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991.
Seung Young Lee Eunjung Moon Sun Yeou Kim Kang Ro Lee 《Bioorganic & medicinal chemistry letters》2013,23(7):2140-2144
Five new quinic acid derivatives (1–5), together with 10 known quinic acid derivatives (6–15), were isolated from the MeOH extract of Pimpinella brachycarpa (Umbelliferae). Their structures were established on the basis of spectroscopic analyses including extensive 2D NMR studies (COSY, HMQC and HMBC). Isolated compounds 1–15 were evaluated for their inhibitory activities on nitric oxide (NO) production in an activated murine microglial cell line. Compounds 2, 3, 8 and 11 significantly inhibited NO production without high cell toxicity in lipopolysaccharide (LPS)-activated BV-2 cells, a microglia cell line (IC50 = 4.66, 12.52, 9.04 and 12.11 μM, respectively). 相似文献
992.
Zhigang Ren Guangying Cui Haifeng Lu Xinhua Chen Jianwen Jiang Hui Liu Yong He Songming Ding Zhenhua Hu Weilin Wang Shusen Zheng 《PloS one》2013,8(10)
Background
Ischemia-reperfusion (I/R) injury is associated with intestinal microbial dysbiosis. The “gut-liver axis” closely links gut function and liver function in health and disease. Ischemic preconditioning (IPC) has been proven to reduce I/R injury in the surgery. This study aims to explore the effect of IPC on intestinal microbiota and to analyze characteristics of microbial structure shift following liver transplantation (LT).Methods
The LT animal models of liver and gut IPC were established. Hepatic graft function was assessed by histology and serum ALT/AST. Intestinal barrier function was evaluated by mucosal ultrastructure, serum endotoxin, bacterial translocation, fecal sIgA content and serum TNF-α. Intestinal bacterial populations were determined by quantitative PCR. Microbial composition was characterized by DGGE and specific bacterial species were determined by sequence analysis.Principal Findings
Liver IPC improved hepatic graft function expressed as ameliorated graft structure and reduced ALT/AST levels. After administration of liver IPC, intestinal mucosal ultrastructure improved, serum endotoxin and bacterial translocation mildly decreased, fecal sIgA content increased, and serum TNF-α decreased. Moreover, liver IPC promoted microbial restorations mainly through restoring Bifidobacterium spp., Clostridium clusters XI and Clostridium cluster XIVab on bacterial genus level. DGGE profiles indicated that liver IPC increased microbial diversity and species richness, and cluster analysis demonstrated that microbial structures were similar and clustered together between the NC group and Liver-IPC group. Furthermore, the phylogenetic tree of band sequences showed key bacteria corresponding to 10 key band classes of microbial structure shift induced by liver IPC, most of which were assigned to Bacteroidetes phylum.Conclusion
Liver IPC cannot only improve hepatic graft function and intestinal barrier function, but also promote restorations of intestinal microbiota following LT, which may further benefit hepatic graft by positive feedback of the “gut-liver axis”. 相似文献993.
Dong K. Kim 《In vitro cellular & developmental biology. Animal》1997,33(4):289-293
Summary Doubling time has been widely used to represent the growth pattern of cells. A traditional method for finding the doubling
time is to apply gray-scaled cells, where the logarithmic transformed scale is used. As an alternative statistical method,
the log-linear model was recently proposed, for which actual cell numbers are used instead of the transformed gray-scaled
cells. In this paper, I extend the log-linear model and propose the extended log-linear model. This model is designed for
extra-Poisson variation, where the log-linear model produces the less appropriate estimate of the doubling time. Moreover,
I compare statistical properties of the gray-scaled method, the log-linear model, and the extended log-linear model. For this
purpose, I perform a Monte Carlo simulation study with three data-generating models: the additive error model, the multiplicative
error model, and the overdispersed Poisson model. From the simulation study, I found that the gray-scaled method highly depends
on the normality assumption of the gray-scaled cells; hence, this method is appropriate when the error model is multiplicative
with the log-normally distributed errors. However, it is less efficient for other types of error distributions, especially
when the error model is additive or the errors follow the Poisson distribution. The estimated standard error for the doubling
time is not accurate in this case. The log-linear model was found to be efficient when the errors follow the Poisson distribution
or nearly Poisson distribution. The efficiency of the log-linear model was decreased accordingly as the overdispersion increased,
compared to the extended log-linear model. When the error model is additive or multiplicative with Gamma-distributed errors,
the log-linear model is more efficient than the gray-scaled method. The extended log-linear model performs well overall for
all three data-generating models. The loss of efficiency of the extended log-linear model is observed only when the error
model is multiplicative with log-normally distributed errors, where the gray-scaled method is appropriate. However, the extended
log-linear model is more efficient than the log-linear model in this case. 相似文献
994.
