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https://www.readbyqxmd.com/read/29679114/online-screening-of-%C3%AE-amylase-inhibitors-by-capillary-electrophoresis
#1
Ondřej Hodek, Tomáš Křížek, Pavel Coufal, Helena Ryšlavá
Pancreatic α-amylase plays an important role in dietary starch hydrolysis in the small intestine and participates in enhanced glucose concentration after meals. It seems to be a problem for diabetic patients, who suffer from longer postprandial hyperglycemia after meal consumption than healthy people. There are commercially available drugs that inhibit α-amylase and thus reduce the postprandial hyperglycemia effect. However, these drugs may cause severe side effects. Conversely, some naturally occurring flavonoids were suggested to have an α-amylase-inhibiting effect without any side effects...
April 20, 2018: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/29678198/metabolic-retroconversion-of-trimethylamine-n-oxide-and-the-gut-microbiota
#2
Lesley Hoyles, Maria L Jiménez-Pranteda, Julien Chilloux, Francois Brial, Antonis Myridakis, Thomas Aranias, Christophe Magnan, Glenn R Gibson, Jeremy D Sanderson, Jeremy K Nicholson, Dominique Gauguier, Anne L McCartney, Marc-Emmanuel Dumas
BACKGROUND: The dietary methylamines choline, carnitine, and phosphatidylcholine are used by the gut microbiota to produce a range of metabolites, including trimethylamine (TMA). However, little is known about the use of trimethylamine N-oxide (TMAO) by this consortium of microbes. RESULTS: A feeding study using deuterated TMAO in C57BL6/J mice demonstrated microbial conversion of TMAO to TMA, with uptake of TMA into the bloodstream and its conversion to TMAO. Microbial activity necessary to convert TMAO to TMA was suppressed in antibiotic-treated mice, with deuterated TMAO being taken up directly into the bloodstream...
April 20, 2018: Microbiome
https://www.readbyqxmd.com/read/29678114/vertical-stratification-engineering-for-organic-bulk-heterojunction-devices
#3
Liqiang Huang, Gang Wang, Weihua Zhou, Boyi Fu, Xiaofang Cheng, Lifu Zhang, Zhibo Yuan, Sixing Xiong, Lin Zhang, Yuanpeng Xie, Andong Zhang, Youdi Zhang, Wei Ma, Weiwei Li, Yinhua Zhou, Elsa Reichmanis, Yiwang Chen
High efficiency organic solar cells (OSCs) can be produced through optimization of component molecular design, coupled with interfacial engineering and control of active layer morphology. However, vertical stratification of the bulk-heterojunction (BHJ), a spontaneous activity which occurs during the drying process, remains an intricate problem yet to be solved. Routes toward regulating the vertical separation profile and evaluating the effects on the final device should be explored to further enhance the performance of OSCs...
April 20, 2018: ACS Nano
https://www.readbyqxmd.com/read/29677127/direct-hetero-arylation-polymerization-of-a-spirobifluorene-and-a-dithienyl-diketopyrrolopyrrole-derivative-new-donor-polymers-for-organic-solar-cells
#4
Pierre Josse, Sergey Dayneko, Yangqian Zhang, Sylvie Dabos-Seignon, Shiming Zhang, Philippe Blanchard, Gregory C Welch, Clément Cabanetos
The synthesis and preliminary evaluation as donor material for organic photovoltaics of the poly(diketopyrrolopyrrole-spirobifluorene) ( PDPPSBF ) is reported herein. Prepared via homogeneous and heterogeneous direct (hetero)arylation polymerization (DHAP), through the use of different catalytic systems, conjugated polymers with comparable molecular weights were obtained. The polymers exhibited strong optical absorption out to 700 nm as thin-films and had appropriate electronic energy levels for use as a donor with PC70 BM ...
April 20, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29676920/aliphatic-c-h-bond-oxidation-with-hydrogen-peroxide-catalyzed-by-manganese-complexes-directing-selectivity-through-torsional-effects
#5
Michela Milan, Massimo Bietti, Miquel Costas
Substituted N-cyclohexyl amides undergo aliphatic C-H bond oxidation with H2 O2 catalyzed by manganese complexes. The reactions are directed by torsional effects leading to site-selective oxidation of cis-1,4-, trans-1,3-, and cis-1,2-cyclohexanediamides. The corresponding diastereoisomers are unreactive under the same conditions. Competitive oxidation of cis- trans mixtures of 4-substituted N-cyclohexylamides leads to quantitative conversion of the cis-isomers, allowing isolation and successive conversion of the trans-isomers into densely functionalized oxidation products with excellent site selectivity and good enantioselectivity...
