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https://www.readbyqxmd.com/read/28532096/preparation-of-nanocrystalline-forsterite-by-combustion-of-different-fuels-and-their-comparative-in-vitro-bioactivity-dissolution-behaviour-and-antibacterial-studies
#1
Rajan Choudhary, Prasanth Manohar, Jana Vecstaudza, Maria Josefa Yáñez-Gascón, Horacio Pérez Sánchez, Ramesh Nachimuthu, Janis Locs, Sasikumar Swamiappan
This study presents different fuels (Glycine and Urea) that can be used to synthesize nanocrystalline forsterite by the sol-gel combustion method. The weight change of precursor during thermal treatment was studied by thermo-gravimetric analysis (TGA). Pure forsterite was characterized by heating microscopy, Fourier transform infrared spectroscopy, X-ray Diffraction, Brunauer-Emmett-Teller, Scanning Electron Microscopy, and Energy dispersive X-ray spectroscopy. The HAP (hydroxyapatite) deposition ability, degradation and dissolution behaviour of forsterite was examined in simulated body fluid (SBF)...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532065/in-vitro-performance-of-ag-incorporated-hydroxyapatite-and-its-adhesive-porous-coatings-deposited-by-electrostatic-spraying
#2
Ozkan Gokcekaya, Thomas J Webster, Kyosuke Ueda, Takayuki Narushima, Celaletdin Ergun
Bacterial infection of implanted materials is a significant complication that might require additional surgical operations for implant retrieval. As an antibacterial biomaterial, Ag-containing hydroxyapatite (HA) may be a solution to reduce the incidences of implant associated infections. In this study, pure, 0.2mol% and 0.3mol% Ag incorporated HA powders were synthesized via a precipitation method. Colloidal precursor dispersions prepared from these powders were used to deposit porous coatings onto titanium and stainless steel substrates via electrostatic spraying...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532059/selective-determination-of-ag-using-salecan-derived-nitrogen-doped-carbon-dots-as-a-fluorescent-probe
#3
Junjian Li, Gancheng Zuo, Xiaoliang Qi, Wei Wei, Xiaohao Pan, Ting Su, Jianfa Zhang, Wei Dong
We report that nitrogen doped carbon dots (N-CDs) represent a viable fluorescent probe for the determination of Ag(+). The N-CDs can be fairly easily prepared by a hydrothermal treatment method using Salecan and dicyandiamide as the precursors, display excitation/emission maxima of 350/438nm. The N-CDs have an average diameter of about 3.8nm. The N-CDs exhibited blue fluorescence (quantum yield of 13.2%) and could response to Ag(+) selectively and sensitively. Other ions nearly had no interference. The probe has excellent selectivity, high sensitivity, and a linear response range that extends from 0 to 40μM...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532025/new-tetrahedral-zinc-halide-schiff-base-complexes-synthesis-crystal-structure-theoretical-3d-hirshfeld-surface-analyses-antimicrobial-and-thermal-studies
#4
L Taghizadeh, M Montazerozohori, A Masoudiasl, S Joohari, J M White
A new bidentate Schiff base ligand named as N,N'-bis((E)-3-phenylallylidene)butane-1,4-diamine (L) and three its zinc halide complexes were synthesized and characterized by FT-IR, (1)H NMR, (13)C NMR and UV-Vis spectroscopy. The crystal structure of zinc bromide and iodide complexes were characterized using single crystal X-ray diffraction. The two structures are isomorphous, crystallizing in the monoclinic crystal system with space group C2/c with closely similar unit cell dimensions. In these complexes, the Zn(II) ion is in the center of a distorted tetrahedral environment completed by two iminic nitrogen atoms of Schiff base ligand and two halide anions...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28532019/characterization-of-bladder-acellular-matrix-hydrogel-with-inherent-bioactive-factors
#5
Dan Jiang, Jianwen Huang, Huili Shao, Xuechao Hu, Lujie Song, Yaopeng Zhang
Bladder acellular matrix (BAM) hydrogel may have great potential in tissue engineering due to outstanding biocompatibility and the presence of inherent bioactive factors in BAM. In this study, we prepared the BAM hydrogel by the method of enzymatic solubilization with pepsin and characterize the microrheological properties of the BAM precursor solution. The structures of the BAM hydrogel were characterized by scanning electron microscope (SEM), Fourier-transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC)...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28531887/expression-and-characterization-of-membrane-type-4-matrix-metalloproteinase-mt4-mmp-and-its-different-forms-in-melanoma
#6
Bettina Hieronimus, Julian Pfohl, Christian Busch, Lutz Graeve
BACKGROUND/AIMS: Membrane-type matrix metalloproteinases (MT-MMPs) are expressed on the cell surface and hydrolyze extracellular matrix components and signaling molecules by which they influence cancer cell migration and metastasis. Two of the six known MT-MMPs are anchored to the plasma membrane via a GPI anchor, one of which is MT4-MMP. Only little is known about MT4-MMP expression, synthesis, regulation and degradation. METHODS: We analyzed several human cancer cell lines as well as tissue homogenates using Western blotting and quantitative PCR for the expression of MT4-MMP...
