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https://www.readbyqxmd.com/read/28651221/risk-element-immobilization-stabilization-potential-of-fungal-transformed-dry-olive-residue-and-arbuscular-mycorrhizal-fungi-application-in-contaminated-soils
#1
Mercedes García-Sánchez, Tereza Stejskalová, Inmaculada García-Romera, Jiřina Száková, Pavel Tlustoš
The use of biotransformed dry olive residue (DOR) as organic soil amendment has recently been proposed due to its high contents of stabilized organic matter and nutrients. The potential of biotransformed DOR to immobilize risk elements in contaminated soils might qualify DOR as a potential risk element stabilization agent for in situ soil reclamation practices. In this experiment, the mobility of risk elements in response to Penicillium chrysogenum-10-transformed DOR, Funalia floccosa-transformed DOR, Bjerkandera adusta-transformed DOR, and Chondrostereum purpureum-transformed DOR as well as arbuscular mycorrhizal fungi (AMF), Funneliformis mosseae, inoculation was investigated...
June 23, 2017: Journal of Environmental Management
https://www.readbyqxmd.com/read/28650660/ph-triggered-recovery-and-reuse-of-thiolated-poly-acryl-acid-functionalized-gold-nanoparticles-with-applications-in-colloidal-catalysis
#2
Siyam M Ansar, Benjamin D Fellows, Patrick Mispireta, O Thompson Mefford, Christopher L Kitchens
Thiolated poly(acrylic acid) (PAA-SH) functionalized gold nanoparticles were explored as a colloidal catalyst with potential application as a recoverable catalyst where the PAA provides pH-responsive dispersibility and phase transfer capability between aqueous and organic media. This system demonstrates complete nanoparticle recovery and redispersion over multiple reaction cycles without changes in nanoparticle morphology or reduction in conversion. The catalytic activity (rate constant) was reduced in subsequent reactions when recovery by aggregation was employed, despite unobservable changes in morphology or dispersability...
June 26, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28650571/development-of-proton-responsive-catalysts
#3
REVIEW
Lin Wang, Ryoichi Kanega, Hajime Kawanami, Yuichiro Himeda
A changeable ligand, which involves in activation of a catalyst or assists a reaction, draws an increasing attention, in contrast to a classical ligand as spectator. Proton-responsive catalysts, which are capable of undergoing changes of properties on gaining/losing one or more protons, provides interesting features as follows: (i) catalyst activation by electronic effect, (ii) pH-tuning of water-solubility, and (iii) second-coordination-sphere interaction. On the basis of this catalyst design concept, we developed several highly efficient proton-responsive catalysts for CO2 hydrogenation as H2 storage, formic acid (FA) dehydrogenation as H2 production, and transfer hydrogenation...
June 26, 2017: Chemical Record: An Official Publication of the Chemical Society of Japan ... [et Al.]
https://www.readbyqxmd.com/read/28650501/ph-responsive-near-infrared-fluorescent-cyanine-dyes-for-molecular-imaging-based-on-ph-sensing
#4
Koji Miki, Kentaro Kojima, Kazuaki Oride, Hiroshi Harada, Akiyo Morinibu, Kouichi Ohe
Indocyanine green (ICG) derivatives having nucleophilic substituents were synthesized as pH-responsive near-infrared dyes. pH-responsive dyes 1-C with closed-ring structures smoothly internalized and converted to emissive open-ring structures 1-O in response to relatively low pHs in acidic intracellular compartments of HeLa cells.
June 26, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28650053/in-situ-crystal-growth-of-gold-nanocrystals-on-upconversion-nanoparticles-for-synergistic-chemo-photothermal-therapy
#5
Ruoyan Wei, Wensong Xi, Haifang Wang, Jinliang Liu, Torsten Mayr, Liyi Shi, Lining Sun
A multifunctional cancer therapy nanocomposite was proposed and synthesized by linking the pH-responsive SH-PEG-DOX prodrug onto gold nanocrystals that were grown in situ on the surface of upconversion nanoparticles (UCNPs). In the structure of the SH-PEG-DOX prodrug, a hydrazone bond was utilized for subsequent pH-responsive drug release in the intracellular acidic microenvironment of cancer cells. This innovative assembly method is facile and mild, and can be used to obtain nanocomposites of UCNPs and gold, which show excellent photostability and biocompatibility...
