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1.
J Environ Manage ; 365: 121523, 2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38901321

RESUMO

Anaerobic oxidation of methane (AOM) is a microbial process of importance in the global carbon cycle. AOM is predominantly mediated by anaerobic methanotrophic archaea (ANME), the physiology of which is still poorly understood. Here we present a new addition to the current physiological understanding of ANME by examining, for the first time, the biochemical and redox-active properties of the extracellular polymeric substances (EPS) of an ANME enrichment culture. Using a 'Candidatus Methanoperedens nitroreducens'-dominated methanotrophic consortium as the representative, we found it can produce an EPS matrix featuring a high protein-to-polysaccharide ratio of ∼8. Characterization of EPS using FTIR revealed the dominance of protein-associated amide I and amide II bands in the EPS. XPS characterization revealed the functional group of C-(O/N) from proteins accounted for 63.7% of total carbon. Heme-reactive staining and spectroscopic characterization confirmed the distribution of c-type cytochromes in this protein-dominated EPS, which potentially enabled its electroactive characteristic. Redox-active c-type cytochromes in EPS mediated the EET of 'Ca. M. nitroreducens' for the reduction of Ag+ to metallic Ag, which was confirmed by both ex-situ experiments with extracted soluble EPS and in-situ experiments with pristine EPS matrix surrounding cells. The formation of nanoparticles in the EPS matrix during in-situ extracellular Ag + reduction resulted in a relatively lower intracellular Ag distribution fraction, beneficial for alleviating the Ag toxicity to cells. The results of this study provide the first biochemical information on EPS of anaerobic methanotrophic consortia and a new insight into its physiological role in AOM process.

2.
Opt Express ; 32(11): 18717-18726, 2024 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-38859021

RESUMO

A full C- and L-band covered second-order orbital-angular-momentum (OAM) mode generator has been proposed and experimentally demonstrated, which is realized by using a helical long-period fiber grating (HLPG) but inscribed in a thinned four-mode fiber. By optimizing the design of grating period and fiber diameter of the proposed HLPG, an ultra-broadband rejection filter with a depth of ∼23 dB, a bandwidth of ∼156 nm @-10 dB (ranging from 1522 nm to 1678 nm) and a bandwidth of ∼58 nm @-20 dB (ranging from 1574 nm to 1632 nm), has been successfully obtained as a typical sample. To the best of our knowledge, this is the first demonstration of such ultra-broadband second-order OAM mode generator by using only one fiber component, i.e., the thinned HLPG. In addition, the proposed generator is less polarization-dependent and less temperature-sensitive than those of the conventional HLPGs, which is believed to be considerably helpful to find potential applications of the device itself in wavelength division multiplexing (WDM) and OAM mode division multiplexing (MDM) optical fiber communication systems.

3.
Int J Surg ; 2024 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-38759695

RESUMO

BACKGROUND: Cancer-associated fibroblasts (CAFs) are found in primary and advanced tumours. They are primarily involved in tumour progression through complex mechanisms with other types of cells in the tumour microenvironment. However, essential fibroblasts-related genes (FRG) in bladder cancer still need to be explored, and there is a shortage of an ideal predictive model or molecular subtype for the progression and immune therapeutic assessment for bladder cancer, especially muscular-invasive bladder cancer based on the FRG. MATERIALS AND METHODS: CAF-related genes of bladder cancer were identified by analyzing single-cell RNA sequence datasets, and bulk transcriptome datasets and gene signatures were used to characterize them. Then, ten types of machine learning algorithms were utilized to determine the hallmark FRG and construct the FRG index (FRGI) and subtypes. Further molecular subtypes combined with CD8+ T-cells were established to predict the prognosis and immune therapy response. RESULTS: 54 BLCA-related FRG were screened by large-scale scRNA-sequence datasets. The machine learning algorithm established a 3-genes FRG index (FRGI). High FRGI represented a worse outcome. Then, FRGI combined clinical variables to construct a nomogram, which shows high predictive performance for the prognosis of bladder cancer. Furthermore, the BLCA datasets were separated into two subtypes - fibroblast hot and cold types. In five independent BLCA cohorts, the fibroblast hot type showed worse outcomes than the cold type. Multiple cancer-related hallmark pathways are distinctively enriched in these two types. In addition, high FRGI or fibroblast hot type shows a worse immune therapeutic response. Then, four subtypes called CD8-FRG subtypes were established under the combination of FRG signature and activity of CD8+ T-cells, which turned out to be effective in predicting the prognosis and immune therapeutic response of bladder cancer in multiple independent datasets. Pathway enrichment analysis, multiple gene signatures, and epigenetic alteration characterize the CD8-FRG subtypes and provide a potential combination strategy method against bladder cancer. CONCLUSIONS: In summary, we established a novel FRGI and CD8-FRG subtype by large-scale datasets and organized analyses, which could accurately predict clinical outcomes and immune therapeutic response of BLCA after surgery.

