The Yangtze River Economic Belt is the birthplace of the world s rice farming culture,and is the origin of common rice(Oryza sativa L.),wild rice(Oryza Rufipogon Griff.),medicinal rice(Oryza officinalis Wall.ex G.Watt...The Yangtze River Economic Belt is the birthplace of the world s rice farming culture,and is the origin of common rice(Oryza sativa L.),wild rice(Oryza Rufipogon Griff.),medicinal rice(Oryza officinalis Wall.ex G.Watt),and wart-grain rice(Oryza granate Nees et Arn.ex Hook.f.).Rice culture is the main theme of agricultural culture in this economic belt and an outstanding representative of excellent traditional Chinese culture.This study provides an overview of the history of rice cultivation in the belt from the prehistory,post-history and modern progress.It studies the agricultural cultural heritage resources of the whole rice industry chain from the biological genetic resources,world cultural heritage,key cultural relics protection units,national archaeological site parks,movable cultural relics,important agricultural cultural heritage,intangible cultural heritage,China time-honored brands,historical names,traditional markers,tribute culture,archival and documentary heritage.It also analyzes the six main problems in the inheritance and development of rice farming culture,and proposes 8 strategies,including promoting the inheritance and innovative development of excellent traditional Chinese culture through the inheritance of rice farming culture,promoting the Exploration of the Origins of Chinese Civilization Project through rice farming culture,and creating the Yangtze River National Cultural Park with rice farming culture as the main theme.展开更多
The removal of highly toxic arsenic(As)and antimony(Sb)contaminants in water by adsorption presents a great challenge worldwide.Conventional adsorbents exhibit insufficient efficacy for removing pentavalent oxyanions,...The removal of highly toxic arsenic(As)and antimony(Sb)contaminants in water by adsorption presents a great challenge worldwide.Conventional adsorbents exhibit insufficient efficacy for removing pentavalent oxyanions,As(Ⅴ)and Sb(Ⅴ),which are predominant compared with the trivalent species,As(Ⅲ)and Sb(Ⅲ),in surface waters.Here,we synthesized a novel composite adsorbent,amine-functionalized polystyrene resin loaded with nano TiO_(2)(Am PSd-Ti).The mm-scale spheres showed outstanding adsorption capacities for As(Ⅲ),As(Ⅴ),Sb(Ⅲ),and Sb(Ⅴ)at 73.85,153.29,86.80,and 123.71 mg/g,respectively.Am PSd-Ti exhibited selective adsorption for As and Sb in the presence of Cl^(-),NO_(3)^(-),SO_(4)^(2-),and F^(-).As and Sb were adsorbed by the nano-sized TiO_(2)confined in the porous resin via forming innersphere complexes.The protonated amine groups enhanced the adsorption of As(Ⅴ)and Sb(Ⅴ)by electrostatic attraction and hydrogen bonding,which was confirmed by experimental results and molecular dynamics simulations.Fixed-bed column tests showed breakthrough curves with adsorption capacities of1.38 mg/g(6600 BV)and 6.65 mg/g(1260 BV)upon treating real As-contaminated groundwater and Sbcontaminated industrial wastewater.Our study highlights a feasible strategy by incorporating inorganic metal oxides into organic polymers to achieve highly efficient removal of As and Sb in real-world scenarios.展开更多
Controllable synthesis of ultrathin metallene nanosheets and rational design of their spatial arrangement in favor of electrochemical catalysis are critical for their renewable energy applications.Here,a biomimetic de...Controllable synthesis of ultrathin metallene nanosheets and rational design of their spatial arrangement in favor of electrochemical catalysis are critical for their renewable energy applications.Here,a biomimetic design of“Trunk-Branch-Leaf”strategy is proposed to prepare the ultrathin edge-riched Zn-ene“leaves”with a thickness of~2.5 nm,adjacent Zn-ene cross-linked with each other,which are supported by copper nanoneedle“branches”on copper mesh“trunks,”named as Zn-ene/Cu-CM.The resulting superstructure enables the formation of an interconnected network and multiple channels,which can be used as an electrocatalytic CO_(2) reduction reaction(CO_(2)RR)electrode to allow a fast charge and mass transfer as well as a large electrolyte reservoir.By virtue of the distinctive structure,the obtained Zn-ene/Cu-CM electrode exhibits