Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethy...Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1].展开更多
ⅢThe superior adaptability of Prussian blue analogues(PBAs)in interacting with potassium ions has shifted research focus toward their potential application as cathodes of potassium-ion batteries(PIBs).The large inter...ⅢThe superior adaptability of Prussian blue analogues(PBAs)in interacting with potassium ions has shifted research focus toward their potential application as cathodes of potassium-ion batteries(PIBs).The large interstitial space formed between metal ions and–C≡N–in PBAs can accommodate large-radius K^(+).However,the rapid nucleation in the co-precipitation synthesis process of PBAs induces many lattice defects of[M(CN)_(6)]^(4-)vacancies(V_([M–C≡N])),interstitial and coordinated H_(2)O molecules,which will directly lead to performance degradation.Moreover,originating from various transition metal elements in low/high-spin electron configuration states,PBAs exhibit diverse electrochemical behaviors,such as low reaction kinetics of low-spin iron(Ⅱ),Jahn-Teller distortion and dissolution of manganese(Ⅲ),and electrochemical inertness of nickel(Ⅱ)and copper(Ⅱ).Here,we summarize recently reported structures and properties of PBAs,classifying them based on the types of transition metals(iron,cobalt,manganese,copper,nickel)employed.Advanced synthesis strategies,including control engineering of crystallinity based on H_(2)O molecules and V_([M–C≡N]),were discussed.Also,the approaches for enhancing the electrochemical performance of PBAs were highlighted.Finally,the challenges and prospects towards the future development of PBAs are put forward.The review is expected to provide technical and theoretical support for the design of high-performance PBAs.展开更多
Transition metal oxides(TMOs)have received extensive attention for their unique physical and chemical properties.It is worth noting that Fe-based materials stand out because of their rich natural resources,low toxicit...Transition metal oxides(TMOs)have received extensive attention for their unique physical and chemical properties.It is worth noting that Fe-based materials stand out because of their rich natural resources,low toxicity,low price and other advantages,but at the same time confront with critical challenges such as capacity attenuation and volume expansion.Here,a universal synthesis method of MO/MFe_(2)O_(4)(M=Ni,Cu,Zn)nanomaterials derived from Prussian blue analogues(PBAs)is proposed based on the self-sacrificing template strategy of metal-organic frameworks(MOFs).The calcined products retain the porous structure and small particle size of PBAs,which shorten the ion transport path,provide abundant electroactive sites and void space,effectively alleviate the effect of volume expansion,and improve the reaction kinetics.These MO/MFe_(2)O_(4)anode materials exhibit excellent cyclic reversibility and stability during repeated charge/discharge process,among which,NiO/NiFe_(2)O_(4) shows the best electrochemical performance,retaining a superior specific capacity of 1301.7 mAh g^(-1) following 230 cycles at 0.1 A g^(-1).In addition,the lithium adsorption capacity of the materials was further explored through the calculation of density functional theory(DFT).The research perspectives and strategies reported in this paper have strong universality and offer innovative insights for the synthesis of alternative advanced materials.展开更多
To explore high-performance cathode materials for aqueous ammonium ion batteries(AAIBs),vanadium-based Prussian blue analogue composites(VFe-PBAs)were prepared by hydrothermal coprecipitation method to enhance the rev...To explore high-performance cathode materials for aqueous ammonium ion batteries(AAIBs),vanadium-based Prussian blue analogue composites(VFe-PBAs)were prepared by hydrothermal coprecipitation method to enhance the reversible storage of NH_(4)^(+).Benefiting from the stable three-dimensional structure and spacious gap position,VFe-PBAs-2 cathode displays excellent electrochemical activity and rate performance,achieving a high specific capacity of 84.3 mA·h/g at a current density of 1000 mA/g.In addition,VFe-PBAs-2 cathode also shows impressive long-term cycle durability with 85.2% capacity retention after 3×10^(4) cycles at 5000 mA/g.The synthesized cathode materials combined with the high electrochemical activity of vanadium ions significantly promote the rapid transfer of NH_(4)^(+).Furthermore,NH_(4)^(+)embedding/extraction mechanism of VFe-PBAs-2 cathode was revealed by electrochemical kinetics tests and advanced ex-situ characterizations.The experimental results demonstrate that vanadium-modified VFe-PBAs-2 as a cathode material can remarkably improve the capacity,electrochemical activity and cycling stability of AAIBs to achieve high performance NH_(4)^(+)storage.展开更多
