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11.
Adriano Polican Ciena Isabela Ugo Luques Fernando José Dias Sonia Regina Yokomizo de Almeida Mamie Mizusaki Iyomasa Ii-sei Watanabe 《Micron (Oxford, England : 1993)》2010,41(8):1011-1014
The myotendon junction (MTJ) is a specialised area into the muscle fibers where the sarcoplasmic membranes connect to the collagen fibers bundles. There are few data about plasticity of the MTJ in aging processes. The aim of this study is to analyse the ultrastructure characteristics of MTJ of medial pterygoid muscle of adult and aged rats. Employing the transmission electron microscopy method, twenty male rats Wistar (Rattus norvegicus) were divided into two groups: A (n = 10) with 12 months of age; B (n = 10) 24 months of age. The animals were anaesthetised with overdose the urethane (3 g/kg, i.p.) and sacrified during the perfusion with modified Karnovsky solution. The specimens were post-fixed in a 1% osmium tetroxide solution, dehydrated in ascending concentration of ethanol and embedded in Spurr resin. The thin sections, of 90 nm thick, were counterstained with uranyl acetate and lead citrate solution, and examined in a Jeol 1010 transmission electron microscope. The fine structure of the MTJ of group A revealed the defined interdigitations and disposed in several levels of deep formations containing the collagen fibers. In the group B, such structures did not observed, detecting the projections irregular in shape, and large of extra matrix with in aspect of remodelling. In conclusion it was possible to identify the plasticity of MTJ in the group B which presented several morphological alterations comparing to the adult animals. These data of group B suggested the occurrence of aging processes in the MTJ in rats. 相似文献
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13.
Nogueira FH Goulart Lde P César Ida C de Campos LM Pianetti GA 《Journal of AOAC International》2011,94(4):1089-1093
A simple HPLC method for determination of mefloquine hydrochloride in tablets was developed and validated. The separation was carried out on an Xterra RP18 (250 x 4.6 mm id, 5 pm particle size) analytical column. The mobile phase was 0.05 M monobasic potassium phosphate buffer (pH 3.5)-methanol (40 + 60, v/v). The flow rate and wavelength were set to 1 mL/min and 283 nm, respectively. The method was specific for mefloquine hydrochloride in the presence of hydrolytic, oxidative, and photolytic degradation products. It was also linear, precise, accurate, and robust, being suitable for routine QC analyses and stability studies. The developed HPLC method was compared to a previously described spectrophotometric method. 相似文献
14.
Lichtwarck-Aschoff A Hasselman F Cox R Pepler D Granic I 《Nonlinear dynamics, psychology, and life sciences》2012,16(3):353-379
This study examined profiles of change in repeated mother-child interactions over the course of a 12 week treatment period for childhood aggression. The aim of this study was to investigate whether it was possible to detect the characteristic profile of change, typical for phase transitions, over the course of treatment, and whether this profile was associated with positive treatment outcomes. Entropy values were computed for six repeated real-time observations of each mother-child dyad, using a novel application of recurrence quantification analysis for categorical time series. Subsequent latent class growth curve analysis on the sequences of entropy values revealed two distinct classes of dyads, with one class showing a clear peak in entropy over the six measurement points. The latent class membership variables showed a significant systematic relationship with observed dyad improvement (as rated by clinicians). The class with the peak in entropy over the sessions consisted largely of treatment improvers. Further analysis revealed that improvers and non-improvers could not be distinguished based on content-specific changes (e.g. more positivity or less negativity during the interaction). The present study revealed a treatment-related destabilization pattern in real-time behaviors that was related to better treatment outcomes, and underlines the value of dynamic nonlinear time-series analysis (especially RQA) in the study of dyadic interactions in clinical contexts. 相似文献
15.
Igor Resendes Barbosa Isabela da Silva Pinheiro Alan Douglas Lopes dos Santos Aurea Echevarria Carla Marins Goulart Guilherme Pereira Guedes Nathally Alves da Costa Beatriz Martinez de Oliveira e Silva Cristiano Jorge Riger Amanda Porto Neves 《Transition Metal Chemistry》2018,43(8):739-751
Four chalcone–thiosemicarbazones (C-TSCs) of the type 2-((E)-3-(4-R-phenyl)-1-phenylallylidene)-N-phenylhydrazinecarbothioamide, where R?=?Cl (HL1), NO2 (HL2), CH3 (HL3) or CN (HL4), were prepared in good yields from the reaction of the respective chalcone with 4-phenyl-3-thiosemicarbazide and HCl in EtOH. Reaction of HL with CuCl2·2H2O or ZnCl2 in the presence of Et3N afforded the complexes [M(L)2], M?=?Cu(II) or Zn(II). X-ray diffraction analysis revealed that the ligands coordinate in their deprotonated form, in a bidentate fashion through the iminic nitrogen and sulfur atoms. Yeast activities of the compounds were tested, where the ligand HL4 was the most damaging derivative, exhibiting cell viability at about 50%. On the other hand, lipid peroxidation assays revealed that the ligand HL1 was able to better induce membrane damage compared to the other compounds. It has been found that coordination with Cu(II) and Zn(II) did not increase the biological activities of the C-TSCs. 相似文献
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Valdés Á Brillet J Grätzel M Gudmundsdóttir H Hansen HA Jónsson H Klüpfel P Kroes GJ Le Formal F Man IC Martins RS Nørskov JK Rossmeisl J Sivula K Vojvodic A Zäch M 《Physical chemistry chemical physics : PCCP》2012,14(1):49-70
An overview of a collaborative experimental and theoretical effort toward efficient hydrogen production via photoelectrochemical splitting of water into di-hydrogen and di-oxygen is presented here. We present state-of-the-art experimental studies using hematite and TiO(2) functionalized with gold nanoparticles as photoanode materials, and theoretical studies on electro and photo-catalysis of water on a range of metal oxide semiconductor materials, including recently developed implementation of self-interaction corrected energy functionals. 相似文献
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Isabela Mendes Baldim Marília Cristina de Oliveira Souza Jo?o Carlos Jacinto da Cunha Souza Eduardo Costa Figueiredo Isarita Martins 《Analytical and bioanalytical chemistry》2012,404(6-7):1959-1966
This study describe an analytical method employing gas chromatography (GC) using flame photometric detection that has been developed for the simultaneous determination of organophosphate pesticides (diazinon, disulfoton, parathion, chlorpyrifos and malathion) in strawberry samples. For this purpose, molecularly imprinted solid-phase extraction was applied as a sample preparation technique. The method was linear in the ranges from 0.10 to 1.00?μg?g?1, for diazinon, disulfoton, parathion and chlorpyrifos, and 0.10 to 2.00?μg?g?1 for malathion with r?>?0.99. The detection limits (LD) ranged from 0.02 to 0.05?μg?g?1. Recovery studies yielded average recoveries in the range of 65.25 to 87.70?%. These results showed the potential of this technique for organophosphate residue monitoring in strawberry samples. 相似文献
18.