4.
Opt Express ; 32(3): 3046-3061, 2024 Jan 29.
Artigo em Inglês | MEDLINE | ID: mdl-38297536

RESUMO

What we believe to be a novel low-cost broadband continuous-wave water vapor differential absorption lidar (CW-DIAL) technique has been proposed and implemented by combing the Scheimpflug principle and the differential absorption method. The broadband CW-DIAL technique utilizes an 830-nm high-power multimode laser diode with 3-W output power as a tunable light source and a CMOS image sensor tilted at 45° as the detector. A retrieval algorithm dedicated for the broadband CW-DIAL technique has been developed to obtain range-resolved water vapor concentration from the DIAL signal. Atmospheric remote sensing of water vapor has been carried out on a near-horizontal water vapor path to validate the performance of the broadband CW-DIAL system. The retrieved water vapor concentration showed a good consistency with those measured by an air quality monitoring station, with a correlation coefficient of 0.9669. The fitting error of the water vapor concentration is found to be less than 10%. Numerical simulation studies have revealed that the aerosol-induced error on the water vapor concentration is below 5% with a background water vapor concentration of 5 g/m3 for most atmospheric conditions. The experimental results have successfully demonstrated the feasibility of the present broadband CW-DIAL technique for range-resolved water vapor remote sensing.

5.
Phytother Res ; 38(4): 1735-1744, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-37661763

RESUMO

Alzheimer's disease (AD) is a neurodegenerative disease. Senile plaques and intracellular neurofibrillary tangles are pathological hallmarks of AD. Recent studies have described the improved cognitive and neuroprotective functions of acteoside (AS). This study aimed to investigate whether the improved cognition of AS was mediated by Aß degradation and tau phosphorylation in APP/PS1 mice. The open field, Y maze, and novel object recognition tests were used to assess cognitive behavioral changes. We evaluated the levels of Aß40 and Aß42 in serum, cortex, and hippocampus, and Aß-related scavenging enzymes, phosphorylated GSK3ß and hyperphosphorylated tau in the cortex and hippocampus of APP/PS1 mice by western blotting. Our results revealed that AS treatment ameliorated anxious behaviors, spatial learning, and memory impairment in APP/PS1 mice and significantly reduced Aß deposition in their serum, cortex, and hippocampus. AS significantly increased Aß degradation, inhibited the hyperphosphorylation of tau, and significantly decreased the activity of GSK3ß, which is involved in tau phosphorylation. Altogether, these findings indicated that the beneficial effects of AS on AD-associated anxious behaviors and cognitive impairments could be attributed to promoting Aß degradation and inhibiting tau hyperphosphorylation, which might be partly mediated by GSK3ß.


Assuntos
Doença de Alzheimer , Glucosídeos , Polifenóis , Animais , Camundongos , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Modelos Animais de Doenças , Glicogênio Sintase Quinase 3 beta , Transtornos da Memória/tratamento farmacológico , Transtornos da Memória/metabolismo , Camundongos Transgênicos , Proteínas tau/metabolismo
6.
Water Res ; 250: 121017, 2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38118254

