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Carmofur, a 5-fluorouracil (5-FU) derivative, was initially developed as an antineoplastic agent to treat colorectal cancer. Through drug repurposing efforts, it has been identified as a potent covalent inhibitor of the main protease of SARS-CoV-2 ([M.sup.pro]), making it a promising therapeutic agent against COVID-19. However, previous synthetic procedures suffer from low yields or long reaction times. In this study, benchtop [.sup.19]F nuclear magnetic resonance (NMR) spectroscopy enables the realtime quantitative monitoring and characterization of the synthesis of carmofur by providing kinetic insight. Furthermore, its proton lock capabilities no longer require the use of deuterated solvents and have enabled convenient and rapidly scalable synthesis of our compound. Here, we present the application of benchtop [.sup.19]F NMR as an efficient method for optimizing the synthesis of carmofur and its future application in the synthesis of related 5-FU analogs. Key words: carmofur, benchtop nuclear magnetic resonance spectroscopy, [.sup.19]F NMR, reaction monitoring, reaction optimization, Introduction Fluorinated bioactive small molecules have a remarkable role in modern medicinal chemistry, as the incorporation of fluorine into drug candidates enhances their bioavailability, metabolic stability, and binding affinity to [...]

Carmofur, a 5-fluorouracil (5-FU) derivative, was initially developed as an antineoplastic agent to treat colorectal cancer. Through drug repurposing efforts, it has been identified as a potent covalent inhibitor of the main protease of SARS-CoV-2 (Mpro), making it a promising therapeutic agent against COVID-19. However, previous synthetic procedures suffer from low yields or long reaction times. In this study, benchtop 19F nuclear magnetic resonance (NMR) spectroscopy enables the real-time quantitative monitoring and characterization of the synthesis of carmofur by providing kinetic insight. Furthermore, its proton lock capabilities no longer require the use of deuterated solvents and have enabled convenient and rapidly scalable synthesis of our compound. Here, we present the application of benchtop 19F NMR as an efficient method for optimizing the synthesis of carmofur and its future application in the synthesis of related 5-FU analogs. [ABSTRACT FROM AUTHOR]

Using pulsed laser deposition, Zn0.92− x Co0.08 Cu x O (0 ≤ x ≤ 0.107) thin films were prepared on Si (100) substrates. The effect of Cu codoping on the electrical and ferromagnetic properties of Co: ZnO thin films is investigated by annealing the thin films in oxygen and hydrogen atmospheres, respectively. X-ray diffraction, X-ray absorption spectroscopy, transmission electron microscope, and X-ray photoelectron spectroscopy analyses indicated that the Co and Cu ions are incorporated into ZnO lattice. Hall measurements revealed that the electron concentration in the Zn0.92− x Co0.08 Cu x O thin film decreases with the increase of the Cu content. The as-deposited Zn0.92− x Co0.08 Cu x O thin film displayed intrinsic room temperature ferromagnetism. After annealing in hydrogen, the saturation magnetization of the films increase progressively with Cu content until a maximum value of 26.5 emu/cm3 (0.86μB/ Co) at 3.1 at.% Cu is obtained. Then the saturation magnetization drops off as the Cu content further increases. The change of magnetization of the films is attributed to the Cu codoping and variation of oxygen vacancies in the films. [ABSTRACT FROM AUTHOR]

Ni2P has been decorated on CdS nanowires or nanorods for efficient photocatalytic H2 production, whereas the specific surface area remains limited because of the large size. Here, the composites of Cd0.5Zn0.5S quantum dots (QDs) on thin Ni2P porous nanosheets with high specific surface area were constructed for noble metal-free photocatalytic H2 generation. The porous Ni2P nanosheets, which were formed by the interconnection of 15–30 nm-sized Ni2P nanoparticles, allowed the uniform loading of 7 nm-sized Cd0.5Zn0.5S QDs and the loading density being controllable. By tuning the content of Ni2P, H2 generation rates of 43.3 μM h− 1 (1 mg photocatalyst) and 700 μM h− 1 (100 mg photocatalyst) and a solar to hydrogen efficiency of 1.5% were achieved for the Ni2P-Cd0.5Zn0.5S composites. The effect of Ni2P content on the light absorption, photoluminescence, and electrochemical property of the composite was systematically studied. Together with the band structure calculation based on density functional theory, the promotion of Ni2P in charge transfer and HER activity together with the shading effect on light absorption were revealed. Such a strategy can be applied to other photocatalysts toward efficient solar hydrogen generation. [ABSTRACT FROM AUTHOR]

