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https://www.readbyqxmd.com/read/28088689/syntheses-structures-and-fluorescence-properties-of-three-rare-earth-containing-docosatungstates
#1
Hailou Li, Yajie Liu, Rui Zheng, Xing Ma, Lijuan Chen, Junwei Zhao
Three rare-earth containing docosatungstates Na3H2[RE(H2O)4][RE(H2O)5]2[W22O74H2]·36H2O [RE=Dy(III) (1), Ho(III) (2), Y(III) (3)] have been synthesized by reaction of Na2WO4·2H2O, dimethylamine hydrochloride (DMAHC) and RE(NO3)3·6H2O in the aqueous solution and characterized by elemental analyses, IR spectra, thermogravimetric (TG) analysis, powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. 1-3 are isomorphous and each molecular unit consists of a S-shaped docosatungstate [W22O74H2](14-) polyoxoanion with two supporting [RE(H2O)5](3+) cations and one disordered [RE(H2O)4](3+) cation...
January 9, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28088447/differential-binding-of-monovalent-cations-to-kcsa-deciphering-the-mechanisms-of-potassium-channel-selectivity
#2
Estefanía Montoya, M Lourdes Renart, A Marcela Giudici, José A Poveda, Asia M Fernández, Andrés Morales, José M González-Ros
This work explores whether the ion selectivity and permeation properties of a model potassium channel, KcsA, could be explained based on ion binding features. Non-permeant Na(+) or Li(+) bind with low affinity (millimolar KD's) to a single set of sites contributed by the S1 and S4 sites seen at the selectivity filter in the KcsA crystal structure. Conversely, permeant K(+), Rb(+), Tl(+) and even Cs(+) bind to two different sets of sites as their concentration increases, consistent with crystallographic evidence on the ability of permeant species to induce concentration-dependent transitions between conformational states (non-conductive and conductive) of the channel's selectivity filter...
January 11, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28088077/rhoa-knockdown-by-cationic-amphiphilic-copolymer-sirhoa-polyplexes-enhances-axonal-regeneration-in-rat-spinal-cord-injury-model
#3
So-Jung Gwak, Christian Macks, Da Un Jeong, Mark Kindy, Michael Lynn, Ken Webb, Jeoung Soo Lee
Spinal cord injury (SCI) results in permanent loss of motor and sensory function due to developmentally-related and injured-induced changes in the extrinsic microenvironment and intrinsic neuronal biochemistry that limit plasticity and axonal regeneration. Our long term goal is to develop cationic, amphiphilic copolymers (poly (lactide-co-glycolide)-g-polyethylenimine, PgP) for combinatorial delivery of therapeutic nucleic acids (TNAs) and drugs targeting these different barriers. In this study, we evaluated the ability of PgP to deliver siRNA targeting RhoA, a critical signaling pathway activated by multiple extracellular inhibitors of axonal regeneration...
January 3, 2017: Biomaterials
https://www.readbyqxmd.com/read/28088025/residues-of-2-hydroxy-3-phenylpyrazine-a-degradation-product-of-some-%C3%AE-lactam-antibiotics-in-environmental-water-in-vietnam
#4
Nguyen Van Sy, Kazuo Harada, Megumi Asayama, Minae Warisaya, Le Hong Dung, Yoshinori Sumimura, Khong Thi Diep, Le Viet Ha, Nguyen Nam Thang, Tran Thi Tuyet Hoa, Tran Minh Phu, Pham Ngoc Khai, Nguyen Thanh Phuong, Le Danh Tuyen, Yoshimasa Yamamoto, Kazumasa Hirata
Antibiotic-resistant bacteria have become a serious problem worldwide, caused in part by the excessive use and discharge of antibiotics into the environment. Ampicillin (ABPC) is a widely used antibiotic. However, this chemical rapidly decomposes in water containing divalent cations like Ca(2+) and Mg(2+), thus, detection of ABPC in environmental water is difficult. This study was carried out to evaluate the presence of 2-hydroxy-3-phenylpyrazine (HPP), one of the degradation products of ABPC and β-lactam antibiotics with an ABPC substructure, in environmental water...
January 2, 2017: Chemosphere
https://www.readbyqxmd.com/read/28087882/cooperatively-interlocked-2-1-type-%C3%AF-system-anion-complexes
#5
Ryohei Yamakado, Yukina Ashida, Ryuma Sato, Yasuteru Shigeta, Nobuhiro Yasuda, Hiromitsu Maeda
As fascinating examples of closely connected multiple π-electronic systems involving noncovalent interactions, the cooperatively interlocked [2+1]-type anion complexes of well-designed π-electronic molecules are reported. The anion-responsive π-electronic molecules investigated in this study are the boron complexes of dipyrrolyldiketones bearing arylethynyl moieties at the pyrrole α-positions. Diverse substituents were introduced at the terminal aryl moieties, thus controlling the cooperativity to form [2+1]-type complexes...
