Search Our Scientific Publications & Authors

Nanotechnology 2021 Jun 24. Epub 2021 Jun 24.

Instituto de Fisica, Universidade Federal do Rio de Janeiro, Bloco A Centro de Tecnologia, Av. Athos da Silveira Ramos, 149 - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro - RJ, Rio de Janeiro, 21941-909, BRAZIL.

In this work, we study theoretically the structural, electronic and transport properties of oxidized stanene using a combination of density functional theory (DFT), quantum molecular dynamics and the Landauer-Buttiker theory for the ballistic transport. Our results clearly show that oxygen adsorb onto stanene surface in both molecular or atomic forms, thus causing considerable modifications to its electronic structure and transport properties. Nevertheless, our quantum conductance calculations reveal that, in spite of oxidation, stanene still remains a good conductor that might be applied as field effect transistors, gas sensors and other devices. Read More

Prog Neurobiol 2021 Jun 21:102111. Epub 2021 Jun 21.

School of Health and Biomedical Sciences, RMIT University, Bundoora, VIC, Australia. Electronic address:

The evolution of the folded cortical surface is an iconic feature of the human brain shared by a subset of mammals and considered pivotal for the emergence of higher-order cognitive functions. While our understanding of the neurodevelopmental processes involved in corticogenesis has greatly advanced over the past 70 years of brain research, the fundamental mechanisms that result in gyrification, along with its originating cytoarchitectural location, remain largely unknown. This review brings together numerous approaches to this basic neurodevelopmental problem, constructing a narrative of how various models, techniques and tools have been applied to the study of gyrification thus far. Read More

IEEE Trans Nanobioscience 2021 Jun 24;PP. Epub 2021 Jun 24.

The process of disinfection of wastewater must use friendly materials with the environment that achieve the inhibition of bacterial growth, aiming to improve the quality of the water. In this study, electrospun nanocomposites CS (chitosan)/AgNPs (silver nanoparticles) was developed for wastewater disinfection through filtration. First, AgNPs were synthesized by a green synthesis method using aloe vera (Aloe Barbadensis Miller) extract as a reducing agent, and AgNO3 as metal precursor. Read More

J Chem Theory Comput 2021 Jun 24. Epub 2021 Jun 24.

Department of Chemistry and Biochemistry, University of California, Santa Barbara, California 93106, United States.

The self-consistent coupled-perturbed (SC-CP) method in the CRYSTAL program has been adapted to obtain electromagnetic optical rotation properties of chiral periodic systems based on the calculation of the magnetic moment induced by the electric field. Toward that end, an expression for the magnetic transition moment is developed, which involves an appropriate electronic angular momentum operator. This operator is forced to be hermitian so that the chiroptical properties are real. Read More

J Phys Chem B 2021 Jun 24. Epub 2021 Jun 24.

Department of Chemistry, the Research Institute of Natural Sciences, Sookmyung Women's University, Cheongpa-ro 47-gil 100, Yongsan-ku, Seoul 04310, Korea.

The native structure of a protein is stabilized by a number of interactions such as main-chain hydrogen bonds and side-chain hydrophobic contacts. However, it has been challenging to determine how these interactions contribute to protein stability at single amino acid resolution. Here, we quantified site-specific thermodynamic stability at the molecular level to extend our understanding of the stabilizing forces in protein folding. Read More

J Phys Chem B 2021 Jun 24. Epub 2021 Jun 24.

Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.

The presence and adsorption of particles at the oil/water interface play a critical role in stabilizing Pickering emulsions and affecting their bulk behavior. For water-in-oil (W/O) and oil-in-water (O/W) Pickering emulsions with pH-responsive nanoparticles, their interaction forces and stabilization mechanisms at the nanoscale have not been reported. Herein, the Pickering emulsions formed by oil/water mixtures under different pH values with bilayer oleic acid-coated FeO nanoparticles ([email protected] NPs) were characterized using microscopy imaging and zeta potential and interfacial tension (IFT) measurements. Read More

ACS Appl Mater Interfaces 2021 Jun 24. Epub 2021 Jun 24.

CNR-IMM, Strada VIII, 5 95121, Catania, Italy.

Gold-assisted mechanical exfoliation currently represents a promising method to separate ultralarge (centimeter scale) transition metal dichalcogenide (TMD) monolayers (1L) with excellent electronic and optical properties from the parent van der Waals (vdW) crystals. The strong interaction between Au and chalcogen atoms is key to achieving this nearly perfect 1L exfoliation yield. On the other hand, it may significantly affect the doping and strain of 1L TMDs in contact with Au. Read More

Adv Sci (Weinh) 2021 Jun 16;8(12):e2004214. Epub 2021 Mar 16.

