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https://www.readbyqxmd.com/read/28640601/initiation-of-the-electrochemical-reduction-of-co2-by-a-singly-reduced-ruthenium-ii-bipyridine-complex
#1
Srinivasan Ramakrishnan, Christopher E D Chidsey
The one-electron reduction of [CpRu(bpy)NCCH3]PF6 (Cp = cyclopentadienyl; bpy = 2,2'-bipyridine), abbreviated as [Ru-S](+), where S = CH3CN, in CO2-saturated acetonitrile initiates a cascade of rapid electrochemical and chemical steps (ECEC) at an electrode potential of ca. 100 mV positive of the first reduction of the ruthenium complex. The overall two-electron process leads to the generation of a CO-bound ruthenium complex, [Ru-CO](+), and carbonate, as independently confirmed by NMR spectroscopy. Simulations of the cyclic voltammograms using DigiElch together with density functional theory based calculations reveal that the singly reduced ruthenium complex [Ru-S](0) binds CO2 at a rate of ca...
June 22, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/28637240/tfeb-activation-restores-migration-ability-to-tsc1-deficient-adult-neural-stem-progenitor-cells
#2
Alessandro Magini, Alice Polchi, Danila Di Meo, Giuseppina Mariucci, Krizia Sagini, Federico De Marco, Tommaso Cassano, Stefano Giovagnoli, Diego Dolcetta, Carla Emiliani
Tuberous sclerosis complex (TSC) is an autosomal dominant genetic disorder caused by mutations in either of two genes, TSC1 or TSC2, resulting in the constitutive activation of the mammalian target of rapamycin complex 1 (mTORC1). mTOR inhibitors are now considered the treatment of choice for TSC disease. A major pathological feature of TSC is the development of subependymal giant cell astrocytomas (SEGAs) in the brain. Nowadays, it is thought that SEGAs could be a consequence of aberrant aggregation and migration of neural stem/progenitor cells (NSPCs)...
June 14, 2017: Human Molecular Genetics
https://www.readbyqxmd.com/read/28636288/the-first-total-synthesis-of-ovafolinin-a-and-b-unique-polycyclic-benzoxepin-lignans-via-a-cascade-cyclization
#3
Samuel James Davidson, David Barker
Ovafolinins A and B, isolated from Lyonia ovalifolia var. elliptica, are lignans which contain a unique penta- and tetracyclic benzoxepin bridged aryl tetralin structure. We report the first total synthesis of these natural products initially utilizing an acyl-Claisen rearrangement to construct the lignan backbone with correct relative stereochemistry. Judicious use of a bulky protecting group placed reactive moieties in the correct orientation resulting in a cascade reaction forming the benzoxepin bridged aryl tetralin from a linear precursor in a single step...
June 21, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28636077/arabidopsis-shaker-pollen-inward-k-channel-spik-functions-in-snrk1-complex-regulated-pollen-hydration-on-the-stigma
#4
Dan-Dan Li, Huan Guan, Fei Li, Chang-Zhen Liu, Yu-Xiu Dong, Xian-Sheng Zhang, Xin-Qi Gao
Pollen hydration is a critical step that determines pollen germination on stigma. KINβγ is a plant-specific subunit of the SNF1-related protein kinase 1 complex (SnRK1 complex). In pollen of the Arabidopsis kinβγ mutant, the levels of reactive oxygen species (ROS) were decreased which lead to compromised hydration of the mutant pollen on stigma. In this study, we analyzed gene expression in kinβγ mutant pollen by RNA-seq and found the expression of inward shaker K(+) channel SPIK was down-regulated in the kinβγ pollen...
June 21, 2017: Journal of Integrative Plant Biology
https://www.readbyqxmd.com/read/28635281/reactions-of-criegee-intermediates-with-alcohols-at-air-aqueous-interfaces
#5
Shinichi Enami, Agustin J Colussi
The fate of Criegee intermediates (CIs) from the gas-phase ozonolysis of unsaturated organic compounds in the troposphere is largely controlled by their reactions with water vapor. We recently found that against all expectations carboxylic acids compete at millimolar concentrations with water for CIs at the air-liquid interface of aqueous organic media. This outcome is consistent with both the low water concentration in the outermost interfacial layers and the enrichment of the competing acids therein. Here we show, via on-line electrospray mass spectrometric detection, that CIs generated in situ in the fast ozonolysis of sesquiterpenes (C15H24) on the surface of water:acetonitrile microjets react with n ≥ 4 linear alcohols CnH2n+1OH to produce high molecular weight Cn+15 ethers in one-step...
