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https://www.readbyqxmd.com/read/29217658/nucleic-acid-based-nanotechnology-the-ability-of-dna-and-rna-to-fold-into-precise-and-complex-shapes-can-be-exploited-for-applications-both-in-biology-and-electronics
#1
https://www.readbyqxmd.com/read/29215882/theoretical-models-for-quantitative-description-of-the-acid-base-equilibria-of-the-5-6-substituted-uracils
#2
Margarita G Ilyina, Edward M Khamitov, Sergey Petrovich Ivanov, Akhat G Mustafin, Sergey L Khursan
The acidities of 18 5,6-substituted uracils have been numerically estimated as pKa values in terms of three theoretical models. The first scheme includes the calculation of the gas-phase acidity of uracil with the G3MP2B3 method and taking into account the solvent effect using the polarizable continuum approximation PCM(SMD)-TPSS/aug-cc-pVTZ. The second model is one-step and implies calculating of the free Gibbs energies of the hydrate complex of uracil (and its anion) with 5 water molecules by the TPSS/aug-cc-pVTZ method...
December 7, 2017: Journal of Physical Chemistry. A
https://www.readbyqxmd.com/read/29211866/association-of-urinary-citrate-with-acid-base-status-bone-resorption-and-calcium-excretion-in-older-men-and-women
#3
M Kyla Shea, Bess Dawson-Hughes
Context: Elevated urine net acid excretion (NAE), indicative of subclinical metabolic acidosis, has been associated with higher bone turnover. While NAE is the gold-standard clinical measure of acid-base status, it is impractical to measure in most clinical/research settings. Urine citrate, which is commonly measured, changes in response to acid-base status, but its association with bone turnover is uncertain. Objective: To evaluate the association between change in urine citrate and change in bone turnover and calcium excretion...
December 1, 2017: Journal of Clinical Endocrinology and Metabolism
https://www.readbyqxmd.com/read/29210578/lewis-acid-base-adducts-of-sc2c2-c3v-8-c82-n-heterocyclic-carbene-toward-isomerically-pure-metallofullerene-derivatives
#4
Lipiao Bao, Muqing Chen, Wangqiang Shen, Le Yang, Peng Jin, Xing Lu
The addition of a bulky N-heterocyclic carbene (NHC) to Sc2C2@C3v(8)-C82 affords two monoadducts (2a and 2b) quantitatively and regioselectively, representing the first examples of Lewis acid-base pairs of metal carbide cluster fullerenes. 2b is likely a kinetically favorable labile product that cannot be isolated from the solution. The crystallographic results of 2a unambiguously demonstrate that one polarized C-C single bond is formed between the normal carbene site C2N of the NHC and a specific [5,6,6]-carbon atom out of 17 types of nonequivalent cage carbon atoms of Sc2C2@C3v(8)-C82...
December 6, 2017: Inorganic Chemistry
https://www.readbyqxmd.com/read/29209224/na-h-exchanger-3-is-expressed-in-two-distinct-types-of-ionocyte-and-probably-augments-ammonia-excretion-in-one-of-them-in-the-gills-of-the-climbing-perch-exposed-to-seawater
#5
Xiu L Chen, Biyan Zhang, You R Chng, Jasmine L Y Ong, Shit F Chew, Wai P Wong, Siew H Lam, Yuen K Ip
The freshwater climbing perch, Anabas testudineus, is an euryhaline teleost and an obligate air-breather with the ability to actively excrete ammonia. Members of the Na+/H+ exchanger (NHE) family help maintain intracellular pH homeostasis and ionic balance through the electroneutral exchange of Na+ and H+. This study aimed to obtain, from the gills of A. testudineus, the full cDNA coding sequence of nhe3, and to determine the effects of exposure to seawater or 100 mmol l-1 of NH4Cl in fresh water on its mRNA and protein expression levels...
