WorldWideScience

Sample records for characteristic signal intensity

  1. Intensity and directionality of bat echolocation signals

    DEFF Research Database (Denmark)

    Jakobsen, Lasse; Brinkløv, Signe; Surlykke, Annemarie

    2013-01-01

    , duration, intensity, and directionality of echolocation signals) in unison define the search volume probed by bats and in turn how bats perceive their surroundings. Small changes to individual parameters can, in combination, drastically change the bat's perception, facilitating successful navigation......The paper reviews current knowledge of intensity and directionality of bat echolocation signals. Recent studies have revealed that echolocating bats can be much louder than previously believed. Bats previously dubbed "whispering" can emit calls with source levels up to 110 dB SPL at 10 cm...... will increase signal directionality in the field along with intensity thus increasing sonar range. During the last phase of prey pursuit, vespertilionid bats broaden their echolocation beam considerably, probably to counter evasive maneuvers of eared prey. We highlight how multiple call parameters (frequency...

  2. Television signal transmission characteristics via BSE

    Science.gov (United States)

    Kozu, T.; Yamamoto, M.; Ohuchi, C.; Sugimoto, Y.; Fukuchi, H.

    1986-01-01

    The FM-TV signal transmission characteristics via BSE measured at the Main Transit and Receiving Station are described. Measurements are reported using 'standard parameters' which were carried out every half year from 1978 to 1980, measuring the video signal to noise ratio, waveform distortion, DG-DP, amplitude-frequency characteristics of video and audio signal, and the subjective assessment of video signal quality. These characteristics were good enough to broadcast a high-quality TV signal, and no degradation was observed for two years. Measurements using 'nonstandard parameters' were performed in order to study transmission parameters suitable for satellite broadcasting. Results are reported for one sound channel transmission using one FM subcarrier and for two sound channel transmission using two FM subcarriers.

  3. On the Signal-Image Intensity-Curvature Content

    Directory of Open Access Journals (Sweden)

    Carlo Ciulla

    2013-04-01

    Full Text Available The biomedical engineering problem addressed in this work is the one of finding a novel signal-image content measure called intensity-curvature functional making use of all of the second order derivatives of the model function fitted to the data. Given a signal-image made of a sequel of discrete samples and given a model function which embeds the property of second order differentiability, it is possible to quantify the content of the signal-image through a novel approach based on both of the intensity and of the total curvature of the signal-image. The signal-image is fitted with the model function. The total curvature can be calculated through the sum of all of the second order derivatives of the Hessian of the model function fitted to the data. The intensity-curvature functional is defined as the ratio between: (i the integral of the multiplication between the value of the signal modeled through an interpolation function and the total curvature of the signal-image; both of them at the temporal-spatial location of its sampling (the grid nodes and, (ii the integral of the value of the multiplication between the signal modeled through an interpolation function and the total curvature of the signal-image; both of them at any given temporal-spatial location of its re-sampling (intra-pixel location. This manuscript shows both of the formulae and the qualitative results of: the intensity-curvature functional and the intensity-curvature measures which are conceptually linked to the intensity-curvature functional. The formulations here presented make the engineering innovation. The intensity-curvature functional depends on both of the model function fitting the signal-image and the magnitude of re-sampling employed to calculate the second order derivatives of the Hessian of the model function.

  4. Evaluation of signal intensity of various thyroid tissues on MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Baba, Koichiro; Imanishi, Yoshimasa [St. Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine; Igarashi, Ryuukou; Shinagawa, Toshihito

    2001-08-01

    -binding proteins in normal thyroid follicles is the cause of low signal intensity on T2 weighted image despite of their abundant waster content. High signal intensity on T2 weighted image may be interpreted by decreased protein concentration of thyroid follicles based on decreased iodine concentration, as well. In addition, the findings of various thyroid diseases on STIR image were demonstrated to be almost the same to those on T2 weighted image. These characteristics of signal intensity on MR imaging might help in the understanding of thyroid pathophysiology and be useful for accurate diagnosis. (author)

  5. Exercise-induced endocannabinoid signaling is modulated by intensity.

    Science.gov (United States)

    Raichlen, David A; Foster, Adam D; Seillier, Alexandre; Giuffrida, Andrea; Gerdeman, Gregory L

    2013-04-01

    Endocannabinoids (eCB) are endogenous ligands for cannabinoid receptors that are densely expressed in brain networks responsible for reward. Recent work shows that exercise activates the eCB system in humans and other mammals, suggesting eCBs are partly responsible for the reported improvements in mood and affect following aerobic exercise in humans. However, exercise-induced psychological changes reported by runners are known to be dependent on exercise intensity, suggesting that any underlying molecular mechanism should also change with varying levels of exercise intensity. Here, we examine circulating levels of eCBs following aerobic exercise (treadmill running) in recreationally fit human runners at four different intensities. We show that eCB signaling is indeed intensity dependent, with significant changes in circulating eCBs observed following moderate intensities only (very high and very low intensity exercises do not significantly alter circulating eCB levels). Our results are consistent with intensity-dependent psychological state changes with exercise and therefore support the hypothesis that eCB activity is related to neurobiological effects of exercise. Thus, future studies examining the role of exercise-induced eCB signaling on neurobiology or physiology must take exercise intensity into account.

  6. Experiment course reform for researching campus wireless signal field intensity characteristics%校园内无线信号场强特性研究的实验课程改革

    Institute of Scientific and Technical Information of China (English)

    王琦; 韩玉芬; 杨鸿文

    2011-01-01

    校园内无线信号场强特性研究,是电磁场与微波实验室以培养创新型高素质人才为目标的一项实验课程改革.通过一系列实验环节的训练,使学生能够全面、深入地认识和理解在移动无线环境中电波传播规律、场强分布特点及场强的测量方法等,提高学生用“场”的观点和方法来分析问题、解决问题的能力,培养学生的创新能力和实践能力.该文从实验的具体内容和步骤、改革的效果、特点等方面进行了论述.%Researching the campus wireless field intensity strength characteristics is an experiment course based on the Electromagnetic Field and Microwave Laboratory reforms in order to develop innovative talents. After a series of experimental procedures, the students have deep and comprehensive understanding and awareness of the radio wave propagation laws, the field intensity distribution function and measurement methods for wireless communication channels, etc. The abilities of the students are improved with the "field" point of view and methods to analyze and solve the problems. Innovation and practical abilities of the students are cultivated. The detailed experimental content and procedures, the effect and feature of the reformation are all discussed.

  7. 基于WiFi信号强度特征的室内定位系统设计%Design of Indoor Positioning System Based on WiFi Signal Intensity Characteristic

    Institute of Scientific and Technical Information of China (English)

    徐潇潇; 谢林柏; 彭力

    2015-01-01

    针对室内GPS定位无法准确获取位置信息的问题,在Android平台上设计利用WiFi信号强度特征进行定位的系统。该系统由安卓客户端、Tomcat服务器以及MySQL数据库组成,在一般位置指纹定位算法的基础上,通过MAC地址对无线接入点( AP)进行过滤,选取固定的参考AP获取位置指纹信息,并结合改进的K最近邻匹配算法,进一步减小定位误差。实验结果表明,该系统定位速度快、定位精度高,具有较好的室内定位效果。%Aiming at the problem that it is unable to get a more accurate location information indoors by using GPS positioning,this paper designs a positioning system using characteristics of WiFi signal strength based on Android platform,meets the demands of location information of indoor environment for people. The system consists of Android client,Tomcat server and MySQL database. Based on the general location fingerprint algorithm,this system adds MAC addresses to Access Point( AP) filtering,and gets the location fingerprint information by selecting fixed reference AP. On positioning stage,the weighting factor is added on the basis of the K-Nearest Neighbor( KNN) algorithm to further reduce the positioning error. Experimental results show that the system has the advantages of high precision and fast positioning, and it can achieve a good effect of indoor positioning.

  8. Decreased vestibular signal intensity on 3D-FIESTA in vestibular schwannomas differentiating from meningiomas.

    Science.gov (United States)

    Ishikawa, Kazuhiro; Haneda, Jun; Okamoto, Kouichirou

    2013-02-01

    With reported characteristic MR features, it is difficult to differentiate vestibular schwannomas (VSs) from cerebellopontine angle (CPA) meningiomas (CPAMs) in some cases. This study aimed to evaluate vestibular signal intensity changes in patients with VS and those with CPAM on three-dimensional fast imaging employing steady-state acquisition (3D-FIESTA), and to test the effectiveness of the signal intensity change to differentiate these two common CPA tumors. We retrospectively reviewed 21 patients with unilateral VS, six patients with unilateral CPAM, and 25 control subjects. Setting regions of interest in the bilateral vestibules and cerebellar white matter on 3D-FIESTA, we compared the ratio of the signal intensity (SIR) of the vestibule to that of the cerebellar white matter (SIRv) among the VS, CPAM, and control subject groups. We also compared the ratio of SIRv on the affected side (a-SIRv) to that on the unaffected side (AURv) between the VS and CPAM. The a-SIRv in the VS group was significantly lower than the overall SIRv in the control subjects (pre-contrast, P FIESTA was observed in patients with VS, but not in those with CPAM or in normal subjects. The signal intensity change has the potential to be used in differentiating VS from CPAM.

  9. Quantitative Analysis of Diffusion Weighted MR Images of Brain Tumor Using Signal Intensity Gradient Technique

    Directory of Open Access Journals (Sweden)

    S. S. Shanbhag

    2014-01-01

    Full Text Available The purpose of this study was to evaluate the role of diffusion weighted-magnetic resonance imaging (DW-MRI in the examination and classification of brain tumors, namely, glioma and meningioma. Our hypothesis was that as signal intensity variations on diffusion weighted (DW images depend on histology and cellularity of the tumor, analysing the signal intensity characteristics on DW images may allow differentiating between the tumor types. Towards this end the signal intensity variations on DW images of the entire tumor volume data of 20 subjects with glioma and 12 subjects with meningioma were investigated and quantified using signal intensity gradient (SIG parameter. The relative increase in the SIG values (RSIG for the subjects with glioma and meningioma was in the range of 10.08–28.36 times and 5.60–9.86 times, respectively, compared to their corresponding SIG values on the contralateral hemisphere. The RSIG values were significantly different between the subjects with glioma and meningioma (P<0.01, with no overlap between RSIG values across the two tumors. The results indicate that the quantitative changes in the RSIG values could be applied in the differential diagnosis of glioma and meningioma, and their adoption in clinical diagnosis and treatment could be helpful and informative.

  10. Prediction of UV and ESI-MS signal intensities.

    Science.gov (United States)

    Mauser, Harald; Roche, Olivier; Stahl, Martin; Müller, Stephan

    2005-01-01

    All major pharmaceutical companies maintain large collections of compounds that are used either for screening against biological targets or as synthetic precursors. The quality assessment of these compounds is typically done by liquid chromatography combined with mass spectroscopy (LC/MS) and UV purity control. To facilitate the analysis of the analytical data, we have built computational models to predict UV and MS signal intensities under experimental LC/MS conditions. The discriminant partial-least-squares technique was used for classifying compounds into those most likely to yield a MS signal and others where the signal is below the detection limit (94% and 88% correct predictions, respectively). In the case of UV prediction, we compared this statistical linear-regression technique to a knowledge-based approach. A combination of both techniques proved to be the most reliable (96/98% correct predictions of UV-active/ UV-inactive compounds). Both models have been incorporated into the automated compound integrity profiling at F. Hoffmann-La Roche.

  11. Different research designs and their characteristics in intensive care

    Science.gov (United States)

    Nedel, Wagner Luis; da Silveira, Fernando

    2016-01-01

    Different research designs have various advantages and limitations inherent to their main characteristics. Knowledge of the proper use of each design is of great importance to understanding the applicability of research findings to clinical epidemiology. In intensive care, a hierarchical classification of designs can often be misleading if the characteristics of the design in this context are not understood. One must therefore be alert to common problems in randomized clinical trials and systematic reviews/meta-analyses that address clinical issues related to the care of the critically ill patient. PMID:27737421

  12. Amplification and Damping of Environmental Signals in Intensively Managed Landscapes

    Science.gov (United States)

    Belmont, P.; Kumarasamy, K.; Kelly, S. A.; Vaughan, A. A.; Call, B.

    2015-12-01

    Landscapes transmit pulses of water, sediment and solutes through the terrestrial environment and network of stream channels. The timing, frequency and magnitude of these pulses depend on inputs of water, energy and rock/soil as well as a multitude of critical zone processes that may modulate the signal. Therefore, the potential for a landscape to generate and transmit these pulses changes over long timescales, primarily as a function of climate and local base level rise or fall. Humans have profoundly altered many critical zone processes that govern these environmental signals, often targeting rate-limiting processes for the purpose of enhancing economic productivity and/or reducing financial risk. These alterations are especially evident in the intensively managed landscapes of the Midwestern US, where vegetation change, soil tillage, and pervasive modifications of the surface and subsurface drainage system have substantially changed water, sediment and nutrient fluxes. Effects, in terms of amplification or damping of environmental signals, are strongly dependent on landscape setting, and often non-linear. Hysteresis and sensitivity may hinder the return to the initial state when perturbations have reached a certain threshold. We draw from multiple examples in the upper Midwestern US to illustrate, at a basic level, the mechanisms by which landscape evolution establishes the template for generation and transmission of environmental signals and furthermore how humans have altered critical zone processes to optimize specific landscape outputs, often at the expense of modifying the rate and/or magnitude of many other landscape outputs. We present a conceptual model and discuss implications for mathematical modeling of water, sediment and nutrient fluxes to guide watershed management and restoration.

  13. Variability of morphology and signal intensity of alar ligaments in healthy volunteers using MR imaging.

    Science.gov (United States)

    Lummel, N; Zeif, C; Kloetzer, A; Linn, J; Brückmann, H; Bitterling, H

    2011-01-01

    Evaluation of alar traumatic injuries by using MR imaging is frequently performed. This study investigates the variability of morphology and signal intensity of alar ligaments in healthy volunteers so that pathology can be more accurately defined. Fifty healthy volunteers were examined on a 1.5T MR imaging scanner with 2-mm PD-weighted sequences in 3 planes. Delineation of the alar ligaments in 3 planes and signal-intensity characteristics on sagittal planes were analyzed by using a 4-point grading scale. Variability of courses and morphologic characteristics were described. Delineation of alar ligaments was best viewed in the coronal plane, followed by the sagittal and axial planes. In the sagittal view, 6.5% of alar ligaments appeared homogeneously dark. Hyperintense signal intensity in up to one-third of the cross-sectional area was present in 33% of cases; in up to two-thirds of the cross-sectional area, in 45% of cases; and in more than two-thirds of the cross-sectional area, in 15% of cases. Of alar ligaments, 58.5% ascended laterally, 40.5% ran horizontally, and 1% descended laterally. The cross-sectional area was round in 41.5%, oval in 51.5%, and winglike in 6.5%. On 1.5T MR imaging, the alar ligaments can be delineated best in the coronal and sagittal planes. Our data indicate a remarkable variability of morphology and course as well as signal intensity. This finding is contradictory to former publications assigning such alterations exclusively to patients with trauma.

  14. Signal intensity analysis of ecological defined habitat in soft tissue sarcomas to predict metastasis development

    Science.gov (United States)

    Farhidzadeh, Hamidreza; Chaudhury, Baishali; Scott, Jacob G.; Goldgof, Dmitry B.; Hall, Lawrence O.; Gatenby, Robert A.; Gillies, Robert J.; Raghavan, Meera

    2016-03-01

    Magnetic Resonance Imaging (MRI) is the standard of care in the clinic for diagnosis and follow up of Soft Tissue Sarcomas (STS) which presents an opportunity to explore the heterogeneity inherent in these rare tumors. Tumor heterogeneity is a challenging problem to quantify and has been shown to exist at many scales, from genomic to radiomic, existing both within an individual tumor, between tumors from the same primary in the same patient and across different patients. In this paper, we propose a method which focuses on spatially distinct sub-regions or habitats in the diagnostic MRI of patients with STS by using pixel signal intensity. Habitat characteristics likely represent areas of differing underlying biology within the tumor, and delineation of these differences could provide clinically relevant information to aid in selecting a therapeutic regimen (chemotherapy or radiation). To quantify tumor heterogeneity, first we assay intra-tumoral segmentations based on signal intensity and then build a spatial mapping scheme from various MRI modalities. Finally, we predict clinical outcomes, using in this paper the appearance of distant metastasis - the most clinically meaningful endpoint. After tumor segmentation into high and low signal intensities, a set of quantitative imaging features based on signal intensity is proposed to represent variation in habitat characteristics. This set of features is utilized to predict metastasis in a cohort of STS patients. We show that this framework, using only pre-therapy MRI, predicts the development of metastasis in STS patients with 72.41% accuracy, providing a starting point for a number of clinical hypotheses.

  15. Effect of the luminol signal enhancer on the chemiluminescence intensity and kinetics

    Energy Technology Data Exchange (ETDEWEB)

    Liang Yanli [College of Public Health, Zhengzhou University, Zhengzhou 450001 (China); Department of Chemistry, Zhengzhou University, Zhengzhou 450001 (China); Yu Fei; Yu Songcheng [College of Public Health, Zhengzhou University, Zhengzhou 450001 (China); Wu Yongjun, E-mail: wuyongjun@zzu.edu.cn [College of Public Health, Zhengzhou University, Zhengzhou 450001 (China); Department of Chemistry, Zhengzhou University, Zhengzhou 450001 (China); Zhang Hongquan [College of Public Health, Zhengzhou University, Zhengzhou 450001 (China); Qu Lingbo [Department of Chemistry, Zhengzhou University, Zhengzhou 450001 (China)

    2012-04-15

    The novel p-phenol derivatives, 4-(1-imidazolyl)-phenol, 4-hydroxybiphenyl, 4-hydroxy-4 Prime -iodobiphenyl were employed as highly potent signal enhancers of luminol-hydrogen peroxide (H{sub 2}O{sub 2})-horseradish peroxidase (HRP) chemiluminescence (CL) system. The CL reaction conditions were optimized, and the enhancement characteristics of these enhancers were compared with each other. The employment of these molecules greatly affected important assay parameters. Practically, the use of a novel enhancer, even a slightly change of the structure (or concentration) of 4-substituted phenol derivative, could affect assay properties quite dramatically. Furthermore, the use of different enhancers in the luminol-H{sub 2}O{sub 2}-HRP system can affect not only the intensity of the CL signal, which is well known, but also its kinetics. The experiment data indicated that the stronger intensity was combined with a more rapid decrease of the CL signal. - Highlights: Black-Right-Pointing-Pointer 4-IMP, 4-BIP and HIOP take on different signal enhancement and light kinetics. Black-Right-Pointing-Pointer The employment of 4-BIP resulted in a significant improvement of the detection limit. Black-Right-Pointing-Pointer The magnitude of the signal enhancement was about 2.5-fold in the same system.

  16. MR imaging of renal cell carcinoma: associations among signal intensity, tumor enhancement, and pathologic findings.

    Directory of Open Access Journals (Sweden)

    Yabuki T

    2003-08-01

    Full Text Available The purpose of this study was to compare the MR characteristics of renal cell carcinomas against histologic findings and to assess the correlations among signal intensity, tumor enhancement, and pathologic findings. Fifty-four patients (56 lesions were examined by MR imaging and then underwent partial or radical nephrectomy. The pathologic diagnosis of all lesions was renal cell carcinoma. All MR examinations were performed as dynamic studies using the same 1.5-T scanner. MR characteristics were compared against pathologic findings after resection, and the correlations among signal intensity, tumor enhancement, and pathologic findings were then assessed. A significant correlation was observed between tumor grade and tumor enhancement, with G3 lesions tending to show little enhancement. Regardless of the histologic classification, G3 tumors were found to contain highly heterotypic cancer cells and very few vessels by histopathologic examination. No significant correlations were noted between the other MR characteristics and pathologic findings. Renal cell carcinomas showing little enhancement tend to be highly malignant lesions based on the pathologic findings. Special consideration is required for these tumors with regard to the selection of surgical intervention and follow-up observation.

  17. Propagation and effects of monsoonal seasonally intense rainfall signal in river strata

    Science.gov (United States)

    Plink-Bjorklund, P.

    2014-12-01

    Climatic forcing signals in river systems tend to be modified on different temporal and spatial scales due to inherent signal buffering, re-routing, and a complex mixing of multiple autogenic and allogenic signals. Thus climate forcing response is generally assumed inherently non-linear with significant hysteresis effects. This paper explores propagation and effects of monsoonal, seasonally intense rainfall signal in river strata in the monsoonal and bordering subtropical domains. Some such rivers occur completely within the monsoon climate zone. Others have parts of their drainages in temperate climate zones, or on high elevations and receive some of their water discharge from other sources. Yet others, have their upstream drainages in the tropical monsoon climates, but flow through bordering subtropical drylands. Yet, all these rivers characteristically experience seasonal high magnitude floods as the effect of intense monsoon precipitation. Many rivers in the bordering subtropical zone receive monsoon rain and transmit discharge only during abnormal or strengthened monsoon seasons and associated cyclonic flow. Field datasets, comparison to modern river deposits and a literature review of monsoonal and bordering subtropical domain rivers reveal that the effects of the intense seasonal monsoon rain and the resultant flooding are readily recognizable in modern and ancient fluvial strata. This paper argues that this distinct and dominant climate signal propagation occurs because it is the monsoon discharge that is commonly responsible for up to 100% of sediment erosion, transport and deposition, creating a system wide flushing or splash effect on a single season to multi-million year time scale. The distinct monsoon flood deposits are interbedded with other types of fluvial strata in systems where significant deposition also occurs from low-magnitude flood or non-flood discharges.

  18. Pump-to-Signal Intensity Modulation Transfer in Saturated- Gain Fiber Optical Parametric Amplifiers

    DEFF Research Database (Denmark)

    Lali-Dastjerdi, Zohreh; Lund-Hansen, Toke; Rottwitt, Karsten

    2011-01-01

    The pump-to-signal intensity modulation transfer in saturated degenerate FOPAs is numerically investigated over the whole gain bandwidth. The intensity modulation transfer decreases and the OSNR improves when the amplifier operates in the saturation regime....

  19. Analysis of small-signal intensity modulation of semiconductor lasers taking account of gain suppression

    Indian Academy of Sciences (India)

    Moustafa Ahmed; Ali El-Lafi

    2008-07-01

    This paper demonstrates theoretical characterization of intensity modulation of semiconductor lasers (SL’s). The study is based on a small-signal model to solve the laser rate equations taking into account suppression of optical gain. Analytical forms of the small-signal modulation response and modulation bandwidth are derived. Influences of the bias current, modulation index and modulation frequency as well as gain suppression on modulation characteristics are examined. Computer simulation of the model is applied to 1.55-m InGaAsP lasers. The results show that when the SL is biased far-above threshold, the increase of gain suppression increases both the modulation response and its peak frequency. The modulation bandwidth also increases but the laser damping rate decreases. Quantitative description of the relationships of both modulation bandwidth vs. relaxation frequency and maximum modulation bandwidth vs. nonlinear gain coefficient are presented.

  20. Assessment of MR signal intensity of cranium and cervical spine bone marrow

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Min; Joh, Young Duk; Huh, Jin Do; Kim, So Sun [Kosin Medical College, Pusan (Korea, Republic of)

    1993-11-15

    The components of bore marrow change dramatically during lifetime. To evaluate the bone marrow of cranium and upper cervical spine, the authors retrospectively evaluated 300 examinations of cranium and the second cervical bone in patients without known bone marrow abnormality. T1-weighted images were used to analyze the changes of lone marrow signal intensity according to the age and sex. The signal intensity of bone marrow of cranium increased most rapidly from birth to age of 10 years. Between 11 and 20 years of age, gradual increase of signal intensity was noted. There was minimal augment of signal intensity after age of 20 tears. The examination of signal intensity of bone marrow of the cranium revealed slightly higher score in male than in female. The synchondrosis of the second cervical vertebra was visible in 97%. These results may be useful in the detection of abnormal bone marrow signal of cranium and upper cervical spine.

  1. Lumbar facet joint synovial cysts: does T2 signal intensity predict outcomes after percutaneous rupture?

    Science.gov (United States)

    Cambron, S C; McIntyre, J J; Guerin, S J; Li, Z; Pastel, D A

    2013-08-01

    Lumbar facet synovial cysts are a cause of back pain and radiculopathy with facet joint degeneration, the most common cause for cyst formation. Typically, LFSCs are T2 hyperintense on MR imaging, but the signal intensity is variable. Treatment options include percutaneous rupture and surgical resection. This study evaluates the relationship between LFSC signal intensity on MR imaging and outcomes as it relates to percutaneous rupture success and need for subsequent surgery. A retrospective review of 110 patients who underwent CT fluoroscopic-guided rupture of symptomatic LFSCs was performed. The LFSCs were characterized by their T2 signal intensity on MR imaging and divided into 3 groups: high, intermediate, and low T2 signal intensity. The rates of successful cyst rupture and need for subsequent surgery were recorded. Percutaneous LFSC rupture was technically successful in 87% of all cases. Cyst rupture was successful in 89% and 90% of high and intermediate signal intensity cysts, respectively, and in 65% of low signal intensity cysts (P = .017, .030). High signal intensity cysts had lower postprocedural surgical rates (29%) when compared with intermediate and low signal cyst as a group (P = .045). T2 hyperintense and intermediate signal intensity LFSCs are easier to rupture, perhaps because the cysts contain a higher proportion of fluid and are less gelatinous or calcified than T2 hypointense cysts. Patients with T2 hyperintense LFSCs are less likely to need surgery.

  2. Evaluation of lumbar disc lesions in teen-agers using magnetic resonance imaging; A correlative study between peridiscal signal intensity and nuclear signal intensity in 500 discs

    Energy Technology Data Exchange (ETDEWEB)

    Urakado, Misao; Naruo, Masakuni; Koyanagi, Eiichi; Taoka, Yuuji; Shiiba, Mutuo; Ryouki, Yoshihiro; Kitazono, Tooru; Kato, Yoshiyuki (Naruo Orthopedic Hospital, Kumamoto (Japan))

    1993-09-01

    The peridiscal and nuclear (nucleus pulposus and inner layer of annulus fibrosus) signal intensities in 500 discs of teen-age patients were compared with common degenerative lumbar disc disease. Images were taken with a 7 mm slice thickness and T[sub 2] weighted (TE 80[approx]90 mS, TR 2000[approx]2200 mS) midsagittal imaging. Clear correlation between these intensities was found. The signal intensity primarily decreased in the peridiscal tissues and secondarily decreased in the nucleus pulposus and inner layer of annulus fibrosus. These findings suggest that peridiscal disorders cause degenerative changes of the nucleus pulposus. Additionally, in the early degenerative stage of the teen-age lumbar disc, a decrease of nuclear signal intensity indicated that degenerative changes originated from the anterior portion and extended posteriorly. (author).

  3. [Reflected high-intensity motion signals as markers of left ventricular diastolic dysfunction].

    Science.gov (United States)

    Makarenko, E S

    2013-01-01

    Reflected high-intensity signals of left ventricular motion can be used for assessment of diastolic function of left ventricle. There are many correlations between reflected high-intensity signals, transmitral flow, and tissue Doppler imaging parameters. Diagnostic criteria of LV diastolic dysfunction based on measurement of LV motion are suggested.

  4. MR ASSESSMENT OF LUNG DEVELOPMENT IN FETAL ANOMALIES USING RATIO OF LUNG TO LIVER SIGNAL INTENSITIES

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Objective To evaluate the monitoring and diagnostic potential of MR in fetal lung development using lung signal intensity changes in the fetus. Methods The lung-to-liver intensity ratio was calculated by means of region-of-interest analysis in all 35 fetuses including 7 bilateral urinary anomalies, 9 unilateral urinary anomalies, 5 pulmonary anomalies, and 14 others. Results All fetuses with urinary anomalies and pulmonary anomalies showed low ratio of lung-to-liver signal intensity. Conclusion Low ratio of lung-to-liver signal intensity on MR imaging indicates pulmonary hypoplasia after 22 weeks' gestation.

  5. Magnetic resonance angiography signal intensity as a marker of hemodynamic impairment in intracranial arterial stenosis.

    Directory of Open Access Journals (Sweden)

    Xinyi Leng

    Full Text Available BACKGROUND: Intracranial arterial stenosis (ICAS is the predominant cause of ischemic stroke and transient ischemic attack in Asia. Change of signal intensities (SI across an ICAS on magnetic resonance angiography (MRA may reflect its hemodynamic severity. METHODS: In-patients with a symptomatic single ICAS detected on 3D time-of-flight MRA were recruited from 2 hospitals. Baseline and 1-year follow-up data were collected. Signal intensity ratio (SIR [ =  (mean post-stenotic SI -mean background SI/(mean pre-stenotic SI - mean background SI] was evaluated on baseline MRA to represent change of SIs across an ICAS. Acute infarct volume was measured on baseline diffusion-weighted images (DWI. Relationships between SIR and baseline characteristics as well as 1y outcomes were evaluated. RESULTS: Thirty-six subjects (86.1% males, mean age 55.0 were recruited. Overall, mean SIR was 0.84±0.23. Mean SIRs were not significantly different between the 23 (63.9% anatomically severe stenoses and the 13 (36.1% anatomically moderate stenoses (0.80±0.23 versus 0.92±0.21, p = 0.126. SIR was significantly, linearly and negatively correlated to acute infarct volume on DWI (Spearman correlation coefficient -0.471, p = 0.011. Two patients (5.6% had recurrent ischemic strokes at 1y, not related to SIR values. CONCLUSIONS: Change of signal intensities across an ICAS on MRA may reflect its hemodynamic and functional severity. Future studies are warranted to further verify the relationships between this index and prognosis of patients with symptomatic ICAS.

  6. Patient characteristics associated with false arrhythmia alarms in intensive care.

    Science.gov (United States)

    Harris, Patricia R; Zègre-Hemsey, Jessica K; Schindler, Daniel; Bai, Yong; Pelter, Michele M; Hu, Xiao

    2017-01-01

    A high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics. A total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients' annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient characteristics were compared in relation to 1) the

  7. Patient characteristics associated with false arrhythmia alarms in intensive care

    Science.gov (United States)

    Harris, Patricia R; Zègre-Hemsey, Jessica K; Schindler, Daniel; Bai, Yong; Pelter, Michele M; Hu, Xiao

    2017-01-01

    Introduction A high rate of false arrhythmia alarms in the intensive care unit (ICU) leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds) at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and ventricular bradycardia) as true or false. Total monitoring time for each patient was measured, and the number of false alarms per hour was calculated for these six alarm types. Medical records were examined to acquire data on patient characteristics. Results A total of 461 unique patients (mean age =60±17 years) were enrolled, generating a total of 2,558,760 alarms, including all levels of arrhythmia, parameter, and technical alarms. There were 48,404 hours of patient monitoring time, and an average overall alarm rate of 52 alarms/hour. Investigators annotated 12,671 arrhythmia alarms; 11,345 (89.5%) were determined to be false. Two hundred and fifty patients (54%) generated at least one of the six annotated alarm types. Two patients generated 6,940 arrhythmia alarms (55%). The number of false alarms per monitored hour for patients’ annotated arrhythmia alarms ranged from 0.0 to 7.7, and the duration of these false alarms per hour ranged from 0.0 to 158.8 seconds. Patient

  8. Pedicle marrow signal intensity changes in the lumbar spine: a manifestation of facet degenerative joint disease

    Energy Technology Data Exchange (ETDEWEB)

    Morrison, J.L.; Kaplan, P.A.; Dussault, R.G.; Anderson, M.W. [Dept. of Radiology, Univ. of Virginia Health System, Charlottesville, VA (United States)

    2000-12-01

    Objective. Signal intensity changes in lumbar pedicles, similar to those described in vertebral body endplates adjacent to degenerated discs, have been described as an ancillary sign of spondylolysis on MRI. The purpose of this study was to determine whether pedicle marrow signal intensity changes also occur in association with facet degenerative joint disease.Design. Eighty-nine lumbar spine MRI examinations without spondylolysis were reviewed for marrow signal intensity changes in pedicles and vertebral bodies as well as for facet degenerative joint disease.Results. Five percent (46/890) of lumbar pedicles in 23 patients had marrow signal intensity changes. Ninety-one percent (42/46) of the abnormal pedicles had adjacent degenerative joint disease of the facets, while only 21% (189/890) of normal pedicles had adjacent facet degenerative joint disease (p<0.001). Eighty-nine percent (41/46) of the pedicles with marrow signal intensity changes had adjacent degenerative disc disease.Conclusions. Pedicle marrow signal intensity changes are not a specific sign of spondylolysis; they are commonly seen with adjacent facet degenerative joint disease in the absence of spondylolysis. Pedicle marrow signal intensity changes are probably a response to abnormal stresses related to abnormal motion or loading caused by the degenerative changes in the spinal segment. (orig.)

  9. Patient characteristics associated with false arrhythmia alarms in intensive care

    Directory of Open Access Journals (Sweden)

    Harris PR

    2017-04-01

    Full Text Available Patricia R Harris,1,2 Jessica K Zègre-Hemsey,3,4 Daniel Schindler,5 Yong Bai,6 Michele M Pelter,2,7 Xiao Hu2,8 1Department of Nursing, School of Health and Natural Sciences, Dominican University of California, San Rafael, 2Department of Physiological Nursing, School of Nursing, University of California, San Francisco, CA, 3School of Nursing, 4Department of Emergency Medicine, School of Medicine, University of North Carolina at Chapel Hill, NC, 5Intensive Care Unit, The Neuroscience Center, Sutter Eden Medical Center, Castro Valley, 6Hu Research Laboratory, Department of Physiological Nursing, School of Nursing, University of California, San Francisco, 7ECG Monitoring Research Lab, Department of Physiological Nursing, School of Nursing, 8Physiological Nursing and Neurological Surgery, Affiliate Faculty of Institute for Computational Health Sciences Core Faculty UCB/UCSF Joint Bio-Engineering Graduate Program, University of California, San Francisco, CA, USA Introduction: A high rate of false arrhythmia alarms in the intensive care unit (ICU leads to alarm fatigue, the condition of desensitization and potentially inappropriate silencing of alarms due to frequent invalid and nonactionable alarms, often referred to as false alarms. Objective: The aim of this study was to identify patient characteristics, such as gender, age, body mass index, and diagnosis associated with frequent false arrhythmia alarms in the ICU. Methods: This descriptive, observational study prospectively enrolled patients who were consecutively admitted to one of five adult ICUs (77 beds at an urban medical center over a period of 31 days in 2013. All monitor alarms and continuous waveforms were stored on a secure server. Nurse scientists with expertise in cardiac monitoring used a standardized protocol to annotate six clinically important types of arrhythmia alarms (asystole, pause, ventricular fibrillation, ventricular tachycardia, accelerated ventricular rhythm, and

  10. effect of light intensity on the cure characteristics of photo ...

    African Journals Online (AJOL)

    2012-05-05

    May 5, 2012 ... Design: A laboratory based cross sectional study. Setting: Public and ... set out to determine the light intensity emitted by light curing units ... polymerised with it. MATERIAL AND METHODS ..... J. of Oral Rehab. 2005; 32:.

  11. Direct UV written Michelson interferometer for RZ signal generation using phase-to-intensity modulation conversion

    DEFF Research Database (Denmark)

    Peucheret, Christophe; Geng, Yan; Zsigri, Beata

    2005-01-01

    An integrated Michelson delay interferometer structure making use of waveguide gratings as reflective elements is proposed and fabricated by direct ultraviolet writing. Successful return-to-zero alternate-mark-inversion signal generation using phase-to-intensity modulation conversion...

  12. Signal-intensity-ratio MRI accurately estimates hepatic iron load in hemodialysis patients

    Directory of Open Access Journals (Sweden)

    Guy Rostoker

    2017-01-01

    Conclusions: This pilot study shows that liver iron determination based on signal-intensity-ratio MRI (Rennes University algorithm very accurately identifies iron load in hemodialysis patients, by comparison with liver histology.

  13. Easy ways to remember the progression of MRI signal intensity changes of intracranial hemorrhage

    Energy Technology Data Exchange (ETDEWEB)

    Maizlin, Z.V. [Dept. of Radiology, McMaster Univ. Medical Centre, Hamilton, Ontario (Canada)], E-mail: zeev25@yahoo.com; Shewchuk, J.R. [Medical Imaging, Royal Columbian Hospital, New Westminster, British Columbia (Canada); Clement, J.J. [Radiology, St Paul' s Hospital, Vancouver, British Columbia (Canada)

    2009-04-15

    This paper discusses the different ways to remember the progression of MRI signal intensity changes of intracranial hemorrhage. Several techniques that have been proposed to remember the progression of MRI signal intensity changes occurring in hematomas with time are discussed. In the opinion of the authors, the graph method is the easiest to remember. This may be because radiology is a highly visual speciality, and visual mnemonics seem easier to remember.

  14. ROI measurement of the signal intensity of precentral cortex in the normal brain

    Energy Technology Data Exchange (ETDEWEB)

    Karaarslan, Ercan E-mail: arzuarslan@netscape.net; Arslan, Arzu

    2004-12-01

    Objective: It has recently been described that perirolandic cortex generally had a low signal intensity (SI) in neurologically normal brain. The aim of this study was to confirm this finding by an objective quantitative study. Materials and methods: Turbo fluid attenuated inversion recovery (FLAIR) magnetic resonance (MR) images of 24 neurologically normal patients were evaluated retrospectively. Signal intensity measurements of the precentral and superior frontal cortices (SFCs) were obtained at a manually traced irregular region-of-interest (ROI). t-Test for paired samples was used to evaluate the significance of differences between signal intensity measurements. Results: Mean signal intensities of precentral and superior frontal cortices were 349.5 and 380.7, respectively, on the right, and 351.7 and 374.1 on the left hemisphere. The difference between the mean signal intensities of the side-matched precentral and superior frontal cortices was statistically significant (P<0.001). Conclusion: Low signal intensity of the precentral cortex (PCC) in normal brain on turbo FLAIR images is an objective finding, confirmed by ROI measurement.

  15. MR imaging of lumbar spondylolysis: signal intensity change in the pars interarticularis and adjacent structures

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Suk Whan; Lee, Ghi Jai; Shim, Jae Chan; Kim, Ho Kyun [Inje Univ. College of Medicine, Kimhae (Korea, Republic of)

    2001-05-01

    To assess changes in MR signal intensity in the pars interarticularis and adjacent structures in patients with lumbar spondylolysis. The MR images of 36 patients with lumbar spondylolysis, confirmed by plain radiographs, were retrospectively analyzed. Using a 1.0T unit, we evaluated the signal intensity of a total of 216 parts interarticulares and adjacent structures from L3 to L5, as seen on sagittal images, and differences between areas with and without spondylolysis. The signal intensity of T1-and T2-weighted images was graded 0(more hypointense than spinal body), 1(as isointense as spinal body), 2(more hyperintense than spinal body and more hypointense than epidural fat), or 3(as isointense as epidural fat). Signal intensity change in endplates and degree of spondylolisthesis were analyzed, and the relationship between these factors was determined. Spondylolysis was noted at L5 in 61 cases, at L4 in 22, and of L3 in no case. In three cases spondylolysis was unilateral, and in the remainder it was bilateral. The degree of signal intensity was the same on T1-and T2-weighted images, and no case was grade 0. Eighty-six of 133 areas without spondylolysis were grade 1, 43 were grade 2, and four were grade 3. In 42 of 47 cases, signal intensity change was localized at pedicles. Among 83 areas with spondylolysis,on the other hand, nine were grade 1, 48 were grade 2, and 26 were grade 3. Signal intensity change was most commonly observed at the pars interarticularis, pedicle, and lamina(50/74)({rho}<0.001). Signal intensity change at the pars interarticularis and adjacent structures was accompanied in most cases by degenerative endplate change(10/11) and spondylolisthesis(11/13)({rho}<0.001). In patients with spondylolysis, signal intensity was frequently higher at the pars interarticularis and adjacent structures, and is thought to have a close relationship with degenerative endplate change and spondylolisthesis. Increases in signal intensity at the pars

  16. Intensity of smiling and attractiveness as facial signals of trustworthiness in women.

    Science.gov (United States)

    Schmidt, K; Levenstein, R; Ambadar, Z

    2012-06-01

    Facial attractiveness is associated with a variety of positive social characteristics including trustworthiness. Variations in smiling, such as the appearance of the Duchenne marker and increased intensity of expression, have likewise been linked with positive judgments of trustworthiness. The study investigated the interaction of the effects of models' attractiveness and their smiling intensity on impressions of perceived trustworthiness. Participants rated the attractiveness and expressivity of neutral, low intensity, and high intensity smiling images of 45 women models. These images were also presented to a second group of participants who rated trustworthiness. Repeated measures analysis of covariance of the effects of attractiveness and manipulated smile intensity on trustworthiness indicated a main effect for smile intensity: increased smile intensity was associated with greater trustworthiness. Attractiveness also contributed to rated trustworthiness independently of smiling intensity. Results suggested there is an additional contribution of facial expression in creating social impressions of trustworthiness.

  17. Distribution Characteristics of the Intensity and Extreme Intensity of Tropical Cyclones Influencing China

    Institute of Scientific and Technical Information of China (English)

    ZHENG Yongguang; CHEN Jiong; TAO Zuyu

    2014-01-01

    To address the defi ciency of climatological research on tropical cyclones (TCs) infl uencing China, we analyze the distributions of TCs with diff erent intensities in the region, based on the best-track TC data for 1949-2011 provided by the Shanghai Typhoon Institute. We also present the distributions of 50-and 100-yr return-period TCs with diff erent intensities using the Gumbel probability distribution. The results show that TCs with diff erent intensities exert distinctive eff ects on various regions of China and its surrounding waters. The extreme intensity distributions of TCs over these diff erent regions also diff er. Super and severe typhoons mainly infl uence Taiwan Island and coastal areas of Fujian and Zhejiang provinces, while typhoons and TCs with lower intensities infl uence South China most frequently. The probable maximum TC intensity (PMTI) with 50- and 100-yr return periods infl uencing Taiwan Island is below 890 hPa; the PMTI with a 50-yr return period infl uencing the coastal areas of Fujian and Zhejiang provinces is less than 910 hPa, and that with a 100-yr return period is less than 900 hPa;the PMTI with a 50-yr return period infl uencing the coastal areas of Hainan, Guangdong, and the northern part of the South China Sea is lower than 930 hPa, and that with a 100-yr return period is less than 920 hPa. The results provide a useful reference for the estimation of extreme TC intensities over diff erent regions of China.

  18. effect of light curing unit characteristics on light intensity output ...

    African Journals Online (AJOL)

    2013-09-09

    Sep 9, 2013 ... Objective: To determine the characteristics of light curing units (LCUs) in dental clinics in Nairobi and ... generation which has dogged the new generation of. LEDs without ..... Knezevic A, Tarle Z, Meniga A, Sutalo J, Pichler G.

  19. Self-configurable radio receiver system and method for use with signals without prior knowledge of signal defining characteristics

    Science.gov (United States)

    Hamkins, Jon (Inventor); Simon, Marvin K. (Inventor); Divsalar, Dariush (Inventor); Dolinar, Samuel J. (Inventor); Tkacenko, Andre (Inventor)

    2013-01-01

    A method, radio receiver, and system to autonomously receive and decode a plurality of signals having a variety of signal types without a priori knowledge of the defining characteristics of the signals is disclosed. The radio receiver is capable of receiving a signal of an unknown signal type and, by estimating one or more defining characteristics of the signal, determine the type of signal. The estimated defining characteristic(s) is/are utilized to enable the receiver to determine other defining characteristics. This in turn, enables the receiver, through multiple iterations, to make a maximum-likelihood (ML) estimate for each of the defining characteristics. After the type of signal is determined by its defining characteristics, the receiver selects an appropriate decoder from a plurality of decoders to decode the signal.

  20. Improving signal intensities for genes with low-expression on oligonucleotide microarrays

    Directory of Open Access Journals (Sweden)

    Hu Limei

    2004-06-01

    Full Text Available Abstract Background DNA microarrays using long oligonucleotide probes are widely used to evaluate gene expression in biological samples. These oligonucleotides are pre-synthesized and sequence-optimized to represent specific genes with minimal cross-hybridization to homologous genes. Probe length and concentration are critical factors for signal sensitivity, particularly when genes with various expression levels are being tested. We evaluated the effects of oligonucleotide probe length and concentration on signal intensity measurements of the expression levels of genes in a target sample. Results Selected genes of various expression levels in a single cell line were hybridized to oligonucleotide arrays of four lengths and four concentrations of probes to determine how these critical parameters affected the intensity of the signal representing their expression. We found that oligonucleotides of longer length significantly increased the signals of genes with low-expression in the target. High-expressing gene signals were also boosted but to a lesser degree. Increasing the probe concentration, however, did not linearly increase the signal intensity for either low- or high-expressing genes. Conclusions We conclude that the longer the oligonuclotide probe the better the signal intensities of low expressing genes on oligonucleotide arrays.

  1. Clinical significance of the globus pallidus signal intensity ratio in patients with liver cirrhosis

    Energy Technology Data Exchange (ETDEWEB)

    Iwasa, Motoh; Kawamura, Noriko; Hiranuma, Kiyohiko [Kuwana Municipal Hospital, Mie (Japan)] [and others

    1996-11-01

    The object of this study was to evaluate the clinical value of the globus pallidus signal intensity ratio for the subclinical detection of hepatic encephalopathy. This study comprised 25 patients with liver cirrhosis without overt hepatic encephalopathy. There was a high frequency (56%) of patients exhibiting increased signal in the globus pallidus. The pallidal signal was related to the severity of the liver disease. The auditory brain stem reaction was not correlated with the pallidal intensity and laboratory parameters. During the follow-up study, 3 out of 5 patients presenting overt hepatic encephalopathy showed strong pallidal signals. The results of this investigation suggest that abnormal globus pallidus signal may constitute a useful method for the subclinical detection of hepatic encepalopathy. (author)

  2. High signal intensity of the septum pellucidum at MR imaging; Significance in hydrocephalus

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jeong Hee; Kim, Eun Ha; Chung, Chun Phil; Kim, Chang Soo [Maryknoll Hospital, Pusan (Korea, Republic of)

    1994-05-15

    To evaluate the significance of high signal intensity of the septum pellucidum in hydrocephalus on proton density-weighted brain MR images. Authors reviewed the MR images of 418 cases of patients with normal (175 case), hydrocephalic(35 cases), atrophic(58 cases), and other groups(150 cases) retrospectively. We analyzed the signal intensity of the septum pellucidum in the normal group and the incidences of high signal intensities of periventricular area of frontal horn of lateral ventricle(area 1), periventricular area except area 1 (area 2), callososeptal area(area 3), and septum pellucidum(area 4) in the normal and abnormal groups. In the normal group, the septum pellucidum was isointense to the head of caudate nucleus on proton density-weighted image. High signal intensity of the septum pellucidum was seen in 31 cases (22 cases of hydrocephalus, 5 cases of brain atrophy, and 4 cases of others), and showed high specificity(91.4%) for hydrocephalus in spite of low sensitivity(62.9%), as compared with periventricular hyperintensities of other areas. High signal intensity of the septum pellucidum on proton density- weighted image may be caused by transependymal CSF migration in the patients with hydrocephalus, and considered as an additional finding of hydrocephalus in the cases of ventriculomegaly.

  3. A Two-Dimensional Signal Space for Intensity-Modulated Channels

    CERN Document Server

    Karout, Johnny; Kschischang, Frank R; Agrell, Erik

    2012-01-01

    A two-dimensional signal space for intensity- modulated channels is presented. Modulation formats using this signal space are designed to maximize the minimum distance between signal points while satisfying average and peak power constraints. The uncoded, high-signal-to-noise ratio, power and spectral efficiencies are compared to those of the best known formats. The new formats are simpler than existing subcarrier formats, and are superior if the bandwidth is measured as 90% in-band power. Existing subcarrier formats are better if the bandwidth is measured as 99% in-band power.

  4. Laser anemometer signals: visibility characteristics and application to particle sizing.

    Science.gov (United States)

    Adrian, R J; Orloff, K L

    1977-03-01

    The signal visibility characteristics of a dual beam laser anemometer operated in a backscatter mode have been investigated both experimentally and analytically. The analysis is based on Mie's electromagnetic scattering theory for spherical particles and is exact within the limitations of the scattering theory. It is shown that the signal visibility is a function of the ratio of the particle diameter to the fringe spacing in a certain, restricted case; but more generally it also depends on the Mie scattering size parameter, refractive index, the illuminating beam polarization, and the size, shape, and location of the light collecting aperture. The character of backscatter signal visibility differs significantly from the forward scatter case, and it is concluded that backscatter measurements of particle diameters using the visibility sizing technique may not always be possible. Restrictions on the forward scatter application of the visibility sizing method are also discussed.

  5. Signal Intensities in Preoperative MRI Do Not Reflect Proliferative Activity in Meningioma

    Directory of Open Access Journals (Sweden)

    Stefan Schob

    2016-08-01

    Full Text Available BACKGROUND: Identification of high-grade meningiomas in preoperative magnetic resonance imaging (MRI is important for optimized surgical strategy and best possible resection. Numerous studies investigated subjectively determined morphological features as predictors of tumor biology in meningiomas. The aim of this study was to identify the predictive value of more reliable, quantitatively measured signal intensities in MRI for differentiation of high- and low-grade meningiomas and identification of meningiomas with high proliferation rates, respectively. PATIENTS AND METHODS: Sixty-six patients (56 World Health Organization [WHO] grade I, 9 WHO grade II, and 1 WHO grade I were included in the study. Preoperative MRI signal intensities (fluid-attenuated inversion recovery [FLAIR], T1 precontrast, and T1 postcontrast as genuine and normalized values were correlated with Ki-67 expression in tissue sections of resected meningiomas. Differences between the groups (analysis of variance and Spearman rho correlation were computed using SPSS 22. RESULTS: Mean values of genuine signal intensities of meningiomas in FLAIR, T1 native, and T1 postcontrast were 323.9 ± 59, 332.8 ± 67.9, and 768.5 ± 165.3. Mean values of normalized (to the contralateral white matter signal intensities of meningiomas in FLAIR, T1 native, and T1 postcontrast were 1.5 ± 0.3, 0.8 ± 0.1, and 1.9 ± 0.4. There was no significant correlation between MRI signal intensities and WHO grade or Ki-67 expression. Signal intensities did not differ significantly between WHO grade I and II/III meningiomas. Ki-67 expression was significantly increased in high-grade meningiomas compared with low-grade meningiomas (P < 0.01. Objectively measured values of MRI signal intensities (FLAIR, T1 precontrast, and T1 postcontrast enhancement did not distinguish between high-grade and low-grade meningiomas. Furthermore, there was no association between MRI signal intensities and Ki-67 expression

  6. The impact of relative intensity noise on the signal in multiple reference optical coherence tomography

    Science.gov (United States)

    Neuhaus, Kai; Subhash, Hrebesh; Alexandrov, Sergey; Dsouza, Roshan; Hogan, Josh; Wilson, Carol; Leahy, Martin; Slepneva, Svetlana; Huyet, Guillaume

    2016-03-01

    Multiple reference optical coherence tomography (MR-OCT) applies a unique low-cost solution to enhance the scanning depth of standard time domain OCT by inserting an partial mirror into the reference arm of the interferometric system. This novel approach achieves multiple reflections for different layers and depths of an sample with minimal effort of engineering and provides an excellent platform for low-cost OCT systems based on well understood production methods for micro-mechanical systems such as CD/DVD pick-up systems. The direct integration of a superluminescent light-emitting diode (SLED) is a preferable solution to reduce the form- factor of an MR-OCT system. Such direct integration exposes the light source to environmental conditions that can increase fluctuations in heat dissipation and vibrations and affect the noise characteristics of the output spectrum. This work describes the impact of relative intensity noise (RIN) on the quality of the interference signal of MR-OCT related to a variety of environmental conditions, such as temperature.

  7. Numerical ray-tracing approach with laser intensity distribution for LIDAR signal power function computation

    Science.gov (United States)

    Shi, Guangyuan; Li, Song; Huang, Ke; Li, Zile; Zheng, Guoxing

    2016-10-01

    We have developed a new numerical ray-tracing approach for LIDAR signal power function computation, in which the light round-trip propagation is analyzed by geometrical optics and a simple experiment is employed to acquire the laser intensity distribution. It is relatively more accurate and flexible than previous methods. We emphatically discuss the relationship between the inclined angle and the dynamic range of detector output signal in biaxial LIDAR system. Results indicate that an appropriate negative angle can compress the signal dynamic range. This technique has been successfully proved by comparison with real measurements.

  8. New model for gain control of signal intensity to object distance in echolocating bats

    DEFF Research Database (Denmark)

    Nørum, Ulrik; Brinkløv, Signe; Surlykke, Annemarie

    2012-01-01

    Echolocating bats emit ultrasonic calls and listen for the returning echoes to orient and localize prey in darkness. The emitted source level, SL (estimated signal intensity 10 cm from the mouth), is adjusted dynamically from call to call in response to sensory feedback as bats approach objects. ...

  9. [Influence of the difference in start-up echo on signal intensity in the FIESTA sequence].

    Science.gov (United States)

    Naka, Takanori; Takahashi, Mitsuyuki

    2008-11-20

    The FIESTA sequence is a fast imaging method used for various parts in recent years. A constant flip angle (CFA) or linear flip angle (LFA) are used as the start-up echo in many cases. It is reported from CFA, which is the conventional method, that the T1 value and T2 value influence the speed that reaches steady state. However, there is no such report in LFA. Therefore, we examined the influence of the difference of start-up echo method upon signal intensity. In phantoms other than vegetable oil, the difference was not accepted in the change of speed that reaches steady state and the signal intensity in steady-state transit. In LFA, signal intensity of vegetable oil was clearly lower than CFA. The same result was obtained regardless of on or off resonance. From the result, it was thought that it depended on T2/T1 for the speed that reaches steady state. Moreover, the difference in resonant frequency was considered to greatly influence LFA but not CFA. That is, it was suggested by the difference in start-up echo that the signal intensity of fat changes greatly.

  10. Muscle MRI STIR signal intensity and atrophy are correlated to focal lower limb neuropathy severity

    Energy Technology Data Exchange (ETDEWEB)

    Deroide, N.; Mambre, L.; Kubis, Nathalie [Service de Physiologie Clinique-Explorations Fonctionnelles, AP-HP, Hopital Lariboisiere, Paris (France); Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); Bousson, V.; Laredo, J.D. [Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); Radiologie Osteo-articulaire, AP-HP, Hopital Lariboisiere, Paris (France); Vicaut, E. [Universite Paris Diderot, Sorbonne Paris Cite France, Paris (France); URC, AP-HP, Hopital Lariboisiere, Paris (France)

    2014-09-26

    The objective is to determine if muscle MRI is useful for assessing neuropathy severity. Clinical, MRI and electromyography (EMG) examinations were performed in 17 patients with focal lower limb neuropathies. MRI Short Tau Inversion Recovery (STIR) signal intensity, amyotrophy, and muscle fatty infiltration measured after T1-weighted image acquisition, EMG spontaneous activity (SA), and maximal voluntary contraction (MVC) were graded using semiquantitative scores and quantitative scores for STIR signal intensity and were correlated to the Medical Research Council (MRC) score for testing muscle strength. Within this population, subgroups were selected according to severity (mild versus severe), duration (subacute versus chronic), and topography (distal versus proximal) of the neuropathy. EMG SA and MVC MRI amyotrophy and quantitative scoring of muscle STIR intensity were correlated with the MRC score. Moreover, MRI amyotrophy was significantly increased in severe, chronic, and proximal neuropathies along with fatty infiltration in chronic lesions. Muscle MRI atrophy and quantitative evaluation of signal intensity were correlated to MRC score in our study. Semiquantitative evaluation of muscle STIR signal was sensitive enough for detection of topography of the nerve lesion but was not suitable to assess severity. Muscle MRI could support EMG in chronic and proximal neuropathy, which showed poor sensitivity in these patients. (orig.)

  11. Bilateral Pulvinar Signal Intensity Decrease on T2-Weighted Images in Patients with Aspartylglucosaminuria

    Energy Technology Data Exchange (ETDEWEB)

    Autti, T.; Loennqvist, T.; Joensuu, R. (Helsinki Medical Imaging Center, Univ. of Helsinki, Helsinki (Finland))

    2008-07-15

    Background: Aspartylglucosaminuria (AGU) is an autosomal recessive lysosomal disease caused by deficiency of aspartylglucosaminidase. A thalamic T2 signal intensity decrease is associated with lysosomal diseases. Purpose: To investigate thalamic signal intensity in AGU by performing a retrospective review of brain magnetic resonance (MR) imaging studies of AGU patients. Material and Methods: A total of 25 MR examinations were available for 11 patients aged between 3 and 32 years (four patients underwent bone marrow transplantation). Of these, 13 examinations were performed after bone marrow transplantation. Five patients had from two to six examinations, and six patients had one examination each. In every patient, the diagnosis of AGU was confirmed by blood and urine tests. Eighteen examinations were performed with a 1.0T imager including dual spin-echo T2 and proton density (PD) axial and coronal images, and 10 examinations also included T1-weighted images. Seven examinations were performed with a 1.5T imager including turbo spin-echo axial and coronal T2-weighted images and axial fluid-attenuated inversion recovery (FLAIR) images; three examinations included T1-weighted three-dimensional magnetization-prepared rapid acquisition gradient-echo (3D MPRAGE) images. The signal intensity of the thalamus and pulvinar in every sequence was compared to that of the putamina. Results: In AGU, thalamic alterations were first detectable on T2-weighted images (25 examinations in 11 patients) from the age of 3 years 6 months, showing decreased signal intensity in 21 of 24 examinations. T1-weighted images (13 examinations) showed slightly increased thalamic signal intensity in five out of seven examinations from the age of 7 years, and PD images (19 examinations) showed decreased signal intensity from the age of 16 years (three examinations). The pulvinar showed decreased signal intensity on spin-echo T2-weighted images for 14 of 18 examinations or on FLAIR sequences for seven

  12. The impact of signal intensity and image distortion magnetic resonance imaging in the orthopedic prosthetic metal

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyeong Gyun [CHA Univ., Gumi (Korea, Republic of); Choi, Seong Dae [Kumoh National Institute of Technology, Gumi (Korea, Republic of)

    2012-12-15

    Used as an ingredient in the hospital for orthopedic prosthetic stainless and titanium metal the same size as on the MRI diagnostic value of imaging were compared. Center of images, background high band portion of the video signal is converted into a weighted intensity values Normal images and compared. The area of normal slice and also the distortion of images and cross-sectional imaging of a range of quantitative and sagittal planes were compared. As a result, the periphery high band signal intensity values of Stainless video phantom 2, pig bone 1.8, Titanium imaging of phantom 1.7 has higher value than Normal video pig bone 1.3 times the signal strength rivers. MRI distortion of the shape and the distortions of the range, if the cross-sectional area compared to Normal Slice Stainless case of phantom 65.8 %, pig bone 61.5 %, Titanium distortion phantom 23.1 %, pig bone 38.5 % of the range of community found. In this experiment, as a result, MRI was found to be Titanium more diagnostic value than the specimen with respect to the signal intensity weighted value and low distortion range, Stainless.

  13. Vocal signals in a tropical avian species, the redvented bulbul Pycnonotus cafer: their characteristics and importance

    Indian Academy of Sciences (India)

    Anil Kumar; Dinesh Bhatt

    2000-12-01

    Acoustic signals play an important role in the lives of birds. Almost all avian species produce vocal signals in a variety of contexts either in the form of calls or songs or both. In the present study different types of vocal signals of the tropical avian species Pycnonotus cafer were characterized on the basis of their physical characteristics and context of production. This species used six types of vocal signals: contact signals, roosting signals, alarm signals, twittering signals, distress signals and begging signals. Two types of alarm signals are produced based on predation pressure. These signals are dissimilar in all physical characteristics except for dominant frequency. Although alarm signal type I and roosting signals are phonetically similar, they have completely different sonogram characteristics.

  14. Reference-tissue correction of T2-weighted signal intensity for prostate cancer detection

    Science.gov (United States)

    Peng, Yahui; Jiang, Yulei; Oto, Aytekin

    2014-03-01

    The purpose of this study was to investigate whether correction with respect to reference tissue of T2-weighted MRimage signal intensity (SI) improves its effectiveness for classification of regions of interest (ROIs) as prostate cancer (PCa) or normal prostatic tissue. Two image datasets collected retrospectively were used in this study: 71 cases acquired with GE scanners (dataset A), and 59 cases acquired with Philips scanners (dataset B). Through a consensus histology- MR correlation review, 175 PCa and 108 normal-tissue ROIs were identified and drawn manually. Reference-tissue ROIs were selected in each case from the levator ani muscle, urinary bladder, and pubic bone. T2-weighted image SI was corrected as the ratio of the average T2-weighted image SI within an ROI to that of a reference-tissue ROI. Area under the receiver operating characteristic curve (AUC) was used to evaluate the effectiveness of T2-weighted image SIs for differentiation of PCa from normal-tissue ROIs. AUC (+/- standard error) for uncorrected T2-weighted image SIs was 0.78+/-0.04 (datasets A) and 0.65+/-0.05 (datasets B). AUC for corrected T2-weighted image SIs with respect to muscle, bladder, and bone reference was 0.77+/-0.04 (p=1.0), 0.77+/-0.04 (p=1.0), and 0.75+/-0.04 (p=0.8), respectively, for dataset A; and 0.81+/-0.04 (p=0.002), 0.78+/-0.04 (pmuscle yielded the most consistent results between GE and Phillips images. Correction of T2-weighted image SI in reference to three types of extra-prostatic tissue can improve its effectiveness for differentiation of PCa from normal-tissue ROIs, and correction in reference to the levator ani muscle produces consistent T2-weighted image SIs between GE and Phillips MR images.

  15. Response Characteristics of Plant Bioelectric Potential to Light Intensity Indoor and Outdoor

    Science.gov (United States)

    Shimbo, Tatsuya; Fujii, Masaki; Sawada, Ayako; Oyabu, Takashi; Kimura, Haruhiko

    Plant is affected by environmental factors. For example, these are temperature, humidity and light intensity. The light intensity affected strongly to the plant. The plant produces glucose and oxygen with photosynthesis. Moreover, light intensity is important to purify the contaminants in the atmosphere. In this study, it was examined whether the plant is affected by temperature, wind grade and soil moisture using bioelectric potential characteristics of the plant. Especially plant bioelectric potential to light intensity change was measured. The measurement was carried out in indoor and outdoor. As for the result, the differences of plant bioelectric potential characteristics in the indoor and outdoor were recognized. At that analysis, the integrated value of plant bioelectric potential for 1 minute (vm1) was adopted. Moreover, a high correlation was indicated between the vm1 and light intensity. The correlation coefficient was R2=0.94. It becomes obvious that the plant is affected strongly by light intensity and the plant can understand the environmental factors like light intensity. The characteristics are found by measuring bioelectric potential of the plant. The environmental sensing can be possible by the use of the plant bioelectric potential.

  16. Signal Intensity of Superb Microvascular Imaging Correlates with the Severity of Acute Cholecystitis

    Directory of Open Access Journals (Sweden)

    Minoru Tomizawa

    2016-08-01

    Full Text Available Evaluation of the severity of acute cholecystitis is critical for the management of this condition. Superb microvascular imaging (SMI enables the assessment of slow blood flow of small vessels without any contrast medium. An 84-year-old man visited our hospital with right upper abdominal pain. Computed tomography and abdominal ultrasonography showed a slight thickening of the gallbladder. White blood cell count and C-reactive protein levels were elevated. He was diagnosed with acute cholecystitis and treated conservatively with antibiotics. Two days later, his condition worsened and percutaneous transhepatic gallbladder drainage (PTGBD was performed. The patient recovered and was discharged, and his drainage was withdrawn 7 days later. On admission, color-coded SMI (cSMI showed pulsatory signals on the slightly thickened gallbladder wall. On the day of PTGBD, the intensity of the signal on cSMI had increased. Once the patient was cured, no further signal was observed on the gallbladder wall with either cSMI or mSMI. In conclusion, the strong pulsatory signal correlated with the severity of acute cholecystitis observed with cSMI and mSMI. Illustrating the signal intensity is useful for the evaluation of the severity of acute cholecystitis.

  17. Signal Intensity of Superb Microvascular Imaging Correlates with the Severity of Acute Cholecystitis

    Science.gov (United States)

    Tomizawa, Minoru; Shinozaki, Fuminobu; Motoyoshi, Yasufumi; Sugiyama, Takao; Yamamoto, Shigenori; Ishige, Naoki

    2016-01-01

    Evaluation of the severity of acute cholecystitis is critical for the management of this condition. Superb microvascular imaging (SMI) enables the assessment of slow blood flow of small vessels without any contrast medium. An 84-year-old man visited our hospital with right upper abdominal pain. Computed tomography and abdominal ultrasonography showed a slight thickening of the gallbladder. White blood cell count and C-reactive protein levels were elevated. He was diagnosed with acute cholecystitis and treated conservatively with antibiotics. Two days later, his condition worsened and percutaneous transhepatic gallbladder drainage (PTGBD) was performed. The patient recovered and was discharged, and his drainage was withdrawn 7 days later. On admission, color-coded SMI (cSMI) showed pulsatory signals on the slightly thickened gallbladder wall. On the day of PTGBD, the intensity of the signal on cSMI had increased. Once the patient was cured, no further signal was observed on the gallbladder wall with either cSMI or mSMI. In conclusion, the strong pulsatory signal correlated with the severity of acute cholecystitis observed with cSMI and mSMI. Illustrating the signal intensity is useful for the evaluation of the severity of acute cholecystitis. PMID:27721732

  18. MR imaging of degenerative lumbar disc disease emphasizing on signal intensity changes in vertebral body

    Energy Technology Data Exchange (ETDEWEB)

    Toyoda, Keiko; Ida, Masahiro; Murakami, Yoshitaka; Harada, Junta; Tada, Shimpei (Jikei Univ., Tokyo (Japan). School of Medicine)

    1992-12-01

    Magnetic resonance imaging was performed in 400 patients with degenerative disc disease. Signal changes and their sites in the vertebral body were classified and referred to narrowing of the intervertebral disc space. MR findings were compared with those of plain roentgenograms of the lumbar spine. Signal changes in the vertebral body were noted in 83 cases (102 vertebral bodies). Low-intensity abnormality on both T1- and T2-weighted images (WI) was the most common finding, and was most frequently seen at the end plate and/or the angle. These changes were correlated with narrowing of the disc space and osteosclerosis on the plain roentgenogram of the lumbar spine. Signal changes occasionally occurred in the inner region of the vertebral body, and these lesions tended to show a high-intensity abnormality on T1-WI. We conclude that signal changes in degenerative disc disease are not specific, but are sometimes difficult to distinguish from the signal changes in other conditions such as spinal tumor or bone marrow disorder. (author).

  19. Intracranial lesions with high signal intensity on T1-weighted MR images – review of pathologies

    Science.gov (United States)

    Zimny, Anna; Zińska, Lidia; Bladowska, Joanna; Neska-Matuszewska, Małgorzata; Sąsiadek, Marek

    2013-01-01

    Summary In the article we present pathological intracranial substances and lesions, which produce high signal intensity on T1-weighted MR images. Six groups of substances are discussed: 1. Gadolinium – based contrast agents, 2.hemoglobin degradation products (intra- and extra-cellular methemoglobin), 3. lipid-containing lesions (lipoma, dermoid cyst, implanted fatty materials, laminar cortical necrosis), 4. substances with high concentration of proteins (colloid cyst, craniopharyngioma, Rathke’s cleft cyst, ectopic posterior pituitary gland), 5. melanin (metastatic melanoma), 6. lesions containing mineral substances such as: calcium (calcifications, Fahr’s disease), copper (Wilson’s disease) and manganese (hepatic encephalopathy, manganese intoxication in intravenous drug abusers). Appropriate interpretation of signal intensity as well as analysis of location of lesions and clinical symptoms enables planning of further diagnostics and, in many cases, establishing the final diagnosis based on MR examination. PMID:24505222

  20. Prediction of postnatal outcomes in congenital diaphragmatic hernia using MRI signal intensity of the fetal lung.

    Science.gov (United States)

    Terui, K; Omoto, A; Osada, H; Hishiki, T; Saito, T; Sato, Y; Nakata, M; Komatsu, S; Ono, S; Yoshida, H

    2011-04-01

    Prognostic prediction in prenatally diagnosed congenital diaphragmatic hernia (CDH) is needed. The aim of the study was to evaluate magnetic resonance imaging (MRI) signal intensity of the fetal lung as a predictor of prognosis in CDH. The subjects consisted of 12 fetuses with prenatally diagnosed CDH, who were treated soon after the birth in our institution. They all underwent MRI at 29 to 37 weeks of gestation. The ratio of the lung signal intensity to the spinal fluid signal intensity (L/SF) was calculated using region-of-interest analysis of T2-weighted images. The relationship between L/SF and clinical data was then examined. L/SF were significantly larger in survivors compared with deaths (0.815 vs 0.614, P<0.05). In survivors, L/SF significantly correlated with duration of tracheal intubation (rs=-0.938, P<0.01). L/SF is a unique factor to predict the survival prognosis and likely to quantify the degree of pulmonary hypoplasia in CDH.

  1. Signal intensity loss of the intervertebral discs in the cervical spine of young patients on fluid sensitive sequences

    Energy Technology Data Exchange (ETDEWEB)

    Bruin, F. de; Horst, S. ter; Bloem, J.L.; Reijnierse, M. [Leiden University Medical Center, Department of Radiology, C2-S, Albinusdreef 2, PO box 9600, Leiden (Netherlands); Berg, R. van den; Hooge, M. de; Gaalen, F. van; Heijde, D. van der [Leiden University Medical Center, Department of Rheumatology, Leiden (Netherlands); Fagerli, K.M. [Diakonhjemmet Hospital, Department of Rheumatology, Oslo (Norway); Landewe, R. [Amsterdam Medical Center, Department of Rheumatology, Amsterdam (Netherlands); Oosterhout, M. van [Groene Hartziekenhuis, Department of Rheumatology, Gouda (Netherlands)

    2016-03-15

    To evaluate the signal intensity (SI) of the intervertebral discs of the cervical spine on magnetic resonance (MR) fluid sensitive sequences, and correlate this to secondary signs of degeneration on MR and radiographs as well as to age. A total of 265 patients aged ≥16 with back pain (≥3-months, <2-year, onset <45-years) from the SPondyloArthritis Caught Early (SPACE) cohort were included. Sagittal 1.5 T MR images and lateral radiographs of the cervical spine were independently evaluated by two readers for: SI of the intervertebral discs using a grading system based of Pfirrmann (grade 1 normal/bright SI; 2 inhomogeneous/bright SI; 3 inhomogeneous/mildly decreased SI; 4 inhomogeneous/markedly decreased SI; 5 signal void), disc herniation and Modic changes (MRI) and disc space narrowing, osteophytes and sclerosis (radiograph). Readers were blinded for clinical information. Descriptive statistics were used for characteristics and prevalence of findings, and regression analysis was used for age and grades. Of 265 patients (36 % male, mean age 30), 221 (83 %) patients had 1 to 6 discs (median 4) with decreased SI. Of 1,590 discs, 737 (46 %) were grade 1; 711 (45 %) grade 2; 133 (8 %) grade 3; 8 (1 %) grade 4 and 1 (0 %) grade 5. Secondary signs of degeneration were rare and seen predominantly in C5-C7 and appear to be related to signal loss grade 3 and 4. Low signal intensity of intervertebral discs in absence of secondary degenerative signs in the cervical spine on fluid sensitive MR images might be pre-existing and part of the natural course. (orig.)

  2. Abdominal infections in the intensive care unit: characteristics, treatment and determinants of outcome

    NARCIS (Netherlands)

    Waele, J. De; Lipman, J.; Sakr, Y.; Marshall, J.C.; Vanhems, P.; Barrera Groba, C.; Leone, M.; Vincent, J.L.; Pickkers, P.

    2014-01-01

    BACKGROUND: Abdominal infections are frequent causes of sepsis and septic shock in the intensive care unit (ICU) and are associated with adverse outcomes. We analyzed the characteristics, treatments and outcome of ICU patients with abdominal infections using data extracted from a one-day point preva

  3. Relationship between performance at different exercise intensities and skeletal muscle characteristics

    DEFF Research Database (Denmark)

    Iaia, F Marcello; Perez-Gomez, Jorge; Thomassen, Martin

    2011-01-01

    The hypothesis investigated whether exercise performance over a broad range of intensities is determined by specific skeletal muscle characteristics. Seven subjects performed 8-10 exhaustive cycle trials at different work loads ranging from 150 to 700 W (150 min - 20 s). No relationships between...... the performance times at high and low work loads were observed. A relationship (P...

  4. Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis

    Science.gov (United States)

    Zhou, Yufan; Yao, Juan; Ding, Yuanzhao; Yu, Jiachao; Hua, Xin; Evans, James E.; Yu, Xiaofei; Lao, David B.; Heldebrant, David J.; Nune, Satish K.; Cao, Bin; Bowden, Mark E.; Yu, Xiao-Ying; Wang, Xue-Lin; Zhu, Zihua

    2016-12-01

    In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid-liquid and liquid-vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecular signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable for use of in situ liquid SIMS to study solid-liquid and liquid-vacuum interfaces.

  5. Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis

    Science.gov (United States)

    Zhou, Yufan; Yao, Juan; Ding, Yuanzhao; Yu, Jiachao; Hua, Xin; Evans, James E.; Yu, Xiaofei; Lao, David B.; Heldebrant, David J.; Nune, Satish K.; Cao, Bin; Bowden, Mark E.; Yu, Xiao-Ying; Wang, Xue-Lin; Zhu, Zihua

    2016-09-01

    In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid-liquid and liquid-vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecular signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable for use of in situ liquid SIMS to study solid-liquid and liquid-vacuum interfaces.

  6. Improving the Molecular Ion Signal Intensity for In Situ Liquid SIMS Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Yufan; Yao, Juan; Ding, Yuanzhao; Yu, Jiachao; Hua, Xin; Evans, James E.; Yu, Xiaofei; Lao, David B.; Heldebrant, David J.; Nune, Satish K.; Cao, Bin; Bowden, Mark E.; Yu, Xiao-Ying; Wang, Xue-Lin; Zhu, Zihua

    2016-09-06

    In situ liquid secondary ion mass spectrometry (SIMS) enabled by system for analysis at the liquid vacuum interface (SALVI) has proven to be a promising new tool to provide molecular information at solid–liquid and liquid–vacuum interfaces. However, the initial data showed that useful signals in positive ion spectra are too weak to be meaningful in most cases. In addition, it is difficult to obtain strong negative molecular ion signals when m/z>200. These two drawbacks have been the biggest obstacle towards practical use of this new analytical approach. In this study, we report that strong and reliable positive and negative molecular signals are achievable after optimizing the SIMS experimental conditions. Four model systems, including a 1,8-diazabicycloundec-7-ene (DBU)-base switchable ionic liquid, a live Shewanella oneidensis biofilm, a hydrated mammalian epithelia cell, and an electrolyte popularly used in Li ion batteries were studied. A signal enhancement of about two orders of magnitude was obtained in comparison with non-optimized conditions. Therefore, molecular ion signal intensity has become very acceptable to use for in situ liquid SIMS to study solid–liquid and liquid–vacuum interfaces.

