Transient-enhanced diffusion in shallow-junction formation

Shallow junctions are formed in crystalline Si by low-energy ion implantation of B⁺, P⁺, or As⁺ species accompanied by electrical activation of dopants by rapid thermal annealing and the special case of spike annealing. Diffusion depths were determined by secondary ion-mass spectroscopy (SIMS). Electrical activation was characterized by sheet resistance, Hall coefficient, and reverse-bias diode-leakage measurements. The B⁺ and P⁺ species exhibit transient-enhanced diffusion (TED) caused by transient excess populations of Si interstitials. The electrically activated fraction of implanted dopants depends mainly on the temperature for B⁺ species, while for P⁺ species, it depends on both temperature and P⁺ dose. The relatively small amount of diffusion associated with As⁺ implants is favorable for shallow-junction formation with spike annealing.     

Effects of exercise-induced oxidative stress on nitric oxide release and antioxidant activity

This study shows that acute exercise in healthy subjects is a modest oxidative stress, which may be related to an increase in antioxidant activity and down-regulation of nitric oxide formation.     

Detection of oxidative stress in heart by estimating the dinitrophenylhydrazine derivative of malonaldehyde

Accurate estimation of the oxidative stress in heart is necessary because the pathogenesis of many heart diseases are believed to be mediated at least in part from the development of oxidative stress resulting from the generation of oxygen free radicals and reduced antioxidant defense system. The most widely used method for this purpose has been the estimation of malonaldehyde (MDA), a lipid peroxidation product, by the thiobarbituric acid (TBA) reaction method. However, because of the nonspecificity of this method, the results are often erroneous. The present report describes a method using high-performance liquid chromatography (HPLC) to estimate MDA. To develop the oxidative stress, two different models were used: ischaemic-reperfused heart and perfusing the heart with a hydroxyl radical (OH+) generating system. The coronary effluents obtained from the isolated rat heart before ischaemia and during the reperfusion of ischaemic heart, as well as during the perfusion of the heart with the OH+ generating system were collected, derivatized with 2,4-dinitrophenylhydrazine (DNPH) and extracted with pentane. Aliquots of 25 microliters in acetonitrile were injected onto a Beckman Ultrasphere C18 (3 microns) column. The products were eluted isocratically with a mobile phase containing acetonitrile-water-acetic acid (40:60:0.1, v/v/v), measured at 307 nm using a Waters M-490 multichannel UV detector and collected for gas chromatography-mass spectrometry (GC-MS). The peaks were identified by co-chromatography with DNPH derivatives of authentic standards, peak addition, and by GC-MS. The retention time for MDA-DNPH was 5.3 min.(ABSTRACT TRUNCATED AT 250 WORDS)     

离子法入机Ⅶ Sta平台向掺杂工艺的无缝可变换性

离子注入机ⅦSta平台对≤130 nm尺寸CMOS工艺在整个能量和剂理范围提供单片注入.这些注入机的特征是硬件和设计原理通用,并包含离子束注入角控制、剂量测定和终端站设计.这种方法对重叠剂量范围能使工艺可完全互换,并对引起制造所有权成本(COO)降低提供了最大的灵活性.一个完整工艺的透彻性需要剂量形貌特征精确匹配,并很好地说明这一能力、晕圈效应、VT和延展注入.此外,也证实了ⅦSta平台的单片设计消除了缺陷来源,确保了无风险工艺互换.     

A 12-bit integrated analog front end for broadband wirelinenetworks

An integrated transceiver for broadband wireline networks is presented. The transceiver includes a receive data path, a transmit data path, and auxiliary functions including serial port interface, clock and reference generation blocks, and voltage regulator control circuitry. The receive data path provides constant input impedance and is composed of two variable gain amplifier (VGA) blocks, a tuned analog 4-pole filter, a 12-b analog-to-digital converter (ADC) sampling at 32 MHz, and a digital high-pass filter. Filter tuning using switched-capacitor arrays occurs in the background, with no effect on signal reception. The transmit data path contains digital interpolation filters and a 12-b digital-to-analog converter (DAC) sampling at 128 MHz. The chip was implemented in double-poly triple-metal 0.35-μm CMOS technology. Measured performance for both receive and transmit data paths meets target specifications with no noticeable crosstalk     

