Read by QxMD icon Read

Strong ion difference

Ramesh Raj Pant, Fan Zhang, Faizan Ur Rehman, Guanxing Wang, Ming Ye, Chen Zeng, Handuo Tang
The characterization and assessment of water quality in the head water region of Himalaya is necessary, given the immense importance of this region in sustaining livelihoods of people and maintaining ecological balance. A total of 165 water samples were collected from 55 sites during pre-monsoon, monsoon and post-monsoon seasons in 2016 from the Gandaki River Basin of the Central Himalaya, Nepal. The pH, EC values and TDS concentrations were measured in-situ and the concentrations of major ions (Ca2+, Mg2+, K+, Na+, Cl-, SO42-, NO3-) and Si were analyzed in laboratory...
December 7, 2017: Science of the Total Environment
V M Gun'ko, T V Krupska, L S Andriyko, N Yu Klymenko, I V Siora, O A Novikova, A I Marynin, A I Ukrainets, B Charmas, S B Shekhunova, V V Turov
Interaction of doxorubicin hydrochloride (DOX) (anti-cancer drug) with hydro-compacted nanosilica A-300 (cA-300) alone or cA-300/human serum albumin (HSA) at a small content of water (h = 0.4 g per gram of dry silica) in different dispersion media (air, chloroform, and chloroform/trifluoroacetic acid) was analyzed using low-temperature 1H NMR spectroscopy, NMR cryoporometry and quantum chemistry to elucidate specific changes in the interfacial layers. Initial (bulk density ρb ≈ 0.046 g/cm3) and hydro-compacted (ρb ≈ 0...
December 5, 2017: Journal of Colloid and Interface Science
Hui Yan, Zhe Han, Kaiming Li, Guangyong Li, Xilian Wei
We performed molecular dynamics simulations to study the pH-induced structural transitions for aqueous mixtures of a cationic surfactant (cetyltrimethylammonium bromide, CTAB) and a hydrotrope (sodium salicylate, NaSal). We obtained rigid cylindrical, spherical, and flexible cylindrical micelles at pH 7, 2, and 0, respectively, which agrees well with the experimental results of Umeasiegbu et al. (Langmuir 2016, 32, 655). With analyzing the different micellar structural properties, including distribution and molecular orientation of CTA+ and Sal- inside the micelle, we found the binding form of the protonated salicylate molecules with CTA+ is different from that of Sal- ions...
December 7, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
Evelyne Deplazes, David Poger, Bruce Cornell, Charles G Cranfield
This work seeks to identify the mechanisms by which hydronium ions (H3O+) modulate the structure of phospholipid bilayers by studying the interactions of H3O+ with phospholipids at the molecular level. For this, we carried out multiple microsecond-long unrestrained molecular dynamics (MD) simulations of a POPC bilayer at different H3O+ concentrations. The results show that H3O+ accumulates at the membrane surface where it displaces water and forms strong and long-lived hydrogen bonds with the phosphate and carbonyl oxygens in phospholipids...
December 6, 2017: Physical Chemistry Chemical Physics: PCCP
Ke Xu Zhou, Adrian Ionescu, Eamon Wan, Yeuk Nam Ho, Crispin H W Barnes, Graham Christie, D Ian Wilson
Spores of Bacillus megaterium, B. cereus and B. subtilis were found to exhibit intrinsic paramagnetic properties as a result of the accumulation of manganese ions. All three Bacillus species displayed strong yet distinctive magnetic properties arising from differences in manganese quantity and valency. Manganese ions were found to accumulate both within the spore core as well as being associated with the surface of the spore. Bacillus megaterium spores accumulated up to 1 wt. % manganese (II) within, with a further 0...
December 4, 2017: Biotechnology and Bioengineering
Robert Matera, Katalin V Horvath, Hari Nair, Ernst J Schaefer, Bela F Asztalos
BACKGROUND: HDL cell cholesterol efflux capacity has been documented as superior to HDL cholesterol (HDL-C) in predicting cardiovascular disease risk. HDL functions relate to its composition. Compositional assays are easier to perform and standardize than functional tests and are more practical for routine testing. Our goal was to compare measurements of HDL particles by 5 different separation methods. METHODS: HDL subfractions were measured in 98 samples using vertical auto profiling (VAP), ion mobility (IM), nuclear magnetic resonance (NMR), native 2-dimensional gel electrophoresis (2D-PAGE), and pre-β1-ELISA...
