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https://www.readbyqxmd.com/read/28532114/hypocrellin-b-and-nano-silver-loaded-polymeric-nanoparticles-enhanced-generation-of-singlet-oxygen-for-improved-photodynamic-therapy
#1
Subramanian Natesan, Venkateshwaran Krishnaswami, Chandrasekar Ponnusamy, Madi Madiyalakan, Thomas Woo, Rajaguru Palanisamy
A nanoparticulate photodynamic approach was employed with an objective to achieve enhanced production of singlet oxygen ((1)O2), for the management of posterior segment eye diseases like age related macular degeneration. The hypocrellin B (HB) loaded poly lactide-co-glycolide nanoparticle formulations were incorporated with nano silver (HBS-NPs). The optimized HBS-NPs contained 2.60±0.06mg/mL of HB and showed (i) 135.6 to 828.2nm size range, and (ii) negative zeta potential with a narrow polydispersity index...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531356/spin-polarization-transfer-from-a-photogenerated-radical-ion-pair-to-a-stable-radical-controlled-by-charge-recombination
#2
Noah E Horwitz, Brian T Phelan, Jordan N Nelson, Catherine M Mauck, Matthew D Krzyaniak, Michael R Wasielewski
Photoexcitation of electron donor-acceptor molecules frequently produces radical ion pairs with well-defined initial spin-polarized states that have attracted significant interest for spintronics. Transfer of this initial spin polarization to a stable radical is predicted to depend on the rates of the radical ion pair recombination reactions, but this prediction has not been tested experimentally. In this study, a stable radical/electron donor/chromophore/electron acceptor molecule, BDPA(•)-mPD-ANI-NDI, where BDPA(•) is α,γ-bisdiphenylene-β-phenylallyl, mPD is m-phenylenediamine, ANI is 4-aminonaphthalene-1,8-dicarboximide, and NDI is naphthalene-1,4:5,8-bis(dicarboximide), was synthesized...
May 22, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28530763/surface-oxygen-vacancy-induced-solar-light-activity-enhancement-of-a-cdwo4-bi2o2co3-core-shell-heterostructure-photocatalyst
#3
Chunming Yang, Guimei Gao, Junjun Zhang, Ruiping Liu, Ruicheng Fan, Ming Zhao, Yongwang Wang, Shucai Gan
A CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst was fabricated via a facile two-step hydrothermal process. Flower-like Bi2O2CO3 was synthesized and functioned as the cores on which CdWO4 nanorods were coated as the shells. Photoluminescence (PL) spectra and electron paramagnetic resonance (EPR) demonstrate that the CdWO4/Bi2O2CO3 core-shell heterostructure photocatalyst possesses a large amount of oxygen vacancies, which induce defect levels in the band gap and help to broaden light absorption. The photocatalyst exhibits enhanced photocatalytic activity for Rhodamine B (RhB), methylene blue (MB), methyl orange (MO), and colorless contaminant phenol degradation under solar light irradiation...
May 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28530402/spin-crossover-in-double-salts-containing-six-and-four-coordinate-cobalt-ii-ions
#4
Joanna Palion-Gazda, Barbara Machura, Rafal Kruszynski, Thais Grancha, Nicolás Moliner, Francesc Lloret, Miguel Julve
The preparation and spectroscopic and structural characterization of three cobalt(II) complexes of formulas [Co(tppz)2](dca)2 (1), [Co(tppz)2][Co(NCS)4]·MeOH (2), and [Co(tppz)2][Co(NCO)4]·2H2O (3) [tppz = 2,3,5,6-tetrakis(2-pyridyl)pyrazine and dca = dicyanamide] are reported here. Compounds 1-3 have in common the presence of the cationic [Co(tppz)2](2+) entity where each mer-tridentate tppz ligand coordinates to the cobalt(II) ion equatorially through two pyridyl donors and axially via the pyrazine, completing the six-coordination...