Grinding-Induced Texture in Ferroelastic Tetragonal Zirconia

Ceria- and yttria-doped tetragonal polycrystalline zirconia ceramics were ground at temperatures as high as 1100°C. X-ray diffraction revealed that the intensity ratio I ₍₀₀₂₎/ I ₍₂₀₀₎ increased (to as high as ∼4.5) compared with that from the as-sintered surfaces (∼0.55). The enhancement in I ₍₀₀₂₎/ I ₍₂₀₀₎ at temperatures well above the m → t transition temperature shows that it is not related to transformation, reversible or otherwise, but can be explained by ferroelastic domain switching.     

UDP-GlcNAc:Ser-protein N-acetylglucosamine-1-phosphotransferase from Dictyostelium discoideum recognizes serine-containing peptides and eukaryotic cysteine proteinases

Phosphoglycosylation catalyzed by UDP-GlcNAc:Ser-protein N-acetylglucosamine-1-phosphotransferase (Ser:GlcNAc phosphotransferase) adds GlcNAcalpha-1-P to peptidyl-Ser of selected Dictyostelium discoideum proteins. Lysosomal cysteine proteinase (CP), proteinase-1(CP7), is the major phosphoglycosylated protein in bacterially grown amoebae. GlcNAc-1-P is added within a Ser-rich domain containing SSS, SGSG, or SGSQ repeated motifs that are not found in other papain-like CPs. We studied the substrate specificity of the transferase using peptides containing these motifs and 12 other peptides with one or more Ser residues. Phosphoglycosylation is comparable for all three Dictyostelium CP motifs, but it is not restricted to them. Flanking residues in the other peptides strongly influence phosphoglycosylation efficiency. Dictyostelium microsomal membranes also phosphoglycosylate endogenous acceptors, and some of these acceptors occur as an 18 S complex with the transferase. CP-serine motif peptides inhibit endogenous acceptor phosphoglycosylation weakly (30-40%) at 800 microM, whereas catalytically inactive proteinase-1(CP7) and other non-phosphoglycosylated eukaryotic CPs, lacking the serine domain, inhibit transferase activity at 1-4 microM. SDS denaturation destroys the inhibitory potential of all CPs showing that transferase recognizes a conformation-dependent feature that is shared by all. Proteinase-1(CP7) expressed in Escherichia coli lacks GlcNAc-1-P, but it is a substrate for Ser:GlcNAc phosphotransferase, Km = 5.6 microM. Thus, Ser:GlcNAc phosphotransferase recognizes both acceptor peptide sequences and a conformational feature of eukaryotic CPs. This may be physiologically important for establishing or maintaining non-overlapping groups of GlcNAc-1-P- and Man-6-P-modified Dictyostelium proteins that reside in functionally distinct endo-lysosomal vesicles.     

Ag and O ion irradiation induced improvement in dielectric properties of the Ba(Co1/3Nb2/3)O3 thin films

We present the preliminary results of temperature and frequency dependent dielectric measurements on Ba(Co_1/3Nb_2/3)O₃ (BCN) thin films. These films were prepared on indium tin oxide (ITO) coated glass substrates by the pulse laser deposition (PLD) technique. It exhibits single-phase hexagonal symmetry. These films were irradiated with Ag¹⁵⁺ (200 MeV) and O⁷⁺ (100 MeV) beams at the fluence 1 × 10¹¹, 1 × 10¹², and 1 × 10¹³ ions/cm². On irradiating these films, its dielectric constant (?′) and dielectric loss (tan δ) parameters improve compared to un-irradiated film. Compared to O⁷⁺ irradiation induced point/cluster defects Ag¹⁵⁺ induced columnar defects are more effective in reducing/pinning trapped charges within grains. The present paper highlights the role of swift heavy ion irradiation in engineering the dielectric properties of conductive samples to enable them to be useful for microwave device applications.