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
The present study presents an assessment of the interrelations between long-chain branching,specific nucleation,and end-use properties of polypropylene blends:blends of linear polypropylene(L-PP)and long-chain branche...The present study presents an assessment of the interrelations between long-chain branching,specific nucleation,and end-use properties of polypropylene blends:blends of linear polypropylene(L-PP)and long-chain branched polypropylene(LCB-PP)modified by a specificβ-nucleating agent(NA).Specimens with various LCB-PP compositions with and without NA were prepared under complex flow fields by injection molding.Wide-angle X-ray scattering was employed to capture the X-ray patterns of both the skin and core of the specimens,determining the overall crystallinity and amounts of individual polymorphs.The increasing content of LCB-PP andγ-phase,at the same time,in the blends is reflected in both increasing crystallinity and improved mechanical properties,namely,yield stress and Young’s modulus.On the other hand,the composition of the blends had no significant effect on the impact strength,except for nucleated L-PP.It has been demonstrated that adding a relatively small amount of LCB-PP is sufficient to modify the mechanical properties of linear polypropylene.Even a very small amount of LCB-PP in the L-PP suppressed the effectiveness of NA.展开更多
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
Dietary supplementation with plant-derivedα-linolenic acid(ALA)has the potential to alleviate the insufficient intake of global n-3 long-chain polyunsaturated fatty acids(n-3 LCPUFAs),but faces the bottleneck of high...Dietary supplementation with plant-derivedα-linolenic acid(ALA)has the potential to alleviate the insufficient intake of global n-3 long-chain polyunsaturated fatty acids(n-3 LCPUFAs),but faces the bottleneck of highβ-oxidation consumption,oxidative susceptibility,and low conversion efficiency.The current study investigated how flax lignans with different degrees of polymerization and glycosylation affect the conversion of ALA to n-3 LCPUFAs in mice over 35 days of administering sunflower phospholipid-stabilized flaxseed oil nanoemulsions.Results showed that flax lignan macromolecules(FLM)increased hepatic protein expression of elongase of very long chain fatty acid 5(Elovl5,24.2%)and fatty acid desaturase 2(Fads2,44.7%),thereby positively regulating ALA conversion pathways and raising serum eicosapentaenoic acid(EPA)levels(52.7%)via liver lipid re-efflux.Secoisolariciresinol diglucoside(SDG)enhanced ALA desaturation by upregulating hepatic protein expression of Fads1(30.4%)and Fads2(45.6%),increasing serum EPA levels(55.9%)and hepatic docosahexaenoic acid(DHA)levels(10%).Secoisolariciresinol(SECO)elevated hepatic protein expression of Elovl2(30.7%),Elovl5(11.7%),Fads1(37.9%),and Fads2(24.1%),but also increased carnitine palmitoyltransferase 1a(45.2%),leading to decreased ALA,EPA,and DHA levels in serum and liver.Therefore,in comparison,FLM and SDG emerge as the dominant structural units that positively regulate the conversion of ALA.These findings lay a groundwork for designing precise dietary delivery systems to enhance the conversion to n-3 LCPUFAs.展开更多
Long-chain polyamides(LCPAs)are a class of bio-based polymers that can bridge conventional polyolefins and polycondensates.In this work,taking the advantage of the amphiphilic nature of polyamide 1012(PA1012),membrane...Long-chain polyamides(LCPAs)are a class of bio-based polymers that can bridge conventional polyolefins and polycondensates.In this work,taking the advantage of the amphiphilic nature of polyamide 1012(PA1012),membranes were prepared by using a non-conventional phase separation approach,namely,mixed‘non-solvents’evaporation induced phase separation(MNEIPS).PA1012 can be dissolved in a mixture of polar and non-polar solvents,both of which are non-solvents of PA1012.During the sequential evaporation of the two solvents,the phase separation of PA1012 occurred,inducing the formation of porous structures.We investigated the process of membrane formation in detail,with a specific focus on the liquid-liquid and liquid-solid phase transitions involved.Moreover,we studied the influence of critical factors,such as polymer concentration and mixed-solvent ratio,on the morphologies and properties of PA1012 membranes.This study provides new insights into the development of porous materials based on long-chain polycondensates.展开更多
BACKGROUND Ferroptosis is a newly recognized form of regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species.It has been extensively studied in various diseases,including can...BACKGROUND Ferroptosis is a newly recognized form of regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species.It has been extensively studied in various diseases,including cancer,Parkinson’s disease,and stroke.However,its precise role and underlying mechanisms in ischemia/reperfusion injury,particularly in the intestinal ischemia-reperfusion(IIR),remain unclear.In current work,we aimed to investigate the participation of histone lactylation during IIR progression.AIM To investigate the role of mitochondrial alanyl-tRNA synthetase 2(AARS2)in ferroptosis and its epigenetic regulation of acyl-CoA synthetase long-chain family member 4(ACSL4)through histone lactylation during IIR injury.METHODS We established a mouse model to mimic IIR and conducted AARS2 knockdown as treatment.The expression of AARS2 in intestinal tissues was measured by western blot.The integrity of intestinal tissues was