keyword
MENU ▼
Read by QxMD icon Read
search

"Acid-base"

keyword
https://www.readbyqxmd.com/read/29908607/a-novel-naphthalene-carboxylic-acid-based-ionic-liquid-mixed-disperser-combined-with-ultrasonic-enhanced-in-situ-metathesis-reaction-for-preconcentration-of-triclosan-and-methyltriclosan-in-milk-and-eggs
#1
Xuedong Wang, Mei Wang, Xuran Wang, Liyang Du, Fangyu Chu, Weinan Ding, Haidong Gu, Huili Wang
A microextraction method was developed based on utilization of a novel ionic liquid (IL) [C4 MIM][NCA] as disperser and conventional ILs as extractor (IL-IL-DLLME). This method was integrated with an in-situ metathesis reaction to achieve high extraction efficiency by eliminating the loss of analytes in the discarded disperser after microextraction. Ultrasonic energy was compared to traditional mechanical shaking to accelerate the in-situ metathesis reaction. A 3-min ultrasonic treatment provided similar extraction efficiency as a 120-min mechanical shaking...
October 2018: Ultrasonics Sonochemistry
https://www.readbyqxmd.com/read/29908208/nucleic-acids-binding-strategies-of-small-molecules-lessons-from-alkaloids
#2
Anirban Basu, Gopinatha Suresh Kumar
BACKGROUND: Nucleic acids are now important targets for therapeutic intervention. Alkaloids are an important class of molecules that have myriad therapeutic utility. Isoquinoline and benzophenanthridine alkaloids exhibit multiple pharmacological activities which are often related to their strong nucleic acid binding abilities. Therefore, a review of their interaction aspects with varying nucleic acid structures is essential for rational design and development as therapeutic agents. SCOPE OF THE REVIEW: This work reviews the interaction of various therapeutically important isoquinoline and benzophenanthridine alkaloids with nucleic acids...
June 13, 2018: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29907770/na-hco-3-cotransporter-nbcn1-slc4a7-accelerates-erbb2-induced-breast-cancer-development-and-tumor-growth-in-mice
#3
Soojung Lee, Trine V Axelsen, Nicolai Jessen, Stine F Pedersen, Pernille Vahl, Ebbe Boedtkjer
Metabolic acid production challenges cellular pH homeostasis in solid cancer tissue, and mechanisms of net acid extrusion represent promising new targets for breast cancer therapy. Here, we used genetically engineered mice to investigate the contribution of the Na+ ,HCO3 - -cotransporter NBCn1 (Slc4a7) to intracellular acid-base regulation in ErbB2-induced breast cancer tissue and the consequences of NBCn1 knockout for breast tumor development and growth. We demonstrate an approximately 2-fold increase of NBCn1 protein abundance in ErbB2-induced breast cancer tissue compared to normal breast tissue despite a 4-fold decrease in the NBCn1 mRNA level...
June 15, 2018: Oncogene
https://www.readbyqxmd.com/read/29905547/calcium-hydroxylapatite-microspheres-biocompatibility-and-clinical-effects
#4
U Wollina, C Wiegand, U-C Hipler
Soft tissue fillers are used in aesthetic medicine for volumizing and for contouring. Calcium hydroxylapatite (CaHA) is a fully biodegradable biostimulatory filler. The study presents results of in vitro biocompatibility and cytotoxicity investigations performed on CaHA and illustrates its clinical effects. We used a human cell culture model for in vitro studies with HaCaT keratinocytes and human dermal fibroblasts, known to be a sensitive cell type for biocompatibility and cytotoxicity. Cells were exposed to different concentrations of CaHA (Radiesse®)...
May 2018: Georgian Medical News
https://www.readbyqxmd.com/read/29905107/the-effects-of-capture-restraint-and-transport-on-hematologic-plasma-biochemical-and-blood-gas-values-in-dalmatian-pelicans-pelecanus-crispus
#5
Matthew E Kinney
To determine the effect of capture and restraint on hematologic, plasma biochemical, and venous blood gas values in Dalmatian pelicans ( Pelecanus crispus), blood samples were collected and temperature and heart rate were recorded in 13 pelicans (5 males and 8 females) immediately after capture from a large field exhibit. Repeat sampling was performed after transport, a mean of 74 minutes after initial evaluation. When compared with values at initial sampling to the time of capture, significant increases were documented in the heterophil : lymphocyte ratio (H : L), carbon dioxide (CO2 ), bicarbonate (HCO3 ), total carbon dioxide (Tco2 ), base excess (BE), and partial pressure of carbon dioxide (Pco2 ) values after 74 minutes...