June 26, 2017: Nanoscale
https://www.readbyqxmd.com/read/28650042/monitoring-aggregation-of-a-ph-responsive-polymer-via-proton-exchange
#6
Ipsita Chakraborty, Ishita Mukherjee, Ujjal Haldar, Priyadarsi De, Rangeet Bhattacharyya
Understanding the changes in the macro-structure of amphiphilic pH-responsive polymers remains a relevant issue due to their potential use as drug delivery carriers. Since some of the amphiphilic polymers are known to exchange hydrogen ions with an aqueous solvent, we monitor the effective change of the surface to volume ratio of such polymer aggregates using solution-state nuclear magnetic resonance (NMR) spectroscopy. The surface to volume ratio with the help of UV-visible spectroscopy is shown to yield the average diameter of the polymer aggregates...
June 26, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28649828/dimerization-of-the-conserved-n-terminal-domain-of-a-spider-silk-protein-controls-the-self-assembly-of-the-repetitive-core-domain
#7
Joschka Bauer, Thomas Scheibel
Spider silk proteins comprise a repetitive core domain with polyalanine and glycine/proline stretches flanked by highly conserved nonrepetitive N- and C-terminal domains. The termini are responsive to assembly triggers, sensing changes in the ionic (H+, phosphate) and mechanical (shear stress) environment along the spinning duct. Upon assembly, the N-terminal domain dimerizes in a pH-dependent manner induced by protonation of conserved acidic residues. So far, dimerization of N-terminal spider silk domains has been individually investigated in the absence of large core domains...
June 26, 2017: Biomacromolecules
https://www.readbyqxmd.com/read/28649701/a-switchable-open-closed-polyaromatic-macrocycle-and-its-reversible-binding-of-long-hydrophilic-molecules
#8
Kohei Kurihara, Kohei Yazaki, Munetaka Akita, Michito Yoshizawa
In spite of wide-ranging previous studies on synthetic macrocycles, installation of open-close functions into the frameworks remains a knotty challenge. Here we present a new polyaromatic macrocycle capable of switching between open and closed forms in response to external stimuli, base and acid. The macrocycle, prepared in three steps, has a well-defined hydrophobic cavity with dimensions of ~1 nm, surrounded by four pH-responsive acridinium panels. The open and closed structures are definitely confirmed by X-ray single-crystal analysis...
June 26, 2017: Angewandte Chemie
https://www.readbyqxmd.com/read/28649006/optimization-of-hydrogel-containing-toluidine-blue-o-for-photodynamic-therapy-by-response-surface-methodology
#9
Hui Liang, Jialin Xu, Yunfeng Liu, Jianxing Zhang, Wei Peng, Jinhua Yan, Zelin Li, Qingyong Li
Photodynamic therapy with toluidine blue O (TBO) hydrogel exhibits antibacterial activity against Staphylococcus aureus and Escherichia coli in this paper. The response surface methodology is employed to optimize formulations for antibacterial activity. The optimal formulations are carbomer concentration of 3% (w/v), TBO concentration of 0.1mg/mL and the quality ratio of NaOH and carbomer of 0.4 (w/w). Under the optimized formulations, the log-transformed of CFUmL(-1) on the Staphylococcus aureus and Escherichia coli are 0...
June 16, 2017: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/28648851/the-influence-of-mild-acidity-on-lysyl-phosphatidylglycerol-biosynthesis-and-lipid-membrane-physico-chemical-properties-in-methicillin-resistant-staphylococcus-aureus
#10
Reg P Rehal, Helene Marbach, Alasdair T M Hubbard, Anam A Sacranie, Federica Sebastiani, Giovanna Fragneto, Richard D Harvey
The increased biosynthesis of lysyl-phosphatidylglycerol in Staphylococcus aureus when cultured under conditions of mild acidity and the resultant increased proportion of this lipid in the plasma membrane of the bacterium, alters the physico-chemical properties of lipid bilayers in a manner which is itself dependent upon environmental pH. Clinically relevant strains of S. aureus, both methicillin susceptible and resistant, all exhibited increased lysyl-phosphatidylglycerol biosynthesis in response to mild environmental acidity, albeit to differing degrees, from ∼30% to ∼55% total phospholipid...
