bluuebunny/crossref_metadata_2025_split huggingface dataset:
Crossover comparison of ferumoxytol and gadobenate dimeglumine for abdominal MR‐angiography at 3.0 tesla: Effects of contrast bolus length and flip angle
Authors: Schubert Tilman , Motosugi Utaroh , Kinner Sonja , Colgan Timothy J. , Sharma Samir D. , Hetzel Scott , Wells Shane , Campo Camilo A. , Reeder Scott B. 
Published: November 2016

PurposeFerumoxytol (FE) has gained interest as an alternative to gadolinium‐based contrast agents (GBCAs). The purpose of this study was to evaluate and optimize ferumoxytol dose and T1 weighting, in comparison to a conventional GBCA.Materials and MethodsTwelve healthy volunteers (six women / six men, mean age 44.3 years) were recruited for this study. Scanning was performed on a clinical 3 Tesla (T) MRI system. Gadobenate dimeglumine (GD)‐enhanced MRA was performed followed by FE‐enhanced MRA 1 month later. Volunteers were randomly assigned to a diluted (n = 6) or undiluted (n = 6) dose of GD (0.1 mmol/kg), and to FE doses of 4 mg/kg (n = 6) or 2 mg/kg (n = 6). First pass and steady‐state MRA were performed for GD‐ and FE‐enhanced MRA. Flip‐angle optimization was performed after FE administration. Quantitative analysis included relative contrast‐to‐noise ratio (relCNR) measurements for all acquisitions. First pass GD‐ and FE‐enhanced MRA images were evaluated qualitatively.ResultsRelCNR was significantly higher with undiluted GD (31.8, 95% confidence interval [CI], 27.7–35.9) compared with diluted GD (16.2; 95% CI, 12.2–20.3; P = 0.001) and both 4 mg/kg FE (12.5; 95% CI, 8.5–16.4; P < 0.001) and 2 mg/kg FE (9.1; 95% CI, 5.1–13.2; P < 0.001) during first pass. Relative CNR did not decrease with FE 5 min postinjection compared with GD. Flip‐angle analysis revealed relative CNR‐peaks at 30° for FE 4 mg/kg and at 20° for FE 2 mg/kg. Diluted GD (P = 0.013) and FE 4 mg/kg (P = 0.01) revealed significantly higher image quality scores compared with undiluted GD during first pass.ConclusionThis study shows an equivalent image quality of FE and GD for first pass MRA even though GD showed significantly higher relative CNR.Level of Evidence: 1Technical Efficacy: Stage 2J. MAGN. RESON. IMAGING 2017;45:1617–1626
Whole‐tumor MRI histogram analyses of hepatocellular carcinoma: Correlations with Ki‐67 labeling index
Authors: Hu Xin‐Xing , Yang Zhao‐Xia , Liang He‐Yue , Ding Ying , Grimm Robert , Fu Cai‐Xia , Liu Hui , Yan Xu , Ji Yuan , Zeng Meng‐Su , Rao Sheng‐Xiang 
Published: November 2016

PurposeTo evaluate whether whole‐tumor histogram‐derived parameters for an apparent diffusion coefficient (ADC) map and contrast‐enhanced magnetic resonance imaging (MRI) could aid in assessing Ki‐67 labeling index (LI) of hepatocellular carcinoma (HCC).Materials and MethodsIn all, 57 patients with HCC who underwent pretreatment MRI with a 3T MR scanner were included retrospectively. Histogram parameters including mean, median, standard deviation, skewness, kurtosis, and percentiles (5th, 25th, 75th, 95th) were derived from the ADC map and MR enhancement. Correlations between histogram parameters and Ki‐67 LI were evaluated and differences between low Ki‐67 (≤10%) and high Ki‐67 (>10%) groups were assessed.ResultsMean, median, 5th, 25th, 75th percentiles of ADC, and mean, median, 25th, 75th, 95th percentiles of enhancement of arterial phase (AP) demonstrated significant inverse correlations with Ki‐67 LI (rho up to −0.48 for ADC, −0.43 for AP) and showed significant differences between low and high Ki‐67 groups (P < 0.001–0.04). Areas under the receiver operator characteristics (ROC) curve for identification of high Ki‐67 were 0.78, 0.77, 0.79, 0.82, and 0.76 for mean, median, 5th, 25th, 75th percentiles of ADC, respectively, and 0.74, 0.81, 0.76, 0.82, 0.69 for mean, median, 25th, 75th, 95th percentiles of AP, respectively.ConclusionHistogram‐derived parameters of ADC and AP were potentially helpful for predicting Ki‐67 LI of HCC.Level of Evidence:3Technical Efficacy: Stage 3J. MAGN. RESON. IMAGING 2017;46:383–392
Methane emissions from oceans, coasts, and freshwater habitats: New perspectives and feedbacks on climate
Authors: Hamdan Leila J. , Wickland Kimberly P. 
Published: November 2016

