RESUMEN
The efficiency of establishing pig pluripotent embryonic stem cell clones from blastocysts is still low. The transcription factor Nanog plays an important role in maintaining the pluripotency of mouse and human embryonic stem cells. Adequate activation of Nanog has been reported to increase the efficiency of establishing mouse embryonic stem cells from 3.5 day embryos. In mouse, Nanog starts to be strongly expressed as early as the morula stage, whereas in porcine NANOG starts to be strongly expressed by the late blastocyst stage. Therefore, here we investigated both the effect of expressing NANOG on porcine embryos early from the morula stage and the efficiency of porcine pluripotent embryonic stem cell clone formation. Compared with intact porcine embryos, NANOG overexpression induced a lower blastocyst rate, and did not show any advantages for embryo development and pluripotent embryonic stem cell line formation. These results indicated that, although NANOG is important pluripotent factor, NANOG overexpression is unnecessary for the initial formation of porcine pluripotent embryonic stem cell clones in vitro.
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Células Madre Pluripotentes , Animales , Blastocisto , Desarrollo Embrionario , Células Madre Embrionarias , Femenino , Ratones , Mórula , Embarazo , PorcinosRESUMEN
The inner cell mass (ICM) in blastocyst is the origin of all somatic and germ cells in mammals and pluripotent stem cells (PSCs) in vitro. As the conserved principles between pig and human, here we performed comprehensive single-cell RNA-seq for porcine early embryos from oocyte to early blastocyst (EB). We show the specification of the ICM and trophectoderm in morula and the molecular signature of the precursors. We demonstrate the existence of naïve pluripotency signature in morula and ICM of EB, and the specific pluripotent genes and the activity of signalling pathways highlight the characteristics of the naïve pluripotency. We observe the absence of dosage compensation with respect to X-chromosome (XC) in morula, and incomplete dosage compensation in the EB. However, the dynamics of dosage compensation may be independent of the expression of XIST induced XC inactivation. Our study describes molecular landmarks of embryogenesis in pig that will provide a better strategy for derivation of porcine PSCs and improve research in regenerative medicine.
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Blastocisto/citología , Linaje de la Célula , Regulación del Desarrollo de la Expresión Génica/genética , Estratos Germinativos/citología , Oocitos/citología , Animales , Perfilación de la Expresión Génica/métodos , Células Germinativas/citología , Células Madre Pluripotentes/citología , Porcinos , Inactivación del Cromosoma X/fisiologíaRESUMEN
Fusion of differentiated somatic cells with pluripotent stem cells can be used for cellular reprogramming, but the efficiency to obtain hybrid cells is extremely low. Here, we explored a novel cell fusion system, termed single-cell fusion, the efficiency was significantly improved verified by fusion of mouse embryonic stem cells (mESCs), comparing to traditional polyethylene glycol fusion. Then, we employed the optimized system to perform cell fusion of porcine embryonic fibroblasts (PEFs) and porcine pluripotent stem cells (pPSCs) with mESCs. The hybrid cells showed both red and green fluorescence and expressed species-specific genes of mouse and pig to evidence that the fusion was successful. The hybrid cells displayed characteristics similar with mESCs, including colony morphology, alkaline phosphatase positive and formation of embryoid body, and the expressions of core pluripotent factors OCT4, NANOG, and SOX2 of the pig were induced in the mESC/PEF hybrid cells. The results indicate PEFs and pPSCs could be reprogrammed by mESCs via the single-cell fusion. Taking advantage of the hybrid cells to investigate the signaling pathways depended on the pluripotency of pig, we suggest the transforming growth factor-ß signaling pathways may play important roles. In summary, the single-cell fusion is highly efficient, and we believe in the future it will be widely used in the application and fundamental research.
