Thickness, Annealing, and Surface Roughness Effect on Magnetic and Significant Properties of Co40Fe40B10Dy10 Thin Films

In this study, Co40Fe40B10Dy10 thin films were deposited using a direct current (DC) magnetron sputtering technique. The films were deposited on glass substrates with thicknesses of 10, 20, 30, 40, and 50 nm, and heat-treated in a vacuum annealing furnace at 100, 200, and 300 °C. Various instruments were used to examine and analyze the effects of roughness on the magnetic, adhesive, and mechanical properties. From the low frequency alternating current magnetic susceptibility (χac) results, the optimum resonance frequency is 50 Hz, and the maximum χac value tends to increase with the increase in the thicknesses and annealing temperatures. The maximum χac value is 0.18 at a film thickness of 50 nm and an annealing temperature of 300 °C. From the four-point probe, it is found that the resistivity and sheet resistance values decrease with the increase in film deposition thicknesses and higher annealing temperatures. From the magnetic force microscopy (MFM), the stripe-like magnetic domain distribution is more obvious with the increase in annealing temperature. According to the contact angle data, at the same annealing temperature, the contact angle decreases as the thickness increases due to changes in surface morphology. The maximal surface energy value at 300 °C is 34.71 mJ/mm2. The transmittance decreases with increasing film thickness, while the absorption intensity is inversely proportional to the transmittance, implying that the thickness effect suppresses the photon signal. Smoother roughness has less domain pinning, more carrier conductivity, and less light scattering, resulting in superior magnetic, electrical, adhesive, and optical performance.

Preparation and Characteristics of Polyethylene Oxide/Curdlan Nanofiber Films by Electrospinning for Biomedical Applications

In this study, polyethylene oxide (PEO) and curdlan solutions were used to prepare PEO/curdlan nanofiber films by electrospinning using deionized water as the solvent. In the electrospinning process, PEO was used as the base material, and its concentration was fixed at 6.0 wt.%. Moreover, the concentration of curdlan gum varied from 1.0 to 5.0 wt.%. For the electrospinning conditions, various operating voltages (12-24 kV), working distances (12-20 cm) and feeding rates of polymer solution (5-50 μL/min) were also modified. Based on the experimental results, the optimum concentration for the curdlan gum was 2.0 wt.%. Additionally, the most suitable operating voltage, working distance and feeding rate for the electrospinning process were 19 kV, 20 cm and 9 μL/min, respectively, which can help to prepare relatively thinner PEO/curdlan nanofibers with higher mesh porosity and without the formation of beaded nanofibers. Finally, the PEO/curdlan nanofiber instant films containing 5.0 wt.% quercetin inclusion complex were used to perform wetting and disintegration processes. It was found that the instant film can be dissolved significantly on the low-moisture wet wipe. On the other hand, when the instant film touched water, it can be disintegrated very quickly within 5 s, and the quercetin inclusion complex was dissolved in water efficiently. Furthermore, when the instant film encountered the water vapor at 50 °C, it almost completely disintegrated after immersion for 30 min. The results indicate that the electrospun PEO/curdlan nanofiber film is highly feasible for biomedical applications consisting of instant masks and quick-release wound dressings, even in the water vapor environment.

[Analysis of the risk factors of persistent inflammation-immunosuppression-catabolism syndrome in patients with extensive burns]

