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https://www.readbyqxmd.com/read/28637351/tuning-surface-chemistry-of-polyetheretherketone-by-gold-coating-and-plasma-treatment
#1
Zdeňka Novotná, Silvie Rimpelová, Petr Juřík, Martin Veselý, Zdeňka Kolská, Tomáš Hubáček, Jakub Borovec, Václav Švorčík
Polyetheretherketone (PEEK) has good chemical and biomechanical properties that are excellent for biomedical applications. However, PEEK exhibits hydrophobic and other surface characteristics which cause limited cell adhesion. We have investigated the potential of Ar plasma treatment for the formation of a nanostructured PEEK surface in order to enhance cell adhesion. The specific aim of this study was to reveal the effect of the interface of plasma-treated and gold-coated PEEK matrices on adhesion and spreading of mouse embryonic fibroblasts...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28637350/structural-peculiarities-of-ion-conductive-organic-inorganic-polymer-composites-based-on-aliphatic-epoxy-resin-and-salt-of-lithium-perchlorate
#2
Liubov Matkovska, Maksym Iurzhenko, Yevgen Mamunya, Igor Tkachenko, Valeriy Demchenko, Volodymyr Synyuk, Andriy Shadrin, Gisele Boiteux
The article is concerned with hybrid amorphous polymers synthesized basing on epoxy oligomer of diglycide aliphatic ester of polyethylene glycol that was cured by polyethylene polyamine and lithium perchlorate salt. Structural peculiarities of organic-inorganic polymer composites were studied by differential scanning calorimetry, wide-angle X-ray spectra, infrared spectroscopic, scanning electron microscopy, elemental analysis, and transmission and reflective optical microscopy. On the one hand, the results showed that the introduction of LiClO4 salt into epoxy polymer leads to formation of the coordinative metal-polymer complexes of donor-acceptor type between central Li(+) ion and ligand...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28637309/anterior-cervical-pseudarthrosis-treated-with-bilateral-posterior-cervical-cages
#3
William Smith, Mark Gillespy, Jason Huffman, Veasna Vong, Bruce M McCormack
BACKGROUND: Pseudarthrosis after anterior cervical discectomy and fusion (ACDF) causes persistent pain and related disability. Posterior revision surgery results in higher healing rates, but is more extensive compared to anterior surgery. OBJECTIVE: To evaluate minimally disruptive, tissue sparing posterior fusion via bilateral placement of posterior cages between the facet joints as an alternative treatment option. METHODS: A retrospective, multicenter, medical chart review was performed and included 25 patients with symptomatic pseudarthrosis after ACDF treated with posterior cervical cages, and in select cases, anterior revision...
June 14, 2017: Operative Neurosurgery (Hagerstown, Md.)
https://www.readbyqxmd.com/read/28637050/ultrasonography-for-the-diagnosis-of-pneumothorax-after-transbronchial-lung-cryobiopsy-in-diffuse-parenchymal-lung-diseases
#4
Luca Viglietta, Riccardo Inchingolo, Cristina Pavano, Sara Tomassetti, Sara Piciucchi, Andrea Smargiassi, Claudia Ravaglia, Alessandra Dubini, Christian Gurioli, Carlo Gurioli, Venerino Poletti
BACKGROUND: Transbronchial lung cryobiopsy (TBLC) can be indicated in diffuse parenchymal lung diseases (DPLDs) when a confident noninvasive diagnosis cannot be made. The 2 most relevant complications of TBLC are bleeding and pneumothorax (PTX). The accuracy of chest ultrasonography (US) for the detection of PTX is higher when compared to chest X-ray (CXR) with reference to computed tomography (CT) scan as a gold standard. OBJECTIVE: We evaluated the accuracy of chest US in detecting PTX after TBLC in patients with DPLDs...
June 22, 2017: Respiration; International Review of Thoracic Diseases
https://www.readbyqxmd.com/read/28636820/experimental-and-theoretical-study-of-ionic-pair-dissociation-in-lithium-ion-linear-polyethyleneimine-polyacrylonitrile-blend-for-solid-polymer-electrolytes
#5
Fernando Pignanelli, Mariano Romero, Ricardo Faccio, Álvaro W Mombrú
Herein, we report the preparation and characterization of novel polymeric blend between linear polyethylene imine (PEI) and polyacrylonitrile (PAN), with the purpose to facilitate the dissociation of lithium perchlorate salt (LiClO4) and thus to enhance Li-ion transport. It is a joint theoretical and experimental procedure for evaluating and thus demonstrating, the lithium salt dissociation. The procedure implies the correlation between theoretical pair distribution function (PDF) and conventional X-rays diffraction (XRD) by means of molecular dynamics (MD) approach...
