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The energy transfer (ET) between organic molecules and semiconductors is a crucial mechanism for enhancing the performance of semiconductor-based optoelectronic devices, but it remains undiscovered. Here, ultrafast optical pump-probe spectroscopy was utilized to directly reveal the ET between organic Alq3 molecules and Si semiconductors. Ultrathin SiO2 dielectric layers with a thickness of 3.2-10.8 nm were inserted between Alq3 and Si to prevent charge transfer. By means of the ET from Alq3 to Si, the SiO2 thickness-dependent relaxation dynamics of photoexcited carriers in Si have been unambiguously observed on the transient reflectivity change (ΔR/R) spectra, especially for the relaxation process on a time scale of 200-350 ps. In addition, these findings also agree with the results of our calculation in a model of long-range dipole-dipole interactions, which provides critical information for developing future optoelectronic devices.
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An optical vector analyzer (OVA) based on orthogonal polarization interrogation and polarization diversity detection is widely used to measure an optical device's loss, delay, or polarization-dependent features. Polarization misalignment is the OVA's primary error source. Conventional offline polarization alignment using a calibrator greatly reduces the measurement reliability and efficiency. In this Letter, we propose an online polarization error suppression method using Bayesian optimization. Our measurement results are verified by a commercial OVA instrument that uses the offline alignment method. The OVA featuring online error suppression will be widely used in the production of optical devices, not just in the laboratory.
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A novel one-pot two-step multicomponent reaction has been achieved for the preparation of ß-CF3 enamines by using different aliphatic amines, propiolates, and CF3 SO2 Na as starting material. In this protocol, various aliphatic amines including primary amines, cyclic or acyclic secondary amines were demonstrated to be good coupling partners, and different ß-CF3 enamines were obtained in moderate to good yields. Among them, the primary aliphatic amines only gave pure (E)-ß-CF3 enamines as products. The synthetic utility of the MCRs strategy was further demonstrated by mild conditions, gram-scale synthesis and natural sunlight-induced protocol. Preliminary mechanistic studies suggest that this trifluoromethylation of C(sp2 )-H involves radical process.
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A green one-pot 2,3,6-trifunctionalization of N-alkyl/aryl indoles was achieved by adding three equivalents of N-Br sulfoximine to the indole solution. A variety of 2-sulfoximidoyl-3,6-dibromo indoles were prepared with 38-94% yields using N-Br sulfoximines as both brominating and sulfoximinating reagents. Based on the results of controlled experiments, we propose that a radical substitution involving 3,6-dibromination and 2-sulfoximination occurs in the reaction process. This is first time that 2,3,6-trifunctionalization of indole in one pot has been achieved.
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Musical emotions have received increasing attention over the years. To better recognize the emotions by brain-computer interface (BCI), the random music-playing and sequential music-playing experimental paradigms are proposed and compared in this paper. Two experimental paradigms consist of three positive pieces, three neutral pieces and three negative pieces of music. Ten subjects participate in two experimental paradigms. The features of electroencephalography (EEG) signals are firstly analyzed in the time, frequency and spatial domains. To improve the effect of emotion recognition, a recognition model is proposed with the optimal channels selecting by Pearson's correlation coefficient, and the feature fusion combining differential entropy and wavelet packet energy. According to the analysis results, the features of sequential music-playing experimental paradigm are more different among three emotions. The classification results of sequential music-playing experimental paradigm are also better, and its average results of positive, neutral and negative emotions are 78.53%, 72.81% and 77.35%, respectively. The more obvious the changes of EEG induced by the emotions, the higher the classification accuracy will be. After analyzing two experimental paradigms, a better way for music to induce the emotions can be explored. Therefore, our research offers a novel perspective on affective BCIs.