Objective: To investigate the risk factors and treatment outcome of persistent inflammation-immunosuppression-catabolism syndrome (PICS) in patients with extensive burns. Methods: A retrospective case series study was conducted. From January 2017 to December 2021, 220 patients with extensive burns who were admitted to Guangzhou Red Cross Hospital of Jinan University met the inclusion criteria, including 168 males and 52 females, aged 18-84 (43±14) years. According to the occurrence of PICS, the patients were divided into PICS group (84 patients) and non-PICS group (136 patients). The general data such as sex, age, complication of underlying diseases and acute physiology and chronic health evaluation Ⅱ (APACHE Ⅱ) score on admission, sepsis-related organ failure evaluation (SOFA) scores on admission and 14 days post admission, and proportion of patients with mechanical ventilation over 48 h during treatment, special conditions such as total burn area, full-thickness burn area, proportion of patients admitted within 48 h post injury, and exposed deep wound area at the 30th day post injury, outcome indicators such as hospitalization day, total cost of hospital stay, number of surgeries, and death of patients in the 2 groups were collected and analyzed. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, and chi-square test. The multivariate logistic regression analysis was performed on the indicators with statistically significant differences between the two groups except for outcome indicators, and the independent risk factors influencing secondary PICS in patients with extensive burns were screened. Results: The APACHE Ⅱ and SOFA scores on admission, and proportion of patients with mechanical ventilation over 48 h during treatment of patients in PICS group were significantly higher than those in non-PICS group (t=6.78, Z=-4.75, χ2=4.74, respectively, P<0.05). There were no statistically significant differences in the rest of general data of patients between the two groups (P>0.05). The total burn area, full-thickness burn area, and exposed deep wound area at the 30th day post injury in PICS group were significantly greater than those in non-PICS group (t=6.29, Z=-7.25, Z=-8.73, P<0.05), the exposed deep wound areas at the 30th day post injury in PICS group and non-PICS group were respectively 25% (15%, 35%) total body surface area (TBSA) and 8% (0, 13%) TBSA, while the proportion of patients admitted within 48 h post injury was significantly lower than that in non-PICS group (χ2=6.13, P<0.05). The hospitalization day, total cost of hospital stay, and number of surgeries of patients in PICS group were significantly higher than those in non-PICS group (with Z values of -7.12, -8.48, and -6.87, respectively, P<0.05), while the deaths of patients in the 2 groups were similar (P>0.05). The APACHE Ⅱ score on admission and exposed deep wound area at the 30th day post injury both were the independent risk factors for PICS in patients with extensive burns (with odds ratios of 1.15 and 1.07, 95% confidence intervals of 1.06-1.25 and 1.05-1.10, respectively, P<0.05). Conclusions: The APACHE Ⅱ score on admission and exposed deep wound area at the 30th day post injury are the independent risk factors for PICS in patients with extensive burns. The patients with secondary PICS had good prognosis with more surgical intervention and hospitalization day, and higher total cost of hospital stay.

Deposition Mechanism and Characterization of Plasma-Enhanced Atomic Layer-Deposited SnOx Films at Different Substrate Temperatures

The promising functional tin oxide (SnOx) has attracted tremendous attention due to its transparent and conductive properties. The stoichiometric composition of SnOx can be described as common n-type SnO2 and p-type Sn3O4. In this study, the functional SnOx films were prepared successfully by plasma-enhanced atomic layer deposition (PEALD) at different substrate temperatures from 100 to 400 °C. The experimental results involving optical, structural, chemical, and electrical properties and morphologies are discussed. The SnO2 and oxygen-deficient Sn3O4 phases coexisting in PEALD SnOx films were found. The PEALD SnOx films are composed of intrinsic oxygen vacancies with O-Sn4+ bonds and then transformed into a crystalline SnO2 phase with increased substrate temperature, revealing a direct 3.5−4.0 eV band gap and 1.9−2.1 refractive index. Lower (<150 °C) and higher (>300 °C) substrate temperatures can cause precursor condensation and desorption, respectively, resulting in reduced film qualities. The proper composition ratio of O to Sn in PEALD SnOx films near an estimated 1.74 suggests the highest mobility of 12.89 cm2 V−1 s−1 at 300 °C.

[Analysis of the clinical characteristics and risk factors of postoperative atrial fibrillation in patients with critical burns]