June 2018: Journal of Avian Medicine and Surgery
https://www.readbyqxmd.com/read/29905068/affinity-binding-induced-hg2-releasing-and-quantum-dot-doping-for-general-label-free-and-homogenous-fluorescence-protein-assay
#6
Yishen Tian, Chen Xin, Shuang Liu, Ying Liu, Shufeng Liu
Herein, a general protein conversion and analysis strategy was well developed for homogenous, label-free, and sensitive protein detection, which was on the basis of the affinity binding-induced Hg2+ releasing for protein conversion, and the succeeding Hg2+ doping-induced ZnSe quantum dot (QD) photoluminescence for signal readout. Two DNA motifs were designed, and each of which was conjugated with a protein-specific recognition ligand. The mercury ions were initially introduced into one DNA motif by T-Hg2+-T interaction...
June 15, 2018: ACS Sensors
https://www.readbyqxmd.com/read/29904766/protonation-state-and-fine-structure-of-the-active-site-determine-the-reactivity-of-dehydratase-hydration-and-isomerization-of-%C3%AE-myrcene-catalyzed-by-linalool-dehydratase-isomerase-from-castellaniella-defragrans
#7
Baoping Ling, Xiya Wang, Hao Su, Rutao Liu, Yongjun Liu
Linalool dehydratase/isomerase (LinD) from Castellaniella defragrans is a bifunctional enzyme that catalyzes the hydration of β-myrcene to (S)-linalool and the isomerization of (S)-linalool to geraniol. In this paper, on the basis of recently obtained crystal structures, the catalytic mechanism of LinD has been explored by a combined quantum mechanics and molecular mechanics (QM/MM) approach. Two computational models have been constructed. Model I (LinD-linalool) was derived from the crystal structure of the selenomethionine derivative of LinD (Semet-LinD) in complex with the natural substrate geraniol, whereas model II (LinD-β-myrcene) was constructed from the crystal structure of LinD in complex with β-myrcene...
June 15, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29904607/water-in-the-human-body-an-anesthesiologist-s-perspective-on-the-connection-between-physicochemical-properties-of-water-and-physiologic-relevance
#8
REVIEW
Efraín Riveros-Perez, Ricardo Riveros
The unique structure and multifaceted physicochemical properties of the water molecule, in addition to its universal presence in body compartments, make water a key player in multiple biological processes in human physiology. Since anesthesiologists deal with physiologic processes where water molecules are critical at different levels, and administer medications whose pharmacokinetics and pharmacodynamics depend on interaction with water molecules, we consider that exploration of basic science aspects related to water and its role in physiology and pharmacology is relevant to the practice of anesthesiology...
February 2018: Annals of Medicine and Surgery
https://www.readbyqxmd.com/read/29904286/utility-of-venous-blood-gases-in-severe-sepsis-and-septic-shock
#9
Heath D White, Alfredo Vazquez-Sandoval, Pedro F Quiroga, Juhee Song, Shirley F Jones, Alejandro C Arroliga
Acid-base status is frequently assessed in severe sepsis and septic shock. Venous blood gas sampling is proposed as a less-invasive modality but lacks evidence within this population. The objective of this study was to evaluate the correlation and agreement between arterial blood gas (ABG), peripheral venous blood gas (pVBG), and central venous blood gas (cVBG) in severe sepsis and septic shock. We conducted a prospective, observational cohort study in subjects admitted to the medical intensive care unit. Simultaneous blood gas samples, including ABG, pVBG, and cVBG, were analyzed for correlation and agreement...
July 2018: Proceedings of the Baylor University Medical Center
https://www.readbyqxmd.com/read/29903052/poly-amino-acid-based-carrier-for-drug-delivery-systems
#10
Weikang Hu, Mei Ying, Shengmin Zhang, Jianglin Wang
Micro/nanoscale carrier is a crucial component of the drug delivery system that enables to be well designed for improving the pharmacological and therapeutic properties of drug administration. Herein we systemically review a special vector of natural poly(amino acid) (PAA) that has been extensively applied in the controlled delivery of drug, protein and gene due to its excellent biocompatibility, controlled degradability, and flexible physicochemical modification. Natural PAA is a group of poly(ionic) molecules that present various biological roles and putative technical functions...
