bluuebunny/crossref_metadata_2025 huggingface dataset:
Shear‐induced morphology changes in N,N′‐dimethylacetamide/lithium chloride pretreated cellulose
Authors: R Lavanya , I Clara , N Natchimuthu
Published: January 2017

A new mechanochemical treatment was performed on cellulose with the objective of modifying its morphology, reducing its crystallinity, and enabling better dissolution. Cellulose treated with N,N′‐dimethylacetamide (DMAc)/lithium chloride (LiCl) was subjected to shear with natural rubber as the carrier and shear‐transfer medium. When cellulose was subjected to such a mechanochemical treatment, significant changes in its surface morphology and a decrease in crystalline index were observed. The dissolution of the mechanochemically treated cellulose samples in DMAc/LiCl was found to be better compared with the dissolution of samples subjected to either mechanical shear or the chemical action of DMAc/LiCl independently. Chemical interactions between DMAc/LiCl and cellulose were enhanced synergistically under shear‐induced deformation. When shear alone was used in the absence of a DMAc/LiCl treatment, changes in the morphology, crystalline index, and dissolution were found to be negligible. The shear‐induced cellulose samples were characterized with Fourier transform infrared spectroscopy, X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, and thermogravimetric analysis. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44809.
Mechanical, thermomechanical, and creep performance of CNT embedded epoxy at elevated temperatures: An emphasis on the role of carboxyl functionalization
Authors: Rathore Dinesh Kumar , Prusty Rajesh Kumar , Ray Bankim Chandra
Published: January 2017

In contrast to polymeric composites, the role of interface/interphase has been widely acknowledged to govern their overall properties and performance. Environmental temperature has substantial effects on the interfacial durability of polymer nanocomposites. In this regard, present investigation has been carried out to study the mechanical performance of pristine (UCNT) and carboxylic functionalized CNT (FCNT) embedded epoxy nanocomposites under different elevated temperatures. Higher flexural strength and modulus of FCNT‐EP nanocomposite were recorded over UCNT‐EP and neat epoxy at room temperature environment. Flexural testing at elevated temperatures revealed a higher rate of strength degradation in polymer nanocomposites over neat epoxy. Postfailure analysis of specimens has been conducted to understand the alteration in failure micro‐mechanisms upon UCNTs and FCNTs addition in epoxy. Variation in viscoelastic properties with temperature has been studied from dynamic mechanical thermal analysis and significant reduction in glass transition temperature (Tg) is observed for nanocomposites. In the studied temperature and stress combinations, FCNT‐EP nanocomposites exhibited better creep resistance over UCNT‐EP and neat epoxy. Room temperature strengthening, elevated temperature strength degradations, improved creep resistance and reduction in Tg in nanocomposites over neat polymer have been discussed in terms of dynamic nature and gradient structure of CNT/epoxy interphase. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44851.
Fabrication of electrospun antioxidant nanofibers by rutin‐pluronic solid dispersions for enhanced solubility
Authors: Lee Il Woo , Li Jinglei , Chen Xiguang , Park Hyun Jin
Published: January 2017

In this study, solid dispersions (SDs) and electrospinning combined methods were used to increase the bioavailability and solubility of a water insoluble drug. Pullulan (PUL) nanofibers containing rutin‐Pluronic SDs (PUL&RU@PF) were fabricated by electrospinning. Rutin was efficiently loaded with Pluronic SDs using a facile mixing method and the prepared SDs indicated that 4% w/v Pluronic concentration provided the optimal drug loading efficiency. Scanning electron microscopy (SEM) verified that the morphology of the complex nanofibers had a uniformly smooth surface with a porous structure. The amorphous state of rutin was examined by XRD and DSC. Moreover, rutin in the electrospun PUL‐rutin‐Pluronic complex structure displayed a fast release profile and equivalent antioxidant ability compared to that of raw rutin. In conclusion, PUL&RU@PF may be a promising alternative for enhanced solubility and UV stability with remaining rutin's inherent antioxidant ability. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44859.
Synthesis of immobilized poly(vinyl alcohol)/cyclodextrin eco‐adsorbent and its application for the removal of ibuprofen from pharmaceutical sewage
Authors: Shang Songmin , Chiu Ka‐Lok , Jiang Shouxiang
Published: January 2017

In this project, immobilized poly(vinyl alcohol)/cyclodextrin eco‐adsorbent was synthesized and its application for the removal of ibuprofen from pharmaceutical sewage was investigated. Our eco‐adsorbent was prepared via solution blending of (2‐hydroxypropyl)‐β‐cyclodextrin (HPBCD) and poly(vinyl alcohol) (PVA), followed by glutaraldehyde treatment. The obtained eco‐adsorbent is in the form of transparent film and is very easy to handle. Its FTIR and thermal analysis results show that it is well crosslinked, preventing it from dissolving in sewage. Its adsorption rate is well described by the pseudo‐second‐order kinetic model. Its maximum ibuprofen uptake is 2.56 mg/g and is higher than those of mesoporous silica, volcanic soil, and zeolite. More than 90% of adsorbed IB molecules are desorbed after soaking the consumed adsorbent in 5% ethanol‐water solution for an hour. This implies that our eco‐adsorbent can be rapidly regenerated via simple soaking procedure, significantly reducing its operational cost during practical application. As a result, it would be a potential adsorbent for the treatment of pharmaceutical sewage. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44861.
Time‐dependent changes in the suppressive effect of electric field exposure on immobilization‐induced plasma glucocorticoid increase in mice
Authors: Harakawa Shinji , Hori Takuya , Inoue Noboru , Suzuki Hiroshi
Published: January 2017

