Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 30
Filtrar
1.
BMC Pregnancy Childbirth ; 24(1): 123, 2024 Feb 10.
Artículo en Inglés | MEDLINE | ID: mdl-38341545

RESUMEN

BACKGROUND: Uterine leiomyomas are hormone-dependent benign tumors and often begin to shrink after menopause due to the reduction in ovarian steroids. The influence of pregnancy on uterine leiomyomas size remains unclear. Here, we present a case of spontaneous regression of a giant uterine leiomyoma after delivery. CASE PRESENTATION: A 40-year-old woman presented with multiple uterine leiomyomas, one of which is a giant uterine leiomyomas (approximately 8 cm in diameter) that gradually shrinked after delivery. At over two months postpartum, the large myometrial leiomyoma had transformed into a submucosal leiomyoma, and over 3 years postpartum, both the submucosal leiomyoma and multiple intramural leiomyomas completely regressed. CONCLUSION: Spontaneous regression of a giant uterine leiomyom is rare after delivery. Considering uterine leiomyoma regression until over 3 year postpartum,we need to observe the regression of uterine fibroid for a longer time postpartum in the absence of fibroid related complications. In addition, it will provide new insights for treatment options of uterine leiomyomas in the future.


Asunto(s)
Leiomioma , Neoplasias Uterinas , Embarazo , Femenino , Humanos , Adulto , Remisión Espontánea , Leiomioma/complicaciones , Neoplasias Uterinas/complicaciones , Útero/patología , Periodo Posparto
2.
Environ Sci Technol ; 53(13): 7913-7920, 2019 Jul 02.
Artículo en Inglés | MEDLINE | ID: mdl-31188572

RESUMEN

Coal-fired power plants represent the largest source of mercury emissions worldwide. Using fly ash, a byproduct of these plants, as a sorbent to remove mercury has proven to be difficult. Here, we found that the fresh surface of modified fly ash has good adsorption performance, and it declines obviously with time because of unsaturation characteristics on surface. On the basis of this mechanism, our study provides a method to in situ capture mercury with high surface energy modified fly ash by mechanochemical and bromide treatment. Fresh modified fly ash with active sites is injected into the flue to directly adsorb mercury. A continuous system within a full-scale 300 MWe plant showed that the mercury adsorption performance of the modified fly ash is similar to that of activated carbon, which is the industry benchmark for the treatment of mercury emission in fossil power generation units. This is a breakthrough and indicates that modified fly ash can become an efficient and convenient industrial sorbent for the removal of mercury.


Asunto(s)
Contaminantes Atmosféricos , Mercurio , Adsorción , Carbón Mineral , Ceniza del Carbón , Centrales Eléctricas
3.
J Environ Manage ; 161: 57-62, 2015 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-26150373

RESUMEN

The contamination of agricultural ground with estrogen compounds through application of animal wastes is a present concern. At the same time, current uses for waste fly ash having high carbon content are limited. To help mitigate these problems, we examine using waste fly ash as a useful adsorbent for Estradiol in pig waste digests. In this study, Estradiol was added to vials containing water and fly ash from several different power plants. After an extraction process, the amount of Estradiol in the water was measured. Commercial activated carbon was also used for comparison purposes. Vials containing varying concentrations of Estradiol and no trapping material were used as a control. The results from this study indicate that fly ash can be used as a trapping material for Estradiol in water, but that commercially available activated carbon can trap about an order of magnitude more Estradiol than the fly ash and that the effects of the fly ash matrix can both inhibit and promote the solvation of Estradiol into water depending possibly upon pH and cation concentration effects. In addition, preliminary extraction studies using pig waste digest indicate that fly ash can be used as adsorbent for Estradiol present in pig waste.


