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Chongqing Fuling shale gas field, the largest shale gas exploration site in China, produces a large amount of oil-based drill cuttings (OBDC) every year, which is a hazardous waste. Traditional treatment methods such as solidification/stabilization did not recycle the valuable components such as petroleum hydrocarbons. Pyrolysis is proven to be an efficient method that can recover those components. This study firstly investigated the pyrolysis kinetics by two different methods on the basis of detailed material characterization, and then taking the workers and the surrounding ecological environment as the analysis object, the human health risk assessment (HHRA) and ecological risk assessment were evaluated respectively before and after pyrolysis. The results showed that the pyrolysis of OBDC was divided into three stages, and the cracking of light hydrocarbons stage was the key control step for pyrolysis process. The activation energy E increased gradually during the pyrolysis progress. The HHRA results showed that pyrolysis could greatly reduce the non-carcinogenic risk, carcinogenic risk and ecological risk by 59.6 %, 62.8 % and 75 % respectively. However, the carcinogenic risk after pyrolysis was still higher than the critical value 10-6.
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Gas Natural , Petróleo , Humanos , Pirólisis , Aceites , HidrocarburosRESUMEN
The commercial coconut shell-activated carbon was modified to change the number of oxygen-containing functional groups. N2 adsorption/desorption isotherms, Fourier transform infrared (FT-IR), and Boehm titration were adopted to describe the physical and chemical properties of the samples. The adsorption isotherms of CO2 and CH4 on both the unmodified and modified samples were measured. To better understand the effects of surface oxygen-containing functional groups on adsorption of CO2 and CH4, the overall adsorption could be considered as the result of adsorption within the pores and adsorption onto the oxygen-containing functional groups. Thus, a new way to understand different adsorption mechanisms by calculation was proposed. On the basis of the results, there is a significant correlation between the saturation adsorption capacity of CO2 and the number of oxygen-containing functional groups, especially carboxyl and hydroxyl. According to the values of enthalpy (-12.2 to -20 kJ/mol), it can be known that the adsorption caused by oxygen-containing functional groups is exothermic and belongs to physisorption. A semiempirical relationship between the variation of the surface oxygen-functional groups and the variation of the adsorbed amount was established. The method proposed in this paper provides a new way to study the effects of surface functional groups on the adsorption of CO2 and CH4 and can be even promoted in studying the adsorption mechanism of other adsorbates.
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Despite the toxicity of mercury for mammal has been widely studied in recent years, little is known on its impact on the soil microbiome. In this paper, the effects of mercury in soils microbial communities along a gradient of contamination from no to high concentration was assessed by the richness and diversity of microbial community using high throughput sequencing method. The richness of microbial community decreased gradually with the increase of culture time, while the low and medium concentration of mercury had little effect on the evenness of soil microbial community. Proteobacteria tolerated the mercury contamination, while Acidobacteria, Planctomycetes and Chloroflexi were sensitive to mercury pollution in phylum level. Omnitrophica and Ignavibacteriae microorganisms were very sensitive to mercury contamination and dead quickly when contaminated with mercury. Mercury contamination selected two mercury tolerance genuses which were Massilia and Burkholderia in genus level and at least 22 microorganisms such as Alkanindiges, Geothrix, Polycyclovorans and Sporichthya in genus which mainly from the Acidobacteria, Proteobacteria, Bacteroides, Chloroflexi and Omnitrophica phylum were sensitive to mercury. The bacteria tolerant to mercury in soil were Massilia and Burkholderia from Betaproteobacteria and Lysobacter, Luteimonas from Gammaproteobacteria, separately, they were Gram-negative bacteria with thin cell walls and complex ingredients that responded quickly to pollution stress.
