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Abstract: Catalysts with various Ag loading (0.7–5.2wt%) in the powder form were prepared by the sol–gel process controlled in the reverse micellar environment. X-ray diffraction (XRD), nitrogen adsorption measurement, UV–vis and elemental analysis were employed for characterization of catalysts. Effect of various silver loadings on photocatalytic activity of TiO2 catalysts in N2O photocatalytic decomposition was studied. Photocatalytic decomposition of N2O was performed in annular batch reactor illuminated with 8W Hg lamp (254nm wavelength). Reaction kinetic corresponds to first-order reaction rate which is in agreement with plausible reaction mechanisms. The highest N2O conversion of 77% after 24h was reach over TiO2 modified by 3.4wt% Ag. The Ag metal clusters could provoke a decrease in the electron–hole recombination rate. [Copyright &y& Elsevier]

Abstract: The kaolinite/TiO2 composite was prepared using thermal hydrolysis of kaolinite/titanyl sulphate suspension and characterized by XRFS, XRPD, SEM and N2 physical adsorption. Its photocatalytic properties were evaluated by photocatalytic reduction of CO2 by water and compared with commercial TiO2 photocatalyst Degussa P25. Results showed that the yields of CO2 photocatalytic reduction products methane and methanol were higher over a kaolinite/TiO2 composite than over commercial TiO2 (Degussa P25) in spite of smaller proportion of TiO2 in the composite. Introducing of TiO2 nanoparticles into the kaolinite structure caused a decrease of anatase crystallite size. Kaolinite can also change acidobasic properties of catalyst surface, inhibit the recombination of electron–hole pairs and prevent the formation of TiO2 aggregates in suspension. These facts can contribute to the observed higher photocatalytic efficiency of kaolinite/TiO2 compared to the commercial TiO2 photocatalyst. [Copyright &y& Elsevier]

Abstract: Pure TiO2 and various silver-enriched TiO2 powders were prepared by the sol–gel process controlled in the reverse micellar environment. The catalysts were tested in CO2 photocatalytic reduction and characterized by X-ray diffraction (XRD), nitrogen adsorption measurement and UV–vis. Methane and methanol were the main reduction products. The yield of methane and methanol increases when modifying the TiO2 by silver incorporation is caused by two mechanisms: up to 5% of Ag in TiO2 the Ag impurity band inside the TiO2 bandgap decreases the absorption edge and increases so the electron–hole pair generation, above 5% of Ag in TiO2 Ag metallic clusters are formed in TiO2 crystals with Shottky barrier at the metal–semiconductor interface, which spatially separates electron and holes and increases their lifetime (decreases probability of their recombination). [Copyright &y& Elsevier]

Abstract: Pure TiO2 anatase particles with a crystallite diameters ranging from 4.5 to 29nm were prepared by precipitation and sol–gel method, characterized by X-ray diffraction (XRD), BET surface area measurement, UV–vis and scanning electron microscopy (SEM) and tested in CO2 photocatalytic reduction. Methane and methanol were the main reduction products. The optimum particle size corresponding to the highest yields of both products was 14nm. The observed optimum particle size is a result of competing effects of specific surface area, charge–carrier dynamics and light absorption efficiency. [Copyright &y& Elsevier]

Highlights: [•] ZnS nanoparticles deposited on montmorillonite forming ZnS-MMT nanocomposite. [•] Catalyst for photocatalytic decomposition of N2O. [•] Better catalytic performance in fluidized bed than fixed bed. [•] Presence of water vapor inhibited N2O decomposition by photocatalysis. [•] Presence of water vapor improved N2O photolysis. [ABSTRACT FROM AUTHOR]

Abstract: TiO2 and Ag-TiO2 (0.05, 0.25 and 1wt% of Ag) thin films were prepared by the sol–gel method. The prepared films were characterized using SEM-EDAX, XRD, Raman spectroscopy, atomic force microscopy and UV–Vis spectrometry. Photocatalytic decomposition of N2O was performed in an annular batch reactor illuminated with an 8W Hg lamp (254nm wavelength). The photoreactivity of Ag-TiO2 increases with the Ag amount to 0.25wt% Ag. Further increase of Ag loading to 1wt% Ag did not change N2O conversion. The Ag particles deposited on the TiO2 surface can act as electron–hole separation centers. The presence of water vapor and oxygen in the reaction mixture slightly improved N2O conversion. [Copyright &y& Elsevier]

