Nanocrystalline scheelite SrWO4: a low temperature co-fired ceramic optical material-synthesis and properties

Nanocrystalline strontium tungstate (SrWO₄) is synthesized through a single step modified combustion process. The X-ray diffraction, Fourier transform Raman and Infrared spectroscopy studies reveal that the as-prepared powder is single phase and possess tetragonal structure. The transmission electron microscopic investigations have shown that the particle size of the as prepared powder is in the range 18–22 nm. The optical constants are estimated from the UV–Visible studies and calculated optical band gap is 4.28 eV. The sample showed maximum transmission in the visible regions but poor transmittance in the ultraviolet region. The photoluminescence spectra recorded at different temperatures showed intense blue emission. The nanocrystalline SrWO₄ obtained by the present combustion method was sintered to 95 % density at a relatively lower temperature of 810 °C for 3 h. The dielectric constant (ε_r) and loss factor (tan δ) of the sintered SrWO₄ pellets at 5 MHz measured at room temperature were 9.9 and 6.29 × 10^?3 respectively. The experimental results obtained in this work demonstrate the application of SrWO₄ as UV filters, transparent films for window layers on solar cells, anti-reflection coatings, scintillators, detectors and for low-temperature co-fired ceramic applications.     

Curcumin and Liver Disease: from Chemistry to Medicine

Curcumin, the natural yellow‐colored active principle, also called turmeric yellow, extracted from the perennial herb Curcuma longa L., has potent biological and pharmacological properties such as antioxidant, anti‐inflammatory, antifungal, antibacterial, anti‐ischemic, antitumor, and anticancer actions. The molecular mechanism of the hepatoprotective action of curcumin is due to its antioxidant properties and inhibitory activity against nuclear factor (NF)‐κB that regulates different proinflammatory and profibrotic cytokines. Overall, scientific reports demonstrate that curcumin has high therapeutic ability for treating hepatic disorders. Here is a systematic discussion of the hepatoprotective activity of curcumin and its possible mechanisms of actions.     

Metal recovery from jarosite waste – A resin screening study

Work has been carried out screening hydrometallurgical resins for application in the valorization of industrially produced jarosite. Of the seven resins tested, anion exchange resins performed poorly for valuable metal recovery. Purolite S950+ and S957, along with a strong acid resin, show good extraction properties, but are selective for Fe³⁺ over the other (divalent) metals. Purolite S930+ (iminodiacetic acid-functionalized resin) demonstrates selectivity for Cu²⁺ over Fe³⁺, but poor selectivity for Ni²⁺, Zn²⁺, and Co²⁺. Dowex M4195 (bispicolylamine-functionalized resin) demonstrates promise for extracting metals of value away from a mixed metal pregnant liquor solution (PLS). A three-stage column-based recovery process is proposed for jarosite leachate treatment.     

Reduction of spoilage microorganisms in fresh beef using hydrodynamic pressure processing

Hydrodynamic pressure processing (HDP) was investigated as a technology to reduce spoilage microorganisms found in fresh beef. In two separate studies (studies 1 and 2), retail ground beef and beef roasts were purchased (day 0). The roasts were divided into stew pieces (30 to 40 g). All meat samples, including control samples, were stored at 5 degrees C for 20 h in a plastic film. After storage, designated samples were treated with HDP In study 3, ground beef was treated with HDP (day 0) and stored aerobically (5 degrees C) for 14 days with control samples. Each meat type was vacuum-packaged for HDP (100 g binary explosive, steel shock wave container). The pHs and the aerobic plate counts (log10 CFU/g) were measured on day 0 (studies I and 2) and on days 0, 7, and 14 (study 3) for control samples and for HDP-treated samples. There was no pH difference between control and HDP-treated meat types (studies 1 and 2); HDP reduced bacteria in both meat types in study 1 (2 log) and study 2 (1.5 log) on day 0. In study 3, there was a significant difference (P < 0.05) in pH between control meat (8.2) and HDP-treated meat (5.6) after storage. There was an immediate reduction (1.5 log) of microorganisms following HDP (day 0) and a 4.5-log difference between control samples (9 log) and HDP-treated samples (4.5) after 14 days of storage. With HDP, it is possible to reduce spoilage microorganisms found in or on different meat types (ground beef versus stew pieces), which could extend the shelf life of meat products.     

