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https://www.readbyqxmd.com/read/28719508/is-the-organisation-of-the-primary-motor-cortex-in-low-back-pain-related-to-pain-movement-and-or-sensation
#1
Edith Elgueta-Cancino, Siobhan Schabrun, Paul Hodges
Primary motor cortex (M1) organisation differs between individuals with and without chronic low back pain (CLBP), in parallel with motor and sensory impairments. This study investigated whether movement behaviour and tactile/pain sensation are related to M1 organisation in CLBP. Transcranial magnetic stimulation (TMS) was used to map the M1 representation of the erector spinae and multifidus muscles in 20 participants with and without CLBP. Cortical organisation was quantified by: map volume; center of gravity (CoG); number of peaks; and primary and secondary peak location...
July 17, 2017: Clinical Journal of Pain
https://www.readbyqxmd.com/read/28719196/thermoresponsive-elastin-b-collagen-like-peptide-bioconjugate-nanovesicles-for-targeted-drug-delivery-to-collagen-containing-matrices
#2
Tianzhi Luo, Michael A David, Lucas C Dunshee, Rebecca A Scott, Morgan A Urello, Christopher Price, Kristi L Kiick
Over the past few decades, (poly)peptide block copolymers have been widely employed in generating well-defined nanostructures as vehicles for targeted drug delivery applications. We previously reported the assembly of thermoresponsive nanovesicles from an elastin-b-collagen like peptide (ELP-CLP). The nanoparticles were observed to dissociate at elevated temperatures, despite the LCST-like behavior of the tethered ELP domain, which is suggested to be triggered by the unfolding of the CLP domain. Here, the potential of using the nanoparticles as drug delivery vehicles for targeting collagen-containing matrices is evaluated...
July 18, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28719153/in-source-collision-induced-dissociation-is-cid-applications-issues-and-structure-elucidation-with-single-stage-mass-analyzers
#3
Jon F Parcher, Mei Wang, Amar G Chittiboyina, Ikhlas A Khan
A discussion of the definition, advantages and issues with the formation of ions in the transition region between an ESI source and the ion optics of a mass analyzer is presented. The various types of ions formed in the so-called in-source collision induced dissociation (IS-CID) process are illustrated. Applications of IS-CID with single-stage mass analyzers, such as structure elucidation and quantitation, are demonstrated. The discussion is illustrated by examples of the in-source fragmentation of ginkgolides, which are marker compounds found only in Ginkgo biloba...
July 18, 2017: Drug Testing and Analysis
https://www.readbyqxmd.com/read/28718892/methoxetamine-affects-brain-processing-involved-in-emotional-response-in-rats
#4
M T Zanda, P Fadda, S Antinori, M di Chio, W Fratta, C Chiamulera, L Fattore
BACKGROUND AND PURPOSE: Methoxetamine (MXE) is a novel psychoactive substance that is emerging on the Internet and induces dissociative effects and acute toxicity. Yet, its pharmacological effects are still poorly investigated. EXPERIMENTAL APPROACH: We examined a range of behavioural effects induced by acute intraperitoneal administration of MXE (0.5-5 mg/kg) in rats, and whether it causes rapid neuroadaptive molecular changes. KEY RESULTS: MXE (0...
July 18, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28718640/smi2-h2o-n-reductions-of-electron-rich-enamines-by-concerted-proton-coupled-electron-transfer
#5
Scott S Kolmar, James M Mayer
Samarium diiodide in the presence of water and THF (SmI2(H2O)n) has in recent years become a versatile and useful reagent, mainly for reducing carbonyl-type substrates. This work reports the reduction of several enamines by SmI2(H2O)n. Mechanistic experiments implicate a concerted proton-coupled electron transfer (PCET) pathway, based on various evidence against initial outer-sphere electron transfer, proton transfer or substrate coordination. A thermochemical analysis indicates that the C-H bond formed in the rate determining step has a bond dissociation free energy (BDFE) of ~32 kcal mol-1...
