bluuebunny/crossref_metadata_2025_split huggingface dataset:
Double‐Tailed Single‐Head Amino Acid‐Based Chiral Cationic Amphiphilic Molecules: Synthesis, Characterization, and Physicochemical Properties
Authors: Olutas Elif Berna , Taskesen Teoman , Kartal Necla Büşra 
Published: August 2019

AbstractTwo double‐tailed single‐head amino acid‐based chiral cationic amphiphilic molecules, l‐aspartic acid hydrochloride dihexylester (L‐ADHE, C6–C6) and l‐aspartic acid hydrochloride dioctylester (L‐ADOE, C8–C8), were synthesized. 1H NMR, 13C NMR, and Fourier transform infrared (FT‐IR) were used to characterize the structures of the esters. Micellization, surface, and structural properties of L‐ADHE and L‐ADOE in aqueous solution were studied by means of a number of techniques including conductivity, pH, surface tension, density, zeta potential, and dynamic light scattering (DLS). The critical micelle concentration (CMC) of L‐ADHE and L‐ADOE were found to be very low compared with those of corresponding single‐tailed amino acid‐based amphiphilic molecules. The pKa values of L‐ADHE and L‐ADOE in aqueous solutions were determined via pH measurements, and it was observed that they had acidic properties giving low pKa values. The excellent adsorption behaviors at the air/water interface of L‐ADHE and L‐ADOE in aqueous medium were obtained, i.e. they efficiently lowered the surface tension of water at CMC down approximately to 24.3 and 23.4 mN m−1, respectively. From the density measurements, the volume change due to the micellization process for L‐ADOE was found to be quite high compared to L‐ADHE, i.e. about three times more. This result and the data obtained from the DLS revealed that the increase in aggregated structures of L‐ADOE may be due to vesicle formation. The dye solubilization study was performed by UV–vis absorption spectroscopy for L‐ADHE. Besides, the CMC value of L‐ADHE was also successfully determined without using any dye through UV–vis spectroscopy.
Frailty as a predictor of outcomes in patients undergoing head and neck cancer surgery
Authors: Goldstein David P. , Sklar Michael C. , de Almeida John R. , Gilbert Ralph , Gullane Patrick , Irish Jonathan , Brown Dale , Higgins Kevin , Enepekides Danny , Xu Wei , Su Jie , Alibhai Shabbir M.H. 
Published: August 2019

ObjectivesTo evaluate whether frailty and functional measures are predictors of perioperative complications and length of hospital stay (LOS) in patients undergoing head and neck cancer surgery.Study DesignProspective study.MethodsPatients 50 years and older undergoing major head and neck cancer surgery between 2011 and 2015 preoperatively completed Fried's Frailty Index, Barthel Index, Lawton‐Brody questionnaire and Vulnerable Elders Survey‐13. Primary outcome measures were postoperative complications and LOS, which were analyzed using multivariable logistic and linear regression models.ResultsThere were 274 patients recruited (105 aged 50–64 and 169 aged 65 and older). Of these, 119, 132, and 23 were defined as non‐frail, pre‐frail, and frail, respectively. Frailty score and functional measures were not predictors of overall complications. In multivariable models, frailty score (odds ratio [OR] = 1.36; 95% confidence interval [CI], 1.04–1.78, P = .025) was a predictor of medical complications and Clavien‐Dindo Grade III and higher complications independent of age and comorbidity. Higher frailty score (β = 1.07; 95% CI, 1.02–1.12, P = .0025) and less independence on the Lawton Brody (β = −0.08; 95% CI, −0.11 to −0.05, P < .001) and Barthel Index (β = −0.12; 95% CI, −0.19 to −0.06, P < .001) were predictors of increased LOS.ConclusionsFrailty was a predictor of type and severity of complications. Both frailty and measures of independence in activities of daily living were independent predictors of LOS. Frailty and functional assessment can help surgeons identify patients at risk of adverse postoperative outcomes and thus aid in counselling patients as well as identifying patients that may benefit from comprehensive geriatric assessment and targeted interventions.Level of EvidencePrognosis study 2bLaryngoscope, 130:E340–E345, 2020
Electromagnetic interference suppression in stacked patch antenna using complementary split ring resonator
Authors: Ramanujam Parthasarathy , Venkatesan P.G. Ramesh , Arumugam Chandrasekar 
Published: August 2019

