bluuebunny/crossref_metadata_2025_split huggingface dataset:
Diagnostic value of the flow profile in the distal descending aorta by phase‐contrast magnetic resonance for predicting severe coarctation of the aorta
Authors: Muzzarelli Stefano , Ordovas Karen Gomes , Hope Michael D. , Meadows Jeffery J. , Higgins Charles B. , Meadows Alison Knauth 
Published: May 2011

AbstractPurpose:To compare aortic flow profiles at the level of the proximal descending (PDAo) and distal descending aorta (DDAo) in patients investigated for coarctation of the aorta (CoA), and compare their respective diagnostic value for predicting severe CoA. Diastolic flow decay in the PDAo predicts severe CoA, but flow measurements at this level are limited by flow turbulence, aliasing, and stent‐related artifacts.Materials and Methods:We studied 49 patients evaluated for CoA with phase contrast magnetic resonance imaging (PC‐MRI). Parameters of diastolic flow decay in the PDAo and DDAo were compared. Their respective diagnostic value was compared with the standard reference of transcatheter peak gradient ≥20 mmHg.Results:Flow measurement in the PDAo required repeated acquisition with adjustment of encoding velocity or location of the imaging plane in 69% of patients; measurement in the DDAo was achieved in single acquisition in all cases. Parameters of diastolic flow decay in the PDAo and DDAo, including rate‐corrected (RC) deceleration time and RC flow deceleration yielded a good correlation (r = 0.78; P < 0.01, and r = 0.92; P < 0.01), and a similar diagnostic value for predicting severe CoA. The highest diagnostic accuracy was achieved by RC deceleration time at DDAo (sensitivity 85%, specificity 85%).Conclusion:Characterization of aortic flow profiles at the DDAo offers a quick and reliable noninvasive means of assessing hemodynamically significant CoA. J. Magn. Reson. Imaging 2011;33:1440–1446. © 2011 Wiley‐Liss, Inc.
The diverse pathology and kinetics of mass, nonmass, and focus enhancement on MR imaging of the breast
Authors: Jansen Sanaz A. , Shimauchi Akiko , Zak Lindsay , Fan Xiaobing , Karczmar Gregory S. , Newstead Gillian M. 
Published: May 2011

AbstractPurpose:To compare the pathology and kinetic characteristics of breast lesions with focus‐, mass‐, and nonmass‐like enhancement.Materials and Methods:A total of 852 MRI detected breast lesions in 697 patients were selected for an IRB approved review. Patients underwent dynamic contrast enhanced MRI using one pre‐ and three to six postcontrast T1‐weighted images. The “type” of enhancement was classified as mass, nonmass, or focus, and kinetic curves quantified by the initial enhancement percentage (E1), time to peak enhancement (Tpeak), and signal enhancement ratio (SER). These kinetic parameters were compared between malignant and benign lesions within each morphologic type.Results:A total of 552 lesions were classified as mass (396 malignant, 156 benign), 261 as nonmass (212 malignant, 49 benign), and 39 as focus (9 malignant, 30 benign). The most common pathology of malignant/benign lesions by morphology: for mass, invasive ductal carcinoma/fibroadenoma; for nonmass, ductal carcinoma in situ (DCIS)/fibrocystic change(FCC); for focus, DCIS/FCC. Benign mass lesions exhibited significantly lower E1, longer Tpeak, and lower SER compared with malignant mass lesions (P < 0.0001). Benign nonmass lesions exhibited only a lower SER compared with malignant nonmass lesions (P < 0.01).Conclusion:By considering the diverse pathology and kinetic characteristics of different lesion morphologies, diagnostic accuracy may be improved. J. Magn. Reson. Imaging 2011;33:1382–1389. © 2011 Wiley‐Liss, Inc.
Comparison of a single shot T1‐weighted in‐ and out‐of‐phase magnetization prepared gradient recalled echo with a standard two‐dimensional gradient recalled echo: Preliminary findings
Authors: Herédia Vasco , Ramalho Miguel , de Campos Rafael O.P. , Lee Chang‐Hee , Dale Brian , Vaidean Georgeta D. , Semelka Richard C. 
Published: May 2011