AbstractMethane is a powerful greenhouse gas, and atmospheric concentrations have risen 2.5 times since the beginning of the Industrial age. While much of this increase is attributed to anthropogenic sources, natural sources, which contribute between 35% and 50% of global methane emissions, are thought to have a role in the atmospheric methane increase, in part due to human influences. Methane emissions from many natural sources are sensitive to climate, and positive feedbacks from climate change and cultural eutrophication may promote increased emissions to the atmosphere. These natural sources include aquatic environments such as wetlands, freshwater lakes, streams and rivers, and estuarine, coastal, and marine systems. Furthermore, there are significant marine sediment stores of methane in the form of clathrates that are vulnerable to mobilization and release to the atmosphere from climate feedbacks, and subsurface thermogenic gas which in exceptional cases may be released following accidents and disasters (North Sea blowout and Deepwater Horizon Spill respectively). Understanding of natural sources, key processes, and controls on emission is continually evolving as new measurement and modeling capabilities develop, and different sources and processes are revealed. This special issue of Limnology and Oceanography gathers together diverse studies on methane production, consumption, and emissions from freshwater, estuarine, and marine systems, and provides a broad view of the current science on methane dynamics of aquatic ecosystems. Here, we provide a general overview of aquatic methane sources, their contribution to the global methane budget, and key uncertainties. We then briefly summarize the contributions to and highlights of this special issue.
Well‐Defined Magnetic Responsive Polymers Containing Ammonium FeCl4 from ROMP
Authors: Yu Xiaoliang , Mu Chunyan , Dai Dongdong , Yuan Xiaoyan , Zhang Ke , Ren Lixia 
Published: November 2016

Well‐defined magnetic polyelectrolytes with tetrachlorideferrate (FeCl4−) as counter ion are prepared. In this approach, norbornene‐based monomer containing ammonium chloride group (TAENDI‐Cl) is designed and synthesized. Well‐defined magnetic polymers (Poly(TAENDI‐FeCl4)) are obtained by ring‐opening metathesis polymerization of TAENDI‐Cl in the presence of Grubbs third generation catalyst followed by complexing with FeCl3. Magnetic block copolymers are thus prepared. Both the monomer and polymers are paramagnetic as measured by superconducting quantum interference device method. Studies show that the magnetic susceptibility increases with increasing degree of polymerization (DP) and reaches maximum at DP of 100, and then decreases with increasing DP. Block copolymer with lower FeCl4− content shows higher magnetic susceptibility. And, by introducing FeCl4−, the polymers show obviously magnetic responsive in solution, powder, and film which have potential applications in magnetic switching, transport, and separation.
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Study of spontaneous E/Z isomerization of bis[(Z)‐cyanomethylidene]‐diazapentacyclodienedicarboxylates by 1H, 13C, and 15N NMR spectroscopy, X‐ray, and quantum chemical calculation data
Authors: Afonin Andrei V. , Vashchenko Alexander V. , Albanov Alexander I. , Nosyreva Valentina V. , Mal'kina Anastasiya G. , Trofimov Boris A. 
Published: November 2016

AbstractX‐ray data show that the diethyl 6,13‐bis[(Z)‐cyanomethylidene]‐5,5,14,14‐tetramethyl‐4,15‐dioxa‐7,12‐diazapentacyclo[9.5.2.02,10.03,7.012,16]octadeca‐8,17‐diene‐10,17‐dicarboxylate is formed as the ZZ isomer and diastereomer with the (1R*,2R*,3R*,10S*,11R*,12R*,16R*) configuration. The 1H, 13C, and 15N NMR data exhibit that on standing in chloroform‐d solution, there is a spontaneous isomerization of this compound resulting in a thermodynamically stable mixture of the ZZ, ZE, EE, and EZ isomers with the same backbone. Using the 2D [1H–1H] COSY, [1H–13C] HSQC, and [1H–13C, 1H–15N] HMBC NMR techniques and quantum chemical calculations makes it possible a complete assignment of signals in the 1H, 13C, and 15N NMR spectra of each of the isomers. Such isomerization does not occur for similar compounds with the more bulky substituents at the 1,3‐oxazolidine rings. Copyright © 2016 John Wiley & Sons, Ltd.
Copolymerization of 2,3,4,5,6‐Pentafluorostyrene and Methacrylic Acid by Nitroxide‐Mediated Polymerization: The Importance of Reactivity Ratios
Authors: Kannan Nirmal B. , Lessard Benoît H. 
Published: November 2016

