A comparison between centralized and asynchronous federated learning approaches for survival outcome prediction using clinical and PET data from non-small cell lung cancer patients.

BACKGROUND AND OBJECTIVE: Survival analysis plays an essential role in the medical field for optimal treatment decision-making. Recently, survival analysis based on the deep learning (DL) approach has been proposed and is demonstrating promising results. However, developing an ideal prediction model requires integrating large datasets across multiple institutions, which poses challenges concerning medical data privacy. METHODS: In this paper, we propose FedSurv, an asynchronous federated learning (FL) framework designed to predict survival time using clinical information and positron emission tomography (PET)-based features. This study used two datasets: a public radiogenic dataset of non-small cell lung cancer (NSCLC) from the Cancer Imaging Archive (RNSCLC), and an in-house dataset from the Chonnam National University Hwasun Hospital (CNUHH) in South Korea, consisting of clinical risk factors and F-18 fluorodeoxyglucose (FDG) PET images in NSCLC patients. Initially, each dataset was divided into multiple clients according to histological attributes, and each client was trained using the proposed DL model to predict individual survival time. The FL framework collected weights and parameters from the clients, which were then incorporated into the global model. Finally, the global model aggregated all weights and parameters and redistributed the updated model weights to each client. We evaluated different frameworks including single-client-based approach, centralized learning and FL. RESULTS: We evaluated our method on two independent datasets. First, on the RNSCLC dataset, the mean absolute error (MAE) was 490.80±22.95 d and the C-Index was 0.69±0.01. Second, on the CNUHH dataset, the MAE was 494.25±40.16 d and the C-Index was 0.71±0.01. The FL approach achieved centralized method performance in PET-based survival time prediction and outperformed single-client-based approaches. CONCLUSIONS: Our results demonstrated the feasibility and effectiveness of employing FL for individual survival prediction in NSCLC patients, using clinical information and PET-based features.

Sonophotocatalytic water splitting by BaTiO3@SrTiO3 core shell nanowires.

Sonophotocatalysis has garnered significant attention due to its potential to enhance advanced oxidation processes, particularly water splitting, by employing materials with combined sonocatalytic and photocatalytic properties. In this study, we synthesized and investigated core-shell BaTiO3@SrTiO3 nanowires (BST NWs) with varying Sr/Ba molar ratios (2.5:7.5, 5.0:5.0, 7.5:2.5 mM, denoted as BST-1, BST-2, and BST-3, respectively) as catalysts for hydrogen production through water splitting. The piezoelectric nanowires demonstrated hydrogen evolution via both sonocatalysis and photocatalysis. In the sonophotocatalysis process, the ultrasonic vibration induced mechanical forces on the BST nanowires, thereby establishing a built-in electric field. This built-in electric field facilitated the effective separation of photo-generated charge carriers and prolonged their lifetimes, leading to a synergistic enhancement of hydrogen evolution. The pristine BaTiO3 and SrTiO3 nanowires exhibited relatively low hydrogen evolution rates (HER) of 7.0 and 6.0 µmol·g-1min-1, respectively. In contrast, the core-shell nanowires exhibited a substantial improvement in the hydrogen evolution rate. The HER increased with the addition of Sr, and BST-1, BST-2, and BST-3 achieved HERs of 12.0, 13.5, and 18.0 µmol·g-1min-1, respectively. The superior performance of BST-3 nanowires can be attributed to their highest piezoelectric potential and largest surface area. Additionally, BST-3 nanowires demonstrated remarkable stability over multiple cycles, validating their practical applicability as efficient photocatalysts.

Cobalt-molybdenum-selenide nanoflowers for bifunctional visible light photocatalysis.

