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1.
J Hazard Mater ; 480: 136017, 2024 Sep 30.
Artigo em Inglês | MEDLINE | ID: mdl-39362121

RESUMO

Considering the unexpected nuclear power waste emission and potential nuclear leakage, the exploration of robust materials for the effective capture and storage of radioactive iodine is of great importance but still remains a challenge. In this work, we report the rational synthesis of functionalized NH2-UiO-66-on-ZIF-67 architecture to enhance the static adsorption and retention of volatile iodine. Such MOF-on-MOF heterostructures was fabricated through seeding ZIF-67 core on the surface of NH2-UiO-66 satellite via a facile polyvinylpyrrolidone (PVP) regulated internal extended growth strategies. NH2-UiO-66-on-ZIF-67 exhibited unique core-satellite structure, which significantly promotes the binding interactions with iodine through synergizing of the N-rich imidazole moieties and surface functionalized amino groups within the porosity channels. As a result, the as fabricated NH2-UiO-66-on-ZIF-67 achieves enhanced mass diffusion and high capture capacity of 3600 mg/g for iodine vapor under static sorption conditions. Moreover, water vapor in humid conditions (relative humidity of 18 %) has almost no effect on the static iodine adsorption performance of the material. This study sheds light on a reliable MOF-on-MOF hybrid strategy for effective radioiodine treatment to ensure the safety nuclear waste management.

2.
Eur J Med Chem ; 276: 116729, 2024 Oct 05.
Artigo em Inglês | MEDLINE | ID: mdl-39088998

RESUMO

Soluble transforming growth factor beta receptor 3 (sTGFBR3) antagonist is a new focus in the research and development of Alzheimer's disease (AD) drugs. Our previous studies have identified sTGFBR3 as a promising new target for AD, with few targeted antagonists identified. In this study, we performed structural modeling of sTGFBR3 using AlphaFold2, followed by high-throughput virtual screening and surface plasmon resonance assays. which collectively identified Xanthone as potential compounds for targeting sTGFBR3. After optimizing the sTGFBR3-Xanthone complex using molecular dynamics (MD) simulations, we prepared a series of novel Xanthone derivatives and evaluated their anti-inflammatory activity, toxicity, and structure-activity relationship in BV2 cell model induced by lipopolysaccharides (LPS) or APP/PS1/tau mouse brain extract (BE). Several derivatives with the most potent anti-inflammatory activity were tested for blood-brain barrier permeability and sTGFBR3 affinity. Derivative P24, selected for its superior properties, was further evaluated in vitro. The results indicated that P24 increased the activation of TGF-ß signaling and decreased the activation of IκBα/NF-κB signaling by targeting sTGFBR3, thereby regulating the inflammation-phagocytosis balance in microglia. Moreover, the low acute toxicity, long half-life, and low plasma clearance of P24 suggest that it can be sustained in vivo. This property may render P24 a more effective treatment modality for chronic diseases, particularly AD. The study demonstrates P24 serve as potential novel candidates for the treatment of AD via antagonizing sTGFBR3.


Assuntos
Doença de Alzheimer , Xantonas , Xantonas/química , Xantonas/farmacologia , Xantonas/síntese química , Animais , Humanos , Camundongos , Relação Estrutura-Atividade , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Estrutura Molecular , Descoberta de Drogas , Relação Dose-Resposta a Droga , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/antagonistas & inibidores , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/efeitos dos fármacos , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/química , Anti-Inflamatórios/síntese química , Camundongos Endogâmicos C57BL , Masculino
3.
Nanomaterials (Basel) ; 14(11)2024 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-38869611

RESUMO

Ferroelectric, phase-change, and magnetic materials are considered promising candidates for advanced memory devices. Under the development dilemma of traditional silicon-based memory devices, ferroelectric materials stand out due to their unique polarization properties and diverse manufacturing techniques. On the occasion of the 100th anniversary of the birth of ferroelectricity, scandium-doped aluminum nitride, which is a different wurtzite structure, was reported to be ferroelectric with a larger coercive, remanent polarization, curie temperature, and a more stable ferroelectric phase. The inherent advantages have attracted widespread attention, promising better performance when used as data storage materials and better meeting the needs of the development of the information age. In this paper, we start from the characteristics and development history of ferroelectric materials, mainly focusing on the characteristics, preparation, and applications in memory devices of ferroelectric wurtzite AlScN. It compares and analyzes the unique advantages of AlScN-based memory devices, aiming to lay a theoretical foundation for the development of advanced memory devices in the future.

