ABSTRACT
BACKGROUND: Chinese medaka (Oryzias sinensis) is widely distributed in freshwater rivers in China. Similar to the medaka (Oryzias latipes), Chinese medaka has the characteristics of small size, rapid reproductive cycle, and strong adaptability, which makes it suitable as a model organism for studies in basic biology and environmental toxicology. Chinese medaka exhibits distinct sexual dimorphism. However, due to the lack of complete genomic information, the regulation of sex determination and differentiation-related genes in Chinese medaka remains unclear. METHODS: Chinese medaka dmrt1 (Osdmrt1) was cloned by PCR, and transgenic individuals of medaka [Tg(CMV:Osdmrt1)] overexpressing Osdmrt1 were generated to investigate the role of Osdmrt1 in sex determination. Western blot was used to validate the integration of the Osdmrt1 into the medaka genome. Tissue sectioning and HE staining were used to identify Tg(CMV:Osdmrt1) physiological gender and phenotype. qRT-PCR was used to analyze the expression of gonad-specific genes. RESULTS: Osdmrt1 was cloned and identified, and it shared similar evolutionary relationships with medaka dmrt1. Tg(CMV:Osdmrt1) exhibited partial sex reversal from female to male in the F2 generation, with genetically female individuals developing testes and producing functional sperm. Additionally, the secondary sexual characteristics of the transgenic females also changed to males. CONCLUSION: The Chinese medaka dmrt1 gene could convert females to males in medaka. GENERAL SIGNIFICANCE: These results not only elucidate the function of Chinese medaka dmrt1, but also accumulate knowledge for studying the function of economically important fish genes in model fish by transgenic technology.
Subject(s)
Animals, Genetically Modified , Oryzias , Transcription Factors , Animals , Oryzias/genetics , Female , Male , Transcription Factors/genetics , Transcription Factors/metabolism , Sex Determination Processes/genetics , Fish Proteins/genetics , Fish Proteins/metabolism , East Asian PeopleABSTRACT
Upon encountering a virus, fish initiate an innate immune response, guided by IFNs. Foxo3 plays a part in the body's immune response; however, its specific role in the IFN-guided immune response in fish is yet to be clarified. In this study, we characterized foxo3 in Japanese medaka (Oryzias latipes) and examined its role in the IFN-dependent immune response upon infection with the RGNNV. The results show that the coding region of the medaka foxo3 gene is 2007 base pairs long, encoding 668 amino acids, and possesses a typical forkhead protein family structural domain. The product of this gene shares high homology with foxo3 in other fish species and is widely expressed, especially in the brain, eyes, testes, and heart. Upon RGNNV infection, foxo3-/- mutant larvae showed a lower mortality rate, and adults exhibited a significant reduction in virus replication. Moreover, the absence of foxo3 expression led to an increase in the expression of irf3, and a decrease in the expression of other IFN-related genes such as tbk1 and mapk9, implying that foxo3 may function as a negative regulator in the antiviral signaling pathway. These findings provide crucial insights for disease-resistant breeding in the aquaculture industry.
ABSTRACT
Nectins are adhesion molecules that play a crucial role in the organization of epithelial and endothelial junctions and function as receptors for the entry of herpes simplex virus. However, the role of Nectin4 remains poorly understood in fish. In this study, nectin4 gene was cloned from medaka (OlNectin4). OlNectin4 was located on chromosome 18 and contained 11 exons, with a total genome length of 25754 bp, coding sequences of 1689 bp, coding 562 amino acids and a molecular weight of 65.5 kDa. OlNectin4 contained four regions, including an Immunoglobulin region, an Immunoglobulin C-2 Type region, a Transmembrane region and a Coiled coil region. OlNectin4 shared 47.18 % and 25.00 % identity to Paralichthys olivaceus and Mus musculus, respectively. In adult medaka, the transcript of nectin4 was predominantly detected in gill. During red spotted grouper nervous necrosis virus (RGNNV) infection, overexpression of OlNectin4 in GE cells significantly increased viral gene transcriptions. Meanwhile, Two mutants named OlNectin4â³4 (+4 bp) and OlNectin4â³7 (-7 bp) medaka were established using CRISPR-Cas9 system. Nectin4-KO medaka had higher mortality than WT after infected with RGNNV. Moreover, the expression of RGNNV RNA2 gene in different tissues of the Nectin4-KO were higher than WT medaka after challenged with RGNNV. The brain and eye of Nectin4-KO medaka which RGNNV mainly enriched, exhibited significantly higher expression of interferon signaling genes than in WT. Taken together, the OlNectin4 plays a complex role against RGNNV infection by inducing interferon responses for viral clearance.
