bluuebunny/crossref_metadata_2025_split huggingface dataset:
Added value of diffusion‐weighted imaging to MR cholangiopancreatography with unenhanced mr imaging for predicting malignancy or invasiveness of intraductal papillary mucinous neoplasm of the pancreas
Authors: Kang Koung Mi , Lee Jeong Min , Shin Cheong‐Il , Baek Jee Hyun , Kim Seung Ho , Yoon Jeong Hee , Han Joon Koo , Choi Byung Ihn 
Published: February 2013

Purpose:To investigate the added value of diffusion‐weighted imaging (DWI) to magnetic resonance cholangiopancreatography (MRCP) with unenhanced MR imaging for predicting the malignancy or invasiveness of intraductal papillary mucinous neoplasms (IPMNs).Materials and Methods:Following Institutional Review Board (IRB) approval, this retrospective study included 52 patients with surgically resected IPMNs and who underwent MRCP, unenhanced MRI, and DWI. Three blinded radiologists evaluated the two image sets, ie, MRCP with unenhanced MR images vs. the combined set with MRCP, unenhanced MR images, and DWI, and scored their confidence for malignancy or for invasiveness of IPMNs. The mean apparent diffusion coefficient (ADC) values of benign IPMNs and of intraductal mucinous carcinomas (IPMCs) were compared. The diagnostic accuracy was calculated using receiver operating characteristic (ROC) curve analysis.esults:The mean ADC of malignant IPMNs (2.05 ± 0.66 × 10−3mm2/sec) was significantly lower than that of benign IPMNs (2.95 ± 0.32 × 10−3mm2/sec, P < 0.0001). Invasive IPMCs (1.51 ± 0.32 × 10−3mm2/sec) showed significantly lower ADC than that of noninvasive IPMCs (2.67 ± 0.23 × 10−3mm2/sec, P = 0.0003). The area of diffusion restriction was more frequently seen in malignant IPMNs than in benign IPMNs (P < 0.00001). The addition of DWI to MRCP with unenhanced MRI did not show a significant improvement for predicting malignant IPMN (P> 0.05), but resulted in a tendency to improve the diagnostic accuracy for the prediction of invasive IPMN in two observers (P = 0.072, P = 0.085).Conclusion:The addition of DWI to MRCP with unenhanced MRI may improve the diagnosis of malignant IPMN and further increase the prediction of invasive IPMC. J. Magn. Reson. Imaging 2013;38:555–563. © 2013 Wiley Periodicals, Inc.
High temporal resolution 3D gadolinium‐enhanced dynamic MR imaging of renal tumors with pharmacokinetic modeling: Preliminary observations
Authors: Chandarana Hersh , Amarosa Alana , Huang William C. , Kang Stella K. , Taneja Samir , Melamed Jonathan , Kim Sungheon 
Published: February 2013

PurposeTo assess dynamic contrast‐enhanced (DCE) magnetic resonance imaging (MRI) tracer pharmacokinetic parameters obtained with Generalized Kinetic Model (GKM) and extended Shutter Speed Model (SSM2) in renal tumors stratified by histologic subtypes.Materials and MethodsIn all, 24 patients with renal tumors were imaged at 1.5 T utilizing DCE‐MRI with high temporal resolution (1.2 sec/temporal frame) prior to surgery. Tracer kinetic analysis was performed for the entire tumor using individualized aortic input function. GKM and SSM2 were employed to generate transfer constant (Ktrans), plasma volume, and interstitial volume. These parameters, and ΔKtrans (KtransSSM2 − KtransGKM) were compared between tumors stratified by histologic subtype.ResultsThere were 25 renal tumors: 15 clear cell, 4 papillary, 3 chromophobe, and 3 oncocytoma/oncocytic subtype. KtransGKM was significantly higher in chromophobe compared to other subtypes (P < 0.01). Using KtransGKM > 1.0 min−1, chromophobe were diagnosed with 100% sensitivity and 90.9% specificity. KtransSSM2 was higher than KtransGKM for all renal tumors except for all chromophobe and two clear cell subtype. Using KtransGKM > 1.0 min−1 and Δ Ktrans < 0, chromophobe could be discriminated from other lesions with 100% accuracy.ConclusionKtrans obtained with GKM and SSM2 analysis can potentially discriminate chromophobe from other renal lesions with high accuracy. J. Magn. Reson. Imaging 2013;38:802–808. © 2013 Wiley Periodicals, Inc.
Volumetric late gadolinium‐enhanced myocardial imaging with retrospective inversion time selection
Authors: Kecskemeti Steve , Johnson Kevin , François Christopher J. , Schiebler Mark L. , Unal Orhan 
Published: February 2013

