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排序方式: 共有84条查询结果,搜索用时 218 毫秒
1.
Alexandra Fidalgo Tessy M. Lopez Laura M. Ilharco 《Journal of Sol-Gel Science and Technology》2009,49(3):320-328
Wet sol–gel silica matrices produced under different hydrolysis conditions were used as delivery devices to the active principle
of an antiepileptic drug (phenytoin sodium), encapsulated during the condensation stage. Post-incorporation into dry silica
powder was an alternative loading procedure. It was proven by infrared spectroscopy that neither the silica network nor the
drug loose integrity by encapsulation. The kinetics of in vitro drug release was studied at 37 °C, to water and to artificial
cerebrospinal fluid (ACSF). Emphasis has been given to the release to ACSF under dynamic conditions (with fluid renovation,
emulating what occurs in the brain). Different delivery regimes were identified and correlated with the loading method and
the matrix structure. Matrices with lower total porosity and smaller average pore size proved to be better for a long term
release. Renovation of ACSF is relevant to assure a constant concentration of phenytoin in the vicinity of the device. 相似文献
2.
Robson Miranda da Gama Tatiana Santana Balogh Simone França Tânia Cristina Sá Dias Valcinir Bedin André Rolim Baby Jivaldo do Rosário Matos Maria Valéria Robles Velasco 《Journal of Thermal Analysis and Calorimetry》2011,106(2):399-405
This research aimed the effect on Caucasian hair tresses treated with oxidative hair dye, either incorporated or not with
conditioners agents, analyzed by Differential Scanning Calorimetry (DSC) and Thermogravimetric analysis (TG). The formulations
of hair dyes were emulsions oil-in-water with light blond color containing or not the conditioners agents: silanetriol and
panthenol; PEG-12 dimethicone; hydrolyzed silk, hydrolyzed milk protein, and lactose. Each dye (1.5 g) was applied in the
hair tress (2.0 g/20.0 cm of length of Caucasian light-brown), previously treated, more 1.5 g of hydrogen peroxide 20 vol
during 40 min. Evaluation of mass loss of the different hair sample demonstrates that these chemical hair treatments impair
the hair fibers, reduced their moisture content with respect to the untreated hair. The incorporation of conditioners agents
(silanetriol and panthenol; PEG-12 dimethicone; hydrolyzed silk, hydrolyzed milk protein, and lactose) in oxidative hair dyes
types did not decrease the damage caused on the tresses by the coloring process quantified by TG/DTG. However, the DSC curves
demonstrated those conditioners agents (silanetriol and panthenol; PEG-12 dimethicone) dislocated the beginning of the third
event in 20 °C and they inhibited the presence of the fourth event, having characterized thermal protection to the hair. 相似文献
3.
4.
Sony Baby T. Balasubramanian R. J. Pardikar 《Theoretical and Applied Fracture Mechanics》2003,40(2):145-151
Embedded vertical cracks are very often encountered in structural components necessitating reliable procedure for determining their size. Specialized ultrasonic techniques are required for estimation of through thickness height of these cracks [Mater. Eval. (1970) 28; J. NDI 26 (1977) 320; NND (1975) 146]. The conventional pulse-echo technique has serious limitations for quantitative estimation of vertical cracks because it is subject to variations due to reflectivity, coupling factors etc. The present study aims to improve the accuracy of embedded crack height measurement based on transit time rather than the reflected amplitude [NDT Int. (1982) 315; J. JSNDT 27 (1978) 118]. A unique method has been developed for generating known sizes of fatigue cracks ranging from 2.5 to 18 mm in height and 15 mm in length. These cracks were generated in rectangular steel specimens and subsequently embedded at predetermined locations using welding. These welded specimens containing the embedded vertical cracks were examined using ultrasonic techniques based on transit time like (a) flaw tip echo method and (b) mode conversion method. Using both the techniques excellent agreement was obtained between the estimated crack height and actual crack height with an accuracy of ±1 mm. 相似文献
5.
Bosco Christin Maria Arputham Ashwin Ramesh Kumar Chitumalla Arulanandu Herculin Arun Baby Joonkyung Jang Paulpandian Muthu Mareeswaran 《Journal of inclusion phenomena and macrocyclic chemistry》2018,90(1-2):51-60
The supramolecular host–guest investigation of Coumarin 460 (C460), a salient coumarin family dye molecule is studied with a noteworthy host molecule, p-sulfonatocalix[4]arene (p-SC4). The investigation is carried out by both experimental and theoretical approach. The binding affinity of C460 with p-SC4 is experimentally studied using absorption, emission, excited state lifetime and Cyclic Voltammetry methods. The binding constant is around 103 M??1, which shows potent binding. The binding stoichiometry is 1:1. The binding orientations and binding energies are studied using computational simulations. The mode of binding is also established using NMR spectral techniques. 相似文献
6.