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Mercurio/toxicidad , Microbiota/efectos de los fármacos , Microbiología del Suelo , Contaminantes del Suelo/toxicidad , Bacterias/clasificación , Bacterias/efectos de los fármacos , Bacterias/genética , Tolerancia a Medicamentos , Mercurio/análisis , ARN Ribosómico 16S/genética , Suelo , Contaminantes del Suelo/análisis , Especificidad de la Especie , Estrés FisiológicoRESUMEN
The treatment of plants with heavy metals, whether they grow naturally in heavy metal contaminated soil or are used for remediation of heavy metal contaminated soil has attracted increasing attention. Pyrolysis is often used for the disposal of plants with heavy metals because it stabilizes heavy metals effectively and produces biochar. The resulting products of pyrolysis are in the form of solid components (char and ash), liquid components (bio-oil and tar), together with gas components (condensable and non-condensable vapor gas). The metal amount in the char or liquid and gaseous phases can be maximized or minimized via treating a plant feedstock containing heavy metals under different conditions. In addition, the potential risk of biochar produced from plants after pyrolysis becomes a research hotspot in the field of pyrolysis technology of plants containing heavy metals. Herein, we review current literatures that emphasize the influencing factors on the metal content in the biochar, liquid and gaseous phases, as well as the potential risk of biochar.
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Carbón Orgánico/química , Metales Pesados/química , Plantas/metabolismo , Contaminantes del Suelo/química , Biodegradación Ambiental , Carbón Orgánico/toxicidad , Metales Pesados/análisis , Metales Pesados/metabolismo , Pirólisis , Eliminación de Residuos , Contaminantes del Suelo/análisis , Contaminantes del Suelo/metabolismoRESUMEN
The study aimed to determine the biochar yield of four aquatic plants, the leaching toxicity of copper (Cu) and cadmium (Cd) in the biochar, and the stabilization characteristics of the biochar produced under different pyrolysis conditions (at 350⯰C for 1, 2, and 3â¯h and absence/presence of zeolite powder). The results showed that different plant species required a different pyrolysis duration and the presence or absence of zeolite powder. The stabilization of Cu and Cd was significantly affected by the pyrolysis duration and the external materials for different plant species and different types of admixtures. Pyrolysis temperatures over 350⯰C for 1â¯h without zeolite powder generated stable Cu and Cd in goldfish algae (Ceratophyllum demersum L.), foxtail algae (Myriophyllum verticillatum L.), and penny grass (Hydrocotyle vulgaris). Pyrolysis temperatures over 350⯰C for 1â¯h with zeolite powder made Cu and Cd stable in water celery (Oenanthe javanica (Bl.) DC). The addition of zeolite powder during pyrolysis was possible due to the weight reduction efficiency in plants with Cu and Cd. Furthermore, the surface of the biochar with the zeolite powder showed honeycombs and a spongy porous structure. The duration of the pyrolysis had little effect on the honeycomb pore structure.
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Organismos Acuáticos/química , Cadmio/análisis , Carbón Orgánico/química , Cobre/análisis , Pirólisis , Contaminantes Químicos del Agua/análisis , Zeolitas/química , Biomasa , Cadmio/toxicidad , Cobre/toxicidad , Calor , Oenanthe/química , Saxifragales/química , Factores de Tiempo , Contaminantes Químicos del Agua/toxicidadRESUMEN
With the flourish of shale gas industry in China, the characteristic hazardous waste, oil-based drill cuttings (OBDC), was also produced in large quantities. Unlike traditional petroleum industry, shale gas exploitation covers a wider area and there are more well sites, the adverse effects of OBDC piled up around well sites are even greater. This study investigated the pollution status and leaching toxicity of eight heavy metals (Cd, Cr, Cu, Hg, Mn, Ni, Pb and Zn) in OBDC of shale gas exploitation, and evaluated the health risks of the drilling workers. The results showed that heavy metal pollution in OBDC was moderate, and the leaching toxicity was far below the standard value. Non-carcinogenic and carcinogenic risks of drilling workers were within an acceptable range. Meanwhile, in order to reduce the health risks of drilling workers, some suggestions are proposed to reduce the exposure risks of workers and the content of heavy metals in OBDC.