Effect of irrigation method on transmission to and persistence of Escherichia coli O157:H7 on lettuce

In this study, the transmission of Escherichia coli O157:H7 to lettuce plants through spray and surface irrigation was demonstrated. For all treatments combined, the number of plants testing positive following a single exposure to E. coli O157: H7 through spray irrigation (29 of 32 plants) was larger than the number testing positive following surface irrigation (6 of 32 plants). E. coli O157:H7 persisted on 9 of 11 plants for 20 days following spray irrigation with contaminated water. Immersion of harvested lettuce heads for 1 min in a 200 ppm chlorine solution did not eliminate all E. coli O157:H7 cells. The results of this study suggest that regardless of the irrigation method used, crops can become contaminated; therefore, the irrigation of food crops with water of unknown microbial quality should be avoided.     

Toll road crashes of commercial and passenger motor vehicles

Revenue-collection data from toll roads allow for accurate estimates of miles driven by vehicle type and, when combined with crash data, valid estimates of crash involvements per mile driven. Data on vehicle-miles traveled and collisions were obtained from toll road authorities in Florida. Kansas, and New York. In addition, state crash files and published vehicle-miles of travel were obtained for toll roads in Illinois. Indiana, Ohio, and Pennsylvania. Large commercial motor vehicles were significantly underinvolved in single-vehicle crashes on all state toll roads. In five states, commercial motor vehicles were significantly overinvolved in multiple-vehicle crashes relative to passenger vehicles; the exceptions were Kansas, where they had significantly lower multiple-vehicle involvement rates, and Indiana. where there were no significant differences in multiple-vehicle involvements by vehicle type. The risk of commercial motor vehicle involvement in multiple-vehicle crashes resulting in deaths or serious injuries was double that of passenger vehicles in the two states (Ohio and Pennsylvania) that identified serious injuries. Whether crash rates, on toll roads of commercial motor vehicles are higher or lower than those of passenger vehicles appears to depend on the type of crash, specific toll road. and traffic density.     

Overdependence on degraded gist memory in Alzheimer's disease.

Alzheimer's disease (AD) reduces associative effects on false recognition in the Deese-Roediger-McDermott task, either due to impaired memory for gist or impaired use of gist in memory decisions. Gist processes were manipulated by blocking or mixing studied words according to their associations and by varying the associative strength between studied and nonstudied words at test. Both associative blocking and associative strength had smaller effects on false recognition in AD patients than in control participants, consistent with gist memory impairments. However, unlike the case with control participants, blocking influenced true and false recognition equally in AD patients, demonstrating an overdependence on gist when making memory decisions. AD also impaired item-specific recollections, relative to control participants, as true recognition of studied words was reduced even when the two groups were equated on gist-based false recognition. We propose that the overdependence on degraded gist memory in AD is caused by even larger impairments in item-specific recollections. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An ELISA for brown trout (Salmo trutta) vitellogenin and its use in bioassays for environmental estrogens

An enzyme linked immunosorbent assay (ELISA) was developed for the detection of the egg yolk precursor vitellogenin (Vg) in plasma of brown trout (Salmo trutta). Purified Vg from a 17 beta-estradiol-induced trout was used as the competing antigen in the ELISA which is based on polyclonal antibodies. The ELISA's performance was optimized and characterized. The assay's working range was (25-500 ng ml-1), its sensitivity was (10.5 ng ml-1), and it had an intra-assay coefficient of variation of less than 10% between 30 and 1000 ng ml-1. The ELISA was used in bioassays for the detection of environmental estrogens, including estrogen mimics, in whole and fractionated industrial waste waters. Those bioassays were based on intraperitoneal (i.p.) injection-, static renewal-, and flow through exposure systems. The response threshold of both bioassays is limited to 1-2 micrograms ml-1 Vg by a low level plasma interference that was regularly detected in plasma from non-induced male fish. The responsiveness of the bioassays was characterized using progressive doses of 17 beta-estradiol. The i.p.-based assay, which was responsive to at least 100 micrograms kg-1 of 17 beta-estradiol, was used to screen extracts of pulp mill effluent and black liquor for estrogenic effects. Neither extract induced Vg in our assay. The i.p. assay was also used to test 4-tert-octylphenol (OP) and the PAH derivative, retene, for estrogenic activity. OP induced Vg in the i.p.-exposed fish; no Vg induction was detected in the retene-exposed fish. The static renewal bioassay, which was responsive to at least 0.1 microgram ml-1 of 17 beta-estradiol over a 15-day exposure period, was used to screen whole pulp mill effluents for estrogenic effects. No Vg induction was detected in the effluent-treated fish.