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1.
Development of biocompatible porous supports is a promising strategy in the field of tissue engineering for the repair and regeneration of bone tissues with severe damage. Graphene oxide aerogels (GOAs) are excellent candidates for the manufacture of these systems due to their porosity, ability to imitate bone structure, and mechanical resistance, and according to their surface chemical reactivity, they can facilitate osseointegration, osteogenesis, osteoinduction and osteoconduction. In this review, synthesis of GOAs from the most primary source is described, and recent studies on the use of these functionalized carbonaceous foams as scaffolding for bone tissue regeneration are presented. 相似文献
2.
da Silva Andre Luis Ferreira Salas Ruben Andres Silva Emilio Carlos Nelli 《Meccanica》2021,56(2):417-437
Meccanica - Fiber reinforced materials are used in assorted engineering application and for this reason, new additive manufacturing technologies have been developed for this type of materials. With... 相似文献
3.
A. Baeza M. Fernández M. Herranz F. Legarda C. Miró A. Salas 《Journal of Radioanalytical and Nuclear Chemistry》2004,260(2):321-326
We studied the effectiveness of potable water treatment processes that consist of the stages of coagulation-flocculation-decantation,
using iron-based coagulants, in eliminating gamma-emitting man-made radioisotopes of cesium, strontium, and americium from
two natural waters with different degrees of mineralization. The resulting decontamination was found to depend on the chemical
behavior of each of the radionuclides considered, on the pH at which the process of coagulation is carried out, and on the
concentration of the other stable cations present.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
4.
We demonstrate, for the first time to our knowledge, that a fast coherent collision between two Kerr spatial solitons can give rise to a significant phase shift for both interacting beams. The maximal collision-induced phase shift ≈π rad takes place when the amplitudes of the solitons are equal (η1=η2) and the length of the interaction zone is comparable with a soliton phase period. Depending on the ratio η2/η1, and the collision angle between the solitons, the magnitude of the phase shift can be varied within a reasonable range, for example from 180° to 40°. The analysis of the effect performed by the finite-difference beam-propagation method has shown that it is insensitive to the initial phase difference between the incident beams (δi), even in the case when η 1≠η2. It has been demonstrated that the phenomenon can be used for all-optical three-soliton logic elements, which are capable of providing more than 3-dB signal amplification and possess bi -independent output characteristics 相似文献
5.
We have developed a coarse-grained multiscale molecular simulation method for soft matter systems that directly incorporates stereochemical information. We divide the material into disjoint groups of atoms or particles that move as separate rigid bodies; we call these groups "rigid blobs," hence the name coarse-grained rigid blob model. The method is enabled by the construction of transferable interblob potentials that approximate the net intermolecular interactions, as obtained from ab initio electronic structure calculations, other all-atom empirical potentials, experimental data, or any combination of the above. We utilize a multipolar expansion to obtain the interblob potential-energy functions. The series, which contains controllable approximations that allow us to estimate the errors, approaches the original intermolecular potential as the number of terms increases. Using a novel numerical algorithm, we can calculate the interblob potentials very efficiently in terms of a few interaction moment tensors. This reduces the labor well beyond what is required in standard molecular-dynamics calculations and allows large-scale simulations for temporal scales commensurate with characteristic times of nano- and mesoscale systems. A detailed derivation of the formulas is presented, followed by illustrative applications to several systems showing that the method can effectively capture realistic microscopic details and can easily extend to large-scale simulations. 相似文献
6.
M. P. Sánchez Sánchez J. M. Salas Peregrin M. A. Romero Molina 《Monatshefte für Chemie / Chemical Monthly》1987,118(8-9):883-891
Some news thiopyrimidine derivatives and complexes [4-amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidine (TANH), its 2-methylthio derivative (MTH), the ammonium salt ofTANH (sTANH) and six new complexes of formulas: Rh(MT)2Cl · 2H2O, Pd(MTH)2Cl2, Pt(MTH)2Cl4, Au(MTH)Cl3 Pd(TANH)2Cl2 and Au(TAN
–)Cl] have been synthesized and characterized by elemental analysis, IR and1H-NMR spectroscopy techniques. The thermal behaviour of all compounds has also been studied.
Rh(III), Pd(II), Pt(IV) und Au(III) Komplexe von 2-Thiopyrimidin Derivaten
Zusammenfassung Es wurden einige neue Thiopyrimidinderivate und deren Komplexe synthetisiert und mittels Elementaranalyse, IR und1H-NMR charakterisiert: 4-Amino-5-nitroso-6-oxo-1,2,3,6-tetrahydro-2-thio-pyrimidin (TANH), dessen 2-Methylthio-Derivat (MTH), das Ammoniumsalz vonTANH (sTANH) und sechs neue Komplexe der Formeln Rh(MT)2Cl · 2H2O, Pd(MTH)2Cl2, Pt(MTH)2Cl4, Au(MTH)Cl3, Pd(TANH)2Cl2 und Au(TAN –)Cl. Das thermische Verhalten der Verbindungen wurde ebenfalls untersucht.相似文献
7.
