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The Journal of Physical Chemistry... Jun 2024We have measured the photodissociation of few-keV OD molecular ions into either D + O or O + D final products. The three-dimensional momentum imaging measurements of the...
We have measured the photodissociation of few-keV OD molecular ions into either D + O or O + D final products. The three-dimensional momentum imaging measurements of the light and massive fragments in coincidence were enabled by using an upgraded two-detector setup. In this work, we show that absorption of a single 790 or 395 nm photon excites the OD from its electronic ground state to the B state, which dissociates to the O(S) + D dissociation limit. To reach the other nearly degenerate dissociation limit, D + O(P), a unimolecular charge transfer, B to X , transition is required following the same photoexcitation. The measured branching ratio of these dissociation channels is a direct measure of the charge transfer transition probability. This measured probability as a function of energy above the dissociation limit agrees well with our calculations.
PubMed: 38922646
DOI: 10.1021/acs.jpclett.4c00649 -
Magma (New York, N.Y.) Jun 2024To review recent advances of artificial intelligence (AI) in enhancing the efficiency and throughput of the MRI acquisition workflow in neuroimaging, including planning,... (Review)
Review
OBJECT
To review recent advances of artificial intelligence (AI) in enhancing the efficiency and throughput of the MRI acquisition workflow in neuroimaging, including planning, sequence design, and correction of acquisition artifacts.
MATERIALS AND METHODS
A comprehensive analysis was conducted on recent AI-based methods in neuro MRI acquisition. The study focused on key technological advances, their impact on clinical practice, and potential risks associated with these methods.
RESULTS
The findings indicate that AI-based algorithms have a substantial positive impact on the MRI acquisition process, improving both efficiency and throughput. Specific algorithms were identified as particularly effective in optimizing acquisition steps, with reported improvements in workflow efficiency.
DISCUSSION
The review highlights the transformative potential of AI in neuro MRI acquisition, emphasizing the technological advances and clinical benefits. However, it also discusses potential risks and challenges, suggesting areas for future research to mitigate these concerns and further enhance AI integration in MRI acquisition.
PubMed: 38922525
DOI: 10.1007/s10334-024-01182-7 -
The Journal of Cell Biology Aug 2024From a statistical standpoint, individual cells are typically not independent experimental replicates. To test for differences in mean, cells from each experimental...
From a statistical standpoint, individual cells are typically not independent experimental replicates. To test for differences in mean, cells from each experimental sample can be averaged and each sample's average treated as an n of 1. Here, I outline how to determine how many cells to average per sample.
Topics: Microscopy; Humans; Cell Count; Animals
PubMed: 38922298
DOI: 10.1083/jcb.202401074 -
Journal of Synchrotron Radiation Jul 2024The High Energy Photon Source (HEPS) in Beijing achieved a beam energy of 6 GeV. This milestone enables groundbreaking advances in health sciences and various research...
The High Energy Photon Source (HEPS) in Beijing achieved a beam energy of 6 GeV. This milestone enables groundbreaking advances in health sciences and various research fields, promising new insights into biological and quantum processes.
PubMed: 38922291
DOI: 10.1107/S1600577524003874 -
Nanomaterials (Basel, Switzerland) Jun 2024The recombination of charge carriers at the interface between carrier transport layers such as nickel oxide (NiO) and the perovskite absorber has long been a challenge...
The recombination of charge carriers at the interface between carrier transport layers such as nickel oxide (NiO) and the perovskite absorber has long been a challenge in perovskite solar cells (PSCs). To address this issue, we introduced a polymer additive poly(vinyl butyral) into NiO and subjected it to high-temperature annealing to form a void-containing structure. The formation of voids is confirmed to increase light transmittance and surface area of NiO, which is beneficial for light absorption and carrier separation within PSCs. Experimental results demonstrate that the incorporation of the polymer additive helped to enhance the hole conductivity and carrier extraction of NiO with a higher Ni/Ni ratio. This also optimized the energy levels of NiO to match with the perovskite to raise the open-circuit voltage to 1.01 V. By incorporating an additional NiO layer beneath the polymer-modified NiO, the device efficiency was further increased as verified from the dark current measurement of devices.
PubMed: 38921930
DOI: 10.3390/nano14121054 -
Nanomaterials (Basel, Switzerland) Jun 2024Femtosecond high-intensity laser pulses at intensities surpassing 10 W/cm can generate a diverse range of functional surface nanostructures. Achieving precise control...
Femtosecond high-intensity laser pulses at intensities surpassing 10 W/cm can generate a diverse range of functional surface nanostructures. Achieving precise control over the production of these functional structures necessitates a thorough understanding of the surface morphology dynamics with nanometer-scale spatial resolution and picosecond-scale temporal resolution. In this study, we show that single XFEL pulses can elucidate structural changes on surfaces induced by laser-generated plasmas using grazing-incidence small-angle X-ray scattering (GISAXS). Using aluminium-coated multilayer samples we distinguish between sub-picosecond (ps) surface morphology dynamics and subsequent multi-ps subsurface density dynamics with nanometer-depth sensitivity. The observed subsurface density dynamics serve to validate advanced simulation models representing matter under extreme conditions. Our findings promise to open new avenues for laser material-nanoprocessing and high-energy-density science.
PubMed: 38921926
DOI: 10.3390/nano14121050 -
Nanomaterials (Basel, Switzerland) Jun 2024This study aims to enhance the optical and thermal properties of cesium-based perovskite nanocrystals (NCs) through surface passivation with organic sulfonate (or...