Subject(s)
Fish Diseases , Fish Proteins , Nectins , Nodaviridae , Oryzias , RNA Virus Infections , Animals , Oryzias/genetics , Oryzias/immunology , Nodaviridae/physiology , RNA Virus Infections/veterinary , RNA Virus Infections/immunology , Nectins/genetics , Nectins/immunology , Fish Proteins/genetics , Fish Proteins/immunology , Fish Proteins/chemistry , Fish Diseases/immunology , Fish Diseases/virology , Phylogeny , Amino Acid Sequence , Immunity, Innate/genetics , Sequence Alignment/veterinary , Gene Expression Regulation/immunology , Gene Expression Profiling/veterinaryABSTRACT
Light-stabilizing additives may contribute to the overall pollution load of microplastics (MPs) and potentially enter the food chain, severely threatening aquatic life and human health. This study investigated the variation between polystyrene (PS) MPs and phthalocyanine blue (CuPC)-containing MPs before and after photoaging, as well as their effects on Microcystis aeruginosa. The presence of PS-MPs increased cell mortality, antioxidant enzyme activity, and the variation in extracellular components, while the presence of CuPC exacerbated these variations. CuPC-containing MPs caused different increasing trends in superoxide dismutase and malondialdehyde activities due to electron transfer across the membrane. Transcriptomic analysis revealed that the MPs and CuPC affected various cellular processes, with the greatest impact being on cell membranes. Compared with MPs, CuPC negatively affected ribosome and polysaccharide formation. These findings provide insights into the molecular mechanisms underlying the cellular response to MPs and their associated light-stabilizer pollution and imply the necessity for mitigating the pollution of both MPs and light-stabilizers.
Subject(s)
Cyanobacteria , Indoles , Microcystis , Organometallic Compounds , Water Pollutants, Chemical , Humans , Microplastics/toxicity , Plastics/toxicity , Antioxidants , Polystyrenes , Water Pollutants, Chemical/toxicityABSTRACT
Infrared (IR) spectroscopy is a powerful technique for detecting and identifying Microplastics (MPs) in the environment. However, the aging of MPs presents a challenge in accurately identification and classification. To address this challenge, a classification model based on deep convolutional neural networks (CNNs) was developed using infrared spectra results. Particularly, original infrared (IR) spectra were used as the sample dataset, therefore, relevant spectral details were preserved and additional noise or distortions were not introduced. The Adam (Adaptive moment estimation) algorithm was employed to accelerate gradient descent and weight update, the Dropout function was implemented to prevent overfitting and enhance the generalization performance of the network. An activation function ReLu (Rectified Linear Unit) was also utilized to simplify the co-adaptation relationship among neurons and prevent gradient disappearance. The performance of the CNN model in MPs classification was evaluated based on accuracy and robustness, and compared with other machine learning techniques. CNN model demonstrated superior capabilities in feature extraction and recognition, and greatly simplified the pre-processing procedure. The identification results of aged commercial microplastic samples showed accuracies of 40 % for Artificial Neural Network, 60 % for Random Forest, 80 % for Deep Neural Network, and 100 % for CNN, respectively. The CNN architecture developed in this work also demonstrates versatility by being suitable for both limited data cases and potential expansion to include more discrete data in the future.
