Search Our Scientific Publications & Authors

Comput Biol Med 2019 Mar 26;108:20-30. Epub 2019 Mar 26.

Department of Electronic & Computer Engineering, Ngee Ann Polytechnic, Singapore; Department of Biomedical Engineering, School of Science and Technology, SIM University, Singapore; Department of Biomedical Imaging, Faculty of Medicine, University of Malaya, Kuala Lumpur, Malaysia.

Sleep is a prominent physiological activity in our daily life. Sleep apnea is the category of sleep disorder during which the breathing of the person diminishes causing the alternation in the upper airway resistance. The electrocardiogram derived respiration (EDR) and heart rate (RR-time-series) signals are normally used for the detection of sleep apnea as these two signals capture cardio-pulmonary activity information. Read More

Sci Total Environ 2019 Apr 5;673:750-755. Epub 2019 Apr 5.

Department of Civil and Environmental Engineering, KAIST, 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea. Electronic address:

A process to produce both biodiesel and alginate in an integrated manner from a brown seaweed, Laminaria japonica, was established. Mannitol, a major carbon constituent in L. japonica, served to produce neutral lipids via the heterotrophic cultivation of an oleaginous yeast, Cryptococcus sp. Read More

Spectrochim Acta A Mol Biomol Spectrosc 2019 Apr 11;218:237-242. Epub 2019 Apr 11.

Institute of Atomic and Molecular Physics, Jilin University, Changchun 130012, China. Electronic address:

The electron transfer (ET) rate in quantum dot (QD)-molecular acceptor systems is dependent upon system reorganization energy (RE, λ), which comprises contributions from solvent (λ) and reactants (λ). However, to date, the effect of λ on ET rate has been largely ignored. Herein, the ET from CdSe/ZnS QDs to 1-chloroanthraquinone (1-CAQ) in different solvents was investigated using ultrafast transient absorption spectroscopy as a means to evaluate the effect of λ on ET rate. Read More

J Environ Radioact 2019 Apr 16;204:104-110. Epub 2019 Apr 16.

Department of Oral and Maxillofacial Radiology, Tokushima University Graduate School, Japan. Electronic address:

The purpose of the study was to obtain basic data to identify problems in radiation education in a situation where confidence in nuclear power has fluctuated over time and fear of nuclear power has increased globally due to nuclear power plant disasters at Chernobyl and Fukushima. We conducted a questionnaire survey on understanding and risk perception of radiation and atomic power, before and after lectures, for 107 Japanese and 137 Indonesian dental students. Thirty-six phrases were extracted from two supplementary texts about radiation created by the Japanese Ministry of Education, Culture, Sports, Science and Technology, and 30 events commonly used in research on risk perception were used. Read More

J Phys Chem Lett 2019 Apr 19. Epub 2019 Apr 19.

Development of technologies for protection against chemical warfare agents (CWAs) is critically important. Recently, polyoxometalates have attracted attention as potential catalysts for nerve-agent decomposition. The improvement of their effectiveness in real operating conditions requires an atomic-level understanding of CWA decomposition at the gas-solid interface. Read More

Int J Med Mushrooms 2019 ;21(4):343-352

Department of Pharmaceutical Botany, Faculty of Pharmacy, Jagiellonian University Medical College, Krakow, Poland.

Zinc and indole compounds demonstrate anti-inflammatory, antidepressant, and antioxidant activity. Edible mushrooms are good sources of these substances. Therefore, in this study, we aimed to study the accumulation, release, and absorption of zinc and indole compounds from mycelial cultures of Imleria badia species using in vitro models. Read More

J Phys Chem Lett 2019 Apr 19. Epub 2019 Apr 19.

The interfaces with multi-functions for the promoted solid/solid interfacial charge transfer dynamics and the accelerated solid/electrolyte interfacial water redox reaction kinetics are determinative to the photoelectrodes achieving high performances for photoelectrochemical (PEC) water splitting. In this work, the well-designed cascading interfaces are introduced in the n-Si photoanode, which is effectively protected by an atomic layer deposited CoOx thin layer for stabilizing the n-Si photoanode and then coated with an earth-abundant NiCuOx layer for catalyzing water oxidation reaction. Furthermore, the formed n-Si/CoOx/NiCuOx triple-junction could generate a large band bending to provide a considerable photovoltage for promoting the photoinduced charge transfer and separation processes at the n-Si/CoOx/NiCuOx cascading interfaces. Read More

J Phys Chem B 2019 Apr 19. Epub 2019 Apr 19.

