keyword
MENU ▼
Read by QxMD icon Read
search

Dissociation

keyword
https://www.readbyqxmd.com/read/28550814/determination-of-equilibrium-structures-of-bromothymol-blue-revealed-by-using-quantum-chemistry-with-an-aid-of-multivariate-analysis-of-electronic-absorption-spectra
#1
Toru Shimada, Takeshi Hasegawa
The pH dependent chemical structures of bromothymol blue (BTB), which have long been under controversy, are determined by employing a combined technique of multivariate analysis of electronic absorption spectra and quantum chemistry. Principle component analysis (PCA) of the pH dependent spectra apparently reveals that only two chemical species are adequate to fully account for the color changes, with which the spectral decomposition is readily performed by using augmented alternative least-squares (ALS) regression analysis...
May 19, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28550299/microfluidic-isolation-of-circulating-tumor-cell-clusters-by-size-and-asymmetry
#2
Sam H Au, Jon Edd, Amy E Stoddard, Keith H K Wong, Fabio Fachin, Shyamala Maheswaran, Daniel A Haber, Shannon L Stott, Ravi Kapur, Mehmet Toner
Circulating tumor cell clusters (CTC clusters) are potent initiators of metastasis and potentially useful clinical markers for patients with cancer. Although there are numerous devices developed to isolate individual circulating tumor cells from blood, these devices are ineffective at capturing CTC clusters, incapable of separating clusters from single cells and/or cause cluster damage or dissociation during processing. The only device currently able to specifically isolate CTC clusters from single CTCs and blood cells relies on the batch immobilization of clusters onto micropillars which necessitates long residence times and causes damage to clusters during release...
May 26, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28550277/escherichia-coli-pagp-enzyme-based-de-novo-design-and-in-vitro-activity-of-antibacterial-peptide-ll-37
#3
Hao Yang, Jingyu Fu, Youyun Zhao, Huiping Shi, Hua Hu, Hongliang Wang
BACKGROUND The aim of this study was to investigate the antimicrobial property of peptide LL-37 sequences. MATERIAL AND METHODS Humanized antibacterial peptide LL-37 and the mutant were prepared by chemical synthesis. The physicochemical properties of antibacterial peptide LL-37 were analyzed by SWISS-MODEL online prediction tool. Molecular docking between antibacterial peptide LL-37 fragments and palmitoyl transferase PagP was made with Lamarckian genetic algorithm by AutoDock1.5.6. RESULTS The systems contacted each other at 8...
May 27, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/28550175/chronic-hypoxia-attenuates-the-vasodilator-efficacy-of-protein-kinase-g-in-fetal-and-adult-ovine-cerebral-arteries
#4
Richard B Thorpe, Margaret C Hubbell, Jinjutha Silpanisong, James M Williams, William J Pearce
Long-term hypoxia (LTH) attenuates nitric oxide (NO) induced vasorelaxation in ovine middle cerebral arteries. Because cGMP-dependent protein kinase (PKG) is an important mediator of NO signaling in vascular smooth muscle, we tested the hypothesis that LTH diminishes the ability of PKG to interact with target proteins and cause vasorelaxation. Prominent among proteins that regulate vascular tone is the large conductance calcium-sensitive potassium (BK) channel, which is a substrate for PKG and is responsive to phosphorylation on multiple serine/threonine residues...
May 26, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28549234/lesion-characteristics-driving-right-hemispheric-language-reorganization-in-congenital-left-hemispheric-brain-damage
#5
Karen Lidzba, Bianca de Haan, Marko Wilke, Ingeborg Krägeloh-Mann, Martin Staudt
Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI...
May 23, 2017: Brain and Language
https://www.readbyqxmd.com/read/28549193/label-free-direct-localization-and-relative-quantitation-of-the-rna-nucleobase-methylations-m6a-m5c-m3u-and-m5u-by-top-down-mass-spectrometry
#6
Heidelinde Glasner, Christian Riml, Ronald Micura, Kathrin Breuker
Nucleobase methylations are ubiquitous posttranscriptional modifications of ribonucleic acids (RNA) that can substantially increase the structural diversity of RNA in a highly dynamic fashion with implications for gene expression and human disease. However, high throughput, deep sequencing does not generally provide information on posttranscriptional modifications (PTMs). A promising alternative approach for the characterization of PTMs, i.e. their identification, localization, and relative quantitation, is top-down mass spectrometry (MS)...
