Library

X
feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    Evaluation of five commercial serological tests for the detection of Helicobacter pylori infection in Chinese (2001)
    Oxford UK : Blackwell Science Ltd
    Alimentary pharmacology & therapeutics 15 (2001), S. 0 
    Details
    ISSN: 1365-2036
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Commercial serological tests for the detection of Helicobacter pylori infection must be locally validated. We evaluated the accuracy of five commercial tests in the Chinese population.〈section xml:id="abs1-2"〉〈title type="main"〉Methods:Serum samples were collected from patients referred for upper endoscopy. Antral biopsies were taken for histological examination and culture of H. pylori. The gold standard for diagnosing H. pylori infection was positive histological staining and/or positive H. pylori culture. The serum samples were tested for H. pylori antibodies using the following tests: (i) Cobas Core Anti-H. pylori EIA; (ii) GAP IgG; (iii) GAP IgM; (iv) H. pylori microwell EIA (Quidel); and (v) Premier H. pylori. The sensitivity, specificity and accuracy of each test was calculated according to the manufacturers’ instructions or according to a new cut-off value.〈section xml:id="abs1-3"〉〈title type="main"〉Results:A total of 158 patients were recruited amongst whom 114 (72%) were H. pylori-positive. Indeterminate results varied from 7% to 19%. The accuracy of the tests varied from 57% to 85%. By using new cut-off values, the accuracy was much improved, ranging from 73.4% to 86.7%.〈section xml:id="abs1-4"〉〈title type="main"〉Conclusions:By defining new cut-off values for the Chinese population, we were able to improve the performance of some of the serology tests. This illustrates the importance of local validation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2036.2001.00961.x
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    The electronic structures and properties of Alq3 and NPB molecules in organic light emitting devices: Decompositions of density of states (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 8614-8620 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: A decomposition treatment of density of states in combination with PM3 molecular orbital calculations was used to reveal the fingerprints of electronic structures of two prototypical electroluminescent molecules, tris(8-hydroxy-quinoline)aluminum (Alq3) and N,N′-bis(1-naphthyl)-N,N′-diphenyl-1,1′-biphenyl-4,4′-diamine (NPB). High convenience and accuracy of such a treatment were found for these large organic molecules in the determinations of (1) the distribution of important molecular orbitals such as the highest occupied orbital and the lowest unoccupied orbital; (2) the contribution to valence and conduction bands as well as gap states from constituent atoms, and thus the attribution of ultraviolet photoemission spectrum; (3) the sites and properties of reaction and excitation of a molecule; and (4) the localization property of electronic states. In particular, this study indicates that Alq3 is most possibly attacked by other atoms at the oxygen atoms while the reaction site for NPB is at the nitrogen atom. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481462
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 3
    Electronic Resource
    Electronic Resource
    Optical properties and structure of tellurium–germanium– bismuth–antimony compounds with fast phase-change capability (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 3290-3294 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Quaternary TeGeBiSb amorphous films, 100 nm in thickness, were prepared by rf sputtering onto either a Si (100) or polycarbonate substrate. Crystalline films were obtained by subsequent annealing at 300 °C for 10 min. At least two phases with hexagonal and rhombohedral structures were identified by x-ray diffractometry in the quaternary system. Their compositions are close to formulas Te5Ge4Bi4Sb and Te5Ge4Bi7Sb, with c/a ratios of 5.5 and 9.4, respectively. The Te5Ge4Bi4Sb film shows a reasonable reflectivity contrast ranging from 20% to 25% in the whole visible spectrum, while the reflectivity contrast of Te5Ge4Bi7Sb film shows a sharp lowering tendency with decreasing wavelength and turns negative at wavelengths smaller than 470 nm. Results of thermal analyses show that the films crystallize at around 236–266 °C with corresponding activation energies 2.67–2.88 eV. The change in reflectivity contrast is explained based on the variation in optical band gaps of the TeGeBiSb materials with either Bi content or annealing temperature. These materials may find applicability in reversible type phase-change optical recording. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1348327
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 4
    Electronic Resource
    Electronic Resource
    Time-resolved photoluminescence study of InGaAs/GaAs quantum wells on (111)B GaAs substrates under magnetic fields (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 7875-7878 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The exciton dynamics in InxGa1−xAs/GaAs quantum wells grown on (111)B and (100) GaAs substrates were studied by time-resolved photoluminescence (PL) under magnetic fields in a Faraday configuration. We have found that the piezoelectric fields in (111)B samples affect the transient behavior of the PL spectra. Compared with the reference (100) sample, we have found that the strong piezoelectric fields, as well as the magnetic fields, cause a slower spin–flip process in (111)B strained quantum wells. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1376401
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 5
    Electronic Resource
    Electronic Resource
    Bulk-quantity Si nanosphere chains prepared from semi-infinite length Si nanowires (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 727-731 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Bulk-quantity Si nanosphere chains have been fabricated. This is accomplished via the spheroidization of Si nanowires of semi-infinite lengths. The process has been extensively investigated by transmission electron microscopy. The nanosphere chains consisted of equally spaced Si crystalline nanospheres connected by Si-oxide bars. The transition from Si nanowires to Si nanosphere chains was determined by the annealing temperature, ambient pressure, initial Si nanowire diameters, and the oxide state of the outer layers of Si nanowires. The relationships between the geometry (size and spacing) of Si nanospheres, the initial state (diameter and oxide state) of Si nanowires, and the experimental conditions are discussed. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1328786
