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Molten salt has been regarded as a versatile and environmental-friendly method for the material preparation and waste destruction. In this work, molten FeCl3 was utilized for the generation of magnetic biochar (MBC) derived from simultaneous activation and magnetization of biomass. The sample characterization indicated that MBC had a rough surface with BET surface area of 404 m2/g and total pore volume of 0.35cm3/g. Highly dispersed Fe3O4 and nitrogen could be deposited on the surface, leading to an excellent magnetization property. The MBC exhibited a great 2,4-Dichlorophenol (2.4-DCP) and atrazine removal performance in solution with the maximum adsorption capacity achieved 298.12 mg/g and 102.17 mg/g. Kinetics results demonstrated that MBC adsorption met the Pseudo-first-order model better. Molten NaOH-Na2CO3 was provided for the re-activation of exhausted MBC. 2,4-DCP was firstly desorbed from the MBC and subsequently destructed by the active species in the melt medium. Chlorine can be captured in the molten alkaline medium from the XRD pattern of residues.The MBC could be easily recovered with a yield of 98.2% and fixed carbon content of 61.0% after the molten salt regeneration process. With no 2,4-DCP detected, 65.5% and 31.69% of initial Cl was found in washing water and residues with the molten NaOH-Na2CO3, respectively. After 4 cycles of regeneration and adsorption, 60.55%-72.22% of initial adsorption capacity can be kept. This preparation and regeneration method can be an effective way to reduce the risk of secondary pollution of chlorinated organic compounds during adsorbent regeneration.Implications: Molten salt (MS) is a salt or multiple salts with a low melting point, and has been applied in many sectors and is regarded as a crucial role in terms of energy, environmental, and resource sustainability. In our paper, magnetic biochar was prepared by one-step activation and magnetization of fir dust using molten FeCl3â6H2O. Meanwhile, a regeneration method using molten alkaline salt was provided. Magnetic biochar generated in our study performed well in the 2,4-dichlorophenol and atrazine adsorption. After four cycles of regeneration and adsorption, 72.2% of initial 2,4-DCP adsorption capacity can be kept.
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Carbón Orgánico/química , Contaminantes Ambientales/análisis , Restauración y Remediación Ambiental/métodos , Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Cloruro de Sodio/química , Congelación , Fenómenos MagnéticosRESUMEN
BACKGROUND/AIMS: Acute rejection (AR) is a major complication post renal transplantation, with no widely-accepted non-invasive biomarker. This study aimed to explore the expression profiles of long non-coding RNAs (lncRNAs) in the peripheral blood (PB) of renal transplant recipients and their potential diagnostic values. METHODS: The genome-wide lncRNA expression profiles were analyzed in 150 PB samples from pediatric and adult renal transplant (PRTx and ARTx) cohorts. The diagnostic performance of differentially expressed lncRNA was determined using receiver operator characteristic curve, with area under the curve (AUC) and 95% confidential interval (CI). Finally, a risk score was constructed with logistical regression model. RESULTS: A total of 162 lncRNAs were found differentially expressed in PRTx cohort, while 163 in ARTx cohort. Among these identified lncRNAs, 23 deregulated accordingly in both cohorts, and could distinguish AR recipients from those without AR. Finally, a risk score with two most significant lncRNAs (AF264622 and AB209021) was generated and exhibited excellent diagnostic performance in both PRTx (AUC:0.829, 95% CI:0.735-0.922) and ARTx cohorts (AUC: 0.889, 95% CI: 0.817-0.960). CONCLUSION: A molecular signature of two lncRNAs in PB could serve as a novel non-invasive biomarker for the diagnosis of AR in both pediatric and adult renal transplant recipients.
