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https://www.readbyqxmd.com/read/29783198/toxicity-assessment-of-metal-oxide-nano-pollutants-on-tomato-solanum-lycopersicon-a-study-on-growth-dynamics-and-plant-cell-death
#1
Bilal Ahmed, Mohammad Saghir Khan, Javed Musarrat
The present study for the first time demonstrated the interactions of metal oxide (MO) nano-pollutants (CuO and Al2 O3 -NPs) with tissues and cellular DNA of tomato plants grown in soil sand: silt: clay (667:190:143) and Hoagland-hydroponic system and assessed the hazardous effects of NPs on cell physiology and biochemistry. Results of SEM equipped with EDX revealed attachment of variably shaped CuO-NPs (18 nm) and Al2 O3 -NPs (21 nm) on roots, and internalization followed by translocation in plants by ICP-MS and TEM...
May 18, 2018: Environmental Pollution
https://www.readbyqxmd.com/read/29783142/assessment-of-microbial-products-in-the-biosorption-process-of-cu-ii-onto-aerobic-granular-sludge-extracellular-polymeric-substances-contribution-and-soluble-microbial-products-release
#2
Linxian Huang, Meilin Li, Guangchao Si, Jinglin Wei, Huu Hao Ngo, Wenshan Guo, Weiying Xu, Bin Du, Qin Wei, Dong Wei
In the present study, the responses of microbial products in the biosorption process of Cu(II) onto aerobic granular sludge were evaluated by using batch and spectroscopic approaches. Batch experimental data showed that extracellular polymeric substances (EPSs) contributed to Cu(II) removal from an aqueous solution, especially when treating low metal concentrations, whereas soluble microbial products (SMPs) were released under the metal stress during biosorption process. A three-dimensional excitation-emission matrix (3D-EEM) identified four main fluorescence peaks in the EPS, i...
May 18, 2018: Journal of Colloid and Interface Science
https://www.readbyqxmd.com/read/29782948/dendritic-peg-outer-shells-enhance-serum-stability-of-polymeric-micelles
#3
Hao-Jui Hsu, Yanxiao Han, Michael Cheong, Petr Král, Seungpyo Hong
A higher surface density of poly(ethylene glycol) (PEG) on polymeric micelles enhances their stability in serum, leading to improved plasma circulation. To obtain fundamental, mechanistic understanding of the PEG effect associated with polymeric architecture/configuration, we have synthesized PEGylated dendron-based copolymers (PDCs) and linear block copolymers (LBCs) with similar molecular weights. These copolymers formed dendron (hyperbranched) and linear micelles, respectively, which were compared in terms of their stabilities in serum, micelle-serum protein interactions, and in vivo biodistributions...
May 18, 2018: Nanomedicine: Nanotechnology, Biology, and Medicine
https://www.readbyqxmd.com/read/29782823/changing-the-site-energy-of-per-614-in-the-peridinin-chlorophyll-a-protein-does-not-alter-its-capability-of-chlorophyll-triplet-quenching
#4
Alessandro Agostini, Jens Niklas, Tim Schulte, Marilena Di Valentin, Marco Bortolus, Eckhard Hofmann, Wolfgang Lubitz, Donatella Carbonera
The peridinin-chlorophyll-a protein (PCP) is a water-soluble light harvesting protein of the dinoflagellate Amphidinium carterae, employing peridinin (Per) as the main carotenoid to fulfil light harvesting and photo-protective functions. Per molecules bound to the protein experience specific molecular surroundings which lead to different electronic and spectral properties. In the refolded N89 L variant PCP (N89 L-RFPCP) a significant part of the intensity on the long wavelength side of the absorption spectrum is shifted to shorter wavelengths due to a significant change in the Per-614 site energy...
May 18, 2018: Biochimica et Biophysica Acta
https://www.readbyqxmd.com/read/29782699/endoplasmic-reticulum-targeted-fluorescent-nanodot-with-large-stokes-shift-for-vesicular-transport-monitoring-and-long-term-bioimaging
#5
Leilei Shi, Xihui Gao, Wangzhang Yuan, Li Xu, Hongping Deng, Chenwei Wu, Jiapei Yang, Xin Jin, Chuan Zhang, Xinyuan Zhu
Herein, a highly stable aggregation-induced emission (AIE) fluorescent nanodot assembled by an amphiphilic quinoxalinone derivative-peptide conjugate, namely Quino-1-Fmoc-RACR (also termed as Q1-PEP), which exhibits large Stokes shift and an endoplasmic reticulum (ER)-targeting capacity for bioimaging is reported. It is found that the resulting nanodot can effectively enter the ER with high fluorescent emission. As the ER is mainly involved in the transport of synthesized proteins in vesicles to the Golgi or lysosomes, the Q1-PEP nanodot with ER-targeting capacity can be used to monitor vesicular transport inside the cells...
