bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wireless control of induced radiofrequency currents in active implantable medical devices during MRI
Authors: Acikel Volkan , Silemek Berk , Atalar Ergin 
Published: November 2019

PurposeTo introduce a prototype active implantable medical device (AIMD) for which the induced radiofrequency currents can be controlled wirelessly.MethodsThe modified transmission line method is used to formulate how the lead‐case impedance of an AIMD affects the temperature rise around the electrode. A prototype AIMD is designed with the aim of controlling the unwanted temperature rise around its electrode during an MRI examination by altering the impedance between the lead and the case of the implant. MRI experiments were conducted with this prototype implant, which also has a built‐in temperature sensor at its electrode. During the experiment, the implant’s lead‐case impedance was controlled using Bluetooth communication with a remote computer, and the lead tip temperature was recorded.ResultsTen different lead‐case impedance values and their corresponding tip temperature rises were examined during MRI experiments. The experimental results confirmed that the tip temperature rise can be controlled by varying the lead‐case impedance wirelessly.ConclusionThe feedback from the temperature at the AIMD tip, together with variable lead‐case impedance, enables control of the safety profile of the AIMD during an MRI examination.
Three‐dimensional simultaneous brain T1, T2, and ADC mapping with MR Multitasking
Authors: Ma Sen , Nguyen Christopher T. , Han Fei , Wang Nan , Deng Zixin , Binesh Nader , Moser Franklin G. , Christodoulou Anthony G. , Li Debiao 
Published: November 2019

PurposeTo develop a simultaneous T1, T2, and ADC mapping method that provides co‐registered, distortion‐free images and enables multiparametric quantification of 3D brain coverage in a clinically feasible scan time with the MR Multitasking framework.MethodsThe T1/T2/diffusion weighting was generated by a series of T2 preparations and diffusion preparations. The underlying multidimensional image containing 3 spatial dimensions, 1 T1 weighting dimension, 1 T2‐preparation duration dimension, 1 b‐value dimension, and 1 diffusion direction dimension was modeled as a 5‐way low‐rank tensor. A separate real‐time low‐rank model incorporating time‐resolved phase correction was also used to compensate for both inter‐shot and intra‐shot phase inconsistency induced by physiological motion. The proposed method was validated on both phantom and 16 healthy subjects. The quantification of T1/T2/ADC was evaluated for each case. Three post‐surgery brain tumor patients were scanned for demonstration of clinical feasibility.ResultsMultitasking T1/T2/ADC maps were perfectly co‐registered and free from image distortion. Phantom studies showed substantial quantitative agreement () with reference protocols for T1/T2/ADC. In vivo studies showed nonsignificant T1 (P = .248), T2 (P = .97), ADC (P = .328) differences among the frontal, parietal, and occipital regions. Although Multitasking showed significant differences of T1 (P = .03), T2 (P < .001), and ADC (P = .001) biases against the references, the mean bias estimates were small (ΔT1% < 5%, ΔT2% < 7%, ΔADC% < 5%), with all intraclass correlation coefficients greater than 0.82 indicating “excellent” agreement. Patient studies showed that Multitasking T1/T2/ADC maps were consistent with the clinical qualitative images.ConclusionThe Multitasking approach simultaneously quantifies T1/T2/ADC with substantial agreement with the references and is promising for clinical applications.
Continuous vs stepwise anal acoustic reflectometry: An improved technique for physiological measurement of anal sphincter function?
Authors: Heywood Nick A. , Nicholson James E. , Sharma Abhiram , Kiff Ed S. , Klarskov Niels , Telford Karen J. 
Published: November 2019

