Towards Highly‐Efficient Phototriggered Data Storage by Utilizing a Diketopyrrolopyrrole‐Based Photoelectronic Small Molecule

A cooperative photoelectrical strategy is proposed for effectively modulating the performance of a multilevel data‐storage device. By taking advantage of organic photoelectronic molecules as storage media, the fabricated device exhibited enhanced working parameters under the action of both optical and electrical inputs. In cooperation with UV light, the operating voltages of the memory device were decreased, which was beneficial for low energy consumption. Moreover, the ON/OFF current ratio was more tunable and facilitated high‐resolution multilevel storage. Compared with previous methods that focused on tuning the storage media, this study provides an easy approach for optimizing organic devices through multiple physical channels. More importantly, this method holds promise for integrating multiple functionalities into high‐density data‐storage devices.     

Vibration-driven Reduction of CO2 to Acetate with 100 % Selectivity by SnS Nanobelt Piezocatalysts

Converting CO₂ into high-value C2 chemicals such as acetate with high selectivity and efficiency is a critical issue in renewable energy storage. Herein, for the first time we present a vibration-driven piezocatalysis with tin(II) monosulfide (SnS) nanobelts for conversion of CO₂ to acetate with 100 % selectivity, and the highest production rate (2.21 mM h⁻¹) compared with reported catalysts. Mechanism analysis reveal that the polarized charges triggered by periodic mechanical vibration promote the adsorption and activation of CO₂. The electron transfer can be facilitated due to built-in electric field, decreased band gap and work function of SnS under stress. Remarkably, reduced distance between active sites leads to charge enrichment on Sn sites, promoting the C−C coupling, reducing the energy barriers of the rate determining step. It puts forward a bran-new strategy for converting CO₂ into high-value C2 products with efficient, low-cost and environment-friendly piezocatalysis utilizing mechanical energy.     

Rapid and simultaneous determination of multiple classes of abused drugs and metabolites in human urine by a robust LC‐MS/MS method – application to urine drug testing in pain clinics

A simple LC‐MS/MS method was developed and validated for quantitatively analyzing six classes of 26 abused drugs and metabolites in human urine: (1) illicit drugs; (2) opiates; (3) synthetic opioids; (4) sedative; (5) stimulants; and (6) γ‐aminobutyric acid analogs. All urine samples were diluted with a mixture of isotope‐labeled internal standards, hydrolyzed with β‐glucuronidase and directly injected in a gradient chromatographic run. The mobile phase was composed of 0.1% formic acid in water and 0.1% of formic acid in methanol. A 4.9 min run time using the multiplexing driver and ultra‐biphenyl column (50 × 2.1 mm, 5 µm, RESTEK) allowed all drugs to have sufficient resolution in a short elute time. The overlapping liquid chromatography runs and scheduled multiple reaction monitoring acquisition method resulted in a higher overall throughput for the system. The result was linear over the studied range (2–16,000 ng/mL) for all compounds with correlation coefficients r² ≥ 0.995. The intra‐day and inter‐day precisions and accuracies were within 15% and recovery was between 83 and 115% for all analytes. Freeze–thaw stability for three cycles and long‐term stability (57 days, ?20°C) were established for all analytes. The cross‐validation between College of American Pathologists and in‐house was validated (0.06% ≤ bias ≤ 12.3%). The applicability of the method was examined by analyzing urine samples from chronic pain patients (n = 610). Copyright © 2013 John Wiley & Sons, Ltd.     

LC and LC–MS Study of the Bioavailability and Metabolites of TM208 after Oral and Intravenous Administration to Rat

4-Methylpiperazine-1-carbodithioic acid 3-cyano-3,3-diphenylpropyl ester hydrochloride (TM208) is a new compound expected to become a new drug because of excellent in vivo and in vitro anticancer activity and low toxicity. A new, specific and sensitive LC method was set up for detecting the bioavailability of TM208 after oral administration. Samples were extracted with ethyl acetate after oral and intravenous administration. The retention times of TM208 and plunarizine (I.S.) were 5.5 and 9.9 min, respectively. The linear range was 0.125–50 μg mL^?1. The accuracy (error, %) for three concentrations was 2.7–16.6%. Intra-day precision (as RSD) was 1.6–6.9% and inter-day precision was 7.6–11.5%. Extraction recovery of TM208 was 84.15–89.51% and that of the I.S. was 83.3%. Results from stability testing indicated that samples should be analyzed within 24 h or frozen immediately for later analysis. The bioavailable fraction (F) calculated by use of a non-compartment model was 63.3%. Pharmacokinetic data for TM208 were: mean residence time 24.3 and 5.1 h, V _d 186.2 and 35.5 L kg^?1, and Cl 6.9 and 4.2 L h^?1 kg^?1 after oral and intravenous administration, respectively. LC–MS comparison of the metabolites after the two methods of administration showed the kind and content of metabolites of TM208 in rat urine after intravenous administration were more than after oral administration. The experimental results show that the low anticancer activity of TM208 after intravenous administration is related to rapid elimination of the drug, and that the kind and content of metabolites do not affect the bioactivity of TM208.     