AbstractPurpose:To compare in‐phase (IP) /out‐of‐phase (OP) single shot magnetization‐prepared gradient‐recalled‐echo (MP‐GRE) with a standard two‐dimensional gradient‐recalled‐echo (2D‐GRE), and to compare image quality of MP‐GRE in cooperative and noncooperative subjects.Materials and Methods:Ninety‐six consecutive subjects (52 males, 44 females; mean age, 53.2 ± 16.7 years), both cooperative (n = 73) and noncooperative (n = 23) subjects who had MRI examinations including precontrast T1‐weighted IP/OP MP‐GRE with or without IP/OP 2D‐GRE were included in the study. The sequences were independently qualitatively evaluated by two radiologists. Quantitative analysis of liver fat index, signal‐to‐noise ratio (SNR) and liver‐lesion contrast‐to‐noise ratio (CNR) was also performed. Data were subjected to statistical analysis.Results:The visual detection of the presence or absence of liver steatosis showed no differences between 2D‐GRE and MP‐GRE imaging (k = 1). Minor differences were observed on image quality between MP‐GRE and 2D‐GRE in cooperative subjects, and between MP‐GRE sequences performed in cooperative and noncooperative subjects. Liver fat index results were strongly positively correlated (r = .98; 95% confidence interval [CI] 0.97 to 0.98; P < .0001). Intercept (.14; 95% CI .13 to .15; P < .0001) and slope (.83; 95% CI .79 to .86; P < .0001) were statistically significant.Conclusion:IP/OP MP‐GRE and 2D‐GRE comparably demonstrate the presence or absence of hepatic steatosis. Image quality of MP‐GRE was also comparable to 2D‐GRE, and was not substantially adversely affected if subjects were unable to cooperate with breathholding instructions. J. Magn. Reson. Imaging 2011;33:1482–1490. © 2011 Wiley‐Liss, Inc.
Proton resonance frequency shift‐weighted imaging for monitoring MR‐guided high‐intensity focused ultrasound transmissions
Authors: Chen Jyun‐Wen , Huang Teng‐Yi , Peng Hsu‐Hsia , Chen Wen‐Shiang , Tseng Wen‐Yih Isaac 
Published: May 2011

AbstractPurpose:To combine temperature‐related information of phase images and magnitude images acquired from an MR spoiled gradient echo sequence using a postprocessing method referred to as PRF‐shift‐weighted imaging (PRFSWI).Materials and Methods:Phase images are capable of detecting shifts in proton resonance frequency (PRF) caused by local changes in temperature. Magnitude images provide anatomical information for treatment planning and positioning as well as temperature‐related contrast. We used PRFSWI to produce a phase‐mask and performed multiplication on the magnitude image to increase temperature‐related contrast.Results:Through MRI‐guided focused ultrasound (MRIgFUS) experiments (both ex vivo and in vivo), we determined that PRFSWI is capable of enhancing the contrast of a heated area even in the initial stages of transmitting high‐intensity focused ultrasound energy.Conclusion:The PRFSWI images are sensitive to changes in temperature and display the heated spot directly in the magnitude images. Although the images do not provide quantitative data related to temperature, this method could be used as a complement to the phase temperature mapping method in the real‐time monitoring of MRIgFUS experiments. J. Magn. Reson. Imaging 2011;33:1474–1481. © 2011 Wiley‐Liss, Inc.
Regions of autumn Eurasian snow cover and associations with North American winter temperatures
Authors: Mote Thomas L. , Kutney Emily R. 
Published: May 2011

AbstractThe extent of snow cover over Eurasia during autumn has been shown to be influential in shaping atmospheric circulation over the Northern Hemisphere the following winter via the Arctic Oscillation (AO), North Atlantic Oscillation (NAO), and the Pacific/North American (PNA) teleconnections. Regions of Eurasian snow cover were derived from Principal Component Analysis and compared to winter temperatures across North America for 1967/1968–2007/2008, excluding 1969/1970 and 1971/1972. The score time series of each principal component was then compared to winter averages of the AO, NAO, and PNA indices in order to identify possible links in the snow‐temperature relationship. Results showed that autumn snow cover from northern Scandinavia to the West Siberian Plain is most significantly associated with winter temperatures over the interior of North America. More (less) frequent snow cover over this region is related to lower (higher) winter temperatures over the interior of North America in January, extending to the eastern and southern United States in February. The greatest temperature response to anomalous snow cover occurred near the geographic centre of North America where winter temperature differences exceeded 5 °C. More (less) frequent autumn snow cover across the eastern Tibetan Plateau was associated with higher (lower) temperatures in the Great Basin and eastern Canada. Copyright © 2011 Royal Meteorological Society
Modelling the effects of land‐use/land‐cover changes on the near‐surface atmosphere in southern South America
Authors: Beltrán‐Przekurat Adriana , Pielke Sr Roger A. , Eastman Joseph L. , Coughenour Michael B. 
Published: May 2011