4.
Chemosphere ; 362: 142676, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38936487

RESUMO

A MOF-on-MOF composite derivative material named ZIF-67@Ce-MOF-600 was designed and synthesized. The preparation of ZIF-67@Ce-MOF-600 was optimized from the aspects of the ratio of metal and ligand, heat-treatment temperature. It was demonstrated by XRD, FT-IR, SEM-EDS and TEM. The optimum conditions for the activation of PMS by ZIF-67@Ce-MOF-600 for the degradation of tetracycline (TC) were investigated by adjusting the catalyst dosage, TC, pH, peoxymonosulfate (PMS) concentration, and different kinds of water, co-existing anions and pollution. Under optimal conditions (20 mg catalysts and 50 mg PMS added) in 100 mL of tetracyclines (TC) solvent (20 mg TC/L), the removal rate could reach up to 99.2% and after five cycles was 70.5%. The EPR results indicated the presence of free radicals and non-free radical, among which free radicals intended to play a major role in the degradation process. Its possible degradation pathways and attack sites were analyzed by liquid-phase mass spectrometry and DFT analysis.


Assuntos
Estruturas Metalorgânicas , Peróxidos , Tetraciclina , Poluentes Químicos da Água , Estruturas Metalorgânicas/química , Poluentes Químicos da Água/química , Tetraciclina/química , Peróxidos/química , Purificação da Água/métodos , Catálise , Água/química
5.
Toxics ; 12(5)2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38787129

RESUMO

Zirconium is recognized as one of the main impurities of the rare earth element scandium during purification. It presents significant challenges due to its similar chemical properties, making separating it difficult. This study used trialkyl phosphine oxide (TRPO) as a functional ligand, and the effects of carrier type and acidity on adsorption performance were first investigated. Among these, the novel extraction resin SiO2-P as a carrier for TRPO demonstrated more prominent separation performance in 0.2 M H2SO4 and 5 M HCl solutions. The kinetic and isotherm data were consistent with the pseudo-secondary kinetics and Langmuir model, respectively, and the adsorption process could be regarded as homogeneous monolayer adsorption subject to the dual effects of chemisorption and internal diffusion. In addition, thermodynamic analysis showed that the adsorption process of zirconium under the experimental conditions was a spontaneous endothermic process. Combined with the results of SEM-EDS, FT-IR, and XPS analyses, scandium and zirconium were successfully adsorbed by the resin and uniformly distributed on its surface, and the greater affinity of the P=O groups on the resin for zirconium was the critical factor contributing to the separation of scandium and zirconium. Finally, scandium and zirconium in sulfuric acid and hydrochloric acid media were extracted and separated by column experiments, and the purity of scandium could reach 99.8% and 99.99%, respectively.

6.
J Hazard Mater ; 471: 134431, 2024 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-38691936

RESUMO

To promote the environmentally friendly and sustainable development of nuclear energy, it is imperative to address the treatment of wastewater generated by the nuclear industry. This necessitates the enhancement of fission product reclamation efficiency post-treatment. This study aims to combine defect control and confined self-assembly strategies for the precise design of interlayer spacing (14.6 Å to 15.1 Å), leading to the fabrication of conditional natroxalate-functionalized vanadosilicate, and its potential application in the efficient adsorption and reclamation of 90Sr. Na0.03Natroxalate2.47Si1.44Nb0.08V1.92O5·1.2 H2O (Nb4-NxSiVO), with a layer spacing of 14.9 Å, exhibits the highest Sr(II) adsorption capacity (248.76 mg/g), enabling effective separation with Cs+. The natroxalate embedded within the confined interlayers demonstrates excellent stability, offering rapid (within 10 min) and stable adsorption sites for Sr(II). Furthermore, Nb4-NxSiVO exhibits a wide band gap and exceptional thermal stability before and after adsorption, rendering hard desorption of 90Sr. The findings highlight the potential of Nb4-NxSiVO as a promising adsorbent for rapid and selective purification of 90Sr-containing wastewater and further application in nuclear batteries.