The aim of the present work is to characterize the pigments present in the kernel of four native maize varieties related to the races Arrocillo, Cónico, Peruano, and Purepecha to determine their possible use as natural dyes. Total anthocyanin content is determined by a conventional spectrophotometric method, and anthocyanin analysis is done by high-performance liquid chromatography. The stability of the pigment at pH is also evaluated. The four maize samples contained anthocyanin in both the pericarp and aleurone layer. Total anthocyanin content among samples ranged from 54 mg/100 g of sample to 115 mg/100 g of sample. Anthocyanin profiles are almost the same among the four samples. Differences are observed only in the relative percentage of each anthocyanin. The anthocyanins identified are cyanidin-3-glucoside, pelargonidin- 3-glucoside, peonidin-3-glucoside, cyanidin-3-(6" malonylglucoside), and cyanidin-3-(3",6"-dimalonylglucoside). Anthocyanin extracts showed similar behavior in solutions with different pH. From pH 1-6 lambdamax values are maintained almost constant; however, above this pH value, a marked increase is observed in the bathochromic shifts, but the bluish color did not continue to change above pH 8. 相似文献
8.
Zhu L Ostash B Rix U Nur-E-Alam M Mayers A Luzhetskyy A Mendez C Salas JA Bechthold A Fedorenko V Rohr J 《The Journal of organic chemistry》2005,70(2):631-638
The angucycline antibiotic family of the landomycins displays potent antitumor activity. To elucidate early post polyketide synthase (PKS) tailoring steps of the landomycin E biosynthetic pathway in Streptomyces globisporus 1912, the mutant S. globisporus M12 was prepared through gene replacement experiment of lndM2. It encodes an enzyme with putative oxygenase and reductase domains, according to sequencing of the gene and its counterpart lanM2 from S. cyanogenus S136 landomycin A biosynthetic gene cluster. The isolation of the novel shunt products 11-hydroxytetrangomycin and 4-hydroxytetrangomycin along with the well-known angucyclines tetrangomycin and tetrangulol from the culture of S. globisporus M12 provides evidence for the involvement of lndM2 in the early biosynthetic pathway of the landomycins, in particular in the formation of the alicyclic 6-hydroxy function of the landomycin aglycon. We therefore propose LndM2 to be responsible for both hydroxylation of the 6-position and its subsequent reduction. These reactions are necessary before the glycosylation reactions can occur. The results are in agreement with the originally published structure of landomycin but do not support the recently suggested revised structure. 相似文献
9.
A theoretical study of the ScCn, ScCn+, and ScCn- (n = 1-8) open-chain clusters has been carried out. Predictions for their electronic energies, rotational constants, dipole moments and vibrational frequencies have been made using the B3LYP method with different basis set including effective core potentials, ECPs. For the ScCn open-chain clusters the lowest-lying states correspond to quartet states for n-odd members, whereas for n-even species the ground state is found to be a doublet. In the cationic and anionic species, the electronic ground state is found to be a singlet for even n and a triplet for odd n. An even-odd parity effect (n-even clusters being more stable than n-odd ones) is observed in neutral and charged clusters. Ionization energies and electron affinities also exhibit a clear parity alternation trend, with n-even clusters having higher values than n-odd ones. 相似文献
10.
Koji Yagi Veronica Garcia Ma. E. Rivas Javier Salas Andres Camargo Takeo Tabata 《Journal of inclusion phenomena and macrocyclic chemistry》1984,2(1-2):179-184
Some crown ethers were found to show significant antifungal activity against some wood-decay fungi, phytopathogenic fungi and eumycetes,Trichophytons for dermatomycosis. Their toxicity was evaluated by the paper disc method as well as by determining the values of ED50, i.e., the concentration which inhibits the mycelium growth by 50%. The fungi examined areTyromyces palustris, Picnoporous coccineus, Coriolous versicolor, Pyricularia filamentosa, Fusarium sp., Trichophyton rubrum, Trichophyton sp., etc. Among the 26 crown ethers tested, 3,5-di-t-butyl-benzo-15-crown-5 showed relatively high activity, the highest ED50 value of which being 8 M or 3 ppm. Other alkylbenzocrown ethers, dicyclohexyl crown ethers and Kryptofix 22DD also showed considerable activity. On the other hand, unsubstituted crown ethers, benzocrown ethers with a polar substituent, Kryptofix 222B and Kryptofix 221 were inactive. 相似文献