bluuebunny/crossref_metadata_2025_split huggingface dataset:
On the exact decomposition threshold for even cycles
Authors: Taylor Amelia 
Published: October 2018

AbstractA graph has a ‐decomposition if its edge set can be partitioned into cycles of length . We show that if , then has a ‐decomposition, and if , then has a ‐decomposition, where and (we assume is large and satisfies necessary divisibility conditions). These minimum degree bounds are best possible and provide exact versions of asymptotic results obtained by Barber, Kühn, Lo and Osthus. In the process, we obtain asymptotic versions of these results when is bipartite or satisfies certain expansion properties.
Clinical characteristics and risk factors for stent–stone complex formation following biliary plastic stent placement in patients with common bile duct stones
Authors: Kaneko Junichi , Kawata Kazuhito , Watanabe Shinya , Chida Takeshi , Matsushita Masahiro , Suda Takafumi , Kobayashi Yoshimasa 
Published: October 2018

AbstractBackgroundStent–stone complex (SSC) formation is one of the complications of endoscopic biliary stent placement. This study aimed to clarify the clinical characteristics and risk factors for SSC formation following plastic stent (PS) placement in patients with common bile duct (CBD) stones.MethodsWe retrospectively reviewed the charts of 78 patients with CBD stones who had undergone 107 biliary stent placements as palliative treatment. Demographic, historical, and stent‐related data were collected and analyzed.ResultsAt PS removal, SSC formations were observed in 18% of the 107 cases (SSC group) studied and not in the remaining 82% (non‐SSC group). The duration of PS placement was significantly longer in the SSC group. The increase in CBD diameter during the stenting period as well as the incidence of cholangitis at PS removal was significantly greater in the SSC group. Multivariate analysis identified long‐term (≥301 days) PS placement and the increase in CBD diameter during the stenting period as independent factors for SSC formation.ConclusionsLong‐term PS placement induces a risk of SSC formation in patients with CBD stones. The increase in diameter of CBD during the period of PS placement is a predictive factor for SSC formation in this situation.
Learning curve and surgical factors influencing the surgical outcomes during the initial experience with laparoscopic pancreaticoduodenectomy
Authors: Nagakawa Yuichi , Nakamura Yoshiharu , Honda Goro , Gotoh Yoshitaka , Ohtsuka Takao , Ban Daisuke , Nakata Kohei , Sahara Yatsuka , Velasquez Vittoria Vanessa D. M. , Takaori Kyoichi , Misawa Takeyuki , Kuroki Tamotsu , Kawai Manabu , Morikawa Takanori , Yamaue Hiroki , Tanabe Minoru , Mou Yiping , Lee Woo‐Jung , Shrikhande Shailesh V. , Conrad Claudius , Han Ho‐Seong , Tang Chung Ngai , Palanivelu Chinnusamy , Kooby David A. , Asbun Horacio J. , Wakabayashi Go , Tsuchida Akihiko , Takada Tadahiro , Yamamoto Masakazu , Nakamura Masafumi 
Published: October 2018

AbstractBackgroundLaparoscopic pancreaticoduodenectomy (LPD) requires sufficient laparoscopic training for optimal outcomes. Our aim is to determine the learning curve and investigate the factors influencing surgical outcomes during the learning curve.MethodsWe analyzed surgical results of 150 consecutive cases of LPD performed by three hepatopancreatobiliary surgeons during their 50 first cases. Learning curves were constructed by cumulative sum (CUSUM) analysis. Preoperative factors influencing resection time and blood loss were investigated in the introductory and stable periods.Results The learning curve could be divided into three phases: initial (1–20 cases), plateau (21–30), and stable (31–50). Resection time with lymph node dissection was significantly longer during the introductory period (initial and plateau periods) (P < 0.01) but not the stable phase (P = 0.51). Multivariate analysis revealed that patients with pancreatitis had longer resection times and massive blood loss in both the introductory and stable periods (stable phase). High visceral fat area was also significantly related to massive blood loss in the introductory period (P = 0.04).ConclusionsHepatopancreatobiliary surgeons need more than 30 cases until LPD becomes stable. Lymph node dissection and patients with high visceral fat area and concomitant pancreatitis should be avoided during the introductory period of the learning curve.
Impact of eosinophil-peroxidase (EPX) deficiency on eosinophil structure and function in mouse airways
Authors: Percopo Caroline M , Krumholz Julia O , Fischer Elizabeth R , Kraemer Laura S , Ma Michelle , Laky Karen , Rosenberg Helene F 
Published: October 2018