May 26, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28548314/scorpionate-complexes-of-aza-18-crown-6-containing-fluoronitrophenyl-substituents-as-studied-by-esi-ms
#7
Rafał Frański, Magdalena Onyszkiewicz, Błażej Gierczyk
RATIONALE: Coordination of a metal cation by a nitro group is rare and the interaction between them is usually weak. Examples of complexes in which such an interaction takes place are metal complexes of cyclams containing nitrophenyl or nitrobenzyl substituents. It seemed to be interesting to check if in the complexes of respective crown ether conjugates the interaction can also take place. METHODS: We synthesized the respective conjugates of aza-18-crown-6, namely fluoro-substituted N-nitrophenylaza-18C6 conjugates...
May 26, 2017: Rapid Communications in Mass Spectrometry: RCM
https://www.readbyqxmd.com/read/28548226/multimodal-connectivity-based-parcellation-reveals-a-shell-core-dichotomy-of-the-human-nucleus-accumbens
#8
Xiaoluan Xia, Lingzhong Fan, Chen Cheng, Simon B Eickhoff, Junjie Chen, Haifang Li, Tianzi Jiang
The subdifferentiation of the nucleus accumbens (NAc) has been extensively studied using neuroanatomy and histochemistry, yielding a well-accepted dichotomic shell/core architecture that reflects dissociable roles, such as in reward and aversion, respectively. However, in vivo parcellation of these structures in humans has been rare, potentially impairing future research into the structural and functional characteristics and alterations of putative NAc subregions. Here, we used three complementary parcellation schemes based on tractography, task-independent functional connectivity, and task-dependent co-activation to investigate the regional differentiation within the NAc...
May 26, 2017: Human Brain Mapping
https://www.readbyqxmd.com/read/28548178/stereospecific-control-of-the-metal-centred-chirality-of-rhodium-iii-and-iridium-iii-complexes-bearing-tetradentate-cnn-p-ligands
#9
María Carmona, Ricardo Rodríguez, Isabel Méndez, Vincenzo Passarelli, Fernando J Lahoz, Pilar García-Orduña, Daniel Carmona
Ligands LH1-LH3 have been prepared by two successive condensation/reduction steps. These ligands react with MCl3 (M = Rh, Ir) rendering the trichlorido complexes [MCl3(κ(3)N,N',P-LH)] (M = Rh, LH = LH1 (1), LH2 (2), LH3 (3); M = Ir, LH = LH1, (4)) as racemic mixtures of fac and mer isomers. Only one of the two possible fac isomers was detected. The mer isomer of the rhodium compounds 1-3 quantitatively isomerizes to the more stable fac isomer, whereas the mer isomer of the iridium complex 4 does not. DFT calculations indicate a dissociative pathway for this isomerization...
May 26, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28548169/photophysicochemical-characterization-of-mycosporine-like-amino-acids-in-micellar-solutions
#10
D E Orallo, S G Bertolotti, M S Churio
The properties and photochemical and photophysical behavior of the mycosporine-like amino acids (MAAs) shinorine and porphyra-334 were experimentally evaluated in solutions of direct ionic micelles as simple biomimicking environments. The preferential partition of the natural molecules in the aqueous phase of sodium dodecyl sulfate (SDS) or cetyltrimethylammonium chloride (CTAC) micellar systems is confirmed. Although the proton dissociation of the carboxylic groups in the MAAs is slightly inhibited in CTAC solutions, the molecules are predicted to be in the form of zwitterions in all the explored media around physiological pH...
May 26, 2017: Photochemical & Photobiological Sciences
https://www.readbyqxmd.com/read/28548027/dissociation-between-preserved-body-structural-description-and-impaired-body-image-following-a-pediatric-spinal-trauma
#11
Gerardo Salvato, Valeria Peviani, Elisa Scarano, Pina Scarpa, Alessandra Leo, Tiziana Redaelli, Michele Spinelli, Maurizio Sberna, Gabriella Bottini
In adult patients, Spinal Cord Injury (SCI) may influence the mental Body Representation (BR). Currently, there is no evidence on the modulation of SCI on BR during early stages of cognitive development. Here, we investigated BR in a 3-year-old child with complete SCI. The patient was administered with a specific battery assessing different BR components. We found evidence for putative classical neuropsychological dissociation between a preserved topological map with impaired semantic knowledge of the body...
