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1.
J Am Chem Soc ; 146(4): 2465-2473, 2024 Jan 31.
Artículo en Inglés | MEDLINE | ID: mdl-38232304

RESUMEN

Photocatalytic oxidative coupling of methane (OCM) into value-added industrial chemicals offers an appealing green technique for achieving sustainable development, whereas it encounters double bottlenecks in relatively low methane conversion rate and severe overoxidation. Herein, we engineer a continuous gas flow system to achieve efficient photocatalytic OCM while suppressing overoxidation by synergizing the moderate active oxygen species, surface plasmon-mediated polarization, and multipoint gas intake flow reactor. Particularly, a remarkable CH4 conversion rate of 218.2 µmol h-1 with an excellent selectivity of ∼90% toward C2+ hydrocarbons and a remarkable stability over 240 h is achieved over a designed Au/TiO2 photocatalyst in our continuous gas flow system with a homemade three-dimensional (3D) printed flow reactor. This work provides an informative concept to engineer a high-performance flow system for photocatalytic OCM by synergizing the design of the reactor and photocatalyst to synchronously regulate the mass transfer, activation of reactants, and inhibition of overoxidation.

2.
Acta Biochim Biophys Sin (Shanghai) ; 56(4): 597-606, 2024 04 25.
Artículo en Inglés | MEDLINE | ID: mdl-38404179

RESUMEN

The aryl hydrocarbon receptor (AHR) has been identified as a significant driver of tumorigenesis. However, its clinical significance in acute myeloid leukemia (AML) remains largely unclear. In this study, RNA-Seq data from AML patients (bone marrow samples from 173 newly diagnosed AML patients) obtained from the TCGA database, and normal human RNA-Seq data (bone marrow samples from 70 healthy individuals) obtained from the GTEX database are downloaded for external validation and complementarity. The data analysis reveals that the AHR signaling pathway is activated in AML patients. Furthermore, there is a correlation between the expressions of AHR and mitochondrial oxidative phosphorylation genes. In vitro experiments show that enhancing AHR expression in AML cells increases mitochondrial oxidative phosphorylation and induces resistance to cytarabine. Conversely, reducing AHR expression in AML cells decreases cytarabine resistance. These findings deepen our understanding of the AHR signaling pathway's involvement in AML.


Asunto(s)
Citarabina , Leucemia Mieloide Aguda , Humanos , Citarabina/farmacología , Fosforilación Oxidativa , Receptores de Hidrocarburo de Aril/genética , Receptores de Hidrocarburo de Aril/metabolismo , Transducción de Señal , Leucemia Mieloide Aguda/tratamiento farmacológico , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo
3.
Artículo en Inglés | MEDLINE | ID: mdl-38324038

RESUMEN

This study aimed to identify risk and protective factors for suicidal tendencies among college students by exploring current mental health, personal experiences, family environment, and school adaptation. A total of 11,504 freshmen in China were recruited. Suicidal tendencies were assessed using the Adolescents Suicidal Tendencies Scale (ASTS), while explored risk and protective factors included mental health assessed by the Symptom Checklist-90 (SCL-90), campus adaptation using the College Student School Adaptation Scale, and Personal Situation Survey. Single-factor Logistic regression analysis, correlation analysis, and hierarchical regression analysis were used to analyze the risk and protective factors affecting suicidal tendencies. The results showed that in terms of personal experience, self-injury behavior (OR = 3.522, 95% CI [3.256, 3.811]), sexual assault experience (OR = 2.603, 95% CI [2.374, 2.855]) and lack of friendship relationship (OR = 2.249, 95% CI [2.076, 2.436]) were the most significant risk factors. Regarding family environment, parenting style (OR = 2.455, 95% CI [2.272, 2.652]), parent-child relationship (OR = 2.255, 95% CI [2.092, 2.429]) and violent conflict (OR = 2.164, 95% CI [2.015, 2.324]) were the most prominent risk factors. For protective factors, life satisfaction (OR = 0.330, 95% CI [0.304, 0.359]) and rest quality (OR = 0.415, 95% CI [0.386, 0.447]) were the most significant protective factors. In addition, Symptom Checklist-90 was positively correlated with suicidal tendencies (r = 0.541, 95% CI [0.522, 0.560], p < 0.001), while school adaptation was negatively correlated with suicidal tendencies (r = - 0.590, 95% CI [- 0.579, - 0.601], p < 0.001). After considering demographic variables, psychological symptoms, school adaptation and other risk and protective factors, the hierarchical regression model could explain 48.9% of the variance of suicidal tendencies. The study emphasizes a range of multidimensional risk and protective factors for suicidal tendencies. This enhanced understanding is crucial in aiding the design of future intervention studies targeted at improving the mental health of college students.

