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1.
Sensors (Basel) ; 22(17)2022 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-36081062

RESUMEN

Carbon fibers and resin used in manufacturing carbon fiber-reinforced plastic composite structures flow before the resin solidifies, resulting in disrupted fiber orientation and non-uniform thickness. This process, known as consolidation, is critical for the quality of the composite structure, but no technology exists to measure the deformation in situ. This study proposes a strip-type embeddable shape sensor based on fiber optics for in situ monitoring of consolidation deformation. The sensor consists of a thin, flexible sheet with optical fibers embedded in the upper and lower surfaces of the sheet, and it can monitor out-of-plane bending deformation in composite materials during consolidation. Finite element analysis and experiments are used to evaluate the basic performance of the shape sensor before it is applied to composite gap/lap monitoring. For the first time, the relaxation of consolidation deformation due to the flow of fiber-resin suspension is measured. The proposed sensor will be a powerful tool for elucidating consolidation mechanisms and for validating composite manufacturing simulations.


Asunto(s)
Resinas Compuestas , Tecnología de Fibra Óptica , Resinas Compuestas/química , Tecnología de Fibra Óptica/métodos , Análisis de Elementos Finitos , Fibras Ópticas
2.
Sensors (Basel) ; 18(10)2018 Oct 13.
Artículo en Inglés | MEDLINE | ID: mdl-30322123

RESUMEN

When inert gas containing water molecules flows into a metal pipe, the water molecules cannot exit instantaneously from the outlet of the pipe but are captured at adsorption sites on the inner surface of the pipe until most of the sites are occupied. A theoretical model and a subsequent experiment in this article show that the delay time depends on the amount of moisture level; the higher the moisture-level, the shorter the delay time. Based on the result, we propose a new method and its implementation to the validation of a standard moisture generation to be used in the field measurement such as in factories and pipe lines.

3.
Water Environ Res ; 84(2): 120-7, 2012 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-22515061

RESUMEN

In this study, a method for removing water from biosolids that uses dimethyl ether (DME) as an extractant was considered. This study evaluates the applicability of the DME dewatering method to biosolid cakes by using a DME flow-type experimental apparatus. It was found that a high dewatering ratio is clearly achieved by increasing the liquefied DME/biosolid ratio and lowering the liquefied DME linear velocity. As the liquefied DME/biosolid ratio was increased, the carbon content in dewatered biosolid showed a slight decrease and the TOC concentration in separated liquid increased significantly. Finally, the input energy Es to remove 1 kg of water from the biosolid cake, using both the DME dewatering method and the conventional drying method was estimated. The calculation shows that Es for the DME dewatering process is approximately a third of Es for the conventional thermal drying process.


Asunto(s)
Éteres Metílicos/química , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Agua/química
4.
J Ocul Pharmacol Ther ; 38(1): 85-91, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34936495

RESUMEN

Purpose: We assessed the effect of rebamipide ophthalmic solution on corneal epithelial injury due to benzalkonium chloride (BAK) by fluorescein (FL) staining and corneal resistance (CR). Methods: After determining the absence of corneal epithelial damage by FL and CR, rebamipide ophthalmic solution (50 µL) was instilled five times, each interspaced by 5 min, into one eye of mature New Zealand white rabbits, and likewise physiological saline was instilled into the contralateral eye as the control. After 30 min, eyes were similarly treated with one of the following solutions: BAK solution 0.02%, latanoprost ophthalmic solution (0.02% BAK), or latanoprost ophthalmic solution without BAK. The presence of corneal epithelial damage was quantitated at 10, 30, and 60 min by CR after the last instillation. FL staining was also performed at 60 min after the last instillation. Results: CR ratios (%) at 60 min after the last instillation in rebamipide/BAK and rebamipide/latanoprost (0.02% BAK) groups were significantly increased by 18.3% and 25.6% compared with saline/BAK and saline/latanoprost (0.02% BAK) groups, respectively (P < 0.05). Findings by FL staining were consistent with those by CR; BAK and latanoprost with BAK groups were positive, and eyes with the most severe area and density of corneal epithelial damage (A2D2) were in the saline/BAK group. Conclusion: The rebamipide ophthalmic solution reduces the severity of corneal epithelial injury caused by BAK, an ophthalmic solution preservative.


