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Philipp Kickingereder, Ovidiu Cristian Andronesi
Magnetic resonance imaging plays a key role in diagnosis and treatment monitoring of brain tumors. Novel imaging techniques that specifically interrogate aspects of underlying tumor biology and biochemical pathways have great potential in neuro-oncology. This review focuses on the emerging role of 2-hydroxyglutarate-targeted magnetic resonance spectroscopy, as well as radiomics and radiogenomics in establishing diagnosis for isocitrate dehydrogenase mutant gliomas, and for monitoring treatment response and predicting prognosis of this group of brain tumor patients...
February 2018: Seminars in Neurology
Matthieu Picher, Kerstin Bücker, Thomas LaGrange, Florian Banhart
We implement a parametric study with single electron pulses having a 7 ns duration to find the optimal conditions for imaging, diffraction, and electron energy-loss spectroscopy (EELS) in the single-shot approach. Photoelectron pulses are generated by illuminating a flat tantalum cathode with 213 nm nanosecond laser pulses in a 200 kV transmission electron microscope (TEM) with thermionic gun and Wehnelt electrode. For the first time, an EEL spectrometer is used to measure the energy distribution of single nanosecond electron pulses which is crucial for understanding the ideal imaging conditions of the single-shot approach...
March 13, 2018: Ultramicroscopy
Pollyana Trigueiro, Silvia Pedetti, Baptiste Rigaud, Sebastien Balme, Jean-Marc Janot, Ieda M G Dos Santos, Régis Gougeon, Maria G Fonseca, Thomas Georgelin, Maguy Jaber
Wine chemistry inspires and challenges with its complexity and intriguing composition. In this context, the composites based on the use of a model protein, a polyphenol of interest and montmorillonite in a model hydroalcoholic solution have been studied. A set of experimental characterization techniques highlighted the interactions between the organic and the inorganic parts in the composite. The amount of the organic part was determined by ultraviolet-visible (UV-VIS) and thermal analysis. X-ray diffraction (XRD) and transmission electronic microscopy (TEM) informed about the stacking/exfoliation of the layers in the composites...
March 6, 2018: Colloids and Surfaces. B, Biointerfaces
Giorgio Vilardi, Thanasis Mpouras, Dimitris Dermatas, Nicola Verdone, Angeliki Polydera, Luca Di Palma
Carbon Nanotubes (CNTs) and nano Zero-Valent Iron (nZVI) particles, as well as two nanocomposites based on these novel nanomaterials, were employed as nano-adsorbents for the removal of hexavalent chromium, selenium and cobalt, from aqueous solutions. Nanomaterials characterization included the determination of their point of zero charge and particle size distribution. CNTs were further analyzed using scanning electron microscopy, thermogravimetric analysis and Raman spectroscopy to determine their morphology and structural properties...
March 5, 2018: Chemosphere
Bin Hua, John Yang, Fengjing Liu, Guocheng Zhu, Baolin Deng, Jingdong Mao
Characterization of dissolved organic matter/nitrogen (DOM/DON) is critical in water quality assessment and nutrient management in watershed or ecosystem. This study was to investigate the link between DOM/DON and its source using fluorescence excitation-emission matrix (EEM) spectroscopy coupled with parallel factor analysis (PARAFAC). Water samples were collected from various aquatic systems in a watershed located in central Missouri, including rural watershed with various land use and land cover (LULC), landfill, and constructed wetland...
March 6, 2018: Chemosphere
Elif Şenkuytu, Esra Tanrıverdi Eçik
In the study, the new hexa-bodipy functionalized dendrimeric cyclotriphosphazene conjugates (HBCP 1 and 2) have been successfully synthesized and characterized by using general spectroscopic techniques such as1 H,13 C and31 P NMR spectroscopies. The photophysical and metal sensing properties in THF solutions of dendrimeric cyclotriphosphazene conjugates (HBCP 1 and 2) were investigated by UV-Vis and fluorescence spectroscopies in dilute tetrahydrofuran solutions. These dendrimers showed strong absorption bands 501 and 641nm at low concentration with high molar extinction coefficients...
March 9, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
M Kulik, D Kołodyńska, A Bayramov, A Drozdziel, A Olejniczak, J Żuk
The surfaces of (100) GaAs were irradiated with In+ ions. The implanted samples were isobaric annealed at 800°C and then of dielectric function, the surface atomic concentrations of atoms and also the chemical composition of the near surface layers in these implanted semiconductor samples were obtained. The following investigation methods were used: spectroscopic ellipsometry (SE), Rutherford backscattering spectrometry analyses (RBSA) and X-ray photoelectron spectroscopy (XPS) in the study of the above mentioned quantities, respectively...
