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1.
Proc Biol Sci ; 287(1932): 20200935, 2020 08 12.
Artigo em Inglês | MEDLINE | ID: mdl-32752985

RESUMO

Sulfoxaflor is a globally important novel insecticide that can have negative impacts on the reproductive output of bumblebee (Bombus terrestris) colonies. However, it remains unclear as to which life-history stage is critically affected by exposure. One hypothesis is that sulfoxaflor exposure early in the colony's life cycle can impair larval development, reducing the number of workers produced and ultimately lowering colony reproductive output. Here we assess the influence of sulfoxaflor exposure on bumblebee larval mortality and growth both when tested in insolation and when in combination with the common fungal parasite Nosema bombi, following a pre-registered design. We found no significant impact of sulfoxaflor (5 ppb) or N. bombi exposure (50 000 spores) on larval mortality when tested in isolation but found an additive, negative effect when larvae received both stressors in combination. Individually, sulfoxaflor and N. bombi exposure each impaired larval growth, although the impact of combined exposure fell significantly short of the predicted sum of the individual effects (i.e. they interacted antagonistically). Ultimately, our results suggest that colony-level consequences of sulfoxaflor exposure for bumblebees may be mediated through direct effects on larvae. As sulfoxaflor is licensed for use globally, our findings highlight the need to understand how novel insecticides impact non-target insects at various stages of their development.


Assuntos
Abelhas/fisiologia , Inseticidas/toxicidade , Nosema , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais
2.
J Environ Manage ; 271: 110986, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32778279

RESUMO

As the disposal of phosphogypsum can result in severe contamination of soil and groundwater, several researchers worldwide have devoted efforts toward realizing suitable methods for PG disposal. This study demonstrates the feasibility of using phosphogypsum as the sole CaO source in the preparation of calcium sulfoaluminate cement by considering its mechanical properties and the potential environmental impacts of its large-scale utilization. First, the effects of the alumina/silica ratio on the mineral phase formation, setting time, compressive strength, and microstructure of calcium sulfoaluminate cement were studied. An alumina/silica ratio of 2.0 or 2.5 resulted in satisfactory mineral phase formation and compressive strength; the compressive strength of calcium sulfoaluminate cement reached 63.2, 88.5, and 100.2 MPa after 1, 3, and 28 d of curing, respectively. Second, the environmental behaviors of harmful impurities in the raw materials and calcium sulfoaluminate cement were investigated. In the static leaching and acid leaching tests, the concentrations of harmful elements in the calcium sulfoaluminate cement leachates met the requirements of national standards (GB/T14848-2007). After a period of curing, P and some heavy metals (Mn, Cr, Ni, Cu, and As) did not leach from the cement. Finally, a novel process and a system of preparing CSA cement by using phosphogypsum as the sole CaO source are proposed. This novel technology could be employed as a reliable and environment friendly means of recycling phosphogypsum in the large-scale preparation of calcium sulfoaluminate cement.


Assuntos
Compostos de Alumínio , Compostos de Cálcio , Sulfato de Cálcio , Óxidos , Fósforo , Compostos de Enxofre
3.
Mar Pollut Bull ; 152: 110940, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32479301

RESUMO

Distributions and variations of biogenic sulfur compounds including dimethylsulfide (DMS), dissolved and total dimethylsulfoniopropionate (DMSPd and DMSPt) and acrylic acid (AA) were investigated in coastal waters off Qingdao, China during the late-bloom and after-bloom periods of the Ulva prolifera bloom of 2015. DMSPd, DMS and AA concentrations after the bloom were significantly higher than during the late-bloom, but DMSPt concentrations in surface waters began to decrease. High concentrations of these compounds in the surface layer were associated with the bloom, with the exception of increased concentrations of DMSPt in the middle layer as decaying U. prolifera debris settled. The sea-to-air fluxes of DMS were estimated to be 18.08 and 24.24 µmol m-2 d-1 during the late-bloom and after-bloom, and about three times higher than the reported average fluxes of the Yellow Sea, which highlighted the impacts of U. prolifera blooms on DMS emissions.