May 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28528851/microstructure-evaluation-of-dermally-applicable-liquid-crystals-as-a-function-of-water-content-and-temperature-can-electron-paramagnetic-resonance-provide-complementary-data
#5
Mirjam Gosenca Matjaž, Janez Mravljak, Marija Bešter Rogač, Marjeta Šentjurc, Mirjana Gašperlin, Alenka Zvonar Pobirk
Insight into the microstructure of lyotropic liquid crystals (LCs) is of crucial importance for development of novel dermal delivery systems. Our aim was to evaluate the phase behaviour of dermally applicable LCs composed of isopropyl myristate/Tween 80/lecithin/water, along the dilution line, where phase transitions are predominantly driven by increased water content. Additionally, identification of LC temperature dependence is of great importance for skin application. Selected LCs were evaluated using electron paramagnetic resonance (EPR) plus conventionally used methods of polarization microscopy, small-angle X-ray scattering, differential scanning calorimetry, and rheological measurements...
May 18, 2017: International Journal of Pharmaceutics
https://www.readbyqxmd.com/read/28528285/comparison-of-the-pharmacological-and-biological-properties-of-hpma-copolymer-pirarubicin-conjugates-a-single-chain-copolymer-conjugate-and-its-biodegradable-tandem-diblock-copolymer-conjugate
#6
Tomas Etrych, Kenji Tsukigawa, Hideaki Nakamura, Petr Chytil, Jun Fang, Karel Ulbrich, Masaki Otagiri, Hiroshi Maeda
In this study, we compared the enhanced permeability and retention (EPR) effect, toxicity, and therapeutic effect of the conjugate of the linear polymer poly(N-(2-hydroxypropyl)methacrylamide) (HPMA) with pirarubicin with an Mw below the renal threshold (39g/mol) (named LINEAR) and the disulfide-linked tandem-polymeric dimer of the poly(HPMA)-pirarubicin conjugate with an Mw above the renal threshold (93g/mol) (named DIBLOCK). The DIBLOCK conjugate, which was susceptible to reductive degradation, showed both a better EPR effect (tumor delivery) (2...
May 17, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/28527736/the-effects-of-non-invasive-radiofrequency-electric-field-hyperthermia-on-biotransport-and-biodistribution-of-fluorescent-60-fullerene-derivative-in-a-murine-orthotopic-model-of-breast-adenocarcinoma
#7
Norman A Lapin, Martyna Krzykawska-Serda, Sean Dilliard, Yuri Mackeyev, Maciej Serda, Lon J Wilson, Steven A Curley, Stuart J Corr
The aim of this study is to understand the combined and differential biokinetic effects of radiofrequency (RF) electric-field hyperthermia as an adjunctive therapy to [60]fullerene nanoparticle-based drug delivery systems in targeting the micro-vasculature and micro-environments of breast cancer tumors. Intravital microscopy (IVM) is an ideal tool to provide the spatial and temporal resolution needed for quantification in this investigation. The water-soluble and fluorescent [60]fullerene derivative (C60-serPF) was designed to be an amphiphilic nanostructure, which is able to cross several biological membranes and accumulate in tumor tissues by passing through abnormally leaky tumor blood vessels...
May 17, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28525272/direct-synthesis-of-an-unprecedented-stable-radical-of-nickel-ii-3-5-bis-dimedonyl-azadiisoindomethene-with-strong-and-narrow-near-infrared-absorption-at-%C3%AE-%C3%A2-1000-nm
#8
Elena A Makarova, Yuriy V Zatsikha, Kelly M E Newman, Vinod K Paidi, Valeria A Beletsky, Johan van Lierop, Evgeny A Lukyanets, Victor N Nemykin
An unprecedented stable neutral radical nickel(II) complex of 3,5-bis(dimedonyl)azadiisoindomethene (1) was prepared by the direct reaction between 1,3-diiminoisoindoline and dimedone. A new radical complex 1 has an intense and narrow absorption at 1008 nm and can be reduced to a less stable anionic [1](-) with a typical aza(dibenzo)boron dipyrromethene (aza-BODIPY) UV-vis spectrum. Complex 1, along with two other colored condensation reaction products 2 and 3, was characterized by spectroscopy and X-ray crystallography, while the paramagnetic nature of 1 was probed by EPR and SQUID methods...
