RESUMO
Ozonation is universally used during water treatment but can form hazardous brominated disinfection byproducts (Br-DBPs). While sunlight exposure is advised to reduce the risk of Br-DBPs, their phototransformation pathways remain insufficiently understood. Here, sunlight irradiation was found to reduce adsorbable organic bromine by 63%. Applying high-resolution mass spectrometry, the study investigated transformations of dissolved organic matter in sunlit-ozonated reclaimed water, revealing the number and abundance of assigned formulas decreased after irradiation. The Br-DBPs with O/C < 0.6 and MW > 400 Da were decreased or removed after irradiation, with the majority being CHOBr compounds. The peak intensity reduction ratio of CHOBr compounds correlated positively with double bound equivalent minus oxygen ratios but negatively with O/C, suggesting that photo-susceptible CHOBr compounds were highly unsaturated. Mass difference analysis revealed that the photodegradation pathways were mainly oxidation aligned with debromination. Three typical CHOBr molecular structures were resolved, and their photoproducts were proposed. Toxicity estimates indicated decreased toxicity in these photoproducts compared to their parent compounds, in line with experimentally determined values. Our proposed phototransformation pathways for Br-DBPs enhance our comprehension of their degradation and irradiation-induced toxicity reduction in reclaimed water, further illuminating their transformation under sunlight in widespread environmental scenarios.
Assuntos
Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Desinfecção/métodos , Desinfetantes/análise , Desinfetantes/química , Desinfetantes/toxicidade , Halogenação , Poluentes Químicos da Água/análise , Purificação da Água/métodosRESUMO
Many studies have investigated activation of ferrate (Fe(VI)) to produce reactive high-valent iron intermediates to enhance the oxidation of micropollutants. However, the differences in the risk of pollutant transformation caused by Fe(IV) and Fe(V) have not been taken seriously. In this study, Fe(VI)-alone, Fe3+/Fe(VI), and NaHCO3/Fe(VI) processes were used to oxidize fluoroquinolone antibiotics to explore the different effects of Fe(IV) and Fe(V) on product accumulation and toxicity changes. The contribution of Fe(IV) to levofloxacin degradation was 99.9% in the Fe3+/Fe(VI) process, and that of Fe(V) was 89.4% in the NaHCO3/Fe(VI) process. The cytotoxicity equivalents of levofloxacin decreased by 1.9 mg phenol/L in the Fe(IV)-dominant process while they significantly (p < 0.05) increased by 4.7 mg phenol/L in the Fe(V)-dominant process. The acute toxicity toward luminescent bacteria and the results for other fluoroquinolone antibiotics also showed that Fe(IV) reduced the toxicity and Fe(V) increased the toxicity. Density functional theory calculations showed that Fe(V) induced quinolone ring opening, which would increase the toxicity. Fe(IV) tended to oxidize the piperazine group, which reduced the toxicity. These results show the different-pollutant transformation caused by Fe(IV) and Fe(V). In future, the different risk outcomes during Fe(VI) activation should be taken seriously.
Assuntos
Poluentes Ambientais , Poluentes Químicos da Água , Purificação da Água , Fluoroquinolonas/toxicidade , Levofloxacino , Ferro , Oxirredução , Fenóis , Antibacterianos/toxicidade , Purificação da Água/métodosRESUMO
Brominated byproducts and toxicity generation are critical issues for ozone application to wastewater containing bromide. This study demonstrated that ultraviolet/ozone (UV/O3, 100 mJ/cm2, 1 mg-O3/mg-DOC) reduced the cytotoxicity of wastewater from 14.2 mg of pentol/L produced by ozonation to 4.3 mg of pentol/L (1 mg/L bromide, pH 7.0). The genotoxicity was also reduced from 1.65 to 0.17 µg-4-NQO/L by UV/O3. Compared with that of O3 alone, adsorbable organic bromine was reduced from 25.8 to 5.3 µg/L by UV/O3, but bromate increased from 32.9 to 71.4 µg/L. The UV/O3 process enhanced the removal of pre-existing precursors (highly unsaturated and phenolic compounds and poly aromatic hydrocarbons), while new precursors were generated, yet the combined effect of UV/O3 on precursors did not result in a significant change in toxicity. Instead, UV radiation inhibited HOBr concentration through both rapid O3 decomposition to reduce HOBr production and decomposition of the formed HOBr, thus suppressing the AOBr formation. However, the hydroxyl radical-dominated pathway in UV/O3 led to a significant increase of bromate. Considering both organic bromine and bromate, the UV/O3 process effectively controlled both cytotoxicity and genotoxicity of wastewater to mammalian cells, even though an emphasis should be also placed on managing elevated bromate. Futhermore, other end points are needed to evaluate the toxicity outcomes of the UV/O3 process.