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Interfaces Cérebro-Computador , Eletroencefalografia , Emoções , Música , Humanos , Música/psicologia , Emoções/fisiologia , Eletroencefalografia/métodos , Masculino , Feminino , Adulto Jovem , Adulto , Encéfalo/fisiologia , Percepção Auditiva/fisiologia , Estimulação Acústica/métodosRESUMO
Chemo-immunotherapy has become a promising strategy for cancer treatment. However, the inability of the drugs to penetrate deeply into the tumor and form potent tumor vaccines in vivo severely restricts the antitumor effect of chemo-immunotherapy. In this work, an injectable sodium alginate platform is reported to promote penetration of the chemotherapeutic doxorubicin (DOX) and delivery of personalized tumor vaccines. The injectable multifunctional sodium alginate platform cross-links rapidly in the presence of physiological concentrations of Ca2+, forming a hydrogel that acts as a drug depot and releases loaded hyaluronidase (HAase), DOX, and micelles (IP-NPs) slowly and sustainedly. By degrading hyaluronic acid (HA) overexpressed in tumor tissue, HAase can make tumor tissue "loose" and favor other components to penetrate deeply. DOX induces potent immunogenic cell death (ICD) and produces tumor-associated antigens (TAAs), which could be effectively captured by polyethylenimine (PEI) coated IP-NPs micelles and form personalized tumor vaccines. The vaccines efficaciously facilitate the maturation of dendritic cells (DCs) and activation of T lymphocytes, thus producing long-term immune memory. Imiquimod (IMQ) loaded in the core could further activate the immune system and trigger a more robust antitumor immune effect. Hence, the research proposes a multifunctional drug delivery platform for the effective treatment of colorectal cancer.
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Alginatos , Doxorrubicina , Hidrogéis , Imunoterapia , Nanopartículas , Alginatos/química , Hidrogéis/química , Animais , Nanopartículas/química , Camundongos , Doxorrubicina/química , Doxorrubicina/farmacologia , Humanos , Vacinas Anticâncer/química , Vacinas Anticâncer/administração & dosagem , Hialuronoglucosaminidase/metabolismo , Micelas , Linhagem Celular TumoralRESUMO
In this paper, considering the hydrogen production cycle coupled with the supercritical CO2 cycle, hydrogen is produced as a clean fuel along with power and heat production. Also, the world's need for clean energy doubles the solutions to achieve clean hydrogen energy. The investigated cycle has a supercritical CO2 cycle with a combustion chamber where enriched fuel is introduced. Combustion products produce work in the gas turbine, and further hydrogen separation is formed with the help of water gas shift reaction and hydrogen separation membrane. In the thermodynamic analysis, combustion chamber known as the most irreversible member of set, where the most exergy is lost. The energy and exergy efficiency for whole set are 64.82%, 52.46% respectively. Produced hydrogen mass flow rate calculated 46.8 kg/h. Also, multi-objective optimization based on genetic algorithm were done and the results were reported. All calculation and optimization method has been done in MATLAB software.
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Dióxido de Carbono , Hidrogênio , Software , Termodinâmica , ÁguaRESUMO
Osteosarcoma (OS) is the most common primary malignant pediatric bone tumor and is characterized by high heterogeneity. Studies have revealed a wide range of phenotypic differences among OS cell lines in terms of their in vivo tumorigenicity and in vitro colony-forming abilities. However, the underlying molecular mechanism of these discrepancies remains unclear. The potential role of mechanotransduction in tumorigenicity is of particular interest. To this end, we tested the tumorigenicity and anoikis resistance of OS cell lines both in vitro and in vivo. We utilized a sphere culture model, a soft agar assay, and soft and rigid hydrogel surface culture models to investigate the function of rigidity sensing in the tumorigenicity of OS cells. Additionally, we quantified the expression of sensor proteins, including four kinases and seven cytoskeletal proteins, in OS cell lines. The upstream core transcription factors of rigidity-sensing proteins were further investigated. We detected anoikis resistance in transformed OS cells. The mechanosensing function of transformed OS cells was also impaired, with general downregulation of rigidity-sensing components. We identified toggling between normal and transformed growth based on the expression pattern of rigidity-sensing proteins in OS cells. We further uncovered a novel TP53 mutation (R156P) in transformed OS cells, which acquired gain of function to inhibit rigidity sensing, thus sustaining transformed growth. Our findings suggest a fundamental role of rigidity-sensing components in OS tumorigenicity as mechanotransduction elements through which cells can sense their physical microenvironment. In addition, the gain of function of mutant TP53 appears to serve as an executor for such malignant programs.
