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https://www.readbyqxmd.com/read/28215026/separation-of-peptides-on-superficially-porous-particle-based-macrocyclic-glycopeptide-liquid-chromatography-stationary-phases-consideration-of-fast-separations
#1
Rasangi M Wimalasinghe, Zachary S Breitbach, Jauh T Lee, Daniel W Armstrong
Macrocyclic glycopeptide based liquid chromatography stationary phases are known for their highly selective peptide separations. Fast and ultrafast (t R < 1 min) high-efficiency separations were achieved with superficially porous particle (SPP)-based stationary phases. Separations of pharmaceutically important classes of peptides such as enkephalins and bradykinins have been achieved in less than 5 min in isocratic elution modes. Selectivity for peptides structurally similar to one another was increased with use of teicoplanin-based stationary phases compared with commercial C18 stationary phases...
February 18, 2017: Analytical and Bioanalytical Chemistry
https://www.readbyqxmd.com/read/28214748/electrochemical-monitoring-of-biointeraction-by-graphene-based-material-modified-pencil-graphite-electrode
#2
Ece Eksin, Erhan Zor, Arzum Erdem, Haluk Bingol
Recently, the low-cost effective biosensing systems based on advanced nanomaterials have received a key attention for development of novel assays for rapid and sequence-specific nucleic acid detection. The electrochemical biosensor based on reduced graphene oxide (rGO) modified disposable pencil graphite electrodes (PGEs) were developed herein for electrochemical monitoring of DNA, and also for monitoring of biointeraction occurred between anticancer drug, Daunorubicin (DNR), and DNA. First, rGO was synthesized chemically and characterized by using UV-Vis, TGA, FT-IR, Raman Spectroscopy and SEM techniques...
February 11, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28214746/a-magnetite-pmaa-nanospheres-targeting-sers-aptasensor-for-tetracycline-sensing-using-mercapto-molecules-embedded-core-shell-nanoparticles-for-signal-amplification
#3
Huanhuan Li, Quansheng Chen, Md Mehedi Hassan, Xiaoxing Chen, Qin Ouyang, Zhiming Guo, Jiewen Zhao
Surface-enhanced Raman scattering (SERS) biosensors have promising potential in the field of antibiotics detection because of their ultrahigh detection sensitivity. This paper reports a rapid and sensitive SERS-based magnetic nanospheres-targeting strategy for sensing tetracycline (TTC) using aptamer-conjugated magnetite colloid nanocrystal clusters (MCNCs)-polymethacrylic acid (PMAA) magnetic nanospheres (MNs) as the recognition and the Au/PATP/SiO2 (APS) as the labels. Initially, MNs were fabricated and conjugated with the aptamers through condensation reaction...
February 7, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28214744/tuning-of-the-selectivity-of-fluorescent-peptidyl-bioprobe-using-aggregation-induced-emission-for-heavy-metal-ions-by-buffering-agents-in-100-aqueous-solutions
#4
Lok Nath Neupane, Gi Won Hwang, Keun-Hyeung Lee
Smart fluorescent probes of which the detection of specific target molecules can be controlled are attracting remarkable interest. A fluorescent peptidyl bioprobe (1) was rationally synthesized by conjugating tetraphenylethylene, an aggregation-induced emission (AIE) fluorophore with a peptide receptor (AspHis) that acted as hard and intermediate bases. The selective detection of 1 for specific metal ion in 100% aqueous solutions was controlled by the buffering agents with the chelate effect without the change of pH...
February 3, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28214728/lipid-signalling-mediated-by-pld-pa-modulates-proline-and-h2o2-levels-in-barley-seedlings-exposed-to-short-and-long-term-chilling-stress
#5
Micaela Peppino Margutti, Matias Reyna, María Verónica Meringer, Graciela E Racagni, Ana Laura Villasuso
Phospholipase D (PLD) hydrolyses phospholipids to yield phosphatidic acid (PA) and a head group, and is involved in responses to a variety of environmental stresses, including chilling and freezing stress. Barley responses to chilling stress (induced by incubating seedlings at 4 °C) are dynamic and the duration of stress, either short (0-180 min) or long-term (24-36 h) had a significant impact on the response. We investigated the roles of PLD/PA in responses of barley (Hordeum vulgare) seedlings to short and long-term chilling stress, based on regulation of proline and reactive oxygen species (ROS) levels...