Prussian blue analogues(PBAs)have emerged as highly promising cathode materials for sodium-ion batteries(SIBs)due to their simple synthesis,low cost,structural tunability,and high theoretical capacity.However,despite ...Prussian blue analogues(PBAs)have emerged as highly promising cathode materials for sodium-ion batteries(SIBs)due to their simple synthesis,low cost,structural tunability,and high theoretical capacity.However,despite their significant potential,practical applications of PBAs still face multiple performance limitations.This review provides a comprehensive examination of PBAs structures and their electrochemical reaction mechanisms,and systematically summarizes current synthesis methods and modification strategies,while offering forward-looking insights.Furthermore,from the perspective of industrialization,this review systematically analyzes the synthesis,modification,and core challenges of PBAs by comparatively evaluating the feasibility of different technological pathways based on multiple dimensions,including cost-effectiveness,process scalability,environmental impact,and supply chain security,with the aim of providing forward-looking guidance for bridging the critical gap from lab to market.展开更多
Temperate woodland vegetation is initially determined by spatiotemporal and historical factors,mediated by complex biotic interactions.However,catastrophic events such as disease outbreaks(e.g.,sweet chestnut blight,a...Temperate woodland vegetation is initially determined by spatiotemporal and historical factors,mediated by complex biotic interactions.However,catastrophic events such as disease outbreaks(e.g.,sweet chestnut blight,ash dieback),infestations of insect pests,and human-accelerated climate change can create canopy gaps due to systematic decline in,or loss of,tree species that was once an important part of the canopy.Resultant cascade effects have the potential to alter the composition of woodland ecosystems quickly and radically,but inherent lag times make primary research into these effects challenging.Here,we explore change in woodland vegetation at 10 sites in response to canopy opening using the Elm Decline,a rapid loss of Ulmus in woodlands across northwestern Europe~5800 years ago that coexisted alongside other stressors such as increasing human activity,as a palaeoecological analogue.For arboreal taxa,community evenness significantly decreased,within-site turnover significantly increased,and richness remained unchanged.Changes in arboreal taxa were highly site-specific but there was a substantial decline in woody climbing taxa,especially Hedera(ivy),across the majority of sites.For shrub taxa,richness significantly increased but evenness and turnover remained consistent.Interestingly,however,there was a significant increase in abundance of shrubs at 70%of sites,including Calluna(heather),Ilex(holly)and Corylus(hazel),suggesting structural change.Surprisingly,there was no change in richness,evenness or turnover for herb taxa,possibly because change was highly variable spatially.However,there was a marked uptick in the disturbance indicator Plantago(plantain).Overall,these findings suggest that woodlands with sustained reduction in,or loss of,a tree species that once formed an important part of the canopy has profound,but often spatially idiosyncratic,impacts on vegetation diversity(richness),composition(evenness),stability(turnover),and on abundance of specific taxa,especially within the shrub layer.Use of this palaeoecological analogue,which was itself complicated by cooccurring changes in human activity,provides a valuable empirical insight into possible cascade effects of similar change in canopy opening in contemporary settings,including Ash Dieback.展开更多
Prussian blue/Prussian blue analogues(PB/PBAs)are widely used in electrochemistry and materials science fields,such as electrochemical energy storage,catalysis,water purification,and electromagnetic wave absorption,ow...Prussian blue/Prussian blue analogues(PB/PBAs)are widely used in electrochemistry and materials science fields,such as electrochemical energy storage,catalysis,water purification,and electromagnetic wave absorption,owing to their 3D open-framework structure,tunable composition,and large specific surface area.However,the co-precipitation method,which is most suitable for large-scale production of PB/PBAs,often leads to the formation of numerous crystal defects and severe lattice distortion,which significantly affects the structural stability of PB/PBAs.To obtain high-crystallinity PB/PBAs with targeted properties,precise synthesis considering various detailed conditions is especially needed.Herein,this review comprehensively summarizes the fundamental structure composition,key factors in synthesis,and applications in the electrochemistry of PB/PBAs.Unlike previous reports,this review elucidates the relationship between the physicochemical properties of PB/PBAs and their structural composition,with a particular focus on revealing the mechanisms and significance of specific preparation methods during the synthesis process,including reactant concentration,chelating agent,aging,atmosphere,temperature,and drying conditions,for achieving the precise fabrication of PB/PBAs nanomaterials.As PB/PBAs gradually become materials for multidimensional applications,we urge greater attention to the unique properties of PB/PBAs that are sustained by high crystallinity and stable crystal structures.This will effectively ensure the maximization of their advantages in practical applications.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
