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https://www.readbyqxmd.com/read/27925861/modeling-heavy-ion-impairment-of-hippocampal-neurogenesis-after-acute-and-fractionated-irradiation
#1
Eliedonna Cacao, Francis A Cucinotta
Radiation-induced impairment of neurogenesis in the hippocampal dentate gyrus is a concern due to its reported association with cognitive detriments after radiotherapy for brain cancers and the possible risks to astronauts chronically exposed to space radiation. Here, we have extended our recent work in a mouse model of impaired neurogenesis after exposure to low-linear energy transfer (LET) heavy ion radiation. To our knowledge, this is the first report of a predictive mathematical model of radiation-induced changes to neurogenesis for a variety of radiation types after acute or fractionated irradiation...
December 7, 2016: Radiation Research
https://www.readbyqxmd.com/read/27922181/evaluation-of-gas-and-carbon-transport-in-a-methanogenic-bioelectrochemical-system-bes
#2
Christy M Dykstra, Spyros G Pavlostathis
Bioelectrochemical systems (BESs) may be used to upgrade anaerobic digester biogas by directly converting CO2 to CH4 .The objective of this study was to evaluate gas (N2 , CO2 , CH4 , and H2 ) and carbon transport within a methanogenic BES. Four BES configurations were evaluated: abiotic anode with abiotic cathode (AAn-ACa), bioanode with abiotic cathode (BAn-ACa), abiotic anode with biocathode (AAn-BCa), and bioanode with biocathode (BAn-BCa). Transport of N2 , a gas commonly used for flushing anoxic systems, out of the anode headspace ranged from 3...
December 6, 2016: Biotechnology and Bioengineering
https://www.readbyqxmd.com/read/27919815/chemical-modification-of-functionalized-polyhydroxyalkanoates-via-click-chemistry-a-proof-of-concept
#3
Samuel Nkrumah-Agyeefi, Carmen Scholz
A novel approach to the post-biosynthetic chemical modification of bromo and alkyne functionalized poly(3-hydroxyalkanoates), (PHAs), via copper-catalyzed azide-alkyne cycloaddition (CuAAC) and strain promoted azide alkyne cycloaddition (SPAAC) is reported. Optimum conditions for the biosynthesis of the PHA copolymers, poly(3-hydroxynonanoate-co-3-hydroxy-11-bromoundecanoate) (PHNUBr) and poly(3-hydroxynonanoate-co-3-hydroxy-10-undecynoate) (PHNUD), using Pseudomonas oleovorans as cell factories were 20h of fermentation time and a total carbon substrate concentration of 40mM...
December 2, 2016: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/27918439/phenols-and-polyphenols-as-carbonic-anhydrase-inhibitors
#4
REVIEW
Anastasia Karioti, Fabrizio Carta, Claudiu T Supuran
Phenols are among the largest and most widely distributed groups of secondary metabolites within the plant kingdom. They are implicated in multiple and essential physiological functions. In humans they play an important role as microconstituents of the daily diet, their consumption being considered healthy. The physical and chemical properties of phenolic compounds make these molecules versatile ligands, capable of interacting with a wide range of targets, such as the Carbonic Anhydrases (CAs, EC 4.2.1.1). CAs reversibly catalyze the fundamental reaction of CO₂ hydration to bicarbonate and protons in all living organisms, being actively involved in the regulation of a plethora of patho/physiological processes...
December 2, 2016: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/27911139/volumetric-response-of-intracranial-meningioma-after-photon-or-particle-irradiation
#5
Petra Mozes, Jan Oliver Dittmar, Daniel Habermehl, Eric Tonndorf-Martini, Katalin Hideghety, Anne Dittmar, Jürgen Debus, Stephanie E Combs
BACKGROUND: Meningiomas are usually slow growing, well circumscribed intracranial tumors. In symptom-free cases observation with close follow-up imaging could be performed. Symptomatic meningiomas could be surgically removed and/or treated with radiotherapy. The study aimed to evaluate the volumetric response of intracranial meningiomas at different time points after photon, proton, and a mixed photon and carbon ion boost irradiation. PATIENTS AND METHODS: In Group A 38 patients received proton therapy (median dose: 56 GyE in 1...
December 2, 2016: Acta Oncologica
https://www.readbyqxmd.com/read/27910515/proton-pinhole-imaging-on-the-national-ignition-facility
#6
A B Zylstra, H-S Park, J S Ross, F Fiuza, J A Frenje, D P Higginson, C Huntington, C K Li, R D Petrasso, B Pollock, B Remington, H G Rinderknecht, D Ryutov, F H Séguin, D Turnbull, S C Wilks
Pinhole imaging of large (mm scale) carbon-deuterium (CD) plasmas by proton self-emission has been used for the first time to study the microphysics of shock formation, which is of astrophysical relevance. The 3 MeV deuterium-deuterium (DD) fusion proton self-emission from these plasmas is imaged using a novel pinhole imaging system, with up to five different 1 mm diameter pinholes positioned 25 cm from target-chamber center. CR39 is used as the detector medium, positioned at 100 cm distance from the pinhole for a magnification of 4 ×...