Crystal simulations provide useful tools, along with solution simulations, to test nucleic acid force fields, but should be interpreted with care owing to the difficulty of establishing the environmental conditions needed to reproduce experimental crystal packing. These challenges underscore the need to construct proper protocols for carrying out crystal simulations and analyzing results to identify the origin of deviations from crystallographic data. Toward this end, we introduce a novel framework for B-factor decomposition into additive intramolecular, rotational, and translational atomic fluctuation components, and partitioning of each of these components into individual asymmetric unit and lattice contributions. Read More

J Phys Chem B 2019 Apr 19. Epub 2019 Apr 19.

The structural and dynamic properties of imidazole in aqueous solution have been studied by means of classical and ab initio molecular dynamics simulations. We developed a new force field for the imidazole molecule with improved modelling of the electrostatic interactions, specifically tailored to address the well known drawbacks of existing force fields based on the atomic fractional charges approach. To this end, we reparametrized the charge distribution on the heterocyclic ring, introducing an extra site accounting for the lone pair on the deprotonated nitrogen. Read More

Environ Sci Technol 2019 Apr 19. Epub 2019 Apr 19.

Aerosol phase state is critical for quantifying aerosol effects on climate and air quality. However, significant challenges remain in our ability to predict and quantify phase state during its evolution in the atmosphere. Herein, we demonstrate that aerosol phase (liquid, semi-solid, solid) exhibits a diel cycle in a mixed forest environment, oscillating between a viscous, semi-solid phase state at night and liquid phase state with phase separation during the day. Read More

ACS Appl Mater Interfaces 2019 Apr 19. Epub 2019 Apr 19.

Developing highly efficient FeF3-based cathode materials for Na/K-ion batteries is greatly needed, which needs long cycling life and rate performance besides for large voltage and capacity. Accordingly, we designed two-dimensional (2D) FeF3 nanosheet to obtain highly efficient Na/K-ion batteries. And first-principles calculations were implemented to discuss systematically Na and K storage mechanism on FeF3 (012) nanosheet. Read More

Cogn Sci 2019 Apr;43(4):e12725

Department of Philosophy, University of Arizona.

Placeholder essentialism is the view that there is a causal essence that holds category members together, though we may not know what the essence is. Sometimes the placeholder can be filled in by scientific essences, such as when we acquire scientific knowledge that the atomic weight of gold is 79. We challenge the view that placeholders are elaborated by scientific essences. Read More

J Microsc 2019 Apr 18. Epub 2019 Apr 18.

Karlsruhe Institute of Technology South Campus, Laboratory for Electron Microscopy (LEM), Karlsruhe, Baden-Württemberg, Germany.

Scanning transmission electron microscopy (STEM) at low primary electron energies has received increasing attention in recent years because knock-on damage can be avoided and high contrast for weakly scattering materials is obtained. However, the broadening of the electron beam in the sample is pronounced at low electron energies, which degrades resolution and limits the maximum specimen thickness. In this work, we have studied electron beam broadening in materials with atomic numbers Z between 10 and 32 (MgO, Si, SrTiO , Ge) and thicknesses up to 900 nm. Read More

J Am Soc Mass Spectrom 2019 Apr 18. Epub 2019 Apr 18.

Department of Chemistry, Clemson University, Clemson, SC, 29634, USA.

Many fundamental questions of astrophysics, biochemistry, and geology rely on the ability to accurately and precisely measure the mass and abundance of isotopes. Taken a step further, the capacity to perform such measurements on intact molecules provides insights into processes in diverse biological systems. Described here is the coupling of a combined atomic and molecular (CAM) ionization source, the liquid sampling-atmospheric pressure glow discharge (LS-APGD) microplasma, with a commercially available ThermoScientific Fusion Lumos mass spectrometer. Read More

Nanoscale Res Lett 2019 Apr 18;14(1):139. Epub 2019 Apr 18.

Department of Physics, OSED, Xiamen University, Xiamen, 361005, China.

In this study, aluminum oxide (AlO) films were prepared by a spatial atomic layer deposition using deionized water and trimethylaluminum, followed by oxygen (O), forming gas (FG), or two-step annealing. Minority carrier lifetime of the samples was measured by Sinton WCT-120. Field-effect passivation and chemical passivation were evaluated by fixed oxide charge (Q) and interface defect density (D), respectively, using capacitance-voltage measurement. Read More

Environ Monit Assess 2019 Apr 18;191(5):290. Epub 2019 Apr 18.

