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2022 • Proc. of SPIE Vol

Tissue Optics and Photonics II

Valery V Tuchin, Walter C Blondel, Zeev Zalevsky

The papers in this volume were part of the technical conference cited on the cover and title page. Papers were selected and subject to review by the editors and conference program committee. Some conference presentations may not be available for publication. Additional papers and presentation recordings may be available online in the SPIE Digital Library at SPIEDigitalLibrary. org.

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2022 • Advanced Photonics Research

Nanoscopy of Aluminum Plasmonic Cavities by Cathodoluminescence and Second Harmonic Generation

Tchiya Zar, Racheli Ron, Omer Shavit, Alon Krause, David Gachet, Adi Salomon

Herein, centrosymmetric aluminum plasmonic structures composed of triangular cavities are studied and their long‐range coupling by cathodoluminescence nanoscopy are visualized. Four different plasmonic structures containing the same subunit are studied. The plasmonic modes of the individual triangular subunits are localized at the triangle sides rather than at the vertices, in agreement with other studies. Yet, upon strong interaction between the cavities, a redistribution of the electromagnetic field is observed such that it delocalizes around the cavities in the form of a contour, providing a mode enhancement and a pronounced nonlinear response as observed by second harmonic generation. Comparison between plasmonic structures made of either silver or aluminum reveals that the metal dielectric function plays an important role in the interaction between the cavities. This work provides a rationale for …

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2022 •

Sexual deprivation induces a CRF independent stress response and decreases resistance to stressors in Drosophila via a subpopulation of Neuropeptide F receptor-expressing neurons

Galit Shohat-Ophir Julia Ryvkin, Anat Shmueli, Avi Jacob, Tali Shalit, Assa Bentzur, Bella Agranovich, Ifat Abramovich, Eyal Gottlieb, Dick R Nassel

2022 • Advanced Photonics Research

Coupled Molecular Emitters in Superstructures Interact with Plasmonic Nanoparticles

Daniel Beitner, Itai Carmeli, Zeev Zalevsky, Shachar Richter, Haim Suchowski

Using hyperspectral measurements, J‐aggregate nanorods of porphyrin molecules embedded in plasmonic Au nanoparticles arrays are studied. Measurements of J‐aggregate nanorods that cross onto a plasmonic array exhibit a shift in their absorption peak, and display weak coupling properties only for the embedded part. Furthermore, a significant thickness‐dependent redshift in the plasmonic resonance for the J‐aggregate clusters is observed. Such redshift is also dependent on the ratio of J‐aggregate in the plasmonic dipole interaction area, reaching values of up to 120 meV for ≈40% coverage. In addition, for large clusters of J‐aggregates, the plasmonic spectrum shows coupling behavior between the systems indicated by a small Rabi splitting. The findings are validated by a quasi‐static model based on the change of the dielectric environment around the embedded nanoparticles. Using the model, the …

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2022 • Advanced Materials Interfaces

Surface Interactions of Oxygen Suffice to P‐Dope the Halide Perovskites

Ansuman Halder, Anat Itzhak, Eli Rosh Hodesh, Shay Tirosh, David Cahen

Attempts to dope halide perovskites (HaPs) extrinsically have been mostly unsuccessful. Still, oxygen (O2) is an efficient p‐dopant for polycrystalline HaP films. To an extent, this doping is reversible, i.e., the films can be de‐doped by decreasing the O2 partial pressure. Here results are reported, aimed at understanding the mechanism of such reversible doping, as it has been argued that doping involves interaction of oxygen with defects inside bulk HaP. These experimental results clearly point out that O2‐surface interactions suffice to dope the bulk of the films. Such behavior fits what is known for other polycrystalline semiconductors, where surface charge transfer‐adducts can form and be removed. Thus, controlling the O2 partial pressure to which the HaP film is exposed, can, after proper encapsulation, achieve the desired bulk doping of the film.