We recently reported that increased glucocorticoid (GC) levels in immobilized mice were suppressed by exposure to a 50‐Hz electric field (EF) in kV/m‐dependent and exposure duration‐dependent manners. Here, we characterized time‐dependent changes in the effect of EF exposure in immobilized mice. Using control, EF‐alone, immobilization‐alone, and co‐treated groups, plasma GC levels, and blood properties were first measured (0–60 min) to observe changes induced by each treatment and measured again (60–120 min) to assess recovery from each treatment. The 50‐Hz, 10‐kV/m EF was formed in a parallel plate electrode. Co‐treated mice were exposed to the EF for 60 min for the first measurement and were immobilized for the second half (30–60 min) of the EF exposure period. Plasma GC levels did not change significantly over time in the control and EF‐alone groups. GC levels in the immobilization‐alone and co‐treated groups increased after immobilization, peaking 30 min after the start of immobilization and then decreasing gradually; however, the GC peak was lower in the co‐treated group than in the immobilization‐alone group (P < 0.05 at 50 and P < 0.001 at 60 min). Red blood cell counts, hemoglobin levels, and hematocrit values increased after immobilization but were not affected by the EF. Our findings indicate that the EF did not shift the peak of the time‐dependent increase in plasma GC levels in immobilized mice but simply reduced it. Bioelectromagnetics. 38:272–279, 2017. © 2017 Wiley Periodicals, Inc.
Pulsed magnetic field enhances therapeutic efficiency of mesenchymal stem cells in chronic neuropathic pain model
Authors: Mert Tufan , Kurt Akif Hakan , Altun İdiris , Celik Ahmet , Baran Furkan , Gunay Ismail
Published: January 2017

Cell‐based or magnetic field therapies as alternative approaches to pain management have been tested in several experimental pain models. The aim of this study therefore was to investigate the actions of the cell‐based therapy (adipose tissue derived mesenchymal stem cells; ADMSC) or pulsed magnetic field (PMF) therapy and magneto‐cell therapy (combination of ADMSC and PMF) in chronic constriction nerve injury model (CCI). The actions of individual ADMSC (route dependent [systemic or local], time‐dependent [a day or a week after surgery]), or PMF and their combination (magneto‐cell) therapies on hyperalgesia and allodynia were investigated by using thermal plantar test and a dynamic plantar aesthesiometer, respectively. In addition, various cytokine levels (IL‐1β, IL‐6, and IL‐10) of rat sciatic nerve after CCI were analyzed. Following the CCI, both latency and threshold significantly decreased. ADMSC or PMF significantly increased latencies and thresholds. The combination of ADMSC with PMF even more significantly increased latency and threshold when compared with ADMSC alone. However, ADMSC‐induced decrease in pro‐inflammatory or increase in anti‐inflammatory cytokines levels were partially prevented by PMF treatments. Present findings may suggest that both cell‐based and magnetic therapies can effectively attenuate chronic neuropathic pain symptoms. Combined magneto‐cell therapy may also efficiently reverse neuropathic signs. Bioelectromagnetics. 38:255–264, 2017. © 2017 Wiley Periodicals, Inc.
A new case of “de novo” BRCA1 mutation in a patient with early‐onset breast cancer
Authors: Antonucci Ivana , Provenzano Martina , Sorino Luca , Rodrigues Melissa , Palka Giandomenico , Stuppia Liborio
Published: January 2017

Key Clinical Message

Most of the de novo BRCA1/2 mutations have been identified in patients with early‐onset breast cancer and without family history of the disease. The identification of these alterations could play a prominent role in the prevention and treatment strategies and may influence clinical management of patients.
A case of congenital dyserythropoietic anemia type IV
Authors: de‐ la‐ Iglesia‐ Iñigo Silvia , Moreno‐Carralero María‐Isabel , Lemes‐Castellano Angelina , Molero‐Labarta Teresa , Méndez Manuel , Morán‐Jiménez María‐José
Published: January 2017

Key Clinical Message

Congenital dyserythropoietic anemias (CDAs) are displayed by ineffective erythropoiesis. The wide variety of phenotypes observed in CDA patients makes differential diagnosis difficult; identification of the genetic variants is crucial in clinical management. We report the fifth case of a patient with unclassified CDAs, after genetic study, with CDA type IV.
Highly Active PdCu Alloy Nanowire Network Electrocatalyst for Ethanol and Methanol Electrooxidation
Authors: Chen Rongna , Sun Muxue , Pang Guigui , Zhou Junshuang , Hou Li , Gao Faming
Published: January 2017

