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  • 1
    Electronic Resource
    Electronic Resource
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 89 (2001), S. 859-868 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Simultaneous measurement of the absolute optical absorption coefficient or species concentration, thermal diffusivity, and flow velocity in a gaseous medium has been demonstrated by using pulsed photothermal deflection spectroscopy (PTDS) and a multiparameter fitting procedure. The spatial distribution of the three parameters in a laminar flow has been simultaneously determined and the influence of velocity gradient on the measurement has been discussed. Saturation behavior of the PTDS signals was observed and found to influence significantly the fitted results. The saturation influences most significantly the absorption coefficient determination, somewhat less significantly the thermal diffusivity determination, and only negligibly the flow velocity determination. For an absolute and accurate measurement of the absorption coefficient or species concentration, the saturation-induced error has to be corrected by using a model taking into account the effects of the saturation. The influence of saturation on the thermal diffusivity determination can be significantly accounted for by using a simple model in which the pump beam radius is set as a free parameter in the multiparameter fitting procedure. Both multipulse and single-pulse measurements are performed. For multipulse measurement, the estimated measurement uncertainties are ±2% for the flow velocity, and ±5% for the thermal diffusivity and absorption coefficient, while for single-pulse measurement, the estimated uncertainties are ±2% and ±10%, respectively. © 2001 American Institute of Physics.
    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. 5515-5526 
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: A two-level transient-state model has been developed which describes the effect of optical saturation on the photothermal signals, valid for conditions where a steady state may not exist. The theory is quite general, as it considers arbitrary pulse shapes, homogeneously and inhomogeneously broadened lines, and arbitrary spectral profile of the excitation. Equations for the temporally and spatially dependent absorption coefficient are derived, and, for generality, time-dependent photothermal deflection signals in a flowing medium are calculated (stationary medium being just a special case). The saturation behaviors of the photothermal signals obtained by monochromatic rectangular and Q-switched pulse excitations for homogeneously and inhomogeneously broadened lines are evaluated and compared. Differences between the predictions of the steady-state and transient-state models are discussed. Experiments have been performed using NO2 as a sample gas in a flowing medium. The experimental results are in agreement with the predictions of the transient state model. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 3
    Electronic Resource
    Electronic Resource
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 4136-4138 
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Thin films (9 μm) of polyvinylidene fluoride (PVDF) are irradiated by swift heavy ions (180 MeV Ag14+) in the fluence range 1×1010–1×1012ions/cm2 with an electronic linear energy transfer LET∼11 keV/nm. In sharp contrast to the previous results, the most characteristic crystalline asymmetric and symmetric "CH2" doublets (located at 3025 and 2985 cm−1), have shown remarkable increase in their respective Fourier transform infrared (FTIR) absorbance intensities upon low fluence ion impact (1010 ions/cm2). This increase in absorbance is in consonance with the simultaneous decrease of the transmission intensities of other crystalline bending vibration bands located at 532 (CF2 bending), 614, 796, and 975 cm−1 (all due to CH2 bending) at the similar ion fluence. It appears most probable from the results that, being a polar polymer, the molecular dipoles in PVDF forming a hydrogen bond network get realigned upon irradiation into a highly ordered state of chain molecules in the crystalline regions and create volume elements as crystallites. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
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  • 4
    ISSN: 1365-2303
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: In this study the features of small cell malignancies found in the liver by fine needle aspiration cytology (FNAC) and immunostains required for a diagnosis and differential diagnosis are presented. The material consisted of 197 fine needle aspirates which were performed under image guidance between January 1982 to October 1999. Of these, 30 were diagnosed as small cell malignancies. The age of patients ranged between 46 and 68 years. The aspirated material was examined using Papanicolaou-stained filter preparations and cell blocks, the latter stained with hematoxylin and eosin and a panel of immunoperoxidase stains. The diagnoses based on a correlation of relevant clinical history, cytohistological findings and immunostaining were: metastatic small cell anaplastic carcinoma of lung (n = 6); neuroendocrine tumour (n = 9); non-Hodgkin's lymphoma (n = 4); well-differentiated cholangiocarcinoma (n = 2); metastatic carcinoma of the prostate (n = 2); metastatic adenocarcinoma (n = 4) and metastatic carcinoma breast (n = 3). This study emphasizes the wide range of neoplasms that enter into the differential diagnosis of small cell malignancies found in the liver and a correlation of clinical, cytohistological and immunostaining findings which seem to be useful in suggesting a diagnosis.