  7. Signal intensity of magnetic resonance imaging of pituitary adenoma reflects its collagen content

    Institute of Scientific and Technical Information of China (English)

    Hui Wang; Xianrui Yuan; Weixi Jiang

    2006-01-01

    BACKGROUND:At present,results of a few studies demonstrate that preoperative magnetic resonance imagling (MRI)examination reveals the texture of pituitary adenoma,I.e.on the T2-weighted image,solid pituitary adenoma shows weak signal and soft one shows strong signal.Also,solid pituitary adenoma is caused by fibrosis,which is confirmlea.However,some key problems are still in question and disputation,such as how to exactly quantize MRI signal intensity,which signal is used as prediction index,and the relationship of MRI signal and collagen content which reflects the texture of pituitary adenoma,and so on.OBJECTIVE:To observe the relationship of MRI signal intensity of different textures of pituitary adenoma and its collagen content,and investigate the best prediction index of the texture of pituitary adenoma.DESIGN:Case-control observation.SETTING:Department of Neurosurgery,Third Hospital Affiliated to Sun Yat-sen University;Department of Neurosurgery,Xiangya Hospital,Central South University.PARTICIPANTS:Fifty-seven patients with pituitary adenoma,including 32 males and 25 females,aged 20 to 65 years,who received treatment in the Department of Neurosurgery,Xiangya Hospital,Central South University during June 2003 to January 2004.The involved patients were all diagnosed by MRI and confirmed by pathological resection.Informed consents were obtained from all the patients.The samples of above-mentioned patients resected by operation were fixed with 40 g/L formaldehyde for sirius red staining.METHODS:①Accordling to the texture of pituitary adenoma observed in the operation:The 57 samples of pituitary adenoma were divided into 2 groups:non-flbrosis group(n=49)and fibrosis group(n=8).In the non-fibrosis group,the texture of pituitary adenoma was soft,I.e.pituitary adenoma tissue automatically flew out,and could be aspirated by aspirater or erased by curette,and the superior part of saddle could fall in the saddle,In the fibrosis group,pituitary adenoma tissue could be

  8. High signal intensity of globus pallidus on T1-weighted MRI in liver cirrhosis patients. Clinical and pathological study

    Energy Technology Data Exchange (ETDEWEB)

    Ihara, Hiroko [Wakayama Medical Coll. (Japan)

    1998-08-01

    In some patients with liver cirrhosis, the globus pallidus shows high signal intensity on T1-weighted MRI. The relationship was examined between high signal intensity on T1-weighted images and pathological conditions such as liver function, portal venous pressure and metal concentrations in brain. The signal of the globus pallidus on T1-weighted imaging became highly enhanced in accordance with prolongation of prothrombin time, deterioration of ICG R{sub 15}, or decrease in choline esterase and the Fisher ratio. Furthermore, the high signal intensity was also seen in patients with high portal pressure and large varices. In histopathological study, remarkable atrophy and loss of nerve cells were observed in globus pallidus with high signal intensity on T1-weighted imaging, changes that were similar to those in with patients with manganese poisoning. The manganese concentration in autopsied globus pallidus with high signal intensity on T1-weighted imaging showed a 9.5-fold increase compared with that with normal intensity. In conclusion, the deposition of manganese in the globus pallidus, which is accompanied with the nerve cell deciduation, brings about the high signal intensity of the globus pallidus on T1-weighted MRI in patients with liver cirrhosis. (author)

  9. Arterial spin-labeling assessment of normalized vascular intratumoral signal intensity as a predictor of histologic grade of astrocytic neoplasms.

    Science.gov (United States)

    Furtner, J; Schöpf, V; Schewzow, K; Kasprian, G; Weber, M; Woitek, R; Asenbaum, U; Preusser, M; Marosi, C; Hainfellner, J A; Widhalm, G; Wolfsberger, S; Prayer, D

    2014-03-01

    Pulsed arterial spin-labeling is a noninvasive MR imaging perfusion method performed with the use of water in the arterial blood as an endogenous contrast agent. The purpose of this study was to determine the inversion time with the largest difference in normalized intratumoral signal intensity between high-grade and low-grade astrocytomas. Thirty-three patients with gliomas, histologically classified as low-grade (n = 7) or high-grade astrocytomas (n = 26) according to the World Health Organization brain tumor classification, were included. A 3T MR scanner was used to perform pulsed arterial spin-labeling measurements at 8 different inversion times (370 ms, 614 ms, 864 ms, 1114 ms, 1364 ms, 1614 ms, 1864 ms, and 2114 ms). Normalized intratumoral signal intensity was calculated, which was defined by the signal intensity ratio of the tumor and the contralateral normal brain tissue for all fixed inversion times. A 3-way mixed ANOVA was used to reveal potential differences in the normalized vascular intratumoral signal intensity between high-grade and low-grade astrocytomas. The difference in normalized vascular intratumoral signal intensity between high-grade and low-grade astrocytomas obtained the most statistically significant results at 370 ms (P = .003, other P values ranged from .012-.955). The inversion time by which to differentiate high-grade and low-grade astrocytomas by use of normalized vascular intratumoral signal intensity was 370 ms in our study. The normalized vascular intratumoral signal intensity values at this inversion time mainly reflect the labeled intra-arterial blood bolus and therefore could be referred to as normalized vascular intratumoral signal intensity. Our data indicate that the use of normalized vascular intratumoral signal intensity values allows differentiation between low-grade and high-grade astrocytomas and thus may serve as a new, noninvasive marker for astrocytoma grading.

  10. Characteristic parameters of electromagnetic signals from a human heart system

    Institute of Scientific and Technical Information of China (English)

    Liu Xin-Yuan; Pei Liu-Qing; Wang Yin; Zhang Su-Ming; Gao Hong-Lei; Dai Yuan-Dong

    2011-01-01

    The electromagnetic field of a human heart system is a bioelectromagnetic field. Electrocardiography (ECG)and magnetocardiography (MCG)are both carriers of electromagnetic information about the cardiac system, and they are nonstationary signals. In this study, ECG and MCG data from healthy subjects are acquired;the MCG data are captured using a high-T, radio frequency superconducting quantum interference device (HTc rf SQUIDs)and the QRS complexes in these data are analysed by the evolutionary spectrum analysis method. The results show that the quality factor Q and the central frequency fz of the QRS complex evolutionary spectrum are the characteristic parameters (CHPs)of ECG and MCG in the time-frequency domain. The confidence intervals of the mean values of the CHPs are estimated by the Student t distribution method in mathematical statistics. We believe that there are threshold ranges of the mean values of Q and fz for healthy subjects. We have postulated the following criterion:if the mean values of CHPs are in the proper ranges, the cardiac system is in a normal condition and it possesses the capability of homeostasis. In contrast, if the mean values of the CHPs do not lie in the proper ranges, the homeostasis of the cardiac system is lacking and some cardiac disease may follow. The results and procedure of MCG CHPs in the study afford a technological route for the application of HTc rf SQUIDs in cardiology.

  11. Signal quality estimation with multichannel adaptive filtering in intensive care settings.

    Science.gov (United States)

    Silva, Ikaro; Lee, Joon; Mark, Roger G

    2012-09-01

    A signal quality estimate of a physiological waveform can be an important initial step for automated processing of real-world data. This paper presents a new generic point-by-point signal quality index (SQI) based on adaptive multichannel prediction that does not rely on ad hoc morphological feature extraction from the target waveform. An application of this new SQI to photoplethysmograms (PPG), arterial blood pressure (ABP) measurements, and ECG showed that the SQI is monotonically related to signal-to-noise ratio (simulated by adding white Gaussian noise) and to subjective human quality assessment of 1361 multichannel waveform epochs. A receiver-operating-characteristic (ROC) curve analysis, with the human "bad" quality label as positive and the "good" quality label as negative, yielded areas under the ROC curve of 0.86 (PPG), 0.82 (ABP), and 0.68 (ECG).

  12. Assess pain intensity using photoplethysmography signal in chronic myofascial pain syndrome.

    Science.gov (United States)

    Ye, Jing-Jhao; Lee, Kuan-Ting; Chou, Ying-Yu; Sie, Hung-Hai; Huang, Ju-Nan; Chuang, Chiung-Cheng

    2017-05-14

    Efficacy of pain assessment is the basis for effective therapy. Clinically, assessing pain is by subjective scale, but these methods have some shortcomings. Therefore, studies have been conducted on assessment of pain using physiological signals. Photoplethysmography (PPG) signal provides much information about the cardiovascular system. PPG- derived parameters (PPG parameters) reflect nociceptive stimulation, and obtain an approximation of the R-R interval from PPG period. The aim of this study was to evaluate PPG signal for assessment of pain intensity in chronic myofascial pain syndrome (MPS) patients. This study recruited 37 patients with chronic MPS, all of them were treated with electrotherapy and thermotherapy. The difference of PPG parameters between pre- and post- therapy, and correlation between pulse rate variability (PRV) and heart rate variability (HRV) were determined. We also obtained patients' pain intensity scores by Visual analogue scale (VAS), visual rating scale (VRS) and Wong-Banker face pain rating scale (Wong-Banker). PPG and PRV/HRV parameters showed significant difference between pre- and post-treatment. The variation trend of PRV was similar with HRV in heart rate (HR), R-R interval (RRI), low frequency (LF), high frequency (HF), and LF/HF; in addition, a high correlation between the parameters was observed either in the pre- or post-therapy. PPG parameters indicated increased sympathetic tone. The results of the study indicated that PRV may substitute for HRV in assessment of pain intensity in chronic MPS reflected parasympathetic nervous tone increase, and PPG parameters might reflect stress stimulation on skin. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  13. MR imaging of the biliary tract with Gd-EOB-DTPA: Effect of liver function on signal intensity

    Energy Technology Data Exchange (ETDEWEB)

    Takao, Hidemasa, E-mail: takaoh-tky@umin.ac.jp [Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Akai, Hiroyuki; Tajima, Taku [Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Kiryu, Shigeru [Department of Radiology, Institute of Medical Science, University of Tokyo, 74-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639 (Japan); Watanabe, Yasushi [Department of Radiological Technology, The University of Tokyo Hospital, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Imamura, Hiroshi [Department of Hepatobiliary-Pancreatic Surgery, Juntendo University School of Medicine, 3-1-3 Hongo, Bunkyo-ku, Tokyo 113-8431 (Japan); Akahane, Masaaki; Yoshioka, Naoki [Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Kokudo, Norihiro [Hepato-Biliary-Pancreatic Surgery Division, Department of Surgery, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan); Ohtomo, Kuni [Department of Radiology, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655 (Japan)

    2011-02-15

    Objective: To quantitatively evaluate the signal intensity of the biliary tract in gadolinium ethoxybenzyl diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced magnetic resonance (MR) imaging and to investigate the effect of liver function on the signal intensity of the biliary tract. Materials and methods: A total of 32 patients with and without chronic liver disease (normal liver group, n = 15; chronic liver disease group, n = 17) were included in this study. All patients were prospectively enrolled for evaluation of known or suspected focal liver lesions. In the chronic liver disease group, the etiologies were chronic hepatitis C virus infection (n = 12) and chronic hepatitis B virus infection (n = 5). The median Child-Pugh score was 5 (range, 5-7). Each patient received the standard dose of Gd-EOB-DTPA (0.025 mmol/kg of body weight). Post-contrast T1-weighted MR images were obtained at 5, 10, 15, 20, 25, and 30 min after administration of Gd-EOB-DTPA. Maximum signal intensities (SIs) of the right and left hepatic ducts, common hepatic duct, and common bile duct were measured. Relative signal intensity was calculated as follows: relative SI = maximum SI{sub bileduct}/mean SI{sub muscle}. Serum albumin level, serum total bilirubin level, prothrombin time, indocyanine green retention rate at 15 min (ICG-R15), and estimated glomerular filtration rate were entered into regression analysis. Results: The signal intensity of the bile duct reached a peak 30 min after administration of Gd-EOB-DTPA. The mean relative signal intensity of the right and left hepatic ducts at the peak time point was not significantly different between the two groups, while increase in signal intensity was delayed in the chronic liver disease group. The mean relative signal intensity of the common hepatic duct and that of the common bile duct at the peak time point were significantly different between the two groups (Wilcoxon rank-sum test, P = 0.03, respectively). Stepwise regression

  14. Twisted ovarian fibroma with high signal intensity on T1-weighted MR image: a new sign of torsion of ovarian tumors?

    Energy Technology Data Exchange (ETDEWEB)

    Minutoli, F.; Blandino, A.; Gaeta, M.; Pandolfo, I. [Inst. of Radiologic Sciences, University of Messina (Italy); Lentini, M. [Dept. of Human Pathology, University of Messina (Italy)

    2001-07-01

    Torsion of ovarian tumors is often difficult to diagnose, because of non-specific clinical, laboratory, and imaging findings. We report a case of twisted ovarian fibroma whose main characteristic was the presence of large areas of high signal intensity on both T1- and T2-weighted MR images due to the passive congestion of the mass. This previously unreported finding should be considered a sign of ovarian torsion and may facilitate prompt surgical intervention. (orig.)

  15. Influence of light intensity on growth and physiological characteristics of common sage (Salvia officinalis L.

    Directory of Open Access Journals (Sweden)

    George Zervoudakis

    2012-02-01

    Full Text Available The aim of this work was to investigate the effects of four different light intensities on the growth characteristics, physiological parameters and leaf photosynthetic pigments of Salvia officinalis L. The plant's dry mass, number of the leaves and physiological parameters indicated a strong positive correlation with the light intensity. On the other hand, the plant's height and leaf photosynthetic pigments were increased at low light treated plants. These results suggest that the aromatic herb Salvia officinalis L. is adaptable to different light environments.

  16. Nonlinear Characteristics of an Intense Laser Pulse Propagating in Partially Stripped Plasmas

    Institute of Scientific and Technical Information of China (English)

    HU Qiang-Lin; LIU Shi-Bing; CHEN Tao; JIANG Yi-Jian

    2005-01-01

    The nonlinear optic characteristics of an intense laser pulse propagating in partially stripped plasmas are investigated analytically. The phase and group velocity of the laser pulse propagation as well as the three general expressions governing the nonlinear optic behavior, based on the photon number conservation, are obtained by considering the partially stripped plasma as a nonlinear optic medium. The numerical result shows that the presence of the bound electrons in partially stripped plasma can significantly change the propagating property of the intense laser pulse.

  17. Feature Extraction Method of Rolling Bearing Fault Signal Based on EEMD and Cloud Model Characteristic Entropy

    Directory of Open Access Journals (Sweden)

    Long Han

    2015-09-01

    Full Text Available The randomness and fuzziness that exist in rolling bearings when faults occur result in uncertainty in acquisition signals and reduce the accuracy of signal feature extraction. To solve this problem, this study proposes a new method in which cloud model characteristic entropy (CMCE is set as the signal characteristic eigenvalue. This approach can overcome the disadvantages of traditional entropy complexity in parameter selection when solving uncertainty problems. First, the acoustic emission signals under normal and damage rolling bearing states collected from the experiments are decomposed via ensemble empirical mode decomposition. The mutual information method is then used to select the sensitive intrinsic mode functions that can reflect signal characteristics to reconstruct the signal and eliminate noise interference. Subsequently, CMCE is set as the eigenvalue of the reconstructed signal. Finally, through the comparison of experiments between sample entropy, root mean square and CMCE, the results show that CMCE can better represent the characteristic information of the fault signal.

  18. MR assessment of fetal lung development using lung volumes and signal intensities

    Energy Technology Data Exchange (ETDEWEB)

    Keller, Thomas M.; Michel, Sven C.A.; Marincek, Borut [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091, Zurich (Switzerland); Rake, Annett; Wisser, Josef [Department of Obstetrics, University Hospital Zurich, Raemistrasse 100, 8091, Zurich (Switzerland); Seifert, Burkhardt [Department of Biostatistics, University of Zurich, Sumatrastrasse 30, 8006, Zurich (Switzerland); Kubik-Huch, Rahel A. [Institute of Diagnostic Radiology, University Hospital Zurich, Raemistrasse 100, 8091, Zurich (Switzerland); Institute of Radiology, Kantonsspital Baden, 5404, Baden (Switzerland)

    2004-06-01

    The purpose of this study was to evaluate the monitoring and diagnostic potential of MRI in fetal lung development and disease using lung volume and signal intensity changes through gestation. Thirty-five healthy fetuses (22-42 weeks) were examined on a 1.5- T MR system using sagittal T2w single-shot fast spin-echo imaging (TR indefinite, TE 90 ms, slice thickness/gap 3-5/0 mm, FOV 26-40 cm, NEX 0.5). Fetal body and lung were segmented manually and volumes calculated. Signal intensities (SI) of fetal lung and three reference values were measured on the section best displaying the lung. Regions of interests were defined by including the maximal organ area possible. The following SI ratios were generated: lung/liver, lung/amniotic fluid, lung/muscle, liver/fluid and liver/muscle. Volumes and ratios were correlated with gestational age. Data from seven fetuses with pulmonary pathology were compared with these normative values. Absolute lung volume varied from 12.3 to 143.5 cm{sup 3} in correlation with gestational age (P<0.001); lung volume relative to total body volume ranged from 1.6 to 5.0%, decreasing with gestational age (P=0.001). (orig.)

  19. Evaluation of a tailored injection profile (TIP) algorithm for uniform contrast-enhanced signal intensity profiles in MR angiography.

    Science.gov (United States)

    Wilson, Gregory J; Maki, Jeffrey H

    2016-12-01

    To evaluate a contrast agent injection method that provides constant magnetic resonance imaging (MRI) signal intensity throughout a contrast-enhanced MR angiography acquisition. A tailored injection profile (TIP) algorithm was developed that used the signal intensity profile from a test bolus as an impulse response function, and predicted the response to various multiphasic injection profiles. Antecubital vein injections were administered via a commercially available multiphasic power injector. The TIP algorithm evaluated the predicted responses and selected the injection that best matched the desired (20-sec plateau) profile. Resulting signal intensity profiles from tailored and standard injection profiles were compared in 20 subjects (10 each). All subjects received a weight-based single-dose (0.1 mmol/kg) of gadoteridol, and abdominal aorta signal intensities were measured at 3T with a time-resolved, thick-slice, 3D spoiled-gradient-echo MR sequence with parameters approximating contrast-enhanced MR angiography. The single-phase, standard injection was injected at 1.6 mL/sec. Full-width at 80% maximum (FW80M) signal intensity was significantly longer for the tailored injection profiles (23.0 ± 2.2 vs. 9.0 ± 4.2 sec; P < 0.01). Concurrently, the profile peak signal intensity was reduced by 19% for the tailored profiles (12.0 ± 3.1 vs. 14.8 ± 2.8 times baseline; P = 0.058), nearly reaching significance. Multiphasic tailored injections from a power injector produced longer signal intensity profiles (156% increase in FW80M) with an accompanying decrease (19%) in peak signal intensity compared to a standard, single-phase injection. J. Magn. Reson. Imaging 2016. J. Magn. Reson. Imaging 2016;44:1664-1672. © 2016 International Society for Magnetic Resonance in Medicine.

  20. The change in thyroid hormone signaling by altered training intensity in male rat skeletal muscle.

    Science.gov (United States)

    Lesmana, Ronny; Iwasaki, Toshiharu; Iizuka, Yuki; Amano, Izuki; Shimokawa, Noriaki; Koibuchi, Noriyuki

    2016-08-31

    Aerobic (sub lactate threshold; sub-LT) exercise training facilitates oxidative phosphorylation and glycolysis of skeletal muscle. Thyroid hormone (TH) also facilitates such metabolic events. Thus, we studied whether TH signaling pathway is activated by treadmill training. Male adult rats received 30 min/day treadmill training with different exercise intensity for 12 days. Then plasma lactate and thyrotropin (TSH) levels were measured. By lactate levels, rats were divided into stationary control (SC, 0 m/min), sub-LT (15 m/min) and supra lactate threshold (supra-LT; 25 m/min) training groups. Immediately after the last training, the soleus muscles were dissected out to measure TH receptor (TR) mRNA and protein expressions. Other rats received intraperitoneal injection of T3, 24 h after the last training and sacrificed 6 h after the injection to measure TH target gene expression. TSH level was suppressed in both sub-LT and supra-LT groups during the exercise. TRβ1 mRNA and protein levels were increased in sub-LT group. Sensitivity to T3 was altered in several TH-target genes by training. Particularly, induction of Na(+)/K(+)-ATPase β1 expression by T3 was significantly augmented in sub-LT group. These results indicate that sub-LT training alters TH signaling at least in part by increasing TRβ1 expression. Such TH signaling alteration may contribute metabolic adaptation in skeletal muscle during physical training.

  1. A method for quantifying intervertebral disc signal intensity on T2-weighted imaging

    Energy Technology Data Exchange (ETDEWEB)

    Nagashima, Masaki [Dept. of Orthopaedic Surgery, Keio Univ. School of Medicine, Tokyo (Japan); Dept. of Orthopaedic Surgery, Kitasato Univ. Kitasato Inst. Hospital, Tokyo (Japan); Abe, Hitoshi [Dept. of Orthopaedic Surgery, Kitasato Univ. Kitasato Inst. Hospital, Tokyo (Japan)], E-mail: hit-abe@insti.kitasato-u.ac.jp; Amaya, Kenji [Graduate School of Information Science and Engineering, Tokyo Inst. of Technology, Tokyo (Japan); Matsumoto, Hideo [Inst. for Integrated Sports Medicine, Keio Univ. School of Medicine, Tokyo (Japan); Yanaihara, Hisashi [Dept. of Diagnostic Radiology, Kitasato Univ. Kitasato Inst. Hospital, Tokyo (Japan); Nishiwaki, Yuji [Dept. of Environmental and Occupational Health, Toho Univ. School of Medicine, Tokyo (Japan); Toyama, Yoshiaki; Matsumoto, Morio [Dept. of Orthopaedic Surgery, Keio Univ. School of Medicine, Tokyo (Japan)

    2012-11-15

    Background Quantification of intervertebral disc degeneration based on intensity of the nucleus pulposus in magnetic resonance imaging (MRI) often uses the mean intensity of the region of interest (ROI) within the nucleus pulposus. However, the location and size of ROI have varied in different reports, and none of the reported methods can be considered fully objective. Purpose To develop a more objective method of establishing ROIs for quantitative evaluation of signal intensity in the nucleus pulposus using T2-weighted MRI. Material and Methods A 1.5-T scanner was used to obtain T2-weighted mid-sagittal images. A total of 288 intervertebral discs from 48 patients (25 men, 23 women) were analyzed. Mean age was 47.4 years (range, 17-69 years). All discs were classified into five grades according to Pfirrmann et al. Discs in grades I and II were defined as bright discs, and discs in grades IV and V were defined as dark discs. Eight candidate methods of ROI determination were devised. The method offering the highest degree of discrimination between bright and dark discs was investigated among these eight methods. Results The method with the greatest degree of discrimination was as follows. The quadrangle formed by anterior and posterior edges of the upper and lower end plates in contact with the intervertebral disc to be measured was defined as the intervertebral area. A shape similar to the intervertebral area but with one-quarter the area was drawn. The geometrical center of the shape was matched to the center of intensity, and this shape was then used as the ROI. Satisfactory validity and reproducibility were obtained using this method. Conclusion The present method offers adequate discrimination and could be useful for longitudinal tracking of intervertebral disc degeneration with sufficient reproducibility.

  2. Spectral hole burning effects initiated by uniform signal intensities in a gain-flattened EDFA

    Institute of Scientific and Technical Information of China (English)

    A. R. Sarmani; S-J Sheih; F. R. Mahamd Adikan; M. A. Mahdi

    2011-01-01

    @@ Spectral hole burning (SHB) effects in a gain-flattened erbium-doped fiber amplifier (EDFA) are demonstrated to be significant in the presence of large signal power around the 1530-1532-nm wavelength range. These are the first effects reported in a setup employing equivalent power level distribution of 40 channels ranging from 1530 to 1561 nm. To explain this, the introduction of a new local population variable into the laser equation is required to support the original inversion ratio that is determined by the pump lasers. In the analysis section, spectroscopic parameters and high signal powers are considered to be other contributing parameters to the change in the gain characteristics. An improvement to this theoretical basis is suggested by implementing mathematical modeling to validate similarities between the gain shape of simulation to that obtained in the experiment.%Spectral hole burning (SHB) effects in a gain-fiattened erbium-doped fiber amplifier (EDFA) are demonstrated to be significant in the presence of large signal power around the 1530-1532-nm wavelength range.These are the first effects reported in a setup employing equivalent power level distribution of 40 channels ranging from 1530 to 1561 nm. To explain this, the introduction of a new local population variable into the laser equation is required to support the original inversion ratio that is determined by the pump lasers.In the analysis section, spectroscopic parameters and high signal powers are considered to be other contributing parameters to the change in the gain characteristics. An improvement to this theoretical basis is suggested by implementing mathematical modeling to validate similarities between the gain shape of simulation to that obtained in the experiment.

  3. [Short-term memory characteristics of vibration intensity tactile perception on human wrist].

    Science.gov (United States)

    Hao, Fei; Chen, Li-Juan; Lu, Wei; Song, Ai-Guo

    2014-12-25

    In this study, a recall experiment and a recognition experiment were designed to assess the human wrist's short-term memory characteristics of tactile perception on vibration intensity, by using a novel homemade vibrotactile display device based on the spatiotemporal combination vibration of multiple micro vibration motors as a test device. Based on the obtained experimental data, the short-term memory span, recognition accuracy and reaction time of vibration intensity were analyzed. From the experimental results, some important conclusions can be made: (1) The average short-term memory span of tactile perception on vibration intensity is 3 ± 1 items; (2) The greater difference between two adjacent discrete intensities of vibrotactile stimulation is defined, the better average short-term memory span human wrist gets; (3) There is an obvious difference of the average short-term memory span on vibration intensity between the male and female; (4) The mechanism of information extraction in short-term memory of vibrotactile display is to traverse the scanning process by comparison; (5) The recognition accuracy and reaction time performance of vibrotactile display compares unfavourably with that of visual and auditory. The results from this study are important for designing vibrotactile display coding scheme.

  4. Influence of signal colored hand disinfectant dispensers on hand hygiene compliance at a medical intensive care unit.

    Science.gov (United States)

    Scheithauer, Simone; Häfner, Helga; Schröder, Jörg; Nowicki, Katharina; Lemmen, Sebastian

    2014-08-01

    To assess the influence of signal colors on hand disinfectant dispenser activities, health care workers (HCWs) at a medical intensive care unit were analyzed for a total of 20 weeks with 8 weeks before and 12 weeks after exchange to signal color. No significant increase in hand rubs (HRs) per patient day (PD) was observed (about 40 HRs/PD); however, HCW-adjusted compliance showed a 6% increase with signal colored devices. Therefore, colored devices may help to improve hand hygiene compliance.

  5. Change in signal intensity on MRI of fat in the head of markedly emaciated patients

    Energy Technology Data Exchange (ETDEWEB)

    Okamoto, K.; Ishikawa, K.; Sakai, K. [Niigata Univ. (Japan). Dept. of Radiology; Ito, J.; Tokiguchi, S. [Dept. of Radiology, Niigata Univ. (Japan)

    2001-02-01

    The amount of fat in various parts of the body decreases in emaciated patients, but responds differently to disease processes. The order of disappearance of fat in various parts of the head has rarely been studied with MRI. We imaged ten patients with anorexia nervosa and one cachectic patient with a psychiatric disorder with a 1.5 T imager. Signal intensities of bone marrow of the skull, subcutaneous tissue, and orbits were assessed on T1- and T2-weighted images, and correlated with the body mass index (BMI) and haemoglobin concentration (Hb). On T1-weighted images, five patients (BMI 15.6-17.8 kg/m{sup 2}, mean 16.6 kg/m{sup 2}; Hb 10.1-14.2 g/dl, mean 13.8 g/dl) showed the normal pattern of fat. One (BMI 13.6 kg/m{sup 2}, Hb 10.4 g/dl) lost the high signal of bone marrow, but high signal of subcutaneous tissue and the orbits was preserved. High signal from bone marrow and subcutaneous tissue disappeared in three patients (BMI 11.5-13.5 kg/m{sup 2}, mean 12.5 kg/m{sup 2}; Hb 7.9-9.7 g/dl, mean 8.7 g/dl), but orbital high signal was preserved. The remaining two patients (BMI 9.3 and 13.5 kg/m{sup 2}, mean 11.5 kg/m{sup 2}; Hb 7.6 and 8.9 g/dl, mean 8.3 g/dl) showed complete loss of high signal from fat in the head. The order of disappearance of fat (bone marrow, subcutaneous fat, then orbits) correlated with both BMI and Hb. Atrophy of bone marrow was demonstrated on T2-weighted images in five patients with BMI 13.5 kg/m{sup 2} or less, and Hb 9.7 g/dl or less. (orig.)

  6. Discoscopic Findings of High Signal Intensity Zones on Magnetic Resonance Imaging of Lumbar Intervertebral Discs

    Science.gov (United States)

    Sugiura, Kosuke; Tonogai, Ichiro; Matsuura, Tetsuya; Higashino, Kosaku; Sakai, Toshinori; Suzue, Naoto; Nishisho, Toshihiko; Goda, Yuichiro; Sato, Ryosuke; Kondo, Kenji; Tezuka, Fumitake; Mineta, Kazuaki; Takeuchi, Makoto; Takahashi, Mitsuhiko; Egawa, Hiroshi; Sairyo, Koichi

    2014-01-01

    A 32-year-old man underwent radiofrequency thermal annuloplasty (TA) with percutaneous endoscopic discectomy (PED) under local anesthesia for chronic low back pain. His diagnosis was discogenic pain with a high signal intensity zone (HIZ) in the posterior corner of the L4-5 disc. Flexion pain was sporadic, and steroid injection was given twice for severe pain. After the third episode of strong pain, PED and TA were conducted. The discoscope was inserted into the posterior annulus and revealed a migrated white nucleus pulposus which was stained blue. Then, after moving the discoscope to the site of the HIZ, a migrated slightly red nucleus pulposus was found, suggesting inflammation and/or new vessels penetrating the mass. After removing the fragment, the HIZ site was ablated by TA. To our knowledge, this is the first report of the discoscopic findings of HIZ of the lumbar intervertebral disc. PMID:24963428

  7. Discoscopic Findings of High Signal Intensity Zones on Magnetic Resonance Imaging of Lumbar Intervertebral Discs

    Directory of Open Access Journals (Sweden)

    Kosuke Sugiura

    2014-01-01

    Full Text Available A 32-year-old man underwent radiofrequency thermal annuloplasty (TA with percutaneous endoscopic discectomy (PED under local anesthesia for chronic low back pain. His diagnosis was discogenic pain with a high signal intensity zone (HIZ in the posterior corner of the L4-5 disc. Flexion pain was sporadic, and steroid injection was given twice for severe pain. After the third episode of strong pain, PED and TA were conducted. The discoscope was inserted into the posterior annulus and revealed a migrated white nucleus pulposus which was stained blue. Then, after moving the discoscope to the site of the HIZ, a migrated slightly red nucleus pulposus was found, suggesting inflammation and/or new vessels penetrating the mass. After removing the fragment, the HIZ site was ablated by TA. To our knowledge, this is the first report of the discoscopic findings of HIZ of the lumbar intervertebral disc.

  8. Magnetic resonance imaging of the supraspinatus tendon: The significance of signal intensity alterations at the `critical zone`

    Energy Technology Data Exchange (ETDEWEB)

    Jones, A.O. [St Vincents Hospital, Sydney, NSW (Australia). Department of Radiology

    1998-05-01

    A pictorial essay of normal and abnormal appearances of the supraspinatus tendon is presented. An increased signal intensity within the supraspinatus tendon on short TE sequences is not necessarily abnormal. Increased signal seen within the tendon on modern magnetic resonance imaging (MRI) units is often due to a phenomenon known as the `magic angle` effect. Only when supraspinatus tendon signal intensity is greater than that of muscle on long TE (T2) sequences should it be considered to be abnormal. The physical basis for the magic angle effect is outlined and a pictorial essay demonstrating the practical implications of this effect is presented. A comparison is made to signal intensity changes seen with partial and complete tears of the supraspinatus tendon. Correlation is made with important morphologic features of partial or complete tears. Copyright (1998) Blackwell Science Pty Ltd 11 refs., 8 figs.

  9. Diagnosis of retrodiscal tissue in painful temporomandibular joint (TMJ) by fluid-attenuated inversion recovery (FLAIR) signal intensity.

    Science.gov (United States)

    Kuroda, Migiwa; Otonari-Yamamoto, Mika; Sano, Tsukasa; Fujikura, Mamiko; Wakoh, Mamoru

    2015-10-01

    The purpose of the present study is to analyze the fluid-attenuated inversion recovery (FLAIR) signal intensity of the retrodiscal tissue in a painful temporomandibular joint (TMJ), and to develop a diagnostic system based on FLAIR data. The study was based on 33 joints of 17 patients referred for MR imaging of the TMJ. Regions of interest were placed over retrodiscal tissue and gray matter (GM) on FLAIR images. Using signal intensities of GM as reference points, signal intensity ratios (SIR) of retrodiscal tissue were calculated. SIRs in painful TMJ were compared with those in painless TMJ. Wilcoxon's Rank Sum Test was used to analyze the difference in SIRs between the painful and painless groups (Pjoints than in painless joints. FLAIR sequences provide a high signal in patients having painful TMJ, and it suggests that retrodiscal tissue in painful TMJ contains elements such as protein.

  10. Effects of soil moisture and light intensity on ecophysiological characteristics of Amorpha fruticosa seedlings

    Institute of Scientific and Technical Information of China (English)

    ZHANG Xiu-ru; TAN Xiang-feng; WANG Ren-qing; XU Nan-nan; GUO Wei-hua

    2013-01-01

    We investigated the combined effects of soil moisture and light intensity on the growth,development and ecophysiological characteristics of one-year old Amorpha fruticosa seedlings.Soil moisture and light intensity influenced the ecophysiological characteristics of Amorphafruticosa seedlings.Soil moisture resulted in the decreases of growth rate,individual size,net photosynthetic rate,transpiration rate,leaf water loss rate (WLR),and biomass accumulation of plant parts,and led to increased leaf water saturation deficit (WSD).Under water stress,more photosynthetic products were allocated to root growth.With decreasing light intensity,net photosynthetic rate,transpiration rate,chla/b,water saturation deficit,water use efficiency,water loss rate and biomass accumulation declined,while Chla,Chlb,Chla+b and carotenoids (Car)increased and more photosynthetic products were allocated to stem and leaf growth.Maximum growth vigor,net photosynthetic rate and total biomass accumulation in Amorpha fruticosa seedlings was recorded at 75-80% soil water-holding capacity and 100% light density in greenhouse environments.

  11. Seed vigor, antioxidant metabolism and initial growth characteristics of red rice seedlings under different light intensities

    Directory of Open Access Journals (Sweden)

    Tiago Zanatta Aumonde

    2013-06-01

    Full Text Available This work aimed to evaluate the effect that different intensities of light have on the physiological attributes of red rice seeds and seedlings. Before and after emergence, seedlings were exposed to light levels of 35%; 65% and 100% in a greenhouse. We evaluated shoots and roots, in terms of length and dry mass, as well as leaf area and content of chlorophyll (a,b and total. In leaves and roots, we quantified the activity of superoxide dismutase (SOD, ascorbate peroxidase (APX, catalase (CAT and guaiacol peroxidase (POX. We determined the leaf area ratio (F A, leaf mass ratio (F W, specific leaf area (S A, and shoot/root ratio (P W. At higher light intensities, shoot length decreased, whereas root length, dry mass and number of tillers increased. Leaf area was greatest in seedlings exposed to a 65% light level. The F A, F W, S A and P W were lowest at a light intensity of 100%. Differences in light intensity had qualitative and quantitative effects on chlorophyll contents. The activity of SOD and CAT was higher at lower light levels, whereas the inverse was true for APX and POX activity. Extremes of light availability alter the activity of antioxidant enzymes, negatively affecting the initial growth characteristics and photosynthetic pigments of red rice seedlings.

  12. A Self-Referencing Intensity-Based Fiber Optic Sensor with Multipoint Sensing Characteristics

    Directory of Open Access Journals (Sweden)

    Sang-Jin Choi

    2014-07-01

    Full Text Available A self-referencing, intensity-based fiber optic sensor (FOS is proposed and demonstrated. The theoretical analysis for the proposed design is given, and the validity of the theoretical analysis is confirmed via experiments. We define the measurement parameter, X, and the calibration factor, β, to find the transfer function, , of the intensity-based FOS head. The self-referencing and multipoint sensing characteristics of the proposed system are validated by showing the measured  and relative error versus the optical power attenuation of the sensor head for four cases: optical source fluctuation, various remote sensing point distances, fiber Bragg gratings (FBGs with different characteristics, and multiple sensor heads with cascade and/or parallel forms. The power-budget analysis and limitations of the measurement rates are discussed, and the measurement results of fiber-reinforced plastic (FRP coupon strain using the proposed FOS are given as an actual measurement. The proposed FOS has several benefits, including a self-referencing characteristic, the flexibility to determine FBGs, and a simple structure in terms of the number of devices and measuring procedure.

  13. Risk factors, characteristics, and outcomes of candidemia in an adult intensive care unit in Turkey.

    Science.gov (United States)

    Tukenmez Tigen, Elif; Bilgin, Huseyin; Perk Gurun, Hande; Dogru, Arzu; Ozben, Beste; Cerikcioglu, Nilgun; Korten, Volkan

    2017-06-01

    Thirty-six patients with candidemia and 37 control patients were included consecutively to determine the characteristics of candidemia episodes. The patients with candidemia had higher mortality with higher Sequential Organ Failure Assessment scores and frequency of use of a central venous catheter, total parenteral nutrition, and broad-spectrum antibiotics; chronic renal failure with replacement therapy; and longer stay in an intensive care unit. Candida albicans was the predominant species followed by Candida glabrata, Candida tropicalis, and Candida parapsilosis. All isolates of C glabrata were itraconazole-resistant. Copyright © 2017 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

  14. Dynamic Characteristics of Growing Modes of Raman Instability from Intense Laser Beam Propagating Through Plasma

    Institute of Scientific and Technical Information of China (English)

    LIU Shi-Bing; CHEN Tao; CHEN Shi-Gang

    2004-01-01

    An essential dispersion relation,which can describe the dynamic properties of stimulated Raman scattering instability as a laser beam propagates through plasmas,is derived analytically.The development of growth mode,angle distribution,and temperature dependence of the instabilities are presented by solving this dispersion relation numerically.A significant dynamic characteristic has been revealed that the temperature increasing of the electron would result in redshift of scattered spectrum at high laser intensities.Furthermore,a novel modulational instability with double-peak temporal structure appears in a limited density region because of the coupling of scattered upshift and downshift waves.

  15. Characteristics of gravity signal and loading effect in China

    Directory of Open Access Journals (Sweden)

    Shuang Yi

    2015-07-01

    Full Text Available The complex geographical environment in China makes its gravity signals miscellaneous. This work gives a comprehensive representation and explanation in secular trend of gravity change in different regions, the key features of which include positive trend in inner Tibet Plateau and South China and negative trend in North China plain and high mountain Asia (HMA. We also present the patterns of amplitudes and phases of annual and semiannual change. The mechanism underlying the semiannual period is explicitly discussed. The displacement in three directions expressed in terms of geo-potential spherical coefficients and load Love numbers are given. A case study applied with these equations is presented. The results show that Global Positioning System (GPS observations can be used to compare with Gravity Recovery and Climate Experiment (GRACE derived displacement and the vertical direction has a signal-noise-ratio of about one order of magnitude larger than the horizontal directions.

  16. Influence of Signal Intensity Non-Uniformity on Brain Volumetry Using an Atlas-Based Method

    Energy Technology Data Exchange (ETDEWEB)

    Takao, Hidemasa; Kunimatsu, Akira; Mori, Harushi [University of Tokyo Hospital, Tokyo (Japan); and others

    2012-07-15

    Many studies have reported pre-processing effects for brain volumetry; however, no study has investigated whether non-parametric non-uniform intensity normalization (N3) correction processing results in reduced system dependency when using an atlas-based method. To address this shortcoming, the present study assessed whether N3 correction processing provides reduced system dependency in atlas-based volumetry. Contiguous sagittal T1-weighted images of the brain were obtained from 21 healthy participants, by using five magnetic resonance protocols. After image preprocessing using the Statistical Parametric Mapping 5 software, we measured the structural volume of the segmented images with the WFU-PickAtlas software. We applied six different bias-correction levels (Regularization 10, Regularization 0.0001, Regularization 0, Regularization 10 with N3, Regularization 0.0001 with N3, and Regularization 0 with N3) to each set of images. The structural volume change ratio (%) was defined as the change ratio (%) = (100 X[measured volume - mean volume of five magnetic resonance protocols] / mean volume of five magnetic resonance protocols) for each bias-correction level. A low change ratio was synonymous with lower system dependency. The results showed that the images with the N3 correction had a lower change ratio compared with those without the N3 correction. The present study is the first atlas-based volumetry study to show that the precision of atlas-based volumetry improves when using N3-corrected images. Therefore, correction for signal intensity non-uniformity is strongly advised for multi-scanner or multi-site imaging trials.

  17. MR imaging of compressive cervical myelopathy after surgery; High signal intensity of the spinal cord on T2 weighted images

    Energy Technology Data Exchange (ETDEWEB)

    Mimura, Fumitoshi; Fujiwara, Kazuhisa; Otake, Shoichiro (Tenri Hospital, Nara (Japan)) (and others)

    1990-06-01

    We reviewed the MR images of 32 patients with cervical myelopathy, showing lesions of high signal intensity in the spinal cord on the sagittal T2 weighted images (T2WI) after surgery: 16 with ossification of posterior longitudinal ligament (OPLL); 9 with spondylosis; 4 with disc herniation and 3 with trauma. All images were obtained on a superconducting 1.5 Tesla system. The lesions were classified into five groups, according to the shape and grade of signal intensity on the sagittal T2WI: (I) oval-shaped lesion of signal intensity less brighter than CSF with blurred margin, (II) longitudinal linear-shaped lesion of signal intensity similar to CSF, (III) spindle-shaped lesion of signal intensity similar to CSF, (IV) round-shaped lesion of signal intensity similar to CSF, and (V) mixed-types lesions which consisted of group I and II. The present study was summarized as follows: Oval-shaped lesions were seen in the cases of disc herniation and spondylosis with relatively short duration of the symptom, presumptively with relatively short duration of the symptom, presumptively indicative of edema. Most cases of OPLL and spondylosis showed linear-shaped lesions, suggesting necrosis and/or cavitations of the central gray matter. One case of spondylosis developed a spindle-shaped lesion, implicating syringomyelia. Round-shaped lesions were seen in the cases of spinal trauma, suggesting postraumatic cyst. In a case of mixed-typed lesion examined pre- and postoperatively, only an oval-shaped lesion decreased in size after surgery. (author).

  18. MORPHOLOGICAL CHARACTERISTICS AND FORAGE PRODUCTIVITY OF IRRIGATED CACTUS PEAR UNDER DIFFERENT CUTTING INTENSITIES

    Directory of Open Access Journals (Sweden)

    GUILHERME FERREIRA DA COSTA LIMA

    2016-01-01

    Full Text Available This study evaluated the effect of different cutting intensities and years of harvesting on the morphological characteristics and production of fresh (FMP and dry matter (DMP of cactus pear cv. Gigante (Opuntia ficus-indica Mill under conditions of irrigation, high planting density and fertilization, with 12 months of regrowth. The experimental was completely randomized in a factorial design (3 × 2 with 12 replicates. The treatments were three cutting intensities (preserving the mother cladode (PMC, primary cladodes (PPC, or secondary cladodes (PSC, and two years of harvesting. The soil was classified as Cambisol Haplicum and the irrigation water was classified as C4S1 (EC 5.25 dS.m-1 density of 50,000 plants ha-1. The research evaluated plant height, number of cladodes per plant (NCP, length, width, perimeter and thickness of the cladodes, cladode area (CA, cladode area index (CAI, FMP and DMP. There was no significant interaction between treatments (P > 0.05 for the variables plant height, NCP, CAI and FMP. The variables related to cladode morphology showed a significant interaction (P < 0.05. The treatment PSC resulted in a greater DMP (P < 0.05 with a mean of 27.17 Mg ha-1 yr-1, compared to PPC (18.58 Mg ha-1 yr-1 or PMC (11.78 Mg ha-1 yr-1. The treatment PSC promoted greater NCP and forage productivity at harvest and can be considered as a management practice for the sustainability of cactus pear cv. Gigante under irrigation. The more important morphological characteristics were also influenced by the lower cutting intensities.

  19. Prenatal diagnosis of fetal respiratory function: evaluation of fetal lung maturity using lung-to-liver signal intensity ratio at magnetic resonance imaging.

    Science.gov (United States)

    Oka, Yasuko; Rahman, Mosfequr; Sasakura, Chihaya; Waseda, Tomoo; Watanabe, Yukio; Fujii, Ryota; Makinoda, Satoru

    2014-12-01

    The purpose of this retrospective study is to determine the fetal lung-to-liver signal intensity ratio (LLSIR) on T2-weighted images for the prediction of neonatal respiratory outcome. One hundred ten fetuses who underwent magnetic resonance imaging (MRI) examination for various indications after 22 weeks of gestation participated in this study. LLSIR was measured as the ratio of signal intensities of the fetal lung and liver on T2-weighted images at MRI. We examined the changes of the ratio with advancing gestation and the relations between LLSIR and the presence of the severe respiratory disorder (SRD) after birth. The best cut-off value of the LLSIR to predict respiratory outcome after birth was calculated using receiver operating characteristic (ROC) curve analysis. Lung-to-liver signal intensity ratio correlated significantly with advancing gestational age (R = 0.35, p fetal LLSIR on T2-weighted images is an accurate marker to diagnose the fetal lung maturity. © 2014 The Authors. Prenatal Diagnosis published by John Wiley & Sons, Ltd.

  20. Electronic polarization-division demultiplexing based on digital signal processing in intensity-modulation direct-detection optical communication systems.

    Science.gov (United States)

    Kikuchi, Kazuro

    2014-01-27

    We propose a novel configuration of optical receivers for intensity-modulation direct-detection (IM · DD) systems, which can cope with dual-polarization (DP) optical signals electrically. Using a Stokes analyzer and a newly-developed digital signal-processing (DSP) algorithm, we can achieve polarization tracking and demultiplexing in the digital domain after direct detection. Simulation results show that the power penalty stemming from digital polarization manipulations is negligibly small.

  1. MRI investigation of normal fetal lung maturation using signal intensities on different imaging sequences.

    Science.gov (United States)

    Balassy, Csilla; Kasprian, Gregor; Brugger, Peter C; Weber, Michael; Csapo, Bence; Mittermayer, Christoph; Hörmann, Marcus; Prayer, Daniela

    2007-03-01

    To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development.

  2. MRI investigation of normal fetal lung maturation using signal intensities on different imaging sequences

    Energy Technology Data Exchange (ETDEWEB)

    Balassy, Csilla; Kasprian, Gregor; Weber, Michael; Hoermann, Marcus; Prayer, Daniela [Medical University of Vienna, Department of Radiology, Vienna (Austria); Brugger, Peter C. [Medical University of Vienna, Center of Anatomy and Cell Biology, Vienna (Austria); Csapo, Bence [Medical University of Vienna, Department of Obstetrics and Gyneocology, Vienna (Austria); Mittermayer, Christoph [Medical University of Vienna, Department of Pediatrics, Vienna (Austria)

    2007-03-15

    To purpose of this paper is to study the relation between normal lung maturation signal and changes in intensity ratios (SIR) and to determine which magnetic resonance imaging sequence provides the strongest correlation of normal lung SIs with gestational age. 126 normal singleton pregnancies (20-37 weeks) were examined with a 1.5 Tesla unit. Mean SIs for lungs, liver, and gastric fluid were assessed on six different sequences, and SIRs of lung/liver (LLSIR) and lung/gastric fluid (LGSIR) were correlated with gestational age for each sequence. To evaluate the feasibility of SIRs in the prediction of the state of the lung maturity, accuracy of the predicted SIRs (D*) was measured by calculating relative residuals (D*-D)/D for each sequence. LLSIRs showed significant changes in every sequence (p<0.05), while LGSIRs only on two sequences. Significant differences were shown for the mean of absolute residuals for both LLSIRs (p<0.001) and for LGSIRs (p=0.003). Relative residuals of LLSIRs were significantly smaller on T1-weighted sequence, whereas they were significantly higher for LGSIRs on FLAIR sequence. Fetal liver seems to be adequate reference for the investigation of lung maturation. T1-weighted sequence was the most accurate for the measurement of the lung SIs; thus, we propose to determine LLSIR on T1-weighted sequence when evaluating lung development. (orig.)

  3. Appearances of diffuse excessive high signal intensity (DEHSI) on MR imaging following preterm birth

    Energy Technology Data Exchange (ETDEWEB)

    Hart, Anthony R. [Sheffield Teaching Hospital NHS Foundation Trust, Department of Neonatology, Jessop Wing, Sheffield (United Kingdom); University of Sheffield, Academic Unit of Radiology, Royal Hallamshire Hospital, Sheffield (United Kingdom); University of Sheffield, Department of Academic Radiology, Royal Hallamshire Hospital, Sheffield (United Kingdom); Smith, Michael F. [Sheffield Teaching Hospital NHS Foundation Trust, Department of Neonatology, Jessop Wing, Sheffield (United Kingdom); Rigby, Alan S. [University of Hull, Postgraduate Medical Centre, Castle Hill Hospital, East Yorkshire (United Kingdom); Wallis, Lauren I.; Whitby, Elspeth H. [University of Sheffield, Academic Unit of Radiology, Royal Hallamshire Hospital, Sheffield (United Kingdom)

    2010-08-15

    Diffuse damage to the periventricular white matter has recently been suggested to be a cause of the cognitive deficits seen following preterm birth. It is unclear whether this form of injury can be visualised on MR imaging, but one group has described diffuse excessive high signal intensity (DEHSI) as a possible form of diffuse white matter injury. This finding is dependant on window imaging and the subjective assessment of the reviewer, but little data have been published on the degree of subjectivity on its appearance among raters. To assess the subjectivity of DEHSI on conventional and ultrafast T2-weighted MR imaging following preterm birth. An observational study of 40 preterm infants who had MR imaging of the brain around term-equivalent age, including conventional fast spin-echo (FSE) and ultrafast single-shot fast spin-echo (SSFSE) T2-weighted sequences in the axial plane. Images were anonymised and scored twice by four observers for the presence of DEHSI. Inter- and intra-observer agreement were calculated. Sixty-five percent of conventional and 100% of the ultrafast images were of diagnostic quality. DEHSI was noted in between 0% and 69.2% of conventional images and 27.5-90% of the ultrafast images. Inter- and intra-observer agreement ranged from none to moderate. The visual appearances of DEHSI on conventional FSE and ultrafast SSFSE T2-W images are highly subjective, limiting its clinical application. (orig.)

  4. The Role of Anthropogenic Influence on Biological Signal Field (BSF Characteristics of the Wolf, Canis lupus lupus (Canidae, Carnivora

    Directory of Open Access Journals (Sweden)

    Shkvyria M. G.

    2016-02-01

    Full Text Available The main goal of the current research includes studying the biological signal field (BSF characteristics of the wolf (Canis lupus lupus Linnaeus, 1758 at different values of anthropogenic load on territories with conservation (Białowieża National park (Poland and hunting status of the species (Chornobyl Exclusion Zone (Ukraine. The research in Białowieża Primeval Forest was conducted in two stages: study of the BSF characteristics of the wolf and finding correlation between data acquired from Ukraine (the first stage, and over-time study of intensity of the biological signal field (the second stage. In result of the first stage, there was no significant dependence on the characteristics of the territory and the differences between the behavior of wolves in the Białowieża Primeval Forest (conservation status of the species and the Exclusion Zone (game status. During the second stage it was determined that provided variance of the intensity between territory groups was insufficient, the degree of significance to animals of area categories varied with the stages of the pack’s life. It was found that the main factors which govern the character of wolf activity are not the level of the anthropic load and hunting pressure, but periods of the life cycle and spatial structure of groups.

  5. Epidemiology, clinical characteristics and resource implications of pandemic (H1N1) 2009 in intensive care units in Ireland.

    LENUS (Irish Health Repository)

    Nicolay, Nathalie

    2010-12-01

    To describe the incidence, clinical characteristics and outcomes of critically ill patients in Ireland with pandemic (H1N1) 2009 infection, and to provide a dynamic assessment of the burden of such cases on Irish intensive care units.

  6. Quantification of myocardial perfusion based on signal intensity of flow sensitized MRI

    Science.gov (United States)

    Abeykoon, Sumeda B.

    The quantitative assessment of perfusion is important for early recognition of a variety of heart diseases, determination of disease severity and their cure. In conventional approach of measuring cardiac perfusion by arterial spin labeling, the relative difference in the apparent T1 relaxation times in response to selective and non-selective inversion of blood entering the region of interest is related to perfusion via a two-compartment tissue model. But accurate determination of T1 in small animal hearts is difficult and prone to errors due to long scan times. The purpose of this study is to develop a fast, robust and simple method to quantitatively assess myocardial perfusion using arterial spin labeling. The proposed method is based on signal intensities (SI) of inversion recovery slice-select, non-select and steady-state images. Especially in this method data are acquired at a single inversion time and at short repetition times. This study began by investigating the accuracy of assessment of perfusion using a two compartment system. First, determination of perfusion by T1 and SI were implemented to a simple, two-compartment phantom model. Mathematical model developed for full spin exchange models (in-vivo experiments) by solving a modified Bloch equation was modified to develop mathematical models (T1 and SI) for a phantom (zero spin exchange). The phantom result at different flow rates shows remarkable evidence of accuracy of the two-compartment model and SI, T1 methods: the SI method has less propagation error and less scan time. Next, twelve healthy C57BL/6 mice were scanned for quantitative perfusion assessment and three of them were repeatedly scanned at three different time points for a reproducibility test. The myocardial perfusion of healthy mice obtained by the SI-method, 5.7+/-1.6 ml/g/min, was similar (p=0.38) to that obtained by the conventional T1 method, 5.6+/- 2.3 ml/g/min. The reproducibility of the SI method shows acceptable results: the

  7. Morphological characteristics of the interspecies hybrid between Sorghum and Sudan grass under intensive nitrogen nutrition

    Directory of Open Access Journals (Sweden)

    Ikanović Jela

    2013-01-01

    Full Text Available The object of this study was a two-year trial (2009 and 2010 regarding variability of morphological characteristics of species belonging to Sorghum genus, more specifically interspecies hybrid between sorghum and Sudan grass Siloking as affected by different applications of nitrogen. The following morphological characteristics were analysed: plant height, number of leaves, leaf ratio, stem ratio, and number of shoots. Samples were taken from the first cut when the effect of the applied nitrogen doses was the strongest. The results showed that increasing nitrogen quantities significantly affected the tested morphological characteristics, especially the intensity of tillering (increased number of secondary stems, number of the formed leaves, and ratio of leaf weight in the total above-ground biomass. The effect of applied nitrogen depended on the weather conditions, i.e. distribution of precipitation, so that plants reached maximum height when 105 kg N ha-1 was applied in the dry year and 180 kg N ha-1 in the wet year. [Projekat Ministarstva nauke Republike Srbije, br. TR 31078 i br. TR 31022

  8. Analysis of Optical Signal Transmission Characteristics in AWG Multi/Demultiplexer with Electromagnetic Field Theory

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    Based on the electromagnetic field theory, the optical signal transmission characteristics in input/output waveguides, slab waveguides and arrayed waveguides of the arrayed waveguide grating (AWG) multi/demultiplexer are analyzed. The relationship between the physical parameters such as geometry sizes and relative refractive index in AWG multi/demultiplexer and the optical signal transmission characteristics are discussed. This theoretical study can be used for optimizing the design and improving the performance of the AWG multi/demultiplexer.

  9. A paradoxical signal intensity increase in fatty livers using opposed-phase gradient echo imaging with fat-suppression pulses

    Energy Technology Data Exchange (ETDEWEB)

    Mulkern, Robert V.; Voss, Stephan [Harvard Medical School, Department of Radiology, Children' s Hospital Boston, Boston, MA (United States); Loeb Salsberg, Sandra; Krauel, Marta Ramon; Ludwig, David S. [Harvard Medical School, Department of Medicine, Children' s Hospital Boston, Boston, MA (United States)

    2008-10-15

    With the increase in obese and overweight children, nonalcoholic fatty liver disease has become more prevalent in the pediatric population. Appreciating subtleties of magnetic resonance (MR) signal intensity behavior from fatty livers under different imaging conditions thus becomes important to pediatric radiologists. We report an initially confusing signal behavior - increased signal from fatty livers when fat-suppression pulses are applied in an opposed-phase gradient echo imaging sequence - and seek to explain the physical mechanisms for this paradoxical signal intensity behavior. Abdominal MR imaging at 3 T with a 3-D volumetric interpolated breath-hold (VIBE) sequence in the opposed-phase condition (TR/TE 3.3/1.3 ms) was performed in five obese boys (14{+-}2 years of age, body mass index >95th percentile for age and sex) with spectroscopically confirmed fatty livers. Two VIBE acquisitions were performed, one with and one without the use of chemical shift selective (CHESS) pulse fat suppression. The ratios of fat-suppressed over non-fat-suppressed signal intensities were assessed in regions-of-interest (ROIs) in five tissues: subcutaneous fat, liver, vertebral marrow, muscle and spleen. The boys had spectroscopically estimated hepatic fat levels between 17% and 48%. CHESS pulse fat suppression decreased subcutaneous fat signals dramatically, by more than 85% within regions of optimal fat suppression. Fatty liver signals, in contrast, were elevated by an average of 87% with CHESS pulse fat suppression. Vertebral marrow signal was also significantly elevated with CHESS pulse fat suppression, while spleen and muscle signals demonstrated only small signal increases on the order of 10%. We demonstrated that CHESS pulse fat suppression actually increases the signal intensity from fatty livers in opposed-phase gradient echo imaging conditions. The increase can be attributed to suppression of one partner of the opposed-phase pair that normally contributes to the

  10. Dynamic stress intensity factor KⅢ and dynamic crack propagation characteristics of anisotropic materials

    Institute of Scientific and Technical Information of China (English)

    GAO Xin; WANG Han-gong; KANG Xing-wu

    2008-01-01

    Based on the mechanics of anisotropic materials,the dynamic propagation problem of a mode Ⅲ crack in an infinite anisotropic body is investigated.Stress,strain and displacement around the crack tip are expressed as an analytical complex function,which can be represented in power series.Constant coefficients of series are determined by boundary conditions.Expressions of dynamic stress intensity factors for a mode Ⅲ crack are obtained.Components of dynamic stress,dynamic strain and dynamic displacement around the crack tip are derived.Crack propagation characteristics are represented by the mechanical properties of the anisotropic materials,i.e.,crack propagation velocity M and the parameter α.The faster the crack velocity is,the greater the maximums of stress components and dynamic displacement components around the crack tip are.In particular,the parameter α affects stress and dynamic displacement around the crack tip.

  11. Determination of x-ray spectra including characteristic line intensities from attenuation data

    Energy Technology Data Exchange (ETDEWEB)

    Rubio, M.; Mainardi, R.T. (Universidad Nacional de Cordoba (Argentina). Facultad de Matematica, Astronomia y Fisica)

    1984-11-01

    The Laplace pair transform method for the determination of X-ray spectral shapes has been modified by adding characteristic lines, assuming that the energy of each line is known. Their intensities are parameters to be determined by this extended method. A numerical simulation procedure was used to obtain attenuation data and from this all relevant parameters were determined: four parameters were allocated to the continuum plus one for each line considered. Measured X-ray spectral distributions taken from the literature were used both to generate attenuation data and also to verify the spectrum reconstruction procedure. Percentage differences from both sets of data are less than 8% and they were used to check the goodness of fit of the reconstructed spectra.

  12. Amplification of the Signal Intensity of Fluorescence-Based Fiber-Optic Biosensors Using a Fabry-Perot Resonator Structure

    Directory of Open Access Journals (Sweden)

    Meng-Chang Hsieh

    2015-02-01

    Full Text Available Fluorescent biosensors have been widely used in biomedical applications. To amplify the intensity of fluorescence signals, this study developed a novel structure for an evanescent wave fiber-optic biosensor by using a Fabry-Perot resonator structure. An excitation light was coupled into the optical fiber through a laser-drilled hole on the proximal end of the resonator. After entering the resonator, the excitation light was reflected back and forth inside the resonator, thereby amplifying the intensity of the light in the fiber. Subsequently, the light was used to excite the fluorescent molecules in the reactive region of the sensor. The experimental results showed that the biosensor signal was amplified eight-fold when the resonator reflector was formed using a 92% reflective coating. Furthermore, in a simulation, the biosensor signal could be amplified 20-fold by using a 99% reflector.

  13. The potential characteristics analysis of probing signal with the quadratic frequency modulation

    Directory of Open Access Journals (Sweden)

    O. D. Mrachkovsky

    2012-12-01

    Full Text Available Introduction: Complex signals with the button ambiguity function can provide the distance and speed of target independent estimation. The signal with the symmetrical linear frequency modulation has this property in the class of signal with frequency modulation. Problem statement: To show that in the class of signals frequency-shift is signal with button ambiguity function. Such signal is a signal with the quadratic frequency intra-modulation. The potential characteristics research of signal with the quadratic frequency intra-modulation: The signal with quadratic frequency modulation and its properties are considered, analytic form of signal and its spectrum are shown, figures of amplitude spectra of signal are drawn, and figures of ambiguity diagram, cross-correlation functions and response ambiguity function in strong and weak fields are shown. The comparison of the signal with the quadratic frequency intra-modulation and the signal with the symmetrical linear frequency modulation are shown. The result of research is that the ambiguity function form of a signal with the quadratic frequency intra-modulation comes nearer to button in the strong correlation field and it has X – for min the weak correlation field. The autocorrelation function of the signal with the quadratic frequency intra-modulation has some constant level which decreases with signal base increasing. It is revealed that autocorrelation function of the signal has no side lobes. It improves resolution capability of a weak signal against the strong signal. The pedestal level of the autocorrelation function of this signal is a little lower than pedestal level of the autocorrelation function of the signal with the symmetrical linear frequency modulation. Properties of section of cross-correlation function to two peaks and effect of these properties are considered. Signals with the quadratic frequency intra-modulation are expedient for using in the sonar of submarines, because in

  14. High signal intensity of intervertebral calcified disks on T1-weighted MR images resulting from fat content

    Energy Technology Data Exchange (ETDEWEB)

    Malghem, Jacques; Lecouvet, Frederic E.; Berg, Bruno C. Vande; Duprez, Thierry; Cosnard, Guy; Maldague, Baudouin E. [Universite Catholique de Louvain, Cliniques Universitaires St. Luc, Brussels (Belgium); Francois, Robert [Belgian Military Hospital, Department of Rheumatology, Brussels (Belgium)

    2005-02-01

    To explain a cause of high signal intensity on T1-weighted MR images in calcified intervertebral disks associated with spinal fusion. Magnetic resonance and radiological examinations of 13 patients were reviewed, presenting one or several intervertebral disks showing a high signal intensity on T1-weighted MR images, associated both with the presence of calcifications in the disks and with peripheral fusion of the corresponding spinal segments. Fusion was due to ligament ossifications (n=8), ankylosing spondylitis (n=4), or posterior arthrodesis (n=1). Imaging files included X-rays and T1-weighted MR images in all cases, T2-weighted MR images in 12 cases, MR images with fat signal suppression in 7 cases, and a CT scan in 1 case. Histological study of a calcified disk from an anatomical specimen of an ankylosed lumbar spine resulting from ankylosing spondylitis was examined. The signal intensity of the disks was similar to that of the bone marrow or of perivertebral fat both on T1-weighted MR images and on all sequences, including those with fat signal suppression. In one of these disks, a strongly negative absorption coefficient was focally measured by CT scan, suggesting a fatty content. The histological examination of the ankylosed calcified disk revealed the presence of well-differentiated bone tissue and fatty marrow within the disk. The high signal intensity of some calcified intervertebral disks on T1-weighted MR images can result from the presence of fatty marrow, probably related to a disk ossification process in ankylosed spines. (orig.)

  15. Changes in heat waves characteristics over Extremadura (SW Spain): duration, intensity and frequency

    Science.gov (United States)

    Acero, Javier; Parey, Sylvie; Fernández-Fernández, María Isabel; Carrasco, Víctor Manuel; Agustín García, José

    2016-04-01

    Heat waves (HW) are increasing and its consequences are important not only for the effects over the population but also for the agriculture and biodiversity. That's why trends in heat wave events over Extremadura, a Region located in the southwest of Spain and characterized by irrigated land with crops like corn or tomatoes growing in summers, has been studied. Heat waves are defined as days occurring above the 95th percentile of the summer (June-August) maximum temperature time series. Another event named as Warm Event (WE) has been studied and defined as exceedance over the 75th percentile. For this purpose, a set of 13 regularly distributed daily maximum temperature time series was selected from a larger database for the Region of Extremadura for the common period 1965-2014. A stochastic seasonal functional heteroscedastic auto-regressive model developed to simulate daily (minimum, maximum, or mean) temperature time series coherent with observed time series (Parey et al., 2014, Dacunha-Castelle et al., 2015) has been used. This stochastic temperature generator is used to reproduce 1000 time series equivalent to the observed ones in order to investigate the significance of the changes in HW characteristics: duration, intensity and frequency; using different sub-periods length for the observed period. The results show that the changes in HW frequencies of the last 10-year sub-period comparing to the first are significant for 7 of the 13 observatories but the changes in HW durations and intensities are not significant. But when considering the lower threshold (75th percentile) to study changes in WE characteristics, frequency shows significant changes in 8 observatories, duration for 4 observatories and intensity for 2. Then, the parameters of the WE are increasing higher than the corresponding to the HW events. References: Parey, S., T. T. H. Hoang, and D. Dacunha-Castelle (2014), Validation of a stochastic temperature generator focusing on extremes, and an

  16. Time-Frequency Characteristics of Tsunami Magnetic Signals from Four Pacific Ocean Events

    Science.gov (United States)

    Schnepf, N. R.; Manoj, C.; An, C.; Sugioka, H.; Toh, H.

    2016-12-01

    The recent deployment of highly sensitive seafloor magnetometers coinciding with the deep solar minimum has provided excellent opportunities for observing tsunami electromagnetic signals. These fluctuating signals (periods ranging from 10-20 min) are generally found to be within ± ˜1 nT and coincide with the arrival of the tsunami waves. Previous studies focused on tsunami electromagnetic characteristics, as well as modeling the signal for individual events. This study instead aims to provide the time-frequency characteristics for a range of tsunami signals and a method to separate the data's noise using additional data from a remote observatory. We focus on four Pacific Ocean events of varying tsunami signal amplitude: (1) the 2011 Tohoku, Japan event (M9.0), (2) the 2010 Chile event (M8.8), (3) the 2009 Samoa event (M8.0) and, (4) the 2007 Kuril Islands event (M8.1). We find possible tsunami signals in high-pass filtered data and successfully isolate the signals from noise using a cross-wavelet analysis. The cross-wavelet analysis reveals that the longer period signals precede the stronger, shorter period signals. Our results are very encouraging for using tsunami magnetic signals in warning systems.

  17. A New Feature Extraction Algorithm Based on Entropy Cloud Characteristics of Communication Signals

    Directory of Open Access Journals (Sweden)

    Jingchao Li

    2015-01-01

    Full Text Available Identifying communication signals under low SNR environment has become more difficult due to the increasingly complex communication environment. Most relevant literatures revolve around signal recognition under stable SNR, but not applicable under time-varying SNR environment. To solve this problem, we propose a new feature extraction method based on entropy cloud characteristics of communication modulation signals. The proposed algorithm extracts the Shannon entropy and index entropy characteristics of the signals first and then effectively combines the entropy theory and cloud model theory together. Compared with traditional feature extraction methods, instability distribution characteristics of the signals’ entropy characteristics can be further extracted from cloud model’s digital characteristics under low SNR environment by the proposed algorithm, which improves the signals’ recognition effects significantly. The results from the numerical simulations show that entropy cloud feature extraction algorithm can achieve better signal recognition effects, and even when the SNR is −11 dB, the signal recognition rate can still reach 100%.

  18. Time-frequency characteristics of blasting vibration signals measured in milliseconds

    Institute of Scientific and Technical Information of China (English)

    Zhao Mingsheng; Zhang Jianhua; Yi Changping

    2011-01-01

    In order to study the time-frequency characteristics of blasting vibration signals,measured in milliseconds,we carried out site blasting vibration tests at an open pit of the Jinduicheng Mine.Based on recorded field data and applying a combination of RSPWVD and wavelet,.we analyzed the time-frequency characteristics of recorded field data.summarized the time-frequency characteristics of blasting vibration signals in different frequency bands and present detailed information of blasting vibration signals in milliseconds of high time-frequency resolutions.Because RSPWVD can be seen as of definite physical significance to signal energy distribution in time and frequency domains,we studied the energy distribution of blasting vibration signals for various milliseconds intervals from a perspective of energy distribution.The results indicate that the effect of milliseconds intervals on time-frequency characteristics of blasting vibration signals is significant:the length of delay time directly affects the energy distribution of blasting vibration signals as well as the duration of energy in frequency bands.

  19. STATISTICAL CHARACTERISTICS INVESTIGATION OF PREDICTION ERRORS FOR INTERFEROMETRIC SIGNAL IN THE ALGORITHM OF NONLINEAR KALMAN FILTERING

    Directory of Open Access Journals (Sweden)

    E. L. Dmitrieva

    2016-05-01

    Full Text Available Basic peculiarities of nonlinear Kalman filtering algorithm applied to processing of interferometric signals are considered. Analytical estimates determining statistical characteristics of signal values prediction errors were obtained and analysis of errors histograms taking into account variations of different parameters of interferometric signal was carried out. Modeling of the signal prediction procedure with known fixed parameters and variable parameters of signal in the algorithm of nonlinear Kalman filtering was performed. Numerical estimates of prediction errors for interferometric signal values were obtained by formation and analysis of the errors histograms under the influence of additive noise and random variations of amplitude and frequency of interferometric signal. Nonlinear Kalman filter is shown to provide processing of signals with randomly variable parameters, however, it does not take into account directly the linearization error of harmonic function representing interferometric signal that is a filtering error source. The main drawback of the linear prediction consists in non-Gaussian statistics of prediction errors including cases of random deviations of signal amplitude and/or frequency. When implementing stochastic filtering of interferometric signals, it is reasonable to use prediction procedures based on local statistics of a signal and its parameters taken into account.

  20. New characteristics of intensity assessment of Sichuan Lushan "4.20" M s7.0 earthquake

    Science.gov (United States)

    Sun, Baitao; Yan, Peilei; Chen, Xiangzhao

    2014-08-01

    The post-earthquake rapid accurate assessment of macro influence of seismic ground motion is of significance for earthquake emergency relief, post-earthquake reconstruction and scientific research. The seismic intensity distribution map released by the Lushan earthquake field team of the China Earthquake Administration (CEA) five days after the strong earthquake ( M7.0) occurred in Lushan County of Sichuan Ya'an City at 8:02 on April 20, 2013 provides a scientific basis for emergency relief, economic loss assessment and post-earthquake reconstruction. In this paper, the means for blind estimation of macroscopic intensity, field estimation of macro intensity, and review of intensity, as well as corresponding problems are discussed in detail, and the intensity distribution characteristics of the Lushan "4.20" M7.0 earthquake and its influential factors are analyzed, providing a reference for future seismic intensity assessments.

  1. Saturation Effect on Pump-to-Signal Intensity Modulation Transfer in Single-Pump Phase-Insensitive Fibre Optic Parametric Amplifiers

    DEFF Research Database (Denmark)

    Cristofori, Valentina; Lali-Dastjerdi, Zohreh; Lund-Hansen, Toke

    2011-01-01

    A numerical and experimental characterization of how signal gain saturation affects the transfer of the intensity modulation of the pump to the signal in single-pump phaseinsensitive fibre optic parametric amplifiers is presented.......A numerical and experimental characterization of how signal gain saturation affects the transfer of the intensity modulation of the pump to the signal in single-pump phaseinsensitive fibre optic parametric amplifiers is presented....

  2. Numerical modeling of DPSK pressure signals and their transmission characteristics in mud channels

    Institute of Scientific and Technical Information of China (English)

    Shen Yue; Su Yinao; Li Gensheng; Li Lin; Tian Shouceng

    2009-01-01

    A numerical model and transmission characteristic analysis of DPSK (differential phase shift keying) pressure signals in mud channels is introduced. With the control logic analysis of the rotary valve mud telemetry, a logical control signal is built from a Gate function sequence according to the binary symbols of transmitted data and a phase-shift function is obtained by integrating the logical control signal. A mathematical model of the DPSK pressure signal is built based on principles of communications by modulating carrier phase with the phase-shift function and a numerical simulation of the pressure wave is implemented with the mathematical model by MATLAB programming. Considering drillpipe pressure and drilling fluid temperature profile along drillpipes, the drillpipe of a vertical well is divided into a number of sections. With water-based drilling fluids, the impacts of travel distance, carrier frequency, drillpipe size, and drilling fluids on the signal transmission were studied by signal transmission characteristic analysis for all the sections. Numerical calculation results indicate that the influences of the viscosity of drilling fluids and volume fraction of gas in drilling fluids on the DPSK signal transmission are more notable than the others and the signal will distort in waveform with differential attenuations of the signal frequent component.

  3. Tensiomyographic Characteristics of Rectus Femoris after a Single Bout of Intense Exercise

    Directory of Open Access Journals (Sweden)

    Luis C Paez

    2011-01-01

    Full Text Available Problem statement: It is not well known how local fatigue can impair the contractile properties of skeletal muscle, so the aim of this study was to determine the Tensiomyographic (TMG characteristics of Rectus Femoris (RF after a single bout of intense exercise. Approach: Twelve healthy male volunteers (mean±SEM; age, 24.16±0.62 years, height 172.02±1.21 cm, body mass 71.84±2.19 kg, BMI 24.42±0.70 kg m- were recruited. Results: In session 1, a graded exercise test on cycle ergometer was performed in order to determine subject’s maximal oxygen uptake (VO2max and power at this key point (pVO2max. In a second testing session, TMG rest values were assessed and then all subjects carried out 2 min of cycling at pVO2max after which TMG analysis was applied again. The results showed subject’s VO2max values of 53.44±2.67 ml kg-1 min-1 reaching a mean pVO2max of 270.83±8.61 W. Maximal radial displacement (Dm and time from the onset of electrical stimulus to 10% of Dm (Td were significantly lower at post-test (from 7.577.57±0.92-4.37±0.67 mm; p = 0.01, for Dm and from 25.25±0.57-22.44±0.89 ms; p≤0.05, for Td. Conclusion/Recommendations: It can be concluded that a brief and intense exercise consisting in 2 min of cycling at PVO2max provokes a reduction in contractile properties of RF considering TMG parameters such as Dm and Td. More studies are needed to clarify the role of muscle fatigue on temporal TMG parameters.

  4. Evaluation of low signal intensity in the posterior disc attachment of the temporomandibular joint on T1-weighted magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Chiba, Masatoshi; Echigo, Seishi [Tohoku Univ., Sendai (Japan). School of Dentistry; Kumagai, Masahiro; Takahashi, Tetsu; Nagai, Hirokazu; Kochi, Shoko

    1996-04-01

    The posterior disc attachment (PA) of the temporomandibular joint (TMJ) has relatively high signal intensity on T1-weighted or proton density-weighted magnetic resonance imaging (MRI). Sometimes, however, low signal intensity of the PA is observed in patients with chronic disc displacement. On the basis of previous histopathological studies, the areas of low signal intensity in the PA may be consistent with pseudodisc formation associated with fibrous metaplasia of the PA. The purpose of this study was to evaluate the relations between MR signal intensity of the PA and MRI findings, including the degree of disc displacement, disc reduction, disc shape, bone change, and condylar translation, as well as clinical findings, including the duration of symptoms, joint pain, and range of motion. The study was based on MRI of 216 TMJ in 184 patients with anterior disc displacement. The sagittal closed-mouth T1-weighted SE images were used to determine the presence or absence of low signal intensity in the PA. Low signal intensity in the PA was seen in 33 joints in 32 patients (15.3%). The incidence of low signal intensity was significantly higher in males (27.8%) than in females (12.8%). No statistical difference was found between anterior disc displacement with reduction (10.5%), anterior disc displacement without reduction (21.5%), and anterior disc displacement without reduction with osteoarthrosis (14.3%). Low signal intensity in the PA was seen only in moderate or severe disc displacement. Low signal intensity in the PA was not associated with specific clinical or MRI findings except for the degree of disc displacement. In conclusion, low signal intensity in the PA is directly correlated with disc displacement, and there was no apparent correlation with clinical findings. Low signal intensity of the PA is not necessarily related to adaptation of the joint in disc displacement. (author).