Department of Biological Sciences, Wesley University, Ondo, Nigeria.

This study was carried out to determine the concentrations of heavy metals in the soil samples collected from an abandoned lead acid battery (LAB) industrial waste dumpsite in Ibadan, southwestern Nigeria. This was to assess the potential risks of the heavy metals on human due to exposure among local residents (children and adults) of the area. Forty (40) soil samples were collected over the entire dumpsite at 0-20 cm depth. Read More

Environ Monit Assess 2019 Apr 18;191(5):289. Epub 2019 Apr 18.

Department of Civil Engineering, Gopalan College of Engineering and Management, K.R. Puram, Whitefield, Bangalore, 560048, India.

Heavy metals, due to their non-biodegradability and tendency to cause detrimental effects in human beings, are considered as the most hazardous and toxic pollutants. The present investigation was taken up to evaluate the heavy metal concentrations in the groundwaters of Peenya Industrial Area in Bangalore. The concentration of six eco-toxic metals such as chromium, copper, cadmium, iron, nickel, and lead were analyzed for 30 groundwater sampling stations in the study area using atomic absorption spectrometer. Read More

Biomed Res Int 2019 14;2019:9692053. Epub 2019 Mar 14.

Department of Biotechnology, Kazakh National University, Named After Al-Farabi, Almaty, Kazakhstan.

Deficiency of metals, primarily Fe and Zn, affects over half of the world's population. Human diets dominated by cereal products cause micronutrient malnutrition, which is common in many developing countries where populations depend heavily on staple grain crops such as wheat, maize, and rice. Biofortification is one of the most effective approaches to alleviate malnutrition. Read More

Front Chem 2019 3;7:197. Epub 2019 Apr 3.

Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research - IEK-6: Nuclear Waste Management and Reactor Safety, Jülich, Germany.

Lanthanide phosphates () are considered as a potential nuclear waste form for immobilization of Pu and minor actinides (Np, Am, and Cm). In that respect, in the recent years we have applied advanced atomistic simulation methods to investigate various properties of these materials on the atomic scale. In particular, we computed several structural, thermochemical, thermodynamic and radiation damage related parameters. Read More

J Phys Chem C Nanomater Interfaces 2019 Apr 25;123(14):8892-8901. Epub 2019 Mar 25.

Debye Institute for Nanomaterials Science, Utrecht University, PO Box 80000, 3508 TA Utrecht, The Netherlands.

On-surface synthesis has emerged in the last decade as a method to create graphene nanoribbons (GNRs) with atomic precision. The underlying premise of this bottom-up strategy is that precursor molecules undergo a well-defined sequence of inter- and intramolecular reactions, leading to the formation of a single product. As such, the structure of the GNR is encoded in the precursors. Read More

Front Microbiol 2019 29;10:573. Epub 2019 Mar 29.

Univ. Grenoble Alpes, CEA, CNRS, Institut de Biologie Structurale (IBS), Grenoble, France.

The type three secretion system (T3SS) is a macromolecular protein nano-syringe used by different bacterial pathogens to inject effectors into host cells. The extracellular part of the syringe is a needle-like filament formed by the polymerization of a 9-kDa protein whose structure and proper localization on the bacterial surface are key determinants for efficient toxin injection. Here, we combined , , and approaches to characterize the T3SS needle and its major component PscF. Read More

J Pak Med Assoc 2019 Apr;69(4):499-503

Lahore College For Women University, Lahore, Pakistan.

Objective: To find out the correlation between arsenic concentration in drinking water and biological samples of young male respondents.

Methods: The cross-sectional study was conducted at Lahore College for Women University, Lahore, Pakistan, from March 2013 to February 2015, and comprised biological samples i.e. Read More

Sci Rep 2019 Apr 18;9(1):6286. Epub 2019 Apr 18.

Université de Lyon, Ecole Centrale de Lyon, LTDS CNRS 5513, 69134, Ecully, France.

An impressive superlow coefficient of friction (CoF) as low as 0.004 (nearly equivalent to the rolling coefficient) was obtained by sliding a steel ball against a tetrahedral amorphous diamond-like carbon (ta-C) coating in glycerol under a boundary lubrication regime. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) revealed substantial changes in the surface chemistry and topography in the friction track. Read More

Sci Rep 2019 Apr 18;9(1):6275. Epub 2019 Apr 18.