Assuntos
Bromo , Águas Residuárias , Bromo/química , Bromo/toxicidade , Bromatos/química , Processos Fotoquímicos , Raios Ultravioleta , Ozônio/química , Purificação da Água/métodos , Águas Residuárias/toxicidade , Mamíferos , Animais , Células CHO , CricetulusRESUMO
BACKGROUND: Alzheimer's disease (AD) is the leading cause of dementia, resulting in impairments in memory, cognition, decision-making, and social skills. Thus, accurate preclinical diagnosis of Alzheimer's disease is paramount. The identification of biomarkers for Alzheimer's disease through magnetic resonance spectroscopy (MRS) represents a novel adjunctive diagnostic approach. OBJECTIVE: This study conducted a meta-analysis of the diagnostic results of this technology to explore its feasibility and accuracy. METHODS: PubMed, Cochrane Library, EMBASE, and Web of Science databases were searched without restrictions, with the search period extending up to July 31, 2022. The search strategy employed a combination of subject headings and keywords. All retrieved documents underwent screening by two researchers, who selected them for meta-analysis. The included literature was analyzed using Review Manager 5.4 software, with corresponding bias maps, forest plots, and summary receiver operating characteristic (SROC) curves generated and analyzed. RESULTS: A total of 344 articles were retrieved initially, with 11 articles meeting the criteria for inclusion in the analysis. The analysis encompassed data from approximately 1766 patients. In the forest plot, both sensitivity (95% CI) and specificity (95% CI) approached 1. Examining the true positive rate, false positive rate, true negative rate, and false negative rate, all studies on the summary receiver operating characteristic (SROC) curve clustered in the upper left quadrant, suggesting a very high accuracy of biomarkers detected by MRS for diagnosing Alzheimer's disease. CONCLUSION: The detection of biomarkers by MRS demonstrates feasibility and high accuracy in diagnosing AD. This technology holds promise for widespread adoption in the clinical diagnosis of AD in the future.
Assuntos
Doença de Alzheimer , Biomarcadores , Estudos de Viabilidade , Espectroscopia de Ressonância Magnética , Doença de Alzheimer/diagnóstico , Doença de Alzheimer/diagnóstico por imagem , Humanos , Biomarcadores/análise , Espectroscopia de Ressonância Magnética/métodos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: Clear cell renal cell carcinoma (ccRCC) is a malignant tumor with heterogeneous morphology and poor prognosis. This study aimed to establish a DNA methylation (DNAm)-driven gene-based prognostic model for ccRCC. METHODS: Reduced representation bisulfite sequencing (RRBS) was performed on the DNA extracts from ccRCC patients. We analyzed the RRBS data from 10 pairs of patient samples to screen the candidate CpG sites, then trained and validated an 18-CpG site model, and integrated the clinical characters to establish a Nomogram model for the prognosis or risk evaluation of ccRCC. RESULTS: We identified 2261 DMRs in the promoter region. After DMR selection, 578 candidates were screened, and was correspondence with 408 CpG dinucleotides in the 450 K array. We collected the DNAm profiles of 478 ccRCC samples from TCGA dataset. Using the training set with 319 samples, a prognostic panel of 18 CpGs was determined by univariate Cox regression, LASSO regression, and multivariate Cox proportional hazards regression analyses. We constructed a prognostic model by combining the clinical signatures. In the test set (159 samples) and whole set (478 samples), the Kaplan-Meier plot showed significant differences; and the ROC curve and survival analyses showed AUC greater than 0.7. The Nomogram integrated with clinicopathological characters and methylation risk score had better performance, and the decision curve analyses also showed a beneficial effect. CONCLUSIONS: This work provides insight into the role of hypermethylation in ccRCC. The targets identified might serve as biomarkers for early ccRCC diagnosis and prognosis biomarkers for ccRCC. We believe our findings have implications for better risk stratification and personalized management of this disease.
