To determine the effects of plant-based meat analogues on the metabolic health and the possible mechanisms,mice were fed with a real pork diet(AP),a real beef diet(AB),a plant-based pork analogue diet(PP)and plant-bas...To determine the effects of plant-based meat analogues on the metabolic health and the possible mechanisms,mice were fed with a real pork diet(AP),a real beef diet(AB),a plant-based pork analogue diet(PP)and plant-based beef analogue diet(PB)for 68 days.Compared with real meat,the plant-based meat analogues increased food and energy intake,body weight,white fat and liver weight and caused adipocyte hypertrophy,hepatic lipid droplet accumulation,and inflammatory responses in mice.Metabolomics revealed that plantbased meat analogues altered the composition of serum metabolites,which regulated lipid metabolism homeostasis.The PB diet upregulated gene expression related to lipid synthesis,lipolysis and adipocyte differentiation while the PP diet upregulated expression of lipolysis-related genes but downregulated expression of adipocyte differentiation-related genes in white adipose tissue.Meanwhile,both PP and PB diets upregulated lipid influx-and synthesis-related genes but downregulated lipid oxidation-related genes in liver.The specific metabolite biomarkers may affect fat accumulation mainly by direct lipid metabolism pathways or indirect amino acid metabolism,protein digestion and absorption,bile secretion,aminoacyl-tRNA biosynthesis,neuroactive ligand-receptor interaction and ABC transporters pathways.These findings provide a new insight into understanding the differences in nutritional functions of meat and plant-based meat analogues.展开更多
Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a r...Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a range of characterization techniques including Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS),this work discloses the process of replacement of K^(+)by NH4^(+)in the interstitial spaces of the CoFe PBA by a hot aqueous urea solution,which influences the transformation of PBAs under further heat treatment and the OER performance of the deriva tives.After heat treatment at 400℃ under Ar flow,high-resolution transmission electron microscopy(HRTEM) images reveal that CoFe alloy nanoparticles grew on the crystalline cubes of CoFe PBA with K^(+),while CoFe PBA cubes with NH4^(+)become amorphous.Besides,the derivative of CoFe PBA with NH4^(+)(Ar-U-CoFe PBA) performs better than the derivative of CoFe PBA with K^(+)(Ar-CoFe PBA) in OER,registering a lower overpotential of 305 mV at 10 mA cm^(-2),a smaller Tafel slope of 36.1 mV dec^(-1),and better stability over a testing course of 20 h in 1.0 M KOH.A single-cell alkaline electrolyzer,using Ar-U-CoFe PBA and Pt/C for the anodic and cathodic catalyst,respectively,requires an initial cell voltage of 1.66 V to achieve 100 mA cm^(-2)at 80℃,with negligible degradation after100 h.展开更多
The Qarhan Salt Lake(QSL)in western China is K-Sr-Li-B-Br-Rb multi-resource coexisting Quaternary brine deposits.Significant research efforts have been directed to the origin of K-Li resources and evolutionary history...The Qarhan Salt Lake(QSL)in western China is K-Sr-Li-B-Br-Rb multi-resource coexisting Quaternary brine deposits.Significant research efforts have been directed to the origin of K-Li resources and evolutionary history of the QSL.However,the study on the different sources,recharge processes,and differential distribution patterns for these resource elements in brine deposits is still inadequate.Therefore,we measured Li-B concentrations and H-O-Sr-B isotopic compositions of different waters(river,spring,and brine)from the QSL,combined with the reported K-Sr contents and multiple isotopes of waters,to discuss the recharge,source of K-Sr-Li-B and their spatial distributions,by analogy with other evaporite basins in the world.The results show that:(1)the K-Li-B-Sr elemental concentrations of brines and their spatial distribution in the QSL are diverse;(2)high K and Sr values are distributed in Dabuxun and Qarhan sections,respectively,which are controlled by Ca-Cl springs in the northern QSL;on the contrary,Li and B values are enriched in the Bieletan section and are charged by thermal springs in the Kunlun Mountains;(3)the formation and evolution of Ca-Cl and thermal springs constrain fundamentally on the recharge processes of K-Sr and Li-B elements in the terminal salt lakes of the Qaidam Basin(QB);(4)some analogues of recharge processes limit the resource elements of the QSL and other salt lakes(Da Qaidam,Lop Nur,Zhabuye,Atacama,and Guayatayoc)in the world provides a reference for the resource exploration in deep formation waters in the evaporite basins.展开更多
For investigating the biological function of ADPR, four novel analogues (compounds 2-5) in which the pyrophosphate linkage was replaced by the aspartic acid dipeptide were synthesized. 5'-Amino adenosine or its ana...For investigating the biological function of ADPR, four novel analogues (compounds 2-5) in which the pyrophosphate linkage was replaced by the aspartic acid dipeptide were synthesized. 5'-Amino adenosine or its analogues was used as the starting material, liquid phase peptide synthesis strategy was used to construct these ADPR analogues. The structures were characterized by 1H NMR and HRMS spectra. This study provides a versatile synthesis of peptide modified ADPR analogues and helps to understand the structure-activity relationship of ADPR.展开更多
