Sum Of Intensities Research Articles

Cyclooxygenase-2 expression: Does it have a probable role in tumorigenesis mechanisms of renal cell carcinoma?

The purpose of this study was to evaluate the correlation between the levels of cyclooxygenase-2 (COX-2) expression with clinicopathologic features and determine the impact on prognosis in patients with renal cell carcinoma (RCC). Expression of COX-2 was evaluated immunohistochemically in RCC tissues from 62 patients who underwent radical nephrectomy between 1996 and 2004. Percentage of COX-2 staining was scored as 0 (negative), 1 (1-24%), 2 (25-49%), 3 (50-74%), and 4 (75-100%). Immunohistochemical COX-2 staining score (ISS) was defined as summation of intensity and percentage of COX-2 staining. Twenty-seven patients (43.5%) with a median follow-up of 47.8 (25-115) months stained positively for COX-2. COX-2 expression was positive in 37.1%, 50%, and 66.7% of patients with stages 1, 2, and 3, respectively (P = 0.46). Correlation between ISS and pathological stage was statistically significant (P = 0.005). Multivariate regression analysis revealed no clinicopathologic parameter as independent predictors of progression. Kaplan-Meier analysis revealed statistically significant different survival rates in tumor stage, grade, and ISS. Although COX-2 expression is not an independent predictor of progression in patients with RCC, patients with higher ISS values have significantly shorter progression-free survival rates. These results might be important to the clinician because positive COX-2 expression of a certain RCC might necessitate early adjuvant systemic therapy to delay the progression of RCC. For this reason, there is a need for innovative, prospective, and randomized studies in patients with positive COX-2 expression that will display the impact of systemic therapies in these patients.

공기희석관능법과 기기분석법에 기초한 악취감지기술의 연계성 비교: 산단지역 및 음식물 부패시료를 중심으로

In this study, we attempted to evaluate the relationship between air dilution sensory test and instrumental detection method for individual odorous compound. For the purpose of our comparative study, we conducted the analysis of malodor on total of 46 samples collected from both industrial and food waste sectors using the two independent approaches. The results of instrumental analyses were explained after modification to several parameters such as: the sum of odor concentration (SOC), sum of odor quotient (SOQ) and sum of odor intensity (SOI). When we compared dilution ratio values (DRV) of threshold limit (TL) with the modified instrumental data sets, pearson coefficient of SOC, SOQ, and SOI were 0.556 (p=5.83E-05), 0.911 (p=9.64E-19) and 0.847 (p=8.93E-14), respectively. The results of this study thus suggest that the DRV of TL sensitively reflects odor strength measured intuitive.

A fast rendering method for clouds illuminated by lightning taking into account multiple scattering

Methods for rendering natural scenes are used in many applications such as virtual reality, computer games, and flight simulators. In this paper, we focus on the rendering of outdoor scenes that include clouds and lightning. In such scenes, the intensity at a point in the clouds has to be calculated by taking into account the illumination due to lightning. The multiple scattering of light inside clouds is an important factor when creating realistic images. However, the computation of multiple scattering is very time-consuming. To address this problem, this paper proposes a fast method for rendering clouds that are illuminated by lightning. The proposed method consists of two processes. First, basis intensities are prepared in a preprocess step. The basis intensities are the intensities at points in the clouds that are illuminated by a set of point light sources. In this precomputation, both the direct light and also indirect light (i.e., multiple scattering) are taken into account. In the rendering process, the intensities of clouds are calculated in real-time by using the weighted sum of the basis intensities. A further increase in speed is achieved by using a wavelet transformation. Our method achieves the real-time rendering of realistic clouds illuminated by lightning.

