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1.
Environ Res ; 245: 118076, 2024 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-38160977

RESUMO

Owing to the ever-increasing generation of plastic waste, the need to develop environmentally friendly disposal methods has increased. This study explored the potential of waste plastic straw to generate valuable light olefins and monocyclic aromatic hydrocarbons (MAHs) via catalytic pyrolysis using high-silica zeolite-based catalysts. HZSM-5 (SiO2/Al2O3:200) exhibited superior performance, yielding more light olefins (49.8 wt%) and a higher MAH content than Hbeta (300). This was attributed to the increased acidity and proper shape selectivity. HZSM-5 displayed better coking resistance (0.7 wt%) than Hbeta (4.4 wt%) by impeding secondary reactions, limiting coke precursor formation. The use of HZSM-5 (80) resulted in higher MAHs and lower light olefins than HZSM-5 (200) because of its higher acidity. Incorporation of Co into HZSM-5 (200) marginally lowered light olefin yield (to 44.0 wt%) while notably enhancing MAH production and boosting propene selectivity within the olefin composition. These observations are attributed to the well-balanced coexistence of Lewis and Brønsted acid sites, which stimulated the carbonium ion mechanism and induced H-transfer, cyclization, Diels-alder, and dehydrogenation reactions. The catalytic pyrolysis of plastic straw over high-silica and metal-loaded HZSM-5 catalysts has been suggested as an efficient and sustainable method for transforming plastic waste materials into valuable light olefins and MAHs.


Assuntos
Hidrocarbonetos Aromáticos , Zeolitas , Dióxido de Silício , Pirólise , Temperatura Alta , Biomassa , Alcenos , Catálise , Hidrocarbonetos
2.
Environ Res ; 246: 118154, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38218520

RESUMO

The management of plastic waste (PW) has become an indispensable worldwide issue because of the enhanced accumulation and environmental impacts of these waste materials. Thermo-catalytic pyrolysis has been proposed as an emerging technology for the valorization of PW into value-added liquid fuels. This review provides a comprehensive investigation of the latest advances in thermo-catalytic pyrolysis of PW for liquid fuel generation, by emphasizing polyethylene, polypropylene, and polystyrene. To this end, the current strategies of PW management are summarized. The various parameters affecting the thermal pyrolysis of PW (e.g., temperature, residence time, heating rate, pyrolysis medium, and plastic type) are discussed, highlighting their significant influence on feed reactivity, product yield, and carbon number distribution of the pyrolysis process. Optimizing these parameters in the pyrolysis process can ensure highly efficient energy recovery from PW. In comparison with non-catalytic PW pyrolysis, catalytic pyrolysis of PW is considered by discussing mechanisms, reaction pathways, and the performance of various catalysts. It is established that the introduction of either acid or base catalysts shifts PW pyrolysis from the conventional free radical mechanism towards the carbonium ion mechanism, altering its kinetics and pathways. This review also provides an overview of PW pyrolysis practicality for scaling up by describing techno-economic challenges and opportunities, environmental considerations, and presenting future outlooks in this field. Overall, via investigation of the recent research findings, this paper offers valuable insights into the potential of thermo-catalytic pyrolysis as an emerging strategy for PW management and the production of liquid fuels, while also highlighting avenues for further exploration and development.


Assuntos
Poliestirenos , Pirólise , Polienos , Polietileno , Plásticos
3.
Environ Res ; 235: 116669, 2023 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-37453506

RESUMO

The global demand for masks has increased significantly owing to COVID-19 and mutated viruses, resulting in a massive amount of mask waste of approximately 490,000 tons per month. Mask waste recycling is challenging because of the composition of multicomponent polymers and iron, which puts them at risk of viral infection. Conventional treatment methods also cause environmental pollution. Gasification is an effective method for processing multicomponent plastics and obtaining syngas for various applications. This study investigated the carbon dioxide gasification and tar removal characteristics of an activated carbon bed using a 1-kg/h laboratory-scale bubble fluidized bed gasifier. The syngas composition was analyzed as 10.52 vol% of hydrogen, 6.18 vol% of carbon monoxide, 12.05 vol% of methane, and 14.44 vol% of hydrocarbons (C2-C3). The results of carbon dioxide gasification with activated carbon showed a tar-reduction efficiency of 49%, carbon conversion efficiency of 45.16%, and cold gas efficiency of 88.92%. This study provides basic data on mask waste carbon dioxide gasification using greenhouse gases as useful product gases.