4.
Nano Lett ; 23(22): 10545-10553, 2023 Nov 22.
Artículo en Inglés | MEDLINE | ID: mdl-37937844

RESUMEN

Misuse of opioids can lead to a potential lethal overdose. Timely administration of naloxone is critical for survival. Here, we designed a polymer-naloxone conjugate that can provide on-demand phototriggered opioid reversal. Naloxone was attached to the polymer poly(lactic-co-glycolic acid) via a photocleavable coumarin linkage and formulated as injectable nanoparticles. In the absence of irradiation, the formulation did not release naloxone. Upon irradiation with blue (400 nm) light, the nanoparticles released free naloxone, reversing the effect of morphine in mice. Such triggered events could be performed days and weeks after the initial administration of the nanoparticles and could be performed repeatedly.


Asunto(s)
Sobredosis de Droga , Naloxona , Ratones , Animales , Naloxona/farmacología , Naloxona/uso terapéutico , Analgésicos Opioides/uso terapéutico , Antagonistas de Narcóticos/uso terapéutico , Polímeros/farmacología , Polímeros/uso terapéutico , Sobredosis de Droga/tratamiento farmacológico
5.
J Am Chem Soc ; 145(49): 26817-26823, 2023 Dec 13.
Artículo en Inglés | MEDLINE | ID: mdl-38019281

RESUMEN

Generative artificial intelligence has depicted a beautiful blueprint for on-demand design in chemical research. However, the few successful chemical generations have only been able to implement a few special property values because most chemical descriptors are mathematically discrete or discontinuously adjustable. Herein, we use spectroscopic descriptors with machine learning to establish a quantitative spectral structure-property relationship for adsorbed molecules on metal monatomic catalysts. Besides catalytic properties such as adsorption energy and charge transfer, the complete spatial relative coordinates of the adsorbed molecule were successfully inverted. The spectroscopic descriptors and prediction models are generalized, allowing them to be transferred to several different systems. Due to the continuous tunability of the spectroscopic descriptors, the design of catalytic structures with continuous adsorption states generated by AI in the catalytic process has been achieved. This work paves the way for using spectroscopy to enable real-time monitoring of the catalytic process and continuous customization of catalytic performance, which will lead to profound changes in catalytic research.

6.
Mol Pharm ; 20(2): 1375-1381, 2023 02 06.
Artículo en Inglés | MEDLINE | ID: mdl-36633440

RESUMEN

Drug delivery directly across the tympanic membrane (TM) could eliminate systemic exposure to antibiotics prescribed for otitis media, the most common reason for pediatricians to prescribe antibiotics. Here, we hypothesized that inducing inflammation of the TM could enhance drug flux across the TM. We demonstrated that the flux of ciprofloxacin across the TM was greatly increased by treatment with the proinflammatory agent histamine. That enhancement was blocked by concurrent treatment with blockers of histamine receptor 1. Treatment of the TM with histamine was able to enhance drug flux sufficiently to eradicate otitis media in vivo in chinchillas, but only if the histamine was applied prior to treatment with antibiotics.