Berberine, an isoquinoline alkaloid component of Rhizoma Coptidis has been demonstrated to be the key active ingredient involved in its protective effect against cerebral ischemia-reperfusion. However, the comparison ...Berberine, an isoquinoline alkaloid component of Rhizoma Coptidis has been demonstrated to be the key active ingredient involved in its protective effect against cerebral ischemia-reperfusion. However, the comparison among the analogues to the protective effect against oxygen and glucose deprivation/reoxygenation （OGD-R） was mediated by inhibition of cyclooxygenase-2 （COX-2） has never been reported. The aim of this study is to investigate the protective effect of berberine and its five analogues against OGD-R in PC 12 cells, as well as to determine whether the protective effect was regulated through COX-2. An established in vitro OGD-R model of PC12 cells by oxygen glucose deprivation of 4 h and reperfusion of 24 h was used in our study. After cells were treated with berberine or its five analogues, we examined the cell viability assay by 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （MTT） assay. Cells were also collected to determine the levels of mRNA and protein of COX-2 by real time PCR and Western blot. We found that berberine and its analogues improved the viability of PC12 cells against OGD-R. Whereas berberine and berberrubine presented stronger activity with the most effective dose of 0.31 lag/mL and the minimum effective doses of 0.02 and 0.04 gg/mL. Palmatine possessed potentially weaker protective effect. The mRNA level of COX-2 in cells treated with berberine, coptisine and epiberberine was decreased significantly. The protein level of COX-2 was significantly down-regulated in cells treated with berberine. Studies suggested the important role of methylenedioxy groups （R2 and R3） of berberine analogues in COX-2 inhibitory effect, and methylenedioxy groups （R2, R3, R9 and R10） in berberine analogues in binding affinity with COX-2. Substituted hydroxyl group at R9 did not affect the activity of berberine. In summary, our study illustrated the protective effects of berberine and its analogues in PCI2 cells against OGD-R and to elucidate the structure-activity relationships. Docking analysis indicates that methylenedioxys at R2 and R3 is involved in the effect. More studies in other cells are needed to confirm our results.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
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
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
基金supported by National Natural Science Foundation of China(22361031,22308260).
文摘Volatile aromatic aldehydes,including benzaldehyde(BzH),4-fluorobenzaldehyde(4-F-BzH),4-isobutylbenzaldehyde(4-iBu-BzH),3-trifluoromethylbenzaldehyde(3-CF_(3)-BzH),p-methoxybenzaldehyde(4-MeO-BzH),and o-trifluoromethylbenzaldehyde(2-CF_(3)-BzH),are crucial raw materials for the synthesis of various pesticides and pharmaceuticals[1].
基金financially supported by research grants from Innovative Research Group Project of National Natural Science Foundation of China(No.52021004)National Key Research and Development Program of China(2022YFB3803300)+2 种基金National Natural Science Foundation of China(62474026 and 62074022)Natural Science Foundation of Chongqing(CSTB2024NSCQ-MSX1215,cstc2021jcyj-jqX0015 and CSTB2022NSCQ-MSX1183)the Youth Talent Support Program of Chongqing(CQYC2021059206).
文摘ⅢThe superior adaptability of Prussian blue analogues(PBAs)in interacting with potassium ions has shifted research focus toward their potential application as cathodes of potassium-ion batteries(PIBs).The large interstitial space formed between metal ions and–C≡N–in PBAs can accommodate large-radius K^(+).However,the rapid nucleation in the co-precipitation synthesis process of PBAs induces many lattice defects of[M(CN)_(6)]^(4-)vacancies(V_([M–C≡N])),interstitial and coordinated H_(2)O molecules,which will directly lead to performance degradation.Moreover,originating from various transition metal elements in low/high-spin electron configuration states,PBAs exhibit diverse electrochemical behaviors,such as low reaction kinetics of low-spin iron(Ⅱ),Jahn-Teller distortion and dissolution of manganese(Ⅲ),and electrochemical inertness of nickel(Ⅱ)and copper(Ⅱ).Here,we summarize recently reported structures and properties of PBAs,classifying them based on the types of transition metals(iron,cobalt,manganese,copper,nickel)employed.Advanced synthesis strategies,including control engineering of crystallinity based on H_(2)O molecules and V_([M–C≡N]),were discussed.Also,the approaches for enhancing the electrochemical performance of PBAs were highlighted.Finally,the challenges and prospects towards the future development of PBAs are put forward.The review is expected to provide technical and theoretical support for the design of high-performance PBAs.