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Contaminación Ambiental/análisis , Residuos Industriales/análisis , Metales Pesados/análisis , Exposición Profesional/análisis , Industria del Petróleo y Gas , Contaminantes del Suelo/análisis , Lluvia Ácida , China , Humanos , Metales Pesados/química , Metales Pesados/toxicidad , Gas Natural , Exposición Profesional/prevención & control , Medición de Riesgo , Contaminantes del Suelo/química , Contaminantes del Suelo/toxicidadRESUMEN
The present study investigated remediation of mercury-contaminated soils using Oxalis corniculata L. combined with various enhancers (sodium thiosulfate, ammonium thiosulfate, ethylenediaminetetraacetic acid and diethylenetriaminepentaacetic acid). The experiment was conducted using Oxalis corniculata seedlings planted in pots containing mercury loaded soils. Investigations included analysis of soil properties, plant growth conditions, ability of the plants to accumulate and extract mercury, and rhizosphere microorganism distribution. The maximal mercury content of the aerial parts and the mercury-translocation ratio of Oxalis corniculata treated with enhancers increased compared to Oxalis corniculata without enhancers. Compared with no enhancers, the theoretical reduction in phytoremediation time was about 50%, 25%, 20% and 21% when Oxalis corniculata was treated with sodium thiosulfate (Na2S2O3), ammonium thiosulfate ((NH4)2S2O3), ethylenediaminetetraacetic acid (EDTA) and diethylenetriaminepentaacetic acid (DTPA), respectively. The results indicated that the dominant species in rhizosphere soils varied with different enhancers. However, the evenness of background soils, rhizosphere soils of Oxalis corniculata, Oxalis corniculata treated with Na2S2O3, (NH4)2S2O3, EDTA and DTPA was not largely different at 0.62, 0.61, 0.57, 0.64, 0.61 and 0.63, respectively. These findings demonstrate that Oxalis corniculata treated with Na2S2O3 has the potential to recover and reclaim mercury-contaminated soils in pots.
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Mercurio/metabolismo , Oxalidaceae/efectos de los fármacos , Rizosfera , Contaminantes del Suelo/metabolismo , Tiosulfatos/farmacología , Biodegradación Ambiental , Ácido Edético/farmacología , Oxalidaceae/crecimiento & desarrollo , Oxalidaceae/metabolismo , Oxalidaceae/microbiología , Ácido Pentético/farmacología , Componentes Aéreos de las Plantas/efectos de los fármacos , Componentes Aéreos de las Plantas/crecimiento & desarrollo , Componentes Aéreos de las Plantas/metabolismo , Desarrollo de la Planta/efectos de los fármacos , Microbiología del SueloRESUMEN
Epstein-Barr virus (EBV) is a ubiquitous human herpesvirus that is linked to the development of various malignancies. There is an urgent need for effective vaccines against EBV. EBV envelope glycoprotein gp350 is an attractive candidate for a prophylactic vaccine. This study was undertaken to produce the truncated (codons 1-443) gp350 protein (gp350(1-443)) in Pichia pastoris and evaluate its immunogenicity. The gp350(1-443) protein was expressed as a secretory protein with an N-terminal His-tag in P. pastoris and purified through Ni-NTA chromatography. Immunization with the recombinant gp350(1-443) could elicit high levels of gp350(1-443)-specific antibodies in mice. Moreover, gp350(1-443)-immunized mice developed strong lymphoproliferative and Th1/Th2 cytokine responses. Furthermore, the recombinant gp350(1-443) could stimulate CD4(+) and CD8(+) T cell responses in vaccinated mice. Collectively, these findings demonstrated that the yeast-expressed gp350(1-443) retained strong immunogenicity. This study will provide a useful source for developing EBV subunit vaccine candidates.
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Infecciones por Virus de Epstein-Barr/virología , Herpesvirus Humano 4/inmunología , Proteínas del Envoltorio Viral/genética , Proteínas del Envoltorio Viral/inmunología , Vacunas Virales/inmunología , Animales , Infecciones por Virus de Epstein-Barr/inmunología , Femenino , Herpesvirus Humano 4/genética , Humanos , Inmunización , Ratones , Ratones Endogámicos BALB C , Células TH1/inmunología , Células Th2/inmunología , Vacunas de Subunidad/administración & dosificación , Vacunas de Subunidad/genética , Vacunas de Subunidad/inmunología , Proteínas del Envoltorio Viral/administración & dosificación , Vacunas Virales/administración & dosificación , Vacunas Virales/genéticaRESUMEN
Oil-based drilling cuttings (OBDCs) contain petroleum hydrocarbons with complex compositions and high concentrations, which have highly carcinogenic, teratogenic, and mutagenic properties. In this study, three highly efficient petroleum hydrocarbon-degrading bacteria were screened from OBDCs of different shale gas wells in Chongqing, China, and identified as Rhodococcus sp. and Dietzia sp. Because of their ability to degrade hydrocarbons of various chain lengths, a new method was proposed for degrading petroleum hydrocarbons in shale gas OBDCs by combining different bacterial species. Results showed that the bacterial consortium, consisting of the three strains, exhibited the highest degradation rate for petroleum hydrocarbons, capable of degrading 74.38% of long-chain alkanes and 93.57% of short-chain alkanes, respectively. Moreover, the petroleum hydrocarbon degradation performance of the bacterial consortium in actual OBDCs could reach 90.60% in the optimal conditions, and the degradation kinetic process followed a first-order kinetic model. This study provides a certain technical reserve for the bioremediation of shale gas OBDCs.