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Comunicación Celular/genética , Diferenciación Celular/genética , Reprogramación Celular/genética , Células Madre Embrionarias de Ratones/citología , Animales , Fusión Celular/métodos , Línea Celular , Fibroblastos/citología , Células Madre Pluripotentes Inducidas/citología , Ratones , Células Madre Embrionarias de Ratones/metabolismo , Células Madre Pluripotentes/citología , PorcinosRESUMEN
Tetracycline hydrochloride (TCH), as a typical antibiotic-pollutant, is desired to enhance its removal from public environment, due to its toxicity and persistence. Microbial electrochemical technology (MET) is a series complex microorganisms-driven processes with characteristics of simultaneous wastewater treatment and electricity generation. The study was presented to evaluate the TCH removal behavior and power generation performance through the co-metabolism under constant glucose with different TCH concentrations using MET. It was found that the TCH removal efficiency arrived at 40% during the first 6â¯h, when TCH concentrations ranged from 1 to 50â¯mg/L. It was interesting that TCH degradation rate increased to a maximum of 4.15â¯×â¯10-2 h-1 with its concentrations varying from 1 to 20â¯mg/L, however, the further increase to 50â¯mg/L in TCH concentration resulted in a reverse 66% reduction. In the meantime, the generated bioelectricity declared a similar fluctuation trend with a maximum power density of 600â¯mW/m2 under the condition of 20â¯mg/L TCH co-degradation with glucose. What's more, the TCH inhibition effect fitted well with Haldane's model, indicating that the microbial electrochemical system had a better potency toward TCH toxicity than that reported (EC50â¯=â¯2.2â¯mg/L). Thauera as mainly functional aromatics-degrading bacteria and Bdellovibrio against bacterial pathogens, only existed in the mixed cultures with TCH and glucose, indicating extremely remarkable changes in bacterial community with TCH addition. In summary, a new approach for the anaerobic biodegradation of TCH was explored through co-metabolism with glucose using MET. The results should be useful for antibiotics wastewater disposal of containing TCH.
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Biodegradación Ambiental , Fuentes de Energía Bioeléctrica/microbiología , Microbiota , Tetraciclina/aislamiento & purificación , Eliminación de Residuos Líquidos/métodos , Contaminantes del Agua/aislamiento & purificación , Antibacterianos/aislamiento & purificación , Antibacterianos/metabolismo , Bacterias/clasificación , Bacterias/genética , Bacterias/aislamiento & purificación , Bacterias/metabolismo , Electricidad , Cinética , Tetraciclina/metabolismo , Contaminantes del Agua/metabolismoRESUMEN
SOX2 (sex determining region Y-box2) is one of the critical pluripotent factors that play a crucial role in the first lineage differentiation and maintenance of pluripotency in inner cell mass during early embryonic development. However, there are few researches about the regulation of the SOX2 promoter, especially in Sus scrofa. To analyzed the activity of SOX2 promoter in early porcine embryos, we determined the control system and established the microinjection system for assessing SOX2 promoter activity by analyzing the embryonic development and the expression of enhanced green fluorescence protein (EGFP) after micro-injected different EGFP plasmids at different times after activation of the oocytes. Then, we analyzed the structure of 5000 bp upstream of the SOX2 translation initiation site and found there were four transcription factor binding site clusters. Next, we designed and constructed promoter-containing plasmids to analyze the function of each cluster. To detect the activity of different promoters, we assessed the mCherry expression in protein levels and mRNA levels by analyzing the mCherry fluorescence intensity and qRT-PCR after injecting plasmids into embryos. These results showed that the activity of the shorted promoter, with the region from 2254 bp to 2442 bp upstream of translation initiation site deleted, decreased to 17.8% at 4-cell and 8-cell stages compared with the full-length promoter. This region included two NF-AT transcription factor binding sites, which indicated that the NF-AT binding site is a key region to regulate the activity of the SOX2 promoter. The results provide important data for determination the mechanism of porcine SOX2 regulation.
