Search

The purpose of this study is to propose an objective contrast-and-size detail (CSD) analysis for near infrared diffuse optical tomography (NIR DOT), of which the concept is derived from the subjective contrast detail (CD) analysis. We define a measure for numerical CSD analysis based on the resolution estimation of contrast and size. Following that, the contrast-and-size map of resolution can be calculated and displayed for each corresponding image in the map; furthermore, a CSD resolution curve can be plotted by calculating the average value of the projection corresponding to the physical quantity/axis (size or contrast). To provide some worked examples about the proposed CSD analysis evaluating the imaging performance of different reconstruction methods, Tikhonov regularization and edge-preserving regularization with different weighting functions were employed. Results suggested that using edge-preserving regularization with the generalized Lorentzian weighting function is the most attractive for the estimation of absorption-coefficient images. [ABSTRACT FROM AUTHOR]

The effect of magnesium supplementation on exercise performance remains controversial. In the present study, the effects of magnesium sulfate on exercise performance and blood glucose metabolism were examined. In order to provide a non-invasive measure of continuous exercise, we developed an auto-blood sampling system was coupled to a microdialysis analyzer to detect the dynamic changes in glucose metabolism in conscious and freely moving gerbils subjected to forced swimming. Gerbils were pretreated with saline or magnesium sulfate (90 mg kg−1, ip) 30 min before exercise. The duration times were significantly increased by 71% in the magnesium sulfate-treated groups ( p < 0.01) when compared with those in the control. Another group of gerbils were subjected to blood sampling assay. A catheter was implanted in the jugular vein of each gerbil for collecting blood samples by the computer-aided blood sampler. The basal levels of plasma glucose, lactate, and magnesium were 6,245 ± 662, 1,067 ± 309, and 590 ± 50 μM, respectively, with no significant difference between groups. Plasma glucose, lactate, and magnesium levels increased to 134 and 204%, 369 and 220%, and 155 and 422% of basal levels during swimming in both the control and magnesium sulfate-treated groups, respectively ( p < 0.05). Pretreatment with magnesium sulfate elevated glucose and magnesium levels to 175 and 302% of the basal levels ( p < 0.05), respectively, whereas pretreatment with magnesium sulfate reduced the lactate levels 150% of the basal level ( p < 0.05) during swimming. Furthermore, the magnesium levels increased to about 152–422% of basal levels during forced swimming and the recovery period ( p < 0.05). The present study demonstrates that magnesium sulfate improved the duration time of forced swimming exercise. In addition, magnesium raised glucose levels and attenuated lactate levels during forced swimming. These results indicate that positive effects of magnesium supplementation may contribute to the enhancement of exercise performance in athletes. [ABSTRACT FROM AUTHOR]

The oxidative dehydrogenation of cyclohexane was studied over Mg-V-O catalysts with different Mg/V atomic ratios. Catalysts were prepared via citric acid complexation and characterized by N2-adsorption, XRD, FT-IR, Raman spectroscopy, NH3-TPD and H2-TPR techniques. Among the pure magnesium vanadates, Mg3(VO4)2 has the isolated active sites, weakly basic surface and lower reducibility of the metal cations, and could be recognized as the catalytic active phase. Furthermore, a series of mechanically mixed catalysts were studied in the reaction in attempting to investigate the synergetic effect. The finding revealed synergetic effects in the conversion, in the yield, and in the selectivity were observed in Mg3(VO4)2 mixing with a suitable amount of MgO and Mg2V2O7 due to a solid solution of MgO in the Mg3(VO4)2 phase and the remote control mechanism, respectively. Among the biphasic catalysts, (7/4)MgVO catalyst exhibited a better catalytic performance, on which a cyclohexene selectivity of 45.7% at cyclohexane conversion of 13.9% was obtained. [ABSTRACT FROM AUTHOR]