PurposeTo develop and validate a novel free‐breathing 3D radial late gadolinium‐enhanced magnetic resonance imaging technique (3D LGE‐MRI) with isotropic resolution and retrospective inversion time (TI) selection for myocardial viability imaging.Materials and MethodsThe 3D radial LGE‐MRI method featuring an interleaved and bit‐reversed radial k‐space trajectory was evaluated in 12 subjects that also had clinical breath‐hold Cartesian 2D LGE‐MRI. The 3D LGE‐MRI acquisition requires a predicted TI and a user‐controlled data acquisition window that determines the sampling width around the predicted TI. Sliding window reconstructions with update rates of 1× the repetition time (TR) allow for a user selectable TI to obtain the maximum nulling of the myocardium. The retrospective nature of the acquisition allows the user to choose from a range of possible TI times centered on the expected TI. Those projections most corrupted by respiratory motion, as determined by a respiratory bellows signal, were resampled according to the diminishing variance algorithm. The quality of the left ventricular myocardial nulling on the 3D LGE‐MRI and 2D LGE‐MRI was assessed using a 4‐point Likert scale by two experienced radiologists. Comparison of image quality scores for the two methods was performed using generalized estimating equations.ResultsAll 3D LGE‐MRI cases produced similar nulling of myocardial signal as the 2D LGE‐MRI. The image quality of myocardial nulling was not significantly different between the two acquisitions (mean nulling of 3.4 for 2D vs. 3.1 for 3D, and P = 0.0645). The average absolute deviation from mean scores was also not determined to be statistically significant (1.8 for 2D and 0.4 for 3D and P = 0.1673). Total acquisition time was ∼9 minutes for 3D LGE‐MRI with voxel sizes ranging from 1.63 to 2.03 mm3. Conversely, the total imaging time was twice as long for the 2D DCE‐MRI (>17 minutes) with an eight times larger voxel size of 1.4 × 2.2 × 7.0 mm.ConclusionThe 3D LGE‐MRI technique demonstrated in this study is a promising alternative for the assessment of myocardial viability in patients who have difficulty sustaining breath‐holds for the clinical standard 2D LGE‐MRI. J. Magn. Reson. Imaging 2013;38:1276–1282. © 2013 Wiley Periodicals, Inc.
MMP‐1 promoter polymorphism is associated with primary tendinopathy of the posterior tibial tendon
Authors: Godoy‐Santos Alexandre , Cunha Mirella V. , Ortiz Rafael Trevisan , Fernandes Túlio Diniz , Mattar Rames , dos Santos Maria Cristina L.G. 
Published: February 2013

AbstractPosterior tibial tendon (PTT) dysfunction is recognized as an etiology leading to acquired flatfoot in adults, causing significant functional loss. Many risk factors and systemic conditions have been proposed in literature. However, many patients present PTT dysfunction without any of these characteristics. This suggests that there could be a genetic influence associated with posterior tibial tendinopathy. The purpose of the present study is to investigate the association of the −1607 polymorphism in the promoter gene of MMP‐1 and posterior tibial tendinopathy. The test group included 50 women, who presented PTT dysfunction grade 2 or 3, and who were submitted to surgical treatment, with histopathological examination of the tendon and magnetic resonance image (MRI) confirming tendinopathy, while the control group was 100 asymptomatic women who presented intact PTT at MRI. The results were analyzed using the chi‐square test. The data showed a 75% incidence of the allele 1G and 62% of the genotype 1G/1G at the control group while, at the test group, they showed a 78% incidence of the allele 2G and 72% of the genotype 2G/2G (p < 0.001). The −1607 polymorphism of promoter gene of MMP‐1 is associated with the posterior tibial tendinopathy in the studied population. © 2013 Orthopaedic Research Society Published by Wiley Periodicals, Inc. J Orthop Res 31:1103–1107, 2013
Correction for the T1 effect incorporating flip angle estimated by Kalman filter in cardiac‐gated functional MRI
Authors: Shin Jaemin , Ahn Sinyeob , Hu Xiaoping 
Published: February 2013