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Rechazo de Injerto/patología , Trasplante de Riñón , ARN Largo no Codificante/sangre , Enfermedad Aguda , Área Bajo la Curva , Biomarcadores/sangre , Estudios de Cohortes , Rechazo de Injerto/genética , Rechazo de Injerto/metabolismo , Humanos , Curva ROC , Transcriptoma , Trasplante HomólogoRESUMEN
Background: Clear cell renal cell carcinoma (ccRCC) is the most prevalent histologic subtype of kidney cancers in adults, which could be divided into two distinct subgroups according to the BRCA1 associated protein-1 (BAP1) mutation status. In the current study, we comprehensively analyzed the genome-wide microRNA (miRNA) expression profiles in ccRCC, with the aim to identify the differentially expressed miRNAs between BAP1 mutant and wild-type tumors, and generate a BAP1 mutation-specific miRNA signature for ccRCC patients with wild-type BAP1. Methods: The BAP1 mutation status and miRNA profiles in BAP1 mutant and wild-type tumors were analyzed. Subsequently, the association of the differentially expressed miRNAs with patient survival was examined, and a BAP1 mutation-specific miRNA signature was generated and examined with Kaplan-Meier survival, univariate and multivariate Cox regression analyses. Finally, the bioinformatics methods were adopted for the target prediction of selected miRNAs and functional annotation analyses. Results: A total of 350 treatment-naïve primary ccRCC patients were selected from The Cancer Genome Atlas project, among which 35 (10.0%) subjects carried mutant BAP1 and had a shorter overall survival (OS) time. Furthermore, 33 miRNAs were found to be differentially expressed between BAP1 mutant and wild-type tumors, among which 11 (miR-149, miR-29b-2, miR-182, miR-183, miR-21, miR-365-2, miR-671, miR-365-1, miR-10b, miR-139, and miR-181a-2) were significantly associated with OS in ccRCC patients with wild-type BAP1. Finally, a BAP1 mutation-specific miRNA signature consisting of 11 miRNAs was generated and validated as an independent prognostic parameter. Conclusions: In summary, our study identified a total of 33 miRNAs differentially expressed between BAP1 mutant and wild-type tumors, and generated a BAP1 mutation-specific miRNA signature including eleven miRNAs, which could serve as a novel prognostic biomarker for ccRCC patients with wild-type BAP1.
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Antibiotic resistant genes (ARGs), an emerging contaminant, have been detected worldwide in various environments such as sediments and river. However, little is known about ARGs distribution in landfill. In this study, we investigated five ARGs [sulfonamides resistant genes (sulI and sulII), chloramphenicols resistant gene (cat), ß-lactams resistant gene (bla-SHV), and tetracyclines resistant gene (tetW)] in refuse samples collected from jiangeungou landfill (Xi'an, China) by real-time PCR. We then correlated the ARGs and physiochemical properties of refuse to examine the link between them. Results showed that all tested ARGs have been detected in all samples, suggesting that landfill served as ARGs reservoir. The highest copies numbers of sulII, sulI, tetW, bla-SHV, and cat were (3.70 ± 0.06) x 10(8) copies · g(-1) ( dry refuse), (9.33 · 0.06) x 10(6) copies · g(-1) (dry refuse), (2.27 0.08) x 10(5) copies · g(-1) (dry refuse), (3.68 ± 0.09) x 10(4) copies · g(-1) (dry refuse), and (1.39 ± 0.10) x 10(4) copies · g(-1) (dry refuse), respectively. Further, sulI, sulII, and cat positively correlated to moisture and sulI and cat negatively correlated to pH.
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Farmacorresistencia Microbiana/genética , Genes Bacterianos , Instalaciones de Eliminación de Residuos , Antibacterianos , China , Reacción en Cadena en Tiempo Real de la Polimerasa , beta-Lactamasas/genéticaRESUMEN
Bladder cancer ranks the second most common genitourinary tract cancer, and muscle-invasive bladder cancer (MIBC) accounts for approximately 25 % of all bladder cancer cases with high mortality. In the current study, with a total of 202 treatment-naïve primary MIBC patients identified from The Cancer Genome Atlas dataset, we comprehensively analyzed the genome-wide microRNA (miRNA) expression profiles in MIBC, with the aim to investigate the relationship of miRNA expression with the progression and prognosis of MIBC, and generate a miRNA signature of prognostic capabilities. In the progression-related miRNA profiles, a total of 47, 16, 3, and 84 miRNAs were selected for pathologic T, N, M, and histologic grade, respectively. Of the eight most important progression-related miRNAs, four (let-7c, mir-125b-1, mir-193a, and mir-99a) were significantly associated with survival of patients with MIBC. Finally, a four-miRNA signature was generated and proven as a promising prognostic parameter. In summary, this study identified the specific miRNAs associated with the progression and aggressiveness of MIBC and a four-miRNA signature as a promising prognostic parameter of MIBC.
