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排序方式: 共有1024条查询结果,搜索用时 15 毫秒
41.
42.
Dayane Mayumi Miyasaki Alexandra Cristina Senegaglia Srgio Adriane Bezerra de Moura Amanda Leitolis Luiz Guilherme Achcar Capriglione Letícia Fracaro Lidiane Maria Boldrini Leite Paulo Henrique Utumi Felipe Yukio Ishikawa Fragoso Fernando Meyer Alejandro Correa Paulo Roberto Slud Brofman 《International journal of molecular sciences》2022,23(5)
Chronic kidney disease (CKD) is characterized by structural abnormalities and the progressive loss of kidney function. Extracellular vesicles (EVs) from human umbilical cord tissue (hUCT)-derived mesenchymal stem cells (MSCs) and expanded human umbilical cord blood (hUCB)-derived CD133+ cells (eCD133+) maintain the characteristics of the parent cells, providing a new form of cell-free treatment. We evaluated the effects of EVs from hUCT-derived MSCs and hUCB-derived CD133+ cells on rats with CDK induced by an adenine-enriched diet. EVs were isolated by ultracentrifugation and characterized by nanoparticle tracking analysis (NTA) and electron microscopy. The animals were randomized and divided into the MSC-EV group, eEPC-EV group and control group. Infusions occurred on the seventh and 14th days after CKD induction. Evaluations of kidney function were carried out by biochemical and histological analyses. Intense labeling of the α-SMA protein was observed when comparing the control with MSC-EVs. In both groups treated with EVs, a significant increase in serum albumin was observed, and the increase in cystatin C was inhibited. The results indicated improvements in renal function in CKD, demonstrating the therapeutic potential of EVs derived from MSCs and eCD133+ cells and suggesting the possibility that in the future, more than one type of EV will be used concurrently. 相似文献
43.
Yukio Kakuda Firouz Jahaniaval Massimo F. Marcone Lourdes Montevirgen Quintin Montevirgen Joselyn Umali 《Journal of the American Oil Chemists' Society》2000,77(9):991-997
The fatty acid and triacylglycerol composition of pili nut (Canarium ovatum) oil and fractions were analyzed by gas chromatography and reversed-phase high-performance liquid chromatography, respectively.
The oil obtained by solvent extraction was low in polyunsaturated fatty acids and high in saturates. The polyunsaturated fatty
acid (18∶2 and 18∶3) contents were less than 11%, whereas palmitic (16∶0) and stearic acid (18∶0) were 33.3 and 10.9%, respectively.
The saturated fatty acid level of the low-melting fraction oil was reduced from 44.4 to 35.5% and the total unsaturated fatty
acid levels were increased from 55.6 to 65% by fractional crystallization. Triacylglycerol analysis showed that the high-melting
fraction (HM) from pili nut oil consisted of POP, POS, and SOS+SSO (P=palmitic acid, O=oleic acid, and S=stearic acid) in
the proportion of 48.6, 38.8, and 8.7%, respectively. The physicochemical properties of the HM fraction were studied using
differential scanning calorimetry and pulsed nuclear magnetic resonance. The results showed that the melting range and solid
fat content of the HM fraction were very similar to those isolated from cocoa butter and olive oil. The content of POP played
an important role in determining the melting range of the HM fraction. It is suggested that this HM fraction may have applications
as a cocoa butter substitute in confectionery products. 相似文献
44.
Crossing experiments between two closely related moths, Ostrinia scapulalis and O. zealis, were conducted to gain insight into the genetic basis of the divergence of female sex pheromones. The sex pheromone of O. scapulalis comprises (E)-11- and (Z)-11-tetradecenyl acetates (E11 and Z11), and distinct genetic variation is found in the blend of components. This variation is largely controlled by a single autosomal locus with two alleles, AE(sca) and AZ(sca). E-type (AE(sca)AE(sca)) females produce a pheromone with amean E11:Z11 ratio of 99:1, whereas Z-type (AZ(sca)AZ(sca)) and I-type (AE(sca)AZ(sca)) females produce a pheromone with a mean of 3:97 and 64:36, respectively. O. zealis is distinctive in that it has a third pheromone component, (Z)-9-tetradecenyl acetate (Z9), in addition to E11 and Z11, and the typical blend ratio is 60:35:5 (Z9:E11:Z11). Our study revealed that Z9 production in O. zealis is mainly regulated by an autosomal recessive gene phr(zea), which is suggested to be involved in the chain-shortening of a pheromone precursor fatty acid, and linked to AE(zea), a gene corresponding to AE(sca) in O. scapulalis. A few mutations in a gene involved in pheromone production could explain the dramatic shift between a two-component pheromone communication system in O. scapulalis and a three-component system in O. zealis. 相似文献
45.