This study aims to enhance the optical and thermal properties of cesium-based perovskite nanocrystals (NCs) through surface passivation with organic sulfonate (or sulfonic acid) ligands. Four different phenylated ligands, including sodium β-styrenesulfonate (SbSS), sodium benzenesulfonate (SBS), sodium -toluenesulfonate (SPTS), and 4-dodecylbenzenesulfonic acid (DBSA), were employed to modify blue-emitting CsPbBrCl perovskite NCs, resulting in improved size uniformity and surface functionalization. Transmission electron microscopy and X-ray photoelectron spectroscopy confirmed the successful anchoring of sulfonate or sulfonic acid ligands on the surface of perovskite NCs. Moreover, the photoluminescence quantum yield increased from 32% of the original perovskite NCs to 63% of the SPTS-modified ones due to effective surface passivation. Time-resolved photoluminescence decay measurements revealed extended PL lifetimes for ligand-modified NCs, indicative of reduced nonradiative recombination. Thermal stability studies demonstrated that the SPTS-modified NCs retained nearly 80% of the initial PL intensity when heated at 60 °C for 10 min, surpassing the performance of the original NCs. These findings emphasize the optical and thermal stability enhancement of cesium-based perovskite NCs through surface passivation with suitable sulfonate ligands.
PubMed: 38921925
DOI: 10.3390/nano14121049 -
Nanomaterials (Basel, Switzerland) Jun 2024Aiming at the limitations of single-functionality, limited-applicability, and complex designs prevalent in current metasurfaces, we propose a terahertz multifunctional...
Aiming at the limitations of single-functionality, limited-applicability, and complex designs prevalent in current metasurfaces, we propose a terahertz multifunctional and multiband tunable metasurface utilizing a VO-metal hybrid structure. This metasurface structure comprises a top VO-metal resonance layer, a middle polyimide dielectric layer, and a gold film reflective layer at the bottom. This metasurface exhibits multifunctionality, operating independently of polarization and incident angle. The varying conductivity states of the VO layers, enabling the metasurface to achieve various terahertz functionalities, including single-band absorption, broadband THz absorption, and multiband perfect polarization conversion for linear (LP) and circularly polarized (CP) incident waves. Finally, we believe that the functional adaptability of the proposed metasurface expands the repertoire of options available for future terahertz device designs.
PubMed: 38921924
DOI: 10.3390/nano14121048 -
Nanomaterials (Basel, Switzerland) Jun 2024The hexagonal ferrite h-YbFeO grown on YSZ(111) by pulsed laser deposition is foreseen as a promising single multiferroic candidate where ferroelectricity and...
The hexagonal ferrite h-YbFeO grown on YSZ(111) by pulsed laser deposition is foreseen as a promising single multiferroic candidate where ferroelectricity and antiferromagnetism coexist for future applications at low temperatures. We studied in detail the microstructure as well as the temperature dependence of the magnetic properties of the devices by comparing the heterostructures grown directly on YSZ(111) (i.e., YbPt_Th0nm) with h-YbFeO films deposited on substrates buffered with platinum Pt/YSZ(111) and in dependence on the Pt underlayer film thickness (i.e., YbPt_Th10nm, YbPt_Th40nm, YbPt_Th55nm, and YbPt_Th70nm). The goal was to deeply understand the importance of the crystal quality and morphology of the Pt underlayer for the h-YbFeO layer crystal quality, surface morphology, and the resulting physical properties. We demonstrate the relevance of homogeneity, continuity, and hillock formation of the Pt layer for the h-YbFeO microstructure in terms of crystal structure, mosaicity, grain boundaries, and defect distribution. The findings of transmission electron microscopy and X-ray diffraction reciprocal space mapping characterization enable us to conclude that an optimum film thickness for the Pt bottom electrode is = 70 nm, which improves the crystal quality of h-YbFeO films grown on Pt-buffered YSZ(111) in comparison with h-YbFeO films grown on YSZ(111) (i.e., YbPt_Th0nm). The latter shows a disturbance in the crystal structure, in the up-and-down atomic arrangement of the ferroelectric domains, as well as in the Yb-Fe exchange interactions. Therefore, an enhancement in the remanent and in the total magnetization was obtained at low temperatures below 50 K for h-YbFeO films deposited on Pt-buffered substrates Pt/YSZ(111) when the Pt underlayer reached = 70 nm.
PubMed: 38921917
DOI: 10.3390/nano14121041 -
Nanomaterials (Basel, Switzerland) Jun 2024Identification of a natural-based sensitizer with optimal stability and efficiency for dye-sensitized solar cell (DSSC) application remains a challenging task....
Identification of a natural-based sensitizer with optimal stability and efficiency for dye-sensitized solar cell (DSSC) application remains a challenging task. Previously, we proposed a new class of sensitizers based on bio-nano hybrids. These systems composed of natural cyanidin dyes interacting with silver nanoclusters (NCs) have demonstrated enhanced opto-electronic and photovoltaic properties. In this study, we explore the doping of silver nanocluster within a cyanidin-Ag hybrid employing Density Functional Theory (DFT) and its time-dependent counterpart (TDDFT). Specifically, we investigate the influence of coinage metal atoms (Au and Cu) on the properties of the cyanidin-Ag system. Our findings suggest that cyanidin-AgAu and cyanidin-AgAuCu emerge as the most promising candidates for improved light harvesting efficiency, increased two-photon absorption, and strong coupling to the TiO surface. These theoretical predictions suggest the viability of replacing larger silver NCs with heterometallic trimers such as AgAu or AgAuCu, presenting new avenues for utilizing bio-nano hybrids at the surface for DSSC application.
PubMed: 38921910
DOI: 10.3390/nano14121034