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strong ion

Akello J Agwa, Yen-Hua Huang, David J Craik, Sónia T Henriques, Christina I Schroeder
Spider gating modifier toxins (GMTs) are potent modulators of voltage-gated ion channels and have thus attracted attention as drug leads for several pathophysiological conditions. GMTs contain three disulfide bonds organized in an inhibitory cystine knot, which putatively confers them with high stability; however, thus far, there has not been a focused study to establish the stability of GMTs in physiological conditions. We examined the resistance of five GMTs including GpTx-1, HnTx-IV, HwTx-IV, PaurTx-3 and SgTx-1, to pH, thermal and proteolytic degradation...
August 12, 2017: Toxins
Chundong Wang, Jianjun Jiang, Yunjun Ruan, Xiang Ao, Kostya Ken Ostrikov, WenJun Zhang, Jian Lu, Yang Yang Li
Herein, MoO2 quantum dots (QDs, <5 nm) are synthesized through one-step solvothermal process. MoO2 QDs-bonded graphene sheets (MoO2-QDs@RGO) are facilely produced, which can be further converted through sulfidation into MoS2 nanoparticles-bonded graphene sheets (MoS2-NPs@RGO). The novel MoO2-QDs@RGO electrodes demonstrate exceptionally attractive lithium storage capability (e.g., 1257 mAh g-1 at 100 mA g-1, being close to the highest values ever reported for MoO2-based LIB electrode), rate capability, and cycle stability...
August 14, 2017: ACS Applied Materials & Interfaces
Wei Zhou, Chenlu Wang, Yikun Liu, Wenpeng Zhang, Zilin Chen
Layered double hydroxides (LDHs) are ideal sorbents for solid phase extraction (SPE) because of the excellent ion exchange capacity and high specific surface area. However, difficult elution of the analytes from the LDHs is a problem due to the strong ionic interaction between anions and LDHs. High concentrated NaOH solution is employed to elute the sample, but it not suitable for analyzing by HPLC. To solve this problem, a simple acid-base neutralization method was proposed after elution, and then the neutral samples were directly injected to HPLC for analysis...
July 15, 2017: Journal of Chromatography. A
Claudia Wilke, Astrid Barkleit, Thorsten Stumpf, Atsushi Ikeda-Ohno
In case radioactive materials are released into the environment, their incorporation into our digestive system would be a significant concern. Trivalent f-elements, i.e., trivalent actinides and lanthanides, could potentially represent a serious health risk due to their chemo- and radiotoxicity, nevertheless the biochemical behavior of these elements are mostly unknown even to date. This study, therefore, focuses on the chemical speciation of trivalent f-elements in the human gastrointestinal tract. To simulate the digestive system artificial digestive juices (saliva, gastric juice, pancreatic juice and bile fluid) were prepared...
August 4, 2017: Journal of Inorganic Biochemistry
Jin Wang, Pei Cai, Xue-Lian Yang, Fan Li, Jia-Jia Wu, Ling-Yi Kong, Xiao-Bing Wang
By using fragments endowed with interesting and complementary properties for the treatment of Alzheimer's disease (AD), a novel series of cinnamamide-dibenzylamine hybrids have been designed, synthesized, and evaluated biologically. In vitro assay indicated that most of the target compounds exhibited a significant ability to inhibit ChEs, strong potency inhibitory of self-induced β-amyloid (Aβ) aggregation and to act as potential antioxidants and biometal chelators. A Lineweaver-Burk plot and molecular modeling study showed that compound 7f targeted both the CAS and PAS of AChE...
August 1, 2017: European Journal of Medicinal Chemistry
Wen Lei, Weiping Xiao, Jingde Li, Gaoran Li, Zexing Wu, Cuijuan Xuan, Dan Luo, Ya-Ping Deng, Deli Wang, Zhongwei Chen
Inspired by the excellent absorption capability of sponge like bacterial cellulose (BC), ultra-high content of N (21.2 at%) doped three-dimensional hierarchical porous carbon fiber (NDCF) is synthesized by an adsorption-swelling strategy using BC as the carbonaceous material. When used as sodium-ion battery anode materials, the NDCF delivers a high reversible capacity of 86.2 mAh g-1 even after 2000 cycles at a high current density of 10.0 A g-1. It is proposed that the excellent Na+ storage performance is mainly contributed by the defective surface of the NDCF created by the high content of N doping...
August 11, 2017: ACS Applied Materials & Interfaces
Mary Jo Weiss-Errico, Ion Ghiviriga, Kevin E O'Shea
Legacy perfluoroalkyl substances (PFASs) are known environmental pollutants with serious adverse health effects. Perfluoroethercarboxylic acids (PFECAs), emerging PFASs now being substituted for legacy PFASs, have recently been detected in the environment. Cyclodextrins (CDs) have been proposed as agents for the remediation of problematic pollutants, including legacy PFASs. The current study uses (19)F NMR spectroscopy to measure the complexation of mono-, di-, and triether PFECAs by CDs for eventual environmental applications...
