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Five C-glycosylflavone were isolated from Vaccaria hispanica (Miller) Rauschert seeds. Their NMR spectra showed separate signals because of the existence of rotational isomers, which is an unusual phenomenon. The spectroscopic data revealed that compounds 1 – 5 were identified as apigenin 6- C -[ α - l -arabinopyranosyl-(1′′′→2′′)- β - d -glucopyranosyl]-7- O - β - d -glucopyranoside ( 1 ), apigenin 6- C -[ α - l -arabinopyranosyl-(1′′′→2′′)- β - d -glucopyranosyl]-7- O -(6′′′′- O -dihydroferuloyl)- β - d -glucopyranoside ( 2 ), apigenin 6- C - β - d -glucopyranosyl-7- O -(6′′′- O -dihydroferuloyl)- β - d -glucopyranoside ( 3 ) and isovitexin-2′′- O -arabinoside ( 4 ) and saponarin ( 5 ), respectively. The structure of ‘vaccarin’ was revised to apigenin 6- C -[ α - l -arabinopyranosyl-(1′′′→2′′)- β - d -glucopyranosyl]-7- O - β - d -glucopyranoside and consequently 1 should be named ‘vaccarin’. Among the isolated compounds, 2 and 3 are new and named vaccarin E and vaccarin F, respectively. [ABSTRACT FROM AUTHOR]

Four new glycosides, including one anthraquinone glycoside ( 1 ), one naphthalene glycoside ( 2 ), and two naphthopyrone glycosides ( 3 – 4 ), with 10 known compounds ( 5 – 14 ) were isolated from the seeds of Cassia obtusifolia L. The new structures were determined by spectroscopic analysis and chemical transformations. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance The processed lateral root of Aconitum carmichaelii Debeaux (Ranunculaceae), an extensively used traditional Chinese medicine, is known as Fuzi in China (Chinese: 附子), “bushi” in Japan, “Kyeong-Po Buja” in Korea, Chinese aconite, monkshood or Chinese wolfsbane. It has been used to treat shock resulting from acute myocardial infarction, low blood pressure, coronary heart disease, chronic heart failure, etc. Aim of the review The present paper aims to provide an up-to-date review at the advancements of the investigations on the ethnopharmacology, phytochemistry, pharmacological effect and toxicity of Fuzi. Besides, the possible tendency and perspective for future research of this plant are discussed, as well. Materials and methods All available information on Fuzi was collected via electronic search (using Elsevier, PubMed, ACS, CNKI, Google Scholar, Baidu Scholar, and Web of Science), books and classic works about Chinese herb. Results 122 chemical constituents, among which C 19 -diterpenoid alkaloids and C 20 -diterpenoid alkaloids are the predominant groups, have been isolated and identified from Fuzi. Fuzi with its active compounds is possessed of wide-reaching biological activities, including effects on cardiovascular system, anti-inflammation and analgesic action, anti-tumor activity, effect on the immune system, hypoglycemic and hypolipidemic effects, anti-aging effect, effect of protecting kidney and effect on energy metabolism. Conclusions Nearly all of compounds were found from the roots of the plant, so further phytochemical studies should focus more on the other parts of the plant, such as the leaves, flowers or stems. Besides, a majority of the pharmacological studies were carried out using crude and poorly characterized extracts. Thus, more bioactive components particularly cardiotonic and analgesic compounds should be identified through bioactivity-guided isolation strategies. Moreover, investigations on how to develop Fuzi׳s new clinical usage on the basis of its pharmacological effects are in requirement. [ABSTRACT FROM AUTHOR]

