Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA v...Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.展开更多
Genomic DNA for Jatropha curcas ribosome inactivating protein （JRIP） was cloned from total DNA of its leaves by polymerase chain reaction （PCR）. The no intron character was confirmed. The plant expression vector p...Genomic DNA for Jatropha curcas ribosome inactivating protein （JRIP） was cloned from total DNA of its leaves by polymerase chain reaction （PCR）. The no intron character was confirmed. The plant expression vector pBI121-JRIP was constructed by inserting the JRIP gene into pBI121 plasmid. The recombinant Agrobacterium EHA105 strain harboring pBI121-JRIP was constructed by conducting pBI121-JRIP to strain EHA 105. PCR and Southern blotting were carried out, and the results proved that the JRIP gene was integrated into tobacco genome. It might provide a new material for disease resistance tobacco species breeding.展开更多
AIM： To study the role of CDH1/E-cadherin （E-cad） gene alteration profiles including mutation, loss of heterozygosity （LOH）, promoter polymorphism and hypermethylation in mechanisms of CDH1 inactivation in gastri...AIM： To study the role of CDH1/E-cadherin （E-cad） gene alteration profiles including mutation, loss of heterozygosity （LOH）, promoter polymorphism and hypermethylation in mechanisms of CDH1 inactivation in gastric carcinoma （GC）. METHODS： Specimens were collected surgically from 70 patients with GC. Allelotyping PCR and detection of LOH, denaturing high pressure liquid chromatography and DNA sequencing, restriction fragment length polymorphism analysis, methylation specific PCR, and immunohistochemical staining were used. RESULTS： Promoter polymorphism was not a major mechanism of E-cad inactivation. Only one truncating mutation was found in a diffuse type tumor （3%）. Both LOH and promoter hypermethylation were major mechanisms of E-cad inactivation, but interestingly, there was a negative association between the fraction of allelic loss （LOH） in tumors and hypermethylation of CDH1. Therefore LOH and hypermethylation were two different tumorigenic pathways involved in GC. CONCLUSION： Given the findings that somatic mutation was extremely low and the relationship between LOH and hypermethylation was inverse, any two combinations of these three factors cannot fulfill the classical two-hit hypothesis of CDH1 inactivation. Thus, other mechanisms operating at the transcriptional level or at the post-translational level might be required to induce E-cadherin inactivation.展开更多
A new ribosome-inactivating protein （RIP） with a molecular weight of 31 kDa induced by Cinchonaglycoside C （1） designated CIP31, was isolated from tobacco leaves. Analysis of this protein sequence indicated that i...A new ribosome-inactivating protein （RIP） with a molecular weight of 31 kDa induced by Cinchonaglycoside C （1） designated CIP31, was isolated from tobacco leaves. Analysis of this protein sequence indicated that it belongs to the RIP family and it was distinct from the other plant RIPs reported previously at its N-terminal amino acid sequence. CIP31 can directly impair synthesis of coat protein （CP） of tobacco mosaic virus （TMV）, which resulted in inhibition of TMV long distance movement and multiplication in tobacco plants at concentrations of ng/mL. Furthermore, no toxicity was shown to the growth and fertility of the plants. CIP31 was synthesized only in the presence of Cinchonaglycoside C （1） and was independent of the salicylic acid （SA） signal pathway. We provided evidence for the SA-independent biological induction of resistance.展开更多
Dear Editor,Genome-scale screening is a powerful method used to explore phenotypes that are of interest,and numerous screening systems have been built for functional sites identification.Classical genetic screening in...Dear Editor,Genome-scale screening is a powerful method used to explore phenotypes that are of interest,and numerous screening systems have been built for functional sites identification.Classical genetic screening in eukaryotes has been performed using chemical mutagens(Chen et al.,2000),transposon mediated gene trapping(Dupuy et al.,2005),and CRISPR-Cas9 system(Wang et al.,2014).展开更多
The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by deposit...The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight.展开更多
Solar-driven Fenton-like reactions are promising strategies for degrading pharmaceutical wastewater to address environmental challenges and antibiotic pollution.However,its efficacy is limited by suboptimal light abso...Solar-driven Fenton-like reactions are promising strategies for degrading pharmaceutical wastewater to address environmental challenges and antibiotic pollution.However,its efficacy is limited by suboptimal light absorption efficiency,rapid charge recombination,and inadequate interfacial charge transfer.In this study,an inorganic/organic S-scheme photo-Fenton system of pseudobrookite/carbon nitride(FTOCN)was synthesized via a hydrothermally coupled calcination process for the effective purification of tetracycline antibiotics under visible-light irradiation.The optimized FTOCN-2 heterostructure exhibits a significantly enhanced TC degradation capacity of 90%within 60 min.The rate constant of FTOCN-2 is 1.6 and 5.2 times greater than those of FTO and CN,respectively.Furthermore,FTOCN exhibits high antibacterial efficacy,highlighting its potential application in the purification of natural water.Measurements via a range of analytical techniques,including Kelvin probe force microscopy,density functional theory calculations,in situ X-ray photoelectron spectroscopy,and femtosecond transient absorption spectroscopy,corroborate the S-scheme mechanism.This study provides a novel perspective for the development of photo-Fenton systems with S-scheme heterojunctions for water purification.展开更多
