In situ growth of BiOBr on copper foam conductive substrate with enhanced photocatalytic performance.

Photocatalysis technology based on solar-powered semiconductors is widely recognized as a promising approach for achieving eco-friendly, secure, and sustainable degradation of organic contaminants. Nevertheless, conventional photocatalysts exhibit drawbacks such as a wide bandgap, and rapid recombination of photoinduced electron/hole pairs, in addition to complicated separation and recovery procedures. In this research, we cultivated BiOBr in situ on the surface of copper foam to fabricate a functional photocatalyst (denoted as BiOBr/Cu foam), which was subsequently employed for the photodegradation of Methylene Blue. Based on photodegradation experiments, the 0.3 BiOBr/Cu foam demonstrates superior photocatalytic efficacy compared to other photocatalysts under solar light irradiation. Furthermore, its ease of separation from the solution enhances its potential for reuse. The analysis of charge transfer revealed that the copper foam functions as an effective electron scavenger within the BiOBr/Cu foam, thereby facilitating charge separation and the generation of photo-induced holes. This phenomenon contributes to a significantly enhanced production of hydroxyl radicals. This study provides a valuable perspective on the design and synthesis of photocatalysts with heightened practicality, employing a conductive substrate.

Patient With Takayasu Arteritis Treated with the Ozaki Procedure and Ascending Aorta Replacement.

Due to the specific pathogenesis of Takayasu arteritis, complicated with aortic valve disease, surgical treatment always has been a difficult problem. We report a 26-year-old female patient with Takayasu arteritis who was treated with the Ozaki procedure for aortic valve disease and replacement of the ascending aorta with a straight synthetic graft. The surgery achieved satisfactory early results.

Hydrochar coupled with iodide for efficient photodegradation of perfluorooctanoic acid and perfluorooctane sulfonic acid under ultraviolet light.

Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonic acid (PFOS) are typical emerging persistent organic pollutants that are raising concerns regarding their environmental persistence. The photodegradation of these chemicals in water can be promoted by generating hydrated electrons (eaq-). The present work demonstrates a highly efficient process combining ultraviolet (UV) radiation, hydrochar (H-BC) and KI that is capable of decomposing PFOA and PFOS. After 60 min of photolysis using this technique, 99.5 % and 94.1 % of the initial amounts of PFOA and PFOS in aqueous solution were degraded, respectively, with corresponding defluorination percentages of 87.8 % and 71.7 %, respectively. These degradation values were higher than the sum of those obtained using UV radiation with only H-BC or KI, implying a synergistic effect from the combination of H-BC and KI. This effect can be attributed to the unique structure and numerous oxygen-containing functional groups of the H-BC. This material was able to absorb PFOA and PFOS, reduce iodide oxidation products back to I-, act as an electron shuttle and shorten the diffusion distance to the target substrate. These factors all increased the probability of reactions between the contaminants and eaq-. Analyses by liquid chromatography/electrospray ionization/tandem mass spectrometry showed that short-chain perfluoroalkyl carboxylic acids with less than seven carbons were the primary degradation intermediates, suggesting that the photodegradation proceeded stepwise. These results confirmed the cooperative effect of the H-BC and iodide, leading to effective eaq- generation. This work is expected to facilitate the development of new strategies for the treatment of water systems contaminated with PFOA and PFOS.

Mitral annuloplasty with the interatrial groove-left atrial dome approach in a patient with Marfan syndrome.

BACKGROUND: The choice of mitral valve surgical approach has always been a difficult problem in patients with small left atrium. CASE PRESENTATION: We report a case of a patient with Marfan syndrome who underwent the David operation and mitral annuloplasty. The patient had a small left atrium, so we severed the superior vena cava and opened the interatrial groove and left atrial dome. This method allows for excellent exposure of the mitral valve and subvalvular apparatus, enabling a successful operation. CONCLUSION: The interatrial groove-left atrial dome approach provides an option for patients with a small left atrium undergoing mitral valve surgery.

Unexpected Persistent Production of Reactive Oxygen Species during the Degradation of Black Phosphorous in the Darkness.