June 21, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/28633978/airborne-nitro-pahs-induce-nrf2-are-defense-system-against-oxidative-stress-and-promote-inflammatory-process-by-activating-pi3k-akt-pathway-in-a549-cells
#6
Yu Shang, Qian Zhou, Tiantian Wang, Yuting Jiang, Yufang Zhong, Guangren Qian, Tong Zhu, Xinghua Qiu, Jing An
Ambient particulate matter (PM) is a worldwide health issue of concern. However, limited information is available regarding the toxic contributions of the nitro-derivatives of polycyclic aromatic hydrocarbons (nitro-PAHs). This study intend to examine whether 1-nitropyrene (1-NP) and 3-nitrofluoranthene (3-NF) could activate the nuclear factor-erythroid 2-related factor 2/antioxidant response element (Nrf2/ARE) antioxidant defense system, and whether the phosphatidylinositol 3-kinase/protein kinase B (PI3K/Akt) pathway participates in regulating pro-inflammatory responses in A549 cells...
June 17, 2017: Toxicology in Vitro: An International Journal Published in Association with BIBRA
https://www.readbyqxmd.com/read/28631802/aqueous-tantalum-polyoxometalate-reactivity-with-peroxide
#7
Lauren B Fullmer, Christopher E Malmberg, Dylan B Fast, Lindsay A Wills, Paul Ha-Yeon Cheong, Michelle R Dolgos, May Nyman
Peroxide ligation of aqueous metal-oxo clusters provides rich speciation and structural diversity, radiation sensitivity for manipulation with light, and both broadens and shifts pH-range stability. Here we demonstrate peroxide ligation of the polyoxometalate (POM) [Ta6O19](8-). We study in detail solution speciation of the peroxide-substituted cluster, and benchmark it to the peroxide-ligated niobate analogue, [Nb6O10(OH)3(O2)6](5-), whose solid-state structure has been reported. Raman and electrospray ionization mass spectroscopy do not detect any significant differences between the two analogues...
June 20, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28630946/differentiation-and-inflammation-best-enemies-in-gastrointestinal-carcinogenesis
#8
Nathan M Krah, L Charles Murtaugh
While recent studies demonstrate that cancer can arise from mutant stem cells, this hypothesis does not explain why tissues without defined stem cell populations are susceptible to inflammation-driven tumorigenesis. We propose that chronic inflammatory diseases, such as colitis and pancreatitis, predispose to gastrointestinal (GI) adenocarcinoma by reprogramming differentiated cells. Focusing on colon and pancreas, we discuss recently discovered connections between inflammation and loss of cell differentiation, and propose that dysregulation of cell fate may be a novel rate-limiting step of tumorigenesis...
December 2016: Trends in Cancer
https://www.readbyqxmd.com/read/28629589/physical-exercise-and-dna-injury-good-or-evil
#9
Elisa Danese, Giuseppe Lippi, Fabian Sanchis-Gomar, Giorgio Brocco, Manfredi Rizzo, Maciej Banach, Martina Montagnana
Regular, low-intensity physical activity is currently advocated for lowering the risk of developing many acute and especially chronic diseases. However, several lines of evidence attest that strenuous exercise may enhance inflammation and trigger the generation of free radical-mediated damage, thus overwhelming the undisputable benefits of regular, medium-intensity physical activity. Since reactive oxygen species are actively generated during high-intensity exercise, and these reactive compounds are known to impact DNA stability, we review here the current evidence about strenuous exercise and DNA injury...
2017: Advances in Clinical Chemistry
https://www.readbyqxmd.com/read/28628631/computational-explanation-for-bioactivation-mechanism-of-targeted-anticancer-agents-mediated-by-cytochrome-p450s-a-case-of-erlotinib
#10
Chun-Zhi Ai, Yong Liu, Wei Li, De-Meng Chen, Xin-Xing Zhu, Ya-Wei Yan, Du-Chu Chen, Yi-Zhou Jiang
EGFR inhibitors, even with therapeutics superiorities in anticancer, can cause idiosyncratic pulmonary and hepatic toxicities that are associated with the reactive electrophile bioactivated by Cytochrome P450s (P450s). Until now, neither has the electrophilic intermediate been caught experimentally, nor has the subtle mechanism been declared. Herein, the underlying mechanism of bioactivation mediated by P450s was explored by DFT calculations for a case of EGFR inhibitor, Erlotinib. Based on the calculation and analysis, we suggest that with other metabolites, reactive electrophiles of Erlotinib: epoxide and quinine-imine, can be generated by several steps along the oxidative reaction pathway...
