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961.
962.
Kerr Carolyn L.; Ito Yushi; Manwell Stuart E.E.; Veldhuizen Ruud A.W.; Yao Li-Juan; McCaig Lynda A.; Lewis James F. 《Journal of applied physiology》1998,85(2):676-684
The effectsof both surfactant distribution patterns and ventilation strategiesutilized after surfactant administration were assessed in lung-injuredadult rabbits. Animals received 50 mg/kg surfactant via intratrachealinstillation in volumes of either 4 or 2 ml/kg. A subset ofanimals from each treatment group was euthanized for evaluation of theexogenous surfactant distribution. The remaining animals wererandomized into one of three ventilatory groups: group1 [tidal volume(VT) of 10 ml/kg with 5 cmH2O positive end-expiratorypressure (PEEP)]; group 2 (VT of 5 ml/kg with 5 cmH2O PEEP); orgroup 3 (VT of 5 ml/kg with 9 cmH2O PEEP). Animals wereventilated and monitored for 3 h. Distribution of the surfactant wasmore uniform when it was delivered in the 4 ml/kg volume. When thedistribution of surfactant was less uniform, arterial PO2 values were greater ingroups 2 and3 compared with group1. Oxygenation differences among the differentventilation strategies were less marked in animals with the moreuniform distribution pattern of surfactant (4 ml/kg). In bothsurfactant treatment groups, a high mortality was observed with theventilation strategy used for group 3.We conclude that the distribution of exogenous surfactant affects theresponse to different ventilatory strategies in this model of acutelung injury. 相似文献
963.
Oscillations in the electrostatic energy gap [Velec(t)] for electron transfer from the primary electron donor (P) to the adjacent bacteriochlorophyll (B) in photosynthetic bacterial reaction centers are examined by molecular-dynamics simulations. Autocorrelation functions of Velec in the reactant state (PB) include prominent oscillations with an energy of 17 cm–1. This feature is much weaker if the trajectory is propagated in the product state P+B–. The autocorrelation functions also include oscillations in the regions of 5, 80 and 390 cm–1 in both states, and near 25 and 48 cm–1 in P+B–. The strong 17-cm–1 oscillation could involve motions that modulate the distance between P and B, because a similar oscillation occurs in the direct electrostatic interactions between the electron carriers. 相似文献
964.
Chen‐Che Jeff Huang Humphrey Hung‐Chang Yao 《Molecular reproduction and development》2010,77(6):489-496
Adrenal, testis, and ovary are steroidogenic organs derived from a common primordium that consists of steroidogenic factor 1 (SF1)‐positive precursor cells. SF1 not only defines the steroidogenic lineages in these organs but also controls their differentiation. Recent evidence implicates the Hedgehog (Hh) signaling pathway as a downstream regulator of SF1 in the appearance of steroidogenic cells in these organs. The Hh signaling pathway serves as a common crosstalk component, yet has evolved diverse functions in the expansion and differentiation of the steroidogenic cells in a tissue‐specific manner. The purpose of this review is to compare and contrast the different roles of Hh signaling in these three organs during development. Mol. Reprod. Dev. 77: 489–496, 2010. © 2010 Wiley‐Liss, Inc. 相似文献
965.
966.
Bioinformatics has blossomed in the past decades with the introductionof biological experiments that rapidly produce massive amountsof data (such as the multiple genome projects, the large-scaleanalysis of gene expression, the large-scale analysis of protein–proteininteractions and the large-scale analysis of genome-wide genotype-phenotypeassociations). The resulting bioinformatics tools mainly liein two groups. They may be databases 相似文献
967.