June 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28636818/critical-temperature-of-1-palmitoyl-2-oleoyl-sn-glycero-3-phosphoethanolamine-monolayers-and-its-possible-biological-relevance
#6
Jordi Hernandez Borrell, Oscar Domenech
Since transmembrane proteins (TMPs) can be obtained with sufficient purity for x-ray diffraction studies more frequently than decades ago, their mechanisms of action may now be elucidated. One of the pending issues is the actual interplay between transmembrane proteins and membrane lipids. There is strong evidence of the involvement of specific lipids with some membrane proteins, such as the potassium crystallographically sited activation channel (KcsA) of Streptomyces lividans and the secondary transporter of lactose LacY of Escherichia coli, the activities of which are associated with the presence of anionic phospholipids such as the phosphatidylglycerol (PG) and phosphatidyethanolamine (PE), respectively...
June 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28636807/targeting-protein-for-xenopus-kinesin-like-protein-2-knockdown-enhances-radiation-sensitivity-of-human-lung-squamous-carcinoma-cell
#7
Jie Yang, Feng Gao, Xinjian Xu, Yuxiang Wang, Shuchai Zhu
Targeting protein for Xenopus kinesin-like protein 2 (TPX2) has been demonstrated to be associated with the tumorigenesis of many cancers. In the present study, we investigated the role and preliminary mechanism of TPX2 in the resistance of lung squamous carcinoma to radiation therapy. The results showed that SK-MES-1R and NCI-H226R cells were more resistant to X-ray irradiation than the parental cells (SK-MES-1 and NCI-H226). Moreover, TPX2 was upregulated in the radioresistant cells compared with the parental cells...
June 21, 2017: Clinical and Experimental Pharmacology & Physiology
https://www.readbyqxmd.com/read/28636805/a-hybrid-phantom-system-for-patient-skin-and-organ-dosimetry-in-fluoroscopically-guided-interventions
#8
David Borrego, Daniel Siragusa, Stephen Balter, Wesley E Bolch
To investigate calibrations for improved estimates of skin dose and to develop software for computing absorbed organ doses for fluoroscopically guided interventions (FGIs) with the use of radiation dose structured reports (RDSR) and the UF/NCI family of hybrid computational phantoms METHODS AND MATERIALS: Institutional review board approval was obtained for this retrospective study in which ten RDSRs were selected for their high cumulative reference air kerma values. Skin doses were computed using the University of Florida's rapid in-clinic peak skin dose algorithm (or UF-RIPSA)...
June 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28636792/mtf-and-dqe-enhancement-using-an-apodized-aperture-x-ray-detector-design
#9
Tomi F Nano, Terenz Escartin, Elina Ismailova, Karim S Karim, Jan Lindstrȍm, Ho Kyung Kim, Ian A Cunningham
PURPOSE: Acquisition of high-quality x-ray images using low patient exposures requires detectors with high detective quantum efficiency (DQE). We describe a novel apodized-aperture pixel (AAP) design that increases high-frequency modulation transfer function (MTF) and DQE values. The AAP design makes a separation of physical sensor elements from image pixels by using very small sensor elements (e.g. 0.010-0.025 mm) to synthesize desired larger image pixels (e.g. 0.1-0.2 mm). METHODS: A cascaded systems model of signal and noise propagation is developed to describe the benefits of the AAP approach in terms of the MTF, Wiener noise power spectrum (NPS) and DQE...
June 21, 2017: Medical Physics
https://www.readbyqxmd.com/read/28636776/facile-synthesis-and-chain-length-dependent-optical-and-structural-properties-of-diketopyrrolopyrrole-based-oligomers
#10
Satish Patil, Tushita Mukhopadhyay, Boregowda Puttaraju, Palas Roy, Jyotishman Dasgupta, Andreas Meyer
Here we report the synthesis, optical properties and solid-state packing of monodisperse oligomers of DPP up to five repeating units. Optical properties of DPP-oligomers in solution and solid state were investigated by a combination of steady-state, and transient spectroscopy. Transient absorption spectroscopy and time-correlated single photon counting (TCSPC) measurements show that the fluorescence lifetime decreases with increase in the oligomer size from monomer to trimer, thereby reaching saturation for pentameric DPP oligomer...
