Glucosinolates(GLS) contribute to the unique flavour, nutrition, and plant defence of the Cruciferous vegetables. Understanding the GLS changes through postharvest processing is essential for defined preservation. In ...Glucosinolates(GLS) contribute to the unique flavour, nutrition, and plant defence of the Cruciferous vegetables. Understanding the GLS changes through postharvest processing is essential for defined preservation. In this study, four different fresh-cut types, whole flower(W),floret(F), quarterly cut floret(QF) and shredded floret(FS) of broccoli, were stored for 0, 1, 2 and 3 day(s) to explore GLS responses to postharvest treatments. As a result, seven GLS were identified, mainly including glucoraphanin(RAA), neoglucobrassicin(NEO), and glucobrassicin(GBC)and accounting for 52.69%, 20.12% and 14.99% of the total GLS(21.92 ± 0.48) μmol · g ^(-1 )DW, respectively. FS had the sharpest decrease in GLS after three days of storage(6.55 ± 0.37) μmol · g-1DW, while QF had the least(10.16 ± 0.33) μmol · g ^(-1 )DW. All GLS components decreased over storage, except for 4-methoxyglucobrassicin(4 ME) in FS and QF, suggesting its key role in serious wound defence. The results suggested certain postharvest approaches influenced the flavour and nutrition of broccoli.展开更多
Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathwa...Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathways may compete for substrates.However,the mechanism regulating this potential competition remains unclear.Here,we identified GhMYB1a,an R2R3-MYB transcription factor involved in the regulation of anthocyanin and flavonol accumulation in gerbera(Gerbera hybrida).GhMYB1a shares high sequence similarity with that of other characterized regulators of flavonol biosynthesis.In addition,GhMYB1a is also phylogenetically grouped with these proteins.The overexpression of GhMYB1a in gerbera and tobacco(Nicotiana tabacum)resulted in decreased anthocyanin accumulation and increased accumulation of flavonols by upregulating the structural genes involved in flavonol biosynthesis.We further found that GhMYB1a functions as a homodimer instead of interacting with basic helix-loop-helix cofactors.These results suggest that GhMYB1a is involved in regulating the anthocyanin and flavonol metabolic pathways through precise regulation of gene expression.The functional characterization of GhMYB1a provides insight into the biosynthesis and regulation of flavonols and anthocyanins.展开更多
Soft-shelled turtle, Pelodiscus sinensis is important aquatic species in China, and searching for alternatives protein resources to fish meal (FM)-based feeds in feed has become urgent and important for its sustainabi...Soft-shelled turtle, Pelodiscus sinensis is important aquatic species in China, and searching for alternatives protein resources to fish meal (FM)-based feeds in feed has become urgent and important for its sustainability development. The present study was conducted to assess the effects of dietary soy protein concentrate (SPC) on growth, digestive enzymes and target of rapamycin (TOR) signaling pathway of juvenile P. sinensis (4.56 ± 0.09 g). SPC was applied to replace FM protein at 0%, 15%, 30% and 60% (designated as T0, T15, T30 and T60, respectively), and each diet was fed to triplicate groups. The results showed that there was no significant difference in growth performance and feed utilization except of the turtles fed with T60 diet, of which showed poorer daily weight gain and feed conversion rate. The pepsin/trypsin and Na+-K+ ATP-ase activities decreased dramatically when SPC level increased, and lipase activities in liver and intestinal tract also showed decline tendency. However, amylase activities were unaffected. No significant differences were observed in TOR, S6K1 and 4E-BP1 genes mRNA expression level of TOR signaling pathway among the treatments. However, the relative phosphorylated level of these proteins decreased significantly when SPC level increased. The present study indicated that high SPC substitution level would suppress digestive enzymes and TOR signaling pathway proteins phosphorylated level and eventually result in growth reduction of P. sinensis.展开更多
Electron transport layers(ETLs)in perovskite solar cells(PSCs)are a key factor to determine the photovoltaic performance.Herein,we demonstrate preparation of Zn O/ZnS core-shell composites through directly synthesizin...Electron transport layers(ETLs)in perovskite solar cells(PSCs)are a key factor to determine the photovoltaic performance.Herein,we demonstrate preparation of Zn O/ZnS core-shell composites through directly synthesizing ZnS on the ZnO nanoparticles in solution.We confirmed the formation of ZnO/ZnS core-shell composites by the uses of X-ray diffraction patterns and the Fourier transform infrared spectroscopy.ZnO/ZnS composites exhibit much homogeneous surface morphology as compared with the bare Zn O as revealed in the scanning electronic microscopy.Moreover,the upper shift of conduction band level upon composition of the Zn O/Zn S film results in a better alignment of energy level,which facilitates cascade charge extraction and thus improves the current density of perovskite solar cell.The shift of conduction band also improves the voltage of the PSCs.The photoluminescence(PL)spectroscopies measured in both steady and transient states were carried out to characterize the charge extraction at the interface between CH_3NH_3PbI_3and the electron transport layers of either ZnO or ZnO/ZnS composite.The ZnO/ZnS composite can more efficiently quench the PL signal of perovskite absorber than bare Zn O resulting in enhanced photocurrent generation in PSCs.展开更多
