39,270 results match your criteria orders magnitude


Wide-field determination of aqueous mercury(II) based on tail-extensible DNA fluorescent probe with tunable dynamic range.

J Hazard Mater 2021 May 8;417:125975. Epub 2021 May 8.

Hunan Provincial Key Laboratory of Micro & Nano Materials Interface Science, College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, PR China. Electronic address:

Mercury (Hg) is one of the most hazardous pollutants, widely distributed in water, atmosphere, and soil, while the Hg contents from different sources are greatly different. Until now, numerous reported methods are only suitable for a kind of sample because they cannot reconcile sensitivity and linear range. In this work, a tail-extensible DNA fluorescent probe for "turn on" detection of Hg with tunable dynamic range and high sensitivity was developed, which was based on segmental hybridization between silver nanoclusters (AgNCs)-covered DNA and different guanine-rich DNAs. Read More

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Development and optimization of a TaqMan assay for Nosema bombycis, causative agent of pébrine disease in Bombyx mori silkworm, based on the β-tubulin gene.

J Microbiol Methods 2021 May 12:106238. Epub 2021 May 12.

Genomic Division, Seri Biotech Research Laboratory, Carmelaram Post, Kodathi, Bengaluru 560035, India.

"Pébrine" is a devastating disease of Bombyx mori silkworms that is highly contagious and can completely destroy an entire crop of silkworms and is thus a serious threat for the viability and profitability of sericulture. The disease is most commonly attributed to microsporidians of the genus Nosema, which are obligate intracellular parasites that are transmitted through spores. Nosema infections in silkworms are diagnosed primarily through light microscopy, which is labour intensive and less reliable, sensitive, and specific than PCR-based techniques. Read More

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Quantitative analysis of fine dust particles on moss surfaces under laboratory conditions using the example of Brachythecium rutabulum.

Environ Sci Pollut Res Int 2021 May 15. Epub 2021 May 15.

German Institutes of Textile and Fiber Research, Körschtalstraße 26, 73770, Denkendorf, Germany.

The identification of a model organism for investigations of fine dust deposits on moss leaflets was presented. An optical method with SEM enabled the quantitative detection of fine dust particles in two orders of magnitude. Selection criteria were developed with which further moss species can be identified in order to quantify the number of fine dust particles on moss surfaces using the presented method. Read More

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Hunter-Gatherers in context: Mammal community composition in a northern Tanzania landscape used by Hadza foragers and Datoga pastoralists.

PLoS One 2021 14;16(5):e0251076. Epub 2021 May 14.

Department of Human Behavior, Ecology and Culture, Max Planck Institute for Evolutionary Anthropology, Leipzig, Germany.

In many regions of sub Saharan Africa large mammals occur in human-dominated areas, yet their community composition and abundance have rarely been described in areas occupied by traditional hunter-gatherers and pastoralists. Surveys of mammal populations in such areas provide important measures of biodiversity and provide ecological context for understanding hunting practices. Using a sampling grid centered on a Hadza hunter-gatherer camp and covering 36 km2 of semi-arid savannah in northern Tanzania, we assessed mammals using camera traps (n = 19 stations) for c. Read More

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An Alternative Generic Subslab Soil Gas-to-Indoor Air Attenuation Factor for Application in Commercial, Industrial, and Other Nonresidential Settings.

J Air Waste Manag Assoc 2021 May 14. Epub 2021 May 14.

Naval Facilities Engineering Command - Atlantic Division, Norfolk, VA, USA.

The default subslab soil gas (SSSG)-to-indoor air attenuation factor (AF) of 0.03 to assess the vapor intrusion (VI) pathway and generate VI screening levels for SSSG was developed by the United States Environmental Protection Agency (EPA) based on chlorinated volatile organic compound (VOC) indoor air and SSSG data collected in residential buildings and compiled in EPA's 2012 VI database. In their VI guidance published in 2015, EPA recognized that this default AF may be overly conservative for nonresidential buildings. Read More

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EDGAR3.0: comparative genomics and phylogenomics on a scalable infrastructure.

