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61.
Karla S. Brammer Seunghan Oh Christine J. Frandsen Sungho Jin 《JOM Journal of the Minerals, Metals and Materials Society》2010,62(4):50-55
Nanostructures have pronounced effects on biological processes such as growth of cells and their functionality. Advances in
biomaterial surface structure and design have resulted in improved tissue engineering. Nanotechnology can be utilized for
optimization of titanium implants with a formation of vertically aligned TiO2 nanotube arrays on the implant surface. The anodic oxidation of the titanium implant surface to form a TiO2 nanotube array involves electrochemical processes and self assembly. In this paper, the mechanism of nanotube formation,
nanotube bio-characteristics, and their emerging role in soft and hard tissue engineering as well as in regenerative medicine
will be reviewed, and the beneficial effects of surface nanotubes on cell adhesion, proliferation, and functionality will
be discussed in relation to potential orthopedics applications. 相似文献
62.
Karla Aparecida Guimarães GusmãoLeandro Vinícius Alves Gurgel Tânia Márcia Sacramento MeloLaurent Frédéric Gil 《Dyes and Pigments》2012,92(3):967-974
In a previous work, succinylated sugarcane bagasse (SCB 2) was prepared from sugarcane bagasse (B) using succinic anhydride as modifying agent. In this work the adsorption of cationic dyes onto SCB 2 from aqueous solutions was investigated. Methylene blue, MB, and gentian violet, GV, were selected as adsorbates. The capacity of SCB 2 to adsorb MB and GV from aqueous single dye solutions was evaluated at different contact times, pH, and initial adsorbent concentration. According to the obtained results, the adsorption processes could be described by the pseudo-second-order kinetic model. Adsorption isotherms were well fitted by Langmuir model. Maximum adsorption capacities for MB and GV onto SCB 2 were found to be 478.5 and 1273.2 mg/g, respectively. 相似文献
63.
64.
Molecular Recognition of Two 2,4‐syn‐Functionalized (S)‐Glutamate Analogues by the Kainate Receptor GluK3 Ligand Binding Domain 下载免费PDF全文
Dr. Raminta Venskutonytė Anja P. Larsen Dr. Karla Frydenvang Prof. Michael Gajhede Dr. Emmanuelle Sagot Dr. Zeinab Assaf Dr. Thierry Gefflaut Dr. Darryl S. Pickering Dr. Lennart Bunch Prof. Jette S. Kastrup 《ChemMedChem》2014,9(10):2254-2259
The kainate receptors are the least studied subfamily of ionotropic glutamate receptors. These receptors are thought to have a neuromodulatory role and have been associated with a variety of disorders in the central nervous system. This makes kainate receptors interesting potential drug targets. Today, structures of the ligand binding domain (LBD) of the kainate receptor GluK3 are only known in complex with the endogenous agonist glutamate, the natural product kainate, and two synthetic agonists. Herein we report structures of GluK3 LBD in complex with two 2,4‐syn‐functionalized (S)‐glutamate analogues to investigate their structural potential as chemical scaffolds. Similar binding affinities at GluK3 were determined for the 2‐(methylcarbamoyl)ethyl analogue (Ki=4.0 μM ) and the 2‐(methoxycarbonyl)ethyl analogue (Ki=1.7 μM ), in agreement with the similar positioning of the compounds within the binding pocket. As the binding affinity is similar to that of glutamate, this type of Cγ substituent could be used as a scaffold for introduction of even larger substituents reaching into unexplored binding site regions to achieve subtype selectivity. 相似文献
65.
Alex Lemes Marçal Emerson Henrique de FariaJane Karla de Faria Borges Machado Eduardo José NassarKatia Jorge Ciuffi Paulo Sergio Calefi 《Thin solid films》2012,520(21):6541-6546
Films consisting of Eu3+ β-diketonate complexes were deposited onto glassy substrates by means of the spin- and dip-coating techniques, using different ion/ligand ratios. Absorption spectroscopy in the infrared region revealed the typical stretching bands of the SiOSi and SiOH bonds of the inorganic matrix as well as bands relative to the CO and CH symmetric vibration of β-diketone (dibenzoylmethane). The films displayed UV-visible absorption band at 350 nm, attributed to the organic ligand. Luminescence properties were studied by photoluminescence spectroscopy. Upon ligand excitation, the emission spectra exhibited the characteristic bands of the Eu3+ ion corresponding to the transition from the excited state 5D0 to the ground state 7FJ. Scanning electron microscopy confirmed the formation of a film with average thickness ranging from 80 to 100 nm. The sol-gel process and the deposition techniques resulted in the effective formation of nanofilms, which opens up perspectives for their application in photonics. 相似文献
66.
