bluuebunny/crossref_metadata_2025_split huggingface dataset:
Full use of the liquid nature of the stationary phase: The development of elution‐extrusion counter current chromatography
Authors: Sun Xiao , Pei Dong , Duan Wen‐Da , Liu Jian‐Fei , Di Duo‐Long , Huang Xin‐Yi 
Published: July 2020

AbstractElution‐extrusion counter current chromatography extrudes the most solute retained in the column with the highest possible peak resolution. It can greatly improve the hydrophobic window. In recent years, elution‐extrusion counter current chromatography has received extensive attention in the separation of complex samples. This article first reviews the development and application of elution‐extrusion counter current chromatography, including its origin, mechanism, advantages and disadvantages, and some representative applications. At the same time, this review also shared our visions and ideas on how to improve the elution‐extrusion mode. This article aims to provide certain reference for the research of this technology.
Development of a novel, fast, simple, nonderivative HPLC method with direct UV measurement for quantification of memantine hydrochloride in tablets
Authors: Piponski Marjan , Stoimenova Tanja Bakovska , Stefov Stefan , Balkanov Trajan , Serafimovska Gordana Trendovska , Logoyda Liliya 
Published: July 2020

AbstractFast, simple, accurate, and reproducible reverse phase‐high‐performance liquid chromatography method with direct ultraviolet measurement of memantine hydrochloride in tablets was developed, without any chemical derivatization pretreatment. Three main problems appear during chromatographic analysis of memantine: detection, achieving appropriate column retention, and limited choice of mobile phase components, as a result of memantine molecular structure. Among more than 35 tested columns, the best retention and peak symmetry yielded two C8 and three C18 columns with different characteristics, at a temperature of 30°C, mobile phase composed of 1%, v/v, acetonitrile and 99%, v/v, of 0.05–0.1% phosphoric acid or 2.5–5 mmol phosphate buffer, at flow rate of 1 mL/min and injection volume of 5 µL. The retention time of memantine was between 2.6 and 4 min. Both mobile phase concepts showed perfect linearity, precision, and accuracy. This is the first successful and reproducible direct reverse phase‐high‐performance liquid chromatography–ultraviolet quantification method for memantine.
Cervical Fibrosis as a Predictor of Dysphagia
Authors: Nachalon Yuval , Nativ‐Zeltzer Nogah , Evangelista Lisa M. , Dhar Shumon I. , Lin Sharon J. , Shen Shih C. , Belafsky Peter C. 
Published: July 2020

ObjectiveRadiotherapy of head and neck cancer (HNCA) causes dysfunction through radiation‐induced fibrosis (RIF). We hypothesize that the degree of cervical fibrosis is associated with swallowing dysfunction. This study evaluated the association between cervical fibrosis and swallowing dysfunction in patients after radiation therapy for HNCA.Study DesignCross sectional study.MethodologyA convenience sample of patients with dysphagia who were at least 1 year post radiation therapy for HNCA underwent simultaneous cervical ultrasound (US) and video‐fluroscopic swallow study (VFSS). US determinants of fibrosis were measurements of sternocleidomastoid fascia (SCMF) thickness bilaterally at the level of the cricoid. Primary and secondary outcome variables on VFSS were pharyngeal constriction ratio, a validated measure of pharyngeal contractility, and penetration aspiration scale (PAS). A qualitative assessment of lateral neck rotation was performed as a functional measure of neck fibrosis.ResultsSimultaneous cervical US and VFSS examinations were performed on 18 patients with a history of radiotherapy for HNCA and on eight controls. The mean (±SD) age of the entire cohort (N = 26) was 66 (±10) years. Individuals with a history of radiation had significantly thinner mean SCMF (0.26 [±0.04 mm]) compared to controls (0.48 [±0.06 mm]; P < .05). Individuals with thinner SCMF were more likely to have moderate to severe restriction in lateral neck rotation, a higher PCR, and a higher PAS (P < .05).ConclusionThinner sternocleidomastoid fascia on ultrasound in patients having undergone radiotherapy for head and neck cancer was associated with reduced lateral neck movement, poorer pharyngeal constriction and greater penetration/aspiration scale. The data suggest that cervical fibrosis is associated with swallowing dysfunction in head and neck cancer survivors and support the notion that, “As the neck goes, so does the swallow.”Level of Evidence3. Laryngoscope, 131:548–552, 2021
Disruption of Sinonasal Epithelial Nrf2 Enhances Susceptibility to Rhinosinusitis in a Mouse Model
Authors: Ramanathan Murugappan , Tharakan Anuj , Sidhaye Venkataramana K. , Lane Andrew P. , Biswal Shyam , London Nyall R. 
Published: July 2020

