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Meng-Lei Xu, Yu Gao, Yali Li, Xueliang Li, Huanjie Zhang, Xiao Xia Han, Bing Zhao, Liang Su
Glyphosate is one of the most commonly-used and non-selective herbicides in agriculture, which may directly pollute the environment and threaten human health. A simple and effective approach to assessment of its damage to the natural environment is thus quite necessary. However, traditional chromatography-based detection methods usually suffer from complex pretreatment procedures. Herein, we propose a simple and sensitive method for the determination of glyphosate by combining ninhydrin reaction and surface-enhanced Raman scattering (SERS) spectroscopy...
January 5, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Akihiro Ohtake, Shunji Goto, Jun Nakamura
We have systematically studied the atomic structure and electronic properties of the Se-treated GaAs(111)B surface using scanning tunneling microscopy, reflection high-energy electron diffraction, x-ray photoelectron spectroscopy, and first-principles calculations. We have found that Se atoms substitute [Formula: see text] monolayer of As atoms at the outermost layer of the ideal (111)B surface. Charge transfer from Se to As eliminates all of unsaturated dangling bonds, so that the surface is electronically stabilized, leaving no surface states in the mid-gap region...
January 19, 2018: Scientific Reports
Hiroshi Saito, Tatsuya Ishikawa, Jun Tanabe, Shinya Kobayashi, Junta Moroi
This pilot study aimed to investigate the utility of near-infrared spectroscopy/indocyanine green (NIRS/ICG) for examining patients with occlusive cerebrovascular disease. Twenty-nine patients with chronic-stage atherosclerotic occlusive cerebrovascular disease were included. The patients were monitored using NIRS at the bedside. Using ICG time-intensity curves, the affected-to-unaffected side ratios were calculated for several parameters, including the maximum ICG concentration (ΔICGmax), time to peak (TTP), rise time (RT), and blood flow index (BFI = ΔICGmax/RT), and were compared to the affected-to-unaffected side ratios of the regional cerebral blood flow (rCBF) and regional oxygen extraction fraction (rOEF) obtained using positron emission tomography with 15O-labeled gas...
January 19, 2018: Scientific Reports
C C Cao, Y G Wang, L Zhu, Y Meng, X B Zhai, Y D Dai, J K Chen, F M Pan
In this work, an attempt has been made to reveal critical factors dominating the crystallization and soft magnetic properties of Fe81Si x B10P8-xCu1 (x = 0, 2, 4, 6 and 8) alloys. Both melt spun and annealed alloys are characterized by differential scanning calorimetry, X-ray diffractometry, Mössbauer spectroscopy, transmission electron microscopy, positron annihilation lifetime spectroscopy and magnetometry. The changes in magnetic interaction between Fe atoms and chemical homogeneity can well explain the variation of magnetic properties of Fe81Si x B10P8-xCu1 amorphous alloys...
January 19, 2018: Scientific Reports
Atharva A Poundarik, Adele Boskey, Caren Gundberg, Deepak Vashishth
Tough natural nanocomposites like bone, nacre and sea sponges contain within their hierarchy, a mineral (phosphate, silicate or carbonate) phase that interacts with an organic phase. In bone, the role of mineral ultrastructure (organization, morphology, composition) is crucial to the mechanical and biological properties of the tissue. Better understanding of mineral interaction with the organic matrix, in particular non-collagenous proteins, osteocalcin (OC) and osteopontin (OPN), can lead to better design of biomimetic materials...
January 19, 2018: Scientific Reports
Majid Nasiriboroumand, Majid Montazer, Hossein Barani
The potential application of any nanoparticles, including silver nanoparticles (AgNPs), strongly depends on their stability against aggregation. In the current study, an aqueous extract of pomegranate peel was used as a stabilizer during synthesis of AgNPs. Nanoparticles have been prepared by the chemical reduction method from an aqueous solution of silver nitrate in the presence of sodium borohydride as a reducing agent. The AgNPs were characterized by dynamic light scattering (DLS), zeta-potential measurements, UV-Vis spectroscopy and transmission electron microscopy (TEM)...
January 10, 2018: Journal of Photochemistry and Photobiology. B, Biology
Xiaorong Zhang, Aysu Yarman, Júlia Erdossy, Sagie Katz, Ingo Zebger, Katharina J Jetzschmann, Zeynep Altintas, Ulla Wollenberger, Róbert E Gyurcsányi, Frieder W Scheller
Molecularly imprinted polymer (MIP) nanofilms for transferrin (Trf) have been synthesized on gold surfaces by electro-polymerizing the functional monomer scopoletin in the presence of the protein target or around pre-adsorbed Trf. As determined by atomic force microscopy (AFM) the film thickness was comparable with the molecular dimension of the target. The target (re)binding properties of the electro-synthesized MIP films was evaluated by cyclic voltammetry (CV) and square wave voltammetry (SWV) through the target-binding induced permeability changes of the MIP nanofilms to the ferricyanide redox marker, as well as by surface plasmon resonance (SPR) and surface enhanced infrared absorption spectroscopy (SEIRAS) of the immobilized protein molecules...
