bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantification of hepatic macrosteatosis in living, related liver donors using T1‐independent, T2*‐corrected chemical shift MRI
Authors: Joe Eugene , Lee Jeong Min , Kim Kyung Won , Lee Kyung Bun , Kim Soo Jin , Baek Jee Hyun , Shin Cheong Il , Suh Kyung Suk , Yi Nam Joon , Han Joon Koo , Choi Byung Ihn 
Published: July 2012

AbstractPurpose:To evaluate the diagnostic implications of the iterative decomposition of water and fat using echo‐asymmetry and the least‐squares estimation (IDEAL) technique to detect hepatic steatosis (HS) in potential liver donors using histopathology as the reference standard.Materials and Methods:Forty‐nine potential liver donors (32 male, 17 female; mean age, 31.7 years) were included. All patients were imaged using the in‐ and out‐of‐phase (IOP) gradient‐echo (GRE) and IDEAL techniques on a 1.5 T MR scanner. To estimate the hepatic fat fraction (FF), two reviewers performed regions‐of‐interest measurement in 15 areas of the liver seen on the IOP images and on the IDEAL‐FF images. The magnetic resonance imaging (MRI) and pathology values of macrosteatosis were correlated using the Pearson correlation coefficient. We analyzed the diagnostic performance of IOP imaging and IDEAL for detecting HS.Results:The results of the hepatic‐FF estimated on IDEAL were well correlated with the histologic degree of macrosteatosis (γ = 0.902, P < 0.001). IDEAL showed 100% sensitivity and 91% specificity for detecting HS, and IOP imaging showed 87.5% sensitivity and 97% specificity, respectively.Conclusion:IDEAL is a useful tool for the preoperative diagnosis of HS in potential living liver donors; it can also help to avoid unnecessary biopsies in these patients. J. Magn. Reson. Imaging 2012;36:1124–1130. © 2012 Wiley Periodicals, Inc.
Reliability of cerebral blood volume maps as a substitute for diffusion‐weighted imaging in acute ischemic stroke
Authors: deIpolyi Amy R. , Wu Ona , Macklin Eric A. , Schaefer Pamela W. , Schwamm Lee H. , Gilberto Gonzalez R. , Copen William A. 
Published: July 2012

AbstractPurpose:To assess the reliability of cerebral blood volume (CBV) maps as a substitute for diffusion‐weighted MRI (DWI) in acute ischemic stroke. In acute stroke, DWI is often used to identify irreversibly injured “core” tissue. Some propose using perfusion imaging, specifically CBV maps, in place of DWI. We examined whether CBV maps can reliably subsitute for DWI, and assessed the effect of scan duration on calculated CBV.Materials and Methods:We retrospectively identified 58 patients who underwent DWI and MR perfusion imaging within 12 h of stroke onset. CBV in each DWI lesion's center was divided by CBV in the normal‐appearing contralateral hemisphere to yield relative regional CBV (rrCBV). The proportion of lesions with decreased rrCBV was calculated. After using the full scan duration (110 s after contrast injection), rrCBV was recalculated using simulated shorter scans. The effect of scan duration on rrCBV was tested with linear regression.Results:Using the full scan duration (110 s), rrCBV was increased in most DWI lesions (62%; 95% confidence interval, 48–74%). rrCBV increased with increasing scan duration (P < 0.001). Even with the shortest duration (39.5 s) rrCBV was increased in 33% of lesions.Conclusion:Because DWI lesions may have elevated or decreased CBV, CBV maps cannot reliably substitute for DWI in identifying the infarct core. J. Magn. Reson. Imaging 2012;36:1083–1087. © 2012 Wiley Periodicals, Inc.
Stress‐Induced Melting of Crystals in Natural Rubber: a New Way to Tailor the Transition Temperature of Shape Memory Polymers
Authors: Heuwers Benjamin , Quitmann Dominik , Katzenberg Frank , Tiller Joerg C. 
Published: July 2012

AbstractLightly cross‐linked natural rubber (NR, cis‐1,4‐polyisoprene) was found to be an exceptional cold programmable shape memory polymer (SMP) with strain storage of up to 1000%. These networks are stabilized by strain‐induced crystals. Here, we explore the influence of mechanical stress applied perpendicular to the elongation direction of the network on the stability of these crystals. We found that the material recovers its original shape at a critical transverse stress. It could be shown that this is due to a disruption of the strain‐stabilizing crystals, which represents a completely new trigger for SMPs. The variation of transverse stress allows tuning of the trigger temperature Ttrig(σ) in a range of 45 to 0 °C, which is the first example of manipulating the transition of a crystal‐stabilized SMP after programming.
Synthesis of Cyclic Polyamines by Enzymatic Generation of an Amino Aldehyde In Situ
Authors: Cassimjee Karim Engelmark , Marín Sílvia Rodríguez , Berglund Per 
Published: July 2012