Objectives/HypothesisOxidative stress has been postulated to play an important role in chronic rhinosinusitis. Nrf2 is a transcription factor that is involved in the regulation of multiple antioxidant genes, and its function has been previously shown to be important in sinonasal inflammation. Although the sinonasal implications of whole body Nrf2−/− has been reported, the function of sinonasal epithelial expression of Nrf2 has not been studied. The primary aim of this study was to generate a mouse model that is genetically deficient in epithelial‐specific Nrf2 and to understand its role in regulating sinonasal inflammation.Study DesignBasic science.MethodsAn epithelial‐specific Nrf2 knockout mouse was generated by crossing Krt5‐cre(K5) with Nrf2flox/flox. A papain‐induced model of rhinosinusitis was performed in the resulting K5 Nrf2−/− mouse. Immunohistochemistry was performed to quantify goblet cell hyperplasia. Mucosal cellular infiltrates were quantified using flow cytometry, and tissue cytokines were measured using an enzyme‐linked immunosorbent assay. Lastly, the cellular source of type 2 cytokines was determined using intracellular cytokine staining.ResultsPapain‐sensitized mice lacking epithelial‐specific Nrf2 demonstrate increased goblet cell hyperplasia, significant tissue eosinophilia, and statistically significant increase in mucosal IL‐13 when compared to Nrf2 wild‐type mice. Lastly, mucosal T cells were identified as the cellular source of IL‐13.ConclusionsWe demonstrate enhanced severity of eosinophilic sinonasal inflammation from disruption of the epithelial‐specific Nrf2 pathway. The responsiveness of Nrf2‐directed antioxidant pathways may act as a major determinant of susceptibility to eosinophilic inflammation and may have potential as a therapeutic target for chronic rhinosinusitis.Level of EvidenceNA Laryngoscope, 131:713–719, 2021
Dual Transport of Active Substances with a Layer‐by‐Layer‐Based Drug Delivery System to Terminate Inflammatory Processes
Authors: Brueckner Mandy , Hollenbach‐Latzko Sebastian , Reibetanz Uta 
Published: July 2020

AbstractConventional therapies for chronic inflammation with high dose application of active agents are often accompanied with severe side effects so that other therapeutical strategies shall be developed to be less physically demanding but still highly efficient. Locally applied Layer‐by‐Layer (LbL) microcarriers transporting a low, but efficient dosage of active agents directly into the inflamed tissue offer a gentle therapy option. Here, the inhibition of highly degradative enzyme human neutrophile elastase (HNE) is adressed, which is produced and secreted by neutrophile granulocytes (PMNs) in the progress of inflammation. The protected transport and release of its natural inhibitor α1‐antitrypsin (AT) as a constituent of the microcarrier's biopolymer multilayer allows for an efficient inhibition of extra‐ and intracellular elastase. The HOCl scavenger molecule cefoperazone, which preserves AT activity, as an additional multilayer constituent induces a much higher efficacy of the inhibitor. The successful assembly of both agents in different layers of the multilayer and the subsequent HNE inhibition in PMNs is investigated. The parallel application of cefoperazone leads to an enhanced inhibitory effect even with reduced AT amount and reduced carrier:cell ratio. It is demonstrated that the modular assembly strategy of LbL carriers allows for efficient synergistic effect of active agents in inflammatory process.
Sulfonated RAFT Copolymers as Heparin Mimetics: Synthesis, Reactivity Ratios, and Anticoagulant Activity
Authors: Nahain Abdullah Al , Ignjatovic Vera , Monagle Paul , Tsanaktsidis John , Vamvounis George , Ferro Vito 
Published: July 2020

AbstractThe glycosaminoglycan heparin is a clinically important anticoagulant drug, primarily used to reduce the risk of blood clots (thrombosis) during surgery. Despite its importance in medicine and its continuous use over many decades, heparin suffers from several limitations associated with its heterogeneity and its extraction from animal tissues. In order to address these limitations, reversible addition‐fragmentation chain transfer polymerization is utilized to prepare a library of heparin mimetic copolymers from the sulfonated monomers sodium 4‐styrene sulfonate, potassium‐3‐sulfopropyl acrylate, potassium‐3‐sulfopropyl methacrylate, and sodium‐2‐acrylamido‐2‐methyl‐1‐propane sulfonate. Copolymers are prepared using combinations of two different monomers in various ratios. Monomer reactivity ratios are also determined for some representative monomer combinations, and all polymers are characterized by 1H NMR spectroscopy and gel permeation chromatography. The anticoagulant activities of the copolymers are determined by activated partial thromboplastin time and thrombin clotting time assays and structure–activity relationships are explored.
Sharp bounds for finitely many embedded eigenvalues of perturbed Stark type operators
Authors: Liu Wencai 
Published: July 2020