Asunto(s)
Alanina/análogos & derivados , Antioxidantes/farmacología , Compuestos de Benzalconio/farmacología , Epitelio Corneal/efectos de los fármacos , Epitelio Corneal/lesiones , Conservadores Farmacéuticos/farmacología , Quinolonas/farmacología , Alanina/farmacología , Animales , Quimioterapia Combinada , Latanoprost/farmacología , Masculino , Conejos , Distribución Aleatoria
5.
Water Environ Res ; 83(1): 23-5, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-21291024

RESUMEN

We proposed a method for the deodorising and dewatering of biosolids. In the proposed method, liquefied dimethyl ether (DME) was used as an extractant for odorous components and water. We developed a bench-scale experiment to almost completely deodorize and dewater biosolids by using liquefied DME at room temperature. The deodorized and dewatered biosolids have sufficient caloric density and can be used as a carbon neutral fuel.


Asunto(s)
Éteres Metílicos/química , Odorantes , Aguas del Alcantarillado/química , Contaminantes Químicos del Agua/química , Agua/química , Biocombustibles
6.
J Ocul Pharmacol Ther ; 37(2): 97-103, 2021 03.
Artículo en Inglés | MEDLINE | ID: mdl-33439755

RESUMEN

Purpose: We sought to evaluate the effect of antiglaucoma ophthalmic solutions on the cornea with a corneal resistance device (CRD), and to compare the results with those by fluorescein staining. Methods: In 6 rabbit groups (n = 7 each), right eyes were administered latanoprost ophthalmic solution containing 0.02% benzalkonium chloride (BAK); dorzolamide/timolol (1%/0.5%) containing 0.005% BAK; dorzolamide/timolol without BAK; dorzolamide/timolol+latanoprost with 0.02% BAK; 0.005% BAK; or 0.02% BAK to the conjunctival sac 3 × at 15-min intervals. Left (control) eyes were administered saline. Baseline and post-treatment corneal resistance (CR) were measured. The CR ratio = CR before versus after treatment. We evaluated superficial punctate keratitis by fluorescein staining using area and density (AD) grades. Results: In the dorzolamide/timolol-without BAK group, there were no significant difference in the CR ratio between the control and treatment eyes at any time point. In the 0.005%-BAK group at 30 min and the other 4 groups at all time points, the CR ratio differed significantly between the control and treatment eyes (P < 0.05). AD grades were 0 in all control eyes and the dorzolamide/timolol-without BAK and 0.005% BAK treatment eyes. Conclusions: Nonpreservative ophthalmic solutions (and those with low BAK concentrations) do not significantly affect corneal electrical resistance. Eye drop ingredients other than BAK may be involved in altering corneal electrical resistance. CRDs may detect corneal epithelium changes not revealed by fluorescein staining.


Asunto(s)
Antihipertensivos/uso terapéutico , Córnea/efectos de los fármacos , Impedancia Eléctrica , Soluciones Oftálmicas/uso terapéutico , Animales , Glaucoma/tratamiento farmacológico , Masculino , Conejos
7.
J Pharmacol Sci ; 113(2): 153-60, 2010.
Artículo en Inglés | MEDLINE | ID: mdl-20484865

RESUMEN

The present study examined the effect of the nitric oxide (NO) donor NOC18 on lipopolysaccharide (LPS)-induced NO production to investigate a regulation mechanism of NO production by microglial cells. LPS increased the levels of NO and inducible NO synthase (iNOS) protein in BV-2 murine microglial cells in a concentration-dependent manner. Pretreatment with NOC18 for 24 h concentration-dependently attenuated the LPS-induced iNOS protein expression and NO production. The inhibitory effect of NOC18 on LPS-induced NO production was partially blocked by LY83583, a soluble guanylate cyclase inhibitor. Pretreatment with dibutyryl guanosine-3',5'-cyclic monophosphate (DBcGMP), a cell-permeable cGMP analogue, for 24 h attenuated partially LPS-induced iNOS protein expression and NO production. Furthermore, the effects of LPS on iNOS and NO production were inhibited by the c-Jun N-terminal kinase (JNK) inhibitor SP600125, and LPS-induced phosphorylation of JNK and c-Jun was inhibited by NOC18 and DBcGMP. These results suggest that NO production by microglial cells is controlled by a negative feedback mechanism via the NO/cGMP signaling pathway.