January 14, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28087761/proteomics-technologies-and-their-applications
#6
REVIEW
Bilal Aslam, Madiha Basit, Muhammad Atif Nisar, Mohsin Khurshid, Muhammad Hidayat Rasool
Proteomics involves the applications of technologies for the identification and quantification of overall proteins present content of a cell, tissue or an organism. It supplements the other "omics" technologies such as genomic and transcriptomics to expound the identity of proteins of an organism, and to cognize the structure and functions of a particular protein. Proteomics-based technologies are utilized in various capacities for different research settings such as detection of various diagnostic markers, candidates for vaccine production, understanding pathogenicity mechanisms, alteration of expression patterns in response to different signals and interpretation of functional protein pathways in different diseases...
February 2017: Journal of Chromatographic Science
https://www.readbyqxmd.com/read/28087488/cathepsin-k-targeted-sub-micron-particles-for-regenerative-repair-of-vascular-elastic-matrix
#7
Brenton Jennewine, Jonathan Fox, Anand Ramamurthi
: Abdominal Aortic Aneurysms (AAA) involve slow dilation and weakening of the aortic wall due to breakdown of structural matrix components, such as elastic fibers by chronically overexpressed matrix metalloproteinases (MMPs), primarily, MMPs-2 and -9. Auto-regenerative repair of disrupted elastic fibers by smooth muscle cells (SMCs) at the AAA site is intrinsically poor and together with chronic proteolysis prevents restoration of elastin homeostasis, necessary to enable AAA growth arrest or regression to a healthy state...
January 10, 2017: Acta Biomaterialia
https://www.readbyqxmd.com/read/28087478/renal-involvement-in-lysinuric-protein-intolerance-contribution-of-pathology-to-assessment-of-heterogeneity-of-renal-lesions
#8
Emmanuel Estève, Pauline Krug, Aurélie Hummel, Jean-Baptiste Arnoux, Olivia Boyer, Anais Brassier, Pascale de Lonlay, Vincent Vuiblet, Stéphanie Gobin, Rémi Salomon, Christine Piètrement, Jean-Paul Bonnefont, Aude Servais, Louise Galmiche
Lysinuric protein intolerance (LPI) is a rare autosomal recessive disease caused by mutations in the SLC7A7 gene encoding the light subunit of a cationic amino acid transporter. Symptoms mimic primary urea cycle defects but dysimmune symptoms are also described. Renal involvement in LPI was first described in the 1980's. In 2007, it appeared that it could concern as much as 75% of LPI patients and could lead to end stage renal disease. The most common feature is proximal tubular dysfunction and nephrocalcinosis but glomerular lesions are also reported...
January 10, 2017: Human Pathology
https://www.readbyqxmd.com/read/28087374/what-stoichiometries-determined-by-mass-spectrometry-reveal-about-the-ligand-binding-mode-to-g-quadruplex-nucleic-acids
#9
Michael J Lecours, Adrien Marchand, Ahdia Anwar, Corinne Guetta, W Scott Hopkins, Valérie Gabelica
G-quadruplexes (G4s) have become important drug targets to regulate gene expression and telomere maintenance. Many studies on G4 ligand binding focus on determining the ligand binding affinities and selectivities. Ligands, however, can also affect the G4 conformation. Here we explain how to use electrospray ionization mass spectrometry (ESI-MS) to monitor simultaneously ligand binding and cation binding stoichiometries. The changes in potassium binding stoichiometry upon ligand binding hint at ligand-induced conformational changes involving a modification of the number of G-quartets...
January 10, 2017: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/28087354/effect-of-piroxicam-on-lipid-membranes-drug-encapsulation-and-gastric-toxicity-aspects
#10
Natalia Wilkosz, Sami Rissanen, Małgorzata Cyza, Renata Szybka, Maria Nowakowska, Alex Bunker, Tomasz Róg, Mariusz Kepczynski
Uptake of piroxicam, a non-steroidal anti-inflammatory drug, from the intestines after oral intake is limited due to its low solubility and its wide use is associated with several side effects related to the gastrointestinal tract. In this study, all-atom molecular dynamics (MD) simulations and fluorescent spectroscopy were employed to investigate the interaction of piroxicam in neutral, zwitterionic, and cationic forms with lipid bilayers composed of phosphatidylcholine, cholesterol, and PEGylated lipids. Our study was aimed to assess the potential for encapsulation of piroxicam in liposomal carriers and to shed more light on the process of gastrointestinal tract injury by the drug...