ABSTRACT
Despite decades of research on phenols oxidation by permanganate, there are still considerable uncertainties regarding the mechanisms accounting for the unexpected parabolic pH-dependent oxidation rate. Herein, the pH effect on phenols oxidation was reinvestigated experimentally and theoretically by highlighting the previously unappreciated proton transfer. The results revealed that the oxidation of protonated phenols occurred via proton-coupled electron transfer (PCET) pathways, which can switch from ETPT (electron transfer followed by proton transfer) to CEPT (concerted electron-proton transfer) or PTET (proton transfer followed by electron transfer) with an increase in pH. A PCET-based model was thus established, and it could fit the kinetic data of phenols oxidation by permanganate well. In contrast with what was previously thought, both the simulating results and the density functional theory calculation indicated the rate of CEPT reaction of protonated phenols with OH- as the proton acceptor was much higher than that of deprotonated phenols, which could account for the pH-rate profiles for phenols oxidation. Analysis of the quantitative structure-activity relationships among the modeled rate constants, Hammett constants, and pKa values of phenols further supports the idea that the oxidation of protonated phenols is dominated by PCET. This study improves our understanding of permanganate oxidation and suggests a new pattern of reactivity that may be applicable to other systems.
Subject(s)
Electrons , Protons , Hydrogen-Ion Concentration , Oxidation-Reduction , Electron Transport , Phenols , KineticsABSTRACT
Attention has been long focused on enhancing permanganate (Mn(VII)) oxidation capacity for eliminating organic contaminants via generating active manganese intermediates (AMnIs). Nevertheless, limited consideration has been given to the unnecessary consumption of Mn(VII) due to the spontaneous disproportionation of AMnIs during their formation. In this work, we innovatively introduced green polyaspartic acid (PASP) as both reducing and chelating agents to activate Mn(VII) to enhance the oxidation capacity and utilization efficiency of Mn(VII). Multiple lines of evidence suggest that Mn(III), existing as Mn(III)-PASP complex, was generated and dominated the degradation of bisphenol A (BPA) in the Mn(VII)/PASP system. The stabilized Mn(III) species enabled Mn(VII) utilization efficiency in the Mn(VII)/PASP system to be higher than that in Mn(VII) alone. Moreover, the electrophilic Mn(III) species was verified to mainly attack the inclusive benzene ring and isopropyl group to realize BPA oxidation and its toxicity reduction in the Mn(VII)/PASP system. In addition, the Mn(VII)/PASP system showed the potential for selectively oxidizing organic contaminants bearing phenol and aniline moieties in real waters without interference from most of coexisting water matrices. This work brightens an overlooked route to both high oxidation capacity and efficient Mn(VII) utilization in the Mn(VII)-based oxidation processes.
ABSTRACT
The selective oxygenation of ubiquitous C(sp3 )-H bonds remains a highly sought-after method in both academia and the chemical industry for constructing functionalized organic molecules. However, it is extremely challenging to selectively oxidize a certain C(sp3 )-H bond to afford alcohols due to the presence of multiple C(sp3 )-H bonds with similar strength and steric environment in organic molecules, and the alcohol products being prone to further oxidation. Herein, we present a practical and cost-efficient electrochemical method for the highly selective monooxygenation of benzylic C(sp3 )-H bonds using continuous flow reactors. The electrochemical reactions produce trifluoroacetate esters that are resistant to further oxidation but undergo facile hydrolysis during aqueous workup to form benzylic alcohols. The method exhibits a broad scope and exceptional site selectivity and requires no catalysts or chemical oxidants. Furthermore, the electrochemical method demonstrates excellent scalability by producing 115â g of one of the alcohol products. The high site selectivity of the electrochemical method originates from its unique mechanism to cleave benzylic C(sp3 )-H bonds through sequential electron/proton transfer, rather than the commonly employed hydrogen atom transfer (HAT).
ABSTRACT
Mn(II) exhibits a superb ability in activating periodate (PI) for the efficient degradation of aqueous organic contaminants. Nevertheless, ambiguous conclusions regarding the involved reactive species contributing to the removal of organic contaminants remain unresolved. In this work, we found that the Mn(II)/PI process showed outstanding and selective reactivity for oxidizing sulfonamides with the removal ranging from 57.1% to 100% at pH 6.5. Many lines of evidence suggest that the in-situ formed colloidal MnO2 (cMnO2) served as a catalyst to mediate electron transfer from sulfonamides to PI on its surface via forming cMnO2-PI complex (cMnO2-PI*) for the efficient oxidation of sulfonamides in the Mn(II)/PI process. Experimental results and density functional theory (DFT) calculations verify that the inclusive aniline moiety was the key site determining the electron transfer-dominated oxidation of sulfonamides. Furthermore, DFT calculation results reveal that the discrepancies in the removal of sulfonamides in the Mn(II)/PI process were attributed to different kinetic stability and chemical reactivity of sulfonamides caused by their heterocyclic substituents. In addition, a high utilization efficiency of PI was achieved in the Mn(II)/PI process owing to the surface-mediated electron transfer mechanism. This work provides deep insights into the surface-promoted mechanism in the cMnO2-involved oxidation processes.