Assuntos
Carcinoma de Células Renais , Neoplasias Renais , Humanos , Carcinoma de Células Renais/patologia , Prognóstico , Metilação de DNA , Neoplasias Renais/patologia , Biomarcadores Tumorais/genética , Biomarcadores Tumorais/metabolismoRESUMO
OBJECTIVE: Both stent grafts (SG) and drug-coated balloons (DCBs) have shown to be effective treatments for long and complex femoropopliteal (FP) lesions. However, there has not been a clinical trial comparing the 2 treatments directly. This study aims to compare the primary patency (PP) and clinical outcomes of SG and DCB for endovascular treatment of complex FP Trans-Atlantic Inter-Society Consensus (TASC) C/D lesions in patients. METHODS: From July 2013 to May 2019, a retrospective study was conducted at 2 medical centers to compare the clinical outcomes of Viabahn SG and DCB angioplasty in patients with TASC C/D FP lesions. The study used overlap weighting to adjust for differences in baseline characteristics and to reduce the impact of confounding factors and selection bias between the 2 groups. The primary endpoint was PP through 24 months, and the secondary endpoints included freedom from clinical-driven target lesion revascularization (CD-TLR), all-cause of death rate, and major amputation rate. RESULTS: A total of 161 limbs in 150 patients with TASC C/D FP lesions were treated either with Viabahn SGs (67 limbs, 65 patients) or DCBs (94 limbs, 85 patients). In the DCB group, 22 target vessels (23.4%) underwent directional atherectomy before DCB angioplasty and 37 target vessels (39.4%) underwent bail-out bare-metal stent implantation for early recoil or severe dissection. The SG group had significantly higher PP rates at both the 12 and 24 months than in the DCB group (75.8% vs 39.2%, p=0.02; 64.1% vs 31.9%, p=0.02), respectively. However, there were no significant differences between the 2 groups in terms of CD-TLR, death rate, and major amputation rate. According to the results of multivariate analysis, DCB angioplasty was the only independent predictor associated with restenosis (hazard ratio [HR]=0.264, 95% confidence interval [CI]=0.100-0.696, p=0.007). CONCLUSIONS: This study showed that SG was associated with a significantly higher PP rate in complex long FP lesions compared with DCB angioplasty. However, there was no significant difference in the freedom from CD-TLR and major amputation rate. It is important to follow the criteria for using SG strictly to avoid early restenosis, which can lead to acute thrombosis and severe limb ischemia. Closer monitoring is recommended for patients who undergo SG implantation. CLINICAL IMPACT: There has no head-to-head clinical trial that compares DCB and SG in complex long FP lesions. This study showed that SG following the criteria was associated with a significantly higher PP rate compared with DCB angioplasty. Closer monitoring is recommended for patients with SG to avoid acute thrombosis. Randomized controlled trials comparing SG and DCB are necessary.