SU‐FF‐I‐32: Effects of Scatter in Dual‐Source CT

Purpose: To investigate the magnitude and distribution of scatter for dual‐source CT (DSCT) and its impact on image quality. Materials and Methods: Apart from forward scatter which is given for all CT scanners, the measurements at a dual‐source system is also affected by cross scattered photons from the second tube‐detector system arranged at 90°.Simulations and measurements of homogenous phantoms of increasing diameter (100–400 mm) and of anthropomorphic phantoms were conducted for a DSCT scanner (SOMATOM Definition, Siemens Medical Solutions, Forchheim, Germany). The simulations of both forward and cross scatter were carried out using combined analytical and Monte Carlo simulation methods using a collimation of 19.2 mm for both tube‐detector systems. Measurements of cross scatter were performed by switching one tube off, still reading out the corresponding detector. Cross scatter was evaluated with respect to anthropomorphic and homogeneous phantoms for different imaging conditions such as different tube voltages, bow—tie filters. Dual‐energy scanning was included in the evaluations. Results: The forward scatter fraction increased with increasing diameter to 10% for a PMMA phantom of 400 mm diameter; for cross scatter, the mean intensity was lower or equivalent to forward scatter for small phantoms but was larger for increased phantom diameters. For large objects the ratio of cross scatter intensity to the sum of primary signal and forward scatter intensity reaches values higher than 100%. The outer dimensions of the object appear to be decisive for cross‐scatter whereas the influence of phantom inhomogeneity appears to be negligible. For dual energy — dual source scan modes the tube current setting for each tube should be adapted to achieve a minimization of cross scatter. Conclusion: The cross scatter magnitude is non‐negligible for a DSCT system and a compensation of its contribution is necessary for the assurance of high image quality.

Spatial XRF distribution characteristics associated with polarized EDXRF spectrometry

AbstractAn experiment was designed and carried out to measure the XRF yield distribution over the area irradiated by the target's x‐rays in a polarized EDXRF spectrometer. A small solder disc, which was made of mainly lead and tin and with a diameter of about 3 mm, was scanned manually with equal displacements over the area. XRF spectra excited by radiation from three typical targets, namely, highly oriented pyrolytic graphite (HOPG), Mo and Al2O3, were collected. Intensities of Sn Kα and Lα and Pb Lα and Mα lines were obtained and used to describe the XRF yield distributions from different targets. The results showed that the total areas contributing to the XRF signal were over 2 cm2 for the above three targets. Also, Pb Mα and Sn Kα maps irradiated by HOPG and Al2O3, respectively, showed very high intensities in the central parts, while they were very low in the periphery. The sum of intensities from four spots in central area (corresponding to about 7 × 7 mm2) represents about 50% of overall integrated intensities of the 33 measured spots. Also, the sharpest areas of Pb Mα and Sn Kα were slightly shifted. Pb Lα maps obtained using the Mo target showed much larger distribution areas, with center being the most intense and becoming weaker gradually toward the outer parts. The relatively small irradiation areas of the polarized targets may require better sample homogeneity, and care should be taken when small pieces of samples are to be analyzed. Copyright © 2007 John Wiley & Sons, Ltd.

Moving finite-size dipole emission

Emission of a finite-size arbitrarily moving dipole is considered. It is shown that the dipole radiation intensity can be expressed in terms of the dipole moment of the system for wavelengths longer than the dipole size. In this case, the system radiation intensity is much lower than that of the unit charge. For wavelengths much shorter than the dipole size, the dipole radiation intensity is equal to the sum of radiation intensities of two charges. For wavelengths comparable to the dipole size, interference minima and maxima arise in the angular distribution of the radiation intensity.

The mapping of visual space by dragonfly lateral ocelli

We study the extent to which the lateral ocelli of dragonflies are able to resolve and map spatial information, following the recent finding that the median ocellus is adapted for spatial resolution around the horizon. Physiological optics are investigated by the hanging-drop technique and related to morphology as determined by sectioning and three-dimensional reconstruction. L-neuron morphology and physiology are investigated by intracellular electrophysiology, white noise analysis and iontophoretic dye injection. The lateral ocellar lens consists of a strongly curved outer surface, and two distinct inner surfaces that separate the retina into dorsal and ventral components. The focal plane lies within the dorsal retina but proximal to the ventral retina. Three identified L-neurons innervate the dorsal retina and extend the one-dimensional mapping arrangement of median ocellar L-neurons, with fields of view that are directed at the horizon. One further L-neuron innervates the ventral retina and is adapted for wide-field intensity summation. In both median and lateral ocelli, a distinct subclass of descending L-neuron carries multi-sensory information via graded and regenerative potentials. Dragonfly ocelli are adapted for high sensitivity as well as a modicum of resolution, especially in elevation, suggesting a role for attitude stabilisation by localization of the horizon.

