Higher Relative Changes Research Articles

Changes of Circulating Endothelial Cells and Microparticles after Conventional Chemotherapy in Patients with Extensive Small-Cell Lung Cancer: Relevance to Prognosis and Treatment Response

Objectives: Tumor angiogenesis is controlled by inhibitors and angiogenic factors. However, circulating endothelial cells (CECs) and microparticles (MPs) may be related to tumor angiogenesis in malignant tumors. We therefore investigated the significance of CECs and MPs variation for the prediction of treatment efficacy andprognosis in patients with extensive small-cell lung cancer (SCLC). Materials and methods: Isolation and quantification of CECs from the whole-blood was performed using immune magnetic separation (IMS) technique, while flow cytometry measurement (FCM) was used for enumerating MPs in plasma samples.Results: Twenty-six patients were included in this prospective study. The relative change in CEC and MP counts after treatment, correctly identified treatment response in 22/26 patients (84.6%) and 17/23 patients (73.9%) respectively. The difference in themedian duration of time to progression (TTP) between patient with high relative changes and those with low relative changes in CEC and MP values was not statistically significant (p=0.39 and p=0.2, respectively). By contrast, the increase in CEC and MP levels after chemotherapy tended to be inversely correlated with longer TTP duration (r²=0.111 and r²=0.171, respectively). However, onlym decreased MP values after chemotherapy have the trend to be correlated with longer TTP duration (r²=0.167).Conclusion: The relative change in CEC and MP values after treatment seems to be a useful biomarker for the evaluation of treatment response in patients with extensive SCLC. Moreover, this relative change in both biomarkers might be considered as a prognostic tool in SCLC.

Changeability of soil erosion variables in small field plots from different rainfall durations with constant intensity

Rainfall duration is among the most effective characteristics of erosivity factor on runoff, splash and soil loss, especially when a rainfall duration is selected for laboratory or field plot studies. Selecting the appropriate rainfall duration particularly in laboratory studies (because of higher relative changes in lower durations), may lead to decrease the errors in the studied treatments. The rainfall duration must be well considered before any experiments exploring the effect of rainfall as one of the main factors. Therefore, the present study was conducted in field plots with area of 1 m2 located in an 18% slope, loamy–clay, under rainfall simulation with the intensity of 40 mm h−1. Total and net splashes, sediment concentration, soil loss, sheet erosion and sediment delivery ratio were measured and evaluated in 6 levels of rainfall duration (5, 10, 15, 20, 25 and 30 min), with 3 replications. The results showed that, although the runoff volume increased with increasing rainfall duration generally, there was insufficient capacity for runoff to transport the considerable amounts of the splashed and eroded soil to the plot outlet. The translocation of soil surface particles and sheet erosion were therefore increased due to more duration of rainfall and runoff, while a significant portion of the eroded soil, even after 30 min rainfall duration was not transported to the plot outlet. Based on the results, the sensitivity and efficiency of Generalized Linear Model (GLM) and Generalized Additive Model (GAM) in the evaluation of the differences between hydrological responses in various rainfall durations were different. According to the results, there was a change in the average ratio of sediment delivery in studied treatments from 0.41 to 13.03% for 5 and 30 min respectively. The results clearly showed that the duration corresponding to the intensity is the best choice to adopt soil erosion studies at plot and experimental conditions.

EVALUATION EFFICIENCY OF SULPHUR FERTILIZER IN CALCAREOUS SOIL AMENDED BY COMPOST

A pots experiment was carried out at greenhouse of Soil Sci., Dept., Fac., of Agric., Menoufia Univ., Egypt to study the effect of individual and combined applications of compost and S as soil amendments on calcareous sandy soil properties and its content of available macro and micronutrients barley plants (Hordeum Vulgare L.)growth and its content of macro and micronutrient and agronomical efficiency (AE) of the tested soil amendments. Compost was added at rates of 0, 1 and 2 %, where S was added as elemental S at rates of 0, 200, 300 and 400 mg/kg. The dry matter yield of barley plants harvested after 70 days of planting and its content of macro and micronutrients were determined. Also, chemical properties of the tested soil and its content of available macro and micronutrients after planting harvesting were determined. Increasing application rates of compost and S individually and together resulted in a decrease of calcareous soil pH, EC (dS m-1) and its content (%) of CaCO3, while were associated by an increase soil OM (%), CEC (meq/100 g) and its content (mg/kg) of available N, P, K, Ca, Mg, S, Fe, Zn, Mn and Cu. The high relative changes “RC” (%) of the studied soil properties were associated the combined treatments of compost and S especially at high application rates. Dry matter yield of barley plants and its content of N, P, K, Ca, Mg, S, Fe, Zn, Mn and Cu were increase with the increases of added compost and S individually and together. Agronomical efficiency (AE) of both compost and S under calcareous sandy soil conditions were increased in their combined application treatments. So, these results concluded that, to improve the properties of calcareous sandy soil and increased its fertility and productivity must be treated by compost and S together.

