荧光免疫层析试条光电信号处理及特征量选取

荧光免疫层析定量检测技术是一种正在兴起的即时检验技术。在前期荧光免疫层析定量检测仪的研究基础上,采用小波算法对A/D采样后的荧光信号进行去噪处理,选用中值滤波剔除基线漂移,最后比较了采用测试线峰值和面积作为特征量的定量检测效果。数据显示,去噪后信噪比提高10 d B,相对均方差减小30.4%;采用峰值和面积值作为定量特征量的测量CV值分别为5.1%和0.4%,测量误差分别为9.1%和0.9%。结果表明采用积分面积作为特征量对荧光信号进行定量检测具有更好的准确度和重复性。     

The flame‐retardant properties and mechanisms of poly(ethylene terephthalate)/hexakis (para‐allyloxyphenoxy) cyclotriphosphazene systems

Para‐allyl ether phenol derivative of cyclophosphazene (PACP) was prepared and used as a filler to modify the flame‐retardant properties of poly(ethylene terephthalate) (PET) by melting‐blending. The mechanism of flame‐retardant was discussed and the influences of flame‐retardant contents to the mechanical properties were studied. The results revealed that the incorporation of only 5 phpp PACP (0.37 wt % phosphorus containing) into PET matrix can distinctly increase the flame retardancy of PET/PACP composition, and it has a little effect on the mechanical properties of PET. The high flame‐retardant performance of PET/PACP composite was attributed to the combination of condensed‐phase flame retardant and gas‐phase flame retardant. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42711.     

Preparation and characterization of methoxy‐poly(ethylene glycol) side chain grafted onto chitosan as a wound dressing film

Chitosan has received extensive attention as a biomedical material; however, the poor solubility of chitosan is the major limiting factor in its utilization. In this study, chitosan‐based biomaterials with improved aqueous solubility were synthesized. Two molecular weights (750 Da and 2000 Da) of methoxypoly(ethylene glycol) (mPEG) were grafted onto chitosan (mPEG‐g‐chitosan) to form a ～100‐μm‐thick plastic film as a wound dressing. The chemical structures of the mPEG‐g‐chitosan copolymers were confirmed using Fourier transform infrared spectroscopy (FTIR), and the thermal properties were characterized using thermogravimetry analysis (TGA). Their microstructures were observed using scanning electron microscopy (SEM). The other properties were analyzed via the swelling ratio, tensile strength, elongation, and water vapor transmission rate (WVTR). Biocompatibility evaluations through biodegradability, cytotoxicity, and antimicrobial effect studies were also performed. The obtained mPEG‐g‐chitosan copolymers were soluble in slightly acidic aqueous solutions (pH～6.5) at a concentration of 10 wt %. The optimal mPEG‐g‐chitosan hydrogels had swelling ratios greater than 100% and WVTRs greater than 2000 g/m²/day. Their performance against Staphylococcus aureus will be subjected to further improvements with respect to medical applications. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42340.     

In vitro and in vivo evaluations of a novel pulsed and controlled osmotic pump capsule

Objective: For better treatment of circadian cardiovascular events, a novel Propranolol hydrochloride (PNH) delayed-release osmotic pump capsule was developed.

Methods: The capsule body was designed of asymmetric membrane and the capsule cap was made impermeable. The physical characteristics of capsule body walls and membrane permeability were compared among different coating solutions.

Results: The formulation with the glycerin and diethyl phthalate (DEP) ratio of 5:4 appeared to be the best. The lag time and subsequent drug release were investigated through assembling the capsule body with capsule caps of different length. WSR N-10 was chosen as the suspending for its moderate expanding capacity. The influence of factors (WSR N-10 content, NaCl content and capsule cap length) on the responses (lag time and drug release rate) was evaluated using central composite design-response surface methodology. A second-order polynomial equation was fitted to the data and actual response values were in good accordance with the predicted ones. The optimized formulation displayed complete drug delivery, zero-order release rate with 4-h lag time. The results of in vivo pharmacokinetics in beagle dogs clearly suggested the controlled and sustained release of PNH from the system and that the relative bioavailability of this preparation was about 1.023 comparing the marketed preparation.

Conclusions: These results indicate that by the adjustment of capsule cap length, PNH could be developed as a novel pulsatile and controlled drug delivery system.     

Potentials of proniosomes for improving the oral bioavailability of poorly water-soluble drugs

Objective: The objectives of this study were, first, to develop a free-flowing and stable proniosome formulation for poorly water-soluble drugs such as vinpocetine; and second, to estimate its bioavailability as oral drug delivery system.

Methods: The proniosomes consisting of span60, cholesterol, sorbitol and vinpocetine were prepared by a novel approach. After the proniosomes were contacted with water, the suspension of vinpocetine-loaded niosomes formed automatically. The proniosomes and reconstituted niosomes were evaluated for their physicochemical characteristics, in vitro drug dissolution and release, integrity and stability at different GI tract pH conditions, in situ single-pass intestinal perfusion and in vivo bioavailability.

Results: The proniosome powder exhibited excellent flowability. The reconstituted niosomes with high drug entrapment efficiency (89.67?±?3.28%) showed spherical morphology with smooth surface under transmission electron microscope (TEM). X-ray diffraction (XRD) indicated that the drug was in an amorphous or molecular state in proniosome powder. In vitro dissolution and release study, proniosomes did enhance the dissolution and release rate compared to vinpocetine suspension in phosphate buffer solution (pH 7.2). Proniosome-derived niosomes could keep their integrity and stability at different GI tract pH conditions. The in situ single-pass intestinal perfusion indicated that encapsulation of vinpocetine into niosomes could largely improved the absorption of vinpocetine. The AUC(0?∞) of F2 and F3 was about 4.0- and 4.9-fold higher than that of the vinpocetine suspension, respectively. The results demonstrated the proniosomes indeed remarkably enhanced the oral bioavailability of vinpocetine.

Conclusion: This study suggested the potential of proniosomes as stable precursors for the immediate preparation of niosome carrier systems.     

Developing New Multivariate Process Capability Indices for Autocorrelated Data

Traditionally, the process capability index is developed assuming that the process output data are independent and follow normal distribution. However, in most environmental cases, the process data have more than one quality characteristic and exhibit property of autocorrelation. We propose two novel multivariate process capability indices for autocorrelated data, NMAC_p and NMAC_pm, for the nominal‐the‐best case. For the smaller‐the‐better case, Γ(0) is used to modify the ND index and a new multivariate autocorrelated process capability index NMAC_pu is derived. Furthermore, a simulation study is conducted to compare the performance of the various multivariate autocorrelated indices. The simulation results show that the actual nonconforming rates can be correctly reflected by our proposed indices, which outperform the previous C_p^m, MC_p, MC_pm, NMC_p, NMC_pm, and ND indices under different time series models. Thus, our proposed capability indices can be used in evaluating the performance of multivariate autocorrelated processes. Finally, a realistic example in hydrological application further demonstrates the usefulness of our proposed capability indices. Copyright © 2013 John Wiley & Sons, Ltd.