Assuntos
COVID-19 , Dióxido de Carbono , Humanos , Carvão Vegetal , Máscaras , COVID-19/prevenção & controle , Gases , Biomassa
4.
Fuel (Lond) ; 331: 125720, 2023 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-36033729

RESUMO

Globally, the demand for masks has increased due to the COVID-19 pandemic, resulting in 490,201 tons of waste masks disposed of per month. Since masks are used in places with a high risk of virus infection, waste masks retain the risk of virus contamination. In this study, a 1 kg/h lab-scale (diameter: 0.114 m, height: 1 m) bubbling fluidized bed gasifier was used for steam gasification (temperature: 800 °C, steam/carbon (S/C) ratio: 1.5) of waste masks. The use of a downstream reactor with activated carbon (AC) for tar cracking and the enhancement of hydrogen production was examined. Steam gasification with AC produces syngas with H2, CO, CH4, and CO2 content of 38.89, 6.40, 21.69, and 7.34 vol%, respectively. The lower heating value of the product gas was 29.66 MJ/Nm3 and the cold gas efficiency was 74.55 %. This study showed that steam gasification can be used for the utilization of waste masks and the production of hydrogen-rich gas for further applications.

5.
Nano Lett ; 16(1): 282-8, 2016 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-26694703

RESUMO

Despite the recent considerable progress, the reversibility and cycle life of silicon anodes in lithium-ion batteries are yet to be improved further to meet the commercial standards. The current major industry, instead, adopts silicon monoxide (SiOx, x ≈ 1), as this phase can accommodate the volume change of embedded Si nanodomains via the silicon oxide matrix. However, the poor Coulombic efficiencies (CEs) in the early period of cycling limit the content of SiOx, usually below 10 wt % in a composite electrode with graphite. Here, we introduce a scalable but delicate prelithiation scheme based on electrical shorting with lithium metal foil. The accurate shorting time and voltage monitoring allow a fine-tuning on the degree of prelithiation without lithium plating, to a level that the CEs in the first three cycles reach 94.9%, 95.7%, and 97.2%. The excellent reversibility enables robust full-cell operations in pairing with an emerging nickel-rich layered cathode, Li[Ni0.8Co0.15Al0.05]O2, even at a commercial level of initial areal capacity of 2.4 mAh cm(-2), leading to a full cell energy density 1.5-times as high as that of graphite-LiCoO2 counterpart in terms of the active material weight.

6.
Nano Lett ; 16(11): 7261-7269, 2016 11 09.
Artigo em Inglês | MEDLINE | ID: mdl-27775893

RESUMO

Nanostructured silicon (Si) is useful in many applications and has typically been synthesized by bottom-up colloid-based solution processes or top-down gas phase reactions at high temperatures. These methods, however, suffer from toxic precursors, low yields, and impractical processing conditions (i.e., high pressure). The magnesiothermic reduction of silicon oxide (SiO2) has also been introduced as an alternative method. Here, we demonstrate the reduction of SiO2 by a simple milling process using a lab-scale planetary-ball mill and industry-scale attrition-mill. Moreover, an ignition point where the reduction begins was consistently observed for the milling processes, which could be used to accurately monitor and control the reaction. The complete conversion of rice husk SiO2 to high purity Si was demonstrated, taking advantage of the rice husk's uniform nanoporosity and global availability, using a 5L-scale attrition-mill. The resulting porous Si showed excellent performance as a Li-ion battery anode, retaining 82.8% of the initial capacity of 1466 mAh g-1 after 200 cycles.

