bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Bisamide Derivative of [Mn(1,4‐DO2A)] – Solution Thermodynamic, Kinetic, and NMR Relaxometric Studies
Authors: Forgács Attila , Tei Lorenzo , Baranyai Zsolt , Tóth Imre , Zékány László , Botta Mauro 
Published: February 2016

AbstractA new 1,4‐DO2A‐bisamide [1,4‐DO2AM; 1,4‐DO2A = 2,2′‐(1,4,7,10‐tetraazacyclododecane‐1,4‐diyl)diacetic acid] ligand was synthesized, and its MnII complex was prepared and investigated in detail by solution thermodynamic, kinetic, and 1H and 17O NMR relaxometric measurements. Although the stability constant of [Mn(1,4‐DO2AM)]2+ (log KMnL = 12.64) is 2.5 log K units lower than that of [Mn(1,4‐DO2A)], its kinetic inertness, investigated through its transmetallation reactions with Zn2+ ions, is much higher. In particular, the dissociation half‐life (t1/2) of [Mn(1,4‐DO2AM)]2+ is ten times higher than that of [Mn(1,4‐DO2A)] (t1/2 = 556 vs. 49 h, pH 7.4). The longer rotational correlation time (τR = 53 ps) for [Mn(1,4‐DO2AM)]2+ is mainly responsible for the slightly higher (+20 %) relaxivity (r1 = 2.5 mM–1 s–1, 20 MHz, 25 °C) with respect to that of [Mn(1,4‐DO2A)]. Notably, the water exchange rate of the coordinated water molecule is one order of magnitude slower than that of [Mn(1,4‐DO2A)] (298kex = 115 ± 6 × 106 s–1). Finally, the dynamic properties of [Zn(1,4‐DO2AM)] were investigated by NMR spectroscopy, and the decoordination and arm‐rotation processes of the acetamide pendant arms were followed.
Observations on the Influence of Precursor Conformations on Macrocyclization Reactions
Authors: Hammershøj Peter , Beldring Klavs , Nielsen Anders R. , Fristrup Peter , Clausen Mads H. 
Published: February 2016

AbstractMacrocycles hold great promise in drug discovery as an underutilized class of lead compounds. The low abundance of these molecules can, in part, be explained by the inherent difficulties in the synthesis of macrocycles and the lack of general methods for their rapid assembly. We have undertaken a research program aimed at developing methods for facile synthesis of macrocycles from simple precursors. The synthesis of two new cyclization precursors is described and the results of their reaction with thionyl chloride are presented and discussed. Whereas one acyclic diol smoothly underwent macrocyclization to afford a mixture of diastereomeric sulfites, subjection of the other precursor to identical reaction conditions resulted in the isolation of the linear dichloride. We hypothesize that there is a difference in the ability of the two molecules to adopt a conformation that is germane to macrocyclization, a proposition that is supported by conformational analyses using molecular mechanics.
Computational Design, Synthesis and Application of a New Selective Molecularly Imprinted Polymer for Electrochemical Detection
Authors: Abdel Ghani Nour T. , Mohamed El Nashar Rasha , Abdel‐Haleem Fatehy M. , Madbouly Adel 
Published: February 2016

AbstractA computational approach was developed to find a suitable functional monomer to design a new molecularly imprinted polymer (MIP), based on which methacyrlic acid (MAA) was selected as a functional monomer to synthesize the molecular imprinted and non‐imprinted polymers. All calculations were carried out using Gaussian 03 software based on the application of Hartree−Fock (HF) method with 6‐31G (d) basis set. The performance of the MIPs prepared with different ratios of MAA was then evaluated using equilibrium rebinding assays. The MIP with the highest binding capacity was chosen as recognition material for the fabrication of new PVC sensors and their responses were compared with each other and with previously reported modifiers in literature. The addition of the ionic surfactant (TFPB) was found to have a synergistic effect on the response mechanism of the electrodes. The results of the MIP modified sensors show that they provide an improved electrode slope, wider pH range and a highly extended life time reaching 7 months compared to 2–4 weeks in case of traditional ion‐exchangers reported in literature, besides, being successfully applied for measurements in biological samples.
Bioaccessibility tests accurately estimate bioavailability of lead to quail
Authors: Beyer W. Nelson , Basta Nicholas T. , Chaney Rufus L. , Henry Paula F. P. , Mosby David E. , Rattner Barnett A. , Scheckel Kirk G. , Sprague Daniel T. , Weber John S. 
Published: February 2016

