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1.
Pak J Pharm Sci ; 37(1(Special)): 235-243, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38747275

RESUMEN

Stimulus-responsive mesoporous silica nanoparticles (MSNs) have displayed great potentiality for controlled-release and targeted drug delivery. In the current work, a supercritical fluid method was utilized to successfully prepare cinnamon oil loaded into chitosan grafted MSNs (CO@CS-MSNs). The influencing factors of drug loads, such as pressure, temperature, impregnation time and depressure time, were investigated. The structure of CO@CS-MSNs was demonstrated with Fourier-transform infrared (FT-IR) spectroscopy, transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetry (TG) as well as X-ray diffraction (XRD). The drug release assays in vitro at various pH conditions displayed that CO@CS-MSNs had an excellent pH-responsive release behavior, which confirmed that CO was loaded successfully into the CO@CS-MSNs. The findings indicated that the supercritical fluid approach is a non-destructive and efficient approach for stimulus-responsive MSNs, which is expected to further expand its application range.


Asunto(s)
Dióxido de Carbono , Quitosano , Cinnamomum zeylanicum , Liberación de Fármacos , Nanopartículas , Dióxido de Silicio , Quitosano/química , Dióxido de Silicio/química , Nanopartículas/química , Concentración de Iones de Hidrógeno , Dióxido de Carbono/química , Porosidad , Cinnamomum zeylanicum/química , Portadores de Fármacos/química , Aceites Volátiles/química , Aceites Volátiles/administración & dosificación , Difracción de Rayos X , Espectroscopía Infrarroja por Transformada de Fourier , Microscopía Electrónica de Rastreo , Preparaciones de Acción Retardada
2.
Anal Chim Acta ; 1307: 342620, 2024 Jun 08.
Artículo en Inglés | MEDLINE | ID: mdl-38719413

RESUMEN

BACKGROUND: Pharmacokinetic studies are pivotal in drug development, focusing on absorption, distribution, and excretion of active compounds. Effective sample preparation methods play a crucial role in these studies. Traditional techniques like protein precipitation and liquid-liquid extraction often involve toxic solvents and are time-consuming. Recently, deep eutectic solvent (DES) has emerged as an eco-friendly alternative due to its high efficiency, low cost, and low toxicity. This study introduces a novel sample pretreatment method using CO2-switchable DES in liquid-liquid microextraction (LLME) to enhance speed, accuracy, and sensitivity in complex biological samples analysis. RESULTS: A liquid-liquid microextraction sample pretreatment method based on switchable DES combined with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) was established for the analysis of urine and tissue samples. The method was optimized through systematic investigation of key parameters, including DES type, volume, molar ratio, pH, vortex time, gas purge time, and salt addition. The resulting procedure exhibited satisfying linearity (r2 ≥ 0.9958), good precision (RSD ≤6.01 %), desirable recovery (52.44%-98.12 %) and matrix effect (86.22%-119.30 %), and the accuracy and precision of stability were within the ±15 % limit. The proven methods were further applied to urinary excretion study and tissue distribution study of Nelumbinis plumula (NP) extract. The results indicated that the total cumulative excretion of liensinine, isoliensinine and neferine in urine within 240 h was 4.96 %, 0.66 % and 0.44 %, respectively. The tissue distribution study showed that alkaloids mainly distribute in liver, kidney, and spleen. SIGNIFICANCE: This research introduces a groundbreaking technique distinguished by its simplicity, speed, cost-effectiveness, and environmental friendliness. This approach, utilizing CO2-switchable DES as an extraction solvent for LLME, integrates deproteinization and removal of interfering molecules into a single step. This integration showcases its efficiency and convenience, demonstrating significant promise for various applications in the analysis of biological samples. Additionally, this study provides the first report on urinary excretion and tissue distribution of alkaloids from NP using a DES-LLME method. These findings offer valuable insights into the in vivo behavior of herbal medicine, enhancing understanding of pharmacological actions and facilitating clinical rational administration.


