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Recently, various biosensors based on odorant-binding proteins (OBPs) were developed for the detection of odorants and pheromones. However, important data gaps exist regarding the sensitive and selective detection of aldehydes with various carbon numbers. In this work, an OBP2a-based electrochemical impedance spectroscopy (EIS) biosensor was developed by immobilizing OBP2a on a gold interdigital electrode, and was characterized by EIS and atomic force microscopy. EIS responses showed the OBP2a-based biosensor was highly sensitive to citronellal, lily aldehyde, octanal, and decanal (detection limit of 10-11 mol/L), and was selective towards aldehydes compared with interfering odorants such as small-molecule alcohols and fatty acids (selectivity coefficients lower than 0.15). Moreover, the OBP2a-based biosensor exhibited high repeatability (relative standard deviation: 1.6%-9.1 %, n = 3 for each odorant), stability (NIC declined by 3.6 % on 6th day), and recovery (91.2%-96.6 % on three real samples). More specifically, the sensitivity of the biosensor to aldehydes was positively correlated to the molecular weight and the heterocyclic molecule structure of the odorants. These results proved the availability and the potential usage of the OBP2a-based EIS biosensor for the rapid and sensitive detection of aldehydes in aspects such as medical diagnostics, food and favor analysis, and environmental monitoring.
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Aldeídos , Técnicas Biossensoriais , Receptores Odorantes , Técnicas Biossensoriais/métodos , Aldeídos/química , Aldeídos/análise , Receptores Odorantes/química , Receptores Odorantes/metabolismo , Técnicas Eletroquímicas , Eletrodos , Limite de Detecção , Odorantes/análise , Ouro/química , Espectroscopia DielétricaRESUMO
Herein, we investigated the trophic transfer of mercury (Hg) through food chains in different habitats (namely aquatic, riparian, and terrestrial) through bulk stable isotope analysis of nitrogen (δ15Nbulk) and compound-specific isotope analysis of nitrogen in amino acids (δ15NAA) using bird feathers and their potential food sources from a Hg-contaminated site in southwest China. Results showed similar δ15Nphe for water birds (4.7 ± 2.6 ) and aquatic food sources (5.2 ± 2.1 ) and for land-based food sources (10.1 ± 0.4 ) and terrestrial birds (11.6 ± 3.0 ), verifying δ15Nphe as a potential discriminant indicator for different food sources. The trophic positions (TPs) of most organisms based on δ15Nbulk (TPbulk) tended to overestimate compared with those based on δ15NAA (TPAA), especially for predators (such as kingfisher: ΔTP = 1.3). Additionally, significant differences were observed in the aquatic, riparian, and terrestrial food webs between trophic magnification slope (TMS)bulk and TMSAA (p < 0.05). The trophic magnification factor (TMF)AA-multiple based on multiple-AAs in three food webs were higher than the TMFAA and TMFbulk, probably because of the greater variation of δ15Nbaseline, complex food sources or the notably different in individual organisms. Altogether, our results improve the understanding of Hg trophic transfer in aquatic, riparian, and terrestrial food webs.