PdCu alloy nanowire networks (NNWs) with tunable compositions are synthesized. Electrooxidaton catalytic measurements prove that the as‐prepared PdCu NNWs represent a predominant catalyst for methanol and ethanol electrooxidation reactions in alkaline medium. With increasing copper content, the electrocatalytic activity of the catalytic materials to ethanol and methanol was significantly increased. Pd27Cu73 NNW‐modified electrodes display superior catalytic activity (8300 A gPd−1) toward the ethanol electrooxidation compared to commercial Pd/C‐modified electrodes (700 A gPd−1). PdCu NNWs have great potential as electrocatalysts for fuel cells.
Kinetic studies on the liquid‐phase catalytic oxidation of 4‐methyl guaiacol to vanillin
Authors: Ma Qiyi , Liu Kejing , Mao Jianyong , Chen Kexian , Liang Cheng , Yao Jia , Chen Zhirong , Li Haoran
Published: January 2017

Kinetic studies on the catalytic oxidation of 4‐methyl guaiacol using an ether intermediate towards vanillin in an agitator bubbling reactor were presented. The reaction was catalyzed by N,N′‐ethylenebis(acetylacetoniminato)‐cobalt(II) hexafluorophosphoric pyridinium (Co‐[Salen‐Py][PF6]2) under strong alkaline conditions with molecular oxygen as the terminal oxidant. The reaction scheme was demonstrated by a detailed analysis of the products distribution and control experiments. The intrinsic kinetics were explored based on our proposed p‐benzoquinone methide mechanism, which revealed that the oxidation rate was determined by the oxidation of phenoxyl anion to phenoxyl radical catalyzed by LCo3+(O2·) (L = [Salen‐Py][PF6]2). The kinetic experiments were performed under a mass transfer‐reaction condition due to the inevitable mass transfer resistance involved. Pseudo‐first order fast reactions were observed for both steps of the consecutive reactions based on the calculated physical and mass transfer parameters. The intrinsic kinetic equations for the first and second steps can be written as and , respectively, which are well in accordance with the mechanism. These conclusions are expected to give a clue for the mechanistic study, kinetic investigation, reaction optimization, and catalyst design for the oxidation of various p‐cresols.
Clinical Considerations for Oncolytic Viral Therapies: A Regulatory Perspective
Authors: Liu K
Published: January 2017

The US Food and Drug Administration (FDA) approved the first oncolytic viral therapy (OVT), Imlygic (talimogene laherparepvec), in October 2015 for the local treatment of unresectable cutaneous, subcutaneous, and nodal lesions in patients with melanoma recurrent after initial surgery, although talimogene has not been shown to improve overall survival or have an effect on visceral metastases.
Intensive treatment for adults with anorexia nervosa: The cost of weight restoration
Authors: Guarda Angela S. , Schreyer Colleen C. , Fischer Laura K. , Hansen Jennifer L. , Coughlin Janelle W. , Kaminsky Michael J. , Attia Evelyn , Redgrave Graham W.
Published: January 2017

Objective

Weight restoration in anorexia nervosa (AN) is associated with lower relapse risk; however rate of weight gain and percent of patients achieving weight restoration (BMI ≥ 19 at discharge) vary among treatment programs. We compared both cost/pound of weight gained and cost of weight restoration in a hospital‐based inpatient (IP)‐partial hospitalization (PH) eating disorders program to estimates of these costs for residential treatment.

Method

All adult first admissions to the IP‐PH program with AN (N = 314) from 2003 to 2015 were included. Cost of care was based on hospital charges, rates of weight gain, and weight restoration data. Results were compared with residential treatment costs extracted from a national insurance claims database and published weight gain data.

Results

Average charge/day in the IP‐PH program was $2295 for IP and $1567 for PH, yielding an average cost/pound gained of $4089 and $7050, respectively, with 70% of patients achieving weight restoration. Based on published mean weight gain data and conservative cost/day estimates, residential treatment is associated with higher cost/pound, and both higher cost and lower likelihood of weight restoration for most patients.

Discussion

The key metrics used in this study are recommended for comparing the cost‐effectiveness of intensive treatment programs for patients with AN.
The effects of restaurant menu calorie labeling on hypothetical meal choices of females with disordered eating
Authors: Haynos Ann F. , Roberto Christina A.
Published: January 2017

Concerns have been raised that obesity public policy measures may have harmful effects on individuals with eating disorders. However, little research has investigated this topic. We examined the impact of a popular obesity public policy, menu calorie labeling, on hypothetical food choices of women with disordered eating. Seven hundred sixteen adult females completed an online survey in which they were randomly assigned to receive a restaurant menu with or without calorie information listed. Participants selected foods representative of a meal they would choose to consume and answered questions on restaurant ordering and menu labeling. Participants completed the Eating Disorder Examination Questionnaire (Fairburn & Beglin, ) to assess global eating pathology. Diagnoses of anorexia nervosa (AN), bulimia nervosa (BN), and binge‐eating disorder (BED) were also derived from this measure. Generalized linear modeling examined the impact of menu label condition, disordered eating, and the menu label by disordered eating interaction on hypothetical food selection and related variables. When disordered eating was examined continuously, menu labeling did not differentially affect food selections of those with elevated disordered eating (p = .45). However, when examined by eating disorder diagnosis, participants with AN or BN ordered significantly fewer (p < .001) and participants with BED ordered significantly more (p = .001) calories in the menu label versus no label condition. Menu labeling may decrease the calories ordered among individuals with AN or BN and increase calories ordered among individuals with BED.
Daphniainhibits the emergence of spatial pattern in a simple consumer–resource system
Authors: Betini Gustavo S. , Avgar Tal , McCann Kevin S. , Fryxell John M.
Published: January 2017