2017: Frontiers in Physiology
https://www.readbyqxmd.com/read/29206722/rapid-serological-tests-ineffectively-screen-for-hiv-exposure-in-hiv-positive-infants
#6
Brittany Urick, Youyi Fong, Christopher Okiira, Nicolette Nabukeera-Barungi, Denis Nansera, Emmanuel Ochola, Julius Nteziyaremye, Victor Bigira, Isaac Ssewanyana, Peter Olupot-Olupot, Trevor Peter, Anisa Ghadrshenas, Lara Vojnov, Charles Kiyaga
BACKGROUND: Data on the performance and utility of rapid serological tests in infants to determine HIV exposure are unclear and in some instances contradictory. This study sought to understand the performance of rapid serological tests in high HIV burden, high Option B+ coverage settings to be used as an HIV exposure screening tool. METHODS: A total of 3,600 infants up to 24 months of age at four regional hospitals in Uganda were systematically enrolled and tested simultaneously using both HIV rapid serological and nucleic acid-based tests...
November 28, 2017: Journal of Acquired Immune Deficiency Syndromes: JAIDS
https://www.readbyqxmd.com/read/29206038/introducing-the-bipolar-solvent-media-using-aqueous-mixtures-of-amino-acid-anion-based-ionic-liquids
#7
Vijay Beniwal, Anil Kumar
To carry out a chemical reaction between the reactants with largely different polarities it becomes important to have a reaction medium which possesses both the polar and non-polar solvation environments. In an attempt to explore the reaction media with such unique polarity properties, the present study provides a thorough understanding of the bipolar solvent media using the aqueous mixtures of amino-acid anion based ionic liquids. Highly polar behaviour of the binary mixtures used in the study has been ascribed to the pure ionic liquid state...
December 5, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29205917/targeted-in%C3%A2-situ-metatranscriptomics-for-selected-taxa-from-mesophilic-and-thermophilic-biogas-plants
#8
Yvonne Stolze, Andreas Bremges, Irena Maus, Alfred Pühler, Alexander Sczyrba, Andreas Schlüter
Biogas production is performed anaerobically by complex microbial communities with key species driving the process. Hence, analyses of their in situ activities are crucial to understand the process. In a previous study, metagenome sequencing and subsequent genome binning for different production-scale biogas plants (BGPs) resulted in four genome bins of special interest, assigned to the phyla Thermotogae, Fusobacteria, Spirochaetes and Cloacimonetes, respectively, that were genetically analysed. In this study, metatranscriptome sequencing of the same BGP samples was conducted, enabling in situ transcriptional activity determination of these genome bins...
December 4, 2017: Microbial Biotechnology
https://www.readbyqxmd.com/read/29204927/augmented-bioavailability-of-felodipine-through-an-%C3%AE-linolenic-acid-based-microemulsion
#9
Mahendra Singh, Jovita Kanoujia, Poonam Parashar, Malti Arya, Chandra B Tripathi, V R Sinha, Shailendra K Saraf, Shubhini A Saraf
The oral bioavailability of felodipine, a dihydropyridine calcium channel antagonist, is about 15%. This may be due to poor water solubility, and a lower intestinal permeability than a BCS class I drug, and hepatic first-pass metabolism of the drug. Many drugs are unpopular due to solubility issues. The goal of this study was to develop and optimize a felodipine-containing microemulsion to improve the intestinal permeability and bioavailability of the drug. The felodipine microemulsions were developed with the selected components, i...
December 4, 2017: Drug Delivery and Translational Research
https://www.readbyqxmd.com/read/29203957/parabanic-acid-is-the-singlet-oxygen-specific-oxidation-product-of-uric-acid
#10
Sayaka Iida, Yuki Ohkubo, Yorihiro Yamamoto, Akio Fujisawa
Uric acid quenches singlet oxygen physically or reacts with it, but the oxidation product has not been previously characterized. The present study determined that the product is parabanic acid, which was confirmed by LC/TOFMS analysis. Parabanic acid was stable at acidic pH (<5.0), but hydrolyzed to oxaluric acid at neutral or alkaline pH. The total yields of parabanic acid and oxaluric acid based on consumed uric acid were ~100% in clean singlet oxygen production systems such as UVA irradiation of Rose Bengal and thermal decomposition of 3-(1,4-dihydro-1,4-epidioxy-4-methyl-1-naphthyl)propionic acid...