The research aimed to develop and validate an ion chromatography method for the simultaneous analysis of Cr(Ⅲ) and Cr(Ⅵ)from pumpkin. A new analytical method based on ion chromatography techniques was developed by t...The research aimed to develop and validate an ion chromatography method for the simultaneous analysis of Cr(Ⅲ) and Cr(Ⅵ)from pumpkin. A new analytical method based on ion chromatography techniques was developed by the Cr(Ⅲ) pre-column derivatization and Cr(Ⅵ) post-column derivatization. The ion chromatography condition was optimized and the detection sensitivity was improved. Cr(Ⅲ) and Cr(Ⅵ) were determined by 365 and 530 nm,respectively. The temperature of water bath,the heating time for pre-column derivatization,and the flow rate of post-column derivative liquid were screened on the basis of single factor experiment,the effects of various factors were determined by the method of L16( 43) orthogonal experiment design. Considering the results of orthogonal experiments and the variation tendency of peak area under different factors,the optimum derivatization conditions were chose as follows: the flow rate of post-column derivative liquid is0. 5 m L/min,the temperature of water bath for pre-column derivatization is 100 ℃ and the heating time is 5 min. The conditions were optimized by means of orthogonal experiments under the p H of leacheate ranged from 6. 5 to 6. 8 and the I-concentration of 5 mmol/L. Under optimized derivatization conditions,the detection limits for Cr(Ⅲ) and Cr(Ⅵ) were 0. 17 and 0. 019 mg,respectively. And the average recoveries of Cr(Ⅲ) in pumpkin were in the range of 82%-85%. Results indicated that pumpkin does not contain Cr(Ⅵ) according to this ion chromatography method of simultaneously determination for Cr(Ⅲ) and Cr(Ⅵ).展开更多
Positive-sense single-stranded RNA(+ssRNA)viruses,the most abundant viruses of eukaryotes in nature,require the synthesis of negative-sense RNA(-RNA)using their genomic(positive-sense)RNA(+RNA)as a template for replic...Positive-sense single-stranded RNA(+ssRNA)viruses,the most abundant viruses of eukaryotes in nature,require the synthesis of negative-sense RNA(-RNA)using their genomic(positive-sense)RNA(+RNA)as a template for replication.Based on current evidence,viral proteins are translated via viral+RNAs,whereas-RNA is considered to be a viral replication intermediate without coding capacity.Here,we report that plant and animal+ssRNA viruses contain small open reading frames(ORFs)in their-RNA(reverse ORFs[rORFs]).Using turnip mosaic virus(TuMV)as a model for plant+ssRNA viruses,we demonstrate that small proteins encoded by rORFs display specific subcellularlocalizations,and confirm the presence of rORF2 in infected cells through mass spectrometry analysis.The protein encoded by TuMV rORF2 forms punctuate granules that are localized in the perinuclear region and co-localized with viral replication complexes.The rORF2 protein can directly interact with the viral RNA-dependent RNA polymerase,and mutation of rORF2 completely abolishes virus infection,whereas ectopic expression of rORF2 rescues the mutant virus.Furthermore,we show that several rORFs in the-RNA of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)have the ability to suppress type l interferon production and facilitate the infection of ve-sicular stomatitis virus.In addition,we provide evidence that TuMV might utilize internal ribosome entry sites to translate these small rORFs.Taken together,these findings indicate that the-RNA of+ssRNA vi-ruses can also have the coding capacity and that small proteins encoded therein play critical roles in viral infection,revealing a viral proteome larger than previously thought.展开更多
Dear Editor,As one of the most widespread and destructive families of plant viruses,Geminiviridae,named for the twinned icosahedral particles of virus members in the family,poses a serious threat to agricultural produ...Dear Editor,As one of the most widespread and destructive families of plant viruses,Geminiviridae,named for the twinned icosahedral particles of virus members in the family,poses a serious threat to agricultural production worldwide.Transmitted by various homopterans insects such as whiteflies,leafhoppers,aphids,and treehoppers,geminiviruses infect,in addition to wild plants,vegetable,root,and fiber crops,thus causing important losses around the globe(Hanley-Bowdoin et al.,2013;Li et al.,2022).展开更多
Boehmeria nivea(L.)Gaud.is a potential candidate for the remediation of Cd contaminated sites.The present investigation aims to explore Cd tolerance threshold and to quickly identify the role of exogenous organic acid...Boehmeria nivea(L.)Gaud.is a potential candidate for the remediation of Cd contaminated sites.The present investigation aims to explore Cd tolerance threshold and to quickly identify the role of exogenous organic acids in Cd uptake and abiotic metal stress damage.Elevated Cd levels(0–10 mg/L)resulted in an obvious rise in Cd accumulation,ranging from268.0 to 374.4 in root and 25.2 to 41.2 mg/kg dry weight in shoot,respectively.Citric acid at1.5 mmol/L significantly facilitated Cd uptake by 26.7%in root and by 1-fold in shoot,respectively.Cd translocation efficiency from root to shoot was improved by a maximum of66.4%under 3 mmol/L of oxalic acid.Citric acid exhibited more prominent mitigating effect than oxalic acid due to its stronger ligand affinity for chelating with metal and avoiding the toxicity injury of free Cd ions more efficiently.The present work provides a potential strategy for efficient Cd remediation with B.nivea.展开更多