Assuntos
Ulva , China , Eutrofização , Sulfetos/análise , Compostos de Enxofre
4.
Chemosphere ; 256: 127077, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32438124

RESUMO

The ultra-deep adsorptive desulfurization (ppb level) of benzene remains a challenging subject with the need to construct efficient adsorbent systems. Herein, a kind of ruthenium-based adsorbent functionalized with bimetallic Ru-Al was rationally designed using Al2O3 as support (denoted as 0.8%Ru-1.2%Al/Al2O3). It was found that the co-anchoring of Ru and Al species endows the Ru-based adsorbent unique adsorption capability, which is able to completely eliminate sulfur compounds in benzene, and exhibiting a much higher breakthrough sulfur capacity than that of the 0.8%Ru/Al2O3. Remarkably, under the industrial experiment conditions, 0.8%Ru-1.2%Al/Al2O3 exhibited excellent long-term stability for more than 1200 h, showing the potential for industrial application. Various characterization techniques, including BET, XRD, SEM, TEM, TPD-MS, TPR and XPS, were used to investigate the correlation between the adsorption performance and the microstructure of the adsorbents. Over 0.8%Ru-1.2%Al/Al2O3, the ultra-thin aluminum additive is beneficial to improve the dispersion of Ru species, which therefore exhibits desirable desulfurization efficiency. Moreover, the enhanced performance is also correlated to the presence of the suitable Ru active centers generated from the selective coverage by Al species. It leads to an optimal exposure of the Ru active centers, which would facilitate the interaction of S-Ru and the improvement of the desulfurization activity.


Assuntos
Benzeno/análise , Rutênio/química , Adsorção , Alumínio , Óxido de Alumínio/química , Espaços Confinados , Enxofre , Compostos de Enxofre
5.
Chemosphere ; 256: 126986, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32445995

RESUMO

Systemic neurotoxic insecticides are widely used to control aphid pests worldwide and their potential non-target effects on aphid predators are often unknown. Behavioral responses linked to biological control services are crucial when assessing the compatibility of chemicals with biocontrol organisms. This is particularly relevant for insecticides at low and sublethal concentrations. We studied the acute toxicity and the sublethal effect on the voracity of the generalist predator Harmonia axyridis (Coleoptera: Coccinellidae) caused by the exposure to three systemic insecticides routinely used against aphids. The tested insecticide concentrations were the Lethal Concentration 50% (LC50), 20% (LC20) and 1% (LC1) estimated for the target pest Aphis gossypii (Hemiptera: Aphididae) in a companion study. The survival and the voracity differed among the tested chemicals and concentrations, but only thiamethoxam at LC50 caused a significant predator mortality, and individuals that survived showed a reduced predation rate. The predators showed a density independent functional response after the exposure to most of the insecticide-concentration combinations, while an inverse density dependence of the prey consumption rate was observed for coccinellids exposed to sulfoxaflor and thiamethoxam at their lowest tested concentration. The estimated parameters, i.e., the attack rate and the prey handling time, were affected at higher concentrations by both imidacloprid and sulfoxaflor. These findings stress the importance of carefully evaluating side effects of insecticides at very low concentrations on beneficial arthropods in the risk assessment schemes for sustainable pest control programmes.


Assuntos
Afídeos/efeitos dos fármacos , Inseticidas/toxicidade , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Animais , Afídeos/fisiologia , Besouros/efeitos dos fármacos , Dose Letal Mediana , Comportamento Predatório/efeitos dos fármacos , Piridinas , Compostos de Enxofre , Tiametoxam
6.
Plant Foods Hum Nutr ; 75(3): 355-361, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32388808