  5. Orientation-dependent changes in MR signal intensity of articular cartilage: a manifestation of the ``magic angle`` effect

    Energy Technology Data Exchange (ETDEWEB)

    Wacker, F.K.; Bolze, X.; Felsenberg, D.; Wolf, K.J. [Department of Radiology, Benjamin Franklin University Hospital, Free University Berlin, D-12200 Berlin (Germany)

    1998-06-01

    Objective: To study magnetic resonance (MR) imaging pattern of normal hyaline articular cartilage in the knee joint with regard to the contribution of the ``magic angle`` effect to the MR signal. Design. Thirty-two healthy volunteers were imaged in a standard supine position in a 1.5-T unit using spin echo and gradient echo sequences. Nine volunteers were reimaged with the knee flexed. The signal behavior of the hyaline cartilage of the femoral condyles was evaluated qualitatively and quantitatively. The extended and flexed positions of the nine volunteers were compared. Results. A superficial and a deep hyperintense layer and a hypointense middle cartilage layer were observed. Segments of increased signal intensity were visible along the condyles; a magic angle effect on signal intensity was evident in the hypointense middle layer with both gradient echo and spin echo images. Conclusion. The MR signal behavior of hyaline cartilage is influenced by the alignment of the collagen fibers within the cartilage in relation to the magnetic field. Failure to recognize this effect may lead to inaccurate diagnosis. (orig.) With 4 figs., 17 refs.

  6. Changes in signal intensity of cerebral hematoma in magnetic resonance. Claves en la semiologia del hematoma cerebral en resonancia magnetica

    Energy Technology Data Exchange (ETDEWEB)

    Galant, J.; Poyatos, C.; Marti-Bonmarti, L.; Martinez, J.; Ferrer, D.; Dualde, D.; Talens, A. (Universidad de Valencia (Spain). Facultad de Ciencias Quimicas)

    1992-01-01

    Magnetic resonance is highly sensitive for the detection of intraparenchymatous hemorrhage. The evolution of hematoma over time translates into changes in signal intensity. This means that we can determine when the hematoma presented and, in addition. follow its course. On the other hand, many intracranial processes developing association with hemorrhage, the recognition of which is, in some cases, of importance. We have studied 60 cerebral hematomas and have described the changes that will take place in their signal and the reasons for them. (author)

  7. Atmospheric velocity spectral width measurements using the statistical distribution of pulsed CO2 lidar return signal intensities

    Science.gov (United States)

    Ancellet, Gerard M.; Menzies, Robert T.; Grant, William B.

    1989-01-01

    A pulsed CO2 lidar with coherent detection has been used to measure the correlation time of backscatter from an ensemble of atmospheric aerosol particles which are illuminated by the pulsed radiation. The correlation time of the backscatter of the return signal, which is directly related to the velocity spectral width, can be used to study the velocity structure constant of atmospheric turbulence and wind shear. Various techniques for correlation time measurement are discussed, and several measurement results are presented for the technique using the information contained in the statistical distribution of a set of lidar return signal intensities.

  8. Measurement of Frequency Shift Characteristics Based on LiNbO3 Waveguide Electro-Optic Intensity Modulator

    Institute of Scientific and Technical Information of China (English)

    Zhou Meng; Hui-Juan Zhou; Yi Liao; Qiong Yao

    2008-01-01

    High-speed and wide-band LiNbO3 waveguide electro-optic intensity modulator has drawn great attention in the field of optical fiber communi-cation and sensor. This paper reports the research results on the measurement of frequency shift character-istics of Mach-Zehnder electro-optic intensity modulator. Two measurement methods of frequency shift character-istics for high and low frequency modulations are studied in theory and experiment and demonstrate different results. The realization of a multi-wavelength optical source based on Mach-Zehnder electro-optic intensity modulator has been introduced. The technique to reach the maximum intensity for interesting shift frequency, particularly for heterodyne detection of Brillouin distributed optical fiber sensing, has been given.

  9. Animal performance and meat characteristics in steers reared in intensive conditions fed with different vegetable oils.

    Science.gov (United States)

    Castro, T; Cabezas, A; De la Fuente, J; Isabel, B; Manso, T; Jimeno, V

    2016-03-01

    Enhancing the quality of beef meat is an important goal in terms of improving both the nutritional value for the consumer and the commercial value for producers. The aim of this work was to study the effects of different vegetable oil supplements on growth performance, carcass quality and meat quality in beef steers reared under intensive conditions. A total of 240 Blonde D' Aquitaine steers (average BW=293.7±38.88 kg) were grouped into 24 batches (10 steers/batch) and were randomly assigned to one of the three dietary treatments (eight batches per treatment), each supplemented with either 4% hydrogenated palm oil (PALM) or fatty acids (FAs) from olive oil (OLI) or soybean oil (SOY). No differences in growth performance or carcass quality were observed. For the meat quality analysis, a steer was randomly selected from each batch and the 6th rib on the left half of the carcass was dissected. PALM meat had the highest percentage of 16:0 (P<0.05) and the lowest n-6/n-3 polyunsaturated fatty acids (PUFA) ratio (P<0.05), OLI had the highest content of t11-18:1 (P<0.01) and c9,t11-18:2 (P<0.05) and SOY showed the lowest value of monounsaturated fatty acids (MUFA) (P<0.001), the highest percentage of PUFA (P<0.01) and a lower index of atherogenicity (P=0.07) than PALM. No significant differences in the sensory characteristics of the meat were noted. However, the results of the principal component analysis of meat characteristics enabled meat from those steers that consumed fatty acids from olive oil to be differentiated from that of steers that consumed soybean oil.

  10. Characteristics of fMRI BOLD signal and its neurophysiological mechanism

    Institute of Scientific and Technical Information of China (English)

    Zhao Xiaohu; Wu Yigen; Guo Shengli

    2007-01-01

    The functional magnetic resonance imaging (fMRI) based on blood oxygen level dependent (BOLD) contrast has emerged as one of the most potent noninvasive tools for mapping brain function and has been widely used to explore physiological, pathological changes and mental activity in the brain. Exploring the nature and property of BOLD signal has recently attracted more attentions. Despite that great progress has been made in investigation of the characteristics and neurophysiological basis, the exact nature of BOLD signal remains unclear. In this paper we discuss the characteristics of BOLD signals, the nonlinear BOLD response to external stimuli and the relation between BOLD signals and neural electrophysiological recordings. Furthermore, we develop our new opinions regarding nonlinear BOLD response and make some perspectives on future study.

  11. Characteristics of organizational culture and climate in knowledge-intensive organisations

    Directory of Open Access Journals (Sweden)

    Cristina Leovaridis

    2016-04-01

    Full Text Available The article focuses on organizational culture and climate in knowledge-intensive organizations, aiming to identify the specific values and features of climate for each sector.The sample of organizations included organizations from five sectors: higher education, banking and financial, research and development, IT and marketing-advertising. The qualitative design of research included near 80 in-depth interviews with employees and managers. The results showed that climate was based on various characteristics: human relations and friendship in small marketing-advertising agencies and IT companies, competition in large advertising companies. In the research development sector, the climate was based on achieving goals in the private area of the sector ( in higher education as well, while in the public areat of the sector it was based on freedom and creativity. The climate in the banking sector was very different, being based on discipline and obeying rules. From the point of view of the organizational culture, all the interviewed employees of the advertising, IT and banking sector experienced, inside the company, the presence of certain forms of organizational culture. Only half of the interviewees from the higher education sector admit to the presence of an organizational culture in their institution while in the public funded research-development sector, employees reportedly did not experience visible manifestations of any type of organizational culture.S

  12. Patients with hematological disorders requiring admission to medical intensive care unit: Characteristics, survival and prognostic factors

    Directory of Open Access Journals (Sweden)

    Subhash H

    2003-01-01

    Full Text Available Background: This retrospective chart review assessed the characteristics and outcome of patients with hematological disorders who required admission to medical intensive care unit over a 4 year period (January 1998 to December 2001. Results: There were a total of 104 patients, 67 (64% male, 37 (36% female subjects, with a mean age of 36.3 ± 15.3 years (range 10 to 65 years. The mean duration from hospital admission to ICU transfer was 11 days. Sixty-nine (66% had malignant and 35 (34% had non-malignant conditions. Respiratory distress was the commonest reason for ICU admission 58 (56%. The other indications were hemodynamic instability 38 (36%, low sensorium 22 (21%, following cardio-pulmonary arrest 12 (11.5% and generalized tonic-clonic seizures 5 (5%. Forty-three (42% patients had absolute neutophil count (ANC less than 500, 48 (47.5% had platelet count < 20000. The mean duration of ICU stay was 4 days (range < 24 hours to 28 days. Sixty-nine (66% patients required mechanical ventilation, 61 (59% required hemodynamic support. Pneumonia or sepsis was diagnosed in 71 (68%. Twenty-five (24% survived ICU stay and 20 (19% survived to hospital discharge. ICU admission following cardio-pulmonary arrest, advanced malignancy, requirement of mechanical ventilation, vasopressor support, ANC count < 500 and platelet count < 20000 were the predictors of adverse outcome. Associated organ dysfunction further increases the mortality.

  13. INTENSITY INDEX OF SOUTH CHINA SEA MONSOON AND ITS VARIATION CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    吴尚森; 梁建茵

    2002-01-01

    According to the basic characteristics of the activities of summer monsoon in the South China Sea,Standardized index,Is,has been designed that integrates a dynamic factor(southwesterly component) and a thermodynamic factor(OLR) for the indication of summer monsoon in the South China Sea,With the index determined for individual months of June,July and August and the entire summertime from 1975 to 1999,specific months and years are indicated that are either strong or weak in monsoon intensity,The variation is studied for the patterns and Is's relationship is revealed with the onset of summer monsoon and the precipitation in Guang-dong province and China.The results show that there are quasi-10 and quasi-3-4 year cycles in the interannual variation of the monsooon over the past 25 years.When it has an early(late)onset,the summer monsoon is usually strong (weak),In the strong(weak)monsoon,years,precipitation tends to be more(less)in the first raining season of the year but normal or less(normal)in the second,in the province,but it would be more(less) in northeastern China and most parts of the northern china and south of the lower reaches of the Changjiang River and less(more)in the middle and lower reaches of the river,western part of northern China and western China.

  14. INTENSITY INDEX OF SOUTH CHINA SEA MONSOON AND ITS VARIATION CHARACTERISTICS

    Institute of Scientific and Technical Information of China (English)

    吴尚森; 梁建茵

    2002-01-01

    According to the basic characteristics of the activities of summer monsoon in the South China Sea,a standardized index,, has been designed that integrates a dynamic factor (southwesterly component) and a thermodynamic factor (OLR) for the indication of summer monsoon in the South China Sea.With the index determined for individual months of June,July and August and the entire summertime from 1975 to 1999,specific months and years are indicated that are either strong or weak in monsoon intensity.The variation is studied for the patterns and 's relationship is revealed with the onset of summer monsoon and the precipitation in Guangdong province and China.The results show that there are quasi-10 and quasi-3-4 year cycles in the interannual variation of the monsoon over the past 25 years.When it has an early (late) onset,the summer monsoon is usually strong (weak).In the strong (weak) monsoon years,precipitation tends to be more (less) in the first raining season of the year but normal or less (normal) in the second,in the province,but it would be more (less) in northeastern China and most parts of the northern China and south of the lower reaches of the Changjiang River and less (more) in the middle and lower reaches of the river,western part of northern China and western China.

  15. Small signal gain and saturation intensity of a Yb:Silica fiber MOPA system

    Science.gov (United States)

    Parvin, Parviz; Ilchi-Ghazaani, Maryam; Bananej, Alireza; Lali-Dastjerdi, Zohreh

    2009-10-01

    In this work, the small signal gain ( γ0) and signal saturation power ( Psat) of a continuous wave (CW) single-frequency ytterbium-doped (YD) double-clad (DC) fiber master oscillator power amplifier (MOPA) array has been determined in the optimum length. At first, we have obtained output versus input signal powers in the amplifier, using the coupled steady-state rate equations for the various end diode pumping such as co/counter propagation and bidirectional modes. On the other hand, the steady-state amplification relation was employed at a presumed γ0 and Psat as initial guess, to generate output signals. Then, using the least square method (LSM), those input/output signal powers were fitted by the best regression curve obtained from the amplification relation to determine the converged γ0 and Psat values. The analytical formulae for γ0 and Psat were derived using the rate equations as well.

  16. Intensity of Oestrus Signalling Is the Most Relevant Indicator for Animal Well-Being in High-Producing Dairy Cows

    OpenAIRE

    2011-01-01

    Full signalling of oestrous behaviour is vital for proper timing of AI and good reproductive performance, currently jeopardized by shorter observations of oestrus behaviour. Alternative indicators including progesterone (P4) recordings on-farm are tested. Oestrous intensity of 37 heifers (H) and 30 1st-parity dairy cows (C1) either Swedish Red (32) or Swedish Holstein (35) with high genetic potential for milk production, was studied in relation to AI. P4-levels in blood or milk were monitored...

  17. Clinical significance of subchondral cortical signal intensities in osteoarthritis of knee joints

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Eijiro; Torisu, Takehiko; Nakamura, Taro; Masumi, Shogo [Oita Medical Univ., Hazama (Japan); Tomari, Kazuhide; Asao, Tunenori; Takagi, Kazuhiro

    1996-09-01

    The purpose of this study was to evaluate the abnormal intensity in medial femoral condyle on MR imaging in patients with osteoarthritis of the knee. Eighty knees of fifty-eight patients with osteoarthritis of the knee were underwent plain radiography and MR imaging. According to the extension of the abnormal low intensity on T{sub 1} weighted images in medial femoral chondyle, all cases were classified into four types (no exist: 30.0%, small: 30.0%, middle: 30.0%, large: 10.0%). The extension of the abnormal low intensity was closely related to radiographic stage and femoral tibial angle. After radiological examination, in thirteen knees, the biopsy of the abnormal low intensity area on T{sub 1} weighted MR imaging was performed at the time of total knee arthroplasty. Pathological examination revealed that the causative factor of abnormal low intensity on T{sub 1} weighted MR imaging in the medial femoral condyle was trabecular hypertrophy. Our results suggest that the abnormal low intensity on T{sub 1} weighted MR imaging reflects the loading force. (author)

  18. [The acoustic characteristics of the speech signal as an indicator of the human functional state].

    Science.gov (United States)

    Lebedeva, N N; Karimova, E D

    2014-01-01

    The current review focuses on the capabilities and the efficiency of the functional state investigation based on the extralinguistic (nonsemantic) properties of the speech signal. This article provides an overview of the studies, which used such speech signal characteristics to investigate the human state during performing the operator activity, in the simulation of emotions, under emotional stress and in the presence of various mental disorders.

  19. Acoustic emission signals frequency-amplitude characteristics of sandstone after thermal treated under uniaxial compression

    Science.gov (United States)

    Kong, Biao; Wang, Enyuan; Li, Zenghua; Wang, Xiaoran; Niu, Yue; Kong, Xiangguo

    2017-01-01

    Thermally treated sandstone deformation and fracture produced abundant acoustic emission (AE) signals. The AE signals waveform contained plentiful precursor information of sandstone deformation and fracture behavior. In this paper, uniaxial compression tests of sandstone after different temperature treatments were conducted, the frequency-amplitude characteristics of AE signals were studied, and the main frequency distribution at different stress level was analyzed. The AE signals frequency-amplitude characteristics had great difference after different high temperature treatment. Significant differences existed of the main frequency distribution of AE signals during thermal treated sandstone deformation and fracture. The main frequency band of the largest waveforms proportion was not unchanged after different high temperature treatments. High temperature caused thermal damage to the sandstone, and sandstone deformation and fracture was obvious than the room temperature. The number of AE signals was larger than the room temperature during the initial loading stage. The low frequency AE signals had bigger proportion when the stress was 0.1, and the maximum value of the low frequency amplitude was larger than high frequency signals. With the increase of stress, the low and high frequency AE signals were gradually increase, which indicated that different scales ruptures were broken in sandstone. After high temperature treatment, the number of high frequency AE signals was significantly bigger than the low frequency AE signals during the latter loading stage, this indicates that the small scale rupture rate of recurrence and frequency were more than large scale rupture. The AE ratio reached the maximum during the sandstone instability failure period, and large scale rupture was dominated in the failure process. AE amplitude increase as the loading increases, the deformation and fracture of sandstone was increased gradually. By comparison, the value of the low frequency

  20. Direct Assessment of Wall Shear Stress by Signal Intensity Gradient from Time-of-Flight Magnetic Resonance Angiography.

    Science.gov (United States)

    Han, Kap-Soo; Lee, Sang Hyuk; Ryu, Han Uk; Park, Se-Hyoung; Chung, Gyung-Ho; Cho, Young I; Jeong, Seul-Ki

    2017-01-01

    The aim of the study was to calculate the arterial wall signal intensity gradient (SIG) from time-of-flight MR angiography (TOF-MRA) and represent arterial wall shear stress. We developed a new algorithm that uses signal intensity (SI) of a TOF-MRA to directly calculate the signal intensity gradient (SIG). The results from our phantom study showed that the TOF-MRA SIG could be used to distinguish the magnitude of blood flow rate as high (mean SIG ± SD, 2.2 ± 0.4 SI/mm for 12.5 ± 2.3 L/min) and low (0.9 ± 0.3 SI/mm for 8.5 ± 2.6 L/min) in vessels (p SIG values were highly correlated with various flow rates (β = 0.96, p SIG was greater than 0.8 in each section at the carotid artery (p SIG and thereby the WSS. Thus, the TOF-MRA SIG can provide clinicians with an accurate and efficient screening method for making rapid decisions on the risk of vascular disease for a patient in clinical practice.

  1. Magnetic resonance signal intensity ratio of gray/white matter in children; Quantitative assessment in developing brain

    Energy Technology Data Exchange (ETDEWEB)

    Maezawa, Mariko (Tokyo Saiseikai Central Hospital (Japan)); Seki, Tohru; Imura, Soichi; Akiyama, Kazunori; Takikawa, Itsuro; Yuasa, Yuji

    Magnetic resonance imaging (MRI) findings in 87 children with various clinical entities were used to determine the signal intensity ratio of gray/white matter in T[sub 1]-weighted and T[sub 2]-weighted images using a 1.5 T MR scanner. Signal intensity ratio changes in both T[sub 1]- and T[sub 2]-weighted images correlated well with advancing age (y=0.9349-0.001575, r=0.584, P<0.0001 in T[sub 1]-weighted images; y=0.9798+0.002854, r=0.723, P<0.0001 in T[sub 2]-weighted images), but the correlation was more linear when we included only normally developed (34) children (y=0.9689-0.001967, r=-0.654, P<0.0001 in T[sub 1]-weighted images; y=0.9882+0.002965, r=0.747, P<0.0001 in T[sub 2]-weighted images). Abnormal ratios were observed in patients with congenital hydrocephalus, inherited metabolic diseases and cerebral palsy. Although the gray/white matter differentiation would not delineate the myelination itself, measurement of the signal intensity ratio of gray/white matters is a practical way to evaluate delayed myelination in a busy MR center. (author).

  2. Partial Discharge Optical Pulse Signal Characteristics for Corona Defect in Oil Immersed Transformer

    Directory of Open Access Journals (Sweden)

    Jiabin Zhou

    2013-03-01

    Full Text Available Using fluorescent fiber sensor in transformer PD detection is a new method, based on the experimental platform for corona PD defect, the study has been carried out in order to show the typical corona PD defect optical pulse signal characteristics, PD single pulse waveform and pulses under industrial frequency cycle were acquired. The test results show that the optical method by using fluorescent fiber is effective in PD detection and corona PD optical pulse signals can accurately reflect the characteristics for this kind defect.

  3. Characteristics of seizure-induced signal changes on MRI in patients with first seizures.

    Science.gov (United States)

    Kim, Si Eun; Lee, Byung In; Shin, Kyong Jin; Ha, Sam Yeol; Park, JinSe; Park, Kang Min; Kim, Hyung Chan; Lee, Joonwon; Bae, Soo-Young; Lee, Dongah; Kim, Sung Eun

    2017-05-01

    The aim of this study was to investigate the predictive factors and identify the characteristics of the seizure-induced signal changes on MRI (SCM) in patients with first seizures. We conducted a retrospective study of patients with first seizures from March 2010 to August 2014. The inclusion criteria for this study were patients with 1) first seizures, and 2) MRI and EEG performed within 24h of the first seizures. The definition of SCM was hyper-intensities in the brain not applying to cerebral arterial territories. Multivariate logistic regression was performed with or without SCM as a dependent variable. Of 431 patients with seizures visiting the ER, 69 patients met the inclusion criteria. Of 69 patients, 11 patients (15.9%) had SCM. Epileptiform discharge on EEG (OR 29.7, 95% CI 1.79-493.37, p=0.018) was an independently significant variable predicting the presence of SCM in patients with first seizures. In addition, the topography of SCM was as follows; i) ipsilateral hippocampus, thalamus and cerebral cortex (5/11), ii) unilateral cortex (4/11), iii) ipsilateral thalamus and cerebral cortex (1/11), iv) bilateral hippocampus (1/11). Moreover, 6 out of 7 patients who underwent both perfusion CT and MRI exhibited unilateral cortical hyperperfusion with ipsilateral thalamic involvement reflecting unrestricted vascular territories. There is an association between epileptiform discharges and SCM. Additionally, the involvement of the unilateral cortex and ipsilateral thalamus in SCM and its hyperperfusion state could be helpful in differentiating the consequences of epileptic seizures from other pathologies. Copyright © 2017 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

  4. Unusual signal intensity of congenital pulmonary airway malformation on fetal magnetic resonance imaging

    Energy Technology Data Exchange (ETDEWEB)

    Owada, Keiho; Miyazaki, Osamu; Nosaka, Shunsuke [National Center for Child Health and Development, Department of Radiology, Tokyo (Japan); Matsuoka, Kentaro [National Center for Child Health and Development, Department of Pathology, Tokyo (Japan); Sago, Haruhiko [National Center for Child Health and Development, Department of Perinatal Medicine and Maternal Care, Tokyo (Japan)

    2015-05-01

    Congenital pulmonary airway malformation (CPAM) is classified into pathologically different types. These types are sometimes distinguishable by fetal lung MRI and are usually observed as higher-signal lesions on T2-weighted images than normal lung. We describe a case of unusual CPAM resembling neoplasms, with a lower signal than is found in normal lung. Histopathology showed a large number of mucogenic cells but found no evidence that could explain this feature on fetal MRI. An unusual low-signal mass associated with a pulmonary cyst in fetal lung on MRI may suggest an unusual type 1 CPAM. (orig.)

  5. Signal Characteristics of a Resistive-Strip Micromegas Detector with an Integrated Two-Dimensional Readout

    CERN Document Server

    Lin, Tai-Hua; Schott, Matthias; Valderanis, Chrysostomos; Wehner, Laura; Westenberger, Robert

    2014-01-01

    In recent years, micropattern gaseous detectors, which comprise a two-dimensional readout structure within one PCB layer, received significant attention in the development of precision and cost-effective tracking detectors in medium and high energy physics experiments. In this article, we present for the first time a systematic performance study of the signal characteristics of a resistive strip micromegas detector with a two-dimensional readout, based on test-beam and X-ray measurements. In particular, comparisons of the response of the two independent readout-layers regarding their signal shapes and signal reconstruction efficiencies are discussed.

  6. Abnormalities of hippocampal signal intensity in patients with familial mesial temporal lobe epilepsy

    Directory of Open Access Journals (Sweden)

    Coan A.C.

    2004-01-01

    Full Text Available Mesial temporal lobe epilepsy (MTLE is associated with hippocampal atrophy and hippocampal signal abnormalities. In our series of familial MTLE (FMTLE, we found a high proportion of hippocampal abnormalities. To quantify signal abnormalities in patients with FMTLE we studied 152 individuals (46 of them asymptomatic with FMTLE. We used NIH-Image® for volumetry and signal quantification in coronal T1 inversion recovery and T2 for all cross-sections of the hippocampus. Values diverging by 2 or more SD from the control mean were considered abnormal. T2 hippocampal signal abnormalities were found in 52% of all individuals: 54% of affected subjects and 48% of asymptomatic subjects. T1 hippocampal signal changes were found in 34% of all individuals: 42.5% of affected subjects and 15% of asymptomatic subjects. Analysis of the hippocampal head (first three slices revealed T2 abnormalities in 73% of all individuals (74% of affected subjects and 72% of asymptomatic subjects and T1 abnormalities in 59% (67% of affected subjects and 41% of asymptomatic subjects. Affected individuals had smaller volumes than controls (P < 0.0001. There was no difference in hippocampal volumes between asymptomatic subjects and controls, although 39% of asymptomatic patients had hippocampal atrophy. Patients with an abnormal hippocampal signal (133 individuals had smaller ipsilateral volume, but no linear correlation could be determined. Hippocampal signal abnormalities in FMTLE were more frequently found in the hippocampal head in both affected and asymptomatic family members, including those with normal volumes. These results indicate that subtle abnormalities leading to an abnormal hippocampal signal in FMTLE are not necessarily related to seizures and may be determined by genetic factors.

  7. [Pneumocystis jiroveci pneumonia: Clinical characteristics and mortality risk factors in an Intensive Care Unit].

    Science.gov (United States)

    Solano L, M F; Alvarez Lerma, F; Grau, S; Segura, C; Aguilar, A

    2015-01-01

    To describe the epidemiological characteristics of the population with Pneumocystis jiroveci (P. jiroveci) pneumonia, analyzing risk factors associated with the disease, predisposing factors for admission to an intensive care unit (ICU), and prognostic factors of mortality. A retrospective observational study was carried out, involving a cohort of patients consecutively admitted to a hospital in Spain from 1 January 2007 to 31 December 2011, with a final diagnosis of P. jiroveci pneumonia. The ICU and hospitalization service of Hospital del Mar, Barcelona (Spain). We included 36 patients with pneumonia due to P. jiroveci. Of these subjects, 16 required ICU admission (44.4%). The average age of the patients was 41.3 ± 12 years, and 23 were men (63.9%). A total of 86.1% had a history of human immunodeficiency virus (HIV) infection, and the remaining 13.9% presented immune-based disease subjected to immunosuppressive therapy. Risk factors associated to hospital mortality were age (51.8 vs. 37.3 years, P=.002), a higher APACHE score upon admission (17 vs. 13 points, P=.009), the need for invasive mechanical ventilation (27.8% vs. 11.1%, P=.000), requirement of vasoactive drugs (25.0% vs. 11.1%, P=.000), fungal coinfection (22.2% vs. 11.1%, P=.001), pneumothorax (16.7% vs. 83.3%, P=.000) and admission to the ICU (27.8% vs. 72.2% P=.000). The high requirement of mechanical ventilation and vasoactive drugs associated with fungal coinfection and pneumothorax in patients admitted to the ICU remain as risk factors associated with mortality in patients with P. jiroveci pneumonia. Copyright © 2013 Elsevier España, S.L.U. y SEMICYUC. All rights reserved.

  8. Incidence, Clinical Characteristics and Attributable Mortality of Persistent Bloodstream Infection in the Neonatal Intensive Care Unit

    Science.gov (United States)

    Hsu, Jen-Fu; Chu, Shih-Ming; Lee, Chiang-Wen; Yang, Pong-Hong; Lien, Reyin; Chiang, Ming-Chou; Fu, Ren-Huei; Huang, Hsuan-Rong; Tsai, Ming-Horng

    2015-01-01

    Background An atypical pattern of neonatal sepsis, characterized by persistent positive blood culture despite effective antimicrobial therapy, has been correlated with adverse outcomes. However, previous studies focused only on coagulate-negative staphylococcus infection. Methods All episodes of persistent bloodstream infection (BSI), defined as 3 or more consecutive positive blood cultures with the same bacterial species, at least two of them 48 hours apart, during a single sepsis episode, were enrolled over an 8-year period in a tertiary level neonatal intensive care unit. These cases were compared with all non-persistent BSI during the same period. Results We identified 81 episodes of persistent BSI (8.5% of all neonatal late-onset sepsis) in 74 infants, caused by gram-positive pathogens (n=38, 46.9%), gram-negative pathogens (n=21, 25.9%), fungus (n=20, 24.7%) and polymicrobial bacteremia (n=2, 2.5%). Persistent BSI does not differ from non-persistent BSI in most clinical characteristics and patient demographics, but tends to have a prolonged septic course, longer duration of feeding intolerance and more frequent requirement of blood transfusions. No difference was observed for death attributable to infection (9.8% vs. 6.5%), but neonates with persistent BSI had significantly higher rates of infectious complications (29.6% vs. 9.2%, P < 0.001), death from all causes (21.6% vs. 11.7%, P = 0.025), and duration of hospitalization among survivors [median (interquartile range): 80.0 (52.5-117.5) vs. 64.0 (40.0-96.0) days, P = 0.005] than those without persistent BSI. Conclusions Although persistent BSI does not contribute directly to increased mortality, the associated morbidities, infectious complications and prolonged septic courses highlight the importance of aggressive treatment to optimize outcomes. PMID:25875677

  9. Light intensity regulation of cab gene transcription is signaled by the redox state of the plastoquinone pool

    Energy Technology Data Exchange (ETDEWEB)

    Escoubas, J.M.; Lomas, M.; LaRoche, J. [Brookhaven National Lab., Upton, NY (United States)] [and others

    1995-10-24

    The eukaryotic green alga Dunaliella tertiolecta acclimates to decreased growth irradiance by increasing cellular levels of light-harvesting chlorophyll protein complex apoproteins associated with photosystem II (LHCIIs), whereas increased growth irradiance elicits the opposite response. Nuclear run-on transcription assays and measurements of cab mRNA stability established that light intensity-dependent changes in LHCII are controlled at the level of transcription. cab gene transcription in high-intensity light was partially enhanced by reducing plastoquinone with 3-(3,4-dichlorophenyl)-1,1-dimethyl urea (DCMU), whereas it was repressed in low-intensity light by partially inhibiting the oxidation of plastoquinol with 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone (DBMIB). Uncouplers of photosynthetic electron transport and inhibition of water splitting had no effect on LHCII levels. These results strongly implicate the redox state of the plastoquinone pool in the chloroplast as a photon-sensing system that is coupled to the light-intensity regulation of nuclear-encoded cab gene transcription. The accumulation of cellular chlorophyll at low-intensity light can be blocked by cytoplasmically directed phosphatase inhibitors, such as okadaic acid, microcystin L-R, and tautomycin. Gel mobility-shift assays revealed that cells grown in high-intensity light contained proteins that bind to the promoter region of a cab gene carrying sequences homologous to higher plant light-responsive elements. On the basis of these experimental results, we propose a model for a light intensity signaling system where cab gene expression is reversibly repressed by a phosphorylated factor coupled to the redox status of plastoquinone through a chloroplast protein kinase. 54 refs., 5 figs.

  10. Transcriptomic profiling of soybean in response to high-intensity UV-B irradiation reveals stress defense signaling

    Directory of Open Access Journals (Sweden)

    Min Young Yoon

    2016-12-01

    Full Text Available The depletion of the ozone layer in the stratosphere has led to a dramatic spike in ultraviolet B (UV-B intensity and increased UV-B light levels. The direct absorption of high-intensity UV-B induces complex abiotic stresses in plants, including excessive light exposure, heat, and dehydration. However, UV-B stress signaling mechanisms in plants including soybean (Glycine max [L.] remain poorly understood. Here, we surveyed the overall transcriptional responses of two soybean genotypes, UV-B-sensitive Cheongja 3 and UV-B-resistant Buseok, to continuous UV-B irradiation for 0 (control, 0.5, and 6 h using RNA-seq analysis. Homology analysis using UV-B-related genes from Arabidopsis thaliana revealed differentially expressed genes (DEGs likely involved in UV-B stress responses. Functional classification of the DEGs showed that the categories of immune response, stress defense signaling, and reactive oxygen species (ROS metabolism were over-represented. UV-B-resistant Buseok utilized phosphatidic acid-dependent signaling pathways (based on subsequent reactions of phospholipase C and diacylglycerol kinase rather than phospholipase D in response to UV-B exposure at high fluence rates, and genes involved in its downstream pathways, such as ABA signaling, mitogen-activated protein kinase cascades, and ROS overproduction, were upregulated in this genotype. In addition, the DEGs for TIR-NBS-LRR and heat shock proteins are positively activated. These results suggest that defense mechanisms against UV-B stress at high fluence rates are separate from the photomorphogenic responses utilized by plants to adapt to low-level UV light. Our study provides valuable information for deep understanding of UV-B stress defense mechanisms and for the development of resistant soybean genotypes that survive under high-intensity UV-B stress.

  11. Removing Signal Intensity Inhomogeneity From Surface Coil MRI Using Discrete Wavelet Transform and Wavelet Packet

    Science.gov (United States)

    2001-10-25

    We evaluate a combined discrete wavelet transform (DWT) and wavelet packet algorithm to improve the homogeneity of magnetic resonance imaging when a...image and uses this information to normalize the image intensity variations. Estimation of the coil sensitivity profile based on the wavelet transform of

  12. Characteristics and natural course of vertebral endplate signal (Modic) changes in the Danish general population

    DEFF Research Database (Denmark)

    Jensen, Tue S; Bendix, Tom; Sorensen, Joan S;

    2009-01-01

    BACKGROUND: Vertebral endplate signal changes (VESC) are more common among patients with low back pain (LBP) and/or sciatica than in people who are not seeking care for back pain. The distribution and characteristics of VESC have been described in people from clinical and non-clinical populations...

  13. Theoretical and experimental study of spectral characteristics of the photoacoustic signal from stochastically distributed particles.

    Science.gov (United States)

    Wang, Shaohua; Tao, Chao; Yang, Yiqun; Wang, Xueding; Liu, Xiaojun

    2015-07-01

    Photoacoustic imaging is an emerging technique which inherits the merits of optical imaging and ultrasonic imaging. However, classical photoacoustic imaging mainly makes use of the time-domain parameters of signals. In contrast to previous studies, we theoretically investigate the spectral characteristics of the photoacoustic signal from stochastic distributed particles. The spectral slope is extracted and used for describing the spectral characteristics of the photoacoustic signal. Both Gaussian and spherical distributions of optical absorption in particles are considered. For both situations, the spectral slope is monotonically decreased with the increase of particle size. In addition, the quantitative relationship between the spectral slope and the imaging system factors, including the laser pulse envelope, directivity of ultrasound transducer, and signal bandwidth, are theoretically analyzed. Finally, an idealized phantom experiment is performed to validate the analyses and examine the instrument independent of the spectral slope. This work provides a theoretical framework and new experimental evidence for spectrum analysis of the photoacoustic signal. This could be helpful for quantitative tissue evaluation and imaging based on the spectral parameters of the photoacoustic signal.

  14. TROIKA: a general framework for heart rate monitoring using wrist-type photoplethysmographic signals during intensive physical exercise.

    Science.gov (United States)

    Zhang, Zhilin; Pi, Zhouyue; Liu, Benyuan

    2015-02-01

    Heart rate monitoring using wrist-type photoplethysmographic signals during subjects' intensive exercise is a difficult problem, since the signals are contaminated by extremely strong motion artifacts caused by subjects' hand movements. So far few works have studied this problem. In this study, a general framework, termed TROIKA, is proposed, which consists of signal decomposiTion for denoising, sparse signal RecOnstructIon for high-resolution spectrum estimation, and spectral peaK trAcking with verification. The TROIKA framework has high estimation accuracy and is robust to strong motion artifacts. Many variants can be straightforwardly derived from this framework. Experimental results on datasets recorded from 12 subjects during fast running at the peak speed of 15 km/h showed that the average absolute error of heart rate estimation was 2.34 beat per minute, and the Pearson correlation between the estimates and the ground truth of heart rate was 0.992. This framework is of great values to wearable devices such as smartwatches which use PPG signals to monitor heart rate for fitness.

  15. Characteristics of low-frequency oscillation intensity of air-sea turbulent heat fluxes over the northwest Pacific

    Institute of Scientific and Technical Information of China (English)

    LI Gen; REN BaoHua; ZHENG JianOiu; WANG Jun

    2009-01-01

    Based on the daily turbulent heat fluxes and related meteorological variables dataeets (1985-2006) from Objectively Analyzed air-sea Fluxes (OAFlux) Project of Woods Hole Oceanographic Institution (WHOI), characteristics of low-frequency oscillation intensity of air-sea turbulent heat fluxes over the northwest Pacific are analyzed by linear perturbation method and correlation analysis. It can be concluded that: 1) the distribution of low-frequency oscillation intensity of latent heat flux (LHF) over the northwest Pacific is mainly affected by that of low-frequency oscillation intensity of anomalous air-eea humidity gradient (△q') as well as mean air-eea humidity gradient (△q), while the distribution of low-frequency oscillation Intensity of sensible heat flux (SHF) is mainly affected by that of low-frequency oscillation intensity of anomalous air-sea temperature gradient (△T'). 2) The low-frequency oscillation of turbulent heat fluxes over the northwest Pacific is the strongest in winter and the weakest in summer. And the seasonal transition of low-frequency oscillation intensity of LHF is jointly influenced by those of low-frequency oscillation intensity of △q', low-frequency oscillation intensity of anomalous wind speed (U'), △q and mean wind speed (U), while the seasonal transition of low-frequency oscillation intensity of SHF is mainly influenced by those of low-frequency oscillation Intensity of △T' and U. 3) Over the tropical west Pacific and sea areas north of 20ON, the low-frequency oscillation of LHF (SHF) is mainly influenced by atmospheric variables qa' (Ta') and U', indicating an oceanic response to overlying atmospheric forcing. In contrast, over the tropical eastern and central Pacific south of 20°N, qs' (Ts') also greatly influences the low-frequency oscillation of LHF (SHF).

  16. [Characteristics of nutrient loss by runoff in sloping arable land of yellow-brown under different rainfall intensities].

    Science.gov (United States)

    Chen, Ling; Liu, De-Fu; Song, Lin-Xu; Cui, Yu-Jie; Zhang, Gei

    2013-06-01

    In order to investigate the loss characteristics of N and P through surface flow and interflow under different rainfall intensities, a field experiment was conducted on the sloping arable land covered by typical yellow-brown soils inXiangxi River watershed by artificial rainfall. The results showed that the discharge of surface flow, total runoff and sediment increased with the increase of rain intensity, while the interflow was negatively correlated with rain intensity under the same total rainfall. TN, DN and DP were all flushed at the very beginning in surface flow underdifferent rainfall intensities; TP fluctuated and kept consistent in surface flow without obvious downtrend. While TN, DN and DP in interflow kept relatively stable in the whole runoff process, TP was high at the early stage, then rapidly decreased with time and kept steady finally. P was directly influenced by rainfall intensity, its concentration in the runoff increased with the increase of the rainfall intensity, the average concentration of N and P both exceeded the threshold of eutrophication of freshwater. The higher the amount of P loss was, the higher the rain intensity. The change of N loss was the opposite. The contribution rate of TN loss carried by surface flow increased from 36.5% to 57.6% with the increase of rainfall intensity, but surface flow was the primary form of P loss which contributed above 90.0%. Thus, it is crucial to control interflow in order to reduce N loss. In addition, measures should be taken to effectively manage soil erosion to mitigate P loss. The proportion of dissolved nitrogen in surface flow elevated with the decrease of rainfall intensity, but in interflow, dissolved form was predominant. P was exported mainly in the form of particulate under different rainfall intensities and runoff conditions.

  17. G-stack modulated probe intensities on expression arrays - sequence corrections and signal calibration

    Directory of Open Access Journals (Sweden)

    Fasold Mario

    2010-04-01

    Full Text Available Abstract Background The brightness of the probe spots on expression microarrays intends to measure the abundance of specific mRNA targets. Probes with runs of at least three guanines (G in their sequence show abnormal high intensities which reflect rather probe effects than target concentrations. This G-bias requires correction prior to downstream expression analysis. Results Longer runs of three or more consecutive G along the probe sequence and in particular triple degenerated G at its solution end ((GGG1-effect are associated with exceptionally large probe intensities on GeneChip expression arrays. This intensity bias is related to non-specific hybridization and affects both perfect match and mismatch probes. The (GGG1-effect tends to increase gradually for microarrays of later GeneChip generations. It was found for DNA/RNA as well as for DNA/DNA probe/target-hybridization chemistries. Amplification of sample RNA using T7-primers is associated with strong positive amplitudes of the G-bias whereas alternative amplification protocols using random primers give rise to much smaller and partly even negative amplitudes. We applied positional dependent sensitivity models to analyze the specifics of probe intensities in the context of all possible short sequence motifs of one to four adjacent nucleotides along the 25meric probe sequence. Most of the longer motifs are adequately described using a nearest-neighbor (NN model. In contrast, runs of degenerated guanines require explicit consideration of next nearest neighbors (GGG terms. Preprocessing methods such as vsn, RMA, dChip, MAS5 and gcRMA only insufficiently remove the G-bias from data. Conclusions Positional and motif dependent sensitivity models accounts for sequence effects of oligonucleotide probe intensities. We propose a positional dependent NN+GGG hybrid model to correct the intensity bias associated with probes containing poly-G motifs. It is implemented as a single-chip based calibration

  18. Increased T2 signal intensity in the distal clavicle: incidence and clinical implications

    Energy Technology Data Exchange (ETDEWEB)

    Fiorella, D.; Helms, C.A. [Dept. of Radiology, Duke Univ., Durham, NC (United States); Speer, K.P. [Dept. of Orthopedic Surgery, Duke Univ., Durham, NC (United States)

    2000-12-01

    Objective. The objectives of the current study were (1) to quantify the incidence of increased T2 signal in the distal clavicle and (2) to assess the clinical significance of this finding in patients with chronic acromioclavicular (AC) joint pain.Design and patients. Eight patients (five male and three female, 15-41 years of age) with disabling shoulder pain localized to the AC joint and marked increased T2 signal in the distal clavicle are presented. These eight patients underwent MR examination over a 25 month period (August 1996 to September 1998). The dictated reports of all shoulder MR examinations conducted over this same time period were reviewed retrospectively for the presence of signal abnormality in the distal cla-vicle. Clinical data and, in five patients, findings at shoulder arthroscopy or open surgery, were correlated with the results of MR imaging. One patient underwent arthroscopy on both shoulders.Results. The selected eight patients each presented clinically with disabling shoulder pain localized to the AC joint. One patient is presented twice, as both shoulders were symptomatic (n=9). Plain film examination (9/9) failed to indicate a structural cause of shoulder pain in any of the patients. MR examination demonstrated abnormally increased T2 signal in the distal clavicle in all nine cases and no other cause for AC joint pain. Three patients responded to a course of conservative therapy. Six experienced refractory pain despite conservative therapy. Resection of the distal clavicle was performed in five of the six cases. All patients who underwent resection of the distal clavicle experienced complete resolution of AC joint pain. A retrospective review of the dictated reports for all shoulder MR imaging examinations performed at out institution over a 25 month period (August 1996 to September 1998; n=761) demonstrated a 12.5% incidence of abnormally increased T2 signal in the distal clav-icle.Conclusions. Increased T2 signal in the distal clavicle

  19. Selective attention and the auditory vertex potential. 2: Effects of signal intensity and masking noise

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1975-01-01

    A randomized sequence of tone bursts was delivered to subjects at short inter-stimulus intervals with the tones originating from one of three spatially and frequency specific channels. The subject's task was to count the tones in one of the three channels at a time, ignoring the other two, and press a button after each tenth tone. In different conditions, tones were given at high and low intensities and with or without a background white noise to mask the tones. The N sub 1 component of the auditory vertex potential was found to be larger in response to attended channel tones in relation to unattended tones. This selective enhancement of N sub 1 was minimal for loud tones presented without noise and increased markedly for the lower tone intensity and in noise added conditions.

  20. [Study on signal transmission characteristics of meridian based on electrical network theory and experiments].

    Science.gov (United States)

    Wang, Zhi-Gong; Lü, Xiao-Ying; Gao, Jian-Yun; Wang, Yu-Hang; Huang, Cen-Yu; Chen, Yue-Lin; Xing, Li-Yang; Wang, Gui-Ying

    2011-08-01

    Study on features of acupoints with resistance test in the past half century is reviewed in this article. Mechanism and technology of the method are introduced as well as its shortcomings. The determination method of signal transmission along meridians with the combination of electrical network theories and practice is advanced. And the result of a series experiments on one meridian at the superficial part of the body are given as well. Thus, it is concluded that the signals of the point-in/point-out and the signals along a non-meridian path with the same distance are significantly different, which gives a verification of the feasibility of the method by using electrical network theories to set out characteristics of signal transmission along meridians dynamically.

  1. Cortical encoding and neurophysiological tracking of intensity and pitch cues signaling English stress patterns in native and nonnative speakers.

    Science.gov (United States)

    Chung, Wei-Lun; Bidelman, Gavin M

    2016-01-01

    We examined cross-language differences in neural encoding and tracking of intensity and pitch cues signaling English stress patterns. Auditory mismatch negativities (MMNs) were recorded in English and Mandarin listeners in response to contrastive English pseudowords whose primary stress occurred either on the first or second syllable (i.e., "nocTICity" vs. "NOCticity"). The contrastive syllable stress elicited two consecutive MMNs in both language groups, but English speakers demonstrated larger responses to stress patterns than Mandarin speakers. Correlations between the amplitude of ERPs and continuous changes in the running intensity and pitch of speech assessed how well each language group's brain activity tracked these salient acoustic features of lexical stress. We found that English speakers' neural responses tracked intensity changes in speech more closely than Mandarin speakers (higher brain-acoustic correlation). Findings demonstrate more robust and precise processing of English stress (intensity) patterns in early auditory cortical responses of native relative to nonnative speakers. Copyright © 2016 Elsevier Inc. All rights reserved.

  2. Characteristics and outcomes of end-stage renal disease patients with active tuberculosis followed in intensive care units

    Directory of Open Access Journals (Sweden)

    Ulasli Sevinc

    2009-01-01

    Full Text Available Tuberculosis (TB remains a common problem in patients with chronic renal failure. In intensive care units, misdiagnosis or delayed diagnosis of TB is common. Therefore, a description of characteristics of active TB in patients with renal failure followed in intensive care units is important to reduce mortality and transmission of the disease. This study was performed to describe the characteristics of patients with renal failure admitted to the intensive care units and having active TB and evaluate predictive factors for in hospital mortality. The hospital records of 24 patients (11 women, 13 men having ESRD and TB between 2001-2006 were reviewed. Clinical, radiological, and laboratory data on admission were recorded. Possible parameters contributing to in-hospital mortality were obtained from the medical records. In-hospital mortality rate was 66.6%. Factors associated with mortality were decreased partial pressure of oxygen and malnutrition. Fever was reported in 8 patients and hemoptysis was reported in 3 patients. Eight patients had consolidation on chest radiograph, while 4 had normal findings Seventeen patients had pulmonary involvement, and 11 had extra pulmonary involvement. The mortality rate in TB patients followed in intensive care units is high, with 3 factors contributing to in-hospital mortality. Clinicians should consider active TB in renal failure patients being followed in the intensive care unit, even when results of a chest radiograph are normal especially in patients with unexplained poor general health or respiratory failure.

  3. A computational method for the detection of activation/deactivation patterns in biological signals with three levels of electric intensity.

    Science.gov (United States)

    Guerrero, J A; Macías-Díaz, J E

    2014-02-01

    In the present work, we develop a computational technique to approximate the changes of phase in temporal series associated to electric signals of muscles which perform activities at three different levels of intensity. We suppose that the temporal series are samples of independent, normally distributed random variables with mean equal to zero, and variance equal to one of three possible values, each of them associated to a certain degree of electric intensity. For example, these intensity levels may represent a leg muscle at rest, or active during a light activity (walking), or active during a highly demanding performance (jogging). The model is presented as a maximum likelihood problem involving discrete variables. In turn, this problem is transformed into a continuous one via the introduction of continuous variables with penalization parameters, and it is solved recursively through an iterative numerical method. An a posteriori treatment of the results is used in order to avoid the detection of relatively short periods of silence or activity. We perform simulations with synthetic data in order to assess the validity of our technique. Our computational results show that the method approximates well the occurrence of the change points in synthetic temporal series, even in the presence of autocorrelated sequences. In the way, we show that a generalization of a computational technique for the change-point detection of electric signals with two phases of activity (Esquivel-Frausto et al., 2010 [40]), may be inapplicable in cases of temporal series with three levels of intensity. In this sense, the method proposed in the present manuscript improves previous efforts of the authors.

  4. A boostrap algorithm for temporal signal reconstruction in the presence of noise from its fractional Fourier transformed intensity spectra

    Energy Technology Data Exchange (ETDEWEB)

    Tan, Cheng-Yang; /Fermilab

    2011-02-01

    A bootstrap algorithm for reconstructing the temporal signal from four of its fractional Fourier intensity spectra in the presence of noise is described. An optical arrangement is proposed which realises the bootstrap method for the measurement of ultrashort laser pulses. The measurement of short laser pulses which are less than 1 ps is an ongoing challenge in optical physics. One reason is that no oscilloscope exists today which can directly measure the time structure of these pulses and so it becomes necessary to invent other techniques which indirectly provide the necessary information for temporal pulse reconstruction. One method called FROG (frequency resolved optical gating) has been in use since 19911 and is one of the popular methods for recovering these types of short pulses. The idea behind FROG is the use of multiple time-correlated pulse measurements in the frequency domain for the reconstruction. Multiple data sets are required because only intensity information is recorded and not phase, and thus by collecting multiple data sets, there is enough redundant measurements to yield the original time structure, but not necessarily uniquely (or even up to an arbitrary constant phase offset). The objective of this paper is to describe another method which is simpler than FROG. Instead of collecting many auto-correlated data sets, only two spectral intensity measurements of the temporal signal are needed in the absence of noise. The first can be from the intensity components of its usual Fourier transform and the second from its FrFT (fractional Fourier transform). In the presence of noise, a minimum of four measurements are required with the same FrFT order but with two different apertures. Armed with these two or four measurements, a unique solution up to a constant phase offset can be constructed.

  5. Optimizing the position resolution of a Z-stack microchannel plate resistive anode detector for low intensity signals

    Science.gov (United States)

    Wiggins, B. B.; Richardson, E.; Siwal, D.; Hudan, S.; deSouza, R. T.

    2015-08-01

    A method for achieving good position resolution of low-intensity electron signals using a microchannel plate resistive anode detector is demonstrated. Electron events at a rate of 7 counts s-1 are detected using a Z-stack microchannel plate. The dependence of position resolution on both the distance and the potential difference between the microchannel plate and resistive anode is investigated. Using standard commercial electronics, a measured position resolution of 170 μm (FWHM) is obtained, which corresponds to an intrinsic resolution of 157 μm (FWHM).

  6. Optimizing the position resolution of a Z-stack microchannel plate resistive anode detector for low intensity signals.

    Science.gov (United States)

    Wiggins, B B; Richardson, E; Siwal, D; Hudan, S; deSouza, R T

    2015-08-01

    A method for achieving good position resolution of low-intensity electron signals using a microchannel plate resistive anode detector is demonstrated. Electron events at a rate of 7 counts s(-1) are detected using a Z-stack microchannel plate. The dependence of position resolution on both the distance and the potential difference between the microchannel plate and resistive anode is investigated. Using standard commercial electronics, a measured position resolution of 170 μm (FWHM) is obtained, which corresponds to an intrinsic resolution of 157 μm (FWHM).

  7. Optimizing the position resolution of a Z-stack microchannel plate resistive anode detector for low intensity signals

    Energy Technology Data Exchange (ETDEWEB)

    Wiggins, B. B.; Richardson, E.; Siwal, D.; Hudan, S.; Souza, R. T. de, E-mail: desouza@indiana.edu [Department of Chemistry and Center for Exploration of Energy and Matter, Indiana University, 2401 N. Milo B. Sampson Ln., Bloomington, Indiana 47408 (United States)

    2015-08-15

    A method for achieving good position resolution of low-intensity electron signals using a microchannel plate resistive anode detector is demonstrated. Electron events at a rate of 7 counts s{sup −1} are detected using a Z-stack microchannel plate. The dependence of position resolution on both the distance and the potential difference between the microchannel plate and resistive anode is investigated. Using standard commercial electronics, a measured position resolution of 170 μm (FWHM) is obtained, which corresponds to an intrinsic resolution of 157 μm (FWHM)

  8. Fluid Signal Intensity That Mimicked A Supraspinatus Tendon Tear In A Subacromial Injected Shoulder: A Case Report

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Hun; Kim, Tae Eun; Shin, Hyun Woong [Daegu Fatima Hospital, Daegu (Korea, Republic of)

    2010-06-15

    Subacromial steroid injections are a common procedure for treating shoulder pain. Several studies have reported on the difficulty of performing an accurate injection into the subacromial bursa, as well as the injected material infiltrated into other regional structures even when an accurate injection was done into the subacromial space. These misplacements, and especially in the rotator cuff, creates high signal intensity on T2WI that can mimic a rotator cuff tear. Bergman and Fredericson found that the bursal and extrabursal fluid is resolved or decreased 3 days after the injection, so they recommended a 3-day delay after the shoulder injection before performing MRI to prevent misinterpretation of the signal changes. We report here on a case of a false fullthickness tear of the supraspinatus tendon on MRI one month after subacromial injection, and the supraspinatus tendon turned out to be intact on the follow up ultrasonography and arthroscopic examination

  9. Suppression of phase-induced intensity noise in fibre optic delay line signal processors using an optical phase modulation technique.

    Science.gov (United States)

    Chan, Erwin H W

    2010-10-11

    A technique that can suppress the dominant phase-induced intensity noise in fibre optic delay line signal processors is presented. It is based on phase modulation of the optical carrier to distribute the phase noise at the information band into a high frequency band which can be filtered out. This technique is suitable for suppressing the phase noise in various delay line structures and for integrating in the conventional fibre optic links. It can also suppress the coherent interference effect at the same time. A model for predicting the amount of phase noise reduction in various delay line structures using the optical phase modulation technique is presented for the first time and is experimentally verified. Experimental results demonstrate the technique can achieve a large phase noise reduction in various fibre optic delay line signal processors.

  10. The effectiveness of the jammer signal characteristics on conical-scan systems

    Science.gov (United States)

    Şahingil, Mehmet C.; Aslan, Murat Ş.

    2015-05-01

    Being passive systems and due to their proliferation to many regions in the world, the infrared (IR) guided missiles constitute probably the most dangerous threats for the aircraft platforms. Early generation surface-to-air and air-to-air IRguided missiles use reticle-based seekers. One of the IR countermeasure (IRCM) techniques for protecting aircraft platforms against these type of threats is to use a modulated jamming signal. Optimizing the parameters of the modulation is the most important issue for an effective protection. If the required characteristic is not satisfied, jamming may not be successful for protecting the aircraft. There are several parameters to define the jammer signal (modulation) characteristic. Optimizing them requires a good understanding of threat seekers' operating principles. In the present paper, we consider protection of a helicopter platform against conical-scan reticle based seeker systems and investigate the effect of the jammer signal modulation parameters on jamming performance via extensive batch simulations. The simulations are performed in a MATLAB-coded simulator which models reticle-based conical-scan seeker, aircraft radiation, aircraft motion and jammer system on the aircraft. The results show that if the properties of the jammer signal are similar to those of the reticle-modulated signal in the missile, the jamming can be successful. Otherwise, applied jamming may not deceive the threat seeker.

  11. Rainfall intensity characteristics at coastal and high altitude stations in Kerala

    Indian Academy of Sciences (India)

    V Sasi Kumar; S Sampath; P V S S K Vinayak; R Harikumar

    2007-10-01

    Rainfall intensities measured at a few stations in Kerala during 2001 –2005 using a disdrometer were found to be in reasonable agreement with the total rainfall measured using a manual rain gauge. The temporal distributions of rainfall intensity at different places and during different months show that rainfall is of low intensity (> 10 mm/hr),65%to 90%of the time.This could be an indication of the relative prevalence of stratiform and cumuliform clouds.Rainfall was of intensity > 5 mm/hr for more than 95%of the time in Kochi in July 2002,which was a month seriously deficient in rainfall,indicating that the deficiency was probably due to the relative absence of cumuliform clouds.Cumulative distribution graphs are also plotted and fitted with the Weibull distribution.The fit parameters do not appear to have any consistent pattern. The higher intensities also contributed signi ficantly to total rainfall most of the time,except in Munnar (a hill station). In this analysis also,the rainfall in Kochi in July 2002 was found to have less presence of high intensities. This supports the hypothesis that the rainfall de ficiency was probably caused by the absence of conditions that favoured the formation of cumuliform clouds.

  12. Morphological characteristics of waste polyethylene/polypropylene plastics during pyrolysis and representative morphological signal characterizing pyrolysis stages.

    Science.gov (United States)

    Wang, H; Chen, D; Yuan, G; Ma, X; Dai, X

    2013-02-01

    In this work, the morphological characteristics of waste polyethylene (PE)/polypropylene (PP) plastics during their pyrolysis process were investigated, and based on their basic image changing patterns representative morphological signals describing the pyrolysis stages were obtained. PE and PP granules and films were used as typical plastics for testing, and influence of impurities was also investigated. During pyrolysis experiments, photographs of the testing samples were taken sequentially with a high-speed infrared camera, and the quantitative parameters that describe the morphological characteristics of these photographs were explored using the "Image Pro Plus (v6.3)" digital image processing software. The experimental results showed that plastics pyrolysis involved four stages: melting, two stages of decomposition which are characterized with bubble formation caused by volatile evaporating, and ash deposition; and each stage was characterized with its own phase changing behaviors and morphological features. Two stages of decomposition are the key step of pyrolysis since they took up half or more of the reaction time; melting step consumed another half of reaction time in experiments when raw materials were heated up from ambient temperatures; and coke-like deposition appeared as a result of decomposition completion. Two morphological signals defined from digital image processing, namely, pixel area of the interested reaction region and bubble ratio (BR) caused by volatile evaporating were found to change regularly with pyrolysis stages. In particular, for all experimental scenarios with plastics films and granules, the BR curves always exhibited a slowly drop as melting started and then a sharp increase followed by a deep decrease corresponding to the first stage of intense decomposition, afterwards a second increase - drop section corresponding to the second stage of decomposition appeared. As ash deposition happened, the BR dropped to zero or very low

  13. Positive autoregulation shapes response timing and intensity in two-component signal transduction systems.

    Science.gov (United States)

    Mitrophanov, Alexander Y; Hadley, Tricia J; Groisman, Eduardo A

    2010-08-27

    Positive feedback loops are regulatory elements that can modulate expression output, kinetics and noise in genetic circuits. Transcriptional regulators participating in such loops are often expressed from two promoters, one constitutive and one autoregulated. Here, we investigate the interplay of promoter strengths and the intensity of the stimulus activating the transcriptional regulator in defining the output of a positively autoregulated genetic circuit. Using a mathematical model of two-component regulatory systems, which are present in all domains of life, we establish that positive feedback strongly affects the steady-state output levels at both low and high levels of stimulus if the constitutive promoter of the regulator is weak. By contrast, the effect of positive feedback is negligible when the constitutive promoter is sufficiently strong, unless the stimulus intensity is very high. Furthermore, we determine that positive feedback can affect both transient and steady state output levels even in the simplest genetic regulatory systems. We tested our modeling predictions by abolishing the positive feedback loop in the two-component regulatory system PhoP/PhoQ of Salmonella enterica, which resulted in diminished induction of PhoP-activated genes. Copyright (c) 2010 Elsevier Ltd. All rights reserved.

  14. On the occurrence and characteristics of intense low-altitude electric fields observed by Freja

    Directory of Open Access Journals (Sweden)

    G. Marklund

    Full Text Available High-resolution measurements by the double probe electric field instrument on the Freja satellite are presented. The observations show that extremely intense (up to 1 V m–1 and fine-structured (<1 km electric fields exist at auroral latitudes within the altitude regime explored by Freja (up to 1700 km. The intense field events typically occur within the early morning sector of the auroral oval (01–07 MLT during times of geomagnetic activity. In contrast to the observations within the auroral acceleration region characterized by intense converging electric fields associated with electron precipitation, upward ion beams and upward field-aligned currents, the intense electric fields observed by Freja are often found to be diverging and located within regions of downward field-aligned currents outside the electron aurora. Moreover, the intense fields are observed in conjunction with precipitating and transversely energized ions of energies 0.5–1 keV and may play an important role in the ion heating. The observations suggest that the intense electric field events are associated with small-scale low-conductivity ionospheric regions void of auroral emissions such as east-west aligned dark filaments or vortex streets of black auroral curls located between or adjacent to auroral arcs within the morningside diffuse auroral region. We suggest that these intense fields also exist at ionospheric altitudes although no such observations have yet been made. This is possible since the height-integrated conductivity associated with the dark filaments may be as low as 0.1 S or less. In addition, Freja electric field data collected outside the auroral region are discussed with particular emphasis on subauroral electric fields which are observed within the 19–01 MLT sector between the equatorward edge of the auroral oval and the inner edge of the ring current.

  15. Experimental Study of Umts Radio Signal Propagation Characteristics by Field Measurement

    Directory of Open Access Journals (Sweden)

    Isabona Joseph

    2013-07-01

    Full Text Available Knowledge of propagation characteristics in the mobile channel is important to the design, analysis and optimisation of a cellular system. Such need is of great concern to achieve higher quality standards, lower overall running cost, minimize transmit power, better covering of different areas with different environmental situations. Thus, received signal prediction models play an important role in the RF coverage optimization and efficient use of the available resources in wireless communication. As the demand of location based services (LBS increases in non-line of site (NLOS environment, a robust received signal prediction model is needed to enhance the accuracy of the LBS techniques. This paper presents a large scale received signal prediction model for various types of propagation environment from field measured signal data. Based on the experimental data obtained, path loss exponent and standard deviation of signal strength variability are determined. It is shown that the values of these parameters vary from study location to location in the coverage area. The results indicate that different empirical models for mean signal strength should be used in different regions of the coverage area for cellular network planning.

  16. Autodyne characteristics of stabilized UHF-oscillators at a strong reflected signal

    Directory of Open Access Journals (Sweden)

    Noskov V. Ya.

    2011-11-01

    Full Text Available Calculations and examinations of phase, amplitude, frequency and amplitude-frequency characteristics are fulfilled for the autodyne system stabilized by the external high-Q cavity as well as spectral characteristics under condition of exact and non-exact cavity tuning and the variations of distance to reflector. The distinguished peculiarities of the autodyne response at the small and large reflected signal are described. Experimental research results are discussed fulfilled on an example of the hybrid-integrated oscillator on Gunn diode of 8-mm-range, which confirm qualitatively the theoretic results.

  17. Study on signal intensity of low field nuclear magnetic resonance via an indirect coupling measurement

    Institute of Scientific and Technical Information of China (English)

    Jiang Feng-Ying; Wang Ning; Jin Yi-Rong; Deng Hui; Tian Ye; Lang Pei-Lin; Li Jie

    2013-01-01

    We carry out an ultra-low-field nuclear magnetic resonance (NMR) experiment based on high-Tc superconducting quantum interference devices (SQUIDs).The measurement field is in a micro-tesla range (~10 μT-100 μT) and the experiment is conducted in a home-made magnetically-shielded-room (MSR).The measurements are performed by the indirect coupling method in which the signal of nuclei precession is indirectly coupled to the SQUID through a tuned copper coil transformer.In such an arrangement,the interferences of applied measurement and polarization field to the SQUID sensor are avoided and the performance of the SQUID is not destroyed.In order to compare the detection sensitivity obtained by using the SQUID with that achieved using a conventional low-noise-amplifier,we perform the measurements using a connercial room temperature amplifier.The results show that in a wide frequency range (~1 kHz-10 kHz) the measurements with the SQUID sensor exhibit a higher signal-to-noise ratio,Further,we discuss the dependence of NMR peak magnitude on measurement frequency.We attribute the reduction of the peak magnitude at high frequency to the increased field inhomogeneity as the measurement field increases.This is verified by compensating the field gradient using three sets of gradient coils.

  18. Intensity-dependent modulation of optically active signals in a chiral metamaterial

    Science.gov (United States)

    Rodrigues, Sean P.; Lan, Shoufeng; Kang, Lei; Cui, Yonghao; Panuski, Patrick W.; Wang, Shengxiang; Urbas, Augustine M.; Cai, Wenshan

    2017-01-01

    Chiral media exhibit optical phenomena that provide distinctive responses from opposite circular polarizations. The disparity between these responses can be optimized by structurally engineering absorptive materials into chiral nanopatterns to form metamaterials that provide gigantic chiroptical resonances. To fully leverage the innate duality of chiral metamaterials for future optical technologies, it is essential to make such chiroptical responses tunable via external means. Here we report an optical metamaterial with tailored chiroptical effects in the nonlinear regime, which exhibits a pronounced shift in its circular dichroism spectrum under a modest level of excitation power. Strong nonlinear optical rotation is observed at key spectral locations, with an intensity-induced change of 14° in the polarization rotation from a metamaterial thickness of less than λ/7. The modulation of chiroptical responses by manipulation of input powers incident on chiral metamaterials offers potential for active optics such as all-optical switching and light modulation. PMID:28240288

  19. Optimization of parameters affecting signal intensity in an LTQ-orbitrap in negative ion mode: A design of experiments approach.

    Science.gov (United States)

    Lemonakis, Nikolaos; Skaltsounis, Alexios-Leandros; Tsarbopoulos, Anthony; Gikas, Evagelos

    2016-01-15

    A multistage optimization of all the parameters affecting detection/response in an LTQ-orbitrap analyzer was performed, using a design of experiments methodology. The signal intensity, a critical issue for mass analysis, was investigated and the optimization process was completed in three successive steps, taking into account the three main regions of an orbitrap, the ion generation, the ion transmission and the ion detection regions. Oleuropein and hydroxytyrosol were selected as the model compounds. Overall, applying this methodology the sensitivity was increased more than 24%, the resolution more than 6.5%, whereas the elapsed scan time was reduced nearly to its half. A high-resolution LTQ Orbitrap Discovery mass spectrometer was used for the determination of the analytes of interest. Thus, oleuropein and hydroxytyrosol were infused via the instruments syringe pump and they were analyzed employing electrospray ionization (ESI) in the negative high-resolution full-scan ion mode. The parameters of the three main regions of the LTQ-orbitrap were independently optimized in terms of maximum sensitivity. In this context, factorial design, response surface model and Plackett-Burman experiments were performed and analysis of variance was carried out to evaluate the validity of the statistical model and to determine the most significant parameters for signal intensity. The optimum MS conditions for each analyte were summarized and the method optimum condition was achieved by maximizing the desirability function. Our observation showed good agreement between the predicted optimum response and the responses collected at the predicted optimum conditions.

  20. MICROST: A mixed approach for heart rate monitoring during intensive physical exercise using wrist-type PPG Signals.

    Science.gov (United States)

    Zhu, Shilin; Tan, Ke; Zhang, Xinyu; Liu, Zhiqiang; Liu, Bin

    2015-01-01

    The performance of heart rate (HR) monitoring using wrist-type photoplethysmographic (PPG) signals is strongly influenced by motion artifacts (MAs), since the intensive physical exercises are common in real world. Few works focus on this study so far because of unsatisfying quality of corrupted PPG signals. In this paper, we propose an accurate and efficient strategy, named MICROST, which estimates heart rate based on a mixed approach. The MICROST framework is designed as a MIxed algorithm which consists of acceleration Classification (AC), fiRst-frame prOcessing and heuriStic Tracking. Experimental results using recordings from 12 subjects during fast running and intensive movement showed the average absolute error of heart rate estimation was 2.58 beat per minute (BPM), and the Pearson correlation between the estimates and the ground-truth of heart rate was 0.988. We discuss our approach in real time to face the applications of wearable devices such as smart-watches in reality.

  1. Preoperative diagnosis of breast diseases by dynamic MR mammography. Cut off point establishment for signal intensity ratio

    Energy Technology Data Exchange (ETDEWEB)

    Tsuchiya, Juji; Nagata, Takayasu; Kawagoe, Hajime; Tachibana, Susumu; Kajima, Toshihiko; Hoshino, Mutsuo [Ibi General Hospital, Gifu (Japan); Uno, Takashi; Shimokawa, Kuniyasu

    1997-12-01

    We have revealed that a dynamic study of the breast using MR imaging technique can estimate objectively benign-malignant differentiative diagnosis. Subjects were 41 cases of breast lesion, including 13 cases of breast cancer, 21 cases of mastopathy, six cases of fibroadenoma and one case of intraductal papillomatosis and the results of them were investigated in comparison with histopathological diagnosis. As so the method, we drew up time-signal intensity ratio curve plotting signal intensity ratio at each 30 second of dynamic MR mammography after Gd-DTPA administration. We found a especially high significant difference between cancer and mastopathy, within 90 second after Gd-DTPA administration (p=0.0000). Still more, we established cut off point concerning with establishment of 95% confidence interval, that is, at 30 second after Gd-DTPA administration of point equivalent 1.53 at 60 second equivalent 2.00, at 90 second equivalent 2.47, and about this estimating maneuver using the cut off point we named Dynamic ratio method. We can estimate preoperatively not only benign-malignant differentiative diagnosis with breast tumor, but also neighboring infiltration and lymph node metastasis of breast cancer using this Dynamic ratio method. Over again, Dynamic ratio method provides fine information to preoperative decision of resecting region for breast conserving surgery. The efficiency of this method is sensitivity=92.3%, specificity=89.3% and positive predictive value=80.0%. (author)

  2. Assessment of lung development in isolated congenital diaphragmatic hernia using signal intensity ratios on fetal MR imaging.

    Science.gov (United States)

    Balassy, Csilla; Kasprian, Gregor; Brugger, Peter C; Weber, Michael; Csapo, Bence; Herold, Christian; Prayer, Daniela

    2010-04-01

    To investigate developmental changes in the apparently unaffected contralateral lung by using signal intensity ratios (SIR) and lung volumes (LV), and to search for correlation with clinical outcome. Twenty-five fetuses (22-37 weeks' gestation) were examined. Lung/liver signal intensity ratios (LLSIR) were assessed on T1-weighted and T2-weighted sequences for both lungs, then together with LV compared with age-matched controls of 91 fetuses by using the U test. Differences in LLSIRs and lung volumes were correlated with neonatal outcomes. LLSIRs in fetuses with congenital diaphragmatic hernia (CDH) were significantly higher in both lungs on T1-weighted images and significantly lower on T2-weighted images, compared with normals (p < 0.05), increasing on T2-weighted imaging and decreasing on T1-weighted imaging during gestation. Total LV were significantly smaller in the CDH group than in controls (p < 0.05). No significant differences in LLSIR of the two lungs were found. Outcomes correlated significantly with total LV, but not with LLSIR. Changes in LLSIR seem to reflect developmental impairment in CDH; however, they provide no additional information in predicting outcome. LV remains the best indicator on fetal MR imaging of neonatal survival in isolated, left-sided CDH.

  3. Assessment of lung development in isolated congenital diaphragmatic hernia using signal intensity ratios on fetal MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Balassy, Csilla; Kasprian, Gregor; Weber, Michael; Herold, Christian; Prayer, Daniela [Medical University of Vienna, Department of Radiology, Vienna (Austria); Brugger, Peter C. [Medical University of Vienna, Centre of Anatomy and Cell Biology, Vienna (Austria); Csapo, Bence [Medical University of Vienna, Department of Obstetrics and Gyneocology, Vienna (Austria)

    2010-04-15

    To investigate developmental changes in the apparently unaffected contralateral lung by using signal intensity ratios (SIR) and lung volumes (LV), and to search for correlation with clinical outcome. Twenty-five fetuses (22-37 weeks' gestation) were examined. Lung/liver signal intensity ratios (LLSIR) were assessed on T1-weighted and T2-weighted sequences for both lungs, then together with LV compared with age-matched controls of 91 fetuses by using the U test. Differences in LLSIRs and lung volumes were correlated with neonatal outcomes. LLSIRs in fetuses with congenital diaphragmatic hernia (CDH) were significantly higher in both lungs on T1-weighted images and significantly lower on T2-weighted images, compared with normals (p < 0.05), increasing on T2-weighted imaging and decreasing on T1-weighted imaging during gestation. Total LV were significantly smaller in the CDH group than in controls (p < 0.05). No significant differences in LLSIR of the two lungs were found. Outcomes correlated significantly with total LV, but not with LLSIR. Changes in LLSIR seem to reflect developmental impairment in CDH; however, they provide no additional information in predicting outcome. LV remains the best indicator on fetal MR imaging of neonatal survival in isolated, left-sided CDH. (orig.)

  4. The ARMA model's pole characteristics of Doppler signals from the carotid artery and their classification application

    Institute of Scientific and Technical Information of China (English)

    CHEN Xi; WANG Yuanyuan; ZHANG Yu; WANG Weiqi

    2002-01-01

    In order to diagnose the cerebral infarction, a classification system based onthe ARMA model and BP (Back-Propagation) neural network is presented to analyzeblood flow Doppler signals from the carotid artery. In this system, an ARMA modelis first used to analyze the audio Doppler blood flow signals from the carotid artery.Then several characteristic parameters of the pole's distribution are estimated. Afterstudies of these characteristic parameters' sensitivity to the textcolor cerebral infarctiondiagnosis, a BP neural network using sensitive parameters is established to classify thenormal or abnormal state of the cerebral vessel. With 474 cases used to establish theappropriate neural network, and 52 cases used to test the network, the results showthat the correct classification rate of both training and testing are over 94%. Thus thissystem is useful to diagnose the cerebral infarction.

  5. Using naive Bayes classifier for classification of convective rainfall intensities based on spectral characteristics retrieved from SEVIRI

    Indian Academy of Sciences (India)

    Slimane Hameg; Mourad Lazri; Soltane Ameur

    2016-07-01

    This paper presents a new algorithm to classify convective clouds and determine their intensity, based oncloud physical properties retrieved from the Spinning Enhanced Visible and Infrared Imager (SEVIRI).The convective rainfall events at 15 min, 4 × 5 km spatial resolution from 2006 to 2012 are analysed overnorthern Algeria. The convective rain classification methodology makes use of the relationship betweencloud spectral characteristics and cloud physical properties such as cloud water path (CWP), cloudphase (CP) and cloud top height (CTH). For this classification, a statistical method based on ‘naiveBayes classifier’ is applied. This is a simple probabilistic classifier based on applying ‘Bayes’ theoremwith strong (naive) independent assumptions. For a 9-month period, the ability of SEVIRI to classifythe rainfall intensity in the convective clouds is evaluated using weather radar over the northern Algeria.The results indicate an encouraging performance of the new algorithm for intensity differentiation ofconvective clouds using SEVIRI data.

  6. Characteristics of the most intense lightning storm ever recorded at the CN Tower

    Science.gov (United States)

    Hussein, A. M.; Kazazi, S.; Anwar, M.; Yusouf, M.; Liatos, P.