PurposeTo develop an improved and generalized technique for correcting T1‐related signal fluctuations (T1 effect) in cardiac‐gated functional magnetie resonance imaging (fMRI) data with flip angle estimation.Theory and MethodsSpatial maps of flip angle and T1 are jointly estimated from cardiac‐gated time series using a Kalman filter. These maps are subsequently used for removing the T1 effect in the presence of B1 inhomogeneity. The new technique was compared with a prior technique that uses T1 only while assuming a homogeneous flip angle of 90°. The robustness of the new technique is demonstrated with simulated and experimental data.ResultsSimulation results revealed that the new method led to increased temporal signal‐to‐noise ratio across a large range of flip angles, T1s, and stimulus onset asynchrony means compared to the T1 only approach. With the experimental data, the new approach resulted in higher average gray matter temporal signal‐to‐noise ratio of seven subjects (84 vs. 48). The new approach also led to a higher statistical score of activation in the lateral geniculate nucleus (P < 0.002).ConclusionThe new technique is able to remove the T1 effect robustly and is a promising tool for improving the ability to map activation in fMRI, especially in subcortical regions. Magn Reson Med 70:1626–1633, 2013. © 2013 Wiley Periodicals, Inc.
Pelvic floor muscle training included in a pregnancy exercise program is effective in primary prevention of urinary incontinence: A randomized controlled trial
Authors: Pelaez Mireia , Gonzalez‐Cerron Silvia , Montejo Rocío , Barakat Rubén 
Published: February 2013

AbstractAimsTo investigate the effect of pelvic floor muscle training (PFMT) taught in a general exercise class during pregnancy on the prevention of urinary incontinence (UI) in nulliparous continent pregnant women.MethodsThis was a unicenter two armed randomized controlled trial. One hundred sixty‐nine women were randomized by a central computer system to an exercise group (EG) (exercise class including PFMT) (n = 73) or a control group (CG) (n = 96). 10.1% loss to follow‐up: 10 from EG and 7 from CG. The intervention consisted of 70–75 sessions (22 weeks, three times per week, 55–60 min/session including 10 min of PFMT). The CG received usual care (which included follow up by midwifes including information about PFMT). Questions on prevalence and degree of UI were posed before (week 10–14) and after intervention (week 36–39) using the International Consultation on Incontinence Questionnaire‐Urinary Incontinence Short Form (ICIQ‐UI SF).ResultsAt the end of the intervention, there was a statistically significant difference in favor of the EG. Reported frequency of UI [Never: CG: 54/60.7%, EG: 60/95.2% (P < 0.001)]. Amount of leakage [None: CG: 45/60.7%, EG: 60/95.2% (P < 0.001)]. There was also a statistically significant difference in ICIQ‐UI SF Score between groups after the intervention period [CG: 2.7 (SD 4.1), EG: 0.2 (SD 1.2) (P < 0.001)]. The estimated effect size was 0.8.ConclusionPFMT taught in a general exercise class three times per week for at least 22 weeks, without former assessment of ability to perform a correct contraction was effective in primary prevention of UI in primiparous pregnant women. Neurourol. Urodynam. 33:67–71, 2014. Copyright © 2013 Wiley Periodicals, Inc.
A mouse model of chronic prostatic inflammation using a human prostate cancer‐derived isolate of Propionibacterium acnes
Authors: Shinohara Debika Biswal , Vaghasia Ajay M. , Yu Shu‐Han , Mak Tim N. , Brüggemann Holger , Nelson William G. , De Marzo Angelo M. , Yegnasubramanian Srinivasan , Sfanos Karen S. 
Published: February 2013

AbstractBACKGROUNDProstatic inflammation has been linked to a number of prostatic diseases such as benign prostatic hyperplasia (BPH), prostatitis syndromes, and prostate cancer. Major unanswered questions include what pathogenic mechanisms, such as bacterial infections, may drive the accumulation of inflammatory infiltrates in the human prostate, and how inflammation might contribute to disease. To study this potential link in an in vivo system, we developed a mouse model of long‐term bacteria‐induced chronic inflammation of the prostate using a human prostatectomy‐derived strain of Propionibacterium acnes.METHODSC57BL/6J mice were inoculated, via urethral catheterization, with vehicle control or a prostatectomy‐derived strain of P. acnes (PA2). Animals were assessed at 2 days, 1, 2, or 8 weeks post‐inoculation via histology and immunohistochemistry (IHC).RESULTSPA2 inoculation resulted in severe acute and chronic inflammation confined to the dorsal lobe of the prostate. Chronic inflammation persisted for at least 8 weeks post‐inoculation. Inflammatory lesions were associated with an increase in the Ki‐67 proliferative index, and diminished Nkx3.1 and androgen receptor (AR) production. Interestingly, the observed response required live bacteria and both IHC and in situ hybridization assays for P. acnes indicated a potential intracellular presence of P. acnes in prostate epithelial cells.CONCLUSIONSTo our knowledge, this is the first mouse model of long‐term prostatic inflammation induced by P. acnes, and more generally, any prostatectomy‐derived bacterial isolate. This model may serve as a valuable preclinical model of chronic prostatic inflammation that can be used to mechanistically study the link between inflammation and prostatic disease. Prostate 73: 1007–1015, 2013. © 2013 Wiley Periodicals, Inc.
Temperature‐dependent emission shift and carrier dynamics in deep ultraviolet AlGaN/AlGaN quantum wells
Authors: Zeng Jianping , Li Wei , Yan Jianchang , Wang Junxi , Cong Peipei , Li Jinmin , Wang Weiying , Jin Peng , Wang Zhanguo 
Published: February 2013