February 12, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
María S Islas, Juan J Martínez Medina, Oscar E Piro, Gustavo A Echeverría, Evelina G Ferrer, Patricia A M Williams
Coumarins (2H-chromen-2-one) are oxygen-containing heterocyclic compounds that belong to the benzopyranones family. In this work we have synthesized different coordination complexes with coumarin-3-carboxylic acid (HCCA), o-phenanthroline (phen) and zinc(II). In the reported [Zn(CCA)2 (H2 O)2 ] complex, coumarin-3-carboxylate (CCA) is acting as a bidentate ligand while in the two prepared complexes, [Zn(phen)3 ]CCA(NO3 ) (obtained as a single crystal) and [Zn(CCA)2 phen].4H2 O, CCA is acting as a counterion of the complex cation [Zn(phen)3 ]+2 or coordinated to the metal center along with phen, respectively...
March 7, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Priti Sengupta, Aniruddha Ganguly, Adity Bose
The crucial role of chemosensor for the immediate recognition of environment pollutant motivates the researchers to develop variety of sensing protocols. Of various chemosensory protocols, the colour change observed by the naked eye is considered to be a conceivable and on-site way to indicate the presence of an analyte. We herein report a colourimetric and commercially available absorption probe, sinapic acid (SA) that is completely ready to use for "on-site" visual determination of copper ions. The molecule, SA is well-known phenolic acid, often utilized for its antibacterial activity...
March 3, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Jianglou Huang, Jinsong Liu, Kejia Wang, Zhengang Yang, Xiaming Liu
By means of factor analysis approach, a method of molecule classification is built based on the measured terahertz absorption spectra of the molecules. A data matrix can be obtained by sampling the absorption spectra at different frequency points. The data matrix is then decomposed into the product of two matrices: a weight matrix and a characteristic matrix. By using the K-means clustering to deal with the weight matrix, these molecules can be classified. A group of samples (spirobenzopyran, indole, styrene derivatives and inorganic salts) has been prepared, and measured via a terahertz time-domain spectrometer...
March 9, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
A Garbout, M Férid
Considering the features in changing the structure and properties of rare earth titanates pyrochlores, the substituted Dy2 Ti2 O7 may be very attractive for various applications. Effect of Sm and Y substitution on the structural properties of Dy2 Ti2 O7 ceramic was established. These ceramics were prepared by solid-state reaction and characterized by X-ray diffraction and Raman spectroscopy. Both analysis show that YDyTi2 O7 with the pyrochlore structure is obtained after heating at 1400°C, but SmDyTi2 O7 has already formed after sintering at 1200°C...
March 10, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Hamid Reza Rajabi, Fatemeh Karimi, Hossein Kazemdehdashti, Leila Kavoshi
In this research, a sono-assisted chemical precipitation method was developed for a quick and efficient water-based synthesis of zinc sulfide (ZnS) quantum dots (QDs), in room temperature. ZnS QDs as pure and doped with some transition metal ions (such as Cu2+ , Mn2+ , Ag+ ) were prepared in the presence of l-cysteine, as capping agent. In comparison with the previous conventional methods, applying the ultrasonic irradiation provides a significant decrease in the reaction time. In comparison with previous reported conventional chemical QD synthesis methods, the required time for a complete synthesis in the presence of ultrasonic irradiations was significantly reduced to a period as short as 15 min, in a temperature of 40 °C...
February 22, 2018: Journal of Photochemistry and Photobiology. B, Biology
Shelley HuaLei Zhang, Stephan E Maier, Lawrence P Panych
PURPOSE: Magnetic resonance spectroscopic imaging (MRSI), under low-spatial resolution settings, often suffers signal contamination from neighboring voxels due to ringing artifacts. Spatial localization can be improved by constraining the point-spread-function (PSF). Here the effectiveness of the two-dimensional PSF-Choice technique in providing improved spatial localization for MRSI is demonstrated. THEORY AND METHODS: The PSF-Choice technique constrains the PSF to a desired shape by manipulating the weighting of RF excitation pulse throughout phase-encode steps...
March 3, 2018: Journal of Magnetic Resonance
Juan Xiong, Meihua Hu, Xiaoping Li, Hongying Li, Xin Li, Xiang Liu, Guozhong Cao, Weishan Li
A porous graphite (PG) is proposed as anode electrocatalyst of microbial fuel cell (MFC), which is synthesized by thermally decomposing ferrous gluconate followed by leaching iron. The physical characterizations from scanning electron microscopy, Brunauer-Emmett-Teller, X-ray diffraction, Raman spectroscopy, Fourier transform infrared spectroscopy, energy-dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy, indicate that the resulting PG is mesopore-rich and exhibits high graphitization with oxygen-containing functional groups...