Minks are highly susceptible to SARS-CoV-2,and have transmitted SARS-CoV-2 to humans.Oral immunization is one of the most promising strategies to prevent SARS-CoV-2 infection and transmission in minks.Here,we generate...Minks are highly susceptible to SARS-CoV-2,and have transmitted SARS-CoV-2 to humans.Oral immunization is one of the most promising strategies to prevent SARS-CoV-2 infection and transmission in minks.Here,we generated 3 recombinant rabies viruses(RABV),rERAG_(333E)/S6P,rERAG_(333E)/DS6P and rERAG_(333E)/BA2S6P,expressing the prefusion-stabilized SARS-CoV-2 spike protein of wild-type(S6P),δ(DS6P)or BA.2(BA2S6P)strain based on an oral rabies vaccine candidate(rERAG_(333E)).Oral or inactivated immunization of the 3 RABVs monovalent or trivalent were safe,and induced robust RABV neutralizing antibody and cross-antibody responses against the three SARS-CoV-2 in mice and minks.The challenge tests showed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine completely protected mice against mouse-adapted SARS-CoV-2 infection in the upper and lower respiratory tracts,and largely prevented viral replication and lung damage caused by wild-type SARS-CoV-2infection in minks.Notably,we also confirmed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine can largely protect minks against wild-type SARS-CoV-2 transmission via respiratory droplets.Our findings suggest that rERAG_(333E)-based COVID-19 vaccines appear to be suitable oral candidates to protect minks from SARS-CoV-2infection and transmission,and may serve as inactivated vaccines for further investigation in humans.展开更多
Dent disease is a rare X-linked recessively inherited renal tubulopathy,caused by variants in the CLCN5(Dent disease type 1,DD1)and OCRL(Dent disease type 2,DD2)genes,and characterized by low molecular weight proteinu...Dent disease is a rare X-linked recessively inherited renal tubulopathy,caused by variants in the CLCN5(Dent disease type 1,DD1)and OCRL(Dent disease type 2,DD2)genes,and characterized by low molecular weight proteinuria,hypercalciuria,microscopic hematuria,or nephrocalcinosis.In the current study,we collected and analyzed clinical data and genetic testing results of 21 children diagnosed with Dent disease,who were hospitalized at the Department of Nephrology,Children's Hospital of Nanjing Medical University between January 2014 and August 2023,aiming to assist in the early diagnosis and treatment of these patients.Among the 21 patients,16(76.19%)had CLCN5 variants,and five(23.81%)had OCRL variants,and four of the variants were novel.All patients presented with low molecular weight proteinuria,14(66.67%)of whom had nephroticrange proteinuria.Eight patients underwent renal biopsies because of diagnostic uncertainty.We transfected the novel CLCN5 missense variant(p.G222R)and OCRL missense variant(p.I371T)plasmids into both HEK293 and HK-2 cells and found a significantly lower expression of the OCRL1 protein in the transfected cells than in the wild-type cells(P<0.05).Moreover,we observed an extremely skewed X-chromosome inactivation pattern in a female patient carrying the same novel CLCN5 variant,as assessed by the human androgen receptor gene assay.These findings provide insight into the clinical characteristics of Dent disease in Chinese patients and may shed light on its pathogenesis.展开更多
Ionizing radiation presents an important solution for virus inactivation.However,its efficacy for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)inactivation and the underlying mechanisms remain unclear.Th...Ionizing radiation presents an important solution for virus inactivation.However,its efficacy for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)inactivation and the underlying mechanisms remain unclear.This study demonstrates radiosensitivity and radiation-induced biological changes in SARS-CoV-2 using 20 wild-type and mutant strains.The results show that 1.2 kGy of electron beam(E-beam)or 0.9 kGy of X-ray irradiation can eliminate 99.99%of SARS-CoV-2 particles.The Delta and various Omicron variants exhibit heightened sensitivity to radiation compared to the wild-type,showing nearly 99.99%inactivation efficiency at 1.0 and 0.8 kGy.The relationship between irradiation dose and the logarithmic reduction in virus load adheres to a dose-response model,characterized by extremely narrow windows.Spike(S)protein disruption,rather than the commonly accepted nucleic acid cleavage,is identified as the primary inactivation mechanism(triggering a conformation transition of S protein from pre-fusion to post-fusion with minimal impact on nucleic acid integrity).This study introduces the concept of targeting critical proteins in coronavirus inactivation,offering valuable insight for infectious coronavirus disease control and vaccine development.展开更多
The cranial base synchondroses,comprised of opposite-facing bidirectional chondrocyte layers,drive anteroposterior cranial base growth.In humans,RUNX2 haploinsufficiency causes cleidocranial dysplasia associated with ...The cranial base synchondroses,comprised of opposite-facing bidirectional chondrocyte layers,drive anteroposterior cranial base growth.In humans,RUNX2 haploinsufficiency causes cleidocranial dysplasia associated with deficient midfacial growth.However,how RUNX2 regulates chondrocytes in the cranial base synchondroses remains unknown.To address this,we inactivated Runx2 in postnatal synchondrosis chondrocytes using a tamoxifen-inducible Fgfr3-creER(Fgfr3-Runx2cKO)mouse model.Fgfr3-Runx2cKO mice displayed skeletal dwarfism and reduced anteroposterior cranial base growth associated with premature synchondrosis ossification due to impaired chondrocyte proliferation,accelerated hypertrophy,apoptosis,and osteoclast-mediated cartilage resorption.Lineage tracing reveals that Runx2-deficient Fgfr3+cells failed to differentiate into osteoblasts.Notably,Runx2-deficient chondrocytes showed an elevated level of FGFR3 and its downstream signaling components,pERK1/2 and SOX9,suggesting that RUNX2 downregulates FGFR3 in the synchondrosis.This study unveils a new role of Runx2 in cranial base chondrocytes,identifying a possible RUNX2-FGFR3-MAPK-SOX9 signaling axis that may control cranial base growth.展开更多
Dear Editor,Viruses of the genus Orthoebolavirus cause sporadic outbreaks of severe haemorrhagic fever,with case fatality rates ranging from 25%to 90%(Mahanty and Bray,2004).Six species of the virus(Orthoebolavirus za...Dear Editor,Viruses of the genus Orthoebolavirus cause sporadic outbreaks of severe haemorrhagic fever,with case fatality rates ranging from 25%to 90%(Mahanty and Bray,2004).Six species of the virus(Orthoebolavirus zairense,sudanense,bundibugyoense,taiense,restonense,and bombaliense)have so far been identified(Biedenkopf et al.,2023).Among these,Orthoebolavirus zairense,commonly known as Ebola virus(EBOV),stands out as the most virulent.Given its high contagiousness and lethality,EBOV must be manipulated under biosafety level 4(BSL-4)conditions,as stipulated by the the People's Republic of China's list of human pathogenic microorganisms(National Health Commission of the People’s Republic of China,2023).Prior to being removed from a BSL-4 laboratory,it is imperative that infectious EBOV undergoes complete inactivation.Here we systematically evaluate viral thermostability under BSL-4 containment conditions,demonstrating EBOV's marked thermotolerance.展开更多
