Assessment of the Anti-Microbial Activity of Dried Garlic Powders Produced by Different Methods of Drying

The anti-microbial activity of a range of garlic products including dried garlic powder produced by different methods, commercial garlic products, and garlic oil was determined against a range of selected bacteria. The bacteria included food borne pathogens, spoilage agents, and health-beneficial agents, namely Staphylococcus aureus, Escherichia coli, Salmonella typhimurium, Bacillus cereus, and a mixed lactic culture consisting of Lactobacillus delbrueckii subsp. bulgaricus and Streptococcus thermophilus. The dried powders were produced using air-drying at both 60 and 80°C, vacuum-drying at 50 and 60°C, and freeze-drying at ?20°C. In addition, five commercial products were tested, two of which are used as spices, and three as food supplements. Before testing, the moisture content of the dried garlic powders was raised to that of fresh garlic before drying. Garlic oil was used without any addition of water. In general, the results showed that the lactic culture was the most sensitive to the growth inhibitory active compound of garlic used in this study, followed by Staphylococcus aureus. In contrast Salmonella typhimurium and Bacillus cereus demonstrated the greatest resistance to garlic. Generally, fresh garlic produced the greatest inhibition followed by freeze-dried powder. The anti-microbial activity decreased with decreasing dried garlic powder concentration. The results showed that both drying temperature and time have major effects on retaining the active components responsible for the inhibition of microbial growth. The anti-microbial substances in the moist fresh garlic were also affected by moist-heating temperatures and time. Higher heating temperatures caused faster loss of anti-microbial activity. The decrease in growth-inhibition zones for moist-heated fresh garlic followed zero-order kinetics.     

Bisphenol S in urine from the United States and seven Asian countries: occurrence and human exposures

As concern regarding the toxic effects of bisphenol A (BPA) grows, BPA in many consumer products is gradually being replaced with compounds such as bisphenol S (BPS). Nevertheless, data on the occurrence of BPS in human specimens are limited. In this study, 315 urine samples, collected from the general populations in the United States, China, India, Japan, Korea, Kuwait, Malaysia, and Vietnam, were analyzed for the presence of total BPS (free plus conjugated) concentrations by high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). BPS was detected in 81% of the urine samples analyzed at concentrations ranging from below the limit of quantitation (LOQ; 0.02 ng/mL) to 21 ng/mL (geometric mean: 0.168 ng/mL). The urinary BPS concentration varied among countries, and the highest geometric mean concentration [1.18 ng/mLor 0.933 μg/g creatinine (Cre)] of BPS was found in urine samples from Japan, followed by the United States (0.299 ng/mL, 0.304 μg/g Cre), China (0.226 ng/mL, 0.223 μg/g Cre), Kuwait (0.172 ng/mL, 0.126 μg/g Cre), and Vietnam (0.160 ng/mL, 0.148 μg/g Cre). Median concentrations of BPS in urine samples from the Asian countries were 1 order of magnitude lower than the median concentrations reported earlier for BPA in the same set of samples, with the exception of samples from Japan. There were no significant differences in BPS concentrations between genders (male versus female), or among age groups (categorized as ≤ 19, 20-29, 30-39, 40-49, and ≥ 50 years), or races (Caucasian versus Asian). The daily intake (EDI) of BPS was estimated on the basis of urinary concentrations using a simple pharmacokinetic approach. The median EDI values of BPS in Japan, China, United States, Kuwait, Vietnam, Malaysia, India, and Korea were 1.67, 0.339, 0.316, 0.292, 0.217, 0.122, 0.084, and 0.023 μg/person, respectively. This is the first study to report the occurrence of BPS in human urine.     

Magnetocaloric Effect of Perovskite Manganites Ce0.67Sr0.33MnO3

Magnetocaloric properties of the Ce_0.67Sr_0.33MnO₃ system near a phase transition from a ferromagnetic to a paramagnetic state are investigated. The value of the magnetocaloric effect has been determined from the calculation of magnetization as a function of temperature under different external magnetic fields. The ΔS _M distribution is uniform, which is desirable for an Ericson-cycle magnetic refrigerator. The data show that Ce_0.67Sr_0.33MnO₃ can be used as a working material of an apparatus based on the active magnetic regenerator cycle that cools hydrogen gas from the temperature of liquid natural gas to nearly the boiling point of hydrogen.     