The phase composition, microstructure, electrical and thermal properties of hot-pressed AlN-2 wt% Yb 2 O 3 -4 wt% Sm 2 O 3 - x wt% TiN (x = 0, 0.4, 0.8, 1, 2, 3, 4) ceramics were systematically investigated. Yb 2 O 3 and Sm 2 O 3 were used to react with Al 2 O 3 in AlN to form Yb 3 Al 5 O 12 , SmAlO 3 and SmAl 11 O 18 , which made the samples densely sintered. When sintered at higher than 1700 °C, the electrical resistivity of AlN ceramics with 2 wt% Yb 2 O 3 -4 wt% Sm 2 O 3 decreased significantly to 1010 Ω·cm. This decrease in resistivity was probably caused by the continuity of the secondary phase, which encasing the AlN grains and deteriorating the thermal conductivity. When sintered at 1650 °C, the addition of 0.4–4.0 wt% TiN reduces the electrical resistivity from 8.9 × 1012 to 2 × 1010 Ω·cm while maintaining thermal conductivity at around 90 W/m·K with high compactness. Finally, a series of high performance AlN ceramics, with adjustable electrical/thermal properties, could be obtained for modern semiconductor industry. [ABSTRACT FROM AUTHOR]

Alumina ceramics with optimized microstructures and mechanical properties were obtained by the attractive digital lighting processing (DLP) additive manufacturing methodology in the present study. A acrylate-based resin system was designed for the alumina powders with a mean particle size of 0.5 μm. The influence of oligomer on the viscosity and polymerization kinetics of the ceramic suspensions has been elaborately discussed by rheology, curing depth and photo-DSC characterizations. The results indicated that the introduction of oligomer has improved the cross-linking density of resins and decreased the critical dose of energy for resin polymerization, which contributed to a tougher ceramic-resin slice with higher dimensional accuracy. Densifying processes including debinding and high temperature sintering of the ceramic parts were conducted according to the TG-DTA characterizations, alumina ceramics with uniform microstructures and eliminated delamination or intralaminar cracks were finally obtained. The flexural strength was 471 MPa for the ceramics obtained from the resin composition containing 20 wt% oligomer, Weibull modulus for the ceramics were determined to be 17.31 by evaluating thirty all sides polished ceramics, indicating the highly uniform property of the ceramics fabricated by DLP additive manufacturing. [ABSTRACT FROM AUTHOR]

Highlights: [•] The up-conversion emission intensity of NaYF4:Yb3+, Er3+ after silica coating was significantly enhanced. [•] The up-conversion intensity ratio between red emission and green emission was decreased after silica coating. [•] The mechanism of up-conversion luminescence and emission intensity change was illuminated. [ABSTRACT FROM AUTHOR]

Highlights: [•] Combustion method and vacuum sintering were used to fabricate La2-xGdxZr2O7. [•] The lattice parameters decreased with the increase of Gd3+ concent(x). [•] The absorption edge of the transmittance curves shifted to UV region from 0.4-2.0. [•] All the ceramics have high n (2.08), making them candidate for optical lens. [•] With the increase of x, the effective atomic number and density increased. [Copyright &y& Elsevier]

Two-dimensional carbon fiber reinforced zirconia matrix composites have been fabricated by slurry infiltration and hot pressing techniques. The room temperature mechanical properties were investigated and the fracture features of composites were observed. The results showed that with the increase of temperature the relative density of as-prepared Cf/ZrO2 composites increased. But the mechanical properties of composites on fiber configuration firstly increased and then decreased. Higher mechanical properties were obtained for the composite hot-pressed at 1500°C i.e. the flexural force and fracture energy were 136.0N and 31.3kJ·m−2 respectively. SEM observation revealed fiber pull-out in the composite sintered at ≤1500°C. For the composite sintered at a higher temperature, however, chemical diffusion between fiber and ZrO2 was found by HRTEM, which indicates the formation of strong bonding. Also the reduced nonlinear region and short pullout length of fiber suggest a strong interfacial bonding between the fiber and matrix. The strong interfacial bonding and large thermal residual stress mainly contribute to the degradation of mechanical properties above 1500°C. [ABSTRACT FROM AUTHOR]