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Biomarcadores de Tumor/genética , Regulación Neoplásica de la Expresión Génica , MicroARNs/genética , Neoplasias de los Músculos/genética , Neoplasias de los Músculos/mortalidad , Neoplasias de la Vejiga Urinaria/genética , Neoplasias de la Vejiga Urinaria/mortalidad , Anciano , Carcinoma Papilar/genética , Carcinoma Papilar/mortalidad , Carcinoma Papilar/patología , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Perfilación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Neoplasias de los Músculos/patología , Clasificación del Tumor , Invasividad Neoplásica , Estadificación de Neoplasias , Pronóstico , Tasa de Supervivencia , Neoplasias de la Vejiga Urinaria/patologíaRESUMEN
BACKGROUND: Ischemic preconditioning (IPC) could protect against subsequent renal ischemia reperfusion injury (IRI). However, the mechanisms underlying IPC remain far from complete. Hence, we explored the effects of IPC on the renal and systemic hemodynamic changes, renal function and morphology, as well the involvement of endothelial and inducible nitric oxide synthase (eNOS/iNOS), and nitric oxide (NO). METHODS: Male Sprague-Dawley rats were randomly divided into five groups after right-side nephrectomy: Sham group (surgery without vascular clamping); IRI group (the left renal artery was clamped for 45 min); IPC group (pretreated with 15 min of ischemia and 10 min of reperfusion); IPC + vehicle group (administrated with 0.9% saline 5 min before IPC); and IPC + N(G)-nitro-L-arginine methylester (L-NAME) group (pretreated with L-NAME 5 min prior to IPC). The renal and systemic hemodynamic parameters, renal function and morphology, as well as eNOS, iNOS, and NO expression levels in the kidneys were measured at the indicated time points after reperfusion. RESULTS: IPC rats exhibited significant improvements in renal function, morphology, and renal artery blood flow (RABF), without obvious influence on the systemic hemodynamics and renal vein blood flow. Increased eNOS, iNOS, and NO expression levels were detected in the kidneys of IPC rats 24 h after reperfusion. Furthermore, the beneficial effects were fully abolished by the administration of L-NAME. CONCLUSIONS: The results suggest that IPC contributes to early restoration of RABF, probably through eNOS/iNOS-mediated NO production, thereby alleviating the renal dysfunction and histological damage caused by IRI.
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Precondicionamiento Isquémico/métodos , Riñón/irrigación sanguínea , Daño por Reperfusión/fisiopatología , Animales , Hemodinámica/efectos de los fármacos , Hemodinámica/fisiología , Riñón/efectos de los fármacos , Riñón/fisiopatología , Masculino , NG-Nitroarginina Metil Éster/farmacología , Óxido Nítrico/metabolismo , Óxido Nítrico Sintasa de Tipo II/metabolismo , Óxido Nítrico Sintasa de Tipo III/metabolismo , Ratas , Ratas Sprague-Dawley , Daño por Reperfusión/metabolismoRESUMEN
Chromophobe renal cell carcinoma (chRCC) is the third most common subtype of kidney cancers. In the present study, we identified 58 treatment-naïve primary chRCC patients from The Cancer Genome Atlas dataset and analyzed the genome-wide microRNA (miRNA) expression profiles, with the aim to assess the relationship of miRNA expression with the progression and prognosis of chRCC. Overall, a total of 105 miRNAs were found to be differentially expressed between tumor and the adjacent normal tissues from 22 chRCC patients. In the unpaired condition (58 chRCC vs. 22 normal tissues), 77 (96.3%) samples were distinguished correctly by the signatures. In the progression-related profiles, 27 miRNAs were selected for pathologic T and 9 for lymph node involvement. In the survival analyses, the expression levels of mir-191, mir-19a, mir-210, and mir-425 were significantly associated with both recurrence-free survival (RFS) and overall survival, while mir-210 was proven as an independent prognostic factor in terms of RFS. In summary, miRNAs are expressed differentially in chRCC, and unique expression of miRNAs is associated with the progression and prognosis of chRCC.