The natural curcumin-mediated photodynamic inactivation(PDI)was developed,and its inactivation potency against Fusarium graminearum in vitro and in vivo was systematically investigated by fluorescence probe assay,tryp...The natural curcumin-mediated photodynamic inactivation(PDI)was developed,and its inactivation potency against Fusarium graminearum in vitro and in vivo was systematically investigated by fluorescence probe assay,trypan blue staining,scanning electron microscope(SEM),confocal laser scanning microscopy(CLSM),etc.Results showed that under the irradiation of blue LED,the photosensitizer of curcumin was excited to generate massive reactive oxygen species(ROS)in the cells of F.graminearum,and the PDI completely inactivated their mycelia and spores under the treatment of 150μM curcumin and 10.8 J/cm^(2)irradiation.Further analysis found that the PDI ruptured the cellular microstructures,damaged the cell membrane by increasing its permeability and oxidizing the lipids,degraded the intracellular DNA and proteins inside the spores of F.graminearum.Meanwhile,the PDI also potently killed>99.99%spores of F.graminearum on maize under the treatment of 200μM curcumin and 10.8 J/cm^(2)irradiation.Moreover,the PDI suppressed the production of zearalenone(ZEN),and residual ZEN could not be detected after the storage of maize for 10 days.Therefore,this study systematically explored the inactivation efficiency of curcumin-mediated PDI against both the mycelia and spores of F.graminearum,which provides a valid and promising method to control the fungal hazards in grains.展开更多
Porcine epidemic diarrhea virus(PEDV)infection causes acute watery diarrhea in neonatal piglets,leading to substantial economic losses within the pig farming industry.This study demonstrates that clofazimine(CFZ)signi...Porcine epidemic diarrhea virus(PEDV)infection causes acute watery diarrhea in neonatal piglets,leading to substantial economic losses within the pig farming industry.This study demonstrates that clofazimine(CFZ)significantly inhibits PEDV replication in a dose-dependent manner in vitro,with negligible cytotoxicity.Findings from our time-of-addition assays indicate that CFZ effectively disrupts multiple stages of the viral infection cycle.Using a CoV-RdRp-Gluc reporter system,we evaluated the potency of CFZ against PEDV RNA-dependent RNA polymerase(RdRp),and determined a low IC50 value of 0.1364μM.Molecular docking studies further confirmed that CFZ has high binding affinity at the active sites of the spike protein and RdRp protein in PEDV.Transcriptome analysis of Vero E6 cells,with and without CFZ treatment,revealed a significant change in transcriptional activity at 8 h postinfection(hpi).Moreover,the simultaneous application of CFZ and nucleoside analogs showed enhanced the anti-PEDV effect of CFZ in vitro.Our study underscores the potential of CFZ as a viable therapeutic agent against PEDV.展开更多
BACKGROUND Autoimmune encephalitis(AE)is a rare and recently described neuroinflammatory disease associated with specific autoantibodies.Anti-leucine-rich glioma inactivated 1(anti-LGI1)encephalitis is a rare but trea...BACKGROUND Autoimmune encephalitis(AE)is a rare and recently described neuroinflammatory disease associated with specific autoantibodies.Anti-leucine-rich glioma inactivated 1(anti-LGI1)encephalitis is a rare but treatable type of AE discovered in recent years.Alzheimer’s disease(AD)is a degenerative brain disease and the most common cause of dementia.AD may undergo a series of pathological physiological changes in brain tissue 20 years before the onset of typical symptoms.The stage of mild cognitive impairment(MCI)that occurs during this process,known as MCI due to AD,is the earliest stage with clinical symptoms.MCI is typically categorized into two subtypes:Amnestic MCI(aMCI)and non-aMCI.CASE SUMMARY This report describes a patient with rapid cognitive impairment,diagnosed with anti-LGI1 antibody-mediated AE and aMCI,and treated at Peking University Shenzhen Hospital in March 2023.The patient was hospitalized with acute memory decline for more than 3 months.Both the cerebrospinal fluid and serum were positive for anti-LGI1 antibodies,biomarkers of AD coexisting in the patient’s cerebrospinal fluid.Following combination treatment with immunoglobulin therapy and glucocorticoid,plus inhibition of acetylcholinesterase,the patient’s cognitive function significantly improved.Throughout the 3-month follow-up period,a sustained improvement in cognitive function was observed.The results of serum anti-LGI1 antibody were negative.CONCLUSION This case has raised awareness of the possible interaction between AE and early AD(including MCI due to AD),and alerted clinicians to the possibility of concurrent rare and common diseases in patients presenting with cognitive impairment.展开更多
Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we gener...Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we generated a novel mouse model with a conditional C451A mutation in Esr1,which enables selective knockout of the palmitoylation site essential for the membrane localization of ERα(C451A^(f/f)).First,we used Runx2-Cre mice to generate Runx2-C451A^(f/f)mice with conditional inactivation of mERαsignaling in Runx2-expressing osteoblast lineage cells.No significant changes were observed in body weight,weights of estrogen-responsive organs,or serum concentrations of estradiol between female Runx2-C451A^(f/f)and homozygous C451A^(f/f)littermate controls.High-resolution microcomputed tomography analysis showed a consistent decrease in cortical bone mass in the tibia,femur,and vertebra L5 of Runx2-C451A^(f/f)mice and three-point bending analysis of humerus revealed an impaired mechanical bone strength in Runx2-C451A^(f/f)female mice compared to controls.Additionally,primary osteoblast cultures from mice lacking mERαsignaling showed impaired differentiation compared to controls.展开更多
H_(2)O_(2)is an environmentally friendly oxidizing agent with minimal secondary pollution;however,its application has always been constrained by factors such as storage and transportation.In this study,we propose an i...H_(2)O_(2)is an environmentally friendly oxidizing agent with minimal secondary pollution;however,its application has always been constrained by factors such as storage and transportation.In this study,we propose an innovative method for storing and releasing H_(2)O_(2)using hydrogels.Commercial hydrogels(sodium polyacrylate)can undergo swelling and absorb H_(2)O_(2)in aqueous solutions,and the swollen hydrogel can continuously release H_(2)O_(2)under osmotic pressure.And the characteristics of osmotic pressure drive ensure the recyclability of hydrogel for H_(2)O_(2)storage.Experimental results demonstrate that H_(2)O_(2)can stably exist within the hydrogel for an extended period,and this strategy helps to avoid explosion the risk and potential environmental hazards during the transportation of H_(2)O_(2).Finally,experiments confirm that the hydrogel controlled sustained release of H_(2)O_(2)is effective in both Fenton reactions and the process of bacterial inactivation.This work introduces new ideas for the storage of H_(2)O_(2),and the sustained release of H_(2)O_(2)may have significant implications in the fields of healthcare,environmental science,catalysis,and beyond.展开更多