Quantum Matter Group, MIT, Cambridge, MA, 02139, USA.

Machine learning has demonstrated great power in materials design, discovery, and property prediction. However, despite the success of machine learning in predicting discrete properties, challenges remain for continuous property prediction. The challenge is aggravated in crystalline solids due to crystallographic symmetry considerations and data scarcity. Read More

Nanotechnology 2021 Jun 23;32(37). Epub 2021 Jun 23.

Nanoscale Sciences Department, Sandia National Laboratories, Albuquerque, NM 87185, United States of America.

The high theoretical lithium storage capacity of Sn makes it an enticing anode material for Li-ion batteries (LIBs); however, its large volumetric expansion during Li-Sn alloying must be addressed. Combining Sn with metals that are electrochemically inactive to lithium leads to intermetallics that can alleviate volumetric expansion issues and still enable high capacity. Here, we present the cycling behavior of a nanostructured MnSnintermetallic used in LIBs. Read More

Environ Sci Technol 2021 Jun 24. Epub 2021 Jun 24.

State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing 100085, China.

FeO-based catalysts have promising potential in the selective catalytic reduction (SCR) of NO with NH with the advantages of environmental friendliness, excellent medium-high SCR activity, good N selectivity, and high SO tolerance. However, the NH-SCR mechanism over FeO-based catalysts remains highly uncertain and controversial due to the complex nature of the SCR reaction. Herein, the NH-SCR reaction pathways over the α-FeO(012) surface are elucidated at the atomic level by density functional theory calculations and experimental measurements. Read More

J Chem Theory Comput 2021 Jun 24. Epub 2021 Jun 24.

Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, California 90095-1569, United States.

The pH-dependence of enzyme fold stability and catalytic activity is a fundamentally dynamic, structural property which is difficult to study. The challenges and expense of investigating dynamic, atomic scale behavior experimentally means that computational methods, particularly constant pH molecular dynamics (CpHMD), are well situated tools for this. However, these methods often struggle with affordable sampling of sufficiently long time scales while also obtaining accurate p prediction and verifying the structures they generate. Read More

Chem Commun (Camb) 2021 Jun 24. Epub 2021 Jun 24.

College of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450052, P. R. China. and Henan Institute of Advanced Technology, Zhengzhou University, Zhengzhou, 450052, P. R. China.

Developing suitable supports to maximize the atomic utilization efficiency of platinum group metals is of great significance to hydrogen evolution from water splitting. Herein, we report a fully exposed Pt cluster supported on an S-vacancy rich MoS2-x support (Pt/Sv-MoS2-x) by a facile impregnation method. Pt/Sv-MoS2-x exhibits an outstanding electrochemical HER performance with a low overpotential of 26. Read More

Radiat Prot Dosimetry 2021 Jun 23. Epub 2021 Jun 23.

Graduate School of Analytical Science and Technology, Chungnam National University, 99 Daehak-ro, Yuseong-gu, Daejeon 34134, Republic of Korea.

The Urine Analysis Laboratory of the Korea Atomic Energy Research Institute has developed an in vitro method for measuring uranium in spot urine samples using inductively coupled plasma-mass spectrometry (ICP-MS) with microwave-assisted digestion and standard addition. To validate this procedure, the frozen human urine standard reference material (SRM 2668), such as uranium and creatinine, were analyzed. To overcome the matrix effect and thereby obtain precise measurement data, the standard addition method with extrapolation of four additional points was applied. Read More

Anal Methods 2021 Jun 24. Epub 2021 Jun 24.

P S Analytical Ltd, Arthur House, Crayfields Industrial Park, Main Road, Orpington, BR5 3HP, UK.

Correct handling and preservation of water samples is crucial to ensure their integrity for arsenic speciation measurements. ISO TS 19620:2018 is a method for the determination of arsenic(iii) and arsenic(v) species in waters by liquid chromatography (LC) coupled to inductively coupled plasma mass spectrometry (ICP-MS) or hydride generation atomic fluorescence spectrometry (HG-AFS). During the development of this method, a study was performed to establish the best practices for storage and preservation of samples to maintain the integrity of the arsenic speciation and stability. Read More

ACS Photonics 2021 Jun 20;8(6):1863-1872. Epub 2021 May 20.

Laboratory of Quantum and Nano-Optics and Institute of Physics, École Polytechnique Fédérale de Lausanne, CH-1015 Lausanne, Switzerland.