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Aminoácidos , Aves , Monitoramento Ambiental , Plumas , Cadeia Alimentar , Mercúrio , Isótopos de Nitrogênio , Animais , Mercúrio/análise , Aminoácidos/química , Aminoácidos/análise , Plumas/química , Ecossistema , China , Poluentes Químicos da Água/análiseRESUMO
Compound-specific isotope analysis of nitrogen in amino acids (CSIA-AA, δ15NAA) has gained increasing popularity for elucidating energy flow within food chains and determining the trophic positions of various organisms. However, there is a lack of research on the impact of hydrolysis conditions, such as HCl concentration and hydrolysis time, on δ15NAA analysis in biota samples. In this study, we investigated two HCl concentrations (6 M and 12 M) and four hydrolysis times (2 h, 6 h, 12 h, and 24 h) for hydrolyzing and derivatizing AAs in reference materials (Tuna) and biological samples of little egret (n = 4), night heron (n = 4), sharpbelly (n = 4) and Algae (n = 1) using the n-pivaloyl-iso-propyl (NPIP) ester approach. A Dowex cation exchange resin was used to purify amino acids before derivatization. We then determined δ15NAA values using gas chromatography-combustion-isotope ratio mass spectrometry (GC-C-IRMS). The results revealed no significant differences (p > 0.05) in δ15NAA values among samples treated with different HCl concentrations or hydrolysis times, particularly for δ15NGlx (range: 21.0-23.5) and δ15NPhe (range: 4.3-5.4) in Tuna (12 M). Trophic positions (TPs) calculated based on δ15NAA at 2 h (little egret: 2.9 ± 0.1, night heron: 2.8 ± 0.1, sharpbelly: 2.0 ± 0.1 and Algae: 1.3 ± 0.2) were consistent with those at 24 h (3.1 ± 0.1, 2.8 ± 0.1, 2.2 ± 0.1 and 1.1 ± 0.1, respectively), suggesting that a 2-h hydrolysis time and a 6 M HCl concentration are efficient pretreatment conditions for determining δ15NAA and estimating TP. Compared to the currently used hydrolysis conditions (24 h, 6 M), the proposed conditions (2 h, 6 M) accelerated the δ15NAA assay, making it faster, more convenient, and more efficient. Further research is needed to simplify the operational processes and reduce the time costs, enabling more efficient applications of CSIA-AA.
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Aminoácidos , Cadeia Alimentar , Isótopos de Nitrogênio , Hidrólise , Aminoácidos/análise , Aminoácidos/química , Animais , Isótopos de Nitrogênio/análise , Ácido Clorídrico/química , AtumRESUMO
Ulcerative colitis(UC) is one of the common gastrointestinal diseases worldwide. In recent years, the incidence of UC has been continuously increasing, seriously threatening the health of people globally. It thus has become an urgent problem that needs to be addressed. There is research evidence that intestinal mucosal barrier dysfunction, including changes in intestinal stem cell secretion lineage, mucosal layer damage, disruption of cell junctions, overactive immune function, and imbalanced gut microbiota, is an important pathogenic factor and molecular basis of UC. The Notch signaling pathway is a highly conserved signaling pathway in eukaryotes during evolution, which transmits signals through cell connections between adjacent cells, affecting a series of processes such as cell proliferation, differentiation, development, migration, and apoptosis. Therefore, the Notch signaling pathway can regulate intestinal stem cells, CD4~+T cells, innate lymphoid cells(ILCs), macrophages(MØ), and intestinal microbiota and thus affect the chemical, physical, immune, and biological mucosal barriers of the intestinal mucosa. Its function is extensive and unique, different from those signaling pathways that mainly focus on anti-inflammatory and antioxidant stress. It can explain the therapeutic effects of traditional Chinese medicine from different perspectives. This article reviewed the role of the Notch1 signaling pathway in the pathogenesis of UC and the relevant literature on the targeted prevention and treatment of UC with traditional Chinese medicine, so as to provide new targets and theoretical support for further research on the effective prevention and treatment of UC.