Objective: To investigate the clinical characteristics and risk factors of postoperative atrial fibrillation (POAF) in patients with critical burns. Methods: A retrospective case series study was conducted. From January 2017 to December 2021, two hundred and twenty-seven critically burned aldult patients who met the inclusion criteria were admitted to Guangzhou Red Cross Hospital of Jinan University, including 173 males and 54 females, aged 19-83 (43±14) years. The admission years of patients were collected, and the percentage of patients complicated with POAF in each year was calculated. According to whether the patients were complicated with POAF or not, they were divided into POAF group (n=17) and non-POAF group (n=210). Following data were collected in patients in POAF group, including operation methods, duration of operation, intraoperative blood loss before occurrence of POAF each time, occurrence time and times of POAF, postoperative body temperature, blood pressure, hemoglobin, blood glucose, blood lactate, sepsis, and electrolyte, and type, duration, and treatment of POAF. General data of patients in the two groups including age, gender, burn reason, total burn area, full-thickness burn area, acute physiology and chronic health evaluation Ⅱ (APACHEⅡ) and sepsis-related organ failure evaluation (SOFA) scores on admission, combined with underlying diseases (hypertension, diabetes, and other types of arrhythmias), and sepsis were collected and analyzed. The mortality and factors influencing the prognosis of patients in the two groups such as mechanical ventilation time, operations times, and burn intensive care unit (BICU) length of stay were also collected and analyzed. Data were statistically analyzed with independent sample t test, Mann-Whitney U test, chi-square test or Kruskal-Wallis H test. The multivariate logistic regression analysis was performed on the general data with statistically significant differences between the two groups, and the independent risk factors influencing the onset of POAF in 227 patients with critical burns were screened. Results: From 2017 to 2021, the percentage of critically burned patients complicated with POAF increased year by year. In POAF group, eschar debridement in limbs was the main surgical procedure prior to POAF complication, with the operation time of (3.5±1.2) h and the intraoperative blood loss volume of (365±148) mL.The POAF occurred 25 times in total in patients of POAF group, mostly within one week after the injury and within 6 hours after the operation with most of these patients having POAF only once. When POAF happened, the patients were often complicated with hypothermia, anemia, hyperglycemia, high blood lactate, sepsis, and electrolyte disturbance, and few patients had complications of hypotension. The POAF lasted (5±3) h, with all being paroxysmal atrial fibrillation, and most of POAF patients were reverted to sinus rhythm after amiodarone intervention. Most patients in the two groups suffered from flame burn, and the gender, age, and SOFA score on admission of patients in the two groups were similar (P>0.05); the APACHEⅡ score on admission, total burn area, full-thickness burn area, incidence proportion of sepsis, combined with diabetes and hypertension and other types of arrhythmias of patients in POAF group were significantly higher or larger than those in non-POAF group (t=3.47, with χ2 values of 7.44, 10.86, 12.63, 14.65, 6.49, and 7.52, respectively, P<0.05 or P<0.01). The full-thickness burn area, combined with other types of arrhythmias, and sepsis were the independent risk factors for POAF in 227 critically burned patients (with odds ratios of 4.45, 0.04, and 3.06, respectively, with 95% confidence intervals of 2.23-8.87, 0.01-0.22, and 1.77-5.30, respectively, P<0.01). Compared with those in non-POAF group, the mechanical ventilation time, BICU length of stay, number of operations, and mortality rate of patients in POAF group were significantly increased (Z=3.89, Z=2.57, t=3.41, χ2=3.72, P<0.05 or P<0.01). Conclusions: POAF is a common postoperative complication in critically burned patients, and the incidence is increasing year by year, which seriously affects the prognosis of patients. The full-thickness burn area together with other types of arrhythmias and sepsis are the high-risk factors for POAF complication in patients with critical burns.

Enhanced Deep-Ultraviolet Responsivity in Aluminum-Gallium Oxide Photodetectors via Structure Deformation by High-Oxygen-Pressure Pulsed Laser Deposition

Aluminum-gallium oxide (AGO) thin films with wide bandgaps of greater than 5.0 eV were grown using pulsed laser deposition. As evidenced by X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy, the oxygen chamber pressure considerably affected the lattice deformation in the AGO materials. Under high oxygen pressure, the lattice deformation reduced the d-spacing of the AGO(-201) plane. In the measured transmittance spectra of the AGO films, this narrowing of the d-spacing in the main plane manifested as a high-energy shift of the absorption edge. The AGO films were then installed as the active layers in the metal-semiconductor-metal photodetectors (PDs). The lattice deformation was observed to enhance the photocurrent and reduce the dark current of the device. The responsivity was 20.7 times higher in the lattice-deformed AGO-based PD sample than that in the nondeformed sample. It appeared that the lattice deformation induced the separation of the piezopotential, improving the efficiency of the photogenerated carrier recombination and, consequently, shortening the decay time of the photodetector.

Temperature-Dependent HfO2/Si Interface Structural Evolution and its Mechanism

In this work, hafnium oxide (HfO₂) thin films are deposited on p-type Si substrates by remote plasma atomic layer deposition on p-type Si at 250 °C, followed by a rapid thermal annealing in nitrogen. Effect of post-annealing temperature on the crystallization of HfO₂ films and HfO₂/Si interfaces is investigated. The crystallization of the HfO₂ films and HfO₂/Si interface is studied by field emission transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and atomic force microscopy. The experimental results show that during annealing, the oxygen diffuse from HfO₂ to Si interface. For annealing temperature below 400 °C, the HfO₂ film and interfacial layer are amorphous, and the latter consists of HfO₂ and silicon dioxide (SiO₂). At annealing temperature of 450-550 °C, the HfO₂ film become multiphase polycrystalline, and a crystalline SiO₂ is found at the interface. Finally, at annealing temperature beyond 550 °C, the HfO₂ film is dominated by single-phase polycrystalline, and the interfacial layer is completely transformed to crystalline SiO₂.

