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Penghui Du, He Zhao, Chenming Liu, Qingguo Huang, Hongbin Cao
The transformation of captopril (CAP), a widely-used thiol drug, was studied with the presence of dissolved model humic constituents (HCs) in a laccase-catalyzed system. Reaction products were analyzed by ultra-performance liquid chromatography coupled to time-of-flight mass spectrometry and condensed fukui function computation. CAP reacted with different model HCs in the enzymatic system for 1 h, ranging from 75% (syringic acid) to 96% (p-coumaric acid). In the absence of HCs, only 15% of CAP was removed through self-coupling...
October 14, 2016: Water Research
Andriy Bilichak, Igor Kovalchuk
DNA methylation is a heritable but reversible epigenetic mechanism of control over gene expression. The level of DNA methylation of specific genomic regions correlates with chromatin condensation, the level of gene expression, and in some cases genome stability and the frequency of homologous recombination. Here, we describe the combined bisulfite restriction analysis (COBRA) assay that allows analyzing the methylation status at a specific locus. The protocol consists of the following major steps: bisulfite conversion of non-methylated cytosines to uracils, the locus-specific PCR amplification of converted DNA, restriction digestion, the analysis of restriction patterns on the gel, and the quantification of these restriction patterns using ImageJ or a similar program...
2017: Methods in Molecular Biology
Stefan Grob, Ueli Grossniklaus
Nuclear organization and higher-order chromosome structure in interphase nuclei are thought to have important effects on fundamental biological processes, including chromosome condensation, replication, and transcription. Until recently, however, nuclear organization could only be analyzed microscopically. The development of chromatin conformation capture (3C)-based techniques now allows a detailed look at chromosomal architecture from the level of individual loci to the entire genome. Here we provide a robust Hi-C protocol, allowing the analysis of nuclear organization in nuclei from different wild-type and mutant plant tissues...
2017: Methods in Molecular Biology
Gabor Nagy, Viktoria Baksa, Alexandra Kiss, Melinda Turani, Gaspar Banfalvi
The toxicity of gadolinium is reduced by chelating agents that render this heavy metal into contrast complexes used for medical magnetic resonance imaging. However, the dissociation of gadolinium chelates is known to generate Gd(3+) ions, the cellular toxicity of which has not been tested in details. The cytotoxic effects of Gd(III) ions were evaluated by monitoring the proliferation, measuring the cellular motility and following chromatin changes in various cell lines upon Gd(3+) treatment. Measurements applied long-term scanning microscopy and a perfusion platform that replaced the medium with test solutions, bypassed physical contact with the cell culture during experiments, and provided uninterrupted high time-resolution time-lapse photomicrography for an extended period of time...
October 22, 2016: Apoptosis: An International Journal on Programmed Cell Death
Anurati Saha, Rebecca Rolfe, Simon Carroll, Daniel J Kelly, Paula Murphy
Chondrogenesis in vivo is precisely controlled in time and space. The entire limb skeleton forms from cells at the core of the early limb bud that condense and undergo chondrogenic differentiation. Whether they form stable cartilage at the articular surface of the joint or transient cartilage that progresses to hypertrophy as endochondral bone, replacing the cartilage template of the skeletal rudiment, is spatially controlled over several days in the embryo. Here, we follow the differentiation of cells taken from the early limb bud (embryonic day 11...
October 22, 2016: Cell and Tissue Research
Susumu Ishiguro, Nabil A Alhakamy, Deepthi Uppalapati, Jennifer Delzeit, Cory J Berkland, Masaaki Tamura
To evaluate the potential of cell-penetrating peptide-based delivery of apoptosis-inducer gene in cancer therapy, a modified HIV-1 TAT peptide (dimerized TAT peptide, dTAT) was studied. The dTAT and plasmid DNA (pDNA) complexes (dTAT-pDNA) were condensed using calcium chloride (dTAT-pDNA-Ca(2+)). This simple nonviral formulation approach showed high levels of gene expression in vitro without any cytotoxicity. In mouse studies, a single intratracheal (IT) aerosol spray or 2 intravenous (IV) injections of the dTAT, apoptosis-inducer gene, angiotensin II type 2 receptor (AT2R), and Ca(2+) complexes (dTAT-pAT2R-Ca(2+)) significantly attenuated the acutely growing mouse Lewis lung carcinoma allografts in mouse lungs...
October 18, 2016: Journal of Pharmaceutical Sciences
Qin Wang, Hongjun Chen, Yong Li, Huixia Wang, Zhou Nie, Yufang Hu, Shouzhou Yao
We report here a label-free and sensitive electrochemical method for probing Citrate synthase (CS) activity based on detailed investigations into the nucleic acid-mimicking coordination polymer (CP) formed from the coenzyme A (CoA)-Ag(I) repeat units. Our biosensing approach provides an especial and significant detection mechanism: CS can catalyze the essential condensation reaction between acetyl-coenzyme A (Ac-CoA) and oxaloacetate (OAA) to form citrate and CoA; then, in the presence of Ag(I), CoA-Ag(I) CP can be in situ formed because of the strong complexation ability of thiol groups of CoA toward Ag(I)...