RESUMO

Organosulfur compounds (OSCs) of garlic have various health benefits including anti-hypertensive effect. It has been described that volatile OSCs uptake occurs into a moderate extent. Among the bioavailable OSCs present in garlic, 2-vinyl-4H-1,3-dithiin (2VD) is a main component in garlic macerated oil and stir-fried garlic but has been poorly investigated compared with others OSCs, such allyl mercaptan (AM) and S-allyl cysteine (SAC). The aim of this study was to evaluate the effects of 2VD on vascular smooth muscle cells (VSMCs) isolated from spontaneous hypertensive rats (SHR) and compare them with those produced by AM and SAC. Cell viability and proliferation were measured using tetrazolium dye MTT assay and flow cytometry. Cell migration was evaluated by scrape-wound migration assay. OSCs anti-oxidative capacity was determined by measuring reactive oxygen species (ROS) generation, and total antioxidant status (TAS). Non-toxic plasmatic concentrations (10 µg L-1) of 2VD and AM inhibited VSMCs proliferation stimulated with 5% fetal bovine serum and impaired cell migration. In further flow cytometry analysis 2VD treatment resulted in a partial cell cycle arrest at G2 phase. The OSCs tested were able to prevent ROS increase after angiotensin II stimulation and surprisingly 2VD induced higher total antioxidant status compared with AM and SAC. Our results showed that 2VD produces equivalent or superior beneficial effects on VSMCs to those reported for other bioavailable compounds of garlic. This preliminary evidence suggests that 2VD intake could also exert important protective effects against arterial remodeling in hypertension.


Assuntos
Alho , Animais , Antioxidantes , Proliferação de Células , Compostos Heterocíclicos , Músculo Liso Vascular , Estresse Oxidativo , Ratos , Compostos de Enxofre , Compostos de Vinila
7.
Pestic Biochem Physiol ; 166: 104582, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32448428

RESUMO

A key to effective insect pest management and insecticide resistance management is to provide growers with a range of new tools as potential alternatives to existing compounds or approaches. Sulfoxaflor (Isoclast™ active) is a new sulfoximine insecticide which is active on a broad range of sap-feeding insects, including species that have reduced susceptibility to currently used insecticides, such as imidacloprid from the neonicotinoid class. Sulfoxaflor (SFX) and imidacloprid (IMI) were tested in laboratory bioassays to compare the susceptibility of field populations of green peach aphid, Myzus persicae (Sulzer), exhibiting varying degrees of resistance involving an alteration (R81T) to the insect nicotinic acetylcholine receptor. The LC50 values for M. persicae exposed to SFX ranged from 0.09 to 1.31 (mg litre-1), whereas when the same populations were exposed to IMI the LC50 values ranged from 0.6 to 76.2 (mg litre-1). M. persicae were significantly more sensitive to SFX as compared to IMI for nine of the 13 populations tested. For M. persicae populations confirmed to be homozygous susceptible (ss) or heterozygous rs) for the R81T point mutation, there was no significant differences in the observed LC50 values for either SFX or IMI relative to the susceptible reference population (15LP1). However, in all M persicae populations that were homozygous (rr) for the R81T point mutation, susceptibility was significantly less to IMI as compared to the reference population with resistance ratios ranging from 22.1 to 63.5-fold. In contrast, only one homozygous resistant population (15MP9) exhibited a statistically significant change in susceptibility (RR = 10-fold) to SFX as compared to the reference population, which was far less than the 56-fold observed for imidacloprid in that same population. Thus, this study indicates there is no specific correlation between the laboratory efficacy of SFX and IMI in field collected populations in Spain displaying varying degrees of resistance to IMI. Furthermore, the presence of target site resistance in M. persicae to IMI, in the form of the R81T mutation, does not a priori translate to a reduction in sensitivity to sulfoxaflor. Consequently, SFX can be an effective tool for use in insect pest management programs for green peach aphid. These data also serve as a baseline reference for green peach aphid sensitivity to SFX prior to commercial uses in Spain.


Assuntos
Afídeos , Prunus persica , Receptores Nicotínicos , Animais , Mutação , Neonicotinoides , Nitrocompostos , Piridinas , Espanha , Compostos de Enxofre
8.
Environ Sci Pollut Res Int ; 27(24): 30571-30582, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32468370

RESUMO

Odor emissions from sewer systems and wastewater treatment plants have attracted much attention due to the potential negative effects on human health. A single-chamber membrane-free microbial electrolysis cell was proposed for the removal of sulfides in a sewer system. The feasibility of the use of volatile sulfur compounds and their removal efficiency in liquid and headspace gas phases were investigated using synthetic wastewater with real sewer sediment and Ru/Ir-coated titanium electrodes. The results indicate that hydrogen sulfide and volatile organic sulfur compounds were effectively inhibited in the liquid phase upon electrochemical treatment at current densities of 1.55, 2.06, and 2.58 mA/cm2, and their removal rates reached up to 86.2-100%, except for dimethyl trisulfide, the amount of which increased greatly at 1.55 mA/cm2. In addition, the amount of volatile sulfur compounds in the headspace decreased greatly; however, the total theoretical odor concentration was still high, and methanethiol and ethanethiol greatly contributed to the total strength of the odor concentration due to their low odor threshold concentrations. The major pathway for sulfide removal in the single-chamber membrane-free microbial electrolysis cell is biotic oxidation, the removal rate of which was 0.4-0.5 mg/min, 4-5 times that of indirect electrochemical oxidation.