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2022 • Advanced Functional Materials

Sulfur‐Treatment Passivates Bulk Defects in Sb2Se3 Photocathodes for Water Splitting

Rajiv Ramanujam Prabhakar, Thomas Moehl, Dennis Friedrich, Marinus Kunst, Sudhanshu Shukla, Damilola Adeleye, Vinayaka H Damle, Sebastian Siol, Wei Cui, Laxman Gouda, Jihye Suh, Yaakov R Tischler, Roel van de Krol, S David Tilley

Sb2Se3 has emerged as an important photoelectrochemical (PEC) and photovoltaic (PV) material due to its rapid rise in photoconversion efficiencies. However, Sb2Se3 has a complex defect chemistry, which reduces the maximum photovoltage. Thus, it is important to understand these defects and develop defect passivation strategies in Sb2Se3. A comprehensive investigation of the charge carrier dynamics of Sb2Se3 and the influence of sulfur treatment on its optoelectronic properties is performed using time‐resolved microwave conductivity (TRMC), photoluminescence (PL) spectroscopy, and low‐frequency Raman spectroscopy (LFR). The key finding in this work is that upon sulfur treatment of Sb2Se3, the carrier lifetime is increased by the passivation of deep defects in Sb2Se3 in both the surface region and the bulk, which is evidenced by increased charge carrier lifetime of TRMC decay dynamics, increased …

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2022 • Energy & Environmental Science

Light-induced beneficial ion accumulation for high-performance quasi-2D perovskite solar cells

Xiaomei Lian, Lijian Zuo, Bowen Chen, Biao Li, Haotian Wu, Shiqi Shan, Gang Wu, Xuegong Yu, Qi Chen, Liwei Chen, Deren Yang, David Cahen, Hongzheng Chen

Ion migration and subsequent accumulation at interfaces, driven by the built-in potential (Vbi), are intrinsic properties of halide perovskite solar cells (PVSCs), which mostly decrease device performance. To address this issue, we constructed favorable ion accumulation in perovskite solar cell by illumination to improve quasi-2D PVSCs performance. This design dramatically improves the photo-carrier collection and enables significant device performance improvement from 14.6% to 19.05%, one of the best results for quasi-2D PVSCs. We argue that the light-triggered favorable ion accumulation originates from 1) photo-induced quasi-fermi level splitting that compensates the Vbi, so as to avoid the ion accumulation that decreases Vbi, and 2) the light intensity distribution-induced uneven ion potential further drives the segregation of mobile ions towards favorable ion accumulation, decreasing any I- gradient between …

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2022 • Proc. of SPIE Vol

Characterization of second-harmonic generation in silver nanoparticles for spontaneous parametric down-conversion

Ariel Ashkenazy, Eliahu Cohen, Dror Fixler

Energy-time entangled photon pairs (EPPs), which are at the heart of numerous quantum light applications, are commonly generated in nonlinear crystals. Some highly sensitive quantum applications require the use of ultra-broadband entangled photons that cannot be generated in nonlinear crystals due to phase-matching requirements. Here, we investigate the possibility of using metallic nanoparticles (MNPs) as a means for generating entangled photons through spontaneous parametric down-conversion (SPDC). MNPs are known for their strong light-matter coupling at their localized surfaceplasmon resonance, and since the propagation length through them is negligible relative to optical wavelengths, we consider them as excellent candidates to serve as non-phase matched sources of ultra-broadband entangled photons.To that end, we report experimental results of classical-light second-harmonic generation …

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2022 • Proc. of SPIE Vol

Nanoscale Imaging, Sensing, and Actuation for Biomedical Applications XIX

Dror Fixler, Ewa M Goldys, Sebastian Wachsmann-Hogiu

Paper Numbering: A unique citation identifier (CID) number is assigned to each article in the Proceedings of SPIE at the time of publication. Utilization of CIDs allows articles to be fully citable as soon as they are published online, and connects the same identifier to all online and print versions of the publication. SPIE uses a seven-digit CID article numbering system structured as follows:▪ The first five digits correspond to the SPIE volume number.▪ The last two digits indicate publication order within the volume using a Base 36 numbering system employing both numerals and letters. These two-number sets start with 00, 01, 02, 03, 04, 05, 06, 07, 08, 09, 0A, 0B… 0Z, followed by 10-1Z, 20-2Z, etc. The CID Number appears on each page of the manuscript.

