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21.
Rostand M. Ngoumfo Jean-Bosco Jouda Ferdinand T. Mouafo Justin Komguem Céline D. Mbazoa Tze Chieh Shiao Mohammed I. Choudhary Hartmut Laatsch Jean Legault André Pichette René Roy 《Bioorganic & medicinal chemistry》2010,18(10):3601-3605
Chemical investigation of the roots and fruits of Zanthoxylum leprieurii Guill. et Perr. led to the isolation of three new alkaloids including two acridone derivatives, 3-hydroxy-1,4-dimethoxy-10-methyl-9-acridone (2) and 3-hydroxy-1,2-dimethoxy-10-methyl-9-acridone (3) named helebelicine A and B, respectively, and one secobenzo[c]phenantridine, 10-O-demethyl-12-O-methylarnottianamide (10), together with thirteen other compounds. The structures of compounds 2, 3 and 10 as well as those of the known compounds were elucidated by using spectroscopic methods and by comparison with reported data. The brine-shrimp (artemia salina) lethality bioassay of the chloroform extract of the fruits showed modest cytotoxicity with LD50 at 13.1 μg/mL. Isolated compounds 1, 4–6 were found to be moderately active against lung carcinoma cells (A549), colorectal adenocarcinoma cells (DLD-1) and normal cells (WS1) with IC50 values ranging from 27 to 77 μM. In contrast to the positive control etoposide used, the cytotoxicity of the most active compound 4 was found to be selective against cancer cells in comparison to normal cells WS1 with IC50 of 51 ± 8 μM and 4.3 ± 0.4 μM, respectively. 相似文献
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The aim of this study was to develop a taste-masked oral disintegrating film (ODF) containing donepezil, with fast disintegration
time and suitable mechanical strength, for the treatment of Alzheimer’s disease. Hydroxypropyl methylcellulose, corn starch,
polyethylene glycol, lactose monohydrate and crosspovidone served as the hydrophilic polymeric bases of the ODF. The uniformity,
in vitro disintegration time, drug release and the folding endurance of the ODF were examined. The in vitro results showed that 80% of donepezil hydrochloride was released within 5 minutes with mean disintegration time of 44 seconds.
The result of the film flexibility test showed that the number of folding time to crack the film was 40 times, an indication
of sufficient mechanical property for patient use. A single-dose, fasting, four-period, eight-treatment, double-blind study
involving 16 healthy adult volunteers was performed to evaluate the in situ disintegration time and palatability of ODF. Five parameters, namely taste, aftertaste, mouthfeel, ease of handling and acceptance
were evaluated. The mean in situ disintegration time of ODF was 49 seconds. ODF containing 7 mg of sucralose were more superior than saccharin and aspartame
in terms of taste, aftertaste, mouthfeel and acceptance. Furthermore, the ODF was stable for at least 6 months when stored
at 40°C and 75% relative humidity. 相似文献
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Marginal regression via generalized estimating equations is widely used in biostatistics to model longitudinal data from subjects
whose outcomes and covariates are observed at several time points. In this paper we consider two issues that have been raised
in the literature concerning the marginal regression approach. The first is that even though the past history may be predictive
of outcome, the marginal approach does not use this history. Although marginal regression has the flexibility of allowing
between-subject variations in the observation times, it may lose substantial prediction power in comparison with the transitional
modeling approach that relates the responses to the covariate and outcome histories. We address this issue by using the concept
of “information sets” for prediction to generalize the “partly conditional mean” approach of Pepe and Couper (J. Am. Stat.
Assoc. 92:991–998, 1997). This modeling approach strikes a balance between the flexibility of the marginal approach and the predictive power of transitional
modeling. Another issue is the problem of excess zeros in the outcomes over what the underlying model for marginal regression
implies. We show how our predictive modeling approach based on information sets can be readily modified to handle the excess
zeros in the longitudinal time series. By synthesizing the marginal, transitional, and mixed effects modeling approaches in
a predictive framework, we also discuss how their respective advantages can be retained while their limitations can be circumvented
for modeling longitudinal data. 相似文献
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Ong Jia Sin Taylor Todd D. Yong Cheng Chung Khoo Boon Yin Sasidharan Sreenivasan Choi Sy Bing Ohno Hiroshi Liong Min Tze 《Probiotics and antimicrobial proteins》2020,12(1):125-137
Probiotics and Antimicrobial Proteins - This study aimed to elucidate the targets and mechanisms of anti-staphylococcal effects from bioactive metabolites produced by lactic acid bacteria. We aimed... 相似文献
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Background
The putative promoter of the holocarboxylase synthetase (HLCS) gene on chromosome 21 is hypermethylated in placental tissues and could be detected as a fetal-specific DNA marker in maternal plasma. Detection of fetal trisomy 21 (T21) has been demonstrated by an epigenetic-genetic chromosome dosage approach where the amount of hypermethylated HLCS in maternal plasma is normalized using a fetal genetic marker on the Y chromosome as a chromosome dosage reference marker. We explore if this method can be applied on both male and female fetuses with the use of a paternally-inherited fetal single nucleotide polymorphism (SNP) allele on a reference chromosome for chromosome dosage normalization.Methodology
We quantified hypermethylated HLCS molecules using methylation-sensitive restriction endonuclease digestion followed by real-time or digital PCR analyses. For chromosome dosage analysis, we compared the amount of digestion-resistant HLCS to that of a SNP allele (rs6636, a C/G SNP) that the fetus has inherited from the father but absent in the pregnant mother.Principal Findings
Using a fetal-specific SNP allele on a reference chromosome, we analyzed 20 euploid and nine T21 placental tissue samples. All samples with the fetal-specific C allele were correctly classified. One sample from each of the euploid and T21 groups were misclassified when the fetal-specific G allele was used as the reference marker. We then analyzed 33 euploid and 14 T21 maternal plasma samples. All but one sample from each of the euploid and T21 groups were correctly classified using the fetal-specific C allele, while correct classification was achieved for all samples using the fetal-specific G allele as the reference marker.Conclusions
As a proof-of-concept study, we have demonstrated that the epigenetic-genetic chromosome dosage approach can be applied to the prenatal diagnosis of trisomy 21 for both male and female fetuses. 相似文献28.
