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In this study, a series of (Ba 0.95 Ca 0.05 )(Ti 0.90 Sn 0.10 )O 3 – x LiF (BCTS– x LiF) (0≤ x ≤6 mol%) lead-free piezoceramics were fabricated by a conventional solid-state reaction method. The incorporation of LiF could significantly improve the sinterability of BCTS ceramics by reducing the sintering temperature from 1480 °C to 1250 °C, where a relative density over 90% was achieved with grown grains of 5–20 μm. X-ray diffraction and Raman spectroscopy experiments revealed that BCTS– x LiF ceramics are composed of coexisting R – O – T phases at 0≤ x ≤1 and R – T phases at 2≤ x ≤6 at room temperature. Optimal piezoelectric properties of d 33 =510 pC/N, k p =40.9%, ε r =5370, tan δ =0.019 and d S /d E =961 pm/V were obtained at x =5, which is attributed to the coexistence of R and T phases with an optimum ratio at room temperature and dense structure with large grains. [ABSTRACT FROM AUTHOR]

Ultrahigh piezoelectric constant (d33 = 683 pC/N) and converse piezoelectric coefficient (dS/dE = 1257 pm/V) were observed in CuO-doped lead-free (Ba,Ca)(Ti,Sn)O3 ceramics at an optimal composition fabricated by a conventional sintering method at a low temperature 1250 °C. Since all samples showed a pure perovskite structure with coexisting multiphases including cubic, tetragonal, orthorhombic, and rhombohedral phases around two converged triple points, a good compositional stability of high piezoelectricity along with a high d33 and dS/dE over 600 pC/N and 1000 pm/V was achieved within a wide compositional region (1.0 ≤ x ≤ 3.0) regardless of the CuO content (x). [ABSTRACT FROM AUTHOR]

A Ser105Ala mutant of the lipase B from Candida antarctica enables 'perhydrolase-only' reactions. At the example of the chemoenzymatic Baeyer-Villiger oxidation of cyclohexanone, we demonstrate that with this mutant selective oxidation can be achieved in deep eutectic solvent while essentially eliminating the undesired hydrolysis reaction of the product. [ABSTRACT FROM AUTHOR]

A high piezoelectricity enhancement achieved in (Ba,Ca)(Ti,Sn)O 3 lead-free ceramics sintered with 4 mol% Li 2 O additives by intensifying effect of sintering temperature ( T S ) in a wide interval (1300–1450 °C) has been found to be related to both the point defects and phase structures. X-ray photoelectron spectroscopy confirmed a reduction of tetravalent cations in B-sites to lower valence state such as Ti 3+ and Sn 2+ along with an increased content as raising T S . Photoluminescence spectra indicated higher oxygen vacancy concentrations as T S is too low or too high than those at an intermediate T S range, which is attributed to the volatilization of Li + and the inadequate oxygen supply in environment at high T S . Owing to coexisting rhombohedral and tetragonal phases at room temperature, a high piezoelectric coefficient d 33 up to 578 pC/N was achieved as T S =1350 °C. [ABSTRACT FROM AUTHOR]

This work investigated the enhanced sintering and electrical properties of (Ba 0.95 Ca 0.05 )(Ti 0.90 Sn 0.10 )O 3 - x Li 2 O (BCTSLi x , x = 0, 1, 2, 3, 4, 5 and 6 mol%) lead-free piezoelectric ceramics benefiting from the Li 2 O addition. Highly dense BCTS ceramics with good piezoelectric properties were fabricated at reduced sintering temperatures by adding a small amount of Li 2 O. It was found that the sintering densification is promoted mainly by reaction liquid phase at the early sintering stage and the formation of oxygen vacancies should be considered as an additional factor. The coexistence of R and T phases was confirmed by the Raman spectrum at a temperature range from−50 °C to 40 °C as x = 2 and at room temperature for all other Li 2 O added samples, while their specific ratio of R to T phase decreases with increasing Li 2 O addition. Better properties with d 33 = 457 pC/N, k p = 25.18% and Q m = 491 were obtained when adding 4 mol% Li 2 O, which are attributed dominantly to the appropriate specific ratio of R to T phase because of the similar grain size and density for samples at 3 ≤ x ≤ 6. [ABSTRACT FROM AUTHOR]