Asunto(s)
Fraccionamiento Químico/métodos , Ceniza del Carbón/química , Estradiol/aislamiento & purificación , Contaminantes Químicos del Agua/aislamiento & purificación , Animales , Carbono/química , Estradiol/química , Concentración de Iones de Hidrógeno , Estiércol , Centrales Eléctricas , Porcinos , Contaminantes Químicos del Agua/química
4.
J Environ Sci (China) ; 33: 156-62, 2015 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-26141888

RESUMEN

In this study, the mercury adsorption characteristics of HBr-modified fly ash in an entrained-flow reactor were investigated through thermal decomposition methods. The results show that the mercury adsorption performance of the HBr-modified fly ash was enhanced significantly. The mercury species adsorbed by unmodified fly ash were HgCl2, HgS and HgO. The mercury adsorbed by HBr-modified fly ash, in the entrained-flow reactor, existed in two forms, HgBr2 and HgO, and the HBr was the dominant factor promoting oxidation of elemental mercury in the entrained-flow reactor. In the current study, the concentration of HgBr2 and HgO in ash from the fine ash vessel was 4.6 times greater than for ash from the coarse ash vessel. The fine ash had better mercury adsorption performance than coarse ash, which is most likely due to the higher specific surface area and longer residence time.


Asunto(s)
Contaminantes Atmosféricos/química , Ceniza del Carbón/química , Ácido Bromhídrico/química , Compuestos de Mercurio/química , Adsorción
5.
J Hazard Mater ; 472: 134537, 2024 Jul 05.
Artículo en Inglés | MEDLINE | ID: mdl-38759279

RESUMEN

Experimental studies assessed the removal efficiency and fine-size distribution of CPM coupled with compositional analysis across air pollution control device systems (APCDs) at an ultra-low emission (ULE) power plant. The findings indicated total CPM emissions were reduced to a minimum of 0.418 mg/m3 at the Wet Electrostatic Precipitator (WESP). The Wet Flue Gas Desulfurization (WFGD) showed the highest removal efficiency (98%) across all particle sizes, notably in the ultra-micron range. Selective Catalytic Reduction (SCR) demonstrated a mere 34% overall efficiency, with a negative removal rate in the ultra-fine particle range. The WESP effectively removed CPM only in sub-micron and ultra-micron sizes, but significantly increased water-soluble ions formation in ultra-fine spatially suspended CPM (CPMspa), leading to overall negative efficiency. Thus, the removal efficiency of the ultra-fine particle range was most affected among the three particle size ranges when the flue gas went through the APCDs. Major metal elements and water-soluble ions were more readily removed by APCDs due to their surface aggregation, while the removal of trace elements like Hg and Se was limited. Reducing SO42-/NH4+ formation in SCR, and optimizing WESP spray system operations based on flue gas components are essential steps in controlling CPM concentration in ULE power plants.

6.
J Med Chem ; 67(11): 9091-9103, 2024 Jun 13.
Artículo en Inglés | MEDLINE | ID: mdl-38778566

RESUMEN

Induction of cuproptosis and targeting of multiple signaling pathways show promising applications in tumor therapy. In this study, we synthesized two thiosemicarbazone-copper complexes ([CuII(L)Cl] 1 and [CuII2CuI(L)2Cl3] 2, where HL is the (E)-N-methyl-2-(phenyl(pyridin-2-yl)methylene ligand), to assess their antilung cancer activities. Both copper complexes showed better anticancer activity than cisplatin and exhibited hemolysis comparable to that of cisplatin. In vivo experiments showed that complex 2 retarded the A549 cell growth in a mouse xenograft model with low systemic toxicity. Primarily, complex 2 kills lung cancer cells in vitro and in vivo by triggering multiple pathways, including cuproptosis. Complex 2 is the first mixed-valent Cu(I/II) complex to induce cellular events consistent with cuproptosis in cancer cells, which may stimulate the development of mixed-valent copper complexes and provide effective cancer therapy.


Asunto(s)
Antineoplásicos , Complejos de Coordinación , Cobre , Neoplasias Pulmonares , Tiosemicarbazonas , Tiosemicarbazonas/química , Tiosemicarbazonas/farmacología , Tiosemicarbazonas/síntesis química , Tiosemicarbazonas/uso terapéutico , Humanos , Cobre/química , Animales , Neoplasias Pulmonares/tratamiento farmacológico , Neoplasias Pulmonares/patología , Antineoplásicos/farmacología , Antineoplásicos/química , Antineoplásicos/síntesis química , Antineoplásicos/uso terapéutico , Complejos de Coordinación/farmacología , Complejos de Coordinación/química , Complejos de Coordinación/síntesis química , Complejos de Coordinación/uso terapéutico , Ratones , Ratones Desnudos , Adenocarcinoma del Pulmón/tratamiento farmacológico , Adenocarcinoma del Pulmón/patología , Línea Celular Tumoral , Adenocarcinoma/tratamiento farmacológico , Adenocarcinoma/patología , Células A549 , Proliferación Celular/efectos de los fármacos , Ensayos Antitumor por Modelo de Xenoinjerto , Transducción de Señal/efectos de los fármacos , Relación Estructura-Actividad , Hemólisis/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales , Ratones Endogámicos BALB C
7.
J Environ Sci (China) ; 25(9): 1858-64, 2013 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-24520729