Abstract: NaYF4 co-doped with Gd3+ and Mn2+ nanocrystals were synthesized by a solvothermal route with PEI as the surfactant. X-ray diffraction analyses evidenced that the phases of synthesized NaYF4: Gd3+, Mn2+ nanocrystals were all pure cubic structure. The luminescence intensity of 20mol% Gd3+ doped NaYF4 was stronger than that of any other concentration under the 272nm excitation. The photoluminescence emission intensity of NaYF4: Gd3+, Mn2+ at 561nm was increased with the increase of Gd3+ doping concentration. The energy transfer mechanisms between Gd3+ and Mn2+ were discussed. The results showed that the energy level of 6PJ of Gd3+ ions played a key role in the energy transfer process. Furthermore, the Mn2+ ions doped NaYF4: Gd3+ nanocrystals with a strong green emission and proper paramagnetism originated from Gd3+ and Mn2+ may find potential applications in bio-probes and magnetic resonance imaging. [Copyright &y& Elsevier]

Abstract: A simple combustion method was used to synthesize LaGdZr2O7 powder and LaGdZr2O7 transparent ceramic was prepared by vacuum sintering at 1850°C for 6h. The final transparent ceramic, with a density of 6.46g/cm3, has an in-line transmittance of 70.7% at 1000nm and a refractive index of 2.08 at 632.8nm. [Copyright &y& Elsevier]

Abstract: Y2Hf2O7 transparent ceramics were successfully fabricated via vacuum sintering at 1900°C for 6–12h by the solid-state reaction using the corresponding nitrate and oxide powders without additives. The fabricated transparent ceramics showed a well-defined microstructure and no pores or other defects were observed. The linear optical transmittance reached to 60% in the visible wavelength region, which is about 76% of the corresponding single crystal. The refractive index of the Y2Hf2O7 transparent ceramics was above 2.01 in the region between 400nm and 800nm. [Copyright &y& Elsevier]

Abstract: High quality transparent yttrium aluminum garnet (YAG) ceramics with an average grain size of about 12μm have been fabricated by a solid state reactive sintering method. Plasma resistance property of the fabricated YAG ceramics was studied and compared with that of the Y2O3 ceramics, silicate glass and quartz. The YAG ceramics showed an excellent plasma resistance as well as Y2O3 ceramics. After etching in F-plasma for 6h, the eroded depth of YAG ceramics was about 100nm. The plasma resistance of YAG ceramics was far better than that of silicate glass and quartz. [Copyright &y& Elsevier]

Abstract: Commercial Y2O3 powder was used to fabricate highly transparent Y2O3 ceramics with the addition of ZrO2 via slip casting and vacuum sintering. The effects of ZrO2 addition on the transparency, grain size and lattice parameter of Y2O3 ceramics were studied. With addition of ZrO2 the transparency of Y2O3 ceramics increased markedly and the grain size of Y2O3 ceramics decreased markedly by cation diffusivity mechanism and the lattice parameter of Y2O3 ceramics slightly decreased. The highest transmittance (at wavelength 1100nm) of the 5.0mol% ZrO2–Y2O3 ceramic (1.0mm thick) sintered at 1860°C for 8h reached 81.7%, very close to the theoretical value of Y2O3. [Copyright &y& Elsevier]

Low-cost amorphous nano-carbon (ANC) was employed as an absorbent to modify the microwave performance of AlN ceramics (AlN-4 wt% Y 2 O 3 - x wt% C, x = 0, 2.0, 3.8, 3.9, 4.0) via hot-pressing sintering, and the thermal and mechanical properties were also investigated. With the increase of ANC content from 0 to 4.0 wt%, the relative density of AlN composite decreases from 3.28 g cm−3 to 3.16 g cm−3 when sintered at 1800 °C for 2 h, and with the increase of sintering temperature from 1700 °C, the density of the 4.0 wt% ANC doped AlN composite presents trend of increase and reaches the maximum value of 3.16 g cm−3 at 1800 °C and then decreases. The XRD pattern shows that the composites are composed of AlN and Y–Al–O (YAG, YAP, YAM et al.) phases. SEM results indicate that average grain sizes for AlN and secondary phases gradually decrease with increasing carbon content, suggesting inhibited grain growth due to ANC addition. No obvious changes in phase constitution nor intensity changes were detected with the increase in carbon content and sintering temperature. As the carbon content increases from 0 to 4.0 wt%, the dielectric constant gradually increases from ∼9 to 13.89 at 10 GHz, the dielectric loss gradually increases from the vicinity of 10−3 to 0.38 at 10 GHz, and the reflective loss decreases from −27.92 dB to −49.40 dB, the thermal conductivity of the AlN-ANC composite decreases from 116.63 W m−1 K−1 to 50.13 W m−1 K−1. In addition, with 4.0 wt% ANC addition, the dielectric constant, dielectric loss, reflective loss, hardness, elastic modulus, bending strength, and fracture toughness are 13.89, 0.38, 49.40 dB, 6.4 ± 0.4 GPa, 262 GPa, 268.78 MPa, and 1.4 ± 0.1 MPa m1/2, respectively. Its ability to efficiently absorb microwave energy enhances the performance of devices including radar systems, communication equipment, and microwave heating systems, making it a promising candidate for microwave vacuum electronic applications. [ABSTRACT FROM AUTHOR]