RESUMO

Bioretention systems are one of the most widely used stormwater control measures for urban runoff treatment. However, stable and effective dissolved nutrient treatment by bioretention systems is often challenged by complicated stormwater conditions. In this study, pyrite-only (PO), pyrite-biochar (PB), pyrite-woodchip (PW), and pyrite-woodchip-biochar mixed (M) bioretention systems were established to study the feasibility of improving both stability and efficiency in bioretention system via multi-media interaction. PB, PW, and M all showed enhanced dissolved nitrogen and/or phosphorus removal compared to PO, with M demonstrating the highest efficiency and stability under different antecedent drying durations (ADD), pollutant levels, and prolonged precipitation depth. The total dissolved nitrogen and dissolved phosphorus removal in M ranged between 64%-86% and 80%-95%, respectively, with limited organic matter and iron leaching. Pore water, microbial community, and material analysis collectively indicate that pyrite, woodchip, and biochar synergistically facilitated multiple nutrient treatment processes and protected each other against by-product leaching. Pyrite-woodchip interaction greatly increased nitrate removal by facilitating mixotrophic denitrification, while biochar further enhanced ammonium adsorption and expanded the denitrification area. The Fe3+ generated by pyrite aerobic oxidation was adsorbed on the biochar surface and potentially formed a Fe-biochar composite layer, which not only reduced Fe3+-induced pyrite excessive oxidation but also potentially increased organic matter adsorption. Fe (oxyhydr)oxides intermediate product formed by pyrite oxidation, in return, controlled the phosphorus and organic matter leaching from biochar and woodchip. Overall, this study demonstrates that multi-media interaction may enable bioretention systems to achieve stable and effective urban runoff treatment.


Assuntos
Carvão Vegetal , Ferro , Nitrogênio , Sulfetos , Nitrogênio/análise , Fósforo/análise , Chuva
7.
Transl Cancer Res ; 12(10): 2477-2492, 2023 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-37969387

RESUMO

Background: Polyamine metabolism is critically involved in the proliferation and metastasis of tumor cells, including in kidney renal clear cell (KIRC) cancer. However, the molecular mechanisms underlying the effect of polyamines in KIRC cancer remain largely unknown. Methods: The messenger RNA (mRNA) expression profile of KIRC was downloaded from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), and ArrayExpress database. Differential expression analysis was performed with the "limma" package in R. Univariate Cox regression and multivariable Cox regression were used to estimate correlation between variables and prognosis. Least absolute shrinkage and selection operator (LASSO) Cox regression analysis was employed to screen variables and construct a risk signature. A nomogram model was established using the risk signature and clinical variables. Receiver operating characteristic (ROC), calibration curve, and decision curve analysis (DCA) were used to assess the predicted accuracy and clinical benefit of the model. Results: We identified nine differentially expressed polyamine metabolism-related genes (PMRGs) in TCGA-KIRC. Of these, six were closely associated with patients' outcomes. These six genes participated in different pathways and originated from different cell types within the tumor microenvironment (TME). Using the mRNA expression values of these genes, we constructed a 4-gene PMRG risk signature. Patients with high PMRG risk exhibited worse outcomes, and our analysis showed that the PMRG risk signature was an independent prognostic factor when clinical information was used as a covariate. We also found that multiple immune- or metabolism-related pathways were differentially enriched in high or low PMRG risk groups, suggesting that altering these pathways could lead to different clinical outcomes. Finally, in two external datasets, we found that the PMRG risk signature could predict the response of patients to immune therapy. Conclusions: In summary, our study identified several potentially important PMRGs in KIRC and constructed a practical risk signature, which could serve as a foundation for further development of polyamine metabolism-based targeted therapies for KIRC.

8.
J Environ Manage ; 347: 119152, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37774660

RESUMO

The stormwater biofilter is a prevailing green infrastructure for urban stormwater management, but it is less effective in dissolved nitrogen removal, especially for nitrate. The mechanism that governs the nitrate leaching and performance stability of stormwater biofilters is poorly understood. In this study, a water quality model was developed to predict the ammonium and nitrate dynamics in a biochar-pyrite amended stormwater biofilter. The transport of dissolved nitrogen species was described by advection-dispersion models. The kinetics of adsorption and pyrite-based autotrophic denitrification are included in the model and simulated with a steady-state saturated flow. The model was calibrated and validated using eleven storm events. The modeling results reveal that the contribution of pyrite-based autotrophic denitrification to nitrate leaching alleviation improves with the increased drying duration. The nitrate removal efficiency was affected by a series of design parameters. Pyrite filling rate has a minor effect on nitrate removal promotion. Service area ratio and submerged zone depth are the key parameters to prevent nitrate leaching, as they influence the emergence and discharge time of nitrate breakthrough. The high inflow volume (high service area ratio) and small submerged zone can lead to earlier and increased discharge of peak nitrate otherwise the peak nitrate could be retained in the submerged zone and denitrified during the drying period. The developed mechanistic model provides a useful tool to evaluate the treatment ability of stormwater biofilters under varying conditions and offers a guideline for biofilter design optimization.


