Rapid screening of tetrodotoxin in urine and plasma of patients with puffer fish poisoning by HPLC with creatinine correction

A rapid and simple detection method for tetrodotoxin (TTX) in urine and plasma of patients with puffer fish poisoning was developed using commercially pre-packed solid-phase extraction (SPE) cartridges (C18 and weak cation exchange columns) and subsequent analyses by HPLC with UV detection. The detection limit of the standard TTX, TTX-spiked urine and plasma samples were all 10 ng/ml and the average TTX recovery in urine and plasma samples after SPE were 90.3 ± 4.0 and 87.1 ± 2.9%, respectively. It was noticed that the creatinine-adjusted urinary TTX levels obtained within the first 24 h of presentation apparently correlated much better with the severity of poisoning than the urinary TTX concentration without adjusting for variations in concomitant creatinine excretion.     

Content composition and antioxidant activity of isoflavones in commercial and homemade soymilk and tofu

BACKGROUND: Isoflavones, found in soymilk and tofu, are one of the phytochemicals in soy‐based products that may promote good health. Homemade tofu and various homemade soymilk samples were made using different soaking, grinding, and cooking methods. The homemade samples were compared to commercial tofu and soymilk for total isoflavone content and composition as well as their antioxidant capacity. All samples were freeze‐dried and extracted with a 58% acetonitrile solution which was subsequently used to determine the isoflavone content by reverse‐phase high‐performance liquid chromatography. The antioxidant activity of extracts was determined using a modified 2,2‐azino‐bis‐(3‐ethylbenzthiazoline‐6‐sulfonic acid) method and total antioxidant capacity was reported as ascorbic acid equivalents. RESULTS: The total isoflavone, aglycone, and antioxidant levels were significantly higher in homemade soymilk and tofu (1571 µg) than in commercial samples. Homemade soymilk made by the extended boiling method yielded the highest total isoflavone (2567 µg) and glucoside (1525 µg) content. A strong positive correlation was observed between the total isoflavone, aglycone conjugates, and genistein series concentration and antioxidant capacity of soymilk. CONCLUSION: Increased moist heating time yielded the highest concentration of total isoflavones as well as aglycone conjugates and the genistein series. Increasing the duration of boiling can increase the isoflavone content of both homemade and commercial soymilk and tofu. Copyright © 2007 Society of Chemical Industry     

Anti yeast activities of some essential oils in growth medium, fruit juices and milk

The anti-yeast activities of four essential oils (EOs) from clary sage, juniper, lemon and marjoram against wild-type isolates of the food-related yeasts Geotrichum candidum, Pichia anomala, Saccharomyces cerevisiae and Schizosaccharomyces pombe in malt extract (ME) medium, apple juice and milk were investigated. Minimal inhibitory concentrations (MICs) for the EOs and their main components were determined and the checkerboard method was used to calculate fractional inhibitory concentration (FIC) indices for the combinations of EOs or components. The most sensitive yeast was S. pombe (MICs of 0.0625-0.125 μl/ml) while G. candidum proved to be the most insensitive (MICs of 0.5-2 μl/ml). In general, the lag phases were lengthened by increasing EO concentrations, while significant reduction of growth rates was obtained only at the highest EO concentrations. The anti-yeast effects of the EOs were good in the acidic pH range optimal for yeasts growth. Combinations of juniper and clary sage EOs resulted in additive effects in the case of S. cerevisiae and G. candidum, but all other combinations showed no interaction. The combination of α-pinene and limonene led to synergism, while the combination of α-pinene with linalool resulted in an additive effect. Cloudy apple juice protected the yeasts against the effect of lemon EO: the lag phases were shorter and the growth rates higher than in clear apple juice. Lemon EO decreased the growth rate of G. candidum in skimmed milk in a dose-independent manner. Our results show that by adding lemon EO to clear apple juice a new, harmonic taste can be achieved and open storage time could be prolonged.     

A microfabricated nickel–hydrogen battery using thick film printing techniques

To utilize the distinctive cycle life and safety characteristics of the nickel–hydrogen chemistry while eliminating the high pressure limitations of conventional nickel–hydrogen cells, a microfabricated nickel–hydrogen battery using a low-pressure metal hydride for hydrogen storage is being developed for powering micro-electromechanical systems (MEMS) devices and for biomedical applications where the battery would be implanted within the body. Thick film printing techniques which are simple and low cost were used to fabricate this battery. Inks were developed for each of the different battery components, including the electrodes, current collectors and separator. SEM images on these printed components showed the desired characteristics for each. Positive electrode cycling tests were performed on the printed positive electrodes while cyclic voltammetry was used to characterize the printed negative electrodes. Consistent charge and discharge performance was observed during positive electrode cycling. Full cells with printed positive and negative assemblies were assembled and tested.     

Mechanism analysis of the post-buckling response of a circular ring under external pressure

A simple rigid plastic mechanism analysis, incorporating strain-hardening effects, is presented for the analysis of the plastic post-buckling response of a circular ring under external pressure. Results are found to compare favourably with those obtained through more elaborate studies.     

