157,612 results match your criteria proton


H MR spectroscopy biomarkers of neuronal and synaptic function are associated with tau deposition in cognitively unimpaired older adults.

Neurobiol Aging 2022 Jan 5;112:16-26. Epub 2022 Jan 5.

Department of Radiology, Mayo Clinic, Rochester, MN, USA. Electronic address:

Proton magnetic resonance spectroscopy (H MRS) may provide information on pathophysiological changes associated with tau deposition in cognitively unimpaired older adults. In this study, the associations of posterior cingulate gyrus tau and amyloid beta (Aβ) deposition on PET with H MRS metabolite ratios acquired from bilateral posterior cingulate gyri were investigated in cognitively unimpaired older adults. Participants (n = 40) from the Mayo Clinic Study of Aging underwent single-voxel sLASER H MRS from the posterior cingulate gyrus at 3 Tesla, F-flortaucipir, and C- Pittsburgh Compound B (PiB) PET. Read More

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January 2022

A review on lactoferrin as a proton pump inhibitor.

Int J Biol Macromol 2022 Jan 14. Epub 2022 Jan 14.

Centre of Molecular and Environmental Biology (CBMA), Department of Biology, University of Minho, 4710-057 Braga, Portugal. Electronic address:

Lactoferrin (Lf) is a versatile natural milk-derived protein that exhibits multiple interesting biological activities. Since it is safe for human administration and currently manufactured using low cost and well-established large-scale processes, the Lf scientific community has been devoted at dissecting its mechanisms of action towards its more rational and efficient use for various applications. Emerging literature has identified proton pumping ATPases as molecular targets of Lf in different cellular models linked to distinct activities of this natural protein. Read More

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January 2022

Preparation of functionalized pectin through acylation with alkyl gallates: Experiments coupled with density functional theory.

Int J Biol Macromol 2022 Jan 14. Epub 2022 Jan 14.

Key Laboratory of Characteristics Garden Plants Resource in Fujian and Taiwan, School of Biological Science and Biotechnology, Minnan Normal University, Zhangzhou 363000, PR China. Electronic address:

The covalent grafting of alkyl gallates onto pectin using a lipase-catalyzed reaction in a tetrahydrofuran/aqueous medium process acylated pectin molecules with excellent antioxidant and antibacterial properties. The alkyl gallates including methyl, ethyl, and propyl gallates were enzymatically grafted onto pectin molecule, in order to study the effect of alkyl gallates on the functional modification of pectin. The grafting mechanism was analyzed by ultraviolet-visible spectrum (UV-Vis), Fourier transform infrared spectrum (FTIR), proton nuclear magnetic resonance (HNMR), and density functional theory (DFT). Read More

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January 2022

Accelerated Hydrogen "Spill-Over" Enhances Anode Performance of Tensile Strained Pd-Based Fuel Cell Electrocatalysts.

Small Methods 2022 Jan 17:e2101328. Epub 2022 Jan 17.

Tianjin Key Laboratory of Advanced Functional Porous Materials and Institute for New Energy Materials and Low Carbon Technologies, School of Materials Science and Engineering, Tianjin University of Technology, Tianjin, 300384, P. R. China.

Development of efficient electrocatalysts usually relies on half-cell electrochemical tests for rapid material screening, which however are not always consistent with the associated full cell evaluation. This study designs a tensile-strained Pd anode and reveals that with a lower apparent activity toward the hydrogen oxidation reaction as compared to the unstrained one, it exhibits a surprisingly high activity in proton exchange membrane fuel cells (PEMFCs). With an ultralow Pd loading of 4. Read More

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January 2022

Water-Processable and Multiscale-Designed Vanadium Oxide Cathodes with Predominant Zn Intercalation Pseudocapacitance toward High Gravimetric/Areal/Volumetric Capacity.

Small 2022 Jan 17:e2105796. Epub 2022 Jan 17.

School of Physics and Optoelectronics, Xiangtan University, Hunan, 411105, China.

Layered vanadium oxides have great potential as cathode materials for recently surged aqueous zinc-ion batteries (AZIBs). However, achieving high energy/power densities simultaneously is challenging, and side reactions related to more frequently than disclosed Zn /proton co-insertion mechanism aggravate stability concerns. Herein, an engineered binder-free cathode configuration based on water-processable and high packing-density sheet-shaped composites of carbon nanotubes network, surface poly(3,4-ethylenedioxythiophene) (PEDOT) bridging coating, and ultrasmall PEDOT-intercalated V O nanoflakes is developed, and therein, large pseudocapacitance via predominant (≈91%) Zn intercalation is revealed. Read More

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January 2022

Association of preterm birth with medications: machine learning analysis using national health insurance data.

