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Comparative analysis of optical characteristics of In0.08Ga0.92N/In0.03Ga0.97N multiquantum well (MQW) laser diode structures grown on freestanding GaN and on sapphire substrates is reported. Higher quantum efficiency, higher thermal activation energy, smaller Stokes-like shift, and shorter radiative lifetime are observed for InGaN MQWs on GaN substrate than those of the same MQWs on sapphire substrate. From time-resolved optical analysis, we find that not only an increase in nonradiative lifetime due to reduced dislocation density but also a decrease in radiative lifetime caused by suppressed piezoelectric field play an important role in enhancing optical properties of InGaN MQWs on GaN substrates. [ABSTRACT FROM AUTHOR]

Photoreflectance (PR) and Raman spectra were employed to investigate the interfacial characteristics of a series of oxide films on GaAs. The barrier heights across the interfaces and the densities of interracial states are determined from the PR intensity as a function of the pump power density. The oxide-GaAs structures fabricated by in situ molecular beam epitaxy exhibit low interfacial state densities in the low 10[sup 11] cm[sup -2] range. The density of the interface states of the Ga[sub 2]O[sub 3](Gd[sub 2]O[sub 3])-GaAs structure is as low as (1.24±0.14)×10[sup 10] cm[sup -2]. The Ga[sub 2]O[sub 3](Gd[sub 2]O[sub 3]) dielectric film has effectively passivated the GaAs surface. Additionally, Raman spectra were used to characterize the structural properties of the oxide films. [ABSTRACT FROM AUTHOR]

The surface barrier height and surface Fermi level of InA1As were investigated via photoreflectance spectra. Surface state density was then determined from the surface barrier height as a function of temperature, illumination power intensity, and intrinsic layer thickness. Results obtained from these three independent approaches all give the same conclusion, that the surface states are distributed over two separate regions within the energy band gap. Closely examining the photovoltage induced by various incident beam intensities revealed that the photovoltage effect is negligible when the illumination power intensity is below 1.0 µW/cm². [ABSTRACT FROM AUTHOR]

Photoreflectance is used to investigate the band gap, built-in electric field, and surface Fermi level of a series of lattice-matched In[sub 0.52]Al[sub 0.48]As surface-intrinsic n[sup +] structures having different undoped layer thicknesses. Experimental results indicate that, although the built-in electric field depends on the undoped layer thickness, there is a range of thickness within which the surface Fermi level is weakly pinned. From the dependence of electric field and surface Fermi level on the undoped layer thickness, we can determine that the surface states distribute over two separate regions within the energy band gap. The densities of the surface states are evaluated as well. Moreover, the dependence of the built-in electric field on undoped layer thickness is converted into the dependence of surface state density on the surface Fermi level in order to theoretically and exactly calculate the energy spectrum of the surface state density using a Guassian distribution function. The center and width of the distribution near the conduction band are obtained from the fitting parameters. © 2001 American Institute of Physics. [ABSTRACT FROM AUTHOR]

BBTMPO was synthesized by a condensation of 4-n butyl benzaldehyde and 4-amino 2,2,6,6-tetramethyl piperidine N-oxide (4-tempamine). The shape of the resulting spin probe, estimated using the Dreiding models, is a spherocone of length 10.7 Å capped by hemispheres of radii 6.6 and 4.0 Å, respectively. The magnetic parameters of BBTMPO in toluene at 77 K were determined. Variable temperature ESR line shape studies in the temperature range of 142–211 K revealed that BBTMPO exhibited anisotropic rotational diffusion in toluene along the long axis of the spherocone and in the direction parallel to the N–O bond. Rotational diffusion along the long axis was found to be 3±0.5 and 7±0.5 times faster for frozen and liquid toluene, respectively, than the other two axes. The line shapes have been simulated by using the stochastic Liouville theory of slow-motional effects on ESR spectrum. The slow tumbling spectrum (158 K) in the model-sensitive region showed good agreement for a Brownian model. The plot of τR vs 1/T over the whole temperature range yield a good linear fit with two slopes, with the activation energy for reorientation process of 4.9 kcal/mol in the liquid state, and 9.9 kcal/mol in the solid state. The higher activation energy of rotational reorientation coupled with a lower anisotropy of molecular reorientation (N) in the solid state, indicates that the rotational degrees of freedom is more restricted in the frozen state than in the liquid state. Molecular reorientation for BBTMPO in toluene was analyzed in terms of the hydrodynamic free space model for molecular relaxation in liquids. The stickiness factor S was found to be 0.6 while the anisotropic interaction parameter κ which measures the coupling of rotation to translation was found to be 0.7. For perdeuterated 2,2,6,6-tetramethyl-4-piperidine N-oxide (PD-Tempone) in toluene the stickiness factor was calculated to be 0.3, and κ was 0.4. The doubling in... [ABSTRACT FROM AUTHOR]

