The catalytic cycle of numerous enzymes involves the coupling between proton transfer and electron transfer. Yet, the understanding of this coordinated transfer in biological systems remains limited, likely because its characterization relies on the controlled but experimentally challenging modifications of the free energy changes associated with either the electron or proton transfer. We have ...

purpose: to evaluate of proton therapy (pt) for neurosurgery patients and is also to explain the need for this system in iran. methods: a literature review was conducted (1984–2016). the strategy included a combination of keywords including proton therapy, neck, neurosurgery, brain, head, tumor, spine, arteriovenous malformation (avms), cervical and spine in database of pubmed. new generation p...

Background: The purpose of this paper is to establish an easy and reliable biodosimeter protocol to evaluate the biological effects of proton beams. Materials and Methods: Human peripheral blood lymphocytes were irradiated using proton beams (LET: 34.6 keV μm−1), and the chromosome aberrations induced were analyzed using cytokinesis-blocked (CB) micronucleus (MN) assay. To determine th...

Introduction: Proton therapy delivers radiation to tumor tissue in a much more confined way than conventional photon therapy thus allowing the radiation oncologist to use a greater dose while still minimizing side.   Materials and Methods: protons release most of their energy within the tumor region. As a result, the treating physician can potentially give an...

A comparison between existing nuclear magnetic resonance measurements and calculations of the scalar spin-spin interaction (J coupling) in deuterated molecular hydrogen yields stringent constraints on anomalous spin-dependent potentials between nucleons at the atomic scale (∼ 1 Å). The dimensionless coupling constant g(P)(p)g(P)(N)/4 π associated with the exchange of pseudoscalar (axionlike) bo...

ATP-binding cassette transporters mediate the transbilayer movement of a vast number of substrates in or out of cells in organisms ranging from bacteria to humans. Current alternating access models for ABC exporters including the multidrug and Lipid A transporter MsbA from Escherichia coli suggest a role for nucleotide as the fundamental source of free energy. These models involve cycling betwe...

in order to find the susceptibility of the claisen rearrangement and next proton shift reaction of ally) aryl etherto the substiment effects in pan position, the kinetic and the:rmodynamie parameters are calculated at the33 ltp level using 6-3110. b asis set. the calculated activation energies for the rearrangements and protonshift reactions are around 3133 kcaumol and 52.16 kcal/mol, nap.. liv...

ATP synthase is a unique rotary machine that uses the transmembrane electrochemical potential difference of proton (Delta(H(+))) to synthesize ATP from ADP and inorganic phosphate. Charge translocation by the enzyme can be most conveniently followed in chromatophores of phototrophic bacteria (vesicles derived from invaginations of the cytoplasmic membrane). Excitation of chromatophores by a sho...