December 1, 2016: Talanta
María Asunción López-Bascón, Mónica Calderón-Santiago, Feliciano Priego-Capote
A novel class of endogenous mammalian lipids endowed with antidiabetic and anti-inflammatory properties has been recently discovered. These are fatty acid esters of hydroxy fatty acids (FAHFAs) formed by condensation between a hydroxy fatty acid and a fatty acid. FAHFAs are present in human serum and tissues at low nanomolar concentrations. Therefore, high sensitivity and selectivity profiling analysis of these compounds in clinical samples is demanded. An automated qualitative and quantitative method based on on-line coupling between solid phase extraction and liquid chromatography-tandem mass spectrometry has been here developed for determination of FAHFAs in serum with the required sensitivity and selectivity...
November 2, 2016: Analytica Chimica Acta
Emilia Fisicaro, Carlotta Compari, Franco Bacciottini, Laura Contardi, Erika Pongiluppi, Nadia Barbero, Guido Viscardi, Pierluigi Quagliotto, Gaetano Donofrio, Marie Pierre Krafft
Biological and thermodynamic properties of a new homologous series of highly fluorinated bispyridinium cationic gemini surfactants, differing in the length of the spacer bridging the pyridinium polar heads in 1,1' position, are reported for the first time. Interestingly, gene delivery ability is closely associated with the spacer length due to a structural change of the molecule in solution. This conformation change is allowed when the spacer reaches the right length, and it is suggested by the trends of the apparent and partial molar enthalpies vs molality...
October 15, 2016: Journal of Colloid and Interface Science
David A Mazziotti
A central challenge of physics is the computation of strongly correlated quantum systems. The past ten years have witnessed the development and application of the variational calculation of the two-electron reduced density matrix (2-RDM) without the wave function. In this Letter we present an orders-of-magnitude improvement in the accuracy of 2-RDM calculations without an increase in their computational cost. The advance is based on a low-rank, dual formulation of an important constraint on the 2-RDM, the T2 condition...
October 7, 2016: Physical Review Letters
Xiaodong Tang, Jidan Yang, Zhongzhi Zhu, Meifang Zheng, Wanqing Wu, Huanfeng Jiang
A new strategy for thiazoles via copper-catalyzed [3+1+1]-type condensation reaction from oximes, anhydrides and potassiumthiocyanate (KSCN) is developed herein. The transformation has good functional group tolerance and various thiazoles were formed smoothly in good to excellent yields under mild reaction conditions. This process involves copper-catalyzed N-O/C-S bond cleavages, activation of vinyl sp2 C-H bond and C-S/C-N bond formations which is under redox-neutral conditions well as operational simplicity...
October 21, 2016: Journal of Organic Chemistry
Giulia Tuci, Lapo Luconi, Andrea Rossin, Enrico Berretti, Housseinou Ba, Massimo Innocenti, Dmitry Yakhvarov, Stefano Caporali, Cuong Pham-Huu, Giuliano Giambastiani
This paper describes the exohedral N-decoration of multi-walled carbon nanotubes (MWCNTs) with NH-aziridine groups via [2+1] cycloaddition of a tert-butyl-oxycarbonyl nitrene followed by controlled thermal decomposition of the cyclization product. The chemical grafting with N-containing groups deeply modifies the properties of the starting MWCNTs, generating new surface microenvironments with specific base (Brønsted) and electronic properties. Both these features translate into a highly versatile single-phase heterogeneous catalyst (MW@NAz) with remarkable chemical and electrochemical performance...
October 21, 2016: ACS Applied Materials & Interfaces
Atsushi Umehara, Hirofumi Ueda, Hidetoshi Tokuyama
A novel condensation reaction of carboxylic acids with various non-nucleophilic N-heterocycles and anilides was developed. The reaction proceeds in the presence of di-tert-butyl dicarbonate (Boc2O), catalytic 4-(dimethylamino)pyridine (DMAP), and 2,6-lutidine and is applicable to the acylation of a wide range of non-nucleophilic nitrogen compounds, including indoles, pyrroles, pyrazole, carbazole, lactams, oxazolidinones, and anilides with high functional group compatibility. The scope of indoles, carboxylic acids, and anilides was also studied...
