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https://www.readbyqxmd.com/read/28821150/functionalized-alginate-with-liquid-like-behaviors-and-its-application-in-wet-spinning
#1
Zhen Sang, Wenqian Zhang, Zhiyuan Zhou, Huakang Fu, Yeqiang Tan, Kunyan Sui, Yanzhi Xia
Alginate is a kind of marine-derived plant polysaccharide with useful properties including inherent flame-retardancy and biocompatibility, yet poor flowability and low processing efficiency induced by high viscosity impede its further industrial applications. In this study, PEG-substituted tertiary amines were adapted to functionalize alginate with different molecular weight via acid-base reaction to improve the flowability. Based on alginate with low molecular weight, alginate fluids exhibited excellent flowability at room temperature in the absence of solvent...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28821081/direct-characterization-of-cotton-fabrics-treated-with-di-epoxide-by-nuclear-magnetic-resonance
#2
Min Xiao, Joronia Chéry, Ivan Keresztes, David B Zax, Margaret W Frey
A non-acid-based, di-functional epoxide, neopentyl glycol diglycidyl ether (NPGDGE), was used to modify cotton fabrics. Direct characterization of the modified cotton was conducted by Nuclear Magnetic Resonance (NMR) without grinding the fabric into a fine powder. NaOH and MgBr2 were compared in catalyzing the reaction between the epoxide groups of NPGDGE and the hydroxyl groups of cellulose. Possible reaction routes were discussed. Scanning electron microscopy (SEM) images showed that while the MgBr2-catalyzed reaction resulted in self-polymerization of NPGDGE, the NaOH-catalyzed reaction did not...
October 15, 2017: Carbohydrate Polymers
https://www.readbyqxmd.com/read/28820241/interactions-of-verkade-s-superbase-with-strong-lewis-acids-from-labile-mono-and-binuclear-lewis-acid-base-complexes-to-phosphenium-cations
#3
Suresh Mummadi, Dustin Kenefake, Rony Diaz, Daniel K Unruh, Clemens Krempner
A series of mono- and binuclear Lewis acid-base complexes of the formulas N[CH2CH2N(Pr(i))]3P→LA [LA = BH3 (8), Ga(C6F5)3 (10), GaCl3 (11)], LA←N[CH2CH2N(Pr(i))]3P [LA = Al(C6F5)3 (6a), AlMe3 (6b), AlEt3 (6c), AlBu(i)3 (6d), BF3 (13)], and LA←N[CH2CH2N(Pr(i))]3P→LA [Lewis acid (LA) = Al(C6F5)3 (7a), AlMe3 (7b), AlEt3 (7c), AlBu(i)3 (7d), AlCl3 (7e), BH3 (9)] were generated from reactions of Verkade's base, N[CH2CH2N(Pr(i))]3P (1), with various boron-, aluminum-, and gallium-containing Lewis acids, and characterized by multinuclear NMR spectroscopy...
August 18, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28820199/tuning-the-copper-ii-coordination-properties-of-cyclam-by-subtle-chemical-modifications
#4
Nathalie Camus, Nathalie Le Bris, Selbi Nuryyeva, Matthieu Chessé, David Esteban-Gómez, Carlos Platas-Iglesias, Raphaël Tripier, Mourad Elhabiri
The acid-base and copper(ii) coordination properties of three previously described cyclam derivatives are reported. Potentiometry, mass spectrometry, UV-vis absorption spectroscopy, electrochemistry and theoretical calculations were combined to investigate the protonation and binding properties of Bn-cyclam-EtOH (L1), oxo-cyclam-EtOH (L2) and oxo-Bn-cyclam-EtOH (L3). These three cyclams are C-functionalized by a hydroxyethyl pendant arm and display either one N-benzyl group and/or an amide replacing one macrocyclic secondary amine...
August 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28817670/synthesis-radiosynthesis-and-in-vitro-evaluation-of-18f-bodipy-c16-triglyceride-as-a-dual-modal-imaging-agent-for-brown-adipose-tissue
#5
Andreas Paulus, Marco Maenen, Natascha Drude, Emmani B M Nascimento, Wouter D van Marken Lichtenbelt, Felix M Mottaghy, Matthias Bauwens
BACKGROUND: Brown adipose tissue research is in the focus in the field of endocrinology. We designed a dual-modal fluorescent/PET fatty acid based tracer on commercially available Bodipy-C16, which can be synthesized to its corresponding triglyceride and which combines the benefits of fluorescent and PET imaging. METHODS: Bodipy-C16 was coupled to 1,3-diolein resulting in Bodipy-triglyceride. Bodipy-C16 and Bodipy-triglyceride compounds were radiolabeled with 18F using an 18F/19F exchange reaction to yield a dual-modal imaging molecule...