Chromium complexes, where ortho-quinone ligands are covalently linked to polymeric chains of polyethylene, polystyrene, and copolymer of ethylene and vinylacetate are studied. The results of infrared and electron paramagnetic resonance spectroscopic studies of chromium coordination polymers show that covalent linking of quinone ligands is accompanied by the change in the valence states of chromium Cr(III)↔Cr(IV)↔Cr(V). The ligand field of the triplet Cr4+ ion is close to the one in Cr-doped Y2SiO5, a laser material in the visible and infrared regions. Therefore some useful magnetic and/or optical properties in such transition metal coordination polymers can be expected. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The flexible metamaterials (MMs) provide a new field in controlling electromagnetic waves. This paper comprises the MMs made on flexible and elastic substrates, together with the relevant techniques and approaches. The perspective is also described, which includes the possible conversion of investigated MMs into practical devices. For an example of the research and development so far in this fascinating area, by using a planar and flexible MM, the low-frequency perfect absorption has been obtained even with very small unit-cell size in snake-shape structure. These shrunken, deep-sub-wavelength and thin MM absorbers were numerically and experimentally investigated by increasing the inductance. The absorbers are specially designed for absorption peaks around 2 GHz and 400 MHz, which can be used for depressing the EM noise from everyday electronic devices and mobile phones. It has been reported new concept of water droplet-based MM perfect absorber absorbing perfectly electromagnetic wave with water, an eco-friendly material which is very ordinary and plentiful on the earth. If arranging water droplets with particular height and diameter on material surface, meta-properties absorbing electromagnetic wave perfectly in GHz broadband were shown. It was possible to control absorption ratio and absorption wavelength band of electromagnetic wave according to the shape of water droplet and apply to various flexible and/or transparent substrates such as plastic, glass, and paper. These results can lead wide applications to variously civilian and military products in the future by providing perfect absorber of broadband in all products including bendable and transparent materials. [ABSTRACT FROM PUBLISHER]

Four plant species, Elymus mollis Trin., Carex kobomugi Ohwi, Glehnia littoralis F. Schmidt ex Miq., and Vitex rotundifolia L.f., are dominant perennial species in coastal sand dunes of Korea. We examined a physiological adaptation of these species by measurements of diurnal variation in photosynthesis and chlorophyll (Chl) fluorescence and solute patterns in leaves during one season (June), which is favorable for plant growth of all four species. All four species adopted different strategies in order to utilize radiation and to maintain water status under a fluctuating microclimate. Although the lowest water contents among four plant species was found, E. mollis with a high Chl and K content showed better photosynthetic performance, with high stomatal conductance ( g ), net photosynthetic rate ( P ), instantaneous carboxylation efficiency (CE), and water-use efficiency. Midday depression of P in E. mollis and G. littoralis, without a reduction of gs, was associated with a reduction in CE and maximum photochemical efficiency of PSII, indicating nonstomatal limitation. Photosynthesis depression in both C. kobomugi and V. rotundifolia, with relatively low g values, could be attributed to both stomatal and nonstomatal limitations. The high storage capacity for inorganic ions in E. molli, C. kobomugi, and G. littoralis may play an efficient role in regulating photosynthesis and maintaining leaf water status through stomatal control, and can also play an important role in osmotic adjustment. [ABSTRACT FROM AUTHOR]

We present a simple drop-casting method for preparing multiferroic nano-composite film where BiFeO3 (BFO) nanoparticles (NPs) were evenly dispersed into polyvinyl alcohol (PVA) polymer. BFO NPs used in this work were synthesized by the conventional sol-gel method, having diameter of tens of nm and being in good crystallinity. The BFO NPs were loaded into a highly insulating PVA polymer solution as filler. The multiferroic properties of the film reveal ferromagnetic ordering due to the uncompensated spiral ordering and saturated ferroelectric curves due to the cut-off of current leakage. Moreover, the prepared films show high flexibility and their multiferroicities are preserved well even in a high curved condition, reflecting the possibility for fabricating wearable devices based on multiferroic materials. [ABSTRACT FROM AUTHOR]

Mytilopsis sallei is a small marine bivalve and is considered as a serious pest. We assume that the invasive bivalve M. sallei changed the community structure of fouling macrofauna and reduced the species diversity index in Yundang Lagoon, Xiamen, China. In order to verify the above hypothesis, test panels were submerged seasonally at five stations during four seasons in Yundang Lagoon, and some chemical parameters were determined. The results showed there were significant differences in density and biomass of M. sallei and other fouling macrofauna with season and with station. The species diversity of the macrofaunal fouling community at stations B and F was low in summer, because high density of M. sallei was found at two stations. There were significantly positive correlations between density and biomass of M. sallei and water temperature and COD, and significantly negative correlations with pH. The results confirmed that this invasive species changed the density and biomass compositions of fouling macrofauna, reduced the species diversity index during the summer period, and somewhat worsened the aquatic environmental quality in Yundang Lagoon, because the pH and the DO were the lowest, and the BOD and the COD were the second lowest in summer among four seasons. [ABSTRACT FROM AUTHOR]

In this study, a novel antimicrobial peptide, scolopendin 1, was identified from adult centipedes, Scolopendra subspinipes mutilans using RNA sequencing. Scolopendin 1 exerted an antimicrobial activity without inducing haemolysis of human erythrocytes. In order to understand the antifungal mechanism, a reactive oxygen species ( ROS) assay was performed, which indicated that scolopendin 1 induced ROS accumulation in Candida albicans. Evaluation of fungal viability using N-acetyl cysteine, a ROS scavenger, suggested that ROS are a major factor in scolopendin 1-induced fungal cell death. Co-staining of annexin V-fluorescein isothiocyanate ( FITC) and propidium iodide, and TUNEL and 4′,6-diamidino-2-phenylindole ( DAPI) assays confirmed that ROS-induced fungal cell death is associated with apoptosis. To further investigate the mechanism that facilitates the progression of apoptosis, changes in intracellular Ca2+ concentration and mitochondrial dysfunction were examined. Ca2+, a signalling molecule in the apoptotic pathway, was increased in the cytosol and mitochondria, and ROS accumulation triggered mitochondrial depolarization and the release of cytochrome c, a pro-apoptotic factor, from the mitochondria to the cytosol. Finally, the released cytochrome c activated intracellular caspase. The present study suggests that scolopendin 1 could emerge as a model molecule that targets the apoptotic pathway and provides a novel remedy. [ABSTRACT FROM AUTHOR]