Triterpenoids and Flavonoids from the Leaves of Astragalus membranaceus and Their Inhibitory Effects on Nitric Oxide Production
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Zhi‐Bin Wang Ya‐Dong Zhai Zhen‐Ping Ma Chun‐Juan Yang Rong Pan Jia‐Li Yu Qiu‐Hong Wang Bing‐You Yang Hai‐Xue Kuang 《化学与生物多样性》2015,12(10):1575-1584
Four new cycloartane triterpenes, named huangqiyegenins V and VI and huangqiyenins K and L ( 1 – 4 , resp.), together with nine known triterpenoids, 5 – 13 , and eight flavonoids, 14 – 21 , were isolated from a 70%‐EtOH extract of Astragalus membranaceus leaves. The structures of the new compounds were elucidated by detailed spectroscopic analyses, and the compounds were identified as (9β,11α,16β,20R,24S)‐11,16,25‐trihydroxy‐20,24‐epoxy‐9,19‐cyclolanostane‐3,6‐dione ( 1 ), (9β,16β,24S)‐16,24,25‐trihydroxy‐9,19‐cyclolanostane‐3,6‐dione ( 2 ), (3β,6α,9β,16β,20R,24R)‐16,25‐dihydroxy‐3‐(β‐D ‐xylopyranosyloxy)‐20,24‐epoxy‐9,19‐cyclolanostan‐6‐yl acetate ( 3 ), and (3β,6α,9β,16β,24E)‐26‐(β‐D ‐glucopyranosyloxy)‐16‐hydroxy‐3‐(β‐D ‐xylopyranosyloxy)‐9,19‐cyclolanost‐24‐en‐6‐yl acetate ( 4 ). All isolated compounds were evaluated for their inhibitory activities against LPS‐induced NO production in RAW264.7 macrophage cells. Compounds 1 – 3, 14, 15 , and 18 exhibited strong inhibition on LPS‐induced NO release by macrophages with IC50 values of 14.4–27.1 μM . 相似文献
968.
You‐Min Ying Cui‐Yu Li Yan Chen Jia‐Gui Xiang Ling Fang Jian‐Biao Yao Fa‐Song Wang Ru‐Wei Wang Wei‐Guang Shan Zha‐Jun Zhan 《化学与生物多样性》2015,12(8):1222-1228
Two new triterpenoids, 30‐hydroxylup‐20(29)‐ene 3β‐caffeate ( 1 ) and 24‐nor‐friedelan‐6α,10‐dihydroxy‐1,2‐dioxo‐4,7‐dien‐29‐oic acid ( 2 ), together with eight known compounds 3 – 10 , were isolated from the roots of Celastrus stylosus. The structures of these compounds were elucidated on the basis of spectroscopic analyses. To the best of our knowledge, this represents the first study on the chemical constituents of C. stylosus. The antiproliferative activities of the triterpenoids against six human cancer cell lines (PANC‐1, A549, PC‐3, HepG2, SGC‐7901, and HCCLM3) were evaluated. Compounds 3, 4 , and 10 exhibited comparable activities against PC‐3 and HCCLM3 cell lines as the positive control taxol. 相似文献
969.
Lithium Batteries: Highly Nitridated Graphene–Li2S Cathodes with Stable Modulated Cycles (Adv. Energy Mater. 23/2015)
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970.
Similar or Totally Different: the Adjustment of the Twist Conformation Through Minor Structural Modification,and Dramatically Improved Performance for Dye‐Sensitized Solar Cell
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Zhaofei Chai Mei Wu Manman Fang Sushu Wan Ting Xu Runli Tang Yujun Xie Anyi Mei Hongwei Han Qianqian Li Zhen Li 《Liver Transplantation》2015,5(18)
A novel approach for enhancing the performance of dye‐sensitized solar cells is presented. It is based on the analysis of five sensitizers by utilizing triarylamine as donor, thiophene benzothiadiazole as chromophore and substituted thienyl linked with cyanoacrylic acid as the anchoring group (LI‐80‐LI‐84). Accompanied with the increasing steric hindrance of the substituents on the thienyl isolation group, the conformation of the dyes, in particular the angle between the chromophore and the anchoring group, becomes more and more twisted. Surprisingly, sensitizers with poorer conjugation effects (the higher twisted conformation) achieve better photovoltaic performances, showing a contrary trend to the traditional donor‐(π‐spacer)‐acceptor dyes with a better co‐planarity. On the basis of the preceding fundamental comprehensions, an empirical method is successfully applied to a new phenyl‐based system (LI‐85 and LI‐86) to improve their performances. The systematical investigation indicates that the twisted structures can contribute to the ECB of the TiO2 film, electron lifetime and resistance at the TiO2/dye/electrolyte interface. Thereby, the efficiency of the initial LI‐80‐based cell has been dramatically improved to 2.45 times higher for LI‐86‐based cell, paving a new way for the design of better sensitizers with higher device performances. 相似文献