Anode Magnetron Enhanced DC Glow Discharge Processes for Plasma Surface Cleaning and Polymerization

The objective of this study was to examine some fundamental factors involved in the design and construction of the anode magnetron dc glow discharge processes as well as its performance in plasma cleaning and polymerization. Those advantages of anode magnetron include the capability of the magnetron to operate at low pressure, as well as decreasing the thickness of cathode dark space, i.e., the negative glow which contains a higher concentration of ions and active species was more closely to the cathode surface, which makes the plasma surface cleaning and polymerization an effective and uniform processes. The deposition rate at a given discharge power is increased by the presence of anode magnetrons, and is also much higher relative to rf and af. The refractive index of dc plasma film at a given polymer thickness (such as TMS, 70 nm, RI: 2.4) is higher than rf, af, and cascade arc plasma (RI: 1.6–1.7).     

H2 generation during dry grinding of kaolinite

H2 generation during mechanochemical treatment of kaolinite by dry grinding was examined by X-ray diffraction analysis, Fourier transform infrared spectroscopy, and BET surface area measurement. The H2 concentration in the mill pot, measured by gas chromatography, increased with grinding time up to a maximum concentration of 156 ppm (0.35 micromol) after 600 min. This H2 generation is considered to occur as a result of three processes: (1) structural destruction characterized by the delamination and loss of hydroxyl groups as a result of dry grinding, (2) transformation of liberated hydroxyls into water molecules by mechanochemical effects such as prototropy, and (3) H2 generation through reaction between surface water molecules and mechanoradicals created by the rupture of Si-O or Al-O-Si bonds. Although the surface area plateaued after 240 min grinding, the H2 concentration continued to increase, indicating that surface mechanoradicals are created during this later grinding stage. Thus, H2 generation can be used as an indicator of mechanoradical formation during mechanochemical treatment.     

On a 3-D representation of DNA primary sequences

We introduce a graphical representation of DNA primary sequences by taking four special vectors in a 3-D space to represent the four nucleic acid bases in DNA sequences, so that a DNA primary sequence is denoted in a 3-D space by a successive vector sequence which is a directed walk on the space. It is demonstrated that this representation has no overlap and intersection and allows numerical characterization.     

合成甲醇的催化剂Rh-ZnO/MWNTs的研究

研究新型的由多壁碳纳米管(MWNTs)负载的， ZnO助催的铑基甲醇合成催化剂. 当铑含量达到4％(w)时，催化剂具有较高的比表面积(99.6 m2•g－1), 催化剂的反应活化能为68.8 kJ•mol－1.在563 K, 1 MPa下，催化剂的最高催化活性和甲醇选择性分别为411.4 mg/gcat.•h和96.7％. TEM、TPR和TPD等表征结果显示，碳纳米管能增加Rh在催化剂表面的分散度，提高催化剂的还原温度并能增加氢物种的吸附量，这些结果将有助于更好地了解催化剂中各组分间的协同作用和催化活性中心本质.     

Synthesis of 1,3,4‐Oxadiazoles and 1,3‐Thiazolidinones Containing 1,4,5,6‐Tetrahydro‐6‐pyridazinone

The reaction of 1,4,5,6‐tetrahydro‐6‐pyridazinone‐3‐carboxylic acid hydrazides ( 1 ) with aromatic aldehydes afforded 1,4,5,6‐tetrahydro‐6‐pyridazinone‐3‐carbonyl aromatic aldehyde hydrazones ( 2a‐2g ). Heterocyclic derivatives linked 1,3,4‐oxadiazole obtained by cyclocondensation of 2a‐2g with acetic anhydride in absolute ethanol, and 2a‐2g cyclized with mercaptoacetic acid in DMF in the presence of anhydrous ZnCl₂ afforded the 1,3‐thiazolidinone derivatives. The structures of the new compounds were established by elemental analyses, IR, ¹H NMR and MS spectral data.     

Pharmacokinetic detection of penicillin excreted in urine using a totally internally reflected resonance light scattering technique with cetyltrimethylammonium bromide

A quantitative analysis method for penicillins including ampicillin (AmP), benzyl penicillin (BP), oxacillin (OA) and amoxycillin (AmO) is proposed that makes use of the totally internally reflected resonance light scattering (TIR-RLS) signal from the penicillin at the H₂O/CCl₄ interface in the presence of cetyltrimethylammonium bromide (CTMAB), and enables the pharmacokinetics of penicillin taken orally and excreted through urine to be monitored. Penicillin is coadsorbed with CTMAB at the H₂O/CCl₄ interface in neutral solution, resulting in the formation of ion associates that display greatly enhanced TIR-RLS signals (maximum at 368–372 nm). This enhanced TIR-RLS intensity was found to be proportional to the penicillin concentration over the range 0.2×10^–6 to 2.2×10^–6 mol L^–1, with limits of determination (3) of 5.0×10^–8 to 7.0×10^–8 mol L^–1. Pharmacokinetics studies performed using the present method show that the excretion of orally-taken ampicillin through urine has a half-time of 1.05 h and an excremental quantum over 8 h of 49.3%, respectively.     