2017: PloS One
https://www.readbyqxmd.com/read/28628319/on-the-mechanism-of-phenol-alkylation-in-zeolite-h-bea-using-in-situ-solid-state-nmr-spectroscopy
#11
Zhenchao Zhao, Hui Shi, Chuan Wan, Mary Y Hu, Yuanshuai Liu, Donghai Mei, Donald M Camaioni, Jian Zhi Hu, Johannes A Lercher
The reaction mechanism of solid-acid-catalyzed phenol alkylation with cyclohexanol and cyclohexene in the apolar solvent decalin has been studied using in situ (13)C MAS NMR spectroscopy. Phenol alkylation with cyclohexanol sets in only after a majority of cyclohexanol is dehydrated to cyclohexene. As phenol and cyclohexanol show similar adsorption strength, this strict reaction sequence is not caused by the limited access of phenol to cyclohexanol, but is due to the absence of a reactive electrophile as long as a significant fraction of cyclohexanol is present...
June 19, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28627822/development-of-a-one-step-reverse-transcription-loop-mediated-isothermal-amplification-system-for-a-highly-sensitive-detection-of-rabbit-hepatitis-e-virus
#12
Jing Wang, Hua Zhang, Shengyuan Yan, Yichao Wang, Xin Lu, Hongwei Fu
BACKGROUND: Hepatitis E virus (HEV) is a major cause of acute viral hepatitis in areas with poor sanitation. Rabbit is one of important animal reservoirs of the virus. Reverse transcription-loop-mediated isothermal amplification (RT-LAMP) system is a novel nucleic acid amplification assay, for which the specificity and sensitivity are much higher than that of conventional PCR. However, previously reported RT-LAMP system cannot detect rabbit HEV, which was identified recently and seems to be another potential source of human HEV infection...
May 1, 2017: Clinical Laboratory
https://www.readbyqxmd.com/read/28627365/mitochondria-metabolic-reprogramming-in-the-formation-of-neurons-from-peripheral-cells-cause-or-consequence-and-the-implications-to-their-utility
#13
REVIEW
Gary E Gibson, Ankita Thakkar
The induction of pluripotent stem cells (iPSC) from differentiated cells such as fibroblasts and their subsequent conversion to neural progenitor cells (NPC) and finally to neurons is intriguing scientifically, and its potential to medicine nearly infinite, but unrealized. A better understanding of the changes at each step of the transformation will enable investigators to use them better to model neurological disease. Each step of conversion from a differentiated cell to an iPSC to a NPC to neurons requires large changes in glycolysis including aerobic glycolysis, the pentose shunt, the tricarboxylic acid cycle, the electron transport chain and in the production of reactive oxygen species (ROS)...
June 13, 2017: Neurochemistry International
https://www.readbyqxmd.com/read/28627040/a-facile-approach-toward-scalable-fabrication-of-reversible-shape-memory-polymers-with-bonded-elastomer-microphases-as-internal-stress-provider
#14
Long Fei Fan, Min Zhi Rong, Ming Qiu Zhang, Xu Dong Chen
The present communication reports a novel strategy to fabricate reversible shape-memory polymer that operates without the aid of external force on the basis of a two-phase structure design. The proof-of-concept material, crosslinked styrene-butadiene-styrene block copolymer (SBS, dispersed phase)/polycaprolactone-based polyurethane (PU, continuous phase) blend, possesses a closely connected microphase separation structure. That is, SBS phases are chemically bonded to crosslinked PU by means of a single crosslinking agent and two-step crosslinking process for increasing integrity of the system...
June 19, 2017: Macromolecular Rapid Communications
https://www.readbyqxmd.com/read/28623834/nitrate-formation-during-ozonation-as-a-surrogate-parameter-for-abatement-of-micropollutants-and-the-n-nitrosodimethylamine-ndma-formation-potential
#15
Yang Song, Florian Breider, Jun Ma, Urs von Gunten
In this study, nitrate formation from ammonium and/or dissolved organic nitrogen (DON) was investigated as a novel surrogate parameter to evaluate the abatement of micropollutants during ozonation of synthetic waters containing natural organic matter (NOM) isolates, a natural water and secondary wastewater effluents. Nitrate formation during ozonation was compared to the changes in UV absorbance at 254 nm (UVA254) including the effect of pH. For low specific ozone doses UVA254 was abated more efficiently than nitrate was formed...