The omega-6 fatty acid derivative 15-Deoxy-Δ12,14-prostaglandin J2 (15d-PGJ2) is believed to play a role in cellular protection against oxidative stress in diverse cell systems. However, the cellular mechanisms by which protection is afforded by 15d-PGJ2 are not fully elucidated in vascular smooth muscle cells (VSMCs). In this study, we report the finding that 15d-PGJ2 elicited a time and concentration- dependent increase in aldose reductase (AR) expression. This induction was independent of the activation of peroxisome proliferator- activated receptor γ. Inhibition of phosphatidylinositol 3-kinase (PI3K) significantly suppressed the increase in expression and promoter activity of AR induced by 15d-PGJ2. Luciferase reporter assays demonstrated that 15d-PGJ2 targets the multiple stress response regions comprising the antioxidant response element in the promoter of the AR gene. 15d-PGJ2-mediated induction of AR promoter activity was potentiated in the presence of nuclear factor-erythroid 2-related factor 2 (Nrf2), but not in cells expressing dominant negative Nrf2. Cells treated with 15d-PGJ2 were resistant to oxidant-induced apoptotic cell death by inhibiting production of reactive oxygen species. These effects were significantly attenuated in the presence of an AR inhibitor or small interfering RNA against AR, indicating that AR plays a protective role against oxidative injury. Taken together, these findings demonstrate that activation of PI3K by 15d-PGJ2 increases the expression of AR through Nrf2, and increased AR activity may function as an important cellular response against oxidative injury. [ABSTRACT FROM AUTHOR]

One of the critical matters yet to be solved for commercial applications of extra high voltage superconducting devices is the optimum design and development of high voltage cryogenic bushings which could withstand both severe insulation requirements and a steep temperature gradient due to the cryogenic environment. Neither conventional extra high voltage bushings insulated by SF6 gas nor composite materials are directly applicable to cryogenic bushings due to an extremely low temperature environment. In order to obtain suitable dielectric performance of bushings in the cryogenic environment, we focused on an alternative insulation gas instead of SF6 such as CF4, which shows excellent dielectric performance under extremely low temperatures, and also on the optimum design of cryogenic bushings, which have a longer creepage distance compared to conventional bushings. In this paper, design factors of cryogenic bushings were discussed, and test results of 60 and 100 kV extra high voltage prototype bushings were discussed in detail. Consequently, it was possible to obtain satisfactory results to verify the insulation level of newly designed extra high voltage cryogenic prototype bushings for superconducting electric power applications. [ABSTRACT FROM PUBLISHER]

The magneto-optical (MO) properties of two-dimensional bilayered magnetic anti-dot lattice (BMAL) structure, which consists of upper perforated 'Co' layer over uniform 'Ni' underlayer in square-lattice arrangement, were investigated. Enhancement in the MO activity was found in such structures. Nearly 4 times larger MO-Kerr activity was observed for the first-order diffracted beam as compared with that of the zeroth-order one. To understand the origin of the enhanced MO rotation, the magnetization-domain configuration was also investigated by field-dependent magnetic-force microscopy. Additionally, comparison between MO response and magnetization-domain configuration for the rhomboid BMAL structure was done, which allowed us to understand more clearly the enhancement of MO properties. [ABSTRACT FROM AUTHOR]

poptosis or programmed cell death is the result of complex biochemical and genetic signals triggered by normal physiological events or by exposure to toxic compounds. Apoptosis can be revealed early in cells and tissues due to morphological and biochemical alterations of the cell. Here, we review recent progress in the study of the induction and detection of apoptosis in zooplankton copepods after their exposure to different apoptotic-inducer compounds, and we propose methods to predict copepod mortality even when animals appear normal. We also discuss the use of higher harmonic generation microscopy and multiphoton fluorescence microscopy techniques as possible tools to visualize apoptosis in vivo copepods without using any fluorescent probes. [ABSTRACT FROM AUTHOR]