Abstract
Eosinophil peroxidase (EPX) is a major constituent of the large cytoplasmic granules of both human and mouse eosinophilic leukocytes. Human EPX deficiency is a rare, autosomal-recessive disorder limited to the eosinophil lineage. Our intent was to explore the impact of EPX gene deletion on eosinophil content, structure, and function. In response to repetitive intranasal challenge with a filtrate of the allergen, Alternaria alternata, we found significantly fewer eosinophils peripherally and in the respiratory tracts of EPX−/− mice compared to wild-type controls; furthermore, both the major population (Gr1−/lo) and the smaller population of Gr1hi eosinophils from EPX−/− mice displayed lower median fluorescence intensities (MFIs) for Siglec F. Quantitative evaluation of transmission electron micrographs of lung eosinophils confirmed the relative reduction in granule outer matrix volume in cells from the EPX−/− mice, a finding analogous to that observed in human EPX deficiency. Despite the reduced size of the granule matrix, the cytokine content of eosinophils isolated from allergen-challenged EPX−/− and wild-type mice were largely comparable to one another, although the EPX−/− eosinophils contained reduced concentrations of IL-3. Other distinguishing features of lung eosinophils from allergen-challenged EPX−/− mice included a reduced fraction of surface TLR4+ cells and reduced MFI for NOD1. Interestingly, the EPX gene deletion had no impact on eosinophil-mediated clearance of gram-negative Haemophilus influenzae from the airways. As such, although no clinical findings have been associated with human EPX deficiency, our findings suggest that further evaluation for alterations in eosinophil structure and function may be warranted.
Eosinophils from the lungs of allergen-challenged EPX−/− mice display differential expression of Siglec F and maintain reduced quantities of IL-3.
Disrupted functional connectivity and activity in the white matter of the sensorimotor system in patients with pontine strokes
Authors: Wang Jingjuan , Yang Zhipeng , Zhang Miao , Shan Yi , Rong Dongdong , Ma Qingfeng , Liu Hesheng , Wu Xi , Li Kuncheng , Ding Zhaohua , Lu Jie 
Published: October 2018

BackgroundWhite matter (WM) blood oxygenation level‐dependent (BOLD) signals are reported to be related to neural activity. However, sensitivity of WM BOLD signals to disease remains unclear.PurposeTo investigate WM BOLD signal changes, directional variations of resting‐state correlations in sensorimotor system in patients with pontine strokes, and to determine the relationship between WM BOLD signals and motor deficits.Study TypeProspective.SubjectsEthical approval was obtained from the local Ethics Committee and each participant gave written informed consent. Sixteen patients with focal pontine lesions and 16 age‐matched control subjects were included.Field Strength/Sequence3.0T T1‐weighted anatomic images using a 3D magnetization‐prepared rapid gradient‐echo sequence. Resting‐state fMRI images using gradient‐echo echo‐planar imaging sequence. Diffusion‐weighted images using single‐shot spin‐echo diffusion echo‐planar imaging.AssessmentRelevant WM tracts in the sensorimotor system by region of interest‐wise analysis were identified. Power spectra of BOLD signals and anisotropy of resting‐state correlations were measured in sensorimotor system and compared between two groups. Their relationships with clinical scores were analyzed.Statistical TestsTwo‐sample t‐test; partial correlation analysis.ResultsPower spectra of BOLD signals in nerve tracts on the ipsilesional side were significantly decreased (P < 0.05). Compared with that in healthy subjects, the anisotropy of resting‐state correlations along identified WM tracts was decreased in the thalamus‐dorsolateral prefrontal cortex bundle on the contralesional side, and all nerve tracts on the ipsilesional side. Partial least squares regression analysis showed the predicted outcome scores correlated significantly with actual Fugl‐Meyer scores (R2 = 0.944, P = 0.013).Data ConclusionOur findings suggest that disrupted activity and functional connectivity in WM areas of the sensorimotor system can be detected in pontine strokes, and may serve as a biomarker for motor function prediction.Level of Evidence: 2Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2019;49:478–486.
Absolute Quantification of Phosphor‐Containing Metabolites in the Liver Using 31P MRSI and Hepatic Lipid Volume Correction at 7T Suggests No Dependence on Body Mass Index or Age
Authors: Pfleger Lorenz , Gajdošík Martin , Wolf Peter , Smajis Sabina , Fellinger Paul , Kuehne Andre , Krumpolec Patrik , Trattnig Siegfried , Winhofer Yvonne , Krebs Michael , Krššák Martin , Chmelík Marek 
Published: October 2018