Coronaviruses are single-stranded,positive-sense RNA enveloped viruses that have posed a significant threat to human health over the past few decades,particularly severe acute respiratory syndrome coronavirus(SARS-CoV...Coronaviruses are single-stranded,positive-sense RNA enveloped viruses that have posed a significant threat to human health over the past few decades,particularly severe acute respiratory syndrome coronavirus(SARS-CoV),Middle East respiratory syndrome coronavirus(MERS-CoV),and SARS-CoV-2.These viruses have caused widespread infections and fatalities,with profound impacts on global economies,social life,and public health systems.Due to their broad host range in natural settings and the consequent high potential for zoonotic spillover events,a thorough investigation of the common viral mechanisms and the identification of druggable targets for pan-coronavirus antiviral development are of utmost importance.展开更多
ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. Th...ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1：1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.展开更多
β-N-Acetyl-D-glucosaminidase （NAGase, EC.3.2.1.52） is chitinolytic enzymes and disintegrate dimmer and trimer a composition of oligomers of N-acetyl-β-D-glucosamine （NAG） into monomer. Prawn （P. vannamei） NAG...β-N-Acetyl-D-glucosaminidase （NAGase, EC.3.2.1.52） is chitinolytic enzymes and disintegrate dimmer and trimer a composition of oligomers of N-acetyl-β-D-glucosamine （NAG） into monomer. Prawn （P. vannamei） NAGase is involved in digestion and molting processes. Some pollutants in seawater affect the enzyme activity causing loss of the biological function of the enzyme, which affects the exuviating shell and threatens the survival of the animal. The effect of formaldehyde on prawn （P. vannamei） β-N-acetyl-D-glucosaminidase activity for the hydrolysis of pNP-NAG has been studied. The results show that formaldehyde, at appropriate concentrations, can lead to reversible inactivation of the enzyme, and the IC50 is estimated to be 1.05mol· L^-1. The inactivation mechanism obtained from Lineweaver-Burk plots shows that the inactivation of the enzyme by formaldehyde belongs to the competitive type. The inactivation kinetics of the enzyme by formaldehyde has been studied using the progress-of-substrate-reaction method described by Tsou, and the rate constants have been determined. The results show that k＋0 is much larger than k-0, indicating the free enzyme molecule is fragile in the formaldehyde solution.展开更多
基金Indo-Swiss Joint research Program (ISJRP)#17/2011
文摘Many plants contain ribosome inactivating proteins (RIPs) with N-glycosidase activity, which depurinate large ribosomal RNA and arrest protein synthesis. RIPs so far tested inhibit replication of mRNA as well as DNA viruses and these proteins, isolated from plants, are found to be effective against a broad range of viruses such as human immunodeficiency virus (HIV), hepatitis B virus (HBV) and herpes simplex virus (HSV). Most of the research work related to RIPs has been focused on antiviral activity against HIV; however, the exact mechanism of antiviral activity is still not clear. The mechanism of antiviral activity was thought to follow inactivation of the host cell ribosome, leading to inhibition of viral protein translation and host cell death. Enzymatic activity of RIPs is not limited to depurination of the large rRNA, in addition they can depurinate viral DNA as well as RNA. Recently, Phase I/II clinical trials have demonstrated the potential use of RIPs for treating patients with HIV disease. The aim of this review is to focus on various RIPs from plants associated with anti-HIV activity.
基金Project supported by Tenth Five Years Key Program Foundation of the State Science and Technology Commission of China (GrantNo .2002BA901A15)
文摘Genomic DNA for Jatropha curcas ribosome inactivating protein （JRIP） was cloned from total DNA of its leaves by polymerase chain reaction （PCR）. The no intron character was confirmed. The plant expression vector pBI121-JRIP was constructed by inserting the JRIP gene into pBI121 plasmid. The recombinant Agrobacterium EHA105 strain harboring pBI121-JRIP was constructed by conducting pBI121-JRIP to strain EHA 105. PCR and Southern blotting were carried out, and the results proved that the JRIP gene was integrated into tobacco genome. It might provide a new material for disease resistance tobacco species breeding.
基金Supported by Clinical Research Fund of the Tri-Service General Hospital and C.Y.Fundation for Advancement of Education, Science and Medicine, Taipei, Taiwan, China
文摘AIM： To study the role of CDH1/E-cadherin （E-cad） gene alteration profiles including mutation, loss of heterozygosity （LOH）, promoter polymorphism and hypermethylation in mechanisms of CDH1 inactivation in gastric carcinoma （GC）. METHODS： Specimens were collected surgically from 70 patients with GC. Allelotyping PCR and detection of LOH, denaturing high pressure liquid chromatography and DNA sequencing, restriction fragment length polymorphism analysis, methylation specific PCR, and immunohistochemical staining were used. RESULTS： Promoter polymorphism was not a major mechanism of E-cad inactivation. Only one truncating mutation was found in a diffuse type tumor （3%）. Both LOH and promoter hypermethylation were major mechanisms of E-cad inactivation, but interestingly, there was a negative association between the fraction of allelic loss （LOH） in tumors and hypermethylation of CDH1. Therefore LOH and hypermethylation were two different tumorigenic pathways involved in GC. CONCLUSION： Given the findings that somatic mutation was extremely low and the relationship between LOH and hypermethylation was inverse, any two combinations of these three factors cannot fulfill the classical two-hit hypothesis of CDH1 inactivation. Thus, other mechanisms operating at the transcriptional level or at the post-translational level might be required to induce E-cadherin inactivation.