7.
BMC Cancer ; 16(1): 724, 2016 09 08.
Artigo em Inglês | MEDLINE | ID: mdl-27609180

RESUMO

BACKGROUND: We previously reported that IL-6 and transglutaminase 2 (TG2) were expressed in more aggressive basal-like breast cancer cells, and TG2 and IL-6 expression gave these cells stem-cell-like phenotypes, increased invasive ability, and increased metastatic potential. In the present study, the underlying mechanism by which IL-6 production is induced in luminal-type breast cancer cells was evaluated, and TG2 overexpression, IL-1ß stimulation, and IL-6 expression were found to give cancerous cells a hormone-independent phenotype. METHODS: Luminal-type breast cancer cells (MCF7 cells) were stably transfected with TG2. To evaluate the requirement for IL-6 neogenesis, MCF7 cells were stimulated with various cytokines. To evaluate tumorigenesis, cancer cells were grown in a three-dimensional culture system and grafted into the mammary fat pads of NOD/scid/IL-2Rγ(-/-) mice. RESULTS: IL-1ß induced IL-6 production in TG2-expressing MCF7 cells through an NF-kB-, PI3K-, and JNK-dependent mechanism. IL-1ß increased stem-cell-like phenotypes, invasiveness, survival in a three-dimensional culture model, and estrogen-independent tumor growth of TG2-expressing MCF7 cells, which was attenuated by either anti-IL-6 or anti-IL-1ß antibody treatment. CONCLUSION: Within the inflammatory tumor microenvironment, IL-1ß increases luminal-type breast cancer cell aggressiveness by stimulating IL-6 production through a TG2-dependent mechanism.


Assuntos
Neoplasias da Mama/patologia , Estrogênios/metabolismo , Proteínas de Ligação ao GTP/genética , Interleucina-1beta/metabolismo , Interleucina-6/metabolismo , Transglutaminases/genética , Animais , Neoplasias da Mama/metabolismo , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Feminino , Proteínas de Ligação ao GTP/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Células MCF-7 , Camundongos , Camundongos Endogâmicos NOD , Invasividade Neoplásica , Proteína 2 Glutamina gama-Glutamiltransferase , Transdução de Sinais , Transglutaminases/metabolismo
8.
Breast Cancer Res Treat ; 154(1): 13-22, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26438141

RESUMO

We aimed to identify the factors affecting the successful tumor engraftment in breast cancer patient-derived xenograft (PDX) models. Further, we investigated the prognostic significance and the functional importance of the PDX engraftment-related genes in triple-negative breast cancers (TNBC). The clinico-pathologic features of 81 breast cancer patients whose tissues were used for PDX transplantation were analyzed to identify the factors affecting the PDX engraftment. A gene signature associated with the PDX engraftment was discovered and its clinical importance was tested in a publicly available dataset and in vitro assays. Nineteen out of 81 (23.4 %) transplanted tumors were successfully engrafted into the PDX models. The engraftment rate was highest in TNBC when compared to other subtypes (p = 0.001) and in recurrent or chemotherapy-resistant tumors compared to newly diagnosed primary tumors (p = 0.024). PDX tumors originated from the TNBC cases showed more rapid tumor growth in mice. Gene expression profiling showed that down-regulation of genes involved in the tumor-immune interaction was significantly associated with the successful PDX engraftment. The engraftment gene signature was associated with worse survival outcome when tested in publicly available mRNA datasets of TNBC cases. Among the engraftment-related genes, PHLDA2, TKT, and P4HA2 showed high expression in triple-negative breast cancer cell lines, and siRNA-based gene silencing resulted in reduced cell invasion and proliferation in vitro. Our results show that the PDX engraftment may reflect the aggressive phenotype in breast cancer. Genes associated with the PDX engraftment may provide a novel prognostic biomarker and therapeutic targets in TNBC.


Assuntos
Proliferação de Células/genética , Prognóstico , Neoplasias de Mama Triplo Negativas/genética , Ensaios Antitumorais Modelo de Xenoenxerto , Animais , Linhagem Celular Tumoral , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Camundongos , Proteínas Nucleares/biossíntese , Proteínas Nucleares/genética , Prolil Hidroxilases/biossíntese , Prolil Hidroxilases/genética , Neoplasias de Mama Triplo Negativas/patologia , Carga Tumoral/genética
9.
Chemosphere ; 350: 141121, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38185423