AbstractA novel attempt is made by creating the stacked sequences of two different frequencies that provide the intended performance by suppressing the harmonic interferences between them. This electromagnetic interference (EMI) is suppressed in stacked system by incorporating the circular complementary split ring resonator (CCSRR) in the ground plane. The proposed system consists of two patch antennas operating at 2 GHz and 4 GHz with CCSRR for harmonic suppression. The lower rung antenna operates at 2 GHz fed by inset feeding and the top rung antenna operates at 4 GHz fed by coaxial feeding such that both radiators share a common ground plane. The lower rung antenna (2 GHz) has its first harmonic at 4.02 GHz with the magnitude of 11.5 dB that ensue an EMI to the other antenna operating at 4 GHz (top rung antenna in the stacked system). By introducing the CCSRR beneath the microstrip feed line (2 GHz), the EMI is suppressed. The simulated and measured results are in good agreement. Moreover, the proposed antenna finds its application in radar target scanning, narrow band channel selector, and low power narrow band wireless receivers.
Technical Note: Experimental characterization of the dose deposition in parallel MRI‐linacs at various magnetic field strengths
Authors: Begg Jarrad , Alnaghy Sarah J. , Causer Trent , Alharthi Thahabah , George Armia , Glaubes Laura , Dong Bin , Goozee Gary , Keall Paul , Jelen Urszula , Liney Gary , Holloway Lois 
Published: August 2019

PurposeDose deposition measurements for parallel MRI‐linacs have previously only shown comparisons between 0 T and a single available magnetic field. The Australian MRI‐Linac consists of a magnet coupled with a dual energy linear accelerator and a 120 leaf Multi‐Leaf Collimator with the radiation beam parallel to the magnetic field. Two different magnets, with field strengths of 1 and 1.5 T, were used during prototyping. This work aims to characterize the impact of the magnetic field at 1 and 1.5 T on dose deposition, possible by comparing dosimetry measured at both magnetic field strengths to measurements without the magnetic field.MethodsDose deposition measurements focused on a comparison of beam quality (TPR20/10), PDD, profiles at various depths, surface doses, and field size output factors. Measurements were acquired at 0, 1, and 1.5 T. Beam quality was measured using an ion chamber in solid water at isocenter with appropriate TPR20/10 buildup. PDDs and profiles were acquired via EBT3 film placed in solid water either parallel or perpendicular to the radiation beam. Films at surface were used to determine surface dose. Output factors were measured in solid water using an ion chamber at isocenter with 10 cm solid water buildup.ResultsBeam quality was within ±0.5% of the 0 T value for the 1 and 1.5 T magnetic field strengths. PDDs and profiles showed agreement for the three magnetic field strengths at depths beyond 20 mm. Deposited dose increased at shallower depths due to electron focusing. Output factors showed agreement within 1%.ConclusionDose deposition at depth for a parallel MRI‐linac was not significantly impacted by either a 1 or 1.5 T magnetic field. PDDs and profiles at shallow depths and surface dose measurements showed significant differences between 0, 1, and 1.5 T due to electron focusing.
MRI‐related FDA adverse event reports: A 10‐yr review
Authors: Delfino Jana G. , Krainak Daniel M. , Flesher Stephanie A. , Miller Donald L. 
Published: August 2019

PurposeTo provide an overview of the types of adverse events reported to the US Food and Drug Administration (US FDA) for magnetic resonance (MR) systems over a 10‐yr period.MethodsTwo reviewers independently reviewed adverse events reported to FDA for MR systems from 1 January 2008 to 31 December 2017 and manually categorized events into eight event types. Thermal events were further subcategorized by probable cause. Objects that became projectiles were also categorized.ResultsFDA received 1568 adverse event reports for MR systems between 1 January 2008 and 31 December 2017. This analysis included 1548 reports. Thermal events were the most commonly reported serious injury (59% of analyzed reports). Mechanical events — defined as slips, falls, crush injuries, broken bones, and cuts; musculoskeletal injuries from lifting or movement of the device — (11%), projectile events (9%), and acoustic events (6%) were also observed.ConclusionsAdverse events related to MR systems consistent with the known hazards of the MR environment continue to be reported to FDA. Increased awareness of the types of adverse events occurring for MR imaging systems is important for prevention.
Practical considerations for territorial perfusion mapping in the cerebral circulation using super‐selective pseudo‐continuous arterial spin labeling
Authors: Schollenberger Jonas , Figueroa C. Alberto , Nielsen Jon‐Fredrik , Hernandez‐Garcia Luis 
Published: August 2019