Abstract

Hazards of soil-borne lead (Pb) to wild birds may be more accurately quantified if the bioavailability of that Pb is known. To better understand the bioavailability of Pb to birds, the authors measured blood Pb concentrations in Japanese quail (Coturnix japonica) fed diets containing Pb-contaminated soils. Relative bioavailabilities were expressed by comparison with blood Pb concentrations in quail fed a Pb acetate reference diet. Diets containing soil from 5 Pb-contaminated Superfund sites had relative bioavailabilities from 33% to 63%, with a mean of approximately 50%. Treatment of 2 of the soils with phosphorus (P) significantly reduced the bioavailability of Pb. Bioaccessibility of Pb in the test soils was then measured in 6 in vitro tests and regressed on bioavailability: the relative bioavailability leaching procedure at pH 1.5, the same test conducted at pH 2.5, the Ohio State University in vitro gastrointestinal method, the urban soil bioaccessible lead test, the modified physiologically based extraction test, and the waterfowl physiologically based extraction test. All regressions had positive slopes. Based on criteria of slope and coefficient of determination, the relative bioavailability leaching procedure at pH 2.5 and Ohio State University in vitro gastrointestinal tests performed very well. Speciation by X-ray absorption spectroscopy demonstrated that, on average, most of the Pb in the sampled soils was sorbed to minerals (30%), bound to organic matter (24%), or present as Pb sulfate (18%). Additional Pb was associated with P (chloropyromorphite, hydroxypyromorphite, and tertiary Pb phosphate) and with Pb carbonates, leadhillite (a lead sulfate carbonate hydroxide), and Pb sulfide. The formation of chloropyromorphite reduced the bioavailability of Pb, and the amendment of Pb-contaminated soils with P may be a thermodynamically favored means to sequester Pb. Environ Toxicol Chem 2016;35:2311–2319. Published 2016 Wiley Periodicals Inc. on behalf of SETAC. This article is a US Government work and, as such, is in the public domain in the United States of America.
Development of Helisoma trivolvis pond snails as biological samplers for biomonitoring of current-use pesticides
Authors: Morrison Shane A. , Belden Jason B. 
Published: February 2016

Abstract

Nontarget aquatic organisms residing in wetlands are commonly exposed to current-use pesticides through spray drift and runoff. However, it is frequently challenging to measure exposure because of rapid dissipation of pesticides from water and reduced bioavailability. The authors' hypothesis is that freshwater snails can serve as bioindicators of pesticide exposure based on their capacity to passively accumulate tissue residues. Helisoma trivolvis snails were evaluated as biomonitors of pesticide exposure using a fungicide formulation that contains pyraclostrobin and metconazole and is frequently applied to crops surrounding depressional wetlands. Exposure–response studies indicate that H. trivolvis are tolerant of pyraclostrobin and metconazole at concentrations &gt;10 times those lethal to many aquatic species, with a median lethal concentration based on pyraclostrobin of 441 μg/L (95% confidence interval of 359–555 μg/L). Bioconcentration factors ranged from 137 mL/g to 211 mL/g and from 39 mL/g to 59 mL/g for pyraclostrobin and metconazole, respectively. Elimination studies suggested one-compartmental elimination and snail tissue half-lives (t50) of approximately 15 h and 5 h for pyraclostrobin and metconazole, respectively. Modeling derived toxicokinetic parameters in the context of an environmentally relevant pulsed exposure suggests that residues can be measured in snails long after water concentrations fall below detection limits. With high fungicide tolerance, rapid accumulation, and slow elimination, H. trivolvis may be viable for biomonitoring of pyraclostrobin and should be investigated for other pesticides. Environ Toxicol Chem 2016;35:2320–2329. © 2016 SETAC
Clinicopathological correlates of depression in early Alzheimer's disease in the NACC
Authors: McCutcheon Sarah T. , Han Dingfen , Troncoso Juan , Koliatsos Vassilis E. , Albert Marilyn , Lyketsos Constantine G. , Leoutsakos Jeannie‐Marie S. 
Published: February 2016