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Desarrollo Embrionario , Regulación del Desarrollo de la Expresión Génica , Regiones Promotoras Genéticas , Factores de Transcripción SOXB1/genética , Animales , Sitios de Unión , Diferenciación Celular , Embrión de Mamíferos , Proteínas Fluorescentes Verdes , Factores de Transcripción NFATC , Plásmidos , PorcinosRESUMEN
BACKGROUND/AIMS: Uncaria rhynchophylla, known as "Gou-teng", is a traditional Chinese medicine (TCM) used to extinguish wind, clear heat, arrest convulsions, and pacify the liver. Although U. rhynchophylla has a long history of being often used to treat central nervous system (CNS) diseases, its efficacy and potential mechanism are still uncertain. This study investigated neuroprotective effect and the underlying mechanism of U. rhynchophylla extract (URE) in MPP+-induced SH-SY5Y cells and MPTP-induced mice. METHODS: MPP+-induced SH-SY5Y cells and MPTP-induced mice were used to established Parkinson's disease (PD) models. Quantitative proteomics and bioinformatics were used to uncover proteomics changes of URE. Western blotting was used to validate main differentially expressed proteins and test HSP90 client proteins (apoptosis-related, autophagy-related, MAPKs, PI3K, and AKT proteins). Flow cytometry and JC-1 staining assay were further used to confirm the effect of URE on MPP+-induced apoptosis in SH-SY5Y cells. Gait analysis was used to detect the behavioral changes in MPTP-induced mice. The levels of dopamine (DA) and their metabolites were examined in striatum (STR) by HPLC-EC. The positive expression of tyrosine hydroxylase (TH) was detected by immunohischemical staining and Western blotting. RESULTS: URE dose-dependently increased the cell viability in MPP+-induced SH-SY5Y cells. Quantitative proteomics and bioinformatics results confirmed that HSP90 was an important differentially expressed protein of URE. URE inhibited the expression of HSP90, which further reversed MPP+-induced cell apoptosis and autophagy by increasing the expressions of Bcl-2, Cyclin D1, p-ERK, p-PI3K p85, PI3K p110α, p-AKT, and LC3-I and decreasing cleaved caspase 3, Bax, p-JNK, p-p38, and LC3-II. URE also markedly decreased the apoptotic ratio and elevated mitochondrial transmembrane potential (DΨm). Furthermore, URE treatment ameliorated behavioral impairments, increased the contents of DA and its metabolites and elevated the positive expressions of TH in SN and STR as well as the TH protein. CONCLUSIONS: URE possessed the neuroprotective effect in vivo and in vitro, regulated MAPK and PI3K-AKT signal pathways, and inhibited the expression of HSP90. U. rhynchophylla has potentials as therapeutic agent in PD treatment.
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Medicamentos Herbarios Chinos/farmacología , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Proteínas HSP90 de Choque Térmico/biosíntesis , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Fármacos Neuroprotectores/farmacología , Trastornos Parkinsonianos , Uncaria/química , Animales , Línea Celular Tumoral , Medicamentos Herbarios Chinos/química , Humanos , Ratones , Fármacos Neuroprotectores/química , Trastornos Parkinsonianos/tratamiento farmacológico , Trastornos Parkinsonianos/metabolismo , Trastornos Parkinsonianos/patología , ProteómicaRESUMEN
Upregulation of Cdx2 expression in outer cells is a key event responsible for cell lineage segregation between the inner cell mass and the trophoderm (TE) in mouse morula-stage embryos. In TE cells, polarization can regulate Hippo and Rho-associated kinase (Rho-ROCK) signaling to induce the nuclear location of YAP, which has been demonstrated to further induce the expression of Cdx2. However, we found that CDX2 expression could not be detected in the outer cells of porcine morula-stage embryos but only in some TE cells at the early blastocyst stage. The biological significance and the regulation mechanism of this species-specific CDX2 expression pattern have still not been determined. We show here that an asynchronous CDX2 expression pattern exists in porcine TE cells during the development of the blastocyst. We demonstrate that CDX2 expression in porcine TE cells depends on the nuclear localization of YAP and polarization of the embryo through Y27632 treatment. We found that the polarization process in the morula to the late blastocyst stage porcine embryos was asynchronous, which was revealed by the apical localization of phosphorylated EZRIN staining. Artificially enhancing the number of polarized blastomeres by culturing the separated blastomeres of four-cell stage porcine embryos resulted in increased CDX2-positive cell numbers. These results indicate that the mechanism of CDX2 expression regulation is conserved, but the polarization progress is not conserved between the pig and the mouse, and results in a species-specific trophoblast determination progress model.