In seismic isolation design of structures located at soft soil sites or near field areas, viscous dampers (VD) are often included as part of the isolation system to minimize its maximum displacement. Due to the 90° phase angle existing between the force and displacement of the VD, the maximum force transmitted by the isolation system cannot be calculated by simply combining the forces of the isolation bearings, such as lead-rubber bearings (LRB) or high damping rubber bearings (HDRB), and VD in association with the design displacement. Conforming to the code-specified equivalent lateral response procedure for isolation design, this paper presents a formula for determining the seismic design force of the combined LRB and VD isolation system, taking into account the phase angle between the combined force of the LRB and VD and the displacement of the isolation system. The numerical results have shown that the maximum responses of the isolation system predicted by the proposed formula are conservative and comparable with those from the inelastic dynamic response history analysis. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the efficacy and safety of strontium ranelate in the treatment of postmenopausal women with osteoporosis in Taiwan. In this 12-month multicenter, randomized, double-blind, placebo-controlled study, 125 women with osteoporosis were randomly given either strontium ranelate 2 g daily or placebo. Lumbar spine, femoral neck, and total-hip bone mineral density (BMD) and biochemical markers of bone turnover were measured; adverse events and tolerability were recorded and assessed. Subjects treated with strontium ranelate showed significant increases in BMD of 5.9% at the lumbar spine, 2.6% at the femoral neck, and 2.7% at the total hip, while the placebo group exhibited no significant change at 12 months. Serum level of a formation marker (bone-specific alkaline phosphatase) was also significantly increased at 6 and 12 months. Thus, although the sample size and the treatment duration of this study could not show its effect of reducing osteoprotic fractures, strontium ranelate showed bone protection effects by increasing BMD and concentrations of a bone formation marker. Safety assessment revealed adverse events were mild and not significantly different from placebo. [ABSTRACT FROM AUTHOR]

Background The pathogenesis of melasma has not yet been clearly demonstrated. We tried to determine whether the stem cell factor (SCF) and its receptor c-kit are involved in the mechanism of hyperpigmentation of melasma because this factor is highly implicated in the stimulation of melanocyte function in vitro and in vivo. Objectives The present study was conducted to investigate the expression of SCF and c-kit on the lesions of melasma compared with nonlesional skin. Patients/methods Skin samples were obtained from lesional and nonlesional facial skin of 60 Korean women with melasma. Immunohistochemistry and reverse transcriptase-polymerase chain reaction (RT-PCR) analysis was performed to determine the expression of SCF and c-kit in melasma. Results The expression of SCF was significantly increased at the lesional dermis compared with nonlesional dermis. However, there was no significant difference in the expression of SCF in lesional and nonlesional epidermis. The expression of c-kit was significantly increased at lesional epidermis compared with nonlesional skin. RT-PCR of SCF and c-kit mRNAs demonstrated increased expression of both types of transcripts in the lesional skin compared with nonlesional skin. Conclusions These results suggest that the increased expression of SCF in the dermis and of c-kit in the epidermis play an important role in the mechanism of hyperpigmentation in melasma. [ABSTRACT FROM AUTHOR]

This study compared the clinical efficacy, safety, and tolerability of daily subcutaneous injections of teriparatide and salmon calcitonin in the treatment of postmenopausal women with established osteoporosis in Taiwan. This 6-month, multicenter, randomized, controlled study enrolled 63 women with established osteoporosis. They were randomized to receive either teriparatide 20 µg or calcitonin 100 IU daily in an open-label fashion. Lumber spine, femoral neck, total hip bone mineral density (BMD), and biochemical markers of bone turnover were measured, and adverse events and tolerability were recorded. The results at 6 months showed that patients using teriparatide had larger mean increases in spinal BMD than those who used calcitonin (4.5% vs. 0.1%), but the BMD changes in these two groups at the femoral neck and the total hip were not significant. There were also larger mean increases in bone markers in the teriparatide group than in the calcitonin group (bone specific alkaline phosphatase 142% vs. 37%; osteocalcin 154% vs. 23%). We conclude that teriparatide has more positive effects on bone formation than salmon calcitonin, as shown by the larger increments of lumbar spine BMD and bone formation markers, and caused only mild adverse events and no significant change in liver, kidney or hematological parameters. Compared with the published global results, teriparatide seems to be equally effective and safe to use in this Asian population. [ABSTRACT FROM AUTHOR]

The aim of this study was to investigate the relationship between serum levels of the glycoxylation productNε-(carboxymethyl)lysine (CML) and development of chronic diabetic complications and degree of diabetic control in children and adolescents with type 1 diabetes.The serum levels of CML were measured in 87 patients with uncomplicated type 1 diabetes mellitus (12.7 ± 4.6 years of age) and in seven patients with background retinopathy, microalbuminuria or neuropathy (18.2 ± 5.2 years of age) and compared with those in 64 normal control subjects (12.6 ± 5.2 years of age). The mean durations of diabetes in uncomplicated and complicated patients were 5.0 ± 3.4 years (0.1–14 years), and 8.6 ± 5.0 years (3.1–18 years), respectively. The serum levels of CML were measured by enzyme-linked immunosorbent assay using a monoclonal anti-CML antibody (6D12).The serum levels of CML were significantly higher in the patient group than those in the control group; 0.85 ± 0.37 (0.37–1.93) U/ml vs. 0.56 ± 0.23 (0.15–1.05) U/ml (p < 0.001) and significantly higher in the patient group with chronic complications than those in patient group without chronic complications; 1.06 ± 0.39 (0.72–1.78) U/ml vs. 0.83 ± 0.36 (0.37–1.93) U/ml (p < 0.05). Weak, but statistically significant relationship between CML levels and haemoglobin A1c levels at the measurement of CML was observed (r = 0.29, p < 0.05).Our data are suggesting that higher serum levels of CML are involved in the development of chronic diabetic complications, and serum levels of CML reflect the degree of diabetic control for a long duration in type 1 diabetic children and adolescents. [ABSTRACT FROM AUTHOR]