January 9, 2018: Biosensors & Bioelectronics
Sidra Islam, Abdul Rouf Mir, Mir Yasir Arfat, Farzana Khan, Masihuz Zaman, Asif Ali, Moinuddin
Structural alterations in proteins under oxidative stress have been widely implicated in the immuno-pathology of various disorders. This study has evaluated the extent of damage in the conformational characteristics of IgG by hydroxyl radical (OH) and studied its implications in the immuno-pathology of rheumatoid arthritis (RA). Using various biophysical and biochemical techniques, changes in aromatic microenvironment of the IgG and the protein aggregation became evident after treatment with OH. The SDS-PAGE study confirmed the protein aggregation while far ultraviolet circular dichroism spectroscopy (Far-UV CD) and fourier transform infrared spectroscopy (FTIR) inferred towards the alterations in secondary structure of IgG under OH stress...
January 10, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Tang Tang, Fangdi Wei, Xu Wang, Yujie Ma, Yueyue Song, Yunsu Ma, Quan Song, Guanhong Xu, Yao Cen, Qin Hu
A novel molecularly imprinted stir bar (MI-SB) for sorptive extraction of semicarbazide (SEM) was prepared in present paper. The coating of the stir bar was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, dynamic adsorption and static adsorption tests. The saturated adsorption of MI-SB was about 4 times over that of non-imprinted stir bar (NI-SB). The selectivity of MI-SB for SEM was much better than NI-SB. A method to determine SEM was established by coupling MI-SB sorptive extraction with HPLC-UV...
January 4, 2018: Journal of Chromatography. B, Analytical Technologies in the Biomedical and Life Sciences
Darryl P Arfsten, Erick Roman Perez, Neal C Goebel
Calculating measurement uncertainty is a helpful exercise for identifying components or steps in a forensic analytical procedure that contribute to measurement variance. In this study, we used a bottom up approach to identify components in our procedures that contribute to measurement variance in our Department of Defense (DoD) Drug Demand Reduction Program (DDRP) Gas Chromatography Mass Spectroscopy (GCMS) analytical procedures for benzoylecgonine (BZE) and the THC metabolite, 11-nor-Δ9-THC-9-carboxylic acid (THCA) at 125% the DDRP concentration threshold (cutoff)...
January 17, 2018: Journal of Analytical Toxicology
Artem Grebenko, Vyacheslav Dremov, Petr Barzilovich, Anton Bubis, Konstantin Sidoruk, Tatiyana Voeikova, Zarina Gagkaeva, Timur Chernov, Evgeny Korostylev, Boris Gorshunov, Konstantin Motovilov
For decades respiratory chain and photosystems were the main firing field of the studies devoted to mechanisms of electron transfer in proteins. The concept of conjugated lateral electron and transverse proton transport during cellular respiration and photosynthesis, which was formulated in the beginning of 1960-s, has been confirmed by thousands of experiments. However, charge transfer in recently discovered bacterial nanofilaments produced by various electrogenic bacteria is regarded currently outside of electron and proton conjugation concept...
2018: PloS One
Min Yang, Haofei Hong, Shaozhong Liu, Xinrui Zhao, Zhimeng Wu
Chitosan macro-particles prepared by the neutralization method were applied to Sortase A (SrtA) immobilization using glutaraldehyde as a crosslinking agent. The particles were characterized by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Response surface methodology (RSM) was employed to optimize the immobilization process. An average specific activity of 3142 U (mg protein)-1 was obtained under optimized immobilization conditions (chitosan concentration 3%, SrtA concentration 0...
January 19, 2018: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Othman Montacir, Houda Montacir, Murat Eravci, Andreas Springer, Stephan Hinderlich, Fereidoun Mahboudi, Amirhossein Saadati, Maria Kristina Parr
Eptacog alfa (NovoSeven®) is a vitamin K-dependent recombinant Factor VIIa produced by genetic engineering from baby hamster kidney (BHK) cells as a single peptide chain of 406 residues. After activation, it consists of a light chain (LC) of 152 amino and a heavy chain (HC) of 254 amino acids. Recombinant FVIIa undergoes many post-translational modifications (PTMs). The first ten glutamic acids of the N-terminal moiety are γ-carboxylated, Asn145 and Asn322 are N-glycosylated, and Ser52 and Ser60 are O-glycosylated...