Fabrication and gas sensing behavior of poly(3,4-ethylenedioxythiophene) coated polypropylene fiber with engineered interface

Conductive composite fibers were successfully fabricated by coating poly(3,4-ethylenedioxythiophene) (PEDOT) layers on the surface of polypropylene-graft-poly(acrylic acid) (PP-g-PAA) fibers through in situ chemical oxidative polymerization. It was found that the adhesion between the conductive PEDOT layers and the modified PP fiber substrates was significantly enhanced due to the electrostatic attractions between PEDOT chains and carboxylic groups of grafted PAA. In this study, we investigated the influence of the 3,4-ethylenedioxythiophene (EDOT) concentration and the oxidant species on the electrical conductivity of the composite fibers, and the result show that the maximum conductivities of PP-g-PAA/PEDOT composite fibers prepared with FeCl3 and iron(III) p-toluenesulfonate (FepTS) as oxidants reached 0.069S/cm and 10.09S/cm, respectively. The composite fibers were applied as a sensor for HCl and NH3 gas detection and exhibited a rapid and reversible response. The influence of the oxidant species on the sensing properties for HCl and NH3 gas detection is further discussed, and some features such as fast response time (less than 2s) and high relative resistance changes (63% for HCl and 110% for NH3 gas) were achieved.

Abstract 11387: Examining Mortality Based on Changes in Peak Oxygen Consumption After Cardiac Rehabilitation

Introduction: Cardiac rehabilitation (CR) in stable coronary heart disease (CHD) has been shown to improve mortality commensurate with levels of improvement in cardiorespiratory fitness (CRF). We examine here if relative improvement is as important as absolute improvement on mortality. Hypothesis: We assessed the hypothesis that effects of absolute and relative changes in fitness, on mortality in a cardiac rehab population are different. Methods: 890 subjects with stable CHD referred for CR were stratified according to baseline peak oxygen consumption (VO2) and post-CR improvement in VO2 (absolute group divided at 2.5 cc/kg/min, relative group divided at 20%) as measured during maximal cardiopulmonary exercise testing. Results: After adjusting for age, gender, left ventricular ejection fraction, baseline VO2, and body mass index, participants with higher absolute improvement had a twofold lower mortality (HR 0.56, p<0.001), whereas high relative improvement had no significant mortality effect. When post-rehab VO2 was used as a covariate, VO2 improvement was no longer associated with changes in mortality (HR 0.82, p = 0.37). High relative improvement without high absolute improvement was independently associated with increased mortality (HR 2.63, p<0.001, Figure 1) and lower baseline fitness (p < 0.001) than groups with high absolute improvement. Conclusions: In patients with CHD, absolute fitness after CR is the primary modulator of mortality, high absolute changes appear to be related to mortality benefits within the scope of increasing post-CR absolute CRF. This explains why high relative changes without associated absolute improvement reflects an especially low baseline CRF and high associated mortality. These results indicate that setting absolute targets for exercise capacity during CR can improve outcomes.

BIOMETRIC SCORE FUSION

Multimodal biometric innovation in light of unique mark and finger knuckle has pulled in footing among scientists as of late. Despite the fact that Uni-modular framework offers many focal points, it has certain intrinsic shortcomings which deny it of the appeal. Uni-modular unique finger impression biometric frameworks performed singular acknowledgment in light of a particular wellspring of biometric data. However the match score esteem must be enhanced by working with low quality little closer view zone biometric pictures. In fact, the confirmation forms delivered by Finger Knuckle Print (FKP) brings about higher relative changes. The distortions between FKP pictures of same finger are of higher extent. The unimodal biometric check framework frequently gets influenced after accomplishing higher match score esteem. Besides, bimodal check framework does not accomplish higher security level which prompts to lesser combination score esteem. To diminish relative change on multimodal biometric framework, NonFracture based Fingerprint and Finger-Knuckle print Biometric Score Fusion (NFF-BSF) component is proposed in this paper. At first, particular estimation of match score is measured utilizing multimodal fitting coarse grained dissemination work. Multimodal fitting coarse grained dissemination capacity is utilized to work with low quality petite frontal area biometric pictures that accomplish high fitting score on the test and preparing biometric pictures. Also, Non-Fracture misshapening handling is completed in NFF-BSF instrument to diminish the adjustment fit as a fiddle of protest by utilizing bend length on biometric picture surfaces. At last, a coordinating technique in NFF-BSF instrument is utilized to decrease the relative changes. Thus, the relative changes on multimodal biometric framework expands the match score combination esteem. Investigation is directed on variables, for example, certifiable acknowledgment rate, coordinating score combination level and blunder rate on multimodal coordinating