7.
Breast Cancer ; 31(3): 426-439, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38472737

RESUMO

Enhancing radiotherapy sensitivity is crucial for improving treatment outcomes in triple-negative breast cancer (TNBC) patients. In this study, we investigated the potential of targeting Elongin B (ELOB) to enhance radiotherapy efficacy in TNBC. Analysis of TNBC patient cohorts revealed a significant association between high ELOB expression and poor prognosis in patients who received radiation therapy. Mechanistically, we found that ELOB plays a pivotal role in regulating mitochondrial function via modulating mitochondrial DNA expression and activities of respiratory chain complexes. Targeting ELOB effectively modulated mitochondrial function, leading to enhanced radiosensitivity in TNBC cells. Our findings highlight the importance of ELOB as a potential therapeutic target for improving radiotherapy outcomes in TNBC. Further exploration of ELOB's role in enhancing radiotherapy efficacy may provide valuable insights for developing novel treatment strategies for TNBC patients.


Assuntos
Tolerância a Radiação , Neoplasias de Mama Triplo Negativas , Feminino , Humanos , DNA Mitocondrial/genética , Regulação Neoplásica da Expressão Gênica/efeitos da radiação , Mitocôndrias/efeitos da radiação , Mitocôndrias/metabolismo , Prognóstico , Fatores de Transcrição/metabolismo , Neoplasias de Mama Triplo Negativas/radioterapia , Neoplasias de Mama Triplo Negativas/patologia
8.
J Environ Manage ; 353: 120283, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38330842

RESUMO

The recovery of rare earth elements (REEs) including neodymium (Nd) and dysprosium (Dy) from NdFeB permanent magnets has become one of the main ways to solve the increased demand for rare earth. Herein, n-dodecyl phosphate (DPPA) was used for the first time as the adsorption functional group donor, sodium alginate as the substrate, and calcium chloride solution as the reactive solvent, a hybrid hydrogel adsorbent DPPA/CaALG was synthesized by sol-gel method for application in the adsorption and separation of Nd and Dy from the Co-Nd-Dy ternary system. SEM-EDS, and N2 adsorption-desorption analysis showed the successful preparation of DDPA/CaALG with mesoporous structure. Batch experiments showed the superiority of the hybrid hydrogel for the good selective adsorption of Nd and Dy, such as large adsorption capacity (Nd: 162.5 mg/g, Dy: 183.5 mg/g), and no adsorption for Co. FT-IR, XPS showed that PO and P-O groups are involved in the adsorption process of Nd and Dy as electron acceptors, where the ion exchange of P-OH is dominant. Furthermore, the chemical properties of ligands and complexes were analyzed by Density Functional Theory (DFT) calculations and revealed their adsorption behaviors as well as the competition between different metal ions.


Assuntos
Metais Terras Raras , Neodímio , Disprósio , Hidrogéis , Adsorção , Alginatos , Espectroscopia de Infravermelho com Transformada de Fourier , Fosfatos
9.
Inorg Chem ; 63(8): 3859-3869, 2024 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-38335061

