heterogeneous solid
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2022 ◽  
Vol 10 (1) ◽  
pp. e003633
Author(s):  
Jiemiao Hu ◽  
Qing Yang ◽  
Wendong Zhang ◽  
Hongwei Du ◽  
Yuhui Chen ◽  
...  

BackgroundAdoptive T-cell transfer has become an attractive therapeutic approach for hematological malignancies but shows poor activity against large and heterogeneous solid tumors. Interleukin-12 (IL-12) exhibits potent antitumor efficacy against solid tumors, but its clinical application has been stalled because of toxicity. Here, we aimed to develop a safe approach to IL-12 T-cell therapy for eliminating large solid tumors.MethodsWe generated a cell membrane-anchored IL-12 (aIL12), a tumor-targeted IL-12 (ttIL12), and a cell membrane-anchored and ttIL-12 (attIL12) and a cell membrane-anchored and tumor-targeted ttIL-12 (attIL12) armed T cells, chimeric antigen receptor-T cells, and T cell receptor-T (TCR-T) cells with each. We compared the safety and efficacy of these armed T cells in treating osteosarcoma patient-derived xenograft tumors and mouse melanoma tumors after intravenous infusions of the armed T cells.ResultsattIL12-T cell infusion showed remarkable antitumor efficacy in human and mouse large solid tumor models. Mechanistically, attIL12-T cells targeted tumor cells expressing cell-surface vimentin, enriching effector T cell and interferon γ production in tumors, which in turn stimulates dendritic cell maturation for activating secondary T-cell responses and tumor antigen spreading. Both attIL12- and aIL12-T-cell transfer eliminated peripheral cytokine release and the associated toxic effects.ConclusionsThis novel approach sheds light on the safe application of IL-12-based T-cell therapy for large and heterogeneous solid tumors.


2021 ◽  
Vol 19 ◽  
Author(s):  
Asieh Yahyazadeh ◽  
Motahare Nafei-Kohi ◽  
Esmayeel Abbaspour-Gilandeh ◽  
Mehraneh Aghaei-Hashjin

Abstract: Catalyzed with SCMNPs@CA-EA-SO3H, as a green and heterogeneous solid acid catalyst, 3,4-dihydropyrimidin-2(1H)-one and octahydroquinazolinone derivatives were obtained in high-to-excellent yields and in short reaction times via the one-pot multi-component condensation of ethyl acetoacetate or dimedone, urea, and aldehyde compounds under solvent-free conditions. More importantly, the green catalytic system could be easily collected from the reaction solution utilizing an external magnet and reused for five runs with a negligible decrease in yields and reaction rate.


2021 ◽  
Author(s):  
Ramiro Picoli Nippes ◽  
Paula Derksen Macruz ◽  
Luiza Carla Augusto Molina ◽  
Mara Heloísa Neves Olsen Scaliante

Abstract The synthesis and application of heterogeneous solid catalysts in Fenton-type processes have been shown to be a promising alternative for the removal of hazardous pollutants. In this context, the aim of this study was to prepare and characterize a heterogeneous solid iron catalyst supported on zeolite Y for the degradation of yellow food coloring tartrazine (TY). The catalyst was produced through humid ion exchange and characterized by the physisorption of N2, XRD, SEM, TEM and EDX. The efficiency of the catalyst was evaluated through the degradation of tartrazine yellow dye in a batch regime, and the influence of some of the main operational parameters was also evaluated. The characterizations confirmed the presence of iron on the surface of zeolite Y and the increase in the specific area and pore volume after ion exchange. The catalyst used in the photo-Fenton system was extremely efficient, with a removal of approximately 98% in 120 min in the experimental conditions: [TY]0 = 10 mg/L, [H2O2]0 =200 g/L, Y-Fe dosage=1.5 g/L and pH= 3.0. It was possible to recover the catalyst and use it in five reuse cycles, showing its stability and potential application of this catalyst in heterogeneous photo-Fenton systems.