May 21, 2018: Small
https://www.readbyqxmd.com/read/29782149/cryptophane-nanoscale-assemblies-expand-129xe-nmr-biosensing
#6
Serge D Zemerov, Benjamin W Roose, Mara L Greenberg, Yanfei Wang, Ivan J Dmochowski
Cryptophane-based biosensors are promising agents for the ultrasensitive detection of biomedically relevant targets via 129Xe NMR. Dynamic light scattering revealed that cryptophanes form water-soluble aggregates of tens-to-hundreds of nanometers in size. Acridine orange fluorescence quenching assays allowed quantitation of aggregation state, with critical concentration rang-ing from 200 to 600 nM, depending on the cryptophane species in solution. Addition of excess carbonic anhydrase (CA) pro-tein target to a benzenesulfonamide-functionalized cryptophane biosensor (C8B) led to C8B disaggregation and produced the expected 1:1 C8B-CA complex...
May 21, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29781279/synthesis-of-cyclobutadienoid-fused-phenazines-with-strongly-modulated-degrees-of-antiaromaticity
#7
Yew Chin Teo, Zexin Jin, Yan Xia
The streamlined synthesis of a series of regioisomeric azaacene analogues containing fused phenazine and antiaromatic cyclobutadienoids (CBDs), using a catalytic arene-oxanorbornene annulation, followed by aromatization is reported. Controlling the fusion patterns allowed strong modulation of local antiaromaticity. Enhancing antiaromaticity in these regioisomeric azaacenes led to stabilized LUMO, reduced band gap, and quenched fluorescence. This synthetic strategy provides a facile means to fuse CBDs with variable degrees of antiaromaticity onto N-heteroarenes to tune their optoelectronic properties...
May 21, 2018: Organic Letters
https://www.readbyqxmd.com/read/29780999/iphone-imaged-and-cell-powered-electrophoresis-titration-chip-for-the-alkaline-phosphatase-assay-in-serum-by-the-moving-reaction-boundary
#8
Xin-Yu Cao, Fan-Zhi Kong, Qiang Zhang, Wei-Wen Liu, Xiao-Ping Liu, Guo-Qing Li, Ran Zhong, Liu-Yin Fan, Hua Xiao, Cheng-Xi Cao
As a vital enzyme, alkaline phosphatase (ALP) has great clinical significance in diagnoses of bone or liver cancer, bone metastases, rickets, and extrahepatic biliary obstruction. However, there is still no really portable chip for the ALP assay in blood. Herein, a simple electrophoresis titration (ET) model was developed for ALP detection via a moving reaction boundary (MRB). In the model, ALP catalyzed the dephosphorylation of a 4-methylumbelliferyl phosphate disodium salt (4-MUP) substrate in the cathode well to 4-methylumbelliferone ([4-MU]-) with a negative charge and blue fluorescence under UV excitation...
May 21, 2018: Lab on a Chip
https://www.readbyqxmd.com/read/29780469/tailored-metastable-ce-zr-oxides-with-highly-distorted-lattice-oxygen-for-accelerating-redox-cycles
#9
Zhe Zhang, Jiafeng Yu, Jixin Zhang, Qingjie Ge, Hengyong Xu, Felix Dallmann, Roland Dittmeyer, Jian Sun
Ceria-based catalysts are widely used in oxidation or oxidation-reduction reactions in the field of environmental science. Their catalytic functions are determined by their ability to exchange oxygen species with oxidants. The enhancement of oxygen release is desired since it is often the rate-determining step in redox cycles. Herein, we developed a lattice oxygen distortion method to enhance oxygen activation by quenching the Ce-Zr oxide nanoparticles formed from an extremely high temperature. This process can ensure the formation of solid solutions as well as avoiding atomic rearrangement during calcination, retaining the lattice oxygen at a metastable and disordered state without vacancies...
April 7, 2018: Chemical Science
https://www.readbyqxmd.com/read/29780460/redox-and-photocatalytic-properties-of-a-ni-ii-complex-with-a-macrocyclic-biquinazoline-mabiq-ligand
#10
Michael Grübel, Irene Bosque, Philipp J Altmann, Thorsten Bach, Corinna R Hess
We present a late, first row transition metal photosensitizer that promotes photocatalytic C-C bond formation. The title compound, [Ni(Mabiq)]OTf, as well as its one-electron reduced form, Ni(Mabiq), were synthesized and molecular structures of both were obtained. The electronic structure of the reduced complex additionally was characterized by spectroscopic and DFT computational methods. Notably, [NiII (Mabiq)]OTf is photoactive: reduction of the compound was achieved photochemically upon irradiation at λ = 457 nm and reductive quenching by NEt3 ...