May 19, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28525271/electron-spin-relaxation-and-biochemical-characterization-of-the-hydrogenase-maturase-hydf-insights-into-2fe-2s-and-4fe-4s-cluster-communication-and-hydrogenase-activation
#9
Eric M Shepard, Amanda S Byer, Priyanka Aggarwal, Jeremiah N Betz, Anna G Scott, Krista Shisler, Robert J Usselman, Gareth R Eaton, Sandra S Eaton, Joan B Broderick
Nature utilizes [FeFe]-hydrogenase enzymes to catalyze the interconversion between H2 and protons and electrons. Catalysis occurs at the H-cluster, a carbon monoxide, cyanide, and dithiomethylamine-coordinated 2Fe subcluster bridged via a cysteine to a [4Fe-4S] cluster. Biosynthesis of this unique metallocofactor is accomplished by three maturase enzymes denoted HydE, HydF, and HydG. HydE and HydG belong to the radical S-adenosylmethionine superfamily of enzymes and synthesize the nonprotein ligands of the H-cluster...
May 19, 2017: Biochemistry
https://www.readbyqxmd.com/read/28522191/enhanced-tumor-therapy-via-drug-co-delivery-and-in-situ-vascular-promoting-strategy
#10
Mingxing Yin, Songwei Tan, Yuling Bao, Zhiping Zhang
Conventional tumor starving therapy by reducing its vessel density may be effective at early treatment but potentially contributes to tumor hypoxia, drug resistance and metastasis. A new strategy through enhancing tumor angiogenesis in combination with effective chemotherapeutic drugs, has shown successful tumor growth and spread inhibition. To achieve in situ release of angiogenic and antitumor drugs in tumor, we designed a precise ratiometric polymeric hybrid micelle system for co-delivering nitric oxide and paclitaxel...
May 15, 2017: Journal of Controlled Release: Official Journal of the Controlled Release Society
https://www.readbyqxmd.com/read/28522117/characterization-of-cu-ii-reconstituted-acc-oxidase-using-experimental-and-theoretical-approaches
#11
Nadia El Bakkali-Tahéri, Sybille Tachon, Maylis Orio, Sylvain Bertaina, Marlène Martinho, Viviane Robert, Marius Réglier, Thierry Tron, Pierre Dorlet, A Jalila Simaan
1-Aminocyclopropane-1-carboxylic acid oxidase (ACCO) is a non heme iron(II) containing enzyme that catalyzes the final step of the ethylene biosynthesis in plants. The iron(II) ion is bound in a facial triad composed of two histidines and one aspartate (H177, D179 and H234). Several active site variants were generated to provide alternate binding motifs and the enzymes were reconstituted with copper(II). Continuous wave (cw) and pulsed Electron Paramagnetic Resonance (EPR) spectroscopies as well as Density Functional Theory (DFT) calculations were performed and models for the copper(II) binding sites were deduced...
May 15, 2017: Archives of Biochemistry and Biophysics
https://www.readbyqxmd.com/read/28520412/identification-of-the-ferredoxin-binding-site-of-a-ferredoxin-dependent-cyanobacterial-nitrate-reductase
#12
Anurag P Srivastava, Emily P Hardy, James P Allen, Brian J Vaccaro, Michael K Johnson, David B Knaff
An in silico model for the 1:1 ferredoxin (Fd)/nitrate reductase (NR) complex, using the known structure of Synechocystis sp. PCC 6803 Fd and the in silico model of Synechococcus sp. PCC 7942 NR, is used to map the interaction sites that define the interface between Fd and NR. To test the electrostatic interactions predicted by the model complex, five positively charged NR amino acids Arg43, Arg46, Arg197, Lys201 and Lys614; and a negatively charged amino acid, Glu219, were altered using site-directed mutagenesis and characterized by activity measurements, metal analysis and EPR studies...
