Characterization of Zn1?xMgxO Films Prepared by the Sol–Gel Process and Their Application for Thin-Film Transistors

Transparent semiconductor thin films of Zn_1−x Mg _x O (0 ≤ x ≤ 0.36) were prepared using a sol–gel process; the crystallinity levels, microstructures, and optical properties affected by Mg content were studied. The experimental results showed that addition of Mg species in ZnO films markedly decreased the surface roughness and improved transparency in the visible range. A Zn_1−x Mg _x O film with an x-value of 0.2 exhibited the best average transmittance, namely 93.7%, and a root-mean-square (RMS) roughness of 1.63 nm. Therefore, thin-film transistors (TFTs) with a Zn_0.8Mg_0.2O active channel layer were fabricated and found to have n-type enhancement mode. The Zn_0.8Mg_0.2O TFT had a field-effect mobility of 0.1 cm²/V s, threshold voltage of 6.0 V, and drain current on/off ratio of more than 10⁷.     

Tech-ware: Bioinformatics and computational biology resources [Best of the Web]

In this issue, "Best of the Web" presents online resources related to bioinformatics and computational biology. According to Wikipedia, bioinformatics is the application of information technology to the field of molecular biology. It was applied in the creation and maintenance of a database to store biological information such as nucleotide and amino acid sequences. The actual process of analyzing and interpreting data is referred to as another common term, computational biology.     

Dual‐Targeted Photopenetrative Delivery of Multiple Micelles/Hydrophobic Drugs by a Nanopea for Enhanced Tumor Therapy

A photoresponsive pea‐like capsule (nanopea) that also represents a photothermal agent is constructed by wrapping multiple polymer micelles (polyvinyl alcohol, PVA) in reduced graphene oxide nanoshells through a double emulsion approach. Resulting nanopeas can transport multiple PVA micelles containing the fully concealed hydrophobic drug docetaxel (DTX) which can be later released by a near‐infrared photoactuation trigger. Through integrating the rod‐shaped adhesion and lactoferrin (Lf) targeting, the nanopea enhances both uptake by cancer cellc in vitro and particle accumulation at tumor in vivo. A photopenetrative delivery of micelles/DTX to the tumor site is actuated by NIR irradiation which ruptures the nanopeas as well as releases nanosized micelles/DTX. This trigger also results in thermal damage to the tumor and increases the micelles/DTX permeability, facilitating drug penetration into the deep tumor far from blood vessels for thermal chemotherapy. This nanopea with the capability of imaging, enhanced tumor accumulation, NIR‐triggered tumor penetration, and hyperthermia ablation for photothermal chemotherapy boosts tumor treatment and shows potential for use in other biological applications.     

Construction of refractive-index profiles of planar dielectric waveguides from the distribution of effective indexes

From a set of effective indexes, a continuous effective-index function is defined, which is then used to construct a refractive-index profile by numerically solving a WKB equation. The method applies to synthesis of profiles from prescribed propagation constants. Profiles for spatial image transmission are presented as an example. The method can also be applied to recovery of Smooth profiles from measured effective indexes. Effects on the recovery of profiles due to errors in measured effective indexes are demonstrated and procedures are given to alleviate those effects.     

背景谐波阻抗变化情况下的谐波责任划分

在实际电力系统中负荷的投切会改变系统谐波阻抗,现有基于背景谐波阻抗恒定的谐波责任划分方法并不适用。文章定量研究了背景谐波阻抗变化情况下的谐波责任划分,根据背景谐波阻抗变化时谐波电压和谐波电流之间的关系,提出斜率比较法辨识背景谐波阻抗变化的时间点,以此对样本数据进行分段处理,实现数据的自适应分段。在相同段内采用几何平均回归,实现背景谐波阻抗的准确估计,并完成谐波责任的分段划分。同时,定义了背景谐波阻抗变化情况下的总谐波责任指标来更有效地衡量用户的谐波责任大小。在诺顿等效电路中对本文方法进行仿真分析,并与传统方法进行比较,验证了文中方法的有效性和准确性。     

Cream formation in a semifermented tea

The formation of cream in Paochung tea, a popular semifermented tea, which undergoes a lesser degree of enzymic oxidation during manufacture, was investigated at various extraction temperatures, extraction times, pHs and leaf/water ratios. The primary components of Paochung tea cream were catechins (30%), caffeine (20%) and protein (16%). (−)-Epigallocatechin gallate and (−)-epicatechin gallate were the major catechins precipitated during creaming, constituting 19% and 5% of the tea cream respectively. The amount of tea cream produced and its composition were influenced by extraction temperature and pH. The tea leaf/water ratio determined the amount of tea cream formed but did not affect the cream composition. Catechins were considered to be the key component in tea cream. They interacted with caffeine and protein to induce tea cream formation. © 1999 Society of Chemical Industry     

Ethanolic extracts of Antrodia cinnamomea mycelia fermented at varied times and scales have differential effects on hepatoma cells and normal primary hepatocytes

Mycelia of Antrodia cinnamomea (AC), an edible fungus native to Taiwan, were produced by submerged fermentation with various fermentation times in 250 mL, 5 and 500 L fermentors and were evaluated for the effect of fermentation products on the viabilities of Hep3B and HepG2 hepatoma cells and normal primary rat hepatocytes. The results showed that the ethanolic extracts of AC mycelia (from 250 mL fermentation for 8 wk and 5 and 500 L fermentations for 4 wk) possessed high antihepatoma activity. The IC(50) of ethanolic extract of AC mycelia fermented for 8 wk in a 250 mL fermentor against Hep3B and HepG2 cells were 82.9 and 54.2 microg/mL, respectively. Furthermore, the IC(50) for Hep3B and HepG2, treated with ethanolic extract of AC mycelia fermented for 4 wk in the 5 L fermentor were 48.7 and 3.8 microg/mL, respectively. Those treated with ethanolic extract of AC mycelia fermented for 4 wk in the 500 L fermentor were 36.9 and 3.1 microg/mL, respectively. No adverse effects of all samples on normal primary rat hepatocytes were observed.     

Improvement on Physical Properties of Pullulan Films by Novel Cross‐Linking Strategy

Pullulan based films possess several advantages, including high transparency, low toxicity, good biodegradability, good mechanical properties, and low oxygen permeability, are preferable for food packaging. The application of pullulan films on food packaging, however, has inherent disadvantage of high water solubility. In this study, glutaraldehyde and glycerol were used as the cross‐linking reagent and the plasticizer respectively to improve water resistance and physical properties of the pullulan films. Effects of cross‐linking degree on physical properties, including water absorptions, swelling behaviors, water vapor permeability and tensile strengths of films were evaluated. FTIR results demonstrated that the pullulan films were successfully cross‐linked by glutaraldehyde. The tensile strength of pullulan films could be enhanced significantly (P < 0.05) when glutaraldehyde was between 1% and 5% (w/w); nevertheless, the amount of glutaraldehyde above 20% (w/w) led to films brittleness. With the addition of glycerol as a plasticizer enhanced the extensibility of films as well as the hydrophilicity, resulting in higher water vapor permeability.