Versatile sensing devices for self-driven designated therapy based on robust breathable composite films

Flexible wearable electronics were developed for applications such as electronic skins,human-machine interactions,healthcare monitoring,and anti-infection therapy.But conventional materials showed impermeability,single sensing ability,and no designated therapy,which hindered their applications.Thus it was still a great challenge to develop electronic devices with multifunctional sensing properties and self-driven anti-infection therapy.Herein,flexible and breathable on-skin electronic devices for multifunctional fabric based sensing and self-driven designated anti-infection therapy were prepared successfully with cellulose nanocrystals/iron(Ⅲ)ion/polyvinyl alcohol(CNC/Fe³⁺/PVA)composite.The resultant composite films possessed robust mechanical performances,outstanding conductivity,and distinguished breathability(3.03 kg/(m²·d)),which benefited from the multiple interactions of weak hydrogen bonds and Fe³⁺ chelation and synergistic effects among CNC,polyaniline(PANI),and PVA.Surprisingly,the film could be assembled as a multifunctional sensor to actively monitor real-time physical and infection related signals such as temperature,moisture,pH,NH3,and human movements even at sweat states.More importantly,this multifunctional device could act as a self-driven therapist to eliminate bacterial by the release of Fe³⁺,which was driven by the damage of metal coordination Fe-O bonds due to the high temperature caused by infection at wound sites.Thus,the composite films had potential versatile applications in electronic skins,smart wound dressings,human-machine interactions,and self-driven anti-infection therapy.     

A 45 nm 8-Core Enterprise Xeon¯ Processor

This paper describes a 2.3 Billion transistors, 8-core, 16-thread, 64-bit Xeon^? EX processor with a 24 MB shared L3 cache implemented in a 45 nm nine-metal process. Multiple clock and voltage domains are used to reduce power consumption. Long channel devices and cache sleep mode are used to minimize leakage. Core and cache recovery improve manufacturing yields and enable multiple product flavors from the same silicon die. The disabled blocks are both clock and power gated to minimize their power consumption. Idle power is reduced by shutting off the unterminated I/O links and shedding phases in the voltage regulator to improve the power conversion efficiency.     

Synthesis of oleic acid-stabilized silver nanoparticles and analysis of their antibacterial activity

The development of new and simple green chemical methods for synthesizing colloidal solutions of functional nanoparticles is desirable for environment-friendly applications. In the present work, we report a feasible method for synthesizing colloidal solutions of silver nanoparticles (Ag NPs) based on the modified Tollens technique. The Ag NPs were stabilized by using oleic acid as a surfactant and were produced for the first time by the reduction of silver ammonium complex [Ag(NH₃)₂]⁺_(aq) by glucose with UV irradiation treatment. A stable and nearly monodisperse aqueous Ag NPs solution with average-sized particles (~ 9–10 nm) was obtained. The Ag NPs exhibited high antibacterial activity against both Gram-negative Escherichia Coli (E. coli) and Gram-positive Staphylococcus aureus bacteria. Electron microscopic images and analyses provided further insights into the interaction and bactericidal mechanism of the Ag NPs. The proposed method of synthesis is an effective way to produce highly bactericidal colloidal solutions for medical, microbiological, and industrial applications.     

High-shear granulation of high-molecular weight hypromellose: effects of scale-up and process parameters on flow and compaction properties

Context: Knowledge of the effects of high-shear granulation process parameters and scale-up on the properties of the produced granules is essential for formulators who face challenges regarding poor flow and compaction during development of modified release tablets based on high-molecular weight hypromellose (hydroxypropylmethylcellulose (HPMC)) polymers. Almost none of the existing studies deal with realistic industrial formulation.

Objective: The aim was to investigate the effects of scale-up and critical process parameters (CPPs) of high-shear granulation on the quality attributes of the granules, particularly in terms of the flow and compaction, using a realistic industrial formulation based on HPMC K100M polymer.

Methods: The flow properties were determined using flow time, Carr index, tablet mass, and crushing strength variations. The compaction properties were quantified using the ‘out-of-die’ Heckel and modified Walker models, as well as the tensile strength profile and elastic recovery. High-shear granulation was performed at different scales: 4?L, 300?L, and 600?L.

Results and conclusion: The scale itself had larger effects on the granule properties than the CPPs, which demonstrated high robustness of formulation on the individual scale level. Nevertheless, to achieve the desired flow and compaction, the values of the CPPs need to be precisely selected to fine-tune the process conditions. The best flow was achieved at high volumes of water addition, where larger and more spherical granules were obtained. The CPPs showed negligible influence on the compaction with no practical implications, however, the volume of water addition volume was identified as having the largest effects on compaction.     

SiRNA drug delivery by biodegradable polymeric nanoparticles

RNA interference (RNAi) is an emerging technology in which the introduction of double-stranded RNA (dsRNA) into a diverse range of organisms and cell types causes degradation of the complementary mRNA. It offers a broad spectrum of applications in both biological and medical research. Small interference RNA (siRNA) was recently explored for its therapeutical potential. However, the drug delivery of siRNA oligos is very novel and is in great need of future research. To this end, a biodegradable poly(D,L-lactide-co-glycolide) (PLGA) nanoparticle drug carrier system was prepared to load siRNA oligos with desired physicochemical properties. The nanoparticles were characterized by scanning electron microscopy and laser diffraction particle sizer. The delivery of siRNA into the targeted 293T cells was observed using fluorescent-labeled double-stranded Cy3-oligos. The model siRNA oligos, si-GFP-RNA, were also successfully loaded into PLGA nanoparticles and delivered in 293T cells. The gene silencing effect and the inhibition of GFP expression were investigated using fluorescent microscopy. Both positive and negative controls were used to compare with the new siRNA nanoparticle delivery system. It was found that nanoparticles offered both effective delivery of siRNA and prominent GFP gene silencing effect. Compared to conventional carrier systems, the new biodegradable polymeric nanoparticle system may also offer improved formulation stability, which is practically beneficial and may be used in the future clinical studies of siRNA therapeutics.