bluuebunny/crossref_metadata_2025_split huggingface dataset:
High Glass Transition of Fluorinated Polyimides Derived from 4‐(3,4‐Difluorophenyl)‐2,6‐bis(4‐aminophenyl)pyridine
Authors: Xu Xu , Chen Beicai , Li Hua , Huang Xiaohua , Wei Chun 
Published: March 2017

AbstractA series of novel fluorinated polyimides (PIs) were prepared from 4‐(3,4‐difluorophenyl)‐2,6‐bis(4‐aminophenyl)pyridine (FPAP) and commercial aromatic dianhydrides via conventional two‐step thermal imidization technique. The structure of the monomer was confirmed by FT‐IR, NMR, and mass spectrometry. All of the obtained PIs were studied with FT‐IR, TGA, DSC, WAXD and contact angles analysis. These results showed that polymer materials presented excellent thermal properties with the glass transition temperature (Tg) in the range of 336—434 °C, as well as T5%, and T10% decomposition temperature ranges of 543—600 °C and 562—622 °C in a nitrogen atmosphere, respectively. Moreover, they presented excellent mechanical properties with tensile strengths of 68—91 MPa, elongation at break of 5.6%—10.2%, and young's modulus of 1.8—2.4 GPa. Furthermore, they showed outstanding hydrophobicity with the contact angle in the range of 90.5°—96.6°, and the results of WAXD indicated all of the polymers presented amorphous structure.
Structure‐Based Design and Synthesis of Harmine Derivatives with Different Selectivity Profiles in Kinase versus Monoamine Oxidase Inhibition
Authors: Bálint Balázs , Wéber Csaba , Cruzalegui Francisco , Burbridge Mike , Kotschy Andras 
Published: March 2017

AbstractDual‐specificity tyrosine‐phosphorylation‐regulated kinase 1A (DYRK1A) is an emerging biological target with implications in diverse therapeutic areas such as neurological disorders (Down syndrome, in particular), metabolism, and oncology. Harmine, a natural product that selectively inhibits DYRK1A amongst kinases, could serve as a tool compound to better understand the biological processes that arise from DYRK1A inhibition. On the other hand, harmine is also a potent inhibitor of monoamine oxidase A (MAO‐A). Using structure‐based design, we synthesized a collection of harmine analogues with tunable selectivity toward these two enzymes. Modifications at the 7‐position typically decreased affinity for DYRK1A, whereas substitution at the 9‐position had a similar effect on MAO‐A inhibition but DYRK1A inhibition was maintained. The resulting collection of compounds can help to understand the biological role of DYRK1A and also to assess the interference in the biological effect originating in MAO‐A inhibition.
Identifying Protein Allosteric Transitions for Drug Discovery with 1D NMR
Authors: Krimm Isabelle 
Published: March 2017

AbstractAllosteric drugs present many advantages over orthosteric drugs and are therefore an attractive approach in drug discovery, despite being highly challenging. First, the binding of ligands in protein allosteric pockets do not ensure an allosteric effect, and second, allosteric ligands can possess diverse modes of pharmacology even within a compound family. Herein we report a new method to: 1) detect allosteric communication between protein binding sites, and 2) compare the effect of allosteric ligands on the allosteric transitions of the protein target. The method, illustrated with glycogen phosphorylase, consists of comparing 1D saturation transfer difference (STD) NMR spectra of a molecular spy (here fragments) in the absence and presence of allosteric ligands. The modification of the STD NMR spectrum of the fragment indicates whether the protein dynamics/conformations have been changed in the presence of the allosteric modulator, thereby highlighting allosteric coupling between the binding pocket of the reference compound (in this case the fragment) and the allosteric pocket.
Synthesis and Cytotoxicity Evaluation of C4‐ and C5‐Modified Analogues of the α,β‐Unsaturated Lactone of Pironetin
Authors: Huang David S. , Wong Henry L. , Georg Gunda I. 
Published: March 2017