AbstractBackgroundAnal acoustic reflectometry (AAR) is a technique for measuring the physiological profile of the anal canal, primarily the internal anal sphincter. Evaluation of a new continuous method, recently developed for the urethra, would enable its future application for investigation of rectal reflexes.MethodsPatients aged 18 and over with fecal incontinence (FI) were included. Stepwise AAR parameters were compared with continuous opening pressure (Op, cmH2O), opening elastance (Oe, cmH2O/mm2), closing pressure (Cp, cmH2O), closing elastance (Ce, cmH2O/mm2), hysteresis (Hys, [%]), squeeze opening pressure (SqOp, cmH2O), and squeeze opening elastance (SqOe, cmH2O/mm2). Vaizey incontinence and Manchester Health Questionnaire scores were also collected.ResultsThirty‐two patients, 26 females were analyzed. Median age: 60 (range, 32‐75). Median AAR parameters of Op (37.50 vs 35.15, P = .031), Oe (1.31 vs 0.84, P < .0001), Ce (1.11 vs 0.88, P < .0001), Hys (37.75 vs 19.04, P < .0001), and SqOe (1.27 vs 1.06, P = .005) were significantly higher with the continuous method. Cp (22.70 vs 27.22, P = .003) is lower and SqOp (96.87 vs 59.47, P = .71) not significantly different. The continuous technique had superior repeatability between cycles for all AAR parameters except Oe, which was equivalent and continuous SqOp had a stronger negative correlation with Vaizey score than stepwise (−0.46, P = .009 vs −0.37, P = .038).ConclusionsThe differences seen between the two techniques are likely to be related to the rate of stretch. The continuous technique appears to represent a more physiological measurement of anal sphincter function than the stepwise technique particularly in the assessment of voluntary squeeze function.
A fast algorithm for a total variation based phase demodulation model
Authors: Brito‐Loeza Carlos , Legarda‐Saenz Ricardo , Martin‐Gonzalez Anabel 
Published: November 2019

AbstractIn this paper we introduce fast numerical algorithms for the solution of the model. For each variable, background illumination, amplitude modulation and phase map, we develop a fixed point method. Then, we write all three algorithms in the same framework and analyze their convergence rates, local smoothing factors by means of local Fourier analysis and present experimental evidence of their performance on synthetic and real world problems.
Laser polishing of Cu/PLA composite parts fabricated by fused deposition modeling: Analysis of surface finish and mechanical properties
Authors: Chen Lan , Zhang Xinzhou , Wang Yuan , Osswald Tim A. 
Published: November 2019

AbstractFused deposition modeling (FDM) technology decreases production time and cost in engineering industry, but with typical low surface quality. In this study, laser polishing was employed to improve surface quality of copper fiber/polylactide acid (Cu/PLA) composite parts fabricated by FDM. Surface roughness, surface morphology, dynamic mechanical analysis (DMA), and tensile properties were studied. The results showed that after laser polishing, the surface roughness was reduced by more than 91% (from 10.52 to 0.87 μm Sa) at the optimized parameters (the laser power of 5 W and the laser beam diameter of 200 μm). Laser polishing can effectively remove surface defects formed during FDM. DMA showed that the storage modulus, loss modulus, and glass transition temperature of Cu/PLA composites were significantly improved, because the Cu fibers and PLA matrix formed a strong interfacial adhesion after treatment. Moreover, the tensile strength and Young's modulus of the Cu/PLA composites sample also improved by laser polishing. The fracture morphologies were observed, and the possible strengthening mechanism was also discussed.
Isolation of mitraphylline from Uncaria tomentosa (Willd. ex Schult.) DC. barks and development of spectrophotometric method for total alkaloids determination in Cat's Claw samples
Authors: Gouvêa Marcos Martins , Pusceddu Breno Henrique , Pereira Netto Annibal Duarte , Peregrino Carlos Augusto de Freitas , Macedo Elizabeth Valverde , Mourão Samanta Cardozo , Marques Flávia Ferreira de Carvalho 
Published: November 2019

AbstractIntroductionThe usual quality control for Uncaria tomentosa (Willd. ex Schult.) DC. barks requires highly specific analytical standards and methods based on high‐performance liquid chromatography (HPLC), which impacts the costs of the analytical process and the final products.ObjectiveTo obtain an analytical reference standard of mitraphylline by isolation from U. tomentosa barks and develop a spectrophotometric method for determination of total alkaloids in samples of U. tomentosa.MethodologyAn alkaloid‐enriched extract was obtained by acid–base partition and mitraphylline was selectively precipitated using an 80:20 v/v toluene/hexane solution. The compound was characterised by HPLC‐UV/DAD (diode‐array detector), mass spectrometry, UV‐visible, infrared (IR) and 1H‐ and 13C‐nuclear magnetic resonance (NMR) spectroscopy. Sample preparation for the spectrophotometric method consisted of an extraction with boiling methanol (3 × 10 mL, 15 min), followed by a strong cation exchange solid phase extraction (SCX‐SPE) clean‐up.ResultsMitraphylline with a purity of 98% was isolated in 0.05% m/m yield. All characterisation results were in agreement with previous published data. The spectrophotometric method showed linear range between 0.40 and 20 μg/mL; limits of detection and quantification of 0.15 and 0.49 μg/mg, respectively; dispersion of results lower than 5% for repeatability and intermediate precision; statistically proven accuracy by comparison with reference values obtained by Soxhlet and an HPLC‐UV/DAD method; and robustness in relation to sample mass extracted and extraction time.ConclusionThe methods developed to obtain mitraphylline analytical standard from U. tomentosa barks and to determine total alkaloids by spectrophotometry provided a cheaper and faster quality control alternative for U. tomentosa samples.
Prevalence of mosaicism in uncultured chorionic villus samples after chromosomal microarray and clinical outcome in pregnancies affected by confined placental mosaicism
Authors: Lund Ida C. B. , Becher Naja , Christensen Rikke , Petersen Olav B. , Steffensen Ellen H. , Vestergaard Else M. , Vogel Ida 
Published: November 2019