RESUMO
Byproduct formation (chlorate, bromate, organic halogen, etc.) during sulfate radical (SO4â¢-)-based processes like ultraviolet/peroxymonosulfate (UV/PMS) has aroused widespread concern. However, hypohalous acid (HOCl and HOBr) can form via two-electron transfer directly from PMS, thus leading to the formation of organic halogenated byproducts as well. This study found both PMS alone and UV/PMS can increase the toxicity to mammalian cells of wastewater, while the UV/H2O2 decreased the toxicity. Cytotoxicity of two wastewater samples increased from 5.6-8.3 to 15.7-29.9 mg-phenol/L, and genotoxicity increased from 2.8-3.1 to 5.8-12.8 µg 4-NQO/L after PMS treatment because of organic halogen formation. Organic halogen formation from bromide rather than chloride was found to dominate the toxicity increase. The SO4â¢--based process UV/PMS led to the formation of both organic halogen and inorganic bromate and chlorate. However, because of the very low concentration (<20 µg/L) and relatively low toxicity of bromate and chlorate, contributions of inorganic byproducts to toxicity increase were negligible. PMS would not form chlorate and bromate, but it generated a higher concentration of total organic halogen, thus leading to a more toxic treated wastewater than UV/PMS. UV/PMS formed less organic halogen and toxicity because of the destruction of byproducts by UV irradiation and the removal of byproduct precursors. Currently, many studies focused on the byproducts bromate and chlorate during SO4â¢--based oxidation processes. This work revealed that the oxidant PMS even needs more attention because it caused higher toxicity due to more organic halogen formation.
Assuntos
Poluentes Químicos da Água , Purificação da Água , Animais , Oxidantes , Peróxido de Hidrogênio , Bromatos/toxicidade , Águas Residuárias , Cloratos , Poluentes Químicos da Água/análise , Peróxidos , Oxirredução , Halogênios , MamíferosRESUMO
Oxyanions, a class of constituents naturally occurring in water, have been widely demonstrated to enhance permanganate (Mn(VII)) decontamination efficiency. However, the detailed mechanism remains ambiguous, mainly because the role of oxyanions in regulating the structural parameters of colloidal MnO2 to control the autocatalytic activity of Mn(VII) has received little attention. Herein, the origin of oxyanion-induced enhancement is systematically studied using theoretical calculations, electrochemical tests, and structure-activity relation analysis. Using bicarbonate (HCO3-) as an example, the results indicate that HCO3- can accelerate the degradation of phenol by Mn(VII) by improving its autocatalytic process. Specifically, HCO3- plays a significant role in regulating the structure of in situ produced MnO2 colloids, i.e., increasing the surface Mn(III)s content and restricting particle growth. These structural changes in MnO2 facilitate its strong binding to Mn(VII), thereby triggering interfacial electron transfer. The resultant surface-activated Mn(VII)* complexes demonstrate excellent degrading activity via directly seizing one electron from phenol. Further, other oxyanions with appropriate ionic potentials (i.e., borate, acetate, metasilicate, molybdate, and phosphate) exhibit favorable influences on the oxidative capability of Mn(VII) through an activation mechanism similar to that of HCO3-. These findings considerably improve our fundamental understanding of the oxidation behavior of Mn(VII) in actual water environments and provide a theoretical foundation for designing autocatalytically boosted Mn(VII) oxidation systems.
Assuntos
Compostos de Manganês , Óxidos , Óxidos/química , Compostos de Manganês/química , Fenol , Fenóis , Oxirredução , ÁguaRESUMO
Precisely identifying the atomic structures in single-atom sites and establishing authentic structure-activity relationships for single-atom catalyst (SAC) coordination are significant challenges. Here, theoretical calculations first predicted the underlying catalytic activity of Fe-NxC4-x sites with diverse first-shell coordination environments. Substituting N with C to coordinate with the central Fe atom induces an inferior Fenton-like catalytic efficiency. Then, Fe-SACs carrying three configurations (Fe-N2C2, Fe-N3C1, and Fe-N4) fabricate facilely and demonstrate that optimized coordination environments of Fe-NxC4-x significantly promote the Fenton-like catalytic activity. Specifically, the reaction rate constant increases from 0.064 to 0.318 min-1 as the coordination number of Fe-N increases from 2 to 4, slightly influencing the nonradical reaction mechanism dominated by 1O2. In-depth theoretical calculations unveil that the modulated coordination environments of Fe-SACs from Fe-N2C2 to Fe-N4 optimize the d-band electronic structures and regulate the binding strength of peroxymonosulfate on Fe-NxC4-x sites, resulting in a reduced energy barrier and enhanced Fenton-like catalytic activity. The catalytic stability and the actual hospital sewage treatment capacity also showed strong coordination dependency. This strategy of local coordination engineering offers a vivid example of modulating SACs with well-regulated coordination environments, ultimately maximizing their catalytic efficiency.