Asunto(s)
Otitis Media , Membrana Timpánica , Humanos , Histamina/uso terapéutico , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Otitis Media/tratamiento farmacológico , Inflamación/tratamiento farmacológico
7.
J Am Chem Soc ; 144(35): 16069-16076, 2022 09 07.
Artículo en Inglés | MEDLINE | ID: mdl-36001497

RESUMEN

Learning microscopic properties of a material from its macroscopic measurables is a grand and challenging goal in physical science. Conventional wisdom is to first identify material structures exploiting characterization tools, such as spectroscopy, and then to infer properties of interest, often with assistance of theory and simulations. This indirect approach has limitations due to the accumulation of errors from retrieving structures from spectral signals and the lack of quantitative structure-property relationship. A new pathway directly from spectral signals to microscopic properties is highly desirable, as it would offer valuable guidance toward materials evaluation and design via spectroscopic measurements. Herein, we exploit machine-learned vibrational spectroscopy to establish quantitative spectrum-property relationships. Key interaction properties of substrate-adsorbate systems, including adsorption energy and charge transfer, are quantitatively determined directly from Infrared and Raman spectroscopic signals of the adsorbates. The machine-learned spectrum-property relationships are presented as mathematical formulas, which are physically interpretable and therefore transferrable to a series of metal/alloy surfaces. The demonstrated ability of quantitative determination of hard-to-measure microscopic properties using machine-learned spectroscopy will significantly broaden the applicability of conventional spectroscopic techniques for materials design and high throughput screening under operando conditions.


Asunto(s)
Espectrometría Raman , Vibración , Adsorción , Aprendizaje Automático , Espectrometría Raman/métodos , Propiedades de Superficie
8.
Neuroepidemiology ; 56(1): 50-58, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-34758470

RESUMEN

BACKGROUND: Parkinson's disease (PD) is a common neurodegenerative disease. With the aging of the Chinese population, it is important to understand the prevalence of PD in the elderly. OBJECTIVE: Little data are available on the current prevalence of PD in China. The aim of this study was to determine the prevalence of PD in Chinese individuals aged 65 years and older and to analyze associated risk factors. METHODS: We performed a population-based cross-sectional survey using a multistage cluster sampling design. Residents aged 65 years and older were drawn from 11 urban districts and 10 rural counties across China. Data were entered into spreadsheets and analyzed using SPSS 24. RESULTS: We identified 151 patients with PD among 8,124 residents aged 65 years and over, including 75 men and 76 women. The overall prevalence of PD in the study population was 1.86%, and the standardized prevalence of PD was 1.60%. The crude prevalence in men (2.12%) was higher than that in women (1.66%) and the standardized prevalence in urban areas (1.98%) was higher than that in rural areas (1.48%). Logistic regression analysis showed that independent risk factors for PD were older age, heavy metal or pesticide exposure, urban residence, rapid eye movement sleep behavior disorder, and heart disease. CONCLUSIONS: The prevalence of PD among individuals aged 65 years and older in China has remained constant. The prevalence of PD is higher in men than in women and higher in urban areas than in rural areas.


Asunto(s)
Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Adulto , Anciano , China/epidemiología , Estudios Transversales , Femenino , Humanos , Masculino , Enfermedad de Parkinson/epidemiología , Prevalencia , Factores de Riesgo , Población Rural , Población Urbana
9.
Adv Funct Mater ; 31(44)2021 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-34795553

RESUMEN

The prevalence of ear disorders has spurred efforts to develop drug delivery systems to treat these conditions. Here, recent advances in drug delivery systems that access the ear through the tympanic membrane (TM) are reviewed. Such methods are either non-invasive (placed on the surface of the TM), or invasive (placed in the middle ear, ideally on the round window [RW]). The major hurdles to otic drug delivery are identified and highlighted the representative examples of drug delivery systems used for drug delivery across the TM to the middle and (crossing the RW also) inner ear.

