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Institution

National Physical Laboratory

FacilityLondon, United Kingdom
About: National Physical Laboratory is a facility organization based out in London, United Kingdom. It is known for research contribution in the topics: Dielectric & Thin film. The organization has 7615 authors who have published 13327 publications receiving 319381 citations.


Papers
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Journal ArticleDOI
TL;DR: The development of a 3D OrbiSIMS instrument for label-free biomedical imaging and single-cell metabolomic profiling are reported, and it is observed that the upregulation of phospholipid species and cholesterol is correlated with the accumulation of amiodarone.
Abstract: We report the development of a 3D OrbiSIMS instrument for label-free biomedical imaging. It combines the high spatial resolution of secondary ion mass spectrometry (SIMS; under 200 nm for inorganic species and under 2 μm for biomolecules) with the high mass-resolving power of an Orbitrap (>240,000 at m/z 200). This allows exogenous and endogenous metabolites to be visualized in 3D with subcellular resolution. We imaged the distribution of neurotransmitters-gamma-aminobutyric acid, dopamine and serotonin-with high spectroscopic confidence in the mouse hippocampus. We also putatively annotated and mapped the subcellular localization of 29 sulfoglycosphingolipids and 45 glycerophospholipids, and we confirmed lipid identities with tandem mass spectrometry. We demonstrated single-cell metabolomic profiling using rat alveolar macrophage cells incubated with different concentrations of the drug amiodarone, and we observed that the upregulation of phospholipid species and cholesterol is correlated with the accumulation of amiodarone.

258 citations

Journal ArticleDOI
TL;DR: An autonomous 'black-box' system for the controlled synthesis of fluorescent nanoparticles using a microfluidic reactor to carry out the synthesis and an in-line spectrometer to monitor the emission spectra of the emergent particles.
Abstract: We describe an autonomous ‘black-box’ system for the controlled synthesis of fluorescent nanoparticles. The system uses a microfluidic reactor to carry out the synthesis and an in-line spectrometer to monitor the emission spectra of the emergent particles. The acquired data is fed into a control algorithm which reduces each spectrum to a scalar ‘dissatisfaction coefficient’ and then intelligently updates the reaction conditions in an effort to minimise this coefficient and so drive the system towards a desired goal. In the tests reported here, CdSe nanoparticles were prepared by separately injecting solutions of CdO and Se into the two inlets of a heated y-shaped microfluidic reactor. A noise-tolerant global search algorithm was then used to efficiently identify—without any human intervention—the injection rates and temperature that yielded the optimum intensity for a chosen emission wavelength.

256 citations

Journal ArticleDOI
TL;DR: AION (Atom Interferometer Observatory and Network) as mentioned in this paper is a proposed UK-based experimental program using cold strontium atoms to search for ultra-light dark matter, to explore gravitational waves in the mid-frequency range between the peak sensitivities of the LISA and LIGO/Virgo/ KAGRA/INDIGO-Einstein Telescope/Cosmic Explorer experiments, and to probe other frontiers in fundamental physics.
Abstract: We outline the experimental concept and key scientific capabilities of AION (Atom Interferometer Observatory and Network), a proposed UK-based experimental programme using cold strontium atoms to search for ultra-light dark matter, to explore gravitational waves in the mid-frequency range between the peak sensitivities of the LISA and LIGO/Virgo/ KAGRA/INDIGO/Einstein Telescope/Cosmic Explorer experiments, and to probe other frontiers in fundamental physics. AION would complement other planned searches for dark matter, as well as probe mergers involving intermediate mass black holes and explore early universe cosmology. AION would share many technical features with the MAGIS experimental programme in the US, and synergies would flow from operating AION in a network with this experiment, as well as with other atom interferometer experiments such as MIGA, ZAIGA and ELGAR. Operating AION in a network with other gravitational wave detectors such as LIGO, Virgo and LISA would also offer many synergies.

256 citations

Journal ArticleDOI
TL;DR: In this article, the Lamb-Mossbauer factor and the center shift with temperature were combined with magnetic-susceptibility data on well-characterized LaCo${\mathrm{O}}_{3}$ in the 4.2-1200-K region.
Abstract: M\"ossbauer studies combined with magnetic-susceptibility data on well-characterized LaCo${\mathrm{O}}_{3}$ in the 4.2-1200-K region show that cobalt ions exist predominantly in the low-spin ${\mathrm{Co}}^{\mathrm{III}}$ state at low temperatures which transform partially to high-spin ${\mathrm{Co}}^{3+}$ ions up to 200 K. Above 200 K, ${\mathrm{Co}}^{3+}$ and ${\mathrm{Co}}^{\mathrm{III}}$ ion pairs transform to ${\mathrm{Co}}^{\mathrm{II}}$ and ${\mathrm{Co}}^{4+}$ pairs. At high temperatures, the population of ${\mathrm{Co}}^{3+}$ decreases significantly and completely disappears at the localized-electron-collective-electron transition temperature at 1210 K. The variations of the Lamb-M\"ossbauer factor and the center shift with temperature provide valuable information on the high-spin-low-spin equilibria, as well as on the nature of the phase transitions and symmetry changes in LaCo${\mathrm{O}}_{3}$. All these changes are reflected in the transport properties of LaCo${\mathrm{O}}_{3}$. There appears to be little doubt that the first-order localized-electron-collective-electron transition in LaCo${\mathrm{O}}_{3}$ is caused essentially by the change in entropy of the $d$ electrons.

255 citations

Journal ArticleDOI
TL;DR: In this paper, the binding energy scales of x-ray photoelectron spectrometers were calibrated for general analytical purposes using unmonochromated Al or Mg x-rays or monochromate Al x-rams.
Abstract: This international standard specifies a method for calibrating the binding energy scales of x-ray photoelectron spectrometers, for general analytical purposes, using unmonochromated Al or Mg x-rays or monochromated Al x-rays. It is only applicable to instruments that have an ion gun for sputter cleaning. This international standard further specifies a method to establish a calibration schedule, to test for the binding energy scale linearity at one intermediate energy, to confirm the uncertainty of the scale calibration at one low and one high binding energy value, to correct for small drifts of that scale and to define the expanded uncertainty of the calibration of the binding energy scale for a confidence level of 95%. This uncertainty includes contributions for behaviour observed in inter-laboratory studies but does not cover all of the defects that could occur. This international standard is not applicable to instruments with binding energy scale errors that are significantly non-linear with energy, to instruments operated in the constant retardation ratio mode at retardation ratios of <10, to instruments with a spectrometer resolution worse than 1.5 eV or to instruments requiring tolerance limits of ±0.03 eV or less. This international standard does not provide a full calibration check, which would confirm the energy measured at each addressable point on the energy scale and would have to be performed in accordance with the manufacturer's recommended procedures. © Crown Copyright 2001. Published by John Wiley & Sons, Ltd.

255 citations


Authors

Showing all 7655 results

NameH-indexPapersCitations
Rajesh Kumar1494439140830
Akhilesh Pandey10052953741
A. S. Bell9030561177
David R. Clarke9055336039
Praveen Kumar88133935718
Richard C. Thompson8738045702
Xin-She Yang8544461136
Andrew J. Pollard7967326295
Krishnendu Chakrabarty7999627583
Vinod Kumar7781526882
Bansi D. Malhotra7537519419
Matthew Hall7582724352
Sanjay K. Srivastava7336615587
Michael Jones7233118889
Sanjay Singh71113322099
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Performance
Metrics
No. of papers from the Institution in previous years
YearPapers
202315
202242
2021356
2020438
2019434
2018406