Amphiphilic block copolymers of 2,3,4,5,6‐pentafluorostyrene (PFS) and methacrylic acid (MAA) are synthesized via nitroxide‐mediated polymerization (NMP). It is established that to obtain a controlled copolymerization a minimum of 40 mol% of PFS is required, which is significantly greater than other copolymerization systems such as using 4.5–8 mol% styrene or 1 mol% of 9‐(4‐vinylbenzyl)‐9H‐carbazole to control the copolymerization of methacrylates. It is surmised that this lack of control is due to the reactivity ratios that favor the addition of MAA rather than PFS (rPFS = 0.14, rMAA = 6.97). However this reactivity ratio pair suggests that a one‐shot delayed injection approach can be utilized to synthesize almost pure block copolymers in one pot. Therefore, poly(PFS)‐b‐(PFS‐ran‐MAA) block copolymers are synthesized by a one‐shot delayed addition of MAA. While the concentration of irreversibly terminated chains is evident these results suggest a promising route to the synthesis of fluorinated amphiphilic block copolymers by NMP.
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Physiological basis of vascular autocalibration (VasA): Comparison to hypercapnia calibration methods
Authors: Kazan Samira M. , Huber Laurentius , Flandin Guillaume , Ivanov Dimo , Bandettini Peter , Weiskopf Nikolaus 
Published: November 2016

PurposeThe statistical power of functional MRI (fMRI) group studies is significantly hampered by high intersubject spatial and magnitude variance. We recently presented a vascular autocalibration method (VasA) to account for vascularization differences between subjects and hence improve the sensitivity in group studies. Here, we validate the novel calibration method by means of direct comparisons of VasA with more established measures of baseline venous blood volume (and indirectly vascular reactivity), the M‐value.MethodsSeven healthy volunteers participated in two 7 T (T) fMRI experiments to compare M‐values with VasA estimates: (i) a hypercapnia experiment to estimate voxelwise M‐value maps, and (ii) an fMRI experiment using visual stimulation to estimate voxelwise VasA maps.ResultsWe show that VasA and M‐value calibration maps show the same spatial profile, providing strong evidence that VasA is driven by local variations in vascular reactivity as reflected in the M‐value.ConclusionThe agreement of vascular reactivity maps obtained with VasA when compared with M‐value maps confirms empirically the hypothesis that the VasA method is an adequate tool to account for variations in fMRI response amplitudes caused by vascular reactivity differences in healthy volunteers. VasA can therefore directly account for them and increase the statistical power of group studies. The VasA toolbox is available as a statistical parametric mapping (SPM) toolbox, facilitating its general application. Magn Reson Med 78:1168–1173, 2017. © 2016 The Authors Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine.
Rapid myelin water imaging in human cervical spinal cord
Authors: Ljungberg Emil , Vavasour Irene , Tam Roger , Yoo Youngjin , Rauscher Alexander , Li David K.B. , Traboulsee Anthony , MacKay Alex , Kolind Shannon 
Published: November 2016

PurposeMyelin water imaging (MWI) using multi‐echo T2 relaxation is a quantitative MRI technique that can be used as an in vivo biomarker for myelin in the central nervous system. MWI using a multi‐echo spin echo sequence currently takes more than 20 min to acquire eight axial slices (5 mm thickness) in the cervical spinal cord, making spinal cord MWI impractical for implementation in clinical studies.MethodsIn this study, an accelerated gradient and spin echo sequence (GRASE), previously validated for brain MWI, was adapted for spinal cord MWI. Ten healthy volunteers were scanned with the GRASE sequence (acquisition time 8.5 min) and compared with the multi‐echo spin echo sequence (acquisition time 23.5 min).ResultsUsing region of interest analysis, myelin estimates obtained from the two sequences were found to be in good agreement (mean difference = −0.0092, 95% confidence interval =
0.0092 ± 0.061; regression slope = 1.01, ρ = 0.9). MWI using GRASE was shown to be highly reproducible with an average coefficient of variation of 6.1%.ConclusionThe results from this study show that MWI can be performed in the cervical spinal cord in less than 10 min, allowing for practical implementation in multimodal clinical studies. Magn Reson Med 78:1482–1487, 2017. © 2016 International Society for Magnetic Resonance in Medicine.
Teaching clinical diagnostic reasoning and research‐mindedness in obstetric and gynaecologic sonography online using Research Skills Development Framework
Authors: Parange Nayana , Marks Kirstin 
Published: November 2016