基金the NationaI NaturaI Science Foundation of China(30370957)the NaturaI Science Foundation of Yunnan Province(2003C0061M).
文摘A new ribosome-inactivating protein （RIP） with a molecular weight of 31 kDa induced by Cinchonaglycoside C （1） designated CIP31, was isolated from tobacco leaves. Analysis of this protein sequence indicated that it belongs to the RIP family and it was distinct from the other plant RIPs reported previously at its N-terminal amino acid sequence. CIP31 can directly impair synthesis of coat protein （CP） of tobacco mosaic virus （TMV）, which resulted in inhibition of TMV long distance movement and multiplication in tobacco plants at concentrations of ng/mL. Furthermore, no toxicity was shown to the growth and fertility of the plants. CIP31 was synthesized only in the presence of Cinchonaglycoside C （1） and was independent of the salicylic acid （SA） signal pathway. We provided evidence for the SA-independent biological induction of resistance.
文摘Dear Editor,Genome-scale screening is a powerful method used to explore phenotypes that are of interest,and numerous screening systems have been built for functional sites identification.Classical genetic screening in eukaryotes has been performed using chemical mutagens(Chen et al.,2000),transposon mediated gene trapping(Dupuy et al.,2005),and CRISPR-Cas9 system(Wang et al.,2014).
基金supported by the Science and Technology Planning Project of Fujian Province(No.2023Y4015)the Marine and Fishery Development Special Fund of Xiamen(No.23YYST064QCB36)the Natural Science Foundation of Fujian Province(No.2021J011210).
文摘The removal of ammonia nitrogen(NH_(4)^(+)-N)and bacteria from aquaculture wastewater holds paramount ecological and production significance.In this study,Pt/RuO_(2)/g-C_(3)N_(4)photocatalysts were prepared by depositing Pt and RuO_(2)particles onto g-C_(3)N_(4).The physicochemical properties of photocatalysts were explored by X-ray photoelectron spectroscopy(XPS),scanning electron microscopy(SEM),X-ray diffraction(XRD),and UV–vis diffuse reflectance spectrometer(UV–vis DRS).The photocatalysts were then applied to the removal of both NH_(4)^(+)-N and bacteria from simulated mariculture wastewater.The results clarified that the removals of both NH_(4)^(+)-N and bacteria were in the sequence of g-C_(3)N_(4)<RuO_(2)/g-C_(3)N_(4)<Pt/g-C_(3)N_(4)<Pt/RuO_(2)/g-C_(3)N_(4).This magnificent photocatalytic ability of Pt/RuO_(2)/g-C_(3)N_(4)can be interpreted by the transfer of holes from g-C_(3)N_(4)to RuO_(2)to facilitate the in situ generation of HClO from Cl^(−)in wastewater,while Pt extracts photogenerated electrons for H_(2)formation to enhance the reaction.The removal of NH_(4)^(+)-N and disinfection effect were more pronounced in simulated seawater than in purewater.The removal efficiency ofNH_(4)^(+)-N increases with an increase in pH of wastewater,while the bactericidal effect was more significant under a lower pH in a pH range of 6–9.In actual seawater aquaculture wastewater,Pt/RuO_(2)/g-C_(3)N_(4)still exhibits effective removal efficiency of NH_(4)^(+)-N and bactericidal performance under sunlight.This study provides an alternative avenue for removement of NH_(4)^(+)-N and bacteria from saline waters under sunlight.
文摘Solar-driven Fenton-like reactions are promising strategies for degrading pharmaceutical wastewater to address environmental challenges and antibiotic pollution.However,its efficacy is limited by suboptimal light absorption efficiency,rapid charge recombination,and inadequate interfacial charge transfer.In this study,an inorganic/organic S-scheme photo-Fenton system of pseudobrookite/carbon nitride(FTOCN)was synthesized via a hydrothermally coupled calcination process for the effective purification of tetracycline antibiotics under visible-light irradiation.The optimized FTOCN-2 heterostructure exhibits a significantly enhanced TC degradation capacity of 90%within 60 min.The rate constant of FTOCN-2 is 1.6 and 5.2 times greater than those of FTO and CN,respectively.Furthermore,FTOCN exhibits high antibacterial efficacy,highlighting its potential application in the purification of natural water.Measurements via a range of analytical techniques,including Kelvin probe force microscopy,density functional theory calculations,in situ X-ray photoelectron spectroscopy,and femtosecond transient absorption spectroscopy,corroborate the S-scheme mechanism.This study provides a novel perspective for the development of photo-Fenton systems with S-scheme heterojunctions for water purification.
基金supported by the National Key Research and Development Program of China(2021YFC2301700)the Natural Science Foundation of Heilongjiang Province,China(YQ2022C040)。
文摘Minks are highly susceptible to SARS-CoV-2,and have transmitted SARS-CoV-2 to humans.Oral immunization is one of the most promising strategies to prevent SARS-CoV-2 infection and transmission in minks.Here,we generated 3 recombinant rabies viruses(RABV),rERAG_(333E)/S6P,rERAG_(333E)/DS6P and rERAG_(333E)/BA2S6P,expressing the prefusion-stabilized SARS-CoV-2 spike protein of wild-type(S6P),δ(DS6P)or BA.2(BA2S6P)strain based on an oral rabies vaccine candidate(rERAG_(333E)).Oral or inactivated immunization of the 3 RABVs monovalent or trivalent were safe,and induced robust RABV neutralizing antibody and cross-antibody responses against the three SARS-CoV-2 in mice and minks.The challenge tests showed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine completely protected mice against mouse-adapted SARS-CoV-2 infection in the upper and lower respiratory tracts,and largely prevented viral replication and lung damage caused by wild-type SARS-CoV-2infection in minks.Notably,we also confirmed that 2 doses of rERAG_(333E)-S6P as an oral or inactivated vaccine can largely protect minks against wild-type SARS-CoV-2 transmission via respiratory droplets.Our findings suggest that rERAG_(333E)-based COVID-19 vaccines appear to be suitable oral candidates to protect minks from SARS-CoV-2infection and transmission,and may serve as inactivated vaccines for further investigation in humans.