Few-layer black phosphorus (FLBP) is easily degraded under ambient conditions which is problem that hinders the application of FLBP, but its degradation mechanism is not yet well understood. In this work, we surprisingly found that persistent generation of reactive oxygen species (ROS) was involved in FLBP degradation even in the dark. The ROS generation patterns and mechanism were revealed by chemiluminescence (CL) and density functional theory (DFT). Meanwhile, rhodamine B (RhB) and methyl orange (MO) can also be removed by FLBP under dark conditions, which further shows the ROS generation during FLBP self-degradation. This work provides new insights into the FLBP self-degradation mechanism and opens opportunities to practically implement FLBP for green catalytic application.

Dynamic control of pentachlorophenol photodegradation process using P25/PDA/BiOBr through regulation of photo-induced active substances and chemiluminescence.

Photodegradation is a new approach for the removal of pentachlorophenol (PCP). Photooxidation degradation (using hydroxyl radicals) exhibits better performance to remove PCP than photoreduction degradation, but the former will lead to an increase in the production of toxic by-products such as tetrachloro-1,4-benzoquinone (TCBQ). Thus, a new strategy is required to enhance PCP photodegradation and simultaneously inhibit toxic intermediates production. Herein, TiO2 (P25)/polydopamine (PDA)/BiOBr was synthesized and used to photodegrade PCP. Based on the relative position of the CB and VB of P25 and BiOBr, and PDA as an electron transfer mediator, a high number of holes, electrons, and superoxide anions were produced instead of hydroxyl radicals. The photocatalytic activity of P25/PDA/BiOBr exhibited the best performance among as-prepared samples, reaching a k(pcp) value of 0.4 min-1 (20 µM PCP) under UV light irradiation within 10 min. According to chemiluminescence and acute toxicity assays, relative to P25, the toxic intermediates of TCBQ and trichlorohydroxy-1,4-benzoquinone (OH-TrCBQ) generation was greatly reduced over P25/PDA/BiOBr, with a lack of toxic product generation during PCP photodegradation process. These findings provide an alternative strategy to achieve greener and more efficient organic pollutant photodegradation.

Exploring the origin of efficient adsorption of poly- and perfluoroalkyl substances in household point-of-use water purifiers: Deep insights from a joint experimental and computational study.

Poly- and perfluoroalkyl substances (PFAS) are harmful chemicals to humans and widely detected in water bodies including tap water. PFAS cannot be efficiently removed from water through conventional treatment processes used in full-scale drinking water treatment plants, posing a latent risk to human health via drinking tap water. Here in-field investigations show that the household point-of-use (POU) water purifiers constituted with coconut shell activated carbon can achieve 21%-99% removal for 14 legacy and emerging PFAS in tap water based on the ratio of influent and effluent. Extensive characterizations combine with chemical analyses demonstrate that physical adsorption based on Van der Waals force can remove 23 PFAS from tap water, wherein the hydrophobicity of PFAS is the crucial factor. Density functional theory calculations together with the quantitative structure-activity relationship model confirm that both topological structures as well as hydrophobicity of PFAS and electrostatic interactions between the strong electronegative F atoms and the adsorbent surface are the most critical factors controlling the PFAS adsorption to activated carbon. Overall, our results offer insights into the molecular mechanisms that enable the adsorption of PFAS in POU filters.

Efficient photodegradation of PFOA using spherical BiOBr modified TiO2 via hole-remained oxidation mechanism.