RESUMEN

The mercury flux in soils was investigated, which were amended by gypsums from flue gas desulphurization (FGD) units of coal-fired power plants. Studies have been carried out in confined greenhouses using FGD gypsum treated soils. Major research focus is uptakes of mercury by plants, and emission of mercury into the atmosphere under varying application rates of FGD gypsum, simulating rainfall irrigations, soils, and plants types. Higher FGD gypsum application rates generally led to higher mercury concentrations in the soils, the increased mercury emissions into the atmosphere, and the increased mercury contents in plants (especially in roots and leaves). Soil properties and plant species can play important roles in mercury transports. Some plants, such as tall fescue, were able to prevent mercury from atmospheric emission and infiltration in the soil. Mercury concentration in the stem of plants was found to be increased and then leveled off upon increasing FGD gypsum application. However, mercury in roots and leaves was generally increased upon increasing FGD gypsum application rates. Some mercury was likely absorbed by leaves of plants from emitted mercury in the atmosphere.


Asunto(s)
Sulfato de Calcio , Carbón Mineral , Gases/química , Mercurio/química , Centrales Eléctricas , Contaminantes del Suelo/química , Azufre/química , Plantas/química , Agua
8.
Neurosci Bull ; 39(5): 745-758, 2023 May.
Artículo en Inglés | MEDLINE | ID: mdl-36587114

RESUMEN

Diabetic neuropathic pain (DNP) is the most common disabling complication of diabetes. Emerging evidence has linked the pathogenesis of DNP to the aberrant sprouting of sensory axons into the epidermal area; however, the underlying molecular events remain poorly understood. Here we found that an axon guidance molecule, Netrin-3 (Ntn-3), was expressed in the sensory neurons of mouse dorsal root ganglia (DRGs), and downregulation of Ntn-3 expression was highly correlated with the severity of DNP in a diabetic mouse model. Genetic ablation of Ntn-3 increased the intra-epidermal sprouting of sensory axons and worsened the DNP in diabetic mice. In contrast, the elevation of Ntn-3 levels in DRGs significantly inhibited the intra-epidermal axon sprouting and alleviated DNP in diabetic mice. In conclusion, our studies identified Ntn-3 as an important regulator of DNP pathogenesis by gating the aberrant sprouting of sensory axons, indicating that Ntn-3 is a potential druggable target for DNP treatment.


Asunto(s)
Diabetes Mellitus Experimental , Neuropatías Diabéticas , Neuralgia , Ratones , Animales , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/metabolismo , Axones/fisiología , Células Receptoras Sensoriales/metabolismo , Neuralgia/metabolismo
9.
J Air Waste Manag Assoc ; 62(2): 139-50, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22442930

RESUMEN

A pilot-scale field study was carried out to investigate the distribution of Hg and other selected elements (i.e., As, B, and Se), i.e., emission to ambient air, uptake by surface vegetation, and/or rainfall infiltration, after flue gas desulfurization (FGD) material is applied to soil. Three FGD materials collected from two power plants were used. Our results show Hg released into the air and uptake in grass from all FGD material-treated soils were all higher (P < 0.1) than the amounts observed from untreated soil. Hg in the soil amended with the FGD material collected from a natural oxidation wet scrubber (i.e., SNO) was more readily released to air compared to the other two FGD materials collected from the synthetic gypsum dewatering vacuum belt (i.e., AFO-gypsum) and the waste water treatment plant (i.e., AFO-CPS) of a forced oxidation FGD system. No Hg was detected in the leachates collected during the only 3-hour, 1-inch rainfall event that occurred throughout the 4-week testing period. For every kilogram of FGD material applied to soil, AFO-CPS released the highest amount of Hg, B, and Se, followed by SNO, and AFO gypsum. Based on the same energy production rate, the land application of SNO FGD material from Plant S released higher amounts of Hg and B into ambient air and/or grass than the amounts released when AFO-gypsum from Plant A was used. Using FGD material with lower concentration levels of Hg and other elements of concern does not necessary post a lower environmental risk. In addition, this study demonstrates that considering only the amounts of trace elements uptake in surface vegetation may under estimate the overall release of the trace elements from FGD material-amended soils. It also shows, under the same soil amendment conditions, the mobility of trace elements varies when FGD materials produced from different processes are used.