AbstractFor perturbed Stark operators , the author has proved that must be larger than in order to create N linearly independent eigensolutions in [29]. In this paper, we apply generalized Wigner–von Neumann type functions to construct embedded eigenvalues for a class of Schrödinger operators, including a proof that the bound is sharp.
Targeting the Liver‐Brain Axis with Hop‐Derived Flavonoids Improves Lipid Metabolism and Cognitive Performance in Mice
Authors: Paraiso Ines L. , Revel Johana S. , Choi Jaewoo , Miranda Cristobal L. , Lak Parnian , Kioussi Chrissa , Bobe Gerd , Gombart Adrian F. , Raber Jacob , Maier Claudia S. , Stevens Jan F. 
Published: July 2020

ScopeSphingolipids including ceramides are implicated in the pathogenesis of obesity and insulin resistance. Correspondingly, inhibition of pro‐inflammatory and neurotoxic ceramide accumulation prevents obesity‐mediated insulin resistance and cognitive impairment. Increasing evidence suggests the farnesoid X receptor (FXR) is involved in ceramide metabolism, as bile acid‐FXR crosstalk controls ceramide levels along the gut‐liver axis. The authors previously reported that FXR agonist xanthohumol (XN), the principal prenylated flavonoid in hops (Humulus lupulus), and its hydrogenated derivatives, α,β‐dihydroxanthohumol (DXN), and tetrahydroxanthohumol (TXN), ameliorated obesity‐mediated insulin resistance, and cognitive impairment in mice fed a high‐fat diet.Methods and resultsTo better understand how the flavonoids improve both, lipid and bile acid profiles in the liver are analyzed, sphingolipid relative abundance in the hippocampus is measured, and linked them to metabolic and neurocognitive performance. XN, DXN, and TXN (30 mg kg−1 BW per day) decrease ceramide content in liver and hippocampus; the latter is linked to improvements in spatial learning and memory. In addition, XN, DXN, and TXN decrease hepatic cholesterol content by enhancing de novo synthesis of bile acids.ConclusionThese observations suggest that XN, DXN, and TXN may alleviate obesity‐induced metabolic and neurocognitive impairments by targeting the liver‐brain axis.
The structural, optical, and morphological properties of NiO‐Cu prepared by spray pyrolysis technique
Authors: Mohamad Haidar J. , Abdul‐Husaain Yahyah Mustafa , Al‐Jarah Uday Ali Sabeeh 
Published: July 2020

AbstractThe technique of spray pyrolysis used to prepare the pure thin films NiO and NiO:Cu. In this study, the nickel chloride salt solution (NiCl2⋅6H2O) was used to fabricate thin films deposited on a glass substrate. The structural, optical, and morphological fabricated properties of the samples were investigated. X‐ray diffraction reveals a polycrystalline nickel oxide layer with a crystalline cubic form, with (111), (200), and (222). Atomic force microscopic studied the surface morphology of the thin‐film samples. The fabrication process of growth was at the specific doping ratio (0%, 0.5%, 1%, 1.5%, and 2%) where all thin films had a cubic structure. The energy difference for the NiO and NiO:Cu reference samples have ranged from 3.25 to 3.5 eV. The mobility, magnetoresistance, resistivity, and conductivity were measured and presented as well as the relationship between current‐voltage and current‐resistivity.
In vivo 3D brain and extremity MRI at 50 mT using a permanent magnet Halbach array
Authors: O’Reilly Thomas , Teeuwisse Wouter M. , de Gans Danny , Koolstra Kirsten , Webb Andrew G. 
Published: July 2020