Subject(s)
Anti-Bacterial Agents , Manganese Compounds , Oxides , Electrons , Oxidation-Reduction , Sulfanilamide , SulfonamidesABSTRACT
pax6 is a canonic master gene for eye formation. Knockout of pax6 affects the development of craniofacial skeleton and eye in mice. Whether pax6 affects the development of spinal bone has not been reported yet. In the present study, we used CRISPR/Cas9 system to generate Olpax6.1 mutant in Japanese medaka. Phenotype analysis showed that ocular mutation caused by the Olpax6.1 mutation occurred in the homozygous mutant. The phenotype of heterozygotes is not significantly different from that of wild-type. In addition, knockout Olpax6.1 resulted in severe curvature of the spine in the homozygous F2 generation. Comparative transcriptome analysis and qRT-PCR revealed that the defective Olpax6.1 protein caused a decrease in the expression level of sp7, col10a1a, and bglap, while the expression level of xylt2 did not change significantly. The functional enrichment of differentially expressed genes (DEGs) using the Kyoto Encyclopedia of Genes and Genomes database showed that the DEGs between Olpax6.1 mutation and wild-type were enriched in p53 signaling pathway, extracellular matrix (ECM) -receptor interaction, et al. Our results indicated that the defective Olpax6.1 protein results in the reduction of sp7 expression level and the activation of p53 signaling pathway, which leads to a decrease in the expression of genes encoding ECM protein, such as collagen protein family and bone gamma-carboxyglutamate protein, which further inhibits bone development. Based on the phenotype and molecular mechanism of ocular mutation and spinal curvature induced by Olpax6.1 knockout, we believe that the Olpax6.1-/- mutant could be a potential model for the study of spondylo-ocular syndrome.
Subject(s)
Oryzias , Animals , Mice , Oryzias/genetics , Oryzias/metabolism , Mice, Knockout , Tumor Suppressor Protein p53/genetics , MutationABSTRACT
Gene duplication provides raw material for the evolution of genetic and phenotypic complexity. It has remained a long-standing mystery how duplicated genes evolve into new genes by neofunctionalization via the acquisition of new expression and/or activity and simultaneous loss of the old expression and activity. Fishes have many gene duplicates from whole genome duplication, making them excellent for studying the evolution of gene duplicates. In the fish medaka (Oryzias latipes), an ancestral pax6 gene has given rise to Olpax6.1 and Olpax6.2. Here we report that medaka Olpax6.2 is evolving towards neofunctionalization. A chromosomal syntenic analysis indicated that Olpax6.1 and Olpax6.2 are structurally co-homologous to the single pax6 in other organisms. Interestingly, Olpax6.2 maintains all conserved coding exons but loses the non-coding exons of Olpax6.1, and has 4 promoters versus 8 in Olpax6.1. RT-PCR revealed that Olpax6.2 maintains expression in the brain eye, pancreas as Olpax6.1. Surprisingly, Olpax6.2 also exhibits maternal inheritance and gonadal expression by RT-PCR, in situ hybridization and RNA transcriptome analysis. The expression and distribution of Olpax6.2 is not different from Olpax6.1 in the adult brain, eye and pancreas, but exhibited overlapping and distinct expression in early embryogenesis. We show that ovarian Olpax6.2 expression occurs in female germ cells. Olpax6.2 knockout shows no obvious defect in eye development, while Olpax6.1 F0 mutant have severe defects in eye development. Thus, Olpax6.2 acquires maternal inheritance and germ cell expression, but functionally degenerates in the eye, making this gene as an excellent model to study the neofunctionalization of duplicated genes.