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Colite Ulcerativa , Receptor Notch1 , Transdução de Sinais , Humanos , Transdução de Sinais/efeitos dos fármacos , Colite Ulcerativa/tratamento farmacológico , Colite Ulcerativa/imunologia , Colite Ulcerativa/metabolismo , Receptor Notch1/metabolismo , Receptor Notch1/genética , Animais , Medicamentos de Ervas Chinesas/farmacologia , Medicina Tradicional ChinesaRESUMO
Source characteristics and health risks of indoor organophosphate esters (OPEs) are limited by the lack of knowledge on emission processes. This study attempted to integrate the contents and emissions of OPEs from indoor building materials to assess human health effects. Thirteen OPEs were investigated in 80 pieces of six categories of building materials. OPEs are ubiquitous in the building materials and ∑13OPE contents varied significantly (p < 0.05) from 72.8 ng/g (seam agent) to 109,900 ng/g (wallpaper). Emission characteristics of OPEs from the building materials were examined based on a microchamber method. Depending on the sample category, the observed initial area-specific emission rates of ∑13OPEs varied from 154 ng/m2/h (carpet) to 2760 ng/m2/h (wooden floorboard). Moreover, the emission rate model was developed to predict the release levels of individual OPEs, quantify source contributions, and assess associated exposure risks. Source apportionments of indoor OPEs exhibited heterogeneities in multiple environmental media. The joint OPE contribution of wallpaper and wooden floorboard to indoor dust was up to 94.8%, while latex paint and wooden floorboard were the main OPE contributors to indoor air (54.2%) and surface (76.1%), respectively. Risk assessment showed that the carcinogenic risks of tris(2-chloroethyl) phosphate (3.35 × 10-7) were close to the acceptable level (1 × 10-6) and deserved special attention.
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Monitoramento Ambiental , Retardadores de Chama , Humanos , Ésteres/análise , Retardadores de Chama/análise , China , Organofosfatos/análise , Poeira/análise , Materiais de ConstruçãoRESUMO
Mercury (Hg) exposure is increasing in terrestrial birds; however, studies on its sources are scarce. In the present study, we elucidated the food composition of green-backed tit nestlings from three urban forest parks (CPL, AHL, and LCG) using live videography observation (LVO). Furthermore, the daily dietary intakes of inorganic Hg (IHg) (MDIIHg) and methylmercury (MeHg) (MDIMeHg) were determined using the Bayesian isotope mixing model (BIMM) to uncover the nestlings' specific dietary Hg contribution. Both LVO and BIMM indicated that Lepidoptera (primarily caterpillar) constituted the primary food source for the nestlings in the three forests, accounting for approximately 60% of their diet in all three forest parks. The estimated MDI of Hg revealed that lepidopterans and spiders primarily contributed to IHg exposure, with a co-contribution ratio of 71.8%-97.7%. Unexpectedly, dietary MeHg was mostly derived from spiders; the highest contribution ratio of 93.6% was recorded at CPL, followed by another peak ratio of 92.9% at LCG. However, the dietary exposure was primarily IHg, accounting for 69.8% (AHL), 62.0% (LCG), and 61.3% (CPL) of the nestlings. Our study findings highlight the importance of dietary IHg transfer in evaluating the effects of Hg in nestlings. LVO, coupled with BIMM, is an effective tool for determining the food compositions of songbird nestlings and estimating the contribution of specific diets.
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Mercúrio , Compostos de Metilmercúrio , Aves Canoras , Animais , Mercúrio/análise , Teorema de Bayes , Monitoramento Ambiental , Dieta , IsótoposRESUMO
Tire road wear particles (TRWPs) are a large source of microplastics in the environment, while the quantification of TRWPs is still challenging due to the complex interferences and the uncertainties and inconsistencies among different methods. This study developed a TRWPs quantification method using optimized pretreatments and bonded-sulfur as marker. Road dust samples (n = 48) were collected, pretreatments including density separation, digestion and extraction were optimized to remove interferences of the bonded-sulfur (minerals, sulfur-containing proteins, hydrosoluble/hydrophobic sulfur-containing substances). Presence of TRWPs in the samples was confirmed by microscopy and scanning electron microscopyenergy dispersive spectrometry. Bonded-sulfur in the samples were quantified by inductively coupled plasmamass spectrometry (ICPMS). Additionally, bonded-sulfur in tire wear particles (TWPs) abraded from tires of top 10 best-selling brands were measured to calculate conversion factor (1.1 ×104 µg/g) for the quantification of TRWPs in real samples. TRWPs contents were 5.40 × 104 µg/g11.02 × 104 µg/g and 2.36 × 104 µg/g5.30 × 104 µg/g in samples from heavy and light traffic roads, respectively. The method provided better recoveries (88-107%, n = 18) and repeatability (RSD=2.0-7.9%, n = 3) compared to methods using rubber, benzothiazole and organic zinc as markers. Furthermore, stability of the bonded-sulfur was validated by Raman and ICPMS. Thus, this accurate and stable quantification method could promote research on TRWPs.