PurposeTo design a low‐cost, portable permanent magnet‐based MRI system capable of obtaining in vivo MR images within a reasonable scan time.MethodsA discretized Halbach permanent magnet array with a clear bore diameter of 27 cm was designed for operation at 50 mT. Custom‐built gradient coils, RF coil, gradient amplifiers, and RF amplifier were integrated and tested on both phantoms and in vivo.ResultsPhantom results showed that the gradient nonlinearity in the y‐direction and z‐direction was less than 5% over a 15‐cm FOV and did not need correcting. For the x‐direction, it was significantly greater, but could be partially corrected in postprocessing. Three‐dimensional in vivo scans of the brain of a healthy volunteer using a turbo spin‐echo sequence were acquired at a spatial resolution of 4 × 4 × 4 mm in a time of about 2 minutes. The T1‐weighted and T2‐weighted scans showed a good degree of tissue contrast. In addition, in vivo scans of the knee of a healthy volunteer were acquired at a spatial resolution of about 3 × 2 × 2 mm within 12 minutes to show the applicability of the system to extremity imaging.ConclusionThis work has shown that it is possible to construct a low‐field MRI unit with hardware components costing less than 10 000 Euros, which is able to acquire human images in vivo within a reasonable data‐acquisition time. The system has a high degree of portability with magnet weight of approximately 75 kg, gradient and RF amplifiers each 15 kg, gradient coils 10 kg, and spectrometer 5 kg.
Imaging microstructure with diffusion and susceptibility MR: neuronal density correlation in Disrupted‐in‐Schizophrenia‐1 mutant mice
Authors: Gong Nan‐Jie , Dibb Russell , Pletnikov Mikhail , Benner Eric , Liu Chunlei 
Published: July 2020

PurposeTo probe cerebral microstructural abnormalities and assess changes of neuronal density in Disrupted‐in‐Schizophrenia‐1 (DISC1) mice using non‐Gaussian diffusion and quantitative susceptibility mapping (QSM).Materials and MethodsBrain specimens of transgenic DISC1 mice (n = 8) and control mice (n = 7) were scanned. Metrics of neurite orientation dispersion and density imaging (NODDI) and diffusion kurtosis imaging (DKI), as well as QSM, were acquired. Cell counting was performed on Nissl‐stained sections. Group differences of imaging metrics and cell density were assessed. Pearson correlations between imaging metrics and cell densities were also examined.ResultsSignificant increases of neuronal density were observed in the hippocampus of DISC1 mice. DKI metrics such as mean kurtosis exhibited significant group differences in the caudate putamen (P = 0.015), cerebral cortex (P = 0.021), and hippocampus (P = 0.011). However, DKI metrics did not correlate with cell density. In contrast, significant positive correlation between density of neurons and the neurite density index of NODDI in the hippocampus was observed (r = 0.783, P = 0.007). Significant correlation between density of neurons and susceptibility (r = 0.657, P = 0.039), as well as between density of neuroglia and susceptibility (r = 0.750, P = 0.013), was also observed in the hippocampus.ConclusionThe imaging metrics derived from DKI were not sensitive specifically to cell density, while NODDI could provide diffusion metrics sensitive to density of neurons. The magnetic susceptibility values derived from the QSM method can serve as a sensitive biomarker for quantifying neuronal density.
An analysis of the fees and pending time correlation in Ethereum
Authors: de Azevedo Sousa José Eduardo , Oliveira Vinícius , Valadares Júlia , Dias Gonçalves Glauber , Moraes Villela Saulo , Soares Bernardino Heder , Borges Vieira Alex 
Published: July 2020

SummaryEthereum is a new blockchain‐based platform that is also capable of running smart contracts. Despite its increasing popularity, there is a lack of studies on characterizing this system, in special the fees paid by users and the respective delay to confirm the transactions, that is, the pending time. In this sense, we study the main features of Ethereum transactions and evaluate the common belief—for blockchain systems that rely on proof of work—that users who pay higher fees will have their transactions confirmed faster. Specifically, we collect information about 7.2 million of transactions in Ethereum and correlate their pending time to several fee‐related features. Moreover, we conduct our study evaluating different ranges of values for the features, such as default and unusual values adopted by users as well as clusters of users with similar behaviors. Our empirical analysis shows strong evidence that there is no clear correlation between fees‐related features and the pending time. Overall, we conclude from our investigation that transaction's features, including gas and gas price defined by users, cannot determine the pending time of transactions.
Changes in Cardiometabolic Risk Factors Before and After Gestational Diabetes: A Prospective Life‐Course Analysis in CARDIA Women
Authors: Catov Janet M. , Sun Baiyang , Bertolet Marnie , Snyder Gabrielle G. , Lewis Cora E. , Allen Norrina B. , Shikany James M. , Ingram Katherine H. , Appiah Duke , Gunderson Erica P. 
Published: July 2020