May 25, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28531559/per-and-polyfluoroalkyl-substances-in-firefighting-foam-concentrates-and-water-samples-collected-near-sites-impacted-by-the-use-of-these-foams
#7
Xavier Dauchy, Virginie Boiteux, Cristina Bach, Christophe Rosin, Jean-François Munoz
To extinguish large-scale fuel fires, fluorosurfactant based foams (FSBFs) were developed in the 1960s and have been used ever since. In this study, 154 per- and polyfluoroalkyl substances (PFASs) including 122 emerging PFASs used as surfactants in FSBFs were sought in nine different foam concentrates. Field investigations were also carried out in the vicinity of four sites where FSBFs are or were intensively used (two airports, a training center for firefighters and an oil storage depot after a large explosion)...
May 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28531557/characterization-of-dissolved-organic-carbon-leached-from-a-woodchip-bioreactor
#8
Ibrahim Abusallout, Guanghui Hua
Woodchip bioreactors are increasingly being applied to remove nitrate from agricultural subsurface drainage. However, dissolved organic carbon (DOC) released from woodchips may negatively affect the aquatic ecosystems and drinking water supplies. The objective of this study was to evaluate the leaching characteristics, disinfection byproduct (DBP) formation potentials, and treatability of DOC derived from a laboratory woodchip bioreactor. Initial flush of woodchips resulted in the release of high organic content from woodchips...
May 13, 2017: Chemosphere
https://www.readbyqxmd.com/read/28531287/bacterial-rna-polymerase-caps-rna-with-various-cofactors-and-cell-wall-precursors
#9
Christina Julius, Yulia Yuzenkova
Bacterial RNA polymerase is able to initiate transcription with adenosine-containing cofactor NAD+, which was proposed to result in a portion of cellular RNAs being 'capped' at the 5΄ end with NAD+, reminiscent of eukaryotic cap. Here we show that, apart from NAD+, another adenosine-containing cofactor FAD and highly abundant uridine-containing cell wall precursors, UDP-Glucose and UDP-N-acetylglucosamine are efficiently used to initiate transcription in vitro. We show that the affinity to NAD+ and UDP-containing factors during initiation is much lower than their cellular concentrations, and that initiation with them stimulates promoter escape...
May 22, 2017: Nucleic Acids Research
https://www.readbyqxmd.com/read/28531166/-epiafzelechin-protects-against-ovariectomy-induced-bone-loss-in-adult-mice-and-modulate-osteoblastic-and-osteoclastic-functions-in-vitro
#10
Ka-Chun Wong, Sisi Cao, Xiaoli Dong, Man-Chun Law, Tak-Hang Chan, Man-Sau Wong
The present study was designed to characterize the bone protective effects of (-)-epiafzelechin (EAF), a flavan-3-ol, in mature ovariectomized mice model and its ability to stimulate osteoblastic activity and inhibit osteoclastic activity. Mature C57BL/6 mice (three to four months old) were either ovariectomised (OVX) or sham-operated and subjected to treatment (vehicle, 17β-oestradiol (E2, 200 μg/kg/day) or EAF (500 μg/kg/day) orally for six weeks. EAF and E2 significantly reduced urinary calcium (Ca) excretion, serum osteocalcin (OCN), and urinary deoxy-pyridinoline (DPD); increased bone mineral density (BMD); and improved micro-architectural properties in OVX mice...