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AIM: The study aimed to study the potential roles and mechanisms of shikonin in gastric cancer by network pharmacology and biological experiments. METHODS: The key genes and targets of shikonin in gastric cancer were predicted by network pharmacology and molecular docking study. The effect of shikonin on the proliferation, migration, and invasion of gastric cancer cells was detected by the CCK8 method, and wound healing and transwell assays. The expression levels of c-Myc and Yap-1 were detected via western blotting in gastric cancer cells after shikonin intervention. RESULTS: The results of network pharmacology revealed the key target genes of shikonin on gastric cancer cells to be c-Myc, Yap-1, AKT1, etc. GO and KEGG analysis showed regulation of cell migration, proliferation, adhesion, and other biological processes, including the PI3K-Akt signaling pathway, HIF-1 signaling pathway, necroptosis, and other cancer pathways. Molecular docking showed shikonin to be most closely combined with protooncogenes c-Myc and Yap-1. In vitro experiments showed that the proliferation rate, migration, and invasion ability of the gastric cancer cell group decreased significantly after shikonin intervention for 24h. The expression levels of c-Myc and Yap-1 in gastric cancer cells were found to be significantly decreased after shikonin intervention. CONCLUSION: This study showed protooncogenes c-Myc and Yap-1 to be the core target genes of shikonin on gastric cancer cells. Shikonin may suppress gastric cancer cells by inhibiting the protooncogenes c-Myc and Yap-1. This suggests that shikonin may be a good candidate for the treatment of gastric cancer.
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Indoor decoration generates a large number of volatile organic compounds (VOCs), which are simultaneously released from different paints. Nevertheless, the interaction mechanism of pollutant diffusion from multisource building materials (such as primer and finish) needs to be examined. In this paper, a multisource mass transfer model for VOC emissions from different combinations of paints is established, and the analytical solution is derived. The finite difference method is used to simulate the experimental results of VOC release in the environmental chambers, and its convergence and stability are verified. Using the optimization parameters of the single-source model and the law of conservation of mass, the key parameters of the multisource mass transfer model are obtained. The results show that the established model is in excellent agreement with both experimental data and literature data. In addition, the Little number Lt is used to analyse the change trend from the initial released concentration in the single-source and multisource models.
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In this study, pristine kiwi peel (KP) and nitric acid modified kiwi peel (NA-KP) based adsorbents were prepared and evaluated for selective removal of cationic dye. The morphology and chemical structure of KP and NA-KP were fully characterized and compared, and results showed nitric acid modification introduced more functional groups. Moreover, the adsorption kinetics and isotherms of malachite green (MG) by KP and NA-KP were investigated and discussed. The results showed that the adsorption process of MG onto KP followed a pseudo-second-order kinetic model and the Langmuir isotherm model, while the adsorption process of MG onto NA-KP followed a pseudo-first-order kinetic model and the Freundlich isotherm model. Notably, the Langmuir maximum adsorption capacity of NA-KP was 580.61 mg g-1, which was superior to that of KP (297.15 mg g-1). Furthermore, thermodynamic studies demonstrated the feasible, spontaneous, and endothermic nature of the adsorption process of MG by NA-KP. Importantly, NA-KP showed superior selectivity to KP towards cationic dye MG against anionic dye methyl orange (MO). When the molar ratio of MG/MO was 1:1, the separation factor (αMG/MO) of NA-KP was 698.10, which was 5.93 times of KP. In addition, hydrogen bonding, π-π interactions, and electrostatic interaction played important roles during the MG adsorption process by NA-KP. This work provided a low-cost, eco-friendly, and efficient option for the selective removal of cationic dye from dyeing wastewater.