2021 ◽  
Author(s):  
◽  
Mohammad Al-Zeer

<p>Recent increased environmental awareness and the stimulus of greener chemistry has driven the rapid development of heterogeneous catalysts, particularly solid acids, for a wide range of organic synthesis applications. Typical homogenous acids suffer drastic drawbacks in terms of their corrosivity, toxicity, and reusability, in addition to their separation that generates large amounts of industrial wastes which exceeds in many cases the amount of the formed products.  Crystalline aluminosilicate inorganic polymers (zeolites) have successfully replaced the typical homogenous Lewis acids in many industrially important applications, the majority of which are in the petrochemical industries, e.g. production of olefins and aromatics. The fine chemical industries, however, are more challenging and still mainly use homogenous catalysts. Typical zeolite catalysts are hindered by their restricted micropores, and the low hydrothermal stability of other mesoporous M-silicates (such as MCM-41) results in structural deformation in aqueous solutions at elevated temperatures. Other highly promising solid catalysts suffer drawbacks of high cost, sophisticated synthesis procedures, and environmental risks from the use of toxic reagents. Thus, there is still a need for new cost-efficient reactive heterogeneous solid catalysts that are also environmentally benign.  This thesis reports the development of amorphous aluminosilicate inorganic polymers (known as geopolymers) as a novel class of heterogeneous solid acid catalysts. These geopolymers can be synthesised with the desired acidity and porosity in a very energy-efficient and simple procedure which does not involve lengthy thermal treatments or the use of costly and sometimes toxic structural directing agents that are required for the synthesis of zeolite or other mesoporous aluminosilicates.  Microporous, mesoporous and hierarchical geopolymer-based catalysts were synthesised from different precursors with high surface area and acidic sites (Bronsted and Lewis) generated within their structure by ion-exchange with ammonium ions followed by thermal treatment, allowing the nature of these acidic sites to be tailored to specific applications. Furthermore, some of the resulting geopolymer catalysts were subjected to post synthetic treatments (demetallation) which provided improved acidity and porosity.  In the first instance, the geopolymer-based catalysts were synthesised from a naturally occurring clay mineral and their catalytic performance was evaluated in the industrially important Beckmann rearrangement of cyclohexanone oxime to 𝜀-caprolactam. High catalytic reactivity and selectivity was achieved over the geopolymer-based catalysts that possess high surface area and weak surface acidities consisting of H-bonded silanol nests and vicinal silanols. The catalytic reactivity of the clay-based geopolymer catalysts was further evaluated in the Friedel-Crafts alkylation of large substituted arenes with benzyl halide as alkylating agent, where typical microporous zeolites show poor reactivity due to diffusional limitations. In this reaction, the thermal treatment was adjusted to generate the required Bronsted and Lewis acidic sites. High reactivity was achieved over several mesoporous geopolymer-based catalysts, with the best performance being observed over a hierarchical geopolymer-based catalyst that exhibits the highest acidity of all these new catalysts.  In another approach, highly reactive geopolymer-based catalysts were synthesised from industrial wastes precursors (fly ash). Several fly ashes were collected from different sources and the influence of their chemical and physical properties on the resulting geopolymers was investigated. These fly ash-based catalysts demonstrated excellent catalytic performance in the alkylation of benzene and substituted benzenes and their active sites were ascribed to a combination of Fe2O3 present in the raw fly ash, together with the Bronsted and Lewis acid sites that were generated within the geopolymers framework by the ion-exchange process followed by thermal treatment.  The use of the fly ash-based catalysts was also demonstrated in another highly demanding catalytic process, the Friedel-Crafts acylation of aromatics. High reactivity and selectivity was achieved in the acylation reactions of anisole and mesitylene using benzoylchloride as the acylating agent. In addition to their excellent catalytic reactivities, the fly ash-based geopolymer catalysts provide a valuable approach of the utilisation of industrial wastes such as fly ash, the vast production of which is becoming a world-wide concern.  The geopolymer-based catalysts developed in this work are reusable without significant loss of reactivity and their catalytic performance is superior to other commonly used solid acid catalysts. The results presented in this thesis demonstrate a great potential for geopolymers as active candidates in the field of heterogeneous catalysis, representing as they do a new class of solid acids with highly desirable features such as catalytic efficiency as well as ecological friendliness, cost effectiveness and ease of synthesis.</p>


