Orders Of Magnitude In Intensity Research Articles

Semi-Quantitative MALDI Measurements of Blood-Based Samples for Molecular Diagnostics.

Accurate and precise measurement of the relative protein content of blood-based samples using mass spectrometry is challenging due to the large number of circulating proteins and the dynamic range of their abundances. Traditional spectral processing methods often struggle with accurately detecting overlapping peaks that are observed in these samples. In this work, we develop a novel spectral processing algorithm that effectively detects over 1650 peaks with over 3.5 orders of magnitude in intensity in the 3 to 30 kD m/z range. The algorithm utilizes a convolution of the peak shape to enhance peak detection, and accurate peak fitting to provide highly reproducible relative abundance estimates for both isolated peaks and overlapping peaks. We demonstrate a substantial increase in the reproducibility of the measurements of relative protein abundance when comparing this processing method to a traditional processing method for sample sets run on multiple matrix-assisted laser desorption/ionization-time of flight (MALDI-TOF) instruments. By utilizing protein set enrichment analysis, we find a sizable increase in the number of features associated with biological processes compared to previously reported results. The new processing method could be very beneficial when developing high-performance molecular diagnostic tests in disease indications.

Time resolved 3D interferometric imaging of a section of a negative leader with LOFAR

We have developed a three dimensional (3D) interferometric beamforming technique for imaging lightning flashes using Very-High Frequency (VHF) radio data recorded from several hundreds antennas with baselines up to 100~km as offered by the Low Frequency Array (LOFAR). The long baselines allow us to distinguish fine structures on the scale of meters while the large number of antennas allow us to observe processes that radiate at the same intensity as the background when using a time resolution that is close to the impulse-response time of the system, 100~ns. The new beamforming imaging technique is complementary to our existing impulsive imaging technique. We apply this new tool to the imaging of a four stepped negative leaders in two flashes. For one flash, we observe the dynamics of coronal flashes that are emitted in the stepping process. Additionally, we show that the intensity emitted in VHF during the stepping process follows a power-law over 4 orders of magnitude in intensity for four leaders in two different lightning storms.

Graphene Electric Field Sensor Enables Single Shot Label-Free Imaging of Bioelectric Potentials.

The measurement of electrical activity across systems of excitable cells underlies current progress in neuroscience, cardiac pharmacology, and neurotechnology. However, bioelectricity spans orders of magnitude in intensity, space, and time, posing substantial technological challenges. The development of methods permitting network-scale recordings with high spatial resolution remains key to studies of electrogenic cells, emergent networks, and bioelectric computation. Here, we demonstrate single-shot and label-free imaging of extracellular potentials with high resolution across a wide field-of-view. The critically coupled waveguide-amplified graphene electric field (CAGE) sensor leverages the field-sensitive optical transitions in graphene to convert electric potentials into the optical regime. As a proof-of-concept, we use the CAGE sensor to detect native electrical activity from cardiac action potentials with tens-of-microns resolution, simultaneously map the propagation of these potentials at tissue-scale, and monitor their modification by pharmacological agents. This platform is robust, scalable, and compatible with existing microscopy techniques for multimodal correlative imaging.

Improvement of quality and stability of MAPbI3 films grown by post annealing under high pressure argon atmosphere

Organic-inorganic hybrid perovskite MAPbI3 films with large grain size and excellent photoelectric properties are obtained by annealing the precursors at Ar atmosphere with pressure up to 10 MPa. In comparing to the film annealing at Ar with 0.1 MPa, 4 times lager grains are observed with the film annealing at the Ar atmosphere with the pressure of 6 MPa. The structural stability in respect to temperature is confirmed by the temperature dependence of x-ray diffraction. The band gap of MAPbI3 films may be adjusted by varying the annealing pressure. There is one order of magnitude in intensity of photoluminescence (PL) due to annealing at the Ar atmosphere with high pressure, even the intensity of PL increases with increasing the temperature up to 35 °C. Post annealing with high atmosphere pressure may be a new method in fabricating high performance MAPbI3 films.