The paper summarizes the feasibility study of implementing seismic protective systems into high-tech industrial structures in which costly vibration-sensitive facilities are housed. Due to the fact that the microvibration of an existing integrated circuit (IC) fab structure plays an important role in affecting the chip probe yield of manufacturing and the reliability of chip products, the paper has emphasized on the microvibration analysis and measurement of a test structure before and after the seismic protective systems have been incorporated. The theoretical background of one-third octave frequency spectra is derived. Based on the study, it is found that the incorporation of viscous dampers will not only enhance the seismic safety but also minimize the microvibration of the structure. The seismic isolation design is the most promising method to achieve the “fully operational” seismic performance level of an IC fab. However, the amplification of the microvibration at the low frequency range due to the implementation of seismic isolation design will require further study to ascertain its effect on the operation of vibration-sensitive facilities. [ABSTRACT FROM AUTHOR]

Hydrostatic pressures (50 to 300 MPa) were applied at 0 °C for 50 min to determine the aggregation and viscoelastic properties of tilapia ( Orechromis niloticus) myosin fragments: subfragment-1 (S-1) and rod. With pressure lower than 150-MPa treatment, S-1 underwent intermolecular interaction to increase its elastic properties. After a 200-MPa treatment, S-1 unfolded, aggregated, and decreased its solubility. A turbid solution was obtained after pressurization over 200 MPa. Further, S-1 transformed to a more elastic gel with pressure increasing. At 200 MPa, S-1 denatured entirely with no change of enthalpy detected by differential scanning calorimetry (DSC). However, all properties of rod did not change during pressurization. This study reveals that S-1 contributes the initiation of gel formation in myosin, and the role of rod is not clear. Keywords: hydrostatic pressure, S-1, rod, denaturation [ABSTRACT FROM AUTHOR]

The copepod assemblage in the coastal waters of southwestern Taiwan was studied in January, June, and October 1997. Sixty-six species of copepods were found in samples collected in the upper 5 m of the water column. Abundant species included Acrocalanus gracilis , Canthocalanus pauper , Clausocalanus arcuicornis , Clausocalanus furcatus , Euchaeta rimana , Oncaea media , Paracalanus nanus , Temora turbinata , and Undinula vulgaris. Small copepods (<1 mm) made up the greatest proportion of the copepod community in terms of numerical abundance. Small- and medium-sized (1-2 mm) copepods contributed almost equally to the total copepod dry weight biomass. Large copepods (>2 mm) made up <5% of the copepod community in terms of numerical abundance and <20% in terms of dry weight biomass. [ABSTRACT FROM AUTHOR]

The hydroxylation of benzene and phenol with in-situ-generated oxidant was performed under mild reaction conditions over the bicatalytic system which has dual abilities of direct H[sub 2]O[sub 2] generation and the hydroxylation activity by combining Pd-zeolite with redox zeolites such as TS-1, Ti-MCM-41, V-MCM-41 and Fe-zeolite. The amount of H[sub 2]O[sub 2] formed directly from H[sub 2] and O[sub 2] increases with increasing Pd loading over zeolite up to 0.6% and subsequently decreases slightly as the Pd loading increases. The optimum amount of H[sub 2]O[sub 2] produced is 6.4 mmol. Over Pd/HBEA + Fe/Y, when H[sub 2] : O[sub 2] = 40 : 40 ml/min is supplied, phenol conversion increases from 4.6% at 2 h to 13.6% at 8 h with high catechol selectivity in the range of 65–79%. The hydroxylation activities over redox catalyst with H[sub 2]O[sub 2] are compared. Hydroxylation activity is improved by encapsulating FePc onto Y zeolite. In terms of TON, FePc/Y exhibits 3.5 times higher capacity than Fe/Y. [ABSTRACT FROM AUTHOR]

Day and night abundance of copepods in the coastal waters off southwestern Taiwan was studied during a cruise on 26-28 December 1997. A total of 14 zooplankton samples (7 daytime and 7 nighttime) was taken at seven stations using a one-meter mouth opening net with 333 μm mesh, and a Hydrobios flowmeter mounted in the centre of the mouth. The mean numerical abundance of copepods was 123 ± 69 ind./m3. In all, 67 species of copepods belonging to 16 families and 31 genera were identified. Among these, Paracalanus aculeatus (32% of the numerical total of copepods), Acrocalanus gracilis (31%), and Oncaea venusta (11%) were the most dominant species and occurred at every station. Most species were more abundant during the day than at night. Both the index of species diversity and that of species number of copepods were higher at the northern stations and decreased toward the southern stations at night, but behaved in the opposite manner during the day. From the results of cluster analysis, four station groups were formed: daytime northern stations, daytime southern stations, nighttime northern stations, and nighttime southern stations. The daytime northern station group was most distinct from the others. Four copepod groups were also distinguished and are herein discussed. [ABSTRACT FROM AUTHOR]

Purpose : To elucidate the immunological change incurred in a human population by protracted gamma-radiation exposure at home environment. Materials and methods : An examination on the CD3+, CD4+, CD8+ and HLA-DR+ lymphocyte subsets was arranged for 196 exposed subjects with mean excess cumulative dose of 169mSv during 2-13 years of exposure. Another 55 close relatives of the exposed subjects were recruited as the non-exposed reference population. Results : The mean percentages of CD4+ T-lymphocytes, HLA-DR+ lymphocytes and the CD4+/CD8+ ratios in the exposed subjects (35.5, 19.9 and 1.51 respectively) were significantly lower than those of reference individuals (38.0, 22.6 and 1.72; p 0.02, 0.003, and 0.03 respectively), while the CD8 in total counts of the exposed was moderately increased above that of the reference populations (p=0.1). By ANOVA analysis, the percentages of CD4+ and HLA-DR+ subsets were significantly associated with radiation dose (p =0.0046, 0.003), while CD4+/CD8+ ratios were moderately associated with dose (p=0.073). HLA-DR+ counts were significantly and positively associated with duration of relocation from radioactive apartments (p=0.029). Conclusions : Significant immunological effects were observed in those who had received chronic low-dose radiation exposure. [ABSTRACT FROM AUTHOR]

