Opal Gels Templated Synthesis of Structured Titania Materials

Summary: Core/shell opal gels of sulfonated polystyrene were used as templates to synthesize structured crystalline titania materials. Under acidic conditions, opal materials with hollow spheres of controllable shell thickness and cavity size were prepared. Under neutral conditions, inverse opal inorganic materials with a tunable pore size were prepared. It is crucial that proton ions induce a preferential sol/gel process, forming titania in the gel.

Scanning electron micrograph of the interior region of a structured titania material derived from the G1 template used here. The inset shows broken spheres in which the internal cavity can be observed.     

A General Approach toward Opal–Inverse Opal Interlocked Materials

Opal–inverse opal interlocked composites consisting of opals of hollow spheres with window channels interlocked, have displayed new properties. A facile and general method has been reported to synthesize the ordered composites. Polymer shells are first grown onto the surface of a silica sphere of an opal template by ATRP, which is followed by a sequential modification of the shells resulting in functional groups. Composite shells are favorably synthesized within the functional polymer shells. After the removal of silica opal templates, opal–inverse opal interlocked structures with varied compositions of polymers, inorganic materials, and carbon are achieved.

     

断裂分析中的随机有限元方法

以单边裂纹板为例给出计算断裂参数:J(J积分)、δ(裂纹张开位移)、Δc(由裂纹引起的上、下端面的相对位移)、θc(由裂纹引起的上、下端面的相对转角)及其对基本随机变量变化率的随机有限元方法.     

UPLC–MS/MS simultaneous determination of seven active ingredients of Yaobitong capsule in rat plasma and its integrated pharmacokinetic application

A reliable and sensitive UPLC–MS/MS method was first established and validated for the simultaneous determination of seven active ingredients of Yaobitong capsule in rat plasma: ginsenoside Rg1, ginsenoside Rb1, osthole, tetrahydropalmatine, paeoniflorin, albiflorin, and ferulic acid. And this method was further applied for the integrated pharmacokinetic study of Yaobitong capsule in rats after oral administration. Plasma samples (100 μL) were precipitated with 300 μL of methanol using carbamazepine as internal standard. Chromatographic separation was achieved using an Aquity UPLC BEH C18 column (100 × 2.1 mm, 1.7 μm), with the mobile phase consisting of 0.1% formic acid and acetonitrile. The method was validated using a good linear relationship (r ≥ 0.991), and the lower limit of quantification of the analytes ranged from 0.5 to 40 ng/mL. In the integrated pharmacokinetic study, the weight coefficient was calculated by the ratio of AUC_0–∞ of each component to the total AUC_0–∞ of the seven active ingredients. The integrated pharmacokinetic parameters C_max, T_max, and t_1/2 were 81.54 ± 9.62 ng/mL, 1.00 ± 0.21 h, and 3.26 ± 1.14 h, respectively. The integration of pharmacokinetic parameters showed a shorter t_1/2 because of fully considering the contribution of the characteristics of each active ingredient to the overall pharmacokinetics.     

Simultaneous determination of seven main alkaloids of Chelidonium majus L. by ultra‐performance LC with photodiode‐array detection

A simple and rapid method for the simultaneous determination of seven isoquinoline alkaloids, protopine, chelidonine, coptisine, stylopine, sanguinarine, berberine, and chelerythrine, in Chelidonium majus L. (Ch. majus) samples by ultra‐performance LC method with photodiode array detection is described. The baseline separation of these compounds was performed with (A) acetonitrile–(B) ammonium acetate (10 mM, adjusted to pH 3.0 with acetic acid) as the mobile phase using a C18 RP column (2.1×100 mm, 1.7 μm). Optimized conditions resulted in excellent peak shapes. The seven alkaloids were completely separated within 20 min. Good linear behaviors (r≥0.9992) over the investigated concentration ranges were observed for all the analytes. Validation proved the repeatability of the method was good and recovery was satisfactory. The validated method was successfully applied for 20 batches of Ch. majus. These results demonstrated that the ultra‐performance LC photodiode array method proposed was very useful in the analysis and quality control of Ch. majus.     

Amphiphilic Patchy Composite Colloids

A new approach to fabricate patchy silica/polymeric gel composite colloids with amphiphilic performance is reported. The amphiphilic performance is rendered by selectively modifying the silica framework with a silane that contains an oleophilic alkyl chain. The patchy composite colloids are dispersible in both water and oil, and may be used as a solid particle surfactant. The modified silica framework can also assist other functional materials to disperse in a desired media. The corresponding silica/carbon composite colloids become amphiphilic after a sequential activation of carbon and modification of silica, and meanwhile possess as good electron conductivity as the as‐prepared silica/carbon composite colloids.

     

Simultaneous determination of neochlorogenic acid,chlorogenic acid,cryptochlorogenic acid and geniposide in rat plasma by UPLC‐MS/MS and its application to a pharmacokinetic study after administration of Reduning injection

A simple, specific and sensitive ultra‐performance liquid chromatography tandem mass spectrometry (UPLC‐MS/MS) method was established and validated for simultaneous determination of neochlorogenic acid, chlorogenic acid, cryptochlorogenic acid and geniposide in rat plasma using puerarin as an internal standard (IS). Plasma samples were pretreated by a one‐step direct protein precipitation procedure with acetonitrile after acidified using as little as 50 μL plasma. Chromatographic separation was performed on an Acquity BEH C₁₈ column (100 × 2.1 mm, 1.7 µm) at a flow rate of 0.2 mL/min by a gradient elution, using 0.2% acetic acid–methanol as mobile phase. The detection was performed on a triple quadrupole tandem mass spectrometer by multiple reaction monitoring via electrospray ionization source with negative ion mode. Calibration curves showed good linearity (r > 0.995) over wide concentration ranges. The intra‐ and inter‐day precisions were <15%, and the accuracy was within ±8.0%. The validated method was successfully applied to a pharmacokinetic study of the four bioactive components in rats after intravenous administration of Reduning injection. Copyright © 2014 John Wiley & Sons, Ltd.     

Janus Composite Nanotubes

We propose a facile method to achieve paramagnetic Janus nanotubes with two compositions compartmentalized onto the interior and exterior surfaces, respectively. A sulfonated polydivinylbenzene (PDVB) nanotube is prepared by simple sulfonation of the exterior surface of a PDVB nanotube. Silica@FeOOH dual layers are sequentially grown onto the sulfonated PDVB nanotube surface. The composite nanotubes become paramagnetic after calcination and can be broken into shorter pieces under vigorous ultrasonication. After selective modification of the interior and exterior surfaces of the paramagnetic nanotubes, the nanotube shell becomes Janus in wettability. Desired hydrophobic species can be selectively captured inside the cavity. The paramagnetic Janus composite nanotubes can align into parallel chains under a magnetic field, which is self‐disassembled upon removal of the magnetic field.