Hepatocellular carcinoma(HCC) is a major health problem worldwide, representing one of the leading causes of death. Chronic hepatitis B virus(HBV) infection(CHB) is the most important etiologic factor of this tumor, a...Hepatocellular carcinoma(HCC) is a major health problem worldwide, representing one of the leading causes of death. Chronic hepatitis B virus(HBV) infection(CHB) is the most important etiologic factor of this tumor, accounting for the development of more than50% of the cases in the world. Primary prevention ofHCC is possible by hepatitis B vaccination conferring protection from HBV infection. However, according to the World Health Organization Hepatitis B Fact sheet N° 204(update of July 2014) globally there exists a large pool of > 240 million people chronically infected with HBV who are at risk for development of HCC. These individuals represent a target population for secondary prevention both of cirrhosis and of HCC. Since ongoing HBV replication in CHB is linked with the progression of the underlying liver disease to cirrhosis as well as with the development of HCC, effective antiviral treatment in CHB has also been evaluated in terms of secondary prevention of HCC. Currently, most patients with active CHB are subjected to long term treatment with the first line nucleos(t)ide analogues entecavir and tenofovir. These compounds are of high antiviral potency and have a high barrier to HBV resistance compared to lamivudine, adefovir dipivoxil and even telbivudine. Many studies have shown that patients under antiviral treatment, especially those in virological remission, develop less frequently HCC compared to the untreated ones. However, the risk for development of HCC cannot be eliminated. Therefore, surveillance for the development of HCC of patients with chronic hepatitis B must be lifelong or until a time in the future when new treatments will be able to completely eradicate HBV from the liver particularly in the early stages of CHB infection. In this context, the aim of this review is to outline the magnitude of the risk for development of HCC among patients with CHB, in the various phases of the infection and in relation to virus, host and environmental factors as evaluated in the world literature. Moreover, the benefits of antiviral treatment of CHB with nucleos/tide analogs, which have changed the natural history of the disease and have reduced but not eliminated the risk of HCC are also reviewed.展开更多
In the applications of large-scale energy storage,aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature.However,carrier ions always exhibit huge hyd...In the applications of large-scale energy storage,aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature.However,carrier ions always exhibit huge hydrated radius in aqueous electrolyte,which brings difficulty to find suitable host materials that can achieve highly reversible insertion and extraction of cations.Owing to open threedimensional rigid framework and facile synthesis,Prussian blue analogues(PBAs)receive the most extensive attention among various host candidates in aqueous system.Herein,a comprehensive review on recent progresses of PBAs in aqueous batteries is presented.Based on the application in different aqueous systems,the relationship between electrochemical behaviors(redox potential,capacity,cycling stability and rate performance)and structural characteristics(preparation method,structure type,particle size,morphology,crystallinity,defect,metal atom in highspin state and chemical composition)is analyzed and summarized thoroughly.It can be concluded that the required type of PBAs is different for various carrier ions.In particular,the desalination batteries worked with the same mechanism as aqueous batteries are also discussed in detail to introduce the application of PBAs in aqueous systems comprehensively.This report can help the readers to understand the relationship between physical/chemical characteristics and electrochemical properties for PBAs and find a way to fabricate high-performance PBAs in aqueous batteries and desalination batteries.展开更多
The ideal endpoint of hepatitis B virus(HBV)antiviral therapy is HBsAg loss,a difficult goal to obtain,especially in HBeAg negative patients.Herein,we report the results obtained by the addition of peg-interferonα-2a...The ideal endpoint of hepatitis B virus(HBV)antiviral therapy is HBsAg loss,a difficult goal to obtain,especially in HBeAg negative patients.Herein,we report the results obtained by the addition of peg-interferonα-2a to a long-lasting nucleos(t)ide analogues therapy in a HBeAg negative,genotype D patient with steadily HBV-DNA negative/HBsAg positive values.In 2002,our Caucasian 44-year-old male patient received lamivudine and,4 years later,added adefovir because of a virological breakthrough.In 2011,considering his young age,liver stiffness(4.3 kPa)and HBsAg levels(3533IU/mL),we added Peg-interferonα-2a for six months(3in combination with nucleos(t)ide analogues followed by 3 mo of Peg-interferonα-2a monotherapy).A decrease of HBsAg levels was observed after 1 mo(1.21log)of Peg-interferon and 3 mo(1.88 log)after the discontinuation of all drugs.Later,a complete clearance of HBsAg was obtained with steadily undetectable HBVDNA serum levels(<9 IU/mL).HBsAg clearance by the addition of a short course of Peg-interferonα-2a represents an important result with clinical and pharmacoeconomic implications,considering that nucleos(t)ide analogues therapy in HBeAg negative chronic hepatitis B patients is considered a long-lasting/life-long treatment.展开更多
