Alpes, CNRS, LIPhy, 38000 Grenoble, France

The mechanisms involved in the formation/dissociation of methane hydrate confined at the nanometer scale are unraveled using advanced molecular modeling techniques combined with a mesoscale thermodynamic approach. Using atom-scale simulations probing coexistence upon confinement and free energy calculations, phase stability of confined methane hydrate is shown to be restricted to a narrower temperature and pressure domain than its bulk counterpart. The melting point depression at a given pressure, which is consistent with available experimental data, is shown to be quantitatively described using the Gibbs-Thomson formalism if used with accurate estimates for the pore/liquid and pore/hydrate interfacial tensions. Read More

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How bulk nanobubbles are stable over a wide range of temperatures.

J Colloid Interface Sci 2021 Mar 24;596:184-198. Epub 2021 Mar 24.

Center for Combustion Energy, Key Laboratory for Thermal Science and Power Engineering of Ministry of Education, Department of Energy and Power, Engineering, Tsinghua University, Beijing 100084, China. Electronic address:

Hypothesis: Bulk nanobubbles are nanoscopic gaseous domains in an aqueous solution. Their surprising long-term stability remains controversial due to the widespread assumption that spherical bubbles cannot achieve stable equilibrium. To uncover the intrinsic mechanisms underlying stabilization, the thermodynamic behavior of nanobubbles in water over a wide range of temperatures is explored. Read More

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Performance and Limitations of Nickel-Doped Chromite Anodes in Electrolyte-Supported Solid Oxide Fuel Cells.

ChemSusChem 2021 Apr 12. Epub 2021 Apr 12.

German Aerospace Center DLR Institute of Technical Thermodynamics: Deutsches Zentrum fur Luft- und Raumfahrt DLR Institut fur Technische Thermodynamik, ECE, GERMANY.

Ni-doped chromite anodes were integrated into electrolyte-supported cells (ESC) with 5x5 cm 2 size and investigated in fuel cell mode with H 2 /H 2 O fuel gas. Both a stoichiometric and a nominally A-site deficient chromite anode material showed promising performance at 860 °C approaching the ones of state-of-the-art Ni/Gd-doped ceria (CGO) anodes. While the difference in polarization resistance was small, an increased ohmic resistance of the perovskite anodes was observed, which is related to limited electronic conductivity of the perovskites. Read More

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High-Stability Memristive Devices Based on Pd Conductive Filaments and Its Applications in Neuromorphic Computing.

ACS Appl Mater Interfaces 2021 Apr 12. Epub 2021 Apr 12.

Chinese Academy of Sciences Institute of Microelectronics, Beijing 100029, China.

Memristive devices with high-density and high-speed performance have considerable potential for neuromorphic computing applications in data storage and artificial synapses. However, current memristive devices that are based on conductive filaments, such as silver, are unstable owing to the high mobility and low thermodynamic stability of the filaments. A high-quality SnSe film was deposited using the pulsed laser deposition technology, and high-performance Pd/SnSe/NSTO devices were fabricated. Read More

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Thermodynamic Stability of G-Quadruplexes: Impact of Sequence and Environment.

Chembiochem 2021 Apr 12. Epub 2021 Apr 12.

Universität Greifswald Mathematisch-Naturwissenschaftliche Fakultät: Universitat Greifswald Mathematisch-Naturwissenschaftliche Fakultat, Institut für Biochemie, Felix-Hausdorff-Str. 4, 17489, Greifswald, GERMANY.

G-quadruplexes have attracted growing interest in recent years due to their occurrence in vivo and their possible biological functions. In addition to being promising targets for drug design, these four-stranded nucleic acid structures have also been recognized as versatile tools for various technological applications. Whereas a large number of studies have yielded insight into their remarkable structural diversity, our current knowledge on G-quadruplex stabilities as a function of sequence and environmental factors only gradually emerges with an expanding collection of thermodynamic data. Read More

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ThermoScan: Semi-automatic Identification of Protein Stability Data From PubMed.

Front Mol Biosci 2021 25;8:620475. Epub 2021 Mar 25.

Department of Pharmacy and Biotechnology (FaBiT), University of Bologna, Bologna, Italy.

