Basil Seed Inspired Design for a Monodisperse Core–Shell Sn@C Hybrid Confined in a Carbon Matrix for Enhanced Lithium‐Storage Performance

Tin anode materials have attracted much attention owing to their high theoretical capacity, although rapid capacity fade is commonly observed mainly because of structural degradation resulting from volume expansion. Herein, we report a versatile strategy based on a basil seed inspired design for constructing a monodisperse core–shell Sn@C hybrid confined in a carbon matrix (Sn basil seeds). Analogous to the structure of basil seeds soaked in water, Sn basil seeds are used to tackle the volume expansion problem in lithium‐ion batteries. Monodisperse Sn cores are encapsulated by a thick carbon layer, which thus lowers the electrolyte contact area. The obtained Sn basil seeds are closely packed to construct a framework that supplies fast electron transport and provides a reinforced mechanical backbone. As a consequence, an ensemble of this hybrid network shows significantly enhanced lithium‐storage performance with a high capacity of 870 mAh g^?1 at a current density of 0.4 A g^?1 over 600 cycles. After the intense cycling, the Sn cores transform into ultrafine nanocrystals with sizes of 3–6 nm. The structural and morphological evolution of the Sn cores can reasonably explain the gradual increase in the capacity and the long‐term cycling ability of our Sn basil seeds.     

Biomarkers of alcohol abuse in racehorses by liquid chromatography/tandem mass spectrometry

A rapid and sensitive method was developed for the screening, quantification and confirmation of ethyl glucuronide (EG) and ethyl sulfate (ES) as biomarkers for alcohol administration to racehorses using liquid chromatography coupled on-line with triple quadrupole tandem mass spectrometry. Urine sample aliquots (0.1 mL) were pre-treated by protein precipitation. Separation of EG and ES was achieved on an Ultra PFP column. Isocratic elution with a flush step was performed using 0.1% formic acid in water (A) and 0.1% formic acid in acetonitrile (B). Analysis was performed by negative electrospray ionization in multiple reaction monitoring mode. The retention times for EG and ES were 1.7 +/- 0.30 and 3.4 +/- 0.30 min, respectively. The internal standard used was d(5)-ethyl glucuronide with a retention time of 1.7 +/- 0.30 min. The entire separation was completed in <5 min. The limit of detection (LOD) and of quantification (LOQ) for both analytes were 100 ng/mL (S/N > or =3) and 500 ng/mL, respectively. The limit of confirmations (LOC) for EG and ES were 500 ng/mL and 1.0 microg/mL, respectively. The assay was linear over a concentration range of 0.5-100 microg/mL (r(2) > 0.995). Intra- and inter-day accuracy and precision were less than 15%. The analytes were stable in urine for 24 h at room temperature, 10 days at 4 degrees C and 21 days at -20 degrees C and -70 degrees C. Ion suppression or enhancement due to matrix effect was negligible. The measurement uncertainty was <14% for EG and <25% for ES. This method was successfully used for the quantification of EG and ES in urine samples following alcohol administration to research horses and for screening and confirmation of EG and ES in urine samples obtained from racehorses post-competition. The method is simple, rapid, inexpensive, and reliably reproducible.     

Hydrothermal synthesis of Na(0.5)La(0.5)TiO3-LaCrO3 solid-solution single-crystal nanocubes for visible-light-driven photocatalytic H2 evolution

Cubic perovskite structure photocatalysts of Na(0.5)La(0.5)TiO(3) and (Na(0.5)La(0.5)TiO(3))(1.00)(LaCrO(3))(0.08) solid solution that consisted of well-defined single-crystal nanocubes were successfully prepared by means of facile and surfactant-free hydrothermal reactions for the first time. The results from different instrumental characterizations and theoretical calculations consistently confirmed the formation of nanocubic single-crystal solid solution of (Na(0.5)La(0.5)TiO(3))(1.00)(LaCrO(3))(0.08), and clearly revealed the modification of its physicochemical properties compared with those of Na(0.5)La(0.5)TiO(3). In particular, the effective narrowing of the bandgap (from 3.19 to 2.25 eV) by Cr(3+) in the solid solution made it possible to utilize visible light. The solid-solution configuration maintained the charge balance to preserve the valence of Cr(3+) rather than Cr(6+), and accommodated Cr(3+) with high content to form new energy bands instead of localized impurity levels. The hydrothermal preparation strategy ensured the formation of single crystals with high purity, few defects, and regulated morphology; it also guaranteed the valences of Ti(4+) and Cr(3+) in the solid solution. Consequently, the recombination of photogenerated carriers could be effectively suppressed to benefit photocatalytic H(2) evolution. (Na(0.5)La(0.5)TiO(3))(1.00)(LaCrO(3))(0.08) nanocubic single-crystal solid solution showed stable photocatalytic activity, and thus was proved to be a promising candidate for visible-light-driven photocatalytic H(2) evolution.     