Hepatitis B is a common yet serious infectious disease of the liver, affecting millions of people worldwide. Liver transplantation is the only possible treatment for those who advance to end-stage liver disease. Donor...Hepatitis B is a common yet serious infectious disease of the liver, affecting millions of people worldwide. Liver transplantation is the only possible treatment for those who advance to end-stage liver disease. Donors positive for hepatitis B virus(HBV) core antibody(HBc Ab) have previously been considered unsuitable for transplants. However, those who test negative for the more serious hepatitis B surface antigen can now be used as liver donors, thereby reducing organ shortages. Remarkable improvements have been made in the treatment against HBV, most notably with the development of nucleoside analogues(NAs), which markedly lessen cirrhosis and reduce post-transplantation HBV recurrence. However, HBV recurrence still occurs in many patients following liver transplantation due to the development of drug resistance and poor compliance with therapy. Optimized prophylactic treatment with appropriate NA usage is crucial prior to liver transplantation, and undetectable HBV DNA at the time of transplantation should be achieved. NA-based and hepatitis B immune globulin-based treatment regimens can differ between patients depending on the patients' condition, virus status, and presence of drug resistance. This review focuses on the current progress in applying NAs during the perioperative period of liver transplantation and the prophylactic strategies using NAs to prevent de novo HBV infection in recipients of HBc Ab-positive liver grafts.展开更多
Four techniques, Soxhlet extraction (SOX), ultrasonic extraction (USE), fluidized-bed extraction (FBE) and acce-lerated solvent extraction (ASE) with different solvents (methanol, hexane/acetone and acetonitrile) were...Four techniques, Soxhlet extraction (SOX), ultrasonic extraction (USE), fluidized-bed extraction (FBE) and acce-lerated solvent extraction (ASE) with different solvents (methanol, hexane/acetone and acetonitrile) were used for theextraction of DDT analogues in sediments. Results revealed that the four extraction techniques had high recoveries (>86.0%) with low standard deviations (< 12.0%) for most of DDT analogues, meaning that they could all successfully extractDDT analogues in sediments. Accelerated solvent extraction using methanol and hexane/acetone (1:1), fluidized-bedextraction using hexane/acetone (1:1) and the ultrasonic extraction using hexane/acetone (1:1) were comparable or betterthan Soxhlet extraction using hexane/acetone (1:1). Considering solvent- and time-consumption, level of automation,and environmental risk, accelerated solvent extraction with hexane/acetone (1:1) was better than the other extractiontechniques.展开更多
Peptides are one of the indispensable substances in life. The use of computer aided drug design(CADD) methods to design peptides and peptiodmimetics can short the design cycle, save research funding, improve the level...Peptides are one of the indispensable substances in life. The use of computer aided drug design(CADD) methods to design peptides and peptiodmimetics can short the design cycle, save research funding, improve the level of whole research to a large extent and guide the discovery of new drugs. In this paper, Melittin and amoebapore three-dimensional quantitative structureactivity relationship(3D-QSAR) models were established by using comparative molecular field analysis(CoMFA) and comparative molecular similarity indices analysis(CoMSIA) method. The result shows that, the correlation coefficient(q^2) was 0.583 and non-cross-validation correlation coefficient(r^2) was 0.972 for the melittin CoMFA model. The q^2 and r^2 were 0.630 and 0.995 for the best CoMSIA model, 0.645 and 0.993 for the amoebapore CoMFA model, and 0.738 and 0.996 for the best CoMSIA model. The statistical parameters demonstrated that the CoMFA and CoMSIA models had both good predictive ability and high statistical stability, and can provide theoretical basis for designing new high activity polypeptide drugs.展开更多
Five novel curcumin analogues bearing different substituents at 4-position of phenyl group were synthesized. Their structures were confirmed by NMR and HRMS spectrum. Their cytotoxic activities against six tumor cell ...Five novel curcumin analogues bearing different substituents at 4-position of phenyl group were synthesized. Their structures were confirmed by NMR and HRMS spectrum. Their cytotoxic activities against six tumor cell lines were tested by the standard MTT assay in vitro. The results indicated that four analogues (1A-1C, 1E) with solubilizing moieties showed selective potent cytotoxicity against HepG2, HeLa and CT26 cell lines, and analogue 1A and 1C exhibited more potent cytotoxicity than curcumin against CT26 cell line. It was suggested that introduction of appropriate substituents to 4-position of phenyl group might be a potential option for structural modification of curcumin.展开更多
The Two-dimensional Quantitative Structure-activity Relationship (2D-QSAR) of a series of novel norcantharidin analogues, which exhibit hnhibitory activities of protein phosphatase 1 and 2A (PP1 and PP2A), has bee...The Two-dimensional Quantitative Structure-activity Relationship (2D-QSAR) of a series of novel norcantharidin analogues, which exhibit hnhibitory activities of protein phosphatase 1 and 2A (PP1 and PP2A), has been studied with a combined method of ab initio (I/F), molecular mechanics (MM+) and statistics. The established 2D-QSAR model (Eq. 1) for PP1 shows a reasonable regressive performance (R2= 0.749), and the hydrophobic property of this molecule plays a decisive role in determining the inhibitory activity of PP1. In addition, the established 2D-QSAR model (Eq. 2) for PP2A also shows an acceptable regressive performance (R2= 0.701), and the dipole moment of the molecule determines the inhibitory activity of PP2A.展开更多