Oishi M Nagatsugi F Sasaki S Nagasaki Y Kataoka K 《Chembiochem : a European journal of chemical biology》2005,6(4):718-725
A novel pH-sensitive and targetable antisense ODN delivery system based on multimolecular assembly into polyion complex (PIC) micelles of poly(L-lysine) (PLL) and a lactosylated poly(ethylene glycol)-antisense ODN conjugate (Lac-PEG-ODN) containing an acid-labile linkage (beta-propionate) between the PEG and ODN segments has been developed. The PIC micelles thus prepared had clustered lactose moieties on their peripheries and achieved a significant antisense effect against luciferase gene expression in HuH-7 cells (hepatoma cells), far more efficiently than that produced by the nonmicelle systems (ODN and Lac-PEG-ODN) alone, as well as by the lactose-free PIC micelle. In line with this pronounced antisense effect, the lactosylated PIC micelles showed better uptake than the lactose-free PIC micelles into HuH-7 cells; this suggested the involvement of an asialoglycoprotein (ASGP) receptor-mediated endocytosis process. Furthermore, a significant decrease in the antisense effect (27 % inhibition) was observed for a lactosylated PIC micelle without an acid-labile linkage (thiomaleimide linkage); this suggested the release of the active (free) antisense ODN molecules into the cellular interior in response to the pH decrease in the endosomal compartment is a key process in the antisense effect. Use of branched poly(ethylenimine) (B-PEI) instead of the PLL for PIC micellization led to a substantial decrease in the antisense effect, probably due to the buffer effect of the B-PEI in the endosome compartment, preventing the cleavage of the acid-labile linkage in the conjugate. The approach reported here is expected to be useful for the construction of smart intracellular delivery systems for antisense ODNs with therapeutic value. 相似文献
46.
Kinetic Study of the Prooxidant Effect of α-Tocopherol. Hydrogen Abstraction from Lipids by α-Tocopheroxyl Radical 总被引:1,自引:0,他引:1
Aya Ouchi Masaharu Ishikura Kensuke Konishi Shin-ichi Nagaoka Kazuo Mukai 《Lipids》2009,44(10):935-943
A kinetic study of the prooxidant effect of α-tocopherol was performed. The rates of allylic hydrogen abstraction from various
unsaturated fatty acid esters (ethyl stearate 1, ethyl oleate 2, ethyl linoleate 3, ethyl linolenate 4, and ethyl arachidonate 5) by α-tocopheroxyl radical in toluene were determined, using a double-mixing stopped-flow spectrophotometer. The second-order
rate constants (k
p) obtained are <1 × 10−2 M−1 s−1 for 1, 1.90 × 10−2 M−1 s−1 for 2, 8.33 × 10−2 M−1 s−1 for 3, 1.92 × 10−1 M−1 s−1 for 4, and 2.43 × 10−1 M−1 s−1 for 5 at 25.0 °C. Fatty acid esters 3, 4, and 5 contain two, four, and six –CH2– hydrogen atoms activated by two π-electron systems (–C=C–CH2–C=C–). On the other hand, fatty acid ester 2 has four –CH2– hydrogen atoms activated by a single π-electron system (–CH2–C=C–CH2–). Thus, the rate constants, k
abstr/H, given on an available hydrogen basis are k
p/4 = 4.75 × 10−3 M−1 s−1 for 2, k
p/2 = 4.16 × 10−2 M−1 s−1 for 3, k
p/4 = 4.79 × 10−2 M−1 s−1 for 4, and k
p/6 = 4.05 × 10−2 M−1 s−1 for 5. The k
abstr/H values obtained for 3, 4, and 5 are similar to each other, and are by about one order of magnitude higher than that for 2. From these results, it is suggested that the prooxidant effect of α-tocopherol in edible oils, fats, and low-density lipoproteins
may be induced by the above hydrogen abstraction reaction. 相似文献
47.