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The electrostatic pull-in effect is a common phenomenon and a key parameter in the design of microscale and nanoscale devices. Flexible electronic devices based on the pull-in effect have attracted increasing attention due to their unique ductility. This review summarizes nanoelectromechanical switches made by flexible materials and classifies and discusses their applications in, among others, radio frequency systems, microfluidic systems, and electrostatic discharge protection. It is supposed to give researchers a more comprehensive understanding of the pull-in phenomenon and the development of its applications. Also, the review is meant to provide a reference for engineers to design and optimize devices.
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Breastfeeding offers a broad spectrum of health benefits for infants. However, overnutrition and a steady increase in maternal obesity in the U.S. have made it harder for many mothers to produce and express breastmilk, and the quality of milk from obese mothers is also frequently compromised. Adipocytes, the primary cell type in the non-lactating breast, display a drastic morphological and functional change during lactation in mice. Lipid-filled adipocytes undergo lipolysis, and lipid droplets disappear to provide fatty acids and energy for breastmilk production. Once the animal stops lactation, these lipid-depleted adipocytes return as lipid-laden cells. This dynamic remodeling of the tissue is likely the result of active intercellular communications. Connexin43 (Cx43) is the most abundant connexin in the mammary adipose tissue that makes up the gap junctions for direct intercellular communications. Its expression is increased during lactation and reduced in obese mammary adipose tissue, which is resistant to lactation-induced remodeling. However, whether Cx43 is required for adipocyte remodeling and breastmilk production to support neonates' growth has not been established. In this study, we used doxycycline-inducible adipocyte-specific Cx43-deleted mice and demonstrated that adipocyte Cx43 played a vital role in determining the carbohydrate levels in breastmilk, which may subsequently affect neonates' growth.
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Adipose tissue is a promising target for treating obesity and metabolic diseases. However, pharmacological agents usually fail to effectively engage adipocytes due to their extraordinarily large size and insufficient vascularization, especially in obese subjects. We have previously shown that during cold exposure, connexin43 (Cx43) gap junctions are induced and activated to connect neighboring adipocytes to share limited sympathetic neuronal input amongst multiple cells. We reason the same mechanism may be leveraged to improve the efficacy of various pharmacological agents that target adipose tissue. Using an adipose tissue-specific Cx43 overexpression mouse model, we demonstrate effectiveness in connecting adipocytes to augment metabolic efficacy of the ß 3-adrenergic receptor agonist Mirabegron and FGF21. Additionally, combing those molecules with the Cx43 gap junction channel activator danegaptide shows a similar enhanced efficacy. In light of these findings, we propose a model in which connecting adipocytes via Cx43 gap junction channels primes adipose tissue to pharmacological agents designed to engage it. Thus, Cx43 gap junction activators hold great potential for combination with additional agents targeting adipose tissue.
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Plasma hyaluronan (HA) increases systemically in type 2 diabetes (T2D) and the HA synthesis inhibitor, 4-Methylumbelliferone, has been proposed to treat the disease. However, HA is also implicated in normal physiology. Therefore, we generated a Hyaluronan Synthase 2 transgenic mouse line, driven by a tet-response element promoter to understand the role of HA in systemic metabolism. To our surprise, adipocyte-specific overproduction of HA leads to smaller adipocytes and protects mice from high-fat-high-sucrose-diet-induced obesity and glucose intolerance. Adipocytes also have more free glycerol that can be released upon beta3 adrenergic stimulation. Improvements in glucose tolerance were not linked to increased plasma HA. Instead, an HA-driven systemic substrate redistribution and adipose tissue-liver crosstalk contributes to the systemic glucose improvements. In summary, we demonstrate an unexpected improvement in glucose metabolism as a consequence of HA overproduction in adipose tissue, which argues against the use of systemic HA synthesis inhibitors to treat obesity and T2D.