AbstractPironetin is a natural product with potent antiproliferative activity that forms a covalent adduct with α‐tubulin via conjugate addition into the natural product's α,β‐unsaturated lactone. Although pironetin's α,β‐unsaturated lactone is involved in its binding to tubulin, the structure–activity relationship at different positions of the lactone have not been thoroughly evaluated. For a systematic evaluation of the structure–activity relationships at the C4 and C5 positions of the α,β‐unsaturated lactone of pironetin, twelve analogues of the natural product were prepared by total synthesis. Modifying the stereochemistry at the C4 and/or C5 positions of the α,β‐unsaturated lactone of pironetin resulted in loss of antiproliferative activity in OVCAR5 ovarian cancer cells. While changing the C4 ethyl substituent with groups such as methyl, propyl, cyclopropyl, and isobutyl were tolerated, groups with larger steric properties such as an isopropyl and benzyl groups were not.
1,3,5‐Trisubstituted Pyrazoles as Potent Negative Allosteric Modulators of the mGlu2/3 Receptors
Authors: Van Gool Michiel , Alonso De Diego Sergio A. , Delgado Oscar , Trabanco Andrés A. , Jourdan Fabrice , Macdonald Gregor J. , Somers Marijke , Ver Donck Luc 
Published: March 2017

AbstractThe metabotropic glutamate subtype 2 (mGlu2) receptor is a presynaptic membrane receptor distributed widely in brain that provides feedback inhibitory control of glutamate release. Inhibition of the mGlu2 receptor function with a negative allosteric modulator (NAM) enhances activity‐dependent glutamate release, which may be of therapeutic benefit for the treatment of neurological and psychiatric disorders. An attractive pyrazole hit was identified after a high‐throughput screening (HTS) campaign. The evolution of this hit is described by structure–activity relationship (SAR) studies on specific parts of the molecule. From near micromolar potency we could obtain compounds with single‐digit nanomolar activity in the mGlu2 NAM GTPγS assay. In addition to SAR on in vitro potency, a more detailed overview is given with a specific set of compounds on the excellent agreement between in vitro potency, free brain concentration, and ex vivo mGlu2 receptor occupancy. Finally, to obtain improved drug‐like compounds, plans for future research are suggested toward increasing free brain concentration while maintaining high in vitro potency.
Cytological evaluation by fine needle aspiration biopsy of incidental focal increased fluorodeoxyglucose uptake in thyroid on positron emission tomography scan
Authors: Li Yanchun , Cui Min , Azar Nami , Nakamoto Dean , Michael Claire W. 
Published: March 2017

BackgroundWith the increased use of whole body fluorodeoxyglucose positron emission tomography (PET) scan for staging/restaging or primary diagnosis of neoplasia, thyroid incidentalomas have become more common. The limited reports of PET‐positive thyroid incidentalomas showed incidence of malignancy ranging from 14 to 66%, and there is discrepancy in terms of the diagnostic significance of the standard uptake value (SUV) value.MethodsThis is a retrospective study of 20 PET incidentalomas which had cytological evaluation from October 2009 to February 2015 at a tertiary care university medical center, M:F = 8:12.ResultsOf the 20 cases, 14 (70%) had a cytological diagnosis of atypia or suspicious for neoplasia. Eleven of those (55%) underwent surgical resection with final diagnosis of PTC in 8 cases, follicular carcinoma in one case (5%), follicular adenoma in one case (5%), and Hurthle cell adenoma in one case (5%). There was good correlation between cytological and histological diagnosis. For two cases with cytological diagnosis of suspicious for follicular neoplasm, no further histological diagnosis was obtained. One patient had direct cytological diagnosis of PTC also did not undergo surgical resection/diagnosis due to the advanced primary pancreatic adenocarcinoma. The remaining 6 (30%) cases had a cytological diagnosis of benign follicular nodule. Furthermore, no significant difference between malignant SUV and benign SUV was observed.ConclusionsMalignancy was identified in 50% of the PET‐positive incidentalomas in our series. PTC constitutes the major malignant diagnosis. No diagnostic value of SUV was observed to differentiate malignant from benign lesions. Diagn. Cytopathol. 2017;45:501–506. © 2017 Wiley Periodicals, Inc.
Synthesis and application of benzenesulfonic acid doped polyaniline nanorods for decolorization of simulated remazol effluent
Authors: Venkatachalam Janaki , Seralathan Kamala‐Kannan 
Published: March 2017