detected by hematoxylin and eosin staining,serum fatty acid-binding protein,protein levels of ZO-1 and occluding.An in vitro hypoxia-reperfusion(H/R)cell model was established,and cell viability was measured by CCK-8.The in vitro and in vivo ferroptosis was determined by the accumulation of Fe2+and malondialdehyde(MDA).The epigenetic regulation of ACSL4 by AARS2 was detected by chromatin immunoprecipitation(ChIP)assay and luciferase reporter assay.RESULTS We observed a notable elevated AARS2 level in intestinal tissue of mice in IIR model group,which was reversed by shAARS2 treatment.Knockdown of AARS2 repressed alleviated intestinal barrier disruption and repressed the accumulation of ferroptosis biomarker Fe2+and MDA during IIR.The in vitro results showed that shAARS2 alleviated impaired cell viability caused by H/R,as well as repressed ferroptosis.Knockdown of AARS2 notably downregulated the RNA and protein expression of ACSL4.Mechanistically,knockdown of AARS2 downregulated the enrichment of H3K18 La modification on AARS2,as well as suppressed its promoter activity.Overexpression of AARS2 could abolish the protective effects of shACSL4 in vitro.CONCLUSION The elevation of AARS2 during IIR led to cell ferroptosis via epigenetically upregulating the expression of ACSL4.Our findings presented AARS2 as a promising therapeutic target for IIR.展开更多
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
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
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
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
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
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
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
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
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
The detection of long-chain branches（LCB） in polyethylene is of considerable importance as the processing properties of polyethylene are strongly affected by even a small amount of LCB. While the conventional charac...The detection of long-chain branches（LCB） in polyethylene is of considerable importance as the processing properties of polyethylene are strongly affected by even a small amount of LCB. While the conventional characterization techniques such as GPC-MALS and13 C NMR fail or take very long time to detect low content of LCB, we turn to the rheological method, which is more sensitive to LCB. In our study, we performed oscillatory shear test, creep test and stress relaxation test on two series of metallocene linear low density polyethylene（LLDPE）, revealing that the resins with LCB show higher zero-shear-rate viscosity, retarded relaxation and higher flow activation energy than those without or with less LCB. The resins with LCB showed shear thinning at very low shear rate and their zero-shear-rate viscosities were obtained via creep test. The content of LCB was quantitatively estimated from the flow activation energy. In addition, the modulus-time curves during stress relaxation of melt of the different resins obeyed the power law. The exponent of the resins with more LCB was 0.7, different from that of the resins with less LCB, around 1.7.展开更多
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
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
As a representative species of intermediate volatile organic compounds(IVOCs),long-chain alkanes are considered to be important precursors of secondary organic aerosols(SOA)in the atmosphere.This work reviews the prev...As a representative species of intermediate volatile organic compounds(IVOCs),long-chain alkanes are considered to be important precursors of secondary organic aerosols(SOA)in the atmosphere.This work reviews the previous studies on long-chain alkanes in the atmosphere:(1)the detection methods and filed observations of long-chain alkanes in both gas and particle phases are summarized briefly;(2)the laboratory studies of long chain alkanes are reviewed,the kinetic data,reaction mechanism,SOA yields,and physicochemical properties of SOA are included in detail;(3)the research progress related to model simulations of long-chain alkanes are also discussed.In addition,based on available research results,several perspective contents are proposed that can be used as a guideline for future research plans.展开更多
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
文摘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.
文摘The present study presents an assessment of the interrelations between long-chain branching,specific nucleation,and end-use properties of polypropylene blends:blends of linear polypropylene(L-PP)and long-chain branched polypropylene(LCB-PP)modified by a specificβ-nucleating agent(NA).Specimens with various LCB-PP compositions with and without NA were prepared under complex flow fields by injection molding.Wide-angle X-ray scattering was employed to capture the X-ray patterns of both the skin and core of the specimens,determining the overall crystallinity and amounts of individual polymorphs.The increasing content of LCB-PP andγ-phase,at the same time,in the blends is reflected in both increasing crystallinity and improved mechanical properties,namely,yield stress and Young’s modulus.On the other hand,the composition of the blends had no significant effect on the impact strength,except for nucleated L-PP.It has been demonstrated that adding a relatively small amount of LCB-PP is sufficient to modify the mechanical properties of linear polypropylene.Even a very small amount of LCB-PP in the L-PP suppressed the effectiveness of NA.
基金Supported by Brazilian Agencies:Conselho Nacional de Desenvolvimento Científico e TecnológicoPrograma Nacional de Cooperação Acadêmica/Coordenação de Aperfeiçoamento de Pessoal de Nível Superiorand Fundação de AmparoàPesquisa do Estado do Rio Grande do Sul.
文摘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.
基金supported by grants from the National Natural Science Foundation of China(32072267)China Agriculture Research System(CARS-14)+1 种基金National Key Research and Development Program of China(2023YFD2100404)the Innovation Group Project of Hubei Province(2023AFA042).
文摘Dietary supplementation with plant-derivedα-linolenic acid(ALA)has the potential to alleviate the insufficient intake of global n-3 long-chain polyunsaturated fatty acids(n-3 LCPUFAs),but faces the bottleneck of highβ-oxidation consumption,oxidative susceptibility,and low conversion efficiency.The current study investigated how flax lignans with different degrees of polymerization and glycosylation affect the conversion of ALA to n-3 LCPUFAs in mice over 35 days of administering sunflower phospholipid-stabilized flaxseed oil nanoemulsions.Results showed that flax lignan macromolecules(FLM)increased hepatic protein expression of elongase of very long chain fatty acid 5(Elovl5,24.2%)and fatty acid desaturase 2(Fads2,44.7%),thereby positively regulating ALA conversion pathways and raising serum eicosapentaenoic acid(EPA)levels(52.7%)via liver lipid re-efflux.Secoisolariciresinol diglucoside(SDG)enhanced ALA desaturation by upregulating hepatic protein expression of Fads1(30.4%)and Fads2(45.6%),increasing serum EPA levels(55.9%)and hepatic docosahexaenoic acid(DHA)levels(10%).Secoisolariciresinol(SECO)elevated hepatic protein expression of Elovl2(30.7%),Elovl5(11.7%),Fads1(37.9%),and Fads2(24.1%),but also increased carnitine palmitoyltransferase 1a(45.2%),leading to decreased ALA,EPA,and DHA levels in serum and liver.Therefore,in comparison,FLM and SDG emerge as the dominant structural units that positively regulate the conversion of ALA.These findings lay a groundwork for designing precise dietary delivery systems to enhance the conversion to n-3 LCPUFAs.
基金supported by the Fundamental Research Funds for the Central Universities(No.2023ZYGXZR107)the TCL Science and Technology Innovation Fund。
文摘Long-chain polyamides(LCPAs)are a class of bio-based polymers that can bridge conventional polyolefins and polycondensates.In this work,taking the advantage of the amphiphilic nature of polyamide 1012(PA1012),membranes were prepared by using a non-conventional phase separation approach,namely,mixed‘non-solvents’evaporation induced phase separation(MNEIPS).PA1012 can be dissolved in a mixture of polar and non-polar solvents,both of which are non-solvents of PA1012.During the sequential evaporation of the two solvents,the phase separation of PA1012 occurred,inducing the formation of porous structures.We investigated the process of membrane formation in detail,with a specific focus on the liquid-liquid and liquid-solid phase transitions involved.Moreover,we studied the influence of critical factors,such as polymer concentration and mixed-solvent ratio,on the morphologies and properties of PA1012 membranes.This study provides new insights into the development of porous materials based on long-chain polycondensates.
文摘BACKGROUND Ferroptosis is a newly recognized form of regulated cell death characterized by iron-dependent accumulation of lipid reactive oxygen species.It has been extensively studied in various diseases,including cancer,Parkinson’s disease,and stroke.However,its precise role and underlying mechanisms in ischemia/reperfusion injury,particularly in the intestinal ischemia-reperfusion(IIR),remain unclear.In current work,we aimed to investigate the participation of histone lactylation during IIR progression.AIM To investigate the role of mitochondrial alanyl-tRNA synthetase 2(AARS2)in ferroptosis and its epigenetic regulation of acyl-CoA synthetase long-chain family member 4(ACSL4)through histone lactylation during IIR injury.METHODS We established a mouse model to mimic IIR and conducted AARS2 knockdown as treatment.The expression of AARS2 in intestinal tissues was measured by western blot.The integrity of intestinal tissues was detected by hematoxylin and eosin staining,serum fatty acid-binding protein,protein levels of ZO-1 and occluding.An in vitro hypoxia-reperfusion(H/R)cell model was established,and cell viability was measured by CCK-8.The in vitro and in vivo ferroptosis was determined by the accumulation of Fe2+and malondialdehyde(MDA).The epigenetic regulation of ACSL4 by AARS2 was detected by chromatin immunoprecipitation(ChIP)assay and luciferase reporter assay.RESULTS We observed a notable elevated AARS2 level in intestinal tissue of mice in IIR model group,which was reversed by shAARS2 treatment.Knockdown of AARS2 repressed alleviated intestinal barrier disruption and repressed the accumulation of ferroptosis biomarker Fe2+and MDA during IIR.The in vitro results showed that shAARS2 alleviated impaired cell viability caused by H/R,as well as repressed ferroptosis.Knockdown of AARS2 notably downregulated the RNA and protein expression of ACSL4.Mechanistically,knockdown of AARS2 downregulated the enrichment of H3K18 La modification on AARS2,as well as suppressed its promoter activity.Overexpression of AARS2 could abolish the protective effects of shACSL4 in vitro.CONCLUSION The elevation of AARS2 during IIR led to cell ferroptosis via epigenetically upregulating the expression of ACSL4.Our findings presented AARS2 as a promising therapeutic target for IIR.
基金Supported by National Natural Science Foundation of China,No.81373465
文摘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.
文摘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.
基金This study was supported by the First Chinese National Scientific Observation for the Arctic the Development Program of NKBR
文摘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℃.
基金financially supported by the Graduate Student Innovation Project of Jiangsu Province,China (KYLX15_1377)the Natural Science Foundation of Jiangsu Province,China (BK20151312)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD),China
文摘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.
基金supported by the Key Program of the National Natural Science Foundation of China(grant#3163000269)National Special Fund for Modern Industrial Technology System(grant#CARS-35)Major Science and Technology Special Fund of Zhejiang Province(grant#2015C02022)
文摘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.
基金the Engineering Developing Foundation of Tongji University
文摘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.
基金Supported by the National Natural Science Foundation of China(81373465)
文摘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.
基金supported by the Basic Scientific Fund for National Public Research Institutes of China (No. 2016Q07)
文摘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.
基金The National Natural Science Foundation of China under contract Nos 41030859,41506223,CHINARE2017-03-02 and IC201105the Geological Investigation Project of China Geological Survey under contract Nos 12120113006200 and 1212011120044
文摘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.
基金supported by the National Natural Science Foundation of China (No. 21374054)the Sino-GermanCenter for Research Promotion
文摘The detection of long-chain branches（LCB） in polyethylene is of considerable importance as the processing properties of polyethylene are strongly affected by even a small amount of LCB. While the conventional characterization techniques such as GPC-MALS and13 C NMR fail or take very long time to detect low content of LCB, we turn to the rheological method, which is more sensitive to LCB. In our study, we performed oscillatory shear test, creep test and stress relaxation test on two series of metallocene linear low density polyethylene（LLDPE）, revealing that the resins with LCB show higher zero-shear-rate viscosity, retarded relaxation and higher flow activation energy than those without or with less LCB. The resins with LCB showed shear thinning at very low shear rate and their zero-shear-rate viscosities were obtained via creep test. The content of LCB was quantitatively estimated from the flow activation energy. In addition, the modulus-time curves during stress relaxation of melt of the different resins obeyed the power law. The exponent of the resins with more LCB was 0.7, different from that of the resins with less LCB, around 1.7.
文摘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.
基金the National Natural Science Foundation of China (Grant Nos.: 81673394 and 82073811)the Fundamental Research Funds for the Central Universities (Grant No.: 2042020kf1010)the Large-scale Instrument and Equipment Sharing Foundation of Wuhan University (Grant No.: LF20170838)
文摘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.
基金supported by the Postdoctoral Research Foundation of China(No.2019M660752)Beijing Municipal Commission of Education(No.Z181100005418015)the National Natural Science Foundation of China(Nos.91744204,41822703)
文摘As a representative species of intermediate volatile organic compounds(IVOCs),long-chain alkanes are considered to be important precursors of secondary organic aerosols(SOA)in the atmosphere.This work reviews the previous studies on long-chain alkanes in the atmosphere:(1)the detection methods and filed observations of long-chain alkanes in both gas and particle phases are summarized briefly;(2)the laboratory studies of long chain alkanes are reviewed,the kinetic data,reaction mechanism,SOA yields,and physicochemical properties of SOA are included in detail;(3)the research progress related to model simulations of long-chain alkanes are also discussed.In addition,based on available research results,several perspective contents are proposed that can be used as a guideline for future research plans.
基金financially supported by the Innovation Foundation for Undergraduate of Yangzhou University,China (201311117034)the Domestic Cooperative Innovation ofIndustry-University-Research(XT20140012)the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD),China
文摘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.