Separation of surface and volume effects in scattering from heterogeneous rough surfaces: derivation of a splitting rule

We give theoretical support to the splitting rule, which was recently observed numerically for the scattering from heterogeneous rough surfaces. Under certain general conditions, the incoherent intensity of a composite medium with a rough interface is the sum of the incoherent intensity of the rough homogeneous surface with an effective permittivity and the incoherent intensity of the same composite medium below a flat interface. The coherent intensity is merely that of the rough effective homogeneous surface. The effective permittivity is given accurately by the Bruggemann mixing rule, provided that the scale of fluctuations in the volume is small with respect to the electromagnetic wavelength.

Discussion on Unique Characteristics of Second Order Harmonic in a Nonlinear Surface Acoustic Wave Investigated by Optical Diffraction Method

Unique capability of the second harmonic in a nonlinear surface acoustic wave (NLSAW) generated on 128° Y-X LiNbO3 substrate was investigated by optical diffraction technique. Amplitudes of the fundamental, the second harmonic, and the third harmonic in it were evaluated from an equation composed as a basis of the Beckmann-Spizzichino model. The experimental findings were as follows: the second harmonic velocity was faster than that of the fundamental; a full width at half maximum in envelope profile of the second harmonic was unchanged as if it experienced the gold thin film; total peak intensity in the envelope profile of the second harmonic during collision at gold thin film area was stronger than the sum of individual peak intensity of two second harmonics before the collision. From our experimental findings we conclude that the second harmonic has a soliton-like characteristic.

Gaussian-to-Lévy statistical crossover in a random amplifying medium: Monte Carlo simulation

We report Monte Carlo simulations of photons diffusing through a random amplifying medium and study the statistics of emitted intensity fluctuations. We observe a crossover from the Gaussian to the Lévy statistics corresponding to divergence of the variance of intensity fluctuations, as we go to large gain and strong scattering, consistent with our earlier analytical and experimental works. In the limit of very high gain, our simulations suggest a “Lévy microscope effect”, where the emitted mean intensity is expected to diverge, and the sum of intensities is dominated by the typical largest event.

Orientation-Independent Spectra for Biaxial Systems in Polarized Raman Microspectrometry

From an extension of the scattering intensity expressions in polarized Raman macrospectrometry to the case of micro-Raman backscattering experiments, we have established theoretical expressions to calculate orientation-independent intensity sums. This approach makes use of the K2 Raman invariant and of correction coefficients due to integration of the Raman scattering over the cone of collection of the objective lens, and it may be applied to uniaxial as well as to biaxial symmetry systems. The intensity sums thus obtained are expected to be orientation insensitive and allow one to compare conformational changes in various biaxially oriented polymer samples, either amorphous and/or semicrystalline thin films. As application examples we have compared the polarized Raman results obtained for various biaxially oriented amorphous and semicrystalline polystyrene (PS), poly(ethylene terenaphthalate) (PEN), and poly(ethylene terephthalate) (PET) thin film samples with their respective "isotropic spectrum" and have considered the different main conformational changes in related polymer systems. The method is thus tested on these macromolecular systems and appears quite successful in providing evidence for the molecular conformational changes without interferences from spectral contributions due to orientation.

