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Anna Wanahita - One of the best experts on this subject based on the ideXlab platform.
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diagnostic value of microscopic examination of gram stained sputum and sputum cultures in patients with bacteremic pneumococcal pneumonia
Clinical Infectious Diseases, 2004Co-Authors: Daniel M Musher, Roberto Montoya, Anna WanahitaAbstract:Clinicians continue to question the usefulness of microscopic examination of Gram-stained sputum specimens ("Gram staining") and sputum culture for diagnosis of pneumonia. We analyzed the sensitivity of these techniques in 105 patients with pneumococcal pneumonia proven by blood culture. Gram staining revealed gram-positive cocci in pairs and chains, and culture yielded pneumococci in only 31% and 44% of all cases, respectively. However, sputum specimens were never submitted for examination in 31 cases; in 16 others, the specimen was inadequate and a culture was not done. Excluding these cases, the sensitivities of Gram staining and culture were 57% and 79%, respectively. If patients receiving antibiotics for >24 h had been excluded, Gram staining would have suggested pneumococci in 63%, and culture results would have been positive in 86%. Sensitivity increased in Inverse Proportion to the duration of antibiotic therapy (P 80% of cases of pneumococcal pneumonia.
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diagnostic value of microscopic examination of gram stained sputum and sputum cultures in patients with bacteremic pneumococcal pneumonia
Clinical Infectious Diseases, 2004Co-Authors: Daniel M Musher, Roberto Montoya, Anna WanahitaAbstract:Clinicians continue to question the usefulness of microscopic examination of Gram-stained sputum specimens (“Gram staining”) and sputum culture for diagnosis of pneumonia. We analyzed the sensitivity of these techniques in 105 patients with pneumococcal pneumonia proven by blood culture. Gram staining revealed gram-positive cocci in pairs and chains, and culture yielded pneumococci in only 31% and 44% of all cases, respectively. However, sputum specimens were never submitted for examination in 31 cases; in 16 others, the specimen was inadequate and a culture was not done. Excluding these cases, the sensitivities of Gram staining and culture were 57% and 79%, respectively. If patients receiving antibiotics for 124 h had been excluded, Gram staining would have suggested pneumococci in 63%, and culture results would have been positive in 86%. Sensitivity increased in Inverse Proportion to the duration of antibiotic therapy ( ). Microscopic P ! .05 examination of sputum samples before antibiotics were administered and performance of culture within 24 h of receipt of such treatment yielded the correct diagnosis in 180% of cases of pneumococcal pneumonia.
Daniel M Musher - One of the best experts on this subject based on the ideXlab platform.
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diagnostic value of microscopic examination of gram stained sputum and sputum cultures in patients with bacteremic pneumococcal pneumonia
Clinical Infectious Diseases, 2004Co-Authors: Daniel M Musher, Roberto Montoya, Anna WanahitaAbstract:Clinicians continue to question the usefulness of microscopic examination of Gram-stained sputum specimens ("Gram staining") and sputum culture for diagnosis of pneumonia. We analyzed the sensitivity of these techniques in 105 patients with pneumococcal pneumonia proven by blood culture. Gram staining revealed gram-positive cocci in pairs and chains, and culture yielded pneumococci in only 31% and 44% of all cases, respectively. However, sputum specimens were never submitted for examination in 31 cases; in 16 others, the specimen was inadequate and a culture was not done. Excluding these cases, the sensitivities of Gram staining and culture were 57% and 79%, respectively. If patients receiving antibiotics for >24 h had been excluded, Gram staining would have suggested pneumococci in 63%, and culture results would have been positive in 86%. Sensitivity increased in Inverse Proportion to the duration of antibiotic therapy (P 80% of cases of pneumococcal pneumonia.
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diagnostic value of microscopic examination of gram stained sputum and sputum cultures in patients with bacteremic pneumococcal pneumonia
Clinical Infectious Diseases, 2004Co-Authors: Daniel M Musher, Roberto Montoya, Anna WanahitaAbstract:Clinicians continue to question the usefulness of microscopic examination of Gram-stained sputum specimens (“Gram staining”) and sputum culture for diagnosis of pneumonia. We analyzed the sensitivity of these techniques in 105 patients with pneumococcal pneumonia proven by blood culture. Gram staining revealed gram-positive cocci in pairs and chains, and culture yielded pneumococci in only 31% and 44% of all cases, respectively. However, sputum specimens were never submitted for examination in 31 cases; in 16 others, the specimen was inadequate and a culture was not done. Excluding these cases, the sensitivities of Gram staining and culture were 57% and 79%, respectively. If patients receiving antibiotics for 124 h had been excluded, Gram staining would have suggested pneumococci in 63%, and culture results would have been positive in 86%. Sensitivity increased in Inverse Proportion to the duration of antibiotic therapy ( ). Microscopic P ! .05 examination of sputum samples before antibiotics were administered and performance of culture within 24 h of receipt of such treatment yielded the correct diagnosis in 180% of cases of pneumococcal pneumonia.
Roberto Montoya - One of the best experts on this subject based on the ideXlab platform.