May 22, 2017: Nutrients
https://www.readbyqxmd.com/read/28531160/synthesis-and-characterization-of-constrained-geometry-oxygen-and-sulphur-functionalized-cyclopentadienylchromium-complexes-and-their-use-in-catalysis-for-olefin-polymerization
#11
Ruiguo Zhao, Jun Ma, Hao Zhang, Jiling Huang
A series of constrained geometry O-functionalized cyclopentadienylchromium complexes (1-6) and a S-functionalized cyclopentadienylchromium complex (7) were first synthesized, characterized, and tested as catalyst precursors for the olefin polymerization. In the presence of MAO, the complexes exhibited high catalytic activity for the polymerization of ethylene. It is shown that ligand variations can have a substantial effect on catalyst activity and stability. The effect of Al/Cr ratio on catalytic activity was also studied...
May 22, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
https://www.readbyqxmd.com/read/28531096/the-lys-asp-tyr-triad-within-the-mite-allergen-der-p-1-propeptide-is-a-critical-structural-element-for-the-ph-dependent-initiation-of-the-protease-maturation
#12
Andy Chevigné, Vincenzo Campizi, Martyna Szpakowska, David Bourry, Marie-Eve Dumez, José C Martins, André Matagne, Moreno Galleni, Alain Jacquet
The major house dust mite allergen, Der p 1, is a papain-like cysteine protease expressed as an inactive precursor, proDer p 1, carrying an N-terminal propeptide with a unique structure. The maturation of the zymogen into an enzymatically-active form of Der p 1 is a multistep autocatalytic process initiated under acidic conditions through conformational changes of the propeptide, leading to the loss of its inhibitory ability and its subsequent gradual cleavage. The aims of this study were to characterize the residues present in the Der p 1 propeptide involved in the initiation of the zymogen maturation process, but also to assess the impact of acidic pH on the propeptide structure, the activity of Der p 1 and the fate of the propeptide...
May 20, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28530818/metal-foam-based-ultrafast-electronucleation-of-hydrates-at-low-voltages
#13
Arjang Shahriari, Palash Vadiraj Acharya, Katherine Carpenter, Vaibhav Bahadur
The induction time for the nucleation of hydrates can be significantly reduced by electronucleation, which consists of applying an electrical potential across the hydrate precursor solution. This study reveals that open-cell aluminum foam electrodes can reduce the electronucleation induction time by 150X, when compared to non-foam electrodes. Experiments with tetrahydrofuran hydrates show that aluminum foam electrodes trigger near-instantaneous nucleation (in only 10's of seconds) at low voltages. Furthermore, this study suggests that two distinct interfacial mechanisms influence electronucleation, namely electrolytic bubble generation, and the formation of metal ion complex-based coordination compounds...
May 22, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28530808/%C3%AE-halo-amides-as-competent-latent-enolates-direct-cata-lytic-asymmetric-mannich-type-reaction
#14
Bo Sun, Pandur Venkatesan Balaji, Naoya Kumagai, Masakatsu Shibasaki
α-Halogenated carbonyl compounds are susceptible to dehalogenation and thus largely neglected as enolate precursors in catalytic enantioselective C-C bond forming reactions. By merging the increased stability of the α-C-halogen bond of amides and the direct enolization methodology of the designed amide, we explored a direct catalytic asymmetric Mannich-type reaction of α-halo 7-azaindoline amides with N-carbamoyl imines. All α-halo sub-stituents, α-F, -Cl, -Br, -I amides, were tolerated to provide the Mannich-adducts in a highly stereoselective manner without undesirable dehalogenation...
May 22, 2017: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/28530759/a-dual-emission-probe-to-detect-moisture-and-water-in-organic-solvents-based-on-green-tb-3-post-coordinated-metal-organic-frameworks-with-red-carbon-dots
#15
Jing-Xing Wu, Bing Yan
Using p-phenylenediamine as a precursor, p-carbon dots (p-CDs) with strong red-light emission were encapsulated into a metal-organic framework (MOF) followed by introduction of green light-emitting Tb(3+) to form a two-color light-emitting hybrid (Tb(3+)@p-CDs/MOF). The as-prepared fluorescent-functionalized MOF not only maintained the excellent optical properties of p-CDs and Tb(3+) to give strong emission, but also had good chemical and physical properties. The chosen p-CDs were aggregated readily in water, which led to only very weak photoluminescence, whereas the opposite effect was noted in the organic solvents ethanol, dimethylformamide and cyclopropane...