excellent selectivity and activity toward CO production with a maximum Faradaic efficiency of 91.3%and incredible partial current density up to 40 mA cm^(−2),outperforming most of the state-of-the-art Zn-based electrodes for CO_(2) reduction.The phenolphthalein color probe combined with in situ attenuated total reflection-infrared spectroscopy uncovered the formation of the localized pseudo-alkaline microenvironment at the interface of the Zn-ene/Cu-CM electrode.Theoretical calculations confirmed that the localized pH as the origin is responsible for the adsorption of CO_(2) at the interface and the generation of *COOH and *CO intermediates.This study offers valuable insights into developing efficient electrodes through synergistic regulation of reaction microenvironments and active sites,thereby facilitating the electrolysis of practical CO_(2) conversion.展开更多
To improve the resolution and accuracy of Direct Position Determination(DPD),this paper investigates the problem of positioning multiple emitters directly with a single moving Rotating Linear Array(RLA).Firstly,the ge...To improve the resolution and accuracy of Direct Position Determination(DPD),this paper investigates the problem of positioning multiple emitters directly with a single moving Rotating Linear Array(RLA).Firstly,the geometry of the RLA is formulated and analysed.According to its geometry,the intercepted noncoherent signals in multiple interception intervals are modeled.Correspondingly,the Multiple SIgnal Classification(MUSIC)based noncoherent DPD approach is proposed.Secondly,the synchronous coherent pulse signals are individually considered and formulated.And the coherent DPD approach which aims for localizing this special type of signal is presented by stacking all array responses at different interception intervals.Besides,we also derive the constrained Cramer-Rao Lower Bound(CRLB)expression for both noncoherent and coherent DPD with RLA under the constraint that the altitudes of the emitters are known.At last,computer simulations are included to examine the performance of the proposed approach.The results demonstrate that the localization accuracy and resolution of DPD with single moving linear array can be significantly improved by the array rotation.In addition,coherent DPD with RLA further improves the resolution and increases the maximum emitter number that can be localized compared with the noncoherent DPD with RLA.展开更多
Cardiac troponin-I （cTnI） and -T （cTnT） are sensitive and specific markers of myocardial injury. However, the role of increased cTnI and cTnT in percutaneous coronary intervention （PCI）-related myocardial injury...Cardiac troponin-I （cTnI） and -T （cTnT） are sensitive and specific markers of myocardial injury. However, the role of increased cTnI and cTnT in percutaneous coronary intervention （PCI）-related myocardial injury remains controversial. In this prospective, single-center and double-blind study, we aimed to determine the diagnostic and prognostic value of cTnI as well as cTnT （cTns） in PCI-related myocardial injury in a Chinese population. A total of 1,008 patients with stable angina pectoris and non-ST-segment elevation acute coronary syndrome were recruited. The levels of cTnI and cTnT were examined before and after PCI. All patients were followed up for 26± 9 months to observe the incidence of major adverse cardiac events （MACEs）. Our results showed that post- PCI cTnI and/or cTnT levels were increased to more than the 99^th percentile upper reference limit （URL） in 133 （13.2%） patients, among which 22 （2.2%） were more than 5 × 99^th percentile URL. By univariate analysis, an elevation in cTns after PCI was not an independent predictor of increased MACEs, HR 1.35 （P = 0.33, 95% CI： 0.74-2.46）. In conclusion, our data demonstrate that the incidence of PCI-related myocardial injury is not common in a Chinese population and minor elevated cTns levels may not be a sensitive prognostic marker for MACEs.展开更多
Common bile duct(CBD)stones are a frequent problem in Chinese populations,and their incidence is particularly high in certain areas(Wang et al.,2013).In recent years,laparoscopic common bile duct exploration(LCBDE)and...Common bile duct(CBD)stones are a frequent problem in Chinese populations,and their incidence is particularly high in certain areas(Wang et al.,2013).In recent years,laparoscopic common bile duct exploration(LCBDE)and endoscopic retrograde cholangiopancreatography(ERCP)have been the main surgical procedures for CBD stones,although each has different advantages and disadvantages in the treatment of choledocholithiasis(Loor et al.,2017;Zhou et al.,2017).展开更多