Nucleic Acids Res 2021 May 14. Epub 2021 May 14.

Bioinformatics & Systems Biology, Justus Liebig University Gießen, Heinrich-Buff-Ring 58, 35390 Gießen, Hesse, Germany.

The EDGAR platform, a web server providing databases of precomputed orthology data for thousands of microbial genomes, is one of the most established tools in the field of comparative genomics and phylogenomics. Based on precomputed gene alignments, EDGAR allows quick identification of the differential gene content, i.e. Read More

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PERSPECTIVE: Critical Cooling and Warming Rates as a Function of CPA Concentration.

Authors:
Z Han J C Bishop

Cryo Letters 2020 Jul-Aug;41(4):185-193

Department of Mechanical Engineering; Department of Biomedical Engineering, University of Minnesota, Minneapolis, USA.

Cryoprotective agents (CPAs) are routinely applied in cryopreservation protocols to achieve the vitrified state thereby avoiding the damaging effects of ice crystals. Once the CPA has been added, the system needs to cool at a rate ≥ critical cooling rate (CCR) to avoid ice crystallization and successfully enter the vitrified state. Subsequently, upon warming the system needs to meet or exceed a critical warming rate (CWR), often one to two orders of magnitude higher than the CCR, to avoid ice formation and return the system to physiological temperatures for use. Read More

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Experimental Constraint on Axionlike Particles over Seven Orders of Magnitude in Mass.

Phys Rev Lett 2021 Apr;126(17):171301

JILA, NIST and University of Colorado, Boulder, Colorado 80309, USA.

We use our recent electric dipole moment (EDM) measurement data to constrain the possibility that the HfF^{+} EDM oscillates in time due to interactions with candidate dark matter axionlike particles (ALPs). We employ a Bayesian analysis method which accounts for both the look-elsewhere effect and the uncertainties associated with stochastic density fluctuations in the ALP field. We find no evidence of an oscillating EDM over a range spanning from 27 nHz to 400 mHz, and we use this result to constrain the ALP-gluon coupling over the mass range 10^{-22}-10^{-15}  eV. Read More

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Testing Quantum Electrodynamics with Exotic Atoms.

Phys Rev Lett 2021 Apr;126(17):173001

Laboratoire Kastler Brossel, Sorbonne Université, CNRS, ENS-PSL Research University, Collège de France, Case 74; 4, place Jussieu, F-75005 Paris, France.

Precision study of few-electron, high-Z ions is a privileged field for probing high-field, bound-state quantum electrodynamics (BSQED). However, the accuracy of such tests is plagued by nuclear uncertainties, which are often larger than the BSQED effects under investigation. We propose an alternative method with exotic atoms and show that transitions may be found between circular Rydberg states where nuclear contributions are vanishing while BSQED effects remain large. Read More

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Universality of Time-Temperature Scaling Observed by Neutron Spectroscopy on Bottlebrush Polymers.

Nano Lett 2021 May 14. Epub 2021 May 14.

Department of Physics & Astronomy, Louisiana State University, Baton Rouge, Louisiana 70803, United States.

The understanding of materials requires access to the dynamics over many orders of magnitude in time; however, single analytical techniques are restricted in their respective time ranges. Assuming a functional relationship between time and temperature is one viable tool to overcome these limits. Despite its frequent usage, a breakdown of this assertion at the glass-transition temperature is common. Read More

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Separating and trapping of chiral nanoparticles with dielectric photonic crystal slabs.

Opt Express 2021 May;29(10):15177-15189

Chiral separation is a crucial step in many chemical synthesis processes, particularly for pharmaceuticals. Here we present a novel method for the realization of both separating and trapping of enantiomers using the dielectric photonic crystal (PhC) slabs, which possess quasi-fourfold degenerate Bloch modes (overlapping double degenerate transverse-electric-like and transverse-magnetic-like modes). Based on the designed structure, a large gradient of optical chirality appears near the PhC slab, leading to the extreme enhancement of chiral optical forces about 3 orders of magnitude larger than those obtained with circularly polarized lights. Read More

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Hybrid integrated mode-locked laser diodes with a silicon nitride extended cavity.