June 21, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28636681/thermally-induced-conformational-changes-and-protein-protein-interactions-of-bovine-serum-albumin-in-aqueous-solution-under-different-ph-and-ionic-strengths-as-revealed-by-saxs-measurements
#11
Dmitry Molodenskiy, Evgeny Shirshin, Tatiana Tikhonova, Andrey Gruzinov, Georgy Peters, Francesco Spinozzi
Thermal-induced conformational changes and protein-protein interactions of bovine serum albumin (BSA) in aqueous solution are assessed by small angle X-ray scattering (SAXS) at two pH values (7.4 and 9.0) and two ionic strengths (0.1 and 0.5). We demonstrate that Guinier analysis in two ranges of the modulus of the scattering vector allows protein melting and aggregation to be monitored simultaneously, thus providing insights into the mechanism of thermal-induced BSA aggregation. Results of the analysis suggest that at room temperature monomeric and dimeric BSA fractions are present in solution...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28636680/unifying-the-microscopic-picture-of-his-containing-turns-from-gas-phase-model-peptides-to-crystallized-proteins
#12
Woon Yong Sohn, Sana Habka, Eric Gloaguen, Michel Mons
The presence in crystallized proteins of a local anchoring between the side chain of a His residue, located in the central position of a γ- or β-turn, and its local main chain environment, was assessed by the comparison of protein structures with relevant isolated model peptides. Gas phase laser spectroscopy, combined with relevant quantum chemistry methods, was used to characterize the γ- and β-turn structures in these model peptides. A conformer-selective NH stretch infrared study provided evidence for the formation in vacuo of two types of short-range H-bonded motifs, labelled ε-6(δ) and δ-(δ)7/π(H), bridging the His side chain (in its gauche+ rotamer) to the neighbouring NH(i) and CO(i) sites of the backbone; each side chain-backbone motif was found to be specific of the tautomer (ε or δ) adopted by the His side chain in its neutral form...
June 21, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28636601/crystal-structure-of-the-potassium-importing-kdpfabc-membrane-complex
#13
Ching-Shin Huang, Bjørn Panyella Pedersen, David L Stokes
Cellular potassium import systems play a fundamental role in osmoregulation, pH homeostasis and membrane potential in all domains of life. In bacteria, the kdp operon encodes a four-subunit potassium pump that maintains intracellular homeostasis, cell shape and turgor under conditions in which potassium is limiting. This membrane complex, called KdpFABC, has one channel-like subunit (KdpA) belonging to the superfamily of potassium transporters and another pump-like subunit (KdpB) belonging to the superfamily of P-type ATPases...
June 21, 2017: Nature
https://www.readbyqxmd.com/read/28636397/a-comparison-of-the-structural-response-to-pressure-of-ils-with-ether-and-alkyl-functionalities
#14
Kamal B Dhungana, Claudio Javier Margulis
The response of ionic liquids to external perturbations including elevated pressure is a topic of current interest for applications such as tribology. Ionic liquids come in many classes, including those that are amphiphilic and some that are mostly polar having either cationic or anionic tails that are functionalized. The current study compares the effect of elevated pressure on two ionic liquids with different types of cationic tail. 1-decyl-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (C10mim+/NTf2-) is amphiphilic whereas isoelectronic ether-functionalized 1-(2-(2-(2-methoxyethoxy)ethoxy)ethyl)-3-methylimidazolium bis(trifluoromethylsulfonyl)amide (C7O3mim+/NTf2-) has cationic tails that are more polar and conformationally different...
June 21, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28636393/lithium-ion-coupled-electron-transfer-rates-in-superconcentrated-electrolytes-exploring-the-bottlenecks-for-fast-charge-transfer-rates-with-limn2o4-cathode-materials
#15
Victoria A Nikitina, Maxim V Zakharkin, Sergey Yu Vassiliev, Lada V Yashina, Evgeny V Antipov, Keith J Stevenson
The charge transfer kinetics of lithium ion intercalation into LixMn2O4 cathode materials was examined in dilute and concentrated aqueous and carbonate LiTFSI solutions using electrochemical methods. Distinctive trends in ion intercalation rates were observed between water-based and ethylene carbonate/diethyl carbonate solutions. The influence of the solution concentration on the rate of lithium ion transfer in aqueous media can be tentatively attributed to the process associated with Mn dissolution, while in carbonate solutions the rate is influenced by the formation of a concentration-dependent solid electrolyte interface (SEI)...
June 21, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28636361/a-machine-learning-assisted-approach-for-discovering-novel-inhibitors-targeting-bromodomain-containing-protein-4
#16
Jing Xing, Wenchao Lu, Rongfeng Liu, Yulan Wang, Yiqian Xie, Hao Zhang, Zhe Shi, Hao Jiang, Yu-Chih Liu, Kaixian Chen, Hualiang Jiang, Cheng Luo, Mingyue Zheng
Bromodomain-containing protein 4 (BRD4) is implicated in the pathogenesis of a number of different cancers, inflammatory diseases and heart failure. Much effort has been dedicated toward discovering novel scaffold BRD4 inhibitors (BRD4is) with different selectivity profiles and potential anti-resistance properties. Structure-based drug design (SBDD) and virtual screening (VS) are the most frequently used approaches. Here, we demonstrate a novel, structure-based VS approach that uses machine-learning algorithms trained on the priori structure and activity knowledge to predict the likelihood that a compound is a BRD4i based on its binding pattern with BRD4...
