Microcalorimetric study of the effect of artesunate on the growth metabolism of mitochondria isolated from rat liver

In this study, the metabolic thermogenic curves of mitochondria isolated from rat liver tissue were drawn, and the effects of artesunate on metabolic activity of mitochondria were studied using TAM Air Isothermal Microcalorimeter. After isolation from the rat liver, mitochondria still have metabolic activity and can live for a week with appropriate nutrients. With the addition of artesunate (7.5 μM/mL), the metabolic activity of mitochondria was completely lost at this concentration. From the thermogenic curves, we obtained the thermokinetic equations under different conditions: T _max = 2512.24 + 1761.53c, R = 0.9375; and Tlag (min) = 707.26 + 285.17c, R = 0.9846. The results showed that artesunate was a mitochondria-targeted drug having obvious effects on mitochondrial metabolism.     

Resonantly pumped Q-switched Er:GdVO4 laser

We describe a Q-switched Er:GdVO₄ laser resonantly pumped by a MgO-doped periodically poled LiNbO₃ optical parametric oscillator （MgO: PPLN OPO） at 1536 nm. In continuous-wave lasing, the maximum output power is 1.14 W with an incident pump power of 4.7 W and a slope efficiency of 27%. In Q-switched operation, 1.1 mJ of output pulse energy is achieved at 200 Hz. The upper-state lifetime at different pulse repetition frequencies is also calculated.     

Simultaneous determination of seven lignans in Justicia procumbens by high performance liquid chromatography–photodiode array detection using relative response factors

A simple and sensitive HPLC coupled with photodiode array (HPLC–PDA) method was developed for simultaneous determination of seven lignans in Justicia procumbens using relative response factors (RRFs). The chromatographic separation was performed on a Shiseido Capcell Pak C₁₈ column (250 × 4.6 mm id, 5 μm), a gradient elution of acetonitrile/water, and a photodiode array detector. The column temperature was maintained at 35°C and the detection wavelength was set at 256 nm. Chinensinaphthol methyl ether was selected as the reference compound for calculating the relative response factors of the lignans. It has shown that the RRFs for lignans are quite similar at 256 nm of detection under different analytical conditions (different columns and HPLC instruments). Using RRFs, not every lignan is needed as a reference standard, making the method ideal for rapid, routine analysis, especially for those laboratories where lignans standards are not readily available. An economic and practicable HPLC method using RRFs was established for the determination of seven lignans in J. procumbens. This method not only can determine multiple indexes in traditional Chinese medicines (TCMs) simultaneously, but also resolve the problem of lacking of chemical standards. It will be a good quality evaluation method and pattern for TCMs.     

Solvatochromic Behavior of Chiral Mesoporous Metal–Organic Frameworks and Their Applications for Sensing Small Molecules and Separating Cationic Dyes

Two anionic metal–organic frameworks (MOFs) with 1D mesoporous tubes ( 1 ) and chiral mesoporous cages ( 2 ) have been rationally constructed by means of a predesigned size‐extended hexatopic ligand, namely, 5,5′,5′′‐(1,3,5‐triazine‐2,4,6‐triyl)tris‐ (azanediyl)triisophthalate (TATAT). Charge neutrality is achieved by protonated dimethylamine cations. Notably, the two MOFs can be used to separate large molecules based on ionic selectivity rather than the size‐exclusion effect so far reported in the literature. Owing to the imino triazine backbone and carboxyl groups of the hexatopic ligand, which provide important host–guest interactions, rare solvatochromic phenomena of 1 and 2 are observed on incorporating acetone and ethanol guests. Furthermore, guest‐dependent luminescence properties of compound 2 were investigated, and the results show that luminescence intensity is significantly enhanced in toluene and benzene, while quenching effects are observed in acetone and ethanol. Thus, compound 2 may be a potential material for luminescent probes.     