Objective To investigate the role of peffusion-weighted magnetic resonance imaging （MRI） in evaluation of cirrhotic fiver. Methods With a 4F catheter, 1% diluted carbon tetrachloride （ 1 ml/kg） was selectively in...Objective To investigate the role of peffusion-weighted magnetic resonance imaging （MRI） in evaluation of cirrhotic fiver. Methods With a 4F catheter, 1% diluted carbon tetrachloride （ 1 ml/kg） was selectively injected into fight or left hepatic artery of 12 dogs fortnightly. The half fiver into which carbon tetrachloride was injected was called as study side （SS）, while the other half fiver without carbon tetrachloride injection was called as study control side （SCS）. Conventional and peffusion-weighted MRI were performed in every 4 weeks. Via a 4F catheter, 5ml gadolinium diethylentriamine pentaaceti acid （Gd-DTPA） dilution was injected into superior mesenteric artery at the 5th scan. The signal intensity-thne curves of SS, SCS, and portal vein were completed in MR workstation. The maximal relative signal increase （ MRSI）, peak time （ tp）, and slope of the curves were measured. Results On conventional MR images, no abnormalities of externality and signal intensity were observed in both SS and SCS of fiver at each stage. The mean tp, MP, SI, and slope of intensity-time curves in normal fiver were 10. 56 seconds, 1.01, and 10. 23 arbitrary unit （au）/s, respectively. Three parameters of curves didn＇t show obvious change in SCS of fiver at every stage. Abnormal perfusion curves occurred in SS of fiver at the 12th week after the 1st injection. The abnormality of perfusion curve in SS was more and more serious as the times of injection increased. The mean tp, IVlRSI, and slope intensity-time curves in SS of fiver were 19.45 seconds, 0. 43, and 3. 60 au/s respectively at the 24th week. Conclusion Perfusion-weighted imaging can potentially provide information about portal peffusion of hepatic parenchyma, and to some degree, reflect the severity of cirrhosis.展开更多
The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy （SEM） in-situ observation. The results indicate...The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy （SEM） in-situ observation. The results indicated that the fatigue crack growth threshold △Kth of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750℃ was determined as 12.89 MPa.m^1/2 and 8.69 MPa.m^1/2, respectively. The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored. At the same time, the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.展开更多
Metformin may reduce food intake and body weight, but the anorexigenic effects of metformin are still poorly understood. In this study, Sprague-Dawley rats were administered a single intracere- broventricular dose of ...Metformin may reduce food intake and body weight, but the anorexigenic effects of metformin are still poorly understood. In this study, Sprague-Dawley rats were administered a single intracere- broventricular dose of metformin and compound C, in a broader attempt to investigate the regula- tory effects of metformin on food intake and to explore the possible mechanism. Results showed that central administration of metformin significantly reduced food intake and body weight gain, par- ticularly after 4 hours. A reduction of neuropeptide Y expression and induction of AMP-activated protein kinase phosphorylation in the hypothalamus were also observed 4 hours after metformin administration, which could be reversed by compound C, a commonly-used antagonist of AMP-activated protein kinase. Furthermore, metformin also improved lipid metabolism by reducing plasma low-density lipoprotein. Our findings suggest that under normal physiological conditions, central regulation of appetite by metformin is related to a decrease in neuropeptide Y gene expres- sion, and that the activation of AMP-activated protein kinase may simply be a response to the anorexigenic effect of metformin.展开更多