Assuntos
Nitratos , Nitrogênio , Ferro , Desnitrificação
9.
Opt Express ; 31(15): 24897-24913, 2023 Jul 17.
Artigo em Inglês | MEDLINE | ID: mdl-37475306

RESUMO

The molecular depolarization ratio (MDR) is of great significance for polarization lidar techniques in terms of validating the measurement accuracy, etc. However, previous studies mainly focused on cases with narrowband laser linewidths, and the transmittance of the Cabannes line in the receiver has been assumed constant. In this work, the narrowband theoretical model of MDR has been re-examined by taking the transmittance of the Cabannes line into account. A large relative deviation of beyond 200% has been found if the wavelength-shift reaches up to 0.5 nm for a receiving bandwidth of 0.5 nm at 532 nm, which is much larger than the case without considering the transmittance of the Cabannes line, i.e., only 15%, reported in previous studies. Besides, a broadband theoretical model has been proposed to evaluate the MDR for polarization lidar using high-power multimode laser diodes as light sources. Simulation studies have revealed that the MDR is highly related to the laser linewidth, the receiving bandwidth, as well as the wavelength-shift between the laser wavelength and the center wavelength of the receiver. The MDR at 520 nm calculated by the broadband theoretical model is about 21% larger than the value evaluated without considering the laser linewidth, when the receiving bandwidth is equivalent to the laser linewidth (e.g., 2 nm). Validation measurements, employing a 520-nm imaging-based polarization lidar with a 3.4-nm laser linewidth and a 10-nm receiving bandwidth, illustrated that the volume depolarization ratio in a clean atmospheric region (0.129±0.0025) was highly consistent with the theoretical MDR (0.132). The good agreement between theoretical and experimental results demonstrated a high measurement accuracy of the imaging-based polarization lidar and excellent feasibility of the broadband theoretical model.

10.
Artigo em Inglês | MEDLINE | ID: mdl-37440115

RESUMO

Microbial induced calcium carbonate precipitation (MICP) is widely common in nature, which belongs to biomineralization and has been explored carefully in recent decades. The paper studied the effect of temperature, initial pH value and Ca2+ concentration on bacterial growth and carbonic anhydrase activity, and then revealed the biomineralization process through the changes of Ca2+ concentration and calcification rate in alkali environment. Meanwhile, microbial healing agent containing spores and calcium nitrate was prepared and used for the early age concrete cracks repair. The self-healing efficiency was assessed by crack closure rate and water permeability repair rate. The experimental results showed that when the optimal temperature was 30 °C, the pH was 8.0-11.0, and the optimal Ca2+ concentration was 0-90 mM, the bacteria could grow better and the carbonic anhydrase activity was higher. Compared with reference, the crack closure rate with the crack width up to 0.339 mm could reach 95.62% and the water permeability repair rate was 87.54% after 28 d healing time of dry-wet cycles. XRD analysis showed that the precipitates at the crack mouth were calcite CaCO3. Meanwhile, the self-healing mechanism of mortar cracks was discussed in detail. In particular, there is no other pollution in the whole mineralization process, and the self-healing system is environmentally friendly, which provides a novel idea and method for the application of microbial self-healing concrete.