Asunto(s)
Dióxido de Carbono , Disolventes Eutécticos Profundos , Microextracción en Fase Líquida , Espectrometría de Masas en Tándem , Microextracción en Fase Líquida/métodos , Dióxido de Carbono/química , Disolventes Eutécticos Profundos/química , Animales , Distribución Tisular , Espectrometría de Masas en Tándem/métodos , Cromatografía Líquida de Alta Presión , Masculino , Ratas , Ratas Sprague-Dawley
3.
Biomacromolecules ; 25(5): 2925-2933, 2024 May 13.
Artículo en Inglés | MEDLINE | ID: mdl-38691827

RESUMEN

A "one-step" strategy has been demonstrated for the tunable synthesis of multifunctional aliphatic polycarbonates (APCs) with ethylene oxide (EO), ethylene carbonate (EC), and cyclohexene oxide (CHO) side groups by the copolymerization of 4-vinyl-1-cyclohexene diepoxide with carbon dioxide under an aminotriphenolate iron/PPNBz (PPN = bis(triphenylphosphine)-iminium, Bz = benzoate) binary catalyst. By adjusting the PPNBz-to-iron complex ratio and incorporating auxiliary solvents, the content of functional side groups can be tuned within the ranges of 53-75% for EO, 18-47% for EC, and <1-7% for CHO. The yield and molecular weight distribution of the resulting multifunctional APCs are affected by the viscosity of the polymerization system. The use of tetrahydrofuran as an auxiliary solvent enables the preparation of narrow-distribution polycarbonates at high conversion. This work presents a novel perspective for the preparation of tailorable multifunctional APCs.


Asunto(s)
Dióxido de Carbono , Cemento de Policarboxilato , Polimerizacion , Dióxido de Carbono/química , Cemento de Policarboxilato/química , Compuestos Epoxi/química , Óxido de Etileno/química , Ciclohexenos/química , Catálisis , Viscosidad , Dioxolanos
4.
J Photochem Photobiol B ; 255: 112924, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38688041

RESUMEN

Whether rapid oxygen isotopic exchange between bicarbonate and water occurs in photosynthesis is the key to determine the source of oxygen by classic 18O-labeled photosynthetic oxygen evolution experiments. Here we show that both Microcystis aeruginosa and Chlamydomonas reinhardtii utilize a significant proportion (>16%) of added bicarbonate as a carbon source for photosynthesis. However, oxygen isotopic signal in added bicarbonate cannot be traced in the oxygen in organic matter synthesized by these photosynthetic organisms. This contradicts the current photosynthesis theory, which states that photosynthetic oxygen evolution comes only from water, and oxygen in photosynthetic organic matter comes only from carbon dioxide. We conclude that the photosynthetic organisms undergo rapid exchange of oxygen isotope between bicarbonate and water during photosynthesis. At the same time, this study also provides isotopic evidence for a new mechanism that half of the oxygen in photosynthetic oxygen evolution comes from bicarbonate photolysis and half comes from water photolysis, which provides a new explanation for the bicarbonate effect, and suggests that the Kok-Joliot cycle of photosynthetic oxygen evolution, must be modified to include a molecule of bicarbonate in addition to one molecule of water which in turn must be incorporated into the cycle instead of two water molecules. Furthermore, this study provides a theoretical basis for constructing a newer artificial photosynthetic reactor coupling light reactions with the dark reactions.


Asunto(s)
Bicarbonatos , Chlamydomonas reinhardtii , Isótopos de Oxígeno , Fotosíntesis , Agua , Bicarbonatos/química , Bicarbonatos/metabolismo , Agua/química , Agua/metabolismo , Isótopos de Oxígeno/química , Chlamydomonas reinhardtii/metabolismo , Microcystis/metabolismo , Oxígeno/metabolismo , Oxígeno/química , Dióxido de Carbono/metabolismo , Dióxido de Carbono/química
5.
Methods Mol Biol ; 2790: 63-76, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38649566

RESUMEN

Stomata can be distributed exclusively on the abaxial or adaxial leaf surface, but they are most commonly found on both leaf surfaces. Variations in stomatal arrangement, patterning, and the impact on photosynthesis can be measured using an infrared gas exchange system. However, when using standard gas exchange techniques, both surfaces are measured together and averaged to provide leaf-level values. Employing an innovative gas exchange apparatus with two infrared gas analyzers, separate gaseous flux from both leaf surfaces can be quantified simultaneously and independently. Here, we provide examples of typical measurements that can be performed using a "split chamber" gas exchange system.