Manuel Soriano-García Rubén Alfredo Toscano Tessy López Antonio Campero-Celis 《Journal of chemical crystallography》1987,17(6):719-728
The title compound is C35H32NBFe3, monoclinic,P21/n,a=14.204 (4),b=11.582 (4),c=17.547 (6) Å,=101.46 (2)°. The structure was solved by the heavy-atom method and refined by least-squares techniques to anR factor of 0.037 for 3148 observed reflections. The X-ray study confirms that in the solid state the structure of the title compound is similar to that inferred from chemical and spectroscopic evidence. The B atom is coordinated by three ferrocenyl groups and a pyridine ring in a distorted tetrahedral array. The molecule has a nearly three-fold axis normal to the plane defined by the ferrocenyl groups. The B-N distance of 1.656 (5) Å is larger than that obtained for other compounds studied. Bond lengths and angles for the whole structure are all in accord with similar compounds. The pyridine and cyclopentadienyl rings are planar. The H atoms of the cyclopentadienyl rings are displaced significantly toward their corresponding Fe atom. The molecules in the crystal are packed at normal van der Waals distances. No unusually short intermolecular contacts are noted. 相似文献
7.
Ponnusamy Shanmugam Baby Viswambharan Kodirajan Selvakumar Suchithra Madhavan 《Tetrahedron letters》2008,49(16):2611-2615
The [3+2] cycloaddition reaction of azomethine ylides with isomerised Morita-Baylis-Hillman adducts, both dipoles and dipolarophiles are derived from isatin, afforded highly functionalised 3,3′-dispiro pyrrolidine- and 3,3′-dispiropyrrolizidine bisoxindoles in high yields. 相似文献
8.
KM Varier AM Vinodkumar NVSV Prasad PV Madhusudhana Rao DL Sastry Lagy T Baby MC Radhakrishna NG Puttaswamy JJ Das P Sugathan N Madhavan AK Sinha DO Kataria 《Pramana》1999,53(3):529-533
Large enhancements have been observed in the sub-barrier fusion cross sections for Ti+Ni systems in our previous studies.
Coupled channel calculations incorporating couplings to 2+ and 3− states failed to explain these enhancements completely. A possibilty of transfer channels contributing to the residual enhancements
had been suggested. In order to investigate the role of relevant transfer channels, measurements of one- and two-nucleon transfer
were carried out for 46,48Ti+61Ni systems. The present paper gives the results of these studies. 相似文献
9.
Lilian Mussi Andr Rolim Baby Flavio Bueno Camargo Junior Giovana Padovani Bianca da Silva Sufi Wagner Vidal Magalhes 《Molecules (Basel, Switzerland)》2021,26(21)
In addition to dermatological complications, acne can affect the quality of life of individuals in numerous ways, such as employment, social habits and body dissatisfaction. According to our expertise, caprylic acid and propanediol would not have a direct action on Cutibacterium acnes. Despite this, we investigated the existence of a synergistic effect among xylitol, caprylic acid and propanediol as a mixture of compounds representing a single topical active ingredient that could benefit the treatment against acne. In vitro and in vivo assays were performed to challenge and to prove the efficacy of propanediol, xylitol and caprylic acid (PXCA) against acne. PXCA had its MIC challenged against C. acnes (formerly Propionibacterium acnes) and Staphylococcus aureus, resulting in concentrations of 0.125% and 0.25%, respectively, and it also developed antimicrobial activity against C. acnes (time-kill test). PXCA was able to reduce the 5-alpha reductase expression in 24% (p < 0.01) in comparison with the testosterone group. By the end of 28 days of treatment, the compound reduced the skin oiliness, porphyrin amount and the quantity of inflammatory lesions in participants. According to the dermatologist evaluation, PXCA improved the skin’s general appearance, acne presence and size. 相似文献
10.
Ponnusamy Shanmugam Vadivel Vaithiyanathan Baby Viswambharan Suchithra Madhavan 《Tetrahedron letters》2007,48(52):9190-9194
The reaction of the Baylis–Hillman adduct 2 of ferrocenealdehyde with various oxygen and carbon nucleophiles in the presence of montmorillonite K10 clay catalyst furnished highly functionalised trisubstituted alkene derivatives of ferrocenealdehyde in excellent yield. Synthetic use of one of products 7 has been demonstrated with the synthesis of a 1,3-diyne ether derivative of ferrocene 16 via an Eglinton coupling reaction. 相似文献