3,686 research outputs found

    Binaural beats or 432 Hz music? which method is more effective for reducing preoperative dental anxiety?

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    The aim of this prospective clinical study was to investigate the effectiveness of binaural beats and music at a frequency of 432 Hz and compare which method is more effective for reducing preoperative dental anxiety in impacted third molar surgery. Ninety patients were randomly selected to the binaural beats group, music group and control group. Visual analog scale used to evaluate dental anxiety before the local anesthesia in the first measurement. Local anesthesia was applied to the all patients. Patients in the music group listened to 432 Hz tuned music using earphones for 10 minutes. Patients in the binaural beats group listened to binaural beats using earphones (for the right ear, 220 Hz and for the left ear 210 Hz) for 10 minutes. No special treatment was applied to the patients in control group. In the second measurement, dental anxiety was measured again in all three groups. For analysis of differences between three groups was used One way Anova and Kruskal Wallis test. Twenty seven male and 53 female patients included the study. In the first measurement, the same level of anxiety was recorded in all three groups. (p=0.811) There was a significant decrease in anxiety in both the binaural beats and music group in the second measurement. (p<0.001). Binaural beats and 432 Hz tuned music are a valid non pharmacological adjuvant to reduce dental anxiety in impacted third molar surgery. They have a positive effect to reduce the dental anxiety

    Interfacial Reactions of Ozone with Surfactant Protein B in a Model Lung Surfactant System

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    Oxidative stresses from irritants such as hydrogen peroxide and ozone (O_3) can cause dysfunction of the pulmonary surfactant (PS) layer in the human lung, resulting in chronic diseases of the respiratory tract. For identification of structural changes of pulmonary surfactant protein B (SP-B) due to the heterogeneous reaction with O_3, field-induced droplet ionization (FIDI) mass spectrometry has been utilized. FIDI is a soft ionization method in which ions are extracted from the surface of microliter-volume droplets. We report structurally specific oxidative changes of SP-B_(1−25) (a shortened version of human SP-B) at the air−liquid interface. We also present studies of the interfacial oxidation of SP-B_(1−25) in a nonionizable 1-palmitoyl-2-oleoyl-sn-glycerol (POG) surfactant layer as a model PS system, where competitive oxidation of the two components is observed. Our results indicate that the heterogeneous reaction of SP-B_(1−25) at the interface is quite different from that in the solution phase. In comparison with the nearly complete homogeneous oxidation of SP-B_(1−25), only a subset of the amino acids known to react with ozone are oxidized by direct ozonolysis in the hydrophobic interfacial environment, both with and without the lipid surfactant layer. Combining these experimental observations with the results of molecular dynamics simulations provides an improved understanding of the interfacial structure and chemistry of a model lung surfactant system subjected to oxidative stress

    Quantum thermodynamics at critical points during melting and solidification processes

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    We systematically explore and show the existence of finite-temperature continuous quantum phase transition (CTQPT) at a critical point, namely, during solidification or melting such that the first-order thermal phase transition is a special case within CTQPT. Infact, CTQPT is related to chemical reaction where quantum fluctuation (due to wavefunction transformation) is caused by thermal energy and it can occur maximally for temperatures much higher than zero Kelvin. To extract the quantity related to CTQPT, we use the ionization energy theory and the energy-level spacing renormalization group method to derive the energy-level spacing entropy, renormalized Bose-Einstein distribution and the time-dependent specific heat capacity. This work unambiguously shows that the quantum phase transition applies for any finite temperatures.Comment: To be published in Indian Journal of Physics (Kolkata

    Resuscitation and quantification of stressed Escherichia coli K12 NCTC8797 in water samples

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    The aim of this study was to investigate the impact on numbers of using different media for the enumeration of Escherichia coli subjected to stress, and to evaluate the use of different resuscitation methods on bacterial numbers. E. coli was subjected to heat stress by exposure to 55 °C for 1 h or to light-induced oxidative stress by exposure to artificial light for up to 8 h in the presence of methylene blue. In both cases, the bacterial counts on selective media were below the limits of detection whereas on non-selective media colonies were still produced. After resuscitation in non-selective media, using a multi-well MPN resuscitation method or resuscitation on membrane filters, the bacterial counts on selective media matched those on non-selective media. Heat and light stress can affect the ability of E. coli to grow on selective media essential for the enumeration as indicator bacteria. A resuscitation method is essential for the recovery of these stressed bacteria in order to avoid underestimation of indicator bacteria numbers in water. There was no difference in resuscitation efficiency using the membrane filter and multi-well MPN methods. This study emphasises the need to use a resuscitation method if the numbers of indicator bacteria in water samples are not to be underestimated. False-negative results in the analysis of drinking water or natural bathing waters could have profound health effects