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diagnostic value of microscopic examination of gram stained sputum and sputum cultures in patients with bacteremic pneumococcal pneumonia
Clinical Infectious Diseases, 2004Co-Authors: Daniel M Musher, Roberto Montoya, Anna WanahitaAbstract:Clinicians continue to question the usefulness of microscopic examination of Gram-stained sputum specimens ("Gram staining") and sputum culture for diagnosis of pneumonia. We analyzed the sensitivity of these techniques in 105 patients with pneumococcal pneumonia proven by blood culture. Gram staining revealed gram-positive cocci in pairs and chains, and culture yielded pneumococci in only 31% and 44% of all cases, respectively. However, sputum specimens were never submitted for examination in 31 cases; in 16 others, the specimen was inadequate and a culture was not done. Excluding these cases, the sensitivities of Gram staining and culture were 57% and 79%, respectively. If patients receiving antibiotics for >24 h had been excluded, Gram staining would have suggested pneumococci in 63%, and culture results would have been positive in 86%. Sensitivity increased in Inverse Proportion to the duration of antibiotic therapy (P 80% of cases of pneumococcal pneumonia.
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diagnostic value of microscopic examination of gram stained sputum and sputum cultures in patients with bacteremic pneumococcal pneumonia
Clinical Infectious Diseases, 2004Co-Authors: Daniel M Musher, Roberto Montoya, Anna WanahitaAbstract:Clinicians continue to question the usefulness of microscopic examination of Gram-stained sputum specimens (“Gram staining”) and sputum culture for diagnosis of pneumonia. We analyzed the sensitivity of these techniques in 105 patients with pneumococcal pneumonia proven by blood culture. Gram staining revealed gram-positive cocci in pairs and chains, and culture yielded pneumococci in only 31% and 44% of all cases, respectively. However, sputum specimens were never submitted for examination in 31 cases; in 16 others, the specimen was inadequate and a culture was not done. Excluding these cases, the sensitivities of Gram staining and culture were 57% and 79%, respectively. If patients receiving antibiotics for 124 h had been excluded, Gram staining would have suggested pneumococci in 63%, and culture results would have been positive in 86%. Sensitivity increased in Inverse Proportion to the duration of antibiotic therapy ( ). Microscopic P ! .05 examination of sputum samples before antibiotics were administered and performance of culture within 24 h of receipt of such treatment yielded the correct diagnosis in 180% of cases of pneumococcal pneumonia.
H Iwai - One of the best experts on this subject based on the ideXlab platform.
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1 5 nm direct tunneling gate oxide si mosfet s
IEEE Transactions on Electron Devices, 1996Co-Authors: Hiroki Sasaki, Mizuki Ono, T Yoshitomi, T Ohguro, S Nakamura, M Saito, H IwaiAbstract:In this paper, normal operation of a MOSFET with an ultra-thin direct-tunneling gate oxide is reported for the first time. These high current drive n-MOSFET's were fabricated with a 1.5 nm direct-tunneling gate oxide. They operate well at gate lengths of around 0.1 /spl mu/m, because the gate leakage current falls in Proportional to the gate length, while the drain current increases in Inverse Proportion. A current drive of more than 1.0 mA//spl mu/m and a transconductance of more than 1,000 mS/mm were obtained at a gate length of 0.09 /spl mu/m at room temperature. These are the highest values ever obtained with Si MOSFET's at room temperature. Further, hot-carrier reliability is shown to improve as the thickness of the gate oxide is reduced, even in the 1.5 nm case. This work clarifies that excellent performance-a transconductance of over 1,000 mS/mm at room temperature-can be obtained with Si MOSFET's if a high-capacitance gate insulator is used.
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tunneling gate oxide approach to ultra high current drive in small geometry mosfets
International Electron Devices Meeting, 1994Co-Authors: H S Momose, Mizuki Ono, T Yoshitomi, T Ohguro, S Nakamura, M Saito, H IwaiAbstract:Ultra-high performance n-MOSFETs were fabricated with a tunneling gate oxide 1.5 nm thick. It was found that these devices operate well when the gate length is around 0.1 /spl mu/m, because gate leakage current falls in Proportion to the gate length and the drain current increases in Inverse Proportion. A very high drivability of 1.1 mAspl mu/m at 15 V was obtained, even in devices with a 0.14 pm gate length. A record high transconductance, 1,010 mS/mm at room temperature was also obtained in 0.09 /spl mu/m MOSFETs. Confirmation was obtained that hot-carrier reliability improves as the gate oxide thickness is reduced, even in the 1.5 nm case. High current drive at the low supply voltage of 0.5 V was also demonstrated. We made clear that very high performance is obtained in Si MOSFETs, if we can use a high capacitance gate insulator. In future devices, the tunnel gate oxide may be a good candidate for such a gate film, depending upon their applications. >
Jyrki Rovamo - One of the best experts on this subject based on the ideXlab platform.