2017: PloS One
https://www.readbyqxmd.com/read/28816385/contrasting-physiological-responses-to-future-ocean-acidification-among-arctic-copepod-populations
#6
Peter Thor, Allison Bailey, Sam Dupont, Piero Calosi, Janne E Søreide, Pierre De Wit, Ella Guscelli, Lea Loubet-Sartrou, Ida Marie Deichmann, Martin M Candee, Camilla Svensen, Andrew L King, Richard G J Bellerby
Widespread ocean acidification (OA) is modifying the chemistry of the global ocean, and the Arctic is recognised as the region where the changes will progress at the fastest rate. Moreover, Arctic species show lower capacity for cellular homeostasis and acid-base regulation rendering them particularly vulnerable to OA. In the present study, we found physiological differences in OA response across geographically separated populations of the keystone Arctic copepod Calanus glacialis. In copepodite stage CIV, measured reaction norms of ingestion rate and metabolic rate showed severe reductions in ingestion and increased metabolic expenses in two populations from Svalbard (Kongsfjord and Billefjord) whereas no effects were observed in a population from the Disko Bay, West Greenland...
August 17, 2017: Global Change Biology
https://www.readbyqxmd.com/read/28815804/octadentate-picolinic-acid-based-bispidine-ligand-for-radiometal-ions
#7
Peter Comba, Una Jermilova, Chris Orvig, Brian O Patrick, Caterina F Ramogida, Katharina Rück, Christina Schneider, Miriam Starke
The synthesis of the octadentate bispidine ligand H2bispa2 bearing two picolinic acid pendant arms and its coordination chemistry with metal ions with radionuclides relevant for nuclear medicine, i.e. indium(III) (111In), lutetium(III) (177Lu) and lanthanum(III) (as surrogate for 225Ac), are reported. The non-radioactive metal complexes of the N6O2-type bispa ligand were characterized by 1H and 13C nuclear magnetic resonance spectroscopy, elemental analysis, mass spectrometry and single crystal X-ray analysis...
August 16, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28814497/extracellular-acid-base-balance-and-ion-transport-between-body-fluid-compartments
#8
REVIEW
Julian L Seifter, Hsin-Yun Chang
Clinical assessment of acid-base disorders depends on measurements made in the blood, part of the extracellular compartment. Yet much of the metabolic importance of these disorders concerns intracellular events. Intracellular and interstitial compartment acid-base balance is complex and heterogeneous. This review considers the determinants of the extracellular fluid pH related to the ion transport processes at the interface of cells and the interstitial fluid, and between epithelial cells lining the transcellular contents of the gastrointestinal and urinary tracts that open to the external environment...
September 2017: Physiology
https://www.readbyqxmd.com/read/28814306/blood-acid-base-status-in-impala-aepyceros-melampus-immobilised-and-maintained-under-total-intravenous-anaesthesia-using-two-different-drug-protocols
#9
Gareth E Zeiler, Leith C R Meyer
BACKGROUND: In mammals, homeostasis and survival are dependent on effective trans-membrane movement of ions and enzyme function, which are labile to extreme acid-base changes, but operate efficiently within a narrow regulated pH range. Research in patients demonstrating a pH shifts outside the narrow regulated range decreased the cardiac output and systemic vascular resistance and altered the oxygen binding to haemoglobin. These cardiopulmonary observations may be applicable to the risks associated with anaesthesia and performance of wildlife ungulates on game farms...
August 16, 2017: BMC Veterinary Research
https://www.readbyqxmd.com/read/28814113/intracytoplasmic-sperm-injection-using-hyaluronic-acid-or-polyvinylpyrrolidone-a-time-lapse-sibling-oocyte-study
#10
Yanhe Liu, Katie Feenan, Vincent Chapple, Peter Roberts, Phillip Matson
This study evaluated the effect of sperm selection and intracytoplasmic sperm injection (ICSI) on subsequent fertilization and embryo development using the hyaluronic acid-based SpermSlow™ (HA-ICSI) compared to injection with polyvinylpyrrolidone (PVP-ICSI). A total of 206 metaphase II oocytes were collected from 21 prospectively enrolled ICSI cycles at Fertility North between July 2014 and March 2015. Sibling oocytes were randomized into HA-ICSI and PVP-ICSI (n = 103 per group). Subsequent fertilization outcomes and embryo development in terms of qualitative and quantitative time-lapse measures following three-day culture in the Embryoscope™ were compared...