Spatial self‐organization can occur in many ecosystems with important effects on food web dynamics and the maintenance of biodiversity. The consumer–resource interaction is known to generate spatial patterning, but only a few empirical studies have investigated the effect of the consumer on resource distribution. Here we report results from a large aquatic mesocosm experiment used to investigate the effect of the consumerDaphnia magnaon the distribution of its resource, the green algaeChlorella vulgaris. We maintained large tanks with capacity for 26 ,000 L with either algae or both algae andDaphniain different temperature conditions. We found that the presence ofD. magnainhibited spatial structure in algal distribution that arose as a consequence of increasing temperature. We conjecture that this homogenization effect might be caused by a combination of high mobility combined with high rates of algal consumption byDaphnia. Our study emphasizes the importance of both local constraints on growth and behavioral responses in either promoting or suppressing spatial self‐organization in natural populations.
Bottom‐up and top‐down controls on coral reef sponges: disentangling within‐habitat and between‐habitat processes
Authors: Wulff Janie
Published: January 2017

Polarized debates about top‐down vs. bottom‐up control have given way to more nuanced understanding of control by both resources and consumers in many systems, but coral reef sponges have recently been asserted to differ from other groups in being controlled exclusively top‐down. This assertion has been countered by reports of exclusively bottom‐up control, with both conclusions based on studies of the same species. Accelerating deterioration of coral reefs motivates knowing the contexts in which either consumers or nutrients or both control key ecosystem role players like sponges. Accordingly, genotype‐ and size‐controlled individuals of 12 common Caribbean reef sponge species were transplanted, in the field, into five circumstances differing in predators, competitors, and the picoplankton consumed by sponges. Growth and survival of the experimental transplants for periods of 1–9 yr revealed context‐dependent control of sponges. Primary control of growth was bottom‐up, with more picoplankton resulting in consistent and sustained higher growth rates for all 12 of these ecologically and phylogenetically diverse species. Top‐down control was not detected within‐habitat, on the coral reef. However, between‐habitat control was by predation and competition, with reef sponges excluded from adjacent seagrass meadows by spongivorous starfish, and excluded from mangrove prop roots by faster‐growing mangrove sponges. These results highlight the strong importance of experimental design details that consider behavior idiosyncrasies, sufficiently long time scales, and appropriate division of species into categories. Diametrically opposite results from studies of the same species also illustrate the inherently greater difficulty of detecting bottom‐up processes and the importance of distinguishing within‐habitat vs. between‐habitat patterns and processes.
A Hierarchically Porous Hollow Structure of Layered Bi2TiO4F2 for Efficient Photocatalysis
Authors: Lei Shuijin , Gao Xijie , Cheng Di , Fei Linfeng , Lu Wei , Zhou Jianliang , Xiao Yanhe , Cheng Baochang , Wang Yu , Huang Haitao
Published: January 2017

Research into bismuth compounds has been greatly stimulated by their extensive applications in photocatalysis, which is a promising technique for environmental decontamination. In this research, Bi2TiO4F2 hierarchically porous hollow spheres are successfully prepared by a simple solvothermal method. The X‐ray powder diffraction pattern shows that the sample has an Aurivillius‐type layered perovskite structure. The electron microscopy analyses reveal that the obtained hierarchical hollow spheres have a porous surface composed of interlaced nanoplates. A mechanism for the formation and growth of the hollow spheres is proposed on the basis of time‐dependent evolution experiments. The band gap of the prepared Bi2TiO4F2 sample is measured to be ca. 2.85 eV, and its photocatalytic activity and mechanisms are explored systematically. The results demonstrate that the product can serve as an effective catalyst for the degradation of rhodamine B and methyl orange through photocatalytic reactions under irradiation with UV light and can also be used in the visible‐light degradation of rhodamine B through the photosensitization process.
Monitoring of the stability of cocaine and some metabolites in water and oral fluid by a newly developed CE method
Authors: D'Elia Valentina , Calcerrada Matias , Montalvo Gemma , García Ruiz Carmen
Published: January 2017

A new CE method was here developed, in order to study the stability of cocaine and some of its metabolites in water and in oral fluid. At first, standard mixtures of cocaine (COC), benzoylecgonine (BE) and cocaethylene (COET) in water were used to study the optimal CE parameters to separate the three compounds. Voltage, sample temperature and pH were investigated, and 25 kV, 25°C and a pH of 4.7 were selected to achieve the best separation. The stability of the three compounds in water and oral fluid was then monitored by applying the previously developed method. Three different storage temperatures (8, 25 and 37°C) were selected and analyses during a week were performed. A decrease of COC and COET peak areas and an increase of BE peak area were observed over time at 25 and 37°C. In addition, in oral fluid, the presence of enzymes and other proteins, and the differences in the molecular structures between COC and COET, caused a stronger degradation of the first compound. Instead, when samples were stored at a low temperature (8°C), the peak areas of the compounds did not vary. Thus, the use of this storage temperature is recommended, above all when sample must be analyzed after a relatively long time.
Enhancement of dielectrophoresis using fractal gold nanostructured electrodes
Authors: Koklu Anil , Sabuncu Ahmet C. , Beskok Ali
Published: January 2017

