Design and implementation of a RF powering circuit for RFID tags or other batteryless embedded devices.

A RF powering circuit used in radio-frequency identification (RFID) tags and other batteryless embedded devices is presented in this paper. The RF powering circuit harvests energy from electromagnetic waves and converts the RF energy to a stable voltage source. Analysis of a NMOS gate-cross connected bridge rectifier is conducted to demonstrate relationship between device sizes and power conversion efficiency (PCE) of the rectifier. A rectifier with 38.54% PCE under normal working conditions is designed. Moreover, a stable voltage regulator with a temperature and voltage optimizing strategy including adoption of a combination resistor is developed, which is able to accommodate a large input range of 4 V to 12 V and be immune to temperature variations. Latch-up prevention and noise isolation methods in layout design are also presented. Designed with the HJTC 0.25 µm process, this regulator achieves 0.04 mV/°C temperature rejection ratio (TRR) and 2.5 mV/V voltage rejection ratio (VRR). The RF powering circuit is also fabricated in the HJTC 0.25 µm process. The area of the RF powering circuit is 0.23 × 0.24 mm². The RF powering circuit is successfully integrated with ISO/IEC 15693-compatible and ISO/IEC 14443-compatible RFID tag chips.

Chemical characterization and antitumor activities of polysaccharide extracted from Ganoderma lucidum.

Ganoderma lucidum polysaccharide (GLP) is a biologically active substance reported to possess anti-tumor ability. Nonetheless, the mechanisms of GLP-stimulated apoptosis are still unclear. This study aims to determine the inhibitory and apoptosis-inducing effects of GLP on HCT-116 cells. We found that GLP reduced cell viability on HCT-116 cells in a time- and dose-dependent manner, which in turn, induced cell apoptosis. The observed apoptosis was characterized by morphological changes, DNA fragmentation, mitochondrial membrane potential decrease, S phase population increase, and caspase-3 and -9 activation. Furthermore, inhibition of c-Jun N-terminal kinase (JNK) by SP600125 led to a dramatic decrease of the GLP-induced apoptosis. Western blot analysis unveiled that GLP up-regulated the expression of Bax/Bcl-2, caspase-3 and poly (ADP-ribose) polymerase (PARP). These results demonstrate that apoptosis stimulated by GLP in human colorectal cancer cells is associated with activation of mitochondrial and mitogen-activated protein kinase (MAPK) pathways.

The inhibiting activity of areca inflorescence extracts on human low density lipoprotein oxidation induced by cupric ion.

The oxidative modification of human low density lipoprotein (LDL) plays a significant role in atherosclerosis. In this study, the inhibiting activity of areca inflorescence extracts (AIEs) on LDL oxidation was investigated by an in vitro study with Trolox as the standard antioxidant. The kinetics of LDL oxidation, thiobarbituric acid reactive substances assay, ferric-reducing antioxidant power assay and copper chelation assay were also evaluated to assess the antioxidant activities of AIEs, and the results revealed that AIEs could delay the lag time and inhibit the formation of malondialdehyde in the process of LDL peroxidation induced by Cu(2+). The boiled water extract displayed the highest antioxidant activity compared with the ambient water extract and ethanol extract. The total phenolic contents and phenolic components of AIEs were also measured by high performance liquid chromatography method. Epicatechin, gallic acid and coumalic acid were the primary phenolic acids in AIEs.

Improvement of antifungal activity of a culture filtrate of endophytic Bacillus amyloliquefaciens isolated from kiwifruit and its effect on postharvest quality of kiwifruit.