11.
PLoS One ; 18(7): e0288641, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37440578

RESUMO

Knowledge is an intrinsic element of environmental management. Understanding what kinds of knowledge are needed and how to communicate them effectively is crucial for building environmental management capacity. Despite extensive research, knowledge and its exchange are commonly considered from the viewpoint of its creators and disseminators, rather than that of its recipients. This can lead to mismatches between supply of and demand for knowledge, and futile knowledge exchange that undermines the effectiveness of interventions. Research is needed that looks carefully at the contexts and consequences of such scenarios. Addressing this gap, we examine the implementation of National Environmental Programs (NEPs) in north-western China, drawing from interviews and questionnaires with scientists, grassroots implementers, and farmers and herders, to identify what and how knowledge has been exchanged and what their perspectives are about knowledge exchange with other actors. We ascertain the positive impacts of knowledge exchange during NEP implementation, as well as the consequences when it is lacking, by analysing the interfaces and interactions between actors, seeking explanation for successes and failures. We conclude that with changing socio-ecological systems, knowledge and its exchange also need to change accordingly, extending beyond the environmental domain to integrate local socioeconomic concerns. Such efforts are necessary to improve environmental management outcomes and advance sustainable development.


Assuntos
Ecossistema , Médicos , Humanos , Desenvolvimento Sustentável , China , Conhecimento
12.
Opt Express ; 30(16): 28514-28533, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36299045

RESUMO

A visible, near-infrared (VIS-NIR) dual-polarization lidar technique employing laser diodes and polarization cameras has been designed and implemented for all-day unattended field measurements of atmospheric aerosols. The linear volume depolarization ratios (LVDR) and the offset angles can be retrieved from four-directional polarized backscattering signals at wavelengths of 458 nm and 808 nm without additional optical components and sophisticated system adjustments. Evaluations on the polarization crosstalk of the polarization camera and the offset angle have been performed in detail. A rotating linear polarizer (RLP) method based on the Stokes-Mueller formalism has been proposed and demonstrated for measuring extinction ratios of the polarization camera, which can be used to eliminate the polarization crosstalk between different polarization signals. The offset angles can be online measured with a precision of 0.1°, leading to negligible measurement errors on the LVDR. One-month statistical analysis revealed a small temporal variation of the offset angles, namely -0.13°±0.07° at 458 nm and 0.33°±0.09° at 808 nm, indicating good system stability for long-term measurement. Atmospheric measurements have been carried out to verify the system performance and investigate aerosol optical properties. The spectral characteristics of the aerosol extinction coefficient, the color ratio, the linear particle polarization ratio (LPDR) and the ratio of LPDR were retrieved and evaluated based on one-month continuous atmospheric measurements, from which different types of aerosols can be classified. The promising results showed great potential of employing the VIS-NIR dual-polarization lidar in characterizing aerosol optical properties, discriminating aerosol types and analyzing long-range aerosol transportation.

13.
Water Res ; 225: 119124, 2022 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-36162295

RESUMO

Media amendment has been more and more frequently tested in stormwater bioretention systems for enhanced runoff pollutant treatment. However, few studies systematically evaluated the amended system over a long time span, which hindered the further optimization of the proposed amended media. In this study, biochar-pyrite system (PB), conventional sand system (SB), and biochar-woodchip system (WB) were established and operated for 26 months. Media amendment greatly enhanced the dissolved nutrient removal, the highest total dissolved nitrogen removal in PB and WB were 65.6±3.6% and 68.2±2.5%, respectively. Compared with PB, WB could maintain excellent nitrogen removal under long-term operation. In contrast, PB demonstrated stable and more effective total dissolved phosphorus removal during all stages (73.1±3.1%-80.3±4.1%). A high content of phosphorus and organic matter was leached in WB especially at initial operation, while the initial pollutant leaching in PB and SB is much lower, about one-third of WB. Microbial and metabolic function analysis indicated that the microbial community in the bioretention system is complicated and stable. Media amendment enhanced microbial diversity and the relative abundance of functional genera related to nitrogen (Nitrospira, Thauera, Denitratisoma, etc.), sulfur (Thiobacillus, Geobacter, Desulfovibrio, etc.), and carbon cycles (cellulomonas, saccharimonadales, and SBR1031, etc.), which well explained the enhanced pollutant removal and by-product leaching in different systems. Overall, the current study indicates that although media amendment is conducive to enhanced dissolved nutrient removal in bioretention systems, it can hardly maintain both stability and efficiency from initial set-up to long-term operation. In practical application, catchment characteristics, prioritized pollutants, meteorological factors, etc. should all be considered before choosing suitable amended media and its design factors, thereby maximising the stability and efficiency of the bioretention system.