Kim A. DeWeerd William P. Flanagan Michael J. Brennan Jan M. Principe James L. Spivack 《Bioremediation Journal》1998,2(1):29-42
Soil column and serum bottle microcosm experiments were conducted to investigate the potential for in situ anaerobic bioremediation of trichloroethy lene (TCE) and dichloromethane (DCM) at the Pinellas site near Largo, Florida. Soil columns with continuous groundwater recycle were used to evaluate treatment with complex nutrients (casamino acids, methanol, lactate, sulfate); benzoate and sulfate; and methanol. The complex nutrients drove microbial dechlorination of TCE to ethene, whereas the benzoate/sulfate and methanol supported microbial dechlorination of TCE only to cis-1 ,2-dichloroethylene (cDCE). Microbial sulfate depletion in the benzoate/sulfate column allowed further dechlorination of cDCE to vinyl chloride. Serum bottle microcosms were used to investigate TCE dechlorination and DCM biodegradation in Pinellas soil slurries bioaugmented with liquid from the soil columns possessing TCE-dechlorinating activity and DCM biodegradation by indigenous microorganisms. Bioaugmented soil microcosms showed immediate TCE dechlorination in the microcosms with methanol or complex nutrients, but no dechlorination in the benzoate/sulfate microcosm. DCM biodegradation by indigenous microorganisms occurred in soil microcosms amended with either benzoate/sulfate or methanol, but not with complex nutrients. Bioaugmentation stimulated DCM biodegradation in both complex nutrient and methanol-amended microcosms, but appeared to inhibit DCM biodegradation in benzoate/sulfate-amended microcosms. TCE dechlorination occurred before DCM biodegradation in bioaugmented microcosms when both compounds were present. 相似文献
995.
Regional deposition of inhaled particles in human lungs: comparison between men and women 总被引:3,自引:0,他引:3
We measured detailed regional depositionpatterns of inhaled particles in healthy adult male(n = 11; 25 ± 4 yr of age) and female (n = 11; 25 ± 3 yr of age)subjects by means of a serial bolus aerosol delivery technique formonodisperse fine [particle diameter(Dp) = 1 µm] and coarse aerosols(Dp = 3 and 5 µm). The bolus aerosol (40 ml half-width) was delivered to a specificvolumetric depth (Vp) of the lung ranging from 100 to 500 ml with a50-ml increment, and local deposition fraction (LDF) was assessed for each of the 10 local volumetric regions. In all subjects, the deposition distribution pattern was very uneven with respect to Vp,showing characteristic unimodal curves with respect to particle sizeand flow rate. However, the unevenness was more pronounced in women.LDF tended to be greater in all regions of the lung in women than inmen for Dp = 1 µm. For Dp = 3 and 5 µm, LDF showed a marked enhancement in the shallow region of Vp 200 ml in women compared with men(P < 0.05). LDF in women wascomparable to or smaller than those of men in deep lung regions of Vp > 200 ml. Total lung deposition was comparable between men and womenfor fine particles but was consistently greater in women than men forcoarse particles regardless of flow rates used: the difference rangedfrom 9 to 31% and was greater with higher flow rates(P < 0.05). The results indicatethat 1) particledeposition characteristics differ between healthy men and women undercontrolled breathing conditions and2) deposition in women is greaterthan that in men. 相似文献
996.