Arch Gynecol Obstet 2022 Jan 17. Epub 2022 Jan 17.

Department of Obstetrics and Gynecology, Korea University Anam Hospital, 73 Goryeodae-ro, Seongbuk-gu, Seoul, 02841, Korea.

Purpose: To use machine learning and population data for testing the associations of preterm birth with socioeconomic status, gastroesophageal reflux disease (GERD) and medication history including proton pump inhibitors, sleeping pills and antidepressants.

Methods: Population-based retrospective cohort data came from Korea National Health Insurance Service claims data for all women who aged 25-40 years and gave births for the first time as singleton pregnancy during 2015-2017 (405,586 women). The dependent variable was preterm birth during 2015-2017 and 65 independent variables were included (demographic/socioeconomic determinants, disease information, medication history, obstetric information). Read More

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January 2022

The degradation effect on proton dissociation and transfer in perfluorosulfonic acid membranes.

Phys Chem Chem Phys 2022 Jan 17. Epub 2022 Jan 17.

School of Energy Science and Engineering, Harbin Institute of Technology, Harbin, 150001, China.

In the operation of proton exchange membrane fuel cells (PEMFCs), the ionomer-perfluorosulfonic acid (PSFA) membrane side chains are easily attacked by free radicals, resulting in membrane degradation. In this work, the chemical degradation effect of side chains in the PSFA membrane on proton dissociation and transfer behaviors is investigated by means of the quantum chemistry calculation. The rotation of the H atom in the acid group after the degradation is evaluated. Read More

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January 2022

assessment of DNA damage response gene variants associated with head and neck cancer.

J Biomol Struct Dyn 2022 Jan 17:1-18. Epub 2022 Jan 17.

Department of Biotechnology, Assam University, Silchar, India.

Head and neck cancer (HNC), the sixth most common cancer globally, stands first in India, especially Northeast India, where tobacco usage is predominant, which introduces various carcinogens leading to malignancies by accumulating DNA damages. Consequently, the present work aimed to predict the impact of significant germline variants in DNA repair and Tumour Suppressor genes on HNC development. WES in Ion Proton platform on 'discovery set' ( = 15), followed by recurrence assessment of the observed variants on 'confirmation set' ( = 40) using Sanger Sequencing was performed on the HNC-prevalent NE Indian populations. Read More

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January 2022

Prevention of nNon-Vitamin K Oral Anticoagulants-Related Gastrointestinal Bleeding With Acid Suppressants: A Systematic Review and Meta-Analysis.

Clin Appl Thromb Hemost 2022 Jan-Dec;28:10760296211064897

585250The Second Affiliated Hospital of Chongqing Medical University, Chongqing, China.

Whether the use of acid suppressants can reduce non-vitamin K oral anticoagulants (NOACs)-related gastrointestinal bleeding (GIB) remains unclear. To systemically evaluate the effect of acid suppressants on the risk of GIB in patients treated with NOACs. All related studies were searched in four databases (Cochrane, Embase, PubMed, and Web of Science) from their establishment to August 10, 2021. Read More

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January 2022

Coherent Two-Dimensional and Broadband Electronic Spectroscopies.

Chem Rev 2022 Jan 17. Epub 2022 Jan 17.

Department of Chemistry, Princeton University, Princeton, New Jersey 08 544, United States.

Over the past few decades, coherent broadband spectroscopy has been widely used to improve our understanding of ultrafast processes (e.g., photoinduced electron transfer, proton transfer, and proton-coupled electron transfer reactions) at femtosecond resolution. Read More

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January 2022

Interlink among catalyst loading, transport and performance of proton exchange membrane fuel cells: a pore-scale study.

Nanoscale Horiz 2022 Jan 17. Epub 2022 Jan 17.

State Key Laboratory of Engines, Tianjin University, Tianjin 300350, China.

An optimum balance between performance and Pt loading is critically important for the commercialization of proton exchange membrane (PEM) fuel cells. This research aims to investigate the interlink among Pt loading, reactive transport, and performance. An advanced pore-scale model is developed to describe the coupled reactive transport in the catalyst layer (CL) with the reactant gas, protons, and electrons all considered. Read More

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January 2022

Underestimation of Anthropogenic Bromoform Released into the Environment?

Environ Sci Technol 2022 Jan 15. Epub 2022 Jan 15.

Aix Marseille Univ, CNRS, LCE, 3 place Victor Hugo, 13003 Marseille, France.