Assuntos
Compostos de Enxofre , Compostos Orgânicos Voláteis , Eletrólise , Odorantes , Sulfetos , Enxofre
9.
PLoS One ; 15(5): e0232812, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407334

RESUMO

Sulfoxaflor, the first commercially available sulfoximine insecticide, has been used for the control of sap-feeding insect pests such as plant bugs and aphids on a variety of crops. However, its sublethal effects on the mirid bug Apolygus lucorum, one of the key insect pests of Bt cotton and fruit trees in China, have not been fully examined. Here, we evaluated the demography and feeding behaviour of A. lucorum exposed to sulfoxaflor. The leaf-dipping bioassay showed that the LC10 and LC30 of sulfoxaflor against 3rd-instar nymphs of this insect were 1.23 and 8.37 mg L-1, respectively. The LC10 significantly extended the nymphal duration and decreased the oviposition period by 5.29 days and female fecundity by 56.99% in the parent generation (F0). The longer duration of egg, 5th-instar nymphs, preadult, and male adult longevity were observed in the F1 generation (F1) at LC10. At the LC30, the duration of egg and 1st-instar nymph, female adult longevity, and oviposition period of the F1 were significantly shorter, while the nymphal duration in the F0 and duration of 5th-instar nymphs, preadult survival rate, and male adult longevity in the F1 significantly increased. The net reproductive rate (R0), intrinsic rate of increase (r), and finite rate of increase (λ) in the F1 were not significantly affected by these two concentrations, whereas the mean generation time (T) was lower at the LC30. Additionally, the probe counts and cells mixture feeding time were markedly lengthened by the LC10 and LC30, respectively, when A. lucorum nymphs exposed to sulfoxaflor fed on Bt cotton plants without insecticides. These results clearly indicate that sulfoxaflor causes sublethal effects on A. lucorum and the transgenerational effects depend on the tested concentrations.


Assuntos
Heterópteros/patogenicidade , Inseticidas/farmacologia , Controle de Pragas , Piridinas/farmacologia , Compostos de Enxofre/farmacologia , Animais , Fertilidade/efeitos dos fármacos , Frutas/parasitologia , Gossypium/parasitologia , Heterópteros/efeitos dos fármacos , Humanos , Longevidade/efeitos dos fármacos , Ninfa/efeitos dos fármacos , Ninfa/patogenicidade , Oviposição/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Árvores/parasitologia
10.
PLoS One ; 15(5): e0233033, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32437365

RESUMO

Pesticide exposures can have detrimental impacts on bee pollinators, ranging from immediate mortality to sub-lethal impacts. Flupyradifurone is the active ingredient in Sivanto™ and sulfoxaflor is the active ingredient in Transform®. They are both relatively new insecticides developed with an intent to reduce negative effects on bees, when applied to bee-attractive crops. With the growing concern regarding pollinator health and pollinator declines, it is important to have a better understanding of any potential negative impacts, especially sub-lethal, of these pesticides on bees. This study reports novel findings regarding physiological stress experienced by bees exposed to field application rates of these two insecticides via a Potter Tower sprayer. Two contact exposure experiments were conducted-a shorter 6-hour study and a longer 10-day study. Honey bee mortality, sugar syrup and water consumption, and physiological responses (oxidative stress and apoptotic protein assays) were assessed in bees exposed to Sivanto™ and Transform®, and compared to bees in control group. For the longer, 10-day contact exposure experiment, only the Sivanto™ group was compared to the control group, as high mortality recorded in the sulfoxaflor treatment group during the shorter contact exposure experiment, made the latter group unfeasible to test in the longer 10-days experiment. In both the studies, sugar syrup and water consumptions were significantly different between treatment groups and controls. The highest mortality was observed in Transform® exposed bees, followed by the Sivanto™ exposed bees. Estimates of reactive oxygen/nitrogen species indicated significantly elevated oxidative stress in both pesticide treatment groups, when compared to controls. Caspase-3 protein assays, an indicator of onset of apoptosis, was also significantly higher in the pesticide treatment groups. These differences were largely driven by post exposure duration, indicating sub-lethal impacts. Further, our findings also emphasize the need to revisit contact exposure impacts of Sivanto™, given the sub-lethal impacts and mortality observed in our long-term (10-day) contact exposure experiment.