AbstractThe Australian Qualifications Framework (AQF) requires that graduates of postgraduate degrees have ‘specialised knowledge and skills for research, and/or professional practice and/or further learning’. Australian Sonographer Accreditation Registry (ASAR) accreditation standards now emphasise that medical sonography graduates need to graduate with research capacity in addition to clinical skills and align with AQF framework. To meet these requirements, University of South Australia medical sonography programs, which are delivered externally and online, underwent a major curriculum redesign and changes implemented in 2015. Research Skills Development Framework (RSDF) was embedded across the program to develop sonography‐specific research‐minded thinking for clinical reasoning. RSDF is a conceptual model utilising six facets of enquiry which are ‘embark and clarify’, ‘find and generate’, ‘critically evaluate’, ‘organise’, ‘synthesise and analyse’ and ‘communicate’. This paper reports the experience with RSDF in the online environment to develop problem solving skills, critical thinking and clinical reasoning in one clinical course within the programs, that is, the obstetric and gynaecologic sonography course. This process can be easily translated to the face to face clinical environment and may assist clinical supervisors in clinical supervision and training.
Household financial burden of phenylketonuria and its impact on treatment in China: a cross‐sectional study
Authors: Wang Lin , Zou Hui , Ye Fang , Wang Kundi , Li Xiaowen , Chen Zhihua , Chen Jie , Han Bingjuan , Yu Weimin , He Chun , Shen Ming 
Published: November 2016

SummaryBackgroundPhenylketonuria (PKU) is a rare inborn disease, which, untreated, leading to severe neurobehavioral dysfunction. Considering its complexity, the management of PKU may bring a formidable economic burden to parents and caregivers. It is still unknown what the out‐of‐pocket expenses are for a patient with PKU in China. This paper explores the household financial burden of classical PKU and its impact on Chinese families in a quantitative manner for the first time.MethodsA non‐interventional and observational study was conducted at the China‐Japan Friendship Hospital, one of the national centers for inherited metabolic disorders in China. The medical and non‐medical household financial burdens were consolidated into a questionnaire to evaluate the out‐of‐pocket costs (OOPCs) of PKU treatment and follow‐up.FindingsThe total OOPCs were USD$3766.1 (0y), USD$3795.2 (1–2 ys), USD$4657.7 (3–4 ys), USD$5979.9 (5–8 ys), and USD$5588.7 (9 ys and older) for PKU patients of different age groups. The median economic burden of classical PKU was 75.0 % of total annual family income (range 1.0–779.1 %), and 94.4 % of the families exceeding the threshold considered as catastrophic expenditure. There was a negative correlation between the financial burden and the proportion of time when Phe concentrations were in the desired target range (120–250 μmol/L) in 0–4‐ys group (r = ‐0.474, p = 0.026).ConclusionsThe management of PKU is associated with a severe financial burden on patients’ families, which may lead to insufficient treatment or variation of blood Phe concentration. The current reimbursement policies are as yet inadequate. A national reimbursement system targeting treatment practices for PKU patients and other rare diseases across China is imperative.
The Impact of Living with Klinefelter Syndrome: A Qualitative Exploration of Adolescents and Adults
Authors: Turriff Amy , Macnamara Ellen , Levy Howard P. , Biesecker Barbara 
Published: November 2016

AbstractKlinefelter syndrome (XXY) is a common yet significantly underdiagnosed condition with considerable medical, psychological and social implications. Many health care providers lack familiarity with XXY, resulting in medical management challenges and a limited understanding of the personal impact of the condition. Genetic counselors benefit from understanding the challenges adolescents and men with XXY face to effectively address their medical and psychosocial needs. The purpose of this study was to understand the impact of living with XXY as an adolescent or an adult. Individuals aged 14 to 75 years with self‐reported XXY were recruited from online support networks to complete a web‐based survey that included open‐ended questions. Open‐ended responses were coded and analyzed thematically (n = 169 to 210 for each open‐ended question). Over half of respondents to the open‐ended questions reported challenges in finding health care providers who are knowledgeable about XXY, with many describing an extensive diagnostic odyssey and relief when receiving a diagnosis. Individuals sought support coping with the challenges they face and acknowledgement of the positive aspects of XXY. Recommendations are made for how genetic counseling can enhance quality of life for individuals living with XXY.
Correlates of Postpartum Depression in First Time Mothers Without Previous Psychiatric Contact
Authors: Sylvén S.M. , Thomopoulos T.P. , Kollia N. , Jonsson M. , Skalkidou A. 
Published: November 2016