Abstract: Highly ordered titanium oxide nanotube arrays are synthesized by a two-step anodic oxidation of pure titanium foil at constant voltage. It is found that the length of nanotube arrays firstly increased rapidly with the anodization time, and then the growth rate gradually slowed down with further increasing the anodization time. The mechanism of anodization time-dependent tube length growth is discussed. Large area free-standing TiO2 nanotube (TNT) arrays are detached from the underlying Ti foil and transferred onto the fluorine-doped tin oxide (FTO) conductive glass substrates to serve as the photoanodes of the dye-sensitized solar cells (DSSCs). The photoelectric performance of the DSSCs assembled by TNT/FTO films is strongly related to the tube length of titania and the surface treatment. For the photoanodes without any surface modification, the highest overall photovoltaic conversion efficiency (PCE) that can be achieved is 4.12% in the DSSC assembled with 33-μm-thick TNT arrays, while the overall PCE of DSSC based on the 33-μm-thick TNT arrays increases to 9.02% in response to the treatment with TiCl4. [Copyright &y& Elsevier]

Benchtop nuclear magnetic resonance (NMR) spectroscopy has enabled the monitoring and optimization of chemical transformations while simultaneously providing kinetic, mechanistic, and structural insight into reaction pathways with quantitative precision. Moreover, benchtop NMR proton lock capabilities further allow for rapid and convenient monitoring of various organic reactions in real time, as the use of deuterated solvents is not required. The complementary role of 19 F NMR-based kinetic monitoring in the fluorination of bioactive compounds has many benefits in the drug discovery process since fluorinated motifs additionally improve drug pharmacology. In this study, 19 F NMR spectroscopy was utilized to monitor the synthesis of novel trifluorinated analogs of monastrol, a small molecule dihydropyrimidinone kinesin-Eg5 inhibitor, and to probe the mechanism of the Biginelli cyclocondensation, a multicomponent reaction used to synthesize dihydropyrimidinone and tetrahydropyrimidinones through a Bronsted- or Lewis-acid catalyzed cyclocondensation between ethyl acetoacetate, thiourea, and an aryl aldehyde. In the present study, a trifluorinated ketoester serves a dual purpose as being the source of the trifluoromethyl group in our fluorinated dihydropyrimidinones and as a spectroscopic handle for real-time reaction monitoring and tracking of reactive intermediates by 19 F NMR. Further, upon extending this workflow to a diverse array of 3- and 4-substituted aryl aldehydes, we were able to derive Hammett linear free energy relationships (LFER) to determine stereoelectronic effects of para- and meta- substituted aryl aldehydes to corresponding reaction rates and mechanistic routes. In addition, we used density functional theory (DFT) calculations to corroborate our experimental results through the thermodynamic values of key intermediates in each mechanism. Finally, these studies culminate in the synthesis of a novel trifluorinated analog of monastrol and its subsequent biological evaluation in vitro. More broadly, we show an application of benchtop 19 F NMR spectroscopy as an analytical tool in the real-time investigation of a mechanistically and chemically complex multicomponent reaction mixture., Competing Interests: The authors declare no competing financial interest., (© 2023 The Authors. Published by American Chemical Society.)

