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A one-pot synthesis of 2,4-disubstituted quinazoline derivatives from halofluorobenzenes with nitriles was reported, via sequential nucleophilic addition and SNAr reaction. The advantages of the present approach are transition metal free, easy to operate, and all the starting materials are commercially available.
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The use of transition-metal nanoparticles/ionic liquid (IL) as a thermoregulated and recyclable catalytic system for hydrogenation has been investigated under mild conditions. The functionalized ionic liquid was composed of poly(ethylene glycol)-functionalized alkylimidazolium as the cation and tris(meta-sulfonatophenyl)phosphine ([P(C(6)H(4)-m-SO(3))(3)](3-)) as the anion. Ethyl acetate was chosen as the thermomorphic solvent to avoid the use of toxic organic solvents. Due to a cooperative effect regulated by both the cation and anion of the ionic liquid, the nanocatalysts displayed distinguished temperature-dependent phase behavior and excellent catalytic activity and selectivity, coupled with high stability. In the hydrogenation of α,ß-unsaturated aldehydes, the ionic-liquid-stabilized palladium and rhodium nanoparticles exhibited higher selectivity for the hydrogenation of the C=C bonds than commercially available catalysts (Pd/C and Rh/C). We believe that the anion of the ionic liquid, [P(C(6)H(4)-m-SO(3))(3)](3-), plays a role in changing the surrounding electronic characteristics of the nanoparticles through its coordination capacity, whereas the poly(ethylene glycol)-functionalized alkylimidazolium cation is responsible for the thermomorphic properties of the nanocatalyst in ethyl acetate. The present catalytic systems can be employed for the hydrogenation of a wide range of substrates bearing different functional groups. The catalysts could be easily separated from the products by thermoregulated phase separation and efficiently recycled ten times without significant changes in their catalytic activity.
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Two-dimensional hexagonal boron nitride (hBN) atomic crystals are excellent charge scattering screening interlayers for advanced electronic devices. Although wafer-scale single crystalline hBN monolayer films have been demonstrated on liquid Au and solid Cu (110) and (111) vicinal surfaces, their reproducible growth still remains challenging. Here, we report the facile self-aligned stitching growth of centimeter-scale quasi-single-crystalline hBN monolayer films through synergistic chemical vapor deposition growth kinetics and liquid Cu rheological kinetics control. The sublimation temperature of the ammonia borane precursor, H2 content and melting temperature of the Cu substrate are revealed to be the dominant factors that regulate hBN nucleation, growth and alignment. The flowing liquid Cu catalytic surface promotes efficient rotation of floating triangular hBN domains and provokes uniform self-alignment upon merging at a critical high temperature of 1105 °C. Identical aligned grains are constantly observed at multiple regions, which corroborate the homogeneous in-plane orientation and uniform stitching over the whole growth area. Continuous quasi-single-crystalline hBN monolayer films are produced by seamless stitching of aligned domains with the same polarity. The quasi-single-crystalline hBN monolayers are successfully included as charge scattering and trap site screening interlayers in the hBN/SiO2 gate insulator stack to build high performance InGaZnO field-effect transistors (FETs). Full suppression of hysteresis and twofold enhancement of field-effect mobility are realized for InGaZnO FETs built with hBN as the interface dielectric. The facile growth of large quasi-single-crystalline hBN monolayers on liquid Cu paves the way for future high-performance electronics.
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BACKGROUND: The discovery of heat-sensitive Transient Receptor Potential Vanilloid (TRPV) ion channels provided a potential molecular explanation for the perception of innocuous and noxious heat stimuli. TRPV1 has a significant role in acute heat nociception and inflammatory heat hyperalgesia. Yet, substantial innocuous and noxious heat sensitivity remains in TRPV1 knockout animals. Here we investigated the role of two related channels, TRPV3 and TRPV4, in these capacities. We studied TRPV3 knockout animals on both C57BL6 and 129S6 backgrounds, as well as animals deficient in both TRPV3 and TRPV4 on a C57BL6 background. Additionally, we assessed the contributions of TRPV3 and TRPV4 to acute heat nociception and inflammatory heat hyperalgesia during inhibition of TRPV1. RESULTS: TRPV3 knockout mice on the C57BL6 background exhibited no obvious alterations in thermal preference behavior. On the 129S6 background, absence of TRPV3 resulted in a more restrictive range of occupancy centered around cooler floor temperatures. TRPV3 knockout mice showed no deficits in acute heat nociception on either background. Mice deficient in both TRPV3 and TRPV4 on a C57BL6 background showed thermal preference behavior similar to wild-type controls on the thermal gradient, and little or no change in acute heat nociception or inflammatory heat hyperalgesia. Masking of TRPV1 by the TRPV1 antagonist JNJ-17203212 did not reveal differences between C57BL6 animals deficient in TRPV3 and TRPV4, compared to their wild-type counterparts. CONCLUSIONS: Our results support the notion that TRPV3 and TRPV4 likely make limited and strain-dependent contributions to innocuous warm temperature perception or noxious heat sensation, even when TRPV1 is masked. These findings imply the existence of other significant mechanisms for heat perception.