February 10, 2017: Plant Physiology and Biochemistry: PPB
https://www.readbyqxmd.com/read/28214676/chiral-aminoquinoline-based-fluorescent-ph-probe-with-large-stokes-shift-for-bioimaging
#6
Yong-Sheng Xie, Xin-Ling Zhang, Kun Xie, Yanmei Zhao, Huan Wu, Jidong Yang
The aminoquinoline derivatives, (R)- and (S)-2-phenyl-2-(quinolin-6-ylamino)ethan-1-ol (R-PEO and S-PEO), were synthesized by a tandem one-pot three-step CN coupling method where Smiles rearrangement was the key procedure. The selected compound R-PEO showed a significant fluorescence enhancement with a turn-on ratio over 98-fold and enabled the real time determination of proton concentration in acidic solution. The fluorescence intensity of R-PEO exhibited strong pH-dependent performance with a large Stokes shift (115nm) and responded linearly to minor pH change within the range of 3...
February 12, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/28214671/atp-mediated-intrinsic-peroxidase-like-activity-of-fe3o4-based-nanozyme-one-step-detection-of-blood-glucose-at-physiological-ph
#7
N V Srikanth Vallabani, Ajay S Karakoti, Sanjay Singh
Fe3O4 nanoparticles (Fe3O4 NPs), demonstrating peroxidase-like activity has garnered attention in the detection of several biomolecules, therefore, emerged as an excellent nano-biosensing agent. The intrinsic peroxidase-like activity of Fe3O4 NPs at acidic pH is the fundamental action driving the oxidation of substrates like TMB, resulting in a colorimetric product formation used in the detection of biomolecules. Hence, the detection sensitivity essentially depends on the ability of oxidation by Fe3O4 NPs in presence of H2O2...
February 9, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28214670/metal-mediated-dna-assembly-with-ligand-based-nucleosides
#8
REVIEW
Soham Mandal, Jens Müller
Nucleic acids such as DNA are increasingly being applied in nanotechnology, as a result of their capability to self-assemble reversibly. The formal replacement of canonical base pairs by metal-mediated ones enables a site-specific introduction of metal-based functionality into these biomolecules, leading to the formation of predesigned metal arrays. This article offers an overview of structural aspects of metal-mediated base pairs, reviews recent advances in the field of metal-mediated base pairing and presents potential applications of the resulting metal-modified nucleic acids...
February 16, 2017: Current Opinion in Chemical Biology
https://www.readbyqxmd.com/read/28214630/ph-and-reduction-dual-responsive-dipeptide-cationic-lipids-with-%C3%AE-tocopherol-hydrophobic-tail-for-efficient-gene-delivery
#9
Qiang Liu, Rong-Chuan Su, Wen-Jing Yi, Li-Ting Zheng, Shan-Shan Lu, Zhi-Gang Zhao
A series of tocopherol-based cationic lipid 3a-3f bearing a pH-sensitive imidazole moiety in the dipeptide headgroup and a reduction-responsive disulfide linkage were designed and synthesized. Acid-base titration of these lipids showed good buffering capacities. The liposomes formed from 3 and co-lipid 1, 2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) could efficiently bind and condense DNA into nanoparticles. Gel binding and HPLC assays confirmed the encapsulated DNA could release from lipoplexes 3 upon addition of 10 mM glutathione (GSH)...
February 12, 2017: European Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/28214603/the-impact-of-reduced-gastric-acid-secretion-on-dissolution-of-salts-of-weak-bases-in-the-fasted-upper-gastrointestinal-lumen-data-in-biorelevant-media-and-in-human-aspirates
#10
Chara Litou, Maria Vertzoni, Wei Xu, Filippos Kesisoglou, Christos Reppas
PURPOSE: To propose media for simulating the intragastric environment under reduced gastric acid secretion in the fasted state at three levels of simulation of the gastric environment and evaluate their usefulness in evaluating the intragastric dissolution of salts of weak bases. To evaluate the importance of bicarbonate buffer in biorelevant in vitro dissolution testing when using Level II biorelevant media simulating the environment in the fasted upper small intestine, regardless of gastric acid secretions...