AbstractRadiative and nonradiative processes in deep ultraviolet (DUV) AlGaN/AlGaN multiple quantum wells (MQWs) grown by LP‐MOCVD have been studied by means of deep ultraviolet time‐integrated photoluminescence (PL) and time‐resolved photoluminescence (TRPL) spectroscopy. As the temperature is increased, the peak energy of DUV‐AlGaN/AlGaN MQWs PL emission (Ep) exhibits a similarly anti‐S‐shaped behavior (blueshift – accelerated redshift – decelerated redshift): Ep increases in the temperature range of 5.9–20 K and decreases for 20–300 K, involving an accelerated redshift for 20–150 K and an opposite decelerated redshift for 150–300 K with temperature increase. Especially at high temperature as 300 K, the slope of the Ep redshift tends towards zero. This temperature‐induced PL shift is strongly affected by the change in carrier dynamics with increasing temperature. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Unpaired electrons at the second‐order reduced density matrix level: Covalent bonding, and coulomb and fermi correlations in closed shell systems
Authors: Karafiloglou Padeleimon , Kyriakidou Katerina 
Published: February 2013

AbstractThe usual one‐electron populations in atomic orbitals of closed shell systems are split into unpaired and paired at the (spin‐dependent) second‐order reduced density matrix level. The unpaired electron in an orbital is defined as the “simultaneous occurrence of an electron and an electron hole of opposite spins in the same spatial orbital,” which for simplicity is called “electropon.” The electropon population in a given orbital reveals whether and to what degree the Coulomb correlations, and hence, the chemical bonding between this orbital and the remaining orbitals of the system are globally favorable or unfavorable. The interaction of two electropons in two target orbitals reveals the quality (favorable or unfavorable) and the strength of the covalent bonding between these orbitals; this establish a bridge between the notion of “unpaired electrons” and the traditional covalent structure of valence‐bond (VB) theory. Favorable/unfavorable bonding between two orbitals is characterized by the positive/negative (Coulomb) correlation of two electropons of opposite spins, or alternatively, by the negative/positive (Fermi) correlation of two parallel spin electropons. A spin‐free index is defined, and the relationship between the electropon viewpoint for chemical bonding and the well‐known two‐electron Coulomb and Fermi correlations is established. Benchmark calculations are achieved for ethylene, hexatriene, benzene, pyrrole, methylamine, and ammonia molecules on the basis of physically meaningful natural orbitals. The results, obtained in the framework of both orthogonal and nonorthogonal population analysis methods, provide the same conceptual pictures, which are in very good agreement with elementary chemical knowledge and VB theory. © 2013 Wiley Periodicals, Inc.
Nonvolatile Analog Memory Transistor Based on Carbon Nanotubes and C60 Molecules
Authors: Cho Byungjin , Kim Kyunghyun , Chen Chia‐Ling , Shen Alex Ming , Truong Quyen , Chen Yong 
Published: February 2013

AbstractA nonvolatile analog memory transistor is demonstrated by integrating C60 molecules as charge storage molecules in the transistor gate, and carbon nanotubes (CNTs) in the transistor channel. The currents through the CNT channel can be tuned quantitatively and reversibly to analog values by controlling the number of electrons trapped in the C60 molecules. After tuning, the electrons trapped in the C60 molecules in the gate, and the current through the CNT channel, can be preserved in a nonvolatile manner, indicating the characteristics of the nonvolatile analog memory.
Competitive Dissolution Mechanism of Sulfur in CaMnSilicate Melts: Structural View
Authors: Park Joo Hyun 
Published: February 2013