Benzenesulfonic acid‐doped polyaniline nanorods were synthesized by oxidative polymerization of aniline and were subsequently used for the decolorization of simulated reactive dye bath effluent. Transmission electron micrograph showed that the size of the nanorods varied from 60 to 90 nm. Fourier transform infrared pattern of nanorods indicate that sulfonic acid was successfully doped on polyaniline nanorods. Under optimized conditions, sulfonic acid doped polyaniline nanorods decolorized 78% of simulated reactive dye bath effluent. The modified Freundlich model and modified pseudo‐first‐order model showed satisfactory fit for dye decolorization. The crystalline nature of the nanorods was modified after adsorption of dyes. The results of the study indicate that benzenesulfonic acid doped polyaniline could be used for the treatment of textile wastewaters. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1383–1389, 2017
Age differences in the motor control of speech: An fMRI study of healthy aging
Authors: Tremblay Pascale , Sato Marc , Deschamps Isabelle 
Published: March 2017

AbstractHealthy aging is associated with a decline in cognitive, executive, and motor processes that are concomitant with changes in brain activation patterns, particularly at high complexity levels. While speech production relies on all these processes, and is known to decline with age, the mechanisms that underlie these changes remain poorly understood, despite the importance of communication on everyday life. In this cross‐sectional group study, we investigated age differences in the neuromotor control of speech production by combining behavioral and functional magnetic resonance imaging (fMRI) data. Twenty‐seven healthy adults underwent fMRI while performing a speech production task consisting in the articulation of nonwords of different sequential and motor complexity. Results demonstrate strong age differences in movement time (MT), with longer and more variable MT in older adults. The fMRI results revealed extensive age differences in the relationship between BOLD signal and MT, within and outside the sensorimotor system. Moreover, age differences were also found in relation to sequential complexity within the motor and attentional systems, reflecting both compensatory and de‐differentiation mechanisms. At very high complexity level (high motor complexity and high sequence complexity), age differences were found in both MT data and BOLD response, which increased in several sensorimotor and executive control areas. Together, these results suggest that aging of motor and executive control mechanisms may contribute to age differences in speech production. These findings highlight the importance of studying functionally relevant behavior such as speech to understand the mechanisms of human brain aging. Hum Brain Mapp 38:2751–2771, 2017. © 2017 Wiley Periodicals, Inc.
Impact of resident training on operative time and safety in hemithyroidectomy
Authors: Folsom Craig , Serbousek Kimberly , Lydiatt William , Rieke Katherine , Sayles Harlan , Smith Russell , Panwar Aru 
Published: March 2017

ABSTRACTBackgroundThe purpose of this study was to present our assessment of the impact of resident participation on operative duration and outcomes after hemithyroidectomy, which may identify opportunities for optimization of educational programs, reduction in cost of healthcare delivery, and maximizing patient safety, while continuing to train a competent physician workforce for the future.MethodsThe American College of Surgeons' National Surgical Quality Improvement Program (ACS NSQIP) dataset from 2006 to 2012 identified 13,151 adult patients who underwent hemithyroidectomy. Differences in operative duration, postoperative complications, reoperation, and readmission rates were assessed based on stratification by resident participation in surgery.ResultsCompared with operations performed by attending surgeons alone, resident participation with attending supervision prolonged the operative duration by 10.5% (82.5 minutes vs 91.2 minutes; p < .0001). The incidence of readmission and wound complications was higher for patients who underwent surgery with resident participation.ConclusionResident participation in hemithyroidectomy may be associated with increased operative duration, higher incidence of wound complications, and readmission. © 2017 Wiley Periodicals, Inc. Head Neck 39: 1212–1217, 2017
Total and Visceral Adiposity Are Associated With Prevalent Vertebral Fracture in Women but Not Men at Age 62 Years: The Newcastle Thousand Families Study
Authors: Hind Karen , Pearce Mark , Birrell Fraser 
Published: March 2017