March 5, 2018: Biosensors & Bioelectronics
Hendrik Göddeke, M Hadi Timachi, Cedric A Hutter, Laura Galazzo, Markus A Seeger, Mikko Karttunen, Enrica Bordignon, Lars V Schäfer
ATP-binding cassette (ABC) transporters are ATP-driven molecular machines, in which ATP binding and hydrolysis in the nucleotide-binding domains (NBDs) is chemo-mechanically coupled to large-scale, alternating access conformational changes in the transmembrane domains (TMDs), ultimately leading to the translocation of substrates across biological membranes. The precise nature of the structural dynamics behind the large-scale conformational transition as well as the coupling of NBD and TMD motions is still unresolved...
March 16, 2018: Journal of the American Chemical Society
Poovizhi Ponnammal, Parijat Kanaujia, Yin Yani, Wai Kiong Ng, Reginald B H Tan
In order to improve the aqueous solubility and dissolution of Tacrolimus (TAC), amorphous solid dispersions of TAC were prepared by hot melt extrusion with three hydrophilic polymers, Polyvinylpyrrolidone vinyl acetate (PVP VA64), Soluplus® and Hydroxypropyl Cellulose (HPC), at a drug loading of 10% w / w . Molecular modeling was used to determine the miscibility of the drug with the carrier polymers by calculating the Hansen Solubility Parameters. Powder X-ray diffraction and differential scanning calorimetry (DSC) studies of powdered solid dispersions revealed the conversion of crystalline TAC to amorphous form...
March 16, 2018: Pharmaceutics
Enrico Ravagli, Stefano Severi
During hemodialysis (HD), blood is circulated through an extracorporeal tubing system (bloodline) made of medical-grade polymeric material. Sensors of various types that do not come into contact with blood (optical, electromagnetic, etc.) are applied directly across the bloodline for clinical purposes and for therapy customization. Thus, a detailed knowledge of the bloodline's physical properties is useful for the development of next-generation HD sensors. In this work, we performed a novel comparative analysis of the materials used by the manufacturers of the bloodlines...
March 16, 2018: Materials
Radosław Mrówczyński, Artur Jędrzak, Kosma Szutkowski, Bartosz F Grześkowiak, Emerson Coy, Roksana Markiewicz, Teofil Jesionowski, Stefan Jurga
Polydopamine (PDA)-coated magnetic nanoparticles functionalized with mono-6-thio-β-cyclodextrin (SH-βCD) were obtained and characterized by transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR), X-ray photoelectron spectroscopy (XPS), Nuclear and Magnetic Resonance Imaging (NMR and MRI), and doxorubicin (DOXO)-loading experiments. The liver cancer cellular internalization of DOXO-loaded nanoparticles was investigated by confocal imaging microscopy. Synthesized nanomaterials bearing a chemotherapeutic drug and a layer of polydopamine capable of absorbing near-infrared light show high performance in the combined chemo- and photothermal therapy (CT-PTT) of liver cancer due to the synergistic effect of both modalities as demonstrated in vitro...
March 16, 2018: Nanomaterials
Martin Kornecki, Jochen Strube
Productivity improvements of mammalian cell culture in the production of recombinant proteins have been made by optimizing cell lines, media, and process operation. This led to enhanced titers and process robustness without increasing the cost of the upstream processing (USP); however, a downstream bottleneck remains. In terms of process control improvement, the process analytical technology (PAT) initiative, initiated by the American Food and Drug Administration (FDA), aims to measure, analyze, monitor, and ultimately control all important attributes of a bioprocess...
March 16, 2018: Bioengineering
Saverio Affatato, Alessandro Ruggiero, Sami Abdel Jaber, Massimiliano Merola, Pierangiola Bracco
Given the long-term problem of polyethylene wear, medical interest in the new improved cross-linked polyethylene (XLPE), with or without the adding of vitamin E, has risen. The main aim of this study is to gain further insights into the mutual effects of radiation cross-linking and addition of vitamin E on the wear performance of ultra-high-molecular-weight polyethylene (UHMWPE). We tested four different batches of polyethylene (namely, a standard one, a vitamin E-stabilized, and two cross-linked) in a hip joint simulator for five million cycles where bovine calf serum was used as lubricant...
March 16, 2018: Materials
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