July 18, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28718635/undervalued-n3-coordination-revealed-in-the-cisplatin-complex-with-2-deoxyadenosine-5-monophosphate-by-a-combined-irmpd-and-theoretical-study
#6
Barbara Chiavarino, Maria Elisa Crestoni, Simonetta Fornarini, Debora Scuderi, Jean-Yves Salpin
The complex obtained by the reaction of cisplatin and 2'-deoxyadenosine-5'-monophosphate (5'-dAMP) in water has been isolated and detected by electrospray ionization mass spectrometry. The so-formed cis-[PtCl(NH3)2(5'-dAMP)](+) complex has been studied in detail by infrared multiple photon dissociation (IRMPD) spectroscopy in two spectral ranges, namely, 700-1900 and 2800-3800 cm(-1), backed by quantum-chemical calculations at the B3LYP/LACV3P/6-311G** level of theory. In agreement with the computational results, the vibrational spectroscopic characterization of cis-[PtCl(NH3)2(5'-dAMP)](+) shows that the sampled ionic population comprises two major isomers, differentiated in the X-H stretching region by their distinct fragmentation patterns...
July 18, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28718617/initial-reduction-of-co2-on-pd-ru-and-cu-doped-ceo2-111-surfaces-effects-of-surface-modification-on-catalytic-activity-and-selectivity
#7
Chen Guo, Shuxian Wei, Sainan Zhou, Tian Zhang, Zhaojie Wang, Siu Pang Ng, Xiaoqing Lu, Chi-Man Lawrence Wu, Wenyue Guo
Surface modification by metal doping is an effective treatment technique for improving surface properties for CO2 reduction. Herein, the effects of doped Pd, Ru, and Cu on the adsorption, activation, and reduction selectivity of CO2 on CeO2(111) were investigated by periodic density functional theory. The doped metals distorted the configuration of a perfect CeO2(111) by weakening the adjacent Ce-O bond strength, and Pd doping was beneficial for generating a highly active O vacancy. The analyses of adsorption energy, charge density difference, and density of states confirmed that the doped metals were conducive for enhancing CO2 adsorption, especially for Cu/CeO2(111)...
July 18, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28718470/co2-activation-and-dissociation-on-the-low-miller-index-surfaces-of-pure-and-ni-coated-iron-metal-a-dft-study
#8
Caroline R Kwawu, Richard Tia, Evans Adei, Nelson Y Dzade, C Richard A Catlow, Nora H de Leeuw
We have used spin polarized density functional theory calculations to perform extensive mechanistic studies of CO2 dissociation into CO and O on the clean Fe(100), (110) and (111) surfaces and on the same surfaces coated by a monolayer of nickel. CO2 chemisorbs on all three bare facets and binds more strongly to the stepped (111) surface than on the open flat (100) and close-packed (110) surfaces, with adsorption energies of -88.7 kJ mol(-1), -70.8 kJ mol(-1) and -116.8 kJ mol(-1) on the (100), (110) and (111) facets, respectively...
July 18, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28718067/theoretical-and-experimental-in-vivo-study-of-antioxidant-activity-of-crocin-in-order-to-propose-novel-derivatives-with-higher-antioxidant-activity-and-their-delivery-via-nanotubes-and-nanocones
#9
Houshang Najafi, Zeynab Mohamadi Yarijani, Meysam Najafi
In this study, the antioxidant activity of crocin via experimental and theoretical methods was investigated. In order to induce oxidative stress, 30-min renal ischemia and 24-h reperfusion were used in male Wistar rats. Oxidative stress was assessed by measuring tissue malondialdehyde (MDA) and ferric reducing/antioxidant power (FRAP). The results showed that following ischemia/reperfusion, the level of MDA was increased and FRAP decreased. Both of these changes were alleviated by crocin administration. The bond dissociation enthalpy and ionization potential values as enthalpies of mechanism of antioxidant activity of crocin were calculated by density functional theory method...
July 17, 2017: Inflammation
https://www.readbyqxmd.com/read/28717192/torque-but-not-flil-regulates-mechanosensitive-flagellar-motor-function
#10
Ravi Chawla, Katie M Ford, Pushkar P Lele
The stator-complex in the bacterial flagellar motor is responsible for surface-sensing. It remodels in response to perturbations in viscous loads, recruiting additional stator-units as the load increases. Here, we tested a hypothesis that the amount of torque generated by each stator-unit modulates its association with the rotor. To do this, we measured stator-binding to the rotor in mutants in which motors reportedly develop lower torque compared to wildtype motors. First, we employed a strain lacking fliL...