AbstractBackgroundPostpartum depression (PPD) is a common disorder after childbirth. The strongest known predictors are a history of depression and/or a history of PPD. However, for a significant proportion of women, PPD constitutes their first depressive episode. This study aimed to gain further insight into the risk factors for PPD in first time mothers without previous psychiatric contact.MethodsWomen delivering in Uppsala University Hospital, Sweden, from May 2006 to June 2007, were asked to participate and filled out questionnaires five days and six weeks postpartum, containing inter alia the Edinburgh Postnatal Depression Scale (EPDS). Univariate logistic regression models, as well as a path analysis, were performed to unveil the complex interplay between the study variables.ResultsOf the 653 participating primiparas, 10.3% and 6.4% reported depressive symptoms (EPDS ≥ 12 points) five days and six weeks postpartum, respectively. In the path analysis, a positive association between anxiety proneness and depressive symptoms at five days and six weeks postpartum was identified. For depressive symptoms six weeks after delivery, additional risk factors were detected, namely depressive symptoms five days postpartum and subjective experience of problems with the baby. Caesarean section and assisted vaginal delivery were associated with fewer depressive symptoms at 6 six weeks postpartum.ConclusionsIdentification of anxiety proneness, delivery mode and problems with the baby as risk factors for self-reported depressive symptoms postpartum in this group of primiparas can be important in helping health care professionals identify women at increased risk of affective disorders in the perinatal period, and provide a base for early intervention.
Gender‐Dependent Differences in Hip Range of Motion and Impingement Testing in Asymptomatic College Freshman Athletes
Authors: Czuppon Sylvia , Prather Heidi , Hunt Devyani M. , Steger‐May Karen , Bloom Nancy J. , Clohisy John C. , Larsen Richard , Harris‐Hayes Marcie 
Published: November 2016

AbstractBackgroundAthletic activity is a proposed factor in the development and progression of intra‐articular hip pathology. Early diagnosis and preventive treatments in “at‐risk” athletes are needed.ObjectivesOur primary objective was to report hip range of motion (ROM) and prevalence of positive impingement testing in asymptomatic college freshman athletes. Our secondary objective was to determine whether an association exists between hip ROM and a positive flexion‐adduction‐internal rotation (FADIR) test.DesignCross‐sectional study.SettingCollegiate athletic campus.ParticipantsFour hundred thirty (299 male, 131 female) freshman athletes reporting no current or previous hip pain.MethodsDuring the athletes' preseason medical screening, trained examiners performed a hip‐specific exam to obtain data for hip ROM and impingement testing.Main Outcome MeasurementsBilateral passive ROM measures included hip flexion, and hip internal and external rotation with the hip flexed 0° and 90°.ResultsMean age of male participants was 18.5 ± 0.8 and female participants was 18.3 ± 0.6 years (P = .003). Male participants demonstrated less hip ROM than female participants in flexion (115.8 ± 11.2° versus 122.0 ± 10.5°, P < .001), internal rotation in 90° flexion (26.9 ± 9.8° versus 34.7 ± 10.7°, P < .001) and 0° flexion (29.0 ± 9.8° versus 38.9 ± 10.1°, P < .001), and external rotation in 90° flexion (44.7 ± 10.9° versus 49.7 ± 10.4°, P < .001) but not for external rotation in 0° flexion (39.8 ± 11.1° versus 37.6 ± 11.5°, P = .06). Pain with FADIR test on the right and left hip were reported in 11.9% and 14.5% of athletes, respectively. Gender and a positive FADIR were not related (male 12.2%, female 15.3%, P = .36).ConclusionsIn asymptomatic college freshman athletes, male athletes generally demonstrated less hip ROM than female athletes. In addition, a positive FADIR was more prevalent than previously reported in healthy young adults. Preseason screenings that use these baseline data in conjunction with other examination findings may allow identification of athletes at future risk for hip pain and/or injury.Level of EvidenceIV
A note on the optimal dividends paid in a foreign currency
Authors: Eisenberg Julia , Krühner Paul 
Published: November 2016

AbstractWe consider an insurance entity endowed with an initial capital and a surplus process modelled as a Brownian motion with drift. It is assumed that the company seeks to maximise the cumulated value of expected discounted dividends, which are declared or paid in a foreign currency. The currency fluctuation is modelled as a Lévy process. We consider both cases: restricted and unrestricted dividend payments. It turns out that the value function and the optimal strategy can be calculated explicitly.