Dielectrophoretic motions of Saccharomyces cerevisiae (yeast) cells and colloidal gold are investigated using electrochemically modified electrodes exhibiting fractal topology. Electrodeposition of gold on electrodes generated repeated patterns with a fern‐leaf type self‐similarity. A particle tracking algorithm is used to extract dielectrophoretic particle velocities using fractal and planar electrodes in two different medium conductivities. The results show increased dielectrophoretic force when using fractal electrodes. Strong negative dielectrophoresis of yeast cells in high‐conductivity media (1.5 S/m) is observed using fractal electrodes, while no significant motion is present using planar electrodes. Electrical impedance at the electrode/electrolyte interface is measured using impedance spectroscopy technique. Stronger electrode polarization (EP) effects are reported for planar electrodes. Decreased EP in fractal electrodes is considered as a reason for enhanced dielectrophoretic response.
The human subthalamic nucleus and globus pallidus internus differentially encode reward during action control
Authors: Justin Rossi Peter , Peden Corinna , Castellanos Oscar , Foote Kelly D. , Gunduz Aysegul , Okun Michael S.
Published: January 2017

The subthalamic nucleus (STN) and globus pallidus internus (GPi) have recently been shown to encode reward, but few studies have been performed in humans. We investigated STN and GPi encoding of reward and loss (i.e., valence) in humans with Parkinson's disease. To test the hypothesis that STN and GPi neurons would change their firing rate in response to reward‐ and loss‐related stimuli, we recorded the activity of individual neurons while participants performed a behavioral task. In the task, action choices were associated with potential rewarding, punitive, or neutral outcomes. We found that STN and GPi neurons encode valence‐related information during action control, but the proportion of valence‐responsive neurons was greater in the STN compared to the GPi. In the STN, reward‐related stimuli mobilized a greater proportion of neurons than loss‐related stimuli. We also found surprising limbic overlap with the sensorimotor regions in both the STN and GPi, and this overlap was greater than has been previously reported. These findings may help to explain alterations in limbic function that have been observed following deep brain stimulation therapy of the STN and GPi. Hum Brain Mapp 38:1952–1964, 2017. © 2017 Wiley Periodicals, Inc.
Influence of carrageenan on cytokine production and cellular activity of mouse peritoneal macrophages and its effect on experimental endotoxemia
Authors: Kalitnik A. A. , Karetin Y. A. , Kravchenko A. O. , Khasina E. I. , Yermak I. M.
Published: January 2017

The in vivo effect of κ/β‐carrageenan isolated from the red alga Tichocarpus crinitus on cytokine synthesis and cellular activity of murine peritoneal macrophages and also the protective effect of polysaccharides in LPS‐induced endotoxemia in mice was studied. It was established that κ/β‐carrageenan given orally at a dose of 100 mg/kg stimulates the induction of anti‐inflammatory cytokines (IL‐10) in mouse blood cells by more than 2.5‐fold compared with control, with no effect on pro‐inflammatory cytokine (TNF‐α) production. Pretreating mice with carrageenan once a day before injecting LPS increased the levels of IL‐10 by 2.5‐fold and reduced TNF‐α production by 2‐fold compared with control. So, κ/β‐carrageenan alone and in combination with LPS enhanced the cellular activity and mobility of peritoneal macrophages by increasing cell adhesion and migration compared with control. LPS activated cells intensively, sometimes resulting in their destruction by necrosis; carrageenan pretreatment reduced the excessive inflammatory cell activation caused by LPS. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1549–1557, 2017.
Evaluation of small‐diameter vascular grafts reconstructed from decellularized aorta sheets
Authors: Negishi Jun , Hashimoto Yoshihide , Yamashita Akitatsu , Zhang Yongwei , Kimura Tsuyoshi , Kishida Akio , Funamoto Seiichi
Published: January 2017

Following small‐diameter vascular grafting, blood vessels fail to retain excellent antithrombotic function and therefore require application of antithrombogenic drugs. We have previously reported early attachment of endothelial cells to the luminal surface of high hydrostatic pressure (HHP)‐decellularized arteries after transplantation. In addition, the graft retained antithrombotic function by endothelialization and remained open for several weeks. To fabricate tube grafts of optimal size and shape for small‐diameter vascular grafting, we evaluated decellularized porcine aorta sheets as a suitable antithrombogenic material. Porcine aortic sheets were decellularized using detergent‐based or HHP methods. The HHP‐, but not detergent‐based‐, decellularized aortic sheets were verified to be acellular, and the mechanical properties of the native aortic sheet remained intact. To fabricate vascular grafts, the decellularized aortic sheets were rolled into tubes and secured using fibrin glue bonding. After implantation into a rat carotid artery model, the tubular grafts withstood normal blood pressure, mechanical beating, and pulsatile flow. After 3 weeks, the tubular grafts remained patent and recipient cell infiltration and cell attachment were observed on the luminal surface. These results indicate that HHP‐decellularized aortic sheets may be useful as an antithrombogenic material for tubular vascular grafts. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1293–1298, 2017.
In vivo guided vascular regeneration with a non‐porous elastin‐like polypeptide hydrogel tubular scaffold
Authors: Mahara Atsushi , Kiick Kristi L. , Yamaoka Tetsuji
Published: January 2017