This investigation examined the acute effects of magnesium on the dynamic changes of brain glucose, lactate, pyruvate and magnesium levels in conscious gerbils during forced swimming. Gerbils were pretreated with saline (control group) and magnesium sulfate (90 mg kg−1, intraperitoneal injection) before a 15 min forced swimming period. The basal levels of glucose, pyruvate, lactate, and magnesium in brain dialysates were 338 ± 18, 21 ± 2, 450 ± 39, and 2.1 ± 0.1 μM, respectively, with no significant difference between groups. Magnesium levels were found slightly higher (but not significant) in the magnesium-treated group. However, brain glucose and pyruvate levels in the control group decreased to about 50 and 60% of the basal level ( P = 0.01) after swimming, respectively. Pretreatment with magnesium sulfate immediately increased glucose levels to about 140% of the basal level, and increased pyruvate levels to about 150% of the basal level during forced swimming ( P = 0.01). Both glucose and pyruvate levels returned to the basal level after 30 min of the recovery. The lactate levels of the control group increased to about 160% of the basal level ( P = 0.01) during swimming, whereas pretreatment with magnesium sulfate attenuated lactate levels to 130% of the basal level ( P = 0.01). Magnesium supplementation may be beneficial because it provides an additional glucose source and may also promote the recovery of energy substrates in the brain during and after forced exercise. In order to achieve optimal physical performance, further investigation as to dosage of magnesium supplementation is needed. [ABSTRACT FROM AUTHOR]

Diffuse optical imaging enables to reconstruct distribution of optical properties, absorption and scattering coefficients, in tissue for breast cancer detection based on diffusion equation with the help of the initial guess obtained from measured data. To estimate the initial guess of the optical-property coefficients, an analytical solution of diffusion equation can be used and compared with the measured data. The analytical solution for a homogeneous infinite medium can be obtained in the frequency domain, expressing that the photon intensity and the phase lag relative to the distance between source and detector in a linear relationship. In this study, a succinct calculation using the trigonometric relation is proposed to estimate the optical-property coefficients. A tank-type and a cylinder Lipovenoes phantoms with two concentrations of 1.25% and 2.5% are employed and measured for verification. It is found that the method proposed here shows better results and results in estimation errors of 0-14.81% for μa and 20-42% for μs′. [ABSTRACT FROM AUTHOR]

An achromatic linear polarization rotator based on a tandem-2ϕ-twisted nematic liquid crystal cell (tandem-2ϕ-TNLC cell, where 2ϕ represents the total twisted angle) is theoretically analyzed and experimentally demonstrated. The tandem-2ϕ-TNLC cell comprises two conventional ϕ-TNLC cells with the required arrangement that the LC director close to the last layer of the first ϕ-TNLC cell should be perpendicular to that close to the first layer of the second ϕ-TNLC cell. With such a simple combination, the TNLC performances are considerably improved. According to the experimental results and theoretical analyses by Jones Calculus, the tandem-2ϕ-TNLC polarization rotator with suitable parameters is achromatic and insensitive to the polarization plane of incident light. Such properties provide these polarization rotators with potential for practical applications. [ABSTRACT FROM AUTHOR]

We report the enhancement of ferroelectric properties in vanadium-doped Bi4Ti3O12 (BIT) thin films prepared by rf magnetron sputtering method for MFM and MFIS structures. The optimal sputtering parameters of the as-deposited Bi3.9Ti2.9V0.08O12 (BTV) ferroelectric films for different depositing times were obtained. Compared to the undoped BIT, vanadium doped BIT (BTV) showed better physical and electrical characteristics. The as-deposited BTV showed a remanent polarization (2 P r) of 23 μC/cm2, higher than the value of 16 μC/cm2 for BIT, as the measured frequency was 100 kHz. For BTV thin films in the MFIS structure, the leakage current density and the memory window decreased, the change ratio of capacitance critically increased as the depositing time increased from 30 to 120 min. Regarding the measured physical properties, the micro-structure and thickness of as-deposited undoped and vanadium doped BIT thin films were obtained and compared by XRD patterns and SEM images. [ABSTRACT FROM AUTHOR]

Abstract  For this study, 68 plum samples were collected from 12 provinces of China. Low molecular weight RNAs were extracted and used for dot-blot, reverse transcription–polymerase chain reaction (RT-PCR), return–polyacrylamide gel electrophoresis, and biological indexing using cucumber. Results showed that 15 out of the 68 plum samples were positive for Hop stunt viroid (HSVd). Four positive samples were selected for cloning and sequence analysis. Results indicated that most HSVd sequences from the plum in China had 1–3 nucleotide changes from the closest HSVd in GenBank. In addition, the sample PB21 (cv. ‘Friar’) collected from Hebei province had one sequence with a 15-nt duplication (named HSVd D-15) at the 244/245 position in the lower central region. By biological indexing, cucumber seedlings, an indicator plant for HSVd, were inoculated with RNAs directly extracted from the original plum source (PB21, cv. ‘Friar’). Nucleotide sequencing analysis of the progeny showed that HSVd, but not HSVd-D15, was recovered from inoculated cucumbers. Although very unlikely, the possibility that this extra sequence was the result of a PCR artifact cannot be completely ruled out. [ABSTRACT FROM AUTHOR]

