Efficient Bromination of Alkenes and Alkynes Using Potassium Bromide and Diacetoxy Iodobenzene

Bromination of alkenes and alkynes has efficiently been carried out at room temperature in short reaction times using KBr and diacetoxy iodobenzene in CH₂Cl₂-H₂O (1:1) to prepare the corresponding trans-dibromo compounds in excellent yields.     

数字图像处理中位图读取和基本操作

从位图结构角度实现位图的读取和旋转的基本操作， 而不需要应用API函数。这样不仅能够撇开API函数的中间层，而且能够对位图文件有一个更进一步的理解，这对简化图像处理工作大有帮助。     

A simple and sensitive HPLC-fluorescence method for quantification of MDMA and MDA in blood with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) as a label

A sensitive high-performance liquid chromatographic method with fluorescence detection to determine 3,4-methylenedioxymethamphethamine (MDMA) and 3,4-methylenedioxyamphethamine (MDA) in human and rat whole blood or plasma samples was developed by using 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) as a label. MDMA and MDA in a small amount of blood sample (ca 100 microL) were extracted by liquid-liquid extraction with ethyl acetate, and were derivatized with DIB-Cl under mild conditions (10 min at room temperature). A good separation of DIB-derivatives could be achieved within 45 min using a commercially available ODS column with an isocratic eluent of 10 mM citric acid-20 mM Na(2)HPO(4) aqueous buffer (pH 4.0)-CH(3)CN-CH(3)OH (50:45:5, v/v/v %). The calibration curves prepared with 1-methyl-3-phenylpropylamine (MPPA) as an internal standard showed good linearity (r = 0.999) with 0.36-0.83 ng/mL detection limit at a signal-to-noise ratio of 3. MDMA and MDA in rat whole blood could be monitored for 6 h after a single administration of MDMA (2.2 mg/kg, i.p.). The pharmacokinetic parameters for MDMA and MDA obtained by triplicate measurements were 426 +/- 23 and 39 +/- 6 ng/mL (C(max)), 20 +/- 5 and 100 +/- 10 min (T(max)), respectively.     

Digital image-based titrations

The exploitation of digital images obtained from a CCD camera (WebCam) as a novel instrumental detection technique for titration is proposed for the first time. Named of digital image-based (DIB) titration, it also requires, as a traditional titration (for example, spectrophotometric, potentiometric, conductimetric), a discontinuity in titration curves where there is an end point, which is associated to the chemical equivalence condition. The monitored signal in the DIB titration is a RGB-based value that is calculated, for each digital image, by using a proposed procedure based on the red, green, and blue colour system. The DIB titration was applied to determine HCl and H₃PO₄ in aqueous solutions and total alkalinity in mineral and tap waters. Its results were compared to the spectrophotometric (SPEC) titration and, by applying the paired t-test, no statistic difference between the results of both methods was verified at the 95% confidence level. Identical standard deviations were obtained by both titrations in the determinations of HCl and H₃PO₄, with a slightly better precision for DIB titration in the determinations of total alkalinity. The DIB titration shows to be an efficient and promising tool for quantitative chemical analysis and, as it employs an inexpensive device (WebCam) as analytical detector, it offers an economically viable alternative to titrations that need instrumental detection.     

Tracer transport in a fractured chalk: X-ray CT characterization and digital-image-based (DIB) simulation

A digital-image-based simulation methodology is applied to evaluate the influence of heterogeneous porosity on the evolution of tracer concentrations in imaged tracer tests. Maps of computed tomography (CT)-number are calibrated relative to average porosity, and then thresholded to define porosity maps. These data are then used to automate the distribution of parameters within a finite element representation of the geometry. The technique is applied to characterize the variability of the porosity, the hydraulic conductivity, and the diffusivity for an artificially fractured chalk core (30 × 5 cm). X-ray CT was used both to characterize the initial condition of the core, and then to concurrently monitor the transport of an NaI tracer within the fracture and into the surrounding matrix. The X-ray CT imaging is used to characterize the heterogeneous rock porosity, based on which the hydraulic conductivity, and diffusivity of the chalk were defined and were directly imported into our newly developed three-dimensional FEMLAB-based multiple physics simulator. Numerical simulations have confirmed the observed tracer transport behaviors: (1) The different tracer-penetration distances imaged in the matrix above and below the horizontal fracture are indicative of a greater tracer mass penetrating into the lower matrix; and (2) Transport in the matrix below the fracture was enhanced. The computer simulated tracer concentration distributions compare favorably with those monitored by X-ray CT.     

Determination of memantine in rat plasma by HPLC-fluorescence method and its application to study of the pharmacokinetic interaction between memantine and methazolamide

A sensitive high-performance liquid chromatographic method with fluorescence detection was developed to determine memantine (MT) in rat plasma. The method consists of pre-column labeling of MT with 4-(4,5-diphenyl-1H-imidazol-2-yl)benzoyl chloride (DIB-Cl) and a clean-up step with solid-phase extraction. A good separation of DIB-MT was achieved within 12 min on an octadecylsilica (ODS) column (150 × 4.6 mm i.d.; 5 μm) with a mobile phase of acetonitrile-water (70:30, v/v). The calibration curve prepared with fluoxetine as an internal standard showed good linearity in the range of 10-400 ng/mL (r = .999). The limits of detection and quantitation at signal-to-noise ratios of 3 and 10 were 2.0 and 6.6 ng/mL, respectively. The method was shown to be reliable with precisions of <5% for intra-day and <9% for inter-day as relative standard deviation. The fluorescence property and reaction yield of authentic DIB-MT were also examined. The proposed method was successfully applied to study the pharmacokinetic interaction between MT and methazolamide.     

Simultaneous determination of N-benzylpiperazine and 1-(3-trifluoromethylphenyl)piperazine in rat plasma by HPLC-fluorescence detection and its application to monitoring of these drugs

An HPLC‐fluorescence detection method for simultaneous determination of N‐benzylpiperazine (BZP) and 1‐(3‐trifluoromethylphenyl)piperazine (TFMPP) labeled with 4‐(4,5‐diphenyl‐1 H‐imidazol‐2‐yl)benzoyl chloride (DIB‐Cl) was described. DIB‐BZP and ‐TFMPP were well separated within 13 min without interference of peaks from plasma components. The lower detection limits of BZP and TFMPP at a signal‐to‐noise ratio of 3 were 0.9 and 4.6 ng/mL, respectively. Precisions of the proposed method for intra‐ and inter‐day assays were less than 4.8 and 9.1% as %RSD (n = 5). Furthermore, the method could be successfully applied to monitor both compounds in plasma after their sole or co‐administration to rats (each dose, 2 mg/kg). Clearance of TFMPP was significantly different under the conditions (P = 0.047). Copyright © 2011 John Wiley & Sons, Ltd.     

端基炔烃的简单快速二聚反应

端基炔烃在无钯催化剂的条件下, 以乙腈为溶剂, 三乙胺为碱, 与氯化亚铜和二醋酸碘苯反应, 常温下短时间内得到高产率的二聚产物, 提供了一个简单快速合成共轭二炔烃的新方法. 比较了反应条件, 并提出了可能的反应机理.     

Borland C++ Builder 下DIB 的生成及其应用

讨论了Ｃ＋＋Ｂｕｉｌｄｅｒ环境下使用ＶＣＬ组件和用Ｗｉｎ３２ＡＰＩ函数直接生成ＤＩＢ的方法及其在图像处理低层操作中的应用。