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2022 • Frontiers in Molecular Biosciences

Disrupting Cu trafficking as a potential therapy for cancer

Zena Qasem, Matic Pavlin, Ida Ritacco, Matan Y Avivi, Shelly Meron, Melanie Hirsch, Yulia Shenberger, Lada Gevorkyan-Airapetov, Alessandra Magistrato, Sharon Ruthstein

Copper is an essential trace element required for vital cell functions and the survival of all organisms, ranging from bacteria to humans (Burkhead et al., 2009; Gaggelli et al., 2009; Lutsenko, 2010). Owing to the ability of copper to cycle between two oxidation states [ie, Cu (I) and Cu (II)], copper ions serve as important catalytic cofactors in proteinlinked redox chemistry. Such proteins carry out fundamental biological functions and are required for proper cellular growth and development. Copper-dependent proteins are involved in a wide variety of biological processes. Therefore, copper deficiency in these enzymes and/or alterations in their functions often trigger disease states or physiopathological conditions. Although critical for proper cell functioning, copper ions can also act as potent cytotoxins (Bertinato and L’Abbe, 2004; Manto, 2014; Harrison and Dameron, 1999). Owing to its special redox chemistry, copper …

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2022 • s Note: MDPI stays neutral with regard to jurisdictional claims in published …, 2022

Simultaneous Noninvasive Detection and Therapy of Atherosclerosis Using HDL Coated Gold Nanorods. Diagnostics 2022, 12, 577

R Ankri, D Leshem-Lev, H Duadi, E Harari, M Motiei, E Hochhauser, EI Lev, D Fixler

Cardiovascular disease (CVD) is a major cause of death and disability worldwide. A real need exists in the development of new, improved therapeutic methods for treating CVD, while major advances in nanotechnology have opened new avenues in this field. In this paper, we report the use of gold nanoparticles (GNPs) coated with high-density lipoprotein (HDL)(GNP-HDL) for the simultaneous detection and therapy of unstable plaques. Based on the well-known HDL cardiovascular protection, by promoting the reverse cholesterol transport (RCT), injured rat carotids, as a model for unstable plaques, were injected with the GNP-HDL. Noninvasive detection of the plaques 24 h post the GNP injection was enabled using the diffusion reflection (DR) method, indicating that the GNP-HDL particles had accumulated in the injured site. Pathology and noninvasive CT measurements proved the recovery of the injured artery treated with the GNP-HDL. The DR of the GNP-HDL presented a simple and highly sensitive method at a low cost, resulting in simultaneous specific unstable plaque diagnosis and recovery.

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2022 • Chemical Science

Cu (II)-based DNA Labeling Identifies the Structural Link Between Activation and Termination in a Metalloregulator

Joshua Casto, Alysia Mandato, Lukas Hofmann, Idan Yakobov, Shreya Ghosh, Sharon Ruthstein, Sunil Saxena

Understanding the structural and mechanistic details of protein-DNA interactions that lead to cellular defence against toxic metal ions in pathogenic bacteria can lead to new ways of combating their virulence. Herein, we examine the Copper Efflux Regulator (CueR) protein, a transcription factor which interacts with DNA to generate proteins that ameliorate excess free Cu(I). We exploit site directed Cu(II) labeling to measure the conformational changes in DNA as a function of protein and Cu(I) concentration. Unexpectedly, the EPR data indicates that the protein can bend the DNA at high protein concentrations even in the Cu(I)-free state. On the other hand, the bent state of the DNA is accessed at a low protein concentration in the presence of Cu(I). Such bending enables the coordination of the DNA with RNA polymerase. Taken together, the results lead to a structural understanding of how transcription is activated in …

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2022 • Small

Improved Cycling Stability of LiNi0.8Co0.1Mn0.1O2 Cathode Material via Variable Temperature Atomic Surface Reduction with Diethyl Zinc

Arka Saha, Sarah Taragin, Sandipan Maiti, Tatyana Kravchuk, Nicole Leifer, Maria Tkachev, Malachi Noked

High‐Ni‐rich layered oxides [e.g., LiNixCoyMnzO2; x > 0.5, x + y + z = 1] are considered one of the most promising cathodes for high‐energy‐density lithium‐ion batteries (LIB). However, extreme electrode–electrolyte reactions, several interfacial issues, and structural instability restrict their practical applicability. Here, a shortened unconventional atomic surface reduction (ASR) technique is demonstrated on the cathode surface as a derivative of the conventional atomic layer deposition (ALD) process, which brings superior cell performances. The atomic surface reaction (reduction process) between diethyl‐zinc (as a single precursor) and Ni‐rich NMC cathode [LiNi0.8Co0.1Mn0.1O2; NCM811] material is carried out using the ALD reactor at different temperatures. The temperature dependency of the process through advanced spectroscopy and microscopy studies is demonstrated and it is shown that thin surface …

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2022 • Physical Chemistry Chemical Physics