ObjectiveThis study hypothesized that both preconception and postchildbearing patterns of cardiometabolic risk factors may be different for women with gestational diabetes mellitus (GDM) compared with women without GDM.MethodsAmong 1,302 (51% black) women in the Coronary Artery Risk Development in Young Adults (CARDIA) study with births and followed for 30 years, this study evaluated changes in cardiometabolic factors (BMI, waist circumference [WC], lipids, blood pressure) during prechildbearing (prior to the first postbaseline birth) and postchildbearing periods (after the last birth) by GDM status using piecewise linear mixed models adjusted for sociodemographics, parity, and time‐varying covariates.ResultsCompared with women who did not develop GDM, weight and WC increases in women who developed GDM (n = 152, 12%) were faster (BMI difference: +0.12 kg/m2/y, P = 0.04; WC difference: +0.28 cm/y, P = 0.04) during the prechildbearing period, accounting for covariates. This translated to an average of 1.3 kg of excess weight gain across 4 years among women with subsequent GDM versus non‐GDM births. In contrast, slopes after childbearing did not differ by GDM status, nor were there other cardiometabolic differences.ConclusionsWomen with GDM exhibited an increasing prepregnancy pattern of weight gain and central adiposity. Absolute postchildbearing weight was also higher in GDM‐affected women, but the slope of gain after GDM was not.
Ghrelin Receptor Stimulation of the Lateral Parabrachial Nucleus in Rats Increases Food Intake but not Food Motivation
Authors: Bake Tina , Le May Marie V. , Edvardsson Christian E. , Vogel Heike , Bergström Ulrika , Albers Marjorie Nicholson , Skibicka Karolina P. , Farkas Imre , Liposits Zsolt , Dickson Suzanne L. 
Published: July 2020

ObjectiveThe lateral parabrachial nucleus (lPBN) in the brainstem has emerged as a key area involved in feeding control that is targeted by several circulating anorexigenic hormones. Here, the objective was to determine whether the lPBN is also a relevant site for the orexigenic hormone ghrelin, inspired by studies in mice and rats showing that there is an abundance of ghrelin receptors in this area.MethodsThis study first explored whether iPBN cells respond to ghrelin involving Fos mapping and electrophysiological studies in rats. Next, rats were injected acutely with ghrelin, a ghrelin receptor antagonist, or vehicle into the lPBN to investigate feeding‐linked behaviors.ResultsCuriously, ghrelin injection (intracerebroventricular or intravenous) increased Fos protein expression in the lPBN yet the predominant electrophysiological response was inhibitory. Intra‐lPBN ghrelin injection increased chow or high‐fat diet intake, whereas the antagonist decreased chow intake only. In a choice paradigm, intra‐lPBN ghrelin increased intake of chow but not lard or sucrose. Intra‐lPBN ghrelin did not alter progressive ratio lever pressing for sucrose or conditioned place preference for chocolate.ConclusionsThe lPBN is a novel locus from which ghrelin can alter consummatory behaviors (food intake and choice) but not appetitive behaviors (food reward and motivation).
Balanced physical properties for thermoplastic silicone vulcanizate‐based polymer composites containing functional filler
Authors: Pan Qinjun , Zhao Guojie , Deng Hua , Fu Qiang 
Published: July 2020

AbstractThermoplastic vulcanizates (TPVs) based on silicone rubber (SiR) and thermoplastic polyurethane (TPU), as a class of thermoplastic elastomers (TPEs), are extensively applied in various fields due to their excellent performance such as remarkable mechanical properties, easy processability, recyclability, and so on. However, it is quite difficult to incorporate functional fillers into thermoplastic silicone vulcanizate (TPSiV) without largely influencing their mechanical performance due to the rather high content of SiR and delicate balance between structure and properties. Herein, some efforts are made to introduce functional filler such as multiwall carbon nanotubes (MWCNTs) into TPSiVs. It is illustrated that with increasing MWCNTs loading in TPSiV from 0 to 5 wt%, the percolation threshold was achieved when the content of MWCNTs was 2%. Nevertheless, the tensile strength decreases from 3.95 to 1.84 MPa and elongation at break decreases from 260% to 25.6%, respectively. To fabricate TPSiV/carbon nanotubes (CNTs) composites with balanced properties, TPU based on polyester and hydrophobic silicon dioxide (SiO2) nanoparticles were introduced into these materials to enhance the mechanical properties. Through this method, TPSiV/TPU/SiO2/CNTs composites with different levels of electrical conductivity, while maintaining good mechanical properties and processability were fabricated. It is illustrated that TPU could provide extra space for the distribution of MWCNTs and SiO2 could strength these polymer blends. Such method is thought to provide an effective route for the preparation of functional polymer composites based on TPSiV.