Asunto(s)
GMP Cíclico/fisiología , Lipopolisacáridos/farmacología , Microglía/enzimología , Microglía/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico/farmacología , Transducción de Señal/fisiología , Animales , Células Cultivadas , Depresión Química , Relación Dosis-Respuesta a Droga , Ratones , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/biosíntesis
8.
J Obstet Gynaecol Res ; 35(5): 912-7, 2009 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20149041

RESUMEN

AIM: Women at high risk for hereditary breast/ovarian cancer require specific management strategies for cancer prevention and early detection. The authors sought to determine the prevalence of family histories suggestive of a hereditary breast/ovarian cancer syndrome in patients with a personal history of breast or ovarian cancer in Japanese women. METHODS: Family history (first- and second-degree relatives) data were collected by a self-administered questionnaire for women with a history of breast or ovarian cancer in six major cancer treating hospitals in Niigata prefecture, Japan. RESULTS: Data were obtained from 1463 women: 626 women with a history of breast cancer, 289 women with a history of ovarian cancer and 548 women without a history of any cancer as controls. Women with a family history of breast and/or ovarian cancer had OR of breast cancer of 2.3 (95% confidential interval [CI] 1.5-3.7) and ovarian cancer of 2.2 (95% CI 1.3-3.8). The risk was higher when the proband was younger or when two or more relatives were affected. Among women with a history of breast or ovarian cancer, 7.5% met the criteria for a 10% risk of a BRCA1 or BRCA2 mutation according to the Myriad model. CONCLUSION: Obtaining a detailed breast and ovarian cancer family history and the application of the Myriad model is useful for identifying women at an elevated genetic risk of breast and ovarian cancer. The estimation for the prevalence of hereditary breast/ovarian cancer syndrome has significant implications for a patient's management, as well as for the capacity for risk assessment and testing.


Asunto(s)
Neoplasias de la Mama/epidemiología , Síndromes Neoplásicos Hereditarios/epidemiología , Neoplasias Ováricas/epidemiología , Pueblo Asiatico/genética , Neoplasias de la Mama/genética , Estudios de Casos y Controles , Familia , Femenino , Genes BRCA1 , Genes BRCA2 , Asesoramiento Genético , Predisposición Genética a la Enfermedad/genética , Humanos , Japón/epidemiología , Mutación , Síndromes Neoplásicos Hereditarios/genética , Oportunidad Relativa , Neoplasias Ováricas/genética , Vigilancia de la Población , Prevalencia , Riesgo , Medición de Riesgo , Factores de Riesgo , Encuestas y Cuestionarios
9.
Waste Manag ; 29(1): 259-64, 2009 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-18539449

RESUMEN

In this study, we propose a "washing-calcination-conversion of washed fly ash into cement material with bottom ash" (WCCB) system to reduce the amount of fly ash that must be specially treated so it can be used as raw cement material. Calcium hydroxide (Ca(OH)2) is widely used in air-pollution control devices of incinerators while sodium bicarbonate (NaHCO3) is not. We conducted single-, double-, and triple-washing experiments to compare the washing characteristics of two types of fly ash. Unlike NaHCO3 fly ash, Ca(OH)2 fly ash has almost twice as much washed residue and almost 2.5 times more chlorine after the same washing procedure. After washing once, the washing frequency is also important for NaHCO3 fly ash, while the mixing time and liquid/solid ratio are more critical for Ca(OH)2 fly ash. The use of NaHCO3 is more suitable for the WCCB system.