Study of GaN-Based Thermal Decomposition in Hydrogen Atmospheres for Substrate-Reclamation Processing

This study investigates the thermal decomposition behavior of GaN-based epilayers on patterned sapphire substrates (GaN-epi/PSSs) in a quartz furnace tube under a hydrogen atmosphere. The GaN-epi/PSS was decomposed under different hydrogen flow rates at 1200 °C, confirming that the hydrogen flow rate influences the decomposition reaction of the GaN-based epilayer. The GaN was completely removed and the thermal decomposition process yielded gallium oxyhydroxide (GaO₂H) nanostructures. When observed by transmission electron microscopy (TEM), the GaO₂H nanostructures appeared as aggregates of many nanograins sized 2⁻5 nm. The orientation relationship, microstructure, and formation mechanism of the GaO₂H nanostructures were also investigated.

Structural and Stress Properties of AlGaN Epilayers Grown on AlN-Nanopatterned Sapphire Templates by Hydride Vapor Phase Epitaxy

In this paper, we report the epitaxial growth and material characteristics of AlGaN (Al mole fraction of 10%) on an AlN/nanopatterned sapphire substrate (NPSS) template by hydride vapor phase epitaxy (HVPE). The crystalline quality, surface morphology, microstructure, and stress state of the AlGaN/AlN/NPSS epilayers were investigated using X-ray diffraction (XRD), atomic force microscopy (AFM), and transmission electron microscopy (TEM). The results indicate that the crystal quality of the AlGaN film could be improved when grown on the AlN/NPSS template. The screw threading dislocation (TD) density was reduced to 1.4 × 10⁹ cm⁻² for the AlGaN epilayer grown on the AlN/NPSS template, which was lower than that of the sample grown on a flat c-plane sapphire substrate (6.3 × 10⁹ cm⁻²). As examined by XRD measurements, the biaxial tensile stress of the AlGaN film was significantly reduced from 1,187 MPa (on AlN/NPSS) to 38.41 MPa (on flat c-plane sapphire). In particular, an increase of the Al content in the overgrown AlGaN layer was confirmed by the TEM observation. This could be due to the relaxation of the in-plane stress through the AlGaN and AlN/NPSS template interface.

Transformation from Film to Nanorod via a Sacrifical Layer: Pulsed Laser Deposition of ZnO for Enhancing Photodetector Performance

A novel fabrication method for single crystalline ZnO nanorods by pulsed laser deposition (PLD) using a chemical-bath-deposited ZnS seed layer is proposed. For the substrate temperature (T_s) lower than 700 °C, the PLD-ZnO showed a polycrystalline phase and film-type morphology, resulting from the ZnS seed layer with a cubic phase. However, the ZnS film became a sacrifical layer and single crystalline ZnO(002) nanorods can be achieved at T_s of 900 °C, where ZnS was decomposed to zinc metals and sulfur fumes. The transformation from ZnO film to nanorod microstructure was demonstrated with the change of ZnS layer into Zn grains. Enhanced performance of the metal-semiconductor-metal photodetectors were fabricated with ZnO/ZnS samples grown at T_s of 500, 700, and 900 °C. The responsivities (@1 V and 370 nm) of these three devices were 1.71, 6.35, and 98.67 A/W, while their UV-to-visible discrimination ratios were 7.2, 16.5, and 439.1, respectively. Obviously, a higher light-capturing efficiency was obtained in the 900 °C-grown ZnO/ZnS device owing to its one-dimensional nanostructure with high crystal quality. The results indicate PLD combined with a sacrifical nanostructure is a promising method for obtaining high-quality ZnO nanorods, which paves the way for the fabrication of high performance ZnO-based devices.