10.
Theor Appl Genet ; 134(4): 1095-1122, 2021 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-33420806

RESUMEN

Soybean is one main source of dietary protein; therefore, improving protein content is an important objective in breeding programs. There is a significant negative correlation between protein and oil content, which influenced mapping quantitative trait locus (QTL) and quantitative trait nucleotides for these two traits. In this study, a linkage map was created with 2232 single-nucleotide polymorphism markers for the four-way recombinant inbred line (FW-RIL) population derived from the cross (Kenfeng 14 × Kenfeng 15) × (Heinong 48 × Kenfeng 19), and then conditional and unconditional QTL analyses were carried out by inclusive complete interval mapping based on the phenotypic data of protein and oil content collected in 10 different environments. As shown in the results of linkage analysis, a total of 85 QTL have been detected. We have performed association analysis using 109,676 markers after quality filtering for FW-RIL, and the results have shown that a total of 60 QTNs were detected. We have performed association analysis using 63,306 markers after quality filtering for resource population, and the results have shown that a total of 123 QTNs were detected. We have combined linkage and association analysis, and there are six QTNs verified by FW-RIL and resource population. We have performed pathway analysis on the genes in these six QTN attenuation regions, and the result shows that a total of four candidate genes are related to the synthesis or metabolism of soybean protein. These findings will facilitate marker-assisted selection and molecular breeding of soybean.


Asunto(s)
Mapeo Cromosómico/métodos , Cromosomas de las Plantas/genética , Glycine max/metabolismo , Polimorfismo de Nucleótido Simple , Sitios de Carácter Cuantitativo , Proteínas de Soja/metabolismo , Ligamiento Genético , Genoma de Planta , Estudio de Asociación del Genoma Completo , Fenotipo , Fitomejoramiento , Proteínas de Soja/genética , Glycine max/genética , Glycine max/crecimiento & desarrollo
11.
Compr Rev Food Sci Food Saf ; 20(4): 3937-3982, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33938124

RESUMEN

The past two decades have witnessed a global surge in the application of probiotics as functional ingredients in food, animal feed, and pharmaceutical products. Among food industries, the dairy industry is the largest sector where probiotics are employed in a number of dairy products including sour/fermented milk, yogurt, cheese, butter/cream, ice cream, and infant formula. These probiotics are either used as starter culture alone or in combination with traditional starters, or incorporated into dairy products following fermentation, where their presence imparts many functional characteristics to the product (for instance, improved aroma, taste, and textural characteristics), in addition to conferring many health-promoting properties. However, there are still many challenges related to the stability and functionality of probiotics in dairy products. This review highlights the advances, opportunities, and challenges of application of probiotics in dairy industries. Benefits imparted by probiotics to dairy products including their role in physicochemical characteristics and nutritional properties (clinical and functional perspective) are also discussed. We transcend the traditional concept of the application of probiotics in dairy products and discuss paraprobiotics and postbiotics as a newly emerged concept in the field of probiotics in a particular relation to the dairy industry. Some potential applications of paraprobiotics and postbiotics in dairy products as functional ingredients for the development of functional dairy products with health-promoting properties are briefly elucidated.


Asunto(s)
Queso , Probióticos , Animales , Industria Lechera , Humanos , Leche , Yogur
12.
J Phys Chem A ; 124(47): 9692-9697, 2020 Nov 25.
Artículo en Inglés | MEDLINE | ID: mdl-33198457

RESUMEN

Small-molecule anion carriers are potential reagents used in the treatment of diseases caused by dysregulated anion transport. Photoswitchable anion receptors, which can be reversibly switched between isomers by light and thereby cause reversible changes in anion binding affinity, have been receiving enormous interest. Here, based on the well-known photoswitch 1-N-methyl-3-phenylazopyrazole (3pzH), we designed a novel tetramethylamide-3pzH (3pzH_TA) photoswitchable receptor that achieves highly efficient and durable anion transportation. It enables high photoisomerization ratios of E → Z (>98%) and Z → E (97%) with a thermal half-life two times longer than that of 3pzH. We further demonstrated the high sensitivity of 3pzH_TA toward H2PO4- anion and revealed the key role of hydrogen bonds between H2PO4- and Z isomer in the strength of anion binding. Our findings open up a new strategy for the rational design and understanding of new types of photoswitchable anion receptors.