Herein, we demonstrate a new approach for small‐caliber vascular reconstruction using a non‐porous elastin‐like polypeptide hydrogel tubular scaffold, based on the concept of guided vascular regeneration (GVR). The scaffolds are composed of elastin‐like polypeptide, (Val‐Pro‐Gly‐Ile‐Gly)n, for compliance matching and antithrombogenicity and an Arg‐Gly‐Asp (RGD) motif for connective tissue regeneration. When the polypeptide was mixed with an aqueous solution of β‐[Tris(hydroxymethyl)phosphino]propionic acid at 37°C, the polypeptide hydrogel was rapidly formed. The elastic modulus of the hydrogel was 4.4 kPa. The hydrogel tubular scaffold was formed in a mold and reinforced with poly(lactic acid) nanofibers. When tubular scaffolds with an inner diameter of 1 mm and length of 5 mm were implanted into rat abdominal aortae, connective tissue grew along the scaffold luminal surface from the flanking native tissues, resulting in new blood vessel tissue with a thickness of 200 μm in 1 month. In contrast, rats implanted with control scaffolds without the RGD motif died. These results indicate that the non‐porous hydrogel tubular scaffold containing the RGD motif effectively induced rapid tissue regeneration and that GVR is a promising strategy for the regeneration of small‐diameter blood vessels. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 105A: 1746–1755, 2017.
Mimicking physiological flow conditions to study alterations of bioactive glass surfaces in vitro
Authors: Höner Miriam , Böke Frederik , Weber Michael , Fischer Horst
Published: January 2017

Bioactive glasses form a strong bond with surrounding tissue and slowly degrade when implanted in vivo, stimulating the host bone to regenerate itself. We investigated the behaviour of microstructured bioactive glass surfaces (13–93) in an SBF reactor, which mimics physiological flow conditions. The structures were developed to potentially influence cell‐biological long term processes such as osteogenic differentiation. It is therefore important that the structures withstand a certain time in SBF or body fluids. The experiments revealed that these structures were preserved up to 30 days. Although macroscopically stable, mass loss under flowing conditions was 2–2.5%, in contrast to <1% under static conditions. Polished samples in flowing medium lost 2.7% up to day 7 and then regained mass, resulting in overall 0.5% mass loss after 30 days. Thicker calcium phosphate rich layers for the samples in flowing medium were detected, demonstrating better bone bonding capacity than predicted conventionally. The hydroxyapatite conversion in the reactor was comparable to published in vivo data. We conclude that surface alterations that occur in vivo can be better mimicked by using the proposed flow bioreactor than by the established SBF method in static medium. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 228–236, 2018.
Evaluation of wrought Zn–Al alloys (1, 3, and 5 wt % Al) through mechanical and in vivo testing for stent applications
Authors: Bowen Patrick K. , Seitz Jan‐Marten , Guillory Roger J. , Braykovich Jacob P. , Zhao Shan , Goldman Jeremy , Drelich Jaroslaw W.
Published: January 2017

Special high grade zinc and wrought zinc‐aluminum (Zn–Al) alloys containing up to 5.5 wt % Al were processed, characterized, and implanted in rats in search of a new family of alloys with possible applications as bioabsorbable endovascular stents. These materials retained roll‐induced texture with an anisotropic distribution of the second‐phase Al precipitates following hot‐rolling, and changes in lattice parameters were observed with respect to Al content. Mechanical properties for the alloys fell roughly in line with strength (190–240 MPa yield strength; 220–300 MPa ultimate tensile strength) and elongation (15–30%) benchmarks, and favorable elastic ranges (0.19–0.27%) were observed. Intergranular corrosion was observed during residence of Zn–Al alloys in the murine aorta, suggesting a different corrosion mechanism than that of pure zinc. This mode of failure needs to be avoided for stent applications because the intergranular corrosion caused cracking and fragmentation of the implants, although the composition of corrosion products was roughly identical between non‐ and Al‐containing materials. In spite of differences in corrosion mechanisms, the cross‐sectional reduction of metals in murine aorta was nearly identical at 30–40% and 40–50% after 4.5 and 6 months, respectively, for pure Zn and Zn–Al alloys. Histopathological analysis and evaluation of arterial tissue compatibility around Zn–Al alloys failed to identify areas of necrosis, though both chronic and acute inflammatory indications were present. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 245–258, 2018.
Chitosan coatings with enhanced biostability in vivo
Authors: Gallyamov Marat O. , Chaschin Ivan S. , Bulat Matvey V. , Bakuleva Natalia P. , Badun Gennadii A. , Chernysheva Maria G. , Kiselyova Olga I. , Khokhlov Alexei R.
Published: January 2017

In this article, we study the stability of chitosan coatings applied on glutaraldehyde‐stabilized bovine pericardium when exposed to biodegradation in vivo in the course of model subcutaneous tests on rats. The coatings were deposited from carbonic acid solutions, that is, H2O saturated with CO2 at high pressure. Histological sections of treated pericardium samples demonstrated that the structure of pericardial connective tissues was not significantly altered by the coating application method. It was revealed that the dynamics of biodegradation depended on the total mass of chitosan applied as well as on the DDA of chitosan used. As long as the amount of chitosan did not exceed a certain threshold limit, no detectable degradation occurred within the time of the tests (12 weeks for the rat model). For higher chitosan amounts, we detected a ∼20% reduction of the mass after the in vivo exposition. The presumed mechanism of such behavior is discussed. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 270–277, 2018.
Development of an electrospun biomimetic polyurea scaffold suitable for vascular grafting
Authors: Madhavan Krishna , Frid Maria G. , Hunter Kendall , Shandas Robin , Stenmark Kurt R. , Park Daewon
Published: January 2017