The renewability and zero carbon emissions of hydrogen make it a promising clean energy resource to meet future energy demands. Owing to its benefits, photocatalytic water-splitting has been extensively investigated for hydrogen production. However, the low efficiency poses a serious challenge to its implementation. Herein, we attempted to synthesize bimetallic transition metal selenides, namely Co/Mo/Se (CMS) photocatalysts, with varying atomic compositions (CMSa, CMSb, and CMSc) and investigated their photocatalytic water splitting efficiencies. The observed hydrogen evolution rates were as follows: 134.88 µmol g-1 min-1 for CoSe2, 145.11 µmol g-1 min-1 for MoSe2, 167.31 µmol g-1 min-1 for CMSa, 195.11 µmol g-1 min-1 for CMSb, and 203.68 µmol g-1 min-1 for CMSc. Hence, we deemed CMSc to be the most potent photocatalytic alternative among the compounds. CMSc was also tested for its efficiency towards degradation of triclosan (TCN), and results substantiated that CMSc succeeded degrading 98% TCN while CMSa and b were able to degrade 80 and 90% TCN respectively-the attained efficiency being exponentially higher than CoSe2 and MoSe2 taken for comparative analysis in addition to complete degradation of the pollutants leaving no harmful intermediaries during the process. Thus, CMSc shall be identified as a highly potential photocatalyst with respect to both environmental and energy applications.

Carbon-Based Ternary Nanocomposite: Bullet Type ZnO-SWCNT-CuO for Substantial Solar-Driven Photocatalytic Decomposition of Aqueous Organic Contaminants.

A facile two-step synthesis of ternary hetero-composites of ZnO, CuO, and single-walled carbon nanotubes (SWCNTs) was developed through a recrystallization process followed by annealing. A series of nanocomposites were prepared by varying the weight ratio of copper(II) acetate hydrate and zinc(II) acetate dihydrate and keeping the weight ratio of SWCNTs constant. The results revealed the formation of heterojunctions (ZnO-SWCNT-CuO, ZSC) of three crystal structures adjacent to each other, forming a ternary wurtzite-structured nanoparticles along with defects. Enhanced charge separation (electron-hole pairs), reduced band gap, defect-enhanced specific surface area, and promoted oxidation potential were key factors for the enhanced photocatalytic activity of the ternary nanocomposites. OH• radicals were the main active species during dye degradation, and O2-• and h+ were also involved to a lesser extent. A type II heterojunction mechanism approach is proposed based on the charge carrier migration pattern. Among the synthesized nanocomposites, the sample prepared using copper(II) acetate hydrate and zinc(II) acetate dihydrate in a 1: 9 ratio (designated a ZSC3) showed the highest photocatalytic activity. ZSC3 achieved 99.2% photodecomposition of methylene blue in 20 min, 94.1% photodecomposition of Congo red in 60 min, and 99.6% photodecomposition of Rhodamine B in 40 min under simulated sunlight. Additionally, ZSC3 showed excellent reusability and stability, maintaining 96.7% of its activity even after five successive uses. Based on overall results, the ZSC sample was proposed as an excellent candidate for water purification applications.

Zinc iron selenide nanoflowers anchored g-C3N4 as advanced catalyst for photocatalytic water splitting and dye degradation.

Hydrogen has been considered as a promising clean energy source owing to its renewability and zero carbon emission. Accordingly, photocatalytic water splitting has drawn much attention as a key green technology of producing hydrogen. However, it has remained as a great challenge due to the low production rate and expensive constituents of photocatalytic systems. Herein, we synthesised nanostructures consisting of transition metal selenide and g-C3N4 for photocatalytic water splitting reaction. They include ZnSe, FeSe2, Zn/FeSe2 and ZnFeSe2 nanoflowers and a nanocomposite made of Zn/FeSe2 and g-C3N4. Hydrogen evolution rates in the presence of ZnSe, FeSe2, Zn/FeSe2 and ZnFeSe2 photocatalysts were measured as 60.03, 128.02, 155.11 and 83.59 µmolg-1 min-1, respectively. On the other hand, with the nanocomposite consisting of Zn/FeSe2 and g-C3N4, the hydrogen and oxygen evolution rates were significantly enhanced up to 202.94 µmol g-1min-1 and 90.92 µmol g-1min-1, respectively. The nanocomposite was also examined as a photocatalyst for degradation of rhodamine B showing that it photodegrades the compound two times faster compared to pristine Zn/FeSe2 nanoflowers without g-C3N4. Our study suggests the nanocomposite of Zn/FeSe2 and g-C3N4 as a promising photocatalyst for energy and environmental applications.