Beam Modulation for Aberration Control and Signal Enhancement in Tip-Enhanced Raman Spectroscopy.

Tip-enhanced Raman spectroscopy (TERS) provides the sensitivity required to obtain the vibrational fingerprint of few molecules. While single molecule detection has been demonstrated in UHV experiments, the sensitivity of the technique in ambient, liquid and electrochemical conditions is still limited. In this work, we present a new strategy to increase the signal-to-noise in TERS by spatial light modulation. We iteratively optimize the phase of the excitation beam employing two different feedback mechanisms. In one optimization protocol, we monitor the spectral changes upon aberration correction and tight far-field focusing. In a second protocol, we use a phase-optimization strategy where TER spectra are directly used for feedback. Far-field tight focusing results in average signal enhancements of a factor of 3.5 in air and has no impact on TER signals obtained from solid/liquid interfaces. Using the TER spectrum as direct feedback, we obtain average signal enhancements between a factor of 2.6 in liquid and 4.3 in air. In individual cases, some bands increase by more than one order of magnitude in intensity upon spatial light modulation. Importantly, phase modulation in addition allowed the retrieval of bands that were initially not discernible from the noise. The proposed beam-modulation strategy can be easily implemented in existing TERS instruments and can help to push the detection limit of the technique in applications where the signal-to-noise level is low.

Model-independent inference of laser intensity

An ultrarelativistic electron beam passing through an intense laser pulse emits radiation around its direction of propagation into a characteristic angular profile. Here we show that measurement of the variances of this profile in the planes parallel and perpendicular to the laser polarization, and the mean initial and final energies of the electron beam, allows the intensity of the laser pulse to be inferred in way that is independent of the model of the electron dynamics. The method presented applies whether radiation reaction is important or not, and whether it is classical or quantum in nature, with accuracy of a few per cent across three orders of magnitude in intensity. It is tolerant of electron beams with broad energy spread and finite divergence. In laser-electron beam collision experiments, where spatiotemporal fluctuations cause alignment of the beams to vary from shot to shot, this permits inference of the laser intensity at the collision point, thereby facilitating comparisons between theoretical calculations and experimental data.

Boosted acceleration of protons by tailored ultra-thin foil targets

We report on a detailed experimental and numerical study on the boosted acceleration of protons from ultra-thin hemispherical targets utilizing multi-Joule short-pulse laser-systems. For a laser intensity of 1 × 1020 W/cm2 and an on-target energy of only 1.3 J with this setup a proton cut-off energy of 8.5 MeV was achieved, which is a factor of 1.8 higher compared to a flat foil target of the same thickness. While a boost of the acceleration process by additionally injected electrons was observed for sophisticated targets at high-energy laser-systems before, our studies reveal that the process can be utilized over at least two orders of magnitude in intensity and is therefore suitable for a large number of nowadays existing laser-systems. We retrieved a cut-off energy of about 6.5 MeV of proton energy per Joule of incident laser energy, which is a noticeable enhancement with respect to previous results employing this mechanism. The approach presented here has the advantage of using structure-wise simple targets and being sustainable for numerous applications and high repetition rate demands at the same time.

Radiation Effects on Satellites During Extreme Space Weather Events

AbstractHigh‐energy trapped electrons in the Van Allen belts pose a threat to the survivability of orbiting spacecraft. Two key radiation effects are total ionizing dose and displacement damage dose in components and materials, both of which cause cumulative and largely irreversible damage. During an extreme space weather event, trapped electron fluxes in the Van Allen belts can increase by several orders of magnitude in intensity, leading to an enhanced risk of satellite failure. We use extreme environments generated by modeling and statistical analyses to estimate the consequences for satellites in terms of the radiation effects described above. A worst‐case event could lead to significant losses in power generating capability—up to almost 8%—and cause up to four years' worth of ionizing dose degradation, leading to component damage and a life‐shortening effect on satellites. The consequences of such losses are hugely significant given our increasing reliance on satellites for a vast array of services, including communication, navigation, defense, and critical infrastructure.