Estimated long-term outdoor air pollution concentrations in a cohort study

Several recent studies associated long-term exposure to air pollution with increased mortality. An ongoing cohort study, the Netherlands Cohort Study on Diet and Cancer (NLCS), was used to study the association between long-term exposure to traffic-related air pollution and mortality. Following on a previous exposure assessment study in the NLCS, we improved the exposure assessment methods. Long-term exposure to nitrogen dioxide (NO 2), nitrogen oxide (NO), black smoke (BS), and sulphur dioxide (SO 2) was estimated. Exposure at each home address ( N=21 868) was considered as a function of a regional, an urban and a local component. The regional component was estimated using inverse distance weighed interpolation of measurement data from regional background sites in a national monitoring network. Regression models with urban concentrations as dependent variables, and number of inhabitants in different buffers and land use variables, derived with a Geographic Information System (GIS), as predictor variables were used to estimate the urban component. The local component was assessed using a GIS and a digital road network with linked traffic intensities. Traffic intensity on the nearest road and on the nearest major road, and the sum of traffic intensity in a buffer of 100 m around each home address were assessed. Further, a quantitative estimate of the local component was estimated. The regression models to estimate the urban component explained 67%, 46%, 49% and 35% of the variances of NO 2, NO, BS, and SO 2 concentrations, respectively. Overall regression models which incorporated the regional, urban and local component explained 84%, 44%, 59% and 56% of the variability in concentrations for NO 2, NO, BS and SO 2, respectively. We were able to develop an exposure assessment model using GIS methods and traffic intensities that explained a large part of the variations in outdoor air pollution concentrations.

What simple and complex cells compute

Visual neuroscientists seek to answer two related questions. First, what does the visual system do? Second, how does it do it? While an answer to the second question is a description based on anatomy and biophysics, an answer to the first question is a description of computations performed on images. Important steps in providing this description were made with the publication of two classical studies on primary visual cortex by Movshon et al. (1978a,b). These studies have not aged in their readability, and do not require an interpretive key to be enjoyed by the contemporary reader. As an introduction, however, this Perspectives article briefly reviews the state of the art at the time of their appearance, their main findings, and their influence on three decades of subsequent investigations.

Acute metabolic brain changes following traumatic brain injury and their relevance to clinical severity and outcome

Background: Conventional MRI can provide critical information for care of patients with traumatic brain injury (TBI), but MRI abnormalities rarely correlate to clinical severity and outcome. Previous magnetic resonance spectroscopy...

Dental Impaction Pain Model as a Potential Tool to Evaluate Drugs With Efficacy in Neuropathic Pain

Intravenous lidocaine, a nonspecific Na-channel blocker, was used to assess the dental impaction model for evaluation of neuropathic pain drugs. Sixty patients, experiencing moderate or severe pain after removal of > or = 2 third molars, were randomized (2:2:1:1) to lidocaine (4 mg/kg; maximal dose 300 mg), oxycodone/acetaminophen (10/650 mg), placebo, and active placebo (diphenhydramine, 50 mg). Lidocaine provided a modest degree of pain relief. Predefined endpoints of total pain relief and sum of pain intensity at 2, 4, and 6 hours showed numerically, not statistically significantly, greater pain relief versus placebo. A significantly greater effect over placebo was observed in peak effect and at shorter time points (30 minutes and 1 hour), consistent with the pharmacokinetic profile (plasma concentration of approximately 2 mug/mL). Oxycodone/acetaminophen provided significantly greater analgesia versus placebo, validating study conduct, and significantly greater pain relief was observed versus lidocaine, which is consistent with a smaller portion of dental extraction pain being of neuropathic origin.

Cooperative Hydration of Pyruvic Acid in Ice

About 3.5 +/- 0.3 water molecules are still involved in the exothermic hydration of 2-oxopropanoic acid (PA) into its monohydrate (2,2-dihydroxypropanoic acid, PAH) in ice at 230 K. This is borne out by thermodynamic analysis of the fact that QH(T) = [PAH]/[PA] becomes temperature independent below approximately 250 K (in chemically and thermally equilibrated frozen 0.1 < or = [PA]/M < or = 4.6 solutions in D2O), which requires that the enthalpy of PA hydration (DeltaHH approximately -22 kJ mol(-1)) be balanced by a multiple of the enthalpy of ice melting (DeltaHM = 6.3 kJ mol(-1)). Considering that: (1) thermograms of frozen PA solutions display a single endotherm, at the onset of ice melting, (2) the sum of the integral intensities of the 1deltaPAH and 1deltaPA methyl proton NMR resonances is nearly constant while, (3) line widths increase exponentially with decreasing temperature before diverging below approximately 230 K, we infer that PA in ice remains cooperatively hydrated within interstitial microfluids until they vitrify.