May 18, 2017: Biochemistry
https://www.readbyqxmd.com/read/28520398/multiple-states-of-nitrile-hydratase-from-rhodococcus-equi-tg328-2-structural-and-mechanistic-insights-from-epr-and-dft-studies
#13
Natalia Stein, Natalie Gumataotao, Natalia Hajnas, Rui Wu, K P Wasantha Lankathilaka, Uwe T Bornscheuer, Dali Liu, Adam T Fiedler, Richard C Holz, Brian Bennett
Iron-type nitrile hydratases (NHases) contain an Fe(III) ion coordinated in a characteristic "claw setting" by an axial cysteine thiolate; two equatorial peptide nitrogens; the sulfur atoms of equatorial cysteine-sulfenic and cysteine-sulfinic acids, respectively; and an axial water/hydroxyl moiety. The cysteine-sulfenic acid is susceptible to oxidation and the enzyme is traditionally prepared using butyric acid as an oxidative protectant. The as-prepared enzyme exhibits a complex EPR spectrum due to multiple low-spin (S = 1/2) Fe(III) species...
May 18, 2017: Biochemistry
https://www.readbyqxmd.com/read/28517006/synthesis-and-characterization-of-a-family-of-thioether-dithiolate-bridged-heteronuclear-iron-complexes
#14
Yahui Zhang, Dawei Yang, Ying Li, Baomin Wang, Xiangyu Zhao, Jingping Qu
The thioether-dithiolate-bridged heterotrinuclear complexes [Cp*Fe(μ-1k(3)SSS':2k(2)SS-tpdt)M(μ-2k(2)SS:3k(3)SSS'-tpdt)FeCp*][PF6]2 (Cp* = η(5)-C5Me5; tpdt = S(CH2CH2S)2; 2, M = Co; 3, M = Ni; 4, M = Pd) have been prepared by a reaction of [Cp*Fe(η(3)-tpdt)] (1) with complexes CoCl2, NiCl2(PPh3)2, and PdCl2(PPh3)2, respectively. Similarly, treatment of complex 1 with CuCl(PPh3) or AgPF6 afforded two heterotrinuclear complexes, [Cp*Fe(μ-1k(3)SSS':2k(2)SS-tpdt)M(μ-2k(2)SS:3k(3)SSS'-tpdt)FeCp*][PF6] (5, M = Cu; 6, M = Ag), while reaction of 1 with the complex AuCl(PPh3) gave a heterobinuclear complex, [Cp*Fe(μ-1k(3)SSS':2k(1)S-tpdt)Au(PPh3)][PF6] (7)...
May 18, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28515622/the-influence-of-genistein-on-free-radicals-in-normal-dermal-fibroblasts-and-keloid-fibroblasts-examined-by-epr-spectroscopy
#15
Magdalena Jurzak, Paweł Ramos, Barbara Pilawa
Normal and keloid fibroblasts were examined using X-band (9.3 GHz) electron paramagnetic resonance spectroscopy. The effect of genistein on the concentration of free radicals in both normal dermal and keloid fibroblasts after ultraviolet irradiation was investigated. The highest concentration of free radicals was seen in keloid fibroblasts, with normal fibroblasts containing a lower concentration. The concentration of free radicals in both normal and keloid fibroblasts was altered in a concentration-dependent manner by the presence of genistein...
2017: Medicinal Chemistry Research
https://www.readbyqxmd.com/read/28514836/oxidation-of-organic-contaminant-in-a-self-driven-electro-natural-maghemite-peroxydisulfate-system-efficiency-and-mechanism
#16
Suding Yan, Weihui Xiong, Shuya Xing, Yueqi Shao, Rui Guo, Hui Zhang
Electro-assisted iron-mediated persulfate (PS) activation process has been successfully employed to oxidize organic contaminant. However, a majority of iron-based catalysts used for PS activation was synthesized through complicated or demanding procedures and may have potential risks on environment during the preparation process. Herein, natural maghemite (NM) which is abundant on the earth was employed to activate peroxydisulfate (PDS) in an electrolytic cell. The voltage was provided by microbial fuel cell (MFC) instead of external power as reported in the previous studies, so as to establish a self-driven electro/natural maghemite/PDS system (MFC/NM/PDS) for the oxidation of acid orange 7 (AO7)...