AbstractObjectiveTo evaluate the prevalence of mosaicism in chorionic villus sampling (CVS) samples after chromosomal microarray (CMA) and clinical outcome of pregnancies affected by confined placental mosaicism.MethodWe retrieved all results from CMA, array‐based comparative genomic hybridization, on CVS samples from January 2011 to November 2017 from Central and North Denmark Regions. Mosaic results from uncultured chorionic villi, cytotrophoblasts and mesenchymal cells, after CVS and follow‐up on amniocytes, fetal tissue, or postnatal blood were studied and matched with clinical data from The Danish Fetal Medicine Database.ResultsPrevalence of mosaicism was 93 out of 2,288 (4.1%) CVS samples of which 17 (18.3%) concerned submicroscopic copy number variations (CNVs) <10 Mb. Follow‐up analyses were performed in 62 cases. True fetal mosaicism (TFM) was confirmed in 18.4% (7/38) when mosaicism involved whole chromosome aneuploidy and in 25.0% (6/24), when involving a CNV (P = .59). Median birth weight z‐score was higher in cases of confined placental mosaicism for a CNV (0.21) than cases involving whole chromosomes (−0.74) (P = .02).ConclusionPrevalence of mosaicism in CVS samples is higher after CMA on uncultured tissue than after conventional karyotyping on cultured tissue. The risk of TFM is equally high in cases of mosaicism for CNVs and whole chromosomes.
Pyrene‐based fluorescent supramolecular hydrogel: scaffold for nanoparticle synthesis
Authors: Kar Tanmoy , Patra Nitai 
Published: November 2019

AbstractThe present work illustrates the design and development of pyrene‐based fluorescent supramolecular hydrogel consisting of l‐phenylalanine residue as the linker and ethyleneoxy unit with free primary amine at C‐terminal. The gelator efficiently immobilized aqueous media, and the critical gelation concentration (CGC) was found at 2.8 mM of the compound. Interestingly, the presence of pyrene moiety in the structure made the hydrogel intrinsically fluorescent. The self‐aggregation properties of the thermo‐reversible hydrogel were investigated using different microscopic and spectroscopic techniques such as high‐resolution transmission electron microscopy (HRTEM), Fourier transform infrared (FTIR) spectroscopy, fluorescence spectroscopy, and X‐ray diffraction (XRD) spectroscopy. A balanced participation of noncovalent interactions like hydrogen bonding, π‐π stacking, and van der Waals interaction was identified as the driving force for gelation. Rheological experiments were performed to confirm the viscoelastic nature of the prepared hydrogel. Furthermore, primary amine (─NH2) group of hydrogelator was utilized for the in situ synthesis of silver nanoparticles (AgNPs) within the soft material under sunlight in the absence of any external reducing and stabilizing agent.
Acyl guanidine functional poly(2‐oxazoline)s as reactive intermediates and stimuli‐responsive materials
Authors: Van Guyse Joachim F. R. , Xu Xiaowen , Hoogenboom Richard 
Published: November 2019