Assuntos
Eletrônica , Hospitais , Catálise , Ferro , EsgotosRESUMO
Sulfur is essential for plant growth, and the uptake of sulfate by plant roots is the primary source of plant sulfur. Previous studies have shown that the OAS-TL gene is a key enzyme in the sulfur metabolic pathway and regulates cysteine (Cys) synthase production. However, the interaction mechanism of the glycine max OAS-TL3 Cys synthase (OAS-TL3) gene on soybean root morphology construction and seed protein accumulation is unclear. This study shows that mutant M18 has better root growth and development, higher seed protein content, and higher methionine (Met) content in sulfur-containing amino acids than wild-type JN18. By transcriptome sequencing, the differentially expressed OAS-TL3 gene was targeted in the mutant M18 root line. The relative expression of the OAS-TL3 gene in roots, stems, and leaves during the seedling, flowering, and bulking stages of the OAS-TL3 gene overexpression lines is higher than that of the recipient material. Compared to the recipient material JN74, the enzymatic activities, Cys, and GSH contents of OAS-TL are higher in the sulfur metabolic pathway of seedling roots. The receptor material JN74 is exogenously applied with different concentrations of reduced glutathione. The results demonstrate a positive correlation between reduced glutathione on total root length, projected area, surface area, root volume, total root tip number, total bifurcation number, and total crossing number. The Met and total protein contents of sulfur-containing amino acids in soybean seeds of the OAS-TL3 gene overexpression lines are higher than those of the recipient material JN74, while the gene-edited lines show the opposite results. In conclusion, the OAS-TL3 gene positively regulates soybean root growth, root activity, and the content of Met in the seeds through the OAS-TL-Cys-GSH pathway. It breaks the limitation of other amino acids and facilitates the increase of total seed protein content. Supplementary Information: The online version contains supplementary material available at 10.1007/s11032-022-01348-y.
RESUMO
The mechanism by which antibiotics in swine wastewater affect anaerobic digestion (AD) remains unclear. Herein, we investigated how single and mixed antibiotics affect AD in swine wastewater. Both single and mixed antibiotics stimulated methane production at actual concentrations of 0.5-2 mg/L. Low-dose antibiotics (0.5 mg/L) exerted the most significant stimulatory effect on methane production, which increased by 211.63% (single) and 60.93% (mixed), respectively. However, an increased dose decreased the stimulatory effect on methane production. Overall, single antibiotics were more beneficial for methane production than mixed antibiotics since single antibiotics could promote the conversion of propionic and butyric acid, while mixed antibiotics inhibited the process. Microbial community analysis showed that single and mixed antibiotics could also lead to large changes in functional acidogens, ultimately leading to changes in methanogenic pathways.