    Type of Medium: Electronic Resource
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  • 5
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Cytopathology 11 (2000), S. 0 
    ISSN: 1365-2303
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Secretory carcinoma (SC) of the breast is a rare variant of breast malignancy and its cytological features in fine needle aspirates have only recently been described. In this communication, our experience with four cases of SC of the breast is presented in which the diagnosis was established on fine needle aspiration cytology (FNAC). In all cases, the samples were cellular and featured diffuse, prominent, intracytoplasmic vacuoles and secretion in malignant cells and occasional signet-ring like forms. The cytodiagnosis of SC in all the cases correlated with subsequent examination of cell blocks of the aspirate and tissue. Cytochemical stains showed diffuse positivity for mucin by alcian blue stain in the vacuolated cells which was periodic acid–Schiff positive and resistant to diastase digestion. Oil-red O staining was negative. Immunopositivity to carcinoembryonic antigen, cytokeratin (CAM 5.2), B72.3 and epithelial membrane antigen was found in malignant cells. The cytodiagnostic criteria for SC of the breast, characteristic cytological features which are useful in a correct FNAC diagnosis and differentiation from other pertinent breast carcinomas, are discussed.
    Type of Medium: Electronic Resource
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  • 6
    ISSN: 1365-2303
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: The aim of this study was to evaluate the diagnostic value of fine needle aspiration cytology (FNAC) in the assessment of palpable supraclavicular lymph nodes. The material was analysed in 218 cases with enlarged supraclavicular lymph nodes in which FNAC was performed by the conventional method. In all cases cytological examination was performed on-site after staining the smears by the Papanicolaou method. In addition, air-dried smears, fixed smears, filter preparations from needle washings and cell blocks were studied. The FNAC diagnosis was supported by examining cell blocks which added the reliability of histological architecture; further support was obtained by tissue biopsy and/or comparison with the primary tumour in some of the cases. Eleven cases were diagnosed as inflammatory lesions and 41 cases were unsatisfactory because of scanty/acellular samples (despite two to three repeat samplings). However, in five of these, malignant tumours were later found on biopsy, which was done for persistent enlargement of the supraclavicular lymph node(s). Fifty-three cases were diagnosed as negative for malignancy (normal cellular elements, n = 15; reactive elements, n = 38) and 12 cases were suspicious of malignancy. In 11 cases a diagnosis of lymphoma was made on histology and in 90 cases metastatic tumours were diagnosed. The overall sensitivity was 92.7%, specificity 98.5%, positive predictive value 97.3% and the negative predictive value was 94.8%. Based on our study we feel that FNAC of palpable supraclavicular lymph nodes as a first line of investigation is a cost-effective procedure and is not only useful in the diagnosis of various lesions but can also help in deciding on appropriate management. Furthermore, the histological architecture from cell blocks can be correlated with cytology, and such material can be used for appropriate histochemical and immunomarker studies, which can be useful in enhancing the diagnosis.
    Type of Medium: Electronic Resource
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  • 7
    ISSN: 1365-2303
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Pericardial effusions are not uncommon in patients with an advanced malignancy. Rarely malignancies may present initially with a pericardial effusion. Cytological examination of pericardial fluid may be valuable in differentiation of these cases. However, a metastatic tumour in serous effusion may not always show the functional differentiation of the primary tumour. In such a situation, although a wide range of special studies have been suggested for the diagnosis of malignancy we have found the use of a panel of a few common immunostains to be useful in confirming or suggesting the site of a primary tumour. The material for this study consisted of 76 pericardial fluids obtained between January 1991 and October 1998 from 46 males (mean age 59 years) and 30 females (mean age 52 years). Metastatic malignancy was diagnosed in 22 of the 76 patients and in 7/22 cases pericardial effusions were the initial presentation. The subsequent follow-up in the seven cases revealed adenocarcinoma of lung (n = 2), small cell anaplastic carcinoma of lung (n = 1), squamous cell carcinoma lung (n = 1), melanoma leg (n = 1), non-Hodgkin’s lymphoma retroperitoneal lymph nodes (n = 1) and carcinoma of the breast (n = 1). Of the remaining 15 cases with a known history of malignancy, eight had cancers (three adeno; two small cell; one poorly differentiated, and two squamous cell types) of the lung; breast (n = 3); colon (n = 1); melanoma (n = 2) and non Hodgkin’s lymphoma (n = 1). Immunostains which were useful in the diagnosis were EMA, CEA, cytokeratin, B72.3, HMB45, vimentin, S100, LCA, L26 and kappa and lambda light chains.
    Type of Medium: Electronic Resource
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  • 8
    Electronic Resource
    Electronic Resource
    Oxford, UK : Blackwell Science Ltd
    Cytopathology 11 (2000), S. 0 
    ISSN: 1365-2303
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Type of Medium: Electronic Resource
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  • 9
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of natural products 47 (1984), S. 901-901 
    ISSN: 1520-6025
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
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  • 10
    Electronic Resource
    Electronic Resource
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Biophysics and Biomolecular Structure 13 (1984), S. 221-246 
    ISSN: 0084-6589
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology , Physics
    Type of Medium: Electronic Resource
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