August 1, 2018: Journal of Biomedical Nanotechnology
https://www.readbyqxmd.com/read/29902729/collagen-chitosan-hyaluronic-acid-based-injectable-hydrogels-for-tissue-engineering-applications-design-physicochemical-and-biological-characterization
#11
Adriana Gilarska, Joanna Lewandowska-Łańcucka, Wojciech Horak, Maria Nowakowska
Studies on synthesis, physico-chemical and biological properties of novel biomimetic materials, potentially useful as injectable hydrogels are presented. These materials are in situ prepared chemically crosslinked collagen/chitosan/hyaluronic acid-based hydrogels exhibiting potential for tissue regeneration. Optimization of hydrogels involved testing the effect of various concentration of crosslinking agent (genipin) as well as different ratios of biopolymers used on their properties. The changes in the content of hyaluronic acid and in the genipin concentration used have been shown to be crucial...
June 4, 2018: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/29902015/metal-free-c-o-bond-functionalization-catalytic-intramolecular-and-intermolecular-benzylation-of-arenes
#12
Luis Bering, Kirujan Jeyakumar, Andrey P Antonchick
A catalytic, metal-free intramolecular rearrangement of benzyl phenyl ethers using nitrosonium salt as a catalyst is described. The optimized reaction conditions enabled a catalytic and metal-free Friedel-Crafts alkylation reaction with benzylic alcohols, producing water as the stoichiometric byproduct. A comprehensive scope (>50 examples) for both approaches and application in drug synthesis were demonstrated. Mechanistic studies suggest a Lewis acid-based mechanism for the metal-free Friedel-Crafts reaction...
June 14, 2018: Organic Letters
https://www.readbyqxmd.com/read/29901995/remote-stereochemistry-of-a-frustrated-lewis-pair-provides-thermal-and-photochemical-control-of-reactivity
#13
Louie Fan, Andrew R Jupp, Douglas W Stephan
Hydroboration of tBuC≡CSR with (C6F5)2BH generate B/S FLPs of the form (C6F5)2B(RS)C=CH(tBu). For R = ptol the product Z-1 exhibits ¬Z stereochemistry and is monomeric in solution. This species is capable of classical Lewis acid-base chemistry and FLP reactivity with alkynes. Photoisomerization of Z-1 affords E-1, which features an intramolecular S-B interaction promoted by the remote steric influence of the tert-butyl group. E-1 is not active as an FLP under ambient conditions, but can be stimulated to react with phenylacetylene by either heat or light, and the stereochemical outcome of the product is de-pendent on the stimulus employed...
June 14, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29901732/growth-and-clinical-variables-in-nitrogen-restricted-piglets-fed-an-adjusted-essential-amino-acid-mix-effects-of-free-amino-acid-based-diets
#14
Mikkel Lykke, Per T Sangild, Johannes B van Goudoever, Dewi van Harskamp, Henk Schierbeek, Berthold Koletzko, Eline M van der Beek, Marieke Abrahamse-Berkeveld, Bert J M van de Heijning, Barbara Stoll, Douglas G Burrin, Thomas Thymann
Background: Excess protein intake in early life has been linked to obesity and metabolic syndrome in later life. Yet protein, and in particular the essential amino acids (EAAs), need to be present in adequate quantity to support growth. Objective: With the use of a piglet model restricted in dietary amino acids (AAs), we compared the efficacy and safety of a standard formula with a low-AA formula containing an adjusted AA composition. Methods: Female piglets (3-7 d old; Landrace × Yorkshire × Duroc) were fed 1 of 4 isoenergetic AA-based formulas for 14 d (700 kJ · kg body weight-1 · d-1)...
May 13, 2018: Journal of Nutrition
https://www.readbyqxmd.com/read/29901664/ultrasensitive-detection-of-nucleic-acids-based-on-dually-enhanced-fluorescence-polarization
#15
Bin Wang, Dahai Ren, Zheng You, Yaxiaer Yalikun, Yo Tanaka
Highly sensitive detection of nucleic acids is crucial for genomics, transcriptomics, and heterogeneity studies. Conventional fluorescence polarization and intensity-based assays for DNA/RNA measurements often suffer from a poor limit of detection and a long test period. A versatile nanoscale probe based on a competitive displacement assay and fluorescence polarization was proposed for the simple, fast and sensitive detection of nucleic acids. For the probe, a partially complementary double-stranded DNA (dsDNA) was used as a connector of gold nanoparticles (AuNPs) and Alexa fluor 488 dyes (Alexa488), leading to the nanometal surface energy transfer (NSET) between Alexa488 and AuNPs...
