116例冠心病患者血清中铜铬锰钴镍钒含量的探讨

测定了１１６例冠心病患者血清中铜、铬、锰、钴、镍、钒的含量并与正常值比较，显示含量升高才是有铬和镍，降低者有钴和钒、无差异者有铜和锰。     

Electrochemical study of bergenin on a poly(4-(2-pyridylazo)-resorcinol) modified glassy carbon electrode and its determination in tablets and urine

A very sensitive electroanalytical method was employed to determine bergenin in phosphate buffer with a pH of 6.0, bergenin was accumulated at a 4-(2-pyridylazo)-resorcinol (PAR) polymer film modified glassy carbon electrode (GCE) surface under the condition of open-circuit. In the following anodic sweep from −0.4 to 0.8 V, bergenin adsorbed at the PAR polymer film modified electrode surface, was oxidized and yielded a sensitive oxidation peak at 0.595 V. Due to its unique structure and extraordinary properties, the PAR polymer film shows higher accumulation efficiency toward bergenin compared with a bare GCE. Hence, the amount of bergenin at the PAR polymer film modified GCE surface increases significantly, and finally the oxidation peak current improves greatly. The experimental conditions, such as supporting electrolyte, pH value, accumulation time and scan rate, were optimized for the measurement of bergenin, and a sensitive electroanalytical method was proposed for bergenin determination. The oxidation peak current varies linearly with the concentration of bergenin over the range of 2.0 × 10⁻⁷ to 1.2 × 10⁻⁵ mol/L, and the detection limit is 2.0 × 10⁻⁸ mol/L after 3 min open-circuit accumulation. The relative standard deviation of the same electrode in 10 successive scans is 1.8% for 1.0 × 10⁻⁶ mol/L bergenin and 2.1% for interelectrodes, indicating excellent reproducibility. This new method was successfully demonstrated with bergenin tablets and diluted urine.     

Double anionic cycloaromatization of 2-(6-substituted-3-hexene-1,5-diynyl)benzonitriles initiated by methoxide addition

[reaction: see text] Treatment of 2-((3Z)-undecene-1,5-diynyl)benzonitrile with 5 equiv of sodium methoxide in refluxing methanol for 16 h gave 1-pentyl-6-methoxyphenanthridine in 12% yield, 1-pentyl-6-phenanthridone in 6% yield, and 2-(2-pentyl-6-methoxyphenyl)benzonitrile in 4% yield. Under the same reaction conditions, methanolysis of several other benzonitriles gave similar results. Phenanthridine and biphenyl derivatives were obtained as the major products. A mechanism for this novel cycloaromatization reaction of enediynes is proposed.     

A hierarchical assembly strategy for near-infrared photothermal conversion: unconventional heterogeneous metalla[2]catenanes

Herein, we report a hierarchical assembly strategy for constructing heterogeneous half-sandwich organometallic D–A (D = π-donor, A = π-acceptor) interlocked structures, and their application in near-infrared (NIR) photothermal conversion. Thienothiophene and diketopyrrolopyrrole groups were selected as the D and A units, leading to two homogeneous metalla[2]catenanes with D–D–D–D and A–A–A–A stacks, respectively. By the ordered secondary assembly of homogeneous metalla[2]catenanes, two unprecedented heterogeneous D–A metalla[2]catenanes comprising an unusual mixed D–A–D–D and unconventional D–A–A–A stacks were realized by the combination of multiple noncovalent interactions, as all demonstrated by a detailed X-ray crystallographic study. Benefiting from the mixed D–A stacking modes, NIR absorption of heterogeneous D–A metalla[2]catenanes is significantly enhanced in contrast to homogeneous metalla[2]catenanes. Thanks to the enhanced NIR absorption and the fluorescence quenching effect from half-sandwich organometallic fragments, heterogeneous D–A metalla[2]catenanes displayed high-performance NIR photothermal conversion properties (η = 27.3%).

Herein, we report a hierarchical assembly strategy for constructing heterogeneous half-sandwich organometallic D–A (D = π-donor, A = π-acceptor) interlocked structures, and their application in near-infrared (NIR) photothermal conversion.     

High-resolution DNA separation in microcapillary electrophoresis chips utilizing double-L injection techniques

An experimental and numerical investigation into the use of high-resolution injection techniques to separate DNA fragments within electrophoresis microchips is presented. The principal material transport mechanisms of electrokinetic migration, fluid flow, and diffusion are considered, and several variable-volume injection methods are discussed. A detailed analysis is provided of a double-L injection technique, which employs appropriate electrokinetic manipulations to reduce sample leakage within the microchip. The leakage effect in electroosmotic flow (EOF) is investigated using a sample composed of rhodamine B and Cy3 dye. Meanwhile, the effects of sample leakage in capillary electrophoresis (CE) separation are studied by considering the separation of 100-base pairs (bp) DNA ladders and HaeIII-digested PhiX-174 DNA samples. The present experimental and simulation results indicate that the unique injection system employed in the current microfluidic chip has the ability to replicate the functions of both the conventional cross-channel and the shift-channel injection systems. Furthermore, applying the double-L injection method to these two injection systems is shown to reduce sample leakage significantly. The proposed microfluidic chip and double-L injection technique developed in this study have an exciting potential for use in high-resolution, high-throughput biochemical analysis applications and in many other applications throughout the micrototal analysis systems field.     