Photocatalytic degradation of tetracycline using hybrid Ag/Ag2S@BiOI nanowires: Degradation mechanism and toxicity evaluation.

The wide use of antibiotics has caused their continual release and persistence in the eco-system, subsequently giving birth to antibiotic resistant bacterial species in the aquatic environment, thereby necessitating immediate and efficient remediation of the contaminated environment. In the present study, we synthesized Ag/Ag2S@BiOI nanowires with an average diameter of ∼150 nm and length of 3-5 µm using a hydrothermal method and employed them as photocatalysts for photocatalytic degradation of tetracycline as a model antibiotic. The nanowire achieved nearly complete degradation of tetracycline (∼99%) within 60 min at the optimal condition of 100 mg/L TC concentration and pH 2. The degradation followed pseudo-first order kinetics, with a rate constant of 0.06228 min- 1. Our toxicity tests showed that the nanowire has negligible toxicity towards PBMC cells, suggesting it as a promising photocatalyst.

Highly efficient visible light photocatalysis of Nix Zn1-x Fe2O4 (x= 0, 0.3, 0.7) nanoparticles: Diclofenac degradation mechanism and eco-toxicity.

Pharmaceuticals and personal care products occupy a predominant position with respect to both utility and release into the ecosystem, thereby contributing to environmental pollution at alarming rates. Of the several methods identified to minimize the concentration of PPCPs, nanomaterial based photocatalysis seems to be a potential alternative for it being highly economical and eco-friendly. In this study, we synthesized Nickel zinc ferrite (Ni-ZF) [Nix Zn1-x Fe2O4 (x = 0, 0.3, 0.7)] nanoparticles with an average diameter of ∼400 nm by a co-precipitation method towards diclofenac degradation. The composite showed greater degrees of crystallinity devoid of any impurities. Nearly complete DCF degradation (∼99%) was achieved after 50 min reaction time with the nanoparticles at pH 7 for an initial DCF concentration of 50 mg/L. The degradation process followed a pseudo first-order rate law with the rate constant of 0.1657 min- 1. Microbial toxicity and phytotoxicity studies demonstrated negligible toxicity imposed by the contaminated water treated with the prepared composite, suggesting it as a promising photocatalyst benefitting in all aspects.

Improved visible-light-driven photocatalytic removal of Bisphenol A using V2O5/WO3 decorated over Zeolite: Degradation mechanism and toxicity.

WO3/Zeolite/V2O5 (TZV) composite synthesized through co-precipitation was used for the degradation of Bisphenol-A (BpA). XRD and Raman spectra were employed to ascertain the crystallinity of the composite. The pristine nature of the compound without any free particles over the zeolite surface was established through FESEM, thus, substantiating the composite character of the material. The enhancement in activity after doping with WO3 was ascertained by DRS-UV. Photocatalytic degradation studies clearly established the superiority of TZV 10 over bare V2O5. Complete BpA degradation (100%) was attained at 50 min of incubation with 0.75 g/L TZV-10 in acidic medium (pH 3) for an initial BpA concentration of 100 mg/L. HPLC-MS/MS analysis was used to decipher the degradation pathway. The catalyst was stable even after 9 cycles. Phytotoxicity studies and lake water treatment results proved the environmental efficiency of the synthesized material.

Highly efficient visible light driven photocatalytic activity of zinc/ferrite: Carbamazepine degradation, mechanism and toxicity assessment.