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Corantes , Poluentes Químicos da Água , Corantes/química , Adsorção , Ácido Nítrico , Corantes de Rosanilina/química , Termodinâmica , Cinética , Poluentes Químicos da Água/química , Concentração de Íons de HidrogênioRESUMO
Ulcerative colitis is a common digestive disorder worldwide, with increasing incidence in recent years. It is an urgent problem to be solved, as it seriously affects and threatens the health and life of the global population. Studies have shown that dysfunction of the intestinal mucosal barrier is a critical pathogenic factor and molecular basis of ulcerative colitis, and some scholars have described it as a "barrier organ disease." While the Notch signalling pathway affects a series of cellular processes, including proliferation, differentiation, development, migration, and apoptosis. Therefore, it can regulate intestinal stem cells, CD4+ T cells, innate lymphoid cells, macrophages, and intestinal microbiota and intervene in the chemical, physical, immune, and biological mucosal barriers in cases of ulcerative colitis. The Notch signalling pathway associated with the pathogenesis of ulcerative colitis has distinct characteristics, with good regulatory effects on the mucosal barrier. However, research on ulcerative colitis has mainly focused on immune regulation, anti-inflammatory activity, and antioxidant stress; therefore, the study of the Notch signalling pathway suggests the possibility of understanding the pathogenesis of ulcerative colitis from another perspective. In this article we explore the role and mechanism of the Notch signalling pathway in the pathogenesis of ulcerative colitis from the perspective of the intestinal mucosal barrier to provide new targets and theoretical support for further research on the pathogenesis and clinical treatment of ulcerative colitis.
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Fully aromatic conjugated covalent organic frameworks (FAC-COFs) with excellent physicochemical stability have been emerging as active semiconductors for diverse potential applications. Developing efficient synthesis methods for fabricating FAC-COFs will significantly facilitate the exploration over their material and photonic/electronic functionalities. Herein, a facile solvent-free strategy is developed for the synthesis of 2D phthalocyanine-based FAC-COFs (FAC-Pc-COFs). Cyclopolymerization of benzo[1,2-b:4,5-b']bis[1,4]benzodioxin-2,3,9,10-tetracarbonitrile (BBTC) and quinoxalino[2',3':9,10]phenanthro[4,5-abc]phenazine-6,7,15,16-tetracarbonitrile (QPPTC) in ZnCl2 leads to the fast formation and isolation of BB-FAC-Pc-COF and QPP-FAC-Pc-COF, respectively. Powder X-ray diffraction and electron microscopy analysis reveal their crystalline nature with sql topology and AA stacking configuration. Thermogravimetric analysis and immersion experiment indicate their excellent stability. The conductivity test demonstrates their high conductivity of 0.93-1.94 × 10-4 S cm-1 owing to the fully π-conjugated electronic structural nature. In particular, the as-prepared FAC-Pc-COFs show high-performance K+ storage in potassium-ion batteries due to their excellent conductivity, highly ordered and robust structure, and N/O-rich framework nature. Impressively, QPP-FAC-Pc-COF shows a large reversible capacity of 424 mA h g-1 after 100 cycles at 50 mA g-1 and a capacity retention of nearly 100% at 2000 mA g-1 for over 10 000 cycles.