Immense field enhancement and nanoscale confinement of light are possible within nanoparticle-on-mirror (NPoM) plasmonic resonators, which enable novel optically activated physical and chemical phenomena and render these nanocavities greatly sensitive to minute structural changes, down to the atomic scale. Although a few of these structural parameters, primarily linked to the nanoparticle and the mirror morphology, have been identified, the impact of molecular assembly and organization of the spacer layer between them has often been left uncharacterized. Here, we experimentally investigate how the complex and reconfigurable nature of a thiol-based self-assembled monolayer (SAM) adsorbed on the mirror surface impacts the optical properties of the NPoMs. Read More

Acta Crystallogr E Crystallogr Commun 2021 Jun 14;77(Pt 6):634-637. Epub 2021 May 14.

Crystal Growth Facility, Institute of Physics, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland.

The crystal structure of Ba(IO), penta-barium bis-(orthoperiodate), has been re-investigated at room temperature based on single-crystal X-ray diffraction data. In comparison with a previous crystal structure determination by the Rietveld method, an improved precision of the structural parameters was achieved. Additionally, low-temperature measurements allowed the crystal structure evolution to be studied down to 80 K. Read More

Acta Crystallogr E Crystallogr Commun 2021 Jun 7;77(Pt 6):588-591. Epub 2021 May 7.

Department of Chemistry, Oregon State University, Corvallis, Oregon 97331, USA.

The crystal structure of magnesium zinc divanadate, MgZnVO, was determined and refined from laboratory X-ray powder diffraction data. The title compound was synthesized by a solid-state reaction at 1023 K in air. The crystal structure is isotypic with MnZnVO (/; = 6) and is related to the crystal structure of thortveitite. Read More

J Tissue Eng 2021 Jan-Dec;12:20417314211017417. Epub 2021 Jun 6.

Center for Regenerative Medicine, Abigail Wexner Research Institute, Nationwide Children's Hospital, Columbus, OH, USA.

Decellularized tracheal scaffolds offer a potential solution for the repair of long-segment tracheal defects. However, complete decellularization of trachea is complicated by tracheal collapse. We created a partially decellularized tracheal scaffold (DTS) and characterized regeneration in a mouse model of tracheal transplantation. Read More

Chem Sci 2021 Jan 5;12(9):3290-3294. Epub 2021 Jan 5.

School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210093 China

With atomically precise gold nanoclusters acting as a starting unit, substituting one or more gold atoms of the nanocluster with other metals has become an effective strategy to create metal synergy for improving catalytic performances and other properties. However, so far detailed insight into how to design the gold-based nanoclusters to optimize the synergy is still lacking, as atomic-level exchange between the surface-gold (or core-gold) and the incoming heteroatoms is quite challenging without changing other parts. Here we report a Cd-driven reconstruction of Au(DMBT) (DMBT = 3,5-dimethylbenzenethiol), in which four Au(DMBT) staples are precisely replaced by two AuCd(DMBT) staples to form AuCd(DMBT) with the face-centered cubic inner core retained. Read More

Chem Sci 2020 Dec 23;12(8):2876-2884. Epub 2020 Dec 23.

Department of Chemistry, University of British Columbia Vancouver BC V6T 1Z1 Canada

Top7 is a designed protein with atomic level accuracy and shows a folded structure not found in nature. Previous studies showed that the folding of Top7 is not cooperative and involves various folding intermediate states. In addition, various fragments of Top7 were found to fold on their own in isolation. Read More

Chem Sci 2021 Jan 4;12(7):2655-2666. Epub 2021 Jan 4.

Department of Chemistry, University of Manitoba Winnipeg Manitoba R3T 2N2 Canada

Ac-based radiopharmaceuticals have the potential to become invaluable in designated cancer therapy. However, the limited understanding of the solution chemistry and bonding properties of actinium has hindered the development of existing and emerging targeted radiotherapeutics, which also poses a significant challenge in the discovery of new agents. Herein, we report the geometric and electronic structural properties of hydrated Ac cations in the [Ac(HO) ] ( = 4-11) complexes in aqueous solution and gas-phase using density functional theory. Read More

Chem Sci 2021 Jan 28;12(7):2397-2403. Epub 2021 Jan 28.

Department of Chemical Science, Life Science and Environmental Sustainability, University of Parma Parma Italy.

Trends in atomic properties are well-established tools for guiding the analysis and discovery of materials. Here, we show how compression can reveal a long sought-after connection between two central chemical concepts - van-der-Waals (vdW) radii and electronegativity - and how these relate to the driving forces behind chemical and physical transformations. Read More

Chem Sci 2020 Dec 22;12(7):2368-2380. Epub 2020 Dec 22.