The present study investigated the relationship between N-acyl-homoserine lactone(AHL)-based quorum sensing(QS) and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and ...The present study investigated the relationship between N-acyl-homoserine lactone(AHL)-based quorum sensing(QS) and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1(1.0065 g/mL). The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.展开更多
C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of ...C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of the GZO films on crystalline size were systematically studied. The results showed that the texture coefficient of (002) peak (TC(002)) decreases with increasing crystalline size. The Hall mobility m was reciprocal to electron effective mass and the fitted relaxation time s was 0.11±0.01 ms. With the increase of average crystalline size,the resistivity increased slightly,which is caused by the competition of (002) and(101) plane,introducing in some defects and leading to carrier density reduction. The optical band gap was in the range from 3.454 to 3.319 eV with increasing crystalline size from 26.96 to 30.88 nm,showing a negative relationship. The dependence of optical band gap (Eopg) on the crystalline size(R) can be qualitatively explained by a quantum confinement effect. The relationship between Eopg and R of GZO films suggests that tuning up optical properties for desired applications can be achieved by controlling the crystalline size.展开更多
Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically...Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη,an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway,in the nucleus through directing it to the plasma membrane.However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear.Here,we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein,and that C4 shuttling is accompanied by nuclear export of NbSKTI.TLCYnV C4 is phosphorylated by NbSKη in the nucleus,which promotes myristoylation of the viral protein.Myristoylation of phosphorylated C4 favors its interaction with exportin-α(XPO I);which in turn facilitates nuclear export of the C4/NbSKTI complex. Supporting this model,chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4,and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention ofrC4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus,restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling.Taken together,our results suggest that nucleocytoplasmic shuttling of TLCYnV C4,enabled by phosphorylation by NbSKη,myristoylation,and interaction with exportin-α is critical for its function as a pathogenicity factor.展开更多
As an environmentally friendly perovskite material with low bandgap,Tin (Sn)-based perovskite has drawn much attention.A simple and effective method for fabricating high-quality Sn-Pb binary perovskite film is highly ...As an environmentally friendly perovskite material with low bandgap,Tin (Sn)-based perovskite has drawn much attention.A simple and effective method for fabricating high-quality Sn-Pb binary perovskite film is highly desired.Here,with methylammonium chloride (MACI) post-treatment to assist vertical recrystallization,we fabricated high quality FA0.75Cs0.25Pb0sSn0.5l3 perovskite film via one-step processing method.This recrystallization method was first used in Sn-based perovskite.The obtained film consists of vertically aligned grains with high crystallinity,which contributes to a power conversion efficiency (PCE) of 14.03% in corresponding perovskite solar cell (PVSC).The cells maintained 80% of their initial PCEs after being stored for 30 d in glove-box.This simple,effective method provides an easy way to fabricate high performance Sn-Pb binary PVSC.展开更多
Betasatellites(DNAβ)are circular ssDNA molecules that are associated with monopartite geminiviruses and exert a positive effect on the viral infection.Betasatellites encode one protein,namedβC1,on the complementary ...Betasatellites(DNAβ)are circular ssDNA molecules that are associated with monopartite geminiviruses and exert a positive effect on the viral infection.Betasatellites encode one protein,namedβC1,on the complementary strand;βC1 functions as a pathogenicity factor and RNA silencing suppressor.In this report,we describe the identification of another betasatellite-encoded protein,βV1,which also contributes to symptom development.TheβV1 open reading frame can be found on the viral strand of approximately 40%of reported betasatellite sequences,and is conserved in position and sequence.The presence of theβV1 transcript was observed in plants infected with Tomato yellow leaf curl China virus(TYLCCNV)along with its associated betasatellite Tomato yellow leaf curl China betasatellite(TYLCCNB).Mutant viruses unable to produceβV1 showed reduced virulence and decreased viral load.Ectopic expression of the TYLCCNB-βV1 gene in Nicotiana benthamiana plants from a PVX-based vector resulted in leaf mosaic and chlorosis.We further demonstrated that theβV1 protein could elicit hypersensitive response(HR)-type cell death in N.benthamiana leaves.Our results uncover a novel betasatellite-encoded protein that contributes to the virus infection,and this discover gives us a more complete view of the plant-geminivirus interaction landscape.展开更多