RESUMO

The use of lignocellulosic waste as an energy source for substituting fossil fuels has attracted lots of attention, and pyrolysis has been established as an effective technology for this purpose. However, the utilization of bio-oil derived from non-catalytic pyrolysis faces certain constraints, making it impractical for direct application in advanced sectors. This study has focused on overcoming these challenges by employing fractional condensation of pyrolytic vapors at distinct temperatures. The potential of five types of sawdust for producing high-quality bio-oil through pyrolysis conducted with a bench-scale bubbling fluidized bed reactor was investigated for the first time. The highest yield of bio-oil (61.94 wt%) was produced using sample 3 (damaged timber). Remarkably, phenolic compounds were majorly gathered in the 1st and 2nd condensers at temperatures of 200 °C and 150 °C, respectively, attributing to their higher boiling points. Whereas, carboxylic acid, ketones, and furans were mainly collected in the 3rd (-5 °C) and 4th (-20 °C) condensers, having high water content in the range of 35.33%-65.09%. The separation of acidic nature compounds such as acetic acid in the 3rd and 4th was evidenced by its low pH in the range of 4-5, while the pH of liquid collected in the 1st and 2nd condensers exhibited higher pH (6-7). The well-separated bio-oil derived from biomass pyrolysis facilitates its wide usage in various applications, proposing a unique approach toward carbon neutrality. In particular, achieving efficient separation of phenolic compounds in bio-oil is important, as these compounds can undergo further upgrading to generate hydrocarbons and diesel fuel.


Assuntos
Temperatura Alta , Polifenóis , Pirólise , Biocombustíveis , Óleos de Plantas , Fenóis/análise , Biomassa
10.
Breast Cancer Res ; 15(5): R79, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-24021059

RESUMO

INTRODUCTION: Tumor cell interactions with the microenvironment, especially those of bone-marrow-derived myeloid cells, are important in various aspects of tumor metastasis. Myeloid-derived suppressor cells (MDSCs) have been suggested to constitute tumor-favoring microenvironments. In this study, we elucidated a novel mechanism by which the MDSCs can mediate spontaneous distant metastasis of breast cancer cells. METHODS: Murine breast cancer cells, 4T1 and EMT6, were orthotopically grafted into the mammary fat pads of syngeneic BALB/c mice. CD11b(+)Gr-1(+) MDSCs in the spleen, liver, lung and primary tumor mass were analyzed. To evaluate the role of MDSCs in the distant metastasis, MDSCs were depleted or reconstituted in tumor-bearing mice. To evaluate whether MDSCs in the metastasizing tumor microenvironment affect breast cancer cell behavior, MDSCs and cancer cells were co-cultivated. To investigate the role of MDSCs in in vivo metastasis, we blocked the interactions between MDSCs and cancer cells. RESULTS: Using a murine breast cancer cell model, we showed that murine breast cancer cells with high IL-6 expression recruited more MDSCs and that the metastasizing capacity of cancer cells paralleled MDSC recruitment in tumor-bearing mice. Metastasizing, but not non-metastasizing, tumor-derived factors induced MDSCs to increase IL-6 production and full activation of recruited MDSCs occurred in the primary tumor site and metastatic organ in the vicinity of metastasizing cancer cells, but not in lymphoid organs. In addition, tumor-expanded MDSCs expressed Adam-family proteases, which facilitated shedding of IL-6 receptor, thereby contributing to breast cancer cell invasiveness and distant metastasis through IL-6 trans-signaling. The critical role of IL-6 trans-signaling was confirmed in both the afferent and efferent pathways of metastasis. CONCLUSION: In this study, we showed that metastasizing cancer cells induced higher MDSCs infiltration and prompted them to secret exaggerated IL-6 as well as soluble IL-6Ra, which, in turn, triggered a persistent increase of pSTAT3 in tumor cells. This potential tumor-MDSC axis involving IL-6 trans-signaling directly affected breast cancer cell aggressiveness, leading to spontaneous metastasis.