Asunto(s)
Carbono/química , Incineración/instrumentación , Incineración/métodos , Material Particulado/química , Ceniza del Carbón , Materiales de Construcción , Concentración de Iones de Hidrógeno
10.
Chemosphere ; 73(1 Suppl): S78-83, 2008 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-18442842

RESUMEN

Only limited information on the chemical forms of copper in municipal solid waste incinerator (MSWI) fly ash is available in the literature. Therefore, we performed in situ X-ray absorption near-edge spectroscopy (XANES) experiments involving two types of real fly ash to confirm the behavior of copper in fly ash at secondary formation temperatures for polychlorinated dibenzo-p-dioxins (PCDDs) and dibenzofurans (PCDFs). CuCl(2).3Cu(OH)(2) was detected in both fly ash types before heating experiments. Cupric compounds in real fly ash were reduced to cuprous compounds or elemental copper at approximately 200 degrees C. The changes in the Cu XANES spectra observed for the two fly ash samples were similar to those observed previously. We also examined the behavior of copper in model fly ash using SiO(2) to investigate the effect of supporting materials and copper content in fly ash on the dynamic changes of copper and amount of dioxins generated. There was little difference between the use of boron nitride (BN) and SiO(2) as a supporting material. The formation mechanisms of PCDDs and PCDFs in both of the model fly ash types were basically the same. Thus, we conclude that the dynamic change of copper in MSWI fly ash during heating is a commonly observed feature, and no simple relationship between the composition of fly ash and the amount of PCDD/PCDF generated or dynamic change of copper is apparent. The dynamic change of copper explained the generated amount and homologue distribution of PCDDs and PCDFs.


Asunto(s)
Carbono/química , Cobre/química , Dioxinas/química , Material Particulado/química , Absorción , Benzofuranos/química , Ceniza del Carbón , Dibenzofuranos Policlorados , Dibenzodioxinas Policloradas/análogos & derivados , Dibenzodioxinas Policloradas/química , Análisis Espectral , Rayos X
11.
Rev Sci Instrum ; 89(5): 055006, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29864824

RESUMEN

The measurement and control of trace moisture, where the water concentration is lower than 1 ppmv [-76.2 °C for the frost point (°CFP)], are essential for improving the yield rate of semiconductor devices and for ensuring their reliability. A ball surface acoustic wave (SAW) sensor with a sol-gel silica coating exhibited useful characteristics for a trace moisture analyzer (TMA) when the temperature drift of the delay time output was precisely compensated using two-frequency measurement (TFM), where the temperature-compensated relative delay time change (RDTC) was obtained by subtracting the RDTC at the fundamental frequency from that at the third harmonic frequency on an identical propagation path. However, the cost of the measurement circuit was a problem. In this study, a burst waveform undersampling (BUS) circuit based on the theory of undersampling measurement was developed as a practical means. The BUS circuit was useful for precise temperature compensation of the RDTC, and the ball SAW TMA was prototyped by calibrating the RDTC using a TMA based on cavity ring-down spectroscopy (CRDS), which is the most reliable method for trace moisture measurement. The ball SAW TMA outputted a similar concentration to that obtained by the CRDS TMA, and its response time at a set concentration in N2 with a flow rate of 1 l/min was about half that of the CRDS TMA, suggesting that moisture of -80 °CFP was measured within only 1 min. The detection limit at a signal-to-noise ratio of 3 was estimated to be 0.05 ppbv, comparable with that of the CRDS TMA. From these results, it was demonstrated that a practical ball SAW TMA can be realized using the developed BUS circuit.

12.
Chemosphere ; 66(6): 1123-30, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16860372

RESUMEN

Dioxin concentrations from municipal waste incinerators in Japan and elsewhere often show low concentrations that comply with legal limits (in this paper, the term "dioxin" designates WHO-TEQ: PCDD/Fs+dioxin-like PCB). However, such data is usually generated under normal steady state operational conditions, and there has been little investigation of releases occurring during startup and shutdown. It is important, therefore, to ascertain quantitatively emissions in an unsteady state (startup and shutdown) in order to correctly evaluate the relationship between emissions from a facility and the surrounding environment. The present study aimed to examine dioxin emissions of a continuously operated incinerator at startup and shutdown, and estimating the time period of greatest emission, and the processes causing dioxin generation. The startup process was divided into five stages and the shutdown into two; at each stage, dioxins in the flue gas were measured at the boiler outlet and the stack. From the concentration of dioxins and the flue gas volume at each stage, the amount of dioxins at startup and shutdown were calculated, and these were compared with that under steady state conditions. Dioxin concentration at the stack under steady state conditions was a very low level, while those at startup and shutdown were higher. In the case where dioxin concentration under a steady state is a low level like in this study, it is indicated that the total annual dioxin emission from a facility could be attributed to the startup periods.