Recording Characteristics, Microstructure, and Crystallization Kinetics of Ge/GeCu Recording Film Used for Write-Once Blu-Ray Disc

A Ge₆₇Cu₃₃ (16 nm) layer and a Ge (3 nm)/Ge₆₇Cu₃₃ (16 nm) bilayer were grown by sputtering at room temperature and used as the recording films for write-once blue laser media. In comparison to the crystallization temperature of Ge in a GeCu film (380.7 °C-405.1 °C), the crystallization temperature of Ge in a Ge/GeCu bilayer could be further decreased to 333.7 °C-382.8 °C. The activation energies of Ge crystallization were 3.51 eV ± 0.05 eV and 1.50 eV ± 0.04 eV for the GeCu and the Ge/GeCu films, respectively, indicating that the Ge/GeCu bilayer possesses a higher feasibility in high-speed optical recording applications. Moreover, the lower activation energy would lead to a larger grain size of Ge crystallization in the Ge/GeCu bilayer after the annealing process. Between the as-deposited and the annealed states, the optical contrasts (@ 405 nm) of the GeCu and the Ge/GeCu films were 26.0% and 47.5%, respectively. This reveals that the Ge/GeCu bilayer is more suitable for the recording film of a write-once blu-ray disc (BD-R) in comparison with the GeCu film. Based on the dynamic tests performed for 2× and 4× recording speeds, the optimum jitter values of the BD-R with the Ge/GeCu recording film were 7.4% at 6.3 mW and 7.6% at 8.6 mW, respectively.

Large-area, uniform white light LED source on a flexible substrate

This study demonstrates the flexible white LED structure with high lumen efficiency and uniform optical performance for neutral white and warm white CCT. Flip-chip LEDs were attached on a polyimide substrate with copper strips as electrical and thermal conduction paths. Yellow phosphors are mixed with polydimenthysiloxane (PDMS) to provide mechanical support and flexibility. The light efficiency of this device can reach 120 lm/W and 85% of light output uniformity of the emission area can be achieved. Moreover, the optical simulation is employed to evaluate various designs of this flexible film in order to obtain uniform output. Both the pitch between the individual devices and the thickness of the phosphor film are calculated for optimization purpose. This flexible white LED with high lumen efficiency and good reliability is suitable for the large area fixture in the general lighting applications.

Thin-film vertical-type AlGaInP LEDs fabricated by epitaxial lift-off process via the patterned design of Cu substrate

In this study, the thin-film vertical-type AlGaInP LEDs on Cu substrates were fabricated. By performing the epitaxial lift-off (ELO) process, the LED device can be transferred from GaAs to Cu substrate. Then the GaAs substrate was separated and the ELO-LED was completed. To overcome the drawback of crack formation in the epilayer during the ELO process, various patterned Cu substrates were designed. Moreover, the finite element method was used to simulate the stress distribution in the LED sample during the ELO process. From the simulation results, an optimum structure of patterned Cu substrate was obtained since its maximum stress can be confined to the chip edges and the stress was decreased significantly during the ELO process, resulting in an apparent reduction of crack generation after separating the GaAs substrate. This optimum patterned Cu substrate was employed for the fabrication of ELO-LED. In addition, the chemical etching process was also used to etch the GaAs substrate, and this device transferred to Cu substrate was denoted as CE-LED. Based on the measurements of device performances, the forward voltages (@350 mA) of the CE-LED and ELO-LED were measured to be 2.20 and 2.29 V, while the output powers (@350 mA) of these two devices were 49.9 and 48.2 mW, respectively. Furthermore, the surface temperatures (@350 mA) of these two samples were 46.9-48.3 and 45.2-47.0 °C, respectively. Obviously, the device characteristics of the ELO-LED are very similar to those of the CE-LED. It confirms that the design of patterned Cu substrate is very helpful to obtain the thin-film vertical-type AlGaInP LEDs. Additionally, via the ELO process, the separated GaAs substrate can be reused for production cost down.