ABSTRACTThe many postpolymerization modification opportunities of biocompatible poly(2‐alkyl/aryl‐2‐oxazoline)s (PAOx), such as thiol–ene/thiol–yne, azide–alkyne cycloadditions, amidation, and transesterification, are one of the most appealing features of this polymer class for its popularity in biomedicine. Inspired by recent reports on guanidine‐catalyzed transesterification and amidation reactions of methyl ester substrates, we explored the use of guanidines as a reactant for the modification of methyl ester functional PAOx, to obtain the respective acyl guanidines. The obtained acyl guanidines functional polymers display reactivity toward α‐haloketones, yielding imidazole functional PAOx. The obtained polymer structures are protonated in a broad pH range, and the acyl guanidine moiety is demonstrated to be a cleavable linker under basic conditions. © 2019 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2019, 57, 2616–2624
Peroxisome proliferator‐activated receptor gamma controls prostate cancer cell growth through AR‐dependent and independent mechanisms
Authors: Elix Catherine C. , Salgia Meghan M. , Otto‐Duessel Maya , Copeland Ben T. , Yoo Christopher , Lee Michael , Tew Ben Yi , Ann David , Pal Sumanta K. , Jones Jeremy O. 
Published: November 2019

AbstractBackgroundProstate cancer (PC) remains a leading cause of cancer mortality and the most successful chemopreventative and treatment strategies for PC come from targeting the androgen receptor (AR). Although AR plays a key role, it is likely that other molecular pathways also contribute to PC, making it essential to identify and develop drugs against novel targets. Recent studies have identified peroxisome proliferator‐activated receptor gamma (PPARγ), a nuclear receptor that regulates fatty acid (FA) metabolism, as a novel target in PC, and suggest that inhibitors of PPARγ could be used to treat existing disease. We hypothesized that PPARγ acts through AR‐dependent and independent mechanisms to control PC development and growth and that PPARγ inhibition is a viable PC treatment strategy.MethodsImmunohistochemistry was used to determine expression of PPARү in a cohort of patients with PC. Standard molecular techniques were used to investigate the PPARү signaling in PC cells as well a xenograft mouse model to test PPARү inhibition in vivo. Kaplan‐Meier curves were created using cBioportal.ResultsWe confirmed the expression of PPARү in human PC. We then showed that small molecule inhibition of PPARγ decreases the growth of AR‐positive and ‐negative PC cells in vitro and that T0070907, a potent PPARγ antagonist, significantly decreased the growth of human PC xenografts in nude mice. We found that PPARγ antagonists or small interfering RNA (siRNA) do not affect mitochondrial activity nor do they cause apoptosis; instead, they arrest the cell cycle. In AR‐positive PC cells, antagonists and siRNAs reduce AR transcript and protein levels, which could contribute to growth inhibition. AR‐independent effects on growth appear to be mediated by effects on FA metabolism as the specific FASN inhibitor, Fasnall, inhibited PC cell growth but did not have an additive effect when combined with PPARγ antagonists. Patients with increased PPARү target gene expression, but not alterations in PPARү itself, were found to have significantly worse overall survival.ConclusionsHaving elucidated the direct cancer cell effects of PPARγ inhibition, our studies have helped to determine the role of PPARγ in PC growth, and support the hypothesis that PPARγ inhibition is an effective strategy for PC treatment.
Topology and Interactions in the Photonic Creutz and Creutz‐Hubbard Ladders
Authors: Zurita Juan , Creffield Charles E. , Platero Gloria 
Published: November 2019

AbstractThe latest advances in the field of photonics have enabled the simulation of an increasing number of quantum models in photonic systems, turning them into an important tool for realizing exotic quantum phenomena. In this paper, different ways in which these systems can be used to study the interplay between flat band dynamics, topology, and interactions in a well‐known quasi‐1D topological insulator—the Creutz ladder—are suggested. First, a simple experimental protocol is proposed to observe the Aharonov–Bohm localization in the noninteracting system, and the different experimental setups that might be used for this are reviewed. The inclusion of a repulsive Hubbard‐type interaction term, which can give rise to repulsively bound pairs termed doublons, is then considered. The dynamics of these quasiparticles are studied for different points of the phase diagram, including a regime in which pairs are localized and particles are free to move. Finally, a scheme for the photonic implementation of a two‐particle bosonic Creutz‐Hubbard model is presented.
Does urban haze pollution inversely drive down the energy intensity? A perspective from environmental regulation
Authors: Hou Jian , Wang Jinghua , Chen Jiancheng , He Fang 
Published: November 2019

