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https://www.readbyqxmd.com/read/28224673/orthogonal-click-postfunctionalization-of-alternating-copolymers-prepared-by-nitroxide-mediated-polymerization
#1
Matthias Tesch, Sergej Kudruk, Matthias Letzel, Armido Studer
Nitroxide Mediated Polymerization (NMP) was applied to prepare alternating copolymers using 1,1,1,3,3,3-hexafluoroisopropyl acrylate (HFIPA) 1 and ((6-trimethylsilyl)-hex-5-yn-1-yl)vinyl ether (THVE) 2 as monomers. The alternating sequence of the resulting poly(HFIPA-alt-THVE) 3 was proved via tandem mass spectrometry (MS/MS) and further supported by 1H NMR spectroscopy. Alternating alkyne and activated ester moieties of copolymer 3 were further functionalized with organic azides and amines using sequential Cu-catalyzed azide-alkyne click (CuAAC) and amidation reactions, providing dually functionalized poly(acrylamide-alt-triazole) polymers 5...
February 22, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28221772/desleucyl-oritavancin-with-a-damaged-d-ala-d-ala-binding-site-inhibits-the-transpeptidation-step-of-cell-wall-biosynthesis-in-whole-cells-of-staphylococcus-aureus
#2
Sung Joon Kim, Manmilan Singh, Shasad Sharif, Jacob Schaefer
We have used solid-state NMR to characterize the exact nature of the dual mode of action of oritavancin in preventing cell-wall assembly in Staphylococcus aureu. Measurements performed on whole cells labeled selectively in vivo have established that des-N-methylleucyl-N-4-(4-fluorophenyl)benzyl-chloroeremomycin, an Edman degradation product of [19F]oritavancin, which has a damaged D-Ala-D-Ala binding aglycon, is a potent inhibitor of the transpeptidase activity of cell-wall biosynthesis. The desleucyl-drug binds to partially cross-linked peptidoglycan by a cleft formed between the drug aglycon and its biphenyl hydrophobic sidechain...
February 21, 2017: Biochemistry
https://www.readbyqxmd.com/read/28216405/design-synthesis-and-biological-evaluation-of-nonsecosteroidal-vitamin-d3-receptor-ligands-as-anti-tumor-agents
#3
Bin Wang, Meixi Hao, Can Zhang
1α,25-dihydroxyvitamin D3 (1,25-(OH)2D3, also known as calcitriol), the active form of vitamin D3, is being increasingly recognized for cancer therapy. Our previous work showed that phenyl-pyrrolyl pentane analogs, which mimicked anti-proliferative activities against several cancer cell lines of the natural secosteroidal ligand 1,25-(OH)2D3. Here, in order to optimize the structural features and discover more potent derivative, a series of nonsecosteroidal vitamin D3 receptor (VDR) ligands bearing acetylene bond linker was designed, synthesized and evaluated...
February 1, 2017: Bioorganic & Medicinal Chemistry Letters
https://www.readbyqxmd.com/read/28215915/serotype-distribution-and-antimicrobial-susceptibility-of-streptococcus-pneumoniae-isolates-from-adult-patients-in-jakarta-indonesia
#4
Wahyu Finasari Said, Edy Sukoto, Miftahuddin Majid Khoeri, July Kumalawati, Dodi Safari
Currently, the data on pneumococcal invasive disease in the Indonesian population are limited. In this study, we investigated the serotype distribution and antimicrobial susceptibility of Streptococcus pneumoniae. These samples were isolated from the sputum of adult patients with non-specific clinical symptoms aged 18-87 years in Jakarta, Indonesia, from August to October 2014. Of the 349 sputum specimens, thirteen isolates were identified as S. pneumoniae strains (4%), with two strains each for serotype 19F, 3, and 15A, and one strain each for serotype/serogroup 13, 23A, 6, 34, 17F, 16F, and untypeable...
February 16, 2017: Journal of Infection and Public Health
https://www.readbyqxmd.com/read/28198587/hexaphyrin-as-a-potential-theranostic-dye-for-photothermal-therapy-and-19f-magnetic-resonance-imaging
#5
Tomohiro Higashino, Hirotaka Nakatsuji, Ryosuke Fukuda, Haruki Okamoto, Hirohiko Imai, Tetsuya Matsuda, Hidehito Tochio, Masahiro Shirakawa, Nikolai Tkachenko, Mitsuru Hashida, Tatsuya Murakami, Hiroshi Imahori
meso-Aryl substituted expanded porphyrins have two potential key features suitable for theranostic agents, excellent absorption in near infrared (NIR) region and possible introduction of multiple fluorine atoms at structurally nearly equivalent positions. Herein, hexaphyrin (hexa) was synthesized using 2,6-bis(trifluoromethyl)-4-formyl benzoate and pyrrole and evaluated as a novel theranostic expanded porphyrin possessing the above key features. Under NIR light illumination hexa showed intense photothermal and weak photodynamic effects, which were most likely due to its low-lying excited states close to a singlet oxygen...