Nucleoside analogues are first line chemotherapy in various severe diseases:AIDS(acquired immunodeficiency disease syndrome),cytomegalovirus infections,cancer,etc.However,many nucleoside analogues exhibit poor oral bi...Nucleoside analogues are first line chemotherapy in various severe diseases:AIDS(acquired immunodeficiency disease syndrome),cytomegalovirus infections,cancer,etc.However,many nucleoside analogues exhibit poor oral bioavailability because of their high polarity and low intestinal permeability.In order to get around this drawback,prodrugs have been utilized to improve lipophilicity by chemical modification of the parent drug.Alternatively,prodrugs targeting transporters present in the intestine have been applied to promote the transport of the nucleoside analogues.Valacyclovir and valganciclovir are two classic valine ester prodrugs transported by oligopeptide transporter 1.The ideal prodrug achieves delivery of a parent drug by attaching a non-toxic moiety that is stable during transport,but is readily degraded to the parent drug once at the target.This article presents advances of prodrug approaches for enhancing oral absorption of nucleoside analogues.展开更多
An efficient protocol for the synthesis of N^6-(2-Hydroxyethyl)adenosine and its analogues through nucleophilic substitution was developed. All the reactions were completed in 10 rain under microwave irradiation. Us...An efficient protocol for the synthesis of N^6-(2-Hydroxyethyl)adenosine and its analogues through nucleophilic substitution was developed. All the reactions were completed in 10 rain under microwave irradiation. Using water as solvent makes our method eco-friendly and easy to handle with.展开更多
Eight novel silybin analogues (7a-h) were synthesized and their antioxidant properties including the capability of scavenging superoxide anion free radicals and the inhibitory effect on DPPH free radicals were dete...Eight novel silybin analogues (7a-h) were synthesized and their antioxidant properties including the capability of scavenging superoxide anion free radicals and the inhibitory effect on DPPH free radicals were determined. Several synthetic compounds showed comparable antioxidative effect to that of quercetin.展开更多
Nucleos(t)ide analogues(NA) are a breakthrough in the treatment and management of chronic hepatitis B.NA could suppress the replication of hepatitis B virus(HBV) and control the progression of the disease.However,drug...Nucleos(t)ide analogues(NA) are a breakthrough in the treatment and management of chronic hepatitis B.NA could suppress the replication of hepatitis B virus(HBV) and control the progression of the disease.However,drug resistance caused by their long-term use becomes a practical problem,which influences the long-term outcomes in patients.Liver transplantation is the only choice for patients with HBV-related end-stage liver disease.But,the recurrence of HBV after transplantation often caused by the development of drug resistance leads to unfavorable outcomes for the recipients.Recently,the multi-drug resistance(MDR) has become a common issue raised due to the development and clinical application of a variety of NA.This may complicate the antiviral therapy and bring poorly prognostic outcomes.Although clinical evidence has suggested that combination therapy with different NA could effectively reduce the viral load in patients with MDR,the advent of new antiviral agents with high potency and high genetic barrier to resistance brings hope to antiviral therapy.The future of HBV researches relies on how toprevent the MDR occurrence and develop reasonable and effective treatment strategies.This review focuses on the diagnostic and therapeutic progress in MDR caused by the anti-HBV NA and describes some new research progress in this field.展开更多
BACKGROUND Hepatitis B e antigen-negative chronic hepatitis B patients under nucleos(t)ids analogues(NAs)rarely achieve hepatitis B surface antigen(HBsAg)loss.AIM To evaluate if the addition of pegylated interferon(Pe...BACKGROUND Hepatitis B e antigen-negative chronic hepatitis B patients under nucleos(t)ids analogues(NAs)rarely achieve hepatitis B surface antigen(HBsAg)loss.AIM To evaluate if the addition of pegylated interferon(Peg-IFN)could decrease HBsAg and hepatitis B core-related antigen(HBcrAg)levels and increase HBsAg loss rate in patients under NAs therapy.METHODS Prospective,non-randomized,open-label trial evaluating the combination of Peg-IFN 180μg/week plus NAs during forty-eight weeks vs NAs in monotherapy.Hepatitis B e antigen-negative non-cirrhotic chronic hepatitis B patients of a tertiary hospital,under NAs therapy for at least 2 years and with undetectable viral load,were eligible.Patients with hepatitis C virus,hepatitis D virus or human immunodeficiency virus co-infection and liver transplanted patients were excluded.HBsAg and HBcrAg levels(log10 U/mL)were measured at baseline and during ninety-six weeks.HBsAg loss rate was evaluated in both groups.Adverse events were recorded in both groups.The kinetic of HBsAg for each treatment group was evaluated from baseline to weeks 24 and 48 by the slope of the HBsAg decline(log10 IU/mL/week)using a linear regression model.RESULTS Sixty-five patients were enrolled,61%receiving tenofovir and 33%entecavir.Thirty-six(55%)were included in Peg-IFN-NA group and 29(44%)in NA group.After matching by age and treatment duration,baseline HBsAg levels were comparable between groups(3.1 vs 3.2)(P=0.25).HBsAg levels at weeks 24,48 and 96 declined in Peg-IFN-NA group(-0.26,-0.40 and-0.44)and remained stable in NA group(-0.10,-0.10 and-0.10)(P<0.05).The slope of HBsAg decline in Peg-IFN-NA group(-0.02)was higher than in NA group(-0.00)(P=0.015).HBcrAg levels did not change.Eight(22%)patients discontinued Peg-IFN due to adverse events.The HBsAg loss was achieved in 3(8.3%)patients of the Peg-IFN-NA group and 0(0%)of the NA group.CONCLUSION The addition of Peg-IFN to NAs caused a greater and faster decrease of HBsAg levels compared to NA therapy.Side effects of Peg-IFN can limit its use in clinical practice.展开更多