AMPD1 Polymorphism and Response to Regadenoson

AMPD1 c.34C > T (rs17602729) polymorphism results in AMPD1 deficiency. We examined the association of AMPD1 deficiency and variability of hemodynamic response to regadenoson. Genotyping for c.34C>T was performed in 267 patients undergoing regadenoson cardiac stress testing. Carriers of c.34C >T variant exhibited higher relative changes in systolic blood pressure (SBP) compared with wild-type subjects ([%] SBP change to peak: 12 ± 25 vs 5 ± 13%; p = 0.01) ([%] SBP change to nadir: -3 ± 15 vs -7 ± 11%; p = 0.04). Change in heart rate was similar between groups, but side effects were more common in carriers of the variant (+LR = 4.2; p = 0.04). AMPD1 deficiency may be involved in the modulation of regadenoson's systemic effects.

A highly tunable and fully biocompatible silk nanoplasmonic optical sensor.

Novel concepts for manipulating plasmonic resonances and the biocompatibility of plasmonic devices offer great potential in versatile applications involving real-time and in vivo monitoring of analytes with high sensitivity in biomedical and biological research. Here we report a biocompatible and highly tunable plasmonic bio/chemical sensor consisting of a natural silk protein and a gold nanostructure. Our silk plasmonic absorber sensor (SPAS) takes advantage of the strong local field enhancement in the metal-insulator-metal resonator in which silk protein is used as an insulating spacer and substrate. The silk insulating spacer has hydrogel properties and therefore exhibits a controllable swelling when exposed to water-alcohol mixtures. We experimentally and numerically show that drastic spectral shifts in reflectance minima arise from the changing physical volume and refractive index of the silk spacer during swelling. Furthermore, we apply this SPAS device as a glucose sensor with a very high sensitivity of 1200 nm/RIU (refractive index units) and high relative intensity change.

Characterizing the Dynamic Response of a Chassis Frame in a Heavy-Duty Dump Vehicle Based on an Improved Stochastic System Identification

This paper presents an online method for the assessment of the dynamic performance of the chassis frame in a heavy-duty dump truck based on a novel stochastic subspace identification (SSI) method. It introduces the use of an average correlation signal as the input data to conventional SSI methods in order to reduce the noisy and nonstationary contents in the vibration signals from the frame, allowing accurate modal properties to be attained for realistically assessing the dynamic behaviour of the frame when the vehicle travels on both bumped and unpaved roads under different operating conditions. The modal results show that the modal properties obtained online are significantly different from the offline ones in that the identifiable modes are less because of the integration of different vehicle systems onto the frame. Moreover, the modal shapes between 7 Hz and 40 Hz clearly indicate the weak section of the structure where earlier fatigues and unsafe operations may occur due to the high relative changes in the modal shapes. In addition, the loaded operations show more modes which cause high deformation on the weak section. These results have verified the performance of the proposed SSI method and provide reliable references for optimizing the construction of the frame.

High sensitivity to humidity of an element based on a carbon-nanotube bundle

The results of development and studies of humidity-sensitive elements based on a carbon-nanotube bundle are presented. It has been demonstrated that arrays of nanotubes grown by the low-temperature plasma-chemical method on planar silicon structures have exceptional sensitivity to humidity. The ratio of the structure resistance in dry and humid states is more than 105-fold. Such a high relative resistance change is caused by the character of changes in conductivity of the charge carriers between individual tubes of the bundle upon adsorption of water molecules.

