DERMATOLOGIC SURGERY, Issue 3 2005
Nicholas J. Lowe MD
Background Published evidence suggests that botulinum toxin type A (BTX-A) is an effective treatment for crow's feet. However, few dose-ranging studies have been performed. Objectives To assess the safety and efficacy of a single treatment with one of four doses of BTX-A (Botox/Vistabel, Allergan Inc) compared with placebo for the improvement of crow's feet. Methods Subjects received a single bilateral treatment of 18, 12, 6, or 3 U of BTX-A or placebo injected into the lateral aspect of the orbicularis oculi muscle (parallel-group, double,blind design). Investigators and subjects rated crow's feet severity at maximum smile on day 7 and at 30-day intervals from days 30 to 180. Results As observed by both investigators and subjects, all doses of BTX-A resulted in improvements in crow's feet severity when compared with placebo. A dose-dependent treatment effect for efficacy was observed, with higher doses having an increased magnitude and duration of effect. However, a clear differentiation between the 18 U and 12 U doses was not apparent. Few adverse events were reported, with no statistically significant differences between BTX-A and placebo in the incidence of subjects experiencing adverse events. Conclusion BTX-A is safe and effective in decreasing the severity of crow's feet, with 12 U per side suggested as the most appropriate dose. THIS STUDY WAS FUNDED BY ALLERGAN, WHICH WAS ALSO INVOLVED IN THE DESIGN AND CONDUCT OF THE STUDY; COLLECTION, MANAGEMENT, ANALYSIS, AND INTERPRETATION OF THE DATA; AND PREPARATION, REVIEW, AND APPROVAL OF THE MANUSCRIPT. DRS. LOWE AND FRACZEK ARE PAID CONSULTANTS FOR ALLERGAN, DRS. KUMAR AND EADIE ARE EMPLOYEES OF ALLERGAN, AND DRS. LOWE AND KUMAR HOLD STOCK OPTIONS. [source]

PREPARATION AND CHARACTERIZATION OF PEPSIN-SOLUBILIZED TYPE I COLLAGEN FROM THE SCALES OF SNAKEHEAD (OPHIOCEPHALUS ARGUS)

JOURNAL OF FOOD BIOCHEMISTRY, Issue 1 2009
WENTAO LIU
ABSTRACT Pepsin-solubilized collagen prepared from the scales of snakehead (Ophiocephalus argus) was separated into two fractions, major and minor, by NaCl precipitation. The results of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), amino acid composition, and secondary structure showed that the major collagen was typical type I collagen; in contrast, the minor collagen might be classified as type V collagen from the SDS-PAGE patterns and precipitation properties by NaCl. A sharp decrease in solubility of type I collagen was observed at the NaCl concentration of 40 g/L. The maximum and the minimum solubilities of collagen were observed at pH 3 and 8, respectively. Peptide maps of type I collagen digested by trypsin and V8 protease were different from those of calfskin and fish skin collagens. The imino acid content of type I collagen was lower than those of mammalian collagens and so did its denaturation temperature that was 30.3C obtained by viscosity measurement. PRACTICAL APPLICATIONS Collagen has been widely utilized as a material for foods, cosmetics, and pharmaceuticals. However, the use of collagen-derived products from land animals (e.g., bovine and pig) has been called into question because of foot-and-mouth disease crisis etc. Aquatic animal offals, which are readily available and inexpensive, seem to be safe sources for extraction of collagen. This work reports on preparation and characterization of collagen from snakehead scales, which will have potential in supplementing the skins and bones of land animals as an important collagen resource for use in functional food, biomedical, and cosmetic industries. [source]