    2017-02-01

    Lightning strikes to the CN Tower have been optically observed since 1978. In 1990, five independent systems started to operate to simultaneously record parameters of lightning strikes to the tower, including the time derivative of the current, the associated electric and magnetic fields, and the channel optical characteristics. On August 24, 2011, during an unusually severe lightning storm, video records showed that the CN Tower was struck with 52 lightning flashes within 84 min and 6.9 s. Thus, this storm produced, on average, a flash to the tower every 99 s. However, the CN Tower lightning current derivative measurement system only recorded 32 flashes, which were perfectly time-matched with 32 of the 52 video-recorded flashes. It is found that the current derivative measurement system recorded every video-recorded flash that contained at least one return stroke. Based on the analysis of video records, it is noted that each of the storm's 52 flashes contains an initial-stage current, proving that all flashes were upward initiated. This unique CN Tower storm - the most intense ever recorded at the tower - is here thoroughly analyzed, based on video and current records. The inter-flash time within the storm is found to vary between 10.6 s and 274 s, with an overall average of 98 s. It is also found that the inter-flash time between successive non-return-stroke flashes is on average 64% longer than that for successive flashes containing return strokes. Statistical analysis of video and current data clearly reveals that the time duration of flashes containing initial-stage currents and return strokes is on average 27% longer than that of flashes that only have initial-stage currents. Furthermore, it is important to note that the time duration of the initial-stage current in flashes containing no return strokes is on average 76% longer than that in flashes containing return strokes. Therefore, it is possible to conclude that if the time duration of the initial

  7. Optimizing signal intensity correction during evaluation of hepatic parenchymal enhancement on gadoxetate disodium-enhanced MRI: Comparison of three methods

    Energy Technology Data Exchange (ETDEWEB)

    Onoda, Minori, E-mail: onoda@radt.med.kindai.ac.jp [Department of Radiological Technology, Kinki University Hospital, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942 (Japan); Hyodo, Tomoko, E-mail: neneth@m.ehime-u.ac.jp [Department of Radiology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Murakami, Takamichi, E-mail: murakami@med.kindai.ac.jp [Department of Radiology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Okada, Masahiro, E-mail: okada777@med.u-ryukyu.ac.jp [Department of Radiology, Kinki University Faculty of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Uto, Tatsuro, E-mail: chuho@med.kindai.ac.jp [Department of Radiological Technology, Kinki University Hospital, 377-2 Ohno-Higashi, Osaka-Sayama, Osaka 589-8511 (Japan); Hori, Masatoshi, E-mail: mhori@radiol.med.osaka-u.ac.jp [Department of Radiology, Osaka University Graduate School of Medicine, 2-2 Yamadaoka, Suita, Osaka 565-0871 (Japan); Miyati, Tosiaki, E-mail: ramiyati@mhs.mp.kanazawa-u.ac.jp [Division of Health Sciences, Graduate School of Medical Science, Kanazawa University, 5-11-80 Kodatsuno, Kanazawa, Ishikawa 920-0942 (Japan)

    2015-03-15

    Highlights: •Signal intensity is often used to evaluate hepatic enhancement with Gd-EOB-DTPA in the hepatobiliary phase. •Comparison of uncorrected signal intensity with T{sub 1} value revealed signal intensity instability. •Measurement of uncorrected liver SI or SNR often yields erroneous results on late-phase gadoxetate MRI due to shimming and other optimization techniques. •Signal intensity corrected by scale and rescale slope from DICOM data gave comparable results. -- Abstract: Objective: To compare signal intensity (SI) correction using scale and rescale slopes with SI correction using SIs of spleen and muscle for quantifying multiphase hepatic contrast enhancement with Gd-EOB-DTPA by assessing their correlation with T{sub 1} values generated from Look-Locker turbo-field-echo (LL-TFE) sequence data (ER-T{sub 1}). Materials and methods: Thirty patients underwent Gd-EOB-DTPA-enhanced magnetic resonance imaging (MRI) in this prospective clinical study. For each patient, breath-hold T{sub 1}-weighted fat-suppressed three-dimensional (3D) gradient echo sequences (e-THRIVE) were acquired before and 2 (first phase), 10 (second phase), and 20 min (third phase) after intravenous Gd-EOB-DTPA. Look-Locker turbo-field-echo (LL-TFE) sequences were acquired before and 1.5 (first phase), 8 (second phase), and 18 min (third phase) postcontrast. The liver parenchyma enhancement ratios (ER) of each phase were calculated using the SI from e-THRIVE sequences (ER-SI) and the T{sub 1} values generated from LL-TFE sequence data (ER-T{sub 1}) respectively. ER-SIs were calculated in three ways: (1) comparing with splenic SI (ER-SI-s), (2) comparing with muscle SI (ER-SI-m), (3) using scale and rescale slopes obtained from DICOM headers (ER-SI-c), to eliminate the effects of receiver gain and scaling. For each of the first, second and third phases, correlation and agreement were assessed between each ER-SI and ER-T{sub 1}. Results: In the first phase, all ER-SIs correlated

  8. BOLD fMRI signal characteristics of S1- and S2-SSFP at 7 Tesla

    NARCIS (Netherlands)

    Goa, Pål E; Koopmans, Peter J; Poser, Benedikt A; Barth, Markus; Norris, David G

    2014-01-01

    OBJECT: To compare the BOLD fMRI signal characteristics at in the cortex and on the pial surface for a non-balanced steady-state free precession sequence (nb-SSFP) at 7 T. MATERIALS AND METHODS: A multi-echo nb-SSFP sequence was used for high resolution fMRI at 7 T. Two S1 (S(+)) echoes at different

  9. Diffuse excessive high signal intensity in low-risk preterm infants at term-equivalent age does not predict outcome at 1 year: a prospective study

    Energy Technology Data Exchange (ETDEWEB)

    Leitner, Yael [Tel Aviv Sourasky Medical Centre, Child Development Centre, Dana-Dwek Children' s Hospital, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Weinstein, Maya [Tel Aviv Sourasky Medical Centre, Functional Brain Centre, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Bar Ilan University, Department of Psychology, Gonda Multidisciplinary Brain Research Centre, Ramat-Gan (Israel); Myers, Vicki [Tel Aviv Sourasky Medical Centre, Functional Brain Centre, The Wohl Institute for Advanced Imaging, Tel Aviv (Israel); Uliel, Shimrit; Geva, Karen [Tel Aviv Sourasky Medical Centre, Child Development Centre, Dana-Dwek Children' s Hospital, Tel Aviv (Israel); Berger, Irit; Marom, Ronella [Tel Aviv Sourasky Medical Centre, Department of Neonatology, Lis Maternity Hospital, Tel Aviv (Israel); Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Bashat, Dafna Ben [Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Tel Aviv University, Sagol School of Neuroscience, Tel Aviv (Israel); Ben-Sira, Liat [Tel Aviv University, Sackler Faculty of Medicine, Tel Aviv (Israel); Tel Aviv Sourasky Medical Centre, Department of Radiology, Tel Aviv (Israel); Geva, Ronny [Bar Ilan University, Department of Psychology, Gonda Multidisciplinary Brain Research Centre, Ramat-Gan (Israel); Gross-Tsur, Varda [Shaare-Zedek Medical Centre, Neuropediatric Unit, Jerusalem (Israel)

    2014-08-15

    The outcome of premature infants with only diffuse excessive high signal intensity (DEHSI) is not clear. We explored the relationship between DEHSI, white matter (WM) diffusion characteristics, perinatal characteristics, and neurobehavioral outcome at 1 year in a homogenous group of preterm infants without major brain abnormalities. Fifty-eight preterm infants, gestational age 29 ± 2.6 weeks, underwent an MRI at term-equivalent age (TEA). Griffiths Mental Developmental Scales, neurological assessment, and Parental Stress Index (PSI) were performed at 1 year corrected age. These measures were compared between preterm infants according to DEHSI classification (none, mild, moderate). Diffusion tensor imaging was used in major WM volumes of interest to objectively measure the degree of WM maturation. No significant differences were detected in the perinatal risk characteristics, neurobehavioral outcome, and PSI at 1 year between infants with different DEHSI classifications. In infants with DEHSI, increased axial and radial diffusivities were detected in the optic radiations, centrum semiovale, and posterior limb of the internal capsule, indicating less advanced maturation of the WM. Significant correlations were detected between the time interval from birth to MRI and the WM microstructure in infants without DEHSI. DEHSI in premature infants is neither a predictive measure for short-term adverse neurobehavioral outcome nor related to perinatal risk characteristics. Extrauterine exposure time had a differential effect on WM maturational trajectories in infants with DEHSI compared to those without. We suggest DEHSI may represent an alteration in WM maturational characteristics. Further follow-up studies may verify later consequences of DEHSI in premature infants. (orig.)

  10. Intensity-based signal separation algorithm for accuratequantification of clustered centrosomes in tissue sections

    Energy Technology Data Exchange (ETDEWEB)

    Fleisch, Markus C.; Maxell, Christopher A.; Kuper, Claudia K.; Brown, Erika T.; Parvin, Bahram; Barcellos-Hoff, Mary-Helen; Costes,Sylvain V.

    2006-03-08

    Centrosomes are small organelles that organize the mitoticspindle during cell division and are also involved in cell shape andpolarity. Within epithelial tumors, such as breast cancer, and somehematological tumors, centrosome abnormalities (CA) are common, occurearly in disease etiology, and correlate with chromosomal instability anddisease stage. In situ quantification of CA by optical microscopy ishampered by overlap and clustering of these organelles, which appear asfocal structures. CA has been frequently associated with Tp53 status inpremalignant lesions and tumors. Here we describe an approach toaccurately quantify centrosomes in tissue sections and tumors.Considering proliferation and baseline amplification rate the resultingpopulation based ratio of centrosomes per nucleus allow the approximationof the proportion of cells with CA. Using this technique we show that20-30 percent of cells have amplified centrosomes in Tp53 null mammarytumors. Combining fluorescence detection, deconvolution microscopy and amathematical algorithm applied to a maximum intensity projection we showthat this approach is superior to traditional investigator based visualanalysis or threshold-based techniques.

  11. Signal intensities derived from different NMR probes and parameters contribute to variations in quantification of metabolites.

    Directory of Open Access Journals (Sweden)

    Paige Lacy

    Full Text Available We discovered that serious issues could arise that may complicate interpretation of metabolomic data when identical samples are analyzed at more than one NMR facility, or using slightly different NMR parameters on the same instrument. This is important because cross-center validation metabolomics studies are essential for the reliable application of metabolomics to clinical biomarker discovery. To test the reproducibility of quantified metabolite data at multiple sites, technical replicates of urine samples were assayed by 1D-(1H-NMR at the University of Alberta and the University of Michigan. Urine samples were obtained from healthy controls under a standard operating procedure for collection and processing. Subsequent analysis using standard statistical techniques revealed that quantitative data across sites can be achieved, but also that previously unrecognized NMR parameter differences can dramatically and widely perturb results. We present here a confirmed validation of NMR analysis at two sites, and report the range and magnitude that common NMR parameters involved in solvent suppression can have on quantitated metabolomics data. Specifically, saturation power levels greatly influenced peak height intensities in a frequency-dependent manner for a number of metabolites, which markedly impacted the quantification of metabolites. We also investigated other NMR parameters to determine their effects on further quantitative accuracy and precision. Collectively, these findings highlight the importance of and need for consistent use of NMR parameter settings within and across centers in order to generate reliable, reproducible quantified NMR metabolomics data.

  12. Impacts of Fog Characteristics, Forward Illumination, and Warning Beacon Intensity Distribution on Roadway Hazard Visibility.

    Science.gov (United States)

    Bullough, John D; Rea, Mark S

    2016-01-01

    Warning beacons are critical for the safety of transportation, construction, and utility workers. These devices need to produce sufficient luminous intensity to be visible without creating glare to drivers. Published standards for the photometric performance of warning beacons do not address their performance in conditions of reduced visibility such as fog. Under such conditions light emitted in directions other than toward approaching drivers can create scattered light that makes workers and other hazards less visible. Simulations of visibility of hazards under varying conditions of fog density, forward vehicle lighting, warning beacon luminous intensity, and intensity distribution were performed to assess their impacts on visual performance by drivers. Each of these factors can influence the ability of drivers to detect and identify workers and hazards along the roadway in work zones. Based on the results, it would be reasonable to specify maximum limits on the luminous intensity of warning beacons in directions that are unlikely to be seen by drivers along the roadway, limits which are not included in published performance specifications.

  13. Study of long path VLF signal propagation characteristics as observed from Indian Antarctic station, Maitri

    Science.gov (United States)

    Sasmal, Sudipta; Pal, Sujay; Chakrabarti, Sandip K.

    2014-10-01

    To examine the quality and propagation characteristics of the Very Low Frequency (VLF) radio waves in a very long propagation path, Indian Centre for Space Physics, Kolkata, participated in the 27th Indian scientific expedition to Antarctica during 2007-2008. One Stanford University made AWESOME VLF receiving system was installed at the Indian Antarctic station Maitri and about five weeks of data were recorded successfully from the Indian transmitter VTX and several other transmitting stations worldwide. The quality of the signal from the VTX transmitter was found to be very good, consistent and highly stable in day and night. The signal shows the evidences of the presence of the 24 h solar radiation in the Antarctic region during local summer. Here we report the both narrow band and broadband VLF observations from this site. The diurnal variations of VTX signal (18.2 kHz) are presented systematically for Antarctica path and also compared the same with the variations for a short propagation path (VTX-Kolkata). We compute the spatial distribution of the VTX signal along the VTX-Antarctica path using the most well-known LWPC model for an all-day and all-night propagation conditions. The calculated signal amplitudes corresponding to those conditions relatively corroborate the observations. We also present the attenuation rate of the dominant waveguide modes corresponding to those propagation conditions where the effects of the Antarctic polar ice on the attenuation of different propagating waveguide modes are visible.

  14. Experimental investigation of saturation effect on pump-to-signal intensity modulation transfer in single-pump phase-insensitive fiber optic parametric amplifiers

    DEFF Research Database (Denmark)

    Cristofori, Valentina; Lali-Dastjerdi, Zohreh; Lund-Hansen, Toke

    2013-01-01

    We present an experimental characterization of how signal gain saturation affects the transfer of intensity modulation from the pump to the signal in single-pump, phase-insensitive fiber optic parametric amplifiers (FOPAs). In this work, we demonstrate experimentally for the first time, to our...

  15. Characteristics of the Kind of Intense Convective Systems With Forcing and Dissipation and Its Forecasting

    Institute of Scientific and Technical Information of China (English)

    李志锦; 丑纪范

    1994-01-01

    According to the theory of the nonlinear dynamical systems with forcing and dissipation,theconceptual ideas are proposed that the intense convective system is an attractor of the meso-scale dynamicalsystem,in which the large-scale fields serve as the bifurcation parameters that evolve slowly.The intenseconvective systems occur explosively when the intensity of the large-scale system passes a bifurcation point.Thus,its prediction is just to predict the evolution of the attractor,independent of the mesoscale initial con-ditions.A primitive spectral limited-area model has been developed and two realistic cases,which were cap-tured by the Eastern China area mesoscale experiment,have been simulated by using this model.The resultshave proved the theoretical points.

  16. The characteristics of an intense laser beam propagating in a corrugated plasma channel

    Science.gov (United States)

    Tian, Jian-Min; Tang, Rong-An; Hong, Xue-Ren; Yang, Yang; Wang, Li; Zhou, Wei-Jun; Xue, Ju-Kui

    2016-12-01

    The propagation of an intense laser beam in a corrugated plasma channel is investigated. By using the source-dependent expansion technique, an evolution equation of the laser spot size is derived. The behaviors including aperiodic oscillation, resonance, beat-like wave, and periodic oscillation with multipeak are found and analyzed. The formula for the instantaneous wave numbers of these oscillations is obtained. These theoretical findings are confirmed by the final numerical simulation.

  17. Small signal gain based on analytic models of thin intense electron beams

    Science.gov (United States)

    James Elliott, C.; McVey, Brian; Schmitt, Mark

    1991-07-01

    We develop the free electron laser theory of the effective energy distribution and the small signal gain for a thin electron beam. The assumption of thinness allows us to treat various transverse locations and electron beam trajectory angles as introducing phase shifts that have the same effect as those introduced by a change in energy of the electron. These ideas extend previous work of Colson et al., Dattoli et al., Scharlemann, and others in five important ways. The first is the ability to treat electron beams with three different classes of matching or symmetry conditions: (i) electron beams with separate betatron matching in each plane. (ii) those with aspect ratio matching, and (iii) crossed matched beams. Manifestations of these symmetries include elliptical cross-sections and electron beams that have modulated spatial profiles. For these we derive analytical expressions for effective energy distributions. Second, two emittance parameters for the electron beam are shown to consolidate into a single parameter that describes most of the energy variation of the effective energy distributions. Thus, the effective energy distribution for a 1:4 ribbon electron beam is nearly equivalent to a distribution for a beam of circular cross-section. Third, these calculations extend to energy distributions, angular distributions, and spatial distributions that all follow Gaussian profiles. Fourth, this model incorporates the description of the incident Gaussian optical beam and the above electron beam dynamics into a single influence function kernel. Emittance, energy spread, diffraction, and gain may be interpreted as limiting the length over which the bunching contributions of the propagating electric fields downstream are important. Fifth, three-dimensional profiles of the optical fields are computed. This work is complementary to the recent work of Yu, Krinsky and Gluckstern in that ours always describes the transition from low gain to high gain for a thin beam and not

  18. High Intensity Exercise in Multiple Sclerosis: Effects on Muscle Contractile Characteristics and Exercise Capacity, a Randomised Controlled Trial.

    Directory of Open Access Journals (Sweden)

    Inez Wens

    Full Text Available Low-to-moderate intensity exercise improves muscle contractile properties and endurance capacity in multiple sclerosis (MS. The impact of high intensity exercise remains unknown.Thirty-four MS patients were randomized into a sedentary control group (SED, n = 11 and 2 exercise groups that performed 12 weeks of a high intensity interval (HITR, n = 12 or high intensity continuous cardiovascular training (HCTR, n = 11, both in combination with resistance training. M.vastus lateralis fiber cross sectional area (CSA and proportion, knee-flexor/extensor strength, body composition, maximal endurance capacity and self-reported physical activity levels were assessed before and after 12 weeks.Compared to SED, 12 weeks of high intensity exercise increased mean fiber CSA (HITR: +21 ± 7%, HCTR: +23 ± 5%. Furthermore, fiber type I CSA increased in HCTR (+29 ± 6%, whereas type II (+23 ± 7% and IIa (+23 ± 6%, CSA increased in HITR. Muscle strength improved in HITR and HCTR (between +13 ± 7% and +45 ± 20% and body fat percentage tended to decrease (HITR: -3.9 ± 2.0% and HCTR: -2.5 ± 1.2%. Furthermore, endurance capacity (Wmax +21 ± 4%, time to exhaustion +24 ± 5%, VO2max +17 ± 5% and lean tissue mass (+1.4 ± 0.5% only increased in HITR. Finally self-reported physical activity levels increased 73 ± 19% and 86 ± 27% in HCTR and HITR, respectively.High intensity cardiovascular exercise combined with resistance training was safe, well tolerated and improved muscle contractile characteristics and endurance capacity in MS.ClinicalTrials.gov NCT01845896.

  19. Effects of strain and light intensity on growth performance and carcass characteristics of broilers grown to heavy weights.

    Science.gov (United States)

    Olanrewaju, H A; Miller, W W; Maslin, W R; Collier, S D; Purswell, J L; Branton, S L

    2014-08-01

    Effects of genetic strain and light intensity on growth performance and carcass characteristics of broilers grown to heavy weights were investigated. The experimental design was a randomized complete block design. Treatment structure was a 2 × 5 factorial arrangement with the main factors being strain (Ross × Ross 308, Ross × Ross 708) and light intensity (25, 10, 5, 2.5, and 0.2 lx) with trial as replicates. In each of the 5 trials, chicks of 2 different strains of the same commercial hatchery were equally and randomly distributed into 10 environmentally controlled rooms (5 rooms/strain) at 1 d of age at 50% RH. Each room was randomly assigned 1 of 5 light intensities from 22 to 56 d of age. Feed and water were provided ad libitum. Birds and feed were weighed on 0, 14, 28, 42, and 56 d of age for growth performance. Humoral immune response was determined on d 28, whereas ocular and blood samples were performed on d 42 and 55, respectively. On d 56, 20 (10 males and 10 females) birds/strain from each room were processed to determine weights and yields. Genetic strain was significant (P ≤ 0.05) for most of the examined variables, where Ross × Ross 308 had better growth performance and meat yield in comparison with Ross × Ross 708. Although, there was no main effect of light intensity on growth performance and meat yield, results indicated that birds under 10 and 5 lx intensities showed slightly better growth performance and meat yield compared with birds under 25, 2.5, and 0.2 lx in both strains. There was no effect of strain and light intensity on ocular indices, immune response, plasma corticosterone levels, and mortality. This study shows the positive influence on profits to commercial poultry facilities that are using a low lighting environment to reduce energy cost, optimize feed conversion, and maximize production without compromising the welfare of the broilers.

  20. Influence of illumination intensity on the electrical characteristics and photoresponsivity of the Ag/ZnO Schottky diodes

    Energy Technology Data Exchange (ETDEWEB)

    Zhu, RuiJuan; Zhang, XinAn, E-mail: xinanzhang@henu.edu.cn; Zhao, JunWei; Li, RuoPing; Zhang, WeiFeng

    2015-05-15

    Highlights: • Ag/ZnO Schottky diodes were fabricated. • The electrical parameters of the diodes were obtained and analyzed. • The electrical properties under UV illuminations were discussed. - Abstract: In this article, the ZnO thin films were grown by RF-magnetron sputtering on ITO glass substrates. The Schottky diodes with the configuration of Ag/ZnO/ITO have been fabricated and it has been observed that the diodes exhibit a good rectification. The structural and optical properties of the ZnO films were investigated by X-ray diffractometry and spectrophotometry. The current–voltage (I–V) characteristics of the Ag/ZnO diode were measured under various illuminations. We use the forward bias current–voltage measurements to determine the electrical parameters such as ideality factor, barrier height and series resistance of the diode. The Ag/ZnO Schottky diode exhibits a non-ideal behavior due to the interfacial layer, the interface states and the series resistance. It is found that the barrier height and ideality factor values are strong functions of illumination intensity. The results show that the ideality factor and the barrier height decrease with increasing illumination intensity. The values of R{sub s} obtained from Cheung and Norde methods are decreased with increasing illumination intensity. Photoresponse characteristics of the diode have been analyzed and it is clear that the diode shows a fast response. It is evaluated that the prepared diodes can be used as optoelectronic devices.

  1. Leptomeningeal high signal intensity (ivy sign) on fluid-attenuated inversion-recovery (FLAIR) MR images in moyamoya disease

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, Hirokazu [Department of Diagnostic Radiology, School of Medicine, Keio University, Tokyo 1608582 (Japan)]. E-mail: hirokazu_fujiwara@ybb.ne.jp; Momoshima, Suketaka [Department of Diagnostic Radiology, School of Medicine, Keio University, Tokyo 1608582 (Japan); Kuribayashi, Sachio [Department of Diagnostic Radiology, School of Medicine, Keio University, Tokyo 1608582 (Japan)

    2005-08-01

    Purpose: There are a few reports on leptomeningeal high signal intensity (LMHI: ivy sign) on fluid-attenuated inversion-recovery (FLAIR) images in moyamoya disease, but the feature of this finding has not been completely understood. The purpose of this study was to characterize LMHI on FLAIR images in moyamoya disease and to assess usefulness of this finding in the diagnosis of moyamoya disease in conventional MR imaging. Material and methods: MR imaging of 28 patients with moyamoya disease was retrospectively reviewed. The grade of LMHI on FLAIR images was classified as 'absent,' 'minimal,' 'moderate' and 'marked.' Fifty-four hemispheres of 28 patients (2 patients had unilateral disease) were assessed for the frequency of visualization and distribution of LMHI. The correlations between LMHI on FLAIR images, moyamoya vessels on T1- and T2-weighted images and MR angiography findings were also analyzed. Results: Moderate and marked LMHI was seen in 31 out of 54 hemispheres (57%). LMHI was seen more prominently in the frontal and parietal lobes than in the temporal and occipital lobes. Although there was a tendency for LMHI on FLAIR images to be prominent in groups with moderate and marked moyamoya vessels on T1- and T2-weighted images, there was no significant correlation. More prominent LMHI was observed in the hemispheres in which cortical branches of the middle cerebral arteries were poorly visualized on MR angiography. Conclusion: Leptomeningeal high signal intensity (ivy sign) on FLAIR images is predominantly seen in the frontal and parietal lobes. Because this sign can be seen in patients with unremarkable moyamoya vessels, LMHI is a useful sign in conventional MR imaging for the diagnosis of moyamoya disease.

  2. WNT signaling regulates self-renewal and differentiation of prostate cancer cells with stem cell characteristics

    Institute of Scientific and Technical Information of China (English)

    Isabelle Bisson; David M Prowse

    2009-01-01

    Prostate cancer cells with stem cell characteristics were identified in human prostate cancer cell lines by their abil-ity to form from single cells self-renewing prostaspheres in non-adherent cultures. Prostaspheres exhibited heteroge-neous expression of proliferation, differentiation and stem cell-associated makers CD44, ABCG2 and CD133. Treat-ment with WNT inhibitors reduced both prostasphere size and self-renewal, In contrast, addition of Wnt3a caused increased prostasphere size and self-renewal, which was associated with a significant increase in nuclear β-catenin, keratin 18, CD133 and CD44 expression. As a high proportion of LNCaP and C4-2B cancer cells express androgen receptor we determined the effect of the androgen receptor antagonist bicalutamide. Androgen receptor inhibition reduced prostasphere size and expression of PSA, but did not inhibit prostasphere formation. These effects are con-sistent with the androgen-independent self-renewal of cells with stem cell characteristics and the androgen-dependent proliferation of transit amplifying cells. As the canonical WNT signaling effector β-catenin can also associate with the androgen receptor, we propose a model for tumour propagation involving a balance between WNT and androgen re-ceptor activity. That would affect the self-renewal of a cancer cell with stem cell characteristics and drive transit am-plifying cell proliferation and differentiation. In conclusion, we provide evidence that WNT activity regulates the self-renewal of prostate cancer cells with stem cell characteristics independently of androgen receptor activity. Inhibition of WNT signaling therefore has the potential to reduce the self-renewal of prostate cancer cells with stem cell charac-teristics and improve the therapeutic outcome.

  3. Evaluation of the Relationship Between Relative Signal Intensity of Magnetic Resonance Images of Retrodiscal Tissue and Lateral Ptrygoid Muscle and Magnetic Resonance Imaging Findings

    Directory of Open Access Journals (Sweden)

    Hoda Banihashemi

    2012-09-01

    Full Text Available Background and Aims: Disc displacement is the most common temporomandibular joint disorder and magnetic resonance imaging (MRI is the gold standard in its diagnosis. This disorder can lead to changes in signal intensity of magnetic resonance (MR. The purpose of this study was evaluation of correlation between relative signal intensity of MR images of retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle with type of anterior disk displacement and condylar head flattening in patients with temporomandibular disorder (TMD. Materials and Methods: In this retrospective study, 31 MR images of patients who had anterior disc displacement were evaluated. After relative signal intensity measurement for retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle, the correlation between relative signal intensity and type of anterior disc displacement was evaluated with repeated measure ANOVA test. In each of these 3 areas, t-test was used to compare the groups with and without condylar head flattening. Results: The correlation between relative signal intensity of MR images and type of anterior disc displacement in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle was not significant. There was also no statistically significant correlation between relative signal intensity of MR images and flattening of condylar head in retrodiscal tissue, superior and inferior head of lateral ptrygoid muscle (P>0.05. Conclusion: According to findings of this study, relative signal intensity of MR images in retrodiscal tissue, superior and inferior head of ptrygoid muscle is not a good predictor for type of anterior disc displacement and flattening of condylar head. It seems that this cannot be used as a diagnostic marker for TMD progression.

  4. The effect of increased T2 signal intensity in the spinal cord on the injury severity and early neurological recovery in patients with central cord syndrome.

    Science.gov (United States)

    Schroeder, Gregory D; Hjelm, Nik; Vaccaro, Alexander R; Weinstein, Michael S; Kepler, Christopher K

    2016-05-01

    OBJECTIVE The aim of this paper was to compare the severity of the initial neurological injury as well as the early changes in the American Spinal Injury Association (ASIA) motor score (AMS) between central cord syndrome (CCS) patients with and without an increased T2 signal intensity in their spinal cord. METHODS Patients with CCS were identified and stratified based on the presence of increased T2 signal intensity in their spinal cord. The severity of the initial neurological injury and the progression of the neurological injury over the 1st week were measured according to the patient's AMS. The effect of age, sex, congenital stenosis, surgery within 24 hours, and surgery in the initial hospitalization on the change in AMS was determined using an analysis of variance. RESULTS Patients with increased signal intensity had a more severe initial neurological injury (AMS 57.6 vs 75.3, respectively, p = 0.01). However, the change in AMS over the 1st week was less severe in patients with an increase in T2 signal intensity (-0.85 vs -4.3, p = 0.07). Analysis of variance did not find that age, sex, Injury Severity Score, congenital stenosis, surgery within 24 hours, or surgery during the initial hospitalization affected the change in AMS. CONCLUSIONS The neurological injury is different between patients with and without an increased T2 signal intensity. Patients with an increased T2 signal intensity are likely to have a more severe initial neurological deficit but will have relatively minimal early neurological deterioration. Comparatively, patients without an increase in the T2 signal intensity will likely have a less severe initial injury but can expect to have a slight decline in neurological function in the 1st week.

  5. Technological and environmental characteristics of intensive care units. Implications for job redesign.

    Science.gov (United States)

    Mark, B A; Hagenmueller, A C

    1994-04-01

    Nurse executives are experiencing severe pressures to create systems of care delivery that provide services in more cost-conscious ways. Before care systems can be restructured, a systematic assessment of the work and the environment of the nursing unit must take place. This study found significant differences among nine intensive care units regarding both the nature of their work and their environments. These differences provided information that can be used in staffing decisions, nurse/physician interaction, and staff nurse and managerial recruitment.

  6. Thermodynamic Characteristics of Tropical Cyclones with RapidIntensity Change over the Coastal Waters of China

    Institute of Scientific and Technical Information of China (English)

    于玉斌; 姚秀萍

    2011-01-01

    In order to investigate the different thermodynamic mechanisms between rapid intensifying (RI) and rapid weakening (RW) tropical cyclones (TCs),the thermodynamic structures of two sets of composite TCs are analyzed based on the complete-form vertical vorticity tendency equation and the NCEP/NCAR reanalysis data.Each composite is composed of five TCs,whose intensities change rapidly over the coastal waters of China.The results show that the maximum apparent heating source Q1 exists in both the upper and lower troposphere near the RI TC center,and Q1 gets stronger at the lower level during the TC intensification period.But for the RW TC,the maximum Q1 exists at the middle level near the TC center,and Q1 gets weaker while the TC weakens.The maximum apparent moisture sink Q2 lies in the mid troposphere.Q2 becomes stronger and its peak-value height rises while TC intensifies,and vice versa.The increase of diabatic heating with height near the TC center in the mid-upper troposphere and the increase of vertical inhomogeneous heating near the TC center in the lower troposphere are both favorable to the TCs' rapid intensification; otherwise,the intensity of the TC decreases rapidly.

  7. Spatial and temporal characteristics of rain intensity in the peninsular Malaysia using TRMM rain rate

    Science.gov (United States)

    Varikoden, Hamza; Samah, A. A.; Babu, C. A.

    2010-06-01

    SummaryThe present study is focused on the intensity distribution of rainfall in different classes and their contribution to the total seasonal rainfall. In addition, we studied the spatial and diurnal variation of the rainfall in the study areas. For the present study, we retrieved data from TRMM (Tropical Rain Measuring Mission) rain rate available in every 3 h temporal and 25 km spatial resolutions. Moreover, station rainfall data is used to validate the TRMM rain rate and found significant correlation between them (linear correlation coefficients are 0.96, 0.85, 0.75 and 0.63 for the stations Kota Bharu, Senai, Cameron highlands and KLIA, respectively). We selected four areas in the Peninsular Malaysia and they are south coastal, east coastal, west coastal and highland regions. Diurnal variation of frequency of rain occurrence is different for different locations. We noticed bimodal variation in the coastal areas in most of the seasons and unimodal variation in the highland/inland area. During the southwest monsoon period in the west coastal stations, there is no distinct diurnal variation. The distribution of different intensity classes during different seasons are explained in detail in the results.

  8. Predictors of surgical outcome in thoracic ossification of the ligamentum flavum: focusing on the quantitative signal intensity

    Science.gov (United States)

    Zhang, JingTao; Wang, LinFeng; Li, Jie; Yang, Peng; Shen, Yong

    2016-01-01

    The association between intramedullary increased signal intensity (ISI) on T2-weighted magnetic resonance imaging (MRI) and surgical outcome in thoracic ossification of the ligamentum flavum (OLF) remains controversial. We aimed to determine the impact of signal change ratio (SCR) on thoracic OLF surgical outcomes. We retrospectively reviewed 96 cases of thoracic OLF surgery and investigated myelopathy severity, symptom duration, MRI and computed tomographic findings, surgical technique and postoperative recoveries. Surgical outcomes were evaluated according to the modified Japanese Orthopaedic Association (JOA) score and recovery rate. JOA recovery rate factors associated with surgical outcomes. Forty patients (41.7%) had a recovery rate of SCR cutoff value as a predictor of poor surgical outcome was 1.54. Multivariate logistic regression analysis revealed that a preoperative SCR ≥1.54 and symptom duration >12 months were significant risk factors for a poor surgical outcome. These findings suggest that preoperative SCR and duration of symptoms were significant risk factors of surgical outcome for patients with thoracic OLF. Patients with preoperative SCR ≥1.54 can experience poor postoperative recovery. PMID:26960572

  9. Evolution of Volume and Signal Intensity on Fluid-attenuated Inversion Recovery MR Images after Endovascular Stroke Therapy.

    Science.gov (United States)

    Federau, Christian; Mlynash, Michael; Christensen, Soren; Zaharchuk, Greg; Cha, Brannon; Lansberg, Maarten G; Wintermark, Max; Albers, Gregory W

    2016-07-01

    Purpose To analyze both volume and signal evolution on magnetic resonance (MR) fluid-attenuated inversion recovery (FLAIR) images between the images after endovascular therapy and day 5 (which was the prespecified end point for infarct volume in the Diffusion and Perfusion Imaging Evaluation for Understanding Stroke Evolution [DEFUSE 2] trial) in a subset of patients enrolled in the DEFUSE 2 study. Materials and Methods This study was approved by the local ethics committee at all participating sites. Informed written consent was obtained from all patients. In this post hoc analysis of the DEFUSE 2 study, 35 patients with FLAIR images acquired both after endovascular therapy (median time after symptom onset, 12 hours) and at day 5 were identified. Patients were separated into two groups based on the degree of reperfusion achieved on time to maximum greater than 6-second perfusion imaging (≥90% vs <90%). After coregistration and signal normalization, lesion volumes and signal intensity were assessed by using FLAIR imaging for the initial lesion (ie, visible after endovascular therapy) and the recruited lesion (the additional lesion visible on day 5, but not visible after endovascular therapy). Statistical significance was assessed by using Wilcoxon signed-rank, Mann-Whitney U, and Fisher exact tests. Results All 35 patients had FLAIR lesion growth between the after-revascularization examination and day 5. Median lesion growth was significantly larger in patients with <90% reperfusion (27.85 mL) compared with ≥90% (8.12 mL; P = .003). In the initial lesion, normalized signal did not change between after endovascular therapy (median, 1.60) and day 5 (median, 1.58) in the ≥90% reperfusion group (P = .97), but increased in the <90% reperfusion group (from 1.60 to 1.73; P = .01). In the recruited lesion, median normalized signal increased significantly in both groups between after endovascular therapy and day 5 (after endovascular therapy, from 1.19 to 1.56, P

  10. Characteristics and outcome of stroke patients with cerebrovascular accident at the intensive care unit of a tertiary hospital in Nigeria.

    Science.gov (United States)

    Tobi, Ku; Okojie, Nq

    2013-01-01

    Patients with severe stroke defined as NIHSS score >17 constituting about 15-20% of cerebrovascular accident require admission into the Intensive Care Unit (ICU). However the benefit of ICU admission for stroke patients remains controversial. Aim & Objectives: To determine the characteristics and outcome of patients with cerebrovascular accident managed at the Intensive Care Unit of University of Benin Teaching Hospital. Demographic characteristics, clinical features and course, treatment options and outcome of all stroke patients admitted in ICU from January 2002 to January 2012 were retrieved from the hospital records and analyzed. A patient before and after each stroke patient were selected as controls for the study. Primary outcome variable was ICU mortality, type of stroke whether ischemic or haemorrhagic, duration of stay, whether patients were transferred from the medical/stroke ward or from the accident and emergency department of the hospital. A total of thirty six (36) stroke patients were admitted into the ICU within the study period accounting for 5.6% of the total ICU admissions. The male: female ratio is 2:1 and patients aged >60 years accounted for 55.6%. Stroke patients admitted into ICU had a mortality rate of 77.8%. Patients with severe stroke admitted into the ICU were 4 times more likely to die compared to non-stroke patients in the ICU (p=0.002, OR=4.472). However, severe stroke had no significant impact on duration of ICU stay (p=0.454, OR=1.464). Stroke patients have a high mortality in the intensive care unit that is independent on the type and route of admission. Provision of the support equipment and instruments required for high dependency service in the intensive care unit and early admission should improve the outcome.

  11. Effect of illumination intensity and temperature on the I-V characteristics of n-C/p-Si heterojunction

    Energy Technology Data Exchange (ETDEWEB)

    Gupta, Babita; Shishodia, P.K.; Kapoor, A.; Mehra, R.M. [Department of Electronic Science, University of Delhi South Campus, Benito Juarez Road, 110021 New Delhi (India); Soga, Tetsuo; Jimbo, Takashi [Department of Environmental Technology and Urban Planning, Nagoya Institute of Technology, 466-8555 Nagoya (Japan); Umeno, Masayoshi [Research Center for Microstructure Devices, Nagoya Institute of Technology, 466-8555 Nagoya (Japan)

    2002-07-01

    Krishna et al. (Sol. Energy Mater. Sol. Cells 65 (2001) 163) have recently developed an heterojunction n-C/p-Si in order to achieve low cost and high-efficiency carbon solar cell. It has been shown that for this structure, the maximum quantum efficiency (25%) appears at wavelength {lambda} (600nm). In this paper, the dependence of I-V characteristics of this heterojunction solar cell on illumination intensity and temperature has been systematically investigated. An estimation of the stability of the solar cell with temperature has been made in terms of the temperature coefficient of I{sub sc} and V{sub oc}. The intensity variation study has been used to estimate the series resistance R{sub s} of the solar cell. The effect of illumination intensity on I-V of n-C/p-Si heterojunction is more complex because the carrier lifetime and the carrier mobility of amorphous carbon are small and also because drift of carriers by built-in electric field plays an important role in these cells. Therefore, the conventional analytical expression for I-V characteristic is not applicable to such solar cells. These structures will not obey the principle of superposition of illuminated and dark current. The experimental results have been analysed by developing empirical relation for I-V.The temperature sensitivity parameters {alpha}, the change in I{sub sc} and {beta}, the change in V{sub oc} per degree centigrade have been computed and are found to be 0.087mA/C and 1mV/C, respectively. This suggests that the heterojunction n-C/p-Si has good temperature tolerance. The value of series resistance has been estimated from the family of I-V curves at various intensities. The R{sub s} is found to be {approx}12{omega}, which is on the higher side from the point of view of photovoltaic application.

  12. The frequency characteristic of chaotic synchronization systems and weak signal detection

    Institute of Scientific and Technical Information of China (English)

    裴留庆; 匡锦瑜; 邵媛

    1997-01-01

    A concept of frequency character of a chaotic synchronized system (CHSS) is proposed. The nature of the system can be described in the frequency domain with the concept. A simple model to measure the frequency character is designed, and the characteristic curve of Chua’s CHSS is obtained. Some results from theoretical analysis and numerical simulation indicate that the system possesses multiband of frequencies with distinct features shown in each band. Thus it may offer various resources of frequencies, fn particular, it is capable of detecting weak signals drowned in noise in some bands. Both the concept of frequency character and the characteristic curve of CHSS provide a scientific basis for us to gain a deeper insight into the inherent function of information processing in CHSS, and to utilize properly the information resources of CHSS as well.

  13. Research progress of laser welding process dynamic monitoring technology based on plasma characteristics signal

    Directory of Open Access Journals (Sweden)

    Teng WANG

    2017-02-01

    Full Text Available During the high-power laser welding process, plasmas are induced by the evaporation of metal under laser radiation, which can affect the coupling of laser energy and the workpiece, and ultimately impact on the reliability of laser welding quality and process directly. The research of laser-induced plasma is a focus in high-power deep penetration welding field, which provides a promising research area for realizing the automation of welding process quality inspection. In recent years, the research of laser welding process dynamic monitoring technology based on plasma characteristics is mainly in two aspects, namely the research of plasma signal detection and the research of laser welding process modeling. The laser-induced plasma in the laser welding is introduced, and the related research of laser welding process dynamic monitoring technology based on plasma characteristics at home and abroad is analyzed. The current problems in the field are summarized, and the future development trend is put forward.

  14. Modulation Depth Based on Frequency-shift Characteristic of LiNbO3 Waveguide Electro-optic Intensity Modulator

    Institute of Scientific and Technical Information of China (English)

    Hui-juan ZHOU; Zhou MENG; Yi LIAO

    2010-01-01

    The modulation depth,defined according to practical mod-ulation results,which changes with the microwave power and its fre-quency,is significant for systems utilizing the frequency-shift charac-teristic of the LiNbO3 waveguide Electro-Optic Intensity Modulator (EOIM).By analyzing the impedance mismatch between the micro-wave source and the EOIM,the effective voltage applied to the RF port of the EOIM is deprived frcm the microwave power and its fre-quency.Associating with analyses of the phase velocity mismatch be-tween the microwave and the optical wave,the theoretical modulation depth has been obtained,which is verified by experimental results.We provide a method to choose the appropriate modulation depth to optimize the desired sideband through proper transmission bias far the system based an the frequency-shift characteristic of the EOIM.

  15. A Comparison of Natural and Urban Characteristics and the Development of Urban Intensity Indices Across Six Geographic Settings

    Science.gov (United States)

    Falcone, James A.; Stewart, Jana; Sobieszczyk, Steven; Dupree, Jean; McMahon, Gerard; Buell, Gary

    2007-01-01

    As part of the U.S. Geological Survey National Water-Quality Assessment Program, the effects of urbanization on stream ecosystems have been intensively investigated in six metropolitan areas in the United States. Approximately 30 watersheds in each area, ranging in size from 4 to 560 square kilometers (median is 50 square kilometers), and spanning a development gradient from very low to very high urbanization, were examined near Atlanta, Georgia; Raleigh, North Carolina; Denver, Colorado; Dallas-Fort Worth, Texas; Portland, Oregon; and Milwaukee-Green Bay, Wisconsin. These six studies are a continuation of three previous studies in Boston, Massachusetts; Birmingham, Alabama; and Salt Lake City, Utah. In each study, geographic information system data for approximately 300 variables were assembled to (a) characterize the environmental settings of the areas and (b) establish a consistent multimetric urban intensity index based on locally important land-cover, infrastructure, and socioeconomic variables. This paper describes the key features of urbanization and the urban intensity index for the study watersheds within each area, how they differ across study areas, and the relation between the environmental setting and the characteristics of urbanization. A number of features of urbanization were identified that correlated very strongly to population density in every study area. Of these, road density had the least variability across diverse geographic settings and most closely matched the multimetric nature of the urban intensity index. A common urban intensity index was derived that ranks watersheds across all six study areas. Differences in local natural settings and urban geography were challenging in (a) identifying consistent urban gradients in individual study areas and (b) creating a common urban intensity index that matched the site scores of the local urban intensity index in all areas. It is intended that the descriptions of the similarities and differences

  16. Characteristics and mortality of elderly patients admitted to the Intensive Care Unit of a district hospital

    Directory of Open Access Journals (Sweden)

    José Carlos Llamas Reyes

    2016-01-01

    Full Text Available Aim: To study all the elderly patients (≥75 years who were admitted in an Intensive Care Unit (ICU of a Spanish hospital and identify factors associated with mortality. Patients and Methods: A retrospective, observational data collected prospectively in patients ≥75 years recruited from the ICU in the period of January 2004 to December 2010. Results: During the study period, 1661 patients were admitted to our unit, of whom 553 (33.3% were older than 75 years. The mean age was 79.9 years, 317 (57.3% were male, and the overall in-hospital mortality was 94 patients (17% confidence interval 14-20.3%. When comparing patients who survived to those who died, we found significant differences in mean age (P = 0.001, Acute Physiologic Assessment and Chronic Health Evaluation II and Simplified Acute Physiology Scoring II (SAPS II on admission (P 75 years was not significant (P = 0.1390. Conclusions: The percentage of elderly patients in our unit is high, with low mortality rates. The age itself is not the sole determinant for admission to the ICU and other factors should be taken into account.

  17. Chaotic dynamic characteristics of pressure fluctuation signals in hydro-turbine

    Energy Technology Data Exchange (ETDEWEB)

    Su, Wen Tao; An, Shi [School of Management, Harbin Institute of Technology, Harbin (China); Li, Xiao Bin; Lan, Chao Feng; Li, Feng Chen [School of Energy Science and Engineering, Harbin Institute of Technology, Harbin (China); Wang, Jian Sheng [Ministry of Education of China, Tianjin (China)

    2016-11-15

    The pressure fluctuation characteristics in a Francis hydro-turbine running at partial flow conditions were studied based on the chaotic dynamic methods. Firstly, the experimental data of pressure fluctuations in the draft tube at various flow conditions was de-noised using lifting wavelet transformation, then, for the de-noised signals, their spectrum distribution on the frequency domain, the energy variation and the energy partition accounting for the total energy was calculated. Hereby, for the flow conditions ranging from no cavitation to severe cavitation, the chaos dynamic features of fluctuation signals were analyzed, including the temporal-frequency distribution, phase trajectory, Lyapunov exponent and Poincaré map etc. It is revealed that, the main energy of pressure fluctuations in the draft tube locates at low-frequency region. As the cavitation grows, the amplitude of power spectrum at frequency domain becomes larger. For all the flow conditions, all the maximal Lyapunov exponents are larger than zero, and they increase with the cavitation level. Therefore, it is believed that there indeed exist the chaotic attractors in the pressure fluctuation signals for a hydro-turbine.

  18. [Effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash].

    Science.gov (United States)

    Du, She-ni; Bai, Gang-shuan; Liang, Yin-li

    2011-04-01

    A pot experiment with artificial shading was conducted to study the effects of soil moisture content and light intensity on the plant growth and leaf physiological characteristics of squash variety "Jingyingyihao". Under all test soil moisture conditions, 30% shading promoted the growth of "Jingyingyihao", with the highest yield at 70% - 80% soil relative moisture contents. 70% shading inhibited plant growth severely, only flowering and not bearing fruits, no economic yield produced. In all treatments, there was a similar water consumption trend, i. e., both the daily and the total water consumption decreased with increasing shading and decreasing soil moisture content. Among all treatments, 30% shading and 70% - 80% soil relative moisture contents had the highest water use efficiency (2.36 kg mm(-1) hm(-2)) and water output rate (1.57 kg mm(-1) hm(-2)). The net photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll content of squash leaves decreased with increasing shading, whereas the intercellular CO2 concentration was in adverse. The leaf protective enzyme activity and proline content decreased with increasing shading, and the leaf MAD content decreased in the order of 70% shading, natural radiation, and 30% shading. Under the three light intensities, the change characteristics of squash leaf photosynthesis, protective enzyme activity, and proline and MAD contents differed with the increase of soil relative moisture content.

  19. Intense heat waves: dynamical-physical factors and characteristics of these heat waves

    Directory of Open Access Journals (Sweden)

    Meral Demirtaş

    2017-04-01

    Full Text Available Dynamical and physical factors that trigger and maintain heat waves (HW were examined. Since high pressure systems play a role in HW processes, an atmospheric blocking method was introduced. A HW detection method which employs spatially and temporally changing reference temperature to compute HW parameters was used. Departures from climate averages of 500-hPa geopotential height, 850-hPa temperature, sea-surface-temperatures and soil wetness of 2003, 2012 and 2015 June-July-August were analyzed. HWs were examined together with dynamical and physical factors, atmospheric blocking and HW characteristics. Results indicate that HWs were influential over the Aegean region. Year-to-year variability in summer temperatures is considered as signs of climate variability.

  20. Clinical Characteristics and Prognosis of Peri-strut Low-intensity Area Detected by Optical Coherence Tomography

    Institute of Scientific and Technical Information of China (English)

    De-Wei Wu; Meng-Yue Yu; Hai-Yang Gao; Zhe He; Jing Yao; Cheng Ding; Bo Xu

    2015-01-01

    Background: Peri-strut low-intensity area (PLIA) is a typical image pattern ofneointima detected by optical coherence tomography (OCT) after stent implantation.However, few studies evaluated the predictors and prognosis of the PLIA;therefore, we aimed to explore the genesis and prognosis of PLIA detected by OCT in this study.Methods: Patients presenting neointimal hyperplasia documented by OCT reexamination after percutaneous coronary intervention were prospectively included from 2009 to 2011.Peri-strut intensity was analyzed and classified into two patterns: Low-intensity and high-intensity.Clinical characteristics were analyzed to assess their contribution to peri-strut intensity patterns.Follow-up were performed in patients who did not receive revascularization during OCT reexamination, and the prognosis of the patients was evaluated.Results: There were 128 patients underwent OCT reexamination after stent implantation included in the study.PLIA was detected in 22 (17.2%) patients.The incidence of PLIA was positively correlated with serum triglyceride (odds ratio [OR]: 2.11, 95% confidence interval [CI]: 1.14-3.90, P =0.017), low-density lipoprotein (OR: 2.61, 95% CI: 1.22-5.66, P =0.015), history of cerebrovascular disease (OR: 101.11, 95% CI: 6.54-1562.13, P < 0.001), and initial clinical presentation of acute coronary syndrome (ACS, OR: 18.77, 95% CI: 2.73-128.83, P =0.003) while negatively correlated with stent implantation time (OR: 0.57, 95% CI: 0.33-0.98, P =0.043).The median follow-up was longer than 3.8 years.Major adverse cardiovascular events (MACEs) occurred in 7 (7.3%) patients while showed no correlation with PLIA.A total of 17 (17.7%) patients experienced unstable angina (UA) and showed significant correlation with PLIA (hazard ratio: 6.16, 95% CI: 1.25-30.33, P =0.025).Conclusions: PLIA detected by OCT was positively correlated with higher serum lipid level, history of cerebrovascular disease and initial presentation of ACS

  1. Characteristics of upstream energetic (E>=50keV) ion events during intense geomagnetic activity

    Science.gov (United States)

    Anagnostopoulos, G. C.; Rigas, A. G.; Sarris, E. T.; Krimigis, S. M.

    1998-05-01

    In this work we examine the statistical presence of some important features of upstream energetic (>=50 keV) ion events under some special conditions in the upstream region and the magnetosphere. The 125 ion events considered in the statistic were observed by the IMP 7 and IMP 8 spacecraft, at ~35RE from the Earth, during nine long time intervals of a total of 153 hours. The time intervals analyzed were selected under the following restrictions: existence of high proton flux (i.e., >=900 pcm-2s-1sr-1) and of a great number of events (an occurrence frequency of ~10 events per 12 hours in the whole statistics) in the energy range 50-220 keV. The most striking findings are the following: (1) The upstream events were observed during times with high values of the geomagnetic activity index Kp(>=3-) (2) all of the upstream events (100%) have energy spectra extending up to energies E>=290keV (3) 86% of these events are accompanied by relativistic (E>=220keV) electrons; and (4) the majority of the upstream ion events (82%) showed noninverse velocity dispersion during their onset phase (22% of the events showed forward velocity dispersion, and 60% showed no velocity dispersion at all when 5.5-min averaged observations were analyzed). Further statistical analysis of this sample of upstream particle events shows that the 50- to 220-keV proton flux shows a positive correlation with the following parameters: the Kp index of geomagnetic activity and the flux of the high-energy (290-500 keV) protons and (>=220 keV) electrons. More specific findings are the following: (1) The spectral index γ for a power law distribution of ions detected by the National Oceanic and Atmospheric Administration Energetic Particle Experiment (EPE) instrument (50=220-keV electrons increases with the time duration of upstream events. We infer that the vast majority of the upstream ion events considered in this study (under conditions of intense particle activity in the upstream region and enhanced

  2. Increase of SERS Signal Upon Heating or Exposure to a High-Intensity Laser Field: Benzenethiol on an AgFON Substrate

    CERN Document Server

    Aggarwal, Roshan L; Saikin, Semion K

    2012-01-01

    The surface-enhanced Raman scattering (SERS) signal from an AgFON plasmonic substrate, recoated with benzenethiol, was observed to increase by about 100% upon heating for 3.5 min at 100C and 1.5 min at 125C. The signal intensity was found to increase further by about 80% upon a 10 sec exposure to a high-intensity (3.2 kW/cm^2) 785-nm cw laser, corresponding to 40 mW in a 40+/-5-um diameter spot. The observed increase in the SERS signal may be understood by considering the presence of benzenethiol molecules in an intermediate or 'precursor' state in addition to conventionally ordered molecules forming a self-assembled monolayer. The increase in the SERS signal arises from the conversion of the molecules in the precursor state to the chemisorbed state due to thermal and photo-thermal effects.

  3. Prognosis prediction of non-enhancing T2 high signal intensity lesions in glioblastoma patients after standard treatment: application of dynamic contrast-enhanced MR imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Rihyeon; Yun, Tae Jin; Kim, Ji-Hoon; Sohn, Chul-Ho [Seoul National University Hospital, Department of Radiology, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Choi, Seung Hong [Seoul National University Hospital, Department of Radiology, 101 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University Medical Research Center, Department of Radiology, Seoul National University College of Medicine, and Institute of Radiation Medicine, 103 Daehak-ro, Jongno-gu, Seoul (Korea, Republic of); Seoul National University, Center for Nanoparticle Research, Institute for Basic Science (IBS), Daehak-dong, Gwanak-gu, Seoul (Korea, Republic of); Seoul National University, School of Chemical and Biological Engineering, Daehak-dong, Gwanak-gu, Seoul (Korea, Republic of); Lee, Soon-Tae [Seoul National University Hospital, Department of Neurology, Seoul (Korea, Republic of); Park, Chul-Kee [Seoul National University Hospital, Department of Neurosurgery, Seoul (Korea, Republic of); Kim, Tae Min [Seoul National University Hospital, Department of Internal Medicine, Seoul (Korea, Republic of); Park, Sun-Won [Seoul National University College of Medicine, Department of Radiology, SMG-SNU Boramae Medical Center, Seoul (Korea, Republic of); Park, Sung-Hye [Seoul National University Hospital, Department of Pathology, Seoul (Korea, Republic of); Kim, Il Han [Seoul National University Hospital, Department of Radiation Oncology, Seoul (Korea, Republic of)

    2017-03-15

    To identify candidate imaging biomarkers for early disease progression in glioblastoma multiforme (GBM) patients by analysis of dynamic contrast-enhanced (DCE) MR parameters of non-enhancing T2 high signal intensity (SI) lesions. Forty-nine GBM patients who had undergone preoperative DCE MR imaging and received standard treatment were retrospectively included. According to the Response Assessment in Neuro-Oncology criteria, patients were classified into progression (n = 21) or non-progression (n = 28) groups. We analysed the pharmacokinetic parameters of Ktrans, Ve and Vp within non-enhancing T2 high SI lesions of each tumour. The best percentiles of each parameter from cumulative histograms were identified by the area under the receiver operating characteristic curve (AUC) and were compared using multivariate stepwise logistic regression. For the differentiation of early disease progression, the highest AUC values were found in the 99th percentile of Ktrans (AUC 0.954), the 97th percentile of Ve (AUC 0.815) and the 94th percentile of Vp (AUC 0.786) (all p < 0.05). The 99th percentile of Ktrans was the only significant independent variable from the multivariate stepwise logistic regression (p = 0.002). We found that the Ktrans of non-enhancing T2 high SI lesions in GBM patients holds potential as a candidate prognostic marker in future prospective studies. (orig.)

  4. Characteristics and natural course of vertebral endplate signal (Modic changes in the Danish general population

    Directory of Open Access Journals (Sweden)

    Sorensen Joan S

    2009-07-01

    Full Text Available Abstract Background Vertebral endplate signal changes (VESC are more common among patients with low back pain (LBP and/or sciatica than in people who are not seeking care for back pain. The distribution and characteristics of VESC have been described in people from clinical and non-clinical populations. However, while the clinical course of VESC has been studied in patients, the natural course in the general population has not been reported. The objectives of this prospective observational study were to describe: 1 the distribution and characteristics of VESC in the lumbar spine, 2 its association with disc degeneration, and 3 its natural course from 40 to 44 years of age. Methods Three-hundred-and-forty-four individuals (161 men and 183 women sampled from the Danish general population had MRI at the age of 40 and again at the age of 44. The following MRI findings were evaluated using standardised evaluation protocols: type, location, and size of VESC, disc signal, and disc height. Characteristics and distribution of VESC were analysed by frequency tables. The association between VESC and disc degeneration was analysed by logistic regression analysis. The change in type and size of VESC was analysed by cross-tabulations of variables obtained at age 40 and 44 and tested using McNemar's test of symmetry. Results Two-thirds (67% of VESC found in this study were located in the lower part of the spine (L4-S1. VESC located at disc levels L1-L3 were generally small and located only in the anterior part of the vertebra, whereas those located at disc levels L4-S1 were more likely to extend further into the vertebra and along the endplate. Moreover, the more the VESC extended into the vertebra, the more likely it was that the adjacent disc was degenerated. The prevalence of endplate levels with VESC increased significantly from 6% to 9% from age 40 to 44. Again, VESC that was only observed in the endplate was more likely to come and go over the four

  5. Light Intensity Affects Chlorophyll Synthesis During Greening Process by Metabolite Signal from Mitochondrial Alternative Oxidase in Arabidopsis

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Dawei; YUAN; Shu; 徐飞; ZHU; Feng; YUAN; Ming; YE; Huaxun; GUO; Hongqing; LV; Xin; YIN; Yanhai; 林宏辉

    2015-01-01

    Although mitochondrial alternative oxidase(AOX)has been proposed to play essential roles in high light stress tolerance,the effects of AOX on chlorophyll synthesis are unclear.Previous studies indicated that during greening,chlorophyll accumulation was largely delayed in plants whose mitochondrial cyanide-resistant respiration was inhibited by knocking out nuclear encoded AOX gene.Here we show that this delay of chlorophyll accumulation was more significant under high light condition.Inhibition of cyanide-resistant respiration was also accompanied by the increase of plastid NADPH/NADP~+ratio,especially under high light treatment which subsequently blocked the import of multiple plastidial proteins,such as some components of the photosynthetic electron transport chain,the Calvin-Benson cycle enzymes and malate/oxaloacetate shuttle components.Over expression of AOXla rescued the aoxla mutant phenotype,including the chlorophyll accumulation during greening and plastidial protein import.It thus suggests that light intensity affects chlorophyll synthesis during greening process by a metabolic signal,the AOX-derived plastidial NADPH/NADP~+ratio change.And our results thus revealed a molecular mechanism of chloroplast-mitochondria interactions.

  6. Clinical Implications of Diffuse Excessive High Signal Intensity (DEHSI on Neonatal MRI in School Age Children Born Extremely Preterm.

    Directory of Open Access Journals (Sweden)

    Lina Broström

    Full Text Available Magnetic resonance imaging (MRI of the brain carried out during the neonatal period shows that 55-80% of extremely preterm infants display white matter diffuse excessive high signal intensity (DEHSI. Our aim was to study differences in developmental outcome at the age of 6.5 years in children born extremely preterm with and without DEHSI.This was a prospective cohort study of 83 children who were born in Stockholm, Sweden, between 2004 and 2007, born at gestational age of < 27 weeks + 0 days and who underwent an MRI scan of their brain at term equivalent age. The outcome measures at 6.5 years included testing 66 children with the modified Touwen neurology examination, the Movement Assessment Battery for Children 2, the Wechsler Intelligence Scale for Children-Fourth Edition, Beery Visual-motor Integration test-Sixth Edition, and the Strengths and Difficulties Questionnaire. Group-wise comparisons were done between children with and without DEHSI using Student t-test, Mann Whitney U test, Chi square test and regression analysis.DEHSI was detected in 39 (59% of the 66 children who were assessed at 6.5 years. The presence of DEHSI was not associated with mild neurological dysfunction, scores on M-ABC assessment, cognition, visual-motor integration, or behavior at 6.5 years.The presence of qualitatively defined DEHSI on neonatal MRI did not prove to be a useful predictor of long-term impairment in children born extremely preterm.

  7. Variations in programmed phase defect size and its impact on defect detection signal intensity using at-wavelength inspection system

    Science.gov (United States)

    Amano, Tsuyoshi; Takagi, Noriaki; Abe, Tsukasa

    2015-10-01

    A programmed phase defect Extreme Ultraviolet (EUV) mask was fabricated and measurement repeatability of the defect size using a scanning probe microscope (SPM) was evaluated. The SPM measurement results indicated that the defect size variation as registered by the measurement repeatability were much smaller than the defect-to-defect variations. It means the defect-to-defect variation in size actually does exist. Some defects were found where their sizes before a multilayer coating (on quartz) were all the same but after the coat their sizes varied quite significantly when observed on the multilayer. This result indicated that it is difficult to estimate the phase defect size on quartz, whereas they can be accurately measured on multilayer. Influences of the defect size variation on defect detection signal intensity (DSI) using an actinic blank inspection (ABI) system were examined; their influences on the wafer printability were also examined. The DSI was strongly correlated with defect depth on the multilayer, and it was also indicated that the ABI can detect small variations in defect sizes. It was also confirmed that the impact of the phase defects on wafer printed CDs were proportional to the DSIs, and that the ABI has a potential to detect phase defect that could cause 5 % of the CD error when printing 16 nm dense lines.

  8. Signal intensity changes of the fetal liver on MRI in-phase and out-of-phase sequence.

    Science.gov (United States)

    Li, Xiaobing; Brugger, Peter C; Huang, Min; Kasprian, Gregor; Li, Hong; Bettelheim, Dieter; Prayer, Daniela

    2013-04-01

    To study signal intensity (SI) of the fetal liver by MRI in-phase and out-of-phase over gestational age (GA). A total of 91 pregnant women from 19 to 38 gestational weeks were imaged using MRI. Liver-to-spleen SI ratios of the right and left fetal liver lobes on in-phase and out-of-phase were measured, calculated, and compared with each other. Curves of liver-to-spleen SI ratio of the right and left liver lobe were plotted by GA. Liver-to-spleen SI ratio of the right lobe on in-phase was different from that of the left liver lobe (t = 3.95; p < 0.001). A statistically significant difference was also found for out-of-phase SI ratios (t = 3.69; p < 0.001). Curves of liver-to-spleen SI ratio of the fetal liver on in-phase and out-of-phase showed changes against GA. Liver-to-spleen SI ratio is different between the right and left liver lobe, which probably results from the different blood supply. Curves of liver-to-spleen SI ratios between 19 to 38 gestational weeks reflect the changes of decreasing function of blood production by fetal liver. In-phase and out-of-phase may have clinical use in the early detection of disordered fetal growth and metabolism. © 2013 John Wiley & Sons, Ltd.

  9. Impact of Two Intense Dust Storms on Aerosol Characteristics and Radiative Forcing over Patiala, Northwestern India

    Directory of Open Access Journals (Sweden)

    Deepti Sharma

    2012-01-01

    Full Text Available Impact of dust storms on the aerosol characteristics and radiative forcing over Patiala, northwestern India has been studied during April-June of 2010 using satellite observations and ground-based measurements. Six dust events (DE have been identified during the study period with average values of Aqua-MODIS AOD550 and Microtops-II AOD500 over Patiala as 1.00±0.51 and 0.84±0.41, respectively while Aura-OMI AI exhibits high values ranging from 2.01 to 6.74. The Ångström coefficients α380–870 and β range from 0.12 to 0.31 and 0.95 to 1.40, respectively. The measured spectral AODs, the OPAC-derived aerosol properties and the surface albedo obtained from MODIS were used as main inputs in SBDART model for the calculation of aerosol radiative forcing (ARF over Patiala. The ARF at surface (SRF and top of atmosphere (TOA ranges from ∼−50 to −100 Wm−2 and from ∼−10 to −25 Wm−2, respectively during the maximum of dust storms. The radiative forcing efficiency was found to be −66 Wm−2AOD−1 at SRF and −14 Wm−2AOD−1 at TOA. High values of ARF in the atmosphere (ATM, ranging between ∼+40 Wm−2 and +80.0 Wm−2 during the DE days, might have significant effect on the warming of the lower and middle atmosphere and, hence, on climate over northwestern India.

  10. The influence of the current intensity on the damping characteristics for a magneto-rheological damper of passenger car

    Science.gov (United States)

    Dobre, A.; Andreescu, C. N.; Stan, C.

    2016-08-01

    Due to their simplicity and controllability, adaptive dampers became very popular in automotive engineering industry, especially in the passenger cars industry, in spite of technological obstacles inherent and the high cost of the magnetic fluid. “MagneRide” is the first technology which uses smart fluids in the shock absorbers of the vehicles adaptive suspensions. Since the discovery of the magneto-rheological effect there is a consistent progress regarding the control algorithms and hardware part itself. These magneto-rheological devices have a major potential which can be explored in various fields of applications. At present many companies make researches for the improvement of the response time and for obtaining a better response at low frequency and amplitude of the body car oscillations. The main objective of this paper is to determine the damping characteristic of a magnetorheological shock absorber of a passenger car. The authors aim to observe how to modify the damping characteristic by changing the intensity of the electric current. The experimental researches have being carried out on a complex and modern test bench especially built for testing shock absorbers, in order to compare the damping characteristic of the classical damper with the magneto-rheological damper.

  11. Migrants' Newborns Characteristics in a Neonatal Intensive Care Unit (NICU in Greece

    Directory of Open Access Journals (Sweden)

    Alexandra Skitsou

    2012-01-01

    Full Text Available Background: In Greece live large numbers of migrant women at reproductive age, originate from 215different countries. They show higher fertility rates and may experience higher risk of preterm birth.Their needs for antenatal and postpartum services have not been very well studied.Objectives: To investigate epidemiological characteristics of immigrant newborns in comparison withthose of Greek origin, aiming at identifying key areas for future intervention strategies.Methodology: The reference population was 484 offsprings (Greeks 47.7%, migrants 52.3% whowere born in a public maternity hospital in Athens, from 1/1-30/6/2008 and referred to its NICU,according to migrant status, gestation age, birth weight, mode of delivery, diagnosis and length of stay.We used SPSS 17.0, descriptive techniques and x2 independence test.Results: Á x2 independence test indicated that the two variables, nationality and mode of delivery arenot independent (the test was found statistically significant x2=23.13, df=2, p=0.000. Women ofGreek origin experience an increased rate of caesarian deliveries(a x2 independence test between nationality and birth weight (x2=0.92, df= 4, p=0.92, nationalityand gestation age (x2=3.06 df= 4 p=0.55, nationality and length of stay in NICU (x2=0.74 df=2p=0.70, wasn’t able to reject the independence of the variables above when tested in pairs(b regression analysis did not reveal a statistical significant correlation between nationality, gender,gestation age and mode of delivery with congenital disorders and perinatal infections (p>0.05Conclusions: Policies should target the reorganization of maternal care in the country, thedissemination of relevant information and the empowering of migrant women. Publication of leaflets inminority languages with health information patient rights and recruitment of mediators are needed.Attending Greek language courses would help their inclusion in the society. Furthermore, educationand training of

  12. Effect of biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging, on ultrasound-guided high-intensity focused ultrasound ablation.

    Science.gov (United States)

    Zhao, Wen-Peng; Chen, Jin-Yun; Chen, Wen-Zhi

    2015-02-01

    The aims of this study were to assess the effects of the biological characteristics of different types of uterine fibroids, as assessed with T2-weighted magnetic resonance imaging (MRI), on ultrasound-guided high-intensity focused ultrasound (USgHIFU) ablation. Thirty-five patients with 39 symptomatic uterine fibroids who underwent myomectomy or hysterectomy were enrolled. Before surgery, the uterine fibroids were subdivided into hypo-intense, iso-intense, heterogeneous hyper-intense and homogeneous hyper-intense categories based on signal intensity on T2-weighted MRI. Tissue density and moisture content were determined in post-operative samples and normal uterine tissue, the isolated uterine fibroids were subjected to USgHIFU, and the extent of ablation was measured using triphenyltetrazolium chloride. Hematoxylin and eosin staining and sirius red staining were undertaken to investigate the organizational structure of the uterine fibroids. Estrogen and progesterone receptor expression was assayed via immunohistochemical staining. The mean diameter of uterine fibroids was 6.9 ± 2.8 cm. For all uterine fibroids, the average density and moisture content were 10.7 ± 0.7 mg/mL and 75.7 ± 2.4%, respectively; and for the homogeneous hyper-intense fibroids, 10.3 ± 0.5 mg/mL and 76.6 ± 2.3%. The latter subgroup had lower density and higher moisture content compared with the other subgroups. After USgHIFU treatment, the extent of ablation of the hyper-intense fibroids was 102.7 ± 42.1 mm(2), which was significantly less than those of the hypo-intense and heterogeneous hyper-intense fibroids. Hematoxylin and eosin staining and sirius red staining revealed that the homogeneous hyper-intense fibroids had sparse collagen fibers and abundant cells. Immunohistochemistry results revealed that estrogen and progesterone receptors were highly expressed in the homogeneous hyper-intense fibroids. This study revealed that lower density, higher moisture content, sparse collagen

  13. Dynamic characteristics of two-state lasing quantum dot lasers under large signal modulation

    Energy Technology Data Exchange (ETDEWEB)

    Lv, Zun-Ren; Ji, Hai-Ming, E-mail: jhm@semi.ac.cn; Luo, Shuai; Gao, Feng; Xu, Feng; Yang, Tao, E-mail: tyang@semi.ac.cn [Key Laboratory of Semiconductor Materials Science, Institute of Semiconductors, Chinese Academy of Sciences, Beijing 100083 (China); Xiao, De-Hang, E-mail: xiaodehang@hlju.edu.cn [College of Physical Science and Technology, Heilongjiang University, Harbin 150080 (China)

    2015-10-15

    Large signal modulation characteristics of the simultaneous ground-state (GS) and excited-state (ES) lasing quantum dot lasers are theoretically investigated. Relaxation oscillations of ‘0 → 1’ and ‘1 → 0’ in the GS lasing region (Region I), the transition region from GS lasing to two-state lasing (Region II) and the two-state lasing region (Region III) are compared and analyzed. It is found that the overshooting power and settling time in both Regions I and III decrease as the bias current increases. However, there exist abnormal behaviors of the overshooting power and settling time in Region II owing to the occurrence of ES lasing, which lead to fuzzy eye diagrams of the GS and ES lasing. Moreover, the ES lasing in Region III possesses much better eye diagrams because of its shorter settling time and smaller overshooting power over the GS lasing in Region I.

  14. Fractal characteristics and its application in electromagnetic radiation signals during fracturing of coal or rock

    Institute of Scientific and Technical Information of China (English)

    Wang Chao; Xu Jiankun; Zhao Xiaoxia; Wei Mingyao

    2012-01-01

    The present study analyzed the electromagnetic radiation (EMR) time series of the destruction process of coal or rock sample under uniaxial loading and the monitoring process in working face by means of frac tal geometry,and results of the correlation dimension change curve of EMR time series were obtained.In the meantime,the current study also sought the fractal characteristic to the EMR signals by contrast to,the change curve of EMR signals and explored the precursory phenomenon of rock burst.This paper con cluded the main findings as followed:the EMR time series of the destruction process of coal or rock sam ple under uniaxial loading and the monitonng process in working face corresponded to fractal;the correlation dimension of EMR time series reflected the process of coal or rock damage deformation,that is,the inner damage of coal or rock made a change from random to order.In the field application,the correlation dimension served as a new index of forecasting the coal or rock dynamic disaster.

  15. Spectral characteristics of high-latitude raw 40 MHz cosmic noise signals

    Science.gov (United States)

    Hall, Chris M.

    2016-08-01

    Cosmic noise at 40 MHz is measured at Ny-Ålesund (79° N, 12° E) using a relative ionospheric opacity meter ("riometer"). A riometer is normally used to determine the degree to which cosmic noise is absorbed by the intervening ionosphere, giving an indication of ionisation of the atmosphere at altitudes lower than generally monitored by other instruments. The usual course is to determine a "quiet-day" variation, this representing the galactic noise signal itself in the absence of absorption; the current signal is then subtracted from this to arrive at absorption expressed in decibels (dB). By a variety of means and assumptions, it is thereafter possible to estimate electron density profiles in the very lowest reaches of the ionosphere. Here however, the entire signal, i.e. including the cosmic noise itself, will be examined and spectral characteristics identified. It will be seen that distinct spectral subranges are evident which can, in turn, be identified with non-Gaussian processes characterised by generalised Hurst exponents, α. Considering all periods greater than 1 h, α ≈ 24, an indication of fractional Brownian motion, whereas for periods greater than 1 day α ≈ 0.9 - approximately pink noise and just in the domain of fractional Gaussian noise. The results are compared with other physical processes, suggesting that absorption of cosmic noise is characterised by a generalised Hurst exponent ≈ 1.24 and thus non-persistent fractional Brownian motion, whereas generation of cosmic noise is characterised by a generalised Hurst exponent ≈ 1. The technique unfortunately did not result in clear physical understanding of the ionospheric phenomena, and thus, in this respect, the application was not successful; the analysis could, however, be used as a tool for instrument validation.

  16. Intensive care unit admission in patients following rapid response team activation: call factors, patient characteristics and hospital outcomes.

    Science.gov (United States)

    Le Guen, M P; Tobin, A E; Reid, D

    2015-03-01

    Rapid Response Systems (RRSs) have been widely introduced throughout hospital health systems, yet there is limited research on the characteristics and outcomes of patients admitted to an intensive care unit (ICU) following RRS activation. Using database extraction, this study examined the factors associated with ICU admission and patient outcome in patients receiving RRS activation in a tertiary level hospital between 2009 and 2013. Of 3004 RRS activations, 392 resulted in ICU admissions. Call factors associated with ICU admission and increased hospital mortality included tachypnoea (P Medical Emergency Team call triggers breached simultaneously (P admission included young age (P admission and hospital mortality post RRS activation. This information may be useful for risk stratification of deteriorating patients and determination of appropriate escalation.

  17. Variations in semen characteristics rams of Ouled Djellal breed have received an important dietary supplement after regular and intensive collection

    Institute of Scientific and Technical Information of China (English)

    Litim Miloud; Bereksi Reguig Karima

    2015-01-01

    Objective: To evaluate the effect of an important dietary supplement on sperm quantity and quality breeding rams of artificial insemination center Belhandjir in region of Naama in Algeria. Methods:Ten breeding rams of the white arab breed, called Ouled Djellal are divided into two groups CR and SR, and subjected to two different diets, the first group CR followed a regime R based of barley and fodder and the second SR group to follow a regime R +a vitamin and mineral dietary supplement for a 15 weeks of regular collections followed by 12 weeks of intensive collections. Analysis of sperm quality and quantity were performed to normal and intensive collection. Results:The quantitative effect is more significant in rams supplemented SR, volume and concentration were higher in rams SR (respectively+40%and±13%), therefore the doses produced differ significantly compared to the group of control rams CR (+70%). Results of qualitative parameters were more mixed, motility showed a significant difference in rams supplemented with against the rate of dead semen and the rate of anomalies did not show significant differences in sperm. Conclusion:supplementation could significantly improve the quantitative semen characteristics in rams breeding Ouled Djellal. Collections of semen on the rams may be daily without sperm quantity is affected.

  18. IL-12 Family Cytokines: General Characteristics, Pathogenic Microorganisms, Receptors, and Signalling Pathways.

    Science.gov (United States)

    Behzadi, Payam; Behzadi, Elham; Ranjbar, Reza

    2016-03-01

    Among a wide range of cytokines, the Interleukin 12 (IL-12) family has its unique structural, functional, and immunological characteristics that have made this family as important immunological playmakers. Because of the importance of IL-12 heterodimeric cytokines in microbial infections, autoimmune diseases, and cancers, the authors of this literature discuss about the general characteristics of IL-12 family members, the interactions between IL-12 cytokines and pathogenic microorganisms, the interleukins receptors and their strategies for selecting different signalling pathways. IL-12 and IL-23 are similar in p40 subunits and both are involved in proinflammatory responses while, IL-27 and IL-35 contribute to anti-inflammatory activities; however, IL-27 is also involved in pro-inflammatory responses. There are some similarities and dissimilarities among IL-12 family members which make them a unique bridge between innate and adaptive immune systems. The bioactivities of IL-12 family indicate a brilliant promise for their applications in different fields of medicine. The members of IL-12 family are candidate for several therapeutics including gene therapy, cancer therapy, tumour therapy, and vaccination. To have an accurate diagnostic technique and definite treatment regarding to infectious diseases, the playmakers of IL-12 family as effective criteria together with microarray technology are the best choices for current and future applications.

