Effects of propofol on alterations of multineuronal activity of limbic and mesencephalic structures and neurological deficit elicited by acute global cerebral ischemia

The increment of GABAergic inhibitory activity, the reduction of metabolic rate and oxygen consumption induced by propofol on the neuronal components of brain structures, and its antioxidant potential have supported the possible beneficial effects of this drug against brain damage elicited by cerebral ischemia. Multineuronal activity (MUA) and EEG from mesencephalic reticular formation, hippocampus, and amygdala, and EEG from the parietooccipital cortex were recorded and analyzed during vehicle or propofol, 0.25 mg/kg/min i.v., administered during a 6 h period following a 10 min cardiorespiratory arrest and 2-4 min of reanimation in two groups of cats under neuromuscular blockade and assisted ventilation. This was continued daily during alertness for 8 days after cardiorespiratory arrest along with determining daily neurological deficit scores. Mean MUA frequency, progressively increasing in subcortical structures of untreated cats during the hours following cardiorespiratory arrest, was significantly lower in propofol treated cats. A significant reduction of MUA in the hippocampus was then observed in the untreated but not in the propofol treated cats, and in amygdala in both treated and untreated cats. Alterations of MUA were not observed in the mesencephalic reticular formation during alertness on the days after cardiorespiratory arrest. Significantly lower neurological deficit scores were recorded in propofol treated than in untreated cats the days after cardiorespiratory arrest. It can be concluded that propofol is capable of reducing both brain electrical activity alterations in specific brain structures, and neurological deficit elicited by complete global cerebral ischemia in cats. Inhibition of MUA from limbic and mesencephalic brain structures induced by propofol early after global cerebral ischemia could be related to these effects.     

Demonstration of a real-time interferometer as a bunch-length monitor in a high-current electron beam accelerator

A real-time interferometer (RTI) has been developed to monitor the bunch length of an electron beam in an accelerator. The RTI employs spatial autocorrelation, reflective optics, and a fast response pyro-detector array to obtain a real-time autocorrelation trace of the coherent radiation from an electron beam thus providing the possibility of online bunch-length diagnostics. A complete RTI system has been commissioned at the A0 photoinjector facility to measure sub-mm bunches at 13 MeV. Bunch length variation (FWHM) between 0.8 ps (~0.24 mm) and 1.5 ps (~0.45 mm) has been measured and compared with a Martin-Puplett interferometer and a streak camera. The comparisons show that RTI is a viable, complementary bunch length diagnostic for sub-mm electron bunches.     

A Transparent,Wearable Fluorescent Mouthguard for High-Sensitive Visualization and Accurate Localization of Hidden Dental Lesion Sites

Accurate detection and early diagnosis of oral diseases such as dental caries and periodontitis, can be potentially achieved by detecting the secretion of volatile sulfur compounds (VSCs) in oral cavities. Current diagnostic approaches for VSCs can detect the existence and concentrations, yet are not capable of locating the dental lesion sites. Herein, the development of a unique approach for accurately locating dental lesion sites using a fluorescent mouthguard consisting of the zinc oxide–poly(dimethylsiloxane) (ZnO-PDMS) nanocomposite to detect the local release of VSCs is reported. The ZnO-PDMS mouthguard displays a highly sensitive and selective response to VSCs, and exhibits high fluorescent stability, good biocompatibility, and low biological toxicity in normal physiological environments. Then, the wearable ZnO-PDMS mouthguard is demonstrated to be able to identify the precise locations of lesion sites in human subjects. Combined with image analysis, the mouthguards successfully uncover the precise locations of dental caries, allowing convenient screening of hidden dental lesion sites that are oftentimes omitted by dentists. Due to low cost, long-term stability, and good patient compliance, the proposed wearable mouthguard is suitable for large-scale production and enables widely applicable, preliminary yet accurate screening of dental lesions prior to dental clinics and routine physical examinations.     

Assessment of Edible Fungi and Films Bio-Based Material Simulating Expanded Polystyrene

Expanded polystyrene (EPS) contains benzene and styrene, posing a risk to human health. Research objective was to create and evaluate a bio-based material that mimics EPS physical and mechanical properties; this material was developed from crop residues (Triticum sp.), fungi (Pleurotus sp.), and edible films (carrageenan, chitosan, and xanthan gum). Treatments differed in the type of film applied over the bio-based material, and physical and mechanical properties were evaluated. Compressive and flexural strength ranged from 20 to 60 kPa and 4.6 to 17.9 kPa, respectively; dimensional stability and relative density ranged from 5.1 to 7.3% and 178.7 to 198.9 kg m^?3, respectively. The bio-based material does not pose to be an alternative to EPS yet, and further researches must assess water absorption and biodegradability.     

Optical techniques to determine thermal effects on proteins

Optical rotation (OR) and transmitted light (TL) measurements were conducted on 1%, 2.5% and 5% (w/v) bovine serum albumin (BSA) in 0.01 m phosphate buffer at pH 7 and ionic strength 0.08. Denaturation temperatures (T_d) obtained from OR measurements were consistent with reported differential scanning calorimetry values. Protein concentration did not affect T_d in agreement with most reports. Changes in TL reflecting gel formation and protein aggregation were influenced by BSA concentration. Sugar concentration in the range used in this study (0–5%) did not affect the thermal stability of BSA. The lack of difference in sucrose, trehalose and sorbitol effects on the thermal stability of BSA was consistent with some but not all reports. The optical system used to study protein denaturation had acceptable accuracy (consistency with published T_d values) and precision (coefficient of variation under 3.5%) levels.     