AbstractReducing energy intensity has consistently been advocated by the Chinese government in its effort to achieve sustainable development targets. Extant research suggests that energy consumption is often viewed as the primary cause of poor air quality. This paper investigates whether a certain threshold of environmental regulation causes the relationship to be reversed, that is, whether urban haze pollution could facilitate the reduction of energy intensity. On the basis of the city‐level panel data within the period of 2010–2015 in China, we systematically analyze the determinants of energy intensity and empirically investigate the dynamic threshold effects of environmental regulation on the association between urban haze pollution and energy intensity. The results suggest that serious haze pollution does reduce energy intensity, but it is dependent on environmental regulation. In particular, weak environmental regulation fails to optimize energy usage. With environmental regulation passing a critical threshold, urban haze pollution significantly decreases energy intensity. Therefore, the heterogeneous effect of environmental regulation across different regions should be considered. We find evidence that air pollution could inversely drive down energy intensity under a certain threshold level of environmental regulation. This result provides insights to policy makers and may help them design and implement more efficient urban environmental policies.
Real Time Detection of Hazardous Hydroxyl Radical Using an Electrochemical Approach
Authors: Huang Yujin , Sinha Ankita , Zhao Huimin , Dang Xueming , Zhang Yaobin , Quan Xie 
Published: November 2019

AbstractThe proposed work demonstrates an electrochemical strategy for hydroxyl radical (•OH) detection based on aptamer immobilized glassy carbon electrode (GCE). To enhance the sensitivity of the detection method, nitrogen doped porous carbon nanostructures (N−C) and gold nanoparticles (AuNPs) were used as signal amplifiers. During biosensor fabrication, thiolated DNA and 6‐mercaptohexanol (MCH) were self assembled on N−C/AuNPs modified GCE surface. The fabricated biosensor was characterized electrochemically by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) which justified its high electronic conductivity. The aptamer immobilized electrode (N−C/AuNPs/DNA/MCH/GCE) was immersed in Fenton's reagent where oxidative damage of DNA occurred due to generated •OH. The DNA damage was monitored by hexaammineruthenium(III) (Ru(NH3)63+) which acted as electrochemical probe for sensitive detection of •OH. Square wave voltammetry (SWV) was used for •OH biosensing using simple, sensitive and rapid strategy at the fabricated electrode.
Complementary Bifunctional Unique Properties of (α,β)‐PbO Nanoparticles for Efficient Catalysis and Adsorption for Water Remediation
Authors: Guin Jhimli Paul , Neogy Suman , Kumar Pranaw , Bhardwaj Yatender K. 
Published: November 2019

AbstractLead oxides (PbO) of same chemical composition, but different crystallographic properties have been developed for complementary catalytic ozonation (designated by [PbO]a) and adsorption (designated by [PbO]b) of a model dye, reactive red–120 (RR‐120) with highest possible efficiency beyond the state‐of‐the‐art of individual processes. The highest extent of decolouration (∼99% after 4 min) with
1.77×10−2 s−1 and mineralization (50% after 15 min) of RR‐120 at pH 10.5 was achieved by ozonation using 0.5 g/L catalyst [PbO]a consisting major fraction of α‐PbO phase (α‐PbO: β‐PbO∼4:1) in its crystal structure. Minimum adsorption of RR‐120 (∼7%) on catalyst's surface [PbO]a led to higher accessibility of O3 to free catalyst surface sites and helped to achieve highest efficiency of catalytic ozonation. On the other hand, adsorbent [PbO]b mainly consisting of β‐PbO phase (α‐PbO: β‐PbO∼1:4) with a fractional coexistence of α‐PbO phase showed excellent adsorption of RR‐120 (571 mg/g at 320 K) at pH 7.5, but it showed inferior efficiency in catalytic ozonation. Both the materials were found to be reusable and environmentally acceptable.
Synthesis of NH2‐MIL‐125/NH2‐MIL‐125‐P@TiO2 and Its Adsorption to Uranyl Ions
Authors: Xu Cheng , Zhang Wei , Chen Yuantao , Hu Guangzhuang , Liu Rong , Han Zhen 
Published: November 2019

AbstractPollution in nuclear industry is a difficult problem to solve. To solve this problem, we synthesized the NH2‐MIL‐125 modified materials (MIL‐125‐P@TiO2) by hydrothermal synthesis and also investigated the adsorption properties of uranyl ions. To improve the adsorbability of materials, we loaded titanium dioxide and phosphorylate it. The materials were characterized by means of XRD, SEM, infrared, thermogravimetric and XPS. The adsorption properties of uranyl ions on the two materials were studied by batch adsorption experiments. The results showed that the maximum adsorption capacity of modified material is 333.62 mg/g and 614.82 mg/g at 25 degrees Celsius by fitting the Langmuir model respectively, and the modified material has a better adsorption ability at 25 degrees Celsius with initial uranium concentration at 100 mg/L.