PREPARATION AND CHARACTERIZATION OF MODIFIED WHEAT GLUTEN BY ENZYMATIC HYDROLYSIS-ULTRAFILTRATION

JOURNAL OF FOOD BIOCHEMISTRY, Issue 3 2008
JIN-SHUI WANG
ABSTRACT The present work was aimed to investigate the characteristics of the modified wheat gluten by enzymatic hydrolysis followed ultrafiltration membrane fractionation. An 8% aqueous dispersion of wheat gluten was hydrolyzed by papain, and then subjected to ultrafiltration membrane for fractionation. The molecular mass of the peptides released during enzymatic hydrolysis of gluten was in the range of 5,000,15,000 D according to gel permeation chromatography profiles. The resultant hydrolysate (retentate fraction) after membrane fractionation produced the desired products with a protein yield of about 89%. The modified glutens had higher surface hydrophobicity compared with the original gluten. Moreover, the modified gluten protein had superior solubility to the original gluten in pH 3,10. The enhanced foaming capacity in the pH ranges studied had been found in the modified gluten. The improved functional properties of the modified gluten were related to the well-balanced distribution of hydrophilic and hydrophobic domains. The modified gluten was rich in glutamic acid and proline. PRACTICAL APPLICATIONS Gluten is an economically important byproduct during processing of wheat starch. The expanded utilization of gluten in food and nonfood applications had been limited for lack of desirable functional properties. To extend the range of available functional properties it needs to be investigated further. The limited enzymatic hydrolysis and membrane ultrafiltration had been extensively studied and had been shown to be very effective for improving the functional properties of the proteins. In this present study, wheat gluten was modified by enzymatic hydrolysis , membrane ultrafiltration fractionation. This method was proved to be an efficient way to modify wheat gluten protein. The functional properties of the modified glutens were significantly improved compared to the original gluten. It is expected that the modified gluten with enhanced functional properties could be used in a wide range of foods as new components to enhance their nutritional value and functional properties in food processing. [source]

SIMPLE METHOD FOR RNA PREPARATION FROM CYANOBACTERIA,

JOURNAL OF PHYCOLOGY, Issue 5 2006
Byung-Hyuk Kim
A simple and rapid method is presented for the preparation of RNA from various cyanobacteria. Unlike other methods that require a lysis solution, lysozymes, or proteinase K, the proposed method, called the bead,phenol,chloroform (BPC) method, uses silica/zirconia beads, phenol, and chloroform to break the cells and extract RNA more efficiently. Experiments confirm that the BPC method can successfully isolate total RNA from various cyanobacterial strains without DNA contamination, and the extracted RNA samples have a relatively high purity, concentration, and yield. Furthermore, the BPC method is more rapid, simple, and economical when compared with previously reported methods. [source]

DEVELOPMENT OF SAMPLE PREPARATION, PRESENTATION PROCEDURE AND SENSORY DESCRIPTIVE ANALYSIS OF GREEN TEA

JOURNAL OF SENSORY STUDIES, Issue 4 2008
SOH MIN LEE
ABSTRACT Although the infusing condition of green tea is critical in determining green tea quality, the green tea industries lack a validated standardized tea preparation procedure. The objectives were (1) to develop an effective sample preparation and presentation procedure to conduct an objective sensory analysis; and (2) to elucidate the effects of green tea types and infusing conditions on the sensory characteristics of green tea. The optimum infusing times for green tea at two temperatures (60 and 80C) were determined using the just-about-right scale evaluated by consumers. Then, a descriptive analysis was conducted. The panelists developed 16 descriptors, and determined the reference samples and the tasting procedure. The optimum infusing time,temperature combinations are approximately 3 min at 60C or 1 min at 80C. The intensity of fermented-like flavor increased, but cut grass and floral flavor decreased with the lower-graded tea leaf. Samples infused at 60C,3 min were sweeter but less bitter than samples at 80C,1 min. PRACTICAL APPLICATIONS The sample preparation method and evaluating conditions developed in this study have been validated using both analytical and consumer studies. The protocols showed to be powerful in discriminating the sensory characteristics between the samples when conducting objective sensory analyses. The sensory lexicons and standards established should be useful to researchers and product developers who are working with flavors of green tea. Additionally, the sample preparation method and evaluation procedure introduced in this study are relatively straightforward, thus, making it possible for the general sensory scientist group to use an effective standardized method when conducting objective sensory analyses of green tea. [source]

COOKING BEHAVIOR OF RICE AND BLACK GRAM IN THE PREPARATION OF IDLI, A TRADITIONAL FERMENTED PRODUCT OF INDIAN ORIGIN, BY VISCOGRAPHY