AbstractA fully coupled atmospheric‐biospheric regional climate model, GEMRAMS, was used to evaluate potential effects of land‐use/land‐cover changes (LULCC) on near‐surface atmosphere over a southern South American domain at seasonal time scales. In GEMRAMS, leaf area index and canopy conductance are computed based on modelled temperature, solar radiation, and the water status of the soil and air, allowing a two‐way interaction between canopy and atmosphere. Several austral spring‐early summer simulations were conducted using land cover representing current (i.e. agricultural landscape), natural (i.e. before European settlement), and afforestation scenarios for three periods associated with El Niño‐Southern Oscillation (ENSO) conditions. The shift to agriculture resulted in a generalized increase in albedo, reducing the available energy at the near‐surface. (Correction added on 21 September 2011 after original online publication: in the preceding sentence the word ‘decrease’ was corrected to ‘increase’.) The energy partitioning between latent and sensible heat fluxes changed, leading to distinct temperature responses. A shift from grass to agriculture led to cooler and wetter near‐surface atmospheric conditions. Warmer temperatures resulted from the conversion of wooded grasslands or forest to agriculture. The LULCC‐induced signal was spatially heterogeneous and with a seasonal component associated with vegetation phenology. A significant decrease in maximum temperatures in the southern and central Pampas led to a decrease in the diurnal temperature range. Basing on some observational studies in this region our results suggest a potential strong influence of LULCC on the maximum temperatures in central Argentina in summer. Afforestation resulted overall in cooler temperatures. For both LULCC scenarios the direction of the energy fluxes and temperature changes remained in general the same in two extreme ENSO years, although for some vegetation conversions the signal reversed direction. Overall, the impacts were enhanced during a dry year, but the response also depended on the vegetation types involved in the conversion. The effects on precipitation were insignificant in the agriculture‐conversion scenario and a general increase was found in the afforested scenario. Copyright © 2011 Royal Meteorological Society
Highly Enhanced Nucleating Effect of Melt‐Recrystallized Stereocomplex Crystallites on Poly(L‐lactic acid) Crystallization
Authors: Narita Junichi , Katagiri Mikio , Tsuji Hideto 
Published: May 2011

AbstractIn the general processing temperature range of poly(L‐lactic acid) (PLLA) articles (210–240 °C), PLLA/poly(D‐lactic acid) (PDLA) stereocomplex (SC) crystallites melted just above the endset temperature of SC melting (228–238 °C) and recrystallized during cooling were found to act as the most effective nucleating agents for enhancing the crystallization of PLLA compared to partially melted SC crystallites (211–227 °C) or those melted far above the endset temperature of SC melting (240 and 250 °C) and recrystallized during cooling. The high nucleating effect of the SC crystallites melted in the temperature range of 228–238 °C was found to be caused by their smaller sizes or the larger number of SC crystallites per unit mass. The incorporation of such SC crystallites facilitates the processing of PLLA articles having high crystallinity and, therefore, high heat‐resistance in a shorter period to reduce the production cost. magnified image
Scanning Force Microscopy as Applied to Conformational Studies in Macromolecular Research
Authors: Gallyamov Marat O. 
Published: May 2011

AbstractThe modern state of SFM research on polymer nano‐objects including single chains is discussed in comparison with other similar high‐resolution microscopy techniques. The range of problems to be solved preferentially by SFM is highlighted. Promising methodology to describe quantitatively the morphology of macromolecular objects is proposed. The main benefits of this algorithm seem to be the apparent mathematical correctness as well as the possibility to estimate errors and the confidence of the numbers obtained. Special attention is paid to the dynamic observations of conformational transitions on a substrate in real time regime. This approach allows one to realise direct control of the adsorbed macromolecules by means of exposure to different vapours. Driving forces of the vapour‐induced reorganisation are discussed. magnified image
Noncontact heart rate monitoring using Doppler radar and continuous wavelet transform
Authors: Tariq A. , Ghafouri‐Shiraz H. 
Published: May 2011