The effects of thermal treatment and irradiation on the chemical properties of natural diamonds

Ira Litvak, Haim Cohen, Sharon Ruthstein, Yaakov Anker, Avner Cahana

The modification of nitrogen-contaminated diamonds into color-enhanced diamonds is usually achieved by irradiation and thermal treatment (annealing). These treatments affect nitrogen contamination chemical bonding, vacancy concentration, and atom orientation centers in the diamond lattice. In this study, natural diamonds were subjected to irradiation and thermal annealing color enhancement treatments to produce green, blue, and yellow fancy diamonds. The study followed the changes that occur during treatment relying on visual assessment, fluorescence, UV-vis, FTIR, and EPR spectroscopy to characterize paramagnetic centers. The results indicated that diamonds containing high levels of nitrogen contamination presented a relatively high carbon-centered radical concentration. Two paramagnetic groups with different g-values were found, namely, low g-value centers of 2.0017-2.0027 and high g-value …

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2022 • Springer, Cham

Regulation of Host Immunity by the Gut Microbiota

Hannah Partney, Nissan Yissachar

Constant exposure to diverse microorganisms has accompanied human evolution and continues to shape immunological development throughout life. In mucosal tissues, both innate and adaptive arms of the immune system are required to support healthy mutualistic interactions with the resident microbiota, while aggressively fighting pathogenic infections. Technological breakthroughs over the past decade facilitated groundbreaking discoveries that transformed our understanding of intestinal immunology and established the gut microbiota as a critical factor that shapes immunological development and function. Indeed, alterations to microbiota composition (dysbiosis) are associated with a wide array of human diseases, including autoimmune diseases, chronic inflammation, the metabolic syndrome, and cancer. In this chapter, we discuss fundamental concepts that underlie microbiota-immune system crosstalks …

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2022 • Physical Chemistry Chemical Physics

Electron transport via tyrosine-doped oligo-alanine peptide junctions: role of charges and hydrogen bonding

Cunlan Guo, Yulian Gavrilov, Satyajit Gupta, Tatyana Bendikov, Yaakov Levy, Ayelet Vilan, Israel Pecht, Mordechai Sheves, David Cahen

A way of modulating the solid-state electron transport (ETp) properties of oligopeptide junctions is presented by charges and internal hydrogen bonding, which affect this process markedly. The ETp properties of a series of tyrosine (Tyr)-containing hexa-alanine peptides, self-assembled in monolayers and sandwiched between gold electrodes, are investigated in response to their protonation state. Inserting a Tyr residue into these peptides enhances the ETp carried via their junctions. Deprotonation of the Tyr-containing peptides causes a further increase of ETp efficiency that depends on this residue’s position. Combined results of molecular dynamics simulations and spectroscopic experiments suggest that the increased conductance upon deprotonation is mainly a result of enhanced coupling between the charged C-terminus carboxylate group and the adjacent Au electrode. Moreover, intra-peptide hydrogen …

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2022 • The Journal of Physical Chemistry C

Direct Probing of Gap States and Their Passivation in Halide Perovskites by High-Sensitivity, Variable Energy Ultraviolet Photoelectron Spectroscopy

Levine Igal, Shimizu Kohei, Alberto Lomuscio, Michael Kulbak, Carolin Rehermann, Arava Zohar, Mojtaba Abdi-Jalebi, Baodan Zhao, Susanne Siebentritt, Fengshuo Zu, Norbert Koch, Antoine Kahn, Gary Hodes, Richard H Friend, David Cahen

Direct detection of intrinsic defects in halide perovskites (HaPs) by standard methods utilizing optical excitation is quite challenging, due to the low density of defects in most samples of this family of materials (≤ 1015 cm− 3 in polycrystalline thin films and≤ 1011 cm− 3 in single crystals, except melt-grown ones). While several electrical methods can detect defect densities< 1015 cm− 3, such as deep level transient spectroscopy (DLTS) or thermally stimulated current (TSC), they require preparation of ohmic and/or rectifying electrical contacts to the sample, which not only poses a challenge by itself in the case of HaPs but also may create defects at the contact− HaP interface and introduce extrinsic defects into the HaP. Here, we show that low-energy photoelectron spectroscopy measurements can be used to obtain directly the energy position of gap states in Br-based wide-bandgap (Eg> 2 eV) HaPs. By measuring HaP layers on both hole-and electron-contact layers, as well as single crystals without contacts, we conclude that the observed deep defects are intrinsic to the Br-based HaP, and we propose a passivation route via the incorporation of a 2D-forming ligand into the precursor solution.