February 15, 2017: Chembiochem: a European Journal of Chemical Biology
https://www.readbyqxmd.com/read/28195380/small-molecule-mixture-analysis-by-heteronuclear-nmr-under-spin-diffusion-conditions-in-the-viscous-dmso-water-solvent
#6
Pedro Lameiras, Solène Patis, Jouda Jakhlal, Stéphanie Castex, Pascale Clivio, Jean-Marc Nuzillard
Spin diffusion in NMR occurs for small and medium-sized molecules when their tumbling rate reduces in solution so that magnetization exchange by longitudinal cross relaxation becomes highly efficient. Composite DMSO-water viscous solvents were used for the first time to access the individual NMR spectra of mixture components in spin diffusion conditions. The easy handling and high dissolution power of [D6]DMSO/H2O offers a wide range of potential applications for polar and apolar mixture analysis. In addition to 2D 1H-1H NOESY and 1H-13C HSQC-NOESY, 1H-15N HSQC-NOESY, 1D and 2D 1H-19F HOESY experiments were set up to offer new ways to individualize molecules within a mixture...
February 13, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28187060/risk-factors-in-children-older-than-5-years-with-pneumococcal-meningitis-data-from-a-national-network
#7
Fanny Hénaff, Corinne Levy, Robert Cohen, Capucine Picard, Emmanuelle Varon, Christèle Gras Le Guen, Elise Launay
INTRODUCTION: The occurrence of meningitis in children > 5 years old may be associated with specific predisposing factors that can be anatomic, such as cerebrospinal fluid (CSF) fistula or breach, or related to genetic susceptibility or N inborn or acquired immunologic defect. This study aimed to assess the anatomical and immunologic risk factors in children > 5 years old with pneumococcal meningitis and prospectively enrolled in the French national meningitis network. METHODS: We analyzed all data for children 5 to 15 years old with a diagnosis of pneumococcal meningitis between 2001 and 2013...
December 13, 2016: Pediatric Infectious Disease Journal
https://www.readbyqxmd.com/read/28180296/characterization-of-human-telomere-rna-g-quadruplex-structures-in-vitro-and-in-living-cells-using-19f-nmr-spectroscopy
#8
Hong-Liang Bao, Takumi Ishizuka, Takashi Sakamoto, Kenzo Fujimoto, Tamayo Uechi, Naoya Kenmochi, Yan Xu
No abstract text is available yet for this article.
February 9, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28178935/pneumococcal-carriage-among-hiv-infected-children-in-accra-ghana
#9
Eric S Donkor, Jennifer A Annan, Ebenezer V Badoe, Nicholas T K D Dayie, Appiah-Korang Labi, Hans-Christian Slotved
BACKGROUND: Pneumococcal carriage is the precursor for development of pneumococcal disease, and is also responsible for transmission of the organism from person-to-person. In Africa, little is known about the pneumococcus in relation to people with HIV infection. The aim of the study was to investigate the epidemiology of pneumococcal carriage among HIV infected children visiting a tertiary hospital in Ghana, including the carriage prevalence, risk factors and serotype distribution. METHOD: This was a cross sectional study carried out from February to May, 2015 at the HIV Paediatric Clinic of the Korle-Bu Teaching Hospital in Accra, Ghana...
February 8, 2017: BMC Infectious Diseases
https://www.readbyqxmd.com/read/28178138/etiology-of-acute-otitis-media-and-serotype-distribution-of-streptococcus-pneumoniae-and-haemophilus-influenzae-in-chilean-children-5-years-of-age
#10
Andres Rosenblut, Carla Napolitano, Angelica Pereira, Camilo Moreno, Devayani Kolhe, Alejandro Lepetic, Eduardo Ortega-Barria
The impact of bacterial conjugate vaccines on acute otitis media (AOM) is affected by several factors including population characteristics, bacterial etiology and vaccine conjugation method, carrier, and coverage. This study estimated the baseline etiology, distribution, and antibiotic susceptibility of bacterial serotypes that causes AOM in children aged <5 years in a public setting in Santiago, Chile.Children aged ≥3 months and <5 years referred to the physician for treatment of AOM episodes (with an onset of symptoms <72 h) were enrolled between September 2009 and September 2010...
February 2017: Medicine (Baltimore)
https://www.readbyqxmd.com/read/28165731/a-novel-experimental-modeling-approach-to-characterize-perfluorinated-surfactants-in-soils
#11
Denis Courtier-Murias, Eric Michel, Stéphane Rodts, François Lafolie
Soil contamination is still poorly understood and modeled in part due to the difficulties of looking inside the "black box" constituted by soils. Here, we investigated the application of a recently developed 1H NMR technique to 19F NMR relaxometry experiments and utilized the results as inputs for an existing model. This novel approach yields 19F T2 NMR relaxation values of any fluorinated contaminant, which are among the most dangerous ones, allowing us to non-invasively and directly monitor their fate in soils...