Asunto(s)
Contaminantes Atmosféricos/análisis , Residuos Industriales/análisis , Mercurio/análisis , Poaceae/metabolismo , Suelo/análisis , Aire/análisis , Fertilizantes , Mercurio/metabolismo , Proyectos Piloto , Centrales Eléctricas , Oligoelementos/metabolismo
10.
Environ Pollut ; 302: 119107, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35248619

RESUMEN

3D hierarchical porous biochar (HPBC) was synthesized by a thermally removable template without post-activation. Zn(NO3)2 decomposition produced gases and ZnO in situ to activate and expand the three-dimensional micro-and mesopores. Compared with pristine biochar (BC), the specific surface area and pore volume of HPBC were increased by 223 and 75 times, respectively. The abundant pore structure of HPBC significantly enhanced the diffusion rate of heavy metals. For example, compared to BC, the time required for HPBC to adsorb Pb2+ reach adsorption equilibrium was reduced by 87.5% (40 min vs 5min). Such an adsorption performance of HPBC was also insensitive to different background ions (K+, Na+, Ca2+, and Mg2+) with a much higher concentration than that of heavy metals. When applied to treat desulfurization wastewater from power plants, HPBC yielded 100% removal of Pb2+ and Cd2+, much higher than that by using commercial activated carbon (28%). Molecular dynamics simulation revealed different locations preferred by the adsorption of Pb2+ (micropores) and Cd2+ (mesopores) in the hierarchical pore structures. The adsorption of Pb2+ and Cd2+ on HPBC was mainly achieved by diffusion, oxygen functional group complexation, and precipitation. These results provided better knowledge to understand the microscopic adsorption mechanisms of heavy metals in hierarchical pores and a facile yet robust strategy to design such structures in biochar for efficient wastewater treatment.


Asunto(s)
Contaminantes Químicos del Agua , Óxido de Zinc , Adsorción , Cadmio/química , Carbón Orgánico/química , Plomo , Simulación de Dinámica Molecular , Porosidad , Aguas Residuales , Contaminantes Químicos del Agua/análisis
11.
Environ Sci Pollut Res Int ; 29(29): 44709-44722, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35133594

RESUMEN

Coal ash has emerged as an important alternative source for rare earth elements (REEs). The enrichment and occurrence form of REEs among coal combustion products are of great significance for both technical design and economic evaluation of recovering REEs from the coal ash. Here, the enrichment and occurrence form of REEs in the ash were investigated. Compared with ashes from muffle furnace, coal fly ash (CFA) from power plants involved higher enrichment ratio of REEs, which was explained by the fractionation of coal ashes to concentrate REEs in finer CFA, higher combustion temperature to vaporize more volatile elements, and longer residence time of fly ash to absorb REEs in the gas. In addition, CFA samples were analyzed by sequence chemical extraction procedure (SCEP) and scanning electron microscope with an energy dispersive spectrometer (SEM-EDX), which revealed the important role of aluminum in the occurrence form of REEs compared with Si in aluminosilicates of CFA. This conclusion was further confirmed by thermodynamic equilibrium calculation, which also agreed qualitatively with the observation that REEs mainly existed in the solid phase. Both experimental and computational results of this work provided insights to understand the distribution of REEs in CFA and optimize their extraction processes.


