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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 72 (1992), S. 3808-3815 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The possibility of replacing Pt in the Ti/Pt/Au base and traditionally used metallurgical structure by Ni, while bonding InP laser chip to a submount with AuSn (80% Au) solder, has been investigated. Various Ni-based metal alloys have been prepared by evaporation. Reflow experiments were conducted in a chamber under forming gas-controlled ambient. The Ti/Ni/AuSn system provided much longer surface local freezing duration compared to the Ti/Pt/AuSn system. Scanning electron microscopy analysis revealed a smoother surface morphology for the Ti/Ni/AuSn system after the metal refroze. Auger electron spectroscopy depth profiles indicated the formation of a Ni-Sn-Au interacted layer. The interaction took place in two steps: the first stage was the dissolution of Ni into the Au-Sn liquid followed by precipitation of a Ni-Sn-Au intermetallic compound; the second stage was a solid-state interdiffusion of Sn, Au, and Ni which occured in the interacted layer and in the original Ni layer. The latter step was a diffusion-controlled process, resulting in a very slow growth rate. Both Au and Sn reacted to form Ni alloy layers of almost equal thickness, regardless of the reaction duration (up to about 5 min). This intensive reaction, however, did not lead to full consumption of the Ti interfacial layer, which provided an excellent adhesion layer between the submount and the metallurgical structure.
    Type of Medium: Electronic Resource
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  • 2
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 850-862 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Ta2O5 is a candidate for use in metal–oxide–metal (MOM) capacitors in several areas of silicon device technology. Understanding and controlling leakage current is critical for successful implementation of this material. We have studied thermal and photoconductive charge transport processes in Ta2O5 MOM capacitors fabricated by anodization, reactive sputtering, and chemical vapor deposition. We find that the results from each of these three methods are similar if one compares films that have the same thickness and electrodes. Two types of leakage current are identified: (a) a transient current that charges the bulk states of the films and (b) a steady state activated process involving electron transport via a defect band. The transient process involves either tunneling conductivity into states near the Fermi energy or ion motion. The steady state process, seen most commonly in films 〈300 Å thick, is dominated by a large number of defects, ∼1019–1020 cm−3, located near the metal–oxide interfaces. The interior of thick Ta2O5 films has a substantially reduced number of defects. Modest heating (300–400 °C) of Ta2O5 in contact with a reactive metal electrode such as Al, Ti, or Ta results in interfacial reactions and the diffusion of defects across the thickness of the film. These experiments show that successful integration of Ta2O5 into semiconductor processing requires a better understanding of the impact of defects on the electrical characteristics and a better control of the metal–Ta2O5 interface. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The guanine nucleotide analogue, 5′-p-fluorosul-phonylbenzoyl guanosine (FSBG), can react covalently with GTP-binding proteins (G proteins). In rat brain membranes, FSBG causes a time-dependent loss of β,γ-imido[8-3H]guanosine 5′-triphosphate binding sites. Using 1 mM FSBG, the guanyl nucleotide modulation of opioid agonist binding is abolished, whereas the guanyl nucleotide sensitivity of neurotensin binding is retained. The action of FSBG can be prevented by the presence of opioid agonists, but not the antagonist naloxone. Iodoacetamide treatment of membranes in the presence of agonist, but not antagonist, can attenuate the action of FSBG in blocking guanyl nucleotide modulation of opioid agonist binding. These results suggest that FSBG covalently modifies essential thiol groups, whose exposure to the reagent is modified by agonist occupancy of the receptor, on a species of G protein linked to opioid receptors, but not on a species of G protein linked to neurotensin receptors. Thus, FSBG may have selectivity for the forms of Gi or Go, proteins associated with opioid receptors.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1471-0528
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: A single pessary containing 0·5 mg 16,16 dimethyl prostaglandin E2 p-benzaldehyde semicarbazone ester was used for cervical dilatation prior to vacuum aspiration in 124 first trimester nulliparae. Five hours after prostaglandin administration the cervix had dilated to 8 mm or more in 87 patients (70 per cent). The uterus was evacuated in these patients without mechanical dilatation of the cervix. In the remaining 37 patients the cervix had become soft and dilated 5 to 7 mm and further mechanical dilatation could be carried out easily. Side effects were minor and included vomiting in two patients, diarrhoea in one and transient pyrexia in two patients. There were no complications and no damage to the cervix or uterus during evacuation.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Clinical and experimental dermatology 29 (2004), S. 0 
    ISSN: 1365-2230
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Leukotriene E4 (LTE4) is elevated in adults with atopic dermatitis (AD). We evaluated whether urinary LTE4 as a noninvasive marker correlates with clinical indices of disease activity in children with AD. AD patients aged 18 years or younger were eligible for inclusion in the study. Disease severity over the preceding 3 days was evaluated by the SCORing Atopic Dermatitis (SCORAD) index. Severity of AD over the past 12 months was evaluated by the Nottingham Eczema Severity Score (NESS) in Chinese. Urinary LTE4 concentration was measured by competitive enzyme immunoassay. One hundred and twenty-six children with AD (82 boys and 44 girls) and 45 controls were recruited. The mean ± SD urinary log-transformed LTE4 concentration in AD patients and controls was 2.94 ± 0.32 and 2.62 ± 0.20 pg/mg creatinine, respectively (P 〈 0.0001). SCORAD significantly correlated with NESS (r = 0.681, P 〈 0.0001). There were significant correlations between urinary LTE4 concentration and overall SCORAD score (r = 0.270, P = 0.002) and its extent (r = 0.185, P = 0.038) and intensity components (r = 0.247, P = 0.005), but not with NESS. When compared with mild AD, urinary LTE4 concentrations were higher in patients with moderate-to-severe disease (P = 0.049). Urinary LTE4 measurement is noninvasive and may be useful in supplementing the SCORAD for following longitudinal changes in AD severity in children. However, the practical value of this assay in a clinical setting remains to be determined.