JOURNAL OF TEXTURE STUDIES, Issue 1 2009
BONG KYUNG KOH
ABSTRACT Pasting profile of coarse rice, fine rice as well as black gram was carried out individually, in combination, in flour as well as in batter form, before and after fermentation by Brabender Viscoamylograph. Lowest gelatinization temperature was seen in black gram among the three commodities studied. Coarse rice registered a peak viscosity (PV) of 1,300 BU, fine rice 1,030 BU and black gram 1,080 BU. Cold paste viscosity (CPV) was highest in fine rice, lowest in black gram and intermediate in coarse rice. Breakdown (BD) was least in fine rice, highest in coarse rice and black gram lay in between. Values of total setback indicated the strong reason for use of coarse rice in parboiling as well as in idli and dosa preparations. Physical combination of black gram, with fine as well as coarse rice, reduced PV on an average to an extent of 26,30%. CPV was highest in fine rice and black gram combination compared with that of coarse rice and black gram. BD was high in the physical mix of coarse rice and black gram. In comparison with physical mix of fine rice and black gram, in the batter form before fermentation, the PV and CPV reduced by 23 and 34%, respectively, but there was no BD in this mix, indicating restricted swelling behavior in the batter before fermentation. Almost all viscographic parameters reduced before fermentation in coarse rice and black gram compared with their physical combination. Highest relative BD (BDr) was noticed in the pasting profile of black gram alone, probably because of the presence of mucilaginous principle. BDr values increased in batter form to various extents, before and after fermentation, compared with physical combination of rice and black gram. After fermentation, in coarse rice and black gram, the BDr value was low compared with that in fine rice and black gram. PRACTICAL APPLICATIONS Fermented products are commonly ingested in India, especially in the southern states. Nowadays, batter is sold in public for the sake of convenience, as it is a common breakfast preparation. The practice is to use coarse rice for the preparation of idli, a steamed fermented product. It is generally not known how the rice behaves before and after fermentation while cooking. Hence, this work was planned, and results indicated the scientific basis for the usage of coarse rice in the preparation of rice products. The behavior of batter prepared from fine rice has also been described, although it is not an economically viable option. [source]

TESTING ASSUMPTIONS OF NEUTRON ACTIVATION ANALYSIS: COMMUNITIES, WORKSHOPS AND PASTE PREPARATION IN YUCATAN, MEXICO,

ARCHAEOMETRY, Issue 2 2000
D. E. ARNOLD
Contemporary pottery and raw materials (N= 170) from three workshops in Ticul, Yucatán, were analysed by neutron activation to test the hypothesis that individual workshops that used their own clay sources could be identified by their pottery. Although the data failed to confirm the hypothesis, the results reinforced previous conclusions about the relationship of local communities of potters to the chemical patterning of pottery made in these communities. [source]

RESPONSIBILITY FOR CONTROL; ETHICS OF PATIENT PREPARATION FOR SELF-MANAGEMENT OF CHRONIC DISEASE

BIOETHICS, Issue 5 2007
BARBARA K. REDMAN
ABSTRACT Patient self-management (SM) of chronic disease is an evolving movement, with some forms documented as yielding important outcomes. Potential benefits from proper preparation and maintenance of patient SM skills include quality care tailored to the patient's preferences and life goals, and increase in skills in problem solving, confidence and success, generalizable to other parts of the patient's life. Four central ethical issues can be identified: 1) insufficient patient/family access to preparation that will optimize their competence to SM without harm to themselves, 2) lack of acknowledgement that an ethos of patient empowerment can mask transfer of responsibility beyond patient/family competency to handle that responsibility, 3) prevailing assumptions that preparation for SM cannot result in harm and that its main purpose is to deliver physician instructions, and 4) lack of standards for patient selection, which has the potential to exclude individuals who could benefit from learning to SM. Technology assessment offers one framework through which to examine available data about efficacy of patient SM and to answer the central question of what conditions must be put in place to optimize the benefits of SM while assuring that potential harms are controlled. [source]

s -CARBOXYMETHYLCYSTEINE INHIBITS CARBACHOL-INDUCED CONSTRICTION OF EPITHELIUM-DENUDED RAT AND HUMAN AIRWAY PREPARATIONS

CLINICAL AND EXPERIMENTAL PHARMACOLOGY AND PHYSIOLOGY, Issue 5-6 2008
Dragan Pavlovic
SUMMARY 1The effects of s-carboxymethyl-l-cysteine (S-CMC), either administered orally to rats or incubated with tissue preparations from rats and humans, on isometric contractions of tracheal smooth muscle were investigated in the present study using an improved in vitro model of tracheal tube or ring preparations. The involvement of the tracheal epithelium in the observed effects was also investigated. 2The experimental model permitted selective perfusion of the airway tube, luminal-IN or serosal,OUT, and measurement of airway smooth muscle contraction or relaxation in preparations with (+) or without (,) epithelium (Ep), excluding direct effects of airway mucus. 3We found that oral pretreatment of rats with S-CMC (mixed with water; 200 mg/kg per day for 2 weeks), but not short pre-incubation of preparations in vitro (10,3 mol/L S-CMC for 1 h), diminished the sensitivity of ,Ep preparations to carbachol compared with controls (EC50 (,log10 mol/L) values: 5.5 ± 0.1 vs 5.8 ± 0.1, respectively, for IN perfusion (P < 0.005); 5.6 ± 0.1 vs 5.9 ± 0.1, respectively, for OUT perfusion (P < 0.005)), whereas the sensitivity of preparations to aminophylline was not affected. Normal sensitivity to carbachol stimulation was re-established if preparations were pre-incubated with capsaicin. 4It was also found that longer pre-incubation (4 h) of ring-preparations of human bronchus with S-CMC (10,5 mol/L) in vitro resulted in a diminished response to carbachol stimulation. 5In conclusion, S-CMC had small inhibitory effects on the sensitivity of rat and human airway smooth muscle to carbachol, particularly in endothelium-denuded preparations. Whether the epithelium was responding to S-CMC by producing some contracting factor(s) requires further investigation. [source]