CO2 absorption intensification using three-dimensional printed dynamic polarity packing in a bench-scale integrated CO2 capture system

Postcombustion carbon capture using a chemical absorbent is a promising technology to reduce CO₂ emission. However, the overall construction and operating costs remain a major challenge. In order to intensify the absorption process and to reduce these costs, a novel dynamic polarity structured packing (DP packing) with alternate patterns of surface polarity has been developed to enhance local macro-scale turbulence within the advanced viscous solvent to reduce the mass transfer diffusion resistance. Three DP structured packings that incorporate multiple polymeric materials were fabricated using three-dimensional printing technique and evaluated through parametric testing using a bench-scale integrated CO₂ capture unit with 76.2 mm ID absorber. At optimized operating conditions, the DP packing showed a relative 22.7% increase in absorption and 20.0% decrease in energy penalty.     

Effect of benzyl isothiocyanate on tomato fruit infection development by Alternaria alternata

Benzyl isothiocyanate (BITC) is known to be a strong antifungal compound in vitro against different fungi. The effectiveness of benzyl isothiocyanate to control Alternaria alternata growth in vitro and in vivo was tested. BITC in vitro activity was evaluated in A alternata growing on potato dextrose agar and exposed to 0.025, 0.05, 0.1, 0.2 or 0.4 mg ml^?1. In vivo activity was evaluated by exposing A alternata‐inoculated tomato fruits for either 18 or 36 h to 0.28 or 0.56 mg ml^?1 BITC packed on low‐density polyethylene film (LDPF) bags. Additionally, the effect of BITC on post‐harvest physiology and tomato quality throughout storage at 20 °C was evaluated daily by monitoring respiration rate and ethylene production, whereas total soluble solids, pH, titratable acidity and fresh weight loss were measured every 3 days. Results showed that the minimal inhibitory concentration of BITC in vitro was 0.1 mg ml^?1. A combined use of 0.56 mg ml^?1 BITC with LDPF for 18 h was the optimum treatment to control Alternaria rot in packed tomato fruit. No effect of BITC on respiration rate, ethylene production, total soluble solids, pH, weight loss and titratable acidity was observed. Results suggest that BITC can be used as a post‐harvest treatment to control Alternaria rot in tomato fruit without detrimental effects on the tomato post‐harvest quality. Copyright © 2005 Society of Chemical Industry     

Some physicochemical and antinutritional properties of raw flours and protein isolates from Mucuna pruriens (velvet bean) and Canavalia ensiformis (jack bean)

The legumes Canavalia ensiformis and Mucuna pruriens are underexploited in tropical Mexico. Their seeds have good nutritional potential, but contain antinutritional factors. Physicochemical and antinutritional properties were determined for raw flours (RF) and protein isolates (PI) produced from these legumes. Protein content in the PI was 737 g kg^–1 for C. ensiformis and 666 g kg^–1 for M. pruriens. Protein isolation improved in vitro digestibility, while maintaining high lysine levels and adequate sulphur amino acids content. Antinutritional factors such as cyanogenic glucosides, cyanide precursors from hydrolysis, tannins and trypsin inhibitors were lower in the PIs than in the RFs. The reduction in canavanine levels, a structural analogue of arginine, in the C. ensiformis PI was noteworthy. These PIs thus have potential applications in the development of new food ingredients in tropical regions using processes that improve nutritional value.     

Synergistic effects of nanotexturization and down shifting CdTe quantum dots in solar cell performance

In order to promote the widespread utilization of photovoltaic structures it is critical to increase their conversion efficiency and reduce their manufacturing cost. With these two goals in mind, planar and nanotexturized c-Si photovoltaic devices were built and their radiation incident side was covered with CdTe quantum dots (QDs) dispersed in a poly-methyl-methacrylate thin film ~100 nm thick. The measured performance with and without the CdTe QD layer indicates that the down-shifting photoluminescence (DSPL) of the synthesized QDs triggers an increase in the open circuit voltage and the short circuit current, resulting in an overall improvement of ~1.5 % in the power conversion efficiency of the produced devices. This observation can be understood as a result of decreasing the number of high energy photons that are prone to unproductive near surface absorption in c-Si p-n junction solar cells and the re-emission of lower energy photons that are more effectively bulk-absorbed in c-Si solar cells. The result of lowering the near surface photon absorption represents a reduction of carrier losses due to the high surface recombination velocity as well as the low lifetime that normally plague the diffused side of an active junction device. Additionally, solar cells with a layer of CdTe QDs exhibit a higher external quantum efficiency when compared to devices without the aforementioned quantum dots. Layers of CdTe QDs are economically attractive, highly photostable and their absorption and emission spectra have a strong dependence on particle size, therefore, they lend themselves to providing a broad DSPL spectrum and promoting the proliferation of photovoltaic structures.