Asunto(s)
Carbón Mineral , Metales de Tierras Raras , Fraccionamiento Químico , Carbón Mineral/análisis , Ceniza del Carbón/análisis , Centrales Eléctricas
12.
J Environ Sci (China) ; 23(1): 171-6, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21476358

RESUMEN

Flue gas from coal combustion contains significant amounts of volatile selenium (Se). The capture of Se in the flue gas desulfurization (FGD) scrubber unit has resulted in a generation of metal-laden residues. It is important to determine Se speciation to understand the environmental impact of its disposal. A simple method has been developed for selective inorganic Se(IV), Se(VI) and organic Se determination in the liquid-phase FGD residues by hydride generation atomic fluorescence spectrometry (AFS). It has been determined that Se(IV), Se(VI) and organic Se can be accurately determined with detection limits (DL) of 0.05, 0.06 and 0.06 microg/L, respectively. The accuracy of the proposed method was evaluated by analyzing the certified reference material, NIST CRM 1632c, and also by analyzing spiked tap-water samples. Analysis indicates that the concentration of Se is high in FGD liquid residues and primarily exists in a reduced state as selenite (Se(IV)). The toxicity of Se(IV) is the strongest of all Se species. Flue gas desulfurization residues pose a serious environmental risk.


Asunto(s)
Gases/química , Selenio/química , Azufre/química , Borohidruros/química , Ácido Nítrico/química , Eliminación de Residuos Líquidos , Abastecimiento de Agua/análisis
13.
Sci Total Environ ; 787: 147597, 2021 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-33992943

RESUMEN

Particle-bound mercury discharged with fine particulate matter from coal-fired power plants causes atmospheric pollution that impacts human health. In this study, the speciation and size-specific distribution of particle-bound mercury in filterable particulate matter (FPM) from an ultra-low emission power plant and condensable particulate matter (CPM) from an entrained flow reactor were analyzed. Most importantly, particle-bound mercury was enriched in fine particles smaller than 0.02 µm, whose mass fraction was several orders of magnitude higher than that in large particles. Particularly, HgBr2, HgCl2, and HgO were major mercury species in FPM, whereas CPM involves mostly HgCl2 with a small portion of HgBr2. The occurrence of these species was also confirmed by a thermodynamic equilibrium calculation. The results further revealed the effects of air pollution control devices (APCDs) on the speciation of particle-bound mercury. Specifically, an electrostatic precipitator (ESP) removed most particle-bound mercury. Similarly, wet flue gas desulfurization (WFGD) dramatically reduced particle-bound mercury for most particles, except those between 0.1 and 1 µm. At the outlet of WFGD, mercury bound with FPM10 (smaller than 10 µm) is only 0.15% of the total mercury at the inlet of selective catalytic reduction (SCR). This knowledge provides insights that can be used to design and optimize the control strategy for mercury emission in power plants.

14.
Sci Total Environ ; 754: 142150, 2021 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-32920404

RESUMEN

The purpose of this research was to improve the sorption ability of Pb and Cd by promoting the ion exchange and precipitation capacity of biochar. The adsorption performance and mechanisms of Pb and Cd in wastewater using coconut shell biochar modified with magnesium were investigated. After modification, the total adsorption capacity (Qt) of Pb and Cd on Mg-coated biochar (MgBC400) increased by 20 and 30 times compared with the unmodified biochar (BC400), respectively. The removal of Pb and Cd to biochar was attributed to ion exchange (Qe), mineral precipitation (Qp), interaction with oxygen functional groups (OFGs) [(Qf)], and metal-π electron coordination (Qπ). Compared with the BC400, the adsorption capacity of the four fractions of MgBC400 increased especially the ion exchange and precipitation. The Qe values of MgBC400 were almost 49 and 59 times that of BC400 in the adsorption of Pb and Cd, respectively. The Qp values of MgBC400 increased by 214.4 and 81.7 mg/g, respectively. Ion exchange and mineral precipitation dominated the adsorption of Pb and Cd by MgBC400.