June 21, 2017: Journal of Chemical Information and Modeling
https://www.readbyqxmd.com/read/28636344/ruthenium-complexes-are-ph-activated-metallo-prodrugs-phamps-with-light-triggered-selective-toxicity-toward-cancer-cells
#17
Fengrui Qu, Seungjo Park, Kristina Martinez, Jessica L Gray, Fathima Shazna Thowfeik, John A Lundeen, Ashley E Kuhn, David J Charboneau, Deidra L Gerlach, Molly M Lockart, James A Law, Katherine L Jernigan, Nicole Chambers, Matthias Zeller, Nicholas A Piro, W Scott Kassel, Russell H Schmehl, Jared J Paul, Edward J Merino, Yonghyun Kim, Elizabeth T Papish
Metallo prodrugs that take advantage of the inherent acidity surrounding cancer cells have yet to be developed. We report a new class of pH-activated metallo prodrugs (pHAMPs) that are activated by light- and pH-triggered ligand dissociation. These ruthenium complexes take advantage of a key characteristic of cancer cells and hypoxic solid tumors (acidity) that can be exploited to lessen the side effects of chemotherapy. Five ruthenium complexes of the type [(N,N)2Ru(PL)](2+) were synthesized, fully characterized, and tested for cytotoxicity in cell culture (1A: N,N = 2,2'-bipyridine (bipy) and PL, the photolabile ligand, = 6,6'-dihydroxybipyridine (6,6'-dhbp); 2A: N,N = 1,10-phenanthroline (phen) and PL = 6,6'-dhbp; 3A: N,N = 2,3-dihydro-[1,4]dioxino[2,3-f][1,10]phenanthroline (dop) and PL = 6,6'-dhbp; 4A: N,N = bipy and PL = 4,4'-dimethyl-6,6'-dihydroxybipyridine (dmdhbp); 5A: N,N = 1,10-phenanthroline (phen) and PL = 4,4'-dihydroxybipyridine (4,4'-dhbp)...
June 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28636343/a-six-coordinate-dysprosium-single-ion-magnet-with-trigonal-prismatic-geometry
#18
Shan-Shan Liu, Yin-Shan Meng, Yi-Quan Zhang, Zhao-Sha Meng, Ke Lang, Zhen-Liang Zhu, Chang-Fang Shang, Bing-Wu Wang, Song Gao
A mononuclar six-coordinate dysprosium complex was synthesized and structurally and magnetically characterized. X-ray structural analyses show trigonal-prismatic coordination geometry of the Dy(III) center. Slow relaxation of magnetization in the absence of a direct-current field and magnetic hysteresis up to 3.0 K could be observed, indicating its single-ion-magnet behavior. Arrhenius fitting and ab initio calculations suggest that the magnetic relaxation process may not occur through the Orbach process at high temperatures under the experimental conditions...
June 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28636342/charge-transfer-properties-of-triarylamine-integrated-dimolybdenum-dyads
#19
Lu Chen, Suman Mallick, Ying Ning Tan, Miao Meng, Chun Y Liu
Three quadruply bonded dimolybdenum complexes equipped with a triarylamine pendant, [(DAniF)3Mo2(μ-O2CC6H4N(C6H4CH3)2] (DAniF = N,N'-di(p-anisyl)formamidinate; [OO-ph-N]), [(DAniF)3Mo2(μ-OSCC6H4N(C6H4CH3)2] ([OS-ph-N]), and [(DAniF)3Mo2(μ-S2CC6H4N(C6H4CH3)2] ([SS-ph-N]), have been synthesized and characterized by single crystal X-ray diffraction. In electrochemical measurements, the redox couple for the organic amine group becomes irreversible, reflecting the substantially strong electronic interaction between the dimetal center and organic redox site...
June 21, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28636341/biochemical-characterization-of-wbkc-an-n-formyltransferase-from-brucella-melitensis
#20
Alexander S Riegert, Daniel P Chantigian, James B Thoden, Peter A Tipton, Hazel M Holden
It has become increasingly apparent within the last several years that unusual N-formylated sugars are often found on the O-antigens of such Gram negative pathogenic organisms as Francisella tularensis, Campylobacter jejuni, and Providencia alcalifaciens, amongst others. Indeed, in some species of Brucella, for example, the O-antigen contains 1,2-linked 4-formamido-4,6-dideoxy-alpha-D-mannosyl groups. These sugars, often referred to as N-formylperosamine, are synthesized in pathways initiating with GDP-mannose...
June 21, 2017: Biochemistry
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