Assuntos
4-Butirolactona/análogos & derivados , Abelhas/efeitos dos fármacos , Praguicidas/efeitos adversos , Piridinas/efeitos adversos , Compostos de Enxofre/efeitos adversos , 4-Butirolactona/efeitos adversos , Animais , Abelhas/metabolismo , Caspase 3/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Proteínas de Insetos/metabolismo , Estresse Oxidativo , Polinização , Fatores de Tempo
11.
J Chromatogr A ; 1619: 460947, 2020 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-32268954

RESUMO

A simple, portable and battery-powered trapping device (iTrap) consisting of a purification tube, a trapping unit and a miniature air pump was developed for the pre-concentration of volatile organic sulfur compounds (VOSCs). The tested VOSCs, including methanthiol (MT), ethanethiol (ET), dimethyl sulfide (DMS), diethyl sulfide (DES) and dimethyl disulfide (DMDS), were firstly purged from water samples and then in situ pre-concentrated with the iTrap prior to their analysis by thermal desorption gas chromatography coupling with a sulfur chemiluminescence detector (TD-GC-SCD). Twenty-six adsorbents were studied to find the most suitable adsorbent for the efficient pre-concentration of VOSCs. Under optimal conditions, limits of detection of 6, 8, 6, 2 and 3 ng L-1 were obtained for MT, ET, DMS, DES and DMDS, respectively. The precisions were better than 5.3% (relative standard deviations, RSDs). The iTrap was successfully applied for the analysis of VOSCs in Certified Reference Materials, several surface water, underground water and wastewater samples collected from Pengzhou city, Sichuan, China. Moreover, the VOSCs trapped in the iTrap were much more stable than those directly stored in water samples and the recoveries for all samples could be maintained at acceptable levels (>73%), even their preservation time as long as 8 h.


Assuntos
Cromatografia Gasosa , Monitoramento Ambiental/métodos , Compostos de Enxofre/isolamento & purificação , Compostos Orgânicos Voláteis/isolamento & purificação , Águas Residuárias/química , China , Monitoramento Ambiental/instrumentação , Luminescência , Compostos de Enxofre/análise , Compostos Orgânicos Voláteis/análise
12.
Sci Total Environ ; 727: 138285, 2020 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-32325311

RESUMO

This study aimed to identify the individual effect of biochemical composition on odor emission potential of biowaste during aerobic biodegradation. Three kinds of typical mixed wastes, including vegetable-fruit waste, garden waste, and protein-rich waste, were tested for emission quantity of seven common odorous families within 21 days of biodegradation under aerobic conditions. The cumulative odor yields (COY) were as follows: protein-rich waste (2408 µg g-1 DM) > vegetable-fruit waste (1169 µg g-1 DM) > garden waste (62 µg g-1 DM), and their cumulative odor intensity were 16,701, 1888, and 212 g-1 DM, respectively. The odor emission of vegetable-fruit waste mainly occurred in the first 3 days, accounting for 91.7% COY, and the predominant contributor to odor intensity (PCOI) were terpenes and sulfur compounds. With regard to garden waste, the odor emission rate was the highest on day 1 (22.4 µg g-1 DM d-1) and then rapidly decreased, and the PCOI were aldehydes. The odor emission rate of protein-rich waste increased gradually in the initial stage and reached the peak value on day 10 (661.9 µg g-1 DM d-1), and its PCOI were sulfur compounds. This study revealed for the first time the relationship between the odor emission potential of biowaste and its characteristic of biochemical composition, then proposed potential application for odor pollution control during aerobic composting.