July 17, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28717005/lipid-oxidation-inactivates-the-anticoagulant-function-of-protein-z-dependent-protease-inhibitor-zpi
#11
Xin Huang, Baoxin Liu, Yidong Wei, Ryan Beyea, Han Yan, Steven T Olson
Lipid oxidation due to oxidative stress plays an important role in the pathogenesis of inflammatory and thrombotic cardiovascular diseases. Several findings suggest that lipid peroxidation can alter the function of coagulation proteins and contribute to a hypercoagulable state, but the molecular mechanisms are unclear. Here, we report that oxidized phospholipids suppress the anticoagulant function of the serpin, protein Z-dependent protease inhibitor (ZPI), a specific inhibitor of membrane-associated factor Xa (FXa) that requires protein Z (PZ), phospholipid and calcium as cofactors...
July 17, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/28716966/hierarchically-organized-medial-frontal-cortex-basal-ganglia-loops-selectively-control-task-and-response-selection
#12
Franziska M Korb, Jiefeng Jiang, Joseph A King, Tobias Egner
Adaptive behavior requires context-sensitive configuration of task-sets that specify time-varying stimulus-response mappings. Intriguingly, response time costs associated with changing task-sets and motor responses are known to be strongly interactive: switch costs at the task-level are small in the presence of a response-switch but large when accompanied by a response-repetition, and vice versa for response-switch costs. The reasons behind this well-known inter-dependence between task- and response-level control processes are currently not well understood...
July 17, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
https://www.readbyqxmd.com/read/28716952/differential-involvement-of-the-medial-prefrontal-cortex-across-variants-of-contextual-fear-conditioning
#13
Nicholas A Heroux, Patrese A Robinson-Drummer, Hollie R Sanders, Jeffrey B Rosen, Mark E Stanton
The context preexposure facilitation effect (CPFE) is a contextual fear conditioning paradigm in which learning about the context, acquiring the context-shock association, and retrieving/expressing contextual fear are temporally dissociated into three distinct phases. In contrast, learning about the context and the context-shock association happens concurrently in standard contextual fear conditioning (sCFC). By infusing the GABAA receptor agonist muscimol into medial prefrontal cortex (mPFC) in adolescent Long-Evans rats, the current set of experiments examined the functional role of the mPFC in each phase of the CPFE and sCFC...
August 2017: Learning & Memory
https://www.readbyqxmd.com/read/28716944/potent-competitive-inhibition-of-human-ribonucleotide-reductase-by-a-nonnucleoside-small-molecule
#14
Md Faiz Ahmad, Intekhab Alam, Sarah E Huff, John Pink, Sheryl A Flanagan, Donna Shewach, Tessianna A Misko, Nancy L Oleinick, William E Harte, Rajesh Viswanathan, Michael E Harris, Chris Godfrey Dealwis
Human ribonucleotide reductase (hRR) is crucial for DNA replication and maintenance of a balanced dNTP pool, and is an established cancer target. Nucleoside analogs such as gemcitabine diphosphate and clofarabine nucleotides target the large subunit (hRRM1) of hRR. These drugs have a poor therapeutic index due to toxicity caused by additional effects, including DNA chain termination. The discovery of nonnucleoside, reversible, small-molecule inhibitors with greater specificity against hRRM1 is a key step in the development of more effective treatments for cancer...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716938/dynamic-responses-of-the-adrenal-steroidogenic-regulatory-network
#15
Francesca Spiga, Eder Zavala, Jamie J Walker, Zidong Zhao, John R Terry, Stafford L Lightman
The hypothalamic-pituitary-adrenal axis is a dynamic system regulating glucocorticoid hormone synthesis in the adrenal glands. Many key factors within the adrenal steroidogenic pathway have been identified and studied, but little is known about how these factors function collectively as a dynamic network of interacting components. To investigate this, we developed a mathematical model of the adrenal steroidogenic regulatory network that accounts for key regulatory processes occurring at different timescales...
July 17, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28716724/the-ppar%C3%AE-activator-fenofibrate-inhibits-voltage-dependent-k-channels-in-rabbit-coronary-arterial-smooth-muscle-cells
#16
Hongliang Li, Sung Eun Shin, Mi Seon Seo, Jin Ryeol An, Won-Kyo Jung, Kwon-Soo Ha, Eun-Taek Han, Seok-Ho Hong, Hyoweon Bang, Young Min Bae, Amy L Firth, Il-Whan Choi, Won Sun Park
We examined the effects of the PPARα activator fenofibrate on voltage-dependent K(+) (Kv) channels using a patch clamp technique in native rabbit coronary arterial smooth muscle cells. Kv current was inhibited by application of fenofibrate in a concentration-dependent manner, with an apparent IC50 value of 6.39 ± 0.53μM and a slope value (Hill coefficient) of 1.63 ± 0.10. Fenofibrate accelerated the decay rate of Kv channel inactivation. The rate constants of association and dissociation for fenofibrate were 0...