Changes in glacierisation, climate and runoff in the second half of the 20th century in the Naryn basin, Central Asia

Glaciers are significant fresh water storages in Central Asian high mountains and are considered to substantially contribute to the summer runoff of Central Asian Rivers. We present a comprehensive study of the glacier area changes in the Naryn catchment located in the Tien Shan Mountains. The catchment with a size of 55,944km2 is a major tributary of the Syrdarya River which is heavily used for water supply and irrigation. We analysed the glacier retreat based on Landsat MSS, TM and ETM+imagery for the mid-1970s, late 1990s and mid-2000s and based on a SPOT scene for 2007. Our results show a decreasing glacierisation within the catchment, shrinking from 1210±30km2 (2.2% glacierisation) in the 1970s to 1019±25km2 (1.8% glacierisation) in the late 1990s and further down to 926±23km2 (1.7% glacierisation) in the mid-2000s, corresponding to an area loss of 23% in total. The analysis reveals spatially heterogeneous area loss within the catchment. This can be associated with different hypsometries, size distributions, aspects and presences of debris cover. Small glaciers (with an area<1km2) suffered from a strong area loss within the 30-years investigation period.Trends in air temperature, precipitation and positive degree days (PDD) at climate stations suggest that the glacier retreat is likely to be driven by the increasing summer (April–September) temperature, rather than changes in precipitation: In the period from 1960 to 2007, both summer air temperature and PDDs increased significantly at a rate of 0.19°C/decade and 3.9°C/decade respectively, whilst for precipitation no consistent trends were detected. However, rigorous attribution of changes is complicated by the variable glacier response times. In the two headwater sub-catchments of the Naryn basin, Small and Big Naryn, positive trends in spring and autumn discharge were detected and are likely to be associated with the enhanced snow and glacier melt driven by increasing temperatures in those seasons. However, no discharge trends in August – the month with the largest expected glacier contribution – were detected. The strong, significantly positive trends in winter and early spring runoff are associated with strongly increasing winter temperatures and number of days with maximum daily temperature above the freezing point causing snow melt. Hence, increasing glacier area reduction can be explained by the prolongation of the melting season reducing accumulation rather than by increasing annual mean temperatures. Despite the high relative changes, the absolute increase in winter discharge is very small.

Integration of urban growth modelling products with image-based urban change analysis

Urban change detection using remotely sensed data has been extensively studied. One current application of detection products is the formulation of calibration data for urban change prediction models. As multi-temporal scenes become available and urban growth prediction models increase in popularity and accuracy, it is natural to envisage a bi-directional relationship where, in addition to detection products assisting prediction models, the prediction information acts as ancillary input to enhance spectral-based change detection products. This closed feedback loop has the potential to significantly increase the accuracy of both detection and prediction efforts. Consequently, our objective is to evaluate the integration of prediction information with spectral data for urban change monitoring. A case study was carried out in the Denver, Colorado metropolitan area. Probabilities of urban change generated from two existing urban prediction models (based on decision trees and logistic regression) are combined as additional information content with a Landsat Thematic Mapper (TM) scene. Detailed assessments at the pixel and block scales are implemented to evaluate urban change classification accuracy using different input data and training sample sizes. Results show that in pixel-based assessments, the fusion of decision tree change probabilities and TM spectral bands with sufficient training samples leads to improvements. In terms of overall accuracies, the improvement is 2.0–2.4%, from 87.3% (spectral-only model) and 87.7% (prediction probability model) to 89.7% for the fused model. Similarly, the corresponding kappa coefficients show increases of 0.07–0.08, from 0.60 for the spectral model and 0.61 for the urban prediction model to 0.68 for the fused model. Accuracies aggregated at the block scale present an approximate 2.1–4.3% increase when the fusion-based model is employed compared with the exclusive use of either spectral or prediction probability data, namely 87.6% (fused) vs 83.4% (spectral) and 85.7% (prediction). It is also important to state that the standard deviation of accuracies between blocks is significantly reduced by more than 3% (11.5% vs 14.9% and 14.7%), suggesting higher consistency in classification performance. This is a desirable attribute for subsequent use of these products, for example by the urban planning community. Statistical tests at the block scale also demonstrate that such improvements are significant. It is also observed that to receive the integration benefits, the remote sensing classifier needs a large but reasonable training data set size, while the prediction model should be based on advanced modelling methods. Further assessments on block accuracy with respect to urbanization conditions (i.e. urban presence and change sizes) indicate the ability of the fusion to address spectral limitations, especially in blocks with high relative change. These initial results encourage the expansion of spectral/prediction data fusion to other sites, modelling techniques, and input data.

Microwave radiometry: a new non-invasive method for the detection of vulnerable plaque.