2021 ◽  
Author(s):  
◽  
Mohammad Al-Zeer

<p>Recent increased environmental awareness and the stimulus of greener chemistry has driven the rapid development of heterogeneous catalysts, particularly solid acids, for a wide range of organic synthesis applications. Typical homogenous acids suffer drastic drawbacks in terms of their corrosivity, toxicity, and reusability, in addition to their separation that generates large amounts of industrial wastes which exceeds in many cases the amount of the formed products.  Crystalline aluminosilicate inorganic polymers (zeolites) have successfully replaced the typical homogenous Lewis acids in many industrially important applications, the majority of which are in the petrochemical industries, e.g. production of olefins and aromatics. The fine chemical industries, however, are more challenging and still mainly use homogenous catalysts. Typical zeolite catalysts are hindered by their restricted micropores, and the low hydrothermal stability of other mesoporous M-silicates (such as MCM-41) results in structural deformation in aqueous solutions at elevated temperatures. Other highly promising solid catalysts suffer drawbacks of high cost, sophisticated synthesis procedures, and environmental risks from the use of toxic reagents. Thus, there is still a need for new cost-efficient reactive heterogeneous solid catalysts that are also environmentally benign.  This thesis reports the development of amorphous aluminosilicate inorganic polymers (known as geopolymers) as a novel class of heterogeneous solid acid catalysts. These geopolymers can be synthesised with the desired acidity and porosity in a very energy-efficient and simple procedure which does not involve lengthy thermal treatments or the use of costly and sometimes toxic structural directing agents that are required for the synthesis of zeolite or other mesoporous aluminosilicates.  Microporous, mesoporous and hierarchical geopolymer-based catalysts were synthesised from different precursors with high surface area and acidic sites (Bronsted and Lewis) generated within their structure by ion-exchange with ammonium ions followed by thermal treatment, allowing the nature of these acidic sites to be tailored to specific applications. Furthermore, some of the resulting geopolymer catalysts were subjected to post synthetic treatments (demetallation) which provided improved acidity and porosity.  In the first instance, the geopolymer-based catalysts were synthesised from a naturally occurring clay mineral and their catalytic performance was evaluated in the industrially important Beckmann rearrangement of cyclohexanone oxime to 𝜀-caprolactam. High catalytic reactivity and selectivity was achieved over the geopolymer-based catalysts that possess high surface area and weak surface acidities consisting of H-bonded silanol nests and vicinal silanols. The catalytic reactivity of the clay-based geopolymer catalysts was further evaluated in the Friedel-Crafts alkylation of large substituted arenes with benzyl halide as alkylating agent, where typical microporous zeolites show poor reactivity due to diffusional limitations. In this reaction, the thermal treatment was adjusted to generate the required Bronsted and Lewis acidic sites. High reactivity was achieved over several mesoporous geopolymer-based catalysts, with the best performance being observed over a hierarchical geopolymer-based catalyst that exhibits the highest acidity of all these new catalysts.  In another approach, highly reactive geopolymer-based catalysts were synthesised from industrial wastes precursors (fly ash). Several fly ashes were collected from different sources and the influence of their chemical and physical properties on the resulting geopolymers was investigated. These fly ash-based catalysts demonstrated excellent catalytic performance in the alkylation of benzene and substituted benzenes and their active sites were ascribed to a combination of Fe2O3 present in the raw fly ash, together with the Bronsted and Lewis acid sites that were generated within the geopolymers framework by the ion-exchange process followed by thermal treatment.  The use of the fly ash-based catalysts was also demonstrated in another highly demanding catalytic process, the Friedel-Crafts acylation of aromatics. High reactivity and selectivity was achieved in the acylation reactions of anisole and mesitylene using benzoylchloride as the acylating agent. In addition to their excellent catalytic reactivities, the fly ash-based geopolymer catalysts provide a valuable approach of the utilisation of industrial wastes such as fly ash, the vast production of which is becoming a world-wide concern.  The geopolymer-based catalysts developed in this work are reusable without significant loss of reactivity and their catalytic performance is superior to other commonly used solid acid catalysts. The results presented in this thesis demonstrate a great potential for geopolymers as active candidates in the field of heterogeneous catalysis, representing as they do a new class of solid acids with highly desirable features such as catalytic efficiency as well as ecological friendliness, cost effectiveness and ease of synthesis.</p>


Cancers ◽  
2021 ◽  
Vol 13 (22) ◽  
pp. 5601
Author(s):  
Viktoria Melcher ◽  
Kornelius Kerl

Pediatric brain tumors are genetically heterogeneous solid neoplasms. With a prevailing poor prognosis and widespread resistance to conventional multimodal therapy, these aggressive tumors are the leading cause of childhood cancer-related deaths worldwide. Advancement in molecular research revealed their unique genetic and epigenetic characteristics and paved the way for more defined prognostication and targeted therapeutic approaches. Furthermore, uncovering the intratumoral metrics on a single-cell level placed non-malignant cell populations such as innate immune cells into the context of tumor manifestation and progression. Targeting immune cells in pediatric brain tumors entails unique challenges but promising opportunities to improve outcome. Herein, we outline the current understanding of the role of the immune regulation in pediatric brain tumors.


Author(s):  
Aderemi Timothy Adeleye ◽  
Kingsley I. John ◽  
Promise Goodness Adeleye ◽  
Amos Adeleke Akande ◽  
Oluwakemi Oluwabunmi Banjoko

2021 ◽  
pp. 108128652110243
Author(s):  
Volodymyr I Kushch ◽  
Igor Sevostianov

The paper focuses on the quantitative characterization of the microstructure of a two-dimensional heterogeneous solid with circular inhomogeneities that may vary from perfectly periodic arrangement to completely random one. This characterization is linked to the calculation of the effective conductivity of the material. The partially disordered system of disks is generated in the framework of the representative unit cell model using Metropolis algorithm. The orientation order metrics are taken as the structural parameters providing a quantitative measure of disorder, and their variation caused by the gradual disordering of the periodic system is assessed. The effective conductivity of the heterogeneous solid with partially disordered microstructure is evaluated by the multipole expansion method. It is shown that effective conductivity cannot be fully characterized by only one orientation order metric, and the required additional ones are identified.


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