Growth differentiation factor 11 （GDF11） is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the re...Growth differentiation factor 11 （GDF11） is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the relationship between serum GDF11 level, bone mass, and bone turnover markers in postmenopausal Chinese women. Serum GDF11 level, bone turnover biochemical markers, and bone mineral density （BMD） were determined in 169 postmenopausal Chinese women （47-78 years old）. GDF11 serum levels increased with aging. There were negative correlations between GDF11 and BMD at the various skeletal sites. After adjusting for age and body mass index （BMI）, the correlations remained statistically significant. In the multiple linear stepwise regression analysis, age or years since menopause, BMI, GDF11, and estradiol were independent predictors of BMD. A significant negative correlation between GDF11 and bone alkaline phosphatase （BAP） was identified and remained significant after adjusting for age and BMI. No significant correlation was noted between cross-linked N-telopeptides of type I collagen （NTX） and GDF11. In conclusion, GDF11 is an independent negative predictor of BMD and correlates with a biomarker of bone formation, BAP, in postmenopausal Chinese women. GDF11 potentially exerts a negative effect on bone mass by regulating bone formation.展开更多
Rural landscape is not only a natural landscape,but also a cultural landscape.The improvement of rural environment in Lushi County is carried out under the background of“Building Beautiful Villages”.Through the plan...Rural landscape is not only a natural landscape,but also a cultural landscape.The improvement of rural environment in Lushi County is carried out under the background of“Building Beautiful Villages”.Through the plan of environmental improvement,the appearance of villages in rural areas will be significantly improved,and the gap between urban and rural areas will be shortened.This research addresses the problems of scarce water resources,imperfect rainwater collection facilities,and increased environmental pollution in rural areas,and explores a flexible,effective,and integrated landscape ecological water treatment system that integrates with natural ecosystems.The practice has shown that the flexible combination of different technical measures according to local conditions and the construction of ecological water self-circulation and self-purification systems can reduce maintenance costs and achieve sustainable landscape.The virtuous cycle of the revetment’s micro-ecology greatly improves the environmental carrying capacity of the landscape.Reasonable water management system is more flexible in dealing with unexpected problems.The thesis proposes landscape design strategies for water circulation and water purification in rural areas,and applies them to actual design cases.It attempts to introduce a combined treatment system to achieve a more diverse landscape concept and further explore the healthy and sustainable development of rural water environment.展开更多
Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong Province.This study assessed the content and dist...Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong Province.This study assessed the content and distribution of brominated flame retardants in sediments.The acute toxicity effects of tetrabromobisphenol A(TBBPA)and hexabromocyclododecane(HBCDs)in sediments were evaluated using Caenorhabditis elegans as model organisms.The concentration of TBBPA in sediments ranged from not detected(ND)to 12.59μg/kg andwas mainly distributed in the central area,whichwas affected by the emission of TBBPA from residential and factory.The concentration of HBCDs ranged from ND to 6.31μg/kg,and the diastereoisomer distribution was consistent,showing a trend close to the South China Sea.The composition pattern of HBCDs in the surface sediments from rivers were 41.73%-62.33%,7.89%-25.54%,and 18.76%-40.65%forα-,β-,andγ-HBCD,respectively,and in the sediments from reservoirs were 26.15%-45.52%,7.44%-19.23%,and 47.04%-61.89%forα-,β-,andγ-HBCD,respectively.When the sum of concentrations of TBBPA and HBCD in sediments were above high levels,reactive oxygen species in nematodes significantly increased,resulting in an oxidative stress response.Intestinal permeabilitywas also enhanced,causing intestinal damage.In addition,in terms of this study,TBBPA had a greater impact on biotoxicity compared to HBCDs,and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City,Guangdong Province.This study can complement the pollution database in the study area and provide basic data for pollution control.展开更多