ABSTRACT

Low body weight is an established risk factor for osteoporosis and fracture, but the skeletal risks of higher adiposity are unclear and appear sex-specific and site-dependent. The aim of this study was to investigate associations of total fat mass (TFM), visceral adipose tissue (VAT), and C-reactive protein (CRP) with bone mineral density (BMD) and prevalent vertebral fracture (VF) in men and women aged 62 years. A total of 352 men and women aged 62.5 ± 0.5 years from the Newcastle Thousand Families Study cohort received dual-energy X-ray absorptiometry (DXA) evaluations of femoral neck and lumbar spine BMD, of the lateral spine for vertebral fracture assessment, and of the whole body for TFM and VAT (GE Lunar CoreScan, Madison, WI, USA). Plasma CRP, FRAX scores, falls in the last 12 months, and occupation at age 50 years were also included in the analysis. Vertebral fractures were less prevalent in women than in men (odds ratio [OR] = 0.33, p &lt; 0.001) and BMD or FRAX scores did not differ between participants with and without VF. Women with VF were heavier and had higher TFM, VAT, and CRP than women without (p &lt; 0.001). In women, greater (+1 SD) TFM and VAT increased the odds of any grade VF (TFM: OR = 1.06, p = 0.001; VAT: OR = 2.50, p = 0.002), and greater VAT mass increased the odds of prevalent mild VF (OR = 2.60, p = 0.002). In contrast, there were no associations in men. In both sexes, after controlling for body weight, neither VAT nor CRP were associated with BMD. In conclusion, irrespective of BMD, total and visceral adiposity were associated with prevalent VF in women but not in men. High fat mass, particularly if visceral, should be considered when assessing VF risk in women. Risk factors for VF in men require further investigation, particularly given their high prevalence. © 2017 American Society for Bone and Mineral Research.
Metastatic Breast Cancer Cells Enter Into Dormant State and Express Cancer Stem Cells Phenotype Under Chronic Hypoxia
Authors: Carcereri de Prati Alessandra , Butturini Elena , Rigo Antonella , Oppici Elisa , Rossin Michele , Boriero Diana , Mariotto Sofia 
Published: March 2017

ABSTRACTTumor dormancy is a poorly understood stage in cancer progression characterized by mitotic cycle arrest in G0/G1 phase and low metabolism. The cells survive in a quiescent state and wait for appropriate environmental conditions to begin proliferation again giving rise to metastasis. Despite their key role in cancer development and metastasis, the knowledge about their biology and origin is still very limited due to the poorness of established in vitro models that faithfully recapitulated tumor dormancy. Using at least three cycles of 1% O2 hypoxia and reoxygenation, we establish and characterize the hypoxia‐resistant human breast cancer cell line chMDA‐MB‐231 that can stably survive under 1% O2 condition by entering into dormant state characterized by arrest in G0/G1 phase and low metabolism. This dormant state is reversible since once replaced in normoxia the cells recover the proliferation rate in 2 weeks. We show that chronic hypoxia induces autophagy that may be the survival mechanism of chMDA‐MB‐231 cells. Furthermore, the data in this work demonstrate that cycling hypoxic/reoxygenation stress selects MDA‐MB‐231 population that presents the cancer stem‐like phenotype characterized by CD24−/CD44+/ESA+ expression and spheroid forming capacity. We believe that our study presents a promising approach to select dormant breast cancer cells with stem‐like phenotype using the hypoxia/reoxygenation regimen that may represent an area with profound implications for therapeutic developments in oncology. J. Cell. Biochem. 118: 3237–3248, 2017. © 2017 Wiley Periodicals, Inc.
The fatty acid profile of fat depots from Santa Inês sheep fed spineless cactus (Opuntia ficus‐indica Mill.)
Authors: Costa Roberto G , Almeida Michelly DA , Cruz George Rodrigo B , Beltrão Filho Edvaldo M , Ribeiro Neila L , Madruga Marta S , Queiroga Rita de Cássia RE 
Published: March 2017

AbstractBACKGROUNDFat is the tissue that varies most in animals from both a quantitative and distribution perspective. It plays a fundamental biological role as energy storage during food scarcity. Renal, pelvic and internal fat are deposited first. These fats are used to identify fatty acid profiles that may be considered beneficial or unhealthy. The aim of this study is to evaluate the fatty acid profile of fat depots in Santa Inês sheep finished in confinement with spineless cactus in their diets.RESULTSThe treatments included increasing levels of spineless cactus (Opuntia fícus‐indica Mill.): T1 = 0%, T2 = 30%, T3 = 50%, and T4 = 70%. The diets significantly affected the adipose depots. The orthogonal contrast between the diet with no cactus (control) and the other diets indicates that the quantity of saturated fatty acids decreased and that the levels of mono‐unsaturated and polyunsaturated fatty acids increased in animals fed spineless cactus.CONCLUSIONThe use of spineless cactus in the diets of Santa Inês sheep affects the lipid profile of their fat depots, reducing the quantity of saturated fatty acids and increasing the quantity of mono‐unsaturated and polyunsaturated fatty acids. The fatty acid profile of the fat depots indicates that these fats can be used to formulate meat products and add economic and nutritional value to such products, which increases sheep farmers' incomes. © 2017 Society of Chemical Industry
Coupled changes between the H‐Print biomarker and δ15N indicates a variable sea ice carbon contribution to the diet of Cumberland Sound beluga whales
Authors: Brown T. A. , Chrystal E. , Ferguson S. H. , Yurkowski D. J. , Watt C. , Hussey N. E. , Kelley T. C. , Belt S. T. 
Published: March 2017