June 22, 2017: Chemistry and Physics of Lipids
https://www.readbyqxmd.com/read/28648786/selective-screening-of-glutaric-acid-acidurias-by-capillary-electrophoresis-mass-spectrometry
#11
Jaime Fernández-Bravo, Fernando de Andrés, Mohammed Zougagh, Ángel Ríos
A sensitive and selective method for the separation and quantification of the three organic acids 3-hydroxy-3-methylglutaric acid, 3-methylglutaric acid, and glutaric acid in human urine samples by CE with mass spectrometry detection has been developed. This methodology is faster, simpler and less time-consuming, than other methodologies previously described, and requires of reduced amounts of reagents as well. Samples are first filtered and then diluted in water. For the electrophoretic separation, a 20mM ammonium acetate and 10% methanol solution at pH 9...
June 19, 2017: Journal of Pharmaceutical and Biomedical Analysis
https://www.readbyqxmd.com/read/28648357/acidic-stress-enhances-covr-s-dependent-gene-repression-through-activation-of-the-covr-s-promoter-in-emm1-type-group-a-streptococcus
#12
Chuan Chiang-Ni, Huei-Chuan Tseng, Chia-Hui Hung, Cheng-Hsun Chiu
Streptococcus pyogenes (group A Streptococcus) is a clinically important gram-positive bacterium that causes severe diseases with high mortality. Spontaneous mutations in genes encoding the CovR/CovS two-component regulatory system have been shown to derepress expression of virulence factors and are significantly associated with invasiveness of infections. Sensor kinase CovS senses environmental signals and then regulates the levels of phosphorylated CovR. In addition, CovS is responsible for survival of group A Streptococcus under acidic stress...
June 16, 2017: International Journal of Medical Microbiology: IJMM
https://www.readbyqxmd.com/read/28648074/boronic-acid-functionalized-oxide-free-silicon-surfaces-for-the-electrochemical-sensing-of-dopamine
#13
Bruno Fabre, Fanny Hauquier
Boronic acid monolayers covalently bound to hydrogen-terminated Si(111) surfaces have been prepared from the UV-directed hydrosilylation reaction of 4-vinylbenzeneboronic acid. X-ray photoelectron spectroscopy (XPS) analysis of the modified surface revealed characteristics peaks from the attached organic molecule with the expected molecular composition and without oxidation of underlying silicon. From XPS data, the surface coverage was estimated to be ca. 0.34 ± 0.04 ethylbenzene boronic acid chain per surface silicon atom (i...
June 24, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28647588/environmentally-relevant-concentrations-of-al-iii-and-fe-iii-cations-induce-aggregation-of-free-dna-by-complexation-with-phosphate-group
#14
Chao Qin, Fuxing Kang, Wei Zhang, Weijun Shou, Xiaojie Hu, Yanzheng Gao
Environmental persistence of free DNA is influenced by its complexation with other chemical species and its aggregation mechanisms. However, it is not well-known how naturally-abundant metal ions, e.g., Al(III) and Fe(III), influence DNA aggregation. This study investigated aggregation behaviors of model DNA from salmon testes as influenced by metal cations, and elucidated the predominant mechanism responsible for DNA aggregation. Compared to monovalent (K(+) and Na(+)) and divalent (Ca(2+) and Mg(2+)) cations, Al(III) and Fe(III) species in aqueous solution caused rapid DNA aggregations...
June 18, 2017: Water Research
https://www.readbyqxmd.com/read/28647524/preparation-and-evaluation-of-bsa-based-hydrosol-nanoparticles-cross-linked-with-genipin-for-oral-administration-of-poorly-water-soluble-curcumin
#15
Narges Shahgholian, Ghadir Rajabzadeh, Bizhan Malaekeh-Nikouei
One of the most interesting functions of albumin is the ability to interact with bioactive compounds. This study describes preparation of protein-based nanoparticles (NPs) for the preparation of solid dispersion of curcumin (CN). Fabrication of hydrosol system of dispersed CN in bovine serum albumin (BSA) was approached, followed by cross-linking with glutaraldehyde (Gta). Response surface methodology (RSM) was used to investigate the influence of input factors (pH, CN content and organic phase ratio (r)), on the particle size and CN entrapment efficiency (EE)...