Asunto(s)
Compuestos Azo/química , Luz , Fosfatos/química , Pirazoles/química , Aniones , Teoría Funcional de la Densidad , Transporte Iónico , Isomerismo
13.
Small ; 15(31): e1901617, 2019 08.
Artículo en Inglés | MEDLINE | ID: mdl-31187930

RESUMEN

To solve the clinical challenges presented by the long-term tracking of implanted hydroxyapatite (HA) bone repair material and to investigate the synergistic effects of superparamagnetic HA and a static magnetic field (SMF) on the promotion of osteogenesis, herein a new type of superparamagnetic/upconversion-generating HA material (HYH-Fe) is developed via a two-step doping method, as well as a specially-designed titanium implant with a built-in magnet to provide a local static magnetic field in vivo. The results show that the prepared HYH-Fe material maintains the crystal structure of HA and exhibits good cytocompatibility. The combined use of the superparamagnetic HYH-Fe material and SMF can effectively and synergistically promote osteogenesis/osteointegration surrounding the Ti implants. In addition, the HYH-Fe material exhibits distinct advantages in terms of both long-term fluorescence tracking and microcomputed tomography (micro-CT) tracking. The new material and tracking strategy in this study provide scientific feasibility and will have important clinical value for long-term tracking and evaluation of implanted materials and the bone repair effect.


Asunto(s)
Durapatita/química , Nanopartículas de Magnetita/química , Prótesis e Implantes , Titanio/farmacología , Animales , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Fluorescencia , Regulación de la Expresión Génica/efectos de los fármacos , Humanos , Imagenología Tridimensional , Nanopartículas de Magnetita/ultraestructura , Espectroscopía de Fotoelectrones , Conejos , Termodinámica , Difracción de Rayos X , Microtomografía por Rayos X
14.
Inorg Chem ; 57(21): 13739-13748, 2018 Nov 05.
Artículo en Inglés | MEDLINE | ID: mdl-30353726

RESUMEN

The intracellular interaction between osteoblasts and hydroxyapatite (HA) is of great importance for future applications of HA nanocrystals in tracing cell differentiation and bone regeneration. This research attempts to provide insight into the intracellular interaction between osteoblasts and synthetic HA nanocrystals by employing the uniform shape and fluorescence of terbium-doped HA nanocrystals jointly for the first time. When cultured for 7 days, the abundant cytoplasm of the osteoblasts could be clearly and homogeneously visualized via the green fluorescence of the internalized HA nanocrystals, which kept a uniform morphology but showed a slight size decrease and degradation; the gene expression of the osteoblasts was not obviously affected. However, on day 14, the uniform HA nanocrystals had degraded into smaller and irregular nanoparticles, and agglomeration had occurred. Meanwhile, multilayer membrane structures and vacuolization around the degraded HA particles appeared in the osteoblasts; the expression of genes largely decreased, or the genes could not be normally expressed. The results indicate that the morphology and composition change of the internalized HA nanocrystals and the microstructure change of the osteoblasts are closely related and correspond to each other. The feasible new method and insightful details will aid in future investigations of the interaction of synthetic HA nanocrystals with various cells. The results from the intracellular interaction also remind us to pay more attention to the in-depth study of HA nanoparticles used for bone repair and reconstruction.