Asunto(s)
Cadmio , Aguas Residuales , Adsorción , Cadmio/análisis , Carbón Orgánico , Intercambio Iónico , Plomo
15.
J Environ Sci (China) ; 22(2): 277-82, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20397418

RESUMEN

Air pollution control devices (APCDs) are installed at coal-fired power plants for air pollutant regulation. Selective catalytic reduction (SCR) and wet flue gas desulfurization (FGD) systems have the co-benefits of air pollutant and mercury removal. Configuration and operational conditions of APCDs and mercury speciation affect mercury removal efficiently at coal-fired utilities. The Ontario Hydro Method (OHM) recommended by the U.S. Environmental Protection Agency (EPA) was used to determine mercury speciation simultaneously at five sampling locations through SCR-ESP-FGD at a 190 MW unit. Chlorine in coal had been suggested as a factor affecting the mercury speciation in flue gas; and low-chlorine coal was purported to produce less oxidized mercury (Hg2+) and more elemental mercury (Hg0) at the SCR inlet compared to higher chlorine coal. SCR could oxidize elemental mercury into oxidized mercury when SCR was in service, and oxidation efficiency reached 71.0%. Therefore, oxidized mercury removal efficiency was enhanced through a wet FGD system. In the non-ozone season, about 89.5%-96.8% of oxidized mercury was controlled, but only 54.9%-68.8% of the total mercury was captured through wet FGD. Oxidized mercury removal efficiency was 95.9%-98.0%, and there was a big difference in the total mercury removal efficiencies from 78.0% to 90.2% in the ozone season. Mercury mass balance was evaluated to validate reliability of OHM testing data, and the ratio of mercury input in the coal to mercury output at the stack was from 0.84 to 1.08.


Asunto(s)
Contaminantes Atmosféricos/química , Contaminación del Aire/prevención & control , Carbón Mineral/análisis , Mercurio/química
16.
Bioresour Technol ; 297: 122388, 2020 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-31734064

RESUMEN

After the co-combustion of tobacco stem/black bean straw/wheat straw/millet straw/corn stalk/rice straw and coal, it was found that all tested biomass in this study could inhibit arsenic release, but only rice straw promoted arsenic release. When the acid washed biomass was mixed with coal during combustion, the release of arsenic increased. When mineral metals (Na, K, Mg, Ca, Al and Fe) and Si elements were added to the coal, the mineral metals inhibited arsenic release. However, the release of arsenic was increased when the silicon content in biomass was high. The volatiles in the biomass also promoted the release of arsenic during co-combustion. The arsenic in the ash generated from co-combustion was mainly in the sulphide-bound state. Co-combustion of biomass and coal reduced the occurrence of an exchangeable state in the ash, and also significantly reduce the possibility of leaching.


Asunto(s)
Arsénico , Carbón Mineral , Biomasa , Ceniza del Carbón , Minerales
17.
J Colloid Interface Sci ; 580: 77-87, 2020 Nov 15.
Artículo en Inglés | MEDLINE | ID: mdl-32682118

RESUMEN

The performance of a supercapacitor (SCs) fabricated from coal-based activated carbon was studied in terms of its specific capacitance (C), life cycle and rate performance. In this work, a low cost modified nitrogen-doped coal-based activated carbon (MACN) was prepared by KOH/H2O co-activation from lignite. Experimental results and density functional theory (DFT) calculations showed that introducing nitrogen atoms into the coal-based activated carbon leads to a rearrangement of the carbon skeleton structure and changes the surface chemical environment. Leading to the MACN internal disorder increases (ID/IG is up to 0.99), structural stability improves (TGA curves shift right), and various nitrogen functional groups (N-5, N-6, N-Q) are formed on the carbon surface. In addition, the MACN possesses high specific surface area (SBET: 2129 m2/g), abundant micropores (Vmic: 0.62 cm3/g), appropriate mesopores (Vmes: 0.39 cm3/g, Vmes ratio: 38.6%), low impurity content, and highly N-doping (9.59 wt%). These characteristics of the MACN provide for a high C of 323 F/g at a current density of 0.5 A/g. The enhanced MACN is 64.8% higher than the undoped MAC. Furthermore, a high energy density of 10 Wh/kg can be achieved with a MACN-assembled symmetrical cell when the power density of 250 W/kg in 6 M KOH.