June 21, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28646781/%C3%AE-potential-evidences-silanol-heterogeneity-induced-by-metal-contaminants-at-the-quartz-surface-implications-in-membrane-damage
#16
Cristina Pavan, Francesco Turci, Maura Tomatis, Mara Ghiazza, Dominique Lison, Bice Fubini
Among the physico-chemical features responsible for the so-called "variability of quartz hazard", a key role has been assigned to the silica surface charge, evaluated by means of ζ potential measurement. The ζ potential of silica describes the protonation state of silanols which, in turn, determine interactions with cell membranes. To gain a molecular understanding of the role of silanols in silica pathogenicity, we conducted a systematic investigation of the variation of the ζ potential as a function of pH (ζ plot titration curve) on a large set of respirable quartz particles with different levels of metal contaminants...
June 13, 2017: Colloids and Surfaces. B, Biointerfaces
https://www.readbyqxmd.com/read/28646424/proteasome-properties-of-hemocytes-differ-between-the-whiteleg-shrimp-penaeus-vannamei-and-the-brown-shrimp-crangon-crangon-crustacea-decapoda
#17
Sandra Götze, Reinhard Saborowski, Oliviert Martínez-Cruz, Adriana Muhlia-Almazán, Arturo Sánchez-Paz
Crustaceans are intensively farmed in aquaculture facilities where they are vulnerable to parasites, bacteria, or viruses, often severely compromising the rearing success. The ubiquitin-proteasome system (UPS) is crucial for the maintenance of cellular integrity. Analogous to higher vertebrates, the UPS of crustaceans may also play an important role in stress resistance and pathogen defense. We studied the general properties of the proteasome system in the hemocytes of the whiteleg shrimp, Penaeus vannamei, and the European brown shrimp Crangon crangon...
June 23, 2017: Cell Stress & Chaperones
https://www.readbyqxmd.com/read/28646233/identifying-community-thresholds-for-lotic-benthic-diatoms-in-response-to-human-disturbance
#18
Tao Tang, Ting Tang, Lu Tan, Yuan Gu, Wanxiang Jiang, Qinghua Cai
Although human disturbance indirectly influences lotic assemblages through modifying physical and chemical conditions, identifying thresholds of human disturbance would provide direct evidence for preventing anthropogenic degradation of biological conditions. In the present study, we used data obtained from tributaries of the Three Gorges Reservoir in China to detect effects of human disturbance on streams and to identify disturbance thresholds for benthic diatoms. Diatom species composition was significantly affected by three in-stream stressors including TP, TN and pH...
June 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28646092/deletion-analysis-of-agd1-reveals-domains-crucial-for-its-plasma-membrane-recruitment-and-function-in-root-hair-polarity
#19
Cheol-Min Yoo, Satoshi Naramoto, J Alan Sparks, Bibi Rafeiza Khan, Jin Nakashima, Hiroo Fukuda, Elison B Blancaflor
AGD1, a plant ACAP-type ADP-ribosylation factor-GTPase activating protein (ARF-GAP), functions in specifying root hair polarity in Arabidopsis thaliana To better understand how AGD1 modulates root hair growth, we generated full length and domain-deleted AGD1-green fluorescent protein (GFP) constructs, and followed their localization during root hair development. AGD1-GFP localized to the cytoplasm and was recruited to specific regions of the root hair plasma membrane (PM). Distinct PM AGD1-GFP signal was first detected along the site of root hair bulge formation...
June 23, 2017: Journal of Cell Science
https://www.readbyqxmd.com/read/28645630/evolution-of-cyclodextrin-nanosponges
#20
Fabrizio Caldera, Maria Tannous, Roberta Cavalli, Marco Zanetti, Francesco Trotta
Cyclodextrin-based nanosponges (CD-NSs) are insoluble, highly cross-linked 3D network polymers used in several scientific and technological fields, the main area of investigation concerns the pharmaceutical applications, in which CD-NSs have been mostly employed as drug delivery systems. CD-NSs can be generally grouped into four consecutive generations, taking into account their chemical composition and properties. The 1st generation of NSs are plain nanosponges, subdivided into four main types: urethane, carbonate, ester and ether NSs, depending on the chemical nature of the functional group connecting the CD to the cross-linker...
June 20, 2017: International Journal of Pharmaceutics
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