PurposeThis paper discusses several challenges faced by super‐selective pseudo‐continuous arterial spin labeling, which is used to quantify territorial perfusion in the cerebral circulation. The effects of off‐resonance, pulsatility, vessel movement, and label rotation scheme are investigated, and methods to maximize labeling efficiency and overall image quality are evaluated. A strategy to calculate the territorial perfusion fractions of individual vessels is proposed.MethodsThe effects of off‐resonance, label rotation scheme, and vessel movement on labeling efficiency were simulated. Two off‐resonance compensation strategies (multiphase prescan, field map), cardiac triggering, and vessel movement were studied in vivo in a group of 10 subjects. Subsequently, a territorial perfusion fraction map was acquired in 2 subjects based on the mean vessel labeling efficiency.ResultsMultiphase calibration provided the highest labeling efficiency (P = .002) followed by the field map compensation (P = .037) compared with the uncompensated acquisition. Cardiac triggering resulted in a qualitative improvement of the image and an increase in signal contrast between the perfusion territory and the surrounding tissue (P = .010) but failed to show a significant change in temporal and spatial SNR. The constant clockwise label rotation scheme yielded the highest labeling efficiency. Significant vessel movement (>2 mm according to simulations) was observed in 50% of subjects. The measured territorial perfusion fractions showed good agreement with anatomical data.ConclusionOptimized labeling efficiency resulted in increased image quality and accuracy of territorial perfusion fraction maps. Labeling efficiency depends critically on off‐resonance calibration, cardiac triggering, optimal label rotation scheme, and vessel location tracking.
Fat/water separation in k‐space with real‐valued estimates and its combination with POCS
Authors: Berglund Johan , Rydén Henric , Avventi Enrico , Norbeck Ola , Sprenger Tim , Skare Stefan 
Published: August 2019

PurposeTo develop reconstruction methods for improved image quality of chemical shift displacement‐corrected fat/water imaging combined with partial Fourier acquisition.TheoryFat/water separation in k‐space enables correction of chemical shift displacement. Modeling fat and water as real‐valued rather than complex improves the conditionality of the inverse problem. This advantage becomes essential for k‐space separation. In this work, it was described how to perform regularized fat/water imaging with real estimates in k‐space, and how fat/water imaging can be combined with partial Fourier reconstruction using Projection Onto Convex Sets (POCS).MethodsThe reconstruction methods were demonstrated on chemical shift encoded gradient echo and fast spin echo data from volunteers, acquired at 1.5 T and 3 T. Both fully sampled and partial Fourier acquisitions were made. Data was retrospectively rejected from the fully sampled dataset to evaluate POCS and homodyne reconstruction.ResultsFat/water separation in k‐space eliminated chemical shift displacement, while real‐valued estimates considerably reduced the noise amplification compared to complex estimates. POCS reconstruction could recover high spatial frequency information in the fat and water images with lower reconstruction error than homodyne. Partial Fourier in the readout direction enabled more flexible choice of gradient echo imaging parameters, in particular image resolution.ConclusionChemical shift displacement‐corrected fat/water imaging can be performed with regularization and real‐valued estimates to improve image quality by reducing ill‐conditioning of the inverse problem in k‐space. Fat/water imaging can be combined with POCS, which offers improved image quality over homodyne reconstruction.
Chronic low back pain beliefs and management practices in Africa: Time for a rethink?
Authors: Ahenkorah Josephine , Moffatt Fiona , Diver Claire , Ampiah Paapa Kwesi 
Published: August 2019

AbstractBackgroundChronic low back pain (CLBP) beliefs are important psychosocial risk factors affecting the occurrence and progression of CLBP. To address pain beliefs and implement recommended biopsychosocial approaches for CLBP management, an understanding of the beliefs of patients and healthcare professionals (HCPs), and also CLBP management practices, is necessary. A narrative review was conducted to explore CLBP beliefs and practices in African countries.MethodsTwo systematic searches were conducted using seven databases (MEDLINE, Embase, PsychInfo, CINAHL Plus, AMED, PubMed and Web of Science) with combined variations of the terms “Management”, “Guidelines”, “Chronic Low Back Pain”, “Beliefs”, “Patients”, “Healthcare Professionals” and “Africa”.ResultsFive studies and one standard treatment guideline document were included. No systematically developed African CLBP treatment guideline was found, although CLBP practices were identified in two African countries. CLBP management in African countries appears to be biomedically orientated. Only three research articles investigated the CLBP beliefs of patients in Africa, with none assessing HCP beliefs. Unhelpful CLBP beliefs (catastrophizing and fear avoidance) and biomedical thoughts about the causes of CLBP were identified. Unhelpful CLBP beliefs were associated with increased disability.ConclusionsManagement practices for CLBP in African countries appear to contradict recommended biopsychosocial management guidelines by developed countries and are not sufficiently documented. Research on CLBP beliefs and CLBP management practices in Africa is lacking. To enhance the uptake of biopsychosocial approach in Africa, research around CLBP beliefs in African CLBP patients and HCPs is required.
Hierarchically coordinated economic MPC plantwide control of mixed continuous‐batch units in process industries with application to a beet sugar plant
Authors: Mazaeda Rogelio , Cristea Smaranda P. , de Prada César 
Published: August 2019