In this present study, spherical shaped zinc ferrite (Zn/Fe2O4) was prepared as uniformly sized (65 ± 0.5 nm) nanoparticles with band gap (2.00 eV) in a visible light regime and employed for the photocatalytic degradation of carbamazepine (CBZ). The doping of Zn decreased the band gap (from 2.00 to 1.98 eV) and enhanced the absorption of visible light. Zinc doping also induced effective separation of photogenerated carriers and subsequent charge migration to the surface of the Zn/Fe2O4 nanoparticle. On account of the advantages of the material, a high removal efficiency (~ 100%) of CBZ through photocatalytic degradation was achieved. Kinetics of CBZ degradation follows a pseudo first-order with the rate constant 0.0367 min-1. In-vitro and in-vivo toxicity of the nanoparticles were examined promoting the environmental implications.

Nickel decorated manganese oxynitride over graphene nanosheets as highly efficient visible light driven photocatalysts for acetylsalicylic acid degradation.

In this work, we prepared nanocomposites of nickel-decorated manganese oxynitride on graphene nanosheets and demonstrated them as photocatalysts for degradation of acetylsalicylic acid (ASA). The catalyst exhibited a high degradation efficiency over ASA under visible light irradiation and an excellent structural stability after multiple uses. Compared to manganese oxide (MnO) and manganese oxynitride (MnON) nanoparticles, larger specific surface area and smaller band gap were observed for the nanocomposite accounting for the enhanced photocatalytic efficiency. Besides the compositional effect of the catalyst, we also examined the influence of various experimental parameters on the degradation of ASA such as initial concentration, catalyst dose, initial pH and additives. The best performance was obtained for the nanocomposite when the catalyst dose was 10 mg/mL and the initial pH 3. Detection of intermediates during photocatalysis showed that ASA undergoes hydroxylation, demethylation, aromatization, ring opening, and finally complete mineralization into CO2 and H2O by reactive species. For practical applications as a photocatalyst, cytotoxicity of the nanocomposite was also evaluated, which revealed its insignificant impact on the cell viability. These results suggest the nanocomposite of nickel-decorated manganese oxynitride on graphene nanosheets as a promising photocatalyst for the remediation of ASA-contaminated water.

Enhanced visible light-driven photocatalysis of iron-oxide/titania composite: Norfloxacin degradation mechanism and toxicity study.

A simulated visible light-mediated iron oxide-titania (IoT) nanocomposite was employed to degrade the antibiotic norfloxacin (NFN) photocatalytically. The photocatalyst were prepared using a sol-gel method with controlled titania loadings to iron oxide by altering the fabrications step. The nanocomposites were structurally characterized by field emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), field emission high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, Diffuse reflectance UV-visible spectra (DRS-UV) spectroscopy, cyclic voltammetry, and X-ray photoelectron spectroscopy (XPS). It was observed that 100 mg/L of iron oxide doped titania loading at 1:4 (IoT-4) achieved the maximum photocatalytic activity in a 75 mg/100 mL of NFN solution within 60 min of the reaction time under visible light irradiation. The NFN degradation mechanism affirmed using HPLC-MS/MS analysis and the results confirmed the complete NFN degradation without residual intermediates. Significant, sustained recyclability was obtained by completely removing the contaminant up to 5 cycles with 90% degradation ability till nine cycles. Bacterial- and phytotoxicity data ascertain that the photocatalyzed and contaminant-free water is safe for the environment. The outstanding photocatalytic performance in removing organic pollutants indicates the potential application of IoT nanocomposites in real-time environmental remediation.

Enhanced visible light-driven photocatalytic activity of reduced graphene oxide/cadmium sulfide composite: Methylparaben degradation mechanism and toxicity.

Reduced graphene oxide/cadmium sulfide (RGOCdS) nanocomposite synthesized through solvothermal process was used for methylparaben (MeP) degradation. The crystallinity of the nanocomposite was ascertained through X-ray diffraction. High resolution transmission electron microscope (HRTEM) results proved the absence of any free particle beyond the catalyst surface ensuring the composite nature of the prepared material. The enhancement in the activity on doping with RGO was substantiated by diffuse reflectance spectroscopy (DRS-UV). It is evident from the photocatalytic degradation experiments that RGOCdS is more efficient than pure CdS. Maximum MeP degradation (100%) was achieved after 90 min of irradiation with 750 mg/L RGOCdS dosage at an acidic pH of 3, for an initial MeP concentration of 30 mg/L. The degradation mechanism substantiated through HPLC-MS/MS analysis showed the complete degradation of MeP without any residual intermediaries. The catalyst could be sustained and reused for up to 9 cycles of usage. Phytotoxicity and mycotoxicity results evidently ascertain the environmental implications of the photocatalyst material.