Bromoform (CHBr) belongs to very-short-lived substances (VSLSs), which are important precursors of reactive bromine species (BrOx) contributing to tropospheric and stratospheric chemistry. To date, most models calculating bromine product emissions to the atmosphere only consider the natural production of CHBr from marine organisms such as macroalgae and phytoplankton. However, CHBr has many other anthropogenic sources (coastal industrial sites, desalination and wastewater plants, ballast waters, and seawater toilets) that may drastically increase the amounts emitted in the atmosphere. Read More

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January 2022

Aging of Volatile Organic Compounds in October 2017 Northern California Wildfire Plumes.

Environ Sci Technol 2022 Jan 16. Epub 2022 Jan 16.

Department of Environmental Science, Policy, and Management, University of California, Berkeley, Berkeley, California 94720, United States.

In the western United States, the number and severity of large wildfires have been growing for decades. Biomass burning (BB) is a major source of volatile organic compounds (VOCs) to the atmosphere both globally and regionally. Following emission, BB VOCs are oxidized while being transported downwind, producing ozone, secondary organic aerosols, and secondary hazardous VOCs. Read More

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January 2022

Heat-Induced Dry Hydrolysis of Sodium Borohydride/Oxalic Acid Dihydrate Composite for Hydrogen Production.

ACS Omega 2022 Jan 28;7(1):979-986. Epub 2021 Dec 28.

Department of Chemical Engineering, Kyonggi University, 154-42 Gwanggyosan-ro, Yeongtong-gu, Suwon-si, Gyeonggi-do 16227, Korea.

The generation of hydrogen, free of poisonous gas, combined with a lightweight proton-exchange membrane fuel cell can expand the use of hydrogen energy from conventional ground transportation vehicles and power stations to a variety of flying vehicles and wearable devices for civilian and military purposes. Herein, a hydrogen fuel composite composed of sodium borohydride (SB) and oxalic acid dihydrate (OA·2HO) is introduced. The SB/OA·2HO composite was easily decomposed to generate pure hydrogen at a trigger temperature of 50 °C, at which the water molecules of the OA·2HO component were effectively liberated, inducing hydrolysis of the SB component to produce hydrogen gas. Read More

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January 2022

Quantifying Systematic RBE-Weighted Dose Uncertainty Arising from Multiple Variable RBE Models in Organ at Risk.

Adv Radiat Oncol 2022 Mar-Apr;7(2):100844. Epub 2021 Nov 11.

Division of Radiation Oncology, National Cancer Centre Singapore, Singapore.

Purpose: Relative biological effectiveness (RBE) uncertainties have been a concern for treatment planning in proton therapy, particularly for treatment sites that are near organs at risk (OARs). In such a clinical situation, the utilization of variable RBE models is preferred over constant RBE model of 1.1. Read More

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November 2021

Impact of Warhead Modulations on the Covalent Inhibition of SARS-CoV-2 M Explored by QM/MM Simulations.

ACS Catal 2022 Jan 26;12(1):698-708. Epub 2021 Dec 26.

BioComp Group, Institute of Advanced Materials (INAM), Universitat Jaume I, 12071 Castelló, Spain.

The COVID-19 pandemic, caused by the severe acute respiratory syndrome coronavirus-2, SARS-CoV-2, shows the need for effective antiviral treatments. Here, we present a simulation study of the inhibition of the SARS-CoV-2 main protease (M), a cysteine hydrolase essential for the life cycle of the virus. The free energy landscape for the mechanism of the inhibition process is explored by QM/MM umbrella sampling and free energy perturbation simulations at the M06-2X/MM level of theory for two proposed peptidyl covalent inhibitors that share the same recognition motif but feature distinct cysteine-targeting warheads. Read More

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January 2022

Biophysical Reviews' "Meet the Councilor Series"-a profile of Peter Pohl.

Authors:
Peter Pohl

Biophys Rev 2021 Dec 23;13(6):839-844. Epub 2021 Nov 23.

Institute of Biophysics, Johannes Kepler University, Linz, Austria.

It is my pleasure to write a few words to introduce myself to the readers of as part of the "Meet the Councilor Series." Currently, I am serving the second period as IUPAB councilor after having been elected first in 2017. Initially, I studied Biophysics in Moscow (Russia) and later Medicine in Halle (Germany). Read More

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December 2021

SHORT COMMUNICATION-Inappropriate use of proton pump inhibitor for stress ulcer prophylaxis in a tertiary care hospital in Karachi, Pakistan.

Pak J Pharm Sci 2021 Nov;34(6):2253-2255

Department of Medicine, Faculty Office Building, The Aga Khan University Hospital, Karachi, Pakistan.