基金supported by the National Natural Science Foundation of China(Grant No.82200744)the Nanjing Science and Technology Development Funding(Grant No.YKK22159).
文摘Dent disease is a rare X-linked recessively inherited renal tubulopathy,caused by variants in the CLCN5(Dent disease type 1,DD1)and OCRL(Dent disease type 2,DD2)genes,and characterized by low molecular weight proteinuria,hypercalciuria,microscopic hematuria,or nephrocalcinosis.In the current study,we collected and analyzed clinical data and genetic testing results of 21 children diagnosed with Dent disease,who were hospitalized at the Department of Nephrology,Children's Hospital of Nanjing Medical University between January 2014 and August 2023,aiming to assist in the early diagnosis and treatment of these patients.Among the 21 patients,16(76.19%)had CLCN5 variants,and five(23.81%)had OCRL variants,and four of the variants were novel.All patients presented with low molecular weight proteinuria,14(66.67%)of whom had nephroticrange proteinuria.Eight patients underwent renal biopsies because of diagnostic uncertainty.We transfected the novel CLCN5 missense variant(p.G222R)and OCRL missense variant(p.I371T)plasmids into both HEK293 and HK-2 cells and found a significantly lower expression of the OCRL1 protein in the transfected cells than in the wild-type cells(P<0.05).Moreover,we observed an extremely skewed X-chromosome inactivation pattern in a female patient carrying the same novel CLCN5 variant,as assessed by the human androgen receptor gene assay.These findings provide insight into the clinical characteristics of Dent disease in Chinese patients and may shed light on its pathogenesis.
基金supported by the National Key Research and Development Program of China(2024YFC2309900 and 2021YFC2301200)the Zhejiang Plan for the Special Support for Top-notch Talents in China(2022R52029)+1 种基金the Fundamental Research Funds for the Central Universities(2022ZFJH003)the Hangzhou Global Scientific and Technological Innovation Center of Zhejiang University(KC2021ZY0B0002).
文摘Ionizing radiation presents an important solution for virus inactivation.However,its efficacy for severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)inactivation and the underlying mechanisms remain unclear.This study demonstrates radiosensitivity and radiation-induced biological changes in SARS-CoV-2 using 20 wild-type and mutant strains.The results show that 1.2 kGy of electron beam(E-beam)or 0.9 kGy of X-ray irradiation can eliminate 99.99%of SARS-CoV-2 particles.The Delta and various Omicron variants exhibit heightened sensitivity to radiation compared to the wild-type,showing nearly 99.99%inactivation efficiency at 1.0 and 0.8 kGy.The relationship between irradiation dose and the logarithmic reduction in virus load adheres to a dose-response model,characterized by extremely narrow windows.Spike(S)protein disruption,rather than the commonly accepted nucleic acid cleavage,is identified as the primary inactivation mechanism(triggering a conformation transition of S protein from pre-fusion to post-fusion with minimal impact on nucleic acid integrity).This study introduces the concept of targeting critical proteins in coronavirus inactivation,offering valuable insight for infectious coronavirus disease control and vaccine development.
基金National Institutes of Health grant F30DE030675(S.A.H.)National Institutes of Health grant T32DE007057(S.A.H.)+7 种基金University of Michigan Rackham Graduate School Pre-Candidate Research Grant(S.A.H.)University of Michigan Rackham Graduate School Candidate Research Grant(S.A.H.)National Institutes of Health grant R35DE034348(N.O.)National Institutes of Health grant R01DE026666(N.O.)National Institutes of Health grant R01DE030630(N.O.)National Institutes of Health grant R01DE029465(R.T.F.)Department of Defense grant W81XWH2010571(R.T.F.)National Institutes of Health grant P30 AR069620(The Michigan Integrative Musculoskeletal.Health Core Center).
文摘The cranial base synchondroses,comprised of opposite-facing bidirectional chondrocyte layers,drive anteroposterior cranial base growth.In humans,RUNX2 haploinsufficiency causes cleidocranial dysplasia associated with deficient midfacial growth.However,how RUNX2 regulates chondrocytes in the cranial base synchondroses remains unknown.To address this,we inactivated Runx2 in postnatal synchondrosis chondrocytes using a tamoxifen-inducible Fgfr3-creER(Fgfr3-Runx2cKO)mouse model.Fgfr3-Runx2cKO mice displayed skeletal dwarfism and reduced anteroposterior cranial base growth associated with premature synchondrosis ossification due to impaired chondrocyte proliferation,accelerated hypertrophy,apoptosis,and osteoclast-mediated cartilage resorption.Lineage tracing reveals that Runx2-deficient Fgfr3+cells failed to differentiate into osteoblasts.Notably,Runx2-deficient chondrocytes showed an elevated level of FGFR3 and its downstream signaling components,pERK1/2 and SOX9,suggesting that RUNX2 downregulates FGFR3 in the synchondrosis.This study unveils a new role of Runx2 in cranial base chondrocytes,identifying a possible RUNX2-FGFR3-MAPK-SOX9 signaling axis that may control cranial base growth.
基金supported by the Youth Innovation Promotion Association of CAS(2023350 to Xiaoxiao Gao).