AbstractAn algorithm based on wavelet transform is utilized in detecting and examining the heartbeat signal obtained from a Doppler radar.Time–frequency localization properties of wavelet transform were used to examine the signal and provided detail of swift and slow changes in heart rate over very small periods resulting in better determination of the accuracy of the Doppler radar. Till 1 m, a very accurate and robust performance was observed for the Doppler radar. Even at 2‐m heart rate was detectable but not with reasonable accuracy. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26092
Design of broadband dipole for TRI‐band TD‐SCDMA operation
Authors: Wang Y. , Sun B.‐H. , Huang J.‐X. , Wen L.‐H. , Xi D. 
Published: May 2011

AbstractA printed dipole with rotated tapered arms is of considerable interest as a broadband antenna element, and has good potential for use in low cost wireless base station (tri‐band TD‐SCDMA) antenna applications. The antenna which employs a planar reflector is composed of two tapered arms fed by an integrated balun and loaded with a lumped element (a 0.6 pF capacitor), leading to a broad impedance bandwidth and stable gains. The capacitor and the balun comprise the adjustable matching network. Measured result shows that the antenna provides an impedance bandwidth of 40% for voltage standing wave ratio (VSWR) less than 2. Good radiation performances and gains over the operating band are observed. Parametric study of its performance is also performed to provide more information for the antenna design. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26099
DSC‐SIP method for two‐dimensional scattering problem
Authors: Li Hai , Shao Zhenhai , Yeo Sweeping , Leong Yewkong , Lim Menghiot 
Published: May 2011

AbstractA generalized high‐order finite‐difference method [discrete singular convolution‐symplectic integrator propagator (DSC‐SIP)] is proposed to analyze the electromagnetic scattering problem in which the time difference is discretized by the SIP and the spatial difference by the DSC.When compared with the standard finite‐difference time‐domain (FDTD) method, the DSC‐SIP method not only has higher stability and accuracy but also can save the computing memory space and CPU time with suitable meshes. Numerical examples are provided to show the high stability and effectiveness of the proposed method. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26104
A quadrature CMOS clapp voltage‐controlled oscillator
Authors: Jang Sheng‐Lyang , Yeh Hsiu‐An , Chang Chia‐Wei , Juang Miin‐Horng , Chen Han‐Sheng 
Published: May 2011

AbstractA new fully integrated, CMOS Clapp quadrature voltage‐controlled oscillator (QVCO) is presented.The QVCO is composed of two differential n‐core Clapp VCOs coupled by four pMOSFETs and was implemented in the 0.18‐μm CMOS technology with 0.9‐V supply voltage. The die area is 0.574 × 0.866 mm2. At the supply voltage of 0.9 V, the total power consumption is 12.2 mW. The free‐running frequency of the QVCO is tunable from 7.89 to 9.3 GHz as the tuning voltage is varied from 0 to 2 V. The measured phase noise at 1‐MHz frequency offset is −118.65 dBc/Hz at the oscillation frequency of 7.89 GHz, and the figure of merit of the proposed QVCO is about −185.71 dBc/Hz. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26109
Broadband, high gain slot loaded square microstrip array antenna
Authors: Mulgi S. N. , Singh Kishan 
Published: May 2011

AbstractA novel two‐element right angle slot loaded square microstrip array antenna (TESMAA) is presented for 52.18% of bandwidth and 11.22 dB of gain. The effect of different slots placed in the ground plane is studied for enhancing the bandwidth and gain. It is found that when bow‐tie slot is placed in the ground plane of TESMAA the antenna gives maximum 95.54% of bandwidth and 15.92 dB of gain without affecting the nature of broad side radiation characteristics. The design concepts of antennas are described and experimental results are discussed. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26110
Dual‐band power divider using stepped‐impedance resonators structure
Authors: Zhao Shiwei , Tang Zongxi , Guo Fanyu 
Published: May 2011

AbstractA novel dual‐band power divider based on a stepped‐impedance resonators structure for good rejection levels in the extended stopband is presented.The stopband is then extended, and the rejection levels are enhanced by collocating transmission zeros with the unwanted peaks. The simulated and measured results of power divider at 2.3 GHz and 4.7 GHz are given. This kind of power divider has the advantage of better rejection levels in the stopband and return loss compared with traditional dual‐band power divider. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26115
Tri‐band, stand‐alone, PIFA with parasitic, inverted‐L plate and vertical ground wall for WLAN applications
Authors: Lee Cheng‐Tse , Su Saou‐Wen 
Published: May 2011