Utilizing photocatalytic CO 2 reduction presents a promising avenue for combating climate change and curbing greenhouse gas emissions. However, maximizing its potential hinges on the development of materials that not only enhance efficiency but also ensure process stability. Here, we introduce Hiroshima University Silicate-7 (HUS-7) with immobilized Ti species as a standout contender. Our study demonstrates the remarkable photocatalytic activity of HUS-7 in CO 2 reduction, yielding substantially higher carbonaceous product yields compared to conventional titanium-based catalysts TS-1 and P25. Through thorough characterization, we elucidate that their boosted photocatalytic performance is attributed to the incorporation of isolated Ti species within the silica-based precursor, serving as potent photoinduced active sites. Moreover, our findings underscore the crucial role of the Ligand-to-Metal Charge Transfer (LMCT) process in facilitating the photoactivation of CO 2 molecules, shedding new light on key mechanisms underlying photocatalytic CO 2 reduction., (© 2024 The Authors. ChemSusChem published by Wiley-VCH GmbH.)

Background: Atherosclerosis is a major cause of ischemic stroke, and early detection of advanced atherosclerosis in the carotid artery is important for reducing morbidity and mortality. What is even more important is not only detection of atherosclerosis but early determination whether the patients are at high risk of an event with adverse effects as the size of the plaque does not necessarily reflect its potential to trigger such events., Aim: We studied whether plasma lipidomics profile can be used as a diagnostic tool for stratification of stable or unstable plaques without the need of removing the carotid plaque., Methods: This study used liquid chromatography high-resolution tandem mass spectrometry lipidomics to characterize lipid profiles in patients' plasma and found that patients with significant and complicated (vulnerable) atherosclerotic plaque had distinct lipid profiles compared to those with insignificant plaques., Results: The lipid classes that were most predictive of vulnerable plaque were lysophosphoethanolamines, fatty acyl esters of hydroxy fatty acids, free fatty acids, plasmalogens, and triacylglycerols. Most of these compounds were found decreased in plasma of patients with unstable plaques which enabled sufficient performance of a statistical model used for patient stratification., Conclusions: Plasma lipidomes measured by liquid chromatography-mass spectrometry show differences in patients with stable and unstable carotid plaques, therefore these compounds could potentially be used as biomarkers for unstable plaque in future clinical diagnosis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Herein, the synthesis, characterization, and reduction properties of 2D TiO 2 aerogel powder decorated with BiVO 4 (TiO 2 /BiVO 4 ) were investigated for versatile applications. First, 2D TiO 2 was prepared via lyophilization and subsequently modified with BiVO 4 using a wet impregnation method. The morphology, structure, composition, and optical properties were evaluated using transmission electron microscopy (TEM), X-ray diffractometry (XRD), laser-induced breakdown spectroscopy (LIBS), and diffuse reflectance spectroscopy (DRS), respectively. Significantly enhanced photocurrent densities (by 3-15 times) were obtained for TiO 2 /BiVO 4 compared to those of pure TiO 2 and BiVO 4 . The reduction of toxic Cr(VI) to Cr(III) was assessed, including the effect of pH on overall photocatalytic efficiency. Under acidic conditions (pH ∼ 2), Cr(VI) reduction efficiency reached 100% within 2 h. For photocatalytic CO 2 reduction, the highest yields of CH 4 and CO were obtained using TiO 2 /BiVO 4 . A higher efficiency for both applications was achieved because of the better separation of the electron-hole pairs in TiO 2 /BiVO 4 . The excellent stability of TiO 2 /BiVO 4 over repeated runs highlights its potential for use in versatile environmental applications. The efficiency of TiO 2 /BiVO 4 is due to the interplay of the structure, morphology, composition, and photoelectrochemical properties that favour the material for the presented herein photocatalytic applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The use of an irradiation source with a homogeneous distribution of irradiation in the volume of the reaction mixture belongs to the essential aspects of heterogeneous photocatalysis. First, the efficacy of six lamps with various radiation intensity and distribution characteristics is contrasted. The topic of discussion is the photocatalytic hydrogen production from a methanol-water solution in the presence of a NiO-TiO 2 photocatalyst. The second section is focused on the potential of a micro-photoreactor system-the batch reactor with a micro-reactor with a circulating reaction mixture, in which the photocatalytic reaction takes place using TiO 2 immobilized on borosilicate glass. Continuous photocatalytic hydrogen generation from a methanol-water solution is possible in a micro-photoreactor. This system produced 333.7 ± 21.1 µmol H 2 (252.8 ± 16.0 mmol.m -2 , the hydrogen formation per thin film area) in a reproducible manner during 168 h., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Meinhardová, Dubnová, Drobná, Matějová, Kočí and Čapek.)