  19. Predictive value of T2 relative signal intensity for response to somatostatin analogs in newly diagnosed acromegaly

    Energy Technology Data Exchange (ETDEWEB)

    Shen, Ming; Zhang, Qilin [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Liu, Wenjuan; Li, Yiming; Zhang, Zhaoyun; Ye, Hongying; He, Min; Lu, Bin; Yang, Yeping [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Shanghai (China); Wang, Meng [Fudan University, Department of Endocrinology and Metabolism, Huashan Hospital, Shanghai Medical College, Shanghai (China); Soochow University, Division of Endocrinology, the Second Affiliated Hospital, Suzhou (China); Zhu, Jingjing [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Neuropathology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Ma, Zengyi; He, Wenqiang; Li, Shiqi; Shou, Xuefei; Qiao, Nidan; Ye, Zhao; Zhang, Yichao; Zhao, Yao; Wang, Yongfei [Fudan University, Department of Neurosurgery, Huashan Hospital, Shanghai Medical College, Shanghai (China); Shanghai Pituitary Tumor Center, Shanghai (China); Yao, Zhenwei [Shanghai Pituitary Tumor Center, Shanghai (China); Fudan University, Department of Radiology, Huashan Hospital, Shanghai Medical College, Shanghai (China); Lu, Yun [Fudan University, Department of Nuclear Medicine, Huashan Hospital, Shanghai Medical College, Shanghai (China)

    2016-11-15

    The difficulty of predicting the efficacy of somatostatin analogs (SSA) is not fully resolved. Here, we quantitatively evaluated the predictive value of relative signal intensity (rSI) on T1- and T2-weighted magnetic resonance imaging (MRI) for the short-term efficacy (3 months) of SSA therapy in patients with active acromegaly and assessed the correlation between MRI rSI and expression of somatostatin receptors (SSTR). This was a retrospective review of prospectively recorded data. Ninety-two newly diagnosed patients (37 males and 55 females) with active acromegaly were recruited. All patients were treated with pre-surgical SSA, followed by reassessment and transspenoidal surgery. rSI values were generated by calculating the ratio of SI in the tumor to the SI of normal frontal white matter. The Youden indices were calculated to determine the optimal cutoff of rSI to determine the efficacy of SSA. The correlation between rSI and expression of SSTR2/5 was analyzed by the Spearman rank correlation coefficient. T2 rSI was strongly correlated with biochemical sensitivity to SSA. The cutoff value of T2 rSI to distinguish biochemical sensitivity was 1.205, with a positive predictive value (PPV) of 81.5 % and a negative predictive value (NPV) of 77.3 %. No correlation was found between MRI and tumor size sensitivity. Moreover, T2 rSI was negatively correlated with the expression of SSTR5. T2 rSI correlates with the expression of SSTR5 and quantitatively predicts the biochemical efficacy of SSA in acromegaly. (orig.)

  20. Selecting Statistical Characteristics of Brain Signals to Detect Epileptic Seizures using Discrete Wavelet Transform and Perceptron Neural Network

    Directory of Open Access Journals (Sweden)

    Rezvan Abbasi

    2017-08-01

    Full Text Available Electroencephalogram signals (EEG have always been used in medical diagnosis. Evaluation of the statistical characteristics of EEG signals is actually the foundation of all brain signal processing methods. Since the correct prediction of disease status is of utmost importance, the goal is to use those models that have minimum error and maximum reliability. In anautomatic epileptic seizure detection system, we should be able to distinguish between EEG signals before, during and after seizure. Extracting useful characteristics from EEG data can greatly increase the classification accuracy. In this new approach, we first parse EEG signals to sub-bands in different categories with the help of discrete wavelet transform(DWT and then we derive statistical characteristics such as maximum, minimum, average and standard deviation for each sub-band. A multilayer perceptron (MLPneural network was used to assess the different scenarios of healthy and seizure among the collected signal sets. In order to assess the success and effectiveness of the proposed method, the confusion matrix was used and its accuracy was achieved98.33 percent. Due to the limitations and obstacles in analyzing EEG signals, the proposed method can greatly help professionals experimentally and visually in the classification and diagnosis of epileptic seizures.

  1. Statistical characteristics of suction pressure signals for a centrifugal pump under cavitating conditions

    Science.gov (United States)

    Li, Xiaojun; Yu, Benxu; Ji, Yucheng; Lu, Jiaxin; Yuan, Shouqi

    2017-02-01

    Centrifugal pumps are often used in operating conditions where they can be susceptible to premature failure. The cavitation phenomenon is a common fault in centrifugal pumps and is associated with undesired effects. Among the numerous cavitation detection methods, the measurement of suction pressure fluctuation is one of the most used methods to detect or diagnose the degree of cavitation in a centrifugal pump. In this paper, a closed loop was established to investigate the pump cavitation phenomenon, the statistical parameters for PDF (Probability Density Function), Variance and RMS (Root Mean Square) were used to analyze the relationship between the cavitation performance and the suction pressure signals during the development of cavitation. It is found that the statistical parameters used in this research are able to capture critical cavitation condition and cavitation breakdown condition, whereas difficult for the detection of incipient cavitation in the pump. At part-load conditions, the pressure fluctuations at the impeller inlet show more complexity than the best efficiency point (BEP). Amplitude of PDF values of suction pressure increased steeply when the flow rate dropped to 40 m3/h (the design flow rate was 60 m3/h). One possible reason is that the flow structure in the impeller channel promotes an increase of the cavitation intensity when the flow rate is reduced to a certain degree. This shows that it is necessary to find the relationship between the cavitation instabilities and flow instabilities when centrifugal pumps operate under part-load flow rates.

  2. Increased signal intensities in the dentate nucleus and globus pallidus on unenhanced T1-weighted images: evidence in children undergoing multiple gadolinium MRI exams

    Energy Technology Data Exchange (ETDEWEB)

    Hu, Houchun H.; Pokorney, Amber; Towbin, Richard B.; Miller, Jeffrey H. [Phoenix Children' s Hospital, Department of Medical Imaging and Radiology, Phoenix, AZ (United States)

    2016-10-15

    Recent reports have suggested residual gadolinium deposition in the brain in subjects undergoing multiple contrast-enhanced MRI exams. These findings have raised some concerns regarding gadolinium-based contrast agent (GBCA) usage and retention in brain tissues. To summarize findings of hyperintense brain structures on precontrast T1-weighted images in 21 children undergoing multiple GBCA MRI exams. This retrospective study involved 21 patients, each of whom received multiple MRI examinations (range: 5-37 exams) with GBCA over the course of their medical treatment (duration from first to most recent exam: 1.2-12.9 years). The patients were between 0.9 and 14.4 years of age at the time of their first GBCA exam. Regions of interest were drawn in the dentate nucleus and the globus pallidus on 2-D fast spin echo images acquired at 1.5 T. The signal intensities of these two structures were normalized by that of the corpus callosum genu. Signal intensity ratios from these patients were compared to control patients of similar ages who have never received GBCA. Signal intensity ratios increased between the first and the most recent MRI exam in all 21 patients receiving GBCA, with an increase of 18.6%±12.7% (range: 0.5% to 47.5%) for the dentate nucleus and 12.4%±7.4% (range: -1.2% to 33.7%) for the globus pallidus (P<0.0001). Signal intensity ratios were also higher in GBCA patients than in controls (P<0.01). The degree of signal intensity enhancement did not correlate with statistical significance to the cumulative number or volume of GBCA administrations each patient received, the patient's age or the elapsed time between the first and most recent GBCA MRI exams. These results in children are consistent with recent findings in adults, suggesting possible gadolinium deposition in the brain. (orig.)

  3. Effect of Light Intensity and Temperature on the Current Voltage Characteristics of Al/ SY/ p- Si Organic-Inorganic Heterojunction

    Science.gov (United States)

    Imer, Arife Gencer; Ocak, Yusuf Selim

    2016-10-01

    An organic-inorganic contact was fabricated by forming a thin film of sunset yellow dye ( SY) on a p- Si wafer. The device showed a good rectification property, and the sunset yellow thin film modified the barrier height (Φb) of Al/ p- Si contact by influencing the space charge region. The heterojunction had a strong response to the different illumination intensities and showed that it can be suitable for photodiode applications. The I- V measurements of the device were also applied in the temperature range of 100-500 K. It was seen that characteristic parameters of the device were strongly dependent upon temperature. While the value of Φb increased, the ideality factor ( n) decreased with the increase in temperature. This variation was attributed to spatial inhomogeneity at the interface. The Norde function was used to determine the temperature-dependent series resistance and Φb values, and there was a good agreement with that of ln I- V data. The values of the Richardson constant ( A*) and mean Φb were determined as 29.47 Acm-2 K-2 by means of a modified activation energy plot, matching with a theoretical one, and 1.032 eV, respectively. Therefore, it was stated that the current voltage characteristic with the temperature can be explained by thermionic emission theory with Gaussian distribution of the Φb at the interface.

  4. Plasma and Magnetic Field Characteristics of Solar Coronal Mass Ejections in Relation to Geomagnetic Storm Intensity and Variability

    CERN Document Server

    Liu, Ying D; Wang, Rui; Yang, Zhongwei; Zhu, Bei; Liu, Yi A; Luhmann, Janet G; Richardson, John D

    2015-01-01

    The largest geomagnetic storms of solar cycle 24 so far occurred on 2015 March 17 and June 22 with $D_{\\rm st}$ minima of $-223$ and $-195$ nT, respectively. Both of the geomagnetic storms show a multi-step development. We examine the plasma and magnetic field characteristics of the driving coronal mass ejections (CMEs) in connection with the development of the geomagnetic storms. A particular effort is to reconstruct the in situ structure using a Grad-Shafranov technique and compare the reconstruction results with solar observations, which gives a larger spatial perspective of the source conditions than one-dimensional in situ measurements. Key results are obtained concerning how the plasma and magnetic field characteristics of CMEs control the geomagnetic storm intensity and variability: (1) a sheath-ejecta-ejecta mechanism and a sheath-sheath-ejecta scenario are proposed for the multi-step development of the 2015 March 17 and June 22 geomagnetic storms, respectively; (2) two contrasting cases of how the CM...

  5. Clinical Characteristics and 30-Day Outcomes of Intermittent Hemodialysis for Acute Kidney Injury in an African Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Arthur Kwizera

    2016-01-01

    Full Text Available Introduction. Acute kidney injury (AKI is a common occurrence in the intensive care unit (ICU. Studies have looked at outcomes of renal replacement therapy using intermittent haemodialysis (IHD in ICUs with varying results. Little is known about the outcomes of using IHD in resource-limited settings where continuous renal replacement therapy (CRRT is limited. We sought to determine outcomes of IHD among critically ill patients admitted to a low-income country ICU. Methods. A retrospective review of patient records was conducted. Patients admitted to the ICU who underwent IHD for AKI were included in the study. Patients’ demographic and clinical characteristics, cause of AKI, laboratory parameters, haemodialysis characteristics, and survival were interpreted and analyzed. Primary outcome was mortality. Results. Of 62 patients, 40 had complete records. Median age of patients was 38.5 years. Etiologic diagnoses associated with AKI included sepsis, malaria, and ARDS. Mortality was 52.5%. APACHE II (OR 4.550; 95% CI 1.2–17.5, p=0.028, mechanical ventilation (OR 13.063; 95% CI 2.3–72, p=0.003, and need for vasopressors (OR 16.8; 95% CI 3.4–82.6, p=0.001 had statistically significant association with mortality. Conclusion. IHD may be a feasible alternative for RRT in critically ill haemodynamically stable patients in low resource settings where CRRT may not be available.

  6. Probing geomagnetic storm-driven magnetosphere-ionosphere dynamics in D-region via propagation characteristics of very low frequency radio signals

    Science.gov (United States)

    Nwankwo, Victor U. J.; Chakrabarti, Sandip K.; Ogunmodimu, Olugbenga

    2016-07-01

    The amplitude and phase of VLF/LF radio signals are sensitive to changes in electrical conductivity of the lower ionosphere which imprints its signature on the Earth-ionosphere waveguide. This characteristic makes it useful in studying sudden ionospheric disturbances, especially those related to prompt X-ray flux output from solar flares and gamma ray bursts (GRBs). However, strong geomagnetic disturbance and storm conditions are known to produce large and global ionospheric disturbances, which can significantly affect VLF radio propagation in the D region of the ionosphere. In this paper, using the data of three propagation paths at mid-latitudes (40-54°), we analyse the trend in variation of aspects of VLF diurnal signal under varying solar and geomagnetic space environmental conditions in order to identify possible geomagnetic footprints on the D region characteristics. We found that the trend of variations generally reflected the prevailing space weather conditions in various time scales. In particular, the 'dipping' of mid-day signal amplitude peak (MDP) occurs after significant geomagnetic perturbed or storm conditions in the time scale of 1-2 days. The mean signal amplitude before sunrise (MBSR) and mean signal amplitude after sunset (MASS) also exhibit storm-induced dipping, but they appear to be influenced by event's exact occurrence time and the highly variable conditions of dusk-to-dawn ionosphere. We also observed few cases of the signals rise (e.g., MDP, MBSR or MASS) following a significant geomagnetic event. This effect may be related to storms associated phenomena or effects arising from sources other than solar origin. The magnitude of induced dipping (or rise) significantly depends on the intensity and duration of event(s), as well as the propagation path of the signal. The post-storm day signal (following a main event, with lesser or significantly reduced geomagnetic activity) exhibited a tendency of recovery to pre-storm day level. In the

  7. Hedgehog signaling antagonist GDC-0449 (Vismodegib inhibits pancreatic cancer stem cell characteristics: molecular mechanisms.

    Directory of Open Access Journals (Sweden)

    Brahma N Singh

    Full Text Available BACKGROUND: Recent evidence from in vitro and in vivo studies has demonstrated that aberrant reactivation of the Sonic Hedgehog (SHH signaling pathway regulates genes that promote cellular proliferation in various human cancer stem cells (CSCs. Therefore, the chemotherapeutic agents that inhibit activation of Gli transcription factors have emerged as promising novel therapeutic drugs for pancreatic cancer. GDC-0449 (Vismodegib, orally administrable molecule belonging to the 2-arylpyridine class, inhibits SHH signaling pathway by blocking the activities of Smoothened. The objectives of this study were to examine the molecular mechanisms by which GDC-0449 regulates human pancreatic CSC characteristics in vitro. METHODOLOGY/PRINCIPAL FINDINGS: GDC-0499 inhibited cell viability and induced apoptosis in three pancreatic cancer cell lines and pancreatic CSCs. This inhibitor also suppressed cell viability, Gli-DNA binding and transcriptional activities, and induced apoptosis through caspase-3 activation and PARP cleavage in pancreatic CSCs. GDC-0449-induced apoptosis in CSCs showed increased Fas expression and decreased expression of PDGFRα. Furthermore, Bcl-2 was down-regulated whereas TRAIL-R1/DR4 and TRAIL-R2/DR5 expression was increased following the treatment of CSCs with GDC-0449. Suppression of both Gli1 plus Gli2 by shRNA mimicked the changes in cell viability, spheroid formation, apoptosis and gene expression observed in GDC-0449-treated pancreatic CSCs. Thus, activated Gli genes repress DRs and Fas expressions, up-regulate the expressions of Bcl-2 and PDGFRα and facilitate cell survival. CONCLUSIONS/SIGNIFICANCE: These data suggest that GDC-0499 can be used for the management of pancreatic cancer by targeting pancreatic CSCs.

  8. Micro RNA-126 coordinates cell behavior and signaling cascades according to characteristics of breast cancer cells.

    Science.gov (United States)

    Turgut Cosan, D; Oner, C; Mutlu Sahin, F

    2016-01-01

    Micro RNA-126 is known to enhance apoptotic processes and also plays a role in vascular growth through the regulation of vascular endothelial growth factor-mediated signaling, angiogenesis, and vascular integrity. We aimed to determine the role of miR-126 in breast cancer cell lines with a variety of different characteristics to evaluate its interaction with certain cancer-related molecules and mechanisms. To determine the effect of presence and absence of miR-126 in MCF-7 and MDA-MB-231 breast cancer cells, miR-126 mimics and inhibitor were transfected. miRNA and gene expressions were observed by using RT-PCR. Viability, proliferation, adhesion, invasion and lateral motility assays were performed to determine cell behavior changes. miR-126 is more effective on MDA-MB-231 cells on cell behavior. We observed an increase in miR-126 expression when miR-126 mimics was transfected to MCF-7 and MDA-MB-231 cells. Also, there was a decrease in miR-126 expression when MCF-7 and MDA-MB-231 cells were transfected with miR-126 inhibitor. Furthermore, presence and absence of miR-126 modulated the gene expressions of VEGF/PI3K/AKT and MAPK signaling in MCF-7 and MDA-MB-231. Our study showed that miR-126 is in a state of interaction with a multitude molecules playing a role in breast cancer. According to obtained data, we can say that miR-126 may be more effective in inhibition of metastatic breast cancer (Tab. 4, Fig. 3, Ref. 46).

  9. NOISE CHARACTERISTIC AND SEASONAL SIGNALS IN THE RE-PROCESSED EUREF PERMANENT NETWORK COORDINATE TIME SERIES

    Science.gov (United States)

    Kenyeres, A.; Williams, S. D.; Figurski, M.; van Dam, T. M.; Szafranek, K.

    2009-12-01

    Previous analyses of periodic signals present in continuous GPS time series showed that the amplitude and phase of the derived seasonal term mostly disagree with surface mass loading models. The CGPS results appeared to over-estimate the amplitude of the seasonal term and the estimated amplitudes and/or phases were poorly coherent with the loading models, especially at sites close to coastal areas. The studies concluded that the GPS results are distorted by analysis artifacts (such as ocean tide loading, aliasing, and antenna phase centre variation models), monument thermal effects, and multipath. In addition, the actual CGPS time series were inhomogeneous in terms of processing strategy, applied models and reference frame alignment. With the introduction of absolute antenna phase centre variation models an effort, within the EUREF Permanent Network, was initiated to produce a complete GPS re-analysis from global to local levels. A test re-processing of all EPN observations from 1996 to 2007 has already been completed by the Military University of Technology (MUT), Warsaw, Poland and cumulative EPN solutions, from the daily SINEX files, have been created using the CATREF software. We used a combination of Weighted Least Squares, Maximum Likelihood Estimation (MLE), Empirical Orthogonal Functions (EOF’s) and Wavelets to analyze the data for their spatial and temporal noise characteristics and investigate the periodic signals. We find that the noise levels in the re-processed daily solutions is reduced compared to past solutions, but the noise spectra is still represented by a combination of flicker noise and white noise. The amplitudes of the seasonal term have generally decreased and the spatial distribution of the phase lag appears to be more uniform. Comparisons of the estimated annual variations with combined loading models (NCEP + LaD - World - Fraser + ECCO) and the vertical displacement model of the GRACE R4 gravity fields show an improved agreement

  10. Brain MR imaging in patients with hepatic cirrhosis: relationship between high intensity signal in basal ganglia on T{sub 1}-weighted images and elemental concentrations in brain

    Energy Technology Data Exchange (ETDEWEB)

    Maeda, H. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan); Sato, M. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan); Yoshikawa, A. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan); Kimura, M. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan); Sonomura, T. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan); Terada, M. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan); Kishi, K. [Department of Radiology, Wakayama Medical College, 27-7, Wakayama City, 640 (Japan)

    1997-08-01

    In patients with hepatic cirrhosis, the globus pallidus and putamen show high intensity on T1-weighted MRI. While the causes of this high signal have been thought to include paramagnetic substances, especially manganese, no evidence for this has been presented. Autopsy in four cases of hepatic cirrhosis permitted measurement of metal concentrations in brain and histopathological examination. In three cases the globus pallidus showed high intensity on T1-weighted images. Mean manganese concentrations in globus pallidus, putamen and frontal white matter were 3.03 {+-} 0.38, 2.12 {+-} 0.37, and 1.38 {+-} 0.24 ({mu}g/g wet weight), respectively, being approximately four- to almost ten-fold the normal values. Copper concentrations in globus pallidus and putamen were also high, 50 % more than normal. Calcium, iron, zinc and magnesium concentrations were all normal. The fourth case showed no abnormal intensity in the basal ganglia and brain metal concentrations were all normal. Histopathologically, cases with showing high signal remarkable atrophy, necrosis, and deciduation of nerve cells and proliferation of glial cells and microglia in globus pallidus. These findings were similar to those in chronic manganese poisoning. On T1-weighted images, copper deposition shows no abnormal intensity. It is therefore inferred that deposition of highly concentrations of manganese may caused high signal on T1-weighted images and nerve cell death in the globus pallidus. (orig.). With 2 figs., 2 tabs.

  11. Signal and Noise Modeling of Microwave Transistors Using Characteristic Support Vector-based Sparse Regression

    Directory of Open Access Journals (Sweden)

    F. Gunes

    2016-09-01

    Full Text Available In this work, an accurate and reliable S- and Noise (N - parameter black-box models for a microwave transistor are constructed based on the sparse regression using the Support Vector Regression Machine (SVRM as a nonlinear extrapolator trained by the data measured at the typical bias currents belonging to only a single bias voltage in the middle region of the device operation domain of (VDS/VCE, IDS/IC, f. SVRMs are novel learning machines combining the convex optimization theory with the generalization and therefore they guarantee the global minimum and the sparse solution which can be expressed as a continuous function of the input variables using a subset of the training data so called Support Vector (SVs. Thus magnitude and phase of each S- or N- parameter are expressed analytically valid in the wide range of device operation domain in terms of the Characteristic SVs obtained from the substantially reduced measured data. The proposed method is implemented successfully to modelling of the two LNA transistors ATF-551M4 and VMMK 1225 with their large operation domains and the comparative error-metric analysis is given in details with the counterpart method Generalized Regression Neural Network GRNN. It can be concluded that the Characteristic Support Vector based-sparse regression is an accurate and reliable method for the black-box signal and noise modelling of microwave transistors that extrapolates a reduced amount of training data consisting of the S- and N- data measured at the typical bias currents belonging to only a middle bias voltage in the form of continuous functions into the wide operation range.

  12. Abrogation of Nrf2 impairs antioxidant signaling and promotes atrial hypertrophy in response to high-intensity exercise stress.

    Science.gov (United States)

    Kumar, Radhakrishnan Rajesh; Narasimhan, Madhusudhanan; Shanmugam, Gobinath; Hong, Jennifer; Devarajan, Asokan; Palaniappan, Sethu; Zhang, Jianhua; Halade, Ganesh V; Darley-Usmar, Victor M; Hoidal, John R; Rajasekaran, Namakkal S

    2016-04-05

    Anomalies in myocardial structure involving myocyte growth, hypertrophy, differentiation, apoptosis, necrosis etc. affects its function and render cardiac tissue more vulnerable to the development of heart failure. Although oxidative stress has a well-established role in cardiac remodeling and dysfunction, the mechanisms linking redox state to atrial cardiomyocyte hypertrophic changes are poorly understood. Here, we investigated the role of nuclear erythroid-2 like factor-2 (Nrf2), a central transcriptional mediator, in redox signaling under high intensity exercise stress (HIES) in atria. Age and sex-matched wild-type (WT) and Nrf2(-/-) mice at >20 months of age were subjected to HIES for 6 weeks. Gene markers of hypertrophy and antioxidant enzymes were determined in the atria of WT and Nrf2(-/-) mice by real-time qPCR analyses. Detection and quantification of antioxidants, 4-hydroxy-nonenal (4-HNE), poly-ubiquitination and autophagy proteins in WT and Nrf2(-/-) mice were performed by immunofluorescence analysis. The level of oxidative stress was measured by microscopical examination of di-hydro-ethidium (DHE) fluorescence. Under the sedentary state, Nrf2 abrogation resulted in a moderate down regulation of some of the atrial antioxidant gene expression (Gsr, Gclc, Gstα and Gstµ) despite having a normal redox state. In response to HIES, enlarged atrial myocytes along with significantly increased gene expression of cardiomyocyte hypertrophy markers (Anf, Bnf and β-Mhc) were observed in Nrf2(-/-) when compared to WT mice. Further, the transcript levels of Gclc, Gsr and Gstµ and protein levels of NQO1, catalase, GPX1 were profoundly downregulated along with GSH depletion and increased oxidative stress in Nrf2(-/-) mice when compared to its WT counterparts after HIES. Impaired antioxidant state and profound oxidative stress were associated with enhanced atrial expression of LC3 and ATG7 along with increased ubiquitination of ATG7 in Nrf2(-/-) mice subjected to HIES

  13. Evaluation of the Effect of Sociodemographic Characteristics on the Satisfaction of Mothers in Neonatal Intensive Care Units in Turkey

    Directory of Open Access Journals (Sweden)

    Fatma Yılmaz

    2016-03-01

    Full Text Available Background: Patient and parent satisfaction is a significant indicator for the evaluation of quality of care in healthcare systems. This study aimed to evaluate the effect of sociodemographic characteristics on the satisfaction of the parents of newborns admitted in neonatal intensive care units (NICUs in maternity and infant disease hospitals. Methods: This descriptive study was conducted on 113 mothers with infants admitted in the NICU of a state hospital in Turkey during April 1-September 30, 2013.Data were collected using sociodemographic questionnaire and Pediatric Quality of Life Inventory (PedsQL healthcare satisfaction scale. Data analysis was performed using descriptive statistics (mean and percentage, T-test, Mann-Whitney U test, and Kruskal-Wallis test. Results: In this study, mean score of maternal satisfaction with NICU services was 65.66±20.01. No statistically significant differences were observed between maternal age, PedsQL satisfaction subscales, and total score of satisfaction. Moreover, statistically significant associations were observed between the following variables: maternal training and total satisfaction, employment status and subscales of PedsQL, technical skills and general satisfaction, and social security status and emotional support. However, no statistically significant differences were observed between the sociodemographic characteristics of newborns, total score of satisfaction, and mean scores of PedsQL satisfaction subscales in mothers. Conclusion: According to the results of this study, level of maternal satisfaction with NICU services was higher than the international average. Therefore, it is recommended that NICU nurses offer sufficient emotional support for both mothers and neonates in this unit and allow mothers to stay with their infants during hospitalization. Furthermore, it is suggested that training programs be implemented on effective communication skills between nurses and patients.

  14. ENSO signals and their spatial-temporal variation characteristics recorded by the sea-level changes in the northwest Pacific margin during 1965-2005

    Institute of Scientific and Technical Information of China (English)

    YUAN LinWang; YU ZhaoYuan; XIE ZhiRen; SONG ZhiYao; L(U) GuoNian

    2009-01-01

    Sea-level is closely linked to the Earth's climate and its change is important as a metric for global and regional climate change.Identifying,extracting,and revealing such information through detailed analysis is the prerequisite for understanding the mechanisms of sea-level change.The monthly- av-erage tide-change records reported and examined in this paper are from 10 tide gauge stations dis-tributed in the northwest margin of the Pacific Ocean,registered during the period 1965-2005.In particular,we have utilized the Second Order Blind Identification (SOBI) method to identify and the Empirical Mode Decomposition (EMD) method to extract the El Nino-Southern Oscillation (ENSO) sig-nals imprinted in those tide gauge records; and subsequently,we have investigated the spa-tial-temporal characteristics of the extracted ENSO signals using wavelet analysis methods.The fol-lowing results are obtained:(1) the ENSO events recorded by each tide gauge series are of different types and intensity,which show considerable temporal-spatial variation characteristics,with sea-level responses to ENSO signals remarkably stronger in low latitude areas than in medium-high latitude areas; (2) due to the influences of ocean currents,topographical conditions,and other factors,there exist variations in the type of relationship between the sea-level changes and the recorded ENSO events at different latitudes; (3) sea-level changes can also denote scale-variation characteristics of ENSO events,and particularly,since 1980s,all the tide gauges located south of Kanmen show intense responses to ENSO and the timescale of ENSO events extended gradually from around 4 years to 2-8 years,reflecting variations in the intensity and frequency of ENSO events; and (4) reverse changes of certain scale were noted before and after strong ENSO events recorded by sea-level changes,sup-porting the research findings about the interaction (mutual coupling and superimposition) between the probability of occurrence

  15. Interdecadal component variation characteristics in heavy winter snow intensity in North-Eastern China and its response to sea surface temperatures

    Science.gov (United States)

    Zhao, Chun-Yu; Fang, Yi-He; Luo, Yong; Wang, Ji

    2016-11-01

    Based on daily precipitation data from 208 weather stations, monthly NCEP/NCAR reanalysis data, and sea surface temperature data reconstructed by NOAA between 1961 and 2012, the heavy winter snow intensity in North-Eastern China was defined; its spatiotemporal variation characteristics were analyzed; the physical mechanisms of the relations between key sea surface temperature (SST) regions and heavy winter snow intensity were studied. Results showed that, in terms of temporal variation characteristics: heavy winter snow intensity in North-Eastern China has been rising, with obvious interdecadal variations during the study interval. In terms of spatial variation characteristics: the first empirical orthogonal function (EOF) mode of the interdecadal component in heavy winter snow intensity showed consistent anomaly characteristics throughout the region; the second mode exhibited opposite variation characteristics between the south and north; and the third mode exhibited opposite variation characteristics between the northwest and southeast. In terms of physical mechanisms underlying the effects of SST on heavy winter snow intensity, the key SST region of the first EOF mode was the Oyashio, the interdecadal component of the autumn Oyashio SST was abnormally high, which corresponded to a higher winter 500 hPa height field in the northern section of the North Pacific. This condition led to a blocking situation and was associated with a weaker East Asian winter monsoon (EAMW), which resulted in a stronger interdecadal component of heavy winter snow intensity and vice versa. The second mode was closely related to the Pacific Decadal Oscillation (PDO): the interdecadal component of the autumn PDO was abnormal, which induced the teleconnection pattern of the winter Pacific-North America (PNA) pattern. The PNA pattern may have been related to the second EOF mode through its association with the Mongolian high.

  16. Measurement of signal intensity depth profiles in rat brains with cardiac arrest maintaining primary temperature by wide-field optical coherence tomography.

    Science.gov (United States)

    Sato, Manabu; Nomura, Daisuke; Tsunenari, Takashi; Nishidate, Izumi

    2010-09-10

    We have already reported that after an injection for euthanasia, the signal intensity of optical coherence tomography (OCT) images are 2.7 times increased before cardiac arrest (CA) using OCT and rat brains without temperature control to show the potential of OCT to monitor tissue viability in brains [Appl. Opt.48, 4354 (2009)APOPAI0003-693510.1364/AO.48.004354]. In this paper, we similarly measured maintaining the primary temperature of rat brains. It was confirmed that when maintaining the primary temperature, the time courses of the ratios of signal intensity (RSIs) were almost the same as those without temperature control. RSIs after CA varied from 1.6 to 4.5 and depended on positions measured in tissues. These results mean that the OCT technique has clinical potential for applications to monitor or diagnose a focal degraded area, such as cerebral infarctions due to focal ischemia in brains.

  17. Suspended sediment export in five intensive agricultural river catchments with contrasting land use and soil drainage characteristics

    Science.gov (United States)

    Sherriff, Sophie; Rowan, John; Melland, Alice; Jordan, Phil; Fenton, Owen; hUallacháin, Daire Ó.

    2015-04-01

    Soil erosion and sediment loss from land can have a negative impact on the chemical and ecological quality of freshwater resources. In catchments dominated by agriculture, prediction of soil erosion risk is complex due to the interaction of physical characteristics such as topography, soil erodibility, hydrological connectivity and climate. Robust measurement approaches facilitate the assessment of sediment loss magnitudes in relation to a range of agricultural settings. These approaches improve our understanding of critical sediment transfer periods and inform development of evidence-based and cost-effective management strategies. The aim of this study was to i) assess the efficacy of out-of-channel (ex-situ) suspended sediment measurement approaches, ii) to quantify the variability of sediment exported from five river catchments with varying hydrology and agricultural land uses over multiple years and iii) to investigate trends in relation to physical and land use characteristics when sediment data were compared between catchments. Sediment data were collected in five intensive agricultural river catchments in Ireland (3-11 km2) which featured contrasting land uses (predominantly intensive grassland or arable) and soil drainage classes (well, moderate and poor). High-resolution suspended sediment concentration data (SSC - using a calibrated turbidity proxy) were collected ex-situ and combined with in-stream discharge data measured at each catchment outlet to estimate suspended sediment yield (SSY - t km-2 yr-1). In two catchments additional in-stream turbidity monitoring equipment replicated ex-situ measurements including site specific calibration of individual in-stream and ex-situ turbidity probes. Depth-integrated samples were collected to assess the accuracy of both approaches. Method comparison results showed that true SSC values (from depth-integrated sampling) were predominantly within the 95% confidence interval of ex-situ predicted SSC consequently

  18. Ambiguity Function and Resolution Characteristic Analysis of DVB-S Signal for Passive Radar

    Directory of Open Access Journals (Sweden)

    Jin Wei

    2012-12-01

    Full Text Available This paper gives the performance research on the ambiguity function and resolution of passive radar based on DVB-S (Digital Video Broadcasting-Satellite signal. The radar system structure and signal model of DVB-S signal are firstly studied, then the ambiguity function of DVB-S signal is analyzed. At last, it has been obtained how the bistatic radar position impacts the resolution. Theoretical analyses and computer simulation show that DVB-S signal is applicable as an illuminator for passive radar.

  19. Increased signal intensity on fat-suppressed three-dimensional T1-weighted pulse sequences in patellar tendon: magic angle effect?

    Energy Technology Data Exchange (ETDEWEB)

    Karantanas, A.H.; Zibis, A.H. [CT-MRI Dept., Larissa General Hospital, Larissa (Greece); Papanikolaou, N. [Radiology Dept., University of Crete, Heraklion (Greece)

    2001-02-01

    Objective. To assess the frequency of increased signal intensity in the patellar tendon using three-dimensional T1-weighted MRI pulse sequences. Design and patients. Sixty patients were examined with a 1.0 T scanner (15mT/m gradient strength) using a quadrature coil. Three pulse sequences were applied in the sagittal plane: PD turbo spin echo (PD-TSE), 3D T1-weighted gradient echo with fat suppression (3D-T1-FFE-FS) and 3D T1-weighted echo planar imaging with fat suppression (3D-T1-EPI-FS). The high signal intensity areas were measured in their maximum length. The angle of the patellar tendon relative to the main field position was measured in the same slice. In eight patients with anterior knee pain, and in 11 with no anterior knee pain, a fourth T2-weighted TSE pulse sequence (T2-TSE) was obtained to rule out patellar tendinitis. Results. The correlation of the high signal intensity areas with the relative position of the tendon was found to be significant with the 3D sequences (P=0.03 for 3D-T1-FFE-FS and P=0.003 for 3D-T1-EPI-FS). The length of the high signal intensity area in the tendon was 5.4 mm with 3D-T1-FFE-FS, 4.9 mm with 3D-T1-EPI-FS and 3.1 mm with PD-TSE images. No patellar tendinitis was demonstrated on the T2-TSE images. Conclusion. The magic angle effect is commonly observed in the 3D based T1-weighted pulse sequences with fat suppression. The presence of the above sign must be recognized by radiologists, so that misdiagnosis of patellar tendinitis is avoided. (orig.)

  20. Intravenous injection of gadobutrol in an epidemiological study group did not lead to a difference in relative signal intensities of certain brain structures after 5 years

    Energy Technology Data Exchange (ETDEWEB)

    Kromrey, Marie-Luise; Liedtke, Kim Rouven; Langner, Soenke; Kirsch, Michael; Kuehn, Jens-Peter [University Medicine Greifswald, Institute of Diagnostic Radiology and Neuroradiology, Greifswald (Germany); Ittermann, Till [University Medicine Greifswald, Institute for Community Medicine, Greifswald (Germany); Weitschies, Werner [University Greifswald, Institute of Biopharmacy and Pharmaceutical Technology, Greifswald (Germany)

    2017-02-15

    To investigate if application of macrocyclic gadolinium-based contrast agents in volunteers is associated with neuronal deposition detected by magnetic resonance imaging in a 5-year longitudinal survey. Three hundred eighty-seven volunteers who participated in a population-based study were enrolled. Subjects underwent plain T1-weighted brain MRI at baseline and 5 years later with identical sequence parameters. At baseline, 271 participants additionally received intravenous injection of the macrocyclic contrast agent gadobutrol (1.5 mmol/kg). A control group including 116 subjects received no contrast agent. Relative signal intensities of thalamus, pallidum, pons and dentate nucleus were compared at baseline and follow-up. No difference in relative signal intensities was observed between contrast group (thalamus, p = 0.865; pallidum, p = 0.263; pons, p = 0.533; dentate nucleus, p = 0.396) and control group (thalamus, p = 0.683; pallidum; p = 0.970; pons, p = 0.773; dentate nucleus, p = 0.232) at both times. Comparison between both groups revealed no significant differences in relative signal intensities (thalamus, p = 0.413; pallidum, p = 0.653; pons, p = 0.460; dentate nucleus, p = 0.751). The study showed no significant change in globus pallidus-to-thalamus or dentate nucleus-to-pons ratios. Five years after administration of a 1.5-fold dose gadobutrol to normal subjects, signal intensity of thalamus, pallidum, pons and dentate nucleus did not differ from participants who had not received gadobutrol. (orig.)

  1. Temporal evolution of the CBV-fMRI signal to rat whisker stimulation of variable duration and intensity: a linearity analysis.

    Science.gov (United States)

    Lu, Hanbing; Soltysik, David A; Ward, B Douglas; Hyde, James S

    2005-06-01

    Cerebral blood volume functional magnetic resonance imaging (CBV-fMRI) experiments employing iron oxide contrast agent were conducted in rat whisker barrel cortex at 3 Tesla. Stimuli of constant frequency (12 Hz) but variable duration and intensity were delivered separately using a homemade whisker stimulator. The temporal behavior of CBV-fMRI signals was investigated using a linearity analysis method. Both superposition and scaling tests show that CBV-fMRI responses are generally consistent with a linear time-invariant (LTI) model. In particular, the response to a stimulus of higher intensity can be linearly scaled from that of lower intensity. However, significant deviations exist when the stimulus duration is manipulated, particularly in the trailing edge of the CBV-fMRI response curves.

  2. MR-imaging of finger osteoarthritis: Morphology and cartrilage signal intensity before and after treatment with ademetionin; Magnetresonanztomographie der Fingerpolyarthrose: Morphologie und Knorpelsignalverhalten unter Ademetonintherapie

    Energy Technology Data Exchange (ETDEWEB)

    Koenig, H. [Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, Univ.-Klinikum Steglitz, FU Berlin (Germany); Stahl, H. [Radiologische Klinik, Univ.-Klinikum Rudolf-Virchow, FU Berlin (Germany); Sieper, J. [Medizinische Klinik und Poliklinik, Univ.-Klinikum Steglitz, FU Berlin (Germany); Wolf, K.J. [Radiologische Klinik, Abt. fuer Roentgendiagnostik und Nuklearmedizin, Univ.-Klinikum Steglitz, FU Berlin (Germany)

    1995-01-01

    This report deals with a prospective study of 21 patients with finger osteoarthritis treated over a period of three months with either Ademetionin (therapy group: 14/21) or without (control group: 7/21). MR-Imaging was carried out before and after treatment using spin-echo and 3D-Flash sequences. Morphological parameters and signal intensity changes of the hyaline cartilage were evaluated. The increase of the cartilage signal intensity was significant in the therapy group, this can be interpreted as an structural improvement. Also a decrease of the cartilage signal intensity with age was found. The morphological parameters showed no significant changes in the therapy and control groups. (orig.) [Deutsch] Im Rahmen einer prospektiven Studie wurden magnetresonanztomographische Untersuchungen bei Patientinnen mit Fingerpolyarthrose vor und nach Ademetionintherapie durchgefuehrt. Es erfolgten zwei Messungen an einer Kontrollgruppe (n=7, keine Ademetionintherapie) und an der Therapiegruppe (n=14) im Abstand von drei Monaten. Zur Anwendung kamen eine Doppel-Spin-Echo-Sequenz sowie eine 3D-Flash-Sequenz. Ausgewertet wurden neben morphologischen Parametern auch der Signalintensitaetsverlauf im Bereich des hyalinen Gelenkknorpels der Interphalangealgelenke. Signifikant war der Knorpelsignalzuwachs unter Ademetionintherapie, dies kann als Zeichen einer strukturellen Befundbesserung interpretiert werden. Ebenfalls signifikant zeigte sich die Abnahme der Knorpelsignalintensitaet mit zunehmendem Lebensalter der Patientinnen. Bei den morphologischen Befundaenderungen konnte kein signifikanter Therapieeffekt festgestellt werden. (orig.)

  3. CHARACTERISTIC CORRELATION OF EEG SIGNAL THE MOTOR MOVEMENT TO MEXICAN HAT WAVELET

    OpenAIRE

    ENDRO YULIANTO; Dr.ADHI SUSANTO; Dr.THOMAS SRI WIDODO; Dr.SAMEKTO WIBOWO

    2012-01-01

    A motor movement occurs for the command of brain through neuromuscular channel. Brain Computer Interface (BCI), refers to a system that is able to interpret the brain signal to make human able to have an interaction with environment without a need of neuromuscular channel. Event–Related Synchronization/ Desynchronization (ERS/ERD) is one of EEG signal types that can be used in the system of BCI. The signal occurred as a result of thismotor movement is characterized by a significant increase a...

  4. Clinical Characteristics and Short-Term Outcomes of HIV Patients Admitted to an African Intensive Care Unit

    Directory of Open Access Journals (Sweden)

    Arthur Kwizera

    2016-01-01

    Full Text Available Purpose. In high-income countries, improved survival has been documented among intensive care unit (ICU patients infected with human immune deficiency virus (HIV. There are no data from low-income country ICUs. We sought to identify clinical characteristics and survival outcomes among HIV patients in a low-income country ICU. Materials and Methods. A retrospective cohort study of HIV infected patients admitted to a university teaching hospital ICU in Uganda. Medical records were reviewed. Primary outcome was survival to hospital discharge. Statistical significance was predetermined in reference to P<0.05. Results. There were 101 HIV patients. Average length of ICU stay was 4 days and ICU mortality was 57%. Mortality in non-HIV patients was 28%. Commonest admission diagnoses were Acute Respiratory Distress Syndrome (ARDS (58.4%, multiorgan failure (20.8%, and sepsis (20.8%. The mean Acute Physiologic and Chronic Health Evaluation (APACHE II score was 24. At multivariate analysis, APACHE II (OR 1.24 (95% CI: 1.1–1.4, P=0.01, mechanical ventilation (OR 1.14 (95% CI: 0.09–0.76, P=0.01, and ARDS (OR 4.5 (95% CI: 1.07–16.7, P=0.04 had a statistically significant association with mortality. Conclusion. ICU mortality of HIV patients is higher than in higher income settings and the non-HIV population. ARDS, APACHE II, and need for mechanical ventilation are significantly associated with mortality.

  5. Influence of intensity loss in the cavity of a folded Fabry-Perot interferometer on interferometric signals.

    Science.gov (United States)

    Shyu, Lih-Horng; Chang, Chung-Ping; Wang, Yung-Cheng

    2011-06-01

    Fabry-Perot interferometer is often used for the micro-displacement, because of its common optical path structure being insensitive to the environmental disturbances. Recently, the folded Fabry-Perot interferometer has been investigated for displacement measurements in large ranges. The advantages of a folded Fabry-Perot interferometer are insensitive to the tilt angle and higher optical resolution. But the design of the optical cavity has become more and more complicated. For this reason, the intensity loss in the cavity will be an important parameter for the distribution of the interferometric intensity. To obtain a more accurate result of such interferometer utilized for displacement measurements, the intensity loss of the cavity in the fabricated folded Fabry-Perot interferometer and the modified equation of the folded Fabry-Perot interferometer will be described. According to the theoretical and experimental results, the presented model is available for the analysis of displacement measurements by a folded Fabry-Perot interferometer.

  6. Effects of light sources and intensity on broilers grown to heavy weights. Part 1: growth performance, carcass characteristics, and welfare indices

    Science.gov (United States)

    This study investigated the effects of light sources and light intensity on growth performance, carcass characteristics, and welfare indices of heavy broilers (> 3.0 kg) in 4 trials with 2 replications per trial. A total of 960 1-d-old Ross × Ross 708 chicks (30 males/30 females/room) were randomly ...

  7. Glottal volume velocity waveform characteristics in subjects with and without vocal training, related to gender, sound intensity, fundamental frequency, and age

    NARCIS (Netherlands)

    Sulter, AM; Wit, HP

    1996-01-01

    Glottal volume velocity waveform characteristics of 224 subjects, categorized in four groups according to gender and vocal training, were determined, and their relations to sound-pressure level, fundamental frequency, intra-oral pressure, and age were analyzed. Subjects phonated at three intensity

  8. Investigation of certain characteristics of thinned antenna arrays with digital signal processing

    Science.gov (United States)

    Danilevskii, L. V.; Domanov, Iu. A.; Korobko, O. V.; Tauroginskii, B. I.

    1983-11-01

    A thinned array with correlation processing of input signals is examined. It is shown that amplitude quantization does not change the signal at the thinned-array input as compared with the complete antenna array. The discreteness of time delay causes the thinned and complete arrays to become nonequivalent. Computer-simulation results are presented.

  9. Nonlinear analysis of gravity signals based on estimating attractor topological characteristics

    Science.gov (United States)

    Minervina, H.

    2003-04-01

    The nonlinear dynamical systems (NDSs) and processes with self-organization named as complex systems[1] are investi- gated with great activity in last decades.The gravity phe- nomenon can be also interpreted from the point of view of the self-organization theory first of all as primary irre- versible process [1].The NDS behavior are described on the basis of reconstruction of its attractor in m-dimensional Euclidean state-space and estimation of attractor topolo- gical characteristics(including minimal embedding dimension, scaling factors etc). With this aim it is necessary to select the state-space with the minimal dimension m* as the value m* is an upper limit of the degrees of freedom for a system. The determing m* on the basis of various correlative topological methods requires large computer expenditures [2]. Such methods have essential computational complexity and demand long time series (N is approximatly equal to 10000 - 100000 points) for their implementation. The method proposed in [3]-[5] allows to reduce the compu- tational complexity. However,the proposed locally topolo- gical method has especially heuristic character.This paper gives the theoretical ground of a local-topological method for defining minimal attractor embedding dimension on the basis of proposed matrix series into the state-space [6]. This method requires much less experimental data and is stable to changing m* [3],[5].The investigation of digital gravity signals using local-topological analysis of chaotic attractor trajectories is carried out. For this case we use the geodynamic ground of monotoring for observing variations of gravity field of the Earth on the base of quartz gravi- meters as GNU-KS. The computer confirmation of the theore- tical results is presented. References [1] G.Nicolis and I.Prigogine. Exploring Complexity. W.H.Freeman and Co., New York, 1989. [2] P.Grassberger and I. Procaccia,Characterization of strange attractors, Phys. Rev.Lett. vol.50, 346-349,1983. [3] V

  10. Increased signal intensity of the cochlea on pre- and post-contrast enhanced 3D-FLAIR in patients with vestibular schwannoma

    Energy Technology Data Exchange (ETDEWEB)

    Yamazaki, Masahiro; Naganawa, Shinji; Kawai, Hisashi; Nihashi, Takashi [Nagoya University, Department of Radiology, Graduate School of Medicine, Nagoya (Japan); Fukatsu, Hiroshi [Aichi Medical University Hospital, Department of Medical Informatics, Nagakute (Japan); Nakashima, Tsutomu [Nagoya University, Department of Otorhinolaryngology, Graduate School of Medicine, Nagoya (Japan)

    2009-12-15

    In the vestibular schwannoma patients, the pathophysiologic mechanism of inner ear involvement is still unclear. We investigated the status of the cochleae in patients with vestibular schwannoma by evaluating the signal intensity of cochlear fluid on pre- and post-contrast enhanced thin section three-dimensional fluid-attenuated inversion recovery (3D-FLAIR). Twenty-eight patients were retrospectively analyzed. Post-contrast images were obtained in 18 patients, and 20 patients had the records of their pure-tone audiometry. Regions of interest of both cochleae (C) and of the medulla oblongata (M) were determined on 3D-FLAIR images by referring to 3D heavily T2-weighted images on a workstation. The signal intensity ratio between C and M on the 3D-FLAIR images (CM ratio) was then evaluated. In addition, correlation between the CM ratio and the hearing level was also evaluated. The CM ratio of the affected side was significantly higher than that of the unaffected side (p < 0.001). In the affected side, post-contrast signal elevation was observed (p < 0.005). In 13 patients (26 cochleae) who underwent both gadolinium injection and the pure-tone audiometry, the post-contrast CM ratio correlated with hearing level (p < 0.05). The results of the present study suggest that alteration of cochlear fluid composition and increased permeability of the blood-labyrinthine barrier exist in the affected side in patients with vestibular schwannoma. Furthermore, although weak, positive correlation between post-contrast cochlear signal intensity on 3D-FLAIR and hearing level warrants further study to clarify the relationship between 3D-FLAIR findings and prognosis of hearing preservation surgery. (orig.)

  11. Technology characteristics and concerns arising in the design and fabrication of an entire signal processor using gallium arsenide integrated circuits

    Science.gov (United States)

    Naused, Barbara A.; Samson, Mark L.; Schwab, Daniel J.; Gilbert, Barry K.

    Various GaAs transistor and gate technologies that have been developed since 1980 are analyzed. The characteristics of GaAs logic gates and ICs and the buffered FET logic, Shottky diode FET logic, direct coupled FET logic, and heterojunction integrated injection logic used to implement GaAs gate arrays of LSI complexity are described. The use of digital GaAs in a complex target signal processor, the Advanced Onboard Signal Processor (AOSP), is studied. Data from the testing of GaAs components for the AOSP at the wafer probe, package, and assembled circuit board levels are examined.

  12. A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor

    Directory of Open Access Journals (Sweden)

    Seyed M. A. Salehizadeh

    2015-12-01

    Full Text Available Accurate estimation of heart rates from photoplethysmogram (PPG signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA. The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1 training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2 test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3 Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability

  13. A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor

    Science.gov (United States)

    Salehizadeh, Seyed M. A.; Dao, Duy; Bolkhovsky, Jeffrey; Cho, Chae; Mendelson, Yitzhak; Chon, Ki H.

    2015-01-01

    Accurate estimation of heart rates from photoplethysmogram (PPG) signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR) estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA). The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1) training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2) test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3) Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects) is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability can be

  14. A Novel Time-Varying Spectral Filtering Algorithm for Reconstruction of Motion Artifact Corrupted Heart Rate Signals During Intense Physical Activities Using a Wearable Photoplethysmogram Sensor.

    Science.gov (United States)

    Salehizadeh, Seyed M A; Dao, Duy; Bolkhovsky, Jeffrey; Cho, Chae; Mendelson, Yitzhak; Chon, Ki H

    2015-12-23

    Accurate estimation of heart rates from photoplethysmogram (PPG) signals during intense physical activity is a very challenging problem. This is because strenuous and high intensity exercise can result in severe motion artifacts in PPG signals, making accurate heart rate (HR) estimation difficult. In this study we investigated a novel technique to accurately reconstruct motion-corrupted PPG signals and HR based on time-varying spectral analysis. The algorithm is called Spectral filter algorithm for Motion Artifacts and heart rate reconstruction (SpaMA). The idea is to calculate the power spectral density of both PPG and accelerometer signals for each time shift of a windowed data segment. By comparing time-varying spectra of PPG and accelerometer data, those frequency peaks resulting from motion artifacts can be distinguished from the PPG spectrum. The SpaMA approach was applied to three different datasets and four types of activities: (1) training datasets from the 2015 IEEE Signal Process. Cup Database recorded from 12 subjects while performing treadmill exercise from 1 km/h to 15 km/h; (2) test datasets from the 2015 IEEE Signal Process. Cup Database recorded from 11 subjects while performing forearm and upper arm exercise. (3) Chon Lab dataset including 10 min recordings from 10 subjects during treadmill exercise. The ECG signals from all three datasets provided the reference HRs which were used to determine the accuracy of our SpaMA algorithm. The performance of the SpaMA approach was calculated by computing the mean absolute error between the estimated HR from the PPG and the reference HR from the ECG. The average estimation errors using our method on the first, second and third datasets are 0.89, 1.93 and 1.38 beats/min respectively, while the overall error on all 33 subjects is 1.86 beats/min and the performance on only treadmill experiment datasets (22 subjects) is 1.11 beats/min. Moreover, it was found that dynamics of heart rate variability can be

  15. The correlated characteristics of micro-seismic and electromagnetic radiation signals on a deep blasting workface

    Science.gov (United States)

    Li, Chengwu; Sun, Xiaoyuan; Wang, Chuan; Xu, Xiaomeng; Xie, Beijing; Li, Jing

    2016-12-01

    To date, both micro-seismic (MS) and electromagnetic radiation (EMR) techniques are used as normal, daily safety monitoring tools for coal or rock dynamic disasters in China. In previous studies, these two non-destructive techniques are usually analyzed independently; few works have been done to characterize the correlation or difference between them. This paper aims to analyze the correlated features of the MS and EMR signals obtained from a field site test on a deep blasting workface in Pingdingshan 10# coal colliery. The de-noised signals are firstly compared for their associated features, both in time synchronization and energy correlation, and then the mechanism for the correlated response is also investigated. The results show that: (1) MS and EMR signals have a higher time-synchronization and energy correlation. (2) The EMR signal in a blasting operation is a local signal, near to the location of the detectors. (3) The two orthogonal layout magnetic antennas (along the roadway and vertical to the coal wall) can detect a single pulse signal and group-occurring cluster signals. These two kinds of EMR signals result from coal crack evolution and resistance-capacitance (RC) oscillation circuits respectively, which are triggered by seismic longitudinal waves. (4) The seismic transverse wave, especially for the low frequency component of it, makes a rubbing friction effect on coal, producing a low-frequency electromagnetic oscillation signal. Affected by the power and propagation direction of the energy, the signal can only be captured by the antenna in the vertical direction of the coal wall.

  16. Compared propagation characteristics of superluminal and slow light in SOA and EDFA based on rectangle signals

    Science.gov (United States)

    Wang, Fu; Wang, Zhi; Wu, Chongqing; Sun, Zhenchao; Mao, Yaya; Liu, Lanlan; Li, Qiang

    2015-10-01

    Based on the general mechanism of the coherent population oscillations (CPO) in the Semiconductor optical amplifiers (SOA) and Erbium doped fiber amplifiers (EDFA), the group time delay of rectangle signal propagating in the active media is deduced. Compared with the sinusoidal signal, the time delay difference between the fundamental harmonics (FHFD: fundamental harmonic fractional delay) is first investigated in detail for the rectangle signal which is more popularly used in the digital signal systems. The plenty of simulations based on the propagation equations and some experiments for the sinusoidal and rectangle signals are used to analyze the differences and evaluate the slow and superluminal light effects. Furthermore, the time delay/advance always takes place accompanying with the signal distortion, which is evaluated by the total harmonic distortion (THD). The distortion caused by the SOA is smaller than that by the EDFA. A factor Q which is defined to evaluate the trade-off between the FHFD and the THD, shows that higher input power or higher optical gain is better for optical signal processing and optical telecommunications, and the SOA is more suitable for the higher modulation frequency (>10 GHz).

  17. Numerical modelling of the pump-to-signal relative intensity noise transfer in two-pump fibre optical parametric amplifiers

    Indian Academy of Sciences (India)

    H Pakarzadeh; A Zakery

    2011-10-01

    An accurate numerical model to investigate the pump-to-signal relative intensity noise (RIN) transfer in two-pump fibre optical parametric amplifiers (2-P FOPAs) for low modulation frequencies is presented. Compared to other models in the field, this model takes into account the fibre loss, pump depletion as well as the gain saturation. As a result, the model allows to include a wide range of practical circumstances, both in and beyond the undepleted pump regime, related to different applications of FOPAs. In the small-signal or undepleted pump regime, the model predicts the ripples of the RIN spectrum very well and yields better results than those of other models. It is shown that beyond the small-signal regime, pump power variations do not remain unchanged over the length of the amplifier and for high signal powers, when the FOPA saturates, minimum pump-to-signal RIN transfer occurs. The results of the model are also compared with the available experimental data in the field and a very good agreement can be seen.

  18. Demonstration of 48-Gb/s 16-QAM signal transmission using half cycle sub-carrier modulation in intensity modulation/direct detection system

    Science.gov (United States)

    Tang, Jin; He, Jing; Chen, Ming; Li, Danyu; Chen, Lin

    2015-01-01

    A simple spectral-efficiency intensity modulation/direct detection (IM/DD) system based on half cycle sub-carrier modulation (SCM) signal is proposed for short reach fiber communications in this paper. The signal impairment of frequency selective fading due to fiber chromatics dispersion (CD) is mathematically analyzed. To reduce the performance deterioration caused by the non-flat transfer function, digital pre- and post-equalization is applied in the system. The peak to average power ratio (PAPR) of the signal is also discussed in comparison with that of orthogonal frequency division multiplexing (OFDM). The transmission of 16-QAM half cycle SCM signal with a sub-carrier frequency of half the symbol rate and Nyquist pulse shaping is experimentally demonstrated. The bit-error rate (BER) of 48 Gb/s polarization multiplexing division (PDM) 16 QAM half cycle SCM signal is less than 7% forward-error-correction (FEC) threshold of 3.8 ×10-3 after transmission over 83 km standard single-mode fiber (SSMF).

  19. Acute low-intensity cycling with blood-flow restriction has no effect on metabolic signaling in human skeletal muscle compared to traditional exercise.

    Science.gov (United States)

    Smiles, William J; Conceição, Miguel S; Telles, Guilherme D; Chacon-Mikahil, Mara P T; Cavaglieri, Cláudia R; Vechin, Felipe C; Libardi, Cleiton A; Hawley, John A; Camera, Donny M

    2017-02-01

    Autophagy is an intracellular degradative system sensitive to hypoxia and exercise-induced perturbations to cellular bioenergetics. We determined the effects of low-intensity endurance-based exercise performed with blood-flow restriction (BFR) on cell signaling adaptive responses regulating autophagy and substrate metabolism in human skeletal muscle. In a randomized cross-over design, nine young, healthy but physically inactive males completed three experimental trials separated by 1 week of recovery consisting of either a resistance exercise bout (REX: 4 × 10 leg press repetitions, 70% 1-RM), endurance exercise (END: 30 min cycling, 70% VO2peak), or low-intensity cycling with BFR (15 min, 40% VO2peak). A resting muscle biopsy was obtained from the vastus lateralis 2 weeks prior to the first exercise trial and 3 h after each exercise bout. END increased ULK1(Ser757) phosphorylation above rest and BFR (~37 to 51%, P exercise-induced changes in select markers of autophagy following BFR. Genes implicated in substrate metabolism (HK2 and PDK4) were increased above rest (~143 to 338%) and BFR cycling (~212 to 517%) with END (P < 0.001). A single bout of low-intensity cycling with BFR is insufficient to induce intracellular "stress" responses (e.g., high rates of substrate turnover and local hypoxia) necessary to activate skeletal muscle autophagy signaling.

  20. Using physicochemical and compositional characteristics of DNA sequence for prediction of genomic signals

    KAUST Repository

    Mulamba, Pierre Abraham

    2014-12-01

    The challenge in finding genes in eukaryotic organisms using computational methods is an ongoing problem in the biology. Based on various genomic signals found in eukaryotic genomes, this problem can be divided into many different sub­‐problems such as identification of transcription start sites, translation initiation sites, splice sites, poly (A) signals, etc. Each sub-­problem deals with a particular type of genomic signals and various computational methods are used to solve each sub-­problem. Aggregating information from all these individual sub-­problems can lead to a complete annotation of a gene and its component signals. The fundamental principle of most of these computational methods is the mapping principle – building an input-­output model for the prediction of a particular genomic signal based on a set of known input signals and their corresponding output signal. The type of input signals used to build the model is an essential element in most of these computational methods. The common factor of most of these methods is that they are mainly based on the statistical analysis of the basic nucleotide sequence string composition. 4 Our study is based on a novel approach to predict genomic signals in which uniquely generated structural profiles that combine compressed physicochemical properties with topological and compositional properties of DNA sequences are used to develop machine learning predictive models. The compression of the physicochemical properties is made using principal component analysis transformation. Our ideas are evaluated through prediction models of canonical splice sites using support vector machine models. We demonstrate across several species that the proposed methodology has resulted in the most accurate splice site predictors that are publicly available or described. We believe that the approach in this study is quite general and has various applications in other biological modeling problems.

  1. Increased intensity and reduced frequency of EMG signals from feline self-reinnervated ankle extensors during walking do not normalize excessive lengthening.

    Science.gov (United States)

    Pantall, Annette; Hodson-Tole, Emma F; Gregor, Robert J; Prilutsky, Boris I

    2016-06-01

    Kinematics of cat level walking recover after elimination of length-dependent sensory feedback from the major ankle extensor muscles induced by self-reinnervation. Little is known, however, about changes in locomotor myoelectric activity of self-reinnervated muscles. We examined the myoelectric activity of self-reinnervated muscles and intact synergists to determine the extent to which patterns of muscle activity change as almost normal walking is restored following muscle self-reinnervation. Nerves to soleus (SO) and lateral gastrocnemius (LG) of six adult cats were surgically transected and repaired. Intramuscular myoelectric signals of SO, LG, medial gastrocnemius (MG), and plantaris (PL), muscle fascicle length of SO and MG, and hindlimb mechanics were recorded during level and slope (±27°) walking before and after (10-12 wk postsurgery) self-reinnervation of LG and SO. Mean myoelectric signal intensity and frequency were determined using wavelet analysis. Following SO and LG self-reinnervation, mean myoelectric signal intensity increased and frequency decreased in most conditions for SO and LG as well as for intact synergist MG (P myoelectric activity of self-reinnervated SO and LG are discussed.

  2. Local influence of south-east France topography and land cover on the distribution and characteristics of intense rainfall cells

    Science.gov (United States)

    Renard, Florent

    2017-04-01

    The Greater Lyon area is strongly built up, grouping 58 communes and a population of 1.3 million in approximately 500 km2. The flood risk is high as the territory is crossed by two large watercourses and by streams with torrential flow. Floods may also occur in case of runoff after heavy rain or because of a rise in the groundwater level. The whole territory can therefore be affected, and it is necessary to possess in-depth knowledge of the depths, causes and consequences of rainfall to achieve better management of precipitation in urban areas and to reduce flood risk. This study is thus focused on the effects of topography and land cover on the occurrence, intensity and area of intense rainfall cells. They are identified by local radar meteorology (C-band) combined with a processing algorithm running in a geographic information system (GIS) which identified 109,979 weighted mean centres of them in a sample composed of the five most intense rainfall events from 2001 to 2005. First, analysis of spatial distribution at an overall scale is performed, completed by study at a more detailed scale. The results show that the distribution of high-intensity rainfall cells is spread in cluster form. Subsequently, comparison of intense rainfall cells with the topography shows that cell density is closely linked with land slope but that, above all, urbanised zones feature nearly twice as many rainfall cells as farm land or forest, with more intense intensity.

  3. Analysis of the Effect of the Swirl Flow Intensity on Combustion Characteristics in Liquid Fuel Powered Confined Swirling Flames

    Directory of Open Access Journals (Sweden)

    Marko Klancisar

    2016-01-01

    Full Text Available This article examines the implementation of CFD technology in the design of the industrial liquid fuel powered swirl flame burner. The coupling between the flow field and the combustion model is based on the eddy dissipation model. The choice of the LES (Large Eddy Simulation turbulence model over standard RANS (Reynolds Averaged Navier-Stokes offers a possibility to improve the quality of the combustion-flow field interaction. The Wall Adapting Local Eddy-Viscosity (WALE sub-grid model was used. The reaction chemistry is a simple infinitely fast one step global irreversible reaction. The computational model was setup with the Ansys-CFX software. Through the detailed measurements of industrial size burner, it was possible to determine the natural operational state of the burner according to the type of fuel used. For the inlet conditions, axial and radial velocity components were calculated from known physical characteristics of both the fuel and air input, with the initial tangential velocity of the fuel assumed as18% of the initial axial fuel velocity. Different swirl number (S values were studied. Addition of a surplus (in comparison to conventional flame stabilization of tangential air velocity component (W, the rotational component increases itself with a considerably high magnitude, contributing to the overall flame stabilization. The level of S especially influences the turbulent energy, its dissipation rate and turbulent (Reynolds stresses. In the case of high swirl number values (S > 0,65 it is possible to divide the flow field in three principle areas: mixing area (fuel-air, where exothermal reactions are taking place, central recirculation area and outer recirculation area, which primarily contains the flow of burnt flue gases. The described model was used to determine the flow and chemical behavior, whereas the liquid atomization was accounted for by LISA (Linear Instability Sheet Atomization model incorporating also the cavitation

  4. Effects of light radiation intensity on photosynthetic characteristics and water use efficiency of Platycladus orientalis and Pinus tabulaeformis seedlings

    Institute of Scientific and Technical Information of China (English)

    ZHANG Weiqiang; HE Kangning; WANG Yunqi; WANG Baitian; DENG Juntao; ZHOU Yi; ZHONG Xijun; LI Zhaoqing

    2007-01-01

    In order to offer a scientific basis for cultivation and management of forests,effects of light radiation intensity on photosynthetic characteristics and water use efficiency of Platycladus orientalis and Pinus tabulaeformis were studied under different soil moisture contents.By adopting artificial control methods to soil moisture,and under simulated photosynthetic radiation (SPR),the net photosynthetic rate (PN),transpiration rate (Tr),water use efficiency (WUE) and intercellular CO2 concentration (Ci,) of Platycladus orientalis and Pinus tabulaeformis in the semi-arid region of the Loess Plateau,were studied.Results are as follows:within the photon range of 0-2,200 μmol/(m2·s),PN,Tr and WUE were enhanced with an increase in SPR in both species.PN and WUE of Platycladus orientalis and Pinus tabulaeformis,however,declined with continued increase in SPR.PN,Tr,WUE and light saturation point (LSP) of Platycladus orientalis were higher than those of Pinus tabulaeformis,while light compensation point (LCP) of Platycladus orientalis was lower than that of Pinus tabulaeformis at the same soil moisture content.The efficiency of light energy utilization of Platycladus orientalis was higher than that of Pinus tabulaeformis;PN,Tr and Ci of Platycladus orientalis and Pinus tabulaeformis were enhanced by increasing soil moisture content,whereas WUE declined.At soil moistures of 7.90%,13.00% and 19.99%,LSP of Platycladus orientalis LCP was 42,25 and 13 μmol/(m2·s) respectively,with corresponding maximal net CO2 photosynthetic rates (Pmax)of 3.04,4.06 and 5.53 μmol(m2·s).At soil moistures of 7.83%,13.04% and 20.15%, the LSP of Pinus tabulaeformis was 1,100, 1,325 and 1,500 μmol/(m2·s) respectively and LCP was 60,30 and 23μmol/(m2·s), with Pmas of 1.08, 3.35 and 4.36 μmol/(m2·s)respectively.

  5. Characteristics of turn signal use at intersections in baseline naturalistic driving.

    Science.gov (United States)

    Sullivan, John M; Bao, Shan; Goudy, Roy; Konet, Heather

    2015-01-01

    The purpose of this study was to determine whether a driver's use of turn signals is sufficiently reliable to forecast a vehicle's future path around an intersection, when detailed information about the intersection is unavailable. Naturalistic observations of turn signal use among 108 drivers on surface streets were extracted from the baseline portion of a field operational test of a safety system. Left and right turns that resulted in heading changes of between 70 and 110° and turn radii between 18 and 90 m were selected from the dataset. The odds that a driver would signal a turn were modeled as a function of road type, turn direction, presence of a forward vehicle, whether the vehicle stopped before the turn, and driver age and gender. Overall, 25 percent of left turns and 29 percent of right turns were not signaled. Road type, turn direction, and presence of a forward vehicle were found to influence the odds that a turn is signaled, while gender and age of the driver did not. The results suggest that situational factors like road type and turn direction are more powerful predictors of whether a turn will be signaled than either age or gender. Signaling on major and minor surface roads was about 5 times more likely than on local roads and 1.5 times more likely when a forward vehicle was present, suggesting a possible effect of traffic volume. It was concluded that turn signal activation alone may be insufficiently reliable to forecast a driver's path. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Higher methylation intensity induced by EBV LMP1 via NF-κB/DNMT3b signaling contributes to silencing of PTEN gene

    Science.gov (United States)

    Lyu, Xiaoming; Jiang, Qiang; Wang, Jianguo; Lu, Juan; Yao, Kaitai; Liu, Kunping; Li, Jinbang; Li, Xin

    2016-01-01

    Phosphatase and tensin homolog (PTEN) is a major tumor suppressor and usually silenced via the deletion, insertion and mutation. We previously discovered its inactivation via aberrant CpG island methylation. Here, we provide further evidence that EBV latent membrane protein 1(LMP1) can induce a higher intensity of DNA methylation at PTEN CpG islands, inactivating PTEN at the cellular and molecular level. Initially, increased methylation intensity of PTEN CpG islands was observed in EBV-infected nasopharyngeal carcinoma (NPC) cells, accompanied by decreased PTEN expression. In NPC tissue samples showing the methylation at PTEN promoter, LMP1 was highly expressed in higher methylation intensity group relative to lower intensity group, and DNA methyltransferase 3b (DNMT3b) expression was positively correlated with LMP1 expression. Moreover, transfection of LMP1 gene into EBV-negative NPC cells demonstrated that LMP1 up-regulated DNMT3b expression, leading to a higher intensity of PTEN CpG island methylation. Mechanistically, computational prediction and luciferase reporter assay identified a functional NF-κB binding site on DNMT3b promoter and the mutated NF-κB binding site abolished LMP1-mediated DNMT3b activation. Chromatin immunoprecipitation displayed that NF-κB p65 subunit constitutively bound to DNMT3b promoter, supporting the activation of DNMT3b by EBV LMP1 via NF-κB signaling. Furthermore, the expression level of DNMT3b was observed to be increased in the nuclei of LMP1-expressing NPC cells, and a NF-κB inhibitor, PDTC, counteracted LMP1-mediated DNMT3b overexpression. Thus, this study first reports that LMP1-mediated NF-κB can up-regulate DNMT3b transcription, thereby leading to relatively higher methylation intensity at PTEN CpG islands, and ultimately silencing major tumor suppressor PTEN. PMID:27223069

  7. Higher methylation intensity induced by EBV LMP1 via NF-κB/DNMT3b signaling contributes to silencing of PTEN gene.

    Science.gov (United States)

    Peng, Hong; Chen, Yuxiang; Gong, Pinggui; Cai, Longmei; Lyu, Xiaoming; Jiang, Qiang; Wang, Jianguo; Lu, Juan; Yao, Kaitai; Liu, Kunping; Li, Jinbang; Li, Xin

    2016-06-28

    Phosphatase and tensin homolog (PTEN) is a major tumor suppressor and usually silenced via the deletion, insertion and mutation. We previously discovered its inactivation via aberrant CpG island methylation. Here, we provide further evidence that EBV latent membrane protein 1(LMP1) can induce a higher intensity of DNA methylation at PTEN CpG islands, inactivating PTEN at the cellular and molecular level. Initially, increased methylation intensity of PTEN CpG islands was observed in EBV-infected nasopharyngeal carcinoma (NPC) cells, accompanied by decreased PTEN expression. In NPC tissue samples showing the methylation at PTEN promoter, LMP1 was highly expressed in higher methylation intensity group relative to lower intensity group, and DNA methyltransferase 3b (DNMT3b) expression was positively correlated with LMP1 expression. Moreover, transfection of LMP1 gene into EBV-negative NPC cells demonstrated that LMP1 up-regulated DNMT3b expression, leading to a higher intensity of PTEN CpG island methylation. Mechanistically, computational prediction and luciferase reporter assay identified a functional NF-κB binding site on DNMT3b promoter and the mutated NF-κB binding site abolished LMP1-mediated DNMT3b activation. Chromatin immunoprecipitation displayed that NF-κB p65 subunit constitutively bound to DNMT3b promoter, supporting the activation of DNMT3b by EBV LMP1 via NF-κB signaling. Furthermore, the expression level of DNMT3b was observed to be increased in the nuclei of LMP1-expressing NPC cells, and a NF-κB inhibitor, PDTC, counteracted LMP1-mediated DNMT3b overexpression. Thus, this study first reports that LMP1-mediated NF-κB can up-regulate DNMT3b transcription, thereby leading to relatively higher methylation intensity at PTEN CpG islands, and ultimately silencing major tumor suppressor PTEN.

  8. Cellular Levels of Signaling Factors Are Sensed by β-actin Alleles to Modulate Transcriptional Pulse Intensity

    Directory of Open Access Journals (Sweden)

    Alon Kalo

    2015-04-01

    Full Text Available The transcriptional response of β-actin to extra-cellular stimuli is a paradigm for transcription factor complex assembly and regulation. Serum induction leads to a precisely timed pulse of β-actin transcription in the cell population. Actin protein is proposed to be involved in this response, but it is not known whether cellular actin levels affect nuclear β-actin transcription. We perturbed the levels of key signaling factors and examined the effect on the induced transcriptional pulse by following endogenous β-actin alleles in single living cells. Lowering serum response factor (SRF protein levels leads to loss of pulse integrity, whereas reducing actin protein levels reveals positive feedback regulation, resulting in elevated gene activation and a prolonged transcriptional response. Thus, transcriptional pulse fidelity requires regulated amounts of signaling proteins, and perturbations in factor levels eliminate the physiological response, resulting in either tuning down or exaggeration of the transcriptional pulse.

  9. Carotid artery stenosis with a high-intensity signal plaque on time-of-flight magnetic resonance angiography and association with evidence of intraplaque hypoxia.

    Science.gov (United States)

    Ogata, Atsushi; Kawashima, Masatou; Wakamiya, Tomihiro; Nishihara, Masashi; Masuoka, Jun; Nakahara, Yukiko; Ebashi, Ryo; Inoue, Kohei; Takase, Yukinori; Irie, Hiroyuki; Abe, Tatsuya

    2017-06-01

    OBJECTIVE Hypoxia induces angiogenesis and plays a major role in the progression of carotid plaques. During carotid intervention, plaques with high-intensity signals on time-of-flight (TOF) magnetic resonance angiography (MRA) often cause ischemic stroke and embolic complications. However, the role of intraplaque hypoxia before carotid endarterectomy (CEA) and carotid artery stenting is not presently understood. In this study the authors aimed to investigate the relationship between intraplaque hypoxia and MRA findings. METHODS Nineteen consecutive patients with 20 carotid artery stenoses who underwent CEA at Saga University Hospital between August 2008 and December 2014 were enrolled in the study. The expressions of hypoxia-inducible transcription factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) were analyzed by immunohistochemical analysis. In addition, the relationship between the findings on TOF MRA and pathology for the carotid plaques was analyzed. RESULTS High-intensity plaques on TOF MRA showed higher expression levels of HIF-1α (p = 0.015) and VEGF (p = 0.007) compared with isointensity plaques. The rate of intraplaque hemorrhage (IPH) on TOF MRA was also significantly higher in the high-intensity plaques than in the isointensity plaques (p = 0.024). Finally, the mean number of neovessels was significantly higher in those without plaque hemorrhage than in those with plaque hemorrhage (p = 0.010). CONCLUSIONS Plaques with high-intensity signals on TOF MRA were associated with IPH and evidence of intraplaque hypoxia. This fact may represent an opportunity to establish novel therapeutic agents targeting intraplaque hypoxia.

  10. High-intensity high-volume swimming induces more robust signaling through PGC-1α and AMPK activation than sprint interval swimming in m. triceps brachii

    DEFF Research Database (Denmark)

    Casuso, Rafael A; Plaza-Díaz, Julio; Ruiz-Ojeda, Francisco J

    2017-01-01

    We aimed to test whether high-intensity high-volume training (HIHVT) swimming would induce more robust signaling than sprint interval training (SIT) swimming within the m. triceps brachii due to lower metabolic and oxidation. Nine well-trained swimmers performed the two training procedures...... on separate randomized days. Muscle biopsies from m. triceps brachii and blood samples were collected at three different time points: a) before the intervention (pre), b) immediately after the swimming procedures (post) and c) after 3 h of rest (3 h). Hydroperoxides, creatine kinase (CK), and lactate...

  11. Effects of resistance exercise intensity on extracellular signal-regulated kinase 1/2 mitogen-activated protein kinase activation in men.

    Science.gov (United States)

    Taylor, Lem W; Wilborn, Colin D; Kreider, Richard B; Willoughby, Darryn S

    2012-03-01

    Extracellular signal-regulated kinase (ERK) 1/2 signaling has been shown to be increased after heavy resistance exercise and suggested to play a role in the hypertrophic adaptations that are known to occur with training. However, the role that ERK1/2 may play in response to lower intensities of resistance exercise is unknown. Therefore, the purpose of this study was to determine the effects of resistance exercise intensity on ERK1/2 activity in human skeletal muscle. Twelve recreationally active men completed separate bouts of single-legged resistance exercise with 8-10 repetitions (reps) at 80-85% 1 repetition maximum (1RM) (85%) and 18-20 reps at 60-65% 1RM (65%) in a randomized crossover fashion. For both resistance exercise sessions, vastus lateralis biopsies and blood draws were taken immediately before exercise (PRE) and at 30 minutes (30MPST), 2 hours (2HRPST), and 6 hours (6HRPST) post exercise, with an additional blood draw occurring immediately after exercise (POST). The phosphorylated levels of pIGF-1R, pMEK1, pERK1/2, and activated Elk-1 were assessed by phosphoELISA, and serum insulin-like growth factor 1 (IGF-1) was assessed via enzyme-linked immunosorbent assay. Statistical analyses used a 2 × 4 (muscle responses) and 2 × 5 (serum responses) multivariate analysis of variance on delta values from baseline (p < 0.05). Both exercise intensities significantly increased the activity of insulin-like growth factor 1 receptor (IGF-1R), mitogen-activated protein kinase 1, ERK1/2, and Elk-1, with peak activity occurring at 2HRPST (p < 0.001). However, 65% resulted in a preferential increase in IGF-1R and Elk-1 activation when compared with 85% (p < 0.05). No differences were observed for serum IGF-1 levels regardless of intensity and time. These findings demonstrate that resistance exercise upregulates ERK1/2 signaling in a manner that does not appear to be preferentially dependent on exercise intensity.