February 6, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28165218/perfluoro-tert-butyl-homoserine-is-a-helix-promoting-highly-fluorinated-nmr-sensitive-aliphatic-amino-acid-detection-of-the-estrogen-receptor%C3%A2-coactivator-protein-protein-interaction-by-19-f-nmr
#12
Caitlin M Tressler, Neal J Zondlo
Highly fluorinated amino acids can stabilize proteins and complexes with proteins, via enhanced hydrophobicity, and provide novel methods for identification of specific molecular events in complex solutions, via selective detection by (19)F NMR and the absence of native (19)F signals in biological contexts. However, the potential applications of (19)F NMR in probing biological processes are limited both by the strong propensities of most highly fluorinated amino acids for the extended conformation and by the relatively modest sensitivity of NMR spectroscopy, which typically constrains measurements to mid-micromolar concentrations...
February 15, 2017: Biochemistry
https://www.readbyqxmd.com/read/28146590/epidemiology-of-otitis-media-with-spontaneous-perforation-of-the-tympanic-membrane-in-young-children-and-association-with-bacterial-nasopharyngeal-carriage-recurrences-and-pneumococcal-vaccination-in-catalonia-spain-the-prospective-hermes-study
#13
Robert Cilveti, Montserrat Olmo, Josefa Pérez-Jove, Juan-José Picazo, Josep-Lluis Arimany, Emiliano Mora, Tomás M Pérez-Porcuna, Ignacio Aguilar, Aurora Alonso, Francesc Molina, María Del Amo, Cristina Mendez
The Epidemiology of otitis media with spontaneous perforation of the tympanic membrane and associated nasopharyngeal carriage of bacterial otopathogens was analysed in a county in Catalonia (Spain) with pneumococcal conjugate vaccines (PCVs) not included in the immunization programme at study time. A prospective, multicentre study was performed in 10 primary care centres and 2 hospitals (June 2011-June 2014), including all otherwise healthy children ≥2 months ≤8 years with otitis media presenting spontaneous tympanic perforation within 48h...
2017: PloS One
https://www.readbyqxmd.com/read/28135800/dual-mode-of-action-for-plusbacin-a3-in-staphylococcus-aureus
#14
Robert D O'Connor, Manmilan Singh, James Chang, Sung Joon Kim, Michael VanNieuwenhze, Jacob Schaefer
We have used C{F}, N{F}, and N{P} rotational-echo double resonance NMR to determine the location and conformation of (19)F and (15)N double-labeled plusbacin A3 and of double-labeled deslipo-plusbacin A3, each bound to the cell walls of whole cells of Staphyloccocus aureus grown in media containing [1-(13)C]glycine. The (31)P is primarily in wall teichoic acid. Approximately 25% of plusbacin headgroups (the cyclic depsipeptide backbone) are in a closed conformation (N-F separation of 6 Å), while 75% are in a more open conformation (N-F separation of 12 Å)...
February 13, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28131730/distribution-of-capsular-types-and-drug-resistance-patterns-of-invasive-pediatric-streptococcus-pneumoniae-isolates-in-teheran-iran
#15
Hamidreza Houri, Abdolah Karimi, Yasaman Saee, Fatemeh Fallah, Mohamad Rahbar, Sedigheh Rafiei Tabatabaei
OBJECTIVES: To explore the serotype distribution and drug resistance patterns of invasive pneumococcal isolates from children under 5 years of age. METHODS: During a 32-month period, 585 clinical samples (including blood, cerebrospinal fluid (CSF), and synovial fluid) from children suspected of having meningitis, sepsis, pneumonia, or septic arthritis were analyzed using the BACTEC culture system. Positive cultures were examined using biochemical tests and lytA amplification for the identification of pneumococcal strains...
January 25, 2017: International Journal of Infectious Diseases: IJID
https://www.readbyqxmd.com/read/28125588/comparison-of-serotype-prevalence-of-pneumococci-isolated-from-middle-ear-lower-respiratory-tract-and-invasive-disease-prior-to-vaccination-in-iceland
#16
Martha Á Hjálmarsdóttir, Sigríður Júlía Quirk, Gunnsteinn Haraldsson, Helga Erlendsdóttir, Ásgeir Haraldsson, Karl G Kristinsson
BACKGROUND: Information on pneumococcal serotype distribution before vaccination is a prerequisite for evaluation of vaccine effect. The aim was to investigate the prevalence of pneumococcal serotypes isolated from middle ear (ME), lower respiratory tract (LRT) and from invasive disease (IPD) in Iceland prior to implementation of ten-valent pneumococcal Haemophilus influenzae protein D conjugate vaccine (PHiD-CV-10) into the infant vaccination program (April 2011). METHODS AND FINDINGS: All isolates cultured 2007-2011 from ME, LRT and IPD identified as pneumococci were serotyped and tested for susceptibility at the Clinical Microbiology Department, Landspitali University Hospital that serves approximately 85% of the Icelandic population...