Assuntos
Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Subunidade alfa de Receptor de Interleucina-6/metabolismo , Interleucina-6/metabolismo , Células Mieloides/metabolismo , Transdução de Sinais , Animais , Neoplasias da Mama/imunologia , Linhagem Celular Tumoral , Modelos Animais de Doenças , Feminino , Subunidade alfa de Receptor de Interleucina-6/sangue , Camundongos , Células Mieloides/imunologia , Metástase Neoplásica , Fosforilação , Fator de Transcrição STAT3/metabolismo , Carga Tumoral , Microambiente Tumoral/imunologia
11.
Respir Res ; 14: 35, 2013 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-23496815

RESUMO

BACKGROUND: Transglutaminase 2 (TG2) is a post-translational protein-modifying enzyme that catalyzes the transamidation reaction, producing crosslinked or polyaminated proteins. Increased TG2 expression and activity have been reported in various inflammatory conditions, such as rheumatoid arthritis, inflammation-associated pulmonary fibrosis, and autoimmune encephalitis. In particular, TG2 from epithelial cells is important during the initial inflammatory response in the lung. In this study, we evaluated the role of TG2 in the pathogenesis of allergic asthma, particularly whether TG2 affects initial activation signaling leading to Th2 differentiation against antigens. METHODS: We induced allergic asthma by ovalbumin sensitization and intranasal challenge in wild-type (WT) BALB/c and TG2-deficient mice. Broncheoalveolar lavage fluid cells and intracellular cytokine production were analyzed by flow cytometry. Interleukin (IL)-33 and TG2 expression in lung epithelial cells was detected by confocal microscopy. RESULTS: Airway responsiveness was attenuated in TG2-deficient mice compared to that in the WT control. In addition, recruitment of eosinophils and Th2 and Th17 differentiation decreased in TG2-deficient mice. Treatment with cysteamine, a transglutaminase inhibitor, also reduced airway hypersensitivity, inflammatory cell recruitment, and T helper cell differentiation. TG2-deficient mice showed reduced IL-33 expression following induction of allergic asthma compared to those in the WT control. CONCLUSIONS: We found that pulmonary epithelial cells damaged by allergens triggered TG2-mediated IL-33 expression leading to type 2 responses by recruiting both innate and adaptive arms of the immune system.


Assuntos
Alérgenos/imunologia , Asma/imunologia , Proteínas de Ligação ao GTP/metabolismo , Interleucinas/metabolismo , Mucosa Respiratória/imunologia , Células Th2/imunologia , Transglutaminases/metabolismo , Animais , Asma/metabolismo , Asma/patologia , Líquido da Lavagem Broncoalveolar , Feminino , Citometria de Fluxo , Imunofluorescência , Proteínas de Ligação ao GTP/imunologia , Expressão Gênica , Inflamação/imunologia , Inflamação/metabolismo , Inflamação/patologia , Interleucina-33 , Pulmão/citologia , Pulmão/imunologia , Pulmão/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Proteína 2 Glutamina gama-Glutamiltransferase , Mucosa Respiratória/metabolismo , Mucosa Respiratória/patologia , Transdução de Sinais , Células Th2/metabolismo , Transglutaminases/imunologia
12.
Clin Immunol ; 145(2): 122-32, 2012 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23001131

RESUMO

The increased activity of transglutaminase 2 (TG2) in various inflammatory and fibrotic conditions results in the development of numerous disease processes. Experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis, is an inflammatory and demyelinating disease of the central nervous system and is mediated by many inflammatory cytokines and mediators. We examined the role of TG2 in encephalitogenic CD4(+) T cell responses and EAE development using mice lacking TG2 (TG2(-/-)). TG2(-/-) mice showed decreased disease severity as compared with wild-type (WT) mice. Treatment with cysteamine, a TG2 inhibitor, ameliorated disease severity in WT mice. Exacerbated disability in WT mice resulted from the increased infiltration of cytokine-producing CD4(+) T cells and sustained expression of inflammatory cytokines and mediators in the lesion. The increased number of IL-17- and IFN-γ-producing cells in the spinal cord resulted from peripheral expansion of these cells after immunization with myelin-derived antigen. In vitro differentiation of WT and TG2(-/-) splenocytes revealed that proliferation and activation-induced cell death did not differ, but differentiation into IL-17- or IFN-γ-producing cells was increased in WT mice. Adoptive transfer experiments revealed that pathogenic CD4(+) T cell differentiation and disease progression were caused by both the T cell-intrinsic and -extrinsic effects of TG2. This study is the first to report a pathogenic role for TG2 in the EAE progress and suggests that therapeutic targeting of TG2 may be effective against multiple sclerosis.