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Blastocisto/metabolismo , Blastómeros/metabolismo , Factor de Transcripción CDX2/biosíntesis , Mórula/metabolismo , Factores de Transcripción SOXB1/biosíntesis , Trofoblastos/metabolismo , Amidas/farmacología , Animales , Linaje de la Célula , Células Cultivadas , Proteínas del Citoesqueleto/metabolismo , Técnicas de Cultivo de Embriones , Embrión de Mamíferos/metabolismo , Regulación del Desarrollo de la Expresión Génica , Ratones , Fosforilación , Proteínas Proto-Oncogénicas c-yes/metabolismo , Piridinas/farmacología , Porcinos , Quinasas Asociadas a rho/metabolismoRESUMEN
A Gram-stain-negative, strictly aerobic, yellow-coloured, motile by gliding and elongated rod-shaped bacterial strain, designated SYP-B1015T, was isolated from the rhizosphere of Artemisia annua L. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SYP-B1015T belonged to the genus Flavobacterium and had highest 16S rRNA gene sequence similarity to Flavobacterium compostarboris JCM 16527T (98.1â%) and Flavobacterium procerum JCM 30113T (97.2â%). The predominant respiratory quinone for the strain was MK-6, and the major cellular fatty acids were iso-C15â:â0, iso-C15â:â0 3-OH and iso-C17â:â0 3-OH. The polar lipid profile contained phosphatidylethanolamine as a major compound. The DNA G+C content of strain SYP-B1015T was 33.5 mol%. The DNA-DNA relatedness values between strain SYP-B1015T and F. compostarboris JCM 16527T and F. procerum JCM 30113T were 56.5±0.4 and 48.9±1.2â%, respectively. Combining the data from morphological, physiological, biochemical and chemotaxonomic characterizations presented in this study, strain SYP-B1015T represents a novel species of the genus Flavobacterium, for which the name Flavobacterium artemisiae sp. nov. is proposed. The type strain is SYP-B1015T (=CGMCC 1.16115T=KCTC 62025T).
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Artemisia annua/microbiología , Flavobacterium/clasificación , Filogenia , Rizosfera , Técnicas de Tipificación Bacteriana , Composición de Base , China , ADN Bacteriano/genética , Ácidos Grasos/química , Flavobacterium/genética , Flavobacterium/aislamiento & purificación , Fosfatidiletanolaminas/química , Pigmentación , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/análogos & derivados , Vitamina K 2/químicaRESUMEN
Eighteen secondary metabolites were isolated from the fermentation broth of the endophytic fungus Xylaria sp. SYPF 8246, including four new compounds, xylarianins A-D (1-4), three new natural products, 6-methoxycarbonyl-2'-methyl-3,5,4',6'-tetramethoxy-diphenyl ether (5), 2-chlor-6-methoxycarbonyl-2'-rnethyl-3,5,4',6'-tetramethoxy-diphenyl ether (6), and 2-chlor-4'-hydroxy-6-methoxy carbonyl-2'-methyl-3,5,6'-trimethoxy-diphenyl ether (7), and eleven known compounds (8-18). Their structural elucidations were conducted by using 1D and 2D NMR, HRESIMS, and Rh2(OCOCF3)4-induced electronic circular dichroism (ECD) spectra analyses. The integrated 1H and 13C NMR data of three new natural products 5-7 were reported for the first time. All the isolated compounds were assayed for their inhibitory activities against human carboxylesterase 2 (hCE 2). Compounds 1, 5-9, and 18 displayed significant inhibitory activities against hCE 2 with IC50 values of 10.43⯱â¯0.51, 6.69⯱â¯0.85, 12.36⯱â¯1.27, 18.25⯱â¯1.78, 29.78⯱â¯0.48, 18.86⯱â¯1.87, and 20.72⯱â¯1.51⯵M, respectively. The interactions between compounds 1 and 5 with hCE 2 were anaylzed by molecular docking.