文摘Dear Editor,Viruses of the genus Orthoebolavirus cause sporadic outbreaks of severe haemorrhagic fever,with case fatality rates ranging from 25%to 90%(Mahanty and Bray,2004).Six species of the virus(Orthoebolavirus zairense,sudanense,bundibugyoense,taiense,restonense,and bombaliense)have so far been identified(Biedenkopf et al.,2023).Among these,Orthoebolavirus zairense,commonly known as Ebola virus(EBOV),stands out as the most virulent.Given its high contagiousness and lethality,EBOV must be manipulated under biosafety level 4(BSL-4)conditions,as stipulated by the the People's Republic of China's list of human pathogenic microorganisms(National Health Commission of the People’s Republic of China,2023).Prior to being removed from a BSL-4 laboratory,it is imperative that infectious EBOV undergoes complete inactivation.Here we systematically evaluate viral thermostability under BSL-4 containment conditions,demonstrating EBOV's marked thermotolerance.
基金supported by the National Key Research and Development Program of China(2022YFE0139500)National Natural Science Foundation of China(32102105)+3 种基金Guangdong Basic and Applied Basic Research Foundation(2024A15150130262023A1515140136)Special Projects in Key Areas of Higher Education Institution in Guangdong Province(2024ZDZX2090)Guangdong Provincial Key Laboratory of Intelligent Food Manufacturing(2022B1212010015)。
文摘The natural curcumin-mediated photodynamic inactivation(PDI)was developed,and its inactivation potency against Fusarium graminearum in vitro and in vivo was systematically investigated by fluorescence probe assay,trypan blue staining,scanning electron microscope(SEM),confocal laser scanning microscopy(CLSM),etc.Results showed that under the irradiation of blue LED,the photosensitizer of curcumin was excited to generate massive reactive oxygen species(ROS)in the cells of F.graminearum,and the PDI completely inactivated their mycelia and spores under the treatment of 150μM curcumin and 10.8 J/cm^(2)irradiation.Further analysis found that the PDI ruptured the cellular microstructures,damaged the cell membrane by increasing its permeability and oxidizing the lipids,degraded the intracellular DNA and proteins inside the spores of F.graminearum.Meanwhile,the PDI also potently killed>99.99%spores of F.graminearum on maize under the treatment of 200μM curcumin and 10.8 J/cm^(2)irradiation.Moreover,the PDI suppressed the production of zearalenone(ZEN),and residual ZEN could not be detected after the storage of maize for 10 days.Therefore,this study systematically explored the inactivation efficiency of curcumin-mediated PDI against both the mycelia and spores of F.graminearum,which provides a valid and promising method to control the fungal hazards in grains.
基金supported by a grant from the National Key Research and Development Plans of China(No.2021YFD1800401)to Zhe Wangthe National Natural Science Foundation of China(No.32070128)to Zhe Wang+5 种基金the Shanghai Biomedical Science and Technology Support Special Project(No.21S11900200)to Zhe Wangthe National Natural Science Foundation of China(No.31472211)to ZhiBiao Yangthe Natural Science Foundation of Shanghai(No.21ZR1433900)to Zhibiao Yangthe National Key Research and Development Program of China(No.2022YFD1800805)to Yanjun Zhouthe Pinduoduo-China Agricultural University Research Fund(PC2024A01003)to Xiangfeng Wangthe Biomedicine and Technology Supporting Project of the Shanghai Science and Technology Innovation Plan(Grant No.22S11902200,China)to Tao Sun.
文摘Porcine epidemic diarrhea virus(PEDV)infection causes acute watery diarrhea in neonatal piglets,leading to substantial economic losses within the pig farming industry.This study demonstrates that clofazimine(CFZ)significantly inhibits PEDV replication in a dose-dependent manner in vitro,with negligible cytotoxicity.Findings from our time-of-addition assays indicate that CFZ effectively disrupts multiple stages of the viral infection cycle.Using a CoV-RdRp-Gluc reporter system,we evaluated the potency of CFZ against PEDV RNA-dependent RNA polymerase(RdRp),and determined a low IC50 value of 0.1364μM.Molecular docking studies further confirmed that CFZ has high binding affinity at the active sites of the spike protein and RdRp protein in PEDV.Transcriptome analysis of Vero E6 cells,with and without CFZ treatment,revealed a significant change in transcriptional activity at 8 h postinfection(hpi).Moreover,the simultaneous application of CFZ and nucleoside analogs showed enhanced the anti-PEDV effect of CFZ in vitro.Our study underscores the potential of CFZ as a viable therapeutic agent against PEDV.
基金Supported by the Shenzhen Science and Technology Program,No.JCYJ20220818102810022Shenzhen University Teaching Reform fund,No.JG2023166+1 种基金National Natural Science Foundation of China,No.12231018Science and Technology Innovation 2030-Major Project,No.2021ZD0201805.
文摘BACKGROUND Autoimmune encephalitis(AE)is a rare and recently described neuroinflammatory disease associated with specific autoantibodies.Anti-leucine-rich glioma inactivated 1(anti-LGI1)encephalitis is a rare but treatable type of AE discovered in recent years.Alzheimer’s disease(AD)is a degenerative brain disease and the most common cause of dementia.AD may undergo a series of pathological physiological changes in brain tissue 20 years before the onset of typical symptoms.The stage of mild cognitive impairment(MCI)that occurs during this process,known as MCI due to AD,is the earliest stage with clinical symptoms.MCI is typically categorized into two subtypes:Amnestic MCI(aMCI)and non-aMCI.CASE SUMMARY This report describes a patient with rapid cognitive impairment,diagnosed with anti-LGI1 antibody-mediated AE and aMCI,and treated at Peking University Shenzhen Hospital in March 2023.The patient was hospitalized with acute memory decline for more than 3 months.Both the cerebrospinal fluid and serum were positive for anti-LGI1 antibodies,biomarkers of AD coexisting in the patient’s cerebrospinal fluid.Following combination treatment with immunoglobulin therapy and glucocorticoid,plus inhibition of acetylcholinesterase,the patient’s cognitive function significantly improved.Throughout the 3-month follow-up period,a sustained improvement in cognitive function was observed.The results of serum anti-LGI1 antibody were negative.CONCLUSION This case has raised awareness of the possible interaction between AE and early AD(including MCI due to AD),and alerted clinicians to the possibility of concurrent rare and common diseases in patients presenting with cognitive impairment.