Assuntos
Compostagem , Eliminação de Resíduos , Biodegradação Ambiental , Odorantes , Compostos de Enxofre , Verduras
13.
Environ Sci Pollut Res Int ; 27(17): 21533-21541, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32279264

RESUMO

Microcystis aeruginosa is one of the most common algae found in eutrophicated water bodies. Alkaline phosphatase (AKP) can be produced by Microcystis aeruginosa to utilize organic phosphates under phosphorus deficiency stress, thereby AKP can be regarded as an important indicator for algal growth. Sulfur compounds are ubiquitous in waters, while investigation on the interactions between sulfur compounds and Microcystis aeruginosa is limited. In this work, we introduced 33 types of sulfur compounds to culture Microcystis aeruginosa, and the results demonstrated that algal growth is positively related to AKP activities. Toxicity of organic sulfur compounds was further evaluated using Toxicity Estimation Software Tool based on quantitative structure-activity relationship prediction. The algal growth results exhibited strong correlation to the toxicity endpoints suggesting the organic sulfur compounds inhibits the algal growth as toxic matters. K-means cluster analyses have been carried out subsequently via Python based on the results of algal growth and AKP activities of each sample and statistically, the sulfur compounds can be adequately clustered into 2 groups. According to clustering results, sulfonic acids exhibit low toxicity while sulfur amino acids can be considered as more toxic compounds. Graphical abstract Varied sulfur compounds (33 types) were investigated to find out the interactions between them and Microcystis aeruginosa, a common alga. K-means cluster and correlation analyses demonstrate that algal growth and alkaline phosphatase activities exhibited strong correlation to the predicted toxicity endpoints.


Assuntos
Microcystis , Fosfatase Alcalina , Fósforo , Compostos de Enxofre
14.
Chemosphere ; 253: 126637, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32278910

RESUMO

A kinetic study was carried out in a sequencing batch reactor (SBR) (125 mg NH4+-N/L) inoculated with a physiologically stable nitrifying sludge not previously acclimated to sulfur compounds and fed at different initial sulfide concentrations (2.5-20.0 mg HS--S/L). Up to 10.0 mg HS--S/L, the nitrifying process kept stable and complete, reaching an ammonium consumption efficiency (ENH4+) of 100% and a nitrate yield (YNO3-) of 0.95 ± 0.03 mg NO3--N/mg NH4+-N consumed. At 15.0 and 20.0 mg HS--S/L, after an initial alteration in the nitrite oxidizing process, the YNO2- was decreasing throughout the cycles and the YNO3- increasing, obtaining in the last cycle at 20.0 mg HS--S/L, an ENH4+ of 100%, a YNO2- of zero, and a YNO3- of 0.80 mg NO3--N/mg NH4+-N consumed. At the end of the period at 20.0 mg HS--S/L, the specific rates of ammonium consumption and nitrate formation were 15 and 55% lower than their respective values in the control period without sulfide addition, showing that the sludge had a better metabolic adaptation for ammonium oxidizing activity than for nitrite oxidizing activity. The sludge acquired a higher sulfide oxidation capacity along the cycles. Bacterial population dynamics assessment indicated that the ammonium oxidizing bacteria (AOB) community was more diverse and stable than the nitrite oxidizing bacteria (NOB) community. The use of consortia with a previously stabilized nitrifying activity in SBR may constitute an alternative for eliminating simultaneously ammonium by nitrification and sulfide by sulfide oxidation and be implemented for the treatment of wastewater with ammonium and sulfide.


Assuntos
Compostos de Amônio/metabolismo , Sulfetos/metabolismo , Eliminação de Resíduos Líquidos/métodos , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Cinética , Nitratos/metabolismo , Nitrificação , Nitritos/metabolismo , Oxirredução , Dinâmica Populacional , Esgotos/microbiologia , Compostos de Enxofre/metabolismo , Águas Residuárias
15.
Ecotoxicol Environ Saf ; 196: 110555, 2020 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247961