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flicker sensitivity as a function of spectral density of external white temporal noise
Vision Research, 1996Co-Authors: Jyrki Rovamo, Antti Raninen, S Lukkarinen, Kristian DonnerAbstract:Abstract Foveal flicker sensitivity at 0.5–30 Hz was measured as a function of the spectral density of external, white, purely temporal noise for a sharp-edged 2.5 deg circular spot (mean luminance 3.4 log phot td). Sensitivity at any given temporal frequency was constant at low powers of external noise, but then decreased in Inverse Proportion to the square root of noise spectral density. Without external noise, sensitivity as function of temporal frequency had the well-known band-pass characteristics peaking at about 10 Hz, as previously documented in a large number of studies. In the presence of strong external noise, however, sensitivity was a monotonically decreasing function of temporal frequency. Our data are well described (goodness of fit 90%) by a model comprising (i) low-pass filtering by retinal cones, (ii) high-pass filtering in the subsequent neural pathways, (iii) adding of the temporal equivalent of internal white spatiotemporal noise, and (iv) detection by a temporal matched filter, the efficiency of which decreases approximately as the power −0.58 of temporal frequency. Copyright © 1996 Elsevier Science Ltd
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effects of colour adaptation and stimulus size on the detection of chromatic deviations from achromatic as a function of eccentricity in man
Ophthalmic and Physiological Optics, 1994Co-Authors: Antti Iivanainen, Jyrki RovamoAbstract:By using constant size and M-scaled stimuli (the stimulus size was magnified towards the visual field periphery in Inverse Proportion to the lowest local sampling density of the human retina) we measured the thresholds for perceiving the complementary colours of blue, green and red (i.e. yellow, purple or blue-green) under chromatic adaptation at the eccentricities of 0-15 degrees in the nasal visual field. The CIE 1931 (x, y) chromaticity coordinates corresponding to complementary hue perception were subtracted from the chromaticity coordinates of achromatic threshold. The difference was found to be constant irrespective of stimulus size and eccentricity. This means that the perception of chromatic deviation from achromatic under chromatic adaptation is independent of stimulus size and eccentricity.
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modelling contrast sensitivity as a function of retinal illuminance and grating area
Vision Research, 1994Co-Authors: Jyrki Rovamo, Juvi Mustonen, Risto NasanenAbstract:We extended the contrast detection model of human vision [Rovamo, Luntinen & Nasanen (1993b) Vision Research, 33, 2773–2788] to low light levels by taking into account the effect of light-dependent quantal noise. The extended model comprises (i) low-pass filtering due to the optical modulation transfer function of the eye, (ii) addition of light-dependent noise at the event of quantal absorption, (iii) high-pass filtering of neural origin (lateral inhibition), (iv) addition of internal neural noise, (v) detection by a local matched filter whose efficiency decreases with increasing grating area. To test the model we measured foveal contrast sensitivity as a function of retinal illuminance and grating area at spatial frequencies of 0.125–32 c/deg. In agreement with the model, monocular contrast sensitivity at all grating areas increased in Proportion to √I when retinal illuminance (I) was smaller than critical illuminance. Thereafter the increase saturated and contrast sensitivity became independent of retinal illuminance. Similarly, at all levels of retinal illuminance contrast sensitivity increased in Proportion to √A when grating area (A) was smaller than critical area. Thereafter the increase saturated and contrast sensitivity became independent of area. Critical level of retinal illuminance increased in Proportion to the spatial frequency squared. Critical area marking the saturation of spatial integration was constant at low spatial frequencies but decreased in Inverse Proportion to spatial frequency squared at medium and high spatial frequencies. The maximum contrast sensitivity obtainable by spatial integration in bright light increased at low spatial frequencies in Proportion to spatial frequency, was constant at medium spatial frequencies, and decreased in Inverse Proportion to spatial frequency cubed at high spatial frequencies. The increase was due to the neural modulation transfer function of the visual pathways whereas the decrease was due to the optical modulation transfer function of the eye. The model explained 91–99% of the total variance of our contrast sensitivity data at various spatial frequencies.
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the effects of grating area and spatial frequency on contrast sensitivity as a function of light level
Vision Research, 1993Co-Authors: Juvi Mustonen, Jyrki Rovamo, Risto NasanenAbstract:Contrast sensitivity was measured as a function of retinal illuminance (I) for vertical cosine gratings of various circular areas (A) and spatial frequencies (f ⩽ 4 c/deg). Spatial frequency and grating diameter varied in Inverse Proportion to each other in order to keep the relative grating area (A × f2) constant at either 3.14,12.6, 50.3, or 201 square cycles. At all grating areas and spatial frequencies contrast sensitivity in dim light first increased in Proportion to the square root of retinal illuminance. Then the increase saturated and contrast sensitivity became independent of luminance level in bright light. For gratings with constant relative area contrast sensitivity functions were similar in shape and had the same maximum sensitivity but were shifted horizontally towards lower illuminances with decreasing spatial frequency. However, when replotted as a function of retinal illuminance divided by spatial frequency squared, contrast sensitivity functions fell on a common curve at all levels of relative retinal illuminance (I/f2).