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Ionic cadmium (Cd (II)) in water is a significant threat to ecosystems, the environment, and human health. Research is currently focused on developing efficient adsorption materials to combat Cd (II) pollution in water. One promising solution involves co-pyrolyzing solid residue from anaerobic digestion of food waste with oil-based drill cuttings pyrolysis residue to create a biochar with high organic matter content. This biochar has a lower heavy metal content and leaching toxicity compared to China's national standards, making it both safe and resourceful. It exhibits a high adsorption capacity for Cd (II) in water, reaching up to 47.80 ± 0.37 mg/g. Raising the pyrolysis temperature above 600 °C and increasing the amount of pyrolysis residue beyond 30 % enhances the biochar's adsorption capacity. The adsorption process is primarily driven by mineral precipitation, offering a promising approach for dual waste resource management and reducing heavy metal pollution.
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Cadmio , Carbón Orgánico , Residuos Sólidos , Cadmio/química , Carbón Orgánico/química , Adsorción , Pirólisis , Contaminantes Químicos del Agua/química , Minerales/química , Precipitación Química , Purificación del Agua/métodosRESUMEN
Purpose: Low-grade gliomas (LGG) are common brain tumors with high mortality rates. Cancer cell invasion is a significant factor in tumor metastasis. Novel biomarkers are urgently needed to predict LGG prognosis effectively. Methods: The data for LGG were obtained from the Bioinformatics database. A consensus clustering analysis was performed to identify molecular subtypes linked with invasion in LGG. Differential expression analysis was performed to identify differentially expressed genes (DEGs) between the identified clusters. Enrichment analyses were then conducted to explore the function for DEGs. Prognostic signatures were placed, and their predictive power was assessed. Furthermore, the invasion-related prognostic signature was validated using the CGGA dataset. Subsequently, clinical specimens were procured in order to validate the expression levels of the distinct genes examined in this research, and to further explore the impact of these genes on the glioma cell line LN229 and HS-683. Results: Two invasion-related molecular subtypes of LGG were identified, and we sifted 163 DEGs between them. The enrichment analyses indicated that DEGs are mainly related to pattern specification process. Subsequently, 10 signature genes (IGF2BP2, SRY, CHI3L1, IGF2BP3, MEOX2, ABCC3, HOXC4, OTP, METTL7B, and EMILIN3) were sifted out to construct a risk model. Besides, the survival (OS) in the high-risk group was lower. The performance of the risk model was verified. Furthermore, a highly reliable nomogram was generated. Cellular experiments revealed the ability to promote cell viability, value-addedness, migratory ability, invasive ability, and colony-forming ability of the glioma cell line LN229 and HS-683. The qRT-PCR analysis of clinical glioma samples showed that these 10 genes were expressed at higher levels in high-grade gliomas than in low-grade gliomas, suggesting that these genes are associated with poor prognosis of gliomas. Conclusion: Our study sifted out ten invasion-related biomarkers of LGG, providing a reference for treatments and prognostic prediction in LGG.