Asunto(s)
Fotosíntesis , Estomas de Plantas , Estomas de Plantas/metabolismo , Estomas de Plantas/fisiología , Gases/química , Hojas de la Planta/metabolismo , Dióxido de Carbono/metabolismo , Dióxido de Carbono/análisis , Dióxido de Carbono/química
6.
J Chromatogr A ; 1722: 464869, 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38604057

RESUMEN

Hydrodynamics, efficiency, and loading capacity of two semi-packed columns with different cross sections (NANO 315 µm x 18 µm; CAP 1000 µm x 28 µm) and similar pillar diameter and pillar-pillar distance (respectively 5 µm and 2.5 µm) have been compared in high-pressure gas chromatography. A flow prediction tool has been first designed to determine pressure variations and hold-up time across the chromatographic system taking into account the rectangular geometry of the ducts into the semi-packed columns. Intrinsic values of Height Equivalent to Theoretical Plate were determined for NANO and CAP columns using helium as carrier gas and similar values have been obtained (30 µm) for the two columns. Loading capacity of semi-packed columns were determined for decane at 70 °C using helium, and the highest value was obtained from CAP column (larger cross section and stationary phase content). Finally, significant HETP improvement (down to 15 µm) and peak shape were observed when carbon dioxide was used as carrier gas, suggesting mobile phase adsorption on stationary phase in high pressure conditions.


Asunto(s)
Helio , Presión , Cromatografía de Gases/métodos , Cromatografía de Gases/instrumentación , Helio/química , Hidrodinámica , Dióxido de Carbono/química , Adsorción
7.
Carbohydr Polym ; 336: 122120, 2024 Jul 15.
Artículo en Inglés | MEDLINE | ID: mdl-38670752

RESUMEN

This study introduces a method for producing printable, thermosensitive bioink formulated from agarose (AG) and carbon dioxide-saturated chitosan (CS) hydrogels. The research identified medium molecular weight chitosan as optimal for bioink production, with a preferred chitosan hydrogel content of 40-60 %. Rheological analysis reveals the bioink's pseudoplastic behavior and a sol-gel phase transition between 27.0 and 31.5 °C. The MMW chitosan-based bioink showed also the most stable extrusion characteristic. The choice of chitosan for the production of bioink was also based on the assessment of the antimicrobial activity of the polymer as a function of its molecular weight and the degree of deacetylation, noting significant cell reduction rates for E. coli and S. aureus of 1.72 and 0.54 for optimal bioink composition, respectively. Cytotoxicity assessments via MTT and LDH tests confirm the bioink's safety for L929, HaCaT, and 46BR.1 N cell lines. Additionally, XTT proliferation assay proved the stimulating effect of the bioink on the proliferation of 46BR.1 N fibroblasts, comparable to that observed with Fetal Bovine Serum (FBS). FTIR spectroscopy confirms the bioink as a physical polymer blend. In conclusion, the CS/AG bioink demonstrates the promising potential for advanced spatial cell cultures in tissue engineering applications including skin regeneration.


Asunto(s)
Dióxido de Carbono , Quitosano , Escherichia coli , Hidrogeles , Tinta , Sefarosa , Quitosano/química , Quitosano/farmacología , Dióxido de Carbono/química , Sefarosa/química , Humanos , Hidrogeles/química , Hidrogeles/farmacología , Animales , Escherichia coli/efectos de los fármacos , Temperatura , Staphylococcus aureus/efectos de los fármacos , Ratones , Reología , Línea Celular , Proliferación Celular/efectos de los fármacos , Ingeniería de Tejidos/métodos , Antibacterianos/farmacología , Antibacterianos/química , Fibroblastos/efectos de los fármacos
8.
Waste Manag ; 181: 11-19, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38574688