Transparent conductive oxide films embedded with plasmonic nanostructure for light-emitting diode applications

In this study, a spin coating process in which the grating structure comprises an Ag nanoparticle layer coated on a p-GaN top layer of InGaN/GaN light-emitting diode (LED) was developed. Various sizes of plasmonic nanoparticles embedded in a transparent conductive layer were clearly observed after the deposition of indium tin oxide (ITO). The plasmonic nanostructure enhanced the light extraction efficiency of blue LED. Output power was 1.8 times the magnitude of that of conventional LEDs operating at 350 mA, but retained nearly the same current-voltage characteristic. Unlike in previous research on surface-plasmon-enhanced LEDs, the metallic nanoparticles were consistently deposited over the surface area. However, according to microstructural observation, ITO layer mixed with Ag-based nanoparticles was distributed at a distance of approximately 150 nm from the interface of ITO/p-GaN. Device performance can be improved substantially by using the three-dimensional distribution of Ag-based nanoparticles in the transparent conductive layer, which scatters the propagating light randomly and is coupled between the localized surface plasmon and incident light internally trapped in the LED structure through total internal reflection.

Performance of GaN-based light-emitting diodes fabricated using GaN epilayers grown on silicon substrates

Light extraction of GaN-based light-emitting diodes grown on Si(111) substrate (GaN-on-Si based LEDs) is presented in this study. Three different designs of GaN-on-Si based LEDs with the lateral structure, lateral structure on mirror/Si(100) substrate, and vertical structure on mirror/Si(100) substrate were epitaxially grown by metalorganic chemical vapor deposition and fabricated using chemical lift-off and double-transfer techniques. Current-voltage, light output power, far-field radiation patterns, and electroluminescence characteristics of these three LEDs were discussed. At an injection current of 700 mA, the output powers of LEDs with the lateral structure on mirror/Si(100) substrate and vertical structure on mirror/Si(100) substrate were measured to be 155.07 and 261.07 mW, respectively. The output powers of these two LEDs had 70.63% and 187.26% enhancement compared to that of LED with the lateral structure, respectively. The result indicated this vertical structure LED was useful in improving the light extraction due to an enhancement in light scattering efficiency while the high-reflection mirror and diffuse surfaces were employed.

Effects of crystallinity and point defects on optoelectronic applications of β-Ga₂O₃ epilayers

This study evaluates the effect of crystallinity and point defects on time-dependent photoresponsivity and the cathodoluminescence (CL) properties of β-Ga₂O₃ epilayers. A synchrotron high-resolution X-ray technique was used to understand the crystalline structure of samples. Rutherford backscattering spectroscopy was used to determine the net chemical composition of the samples to examine the type and ratio of their possible point defects. The results show that in functional time-dependent photoresponsivity of photodetectors based on β-Ga₂O₃ epilayers, point defects contribution overcomes the contribution of crystallinity. However, the crystalline structure affects the intensities and emission regions of CL spectra more than point defects.

Effect of non-vacuum thermal annealing on high indium content InGaN films deposited by pulsed laser deposition

InGaN films with 33% and 60% indium contents were deposited by pulsed laser deposition (PLD) at a low growth temperature of 300 °C. The films were then annealed at 500-800 °C in the non-vacuum furnace for 15 min with an addition of N(2) atmosphere. X-ray diffraction results indicate that the indium contents in these two films were raised to 41% and 63%, respectively, after annealing in furnace. In(2)O(3) phase was formed on InGaN surface during the annealing process, which can be clearly observed by the measurements of auger electron spectroscopy, transmission electron microscopy and x-ray photoelectron spectroscopy. Due to the obstruction of indium out-diffusion by forming In(2)O(3) on surface, it leads to the efficient increment in indium content of InGaN layer. In addition, the surface roughness was greatly improved by removing In(2)O(3) with the etching treatment in HCl solution. Micro-photoluminescence measurement was performed to analyze the emission property of InGaN layer. For the as-grown InGaN with 33% indium content, the emission wavelength was gradually shifted from 552 to 618 nm with increasing the annealing temperature to 800 °C. It reveals the InGaN films have high potential in optoelectronic applications.

Microstructures and magnetic anisotropy of single-layered Fe-Pt alloy films by in-situ annealing

The single-layered Fe-Pt films with thickness of 30 nm are in-situ deposited directly on Si substrate at various substrate temperatures (Ts) of 350 to 590 degrees C. As the Fe-Pt film is sputtered at substrate temperature is 350 degrees C, it shows (111) preferred orientation and tends to in-plane magnetic anisotropy. The L1(0) Fe-Pt film with (001) texture is obtained and exhibited perpendicular magnetic anisotropy as the substrate temperature is increased to 470 degrees C. The perpendicular coercivity (Hc perpendicular), saturation magnetization (Ms) and perpendicular squareness (S perpendicular) of this film are 6.9 kOe, 674 emu/cm3 and 0.89, respectively, which reveal its significant potential as perpendicular magnetic recording media.

