Progressive NO2 Sensors with Rapid Alarm and Persistent Memory-Type Responses for Wide-Range Sensing Using Antimony Triselenide Nanoflakes

Antimony triselenide (Sb₂Se₃) nanoflake-based nitrogen dioxide (NO₂) sensors exhibit a progressive bifunctional gas-sensing performance, with a rapid alarm for hazardous highly concentrated gases, and an advanced memory-type function for low-concentration (<1 ppm) monitoring repeated under potentially fatal exposure. Rectangular and cuboid shaped Sb₂Se₃ nanoflakes, comprising van der Waals planes with large surface areas and covalent bond planes with small areas, can rapidly detect a wide range of NO₂ gas concentrations from 0.1 to 100 ppm. These Sb₂Se₃ nanoflakes are found to be suitable for physisorption-based gas sensing owing to their anisotropic quasi-2D crystal structure with extremely enlarged van der Waals planes, where they are humidity-insensitive and consequently exhibit an extremely stable baseline current. The Sb₂Se₃ nanoflake sensor exhibits a room-temperature/low-voltage operation, which is noticeable owing to its low energy consumption and rapid response even under a NO₂ gas flow of only 1 ppm. As a result, the Sb₂Se₃ nanoflake sensor is suitable for the development of a rapid alarm system. Furthermore, the persistent gas-sensing conductivity of the sensor with a slow decaying current can enable the development of a progressive memory-type sensor that retains the previous signal under irregular gas injection at low concentrations.     

如何设计兼具隔离效果和安全性的医疗设备

使用交流电源的医疗设备,可能会因不恰当的接地和电气隔离造成漏电,让患者和医疗人员暴露在危险之下,同时漏电也可能影响到邻近其它医疗设备的性能.对医疗设备来说,EMC是一个相当重要的条件,从2005年11月开始,医疗设备必须符合国际电工委员会(IEC)更新后的IEC 60601-1-2:2001EMC标准.     

Dephytinisation of rice bran and manufacturing a new food ingredient

Rice bran was extruded at 130 °C and a screw speed of 140 rpm for 20 s to inactivate lipase and prevent lipid oxidation. Although the extrusion process induced further complex formation between phytic acid and protein as well as between phytic acid and starch, nearly 94% of phytic acid in the extruded rice bran could still be removed by solid/liquid extraction conducted at 25 °C for 30 min using hydrochloric acid at pH 2 as solvent and a solvent/rice bran ratio of 15. After the extract had been neutralised and phytic acid removed, it was added back to the rice bran solid to replenish the nutritional and functional components of the solid. The mixture was then dried in a drum dryer to yield a powdered product. The dephytinised rice bran product contained most of the protein, fat, dietary fibre and B vitamins and more than 50% of the oryzanol originally present in the raw rice bran. © 2001 Society of Chemical Industry     

PCDD/F adsorption and destruction in the flue gas streams of MWI and MSP via Cu and Fe catalysts supported on carbon

Catalytic destruction has been applied to control polychlorinated dibenzo-p-dioxin and dibenzofuran (PCDD/Fs) emissions from different facilities. The cost of carbon-based catalysts is considerably lower than that of the metal oxide or zeolite-based catalysts used in the selective catalytic reduction (SCR) system. In this study, destruction and adsorption efficiencies of PCDD/Fs achieved with Cu/C and Fe/C catalysts from flue gas streams of a metal smelting plant (MSP) and a large-scale municipal waste incinerator (MWI), respectively, are evaluated via the pilot-scale catalytic reactor system (PCRS). The results indicate that Cu and Fe catalysts supported on carbon surface are capable of decomposing and adsorbing PCDD/ Fs from gas streams. In the testing sources of MSP and MWI, the PCDD/F removal efficiencies achieved with Cu/C catalyst at 250 degrees C reach 96%, however, the destruction efficiencies are negative (-1,390% and -112%, respectively) due to significant PCDD/F formation on catalyst promoted by copper. In addition, Fe/C catalyst is of higher removal and destruction efficiencies compared with Cu/C catalyst in both testing sources. The removal efficiencies of PCDD/Fs achieved with Fe/C catalyst are 97 and 94% for MSP and MWI, respectively, whereas the destruction efficiencies are both higher than 70%. Decrease of PCDD/F destruction efficiency and increase of adsorption efficiency with increasing chlorination of dioxin congeners is also observed in the test via three-layer Fe/C catalyst. Furthermore, the mass of 2,3,7,8-PCDD/Fs retained on catalyst decreases on the order of first to third layer of catalyst. Each gram Fe/C catalyst in first layer adsorbs 10.9, 6.91, and 3.04 ng 2,3,7,8-PCDD/Fs in 100 min testing duration as the operating temperature is controlled at 150, 200, and 250 degrees C, respectively.     