18.
J Hazard Mater ; 381: 120986, 2020 01 05.
Artículo en Inglés | MEDLINE | ID: mdl-31430639

RESUMEN

A series of Mn-Ce/SAPO-34 catalysts were prepared to study the catalytic oxidisation of elemental mercury (Hg0). Sulphur tolerance and SO3 formation over the catalyst were studied further. Hg0 was transported by compressed air from PSA Cavkit. NO, SO2, and NH3 are standard gases, and H2O is produced by gas carrying. Mn could incorporate into the cerium oxide lattice to form capping oxygen and well-dispersed high valance manganese ions after the addition of Ce, which was conducive to NO removal and Hg0 oxidisation. 9 Mn-9Ce showed the best performance regarding Hg0 conversion, achieving more than 92% Hg0 conversion efficiency at 50-300 °C. The sulphur resistance of the Mn-based catalyst was significantly improved after the addition of cerium due to the high affinity of Ce for SO2, and the relative content of HgSO4 was exceeded 72% on the 9 Mn-9Ce catalyst with SO2; SO3 formation over the 9 Mn-9Ce decreased by 17% compared with the 9 Mn. H2O not only reduced the available active site, but also decreased the oxidation rate of SO2. The active sites were preferentially occupied by NH3 rather than Hg0 and SO2, generated NH4+ occupied cation vacancies. Therefore, both H2O and NH3 have inhibitory effects on Hg0 conversion and SO3 formation.

19.
Medicine (Baltimore) ; 99(1): e18536, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31895789

RESUMEN

It remains challenging for endoscopists to manage pancreaticobiliary diseases in patients with ectopic papilla of Vater by endoscopic retrograde cholangiopancreatography (ERCP). The present study sought to evaluate the efficacy and safety of ERCP for this issue.Consecutive patients with ectopic papilla of Vater who underwent initial ERCP due to pancreaticobiliary diseases were retrospectively analyzed.One hundred seven patients with ectopic papilla of Vater were included. The success rate of cannulation was 83.2%. Endoscopic sphincterotomy, endoscopic papillary balloon dilation, and mechanical lithotripsy were performed in 12 (11.2%), 25 (23.4%), and 1 (0.9%) patients, respectively. The technical success rate was 83.2%; of these, endoscopic nasobiliary drainage, endoscopic retrograde biliary drainage, endoscopic retrograde pancreatic drainage, and stone extraction was conducted in 61 (57.0%), 17 (15.9%), 5 (4.7%), and 45 (42.1%) patients, respectively. Bile duct stone size ≥1 cm, number ≥2, and duodenum stenosis were risk factors for stone extraction inability. Adverse events occurred in 20 (18.7%) patients, including post-ERCP pancreatitis (3.7%), hyperamylasemia (12.1%), and infection of biliary tract (2.8%); all of the adverse events were mild and alleviated by conventional therapies.ERCP is an appropriate choice for pancreaticobiliary diseases in patients with ectopic papilla of Vater due to its high efficacy and safety. Bile duct stone size ≥1 cm, number ≥2, and duodenum stenosis increase difficulties for stone extraction.


Asunto(s)
Ampolla Hepatopancreática , Enfermedades de las Vías Biliares/cirugía , Colangiopancreatografia Retrógrada Endoscópica/métodos , Coristoma/cirugía , Enfermedades Duodenales/cirugía , Enfermedades Pancreáticas/cirugía , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
20.
Bioresour Technol ; 291: 121859, 2019 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-31362200

RESUMEN

The adsorption mechanisms of Pb(II) and Cd(II) in aqueous solution using camellia seed husk biochars pyrolyzed at different temperatures were studied. The adsorption of Pb(II) and Cd(II) on biochars are mainly controlled by ion exchange, oxygen functional groups (OFGs) complexation, Pb(II)/Cd(II)-π interactions, and precipitation with minerals. Compared to the raw biochars, both carboxyl and phenolic hydroxyl groups increased in the biochars washed with HCl. However, the previous research ignored the effect of the increased OFGs. Thus, a revised method was proposed from this study to more accurately calculate the contribution of four different mechanisms. Precipitation with minerals was the dominant mechanism for Pb(II) and Cd(II) removal, accounting for 80.61-89.03% and 53.57-75.84%, respectively, of the total adsorption as the pyrolysis temperature increased from 300 °C to 700 °C. As for oxygen functional groups complexation, the percentage of Pb(II) and Cd(II) removal were 4.76-8.55% and 11.34-29.59%, respectively.


Asunto(s)
Cadmio/química , Carbón Orgánico/química , Ácido Clorhídrico/química , Plomo/química , Oxígeno/química , Adsorción , Calor , Oxidación-Reducción , Pirólisis
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA