期刊文献+
共找到1,913篇文章
< 1 2 96 >
每页显示 20 50 100
Protective effect of long-chain polyunsaturated fatty acids on hepatorenal syndrome in rats
1
作者 João Bruno Beretta Duailibe Cassiana Macagnan Viau +2 位作者 Jenifer Saffi Sabrina Alves Fernandes Marilene Porawski 《World Journal of Nephrology》 2024年第3期49-61,共13页
BACKGROUND Hepatorenal syndrome(HRS)is the most prevalent form of acute kidney injury in cirrhotic patients.It is characterized by reduced renal blood flow and represents the most severe complication in cirrhotic pati... BACKGROUND Hepatorenal syndrome(HRS)is the most prevalent form of acute kidney injury in cirrhotic patients.It is characterized by reduced renal blood flow and represents the most severe complication in cirrhotic patients with advanced disease.Previous research has indicated that antioxidants can delay the onset of a hyperdynamic circulatory state in cirrhosis and improve renal function in HRS patients.Regular omega-3 supplementation has significantly reduced the risk of liver disease.This supplementation could represent an additional therapy for individuals with HRS.AIM To evaluated the antioxidant effect of omega-3 polyunsaturated fatty acid supplementation on the kidneys of cirrhotic rats.METHODS Secondary biliary cirrhosis was induced in rats by biliary duct ligation(BDL)for 28 d.We used 24 male Wistar rats divided into the following groups:I(control);II(treated with omega-3,1 g/kg of body weight);III(BDL treated with omega-3,1 g/kg of body weight);and IV(BDL without treatment).The animals were killed by overdose of anesthetic;the kidneys were dissected,removed,frozen in liquid nitrogen,and stored in a freezer at-80℃for later analysis.We evaluated oxidative stress,nitric oxide(NO)metabolites,DNA damage by the comet assay,cell viability test,and apoptosis in the kidneys.Data were analyzed by one-way analysis of variance,and means were compared using the Tukey test,with P≤0.05.RESULTS Omega-3 significantly decreased the production of reactive oxygen species(P<0.001)and lipoperoxidation in the kidneys of cirrhotic rats treated with omega-3(P<0.001).The activity of the antioxidant enzymes superoxide dismutase and catalase increased in the BDL+omega-3 group compared to the BDL group(P<0.01).NO production,DNA damage,and caspase-9 cleavage decreased significantly in the omega-3-treated BDL group.There was an increase in mitochondrial electrochemical potential(P<0.001)in BDL treated with omega-3 compared to BDL.No changes in the cell survival index in HRS with omega-3 compared to the control group(P>0.05)were observed.CONCLUSION The study demonstrates that omega-3 can protect cellular integrity and function by increasing antioxidant enzymes,inhibiting the formation of free radicals,and reducing apoptosis. 展开更多
关键词 long-chain polyunsaturated fatty acids Antioxidant effect Hepatorenal syndrome Liver cirrhosis Reactive oxygen species APOPTOSIS
下载PDF
Haplotype analysis of long-chain non-coding RNA NONHSAT102891 promoter polymorphisms and depression in Chinese individuals: A case-control association study 被引量:1
2
作者 Yue Li Yi-Xi Wang +5 位作者 Xing-Ming Tang Peng Liang Jing-Jie Chen Feng Jiang Qiang Yang Yun-Dan Liang 《World Journal of Psychiatry》 SCIE 2023年第12期1005-1015,共11页
BACKGROUND Our previous study reported that the single-nucleotide polymorphism(SNP)rs155979 GC in the promoter region of long-chain non-coding RNA(lncRNA)NONHSAT102891 affects depression susceptibility in a Chinese po... BACKGROUND Our previous study reported that the single-nucleotide polymorphism(SNP)rs155979 GC in the promoter region of long-chain non-coding RNA(lncRNA)NONHSAT102891 affects depression susceptibility in a Chinese population.AIM To explored associations of two SNPs and haplotypes in the lncRNA NONHSAT102891 promoter region with depression susceptibility in Chinese population.METHODS This this case-control association study was approved by the Ethics Committee of Chengdu Medical College(approval number:201815).Patient diagnosis was based on DSM-IV criteria.We selected a total of 480 patients with depression and 329 healthy controls with no history of psychopathology,and performed genotyping of two SNPs by extracting peripheral venous blood samples from the subjects.The function of the two lncRNA NONHSAT102891 promoter G/C and A/T haplotypes was detected by dual-luciferase reporter assays of human embryonic kidney 293T transfected cells.RESULTS Stratified analysis of clinical and genotypic characteristics of our