January 10, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28086263/observation-of-the-ring-puckering-vibrational-mode-in-thietane-cation
#11
Yu Ran Lee, Chung Bin Park, Jiye Hwang, Bongjune Sung, Hong Lae Kim, Chan Ho Kwon
We have measured the high-resolution vibrational spectra of a thietane (trimethylene sulfide) cation in the gas phase by employing the vacuum ultraviolet mass-analyzed threshold ionization (VUV-MATI) spectroscopic technique. Peaks in the low frequency region of the observed MATI spectrum of thietane originate from a progression of the ring puckering vibrational mode (typical in small heterocyclic molecules), which is successfully reproduced by quantum chemical calculations with one-dimensional (1D) symmetric double-well potentials along the ring puckering coordinates on both the S0 and D0 states, the ground electronic states of neutral and cation of thietane, respectively...
January 13, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28081459/targeted-delivery-of-in-situ-pcr-amplified-sleeping-beauty-transposon-genes-to-cancer-cells-with-lipid-based-nanoparticle-like-protocells
#12
Kun Ma, Duo Fu, Dongli Yu, Changhao Cui, Li Wang, Zhaoming Guo, Chuanbin Mao
A Sleeping Beauty (SB) transposon system is made of a transposon plasmid (containing gene encoding a desired functional or therapeutic protein) and a transposase plasmid (encoding an enzyme capable of cutting and pasting the gene into the host cell genome). It is a kind of natural, nonviral gene delivery vehicle, which can achieve efficient genomic insertion, providing long-term transgenic expression. However, before the SB transposon system could play a role in promoting gene expression, it has to be delivered efficiently first across cell membrane and then into cell nuclei...
January 2, 2017: Biomaterials
https://www.readbyqxmd.com/read/28081456/robust-tough-and-anti-fatigue-cationic-latex-composite-hydrogels-based-on-dual-physically-cross-linked-networks
#13
Song Gu, Lijie Duan, Xiuyan Ren, Guang Hui Gao
Dual physically cross-linked hydrogels, which are triggered by cationic latexes as hydrophobic association and ionic crosslinking centers, were easily fabricated via a one-pot in situ polymerization method. First, the hydrophobic alkyl chains of hydrophobic monomers are adsorbed on the surface of latex microspheres and stabilized in the presence of surfactants, forming hydrophobic association centers as the first physical crosslinking points. Meanwhile, the anionic sulfate radicals dissociated by persulphate are attracted towards the cationic molecular chains of latex microspheres through ionic interactions, forming the secondary physical crosslinking centers, and initiate the copolymerization between acrylamide and hydrophobic vinyl monomers...
January 4, 2017: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/28081185/upregulated-expression-of-transient-receptor-potential-cation-channel-subfamily-v-receptors-in-mucosae-of-patients-with-oral-squamous-cell-carcinoma-and-patients-with-a-history-of-alcohol-consumption-or-smoking
#14
Akiko Sakakibara, Shunsuke Sakakibara, Junya Kusumoto, Daisuke Takeda, Takumi Hasegawa, Masaya Akashi, Tsutomu Minamikawa, Kazunobu Hashikawa, Hiroto Terashi, Takahide Komori
OBJECTIVES: Transient receptor potential cation channel (subfamily V, members 1-4) (TRPV1-4) are expressed in skin and neurons and activated by external stimuli in normal mucosae of all oral cavity sites. The oral cavity is exposed to various stimuli, including temperature, mechanical stimuli, chemical substances, and changes in pH, and, notably, the risk factors for oncogenic transformation in oral squamous epithelium are the same as the external stimuli received by TRPV1-4 receptors...
2017: PloS One
https://www.readbyqxmd.com/read/28080040/insights-into-thiol-aromatic-interactions-a-stereoelectronic-basis-for-s-h-%C3%AF-interactions
#15
Christina R Forbes, Sudipta Kumar Sinha, Himal Kanti Ganguly, Shi Bai, Glenn P A Yap, Sandeep Patel, Neal J Zondlo
Thiols can engage favorably with aromatic rings in S-H/π interactions, within abiological systems and within proteins. However, the underlying bases for S-H/π interactions are not well understood. The crystal structure of Boc-L-4-thiolphenylalanine tert-butyl ester revealed crystal organization centered on the interaction of the thiol S-H with the aromatic ring of an adjacent molecule, with a through-space Hthiol...Caromatic distance of 2.71 Å, below the 2.90 Å sum of the van der Waals radii of H and C...