Yong-Yeon Jo Sang-Wook Kim Sung-Woo Cho Duck-Ho Bae Hyunok Oh 《Cluster computing》2017,20(2):1155-1166
An intuitive way to process the big data efficiently is to reduce the volume of data transferred over the storage interface to a host system. This is the reason that the notion of intelligent SSD (iSSD) was proposed to give processing power to SSD. There is rich literature on iSSD, however, its real implementation has not been provided to the public yet. Most prior work aims to quantify the benefits of iSSD with analytical modeling. In this paper, we first develop on iSSD simulator and present the potential of iSSD in data mining through the iSSD simulator. Our iSSD simulator performs on top of the gem 5 simulator and fully simulates all the processes of data mining algorithms running in iSSD with cycle-level accuracy. Then, we further addresse how to exploit all the computing resources for efficient processing of data mining algorithms. These days, CPU, GPU, and SSD are recently equipped together in most computing environment. If SSD is replaced with iSSD later on, we have a new computing environment where the three computing resources collaborate one another to process big data quite effectively. For this, scheduling is required to decide which computing resource is going to run for which function at which time. In our heterogeneous scheduling, types of computing resources, memory sizes in computing resources, and inter-processor communication times including IO time in SSD are considered. Our scheduling results show that processing in the collaborative environment outperforms that in the traditional one by up to about 10 times. 相似文献
997.
998.
X‐ray crystal structures of the pheromone‐binding domains of two quorum‐hindered transcription factors,YenR of Yersinia enterocolitica and CepR2 of Burkholderia cenocepacia 下载免费PDF全文
999.
Li Hui Wu Xiao Ting Shao Jun Xia Guo Hui Sun Qi Chen Jing Pan Qian Qian Cai Yi Wei Dong Zhong Yi Chen Xiao Mei Yan Min Peng Nanbert Zhong Xing Zhong Wu 《Glycoconjugate journal》2017,34(1):51-59
Sialic acid modification is a kind of post-translational modification. To investigate the regulation effect of sialic acid on neural differentiation, we used CycloManN propanyl perac (CycloManN pro), a metabolic precursor of sialic acid, to treat PC12 cells. We noted that CycloManN pro indeed robustly promoted global sialylation detected by MAL II lectin blot in PC12 cells. Simultaneously, we interestingly found that the neurite outgrowth of PC12 cells was significantly promoted by the CycloManN pro treatment. The profile analysis of sialylated proteins showed that a protein band at 55KD was greatly enhanced especially in PC12L cells after CycloManN pro treatment. After enrichment with lectin MAL II, the proteins in this band were analyzed by mass spectrometry. The results showed that 23 proteins were in the band, but the score of vimentin was the highest among them. To investigate further the role of vimentin in the process of neurite differentiation, vimentin construct was transfected into PC12 cells. We interestingly observed that ectopic expression of vimentin significantly enhanced the neurite outgrowth induced by CycloManN pro. However, after three potential glycosylation sites (Ser-7, Thr-33, Ser-34:) of vimentin were mutated to alanine, overexpression of the mutated vimentin completely lost the enhancement activity for the neural differentiation even in the presence of CycloManN pro. Taken together, our study demonstrated that vimentin was important in the induction of neural differentiation by CycloManN pro. 相似文献
1000.
Felipe Yon Danny Kessler Youngsung Joo Lucas Cortés Llorca Sang‐Gyu Kim Ian T. Baldwin 《植物学报(英文版)》2017,59(3):180-189
Ecological interactions between flowers and pollinators are all about timing.Flower opening/closing and scent emissions are largely synchronized with pollinator activity,and a circadian clock regulates these rhythms.However,whether the circadian clock increases a plant's reproductive success by regulating these floral rhythms remains untested.Flowers of Nicotiana attenuata,a wild tobacco,diurnally and rhythmically open,emit scent and move vertically through a 140° arc to interact with nocturnal hawkmoths.We tethered flowers to evaluate the importance of flower positions for Manduca sexta-mediated pollinations;flower position dramatically influenced pollination.We examined the pollination success of phase-shifted flowers,silenced in circadian clock genes,NaZTL,NaLHY,and NaTOCi,by RNAi.Circadian rhythms in N.attenuata flowers are responsible for altered seed set from outcrossed pollen. 相似文献