1991 Mathematics Subject Classification 11H50. [ABSTRACT FROM AUTHOR]

We have prepared BiFe0.95Ni0.05O3 by the standard solid-state reaction and rapid sintering. The structural analysis by x-ray diffraction for BiFe0.95Ni0.05O3 shows rhombohedral perovskite structure (R3c), and lattice constants a and c of BiFe0.95Ni0.05O3 are slightly increased as compared to those of BiFeO3. The Raman studies present the increase of oxygen vacancy by the Ni2+ substitution. The magnetic properties of BiFe0.95Ni0.05O3 are greatly improved, owing to the enhanced ferromagnetic interaction caused by the Fe/Ni coupling. BiFe0.95Ni0.05O3 sample is ferromagnetic with a cluster-glass state unlike the antiferromagnetic BiFeO3-based compounds. [ABSTRACT FROM AUTHOR]

The article presents a study on the three-year old girl who was diagnosed with Type one mellitus and presented with diabetic ketoacidosis and cerebra; infarction and transient visual loss. It states that an evolving infarct in the occipital lobes and cerebral oedema was revealed by cranial compute tomography scan. It mentions that an echocardiography was performed to identify the possible causes of the cerebral infarction of the girl.

Direct comparison of optical properties and carrier dynamics of InGaN multiple quantum well (MQW) laser diode structures grown on pendeo epitaxial (PE)-GaN and sapphire substrates is reported. A strong increase in quantum efficiency and a dramatic reduction in stimulated emission threshold are observed for InGaN MQWs on PE-GaN substrates as compared to MQWs on sapphire substrates. Based on temperature-dependent time-resolved optical analysis, the authors find that a significant increase in nonradiative lifetime due to suppressed dislocation density plays an important role in enhancing optical properties of InGaN MQWs grown on PE-GaN substrates, resulting in radiative-process dominant emission even at room temperature. [ABSTRACT FROM AUTHOR]

Temperature-dependent photoreflectance measurements are employed to characterize the electronic band structure of InGaPN grown on GaAs substrates. In addition to the fundamental band gap, the upper subband E+ is observed as predicted by the band anticrossing (BAC) model. By eliminating the contributions of the epitaxial-strain and atomic-ordering effects in InGaPN and also assigning the localized state energy EN introduced by an isolated N to be 2.040 eV at 293 K, the interaction potential V is determined as 1.449±0.170 eV. The incorporation of a temperature-dependent EN level into the BAC model fits the experimental data better than assuming EN to be a constant. This contrasts with previously published results and so provides a different view of the temperature dependence of the EN level in InGaPN. [ABSTRACT FROM AUTHOR]

A 47 year old Chinese man with diabetes mellitus and previously treated pulmonary tuberculosis presented with painless right testicular enlargement of 1 month's duration. He underwent an orchidectomy for presumed testicular neoplasm corroborated clinicoradiologically. Histological examination of the testicular mass revealed an inflammatory lesion comprising lymphocytes, plasma cells and sheets of pale staining histiocytes, some containing lymphocytes within their ample cytoplasm, suggestive of emperipolesis. $100 immunohistochemistry stained the histiocytes, while ultra-structural examination confirmed emperipolesis. A diagnosis of Rosai-Dorfman disease was made, an exceedingly rare testicular lesion. Clinicoradiological findings mimicked a neoplasm, while the inflammatory histological appearances with occasionally discerned multinucleated cells raised the possibility of xanthogranulomatous orchitis. Tuberculous orchitis was excluded through negative Ziehl-Neelsen stains and PCR for mycobacterium, while seminoma, which sometimes features a predominant inflammatory component obscuring neoplastic cells, was excluded by absent immunostaining for placental alkaline phosphatase and CD117. [ABSTRACT FROM AUTHOR]

This study examines terahertz radiation from a series of In0.52Al0.48As and GaAs surface-intrinsic-N+ structures (SIN+) with surface-intrinsic layers of various thicknesses. The built-in electric fields in the SIN+ structures are used as the bias. Experimental results indicate that the amplitudes of the THz emission are independent of the built-in electric fields in the emitters when the built-in electric fields exceed the corresponding critical electric fields of the semiconductors. In contrast, the amplitudes of the THz emission are proportional to the thickness of the intrinsic layer and, therefore, the number of photo-excited charged carriers. [ABSTRACT FROM AUTHOR]