In this study,kiwi juice was fermented with acid-resistant and bile-resistant probiotics to screen out lactic acid bacteria that can lower cholesterol and were suitable for kiwi fermentation.A non-linear fitting equat...In this study,kiwi juice was fermented with acid-resistant and bile-resistant probiotics to screen out lactic acid bacteria that can lower cholesterol and were suitable for kiwi fermentation.A non-linear fitting equation was used to establish a kinetic model of probiotics fermenting kiwi juice(R^(2)>0.90),and then a fermented juice with special effects of lowering fat was prepared.We have studied the lipid-lowering effect of fermented fruit juice through in vivo validation experiments in mice,and determined the lipid-lowering effect of fermented fruit juice according to the mouse serum indicators and the distribution of intestinal flora.The results suggested that the juice fermented with Bifidobacterium bifidum 6169 and Lactobacillus plantarum 21805 were more effective in cholesterol degradation,and the cholesterol degradation rates were 67.57%and 64.22%,respectively.The number of viable bacteria after fermentation was significantly higher than other groups(p<0.05),and the sensory score was also higher.In addition,the serum indicators were significantly ameliorated and the number of beneficial microorganisms in the intestinal flora increased after the high-fat mice were treated with fermented kiwifruit juice.The research indicates that the fermented products have a regulatory effect on cholesterol levels in mice with hyperlipidemia.展开更多
Background:High sodium intake is an important risk factor for hypertension and cardiovascular disease.However,the association between gut microbiota composition and metabolomic profiles with dietary sodium intake and ...Background:High sodium intake is an important risk factor for hypertension and cardiovascular disease.However,the association between gut microbiota composition and metabolomic profiles with dietary sodium intake and blood pressure(BP)is not well-understood.The metabolome,microbiome,and dietary salt intervention(MetaSalt)study aimed to investigate microbial and metabolomic profiles related to dietary sodium intake and BP regulation.Methods:This family-based intervention study was conducted in four communities across three provinces in rural northern China in 2019.Probands with untreated prehypertension or stage-1 hypertension were identified through community-based BP screening,and family members including siblings,offspring,spouses,and parents were subsequently included.All participants participated in a 3-day baseline examination with usual diet consumption,followed by a 10-day low-salt diet(3 g/d of salt or 51.3 mmol/d of sodium)and a 10-day high-salt diet(18 g/d of salt or 307.8 mmol/d of sodium).Differences in mean BP levels were compared according to the intervention phases using a paired Student’s t-test.Results:A total of 528 participants were included in this study,with a mean age of 48.1 years,36.7%of whom were male,76.8%had a middle school(69.7%)or higher(7.1%)diploma,23.4%had a history of smoking,and 24.4%were current drinkers.The mean arterial pressure at baseline was 97.2±10.5 mm Hg for all participants,and significantly decreased during the low-salt intervention(93.8±9.3,P<0.0001)and subsequently increased during the high-salt intervention(96.4±10.0,P<0.0001).Conclusions:Our dietary salt intervention study has successfully recruited participants and will facilitate to evaluate the effects of gut microbiota and metabolites on BP regulation in response to sodium burden,which will provide important evidence for investigating the underlying mechanisms in the development of hypertension and subsequent cardiovascular diseases.Trial registration:The study was registered in the Chinese Clinical Trial Registry database(ChiCTR1900025171).展开更多
基金supported by the Collaborative Innovation Center of the Beijing Academy of Agriculture and Forestry Sciences(Grant No.KJCX201915)the Youth Scientific Research Funds of Beijing Academy of Agriculture and Forestry Sciences(Grant No.QNJJ201914)the Innovation and Capacity-building Project of Beijing Academy of Agriculture and Forestry Sciences(Grant No.KJCX20200213).
文摘Glucosinolates(GLS) contribute to the unique flavour, nutrition, and plant defence of the Cruciferous vegetables. Understanding the GLS changes through postharvest processing is essential for defined preservation. In this study, four different fresh-cut types, whole flower(W),floret(F), quarterly cut floret(QF) and shredded floret(FS) of broccoli, were stored for 0, 1, 2 and 3 day(s) to explore GLS responses to postharvest treatments. As a result, seven GLS were identified, mainly including glucoraphanin(RAA), neoglucobrassicin(NEO), and glucobrassicin(GBC)and accounting for 52.69%, 20.12% and 14.99% of the total GLS(21.92 ± 0.48) μmol · g ^(-1 )DW, respectively. FS had the sharpest decrease in GLS after three days of storage(6.55 ± 0.37) μmol · g-1DW, while QF had the least(10.16 ± 0.33) μmol · g ^(-1 )DW. All GLS components decreased over storage, except for 4-methoxyglucobrassicin(4 ME) in FS and QF, suggesting its key role in serious wound defence. The results suggested certain postharvest approaches influenced the flavour and nutrition of broccoli.
基金supported by the Foundation of Guangzhou Science and Technology Project(201904010127 to C.Z.)National Natural Science Foundation of China(Grants 31372099,31601784,and 31672188 to X.W.,L.L.and Y.W.,respectively)+1 种基金Open Project Foundation of South China Normal University(2018KF0202 to C.Z.)Specialized Research Fund for Graduate Students at South China Normal University(2014ssxm26).