Data Preparation for Real-time High Quality Rendering of Complex Models

COMPUTER GRAPHICS FORUM, Issue 3 2006
Reinhard Klein
The capability of current 3D acquisition systems to digitize the geometry reflection behaviour of objects as well as the sophisticated application of CAD techniques lead to rapidly growing digital models which pose new challenges for interaction and visualization. Due to the sheer size of the geometry as well as the texture and reflection data which are often in the range of several gigabytes, efficient techniques for analyzing, compressing and rendering are needed. In this talk I will present some of the research we did in our graphics group over the past years motivated by industrial partners in order to automate the data preparation step and allow for real-time high quality rendering e.g. in the context of VR-applications. Strength and limitations of the different techniques will be discussed and future challenges will be identified. The presentation will go along with live demonstrations. [source]

Preparation, structure and photoluminescence properties of SiO2,coated ZnS nanowires

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 10 2010
Changhyun Jin
Abstract It is essential to passivate one-dimensional (1D) nanostructures with insulating materials to avoid crosstalking as well as to protect them from contamination and oxidation. The structure and influence of thermal annealing on the photoluminescence properties of ZnS-core/SiO2 -shell nanowires synthesized by the thermal evaporation of ZnS powders followed by the sputter deposition of SiO2 were investigated. Transmission electron microscopy and X-ray diffraction analyses revealed that the cores and shells of the core-shell nanowires were single crystal zinc blende-type ZnO and amorphous SiO2, respectively. Photoluminescence (PL) measurement showed that the core-shell nanowires had a green emission band centered at around 525 nm with a shoulder at around 385 nm. The PL emission of the core-shell nanowires was enhanced in intensity by annealing in an oxidative atmosphere and further enhanced by subsequently annealing in a reducing atmosphere. Also the origin of the enhancement of the green emission by annealing is discussed based on the energy-dispersive X-ray spectroscopy analysis results. (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation of shuttle-like Sb2S3 nanorod-bundles via a solvothermal approach under alkaline condition

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2010
Ling Zhang
Abstract Uniform shuttle-like Sb2S3 nanorod-bundles were synthesized via a polyvinylpyrrolidone (PVP) assisted solvothermal approach under alkaline condition, using antimony chloride (SbCl3) and thiourea (CH4N2S, Tu) as the starting materials in ethanol. The phase structure, composition and morphology of the product were characterized by means of X-ray diffraction (XRD), energy dispersive X-ray spectrometry (EDS), transmission electron microscopy (TEM), and high-resolution transmission electron microscopy (HRTEM). XRD and EDS results confirm that the synthesized Sb2S3 nanorod-bundles have an orthorhombic structure and an atomic ratio of 3:2 for S:Sb. TEM and HRTEM results show that the shuttle-like Sb2S3 bundles are composed of nanorods with a size distribution of 20-40 nm and growing along c-axis. Furthermore, experiments under different reaction conditions were carried out and the mechanism for the growth of nanorod-bundles was discussed (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation, physicochemical and third order nonlinear optical properties of bis(tetrabutylammonium)bis(2-thioxo-1,3-dithiole-4,5-dithiolato)mercurate(II)

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2009
X. Q. Wang
Abstract Bis(tetrabutylammonium)bis(2-thioxo-1,3-dithiole-4,5-dithiolato)mercurate(II) was prepared and characterized by elemental analyses, electronic absorption, infrared and X-ray powder diffraction spectroscopy. The specific heat of the crystal was measured to be 1878.2 J.mol,1K,1 at 300 K. The thermal decomposition process was investigated by means of thermogravimetric analysis and differential thermal analysis measurements in air together with infrared and X-ray powder diffraction spectra. The third-order nonlinear optical properties at 800 nm were measured by femtosecond optical Kerr gate technique by using CS2 as reference. The third-order optical susceptibility of its acetone solution at the concentration of 9.27 × 10,4 M was obtained to be 2.53 × 10,14 esu. The second-order hyperpolarizability was estimated to be 1.7 × 10,32 esu and the response time was about 226 fs. The third order nonlinear optical properties at 532 nm were investigated by using the Z-scan technique with 20 ps. It exhibited self-focusing effect and saturable absorption. The second molecular hyperpolarizability was estimated to be 8.4 × 10,32 esu. (© 2009 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation of GaN crystals by heating a Li3N-added Ga melt in Na vapor and their photoluminescence