The use of proton pump inhibitors (PPI) has been expanded inappropriately. PPI are among the most selling drugs in the world. There is growing evidence that PPI are associated with significant adverse effects along with undue financial burden. Read More

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November 2021

Tripartite hormonal regulation of plasma membrane H-ATPase activity.

Trends Plant Sci 2022 Jan 13. Epub 2022 Jan 13.

Instituto de Biología Molecular y Celular de Plantas, Consejo Superior de Investigaciones Cientificas, Universidad Politecnica de Valencia, ES-46022, Valencia, Spain. Electronic address:

The enzyme activity of the plasma membrane (PM) proton pump, well known as arabidopsis PM H-ATPase (AHA) in the model plant arabidopsis (Arabidopsis thaliana), is controlled by phosphorylation. Three different classes of phytohormones, brassinosteroids (BRs), abscisic acid (ABA), and auxin regulate plant growth and responses to environmental stimuli, at least in part by modulating the activity of the pump through phosphorylation of the penultimate Thr residue in its carboxyl terminus. Here, we review the current knowledge regarding this tripartite hormonal AHA regulation and highlight mechanisms of activation and deactivation, as well as the significance of hormonal crosstalk. Read More

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January 2022

Mechanisms of long-distance allosteric couplings in proton-binding membrane transporters.

Adv Protein Chem Struct Biol 2022 5;128:199-239. Epub 2022 Jan 5.

University of Bucharest, Faculty of Physics, Măgurele, Romania; Forschungszentrum Jülich, Institute of Computational Biomedicine, Jülich, Germany. Electronic address:

Membrane transporters that use proton binding and proton transfer for function couple local protonation change with changes in protein conformation and water dynamics. Changes of protein conformation might be required to allow transient formation of hydrogen-bond networks that bridge proton donor and acceptor pairs separated by long distances. Inter-helical hydrogen-bond networks adjust rapidly to protonation change, and ensure rapid response of the protein structure and dynamics. Read More

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January 2022

Theoretical study on the radical scavenging activity and mechanism of four kinds of Gnetin molecule.

Food Chem 2021 Dec 29;378:131975. Epub 2021 Dec 29.

College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China; State Key Laboratory of Chemical Oncogenomics, Peking University Shenzhen Graduate School, Shenzhen 518055, P. R. China.

As an important subgroup of resveratrol oligomers, Gnetins received much attention due to their antioxidants. The four Gnetin molecules are divided into two major categories according to different structures, type-A (Gnetin-C, Gnetin-D) and type-B (Gnetin-L, Gnetin-F). Density functional theory (DFT) has been performed thermodynamically and kinetically in detail to analyze the structure and antioxidant activity of four Gnetins toward OH/OOH radical in the gas and solvents phase with four possible antioxidant mechanisms, namely, Hydrogen-atom transfer (HAT), Single electron transfer followed by proton transfer (SET-PT), Sequential proton-loss electron transfer (SPLET), and Radical adduct formation (RAF). Read More

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December 2021

Diminazene aceturate, an angiotensin converting enzyme 2 (ACE2) activator, promotes cardioprotection in ischemia/reperfusion-induced cardiac injury.

Peptides 2022 Jan 13:170746. Epub 2022 Jan 13.

Department of Morphology, Federal University of Minas Gerais, Brazil. Electronic address:

This study aimed to investigate whether the Diminazene Aceturate (DIZE), an angiotensin-converting enzyme 2 (ACE2) activator, can revert cardiac dysfunction in ischemia reperfusion-induced (I/R) injury in animals and examine the mechanism underlying this effect. Wistar rats systemically received DIZE (1 mg/kg) for thirty days. Cardiac function in isolated rat hearts was evaluated using the Langendorff technique. Read More

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January 2022

Structural basis for blocked excited state proton transfer in a fluorescent, photoacidic non-canonical amino acid-containing antibody fragment.

J Mol Biol 2022 Jan 13:167455. Epub 2022 Jan 13.

The Biodesign Center for Molecular Design and Biomimetics, Arizona State University, Tempe, Arizona, USA; The School of Molecular Sciences, Arizona State University, Tempe, Arizona, USA.

The fluorescent non-canonical amino acid (fNCAA) L-(7-hydroxycoumarin-4-yl)ethylglycine (7-HCAA) contains a photoacidic 7-hydroxycoumarin (7-HC) side chain whose fluorescence properties can be tuned by its environment. In proteins, many alterations to 7-HCAA's fluorescence spectra have been reported including increases and decreases in intensity and red- and blue-shifted emission maxima. The ability to rationally design protein environments that alter 7-HCAA's fluorescence properties in predictable ways could lead to novel protein-based sensors of biological function. Read More

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January 2022

Sensitive screening of methamphetamine stimulant using potential-modulated electrochemiluminescence.