May 22, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/28530719/the-tailored-synthesis-of-nanosized-sapo-34-via-time-controlled-silicon-release-enabled-by-an-organosilane-precursor
#16
Jingwei Zheng, Jiajia Ding, Dongliang Jin, Guanghua Ye, Kake Zhu, Xinggui Zhou, Weimin Yang, Weikang Yuan
Phenyltrimethoxysilane as a Si source can significantly slow down the crystallization process for SAPO-34 synthesis, leading to the formation of agglomerated nanocrystals (<100 nm). The obtained nanosized SAPO-34 shows enhanced catalytic stability in methanol-to-olefin conversion under industrially relevant conditions.
May 22, 2017: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/28530714/cd8%C3%AE-%C3%AE-intraepithelial-lymphocytes-arise-from-two-main-thymic-precursors
#17
Roland Ruscher, Rebecca L Kummer, You Jeong Lee, Stephen C Jameson, Kristin A Hogquist
TCRαβ(+)CD4(-)CD8α(+)CD8β(-) intestinal intraepithelial lymphocytes (CD8αα IELs) are an abundant population of thymus-derived T cells that protect the gut barrier surface. We sought to better define the thymic IEL precursor (IELp) through analysis of its maturation, localization and emigration. We defined two precursor populations among TCRβ(+)CD4(-)CD8(-) thymocytes by dependence on the kinase TAK1 and rigorous lineage-exclusion criteria. Those IELp populations included a nascent PD-1(+) population and a T-bet(+) population that accumulated with age...
May 22, 2017: Nature Immunology
https://www.readbyqxmd.com/read/28530604/biogenic-amine-concentrations-and-evolution-in-chilled-canadian-pork-for-the-japanese-market
#18
Tania M Ngapo, Lise Vachon
The aim of this study was to evaluate concentrations and evolution of biogenic amines in Canadian pork destined for the Japanese market. At 48h post-mortem, export quality loins were aged at -1.7°C for 13, 28, 43 or 58d (chilled) or 4.0°C for 5d (fresh). Increasing concentrations of putrescine, spermine and spermidine were observed with chilled ageing period and were greater in chilled export (43d at -1.7°C) than domestic market (5d at 4.0°C) pork equivalents. Cadaverine was detected, but was not influenced by ageing conditions, and tyramine was only detected in some samples after 43days at -1...
October 15, 2017: Food Chemistry
https://www.readbyqxmd.com/read/28530545/synthesis-and-biological-evaluation-of-curcumin-nitroxide-based-molecular-hybrids-as-antioxidant-and-anti-proliferative-agents
#19
Balázs Bognár, Muthulakshmi Kuppusamy, Esha Madan, Tamás Kálai, Mária Balog, József Jekő, Periannan Kuppusamy, Kálmán Hideg
BACKGROUND: Natural products and their derivatives are widely used to treat cancer and other diseases associated with ROS- and RNS-induced damages. METHODS: A series of paramagnetic modified curcumin analogues and 3,5-diarylidene-piperidones (DAP) have been designed, synthesized, and characterized on their anti-proliferative and antioxidant activity. RESULTS: Biological characterization of the new compounds supported the earlier results that incorporation of a nitroxide moiety or its precursor into curcumin or diarylidenylpiperidone (DAP) scaffolds resulted in anti-proliferative effect toward cancerous cell-lines in case of aryl hydroxy and/or methoxy substituent containing derivatives suggesting their potential for targeted therapeutic applications...
May 22, 2017: Medicinal Chemistry
https://www.readbyqxmd.com/read/28530397/synthesis-of-1-4-oxazepane-2-5-diones-via-cyclization-of-rotationally-restricted-amino-acid-precursors-and-structural-reassignment-of-serratin
#20
Ewout Ruysbergh, Kristof Van Hecke, Christian Victor Stevens, Norbert De Kimpe, Sven Mangelinckx
Several natural products containing a 1,4-oxazepane-2,5-dione-core are known. One example is serratin, isolated from Serratia marcescens. Due to the presence of a carboxylic amide, which has a preference for a trans-conformation, and the presence of a labile lactone in this core, many synthetic methodologies commonly used for the cyclization towards medium-sized heterocycles cannot be applied. As N-acyl amino acids without a third substituent at nitrogen failed to undergo ring-closure, several N-protecting groups were evaluated...
May 22, 2017: Journal of Organic Chemistry
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