RESUMEN

Mattresses are a difficult waste to manage in landfills due to their large volume and low density. Pyrolysis treatment could reduce its volume while producing fuel or products valuable for the chemical industry. Pressurized pyrolysis at 400, 450, and 500 °C is carried out in a lab-scale autoclave at initial pressures 4.2, 8.4, and 16.8 bar. Product gas yield increases slightly along with elevated pressure as well as temperature. However, beyond 8.4 bar the initial pressure makes no discernible differences. CO and CO2 are the major gas species followed by CH4. CO contributes the most to the product gas energy content followed by C3 species, C2H6, and H2. Calculated energy content (heating value) is between 2 and 15 MJ·Nm-3. In terms of product gas energy content, low pressure pyrolysis is favorable over high pressure pyrolysis. According to integration areas of chromatographic measurements the liquid phase contains up to 25 % of N-compounds, with benzonitrile being the most abundant, followed by toluene, o-xylene, and ethylbenzene. The solid char maintains constant properties across operating conditions, with carbon and energy contents of approximately 75 wt% and 30 MJ·kg-1, respectively.


Asunto(s)
Pirólisis , Instalaciones de Eliminación de Residuos , Eliminación de Residuos/métodos , Presión , Administración de Residuos/métodos , Metano/análisis , Metano/química , Dióxido de Carbono/análisis , Dióxido de Carbono/química
9.
Waste Manag ; 181: 199-210, 2024 May 30.
Artículo en Inglés | MEDLINE | ID: mdl-38643515

RESUMEN

Supercritical CO2 (scCO2) extraction assisted by complexing copolymers is a promising process to recover valuable metals from lithium-ion batteries (LIBs). CO2, in addition to being non-toxic, abundant and non-flammable, allows an easy separation of metal-complexes from the extraction medium by depressurization, limiting the wastewater production. In this study, CO2-philic gradient copolymers bearing phosphonic diacid complexing groups (poly(vinylbenzylphosphonic diacid-co-1,1,2,2-tetrahydroperfluorodecylacrylate), p(VBPDA-co-FDA)) were synthesized for the extraction of lithium and cobalt from LiCoO2 cathode material. Notably, the copolymer was able to play the triple role of leaching agent, complexing agent and surfactant. The proof of concept for leaching, complexation and extraction was achieved, using two different extraction systems. A first extraction system used aqueous hydrogen peroxide as reducing agent while it was replaced by ethanol in the second extraction system. The scCO2 extraction conditions such as extraction time, temperature, functional copolymer concentration, and the presence of additives were optimized to improve the metals extraction from LiCoO2 cathode material, leading to an extraction efficiency of Li and Co up to ca. 75 % at 60 °C and 250 bar.


Asunto(s)
Dióxido de Carbono , Cobalto , Litio , Polímeros , Cobalto/química , Cobalto/aislamiento & purificación , Litio/química , Dióxido de Carbono/química , Polímeros/química , Óxidos/química , Reciclaje/métodos , Electrodos , Suministros de Energía Eléctrica
10.
Environ Sci Technol ; 58(16): 7196-7207, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38597822

RESUMEN

Aerosols produced in the amine carbon capture process can lead to secondary environmental pollution. This study employs molecular dynamics (MD) simulations to investigate cluster formation, amine behavior, and aerosol growth of amines, essential for reducing amine aerosol emissions. Results showed that the cluster evolution process can be divided into cluster formation and growth in terms of molecular content, and the nucleation rate for the present systems was estimated in the order of 1028 cm-3 s-1. CO2 absorption was observed alongside successful nucleation, with CO2 predominantly localizing in the cluster's outer layer postabsorption. Monoethanolamine (MEA) exhibited robust electrostatic interactions with other components via hydrogen bonding, leading to its migration toward regions where CO2 and H2O coexisted within the cluster. While MEA presence markedly spurred cluster formation, its concentration had a marginal effect on the final cluster size. Elevating water content can augment the aerosol growth rate. However, altering the gas saturation is possible only within narrow confines by introducing vapor. Contrarily, gas cooling introduced dual, opposing effects on aerosol growth. These findings, including diffusion coefficients and growth rates, enhance theoretical frameworks for predicting aerosol formation in absorbers, aiding in mitigating environmental impacts of amine-based carbon capture.