After the geometry optimization at B3LYP/6-31+G(d,p) level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,re...After the geometry optimization at B3LYP/6-31+G(d,p) level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,respectively.The 13C NMR chemical shifts calculated at HF/6-31+G(d) level show better agreement with the observed values.By a series of linear correction equations (δpred=a + bδcalc),accurate prediction of 13C chemical shifts was achieved for the new fluorenone compound.The linear correlation of δpred with δexptl is excellent,and the square of correlation coefficient,r2,is up to 0.994.The maximum absolute difference between δpred and δexptl,Δδ,is 4.6 ppm,and the root-mean-square error between δpred and δexptl is only 2.6 ppm.展开更多
Venusian coronae are large(60-2600 km diameter)tectono-magmatic features characterized by quasi-circular graben-fissure systems and topographic features such as a central dome,central depression,circular rim or circular
基金supported by Jiangsu Innovative Group of Meat Nutrition,Health and Biotechnologythe Postgraduate Research&Practice Innovation Program of Jiangsu Province(grant number:KYCX21_0575)。
文摘To determine the effects of plant-based meat analogues on the metabolic health and the possible mechanisms,mice were fed with a real pork diet(AP),a real beef diet(AB),a plant-based pork analogue diet(PP)and plant-based beef analogue diet(PB)for 68 days.Compared with real meat,the plant-based meat analogues increased food and energy intake,body weight,white fat and liver weight and caused adipocyte hypertrophy,hepatic lipid droplet accumulation,and inflammatory responses in mice.Metabolomics revealed that plantbased meat analogues altered the composition of serum metabolites,which regulated lipid metabolism homeostasis.The PB diet upregulated gene expression related to lipid synthesis,lipolysis and adipocyte differentiation while the PP diet upregulated expression of lipolysis-related genes but downregulated expression of adipocyte differentiation-related genes in white adipose tissue.Meanwhile,both PP and PB diets upregulated lipid influx-and synthesis-related genes but downregulated lipid oxidation-related genes in liver.The specific metabolite biomarkers may affect fat accumulation mainly by direct lipid metabolism pathways or indirect amino acid metabolism,protein digestion and absorption,bile secretion,aminoacyl-tRNA biosynthesis,neuroactive ligand-receptor interaction and ABC transporters pathways.These findings provide a new insight into understanding the differences in nutritional functions of meat and plant-based meat analogues.
基金Financial support from the China Scholarship Council(201806220068,201806650009) to F.Dthe Villum Experiment(grant No.35844) to X.X.
文摘Prussian blue analogues(PBAs) with inherent ordered structures and abundant metal ion sites are widely explored as precursors for various electrochemical applications,including oxygen evolution reaction(OER).Using a range of characterization techniques including Fourier-transform infrared spectroscopy(FT-IR),X-ray photoelectron spectroscopy(XPS),X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS),this work discloses the process of replacement of K^(+)by NH4^(+)in the interstitial spaces of the CoFe PBA by a hot aqueous urea solution,which influences the transformation of PBAs under further heat treatment and the OER performance of the deriva tives.After heat treatment at 400℃ under Ar flow,high-resolution transmission electron microscopy(HRTEM) images reveal that CoFe alloy nanoparticles grew on the crystalline cubes of CoFe PBA with K^(+),while CoFe PBA cubes with NH4^(+)become amorphous.Besides,the derivative of CoFe PBA with NH4^(+)(Ar-U-CoFe PBA) performs better than the derivative of CoFe PBA with K^(+)(Ar-CoFe PBA) in OER,registering a lower overpotential of 305 mV at 10 mA cm^(-2),a smaller Tafel slope of 36.1 mV dec^(-1),and better stability over a testing course of 20 h in 1.0 M KOH.A single-cell alkaline electrolyzer,using Ar-U-CoFe PBA and Pt/C for the anodic and cathodic catalyst,respectively,requires an initial cell voltage of 1.66 V to achieve 100 mA cm^(-2)at 80℃,with negligible degradation after100 h.
基金Supported by the Second Tibetan Plateau Scientific Expedition and Research Program(No.2019 QZKK 0805)the National Natural Science Foundation of China(No.U 21 A 2018)the Foundation of Department of Qinghai Science&Technology(No.2020-ZJ-T 06)。
文摘The Qarhan Salt Lake(QSL)in western China is K-Sr-Li-B-Br-Rb multi-resource coexisting Quaternary brine deposits.Significant research efforts have been directed to the origin of K-Li resources and evolutionary history of the QSL.However,the study on the different sources,recharge processes,and differential distribution patterns for these resource elements in brine deposits is still inadequate.Therefore,we measured Li-B concentrations and H-O-Sr-B isotopic compositions of different waters(river,spring,and brine)from the QSL,combined with the reported K-Sr contents and multiple isotopes of waters,to discuss the recharge,source of K-Sr-Li-B and their spatial distributions,by analogy with other evaporite basins in the world.The results show that:(1)the K-Li-B-Sr elemental concentrations of brines and their spatial distribution in the QSL are diverse;(2)high K and Sr values are distributed in Dabuxun and Qarhan sections,respectively,which are controlled by Ca-Cl springs in the northern QSL;on the contrary,Li and B values are enriched in the Bieletan section and are charged by thermal springs in the Kunlun Mountains;(3)the formation and evolution of Ca-Cl and thermal springs constrain fundamentally on the recharge processes of K-Sr and Li-B elements in the terminal salt lakes of the Qaidam Basin(QB);(4)some analogues of recharge processes limit the resource elements of the QSL and other salt lakes(Da Qaidam,Lop Nur,Zhabuye,Atacama,and Guayatayoc)in the world provides a reference for the resource exploration in deep formation waters in the evaporite basins.