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 1 2007
Takahiro Yamada
Abstract GaN crystals were prepared by heating a Ga melt with 1 at% Li3N against Ga at 750 °C in Na vapor under N2 pressures of 0.4,1.0 MPa. The GaN crystals grown at 1.0 MPa of N2 were colorless and transparent prismatic, having a size of approximately 0.7 mm in length. A secondary ion mass spectrometry (SIMS) showed the contaminant of lithium in the obtained crystals. A large broad yellow band emission peak of 2.28 eV was observed at room temperature in the photoluminescence spectrum in addition to the near band emission peak of GaN at 3.39 eV and a small broad satellite emission at 3.24 eV. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation and characterization of ZnO nanofibers by electrospinning

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 5 2006
R. Siddheswaran
Abstract Electrospun ZnO nanofibers were obtained by calcinating PVA/Zinc Acetate composite fibers at various temperatures. Atomic Force Microscopy (AFM) revealed that the ZnO fibers have diameters in the range of 100-200 nm. The fibers were characterized by FT- IR, TGA-DTA, and XRD studies. The XRD results showed that the crystal structure and the morphology of the fibers were largely dependent on the calcination temperature (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation of undoped and indium doped ZnO thin films by pulsed laser deposition method

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 12 2005
B. Kotlyarchuk
Abstract An original modification of the standard Pulse Laser Deposition (PLD) method for preparing both undoped and indium doped zinc oxide (ZnO:In) thin films at low substrate temperature is proposed. This preparation method does not demand any further post-deposition annealing treatment of the grown films. The developed method allows to grow thin films at low substrate temperature that prevents them from the considerable loss of their intrinsic electrical and optical properties. The influence of deposition parameters on the electrical and optical parameters of the undoped and the indium doped ZnO thin films is also analysed. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation and characterization of powders and crystals of Vn-xTixO2n-1 Magneli oxides

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 10-11 2005
D. Calestani
Abstract Vn-xTixO2n-1 Magnéli phases have been synthesized under vacuum in powder form (n = 4, 0 , x , 0.4) and crystals (n = 4 and 5, x = 0.5 and 1.4, respectively), grown by chemical vapour transport in closed ampoules. TeCl4 and NH4Cl were used as transporting agents. Needle-shaped crystals as long as 200-300 micrometers or 2-3 mm were obtained when in presence of NH4Cl or TeCl4, respectively. The powder and crystal structures were examined by X-ray diffraction and the transport and magnetic characteristics were measured.. The powders resulted to be single-phase and the relevant composition was assumed to be equal to the nominal one. The overall stoichiometry of compounds, n, was determined from single crystal X-ray diffraction data. The Ti content, x, was deduced from the elementary cell volume, by applying the Végard law. Crystals were mainly untwinned and of good quality. The elementary cell of both, powders and crystals, was triclinic (P-1) and did not change with doping. DC electrical resistivity of the crystals was measured in a four-points (van der Pauw) configuration. DC magnetic susceptibility of the powders was measured in a SQUID magnetometer. The Ti doping was found to progressively smooth and finally to suppress the magnetic transitions occurring in the V4O7. The metal-insulator transitions observed in V4O7 and V5O9, at around 235 and 125 K respectively, were not observed in the doped crystals, thus indicating some significant change of the electronic structure of the V oxides. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Preparation and characterization of electrodeposited indium selenide thin films

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 6 2005
S. Gopal
Abstract Indium Selenide (InSe) thin films were deposited from a mixture of Indium chloride and selenium dioxide in aqueous solution by electrodeposition technique on Indium Tin oxide coated glass substrates. The effects of the parameters during deposition such as current density, deposition potential versus saturated calomel electrode, pH value and concentration of source material were studied. X-ray diffraction studies were carried out on the films to analyze the microstructure using an x-ray diffractometer and were examined by RAMAN spectroscopy. The Raman peak position did not change much with chemical concentrations. Raman scattering due to the (LO) phonon was observed at 211 cm,1. Optical absorption studies were performed with a double beam ultra violet-visible ,NIR spectrophotometer in the wavelength 300,1100 nm. The surface morphology of the layer was examined using a scanning electron micrograph. The composition of the films was studied using an Energy Dispersive Analysis by X-Rays (EDAX). [source]

Preparation and investigation of (CuInSe2)x(2ZnSe)1-x and (CuInTe2)x(2ZnTe)1-x solid solution crystals