Asunto(s)
Aerosoles , Dióxido de Carbono , Dióxido de Carbono/química , Simulación de Dinámica Molecular , Aminas/química
11.
Environ Sci Technol ; 58(16): 6978-6987, 2024 Apr 23.
Artículo en Inglés | MEDLINE | ID: mdl-38598712

RESUMEN

Decarbonization of the cement sector is essentially required to achieve carbon neutrality to combat climate change. Amine-based CO2 capture is a leading and practical technology to deeply remove CO2 from the cement industry, owing to its high retrofittability to existing cement plants and extensive engineering experience in industrial flue gas decarbonization. While research efforts have been made to achieve low-carbon cement with 90% CO2 removal, a net-zero-emission cement plant that will be required for a carbon neutrality society has not yet been investigated. The present study proposed an advanced amine-based CO2 capture system integrated with a cement plant to achieve net-zero CO2 emission by pushing the CO2 capture efficiency to 99.7%. Monoethanomaine (MEA) and piperazine/2-amino-2-methyl-1-propanol (PZ-AMP) amine systems, which are considered to be the first- and second-generation capture agents, respectively, were detailed investigated to deeply decarbonize the cement plant. Compared to MEA, the advanced PZ-AMP system exhibited excellent energy performance with a regeneration duty of ∼2.6 GJ/tonne CO2 at 99.7% capture, 39% lower than the MEA process. This enabled a low CO2 avoided cost of $72.0/tonne CO2, which was 18% lower than that of the MEA-based zero-emission process and even 16.2% lower than the standard 90% MEA process. Sensitivity analysis revealed that the zero-emission capture cost of the PZ-AMP system would be further reduced to below $56/tonne CO2 at a $4/GJ steam production cost, indicating its economic competitiveness among various CO2 capture technologies to achieve a zero-emission cement plant.


Asunto(s)
Aminas , Dióxido de Carbono , Dióxido de Carbono/química , Aminas/química , Materiales de Construcción
12.
PLoS One ; 19(4): e0299831, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38635503

RESUMEN

This article examines the role of legal structure in explaining financial development in twenty-three emerging markets, which has not been explored in institutional economics literature before. This study relied on Pedroni, and Kao cointegration tests, which is followed by the renowned panel cointegration technique. The results of the Pedroni and Kao cointegration tests show that the variables understudy is cointegrated in the long-run. These findings are confirmed by the panel cointegration showing that legal structure (LS) has positive impact on financial development (FIND) in long-run that support Law and Finance, and New Institutional Economics theories in emerging markets. This study is the first to directly examine the long-run impact of LS on FIND in emerging markets, and the result remains consistent across alternative measure of FIND. The findings of this study have important policy implications for emerging markets. Policymakers should focus on creating a legal environment that is conducive to financial development. This includes strengthening the legal framework, improving regulatory regimes, and promoting market autonomy. Additionally, policymakers should work to attract foreign investment, which can help spur economic growth and development in emerging markets. The findings of the study are consistent across battery of robustness testing.


Asunto(s)
Dióxido de Carbono , Desarrollo Económico , Dióxido de Carbono/química , Inversiones en Salud , Internacionalidad , Políticas
13.
Compr Rev Food Sci Food Saf ; 23(3): e13345, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38638070

RESUMEN

Supercritical carbon dioxide (SC-CO2) has emerged as a nonthermal technology to guarantee food safety. This review addresses the potential of SC-CO2 technology in food preservation, discussing the microbial inactivation mechanisms and the impact on food products' quality parameters and bioactive compounds. Furthermore, the main advantages and gaps are denoted. SC-CO2 technology application causes adequate microbial reductions (>5 log cfu/mL) of spoilage and pathogenic microorganisms, enzyme inactivation, and improvements in the storage stability in fruit and vegetable products (mainly fruit juices), meat products, and dairy derivatives. SC-CO2-treated products maintain the physicochemical, technological, and sensory properties, bioactive compound concentrations, and biological activity (antioxidant and angiotensin-converting enzyme-inhibitory activities) similar to the untreated products. The optimization of processing parameters (temperature, pressure, CO2 volume, and processing times) is mandatory for achieving the desired results. Further studies should consider the expansion to different food matrices, shelf-life evaluation, bioaccessibility of bioactive compounds, and in vitro and in vivo studies to prove the benefits of using SC-CO2 technology. Moreover, the impact on sensory characteristics and, mainly, the consumer perception of SC-CO2-treated foods need to be elucidated. We highlight the opportunity for studies in postbiotic production. In conclusion, SC-CO2 technology may be used for microbial inactivation to ensure food safety without losing the quality parameters.