BackgroundHepatic disorders are often associated with changes in the concentration of phosphorus‐31 (31P) metabolites. Absolute quantification offers a way to assess those metabolites directly but introduces obstacles, especially at higher field strengths (B0 ≥ 7T).PurposeTo introduce a feasible method for in vivo absolute quantification of hepatic 31P metabolites and assess its clinical value by probing differences related to volunteers' age and body mass index (BMI).Study TypeProspective cohort.Subjects/PhantomsFour healthy volunteers included in the reproducibility study and 19 healthy subjects arranged into three subgroups according to BMI and age. Phantoms containing 31P solution for correction and validation.Field Strength/SequencePhase‐encoded 3D pulse‐acquire chemical shift imaging for 31P and single‐volume 1H spectroscopy to assess the hepatocellular lipid content at 7T.AssessmentA phantom replacement method was used. Spectra located in the liver with sufficient signal‐to‐noise ratio and no contamination from muscle tissue, were used to calculate following metabolite concentrations: adenosine triphosphates (γ‐ and α‐ATP); glycerophosphocholine (GPC); glycerophosphoethanolamine (GPE); inorganic phosphate (Pi); phosphocholine (PC); phosphoethanolamine (PE); uridine diphosphate‐glucose (UDPG); nicotinamide adenine dinucleotide‐phosphate (NADH); and phosphatidylcholine (PtdC). Correction for hepatic lipid volume fraction (HLVF) was performed.Statistical TestsDifferences assessed by analysis of variance with Bonferroni correction for multiple comparison and with a Student's t‐test when appropriate.ResultsThe concentrations for the young lean group corrected for HLVF were 2.56 ± 0.10 mM for γ‐ATP (mean ± standard deviation), α‐ATP: 2.42 ± 0.15 mM, GPC: 3.31 ± 0.27 mM, GPE: 3.38 ± 0.87 mM, Pi: 1.42 ± 0.20 mM, PC: 1.47 ± 0.24 mM, PE: 1.61 ± 0.20 mM, UDPG: 0.74 ± 0.17 mM, NADH: 1.21 ± 0.38 mM, and PtdC: 0.43 ± 0.10 mM. Differences found in ATP levels between lean and overweight volunteers vanished after HLVF correction.Data ConclusionExploiting the excellent spectral resolution at 7T and using the phantom replacement method, we were able to quantify up to 10 31P‐containing hepatic metabolites. The combination of 31P magnetic resonance spectroscopy imaging data acquisition and HLVF correction was not able to show a possible dependence of 31P metabolite concentrations on BMI or age, in the small healthy population used in this study.Level of Evidence: 2Technical Efficacy: Stage 1J. Magn. Reson. Imaging 2019;49:597–607.
PET/MRI in Breast Cancer
Authors: Pujara Akshat C. , Kim Eric , Axelrod Deborah , Melsaether Amy N. 
Published: October 2018