Fernanda O Silva Melissa S Carvalho Renato Mendon?a Waldemar AA Macedo Karla Balzuweit Peter Reiss Marco A Schiavon 《Nanoscale research letters》2012,7(1):536
We investigate systematically the influence of the nature of thiol-type capping ligands on the optical and structural properties of highly luminescent CdTe quantum dots synthesized in aqueous media, comparing mercaptopropionic acid (MPA), thioglycolic acid (TGA), 1-thioglycerol (TGH), and glutathione (GSH). The growth rate, size distribution, and quantum yield strongly depend on the type of surface ligand used. While TGH binds too strongly to the nanocrystal surface inhibiting growth, the use of GSH results in the fastest growth kinetics. TGA and MPA show intermediate growth kinetics, but MPA yields a much lower initial size distribution than TGA. The obtained fluorescence quantum yields range from 38% to 73%. XPS studies unambiguously put into evidence the formation of a CdS shell on the CdTe core due to the thermal decomposition of the capping ligands. This shell is thicker when GSH is used as ligand, as compared with TGA ligands. 相似文献
67.
Maria Vass Iva Diblikova Eloise Kok Kamil Stastny Karla Frgalova Karel Hruska Milan Franek 《Food Additives & Contaminants》2008,25(8):930-936
An enzyme-linked immunosorbent assay (ELISA) method is described for the semi-quantitative determination of semicarbazide (SEM), the marker residue for the banned nitrofuran drug, nitrofurazone, in chicken eggs. The sample homogenate is subjected to acid hydrolysis and derivatisation with o-nitrobenzaldehyde, followed by ethyl acetate/hexane extraction and detection by ELISA. The ELISA procedure has been validated using 0.3, 1.0 and 3 microg kg(-1) of SEM in fortified samples. Detection capability (CC(ss)) was based on the acceptance of 5% false compliant results for a given concentration level according to Commission Decision 2002/657/EC and was determined to be 0.3 microg kg(-1) with a respective limit of detection of 0.13 microg kg(-1). A validated LC-MS/MS method was used for the analysis of incurred egg samples and the results compared with ELISA. A good correlation between the results obtained from ELISA and LC-MS/MS within the concentration range 0.12-20.3 microg kg(-1) was observed in samples collected from chickens fed with a medicated ration of nitrofurazone (r = 0.992, n = 14). Validated ELISA enabled reliable monitoring of SEM levels in eggs collected from incurred chickens over a 90-day period. 相似文献
68.
Ajita Patil Linchung Li Liming Dai Michael Casavant Karla Strong 《Journal of the Society for Information Display》2005,13(9):709-718
Abstract— The optoelectronic, mechanical, and thermal properties of carbon nanotubes have made them very attractive for a wide range of potential applications. However, many applications require the growth of aligned/micropatterned carbon nanotubes with or without a modified nanotube surface. We have developed several simple pyrolytic methods for large‐scale production of aligned carbon‐nanotube arrays perpendicular to the substrate surface. We have also used photolithographic and soft‐lithographic techniques to pattern our aligned carbon nanotubes with submicron resolution. These aligned carbon‐nanotube arrays can be transferred onto various substrates of particular interest (e.g., on conducting substrates as electron emitters for flat‐panel displays) in either a patterned or non‐patterned fashion. The well‐aligned structure further allows us to prepare aligned coaxial nanowires of carbon nanotubes sheathed with polymers and to modify the surface of individual carbon nanotubes by plasma treatment. These aligned/micropatterned carbon nanotubes with and without surface modification possess desirable properties for electron emission applications. 相似文献
69.
In the autoxidation of 1-piperidinocyclohex-1-ene ( 1 ), 1-piperidinobut-1-ene ( 2 ), 3-piperidinopent-2-ene ( 3 ), and 1-piperidino-2-methyl-prop-1-ene( 4 ) only products of an oxidative attack at the CC-double bond are formed. Both α-aminoketones, the products of the rearrangement of primarily formed epoxides, and products of the oxidative session of the CC double bond are obtained. As a side reaction some hydrolysis of the starting enamines takes place. This hydrolysis proves that some water must be formed during the enamine oxidation. 相似文献
70.
Schroeder C Werner K Otten H Krätzig S Schwalbe H Essen LO 《Chembiochem : a European journal of chemical biology》2008,9(15):2463-2473
BLUF-domain-comprising photoreceptors sense blue light by utilizing FAD as a chromophore. The ycgF gene product of Escherichia coli is composed of a N-terminal BLUF domain and a C-terminal EAL domain, with the latter postulated to catalyze c-di-GMP hydrolysis. The linkage between these two domains involves a predominantly helical segment. Its role on the function of the YcgF photoreceptor domain was examined by characterizing BLUF domains with and without this segment and reconstituting them with either FAD, FMN or riboflavin. The stability of the light-adapted state of the YcgF BLUF domain depends on the presence of this joining, helical segment and the adenosine diphosphate moiety of FAD. In contrast to other BLUF domains, two-dimensional (1)H,(15)N and one-dimensional (1)H NMR spectra of isotope-labeled YcgF-(1-137) revealed large conformational changes during reversion from the light- to the dark-adapted state. Based on these results the function of the joining helix in YcgF during signal transfer and the role of the BLUF domain in regulating c-di-GMP levels is discussed. 相似文献