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Nutritional correlations between plants and pathogens can crucially affect disease severity. As an essential macronutrient, the availability of nitrogen (N) and the types of N content play a fundamental part not only in energy metabolism and protein synthesis but also in pathogenesis. However, a direct connection has not yet been established between differences in the level of resistance and N metabolism. Pertinently, former studies hold ammonia (NH3) accountable for the development of diseases in tobacco (Nicotiana tabacum L.) and in some post-harvest fruits. With a purpose of pinpointing the function of NH3 volatilization on Alternaria alternata (Fries) Keissl pathogenesis and its correlation with both N metabolism and resistance differences to Alternaria alternata infection in tobacco, leaf tissue of two tobacco cultivars with susceptibility (Changbohuang; CBH), or resistance (Jingyehuang; JYH) were analyzed apropos of ammonia compensation point, apoplastic NH4 + concentration, pH value as well as activities of key enzymes and N status. At the leaf age of 40 to 60 d, the susceptible cultivar had a significantly higher foliar apoplastic ammonium (NH4 +) concentration, pH value and NH3 volatilization potential compared to the resistant one accompanied by a significant reduction in glutamine synthetase (GS), which in particular was a primary factor causing the NH3 volatilization. The NH4 + concentration in CBH was 1.44 times higher than that in JYH, and CBH had NH3 compensation points that were 7.09, 6.15 and 4.35-fold higher than those of JYH at 40, 50 and 60 d, respectively. Moreover, the glutamate dehydrogenase (GDH) activity had an upward tendency related to an increased NH4 + accumulation in both leaf tissues and apoplast but not with the NH3 compensation point. Collectively, our results strongly suggest that the accumulation of NH3 volatilization, rather than NH4 + and total N, was the primary factor inducing the Alternaria alternata infection in tobacco. Meanwhile, the susceptible cultivar was characterized by a higher N re-transfer ability of NH3 volatilization, in contrast to the disease-resistant cultivar, and had a stronger capability of N assimilation and reutilization. This study provides a deeper understanding of the pathogenicity mechanism induced by Alternaria alternata, which is useful for breeding Alternaria alternata-resistant varieties of tobacco, at the same time, our research is also conducive to control tobacco brown spot caused by Alternaria alternata in the field.
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For preparing high-performance electrospun fibers with functional molecules that cannot cross-entangle themselves, such as conductive polymers, promoting the aggregation of functional molecules on the surface by surface segregation is a promising approach. In the present study, electrospun polymethyl methacrylate/polyaniline (PMMA/PANI) fibers were prepared under various conditions, including solution composition, applied voltage, tip-to-collector distance, temperature, humidity, and gas-phase solvent concentration, to examine the effects of the parameters on fiber morphology and surface segregation. The changes in fiber morphology and variations in the intensity of PANI and PMMA's characteristic bands were investigated with scanning electron microscopy (SEM) and Raman spectroscopy. The results demonstrated that by changing the saturation difference and the viscosity, the amount of PMMA and PANI added significantly influenced whether surface segregation could occur. The effect of other investigated parameters on surface segregation was concluded to alter the molecular migratable time by affecting the jet flight time and the solvent volatilization rate. Among them, increasing the solvent concentration could significantly promote surface segregation without sacrificing morphological advantages. When the solvent concentration increased from 1.4 to 158 mg/m3, the Raman peak intensity ratio of PANI and PMMA increased from 2.91 to 5.05, while the fiber diameter remained essentially constant.
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Indoor decoration causes a large amount of formaldehyde to be concurrently released from different surfaces of wood-based panels. However, this phenomenon has rarely been described with two- or three-dimensional mass transfer models. In this paper, multidimensional mass transfer models of formaldehyde emissions originating from different surfaces of building materials are first established. Moreover, mass balance integral equation is introduced. Experiments of formaldehyde emissions in the environmental chambers are numerically simulated by combining the parameter estimation method, composite Simpson formula and finite difference method, whose convergence and stability are verified. The results indicated that the proposed models suitably agreed with the experimental and literature data. Furthermore, the multidimensional mass transfer model confirmed that formaldehyde released from sides should not be ignored. Compared with the one-dimensional model, the three-dimensional model can more accurately simulate the release data of formaldehyde from wood-based panels. Subsequently, the variation trend between the chemical reaction formation rate and physical diffusion rate of formaldehyde is revealed.