During the last years, the increasing number of DNA sequencing and protein mutagenesis studies has generated a large amount of variation data published in the biomedical literature. The collection of such data has been essential for the development and assessment of tools predicting the impact of protein variants at functional and structural levels. Nevertheless, the collection of manually curated data from literature is a highly time consuming and costly process that requires domain experts. Read More

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Iminostilbene, a novel small-molecule modulator of PKM2, suppresses macrophage inflammation in myocardial ischemia-reperfusion injury.

J Adv Res 2021 Mar 9;29:83-94. Epub 2020 Sep 9.

Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.

Introduction: Inflammation is a key factor in myocardial ischemia/reperfusion (MI/R) injury. Targeting leucocyte-mediated inflammation is an important strategy for MI/R therapy. Iminostilbene (ISB), a simple dibenzoazepine small molecule compound, has a strong anti-neurodegenerative effect. Read More

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High-pressure small-angle X-ray scattering cell for biological solutions and soft materials.

J Appl Crystallogr 2021 Feb 1;54(Pt 1):111-122. Epub 2021 Feb 1.

Cornell High Energy Synchrotron Source (CHESS), Cornell University, Ithaca, NY 14853, USA.

Pressure is a fundamental thermodynamic parameter controlling the behavior of biological macromolecules. Pressure affects protein denaturation, kinetic parameters of enzymes, ligand binding, membrane permeability, ion trans-duction, expression of genetic information, viral infectivity, protein association and aggregation, and chemical processes. In many cases pressure alters the molecular shape. Read More

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February 2021

First-Principles Study on Electronic, Magnetic, Optical, Mechanical, and Thermodynamic Properties of Semiconducting Gadolinium Phosphide in GGA, GGA+U, mBJ, GGA+SOC and GGA+SOC+U approaches.

J Supercond Nov Magn 2021 Apr 4:1-16. Epub 2021 Apr 4.

Center for Advanced Studies in Physics (CASP), GC University, Lahore, 54000 Pakistan.

In the current article, the electronic, magnetic, and optical properties of GdP in the hypothetical zinc blende structure have been discussed by using GGA, GGA+U, mBJ, GGA+SOC, and GGA+SOC+U approaches. The energy vs volume plots in the three magnetic states suggest the ferromagnetic phase to be the stable phase of GdP. The cohesive energy calculated for GdP is negative, suggesting the stability of the compound. Read More

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Nanocomposite sponges for enhancing intestinal residence time following oral administration.

J Control Release 2021 Apr 7. Epub 2021 Apr 7.

Univ Lyon, Université Claude Bernard Lyon 1, CNRS, LAGEPP UMR 5007, 43 Boulevard du 11 Novembre 1918, F-69622 Villeurbanne, France. Electronic address:

In this work, nanocomposites that combine mucopenetrating and mucoadhesive properties in a single system are proposed as innovative strategy to increase drug residence time in the intestine following oral administration. To this aim, novel mucoadhesive chitosan (CH) sponges loaded with mucopenetrating nanoemulsions (NE) were developed via freeze-casting technique. The NE mucopenetration ability was determined studying the surface affinity and thermodynamic binding of the nanosystem with mucins. Read More

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The intracellular environment affects protein-protein interactions.

Proc Natl Acad Sci U S A 2021 Mar;118(11)

Key Laboratory of Magnetic Resonance in Biological Systems, State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, National Center for Magnetic Resonance in Wuhan, Wuhan National Laboratory for Optoelectronics, Wuhan Institute of Physics and Mathematics, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, 430071 Wuhan, China;

Protein-protein interactions are essential for life but rarely thermodynamically quantified in living cells. In vitro efforts show that protein complex stability is modulated by high concentrations of cosolutes, including synthetic polymers, proteins, and cell lysates via a combination of hard-core repulsions and chemical interactions. We quantified the stability of a model protein complex, the A34F GB1 homodimer, in buffer, cells and oocytes. Read More

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DNA with zwitterionic and negatively charged phosphate modifications: Formation of DNA triplexes, duplexes and cell uptake studies.

Beilstein J Org Chem 2021 29;17:749-761. Epub 2021 Mar 29.

School of Fundamental Sciences, Massey University, Private Bag 11-222, 4442 Palmerston North, New Zealand.