Yoshihiro Sugi Hiroyoshi Maekawa Yukio Hasegawa Akira Ito Ryota Asai Daisuke Yamamoto Kenichi Komura Yoshihiro Kubota Jong-Ho Kim Gon Seo 《Catalysis Today》2008,131(1-4):413-422
Catalytic properties of three-dimensional zeolites, Y (FAU), Beta (BEA), and CIT-1 (CON) zeolites were examined in the alkylation, isopropylation, sec-butylation, and tert-butylation, of biphenyl (BP), and compared to those of H-mordenite (MOR). The selectivities for 4,4′-dialkylbiphenyl (4,4′-DABP) varied with the types of zeolite and of alkylating agent. FAU, BEA, and CON gave only low selectivities for 4,4′-diisopropylbiphenyl (4,4′-DIPB) in the isopropylation, and predominant isomers were bulky and thermodynamically unstable 2,x′-DIPB (2,2′-, 2,3′-, and 2,4′-) at lower temperatures, and bulky and thermodynamically stable 3,4′- and 3,3′-DIPB at higher temperatures: this is quite different from catalytic features over MOR, which gave 4,4′-DIPB with high selectivities at moderate temperatures. These results suggest that FAU, BEA, and CON have no shape-selective nature in the isopropylation, and that the reaction is principally controlled kinetically at lower temperatures, and thermodynamically at higher temperatures. The sec-butylation gave similar results to the isopropylation. Although the selectivities for 4,4′-di-sec-butylbiphenyl (4,4′-DSBB) were higher than those in the isopropylation, predominant isomers were 2,x′-DSBB (2,2′-, 2,3′-, and 2,4′-) at lower temperatures, and 3,4′- and 3,3′-DSBB at higher temperatures. The tert-butylation gave 4,4′-di-tert-butylbiphenyl (4,4′-DTBB) in moderate to high selectivities over all zeolites at moderate temperatures: the selectivity for 4,4′-DTBB was higher than 80% over BEA and CON; however, it still remained at 50% over FAU. FAU channels with super cages are too large for selective formation of 4,4′-DTBB.
From these results, it is concluded that the selectivity for 4,4′-DABP in the alkylation over MOR, FAU, BEA, and CON is determined by the exclusion of bulky isomers at their transition states, and that the exclusion is caused by the steric restriction at the transition states of bulky isomers by the zeolite channels. 相似文献
48.
Yosuke Yamazaki Yohei Abe Yukio Hioki Mitsuyoshi Nakatani Akikazu Kitagawa Kazuhiro Nakata 《Welding International》2016,30(10):745-754
Narrow gap welding with an oscillation laser beam is one of the effective processes for thick plate welding. To put this welding process into practical manufacturing, a groove-sensing system using image processing for narrow gap welding with an oscillation laser beam is used. This developed system uses still images of the weld zone taken by a coaxial CMOS camera. It can recognize the position of the groove wall by analysing the brightness distribution in the still image. It can then control the oscillation width and the laser-irradiated area by calculating the groove width and the groove centre position. Some narrow gap welding experiments were performed to evaluate the performance of the developed system. The results revealed that the developed system is effective for narrow gap welding with an oscillation laser beam. Using this system, the narrow gap groove can be welded even if the groove width has changed during the welding process. 相似文献
49.
Toshiyuki Nagata Kentaro Minami Masatatsu Yamamoto Tsubasa Hiraki Masashi Idogawa Katsumi Fujimoto Shun Kageyama Kazuhiro Tabata Kohichi Kawahara Kazuhiro Ueda Ryuji Ikeda Yukio Kato Masaaki Komatsu Akihide Tanimoto Tatsuhiko Furukawa Masami Sato 《International journal of molecular sciences》2021,22(21)
50.
Kei Nishikawa Yasuhiro Fukunaka Tetsuo Sakka Yukio Ogata J. Robert Selman 《Journal of power sources》2007
The charging (lithiation) and discharging (delithiation) of a Ni–Sn alloy electrode was examined by means of holographic interferometry and laser scanning confocal microscopy (LSCM). The developing concentration profile of Li+ ion during discharging (delithiation) of the Ni–Sn alloy electrode agreed reasonably well with the prediction based on transient diffusion theory, indicating that the cell configuration successfully suppressed natural convection due to the electrochemical reaction. The morphological variation of Ni–Sn alloy electrode during charge/discharge cycle could be observed very clearly by in situ LSCM. It was found that the contraction of active material during the discharge (delithiation) initiates cracks in the Ni–Sn alloy electrode. 相似文献