Effect of Ag underlayer on microstructures and perpendicular magnetic properties of CoPt nanocomposite thin films

CoPt/Ag films were prepared by magnetron sputtering on glass substrates and subsequent annealing. The dependence of degree of ordering and magnetic properties on Ag film thickness and annealing conditions were investigated. It was found that the Ag underlayer played a dominant role in inducing the (001) texture of the CoPt film after annealing. CoPt films with a thickness about 20 nm and Ag underlayers with a thickness about 70 nm are easy to obtain a large degree of ordering and a perpendicular magnetic anisotropy after annealing at 700 degrees C for 30 min. CoPt/Ag films with out-of-plane coercivity (Hc (perpendicular)) in the range of 13.5-14.0 kOe and a out-of-plane squareness (S(perpendicular)) of 0.97 were obtained after annealing at 700 degrees C for 30 min. Ag underlayer is beneficial to enhance the Hc(perpendicular)and S(perpendicular) of CoPt film significantly. The degree of ordering and perpendicular magnetic properties of the CoPt films which deposited on Ag underlayer are larger than those of the single layer CoPt films.

Crystallization mechanisms of phase change (GeSbSn)(100-x)Co(x) optical recording films

In this study, the (GeSbSn)(100-x0Co(x) films (x = 0-13.3) were deposited on natural oxidized silicon wafer and glass substrate by dc magnetron co-sputtering of GeSbSn and Co targets. The ZnS-SiO2 films were used as protective layers. The thicknesses of the (GeSbSn)(100-x)Co(x) films and protective layer were 100 nm and 30 nm, respectively. We investigated the effects of Co addition on the thermal property, crystallization kinetics, and crystallization mechanism of the GeSbSn recording film. The crystallization temperatures of (GeSbSn)(100-x)Co(x) films were decreased with Co content. It was found that the activation energy of the (GeSbSn)(100-x)Co(x) films will decrease from 1.53 eV to 0.55 eV as Co content increased from 0 at.% to 13.3 at.%.

Microstructure and crystallization kinetics analysis of the (In15Sb85)(100-x)Zn(x) phase change recording thin films

The (In15Sb85)(100-x)Zn(x) films (x = 0 - 17.4) were deposited on nature oxidized Si wafer and glass substrate at room temperature by magnetron co-sputtering of Sb target and InZn composite target. The thermal property of the films was examined by a homemade reflectivity thermal analyzer. Microstructures of the films were analyzed by transmission electron microscope (TEM). We examined the effects of Zn addition on the thermal property, crystallization kinetics, and crystallization mechanism of the In15Sb85 recording film. As x = 0 - 17.4, thermal analysis shows that the (In15Sb85)(100-x)Zn(x) films have two phase transition temperature ranges which are 189 degrees C-215 degrees C and 300 degrees C-350 degrees C. It is found that the activation energy is increased with Zn content. This indicates that the thermal stability of amorphous state is improved by doping Zn. The optical contrasts of the films are all larger than 15%, as x = 0 - 6.2, indicating that the films have the potential in blue laser optical recording media application.

[Chemical constituents in volatile oil from fruits of Alpinia oxyphylla Miq]

OBJECTIVE

To study the chemical constituents in the volatile oil from fruits of Alpinia oxyphylla.

METHOD

Using GC-MS to identify the constituents.

RESULT AND CONCLUSION

Sixty-four compounds were identified on the basis of GC-MS, the main ones being p-cymene, valence, linalool, myrtenal, alpha-pinene, beta-pinene, furopelargone A and terpinen-4-ol. Three sesquiterpenes valencene, nootkanone and nootkanol have been isolated from the CHCl3 extract as check, of these 64 identified compounds linalyl oxide, valencene, bakkenolide A, furopelargone A and 3-hydroxycalamenene are reported for the first time.