Asunto(s)
Durapatita/química , Fluorescencia , Nanopartículas/química , Imagen Óptica , Animales , Microscopía Electrónica de Transmisión , Osteoblastos/citología , Tamaño de la Partícula , Ratas , Propiedades de Superficie
15.
Small ; 13(31)2017 08.
Artículo en Inglés | MEDLINE | ID: mdl-28640522

RESUMEN

Adsorption and activation of molecules on a surface holds the key to heterogeneous catalysis toward aerobic oxidative reactions. To achieve high catalytic activities, a catalyst surface should be rationally tailored to interact with both organic substrates and oxygen molecules. Here, a facile bottom-up approach to defective tungsten oxide hydrate (WO3 ·H2 O) nanosheets that contain both surface defects and lattice water is reported. The defective WO3 ·H2 O nanosheets exhibit excellent catalytic activity for aerobic coupling of amines to imines. The investigation indicates that the oxygen vacancies derived from surface defects supply coordinatively unsaturated sites to adsorb and activate oxygen molecules, producing superoxide radicals. More importantly, the Brønsted acid sites from lattice water can contribute to enhancing the adsorption and activation of alkaline amine molecules. The synergistic effect of oxygen vacancies and Brønsted acid sites eventually boosts the catalytic activity, which achieves a kinetic rate constant of 0.455 h-1 and a turnover frequency of 0.85 h-1 at 2 h, with the activation energy reduced to ≈35 kJ mol-1 . This work provides a different angle for metal oxide catalyst design by maneuvering subtle structural features, and highlights the importance of synergistic effects to heterogeneous catalysts.

16.
Molecules ; 22(5)2017 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-28481233

RESUMEN

Europium (Eu)-doped fluorapatite (FA) nanorods have a biocompatibility similar to that of hydroxyapatite (HA) for use as cell imaging biomaterials due to their luminescent property. Here, we discuss the new application of europium-doped fluorapatite (Eu-FA) nanorods as an anticancer drug carrier. The Eu-FA nanorods were prepared by using a hydrothermal method. The morphology, crystal structure, fluorescence, and composition were investigated. The specific crystal structure enables the effective loading of drug molecules. Doxorubicin (DOX), which was used as a model anticancer drug, effectively loaded onto the surface of the nanorods. The DOX release was pH-dependent and occurred more rapidly at pH 5.5 than at pH 7.4. The intracellular penetration of the DOX-loaded Eu-FA nanorods (Eu-FA/DOX) can be imaged in situ due to the self-fluorescence property. Treatment of melanoma A375 cells with Eu-FA/DOX elicited a more effective apoptosis rate than direct DOX treatment. Overall, Eu-FA exhibits potential for tracking and treating tumors and may be potentially useful as a multifunctional carrier system to effectively load and sustainably deliver drugs.


Asunto(s)
Apatitas/química , Doxorrubicina/farmacocinética , Portadores de Fármacos/química , Europio/química , Nanotubos/química , Apoptosis/efectos de los fármacos , Línea Celular , Supervivencia Celular/efectos de los fármacos , Doxorrubicina/química , Liberación de Fármacos , Humanos , Cinética , Luminiscencia , Imagen Óptica/métodos , Tamaño de la Partícula , Porosidad , Propiedades de Superficie
17.
Molecules ; 22(7)2017 Jun 23.
Artículo en Inglés | MEDLINE | ID: mdl-28644388

RESUMEN

With the increasing interest in hydroxyapatite (HA) nanostructures for use in biomedicine, the systematic evaluation of their potential effects on biological systems is becoming critically important. In this work, we report the in vitro cellular uptake, in vivo tissue distributions and toxicity of Tb3+-doped HA (HA-Tb) after short-, intermediate-, and long-term exposure. Transmission electron microscopy analysis indicated that HA-Tb was taken up by cells via vesicle endocytosis. Cell proliferation and cytotoxicity assay, combined with confocal laser scanning microscopy, indicated excellent cell viability with no changes in cell morphology at the examined doses. Three HA-Tb delivery methods (intraperitoneal, intragastric, and intravenous) resulted in similar time-dependent tissue distributions, while intraperitoneal injection produced the highest bioavailability. HA-Tb initially accumulated in livers and intestines of rats (4 h to one day after administration), then became increasingly distributed in the kidney and bladder (seven days), and finally decreased in all tissues after 30 to 90 days. No histopathological abnormalities or lesions related to treatment with HA-Tb were observed. These results suggest that HA-Tb has minimal in vitro and in vivo toxicity, regardless of the delivery mode, time, and dose. The findings provide a foundation for the design and development of HA for biological applications.