基金National Natural Science Foundation of China(Grant No.20472007)the Research Found for the DocroralProgram of Higher Education
文摘For investigating the biological function of ADPR, four novel analogues (compounds 2-5) in which the pyrophosphate linkage was replaced by the aspartic acid dipeptide were synthesized. 5'-Amino adenosine or its analogues was used as the starting material, liquid phase peptide synthesis strategy was used to construct these ADPR analogues. The structures were characterized by 1H NMR and HRMS spectra. This study provides a versatile synthesis of peptide modified ADPR analogues and helps to understand the structure-activity relationship of ADPR.
文摘Hepatocellular carcinoma(HCC) is a major health problem worldwide, representing one of the leading causes of death. Chronic hepatitis B virus(HBV) infection(CHB) is the most important etiologic factor of this tumor, accounting for the development of more than50% of the cases in the world. Primary prevention ofHCC is possible by hepatitis B vaccination conferring protection from HBV infection. However, according to the World Health Organization Hepatitis B Fact sheet N° 204(update of July 2014) globally there exists a large pool of > 240 million people chronically infected with HBV who are at risk for development of HCC. These individuals represent a target population for secondary prevention both of cirrhosis and of HCC. Since ongoing HBV replication in CHB is linked with the progression of the underlying liver disease to cirrhosis as well as with the development of HCC, effective antiviral treatment in CHB has also been evaluated in terms of secondary prevention of HCC. Currently, most patients with active CHB are subjected to long term treatment with the first line nucleos(t)ide analogues entecavir and tenofovir. These compounds are of high antiviral potency and have a high barrier to HBV resistance compared to lamivudine, adefovir dipivoxil and even telbivudine. Many studies have shown that patients under antiviral treatment, especially those in virological remission, develop less frequently HCC compared to the untreated ones. However, the risk for development of HCC cannot be eliminated. Therefore, surveillance for the development of HCC of patients with chronic hepatitis B must be lifelong or until a time in the future when new treatments will be able to completely eradicate HBV from the liver particularly in the early stages of CHB infection. In this context, the aim of this review is to outline the magnitude of the risk for development of HCC among patients with CHB, in the various phases of the infection and in relation to virus, host and environmental factors as evaluated in the world literature. Moreover, the benefits of antiviral treatment of CHB with nucleos/tide analogs, which have changed the natural history of the disease and have reduced but not eliminated the risk of HCC are also reviewed.
基金This work was sponsored by NSAF Joint Fund(U1830106)Science and Technology Innovation 2025 Major Program of Ningbo(2018B10061)K.C.Wong Magna Fund in Ningbo University.
文摘In the applications of large-scale energy storage,aqueous batteries are considered as rivals for organic batteries due to their environmentally friendly and low-cost nature.However,carrier ions always exhibit huge hydrated radius in aqueous electrolyte,which brings difficulty to find suitable host materials that can achieve highly reversible insertion and extraction of cations.Owing to open threedimensional rigid framework and facile synthesis,Prussian blue analogues(PBAs)receive the most extensive attention among various host candidates in aqueous system.Herein,a comprehensive review on recent progresses of PBAs in aqueous batteries is presented.Based on the application in different aqueous systems,the relationship between electrochemical behaviors(redox potential,capacity,cycling stability and rate performance)and structural characteristics(preparation method,structure type,particle size,morphology,crystallinity,defect,metal atom in highspin state and chemical composition)is analyzed and summarized thoroughly.It can be concluded that the required type of PBAs is different for various carrier ions.In particular,the desalination batteries worked with the same mechanism as aqueous batteries are also discussed in detail to introduce the application of PBAs in aqueous systems comprehensively.This report can help the readers to understand the relationship between physical/chemical characteristics and electrochemical properties for PBAs and find a way to fabricate high-performance PBAs in aqueous batteries and desalination batteries.
文摘The ideal endpoint of hepatitis B virus(HBV)antiviral therapy is HBsAg loss,a difficult goal to obtain,especially in HBeAg negative patients.Herein,we report the results obtained by the addition of peg-interferonα-2a to a long-lasting nucleos(t)ide analogues therapy in a HBeAg negative,genotype D patient with steadily HBV-DNA negative/HBsAg positive values.In 2002,our Caucasian 44-year-old male patient received lamivudine and,4 years later,added adefovir because of a virological breakthrough.In 2011,considering his young age,liver stiffness(4.3 kPa)and HBsAg levels(3533IU/mL),we added Peg-interferonα-2a for six months(3in combination with nucleos(t)ide analogues followed by 3 mo of Peg-interferonα-2a monotherapy).A decrease of HBsAg levels was observed after 1 mo(1.21log)of Peg-interferon and 3 mo(1.88 log)after the discontinuation of all drugs.Later,a complete clearance of HBsAg was obtained with steadily undetectable HBVDNA serum levels(<9 IU/mL).HBsAg clearance by the addition of a short course of Peg-interferonα-2a represents an important result with clinical and pharmacoeconomic implications,considering that nucleos(t)ide analogues therapy in HBeAg negative chronic hepatitis B patients is considered a long-lasting/life-long treatment.