The feasibility of using advanced oxidation processes (AOPs) for abatement of ammonia from livestock buildings was examined in a series of pilot plant experiments. In this study, all the experiments were conducted in a two-step unit containing a dry photolytic reactor (UV 185 /UV 254 /O 3 ) and a photochemical scrubber (UV 254 /H 2 O 2 ). The unit efficiency was tested for two initial ammonia concentrations (20 and 35 ppmv) and three different air flows (150, 300 and 450 m 3 ·h -1 ). While the first step removes mainly organic pollutants that are often present together with ammonia in the air and ammonia only partially, the second step removes around 90% of ammonia emissions even at the highest flow rate of 450 m 3 ·h -1 . Absorbed ammonia in the aqueous phase can be effectively removed without adjusting the pH (i.e. without the addition of other additives) using UV and ozone. Complete removal of ammonia was achieved after 15 h of irradiation. In order to assess the price efficiency of the suggested technology and to be able to compare it with other methods the figures-of-merit were determined. The price needed for lowering ammonia emission by one order of magnitude is 0.002 € per cubic meter of treated air at the highest flow rate of 450 m 3 ·h -1 and for initial ammonia concentrations of 20 ppmv. These findings demonstrate that AOPs are a promising method for ammonia abatement from livestock buildings which are rarely using any waste air treatment method., (© 2023. The Author(s).)

Background: Predicting stroke risk in patients with carotid artery stenosis (CS) remains challenging. Circulating biomarkers seem to provide improvements with respect to risk stratification. Methods: Study patients who underwent carotid endarterectomy were categorized into four groups according to symptomatology and compared as follows: symptomatic with asymptomatic patients; and asymptomatic patients including amaurosis fugax (AF) (asymptomatic + AF group) with patients with a transient ischemic attack (TIA) or brain stroke (BS) (hemispheric brain stroke group). Carotid specimens were histologically analyzed and classified based on the American Heart Classification (AHA) standard. As a marker of OS, the plasma levels of malondialdehyde (MDA) were measured. Comparisons of MDA plasma levels between groups were analyzed. Results : In total, 35 patients were included in the study. There were 22 (63%) patients in the asymptomatic group and 13 (37%) in the symptomatic group. Atheromatous plaque ( p = 0.03) and old hemorrhage ( p = 0.05), fibrous plaque ( p = 0.04), myxoid changes ( p = 0.02), plaques without hemorrhage ( p = 0.04), significant neovascularization ( p = 0.04) and AHA classification ( p = 0.006) had significant correlations with clinical presentation. There were 26 (74%) patients in the asymptomatic group and 9 (26%) in the hemispheric brain stroke group. Atheromatous plaque ( p = 0.02), old hemorrhage ( p = 0.05) and plaques without neovascularization ( p = 0.02), fibrous plaque ( p = 0.03), plaques without hemorrhage ( p = 0.02) and AHA classification ( p = 0.01) had significant correlations with clinical presentation. There was no significant difference between symptomatic and asymptomatic groups with respect to MDA plasma levels ( p = 0.232). A significant difference was observed when MDA plasma levels were compared to asymptomatic + AF and the hemispheric stroke group ( p = 0.002). Conclusions : MDA plasma level correlates with the risk of hemispheric stroke (TIA or BS) and is a reliable marker of plaque vulnerability in carotid artery stenosis.