December 4, 2017: Clinical Chemistry
Noora Hyttinen, Rasmus V Otkjær, Siddharth Iyer, Henrik Grum Kjaergaard, Matti P Rissanen, Paul O Wennberg, Theo Kurtén
High pressure anion chemical ionization is commonly used for the detection of neutral molecules in the gas phase. The detection efficiency in these measurements depends on how strongly the reagent ion binds to the neutral target molecule. We have calculated the binding strength of nitrate (NO3-), acetate (CH3C(O)O-), lactate (CH3CH(OH)C(O)O-), trifluoroacetate (CF3C(O)O-), trifluoromethanolate (CF3O-), bromide (Br-) and iodide (I-) reagent ions to ten different products derived from the OH radical initiated oxidation of butadiene...
December 4, 2017: Journal of Physical Chemistry. A
Mahroof Kalathingal, Takashi Sumikama, Toshifumi Mori, Shigetoshi Oiki, Shinji Saito
The β6.3-helical channel of the marine cytotoxic peptide, polytheonamide B (pTB), is examined in water, the POPC bilayer, and a 1 : 1 chloroform/methanol mixture using all-atom molecular dynamics simulations. The structures and fluctuations of the β6.3-helix of pTB are investigated in the three environments. The average structure of pTB calculated in the mixed solvent is in good agreement with the NMR-resolved structure in the mixed solvent, indicating the validity of the parameters used for the non-standard groups in pTB...
December 4, 2017: Physical Chemistry Chemical Physics: PCCP
Maryam Nabiyouni, Theresa Brückner, Huan Zhou, Uwe Gbureck, Sarit B Bhaduri
Magnesium ions are directly involved in numerous biological mechanisms; for example, they play an important part in the regulation of ion channels, DNA stabilization, enzyme activation and stimulation of cell growth and proliferation. This alkaline earth metal has gained great popularity in orthopedic applications in recent years. Magnesium-based bioceramics include a large group of magnesium containing compounds such as oxides, phosphates and silicates, that are involved in orthopedic applications like bone cements, bone scaffolds or implant coatings...
November 29, 2017: Acta Biomaterialia
Valérie Vallet, Ingmar Grenthe
The structure, chemical bonding, and thermodynamics of alkali ions in M[12-crown-4]+, M[15-crown-5]+, and M[18-crown-6]+, M[UO2(O2)(OH2)2]+4,5, and M[UO2(O2)(OH)(OH2)]n1-n (n = 4, 5) complexes have been explored by using quantum chemical (QC) calculations at the ab initio level. The chemical bonding has been studied in the gas phase in order to eliminate solvent effects. QTAIM analysis demonstrates features that are very similar in all complexes and typical for electrostatic M-O bonds, but with the M-O bonds in the uranyl peroxide systems about 20 kJ mol-1 stronger than in the corresponding crown ether complexes...
December 1, 2017: Inorganic Chemistry
S Redlberger, S Fischer, H Köhler, R Diller, P Reinhold
There is a paucity of published data reporting acid-base equilibrium in goats, and no information is available on how the acid-base complexity changes when suckling goat kids become ruminants. The aims of this study were to evaluate young healthy goats for age-related changes in serum proteins, metabolites, and electrolytes; differences in results when the Henderson-Hasselbalch equation or strong ion approaches were used were also assessed. To assess biological variability and reproducibility, two consecutive long-term studies, each lasting from the 6th to 56th week of life (wl), were performed in 15 (Study 1) and 10 (Study 2) animals...
November 2017: Veterinary Journal
Chan Yang, Zushi Huang, Mei Li, Xiangyang Feng, Xinghui Qiu
BACKGROUND: Anopheles sinensis is a major vector of malaria in China. The gamma-aminobutyric acid (GABA)-gated chloride channel, encoded by the RDL (Resistant to dieldrin) gene, is the important target for insecticides of widely varied structures. The use of various insecticides in agriculture and vector control has inevitably led to the development of insecticide resistance, which may reduce the control effectiveness. Therefore, it is important to investigate the presence and distribution frequency of the resistance related mutation(s) in An...
November 28, 2017: Malaria Journal
Heinz-Hermann Büker, Hans-Friedrich Grützmacher
The reactions of the [2-2]-paracyclophane 1 and the [2-2]-metaparacyclopane 2 in the gas phase after protonation by CI(CH4) or CI(I-C4H10) were studied by FT-ICR mass spectrometry. The ions C16H17+ produced in the external ion source of the FT-ICR instrument were transferred into the ICR cell containing the neutral reactant, and the reactions were analyzed measuring the efficiency of the transfer of a proton to a series of bases with known proton affinity and gas phase basicity as well as the efficiency of the ion-molecule reaction with ethyl vinyl ether...