Assuntos
Linfócitos T CD4-Positivos/efeitos dos fármacos , Encefalomielite Autoimune Experimental/tratamento farmacológico , Proteínas de Ligação ao GTP/antagonistas & inibidores , Inflamação/tratamento farmacológico , Transglutaminases/antagonistas & inibidores , Transferência Adotiva , Animais , Antígenos/imunologia , Antígenos/farmacologia , Linfócitos T CD4-Positivos/enzimologia , Linfócitos T CD4-Positivos/imunologia , Diferenciação Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Movimento Celular/imunologia , Proliferação de Células/efeitos dos fármacos , Cisteamina/farmacologia , Cisteamina/uso terapêutico , Progressão da Doença , Encefalomielite Autoimune Experimental/enzimologia , Encefalomielite Autoimune Experimental/imunologia , Encefalomielite Autoimune Experimental/patologia , Feminino , Proteínas de Ligação ao GTP/deficiência , Proteínas de Ligação ao GTP/genética , Inflamação/enzimologia , Inflamação/imunologia , Inflamação/patologia , Interferon gama/biossíntese , Interferon gama/imunologia , Interleucina-17/biossíntese , Interleucina-17/imunologia , Camundongos , Camundongos Knockout , Bainha de Mielina/imunologia , Proteína 2 Glutamina gama-Glutamiltransferase , Índice de Gravidade de Doença , Transdução de Sinais , Medula Espinal/efeitos dos fármacos , Medula Espinal/enzimologia , Medula Espinal/imunologia , Transglutaminases/deficiência , Transglutaminases/genética
13.
Bioresour Technol ; 361: 127740, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35934249

RESUMO

A sustainable carbon-neutral society is imperative for future generations, and biochars and biofuels are inevitable choice to achieve this goal. Crop residues (CR) such as sugarcane bagasse, corn stover, and rice husk are promising sustainable resources as a feedstock for biochars and biofuels. Extensive research has been conducted on CR-based biochar production not only in environmental remediation areas but also in application for biofuel production. Here, the distribution and resource potential of major crop residues are presented. The production of CR-biochar and its applications in biofuel production processes, focusing on the latest research are discussed. Finally, the challenges and areas of opportunity for future research in terms of CR supply, CR-biochar production, and CR-biochar utilization for biofuel production are proposed. Compared with other literature reviews, this study can serve as a guide for the establishment of sustainable, economical, commercial CR-based biorefineries.


Assuntos
Biocombustíveis , Saccharum , Celulose , Carvão Vegetal/química , Solo/química
14.
Bioresour Technol ; 343: 126109, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34637907

RESUMO

Lignocellulosic biomass is one of the most promising renewable resources and can replace fossil fuels via various biorefinery processes. Through this study, we addressed and analyzed recent advances in the thermochemical conversion of various lignocellulosic biomasses. We summarized the operation conditions and results related to each thermochemical conversion processes such as pyrolysis (torrefaction), hydrothermal treatment, gasification and combustion. This review indicates that using thermochemical conversion processes in biorefineries is techno-economically feasible, easy, and effective compared with biological processes. The challenges experienced in thermochemical conversion processes are also presented in this study for better understanding the future of thermochemical conversion processes for biorefinery. With the aid of artificial intelligence and machine learning, we can reduce time-consumption and experimental work for bio-oil production and syngas production processes.


Assuntos
Inteligência Artificial , Biocombustíveis , Biomassa
15.
J Hazard Mater ; 399: 122949, 2020 11 15.
Artigo em Inglês | MEDLINE | ID: mdl-32502856

RESUMO

Designing nanostructured silicon, such as in the form of nanoparticles, wires, and porous structures, for high-performance Li-ion electrodes, has progressed significantly. These approaches have largely overcome the capacity fading of silicon electrodes from volume expansion during lithiation/de-lithiation. However, they involve high costs, complex processes, and hazardous precursors. Herein, we propose an electrochemical fabrication of silicon nanowires from waste rice husks via a molten salt process based on electrodeoxidation. The addition of NiO as an electric conductor improved the production efficiency and created pores in the nanowires after washing. The electrically produced high-purity silicon yielded high capacity, and the nanowires provided sufficient free volume to accommodate silicon electrode expansion, resulting in improved cycle life. The converted silicon nanowires from the molten salt process will help develop sustainable energy storage materials.