Assuntos
Poluentes Ambientais , Chuva , Areia , Fósforo , Nitrogênio , Enxofre
14.
Chemosphere ; 306: 135534, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35772517

RESUMO

Solid biomass waste amendment and substrates modification in bioretention systems have been increasingly used to achieve effective dissolved nutrients pollution control in stormwater runoff. However, the risk of excess chemical oxygen demand (COD) leaching from organic carbon sources is often overlooked on most occasions. Pyrite is an efficient electron donor for autotrophic denitrification, but little is known about the efficacy of autotrophic-heterotrophic synergistic effect between additional carbon source and pyrite in bioretention. Here, four bioretention columns (i.e., corncob column (C), pyrite column (P), the corncob-pyrite layered column (L-CP), and the corncob-pyrite mixed column (M-CP)) were designed and filled with soil, quartz sand, and modified media to reveal the synergistic effects. The results showed that the corncob-pyrite layered bioretention could maintain low COD effluent concentration with high stability and efficiency in treating dissolved nutrients. When the influent nitrogen and phosphorus concentrations were 8.46 mg/L and 0.94 mg/L, the average removal rates of ammonia nitrogen, total inorganic nitrogen, and phosphate were 83.6%, 70.52%, and 76.35%, respectively. The scouring experiment showed that placing the corncob in the mulch layer was beneficial to the sustained release of dissolved organic carbon (DOC). Erosion pits were found in the SEM images of used pyrite, indicating that autotrophic denitrifying bacteria in the bioretention could react with pyrite as an electron donor. The relative abundance of Thiobacillus in the submerged zone of the corncob-pyrite layered bioretention reached 38.39%, indicating that the carbon source in the mulch layer increased the relative abundance of Thiobacillus. Coexisting heterotrophic and autotrophic denitrification in this bioretention created a more abundant microbial community structure in the submerged zone. Overall, the corncob-pyrite layered bioretention is highly promising for stormwater runoff treatment, with effective pollution removal and minimal COD emission.


Assuntos
Desnitrificação , Zea mays , Carbono , Ferro , Nitrogênio , Nutrientes , Chuva , Resíduos Sólidos , Sulfetos
15.
Opt Express ; 29(23): 38512-38526, 2021 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-34808903

RESUMO

A portable polarization lidar system based on the division-of-focal-plane scheme has been proposed for all-day accurate retrieval of the atmospheric depolarization ratio. The polarization lidar system has been designed as a T-shaped architecture consisting of a closed transmitter and a detachable large focal receiver, which is capable of outdoor unmanned measurements. The lidar system features low cost, low maintenance and short blind range (∼100 m) by utilizing a 450 nm multimode laser diode as the light source and a polarization image sensor with four polarized channels as the detector. Validation measurements have been carried out on a near horizontal path in ten consecutive days. The linear volume depolarization ratio (LVDR) as well as its measurement uncertainty has been theoretically and experimentally evaluated without employing additional optical components and sophisticated online calibrations. The offset angle can also be accurately retrieved (i.e., -0.06°) from the four-directional polarized lidar profiles with a standard deviation of ±0.02° during the whole measurement period, which contributes negligible influence on the retrieval of the LVDR. It has been found out that the uncertainty of the LVDR was mainly originated from the random noise, which was below 0.004 at nighttime and may reach up to 0.008 during daytime owing to the increasing sunlight background. The performance of the polarization lidar system has been further examined through atmospheric vertical measurements. The low-cost low-maintenance portable polarization lidar system, capable of detecting four-directional polarized lidar signals simultaneously, opens up many possibilities for all-day field measurements of dust, cloud, urban aerosol, oriented particles, etc.