SummaryThis paper deals with the optimal operation of processes that combine batch and continuous units. The proposed approach is based on a hierarchical architecture with two layers. The lower layer manages the optimal operation of the batch units in a noncentralized fashion, whereas the upper layer is concerned with the scheduling of the batch units and with their smooth integration with the continuous ones. The strategy has been applied to a challenging problem found at the interface of the fed‐batch crystallizers with the upstream evaporation section in beet sugar factories. The presented approach aims at designing a system that can effectively perform the plantwide economic optimization, specifically addressing the issue of energy efficiency, while complying with all process and operational constraints.
3D printing hybrid organometallic polymer‐based biomaterials via laser two‐photon polymerization
Authors: Balčiūnas Evaldas , Baldock Sara J , Dreižė Nadežda , Grubliauskaitė Monika , Coultas Sarah , Rochester David L , Valius Mindaugas , Hardy John G , Baltriukienė Daiva 
Published: August 2019

AbstractMaterials with microscale structures are gaining increasing interest due to their range of technical and medical applications. Additive manufacturing approaches to such objects via laser two‐photon polymerization, also known as multiphoton fabrication, enable the creation of new materials with diverse and tunable properties. Here, we investigate the properties of 3D structures composed of organometallic polymers incorporating aluminium, titanium, vanadium and zirconium. The organometallic polymer‐based materials were analysed using a variety of techniques including SEM, energy‐dispersive X‐ray spectroscopy, X‐ray photoelectron spectroscopy analysis and contact angle measurements and their biocompatibility was tested in vitro. Cell viability and mode of death were determined by 3‐(4,5‐dimethyl‐2‐thiazolyl)‐2,5‐diphenyl‐2H‐tetrazolium bromide (MTT) assay and acridine orange/ethidium bromide staining. Polymers incorporating Al, Ti and Zr supported cell adhesion and proliferation, and showed low toxicity in vitro, whereas the organometallic polymer incorporating V was shown to be cytotoxic. Inductively coupled plasma optical emission spectrometry suggested that leaching of the V from the organometallic polymer is the likely cause of this. The preparation of the organometallic polymers is straightforward and both simple 2D and complex 3D structures can be fabricated with ease. Resolution tests of the newly developed organometallic polymer incorporating Al show that suspended lines with widths down to 200 nm can be fabricated. We believe that the materials described in this work show promising properties for the development of objects with sub‐micron features for biomedical applications (e.g. biosensors, drug delivery devices, tissue scaffolds etc.). © 2019 The Authors. Polymer International published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.
Gelation via cationic chelation/crosslinking of acrylic‐acid‐based polymers
Authors: Magami Saminu M , Williams Rhodri L 
Published: August 2019