Positron emission tomography / magnetic resonance imaging (PET/MRI) is an emerging imaging technology that allows for the acquisition of multiple MRI parameters simultaneously with PET data. In this review, we address the technical requirements of PET/MRI including protocols and tracers, the potential of integrated localized breast PET/MRI exams, and possible applications of whole‐body PET/MRI in breast cancer patients. Currently, PET/MRI can be performed on sequential and integrated PET/MRI scanners but, as not all practices can access these dedicated machines, several studies look at PET and MRI exams that are performed separately on separate scanners within a short time frame. This practice likely provides similar clinical data, although exact colocalization for iso‐voxel analysis, currently performed only in research, is not possible. In PET/MRI, the MRI sequences are flexible and can be customized according to the aim of the exam. The most commonly used radiotracer is 18F‐FDG; however, tracers that image hypoxia and drug targets such as estrogen receptors and HER2 are in development and may increase the utility of PET/MRI. For dedicated breast PET/MRI, a potential advantage over standard breast MRI alone may be the complementary sensitivities of MRI for extent of disease within the breast and PET for axillary and internal mammary nodal metastases. Moreover, layers of multiparametric MRI and PET metrics derived from the index lesion are being investigated as predictors of response to neoadjuvant therapy. These data may eventually be able to be quantified and mined in a way that furthers radiomics and also precision medicine. Finally, in whole‐body imaging of breast cancer patients, single‐institution studies have found that PET/MRI detects more metastases than PET at about half the radiation dose, although a survival benefit has not been shown. For now, whole‐body PET/MRI in breast cancer patients may be most relevant for young patients who may undergo serial surveillance exams.Level of Evidence: 3Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2019;49:328–342.
Prospective Evaluation of an R2* Method for Assessing Liver Iron Concentration (LIC) Against FerriScan: Derivation of the Calibration Curve and Characterization of the Nature and Source of Uncertainty in the Relationship
Authors: Jhaveri Kartik S. , Kannengiesser Stephan A.R. , Ward Richard , Kuo Kevin , Sussman Marshall S. 
Published: October 2018

BackgroundFerriScan is the method‐of‐choice for noninvasive liver iron concentration (LIC) quantification. However, it has a number of drawbacks including cost and expediency.Purpose/HypothesisTo characterize an R2*‐based MRI technique that may potentially be used as an alternative to FerriScan. This was accomplished through the derivation of a calibration curve that characterized the relationship between FerriScan‐derived LIC and R2*. The nature and source of uncertainty in this curve were investigated. It was hypothesized that the source of uncertainty is heterogeneity of LIC across the liver.Study TypeProspective.SubjectsIn all, 125 patients (69 women, 56 men) undergoing chelation treatment for iron overload prospectively underwent FerriScan and R2* MRI during the same exam.Field Strength/SequencePulse sequences included 2D multislice spin‐echo pulse for FerriScan, and a prototype 3D 6‐echo gradient echo acquisition for R2* mapping at 1.5T.AssessmentA linear calibration curve was derived from the relationship between FerriScan‐derived LIC estimates and R2* through least‐squares fitting.Statistical TestsThe nature of the uncertainty in the curve was characterized through tests of normality and homoscedasticity. The source of uncertainty was tested by comparing the magnitude of LIC variation over the FerriScan ROI to the observed uncertainty in the R2*‐derived LIC estimates.ResultsA linear relationship between logarithmically transformed FerriScan‐derived LIC and R2* (log{FerriScan‐derived LIC} = 1.029 log{R2*} – 3.822) was confirmed. Uncertainty was random, with a behaviour that was normal and homoscedastic. The source of uncertainty was confirmed as iron heterogeneity across the liver. The nontransformed calibration curve was: FerriScan‐derived LIC = 0.0266⋅R2*, with a constant coefficient‐of‐variation of 0.32.Data ConclusionFerriScan and R2* techniques were found to provide equivalent quantification of LIC in this study. Any difference in accuracy or precision was at a level lower than the uncertainty caused by variation in LIC over the liver.Level of Evidence: 1Technical Efficacy: Stage 2J. Magn. Reson. Imaging 2019;49:1467–1474.
Four unequal substep FDTD (4 USS‐FDTD) method with extremely low numerical dispersion error
Authors: Kusaf Mehmet , Oztoprak Abdullah Y. 
Published: October 2018

AbstractA new unconditionally stable split‐step FDTD method is introduced which has unequal substeps. The ratio of the unequal substeps, τ, is utilized to obtain extremely low anisotropic errors. It is shown that for any set of space step and time step values, there is a τ value which gives zero anisotropic error. Polynomials are obtained in terms of time and space step sizes for τ and the average normalized numerical phase velocity which can be used to correct for anisotropic error and the average numerical phase velocity. The 2 polynomials can be integrated into the simulation programs, so that the user gets an almost unity normalized phase velocity in all directions, for any chosen time step size and space step size. In this way, large time steps up to Nyquist rate can be used. The method is also suitable for multidomain applications, which makes the method very efficient. A further study shows that the method is very wideband, and for 1% dispersion, error bandwidth is larger than 10:1.
Just flip it!—CRT implantation in a patient with dextrocardia and situs inversus totalis
Authors: Steinberg Christian , Deyell Marc W. , Chakrabarti Santabhanu 
Published: October 2018