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Benzofenonas/química , Carboxilesterasa/antagonistas & inhibidores , Succinatos/química , Xylariales/química , Benzofenonas/aislamiento & purificación , Carboxilesterasa/química , Dominio Catalítico , Humanos , Cinética , Simulación del Acoplamiento Molecular , Metabolismo Secundario , Succinatos/aislamiento & purificación , Xylariales/metabolismoRESUMEN
A novel 1(2), 2(18)-diseco indole diterpenoid, drechmerin H (1), was isolated from the fermentation broth of Drechmeria sp. together with a new indole diterpenoid, 2'-epi terpendole A (3), and a known analogue, terpendole A (2). Their structures were determined by HRESIMS, 1D and 2D NMR, ECD, and X-ray single crystal diffraction analyses as well as quantum chemical calculation. The abosulte configuration of terpendole A (2) was determined for the first time. Compound 1 displayed the significant agonistic effect on pregnane X receptor (PXR) with EC50 value of 134.91⯱â¯2.01â¯nM, and its interaction with PXR was investigated by molecular docking. Meantime, a plausible biosynthetic pathway for compounds 1-3 is also discussed in the present work.
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Productos Biológicos/farmacología , Diterpenos/farmacología , Hypocreales/química , Indoles/farmacología , Receptor X de Pregnano/agonistas , Productos Biológicos/química , Productos Biológicos/aislamiento & purificación , Diterpenos/química , Diterpenos/aislamiento & purificación , Relación Dosis-Respuesta a Droga , Células Hep G2 , Humanos , Indoles/química , Indoles/aislamiento & purificación , Estructura Molecular , Relación Estructura-ActividadRESUMEN
A Gram-stain-positive, aerobic actinobacterial strain (designated SYP-A7299T), which displayed a rod-coccus growth lifecycle, was isolated from the rhizosphere of Ginkgo biloba L. Phylogenetic analyses based on 16S rRNA gene sequences indicated that strain SYP-A7299T belongs to the genus Arthrobacter and is most closely related to Arthrobacter halodurans JSM 078085T (97.4â% 16S rRNA gene sequence similarity). The DNA-DNA relatedness value between strain SYP-A7299T and A. halodurans JSM 078085T was 37â% ±2.9. The cell-wall peptidoglycan was A4α, and glucose and galactose were whole-cell sugars. The polar lipids consisted of diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol, two glycolipids and an unknown polar lipid. The major menaquinone were MK-8(H2) (72â%) and MK-9(H2) (28â%), and the predominant cellular fatty acids were anteiso-C15 : 0, iso-C15 : 0 and anteiso-C17 : 0. The DNA G+C content was 68.9 mol%. Based on the morphological, physiological, biochemical and chemotaxonomic characters presented in this study, strain SYP-A7299T represents a novel species of the genus Arthrobacter, for which the name Arthrobacter ginkgonis sp. nov. is proposed. The type strain is SYP-A7299T (=DSM 100491T=KCTC 39â592T).
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Arthrobacter/clasificación , Ginkgo biloba/microbiología , Filogenia , Rizosfera , Microbiología del Suelo , Arthrobacter/genética , Arthrobacter/aislamiento & purificación , Técnicas de Tipificación Bacteriana , Composición de Base , Pared Celular/química , China , ADN Bacteriano/genética , Ácidos Grasos/química , Glucolípidos/química , Hibridación de Ácido Nucleico , Peptidoglicano/química , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN , Vitamina K 2/químicaRESUMEN
In this study, two mixed-mode chromatography stationary phases (C8SAX and C8SCX) were evaluated and used to establish a two-dimensional liquid chromatography system for the separation of traditional Chinese medicine. The chromatographic properties of the mixed-mode columns were systematically evaluated by comparing with other three columns of C8, strong anion exchanger, and strong cation exchanger. The result showed that C8SAX and C8SCX had a mixed-mode retention mechanism including electrostatic interaction and hydrophobic interaction. Especially, they were suitable for separating acidic and/or basic compounds and their separation selectivities could be easily adjusted by changing pH value. Then, several off-line 2D-LC systems based on the C8SAX in the first dimension and C8SAX, C8SCX, or C8 columns in the second dimension were developed to analyze a traditional Chinese medicine-Uncaria rhynchophylla. The two-dimensional liquid chromatography system of C8SAX (pH 3.0) × C8SAX (pH 6.0) exhibited the most effective peak distribution. Finally, fractions of U. rhynchophylla prepared from the first dimension were successfully separated on the C8SAX column with a gradient pH. Thus, the mixed-mode stationary phase could provide a platform to separate the traditional Chinese medicine in practical applications.