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Carcinoma de Células Renales/diagnóstico , Carcinoma de Células Renales/genética , Neoplasias Renales/diagnóstico , Neoplasias Renales/genética , MicroARNs/genética , Transcriptoma , Adulto , Anciano , Biomarcadores de Tumor , Carcinoma de Células Renales/mortalidad , Análisis por Conglomerados , Progresión de la Enfermedad , Femenino , Estudios de Seguimiento , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Estimación de Kaplan-Meier , Neoplasias Renales/mortalidad , Masculino , Persona de Mediana Edad , Metástasis de la Neoplasia , Estadificación de Neoplasias , Pronóstico , Carga TumoralRESUMEN
Papillary renal cell carcinoma (pRCC) is the second most prevalent subtype of kidney cancers. In the current study, we analyzed the global microRNA (miRNA) expression profiles in pRCC, with the aim to evaluate the relationship of miRNA expression with the progression and prognosis of pRCC.A total of 163 treatment-naïve primary pRCC patients were identified from the Cancer Genome Atlas dataset and included in this retrospective observational study. The miRNA expression profiles were graded by tumor-node-metastasis information, and compared between histologic subtypes. Furthermore, the training-validation approach was applied to identify miRNAs of prognostic values, with the aid of Kaplan-Meier survival, and univariate and multivariate Cox regression analyses. Finally, the online DAVID (Database for Annotation, Visualization, and Integrated Discover) program was applied for the pathway enrichment analysis with the target genes of prognosis-associated miRNAs, which were predicted by 3 computational algorithms (PicTar, TargetScan, and Miranda).In the progression-related miRNA profiles, 26 miRNAs were selected for pathologic stage, 28 for pathologic T, 16 for lymph node status, 3 for metastasis status, and 32 for histologic types, respectively. In the training stage, the expression levels of 12 miRNAs (mir-134, mir-379, mir-127, mir-452, mir-199a, mir-200c, mir-141, mir-3074, mir-1468, mir-181c, mir-1180, and mir-34a) were significantly associated with patient survival, whereas mir-200c, mir-127, mir-34a, and mir-181c were identified by multivariate Cox regression analyses as potential independent prognostic factors in pRCC. Subsequently, mir-200c, mir-127, and mir-34a were confirmed to be significantly correlated with patient survival in the validation stage. Finally, target gene prediction analysis identified a total of 113 target genes for mir-200c, 37 for mir-127, and 180 for mir-34a, which further generated 15 molecular pathways.Our results identified the specific miRNAs associated with the progression and aggressiveness of pRCC, and 3 miRNAs (mir-200c, mir-127, and mir-34a) as promising prognostic factors of pRCC.
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Carcinoma de Células Renales/diagnóstico , Carcinoma de Células Renales/genética , Neoplasias Renales/diagnóstico , Neoplasias Renales/genética , MicroARNs/biosíntesis , Factores de Edad , Anciano , Progresión de la Enfermedad , Femenino , Perfilación de la Expresión Génica , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Factores SexualesRESUMEN
PURPOSE: Clear cell renal cell carcinoma (ccRCC) is the most common subtype of kidney cancers in adults, and microRNAs (miRNAs) differentially expressed in ccRCC tumors have been identified and proposed to predict prognosis. In the present study, we comprehensively analyzed the genome-wide miRNA expression profiles in ccRCC, with the aim to generate a tumor-specific miRNA signature of prognostic values. METHODS: The miRNA profiles in tumor and the adjacent normal tissue were analyzed, and the association of the differentially expressed miRNAs with patient survival was examined with univariate Cox regression analysis. Finally, a tumor-specific miRNA signature was generated and examined with Kaplan-Meier survival, univariate, and multivariate Cox regression analyses. RESULTS: A total of 147 miRNAs were found differentially expressed between tumor and matched non-tumor tissues from 58 ccRCC patients. The prognostic values of these differentially expressed miRNAs were subsequently analyzed in the 411 ccRCC patients, and 22 miRNAs were found significantly correlated with patient survival. Finally, a tumor-specific miRNA signature of 22 miRNAs was generated and validated as an independent prognostic parameter. CONCLUSIONS: A tumor-specific miRNA signature consisting of 22 miRNAs was identified and validated as an independent prognostic factor, which could serve as a novel biomarker for ccRCC prognostication and help in predicting treatment outcome.