16.
Sci Rep ; 9(1): 8984, 2019 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-31222002

RESUMO

Novel hybrid nanomaterials comprising metal-organic framework compounds carbonised in the presence of biomass material derived from rice husk have been investigated as a new class of sustainable supercapacitor materials for electrochemical energy storage. Specifically, two synthetic routes were employed to grow Co/Mn metal-organic framework compounds in the channels of rice husks, which had been activated previously by heat treatment in air at 400 °C to produce a highly porous network. Pyrolysis of these hybrid materials under nitrogen at 700 °C for 6 h produced metal-containing phases within the nanocarbon, comprising intimate mixtures of Co, MnO and CoMn2O4. The materials thus produced are characterized in detail using a range of physical methods including XRD, electron microscopy and X-ray photoelectron spectroscopy. The synthetic pathway to the metal-organic framework compound is shown to influence significantly the physical properties of the resulting material. Electrochemical evaluation of the materials fabricated revealed that higher specific capacitances were obtained when smaller crystallite sized bimetallic Co/Mn-MOFs were grown inside the rice husks channels compared to larger crystallite sizes. This was in-part due to increased metal oxide loading into the rice husk owing to the smaller crystallite size as well as the increased pseudocapacitance exhibited by the smaller crystallite sizes and increased porosity.

17.
Sci Rep ; 9(1): 6917, 2019 05 06.
Artigo em Inglês | MEDLINE | ID: mdl-31061414

RESUMO

Precise mechanisms underlying interleukin-7 (IL-7)-mediated tumor invasion remain unclear. Thus, we investigated the role of IL-7 in tumor invasiveness using metastatic prostate cancer PC-3 cell line derivatives, and assessed the potential of IL-7 as a clinical target using a Janus kinase (JAK) inhibitor and an IL-7-blocking antibody. We found that IL-7 stimulated wound-healing migration and invasion of PC-3 cells, increased phosphorylation of signal transducer and activator of transcription 5, Akt, and extracellular signal-regulated kinase. On the other hand, a JAK inhibitor and an IL-7-blocking antibody decreased the invasiveness of PC-3 cells. IL-7 increased tumor sphere formation and expression of epithelial-mesenchymal transition (EMT) markers. Importantly, lentiviral delivery of IL-7Rα to PC-3 cells significantly increased bone metastasis in an experimental murine metastasis model compared to controls. The gene expression profile of human prostate cancer cells from The Cancer Genome Atlas revealed that EMT pathways are strongly associated with prostate cancers that highly express both IL-7 and IL-7Rα. Collectively, these data suggest that IL-7 and/or IL-7Rα are promising targets of inhibiting tumor metastasis.


Assuntos
Transição Epitelial-Mesenquimal , Interleucina-7/metabolismo , Neoplasias da Próstata/metabolismo , Neoplasias da Próstata/patologia , Animais , Movimento Celular , Humanos , Masculino , Camundongos , Invasividade Neoplásica , Metástase Neoplásica , Células PC-3 , Receptores de Interleucina-7/metabolismo
18.
Immune Netw ; 15(3): 142-9, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-26140046