AbstractMultifunctional polycationic polyamines, for example, used in drug and gene delivery, have product range limitations in their synthesis methods. Here, we synthesize a polyamine by forming a self‐assembling amino aldehyde from the corresponding amino alcohol with horse liver alcohol dehydrogenase (HLADH), followed by reduction. Circular polyamines were synthesized from 3‐amino‐propan‐1‐ol as starting material, analogous to cyclic polyamines formed from azetidin. The product had an isolated yield of 89.7% or 15.3 g L−1. The predicted range of possible polyamine products by this method is broad since many amino alcohols are putative substrates for HLADH. The enzyme also had activity for 2‐amino‐propan‐1‐ol and 2‐amino‐2‐phenyl‐ethanol, for which the enantioselectivity was 330 (S) and 32 (R), respectively.
Quantitative rapid steady state T1 magnetic resonance imaging for cerebral blood volume mapping in mice: Lengthened measurement time window with intraperitoneal Gd‐DOTA injection
Authors: Perles‐Barbacaru Adriana T. , Berger François , Lahrech Hana 
Published: July 2012

AbstractThis work demonstrates how the rapid steady state T1 MRI technique for cerebral blood volume fraction (BVf) quantification can be used with intraperitoneal Gd‐DOTA injections in mice at 4.7 T. The peak signal amplitude after intravenous administration (0.7 mmol/kg) and the steady state signal amplitude reached 15 min after intraperitoneal administration (6 mmol/kg) in the same mice lead to equivalent BVf measures in the order of 0.02 in the brain. The resulting time window for BVf quantification is ≈30 min and allows for cerebral BVf mapping with increased spatial resolution or signal‐to‐noise ratio, or for monitoring functional BVf changes. A cerebral BVf increase of up to 25% induced by the vasodilator acetazolamide was observed, validating the vascular origin of the signal. The noninvasive and quantitative rapid steady state T1 technique can be used in serial studies to evaluate new drugs or disease models, such as antiangiogenic therapies in tumors. Magn Reson Med, 2013. © 2012 Wiley Periodicals, Inc.
Brown Fades: The End of Court‐Ordered School Desegregation and the Resegregation of American Public Schools
Authors: Reardon Sean F. , Grewal Elena Tej , Kalogrides Demetra , Greenberg Erica 
Published: July 2012

AbstractIn this paper, we investigate whether the school desegregation produced by court‐ordered desegregation plans persists when school districts are released from court oversight. Over 200 medium‐sized and large districts were released from desegregation court orders from 1991 to 2009. We find that racial school segregation in these districts increased gradually following release from court order, relative to the trends in segregation in districts remaining under court order. These increases are more pronounced in the South, in elementary grades, and in districts where prerelease school segregation levels were low. These results suggest that court‐ordered desegregation plans are effective in reducing racial school segregation, but that their effects fade over time in the absence of continued court oversight.
Antioxidant and antibacterial effects of natural phenolic compounds on green composite materials
Authors: España J.M. , Fages E. , Moriana R. , Boronat T. , Balart R. 
Published: July 2012

AbstractThe aim of this study is to establish the thermal performance of a biocomposite (Arbofill kokos®), stabilized with different natural phenolic additives, to check the antioxidant capacity of the resulting compounds. Different phenolic compounds (thymol, carvacrol, α‐tocopherol, and tannic acid) were used as biobased additives and the concentrations ranged between 0.5 wt% and 2 wt%. The results obtained were compared with formulations containing a typical industrial petroleum‐based antioxidant agent (octadecyl‐3‐(3,5‐di‐tert‐butyl‐4‐hydroxyphenyl) propionate). Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were used to characterize the antioxidant performance of the selected natural additives. The antimicrobial effect of these natural phenolic compounds was also studied by analyzing the growth of bacterial colonies. The comparison between the natural phenolic compounds and the petroleum‐based antioxidant compound showed good antioxidant action for natural phenolic compounds; in all the mixtures of biocomposite and antioxidant agent the oxidation onset temperature (OOT) increased in a remarkable way, but the highest stabilization effect was achieved with α‐tocopherol with provides a % increase on OOT of about 45%. With regard to antibacterial activity of the different natural phenolic compounds, thymol, and carvacrol showed interesting antibacterial properties against Staphylococcus aureus. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Internal geometry variability of two woven composites and related variability of the stiffness
Authors: Olave Mireia , Vanaerschot Andy , Lomov Stepan V. , Vandepitte Dirk 
Published: July 2012