文摘Anthocyanins and flavonols have vital roles in flower coloration,plant development,and defense.Because anthocyanins and flavonols share the same subcellular localization and common biosynthetic substrates,these pathways may compete for substrates.However,the mechanism regulating this potential competition remains unclear.Here,we identified GhMYB1a,an R2R3-MYB transcription factor involved in the regulation of anthocyanin and flavonol accumulation in gerbera(Gerbera hybrida).GhMYB1a shares high sequence similarity with that of other characterized regulators of flavonol biosynthesis.In addition,GhMYB1a is also phylogenetically grouped with these proteins.The overexpression of GhMYB1a in gerbera and tobacco(Nicotiana tabacum)resulted in decreased anthocyanin accumulation and increased accumulation of flavonols by upregulating the structural genes involved in flavonol biosynthesis.We further found that GhMYB1a functions as a homodimer instead of interacting with basic helix-loop-helix cofactors.These results suggest that GhMYB1a is involved in regulating the anthocyanin and flavonol metabolic pathways through precise regulation of gene expression.The functional characterization of GhMYB1a provides insight into the biosynthesis and regulation of flavonols and anthocyanins.
文摘Soft-shelled turtle, Pelodiscus sinensis is important aquatic species in China, and searching for alternatives protein resources to fish meal (FM)-based feeds in feed has become urgent and important for its sustainability development. The present study was conducted to assess the effects of dietary soy protein concentrate (SPC) on growth, digestive enzymes and target of rapamycin (TOR) signaling pathway of juvenile P. sinensis (4.56 ± 0.09 g). SPC was applied to replace FM protein at 0%, 15%, 30% and 60% (designated as T0, T15, T30 and T60, respectively), and each diet was fed to triplicate groups. The results showed that there was no significant difference in growth performance and feed utilization except of the turtles fed with T60 diet, of which showed poorer daily weight gain and feed conversion rate. The pepsin/trypsin and Na+-K+ ATP-ase activities decreased dramatically when SPC level increased, and lipase activities in liver and intestinal tract also showed decline tendency. However, amylase activities were unaffected. No significant differences were observed in TOR, S6K1 and 4E-BP1 genes mRNA expression level of TOR signaling pathway among the treatments. However, the relative phosphorylated level of these proteins decreased significantly when SPC level increased. The present study indicated that high SPC substitution level would suppress digestive enzymes and TOR signaling pathway proteins phosphorylated level and eventually result in growth reduction of P. sinensis.
基金supported by the Natural Science Foundation of China (no. 11574111)the Natural Science Foundation of Jilin Province (no. 20160101303JC)+2 种基金supported by the 973 Program (2014CB643506)the Natural Science Foundation of China (no. 21221063)the Program for Chang Jiang Scholars and Innovative Research Team in University (no. IRT101713018)
文摘Electron transport layers(ETLs)in perovskite solar cells(PSCs)are a key factor to determine the photovoltaic performance.Herein,we demonstrate preparation of Zn O/ZnS core-shell composites through directly synthesizing ZnS on the ZnO nanoparticles in solution.We confirmed the formation of ZnO/ZnS core-shell composites by the uses of X-ray diffraction patterns and the Fourier transform infrared spectroscopy.ZnO/ZnS composites exhibit much homogeneous surface morphology as compared with the bare Zn O as revealed in the scanning electronic microscopy.Moreover,the upper shift of conduction band level upon composition of the Zn O/Zn S film results in a better alignment of energy level,which facilitates cascade charge extraction and thus improves the current density of perovskite solar cell.The shift of conduction band also improves the voltage of the PSCs.The photoluminescence(PL)spectroscopies measured in both steady and transient states were carried out to characterize the charge extraction at the interface between CH_3NH_3PbI_3and the electron transport layers of either ZnO or ZnO/ZnS composite.The ZnO/ZnS composite can more efficiently quench the PL signal of perovskite absorber than bare Zn O resulting in enhanced photocurrent generation in PSCs.
基金Supported by Science and Technology Innovation Ability Construction Special Item of Beijing Academy of Agriculture and Forestry Sciences(KJCX20140302,KJCX20140111)
文摘The research aimed to develop and validate an ion chromatography method for the simultaneous analysis of Cr(Ⅲ) and Cr(Ⅵ)from pumpkin. A new analytical method based on ion chromatography techniques was developed by the Cr(Ⅲ) pre-column derivatization and Cr(Ⅵ) post-column derivatization. The ion chromatography condition was optimized and the detection sensitivity was improved. Cr(Ⅲ) and Cr(Ⅵ) were determined by 365 and 530 nm,respectively. The temperature of water bath,the heating time for pre-column derivatization,and the flow rate of post-column derivative liquid were screened on the basis of single factor experiment,the effects of various factors were determined by the method of L16( 43) orthogonal experiment design. Considering the results of orthogonal experiments and the variation tendency of peak area under different factors,the optimum derivatization conditions were chose as follows: the flow rate of post-column derivative liquid is0. 5 m L/min,the temperature of water bath for pre-column derivatization is 100 ℃ and the heating time is 5 min. The conditions were optimized by means of orthogonal experiments under the p H of leacheate ranged from 6. 5 to 6. 8 and the I-concentration of 5 mmol/L. Under optimized derivatization conditions,the detection limits for Cr(Ⅲ) and Cr(Ⅵ) were 0. 17 and 0. 019 mg,respectively. And the average recoveries of Cr(Ⅲ) in pumpkin were in the range of 82%-85%. Results indicated that pumpkin does not contain Cr(Ⅵ) according to this ion chromatography method of simultaneously determination for Cr(Ⅲ) and Cr(Ⅵ).