Nanoscale Perovskite-Sensitized Solar Cell Revisited: Dye-Cell or Perovskite-Cell?

A general and straightforward way of preparing few-nanometer-sized well-separated MAPbIx Br3-x (MA=methylammonium) perovskite photosensitizers on the surface of an approximately 1 µm thick mesoporous TiO2 photoanode was suggested through a two-step sequential deposition of low-concentrated lead halides (0.10-0.30 m PbI2 or PbBr2 ) and methylammonium iodide/bromide (MAI/MABr). When those nanoscale MAPbIx Br3-x perovskites were incorporated as a photosensitizer in typical solid-state dye-sensitized solar cells (ss-DSSCs), it could be verified clearly by the capacitance analysis that nano-particulate MAPbI3 perovskites play the same role as that of a typical dye sensitizer (MK-2 molecule) although their size, composition, and structure are different.

Author Correction: Surface plasmon enhanced Organic color image sensor with Ag nanoparticles coated with silicon oxynitride.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Surface plasmon enhanced Organic color image sensor with Ag nanoparticles coated with silicon oxynitride.

As organic photodetectors with less than 1 µm pixel size are in demand, a new way of enhancing the sensitivity of the photodetectors is required to compensate for its degradation due to the reduction in pixel size. Here, we used Ag nanoparticles coated with SiOxNy as a light-absorbing layer to realize the scale-down of the pixel size without the loss of sensitivity. The surface plasmon resonance appeared at the interface between Ag nanoparticles and SiOxNy. The plasmon resonance endowed the organic photodetector with boosted photon absorption and external quantum efficiency. As the Ag nanoparticles with SiOxNy are easily deposited on ITO/SiO2, it can be adapted into various organic color image sensors. The plasmon-supported organic photodetector is a promising solution for realizing color image sensors with high resolution below 1 µm.

Orientation-specific switching of inelastic electron tunneling in an oxygen-pyridine complex adsorbed onto an Ag(110) surface.

Here, we report the development of a molecular rotary switch (a "stator-rotor" consisting of a single oxygen molecule as a stator and a single pyridine molecule as a rotor) on a silver surface. The pyridine molecule was bonded to the oxygen molecule and was found to rotate to enable "ON" or "OFF" vibrational conductance through the oxygen molecule. Four stable sites around the oxygen molecule were observed, and vibration conductance turned on and off depending on the site at which the pyridine molecule bonded. The spatially resolved mapping of the vibrational change revealed two locations of maximal vibration intensity, separated by ∼3 Å. These positions acted as two conducting channels. The two distinct vibrational energy levels were associated with the switching process. Adsorption-induced electron transfer between the silver layers and the molecules enhanced the local interactions between the molecules. The two vibration modes were excited by resonant tunneling despite substantial interactions between the molecules, which resulted in a decrease in tunneling conductance. An independent pathway exists for the vibrational excitation process by tunneling electrons and intermolecular interactions.

Unprecedented green-emissive boranyl-hydrazone supramolecular assemblies and their in vitro diagnostic applications.

This paper describes a novel symmetric N,N'-diethylsalicylaldehyde boranyl hydrazone (1) and its in situ-generated assemblies displaying opto-analytical capabilities for the diagnosis of nucleic acids under physiological conditions. The sensing capabilities of these unprecedented supramolecular assemblies were characterized using UV-Vis spectroscopy, fluorescence spectroscopy, 1D and 2D NMR spectroscopy, dynamic light scattering, and zeta potential measurements. Model compounds lacking boranyl units (2, 3) were prepared to correlate and evaluate the sensing mechanism. The rationally designed probe 1 displays unusual aggregation-induced emissive (AIE) properties, with an average particle size of 1096 nm exhibiting green emission upon excitation at 377 nm in pH-7.2 TRIZMA buffer. A selective switch on response toward organic PO43- accompanied through specific nano-aggregations patterns and sizes, thereby causing a significant red-shift through AIE. Exploiting such switch on in green channel behavior has allowed the monitoring of DNase I activities and polymerase chain reactions.