April 20, 2018: Organic Letters
https://www.readbyqxmd.com/read/29675663/origins-of-metaplasia-in-barrett-s-esophagus-is-this-an-esophageal-stem-or-progenitor-cell-disease
#6
REVIEW
Wei Zhang, David H Wang
The incidence of esophageal adenocarcinoma has been increasing in Western countries over the past several decades. Though Barrett's esophagus, in which the normal esophageal squamous epithelium is replaced with metaplastic intestinalized columnar cells due to chronic damage from gastroesophageal reflux, is accepted as the requisite precursor lesion for esophageal adenocarcinoma, the Barrett's esophagus cell of origin and the molecular mechanism underlying esophageal epithelial metaplasia remain controversial...
April 19, 2018: Digestive Diseases and Sciences
https://www.readbyqxmd.com/read/29675406/bio-oil-hydrotreatment-for-enhancing-solubility-in-biodiesel-and-the-oxydation-stability-of-resulting-blends
#7
Lucía Botella, Filip Stankovikj, José L Sánchez, Alberto Gonzalo, Jesús Arauzo, Manuel Garcia-Pérez
The major challenge for the pyrolytic conversion of lignocellulosic materials into crude bio-oil is the poor quality of the final product. Several strategies (addition of solvents, production of emulsions, and extraction with biodiesel) have been studied to improve its fuel properties. The extraction with biodiesel is an interesting solution because it allows direct utilization of some bio-oil fractions as fuels. However, fraction extracted with biodiesel is typically between 10 and 18 wt. %. In this paper we studied mild hydrotreatment of pyrolysis oil to enhance its solubility in biodiesel...
2018: Frontiers in Chemistry
https://www.readbyqxmd.com/read/29675225/a-new-twist-in-the-photophysics-of-the-gfp-chromophore-a-volume-conserving-molecular-torsion-couple
#8
Jamie Conyard, Ismael A Heisler, Yohan Chan, Philip C Bulman Page, Stephen R Meech, Lluís Blancafort
The simple structure of the chromophore of the green fluorescent protein (GFP), a phenol and an imidazolone ring linked by a methyne bridge, supports an exceptionally diverse range of excited state phenomena. Here we describe experimentally and theoretically the photochemistry of a novel sterically crowded nonplanar derivative of the GFP chromophore. It undergoes an excited state isomerization reaction accompanied by an exceptionally fast (sub 100 fs) excited state decay. The decay dynamics are essentially independent of solvent polarity and viscosity...
February 21, 2018: Chemical Science
https://www.readbyqxmd.com/read/29675152/binding-of-anions-in-triply-interlocked-coordination-catenanes-and-dynamic-allostery-for-dehalogenation-reactions
#9
Linlin Yang, Xu Jing, Bowen An, Cheng He, Yang Yang, Chunying Duan
By synergistic combination of multicomponent self-assembly and template-directed approaches, triply interlocked metal organic catenanes that consist of two isolated chirally identical tetrahedrons were constructed and stabilized as thermodynamic minima. In the presence of suitable template anions, the structural conversion from the isolated tetrahedral conformers into locked catenanes occurred via the cleavage of an intrinsically reversible coordination bond in each of the tetrahedrons, followed by the reengineering and interlocking of two fragments with the regeneration of the broken coordination bonds...
January 28, 2018: Chemical Science
https://www.readbyqxmd.com/read/29674454/control-of-vacuole-membrane-homeostasis-by-a-resident-pi-3-5-kinase-inhibitor
#10
P C Malia, Johannes Numrich, Taki Nishimura, Ayelén González Montoro, Christopher J Stefan, Christian Ungermann
Lysosomes have an important role in cellular protein and organelle quality control, metabolism, and signaling. On the surface of lysosomes, the PIKfyve/Fab1 complex generates phosphatidylinositol 3,5-bisphosphate, PI-3,5-P2 , which is critical for lysosomal membrane homeostasis during acute osmotic stress and for lysosomal signaling. Here, we identify the inverted BAR protein Ivy1 as an inhibitor of the Fab1 complex with a direct influence on PI-3,5-P2 levels and vacuole homeostasis. Ivy1 requires Ypt7 binding for its function, binds PI-3,5-P2 , and interacts with the Fab1 kinase...