A series of Li2 CO3-added ( Ba0.95 Ca0.05)( Ti0.90 Sn0.10) O3 ( BCTS) ceramics were prepared by normal sintering at a low temperature of 1300°C; Their microstructure and electrical property evaluation were investigated with special emphases on the effect of Li2 CO3 addition. Adding Li2 CO3 significantly improves the sinterability of BCTS ceramics, resulting in a reduced sintering temperature by more than 150°C. The coexistence of R and T phases is confirmed by the Raman spectrum at room temperature for all samples and at a temperature range from −80°C to 40°C for sample with 3% mol Li2 CO3 addition. The specific ratio of R to T phase decreases with increasing temperature or Li2 CO3 addition. A higher εr is observed in T phase compared to R phase in the studied BCTS system. Better properties with d33 = 485 pC/N, kp = 39%, and Qm = 191 were obtained for BCTS sample with 3% mol Li2 CO3 addition, which is attributed to the increased grain size and density along with the variation in the specific ratio of R to T phase. [ABSTRACT FROM AUTHOR]

BaCa xTiO3-0.04LiF (0.010 ≤ x ≤ 0.045) ceramics were prepared by normal sintering at 1100 °C in air. A two-phase coexisted region across orthorhombic and rhombohedral symmetry was designed by refining the components. The detailed phase structure was analyzed quantitatively by the Rietveld refinement. BaCa0.035TiO3-0.04LiF ceramic showed better properties with d33 = 354 pC N−1, kp = 39%, Qm = 314, and TC = 65 °C, in which the relative proportion of rhombohedral symmetry was 74.86%, the grain size was 6.0 µm and the relative density was 91%, indicating that the synergistic effect of the phase structure, fine grain, and relatively high density contributed to the outstanding piezoelectric properties. [ABSTRACT FROM AUTHOR]

Abstract: The total syntheses of norartocarpin and artocarpin, two biologically interesting natural flavonoids with two regioisomeric isoprenyl side chains, were achieved for the first time via a linear reaction sequence of 9 and 12 steps with the overall yields of 14% and 3.5%, respectively, starting from commercially available 1,3,5-trimethoxybenzene. [Copyright &y& Elsevier]

Orange juice is a kind of fruit juice with huge market share. The most common adulteration is the addition of mandarin juice and grapefruit juice. Therefore, it is necessary to develop a method that can simultaneously detect mandarin and grapefruit components in orange juice. In this study, the specific site of the trnL-trnF gene of mandarin and the specific site of the accD-psaI gene of grapefruit were used for digestion and capillary electrophoresis separation to establish a duplex PCR–RFLP–CE method of simultaneous detection of mandarin and grapefruit components. By this method, the detection limits of mandarin and grapefruit components were 5% and 2.5%, respectively. About the specificity, only the 83–177 bp amplified bands of mandarin and grapefruit were specifically digested, while none of them were cut in the 8 kinds of fruits such as pear, apple, peach, papaya, pineapple, hawthorn, grape and banana. Duplex PCR–RFLP–CE tests were performed on the 8 commercially available fruit juices. As a result, grapefruit components were found in orange juice (C5) and other ingredients to be identified in grapefruit juice (C8). The established duplex PCR–RFLP–CE method can provide an effective detection method for orange juice adulteration in the future. [ABSTRACT FROM AUTHOR]

The incorporation of unsaturated [Mn(1,2-dap)] 2+ , [Mn(1,2-dap) 2 ] 2+ , [Mn(2,2-bipy)] 2+ (1,2-dap=1,2-diaminopropane) complex cations with thioarsenate anions of [As III S 3 ] 3− and [As V S 4 ] 3 − led to three new hybrid manganese thioarsenates, namely, [Mn(1,2-dap)] 2 MnAs 2 S 6 ( 1 ), [Mn(1,2-dap) 2 ]{[Mn(1,2-dap)] 2 As 2 S 8 } ( 2 ) and (NH 4 )[Mn(2,2-bipy) 2 ]AsS 4 ( 3 ). In compound 1 , the unsaturated [Mn(1,2-dap)] 2+ complexes, [MnS 4 ] 6− tetrahedra and [As III S 3 ] 3− trigonal-pyramids are condensed to form the 1D [Mn(1,2-dap)] 2 MnAs 2 S 6 chain, whereas compound 2 features 2D layer composed of [Mn(1,2-dap)] 2+ and [Mn(1,2-dap) 2 ] 2+ complexes as well as [As V S 4 ] 3− tetrahedral units. For compound 3 , two [As V S 4 ] 3− anions bridge two [Mn(2,2-bipy)] 2+ complex cations into a butterfly like {[Mn(2,2-bipy)] 2 As 2 S 8 } 2 − anionic unit. Magnetic measurements indicate the ferrimagnetic behavior for compound 1 and antiferromagnetic (AF) behaviors for compounds 2–3 . The UV–vis diffuse-reflectance measurements and electronic structural calculations based on density functional theory (DFT) revealed the title compounds belong to semiconductors with band gaps of 2.63, 2.21, and 1.97 eV, respectively. The narrow band-gap of compound 3 led to the efficient and stable photocatalytic degradation activity over organic pollutant than N-doped P25 under visible light irradiation. [ABSTRACT FROM AUTHOR]