May 26, 2017: Neurocase
https://www.readbyqxmd.com/read/28547925/blockade-of-the-dissociation-of-nmmhc-iia-from-tnfr2-by-d39-a-saponin-from-liriope-muscari-suppresses-tissue-factor-expression-and-venous-thrombosis
#12
Ke-Feng Zhai, Jin-Rong Zheng, You-Mei Tang, Fang Li, Yan-Ni Lv, Yuan-Yuan Zhang, Zhen Gao, Jin Qi, Bo-Yang Yu, Jun-Ping Kou
BACKGROUND AND PURPOSE: Non-muscular myosin heavy chain IIA (NMMHC IIA) has been demonstrated to play a key role in tissue factor (TF) expression and venous thrombosis. However, whether natural products could inhibit thrombosis via NMMHC IIA remains unclear. In this study, we identified that a representative natural saponin D39 from Liriope muscari showed anti-thrombotic activity by targeting NMMHC IIA. EXPERIMENTAL APPROACH: TF expression and activity in endothelial cells were analysed in vitro by western blot and simplified chromogenic assays...
May 26, 2017: British Journal of Pharmacology
https://www.readbyqxmd.com/read/28547843/characterization-of-protonated-model-disaccharides-from-tandem-mass-spectrometry-and-chemical-dynamics-simulations
#13
Estefania Rossich-Molina, Ane Eizaguirre, Violette Haldys, Dominique Urban, Gilles Doisneau, Yann Bourdreux, Jean-Marie Beau, Jean-Yves Salpin, Riccardo Spezia
In the present work the fragmentation mechanisms of prototypical disaccharides have been studied by coupling tandem mass spectrometry (MS) with collisional chemical dynamics simulations. These last calculations were performed by explicitly considering the collisions between the protonated sugar and the neutral target gas, leading to an ensemble of trajectories for each system, from which it was possible to obtain reaction products and mechanisms without pre-imposing them. The -aminoethyl and aminopropyl derivatives of cellobiose, maltose and gentiobiose were studied in order to see the differences in both the stereochemistry and the location of the glycosidic linkage...
May 26, 2017: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
https://www.readbyqxmd.com/read/28547785/alkynyl-n-nosylhydrazones-easy-decomposition-to-alknynl-diazomethanes-and-application-for-allene-synthesis
#14
Xihe Bi, Yang Yang, Zhaohong Liu, Alessio Porta, Giuseppe Zanoni
The dissociation of N-tosylhydrazones is a safe and convenient method for the generation of donor carbenes. However, alkynyl carbenes cannot be isolated by this route because they readily undergo intramolecular cyclization to pyrazoles as soon as formed from alkynyl N-tosylhydrazones. Herein we report the use of alkynyl N-nosylhydrazones for the in situ generation of alkynyl carbenes and their coupling reaction with boronic acids under metal-free conditions, giving rise to a wide array of di- and trisubstituted allenes...
May 26, 2017: Chemistry: a European Journal
https://www.readbyqxmd.com/read/28547725/dual-polarity-ion-trap-mass-spectrometry-dynamic-monitoring-and-controlling-gas-phase-ion-ion-reactions
#15
Muyi He, You Jiang, Dan Guo, Xingchuang Xiong, Xiang Fang, Wei Xu
A dual-polarity linear ion trap (LIT) mass spectrometer was developed in this study, and the method for simultaneously controlling and detecting cations and anions was proposed and realized in the LIT. With the application of an additional dipolar DC field on the ejection electrodes of an LIT, dual-polarity mass spectra could be obtained, which include both the mass-to-charge (m/z) ratio and charge polarity information of an ion. Compared with conventional method, the ion ejection and detection efficiency could also be improved by about one-fold...
May 25, 2017: Journal of the American Society for Mass Spectrometry
https://www.readbyqxmd.com/read/28547677/episodic-and-semantic-content-of-memory-and-imagination-a-multilevel-analysis
#16
Aleea L Devitt, Donna Rose Addis, Daniel L Schacter
Autobiographical memories of past events and imaginations of future scenarios comprise both episodic and semantic content. Correlating the amount of "internal" (episodic) and "external" (semantic) details generated when describing autobiographical events can illuminate the relationship between the processes supporting these constructs. Yet previous studies performing such correlations were limited by aggregating data across all events generated by an individual, potentially obscuring the underlying relationship within the events themselves...