Institute for Materials Research, Tohoku Univ, Sendai, 980-8577, Japan.

Study of arsenic (As) provides guidelines for the development of next-generation materials. We clarify the unique structure of the third crystalline polymorph of natural As (Pnm2-As) by crystallographical experiment and the electronic structure by first-principles computational method. The crystal structure of Pnm2-As is a novel structure in which the basic portions of semi-metalic grey-As and semi-conductor black-As are alternately arranged at the atomic level. Read More

Sci Rep 2019 Apr 18;9(1):6244. Epub 2019 Apr 18.

Department of Materials Science and Engineering, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul, 03722, Republic of Korea.

Zinc oxide (ZnO) nanocrystals (NCs) were synthesized using a modified sol-gel method. Ultraviolet (UV) treatment was performed under various atmospheres on the highly stacked ZnO NCs. The prepared NCs were characterized using Fourier transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, photoluminescence spectroscopy, and atomic force microscopy to investigate their structural, electrical, and electrochemical properties. Read More

Science 2019 Apr 18;364(6437):264-268. Epub 2019 Apr 18.

Materials Research Institute, Department of Materials Science and Engineering, Pennsylvania State University, University Park, PA 16802, USA.

High-performance piezoelectrics benefit transducers and sensors in a variety of electromechanical applications. The materials with the highest piezoelectric charge coefficients () are relaxor-PbTiO crystals, which were discovered two decades ago. We successfully grew Sm-doped Pb(MgNb)O-PbTiO (Sm-PMN-PT) single crystals with even higher values ranging from 3400 to 4100 picocoulombs per newton, with variation below 20% over the as-grown crystal boule, exhibiting good property uniformity. Read More

EMBO J 2019 Apr 18. Epub 2019 Apr 18.

Université Côte d'Azur, Centre National de la Recherche Scientifique (CNRS) UMR7284, Institut National de la Santé et de la Recherche Médicale (INSERM) U1081, Institute for Research on Cancer and Aging, Nice (IRCAN), Nice, France

Myeloid-derived suppressor cells (MDSCs) are immature myeloid cells with strong immunosuppressive activity that promote tumor growth. In this study, we describe a mechanism by which cancer cells control MDSCs in human cancers by upregulating TRF2, a protein required for telomere stability. Specifically, we showed that the TRF2 upregulation in cancer cells has extratelomeric roles in activating the expression of a network of genes involved in the biosynthesis of heparan sulfate proteoglycan, leading to profound changes in glycocalyx length and stiffness, as revealed by atomic force microscopy. Read More

Pulmonology 2019 Apr 15. Epub 2019 Apr 15.

Department of Molecular and Internal Medicine, Institute of Biomedical & Health Sciences, Hiroshima University, Minami-ku, Hiroshima, Japan.

Enzyme Microb Technol 2019 Jul 1;126:50-61. Epub 2019 Apr 1.

Laboratório de Genética Molecular, Departamento de Biologia, Centro de Ciências, UFC, Fortaleza, CE, Brazil. Electronic address:

The biocontrol activity of some soil strains of Chromobacterium sp. against pathogenic fungi has been attributed to secreted chitinases. The aim of this work was to characterize biochemically a recombinant chitinase (CvChi47) from C. Read More

Food Chem 2019 Aug 27;290:295-307. Epub 2019 Mar 27.

Isotope Bioscience Laboratory - ISOFYS, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000 Gent, Belgium.

To test the potential of different analytical tools to determine the geographical origin of Ethiopian coffee, 103 green arabica coffee samples from four coffee regions in Ethiopia were subjected to multi-elements and δC, δN and δO determinations. Multi-elements were determined by using inductively coupled plasma (ICP)- and X-ray fluorescence spectrometry (XRF)-based techniques, and δC, δN and δO were determined by using elemental analyzer-isotope ratio mass spectrometry. Using linear discriminant analysis, XRF-based multi-elements with and without δC appeared to be most effective in discriminating the geographical origin of coffee, giving higher classification accuracy (89 and 86%, respectively) than ICP-based multi-elements with and without stable isotopes (80%, each). Read More

Food Chem 2019 Aug 25;290:10-15. Epub 2019 Mar 25.