A simple method to enhance atomic force microscopy local oxidation by coating the substrate with a thin layer of gold is reported. The effect of gold coating is demonstrated experimentally by atomic force microscopy oxidation at various thicknesses of gold on Si and InP. Oxide heights reaching 30 nm are easily achieved on silicon at rates 10 times greater than traditional methods. The gold layer is assumed to increase conductance and current during oxidation, thereby reducing decline in growth rates caused by the increasing resistance of the growing oxide layer itself. Improvement in growth rate and height increases with increasing gold thickness up to a maximum height, but beyond that thickness the heights and rates decrease because the gold layer itself becomes a barrier to the migration of oxyions. The presented method is demonstrated to improve the oxidation rate and height on normal and highly resistive substrates, with lower requirements for applied voltage during oxidation. [ABSTRACT FROM AUTHOR]

Room-temperature photoreflectance (PR) and photoluminescence (PL) spectra are measured for a series of In0.54Ga0.46P1-yNy/GaAs heterostructures grown on GaAs (100) substrate. Redshifts of the PR and PL peaks indicate that the band gap of In0.54Ga0.46P1-yNy is dramatically reduced as nitrogen is incorporated. The emergence of additional peaks in PR spectra as nitrogen is incorporated indicates that the band alignment switches from type I to type II, due to the lowering of the conduction band, thus forming a two-dimensional electron gas (2DEG) in the interface region between In0.54Ga0.46P1-yNy and GaAs. The band gap energy and transition energies between the confined levels in the 2DEG are determined for samples with various nitrogen concentrations y. The number of confined levels in the 2DEG is found to increase with y; the composition-dependent bowing parameter is determined. [ABSTRACT FROM AUTHOR]

We demonstrate the effect of Ti thickness on the contact resistance between GaN nanowires and Ti/Au electrodes. We have carried out systematic characterization of many GaN nanowires contacted by various Ti/Au electrodes. We conclude that the average resistance is reduced by almost six orders of magnitude as Ti thickness increases from 0 to 20 nm, and the resistance value then saturates when the Ti thickness further increases. Our observation can be explained by the formation of TiOx through the reaction of surface oxide and the Ti layer. Scanning Auger microscopy of the Au/Ti/SiO2 interface also supports this explanation. [ABSTRACT FROM AUTHOR]

We report electrical transport through 60 base pairs of poly(dG)-poly(dC) DNA molecules. The DNA solution is dropped on two metal electrodes with the gap of 20 nm. The current-voltage characteristics measured between the electrodes exhibits clear staircases, which are reproducible over repeated measurements. The size of the observed staircases is consistent with the energy gap obtained from a tight binding calculation. [ABSTRACT FROM AUTHOR]

It has been well proved that there are infinitely many resonances in the scattering problem provided the potential V(t) satisfies the moment conditions ∫∞0|V(t)|tn dt =O(n(1-ε)n), ε>0, n=0,1, ... . In particular, if V(t) has a compact support then the result of Rollnik [H. Rollnik, Z. Phys. 145, 654 (1956)] and Regge [T. Regge, Nuovo Cimento, 8, 671 (1958)] is obtained and if |V(t)|∼exp(-τt1+ε), τ,ε>0, we have the results of Sartori [L. Sartori, J. Math. Phys. 4, 1408 (1963)]. [ABSTRACT FROM AUTHOR]

We have systematically analyzed the effect of strain on the electrical properties of flexible field effect transistors with a single-walled carbon nanotube (SWCNT) network on a polyethersulfone substrate. The strain was applied and estimated at the microscopic scale (<1 μm) by using scanning electron microscope (SEM) equipped with indigenously designed special bending jig. Interestingly, the strain estimated at the microscopic scale was found to be significantly different from the strain calculated at the macroscopic scale (centimeter-scale), by a factor of up to 4. Further in-depth analysis using SEM indicated that the significant difference in strain, obtained from two different measurement scales (microscale and macroscale), could be attributed to the formation of cracks and tears in the SWCNT network, or at the junction of SWCNT network and electrode during the strain process. Due to this irreversible morphological change, the electrical properties, such as on current level and field effect mobility, lowered by 14.3% and 4.6%, respectively. [ABSTRACT FROM AUTHOR]

Photoreflectance (PR) spectra at various temperatures and photoluminescence (PL) spectra and high-resolution x-ray rocking curve (XRC) measurements are used to investigate the band alignment, epitaxial-strain, and atomic-ordering effects in In0.54Ga0.46P1-yNy/GaAs (y=0%–2.0%) heterostructures. The existence of additional peaks in PR spectra at higher levels of nitrogen (N) incorporation implies that the band alignment switches from type I to type II, due to the lowering of the conduction band. The electric field at the interface is determined and is discussed with the N content. Redshifts of the PR and PL peaks indicate that the band gap of InGaPN is dramatically reduced as N is incorporated. The valence-band splitting (VBS) and the spin-orbit splitting of InGaPN are obtained from PR spectra. High-resolution XRC measurements indicate that as the N content increases, the lattice mismatch and the compressive strain between the epilayer and GaAs substrate decrease while the VBS increases, which implies an increase in the degree of ordering in InGaPN caused by the transition from a cubic zinc blende structure to a [111] CuPt structure. The order parameter η of InGaPN deduced from the VBS ranges from 0.256 to 0.498, indicating that the InGaPN epilayer becomes more ordered with increasing N incorporation. [ABSTRACT FROM AUTHOR]

Ice-binding proteins (IBPs) inhibit the growth and recrystallization of intracellular ice, enabling polar organisms to survive at subzero temperatures. IBPs are promising materials in biomedical applications such as cryopreservation and the hypothermic storage of cells, tissues, and organs. In this study, recombinant IBP from the antarctic bacterium Flavobacterium frigoris PS1 (FfIBP) was produced by Escherichia coli used as bioreactor, to examine the feasibility of scale-up. Oxygen transfer was the most important factor influencing cell growth and FfIBP production during pilot-scale fermentation. The final yield of recombinant FfIBP produced by E. coli harboring the pET28a-FfIBP vector system was 1.6 g/L, 3.8-fold higher than that from the previously published report using pCold I-FfIBP vector system, and its thermal hysteresis activity was 2.5°C at 9.7 µM. This study demonstrates the successful pilot-scale production of FfIBP. [ABSTRACT FROM AUTHOR]

Presents information on a study which applied the quantum Hall effect measurements on modulation-doped gallium arsenic (GaAs)/aluminum GaAs heterostructures. Experimental procedures; Results and discussion; Conclusion.