  12. Phase-noise characteristics of a 25-GHz-spaced optical frequency comb based on a phase- and intensity-modulated laser.

    Science.gov (United States)

    Ishizawa, Atsushi; Nishikawa, Tadashi; Mizutori, Akira; Takara, Hidehiko; Takada, Atsushi; Sogawa, Tetsuomi; Koga, Masafumi

    2013-12-02

    We investigated phase-noise characteristics of both a phase/intensity-modulated laser with 25-GHz mode spacing and a mode-locked fiber laser with carrier-envelope-offset (CEO) locking. As the separation from the frequency of the continuous wave (CW) laser diode (LD) for a seed light source increases, the integrated phase noise of each comb mode of both the phase/intensity-modulated laser and supercontinuum light originating from it increases with the same slope as a function of mode number. The dependence of the integrated phase noise on mode number with the phase/intensity-modulated laser is much larger than with the mode-locked fiber laser of the CEO locking. However, the phase noise of the phase/intensity-modulated laser is extremely lower than that of the mode-locked fiber laser with CEO locking in the frequency region around the CW LD. The phase noise of the phase/intensity-modulated laser with 25-GHz mode spacing and that of the mode-locked fiber laser with the CEO locking could be estimated and were found to be almost the same at the wavelengths required in an f-to-2f self-referencing interferometer. Our experimental results indicate the possibility of achieving an offset-frequency-locked frequency comb with the phase/intensity-modulated laser.

  13. Experimental Investigation on Propagation Characteristics of PD Radiated UHF Signal in Actual 252 kV GIS

    Directory of Open Access Journals (Sweden)

    Tianhui Li

    2017-07-01

    Full Text Available For partial discharge (PD diagnostics in gas insulated switchgears (GISs based on the ultra-high-frequency (UHF method, it is essential to study the attenuation characteristics of UHF signals so as to improve the application of the UHF technique. Currently, the performance of UHF has not been adequately considered in most experimental research, while the constructive conclusions about the installation and position of UHF sensors are relatively rare. In this research, by using a previously-designed broadband sensor, the output signal is detected and analyzed experimentally in a 252 kV GIS with L-shaped structure and disconnecting switch. Since the relative position of the sensor and the defect is usually fixed by prior research, three circumferential angle positions of the defect in cross section are performed. The results are studied by time, statistics and frequency analyses. This identifies that the discontinuity conductor of DS will lead to a rise of both the peak to peak value (Vpp and the transmission rate of the UHF signal. Then, the frequency analysis indicates that the reason for the distinction of signal amplitude and transmission rate is that the mode components of the PD signal are distinctively affected by the special structure of GIS. Finally, the optimal circumferential angle position of the UHF Sensor is given based on the comparison of transmission rates.

  14. Correlation of non-mass-like abnormal MR signal intensity with pathological findings surrounding pediatric osteosarcoma and Ewing's sarcoma

    Energy Technology Data Exchange (ETDEWEB)

    Masrouha, Karim Z.; Haidar, Rachid; Saghieh, Said [American University of Beirut Medical Center, Department of Surgery, Beirut (Lebanon); Musallam, Khaled M. [American University of Beirut Medical Center, Internal Medicine Division of Hematology and Oncology, Beirut (Lebanon); Samra, Alexis Bou; Tawil, Ayman; Chakhachiro, Zaher [American University of Beirut Medical Center, Pathology, Beirut (Lebanon); Abdallah, Abeer; Khoury, Nabil J. [American University of Beirut Medical Center, Diagnostic Radiology, Beirut (Lebanon); Saab, Raya; Muwakkit, Samar; Abboud, Miguel R. [American University of Beirut Medical Center, Children' s Cancer Center of Lebanon, Beirut (Lebanon)

    2012-11-15

    The aim of this work was to determine the role of MRI in interpreting abnormal signals within bones and soft tissues adjacent to tumor bulk of osteosarcoma and Ewing's sarcoma in a pediatric population by correlating MR findings with histopathology. Thirty patients met the inclusion criteria, which included (1) osteosarcoma or Ewing's sarcoma, (2) MR studies no more than 2 months prior to surgery, (3) presence of abnormal MR signal surrounding the tumor bulk, (4) pathological material from resected tumor. The patients received standard neoadjuvant chemotherapy. Using grid maps on gross pathology specimens, the abnormal MR areas around the tumor were matched with the corresponding grid sections. Histopathology slides of these sections were then analyzed to determine the nature of the regions of interest. The MR/pathological correlation was evaluated using Mann-Whitney U test and Fisher's exact test. Twenty-seven patients had osteosarcoma and three patients had Ewing's sarcoma. Of the studied areas, 17.4% were positive for tumor (viable or necrotic). There was no statistically significant correlation between areas positive for tumor and age, gender, signal extent and intensity on MRI, or tissue type. There was, however, a statistically significant correlation between presence of tumor and the appearance of abnormal soft tissue signals. A feathery appearance correlated with tumor-negative areas whereas a bulky appearance correlated with tumor-positive regions. MR imaging is helpful in identifying the nature of abnormal signal areas surrounding bone sarcomas that are more likely to be tumor-free, particularly when the signal in the soft tissues surrounding the tumor is feathery and edema-like in appearance. (orig.)

  15. Kinetic characteristics and modeling of microalgae Chlorella vulgaris growth and CO2 biofixation considering the coupled effects of light intensity and dissolved inorganic carbon.

    Science.gov (United States)

    Chang, Hai-Xing; Huang, Yun; Fu, Qian; Liao, Qiang; Zhu, Xun

    2016-04-01

    Understanding and optimizing the microalgae growth process is an essential prerequisite for effective CO2 capture using microalgae in photobioreactors. In this study, the kinetic characteristics of microalgae Chlorella vulgaris growth in response to light intensity and dissolved inorganic carbon (DIC) concentration were investigated. The greatest values of maximum biomass concentration (Xmax) and maximum specific growth rate (μmax) were obtained as 2.303 g L(-1) and 0.078 h(-1), respectively, at a light intensity of 120 μmol m(-2) s(-1) and DIC concentration of 17 mM. Based on the results, mathematical models describing the coupled effects of light intensity and DIC concentration on microalgae growth and CO2 biofixation are proposed. The models are able to predict the temporal evolution of C. vulgaris growth and CO2 biofixation rates from lag to stationary phases. Verification experiments confirmed that the model predictions agreed well with the experimental results.

  16. Stimulus-Evoked Intrinsic Optical Signals in the Retina: Spatial and Temporal Characteristics

    NARCIS (Netherlands)

    Schallek, Jesse; Li, Hongbin; Kardon, Randy; Kwon, Young; Abramoff, Michael

    2009-01-01

    purpose. To characterize the properties of stimulus-evoked retinal intrinsic signals and determine the underlying origins. methods. Seven adult cats were anesthetized and paralyzed to maximize imaging stability. The retina was stimulated with a liquid crystal display (LCD) integrated into a modifi

  17. Effects of Light Intensity on the Growth, Photosynthetic Characteristics, and Flavonoid Content of Epimedium pseudowushanense B.L.Guo

    Directory of Open Access Journals (Sweden)

    Junqian Pan

    2016-11-01

    Full Text Available Epimedium pseudowushanense B.L.Guo is used in traditional medicine as an aphrodisiac and to strengthen muscles and bones. Several recent reports have shown that flavonoids from Epimedium also significantly affect the treatment of breast cancer, liver cancer, and leukemia. However, few studies have examined the medicinal-ingredient yield of Epimedium, a light-demanding shade herb, under different light intensities. To investigate the effects of light intensity on medicinal-ingredient yields, Epimedium was exposed to five levels of light intensity until harvest time. Leaf dry biomass under L4 was the highest among different light treatments. L4 was also associated with the highest net photosynthetic rate. Quantification of epimedin A, epimedin B, epimedin C, and icariin showed that L3 produced the highest amount of epimedin C, and that flavonoid content responded to light levels differently. Results indicated that L3 and L4 were the optimal light levels for medicinal-ingredient yield.

  18. [Characteristics of soil phosphorus runoff under different rainfall intensities in the typical vegetable plot of Taihu Basin].

    Science.gov (United States)

    Yang, Li-Xia; Yang, Gui-Shan; Yuan, Shao-Feng; Wu, Ye

    2007-08-01

    Experiments of field runoff plots, which were conducted at vegetable plots in Hongsheng town of Wuxi city--the typical region of Taihu Basin, were designed to assess the effects of different rainfall intensities on soil phosphorus runoff loss from vegetable plots by artificial rainfall simulations. Results showed that there was a relationship of power function between initial runoff-generation time and rainfall intensity. Runoff amount slowly increased under small rainfall intensity, but rapidly increased with rainfall intensity increase. The concentrations of total phosphorus (TP) and particulate phosphorus (PP) were higher at the early stage, then gradually decreased with time and finally reached a comparative steady stage under 0.83, 1.17 and 1.67 mm x min(-1). However they indicated no obvious trend except wavy undulation under 2.50 mm x min(-1). In the course of rainfall-runoff, dissolved phosphorus (DP) gently varied and accounted for 20% - 32% of TP. PP was 68% - 80% of TP and its change trend was consistent with TP. Therefore, PP was main loss form of soil phosphorus runoff. Comparison of different phosphorous loss rate under different rainfall intensities suggested that loss rate of TP and DP under 2.50 mm x min(-1) was 20 times and 33 times higher than that under 0.83 mm x min(-1), which showed that loss rate of PP and DP increased with the increase of rainfall intensities. Results indicated that lots of inorganic dissolved phosphorus (DIP) of phosphorous fertilizer was discharged into water environment by using fertilizer in soil surface before rainfall, which increased loss of DP and greatly aggravated degree of water eutrophication.

  19. Purification and Concentration of PCR Products Leads to Increased Signal intensities with Fewer Allelic Drop-Outs and Artifacts

    DEFF Research Database (Denmark)

    Maria Irlund Pedersen, Line; Stangegaard, Michael; Mogensen, Helle Smidt

    2011-01-01

    Capillary electrophoresis of amplified DNA isolated from trace evidence samples occasionally results in inadequate STR-profiles due to artifacts caused by e.g. primers and dNTPs. Removal of artifacts by purification and subsequent concentration of the PCR products may increase the sensitivity...... and the quality of the DNA profiles without re-amplification of the sample. We have validated and implemented an automated method to purify and 2-fold concentrate PCR products resulting in allelic peaks with higher intensity (a median height across all loci from 130 to 404 RFU), fewer allelic dropouts...... and a reduced number of artifacts compared to both an increase in injection time and increase in the number of amplification cycles....

  20. Characteristics and performance of an intensity-modulated optically pumped magnetometer in comparison to the classical M(x) magnetometer.

    Science.gov (United States)

    Schultze, Volkmar; Ijsselsteijn, Rob; Scholtes, Theo; Woetzel, Stefan; Meyer, Hans-Georg

    2012-06-18

    We compare the performance of two methods for the synchronization of the atomic spins in optically pumped magnetometers: intensity modulation of the pump light and the classical M(x) method using B(1) field modulation. Both techniques use the same set-up and measure the resulting features of the light after passing a micro-fabricated Cs cell. The intensity-modulated pumping shows several advantages: better noise-limited magnetic field sensitivity, misalignment between pumping and spin synchronization is excluded, and magnetometer arrays without any cross-talk can be easily set up.

  1. Modulation of signaling through GPCR-cAMP-PKA pathways by PDE4 depends on stimulus intensity: Possible implications for the pathogenesis of acrodysostosis without hormone resistance.

    Science.gov (United States)

    Motte, Emmanuelle; Le Stunff, Catherine; Briet, Claire; Dumaz, Nicolas; Silve, Caroline

    2017-02-15

    In acrodysostosis without hormone resistance, a disease caused by phosphodiesterase (PDE)-4D mutations, increased PDE activity leads to bone developmental defects but with normal renal responses to PTH. To identify potential mechanisms for these disparate responses, we compared the effect of PDE activity on hormone signaling through the GPCR-Gsα-cAMP-PKA pathway in cells from two lineages, HEK-293 cells stably overexpressing PTH1R (HEKpthr) and human dermal fibroblasts, including studies evaluating cAMP levels using an Epac-based BRET-sensor for cAMP (CAMYEL). For ligand-induced responses inducing strong cAMP accumulation, the inhibition of PDE4 activity resulted in relatively small further increases. In contrast, when ligand-induced cAMP accumulation was of lesser intensity, the inhibition of PDE4 had a more pronounced effect. Similar results were obtained evaluating downstream events (cellular CREB phosphorylation and CRE-luciferase activity). Thus, the ability of PDE4 to modulate signaling through GPCR-cAMP-PKA pathways can depend on the cell type and stimulus intensity.

  2. Clinical Characteristics and Prognosis of Peri-strut Low-intensity Area Detected by Optical Coherence Tomography

    Directory of Open Access Journals (Sweden)

    De-Wei Wu

    2015-01-01

    Conclusions: PLIA detected by OCT was positively correlated with higher serum lipid level, history of cerebrovascular disease and initial presentation of ACS, and negatively correlated with stent implantation time. Patients with PLIA were more likely to have UA than those with high-intensity while no significant difference was found in MACEs.

  3. Predicting dropout from intensive outpatient cognitive behavioural therapy for binge eating disorder using pre-treatment characteristics: A naturalistic study

    NARCIS (Netherlands)

    Vroling, M.S.; Wiersma, F.E.; Lammers, M.W.; Noorthoorn, E.O.

    2016-01-01

    Background: Dropout rates in binge eating disorder (BED) treatment are high (17-30%), and predictors of dropout are unknown. Method: Participants were 376 patients following an intensive outpatient cognitive behavioural therapy programme for BED, 82 of whom (21.8%) dropped out of treatment. An explo

  4. Predicting dropout from intensive outpatient cognitive behavioural therapy for binge eating disorder using pre-treatment characteristics: A naturalistic study

    NARCIS (Netherlands)

    Vroling, M.S.; Wiersma, F.E.; Lammers, M.W.; Noorthoorn, E.O.

    2016-01-01

    Background: Dropout rates in binge eating disorder (BED) treatment are high (17-30%), and predictors of dropout are unknown. Method: Participants were 376 patients following an intensive outpatient cognitive behavioural therapy programme for BED, 82 of whom (21.8%) dropped out of treatment. An

  5. Acute High-intensity Interval Exercise-induced Redox Signaling is Associated with Enhanced Insulin Sensitivity in Obese Middle-aged Men.

    Directory of Open Access Journals (Sweden)

    Lewan Parker

    2016-09-01

    Full Text Available Background. Obesity and ageing are associated with increased oxidative stress, activation of stress and mitogen activated protein kinases (SAPK, and the development of insulin resistance and metabolic disease. In contrast, acute exercise also increases oxidative stress and SAPK signaling, yet is reported to enhance insulin sensitivity and reduce the risk of metabolic disease. This study explored this paradox by investigating the effect of a single session of high-intensity interval-exercise (HIIE on redox status, muscle SAPK and insulin protein signaling in eleven middle-aged obese men. Methods. Participants completed a 2 hour hyperinsulinaemic-euglycaemic clamp at rest, and 60 minutes after HIIE (4x4 mins at 95% HRpeak; 2 min recovery periods, separated by 1-3 weeks. Results. Irrespective of exercise-induced changes to redox status, insulin stimulation both at rest and after HIIE similarly increased plasma superoxide dismutase activity, plasma catalase activity, and skeletal muscle 4-HNE; and significantly decreased plasma TBARS and hydrogen peroxide. The SAPK signaling pathways of p38 MAPK, NF-κB p65, and JNK, and the distal insulin signaling protein AS160Ser588, were activated with insulin stimulation at rest and to a greater extent with insulin stimulation after a prior bout of HIIE. Higher insulin sensitivity after HIIE was associated with higher insulin-stimulated SAPK phosphorylation (JNK, p38 MAPK and NF-κB and SOD activity (p<0.05. Conclusion. These findings support a role for redox homeostasis and SAPK signaling in insulin-stimulated glucose uptake which may contribute to the enhancement of insulin sensitivity in obese men 3 hours after HIIE.

  6. Characteristic Signal of Neutron-Antineutron Oscillation in Argon Nuclei at DUNE.

    Science.gov (United States)

    Barrow, Joshua; Kamyshkov, Yuri; Rybolt, Ben; Deep Underground Neutrino Experiment Collaboration

    2017-01-01

    Babu et al. have recently proposed a model of post-sphaleron baryogenesis following the electroweak phase transition. Their theory naturally gives rise to a plausible baryon abundance and a ΔB =2 six-quark operator which allows for the generation of nbar from n. Using n bound in Ar, DUNE currently plans to include n-nbar events in their nucleon decay searches. Using GENIE, modeling is underway on intranuclear interactions mimicking n-nbar annihilation in Ar nuclei. Eliminating atmospheric ν background from such events will be a challenge for liquid Ar TPCs at DUNE, so simulation work must be considered for ν interactions in Ar nuclei, which produce similar signals to n-nbar annihilation. Key to understanding possible experimental signals will be the integration of these two for a proper robust analysis, which will determine the viability of any detection of this process above background levels. Department of Energy-High Energy Physics.

  7. Characteristics of magnetic memory signals for medium carbon steel under static tensile conditions

    Institute of Scientific and Technical Information of China (English)

    YIN Da-wei; XU Bin-shi; DONG Shi-yun; YANG Shang-lin; DONG Li-hong

    2005-01-01

    To test the magnetic signals leaked from the surface of specimens during loading, the experiments of the static tensile of medium carbon 45# steel were carried out. The results show that the magnetic field strength values rapidly vary when the load began, and the curves of the magnetic field strength change from irregularity to regularity with the increase of the load. Furthermore, by comparing with the state of on-line testing, it is found that the magnetic signals of out-of-line testing has more practicability. In the course of loading, though the dots of passing zero of the magnetic field strength continually changed their positions and quantities, the last rupture places were always approached by the dots of passing zero since the elastic loading phase. Some certain relations should exist between external stress and changing of magnetic signals inside the material, and correlative explanation is made based on dislocation theory and the mechanism of magnetic domain action, which provides the basis for further research of magnetic memory.

  8. Fabric circuit board-based dry electrode and its characteristics for long-term physiological signal recording.

    Science.gov (United States)

    Yoo, Jerald; Yoo, Hoi-Jun

    2011-01-01

    This paper presents a dry fabric electrode and its characteristics. For long-term physiological signal monitoring, conventional wet type electrode such as an Ag/AgCl electrode may not be sufficient, because captured signal strength degrades over time as its electrolyte dehydrates. Moreover, the electrolyte may cause skin irritation over a period of time. As a complement, a dry electrode can be used. In this work, fabric-based dry electrodes are introduced. Planar-Fabric Circuit Board (P-FCB) technology enables low cost and uniform productions of such electrodes; electrical properties of the electrodes with various materials, sizes, and time are shown. Both the strengths and drawbacks of the fabric-based electrodes are also discussed.

  9. Signal intensity change on unenhanced T1-weighted images in dentate nucleus following gadobenate dimeglumine in patients with and without previous multiple administrations of gadodiamide

    Energy Technology Data Exchange (ETDEWEB)

    Ramalho, Joana [University of North Carolina Hospital, Chapel Hill, NC (United States); Centro Hospitalar de Lisboa Central, Lisbon (Portugal); Semelka, Richard C.; Castillo, Mauricio [University of North Carolina Hospital, Chapel Hill, NC (United States); AlObaidy, Mamdoh [University of North Carolina Hospital, Chapel Hill, NC (United States); King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Ramalho, Miguel [University of North Carolina Hospital, Chapel Hill, NC (United States); Hospital Garcia de Orta, Almada (Portugal); Nunes, Renato H. [University of North Carolina Hospital, Chapel Hill, NC (United States); Santa Casa de Misericordia de Sao Paulo, Sao Paulo (Brazil)

    2016-11-15

    To evaluate the impact of previous administration of gadodiamide and neural tissue gadolinium deposition in patients who received gadobenate dimeglumine. Our population included 62 patients who underwent at least three administrations of gadobenate dimeglumine, plus an additional contrast-enhanced last MRI for reference, divided into two groups: group 1, patients who in addition to gadobenate dimeglumine administrations had prior exposure to multiple doses of gadodiamide; group 2, patients without previous exposure to other gadolinium-based contrast agent (GBCAs). Quantitative analysis was performed on the first and last gadobenate dimeglumine MRIs in both groups. Dentate nucleus-to-middle cerebellar peduncle signal intensity ratios (DN/MCP) and relative change (RC) in signal over time were calculated and compared between groups using generalized additive model. Group 1 showed significant increase in baseline and follow-up DN/MCP compared to group 2 (p < 0.0001). The RC DN/MCP showed a non-statistically significant trend towards an increase in patients who underwent previous gadodiamide (p = 0.0735). There is increased T1 signal change over time in patients who underwent gadobenate dimeglumine and had received prior gadodiamide compared to those without known exposure to previous gadodiamide. A potentiating effect from prior gadodiamide on subsequent administered gadobenate dimeglumine may occur. (orig.)

  10. Neuro-developmental outcome at 18 months in premature infants with diffuse excessive high signal intensity on MR imaging of the brain

    Energy Technology Data Exchange (ETDEWEB)

    Hart, Anthony [Sheffield Teaching Hospitals NHS Foundation Trust, Department of Neonatology, Sheffield (United Kingdom); University of Sheffield, Department of Academic Radiology, Sheffield, South Yorkshire (United Kingdom); Whitby, Elspeth; Paley, Martyn [University of Sheffield, Department of Academic Radiology, Sheffield, South Yorkshire (United Kingdom); Wilkinson, Stuart; Smith, Michael [Sheffield Teaching Hospitals NHS Foundation Trust, Department of Neonatology, Sheffield (United Kingdom); Alladi, Sathya [Sheffield Teaching Hospitals NHS Foundation Trust, Department of Child Development, Sheffield (United Kingdom)

    2011-10-15

    Diffuse excessive high signal intensity (DEHSI) may represent damage to the white matter in preterm infants, but may be best studied alongside quantitative markers. Limited published data exists on its neuro-developmental implications. The purpose of this study was to assess whether preterm children with DEHSI at term-corrected age have abnormal neuro-developmental outcome. This was a prospective observational study of 67 preterm infants with MRI of the brain around term-equivalent age, including diffusion-weighted imaging (DWI). Images were reported as being normal, overtly abnormal or to show DEHSI. A single observer placed six regions of interest in the periventricular white matter and calculated the apparent diffusion coefficients (ADC). DEHSI was defined as (1) high signal on T2-weighted images alone, (2) high signal with raised ADC values or (3) raised ADC values independent of visual appearances. The neuro-development was assessed around 18 months' corrected age using the Bayley Scales of Infant and Toddler Development (3rd Edition). Standard t tests compared outcome scores between imaging groups. No statistically significant difference in neuro-developmental outcome scores was seen between participants with normal MRI and DEHSI, regardless of which definition was used. Preterm children with DEHSI have similar neuro-developmental outcome to those with normal brain MRI, even if the definition includes objective markers alongside visual appearances. (orig.)

  11. The influence of laser pulse duration and energy on ICP-MS signal intensity, elemental fractionation, and particle size distribution in NIR fs-LA-ICP-MS

    Science.gov (United States)

    Diwakar, Prasoon K.; Harilal, Sivanandan S.; LaHaye, Nicole L.; Hassanein, Ahmed; Kulkarni, Pramod

    2015-01-01

    Laser parameters, typically wavelength, pulse width, irradiance, repetition rate, and pulse energy, are critical parameters which influence the laser ablation process and thereby influence the LA-ICP-MS signal. In recent times, femtosecond laser ablation has gained popularity owing to the reduction in fractionation related issues and improved analytical performance which can provide matrix-independent sampling. The advantage offered by fs-LA is due to shorter pulse duration of the laser as compared to the phonon relaxation time and heat diffusion time. Hence the thermal effects are minimized in fs-LA. Recently, fs-LA-ICP-MS demonstrated improved analytical performance as compared to ns-LA-ICP-MS, but detailed mechanisms and processes are still not clearly understood. Improvement of fs-LA-ICP-MS over ns-LA-ICP-MS elucidates the importance of laser pulse duration and related effects on the ablation process. In this study, we have investigated the influence of laser pulse width (40 fs to 0.3 ns) and energy on LA-ICP-MS signal intensity and repeatability using a brass sample. Experiments were performed in single spot ablation mode as well as rastering ablation mode to monitor the Cu/Zn ratio. The recorded ICP-MS signal was correlated with total particle counts generated during laser ablation as well as particle size distribution. Our results show the importance of pulse width effects in the fs regime that becomes more pronounced when moving from femtosecond to picosecond and nanosecond regimes. PMID:26664120

  12. Detection of fruit by the Cerrado's marmoset (Callithrix penicillata): modeling color signals for different background scenarios and ambient light intensities.

    Science.gov (United States)

    Perini, Eduardo Sosti; Pessoa, Valdir Filgueiras; Pessoa, Daniel Marques de Almeida

    2009-04-01

    Among placental mammals, only primates have trichromatic color vision, however this is not a uniform condition. Under different genetic status, Old World monkeys have routine trichromacy, while New World monkeys show a visual polymorphism, characterized by obligatory male dichromacy. The ecological role of this genetic difference still remains unclear, but some studies show that dichromats and trichromats appear to have different abilities in detecting colored targets against a background of leaves. The Cerrado's marmoset (Callithrix penicillata) is known to forage in brightly illuminated (savanna-like vegetation) and dimly illuminated (forests) environments, exploiting a high amount of dark fruits. Hence, it seems to be a good model for studying the differential advantages enjoyed by each color vision phenotype under natural conditions. Our aim was to verify how the different phenotypes of Cerrado's marmoset detect components of their diet, evaluating the existence of differential phenotype advantages. Under two different light conditions, visual signals of naturally consumed fruits were modeled against different backgrounds scenarios. Even though dichromats and trichromats appear to be equally suited for tasks involving fruit detection, phenotype differential advantages are observed in this marmoset. In many conditions trichromats are predicted to perform better than dichromats, but under low ambient light dichromats manage to outperform trichromats in some scenarios. Phenotypes that carry widely spaced and longer M/L pigments enjoy the most advantage. These differential performances of trichromatic phenotypes, together with overdominance selection, seem to explain the maintenance of the tri-allelic system found in callitrichids.

  13. Characteristics of a GaN-based Gunn diode for THz signal generation

    Science.gov (United States)

    Parida, R. K.; Agrawala, N. C.; Dash, G. N.; Panda, A. K.

    2012-08-01

    A generalized large-signal computer simulation program for a Gunn oscillator has been developed. The properties of a Gunn diode oscillator based on the widely explored GaN, are investigated using the developed program. The results show some interesting properties in GaN Gunn diodes which are not seen in GaAs and InP diodes. An output power of 1400 kW/cm2 is achieved from the GaN Gunn diode, as compared to 4.9 kW/cm2 from a GaAs diode.

  14. Characteristics of a GaN-based Gunn diode for THz signal generation

    Institute of Scientific and Technical Information of China (English)

    R K Parida; N C Agrawala; G N Dash; A K Panda

    2012-01-01

    A generalized large-signal computer simulation program for a Gunn oscillator has been developed.The properties of a Gunn diode oscillator based on the widely explored GaN,are investigated using the developed program.The results show some interesting properties in GaN Gunn diodes which are not seen in GaAs and lnP diodes.An output power of 1400 kW/cm2 is achieved from the GaN Gunn diode,as compared to 4.9 kW/cm2 from a GaAs diode.

  15. Dynamical characteristics of surface EMG signals of hand grasps via recurrence plot.

    Science.gov (United States)

    Ouyang, Gaoxiang; Zhu, Xiangyang; Ju, Zhaojie; Liu, Honghai

    2014-01-01

    Recognizing human hand grasp movements through surface electromyogram (sEMG) is a challenging task. In this paper, we investigated nonlinear measures based on recurrence plot, as a tool to evaluate the hidden dynamical characteristics of sEMG during four different hand movements. A series of experimental tests in this study show that the dynamical characteristics of sEMG data with recurrence quantification analysis (RQA) can distinguish different hand grasp movements. Meanwhile, adaptive neuro-fuzzy inference system (ANFIS) is applied to evaluate the performance of the aforementioned measures to identify the grasp movements. The experimental results show that the recognition rate (99.1%) based on the combination of linear and nonlinear measures is much higher than those with only linear measures (93.4%) or nonlinear measures (88.1%). These results suggest that the RQA measures might be a potential tool to reveal the sEMG hidden characteristics of hand grasp movements and an effective supplement for the traditional linear grasp recognition methods.

  16. Concordant preferences for opposite-sex signals? Human pheromones and facial characteristics.

    Science.gov (United States)

    Cornwell, R Elisabeth; Boothroyd, Lynda; Burt, D Michael; Feinberg, David R; Jones, Ben C; Little, Anthony C; Pitman, Robert; Whiten, Susie; Perrett, David I

    2004-03-22

    We have investigated whether preferences for masculine and feminine characteristics are correlated across two modalities, olfaction and vision. In study 1, subjects rated the pleasantness of putative male (4,16-androstadien-3-one; 5alpha-androst-16-en-3-one) and female (1,3,5 (10),16-estratetraen-3-ol) pheromones, and chose the most attractive face shape from a masculine-feminine continuum for a long- and a short-term relationship. Study 2 replicated study 1 and further explored the effects of relationship context on pheromone ratings. For long-term relationships, women's preferences for masculine face shapes correlated with ratings of 4,16-androstadien-3-one and men's preferences for feminine face shapes correlated with ratings of 1,3,5(10),16-estratetraen-3-ol. These studies link sex-specific preferences for putative human sex pheromones and sexually dimorphic facial characteristics. Our findings suggest that putative sex pheromones and sexually dimorphic facial characteristics convey common information about the quality of potential mates.

  17. Characteristics of traffic flow at a non-signalized intersection in the framework of game theory

    Science.gov (United States)

    Fan, Hongqiang; Jia, Bin; Tian, Junfang; Yun, Lifen

    2014-12-01

    At a non-signalized intersection, some vehicles violate the traffic rules to pass the intersection as soon as possible. These behaviors may cause many traffic conflicts even traffic accidents. In this paper, a simulation model is proposed to research the effects of these behaviors at a non-signalized intersection. Vehicle’s movement is simulated by the cellular automaton (CA) model. The game theory is introduced for simulating the intersection dynamics. Two types of driver participate the game process: cooperator (C) and defector (D). The cooperator obey the traffic rules, but the defector does not. A transition process may occur when the cooperator is waiting before the intersection. The critical value of waiting time follows the Weibull distribution. One transition regime is found in the phase diagram. The simulation results illustrate the applicability of the proposed model and reveal a number of interesting insights into the intersection management, including that the existence of defectors is benefit for the capacity of intersection, but also reduce the safety of intersection.

  18. 不同平均强度热盐环流的年代际波动特征%Interdecadal characteristics of thermohaline circulation with different mean intensities

    Institute of Scientific and Technical Information of China (English)

    张福颖; 郭品文; 程军; 倪东鸿

    2013-01-01

    The CCSM3(community climate system model version 3) model developed by the National Center for Atmospheric Research was used to study the interdecadal characteristics of thermohaline circulation (THC) in the freshwater disturbance experiments with different mean THC intensities, and the influences on North Atlantic climate. Results show that THC interdecadal fluctuation characteristics have significant differences in the experiments with different THC intensities. The impact of THC changes on more than 100 years scale on its interdecadal fluctuations is significant. In high average intensity, THC interdecadal fluctuation is longer and more significant. The interannual responses of SST(sea surface temperature) and SLP(sea lever pressure) to different THC intensities in North Atlantic are obviously different. In the high average intensity, the dominant correlation mode between North Atlantic SST and THC index exhibits a meridional tripole pattern, and the dominant correlation mode between North Atlantic SLP and THC index does a NAO(North Atlantic Oscillation)-like pattern, but the two modes do not exit in the low average intensity. In high average intensity,the correlation between THC and the various elements is more significant.%基于美国国家大气研究中心的CCSM3 (community climate system model version 3)模式,对淡水扰动试验下不同平均强度热盐环流(thermohline circulation,THC)的年代际波动特征及北大西洋气候响应特征进行研究.结果表明,百年以上尺度的THC变化对其年代际尺度波动产生显著影响,高平均强度下THC的年代际波动周期更长、更显著.对不同平均强度下北大西洋海、气要素与THC在年代际尺度上的相关分布进行分析,发现在高平均强度下,THC与海表温度(sea surface temperature,SST)的相关呈现为经向三核型分布,与海平面气压(sea lever pressure,SLP)的相关呈现为类NAO(North Atlantic oscillation)分布,而在低

  19. Damaging biting behaviors in intensively kept rearing gilts: the effect of jute sacks, and relations with production characteristics

    NARCIS (Netherlands)

    Ursinus, W.W.; Wijnen, H.J.; Bartels, A.C.; Duijvesteijn, N.; Reenen, van C.G.; Bolhuis, J.E.

    2014-01-01

    Pigs may display biting behavior directed at pen mates, resulting in body damage such as tail wounds. We assessed the suitability of jute sacks (hung vertically at wall) to reduce biting behaviors and tail wounds in rearing gilts. Additionally, we assessed several characteristics of different types

  20. Damaging biting behaviors in intensively kept rearing gilts: the effect of jute sacks, and relations with production characteristics

    NARCIS (Netherlands)

    Ursinus, W.W.; Wijnen, H.J.; Bartels, A.C.; Duijvesteijn, N.; Reenen, van C.G.; Bolhuis, J.E.

    2014-01-01

    Pigs may display biting behavior directed at pen mates, resulting in body damage such as tail wounds. We assessed the suitability of jute sacks (hung vertically at wall) to reduce biting behaviors and tail wounds in rearing gilts. Additionally, we assessed several characteristics of different types

  1. Deep white matter hyperintensity in the occipital lobe on T sub 2 -weighted MRI in children, 2; Classification based on the signal intensity

    Energy Technology Data Exchange (ETDEWEB)

    Miyazaki, Masahito; Hashimoto, Toshiaki (Tokushima Univ. (Japan). School of Medicine)

    1992-01-01

    Twenty-seven children, who had deep white matter hyperintensity in the occipital lobe (DWMH) on T{sub 2}-weighted MRI, were classified into two groups, mild and severe, based on the signal intensity. The frequency of mild DWMH, which was iso- or hyperintense relative to the gray matter but hypointense relative to cerebrospinal fluid (CSF), decreased with aging; mild DWMH might result from a delayed myelination in the central nervous system. However, the frequency of severe DWMH, which was iso- or hyperintense relative to CSF, was not related to aging and was significantly high in severely retarded children. Therefore, severe DWMH might be a new indicator of mental retardation in children. (author).

  2. Signal intensity of normal breast tissue at MR mammography on midfield: applying a random coefficient model evaluating the effect of doubling the contrast dose

    DEFF Research Database (Denmark)

    Marklund, Mette; Christensen, Robin; Torp-Pedersen, Søren

    2007-01-01

    PURPOSE: To prospectively investigate the effect on signal intensity (SI) of healthy breast parenchyma on magnetic resonance mammography (MRM) when doubling the contrast dose from 0.1 to 0.2 mmol/kg bodyweight. MATERIALS AND METHODS: Informed consent and institutional review board approval were...... and an axial dynamic T1W FFED, with a total of seven frames. At day 1, an i.v. gadolinium (Gd) bolus injection of 0.1 mmol/kg bodyweight (Omniscan) (low) was administered. On day 2, the contrast dose was increased to 0.2 mmol/kg (high). Injection rate was 2 mL/s (day 1) and 4 mL/s (day 2). Any use of estrogen...

  3. Current characteristic signals of aqueous solution transferring through microfluidic channel under non-continuous DC electric field

    Directory of Open Access Journals (Sweden)

    HongWei Ma

    2014-10-01

    Full Text Available The surface effect is becoming apparently significant as the miniaturization of fluidic devices. In the micro/nanochannel fluidics, the electrode surface effects have the same important influence on the current signals as the channel surface effects. In this paper, when aqueous solution are driven with non-continuous DC electric field force, the characteristics of current signals of the fluid transferring through microfluidic channel are systematically studied. Six modes of current signal are summarized, and some new significant phenomena are found, e.g. there exists a critical voltage at which the steady current value equals to zero; the absolute value of the steady current decreases at first, however, it increases with the external voltage greater than the critical voltage as the electrode area ratio of cathode and anode is 10 and 20; the critical voltage increases with the enhancing of electrode area ratio of cathode and anode and solution pH, while it decreases with the raising of ion concentration. Finally, the microscopic mechanism of the electrode surface charge effects is discussed preliminarily. The rules will be helpful for detecting and manipulating single biomolecules in the micro/nanofluidic chips and biosensors.

  4. Combination of signal intensity measurements of lesions in the peripheral zone of prostate with MRI and serum PSA level for differentiating benign disease from prostate cancer

    Energy Technology Data Exchange (ETDEWEB)

    Engelhard, K.; Kreckel, M. [Department of Radiology, Martha-Maria Hospital Nuernberg (Germany); Hollenbach, H.P.; Deimling, M. [Siemens Medical Engineering Group, Erlangen (Germany); Riedl, C. [Dept. of Urology, University of Erlangen-Nuernberg, Erlangen (Germany)

    2000-12-01

    The aim of this study was to predict the benign or malignant nature of a prostatic lesion by defining a threshold value of signal intensity ratio and a limiting value of serum prostate-specific antigen (PSA) in patients with elevated PSA level. Twenty-six patients with elevated PSA level and no hypoechogenic lesions at endosonography underwent MR imaging using an endorectal body phased-array coil at 1.5 T (Siemens Magnetom Symphony). A T2-weighted turbo-spin-echo (TSE) pulse sequence was applied in a transverse orientation. Two radiologists evaluated the images. In the presence of a pathological finding they defined regions of interest (ROI) in the suspicious pathological area of the peripheral zone and in muscle for reference. The quotient of the two ROIs was calculated and then correlated with the actual PSA level. Diagnosis was confirmed by prostate biopsy. Ten of 12 patients with quotients smaller than 4 showed cancer at histology. Nine of 12 men with cancer proven by biopsy had PSA levels higher than 10 ng/ml. A significant difference (p < 0.001) was found between the quotients of cancer and quotients of chronic prostatitis, fibrosis, or glandular atrophy. The accuracy of tumor differentiation of the method was 77 %. Measurement of signal intensity quotients in the peripheral zone of the prostate in combination with knowledge of defined limits of PSA levels the technique could be helpful in detecting additional cancer areas for prostate biopsy. False-negative tumor results of standard sextant biopsy can be reduced. In men with high PSA values the method has a role in differentiating between patients who require prostate biopsy and those of clinical observation. (orig.)

  5. Usefulness of perfusion weighted magnetic resonance imaging with signal-intensity curves analysis in the differential diagnosis of sellar and parasellar tumors: Preliminary report

    Energy Technology Data Exchange (ETDEWEB)

    Bladowska, Joanna, E-mail: asia.bladowska@gmail.com [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Zimny, Anna, E-mail: abernac@wp.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Guziński, Maciej, E-mail: guziol@wp.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Hałoń, Agnieszka, E-mail: ahalon2@gmail.com [Department of Pathomorphology and Oncological Cytology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Tabakow, Paweł, E-mail: p.tabakov@wp.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Czyż, Marcin, E-mail: mt.czyz@gmail.com [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Czapiga, Bogdan, E-mail: bogdanczapiga@op.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Jarmundowicz, Włodzimierz, E-mail: jarmund@wp.pl [Department of Neurosurgery, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland); Sąsiadek, Marek J., E-mail: marek.sasiadek@am.wroc.pl [Department of General Radiology, Interventional Radiology and Neuroradiology, Wroclaw Medical University, Borowska 213, 50-556 Wroclaw (Poland)

    2013-08-15

    Purpose: The most common pituitary tumors are adenomas, which however may be mimicked by other tumors that can show a very similar appearance in plain MRI. The aim of our study was to evaluate the usefulness of perfusion weighted MR imaging (PWI), including signal-intensity curves analysis in the differential diagnosis of sellar/parasellar tumors. Methods: Forty-one patients with sellar/parasellar tumors (23 macroadenomas, 10 meningiomas, 5 craniopharyngiomas, 1 intrasellar hemangioblastoma, 1 intrasellar prostate cancer metastasis, 1 suprasellar glioma), underwent plain MRI followed by PWI using a 1.5T unit. In each tumor, the mean and maximum values of relative cerebral blood volume (rCBV), as well as the relative peak height (rPH) and the relative percentage of signal intensity recovery (rPSR) were calculated. Results: The high perfusion tumors were: macroadenomas, meningiomas, squamous-papillary type of craniopharyngiomas, hemangioblastoma, glioma and metastasis. The low perfusion neoplasms included adamantinomatous type of craniopharyngiomas. By comparing adenomas and meningiomas, we found statistically significant differences in the mean and maximum rCBV values (p = 0.026 and p = 0.019, respectively), but not in rPH and rPSR. The maximum rCBV values >7.14 and the mean rCBV values >5.74 with the typical perfusion curve were very suggestive of the diagnosis of meningioma. There were differences between adenomas and other high perfusion tumors in rPH and rPSR values. Conclusions: PWI can provide additional information helpful in differential diagnosis of sellar/parasellar tumors. In our opinion PWI, as an easy to perform and fast technique should be incorporated into the MR protocol of all intracranial neoplasms including sellar/parasellar tumors.

  6. Concurrent exercise incorporating high-intensity interval or continuous training modulates mTORC1 signaling and microRNA expression in human skeletal muscle.

    Science.gov (United States)

    Fyfe, Jackson J; Bishop, David J; Zacharewicz, Evelyn; Russell, Aaron P; Stepto, Nigel K

    2016-06-01

    We compared the effects of concurrent exercise, incorporating either high-intensity interval training (HIT) or moderate-intensity continuous training (MICT), on mechanistic target of rapamycin complex 1 (mTORC1) signaling and microRNA expression in skeletal muscle, relative to resistance exercise (RE) alone. Eight males (mean ± SD: age, 27 ± 4 yr; V̇o2 peak , 45.7 ± 9 ml·kg(-1)·min(-1)) performed three experimental trials in a randomized order: 1) RE (8 × 5 leg press repetitions at 80% 1-repetition maximum) performed alone and RE preceded by either 2) HIT cycling [10 × 2 min at 120% lactate threshold (LT); HIT + RE] or 3) work-matched MICT cycling (30 min at 80% LT; MICT + RE). Vastus lateralis muscle biopsies were obtained immediately before RE, either without (REST) or with (POST) preceding endurance exercise and +1 h (RE + 1 h) and +3 h (RE + 3 h) after RE. Prior HIT and MICT similarly reduced muscle glycogen content and increased ACC(Ser79) and p70S6K(Thr389) phosphorylation before subsequent RE (i.e., at POST). Compared with MICT, HIT induced greater mTOR(Ser2448) and rps6(Ser235/236) phosphorylation at POST. RE-induced increases in p70S6K and rps6 phosphorylation were not influenced by prior HIT or MICT; however, mTOR phosphorylation was reduced at RE + 1 h for MICT + RE vs. both HIT + RE and RE. Expression of miR-133a, miR-378, and miR-486 was reduced at RE + 1 h for HIT + RE vs. both MICT + RE and RE. Postexercise mTORC1 signaling following RE is therefore not compromised by prior HIT or MICT, and concurrent exercise incorporating HIT, but not MICT, reduces postexercise expression of miRNAs implicated in skeletal muscle adaptation to RE.

  7. Drought evolution characteristics and precipitation intensity changes during alternating dry–wet changes in the Huang–Huai–Hai River basin

    Directory of Open Access Journals (Sweden)

    D. H. Yan

    2013-07-01

    precipitation intensities with the increase in drought level is relatively complex. (3 As the drought times increase, areas I, II and V, which are located on the coastal and in the valley or basin, are vulnerable to extreme precipitation processes; areas III, IV, VI and VII are located in the inland area, where heavier precipitation is not likely to occur. (4 The local rainfall affected by multiple factors is closely related with drought occurrence. The characteristics between the first rainfall intensity after a drought period and different drought magnitudes (or drought occurrence times are preliminarily examined in this paper, but its formation mechanism still requires further research.

  8. Theoretical investigations of quantum-dot semiconductor optical amplifier enabled intensity modulation of adaptively modulated optical OFDM signals in IMDD PON systems.

    Science.gov (United States)

    Hamié, A; Hamze, M; Wei, J L; Sharaiha, A; Tang, J M

    2011-12-05

    Extensive explorations are undertaken, for the first time, of the feasibility of utilizing quantum-dot semiconductor optical amplifier intensity modulators (QD-SOA-IMs) in cost-sensitive intensity-modulation and direct-detection (IMDD) passive optical network (PON) systems based on adaptively modulated optical orthogonal frequency division multiplexing (AMOOFDM). A theoretical QD-SOA-IM model is developed, based on which optimum QD-SOA-IM operating conditions are identified together with major physical mechanism considerably affecting the system performance. It is shown that, in comparison with previously reported SOA-IMs in similar transmission systems, QD-SOA-IMs cannot only considerably improve the AMOOFDM transmission performance but also broaden the dynamic range of optimum operating conditions. In particular, for achieving signal bit rates of >30Gb/s over >60km single mode fiber (SMF), QD-SOA-IMs offer a 10dB reduction in CW optical input powers injected into the modulators. In addition, QD-SOA-IMs can also be employed to compensate the chromatic dispersion effect.

  9. Analyzing the characteristics of phase-shift keyed signals applied to the measurement of an electron concentration profile using the radiophysical model of the ionosphere

    Science.gov (United States)

    Alsatkin, S. S.; Medvedev, A. V.; Kushnarev, D. S.

    2009-12-01

    The radiophysical model of the ionosphere, which can approximately imitate the ionospheric response to a sounding signal, is presented. The model mathematical description and input parameters are given. The results of modeling the ionospheric response to different types of sounding signals are presented. The methods for estimating the quality of restoration of an initial power profile are described. The optimal characteristics of the signal, which allows for a high-quality restoration of an initial power profile, and the modeling results are presented.

  10. Music preferences with hearing aids: effects of signal properties, compression settings, and listener characteristics.

    Science.gov (United States)

    Croghan, Naomi B H; Arehart, Kathryn H; Kates, James M

    2014-01-01

    Current knowledge of how to design and fit hearing aids to optimize music listening is limited. Many hearing-aid users listen to recorded music, which often undergoes compression limiting (CL) in the music industry. Therefore, hearing-aid users may experience twofold effects of compression when listening to recorded music: music-industry CL and hearing-aid wide dynamic-range compression (WDRC). The goal of this study was to examine the roles of input-signal properties, hearing-aid processing, and individual variability in the perception of recorded music, with a focus on the effects of dynamic-range compression. A group of 18 experienced hearing-aid users made paired-comparison preference judgments for classical and rock music samples using simulated hearing aids. Music samples were either unprocessed before hearing-aid input or had different levels of music-industry CL. Hearing-aid conditions included linear gain and individually fitted WDRC. Combinations of four WDRC parameters were included: fast release time (50 msec), slow release time (1,000 msec), three channels, and 18 channels. Listeners also completed several psychophysical tasks. Acoustic analyses showed that CL and WDRC reduced temporal envelope contrasts, changed amplitude distributions across the acoustic spectrum, and smoothed the peaks of the modulation spectrum. Listener judgments revealed that fast WDRC was least preferred for both genres of music. For classical music, linear processing and slow WDRC were equally preferred, and the main effect of number of channels was not significant. For rock music, linear processing was preferred over slow WDRC, and three channels were preferred to 18 channels. Heavy CL was least preferred for classical music, but the amount of CL did not change the patterns of WDRC preferences for either genre. Auditory filter bandwidth as estimated from psychophysical tuning curves was associated with variability in listeners' preferences for classical music. Fast

  11. Limnological characteristics of a reservoir in semiarid Northeastern Brazil subject to intensive tilapia farming (Orechromis niloticus Linnaeus, 1758

    Directory of Open Access Journals (Sweden)

    Luis Artur Valões Bezerra

    2014-03-01

    Full Text Available AIM: There is currently no consensus regarding the physical and chemical variability of tropical reservoirs. In semiarid Northeastern Brazil, reservoirs are among other things used for human consumption, industrial water supply and intensive fish farming, all of which can impact water quality. The objective of this study was to evaluate the physical and chemical variability of the water in Sítios Novos, a reservoir in semiarid Northeastern Brazil, comparing samples collected in areas of intensive tilapia (Oreochromis niloticus farming to samples from areas not directly impacted by aquaculture, in both the dry and the rainy season. METHODS: Between October 2010 and July 2011, data were collected on temperature, conductivity, pH, turbidity, salinity, chlorophyll a, dissolved oxygen, oxygen demand, total phosphorus and total nitrogen levels in the water column using a multiparametric probe at four different sampling locations. Physical and chemical differences between the four locations were evaluated with the Kruskal-Wallis (KW test and Dunn's post test, while the t test, followed by Welchʼs correction, was used to compare samples collected in different seasons. RESULTS: No influence of intensive aquaculture was detected when comparing sampling locations near fish farms (180C and 300C to locations not directly impacted by aquaculture (LIMN1, near the dam, and LIMN2, near the debouch of the São Gonçalo river. However, the sampling locations differed significantly (p<0.05 with regard to conductivity, pH, turbidity and chlorophyll a levels. CONCLUSIONS: The physical and chemical variability was greater between seasons than between locations when the data were analyzed with the t test. That analysis showed significant differences for 22 of 40 comparisons between the 10 physical and chemical parameters in the two seasons at the four sampling locations. In conclusion, the physical and chemical variability registered for the Sítios Novos reservoir

  12. Increased signal intensity at the proximal patellar tendon: correlation between MR imaging and histology in eight cadavers and clinical MR imaging studies

    Energy Technology Data Exchange (ETDEWEB)

    Yun, Seong Jong; Jin, Wook; Yoon, So Hee; Park, So Young [Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Department of Radiology, Seoul (Korea, Republic of); Park, Yong-Koo [Kyung Hee University Medical Center, Department of Pathology, Seoul (Korea, Republic of); Kim, Gou Young [Kyung Hee University Hospital at Gangdong, Kyung Hee University School of Medicine, Department of Pathology, Seoul (Korea, Republic of); Lee, Jung Eun; Park, Ji Seon; Ryu, Kyung Nam [Kyung Hee University Medical Center, Department of Radiology, Seoul (Korea, Republic of)

    2015-10-15

    We set out to investigate the cause of persistently increased signal intensity (SI) in the posterior portion of the proximal patellar tendon (pPT) on T1-weighted images (T1WI). MR imaging was performed in eight cadavers, followed by gross histological examination. In addition, 84 patients without trauma history or anterior knee pain were included to compare the SI of the PTs. The patients were divided according to their age, sex, and Kellgren-Lawrence (KL) grades. The length and thickness of the increased SI portion in the pPT and whole PT (wPT) on T1WI were recorded. Histological specimens demonstrated that the adipose tissue, vessels, and perivascular connective tissue invaginated into the posterior portion of the pPT. This histological anatomy corresponded to the pPT signal change on MR imaging. There was linear and interdigitating increased SI of the pPT in all of the 84 patients (100 %). There were no differences in the lengths and thicknesses of the increased SI portion of pPTs and wPTs according to age, sex, and KL grade (all p > 0.05). The increased SI of the pPT on T1WI and fluid-sensitive MR images results from invaginating fat, vessels, and perivascular connective tissue. It is not pathological, but a normal and common finding. (orig.)

  13. Relationship between the characteristics of the interplanetary medium and the intensity variations of charged particles from the flare of September 7, 1973

    Energy Technology Data Exchange (ETDEWEB)

    Kazarian, M.S.; Kuzhevskii, B.M.; Maduev, V.L.; Mineev, Iu.V.; Spirkova, E.S.; Shestopalov, I.P.

    The propagation characteristics of charged particles generated by a solar flare are studied on the basis of Mars-7 and Prognoz-3 data obtained at different distances from the sun. It is shown that the nature of electron intensity variations at electron energies above 40 keV and proton energies of 0.2 to 20 MeV is determined by changes in the structure of the interplanetary medium, i.e., changes in solar wind velocity and interplanetary magnetic field parameters.

  14. The inter-comparison of major satellite aerosol retrieval algorithms using simulated intensity and polarization characteristics of reflected light

    Directory of Open Access Journals (Sweden)

    A. A. Kokhanovsky

    2010-07-01

    Full Text Available Remote sensing of aerosol from space is a challenging and typically underdetermined retrieval task, requiring many assumptions to be made with respect to the aerosol and surface models. Therefore, the quality of a priori information plays a central role in any retrieval process (apart from the cloud screening procedure and the forward radiative transfer model, which to be most accurate should include the treatment of light polarization and molecular-aerosol coupling. In this paper the performance of various algorithms with respect to the of spectral aerosol optical thickness determination from optical spaceborne measurements is studied. The algorithms are based on various types of measurements (spectral, angular, polarization, or some combination of these. It is confirmed that multiangular spectropolarimetric measurements provide more powerful constraints compared to spectral intensity measurements alone, particularly those acquired at a single view angle and which rely on a priori assumptions regarding the particle phase function in the retrieval process.

  15. A Study on the Characteristics of Microseismic Signal during Deformation and Failure of Different Materials under Uniaxial Compression

    Directory of Open Access Journals (Sweden)

    Chengwu Li

    2016-01-01

    Full Text Available With the decline of shallow coal reserves and increase in demand of coal consumption, the hazard of coal and rock dynamic disasters is expanding. In this paper, we conducted some laboratory scale tests on coal, cement, and glass materials to figure out the microseismic (MS characteristic differences among materials. A new method, denoted as WPT-LMD, is proposed to conduct signal denoising and analysis work. A series of basic analyses regarding MS are conducted, including the relationships between MS characteristics and loading rate, coal powder particle size, loading stage, and MS event statistics. Research results show that the damage of all these three materials is accompanied with MS events, abundant with low frequency component (0–200 Hz. But cement and coal specimens produce with relative wide frequency distribution in sample frequency domain, while glass specimens were found to only produce low frequency event. The powder particle sizes have obvious influence on the strength of coal specimen, but the loading rate seems to have no influence on the MS characteristics. The outcome of the paper will further provide a theoretical basis for understanding the mechanism of MS activities and has great significance to improve the coal mining safety.

  16. Response of Somatal Characteristics and its Plasticity to Different Light Intensities in Leaves of Seven Tropical Woody Seedlings

    Institute of Scientific and Technical Information of China (English)

    CAIZhiquan; QIXing; CAOKunfang

    2004-01-01

    Stomatal characteristics and its plasticity were surveyed in leaves of four canopy species, Shorea chinensis, Pometia tomentosa, Anthocephalus chinensis, Calophyllun polyanthum and three middle-layer species, Barringtonia pendula, Garcinia hanburyi, Horsfieldia tetratepala, acclimated to different light conditions for more than one year. All plant's stomata are distributed on the abaxial of leaves. Pometia tomentosa and Barringtonia pendula have higher stomatal density and the guard cell length of Anthocephalus chinensis and Calophyllun polyanthum were much greater than others'. Stomatal density and stomatal index (ratio of stomatal numbers to epidermal cell number) were increased with growth irradiance increased, while numbers of stomata per leaf were higher in the low than the high relative PFD, and stomatal conductance of leaves was the highest in the 50% of full light except for Anthocephalus chinensis. The relative PFD has little effects on the guard cell length of all seven plants. We have also found a significant negative correlation between stomatal density and leaf area, but the stomatal conductance was not significantly positive with the stomatal conductance. The analysis of phenotypic plasticity of stomatal characteristics showed: plasticity index for stomatal index and numbers of stomatal per leaf were similar for canopy and middle-layer species,while the plasticity index of stomatal density and stomatal conductance were significantly greater for canopy species than middle-layer species. The high plasticity of canopy species was consistent with the hypothesis that specialization in a more favorable environment increases plasticity.

  17. Characteristics of water vapor fluctuations by the use of GNSS signal delays

    Science.gov (United States)

    Gregorič, Asta; Škrlec, Samo; Mole, Maruška; Bergant, Klemen; Vučković, Marko; Stanič, Samo

    2017-04-01

    Water vapor plays a crucial role in a number of atmospheric processes related to the water cycle. It is also the Earth's most abundant greenhouse gas, thus influencing global climate as well as micrometeorology. Since the phase change of water is associated with large latent heat, water vapor plays an important role in the vertical atmospheric stability. It also influences aerosol aging and removal from the atmosphere. As the temporal and spatial distribution of water vapor is in general highly variable, continuous monitoring at several locations is required to be able to describe the situation in a given terrain configuration. In-situ meteorological measurements provide the information on water vapor concentration at the surface only, while the radiosonde data suffers from poor temporal and spatial (horizontal) resolution. Integrated water vapor content above a certain location on the surface can also be monitored in real time, exploiting the wet delay of GNSS signals, however, it does not yield absolute humidity. In this contribution we present a measurement of average absolute humidity within the Vipava valley (Slovenia), between February 2015 and October 2016. It is based on differential measurement of integrated water vapor content at two adjacent stations, using stationary GNSS receivers, which are horizontally displaced for 6 km, and vertically displaced for 826 m. The integrated water vapor values were derived using the GIPSY-OASIS II software. One of the receivers is located at the valley floor (125 m a.s.l.) and the other on the top of the adjacent mountain ridge (951 m a.s.l.). Visual data from both stations was also stored to evaluate the reliability of the remote sensing results in different weather conditions. Based on the dataset covering 20 consecutive months, we investigated temporal evolution of the water vapor content within the valley. The results show typical seasonal pattern and are strongly correlated to weather phenomena. Comparison to the

  18. Imaging Mars: Seeking Characteristic Signals in Models of the Martian Interior

    Science.gov (United States)

    Irving, J. C. E.; Wicks, J. K.

    2015-12-01

    We expect that the interiors of terrestrial planets look somewhat like our own - with a crust, a mantle hosting a range of mineralogical transformations and an iron alloy core. Data from existing geophysical observations of Mars, including its moment of inertia and mass, together with mineralogical, cosmochemical, geodynamical and meteorite information and modeling have lead to the creation of a variety of models of the density profile of the martian interior. A number of these density models are accompanied by seismic profiles in the planet. The presence of liquid layer in the outer core is supported by geodetic information; the presence of a solid inner core has not been conclusively ruled out by previous studies though it is unlikely. Some models predict jumps in seismic velocity in the mantle as steadily increasing pressure changes the stable phase assemblage, while other models instead show smooth increases in velocity. Attenuation in the martian mantle has been estimated by considering the tidal dissipation observed as Phobos orbits Mars. We investigate a range of models of Mars' density and velocity structure, using both simulations of Mars' normal mode oscillations and calculations of body wave travel times, ray paths and synthetic waveforms. For several features of the martian interior, from the presence of sharp boundaries in the mantle, to probable core sizes, we seek seismically observable signatures. Probing Mars' interior using seismic techniques is a key aim of the upcoming InSight mission to Mars; if seismic sources are sufficiently numerous and energetic then the presence of known seismic signatures for characteristics of the martian interior will help us to understand what lies beneath the surface of Mars.

  19. Turbulent characteristics in the intensity fluctuations of a solar quiescent prominence observed by the \\textit{Hinode} Solar Optical Telescope

    CERN Document Server

    Leonardis, Ersilia; Foullon, Claire

    2011-01-01

    We focus on Hinode Solar Optical Telescope (SOT) calcium II H-line observations of a solar quiescent prominence (QP) that exhibits highly variable dynamics suggestive of turbulence. These images capture a sufficient range of scales spatially ($\\sim$0.1-100 arc seconds) and temporally ($\\sim$16.8 s - 4.5 hrs) to allow the application of statistical methods used to quantify finite range fluid turbulence. We present the first such application of these techniques to the spatial intensity field of a long lived solar prominence. Fully evolved inertial range turbulence in an infinite medium exhibits multifractal \\emph{scale invariance} in the statistics of its fluctuations, seen as power law power spectra and as scaling of the higher order moments (structure functions) of fluctuations which have non-Gaussian statistics; fluctuations $\\delta I(r,L)=I(r+L)-I(r)$ on length scale $L$ along a given direction in observed spatial field $I$ have moments that scale as $\\sim L^{\\zeta(p)}$. For turbulence in a system that is o...

  20. Nosocomial infection characteristics in a burn intensive care unit: analysis of an eleven-year active surveillance.

    Science.gov (United States)

    Öncül, Oral; Öksüz, Sinan; Acar, Ali; Ülkür, Ersin; Turhan, Vedat; Uygur, Fatih; Ulçay, Asım; Erdem, Hakan; Özyurt, Mustafa; Görenek, Levent

    2014-08-01

    The objective of this study was to describe nosocomial infection (NI) rates, risk factors, etiologic agents, antibiotic susceptibility, invasive device utilization and invasive device associated infection rates in a burn intensive care unit (ICU) in Turkey. Prospective surveillance of nosocomial infections was performed according to Centers for Disease Control and Prevention (CDC) and National Healthcare Safety Network (NHSN) criteria between 2001 and 2012. The data was analyzed retrospectively. During the study period 658 burn patients were admitted to our burn ICU. 469 cases acquired 602 NI for an overall NI rate of 23.1 per 1000 patient days. 109 of all the cases (16.5%) died. Pseudomonas aeruginosa (241), Acinetobacter baumannii (186) and Staphylococcus aureus (69) were the most common identified bacteria in 547 strains. Total burn surface area, full thickness burn, older age, presence of inhalation injury were determined to be the significant risk factors for acquisition of NI. Determining the NI profile at a certain burn ICU can lead the medical staff apply the appropriate treatment regimen and limit the drug resistance. Eleven years surveillance report presented here provides a recent data about the risk factors of NI in a Turkish burn ICU. Copyright © 2013 Elsevier Ltd and ISBI. All rights reserved.

  1. Characteristics of a miniature parallel-plate free-air ionization chamber for measuring the intensity of synchrotron radiation from an undulator

    Science.gov (United States)

    Nariyama, Nobuteru

    2004-09-01

    In order to develop an absolute intensity monitor for synchrotron radiation from an undulator, the characteristics of a parallel-plate free-air ionization chamber with a plate separation of 4.2 mm, which was considered to be as narrow as possible, were investigated using 8-30 keV monoenergetic photons at SPring-8. Using a Si-PIN photodiode as the reference monitor, saturation was confirmed at 8-30 keV at a photon intensity of an order of 1013 photons/s. The collection efficiency became almost unity at 8 and 10 keV within 3.8% and 1.1%, respectively, which gradually decreased with increasing energy and attained 0.52 at 30 keV because some of the high-energy electrons escaped from the sensitive volume. When the pair of electrodes was transferred from the upper and lower sides to the left and right sides of the beam axis in order to investigate the influence of linear polarization of synchrotron radiation, a decrease in the collection efficiency was observed. Monte Carlo simulations considering linear polarization showed that the plate separation required for no electron loss was 26, 14, and 8 mm for 30, 20, and 15 keV photons, respectively. For 20 keV photons, saturation characteristics were investigated using an ionization chamber with 14 mm plate separation.

  2. Hydro biological Characteristics of Some Semi-intensive fish culture ponds of Lumding town of Nagaon district, Assam

    Directory of Open Access Journals (Sweden)

    Tapashi Gupta

    2013-04-01

    Full Text Available Hydrobiological assessment is useful for assessing the ecological quality of aquatic ecosystem since biological communities integrate the environmental effects of water chemistry. Ten fish ponds from Lumding town, which were under semi-intensive culture practice, were selected for hydrobiological investigations. Physico-chemical properties were studied for a period of two years from July 2009 to June 2011.Some selected parameters like pH, dissolve oxygen, free carbon dioxide, TDS , total alkalinity, total hardness, sp. Conductivity, transparency and BOD were studied on some fish pond water. P H ranges from 6.1 to8.5. Temperature ranges from 18 0 C-32 0 C. Color shows light green to dirty green. Transparency ranges 17-42cm, dissolve oxygen ranges from 3.2-8.0 ppm, total alkalinity ranges from 7.9-20.0ppm, Hardness ranges from 60-135 ppm, sp.conductance ranges from123-247µmhos/cm and BOD ranges from3.1-5.0ppm. The phytoplankton belonging to division Chlorophycae and Cyanophycae are predominant over the others and zooplanktons belonging to group Protozoa, Rotifers are predominant. . A total of 30 species of belonging to Chlorophycae. Cyanophycae were identified and a total of 20 species of Rotifera, 2 species of Cladocera and 1 genus of Copepods were found. The present study is expected to help achieve better and higher yield of fish by the fish farmer with increasing awareness regarding the hydrobiological feature of the pond and implement scientific management practices accordingly

  3. Characteristics of Momentum and Heat Transfer over Semiarid Grasslands with Different Grazing Intensities in Inner Mongolia, China

    Institute of Scientific and Technical Information of China (English)

    WANG Lei; LIU Hui-Zhi; Bettina KETZER; FENG Jian-Wu; Christian BERNHOFER

    2011-01-01

    The drag coefficient (Ca) and heat transfer coefficient (Ch) with the bulk transfer scheme are usually used to calculate the momentum and heat fluxes in meteorological models. The aerodynamic roughness length (z0m) and thermal roughness length (z0h) are two crucial parameters for bulk transfer equations. To improve the meteorological models, the seasonal and interannual variations of Z0m, Z0h, coefficient kB-1, Cd, and Ch were investigated based on eddy covariance data over different grazed semiarid grasslands of Inner Mongolia during the growing seasons (May to September) from 2005 to 2008. For an ungrazed Leymus chinensis grassland (ungrazed since 1979), Z0m and z0h had significant seasonal and in- terannual variations. Zorn was affected by the amount and distribution of rainfall, kB 1 exhibited a relatively negative variation compared with z0h, which indicates that the seasonal variation of z0h cannot be described by kB 1. To parameterize Zorn and z0h, the linear regressions between ln(z0m), ln(z0h), and the leaf area index (LAI) were performed with R2=0.71 and 0.83. The monthly average kB-1 was found to decrease linearly with LAI. The four-year averaged values of Ca and Ch were 4.5 × 10^-3 and 3.9× 10^-3, respectively. The monthly average Cd only varied by 8% while the variation of Ch was 18%, which reflects the dif- ferent impacts of dead vegetation on momentum and heat transfer at this natural grassland. Moreover, with the removal of vegetation cover, grazing intensities reduced Z0m, Z0h, Cd, and Ch.

  4. Study of Characteristics, risk factors and outcome for Ventilator Associated Pneumonia in Neonatal Intensive Care Unit patient

    Directory of Open Access Journals (Sweden)

    Mehdi Moradi

    2013-09-01

    Full Text Available Background: Ventilator Associated Pneumonia (VAP, developing in mechanically ventilated patients after 48 hours of mechanical ventilation, is the second most common nosocomial infection. Therefore, there is a vital need to study the etiology and risk factors associated with VAP in neonates.Methods: Neonates admitted to neonatal intensive care unit (NICU, over a period of one year and who required mechanical ventilation for more than 48 hours were enrolled consecutively into the study. Semi-quantitative assay of endotracheal aspirate was used for microbiological diagnoses of VAP. 105CFU/ml was taken as the cut off between evidence of pathological infection and colonization. The primary outcome measure was the development of VAP. Secondary outcome measures were length of mechanical ventilation, NICU length of stay, hospital cost, and death.Results: Thirty eight patients were enrolled (58% were boys and 42% were girls. 42% of neonates developed VAP. The most common VAP organisms identified were Acinetobacter baumanni (43%. On multiple regression analysis, duration of mechanical ventilation was associated with VAP (P=0.00. Patients with VAP had greater need for mechanical ventilation (18.7 vs 6 median days, longer NICU length of stay (39 vs 21.5 median days and higher total median hospital costs (79.5 vs 52 million rials than those without VAP. The mortality rate was not different between two groups.Conclusion: In mechanically ventilated neonates, those with VAP had a prolonged need for mechanical ventilation, a longer NICU stay, and a higher hospital costs. Longer mechanical ventilation was associated with an increased risk of developing VAP in these patients. Developing of VAP didn’t increase mortality in patients.

  5. Characterization of solar cells for space applications. Volume 7: Electrical characteristics of Spectrolab HEWAC BSF, textured, 10 ohm-cm, 225 micron solar cells as a function of intensity and temperature

    Science.gov (United States)

    Anspaugh, B. E.; Beckert, D. M.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1979-01-01

    Electrical characteristics of Spectrolab HEWAC BSF, textured, 10 ohm cm, 225 micron solar cells are presented in graphical and tabular format as a function of solar illumination intensity and temperature.

  6. Characterization of solar cells for space applications. Volume 12: Electrical characteristics of Solarex BSF, 2-ohm-cm, 50-micron solar cells (1978 pilot line) as a function of intensity, temperature, and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Beckert, D. M.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1980-01-01

    Electrical characteristics of Solarex back-surface-field, 2-ohm-cm, 50-micron N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity, temperature, and irradiation.

  7. Characterization of solar cells for space applications. Volume 10: Electrical characteristics of Spectrolab BSF, textured, 10 ohm-cm, 300 micron cells as a function of intensity, temperature and irradiation

    Science.gov (United States)

    Anspaugh, B. E.; Downing, R. G.; Miyahira, T. F.; Weiss, R. S.

    1979-01-01

    Electrical characteristics of textured, back surface field, 10 ohm cm, 300 micron N/P silicon solar cells are presented in graphical and tabular format as a function of solar illumination intensity, and temperature.

  8. Diffusion-weighted magnetic resonance imaging for the initial characterization of non-fatty soft tissue tumors: correlation between T2 signal intensity and ADC values

    Energy Technology Data Exchange (ETDEWEB)

    Gondim Teixeira, Pedro Augusto [Service d' Imagerie Guilloz, CHU Nancy, Nancy (France); Universite de Lorraine, IADI, UMR S 947, Vandoeuvre-les-Nancy (France); Gay, Frederique; Blum, Alain [Service d' Imagerie Guilloz, CHU Nancy, Nancy (France); Chen, Bailiang; Felblinger, Jacques [Universite de Lorraine, IADI, UMR S 947, Vandoeuvre-les-Nancy (France); Zins, Marie [University Versailles St-Quentin, Versailles (France); Inserm, Centre for research in Epidemiology and Population Health (CESP), U1018, Villejuif (France); Sirveaux, Francois [Centre Chirurgical Emile Galle, Service de Chirurgie Traumatologique et Orthopedique, Nancy (France)

    2016-02-15

    To evaluate the performance of quantitative diffusion-weighted imaging (DWI) correlated with T2 signal in differentiating non-fatty benign from malignant tumors. A total of 76 patients with a histologically confirmed non-fatty soft tissue tumors (46 benign and 30 malignant) were prospectively included in this ethics committee approved study. All patients signed an informed consent and underwent MRI with DWI with two b values (0 and 600). ADC values from the solid components of these tumors were obtained and were correlated with the lesion's signal intensity on T2-weighted fat-saturated sequences. ADC values were obtained from adjacent normal muscle to allow calculation of tumor/muscle ADC ratios. There were 58 hyperintense and 18 iso or hypointense lesions. All hypointense lesions were benign. The mean ADC values for benign and malignant tumors were 1.47 ± 0.54 x 10{sup -3} and 1.17 ± 0.38 x 10{sup -3} mm{sup 2}/s respectively (p < 0.005). The mean ADC ratio in benign iso or hypointense tumors was significantly lower than that of hyperintense ones (0.76 ± 0.21 versus 1.58 ± 0.82 - p < 0.0001). An ADC ratio lower than 0.915 was highly specific for malignancy (96.4 %), whereas an ADC ratio higher than 1.32 was highly sensitive for benign lesions (90 %). ADC analysis can be useful in the initial characterization of T2 hyperintense non-fatty soft tissue masses, although this technique alone is not likely to change patient management. (orig.)

  9. Low Intensity Pulsed Ultrasound (LIPUS) Influences the Multilineage Differentiation of Mesenchymal Stem and Progenitor Cell Lines through ROCK-Cot/Tpl2-MEK-ERK Signaling Pathway*

    Science.gov (United States)

    Kusuyama, Joji; Bandow, Kenjiro; Shamoto, Mitsuo; Kakimoto, Kyoko; Ohnishi, Tomokazu; Matsuguchi, Tetsuya

    2014-01-01

    Mesenchymal stem cells (MSCs) are pluripotent cells that can differentiate into multilineage cell types, including adipocytes and osteoblasts. Mechanical stimulus is one of the crucial factors in regulating MSC differentiation. However, it remains unknown how mechanical stimulus affects the balance between adipogenesis and osteogenesis. Low intensity pulsed ultrasound (LIPUS) therapy is a clinical application of mechanical stimulus and facilitates bone fracture healing. Here, we applied LIPUS to adipogenic progenitor cell and MSC lines to analyze how multilineage cell differentiation was affected. We found that LIPUS suppressed adipogenic differentiation of both cell types, represented by impaired lipid droplet appearance and decreased gene expression of peroxisome proliferator-activated receptor γ2 (Pparg2) and fatty acid-binding protein 4 (Fabp4). LIPUS also down-regulated the phosphorylation level of peroxisome proliferator-activated receptor γ2 protein, inhibiting its transcriptional activity. In contrast, LIPUS promoted osteogenic differentiation of the MSC line, characterized by increased cell calcification as well as inductions of runt-related transcription factor 2 (Runx2) and Osteocalcin mRNAs. LIPUS induced phosphorylation of cancer Osaka thyroid oncogene/tumor progression locus 2 (Cot/Tpl2) kinase, which was essential for the phosphorylation of mitogen-activated kinase kinase 1 (MEK1) and p44/p42 extracellular signal-regulated kinases (ERKs). Notably, effects of LIPUS on both adipogenesis and osteogenesis were prevented by a Cot/Tpl2-specific inhibitor. Furthermore, effects of LIPUS on MSC differentiation as well as Cot/Tpl2 phosphorylation were attenuated by the inhibition of Rho-associated kinase. Taken together, these results indicate that mechanical stimulus with LIPUS suppresses adipogenesis and promotes osteogenesis of MSCs through Rho-associated kinase-Cot/Tpl2-MEK-ERK signaling pathway. PMID:24550383

  10. High-performance liquid chromatography coupled to direct analysis in real time mass spectrometry: investigations on gradient elution and influence of complex matrices on signal intensities.

    Science.gov (United States)

    Beissmann, Susanne; Buchberger, Wolfgang; Hertsens, Robert; Klampfl, Christian W

    2011-08-01

    Direct analysis in real time (DART) time-of-flight mass spectrometry (TOF-MS) has been tested for its suitability as a detector for gradient elution HPLC. Thereby a strong dependency of signal intensity on the amount of organic solvent present in the eluent could be observed. Adding a make-up liquid (iso-propanol) post-column to the HPLC effluent greatly enhanced detection limits for early eluting compounds. Limits of detection achieved employing this approach were in the range of 7-27 μg L(-1) for the parabene test mixture and 15-87 μg L(-1) for the pharmaceuticals. In further investigations DART ionization was compared to several other widely used atmospheric pressure ionization methods with respect to signal suppression phenomena occurring in when samples with problematic matrices are analyzed. For this purpose extracts from environmental and waste water samples were selected as model matrices which were subsequently spiked with a set of six substances commonly present in personal care products as well as six pharmaceuticals at concentration levels between 100 μg L(-1) and 500 μg L(-1) corresponding to 100 ng L(-1) and 500 ng L(-1) respectively in the original sample. With ionization suppression of less than 11% for most analytes investigated, DART ionization showed similar to even somewhat superior behavior compared to atmospheric pressure chemical ionization (APCI) and atmospheric pressure photo ionization (APPI) for the Danube river water extract; for the more challenging matrix of the sewage plant effluent extract DART provided better results with ion suppression being less than 11% for 9 out of 12 analytes while values for APCI were lying between 20% and >90%. Electrospray ionization (ESI) was much more affected by suppression effects than DART with values between 26% and 80% for Danube river water; in combination with the sewage plant effluent matrix suppression >50% was observed for all analytes.