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Beryllium-containing sludge (BCS) is a byproduct of the physicochemical treatment of beryllium smelting wastewater. The pollutant element beryllium within BCS is highly unstable and extremely toxic, characterized by its small ionic radius and low charge density, resulting in a high risk of leaching and migration. This study is the first to investigate the leaching behavior, influencing mechanisms, and kinetic processes of beryllium in BCS under various environmental conditions. The results indicate that, under national standard conditions, beryllium exhibits a rapid leaching phase within the first 5 h, which then stabilizes after 10 h, with the total leached content significantly exceeding the leaching toxicity identification standards. Under mildly acidic (pH ≤ 5) or highly alkaline (pH = 14) conditions, beryllium demonstrates pronounced leaching and migration behaviors. Notably, in acidic conditions, the leaching rate exceeds 80% within 5 h. Combining the treatment process of beryllium-containing wastewater with analytical methods such as SEM, XPS, ToF-SIMS, and FTIR, it is revealed that due to the heterogeneous nature of BCS, the particle aggregates dissociate over time under acidic conditions. The particle surfaces become increasingly rough, leading to dissolution and the emergence of more reactive sites, resulting in a high proportion of beryllium leaching. Under these conditions, the gradual reaction of Be(OH)2 in BCS to form soluble Be2+ and its hydrolytic complexes is identified as the primary mechanism for extensive beryllium migration. The process encounters minimal diffusion resistance and is classified as reaction-controlled. In acidic conditions with pH = 4, the leaching rate of beryllium significantly increases with rising temperature. The leaching kinetics equation is [(1-x)-0.44]=e(18.26-53050RT)·t, with an apparent activation energy of 53.05 kJ mol-1.
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Objective: Primary spinal anaplastic ependymoma (PSAE) is an extremely rare disease. We aim to report the largest PSAE cohort, evaluate the treatments, and investigate the prognostic factors for progression-free survival (PFS). Methods: Clinical data collected from the authors' institute and literature articles were pooled and described. Survival analysis and multivariable Cox regression analysis were performed to evaluate therapies and investigate prognostic factors for PFS. Results: Our cohort included 22 females and 16 males, with a median age of 33 years. PSAE developed mostly on cervical and cervicothoracic levels. The median length measured 3 segments. Half of PSAE were intramedullary. Pain was the most common symptom. The median duration of symptoms was 6 months. Neurological statuses were improved in 76% following treatments, whereas clinical tumor progression occurred in 41.7%. The estimated median progression-free survival was 132 months, and the estimated median survival was 192 months. The median Ki-67 index was 15%. Patients aged less than or equal to 25 experienced worse neurological statuses and more repeated progression. Age less than or equal to 25 (HR 10.312, 95%CI 1.535-69.260, p=0.016), gross total resection (HR 0.116, 95%CI 0.020-0.688, p=0.018), and radiotherapy (HR 0.084, 95%CI 0.009-0.804, p=0.032) are three prognostic factors for tumor progression. Conclusion: Tumor progression remains a big concern in the clinical course of PSAE. Being aged above 25, undergoing GTR, and accepting adjuvant radiotherapy put patients at lower risk for tumor progression. Younger patients might have worse neurological statuses compared with those aged over 25.
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The release of highly toxic beryllium in sludge (BCS) produced by physico-chemical treatment of beryllium-containing wastewater from Be smelting production has become a growing concern with the widespread use of Be in the defense industry. This work investigated the potential mobility of Be in BCS. The toxicity characteristic leaching procedure (TCLP) of BCS showed that the amount of leached Be was up to 202 mg L-1, which exceeded the regulated limit by nearly 10,000 times. The chemical fractionation analysis further revealed that the excessive amount of Be leached from BCS was contributed to the high content of acid-soluble fraction and reducible fraction of Be, which accounted for over 70% of the Be content. The results obtained from mineralogical automatic analyzer (MLA) showed that gypsum (23.23%) and epidote (19.55%) were the two major mineralogical phases of BCS. Both were small and loosely structured agglomerated particles with a D50 of 6.61 µm and 3.31 µm. ToF-SIMS results revealed that the Be distribution on the surface of BCS particles was relatively dispersed, with no aggregation or encapsulation. Be co-precipitated with gypsum and chlorite in the form of unstable Be(OH)2, which attached to the surface of these small particles. The unstable state of Be and the small size, loose structure and high liberation of the host material phases are the main reasons for the high leaching mobility of Be. The results of the risk assessment indicated that BCS posed an extremely high potential ecological risk, with Be being the most significant contributor.