Seabra de Lima IM de Andrade LG Ramos de Carvalho R Lailson-Brito J de Freitas Azevedo A 《The Journal of the Acoustical Society of America》2012,131(5):4173-4181
There is no information about the whistles of rough-toothed dolphins in the South Atlantic Ocean. This study characterizes the whistle structure of free-ranging rough-toothed dolphins recorded on the Rio de Janeiro coast, southeastern Brazil, and compares it to that of the same species in other regions. A total of 340 whistles were analyzed. Constant (N = 115; 33.8%) and ascending (N = 99; 29.1%) whistles were the most common contours. The whistles recorded had their fundamental frequencies between 2.24 and 13.94 kHz. Whistles without inflection points were frequently emitted (N = 255; 75%). Some signals presented breaks or steps in their contour (N = 97; 28.5%). Whistle duration was short (347 ± 236 ms and 89.7% of the whistles lasted <600 ms). Seventy-eight whistle contour types were found in the total of whistles analyzed, and 27 (7.9%) of these occurred only once. Most of the whistle types were unique to a particular recording session (N = 43). The signals emitted by the rough-toothed dolphins in southeastern Brazil were characterized by low frequency modulation, short duration, low number of inflection points, and breaks. Differences in the mean values of the whistle parameters were found between this and other studies that recorded Steno bredanensis, but as in other localities, whistles above 14 kHz are rare. 相似文献
19.
César IC Bastos LF Godin AM Coelho Mde M Araujo DP de Fátima  Guidine PA Pianetti GA 《Journal of mass spectrometry : JMS》2011,46(11):1125-1130
A liquid chromatography-electrospray ionization tandem mass spectrometry method was developed and validated for the simultaneous quantitation of nicorandil and its denitrated metabolite, N-(2-hydroxyethyl)-nicotinamide, in rat plasma. After a liquid-liquid extraction step, chromatographic separation was performed on a ShinPack C(18) column with an isocratic mobile phase composed of methanol and 2 mM aqueous ammonium acetate containing 0.03% (v/v) formic acid (33:67 v/v). Procainamide was used as an internal standard (IS). Selected reaction monitoring was performed using the transitions m/z 212 → m/z 135, m/z 166 → m/z 106 and m/z 236 → m/z 163 to quantify nicorandil, its denitrated metabolite and IS, respectively. Calibration curves were constructed over the range of 5-15,000 ng.ml(-1) for both nicorandil and its metabolite. The mean relative standard deviation (RSD%) values for the intra-run precision were 5.4% and 7.3% and for the inter-run precision were 8.5% and 7.3% for nicorandil and its metabolite, respectively. The mean accuracy values were 100% and 95% for nicorandil and its metabolite, respectively. No matrix effect was detected in the samples. The validated method was successfully applied to a pharmacokinetic study after per os administration of nicorandil in rats. 相似文献
20.
Development and application of a high-performance liquid chromatography-mass spectrometry method to determine alendronate in human urine 总被引:1,自引:0,他引:1
Tarcomnicu I Silvestro L Savu SR Gherase A Dulea C 《Journal of chromatography. A》2007,1160(1-2):21-33
Despite the high potential offered by electrospray ionization on highly polar compounds like biphosphonates, few applications have been developed. High-performance liquid chromatography (HPLC) separation methods suitable for such molecules cannot be used in tandem with mass spectrometry (MS) due to high non-volatile salt content; at the same time the sample preparation, in biological fluids, is also a challenging problem. In the past ion-pair chromatography was mainly used in the case of HPLC-MS of biphosphonates, but no application to quantitative pharmacokinetic (PK) studies has been presented. In this study, after preliminary tests with ion-pair chromatography showing a poor sensitivity, a combined derivatization of the amino group and the biphosphonate has been developed and tested in a PK study. Using this analytical approach we were able to fully validate the quantitation of alendronate in the range of 6.667-4860.0 ng/ml in urine (sample volume 2.0 ml); each analytical run was 5.0 min long. The sensitivity achieved permitted a correct evaluation of the alendronate urinary excretion over the full period of urine collection. Sample preparation despite its complexity permitted to process and analyze up to 200 samples in a working day. 相似文献