ObjectiveDepression may be a prodrome to Alzheimer's disease (AD). We assessed whether AD neuropathology is associated with depression in mild cognitive impairment (MCI) and mild dementia (dAD).MethodsAll clinical and neuropathological data for this study came from the National Alzheimer's Coordinating Center (NACC). Healthy control (HC, n = 120), MCI (n = 77), and mild dAD (n = 93) patients who underwent brain autopsy were included. In regression models with Geriatric Depression Scale (GDS) as the outcome, neuritic plaque (NP) score or Braak Stages of neurofibrillary (NF) pathology were covariates.ResultsGDS was not associated with cognitive status, NP score, Braak Stages, or their interaction. In both models, a history of TIAs, depression within the last 2 years, current benzodiazepine use, and greater severity of neuropsychiatric symptoms were associated with greater depression. In the Braak Stages model, less education was another significant predictor.ConclusionsDepression in early AD appears to be independent of NP and NF pathology. Studies are needed to investigate other mechanisms that may be responsible for depression in MCI and dAD.
The relationship between age and neurocognitive and daily functioning in adults with hoarding disorder
Authors: Dozier Mary E. , Wetherell Julie L. , Twamley Elizabeth W. , Schiehser Dawn M. , Ayers Catherine R. 
Published: February 2016

ObjectiveGiven the increase in hoarding symptoms with age, there is a pressing need for understanding the clinical features as they relate to potential interventions for older adults with hoarding disorder (HD). The aim of the current investigation was to explore age‐related differences in the level of functional and cognitive impairment in individuals with HD.MethodsThe current study utilized the baseline assessments of 122 adults with HD. Age‐related differences in the raw scores of psychiatric, cognitive, and daily functioning were analyzed using a series of multiple regression models controlling for the possible age‐related differences in premorbid IQ.ResultsOur results suggested that older adults with HD may experience increased levels of impairment in skills related to executive functioning and everyday functioning when compared with younger adults with HD.ConclusionsGiven these difficulties with neurocognitive functioning, older HD patients may require interventions that focus more on behavioral and functional skills, rather than focusing on changing thought processes. Copyright © 2016 John Wiley & Sons, Ltd.
Testosterone affects language areas of the adult human brain
Authors: Hahn Andreas , Kranz Georg S. , Sladky Ronald , Kaufmann Ulrike , Ganger Sebastian , Hummer Allan , Seiger Rene , Spies Marie , Vanicek Thomas , Winkler Dietmar , Kasper Siegfried , Windischberger Christian , Swaab Dick F. , Lanzenberger Rupert 
Published: February 2016

AbstractAlthough the sex steroid hormone testosterone is integrally involved in the development of language processing, ethical considerations mostly limit investigations to single hormone administrations. To circumvent this issue we assessed the influence of continuous high‐dose hormone application in adult female‐to‐male transsexuals. Subjects underwent magnetic resonance imaging before and after 4 weeks of testosterone treatment, with each scan including structural, diffusion weighted and functional imaging. Voxel‐based morphometry analysis showed decreased gray matter volume with increasing levels of bioavailable testosterone exclusively in Broca's and Wernicke's areas. Particularly, this may link known sex differences in language performance to the influence of testosterone on relevant brain regions. Using probabilistic tractography, we further observed that longitudinal changes in testosterone negatively predicted changes in mean diffusivity of the corresponding structural connection passing through the extreme capsule. Considering a related increase in myelin staining in rodents, this potentially reflects a strengthening of the fiber tract particularly involved in language comprehension. Finally, functional images at resting‐state were evaluated, showing increased functional connectivity between the two brain regions with increasing testosterone levels. These findings suggest testosterone‐dependent neuroplastic adaptations in adulthood within language‐specific brain regions and connections. Importantly, deteriorations in gray matter volume seem to be compensated by enhancement of corresponding structural and functional connectivity. Hum Brain Mapp 37:1738–1748, 2016. © 2016 Wiley Periodicals, Inc.
Evolution of surgical techniques for mandibular reconstruction using free fibula flaps: The next generation
Authors: Monaco Casian , Stranix John T. , Avraham Tomer , Brecht Lawrence , Saadeh Pierre B. , Hirsch David , Levine Jamie P. 
Published: February 2016