Subject(s)
Oryzias , Animals , Female , Oryzias/genetics , Oryzias/metabolism , Maternal Inheritance , RNA/genetics , In Situ Hybridization , Germ CellsABSTRACT
The direct hydroxylation of arene C-H bonds is a highly sought-after transformation but remains an unsolved challenge due to the difficulty in efficient and regioselective C-H oxygenation and high reactivity of the phenolic products leading to overoxidation. Herein we report electrochemical C-H hydroxylation of arenes in continuous flow for the synthesis of phenols. The method is characterized by broad scope (compatible with arenes of diverse electronic properties), mild conditions without any catalysts or chemical oxidants, and excellent scalability as demonstrated by the continuous production of 1 mol (204 grams) of one of the phenol products.
Subject(s)
Oxidants , Phenols , Catalysis , Hydroxylation , Oxidants/chemistry , Phenols/chemistryABSTRACT
Although periodate-based advanced oxidation processes have been proven to be efficient in abating organic contaminants, the activation properties of different periodate species remain largely unclear. Herein, by highlighting the role of H4IO6-, we reinvestigated the pH effect on the decontamination performance of the H2O2/periodate process. Results revealed that elevating pH from 2.0 to 10.0 could markedly accelerate the rates of organic contaminant decay but decrease the amounts of organic contaminant removal. This pH-dependent trend of organic contaminant degradation corresponded well with the HO· yield and the variation of periodate species. Specifically, although 1O2 could be detected at pH 9.0, HO· was determined to be the major reactive oxidizing species in the H2O2/periodate process under all the tested pH levels. Furthermore, it was suggested that only H4IO6- and H2I2O104- could serve as the precursors of HO·. The second-order rate constant for the reaction of H2I2O104- species with H2O2 was determined to be â¼1199.5 M-1 s-1 at pH 9.0, which was two orders of magnitude greater than that of H4IO6- (â¼2.2 M-1 s-1 at pH 3.0). Taken together, the reaction pathways of H2O2 with different periodate species were proposed. These fundamental findings could improve our understanding of the periodate-based advanced oxidation processes.
Subject(s)
Hydrogen Peroxide , Water Pollutants, Chemical , Hydrogen Peroxide/chemistry , Hydrogen-Ion Concentration , Kinetics , Oxidation-Reduction , Periodic Acid , Ultraviolet Rays , Water Pollutants, Chemical/chemistryABSTRACT
Generation of mutants with clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) is commonly carried out in fish species by co-injecting a mixture of Cas9 messenger RNA (mRNA) or protein and transcribed guide RNA (gRNA). However, the appropriate expression system to produce functional gRNAs in fish embryos and cells is rarely present. In this study, we employed a poly-transfer RNA (tRNA)-gRNA (PTG) system driven by cytomegalovirus (CMV) promoter to target the medaka (Oryzias latipes) endogenous gene tyrosinase(tyr) or paired box 6.1 (pax6.1) and illustrated its function in a medaka cell line and embryos. The PTG system was combined with the CRISPR/Cas9 system under high levels of promoter to successfully induce gene editing in medaka. This is a valuable step forward in potential application of the CRISPR/Cas9 system in medaka and other teleosts.
Subject(s)
Gene Editing , Oryzias , Animals , CRISPR-Cas Systems , Cell Line , Oryzias/genetics , RNA, Guide, Kinetoplastida/genetics , RNA, Transfer/geneticsABSTRACT
The study was carried out to analyze the factors influencing the elevated serum procalcitonin (PCT) levels during the early phase of extensive burn, and to investigate its potential for sepsis prediction and prognosis. Clinical data of 324 patients with extensive burns treated at our department from July 2014 to December 2019 were retrospectively analyzed. Approximately half of the patients (50.93%) exhibited elevated serum PCT concentrations during the early phase, and elevated PCT levels may not be caused by infections. Early-phase PCT level was an independent risk factor for sepsis occurrence in extensive-burn patients within 60 days of injury. Burn index, degree of inhalation injury, and APACHE-II score influenced PCT level elevation during the early phase. Patient age, burn index, APACHE-II score at admission, early-phase PCT level, and sepsis occurrence were risk factors for mortality in extensive-burn patients. During the early phase, approximately 50.93% of the extensive-burn patients exhibited elevated PCT levels, which were associated with non-infectious factors. As elevated PCT level during the early phase predicted sepsis occurrence within 60 days of injury and was significantly associated with patient mortality, it might be a potential burn severity indicator during the early phase of burn injury.