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Formaldeído , Madeira , Materiais de Construção , DifusãoRESUMO
Interferons (IFNs) are divided into 3 types (type I, type II, and type III) on the basis of sequence homology and functional properties. Recombinant IFNs have been approved by regulatory agencies in many countries for clinical treatment of hepatitis B, hepatitis C, and other diseases; these IFNs are mainly produced in microorganisms and mammalian cell systems. However, there are serious obstacles to the production of recombinant IFNs in microorganism systems; for example, the recombinant IFN may have different glycosylation patterns from the native protein, be present in insoluble inclusion bodies, be contaminated with impurities such as endotoxins and nucleic acids, have a short half-life in human blood, and incur high production costs. Some medicinal proteins have been successfully expressed in plants and used in clinical applications, suggesting that plants may also be a good system for IFN expression. However, there are still many technical problems that need to be addressed before the clinical application of plant-expressed IFNs, such as increasing the amount of recombinant protein expression and ensuring that the IFN is modified with the correct type of glycosylation. In this article, we review the classification of IFNs, their roles in antiviral signal transduction pathways, their clinical applications, and their expression in plant systems.
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Hepatite C , Interferon Tipo I , Animais , Antivirais , Hepacivirus , Humanos , Fatores Imunológicos , Interferons , Mamíferos , Transdução de SinaisRESUMO
As one of the major sources of volatile pollutants in indoor air, gaseous emissions from adhesives during interior decoration have attracted increasing concern. Identifying major volatile pollutants and the risk in adhesive gaseous emissions is of great significance, but remains rarely reported. In the present research, we assessed the major volatile pollutants emitted from white emulsion adhesive and silicone adhesive samples (n = 30) from three aspects: chemical composition, odor and health risk contributions. The results showed that a total of 21 volatile pollutants were detected. Significantly, xylene was the most concentrated compound from white emulsion adhesives, accounting for 45.51% of the total concentrations. Butanone oxime was the most concentrated compound in silicone adhesives, accounting for 69.86% of the total concentrations. The trends in odor concentration (evaluated by the odor activity value method) over time were well correlated with the total chemical concentrations. Xylene (58.00%) and butanone oxime (76.75%) showed the highest odor contribution, respectively. Moreover, from an integrated perspective of chemical emissions, odor and health risk contributions, xylene, ethylbenzene, ethyl acetate and benzene were identified as the key volatile pollutants emitted from the white emulsion adhesives, while butanone oxime, butanone, and ethanol were the key volatile pollutants emitted from the silicone adhesives. This study not only identified the key volatile pollutants but also provided characteristics of odor and health risks of gas emitted from adhesives.
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Adesivos/química , Poluentes Atmosféricos/análise , Odorantes/análise , Compostos Orgânicos Voláteis/análise , Butanonas/análise , Monitoramento Ambiental , Humanos , Xilenos/análiseRESUMO
This study put forward a one-step carbonization method by concentrated sulfuric acid to prepare garlic peel derived biochar, and the synthetic conditions were optimized by L16(45) orthogonal experiments. Notably, in order to study the differences between the proposed synthetic method and the conventional pyrolysis method, the concentrated sulfuric acid carbonized garlic peels biochar (CSGPB) was compared with pyrolysis derived garlic peel biochar (HTGPB) in characterization and adsorption capacities for Enrofloxacin (ENR). Results showed that CSGPB exhibited more graphite-like structures with more active functional groups on the surface, and the equilibrium adsorption capacity of CSGPB (142.3 mg g-1) was 13.7 times of HTGPB (10.4 mg g-1) under identical conditions. Moreover, the adsorption behaviors including adsorption kinetics, isotherms and thermodynamics of CSGPB for ENR were fully investigated and discussed. Based on the above experiments, density functional theory (DFT) simulations were performed to reveal the interfacial interaction and adsorption mechanism. Results showed π-π interaction between quinolone moieties of ENR and graphite-like structures in CSGPB might be the dominant mechanism. As for the functional groups, the adsorption energies were -40.46, -15.21 and -5.96 kJ mol-1 for -SO3H, -OH and -COOH, respectively, which indicated -SO3H was the most active functional groups on the surface of CSGPB. This study provided a new sustainable perspective for the design of efficient biochars, and explored the interfacial interaction mechanism of antibiotics removal on biochars.