Directed Nanoscale Self-Assembly of Natural Photosystems on Nitrogen-Doped Carbon Nanotubes for Solar-Energy Harvesting.

Natural photosystems (PSs) have received much attention as a biological solar energy harvester because of their high quantum efficiency for energy transfer. However, the PSs hybridized with solid electrodes exhibit low light-harvesting efficiencies because of poor interface properties and random orientations of PSs, all of which interfere with efficient charge extraction and transfer. Herein, we report the linker-free, oriented self-assembly of natural PSs with nitrogen-doped carbon nanotubes (NCNTs) via electrostatic interaction. Protonated nitrogen-doped sites on the NCNTs facilitate spontaneous immobilization of the negatively charged stroma side of PSs, which provides a favorable orientation for electron transfer without electrically insulating polymer linkers. The resulting PS/NCNT hybrids exhibit a photocurrent density of 1.25 ± 0.08 µA cm-2, which is much higher than that of PS/CNT hybrids stabilized with polyethylenimine (0.60 ± 0.01 µA cm-2) and sodium dodecyl sulfate (0.14 ± 0.01 µA cm-2), respectively. This work emphasizes the importance of the linker-free assembly of PSs into well-oriented hybrid structures to construct an efficient light-harvesting electrode.

Direct observation of the conformational transitions of single pyridine molecules on a Ag(110) surface induced by long-range repulsive intermolecular interactions.

The transition between two conformations of pyridine molecules adsorbed on a Ag(110) surface at 13 K was investigated by performing single-molecule manipulation at a very low coverage and the track-imaging of pyridines for various surface coverages using a variable low-temperature scanning tunneling microscope. A single tilted conformer was converted to an upright conformer when another coadsorbed tilted pyridine molecule approached to within ∼2 nm. The conversion probability depends on the molecular separation. The tilted conformers that are prevalent at a very low coverage were converted to upright conformers with an increasing surface coverage. The minimum molecular separation before this transition is induced was determined to be 2.2 nm using molecular track-imaging and statistical analysis of the pyridine separation as a function of the molecular coverage. The conformation transition was attributed to substrate-mediated long-range repulsive interactions between the pyridine molecules, which are produced by charge redistribution that occurs upon pyridine adsorption on the silver surface.

Exciton Recombination, Energy-, and Charge Transfer in Single- and Multilayer Quantum-Dot Films on Silver Plasmonic Resonators.

We examine exciton recombination, energy-, and charge transfer in multilayer CdS/ZnS quantum dots (QDs) on silver plasmonic resonators using photoluminescence (PL) and excitation spectroscopy along with kinetic modeling and simulations. The exciton dynamics including all the processes are strongly affected by the separation distance between QDs and silver resonators, excitation wavelength, and QD film thickness. For a direct contact or very small distance, interfacial charge transfer and tunneling dominate over intrinsic radiative recombination and exciton energy transfer to surface plasmons (SPs), resulting in PL suppression. With increasing distance, however, tunneling diminishes dramatically, while long-range exciton-SP coupling takes place much faster (>6.5 ns) than intrinsic recombination (~200 ns) causing considerable PL enhancement. The exciton-SP coupling strength shows a strong dependence on excitation wavelengths, suggesting the state-specific dynamics of excitons and the down-conversion of surface plasmons involved. The overlayers as well as the bottom monolayer of QD multilayers exhibit significant PL enhancement mainly through long-range exciton-SP coupling. The overall emission behaviors from single- and multilayer QD films on silver resonators are described quantitatively by a photophysical kinetic model and simulations. The present experimental and simulation results provide important and useful design rules for QD-based light harvesting applications using the exciton-surface plasmon coupling.