November 2017: Journal of Clinical Biochemistry and Nutrition
https://www.readbyqxmd.com/read/29202705/differences-in-global-gene-expression-in-muscle-tissue-of-nellore-cattle-with-divergent-meat-tenderness
#11
Larissa Fernanda Simielli Fonseca, Daniele Fernanda Jovino Gimenez, Danielly Beraldo Dos Santos Silva, Roger Barthelson, Fernando Baldi, Jesus Aparecido Ferro, Lucia Galvão Albuquerque
BACKGROUND: Meat tenderness is the consumer's most preferred sensory attribute. This trait is affected by a number of factors, including genotype, age, animal sex, and pre- and post-slaughter management. In view of the high percentage of Zebu genes in the Brazilian cattle population, mainly Nellore cattle, the improvement of meat tenderness is important since the increasing proportion of Zebu genes in the population reduces meat tenderness. However, the measurement of this trait is difficult once it can only be made after animal slaughtering...
December 4, 2017: BMC Genomics
https://www.readbyqxmd.com/read/29202458/integrating-light-sheet-imaging-with-virtual-reality-to-recapitulate-developmental-cardiac-mechanics
#12
Yichen Ding, Arash Abiri, Parinaz Abiri, Shuoran Li, Chih-Chiang Chang, Kyung In Baek, Jeffrey J Hsu, Elias Sideris, Yilei Li, Juhyun Lee, Tatiana Segura, Thao P Nguyen, Alexander Bui, René R Sevag Packard, Peng Fei, Tzung K Hsiai
Currently, there is a limited ability to interactively study developmental cardiac mechanics and physiology. We therefore combined light-sheet fluorescence microscopy (LSFM) with virtual reality (VR) to provide a hybrid platform for 3D architecture and time-dependent cardiac contractile function characterization. By taking advantage of the rapid acquisition, high axial resolution, low phototoxicity, and high fidelity in 3D and 4D (3D spatial + 1D time or spectra), this VR-LSFM hybrid methodology enables interactive visualization and quantification otherwise not available by conventional methods, such as routine optical microscopes...
November 16, 2017: JCI Insight
https://www.readbyqxmd.com/read/29201243/on-the-role-of-acidity-in-bulk-and-nanosheet-t-mfi-t-al3-ga3-fe3-b3-zeolites-in-the-methanol-to-hydrocarbons-reaction
#13
Lingqian Meng, Xiaochun Zhu, Brahim Mezari, Robert Pestman, Wannaruedee Wannapakdee, Emiel J M Hensen
The influence of framework substituents (Al3+, Ga3+, Fe3+ and B3+) and morphology (bulk vs. nanometer-sized sheets) of MFI zeolites on the acidity and catalytic performance in the methanol-to-hydrocarbons (MTH) reaction was investigated. The Brønsted acid density and strength decreased in the order Al(OH)Si>Ga(OH)Si>Fe(OH)Si≫B(OH)Si. Pyridine 15N NMR spectra confirmed the differences in the Brønsted and Lewis acid strengths but also provided evidence for site heterogeneity in the Brønsted acid sites...
October 23, 2017: ChemCatChem
https://www.readbyqxmd.com/read/29200300/experimental-and-molecular-modeling-evaluation-of-the-physicochemical-properties-of-proline-based-deep-eutectic-solvents
#14
Adriaan van den Bruinhorst, Theodora Spyriouni, Jörg-Rüdiger Hill, Maaike C Kroon
The liquid range and applicability of deep eutectic solvents (DESs) are determined by their physicochemical properties. In this work, the physicochemical properties of glycolic acid:proline and malic acid:proline were evaluated experimentally and with MD simulations at five different ratios. Both DESs exhibited esterification upon preparation, which affected the viscosity in particular. In order to minimize oligomer formation and water release, three different experimental preparation methods were explored, but none could prevent esterification...
December 4, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/29196602/identification-and-characterization-of-a-core-fucosidase-from-the-bacterium-elizabethkingia-meningoseptica
#15
Tiansheng Li, Mengjie Li, Linlin Hou, Yameng Guo, Lei Wang, Guiqin Sun, Li Chen
All reported α-L-fucosidases catalyze the removal of nonreducing terminal L-fucoses from oligosaccharides or their conjugates, while having no capacity to hydrolyze core fucoses in glycoproteins directly. Here, we identified an α-fucosidase from the bacterium Elizabethkingia meningoseptica with catalytic activity against core α-1,3-fucosylated substrates and named it core fucosidase I (cFase I). Using site-specific mutational analysis, we found that three acidic residues (Asp-242, Glu-302, and Glu-315) in the predicted active pocket are critical for cFase I activity, with Asp-242 and Glu-315 acting as a pair of classic nucleophile and acid/base residues and Glu-302 acting in an as yet undefined role...