Four control experiments (S1: Y 3 Al 5 O 12 , S2: Y 3 Al 5 O 12 +1 wt%Nb 2 O 5 , S3: Y 3 Al 4.955 Nb 0.045 O 12 , S4: Y 2.955 Al 5 Nb 0.045 O 12) were designed to investigate the co-effects of Nb 2 O 5 and non-stoichiometry on the microwave dielectric properties of Y 3 Al 5 O 12. The beneficial results of Nb 2 O 5 doping are demonstrated based on X-ray patterns, electron diffraction information, Rietveld refinement, and micromorphological characterization. Differences in dielectric properties were explored using lattice defects, ion polarizability, bond valence, and Raman spectroscopy. In contrast, the Y-deficient sample (S4) possesses the best dielectric properties (ε r ∼ 10.37, Q × f ∼ 161,724 GHz and τ f ∼ -33.8 ppm/°C). [ABSTRACT FROM AUTHOR]

Highly transparent yttrium titanate (Y 2 Ti 2 O 7) ceramics were fabricated by vacuum sintering using co-precipitated powders for the first time. The effects of the powder calcination temperature on the phase composition, morphology of the calcined powders, and on the microstructure and transmittance of the Y 2 Ti 2 O 7 ceramics were investigated. When the calcination temperature was above 850 °C, pure phase Y 2 Ti 2 O 7 nanopowders with high sintering activity were obtained. Transparent Y 2 Ti 2 O 7 ceramics were obtained after vacuum sintered at 1600 °C for 6 h and annealed at 1100 °C for 5 h in air. The highest transmittance reached 73% at 1000 nm when the calcination temperature was 1150 °C. The measured refractive index of Y 2 Ti 2 O 7 ceramics was higher than 2.24 at the wavelength range of 350–1000 nm, making it a promising candidate for optical devices. [ABSTRACT FROM AUTHOR]

Ethnopharmacological relevance Panax notoginseng (Burk.) F.H. Chen is a widely used traditional Chinese medicine known as Sanqi or Tianqi in China. This plant, which is distributed primarily in the southwest of China, has wide-ranging pharmacological effects and can be used to treat cardiovascular diseases, pain, inflammation and trauma as well as internal and external bleeding due to injury. Aims of the review This paper provides up-to-date information on investigations of this plant, including its botany, ethnopharmacology, phytochemistry, pharmacology and toxicology. The possible uses and perspectives for future investigation of this plant are also discussed. Materials and methods The relevant information on Panax notoginseng (Burk.) F.H. Chen was collected from numerous resources, including classic books about Chinese herbal medicine, and scientific databases, including Pubmed, SciFinder, ACS, Ebsco, Elsevier, Taylor, Wiley and CNKI. Results More than 200 chemical compounds have been isolated from Panax notoginseng (Burk.) F.H. Chen, including saponins, flavonoids and cyclopeptides. The plant has pharmacological effects on the cardiovascular system, immune system as well as anti-inflammatory, anti-atherosclerotic, haemostatic and anti -tumour activities, etc. Conclusions Panax notoginseng is a valuable traditional Chinese medical herb with multiple pharmacological effects. This review summarizes the botany, ethnopharmacology, phytochemistry, pharmacology and toxicology of P. notoginseng , and presents the constituents and their corresponding chemical structures found in P. notoginseng comprehensively for the first time. Future research into its phytochemistry of bio-active components should be performed by using bioactivity-guided isolation strategies. Further work on elucidation of the structure-function relationship among saponins, understanding of multi-target network pharmacology of P. notoginseng , as well as developing its new clinical usage and comprehensive utilize will enhance the therapeutic potentials of P. notoginseng. [ABSTRACT FROM AUTHOR]