RESUMO

During the PUREX process, the separation between U(VI) and Pu(IV) is achieved by reducing Pu(IV) to Pu(III), which is complicated and energy-consuming. To address this issue, we report here the first case of separation of U(VI) from Pu(IV) by o-phenanthroline diamide ligands under high acidity. Two new o-phenanthroline diamide ligands (1,10-phenanthroline-2,9-diyl)bis(indolin-1-ylmethanone) (L1) and (1,10-phenanthroline-2,9-diyl)bis((2-methylindolin-1-yl)methanone) (L2) were synthesized, which can effectively separate U(VI) from Pu(IV) even at 4 mol/L HNO3. The highest separation factor of U(VI) and Pu(IV) can reach over 1000, setting a new record for the separation of U(VI) from Pu(IV) under high acidity. Furthermore, extracted U(VI) can be easily recovered with water or dilute nitric acid, and the extraction performance remains stable even after 150 kGy gamma irradiation, which provides solid experimental support for potential engineering applications. The results of UV-vis titration and single-crystal X-ray diffraction measurements show that the 1:1 complex formed by L1 with U(VI) is more stable than all of the previously reported phenanthroline ligands, which reasonably reveals that the ligand L1 designed in this work has excellent affinity for U(VI). The findings of this work promise to contribute to the facilitation of the PUREX process by avoiding the use of reducing agents. It also provides new clues for designing ligands to achieve efficient separation between U(VI) and Pu(IV) at high acidity.

10.
Exp Anim ; 73(2): 211-222, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38199255

RESUMO

C-C chemokine receptor type 2 (CCR2) is a monocyte chemokine associated with oxidative stress and inflammation. Kidney stones (KS) are composed of calcium oxalate (CaOx), which trigger renal oxidative stress and inflammatory. This study aims to evaluate the effects of CCR2 on KS in vivo and in vitro. Eight-week-old male C57BL/6J mice were intraperitoneally injected with glyoxylate (GOX) daily to establish a KS model, and along with CCR2 antagonist (INCB3344) treatment on days 2, 4, and 6. The results showed that CCR2 antagonist reduced renal injury markers (blood urea nitrogen and serum creatinine), alleviated renal tubular injury and CaOx crystal deposition. CCR2 antagonist also decreased CCR2 expression induced by GOX treatment and increased Nrf2 expression. GOX treatment promoted malondialdehyde (MDA) production, decreased glutathione (GSH) content, and inhibited catalase (CAT) and superoxide dismutase (SOD) activity, however, CCR2 antagonist attenuated the above effects of GOX. CCR2 antagonist had inhibitory effects on GOX-induced inflammatory cytokine expression (IL1B, IL6 and MCP1), and inhibited apoptosis by increasing Bcl-2 expression and decreasing Bax and cleaved-caspase 3 expression. In vitro experiments were performed by co-culture model of CaOx-induced damaged HK-2 cells and macrophage-like THP-1 cells. CCR2 antagonist inhibited CaOx-induced THP-1 cell M1 polarization by decreasing the TNF-α, IL6 and iNOS levels, and further alleviated CaOx-induced oxidative stress damage, inflammatory response and apoptosis of HK-2 cells. The study suggests that CCR2 antagonist may be resistant to CaOx crystals-induced oxidative stress and inflammation by inhibiting macrophage M1 polarization.


Assuntos
Oxalato de Cálcio , Inflamação , Ativação de Macrófagos , Camundongos Endogâmicos C57BL , Estresse Oxidativo , Pirrolidinas , Receptores CCR2 , Animais , Estresse Oxidativo/efeitos dos fármacos , Masculino , Receptores CCR2/metabolismo , Receptores CCR2/antagonistas & inibidores , Oxalato de Cálcio/metabolismo , Ativação de Macrófagos/efeitos dos fármacos , Camundongos , Cálculos Renais/induzido quimicamente , Cálculos Renais/prevenção & controle , Rim/metabolismo , Rim/efeitos dos fármacos , Humanos , Modelos Animais de Doenças
11.
Langmuir ; 40(1): 413-425, 2024 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-38133590

RESUMO

The adsorption of organic polymers onto the surface of graphene oxide is known to improve its dispersibility in cement-based materials. However, the mechanism of this improvement at the atomic level is not yet fully understood. In this study, we employ a combination of DFT static calculation and umbrella sampling to explore the reactivity of polymers and investigate the effects of varying amounts of phenyl groups on their adsorption capacity on the surface of graphene oxide. Quantitative analysis is utilized to study the structural reconstruction and charge transfer caused by polymers from multiple perspectives. The interfacial reaction between the polymer and graphene oxide surface is further clarified, indicating that the adsorption process is promoted by hydrogen bond interactions and π-π stacking effects. This study sheds light on the adsorption mechanism of polymer-graphene oxide systems and has important implications for the design of more effective graphene oxide dispersants at the atomic level.