AbstractIn this work, the internal geometry measurements of two woven composites are analyzed: cross section of the yarns, fiber volume fraction, crimp, misalignment of the samples, thickness of the plates, nesting value, and so forth. The chosen textile composites are produced using the same resin reinforcement and same architecture, but have different yarn size (3K and 12K). The dispersion of measured geometrical parameters is introduced in a numerical multiscale modeling approach to evaluate the macroscopic stiffness values. A sensitivity analysis is performed for each geometrical parameter and laminate stiffnesses are derived. These are linked to the experimentally obtained elastic properties by tensile tests. Finally, the unit cell size scale effect for measured geometry variability and experimentally obtained elastic properties are evaluated. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Rheological, thermal, and mechanical properties of phosphorus‐containing wholly aromatic thermotropic liquid crystalline polymer‐filled poly(butylene terephthalate) composites
Authors: Yang Zhi , Cao Bo , Zhu Jiaming , Shen Jiabin , Li Jiang , Guo Shaoyun , Wang Yuzhong 
Published: July 2012

AbstractPhosphorus‐containing wholly aromatic thermotropic liquid crystalline polymer (TLCP) reinforced poly(butylene terephthalate) (PBT) composites were prepared. Dynamic rheological analysis displayed that the addition of TLCP led to the decrease of the complex viscosity of PBT. While the thermal stability and tensile modulus were found to be increased distinctly, the results of dynamic mechanical analysis, isothermal crystallization, and morphological observation indicated that these changes were related to the rigid chains and in situ fibrillation of TLCP phase, and the interfacial adhesion between PBT and TLCP. POLYM. COMPOS., 2012. © 2012 Society of Plastics Engineers
Validity of health plan and birth certificate data for pregnancy research
Authors: Andrade Susan E. , Scott Pamela E. , Davis Robert L. , Li De‐Kun , Getahun Darios , Cheetham T. Craig , Raebel Marsha A. , Toh Sengwee , Dublin Sascha , Pawloski Pamala A. , Hammad Tarek A. , Beaton Sarah J. , Smith David H. , Dashevsky Inna , Haffenreffer Katherine , Cooper William O. 
Published: July 2012

ABSTRACTPurposeTo evaluate the validity of health plan and birth certificate data for pregnancy research.MethodsA retrospective study was conducted using administrative and claims data from 11 U.S. health plans and corresponding birth certificate data from state health departments. Diagnoses, drug dispensings, and procedure codes were used to identify infant outcomes (cardiac defects, anencephaly, preterm birth, and neonatal intensive care unit [NICU] admission) and maternal diagnoses (asthma and systemic lupus erythematosus [SLE]) recorded in the health plan data for live born deliveries between January 2001 and December 2007. A random sample of medical charts (n = 802) was abstracted for infants and mothers identified with the specified outcomes. Information on newborn, maternal, and paternal characteristics (gestational age at birth, birth weight, previous pregnancies and live births, race/ethnicity) was also abstracted and compared to birth certificate data. Positive predictive values (PPVs) were calculated with documentation in the medical chart serving as the gold standard.ResultsPPVs were 71% for cardiac defects, 37% for anencephaly, 87% for preterm birth, and 92% for NICU admission. PPVs for algorithms to identify maternal diagnoses of asthma and SLE were ≥ 93%. Our findings indicated considerable agreement (PPVs > 90%) between birth certificate and medical record data for measures related to birth weight, gestational age, prior obstetrical history, and race/ethnicity.ConclusionsHealth plan and birth certificate data can be useful to accurately identify some infant outcomes, maternal diagnoses, and newborn, maternal, and paternal characteristics. Other outcomes and variables may require medical record review for validation. Copyright © 2012 John Wiley & Sons, Ltd.
Silicon Patterning Using Self‐assembled PS‐b‐PAA Diblock Copolymer Masks for Black Silicon Fabrication via Plasma Etching
Authors: Zhang Xin , Sushkov Andrei B. , Metting Christopher J. , Fackler Sean , Drew H. Dennis , Briber R. M. 
Published: July 2012