基金Supported by National High Technology Research and Development Program(863 Program)of China,Grant No.2012AA021001
文摘Hepatitis B is a common yet serious infectious disease of the liver, affecting millions of people worldwide. Liver transplantation is the only possible treatment for those who advance to end-stage liver disease. Donors positive for hepatitis B virus(HBV) core antibody(HBc Ab) have previously been considered unsuitable for transplants. However, those who test negative for the more serious hepatitis B surface antigen can now be used as liver donors, thereby reducing organ shortages. Remarkable improvements have been made in the treatment against HBV, most notably with the development of nucleoside analogues(NAs), which markedly lessen cirrhosis and reduce post-transplantation HBV recurrence. However, HBV recurrence still occurs in many patients following liver transplantation due to the development of drug resistance and poor compliance with therapy. Optimized prophylactic treatment with appropriate NA usage is crucial prior to liver transplantation, and undetectable HBV DNA at the time of transplantation should be achieved. NA-based and hepatitis B immune globulin-based treatment regimens can differ between patients depending on the patients' condition, virus status, and presence of drug resistance. This review focuses on the current progress in applying NAs during the perioperative period of liver transplantation and the prophylactic strategies using NAs to prevent de novo HBV infection in recipients of HBc Ab-positive liver grafts.
基金the Outstanding Youth Fund of the National Natural Science Foundation of China (No. 40325001),the National Key Basic Research and Development Program of China (No. 2002CB410805) and the Ocean University ofChina.
文摘Four techniques, Soxhlet extraction (SOX), ultrasonic extraction (USE), fluidized-bed extraction (FBE) and acce-lerated solvent extraction (ASE) with different solvents (methanol, hexane/acetone and acetonitrile) were used for theextraction of DDT analogues in sediments. Results revealed that the four extraction techniques had high recoveries (>86.0%) with low standard deviations (< 12.0%) for most of DDT analogues, meaning that they could all successfully extractDDT analogues in sediments. Accelerated solvent extraction using methanol and hexane/acetone (1:1), fluidized-bedextraction using hexane/acetone (1:1) and the ultrasonic extraction using hexane/acetone (1:1) were comparable or betterthan Soxhlet extraction using hexane/acetone (1:1). Considering solvent- and time-consumption, level of automation,and environmental risk, accelerated solvent extraction with hexane/acetone (1:1) was better than the other extractiontechniques.
基金Supported by the National Natural Science Foundation of China(21475081)Natural Science Foundation of Shaanxi Province of China(2015JM2057)Graduate Innovation Fund of Shaanxi University of Science and Technology
文摘Peptides are one of the indispensable substances in life. The use of computer aided drug design(CADD) methods to design peptides and peptiodmimetics can short the design cycle, save research funding, improve the level of whole research to a large extent and guide the discovery of new drugs. In this paper, Melittin and amoebapore three-dimensional quantitative structureactivity relationship(3D-QSAR) models were established by using comparative molecular field analysis(CoMFA) and comparative molecular similarity indices analysis(CoMSIA) method. The result shows that, the correlation coefficient(q^2) was 0.583 and non-cross-validation correlation coefficient(r^2) was 0.972 for the melittin CoMFA model. The q^2 and r^2 were 0.630 and 0.995 for the best CoMSIA model, 0.645 and 0.993 for the amoebapore CoMFA model, and 0.738 and 0.996 for the best CoMSIA model. The statistical parameters demonstrated that the CoMFA and CoMSIA models had both good predictive ability and high statistical stability, and can provide theoretical basis for designing new high activity polypeptide drugs.
文摘Five novel curcumin analogues bearing different substituents at 4-position of phenyl group were synthesized. Their structures were confirmed by NMR and HRMS spectrum. Their cytotoxic activities against six tumor cell lines were tested by the standard MTT assay in vitro. The results indicated that four analogues (1A-1C, 1E) with solubilizing moieties showed selective potent cytotoxicity against HepG2, HeLa and CT26 cell lines, and analogue 1A and 1C exhibited more potent cytotoxicity than curcumin against CT26 cell line. It was suggested that introduction of appropriate substituents to 4-position of phenyl group might be a potential option for structural modification of curcumin.
基金supported by the China Scholarship Council (CSC [2006] No. 3085)
文摘The Two-dimensional Quantitative Structure-activity Relationship (2D-QSAR) of a series of novel norcantharidin analogues, which exhibit hnhibitory activities of protein phosphatase 1 and 2A (PP1 and PP2A), has been studied with a combined method of ab initio (I/F), molecular mechanics (MM+) and statistics. The established 2D-QSAR model (Eq. 1) for PP1 shows a reasonable regressive performance (R2= 0.749), and the hydrophobic property of this molecule plays a decisive role in determining the inhibitory activity of PP1. In addition, the established 2D-QSAR model (Eq. 2) for PP2A also shows an acceptable regressive performance (R2= 0.701), and the dipole moment of the molecule determines the inhibitory activity of PP2A.
基金the Project for Sci-ence and Technology Plan of Liaoning Province(No.2011225020).
