Effects of thymectomy and glucocorticoid therapy on peripheral lymphocytes in myasthenia gravis

Clinical manifestations and peripheral blood lymphocyte subset changes were studied in patients with myasthenia gravis (MG) to elucidate the mechanism of clinical improvement following treatment, with thymectomy (Tx) or glucocorticoid (GC) therapy. The changes found were: 1. There was a significant increase in percentages of CD3+, CD29+ CD4+ cells and CD4/CD8 ratio and a significant decrease in percentages of CD8+ and CD16,56+ cells in patients who had never been treated with any immune therapy. 2. After Tx or GC therapy, CD3+ and CD4+, CD29+ cells were decreased, but the number CD19+ and CD16, CD56 cells did not change. 3. Tx had a special effect on CD8+ cells. In most of the patients who showed clinical improvement after Tx, CD8+ cells were increased and CD4/CD8 ratio wad decreased. 4. Anti-acetylcholine receptor (AChRAb) titers were markedly decreased after GC therapy. These results indicate that there were obvious abnormalities in cell-mediated immunity in addition to those in humoral immunity in myasthenia gravis. These abnormalities tended to be normalized after Tx or GC therapy.     

Characterization of mutated transforming growth factor-beta s which possess unique biological properties

Transforming growth factor-beta (TGF-beta) is a potent regulator of cell growth and differentiation. On the basis of the crystal structure of TGF-beta 2, we have designed and synthesized two mutant TGF-beta s, TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73). Although both of these molecules inhibited the growth of Mv1Lu mink lung epithelial cells and LS1034 colorectal cancer cells, which are affected equally by TGF-beta 1 and TGF-beta 2, TGF-beta 1 (delta 69-73) was much less potent than TGF-beta 1 or TGF-beta 1 (71 Trp) at inhibiting the growth of LS513 colorectal cancer cells which are growth-inhibited by TGF-beta 1 but not TGF-beta 2. Both TGF-beta 1 (71 Trp) and TGF-beta 1 (delta 69-73) increased levels of mRNAs for fibronectin and plasminogen activator inhibitor with Mv1Lu cells, whereas only TGF-beta 1 (71 Trp) and not TGF-beta 1 (delta 69-73) up-regulated the mRNA level of carcinoembryonic antigen in LS513 cells. The expression level of carcinoembryonic antigen mRNA in LS1034 cells was not altered by either wild-type or mutant TGF-beta s. Receptor labeling experiments demonstrated that TGF-beta 1 (71 Trp) bound with high affinity to the cell-surface receptors of Mv1Lu, LS1034, and LS513 cells while TGF-beta 1 (delta 69-73) bound effectively to the receptors of Mv1Lu and LS1034 cells but much less to the receptors on LS513 cells.(ABSTRACT TRUNCATED AT 250 WORDS)     

Design model and guidelines for n-well guard ring in epitaxial CMOS

This work reports the development of design model for n-well guard rings in a CMOS process utilizing a low-doped epitaxial layer on a highly doped substrate. The validity of the model has been judged by a wide range of experimental data measured from the fabricated n-well guard ring structures with guard ring width as parameter. From the model developed, guidelines have been drawn to minimize the guard ring width while critically suppressing the amount of electrons escaping from the guard ring     

Effects of hot carrier induced interface state generation insubmicron LDD MOSFET's

A two-dimensional numerical simulation including a new interface state generation model has been developed to study the performance variation of a LDD MOSFET after a dc voltage stress. The spatial distribution of hot carrier induced interface states is calculated with a breaking silicon-hydrogen bond model. Mobility degradation and reduction of conduction charge due to interface traps are considered. A 0.6 μm LDD MOSFET was fabricated. The drain current degradation and the substrate current variation after a stress were characterized to compare the simulation. A reduction of the substrate current at V_g ≃0.5 V_d in a stressed device was observed from both the measurement and the simulation. Our study reveals that the reduction is attributed to a distance between a maximum channel electric field and generated interface states     

The implementation of time-domain diakoptics in the FDTD method

The time-domain diakoptics is implemented in the finite-difference time-domain (FDTD) method with two types of connecting interfaces: i) directional interface (TLM-type), and ii) total-field interface (FDTD-type). The FDTD-type interface provides a more efficient way to realize time-domain diakoptics than TLM, especially for device optimization problems. To emulate the TLM-type interface in FDTD, two novel algorithms are developed in this paper. One is to implement an ultra-wideband absorbing boundary on the excitation plane during excitation. The other is to separate directional waves without the knowledge of incident waves. For a large circuit with cascaded modules, sequential and parallel algorithms are provided to connect them. With these connecting algorithms, time-domain diakoptics is one candidate method to realize modular and parallel computation in FDTD simulations. The validity of these algorithms is confirmed by comparison with simulated results from Microwave SPICE     

Pd-Ge contact to n-GaAs with the TiW diffusion barrier

Pd-Ge based ohmic contact to n-GaAs with a TiW diffusion barrier was investigated. Electrical analysis as well as Auger electron spectroscopy and the scanning electron microscopy were used to study the contact after it was subjected to different furnace and rapid thermal annealing and different aging steps. All analyses show that TiW can act as a good barrier metal for the Au/Ge/Pd/n-GaAs contact system. A value of 1.45 × 10⁻⁶ Ω-cm² for the specific contact resistance was obtained for the Au/TiW/Ge/Pd/n-GaAs contact after it was rapid thermally annealed at 425°C for 90 s. It can withstand a thermal aging at 350°C for 40 h with its ρ_c increasing to 2.94 × 10⁻⁶Ω-cm² and for an aging at 410°C for 40 h with its ρ_c increasing to 1.38 × 10⁻⁵ Ω-cm².     

Evaluation of absorption and emission cross sections of Er-dopedLiNbO3 for application to integrated optic amplifiers

The polarization-dependent absorption and emission spectra of the ⁴I_13/2-⁴I_15/2 transition (λ~1.5 μm) in single crystal bulk Er:LiNbO₃ have been measured. Low-temperature (10 K) measurements of the Stark split energy levels of these two manifolds indicate at least two Er³⁺ sites. McCumber theory is applied to determine the Er:LiNbO₃ absorption and emission cross sections. These values are used to calculate the gain characteristics of Er:LiNbO₃ channel waveguides. Calculations indicate that a gain of 10 dB is achievable in a waveguide of several centimeters using ~20-mW pump power     

我国压铸行业及压铸机制造业的情况介绍

压力铸造（简称压铸）是金属成型技术中的一种。由于压铸生产技术的生产效率高、产品质量好、经济效益好，因此，用压铸方法生产出的零件（即压铸件）得到广泛的应用，遍及各个工业领域。其中，汽车和摩托车等交通工具作为支柱产业成为压铸零件的最大用户。航空、航天、兵器、电子等工业都是压铸零件的重要用户；还有五金、灯具、玩具、家电、电动及风动工具等行业也都大量地加以采用。