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Metales Pesados , Aguas del Alcantarillado , Aguas del Alcantarillado/química , Aguas Residuales , Metales Pesados/análisis , Berilio , Sulfato de CalcioRESUMEN
Background: Primary spinal anaplastic meningioma (PSAM) is a very rare entity in the spinal canal. Therefore, the clinical features, treatment strategy, and long-term outcomes remain poorly studied. Case Description: Clinical data of six patients with PSAM treated at one single institution were retrospectively analyzed and all previously reported cases in the English literature were reviewed. There were three male and three female patients with a median age of 25 years. The duration of symptoms before initial diagnosis ranged from one week to one year. PSAMs occurred at cervical level in four, cervicothoracic in one and thoracolumbar in one. In addition, PSAMs presented isointensity on T1 weighted imaging (WI), hyperintensity on T2WI, and hetero- or homogeneously marked enhancement with contrast. Eight operations were performed in six patients. Simpson II resection was achieved in four (50%), Simpson IV in three (37.5%), Simpson V in one (12.5%). Adjuvant radiotherapy was performed in five patients. With a median survival time of 14 months (4-136 months), three patients had recurrence, two experienced metastases, and four died of respiratory failure. Conclusions: PSAMs are a rare disease, and there is limited evidence as to the management of these lesions. They may metastasize, recur, and portend a poor prognosis. A close follow-up and further investigation are therefore necessary.
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Municipal solid waste incineration (MSWI) fly ash and electrolytic manganese residue (EMR) were classified as hazardous waste, must be harmlessly processed prior to subsequent treatment or disposal. The competition between massive free manganese ions of raw EMR and other heavy metals was found, thus raw EMR was pretreated by calcining to eliminate competition of manganese with other heavy metals for stabilizer complexation. MSWI fly ash was successfully solidified with 6% NaH2PO4, 6% H2NCSNH2 and 20% sintered EMR (800 °C). The addition of sintered EMR enhanced solidification/stabilization of heavy metals in fly ash and the resulting product had a higher compressive strength for further reutilization like trench backfilling, structural fill and void filling. The stabilization/solidification mechanism of heavy metals was attributed to the combined interaction of heavy metal precipitation in stabilizers and ion exchange or physical encapsulation in silicate compounds like calcium silicate, which is a feasible and valuable approach to co-disposal of MSWI fly ash and EMR.
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Metales Pesados , Eliminación de Residuos , Carbono/química , Ceniza del Carbón/química , Residuos Peligrosos , Incineración , Iones , Manganeso , Metales Pesados/análisis , Material Particulado , Eliminación de Residuos/métodos , Residuos Sólidos/análisisRESUMEN
OBJECTIVE: Intramedullary spinal cord metastasis from lung cancer (ISCM-LC) are increasing in prevalence. We aim to investigate its clinical features, treatments and prognosis. METHODS: We reported 6 ISCM-LC cases and conducted a systematic review. Descriptive summarization, survival analysis, and multivariate Cox regression analysis were performed to comprehensively study the disease. RESULTS: All 6 patients had surgery. One used chemotherapy and the other had targeted drugs. Two patients died of ISCM-LC, 1 died of pulmonary embolism, 1 was alive, and 2 were lost to follow-up. We identified 197 ISCM-LC cases in literature with a mean age of 58 years and male preponderance. Small cell lung cancer accounted for 39.1%. The median interval from lung cancer to ISCM-LC was 7 months. Limb weakness was the most common symptom, and 45% cases progressed rapidly. Concomitant brain, leptomeningeal, and vertebral metastasis occurred to 55.8%, 20%, and 19.5%, respectively. Peritumoral edema appeared in 83.3%. Through survival analysis, we found sex, extraspinal metastasis, pathology, and improved symptoms affected the overall survival. Additionally, gross total resection (GTR) shared similar effectiveness with non-GTR, and other treatments following surgery hardly added extra effect. Surgery, improved symptoms, and sex were 3 independent prognostic factors after adjusting for confounding. The estimated median survival time was 5 months. CONCLUSION: The overall survival of ISCM-LC remains poor. Surgery is an independent protective factor for survival. Surgery should be considered once tolerated, and GTR might not be necessary. In addition, female patients with improved symptoms after intervention might have better overall survival.