November 2016: Review of Scientific Instruments
https://www.readbyqxmd.com/read/27908621/radiotherapy-with-curative-intent-in-patients-with-early-stage-medically-inoperable-non-small-cell-lung-cancer-a-systematic-review
#7
REVIEW
Conrad B Falkson, Emily T Vella, Edward Yu, Medhat El-Mallah, Robert Mackenzie, Peter M Ellis, Yee C Ung
Patients with early-stage non-small-cell lung cancer (NSCLC) who are unable to undergo surgery can be offered radiation therapy (RT). Previously, conventional RT was offered; however, newer techniques such as stereotactic body RT (SBRT) have become available. The objective of the present systematic review was to investigate the effectiveness of RT with curative intent in patients with early-stage medically inoperable NSCLC. MEDLINE, EMBASE, and the Cochrane Library were searched for studies comparing stereotactic RT with curative intent compared with observation or other types of RT for early-stage, medically inoperable, NSCLC...
October 27, 2016: Clinical Lung Cancer
https://www.readbyqxmd.com/read/27908242/participation-of-two-carbonic-anhydrases-of-the-alpha-family-in-photosynthetic-reactions-in-arabidopsis-thaliana
#8
E M Zhurikova, L K Ignatova, N N Rudenko, V A Mudrik, D V Vetoshkina, B N Ivanov
The expression of genes of two carbonic anhydrases (CA) belonging to the α-family, α-CA2 and α-CA4 (according to the nomenclature in N. Fabre et al. (2007) Plant Cell Environ., 30, 617-629), was studied in arabidopsis (Arabidopsis thaliana, var. Columbia) leaves. The expression of the At2g28210 gene coding α-CA2 decreased under increase in plant illumination, while the expression of the At4g20990 gene coding α-CA4 increased. Under conditions close to optimal for photosynthesis, in plants with gene At2g28210 knockout, the effective quantum yield of photosystem 2 and the light-induced accumulation of hydrogen peroxide in leaves were lower than in wild type plants, while the coefficient of non-photochemical quenching of leaf chlorophyll a fluorescence and the rate of CO2 assimilation in leaves were higher...
October 2016: Biochemistry. Biokhimii︠a︡
https://www.readbyqxmd.com/read/27908146/energy-deposition-clustering-as-a-functional-radiation-quality-descriptor-for-modeling-relative-biological-effectiveness
#9
Fernanda Villegas, Gloria Bäckström, Nina Tilly, Anders Ahnesjö
PURPOSE: To explore the use of the frequency of the energy deposition (ED) clusters of different sizes (cluster order, CO) as a surrogate (instead of, e.g., LET) classification of the physical characteristics of ionizing radiation at a nanometer scale, to construct a framework for the calculation of relative biological effectiveness (RBE) with cell survival as endpoint. METHODS: The frequency of cluster order fCO is calculated by sorting the ED sites generated with the Monte Carlo track structure code LIonTrack into clusters based on a single parameter called the cluster distance dC being the maximum allowed distance between two neighboring EDs belonging to a cluster...
December 2016: Medical Physics
https://www.readbyqxmd.com/read/27905606/a-qm-mm-study-of-the-reaction-mechanism-of-human-%C3%AE-ketoacyl-reductase
#10
Fabiola E Medina, Rui P P Neves, Maria J Ramos, Pedro A Fernandes
Human fatty acid synthase (hFAS) is a multifunctional enzyme involved in a wide diversity of biological functions. For instance, it is a precursor of phospholipids and other complex processes such as the de novo synthesis of long chain fatty acid. Human FAS is also a component of biological membranes and it is implicated in the overexpression of several types of cancers. In this work, we describe the catalytic mechanism of β-ketoreductase (KR), which is a catalytic domain of the hFAS enzyme that catalyzes the reduction of β-ketoacyl to β-hydroxyacyl with the concomitant oxidation of the NADPH cofactor...