基金supported by the Swedish Research Council(2017-01286,2020-01840)the Swedish state under the agreement between the Swedish government and the county councils(ALF-agreement)(ALFGBG721581)+2 种基金the Gustaf V 80-years fund(FAI-2018-0466)the IngaBritt and Arne Lundberg Foundation(LU2017-0076)the Novo Nordisk Foundation(26844).
文摘Membrane-initiated estrogen receptorα(mERα)signaling has been shown to affect bone mass in murine models.However,it remains unknown which cell types mediate the mERα-dependent effects on bone.In this study,we generated a novel mouse model with a conditional C451A mutation in Esr1,which enables selective knockout of the palmitoylation site essential for the membrane localization of ERα(C451A^(f/f)).First,we used Runx2-Cre mice to generate Runx2-C451A^(f/f)mice with conditional inactivation of mERαsignaling in Runx2-expressing osteoblast lineage cells.No significant changes were observed in body weight,weights of estrogen-responsive organs,or serum concentrations of estradiol between female Runx2-C451A^(f/f)and homozygous C451A^(f/f)littermate controls.High-resolution microcomputed tomography analysis showed a consistent decrease in cortical bone mass in the tibia,femur,and vertebra L5 of Runx2-C451A^(f/f)mice and three-point bending analysis of humerus revealed an impaired mechanical bone strength in Runx2-C451A^(f/f)female mice compared to controls.Additionally,primary osteoblast cultures from mice lacking mERαsignaling showed impaired differentiation compared to controls.
基金supported by National Natural Science Foundation of China(Nos.22325602,22176060)Program of Shanghai Academic/Technology Research Leader(No.23XD1421000)+2 种基金Project supported by Shanghai Municipal Science and Technology Major Project(No.2018SHZDZX03)the Program of Introducing Talents of Discipline to Universities(No.B16017)Science and Technology Commission of Shanghai Municipality(No.20DZ2250400)。
文摘H_(2)O_(2)is an environmentally friendly oxidizing agent with minimal secondary pollution;however,its application has always been constrained by factors such as storage and transportation.In this study,we propose an innovative method for storing and releasing H_(2)O_(2)using hydrogels.Commercial hydrogels(sodium polyacrylate)can undergo swelling and absorb H_(2)O_(2)in aqueous solutions,and the swollen hydrogel can continuously release H_(2)O_(2)under osmotic pressure.And the characteristics of osmotic pressure drive ensure the recyclability of hydrogel for H_(2)O_(2)storage.Experimental results demonstrate that H_(2)O_(2)can stably exist within the hydrogel for an extended period,and this strategy helps to avoid explosion the risk and potential environmental hazards during the transportation of H_(2)O_(2).Finally,experiments confirm that the hydrogel controlled sustained release of H_(2)O_(2)is effective in both Fenton reactions and the process of bacterial inactivation.This work introduces new ideas for the storage of H_(2)O_(2),and the sustained release of H_(2)O_(2)may have significant implications in the fields of healthcare,environmental science,catalysis,and beyond.
基金supported by the Key Research and Development Program,Ministry of Science and Technology of the People’s Republic of China(Nos.2023YFC2606500,2023YFE0206500).
文摘Coronaviruses are single-stranded,positive-sense RNA enveloped viruses that have posed a significant threat to human health over the past few decades,particularly severe acute respiratory syndrome coronavirus(SARS-CoV),Middle East respiratory syndrome coronavirus(MERS-CoV),and SARS-CoV-2.These viruses have caused widespread infections and fatalities,with profound impacts on global economies,social life,and public health systems.Due to their broad host range in natural settings and the consequent high potential for zoonotic spillover events,a thorough investigation of the common viral mechanisms and the identification of druggable targets for pan-coronavirus antiviral development are of utmost importance.
基金Project(21271071)supported by the National Natural Science Foundation of ChinaProject(21306041)supported by the National Natural Science Young Foundation of China
文摘ZnO/Znml2O4 nanocomposites with heteronanostructures were successfully prepared by co-precipitation method. The as-prepared samples were characterized by HRTEM, TEM, XRD, BET, TG-DTA, and UV-Vis spectra techniques. The photoeatalytic activities of the as-prepared samples were evaluated by the photocatalytic degradation of methyl orange and inactivation of Escherichia coli in suspension under the irradiation of the simulated sunlight. The effects of compositions, calcination temperatures, concentration ofphotocatalysts and light source on the photocatalytic activities were systematically studied. The results show that when the concentration of ZnO/ZnA1204 photocatalyst with the starting Zn to Al molar ratio of 1：1.5 calcined at 600 ℃ is 1.0 g/L, the maximum photocatalytic degradation rate of 98.5% can be obtained in 50 min under the irradiation of the simulated sunlight. Under the same conditions, an inactivation rate of 99.8% for E.coli is achieved in 60 min.
文摘β-N-Acetyl-D-glucosaminidase （NAGase, EC.3.2.1.52） is chitinolytic enzymes and disintegrate dimmer and trimer a composition of oligomers of N-acetyl-β-D-glucosamine （NAG） into monomer. Prawn （P. vannamei） NAGase is involved in digestion and molting processes. Some pollutants in seawater affect the enzyme activity causing loss of the biological function of the enzyme, which affects the exuviating shell and threatens the survival of the animal. The effect of formaldehyde on prawn （P. vannamei） β-N-acetyl-D-glucosaminidase activity for the hydrolysis of pNP-NAG has been studied. The results show that formaldehyde, at appropriate concentrations, can lead to reversible inactivation of the enzyme, and the IC50 is estimated to be 1.05mol· L^-1. The inactivation mechanism obtained from Lineweaver-Burk plots shows that the inactivation of the enzyme by formaldehyde belongs to the competitive type. The inactivation kinetics of the enzyme by formaldehyde has been studied using the progress-of-substrate-reaction method described by Tsou, and the rate constants have been determined. The results show that k＋0 is much larger than k-0, indicating the free enzyme molecule is fragile in the formaldehyde solution.