Atherosclerosis and its consequences are the most rapidly growing vascular pathology, with myocardial infarction and ischemic cerebrovascular accident to remain a major cause of premature morbidity and death. In order to detect the morphological and functional characteristics of the vulnerable plaques, new imaging modalities have been developed. Intravascular thermography (IVT) is an invasive method, which provides information on the identification of the high-risk atheromatic plaques in coronary arteries. However, the invasive character of IVT excludes the method from primary prevention. Microwave radiometry (MR) is a new non-invasive method, which detects with high accuracy relative changes of temperature in human tissues whereas this thermal heterogeneity is indicative of inflammatory atherosclerotic plaque. Both experimental and clinical studies have proved the effectiveness of MR in detecting vulnerable plaque whereas recent studies have also revealed its association with plaque neoangiogenesis as assessed by contrast enhanced carotid ultrasound (CEUS).

Dating High Arctic Holocene relative sea level changes using juvenile articulated marine shells in raised beaches

High Arctic raised beaches provide evidence for changes in relative sea-level (RSL), sea-ice extent, storminess, and variations in sediment supply. In many High Arctic areas, driftwood and whale bone are usually the preferred targets for radiocarbon dating, with marine shells a third choice because of their often large age and height uncertainties with respect to former sea level. Here we detail a new approach to sampling marine shells that reduces these problems by targeting juvenile, articulated specimens of Astarte borealis that are washed onto the beach under storm conditions and become incorporated into the beach crest. Radiocarbon dates from articulated valves of A. borealis from eight raised beaches from Billefjorden, Svalbard, provide a chronology for Holocene beach ridge formation and RSL change that compares favourably to the most precise records developed from elsewhere in Svalbard using driftwood or whale bone. We demonstrate the value of this new approach by comparing our record with previously published RSL data from eastern Svalbard to test different models of Late Weichselian ice load in this region. We find support for a major ice dome centred south and east of Kong Karls Land but no evidence for a significant ice dome located over easternmost Spitsbergen or southern Hinlopen Strait as proposed from recent marine geophysical survey. The approach is potentially applicable elsewhere in Svalbard and the High Arctic to address questions of RSL change and beach ridge chronology, and hence wider questions regarding palaeoclimate and ice load history.

Multi-wall carbon nanotube gas sensors modified with amino-group to detect low concentration of formaldehyde

Gas sensors with multi-wall carbon nanotubes (MWCNTs) modified with amino-groups on interdigitated electrodes (IDE) were fabricated to detect low concentration of formaldehyde at room temperature. Effects of content of amino groups on sensing responses against various interfering circumstances and low concentration of formaldehyde were investigated. The sensor behaved high relative resistance changes to formaldehyde and lower response to interfering gases such as acetone, carbon dioxide, ammonia, toluene and ethanol. When the concentration of formaldehyde was 20ppb, the relative resistance changes of the sensor modified with 18.19% amino-group reached 1.73%. The sensor displayed high chemical selectivity, fast response and good reproducibility to low concentration of formaldehyde, which was attributed to the properties of MWNTs and the interaction between the surface of MWCNTs and amino-group.

Polyurethane-foam midsoles in running shoes - impact energy and damping

Most running shoe midsoles are made of ethylene vinyl acetate (EVA) foam although excellent mechanical long-term properties of polyurethane (PU) foam are generally known. The aim of this study was to investigate whether PU foam is applicable as midsole material regarding damping properties. Short-term and long-term mechanical tests were conducted for running shoes with midsoles of either PU or EVA foam using the Hydraulic Impact Test. The results of the short-term testing show that PU midsoles can be adjusted to a wide range of damping properties while EVA midsoles attained good average values. In long-term testing, however, the EVA foams exhibited higher relative changes of damping parameters than the PU materials, which confirms the durability and ageing resistance of PU.

Plasma angiogenic markers in patients with metastatic breast cancer treated with weekly docetaxel.