Surface-enhanced Raman scattering in the ultraviolet spectral region: UV-SERS on rhodium and ruthenium electrodes

We report the first observation of surface-enhanced Raman scattering (SERS) excited with ultraviolet (UV) light from transition metal electrodes. Adsorbed pyridine and SCN- on rough rhodium (Rh) and ruthenium (Ru) electrodes, respectively, have been studied using 325 nm laser excitation. In contrast, the best enhancers in the visible and near infrared, silver and gold, do not produce UV-SERS. The experimental data of UV-SERS are in agreement with our preliminary theoretical calculation based on the electromagnetic enhancement mechanism. The enhancement factor is about 2 orders of magnitude for the Rh and Ru electrodes when they are excited at 325 nm.     

Measurement of toxic volatile organic compounds in indoor air of semiconductor foundries using multisorbent adsorption/thermal desorption coupled with gas chromatography-mass spectrometry

A method for the qualitative and quantitative analysis of volatile organic compounds (VOCs) in the air of class-100 clean rooms at semiconductor fabrication facilities was developed. Air samples from two semiconductor factories were collected each hour on multisorbent tubes (including Carbopack B, Carbopack C, and Carbosieve SIII) with a 24-h automatic active sampling system and analyzed using adsorption/thermal desorption coupled with gas chromatography-mass spectrometry. Experimental parameters, including thermal desorption temperature, desorption time, and cryofocusing temperature, were optimized. The average recoveries and the method detection limits for the target compounds were in the range 94-101% and 0.31-0.89 ppb, respectively, under the conditions of a 1 L sampling volume and 80% relative humidity. VOCs such as acetone, isopropyl alcohol, 2-heptanone, and toluene, which are commonly used in the semiconductor and electronics industries, were detected and accurately quantified with the established method. Temporal variations of the analyte concentrations observed were attributed to the improper use of organic solvents during operation.     

On-line concentration of s-triazine herbicides in micellar electrokinetic chromatography using a cationic surfactant

A new method for the simultaneous determination of anions (sulfate, nitrate, and chloride) and cations (sodium, ammonium, potassium, magnesium, and calcium) in acid rain waters was investigated using high-performance ion-exclusion/cation-exchange chromatography with conductimetric detection on a separation column packed with a polymethacrylate-based weakly acidic cation-exchange resin in the hydrogen-form and an eluent comprising 1.5 mM sulfosalicylic acid–6 mM 18-crown-6 at pH 2.6, operated at 1.5 ml/min. Effective separation and highly sensitive conductimetric detection for the anions and the cations was achieved in about 14 min. Since the ionic balance (equivalents of anions/equivalents of cations) of acid rain waters of different pH (4.40–4.67) ranged from 0.97 to 0.94, evaluation of the water quality of acid rain was possible. This method was successfully applied to the simultaneous determination of the anions and the cations in acid rain transported from mainland China and North Korea to central Japan monitored by a meteorological satellite data analyzer.     

New synthesis of 2,4-dialkyl(or diaryl)pyrazolo[1,5-a]-1,3,5-triazines

Reactions of monothiodiacylamines or N-aroylthioimidates with 3-aminopyrazoles gave pyrazolo[1,5-a]-1,3,5-triazines in good yields.     

On the surface modification of microchannels for microcapillary electrophoresis chips

This paper presents systematic investigation of the microchannel surface properties in microCE chips. Three popular materials for microCE chips, polydimethylsiloxane (PDMS), quartz, and glass, are used. The zeta potentials of these microchannels are calculated by measuring the EOF velocity to evaluate the surface properties after surface modification. The hydrophobic PDMS is usually plasma-treated for microCE applications. In this study, a new method using a high-throughput atmospheric plasma generator is adopted to treat the PDMS surface under atmospheric conditions. In this approach, the cost and time for surface treatment can be significantly reduced compared with the conventional vacuum plasma generator method. Experimental results indicate that new functional groups could be formed on the PDMS surface after treatment, resulting in a change in the surface property. The time-dependent surface property of the plasma-treated PDMS is then measured in terms of the zeta potential. Results show that the surface property will reach a stable condition after 1 h of plasma treatment. For glass CE chips, two new methods for changing the microchannel surface properties are developed. Instead of using complicated and time-consuming chemical silanization procedures for CE channel surface modification, two simple and reliable methods utilizing organic-based spin-on-glass and water-soluble acrylic resin are reported. The proposed method provides a fast batch process for controlling the surface properties of glass-based CE channels. The proposed methods are evaluated using PhiX-174 DNA maker separation. The experimental data show that the surface property is modified and separation efficiency greatly improved. In addition, the long-term stability of both coatings is verified in this study. The methods proposed in this study show potential as an excellent solution for glass-based microCE chip surface modification.