AbstractThe sulfide capacities of the CaOSiO2MnO(Al2O3MgO) slags were measured at 1873 K over a wide composition range using a gas‐slag equilibration method. The effects of MnO content and the MnO ↔ CaO substitution on the sulfide capacity of molten slag were also investigated based on the structural view of silicate melts. In the multicomponent silicate melts containing high MnO (up to about 50 wt%), the sulfide capacity mainly increased with increasing MnO content. Also, the sulfide capacity and the activity of MnO showed a linear relationship with a slope of unity, indicating that MnO is dominant component controlling the sulfur dissolution behavior into CaMnsilicate melts. The sulfide capacity increased as MnO substituted for CaO in the high silica melts (>30 (±5) wt% SiO2), whereas it decreased by increasing the MnO/CaO ratio in the low silica melts (<30(±5) wt% SiO2). This tendency of sulfide capacity resulted in the clock‐wisely rotating iso‐capacity contours from MnO‐free side to MnO‐rich corner in CaMnsilicate melts. The dissolution mechanism of sulfur in CaMnsilicate melts can be explained by the “Competitive dissolution mechanism.”
Selecting materials for fastening screws for metal members and sheeting
Authors: Misiek Thomas , Käpplein Saskia , Ulbrich Detlef 
Published: February 2013

AbstractThis paper deals with the parameters for choosing the materials for fastening screws used in connections involving thin‐walled sections and thin sheeting. Different types of corrosion processes and repeated bending due to thermal elongation are identified as the most important parameters; these are explained in detail here. Based on that, some general recommendations for choice of material are given.
Tackling the Challenges in the Total Synthesis of Landomycin A
Authors: Yang Xiaoyu , Wang Ping , Yu Biao 
Published: February 2013

ABSTRACT:The twists and turns toward the total synthesis of landomycin A, a prominent angucycline hexasaccharide antibiotic, in particular those toward the stereoselective construction of the di‐ and trideoxyglycosidic linkages, are described.
Correlation and statistical characteristics of aggregate wind power in large transcontinental systems
Authors: Louie Henry 
Published: February 2013

ABSTRACTStudies have shown that the unpredictability and variability of wind power is reduced in systems with large numbers of geographically diverse wind plants. These effects are caused by the decreased correlation of power output between wind plants as their separation and diversity in terrain increases. One way that system operators have increased geographic diversity is by enlarging balancing areas through the physical or administrative connection of adjacent systems. This strategy can be extended from the regional level to the transcontinental level. As such, it is important to study the correlation and statistical characteristics of aggregate wind power between large, distant systems. This paper analyzes multi‐year historical data from four North American system operators—Bonneville Power Administration, Electric Reliability Council of Texas, Midwest Independent Transmission System Operator and PJM—to see how effective transcontinental interconnection of systems is at enabling wind plant integration. The effects of separation and timescale on correlations of instantaneous and hourly variations are analyzed. The analysis is complemented by a study of a hypothetical transcontinental connection of the systems across yearly, monthly, daily and hourly timescales. The results show that correlations between large systems exhibit similar characteristics as the correlations between individual wind plants, but are somewhat larger in magnitude. The transcontinental system exhibits a close to normal distribution of power output and decreased variability, but there is still appreciable and statistically significant correlation at the longer timescales driven by seasonal and diurnal forcing, as well as synoptic weather systems. Copyright © 2013 John Wiley & Sons, Ltd.
Sensor placement strategies for snow water equivalent (SWE) estimation in the American River basin
Authors: Welch Stephen C. , Kerkez Branko , Bales Roger C. , Glaser Steven D. , Rittger Karl , Rice Robert R. 
Published: February 2013

Key Points
There exists temporally stationary properties of basin‐wide SWE distribution
Temporally stationary properties of SWE can be used to inform sensor placement
A quantitative sampling method can be implemented to generate sensor placements
Two‐phase flow in rough‐walled fractures: Comparison of continuum and invasion‐percolation models
Authors: Yang Zhibing , Niemi Auli , Fagerlund Fritjof , Illangasekare Tissa 
Published: February 2013

Key Points
Two different modeling approaches are compared for ranges of applicability
Results from the two models converge at low capillary number conditions
Effect of capillary number is simulated & upscaled Pc‐S relationship is obtained
The Millennium Drought in southeast Australia (2001–2009): Natural and human causes and implications for water resources, ecosystems, economy, and society
Authors: van Dijk Albert I. J. M. , Beck Hylke E. , Crosbie Russell S. , de Jeu Richard A. M. , Liu Yi Y. , Podger Geoff M. , Timbal Bertrand , Viney Neil R. 
Published: February 2013

Key Points
Drivers and impacts of Australia's record drought were analyzed
Impacts accumulated and propagated through the water cycle at different rates
Future droughts may not be managed better than past ones.