AbstractSub‐Arctic habitats are being exposed to increasingly long periods of open water as sea ice continues to decline in thickness and extent. Some hypothesize that this will result in a reduction, and maybe total loss of sea ice derived (sympagic) carbon supply; however, the impact of such change on ecosystems requires further investigation. Here, we used the H‐Print biomarker approach that utilizes well‐defined indicators of both sympagic and phytoplanktic carbon, in combination with stable isotopes (δ15N), to study the effect of reducing sympagic carbon availability on beluga whales (Delphinapterus leucas) in the sub‐Arctic ecosystem of Cumberland Sound. Our data show that decreasing δ15N in belugas was negatively correlated with pelagic carbon (H‐Print) within their diet. We also identified a statistically significant (R2 = 0.82; p ≤ 0.01) change point in the proportion of sympagic/pelagic carbon within beluga around the year 2000, signified by consistently reducing δ15N, coupled with increasing pelagic carbon composition. This observed shift from sympagic to pelagic contribution to diet is likely to remain a feature of the Cumberland Sound ecosystem during the projected reduction of sea ice.
Fast shading correction for cone beam CT in radiation therapy via sparse sampling on planning CT
Authors: Shi Linxi , Tsui Tiffany , Wei Jikun , Zhu Lei 
Published: March 2017

PurposeThe image quality of cone beam computed tomography (CBCT) is limited by severe shading artifacts, hindering its quantitative applications in radiation therapy. In this work, we propose an image‐domain shading correction method using planning CT (pCT) as prior information which is highly adaptive to clinical environment.MethodWe propose to perform shading correction via sparse sampling on pCT. The method starts with a coarse mapping between the first‐pass CBCT images obtained from the Varian TrueBeam system and the pCT. The scatter correction method embedded in the Varian commercial software removes some image errors but the CBCT images still contain severe shading artifacts. The difference images between the mapped pCT and the CBCT are considered as shading errors, but only sparse shading samples are selected for correction using empirical constraints to avoid carrying over false information from pCT. A Fourier‐Transform‐based technique, referred to as local filtration, is proposed to efficiently process the sparse data for effective shading correction. The performance of the proposed method is evaluated on one anthropomorphic pelvis phantom and 17 patients, who were scheduled for radiation therapy. (The codes of the proposed method and sample data can be downloaded from https://sites.google.com/view/linxicbct)ResultsThe proposed shading correction substantially improves the CBCT image quality on both the phantom and the patients to a level close to that of the pCT images. On the phantom, the spatial nonuniformity (SNU) difference between CBCT and pCT is reduced from 74 to 1 HU. The root of mean square difference of SNU between CBCT and pCT is reduced from 83 to 10 HU on the pelvis patients, and from 101 to 12 HU on the thorax patients. The robustness of the proposed shading correction is fully investigated with simulated registration errors between CBCT and pCT on the phantom and mis‐registration on patients. The sparse sampling scheme of our method successfully avoids false structures in the corrected CBCT even when the maximum registration error is as high as 8 mm.ConclusionWe develop an effective shading correction algorithm for CBCT readily implementable on clinical data as a software plug‐in without modifications of current imaging hardware and protocol. The algorithm is directly applied on the output images from a commercial CBCT scanner with high computational efficiency and negligible memory burden.
Coupling of CFD Simulations and Population Balance Modeling to Predict Brownian Coagulation in an Emulsion Polymerization Reactor
Authors: Aryafar Solmaz , Sheibat‐Othman Nida , McKenna Timothy F. L. 
Published: March 2017

AbstractIn this study a framework consisting of a computational fluid dynamics simulation coupled to a population balance model for the modeling of emulsion polymerizations is proposed. The combined approach is used to understand the impact of changing length and time scales, as well as mixing conditions on the particle size distribution (PSD) of a polymer latex under different conditions. It is shown that the effect of agitation rate can have a profound impact on the distribution of ionic species in the reactor, and thus on the evolution of the PSD.
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