Asunto(s)
Contaminación del Aire/análisis , Dioxinas/análisis , Incineración/normas , Incineración/métodos
13.
Chemosphere ; 65(2): 183-9, 2006 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-16630644

RESUMEN

The process of destroying polychlorinated biphenyls (PCBs) generates exhaust gases that contain low quantities of PCBs, which cannot be disposed of easily. Activated carbon (AC) can be used to adsorb residual PCBs after disposal of high-level PCBs. We examined the chemical reactivity of AC-supported iron as a catalyst to decompose PCB-153, and varied three decomposition parameters (temperature, time and iron concentration) under an atmosphere of either air or N(2). We measured the Brunauer-Emmett-Teller (BET) surface area and pore volume of AC to assess the adsorption capacity of AC before and after decomposition. At low temperatures the adsorption process was more important than the decomposition process. The decomposition process was completed within 30 and 60 min under air and N(2), respectively. The efficiency of PCB-153 decomposition at 350 degrees C for 120 min was approximately 100.0% and 97.1% under air and N(2), respectively. Analysis of inorganic chloride ions revealed that PCB-153 was effectively destroyed during decomposition. The differences between decomposition under air and N(2) reflected differences in BET surface and pore volume.


Asunto(s)
Contaminantes Atmosféricos/análisis , Carbón Orgánico/química , Monitoreo del Ambiente , Hierro/química , Bifenilos Policlorados/análisis , Adsorción , Cinética , Nitrógeno/química , Porosidad , Volatilización
14.
Artículo en Inglés | MEDLINE | ID: mdl-16615584

RESUMEN

A thin beam of wave usually diverges due to diffraction, which is a limitation of any device using such waves. However, a surface acoustic wave (SAW) on a sphere with an appropriate aperture does not diverge but is naturally collimated, realizing ultramultiple roundtrips along an equator of the sphere. This effect is caused by the balance between diffraction and focusing on a spherical surface, and it enables realization of high-performance ball SAW sensors. The advantage of ball SAW is most fully appreciated when applied to a very thin sensitive film for which the multiple-roundtrip enhances the sensitivity, but the attenuation loss is not very large. It is exemplified in a hydrogen gas sensor that realizes a wide sensing range of 10 ppm to 100% for the first time, and realizes relatively fast response time of 20 s without heating the sensitive film.

15.
J Hazard Mater ; 137(1): 106-12, 2006 Sep 01.
Artículo en Inglés | MEDLINE | ID: mdl-16713083

RESUMEN

Polychlorinated biphenyls (PCBs) and chlorobenzenes (CBzs) are two classes of dioxin precursors formed in municipal solid waste incinerators (MSWIs) producing negative health effects similar to those of dioxins. Reducing the analytical time required for determining the concentrations of these compounds in MSWIs is important for quickly evaluating their importance and associated health risks. In the present study, microwave-assisted extraction (MAE) is compared with traditional Soxhlet extraction (SE) to determine the extraction efficiencies attained for PCB and CBz analysis. The efficiencies of MAE are compared with those of SE under various experimental conditions, using fly ash spiked with standards. Water is used as a safe and environmentally friendly solvent in MAE for PCB and CBz analyses and MAE has high extraction efficiency for spiked fly ash compared with that of SE. Furthermore, the extraction time and organic solvent consumption are reduced with MAE compared with SE. The optimum conditions for MAE established in this study are using a 30-ml volume of toluene/acetone (1/1) or a 15-ml volume of toluene, samples with less than 60% water content (WC), and an irradiation time of 15 min.