AbstractThe poly(styrene‐b‐acrylic acid) diblock copolymer is utilized as a novel self‐assembling mask material suitable for pattern transfer applications. This material system has high dry etch selectivity and can produce a variety of feature types and size scales. Different vertical profiles were produced by altering the etch recipes and diblock copolymer or SiO2 mask processing. This patterning technique is used to fabricate antireflective silicon metamaterials that show broadband antireflection properties in the visible and infrared wavelength range. These materials are potentially useful for solar cell and light sensing applications.magnified image
Plasma‐Induced Damage and Surface Functionalization of Double‐Walled Carbon Nanotubes Using Atmospheric Pressure RF Discharge
Authors: Nozaki Tomohiro , Yoshida Shinpei , Okazaki Ken 
Published: July 2012

AbstractDouble‐walled carbon nanotubes (DWCNTs) were synthesized using atmospheric pressure plasma‐enhanced chemical vapor deposition. As‐produced DWCNTs were exposed to He/H2 atmospheric pressure RF discharge for 1 min at 100 °C. The top CNT layer was severely damaged, showing a large D‐band peak in the Raman spectrum. However, hydrogen plasma treatment does not create covalent CH bonds. When a H2/O2 mixture was added, plasma damage was suppressed greatly because O2 scavenges active hydrogen. The CH groups were produced via oxygen‐containing reactive species. Active hydrogen creates sp3‐like carbon structures that destroy graphitized CNTs. Oxygen‐containing species such as OH and HOO are useful to break sp2 bonds and to functionalize CNT sidewalls. magnified image
Rescue of the aggregation prone Itk Pleckstrin Homology domain by two mutations derived from the related kinases, Btk and Tec
Authors: Boyken Scott E. , Fulton D. Bruce , Andreotti Amy H. 
Published: July 2012

AbstractIL‐2 inducible T‐cell kinase (Itk) is a Tec family non‐receptor tyrosine kinase involved in signaling downstream of the T‐cell receptor. Itk contains an amino‐terminal Pleckstrin Homology (PH) domain that binds phosphatidylinositol (3,4,5)‐trisphosphate, recruiting Itk to the plasma membrane upon T‐cell receptor activation. In addition to phosphoinositide binding, accumulating data suggest that the Itk PH domain likely mediates additional interactions outside of the phosphoinositide ligand binding pocket. The structural basis for additional PH domain functions remains elusive because of the poor recombinant expression and in vitro solution behavior of the Itk PH domain. Here, we determine that the lone α‐helix in the Itk PH domain is responsible for the poor solution properties and that mutation of just two residues in the Itk α‐helix to the corresponding amino acids in Btk or Tec dramatically improves the soluble recombinant expression and solution behavior of the Itk PH domain. We present this double mutant as a valuable tool to characterize the structure and function of the Itk PH domain. It is also interesting to note that the precise sites of mutation identified in this study appear as somatic mutations associated with cancerous tissue. Collectively, the findings suggest that the two helical residues in the Itk PH domain may serve an important and unique structural role in wild‐type Itk that differentiates this tyrosine kinase from its related family members.
Combining different design strategies for rational affinity maturation of the MICA‐NKG2D interface
Authors: Henager Samuel H. , Hale Melissa A. , Maurice Nicholas J. , Dunnington Erin C. , Swanson Carter J. , Peterson Megan J. , Ban Joseph J. , Culpepper David J. , Davies Luke D. , Sanders Lisa K. , McFarland Benjamin J. 
Published: July 2012

AbstractWe redesigned residues on the surface of MICA, a protein that binds the homodimeric immunoreceptor NKG2D, to increase binding affinity with a series of rational, incremental changes. A fixed‐backbone RosettaDesign protocol scored a set of initial mutations, which we tested by surface plasmon resonance for thermodynamics and kinetics of NKG2D binding, both singly and in combination. We combined the best four mutations at the surface with three affinity‐enhancing mutations below the binding interface found with a previous design strategy. After curating design scores with three cross‐validated tests, we found a linear relationship between free energy of binding and design score, and to a lesser extent, enthalpy and design score. Multiple mutants bound with substantial subadditivity, but in at least one case full additivity was observed when combining distant mutations. Altogether, combining the best mutations from the two strategies into a septuple mutant enhanced affinity by 50‐fold, to 50 nM, demonstrating a simple, effective protocol for affinity enhancement.
Air–sea interaction in the Gulf of Guinea at intraseasonal time‐scales: wind bursts and coastal precipitation in boreal spring
Authors: Leduc‐Leballeur Marion , de Coëtlogon Gaëlle , Eymard Laurence 
Published: July 2012