August 11, 2017: Journal of Physical Chemistry. B
Biplab Bhattacharyya, Alka Sharma, Bhavesh Sinha, Kunjal Shah, Suhas Jejurikar, T D Senguttuvan, Sudhir Husale
We report the experimental observation of variable range hopping conduction in focused-ion-beam (FIB) fabricated ultra-narrow nanowires of topological insulator (Bi2Se3). The value of the exponent (d + 1)(-1) in the hopping equation was extracted as [Formula: see text]for different widths of nanowires, which is the proof of the presence of Efros-Shklovskii hopping transport mechanism in a strongly disordered system. High localization lengths (0.5 nm, 20 nm) were calculated for the devices. A careful analysis of the temperature dependent fluctuations present in the magnetoresistance curves, using the standard Universal Conductance Fluctuation theory, indicates the presence of 2D topological surface states...
August 10, 2017: Scientific Reports
Christopher Clarke, Stephane R Gross, Thamir M Ismail, Philip S Rudland, Morteta Al-Medhtiy, Michael Santangeli, Roger Barraclough
S100P protein in human breast cancer cells is associated with reduced patient survival and, in a model system of metastasis, it confers a metastatic phenotype upon benign mammary tumour cells. S100P protein possesses a C-terminal lysine residue. Using a multiwell in vitro assay, S100P is now shown for the first time to exhibit a strong, C-terminal-lysine-dependent activation of tissue plasminogen activator (tPA), but not of urokinase-catalysed plasminogen activation.  The presence of 10 mM calcium ions stimulates tPA activation of plasminogen 2-fold in an S100P-dependent manner...
August 10, 2017: Biochemical Journal
Juliane F Ferreira, Izilda A Bagatin
A new quinoline-amide calix[4]arene 3-receptor for detection of hazardous anions and cations have been synthesized. The 3-receptor was examined for its sensing properties towards several different anions (Cr2O7(2), SCN(-), F(-), Cl(-), NO3) and metal ions (Hg(2+), Cd(2+), Ag(+)) by UV-vis and fluorescence spectroscopies. It was detected that the 3-receptor has only sensing ability for Cr2O7(2) and Hg(2+) ions, resulting in the association constants higher for Cr2O7(2) than to the Hg(2+) ions. High selectivity towards Cr2O7(2) were also observed by fluorescence measurement among other ions (F(-), Cl(-), SCN(-), Hg(2+), Cd(2+), Ag(+)) with a low limit of detection (7...
August 3, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Nicholas F Lahens, Emanuela Ricciotti, Olga Smirnova, Erik Toorens, Eun Ji Kim, Giacomo Baruzzo, Katharina E Hayer, Tapan Ganguly, Jonathan Schug, Gregory R Grant
BACKGROUND: Though Illumina has largely dominated the RNA-Seq field, the simultaneous availability of Ion Torrent has left scientists wondering which platform is most effective for differential gene expression (DGE) analysis. Previous investigations of this question have typically used reference samples derived from cell lines and brain tissue, and do not involve biological variability. While these comparisons might inform studies of tissue-specific expression, marked by large-scale transcriptional differences, this is not the common use case...
August 10, 2017: BMC Genomics
Tao Wang, Chenglong Hou, Kun Ge, Klaus S Lackner, Xiaoyang Shi, Jun Liu, Mengxiang Fang, Zhongyang Luo
A polymeric ionic liquid (PIL), with quaternary ammonium ions attached to the polymer matrix, displays CO2 affinity controlled by moisture. This finding led to the development of moisture swing absorption (MSA) for direct air capture (DAC) of CO2. This work aims to elucidate the role of water in MSA. For some humidity range, CO2 absorption is an endothermic process associated with concurrent dehydration of the sorbent. The thermodynamic behavior of water indicates a decreased hydrophilicity of the PIL as the mobile anion transforms from CO32- to HCO3- during CO2 absorption...
August 10, 2017: Journal of Physical Chemistry Letters
Siddharth Iyer, Xucheng He, Noora Hyttinen, Theo Kurtén, Matti P Rissanen
The HO2 radical is an important atmospheric molecule that can potentially influence the termination of autoxidation processes of volatile organic compounds (VOCs) that lead to the formation of highly oxygenated multifunctional compounds (HOMs). In this work, we demonstrate the direct detection of the HO2 radical using an iodide-based chemical ionization mass spectrometer (iodide-CIMS). Expanding on the previously established correlation between molecule-iodide binding enthalpy and iodide-CIMS instrument sensitivity, the experimental detection of the HO2 radical was preceded by the quantum chemical calculation of the HO2*I(-) cluster (PBE/aug-cc-pVTZ-PP level), which showed a reasonably strong binding enthalpy of 21...