Asunto(s)
Dióxido de Carbono , Comprensión , Viabilidad Microbiana , Dióxido de Carbono/química , Dióxido de Carbono/farmacología , Recuento de Colonia Microbiana , Manipulación de Alimentos/métodos
14.
Molecules ; 29(8)2024 Apr 12.
Artículo en Inglés | MEDLINE | ID: mdl-38675575

RESUMEN

BACKGROUND: Myrtle (Myrtus communis L.) is a coastal Mediterranean aromatic medicinal plant rich in essential oil components, flavonoids, and phenolic acids. Studies highlight the potential health benefits of myrtle bioactive compounds with antioxidant and antiproliferative properties. Since limited research exists on myrtle fruit's lipid fraction, the aim of this study was to apply supercritical CO2 extraction to obtain bioactive compounds from myrtle berries focusing on the fatty acids, sterols, and essential oils. METHODS: The optimization of the supercritical CO2 extraction of myrtle fruit using CO2 as solvent was carried out using the response surface methodology with Box-Behnken experimental design. The following conditions were tested: temperature (40, 50, and 60 °C), pressure (200, 300, and 400 bar), and flow rate (20, 30, and 40 g min-1) on the yield of lipid extract as well as on the yield of fatty acids, phytosterols, and volatiles present in the extract and constituting its bioactive potential. RESULTS: In the extracts examined, 36 fatty acids, 7 phytosterols, and 13 volatiles were identified. The average yield of the extract was 5.20%, the most abundant identified fatty acid was essential cis-linolenic acid (76.83%), almost 90% of the total phytosterols were ß-sitosterol (12,465 mg kg-1), while myrtenyl acetate (4297 mg kg-1) was the most represented volatile compound. The optimal process conditions obtained allow the formulation of extracts with specific compositions.


Asunto(s)
Dióxido de Carbono , Ácidos Grasos , Frutas , Myrtus , Fitosteroles , Fitosteroles/aislamiento & purificación , Fitosteroles/química , Fitosteroles/análisis , Myrtus/química , Dióxido de Carbono/química , Ácidos Grasos/química , Ácidos Grasos/análisis , Ácidos Grasos/aislamiento & purificación , Frutas/química , Extractos Vegetales/química , Aceites Volátiles/química , Aceites Volátiles/aislamiento & purificación , Cromatografía con Fluido Supercrítico/métodos , Compuestos Orgánicos Volátiles/aislamiento & purificación , Compuestos Orgánicos Volátiles/química , Compuestos Orgánicos Volátiles/análisis
15.
Environ Sci Technol ; 58(17): 7445-7456, 2024 Apr 30.
Artículo en Inglés | MEDLINE | ID: mdl-38622030

RESUMEN

The tandem application of CO2 electrolysis with syngas fermentation holds promise for achieving heightened production rates and improved product quality. However, the significant impact of syngas composition on mixed culture-based microbial chain elongation remains unclear. Additionally, effective methods for generating syngas with an adjustable composition from acidic CO2 electrolysis are currently lacking. This study successfully demonstrated the production of medium-chain fatty acids from CO2 through tandem acidic electrolysis with syngas fermentation. CO could serve as the sole energy source or as the electron donor (when cofed with acetate) for caproate generation. Furthermore, the results of gas diffusion electrode structure engineering highlighted that the use of carbon black, either alone or in combination with graphite, enabled consistent syngas generation with an adjustable composition from acidic CO2 electrolysis (pH 1). The carbon black layer significantly improved the CO selectivity, increasing from 0% to 43.5% (0.05 M K+) and further to 92.4% (0.5 M K+). This enhancement in performance was attributed to the promotion of K+ accumulation, stabilizing catalytically active sites, rather than creating a localized alkaline environment for CO2-to-CO conversion. This research contributes to the advancement of hybrid technology for sustainable CO2 reduction and chemical production.