Microchip electrophoresis coupled with on-line magnetic separation and chemiluminescence detection for multiplexed immunoassay

A facile and universal strategy for multiplexed immunoassay is proposed. The strategy is based on microchip electrophoresis (MCE) coupled with on-line magnetic separation and chemiluminescence (CL) detection. The system consisted of a microchip, an electromagnet, and a photomultiplier. The realization of multiplexed immunoassay protocol involves sampling magnetic nanoparticles (MNPs) labeled antibodies, N-(4-aminobutyl)-N-ethyl-isoluminol (ABEI) labeled antigens and free antigens in the precolumn reactor, on-line immunoreaction, capturing the MNPs-immunocomplexes, and the separation of unconjugated ABEI-labeled antigens. After on-line magnetic separation, the free ABEI-labeled antigens were transported into the separation channel, and mixed with hydrogen peroxide (H(2) O(2) ) in the presence of horseradish peroxidase in the postcolumn reactor, and producing CL emission. Using this arrangement, multiple analytes could be measured simultaneously by performing the technical operations for a single assay. As a proof-of-concept, the multiplexed immunoassay was evaluated for the simultaneous determination of five model analytes (i.e. hydrocortisone, corticosterone, digoxin, testosterone, and estriol). The results exhibited excellent precision and sensitivity, the relative standard deviations for nine times detection were lower than 4.7% for all the five components, and the detection limits of five analytes were in the range of 3.6-4.9 nM. The MCE system was validated using two human serum-based control samples containing five analytes.     

Two new diterpenoids from the buds of Wikstroemia chamaedaphne

Two new diterpenoids, wikstroelide Q (1) and prostratin Q (5), together with three known diterpenoids, pimelea factors P? (2), P? (3), and prostratin (4), and five known lignans, (+)-epipioresinol (6), (+)-isolariciresinol (7), (?)-lariciresinol (8), (+)-epi-sesaminone (9), and prestegane B (10), were isolated from the buds of Wikstroemia chamaedaphne Meissn. Their structures were elucidated by a combination of spectroscopic analyses. Compounds 1–10 were evaluated for their cytotoxicities against HL-60, SMMC-7721, A549, MCF-7, SW480, and BEAS-2B cell lines in vitro.     

Introducing chemiluminescence resonance energy transfer into immunoassay in a microfluidic format for an improved assay sensitivity

We report on a novel strategy to improve microfluidic immunoassay sensitivity by introducing chemiluminescence resonance energy transfer (CRET) into the immunoreactions. The proposed CRET-based immunoassay for estradiol (E2, as a model analyte) is one of the most sensitive immunoassay with a limit of detection at 3.6 × 10(-11) M E2 in a microfluidic format.     

Large inverse relaxation of photoinduced birefringence in an azobenzene-containing ionic self-assembly complex

Photoinduced anisotropy and polarization holographic recording were investigated in an azobenzene-containing ionic self-assembly complex. The complex film was found to possess large photoinduced dichroism (D～0.36) and photoinduced birefringence (Δn～10^?2). A noteworthy observation was that the photoinduced birefringence did not show any decay, but strongly increased after switching off the pump light at room temperature. The diffracted signals of the polarization holographic gratings, written by two orthogonally linear and circular polarized beams respectively, exhibited similar inverse relaxation behavior as the photoinduced birefringence after switching off the writing lights. A discussion about the mechanism accounting for the abnormal relaxation process of photoinduced birefringence is presented.     

聚合物弥散液晶材料在1550nm的电光特性研究

实验研究了不同配方及工艺条件下,聚合物弥散液晶（PDLC）材料在1550nm处的电控光透射特性。由此筛选合适的配方和工艺,研制了聚合物弥散液晶电控可调光衰减器样品。实验说明,在1550nm工作点,50％左右合适的液晶含量的聚合物弥散液晶样品能够获得更好的电控光学性能。采用配方质量比ω（DHPA）：ω（E7）：ω（RB）：ω（NVP）：ω（NPG）=100：100：3：2：1．5的配方,制作在1550nm工作的聚合物弥散液晶光衰减器样品。经检测,输入光源为1550mm,223μW时,器件插入损耗为2．3dB,衰减调节范围为13dB,线性工作区域为20～70V。     

一种改进的图像组合滤波方法

利用小波阈值去噪和Wiener滤波的特点,在文献［7］的基础上提出了一种改进的组合滤波方法,在进行空域自适应滤波之前,先对经BayesShrink处理过的预去噪图像重新估计其噪声方差,通过数值计算给出了该噪声方差的一种近似最优估计公式.实验结果表明该方法在去噪图像的均方误差和对不同图像的适应性方面都得到了改善.     

A Polyaza Macrocycle Ligand Bearing Anthracenyl Fluorophores for Selective Signaling of Zn(II) in Aqueous Solution

Based on a metal-template synthetic strategy, a new polyaza macrocycle bearing two anthracenyl fluorophores ligand, N,N′-bis[(anthracen-10-yl)methylene]-5,6,8,9,14,15,17,18-octahydrodibenzo[f,m][1,3,5,8,10,12]hexaazacyclotetradecine-7,16-diamine (L), was prepared and fully characterized. In the presence of Zn(II), L displayed remarkable chelation-enhanced fluorescence and can selectively respond to the presence of Zn(II) ion compared with other cations in HEPES-buffered aqueous methanol solutions. Results obtained from UV–Vis and fluorescence titrations indicated that L chelates to Zn(II) by forming a complex with a 1:1 molar ratio.