Two phosphate modifications were introduced into the DNA backbone using the Staudinger reaction between the 3',5'-dinucleoside β-cyanoethyl phosphite triester formed during DNA synthesis and sulfonyl azides, 4-(azidosulfonyl)--trimethylbutan-1-aminium iodide (N+ azide) or -toluenesulfonyl (tosyl or Ts) azide, to provide either a zwitterionic phosphoramidate with N+ modification or a negatively charged phosphoramidate for Ts modification in the DNA sequence. The incorporation of these N+ and Ts modifications led to the formation of thermally stable parallel DNA triplexes, regardless of the number of modifications incorporated into the oligodeoxynucleotides (ONs). For both N+ and Ts-modified ONs, the antiparallel duplexes formed with complementary RNA were more stable than those formed with complementary DNA (except for ONs with modification in the middle of the sequence). Read More

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The structural, electronic, and optical properties of hydrofluorinated germanene (GeHF): a first-principles study.

J Mol Model 2021 Apr 6;27(5):123. Epub 2021 Apr 6.

Department of Electronics Engineering, Indian Institute of Technology (Indian School of Mines), Dhanbad, 826004, India.

The structural, electronic, and optical properties of hydrofluorinated germanene have been studied with different occupancy ratios of fluorine and hydrogen. The hybridization of H-1 s and Ge-4p orbitals in hydrogenated germanene and F-2p and Ge-4p orbitals in fluorinated germanene plays a significant role in creating an energy bandgap. The binding energy and phonon calculations confirm the stability of hydrofluorinated germanene decreases with the increase of the F to H ratio. Read More

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Thermodynamic stability, structural and electronic properties for the CAl heterofullerenes (n = 1-5): a DFT study.

J Mol Model 2021 Apr 6;27(5):124. Epub 2021 Apr 6.

Department of Chemistry, Payame Noor University, Tehran, Iran.

DFT calculations are utilized to compare and contrast the substituted aluminum-heterofullerenes, CAl (with n = 1-5) from thermodynamically view point, at density functional theory (DFT). Vibrational frequency analysis confirms that apart from CAl, all studied species are true minima. Considering the optimized geometries shows that all heterofullerenes are isolated-pentagon cage and none collapse to open deformed as segregated structure. Read More

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RCB initiates Arabidopsis thermomorphogenesis by stabilizing the thermoregulator PIF4 in the daytime.

Nat Commun 2021 04 6;12(1):2042. Epub 2021 Apr 6.

Department of Botany and Plant Sciences, Institute for Integrative Genome Biology, University of California, Riverside, CA, USA.

Daytime warm temperature elicits thermomorphogenesis in Arabidopsis by stabilizing the central thermoregulator PHYTOCHROME INTERACTING transcription FACTOR 4 (PIF4), whose degradation is otherwise promoted by the photoreceptor and thermosensor phytochrome B. PIF4 stabilization in the light requires a transcriptional activator, HEMERA (HMR), and is abrogated when HMR's transactivation activity is impaired in hmr-22. Here, we report the identification of a hmr-22 suppressor mutant, rcb-101, which surprisingly carries an A275V mutation in REGULATOR OF CHLOROPLAST BIOGENESIS (RCB). Read More

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Nearest-neighbour transition-state analysis for nucleic acid kinetics.

Nucleic Acids Res 2021 Apr 6. Epub 2021 Apr 6.

Department of Pathology, University of Utah, Salt Lake City, UT 84132, USA.

We used stopped-flow to monitor hypochromicity for 43 oligonucleotide duplexes to study nucleic acid kinetics and extract transition-state parameters for association and dissociation. Reactions were performed in 1.0 M NaCl (for literature comparisons) and 2. Read More

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Exploration of structural, thermal stability and band-gap tunability of organic and inorganic mixed cation (MA)1-xCsxPbBr3 perovskite harvester via ultrasonication synthesis route.

J Phys Condens Matter 2021 Apr 6. Epub 2021 Apr 6.

Physics, Dr Hari Singh Gour University, Sagar, Sagar, Madhya Pradesh, 470003, INDIA.

Extensive investigation over the last few years has been done on Halide based perovskite light harvester due to higher power conversion efficiency (PCE) but the thermal stability with organic cation i.e. MA is challenging for the commercialization. Read More

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Thiol-methyl-modified magnetic microspheres for effective cadmium (II) removal from polluted water.

Environ Sci Pollut Res Int 2021 Apr 6. Epub 2021 Apr 6.

School of Environmental Studies, China University of Geosciences, Wuhan, 430074, China.