April 19, 2018: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/29673207/direct-hetero-arylation-for-the-synthesis-of-molecular-materials-coupling-thieno-3-4-c-pyrrole-4-6-dione-with-perylene-diimide-to-yield-novel-non-fullerene-acceptors-for-organic-solar-cells
#11
Thomas A Welsh, Audrey Laventure, Gregory C Welch
Herein we report on the synthesis of an N -annulated perylene diimide (PDI) disubstituted thieno[3,4-c]pyrrole-4,6-dione (TPD) molecular acceptor (PDI-TPD-PDI) by direct heteroarylation (DHA) methods. Three sets of DHA conditions that explore the effects of solvent, temperature, and catalyst were employed to find the optimal conditions for the synthesis of two PDI-TPD-PDI derivatives. We then selected one PDI-TPD-PDI for use as a non-fullerene acceptor in organic solar cell devices with the donor polymer PBDB-T...
April 17, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/29672922/myocardial-perfusion-quantification-using-simultaneously-acquired-13-nh-3-ammonia-pet-and-dynamic-contrast-enhanced-mri-in-patients-at-rest-and-stress
#12
Karl P Kunze, Stephan G Nekolla, Christoph Rischpler, Shelley HuaLei Zhang, Carmel Hayes, Nicolas Langwieser, Tareq Ibrahim, Karl-Ludwig Laugwitz, Markus Schwaiger
PURPOSE: Systematic differences with respect to myocardial perfusion quantification exist between DCE-MRI and PET. Using the potential of integrated PET/MRI, this study was conceived to compare perfusion quantification on the basis of simultaneously acquired 13 NH3 -ammonia PET and DCE-MRI data in patients at rest and stress. METHODS: Twenty-nine patients were examined on a 3T PET/MRI scanner. DCE-MRI was implemented in dual-sequence design and additional T1 mapping for signal normalization...
April 19, 2018: Magnetic Resonance in Medicine: Official Journal of the Society of Magnetic Resonance in Medicine
https://www.readbyqxmd.com/read/29671569/one-step-facile-synthesis-of-cobalt-phosphides-for-hydrogen-evolution-reaction-catalyst-in-acidic-and-alkaline-medium
#13
Afriyanti Sumboja, Tao An, Hai Yang Goh, Mechthild Lübke, Dougal Peter Howard, Yijie Xu, Albertus Denny Handoko, Yun Zong, Zhaolin Liu
Catalysts for hydrogen evolution reaction (HER) are in demand to realize the efficient conversion of hydrogen via water electrolysis. In this work, cobalt phosphides were prepared using a one-step, scalable and direct gas-solid phosphidation of commercially available cobalt salts. It was found that the effectiveness of the phosphidation reaction was closely related to the state of cobalt precursors at the reaction temperature. For instance, high yield of cobalt phosphides obtained from the phosphidation of cobalt (II) acetate was related to the good stability of cobalt salt at the phosphidation temperature...
April 19, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29670923/cathelicidin-ll-37-affects-surface-and-intracellular-toll-like-receptor-expression-in-tissue-mast-cells
#14
Justyna Agier, Ewa Brzezińska-Błaszczyk, Paulina Żelechowska, Magdalena Wiktorska, Jacek Pietrzak, Sylwia Różalska
Undoubtedly, mast cells take part in host defense against microorganisms as they are numerous at the portal of infection, they release many proinflammatory and antimicrobial mediators, and they express pattern recognition receptors, such as TLRs. These receptors play a key role in recognition and binding molecules associated with microorganisms and molecules associated with damage. Cathelicidins exhibit direct antimicrobial activities against a broad spectrum of microbes by perturbing their cell membranes. Accumulating evidence suggests a role for these molecules in supporting cell activation...
2018: Journal of Immunology Research
https://www.readbyqxmd.com/read/29670818/fingolimod-promotes-blood-nerve-barrier-properties-in-vitro
#15
Hideaki Nishihara, Toshihiko Maeda, Yasuteru Sano, Maho Ueno, Nana Okamoto, Yukio Takeshita, Fumitaka Shimizu, Michiaki Koga, Takashi Kanda
Objective: The main effect of fingolimod is thought to be functional antagonism of lymphocytic S1P1 receptors and the prevention of lymphocyte egress from lymphoid tissues, thereby reducing lymphocyte infiltration into the nervous system. However, a growing number of reports suggest that fingolimod also has a direct effect on several cell types in the nervous system. Although we previously reported that fingolimod enhances blood-brain barrier (BBB) functions, there have been no investigations regarding the blood-nerve barrier (BNB)...