Presents a study that investigated the variations of Raman spectra for silicon-implanted gallium antimonide (GaSb) with various doses and energies. Advantages of ion-implantation technology over diffusion; Analysis of the Raman spectrum of the unimplanted GaSb wafer; Reasons for the broadening and weakening of the transverse and longitudinal optical phonon modes.

We report on mechanochemical synthesis and magnetic and electric properties of organic polymeric semiconductor that contains paramagnetic and ferromagnetic particles. As starting materials we used polyaniline (emeraldine base), polystyrene, FeCl3, and elemental sulfur. These components were chosen for the purpose of obtaining semiconductor polymer composite containing magnetic iron nanoparticles and having flexible thermomechanical properties. The presence of nanoparticles was evidenced by scanning electron microscopy. The value of conductivity of the Fe-doped polymer composite was increased by several orders of magnitude compared to the initial undoped polyaniline. Temperature dependence of the conductivity shows semiconductor character of the composite material. [ABSTRACT FROM AUTHOR]

Abstract: The brackish cyclopoid copepod Apocyclops royi is used in Taiwanese aquaculture industry as a prey for fish larvae. This study investigated the effects of seven microalgal diets, namely single‐species diets of Isochrysis galbana (ISO), Nannochloropsis oculata (NAN), and Tetraselmis chui (TET), two‐species diets (ISO+NAN, ISO+TET and TET+NAN), and a three‐species diet (ISO+NAN+TET), on the population growth, female fecundity and fatty acid composition of A. royi. For reproductive traits, the combination ISO+NAN was found to be the most supportive diet for both population growth and female fecundity. For nutritional value, copepods fed ISO and ISO+NAN were detected to have the highest content of docosahexaenoic acid (DHA) (18.99% and 10.73% total fatty acid, respectively) and, more importantly, a high DHA/EPA ratio (6.09 and 4.09, respectively). Additionally, a comparison of fatty acid composition between copepods and microalgae gives a tentative indication that A. royi may have the ability to synthesize long‐chain polyunsaturated fatty acids (PUFA) from short‐chain PUFA. Our findings illustrate that ISO+NAN is the most suitable microalgal diet for mass culturing A. royi because it increases productivity and enhances the nutritional value of the copepods for use as fish larvae prey. [ABSTRACT FROM AUTHOR]

By means of mechanochemical synthesis we obtained a coordination polymer containing binuclear manganese complexes with organic catechol/ortho-quinone ligands. The reaction system contained polystyrene, manganese acetylacetonate, and donor-acceptor mixture catechol/ortho-quinone. Electron paramagnetic resonance (EPR) and infrared spectroscopic data show that the binuclear manganese complex is covalently linked to the chain of polystyrene. Theoretical EPR spectrum analysis revealed a triplet state of the complex with two nonequivalent manganese ions coupled to each other by spin exchange. The type of magnetic coupling between manganese ions in this system is similar to the one in manganese based inorganic magnetic materials. [ABSTRACT FROM AUTHOR]

We report on synthesis of Co, Ni, and Fe nanoparticles by the action of elastic wave pulses on solid phase sandwich type samples containing metal salt, reducing agent, polyethylene, and polyacrylamide. The formation of metal nanoparticles is evidenced by ferromagnetic resonance and scanning electron microscopy. The product yield for the nanoparticles formation has a threshold character with the pressure in the elastic wave pulse. The maximum amount of Co, Ni, and Fe nanoparticles is observed around 20 kbar of pressure in elastic wave pulses. The presence of polyacrylamide in reaction composites increases the stability of metal nanoparticles to oxidation by two orders of magnitude. © 2004 American Institute of Physics. [ABSTRACT FROM AUTHOR]

The bandgap, surface Fermi level, and surface state density of a series of GaAs1-xSbx surface intrinsic-n+ structures with GaAs as substrate are determined for various Sb mole fractions x by the photoreflectance modulation spectroscopy. The dependence of the bandgap on the mole composition x is in good agreement with previous measurements as well as predictions calculated using the dielectric model of Van Vechten and Bergstresser in Phys. Rev. B 1, 3551 (1970). For a particular composition x, the surface Fermi level is always strongly pinned within the bandgap of GaAs1-xSbx and we find its variation with composition x is well described by a function EF = 0.70 - 0.192 x for 0 <= x <= 0.35, a result which is notably different from that reported by Chouaib et al. [Appl. Phys. Lett. 93, 041913 (2008)]. Our results suggest that the surface Fermi level is pinned at the midgap of GaAs and near the valence band of the GaSb. [ABSTRACT FROM AUTHOR]