AbstractBackgroundVirtual surgical planning (VSP) has contributed to a number of technical innovations in mandible reconstruction. We report on these innovations and the overall evolution of mandible reconstruction using free fibula flaps at our institution.MethodsWe performed a retrospective chart review of all patients who underwent virtually planned free fibula flap reconstruction of the mandible. Comparisons were made between cohorts based on distinct eras related to the virtual planning approach.ResultsSeventy‐six patients underwent a total of 78 VSP‐assisted mandible reconstructions with free fibula flaps. Significant differences were noted among the groups with regard to mean number of segments, percentage of flaps that had at least 3 segments, percentage of flaps that had double‐barrel components, and innovations per flap.ConclusionVSP‐assisted mandible reconstruction has contributed to more complex surgeries at our institution. The technology ensures functional restoration, permitting an optimized aesthetic reconstruction that has not increased operative times or complications. © 2016 Wiley Periodicals, Inc. Head Neck 38: E2066–E2073, 2016
Genetic association analysis of N‐methyl‐d‐aspartate receptor subunit gene GRIN2B and clinical response to clozapine
Authors: Taylor Danielle L. , Tiwari Arun K. , Lieberman Jeffrey A. , Potkin Steven G. , Meltzer Herbert Y. , Knight Jo , Remington Gary , Müller Daniel J. , Kennedy James L. 
Published: February 2016

ObjectiveApproximately 30% of patients with schizophrenia fail to respond to antipsychotic therapy and are classified as having treatment‐resistant schizophrenia. Clozapine is the most efficacious drug for treatment‐resistant schizophrenia and may deliver superior therapeutic effects partly by modulating glutamate neurotransmission. Response to clozapine is highly variable and may depend on genetic factors as indicated by twin studies. We investigated eight polymorphisms in the N‐methyl‐d‐aspartate glutamate receptor subunit gene GRIN2B with response to clozapine.MethodsGRIN2B variants were genotyped using standard TaqMan procedures in 175 European patients with schizophrenia deemed resistant or intolerant to treatment. Response was assessed using change in Brief Psychiatric Rating Scale scores following six months of clozapine therapy. Categorical and continuous response was assessed using chi‐squared test and analysis of covariance, respectively.ResultsNo associations were observed between the variants and response to clozapine. A‐allele carriers of rs1072388 responded marginally better to clozapine therapy than GG‐homozygotes; however, the difference was not statistically significant (p = 0.067, uncorrected).ConclusionsOur findings do not support a role for these GRIN2B variants in altering response to clozapine in our sample. Investigation of additional glutamate variants in clozapine response is warranted. Copyright © 2016 John Wiley & Sons, Ltd.
Skeletal muscle satellite cells are located at a closer proximity to capillaries in healthy young compared with older men
Authors: Nederveen Joshua P , Joanisse Sophie , Snijders Tim , Ivankovic Victoria , Baker Steven K. , Phillips Stuart M. , Parise Gianni 
Published: February 2016

AbstractBackgroundSkeletal muscle satellite cells (SC) are instrumental in maintenance of muscle fibres, the adaptive responses to exercise, and there is an age‐related decline in SC. A spatial relationship exists between SC and muscle fibre capillaries. In the present study, we aimed to investigate whether chronologic age has an impact on the spatial relationship between SC and muscle fibre capillaries. Secondly, we determined whether this spatial relationship changes in response to a single session of resistance exercise.MethodsMuscle biopsies were obtained from the vastus lateralis of previously untrained young men (YM, 24 ± 3 years; n = 23) and older men (OM, 67 ± 4 years; n = 22) at rest. A subset of YM (n = 9) performed a single bout of resistance exercise, where additional muscle biopsies taken at 24 and 72 h post‐exercise recovery. Skeletal muscle fibre capillarization, SC content, and activation status were assessed using immunofluorescent microscopy of muscle cross sections.ResultsType II muscle fibre SC and capillary content was significantly lower in the YM compared with OM (P < 0.05). Furthermore, type II muscle fibre SC were located at a greater distance from the nearest capillary in OM compared with YM (21.6 ± 1.3 vs. 17.0 ± 0.8 µm, respectively; P < 0.05). In response to a single bout of exercise, we observed a significant increase in SC number and activation status (P < 0.05). In addition, activated vs. quiescent SC were situated closer (P < 0.05) to capillaries.ConclusionsWe demonstrate that there is a greater distance between capillaries and type II fibre‐associated SC in OM as compared with YM. Furthermore, quiescent SC are located significantly further away from capillaries than active SC after single bout of exercise. Our data have implications for how muscle adapts to exercise and how aging may affect such adaptations.
Impact of transcatheter aortic valve implantation on left atrial appendage flow velocities
Authors: Ando Tomo , Holmes Anthony A. , Slovut David P. , Taub Cynthia C. 
Published: February 2016