Photophysical Model for Non-Exponential Relaxation Dynamics in Hybrid Perovskite Semiconductors

The photoluminescence (PL) decay of hybrid halide perovskite single crystals (MAPbX3, MA = CH3NH3+, Pb = Pb2+, X = Br–, and I–) is measured over 4 orders of magnitude in intensity over the time scales of 100s of nanoseconds to a few microseconds. This long PL decay is non-exponential, suggesting the presence of a distribution of carrier relaxation times. Spectro-temporal studies show that the emission peak red-shifts with increasing time. The physics of this problem is closely related to donor–acceptor pair recombination in crystalline semiconductors and recombination in a-Si:H. Based on these models, we present a simple model to account for the recombination dynamics in the perovskite systems. This model also accounts for the fluence dependence of the recombination kinetics. In this model, a fraction of the photogenerated electrons and holes are trapped in localized states. The electrons tunnel to the hole sites for recombination. The broad distribution of lifetimes is a consequence of the fact that the ...

Elimination of X-Ray Diffraction through Stimulated X-Ray Transmission.

X-ray diffractive imaging with laterally coherent x-ray free-electron laser (XFEL) pulses is increasingly utilized to obtain ultrafast snapshots of matter. Here we report the amazing disappearance of single-shot charge and magnetic diffraction patterns recorded with resonantly tuned, narrow bandwidth XFEL pulses. Our experimental results reveal the exquisite sensitivity of single-shot charge and magnetic diffraction patterns of a magnetic film to the onset of field-induced stimulated elastic x-ray forward scattering. The loss in diffraction contrast, measured over 3 orders of magnitude in intensity, is in remarkable quantitative agreement with a recent theory that is extended to include diffraction.

Experimental Bounds on Classical Random Field Theories

Alternative theories to quantum mechanics motivate important fundamental tests of our understanding and descriptions of the smallest physical systems. Here, using spontaneous parametric downconversion as a heralded single-photon source, we place experimental limits on a class of alternative theories, consisting of classical field theories which result in power-dependent normalized correlation functions. In addition, we compare our results with standard quantum mechanical interpretations of our spontaneous parametric downconversion source over an order of magnitude in intensity. Our data match the quantum mechanical expectations, and do not show a statistically significant dependence on power, limiting quantum mechanics alternatives which require power-dependent autocorrelation functions.

Cosmic rays around1018eV: Implications of contemporary measurements on the origin of the ankle feature

The impressive power-law decay of the energy spectrum of cosmic rays over more than thirty orders of magnitude in intensity and for energies ranging over eleven decades between $\simeq 10^9 $eV and $\simeq 10^{20} $eV is actually dotted with small irregularities. These irregularities are highly valuable for uncovering and understanding the modes of production and propagation of cosmic rays. They manifest themselves through changes in the spectral index characterising the observed power laws. One of these irregularities, known as the \textit{ankle}, is subject to conflicting interpretations for many years. If contemporary observations characterising it have shed new lights, they are still far from being able to deliver all the story. The purpose of this contribution is to give an overview of the physics of cosmic rays in the energy range where the transition between Galactic and extragalactic cosmic rays is expected to occur, and to deliver several lines of thought about the origin of the ankle.