Asunto(s)
Carbono/química , Clorobencenos/análisis , Microondas , Material Particulado/química , Bifenilos Policlorados/análisis , Cromatografía de Gases , Ceniza del Carbón , Dioxinas/química , Sustancias Peligrosas , Hidrocarburos Clorados/química , Incineración , Industrias , Espectrometría de Masas , Solventes , Factores de Tiempo , Agua
16.
Eur J Pharmacol ; 787: 43-6, 2016 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-27181069

RESUMEN

To examine the relevance of concentration of benzalkonium chloride (BAK) on the cornea, we investigated the effects of latanoprost containing BAK alone and in combination with other antiglaucoma drug classes on corneal epithelium in vitro in a cultured rabbit corneal cell line (SIRC) and in vivo, using a corneal resistance device (CRD). [In vitro] staten's seruminstitut rabbit corneal cells were exposed to 0.005% latanoprost for 30s, followed by either phosphate buffered saline (control), 0.1% brimonidine, 0.5% timolol, 1% dorzolamide, or 1% brinzolamide. The number of viable cells was counted at 8, 15, and 30min. [In vivo] Albino rabbits were administered one drop of 0.005% latanoprost, followed 5min later by one drop of an agent from the in vitro trial. This was repeated every 15min for a total of three times. The change in corneal barrier function was assessed by measuring the corneal resistance at 2 and 30min after the final administration. [In vitro] At 8min, the viable cell count in the latanoprost+dorzolamide group was significantly lower than in the control group. At 15 and 30min, all treatment groups, except the latanoprost+brimonidine group, demonstrated significantly lower viable cell counts than the control group. [In vivo] At 2min after the final eye drop, the latanoprost+timolol group and the latanoprost+brinzolamide group demonstrated significantly lower corneal resistance than did the latanoprost+brimonidine group. No significant difference was observed between the agents at 30min. In conclusion, when combining latanoprost containing benzalkonium chloride with other classes of antiglaucoma drugs, brimonidine may cause the least corneal damage, and the number of drug administrations may be an important factor.


Asunto(s)
Soluciones Oftálmicas/efectos adversos , Prostaglandinas F Sintéticas/farmacología , Seguridad , Animales , Tartrato de Brimonidina/efectos adversos , Supervivencia Celular/efectos de los fármacos , Impedancia Eléctrica , Epitelio Corneal/citología , Epitelio Corneal/efectos de los fármacos , Presión Intraocular/efectos de los fármacos , Latanoprost , Masculino , Conejos , Sulfonamidas/efectos adversos , Tiazinas/efectos adversos , Tiofenos/efectos adversos , Timolol/efectos adversos
17.
Chemosphere ; 59(10): 1497-505, 2005 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15876392

RESUMEN

A limited amount of information exists regarding the relationship between the chemical form of copper and the formation of chlorinated aromatics in fly ash. To understand the effects of the various forms of copper on the formation of chlorinated aromatics in real fly ash, we determined the chemical forms of copper present in various types of real fly ash using X-ray absorption near edge structure (XANES) and evaluated the relationship between the chemical forms of copper and the formation of chlorinated aromatics. Copper chloride hydroxide (CuCl2 x 3Cu(OH)2) and cuprous chloride (CuCl) were the predominant copper species found in real fly ash. Although pure cupric chloride (CuCl2) is known to be the most active catalyst for the formation of chlorinated aromatics under experimental conditions with synthetic fly ash, CuCl2 was not found in every real fly ash sample. The amount of copper chloride hydroxide was positively correlated with the formation of chlorinated aromatics in real fly ash and is, consequently, considered to be one of the key species involved in the formation of chlorinated aromatics.