For effective removal of cadmium (II) (Cd(II)) from polluted water, a magnetic adsorbent of FeO@SiO core-shell microspheres modified with methyl-protected thiol groups (FeO@SiO-SH-Protected) was synthesized and characterized by scanning electron, transmission electron, energy dispersive X-ray spectroscopy, Fourier transform infrared spectroscopies, as well as X-ray diffraction, Raman spectroscopy, and magnetic measurements. Characterization results showed that thiol groups on the surface of FeO@SiO material were protected to avoid disulfide formation. Batch adsorption experiments were conducted by varying the contact time, initial pH, solid-liquid ratio, temperature, Cd(II) concentrations, and interfering cations. Read More

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Factors determining the metal ion binding ability and selectivity of hydroxamate based compounds.

Curr Med Chem 2021 Apr 5. Epub 2021 Apr 5.

Department of Inorganic and Analytical Chemistry, Faculty of Science and Technology, University of Debrecen, Debrecen. Hungary.

There has been a long tradition for a broad spectrum of applications of both natural and synthetic hydroxamic acids and derivatives. Even nowadays, a huge number of newly designed representatives (from different monohydroxamate-based compounds to siderophore conjugates) are intended to develop potential drug candidates with desired activities. Since these compounds are effective metal-chelating agents their biological roles and actions as well as their various applications e. Read More

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Dual-mode auto-calibrating resistance thermometer: A novel approach with Johnson noise thermometry.

D Drung C Krause

Rev Sci Instrum 2021 Mar;92(3):034901

Physikalisch-Technische Bundesanstalt (PTB), Abbestraße 2-12, 10587 Berlin, Germany.

A dual-mode auto-calibrating resistance thermometer (DART) is presented. The novel DART concept combines in one instrument the fast and accurate resistance thermometry with the primary method of Johnson noise thermometry. Unlike previous approaches, the new thermometer measures the spectral density of the thermal noise in the sensing resistor directly in a sequential measurement procedure without using correlation techniques. Read More

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A physicochemical, thermodynamical, structural and computational evaluation of kynurenic acid/cyclodextrin complexes.

Food Chem 2021 Mar 23;356:129639. Epub 2021 Mar 23.

Dip. Di Chimica, Università di Torino, via P. Giuria 7, 10125 Torino, Italy.

In this work, the interaction between Kynurenic acid (KYNA) and several natural and modified cyclodextrins (CDs) is carried out. Among all the CD tested, HPβ-CD showed the strongest complexation constant (K), with a value of 270.94 ± 29. Read More

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Advances in laccase-triggered anabolism for biotechnology applications.

Crit Rev Biotechnol 2021 Apr 4:1-25. Epub 2021 Apr 4.

College of Agricultural and Environmental Sciences, Department of Crop and Soil Sciences, University of Georgia, Griffin, GA, USA.

This is the first comprehensive overview of laccase-triggered anabolism from fundamental theory to biotechnology applications. Laccase is a typical biological oxidordeuctase that induces the one-electronic transfer of diverse substrates for engendering four phenoxy radicals with concomitant reduction of O into 2HO. , laccase can participate in anabolic processes to create multifarious functional biopolymers such as fungal pigments, plant lignins, and insect cuticles, using mono/polyphenols and their derivatives as enzymatic substrates, and is thus conducive to biological tissue morphogenesis and global carbon storage. Read More

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Theoretical Study on P-coordinated Metal Atoms Embedded in Arsenene for the Conversion of Nitrogen to Ammonia.

ACS Omega 2021 Mar 16;6(12):8662-8671. Epub 2021 Mar 16.

School of Materials Science & Engineering, Jiangsu University, Zhenjiang 212013, China.

The conversion of gaseous N to ammonia under mild conditions by artificial methods has become one of the hot topics and challenges in the field of energy research today. Accordingly, based on density function theory calculations, we comprehensively explored the d-block of metal atoms (Ti, V, Cr, Mn, Fe, Co, Ni, Nb, Mo, Ru, Rh, W, and Pt) embedded in arsenene (Ars) for different transition systems of phosphorus (P) coordination as potential electrocatalysts for N reduction reaction (NRR). By adopting a "two-step" strategy with stringent NRR catalyst screening criteria, we eventually selected Nb@P-Ars as a research object for a further in-depth NRR mechanism study. Read More

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Metastable Nanobubbles.