May 12, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28514348/-dynamics-of-immunological-features-of-oral-liquid-in-children-with-chronic-catarrhal-gingivitis-living-on-polluted-territories-with-fluoride-and-iodine-deficiency
#17
N V Malko, E V Besvushko
The aim of the study was to assess the state of oral liquid (OL) immunity in children with chronic catarrhal gingivitis (CCG) living in adverse environmental conditions. 120 children aged 7-15 residing in ecologically unfavorable areas of Lviv region were examined, while 75 children living in 'relatively clean' region were involved in the control group. Chronic catarrhal gingivitis was diagnosed according to Danilevskiy classification (1994). The level of cytokines in oral liquid of 7-years-old children living in ecologically polluted region (EPR), was (198...
2017: Stomatologii︠a︡
https://www.readbyqxmd.com/read/28513747/structural-and-electronic-elucidation-of-a-n-heterocyclic-silylene-vanadocene-adduct
#18
Mikko M Hänninen, Amgalanbaatar Baldansuren, Thomas Pugh
The solid and solution state structure of the vanadium(ii) N-heterocyclic silylene (NHSi) complex, [((Si)IPr)V(Cp)2] (1) is reported ((Si)IPr: 1,3-bis(2,6-diisopropylphenyl)-1,3-diaza-2-silacyclopent-4-en-2-ylidene). The electronic structure of 1 is probed using a combination of magnetic measurements, EPR spectroscopy and computational studies. The V-Si bond strength and complex forming mechanism between vanadocene and an NHSi ligand is elucidated using computational methods.
May 17, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28513732/reduced-001-tio2-x-photocatalysts-noble-metal-free-co2-photoreduction-for-selective-ch4-evolution
#19
Wenzhang Fang, Lhoussain Khrouz, Yi Zhou, Bin Shen, Chunyang Dong, Mingyang Xing, Shashank Mishra, Stéphane Daniele, Jinlong Zhang
The preparation of reduced TiO2 photocatalysts with high Ti(3+) concentration is a great challenge due to their instability in air. Here we report a new approach for the synthesis of reduced TiO2 with {001} facets exposed via a hydrothermal process. By the introduction of fluoride atoms, {001} and {101} facets are formed, which act as hole and electron collectors, respectively, for charge separation. By adjusting the volume of HF added, a rutile-anatase transition is observed for the first time. EPR spectra confirm the generation of Ti(3+) species in the bulk of TiO2, and Ti(3+) signals are studied in the anatase and rutile phases separately...
May 17, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28511010/%C3%AF-extended-and-curved-anti-aromatic-polycyclic-hydrocarbons
#20
Junzhi Liu, Ji Ma, Ke Zhang, Prince Ravat, Peter Machata, Stanislav M Avdoshenko, Felix Hennersdorf, Hartmut Komber, Wojciech Pisula, Jan J Weigand, Alexey A Popov, Reinhard Berger, Klaus Müllen, Xinliang Feng
Synthesis of anti-aromatic polycyclic hydrocarbons (PHs) is challenging because the high energy of their highest occupied molecular orbital (HOMO) and low energy of their lowest unoccupied molecular orbital (LUMO) cause them to be reactive and unstable. In this work, two large anti-aromatic acene analogues, namely cyclopenta[pqr]indeno[2,1,7-ijk]tetraphene (CIT, 1a) and cyclopenta[pqr]indeno[7,1,2-cde]picene (CIP, 1b), as well as a curved anti-aromatic molecule with 48 π-electrons, dibenzo[a,c]diindeno[7,1,2-fgh:7',1',2'-mno]phenanthro[9,10-k]tetraphene (DPT, 1c), are synthesized based on the corona of indeno[1,2-b]fluorene...
May 16, 2017: Journal of the American Chemical Society
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