Subject(s)
Burns , Procalcitonin/blood , Sepsis , Biomarkers/blood , Burns/diagnosis , Humans , Prognosis , Retrospective StudiesABSTRACT
Lead pollution has become a global concern due to its ubiquity and persistence. This study describes two FeMn oxide substrate adsorbents, namely, FeMn binary oxides (FMBO) and mesoporous FeMn binary oxide (MFMBO) covered with tannic acid film (FMBO@TA-Fe3+ and MFMBO@TA-Fe3+), for the treatment of Pb2+ in water. The characterization results showed that TA was successfully coated onto the surfaces of FMBO and MFMBO. The maximum capacities of Pb2+ on FMBO@TA-Fe3+ and MFMBO@TA-Fe3+ were 322.08 and 357.14 mg g-1, respectively, which were twice those of FMBO and MFMBO. The adsorption of Pb2+ on the adsorbents was a spontaneous, endothermic process with increasing disorder through thermodynamics studies. An overall mechanism was proposed for Pb2+ adsorption, the improved adsorption performance of FMBO@TA-Fe3+ and MFMBO@TA-Fe3+ is ascribed to the mesoporous characteristics and the introduction of hydroxyl groups. Further investigation indicated the adsorption of Pb2+ could be attributed to electrostatic interactions on FMBO@TA-Fe3+ and MFMBO@TA-Fe3+, and cation exchange existed through the formation of these internal surface complexes. The Pb2+-loaded adsorbents could be effectively desorbed in a dilute hydrochloric acid solution, promoting recycling and reuse of the regenerated adsorbents. These results warrant the promising application of FMBO@TA-Fe3+ and MFMBO@TA-Fe3+ for the removal of Pb2+, and this work first proposed TA film-modified FMBO and MFMBO to improve its adsorption capacity in the application of environmental remediation.
ABSTRACT
The direction of microskin transplantation is difficult to control, and the survival rate is critically affected. In this study, we show for the first time that survival rate of transplantation was improved by changing the direction of microskin. A human split-thickness skin graft was prepared as microskin (size of 1 mm × 1 mm), and was transplanted onto a wound in nude mice. The effect of the orientation of microskin on the survival rate of transplants was observed. The collagen membrane was first attached to the epidermal surface of pig skin, which was then cut into microskin and then they were floated on physiological saline. The effect of the collagen membrane on the orientation of microskin was observed. Then the microskin of pig with an epidermal surface attached to the collagen membrane was transplanted to the wound of the pig, and the survival rate of transplants was observed. In the 2nd, 3rd and 4th week after transplantation of nude mice, the wound healing rate in group A (all of the microskin's epidermal surface was upward) was significantly higher than in other groups (P < 0.01). The floating rate and the forward floating rate in the experimental group were significantly higher than those in the control group (P < 0.01). Four weeks after microskin transplantation of pigs, the wound contraction rate in group A, compared with group B, was significantly lower, and the wound healing rate was significantly higher (P < 0.01). In microskin grafting, the direction of microskin significantly affects the survival rate of transplantation. The method of adhering the collagen membrane to the epidermal surface of microskin may ensure complete floating of microskin on the physiological saline with the epidermal surface facing up. This is a new method to improve the survival rate of microskin grafting.
ABSTRACT
Bismuth oxyiodide (BiOI) has garnered intense attention in the field of photocatalysis for environmental remediation; however, it suffers from a high electron-hole recombination rate. In this study, for the first time, we report on a facile strategy for the creation of oxygen vacancies in BiOI via strontium (Sr2+) doping. The as-prepared 0.45-SrBiOI demonstrated significantly enhanced photocatalytic degradation of indometacin under visible light exposure, which was almost 10 folds higher than pristine BiOI. This augmented photocatalytic performance was ascribed to the accelerated separation of charge carriers by oxygen vacancies, as well as Sr ion trapping electrons. Reactive species determination experiments revealed that O2âª-, 1O2, and h+ were the dominant active species. Finally, potential indometacin degradation pathways were proposed based on the identification of degradation by-products and theoretical calculations. This study offers new perspectives for the synthesis of highly efficient and cost effective BiOI-based photocatalysts, and provides a promising strategy toward advanced environmental remediation.