October 21, 2016: Journal of Organic Chemistry
Deepak Adhikari, Kiran Busayavalasa, Jingjing Zhang, Mengwen Hu, Sanjiv Risal, Mustafa Bilal Bayazit, Meenakshi Singh, M Kasim Diril, Philipp Kaldis, Kui Liu
A unique feature of female germ cell development in mammals is their remarkably long arrest at the prophase of meiosis I, which lasts up to 50 years in humans. Both dormant and growing oocytes are arrested at prophase I and completely lack the ability to resume meiosis. Here, we show that the prolonged meiotic arrest of female germ cells is largely achieved via the inhibitory phosphorylation of Cdk1 (cyclin-dependent kinase 1). In two mouse models where we have introduced mutant Cdk1(T14AY15F) which cannot be inhibited by phosphorylation (Cdk1AF) in small meiotically incompetent oocytes, the prophase I arrest is interrupted, leading to a premature loss of female germ cells...
October 21, 2016: Cell Research
Jin Li, Qian Zhang, Jian Yin, Changjiang Yu, Kai Cheng, Yun Wei, Erhong Hao, Lijuan Jiao
Prodiginines, as a family of bacterial alkaloids, possess a number of interesting biological activities. New, concise synthetic routes for the facile preparation of both synthetic and natural prodiginines in good yields have been developed, which use BODIPY functionalization reactions, such as condensation, nucleophilic substitution, and BF2 deprotection. This new metal-free synthetic method opens the door toward a wide variety of C-ring functionalized prodiginines, including those that are not possible to obtain through current synthetic methods, for their advanced biological activities...
October 21, 2016: Organic Letters
Floriana Foarta, Clark R Landis
A novel strategy, free of coupling reagents and protection/deprotection steps, for the synthesis of oligo(2-hydroxyacid)s containing up to four monomer units with atom economy, sequence specificity, and control of stereocenter configuration is described. The strategy comprises an iterative application of the sequence asymmetric hydroformylation / oxidation / alkyne hydroacyloxylation that features catalytic, atom-economical C-C and C-O bond forming reactions. Asymmetric hydroformylation with Rh-bisdiazaphospholane catalyst introduces each stereocenter with high enantio- (ca...
October 21, 2016: Journal of Organic Chemistry
Alfio Torrisi, Przemyslaw Wachulak, Łukasz Węgrzyński, Tomasz Fok, Andrzej Bartnik, Tomáš Parkman, Šárka Vondrová, Jana Turňová, Bartłomiej J Jankiewicz, Bartosz Bartosewicz, Henryk Fiedorowicz
We report on a very compact desk-top transmission extreme ultraviolet (EUV) microscope based on a laser-plasma source with a double stream gas-puff target, capable of acquiring magnified images of objects with a spatial (half-pitch) resolution of sub-50 nm. A multilayer ellipsoidal condenser is used to focus and spectrally narrow the radiation from the plasma, producing a quasi-monochromatic EUV radiation (λ = 13.8 nm) illuminating the object, whereas a Fresnel zone plate objective forms the image. Design details, development, characterization and optimization of the EUV source and the microscope are described and discussed...
October 21, 2016: Journal of Microscopy
Jérémie Grolleau, Frédéric Gohier, Clément Cabanetos, Magali Allain, Stéphanie Legoupy, Pierre Frère
Synthetic access to new push-pull molecules based on 3-cyano-4-hexyloxythiophene and triphenylamine moieties is presented herein using a clean methodology. The key step involves a direct heteroarylation coupling reaction in the presence of a homogeneous or heterogeneous [Pd] catalyst followed by Knoevenagel condensation performed in ethanol as a solvent. Structure-electronic property relationships of the new molecular materials are discussed and then their use as donors in bilayer planar heterojunction solar cells is investigated...
October 21, 2016: Organic & Biomolecular Chemistry
Song-Lin Zhang, Ze-Long Yu
Divergent synthesis of indoles, oxindoles, isocoumarins and isoquinolinones is described in this report by using a general Pd-catalyzed tandem reaction of β-hydroxy carbonyl compounds with aryl halides bearing an ortho-nitro, -ester or -cyano substituent. A key retro-aldol/α-arylation reaction is involved that merges classic Pd cross-coupling chemistry with novel Pd-promoted retro-aldol C-C activation to produce α-arylated ketones or esters. Subsequent intramolecular condensation of the carbonyl with the ortho-synthon gives target heterocycles...
October 21, 2016: Organic & Biomolecular Chemistry
Abolfazl Aslani, Behzad Zolfaghari, Fatemeh Davoodvandi
Purpose: Recurrent aphthous stomatitis is a disease with unknown etiology that's mostly treated symptomatically and has no definite cure. Pomegranate (Punica granatum) flowers have been used as medicinal herb that due to its antimicrobial, antioxidant, anti-inflammatory, analgesic and healing effects, has been useful in treatment of oral aphthous. Therefore, we decided to formulate a mucoadhesive gel with pomegranate flower extract to reduce the need for corticosteroid therapy in patients. Methods: Pomegranate flowers are extracted by percolation method...
September 2016: Advanced Pharmaceutical Bulletin
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