July 14, 2017: European Journal of Pharmacology
https://www.readbyqxmd.com/read/28716550/co-deteriorations-of-anisotropic-extracellular-matrix-arrangement-and-intrinsic-mechanical-property-in-c-src-deficient-osteopetrotic-mouse-femur
#17
Takuya Ishimoto, Bunji Sato, Jee-Wook Lee, Takayoshi Nakano
Osteopetrotic bone shows dissociation between bone mineral density (BMD) and bone strength. In this study, volumetric BMD; preferential orientation of the extracellular matrix (ECM), which is composed of collagen fibers and apatite crystals as bone material quality; and mechanical properties of the src(-/-) osteopetrotic and normal mouse femoral cortical bone were analyzed and compared with each other at a bone tissue level. The degree of preferential orientation of ECM along the femoral long axis was significantly decreased in the src(-/-) mice femur, suggesting deteriorated bone quality...
July 14, 2017: Bone
https://www.readbyqxmd.com/read/28715638/marcus-theory-of-ion-pairing
#18
Santanu Roy, Marcel D Baer, Christopher J Mundy, Gregory K Schenter
We present a theory for ion pair dissociation and association, motivated by the concepts of the Marcus theory of electron transfer. Despite the extensive research on ion-pairing in many chemical and biological processes, much can be learned from the exploration of collective reaction coordinates. To this end, we explore two reaction coordinates, ion pair distance and coordination number. The study of the correlation between these reaction coordinates provides a new insight into the mechanism and kinetics of ion pair dissociation and association in water...
July 17, 2017: Journal of Chemical Theory and Computation
https://www.readbyqxmd.com/read/28714693/stochastic-simulation-of-dopamine-neuromodulation-for-implementation-of-fluorescent-neurochemical-probes-in-the-striatal-extracellular-space
#19
Abraham Beyene, Ian McFarlane, Rebecca Pinals, Markita P Landry
Imaging the dynamic behavior of neuromodulatory neurotransmitters in the extracelluar space arising from individual quantal releases would constitute a major advance in neurochemical imaging. Spatial and temporal resolution of these highly stochastic neuromodulatory events requires concurrent advances in the chemical development of optical nanosensors selective for neuromodulators in concert with advances in imaging methodologies to capture millisecond neurotransmitter release. Herein, we develop and implement a stochastic model to describe dopamine dynamics in the extracellular space (ECS) of the brain dorsal striatum to guide the design and implementation of fluorescent neurochemical probes that record neurotransmitter dynamics in the ECS...
July 17, 2017: ACS Chemical Neuroscience
https://www.readbyqxmd.com/read/28714476/modulation-of-nongenomic-activation-of-pi3k-signalling-by-tetramerization-of-n-terminally-cleaved-rxr%C3%AE
#20
Liqun Chen, Alexander E Aleshin, Gulimiran Alitongbieke, Yuqi Zhou, Xindao Zhang, Xiaohong Ye, Mengjie Hu, Gaoang Ren, Ziwen Chen, Yue Ma, Duo Zhang, Shuai Liu, Weiwei Gao, Lijun Cai, Lingjuan Wu, Zhiping Zeng, Fuquan Jiang, Jie Liu, Hu Zhou, Gregory Cadwell, Robert C Liddington, Ying Su, Xiao-Kun Zhang
Retinoid X receptor-alpha (RXRα) binds to DNA either as homodimers or heterodimers, but it also forms homotetramers whose function is poorly defined. We previously discovered that an N-terminally-cleaved form of RXRα (tRXRα), produced in tumour cells, activates phosphoinositide 3-kinase (PI3K) signalling by binding to the p85α subunit of PI3K and that K-80003, an anti-cancer agent, inhibits this process. Here, we report through crystallographic and biochemical studies that K-80003 binds to and stabilizes tRXRα tetramers via a 'three-pronged' combination of canonical and non-canonical mechanisms...
July 17, 2017: Nature Communications
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