The optimization of biomechanical and biochemical properties of a vascular graft to render properties relevant to physiological environments is a major challenge today. These critical properties of a vascular graft not only regulate its stability and integrity, but also control invasion of cells for scaffold remodeling permitting its integration with native tissue. In this work, we have synthesized a biomimetic scaffold by electrospinning a blend of a polyurea, poly(serinol hexamethylene urea) (PSHU), and, a polyester, poly‐ε‐caprolactone (PCL). Mechanical properties of the scaffold were varied by varying polymer blending ratio and electrospinning flow rate. Mechanical characterization revealed that scaffolds with lower PSHU content relative to PCL content resulted in elasticity close to native mammalian arteries. We also found that increasing electrospinning flow rates also increased the elasticity of the matrix. Optimization of elasticity generated scaffolds that enabled vascular smooth muscle cells (SMCs) to adhere, grow and maintain a SMC phenotype. The 30/70 scaffold also underwent slower degradation than scaffolds with higher PSHU content, thereby, providing the best option forin vivoremodeling. Further, Gly‐Arg‐Gly‐Asp‐Ser (RGD) covalently conjugated to the polyurea backbone in 30/70 scaffold resulted in significantly increased clotting times. Reducing surface thrombogenicity by the conjugation of RGD is critical to avoiding intimal hyperplasia. Hence, biomechanical and biochemical properties of a vascular graft can be balanced by optimizing synthesis parameters and constituent components. For these reasons, the optimized RGD‐conjugated 30/70 scaffold electrospun at 2.5 or 5 mL/h has great potential as a suitable material for vascular grafting applications. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 278–290, 2018.
Assessment of range‐separated exchange functionals and nonempirical functional tuning for calculating the static second hyperpolarizabilities of streptocyanines
Authors: Wang Chao , Yuan Yizhong , Tian Xiaohui
Published: January 2017

DFT method can severely overestimate the response properties for π‐conjugation systems. The range‐separated exchange and recently developed optimal IP‐tuning process are evaluated on the prediction of static second hyperpolarizabilities of streptocyanines of increasing molecular length. The finite field results have shown that the exact exchange at midium and long distance can relieve only a part of the overshooting but still beyond satisfaction. The exact exchange at short distance has the oppsite effects showing the failure of converntional hGGA. The optimal tuned range‐separated exchange functionals show little improvements performing worse than the default ones. Importantly, the electronic structure–property relationship, bond order alternation‐γ, is not well established with DFT method. © 2017 Wiley Periodicals, Inc.
Reliable and efficient reaction path and transition state finding for surface reactions with the growing string method
Authors: Jafari Mina , Zimmerman Paul M.
Published: January 2017

The computational challenge of fast and reliable transition state and reaction path optimization requires new methodological strategies to maintain low cost, high accuracy, and systematic searching capabilities. The growing string method using internal coordinates has proven to be highly effective for the study of molecular, gas phase reactions, but difficulties in choosing a suitable coordinate system for periodic systems has prevented its use for surface chemistry. New developments are therefore needed, and presented herein, to handle surface reactions which include atoms with large coordination numbers that cannot be treated using standard internal coordinates. The double‐ended and single‐ended growing string methods are implemented using a hybrid coordinate system, then benchmarked for a test set of 43 elementary reactions occurring on surfaces. These results show that the growing string method is at least 45% faster than the widely used climbing image‐nudged elastic band method, which also fails to converge in several of the test cases. Additionally, the surface growing string method has a unique single‐ended search method which can move outward from an initial structure to find the intermediates, transition states, and reaction paths simultaneously. This powerful explorative feature of single ended‐growing string method is demonstrated to uncover, for the first time, the mechanism for atomic layer deposition of TiN on Cu(111) surface. This reaction is found to proceed through multiple hydrogen‐transfer and ligand‐exchange events, while formation of H‐bonds stabilizes intermediates of the reaction. Purging gaseous products out of the reaction environment is the driving force for these reactions. © 2017 Wiley Periodicals, Inc.
Prediction of consensus binding mode geometries for related chemical series of positive allosteric modulators of adenosine and muscarinic acetylcholine receptors
Authors: Sakkal Leon A. , Rajkowski Kyle Z. , Armen Roger S.
Published: January 2017

Following insights from recent crystal structures of the muscarinic acetylcholine receptor, binding modes of Positive Allosteric Modulators (PAMs) were predicted under the assumption that PAMs should bind to the extracellular surface of the active state. A series of well‐characterized PAMs for adenosine (A1R, A2AR, A3R) and muscarinic acetylcholine (M1R, M5R) receptors were modeled using both rigid and flexible receptor CHARMM‐based molecular docking. Studies of adenosine receptors investigated the molecular basis of the probe‐dependence of PAM activity by modeling in complex with specific agonist radioligands. Consensus binding modes map common pharmacophore features of several chemical series to specific binding interactions. These models provide a rationalization of how PAM binding slows agonist radioligand dissociation kinetics. M1R PAMs were predicted to bind in the analogous M2R PAM LY2119620 binding site. The M5R NAM (ML‐375) was predicted to bind in the PAM (ML‐380) binding site with a unique induced‐fit receptor conformation. © 2017 Wiley Periodicals, Inc.
Isotope labelling by reduction of nitriles: Application to the synthesis of isotopologues of tolmetin and celecoxib
Authors: Ellis‐Sawyer Kate , Bragg Ryan A. , Bushby Nick , Elmore Charles S. , Hickey Michael J.
Published: January 2017