  11. Damaging biting behaviors in intensively kept rearing gilts: the effect of jute sacks and relations with production characteristics.

    Science.gov (United States)

    Ursinus, W W; Wijnen, H J; Bartels, A C; Dijvesteijn, N; van Reenen, C G; Bolhuis, J E

    2014-11-01

    Pigs may display biting behavior directed at pen mates, resulting in body damage such as tail wounds. We assessed the suitability of jute sacks (hung vertically at wall) to reduce biting behaviors and tail wounds in rearing gilts. Additionally, we assessed several characteristics of different types of tail biters. Tail docked rearing gilts originated from 72 litters, which were kept in partly slatted pens with jute sacks (J) or barren control pens (CON; 36 litters per treatment). Tail and ear damage were observed at weaning (4 wk) and during the weaner and rearing phase (17 J and 19 CON pens). Sow (dam) damage was also considered. Biting behaviors (tail, ear, and other) were observed during the weaner and rearing phase. Weight was recorded at birth, weaning, and end of the weaner phase and ADG was calculated from birth till weaning and from weaning till 9 wk. Furthermore, estimated breeding values for litter size, litter birth weight, back fat, and growth between birth and ∼ 105 kg, and ∼ 25 to 105 kg were determined. Jute sacks reduced tail and ear damage at weaning (both P Jute sacks also reduced tail damage post-weaning (P jute sack (P jute sacks may profoundly reduce damaging behaviors and tail wounds in rearing gilts, probably because they partly meet the behavioral need of pigs for rooting and chewing. Furthermore, (tail) biting is associated with production level of the gilts (phenotypically and genetically), which suggests a role for breeding programs and additional research focusing on metabolic demands of (tail) biting pigs.

  12. Clinical characteristics of children with snakebite poisoning and management of complications in the pediatric intensive care unit.

    Science.gov (United States)

    Ozay, Gonca; Bosnak, Mehmet; Ece, Aydin; Davutoglu, Mehmet; Dikici, Bunyamin; Gurkan, Fuat; Bosnak, Vuslat; Haspolat, Kenan

    2005-12-01

    Venomous snakebite is an emergency condition with high morbidity and mortality in childhood. Nearly all venomous snakes in Turkey are members of the Viperidae family and show poisonous local and hematotoxic effects. A total of 77 children (mean age 9.9 +/- 2.9 years; age range 3-14 years) with venomous snakebites were investigated. General characteristics of the children, species of the snakes, localization of the bite, clinical and laboratory findings, treatment approaches, complications and prognosis were evaluated. The male to female ratio was 1.4. Ninety-one per cent of cases were from rural areas. Most of the bites were seen in May and June. Mean duration between snakebites and admissions to our department was 13 +/- 6.5 h. According to a clinical grading score, 57.1% of patients presented to us as grade II. Mean leukocyte count, aspartate aminotransferase, lactate dehydrogenase, creatinine phosphokinase and protrombin time levels were above the normal ranges and mean activated partial tromboplastin time was below the normal range. Platelet counts inversely correlated with the grading score and duration of hospitalization. The most common complication that occurred during the treatment was tissue necrosis (13%). The mean hospital stay time was 6.3 +/- 6 days. Three children with disseminated intravascular coagulation died. Fasciotomies were performed to seven (9.1%) children due to compartment syndrome. Of 10 children with tissue necrosis, three (3.9%) had finger amputation and seven (9.1%) had toe amputation. Higher grading score on admission, platelet count below 120 000/mm3, AST over 50 IU/L and existence of evident ecchymosis were found as significant risk factors for development of serious complications by logistic regression analysis. Snakebite poisoning is an emergency medical condition that is particularly important in childhood. The envenomations are still considerable public health problems with a high morbidity and mortality in rural areas of Turkey.

  13. Incidentally detected enhancing lesions found in breast MRI: analysis of apparent diffusion coefficient and T2 signal intensity significantly improves specificity

    Energy Technology Data Exchange (ETDEWEB)

    Arponen, Otso; Masarwah, Amro; Taina, Mikko [Kuopio University Hospital, Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Kuopio University Hospital, University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Sutela, Anna; Koenoenen, Mervi; Hakumaeki, Juhana; Sudah, Mazen [Kuopio University Hospital, Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Sironen, Reijo [Kuopio University Hospital, Kuopio University Hospital, Department of Pathology, PO Box 1777, Kuopio (Finland); Kuopio University Hospital, University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Clinical Pathology and Forensic Medicine, PO Box 1777, Kuopio (Finland); University of Eastern Finland, Cancer Center of Eastern Finland, Kuopio (Finland); Vanninen, Ritva [Kuopio University Hospital, Kuopio University Hospital, Diagnostic Imaging Centre, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); Kuopio University Hospital, University of Eastern Finland, Institute of Clinical Medicine, School of Medicine, Department of Clinical Radiology, PO Box 1777, Kuopio (Finland); University of Eastern Finland, Cancer Center of Eastern Finland, Kuopio (Finland)

    2016-12-15

    To evaluate the value of adding T2- and diffusion-weighted imaging (DWI) to the BI-RADS registered classification in MRI-detected lesions. This retrospective study included 112 consecutive patients who underwent 3.0T structural breast MRI with T2- and DWI on the basis of EUSOMA recommendations. Morphological and kinetic features, T2 signal intensity (T2 SI) and apparent diffusion coefficient (ADC) findings were assessed. Thirty-three (29.5 %) patients (mean age 57.0 ± 12.7 years) had 36 primarily MRI-detected incidental lesions of which 16 (44.4 %) proved to be malignant. No single morphological or kinetic feature was associated with malignancy. Both low T2 SI (P = 0.009) and low ADC values (≤0.87 x 10{sup -3} mm{sup 2}s{sup -1}, P < 0.001) yielded high specificity (80.0 %/80.0 %). The BI-RADS classification supplemented with information from DWI and T2-WI improved the diagnostic performance of the BI-RADS classification as sensitivity remained 100 % and specificity improved from 30 % to 65.0 %. The numbers of false positive lesions declined from 39 % (N = 14) to 19 % (N = 7). MRI-detected incidental lesions may be challenging to characterize as they have few specific malignancy indicating features. The specificity of MRI can be improved by incorporating T2 SI and ADC values into the BI-RADS assessment. (orig.)

  14. Impact of low signal intensity assessed by cine magnetic resonance imaging on detection of poorly viable myocardium in patients with prior myocardial infarction.

    Science.gov (United States)

    Ota, Shingo; Tanimoto, Takashi; Orii, Makoto; Hirata, Kumiko; Shiono, Yasutsugu; Shimamura, Kunihiro; Matsuo, Yoshiki; Yamano, Takashi; Ino, Yasushi; Kitabata, Hironori; Yamaguchi, Tomoyuki; Kubo, Takashi; Tanaka, Atsushi; Imanishi, Toshio; Akasaka, Takashi

    2015-05-13

    Late gadolinium enhancement magnetic resonance imaging (LGE-MRI) has been established as a modality to detect myocardial infarction (MI). However, the use of gadolinium contrast is limited in patients with advanced renal dysfunction. Although the signal intensity (SI) of infarct area assessed by cine MRI is low in some patients with prior MI, the prevalence and clinical significance of low SI has not been evaluated. The aim of this study was to evaluate how low SI assessed by cine MRI may relate to the myocardial viability in patients with prior MI. Fifty patients with prior MI underwent both cine MRI and LGE-MRI. The left ventricle was divided into 17 segments. The presence of low SI and the wall motion score (WMS) of each segment were assessed by cine MRI. The transmural extent of infarction was evaluated by LGE-MRI. LGE was detected in 329 of all 850 segments (39%). The low SI assessed by cine MRI was detected in 105 of 329 segments with LGE (32%). All segments with low SI had LGE. Of all 329 segments with LGE, the segments with low SI showed greater transmural extent of infarction (78 [72 - 84] % versus 53 [38 - 72] %, P cine MRI may be effective for detecting poorly viable myocardium in patients with prior MI.

  15. Increased signal intensity of prostate lesions on high b-value diffusion-weighted images as a predictive sign of malignancy

    Energy Technology Data Exchange (ETDEWEB)

    Quentin, Michael; Schimmoeller, Lars; Antoch, Gerald; Blondin, Dirk [University Dusseldorf, Medical Faculty, Department of Diagnostic and Interventional Radiology, Dusseldorf (Germany); Arsov, Christian; Rabenalt, Robert; Albers, Peter [University Dusseldorf, Medical Faculty, Department of Urology, Dusseldorf (Germany)

    2014-01-15

    The evaluation of lesions detected in prostate magnetic resonance imaging (MRI) with increased signal intensity (SI) on high b-value diffusion-weighted images as a sign of malignancy. One hundred and three consecutive patients with prostate MRI examination and MRI-guided in-bore biopsy were retrospectively included in the study. MRI-guided in-bore biopsy histologically confirmed prostate cancer in 50 patients (n = 92 lesions). The other 53 patients (n = 122 lesions) had negative bioptical results. In patients with histologically confirmed prostate cancer, 46 of the 92 lesions had visually increased SI on the high b-value images compared with the peripheral zone (SI = +27 ± 16%) or the central gland (SI = +37 ± 19%, P < 0.001 respectively). In patients with a negative biopsy, ten of the 122 lesions had visually increased SI (compared with the peripheral zone, SI = +29 ± 18%, and with the central gland, SI = +41 ± 15%, P < 0.001 respectively). Neither the apparent diffusion coefficient (ADC) values nor the Gleason Score of lesions with increased SI were significantly different from lesions without increased SI. Visually increased SI on the high b-value images of diffusion-weighted imaging using standard b-values is a sign of malignancy but can occasionally also be a feature of benign lesions. However, it does not indicate more aggressive tumours. (orig.)

  16. Relationship between exercise-induced heart rate increase and the formation of microbubbles and high-intensity transient signals in mechanical heart valve implanted patients.

    Science.gov (United States)

    Sünbül, Ayşegül; Kırbaş, Ahmet; Tanrıkulu, Nursen; Sengül, Cihan; Dağdeviren, Bahadır; Işık, Omer

    2014-08-29

    The formation and collapse of vapor-filled bubbles near a mechanical heart valve is called cavitation. Microbubbles can be detected in vivo by doppler ultrasonography (USG) as HITS (high intensity transient signals) in cranial circulation. We investigated the relationship between exercise induced heart rate increase and HITS formation in cranial circulation. Thirty-nine mechanical heart valve implanted (8 aortic valve replacement (AVR) + mitral valve replacement (MVR), 9 AVR, 22 MVR) patients aged 18-80 years old were included in our study. Microbubbles were counted in the left ventricular cavity via transthoracic echocardiography at rest per cardiac cycle. Afterwards transcranial Doppler USG was performed and HITS were counted in each patient's middle cerebral artery at 5 min duration. Subsequently an exercise test according to the Bruce protocol was performed. After achieving maximal heart rate, microbubbles in the left ventricle and HITS were counted again. Microbubbles in the left ventricle and transcranial HITS increased after exercise significantly compared to resting values (15.79 ±10.91 microbubbles/beat vs. 26.51 ±18.00 microbubbles/beat, p exercise (r = 0.55, p increasing as the heart rate increased and more HITS were propelled to the cerebral circulation. As previously shown, HITS can alter cognitive functions. Therefore heart rate control is essential in mechanical heart valve patients to protect neurocognitive functions.

  17. Volume Change and Liver Parenchymal Signal Intensity in Gd-EOB-DTPA-Enhanced Magnetic Resonance Imaging after Portal Vein Embolization prior to Hepatectomy

    Directory of Open Access Journals (Sweden)

    Ayako Akiba

    2014-01-01

    Full Text Available Purpose. To investigate the liver volume change and the potential of early evaluation by contrast-enhanced magnetic resonance imaging (MRI using gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA after portal vein embolization (PVE. Materials and Methods. Retrospective evaluations of computed tomography (CT volumetry of total liver and nonembolized areas were performed before and 3 weeks after PVE in 37 cases. The percentage of future liver remnant (%FLR and the change ratio of %FLR (%FLR ratio were calculated. Prospective evaluation of signal intensities (SIs was performed to estimate the role of Gd-EOB-DTPA-enhanced MRI as a predictor of hypertrophy in 16 cases. The SI contrast between embolized and nonembolized areas was calculated 1 week after PVE. The change in SI contrast before and after PVE (SI ratio was also calculated in 11 cases. Results. %FLR ratio significantly increased, and SI ratio significantly decreased (both P<0.01. There were significant negative correlations between %FLR and SI contrast and between %FLR and SI ratio (both P<0.01. Conclusion. Hypertrophy in the nonembolized area after PVE was indicated by CT volumetry, and measurement of SI contrast and SI ratio in Gd-EOB-DTPA-enhanced MRI early after PVE may be useful to predict the potential for hepatic hypertrophy.

  18. Preoperative ultrasound-guided needle biopsy of 63 uterine tumors having high signal intensity upon T2-weighted magnetic resonance imaging.

    Science.gov (United States)

    Tamura, Ryo; Kashima, Katsunori; Asatani, Mina; Nishino, Koji; Nishikawa, Nobumichi; Sekine, Masayuki; Serikawa, Takehiro; Enomoto, Takayuki

    2014-07-01

    The differential diagnosis between uterine sarcoma and benign leiomyoma is difficult when made only by magnetic resonance imaging (MRI); it usually requires an additional preoperative diagnostic procedure. We report our results using ultrasound-guided needle biopsy for these types of uterine tumors. Ultrasound-guided needle biopsy was performed on 63 patients with uterine smooth muscle tumors suspected of malignancy by MRI. We compared the results of presurgical biopsy against the postsurgical pathology of the tumor. Among 63 patients with a high signal intensity of the uterine tumor on T2-weighted MRI (1 case was undetermined), 12 cases (19.3%) were diagnosed by the needle biopsy as malignant, and 51 cases (80.6%) were benign. Among the 12 diagnosed as malignant tumors, 11 had surgery performed, and one was treated with chemotherapy. Among the 51 patients diagnosed with a benign tumor, 27 had surgery performed, and 24 were put on a wait-and-see clinical follow-up schedule. One of the 27 surgical patients with a benign tumor had a postsurgical diagnosis of a low-grade endometrial stromal sarcoma. In the 38 cases where surgery was performed, we found the sensitivity, specificity, and the positive and negative predictive values of the needle biopsy were 91.7%, 100%, 100%, and 96.2%, respectively. Ultrasound-guided needle biopsy may be a reliable preoperative diagnostic procedure for uterine tumors with suspected malignancy.

  19. Relationship between the Carotid Plaque T1 Relaxation Time and the Plaque-to-Muscle Signal Intensity Ratio on Black-Blood Magnetic Resonance Imaging Scans.

    Science.gov (United States)

    Eto, Ayumu; Kinoshita, Yoshimasa; Matsumoto, Yoshihisa; Kiyomi, Fumiaki; Iko, Minoru; Nii, Kouhei; Tsutsumi, Masanori; Sakamoto, Kimiya; Aikawa, Hiroshi; Kazekawa, Kiyoshi

    2016-11-01

    Black-blood magnetic resonance imaging (BB-MRI) is useful for the characterization and assessment of carotid artery plaques. The plaque-to-muscle signal intensity (SI) ratio (plaque/muscle ratio [PMR]) is used widely to evaluate plaques. However, the correlation between the PMR and the T1 relaxation time needs to be determined. We measured the T1 relaxation time of carotid plaques using T1 mapping and compared the results with the PMR on BB-MRI scans. Between April 2014 and July 2015, 20 patients with carotid artery stenosis were treated by carotid artery stenting. All patients underwent preoperative magnetic resonance plaque imaging. The ratio of the plaque SI to the sternocleidomastoid muscle was calculated on T1-weighted BB-MRI scans. T1 mapping was performed in the region where the vessel was narrowest using the inversion recovery technique. The T1 relaxation time was recorded to determine whether there was a correlation with the PMR. The plaque T1 value was 577.3 ± 143.2 milliseconds; the PMR value obtained on BB-MRI scans was 1.23 ± .27. There was a statistically significant decrease in the T1 value as the PMR increased (P relaxation time was well correlated with the PMR on BB-MRI scans, the evaluation of vulnerable plaques using the PMR was reliable and convenient. Copyright © 2016 National Stroke Association. Published by Elsevier Inc. All rights reserved.

  20. The obtaining of statistical characteristics of informative features of signals in the Autonomous information systems using neural networks

    Directory of Open Access Journals (Sweden)

    V. K. Hohlov

    2014-01-01

    Full Text Available The article studies a neural network approach to obtain the statistical characteristics of the input vector implementations of signal and noise at ill-conditioned matrices of correlation moments to solve the problems to select and reduce the vector dimensions of informative features at detection and recognition of signals and noise based on regression methods.A scientific novelty is determined by applying neural network algorithms for the efficient solution of problems to select the informative features and determine the parameters of regression algorithms in terms of the degeneracy or ill-conditioned data with unknown expectation and covariance matrices.The article proposes to use a single-layer neural network with no zero weights and activation functions to calculate the initial regression characteristics and the mean-square value error of multiple initial regression representations, which are necessary to justify the selection of informative features, reduce a dimension of sign vectors and implement the regression algorithms. It is shown that when excluding direct links between the inputs and their corresponding neurons, in the training network the weight coefficients of neuron inputs are the coefficients of initial multiple regression, the error meansquare value of multiple initial regression representations is calculated at the outputs of neurons. The article considers conditionality of the problem to calculate the matrix that is inverse one for matrix of correlation moments. It defines a condition number, which characterizes the relative error of stated task.The problem concerning the matrix condition of the correlation moment of informative signal features and noise arises when solving the problem to find the multiple coefficients of initial regression (MCIR and the residual mean-square values of the multiple regression representations. For obtaining the MCIR and finding the residual mean-square values the matrix of correlation moments of

  1. Clinical characteristics and vital and functional prognosis of out-of-hospital cardiac arrest survivors admitted to five cardiac intensive care units.

    Science.gov (United States)

    Loma-Osorio, Pablo; Aboal, Jaime; Sanz, Maria; Caballero, Ángel; Vila, Montserrat; Lorente, Victoria; Sánchez-Salado, José Carlos; Sionis, Alessandro; Curós, Antoni; Lidón, Rosa-Maria

    2013-08-01

    Survivors of out-of-hospital cardiac arrest constitute an increasing patient population in cardiac intensive care units. Our aim was to characterize these patients and determine their vital and functional prognosis in accordance with the latest evidence. A multicenter, prospective register was constructed with information from patients admitted to 5 cardiac intensive care units from January 2010 through January 2012 with a diagnosis of resuscitated out-of-hospital cardiac arrest. The information included clinical status, cardiac arrest characteristics, in-hospital course, and vital and neurologic status at discharge and at 6 months. A total of 204 patients were included. In 64% of cases, a first shockable rhythm was identified. The time to return of spontaneous circulation was 29 (18) min. An etiologic diagnosis was made in 86% of patients; 44% were discharged with no neurologic sequelae; 40% died in the hospital. At 6 months, 79% of survivors at discharge were still alive and neurologically intact with minimal sequelae. Short resuscitation time, first recorded rhythm, pH on admission >7.1, absence of shock, and use of hypothermia were the independent variables associated with a good neurologic prognosis. Half the patients who recovered from out-of-hospital cardiac arrest had good neurologic prognosis at discharge, and 79% of survivors were alive and neurologically intact after 6 months of follow-up. Copyright © 2013 Sociedad Española de Cardiología. Published by Elsevier Espana. All rights reserved.

  2. Intranodular signal intensity analysis of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd–EOB–DTPA-enhanced MRI

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, Satoshi, E-mail: satoshik@staff.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Matsui, Osamu, E-mail: matsuio@med.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Gabata, Toshifumi, E-mail: gabata@med.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Koda, Wataru, E-mail: wkoda@staff.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Minami, Tetsuya, E-mail: tminami@staff.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Ryu, Yasuji, E-mail: yryu-kanazawa@umin.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Kozaka, Kazuto, E-mail: k-kozaka@staff.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan); Kitao, Azusa, E-mail: azusa@med.kanazawa-u.ac.jp [Dept of Radiology, Kanazawa University School of Medicine, 13-1, Takara Machi, Kanazawa 920-8641 (Japan)

    2012-12-15

    Objectives: To analyze intranodular signal intensity pattern of hypovascular high-risk borderline lesions of HCC that illustrate multi-step hepatocarcinogenesis within the nodule on Gd–EOB–DTPA-enhanced MRI. Methods: A total of 73 nodules showing hypervascular foci in hypovascular high-risk borderline lesions identified by angiography-assisted CT were included in this study. The intranodular signal intensities of both the hypervascular foci and the hypovascular high-risk borderline lesions were evaluated on hepatobiliary-phase EOB-enhanced MRI obtained 20 min after intravenous injection of contrast media. Results: Among 59 hypervascular foci within hypointense hypovascular high-risk borderline lesions, 6 showed more hypointensity, 32 isointensity, and 21 hyperintensity compared to the surrounding hypointense, hypovascular portion of the nodules. Among 14 hypervascular foci within isointense hypovascular high-risk borderline lesions, 5 showed isointensity, and 9 hypointensity compared to the surrounding isointense hypovascular high-risk borderline lesions. No hypervascular foci showed hyperintensity compared to the surrounding isointense hypovascular high-risk borderline lesions. Conclusions: In most of the hypovascular high-risk borderline lesions containing hypervascular foci within the nodule, the signal intensity was decreased in hypervascular foci as compared with hypovascular high-risk borderline lesions and the surrounding background liver parenchyma. This supports the concept of signal intensity decrease during the dedifferentiation process in multistep hepatocarcinogenesis. However, around 30% of the nodules did not follow this rule, and hypervascular foci showed hyperintensity relative to the hypovascular high-risk borderline lesions.

  3. Correlation between magnetic resonance T2 image signal intensity ratio and cell apoptosis in a rabbit spinal cord cervical myelopathy model

    Institute of Scientific and Technical Information of China (English)

    Ma Lei; Zhang Di; Chen Wei; Shen Yong; Zhang Yingze; Ding Wenyuan; Zhang Wei

    2014-01-01

    Background Cervical spondylotic myelopathy (CSM) is a common cause of disability in elderly patients.Previous studies have shown that spinal cord cell apoptosis due to spinal cord compression plays an important role in the pathology of myelopathy.Although changes in magnetic resonance imaging (MRI) T2 signal intensity ratio (SIR) are considered to be an indicator of CSM,little information is published supporting the correlation between changes in MRI signal and pathological changes.This study aims to testify the correlation between MRI T2 SIR changes and cell apoptosis using a CSM animal model.Methods Forty-eight rabbits were randomly assigned to four groups:one control group and three experimental chronic compression groups,with each group containing 12 animals.Chronic compression of the cervical spinal cord was implemented in the experimental groups by implanting a screw in the C3 vertebra.The control group underwent sham surgery.Experimental groups were observed for 3,6,or 9 months after surgery.MRI T2-weighted SIR Tarlov motor scores and cortical somatosensory-evoked potentials (CSEPs) were periodically monitored.At each time point,rabbits from one group were sacrificed to determine the level of apoptosis by histology (n=6) and Western blotting (n=6).Results Tarlov motor scores in the compression groups were lower at all time points than the control group scores,with the lowest score at 9 months (P <0.001).Electrophysiological testing showed a significantly prolonged latency in CSEP in the compression groups compared with the control group.All rabbits in the compression groups showed higher MRI T2 SIR in the injury epicenter compared with controls,and higher SIR was also found at 9 months compared with 3 or 6 months.Histological analysis showed significant apoptosis in the spinal cord tissue in the compression groups,but not in the control group.There were significant differences in apoptosis degree over time (P <0.001),with the 9-month group displaying the

  4. Risk factors for device-associated infection related to organisational characteristics of intensive care units: findings from the Korean Nosocomial Infections Surveillance System.

    Science.gov (United States)

    Kwak, Y G; Lee, S-O; Kim, H Y; Kim, Y K; Park, E S; Jin, H Y; Choi, H J; Jeong, S Y; Kim, E S; Ki, H K; Kim, S R; Lee, J Y; Hong, H K; Kim, S; Lee, Y S; Oh, H-B; Kim, J M

    2010-07-01

    Device-associated infections (DAIs) have been the major causes of morbidity and mortality of patients in intensive care units (ICUs). This study evaluated the risk factors for DAIs in ICUs. Ninety-six medical or surgical ICUs of 56 hospitals participated in the Korean Nosocomial Infections Surveillance System between July 2007 and June 2008. The occurrence of catheter-associated urinary tract infection (CAUTI), central line-associated bloodstream infection (CABSI), and ventilator-associated pneumonia (VAP) were monitored and DAI rates were calculated. Data associated with ICU characteristics were collected and Poisson regression was used for statistical analysis. Rates of CAUTI, CABSI, and VAP were 3.87 per 1000 urinary catheter days, 2.23 per 1000 central line days, and 1.89 per 1000 mechanical ventilator days, respectively. Rates of CAUTI were higher in ICUs in Seoul (P=0.032) and ICUs of major teaching hospitals (P=0.010). The ICUs of university-affiliated hospitals showed lower CAUTI rates (P=0.013). CABSI rates were higher in Seoul (P=0.001) and in medical ICUs (P=0.026). VAP rates were lower in ICUs of hospitals with more than 900 beds compared with hospitals with 400-699 beds (P=0.026). VAP rates were higher in surgical ICUs (Pinfection control professional (P=0.003). The organisational and institutional characteristics of ICUs may influence DAI rates and there is a need for improvement in the incidence of VAP, CAUTI or CABSI.

  5. Pancreatic carcinoma coexisting with chronic pancreatitis versus tumor-forming pancreatitis: Diagnostic utility of the time-signal intensity curve from dynamic contrast-enhanced MR imaging

    Institute of Scientific and Technical Information of China (English)

    Yoshitsugu Tajima; Tamotsu Kuroki; Ryuji Tsutsumi; Ichiro Isomoto; Masataka Uetani; Takashi Kanematsu

    2007-01-01

    AIM: To evaluate the ability of the time-signal intensity curve (TIC) of the pancreas obtained from dynamic contrast-enhanced magnetic resonance imaging (MRI) for differentiation of focal pancreatic masses, especially pancreatic carcinoma coexisting with chronic pancreatitis and tumor-forming pancreatitis.METHODS: Forty-eight consecutive patients who underwent surgery for a focal pancreatic mass, including pancreatic ductal carcinoma (n = 33), tumor-forming pancreatitis (n = 8), and islet cell tumor (n = 7), were reviewed. Five pancreatic carcinomas coexisted with longstanding chronic pancreatitis. The pancreatic TICs were obtained from the pancreatic mass and the pancreatic parenchyma both proximal and distal to the mass lesion in each patient, prior to surgery, and were classified into 4 types according to the time to a peak: 25 s and 1, 2, and 3 min after the bolus injection of contrast material, namely, type-Ⅰ,Ⅱ,Ⅲ,and IV, respectively, and were then compared to the corresponding histological pancreatic conditions.RESULTS: Pancreatic carcinomas demonstrated type-m (n = 13) or IV (n = 20) TIC. Tumor-forming pancreatitis showed type-Ⅱ(n = 5) or Ⅲ(n = 3) TIC. All islet cell tumors revealed type-1. The type-IV TIC was only recognized in pancreatic carcinoma, and the TIC of carcinoma always depicted the slowest rise to a peak among the 3 pancreatic TICs measured in each patient, even in patients with chronic pancreatitis.CONCLUSION: Pancreatic TIC from dynamic MRI provides reliable information for distinguishing pancreatic carcinoma from other pancreatic masses, and may enable us to avoid unnecessary pancreatic surgery and delays in making a correct diagnosis of pancreatic carcinoma, especially, in patients with longstanding chronic pancreatitis.

  6. Position of increased signal intensity in the spinal cord on MR images: does it predict the outcome of cervical spondylotic myelopathy?

    Institute of Scientific and Technical Information of China (English)

    SHEN Hong-xing; LI Ling; YANG Zhi-gao; HOU Tie-sheng

    2009-01-01

    Background Increased signal intensity (ISI) in the spinal cord on T2-weighted MR images has been reported in some previous researches, however no study focused on the position of the ISI in the spinal cord and its potential value. The aim of this study was to investigate the correlation between ISI position and the outcome of surgical treatment for cervical spondylotic myelopathy (CSM) patients.Methods A retrospective study was conducted. Pre- and post-operative clinical status was evaluated by modified Japanese Orthopaedic Association (JOA) score. ISI was evaluated according to the T2-weighted sequences. The JOA score and the recovery ratios among patients with ISI in gray matter (group A), in both gray and white matter (group B), and ISI-negative group were compared.Results Totally 64 patients were enrolled in this retrospective study. Preoperative JOA score of ISI positive and negative group had significant difference, but the recovery ratios had no significant difference (the recovery ratios of the two groups in week 1, week 26, and week 104 were (21.54±14.65)%, (50.56±14.76)%, (59.23±13.08)% and (20.25±14.32)%, (54.46±23.16)% and (61.26±29.4)%, respectively; P>0.05). The recovery ratios of negative group and group A in week 104 were superior to group B (the recovery ratios of negative group, group A, and group B in week 104 were (61.26±E29.49)%, (65.35±11.36)%, and (50.33±10.20)%, respectively; P <0.05). Conclusions Patients with ISI in the gray matter alone on T2-weighted MR images did not have significantly different surgical outcomes compared with those without ISI. Patients with ISI in both gray and white matter had surgical outcomes that were worse than those without ISI.

  7. Altimetric sampling and mapping procedures induce spatial and temporal aliasing of the signalcharacteristics of these aliasing effects in the Mediterranean Sea

    Directory of Open Access Journals (Sweden)

    F. Briol

    2007-07-01

    Full Text Available This study deals with spatial and temporal aliasing of the sea surface signal and its restitution with altimetric maps of Sea Level Anomalies (SLA in the Mediterranean Sea. Spatial and temporal altimetry sampling, combined with a mapping process, are unable to restore high-frequency (HF surface variability. In the Mediterranean Sea, it has been shown that signals whose intervals are less than 30–40 days are largely underestimated, and the residual HF restitution signal contains characteristic errors which make it possible to identify the spatial and temporal sampling of each satellite. The origin of these errors is relatively complex. Three main effects are involved: the sampling of the HF long-wavelength (LW signal, the correction of this signal's aliasing and the mapping procedure. – The sampling depends on the characteristics of the satellites considered, but generally induces inter-track bias that needs to be corrected before the mapping procedure is applied. – Correcting the aliasing of the HF LW signal, carried out using a barotropic model output and/or an empirical method, is not perfect. In fact, the baroclinic part of the HF LW signal is neglected and the numerical model's capabilities are limited by the spatial resolution of the model and the forcing. The empirical method cannot precisely control the corrected signal. – The mapping process, which is optimised to improve restitution of mesoscale activity, does not propagate the LW signal far from the satellite tracks. Even though these residual errors are very low with respect to the total signal, their signature may be visible on maps of SLAs. However, these errors can be corrected by more careful consideration of their characteristics in terms of spatial distribution induced by altimetric along-track sampling. They can also be attenuated by increasing the altimetric spatial coverage through the merging of different satellites. Ultimately, the HF signal, which is missing in

  8. Effects of different light intensities on Strobilanthes cusia photosynthetic characteristics in Fujian Province%光强对福建马蓝光合特性的影响

    Institute of Scientific and Technical Information of China (English)

    宁书菊; 张英娇; 林建勇; 魏道智

    2012-01-01

    以药用植物福建马蓝(Strobilanthes cusia)为材料,研究不同光强对福建马蓝光合特性的影响.结果表明,不同光强(100%自然光照、30%自然光照、6%自然光照)处理下,马蓝叶片的光合速率日变化均呈双峰型曲线.3种光强处理中,以30%自然光强下光合速率最高.与自然光照相比,遮荫条件下(30%自然光照、6%自然光照)马蓝具有较高的初始荧光(Fm)、PSⅡ的光化学活性(Fv/Fo)、原初光能转换效率(Fv/Fm)、光化学量子产额(Yield)、光化学淬灭系数(qP)和较低的非光化学淬灭系数(qN);遮荫条件下,马蓝是通过提高叶片叶绿素a/b含量,降低光补偿点,提高光系统中光反应中心光化学活性,增强系统的光能转换效率来提高光合速率,以弥补弱光条件下光能的不足.试验发现遮荫条件下,光合速率和气孔导度相关度较低,非气孔因素应是遮阴影响马蓝光合的主要因子,同时发现遮荫使得马蓝气孔对于光照强度响应的敏感度显著增加.光强对马蓝叶片药效学成分靛蓝、靛玉红中靛蓝含量影响不显著,100%自然光处理的靛玉红含量大于两个遮荫处理.福建马蓝适宜于30%自然光照条件下的间作套种或林下栽培,对其生长有利.%"Jian Indigo" made from stem and leave of Strobilanthes cusia is one of the genuine drugs in Fujian Province. S. cusia original plant occurs in dank conditions and grows in forests or generally shaded conditions. Although light intensity is the main cultivation factor of 5. cusia, studies on the characteristics of S. cusia photosynthesis under different light intensities were limited. Hence studies on different light intensities (full sunlight, 30% sunlight and 6% sunlight) were carried out to investigate the effects of light intensity on photosynthetic characteristics of S. cusia in Fujian Province. Results showed that diurnal variations in photosynthetic rates under three treatments tracked

  9. Dynamic characteristics of laser Doppler flowmetry signals obtained in response to a local and progressive pressure applied on diabetic and healthy subjects

    Science.gov (United States)

    Humeau, Anne; Koitka, Audrey; Abraham, Pierre; Saumet, Jean-Louis; L'Huillier, Jean-Pierre

    2004-09-01

    In the biomedical field, the laser Doppler flowmetry (LDF) technique is a non-invasive method to monitor skin perfusion. On the skin of healthy humans, LDF signals present a significant transient increase in response to a local and progressive pressure application. This vasodilatory reflex response may have important implications for cutaneous pathologies involved in various neurological diseases and in the pathophysiology of decubitus ulcers. The present work analyses the dynamic characteristics of these signals on young type 1 diabetic patients, and on healthy age-matched subjects. To obtain accurate dynamic characteristic values, a de-noising wavelet-based algorithm is first applied to LDF signals. All the de-noised signals are then normalised to the same value. The blood flow peak and the time to reach this peak are then calculated on each computed signal. The results show that a large vasodilation is present on signals of healthy subjects. The mean peak occurs at a pressure of 3.2 kPa approximately. However, a vasodilation of limited amplitude appears on type 1 diabetic patients. The maximum value is visualised, on the average, when the pressure is 1.1 kPa. The inability for diabetic patients to increase largely their cutaneous blood flow may bring explanations to foot ulcers.

  10. Effects of light sources and intensity on broilers grown to heavy weights. Part 1: Growth performance, carcass characteristics, and welfare indices.

    Science.gov (United States)

    Olanrewaju, H A; Miller, W W; Maslin, W R; Collier, S D; Purswell, J L; Branton, S L

    2016-04-01

    This study investigated the effects of light sources and light intensity on growth performance, carcass characteristics, and welfare indices of heavy broilers (>3.0 kg) in 4 trials with 2 replications per trial. A total of 960 one-day-old Ross×Ross 708 chicks (30 males/30 females/room) were randomly distributed into 16 environmentally controlled rooms at 50% RH. A 4×2 factorial treatment structure evaluated 4 light sources (incandescent [ICD, standard], compact fluorescent [CFL], neutral light emitting diode [Neutral-LED], and cool poultry specific filtered LED [Cool-PSF-LED]) and 2 levels (5 lx, 20 lx) of light intensities. Each of the 4 light sources was paired with one of the 2 light intensities. Birds were fed the same diet with a 4-phase feeding program (starter, grower, finisher, and withdrawal). Feed and water were provided ad libitum. Birds and feed were weighed on one, 14, 21, 28, 42, and 56 d of age for growth performance. All mortality was recorded daily and feed conversion was adjusted for mortality. Immune response was determined on d 28 to d 35, whereas other welfare indices were performed on d 42 and 49, respectively. At d 56 of each trial, 20 (10 males and 10 females) birds from each room were processed to determine weights and yields. The BW, BW gain, live weight, and carcass weights of birds reared under Cool-PSF-LED were different (P≤0.05) in comparison to birds reared under ICD. However, FI, FCR, and mortality were not affected by treatments. There was no effect of treatments on fat or breast and tender weights and yields. In addition, there was no effect of treatments on ocular development, immune response, and other welfare indices, suggesting that the light sources evaluated did not compromise welfare of heavy broilers. It was concluded that the 3 light sources evaluated in this study may be suitable for replacement of ICD light source in poultry facilities to reduce energy cost and optimize production efficiency.

  11. Monitoring the Progression of Renal Fibrosis by T2-weighted Signal Intensity and Diffusion Weighted Magnetic Resonance Imaging in Cisplatin induced Rat Models

    Institute of Scientific and Technical Information of China (English)

    Huan-Huan Wu; Hui-Ru Jia; Yi Zhang; Le Liu; Dong-Bo Xu; Hao-Ran Sun

    2015-01-01

    Background:Diffusion weighted imaging (DWI),with the applying of intravoxel incoherent motion model,has showed promising results in obtaining additional information about microperfusion and tubular flow associated with morphologic changes in chronic kidney diseases.The study aims to evaluate the potential of T2-weighted signal intensity (SI) and DWI with mono-and bi-exponential models to reflect the serial changes on cisplatin (CP) induced rat renal fibrosis models.Methods:Magnetic resonance exams were performed prior to and 2nd day,4th day,6th day,8th day,2nd week,3rd week and 4th week after CP injection at a 3.0T with an animal coil.Besides T2-weighted images (T2WI),DWI of 13 b values from 0 to 1500 s/mm2 was acquired.Apparent diffusion coefficient (ADC),fluid fraction f,pure diffusivity D and pseudodiffusivity D* values were calculated.The regions of interest were placed on cortex (CO),outer stripe of the outer medulla (OM) and inner stripe of the outer medulla (OM),parameters were measured and compared among different time points.Five rats were scarified at each time point for pathological examination.Results:OM revealed remarkable hyperintense and broadened before it became an obscure thread,while CO demonstrated moderate hyperintense and IM didn't show significant change on T2WI.On all three stripes,ADC values decreased firstly then kept increasing since the 4th day;f values decreased on all stripes; D values had a tendency to increase with fluctuations but the changes didn't achieve statistical significance; D* values increased at the 2nd day then tended to be steady thereafter.Pathological findings revealed tubules epitheliums swelling followed by inflammation cells infiltration,interstitial fibrosis was observed since the 2nd week.Conclusions:All of T2-weighted SI,ADC,and biexponential models parameters vary during fibrotic process; biexponential model is superior to monoexponential model in separating changes of microperfusion together with tubular flow

  12. Localization of rainfall and determination its intensity in the lower layers of the troposphere from the measurements of local RF transmitter characteristics

    Science.gov (United States)

    Podhorský, Dušan; Fabo, Peter

    2016-12-01

    The article deals with a method of acquiring the temporal and spatial distribution of local precipitation from measurement of performance characteristics of local sources of high frequency electromagnetic radiation in the 1-3GHz frequency range in the lower layers of the troposphere up to 100 m. The method was experimentally proven by monitoring the GSM G2 base stations of cell phone providers in the frequency range of 920-960MHz using methods of frequential and spatial diversity reception. Modification of the SART method for localization of precipitation was also proposed. The achieved results allow us to obtain the timeframe of the intensity of local precipitation in the observed area with a temporal resolution of 10 sec. A spatial accuracy of 100m in localization of precipitation is expected, after a network of receivers is built. The acquired data can be used as one of the inputs for meteorological forecasting models, in agriculture, hydrology as a supplementary method to ombrograph stations and measurements for the weather radar network, in transportation as part of a warning system and in many other areas.

  13. 含噪信号的特征基表示与信号去噪重构%Characteristic Base Representation of Noisy Signal and Reconstruction of Denoised Signal

    Institute of Scientific and Technical Information of China (English)

    孙亮; 陈梅莲

    2000-01-01

    A denoising reconstruction algorithm using the signal magnitude spectrum is proposed and the simulation studies have been performed. The magnitude-frequency characteristics of the noisy signal is utilized in the algorithm and the denoising is realized by the use of characteristic bases. The simulation results have shown that the wide-band noise can be largely cancelled using the algorithm proposed to perform the noisy signal reconstruction. The algorithm can be used for the off-line denoising of the strong noise corrupted signals.%提出了一种利用信号幅度谱的去噪重构算法,并作了仿真实验研究. 该算法利用含噪信号在幅频特性上的特征,通过特征基来进行信号的去噪处理. 仿真研究结果表明,采用该种算法作含噪信号的重构,可以明显地去除信号的宽带噪声. 该算法可以应用于噪声严重污染信号的离线去噪处理.

  14. Time evolution of the intensity correlation function in a single-mode laser driven by both the coloured pump noise with signal modulation and the quantum noise with cross-correlation between the real and imaginary parts

    Institute of Scientific and Technical Information of China (English)

    Cheng Qing-Hua; Cao Li; Xu Da-Hai; Wu Da-Jin

    2005-01-01

    Using the linear approximation, we have studied the time evolution of intensity correlation function C(t) in a single-mode laser driven by both the coloured pump noise with signal modulation and the quantum noise with crosscorrelation between its real and imaginary parts. In the case of the pump noise with self-correlation time τ 1, the time evolution of C(t) only exhibits a form of damping oscillation.

  15. Pediatric Brain: Repeated Exposure to Linear Gadolinium-based Contrast Material Is Associated with Increased Signal Intensity at Unenhanced T1-weighted MR Imaging.

    Science.gov (United States)

    Flood, Thomas F; Stence, Nicholas V; Maloney, John A; Mirsky, David M

    2017-01-01

    Purpose To determine whether repeated exposure of the pediatric brain to a linear gadolinium-based contrast agent (GBCA) is associated with an increase in signal intensity (SI) relative to that in GBCA-naive control subjects at unenhanced T1-weighted magnetic resonance (MR) imaging. Materials and Methods This single-center, retrospective study was approved by the institutional review board and compliant with HIPAA. The authors evaluated 46 pediatric patients who had undergone at least three GBCA-enhanced MR examinations (30 patients for two-group analysis and 16 for pre- and post-GBCA exposure comparisons) and 57 age-matched GBCA-naive control subjects. The SI in the globus pallidus, thalamus, dentate nucleus, and pons was measured at unenhanced T1-weighted MR imaging. Globus pallidus-thalamus and dentate nucleus-pons SI ratios were calculated and compared between groups and relative to total cumulative gadolinium dose, age, sex, and number of and mean time between GBCA-enhanced examinations. Analysis included the Wilcoxon signed rank test, Wilcoxon rank sum test, and Spearman correlation coefficient. Results Patients who underwent multiple GBCA-enhanced examinations had increased SI ratios within the dentate nucleus (mean SI ratio ± standard error of the mean for two-group comparison: 1.007 ± 0.0058 for GBCA-naive group and 1.046 ± 0.0060 for GBCA-exposed group [P mean SI ratio for pre- and post-GBCA comparison: 0.995 ± 0.0062 for pre-GBCA group and 1.035 ± 0.0063 for post-GBCA group [P mean SI ratio for two-group comparison: 1.131 ± 0.0070 for GBCA-naive group and 1.014 ± 0.0091 for GBCA-exposed group [P = .21]; mean SI ratio for pre- and post-GBCA comparison: 1.068 ± 0.0094 for pre-GBCA group and 1.093 ± 0.0134 for post-GBCA group [P = .12]). There was a significant correlation between dentate nucleus SI and total cumulative gadolinium dose (r = 0.4; 95% confidence interval [CI]: 0.03, 0.67; P = .03), but not between dentate nucleus SI and patient age

  16. Design and application of a drip-type rainfall simulator adapted to steep topography and low intensity-rainfall characteristics in the Coastal Range of Southern Chile

    Science.gov (United States)

    Mohr, Christian; Anton, Huber

    2010-05-01

    leakage of overland flow leading the runoff to a cemented trough. The experiments were conducted until a steady state infiltration rate was observed or the runoff ceased. The runoff samples are taken manually in intervals of 5 or 10 min depending on the simulated intensity and amount of runoff. All bottled samples were filtered to determine the sediment concentration. To test the system's effectiveness a pilot-study was conducted in a granitic soil catchment. The obtained values of the infiltration rate indicate that soil physical properties in this area facilitate rapid infiltration and slope did not show main influence. The sediment concentration showed high variability due to heterogeneity of surface and soil characteristics. In a succeeding study 36 rainfall simulations prior to clear-cuts during dry summer-season and rainy winter-season were carried out to determine the effect of both silvicultural practices on micro-scale. Soil hydrological response showed preferential flow patterns and variable infiltration-rates due to topsoil disturbance in the course of previous timber-harvests and differences in soil depth, hydrophobic organic layers and imbedded rocks. Maximum steady state infiltration rates ranged between 7.3 and 32.3 mm/h. In contrast to the expected results, maximum infiltration occurred at steep slopes. Only little sediment transport was measured. Only under high precipitation on steep slopes a moderate sediment transport (0.074 g/l) was documented. Post clear-cut infiltration experiments will be conducted in Jan.-March 2010. Furthermore, a modified tipping-bucket-device will be installed as a runoff collector-device to gain better temporal resolution.

  17. Quantum chemical calculations to reveal the relationship between the chemical structure and the fluorescence characteristics of phenylquinolinylethynes and phenylisoquinolinylethynes derivatives, and to predict their relative fluorescence intensity.

    Science.gov (United States)

    Riahi, Siavash; Beheshti, Abolghasem; Ganjali, Mohammad Reza; Norouzi, Parviz

    2009-12-01

    In this paper the relationship between the chemical structure and fluorescence characteristics of 30 phenylquinolinylethyne (PhQE), and phenylisoquinolinylethyne (PhIE) derivatives compounds employing ab initio calculations have been elucidated. Quantum chemical calculations (6-31G) were carried out to obtain: the optimized geometry, energy levels, charges and dipole moments of these compounds, in the singlet (steady and excited states) and triplet states. The relationship between quantum chemical descriptors, and wavelength of maximum excitation and emission indicated that these two parameters have the most correlation with quantum chemical hardness (eta). Also, stokes shift has the most correlation with the square of difference between the maximum of positive charges in the singlet steady and singlet excited states. The quantitative structure-property relationship (QSPR) of PhQE and PhIE was studied for relative fluorescence intensity (RFI). The genetic algorithm (GA) was applied to select the variables that resulted in the best-fit models. After the variable selection, multiple linear regression (MLR) and support vector machine (SVM) were both utilized to construct linear and non-linear QSPR models, respectively. The SVM model demonstrated a better performance than that of the MLR model. The route mean square error (RMSE) in the training and the test sets for the SVM model was 0.195 and 0.324, and the correlation coefficients were 0.965 and 0.960, respectively, thus revealing the reliability of this model. The resulting data indicated that SVM could be used as a powerful modeling tool for QSPR studies. According to the best of our knowledge, this is the first research on QSPR studies to predict RFI for a series of PhQE and PhIE derivative compounds using SVM.

  18. Non-thermal ablation of rabbit liver VX2 tumor by pulsed high intensity focused ultrasound with ultrasound contrast agent: Pathological characteristics

    Institute of Scientific and Technical Information of China (English)

    Cheng-Wen Zhou; Fa-Qi Li; Yan Qin; Chun-Mei Liu; Xiao-Lin Zheng; Zhi-Biao Wang

    2008-01-01

    AIM:To investigate the pathological characteristics of non-thermal damage induced by pulsed high intensity focused ultrasound (PHIFU) combined with ultrasound contrast agent (UCA),SonoVue (Bracco SpA,Milan,Italy) in rabbit liver VX2 tumor.METHODS:Liver VX2 tumor models were established in 20 rabbits,which were divided randomly into PHIFU combined with ultrasound contrast agent group (PHIFU + UCA group) and sham group.In the PHIFU + UCA group,0.2 mL of SonoVue was injected intravenously into the tumor,followed by ultrasound exposure of Isp 5900 W/cm2.The rabbits were sacrificed one day after ultrasound exposure.Specimens of the exposed tumor tissues were obtained and observed pathologically under light microscope and transmission electron microscope.The remaining tumor tissues were sent for 2,3,5-Triphenyltetrazolium chloride (TTC) staining.RESULTS:Before TTC staining,tumor tissues in both the sham and the PHIFU + UCA groups resembled gray fish meat.After TTC staining,the tumor tissues were uniformly stained red,with a clear boundary between tumor tissue and normal tissue.Histological examination showed signs of tumor cell injury in PHIFU + UCA group,with cytoplasmic vacuoles of various sizes,chromatin margination and karyopyknosis.Electron microscopic examination revealed tumor cell volume reduction,karyopyknosis,chromatin margination,intercellular space widening,the presence of high electron-density apoptotic bodies and vacuoles in cytoplasm.CONCLUSION:The non-thermal effects of PHIFU combined with UCA can be used to ablate rabbit liver VX2 tumors.

  19. Use of Self-Matching to Control for Stable Patient Characteristics While Addressing Time-Varying Confounding on Treatment Effect: A Case Study of Older Intensive Care Patients.

    Science.gov (United States)

    Han, Ling; Pisani, M A; Araujo, K L B; Allore, Heather G

    Exposure-crossover design offers a non-experimental option to control for stable baseline confounding through self-matching while examining causal effect of an exposure on an acute outcome. This study extends this approach to longitudinal data with repeated measures of exposure and outcome using data from a cohort of 340 older medical patients in an intensive care unit (ICU). The analytic sample included 92 patients who received ≥1 dose of haloperidol, an antipsychotic medication often used for patients with delirium. Exposure-crossover design was implemented by sampling the 3-day time segments prior (Induction) and posterior (Subsequent) to each treatment episode of receiving haloperidol. In the full cohort, there was a trend of increasing delirium severity scores (Mean±SD: 4.4±1.7) over the course of the ICU stay. After exposure-crossover sampling, the delirium severity score decreased from the Induction (4.9) to the Subsequent (4.1) intervals, with the treatment episode falling in-between (4.5). Based on a GEE Poisson model accounting for self-matching and within-subject correlation, the unadjusted mean delirium severity scores was -0.55 (95% CI: -1.10, -0.01) points lower for the Subsequent than the Induction intervals. The association diminished by 32% (-0.38, 95%CI: -0.99, 0.24) after adjusting only for ICU confounding, while being slightly increased by 7% (-0.60, 95%CI: -1.15, -0.04) when adjusting only for baseline characteristics. These results suggest that longitudinal exposure-crossover design is feasible and capable of partially removing stable baseline confounding through self-matching. Loss of power due to eliminating treatment-irrelevant person-time and uncertainty around allocating person-time to comparison intervals remain methodological challenges.

  20. Changes of the morphological characteristics in a professional ice hockey player with regard to the eight week intensive fitness training: case study

    Directory of Open Access Journals (Sweden)

    Sigmund Martin

    2013-01-01

    Full Text Available The present study deals with monitoring the changes of the morphological characteristics in a professional hockey player (NHL aged 22.5 years with regard to the eight weeks intensive fitness training. Fitness training occurred off the ice surface. To determine the body composition, the method of BIA and anthropometric procedure is used (Matiegka, Pařízková. Measurements were carried out in accordance with the recommended national and international standards. An effect size of the differences in the selected individual values measured at different times was assessed using 95% of confidence interval. Significant changes occur primarily at the level of body composition. Overall, the increase in fat free mass was 4 kg to the weight 79.3 kg (BIA. Representation of muscle increased from 51.4% to 54.5% (Matiegka. In absolute terms it is the increase in muscle from 47.1 kg to 49.9 kg. Body fat percentage decreased from 12.9% to 9.7% (Matiegka. This represents a reduction of 2.9 kg. There is no change at the level of skeletal and residual fractions. With regard to the eight week fitness training the major morhpohogical changes (80-90% are experienced during the first half of the training (4 weeks. The survey results are of immediate use in the professional practice of the monitored player. It allows specific modifications to the training of the monitored player as well as other cooperating individuals in the chosen specialization.

  1. A Prospective, Descriptive Study to Determine the Rate and Characteristics of and Risk Factors for the Development of Medical Device-related Pressure Ulcers in Intensive Care Units.

    Science.gov (United States)

    Hanonu, Seval; Karadag, Ayise

    2016-02-01

    Pressure ulcers do not develop only in areas with bony prominences; they can develop in any tissue under pressure, including pressure exerted by medical devices. A prospective, descriptive study was conducted from December 15, 2013 to March 25, 2014 to determine the prevalence, risk factors, and characteristics of medical device-related hospitalacquired pressure ulcers (MDR HAPUs) among all patients (N = 175) in 5 adult intensive care units (ICUs) in a university hospital in Turkey. The previously established point prevalence of hospital-acquired pressure ulcers (HAPUs) in these ICUs was 15%. Patients were evaluated in the first 24 hours after admission and observed 6 times thereafter in intervals of 48 hours. Demographic (eg, age, gender, body mass index) and medical device-related pressure ulcer data (eg, location, device type, stage), and Braden Scale scores were collected and analyzed; frequencies and percentages were calculated and Mann-Whitney U Test, t-test, and odds ratios were applied. Twenty-seven (27) patients (15.4%) developed nonMDR HAPUs and 70 (40.0%) developed MDR HAPUs. MDR HAPUs occurred most frequently (45.0%) in patients with an endotracheal tube. The most frequent type (42.6%) was Stage II. The highest rates of MDR HAPUs were observed among internal medicine ICU patients (OR 7.041), patients who also had a nonMDR HAPU (OR 6.6), patients in the high Braden risk score group (OR 1.8), or patients who received enteral feeding (OR 2.12). Because of the high rate of MDR HAPUs noted, policies and procedures aimed at preventing medical device-related pressure ulcers are needed.

  2. Characterization of solar cells for space applications. Volume 11: Electrical characteristics of 2 ohm-cm, 228 micron wraparound solar cells as a function of intensity, temperature, and irradiation. [for solar electric propulsion

    Science.gov (United States)

    Anspaugh, B. E.; Beckert, D. M.; Downing, R. G.; Weiss, R. S.

    1980-01-01

    Parametric characterization data on Spectrolab 2 by 4 cm, 2 ohm/cm, 228 micron thick wraparound cell, a candidate for the Solar Electric Propulsion Mission, are presented. These data consist of the electrical characteristics of the solar cell under a wide range of temperature and illumination intensity combinations of the type encountered in space applications.

  3. Relationship between fluid-attenuated inversion-recovery (FLAIR) signal intensity and inflammatory mediator's levels in the hippocampus of patients with temporal lobe epilepsy and mesial temporal sclerosis.

    Science.gov (United States)

    Varella, Pedro Paulo Vasconcellos; Santiago, Joselita Ferreira Carvalho; Carrete, Henrique; Higa, Elisa Mieko Suemitsu; Yacubian, Elza Márcia Targas; Centeno, Ricardo Silva; Caboclo, Luís Otávio Sales Ferreira; Castro Neto, Eduardo Ferreira de; Canzian, Mauro; Amado, Débora; Cavalheiro, Esper Abrão; Naffah-Mazzacoratti, Maria da Graça

    2011-02-01

    We investigated a relationship between the FLAIR signal found in mesial temporal sclerosis (MTS) and inflammation. Twenty nine patients were selected through clinical and MRI analysis and submitted to cortico-amygdalo-hippocampectomy to seizure control. Glutamate, TNFα, IL1, nitric oxide (NO) levels and immunostaining against IL1β and CD45 was performed. Control tissues (n=10) were obtained after autopsy of patients without neurological disorders. The glutamate was decreased in the temporal lobe epilepsy (TLE) -MTS group (p<0.001), suggesting increased release of this neurotransmitter. The IL1β and TNFα were increased in the hippocampus (p<0.05) demonstrating an active inflammatory process. A positive linear correlation between FLAIR signal and NO and IL1β levels and a negative linear correlation between FLAIR signal and glutamate concentration was found. Lymphocytes infiltrates were present in hippocampi of TLE patients. These data showed an association between hippocampal signal alteration and increased inflammatory markers in TLE-MTS.

  4. Targeted Elimination of G Proteins and Arrestins Defines Their Specific Contributions to Both Intensity and Duration of G Protein-coupled Receptor Signaling.

    Science.gov (United States)

    Alvarez-Curto, Elisa; Inoue, Asuka; Jenkins, Laura; Raihan, Sheikh Zahir; Prihandoko, Rudi; Tobin, Andrew B; Milligan, Graeme

    2016-12-30

    G protein-coupled receptors (GPCRs) can initiate intracellular signaling cascades by coupling to an array of heterotrimeric G proteins and arrestin adaptor proteins. Understanding the contribution of each of these coupling options to GPCR signaling has been hampered by a paucity of tools to selectively perturb receptor function. Here we employ CRISPR/Cas9 genome editing to eliminate selected G proteins (Gαq and Gα11) or arrestin2 and arrestin3 from HEK293 cells together with the elimination of receptor phosphorylation sites to define the relative contribution of G proteins, arrestins, and receptor phosphorylation to the signaling outcomes of the free fatty acid receptor 4 (FFA4). A lack of FFA4-mediated elevation of intracellular Ca(2+) in Gαq/Gα11-null cells and agonist-mediated receptor internalization in arrestin2/3-null cells confirmed previously reported canonical signaling features of this receptor, thereby validating the genome-edited HEK293 cells. FFA4-mediated ERK1/2 activation was totally dependent on Gq/11 but intriguingly was substantially enhanced for FFA4 receptors lacking sites of regulated phosphorylation. This was not due to a simple lack of desensitization of Gq/11 signaling because the Gq/11-dependent calcium response was desensitized by both receptor phosphorylation and arrestin-dependent mechanisms, whereas a substantially enhanced ERK1/2 response was only observed for receptors lacking phosphorylation sites and not in arrestin2/3-null cells. In conclusion, we validate CRISPR/Cas9 engineered HEK293 cells lacking Gq/11 or arrestin2/3 as systems for GPCR signaling research and employ these cells to reveal a previously unappreciated interplay of signaling pathways where receptor phosphorylation can impact on ERK1/2 signaling through a mechanism that is likely independent of arrestins.

  5. Reconfigurable intensity modulation and direct detection optical transceivers for variable-rate wavelength-division-multiplexing passive optical networks utilizing digital signal processing-based symbol mapper

    Science.gov (United States)

    Zhang, Zhiguo; Zhang, Bingbing; Chen, Yanxu; Chen, Xue

    2017-01-01

    Variable-rate intensity modulation and direct detection-based optical transceivers with software-controllable reconfigurability and transmission performance adaptability are experimentally demonstrated, utilizing M-QAM symbol mapping implemented in MATLAB® programs. A frequency division multiplexing-based symbol demapping and wavelength management method is proposed for the symbol demapper and tunable laser management used in colorless optical network unit.

  6. Characteristics of receptor- and transducer-coupled activation of the intracellular signalling in sensory neuron revealed by atomic force microscopy

    Science.gov (United States)

    Khalisov, M. M.; Penniyaynen, V. A.; Esikova, N. A.; Ankudinov, A. V.; Krylov, B. V.

    2017-01-01

    The mechanical properties of sensory neurons upon activation of intracellular cascade processes by comenic acid binding to a membrane opioid-like receptor (receptor-coupled), as well as a very low (endogenous) concentration of ouabain (transducer-coupled), have been investigated. Using atomic force microscopy, it is established that exposure to ouabain, in contrast to the impact of comenic acid, leads to a hardening of the neuron soma. This suggests that the receptor-coupled signal transmission to the cell genome is carried out through mechanisms that are different from the transducer-coupled signal pathways.

  7. An algorithm for real-time dosimetry in intensity-modulated radiation therapy using the radioluminescence signal from Al2O3:C

    DEFF Research Database (Denmark)

    Andersen, C.E.; Marckmann, C.J.; Aznar, Marianne

    2006-01-01

    Although the radioluminescence (RL) signal from optical fibre Al2O3:C dosemeters used in medical applications is essentially proportional to dose rate, the crystals used so far are imperfect in the sense that their RL sensitivity changes with accumulated dose. A computational algorithm has been...... to the treatment planning system. RL signals from Al2O3:C can be used for real-time dose rate measurements with a time resolution of similar to 0.1 s and a spatial resolution only limited by the size of the detector (

  8. Cuffless Blood Pressure Estimation with Photoplethysmograph Signal by Classifying on Account of Cardiovascular Characteristics of Old Aged Patients

    Science.gov (United States)

    Suzuki, Satomi; Oguri, Koji

    Blood Pressure (BP) is a very important factor for monitoring the cardiovascular condition. In general, non-invasive BP measurements need a cuff. However, such measurement techniques can hardly monitor BP continuously. Recently it has gotten easier to measure biological signals daily because sensor technologies have well-developed, and because of availability of many kinds of miniaturized measurement instruments consuming less power. This study suggests a method of estimating Systolic Blood Pressure (SBP) with a wearable sensor instead of a cuff. In particular, our study depends on only one pulse wave signal detected by a Photoplethysmograph (PPG) sensor since the PPG sensor is very small. Moreover, the human subject just wears the sensor on the surface of the body to measure the signal. Cardiovascular peculiarities keep changing as people get older. Additionally, the peculiarities vary among individuals according to the advanced rate of arteriosclerosis. Hence, it is necessary for estimating the SBP to divide the data into several classes, by parameters that relate to individual cardiovascular peculiarities. In this study, the regression equation of SBP was calculated from individual information and from features of the PPG signal in each class. As a result, the estimation accuracy was improved. This technique would make cuffless SBP monitoring become more convenient and helpful as only one device is required for monitoring, which is smaller than traditional measurements.

  9. Scaled signal intensity of uterine fibroids based on T2-weighted MR images: a potential objective method to determine the suitability for magnetic resonance-guided focused ultrasound surgery of uterine fibroids

    Energy Technology Data Exchange (ETDEWEB)

    Park, Hyun [CHA University, Comprehensive Gynecologic Cancer Center, CHA Bundang Medical Center, Gyunggi-do (Korea, Republic of); Yoon, Sang-Wook [CHA University, Department of Diagnostic Radiology, CHA Bundang Medical Center, Sungnam-si, Gyunggi-do (Korea, Republic of); Sokolov, Amit [InSightec Ltd., Haifa (Israel)

    2015-12-15

    Magnetic Resonance-guided Focused Ultrasound Surgery (MRgFUS) is a non-invasive method to treat uterine fibroids. To help determine the patient suitability for MRgFUS, we propose a new objective measure: the scaled signal intensity (SSI) of uterine fibroids in T2 weighted MR images (T2WI). Forty three uterine fibroids in 40 premenopausal women were included in this retrospective study. SSI of each fibroid was measured from the screening T2WI by standardizing its mean signal intensity to a 0-100 scale, using reference intensities of rectus abdominis muscle (0) and subcutaneous fat (100). Correlation between the SSI and the non-perfused volume (NPV) ratio (a measure for treatment success) was calculated. Pre-treatment SSI showed a significant inverse-correlation with post treatment NPV ratio (p < 0.05). When dichotomizing NPV ratio at 45 %, the optimal cut off value of the SSI was found to be 16.0. A fibroid with SSI value 16.0 or less can be expected to have optimal responses. The SSI of uterine fibroids in T2WI can be suggested as an objective parameter to help in patient selection for MRgFUS. (orig.)

  10. Dating loess with high temperature IRSL signals from polymineral fine grains: luminescence characteristics and comparison with conventional techniques

    Science.gov (United States)

    Thiel, C.; Buylaert, J.-P.; Murray, A. S.; Tsukamoto, S.; Jain, M.; Frechen, M.

    2009-04-01

    It is well known that loess deposits contain detailed terrestrial archives of palaeoenvironmental changes. Unfortunately, loess sequences often lack a reliable absolute chronology, and thus these changes are difficult to constrain in time. Luminescence dating is the technique of choice to address this issue. Quartz and feldspar are the most commonly used dosimeters in luminescence dating. The age range of standard quartz OSL is usually limited by the saturation level of ~200 Gy (corresponding to ~50 ka). In contrast, the age range of feldspar IRSL signals - which usually have a more extended growth curve (up to ~2000 Gy) - is hampered by anomalous fading for which a reliable correction is still not available. Recently, Thomsen et al. (2008) identified several laboratory-induced feldspar signals which show less anomalous fading than the standard IRSL signal stimulated at 50°C. Based on this work, Buylaert et al. (accepted) tested a post-IR IR signal, i.e. IR bleach at 50°C and subsequent IRSL measurement at 225°C, and observed significantly lower fading rates in nature for a number of coarse-grained K-feldspar samples. In this study we explore the possibility of using such a post-IR IR signal from polymineral fine grains extracted from loess. Murray et al. (accepted) showed that a more stringent preheat treatment (320°C for 60 s) can be safely used for feldspar; as a result, we have been able to use a post-IR IR measurement temperature of 290°C, higher than that in the study of Buylaert et al. (accepted), with the expectation that this might further reduce the observed fading rate. The results of the elevated temperature IRSL signal fading measurements clearly indicate a significantly lower fading rate (g2days values typically 1-1.5 %/decade) than the standard IRSL measured at 50°C (g2days values typically 3 %/decade). Results of the performance in the SAR protocol (recycling ratios, recuperation and dose recovery) are very encouraging (measured dose within 15

  11. CTLA-4 signaling regulates the intensity of hypersensitivity responses to food antigens, but is not decisive in the induction of sensitization

    NARCIS (Netherlands)

    Wijk, F. van; Hoeks, S.; Nierkens, S.; Koppelman, S.J.; Kooten, P. van; Boon, L.; Knippels, L.M.J.; Pieters, R.

    2005-01-01

    Although food allergy has emerged as a major health problem, the mechanisms that are decisive in the development of sensitization to dietary Ag remain largely unknown. CTLA-4 signaling negatively regulates immune activation, and may play a crucial role in preventing induction and/or progression of s

  12. Relationship between fluid-attenuated inversion-recovery (FLAIR signal intensity and inflammatory mediator's levels in the hippocampus of patients with temporal lobe epilepsy and mesial temporal sclerosis

    Directory of Open Access Journals (Sweden)

    Pedro Paulo Vasconcellos Varella

    2011-02-01

    Full Text Available We investigated a relationship between the FLAIR signal found in mesial temporal sclerosis (MTS and inflammation. Twenty nine patients were selected through clinical and MRI analysis and submitted to cortico-amygdalo-hippocampectomy to seizure control. Glutamate, TNFα, IL1, nitric oxide (NO levels and immunostaining against IL1β and CD45 was performed. Control tissues (n=10 were obtained after autopsy of patients without neurological disorders. The glutamate was decreased in the temporal lobe epilepsy (TLE -MTS group (p<0.001, suggesting increased release of this neurotransmitter. The IL1β and TNFα were increased in the hippocampus (p<0.05 demonstrating an active inflammatory process. A positive linear correlation between FLAIR signal and NO and IL1β levels and a negative linear correlation between FLAIR signal and glutamate concentration was found. Lymphocytes infiltrates were present in hippocampi of TLE patients. These data showed an association between hippocampal signal alteration and increased inflammatory markers in TLE-MTS.

  13. Signal-Characteristic analysis with respect to backing material of PVDF-based high-frequency ultrasound for photoacoustic microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jun Su; Chang, Jin Ho [Dept. of Electronic Engineering, Sogang University, Seoul (Korea, Republic of)

    2015-04-15

    Photoacoustic microscopy is capable of providing high-resolution molecular images, and its spatial resolution is typically determined by ultrasonic transducers used to receive the photoacoustic signals. Therefore, ultrasonic transducers for photoacoustic microscopy (PAM) should have a high operating frequency, broad bandwidth, and high signal-reception efficiency. Polyvinylidene fluoride (PVDF) is a suitable material. To take full advantage of this material, the selection of the backing material is crucial, as it influences the center frequency and bandwidth of the transducer. Therefore, we experimentally determined the most suitable backing material among EPO-TEK 301, E-Solder 3022, and RTV. For this, three PVDF high-frequency single-element transducers were fabricated with each backing material. The center frequency and -6 dB bandwidth of each transducer were ascertained by a pulse-echo test. The spatial resolution of each transducer was examined using wire-target images. The experimental results indicated that EPO-TEK 301 is the most suitable backing material for a PAM transducer. This material provides the highest signal magnitude and a reasonable bandwidth because a large portion of the energy propagates toward the front medium, and the PVDF resonates in the half-wave mode.

  14. Correlation of signal intensity ratio on orbital MRI-TIRM and clinical activity score as a possible predictor of therapy response in Graves' orbitopathy - a pilot study at 1.5 T

    Energy Technology Data Exchange (ETDEWEB)

    Kirsch, Eberhard C.; Kaim, Achim H. [Hirslanden Clinic Aarau, Neuroradiology and Cranio-Facial-Center Hirslanden, Aarau (Switzerland); Oliveira, Marion Gregorio de [University Eye Clinic Basel, Basel (Switzerland); Arx, Georg von [basedow.ch, Interdiscipinary Centre for Graves' Orbitopathy, Olten (Switzerland)

    2010-02-15

    This study seeks to describe the predictive value of the signal intensity ratio (SIR) in magnetic resonance imaging-turbo inversion recovery magnitude (MRI-TIRM) in patients with Graves' orbitopathy (GO) with regard to predictability of therapy response. Included in this prospective pilot study were 36 consecutive patients with GO and 25 control subjects. Patients were clinically assessed according to the European Group on Graves' Orbitopathy recommendations with active GO defined by a clinical activity score (CAS) {>=} 3. On magnetic resonance (MR) imaging, muscle inflammation was measured with a region of interest set within the brightest extra-ocular muscle both on coronal turbo inversion recovery magnitude (TIRM) and on fat suppressed gadolinium-enhanced T1-weighted sequences. To calculate the SIR, the measured signal intensity was set in proportion to that of the ipsilateral temporalis muscle. Signal intensity ratio in coronal T2-weighted TIRM sequences in either group ranged from 1.22 to 4.92 (mean 2.04) in patients with GO and from 1.18 to 2.4 (mean 1.63) in controls without GO. The observed differences were significant on the TIRM sequences (right eye p = 0.023; left eye p = 0.022), whereas, no significant differences could be detected on the T1-weighted sequences (right eye p = 0.396; left eye p = 0.498). A cut off value of SIR > 2.5 for a CAS {>=} 4 to discriminate active from inactive patients was statistically calculated. T2 relaxation time is a reliable tool in detecting active GO. The difference in T2-SIR versus T1-SIR is helpful to distinguish inflammatory oedema of the extra ocular muscles from intra-orbital congestion due to reduced venous outflow. (orig.)

  15. Method for diagnostics of characteristic patterns of observable time series and its real-time experimental implementation for neurophysiological signals

    NARCIS (Netherlands)

    Ovchinnikov, A.; Hramov, A.E.; Luttjohann, A.K.; Koronovskii, A.A.; Luijtelaar, E.L.J.M. van

    2011-01-01

    A method is proposed for analysis and automatic diagnostics of characteristic oscillatory patterns of the electric activity of the brain in real time on the basis of a continuous wavelet transformation. The results of experimental investigation of automatic recognition of epileptic activity episodes

  16. Reduction but not disappearance of Doppler signal after two years of treatment for gout. Do we need a more intensive treatment?

    Science.gov (United States)

    Peiteado, Diana; Villalba, Alejandro; Martín-Mola, Emilio; de Miguel, Eugenio

    2015-01-01

    We undertook this study to evaluate the responsiveness of Doppler ultrasound (US) to urate lowering therapy (ULT) in gout patients. Twenty-four consecutive patients were prospectively included from an outpatient clinic. The patients underwent clinical, and US assessment at baseline and after 6, 12 and 24 months of ULT. The US assessment was made by another rheumatologist blinded to the clinical data. Standardised examinations were performed in four joints (both first metatarso-phalangeals and knees) and the patellar tendons. The Doppler signals were scored. The mean and standard deviation were calculated for each parameter. The comparison between the quantitative values was performed by Student's t-test. Sensitivity to change in the US examinations was assessed by estimating the smallest detectable difference (SDD) in the total Doppler score. A Doppler signal was detected in 95.8% of the patients at the baseline. A significant parallel improvement in the serum urate level, clinical parameters and in Doppler scores was found at the follow-up assessment. 62% of the patients had achieved a uric concentration level below 6 mg/dl at one year. At two years, persistence of a Doppler signal was found in 72.7% of the patients. The SDD in the Doppler score at 2 years was 1.92, lower than the difference achieved. The Doppler US findings show significant improvement and responsiveness after ULT in gout patients. The Doppler signal persistence after two years of treatment is marked. This finding introduces a reflection on the accuracy of the current outcome measures and treatments.

  17. Small signal modulation characteristics of red-emitting (λ = 610 nm) III-nitride nanowire array lasers on (001) silicon

    KAUST Repository

    Jahangir, Shafat

    2015-02-16

    The small signal modulation characteristics of an InGaN/GaN nanowire array edge- emitting laser on (001) silicon are reported. The emission wavelength is 610 nm. Lattice matched InAlN cladding layers were incorporated in the laser heterostructure for better mode confinement. The suitability of the nanowire lasers for use in plastic fiber communication systems with direct modulation is demonstrated through their modulation bandwidth of f-3dB,max = 3.1 GHz, very low values of chirp (0.8 Å) and α-parameter, and large differential gain (3.1 × 10-17 cm2).

  18. On Characteristics and Countermeasures on Economy Crimes of Intensive Funds%资金密集型经济犯罪的特点与防控对策

    Institute of Scientific and Technical Information of China (English)

    任怡

    2013-01-01

    Economy crime of intensive funds is a kind of crime where many funds are involved in the criminal ac-tivities; cash deal is difficult to conduct; and funds exchange is frequent. It includes illegal raising capital crime, pyramid selling crime, security crime, illegal management crime of underground banks, crime of falsely opening the invoice of added value tax, and POS cash crimes. Its characteristics are as follows: tight organization, profes-sional, accounts involving crimes, huge amount of money, frequent funds flow, regular flow, strong invisible crimi-nal feature, and being not easy to be find. We should enhance crime publicity and promote the prevent con-sciousness of people, build up the defending and early-warning system, promote the active investigation ability, build up funds bargain model, optimize the tactics of economic investigation, establish the communication system, improve the regional cooperation of investigation, and promote the efficiency of l investigation and the level of striking economic crimes.%资金密集型经济犯罪是指犯罪活动中涉及资金量较大,难以实行现金交易,资金交易频繁的一类犯罪,其类型有非法集资犯罪、传销犯罪、证券领域犯罪、地下钱庄类非法经营犯罪、虚开增值税专用发票犯罪和POS机套现犯罪。此类犯罪具有犯罪组织严密、职业化趋势显现、犯罪涉及账户众多、涉案金额巨大、资金交易频繁密集、流向具有规律性,犯罪隐蔽性强,不易发现等特点。应从强化犯罪宣传、提升群众主动防范意识,建立防控预警体系,提升主动侦查能力,建立资金交易模型,优化经侦战法战术,建立沟通交流机制,促进区域侦查协作等方面提升行政机关对此类犯罪的整体防控能力,提升公安机关办理此类案件的侦查效率和打击经济犯罪的整体水平。

  19. Comparison of 5-hydroxytryptophan signaling pathway characteristics in diarrhea-predominant irritable bowel syndrome and ulcerative colitis.