e21004 Background: The aim of the study was to evaluate angiogenic plasma markers in patients with metastatic breast cancer (MBC) treated with first-line weekly docetaxel (D), considered to be standard treatment at the time of the design of the study. Methods: Females with MBC were treated with weekly D 35 mg/m2 ± trastuzumab. Plasma levels of HER2 extracellular domain (HER2-ECD), nitric oxide (NO), interleukin-8, and VEGF-A were measured by ELISA before and after the treatment, as well as in 38 healthy female controls. Prognostic and predictive significance of the pre-treatment values and their relative change with treatment were tested by Cox-regression analysis. Results: Between February 2006 and January 2008, 159 patients were treated. 61 patients (38%) responded (CR = 5%, PR = 33%) and 52 (33%) had stable disease. 37 patients received trastuzumab. Median follow-up was 33 months (2.8-45.0), median PFS 8.8 months (95%CI: 7.2-10.3) and median survival 27.7 months (95%CI: 24.7-30.6). HER2-ECD was the only plasma marker that decreased significantly with treatment (p < 0.001), from 2.08 ng/mL (range 0.2- 13.12) to 1.4 ng/mL (range 0.1-12.72). Normal controls had significantly higher NO levels than that of MBC patients before treatment (282.5 vs 199 umol/L, respectively; p = 0.006), whereas HER2-ECD levels were marginally lower (1.76 vs 2.08 ng/mL, respectively; p = 0.054). High pretreatment HER2-ECD levels were of adverse prognostic significance for survival and PFS (p = 0.033 and p = 0.046, respectively) in patients not treated with trastuzumab. High pretreatment NO levels were also of adverse prognostic value (p < 0.001 for survival, p = 0.004 for PFS), as were high pre-treatment IL8 values (p = 0.048 for survival). Plasma VEGF-A did not appear to have prognostic value. High NO relative change was associated with better survival (p = 0.003), in contrast patients with high IL8 relative change were found to have a worse PFS (p = 0.017). Responders had a smaller relative change of IL8 (p = 0.038) than non- responders. Conclusions: HER2-ECD, NO and IL8 plasma levels appear to be of prognostic value for survival in patients with MBC treated with weekly docetaxel. Tumor angiogenic markers will also be examined by PCR in these patients. No significant financial relationships to disclose.

Sequences in the Sikanni Formation in the frontier Liard Basin of northwestern Canada—evidence for high frequency late Albian relative sea-level changes

The frontier Liard Basin is a relatively unexplored basin in northeastern British Columbia, southwestern Northwest Territories and southeastern Yukon Territory. Although it preserves a thick Cretaceous sedimentary succession, the relationships of these strata to those to the south in the Western Canada Sedimentary Basin (WCSB) are poorly understood. Outcrop sedimentary analysis along with foraminiferal micropaleontology and Rock-Eval pyrolysis are used to investigate the relative sea level and palaeoenvironmental changes that accompanied deposition of the upper Albian Sikanni Formation. Analysis of proximal and distal facies from three outcrops of the Sikanni Formation within the Liard Basin indicates that four sequences can be identified in offshore, wave-dominated shoreline, prodeltaic, delta front and delta plain litho- and biofacies. The identification of 10 5 yr cyclicity relative sea level changes that punctuated Sikanni deposition is supported by the presence of chert pebble lag deposits at surfaces interpreted as sequence boundaries. These sequences are regionally correlative in outcrops and well logs of the Sikanni Formation and indicate a previously unrecognized cyclicity in the upper Albian of the WCSB. Among the two causal mechanisms considered to have possibly driven the cycles, high frequency changes in flexural loading is probably responsible for the cyclicity observed, as evidence of basin-wide relative sea level changes necessary to support a eustatic interpretation is lacking in the late Albian of the WCSB.

Stability monitoring of ultrashort laser pulses using single-mode fibers

It is well known that propagation in an optical fiber alters the spectrum of ultrashort pulses due to the nonlinear interaction of the pulse with the fiber. The spectrum of the pulse as it emerges from the fiber depends on the input pulse parameters as well as the fiber parameters. We show by numerical analysis how this effect can provide a novel method to monitor with high sensitivity small relative changes in pulse characteristics of an ultrashort laser.

Magnetic Resonance Perfusion Tracks 133 Xe Cerebral Blood Flow Changes After Carotid Stenting

To compare magnetic resonance (MR) perfusion to gold-standard cerebral blood flow (CBF) determined by intra-arterial (133)Xe washout method. Eight patients with high-grade carotid stenoses underwent bolus-tracking MR perfusion and intra-arterial (133)Xe washout before and after carotid stenting. MR perfusion was compared with 133Xe-CBF values using Pearson linear correlation analysis. We observed a mean 37+/-38% increase in 133Xe-CBF and a mean 19+/-27% increase in relative CBF (rCBF) by MR perfusion immediately after stent placement. Relative (percent) changes in MR-rCBF showed a close and linear correlation to those seen in 133Xe-CBF (r=0.91; R2=0.84; P=0.002). There was a trend for MR perfusion to underestimate change in CBF at higher relative changes in flow. Bolus-tracking MR perfusion correlates with 133Xe-CBF in estimating postprocedural increases in blood flow but may underestimate the magnitude of the change with higher relative changes.