Anal Chim Acta 2022 Jan 30;1191:339229. Epub 2021 Oct 30.

Department of Chemistry, Faculty of Science, Shinshu University, 3-1-1 Asahi, Matsumoto, Nagano, Japan.

Methamphetamine (MA) is one of the most commonly abused recreational stimulants; thus, rapid and sensitive screening methods for MA are of great importance in forensic analytical chemistry. In the present work, potential modulation was combined with electrochemiluminescence (ECL) for the sensitive determination of MA. The potential modulated (PM) technique involved applying a signal to electrodes by superimposing an alternating current potential on the direct current potential. Read More

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January 2022

Quantitative evaluation of key properties of dry and wet metal oxides and metal hydroxides as well as of their potential determining cations in aqueous solutions.

Authors:
Jarl B Rosenholm

Adv Colloid Interface Sci 2021 Dec 28;301:102592. Epub 2021 Dec 28.

Laboratory of Physical Chemistry, Åbo Akademi University, Aurum, Henriksgatan 2, FI-20500 Åbo (Turku), Finland. Electronic address:

When potential determining cations are dissolved from solids, it is a reversed process to precipitation of solids from their electrolyte solutions. In both cases there is a transport of substance and charges across the solid-liquid interface. It is obvious that a comprehensive understanding of the process involves characterization of the (dry) solid, of the solid-liquid interface and of the potential determining cation electrolyte. Read More

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December 2021

Modern Therapy for Spinal and Paraspinal Ewing Sarcoma: An Update of the XXX Experience.

Int J Radiat Oncol Biol Phys 2022 Jan 13. Epub 2022 Jan 13.

Department of Radiation Oncology, University of Florida College of Medicine, Jacksonville, FL.

Purpose: In 2010, we published a comprehensive review of our institutional outcomes treating children with spinal and paraspinal Ewing sarcoma using photon therapy. Multimodality therapy was associated with fair disease control but also with serious toxicity, including a 37% rate of Grade ≥3 toxicity. We therefore sought to assess our more recent experience treating children with more modern technology and treatment regimens. Read More

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January 2022

Strategies for discontinuation of proton pump inhibitors (PPIs) in patients with long-term PPI administration: a randomized controlled trial.

BMC Gastroenterol 2022 Jan 15;22(1):21. Epub 2022 Jan 15.

Department of Gastroenterology, Juntendo University School of Medicine, 2-1-1 Hongo Bunkyo-ku, Tokyo, 113-8421, Japan.

Background: Proton pump inhibitors (PPIs), including potassium ion-competitive acid blocker, are widely used worldwide and are often used for long periods of time. However, in recent years, potential side effects associated with long-term PPI use have been reported. Many patients take PPI for a long period of time, even though it is unnecessary, and it is necessary to discontinue PPI administration in such patients. Read More

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January 2022

Reduced GABA levels in the medial prefrontal cortex are associated with cognitive impairment in patients with NMOSD.

Mult Scler Relat Disord 2022 Jan 4;58:103496. Epub 2022 Jan 4.

Department of Radiology, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215000, China; Institute of Medical Imaging, Soochow University, Suzhou, Jiangsu 215000, China; National Clinical Research Center for Hematologic Diseases, The First Affiliated Hospital of Soochow University, Suzhou, Jiangsu, 215000, China. Electronic address:

Background: Cognitive impairment is a symptom present in part of patients with neuromyelitis optica spectrum disorder (NMOSD) and its pathophysiology is unknown. Dysfunction of the GABAergic/glutamatergic pathways involving inhibitory and excitatory neurotransmitters have been implicated in several neurological disorders. This study aimed to investigate the changes in inhibitory gamma-aminobutyric acid (GABA) and excitatory glutamate and glutamine (Glx) neurotransmitter levels and their correlations with cognitive functions in patients with NMOSD. Read More

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January 2022

New method for production of Tb via Dy by irradiation of Gd by medium energy alpha particles.

Nucl Med Biol 2021 Dec 30;106-107:52-61. Epub 2021 Dec 30.

National Research Center "Kurchatov Institute", 1, Akademika Kurchatova pl., Moscow 123182, Russian Federation.

Introduction: Tb (T = 5.32 d) is considered both as a promising Auger electron emitter and as a diagnostic pair for other therapeutic terbium radionuclides. Despite several methods for its production proposed, it remains scarcely available. Read More

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December 2021