An active pharmaceutical ingredient (API) is any substance in a pharmaceutical product that is biologically active. That means the specific molecular entity is capable of achieving a defined biological effect on the target. These ingredients need to meet very strict limits; chemical and optical purity are considered to be the most important ones. A continuous-flow synthetic methodology which utilizes a continuously flowing stream of reactive fluids can be easily combined with photochemistry, which works with the chemical effects of light. These methods can be useful tools to meet these strict limits. Both of these methods are unique and powerful tools for the preparation of natural products or active pharmaceutical ingredients and their precursors with high structural complexity under mild conditions. This review shows some main directions in the field of active pharmaceutical ingredients' preparation using continuous-flow chemistry and photochemistry with numerous examples of industry and laboratory-scale applications.

Introduction: Pancreatic cancer is a severe oncological disease with an ever-increasing incidence and a high rate of morbidity and mortality. Therapeutic options are limited and the five-year overall survival rate is 7–20%, depending on the possibility of surgical resection and the earliness of detection. Most patients with this diagnosis die due to the resistance of tumour cells and their microenvironment to the used treatment regimes. Methods: In our study, we focused on the implementation of two in vivo models, which are the cell-line derived xenograft (CDX) and the patient-derived xenograft (PDX). These two models differ significantly from each other methodologically, technically, financially, but also in their achieved results. Results: In a pilot study, we managed to successfully implement the CDX model with a very aggressive and resistant PaCa-44 line of pancreatic cancer in a total of 30 NU/NU strain mice. Furthermore, we created three PDX models with various subtypes of pancreatic cancer from patients operated at the University Hospital Kralovske Vinohrady, Department of General Surgery. These tumours were re-transplanted into subsequent generations of 23 individuals of NOD/SCID strain and 47 NU/NU strain mice. The established CDX and PDX models are then used to compare conventional and experimental chemotherapy regimens. Conclusion: The next steps will be to evaluate the effects of treatment regimens by using imaging and molecular genetic methods and to optimise the entire process for further use in precise personalised medicine for patients with pancreatic cancer. The upcoming goal is to create a library of PDX models of the most common pancreatic ductal adenocarcinoma and other rare subtypes of pancreatic cancer.

Graphitic carbon nitride (C 3 N 4 ) was synthesised from melamine at 550 °C for 4 h in the argon atmosphere and then was reheated for 1-3 h at 500 °C in argon. Two band gaps of 2.04 eV and 2.47 eV were observed in all the synthetized materials. Based on the results of elemental and photoluminescence analyses, the lower band gap was found to be caused by the formation of vacancies. Specific surface areas of the synthetized materials were 15-18 m 2 g -1 indicating that no thermal exfoliation occurred. The photocatalytic activity of these materials was tested for hydrogen generation. The best photocatalyst showed 3 times higher performance (1547 μmol/g) than bulk C 3 N 4 synthetized in the air (547 μmol/g). This higher activity was explained by the presence of carbon (V C ) and nitrogen (V N ) vacancies grouped in their big complexes 2V C  + 2V N (observed by positron annihilation spectroscopy). The effect of an inert gas on the synthesis of C 3 N 4 was demonstrated using Graham´s law of ammonia diffusion. This study showed that the synthesis of C 3 N 4 from nitrogen-rich precursors in the argon atmosphere led to the formation of vacancy complexes beneficial for hydrogen generation, which was not referred so far., (© 2022. The Author(s).)

The photocatalytic reduction of carbon dioxide to renewable fuel or other valuable chemicals using solar energy is attracting the interest of researchers because of its great potential to offer a clean fuel alternative and solve global warming problems. Unfortunately, the efficiency of CO 2 photocatalytic reduction remains not very high due to the fast recombination of photogenerated electron-hole and small light utilization. Consequently, tremendous efforts have been made to solve these problems, and one possible solution is the use of heterojunction photocatalysts. This review begins with the fundamental aspects of CO 2 photocatalytic reduction and the fundamental principles of various heterojunction photocatalysts. In the following part, we discuss using TiO 2 heterojunction photocatalysts with other semiconductors, such as C 3 N 4 , CeO 2 , CuO, CdS, MoS 2 , GaP, CaTiO 3 and FeTiO 3 . Finally, a concise summary and presentation of perspectives in the field of heterojunction photocatalysts are provided. The review covers references in the years 2011-2021.