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Carcinoma de Células Renales/genética , Carcinoma de Células Renales/mortalidad , Neoplasias Renales/genética , Neoplasias Renales/mortalidad , MicroARNs/genética , Transcriptoma , Adulto , Anciano , Carcinoma de Células Renales/diagnóstico , Estudios de Cohortes , Femenino , Perfilación de la Expresión Génica , Regulación Neoplásica de la Expresión Génica , Humanos , Neoplasias Renales/diagnóstico , Masculino , Análisis por Micromatrices , Persona de Mediana Edad , Especificidad de Órganos/genética , Pronóstico , Análisis de SupervivenciaRESUMEN
Cr(VI) has been causing serious environmental pollution due to its carcinogenicity, teratogenicity and strong migration. Reduction of Cr( VI) to Cr(III), a precipitation that is much less toxic, is an efficient strategy to control Cr pollution. Within the strategy, bacterial reduction of Cr(VI) to Cr(III) has been considered as one of the best bioremediation methods because of its efficiency, environment friendly, and low cost; however, the molecular mechanism remains large unknown. This review summarizes Cr(VI) reduction bacterial species and its application in pollution control, elaborates the pathways of Cr( VI) reduction and functional proteins involved, concludes the molecular mechanism of baterial reduction Cr(VI), and discusses the orientation of the future research.
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Bacterias/metabolismo , Cromo/química , Contaminación Ambiental/análisis , Biodegradación AmbientalRESUMEN
The phylogenetic analysis of dominant microbial populations in 8-year-old refuse samples was done in terms of the whole Bacterial and Archaeal domains. The results indicated that the Bacterial 16S rRNA genes sequences from the aged refuse were largely affiliated with the genus Bacillus, and that more than 60 % of the Archaeal sequences were closely related to the methanogenic archaeon. Some inferentially identified extremophilic organisms, particularly alkaliphiles and/or halophiles, were noted to be present in the aged refuse. Moreover, molecular evidence for the occurrence of ammonia-oxidizing Archaea in aged refuse was reported, which opens up avenues for elucidating its role in ammonia transformation in landfill systems. It seems reasonable to assume that the highly complex environment within the landfill systems may select for microbial populations with versatile metabolism and strong adaptation. These findings underline the need for further biochemical and ecological study of these organisms in aged refuse.
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Archaea/clasificación , Archaea/aislamiento & purificación , Bacterias/clasificación , Bacterias/aislamiento & purificación , Biodiversidad , Microbiología Ambiental , Residuos , Anciano , Análisis por Conglomerados , ADN de Archaea/química , ADN de Archaea/genética , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Genes de ARNr , Humanos , Filogenia , ARN de Archaea/genética , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido NucleicoRESUMEN
The feasibility of electrolysis integrated with Fe(II)-activated persulfate (S2O8(2-)) oxidation to improve waste activated sludge (WAS) dewaterability was evaluated. The physicochemical properties (sludge volume (SV), total suspended solids (TSS) and volatile suspended solids (VSS)) and extracellular polymeric substances (EPS), including slime EPS, loosely bound EPS (LB-EPS) and tightly bound EPS (TB-EPS) were characterized to identify their exact roles in sludge dewatering. While dewaterability negatively corresponded to LB-EPS, TB-EPS, protein (PN) and polysaccharide (PS) in LB-EPS and TB-EPS, it was independent of SV, TSS, VSS, slime EPS and PN/PS. Further study through scanning electron microscope (SEM) verified the entrapment of bacterial cells by TB-EPS, protecting them against electrolysis disruption. Comparatively, electrolysis integrated with S2O8(2-)/Fe(II) oxidation was able to effectively disrupt the protective barrier and crack the entrapped cells, releasing the water inside EPS and cells. Therefore, the destruction of both TB-EPS and cells is the fundamental reason for the enhanced dewaterability.