Synthesis and Application of a Full Water‐Soluble and Red‐Emitting Chemosensor Based on Phenoxazinium for Copper(II) Ions

A phenoxazinium‐based chemosensor ( 1 ) bearing di(2‐picolyl)amine unit was successfully synthesized. The result shows that it is a red‐emitting and full water‐soluble chemosensor for the selective detection of Cu²⁺ in pure water. The fluorescence on‐off mechanism was studied by ab initio calculations. To confirm the suitability of 1 for biological applications, it was employed in the fluorescence detection of the intracellular Cu²⁺ with cultured KB cells. The results indicated that 1 had good membrane permeability and could be useful for the fluorescence microscopic imaging.     

Catalytic epoxidation of stilbene with FePt@Cu nanowires and molecular oxygen

A novel FePt@Cu nanowire catalyst was prepared by the reduction of Cu(acac)(2) on the surface of FePt nanowires, in oleylamine (OAm). This nanowire catalyst efficiently epoxidised stilbene in the presence of molecular oxygen, and the conversion and selectivity were maintained with repeated use of the catalyst, compared with recycled catalyst.     

Copper-catalyzed oxidation of azolines to azoles

We report herein convenient, aerobic conditions for the oxidation of thiazolines to thiazoles and data regarding the oxidation mechanism. These reactions feature operationally simple and environmentally benign conditions and proceed in good yield to afford the corresponding azoles, thus enabling the inexpensive preparation of valuable molecular building blocks. Incorporation of a novel diimine-ligated copper catalyst, [((Mes)DAB(Me))Cu(II)(OH(2))(3)](2+) [(-)OTf](2), provides increased reaction efficiency in many cases. In other cases copper-free conditions involving a stoichiometric quantity of base affords superior results.     

A study of the spreading scheme for viral marketing based on a complex network model

Buzzword-based viral marketing, known also as digital word-of-mouth marketing, is a marketing mode attached to some carriers on the Internet, which can rapidly copy marketing information at a low cost. Viral marketing actually uses a pre-existing social network where, however, the scale of the pre-existing network is believed to be so large and so random, so that its theoretical analysis is intractable and unmanageable. There are very few reports in the literature on how to design a spreading scheme for viral marketing on real social networks according to the traditional marketing theory or the relatively new network marketing theory. Complex network theory provides a new model for the study of large-scale complex systems, using the latest developments of graph theory and computing techniques. From this perspective, the present paper extends the complex network theory and modeling into the research of general viral marketing and develops a specific spreading scheme for viral marking and an approach to design the scheme based on a real complex network on the QQ instant messaging system. This approach is shown to be rather universal and can be further extended to the design of various spreading schemes for viral marketing based on different instant messaging systems.     

Study of Linear and Nonlinear Optical Properties of Four Derivatives of Substituted Aryl Hydrazones of 1,8‐Naphthalimide

Four 1,8‐naphthalimide hydrazone molecules with different electron‐donating groups have been applied in the study of linear and nonlinear optical (NLO) properties. These compounds showed strong green emission in solution. Their NLO properties such as two‐photon absorption (TPA) behavior with femtosecond laser pulses ca. 800 nm and excited‐state absorption (ESA) behavior with nanosecond laser pulses at 532 nm were investigated. Compound 4 presented the largest two‐photon cross section (550 GM) among them due to two factors: the conjugated length of compound 4 is the longest and the electron‐donating ability of compound 4 is the strongest. Different from TPA behavior, compound 2 showed the best nonlinear absorption properties at 532 nm and its nonlinear absorption coefficient and third‐order nonlinear optical susceptibilities χ ⁽³⁾ were up to 1.41×10^?10 MKS and 4.65×10^?12 esu, respectively. Through the modification of the structure, the nonlinear optical properties of these compounds at different wavelengths (532 and 800 nm) were well tuned. The great broad‐band nonlinear optical properties indicate hydrazones are good candidates for organic nonlinear optical absorption materials.     

立方Nd2O3上过氧物种光诱导生成的18O同位素示踪考察

采用原位显微Raman光谱和¹⁸O同位素示踪技术,以325 nm激光为激发光源,对立方Nd₂O₃上过氧物种的光诱导生成过程进行了详细表征,进一步证实过氧源于分子氧对晶格氧的氧化反应. 结果还表明,325 nm激光在室温下即可诱导过氧的生成,在实验条件下,生成的过氧物种可与Nd₂O₃的晶格氧发生快速的氧交换反应,位于Nd₂O₃体相的晶格氧也可迁移至样品表层进而参与过氧的生成. 325 nm激光照射有助于促进晶格氧的迁移以及晶格氧与分子氧之间的氧交换反应.