This study reports the optimization of culture conditions and medium components of M9, an endophytic strain of Bacillus amyloliquefaciens, which we had previously isolated from kiwifruit, and evaluation of its effect on kiwifruit postharvest protection against soft rot. The method of one-factor-at-a-time was used to determine the optimum culture conditions, and response surface methodology was applied to optimize the medium constituents. After optimization, a high rate of antifungal activity (73.12% decrease in decay rate) by M9 culture filtrate against the soft rot fungal pathogen, Botryosphaeria dothidea, was obtained. Compared with the initial culture conditions, the antifungal activity of M9 culture filtrate was increased by 19.5%. Furthermore, a postharvest storage experiment on kiwifruit showed that M9 culture filtrate could maintain the quality of stored kiwifruit, delay fruit senescence, and significantly enhance the storability of kiwifruit. Using liquid chromatography-mass spectrometry, we found that the antifungal activity of M9 was associated with the presence of the C12-surfactin A lipopeptide. PRACTICAL APPLICATIONS: Soft rot caused by Botryosphaeria dothidea is one of the most important diseases of kiwifruit, causing postharvest fruit rot. The disease progresses rapidly and is difficult to control, posing a great threat to the kiwifruit industry. In this study, the culture conditions and medium composition for culture of the strain M9 (kiwifruit endophytic Bacillus amyloliquefaciens) were optimized to maximize the inhibition of B. dothidea. A postharvest storage experiment showed that M9 culture filtrate could improve the disease resistance of kiwifruits, delay the senescence of the fruits, and maintain the quality of kiwifruit during storage. Because M9 is a natural endophyte of kiwifruit, the strategy used in this study was both effective and safe. This work will contribute to the exploitation of B. amyloliquefaciens in controlling the pathogens of kiwifruit and the development of safer and more advanced strategies for the postharvest protection of kiwifruits.

Inhibition of migration and induction of apoptosis in LoVo human colon cancer cells by polysaccharides from Ganoderma lucidum.

Ganoderma lucidum polysaccharides (GLPs), which were purified from the medicinal herb G. lucidum followed by ethanol precipitation, protein depletion using the Sevage assay, purification using DEAE­cellulose (DE-52), dialysis and the use of ultrafiltration membranes, are used as an ingredient in traditional anticancer treatments in China. The aim of the current study was to evaluate the anticancer effects and investigate the underlying molecular mechanisms of GLPs on LoVo human colon cancer cells. The results demonstrated that the GLP­mediated anticancer effect in LoVo cells was characterized by cytotoxicity, migration inhibition, enhanced DNA fragmentation, morphological alterations and increased lactate dehydrogenase release. Furthermore, the activation of caspases­3, ­8 and ­9 was involved in GLP­stimulated apoptosis. Additionally, treatment with GLPs promoted the expression of Fas and caspase­3 proteins, whilst reducing the expression of cleaved poly(ADP­ribose) polymerase. These data indicate that GLPs demonstrate potential antitumor activity in human colon cancer cells, predominantly through the inhibition of migration and induction of apoptosis. Furthermore, activation of the Fas/caspase-dependent apoptosis pathway is involved in the cytotoxicity of GLPs.

Ganoderma lucidum polysaccharides target a Fas/caspase dependent pathway to induce apoptosis in human colon cancer cells.

Ganoderma lucidum polysaccharides (GLP) extracted from Ganoderma lucidum have been shown to induce cell death in some kinds of cancer cells. This study investigated the cytotoxic and apoptotic effect of GLP on HCT-116 human colon cancer cells and the molecular mechanisms involved. Cell proliferation, cell migration, lactate dehydrogenase (LDH) levels and intracellular free calcium levels ([Ca(2+)]i) were determined by MTT, wound-healing, LDH release and fluorescence assays, respectively. Cell apoptosis was observed by scanning and transmission electron microscopy. For the mechanism studies, caspase-8 activation, and Fas and caspase-3 expression were evaluated. Treatment of HCT-116 cells with various concentrations of GLP (0.625-5 mg/mL) resulted in a significant decrease in cell viability (P< 0.01). This study showed that the antitumor activity of GLP was related to cell migration inhibition, cell morphology changes, intracellular Ca(2+) elevation and LDH release. Also, increase in the levels of caspase-8 activity was involved in GLP-induced apoptosis. Western blotting indicated that Fas and caspase-3 protein expression was up-regulated after exposure to GLP. This investigation demonstrated for the first time that GLP shows prominent anticancer activities against the HCT-116 human colon cancer cell line through triggering intracellular calcium release and the death receptor pathway.