基金funded by the National Key Research and Development Program of China(2021YFD1400400)to F.L.the National Natural Science Foundation of China(31930089 and 31972244)to X.Z.and F.L.+2 种基金a startup grant for High-level Talents of Fujian Medical University(XRCZX2019019)the Natural Science Foundation of Fujan Province,China(2020J01604)to Q.S.Work in the R.L.-D.lab is partially funded by the ERC-COG grant GemOmics(101044142)to R.L.-D.
文摘Positive-sense single-stranded RNA(+ssRNA)viruses,the most abundant viruses of eukaryotes in nature,require the synthesis of negative-sense RNA(-RNA)using their genomic(positive-sense)RNA(+RNA)as a template for replication.Based on current evidence,viral proteins are translated via viral+RNAs,whereas-RNA is considered to be a viral replication intermediate without coding capacity.Here,we report that plant and animal+ssRNA viruses contain small open reading frames(ORFs)in their-RNA(reverse ORFs[rORFs]).Using turnip mosaic virus(TuMV)as a model for plant+ssRNA viruses,we demonstrate that small proteins encoded by rORFs display specific subcellularlocalizations,and confirm the presence of rORF2 in infected cells through mass spectrometry analysis.The protein encoded by TuMV rORF2 forms punctuate granules that are localized in the perinuclear region and co-localized with viral replication complexes.The rORF2 protein can directly interact with the viral RNA-dependent RNA polymerase,and mutation of rORF2 completely abolishes virus infection,whereas ectopic expression of rORF2 rescues the mutant virus.Furthermore,we show that several rORFs in the-RNA of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)have the ability to suppress type l interferon production and facilitate the infection of ve-sicular stomatitis virus.In addition,we provide evidence that TuMV might utilize internal ribosome entry sites to translate these small rORFs.Taken together,these findings indicate that the-RNA of+ssRNA vi-ruses can also have the coding capacity and that small proteins encoded therein play critical roles in viral infection,revealing a viral proteome larger than previously thought.
基金supported by grants from the National Natural Science Foundation of China(31930092 and 31930089)the National Key Research and Development Program of China(2022YFD1400804).
文摘Dear Editor,As one of the most widespread and destructive families of plant viruses,Geminiviridae,named for the twinned icosahedral particles of virus members in the family,poses a serious threat to agricultural production worldwide.Transmitted by various homopterans insects such as whiteflies,leafhoppers,aphids,and treehoppers,geminiviruses infect,in addition to wild plants,vegetable,root,and fiber crops,thus causing important losses around the globe(Hanley-Bowdoin et al.,2013;Li et al.,2022).
基金supported by the National Natural Science Foundation of China(No.41271332)the Natural Science Foundation of Hunan province(No.11JJ2031)the Science and Technology Planning Project of Hunan Province,China(No.2012SK2021)
文摘Boehmeria nivea(L.)Gaud.is a potential candidate for the remediation of Cd contaminated sites.The present investigation aims to explore Cd tolerance threshold and to quickly identify the role of exogenous organic acids in Cd uptake and abiotic metal stress damage.Elevated Cd levels(0–10 mg/L)resulted in an obvious rise in Cd accumulation,ranging from268.0 to 374.4 in root and 25.2 to 41.2 mg/kg dry weight in shoot,respectively.Citric acid at1.5 mmol/L significantly facilitated Cd uptake by 26.7%in root and by 1-fold in shoot,respectively.Cd translocation efficiency from root to shoot was improved by a maximum of66.4%under 3 mmol/L of oxalic acid.Citric acid exhibited more prominent mitigating effect than oxalic acid due to its stronger ligand affinity for chelating with metal and avoiding the toxicity injury of free Cd ions more efficiently.The present work provides a potential strategy for efficient Cd remediation with B.nivea.