December 2017: European Journal of Mass Spectrometry
Rebekka Gulde, Sabine Anliker, Hans-Peter Kohler, Kathrin Fenner
To optimize removal of polar organic micropollutants from the water cycle, understanding the processes during activated sludge treatment is essential. In this study, we hypothesize that aliphatic amines, which are highly abundant amongst organic micropollutants, are removed from the water phase in activated sludge through ion trapping in protozoa. In ion trapping, which has been extensively investigated in medical research, the neutral species of amine-containing compounds diffuse through the cell membrane and further into acidic vesicles present in eukaryotic cells such as protozoa...
November 28, 2017: Environmental Science & Technology
Faiz Ullah Shah, Oleg I Gnezdilov, Rashi Gusain, Andrei Filippov
Ion transport behaviour of halogen-free hybrid electrolytes for lithium-ion batteries based on phosphonium bis(salicylato)borate [P4,4,4,8][BScB] ionic liquid mixed with diethylene glycol dibutyl ether (DEGDBE) is investigated. The Li[BScB] salt is dissolved at different concentrations in the range from 0.15 mol kg-1 to 1.0 mol kg-1 in a mixture of [P4,4,4,8][BScB] and DEGDBE in 1:5 molar ratio. The ion transport properties of the resulting electrolytes are investigated using viscosity, electrical impedance spectroscopy and pulsed-Field Gradient (PFG) NMR...
November 27, 2017: Scientific Reports
Arezoo Dadrasnia, Mohd Sofian Azirun, Salmah Binti Ismail
BACKGROUND: When the unavoidable waste generation is considered as damaging to our environment, it becomes crucial to develop a sustainable technology to remediate the pollutant source towards an environmental protection and safety. The development of a bioengineering technology for highly efficient pollutant removal is this regard. Given the high ammonia nitrogen content and chemical oxygen demand of landfill leachate, Bacillus salmalaya strain 139SI, a novel resident strain microbe that can survive in high ammonia nitrogen concentrations, was investigated for the bioremoval of ammonia nitrogen from landfill leachate...
November 28, 2017: BMC Biotechnology
Songchu Li, Lixin Yu, Xiaoqin Man, Jianlin Zhong, Wei Sun
In this paper, MAl2 Six O2x+4 :Eu2+ /Eu3+ (Eu2+ + Eu3+ = 2%, molar ratio; M = Mg, Ca, Sr, Ba; x = 0, 0.5, 1, 1.5, 2) phosphors with different SiO2 concentrations (the ratio of SiO2 to MAl2 O4 is n%, n = 0, 50, 100, 150, 200, respectively) were prepared by high-temperature solid-state reaction under atmospheric air conditions. Their structures and photoluminescent properties were systematically researched. The results indicate that Eu3+ ions have been reduced and Eu2+ ions are obtained in air through the self-reduction mechanism...
November 27, 2017: Luminescence: the Journal of Biological and Chemical Luminescence
Liyang Shi, Yu Zhang, Dmitri Ossipov
In situ cross-linked hyaluronan (HA) hydrogels with different capacities for biomineralization were prepared and their enzymatic degradation was monitored. Covalent incorporation of bisphosphonates (BPs) into HA hydrogel results in the increased stiffness of the hydrogel in comparison with the unmodified HA hydrogel of the same cross-linking density. The rate of enzymatic degradation of HABP hydrogel was significantly lower than the rate of degradation of control HA hydrogel in vitro. This effect is observed only in the presence of calcium ions that strongly bind to the matrix-anchored BP groups and promote further mineralization of the matrix...
November 27, 2017: Biopolymers
Maher Mahmoud Al-Dabbas
The antioxidant activities of methanol (M), ethyl acetate (E) and hexane (H) extracts from leaves (L) and seeds (S) of Moringa (Moringa peregrina) were evaluated using different model systems in vitro. Free radical scavenging activities were assessed by measuring the scavenging activities of leaves and seeds different polar extracts separately using ABTS, Hydroxyl (OH) and DPPH radicals. Effect of extracts on ferrous ions chelating ability and total antioxidant capacity were also investigated for each extract...
November 2017: Pakistan Journal of Pharmaceutical Sciences
Nanyan Weng, Haibo Jiang, Wen-Xiong Wang
Determining the in situ localization of trace elements at high lateral resolution levels in the biological system is very challenging, but critical for our understanding of metal sequestrationa and detoxification. Here, the cellular and subcellular distributions of Cu and Zn in contaminated oysters of Crassostrea hongkongensis were for the first time mapped using nanoscale secondary ion mass spectrometry (nanoSIMS). Three types of metal-containing cells were revealed in the gill and mantle of oysters, including Cu-specific hemocytes, Cu and Zn-containing granular hemocytes, and Cu and Zn-containing calcium cells...
November 27, 2017: Environmental Science & Technology
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"