cohort showed that the degree of mild depressive episodes associated with the rs6230 TC/CC genotype increased by 1.59 times[TC/CC vs TT:odds ratio(OR)=1.59,95%confidence interval(CI):1.08-2.35,P=0.019].The haploid analysis revealed linkage disequilibrium between rs3792747 and rs6230,and the double SNP CG haplotype was more common in the control group compared to case group,indicating that this haplotype significantly reduced the risk of depression(C/G vs T/A:OR=0.42,95%CI:0.21-0.83,P=0.01).There was no significant difference in the dual-luciferase reporter activity of the G/C and A/T haplotypes compared with the control group(P>0.05),indicating that the double SNP haplotype has no transcrip-tional activity.CONCLUSION The rs3792747 and rs6230 CG haplotypes of the lncRNA NONHSA T102891 promoter may be related to a reduced risk of depression in the Han Chinese population. 展开更多
关键词 long-chain non-coding RNA NONHSAT102891 DEPRESSION SUSCEPTIBILITY Single-nucleotide polymorphisms HAPLOTYPE Transcriptional activity
下载PDF
Long-Chain Gemini Surfactant-Assisted Blade Coating Enables Large-Area Carbon-Based Perovskite Solar Modules with Record Performance
3
作者 Yumin Ren Kai Zhang +5 位作者 Zedong Lin Xiaozhen Wei Man Xu Xianzhen Huang Haining Chen Shihe Yang 《Nano-Micro Letters》 SCIE EI CAS CSCD 2023年第10期463-477,共15页
Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable dep... Carbon-based perovskite solar cells show great potential owing to their low-cost production and superior stability in ambient air.However,scaling up to high-efficiency carbon-based solar modules hinges on reliable deposition of uniform defect-free perovskite films over large areas,which is an unsettled but urgent issue.In this work,a long-chain gemini surfactant is introduced into perovskite precursor ink to enforce self-assembly into a network structure,considerably enhancing the coverage and smoothness of the perovskite films.The long gemini surfactant plays a distinctively synergistic role in perovskite film construction,crystallization kinetics modulation and defect passivation,leading to a certified record power conversion efficiency of 15.46%with Voc of 1.13 V and Jsc of 22.92 mA cm^(-2)for this type of modules.Importantly,all of the functional layers of the module are printed through a simple and high-speed(300 cm min^(-1))blade coating strategy in ambient atmosphere.These results mark a significant step toward the commercialization of all-printable carbon-based perovskite solar modules. 展开更多
关键词 long-chain gemini surfactant Blade-coating Capillary number Carbon-based perovskite photovoltaics All-printable module
下载PDF
Long-chain alkanol-alkyl carboxylic acid-based low-viscosity hydrophobic deep eutectic solvents for one-pot extraction of anthraquinones from Rhei Radix et Rhizoma 被引量:1
4
作者 Anqi Huang Wenwen Deng +3 位作者 Xiao Li Qutong Zheng Xuanxuan Wang Yuxiu Xiao 《Journal of Pharmaceutical Analysis》 SCIE CAS CSCD 2022年第1期87-95,共9页
Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents(HDESs).These HDESs are liquid at room temperature and have low viscosity(<12.26 mPa·s),low pol... Natural long-chain alkanol and alkyl carboxylic acid were used to prepare novel hydrophobic deep eutectic solvents(HDESs).These HDESs are liquid at room temperature and have low viscosity(<12.26 mPa·s),low polarity(lower than that of methanol,ChCl-based deep eutectic solvents and other reported HDESs),and low density(<0.928 g/mL).A simple one-pot method based on a novel HDES-water two-phase extraction system was constructed for the extraction of weak-polarity bioactive components,anthraquinones,from Rhei Radix et Rhizoma.This HDES-based new extraction method does not consume hazardous organic solvents and can obtain a total anthraquinone yield of 21.52 mg/g,which is close to that obtained by the Chinese pharmacopoeia method(21.22 mg/g)and considerably higher than those by other reported HDESs-based extraction methods(14.20-20.09 mg/g,p<0.01).The high extraction yield can be mainly attributed to the severe destruction of the RRR cell walls by the extraction system and the excellent dissolving ability of novel HDESs for anthraquinones. 展开更多
关键词 Hydrophobic deep eutectic solvent long-chain alkanol long-chain alkyl carboxylic acid One-pot extraction Anthraquinone
下载PDF
Long-chain acyl-CoA synthetase in fatty acid metabolism involved in liver and other diseases:An update 被引量:22
5
作者 Sheng Yan Xue-Feng Yang +3 位作者 Hao-Lei Liu Nian Fu Yan Ouyang Kai Qing 《World Journal of Gastroenterology》 SCIE CAS 2015年第12期3492-3498,共7页
Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer mem... Long-chain acyl-Co A synthetase(ACSL) family members include five different ACSL isoforms, each encoded by a separate gene and have multiple spliced variants. ACSLs on endoplasmic reticulum and mitochondrial outer membrance catalyze fatty acids with chain lengths from 12 to 20 carbon atoms to form acyl-Co As, which are lipid metabolic intermediates and involved in fatty acid metabolism, membrane modifications and various physiological processes. Gain- or lossof-function studies have shown that the expression of individual ACSL isoforms can alter the distribution and amount of intracellular fatty acids. Changes in the types and amounts of fatty acids, in turn, can alter the expression of intracellular ACSLs. ACSL family members affect not only the proliferation of normal cells, but the proliferation of malignant tumor cells. They also regulate cell apoptosis through different signaling pathways and molecular mechanisms. ACSL members have individual functions in fatty acid metabolism in different types of cells depending on substrate preferences, subcellular location and tissue specificity, thus contributing to liver diseases and metabolic diseases, such as fatty liver disease, obesity, atherosclerosis and diabetes. They are also linked to neurological disorders and other diseases. However, the mechanisms are unclear. This review addresses new findings in the classification and properties of ACSLs and the fatty acid metabolismassociated effects of ACSLs in diseases. 展开更多
关键词 long-chain acyl-Co A SYNTHETASE FATTY acid Prolife
下载PDF
Stool characteristics of infants receiving short-chain galactooligosaccharides and long-chain fructo-oligosaccharides:A review 被引量:7
6
作者 Petra AMJ Scholtens Dominique AM Goossens Annamaria Staiano 《World Journal of Gastroenterology》 SCIE CAS 2014年第37期13446-13452,共7页
Human milk is considered to be the optimal source of infant nutrition. Some of the benefits of breastfeeding have been ascribed to human milk oligosaccharides(HMO). For instance, HMO can affect faecal characteristics ... Human milk is considered to be the optimal source of infant nutrition. Some of the benefits of breastfeeding have been ascribed to human milk oligosaccharides(HMO). For instance, HMO can affect faecal characteristics such as stool consistency and stool frequency. Such effects on stool characteristics can be beneficial for young infants as hard stools and even constipation is common in that age group. Prebiotics in infant milk formulas have been introduced to exert similar functionalities. A specific mixture of prebiotics consists of a combination of short chain galacto-oligosaccharides and long-chain fructo-oligosaccharides(scGOS/lcFOS) in a ratio of 9:1. This specific mixture has been developed to closely resemble the molecular size composition of HMO. Many studies have been done with scGOS/lcFOS, and indicators for digestive comfort have often been included as secondary outcomes. This review summarizes the effects of scGOS/lcFOS(9:1) on stool consistency,stool frequency and transit time in healthy term and preterm infants. In several of the studies with scGOS/lcFOS in a ratio of 9:1 in infant milk formulas, positive effects of this mixture on stool characteristics such as stool consistency and stool frequency were observed. As stool consistency was shown to be correlated to whole gut transit time, scGOS/lcFOS can be hypothesised to have a role in reducing the risk of constipation. 展开更多
关键词 Short-chain galactooligosaccharides long-chain fructooligosaccharides Stool consistency Stool frequency INFANTS
下载PDF
Application of long-chain alkenones and U_(37)~k values for paleotemperature estimation in the Arctic Chukchi Sea-Bering Sea area 被引量:4
7
作者 Lu Bing, Chen Ronghua, Wang Zipan, Chen Jianfang, Liu Zhensheng 1. Key Laboratory of Submarine Geosciences, Second Institute of Oceanography, State Oceanic Administration, Hangzhou 310012, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2001年第3期371-381,共11页
Long-chain alkenones were detected in samples of sea surface sediments from the Chukchi Sea and the Bering Sea areas, the Arctic Pole. The analysis result indicates that C37:3 methylketone is predominate in the long-c... Long-chain alkenones were detected in samples of sea surface sediments from the Chukchi Sea and the Bering Sea areas, the Arctic Pole. The analysis result indicates that C37:3 methylketone is predominate in the long-chain alkenones from the Chukchi and Bering Sea sediments. The abundance of C37 to C39 unsaturated alkenones changes in an order of C37 > C38 > C39. Based on C37 /C38 ratio, the detected organism precursors of the long-chain alkenones are mainly coccolithophrid (Emiliania huxleyi). By the calibration relationship between U37k and U37k indices, the sea surface paleotemperature in these seas is estimated. The estimated values of U37k vary from 4.147℃ to 5.706℃ , with a mean value of 5.092℃. 展开更多
关键词 long-chain alkenone SST U37k the Chukchi Sea the Bering Sea PALEOTEMPERATURE
下载PDF
Application of the Long-Chain Linear Polyester in Plastification of PVC 被引量:3
8
作者 李岩 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2008年第1期100-104,共5页
The plastification modification of poly (vinyl chloride) (PVC) with the long-chain linear polyester (LP) synthesized by linear dodecanedioic acid (DC12) or tetradecanedioic acid (DC14) with different diols i... The plastification modification of poly (vinyl chloride) (PVC) with the long-chain linear polyester (LP) synthesized by linear dodecanedioic acid (DC12) or tetradecanedioic acid (DC14) with different diols is investigated. The processing characteristics, mechanical properties and extraction property of the PVC/LP blends in different solvents (xylene, cyclohexane, ethanol) were also studied in detail. All results were compared with that of the PVC plasticized with dioctyl phthalate (DOP). The results show that the molecular weight, molecular structure and loading of LP greatly influence the mechanical properties of the PVC/LP blends. The processability and the mechanical properties of PVC plasticized by LP are comparable to those of the corresponding PVC/DOP blends. However, the PVC/LP blends posses much better migration resistance property than the corresponding PVC/DOP blends, which makes the long-chain linear polyester become a very good plasticizer candidate for PVC industry. 展开更多
关键词 poly (vinyl chloride) long-chain linear polyester DOP PLASTICIZER migration resistance
下载PDF
Impacts of the unsaturation degree of long-chain fatty acids on the volatile fatty acid profiles of rumen microbial fermentation in goats in vitro 被引量:3
9
作者 GAO Jian WANG Meng-zhi +3 位作者 JING Yu-jia SUN Xue-zhao WU Tian-yi SHI Liang-feng 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第12期2827-2833,共7页
This study investigated the impacts of the degree of unsaturation (unsaturity) of long-chain fatty acids on volatile fatty acid (VFA) profiles of rumen fermentation in vitro. Six types of long-chain fatty acids, i... This study investigated the impacts of the degree of unsaturation (unsaturity) of long-chain fatty acids on volatile fatty acid (VFA) profiles of rumen fermentation in vitro. Six types of long-chain fatty acids, including stearic acid (C18:0, control group), oleic acid (C18:1, n-9), linoleic acid (C18:2, n-6), a-linolenic acid (C18:3, n-3), arachidonic acid (C20:4, n-6) and eicosapentaenoic acid (C20:5, n-3), were tested. Rumen fluid from three goats fitted with ruminal fistulae was used as inoculum and the inclusion rate of long-chain fatty acid was at 3% (w/w) of substrate. Samples were taken for VFA analysis at 0, 3, 6, 9, 12, 18 and 24 h of incubation, respectively. The analysis showed that there were significant differences in the total VFA among treatments, sampling time points, and treatment×time point interactions (P〈0.01). a-Linolenic acid had the highest total VFA (P〈0.01) among different long-chain fatty acids tested. The molar proportion of acetate in total VFA significantly differed among treatments (P〈0.01) and sampling time points (P〈0.01), but not treatment×time point interactions (P〉0.05). In contrast, the molar proportion of propionate did not differ among treatments during the whole incubation (P〉0.05). However, for butyrate molar proportions, significant differences were found not only among sampling time points but also among treatments and treatment×time point interactions (P〈0.01), with eicosapentaenoic acid having the highest value (P〈0.01). Additionally, no statistically significant differences were found in the acetate to propionate ratios among treatments groups (P〉0.05), even the treatments stearic acid and a-linolenic acid were numerically higher than the others. The inclusion of 3% long-chain unsaturated fatty acids differing in the degree of unsaturation brought out a significant quadratic regression relation between the total VFA concentration and the double bond number of fatty acid. In conclusion, the a-linolenic acid with 3 double bonds appeared better for improving rumen microbial fermentation and the total VFA concentration. 展开更多
关键词 volatile fatty acid unsaturation degree long-chain fatty acid in vitro fermentation
下载PDF
Paleoenvironmental implications of Holocene long-chain n-alkanes on the northern Bering Sea Slope 被引量:2
10
作者 ZHANG Haifeng WANG Rujian XIAO Wenshen 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2017年第8期137-145,共9页
The records of high-resolution terrestrial biological markers (biomarkers) from Core B2-9 from the northern Bering Sea Slope over the last 9.6 ka BP were presented in the study. Variations in input of terrestrial lo... The records of high-resolution terrestrial biological markers (biomarkers) from Core B2-9 from the northern Bering Sea Slope over the last 9.6 ka BP were presented in the study. Variations in input of terrestrial long-chain n-alkanes (referred to as n-alkanes) and vegetation structure in their source regions were investigated. The results show that the nCz7 is the main carbon peak and has the greatest contribution rate of the total n-alkane content; this might be related to the abundance of woody plants and their spatial distribution in the source region, nC23 is another n-alkane having a relatively high content; this was mainly derived from submerged plants widespread along the coastal areas in the northern hemisphere. Total n-alkane content dropped quickly at ca. 7.8 ka BP, ca. 6.7 ka BP and ca. 5.4 ka BP, and was followed by four relatively stable stages mostly controlled by sea-level rise, climate change and vegetation distribution in the source region. Variation in carbon preference index (CPI) indicates that the n-alkanes primarily originated from higher land plants, and the average chain length (ACL) and nCa1/nC27 ratio reveal the relatively stable presence of woody/herbaceous plants during the Holocene, and dominate woody plants in most of the time. Simultaneous variation in total n-alkane content, nC27 content and its contribution, CPI, ACL and nC31/nC27 ratio over several short periods suggest that the growth rate of the woody plant n-alkane contribution was lower than that of herbaceous plants and fossil n-alkanes under the particular climatic conditions of the source region. 展开更多
关键词 Bering Sea terrestrial input long-chain n-alkanes vegetation structure HOLOCENE
下载PDF
Effects of long-chain fatty acid supplementation on the growth performance of grower and finisher pigs: a meta-analysis 被引量:2
11
作者 Zhi Li Bocheng Xu +1 位作者 Zeqing Lu Yizhen Wang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2019年第4期1037-1048,共12页
Background: Supplementation of feed with long-chain fatty acids(LCFAs) during the grower and finisher phases has long been discussed as a growth promotion strategy in pigs, but its effects are inconsistent. The purpos... Background: Supplementation of feed with long-chain fatty acids(LCFAs) during the grower and finisher phases has long been discussed as a growth promotion strategy in pigs, but its effects are inconsistent. The purpose of our study was to comprehensively evaluate its effects on the growth performance based on the average daily gain(ADG), average daily feed intake(ADFI) and gain: feed(G:F) ratio and to unveil the roles of the basal diet, LCFA concentration and LCFA saturation.Results: We searched the Pub Med and Web of Science databases(articles published from Jan 1 st, 2000, to Sep 30 th,2018;restricted to English) and compared LCFA-supplemented diets with control diets. We retrieved 2346 studies, 18 of which(1314 pigs, 26 records) were eligible for our analysis. We used a random-effects model to calculate the weighted mean differences(WMDs) and 95% confidence intervals(CIs). LCFA supplementation in the grower-finisher phase improved the ADG(WMD = 41.74 g/d, 95% CI: 8.81 to 74.66, P = 0.013) and G:F ratio(WMD = 0.019, 95% CI: 0.006 to 0.032, P = 0.003). For supplementation solely in the finisher phase, we found a similar performance in the ADG(WMD = 39.93 g/d, 95% CI: 26.48 to 53.38, P < 0.001) and G:F ratio(WMD = 0.019, 95% CI: 0.006 to 0.032, P < 0.001) but a reduction in the ADFI(WMD =-83.863 g/d, 95% CI:-156.157 to-11.569, P = 0.023). Specifically, approximately 5%LCFA supplementation in the finisher phase had significant effects on the ADG(WMD = 51.385 g/d, 95% CI: 35.816 to66.954, P < 0.001), ADFI(WMD =-102.869 g/d, 95% CI:-189.236 to-16.502, P = 0.02) and G:F ratio(WMD = 0.028, 95%CI: 0.018 to 0.039, P < 0.001), whereas a concentration of approximately 1% exhibited no effects.Conclusions: Overall, regardless of the basal diet and saturation, LCFA supplementation greatly improves the growth performance of grower and finisher pigs, primarily by increasing the energy density. 展开更多