Assuntos
Antibacterianos , Águas Residuárias , Animais , Suínos , Antibacterianos/farmacologia , Anaerobiose , Metano , Perfilação da Expressão Gênica , Reatores Biológicos , EsgotosRESUMO
Marine octocorals belonging to the genus Cladiella, usually encountered on reefs in the Indo-Pacific region, have been proven to be rich sources of diverse secondary metabolites with intriguing structural features and promising bioactivities. In this review, 155 compounds from six unambiguously identified C. krempfi, C. australis, C. pachyclados, C. hirsuta, C. tuberculosa, C. conifera, together with several unidentified Cladiella spp. are summarized covering the literatures from 2006 to August 2022. It is noteworthy that diterpenoids dominated the secondary metabolite profile of this genus counting for 78 %. Structurally, the majority of these diterpenes belonged to eunicellan family characterized by different patterns of ether linkage. The impacts of these chemical compositions on an array of potential pharmacological activities were also reviewed, giving an overview of the potential application of Cladiella secondary metabolites.
Assuntos
Antozoários , Diterpenos , Animais , Anti-Inflamatórios/farmacologia , Diterpenos/farmacologia , Diterpenos/química , Antozoários/químicaRESUMO
Objective: To explore the status quo and influencing factors of feeding behaviors of micronutrient powders (MNP), or yingyangbao in Pinyin, the Chinese Romanization system, of baby caregivers in remote rural areas of Sichuan Province. Methods: In 2019, caregivers of babies aged 6 to 24 months from 6 counties of Sichuan Province were selected as the respondents of the survey through a multistage cluster random sampling method. Data concerning the baby caregivers' attitude of behavior, subjective norms, behavioral intention, and feeding behaviors about MNP feeding were collected with a questionnaire through a structured interview. Based on the theory of reasoned action, a structural equation model was constructed to explore the influencing factors of feeding behaviors. Results: A total of 1002 valid samples were included in the study. The effective feeding rate of MNP among the baby caregivers was 55.49%. The results of model analysis suggested that attitude of behavior ( ß direct=0.212, 95% CI: 0.105-0.327), subjective norm ( ß direct=0.123, 95% CI: 0.016-0.228), and behavioral intention ( ß direct=0.162, 95% CI: 0.093-0.224) could have a significant direct impact on MNP feeding behaviors. Behavior attitude ( ß indirect=0.044, 95% CI: 0.023-0.073) and subjective norms ( ß indirect=0.018, 95% CI: 0.001-0.040) could have a significant indirect impact on MNP feeding behaviors through the intermediary of behavioral intention. Among the three theoretical elements, attitude of behavior had the largest total effect on the feeding behavior ( ß total=0.256, 95% CI: 0.148-0.366). Conclusion: The effective feeding rate of MNP among baby caregivers in remote rural areas of Sichuan Province is low. The attitude of behavior and subjective norms of caregivers may have a direct impact on their feeding behavior, and both attitude of behavior and subjective norms can have an indirect impact on the feeding behavior through the intermediary of behavioral intention. The influence of attitude of behavior attitude on feeding behavior is greater than that of subjective norms. Future intervention plans for promoting effective MNP feeding should incorporate health education for baby caregivers and their important social relations. Thus, baby caregivers' attitude and willingness for MNP feeding will be strengthened and the effective feeding rate of MNP will be improved accordingly.
Assuntos
Cuidadores , Micronutrientes , Lactente , Humanos , Pós , Teoria do Comportamento Planejado , Comportamento Alimentar , ChinaRESUMO
Chiral ferroelectric crystals with intriguing features have attracted great interest and many with point or axial chirality based on the stereocarbon have been successively developed in recent years. However, ferroelectric crystals with stereogenic heteroatomic chirality have never been documented so far. Here, we discover and report a pair of enantiomeric stereogenic sulfur-chiral single-component organic ferroelectric crystals, Rs -tert-butanesulfinamide (Rs -tBuSA) and Ss -tert-butanesulfinamide (Ss -tBuSA) through the deep understanding of the chemical design of molecular ferroelectric crystals. Both enantiomers adopt chiral-polar point group 2 (C2 ) and exhibit mirror-image relationships. They undergo high-temperature 432F2-type plastic ferroelectric phase transition around 348â K. The ferroelectricity has been well confirmed by ferroelectric hysteresis loops and domains. Polarized light microscopy records the evolution of the ferroelastic domains, according with the fact that the 432F2-type phase transition is both ferroelectric and ferroelastic. The very soft characteristics with low elastic modulus and hardness reveals their excellent mechanical flexibility. This finding indicates the first stereosulfur chiral molecular ferroelectric crystals, opening up new fertile ground for exploring molecular ferroelectric crystals with great application prospects.