A new ligand, 3-methyl-4-(p-bromophenyl)-5-(2-pyridyl)-1,2,4-triazole (L) and its complexes, trans-[CuL2(ClO4)2] (1) and cis-[CoL2(H2O)2](ClO4)2⋅H2O⋅ CH3OH (2), have been synthesized and characterized by UV, IR, electrospray ionization mass spectrum, elemental analyses, and single-crystal X-ray diffraction methods. In the structure, two L ligands are stabilized by intermolecular π⋯π interactions between the triazole rings. In the complexes, each L ligand adopts a chelating bidentate mode through N atom of pyridyl group and one N atom of the triazole. Both complexes have a similar distorted octahedral [MN4O2] core (M = Cu2+ and Co2+) with two ClO4- ions in the trans position in 1 but two H2O molecules in the cis arrangement in 2. [ABSTRACT FROM AUTHOR]

Abstract  Super-multi DVD drives are assumed to have the largest market share in the near future because of their high compatibility with all kinds of DVD/CD formats and high recording-reading speed at low cost. In this paper, we present a three-axis actuator used in a super-multi drive with a special magnetic circuit, consisting of symmetric driving coils and permanent magnets with proper placement. At first, the lens holder is optimized with sensitivity method to improve the flexible vibration modes in structure parts. Then, electromagnetic circuits are designed and optimized by Taguchi method and response surface methodology (RSM). Consequently, the final model is fabricated and tested by laser vibrometer system. The results verify the proposed actuator and the integrated design methods. [ABSTRACT FROM AUTHOR]

Fibrodysplasia ossificans progressiva (FOP) is a rare congenital disease with autosomal dominant transmission characterized by the presence of malformations of the big toes and of postnatal progressive heterotopic endochondral osteogenesis. We report the case of 3-year-old girl with dysplasia of the first metatarsal bones and progressive heterotopic ossificans of the right thigh due to previous diphtheria–tetanus–pertussis immunizations and several inappropriate surgical interventions. Direct sequence analysis identified a 617G–A nucleotide mutation in the patient but not in her parents or brother. Pedigree analysis suggests that a de novo mutation in the ACVR1 gene is responsible for the disease in this family. This is the first report of the results of a mutation analysis in a sporadic case of FOP in a Taiwanese patient. [ABSTRACT FROM AUTHOR]

Artificial recombinant receptors may be useful for selectively targeting imaging and therapeutic agents to sites of gene expression. To evaluate this approach, we developed transgenes to express highly on cells a single-chain antibody (scFv) against the hapten 4-ethoxymethylene-2-phenyl-2-oxazoline-5-one (phOx). A phOx enzyme conjugate was created by covalently attaching phOx molecules to polyethylene glycol (PEG)-modified β-glucuronidase. Cells expressing phOx scFv but not control scFv receptors were selectively killed after exposure to β-glucuronidase derivatized with phOx and PEG (phOx-βG-PEG) and a glucuronide prodrug (p-hydroxy aniline mustard β-D-glucuronide, HAMG) of p-hydroxyaniline mustard. Targeted activation of HAMG produced bystander killing of receptor-negative cells in mixed populations containing as few as 10% phOx-receptor-positive cells. Functional phOx scFv receptors were stably expressed on B16-F1 melanoma tumors in vivo. Treatment of mice bearing established phOx-receptor-positive tumors with phOx-βG-PEG and HAMG significantly (P≤.0005) suppressed tumor growth as compared with treatment with βG-PEG and HAMG or prodrug alone. phOx was unstable in the serum, suggesting alternative haptens may be more suitable for in vivo applications. Our results show that therapeutic agents can be targeted to artificial hapten receptors in vitro and in vivo. The expression of artificial receptors on target cells may allow preferential delivery of therapeutic or imaging molecules to sites of transgene expression. [ABSTRACT FROM AUTHOR]