关键词 Energy density Finisher PIG GROWER PIG Growth PERFORMANCE long-chain FATTY acid META-ANALYSIS Production PERFORMANCE
下载PDF
Study of Sorption Properties of Anion Exchangers with Long-Chained Cross-Linking Agents for Tungsten Hydrometallurgy 被引量:2
12
作者 A.G.Kholmogorov O.N.Kononova +2 位作者 S.V.Kachin O.P.Kalyakina G.L.Pashkov 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2000年第3期241-246,共6页
The macroporous anion exchangers with long-chained cross-linking agents were investigated for the tungsten recovery from salt solutions.The physical-chemical characteristics of these sorbents were studied by means of ... The macroporous anion exchangers with long-chained cross-linking agents were investigated for the tungsten recovery from salt solutions.The physical-chemical characteristics of these sorbents were studied by means of sorption-desorption experiment aswell as electron and IR-spectroscopy.The anion exchangers on the basis of macroporous copolymers of methylacrylate and divinyl-ester of diethyleneglycol or tetravinyl-ester of pentaerythritol possess the exchange capacity to tungsten 2--5 times greater than the porous anion exchangers on the basis of styrene and divinylbenzene,therefore they can be used for selective tungsten recovery from comulex salt solutions. 展开更多
关键词 anion exchangers macroporous structure long-chained cross-linking agents tungsten recovery salt solution
下载PDF
Roles of Long-chain Acyl Coenzyme A Synthetase in Absorption and Transport of Fatty Acid 被引量:2
13
作者 Fan Gao Xue-feng Yang +4 位作者 Nian Fu Yang Hu Yan Ouyang Kai Qing 《Chinese Medical Sciences Journal》 CAS CSCD 2016年第1期62-64,共3页
Long-chain acyl coenzyme A synthetase(ACSL) is a member of the synthetase family encoded by a multigene family;it plays an important role in the absorption and transport of fatty acid.Here we review the roles of ACSL ... Long-chain acyl coenzyme A synthetase(ACSL) is a member of the synthetase family encoded by a multigene family;it plays an important role in the absorption and transport of fatty acid.Here we review the roles of ACSL in the regulating absorption and transport of fatty acid,as well as the connection between ACSL and some metabolic diseases. 展开更多
关键词 long-chain acyl coenzyme A synthetase fatty acid ABSORPTION transport
下载PDF
Identification of a Long-Chain Fatty Acid Elongase from Nannochloropsis sp. Involved in the Biosynthesis of Fatty Acids by Heterologous Expression in Saccharomyces cerevisiae 被引量:1
14
作者 GUO Minrui CHEN Guogang +1 位作者 CHEN Jiluan ZHENG Minggang 《Journal of Ocean University of China》 SCIE CAS CSCD 2019年第5期1199-1206,共8页
The marine microalga Nannochloropsis sp.contains various elongases and desaturases that are critical for biosynthesis of polyunsaturated fatty acids.A full-length cDNA encoding a long-chain fatty acid elongase,named N... The marine microalga Nannochloropsis sp.contains various elongases and desaturases that are critical for biosynthesis of polyunsaturated fatty acids.A full-length cDNA encoding a long-chain fatty acid elongase,named Ns FAE,was cloned from Nannochloropsis sp..The open reading frame of Ns FAE(GenBank accession no.MF680548)consisted of 1068 bp and encoded a predicted protein of 355 amino acids with molecular mass 38.8 k Da.The deduced polypeptide showed 43%–44%identity to fatty acyl elongases from other algae.RT-PCR experiments indicated that the Ns FAE gene exhibited the highest expression in Nannochloropsis sp.at 72 h(i.e.,during the third growth stage)and the expression was significantly lower in the other four growth stages.Plasmid p Ns FAE-CRISPR and a recombinant DNA fragment(ADH1p-Ns FAE-CYCt)were transformed into Saccharomyces cerevisiae strain BY4742 using the CRISPR-Cas system.Yeast transformants containing Ns FAE produced three fatty acids not normally present in wild-type BY4742-linoleic acid,linolenic acid and eicosadienoic acid-indicating that Ns FAE encodes a functional elongase enzyme. 展开更多
关键词 NANNOCHLOROPSIS sp. long-chain FATTY ACID ELONGASE Saccharomyces cerevisiae FATTY ACID production
下载PDF