February 15, 2017: European Journal of Pharmaceutics and Biopharmaceutics
https://www.readbyqxmd.com/read/28214555/identification-of-a-fatty-acid-binding-protein4-ucp2-axis-regulating-microglial-mediated-neuroinflammation
#11
Cayla M Duffy, Hongliang Xu, Joshua P Nixon, David A Bernlohr, Tammy A Butterick
Hypothalamic inflammation contributes to metabolic dysregulation and the onset of obesity. Dietary saturated fats activate microglia via a nuclear factor-kappa B (NFκB) mediated pathway to release pro-inflammatory cytokines resulting in dysfunction or death of surrounding neurons. Fatty acid binding proteins (FABPs) are lipid chaperones regulating metabolic and inflammatory pathways in response to fatty acids. Loss of FABP4 in peripheral macrophages via either molecular or pharmacologic mechanisms results in reduced obesity-induced inflammation via a UCP2-redox based mechanism...
February 15, 2017: Molecular and Cellular Neurosciences
https://www.readbyqxmd.com/read/28214519/detection-and-quantification-of-soil-transmitted-helminths-in-environmental-samples-a-review-of-current-state-of-the-art-and-future-perspectives
#12
REVIEW
Isaac Dennis Amoah, Gulshan Singh, Thor Axel Stenström, Poovendhree Reddy
It is estimated that over a billion people are infected with soil-transmitted helminths (STHs) globally with majority occurring in tropical and subtropical regions of the world. The roundworm (Ascaris lumbricoides), whipworm (Trichuris trichiura), and hookworms (Anclostoma duodenale and Necator americanus) are the main species infecting people. These infections are mostly gained through exposure to faecally contaminated water, soil or contaminated food and with an increase in the risk of infections due to wastewater and sludge reuse in agriculture...
February 15, 2017: Acta Tropica
https://www.readbyqxmd.com/read/28214380/application-of-the-mechpeff-model-to-predict-passive-effective-intestinal-permeability-in-the-different-regions-of-the-rodent-small-intestine-and-colon
#13
D Pade, M Jamei, A Rostami-Hodjegan, D B Turner
A major component of Physiologically-Based Pharmacokinetic (PBPK) models is prediction of the rate and extent of absorption of orally dosed drugs for which knowledge of effective passive intestinal permeability (Peff ) is essential. Single pass intestinal perfusion (SPIP) studies are used to establish effective permeability in vivo but are difficult to perform in rodents while mechanistic models to predict drug Peff in rat and mouse have not been published. This work evaluates the predictive performance of the 'MechPeff' model to predict Peff in the rodent intestine based upon knowledge of regional gut physiology and drug-specific physicochemical parameters...
February 18, 2017: Biopharmaceutics & Drug Disposition
https://www.readbyqxmd.com/read/28214354/long-chain-unsaturated-fatty-acids-as-possible-important-metabolites-for-primary-angle-closure-glaucoma-based-on-targeted-metabolomic-analysis
#14
Shengzhong Rong, Yang Li, Yue Guan, Lili Zhu, Qiang Zhou, Mucong Gao, Hongzhi Pan, Lina Zou, Dong Chang
Primary angle-closure glaucoma (PACG) is a severe chronic neurodegenerative disease in Asia. Identification of important metabolites associated with PACG is crucial for early intervention and advancing knowledge of the disease mechanism. We applied gas chromatography-mass spectrometry (GC-MS) for targeted metabolomic analysis on serum samples from thirty-eight newly diagnosed PACG patients and forty-eight controls. Palmitoleic acid (PA), linoleic acid (LA), gamma-linolenic acid (GLA) and arachidonic acid (ARA) were identified as important metabolites associated with PACG...
February 18, 2017: Biomedical Chromatography: BMC
https://www.readbyqxmd.com/read/28214199/primary-acinic-cell-carcinoma-of-the-lung-with-psammoma-bodies-a-case-report-and-review-of-literature
#15
Xiu-Peng Zhang, Gui-Yang Jiang, Qing-Fu Zhang, Hong-Tao Xu, Qing-Chang Li, En-Hua Wang
Salivary gland-type tumors are rare in the lung. Primary acinic cell carcinoma of the lung is extremely rare. Here, we report a case of primary acinic cell carcinoma of the lung with prominent psammoma bodies. A 31-year-old man came to our hospital with a tumor in the basal segment of the lower lobe of the right lung. The tumor tissue displayed solid, acinar, or microcystic structures at different regions. A large amount of psammoma bodies were scattered in more than half of the tumor. The majority of the tumor cells were round or polygonal in shape, with abundant acidophilic granular or vacuolated cytoplasm...