The association between exposure to ambient fine particulate matter with an aerodynamic diameter of ≤ 2.5 μm (PM 2.5 ) and short- and medium-term lung function recovery (LFR) in patients undergoing lobectomy remains uncertain. This study investigated the associations between PM 2.5 concentrations and LFR in adult patients ( n = 526) who underwent video-assisted thoracoscopic (VATS) lobectomy in Guangzhou, China between January 2018 and June 2021. All patients underwent at least two spirometry tests. Environmental PM 2.5 concentrations in the same period were collected from the nearest monitoring station. A multiple linear regression (MLR) model was employed to investigate the associations between changes in PM 2.5 concentrations and LFR in patients who underwent lobectomy after adjusting for potential confounders. We assessed short- and medium-term LFR in patients who underwent lobectomy. The three- and 6-month average PM 2.5 concentrations in each patient's residential area were divided into regional mild pollution (PM 2.5 <25 μg/m 3 ), moderate pollution (25 μg/m 3 ≤ PM 2.5 <35 μg/m 3 ), and severe pollution (35 μg/m 3 ≤ PM 2.5 ) periods. The MLR model confirmed that PM 2.5 was an independent risk factor affecting short-term forced lung capacity (FVC), forced expiratory volume in 1 s (FEV1), and maximum expiratory flow at 50% vital capacity (MEF 50 ) recovery (adjusted P = 0.041, 0.014, 0.016, respectively). The MLR model confirmed that PM 2.5 was an independent risk factor affecting medium-term MEF 50 recovery (adjusted P = 0.046). Compared with the moderate and severe pollution periods, the short- and medium-term LFR (FVC, FEV1, MEF 50 ) of patients in the mild pollution period were faster and better ( P < 0.001, P < 0.001, P < 0.001, P = 0.048, P = 0.010, P = 0.013, respectively). Thus, exposure to high PM 2.5 levels was associated with significantly reduced speed and degree of short- and medium-term LFR in patients who underwent lobectomy., 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 © 2022 Liu, Xiao, Huang, Hu, Wang, Chen, Huang and Yang.)

Cd x Zn 1- x S nanocrystals with sizes ranging from 3-11 nm were synthesized by a simple organic solution method. The nanocrystals possess a cubic zinc-blende structure and the bandgap blue-shifts from 2.1 eV to 3.4 eV by increasing the composition of Zn ions in the solid solutions. After a facile ligand exchange process, the photocatalytic activity for H 2 production of the Cd x Zn 1- x S nanocrystals was investigated under visible-light irradiation ( λ ≥ 420 nm) with Na 2 SO 3 /Na 2 S as the electron donor. It was found that the Cd 0.8 Zn 0.2 S had the highest photoactivity with H 2 evolution rate of 6.32 mmol g -1 h -1 . By in situ adding Pt precursors into the reaction solution, inhomogenous Pt-Cd x Zn 1- x S nanoheterostructures were formed, which accounted for a 30% enhancement for the H 2 evolution rate comparing with that of pure Cd 0.8 Zn 0.2 S nanocrystals. This work highlights the use of facile organic synthesis in combination with suitable surface modification to enhance the activity of the photocatalysts., Competing Interests: There are no conflicts to declare., (This journal is © The Royal Society of Chemistry.)

Ni 2 P has been decorated on CdS nanowires or nanorods for efficient photocatalytic H 2 production, whereas the specific surface area remains limited because of the large size. Here, the composites of Cd 0.5 Zn 0.5 S quantum dots (QDs) on thin Ni 2 P porous nanosheets with high specific surface area were constructed for noble metal-free photocatalytic H 2 generation. The porous Ni 2 P nanosheets, which were formed by the interconnection of 15-30 nm-sized Ni 2 P nanoparticles, allowed the uniform loading of 7 nm-sized Cd 0.5 Zn 0.5 S QDs and the loading density being controllable. By tuning the content of Ni 2 P, H 2 generation rates of 43.3 μM h - 1 (1 mg photocatalyst) and 700 μM h - 1 (100 mg photocatalyst) and a solar to hydrogen efficiency of 1.5% were achieved for the Ni 2 P-Cd 0.5 Zn 0.5 S composites. The effect of Ni 2 P content on the light absorption, photoluminescence, and electrochemical property of the composite was systematically studied. Together with the band structure calculation based on density functional theory, the promotion of Ni 2 P in charge transfer and HER activity together with the shading effect on light absorption were revealed. Such a strategy can be applied to other photocatalysts toward efficient solar hydrogen generation.