AbstractThe gelation characteristics of acrylic‐acid‐based polymers in the presence of a range of cationic species, namely Ca2+, Mg2+ and Al3+, were investigated using in situ rheological measurements during photo‐polymerisation. Fourier transform mechanical spectroscopy was used to identify the gel point, using the Winter–Chambon criteria which allow the gel point to be pinpointed by establishing the sample spanning network and quantitatively determining stiffness, relaxation exponent, gel stiffness and fractal dimensions. The results showed that the gelation processes were greatly influenced by the type of cationic species that was used in the syntheses. At the gel point, more open network clusters were formed when Al3+ cations were used instead of Ca2+ cations or Mg2+ cations, all relating to chloride salts. Although the concentrations of the chelating/crosslinking aluminium species affected the kinetics of the gelation, the critical gel characteristics were hardly affected. Also the solubility of the chosen aluminium salt was shown to dictate the crosslinking rates and the properties of the critical gels. The extents of the reactions and the types of network formed at the gel point and beyond indicated that reactions between the Al3+ ions and COOH sites, from growing poly(acrylic acid) molecular chains, differ from those exhibited by Mg2+ and Ca2+ ions. All of the chelation/crosslinking reactions met the criteria of low mutation number (Nmu), such that in all cases Nmu ≪ 1. © 2019 Society of Chemical Industry
Protein Paucimannosylation Is an Enriched N‐Glycosylation Signature of Human Cancers
Authors: Chatterjee Sayantani , Lee Ling Y. , Kawahara Rebeca , Abrahams Jodie L. , Adamczyk Barbara , Anugraham Merrina , Ashwood Christopher , Sumer‐Bayraktar Zeynep , Briggs Matthew T. , Chik Jenny H. L. , Everest‐Dass Arun , Förster Sarah , Hinneburg Hannes , Leite Katia R. M. , Loke Ian , Möginger Uwe , Moh Edward S. X. , Nakano Miyako , Recuero Saulo , Sethi Manveen K. , Srougi Miguel , Stavenhagen Kathrin , Venkatakrishnan Vignesh , Wongtrakul‐Kish Katherine , Diestel Simone , Hoffmann Peter , Karlsson Niclas G. , Kolarich Daniel , Molloy Mark P. , Muders Michael H. , Oehler Martin K. , Packer Nicolle H. , Palmisano Giuseppe , Thaysen‐Andersen Morten 
Published: August 2019

AbstractWhile aberrant protein glycosylation is a recognized characteristic of human cancers, advances in glycoanalytics continue to discover new associations between glycoproteins and tumorigenesis. This glycomics‐centric study investigates a possible link between protein paucimannosylation, an under‐studied class of human N‐glycosylation [Man1‐3GlcNAc2Fuc0‐1], and cancer. The paucimannosidic glycans (PMGs) of 34 cancer cell lines and 133 tissue samples spanning 11 cancer types and matching non‐cancerous specimens are profiled from 467 published and unpublished PGC‐LC‐MS/MS N‐glycome datasets collected over a decade. PMGs, particularly Man2‐3GlcNAc2Fuc1, are prominent features of 29 cancer cell lines, but the PMG level varies dramatically across and within the cancer types (1.0–50.2%). Analyses of paired (tumor/non‐tumor) and stage‐stratified tissues demonstrate that PMGs are significantly enriched in tumor tissues from several cancer types including liver cancer (p = 0.0033) and colorectal cancer (p = 0.0017) and is elevated as a result of prostate cancer and chronic lymphocytic leukaemia progression (p < 0.05). Surface expression of paucimannosidic epitopes is demonstrated on human glioblastoma cells using immunofluorescence while biosynthetic involvement of N‐acetyl‐β‐hexosaminidase is indicated by quantitative proteomics. This intriguing association between protein paucimannosylation and human cancers warrants further exploration to detail the biosynthesis, cellular location(s), protein carriers, and functions of paucimannosylation in tumorigenesis and metastasis.
Synthesis and properties of a high‐performance pyrimidine‐containing self‐catalyzed phthalonitrile polymer
Authors: Xu Jianjun , Wang Haifeng , Zhang Zhenjiang , Yang Kaixiong , Li Peixian , Chen Xinggang , Yu Xiaoyan , Naito Kimiyoshi , Zhang Qingxin 
Published: August 2019

ABSTRACTA self‐catalytic monomer of phthalonitrile, 2‐amino‐4,6‐bis[3‐(3,4‐dicyano‐phenoxy)phenoxy] pyrimidine (ACPP), was synthesized by a one‐pot method with resorcinol, 2‐amino‐4,6‐dichloropyrimidine, and 4‐nitrophthalonitrile. The chemical structure of the ACPP monomer was characterized by Fourier transform Infrared spectroscopy (FTIR) and nuclear magnetic resonance spectroscopy. The curing behavior of ACPP monomer was studied by differential scanning calorimetric, which indicated that the ACPP monomer had a low melting point (84 °C) and revealed an autocatalytic reaction and tremendously wide processing window (193 °C). Wide‐angle X‐ray diffraction (WAXD) and FTIR analyses were employed to explore the microstructure of the ACPP polymers. The properties of the three polymers with different curing procedures were investigated, which implied that the ACPP polymers exhibited excellent thermal stability, high modulus, superior glass‐transition temperature (Tg > 400 °C), and low water absorption with the increase in curing extent. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2287–2294