Asunto(s)
Contaminantes Ocupacionales del Aire/análisis , Carbono/análisis , Cobre/química , Hidrocarburos Clorados/química , Eliminación de Residuos , Algoritmos , Clorobencenos/química , Ceniza del Carbón , Material Particulado , Espectrometría por Rayos X , Espectrofotometría Atómica
18.
Anal Sci ; 21(7): 769-73, 2005 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-16038492

RESUMEN

Only limited information is available about the behavior of antimony (Sb) in contaminated soils. However, understanding the behavior of Sb in contaminated soils is important, because the toxicity or solubility of this element depends on its chemical state. In this study, we investigated the levels of Sb and the chemical forms of Sb in the soil around a smelter using X-ray absorption fine structure (XAFS) spectra. The highest Sb concentration in the contaminated soil was 2900 mg/kg dry soil. According to Sb-K edge X-ray absorption near edge (XANE) spectra, the Sb in the soil was in the form of Sb(V) compounds. The similarity of extended XAFS (EXAFS) spectra suggests that Sb speciation was independent of the sampling site, which indicates that Sb or Sb2O3 emitted from the smelter was converted into Sb(V) compounds in the soil.

19.
Chemosphere ; 137: 78-86, 2015 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26011415

RESUMEN

The decomposition efficiency of polychlorinated biphenyls (PCBs) was determined using elemental iron (Fe) and three iron (hydr)oxides, i.e., α-Fe2O3, Fe3O4, and α-FeOOH, as catalysts. The experiments were performed using four distinct PCB congeners (PCB-209, PCB-153, and the coplanar PCB-167 and PCB-77) at temperatures ranging from 180 °C to 380 °C and under an inert, oxidizing or reducing atmosphere composed of N2, N2+O2, or N2+H2. From these three options N2 showed to provide the best reaction atmosphere. Among the iron compounds tested, Fe3O4 showed the highest activity for decomposing PCBs. The decomposition efficiencies of PCB-209, PCB-167, PCB-153, and PCB-77 by Fe3O4 in an N2 atmosphere at 230 °C were 88.5%, 82.5%, 69.9%, and 66.4%, respectively. Other inorganic chlorine (Cl) products which were measured by the amount of inorganic Cl ions represented 82.5% and 76.1% of the reaction products, showing that ring cleavage of PCBs was the main elimination process. Moreover, the dechlorination did not require a particular hydrogen donor. We used X-ray photoelectron spectroscopy to analyze the elemental distribution at the catalyst's surface. The O/Fe ratio influenced upon the decomposition efficiency of PCBs: the lower this ratio, the higher the decomposition efficiency. X-ray absorption near edge structure spectra showed that α-Fe2O3 effectively worked as a catalyst, while Fe3O4 and α-FeOOH were consumed as reactants, as their final state is different from their initial state. Finally, a decomposition pathway was postulated in which the Cl atoms in ortho-positions were more difficult to eliminate than those in the para- or meta-positions.


Asunto(s)
Contaminantes Ambientales/química , Compuestos Férricos/química , Halogenación , Hierro/química , Bifenilos Policlorados/química , Catálisis , Temperatura
20.
Mech Ageing Dev ; 124(6): 765-70, 2003 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-12782420

RESUMEN

Mitochondrial DNA 5178 adenine/cytosine (mt5178 A/C) polymorphism is reportedly associated with longevity and susceptibility to age-related diseases in Japanese individuals. We previously reported an association between mt5178 A/C polymorphism and serum protein fraction levels in healthy Japanese women. An association between habitual smoking and serum protein fraction levels has also been reported previously. The aim of this study was to examine whether mt5178 A/C polymorphism influenced the effects of habitual smoking on serum protein fraction levels in 321 healthy Japanese men. In mt5178C genotype men, alpha-1 and alpha-2 globulin levels were higher in smokers than in nonsmokers (P<0.001, and P=0.002, respectively). The influence of smoking on these globulin levels depended on cigarette consumption. However, in mt5178A genotype men, no significant difference was observed in alpha-1 or alpha-2 globulin levels between smokers and nonsmokers. These results suggest that longevity-associated mt5178 A/C polymorphism may influence the effects of cigarette smoking on serum protein fraction levels in healthy Japanese men.


Asunto(s)
ADN Mitocondrial/genética , Longevidad/fisiología , Polimorfismo Genético , Albúmina Sérica/metabolismo , Fumar/sangre , Envejecimiento/fisiología , Genotipo , Globulinas/metabolismo , Humanos , Japón , Masculino , Persona de Mediana Edad , Fumar/genética
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