基金supported by the National Natural Science Found of China (No.51078036)
文摘The present study investigated the relationship between N-acyl-homoserine lactone(AHL)-based quorum sensing(QS) and the physico-chemical properties of aerobic granules.Stable mature granules were observed in SBR2 and SBR3 with average diameters of 0.96,and1.49 mm,respectively. The sludge densities of aerobic granules in SBR2 and SBR3 were1.0246,and 1.0201 g/mL,respectively,which were higher than that of flocculent sludge in SBR1(1.0065 g/mL). The results showed that the activity of AHL-based QS in SBR2 and SBR3 amounted to 2.4- and 2.1-fold induction,however,that in SBR1 with flocculent sludge was1.6-fold induction. In addition,the results also showed that the activity of AHL-based QS in the three reactors rose in the feast condition,and then dropped with the consumption of substrate. However,the activity of AHL-based QS in these three reactors recovered again in prolonged starvation. Furthermore,the results showed that the enhancement of AHL-based QS favored the extracellular polymeric substance production of microorganisms in activated sludge. Thus,it could be concluded that aerobic granules showed higher AHL-based QS than flocculent sludge,which resulted from the higher sludge density of aerobic granules than flocculent sludge. AHL-based QS was related to the metabolism energy in the feast condition; however,in prolonged starvation,microorganisms would emit more AHL-like molecules to protect themselves to resist starvation. Moreover,the enhancement of AHL-based QS favored the EPS component productivity of the microorganisms in activated sludge,which contributed to maintain the aerobic granular structure.
基金supported by the National Natural Science Foundation of China (No.51071038)Sichuan Province Science Foundation for Youths (No.2010JQ0002)State Key Laboratory for Mechanical Behavior of Materials,Xi’an Jiaotong University,China (No.20131309)
文摘C-axis oriented Ga-doped ZnO(GZO) films with various thicknesses were deposited on glass substrate by radio frequency(RF) magnetron sputtering. The dependence of crystal structure,electrical,and optical properties of the GZO films on crystalline size were systematically studied. The results showed that the texture coefficient of (002) peak (TC(002)) decreases with increasing crystalline size. The Hall mobility m was reciprocal to electron effective mass and the fitted relaxation time s was 0.11±0.01 ms. With the increase of average crystalline size,the resistivity increased slightly,which is caused by the competition of (002) and(101) plane,introducing in some defects and leading to carrier density reduction. The optical band gap was in the range from 3.454 to 3.319 eV with increasing crystalline size from 26.96 to 30.88 nm,showing a negative relationship. The dependence of optical band gap (Eopg) on the crystalline size(R) can be qualitatively explained by a quantum confinement effect. The relationship between Eopg and R of GZO films suggests that tuning up optical properties for desired applications can be achieved by controlling the crystalline size.
基金grants from the National Natural Science Foundation of China (31720103914 and 31390422).
文摘Many geminivirus C4 proteins induce severe developmental abnormalities in plants.We previously demon- strated that Tomato leaf curl Yunnan virus (TLCYnV)C4 induces plant developmental abnormalities at least partically by decreasing the accumulation of NbSKη,an ortholog of Arabidopsis BIN2 kinase involved in the brassinosteroid signaling pathway,in the nucleus through directing it to the plasma membrane.However, the molecular mechanism by which the membrane-associated C4 modifies the localization of NbSKη in the host cell remains unclear.Here,we show that TLCYnV C4 is a nucleocytoplasmic shuttle protein,and that C4 shuttling is accompanied by nuclear export of NbSKTI.TLCYnV C4 is phosphorylated by NbSKη in the nucleus,which promotes myristoylation of the viral protein.Myristoylation of phosphorylated C4 favors its interaction with exportin-α(XPO I);which in turn facilitates nuclear export of the C4/NbSKTI complex. Supporting this model,chemical inhibition of N-myristoyltransferases or exportin-α enhanced nuclear retention of C4,and mutations of the putative phosphorylation or myristoylation sites in C4 resulted in increased nuclear retention ofrC4 and thus decreased severity of C4-induced developmental abnormalities. The impact of C4 on development is also lessened when a nuclear localization signal or a nuclear export signal is added to its C-terminus,restricting it to a specific cellular niche and therefore impairing nucleocytoplasmic shuttling.Taken together,our results suggest that nucleocytoplasmic shuttling of TLCYnV C4,enabled by phosphorylation by NbSKη,myristoylation,and interaction with exportin-α is critical for its function as a pathogenicity factor.
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.51620105006 and 61721005)Zhejiang Province Science and Technology Plan(No.2018C01047)+1 种基金the International Science and Technology Cooperation Program of China(ISTCP)(Grant No.2016YFE0102900)the Fundamental Research Funds for the Central Universities(No.2019FZA4005).
文摘As an environmentally friendly perovskite material with low bandgap,Tin (Sn)-based perovskite has drawn much attention.A simple and effective method for fabricating high-quality Sn-Pb binary perovskite film is highly desired.Here,with methylammonium chloride (MACI) post-treatment to assist vertical recrystallization,we fabricated high quality FA0.75Cs0.25Pb0sSn0.5l3 perovskite film via one-step processing method.This recrystallization method was first used in Sn-based perovskite.The obtained film consists of vertically aligned grains with high crystallinity,which contributes to a power conversion efficiency (PCE) of 14.03% in corresponding perovskite solar cell (PVSC).The cells maintained 80% of their initial PCEs after being stored for 30 d in glove-box.This simple,effective method provides an easy way to fabricate high performance Sn-Pb binary PVSC.