The 4‐acetylantroquinonol B isolated from mycelium of Antrodia cinnamomea inhibits proliferation of hepatoma cells

BACKGROUND: Antrodia cinnamomea is known for its antihepatoma activity, yet the identity of its active compound was unclear. In this study, a 5‐ton fermenter was used to prepare sufficient mycelium of A. cinnamomea for active compound isolation and identification. RESULTS: Using antiproliferative activity toward HepG2 cells as guidance in the isolation process, 4‐acetylantroquinonol B was purified and identified to be the major bioactive compound of A. cinnamomea cultivated by submerged fermentation. The median effective doses (EC₅₀) of 4‐acetylantroquinonol B for HepG2 cells were 0.10 ± 0.00 and 0.08 ± 0.00 µg mL^?1 for 72 and 96 h treatments, respectively. The selective indices of 4‐acetylantroquinonol B were 100 and 125 for 72 and 96 h treatments, respectively, indicating that this compound had high selective activity for hepatoma cells. CONCLUSION: 4‐Acetylantroquinonol B is the major antihepatoma constituent of Antrodia cinnamomea mycelium produced by submerged fermentation. Copyright © 2010 Society of Chemical Industry     

Yam affects the antioxidative and gel‐forming properties of surimi gels

The antioxidative activities and textural properties of pollock surimi gels containing four different yams were determined to evaluate the potential of using yam as a health ingredient and an alternative source for starch in surimi‐based seafoods. Surimi gels containing 20% fresh yam showed higher α,α‐diphenyl‐β‐pricryl‐hydrazyl (DPPH) radicals scavenging activities and total phenolic contents than the gels without yam. Two tested cultivars, 70W34 and 70W35, did not show significant reductions in antioxidative activities when used in surimi gel while three other cultivars revealed species‐dependant declines in both the DPPH scavenging activities and total phenolic contents. The surimi gel containing the cultivar 70R20 showed the highest breaking forces and deformations. In general, 20% fresh yam could be used to form a yam‐containing surimi gel having similar textural properties with a potato starch containing pollock surimi gel. The dried yam powders might be used at the amount of 30% fresh yam equivalent without causing significant losses of the textural properties of pollock surimi gels. Copyright © 2005 Society of Chemical Industry     

Dreams: the convergence of neurobiologic and psychoanalytic perspectives

Fromm's Aristotelian statement that "Dreaming is a meaningful expression of any kind of mental activity under the condition of sleep" (Fromm, 1951, p. 25) is similar to a modern neurobiological conclusion about the dreaming process. The current data from the neurosciences lead to the definition of dreams as a neuropsychological event during sleep whose manifest contents are affect laden, visual, auditory, and kinesthetic. Their functions are adaptive and problem solving in themselves. They are part of the brain's connectionist information-processing system which channel, compare, and integrate current affect-laden memories with memories of past successful strategies. Thus, the neurobiological perspective of dreams provides an underlying neuroanatomical and information-processing matrix for the dream process that further supports the current psychoanalytic view concerning their assimilative and accommodative functions. In conclusion, I would like to return to the termination phase of Mr. M's therapy. This patient planned to leave therapy approximately 22 months after the occurrence of Dream 2, as this dream had predicted. He was to be married and move to another city. Although I felt somewhat anxious about his leaving, despite his significant progress, we agreed to a termination date. Just prior to the second-to-last session Mr. M had the following dream: It took place in a large gothic building in a zoo. It is dark and depressing and filled with cages of rhesus monkeys. I go around with a nurse to inoculate the monkeys. I am scared of the virus. My future wife appears. She is immune to the virus. She is brave and she rescues me. The patient seemed pleased in relating his dream, and it offered resolution and closure for both of us despite a paucity of discussion. Two years later I received a letter from him in which he stated that he was well and had no additional "monkey dreams."     

Destruction of VOCs via Silent Discharge Plasmas

Silent discharge plasmas (SDP) are effective in generating free radicals which are highly reactive with organic compounds. This characteristic is a key element for highly volatile organic compounds (VOC) destruction efficiency achieved with SDPs. Various studies indicate that SDPs are effective in decomposing a wide range of gaseous contaminants and have the potential to be developed as a viable alternate technology for destroying volatile organic compounds in gas streams.     

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     

Silver bullet or trojan horse? The effects of inclusionary zoning on local housing markets in the United States

Many local governments are adopting inclusionary zoning (IZ) as a means of producing affordable housing without direct public subsidies. In this paper, panel data on IZ in the San Francisco metropolitan area and suburban Boston are used to analyse how much affordable housing the programmes produce and how IZ affects the prices and production of market-rate housing. The amount of affordable housing produced under IZ has been modest and depends primarily on how long IZ has been in place. Results from suburban Boston suggest that IZ has contributed to increased housing prices and lower rates of production during periods of regional house price appreciation. In the San Francisco area, IZ also appears to increase housing prices in times of regional price appreciation, but to decrease prices during cooler regional markets. There is no evidence of a statistically significant effect of IZ on new housing development in the Bay Area.