16.
Water Res ; 206: 117737, 2021 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-34637973

RESUMO

Bioretention system with modified media has been increasingly used to control dissolved nutrients in stormwater runoff. However, complicated removal processes and improper design have made most of them hardly achieve comprehensive dissolved nutrient removal and even show by-product generation problem, especially during extreme stormwater events. Here, a modified biochar-pyrite (FeS2) bi-layer bioretention system was developed and tested under various stormwater conditions with conventional sand-based and woodchip-based bioretention systems as controls. The modified system showed high stability and efficiency for dissolved nutrient treatment. The removal of dissolved organic nitrogen, ammonium, total dissolved nitrogen, and total dissolved phosphorus were 86.3-93.0%, 95.3-98.1%, 41.4-76.5%, and 69.7-88.2%, respectively. Stormwater conditions only influence nitrate removal which decreased with the increase of total received volume and increased with the extension of antecedent drying duration. Net sulfate and total iron generation were very low, less than 8 mg/L and 0.15 mg/L, respectively. Several microbiology, spectroscopy, and media related tests further demonstrated that the vadose zone and submerged zone showed synergy effects during operation. Biochar addition facilitated ammonium adsorption, nitrification, and in situ denitrification in the vadose zone. It also intercepted dissolved oxygen, which alleviated aerobic pyrite oxidation and created an anoxic condition for the submerged zone. Meanwhile, the pyrite-modified submerged zone achieved stable mixotrophic denitrification. The generated iron intermediate products further controlled phosphorus from both influent and vadose zone leaching into stable forms. Mixotrophic denitrification and potential sulfate reduction processes also reduce sulfate generation. Overall, the biochar-pyrite bi-layer bioretention is a highly promising technology for stormwater runoff treatment, with effective dissolved nutrient removal and minimal by-product generation in various stormwater conditions.


Assuntos
Desnitrificação , Ferro , Carvão Vegetal , Nitrogênio , Nutrientes , Chuva , Sulfetos
17.
Water Res ; 189: 116623, 2021 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-33207290

RESUMO

A novel water treatment process combining electrolysis, permanganate and ozone was tested in the laboratory. The combination showed synergistic effects in degrading various organic contaminants (like diclofenac, sulfamethoxazole, carbamazepine, etc.). A small amount of O3 (1 mg L-1, 60 mL min-1) significantly improved the oxidation and mineralization ability of an electro-permanganate process by generating more reactive manganese species and hydroxyl radicals. The combination required less energy consumption than comparable processes. Mechanism experiments showed that the ·OH involved was mainly generated by cathode reduction, homogeneous manganese catalysis, and heterogeneous manganese catalysis of O3 decomposition. Reactive Mn species were generated by electro-reduction, ·OH oxidation or/and O3 activation. In situ generated Mn (Ⅳ)s plays a vital role in generating ·OH and reactive Mn species. ·OH generated by O3 catalysis could transfer colloid Mn (Ⅳ)s to free Mn (Ⅴ)aq and Mn (Ⅵ) aq. And both the ·OH and RMnS played the dominant role for DCF removal. Increasing permanganate dosage, O3 concentration, the current density, Cl-, or humic acid, and decreasing the pH all enhanced the degradation of diclofenac, but the presence of PO43- or HCO3- inhibited it. Supplementing electrolysis with permanganate and O3 might be a practical, sustainable, and economical technology for treating refractory organics in natural waters.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Características da Família , Radical Hidroxila , Manganês , Compostos de Manganês , Oxirredução , Óxidos , Poluentes Químicos da Água/análise
18.
Phytother Res ; 35(1): 392-403, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33029835

RESUMO

Alzheimer's disease (AD), a neurodegenerative disease, has been, by and large, correlated to insulin pathway, glucose level, and energy metabolism in the brain. Intracerebroventricular administration of streptozotocin (ICV-STZ) leads to glucose and energy metabolism dysfunction, cognitive impairment, and increased oxidative stress in the brain. Acteoside has a myriad of pharmacological effects on the brain, namely, neuroprotection and recuperation of cognitive functions. The primary focus of the current study was to examine the effect of acteoside on insulin, glucose transport, and energy metabolism in the hippocampal area of the brain. The behavioral experiments such as spatial memory, active learning, and passive memory suggested that acetoside ameliorated the ICV-STZ-induced learning and cognitive impairment. The acteoside induced increase in the protein expression of glucose transporters (Glu T1, Glu T3, and Glu T4), glucose, and insulin levels in the hippocampus for maintaining normal learning and memory function were demonstrated by Western blot. In addition, acteoside's long-term oral administration increased the the ratio of ATP content divided by ADP content (ATP/ADP) ratio, which, in turn, reduced the reactiveoxygen species (ROS) level and improved the cellular oxidative stress response. Compared with the model group, the above results show significant differences in different degrees (p < .05 or p < .01). This study suggests that acteoside can ameliorate the ICV-STZ-induced learning and memory impairment caused due to insulin receptor, insulin receptor substrate 1, Glu T1, Glu T3, and Glu T4 pathways by triggering intracerebral metabolism.