Asunto(s)
Dióxido de Carbono , Electrólisis , Ácidos Grasos , Fermentación , Dióxido de Carbono/química , Ácidos Grasos/metabolismo
16.
J Agric Food Chem ; 72(17): 9967-9973, 2024 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-38639643

RESUMEN

The use of convertible immobilized enzyme carriers is crucial for biphasic catalytic reactions conducted in Pickering emulsions. However, the intense mechanical forces during the conversion process lead to enzyme leakage, affecting the stability of the immobilized enzymes. In this study, a CO2-responsive switchable Janus (CrSJ) nanoparticle (NP) was developed using silica NP, with one side featuring aldehyde groups and the other side adsorbing N,N-dimethyldodecylamine. A switchable Pickering emulsion catalytic system for biphasic interface reactions was prepared by covalently immobilizing lipase onto the CrSJ NPs. The CO2-responsive nature of the CrSJ NPs allowed for rapid conversion of the Pickering emulsion, and covalent immobilization substantially reduced lipase leakage while enhancing the stability of the immobilization during the conversion process. Impressively, after repeated transformations, the Pickering emulsion still maintains its original structure. Following 10 consecutive cycles of esterification and hydrolysis reactions, the immobilized enzyme's activity remains at 77.7 and 79.5% of its initial activity, respectively. The Km of the CrSJ catalytic system showed no significant change compared to the free enzyme, while its Vmax values were 1.2 and 1.6 times that of the free enzyme in esterification and hydrolysis reactions, respectively.


Asunto(s)
Biocatálisis , Dióxido de Carbono , Emulsiones , Enzimas Inmovilizadas , Lipasa , Nanopartículas , Lipasa/química , Lipasa/metabolismo , Enzimas Inmovilizadas/química , Enzimas Inmovilizadas/metabolismo , Emulsiones/química , Nanopartículas/química , Dióxido de Carbono/química , Dióxido de Carbono/metabolismo , Esterificación , Estabilidad de Enzimas , Cinética , Dióxido de Silicio/química , Catálisis , Hidrólisis
17.
J Transl Med ; 22(1): 339, 2024 Apr 09.
Artículo en Inglés | MEDLINE | ID: mdl-38594760

RESUMEN

One of the most effective strategies to fight viruses and handle health diseases is vaccination. Recent studies and current applications are moving on antigen, DNA and RNA-based vaccines to overcome the limitations related to the conventional vaccination strategies, such as low safety, necessity of multiple injection, and side effects. However, due to the instability of pristine antigen, RNA and DNA molecules, the use of nanocarriers is required. Among the different nanocarriers proposed for vaccinal applications, three types of nanovesicles were selected and analysed in this review: liposomes, transfersomes and niosomes. PubMed, Scopus and Google Scholar databases were used for searching recent papers on the most frequently used conventional and innovative methods of production of these nanovesicles. Weaknesses and limitations of conventional methods (i.e., multiple post-processing, solvent residue, batch-mode processes) can be overcome using innovative methods, in particular, the ones assisted by supercritical carbon dioxide. SuperSomes process emerged as a promising production technique of solvent-free nanovesicles, since it can be easily scaled-up, works in continuous-mode, and does not require further post-processing steps to obtain the desired products. As a result of the literature analysis, supercritical carbon dioxide assisted methods attracted a lot of interest for nanovesicles production in the vaccinal field. However, despite their numerous advantages, supercritical processes require further studies for the production of liposomes, transfersomes and niosomes with the aim of reaching well-defined technologies suitable for industrial applications and mass production of vaccines.