The effects of the unsaturated degree of long-chain fatty acids on the rumen microbial protein content and the activities of transaminases and dehydrogenase in vitro 被引量:4
15
作者 GAO Jian JING Yu-jia +2 位作者 WANG Meng-zhi SHI Liang-feng LIU Shi-min 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第2期424-431,共8页
This study investigated the effects of the degree of unsaturation(unsaturity) of long-chain fatty acids on microbial protein content and the activities of transaminases and dehydrogenase in vitro using goat rumen fl... This study investigated the effects of the degree of unsaturation(unsaturity) of long-chain fatty acids on microbial protein content and the activities of transaminases and dehydrogenase in vitro using goat rumen fluid as the cultural medium.Six types of fatty acids,stearic acid(C18:0,group A,control group),oleic acid(C18:1,n-9,group B),linoleic acid(C18:2,n-6,group C),α-linolenic acid(C18:3,n-3,group D),arachidonic acid(C20:4,n-6,group E),and eicosapentaenoic acid(C20:5,n-3,group F),were tested,and the inclusion ratio of each fatty acid was 3%(w/w) in total of culture substrate.Samples were taken at 0,3,6,9,12,18 and 24 h,respectively,during culture for analyses.Compared with stearic acid,linoleic acid,a-linolenic acid,and arachidonic acid increased the bacterial protein content,while oleic acid and eicosapentaenoic acid had no significant effects;the protozoal protein content was reduced for all the unsaturated fatty acids,and the magnitude of the reduction appeared to be associated with the degree of unsaturity of fatty acids.The total microbial protein content was dominantly accounted by the protozoal protein content(about 4-9 folds of the bacterial protein),and only increased by linoleic acid,but reduced by oleic acid,arachidonic acid and eicosapentaenoic acid.There were no significant effects in the activities of both glutamic oxaloacetic transaminase(GOT) and glutamic-pyruvic transaminase(GPT) for all the other fatty acids,except for arachidonic acid which enhanced GOT activity and oleic acid which enhanced GPT activity.The total dehydrogenase activity was positively correlated with the degree of unsaturation of fatty acids.In conclusion,the inclusion of 3%of long-chain unsaturated fatty acids increased bacterial protein content,whereas reduced protozoal protein content and enhanced dehydrogenase activity.The fatty acids with more than three double bonds had detrimental effects on the microbial protein content.This work demonstrates for the first time the effect rule of the unsaturation degree of long-chain fatty acids on the rumen microbial protein in vitro. 展开更多
关键词 long-chain fatty acid rumen microbes goats protein concentration
下载PDF
Effect of alkali metals on the performance of CoCu/TiO_2 catalysts for CO_2 hydrogenation to long-chain hydrocarbons 被引量:4
16
作者 Zhibiao Shi Haiyan Yang +7 位作者 Peng Gao Xinqing Chen Hongjiang Liu Liangshu Zhong Hui Wang Wei Wei Yuhan Sun 3a] 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2018年第8期1294-1302,共9页
CoCu/TiO_2 catalysts promoted using alkali metals(Li, Na, K, Rb, and Cs) were prepared by the homogeneous deposition-precipitation method followed by the incipient wetness impregnation method. The influences of the ... CoCu/TiO_2 catalysts promoted using alkali metals(Li, Na, K, Rb, and Cs) were prepared by the homogeneous deposition-precipitation method followed by the incipient wetness impregnation method. The influences of the alkali metals on the physicochemical properties of the CoCu/TiO_2 catalysts and the catalytic performance for CO_2 hydrogenation to long-chain hydrocarbons(C_(5+))were investigated in this work. According to the characterization of the catalysts based on X-ray photoelectron spectroscopy, X-ray diffraction, CO_2 temperature-programmed desorption(TPD), and H_2-TPD, the introduction of alkali metals could increase the CO_2 adsorption and decrease the H_2 chemisorption, which could suppress the formation of CH_4, enhance the production of C_(5+), and decrease the hydrogenation activity. Among all the promoters, the Na-modified CoCu/TiO_2 catalyst provided the maximum C_(5+) yield of 5.4%, with a CO_2 conversion of 18.4% and C_(5+) selectivity of42.1%, because it showed the strongest basicity and a slight decrease in the amount of H_2 desorption;it also exhibited excellent catalytic stability of more than 200 h. 展开更多
关键词 Carbon dioxide hydrogenation long-chain hydrocarbons Carbon dioxide Fischer-Tropsch synthesis Alkali metal promoters Cobalt-coper based catalysts