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Electrólisis/métodos , Hierro/farmacología , Aguas del Alcantarillado/química , Sulfatos/química , Agua/química , Proteínas Bacterianas/análisis , Biopolímeros/química , Filtración , Floculación/efectos de los fármacos , Microscopía Electrónica de Rastreo , Oxidación-Reducción/efectos de los fármacos , Polisacáridos Bacterianos/metabolismo , Espectrometría por Rayos X , Espectrofotometría Ultravioleta , Factores de Tiempo , Purificación del AguaRESUMEN
About 20 million tonnes of sludge (with 80% moisture content) is discharged by the sewage treatment plants per year in China, which, if not treated properly, can be a significant source of greenhouse gases (GHGs) emissions. Anaerobic digestion is a conventional sewage sludge treatment method and will continue to be one of the main technologies in the following years. This research has taken into consideration GHGs emissions from typical processes of sludge thickening+anaerobic digestion+dewatering+residue land application in China. Fossil CO(2), biogenic CO(2), CH(4,) and avoided CO(2) as the main objects is discussed respectively. The results show that the total CO(2)-eq is about 1133 kg/t DM (including the biogenic CO(2)), while the net CO(2)-eq is about 372 kg/t DM (excluding the biogenic CO(2)). An anaerobic digestion unit as the main GHGs emission source occupies more than 91% CO(2)-eq of the whole process. The use of biogas is important for achieving carbon dioxide emission reductions, which could reach about 24% of the total CO(2)-eq reduction.
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Efecto Invernadero , Aguas del Alcantarillado , Administración de Residuos , Dióxido de Carbono/análisis , ChinaRESUMEN
OBJECTIVE: To investigate the serum levels of sCD44v6 and sE-cadherin (sE-cad) in patients with esophageal squamous cell carcinoma. METHODS: The serum samples were collected from 65 cases of esophageal squamous cell carcinoma, 32 cases of erosive esophagitis and 35 healthy subjects. Serum sCD44v6 and sE-cad levels were measured by enzyme linked immunosorbent assay (ELISA). RESULTS: The mean levels of serum sCD44v6 and sE-cad in esophageal squamous cell carcinoma patients were significantly higher than those of erosive esophagitis patients and normal controls (both P<0.05). There was no significant difference in serum sCD44v6 and sE-cad levels between erosive esophagitis patients normal controls (P=0.566 and P=0.708, respectively). Serum sCD44v6 and sE-cad levels of esophageal cancer patients were not correlated with their clinicopathological features. Serum sCD44v6 level is not correlated with sE-cad level in squamous cell carcinoma patients(P=0.651). CONCLUSION: Serum sCD44v6 and sE-cad might be a potential marker for screening of esophageal squamous cell carcinoma.
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Cadherinas/sangre , Carcinoma de Células Escamosas/sangre , Neoplasias Esofágicas/sangre , Receptores de Hialuranos/sangre , Adulto , Anciano , Anciano de 80 o más Años , Carcinoma de Células Escamosas/patología , Estudios de Casos y Controles , Neoplasias Esofágicas/patología , Femenino , Humanos , Masculino , Persona de Mediana EdadRESUMEN
In this paper, it was comparatively studied about the adsorption or desorption behaviour for Cu2+ or Zn2+ ion onto different landfilled sludge. The results showed that Cu2+ or Zn2+ adsorption isotherm could significantly conform to Freundlich and Henry equations both for the directly landfilled sludge (SSA) and the solidifying landfilled sludge (SSB). Moreover, much higher adsorption capacities were found for Cu2+ on SSA but for Zn2+ on SSB, and the removal efficiency could reach 95% for Cu2+ by SSA with dosage being 10-20 g/L or Zn2+ by SSB with dosage being 5 g/L when the initial CU2+ or Zn2+ concentration was 128 mg/L. However, the desorption ratio of Cu2+, Zn2+ decreased with their increasing adsorption amount, with the same initial concentration, it was much more difficult for Cu2+ to release from SSA while for Zn2+ to release from SSB. Relatively, first-order dynamic equation was the optimal model to describe the kinetics of Cu2+, Zn2+ adsorption by the two sludges, the rates for Cu2+ adsorbed onto SSA and for Zn2+ adsorbed onto SSB were much higher at the same adsorption time. FTIR analysis showed that, the site for Cu2+ adsorption onto SSA is the Si-O group from silicate and carboxy groups from aromatic acids or fatty acids which making stable complex compound with CU2+, while it was specific adsorption by Me--O group from metal oxide and hydroxyl group or carboxy groups from fatty acids for Zn2+ adsorption onto SSB.