Transparent YAG ceramics with different Ce 3+ doping concentrations and various sample thickness have been fabricated via solid-state sintering under vacuum, for the purpose of high power white light emitting diodes (WLEDs). Their phase compositions were checked by X-ray diffraction (XRD). Optical and luminescence characteristics were investigated by transmittance, absorption spectra and photoluminescence examinations. It is found that by altering the Ce 3+ concentration and sample thickness, the CIE color coordinates of the assembled LED devices can be tailored to white light region. More importantly, the color rendering index (CRI) of the LED devices got higher with decreased Ce 3+ doping concentration and sample thickness. Meanwhile, the effect of Ce 3+ concentration on the CRI was found more significant compared to that of the sample thickness. This study provides an efficient approach to tailor the luminescence properties, especially to improve the CRI of the WLEDs. [ABSTRACT FROM AUTHOR]

Highly transparent LaYZr 2 O 7 ceramic was obtained by vacuum sintering at 1800 °C for 6 h. The raw LaYZr 2 O 7 powder was synthesized by combustion method, and LaYZr 2 O 7 green body was obtained by slip casting. The in line transmittance and refractive index of the LaYZr 2 O 7 ceramic were 74.3% and 2.07 respectively at the wavelength of 633 nm. [ABSTRACT FROM AUTHOR]

Nb-doped and Y-deficient yttrium aluminum garnet ceramics were designed and synthesized using the solid-state reaction method according to the chemical equation Y 3−x Al 5 Nb x O 12+x (0 ≤ x ≤ 0.16). The phase composition, sintering behavior, microstructure, and microwave dielectric properties were investigated as functions of the composition and sintering temperature. A single-phase solid solution of yttrium aluminum garnet structure formation was observed in the range of 0 ≤ x ≤ 0.1. Further increments in x prompted the precipitation of the YNbO 4 secondary phase at the grain boundary of Y 3 Al 5 O 12. The complexity of the phase composition degrades the micromorphology and dielectric properties of the ceramics to varying degrees. Transmission electron microscopy results show that the lattice exhibits additional symmetry, which is closely related to the ultrahigh Q×f values of the ceramics. Effectively improving the sintering behaviour and suppressing the secondary phase by simultaneously doping with Nb5+ and reducing the yttrium stoichiometry. Finally, excellent microwave dielectric properties of ε r ~ 10.99, Q×f ~ 280,387 GHz (13.5 GHz), and τ f ~ − 34.7 ppm/°C can be obtained in x = 0.1 (Y 2.9 Al 5 Nb 0.1 O 12.1) sintered at 1700 °C for 6 h. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced fused silica composites exhibit the advantages of excellent mechanical properties, high heat resistance, low thermal expansion and low density, but low impact resistance or toughness. A novel modified slurry impregnation and hot pressing (SIHP) method was adopted to fabricate a new type of three dimensional orthogonal woven structure carbon fiber reinforced silica ceramic matrix composites (3D Cf/SiO 2 CMCs) with higher density and lower porosity. Physical characterization, flexural behavior, impact performance and toughening mechanism of the composites were investigated by three-point bending tests, impact tests, and scanning electron microscopy analysis. The 3D Cf/SiO 2 CMC showed a higher flexural strength in both warp (201.6%) and weft (263.6%) directions than those of pure SiO 2 and failed at a non-brittle mode due to the fiber debonding and pullout, and a delaminated failure of the 3D preform. The maximum impact energy absorption of the 3D Cf/SiO 2 CMC was 96.9 kJ/m 2 , almost 4 times as much as those for typical other carbon fiber reinforced CMCs. [ABSTRACT FROM AUTHOR]