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Municipal solid waste incineration (MSWI) fly ash and electrolytic manganese residue (EMR) belong to hazardous waste, and must be disposed of before processing. It was found that the low content of silicon and aluminum at low roasting temperature can meet the expansion mechanism of lightweight aggregates. A low-aluminum-silicon lightweight ceramisite was successfully prepared from MSWI fly and EMR, the formation mechanism of which was that the viscosity of molten stuffs in pellet was the function of temperature and chemical composition and had enough capacity of capturing the emerged gas over roasting. The resulting ceramisite met with the requirement of Lytag commercial lightweight aggregate. The content of heavy metal in ceramisite accorded with the requirement of soil environmental quality for development GB 36600-2018 Class I, and PCDD/Fs in ceramisite was 2.0 ng I-TEQ/kg, which was safe. The collaboration of thermal simulation and characterization (SEM-EDS, FTIR and XRD) elaborated the formation mechanism of ceramisite, with six stages provided.
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Metales Pesados , Dibenzodioxinas Policloradas , Eliminación de Residuos , Aluminio , Carbono , Ceniza del Carbón/química , Dibenzofuranos , Residuos Peligrosos , Incineración , Iones , Manganeso , Metales Pesados/análisis , Material Particulado , Silicio , Suelo , Residuos SólidosRESUMEN
In shale gas mining areas, indigenous microorganisms degrade organic pollutants such as petroleum hydrocarbons into carbon dioxide (CO2) and water (H2O) through aerobic metabolism. A large quantity of CO2 emissions will exacerbate the "Greenhouse effect". Based on the clean sieved soil and oil-based drilling fluid in the shale gas mining area, this experiment set three concentration gradients (3523 ± 159 mg/kg, 8715 ± 820 mg/kg and 22,031 ± 1533 mg/kg) to treat the soil, and each group was disposed for the same amount of time (63 days). By analyzing the dynamic changes of microbial diversity and the abundance of key functional genes for carbon fixation, the impact of petroleum hydrocarbons on carbon fixation potential was discovered, and the natural attenuation law of petroleum hydrocarbons in contaminated soil was explored. It provided the scientific research basis of ecology for the carbon cycle, carbon allocation, and carbon fixation in microbial remediation of petroleum hydrocarbon contaminated soil. The results obtained indicated the following: i) The removal rate of petroleum hydrocarbons under high-concentration pollution (45.33 ± 3.90%) was significantly lower than low and medium-concentration pollution. The TPH concentration removal rate of each group was the largest in the early stage of culture (1-5d), and there was no significant correlation between the TPH content and the community composition (R2 = 0.0736, P > 0.05). ii) Composition and function of Carbon Fixation associated microbiota were assessed by 16S rRNA sequencing and PICRUSt (phylogenetic investigation of communities by reconstruction of unobserved states) analysis. The main carbon fixation pathway in this study is the reductive citric acid cycle, because there was no shortage of enzymes that can affect subsequent reactions.
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Gas Natural , Petróleo , Ciclo del Carbono , Dióxido de Carbono , Hidrocarburos , Redes y Vías Metabólicas , Yacimiento de Petróleo y Gas , Filogenia , ARN Ribosómico 16S/genética , SueloRESUMEN
Ultra-high-strength liquor wastewater (UHS-LWW) is rich in organic matter, and the required treatment is expensive. Here, an extremophilic strain Monascus pilosus YX-1125 was isolated for the direct conversion of UHS-LWW to short-chain fatty acids (SCFAs). Strain YX-1125 is an efficient SCFA producer with carbohydrate metabolic flexibility under multiple-stress conditions. Moreover, strain YX-1125 could tolerate up to 75 g/L, 100 g/L, and 50 g/L of ethanol, organic acids, and salt, respectively, without inhibition. In repeated-cycle fermentations, 17.8 g/L of butyric acid and 2.0 g/L of propionic acid were produced from UHS-LWW at the fifth cycle, which are the highest concentrations of wastewater-derived SCFAs reported to date. After SCFA recovery, a 98.9% COD reduction was achieved, which is estimated to reduce treatment costs by 91.7%. Results indicate that M. pilosus YX-1125 is a promising strain for the direct treatment of UHS-LWW, and for converting it into valuable biochemicals without any pre-treatment.