ABSTRACT
Achieving efficient solar utilization is a primary goal in the field of photocatalytic degradation of PPCPs. For this study, a broad-spectrum carbon and oxygen doped, porous g-C3N4 (COCN) was synthesized via a simple co-pyrolysis of dicyandiamide and methylamine hydroiodide (CH5N·HI). The 0.3COCN demonstrated an excellent photocatalytic degradation of indometacin (IDM), which was 5.9 times higher than bulk g-C3N4. The enhanced photocatalytic activity could be ascribed to the broad-spectrum utilization of solar light and improved charge separation efficiency. Reactive species (RSs) scavenging experiments have shown that O2·- and 1O2 were the dominant active species. Further, the 0.3COCN exhibits excellent yield of hydroxyl radicals which was confirmed by electron spin resonance (ESR) spectra. Meanwhile, the degradation pathways of IDM were proposed according the HRAM LC-MS/MS and total organic carbon (TOC). This research provided a new strategy for a broad-spectrum photocatalyst, and a promising strategy for environmental remediation.
Subject(s)
Indomethacin/analysis , Light , Nitriles/chemistry , Oxygen/chemistry , Photolysis , Water Pollutants, Chemical/analysis , Catalysis , Electron Transport/radiation effects , Hydrogen Peroxide/chemistry , Nitriles/radiation effects , Oxidation-Reduction , Porosity , Surface PropertiesABSTRACT
INTRODUCTION: Blast injuries are complex types of physical trauma resulting from direct or indirect exposure to an explosion, which can be divided into four classes: primary, secondary, tertiary, and quaternary. Primary blast injury results in damage, principally, in gas-containing organs such as the lungs (blast lung injury, BLI). BLI is defined as radiological and clinical evidence of acute lung injury occurring within 12h of exposure to an explosion and not due to secondary or tertiary injury. BLI often combines with cutaneous thermal injury, a type of quaternary blast injury, either in terrorist bomb attacks or in civilian accidental explosions. This report summarizes our experience in the management of combined massive burn and BLI at a Shanghai Burn Center in China. METHODS: A retrospective observational analysis of clinical data was performed for massive burn patients with or without BLI during a 20-year interval. Patient characteristics, causes of injury, clinical parameters, management, and outcomes were recorded and evaluated. RESULTS: A total of 151 patients (120 males and 31 females) with severe burn injury (≥50% TBSA) treated at the Burn Center of Changhai Hospital in Shanghai between July 1997 and June 2017 were enrolled in this study. Their mean age was 38.6±17.8 (3-75) years. Among them, 28 patients had combined BLI and burn injury and 39 patients had no BLI or smoke inhalation injury (non-BLI-SII). No significant difference was observed in the burn area or full-thickness burn area between the two groups. The lowest PaO2/fraction of inspired oxygen (FiO2) ratio during the first 24h in BLI patients was significantly lower than that in non-BLI-SII patients. Exudative changes were observed by X-ray radiography in all BLI patients but not in non-BLI-SII patients within 6h after injury. A significantly higher proportion of colloids were used for fluid resuscitation in BLI patients than that in non-BLI-SII patients. A higher proportion and longer time of mechanical ventilation were needed for BLI patients than those for non-BLI-SII patients, and a higher proportion of patients received sedative agents in the BLI group than those in the non-BLI-SII group. The first escharectomy was performed relatively later in BLI patients than in non-BLI-SII patients because of more time taken by BLI patients to recover from lung injury. The length of ICU and hospital stay in BLI patients was significantly longer than that in non-BLI-SII patients. No significant difference in the overall mortality was detected between these two groups. CONCLUSION: It is a formidable challenge for clinicians to diagnose and manage massive burn patients combined with BLI. A comprehensive treatment approach is strongly recommended, including fluid resuscitation, airway management, mechanical ventilation, and surgical treatment. Given the high mortality of massive burn patients combined with BLI even in a recognized burn center, more prospective studies are encouraged to assess more effective strategies for the treatment of such patients.