RESUMO
Thermally triggered spatial symmetry breaking in traditional ferroelectrics has been extensively studied for manipulation of the ferroelectricity. However, photoinduced molecular orbital breaking, which is promising for optical control of ferroelectric polarization, has been rarely explored. Herein, for the first time, we synthesized a homochiral fulgide organic ferroelectric crystal (E)-(R)-3-methyl-3-cyclohexylidene-4-(diphenylmethylene)dihydro-2,5-furandione (1), which exhibits both ferroelectricity and photoisomerization. Significantly, 1 shows a photoinduced reversible change in its molecular orbitals from the 3â π molecular orbitals in the open-ring isomer to 2â π and 1â σ molecular orbitals in the closed-ring isomer, which enables reversible ferroelectric domain switching by optical manipulation. To our knowledge, this is the first report revealing the manipulation of ferroelectric polarization in homochiral ferroelectric crystal by photoinduced breaking of molecular orbitals. This finding sheds light on the exploration of molecular orbital breaking in ferroelectrics for optical manipulation of ferroelectricity.
RESUMO
In this study, the previously overlooked effects of contaminants' molecular structure on their degradation efficiencies and dominant reactive oxygen species (ROS) in advanced oxidation processes (AOPs) are investigated with a peroxymonosulfate (PMS) activation system selected as the typical AOP system. Averagely, degradation efficiencies of 19 contaminants are discrepant in the CoCaAl-LDO/PMS system with production of SO4â¢-, â¢OH, and 1O2. Density functional theory calculations indicated that compounds with high EHOMO, low-energy gap (ΔE = ELUMO - EHOMO), and low vertical ionization potential are more vulnerable to be attacked. Further analysis disclosed that the dominant ROS was the same one when treating similar types of contaminants, namely SO4â¢-, 1O2, 1O2, and â¢OH for the degradation of CBZ-like compounds, SAs, bisphenol, and triazine compounds, respectively. This phenomenon may be caused by the contaminants' structures especially the commonly shared or basic parent structures which can affect their effective reaction time and second-order rate constants with ROS, thus influencing the contribution of each ROS during its degradation. Overall, the new insights gained in this study provide a basis for designing more effective AOPs to improve their practical application in wastewater treatment.
Assuntos
Poluentes Químicos da Água , Purificação da Água , Estrutura Molecular , Oxirredução , Peróxidos/química , Espécies Reativas de Oxigênio , Poluentes Químicos da Água/químicaRESUMO
Conventional water disinfection methods such as chlorination typically involve the generation of harmful disinfection byproducts and intensive chemical consumption. Emerging electroporation disinfection techniques using nanowire-enhanced local electric fields inactivate microbes by damaging their outer structures without byproduct formation or chemical dosing. However, this physical-based method suffers from a limited inactivation efficiency under high water flux due to an insufficient contact time. Herein, we integrate electrochlorination with nanowire-enhanced electroporation to achieve a synergistic flow-through process for efficient water disinfection targeting bacteria and viruses. Electroporation at the cathode induces sub-lethal damages on the microbial outer structures. Subsequently, electrogenerated active chlorine at the anode aggravates these electroporation-induced injuries to the level of lethal damage. This sequential flow-through disinfection system achieves complete disinfection (>6.0-log) under a very high water flux of 2.4 × 104 L/(m2 h) with an applied voltage of 2.0 V. This disinfection efficiency is 8 times faster than that of electroporation alone. Further, the specific energy consumption for the disinfection by this novel process is extremely low (8 × 10-4 kW h/m3). Our results demonstrate a promising method for rapid and energy-efficient water disinfection by coupling electroporation with electrochlorination to meet vital needs for pathogen elimination.