Key Laboratory of Materials Physics, Anhui Key Laboratory of Nanomaterials and Nanostructures, Institute of Solid State Physics, Chinese Academy of Sciences Hefei 230031 P. R. China

Gold nanoparticles are probably the nanoparticles that have been best studied for the longest time due to their stability, physicochemical properties and applications. Controlling gold nanoparticles with atomic precision is of significance for subsequent research on their structures, properties and applications, which is a dream that has been pursued for many years since ruby gold was first obtained by Faraday in 1857. Fortunately, this dream has recently been partially realized for some ultrasmall gold nanoparticles (nanoclusters). Read More

Chem Sci 2020 Dec 11;12(6):2078-2090. Epub 2020 Dec 11.

Laboratory of Computational Science and Modeling, IMX, École Polytechnique Fédérale de Lausanne 1015 Lausanne Switzerland

Electronic nearsightedness is one of the fundamental principles that governs the behavior of condensed matter and supports its description in terms of local entities such as chemical bonds. Locality also underlies the tremendous success of machine-learning schemes that predict quantum mechanical observables - such as the cohesive energy, the electron density, or a variety of response properties - as a sum of atom-centred contributions, based on a short-range representation of atomic environments. One of the main shortcomings of these approaches is their inability to capture physical effects ranging from electrostatic interactions to quantum delocalization, which have a long-range nature. Read More

Chem Sci 2020 Dec 8;12(5):1730-1735. Epub 2020 Dec 8.

Department of Physics, Chemistry and Biology (IFM), Linköping University Linköping SE-581 83 Sweden

Although lead-free halide double perovskites are considered as promising alternatives to lead halide perovskites for optoelectronic applications, state-of-the-art double perovskites are limited by their large bandgap. The doping/alloying strategy, key to bandgap engineering in traditional semiconductors, has also been employed to tune the bandgap of halide double perovskites. However, this strategy has yet to generate new double perovskites with suitable bandgaps for practical applications, partially due to the lack of fundamental understanding of how the doping/alloying affects the atomic-level structure. Read More

Chem Sci 2021 Jan 12;12(5):1656-1660. Epub 2021 Jan 12.

Department of Biomolecular Engineering, Graduate School of Engineering, Nagoya University Furo-cho, Chikusa-ku Nagoya 464-8603 Japan

Herein we report an amplification system of helical excess triggered by nucleic acid hybridization for the first time. It is usually impossible to prepare achiral nanostructures composed of nucleic acids because of their intrinsic chirality. We used serinol nucleic acid (SNA) oligomers for the preparation of achiral nanowires because SNA oligomers with symmetrical sequences are achiral. Read More

Chem Sci 2020 Dec 15;12(4):1206-1219. Epub 2020 Dec 15.

Department of Materials and Environmental Chemistry, Stockholm University Stockholm SE-106 91 Sweden

Porous crystalline materials such as zeolites, metal-organic frameworks (MOFs) and covalent organic frameworks (COFs) have attracted great interest due to their well-defined pore structures in molecular dimensions. Knowing the atomic structures of porous materials is crucial for understanding their properties and exploring their applications. Many porous materials are synthesized as polycrystalline powders, which are too small for structure determination by X-ray diffraction. Read More

Chem Sci 2020 Nov 13;12(3):1095-1100. Epub 2020 Nov 13.

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 Wuhan 430071 China

Thiols play critical roles in regulating biological functions and have wide applications in pharmaceutical and biomedical industries. However, we still lack a general approach for the simultaneous detection of various thiols, especially in complex systems. Herein, we establish a F NMR platform where thiols are selectively fused into a novelly designed fluorinated receptor that has two sets of environmentally different F atoms with fast kinetics ( = 0. Read More

Chem Sci 2020 Oct 23;12(2):576-589. Epub 2020 Oct 23.

Institute of Food, Nutrition and Health, ETH Zurich Schmelzbergstrasse 7 8092 Zurich Switzerland

Endolysins are bacteriophage-encoded peptidoglycan hydrolases targeting the cell wall of host bacteria their cell wall-binding domains (CBDs). The molecular basis for selective recognition of surface carbohydrate ligands by CBDs remains elusive. Here, we describe, in atomic detail, the interaction between the phage endolysin domain CBD500 and its cell wall teichoic acid (WTA) ligands. Read More

Chem Sci 2021 Jan 22;12(12):4345-4352. Epub 2021 Jan 22.

IBM Quantum, IBM Research - Zurich 8803 Rüschlikon Switzerland

The development of tailored materials for specific applications is an active field of research in chemistry, material science and drug discovery. The number of possible molecules obtainable from a set of atomic species grow exponentially with the size of the system, limiting the efficiency of classical sampling algorithms. On the other hand, quantum computers can provide an efficient solution to the sampling of the chemical compound space for the optimization of a given molecular property. Read More