December 1, 2017: Journal of Biological Chemistry
https://www.readbyqxmd.com/read/29196502/identifying-the-localization-and-exploring-a-functional-role-for-gprc5c-in-the-kidney
#16
Premraj Rajkumar, Boyoung Cha, Jianyi Yin, Lois J Arend, Teodor G Păunescu, Yoshio Hirabayashi, Mark Donowitz, Jennifer L Pluznick
The investigation of orphan GPCRs (GPRs) has the potential to uncover novel insights into whole animal physiology. In this study, our goal was to determine the renal localization of Gprc5c, a receptor that we previously reported to be highly expressed in murine whole kidney, and to examine physiologic parameters in Gprc5c knockout (KO) mice to gain insight into function. Gprc5c localized to the apical membrane of renal proximal tubules (PTs) in mice, rats, and humans. With the comparison of Gprc5c wild-type (WT) and KO mice, we found that Gprc5c KO mice have altered acid-base homeostasis...
December 1, 2017: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
https://www.readbyqxmd.com/read/29195645/acidity-modes-of-characterization-and-quantification
#17
Klaus Ruthenberg, Hasok Chang
This paper provides an account of early historical developments in the characterization and quantification of acidity, which may be considered preliminary steps leading to the measurement of acidity. In this "pre-history" of acidity measurement, emphasis is laid on the relative independence of the rich empirical knowledge about acids from theories of acidity. Many attempts were made to compare and assess the strengths of various acids, based on concrete laboratory operations. However, at least until the arrival of the pH measure, the quantification attempts failed to produce anything qualifying as a measurement scale of a recognizable type...
October 2017: Studies in History and Philosophy of Science
https://www.readbyqxmd.com/read/29195218/nucleic-acid-based-electrochemical-nanobiosensors
#18
REVIEW
Alireza Abi, Zahra Mohammadpour, Xiaolei Zuo, Afsaneh Safavi
The detection of biomarkers using sensitive and selective analytical devices is critically important for the early stage diagnosis and treatment of diseases. The synergy between the high specificity of nucleic acid recognition units and the great sensitivity of electrochemical signal transductions has already shown promise for the development of efficient biosensing platforms. Yet nucleic-acid based electrochemical biosensors often rely on target amplification strategies (e.g., polymerase chain reactions) to detect analytes at clinically relevant concentration ranges...
November 4, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/29194378/chitosan-nanoparticles-as-a-mucoadhesive-drug-delivery-system-for-ocular-administration
#19
Mariana M Silva, Raquel Calado, Joana Marto, Ana Bettencourt, António J Almeida, Lídia M D Gonçalves
Pharmaceutical approaches based on nanotechnologies and the development of eye drops composed of the mucoadhesive polymers chitosan and hyaluronic acid are emerging strategies for the efficient treatment of ocular diseases. These innovative nanoparticulate systems aim to increase drugs' bioavailability at the ocular surface. For the successful development of these systems, the evaluation of mucoahesiveness (the interaction between the ocular delivery system and mucins present on the eye) is of utmost importance...
December 1, 2017: Marine Drugs
https://www.readbyqxmd.com/read/29189716/recent-advances-in-nucleic-acid-targeting-probes-and-supramolecular-constructs-based-on-pyrene-modified-oligonucleotides
#20
REVIEW
Olga A Krasheninina, Darya S Novopashina, Evgeny K Apartsin, Alya G Venyaminova
In this review, we summarize the recent advances in the use of pyrene-modified oligonucleotides as a platform for functional nucleic acid-based constructs. Pyrene is of special interest for the development of nucleic acid-based tools due to its unique fluorescent properties (sensitivity of fluorescence to the microenvironment, ability to form excimers and exciplexes, long fluorescence lifetime, high quantum yield), ability to intercalate into the nucleic acid duplex, to act as a π-π-stacking (including anchoring) moiety, and others...
November 30, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
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