August 17, 2017: Human Fertility: Journal of the British Fertility Society
https://www.readbyqxmd.com/read/28812999/synthesis-and-evaluation-of-a-sodium-alginate-4-aminosalicylic-acid-based-microporous-hydrogel-for-potential-viscosupplementation-for-joint-injuries-and-arthritis-induced-conditions
#11
Dharmesh R Chejara, Mostafa Mabrouk, Pradeep Kumar, Yahya E Choonara, Pierre P D Kondiah, Ravindra V Badhe, Lisa C du Toit, Divya Bijukumar, Viness Pillay
A microporous hydrogel was developed using sodium alginate (alg) and 4-aminosalicylic acid (4-ASA). The synthesized hydrogel was characterized using various analytical techniques such as Fourier transform infrared spectroscopy (FTIR), Carbon-13 nuclear magnetic resonance ((13)C-NMR), X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and differential scanning calorimetry (DSC). Additonal carboxyl and hydroxyl functional groups of 4-ASA provided significant lubrication and stress-triggered sol-gel transition to the conjugated hydrogel...
August 16, 2017: Marine Drugs
https://www.readbyqxmd.com/read/28812893/%C3%AE-sulfinyl-benzoates-as-precursors-to-li-and-mg-carbenoids-for-the-stereoselective-iterative-homologation-of-boronic-esters
#12
Giorgia Casoni, Murat Kucukdisli, James M Fordham, Matthew Burns, Eddie L Myers, Varinder K Aggarwal
The stereoselective reagent-controlled homologation of boronic esters is one of a small number of iteratable synthetic transformations that if automated could form the basis of a veritable molecule-making machine. Recently, α-stannyl triisopropylbenzoates and α-sulfinyl chlorides have emerged as useful building blocks for the iterative homologation of boronic esters. However, α-stannyl benzoates need to be prepared using stoichiometric amounts of the (+)- or (-)-enantiomer of the scarcely available and expensive diamine sparteine; also, these building blocks, together with the byproducts that are generated during homologation, are perceived as being toxic...
August 16, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28812879/germanium-and-tin-monoxides-trapped-by-oxophilic-germylene-and-stannylene-ligands
#13
Yunxia Gao, Ying Yang, Wenjun Zheng, Yuanyuan Su, Xiang Zhang, Herbert W Roesky
Germanium and tin monoxides (MO, M = Ge, Sn) were trapped by the 1,2,4-diazaphospholide-based germylene and stannylene M[3,5-tBu2dp]2 (M = Ge (2), Sn (3)), resulting in the Lewis acid-base adduct of composition M(μ-O)[M{η(1)(N)-(3,5-tBu2dp)}2]2 (M = Ge (4), Sn (5)). Compounds 4 and 5 were characterized by single-crystal X-ray structural analysis. The bonding features of 4 and 5 were supported by DFT calculations.
August 16, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28812327/design-and-synthesis-of-terephthalic-acid-based-histone-deacetylase-inhibitors-with-dual-stage-anti-plasmodium-activity
#14
Katharina Stenzel, Ming Jang Chua, Sandra Duffy, Yevgeniya Antonova-Koch, Stephan Meister, Alexandra Hamacher, Matthias U Kassack, Elizabeth A Winzeler, Vicky M Avery, Thomas Kurz, Katherine T Andrews, Finn Kristian Hansen
In this work we aimed to develop parasite-selective HDAC inhibitors with activity against the disease-causing asexual blood stages of Plasmodium as well as causal prophylactic and/or transmission blocking properties. We report the design, synthesis and biological testing of a series of 13 terephthalic acid-based histone deacetylase inhibitors. All compounds showed low cytotoxicity against human embryonic kidney (HEK293) cells (IC50 8 - >51 µM), with 11 also having sub-micromolar in vitro activity against drug-sensitive (3D7) and multi-drug resistant (Dd2) asexual blood stage Plasmodium falciparum parasites (IC50 ~ 0...
August 15, 2017: ChemMedChem
https://www.readbyqxmd.com/read/28812080/computational-design-of-ph-switchable-control-agents-for-nitroxide-mediated-polymerization
#15
Ganna Gryn'ova, Leesa M Smith, Michelle L Coote
In the present work we use accurate quantum chemistry to evaluate several known and novel nitroxides bearing acid-base groups as pH-switchable control agents for room temperature NMP. Based on G3(MP2,CC)(+)//M06-2X/6-31+G(d) calculations with UAKS-CPCM/M06-2X/6-31+G(d) solvation corrections, a number of novel nitroxides are predicted to be suitable for controlled polymerization of bulk styrene at room temperature when deprotonated (i.e. negatively charged), while remaining inert when neutral. These include an α-ethyl analogue of 3-carboxy-PROXYL and novel derivatives of 2,2,5-trimethyl-4-phenyl-3-azahexane-3-nitroxide (TIPNO) that have been modified to include acidic groups...