    Genetic Variation of Juvenile Wood Properties in a Loblolly Pine Diallel Test

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    The reduced rotation age for loblolly pine plantations has resulted in an increased percentage of juvenile wood. Juvenile wood has lower wood density, shorter tracheid length and higher lignin content than mature wood. The increased use of juvenile wood has reduced yields and increased pulping costs for the pulp and paper industry. If significant genetic variation in juvenile wood properties can be found, breeders may be able to improve juvenile wood properties to reduce pulping losses. Genetic variation in several wood quality traits of loblolly pine (Pinus taeda L.) was investigated for 14 full-sib families generated by a 6-parent half-diallel mating design. Wood samples of 12 mm increment cores were collected from 11-year-old trees from one test site. Earlywood and latewood of ring three (juvenile wood) and ring eight (transition wood) for each increment core were analyzed for alpha cellulose content (ACY), average fiber length (FLW), coarseness (COA), and lignin content (LIG). Ring three and ring eight had significant differences in ACY, FLW, and COA, but not for LIG. Latewood of both rings had higher ACY, FLW, and COA than earlywood. Transition wood had significantly higher ACY, FLW, and COA, but lower LIG than juvenile wood. Families differed significantly for ACY, FLW, and COA, but not for LIG. In general, additive genetic effects explained greater percentages of family variation than dominance genetic effects. Genetic variation increased from juvenile to transition wood. While weak individual and family heritabilities were found for ACY, FLW, and COA for juvenile wood, heritability estimates for transition wood were moderate, indicating the potential for improving these juvenile traits.Papers and abstracts from the 27th Southern Forest Tree Improvement Conference held at Oklahoma State University in Stillwater, Oklahoma on June 24-27, 2003

    Selective Area Growth of GaAs Nanowires and Microplatelet Arrays on Silicon by Hydride Vapor-Phase Epitaxy

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    In this work, we demonstrate the growth of vertically oriented GaAs nanowires (NWs) and microplatelets directly on a patterned SiO2/Si(111) substrate by hydride vapor-phase epitaxy (HVPE). Direct condensation of GaAs on Si was achieved through a critical surface preparation under an As-controlled atmosphere. GaAs NWs were grown along the ⟨111⟩B direction with a hexagonal cross section when the hole opening diameter (D) in the SiO2 mask was below 350 nm. Larger apertures (D ≥ 500 nm) resulted in uniform microplatelets. This study highlights the capability of HVPE for selective area growth of GaAs directly on Si and thus the potential of HVPE as a generic heterointegration process for III-V semiconductors on silicon.</p

    Implementation of 3 T Lactate-Edited 3D 1H MR Spectroscopic Imaging with Flyback Echo-Planar Readout for Gliomas Patients

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    The purpose of this study was to implement a new lactate-edited 3D 1H magnetic resonance spectroscopic imaging (MRSI) sequence at 3 T and demonstrate the feasibility of using this sequence for measuring lactate in patients with gliomas. A 3D PRESS MRSI sequence incorporating shortened, high bandwidth 180° pulses, new dual BASING lactate-editing pulses, high bandwidth very selective suppression (VSS) pulses and a flyback echo-planar readout was implemented at 3 T. Over-prescription factor of PRESS voxels was optimized using phantom to minimize chemical shift artifacts. The lactate-edited flyback sequence was compared with lactate-edited MRSI using conventional elliptical k-space sampling in a phantom and volunteers, and then applied to patients with gliomas. The results demonstrated the feasibility of detecting lactate within a short scan time of 9.5 min in both phantoms and patients. Over-prescription of voxels gave less chemical shift artifacts allowing detection of lactate on the majority of the selected volume. The normalized SNR of brain metabolites using the flyback encoding were comparable to the SNR of brain metabolites using conventional phase encoding MRSI. The specialized lactate-edited 3D MRSI sequence was able to detect lactate in brain tumor patients at 3 T. The implementation of this technique means that brain lactate can be evaluated in a routine clinical setting to study its potential as a marker for prognosis and response to therapy
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