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Cobre/química , Eliminación de Residuos/métodos , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Zinc/química , Adsorción , Restauración y Remediación Ambiental , Cinética , Contaminantes Químicos del Agua/aislamiento & purificaciónRESUMEN
The diffusion mechanism of acetylene,which can inhibit the activity of methanogens, was studied. Paraffin wax and rosin were used as matrix of slow-release and calcium carbide was used as inhibition material. Based on the T. Higuchi equation and the characteristics of slow-release inhibitors, a mechanism model was derived. Moreover, the effective diffusion coefficients (De) can be acquired by this model. During the diffusion process, the reaction heat of calcium carbide and water could make acetylene gas expansion and caused the slow-release inhibitors expansion if the hardness of the slow-release inhibitors is inadequate. The hardness and compactness were enhanced and the effective diffusion coefficients reached 2.2849 x 10(-8) cm2/min (R2 = 0.9901) when the mass faction of rosin was 20% and the mass ratio of matrix to calcium carbide was 1/1. Hence,the mitigation the methane generation with municipal solid waste (MSW) can be achieved by the technology of slow-release inhibition.
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Acetileno/análogos & derivados , Acetileno/química , Contaminantes Atmosféricos/antagonistas & inhibidores , Metano/antagonistas & inhibidores , Metano/aislamiento & purificación , Contaminantes Atmosféricos/aislamiento & purificación , Difusión , Restauración y Remediación Ambiental , Cinética , Modelos Químicos , Vaselina/química , Resinas de Plantas/química , Factores de TiempoRESUMEN
Enhancement of semi-aerobic landfill performance through a cowl installed on the gas ventilation pipeline using a simulated landfill box with 2 m x 1 m x 2 m in size was investigated, aiming at the maximum methane emission reduction. Influence of cowl on semi-aerobic environment formation was explored, and variety of methane and carbon dioxide concentrations at different wind speeds and mechanism of cowl operation were identified to provide information on design and improvement of semi-aerobic landfill. The results show that the cowl speeds up the semi-aerobic environment to shape, from over 50 days down to approximately 40 days, and reduces methane emission by promoting methane transformation to carbon dioxide. When the cowl is taken off suddenly during the normal operation, carbon dioxide concentration falls to 15.88% from the initial 16.67% immediately, and methane concentration increases to 16.12% from 6.14%. However, the carbon dioxide and methane concentration becomes 19.18% and 10.05%, respectively, as the cowl is taken on again. Additionally, methane emissions in the exhaust gas were monitored at different wind speeds of 2.0, 3.5, 5.0, 6.5, 8.0 m/s, and finds that the methane concentration reduces from the initial 15% to below 5% when the wind speed increases from 2 m/s to 8 m/s.
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Metano/análisis , Eliminación de Residuos/instrumentación , Eliminación de Residuos/métodos , Aerobiosis , Contaminación del Aire/análisis , Dióxido de Carbono/análisis , Dióxido de Carbono/metabolismo , Metano/metabolismo , Factores de TiempoRESUMEN
Magnesium oxychloride cement (MOC) was used for the stability agent in the stabilization experiments of sewage sludge. It is found that MgCl2 in MOC is a kind of water-absorbent, water absorption of MgCl2 can be achieved at 1.55 mL/g (per 100 g sludge). Meanwhile, some water in sludge can be combined with MOC in the hydration reaction and sludge moisture content can be reduced efficaciously. The crystal structure of 3 phase and 5 phase, which occurred in the hydration process, makes the sludge compressive strength as high as 85.14 kg/cm2. The best ratio of MOC/sludge is 3/100, and MgO/MgCl2 is 3/1. Mg-Si-Al gel system is formed with Si2+, Al3+, Cu2+ in the sludge under alkaline condition, and it plays an important role in the stabilization of the heavy metals in sludge. Leaching experiments of sludge show that heavy metal concentrations of Cu, Zn, Cd, Cr, As in lixivium from sludge are lower than leachability standard.