AbstractThe role of air–sea interaction in the boreal spring precipitation of the West African monsoon is explored through the wind variability in the Gulf of Guinea. Linear regressions are performed in May–June during the decade 2000–2009 to investigate the origin and effect of the surface wind strengthening north of the Equator. It appears that the equatorial sea‐surface temperature cooling intensifies a surface‐wind equatorial divergence/coastal convergence circulation, and generates a cross‐equatorial pressure gradient, which both strengthen the southerlies north of the Equator. This increases subsidence above the ocean and convection in the northern Gulf of Guinea. In addition, an abrupt change is observed in the surface wind pattern in the eastern equatorial Atlantic (EEA) between April and July. To investigate the transition mechanisms, a reference date is defined as the date when the surface wind north of the Equator becomes and remains stronger than south of the Equator. Thus the maintenance of strong southerlies north of the Equator is linked to a coincident installation of a deep circulation on the whole troposphere and a northward shift of the low atmospheric local circulation. The resulting sharp seasonal transition coincides each year with a southeasterly wind burst, suggesting that the equatorial SST cooling plays a role in the precipitation along the African coast during boreal spring. Copyright © 2012 Royal Meteorological Society
Carbon isotopic characterization of cider CO2 by isotope ratio mass spectrometry: a tool for quality and authenticity assessment
Authors: Cabañero Ana I. , Rupérez Mercedes 
Published: July 2012

RATIONALEThe cider market is an important sector of the food industry in certain regions. Adulteration of cider can happen in several ways: for example, by the addition of sugar, or of exogenous CO2 to certain types of cider. Because such practices are not allowed by either Spanish legislation or the legislation of other countries, it is essential to study possible methods to detect these unauthorized practices. For this purpose a procedure was required to study the stable carbon isotopic composition of CO2 in cider.METHODSA liquid sample of cider was transferred to a vial and CO2 from the headspace of the vial was analyzed using a peripheral device interfaced to an isotope ratio mass spectrometer. Separation of the CO2 from water and ethanol was achieved using a gas chromatography column located in the peripheral device.RESULTSThe values for repeatability and reproducibility obtained indicated the robustness of the method, which is required for routine analysis. Ninety cider samples from various origins were analyzed, most of which showed a 13C content consistent with the declared origin. The δ13C ranged from −24.80‰ to −20.89‰ for ciders with endogenous carbon dioxide (−22.74 ± 0.79‰) and −37.13‰ to −26.00‰ if industrial CO2 was added. Several samples were also suspected of C4 sugar addition prior to the fermentation.CONCLUSIONSA fast, accurate and simple method for cider adulteration detection was developed. The addition of exogenous CO2 as well as C4 sugar addition prior to fermentation could be detected. The method showed advantages over existing methods in term of simplicity (no sample preparation and very long‐term stability of the sample), speed (less than 10 min/sample) and precision ((r ≤0.32 and R ≤0.42). Copyright © 2012 John Wiley & Sons, Ltd.
Production and ionization energies of KnF (n = 2–6) clusters by thermal ionization mass spectrometry
Authors: Veljković F. M. , Djustebek J. B. , Veljković M. V. , Veličković S. R. , Perić‐Grujić A. A. 
Published: July 2012

RATIONALEThe very small clusters of the type KnF are of particular importance since their first ionization energies (IEs) are lower than those of the alkali metal atoms. Theoretical calculation has demonstrated that this kind of cluster represents a potential 'building block' for cluster‐assembly materials with unique structural, electronic, optical, magnetic, and thermodynamic properties. To date, however, there have been no experimental results on the IEs of KnF (n >2) clusters.METHODKnF (n = 2–6) clusters were produced by the evaporation of a solid potassium fluoride salt using a modified thermal ionization source of modified design, and mass selected by a magnetic sector mass spectrometer where their IEs were determined.RESULTSClusters KnF (n = 3–6) were detected for the first time. The order of the ion intensities was K2F+> > K4F+> > K3F+K6F+ > K5F+. The determined IEs were 3.99 ± 0.20 eV for K2F, 4.16 ± 0.20 eV for K3F, 4.27 ± 0.20 eV for K4F, 4.22 ± 0.20 eV for K5F, and 4.31 ± 0.20 eV for K6F. The IEs of KnF increase slightly with the increase in potassium atom number from 2 to 6. We also observed that the presence of a fluorine atom leads to increasing ionization energy of bare metal potassium clusters.CONCLUSIONSThe modified thermal ionization source provides an efficient way of obtaining the fluorine‐doped potassium clusters. These results also present experimental proof that KnF (n = 2–6) clusters belong to the group of 'superalkali' species. Copyright © 2012 John Wiley & Sons, Ltd.