    Science.gov (United States)

    Yu, Feng-Yan; Huang, Shao-Gang; Zhang, Hai-Yan; Ye, Hua; Chi, Hong-Gang; Zou, Ying; Lv, Ru-Xi; Zheng, Xue-Bao

    2016-03-28

    To study differences in the visceral sensitivity of the colonic mucosa between patients with diarrhea-predominant irritable bowel syndrome (IBS-D) and those with ulcerative colitis (UC) in remission and to relate these differences with changes in the 5-hydroxytryptophan (5-HT) signaling pathway. Gastrointestinal symptoms were used to determine the clinical symptom scores and rectal visceral sensitivity of patients with IBS-D and patients with UC in remission. Blood levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) were measured using an HPLC-electrochemical detection system. The levels of 5-HT 3 receptor (3R), 4R, and 7R mRNAs in colonic biopsy samples were detected using reverse transcription-polymerase chain reaction. The protein expression of TPH1 was analyzed by Western blot and immunohistochemistry. Abdominal pain or discomfort, stool frequency, and the scores of these symptoms in combination with gastrointestinal symptoms were higher in the IBS-D and UC groups than in the control groups. However, no significant differences were observed between the IBS-D and UC remission groups. With respect to rectal visceral sensitivity, the UC remission and IBS-D groups showed a decrease in the initial perception threshold, defecating threshold and pain threshold. However, these groups exhibited significantly increased anorectal relaxation pressure. Tests examining the main indicators of the 5-HT signaling pathway showed that the plasma 5-HT levels, 5-HIAA concentrations, TPH1 expression in the colonic mucosa, and 5-HT3R and 5-HT5R expression were increased in both the IBS-D and the UC remission groups; no increases were observed with respect to 5-HT7R expression. The IBS-D and UC groups showed similar clinical symptom scores, visceral sensitivity, and levels of serotonin signaling pathway indicators in the plasma and colonic mucosa. However, the pain threshold and 5-HT7R expression in the colonic mucosa were significantly different between these groups. The results

  20. Comparison of 5-hydroxytryptophan signaling pathway characteristics in diarrhea-predominant irritable bowel syndrome and ulcerative colitis

    Science.gov (United States)

    Yu, Feng-Yan; Huang, Shao-Gang; Zhang, Hai-Yan; Ye, Hua; Chi, Hong-Gang; Zou, Ying; Lv, Ru-Xi; Zheng, Xue-Bao

    2016-01-01

    AIM: To study differences in the visceral sensitivity of the colonic mucosa between patients with diarrhea-predominant irritable bowel syndrome (IBS-D) and those with ulcerative colitis (UC) in remission and to relate these differences with changes in the 5-hydroxytryptophan (5-HT) signaling pathway. METHODS: Gastrointestinal symptoms were used to determine the clinical symptom scores and rectal visceral sensitivity of patients with IBS-D and patients with UC in remission. Blood levels of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) were measured using an HPLC-electrochemical detection system. The levels of 5-HT 3 receptor (3R), 4R, and 7R mRNAs in colonic biopsy samples were detected using reverse transcription-polymerase chain reaction. The protein expression of TPH1 was analyzed by Western blot and immunohistochemistry. RESULTS: Abdominal pain or discomfort, stool frequency, and the scores of these symptoms in combination with gastrointestinal symptoms were higher in the IBS-D and UC groups than in the control groups. However, no significant differences were observed between the IBS-D and UC remission groups. With respect to rectal visceral sensitivity, the UC remission and IBS-D groups showed a decrease in the initial perception threshold, defecating threshold and pain threshold. However, these groups exhibited significantly increased anorectal relaxation pressure. Tests examining the main indicators of the 5-HT signaling pathway showed that the plasma 5-HT levels, 5-HIAA concentrations, TPH1 expression in the colonic mucosa, and 5-HT3R and 5-HT5R expression were increased in both the IBS-D and the UC remission groups; no increases were observed with respect to 5-HT7R expression. CONCLUSION: The IBS-D and UC groups showed similar clinical symptom scores, visceral sensitivity, and levels of serotonin signaling pathway indicators in the plasma and colonic mucosa. However, the pain threshold and 5-HT7R expression in the colonic mucosa were significantly different

  1. 花岗岩单轴受压条件下声发射信号频率特征试验研究%EXPERIMENTAL RESEARCH ON FREQUENCY CHARACTERISTICS OF ACOUSTIC EMISSION SIGNALS UNDER UNIAXIAL COMPRESSION OF GRANITE

    Institute of Scientific and Technical Information of China (English)

    纪洪广; 王宏伟; 曹善忠; 侯昭飞; 金延

    2012-01-01

    It is significant for us to do some research on AE signal frequency characteristics at different stages in the fracture process in order to select proper AE sensors with corresponding resonant frequencies. Through uniaxial compression test of granite, the result is shown that in the entire compression process, the rock experienced three stages; the ring count presented periodical changing regulation accompanying with the increasing of relative stress, and also the dominant frequencies of AE signals mainly took place at the plastic breaking stage of pre-mainfracture and mainfracture stage, focusing on 41 - 85 kHz. When relative stress is low, low-frequency signals of granite dominate; With the increasing of relative stress, the low-frequency and high-frequency signals of granite become intensive of which the amplitudes are relatively huge as well. Accordingly, sudden increasing of high-frequency and high-amplitude AE signal predicts potential peril of breaking of granite.%研究分析破裂过程不同阶段的声发射信号频率特性,对于选出相应谐振频率的声发射传感器具有重要意义.通过单轴压缩试验,结果表明:花岗岩受压过程中主要经历3个受力阶段,声发射振铃计数率随相对应力的增加呈现出阶段性的变化规律,声发射信号优势频率主要发生在岩石破裂前塑性破坏和主破裂阶段,且集中在41~85kHz.在相对应力较低时,花岗岩声发射信号频率以低频为主,随着相对应力的增加,其高频、低频信号密集且幅值很大,因此高频高幅值声发射信号的突然增多预示花岗岩有破坏危险.

  2. [Job satisfaction, job burnout and their relationships with work'and patients' characteristics: a comparison between intensive care units (ICU) and not-intensive care units (not-ICU)].

    Science.gov (United States)

    Viotti, Sara; Converso, Daniela; Loera, Barbara

    2012-01-01

    Health worker's population is espoused to high level of stress, and several studies highlight differences between intensive care units (ICU) and non-intensive care unit (non-ICU). Particular features of the job in ICU concern responsibilities for critically patients, highly advanced technology and need for quick decision. Aims of this study are: (1) to examine differences between ICU's and not-ICU's workers on several dimensions describing work environment and workers' health; (2) investigate which specific work conditions have a role in determining psychological work reactions in ICU's and not-ICU's workers. 144 ICUs' and not-ICU's 114 workers employed in an Italian Hospital filled out a questionnaire concerning decision authority, autonomy, colleagues' and supervisors' support, physical and cognitive demands as antecedents; job satisfaction and job burnout (EE, DP) as consequences. 1) MANOVA highlighted how ICU workers reported significantly higher scores on depersonalization, job satisfaction, aggressive customers, while physical demands and proportionate customer expectations were significantly higher for not-ICU workers; (2) Six Multiple Linear Regressions were carried out. Those indicated decision authority, autonomy and supervisors' support as predictors of emotional exhaustions in ICU. In not-ICU only cognitive demands and colleagues' support are significant predictors. Depersonalization is predicted in ICU by colleagues' support. Predictors of job satisfaction both in ICU and not-ICU are: decision authority and colleagues support. Current study highlighted several differences among ICU and non-ICU workers' referred to work environment and psychological reactions.

  3. Downregulation of the Canonical WNT Signaling Pathway by TGFβ1 Inhibits Photoreceptor Differentiation of Adult Human Müller Glia with Stem Cell Characteristics

    Science.gov (United States)

    Angbohang, Angshumonik; Wu, Na; Charalambous, Thalis; Eastlake, Karen; Lei, Yuan; Kim, Yung Su; Sun, Xinghuai H.

    2016-01-01

    Müller glia are responsible for the retina regeneration observed in zebrafish. Although the human retina harbors Müller glia with stem cell characteristics, there is no evidence that they regenerate the retina after disease or injury. Transforming growth factor-β (TGFβ) and Wnt signaling regulate retinal neurogenesis and inflammation, but their roles in the neural differentiation of human Müller stem cells (hMSC) are not known. We examined hMSC lines in vitro for the expression of various Wnt signaling components and for their modulation by TGFβ1, as well as the effect of this cytokine on the photoreceptor differentiation of these cells. Culture of hMSC with a combination of factors that induce photoreceptor differentiation of hMSC (FGF2, taurine, retinoic acid, and insulin-like growth factor type1; FTRI), markedly upregulated the expression of components of the canonical Wnt signaling pathway, including WNT2B, DKK1, and active β-CATENIN. Although FTRI did not modify mRNA expression of WNT5B, a component of the noncanonical/planar cell polarity Wnt pathway, it upregulated its secretion. Furthermore, TGFβ1 not only decreased WNT2B expression, but also inhibited FTRI-induced photoreceptor differentiation of hMSC, as determined by expression of the photoreceptor markers NR2E3, RHODOPSIN, and RECOVERIN. Inhibition of TGFβ1 signaling by an ALK5 inhibitor prevented TGFβ1-induced changes in the expression of the two Wnt ligands examined. More importantly, inhibition of the canonical WNT signaling by XAV-939 prevented FTRI-induced photoreceptor differentiation. These observations suggest that TGFβ may play a key role in preventing neural differentiation of hMSC and may constitute a potential target for induction of endogenous regeneration of the human retina. PMID:26456050

  4. Tls Field Data Based Intensity Correction for Forest Environments

    Science.gov (United States)

    Heinzel, J.; Huber, M. O.

    2016-06-01

    Terrestrial laser scanning (TLS) is increasingly used for forestry applications. Besides the three dimensional point coordinates, the 'intensity' of the reflected signal plays an important role in forestry and vegetation studies. The benefit of the signal intensity is caused by the wavelength of the laser that is within the near infrared (NIR) for most scanners. The NIR is highly indicative for various vegetation characteristics. However, the intensity as recorded by most terrestrial scanners is distorted by both external and scanner specific factors. Since details about system internal alteration of the signal are often unknown to the user, model driven approaches are impractical. On the other hand, existing data driven calibration procedures require laborious acquisition of separate reference datasets or areas of homogenous reflection characteristics from the field data. In order to fill this gap, the present study introduces an approach to correct unwanted intensity variations directly from the point cloud of the field data. The focus is on the variation over range and sensor specific distortions. Instead of an absolute calibration of the values, a relative correction within the dataset is sufficient for most forestry applications. Finally, a method similar to time series detrending is presented with the only pre-condition of a relative equal distribution of forest objects and materials over range. Our test data covers 50 terrestrial scans captured with a FARO Focus 3D S120 scanner using a laser wavelength of 905 nm. Practical tests demonstrate that our correction method removes range and scanner based alterations of the intensity.

  5. Investigating path loss characteristics of UWB signals in vacancy indoor environment based on time-domain technique

    Institute of Scientific and Technical Information of China (English)

    Wang Yang; Zhang Naitong

    2006-01-01

    The path loss analysis model based on 5 rays in vacancy indoor environment is proposed. The relationship between multipath overlapping and the path loss is analyzed mathematically. Time-domain technique is introduced to compute reflection coefficient in a very short time interval. A 5 rays path loss calculation method, which is satisfactory accurate, is developed. 5 typical environments are involved to analyze and generalize the common path loss characteristics in vacancy indoor environment. The simulation result shows that the path loss can be characterized as 3 zones with different path loss exponent as distance between transmitter and receiver increasing.

  6. Low light intensity effects on the growth, photosynthetic characteristics, antioxidant capacity, yield and quality of wheat (Triticum aestivum L.) at different growth stages in BLSS

    Science.gov (United States)

    Dong, Chen; Fu, Yuming; Liu, Guanghui; Liu, Hong

    2014-06-01

    Minimizing energy consumption and maximizing crop productivity are major challenges to growing plants in Bioregenerative Life Support System (BLSS) for future long-term space mission. As a primary source of energy, light is one of the most important environmental factors for plant growth. The purpose of this study is to investigate the effects of low light intensity at different stages on growth, pigment composition, photosynthetic efficiency, biological production and antioxidant defence systems of wheat (Triticum aestivum L.) cultivars during ontogenesis. Experiments were divided into 3 intensity-controlled stages according to growth period (a total of 65 days): seedling stage (first 20 days), heading and flowering stage (middle 30 days) and grain filling stage (last 15 days). Initial light condition of the control was 420 μmol m-2 s-1 and the light intensity increased with the growth of wheat plants. The light intensities of group I and II at the first stage and the last stage were adjusted to the half level of the control respectively. For group III, the first and the last stage were both adjusted to half level of the control. During the middle 30 days, all treatments were kept the same intensity. The results indicated that low-light treatment at seedling stage, biomass, nutritional contents, components of inedible biomass and healthy index (including peroxidase (POD) activity, malondialdehyde (MDA) and proline content) of wheat plants have no significant difference to the control. Furthermore, unit kilojoule yield of group I reached 0.591 × 10-3 g/kJ and induced the highest energy efficiency. However, low-light treatment at grain filling stage affected the final production significantly.

  7. Evaluation of diffuse diseases of the upper abdominal organs by MRI. Determination of a normal range in signal intensity ratio of each organ to the renal medulla in T1- and T2-weighted images and evaluation of diffuse diseases of an organ by using it

    Energy Technology Data Exchange (ETDEWEB)

    Mitsuhashi, Hiroshi [Saint Marianna Univ., Kawasaki, Kanagawa (Japan). School of Medicine

    1995-08-01

    Diffuse diseases of the upper abdominal organs, including the liver, spleen, pancreas, and vertebral marrow, were evaluated by using signal intensity ratio of each organ to the renal medulla in T1- and T2-weighted images. Conventional T1- and T2-weighted images were obtained in 1.5 T MR system in 203 persons, including 122 controls and 81 patients with a diffuse disease in the upper abdominal organ. In controls, though there was neither sexual nor age difference in signal intensity ratios of the liver and pancreas, those of the spleen and vertebral marrow showed sexual and age difference, respectively. A normal range of signal intensity ratio of each organ in each image was determined in each decade of each sex by using controls. The signal intensity ratio of the liver was significantly low in T1- and T2-weighted images in patients with abundant iron deposit and within normal limits in patients with liver cirrhosis or scant iron deposit. The signal intensity ratio of the liver was significantly high only in a T2-weighted image in patients with fatty deposit in the liver, which was suspected to be due to inflammatory change in the liver with fatty deposit. The signal intensity ratios of the spleen, pancreas, and vertebral marrow were significantly low only in a T2-weighted image in patients with iron metabolic disturbance. The signal intensity ratio of the pancreas was significantly high in 40% of patients with acute and/or chronic pancreatitis, which was more sensitive in detection of pancreatitis than data in other studies. it can be concluded that the signal intensity ratio of each organ to the renal medulla in T1- and T2-weighted images is useful for detection of diffuse diseases of the upper abdominal organs by using the normal range in each decade of each sex. (S.Y.).

  8. Characteristics of transitory multi-charged molecular ions produced by an intense femtosecond laser impulse; Etats electroniques des ions moleculaires multicharges transitoires produits par une impulsion laser femtoseconde intense

    Energy Technology Data Exchange (ETDEWEB)

    Quaglia, L

    2001-12-01

    The study of the molecular multi-ionization is narrowly linked to the dynamics of excitation and fragmentation for which the experimental observables rest on the characteristics of the fragmentation products, these characteristics are: intern energy, kinetic energy and charge states. The first chapter sets the problem. The second chapter presents the experimental tools used and developed in this work, the technologies of the detection of ions or of fluorescence are also described. The chapter 3 gathers the theoretical aspects: quantum chemistry and CASSCF (complete active space self consistent field) methods have been used to compute the potential energy curves of multi-charged ions, the two-dimensional hydrodynamic model derived from the Thomas-Fermi model is introduced to tackle the molecular re-orientation. The chapter 4 presents the experimental study of highly excited states by using fluorescence detection methods. The chapter 5 is dedicated to the study of low excited states by measuring kinetic energy spectra and by comparison with potential energy curves of molecular multi-charged ions. The chapter 6 presents experiments with 2 impulses and the results given by the Thomas-Fermi model applied to the re-orientation of the N{sub 2}O molecule. (A.C.)

  9. The characteristics of patients with anemia in emergency intensive care unit%急诊监护病房危重患者贫血特征分析

    Institute of Scientific and Technical Information of China (English)

    车在前; 李英梅; 王兰香; 邵建伟; 望亭松; 陆一鸣; 毛恩强; 陈尔真

    2013-01-01

    目的:探讨危重病患者合并贫血的临床特点及其预后.方法:入选2009年7月至2011年4月急诊重症监护病房(EICU)288例危重病患者,分析其不同性别和年龄段贫血的发生率.按血红蛋白(Hb)水平分为贫血组和对照组,比较其临床特点及预后.住院期间对照组患者Hb低于参考值定义为新发生的贫血,比较住院期间新发生的贫血患者同Hb正常患者的不同临床特点及预后.结果:老年患者占EICU患者的60.8%,不同性别和年龄组之间贫血的发生率无差别.入院时即有贫血的患者占48.3%(男47.0%,女50.0%).入院贫血组患者所需机械通气和肾脏替代治疗较对照组增加(P<0.01),其病死率高于对照组(P<0.05),2组住院时间无统计学差异.住院期间新出现的贫血患者同对照组相比,机械通气和肾脏替代治疗较对照组增加(P<0.05或P<0.01),2组住院时间和病死率无统计学差异.结论:急诊危重病患者常合并贫血,入院贫血和住院期间新发贫血患者机械通气和肾脏替代治疗者更多.贫血患者的临床预后更差.%Objective To investigate the clinical characteristics of severe ill patients with anemia and its prognosis.Methods Two hundred and eighty-eight severe ill patients from July 2009 to April 2011 were enrolled in this study.The incidence of anemia in different gender and age groups were analyzed.According to hemoglobin (Hb) level,the patients were divided into anemia group and non-anemia group,and their clinical features and prognosis were compared.The new onset anemia is defined as Hb less than the value in non-anemia group during hospitalized period.The clinical features and prognosis of the new onset anemia group and non-anemia group were compared.Results Elderly patients accounted for 60.8% of the patients in emergency intensive care unit,and there was no difference between different gender and age groups.The patients had anemia at admission accounted for 48

  10. Signal grass structure at different sites of the same pasture under three grazing intensities - doi: 10.4025/actascianimsci.v35i1.11801

    Directory of Open Access Journals (Sweden)

    Ronan Lopes Albino

    2013-01-01

    Full Text Available The experiment was conducted to evaluate Brachiaria decumbens cv. Basilisk at different sites of the same pasture featuring varying grazing intensities (under grazed, properly grazed and overgrazed. The pasture was managed under continuous stocking using 200-kg cattle and grass height kept at about 25 cm. The randomized block design was used, with three replications. Sward height (38.0 cm and extended plant height (85.2 cm were greater at the under grazed site. The falling index was lower at the properly grazed site (1.28. At the under grazed site, the masses of green leaf blade (3442 kg ha-1 DM, green stem (8370 kg ha-1 DM, green forage (11812 kg ha-1 DM and total forage (14137 kg ha-1 DM were higher when compared to the overgrazed and properly grazed sites. Dead material mass was higher at the properly grazed (3422 kg ha-1 DM and under grazed (2324 kg ha-1 DM sites. At the under grazed sites, there was a higher occurrence of tillers taller than 40 cm. Tillers with sizes between 10 and 30 cm predominated in properly grazed sites. In overgrazed site there was a higher share of tillers with sizes smaller than 20 cm. There is spatial variability of vegetation in the same pasture of Brachiaria decumbens cv. Basilisk due to uneven grazing by cattle.

  11. Chemical weathering intensity and terrigenous flux in South China during the last 90,000 years - evidence from magnetic signals in marine sediments

    Science.gov (United States)

    Yang, Xiaoqiang; Peng, Xuechao; Qiang, Xiaoke; Li, Niu; Zhou, Qixian; Yuejun, Wang

    2016-04-01

    The level of chemical weathering is strongly affected by climate. We presented magnetic properties associated with element ratios from the northern part of the South China Sea to denote links between chemical weathering intensity and monsoon changes in the previous 90,000 years. The magnetic parameter IRMAF80mT/SIRM, representing the variations of high coercivity minerals in marine sediments accompanied with the Al2O3/TiO2 and the Chemical Index of Alteration (CIA), demonstrates strong chemical and physical weathering processes during the last 84-40 kyr when intensified Asian monsoon and warm climate occurred. High susceptibility, TiO2 content, and relatively coarser magnetic mineral grain (relatively low ARM/SIRM ratio) also suggest more terrigenous clastic flux resulting from intensified physical erosion and river transport ability. During the 40-15 kyr period, a low IRMAF80mT/SIRM as well as chemical proxies indicate weak weathering as the climate cooled and precipitation decreased.

  12. Characteristics of a 'HARP' signal processor with analog memory operated with segmented silicon detectors

    Energy Technology Data Exchange (ETDEWEB)

    Anghinolfi, F.; Aspell, P. (CERN, Geneva (Switzerland)); Bonino, R. (Geneva Univ. (Switzerland)) (and others)

    1994-08-01

    For future particle experiments, the detector systems will have a large number of detecting elements, and these will provide raw data at [approximately] 50 MHz rates. As an example, the silicon outer tracker (SIT) for the ATLAS detector may consist of 5 planes of silicon strip and pad detectors with 390,000 independent channels per plane. The signal processing electronics must comply with the strong limitation on electrical power and cooling in the central barrel. A 32 channel analog VLSI detector readout chip (HARP32) with an input charge preamplifier, a 64-cell current integrating analog memory in each channel and a common analog multiplexer, has been used in a test beam with segmented silicon detectors. The device was operated at the LHC clock speed of 66 MHz. The different pedestal variations seen at the output are analyzed: the input noise [sigma][sub n] amounts to 2.8mV r.m.s., the pedestal non-uniformity in channel [sigma][sub ped] to 1.2mV r.m.s., the channel to channel pedestal variation [sigma][sub ch] to 4.0mV r.m.s., and an output baseline shift [sigma][sub obs] of 3.5mV r.m.s. has been observed.

  13. 刀具磨损声发射信号的混沌特性分析%Chaotic characteristic analysis of tool wear acoustic emission signal

    Institute of Scientific and Technical Information of China (English)

    关山; 彭昶

    2015-01-01

    In metal cutting process, surface quality and dimensional accuracy of the work piece is affected by cutting-tool wear condition. So it is important to study the cutting-tool wear, especially in automation production. Cutting-tool wear is a complex process; it is affected by various factors like cutting parameters, material characteristics and cutting environment, etc. Metal cutting is a nonlinear system; there are a lot of non-stationary signals used in condition monitoring and fault diagnosis. Vibration, force and acoustic emission (AE) are the typical signal type widely used in cutting-tool wear research. In this paper, we chose AE signal to be the carrier in analyzing cutting-tool wear. AE is the class of phenomena where transient elastic waves are generated by the rapid release of energy when the materials are distorted or under the outside load. The AE signal produced by cutting -tool wear is high-frequency and the bandwidth is nearly 50 kHz-1 MHz, so it can weaken the influence of low-frequency noise like mechanical noise and ambient noise. The measured signal sometimes contains high-frequency noise. In this paper, chaos theory was used in analyzing the nonlinear characteristics of the AE signal. Chaos theory is sensitive to noise; therefore, noise reduction was done with the method based on empirical mode decomposition and wavelet (EMD-Wavelet) before computing. The signal were decomposed into several intrinsic mode functions which was from high-frequency to low-frequency by use of EMD, then it was used to determine the noise dominated intrinsic mode functions based on consecutive mean square error (CMSE) proposed by Boudraa and then restrained them. A new signal were reconstructed by adding the rest intrinsic mode functions together and a further and last de-noising was using wavelet to processing the new one in order to get more pure signal. Before extracting the chaotic character, an important step was to reconstruct a phase space from the de

  14. Selective attention and the auditory vertex potential. I - Effects of stimulus delivery rate. II - Effects of signal intensity and masking noise

    Science.gov (United States)

    Schwent, V. L.; Hillyard, S. A.; Galambos, R.

    1976-01-01

    The effects of varying the rate of delivery of dichotic tone pip stimuli on selective attention measured by evoked-potential amplitudes and signal detectability scores were studied. The subjects attended to one channel (ear) of tones, ignored the other, and pressed a button whenever occasional targets - tones of a slightly higher pitch were detected in the attended ear. Under separate conditions, randomized interstimulus intervals were short, medium, and long. Another study compared the effects of attention on the N1 component of the auditory evoked potential for tone pips presented alone and when white noise was added to make the tones barely above detectability threshold in a three-channel listening task. Major conclusions are that (1) N1 is enlarged to stimuli in an attended channel only in the short interstimulus interval condition (averaging 350 msec), (2) N1 and P3 are related to different modes of selective attention, and (3) attention selectivity in multichannel listening task is greater when tones are faint and/or difficult to detect.

  15. Cluster analysis of signal-intensity time course in dynamic breast MRI: does unsupervised vector quantization help to evaluate small mammographic lesions?

    Energy Technology Data Exchange (ETDEWEB)

    Leinsinger, Gerda; Schlossbauer, Thomas; Scherr, Michael; Lange, Oliver; Reiser, Maximilian; Wismueller, Axel [Institute for Clinical Radiology University of Munich, Munich (Germany)

    2006-05-15

    We examined whether neural network clustering could support the characterization of diagnostically challenging breast lesions in dynamic magnetic resonance imaging (MRI). We examined 88 patients with 92 breast lesions (51 malignant, 41 benign). Lesions were detected by mammography and classified Breast Imaging and Reporting Data System (BIRADS) III (median diameter 14 mm). MRI was performed with a dynamic T1-weighted gradient echo sequence (one precontrast and five postcontrast series). Lesions with an initial contrast enhancement {>=}50% were selected with semiautomatic segmentation. For conventional analysis, we calculated the mean initial signal increase and postinitial course of all voxels included in a lesion. Secondly, all voxels within the lesions were divided into four clusters using minimal-free-energy vector quantization (VQ). With conventional analysis, maximum accuracy in detecting breast cancer was 71%. With VQ, a maximum accuracy of 75% was observed. The slight improvement using VQ was mainly achieved by an increase of sensitivity, especially in invasive lobular carcinoma and ductal carcinoma in situ (DCIS). For lesion size, a high correlation between different observers was found (R{sup 2} = 0.98). VQ slightly improved the discrimination between malignant and benign indeterminate lesions (BIRADS III) in comparison with a standard evaluation method. (orig.)

  16. Dose Reduction in Contrast-Enhanced Cervical MR Angiography: Field Strength Dependency of Vascular Signal Intensity, Contrast Administration, and Arteriographic Quality.

    Science.gov (United States)

    Dehkharghani, Seena; Qiu, Deqiang; Albin, Lauren S; Saindane, Amit M

    2015-06-01

    Cervical contrast-enhanced MR angiography (MRA) has proven accurate and superior to noncontrast alternatives. We proposed the systematic investigation of dose reduction in contrast-enhanced MRA, hypothesizing heightened tolerance at 3 T vs 1.5 T. Quantitative and qualitative features were compared between full-dose and 50%-reduced dose examinations at 1.5 T and 3 T. One hundred eight cervical contrast-enhanced MRA examinations were reviewed for qualitative and quantitative (signal-to-noise ratio [SNR] and contrast-to-noise ratio [CNR]) features across four dose-field strength combinations: 1.5 T, 0.05 mmol/kg; 3 T, 0.05 mmol/kg; 1.5 T, 0.1 mmol/kg; and 3 T, 0.1 mmol/kg. Quantitative features were evaluated among the following segments: aortic arch, common carotid arteries, common carotid bifurcations, and cervical internal carotid arteries. A qualitative visual rating scale was applied for the same segments as well as to the vertebral arteries along their proximal (V1), intraforaminal (V2), and distal extraforaminal (V3) courses. Significant between-group differences were reported at p contrast-enhanced MRA is feasible at 3 T without significant compromise in arteriographic quality in most segments. Particularly at 3 T, arteriography is quantitatively and qualitatively robust and may be advisable in high-risk patients.

  17. Traceability of Acoustic Emission measurements for a proposed calibration method - Classification of characteristics and identification using signal analysis

    Science.gov (United States)

    Griffin, James

    2015-01-01

    When using Acoustic Emission (AE) technologies, tensile, compressive and shear stress/strain tests can provide a detector for material deformation and dislocations. In this paper improvements are made to standardise calibration techniques for AE against known metrics such as force. AE signatures were evaluated from various calibration energy sources based on the energy from the first harmonic (dominant energy band) [1,2]. The effects of AE against its calibration identity are investigated: where signals are correlated to the average energy and distance of the detected phenomena. In addition, extra tests are investigated in terms of the tensile tests and single grit tests characterising different materials. Necessary translations to the time-frequency domain were necessary when segregating salient features between different material properties. Continuing this work the obtained AE is summarised and evaluated by a Neural Network (NN) regression classification technique which identifies how far the malformation has progressed (in terms of energy/force) during material transformation. Both genetic-fuzzy clustering and tree rule based classifier techniques were used as the second and third classification techniques respectively to verify the NN output giving a weighted three classifier system. The work discussed in this paper looks at both distance and force relationships for various prolonged Acoustic Emission stresses. Later such analysis was realised with different classifier models and finally implemented into the Simulink simulations. Further investigations were made into classifier models for different material interactions in terms of force and distance which add further dimension to this work with different materials based simulation realisations. Within the statistical analysis section there are two varying prolonged stress tests which together offer the mechanical calibration system (automated solenoid and pencil break calibration system). Taking such a

  18. Analysis of computer-aided detection techniques and signal characteristics for clustered microcalcifications on digital mammography and digital breast tomosynthesis

    Science.gov (United States)

    Samala, Ravi K.; Chan, Heang-Ping; Hadjiiski, Lubomir M.; Helvie, Mark A.

    2016-10-01

    With IRB approval, digital breast tomosynthesis (DBT) images of human subjects were collected using a GE GEN2 DBT prototype system. Corresponding digital mammograms (DMs) of the same subjects were collected retrospectively from patient files. The data set contained a total of 237 views of DBT and equal number of DM views from 120 human subjects, each included 163 views with microcalcification clusters (MCs) and 74 views without MCs. The data set was separated into training and independent test sets. The pre-processing, object prescreening and segmentation, false positive reduction and clustering strategies for MC detection by three computer-aided detection (CADe) systems designed for DM, DBT, and a planar projection image generated from DBT were analyzed. Receiver operating characteristic (ROC) curves based on features extracted from microcalcifications and free-response ROC (FROC) curves based on scores from MCs were used to quantify the performance of the systems. Jackknife FROC (JAFROC) and non-parametric analysis methods were used to determine the statistical difference between the FROC curves. The difference between the CADDM and CADDBT systems when the false positive rate was estimated from cases without MCs did not reach statistical significance. The study indicates that the large search space in DBT may not be a limiting factor for CADe to achieve similar performance as that observed in DM.

  19. Carcass characteristics and fat depots in Iberian and F Large White × Landrace pigs intensively finished or raised outdoors in oak-tree forests.

    Science.gov (United States)

    Bressan, M C; Almeida, J; Santos Silva, J; Bettencourt, C; Francisco, A; Gama, L T

    2016-06-01

    A factorial experiment was performed with 117 barrows belonging to the Iberian (IB) and crossbred F Large White × Landrace (F) genetic groups, either intensively finished (IN) or finished outdoors on pasture in an oak and cork tree forest (EX). Information was collected on carcass weight, yield, and dimensions; weight of organs, carcass cuts, and abdominal fat depots; backfat depth; measurements of the longissimus thoracis (LT); and yield of different leg tissues. For the 41 slaughter and carcass traits analyzed, the interaction between genetic group and finishing system was significant ( 0.05), indicating that it is feasible to reduce subcutaneous and abdominal fat without compromising IMF and meat quality.

  20. Effect of gate-length shortening on the terahertz small-signal and self-oscillations characteristics of field-effect transistors

    Science.gov (United States)

    Starikov, E.; Shiktorov, P.; Gružinskis, V.; Marinchio, H.; Palermo, C.; Varani, L.

    2015-12-01

    We investigate the shortening of the gate-length in submicrometric and nanometric field-effect transistors as a powerful tool to improve their self-oscillations performances in the terahertz frequency region due to the appearance of the Dyakonov-Shur instability. The theoretical model is based on the numerical solution of hydrodynamic equations for the electron transport in FETs/HEMTs channels. We show that a decrease of the gate length allows, on the one hand, to increase the intrinsic resonant frequencies near 1 THz and, on the other hand, to improve the conditions for the onset of the Dyakonov-Shur instability and related phenomena. The small-signal characteristics calculated under constant drain-voltage operation are compared with the drain-voltage self-oscillations calculated under constant drain-current operation.

  1. Intensity techniques

    DEFF Research Database (Denmark)

    Jacobsen, Finn

    2008-01-01

    The Handbook of Signal Processing in Acoustics will compile the techniques and applications of signal processing as they are used in the many varied areas of Acoustics. The Handbook will emphasize the interdisciplinary nature of signal processing in acoustics. Each Section of the Handbook...... will present topics on signal processing which are important in a specific area of acoustics. These will be of interest to specialists in these areas because they will be presented from their technical perspective, rather than a generic engineering approach to signal processing. Non-specialists, or specialists...... from different areas, will find the self-contained chapters accessible and will be interested in the similarities and differences between the approaches and techniques used in different areas of acoustics....

  2. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn

    1997-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  3. Sound Intensity

    DEFF Research Database (Denmark)

    Crocker, M.J.; Jacobsen, Finn

    1997-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  4. Sound intensity

    DEFF Research Database (Denmark)

    Crocker, Malcolm J.; Jacobsen, Finn

    1998-01-01

    This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique.......This chapter is an overview, intended for readers with no special knowledge about this particular topic. The chapter deals with all aspects of sound intensity and its measurement from the fundamental theoretical background to practical applications of the measurement technique....

  5. Lung carcinogenesis from chronic obstructive pulmonary disease: characteristics of lung cancer from COPD and contribution of signal transducers and lung stem cells in the inflammatory microenvironment.

    Science.gov (United States)

    Sekine, Yasuo; Hata, Atsushi; Koh, Eitetsu; Hiroshima, Kenzo

    2014-07-01

    Chronic obstructive pulmonary disease (COPD) and lung cancer are closely related. The annual incidence of lung cancer arising from COPD has been reported to be 0.8-1.7 %. Treatment of lung cancer from COPD is very difficult due to low cardiopulmonary function, rapid tumor growth, and resistance to molecularly targeted therapies. Chronic inflammation caused by toxic gases can induce COPD and lung cancer. Carcinogenesis in the inflammatory microenvironment occurs during cycles of tissue injury and repair. Cellular damage can induce induction of necrotic cell death and loss of tissue integrity. Quiescent normal stem cells or differentiated progenitor cells are introduced to repair injured tissues. However, inflammatory mediators may promote the growth of bronchioalveolar stem cells, and activation of NF-κB and signal transducer and activator of transcription 3 (STAT3) play crucial roles in the development of lung cancer from COPD. Many of the protumorgenic effects of NF-κB and STAT3 activation in immune cells are mediated through paracrine signaling. NF-κB and STAT3 also contribute to epithelial-mesenchymal transition. To improve lung cancer treatment outcomes, lung cancer from COPD must be overcome. In this article, we review the characteristics of lung cancer from COPD and the mechanisms of carcinogenesis in the inflammatory microenvironment. We also propose the necessity of identifying the mechanisms underlying progression of COPD to lung cancer, and comment on the clinical implications with respect to lung cancer prevention, screening, and therapy.

  6. Analysis of the pen pressure and grip force signal during basic drawing tasks: The timing and speed changes impact drawing characteristics.

    Science.gov (United States)

    Gatouillat, Arthur; Dumortier, Antoine; Perera, Subashan; Badr, Youakim; Gehin, Claudine; Sejdić, Ervin

    2017-08-01

    Writing is a complex fine and trained motor skill, involving complex biomechanical and cognitive processes. In this paper, we propose the study of writing kinetics using three angles: the pen-tip normal force, the total grip force signal and eventually writing quality assessment. In order to collect writing kinetics data, we designed a sensor collecting these characteristics simultaneously. Ten healthy right-handed adults were recruited and were asked to perform four tasks: first, they were instructed to draw circles at a speed they considered comfortable; they then were instructed to draw circles at a speed they regarded as fast; afterwards, they repeated the comfortable task compelled to follow the rhythm of a metronome; and eventually they performed the fast task under the same timing constraints. Statistical differences between the tasks were computed, and while pen-tip normal force and total grip force signal were not impacted by the changes introduced in each task, writing quality features were affected by both the speed changes and timing constraint changes. This verifies the already-studied speed-accuracy trade-off and suggest the existence of a timing constraints-accuracy trade-off. Copyright © 2017 Elsevier Ltd. All rights reserved.

  7. Alternatives to Pyrotechnic Distress Signals; Laboratory and Field Studies

    Science.gov (United States)

    2015-03-01

    evaluating the relative effectiveness of various colors under low light (about 0.25 foot candle ) conditions. Quoting Smith, “When the colors included in the...evaluating color , flash pattern, and intensity for an LED distress signal, conspicuous against certain lighting conditions, at six nautical miles, in...characteristic, effective intensity, color , flash pattern, response time, conspicuity 18. Distribution Statement Distribution Statement A: Approved

  8. Dose-Dependent Effects of L-Arginine on PROP Bitterness Intensity and Latency and Characteristics of the Chemical Interaction between PROP and L-Arginine.

    Directory of Open Access Journals (Sweden)

    Melania Melis

    Full Text Available Genetic variation in the ability to taste the bitterness of 6-n-propylthiouracil (PROP is a complex trait that has been used to predict food preferences and eating habits. PROP tasting is primarily controlled by polymorphisms in the TAS2R38 gene. However, a variety of factors are known to modify the phenotype. Principle among them is the salivary protein Ps-1 belonging to the basic proline-rich protein family (bPRP. Recently, we showed that oral supplementation with Ps-1 as well as its related free amino acids (L-Arg and L-Lys enhances PROP bitterness perception, especially for PROP non-tasters who have low salivary levels of Ps-1. Here, we show that salivary L-Arg levels are higher in PROP super-tasters compared to medium tasters and non-tasters, and that oral supplementation with free L-Arg enhances PROP bitterness intensity as well as reduces bitterness latency in a dose-dependent manner, particularly in individuals with low salivary levels of both free L-Arg and Ps-1 protein. Supplementation with L-Arg also enhanced the bitterness of caffeine. We also used 1H-NMR spectroscopy and quantum-mechanical calculations carried out by Density Functional Theory (DFT to characterize the chemical interaction between free L-Arg and the PROP molecule. Results showed that the -NH2 terminal group of the L-ArgH+ side chain interacts with the carbonyl or thiocarbonyl groups of PROP by forming two hydrogen bonds with the resulting charged adduct. The formation of this PROP•ArgH+ hydrogen-bonded adduct could enhance bitterness intensity by increasing the solubility of PROP in saliva and its availability to receptor sites. Our data suggest that L-Arg could act as a 'carrier' of various bitter molecules in saliva.

  9. Dose-Dependent Effects of L-Arginine on PROP Bitterness Intensity and Latency and Characteristics of the Chemical Interaction between PROP and L-Arginine.

    Science.gov (United States)

    Melis, Melania; Arca, Massimiliano; Aragoni, Maria Carla; Cabras, Tiziana; Caltagirone, Claudia; Castagnola, Massimo; Crnjar, Roberto; Messana, Irene; Tepper, Beverly J; Tomassini Barbarossa, Iole

    2015-01-01

    Genetic variation in the ability to taste the bitterness of 6-n-propylthiouracil (PROP) is a complex trait that has been used to predict food preferences and eating habits. PROP tasting is primarily controlled by polymorphisms in the TAS2R38 gene. However, a variety of factors are known to modify the phenotype. Principle among them is the salivary protein Ps-1 belonging to the basic proline-rich protein family (bPRP). Recently, we showed that oral supplementation with Ps-1 as well as its related free amino acids (L-Arg and L-Lys) enhances PROP bitterness perception, especially for PROP non-tasters who have low salivary levels of Ps-1. Here, we show that salivary L-Arg levels are higher in PROP super-tasters compared to medium tasters and non-tasters, and that oral supplementation with free L-Arg enhances PROP bitterness intensity as well as reduces bitterness latency in a dose-dependent manner, particularly in individuals with low salivary levels of both free L-Arg and Ps-1 protein. Supplementation with L-Arg also enhanced the bitterness of caffeine. We also used 1H-NMR spectroscopy and quantum-mechanical calculations carried out by Density Functional Theory (DFT) to characterize the chemical interaction between free L-Arg and the PROP molecule. Results showed that the -NH2 terminal group of the L-ArgH+ side chain interacts with the carbonyl or thiocarbonyl groups of PROP by forming two hydrogen bonds with the resulting charged adduct. The formation of this PROP•ArgH+ hydrogen-bonded adduct could enhance bitterness intensity by increasing the solubility of PROP in saliva and its availability to receptor sites. Our data suggest that L-Arg could act as a 'carrier' of various bitter molecules in saliva.

  10. An empirical study on the relationships between CEO characteristics, R&D intensity, and external environment%CEO特征、R&D强度以及外部环境关系的实证研究

    Institute of Scientific and Technical Information of China (English)

    宁静; 井润田

    2009-01-01

    采用世界银行投资环境调查(ICS)中来自中国、巴西、南非企业的数据,研究CEO人口统计学特征对R&D强度的影响,以及社会文化、政府政策、法律体系在二者关系中的调节作用.实证分析的结果表明,CEO教育水平、工作经验(担任CEO前在本产业的工作时间)和R&D强度之间并无显著相关关系.社会文化对CEO特征和R&D强度之间的关系有显著的调节作用,中国、巴西两国的CEO教育水平、工作经验和R&D强度之间的正相关性显著高于南非.政府政策在CEO教育水平和R&D强度之间发挥负向调节作用,政府政策越不稳定,CEO的教育水平和R&D强度之间的正相关性越强;但政府政策对CEO工作经验和R&D强度之间关系的调节作用不显著.法律体系并未在CE0特征和R&D强度之间发挥调节作用.%Using firm - level data from the Investment Climate Surveys conducted by the World Bank in China,Brazil,and South Africa,the relationships between CEO' s demographic characteristics and R&D intensity and the moderating effects of social culture,and government policy,and legal system on the relationship are investigated.Neither CEO' s education level nor his/her work experience (the years of experience working in same sector before they become CEO's) was found to have a significant impact on R&D intensity.Social culture significantly moderated the relationship between CEO' s education level and R&D intensity and that between CEO' s work experience and R&D intensity ; the positive relationship between CEO' s education level and R&D intensity and that between CEO's work experience and R&D intensity in China and Brazil were both significantly stronger than those in South Africa.The government policy negatively moderated the relationship between CEO's education level and R&D intensity; the more unstable the government policy,the stronger positive relationship between CEO' s education level and R&D intensity.But the government policy

  11. Optimization of nuclear magnetic resonance refocusing pulses to enhance signal intensity in gradient B0 field∗%优化重聚脉冲提高梯度场核磁共振信号强度*

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    It is an efficient protocol to use the refocusing flip angle pulse optimization technique to solve special engineering technical problems in nuclear magnetic resonance (NMR) measurements. By reducing RF pulse duration, the low refocusing flip angle pulses can consume lower power, satisfy specific absorption rate of samples, and improve signal-to-noise ratio as well. To further analyze the function mechanism of pulse angles, the dependence of signal intensity on RF pulse is studied in homogenous magnetic field and constant gradient magnetic field respectively. Afterwards, echo amplitudes with various tip angles and flip angles ranging from 0◦ to 180◦ are compared with conventional sequence of 90◦ pulse followed by 180◦ pulses theoretically and experimentally. For the constant gradient field, the refocusing pulse of flip angle can be as low as 140◦, defined as the optimum herein, to obtain the strongest signal intensity, enhanced by 13%compared with that of 180◦. Moreover, T1 distributions measured by the conventional and optimal sequences for distilled water at room temperature are compared, and good conformances of T1 between the two pulse sequences are obtained, which demonstrates the optimal refocusing pulse can be directly applied to T1 measurement. The results provide constructive suggestion for designing pulse sequences for signal intensity enhancement in NMR logging while drilling and NMR online quick analysis.%  缩短射频脉冲宽度,有助于解决脉冲电力消耗大、样品吸收率高、信噪比低等极端条件核磁共振探测的关键问题。本文首先分析射频脉冲角度对核磁共振自旋回波信号强度的影响机理,基于Bloch方程推导了回波信号幅度与扳转角、重聚角的关系。在特制核磁共振分析仪上采用变脉冲角度技术,分别在均匀磁场和梯度磁场条件下实现对扳转角和重聚角与回波信号强度关系的数值模拟和实验测量。结果表明,

  12. Burden and characteristics of influenza A and B in Danish intensive care units during the 2009/10 and 2010/11 influenza seasons

    DEFF Research Database (Denmark)

    Gubbels, S; Krause, Tyra Grove; Bragstad, Karoline

    2013-01-01

    . Additional data on microbiological testing, vaccination and death were obtained from national registers. Ninety-six patients with influenza A(H1N1)pdm09 were recorded in 2009/10; 106 with influenza A and 42 with influenza B in 2010/11. The mean age of influenza A patients was higher in 2010/11 than in 2009......SUMMARY Influenza surveillance in Danish intensive care units (ICUs) was performed during the 2009/10 and 2010/11 influenza seasons to monitor the burden on ICUs. All 44 Danish ICUs reported aggregate data for incidence and point prevalence, and case-based demographical and clinical parameters....../10, 53 vs. 44 years (P=0·004). No differences in other demographic and clinical parameters were detected between influenza A and B patients. In conclusion, the number of patients with severe influenza was higher in Denmark during the 2010/11 than the 2009/10 season with a shift towards older age groups...

  13. Characteristics and outcome of infants with candiduria in neonatal intensive care - a Paediatric Investigators Collaborative Network on Infections in Canada (PICNIC study

    Directory of Open Access Journals (Sweden)

    Langley Joanne M

    2009-11-01

    Full Text Available Abstract Background There is limited information in the literature on the presentation and prognosis of candidal urinary tract infection (UTI in infants in the neonatal intensive care unit (NICU. Methods This was a prospective cohort study performed in 13 Canadian NICUs. Infants with candidal UTI without extra-renal candidal infection at presentation were enrolled. Results Thirty infants fit the study criteria. Median birth weight and gestational age were 2595 grams (range 575-4255 and 35 weeks (range 24-41 with 10 infants being Conclusion Candidal UTI in the NICU population occurs both in term infants with congenital abnormalities and in preterm infants, and is associated with renal parenchymal disease and extra-renal dissemination. A wide variation in clinical approach was documented in this multicenter study. The overall mortality rate in these infants was significant (30%. In one third of the deaths, Candida infection was deemed to be a contributing factor, suggesting the need for antifungal therapy with repeat evaluation for dissemination in infants who are slow to respond to therapy.

  14. Obstetric critical care: A prospective analysis of clinical characteristics, predictability, and fetomaternal outcome in a new dedicated obstetric intensive care unit

    Directory of Open Access Journals (Sweden)

    Sunanda Gupta

    2011-01-01

    Full Text Available A 1 year prospective analysis of all critically ill obstetric patients admitted to a newly developed dedicated obstetric intensive care unit (ICU was done in order to characterize causes of admissions, interventions required, course and foetal maternal outcome. Utilization of mortality probability model II (MPM II at admission for predicting maternal mortality was also assessed.During this period there were 16,756 deliveries with 79 maternal deaths (maternal mortality rate 4.7/1000 deliveries. There were 24 ICU admissions (ICU utilization ratio 0.14% with mean age of 25.21±4.075 years and mean gestational age of 36.04±3.862 weeks. Postpartum admissions were significantly higher (83.33% n=20, P<0.05 with more patients presenting with obstetric complications (91.66%, n=22, P<0.01 as compared to medical complications (8.32% n=2. Obstetric haemorrhage (n=15, 62.5% and haemodynamic instability (n=20, 83.33% were considered to be significant risk factors for ICU admission (P=0.000. Inotropic support was required in 22 patients (91.66% while 17 patients (70.83% required ventilatory support but they did not contribute to risk factors for poor outcome. The mean duration of ventilation (30.17±21.65 h and ICU stay (39.42±33.70 h were of significantly longer duration in survivors (P=0.01, P=0.00 respectively versus non-survivors. The observed mortality (n=10, 41.67% was significantly higher than MPM II predicted death rate (26.43%, P=0.002. We conclude that obstetric haemorrhage leading to haemodynamic instability remains the leading cause of ICU admission and MPM II scores at admission under predict the maternal mortality.

  15. Obstetric critical care: A prospective analysis of clinical characteristics, predictability, and fetomaternal outcome in a new dedicated obstetric intensive care unit.

    Science.gov (United States)

    Gupta, Sunanda; Naithani, Udita; Doshi, Vimla; Bhargava, Vaibhav; Vijay, Bhavani S

    2011-03-01

    A 1 year prospective analysis of all critically ill obstetric patients admitted to a newly developed dedicated obstetric intensive care unit (ICU) was done in order to characterize causes of admissions, interventions required, course and foetal maternal outcome. Utilization of mortality probability model II (MPM II) at admission for predicting maternal mortality was also assessed. During this period there were 16,756 deliveries with 79 maternal deaths (maternal mortality rate 4.7/1000 deliveries). There were 24 ICU admissions (ICU utilization ratio 0.14%) with mean age of 25.21±4.075 years and mean gestational age of 36.04±3.862 weeks. Postpartum admissions were significantly higher (83.33% n=20, Pobstetric complications (91.66%, n=22, PObstetric haemorrhage (n=15, 62.5%) and haemodynamic instability (n=20, 83.33%) were considered to be significant risk factors for ICU admission (P=0.000). Inotropic support was required in 22 patients (91.66%) while 17 patients (70.83%) required ventilatory support but they did not contribute to risk factors for poor outcome. The mean duration of ventilation (30.17±21.65 h) and ICU stay (39.42±33.70 h) were of significantly longer duration in survivors (P=0.01, P=0.00 respectively) versus non-survivors. The observed mortality (n=10, 41.67%) was significantly higher than MPM II predicted death rate (26.43%, P=0.002). We conclude that obstetric haemorrhage leading to haemodynamic instability remains the leading cause of ICU admission and MPM II scores at admission under predict the maternal mortality.

  16. The characteristic of Indonesia's pre-eclampsia: From obstetric intensive care with ventilator until epidemiologic and its molecular biology profile of pulmonary edema in severe pre-eclampsia.

    Science.gov (United States)

    Hermanto; Adityawarman; Sulistyono; Ardian, M; Dachlan, E G

    2014-07-01

    Pulmonary edema is among the least frequently diagnosed criteria for severe pre-eclampsia. A higher incidence of pulmonary edema was noted in older patients, multigravidas, and patients with underlying chronic hypertension that developed prior to delivery. The development of pulmonary edema was also associated with the administration of excess colloid or crystaloid infusion. Two hundreds and thirty millions people occupying Indonesia as tropical and coastal country gave rise the problem of highly maternal mortality rate of 225/100,000 deliveries where pre-eclampsia and eclampsia as most possible cause. Over 5years from the year 2005 through 2009 our 160 eclampsia study observed about significantly correlation between typical estafet referred case and maternal mortality (Odds ratio 19.1 and P=0.065). Specifically those referred eclampsia cases arriving lately to our tertiary hospital, complication of pulmonary edema also apparently became determinant factor to uphold the increased maternal mortality (Odds ratio 6.1 and P=0.083) We found at our teaching hospital Dr. Soetomo Surabaya as referral center along the year 2012, 477 pre-eclampsia-eclampsia cases which complicated by 27 cases of pulmonary from which we apply obstetric intensive care unit for tightly monitoring treatment. The majority use of ventilator were applied on 22 cases (81.4%), that most approximately 16 cases (72%) need 48h under ventilator use and the remaining 6 cases was not untill 5days of extubation. The etiology of pulmonary edema in preeclamptic patients involves multi-factors; abnormal COP-PWCP gradient, increased pulmonary capillary permeability, and left ventricular failure were identified causes. It has been well known that the pathogenesis of pulmonary edema in severe pre-eclampsia-eclampsia initiated by capillary alveolar leakage that leading increased capillary permeability and extravascular fluid oncotic as well as decreased plasma oncotic pressure. In severe pre-eclampsia appear that

  17. Feasibility of predicting the microwave ablation energy for uterine leiomyomas with MRI signal intensity%MRI信号强度预测子宫肌瘤微波消融能量的可行性

    Institute of Scientific and Technical Information of China (English)

    马霞; 张晶; 韩治宇; 蔡剑鸣; 周洪雨; 徐瑞芳; 杨宇; 郝艳丽

    2013-01-01

    目的 探讨根据MR T2WI信号强度预测微波消融子宫肌瘤所需能量的可行性.方法 于超声引导对143例子官肌瘤患者(共197个病灶)行经皮微波消融治疗,对其中42例(49个病灶)于微波消融术前、术后进行盆腔平扫+ MR增强扫描.微波消融功率为50 W,微波天线型号均为T11a.术前根据MR T2WI中子宫肌层信号强度为标准,将子宫肌瘤分为高、等、低信号3组;消融后测量增强MRI中无灌注区体积作为消融体积,对子宫肌瘤微波消融能效因子进行统计学分析.结果 低、等、高信号组子宫肌瘤微波消融平均能效因子分别为(685.01士206.27)J/cm3、(702.70土254.25)J/cm3和(945.12±321.83)J/cm3,高信号组与低信号组比较差异有统计学意义(P=0.015).结论 根据MR T2WI中子宫肌瘤的信号强度可初步预测微波消融所需能量;微波消融中,T2WI呈高信号的子宫肌瘤所需能量高于呈低信号者.%Objective To evaluate the feasibility of signal intensity at MR T2WI for predicting microwave (MW) ablation energy of uterine leiomyoma.Methods Totally 143 patients with 197 uterine leiomyomas who underwent ultrasoundguided percutaneous MW ablation treatment were prospectively observed.Among them,42 patients with 49 uterine leiomyomas received contrast-enhanced MR imaging (ceMRI) before and after MW ablation,the output energy was set at 50 W,and MW antennas T11a were used.Taking MR T2WI signal intensity of myometrium as reference standard,uterine leiomyomas were classified into three groups,i.e.hyperintensity group,isointensity group and hypointensity group.After MW ablation,the volume of nonperfused area on ceMRI was calculated as MW ablation volume.Energy required per unit volume (EPV) was analyzed statistically.Results The mean EPVs were (685.01±206.27)J/cm3 in hypointense group,(702.70±254.25)J/cm3 in isosignal group and (945.12±321.83)J/cm3 in hyperintense group.There was significant difference of EPV between

  18. Potential use of microbubbles (MBs) as contrast material in x-ray dark field (DF) imaging: How does the DF signal change with the characteristic parameters of the MBs?

    Science.gov (United States)

    Zhang, Ran; Qin, Bin; Ge, Yongshuai; Whiting, Bruce; Li, Ke; Villanueva, Flordeliza; Chen, Guang-Hong

    2016-03-01

    One of the most exciting aspects of the grating based x-ray differential phase contrast (DPC) acquisition method is the concurrent generation of the so-called dark field (DF) signal, along with the classical absorption signal and the novel DPC signal. The DF signal is associated with local distribution of small angle scatterers in an image object, while the absorption signal and DPC signal are often used to characterize the relatively uniform structure of the image object. Besides the endogenous image contrast, exogenous contrast media are often used in x-ray imaging to locally enhance the image signal. This paper proposes a potential contrast medium for DF signal enhancement: microbubbles (MBs). MBs have already been developed for clinical use in ultrasound imaging, and recent experimental studies have shown that MBs may also enhance the DF signal, although it remained unclear how the physical characteristics of the MBs quantitatively impact the DF signal. In this paper, a systematic study was performed to investigate the quantitative relationships between the DF signal and the following properties of MBs: size, concentration, shell thickness, size uniformity, and whether gold nanoparticles were attached. The experimental results demonstrated that, an increased MB size (about 4 microns) may generate a stronger DF signal for our DPC imaging system; additionally, a moderately increased shell thickness and the use of gold nanoparticles on the shell surface also resulted in further enhancement of the DF signal. These findings may provide critical information needed for using MBs as the contrast agent of x-ray DF imaging.

  19. Survey of characteristics of neonatal death in neonatal intensive care unit of Boo-Ali Sina educational & therapeutic center between 2003-2006

    Directory of Open Access Journals (Sweden)

    Azita Bala Ghafari

    2009-01-01

    Full Text Available , , , (Received 24 June, 2009 ; Accepted 16 September, 2009AbstractBackground and purpose: The neonatal mortality rate is an important index for evaluation of public health. It involves the death of infants under 28 days. Obviously, recognizing the characteristics of neonatal mortality in this center, may be useful for promoting the procedures in the NICU, as well as planning to impede the severe complications or death.Materials and methods: This is a descriptive study performed by analyzing the available data from the medical records of NICU patients at Boo-Ali Sina Educational & Therapeutic Center during 2003 and 2006. The number of deaths, names, and medical records number of the dead infants were collected. Among 1238 patients in the NICU, 363 deaths were reported. According to medical records, 222 deaths occurred in neonates aged 0 to 27 days. Data were collected using a checklist, the validity and reliability of which were approved by clinicians. The Descriptive methods were used in analyzing the data.Results: The findings include: 140 subjects were male (63.1%; 72 from single birth (77.5%; the age-group of mothers of 38 cases (37.7% was 20-24 y; 132 cases (59.5% resided in villages; 129 cases (58.1% with prenatal care; 120 cased of Caesarian section (54%; 155 cases (76% with birth weight lower than 2500 grams and 154 preterm (75.5%. Mortality during neonatal period was divided in two groups: early death (0-6 days 142 cases (62% and late death (7-27 days 80 cases (36%.Conclusion: Correct and exact completion of NICU forms would help undertaking descriptive and analytic epidemiologic studies.Key words: Neonatal mortality, early neonatal mortality, late neonatal mortality, NICUJ Mazand Univ Med Sci 2009; 20(74: 79-83 (Persian

  20. Comparison of the reliability of subjective evaluation and quantitative measurements of MR signal intensity in inflammations of the intratemporal facial nerve; Vergleich der Reliabilitaet von subjektiver Beurteilung und quantitativer Messung der MR-Signalintensitaet bei Entzuendungen des intratemporalen N. facialis

    Energy Technology Data Exchange (ETDEWEB)

    Kress, B. [Universitaetsklinikum Heidelberg, Abt. Neuroradiologie (Germany); Abt. Neuroradiologie, Neurologische Klinik, Universitaetsklinik Heidelberg (Germany); Griesbeck, F. [Abt. Neurologie/Psychiatrie, Bundeswehrkrankenhaus Ulm (Germany); Stippich, C.; Sartor, K. [Abt. Neuroradiologie, Neurologische Klinik, Universitaetsklinik Heidelberg (Germany); Baehren, W. [Universitaetsklinikum Heidelberg, Abt. Neuroradiologie (Germany)

    2003-01-01

    Purpose: To compare in a single-blind study the reliability of quantitative measurements and subjective evaluations of contrast enhancement of the facial nerve in patients with idiopathic facial paralysis. Materials and Methods: Magnetic resonance images with a 0.7 mm slice thickness (surface coil) were obtained in patients with idiopathic facial paralysis before and after administration of Gd-DTPA, 0.1 mmol/kg. The five intratemporal segments of the facial nerve were quantitatively measured and subjectively assessed by five radiologists as to the degree of enhancement. The results were compared as to the reliability of both methods. Results: Using the quantitative measuring method, 175 measurements were calculated from a total of 350 regions of interest. At all 35 measured sites, the five quantitative measurements produced identical results. In contrast, the subjective assessment of the five radiologists arrived at a majority consensus in only 16 sites. A complete agreement was not reached for any measured site. Conclusion: The measured quantitative increase in signal intensity after administration of contrast medium is more reliable than subjective assessment. The quantitative method enables reproducible signal intensity measurements even for different window settings and can be easily and swiftly performed at the workstation. (orig.) [German] Untersuchungsziel: In einer einfach geblindeten Untersuchung sollte geprueft werden, wie hoch die Reliabilitaet der quantitativen Messung des Kontrastmittelanstieges im N. facialis bei idiopathischer Fazialisparese im Vergleich zur subjektiven Einschaetzung ist. Methodik: Bei 7 Patienten mit idiopathischer Fazialisparese wurde eine MRT in Duennschichttechnik (0,7 mm, nativ und nach Gabe von 0,1 mmol GdDTPA/kg) unter Verwendung einer Oberflaechenspule durchgefuehrt. 5 intratemporale Abschnitte des N. facialis wurden sowohl quantitativ als auch subjektiv durch 5 Radiologen beurteilt, und die Methoden wurden im Hinblick auf

  1. 集约经营雷竹林分结构特征%Structure characteristics of intensive managed Phyllostachys praecon stand

    Institute of Scientific and Technical Information of China (English)

    肖宋高; 陈明亮; 江雄波; 胡云; 张卓文

    2012-01-01

    以湖北省崇阳县雷竹林为研究对象,对集约经营雷竹林分结构及各器官生物量分配特征进行了调查与分析,结果表明:集约经营雷竹笋用林立竹在林地上分布均匀,调查的雷竹林分平均胸径为2.55cm,通过胸径计算得到的适宜经营密度约为15000株/hm2(1000株/667m2);林分中立竹处于年青状态,1年生、2年生、3年生及4年生、5年生立竹数依次为3000、4660、3880、460、20株/hm2,所占的百分率依次为24.59%、38.20%、31.80%、3.77%及1.60%;钩梢有利于雷竹林分抗雪压,虽然钩梢后立竹留盘数减少,冠幅减小,但平均每枝叶面积指数增大;生产中每年通过在林地上均匀保留健壮的笋体而形成新立竹,因而林木株数按径阶的分布不符合正态分布规律,出现向右偏态;农事活动使枝下高也发生变异;雷竹林各器官生物量大小依次为杆>竹蔸>竹鞭>叶>枝,钩梢使各器官生物量大小发生变化.%Research had been carried out into the structure and the biomass for different organs of Phyllostachys praecon stands located at Chongyang County, Hubei Province,which were intensive managed, the results showed that bamboo stems were uniform distributed in ground, the average DBH of plots studied was 2. 55 cm,the management density calculated according to the average DBH was 15 000 stems per hm2(1000 stems per 667 m2);all stands studied were very young and in good health, stems density for 1,2,3,4 and 5 a were 3 000 stems per hm2,4 660 stems per hm2,3 880 stems per hm2 ,460 stems per hm2and 20 stems per hm2 with 24. 59%,38. 20%,31. 80%,3. 77% and 1. 60%,respectively; for anti-snow pressure,although tip hooking made the stem shorted,branch round decreased and crown width dwindled,leaf area index increased. When harvesting bamboo shoots, big and strong shoots were kept uniform in a stand ground which would grow as new stems,so the distribution of DBH was not a normal one, but a

  2. MRI-based liver iron content determination at 3 T in regularly transfused patients by signal intensity ratio using an alternative analysis approach based on R{sub 2}* theory

    Energy Technology Data Exchange (ETDEWEB)

    Wunderlich, A.P. [Universitaetsklinikum Ulm (Germany). Section for Experimental Radiology; Cario, H. [Universitaetsklinik Ulm (Germany). Children' s Hospital; Bommer, M. [Alb-Fils-Clinics, Goeppingen (Germany). Hematology and Oncology Dept.; Beer, M.; Schmidt, S.A. [Universitaetsklinikum Ulm (Germany). Dept. for Diagnostic and Interventional Radiology; Juchems, M.S. [Klinikum Konstanz (Germany). Diagnostic and Interventional Radiology

    2016-09-15

    To evaluate the feasibility of addressing liver iron content (LIC) in regularly transfused patients by MR imaging at 3 T based on the signal intensity ratio (SIR). An innovative data analysis approach was developed for this purpose. 47 consecutive examinations of regularly transfused patients were included. In all cases, we expected high LIC levels. Patients were scanned with MRI at 3 T with multi-echo gradient echo sequences (GRE) at four different flip angles between 20 and 90 with echo times (TE) ranging from 0.9 to 9.8 ms. Spin-echo protocols were acquired to determine the LIC with a reference MRI method working at 1.5 T. 3 T GRE data were analyzed using the liver-to-muscle SIR. Since the method known for 1.5 T was not expected to be applicable for analyzing 3 T data, theoretic dependence of the SIR on the LIC was derived from the equation describing R{sub 2}* signal decay. Obtained SIR values were correlated to reference LIC to get a relation for calculating LIC from SIR quantities. LIC values and their uncertainties were determined from GRE data and correlated to LIC reference values. For two LIC thresholds, the diagnostic accuracy was determined. LIC was reliably determined from SIR in our patient cohort even for large LIC values. Median of LIC uncertainties was 10%, and the diagnostic accuracy was 0.92 and 0.91, respectively. Determination of even high LIC, resulting in small SIR values, is feasible at 3 T using appropriate SIR analysis.

  3. Microstructural characteristics of the hydroxyapatite and its influence in the Tl signal induced by gamma radiation; Caracteristicas microestructurales de la hidroxiapatita y su influencia en la senal Tl inducida por la radiacion gamma

    Energy Technology Data Exchange (ETDEWEB)

    Mendoza A, D.; Gonzalez M, P.R.; Hernandez A, M. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Estrada G, R. [Depto. de Fisica y Matematicas, Universidad Iberoamericana, Santa Fe, 01000 Mexico D.F. (Mexico); Rodriguez L, V. [Centro Universitario de Vinculacion, BUAP, Puebla (Mexico)

    2003-07-01

    The analysis carried out on different materials has shown that the quantity and type of dopants play an important role in the behaviour thermoluminescent signal induced by the ionizing radiation. More recent studies have also shown that the grain size influences strongly in the thermoluminescent signal. Plus still, the crystal growth habit and the crystalline degree have an important effect in the type and intensity thermoluminescent signal. In this sense, we present this work on the analysis of the thermoluminescent signal induced by the gamma radiation in the hydroxyapatite ceramic. Depending the growth habit, a variation of the peak temperature location, signal intensity and linearity range was observed; in particular cases a lineal relationship between glow curve and radiation dose was in the range from 2 to 1000 Gray. These results are complemented with a microstructural and crystalline degree analysis through scanning electron microscopy and X-ray Diffraction. The dose-response over the whole irradiation range opening up the possibility of employing this bio material as a dosimeter. (Author)

  4. Is there any correlation between model-based perfusion parameters and model-free parameters of time-signal intensity curve on dynamic contrast enhanced MRI in breast cancer patients?

    Energy Technology Data Exchange (ETDEWEB)

    Yi, Boram; Kang, Doo Kyoung; Kim, Tae Hee [Ajou University School of Medicine, Department of Radiology, Suwon, Gyeonggi-do (Korea, Republic of); Yoon, Dukyong [Ajou University School of Medicine, Department of Biomedical Informatics, Suwon (Korea, Republic of); Jung, Yong Sik; Kim, Ku Sang [Ajou University School of Medicine, Department of Surgery, Suwon (Korea, Republic of); Yim, Hyunee [Ajou University School of Medicine, Department of Pathology, Suwon (Korea, Republic of)

    2014-05-15

    To find out any correlation between dynamic contrast-enhanced (DCE) model-based parameters and model-free parameters, and evaluate correlations between perfusion parameters with histologic prognostic factors. Model-based parameters (Ktrans, Kep and Ve) of 102 invasive ductal carcinomas were obtained using DCE-MRI and post-processing software. Correlations between model-based and model-free parameters and between perfusion parameters and histologic prognostic factors were analysed. Mean Kep was significantly higher in cancers showing initial rapid enhancement (P = 0.002) and a delayed washout pattern (P = 0.001). Ve was significantly lower in cancers showing a delayed washout pattern (P = 0.015). Kep significantly correlated with time to peak enhancement (TTP) (ρ = -0.33, P < 0.001) and washout slope (ρ = 0.39, P = 0.002). Ve was significantly correlated with TTP (ρ = 0.33, P = 0.002). Mean Kep was higher in tumours with high nuclear grade (P = 0.017). Mean Ve was lower in tumours with high histologic grade (P = 0.005) and in tumours with negative oestrogen receptor status (P = 0.047). TTP was shorter in tumours with negative oestrogen receptor status (P = 0.037). We could acquire general information about the tumour vascular physiology, interstitial space volume and pathologic prognostic factors by analyzing time-signal intensity curve without a complicated acquisition process for the model-based parameters. (orig.)

  5. Differentiation of mass-forming focal pancreatitis from pancreatic ductal adenocarcinoma: value of characterizing dynamic enhancement patterns on contrast-enhanced MR images by adding signal intensity color mapping

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Mimi [Hanyang University College of Medicine, Department of Radiology, Hanyang Medical Center, Seoul (Korea, Republic of); Jang, Kyung Mi [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Sungkyunkwan University School of Medicine, Department of Radiology and Center for Imaging Science, Samsung Medical Center, Seoul (Korea, Republic of); Kim, Jae-Hun; Jeong, Woo Kyoung; Kim, Seong Hyun; Kang, Tae Wook; Kim, Young Kon; Cha, Dong Ik [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea, Republic of); Kim, Kyunga [Samsung Medical Center, Biostatics and Clinical Epidemiology Center, Research Institute for Future Medicine, Seoul (Korea, Republic of)

    2017-04-15

    To evaluate the value of dynamic enhancement patterns on contrast-enhanced MR images by adding signal intensity colour mapping (SICM) to differentiate mass-forming focal pancreatitis (MFFP) from pancreatic ductal adenocarcinoma (PDAC). Forty-one clinicopathologically proven MFFPs and 144 surgically confirmed PDACs were enrolled. Laboratory and MR imaging parameters were used to differentiate MFFP from PDAC. In particular, enhancement patterns on MR images adding SICM were evaluated. By using classification tree analysis (CTA), we determined the predictors for the differentiation of MFFP from PDAC. In the CTA, with all parameters except enhancement pattern on SICM images, ductal obstruction grade and T1 hypointensity grade of the pancreatic lesion were the first and second splitting predictor for differentiation of MFFP from PDAC, in order. By adding an enhancement pattern on the SICM images to CTA, the enhancement pattern was the only splitting predictor to differentiate MFFP from PDAC. The CTA model including enhancement pattern on SICM images has sensitivity of 78.0 %, specificity of 99.3 %, and accuracy of 94.6 % for differentiating MFFP from PDAC. The characterization of enhancement pattern for pancreatic lesions on contrast-enhanced MR images adding SICM would be helpful to differentiate MFFP from PDAC. (orig.)

  6. Increasing signal intensity within the dentate nucleus and globus pallidus on unenhanced T1W magnetic resonance images in patients with relapsing-remitting multiple sclerosis: correlation with cumulative dose of a macrocyclic gadolinium-based contrast agent, gadobutrol

    Energy Technology Data Exchange (ETDEWEB)

    Stojanov, Dragan A. [University of Nis, Faculty of Medicine, Nis (Serbia); Clinical Center Nis, Center for Radiology, Nis (Serbia); Aracki-Trenkic, Aleksandra [Clinical Center Nis, Center for Radiology, Nis (Serbia); Vojinovic, Slobodan; Ljubisavljevic, Srdjan [University of Nis, Faculty of Medicine, Nis (Serbia); Clinical Center Nis, Clinic for Neurology, Nis (Serbia); Benedeto-Stojanov, Daniela [University of Nis, Faculty of Medicine, Nis (Serbia)

    2016-03-15

    To evaluate correlation between cumulative dose of gadobutrol and signal intensity (SI) within dentate nucleus and globus pallidus on unenhanced T1-weighted images in patients with relapsing-remitting multiple sclerosis (RRMS). Dentate nucleus-to-pons and globus pallidus-to-thalamus SI ratios, and renal and liver functions, were evaluated after multiple intravenous administrations of 0.1 mmol/kg gadobutrol at 27, 96-98, and 168 weeks. We compared SI ratios based on the number of administrations, total amount of gadobutrol administered, and time between injections. Globus pallidus-to-thalamus (p = 0.025) and dentate nucleus-to-pons (p < 0.001) SI ratios increased after multiple gadobutrol administrations, correlated with the number of administrations (ρ = 0.263, p = 0.046, respectively) and depended on the length of administration (p = 0.017, p = 0.037, respectively). Patients receiving gadobutrol at 27 weeks showed the greatest increase in both SI ratios (p = 0.006; p = 0.014, respectively, versus 96-98 weeks). GGT increased at the end of the study (p = 0.004). In patients with RRMS, SI within the dentate nucleus and globus pallidus increased on unenhanced T1-weighted images after multiple gadobutrol injections. Administration of the same total amount of gadobutrol over a shorter period caused greater SI increase. (orig.)

  7. Signal intensity change of the labyrinth in patients with surgically confirmed or radiologically diagnosed vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery MR imaging at 3 T

    Energy Technology Data Exchange (ETDEWEB)

    Lee, In Ho; Kim, Hyung-Jin; Kim, Eunhee; Moon, Jung Won; Kim, Sung Tae; Kim, Keon Ha; Jeon, Pyoung; Byun, Hong Sik [Sungkyunkwan University School of Medicine, Department of Radiology, Samsung Medical Center, Seoul (Korea); Chung, Won Ho [Sungkyunkwan University School of Medicine, Department of Otorhinolaryngology-Head and Neck Surgery, Samsung Medical Center, Seoul (Korea)

    2010-04-15

    The purpose of this study was to evaluate the signal intensity (SI) change of the labyrinth in patients with vestibular schwannoma on isotropic 3D fluid-attenuated inversion recovery (FLAIR) imaging at 3 T. Thirty-four patients with surgically confirmed or radiologically diagnosed vestibular schwannoma were included in this study. Retrospectively, we visually and quantitatively compared the SIs of the cochlea and vestibule on the affected side with those on the unaffected side. We also investigated whether there was correlation between the SI ratios (SIRs) of the labyrinth and the audiometric findings. On 3D FLAIR images, the SI of the cochlea and vestibule on the affected side was significantly increased in 97% (33/34) and 91% (31/34), respectively. While the SI of the cochlea was diffusely increased, that of the vestibule was only partially increased. Quantitative study also revealed statistically significantly higher SIRs of the cochlea (0.99 {+-} 0.29) and vestibule (0.73 {+-} 0.31) on the affected side, compared with the cochlea (0.47 {+-} 0.20) and vestibule (0.19 {+-} 0.10) on the unaffected side. There was no significant correlation of the SIRs of the labyrinth with the degree of hearing loss. In patients with vestibular schwannoma, isotropic 3D FLAIR imaging is a useful method for the evaluation of the SI changes of the labyrinth. (orig.)

  8. [Intensive medicine in Spain].

    Science.gov (United States)

    2011-03-01

    Intensive care medicine is a medical specialty that was officially established in our country in 1978, with a 5-year training program including two years of common core training followed by three years of specific training in an intensive care unit accredited for training. During this 32-year period, intensive care medicine has carried out an intense and varied activity, which has allowed its positioning as an attractive and with future specialty in the hospital setting. This document summarizes the history of the specialty, its current situation, the key role played in the programs of organ donation and transplantation of the National Transplant Organization (after more than 20 years of mutual collaboration), its training activities with the development of the National Plan of Cardiopulmonary Resuscitation, with a trajectory of more than 25 years, its interest in providing care based on quality and safety programs for the severely ill patient. It also describes the development of reference registries due to the need for reliable data on the care process for the most prevalent diseases, such as ischemic heart disease or ICU-acquired infections, based on long-term experience (more than 15 years), which results in the availability of epidemiological information and characteristics of care that may affect the practical patient's care. Moreover, features of its scientific society (SEMICYUC) are reported, an organization that agglutinates the interests of more than 280 ICUs and more than 2700 intensivists, with reference to the journal Medicina Intensiva, the official journal of the society and the Panamerican and Iberian Federation of Critical Medicine and Intensive Care Societies. Medicina Intensiva is indexed in the Thompson Reuters products of Science Citation Index Expanded (Scisearch(®)) and Journal Citation Reports, Science Edition. The important contribution of the Spanish intensive care medicine to the scientific community is also analyzed, and in relation to

  9. 不同光强下染料敏化太阳能电池输出特性仿真%The simulation of dye-sensitized solar cells' output characteristic in different light intensity

    Institute of Scientific and Technical Information of China (English)

    殷克剑; 胡志强; 张延大; 秦颖; 杨冬雪; 黄德锋; 熊小伟

    2013-01-01

    According to the equivalent circuit of dye-sensitized solar cells(DSSC) and its mathematical model, the simulation model was established in the environment of Matlab/simulink and the work current of DSSC was calculated by the method of Newton's iterative. The DSSC with TiO2 film as light anode was prepared and the effect of different light intensity on the performance of DSSC was investigated. The results indicated that the output characteristics of DSSC are affected by light intensity obviously.%以染料敏化太阳能电池(DSSC)的等效电路图及数学模型为依据,利用牛顿迭代法计算DSSC的工作电流,在Matlab/Simulink仿真环境下建立了仿真模型.制备并测试了以TiO2薄膜为光阳极的DSSC.使用估算参数的方法对测得的数据进行拟合.研究了不同光照强度对DSSC输出特性的影响.仿真结果表明,DSSC的输出特性受光照强度影响很大.

  10. Intensive mobilities:

    DEFF Research Database (Denmark)

    Vannini, Phillip; Bissell, David; Jensen, Ole B.

    This paper explores the intensities of long distance commuting journeys as a way of exploring how bodily sensibilities are being changed by the mobilities that they undertake. The context of this paper is that many people are travelling further to work than ever before owing to a variety of facto....... By exploring how experiences of long-distance workers become constituted by a range of different material forces enables us to more sensitively consider the practical, technical, and political implications of this increasingly prevalent yet underexplored regime of work....... which relate to transport, housing and employment. Yet we argue that the experiential dimensions of long distance m