Opt Express 2021 May;29(10):15013-15022

Integrated semiconductor mode-locked lasers have shown promise in many applications and are readily fabricated using generic InP photonic integration platforms. However, the passive waveguides offered in such platforms have relatively high linear and nonlinear losses that limit the performance of these lasers. By extending such lasers with, for example, an external cavity, the performance can be increased considerably. Read More

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Hydrostatic pressure effect of photocarrier dynamics in GaAs probed by time-resolved terahertz spectroscopy.

Opt Express 2021 Apr;29(9):14058-14068

Pressure effects on photocarrier dynamics such as interband relaxations and intraband cooling in GaAs have been investigated using in situ time-resolved terahertz spectroscopy with a diamond anvil cell. The interband photocarrier lifetime significantly decreases by nearly two orders of magnitude as the external hydrostatic pressure is increased up to 10 GPa. Considerable pressure tuning for the intervalley scattering processes has also been observed, and the time constants under different pressures are extracted based on the three-state rate model. Read More

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Ultracompact electro-optic waveguide modulator based on a graphene-covered λ/1000 plasmonic nanogap.

Opt Express 2021 Apr;29(9):13852-13863

The extreme field confinement and electro-optic tunability of plasmons in graphene make it an ideal platform for compact waveguide modulators, with device footprints aggressively scaling orders of magnitude below the diffraction limit. The miniaturization of modulators based on graphene plasmon resonances is however inherently constrained by the plasmon wavelength, while their performance is bounded by material loss in graphene. In this report, we propose to overcome these limitations using a graphene-covered λ/1000 plasmonic nanogap waveguide that concentrates light on length scales more than an order of magnitude smaller than the graphene plasmon wavelength. Read More

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Highly efficient polarization-entangled photon-pair generation in lithium niobate waveguides based on bound states in continuum.

Opt Express 2021 Apr;29(8):12110-12123

Integrated optics provides a platform for the experimental implementation of highly complex and compact circuits for practical applications as well as for advances in the fundamental science of quantum optics. The lithium niobate (LN) waveguide is an important candidate for the construction of integrated optical circuits. Based on the bound state in the continuum (BIC) in a LN waveguide, we propose an efficient way to produce polarization-entangled photon pairs. Read More

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Nonlinear modulation on optical trapping in a plasmonic bowtie structure.

Opt Express 2021 Apr;29(8):11664-11673

Surface plasmon optical tweezers based on micro- and nano-structures are capable of capturing particles in a very small spatial scale and have been widely used in many front research fields. In general, distribution of optical forces and potential wells exerted on the particles can be modulated by controlling the geometric parameters of the structures. However, these fabricated structures are irreversible once processed, which greatly limits its application in dynamic manipulation. Read More

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Strawberry fruit skins are far more permeable to osmotic water uptake than to transpirational water loss.

PLoS One 2021 13;16(5):e0251351. Epub 2021 May 13.

Institute for Horticultural Production Systems, Leibniz-Universität Hannover, Hannover, Germany.

Water movements through the fruit skin play critical roles in many disorders of strawberry (Fragaria × ananassa Duch.) such as water soaking, cracking and shriveling. The objective was to identify the mechanisms of fruit water loss (dry skin, transpiration) and water uptake (wet skin, osmosis). Read More

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Ten steps to investigate a cellular system with mathematical modeling.

PLoS Comput Biol 2021 May 13;17(5):e1008921. Epub 2021 May 13.

MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, the Netherlands.

Cellular and intracellular processes are inherently complex due to the large number of components and interactions, which are often nonlinear and occur at different spatiotemporal scales. Because of this complexity, mathematical modeling is increasingly used to simulate such systems and perform experiments in silico, many orders of magnitude faster than real experiments and often at a higher spatiotemporal resolution. In this article, we will focus on the generic modeling process and illustrate it with an example model of membrane lipid turnover. Read More

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THz-TDS parameter extraction: empirical correction terms for the analytical transfer function solution.