RESUMO

Lung fibrosis is a life-threatening disease caused by overt or insidious inflammatory responses. However, the mechanism of tissue injury-induced inflammation and subsequent fibrogenesis remains unclear. Recently, we and other groups reported that Th17 responses play a role in amplification of the inflammatory phase in a murine model induced by bleomycin (BLM). Osteopontin (OPN) is a cytokine and extracellular-matrix-associated signaling molecule. However, whether tissue injury causes inflammation and consequent fibrosis through OPN should be determined. In this study, we observed that BLM-induced lung inflammation and subsequent fibrosis was ameliorated in OPN-deficient mice. OPN was expressed ubiquitously in the lung parenchymal and bone-marrow-derived components and OPN from both components contributed to pathogenesis following BLM intratracheal instillation. Th17 differentiation of CD4(+) αß T cells and IL-17-producing γδ T cells was significantly reduced in OPN-deficient mice compared to WT mice. In addition, Th1 differentiation of CD4(+) αß T cells and the percentage of IFN-γ-producing γδ T cells increased. T helper cell differentiation in vitro revealed that OPN was preferentially upregulated in CD4(+) T cells under Th17 differentiation conditions. OPN expressed in both parenchymal and bone marrow cell components and contributed to BLM-induced lung inflammation and fibrosis by affecting the ratio of pathogenic IL-17/protective IFN-γ T cells.

19.
Exp Mol Med ; 47: e187, 2015 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-26427852

RESUMO

The direct differentiation of hepatocytes from bone marrow cells remains controversial. Several mechanisms, including transdifferentiation and cell fusion, have been proposed for this phenomenon, although direct visualization of the process and the underlying mechanisms have not been reported. In this study, we established an efficient in vitro culture method for differentiation of functioning hepatocytes from murine lineage-negative bone marrow cells. These cells reduced liver damage and incorporated into hepatic parenchyma in two independent hepatic injury models. Our simple and efficient in vitro protocol for endodermal precursor cell survival and expansion enabled us to identify these cells as existing in Sca1(+) subpopulations of lineage-negative bone marrow cells. The endodermal precursor cells followed a sequential developmental pathway that included endodermal cells and hepatocyte precursor cells, which indicates that lineage-negative bone marrow cells contain more diverse multipotent stem cells than considered previously. The presence of equivalent endodermal precursor populations in human bone marrow would facilitate the development of these cells into an effective treatment modality for chronic liver diseases.


Assuntos
Ataxina-1/análise , Células da Medula Óssea/citologia , Hepatócitos/citologia , Animais , Diferenciação Celular , Proliferação de Células , Células Cultivadas , Feminino , Camundongos , Camundongos Endogâmicos BALB C
20.
ACS Nano ; 9(12): 11718-27, 2015 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-26513554

RESUMO

The current diabetes mellitus pandemic constitutes an important global health problem. Reductions in the mass and function of ß-cells contribute to most of the pathophysiology underlying diabetes. Thus, physiological control of blood glucose levels can be adequately restored by replacing functioning ß-cell mass. Sources of functional islets for transplantation are limited, resulting in great interest in the development of alternate sources, and recent progress regarding cell fate change via utilization of extracellular vesicles, also known as exosomes and microvesicles, is notable. Thus, this study investigated the therapeutic capacity of extracellular vesicle-mimetic nanovesicles (NVs) derived from a murine pancreatic ß-cell line. To differentiate insulin-producing cells effectively, a three-dimensional in vivo microenvironment was constructed in which extracellular vesicle-mimetic NVs were applied to subcutaneous Matrigel platforms containing bone marrow (BM) cells in diabetic immunocompromised mice. Long-term control of glucose levels was achieved over 60 days, and differentiation of donor BM cells into insulin-producing cells in the subcutaneous Matrigel platforms, which were composed of islet-like cell clusters with extensive capillary networks, was confirmed along with the expression of key pancreatic ß-cell markers. The resectioning of the subcutaneous Matrigel platforms caused a rebound in blood glucose levels and confirmed the source of functioning ß-cells. Thus, efficient differentiation of therapeutic insulin-producing cells was attained in vivo through the use of extracellular vesicle-mimetic NVs, which maintained physiological glucose levels.


Assuntos
Materiais Biomiméticos/farmacologia , Células da Medula Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Exossomos/química , Insulina/metabolismo , Nanoestruturas/química , Animais , Linfócitos B/citologia , Linfócitos B/efeitos dos fármacos , Linfócitos B/metabolismo , Materiais Biomiméticos/química , Células da Medula Óssea/citologia , Linhagem Celular , Diabetes Mellitus Experimental/metabolismo , Glucose/análise , Glucose/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Células NIH 3T3
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