    Type of Medium: Electronic Resource
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  • 6
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Clinical and experimental dermatology 30 (2005), S. 0 
    ISSN: 1365-2230
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We evaluated the emollient use and bathing habits of children with atopic eczema (AE) managed at the paediatric dermatology clinic of a university teaching hospital, using children with noneczematous skin diseases as controls. Disease severity of AE in the preceding 12 months was evaluated by the Nottingham Eczema Severity Score. Three-quarters of patients with or without eczema preferred showering to bathing. Patients with AE were more likely to use bath oils than soap and to use emollients after a bath/shower. Review cases, however, were more likely to take a shower and for a longer time (10–30 min) than first-visit eczema patients. These habits did not vary with season or disease severity. Emulsifying ointment was the most commonly used agent for the bath/shower. Most patients applied emollient immediately after a bath/shower. However there were still significant proportions of AE patients who used soap (40% of first-visit vs. 27% of review cases) and who did not apply emollients after a bath/shower (25% of first-visit vs. 23% of review cases). It is important to determine whether this problem is due to inadequate patient education or whether other factors lead to poor compliance.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1365-2230
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: There are at least 13 scoring systems for the assessment of disease severity in atopic dermatitis (AD). Each system has its problems with interobserver and intraobserver variability. Cutaneous T-cell attracting chemokine (CTACK) is a skin-specific chemoattractant which may correlate with AD severity and obviate the issue of observer reliability. We evaluated whether serum CTACK concentrations were associated with the severity of AD in children according to the SCORing Atopic Dermatitis (SCORAD) index. Thirty-seven Chinese children with AD (23 boys, 14 girls; aged 1–11 years) and 13 controls were recruited. The median (interquartile range) overall SCORAD for AD patients was 29.7 (20.3–49.7). Serum concentrations of CTACK and two other atopy-related chemokines, macrophage-derived chemokine (MDC) and thymus and activation-regulated chemokine (TARC), were measured by sandwich enzyme immunoassay. There were significant correlations between SCORAD (r = 0.394, P = 0.016), its area (r = 0.528, P = 0.001) and intensity components (r = 0.429, P = 0.008) with serum levels of CTACK. The serum concentrations of inflammatory markers MDC and TARC also correlated with the CTACK concentrations (r = 0.618, P 〈 0.001, and r = 0.587, P = 0.001, respectively). Serum CTACK concentration appears to be a skin-specific objective marker that correlates with various clinical and laboratory parameters of AD.
    Type of Medium: Electronic Resource
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  • 8
    ISSN: 1520-510X
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 76 (1994), S. 4663-4669 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The influence of finite surface recombination velocity on the proper interpretation of photoconductive decay (PCD) transients in semiconductors is discussed. The limitations of simple analytical equations which relate the observed effective lifetime to the material parameters are considered. It is shown that, under most circumstances, the correct application of the appropriate analytical expression requires some prior knowledge of the material parameters under investigation. Several methods are proposed to extract useful information from PCD experiments. Finally, the practicality of these methods is investigated by measuring the effective lifetimes of high-purity germanium and float-zone silicon using a noncontact PCD technique.
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 72 (1998), S. 1308-1310 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A low temperature oxygen/nitrogen plasma process is reported that substantially reduces leakage currents in chemical vapor deposited (CVD) and physical vapor deposited (PVD) films of tantalum oxide. We show that a combination of nitrogen and oxygen in a remote downstream microwave plasma source reduces leakage currents in CVD films of tantalum oxide and also reduces trap densities as measured by charge pumping. The as deposited CVD films show a high level of photoluminescence that is substantially lowered by the plasma anneal due to a reduction in the density of midgap states. For films deposited by PVD in the thickness range of 100 nm we find low leakage currents with a substantial improvement from the introduction of nitrogen into the plasma. However, PVD films in the thickness range of 20 nm show larger relative leakage currents and less of an improvement from the addition of nitrogen. The role of nitrogen in lowering leakage currents and charge trapping is thought to occur from a reduction in the density of bulk trap states in the oxide due to partial incorporation of nitrogen in the oxide. Both of these low temperature deposition and annealing processes are compatible with integration into the upper levels of metallization for high density circuits.© 1998 American Institute of Physics.
    Type of Medium: Electronic Resource
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