Hydrogen recovery,cleaning, compression,storage, dispensing,distribution system and End-Uses on the university campus from combined heat,hydrogen and power system

To address the problem of fossil fuel usage at the Missouri University of Science and Technology campus, using of alternative fuels and renewable energy sources can lower energy consumption and hydrogen use. Biogas, produced by anaerobic digestion of wastewater, organic waste, agricultural waste, industrial waste, and animal by-products is a potential source of renewable energy. In this work, we have discussed the design of combined heat, hydrogen and power (CHHP) system for the campus using local resources. An energy flow and resource availability study is hydrogen recovery, cleaning and energy End-Uses on the university campus from CHHP system. Following the resource assessment study, our team selects Fuel Cell Energy direct fuel cell (DFC) 1500TM unit as a molten carbonate fuel cell. The CHHP system provides the hydrogen for transportation, back-up power and other needs. The research presented in this paper was performed as part of the 2012 Hydrogen Student Design Contest. In conclusion, the CHHP system will be able to reduce fossil fuel usage, greenhouse gas (GHG) emissions and hydrogen generated is used to power different applications on the university campus.     

Annealing Effects on the Structural,Optical, and UV Photoresponse Properties of ZnO Nanostructures Prepared by RF-Magnetron Sputtering at Different Deposition Temperatures

Undoped Zn O nanostructures were deposited on Si O2/Si substrates via radio frequency magnetron sputtering at different deposition temperatures(room temperature, 200, 300, and 400 °C). The prepared samples were annealed at500 °C for 2 h under an N2 flow. The structural, surface morphological, optical, and photoresponse characteristics of Zn O nanostructures as deposited and after annealing were then investigated. The energy bandgaps of all samples after annealing(3.22–3.28 e V) decreased compared with those of the as-deposited specimens. The barrier height increased when the deposition temperature increased and reached 0.77 e V at 400 °C after annealing with a leakage current of 0.17 l A at a 5 V bias. The UV photodetector device which was deposited at the optimal temperature of 300 °C, has 12.51 9 103% photosensitivity, 2.259 l A dark current, 0.508 s response time, and 0.466 s recovery time. The dark current significantly decreased for all samples after annealing. The proposed UV photodetectors exhibit high performance, high photosensitivity, shorter response and recovery times, and excellent stability at lower bias voltages of 5 and 2 V.     

莲子壳提取物中黄酮类物质的抗氧化活性及结构初探

目的：研究莲子壳中的黄酮类化学成分及抗氧化活性。方法：莲子壳的60% 乙醇提取物经过大孔树脂初步分离之后,采用Toyopearl HW-40S 凝胶柱进一步分离得到了6 个组分(LF-F1～ LF-F6),再采用高效液相以及液质联用系统对其中的组分2(LF-F2)组成及结构进行分析,并采用化学发光法等方法研究了LF-F2 的抗氧化活性。结果：莲子壳黄酮粗提物中总黄酮为94.1%;LF-F2 中黄酮甙元是由槲皮素、杨梅黄酮、山奈酚、异鼠李素等组成的。LF-F2 对超氧阴离子自由基、羟自由基以及对双氧水的清除作用的IC50 分别为420、40、0.6μg/ml。结论：从莲子壳中鉴定出LF-F2 中有芦丁存在。LF-F2 具有很好的抗氧化效果,并存在剂量效应关系。     

Spectral Approaches for the Fast Computation of Yield Surfaces and First-Order Plastic Property Closures for Polycrystalline Materials with Cubic-Triclinic Textures

In recent work, we have demonstrated the viability and computational advantages of DFT-based spectral databases for facilitating crystal plasticity solutions in face-centered cubic (fcc) metals subjected to arbitrary deformation paths. In this paper, we extend and validate the application of these novel ideas to body-centered cubic (bcc) metals that exhibit a much larger number of potential slip systems. It was observed that the databases for the bcc metals with a larger number of slip systems were more compact compared to those obtained previously for fcc metals with a smaller number of slip systems. Furthermore, we demonstrate in this paper that these databases can be effectively used in the fast computation of yield surfaces predicted by the Taylor model for both fcc and bcc metals. As another demonstration of the many advantages of the novel DFT-based spectral databases, we present first-order plastic property closures based on the Taylor model for both fcc and bcc metals. This paper represents the first report of such closures produced without invoking any simplifying assumptions regarding sample symmetry.     

Surfaces with Adjustable Features—Effective and Durable Materials for Water Desalination

Materials based on PVDF with desirable and controllable features were successfully developed. The chemistry and roughness were adjusted to produce membranes with improved transport and separation properties. Membranes were activated using the novel piranha approach to generate OH-rich surfaces, and finally furnished with epoxy and long-alkyl moieties via stable covalent attachment. The comprehensive materials characterization provided a broad spectrum of data, including morphology, textural, thermal properties, and wettability features. The defined materials were tested in the air-gap membrane distillation process for desalination, and improvement compared with pristine PVDF was observed. An outstanding behavior was found for the PVDF sample equipped with long-alkyl chains. The generated membrane showed an enhancement in the transport of 58–62% compared to pristine. A relatively high contact angle of 148° was achieved with a 560 nm roughness, producing a highly hydrophobic material. On the other hand, it was possible to tone the hydrophobicity and significantly reduce adhesion work. All materials were highly stable during the long-lasting separation process and were characterized by excellent effectiveness in water desalination.