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Temperatura Alta , Canais de Cátion TRPV/metabolismo , Sensação Térmica/fisiologia , Animais , Comportamento Animal , Inflamação/metabolismo , Inflamação/patologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nociceptores/metabolismo , Canais de Cátion TRPV/antagonistas & inibidoresRESUMO
The highly water-soluble palladium nanoparticles (NPs) were synthesized by using the amphiphilic poly(ethylene glycol)-functionalized dicationic imidazolium-based ionic liquid (C(12)Im-PEG IL) as a stabilizing agent. The aqueous dispersed palladium NPs in the range of 1.9 ± 0.3 nm were observed by transmission electron microscopy (TEM). The physicochemical properties of C(12)Im-PEG IL in aqueous phase have been characterized by electrical conductivity, surface tension and dynamic light scattering (DLS) measurements. It was demonstrated that the amphiphilic ionic liquid can form micelles above its critical micelle concentration (CMC) in aqueous solution and the micelles played a crucial role in stabilizing the palladium NPs and thus promoted catalytic hydrogenation. Furthermore, the dicationic ionic liquid can also act as a gemini surfactant and generated emulsion between hydrophobic substrates and the catalytic aqueous phase during the reaction. The aqueous dispersed palladium NPs showed efficient activity for the catalytic hydrogenation of various substrates under very mild conditions and the stabilizing Pd(0) nanoparticles (NPs) can be reused at least eight times with complete conservation of activity.
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A rapid and simple method to detect tumor markers in liver cancer was established by combining immunochromatography technique with fluorescent microsphere labeling. According to the principle of double antibody sandwich, the cytoskeleton-associated protein 4 (CKAP4) paired antibody was used as the labeled and coated antibody, and the goat anti-rabbit polyclonal antibody was used as the quality control line coated antibody in the preparation of the CKAP4 fluorescent immunochromatographic test strips. After the preparation, the test strips were evaluated on various performance indicators, such as linearity, precision and stability. The CKAP4 immunochromatographic strip prepared by time-resolved fluorescent microspheres had high sensitivity, and good specificity. Its precision was within 15%, recovery between 85% and 115%, and linear range between 25 and 1 000 pg/mL. The test strip could be kept stable at 37 °C for 20 days, and it correlated well with commercial ELISA kits. The CKAP4 fluorescence immunochromatography method can quantitatively detect the content of CKAP4 in serum. Furthermore, it is rapid, sensitive, simple, economical and single-person operation. This method has the potential of becoming a new method for the diagnosis and treatment of liver cancer.
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Cromatografia de Afinidade , Neoplasias Hepáticas , Proteínas de Membrana , Técnicas de Diagnóstico Molecular , Animais , Anticorpos/metabolismo , Fluorescência , Humanos , Neoplasias Hepáticas/diagnóstico , Proteínas de Membrana/isolamento & purificação , Técnicas de Diagnóstico Molecular/instrumentação , Técnicas de Diagnóstico Molecular/métodos , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: In recent years, nanotechnology has attracted a plethora of attention due of its ability to effectively diagnose and treat various tumors. Virus-like particles (VLPs) have good biocompatibility, are safe and non-toxic, and have an internal hollow space, and as such they are often used as nano drug carriers. In recent years, it has become one of the hot spots in the field of biopharmaceutical engineering. METHODS: In this study, the tumor-targeting peptide RGD (Arg-Gly-Asp) was genetically inserted into the major immunodominant region (MIR) of the hepatitis B virus core protein (HBc). A series of characterization, including stability and optical properties, were evaluated. A visual diagnosis and analysis of the efficacy against tumor cells were conducted at the cell level and using a live animal model. RESULTS: This study demonstrated that the recombinant HBc-based VLPs could participate in self-assembly of monodispersed nanoparticles with well-defined morphology, and the near-infrared dye indocyanine green (ICG) could be packaged into the VLPs without any chemical modification. Moreover, the HBc-based VLPs could specifically target cancer cells via the interaction with overexpressed integrin αvß3. The treatment with ICG-loaded HBc-based VLPs showed significant inhibition of 4T1 breast cancer cell growth (84.87% tumor growth inhibition). The in vivo imaging experiments demonstrated that the ICG-loaded HBc-based VLPs generated excellent fluorescence in tumor sites in 4T1 breast cancer bearing mice. This provided crucial information on tumor mass location, boundaries, and shape. Moreover, compared to free ICG, the nanosystem showed significantly longer blood circulation time and superior accuracy in targeting the tumor. CONCLUSIONS: The ICG-loaded HBc-based VLPs prepared in this study were of good stability and biocompatibility. It showed strong tumor targeting specificity and tumor visualization. Thus, it is expected to provide a new experimental basis and theoretical support for the integration of VLPs in the clinical diagnosis and treatment of breast cancer.