Photo-induced holes (h+) oxidation is an efficient approach for perfluorooctanoic acid (PFOA; C7F15COOH) removal. To maintain a high amount of h+ on the surface of photocatalysts participating in the PFOA photodegradation could be a critical issue. Herein, a highly efficient spherical BiOBr-modified nano-TiO2 (P25) was synthesised and used for PFOA photodegradation through direct oxidation with h+. A high number of h+ could be generated and remain on the surface of P25/BiOBr due to the appropriate position of the conduction band (CB) and valence band (VB) levels between P25 and BiOBr. Meanwhile, PFOA molecules were coordinated to the P25/BiOBr's surface via unidentate binding, being directly activated and oxidised by h+, resulting in a decomposition yield of 99.5% (100 mg/L) under simulated solar light irradiation within 100 min, at the initial pH condition (3.5). A stepwise photodegradation pathway was proposed due to the significant intermediates detected as the short-chain perfluorinated carboxylic acids (C2-C7). Reactive oxygen species (ROS) generation, scavenging and trapping analysis indicated that the direct oxidation on h+ followed PFOA degradation. In a real aqueous environment of Tangxun lake (adjusted pH 3.5), stable common anions and natural organic matter (NOM) would restrain the PFOA photodegradation. However, adding 10 mg/L of NO3- or HA could reduce the inhibition effect of PFOA photodegradation. These findings gave an alternative strategy to drive an h+ directly oxidation to treat PFOA contaminated water bodies.

Surgical radiofrequency ablation of atrial flutter: which operation should we choose?

The treatment of atrial flutter (AFL) in patients without structural heart disease (SHD) by transcatheter radiofrequency ablation of the cavotricuspid isthmus (CTI) and bilateral pulmonary veins has achieved good results. We report three cases of typical AFL treated by surgical radiofrequency ablation. One patient, without SHD, successfully underwent CTI ablation and cardioversion. The other two patients, with SHD, underwent CTI ablation, partial right atrial ablation and pulmonary vein isolation, but a normal sinus rhythm was not achieved. Therefore, standard maze IV surgery may be the best choice in patients with AFL and SHD.

Dynamic monitoring and regulation of pentachlorophenol photodegradation process by chemiluminescence and TiO2/PDA.

Pentachlorophenol (PCP), a highly toxic halogenated aromatic compound, and its direct photolysis or TiO2 photocatalysis may generate toxic intermediates and induce secondary pollution in the environment. It is urgently needed to design a strategy to inhibit the toxic intermediates in the photodegradation of PCP. To achieve this, polydopamine (PDA), a non-toxic substance, modified TiO2 (P25/PDA) nanoparticles were synthesized and used to improve the PCP photodegradation process. The dynamic tracking of toxic intermediates tetrachloro-1,4-benzoquinone (TCBQ) and trichlorohydroxy-1,4-benzoquinone (OH-TrCBQ) produced in the PCP photodegradation process were obtained by continuous flow chemiluminescence. Combined with reactive oxygen species (ROS) measurements, P25/PDA could approximatively depress 70 % TCBQ and 40 % OH-TrCBQ generation through the regulation of ROS especially the generation of a fairly large amount of H2O2 (about 30 µM) and O2- (about 20 µM) on the surface of the P25/PDA. The toxicity evaluation showed that the photodegradation of PCP by P25/PDA was a safer and green approach. Therefore, it was instructive to inhibit the formation of highly toxic intermediates in the photodegradation of environmental contaminants by regulating the ROS generated on the surface of the photocatalysts.

Rapid evaluation of oxygen vacancies-enhanced photogeneration of the superoxide radical in nano-TiO2 suspensions.

Reactive oxygen species (ROS) play an important role in the photocatalytic degradation of pollutants and are closely related to the surface defects of a semiconductor. However, the characterization of surface defects is very complex and a deeper understanding of them remains a great challenge. In this work, a series of nano-TiO2 was synthesized and their optical properties due to surface defects were studied. The results showed that the surface oxygen vacancies on nano-TiO2 can induce chemiluminescence (CL) by luminol. The greater the number of surface oxygen vacancies, the stronger the luminescence signal, and the greater the production of reactive oxygen species. Further studies revealed that the CL intensity was positively correlated with the oxygen vacancy content on the surface of nano-TiO2. Moreover, there was also a clear correlation between the oxygen vacancies and photogenerated superoxide radicals (O2˙-) on nano-TiO2 suspensions. Therefore, a simple and rapid CL method was developed for evaluating the oxygen vacancy content and their implied ability to photogenerate O2˙- on nano-TiO2 and has great potential in distinguishing surface oxygen vacancies and judging photocatalytic performance in oxides.