December 1, 2016: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/27895933/influence-of-proton-pump-inhibitors-and-histamine-h2-receptor-antagonists-on-serum-phosphorus-level-control-by-calcium-carbonate-in-patients-undergoing-hemodialysis-a-retrospective-medical-chart-review
#11
Masaomi Tatsuzawa, Ryuichi Ogawa, Atsushi Ohkubo, Kazuyo Shimojima, Kunimi Maeda, Hirotoshi Echizen, Akihisa Miyazaki
BACKGROUND: Hyperphosphatemia is one of the common complications in patients undergoing hemodialysis. Although calcium carbonate (CaC) is often used to control serum inorganic phosphorus level in dialysis patients, co-administration of gastric acid reducers (ARs) may interfere with the phosphate binding effect of CaC. We performed a retrospective medical chart review to study whether ARs attenuate the hypophosphatemic effect of CaC in patients undergoing hemodialysis. METHODS: One hundred and eight chronic hemodialysis patients receiving either CaC alone or CaC concomitant with one of the ARs (proton pump inhibitors and histamine H2-receptor antagonists) were retrieved from the medical charts in Juntendo University Nerima Hospital...
2016: Journal of Pharmaceutical Health Care and Sciences
https://www.readbyqxmd.com/read/27894244/umbelliferone-decreases-intracellular-ph-and-sensitizes-melanoma-cell-line-a375-to-dacarbazin-comparison-with-acetazolamide
#12
Clémentine Puech, Morgane Chatard, Delphine Felder-Flesch, Nathalie Prevot, Nathalie Perek
The high degree of malignancy of tumour cells is linked to alterations of many physiological parameters like the intracellular pH (pHi). The pHi in cancer cell line is regulated by the anhydrase carbonique IX (CA IX). The main enzymatic function of the CA IX protein is to catalyze the hydration of carbon dioxide into bicarbonate ions and protons. Inhibiton of transmembrane tumor associated isozyme carbonic anhydrase IX (CA IX) with specific inhibitors is a promising and expanding field as CA IX is involved in tumor progression...
November 28, 2016: Current Molecular Pharmacology
https://www.readbyqxmd.com/read/27893187/-to-twist-or-not-to-twist-figure-of-eight-and-planar-structures-of-octaphyrins
#13
REVIEW
Neelam Shivran, Santosh C Gadekar, Venkataramanarao G Anand
Amongst the various porphyrinoids, octaphyrin has attracted significant attention owing to its diverse syntheses, conformations, and metal-ligation properties. Octaphyrin is a higher homologue of porphyrin and is formed by linking together heterocycles such as pyrrole, furan, thiophene, and selenophene through α-α or α-meso carbon bonds. The planar conformation is mainly achieved through inversion of the heterocyclic units from the center of macrocycle; avoiding meso-bridges; introducing a para-quinodimethane bridge; employing a neo-confusion approach; protonation; and by generating dianionic species...
November 28, 2016: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/27890567/commissioning-of-the-4-d-treatment-delivery-system-for-organ-motion-management-in-synchrotron-based-scanning-ion-beams
#14
Mario Ciocca, Alfredo Mirandola, Silvia Molinelli, Stefania Russo, Edoardo Mastella, Alessandro Vai, Andrea Mairani, Giuseppe Magro, Andrea Pella, Marco Donetti, Francesca Valvo, Piero Fossati, Guido Baroni
PURPOSE: The aim of this work was the commissioning of delivery procedures for the treatment of moving targets in scanning pencil beam hadrontherapy. METHODS: EBT3 films fixed to the Anzai Respiratory Phantom were exposed to carbon ion scanned homogeneous fields (E=332MeV/u). To evaluate the interplay effect, field size and flatness for 3 different scenarios were compared to static condition: gated irradiation or repainting alone and combination of both. Respiratory signal was provided by Anzai pressure sensor or optical tracking system (OTS)...
November 24, 2016: Physica Medica: PM
https://www.readbyqxmd.com/read/27889510/amine-functionalized-multi-arm-star-polymers-a-novel-platform-for-removing-glyphosate-from-aqueous-media
#15
Lianna Samuel, Ran Wang, Geraud Dubois, Robert Allen, Rudy Wojtecki, Young-Hye La
We describe a novel method for efficiently removing glyphosate from aqueous media via adsorption onto highly functionalized star-shaped polymeric particles. These particles have a polystyrene core with more than 35 attached methacrylate polymer arms, each containing a plurality of pendant amines (poly(dimethylamino ethyl methacrylate): PDMAEMA) that are partially protonated in water. Kinetic studies demonstrate that these star-polymers successfully remove up to 93% of glyphosate present in aqueous solution (feed concentration: 5 ppm), within 10 min contact time, outperforming activated carbon, which removed 33% after 20 min...