April 7, 2018: Chemical Science
https://www.readbyqxmd.com/read/29779192/impact-of-weak-water-deficit-on-growth-photosynthetic-primary-processes-and-storage-processes-in-pine-and-spruce-seedlings
#11
Ilya E Zlobin, Yury V Ivanov, Alexander V Kartashov, Boris A Sarvin, Andrey N Stavrianidi, Vladimir D Kreslavski, Vladimir V Kuznetsov
We investigated the influence of 40 days of drought on growth, storage processes and primary photosynthetic processes in 3-month-old Scots pine and Norway spruce seedlings growing in perlite culture. Water stress significantly affected seedling water status, whereas absolute dry biomass growth was not substantially influenced. Water stress induced an increase in non-structural carbohydrate content (sugars, sugar alcohols, starch) in the aboveground part of pine seedlings in contrast to spruce seedlings. Due to the relatively low content of sugars and sugar alcohols in seedling organs, their expected contribution to osmotic potential changes was quite low...
May 19, 2018: Photosynthesis Research
https://www.readbyqxmd.com/read/29779060/three-way-dna-junction-based-platform-for-ultra-sensitive-fluorometric-detection-of-multiple-metal-ions-as-exemplified-for-cu-ii-mg-ii-and-pb-ii
#12
Wen Yun, Xiaoqing Du, Junsheng Liao, Ge Sang, Lin Chen, Ning Li, Lizhu Yang
A DNA-based fluorometric method is described for simultaneous determination of multiple metal ions. It is based on recycling cleavage of hairpins by using a three-way DNA junction structure. Three DNA sequences containing a binding region and an enzyme-strand (E-DNA) region are hybridized to form a three-way DNA junction. The enzyme strand regions at the end of the DNA sequence binds to the substrate sequence (S-DNA) at the loop of the hairpin to form typical DNAzyme structures. In the presence of analyte metal ions, the DNAzyme structure thus formed cleaves the loop of hairpins...
May 20, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/29777941/characterization-of-the-binding-of-a-novel-antitumor-drug-ibrutinib-with-human-serum-albumin-insights-from-spectroscopic-calorimetric-and-docking-studies
#13
Bin Tang, Peixiao Tang, Jiawei He, Hongqin Yang, Hui Li
Ibrutinib (IBR) is a novel Bruton's tyrosine kinase inhibitor and shows good efficacy for several B-cell malignancies. In the current study, the molecular mechanism of the interaction between IBR and the transport protein human serum albumin (HSA) was ascertained by spectroscopic, calorimetric, and docking studies. Detailed investigations on affinity parameter, binding model, conformational change, and site selectivity were implemented by receptor-based and ligand-based analysis. An unusual fluorescence co-quenching (mutual quenching) was observed in the binding of IBR to HSA, followed by a static mechanism...
May 16, 2018: Journal of Photochemistry and Photobiology. B, Biology
https://www.readbyqxmd.com/read/29777936/fast-synthesis-of-porous-copper-nanoclusters-for-fluorescence-detection-of-iron-ions-in-water-samples
#14
Yihong Huang, Hanqiang Zhang, Xiaofen Xu, Jiangcong Zhou, Fenfen Lu, Zhusen Zhang, Zhibiao Hu, Jiangshui Luo
Copper nanoclusters (Cu NCs) have attracted great research interest in recent years owing to its unique physical, electrical and optical properties. Macromolecules have been widely used as templates to synthesize fluorescent Cu NCs. In this study, a simple method for synthesis of albumin chicken egg capped porous copper nanoclusters (p-Cu NCs) was developed for the first time. The obtained p-Cu NCs exhibited intense emission and excitation peaks at 280 nm and 340 nm, respectively. Besides, the p-Cu NCs fluorescence probe could be quenched by Fe3+ ions in aqueous solutions...
May 9, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29777928/binding-studies-of-triclocarban-with-bovine-serum-albumin-insights-from-multi-spectroscopy-and-molecular-modeling-methods
#15
Jiao Guan, Xin Yan, Yajing Zhao, Yinhe Sun, Xin Peng
The antimicrobial triclocarban (TCC) is frequently found in various personal care products (PCPs), and recent studies have demonstrated that it shows a high unintended biological activity on humans and wildlife. To evaluate the toxicity of TCC at the protein level, the effect of TCC on bovine serum albumin (BSA) has been investigated using various spectroscopic methods in combination with molecular modeling. Analysis of fluorescence quenching data of BSA revealed the formation of a ground state BSA-TCC complex with a binding constant of 2...