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 4 2004
I. V. Bodnar
Abstract The (CuInSe2)x(2ZnSe)1-x and (CuInTe2)x(2ZnTe)1-x solid solution crystals prepared by Bridgman method and chemical vapor transport have been studied. The nature of the crystalline phases, the local structure homogeneity and composition of these materials have been investigated by X-ray diffraction (XRD) and Electron Probe Microanalysis (EPMA) methods. The analysis revealed the presence of chalcopyrite-sphalerite phase transition between 0.6 , X , 0.7. Lattice constants, value of , position parameter and bond length between atoms were also calculated. It was found that the lattice parameters exhibit a linear dependence versus composition. The transmission spectra of solid solution crystals in the region of the main absorption edge were studied. It was established that the optical band gap of these materials changes non-linearly with the X composition. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

PbS crystals with clover-like structure: Preparation, characterization, optical properties and influencing factors

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 3 2004
Yonghong Ni
Abstract A new and simple route to synthesize Lead sulfide (PbS) crystals with the clover-like structure was described in the current paper. PbS was prepared in a simple aqueous solution employing (CH3COO)2Pb and thiourea as the initial materials under 130 W microwave irradiation. No any surfactant or template including organic polyamines with N-chelation property was needed. The phase and composition of the product were identified by X-ray powder diffraction (XRD) and X-ray photoelectron spectra (XPS). TEM observation showed that the product with the six-petal flower-shaped structures was obtained, but SEM observation confirmed the clover-like structure of the product; and the six-petal flowers were formed via the overlap of two clovers revolved 60° around the center of the flower. Some factors affected the shape of the final product were studied and the optical properties of PbS crystals with the clover-like structure were measured. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Studies on the growth and optical characterization of dysprosium gadolinium oxalate single crystals

CRYSTAL RESEARCH AND TECHNOLOGY, Issue 2 2004
A. Elizebeth
Abstract Preparation and optical characterization of dysprosium gadolinium oxalate (DGO) single crystal is reported. The crystals were grown using silica gel technique, by the controlled reaction of rare earth nitrates with oxalic acid. Crystals were characterized using X-ray powder diffraction, optical absorption and fluorescence studies. Radiative transition probability, fluorescence branching ratio and radiative lifetime of Dy3+ in the crystal are evaluated by the parameterization of the absorption spectrum by the Judd-Ofelt theory. The recorded fluorescence spectrum showed two well resolved peaks at 480 nm and 571 nm and are assigned to the transitions from 4F9/2 , 6H15/2 and 6H13/2 of Dy3+. Stimulated emission crossection and optical gain of these transitions are also evaluated. (© 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Cosmeceuticals Containing Herbs: Fact, Fiction, and Future

DERMATOLOGIC SURGERY, Issue 2005
Carl Thornfeldt MD
Background. Modern medicine is rooted in ethnobotanical traditions using indigenous flora to treat symptoms of human diseases or to improve specific aspects of the body condition. Herbal medicine is now used by over half of the American population. Yet the American medical community generally lacks knowledge of the function, metabolism, interaction, adverse reactions, and preparation of herbal products. Objective. Because over 60 botanicals are marketed in cosmeceutical formulations, dermatologists need to obtain working knowledge of the major botanicals. The preparation, traditional uses, mechanisms of action, human clinical data, adverse reactions, and interactions all impact herbal efficacy and are discussed below. Method. English-language medical journal and symposium searches. Results. The most important botanicals pertaining to dermatologic uses, such as cosmeceuticals, include teas, soy, pomegranate, date, grape seed, Pycnogenol, horse chestnut, German chamomile, curcumin, comfrey, allantoin, and aloe. All are documented to treat dermatologic conditions. Only green and black tea, soy, pomegranate, and date have published clinical trials for the treatment of parameters of extrinsic aging. Conclusions. Preparation of botanical-based cosmeceuticals is complex. Very few of these products are supported by evidence-based science. CARL THORNFELDT, MD, FAAD, HAS INDICATED NO SIGNIFICANT INTEREST WITH COMMERCIAL SUPPORTERS. [source]

Preparation of thyroid FNA material for routine cytology and BRAF testing: A validation study