文摘Nucleoside analogues are first line chemotherapy in various severe diseases:AIDS(acquired immunodeficiency disease syndrome),cytomegalovirus infections,cancer,etc.However,many nucleoside analogues exhibit poor oral bioavailability because of their high polarity and low intestinal permeability.In order to get around this drawback,prodrugs have been utilized to improve lipophilicity by chemical modification of the parent drug.Alternatively,prodrugs targeting transporters present in the intestine have been applied to promote the transport of the nucleoside analogues.Valacyclovir and valganciclovir are two classic valine ester prodrugs transported by oligopeptide transporter 1.The ideal prodrug achieves delivery of a parent drug by attaching a non-toxic moiety that is stable during transport,but is readily degraded to the parent drug once at the target.This article presents advances of prodrug approaches for enhancing oral absorption of nucleoside analogues.
基金the National Natural Science Foundation of China(No.20372018)
文摘An efficient protocol for the synthesis of N^6-(2-Hydroxyethyl)adenosine and its analogues through nucleophilic substitution was developed. All the reactions were completed in 10 rain under microwave irradiation. Using water as solvent makes our method eco-friendly and easy to handle with.
文摘Eight novel silybin analogues (7a-h) were synthesized and their antioxidant properties including the capability of scavenging superoxide anion free radicals and the inhibitory effect on DPPH free radicals were determined. Several synthetic compounds showed comparable antioxidative effect to that of quercetin.
文摘Nucleos(t)ide analogues(NA) are a breakthrough in the treatment and management of chronic hepatitis B.NA could suppress the replication of hepatitis B virus(HBV) and control the progression of the disease.However,drug resistance caused by their long-term use becomes a practical problem,which influences the long-term outcomes in patients.Liver transplantation is the only choice for patients with HBV-related end-stage liver disease.But,the recurrence of HBV after transplantation often caused by the development of drug resistance leads to unfavorable outcomes for the recipients.Recently,the multi-drug resistance(MDR) has become a common issue raised due to the development and clinical application of a variety of NA.This may complicate the antiviral therapy and bring poorly prognostic outcomes.Although clinical evidence has suggested that combination therapy with different NA could effectively reduce the viral load in patients with MDR,the advent of new antiviral agents with high potency and high genetic barrier to resistance brings hope to antiviral therapy.The future of HBV researches relies on how toprevent the MDR occurrence and develop reasonable and effective treatment strategies.This review focuses on the diagnostic and therapeutic progress in MDR caused by the anti-HBV NA and describes some new research progress in this field.
文摘BACKGROUND Hepatitis B e antigen-negative chronic hepatitis B patients under nucleos(t)ids analogues(NAs)rarely achieve hepatitis B surface antigen(HBsAg)loss.AIM To evaluate if the addition of pegylated interferon(Peg-IFN)could decrease HBsAg and hepatitis B core-related antigen(HBcrAg)levels and increase HBsAg loss rate in patients under NAs therapy.METHODS Prospective,non-randomized,open-label trial evaluating the combination of Peg-IFN 180μg/week plus NAs during forty-eight weeks vs NAs in monotherapy.Hepatitis B e antigen-negative non-cirrhotic chronic hepatitis B patients of a tertiary hospital,under NAs therapy for at least 2 years and with undetectable viral load,were eligible.Patients with hepatitis C virus,hepatitis D virus or human immunodeficiency virus co-infection and liver transplanted patients were excluded.HBsAg and HBcrAg levels(log10 U/mL)were measured at baseline and during ninety-six weeks.HBsAg loss rate was evaluated in both groups.Adverse events were recorded in both groups.The kinetic of HBsAg for each treatment group was evaluated from baseline to weeks 24 and 48 by the slope of the HBsAg decline(log10 IU/mL/week)using a linear regression model.RESULTS Sixty-five patients were enrolled,61%receiving tenofovir and 33%entecavir.Thirty-six(55%)were included in Peg-IFN-NA group and 29(44%)in NA group.After matching by age and treatment duration,baseline HBsAg levels were comparable between groups(3.1 vs 3.2)(P=0.25).HBsAg levels at weeks 24,48 and 96 declined in Peg-IFN-NA group(-0.26,-0.40 and-0.44)and remained stable in NA group(-0.10,-0.10 and-0.10)(P<0.05).The slope of HBsAg decline in Peg-IFN-NA group(-0.02)was higher than in NA group(-0.00)(P=0.015).HBcrAg levels did not change.Eight(22%)patients discontinued Peg-IFN due to adverse events.The HBsAg loss was achieved in 3(8.3%)patients of the Peg-IFN-NA group and 0(0%)of the NA group.CONCLUSION The addition of Peg-IFN to NAs caused a greater and faster decrease of HBsAg levels compared to NA therapy.Side effects of Peg-IFN can limit its use in clinical practice.
文摘After the geometry optimization at B3LYP/6-31+G(d,p) level,the NMR calcula-tions of a series of fluorenone analogues have been carried out by GIAO method at HF/6-31+G(d) level and B3LYP/6-311G+(2d,p) level,respectively.The 13C NMR chemical shifts calculated at HF/6-31+G(d) level show better agreement with the observed values.By a series of linear correction equations (δpred=a + bδcalc),accurate prediction of 13C chemical shifts was achieved for the new fluorenone compound.The linear correlation of δpred with δexptl is excellent,and the square of correlation coefficient,r2,is up to 0.994.The maximum absolute difference between δpred and δexptl,Δδ,is 4.6 ppm,and the root-mean-square error between δpred and δexptl is only 2.6 ppm.
文摘Venusian coronae are large(60-2600 km diameter)tectono-magmatic features characterized by quasi-circular graben-fissure systems and topographic features such as a central dome,central depression,circular rim or circular