November 24, 2016: Chemosphere
https://www.readbyqxmd.com/read/27886506/measurement-of-excitation-spectra-in-the-12-c-p-d-reaction-near-the-%C3%AE-emission-threshold
#16
Y K Tanaka, K Itahashi, H Fujioka, Y Ayyad, J Benlliure, K-T Brinkmann, S Friedrich, H Geissel, J Gellanki, C Guo, E Gutz, E Haettner, M N Harakeh, R S Hayano, Y Higashi, S Hirenzaki, C Hornung, Y Igarashi, N Ikeno, M Iwasaki, D Jido, N Kalantar-Nayestanaki, R Kanungo, R Knöbel, N Kurz, V Metag, I Mukha, T Nagae, H Nagahiro, M Nanova, T Nishi, H J Ong, S Pietri, A Prochazka, C Rappold, M P Reiter, J L Rodríguez-Sánchez, C Scheidenberger, H Simon, B Sitar, P Strmen, B Sun, K Suzuki, I Szarka, M Takechi, I Tanihata, S Terashima, Y N Watanabe, H Weick, E Widmann, J S Winfield, X Xu, H Yamakami, J Zhao
Excitation spectra of ^{11}C are measured in the ^{12}C(p,d) reaction near the η^{'} emission threshold. A proton beam extracted from the synchrotron SIS-18 at GSI with an incident energy of 2.5 GeV impinges on a carbon target. The momenta of deuterons emitted at 0° are precisely measured with the fragment separator (FRS) operated as a spectrometer. In contrast to theoretical predictions on the possible existence of deeply bound η^{'}-mesic states in carbon nuclei, no distinct structures are observed associated with the formation of bound states...
November 11, 2016: Physical Review Letters
https://www.readbyqxmd.com/read/27885828/superionic-conductivity-in-hybrid-of-3-hydroxypropanesulfonic-acid-and-graphene-oxide
#17
Kosuke Wakata, Mohammad Razaul Karim, Ryo Ohtani, Masaaki Nakamura, Michio Koinuma, Shinya Hayami
Insertion of 3-hydroxypropanesulfonicacid (HPS) at graphene oxide (GO) interlayer results in high proton conductivity (10-2 - 10-1 Scm-1) due to the improvement in oxygen content, interlayer distance and water absorbing capacity. This result indicates that hydroxyalkylsulfonicacid can be a perfect guest molecules for improving the proton conductivity of carbon materials.
November 25, 2016: Chemistry, An Asian Journal
https://www.readbyqxmd.com/read/27885084/analysis-of-neutron-production-in-passively-scattered-ion-beam-therapy
#18
Seunguk Heo, Seunghoon Yoo, Yongkeun Song, Eunho Kim, Jaeik Shin, Soorim Han, Wongyun Jung, Sanghee Nam, Rena Lee, Kitae Lee, Sungho Cho
A new treatment facility for heavy ion therapy since 2010 was constructed. In the broad beam, a range shifter, ridge filter and multi leaf collimator (MLC) for the generation of the spread-out Bragg peak is used. In this case, secondary neutrons produced by the interactions of the ion field with beam-modifying devices (e.g. double-scattering system, beam shaping collimators and range compensators) are very important for patient safety. Therefore, these components must be carefully examined in the context of secondary neutron yield and associated secondary cancer risk...
November 24, 2016: Radiation Protection Dosimetry
https://www.readbyqxmd.com/read/27883245/a-prediction-of-proton-catalyzed-hydrogenation-of-ketones-in-lewis-basic-solvent-via-facile-splitting-of-hydrogen-molecule
#19
Mojgan Heshmat, Timofei Privalov
A ketone's carbonyl carbon is electrophilic and harbors a part of the lowest unoccupied molecular orbital of the carbonyl group - resembling a Lewis acidic center, under right circumstances it exhibits very useful chemical reactivity although the natural electrophilicity of ketone's carbonyl carbon is often not strong enough per se. Quantum chemical calculations predict that proton shared between a ketone and the Lewis basic solvent molecule (dioxane or THF) activates carbonyl carbon to the point of enabling a facile heterolytic splitting of H2...
November 24, 2016: Chemistry: a European Journal
https://www.readbyqxmd.com/read/27882881/the-mechanism-of-alkene-elimination-from-protonated-toluenesulphonamides-generated-by-electrospray-ionisation
#20
Amie Saidykhan, Jenessa Ebert, William H C Martin, Richard T Gallagher, Richard D Bowen
The positive ion electrospray mass spectra of a range of sulphonamides of general structure CH3C6H4SO2NHR1 [R1 = CnH2n(+1) (n = 1-7), CnH2n-1 (n = 3, 4), C6H5, C6H5CH2 and C6H5CH(CH3)] and CH3C6H4SO2NR1R(2) [R(1), R(2) = CnH2n+1 (n = 1-8)] are reported and discussed. The protonated sulphonamides derived from saturated primary and secondary aliphatic amines generally fragment to only a limited extent unless energised by collision. Two general fragmentations are observed: firstly, elimination of an alkene, CnH2n, obtained by hydrogen abstraction from one of the CnH2n+1 alkyl groups on nitrogen; secondly, cleavage to form CH3C6H4SO2+...
2016: European Journal of Mass Spectrometry
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