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Medicamentos Herbarios Chinos/aislamiento & purificación , Medicina Tradicional China , Uncaria/química , Cromatografía Liquida , Medicamentos Herbarios Chinos/química , Concentración de Iones de HidrógenoRESUMEN
The C9-position of quinine was modified by meta- or para-substituted benzo-18-crown-6, and immobilized on 3-mercaptopropyl-modified silica gel through the radical thiol-ene addition reaction. These two chiral stationary phases were evaluated by chiral acids, amino acids, and chiral primary amines. The crown ether moiety on the quinine anion exchanger provided a ligand-exchange site for primary amino groups, which played an important role in the retention and enantioselectivity for chiral compounds containing primary amine groups. These two stationary phases showed good selectivity for some amino acids. The complex interaction between crown ether and protonated primary amino group was investigated by the addition of inorganic salts such as LiCl, NH4Cl, NaCl, and KCl to the mobile phase. The resolution results showed that the simultaneous interactions between two function moieties (quinine and crown ether) and amino acids were important for the chiral separation.
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Éteres Corona/química , Quinina/química , Cromatografía Líquida de Alta Presión , Espectrofotometría Ultravioleta , EstereoisomerismoRESUMEN
To improve the chiral recognition capability of a cinchona alkaloid crown ether chiral stationary phase, the crown ether moiety was modified by the chiral group of (1S, 2S)-2-aminocyclohexyl phenylcarbamate. Both quinine and quinidine-based stationary phases were evaluated by chiral acids, chiral primary amines and amino acids. The quinine/quinidine and crown ether provided ion-exchange sites and complex interaction site for carboxyl group and primary amine group in amino acids, respectively, which were necessary for the chiral discrimination of amino acid enantiomers. The introduction of the chiral group greatly improved the chiral recognition for chiral primary amines. The structure of crown ether moiety was proved to play a dominant role in the chiral recognitions for chiral primary amines and amino acids.
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Oct4 is exclusively expressed in rodent inner cell mass (ICM) but silenced in its trophectoderm (TE). However, for many non-rodent animals, including pig, cattle, rabbit, goat, and human, OCT4 has a remarkable expression in early TE. This study, applying pig as the main research model, proves that OCT4 expression in TE is supported by a unique GATA motif in the OCT4 upstream conserved regulatory region, and GATA4 is responsible for its activation. Moreover, OCT4 acts as a specific regulator of a narrow range of genes (including BCL2A1 and HNRNP2AB1) that are essential for the first wave of rapid proliferation in early TE. This study describes the regulatory mechanism to direct the OCT4 expression and its significance in TE of porcine preimplantation embryo.
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Blastocisto , Roedores , Humanos , Porcinos , Animales , Bovinos , ConejosRESUMEN
Additive manufacturing, with its rapid advances in materials science, allows for researchers and companies to have the ability to create novel formulations and final parts that would have been difficult or near impossible to fabricate with traditional manufacturing methods. One such 3D printing technology, direct ink writing, is especially advantageous in fields requiring customizable parts with high amounts of functional fillers. Nuclear technology is a prime example of a field that necessitates new material design with regard to unique parts that also provide radiation shielding. Indeed, much effort has been focused on developing new rigid radiation shielding components, but DIW remains a less explored technology with a lot of potential for nuclear applications. In this study, DIW formulations that can behave as radiation shields were developed and were printed with varying amounts of porosity to tune the thermomechanical performance.
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Primarily used as an encapsulant and soft adhesive, Sylgard 184 is an engineered, high-performance silicone polymer that has applications spanning microfluidics, microelectromechanical systems, mechanobiology, and protecting electronic and non-electronic devices and equipment. Despite its ubiquity, there are improvements to be considered, namely, decreasing its gel point at room temperature, understanding volatile gas products upon aging, and determining how material properties change over its lifespan. In this work, these aspects were investigated by incorporating well-defined compounds (the Ashby-Karstedt catalyst and tetrakis (dimethylsiloxy) silane) into Sylgard 184 to make modified formulations. As a result of these additions, the curing time at room temperature was accelerated, which allowed for Sylgard 184 to be useful within a much shorter time frame. Additionally, long-term thermal accelerated aging was performed on Sylgard 184 and its modifications in order to create predictive lifetime models for its volatile gas generation and material properties.