Gazi University, Faculty of Pharmacy, Analytical Chemistry Department, 06330 Ankara, Turkey.

A rapid on-line non-chromatographic hydride generation atomic fluorescence spectrometry is described and determination of inorganic arsenic (iAs (III) and iAs (V)) species is achieved within a single run. Thioglycolic acid (TGA) was used for on-line pre-reduction of iAs (V) and quantification of arsenic species was accomplished via calibration with one As form; as iAs (III). Samples and calibration standards were prepared in Tris buffer (pH:7. Read More

Molecules 2019 Apr 17;24(8). Epub 2019 Apr 17.

Instituto Politécnico Nacional ⁻ CNMN, Unidad Profesional Adolfo López Mateos, Col. Zacatenco, México City, CDMX CP 07738, México.

10,16-dihydroxyhexadecanoic acid obtained from agroresidual tomato waste, was oxidized to produce 7-oxohexadecanedioic acid in good yield (>70%) and purified without oxidation side products in one step. Polycondensation with 1,8-octanediol, yielded the polyester (poly(-carboxyl PA--OD)) with M = 2155.15 and M = 1637. Read More

Nanomaterials (Basel) 2019 Apr 17;9(4). Epub 2019 Apr 17.

School of Mathematics and physics, Jingchu University of Technology, Jingmen 448000, China.

Using methane as a carbon source, low-dimensional carbon nanomaterials were obtained in this work. The films were deposited directly on glass substrates by radio frequency plasma-enhanced chemical vapor deposition (RF-PECVD). The configuration and compositions of this nanographite films were identified by X-ray photoelectron spectroscopy (XPS) as carbon in sp bonding form. Read More

Polymers (Basel) 2019 Apr 17;11(4). Epub 2019 Apr 17.

School of Physics and Electronic Science, Guizhou Education University, Guiyang 550018, China.

The outstanding diffusivity and permeability of supercritical carbon dioxide (scCO) are extremely beneficial for grafting reaction. In this work, aramid fibers (AF) are modified in scCO by glycidyl-polyhedral oliomeric silsesquioxane (POSS) with 2-ethyl-4-methylimidazole (2E4MZ) on the basis of cleaning with acetone. The surface morphology and chemical structure of the modified AF were measured and characterized by Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), Scanning electron microscope (SEM), Thermogravimetric (TG), and Atomic force microscope (AFM). Read More

Materials (Basel) 2019 Apr 17;12(8). Epub 2019 Apr 17.

ALPhANOV, Technological Centre for Optics and Lasers, Optic Institute of Aquitaine, rue F. Mitterrand, 33400 Talence, France.

Laser-induced textures have been proven to be excellent solutions for modifying wetting, friction, biocompatibility, and optical properties of solids. The possibility to generate 2D-submicron morphologies by laser processing has been demonstrated recently. Employing double-pulse irradiation, it is possible to control the induced structures and to fabricate novel and more complex 2D-textures. Read More

Eur Phys J C Part Fields 2018 24;78(2):165. Epub 2018 Feb 24.

179University of Wisconsin-Madison, Madison, WI USA.

Four-lepton production in proton-proton collisions, , where or , is studied at a center-of-mass energy of 13 with the CMS detector at the LHC. The data sample corresponds to an integrated luminosity of 35.9 . Read More

New J Phys 2018 ;20

Institute of Theoretical Physics and Astronomy, Vilnius University, Saulėtekio 3, LT-10222 Vilnius, Lithuania.

We describe anoveltechniqueforcreatinganartificialmagneticfieldforultracoldatomsusinga periodicallypulsedpairofcounterpropagatingRamanlasersthatdrivetransitionsbetween a pair of internal atomic spin states: a multi-frequency coupling term. In conjunction with a magnetic field gradient, this dynamically generates a rectangular lattice with a non-staggered magnetic flux. For a wide range of parameters, the resulting Bloch bands have non-trivial topology, reminiscent of Landau levels, as quantified by their Chern numbers. Read More

Biomaterials 2019 Apr 8;208:83-97. Epub 2019 Apr 8.