June 1, 2017: Water Research
https://www.readbyqxmd.com/read/28623401/biomarkers-in-the-assessment-of-oral-mucositis-in-head-and-neck-cancer-patients-a-systematic-review-and-meta-analysis
#16
REVIEW
Ana Gabriela Costa Normando, Camila Lopes Rocha, Isabela Porto de Toledo, Paulo Tadeu de Souza Figueiredo, Paula Elaine Diniz Dos Reis, Graziela De Luca Canto, Eliete Neves Silva Guerra
PURPOSE: The aim of this study was to evaluate the capability of biomarkers to predict the risk of oral mucositis in head and neck cancer patients, as well as to assess the correlation between these biomarkers and the severity of mucositis. METHODS: The search was performed at LILACS, PubMed, Science Direct, Scopus, and Web of Science. A search of the gray literature was performed on Google Scholar, OpenGrey, and ProQuest. The methodological quality of the included studies was assessed using the Meta-Analysis of Statistics Assessment and Review Instrument (MAStARI) tool, and the evidence quality was assessed by the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) system...
June 16, 2017: Supportive Care in Cancer: Official Journal of the Multinational Association of Supportive Care in Cancer
https://www.readbyqxmd.com/read/28623283/dosage-compensation-in-the-process-of-inactivation-reactivation-during-both-germ-cell-development-and-early-embryogenesis-in-mouse
#17
Xiaoyong Li, Zhiqiang Hu, Xuelin Yu, Chen Zhang, Binbin Ma, Lin He, Chaochun Wei, Ji Wu
Ohno proposed that dosage compensation in mammals evolved as a two-step mechanism involving X-inactivation and X-upregulation. While X-inactivation is well characterized, it remains to further analysis whether upregulation of the single activated X chromosome in mammals occurs. We obtained RNA-seq data, including single-cell RNA-seq data, from cells undergoing inactivation/reactivation in both germ cell development and early embryogenesis stages in mouse and calculated the X: A ratio from the gene expression...
June 16, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28621793/kinetics-and-mechanism-of-oxidation-of-the-anti-tubercular-prodrug-isoniazid-and-its-analog-by-iridium-iv-as-models-for-biological-redox-systems
#18
Jingran Dong, Yanli Ren, Sufang Sun, Jiao Yang, Chunxia Nan, Hongmei Shi, Jianzhong Xu, Jie Duan, Tiesheng Shi, Lars I Elding
A complex reaction mechanism of oxidation of the anti-tubercular prodrug isoniazid (isonicotinic hydrazide, INH) by [IrCl6](2-) as a model for redox processes of such drugs in biological systems has been studied in aqueous solution as a function of pH between 0 and 8.5. Similar experiments have been performed with its isomer nicotinic hydrazide (NH). All reactions are overall second-order, first-order in [IrCl6](2-) and hydrazide, and the observed second-order rate constants k' have been determined as a function of pH...
June 16, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28620178/collision-induced-activation-towards-industrially-scalable-approach-to-graphite-nanoplatelets-functionalization-for-superior-polymer-nanocomposites
#19
Omid Zabihi, Mojtaba Ahmadi, Tahereh Abdollahi, Saeid Nikafshar, Minoo Naebe
Scale-up manufacturing of engineered graphene-like nanomaterials to deliver the industry needs for development of high-performance polymer nanocomposites still remains a challenge. Herein, we introduce a quick and cost-effective approach to scalable production of functionalized graphite nanoplatelets using "kitchen blender" approach and Diels-Alder chemistry. We have shown that, in a solvent-free process and through a cycloaddition mechanism, maleic anhydride can be grafted onto the edge-localized electron rich active sites of graphite nanoplatelets (GNP) resulting from high collision force, called "graphite collision-induced activation"...
June 15, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28617135/influence-of-personalized-exercise-recommendations-during-rehabilitation-on-the-sustainability-of-objectively-measured-physical-activity-levels-fatigue-and-fatigue-related-biomarkers-in-patients-with-breast-cancer
#20
Philipp Zimmer, Freerk T Baumann, Max Oberste, Joachim Schmitt, Niklas Joisten, Philipp Hartig, Alexander Schenk, Rafaela Kuhn, Wilhelm Bloch, Monika Reuss-Borst
PURPOSE: Only one-third of patients with breast cancer reach the recommended activity level of 15 to 25 MET h/wk. The aim of this study was to determine the influence of personalized exercise recommendations during rehabilitation on patients' physical activity level, fatigue, and self-perceived cognitive function as well as on side effect-associated biomarkers. METHODS: Total metabolic rate, physical activity level, mean MET and steps, fatigue, self-perceived cognitive functioning , and biomarkers (C-reactive protein [CRP], interleukin 6, macrophage migration inhibiting factor [MIF], tumor necrosis factor [TNF]-α, brain-derived neurotrophic factor [BDNF], insulin-like growth factor 1 [IGF1]) were assessed in 60 patients with breast cancer in the aftercare phase before ( t0) and 8 months after ( t1) the intervention...
June 1, 2017: Integrative Cancer Therapies
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