Homogeneous dual-ligand zinc complex catalysts was developed for the synthesis of propylene carbonate (PC) through chemical fixation of CO. It was found that among a number of various p K N-donor ligands, the catalytic performance was enhanced dramatically and the corrosion of the reaction system was effectively inhibited when 1-methylimidazol (1MI) was used as the N-donor ligand, in which >90 % PC yield could be obtained under mild reaction conditions. The dual-ligand zinc complex catalysts were characterized by various spectroscopic techniques such as FT-IR and HNMR. X-ray crystallography showed that the Zn(II) atom was coordinated in tetrahedron geometry by three bromine atom, one 1MI nitrogen atom, and one crystallographically independent cation to give a 3D tetrahedron structure, which forms tetracoordinated complexes. The structure of the complex gives the reasons for the enhancement of the catalytic activity from the microscopic molecular structure point of an extremely long and therefore labile Zn-Br bond, the diversification of the bond angles, and the interplay between the steric hindrance, which have great influence on the interaction forces of Zn-Br. Graphical Abstract: [Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Background. Pigment epithelium-derived factor (PEDF) is demonstrated to be elevated in diabetes patients. However, no reports have emerged in pregnant women with gestational diabetes mellitus (GDM). This study was undertaken to investigate serum PEDF levels in GDM women and to evaluate PEDF as a biomarker to predict diabetes postpartum. Methods. Serum PEDF concentration and clinical characteristics were detected in the pregnant women with GDM (n = 120) and without GDM (control group, n = 120). Results. PEDF levels were elevated in subjects with GDM versus controls. Univariate correlations showed that serum PEDF levels were positively correlated with fasting glucose and fasting insulin levels, respectively, and negatively correlated with adiponectin. Receiver operating characteristic (ROC) analysis demonstrated that the AUC of serum PEDF for diabetes mellitus in women postpartum was 0.893. Conclusion. Serum PEDF was elevated in pregnant women with GDM, which is probably an early detection marker for predicting development of GDM to diabetes mellitus. [ABSTRACT FROM AUTHOR]

Abstract: The polymorphic phase transition (PPT) from tetragonal to orthorhombic symmetry was tailored in lead-free piezoelectric ceramics Li0.08(Na0.52+x K0.48)0.92NbO3 (LN0.52+x KN) by controlling excess Na content, which is opposite to the usually reported orthorhombic–tetragonal phase transition. The grain growth was accelerated by adding excess Na, resulting in an increased grain size from 2–3μm to 7–8μm and a bimodal grain size distribution for samples x=0.015–0.04. The optimized piezoelectric properties with, i.e. d 33=226pC/N and k p=36.8% were obtained in sample x=0.04 due to the PPT effect. The corresponding T C, P r, and E r were 468°C, 25.5μC/cm2 and 1.20kV/mm, respectively. [Copyright &y& Elsevier]

( Ba1− x Ca x)( Ti0.92 Sn0.08) O3 ( x = 0.00-0.06 mol) ceramics with a high relative density over 96% were prepared by a conventional sintering method at 1480°C. At room temperature, a polymorphic phase transition from orthorhombic phase to tetragonal phase was confirmed by the XRD patterns in the composition range of 0.04 ≤ x ≤ 0.06. A high piezoelectric coefficient d33 up to 568 pC/N was obtained at x = 0.05 mol, which is higher than the other component of ( Ba, Ca)( Ti, Sn) O3 system. At the same time, the corresponding planar electromechanical coupling factor kp, converse piezoelectric coefficient dS/ dE, and dielectric constant εr reach 47.7%, 1013 pm/V, and 23000, respectively. These results indicate that the ( Ba, Ca)( Ti, Sn) O3 ceramics are a promising candidate to replace for the lead-based piezoelectric materials. [ABSTRACT FROM AUTHOR]

The phase structure in the (Ba,Ca)(Ti1-xSnx)O3 lead-free ceramics was evolved from inceptive orthorhombic (O) at 0 ≤ x ≤ 0.04 to a two-phase coexistence of pseudocubic-orthorhombic (PC-O) at 0.06 ≤ x ≤ 0.10 and further to a multiphase coexistence of rhombohedral-pseudocubic-orthorhombic (R-PC-O) at x = 0.11. Due to the multiphase coexistence of R-PC-O at room temperature proved by X-ray diffraction, dielectric constant [variant_greek_epsilon]r and differential scanning calorimetry, an ultrahigh piezoelectric coefficient d33 = 670 pC/N and electrostrain 0.061% were achieved. The high d33 over 520 pC/N was stabilized in a wide compositional range of 0.07 ≤ x ≤ 0.11, suggesting that (Ba,Ca)(Ti,Sn)O3 ceramics are a promising candidate for the lead-free piezoelectric ceramics. [ABSTRACT FROM AUTHOR]