Department of Pharmaceutical Sciences and Center for Cancer Research, University of Tennessee Health Science Center, Memphis, USA. Electronic address:

Pancreatic cancer is a complex disease accounting for fibrotic tumors and an aggressive phenotype. Gemcitabine (GEM) is used as a standard therapy, which develops chemoresistance leading to poor patient outcome. We have recently developed a superparamagnetic iron oxide nanoparticle (SPION) formulation of curcumin (SP-CUR), which is a nontoxic, bioactive anti-inflammatory/anti-cancer agent for its enhanced delivery in tumors. Read More

Arch Biochem Biophys 2019 Apr 15. Epub 2019 Apr 15.

Nanoscience & Nanotechnology & Innovative Instrumentation (NAST) Centre, University of Rome Tor Vergata, Rome, Italy; Department of Experimental Medicine, University of Rome Tor Vergata, Rome, Italy; Sanford Burnham Prebys Medical Discovery Institute, La Jolla, CA, 92037, USA. Electronic address:

Matrix vesicles (MVs) are a class of extracellular vesicles that initiate mineralization in cartilage, bone, and other vertebrate tissues by accumulating calcium ions (Ca) and inorganic phosphate (P) within their lumen and forming a nucleation core (NC). After further sequestration of Ca and P, the NC transforms into crystalline complexes. Direct evidence of the existence of the NC and its maturation have been provided solely by analyses of dried samples. Read More

ACS Nano 2019 Apr 18. Epub 2019 Apr 18.

Exploring Pt-free electrocatalysts with high activity and long durability for the oxygen reduction reaction (ORR) has been long pursued by the renewable energy material community. In this work, we have designed an ordered intermetallics PdZn/C (O-PdZn) with a several atomic-layer Pd shell, which achieved a three-fold enhancement in ORR mass activities (MA) in alkaline media, relative to Pd/C and Pt/C. Further Au incorporation in O-PdZn/C (Au-O-PdZn/C) yielded a catalyst with superior durability with less than 10% loss in MA after 30,000 potential cycles. Read More

Nano Lett 2019 Apr 18. Epub 2019 Apr 18.

Bulk and single-layer NbSe2 exhibit identical charge density wave order (CDW) with a quasi-commensurate 3x3 superlattice periodicity. Here we combine scanning tunnelling microscopy (STM) imaging at T = 1 K of 2H-NbSe2 with first-principles density functional theory (DFT) calculations to investigate the structural atomic rearrangement of this CDW phase. Our calculations reveal that six different atomic structures are compatible with the 3×3 CDW distortion, although all of them lie on a very narrow energy range of at most 3 meV per formula unit, suggesting the coexistence of such structures. Read More

Angew Chem Int Ed Engl 2019 Apr 18. Epub 2019 Apr 18.

Lanzhou University, 222 South Tianshui Rd, Lanzhou, CHINA.

Atomic-thick interfacial dominated bifunctional catalyst NiO/CoO transition interfacial nanowires (TINWs) with abundant coordinational defective sites display high electroactivities and durabilities in the oxygen evolution reaction (OER) and the oxygen reduction reaction (ORR). Density functional theory (DFT) calculations unravel that the excellent OER/ORR performance arises from the electron-rich interfacial region coupled with coordinational defective sites, thus endows the fast-redox rate with lower activation barrier for fast electron transfer. When assembled as air-electrode, NiO/CoO TINWs delivered the high specific capacity of 842. Read More

Adv Mater 2019 Apr 17:e1900862. Epub 2019 Apr 17.

School of Materials Science and Engineering, Nanyang Technological University, Singapore, 639798, Singapore.

Alloying 2D transition metal dichalcogenides has opened up new opportunities for bandgap engineering and phase control. Developing a simple and scalable synthetic route is therefore essential to explore the full potential of these alloys with tunable optical and electrical properties. Here, the direct synthesis of monolayer WTe S alloys via one-step chemical vapor deposition (CVD) is demonstrated. Read More

Chembiochem 2019 Apr 17. Epub 2019 Apr 17.

Karolinska Institute, Medical Biochemistry and Biophysics, Scheeles Väg 2, 17177, Stockholm, SWEDEN.

An ever-increasing number of functional RNAs require mechanistic understanding. RNA function relies on changes in its structure, so-called dynamics. To reveal dynamic processes and higher energy structures, new Nuclear Magnetic Resonance (NMR) methods have been developed to elucidate these dynamics in RNA with atomic resolution. Read More

Adv Mater 2019 Apr 18:e1901185. Epub 2019 Apr 18.

Centre for Advanced 2D Materials (CA2DM) and Graphene Research Centre (GRC), National University of Singapore, 6 Science Drive 2, Singapore, 117546, Singapore.