Appl Opt 2021 May;60(13):4013-4020

Terahertz time-domain spectroscopy (TDS) is capable of determining both real and imaginary refractive indices of a wide range of material samples; however, converting the TDS data into complex refractive indices typically involves iterative algorithms that are computationally slow, involve complex analysis steps, and can sometimes lead to non-convergence issues. To avoid using iterative algorithms, it is possible to solve the transfer function analytically by assuming the material loss is low; however, this leads to errors in the refractive index values. Here we demonstrate how the errors created by solving the transfer function analytically are largely predictable, and present a set of empirically derived equations to diminish the error associated with this analytical solution by an impressive two to three orders of magnitude. Read More

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Stabilized photonic links for space applications.

Appl Opt 2021 Apr;60(12):3487-3491

We describe basic principles of operation and report on implementation of a standalone photonic link stabilized using the electronic phase conjugation technique. This method has been demonstrated to improve link stability by more than 2 orders while reducing its size and power consumption compared to other systems. We have demonstrated packaged robust links that achieve a relative frequency instability of 2×10 (5×10) at 10 h averaging while the temperature of the fiber was varied with 2°C (15°C) magnitude. Read More

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Hyperpolarized MRI with silicon micro and nanoparticles: Principles and applications.

Wiley Interdiscip Rev Nanomed Nanobiotechnol 2021 May 13:e1722. Epub 2021 May 13.

Department of Cancer Systems Imaging, The University of Texas MD Anderson Cancer Center, Houston, Texas, USA.

Silicon-based micro and nanoparticles are ideally suited for use as biomedical imaging agents because of their biocompatibility, biodegradability, and simple surface chemistry that facilitates drug loading and targeting. A method to hyperpolarize silicon particles using dynamic nuclear polarization (DNP), which increases magnetic resonance (MR) imaging signals by several orders-of-magnitude through enhanced nuclear spin alignment, was developed to allow silicon particles to function as contrast agents for in vivo magnetic resonance imaging. In this review, we describe the application of the DNP technique to silicon particles and nanoparticles for background-free real-time molecular MR imaging. Read More

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Effect of Unit Cell Shape on Switchable Infrared Metamaterial VO Absorbers/Emitters.

Research (Wash D C) 2021 22;2021:9804183. Epub 2021 Apr 22.

Center for Composite Materials and Structure, Harbin Institute of Technology, Harbin 150001, China.

Metamaterial absorber/emitter is an important aspect of infrared radiation manipulation. In this paper, we proposed four simple switchable infrared metamaterial absorbers/emitters with Ag/VO disks on the Ag plane employing triangle, square, hexagon, and circle unit cells. The spectral absorption peaks whose intensities are above 0. Read More

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Rapid highly sensitive general protein quantification through on-chip chemiluminescence.

Biomicrofluidics 2021 Mar 29;15(2):024113. Epub 2021 Apr 29.

Fluidic Analytics Ltd., Unit A The Paddocks Business Centre, Cherry Hinton Road, Cambridge CB1 8DH, United Kingdom.

Protein detection and quantification is a routinely performed procedure in research laboratories, predominantly executed either by spectroscopy-based measurements, such as NanoDrop, or by colorimetric assays. The detection limits of such assays, however, are limited to M concentrations. To establish an approach that achieves general protein detection at an enhanced sensitivity and without necessitating the requirement for signal amplification steps or a multicomponent detection system, here, we established a chemiluminescence-based protein detection assay. Read More

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Colossal topological Hall effect at the transition between isolated and lattice-phase interfacial skyrmions.

Nat Commun 2021 May 12;12(1):2758. Epub 2021 May 12.

Division of Physics and Applied Physics, School of Physical and Mathematical Sciences, Nanyang Technological University, Singapore, Singapore.

The topological Hall effect is used extensively to study chiral spin textures in various materials. However, the factors controlling its magnitude in technologically-relevant thin films remain uncertain. Using variable-temperature magnetotransport and real-space magnetic imaging in a series of Ir/Fe/Co/Pt heterostructures, here we report that the chiral spin fluctuations at the phase boundary between isolated skyrmions and a disordered skyrmion lattice result in a power-law enhancement of the topological Hall resistivity by up to three orders of magnitude. Read More

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Reducing the impact of radioactivity on quantum circuits in a deep-underground facility.