Research on PAN Nascent Fiber Interior Microstructure through Ultrasonic Etching and Ultrathin Sectioning

The interior microstructures of polyacrylonitrile nascent fibers is studied by the scanning electronic microscopy and the high-resolution transmission electron microscopy through ultrasonic etching and ultrathin sectioning. Due to the orientation and fold of molecular chains, the lamellae of 50–80 nm in thickness are formed. A high number of pores, ranging from dozens to two hundred nanometers in diameters exist between the lamellae, which result from residual solvent. The fibril structure is formed in the nascent fiber during the coagulation process, which are oriented along the fiber axis. An uneven tensile stress distribution leads to the formation of skin-core structures in the nascent fiber during the dry-jet wet spinning process.     

Development of novel backwash cleaning technique for reverse osmosis in reclamation of secondary effluent

The objective of the study was to further develop a novel cleaning technique for reverse osmosis in reclamation of municipal secondary effluent. This technique is a new backwash method via direct osmosis (DO) by intermittent injection of the high salinity (HS) solution without stopping of high pressure pump and it is environment and membrane friendly technique. In the study, DO-HS trials were carried out with a UF-RO pilot system which was operated on site with the secondary treated effluent as the raw feed. Different operating conditions for DO-HS treatment in the actual process were investigated. It was found that the operation for implementation of the DO-HS cleaning technique developed was easy. For the first time, the actual profiles of HS concentration, DO backwash flow rate, brine flow rate and permeate pressure during DO-HS treatment have been demonstrated. It was observed that turbidity of the brine stream during DO-HS treatment at 3 NTU was 5 times higher than that before DO-HS treatment. The results from this study have confirmed the previous hypothesis with DO-HS treatment that there would be a strong driving force for DO backwash to lift and sweep the foulants from the membrane surface which would be carried over to the brine. The optimal plant operating conditions in terms of RO feed flow rate, HS concentration and HS injection time are ready for the DO-HS method to be adopted and validated in a long-term continuous plant operation.     

Metabolism studies of casticin in rats using HPLC‐ESI‐MSn

Casticin (3′,5‐dihydroxy‐3, 4′,6,7‐tetramethoxyflavone) has been revealed to possess various kinds of pharmacological activities, including immunomodulatory, anti‐hyperprolactinemia, anti‐tumor and neuroprotetective activities. In order to gain an understanding of the biotransformation of casticin in vivo, a systematic method based on liquid chromatography–electrospray ionization tandem mass spectrometry (LC‐ESI‐MSⁿ) was developed to identify the metabolites of casticin in rats after oral administration of single dose of casticin at 200 mg/kg. By comparing their changes in molecular masses (ΔM), retention times and spectral patterns with those of the parent drug, the parent compound and 25 metabolites were identified in rat plasma, urine and six selected tissues. This is the first systematic metabolism study of casticin in vivo. The results indicated that methylation, demethylation, glucuronidation and sulfation were the main biotransformation pathways of casticin in vivo. Copyright © 2012 John Wiley & Sons, Ltd.     

Synthesis of statistical and block copolymers containing adamantyl and norbornyl moieties by reversible addition‐fragmentation chain transfer polymerization

The synthesis of statistical and block copolymers, consisting of monomers often used as resist materials in photolithography, using reversible addition‐fragmentation chain transfer (RAFT) polymerization is reported. Methacrylate and acrylate monomers with norbornyl and adamantyl moieties were polymerized using both dithioester and trithiocarbonate RAFT agents. Block copolymers containing such monomers were made with poly(methyl acrylate) and polystyrene macro‐RAFT agents. In addition to have the ability to control molecular weight, polydispersity, and allow block copolymer formation, the polymers made via RAFT polymerization required end‐group removal to avoid complications during the photolithography. © 2010 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 48: 943–951, 2010     

Uniform sliding states in the undamped Frenkel-Kontorova model

The uniform sliding states of the undamped Frenkel-Kontorova model are reduced to the periodic solutions of an advance-delay differential equation, the existence of which is investigated in this paper by employing variational methods.