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2022 • RSC Advances

Prospect of making XPS a high-throughput analytical method illustrated for a Cu x Ni 1− x O y combinatorial material library

Lucas CW Bodenstein-Dresler, Adi Kama, Johannes Frisch, Claudia Hartmann, Anat Itzhak, Regan G Wilks, David Cahen, Marcus Bär

2022 • Magnetochemistry 8 (1), 3, 2022

The Advantages of EPR Spectroscopy in Exploring Diamagnetic Metal Ion Binding and Transfer Mechanisms in Biological Systems

Shelly Meron, Yulia Shenberger, Sharon Ruthstein

Electron paramagnetic resonance (EPR) spectroscopy has emerged as an ideal biophysical tool to study complex biological processes. EPR spectroscopy can follow minor conformational changes in various proteins as a function of ligand or protein binding or interactions with high resolution and sensitivity. Resolving cellular mechanisms, involving small ligand binding or metal ion transfer, is not trivial and cannot be studied using conventional biophysical tools. In recent years, our group has been using EPR spectroscopy to study the mechanism underlying copper ion transfer in eukaryotic and prokaryotic systems. This mini-review focuses on our achievements following copper metal coordination in the diamagnetic oxidation state, Cu(I), between biomolecules. We discuss the conformational changes induced in proteins upon Cu(I) binding, as well as the conformational changes induced in two proteins involved in Cu(I) transfer. We also consider how EPR spectroscopy, together with other biophysical and computational tools, can identify the Cu(I)-binding sites. This work describes the advantages of EPR spectroscopy for studying biological processes that involve small ligand binding and transfer between intracellular proteins.

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2022 • Advanced Functional Materials

2D Pb‐Halide Perovskites Can Self‐Heal Photodamage Better than 3D Ones

Sigalit Aharon, Davide Raffaele Ceratti, Naga Prathibha Jasti, Llorenç Cremonesi, Yishay Feldman, Marco Alberto Carlo Potenza, Gary Hodes, David Cahen

Adding a 2D character to halide perovskite (HaP) active layers in ambient‐protected cells can improve their stability drastically, which is not obvious from the hydrophobicity of the large cations that force the HaP into a 2D structure. Results of two‐photon confocal microscopy are reported to study inherent photo‐stability of 2D Pb iodide HaPs in the interior of single crystals. Compared to 3D HaP crystals, 2D ones have higher photo‐stability and, under a few sun‐equivalent conditions, self‐heal efficiently after photo‐damage. Using both photoluminescence (PL) intensities (as function of time after photo‐damage) and spectra, self‐healing dynamics of 2D HaP (C4H9NH3)2PbI4, 2D/3D (C4H9NH3)2(CH3NH3)2Pb3I10 and 3D MAPbI3 are compared. Differences in response to photo‐damage and self‐healing ability from different degrees of photo‐damage are found between these HaPs. Based on the findings, a …

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2022 • s Note: MDPI stays neutral with regard to jurisdictional claims in published …, 2022

Phosphate-Trapping Liposomes for Long-Term Management of Hyperphosphatemia. Materials 2022, 15, 7779

C Tzror-Azankot, A Anaki, T Sadan, M Motiei, R Popovtzer

Hyperphosphatemia is a typical complication of end-stage renal disease, characterized by elevated and life-threatening serum phosphate levels. Hemodialysis does not enable sufficient clearance of phosphate, due to slow cell-to-plasma kinetics of phosphate ions; moreover, dietary restrictions and conventional treatment with oral phosphate binders have low success rates, together with adverse effects. Here, we developed a new concept of phosphate-trapping liposomes, to improve and prolong the control over serum phosphate levels. We designed liposomes modified with polyethylene glycol and encapsulated with the phosphate binder ferric citrate (FC liposomes). These liposomes were found to trap phosphate ions in their inner core, and thereby lower free phosphate ion concentrations in solution and in serum. The FC liposomes showed higher phosphate binding ability as phosphate concentrations increased. Moreover, these liposomes showed a time-dependent increase in uptake of phosphate, up to 25 h in serum. Thus, our findings demonstrate effective long-term phosphate trapping by FC liposomes, indicating their potential to reduce serum phosphate toxicity and improve current management of hyperphosphatemia.

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