Asunto(s)
Cloruro de Magnesio/química , Óxido de Magnesio/química , Metales Pesados/química , Aguas del Alcantarillado/química , Eliminación de Residuos Líquidos/métodos , Absorción , Excipientes/químicaRESUMEN
OBJECTIVE: To study clinicopathologic features, treatment and prognosis of pilocytic astrocytoma (PA). METHODS: Histopathological, ultrastructural, immunohistochemical (EnVision method) and clinical features of 68 cases of PA were studied by microscopic investigation with correlation of clinical follow-up information when available. RESULTS: Thirty-five male patients and 33 female patients were studied. The patient's age ranged from 3 to 66 years (mean = 20.1 years). The mean time from symptom onset to surgery was 371 days (range, 3 days to 14 years). Cystic degeneration was noted in 41 cases (60.3%), and enhancement of the tumor was noted in 43 cases (87.8%). On postcontrast imaging examination there were 33 cases involving the cerebellum (48.5%). Total tumor excision was performed in 35 patients, subtotal tumor excision was performed in 31 patients, and the procedures of other 2 patients were not clear. Among 51 patients with follow-up information, 44 were alive, 7 had recurrent tumor, and 7 died. The post-operative survival ranged from 2 months to 124 months (mean survival = 48.1 months). Five years and ten years survival rates were 89%, respectively. Tumors with classic histopathology demonstrated biphasic pattern of growth, consisting of compact elongated bipolar astrocytes associated with rosenthal fibers, and less cellular areas of multipolar cells with granular bodies and microcyst. Some cases showed atypia of nuclei, and occasional mitoses. Involvement of subarachnoid space was seen in 17 cases. One case had anaplastic features. All cases showed diffuse positive staining for GFAP and low expression for Ki-67, except 1 anaplastic tumor with 10% Ki-67 indices. Tumors with subarachnoid space involvement showed positive reticular fiber staining and negative EMA staining. CONCLUSIONS: PA is a benign, WHO grade I tumor with favorable prognosis, and does not require radiotherapy after total resection. The tumor can be mistaken as higher-grade astrocytoma when involving the subarachnoid space, and with cytological atypia, leading to unnecessary radiotherapy after surgery. Recurrence rate is increased when only partial resection is achieved. The outcome for patients with brainstem tumor or anaplastic PA is poor.
Asunto(s)
Astrocitoma/genética , Neoplasias Encefálicas/genética , Proteína Ácida Fibrilar de la Glía/genética , Recurrencia , Astrocitoma/diagnóstico , Neoplasias Encefálicas/diagnóstico , Núcleo Celular/patología , Femenino , Humanos , Masculino , Pronóstico , Resultado del TratamientoRESUMEN
A series of batch tests were conducted to investigate the effects of initial pH on bio-hydrogen production from acid pretreated municipal sludge. The pH of sludge was first adjusted to 2.0, 3.0, 4.0 and 5.0, stood by for 24 h in a refrigerator at 4 degrees C, then adjusted to pH 2.0-12.0 respectively before using as the substrates for batch experiments. The results showed that the acid pretreated sludge with initial pH 11.0 gave the highest hydrogen production, and the corresponding accumulative hydrogen for sludge (dry basis) pretreated at pH 2.0, 3.0, 4.0 and 5.0 were 0.59, 1.83, 0.50 and 0.56 mL/g respectively. Hence, it could be seen that the initial pH 11.0 for the acid pretreated sludge should be the optimum pH range for promoting the growth of dominant hydrogen-producing anaerobes, while inhibiting hydrogen-consuming anaerobes. Meanwhile it also could be concluded that both hydrogenogen and methanogen were inhibited at the initial pH 2.0 to 4.0 and 12.0, which resulted in a low hydrogen production. Although the hydrogenogen and methanogen could be promoted at the initial pH 5.0 to 9.0, the corresponding hydrogen production was still quite low.