2017: PloS One
https://www.readbyqxmd.com/read/28124906/radiation-effect-of-carboxyl-functionalized-task-specific-ionic-liquids-on-uo22-removal-experimental-study-with-dft-validation
#17
Yinyong Ao, Jian Chen, Yue Wang, Hongbing Chen, Jiuqiang Li, Maolin Zhai
Experimental study with DFT validation about effect of radiation on 1-carboxymethyl-3-methylimidazolium bis(trifluoromethylsulfonyl) imide ([HOOCCH2MIM][NTf2]) as solvent and extractant in rapid homogeneous extraction of UO22+ were performed for the first time. The radiolytic products of the anions and cations of [HOOCCH2MIM][NTf2] were identified by 19F NMR and high-resolution ESI-MS, respectively, and they were attributed to a decrease in UO22+ partitioning. Experimental study with DFT validation for the complexing reactions between [HOOCCH2MIM][NTf2] and radiolytic products proved that F- competition was one of the main reasons for the decrease in UO22+ partitioning...
January 26, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28124793/fluoroacetamide-moieties-as-nmr-probes-for-molecular-recognition-of-glcnac-containing-sugars-modulation-of-the-ch-%C3%AF-stacking-interactions-by-different-fluorination-patterns
#18
Luca Unione, Maria Alcalá, Begoña Echeverria, Sonia Serna, Ana Ardá, Antonio Franconetti, Javier Cañada, Tammo Diercks, Niels Reichardt, Jesus Jimenez-Barbero
We herein propose the use of the fluoroacetamide and difluoroacetamide moieties as sensitive tags for detecting sugar-protein interactions by simple 1H and/or 19F NMR methods. As selected process, we have chosen the binding of N,N'-diacetyl chitobiose, a ubiquitous disaccharide fragment in glycoproteins, by wheat germ agglutinin (WGA), a model lectin. Using STD-NMR, we experimentally demonstrate that, under solution conditions, the molecule containing the CHF2-CO-NH- moiety is the stronger aromatic binder, followed by the analogue with the CH2F-CO-NH- group and the natural molecule (with the CH3-CO-NH- fragment)...
January 26, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28121419/poly-vinylidene-fluoride-containing-phosphonic-acid-as-anticorrosion-coating-for-steel
#19
Sanjib Banerjee, Mohammad Wehbi, Abdellatif Manseri, Ahmad Mehdi, Ali Alaaeddine, Ali Hachem, Bruno Ameduri
Vinylidene fluoride (VDF)-based copolymers bearing pendant phosphonic acid function for potential application as anticorrosion coatings were synthesized via free radical copolymerization of VDF with a new phosphorus containing 2-trifluoromethacrylate monomer, (dimethoxyphosphoryl)methyl 2-(trifluoromethyl)acrylate (MAF-DMP). MAF-DMP was prepared from 2-trifluoromethacrylic acid in 60% overall yield. Radical copolymerizations of VDF with MAF-DMP initiated by tert-amyl peroxy-2-ethylhexanoate at varying ([VDF]0/[MAF-DMP]0) feed ratios led to several poly(VDF-co-MAF-DMP) copolymers having different molar percentages of VDF (79-96%) and number-average molecular weights (Mn's) up to ca...
February 8, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28119123/a-novel-injectable-formulation-of-6-fluoro-l-dopa-imaging-agent-for-diagnosis-of-neuroendocrine-tumors-and-parkinson-s-disease
#20
Adriana Trapani, Domenico Tricarico, Antonietta Mele, Fatima Maqoud, Delia Mandracchia, Paola Vitale, Vito Capriati, Giuseppe Trapani, Vincenzo Dimiccoli, Anna Tolomeo, Antonio Scilimati
Two [19F]F-l-DOPA (F-DOPA) new β-cyclodextrin (CD)-based dosage forms (FA and FB, respectively) have been studied and their physico-chemical and pharmacological features determined to overcome the administration site reactions showed by the currently used [18F]F-l-DOPA formulation (IASOdopa(®)) to perform PET-CT diagnosis in oncology (neuroendocrine tumors) and neurological (Parkinson's disease) field. Chemical stability of FA and FB was found to be longer than IASOdopa(®) by adding the thiol-antioxidant agent, L-Cysteine...
January 21, 2017: International Journal of Pharmaceutics
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