ABSTRACTPurposeLeft atrial appendage (LAA) flow velocity has not been extensively studied in patients with severe aortic stenosis (AS) undergoing transcatheter aortic valve implantation (TAVI). The aim of this study was to assess the impact of TAVI on LAA flow velocity.MethodsMedical records of consecutive TAVI recipients were reviewed retrospectively. Patients with persistent atrial fibrillation were excluded. LAA velocities were measured before and after TAVI by transesophageal echocardiography.ResultsSixty‐one patients were included. Mean LAA emptying (EV) and filling (FV) flow velocity before TAVI were 33 ± 16 cm/s and 31 ± 14 cm/s, respectively. They increased to 37 ± 20 (p = 0.0036) and 33 ± 13 cm/s (p = 0.047) after TAVI in the whole population sample, but not in patients with normal flow AS. In low‐flow, low‐gradient (LFLG) AS patients, EV and FV increased from 36 ± 22 to 47 ± 30 cm/s (p < 0.01), and from 29 ± 12 to 40 ± 15 cm/s (p < 0.01), respectively, after TAVI. There was no difference between normal flow and LFLG AS patients in the number of patients who achieved EV ≥ 40 cm/s post‐TAVI (35% versus 47%, p = 0.54, respectively).ConclusionsLAA EV and FV were low prior to TAVI and increased significantly after TAVI only in patients with LFLG AS. © 2016 Wiley Periodicals, Inc. J Clin Ultrasound 44:375–382, 2016
Making the practically impossible “Merely difficult”—Cryogenic FIB lift‐out for “Damage free” soft matter imaging
Authors: Parmenter Christopher D.J. , Fay Michael W. , Hartfield Cheryl , Eltaher Hoda M. 
Published: February 2016

ABSTRACTThe preparation of thinned lamellae from bulk samples for transmission electron microscopy (TEM) analysis has been possible in the focussed ion beam scanning electron microscope (FIB‐SEM) for over 20 years via the in situ lift‐out method. Lift‐out offers a fast and site specific preparation method for TEM analysis, typically in the field of materials science. More recently it has been applied to a low‐water content biological sample (Rubino 2012). This work presents the successful lift‐out of high‐water content lamellae, under cryogenic conditions (cryo‐FIB lift‐out) and using a nanomanipulator retaining its full range of motion, which are advances on the work previously done by Rubino (2012). Strategies are explored for maintaining cryogenic conditions, grid attachment using cryo‐condensation of water and protection of the lamella when transferring to the TEM. Microsc. Res. Tech. 79:298–303, 2016. © 2016 Wiley Periodicals, Inc.
Three‐dimensional reconstruction of black tiger prawn (Penaeus monodon) spermatozoa using serial block‐face scanning electron microscopy
Authors: Feng Tianyi , Paterson Brian D. , Webb Robyn , Johnston Stephen D. 
Published: February 2016

ABSTRACTSerial Block‐Face Scanning Electron Microscopy (SBF‐SEM) was used in this study to examine the ultrastructural morphology of Penaeus monodon spermatozoa. SBF‐SEM provided a large dataset of sequential electron‐microscopic‐level images that facilitated comprehensive ultrastructural observations and three‐dimensional reconstructions of the sperm cell. Reconstruction divulged a nuclear region of the spermatophoral spermatozoon filled with decondensed chromatin but with two apparent levels of packaging density. In addition, the nuclear region contained, not only numerous filamentous chromatin elements with dense microregions, but also large centrally gathered granular masses. Analysis of the sperm cytoplasm revealed the presence of degenerated mitochondria and membrane‐less dense granules. A large electron‐lucent vesicle and “arch‐like” structures were apparent in the subacrosomal area, and an acrosomal core was found in the acrosomal vesicle. The spermatozoal spike arose from the inner membrane of the acrosomal vesicle, which was slightly bulbous in the middle region of the acrosomal vesicle, but then extended distally into a broad dense plate and to a sharp point proximally. This study has demonstrated that SBF‐SEM is a powerful technique for the 3D ultrastructural reconstruction of prawn spermatozoa, that will no doubt be informative for further studies of sperm assessment, reproductive pathology and the spermiocladistics of penaeid prawns, and other decapod crustaceans. J. Morphol. 277:565–574, 2016. © 2016 Wiley Periodicals, Inc.