12.
Small ; : e2307304, 2023 Dec 06.
Artigo em Inglês | MEDLINE | ID: mdl-38054780

RESUMO

The construction of heterojunction photocatalysts is an auspicious approach for enhancing the photocatalytic performance of wastewater treatment. Here, a novel CeO2 /Bi2 WO6 heterojunction is synthesized using an in situ liquid-phase method. The optimal 15% CeO2 /Bi2 WO6 (CBW-15) is found to have the highest photocatalytic activity, achieving a degradation efficiency of 99.21% for tetracycline (TC), 98.43% for Rhodamine B (RhB), and 94.03% for methylene blue (MB). The TC removal rate remained at 95.38% even after five cycles. Through active species capture experiments, •O2 - , h+ , and •OH are the main active substances for TC, RhB, and MB, respectively. The possible degradation pathways for TC are analyzed using liquid chromatography-mass spectrometry (LC-MS). The photoinduced charge transfer and possible degradation mechanisms are proposed through experimentation and density functional theory (DFT) calculations. Toxicity assessment experiments show a significant reduction in toxicity during the TC degradation process. This study uncovers the mechanism of photocatalytic degradation in CeO2 /Bi2 WO6 and provides new insights into toxicity assessment.

13.
Toxics ; 11(12)2023 Nov 23.
Artigo em Inglês | MEDLINE | ID: mdl-38133355

RESUMO

Over the past few decades, with the rapid growth of the global population and economy, the increasing levels of various pollutants such as heavy metals, radionuclides, and organic/inorganic/biological toxins from various industries and human activities, which diffuse into aspects of the environment such as the atmosphere, soil, and natural water, have posed a serious threat to human health and the environment [...].

14.
Phys Chem Chem Phys ; 25(44): 30349-30360, 2023 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-37909263

RESUMO

Calcium ion, as an essential component in CASH, affects the aggregation and formation process of CASH, thereby influencing its microstructure and mechanical properties. However, the mechanism by which calcium ions affect the polymerization process of CASH is not yet fully understood. In this study, the effects of calcium ions on the polymerization process, coagulation state, and microstructure of CASH are investigated via molecular dynamics simulation. The results indicate that the presence of a trace amount of Ca2+ attracts oligomers towards the calcium-rich region, thus speeding up the polymerization to some extent, but as the Ca2+ content increases, more Ca2+ binds to the oxygen atoms in silica-oxygen tetrahedra and aluminum-oxygen tetrahedra, forming tight ion pairs and occupying the hydroxyl binding sites required for the polycondensation reaction. This inhibits the continuous aggregation of CASH gel and slows down the rate of polymerization. Additionally, Ca2+ attracts oxygen atoms from free water molecules and free OH-, forming Ca(OH)2 dispersed in the spatial structure, which hinders the formation of larger clusters. As a result, the higher the Ca ion content in the system, the lower the overall polymerization degree of the CASH gel, resulting in a decrease in the conversion of the Q1 dimer to Q2 and Q3 chain structures, a shorter average chain length, poorer overall connectivity, and a transition from large clusters in a better-aggregated state to dispersed small clusters. This study sheds light on the polymerization reaction mechanism of CASH gels.