RESUMO

A strategy for clean fuel by selective adsorption processing was deemed to be convenient and environmental-friendly in past decades. However, the development of adsorption desulfurization was tremendously subject to the fabrication of high-performance adsorbents with large capacity and high stability. Herein, we designed a novel route to fabricate the cloth-like carbon nanofiber film with a hierarchical porous structure by electrospinning. The structure and properties of the cloth-like carbon nanofiber films were determined by a series of characterizations. Subsequently, the desulfurization performance of the cloth-like carbon nanofiber films was examined by the simulated thiophene (TH) oil. Furthermore, the effect of adsorption conditions on the adsorption capacity was intensively investigated, such as carbonization temperature, initial concentration and desulfurization temperature. The results found that at optimal calcination temperature of 700 °C, the cloth-like carbon nanofiber films possessed the highest micropore volume (Vmic = 0.185 m3/g) and adsorption capacity (qe = 96.6 mg/g) at 800 mg/L initial concentration under the adsorption temperature of 25 °C. The results corroborated that the physical properties of the cloth-like carbon nanofiber films with the surface area of 417.8 m2/g, the total pore volume of 0.187 cm3/g and average pore diameter of 1.36 nm had an important influence on the high adsorption capacity. On this basis, the adsorption experimental data were best fitted to pseudo-second-order kinetic and Langmuir isotherm models. Furthermore, the other highlight of the cloth-like carbon nanofiber films was convenient for the separation from oil, thus achieving the desirable reused performance.


Assuntos
Carbono/química , Óleos Combustíveis/análise , Nanofibras/química , Compostos de Enxofre/isolamento & purificação , Adsorção , Cinética , Porosidade , Propriedades de Superfície , Temperatura , Têxteis
16.
Respir Investig ; 58(3): 212-215, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32171700

RESUMO

Endobronchial volatile sulfur compounds in patients with lung abscess or lung cancer were measured using the Oral Chroma™ gas chromatograph. High levels of hydrogen sulfide and methyl mercaptan were observed in some patients with lung abscess but not in patients with lung cancer. Measuring endobronchial volatile sulfur compounds could be useful for the rapid diagnosis of lung abscess caused by obligate anaerobes.


Assuntos
Bactérias Anaeróbias , Infecções Bacterianas/diagnóstico por imagem , Infecções Bacterianas/microbiologia , Brônquios/metabolismo , Cromatografia Gasosa/métodos , Abscesso Pulmonar/diagnóstico , Abscesso Pulmonar/microbiologia , Compostos de Enxofre/análise , Biomarcadores/análise , Humanos , Sulfeto de Hidrogênio/análise , Projetos Piloto , Volatilização
17.
J Chromatogr A ; 1621: 461033, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32188563

RESUMO

A diethylammonio-propylsulfate amphoteric ionic resin was synthesized and employed as the stationary phase for high-performance liquid chromatography-mass spectrometry (LC-MS) separation and detection of amino acids. The influence of experimental conditions such as mobile phase composition, column length and temperature upon the amino acid separations was evaluated. However, temperature, addition of water-miscible organic solvent to the mobile phase and mobile phase gradients were not effective at improving the separations. In contrast, the use of an unbuffered pure water mobile phase proved successful for the separation and detection of amino acids. The observed order of elution seems to parallel the isoelectric points of the respective amino acids and suggests that this diethylammonio-propylsulfate stationary phase column functions as an amphoteric ion-exchanger. Under optimized chromatographic conditions, the detection limits for the amino acids were in range of 0.07-0.44 pmol (pico-mole). The method was also successfully applied for the analysis of an actual commercial sample.


Assuntos
Aminoácidos/análise , Cromatografia Líquida de Alta Pressão/métodos , Espectrometria de Massas/métodos , Compostos de Enxofre/química , Aminoácidos/isolamento & purificação , Íons , Solventes/química , Água/química
18.
Proc Natl Acad Sci U S A ; 117(10): 5510-5515, 2020 03 10.
Artigo em Inglês | MEDLINE | ID: mdl-32094166