文摘Transition metal oxides(TMOs)have received extensive attention for their unique physical and chemical properties.It is worth noting that Fe-based materials stand out because of their rich natural resources,low toxicity,low price and other advantages,but at the same time confront with critical challenges such as capacity attenuation and volume expansion.Here,a universal synthesis method of MO/MFe_(2)O_(4)(M=Ni,Cu,Zn)nanomaterials derived from Prussian blue analogues(PBAs)is proposed based on the self-sacrificing template strategy of metal-organic frameworks(MOFs).The calcined products retain the porous structure and small particle size of PBAs,which shorten the ion transport path,provide abundant electroactive sites and void space,effectively alleviate the effect of volume expansion,and improve the reaction kinetics.These MO/MFe_(2)O_(4)anode materials exhibit excellent cyclic reversibility and stability during repeated charge/discharge process,among which,NiO/NiFe_(2)O_(4) shows the best electrochemical performance,retaining a superior specific capacity of 1301.7 mAh g^(-1) following 230 cycles at 0.1 A g^(-1).In addition,the lithium adsorption capacity of the materials was further explored through the calculation of density functional theory(DFT).The research perspectives and strategies reported in this paper have strong universality and offer innovative insights for the synthesis of alternative advanced materials.
基金supported by the National Natural Science Foundation of China(No.52374301)the Hebei Provincial Natural Science Foundation,China(No.E2024501010)+2 种基金the Shijiazhuang Basic Research Project,China(No.241790667A)the Fundamental Research Funds for the Central Universities,China(No.N2423054)the Performance Subsidy Fund for Key Laboratory of Dielectric and Electrolyte Functional Material of Hebei Province,China(No.22567627H).
文摘To explore high-performance cathode materials for aqueous ammonium ion batteries(AAIBs),vanadium-based Prussian blue analogue composites(VFe-PBAs)were prepared by hydrothermal coprecipitation method to enhance the reversible storage of NH_(4)^(+).Benefiting from the stable three-dimensional structure and spacious gap position,VFe-PBAs-2 cathode displays excellent electrochemical activity and rate performance,achieving a high specific capacity of 84.3 mA·h/g at a current density of 1000 mA/g.In addition,VFe-PBAs-2 cathode also shows impressive long-term cycle durability with 85.2% capacity retention after 3×10^(4) cycles at 5000 mA/g.The synthesized cathode materials combined with the high electrochemical activity of vanadium ions significantly promote the rapid transfer of NH_(4)^(+).Furthermore,NH_(4)^(+)embedding/extraction mechanism of VFe-PBAs-2 cathode was revealed by electrochemical kinetics tests and advanced ex-situ characterizations.The experimental results demonstrate that vanadium-modified VFe-PBAs-2 as a cathode material can remarkably improve the capacity,electrochemical activity and cycling stability of AAIBs to achieve high performance NH_(4)^(+)storage.
基金supported by the National Natural Science Foundation of China(NSFC)(No.52301257,62475003)the Beijing Natural Science Foundation(No.2252031)。
文摘Prussian blue analogues(PBAs)have emerged as highly promising cathode materials for sodium-ion batteries(SIBs)due to their simple synthesis,low cost,structural tunability,and high theoretical capacity.However,despite their significant potential,practical applications of PBAs still face multiple performance limitations.This review provides a comprehensive examination of PBAs structures and their electrochemical reaction mechanisms,and systematically summarizes current synthesis methods and modification strategies,while offering forward-looking insights.Furthermore,from the perspective of industrialization,this review systematically analyzes the synthesis,modification,and core challenges of PBAs by comparatively evaluating the feasibility of different technological pathways based on multiple dimensions,including cost-effectiveness,process scalability,environmental impact,and supply chain security,with the aim of providing forward-looking guidance for bridging the critical gap from lab to market.
文摘Temperate woodland vegetation is initially determined by spatiotemporal and historical factors,mediated by complex biotic interactions.However,catastrophic events such as disease outbreaks(e.g.,sweet chestnut blight,ash dieback),infestations of insect pests,and human-accelerated climate change can create canopy gaps due to systematic decline in,or loss of,tree species that was once an important part of the canopy.Resultant cascade effects have the potential to alter the composition of woodland ecosystems quickly and radically,but inherent lag times make primary research into these effects challenging.Here,we explore change in woodland vegetation at 10 sites in response to canopy opening using the Elm Decline,a rapid loss of Ulmus in woodlands across northwestern Europe~5800 years ago that coexisted alongside other stressors such as increasing human activity,as a palaeoecological analogue.For arboreal taxa,community evenness significantly decreased,within-site turnover significantly increased,and richness remained unchanged.Changes in arboreal taxa were highly site-specific but there was a substantial decline in woody climbing taxa,especially Hedera(ivy),across the majority of sites.For shrub taxa,richness significantly increased but evenness and turnover remained consistent.Interestingly,however,there was a significant increase in abundance of shrubs at 70%of sites,including Calluna(heather),Ilex(holly)and Corylus(hazel),suggesting structural change.Surprisingly,there was no change in richness,evenness or turnover for herb taxa,possibly because change was highly variable spatially.However,there was a marked uptick in the disturbance indicator Plantago(plantain).Overall,these findings suggest that woodlands with sustained reduction in,or loss of,a tree species that once formed an important part of the canopy has profound,but often spatially idiosyncratic,impacts on vegetation diversity(richness),composition(evenness),stability(turnover),and on abundance of specific taxa,especially within the shrub layer.Use of this palaeoecological analogue,which was itself complicated by cooccurring changes in human activity,provides a valuable empirical insight into possible cascade effects of similar change in canopy opening in contemporary settings,including Ash Dieback.