15.
Water Res ; 247: 120819, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37931357

RESUMO

To address the imperative need for efficient removal of uranium-containing wastewater and mitigate radioactive contamination risks associated with nuclear energy, the development of materials with high removal efficiency and facile separation is crucial. This study designed and synthesised MnO2@chitosan (CTS) composite aerogel beads by in-situ growing δ-MnO2 on porous CTS aerogel beads. This approach not only mitigates the agglomeration of MnO2 nanospheres but also significantly enhances the porous structure and surface area of MnO2@CTS. These cost-effective and eco-friendly millimeter-scale spherical aerogels exhibited convenient separation properties after adsorption. These characteristics help mitigate the risk of equipment seam blockage and secondary pollution that are often associated with powdered adsorbents. Additionally, MnO2@CTS exhibited remarkable mechanical strength (stress approximately 0.55 MPa at 60 % strain), enabling rapid separation and easy regeneration while maintaining high adsorption performance even after five cycles. Significantly, MnO2@CTS exhibited a maximum adsorption capacity of 410.7 mg/g at pH 6 and 298 K, surpassing reported values for most CTS/MnO2-based adsorbents. The chemisorption process of U(VI) on MnO2@CTS followed the pseudo-second-order kinetic and Dubinin-Radushkevish models. X-ray photoelectron spectroscopy analysis further confirmed the reduction of U(VI) to U(V/IV). These findings highlight the substantial potential of MnO2@CTS aerogel beads for U(VI) removal from aqueous solutions, positioning them as a promising solution for addressing U(VI) contamination in wastewater.


Assuntos
Quitosana , Urânio , Águas Residuárias , Urânio/análise , Quitosana/química , Compostos de Manganês , Óxidos , Adsorção , Cinética , Concentração de Íons de Hidrogênio
16.
Nanotechnology ; 35(3)2023 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-37848017

RESUMO

Cobalt carbides are emerging as promising materials for various magnetic and catalytic applications. However, exploring dedicated cobalt carbides with optimal catalytic properties via adjusting phase compositions remains a significant challenge. Herein, three different cobalt carbides, CoxC (Co2C-Co3C), Co2C-Co, and Co3C, were successfully prepared using a facile one-pot green method. The phase compositions of cobalt carbides could be easily controlled by varying the cobalt-based precursors and carbon sources. More remarkably, three different cobalt carbides could serve as reduction cocatalysts decorated CdS for improved hydrogen production under visible light. Intriguingly, the obtained Co3C/CdS nanocomposite displayed the highest photocatalytic hydrogen evolution activity among the three composites and superior photocatalytic stability. This work provides a fundamental approach to tuning the photocatalytic properties of cobalt carbides for energy conversion fields.

17.
Curr Pharm Des ; 29(32): 2579-2590, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37881071

RESUMO

BACKGROUND: Rosuvastatin contributes to the improvement of vascular complications in diabetes, but the protective mechanisms remain unclear. The aim of the present study was to investigate the effect and mechanism of rosuvastatin on endothelial dysfunction induced by diabetes. METHODS: Calpain-1 knockout (Capn1 EK684-/-) and C57BL/6 mice were intraperitoneally injected with STZ to induce type 1 diabetes. Human umbilical vein endothelial cells (HUVECs) were incubated with high glucose in this study. The function of isolated vascular rings, apoptosis, and endoplasmic reticulum stress (ERS) indicators were measured in this experiment. RESULTS: The results showed that rosuvastatin (5 mg/kg/d) and calpain-1 knockout improved impaired vasodilation in an endothelial-dependent manner, and this effect was abolished by an ERS inducer. Rosuvastatin administration inhibited calpain-1 activation and ERS induced by high glucose, as well as apoptosis and oxidative stress both in vivo and in vitro. In addition, an ERS inducer (tunicamycin) offset the beneficial effect of rosuvastatin on endothelial dysfunction and ERS, which was accompanied by increased calpain-1 expression. The ERS inhibitor showed a similar improvement in endothelial dysfunction with rosuvastatin but could not increase the improvement in endothelial function of rosuvastatin. CONCLUSION: These results suggested that rosuvastatin improves endothelial dysfunction by suppressing calpain- 1 and normalizing ERS, subsequently decreasing apoptosis and oxidative stress.