Assuntos
Cognição/efeitos dos fármacos , Metabolismo Energético/efeitos dos fármacos , Glucose/metabolismo , Glucosídeos/uso terapêutico , Hipocampo/efeitos dos fármacos , Insulina/metabolismo , Fenóis/uso terapêutico , Doença de Alzheimer/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Disfunção Cognitiva/induzido quimicamente , Hipocampo/metabolismo , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Transtornos da Memória/induzido quimicamente , Ratos , Ratos Sprague-Dawley , Receptor de Insulina/metabolismo , Estreptozocina
19.
Appl Opt ; 59(29): 9087-9097, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-33104620

RESUMO

The NO2-differential absorption lidar (NO2-DIAL) technique has been of great interest for atmospheric NO2 profiling. Comprehensive studies on measurement errors in the NO2-DIAL technique are vital for the accurate retrieval of the NO2 concentration. This work investigates the systematic errors of the recently developed continuous-wave (CW) NO2-DIAL technique based on the Scheimpflug principle and a high-power CW multimode laser diode. Systematic errors introduced by various factors, e.g., uncertainty of the NO2 differential absorption cross-section, differential absorption due to other gases, spectral drifting of the λon and λoff wavelengths, wavelength-dependent extinction and backscattering effect, have been theoretically and experimentally studied for the CW-DIAL technique. By performing real-time spectral monitoring on the emission spectrum of the laser diode, the effect of spectral drifting on the NO2 differential absorption cross-section is negligible. The temperature-dependent NO2 absorption cross-section in the region of 220-294 K can be interpolated by employing a linear fitting method based on high-precision absorption spectra at 220, 240, and 294 K. The relative error for the retrieval of the NO2 concentration is estimated to be less than 0.34% when employing the interpolated spectrum. The primary interference molecule is found to be the glyoxal (CHOCHO), which should be carefully evaluated according to its relative concentration in respect to NO2. The systematic error introduced by the backscattering effect is subjected to the spatial variation of the aerosol load, while the extinction-induced systematic error is primarily determined by the difference between the aerosol extinction coefficients at λon and λoff wavelengths. A case study has been carried out to demonstrate the evaluation of systematic errors for practical NO2 monitoring. The comprehensive investigation on systematic errors in this work can be of great value for future NO2 monitoring using the DIAL technique.

20.
Appl Opt ; 59(22): 6729-6736, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32749378

RESUMO

Development of a lightweight, low-cost, easy-to-use and low-maintenance lidar technique has been of great interest for atmospheric aerosol remote sensing in recent years and remains a great challenge. In this work, an 808 nm mini-Scheimpflug lidar (SLidar) system with about 450 mm separation between the transmitter and the receiver has been developed by employing a 114 mm aperture Newtonian telescope (F4). System performances, such as the beam characteristic, the range resolution, and the signal-to-noise ratio of the lidar signal, have been carefully investigated. Despite employing a small receiving aperture, all-day measurements were still feasible with about a one-minute signal averaging for both the horizontal urban area monitoring and the slant atmospheric sounding in the boundary layer. The lidar signal in the region of 29-50 m with a scattering angle less than 179.5° could be slightly underestimated due to the variation of the phase function. The extinction coefficient evaluated in the region between 29 and 2000 m according to the Klett method agreed well with the concentrations of particulate matters for both horizontal and slant measurements. The promising result demonstrated in this work has shown great potential to employ the robust mini-SLidar system for atmospheric monitoring in the boundary layer.

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