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The growing need for the implementation of stretchable biosensors in the body has driven rapid prototyping schemes through the direct ink writing of multidimensional functional architectures. Recent approaches employ biocompatible inks that are dispensable through an automated nozzle injection system. However, their application in medical practices remains challenged in reliable recording due to their viscoelastic nature that yields mechanical and electrical hysteresis under periodic large strains. Herein, we report sponge-like poroelastic silicone composites adaptable for high-precision direct writing of custom-designed stretchable biosensors, which are soft and insensitive to strains. Their unique structural properties yield a robust coupling to living tissues, enabling high-fidelity recording of spatiotemporal electrophysiological activity and real-time ultrasound imaging for visual feedback. In vivo evaluations of custom-fit biosensors in a murine acute myocardial infarction model demonstrate a potential clinical utility in the simultaneous intraoperative recording and imaging on the epicardium, which may guide definitive surgical treatments.
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Técnicas Biosensibles/instrumentación , Técnicas Biosensibles/métodos , Diagnóstico por Imagen/métodos , Infarto del Miocardio/diagnóstico por imagen , Pericardio/diagnóstico por imagen , Animales , Materiales Biocompatibles/química , Línea Celular , Modelos Animales de Enfermedad , Electrocardiografía , Fenómenos Electrofisiológicos , Procesamiento de Imagen Asistido por Computador , Tinta , Masculino , Ratones , Ratones Endogámicos C57BL , Simulación de Dinámica Molecular , Mioblastos/metabolismo , Mioblastos/patología , Prótesis e Implantes , Siliconas/química , Análisis Espacio-Temporal , Porcinos , UltrasonografíaRESUMEN
Precious group metal (PGM) catalysts such as Pt supported on carbon supports are expensive catalysts utilized for the oxygen reduction reaction (ORR) due to their unmatched catalytic activity and durability. As an alternative, PGM-free ORR electrocatalysts that offer respectable catalytic activity are being pursued. Most of the notable PGM-free catalysts are obtained either from a bottom-up approach synthesis utilizing nitrogen-rich polymers as building blocks, or from a top down approach, where nitrogen and metal moieties are incorporated to carbonaceous matrixes. The systematic understanding of the origin of catalytic activity for either case is speculative and currently employed synthesis techniques typically generate large amounts of hazardous waste such as acids, oxidizing agents, and solvents. Herein, for the first time, we investigate the catalytic activity of graphite-based materials obtained via intercalation strategies that minimally perturb the graphitic backbone. Our outlined approaches demonstrate initial efforts to not only elucidate the role of each element but also significantly reduce the use of hazardous chemicals, which remains a pressing challenge. Graphite intercalation compounds (GIC) were obtained using fewer steps and solvent-free processes. X-ray diffraction and Raman results confirm the successful intercalation of FeCl3 between graphite layers. Electrochemical data shows that the ORR performance of FeCl3-intercalated GIC displays slight improvement where the onset potential reaches 0.77 V vs RHE in alkaline environments. However, expansion of the graphite and solvent-free incorporation of iron and nitrogen moieties resulted in a significant increase in ORR activity with onset potential to 0.89 V vs RHE, a maximum half-wave of 0.72 V vs RHE, and a limiting current of about 2.5 mA cm-2. We anticipate that the use of near solvent-free processes that result in a high yield of catalysts along with the fundamental insight into the origin of electrochemical activity will tremendously impact the methodologies for developing next-generation ORR catalysts.
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A new protostane-type triterpenoid, 5ß,29-dihydroxy alisol A (1) was isolated from Alisma plantago-aquatica subsp. orientale (Sam.) Sam. as well as 12-deoxyphorbol-13α-pentadecanoate (2). We first report the presence of compound 2 in the genus Alisma. Their structures were established on the basis of 1D and 2D NMR, and HRESIMS spectroscopic analyses. All the isolated compounds were assayed for their inhibitory effects against human carboxylesterase 2 (HCE-2). Compounds 1 and 2 displayed inhibitory activities against HCE-2 with IC50 values of 29.2 and 4.6 µM, respectively. The interaction mechanisms of HCE-2 with compounds 1 and 2 were investigated by molecular docking, respectively.