AbstractA novel, stand‐alone, metal‐plate tri‐band antenna capable of operating in the 2.4, 5.2, and 5.8 GHz WLAN bands is proposed. The antenna occupies the compact size of 5 × 12 × 35 mm3 and mainly comprises a direct‐fed PIFA, a parasitic, inverted‐L (IL) plate, and an antenna ground plane having a vertical ground wall, all constructed from a single metal plate. The parasitic plate is short‐circuited to the ground and provides a space for the signal grounding of the PIFA. The first and the second resonant modes of the PIFA contribute to the 2.4 and 5.8 GHz operation. The frequency ratio can easily be controlled by the meander‐line portion inserted in the PIFA. The additional 5.2‐GHz resonance is generated by the parasitic IL plate. That is, a tri‐WLAN‐band operation can be obtained. Moreover, the antenna is fed by using a mini‐coaxial cable, allowing it to be flexibly deployed inside various wireless devices. The results showed that the antenna operating bands in free space and in a laptop were about the same. The antenna can be used as a quasi‐standard antenna component. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26116
Transition of 94‐GHZ coplanar waveguide to rectangular waveguide on flip‐chip bonding compatible substrate
Authors: Moon Sung‐Woon , Lee Sang‐Jin , Han Min , Rhee Jin‐Koo , Kim Sam‐Dong 
Published: May 2011

AbstractWe demonstrate a 94‐GHz coplanar waveguide (CPW) to rectangular waveguide transition on high permittivity sapphire substrate. Monolithically fabricated uniplanar transition is composed of the fin‐line taper and the open‐type CPW to slotline transition that can be fully integrated with the flip‐chip bonded monolithic microwave integrated circuits (MMICs) on single rigid sapphire substrate. From an optimized design of a low‐loss single‐section transition, we fabricate the back‐to‐back transition for the characterization. The measurements show an insertion loss of ∼1.7 dB at 94 GHz from a single‐section transition, and the performance is successfully verified from a 94‐GHz mixer module assembled with a flip‐chip bonded MMIC mixer. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26121
Fiber optic chemical sensor using fiber coupler probe based on intensity modulation for alcohol detection
Authors: Yasin M. , Harun S. W. , Tan C.F. , Phang S. W. , Ahmad H. 
Published: May 2011

AbstractA simple intensity modulation based displacement sensor using fiber optic coupler probe is proposed and demonstrated for sensing the concentration of alcohol solution. The intensity of light reduces almost linearly with the displacement and the sensitivity of the curve is dependent on the concentration of the alcohol solution. For a concentration change of methanol from 0 to 35 % in distilled water, the sensitivity is observed to be increased linearly with the concentration due to the reduction of the refractive index of the solution. The highest sensitivity is obtained at around 0.00002mV/(%). The stability, high sensitivity and simplicity of the sensor make it suitable for chemical, pharmaceutical, biomedical and process control sensing applications. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26124
Heterogeneous anthropomorphic phantoms with realistic dielectric properties for microwave breast imaging experiments
Authors: Mashal Alireza , Gao Fuqiang , Hagness Susan C. 
Published: May 2011

AbstractWe present a technique for fabricating realistic breast phantoms for microwave imaging experiments. Using oil‐in‐gelatin dispersions that mimic breast tissue dielectric properties at microwave frequencies, we constructed four heterogeneous phantoms spanning the full range of volumetric breast densities. We performed CT scans and dielectric properties measurements to characterize each phantom. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26128
Optically transparent RF‐EO aperture with 20:1 bandwidth
Authors: Nahar Niru K. , Chung Jae‐Young , Tzanidis Ioannis , Sertel Kubilay , Volakis John L. 
Published: May 2011

AbstractWe present a printed radio frequency (RF) aperture (with an extraordinary 20:1 bandwidth) using optically transparent conductor (OTC), conformally placed onto a perfectly conducting ground plane. Of importance is that the OTC enables vertical integration of electro‐optical and RF. Multiple RF aperture layers can be used to achieve 1–300 GHz operation. © 2011 Wiley Periodicals, Inc. Microwave Opt Technol Lett, 2011; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.26129