Assuntos
Diabetes Mellitus , Doenças Vasculares , Camundongos , Animais , Humanos , Rosuvastatina Cálcica/farmacologia , Rosuvastatina Cálcica/uso terapêutico , Rosuvastatina Cálcica/metabolismo , Calpaína/metabolismo , Camundongos Endogâmicos C57BL , Células Endoteliais da Veia Umbilical Humana/metabolismo , Estresse Oxidativo , Apoptose , Glucose/metabolismo , Estresse do Retículo Endoplasmático , Diabetes Mellitus/metabolismo
18.
Int J Biol Macromol ; 251: 126206, 2023 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-37562482

RESUMO

Incorporating bio-based flame retardants into polylactic acid (PLLA) to improve flame retardancy has always been the focus of research, but the improvement of flame retardancy is usually at the expense of mechanical properties. How to successfully balanced the material's mechanical and combustion properties has puzzled many scholars. Herein, ammonium polyphosphate (APP) and chitosan (CS) were used as acid source and carbon source respectively. Biological flame retardant APP@CS was designed and synthesized by electrostatic self-assembly method. In addition, toughened PLLA composites were prepared by reactive blending with the in-situ formed polyurethane (PU) as toughening phase. The results show that the CS shell not only reduces the hydrophilicity of the flame retardant, but also has good flame retardant property because of its excellent char forming property. The addition of 10 phr APP@CS can endow PLLA/crosslinked PU (CPU) with UL-94 V-2 rating and a LOI value of 24.9 %. Interestingly, CS shell participates in the in-situ reaction, which improves the mechanical properties of the composite with elongation at break of 74 %, which is higher than that of sample doped with the same amount of APP. This work provides guidance for the high performance modification of PLLA and is expected to expand the practical application range.

19.
Chemistry ; 29(54): e202301929, 2023 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-37429820

RESUMO

Moisture harvesters with favourable attributes such as easy synthetic availability and good processability as alternatives for atmospheric moisture harvesting (AWH) are desirable. This study reports a novel nonporous anionic coordination polymer (CP) of uranyl squarate with methyl viologen (MV2+ ) as charge balancing ions (named U-Squ-CP) which displays intriguing sequential water sorption/desorption behavior as the relative humidity (RH) changes gradually. The evaluation of AWH performance of U-Squ-CP shows that it can absorb water vapor under air atmosphere at a low RH of 20 % typical of the levels found in most dry regions of the world, and have good cycling durability, thus demonstrating the capability as a potential moisture harvester for AWH. To the authors' knowledge, this is the first report on non-porous organic ligand bridged CP materials for AWH. Moreover, a stepwise water-filling mechanism for the water sorption/desorption process is deciphered by comprehensive characterizations combining single-crystal diffraction, which provides a reasonable explanation for the special moisture harvesting behaviour of this non-porous crystalline material.

20.
Materials (Basel) ; 16(11)2023 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-37297324

RESUMO

Lithium recovery is imperative to accommodate the increase in lithium demand. Salt lake brine contains a large amount of lithium and is one of the most important sources of lithium metal. In this study, Li2CO3, MnO2, and TiO2 particles were mixed, and the precursor of a manganese-titanium mixed ion sieve (M-T-LIS) was prepared by a high-temperature solid-phase method. M-T-LISs were obtained by DL-malic acid pickling. The adsorption experiment results noted single-layer chemical adsorption and maximum lithium adsorption of 32.32 mg/g. From the Brunauer-Emmett-Teller and scanning electron microscopy results, the M-T-LIS provided adsorption sites after DL-malic acid pickling. In addition, X-ray photoelectron spectroscopy and Fourier transform infrared results showed the ion exchange mechanism of the M-T-LIS adsorption. From the results of the Li+ desorption experiment and recoverability experiment, DL-malic acid was used to desorb Li+ from the M-T-LIS with a desorption rate of more than 90%. During the fifth cycle, the Li+ adsorption capacity of the M-T-LIS was more than 20 mg/g (25.90 mg/g), and the recovery efficiency was higher than 80% (81.42%). According to the selectivity experiment, the M-T-LIS had good selectivity for Li+ (adsorption capacity of 25.85 mg/g in the artificial salt lake brine), which indicates its good application potential.

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