Monolayer VSe , featuring both charge density wave and magnetism phenomena, represents a unique van der Waals magnet in the family of metallic 2D transition-metal dichalcogenides (2D-TMDs). Herein, by means of in situ microscopy and spectroscopic techniques, including scanning tunneling microscopy/spectroscopy, synchrotron X-ray and angle-resolved photoemission, and X-ray absorption, direct spectroscopic signatures are established, that identify the metallic 1T-phase and vanadium 3d electronic configuration in monolayer VSe grown on graphite by molecular-beam epitaxy. Element-specific X-ray magnetic circular dichroism, complemented with magnetic susceptibility measurements, further reveals monolayer VSe as a frustrated magnet, with its spins exhibiting subtle correlations, albeit in the absence of a long-range magnetic order down to 2 K and up to a 7 T magnetic field. Read More

Radiat Environ Biophys 2019 Apr 17. Epub 2019 Apr 17.

Institute of Physics, Jagiellonian University, Kraków, Poland.

This paper presents the results of measurements of Tc activity concentrations in indoor air in a nuclear medicine department and resulting estimated Tc intake by medical personnel. Tc air activity measurements were conducted at the Nuclear Medicine Department, John Paul II Hospital, Krakow, Poland, during ventilation-perfusion SPECT lung scans. Technetium from the air was collected by means of a mobile aerosol sampler with a Petryanov filter operating at an average flow rate of 10 dm min. Read More

Nanoscale Res Lett 2019 Apr 17;14(1):136. Epub 2019 Apr 17.

Center for Precision Engineering, Harbin Institute of Technology, Harbin, 150001, Heilongjiang, People's Republic of China.

In current research realm, polydimethylsiloxane (PDMS)-based nanofluidic devices are widely used in medical, chemical, and biological applications. In the present paper, a novel nanomilling technique (consisting of an AFM system and a piezoelectric actuator) was proposed to fabricate nanochannels (with controllable sizes) on PDMS chips, and nanochannel size was controlled by the driving voltage and frequency inputted to the piezoelectric actuator. Moreover, microchannel and nanochannel molds were respectively fabricated by UV lithography and AFM tip-based nanomilling, and finally, PDMS slabs with micro/nanochannels were obtained by transfer process. Read More

J Mol Model 2019 Apr 17;25(5):120. Epub 2019 Apr 17.

Institute of Atomic and Molecular Physics, Sichuan University, Chengdu, 610065, China.

Establishment of an equation of state (EOS) for detonation products is challenging through molecular modeling approaches. Molecular dynamics (MD) simulations with the reactive force fields (ReaxFF) were carried out in this work for molecular N and HO and their mixtures, which are key components of detonation products, with high density and under high temperature, and compared with the experiment-based Becker-Kistiakowsky-Wilson (BKW) and the Lennard-Jones potential-based Tsien-Zhao (TZ) equations. Phase separations were noted for the mixtures, enhanced for denser systems under low temperature, and detracted for sparse systems under high temperature. Read More

Chem Sci 2019 Mar 20;10(12):3671-3680. Epub 2019 Feb 20.

Computational Structural Biology Section , Basic Science Program , Frederick National Laboratory for Cancer Research , Frederick , MD 21702 , USA . Email:

PI3K lipid kinases phosphorylate PIP to PIP in the PI3K/Akt/mTOR pathway to regulate cellular processes. They are frequently mutated in cancer. Here we determine the PI3Kα activation mechanism at the atomic level. Read More

Chem Sci 2019 Mar 14;10(12):3643-3648. Epub 2019 Feb 14.

Institute of Analytical Chemistry of the Czech Academy of Sciences , Veveří 97 , 60200 Brno , Czech Republic . Email:

In an externally heated quartz atomizer, the most often used hydride atomizer for atomic absorption spectrometry, two-photon absorption laser-induced fluorescence (TALIF) was employed (i) to bring after four decades for the first time conclusive proof of the existence of H radical population sufficient to atomize hydrides thus confirming unambiguously the radical theory of hydride atomization and (ii) to determine the distribution of H radicals in the atomizer. Under typical operating conditions, H radicals are concentrated in an approximately 3 mm long cloud in the center of the optical arm and their peak concentration exceeds 10 m, four orders of magnitude above the typical analytical concentration of hydride. The lowest detectable H radical concentration is in the order of 10 m. Read More