RESUMO

Insect nervous systems offer unique advantages for studying interactions between sensory systems and behavior, given their complexity with high tractability. By examining the neural coding of salient environmental stimuli and resulting behavioral output in the context of environmental stressors, we gain an understanding of the effects of these stressors on brain and behavior and provide insight into normal function. The implication of neonicotinoid (neonic) pesticides in contributing to declines of nontarget species, such as bees, has motivated the development of new compounds that can potentially mitigate putative resistance in target species and declines of nontarget species. We used a neuroethologic approach, including behavioral assays and multineuronal recording techniques, to investigate effects of imidacloprid (IMD) and the novel insecticide sulfoxaflor (SFX) on visual motion-detection circuits and related escape behavior in the tractable locust system. Despite similar LD50 values, IMD and SFX evoked different behavioral and physiological effects. IMD significantly attenuated collision avoidance behaviors and impaired responses of neural populations, including decreases in spontaneous firing and neural habituation. In contrast, SFX displayed no effect at a comparable sublethal dose. These results show that neonics affect population responses and habituation of a visual motion detection system. We propose that differences in the sublethal effects of SFX reflect a different mode of action than that of IMD. More broadly, we suggest that neuroethologic assays for comparative neurotoxicology are valuable tools for fully addressing current issues regarding the proximal effects of environmental toxicity in nontarget species.


Assuntos
Exposição Ambiental , Reação de Fuga/efeitos dos fármacos , Inseticidas/toxicidade , Neurônios Motores/efeitos dos fármacos , Neonicotinoides/toxicidade , Nitrocompostos/toxicidade , Piridinas/toxicidade , Compostos de Enxofre/toxicidade , Animais , Habituação Psicofisiológica/efeitos dos fármacos , Dose Letal Mediana , Locusta migratoria/efeitos dos fármacos , Movimento (Física)
19.
Chemosphere ; 244: 125466, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32050325

RESUMO

Untreated sludge (total solids = 10%) and thermally hydrolysed sludge (total solids = 10%) were subjected to high-solid anaerobic digestion (HSAD) to study the effect of thermal hydrolysis pre-treatment (THP) on the conversion pathways of volatile sulphur compounds (VSCs). Typical VSCs were detected in the gas produced by THP at 160 °C for 30 min, including H2S, methyl mercaptan (MM), dimethyl sulphide (DMS) and dimethyl disulphide (DMDS). After THP, the organic sulphide ratio in the treated sludge had decreased from 96% to 90%, and inorganic sulphide had increased from 4% to 10%. In the THS (THP + HSAD) group, the productivity and total volume of VSCs were significantly increased. These results suggest that THP directly promotes converting organic sulphur (OS) into VSCs. Further tests revealed that THP increased the activity of reductases (adenine phosphate sulphate reductase and sulphite reductase), OS hydrolysis was the main source of VSCs in biogas, and MM could be converted into H2S (78%), DMS (18%) and DMDS (4%). These findings are used to elucidate the conversion pathway of sulphides in HSAD.


Assuntos
Esgotos/química , Compostos de Enxofre/química , Anaerobiose , Biocombustíveis/análise , Temperatura Alta , Hidrólise , Volatilização
20.
Phytochemistry ; 173: 112293, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32062197

RESUMO

Seven previously undescribed sulfur-containing compounds, (+)- and (-)-xanthiazinone A, (+)- and (-)-xanthiazinone B, (+)- and (-)-xanthiazinone C and xanthiazinone D, and four known thiazinedione derivatives, together with three thiophene derivatives were isolated from the fruits of Xanthium sibiricum. Racemic xanthiazinones A-C were separated by chiral HPLC columns. Their chemical structures were elucidated based on extensive spectroscopic analyses, ECD calculations, and single crystal X-ray diffractions. The X-ray crystallographic analyses for xanthiazinones A-C represent the first example described for the structure elucidation of the thiazinedione with the five-membered lactone ring attached via an oxygen atom. Accordingly, the previously proposed structure for xanthiazinone was revised. The anti-inflammatory and cytotoxic activities were evaluated for all the isolated compounds. (+)-xanthiazinone B and 2-hydroxy-xanthiazone exhibited potent inhibitory effects against nitric oxide production in lipopolysaccharide-activated RAW 264.7 mouse macrophage cells with IC50 values of 8.75 and 10.90 µM, respectively. All compounds obviously were inactive for three human tumor cell lines (HepG2, MCF-7, and A549) with IC50 values more than 10 µM.


Assuntos
Xanthium , Animais , Anti-Inflamatórios , Frutas , Humanos , Camundongos , Enxofre , Compostos de Enxofre
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