Asunto(s)
Liposomas , Vacunas , Liposomas/química , Dióxido de Carbono/química , Solventes , ADN , ARN
18.
Waste Manag ; 182: 21-31, 2024 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-38631177

RESUMEN

This research investigates the formation mechanism of soot and particulate matter during the pyrolysis and gasification of waste derived from Municipal Solid Waste (MSW) in a laboratory scale drop tube furnace. Compared with CO2 gasification atmosphere, more ultrafine particles (PM0.2, aerodynamic diameter less than 0.2 µm) were generated in N2 atmosphere at 1200℃, which were mainly composed of polycyclic aromatic hydrocarbons (PAHs), graphitic carbonaceous soot and volatile alkali salts. High reaction temperatures promote the formation of hydrocarbon gaseous products and their conversion to PAHs, which ultimately leads to the formation of soot particles. The soot particles generated by waste derived from MSW pyrolysis and gasification both have high specific surface area and well-developed pore structure. Compared with pyrolysis, the soot generated by gasification of waste derived from MSW had smaller size and higher proportion of inorganic components. The higher pyrolysis temperature led to the collapse of the mesoporous structure of submicron particles, resulting in a decrease in total pore volume and an increase in specific surface area. Innovatively, this research provides an explanation for the effect of reaction temperature/ CO2 on the formation pathways and physicochemical properties of soot and fine particulate matter.


Asunto(s)
Calor , Material Particulado , Pirólisis , Residuos Sólidos , Hollín , Material Particulado/análisis , Material Particulado/química , Residuos Sólidos/análisis , Hollín/análisis , Hollín/química , Eliminación de Residuos/métodos , Incineración/métodos , Dióxido de Carbono/análisis , Dióxido de Carbono/química , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/química , Tamaño de la Partícula
19.
Food Chem ; 449: 139218, 2024 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-38579656

RESUMEN

High costs and low performance have constrained the application of bio-based materials in food packaging. Herein, a series of ultra-thin poly(L-lactic acid-iconic acid N-diol) (P(LA-NI)) copolymer films were developed using a "one-step" polycondensation process with integrated toughness, barrier properties, gas selectivity, and quality control features. The massive branched structure and gg conformers in P(LA-NI) act as "internal chain expansion" and "internal plasticization". Meanwhile, P(LA-NI) contains numerous polar groups and unique nanoscale microphase structures to realize excellent CO2, O2 barrier, CO2/O2 selectivity, anti-fogging, and UV shielding functions. The atmosphere within the package spontaneously achieves the desirable low O2 and high CO2 levels when packaging button mushrooms with high respiratory metabolism. Eventually, the shelf life of button mushrooms reached 24 days, >3-fold extended. This PLLA-based film meets "dual carbon" and "food safety" goals and has vast potential for fresh food preservation.


Asunto(s)
Dióxido de Carbono , Embalaje de Alimentos , Oxígeno , Poliésteres , Embalaje de Alimentos/instrumentación , Poliésteres/química , Dióxido de Carbono/química , Oxígeno/química , Conservación de Alimentos/métodos , Conservación de Alimentos/instrumentación , Permeabilidad
20.
Environ Sci Technol ; 58(19): 8313-8325, 2024 May 14.
Artículo en Inglés | MEDLINE | ID: mdl-38689207

RESUMEN

CO2 is 45 to 50 times more concentrated in soil than in air, resulting in global diffusive fluxes that outpace fossil fuel combustion by an order of magnitude. Despite the scale of soil CO2 emissions, soil-based climate change mitigation strategies are underdeveloped. Existing approaches, such as enhanced weathering and sustainable land management, show promise but continue to face deployment barriers. We introduce an alternative approach: the use of solid adsorbents to directly capture CO2 in soils. Biomass-derived adsorbents could exploit favorable soil CO2 adsorption thermodynamics while also sequestering solid carbon. Despite this potential, previous study of porous carbon CO2 adsorption is mostly limited to single-component measurements and conditions irrelevant to soil. Here, we probe sorption under simplified soil conditions (0.2 to 3% CO2 in balance air at ambient temperature and pressure) and provide physical and chemical characterization data to correlate material properties to sorption performance. We show that minimally engineered pyrogenic carbons exhibit CO2 sorption capacities comparable to or greater than those of advanced sorbent materials. Compared to textural features, sorbent carbon bond morphology substantially influences low-pressure CO2 adsorption. Our findings enhance understanding of gas adsorption on porous carbons and inform the development of effective soil-based climate change mitigation approaches.


Asunto(s)
Dióxido de Carbono , Carbono , Suelo , Dióxido de Carbono/química , Suelo/química , Porosidad , Adsorción , Carbono/química , Carbón Orgánico/química , Cambio Climático
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