August 10, 2017: Journal of Physical Chemistry. A
Haizhong Guo, Qingqing Li, Zhengzhong Yang, Kui-Juan Jin, Chen Ge, Lin Gu, Xu He, Xiaolong Li, Ruiqiang Zhao, Qian Wan, Jiesu Wang, Meng He, Can Wang, Huibin Lu, Yuping Yang, Guozhen Yang
Artificial superlattices constructed with ferromagnetic La0.7Sr0.3MnO3 layer and ferroelectric Ba0.7Sr0.3TiO3 layer were designed and fabricated on SrTiO3 substrates. An epitaxial growth with sharp interfaces between La0.7Sr0.3MnO3 and Ba0.7Sr0.3TiO3 layers was confirmed by scanning transmission electron microscopy and x-ray diffraction. An unambiguous charge transfer involving an electron transferring from the La0.7Sr0.3MnO3 layers to Ba0.7Sr0.3TiO3 layers (Mn(3+)→Mn(4+); Ti(4+)→Ti(3+)) across the interface were resolved by electron energy loss spectra analysis...
August 9, 2017: Scientific Reports
Michael W Risør, Dennis W Juhl, Morten Bjerring, Joachim Mathiesen, Jan J Enghild, Niels C Nielsen, Daniel E Otzen
Many proteins and peptides self-associate into highly ordered and structurally similar amyloid cross-β aggregates. This fibrillation is critically dependent on properties of the protein and the surrounding environment that alter kinetic and thermodynamic equilibria. Here, we report on dominating surface and solution effects on the fibrillogenic behavior and amyloid assembly of the C-36 peptide, a circulating bioactive peptide from the α1-antitrypsin serine protease inhibitor. C-36 converts from an unstructured peptide to mature amyloid twisted-ribbon fibrils over a few hours when incubated on polystyrene plates under physiological conditions through a pathway dominated by surface-enhanced nucleation...
August 8, 2017: Biophysical Journal
Zhong-Liang Zhang, Yuan-Yan Wu, Kun Xi, Jian-Ping Sang, Zhi-Jie Tan
Ion-mediated interaction between DNAs is essential for DNA condensation, and it is generally believed that monovalent and nonspecifically binding divalent cations cannot induce the aggregation of double-stranded (ds) DNAs. Interestingly, recent experiments found that alkaline earth metal ions such as Mg(2+) can induce the aggregation of triple-stranded (ts) DNAs, although there is still a lack of deep understanding of the surprising findings at the microscopic level. In this work, we employed all-atom dynamic simulations to directly calculate the potentials of mean force (PMFs) between tsDNAs, between dsDNAs, and between tsDNA and dsDNA in Mg(2+) solutions...
August 8, 2017: Biophysical Journal
L Sánchez-García, M O Ramírez, C Tserkezis, R Sole, J J Carvajal, M Aguiló, F Díaz, L E Bausá
Increasing Yb(3+) absorption efficiency is currently desired in a number of applications including bio-imaging, photovoltaics, near infrared driven photocatalysis or ultra-short pulsed solid-state lasers. In this work, silver nanoparticles, which are connected forming disordered networks, have been self-assembled on Yb(3+) doped RbTiOPO4 crystals to produce a remarkable enhancement of Yb(3+) absorption, and hence in the photoluminescence of this ion. The results are interpreted taking into account the near-field response of the plasmonic networks, which display strong amplification of the electric field at the maximum of Yb(3+) excitation at around 900 nm, together with the anisotropic character of the Yb(3+) transitions in RbTiOPO4...
August 9, 2017: Nanoscale
Ruaridh Forbes, Andrey E Boguslavskiy, Iain Wilkinson, Jonathan G Underwood, Albert Stolow
We present an experimental femtosecond time-resolved study of the 399 nm excited state dynamics of nitrogen dioxide using channel-resolved above threshold ionization (CRATI) as the probe process. This method relies on photoelectron-photoion coincidence and covariance to correlate the strong-field photoelectron spectrum with ionic fragments, which label the channel. In all ionization channels observed, we report apparent oscillations in the ion and photoelectron yields as a function of pump-probe delay. Further, we observe the presence of a persistent, time-invariant above threshold ionization comb in the photoelectron spectra associated with most ionization channels at long time delays...
August 7, 2017: Journal of Chemical Physics
Sen Yang, Jun Qian, Liangju Kuang, Daoben Hua
It is strategically important to recycle uranium from radioactive liquid wastes for future uranium supply of nuclear energy. However, it is still a challenge to adsorb uranium selectively from highly acidic and radioactive waste. In this paper, we report a novel strategy for effective uranium removal from highly acidic and radioactive media by surface ion-imprinted mesoporous silica sorbent. The sorbent was successfully synthesized by a co-condensation method with uranyl as the template ion and diethylphosphatoethyltriethoxysilane (DPTS) as the functional ligands...
August 7, 2017: ACS Applied Materials & Interfaces
Claudia Caddeo, Maria Ilenia Saba, Simone Meloni, Alessio Filippetti, Alessandro Mattoni
The origin of the dissolution of MAPI crystals in liquid water is clarified by finite temperature molecular dynamics by developing a MYP-based force field (MYP1) for water-MAPI systems. It is found a thermally activated process with an energy barrier of 0.36 eV consisting of a layer by layer degradation with generation of inorganic PbI films and solvation of MA and I ions. We rationalize the effect of water on MAPI by identifying a transition from a reversible absorption and diffusion in presence of vapor, to the irreversible destruction of the crystal lattice in liquid due to a cooperative action of water molecules...
August 7, 2017: ACS Nano
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