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Alho , Poluentes Químicos da Água , Adsorção , Carvão Vegetal , Enrofloxacina , Cinética , Ácidos Sulfúricos , Poluentes Químicos da Água/análiseRESUMO
Ozone air pollution has been increasingly severe and has become another major air pollutant in Chinese cities, while PM1 is more harmful to human health than coarser PMs. However, nationwide studies estimating the effects of ozone and PM1 are quite limited in China. This study aims to assess the spatial associations between ozone (and PM1) and the incidence rate of female lung cancer in 436 Chinese cancer registries (counties/districts). The effects of ozone and PM1 were estimated, respectively, using statistical models controlling for time, location and socioeconomic covariates. Then, three sensitivity analyses including the adjustments of smoking covariates and co-pollutant (SO2) and the estimates of ozone, PM1 and SO2 effects in the same model, were conducted to test the robustness of the effects of the two air pollutants. Further still, we investigated the modifying role of urban-rural division on the effects of ozone and PM1. According to the results, a 10 µg/m3 increase in ozone and PM1 was associated with a 4.57% (95% CI: 4.32%, 16.16%) and 4.89% (95% CI: 4.37%, 17.56%) increase in the incidence rate of female lung cancer relative to its mean, respectively. Such ozone and PM1 effects were still significant in three sensitivity analyses. Regarding the modifying role of urban-rural division, the effect of PM1 was greater by 2.98% (95% CI: 1.01%, 4.96%) in urban than in rural areas when PM1 changed by 10 µg/m3. However, there was no modification effect of urban-rural division for ozone. In conclusion, there were positive associations between ozone (and PM1) and the incidence rate of female lung cancer in China. Urban-rural division may modify the effect of PM1 on the incidence rate of female lung cancer, which is seldom reported. Continuous and further prevention and control measures should be developed to alleviate the situation of the two air pollutants.
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Poluentes Atmosféricos , Poluição do Ar , Neoplasias Pulmonares , Ozônio , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , China/epidemiologia , Exposição Ambiental/análise , Feminino , Humanos , Incidência , Neoplasias Pulmonares/induzido quimicamente , Neoplasias Pulmonares/epidemiologia , Ozônio/análise , Material Particulado/análise , Material Particulado/toxicidadeRESUMO
Volatile organic compounds (VOCs) emissions are regarded as a worth concerned threat to human health. The UV-Fenton coupled with mass transfer enhanced process shows promising effects on VOCs treatment. However, the detailed mechanism and mathematical model for this method have not been established. This work focuses on the hypothesis and validation of a mathematical model for UV-Fenton removal of VOCs using activated carbon particles to enhance mass transfer efficiency. Based on the mathematical model of reaction-diffusion-mass transfer, a mathematical model is established by using a series of important parameters such as ub, Dg, Dl, Kial, Kla and hydroxyl radical lifetime. The proposed model in this study introduces the key parameter of synergistic factor, which greatly improves the consistency between the model predicted results and the experimental data (the determination coefficient R2 distribution range changed from 0.71-0.98 to 0.95-0.98). Moreover, it can also explain reasonably the steady trend of outlet VOC concentration after 30 min of reaction. The mathematical model confirms that the addition of activated carbon during the UV-Fenton reaction ensures mass transfer efficiency and considerably improves (growth from 2% to 54%) the VOCs removal efficiency due to the synergy between UV-Fenton oxidation and mass transfer enhancement. Meanwhile, it provides insight into fruitful utilization of the oxidation capacity in the oxidation reaction,and achieves the purpose of predicting the efficiency of VOC removal in the Fenton process.