Basic peptides as functional components of non-viral gene transfer vehicles

Improving the performance of non-viral gene-delivery vehicles that consist of synthetic compounds and nucleic acids is a key to successful gene therapy. Supplementing synthetic vehicles with various biological functions by using natural or artificial peptides is a promising approach with which to achieve this goal. One of the obstacles hindering this effort is that some of the potentially useful peptides, especially those with many basic amino acid residues, interfere with the formation of the complex owing to strong electrostatic interactions with the nucleic acid. In this review, we describe our recent work in examining the potential of these peptides in gene delivery, using a recombinant lambda phage particle as the model for the gene-delivery complex. Lambda phage encapsulates large duplex DNA in a rigid polyplex-like shell with a diameter of 55 nm, and can display various peptides on this capsid, independently of particle formation. By examining the expression of marker genes encapsulated in the phage capsid, we have demonstrated that the protein transduction domain of HIV Tat protein and the nuclear localization signal derived from SV40 T antigen can remarkably facilitate the delivery of these marker genes across the two major barriers, the cell membrane and the nuclear membrane, respectively. Our results indicate that these basic peptides can constitute effective components of synthetic gene-transfer complexes, as long as sufficient copies are displayed on the outer surface of the complex.     

Quantitative Non-Covalent Functionalization of Carbon Nanotubes

We report a convenient method for quantitative non-covalent functionalization of single-walled carbon nanotubes (SWNT) with phthalocyanine (Pc) compounds, in which a surface coverage of 49% was achieved. The effect of several process parameters on the functionalization process was elucidated. Firstly, as-produced SWNT gave the largest extent of functionalization compared with purified SWNT and as-produced multi-walled carbon nanotubes (MWNT). Secondly, the extent of functionalization was sensitive to the specific molecular structures of the Pc compounds. Finally, in terms of solvent selection, dimethylformamide (DMF) was found to give the largest extent of functionalization, which is then followed by chloroform (CHCl₃) and 1,2-dichlorobenzene (ODCB). The method reported in this paper provides new insights on the interactions between Pc molecules and carbon nanotubes and paves the way for rational control of the degree of functionalization, which is an important step from the perspective of carbon nanotube applications. Electronic supplementary material Supplementary material for this article is avilable at and is accessible for authorised users.     

锌酞菁类染料荧光寿命的非瞬态实验估算

合成了一系列的锌酞菁染料。用循环伏安法测定了它们的氧化还原电位, 并测定了用典型的电子受体猝灭它们的荧光动力学数据。按电子转移模式确定了各染料-电子受体对的荧光猝灭速率常数κ_q对电子从染料向受体转移的自由能变化⊿G函数关系。根据测得的氧化还原电位和光谱数据计算出⊿G, 根据函数关系计算出κ_q, 代入到猝灭动力学数据κ_qτ。这样,就用非瞬态的实验估算出染料的荧光寿命r。与已知的实测文献值进行比较, r的大致范围是可信的。     

Synthesis,structure, and DNA cleavage activity of new trinuclear Zn(3) and Zn(2)Cu complexes of a chiral macrocycle: structural correlation with the active center of P1 nuclease

New homo trinuclear Zn(II) complexes [Zn(3)L(1)(micro-OAc)](ClO(4))(2).3CHCl(3).H(2)O, 1, and [Zn(3)L(1)(micro-OAc)].ClO(4).PF(6).5CH(3)OH.H(2)O, 2, and hetero trinuclear complex [Zn(2)CuL(1)(micro-OAc)](ClO(4))(2).3CHCl(3).H(2)O,3, of optically active hexaaza triphenolic macrocycle H(3)L(1) were synthesized and crystallographically characterized. The cation [Zn(3)L(1)(micro-OAc)](+) structure of 1 and 2 closely resembles the trinuclear Zn(II) active site of P1 nuclease. The distorted tetrahedral geometry of Zn3 was successfully reproduced at Cu1 in complex 3. The complexes 2 and 3 cleave CT DNA at 37 and 50 degrees C.