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Adipócitos/metabolismo , Tecido Adiposo/metabolismo , Dioxóis/farmacologia , Glucose/metabolismo , Ácido Hialurônico/metabolismo , Lipólise/efeitos dos fármacos , Adipócitos/citologia , Tecido Adiposo/citologia , Animais , Células Cultivadas , Diabetes Mellitus Tipo 2/metabolismo , Dieta Hiperlipídica/efeitos adversos , Feminino , Intolerância à Glucose/metabolismo , Homeostase , Humanos , Hipoglicemiantes/farmacologia , Masculino , Camundongos , Camundongos Transgênicos , Obesidade/etiologia , Obesidade/metabolismoRESUMO
Assessing lipid metabolism is a cornerstone of evaluating metabolic function, and it is considered essential for in vivo metabolism studies. Lipids are a class of many different molecules with many pathways involved in their synthesis and metabolism. A starting point for evaluating lipid hemostasis for nutrition and obesity research is needed. This paper describes three easy and accessible methods that require little expertise or practice to master, and that can be adapted by most labs to screen for lipid-metabolism abnormalities in mice. These methods are (1) measuring several fasting serum lipid molecules using commercial kits (2) assaying for dietary lipid-handling capability through an oral intralipid tolerance test, and (3) evaluating the response to a pharmaceutical compound, CL 316,243, in mice. Together, these methods will provide a high-level overview of lipid handling capability in mice.
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Metabolismo dos Lipídeos , Agonistas de Receptores Adrenérgicos beta 3/farmacologia , Animais , Bioensaio , Dieta Hiperlipídica , Dioxóis/farmacologia , Emulsões/farmacologia , Jejum , Metabolismo dos Lipídeos/efeitos dos fármacos , Lipólise/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Fosfolipídeos/farmacologia , Óleo de Soja/farmacologia , Triglicerídeos/sangueRESUMO
Volatile compounds in 'Sweetheart' lychee were examined using gas chromatography-olfactometry/mass spectrometry (GC-O/MS). Solvent assisted flavor evaporation (SAFE) technique was used to identify the aroma-active compounds in lychee. Further characterization of the most important odorants in 'Sweetheart' lychee was achieved using aroma extract dilution analysis (AEDA). Thirty-one key aroma-active odorants were identified in the flavor dilution (FD) factor range of 2-1024. Methional (cooked potato) and geraniol (sweet, floral) exhibited the highest FD factors of 1024 and 512, respectively, these were followed by furaneol (sweet, caramel), nerol (floral, sweet), dimethyl trisulfide (DMTS) (preserved vegetable, sulfury), linalool (floral), (E,Z)-2,6 nonadienal (cucumber) and nerolidol (metalic, sesame oil). Furthermore, the flavor profile of 'Sweetheart' lychee was described by sensory analysis. Floral, tropical fruit, peach/apricot and honey were scored with relatively high scores for each aroma attribute. The sweetness rating was the highest score among all the attributes.
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Aromatizantes/química , Litchi/química , Adulto , Feminino , Frutas/química , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Masculino , Pessoa de Meia-Idade , Odorantes/análise , Olfatometria , Paladar , Compostos Orgânicos Voláteis/química , Adulto JovemRESUMO
The fabrication of tiron-copper complex as a novel fluorescence probe for the sensitive directly detection of metallothioneins at nanomolar levels was demonstrated. In Britton-Robinson (B-R) buffer (pH 7.50), the interaction of bis(tiron)copper(II) complex cation [Cu(tiron)2](2+) and metallothioneins enhanced the fluorescence intensity of the system. The fluorescence enhancement at 347 nm was proportional to the concentration of metallothioneins. The mechanism was studied and discussed in terms of the fluorescence spectra. Under the optimal experimental conditions, at 347 nm, there was a linear relationship between the fluorescence intensity and the concentration of the metallothioneins in the range of 8.80 × 10(-9)-7.70 × 10(-7)mol L(-1), with a correlation coefficient of r=0.995 and detection limit 2.60 × 10(-9)mol L(-1). The relative standard deviation was 0.77% (n=11), and the average recovery 94.4%. The method proposed was successfully reliable, selective and sensitive in determining of trace metallothioneins in fish visceral organ samples with the results in good agreement with those obtained by HPLC.