May 9, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
https://www.readbyqxmd.com/read/29777876/poly-adenine-mediated-fluorescent-spherical-nucleic-acid-probes-for-live-cell-imaging-of-endogenous-tumor-related-mrna
#16
Dan Zhu, Dongxia Zhao, Jiaxuan Huang, Yu Zhu, Jie Chao, Shao Su, Jiang Li, Lihua Wang, Jiye Shi, Xiaolei Zuo, Lixing Weng, Qian Li, Lianhui Wang
Identification of tumor-related mRNA in living cells hold great promise for early cancer diagnosis and pathological research. Herein, we present poly-adenine (polyA)-mediated fluorescent spherical nucleic acid (FSNA) probes for intracellular mRNA detection with regulable sensitivities by programmably adjusting the loading density of DNA on gold nano-interface. Gold nanoparticles (AuNPs) functionalized with polyA-tailed recognition sequences were hybridized to fluorescent "reporter" strands to fabricate fluorescence-quenched FSNA probes...
May 16, 2018: Nanomedicine: Nanotechnology, Biology, and Medicine
https://www.readbyqxmd.com/read/29777812/exploring-the-intermolecular-interactions-and-contrasting-binding-of-flufenamic-acid-with-hemoglobin-and-lysozyme-a-biophysical-and-docking-insight
#17
Sameer Shakeel Ansari, Imtiyaz Yousuf, Farukh Arjmand, Mohammad Khursheed Siddiqi, Saeeda Naqvi
The intermolecular interaction of flufenamic acid (Hfluf) with two model proteins i.e., hemoglobin and lysozyme was explored using fluorescence, UV-vis, circular dichroism, DLS, and molecular docking techniques. The corroborative spectroscopic techniques suggested efficient binding of Hfluf to both the proteins. The S-V plot in Hb-Hfluf system showed positive deviation highlighting the presence of both static and dynamic quenching. Hence, ground state complex model and sphere of action quenching model were used for the study...
May 16, 2018: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/29777430/the-artificial-humic-substance-hs1500-does-not-inhibit-photosynthesis-of-the-green-alga-desmodesmus-armatus-in-vivo-but-interacts-with-the-photosynthetic-apparatus-of-isolated-spinach-thylakoids-in-vitro
#18
Matthias Gilbert, Hanno Bährs, Christian E W Steinberg, Christian Wilhelm
Humic substances (HSs) can influence the growth and composition of freshwater phytoplankton assemblage. Since HSs contain many phenolic and quinonic moieties and cause growth reductions in eco-physiological field experiments, HSs are considered photosystem II herbicides. To test this specific mode of action in vivo and in vitro, respectively, we used intact cells of the green alga Desmodesmus armatus, as well as thylakoids isolated from spinach (Spinacia oleracea) as a model system for the green algal chloroplast...
May 18, 2018: Photosynthesis Research
https://www.readbyqxmd.com/read/29777313/gold-nanocluster-based-ratiometric-fluorescent-probes-for-hydrogen-peroxide-and-enzymatic-sensing-of-uric-acid
#19
Dongqin Yang, Minchuan Luo, Junwei Di, Yifeng Tu, Jilin Yan
A method is described for ratiometric fluorometric assays of H2 O2  by using two probes that have distinct response profiles. Under the catalytic action of ferrous ion, the 615 nm emission of protein-stabilized gold nanoclusters (under 365 nm photoexcitation) is quenched by H2 O2 , while an increased signal is generated with a peak at 450 nm by oxidizing coumarin with the H2 O2 /Fe(II) system to form a blue emitting fluorophore. These decrease/increase responses give a ratiometric signal. The ratio of the fluorescences at the two peaks are linearly related to the concentration of H2 O2 in the range from 0...
May 18, 2018: Mikrochimica Acta
https://www.readbyqxmd.com/read/29776122/glassy-phase-in-quenched-disordered-crystalline-membranes
#20
O Coquand, K Essafi, J-P Kownacki, D Mouhanna
We investigate the flat phase of D-dimensional crystalline membranes embedded in a d-dimensional space and submitted to both metric and curvature quenched disorders using a nonperturbative renormalization group approach. We identify a second-order phase transition controlled by a finite-temperature, finite-disorder fixed point unreachable within the leading order of ε=4-D and 1/d expansions. This critical point divides the flow diagram into two basins of attraction: that associated with the finite-temperature fixed point controlling the long-distance behavior of disorder-free membranes and that associated with the zero-temperature, finite-disorder fixed point...
March 2018: Physical Review. E
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