Abstract Thermal protection materials with high optical reflectivity, low thermal conductivity, and good high‐temperature stability are required for the development of laser technologies and the protection of the critical equipment components. Herein, we synthesize a novel thermal protective material, La 0.9 Sr 0.1 Ti 1− x Nb x O 3+ δ (LSTN; x = 0.1, 0.125, 0.15), with different Nb 5+ ‐ion contents using solid‐state sintering. Phase structure analysis demonstrates that LSTN ( x = 0.1, 0.125, 0.15) presents a single‐phase monoclinic structure with a uniform element distribution. In particular, the LSTN 0.125 ceramic exhibits ultrahigh optical reflectivity (96%, 2300 nm) and excellent thermophysical properties, such as a high thermal expansion coefficient (10.3 × 10 −6 K −1 , 1000°C), an ultralow thermal conductivity (0.408 W (m K) −1 , 300°C), and excellent high‐temperature stability. Aberration‐corrected scanning transmission electron microscopy reveals that the disordered substitution of Nb 5+ ions induces numerous lattice distortions and mass fluctuations, which decrease the thermal conductivity, and makes difference in the relative refractive indices of atomic layers causing the high reflectivity of the material. These remarkable properties render the LSTN 0.125 ceramic as an ideal alternative for near‐infrared thermal protection applications.
ABSTRACT Mume Fructus (MF), a representative substance in the field of medicine‐food homology, has been extensively utilized in clinical treatments and daily diets for its raw and processed forms. This study aimed to establish the spectrum‐effect relationship between ultra–high‐performance liquid chromatography coupled with quadrupole tandem time‐of‐flight mass spectrometry (UHPLC‐Q‐TOF‐MS/MS) fingerprints and anti‐inflammatory and antitussive activities of raw and processed MF extracts. In UHPLC‐Q‐TOF‐MS/MS fingerprints, a total of 21 common peaks were identified. Bioactivity assays demonstrated that the raw and processed MF extracts exhibited varying degrees of anti‐inflammatory and antitussive effects. Subsequently, the relevant pharmacologically active ingredients were screened by grey relation analysis and partial least squares regression. The results showed that nine components were associated with anti‐inflammatory effects, namely, citric acid, isochlorogenic acid B, isochlorogenic acid A, isochlorogenic acid C, fumaric acid, gallic acid, neochlorogenic acid, chlorogenic acid, and ononin. Additionally, three components were linked to antitussive activity: amygdalin, syringic acid, and succinic acid, respectively. This work developed a model combining UHPLC‐Q‐TOF‐MS/MS fingerprints with anti‐inflammatory and antitussive activities to study the spectrum‐effect relationship of raw and processed MF extracts. The findings provide a reference for the discovery of bioactive components and contribute to the clinical rationalization of medications.
Hollow mesoporous silica nanoparticles (HMSN) have been widely studied as drug delivery carriers due to their high drug loading capacity in the internal cavity. In this study, monodisperse and temperature-responsive hollow mesoporous silica nanoparticles (HMSN@P(NIPAM-co-NHMA)) were synthesized and investigated. HMSN and HMSN@P(NIPAM-co-NHMA) were characterized by SEM, TEM, FT-IR, TGA, XRD and nitrogen adsorption-desorption isotherms. The results showed that the cross-linked temperature-sensitive polymer P(NIPAM-co-NHMA) was grafted onto the surface of HMSN. Subsequently, using PUE as the drug model, the results demonstrated that the HMSN@P(NIPAM-co-NHMA) had an excellent loading efficiency and exhibited excellently temperature-sensitive release behavior. Furthermore, the biocompatibility and stability of HMSN and HMSN@P(NIPAM-co-NHMA) were studied by MTT assay and hemolysis assay, the results indicated HMSN@P(NIPAM-co-NHMA) possessed excellent biocompatibility and stability. Thus, we have successfully synthesized HMSN@P(NIPAM-co-NHMA), and the drug release is temperature-responsive, which can realize controlled drug release.