SIMS quantitative depth profiling of matrix elements in semiconductor layers

A new SIMS approach is proposed for quantified depth profiling of III–V semiconductor alloys. We show that the ratio of MCs + ion intensities to the sum of all element intensities (M 1Cs + + M 2Cs +…) from semiconductor alloys gives accurate elemental mole fraction when elements from the same periodic group are considered. Results obtained using SIMS show good agreement with data acquired using XPS and RBS.

Modeling spatial effects in multi-longitudinal-mode semiconductor lasers

The multi-longitudinal-mode dynamics of a semiconductor laser is studied theoretically, based on traveling-wave equations for the slowly varying amplitudes of the counterpropagating optical fields in the laser cavity, coupled to an equation for the carrier population dynamics. The model considers key ingredients describing the semiconductor medium, such as the spatial variations of the carriers and optical fields in the longitudinal direction, a parabolic frequency-dependent gain and phase-amplitude coupling, and does not assume a priori a fixed number of active longitudinal modes. We find deterministic out-of-phase modal oscillations which leave the sum of total modal intensities nearly constant. These oscillations become faster as the injection current increases, in good agreement with recent experimental observations. In our model the origin of modal oscillations is spatial hole burning in the envelope of the carrier grating, which is due to the interaction of different longitudinal modes. We also observe switching and hopping of the lasing modes in accordance with the experiments.

Identification of Novel Proteases and Immunomodulators in the Secretions of Schistosome Cercariae That Facilitate Host Entry

Schistosomiasis, caused by parasitic helminths, remains a serious human disease in the tropics. Cercariae of Schistosoma mansoni infect their hosts by direct skin penetration, aided by secretions from acetabular and head glands. Both proteolytic and immunomodulatory properties have been ascribed to the released material, but to date only five isoforms of elastase and one putative anti-inflammatory protein (Sm16) have been cloned. We analyzed secretions from mechanically transformed cercariae by two-dimensional electrophoresis. An average gel image was created and compared with a separation of soluble larval extract, revealing a less complex spot pattern in the secretions with 60% of the spots matched to the larval extract. Subsequent tandem mass spectrometric analysis identified 48 spots from the released material, representing approximately 80% of its normalized volume. Twenty-nine of these are likely to originate in the vesicles, and 18 are likely to originate in the cytosol of the glands (the latter class being present due to holocrine secretion); one is unknown. The vesicular proteins were significantly more enriched than the cytosolic proteins in the released material when compared with the larval extract. A novel metalloproteinase (termed SmPepM8) was the second most abundant constituent after three isoforms of cercarial elastase. In addition, a dipeptidyl peptidase IV (SmDPP IV) was discovered but in much smaller quantity. A new serine protease inhibitor (SmSerp_c) was also prominent. Along with Sm16, four potential immunomodulators were identified, three with similarity to venom allergens (SmSCP_a, _b, and _c) and one with homology to the potassium channel blockers in scorpion venom (SmKK7). Interrogation of the expressed sequence tag database found transcripts encoding the majority of vesicular proteins present solely in the intramolluscan stages of the life cycle. Distinct patterns of radiolabel incorporation suggested three separate origins for the vesicular proteins. All the novel constituents merit investigation as vaccine candidates, and the potential immunomodulators merit investigation as therapeutic agents.

Phase-shifting digital holography in image reconstruction

A phase-shifting digital holography scheme developed to investigate internal defects in artworks is described. Phase-shifting is utilized to obtain a clear reconstructed object wave from a rough surface texture. A reverse-transform algorithm is employed to reconstruct the object wave on its original position of unknown distance or the imaging position from the object wave information on the holographic plane. To get the clearest reconstruction the exact registration of the unknown distance is determined by applying the intensity sum as the auto-focusing function. The spatial resolution of the reconstruction image is also investigated for a variety of affecting factors. Laboratory results of reconstruction images under deformation are presented.