AbstractImplantation of a cardiac resynchronization therapy (CRT) device in patients with congenital heart disease may be challenging because of the particular underlying anatomy. We present the case of a right‐sided transvenous implantation of a dual‐chamber CRT‐D device in a patient with situs inversus totalis and mirror image dextrocardia. To facilitate our anatomic orientation and to overcome unusual hand‐eye coordination problems, we decided to flip the fluoroscopic image projection by 180° (right‐left), creating the optical impression of a “normalized” heart position (levocardia). This simple approach allowed us to successfully implant the device using a conventional left‐sided CRT delivery system.
Solid confirmation for the origin of the low‐wave stray light in Raman spectra
Authors: Jiao Fei , Dong Xiaofeng , Gong Yan , Chen WeiHua , Wang Yan , Zhang Shu‐Lin 
Published: October 2018

AbstractThe stray light appearing in the low wavenumber region of Raman spectra has long been the intrinsic hindrance in Raman spectroscopy. In this work, we confirmed that the stray light mentioned above originates from the grating secondary maxima of Rayleigh scattering experimentally and theoretically. This result also gives a clear inspiration for the suppression of such kind of stray light.
Coupling Raman spectroscopy and drop tensiometry for in situ monitoring of radical polymerization in a single monomer droplet
Authors: Dropsit Elise , Desbrières Jacques , Chapron David , Hoppe Sandrine , Durand Alain , Bourson Patrice 
Published: October 2018

AbstractTwo complementary analytical techniques, Raman spectroscopy and drop tensiometry, were coupled in an original homemade experimental setup for in situ monitoring of radical polymerization in a single monomer droplet. Homopolymerizations of styrene and methyl methacrylate initiated by 2,2′‐azobisisobutyronitrile in a single droplet surrounded by an aqueous medium containing sodium dodecylsulfate were investigated. Monomer conversion (from Raman spectroscopy) and interfacial properties (interfacial tension and dilational moduli, from drop tensiometry) were simultaneously acquired in situ.
Overview of sample introduction techniques prior to GC for the analysis of volatiles in solid materials
Authors: Asfaw Adissu Alemayehu , Aspromonte Juan , Wolfs Kris , Van Schepdael Ann , Adams Erwin 
Published: October 2018

AbstractSample preparation and introduction techniques are very critical steps in gas chromatography analysis and particularly in the analysis of volatiles in solid samples. In these cases, they can be divided into two main categories: direct and indirect approaches, based on how the solid sample is treated, i.e. with and without dissolution (or extraction) of analytes from the solid sample. To enable routine application, coupling with sample preparation techniques (especially solid or solvent‐based microextractions) is needed to achieve automation. Here, an overview of the most common sample introduction techniques for gas chromatography with their advantages and drawbacks is presented and discussed, including references to relevant examples. So, this review can serve as guidance for new users.
Application of solid‐phase microextraction in current biomedical research
Authors: Roszkowska Anna , Miękus Natalia , Bączek Tomasz 
Published: October 2018

AbstractExtraction of endogenous compounds and drugs and their corresponding metabolites from complex matrices, such as biofluids and solid tissues, requires adequate analytical approach facilitating qualitative and quantitative analysis. To this end, solid‐phase microextraction has been introduced as modern technology that is capable of efficient and high‐throughput extraction of compounds due to its ability to amalgamate sampling, extraction, and pre‐concentration steps, while requiring minimal use of organic solvents. The ability of solid‐phase microextraction to enable analyses on small‐volume biological samples and growing availability of biocompatible solid‐phase microextraction coatings make it a highly useful technology for variety of applications. For example, solid‐phase microextraction is particularly useful for identifying biomarkers in metabolomics studies, and it can be successfully applied in pharmaceutical and toxicological studies requiring the fast and sensitive determination of drug levels, especially those that are present at low levels in biological matrices such as plasma, urine, saliva, and hair. Moreover, solid‐phase microextraction can be directly applied in in vivo studies because this extraction technique is non‐exhaustive and its biocompatible probes offer minimal invasiveness to the analyzed system. In this article, we review recent progress in well‐established solid‐phase microextraction technique for in vitro and in vivo analyses of various metabolites and drugs in clinical, pharmaceutical, and toxicological applications.