Assuntos
Nanofios , Purificação da Água , Cloro/química , Desinfecção , Eletroporação , Nanofios/química , Água , Purificação da Água/métodosRESUMO
In order to study the role of GmXTH1 gene in alleviating drought stress, soybean seeds with GmXTH1 gene were transferred by T4 treated with PEG6000 concentration of 0%, 5%, 10%, and 15% respectively. The germination potential, germination rate, germination index, and other indicators were measured. The results showed that the germination potential, germination rate, and germination index of OEA1 and OEA2 strains overexpressed in T4 generation were significantly higher than those of the control material M18. After 0-day, 7-day, and 15-day drought stress, the analysis of seedling phenotypes and root-shoot of different T4 generation transgenic soybean lines showed that under stress conditions, the growth of GmXTH1 overexpression material was generally better than that of the control material M18. The growth of GmXTH1 interference expression material was generally worse than that of the control material M18, with significant differences in plant phenotypes. The root system of GmXTH1 overexpressed material was significantly developed compared with that of the control material M18. The analysis of physiological and biochemical indexes showed that the relative water content and the activity of antioxidant enzymes (superoxide dismutase and peroxidase) of GmXTH1 transgenic soybean material were significantly higher than those of the control material M18, and the accumulation of malondialdehyde was lower under the same stress conditions at seedling stage. Fluorescence quantitative PCR assay showed that the relative expression of GmXTH1 gene in transgenic soybean was significantly increased after drought stress. The results showed that the overexpression of GmXTH1 could increase the total root length, surface area, total projection area, root volume, average diameter, total cross number, and total root tip number, thereby increasing the water intake and reducing the transpiration of water content in leaves, thus reducing the accumulation of MDA and producing more protective enzymes in a more effective and prompt way, reducing cell membrane damage to improve drought resistance of soybean.
RESUMO
High concentration nitrogen-containing organic wastewater is a potential substrate for hydrogen production by dark fermentation. In this study, the effect of initial pH on the performance of hydrogen production by dark fermentation coupled denitrification was investigated. The hydrogen production, liquid metabolites, nitrate, nitrite and microbial community were monitored under the condition of pH varying from 4 to 11. Results showed that the highest hydrogen production (70.94 ± 4.750 mL/g VSS), chemical oxygen demand (COD) removal rate (37.13 ± 1.86%) and nitrate reduction rate (1.57 ± 0.27 mg/L/h) were obtained at pH of 5. Under this condition, the nitrate was mainly reduced to N2 with hydrogen as the electron donor. When the initial pH was 6-11, nitrate mainly reduced to N2 through co-action with acetate. Microbial community analysis revealed that as the initial pH increased from 4 to 11, the main hydrogen-producing microorganisms were gradually converted from Clostridium sensu stricto 12 sp. into Clostridium sensu stricto 1 sp, which leaded to changes in the hydrogen production process.
Assuntos
Desnitrificação , Hidrogênio , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Fermentação , Hidrogênio/química , Concentração de Íons de HidrogênioRESUMO
The first investigation of the South China Sea soft coral Sarcophyton boettgeri afforded five new capnosane diterpenes, sarboettgerins A-E (1-5), together with one known related compound, pavidolide D (6). Their structures, including absolute configurations, were elucidated by the extensive spectroscopic analysis, 13C NMR calculations, and X-ray diffraction. Among them, new compounds 1-5 were featured by the rarely encountered Z-geometry double bond Δ1 within the 5/11-fused bicyclic capnosane carbon framework. Plausible biogenetic relationships of all isolates were proposed, and they might give an insight into future biomimetic synthesis of these novel compounds. In an in vitro bioassay, compound 5 displayed potent anti-neuroinflammatory activity against LPS-induced NO release in BV-2 microglial cells, which might be developed as a new type of potential neuroprotective agent in future.