The aryl methyl group is found in many drug‐like compounds, but there are limited ways of preparing compounds with an isotope label in this methyl position. The process of cyanation of an aryl halide followed by complete reduction of the nitrile to a methyl group was investigated as a route for preparing stable and radiolabelled isotopologues of drug‐like compounds. Using this methodology, carbon‐13, deuterium, carbon‐14, and tritium labelled isotopologues of the nonsteroidal anti‐inflammatory drug tolmetin were produced, as well as carbon‐13, deuterium, and carbon‐14 labelled isotopologues of another nonsteroidal anti‐inflammatory drug, celecoxib. The radiolabelled compounds were produced at high specific activity and the stable isotope labelled compounds with high incorporation making them suitable for use as internal standards in mass spectrometry assays. This approach provides a common synthetic route to multiple isotopologues of compounds using inexpensive and readily available labelled starting materials.
Relation between brown adipose tissue and measures of obesity and metabolic dysfunction in patients with cardiovascular disease
Authors: Franssens Bas T. , Hoogduin Hans , Leiner Tim , van der Graaf Yolanda , Visseren Frank L.J.
Published: January 2017

Purpose

To evaluate whether brown adipose tissue (BAT) is present in middle‐aged patients with cardiovascular comorbidities and to quantify how BAT presence associates with obesity and metabolic dysfunction.

Materials and Methods

Supraclavicular and subcutaneous adipose tissue fat‐signal‐fraction (FF) was determined with 1.5T water–fat magnetic resonance imaging (MRI) in 50 patients with coronary artery disease, cerebrovascular disease, or peripheral artery disease. The association between BAT presence, as measured by a higher FF difference between supraclavicular and subcutaneous adipose tissue, and obesity and metabolic dysfunction was quantified using multivariable linear regression.

Results

Supraclavicular adipose tissue displays a lower FF of 82.6% (interquartile range [IQR] 78.8–84.3) compared to 90.2% (IQR 87.3–91.9) in subcutaneous white adipose tissue (WAT, P < 0.0001). BAT presence was associated with less obesity and metabolic dysfunction. For example, 1 SD lower waist circumference (11.7 cm), 1 SD lower triglycerides (1.0 mmol/L), and absence of metabolic syndrome and type 2 diabetes were associated with 1.1% (95% confidence interval [CI] 0.1; 2.0), 1.1% (95% CI 0.1; 2.0), 2.1% (95% CI 0.1; 4.1), and 4.1% (95% CI 0.1; 7.1) higher FF difference between supraclavicular adipose tissue and subcutaneous WAT, respectively.

Conclusion

Supraclavicular adipose tissue has BAT characteristics in adult patients with clinical manifest cardiovascular disease and BAT presence is associated with less obesity and a more favorable metabolic profile.

Level of Evidence: 2

Technical Efficacy: Stage 2

J. MAGN. RESON. IMAGING 2017;46:497–504
MR measurement of luminal water in prostate gland: Quantitative correlation between MRI and histology
Authors: Sabouri Shirin , Fazli Ladan , Chang Silvia D. , Savdie Richard , Jones Edward C. , Goldenberg S. Larry , Black Peter C. , Kozlowski Piotr
Published: January 2017

Purpose

To determine the relationship between parameters measured from luminal water imaging (LWI), a new magnetic resonance imaging (MRI) T2 mapping technique, and the corresponding tissue composition in prostate.

Materials and Methods

In all, 17 patients with prostate cancer were examined with a 3D multiecho spin echo sequence at 3T prior to undergoing radical prostatectomy. Maps of seven MR parameters, called N, T2‐short, T2‐long, Ashort, Along, geometric mean T2 time (gmT2), and luminal water fraction (LWF), were generated using nonnegative least squares (NNLS) analysis of the T2 decay curves. MR parametric maps were correlated to digitized whole‐mount histology sections. Percentage area of tissue components, including luminal space, nuclei, and cytoplasm plus stroma, was measured on the histology sections by using color‐based image segmentation. Spearman's rank correlation test was used to evaluate the correlation between MR parameters and the corresponding tissue components, with particular attention paid to the correlation between LWF and percentage area of luminal space.

Results

N, T2‐short, Along, gmT2, and LWF showed significant correlation (P < 0.05) with percentage area of luminal space and stroma plus cytoplasm. T2‐short and gmT2 also showed significant correlation (P < 0.05) with percentage area of nuclei. Overall, the strongest correlation was observed between LWF and luminal space (Spearman's coefficient of rank correlation = 0.75, P < 0.001).

Conclusion

Results of this study show that LWF measured with MRI is strongly correlated with the fractional amount of luminal space in prostatic tissue. This result suggests that LWI can potentially be applied for evaluation of prostatic diseases in which the extent of luminal space differs between normal and abnormal tissues.

Level of Evidence: 1

Technical Efficacy: Stage 1

J. MAGN. RESON. IMAGING 2017;46:861–869