Pt, Ru, and Ir were introduced onto the surface of graphitic carbon nitride (g-C 3 N 4 ) using the wet impregnation method. A reduction of these photocatalysts with hydrogen causes several changes, such as a significant increase in the specific surface area, a C/N atomic ratio, a number of defects in the crystalline structure of g-C 3 N 4 , and the contribution of nitrogen bound to the amino and imino groups. According to the X-ray photoelectron spectroscopy results, a transition layer is formed at the g-C 3 N 4 /metal nanoparticle interphase, which contains metal at a positive degree of oxidation bonded to nitrogen. These structural changes significantly enhanced the photocatalytic activity in the production of hydrogen through the water-splitting reaction. The activity of the platinum photocatalyst was 24 times greater than that of pristine g-C 3 N 4 . Moreover, the enhanced activity was attributed to significantly better separation of photogenerated electron-hole pairs on metal nanoparticles and structural distortions of g-C 3 N 4 .

Sepsis and septic shock remain leading causes of morbidity and mortality for patients in the intensive care unit. During the early phase, immune cells produce various cytokines leading to prompt activation of the immune system. Polymorphonuclear leukocytes (PMNs) respond to different signals producing inflammatory factors and executing their antimicrobial mechanisms, resulting in the engulfment and elimination of invading pathogens. However, excessive activation caused by various inflammatory signals produced during sepsis progression can lead to the alteration of PMN signaling and subsequent defects in their functionality. Here, we analyzed samples from 34 patients in septic shock, focusing on PMNs gene expression and proteome changes associated with septic shock. We revealed that, compared to those patients who survived longer than five days, PMNs from patients who had fulminant sepsis were characterized by a dysfunctional hyper-activation, show altered metabolism, and recent exit from the cell cycle and signs of cellular lifespan. We believe that this multi-omics approach, although limited, pinpoints the alterations in PMNs' functionality, which may be rescued by targeted treatments., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2021 Hortová-Kohoutková, De Zuani, Lázničková, Bendíčková, Mrkva, Andrejčinová, Mýtniková, Polanský, Kočí, Tomášková, Šrámek, Helán and Frič.)

The removal of indoor and outdoor air pollutants is crucial to prevent environmental and health issues. Photocatalytic building materials are an energy-sustainable technology that can completely oxidize pollutants, improving in situ the air quality of contaminated sites. In this work, different photoactive TiO 2 catalysts (anatase or modified anatase) and amounts were used to formulate photocatalytic paints in replacement of the normally used TiO 2 (rutile) pigment. These paints were tested in two different experimental systems simulating indoor and outdoor environments. In one, indoor illumination conditions were used in the photoreactor for the oxidation of acetaldehyde achieving conversions between 37 and 55%. The other sets of experiments were performed under simulated outdoor radiation for the degradation of nitric oxide, resulting in conversions between 13 and 35%. This wide range of conversions made it difficult to directly compare the paints. Thus, absorption, photonic, and quantum efficiencies were calculated to account for the paints photocatalytic performance. It was found that the formulations containing carbon-doped TiO 2 presented the best efficiencies. The paint with the maximum amount of this photocatalyst showed the highest absorption and photonic efficiencies. On the other hand, the paint with the lowest amount of carbon-doped TiO 2 presented the highest value of quantum efficiency, thus becoming the optimal formulation in terms of energy use., (Copyright © 2020 Salvadores, Reli, Alfano, Kočí and Ballari.)

Graphitic carbon nitride (g-C 3 N 4 ) was obtained by thermal polymerization of dicyandiamide, thiourea or melamine at high temperatures (550 and 600 °C), using different heating rates (2 or 10 °C min -1 ) and synthesis times (0 or 4 h). The effects of the synthesis conditions and type of the precursor on the efficiency of g-C 3 N 4 were studied. The most efficient was the synthesis from dicyandiamide, 53%, while the efficiency in the process of synthesis from melamine and thiourea were much smaller, 26% and 11%, respectively. On the basis of the results provided by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared spectroscopy (FTIR), ultraviolet-visible spectroscopy (UV-vis), thermogravimetric analysis (TGA), elemental analysis (EA), the best precursor and the optimum conditions of synthesis of g-C 3 N 4 were identified to get the product of the most stable structure, the highest degree of ordering and condensation of structure and finally the highest photocatalytic activity. It was found that as the proton concentration decreased and the degree of condensation increased, the hydrogen yields during the photocatalytic decomposition of water-methanol solution were significantly enhanced. The generation of hydrogen was 1200 µmol g -1 and the selectivity towards hydrogen of more than 98%.