DIAGNOSTIC CYTOPATHOLOGY, Issue 3 2010
Giancarlo Troncone M.D., Ph.D.
Abstract V600E BRAF mutation is emerging as an independent marker of papillary thyroid carcinoma aggressive behavior. Papillary thyroid carcinomas harboring this mutation should be extensively resected. However, this requires an unquestionable cytological diagnosis of malignancy. Thus, cytological specimens should be properly handled to provide both morphological and molecular information. Here, we assessed whether our method of preparation of fine-needle aspiration material is suitable for both tests. A series of 128, routinely performed, fine-needle aspirations was analyzed. Each nodule was punctured three times. A representative Diff-Quik smear prepared from the first two passages was evaluated onsite. When microscopy was diagnostic (n = 44), the third needle pass was dedicated to harvest material for BRAF testing; in the remaining cases (n = 84), additional direct smears for cytology were prepared and the remaining material in the needle plus the needle rinsing was collected for BRAF testing. Cellularity was adequate in 126/128 (98%) cases. Cytological diagnoses were inadequate (2%), benign (85%), follicular lesion of undetermined significance (5%), follicular neoplasms (2%), suspicious for malignancy (2%), and malignant (4%). Higher average of extracted DNA concentration was observed in the dedicated pass group (25.9 vs 7.95 ng/,l). However, the rate of successful exon 15 BRAF amplification was similar with (43/44; 97.7%) or without (79/84; 94%) the dedicated pass. Thus, our protocol is suitable for both tests. Whenever necessary BRAF testing may also be performed on the residual samples of thyroid nodules, without interfering with routine cytology. Diagn. Cytopathol. 2010. © 2009 Wiley-Liss, Inc. [source]

Preparation and Characterization of a Tin Pentacyanonitrosylferrate-Modified Carbon Ceramic Electrode: Application to Electrocatalytic Oxidation and Amperometric Detection of L -Cysteine

ELECTROANALYSIS, Issue 7 2009
H. Razmi
Abstract The sol-gel technique was used to construct tin pentacyanonitrosylferrate (SnPCNF) modified composite carbon ceramic electrode (CCE). This involves two steps: construction of CCE containing metallic Sn powder and then electrochemical creating of SnPCNF on the surface of CCE. The SnPCNF modified CCE (SnPCNFlCCE) was characterized by energy-dispersive X-ray (EDX), FTIR and cyclic voltammetry (CV) techniques. The SnPCNF film showed electrocatalytic activity toward the oxidation of L -cysteine. A linear calibration plot was obtained over the L -cysteine concentration range 1,51,,M using chronoamperometry. L -cysteine was determined amperometrically at the surface of this modified electrode. The detection limit (for a signal to noise of 3) and sensitivity were found to be 0.62,,M and 126,,A/mM, respectively. [source]

Preparation, Electrochemistry, and Electrocatalytic Activity of Lead Pentacyanonitrosylferrate Film Immobilized on Carbon Ceramic Electrode

ELECTROANALYSIS, Issue 21 2008
H. Razmi
Abstract Lead pentacyanonitrosylferrate (PbPCNF), a new Prussian blue analog, was immobilized on the surface of a carbon ceramic electrode (CCE) prepared by sol-gel method. The immobilization process consists of adding a certain amount of metallic lead to the electrode matrix before gelation, and chemical derivatization of Pb on the electrode surface to a PbPCNF solid film by immersing the electrode in a solution of sodium pentacyanonitrosylferrate (PCNF). The composition of the synthesized PbPCNF was characterized by FTIR, scanning electron microscopy (SEM), and energy-dispersive X-ray (EDX) techniques. The resulting modified electrode showed electroactivity at two redox centers. The electrochemical behavior of the PbPCNF modified carbon ceramic electrode (PbPCNF|CCE) was studied by cyclic voltammetry. Under optimized conditions the peak-to-peak separation is only 39,mV, indicative of a surface reaction. Ion effects of the supporting electrolyte suggest that cations have a considerable effect on the electrochemical behavior of the modified electrode. The transfer coefficient (,) and the charge transfer rate constant at the modifying film|electrode interface (ks) were calculated. The electrocatalytic activity of the modified electrode toward the electro-reduction of peroxodisulfate was studied in details. [source]

Paste Electrode Based on Short Single-Walled Carbon Nanotubes and Room Temperature Ionic Liquid: Preparation, Characterization and Application in DNA Detection

ELECTROANALYSIS, Issue 12 2008
Xuzhi Zhang
Abstract A paste electrode (SWNT&RTIL PE) has been prepared using carboxylic group-functionalized short single-walled carbon nanotubes (SWNTs) mixed with 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF6, one kind of room temperature ionic liquid, RTIL). Its electrochemical behavior was investigated by cyclic voltammetry and electrochemical impedance spectroscopy in comparison with the paste electrode using mineral oil as a binder. Results highlighted the advantages of the paste electrode: not only higher conductivity, but also lower potential separation (,Ep), higher peak current (ip) and better reversibility towards dopamine (DA), methylene blue (MB) and K3[Fe(CN)6]. The SWNT&RTIL PE could be used to detect the number of guanine bases and adenine bases contents in per mol oligonucleotides according to the current response in the range of 0.05,2.0,nM. Based on the current response of guanine bases, oligonucleotides could be detected sensitively in the B,R buffer solution with a detection limit of 9.9,pM. The heterogeneous electron transfer rate constant (ks) of guanine bases contents in the oligonucleotides was investigated and its value was 0.90,s,1. In essence the SWNT&RTIL PE showed high sensitivity, reliability, stability and reproducibility for the detection of DNA. [source]