Convective and shear-induced turbulence in the deep Kane Gap

[1] The boundary layer above a 4569 m deep slope in the near-equatorial N-Atlantic Ocean Kane Gap, a throughflow for Antarctic Bottom Water (AABW), is characterized by two distinct turbulent regimes that differ by an order of magnitude in intensity depending on the direction of throughflow. During southward and downward flow, vertical mixing is vigorous. This is inferred from high-resolution temperature observations between 6 and 132 m above the bottom. For a representative case study of 2 days, average values are found for dissipation rate of e?=?2.1?±?1 × 10-9 W kg-1 and eddy diffusivity of Kz?=?7?±?4 × 10-4 m2 s-1. The mixing is across relatively large vertical overturns. During northward and upward flow, smaller overturns are more horizontal as in stratified shear flow (with representative 2 day mean e?=?6?±?3 × 10-11 W kg-1, Kz?=?4?±?2 × 10-5 m2 s-1). Stratification is approximately the same during both flow directions. Although the different turbulence regimes are partially associated with frictional boundary layers of large-scale flows above sloping topography, but not with those over flat bottoms, and partially with flow across a hill-promontory, internal waves are a dominant process in promoting turbulence. In addition, internal waves are observed to push stratification toward the bottom thereby importantly contributing to the mixing of AABW.

Poisson-spot intensity reduction with a partially transparent petal-shaped optical mask

The presence of a Poisson spot inside a shadow region can best be described as the consequence of constructive interference of light waves diffracted on the edge of the obstruction where its central position can be determined by the symmetry of the object. More recently, the elimination of this spot has received attention in the fields of particle physics, high-energy lasers, astronomy, and lithography. The desired level of intensity suppression is dependent on the type of light source and the field of application. In this paper, we introduce a novel, partially transparent petaled mask shape that suppresses the bright spot by up to ten orders of magnitude in intensity at optical ranges, with potential powerful applications in many of the above fields. The optimization technique formulated in this design can identify mask shapes having partial transparency only near the petal tips.

Dimensional dependence of the energy transfer in MBE grown MnS layers

MBE grown MnS layers with different thicknesses have been studied by time resolved photoluminescence spectroscopy. The temporal evolution of the internal Mn 2+ (3d 5) luminescence is measured over 3 orders of magnitude in intensity. The decay curves obtained reveal a surprising but distinct dependence on the layer thickness with longer lifetime than thinner layers. The observed non-exponential behavior of those time transients can be well described by an energy diffusion model within the 3d states of the manganese subsystem and a subsequent dipole–dipole energy transfer to radiationless centers.

Energy Transfer and Dynamics of the Mn 3d5 Luminescence in Low Dimensional (Zn,Mn)S Nanostructures

) luminescenceis measured over 4 orders of magnitude in intensity. The decay behavior shows a clear dependenceon the morphology of the nanostructure, in particular, on the ratio between the average Mn ion -killer center distance and the characteristic lateral size of the nanostructure. The non-exponentialtransients observed can be well described in the framework of a Forster-transfer at reduced dimen-sionality. We present an important step in resolving a longstanding controversy in the literatureregarding the lifetime of the internal Mn

Dimensional dependence of the dynamics of theMn3d5luminescence in (Zn, Mn)S nanowires and nanobelts

ZnS nanostructures of different morphologies, i.e., nanowires and nanobelts, have been ion implanted with Mn and subsequently annealed to obtain ${\mathrm{Zn}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{S}$ nanostructures. The Mn content $x$ was adjusted to lie in the range from $4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}6}%$ to 4% corresponding to a variation of the mean Mn-Mn distance between about 200 and $2\phantom{\rule{0.3em}{0ex}}\mathrm{nm}$, respectively. The ${\mathrm{Zn}}_{1\ensuremath{-}x}{\mathrm{Mn}}_{x}\mathrm{S}$ nanowires have been studied by photoluminescence spectroscopy. The yellow Mn luminescence band indicates that the ${\mathrm{Mn}}^{2+}$ ions are incorporated on cation lattice sites replacing Zn. The temporal evolution of this internal ${\mathrm{Mn}}^{2+}(3{d}^{5})$ luminescence is measured over 4 orders of magnitude in intensity. The decay behavior shows a clear dependence on the morphology of the nanostructure, in particular, on the ratio between the average Mn ion-killer center distance and the characteristic lateral size of the nanostructure. If the mean Mn-Mn distance is comparable to or smaller than the average Mn ion-killer center distance in the nanostructures, then concentration quenching of the Mn luminescence occurs similar to bulk. The nonexponential transients observed can be well described in the framework of a modified F\orster model at reduced dimensionality. The photoluminescence (PL) behavior of the nanowires loses its one-dimensional character when the mean Mn ion-killer center distance becomes much smaller than the wire diameter. In contrast, the temporal PL behavior of the nanobelts is only purely two dimensional in this case and is of intermediate character between one dimensional and two dimensional otherwise.