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InGaZnO (IGZO) is currently the most prominent oxide semiconductor complement to low-temperature polysilicon for thin-film transistor (TFT) applications in flat panel displays. However, the compromised transport performance and bias stress instability are critical issues inhibiting its application in ultrahigh-resolution optoelectronic displays. Here, we report the fabrication of graded channel junctionless IGZO:O|N TFTs with both high transporting properties and good bias stress stability by systematic manipulation of oxygen vacancy (VO) defects through sequential O antidoping and O/N codoping of the continuous IGZO framework. The transporting properties and bias stress stability of the graded channel IGZO:O|N TFTs, which exhibited high field-effect mobilities close to 100 cm2 V-1 s-1, negligible performance degradations, and trivial threshold voltage shifts against gate bias stress and photobias stress, are simultaneously improved compared to those of the controlled single-channel uniformly doped IGZO:O TFTs, IGZO:N TFTs, and double-channel barrier-confined IGZO:O/IGZO:N TFTs. The synergistic improvements are attributed to the sequential mobility and stability enhancement effects of O antidoping and O/N codoping where triple saturation currents are induced by O antidoping of the front-channel regime while the trapped electrons and photoexcited holes in the back-channel bulk and surface regions are suppressed by O/N codoping. More importantly, fast accumulation and barrier-free full depletion are rationally realized by eliminating the junction interface within the graded channel layer. Our observation identifies that graded channel doping could be a powerful way to synergistically boost up the transport performance and bias stress stability of oxide TFTs for new-generation ultrahigh-definition display applications.
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Ionic liquid (1-butyl-2,3-dimethylimidazolium acetate, [BMMIm]OAc)-Pluronic P123 mixed micelle stabilized water-soluble Ni nanoparticles were characterized by UV-vis, XRD, XPS and TEM and then employed for catalytic hydrogenation. It was demonstrated that the mixed-micelle stabilized Ni NPs showed excellent catalytic performance for the selective hydrogenation of CC and nitro compounds in the aqueous phase under very mild reaction conditions, and also the Ni NPs catalysts can be recycled at least for eight times without significant decrease in catalytic activity. The results of characterization revealed that the mixed micelle-stabilized Ni NPs catalysts were highly dispersed in aqueous phases even after five catalytic recycles. In addition, adding ionic liquid ([BMMIm]OAc) can affect the micelle structure of P123 solutions and thus afford an additional steric protection from aggregation of Ni NPs, resulting in enhancing stability and catalytic activity of Ni NPs.
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Imidazóis/química , Líquidos Iônicos/química , Nanopartículas Metálicas/química , Níquel/química , Poloxaleno/química , Alcenos/química , Catálise , Reutilização de Equipamento , Hidrogenação , Nanopartículas Metálicas/ultraestrutura , Micelas , Microscopia Eletrônica de Transmissão , Nitrocompostos/química , Espectroscopia Fotoeletrônica , Água/químicaRESUMO
Nickel nanoparticles (NPs) well-dispersed in the aqueous phase were conveniently prepared by reducing nickel(II) salt with hydrazine in the presence of the functionalized ionic liquid 1-(3-aminopropyl)-2,3-dimethylimidazolium bromide. UV/Vis spectroscopy, elemental analysis, thermogravimetric analysis (TGA), and X-ray photoelectron spectroscopy (XPS) show the presence of a weak interaction of the functionalized ionic liquid with Ni(II) and Ni(0) complexes. The face-centered cubic structure of the Ni(0) NPs was confirmed by X-ray diffraction (XRD) characterization. Transmission electron microscopy (TEM) images reveal that smaller Ni(0) particles of approximately 6-7 nm average diameter assemble to give larger, blackberry-shaped particles with an average diameter of around 35 nm. The Ni NPs were employed as highly efficient catalysts for the selective hydrogenation of C=C double bonds in the aqueous phase under mild reaction conditions (40-90 degrees C at 1.0-3.0 MPa), and the Ni(0) nanocatalysts in the aqueous phase are stable enough to be reused at least seven times without significant loss of catalytic activity during subsequent reuse cycles.