August 16, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28809506/stereospecific-palladium-catalyzed-c-h-arylation-of-pyroglutamic-acid-derivatives-at-the-c3-position-enabled-by-8-aminoquinoline-as-a-directing-group
#16
Oscar Verho, Micah Maetani, Bruno Melillo, Jochen Zoller, Stuart L Schreiber
An efficient and stereospecific Pd-catalyzed protocol for the C-H arylation of pyroglutamic acid derivatives that uses 8-aminoquinoline as a directing group is described. The reaction was shown to proceed efficiently with a variety of aryl and heteroaryl iodides bearing different functional groups, giving C3-arylated cis products in good to high yields. Removal of the 8-aminoquinoline unit from these C-H arylation products enables access to synthetically useful cis and trans pyroglutamic acid-based building blocks...
August 15, 2017: Organic Letters
https://www.readbyqxmd.com/read/28807216/early-resuscitation-with-exendin-4-alleviates-acute-lung-injury-after-hemorrhagic-shock-in-rats
#17
Xiang Song, Gan Chen, Xin Luo, Guoxing You, Yujing Yin, Ying Wang, Lian Zhao, Hong Zhou
BACKGROUND: Oxidative stress induced by hemorrhagic shock (HS) is known to initiate a systemic inflammatory response, which leads to subsequent acute lung injury. This study is aimed to assess the efficacy of exendin-4 (Ex-4) in attenuating lung injury in a rat model of HS and resuscitation (HS/R). METHODS: HS was induced in sodium pentobarbital-anesthetized adult male Wistar rats by withdrawing blood to maintain a mean arterial pressure of 30-35 mm Hg for 50 min...
August 2017: Journal of Surgical Research
https://www.readbyqxmd.com/read/28806699/a-portable-synthesis-of-water-soluble-carbon-dots-for-highly-sensitive-and-selective-detection-of-chlorogenic-acid-based-on-inner-filter-effect
#18
Huan Yang, Liu Yang, Yusheng Yuan, Shuang Pan, Jidong Yang, Jingjing Yan, Hui Zhang, Qianqian Sun, Xiaoli Hu
In this work, a simple and facile hydrothermal method for synthesis of water-soluble carbon dots (CDs) with malic acid and urea, and were then employed as a high-performance fluorescent probe for selective and sensitive determination of chlorogenic acid (CGA) based on inner filter effect. The as-synthesized CDs was systematically characterized by Transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), Energy disperse spectroscopy (EDS), UV-vis absorption spectroscopy, spectrofluorophotometry, and the results indicated that the sizes of CDs were mainly distributed in the range of 1...
August 1, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28806636/blood-or-not-blood-that-is-the-question-a-non-destructive-method-for-the-detection-of-blood-contaminated-fingermarks
#19
Alfonso Bentolila, Ira Hartman, Michal Levin-Elad
Working in crime scenes presents a challenge to the forensic scientist, as some surfaces, such as floors and walls, cannot be transferred to the lab for further development and must, therefore, be processed at the crime scene itself. Two main types of latent fingermarks may be encountered in crime scenes: amino acids based and blood contaminated. One of the most common reagents, which are able to develop both types of fingermarks on porous surfaces, is ninhydrin. As blood contaminated fingermarks may be crucial in connecting the suspect to the crime it is important to be able to distinguish between them and natural fingermarks...
August 5, 2017: Forensic Science International
https://www.readbyqxmd.com/read/28805867/coumarin-containing-thermoresponsive-hyaluronic-acid-based-nanogels-as-delivery-systems-for-anticancer-chemotherapy
#20
Talitha F Stefanello, Benoit Couturaud, Anna Szarpak-Jankowska, David Fournier, Benoit Louage, Francielle P Garcia, Celso V Nakamura, Bruno G De Geest, Patrice Woisel, Boudewijn van der Sanden, Rachel Auzély-Velty
Multi-stimuli responsive nanogels based on biocompatible hydrophilic polymers have emerged as promising drug delivery systems to improve anticancer therapy with hydrophobic drugs, through increase of circulating-time in the bloodstream, tumor-targeting and reduction of systemic toxicity. This paper reports on the synthesis, characterization and biological perspectives of light- and thermoresponsive hyaluronic acid (HA)-based nanogels containing coumarin as the photocleavable group. Newly synthesized nanogels exhibited interesting features: formation by a temperature-triggered self-assembly process, successful incorporation of poorly water-soluble molecules, light-responsiveness as demonstrated by a significant shift in the critical aggregation temperature after light irradiation, efficient internalization by cancer cells overexpressing the CD44 receptor of HA, ability to circulate for a prolonged period of time in the bloodstream after intravenous injection in mice and considerable detection in tumor tissues...
August 14, 2017: Nanoscale
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