Dynamics of renal histamine in normal rat kidney and in nephrosis induced by aminonucleoside of puromycin

Histamine is known to have a profound effect on capillary permeability in nonrenal tissues and this effect is presumably mediated by cyclic (c)AMP. Because in our previous experiments we found that histamine stimulates cAMP accumulation in glomeruli (Torres, V. E., T. E. Northryn, R. M. Edwards, S. V. Shah, and T. P. Dousa. 1978. Modulation of cyclic nucleotides in isolated rat glomeruli. J. Clin. Invest.62: 1334.), we now explored whether this amine is formed in renal tissue, namely in glomeruli, and whether its renal metabolism is altered in experimental nephrosis induced by puromycin aminonucleoside (PA) in rats. In normal rats, histamine content was higher (Delta + 240%) in cortex than in medulla. In glomeruli isolated from renal cortex, histamine content was significantly higher (Delta + 260%) than in tubules. Incubation of isolated glomeruli with l-histidine resulted in a time-dependent increase of histamine content in glomeruli, but no change was found in tubules. The increase in glomerular histamine was blocked by the histidine decarboxylase inhibitor bromocresine. In rats with PA nephrosis induced by a single intraperitoneal injection of PA (15 mg/100 g body wt) urinary excretion of histamine was markedly increased (>Delta + 200%), but control rats did not differ from rats with PA nephrosis in urinary excretions of l-histidine and of creatinine. At the peak of proteinuria (day 9 after injection of PA) the plasma level of histamine was slightly elevated, and plasma histidine slightly decreased in animals that developed PA nephrosis. The content of histamine was markedly higher and the level of histidine was significantly lower in the renal cortex of PA-nephrotic rats as compared with controls; PA-nephrotic and control rats did not differ in the content of histidine and histamine in the liver. In addition, the content of histamine was higher in glomeruli isolated from PA-nephrotic rats; lesser difference was found in cortical tubules. The results further indicate that PA-nephrotic rats have higher content of histamine in the renal cortex, predominently in glomeruli with increased urinary histamine excretion. The elevated renal cortical histamine is not due to higher availability of histamine precursor l-histidine. Results thus show that glomeruli are a major site of intrarenal histamine synthesis and accumulation, and also suggest that abnormal renal metabolism of this amine in PA nephrosis may be related, as a cause or as a consequence, to the pathogenesis of this disease.

Activities of lysosomal enzymes in isolated glomeruli. Alterations in experimental nephrosis

To study the role of lysosomal enzymes in glomeruli, we examined specific activities of lysosomal hydrolases in isolated glomeruli and, for comparison in isolated tubules, from rat kidney cortex of normal animals and animals with puromycin aminonucleoside nephrosis (PAN). Nephrotic syndrome was induced in rats by a single intraperitoneal injection of aminonucleoside and the rats were sacrificed at the time of peak proteinuria. Colloidal iron staining of renal cortex demonstrated decreased staining for the epithelial polyanion in animals with PAN. Lysosomal enzymes were determined by fluorogenic and colorimetric methods. In normal kidney, total specific activities of cathepsin beta 1, beta-2-fucosidase, acetyl-beta-glucosaminidase, and arylsulfatase were lower in glomeruli compared with tubules and with tissue slices of the same kidney. Total activity of acid phosphatase was higher in glomeruli than tubules. In glomeruli of PAN rats, there were lower activities of N-acetyl-beta-glucosaminidase, D-fucosidase, beta-glucosidase, beta-glucoronidase, and arylsulfatase compared with control rats. Activity of acid phosphatase, on the other hand, was higher in glomeruli of PAN than control rats. All differences were statistically significant. These studies demonstrate that (1) activities of lysosomal enzymes in normal glomeruli and in glomeruli of nephrotic rats have a property distinct from the rest of the kidney, and (2) the specific activities of lysosomal hydrolases are altered in glomeruli of rats with PAN. These studies suggest that changes in activities of lysosomal enzymes may be related to pathogenesis of this glomerulopathy.

Glomerular lysosomal enzymes in aminonucleoside nephrosis

Lysosomal hydrolases produce degradation of glomerular basement membrane and may play a key role in catabolism of glycoproteins of extracellular matrix in glomeruli. Therefore we investigated activities of some lysosomal enzymes and stability of lysosomes in glomeruli of normal and nephrotic rats. Nephrosis was induced in rats by single injections of puromycin aminonucleoside. In glomeruli from nephrotic rats we found lower activities of beta-fucosidase and arylsulfatase, but activity of acid phosphatase was higher compared with control rats. Osmotic stability of lysosomes measured by release of beta-glucuronidase was decreased in nephrotic rats. Abnormal activity of lysosomal enzymes and altered physiology of lysosomes in glomeruli may be a pathogenic factor in the altered glycoprotein metabolism in nephrotic syndrome and perhaps also in other glomerular diseases.