Nat Commun 2021 May 12;12(1):2733. Epub 2021 May 12.

PHI, Karlsruhe Institute of Technology, Karlsruhe, Germany.

As quantum coherence times of superconducting circuits have increased from nanoseconds to hundreds of microseconds, they are currently one of the leading platforms for quantum information processing. However, coherence needs to further improve by orders of magnitude to reduce the prohibitive hardware overhead of current error correction schemes. Reaching this goal hinges on reducing the density of broken Cooper pairs, so-called quasiparticles. Read More

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Risk trade-off analysis of returning home and radiation exposure after a nuclear disaster using a happy life expectancy indicator.

J Radiat Res 2021 May;62(Supplement_1):i101-i106

Research Center for Community Health, Minamisoma Municipal General Hospital, 2-54-6 Takami, Haramachi, Minamisoma, Fukushima, 975-0033, Japan.

It is crucial to evaluate ethical issues regarding evacuation orders, especially after a nuclear disaster. After the Fukushima accident in 2011, the Japanese government ordered the affected people to evacuate. The evacuation orders have now been lifted in many areas. Read More

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Effect of electron-phonon coupling on the transport properties of monolayers of ZrS, BiI and PbI: a thermoelectric perspective.

Phys Chem Chem Phys 2021 May 12. Epub 2021 May 12.

Department of Physics, Indian Institute of Science Education and Research, Pune, Maharashtra 411008, India. and Centre for Energy Sciences, Indian Institute of Science Education and Research, Pune, Maharashtra 411008, India.

Thermoelectric materials are used for the conversion of waste heat to electrical energy. The transport coefficients that determine their thermoelectric properties depend on the band structure and the relaxation time of the charge carriers. Both of these are significantly affected by electron-phonon coupling. Read More

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Superconducting diode effect via conformal-mapped nanoholes.

Nat Commun 2021 May 11;12(1):2703. Epub 2021 May 11.

Materials Science Division, Argonne National Laboratory, Argonne, IL, USA.

A superconducting diode is an electronic device that conducts supercurrent and exhibits zero resistance primarily for one direction of applied current. Such a dissipationless diode is a desirable unit for constructing electronic circuits with ultralow power consumption. However, realizing a superconducting diode is fundamentally and technologically challenging, as it usually requires a material structure without a centre of inversion, which is scarce among superconducting materials. Read More

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Selective inhibition of cullin 3 neddylation through covalent targeting DCN1 protects mice from acetaminophen-induced liver toxicity.

Nat Commun 2021 May 11;12(1):2621. Epub 2021 May 11.

Department of Internal Medicine, University of Michigan, Ann Arbor, MI, USA.

Cullin-RING E3 ligases (CRLs) regulate the turnover of approximately 20% of mammalian cellular proteins. Neddylation of individual cullin proteins is essential for the activation of each CRL. We report herein the discovery of DI-1548 and DI-1859 as two potent, selective and covalent DCN1 inhibitors. Read More

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Atomic-scale insights into quantum-order parameters in bismuth-doped iron garnet.

Proc Natl Acad Sci U S A 2021 May;118(20)

National Center for Electron Microscopy in Beijing, School of Materials Science and Engineering, Tsinghua University, 100084 Beijing, People's Republic of China;

Bismuth and rare earth elements have been identified as effective substituent elements in the iron garnet structure, allowing an enhancement in magneto-optical response by several orders of magnitude in the visible and near-infrared region. Various mechanisms have been proposed to account for such enhancement, but testing of these ideas is hampered by a lack of suitable experimental data, where information is required not only regarding the lattice sites where substituent atoms are located but also how these atoms affect various order parameters. Here, we show for a Bi-substituted lutetium iron garnet how a suite of advanced electron microscopy techniques, combined with theoretical calculations, can be used to determine the interactions between a range of quantum-order parameters, including lattice, charge, spin, orbital, and crystal field splitting energy. Read More

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