Asunto(s)
Durapatita/farmacocinética , Nanotubos , Terbio/farmacocinética , Células 3T3 , Animales , Disponibilidad Biológica , Masculino , Espectrometría de Masas , Ratones , Ratones Endogámicos BALB C , Microscopía Confocal , Ratas , Distribución Tisular , Difracción de Rayos X
18.
J Am Chem Soc ; 138(28): 8928-35, 2016 07 20.
Artículo en Inglés | MEDLINE | ID: mdl-27351805

RESUMEN

Modern development of chemical manufacturing requires a substantial reduction in energy consumption and catalyst cost. Sunlight-driven chemical transformation by metal oxides holds great promise for this goal; however, it remains a grand challenge to efficiently couple solar energy into many catalytic reactions. Here we report that defect engineering on oxide catalyst can serve as a versatile approach to bridge light harvesting with surface reactions by ensuring species chemisorption. The chemisorption not only spatially enables the transfer of photoexcited electrons to reaction species, but also alters the form of active species to lower the photon energy requirement for reactions. In a proof of concept, oxygen molecules are activated into superoxide radicals on defect-rich tungsten oxide through visible-near-infrared illumination to trigger organic aerobic couplings of amines to corresponding imines. The excellent efficiency and durability for such a highly important process in chemical transformation can otherwise be virtually impossible to attain by counterpart materials.

19.
ISA Trans ; 147: 489-500, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38395719

RESUMEN

This paper proposes a composite sliding mode control (SMC) to optimize the tracking performance and the anti-disturbance performance of permanent magnet synchronous machine (PMSM) speed regulation systems. The differential term in the control law can magnify the measurement noise, resulting in more discontinuity. To filter out the high frequency noise and make the control law smoother, the first-order differentiator (FOD) is employed to estimate the speed error and its derivative. Since the feedforward compensation can improve the robustness of the system, a disturbance observer (DOB) based on the sliding mode observer (SMO) is designed to reinforce the dynamic performance under disturbance variation. Under the effect of the feedforward compensation, chattering can be further weakened by decreasing the switching gain appropriately. Finally, the effectiveness of the proposed methods is confirmed by various experimental results.

20.
Food Chem ; 452: 139532, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38705120

RESUMEN

This study aimed to better understand whether and how the reactive 1,2-dicarbonyl precursors of advanced glycation end products (AGEs), glyoxal (GO) and methylglyoxal (MGO), cross the intestinal barrier by studying their transport in the in vitro Caco-2 transwell system. The results reveal that GO, MGO and Nε-(carboxymethyl)lysine (CML), the latter studied for comparison, are transported across the intestinal cell layer via both active and passive transport and accumulate in the cells, albeit all to a limited extent. Besides, the transport of the dicarbonyl compounds was only partially affected by the presence of amino acids and protein, suggesting that scavenging by a food matrix will not fully prevent their intestinal absorption. Our study provides new insights into the absorption of the two major food-borne dicarbonyl AGE precursors and provides evidence of their potential systemic bioavailability but also of factors limiting their contribution to the overall exposome.


Asunto(s)
Productos Finales de Glicación Avanzada , Glioxal , Piruvaldehído , Humanos , Células CACO-2 , Productos Finales de Glicación Avanzada/metabolismo , Productos Finales de Glicación Avanzada/química , Piruvaldehído/metabolismo , Glioxal/metabolismo , Glioxal/química , Modelos Biológicos , Transporte Biológico , Absorción Intestinal
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