Preparation of Novel Arrays Silver Nanoparticles Modified Polyrutin Coat-Paraffin-Impregnated Graphite Electrode for Tyrosine and Tryptophan's Oxidation

ELECTROANALYSIS, Issue 8 2008
Guan-Ping Jin
Abstract A novel array silver nanoparticles and Rutin complex film modified paraffin-impregnated graphite electrode was proposed in this work (denoted as Ag/Rutin/WGE). The characteristics were investigated by the field emission scanning electron microscopy (FE-SEM), infrared spectra (IR), UV-visible (UV), X-ray photoelectron spectroscopy (XPS) and electrochemical techniques. Silver ions were gradually chelated by polyrutin film at 4,-oxo-5,-OH and 5-OH-4-oxo sites accompanying adsorption, then. Silver nanoparticles were highly-dispersed electrodeposited on polyrutin film. The electrochemical behaviors of tyrosine (Tyr) and tryptophan (Trp) were studied by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques. The Ag/Rutin/WGE electrode shows overlapping catalysis for the oxidation of Tyr and Trp. The linear response of Tyr and Trp were 0.3,10.0 and 0.7,70.0,,M with detection limit of 0.07 and 0.1,,M in a signal-to-noise ratio of 3. [source]

Preparation of Nanogapped Gold Nanoparticle Array for DNA Detection

ELECTROANALYSIS, Issue 4 2008
Shiho Tokonami
Abstract A novel DNA detection technique using a gold nanoparticle array film electrode has been reported here. The gold nanoparticles molecularly linked with binder molecule (1,10-decanedithiol) were separated 1.3,nm from each other, and the DNA conductivity change from single to double strand was measured by monitoring a voltage drop across the particles, between which a probe of a 12-mer oligonucleotide was immobilized. In adding a complementary oligonucleotide on the nanoparticle film chip, an immediate decrease in the film resistance (ca. 1.4 ,) due to a hybridization event occurred in a reproducible manner with this simple setup. In the paper, we have an interest in the primary sensing properties; effect of the film resistance on the sensor response, dependence of the resistance change on the DNA concentration, and the performance of the system for DNA detection including single nucleotide polymorphisms were described. [source]

Conductive Organic Complex Salt TTF-TCNQ as a Mediator for Biosensors.

ELECTROANALYSIS, Issue 24 2007
An Overview
Abstract Preparation and application of a conductive organic salt complex of tetrathiafulvalene-tetracyanoquinodimethane (TTF-TCNQ) for analytical bioelectrochemistry as a mediator is overviewed in this work. The third-generation biosensors based on this charge transfer salt are very promising for biosensors applied in vivo. Such mediated biosensors have been studied mainly for glucose determination, but at present other substrates are being applied in this system more and more often. [source]

Electrochemical Preparation of Poly(Malachite Green) Film Modified Nafion-Coated Glassy Carbon Electrode and Its Electrocatalytic Behavior Towards NADH, Dopamine and Ascorbic Acid

ELECTROANALYSIS, Issue 14 2007
Shen-Ming Chen
Abstract Poly(malachite green) film modified Nafion-coated glassy carbon electrodes have been prepared by potentiodynamic cycling in malachite green solution. The pH of polymerisation solution has only minor effect on film formation. Electrochemical quartz crystal microbalance (EQCM) was used to monitor the growth of the poly(malachite green) film. Cyclic voltammogram of the poly(malachite green) film shows a redox couple with well-defined peaks. The redox response of the modified electrode was found to be depending on the pH of the contacting solution. The peak potentials were shifted to a less positive region with increasing pH and the dependence of the peak potential was found to be 56,mV per pH unit. The electrocatalytic behavior of poly(malachite green) film modified Nafion-coated glassy carbon electrodes was tested towards oxidation of NADH, dopamine, and ascorbic acid. The oxidation of dopamine and ascorbic acid occurred at less positive potential on poly(malachite green) film compared to bare glassy carbon electrode. In the case of NADH, the overpotential was reduced substantially on modified electrode. Finally, the feasibility of utilizing poly(malachite green) film electrode in analytical estimation of ascorbic acid was demonstrated in flow injection analysis. [source]