January 12, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28079959/removal-of-multiple-contaminants-from-water-by-polyoxometalate-supported-ionic-liquid-phases-pom-silps
#16
Sven Herrmann, Laura De Matteis, Jesús M de la Fuente, Scott G Mitchell, Carsten Streb
The simultaneous removal of organic, inorganic, and microbial contaminants from water by one material offers significant advantages when fast, facile, and robust water purification is required. Herein, we present a supported ionic liquid phase (SILP) composite where each component targets a specific type of water contaminant: a polyoxometalate-ionic liquid (POM-IL) is immobilized on porous silica, giving the heterogeneous SILP. The water-insoluble POM-IL is composed of antimicrobial alkylammonium cations and lacunary polyoxometalate anions with heavy-metal binding sites...
January 12, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28079955/solubilization-of-membrane-proteins-into-functional-lipid-bilayer-nanodiscs-using-a-diisobutylene-maleic-acid-copolymer
#17
Abraham Olusegun Oluwole, Bartholomäus Danielczak, Annette Meister, Jonathan Oyebamiji Babalola, Carolyn Vargas, Sandro Keller
Once removed from their natural environment, membrane proteins depend on membrane-mimetic systems to retain their native structures and functions. To this end, lipid-bilayer nanodiscs that are bounded by scaffold proteins or amphiphilic polymers such as styrene/maleic acid (SMA) copolymers have been introduced as alternatives to detergent micelles and liposomes for in vitro membrane-protein research. Herein, we show that an alternating diisobutylene/maleic acid (DIBMA) copolymer shows equal performance to SMA in solubilizing phospholipids, stabilizes an integral membrane enzyme in functional bilayer nanodiscs, and extracts proteins of various sizes directly from cellular membranes...
January 12, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28079383/structure-and-interaction-in-ph-dependent-phase-behavior-of-nanoparticle-protein-systems
#18
Indresh Yadav, Sugam Kumar, Vinod K Aswal, Joachim Kohlbrecher
The pH-dependent structure and interaction of anionic silica nanoparticles (diameter 18 nm) with two globular model proteins-lysozyme and bovine serum albumin (BSA) have been studied. Cationic lysozyme adsorbs strongly on the nanoparticles and the adsorption follows an exponential growth as a function of lysozyme concentration, where the saturation value increases with pH approaching towards the isoelectric point (IEP) of lysozyme. In contrast, irrespective of the pH, anionic BSA does not show any adsorption...
January 12, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28079362/intensive-study-on-catalytical-behavior-of-n-methylphenothiazine-as-a-soluble-mediator-to-oxidize-li2o2-cathode-of-li-o2-battery
#19
Ningning Feng, Xiaowei Mu, Xueping Zhang, Ping He, Haoshen Zhou
Aprotic Li-O2 batteries have attracted worldwide interest owing to their ultra-high theoretical energy density. However, the practical Li-O2 batteries still suffer from high charge overpotential and low energy efficiency resulting from the sluggish kinetics in electrochemically oxidizing the insulating lithium peroxide (Li2O2). Recently, dissolved redox mediators in the electrolyte have enabled the effective catalytic oxidation of Li2O2 at the liquid-solid interface. Here, we report that the incorporation of N-methylphenothiazine (MPT), as a redox shuttle in Li-O2 batteries, provides a dramatic reduction in charge overpotential to 0...
January 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28079307/coordination-of-krf2-to-a-naked-metal-cation-mg-2
#20
Matic Lozinšek, Hélène P A Mercier, David S Brock, Boris Žemva, Gary J Schrobilgen
Examples of coordination compounds in which KrF2 functions as a ligand are very rare. In contrast, XeF2 provides a rich coordination chemistry with a variety of main-group and transition metal cations. The reactions of Mg(AsF6 )2 and KrF2 in HF or BrF5 solvent have afforded [Mg(KrF2 )4 (AsF6 )2 ] and [Mg(KrF2 )4 (AsF6 )2 ]⋅2 BrF5 , respectively, the first examples of a metal cation ligated by KrF2 . Their X-ray crystal structures and Raman spectra show that the KrF2 ligands and [AsF6 ](-) anions are F-coordinated to a naked Mg(2+) cation...
January 12, 2017: Angewandte Chemie
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