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 6
    Electronic Resource
    Electronic Resource
    Crystal morphology and phase purity of diamond crystallites during bias enhanced nucleation and initial growth stages (2000)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 88 (2000), S. 3354-3360 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The crystal morphologies and phase composition of diamond crystallites during bias enhanced nucleation and initial growth stages in microwave plasma chemical vapor deposition were investigated. Diamond nuclei were first formed in the central regions of substrates and then propagated to the sample edges. During the course of bias nucleation, excessive ion bombardment induced secondary nucleation sites on the already formed nuclei. The secondary nucleation deteriorated the overall alignment of the growing crystals. Hence, the elimination of secondary nucleation and homogeneous nucleation over substrates are fundamental requirements for the deposition of large-area uniformly oriented diamond films. Decreasing reactant pressure was found to be effective for improving plasma homogeneity and consequently nucleation uniformity. The results of bias enhanced nucleation within a pressure range from 8 to 20 Torr showed that the lower pressure of reactants enlarged the area of oriented diamond films. However, the optimum bias and duration of nucleation was found to be specific for each pressure. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1289071
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 7
    Electronic Resource
    Electronic Resource
    Nuclear diagnostics for the National Ignition Facility (invited) : Papers from the thirteenth topical conference on high temperature plasma diagnostics (2001)
    [S.l.] : American Institute of Physics (AIP)
    Review of Scientific Instruments 72 (2001), S. 773-779 
    Details
    ISSN: 1089-7623
    Source: AIP Digital Archive
    Topics: Physics , Electrical Engineering, Measurement and Control Technology
    Notes: The National Ignition Facility (NIF), currently under construction at the Lawrence Livermore National Laboratory, will provide unprecedented opportunities for the use of nuclear diagnostics in inertial confinement fusion experiments. The completed facility will provide 2 MJ of laser energy for driving targets, compared to the approximately 40 kJ that was available on Nova and the approximately 30 kJ available on Omega. Ignited NIF targets are anticipated to produce up to 1019 DT neutrons. In addition to a basic set of nuclear diagnostics based on previous experience, these higher NIF yields are expected to allow innovative nuclear diagnostic techniques to be utilized, such as neutron imaging, recoil proton techniques, and gamma-ray-based reaction history measurements. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1319356
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 8
    Electronic Resource
    Electronic Resource
    Study of copper silicide retardation effects on copper diffusion in silicon (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 3822-3824 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A B-buried layer with a dose of 1×1014 atoms/cm2 was introduced into p-doped Si at a depth of 2.2 μm to enhance copper diffusion via its inherent gettering effect. Copper was then introduced into silicon either via a low-energy implantation followed by a thermal anneal, or through the thermal drive in of physical vapor deposited (PVD) copper film. Secondary ion mass spectrometry depth profiling of both annealed samples later indicated that while substantial amounts of copper was gettered by the B layer in the former sample, no copper was gettered by the B-buried layer in the latter sample. Further analysis with an x-ray diffraction technique showed that copper silicide, Cu3Si was formed in the latter sample. It is thus surmised that the formation of this silicide layer impeded the diffusion of copper towards the B-buried layer. This work investigates the cause of CuSix formation and the underlying reasons for the lower mobility of Cu in PVD Cu film samples. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1343518
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 9
    Electronic Resource
    Electronic Resource
    Hole Schottky barrier height enhancement and its application to metal–semiconductor–metal photodetectors (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 90 (2001), S. 5666-5669 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Hole Schottky barrier heights on GaAs have been studied experimentally by using a conventional metal–semiconductor–metal photodetector (MSMPD) structure. The Schottky barrier height for holes was obtained directly by the hole-current dominated dark current measurement of the MSMPD. With a thin, highly doped surface layer, control of the Schottky barrier heights for holes from 0.48 to 0.79 eV was obtained. By using these engineered Schottky contacts in the MSMPDs, over three orders of magnitude reduction in the dark currents of the MSMPDs was achieved. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1415060
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 10
    Electronic Resource
    Electronic Resource
    Surface reactivity of Si nanowires (2001)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 6396-6399 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: The chemical reactivity of hydrogen-passivated surface of silicon nanowires (SiNWs) towards the reductive deposition of silver and copper ions from solution is reported. SiNWs synthesized by laser ablation were used in the investigation. The surface properties of SiNWs after the removal of the surface oxide were studied. It is found that the surface silicon of the SiNWs can readily reduce silver (I) and copper (II) ions to metal aggregates of various morphologies on the SiNW surface at room temperature. The reaction products have been characterized with scanning electron microscopy, energy dispersive x-ray spectroscopy, high-resolution transmission electron microscopy, electron energy loss spectroscopy, and x-ray photoelectron spectroscopy. By varying the concentration of Ag(I) ions in the solution, nanostructures of silver with different shapes and sizes can be obtained. This approach for synthesis of metal nanostructures offers a potential method for the preparation of desired metal catalysts. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1367402
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...