ABSTRACT
We report a case of a solitary osteochondroma as a dumbbell tumor compressing the spinal cord and its surgical strategy. The patient is a 16-year-old female with longstanding posterior neck pain and left arm abduction weakness. She was examined by plain X-ray, three-dimensional-computed tomography, magnetic resonance imaging, and vertebral angiography. The analyses indicated a calcified extradural mass compressing the cord in the C3-4 portion extending into the neural and vertebral foramen with eroded vertebral body. The tumor was successfully excised using a modified combined anterior and posterior approach. Histopathologic study of the resected material confirmed the diagnosis. The postoperative assessment was followed by clinical and radiologically therapy for 5 years after surgery. Osteochondroma arises from enchondral bone but it rarely involves the spine, especially not as s dumbbell type. In this patient, the tumor may have arisen from the neural arch and extended into the extradural and extraforaminal space over a long period. We successfully removed the dumbbell tumor with a combined anterior oblique and posterior approach. However, further observation is essential because of the possibility of recurrence and sarcomatous change.
ABSTRACT
Dye-sensitized solar cells (DSSCs) were assembled using natural dyes extracted from red cabbage as a sensitizer. In this work, we investigated the adsorption characteristics and the electrochemical behavior for harvesting sunlight and electron transfer in red cabbage DSSCs under different solvents and pH. For the red cabbage dye-sensitized electrode adsorbed at pH 3.5, the solar cell yields a short-circuit current density (Jsc) of 1.60 mA/cm2, a photovoltage (Vcc) of 0.46 V, and a fill factor of 0.55, corresponding to an energy conversion efficiency (η) of 0.41%.
Subject(s)
Brassica/chemistry , Coloring Agents/chemistry , Electric Power Supplies , Plant Extracts/chemistry , Solar Energy , Coloring Agents/isolation & purification , Coloring Agents/radiation effects , Electric Conductivity , Electrodes , Energy Transfer/radiation effects , Equipment Design , Equipment Failure Analysis , Hydrogen-Ion Concentration , Light , Materials Testing , Plant Extracts/radiation effectsABSTRACT
We have successfully introduced green phosphors LaPO4:Ce, Tb (G4) or (Mg, Zn)Al11O19:Eu (G2) into TiO2 photoelectrode of dye-sensitized solar cells. The conversion efficiency of the G4-doped device was enhanced by 30% compared with the pristine TiO2 photoelectrode. The green phosphor doped at 5-wt.% ratio contributed to the reduction of resistances of the surface and interface of the photoelectrode and to the great enhancement of the absorption spectrum in UV-visible and near-infrared regions. The internal resistances and absorbance of the photoelectrode directly affect the power conversion efficiency. Green phosphor plays an important role towards the realization of high-efficiency dye-sensitized solar cells.
ABSTRACT
An anatase TiO2 and three kinds of novel TiO2 nanoparticles were prepared by a hydrothermal method for dye-sensitized solar cells (DSSCs), which were obtained by mixing NaOH (10 M), KOH (14 M) and LiOH (10 M) solution with an anatase TiO2 powder, respectively. The TiO2 working electrodes of DSSCs were prepared and the photoelectric properties of the cells were characterized. The influence of different poly(ethylene glycol) contents in TiO2 films with and without HNO3 treatment on the electron transfer in DSSCs were investigated. It is found that the DSSC with HNO3 (0.002 mol/l)-treated film containing 16.7 wt% PEG shows the higher power conversion efficiency of 6.0%, which was mainly depended on the degrees of TiO2 pore size and uniformity of TiO2 films.
ABSTRACT
This work reports a rapid, specific and sensitive multi-residue method based on the Quick Easy Cheap Effective Rugged and Safe (QuEChERS) sample preparation method and gas chromatography with mass spectrometric detection in the selected ion monitoring mode (GC-MS-SIM) using one quantification ion and two identification ions for the routine analysis of 203 pesticides in rice paddies. Analyses of fortified rice paddy samples were performed at different levels (0.05, 0.20 and 0.50 mg kg(-1)). Mean recoveries from five replicates ranged from 75% to 115%, with coefficients of variation lower than 17%. The limit of quantification was in the range of 0.002-0.05 mg kg(-1) for the pesticides. 1040 rice paddy samples were analyzed for method application.
ABSTRACT
This study was designed to develop a microencapsulated, water-soluble isoflavone for application into milk and to examine the hypocholesterolemic effect of such a milk product in a rat diet. The coating material was medium-chain triglyceride (MCT) and the core material was water-soluble isoflavone. The microencapsulation efficiency was 70.2% when the ratio (w/w) of coating material to core material was 15:1. The isoflavone release from the microcapsules was 8% after 3-day storage at 40 degrees C. In in vitro study, 4.0-9.3% of water-soluble isoflavone in simulated gastric fluid was released in the pH range of 2 to 5 after 60 min incubation; however, in simulated intestinal fluid at pH 8, 87.6% of isoflavone was released from the capsules after 40 min incubation time. In sensory analysis, the scores of bitterness, astringency, and off-taste in the encapsulated isoflavone-added milk were slightly, but not significantly, different from those in uncapsulated, isoflavone-added milk. In blood analysis, total cholesterol was significantly decreased in the isoflavone-added group compared with that in the control after 6-week feeding. Therefore, this study confirmed the acceptability of MCT as a coating material in the microencapsulation of water-soluble isoflavone for application into milk, although a slight adverse effect was found in terms of sensory attributes. In addition, blood total cholesterol was lowered in rats which had been fed a cholesterol-reduced and microencapsulated, isoflavone-added milk for 6 weeks.