May 25, 2017: Memory & Cognition
https://www.readbyqxmd.com/read/28547121/a-precise-method-for-processing-data-to-determine-the-dissociation-constants-of-polyhydroxy-carboxylic-acids-via-potentiometric-titration
#17
Kaixuan Huang, Yong Xu, Wen Lu, Shiyuan Yu
The thermodynamic dissociation constants of xylonic acid and gluconic acid were studied via potentiometric methods, and the results were verified using lactic acid, which has a known pKa value, as a model compound. Solutions of xylonic acid and gluconic acid were titrated with a standard solution of sodium hydroxide. The determined pKa data were processed via the method of derivative plots using computer software, and the accuracy was validated using the Gran method. The dissociation constants associated with the carboxylic acid group of xylonic and gluconic acids were determined to be pKa1 = 3...
May 25, 2017: Applied Biochemistry and Biotechnology
https://www.readbyqxmd.com/read/28546558/probing-the-roles-of-calcium-binding-sites-during-the-folding-of-human-peptidylarginine-deiminase-4
#18
Yi-Liang Liu, Chien-Yun Lee, Yu-Ni Huang, Hui-Yi Chen, Guang-Yaw Liu, Hui-Chih Hung
Our recent studies of peptidylarginine deiminase 4 (PAD4) demonstrate that its non-catalytic Ca(2+)-binding sites play a crucial role in the assembly of the correct geometry of the enzyme. Here, we examined the folding mechanism of PAD4 and the role of Ca(2+) ions in the folding pathway. Multiple mutations were introduced into the calcium-binding sites, and these mutants were termed the Ca1_site, Ca2_site, Ca3_site, Ca4_site and Ca5_site mutants. Our data indicate that during the unfolding process, the PAD4 dimer first dissociates into monomers, and the monomers then undergo a three-state denaturation process via an intermediate state formation...
May 25, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28546513/the-siah-e3-ubiquitin-ligases-promote-wnt-%C3%AE-catenin-signaling-through-mediating-wnt-induced-axin-degradation
#19
Lei Ji, Bo Jiang, Xiaomo Jiang, Olga Charlat, Amy Chen, Craig Mickanin, Andreas Bauer, Wenqing Xu, Xiaoxue Yan, Feng Cong
The Wnt/β-catenin signaling pathway plays essential roles in embryonic development and adult tissue homeostasis. Axin is a concentration-limiting factor responsible for the formation of the β-catenin destruction complex. Wnt signaling itself promotes the degradation of Axin. However, the underlying molecular mechanism and biological relevance of this targeting of Axin have not been elucidated. Here, we identify SIAH1/2 (SIAH) as the E3 ligase mediating Wnt-induced Axin degradation. SIAH proteins promote the ubiquitination and proteasomal degradation of Axin through interacting with a VxP motif in the GSK3-binding domain of Axin, and this function of SIAH is counteracted by GSK3 binding to Axin...
May 25, 2017: Genes & Development
https://www.readbyqxmd.com/read/28546312/prefrontal-dopamine-d1-and-d2-receptors-regulate-dissociable-aspects-of-decision-making-via-distinct-ventral-striatal-and-amygdalar-circuits
#20
Nicole L Jenni, Joshua D Larkin, Stan B Floresco
Mesocortical dopamine (DA) regulates a variety of cognitive functions via actions on D1 and/or D2 receptors. For example, risk/reward decision making is differentially modulated by these two receptors within the prefrontal cortex (PFC), with D2 receptors enabling flexible decision making and D1 receptors promoting persistence in choice biases. Yet, it is unclear how DA mediates opposing patterns of behavior by acting on different receptors within the same terminal region. We explored the possibility that DA may act on separate networks of PFC neurons that are modulated by D1 or D2 receptors and in turn interface with divergent downstream structures, such as the basolateral amygdala (BLA) or nucleus accumbens (NAc)...
May 25, 2017: Journal of Neuroscience: the Official Journal of the Society for Neuroscience
keyword
keyword
5323
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"