April 2018: Brain and Behavior
https://www.readbyqxmd.com/read/29670217/bacterial-derived-exopolysaccharides-enhance-antifungal-drug-tolerance-in-a-cross-kingdom-oral-biofilm
#16
Dongyeop Kim, Yuan Liu, Raphael I Benhamou, Hiram Sanchez, Áurea Simón-Soro, Yong Li, Geelsu Hwang, Micha Fridman, David R Andes, Hyun Koo
Fungal-bacterial interactions generate unique biofilms that cause many infections in humans. Candida albicans interact with Streptococcus mutans in dental biofilms associated with severe childhood tooth-decay, a prevalent pediatric oral disease. Current modalities are ineffective and primarily based on antimicrobial monotherapies despite the polymicrobial nature of the infection. Here, we show that the combination of clinically used topical antifungal fluconazole with povidone iodine (PI) can completely suppress C...
April 18, 2018: ISME Journal
https://www.readbyqxmd.com/read/29669808/lactoferrin-is-a-natural-inhibitor-of-plasminogen-activation
#17
Alexander Zwirzitz, Michael Reiter, Rostislav Skrabana, Anna Ohradanova-Repic, Otto Majdic, Marianna Gutekova, Ondrej Cehlar, Eva Petrovčíková, Eva Kutejova, Gerold Stanek, Hannes Stockinger, Vladimir Leksa
The plasminogen system is essential for dissolution of fibrin clots, and in addition, it is involved in a wide variety of other physiological processes, including proteolytic activation of growth factors, cell migration, and removal of protein aggregates. On the other hand, uncontrolled plasminogen activation contributes to many pathological processes, e.g. tumor cells' invasion in cancer progression. Moreover, some virulent bacterial species, e.g. Streptococci or Borrelia, bind human plasminogen and hijack the host's plasminogen system to penetrate tissue barriers...
April 18, 2018: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/29669261/chrebp-deficiency-leads-to-diarrhea-predominant-irritable-bowel-syndrome
#18
Ah-Reum Oh, Seonyong Sohn, Junghoon Lee, Jong-Min Park, Ki Taek Nam, Ki-Baik Hahm, Young-Bum Kim, Ho-Jae Lee, Ji-Young Cha
OBJECTIVE: Fructose malabsorption is a common digestive disorder in which absorption of fructose in the small intestine is impaired. An abnormality of the main intestinal fructose transporter proteins has been proposed as a cause for fructose malabsorption. However the underlying molecular mechanism for this remains unclear. In this study, we investigated whether carbohydrate response element-binding protein (ChREBP) plays a role in intestinal fructose absorption through the regulation of genes involved in fructose transport and metabolism and ion transport...
April 15, 2018: Metabolism: Clinical and Experimental
https://www.readbyqxmd.com/read/29669022/dna-mediated-dimerization-on-a-compact-sequence-signature-controls-enhancer-engagement-and-regulation-by-foxa1
#19
Xuecong Wang, Yogesh Srivastava, Aleksander Jankowski, Vikas Malik, Yuanjie Wei, Ricardo C H Del Rosario, Vlad Cojocaru, Shyam Prabhakar, Ralf Jauch
FOXA1 is a transcription factor capable to bind silenced chromatin to direct context-dependent cell fate conversion. Here, we demonstrate that a compact palindromic DNA element (termed 'DIV' for its diverging half-sites) induces the homodimerization of FOXA1 with strongly positive cooperativity. Alternative structural models are consistent with either an indirect DNA-mediated cooperativity or a direct protein-protein interaction. The cooperative homodimer formation is strictly constrained by precise half-site spacing...
April 14, 2018: Nucleic Acids Research
https://www.readbyqxmd.com/read/29668921/predictors-of-durability-of-radiological-response-in-patients-with-small-bowel-crohn-s-disease
#20
Parakkal Deepak, Joel G Fletcher, Jeff L Fidler, John M Barlow, Shannon P Sheedy, Amy B Kolbe, William S Harmsen, Terry Therneau, Stephanie L Hansel, Brenda D Becker, Edward V Loftus, David H Bruining
Background: The long-term significance of radiological transmural response (TR) as a treatment goal at the first follow-up scan in small bowel Crohn's disease (CD) has been previously shown. We examined the durability of a long-term strategy of treating to a target of radiological TR and the influence of baseline predictors on the maintenance of TR. Methods: Small bowel CD patients between January 1, 2002, and December 31, 2014, were identified with serial computed tomography enterography (CTE)/magnetic resonance enterography (MRE) before and after initiation of therapy or on maintenance therapy...
April 13, 2018: Inflammatory Bowel Diseases
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