January 19, 2018: Bioengineering
Shih-Jen Lin, Jyh-Ming Ting, Kuo-Chin Hsu, Yaw-Shyan Fu
A novel composite photocatalyst based on Cu₂ZnSnS₄ (CZTS) powders was synthesized and investigated for use as a photocatalyst. CZTS powders were first made using a conventional hydrothermal method and were then used to grow silver nanoparticles hybridized onto the CZTS under various conditions through a microwave-assisted hydrothermal process. After the obtained samples were subsequently mixed with 1T-2H MoS₂, the three synthesized component samples were characterized using X-ray diffractometry (XRD), scanning electron microscopy, transmission electron microscopy (FE-SEM, FE-TEM), UV-visible spectroscopy (UV-Vis), Brunauer-Emmet-Teller (BET), photoluminescence spectroscopy (PL), and X-ray photoelectron spectroscopy (XPS)...
January 19, 2018: Materials
Liqing Li, Xiancheng Ma, Ruofei Chen, Chunhao Wang, Mingming Lu
Nitrogen-doped porous carbon (ZC) is prepared by modification with ammonia for increasing the specific surface area and surface polarity after carbonization of zeolite imidazole framework-8 (ZIF-8). The structure and properties of these ZCs were characterized by Transmission electron microscopy, X-ray diffraction, N₂ sorption, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. Through static adsorption tests of these carbons, the sample obtained at 600 °C was selected as an excellent adsorbent, which exhibited an excellent acetone capacity of 417...
January 19, 2018: Materials
Knarik Tamanyan, Lisa M Walter, Aidan Weichard, Margot J Davey, Gillian M Nixon, Sarah N Biggs, Rosemary Sc Horne
RATIONALE: Childhood sleep disordered breathing ranges in severity from primary snoring to obstructive sleep apnea and is associated with behavioral and neurocognitive deficits. It remains unknown why children with primary snoring, who do not experience peripheral oxygen desaturation or sleep fragmentation, experience similar daytime deficits as those with obstructive sleep apnea or why effects are age dependent. OBJECTIVE: To examine cerebral tissue oxygenation and oxygen extraction as an explanation for daytime deficits in children with primary snoring...
January 19, 2018: American Journal of Respiratory and Critical Care Medicine
Peter Kaufmann, Timm F Gloger, Delia Kaufmann, Michael Johanning, Christof Wunderlich
A promising scheme for building scalable quantum simulators and computers is the synthesis of a scalable system using interconnected subsystems. A prerequisite for this approach is the ability to faithfully transfer quantum information between subsystems. With trapped atomic ions, this can be realized by transporting ions with quantum information encoded into their internal states. Here, we measure with high precision the fidelity of quantum information encoded into hyperfine states of a ^{171}Yb^{+} ion during ion transport in a microstructured Paul trap...
January 5, 2018: Physical Review Letters
Corey J White, Amy L Speelman, Claudia Kupper, Serhiy Demeshko, Franc Meyer, James P Shanahan, E Ercan Alp, Michael Hu, Jiyong Zhao, Nicolai Lehnert
Flavodiiron nitric oxide reductases (FNORs) are a subclass of flavodiiron proteins (FDPs) capable of preferential binding and subsequent reduction of NO to N2O. FNORs are found in certain pathogenic bacteria, equipping them with resistance to nitrosative stress, generated as a part of the immune defense in humans, and allowing them to proliferate. Here, we report the spectroscopic characterization and detailed reactivity studies of the diiron dinitrosyl model complex [Fe2(BPMP)(OPr)(NO)2](OTf)2 for the FNOR active site that is capable of reducing NO to N2O [Zheng et al...
January 19, 2018: Journal of the American Chemical Society
Sankar Raman Vaikuntam, Klaus Werner Stöckelhuber, Eshwaran Subramani Bhagavatheswaran, Sven Wiessner, Ulrich Scheler, Kay Saalwaechter, Petr Formanek, Gert Heinrich, Amit Das
A sol-gel transformation of liquid silica precursor to solid silica particles was carried out in a one pot synthesis way where a solution of styrene butadiene elastomer (S-SBR) was present. The composites, thus produced, offered remarkable improvements of mechanical and dynamic mechanical performances as compared with precipitated silica. The morphological analysis reveals that the alkoxy-based silica particles resemble a raspberry structure when the synthesis of the silica was carried out in presence of polymer molecules and represent a much more open silica-network structure...
January 19, 2018: Journal of Physical Chemistry. B
Qinke Wu, Joohyun Lee, Sangwoo Park, Hwi Je Woo, Sungjoo Lee, Young Jae Song
In this study, we demonstrate a new method to selectively etch the point defects or the boundaries of as-grown hexagonal boron nitride (hBN) films and flakes in situ on copper substrates using hydrogen and argon gases. The initial quality of the chemical vapor deposition-grown hBN films and flakes was confirmed by UV-vis absorption spectroscopy, atomic force microscopy, and transmission electron microscopy. Different gas flow ratios of Ar/H2 were then employed to etch the same quality of samples and it was found that etching with hydrogen starts from the point defects and grows epitaxially, which helps in confirming crystalline orientations...
January 19, 2018: Nanotechnology
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