Purpose Although word of mouth (WOM) affects customers’ purchasing intentions to a large extent, prior research has neglected the role of WOM as a driver of customer satisfaction. Design/methodology/approach Several scholars have suggested that WOM can not only affect customer expectation but also can influence perceived quality. Consistent with existing research results and the expectancy disparity model, this paper established a causal relation between WOM and customer satisfaction and confirmed it was drawing on an experimental study. Findings This paper indicates that positive or negative WOM affects customer satisfaction by promoting or lowering customers’ expectations. This relation is moderated by product type, rather than the source of the WOM. With experience goods, positive (negative) WOM will decrease (increase) customer satisfaction. However, with search goods, positive (negative) WOM will increase (decrease) customer satisfaction. Originality/value The results of this study have implications for academia and management. Academically, this study establishes the causal relation between WOM and customer satisfaction, expanding the research on the relation between WOM and satisfaction. From a managerial perspective, the promotion of WOM also can create certain service risks.
Mesoporous silica nanoparticles (MSNs) are one of the most promising carriers for drug delivery. MSNs have been widely used in pharmaceutical research as drug carriers because of their large pore volume, high surface area, excellent biocompatibility, nontoxicity, ease to functionalize, and sustained release effects. MSNs have attracted much attention during drug delivery because of their special structure.The present study aimed to synthesize mesoporous silica nanoparticles (MSNs), dendritic mesoporous silica nanoparticles (DMSN), and hollow mesoporous silica nanoparticles (HMSN) through facile methods, and to compare the drug release properties of nano-porous silica with different pore structures as a stroma for PUE drug.MSN, DMSN, and HMSN were characterized by SEM, TEM, FT-IR, nitrogen adsorptiondesorption isotherms, XRD, and zeta potential methods. Subsequently, puerarin (PUE) was used as the active ingredient and loaded into the three mesoporous materials, respectively. And, the drug delivery behavior was measured in PBS solution with different pH values. The sustained-release properties of MSN, DMSN, and HMSN loaded with PUE were investigated. Finally, the biocompatibility and stability of MSN, DMSN, and HMSN were studied by MTT assay and hemolysis assay.Our results showed that MSN, DMSN, and HMSN were successfully synthesized and the three types of mesoporous silica nanoparticles had higher drug loading and encapsulation efficiency. According to the first-order release equation curve and Higuchi equation parameters, the results showed that the PUE-loaded MSN, DMSN, and HMSN exhibited sustained-release properties. Finally, MTT and hemolysis methods displayed that MSN, DMSN, and HMSN had good biocompatibility and stability.In this study, MSN, DMSN, and HMSN were successfully synthesized, and to compare the drug release properties of nano-porous silica with different pore structures as a stroma for PUE drug, we provided a theoretical and practical basis for the application of PUE.
The plasmon-mediated coupling reaction of nitroaromatic compounds is an effective strategy to synthesize the aromatic azo compounds that are widely applied in material science, pharmacy, and agricultural chemistry. Nonetheless, the reaction rate can be further improved since the lifetime of the plasmon-generated hot carriers is limited to femtoseconds or picoseconds. Herein, using in situ plasmon-enhanced Raman spectroscopy, we reveal that the adsorbed positively charged methyl violet molecules on the silver nanoparticle (Ag NP)–graphene oxide (GO) composite structure act as simple and cost-effective molecular cocatalysts, largely boosting the coupling of p-nitrothiophenol to p,p′-dimercaptoazobenzene. This boosting is attributed to the promoted separation of the plasmon-generated hot carriers at the Ag NP–GO interface. In addition, the reduction of laser power will help to promote the efficiency of the MV-induced acceleration. This work provides a highly simple, efficient, and cost-effective strategy to accelerate the coupling reaction of nitroaromatic compounds, and this strategy can be extended to the acceleration of many other plasmon-mediated chemical reactions.
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