Quantitative description of the temporal behavior of the internalMn3d5luminescence in ensembles ofZn0.99Mn0.01Squantum dots

We present an important step in resolving a long-standing controversy regarding the lifetime of the internal ${\mathrm{Mn}}^{2+}$ $3{d}^{5}$ emission in $\mathrm{ZnS}$ nanoparticles. Transients of the luminescence have been measured over more than five orders of magnitude in intensity, and in the time slot from $50\phantom{\rule{0.3em}{0ex}}\mathrm{ns}$ to $20\phantom{\rule{0.3em}{0ex}}\mathrm{ms}$. We show that the nonexponential decay behavior of the internal $3{d}^{5}$ luminescence of ensembles of ${\mathrm{Zn}}_{0.99}{\mathrm{Mn}}_{0.01}\mathrm{S}$ quantum dots is a result of the killer center statistics within the dot ensemble, and thus an intrinsic effect of the Mn-doped II-VI nanoparticles.

Use of an integrated MS – multiplexed MS/MS data acquisition strategy for high‐coverage peptide mapping studies

Liquid chromatography/mass spectrometry (LC/MS) peptide maps have become a basic tool for characterizing proteins of biological and pharmaceutical interest. The ability to generate reproducible maps with high protein sequence coverage is a central goal of methods development. We have applied a recently developed analytical approach (termed LC/MS(E)) to LC/MS peptide mapping. Using the LC/MS(E) approach, the mass detector alternates between a low-energy scanning mode (MS) for accurate mass peptide precursor identification, and an elevated-energy mode (MS(E)) for generation of accurate mass multiplex peptide fragmentation data. In this paper, we evaluate this analytical approach against a tryptic digest of yeast enolase. From the low-energy data, high peptide map coverage (98% of sequence from peptides >3 amino acids) was reproducibly obtained. The MS signal for essentially equimolar peptides varied over 2 orders of magnitude in intensity, and peptide intensities could be precisely and reproducibly measured. Using the temporal constraint that MS(E) peptide fragment ions exhibit chromatographic profiles that parallel the precursor ions that generated them, we were able to produce accurate mass time-resolved MS/MS information for all enolase peptides with sufficient abundance to produce a detectable fragment ion.

Systematic study of the dynamics of triplet exciton transfer between conjugated host polymers and phosphorescent iridium (III) guest emitters

A systematic study on the triplet exciton transfer between phosphorescent guest emitters and conjugated host polymers has been performed by means of fac-tris[2-(2-pyridinyl-kN)(5-(3,4-bis(2-methylpropyloxy)phenyl) phenyl)-kC]-iridium(III) [Ir-SC4] blended into three conjugated host polymers featuring higher, lower, and resonate triplet levels compared to the phosphorescent emitter, respectively. Here, the guest emission decay was measured over seven orders of magnitude in intensity after both optical and electrical excitation using nanosecond gated spectroscopy. Strongly dispersive decays are observed if the guest triplet energy level exceeds that of the host, which we discuss in terms of a guest host distance distribution. Hereby design rules for the synthesis of guest emitters emerge. Considering the reverse situation, i.e., the guest triplet level is lower than that of the host, almost no lifetime quenching of the guest emission is observed, but there is an additional delayed emission contribution of order ${10}^{\ensuremath{-}5}$. Several experimental findings, such as electric field quenching experiments and decay kinetics, indicate a charge transfer state between the guest metal and the host polymer rather than the late arriving of host polymer triplet excitons at the dopant sites as origin of this kind of delayed luminescence.