A small library of bivalent α-D-mannopyranosides having rigid linkers was constructed in order to evaluate the effects of inter-saccharide distances upon multivalent binding interactions with plant and bacterial lectins. To this end, iodoaryl and propargyl α-D-mannopyranosides were synthesized and the former treated with TMS-acetylene under palladium chemistry to provide their corresponding ethynylaryl derivatives. A library of 15 dimeric members was then obtained using Lewis acid catalyzed glycosidation, aryl-aryl homocoupling, transition metal catalyzed Sonogashira cross-coupling reactions, and oxidative Glaser homocoupling. 相似文献
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Mei-An Su Yun-Tzu Huang I-Tung Chen Der-Yen Lee Yun-Chieh Hsieh Chun-Yuan Li Tze Hann Ng Suh-Yuen Liang Shu-Yu Lin Shiao-Wei Huang Yi-An Chiang Hon-Tsen Yu Kay-Hooi Khoo Geen-Dong Chang Chu-Fang Lo Han-Ching Wang 《PLoS pathogens》2014,10(6)
In this study, we used a systems biology approach to investigate changes in the proteome and metabolome of shrimp hemocytes infected by the invertebrate virus WSSV (white spot syndrome virus) at the viral genome replication stage (12 hpi) and the late stage (24 hpi). At 12 hpi, but not at 24 hpi, there was significant up-regulation of the markers of several metabolic pathways associated with the vertebrate Warburg effect (or aerobic glycolysis), including glycolysis, the pentose phosphate pathway, nucleotide biosynthesis, glutaminolysis and amino acid biosynthesis. We show that the PI3K-Akt-mTOR pathway was of central importance in triggering this WSSV-induced Warburg effect. Although dsRNA silencing of the mTORC1 activator Rheb had only a relatively minor impact on WSSV replication, in vivo chemical inhibition of Akt, mTORC1 and mTORC2 suppressed the WSSV-induced Warburg effect and reduced both WSSV gene expression and viral genome replication. When the Warburg effect was suppressed by pretreatment with the mTOR inhibitor Torin 1, even the subsequent up-regulation of the TCA cycle was insufficient to satisfy the virus''s requirements for energy and macromolecular precursors. The WSSV-induced Warburg effect therefore appears to be essential for successful viral replication. 相似文献
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Jian Qing Xiao‐Ke Liu Mingjie Li Feng Liu Zhongcheng Yuan Elizaveta Tiukalova Zhibo Yan Martial Duchamp Shi Chen Yuming Wang Sai Bai Jun‐Ming Liu Henry J. Snaith Chun‐Sing Lee Tze Chien Sum Feng Gao 《Liver Transplantation》2018,8(21)
Recently, Ruddlesden–Popper perovskites (RPPs) have attracted increasing interests due to their promising stability. However, the efficiency of solar cells based on RPPs is much lower than that based on 3D perovskites, mainly attributed to their poor charge transport. Herein, a simple yet universal method for controlling the quality of RPP films by a synergistic effect of two additives in the precursor solution is presented. RPP films achieved by this method show (a) high quality with uniform morphology, enhanced crystallinity, and reduced density of sub‐bandgap states, (b) vertically oriented perovskite frameworks that facilitate efficient charge transport, and (c) type‐II band alignment that favors self‐driven charge separation. Consequently, a hysteresis‐free RPP solar cell with a power conversion efficiency exceeding 12%, which is much higher than that of the control device (1.5%), is achieved. The findings will spur new developments in the fabrication of high‐quality, aligned, and graded RPP films essential for realizing efficient and stable perovskite solar cells. 相似文献