下载PDF
Modification of Cellulose by Hydrophobic Long-chain Molecules: Advances and Prospects 被引量:4
17
作者 Yuyuan Wang Haishan Zhang +5 位作者 Leyi Lin Rui Wu Xiaohui Wang Junli Ren Chuanfu Liu Xiaoying Wang 《Paper And Biomaterials》 2020年第3期31-43,共13页
Cellulose,a natural polymer material with abundant natural sources,is non-toxic,renewable,and biodegradable,making it one of the most promising green materials.Its inherent hydrophilicity dramatically limits the devel... Cellulose,a natural polymer material with abundant natural sources,is non-toxic,renewable,and biodegradable,making it one of the most promising green materials.Its inherent hydrophilicity dramatically limits the development and application of cellulose products.Hydrophobic modification can significantly change cellulose properties and endow it with additional functions depending on the types of modifying molecules.Controlled modification of cellulose by long-chain hydrophobic molecules is challenging.Significant advances took advantage of new reaction systems and copolymerization.This paper reviews recent innovations in long-chain cellulose hydrophobic modification.A brief value-adding assessment provides a reference for green changes of cellulose to make it fit for future applications. 展开更多
关键词 CELLULOSE HYDROPHOBIC chemical modification long-chain
下载PDF
Synthesis and Properties of Dendritic Long-Chain Esters as Crude Oil Flow Improver Additives 被引量:1
18
作者 Li Cuiqin Sun Peng +1 位作者 Shi Weiguang Wang Jun 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第1期83-91,共9页
The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amid... The efficiencies of 6 kinds of macromolecules with dendritic structure in improving the flow properties of crude oil were investigated. The dendritic additives were synthesized using low-generation dendritic poly(amidoamine) and alkyl longchain acrylic esters as starting materials, and their structures were characterized by the Fourier transform infrared spectroscopy, 1H-nuclear magnetic resonance and elemental analysis. The effects on the pour point and rheological properties of crude oil samples were studied. Efficiencies of dendritic long-chain esters were not only influenced by the alky chain length, but also by the generation of dendrimer. The longer the alkyl chain of dendritic long-chain ester was, the better the effect in the reduction of pour point and apparent viscosity was. Efficiencies of 1.5 generation dendritic long-chain ester with 8 branched chains for the reduction of pour point and apparent viscosity were superior to those of 0.5 generation dendritic long-chain ester with 4 branched chains. Under the same conditions, efficiencies of 1.5 generation dendritic eighteen ester were superior to those of other 1.5 generation dendritic long-chain esters for the reduction of pour point and viscosity of crude oil. 展开更多
关键词 dendrimer flow improver dendritic long-chain ester pour point depressant
下载PDF
Synthesis of Long-Chain SpirobenzopyransBearing a Monoazacrown ether
19
作者 Sheng Hua LIU Cheng Tat WU(Department of Chemistry, Wuhan University, Wuhan 430072) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第1期15-16,共2页
Two new long-chain spirobenzopyrans and their crowned derivatives were designed and synthesized.
关键词 SYNTHESIS long-chain SPIROBENZOPYRAN monoazacrown ether
下载PDF
Study on Extracting Rare Earth from Sulfate System by Long-Chain Fatty Acid
20
作者 Xu Yanhui Zhao Zengqi Liu Quansheng 《Journal of Rare Earths》 SCIE EI CAS CSCD 2004年第z1期32-34,共3页
The extraction of rare earths by long-chain fatty acid in kerosene from sulphate system was described.It was demonstrated from the experimental results that the ratio of kerosene: fatty acid: isooctanol = 55 : 30: 15 ... The extraction of rare earths by long-chain fatty acid in kerosene from sulphate system was described.It was demonstrated from the experimental results that the ratio of kerosene: fatty acid: isooctanol = 55 : 30: 15 ( V/V),By the saturation capability method and the slope method, the extracted reaction mechanism of the extraction of rare earth was studied.It is shown that the extraction reaction conform to the cation exchange reaction mechanism.The extracted sequence of rare earth was determined in this system and it is shown that there is no tetrad effect and the position of yttrium is between lanthanum and cerium. 展开更多
关键词 extraction long-chain FATTY ACID RARE earths
下载PDF
上一页 1 2 96 下一页 到第
使用帮助 返回顶部