January 19, 2017: Pathology, Research and Practice
https://www.readbyqxmd.com/read/28213944/separation-of-hydroxynorketamine-stereoisomers-using-capillary-electrophoresis-with-sulfated-%C3%AE-cyclodextrin-and-highly-sulfated-%C3%AE-cyclodextrin
#16
Friederike A Sandbaumhüter, Regula Theurillat, Wolfgang Thormann
The racemic N-methyl-d-aspartate receptor antagonist ketamine is used in anesthesia, analgesia and the treatment of depressive disorders. It is known that interactions of hydroxylated norketamine metabolites and 5,6-dehydronorketamine (DHNK) with the α7 -nicotinic acetylcholine receptor and the α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor are responsible for the antidepressive effects. Ketamine and its first metabolite norketamine are not active on these receptors. As stereoselectivity plays a role in ketamine metabolism, a cationic capillary electrophoresis based method capable of resolving and analyzing the stereoisomers of four hydroxylated norketamine metabolites, norketamine and DHNK was developed...
February 18, 2017: Electrophoresis
https://www.readbyqxmd.com/read/28213873/first-isolation-and-genetic-characteristics-of-porcine-sapeloviruses-in-hunan-china
#17
Taotao Yang, Runcheng Li, Wang Peng, Meng Ge, Binyu Luo, Tailong Qu, Xinglong Yu
Outbreaks of diarrhea in piglets cause serious economic consequences in China. Diarrhetic fecal samples from 20 Hunan farm piglets were tested and found to be positive for porcine epidemic diarrhea virus (PEDV) by RT-PCR, although incubation with porcine kidney (PK-15) cells failed to produce infectious PEDV. Four porcine sapelovirus (PSV) strains (designated as PSV-HuNs) were isolated from four of the samples. Genomic sequence analysis revealed open reading frames encoding polyproteins of 2,331 (HuN1, 2 and 3) and 2,332 (HuN4) amino acids...
February 17, 2017: Archives of Virology
https://www.readbyqxmd.com/read/28213870/molecular-characterization-of-bovine-leukemia-virus-from-moldovan-dairy-cattle
#18
Aneta Pluta, Marzena Rola-Łuszczak, Piotr Kubiś, Svetlana Balov, Roman Moskalik, Bhudipa Choudhury, Jacek Kuźmak
Bovine leukemia virus (BLV) is the causative agent of enzootic bovine leukosis (EBL), a disease that has worldwide distribution. Whilst it has been eradicated in most of Western Europe and Scandinavia, it remains a problem in other regions, particularly Eastern Europe and South America. For this study, in 2013, 24 cattle from three farms in three regions of Moldova were screened by ELISA and nested PCR. Of these cattle, 14 which were PCR positive, and these were molecularly characterized based on the nucleotide sequence of the env gene and the deduced amino acid sequence of the encoded gp51 protein...
February 17, 2017: Archives of Virology
https://www.readbyqxmd.com/read/28213710/biohydrogen-production-from-sugarcane-bagasse-hydrolysate-effects-of-ph-s-x-fe-2-and-magnetite-nanoparticles
#19
Karen Reddy, Mahmoud Nasr, Sheena Kumari, Santhosh Kumar, Sanjay Kumar Gupta, Abimbola Motunrayo Enitan, Faizal Bux
Batch dark fermentation experiments were conducted to investigate the effects of initial pH, substrate-to-biomass (S/X) ratio, and concentrations of Fe(2+) and magnetite nanoparticles on biohydrogen production from sugarcane bagasse (SCB) hydrolysate. By applying the response surface methodology, the optimum condition of steam-acid hydrolysis was 0.64% (v/v) H2SO4 for 55.7 min, which obtained a sugar yield of 274 mg g(-1). The maximum hydrogen yield (HY) of 0.874 mol (mol glucose(-1)) was detected at the optimum pH of 5...
February 18, 2017: Environmental Science and Pollution Research International
https://www.readbyqxmd.com/read/28213541/accurate-quantification-of-laminarin-in-marine-organic-matter-with-enzymes-from-marine-microbes
#20
Stefan Becker, André Scheffel, Martin F Polz, Jan-Hendrik Hehemann
Marine algae produce varieties of glycans, which fulfill diverse biological functions and fuel the carbon and energy demand of heterotrophic microbes. A common approach to analyze marine organic matter uses acid to hydrolyze its glycans into measurable monosaccharides. These, however, may derive from different glycans that are built with the same monosaccharides, hence this approach does not distinguish between glycans in natural samples. Here we use enzymes to selectively digest and thereby quantify laminarin in particulate organic matter...
February 17, 2017: Applied and Environmental Microbiology
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