Surface Bridge Hydroxyl-Mediated Promotion of Reactive Oxygen Species in Different Particle Size TiO2 Suspensions.

Reactive oxygen species (ROS) play an essential role in TiO2 photocatalysis. They arise from the transfer of light-initiated carriers to the TiO2 surface and react with oxygen or water, in which the TiO2 surface is crucial. However, how the TiO2 surface affects ROS production is unclear. Herein, dynamic generation of ROS in suspensions of TiO2 of different particle sizes was investigated under ultraviolet-light irradiation. It is surprising to find that more ROS were produced more quickly for 100-140 nm TiO2 than for 20-60 nm TiO2. Further research suggested that ROS production was intrinsically correlated with the surface bridging hydroxyls per unit area. More bridging hydroxyls induced lower IEP and more negative charges on the TiO2 surface, which favored the transfer of photogenerated carriers, resulting in the promotion of ROS and photocatalytic activity. This provided insight into designing high-efficiency photocatalysts to solve the problem of small particle sizes causing loss and blockage in wastewater treatment.

Roles of reactive oxygen species (ROS) in the photocatalytic degradation of pentachlorophenol and its main toxic intermediates by TiO2/UV.

Pentachlorophenol (PCP) caused water quality problems owe to its past widespread application and stability, harmful to human health. Photocatalysis, which was mainly involved in the reactive oxygen species (ROS) reaction, has large potential as water treatment process. However, the roles of ROS on the degradation process of PCP are not yet clearly defined. The main objectives of this work were to investigate the roles of ROS involved in the whole degradation of PCP and main toxic intermediates and elucidate the degradation mechanisms. Tetrachloro-1,4-benzo/hydroquinone (TCBQ/TCHQ), trichlorohydroxy-1,4-benzoquinone (OH-TrCBQ) and 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone (OH-DCBQ) were identified as main intermediates. The roles of generated ROS including OH, O2- and H2O2 were systematically explored for the degradation of PCP and its main intermediates using radical quenchers. The results showed that, OH played the dominant role for the degradation of PCP, O2- played more contributing roles for the degradation of TCBQ, H2O2 exhibited major contribution for the degradation of OH-TrCBQ and OH-DCBQ. These results offered us an insight into the degradation mechanism of PCP involved with ROS. It can also serve as the basis for controlling and blocking the generation of highly toxic substances through regulating the ROS generation during the PCP degradation.

Internal concentrations of perfluorobutane sulfonate (PFBS) comparable to those of perfluorooctane sulfonate (PFOS) induce reproductive toxicity in Caenorhabditis elegans.

Perfluorobutane sulfonate (PFBS) is considered a less-toxic replacement for perfluorooctane sulfonate (PFOS), with multiple applications in industrial and consumer products. Previous studies comparing their toxicity generally used similar exposure levels, without taking internal concentrations into account. The current study compared the reproductive toxicity of PFOS and PFBS, at similar internal concentrations, to Caenorhabditis elegans (C. elegans). PFBS was much less bioaccumulative than PFOS. The 48-h median lethal concentrations (LC50) for PFOS and PFBS were 1.4 µM (95% confidence interval [CI]: 1.1-1.6) and 794 µM (95% CI: 624-1009), respectively. Egg production and brood number of C. elegans decreased markedly following exposure to 0.1 µM PFOS or 1000 or 1500 µM PFBS. Germ-cell apoptosis and production of reactive oxygen species increased significantly following exposure to 2 µM PFOS or 500 or 1000 µM PFBS. Expression of the antioxidant genes sod-3, ctl-2, and gst-4 and the pro-apoptotic genes egl-1 and ced-13 was altered significantly following PFOS and PFBS exposure. These findings indicate that both chemicals exert reproductive toxicity in C. elegans, probably owing to germ-cell apoptosis resulting from elevated levels of reactive oxygen species. The vastly different exposure concentrations of PFBS and PFOS used in this study produced similar internal concentrations, leading to the reproductive toxicities observed.