基金supported by grants from the National Natural Science Foundation of China to Y.Q.W.(31972235)and to X.P.Z.(31720103914)。
文摘Betasatellites(DNAβ)are circular ssDNA molecules that are associated with monopartite geminiviruses and exert a positive effect on the viral infection.Betasatellites encode one protein,namedβC1,on the complementary strand;βC1 functions as a pathogenicity factor and RNA silencing suppressor.In this report,we describe the identification of another betasatellite-encoded protein,βV1,which also contributes to symptom development.TheβV1 open reading frame can be found on the viral strand of approximately 40%of reported betasatellite sequences,and is conserved in position and sequence.The presence of theβV1 transcript was observed in plants infected with Tomato yellow leaf curl China virus(TYLCCNV)along with its associated betasatellite Tomato yellow leaf curl China betasatellite(TYLCCNB).Mutant viruses unable to produceβV1 showed reduced virulence and decreased viral load.Ectopic expression of the TYLCCNB-βV1 gene in Nicotiana benthamiana plants from a PVX-based vector resulted in leaf mosaic and chlorosis.We further demonstrated that theβV1 protein could elicit hypersensitive response(HR)-type cell death in N.benthamiana leaves.Our results uncover a novel betasatellite-encoded protein that contributes to the virus infection,and this discover gives us a more complete view of the plant-geminivirus interaction landscape.
基金supported by grants from the National Key R&D Program of China(2017YFD0400702)the Key Agricultural Science and Technology project of Shaanxi Provincial,China(NYKJ-2019-XA)the Key Research and Development Plan of Shaanxi Province,China(2020NY-096).
文摘In this study,kiwi juice was fermented with acid-resistant and bile-resistant probiotics to screen out lactic acid bacteria that can lower cholesterol and were suitable for kiwi fermentation.A non-linear fitting equation was used to establish a kinetic model of probiotics fermenting kiwi juice(R^(2)>0.90),and then a fermented juice with special effects of lowering fat was prepared.We have studied the lipid-lowering effect of fermented fruit juice through in vivo validation experiments in mice,and determined the lipid-lowering effect of fermented fruit juice according to the mouse serum indicators and the distribution of intestinal flora.The results suggested that the juice fermented with Bifidobacterium bifidum 6169 and Lactobacillus plantarum 21805 were more effective in cholesterol degradation,and the cholesterol degradation rates were 67.57%and 64.22%,respectively.The number of viable bacteria after fermentation was significantly higher than other groups(p<0.05),and the sensory score was also higher.In addition,the serum indicators were significantly ameliorated and the number of beneficial microorganisms in the intestinal flora increased after the high-fat mice were treated with fermented kiwifruit juice.The research indicates that the fermented products have a regulatory effect on cholesterol levels in mice with hyperlipidemia.
基金supported by grants from the Chinese Academy of Medical Sciences Innovation Fund for Medical Sciences(2019-I2M-2-003,2017-I2M-1-004)。
文摘Background:High sodium intake is an important risk factor for hypertension and cardiovascular disease.However,the association between gut microbiota composition and metabolomic profiles with dietary sodium intake and blood pressure(BP)is not well-understood.The metabolome,microbiome,and dietary salt intervention(MetaSalt)study aimed to investigate microbial and metabolomic profiles related to dietary sodium intake and BP regulation.Methods:This family-based intervention study was conducted in four communities across three provinces in rural northern China in 2019.Probands with untreated prehypertension or stage-1 hypertension were identified through community-based BP screening,and family members including siblings,offspring,spouses,and parents were subsequently included.All participants participated in a 3-day baseline examination with usual diet consumption,followed by a 10-day low-salt diet(3 g/d of salt or 51.3 mmol/d of sodium)and a 10-day high-salt diet(18 g/d of salt or 307.8 mmol/d of sodium).Differences in mean BP levels were compared according to the intervention phases using a paired Student’s t-test.Results:A total of 528 participants were included in this study,with a mean age of 48.1 years,36.7%of whom were male,76.8%had a middle school(69.7%)or higher(7.1%)diploma,23.4%had a history of smoking,and 24.4%were current drinkers.The mean arterial pressure at baseline was 97.2±10.5 mm Hg for all participants,and significantly decreased during the low-salt intervention(93.8±9.3,P<0.0001)and subsequently increased during the high-salt intervention(96.4±10.0,P<0.0001).Conclusions:Our dietary salt intervention study has successfully recruited participants and will facilitate to evaluate the effects of gut microbiota and metabolites on BP regulation in response to sodium burden,which will provide important evidence for investigating the underlying mechanisms in the development of hypertension and subsequent cardiovascular diseases.Trial registration:The study was registered in the Chinese Clinical Trial Registry database(ChiCTR1900025171).