基金financial support from the National Natural Science Foundation of China(NSFC,Grant No.52202253,52372193,and 22293041)Natural Science Foundation of Jiangsu Province(Grant No.BK20220914)Large Instrument and Equipment Sharing Fund of Nanjing University of Aeronautics and Astronautics。
文摘Prussian blue/Prussian blue analogues(PB/PBAs)are widely used in electrochemistry and materials science fields,such as electrochemical energy storage,catalysis,water purification,and electromagnetic wave absorption,owing to their 3D open-framework structure,tunable composition,and large specific surface area.However,the co-precipitation method,which is most suitable for large-scale production of PB/PBAs,often leads to the formation of numerous crystal defects and severe lattice distortion,which significantly affects the structural stability of PB/PBAs.To obtain high-crystallinity PB/PBAs with targeted properties,precise synthesis considering various detailed conditions is especially needed.Herein,this review comprehensively summarizes the fundamental structure composition,key factors in synthesis,and applications in the electrochemistry of PB/PBAs.Unlike previous reports,this review elucidates the relationship between the physicochemical properties of PB/PBAs and their structural composition,with a particular focus on revealing the mechanisms and significance of specific preparation methods during the synthesis process,including reactant concentration,chelating agent,aging,atmosphere,temperature,and drying conditions,for achieving the precise fabrication of PB/PBAs nanomaterials.As PB/PBAs gradually become materials for multidimensional applications,we urge greater attention to the unique properties of PB/PBAs that are sustained by high crystallinity and stable crystal structures.This will effectively ensure the maximization of their advantages in practical applications.
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.
基金National Natural Science Foundation of China(Grant No.81374006,81073092 and 90713043)the National S&T Major Special Project for New Drug R&D Program of China(Grant No.2012ZX09103-201-041,2012ZX09102-201-008 and 2011ZX09101-002-11)
文摘Berberine, an isoquinoline alkaloid component of Rhizoma Coptidis has been demonstrated to be the key active ingredient involved in its protective effect against cerebral ischemia-reperfusion. However, the comparison among the analogues to the protective effect against oxygen and glucose deprivation/reoxygenation （OGD-R） was mediated by inhibition of cyclooxygenase-2 （COX-2） has never been reported. The aim of this study is to investigate the protective effect of berberine and its five analogues against OGD-R in PC 12 cells, as well as to determine whether the protective effect was regulated through COX-2. An established in vitro OGD-R model of PC12 cells by oxygen glucose deprivation of 4 h and reperfusion of 24 h was used in our study. After cells were treated with berberine or its five analogues, we examined the cell viability assay by 3-（4,5-dimethylthiazol-2-yl）-2,5- diphenyltetrazolium bromide （MTT） assay. Cells were also collected to determine the levels of mRNA and protein of COX-2 by real time PCR and Western blot. We found that berberine and its analogues improved the viability of PC12 cells against OGD-R. Whereas berberine and berberrubine presented stronger activity with the most effective dose of 0.31 lag/mL and the minimum effective doses of 0.02 and 0.04 gg/mL. Palmatine possessed potentially weaker protective effect. The mRNA level of COX-2 in cells treated with berberine, coptisine and epiberberine was decreased significantly. The protein level of COX-2 was significantly down-regulated in cells treated with berberine. Studies suggested the important role of methylenedioxy groups （R2 and R3） of berberine analogues in COX-2 inhibitory effect, and methylenedioxy groups （R2, R3, R9 and R10） in berberine analogues in binding affinity with COX-2. Substituted hydroxyl group at R9 did not affect the activity of berberine. In summary, our study illustrated the protective effects of berberine and its analogues in PCI2 cells against OGD-R and to elucidate the structure-activity relationships. Docking analysis indicates that methylenedioxys at R2 and R3 is involved in the effect. More studies in other cells are needed to confirm our results.
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 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.
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.