June 14, 2018: Analyst
https://www.readbyqxmd.com/read/29901244/polymer-meets-frustrated-lewis-pair-second-generation-co2-responsive-nanosystem-for-sustainable-co2-conversion
#16
Qiang Yan, Liang Chen, Renjie Liu
Frustrated Lewis pair (FLP), as a couple of sterically encumbered Lewis acid and Lewis base, can offer latent reactivity for activating inert gas molecules. However, their use as a platform for fabricating gas-responsive materials has yet developed. Merging FLP concept and polymers, we report a new generation of CO2-responsive system, differing from the first-generation ones based on acid-base equilibrium mechanism. Two complementary Lewis acidic and basic block copolymers, installing bulky borane- and phosphine-containing blocks, were built as the macromolecular FLP...
June 14, 2018: Angewandte Chemie
https://www.readbyqxmd.com/read/29900563/microbiota-and-dose-response-evolving-paradigm-of-health-triangle
#17
Margaret Coleman, Christopher Elkins, Bradford Gutting, Emmanuel Mongodin, Gloria Solano-Aguilar, Isabel Walls
SRA Dose-Response and Microbial Risk Analysis Specialty Groups jointly sponsored symposia that addressed the intersections between the "microbiome revolution" and dose response. Invited speakers presented on innovations and advances in gut and nasal microbiota (normal microbial communities) in the first decade after the Human Microbiome Project began. The microbiota and their metabolites are now known to influence health and disease directly and indirectly, through modulation of innate and adaptive immune systems and barrier function...
June 13, 2018: Risk Analysis: An Official Publication of the Society for Risk Analysis
https://www.readbyqxmd.com/read/29900471/probing-the-surface-of-%C3%AE-al-2-o-3-by-oxygen-17-dynamic-nuclear-polarization-enhanced-solid-state-nmr-spectroscopy
#18
Wenzheng Li, Qiang Wang, Jun Xu, Fabien Aussenac, Guodong Qi, Xingling Zhao, Pan Gao, Chao Wang, Feng Deng
γ-Al2O3 is an important catalyst and catalyst support of industrial interest. Its acid/base characteristics are correlated to the surface structure, which has always been an issue of concern. In this work, the complex (sub-)surface oxygen species on surface-selectively labelled γ-Al2O3 were probed by 17O dynamic nuclear polarization surface-enhanced NMR spectroscopy (DNP-SENS). Direct 17O MAS and indirect 1H-17O cross-polarization (CP)/MAS DNP experiments enable observation of the (sub-)surface bare oxygen species and hydroxyl groups...
June 14, 2018: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29898996/sensitivity-of-single-molecule-array-assays-to-detect-clostridium-difficile-toxins-in-comparison-to-conventional-laboratory-testing-algorithms
#19
Alice Banz, Aude Lantz, Brigitte Riou, Agnès Foussadier, Mark Miller, Kerrie Davies, Mark Wilcox
Background: Guidelines recommend the use of an algorithm for the laboratory diagnosis of Clostridium difficile infection (CDI). Enzyme immunoassays (EIAs) detecting C. difficile (CD) toxins cannot be used as standalone tests due to sub-optimal sensitivity and molecular tests suffer from non-specificity by detecting colonization. Sensitive immunoassays have recently been developed to improve and simplify CDI diagnosis. Methods: Assays detecting CD toxins have been developed using single molecule array technology (SIMOA)...
June 13, 2018: Journal of Clinical Microbiology
https://www.readbyqxmd.com/read/29897764/interfacial-lewis-acid-base-adduct-formation-probed-by-vibrational-spectroscopy
#20
Joel G Patrow, Yi Wang, Jahan M Dawlaty
Understanding Lewis pair (LP) interactions at heterogeneous environments is important for controlling surface reactions. We report the formation of interfacial Lewis adducts with tris(pentafuorophenyl) borane as the Lewis acid and 4-mercaptobenzonitrile attached to gold as the Lewis base. We use the nitrile vibrational frequency as a probe of adduct strength, with stronger adducts leading to larger frequencies. The vibrational frequency shifts of the surface adducts were measured via sum frequency generation spectroscopy and compared to the frequency shifts of bulk adducts...
June 13, 2018: Journal of Physical Chemistry Letters
keyword
keyword
22792
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"