ACS Omega 2021 Mar 16;6(12):8021-8027. Epub 2021 Mar 16.

VTT Technical Research Centre of Finland, P.O. Box 1000, 02044 VTT Espoo, Finland.

Water containing suspended nanobubbles is utilized in various applications. The observed lifetime of suspended nanobubbles is several weeks, whereas, according to the classical theory of bubble stability, a nanosized bubble should dissolve within microseconds. Explanations for the longevity of nanosized bubbles have been proposed but none of them has gained general acceptance. Read More

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Insight Into Seeded Tau Fibril Growth From Molecular Dynamics Simulation of the Alzheimer's Disease Protofibril Core.

Front Mol Biosci 2021 19;8:624302. Epub 2021 Mar 19.

Department of Chemistry, Western Washington University, Bellingham, WA, United States.

Aggregates of the microtubule associated tau protein are a major constituent of neurofibrillary lesions that define Alzheimer's disease (AD) pathology. Increasing experimental evidence suggests that the spread of tau neurofibrillary tangles results from a prion-like seeding mechanism in which small oligomeric tau fibrils template the conversion of native, intrinsically disordered, tau proteins into their pathological form. By using atomistic molecular dynamics (MD) simulations, we investigate the stability and dissociation thermodynamics of high-resolution cryo-electron microscopy (cryo-EM) structures of both the AD paired-helical filament (PHF) and straight filament (SF). Read More

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Alkali assisted hydrophobic reinforcement of coconut fiber for enhanced removal of cationic dyes: equilibrium, kinetics, and thermodynamic insight.

Int J Phytoremediation 2021 Apr 4:1-9. Epub 2021 Apr 4.

Department of Chemistry, Central University of Jharkhand, Ranchi, India.

The present study illustrates enhanced removal of methylene blue (MB) and malachite green (MG) from water using alkali-activated coconut fiber (ACF) as adsorbent. Alkali activation effectively reduces the lignocellulosic components present within coco-fiber which in turn reinforces the coco-fiber to become more water-stable. The material was characterized by FTIR, SEM-EDS, BET, XRD, and pH. Read More

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Preparation and Evaluation of Azelaic Acid Topical Microemulsion Formulation: In Vitro and In Vivo Study.

Pharmaceutics 2021 Mar 19;13(3). Epub 2021 Mar 19.

School of Pharmacy, College of Pharmacy, Kaohsiung Medical University, Kaohsiung City 80708, Taiwan.

The aim of this study was to design oil in water (O/W) microemulsion formulations for the topical administration of azelaic acid. The permeability of azelaic acid through rat skin and the anti-inflammatory activities of the formulations were conducted to examine the efficacy of the designed formulations. Skin irritation and stability tests were also performed. Read More

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Pressure and Chemical Unfolding of an α-Helical Bundle Protein: The GH2 Domain of the Protein Adaptor GIPC1.

Int J Mol Sci 2021 Mar 30;22(7). Epub 2021 Mar 30.

Centre de Biologie Structurale INSERM U1054, CNRS UMR 5048, Université de Montpellier, 34090 Montpellier, France.

When combined with NMR spectroscopy, high hydrostatic pressure is an alternative perturbation method used to destabilize globular proteins that has proven to be particularly well suited for exploring the unfolding energy landscape of small single-domain proteins. To date, investigations of the unfolding landscape of all-β or mixed-α/β protein scaffolds are well documented, whereas such data are lacking for all-α protein domains. Here we report the NMR study of the unfolding pathways of GIPC1-GH2, a small α-helical bundle domain made of four antiparallel α-helices. Read More

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Effects of Adenine Methylation on the Structure and Thermodynamic Stability of a DNA Minidumbbell.

Int J Mol Sci 2021 Mar 31;22(7). Epub 2021 Mar 31.

MOE International Joint Research Laboratory on Synthetic Biology and Medicines, School of Biology and Biological Engineering, South China University of Technology, Guangzhou 510006, China.

DNA methylation is a prevalent regulatory modification in prokaryotes and eukaryotes. -methyladenine (mA) and -methyladenine (mA) have been found to be capable of altering DNA structures via disturbing Watson-Crick base pairing. However, little has been known about their influences on non-B DNA structures, which are associated with genetic instabilities. Read More

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