Aerobic anoxygenic phototrophic bacteria(AAPB)repre sent a major group of bacterioplankton assemblages in many water systems and some are assumed to be closely associated with phytoplankton.However,studies on relation...Aerobic anoxygenic phototrophic bacteria(AAPB)repre sent a major group of bacterioplankton assemblages in many water systems and some are assumed to be closely associated with phytoplankton.However,studies on relationships between AAPB and cyanobacterial blooms are in scarcity.The dynamics of the abundance and diversity of AAPB was compared based on pufM gene in Meiliang Bay(featured by cyanobacterial blooms)and East Bay(featured by macrophyte)of Taihu Lake,a shallow subtropical lake in the East China plain.AAPB abundance was not significantly different between the two sites,and they were positively correlated with dissolved organic carbon(DOC)concentration.The ratios of AAPB to total bacteria varied from 3.4%to 11.5%and peaked in winter in both site s.No significant differences of AAPB community compositions were detected between the two sites,but there was a separation between warm seasons(June,August,and October)and cold seasons(December,February,and April).Rhizobiales and Limnohabitans-like pufM sequences were significantly contributors for the difference between two seasons,and specially enriched in cold seasons.Chlorophyll a(Ch1 a)and DOC were the most significant variables influencing the AAPB community structure.Furthermore,Porphyrobacter and Rhodospirillales-like pufM sequences were positively correlated with Ch1 a,indicating potential influence of cyanobacterial blooms on these AAPB taxa.These results suggested that diverse AAPB ecotypes coexisted in Taihu Lake,and their ecological role in carbon cycling in the lake may not be ignored.展开更多
Plant-derived nanovesicles have gained attention given their similarity to mammalian exosomes and advantages such as low cost,sustainability,and tissue targeting.Thus,they hold promise for disease treatment and drug d...Plant-derived nanovesicles have gained attention given their similarity to mammalian exosomes and advantages such as low cost,sustainability,and tissue targeting.Thus,they hold promise for disease treatment and drug delivery.In this study,we proposed a time-efficient method,PEG 8000 combined with sucrose density gradient centrifugation to prepare ginger-derived nanovesicles(GDNVs).Subsequently,curcumin(CUR)was loaded onto GDNV by ultrasonic incubation.The optimum conditions for ginger-derived nanovesicles loaded with curcumin(CG)were ultrasound time of 3 min,a carrier-to-drug ratio(GDNV:CUR)of 1:1.The study achieved a high loading capacity(94.027%±0.094%)and encapsulation efficiency(89.300%±0.344%).Finally,the drugs'in vivo distribution and anti-colitis activity were investigated in mice.CG was primarily distributed in the colon after oral administration.Compared to CUR and GDNV,CG was superior in improving disease activity,colon length,liver and spleen coefficients,myeloperoxidase activity,and biochemical factor levels in ulcerative colitis(UC)mice.In addition,CG plays a protective role against UC by modulating serum metabolite levels and gut flora.In summary,our study demonstrated that GDNV can be used for CUR delivery with enhanced therapeutic potential.展开更多
Elucidating the regulatory mechanisms of environmental factors on seed dormancy and germination will provide guidance for tree regeneration.Toward understanding the coupled effect of light and temperature on dormancy ...Elucidating the regulatory mechanisms of environmental factors on seed dormancy and germination will provide guidance for tree regeneration.Toward understanding the coupled effect of light and temperature on dormancy release and germination of Pinus koraiensis seeds,we set up three light conditions(L200:200μmol m^(-2) s^(-1),L20:20μmol m^(-2) s^(-1),L0:0μm^(-2) s^(-1))and four storage temperatures[T-5:-5°C(50 days),T5:-5°C(50 days)+5°C(50 days),T25:-5°C(50 days)+5°C(50 days)+25°C(50 days),T15:-5°C(50 days)+5°C(50 days)+25°C(50 days)+15°C(50 days)]using imbibed seeds,then quantified phytohormones gibberellic acid(GA_(3))and abscisic acid(ABA)during the stratification.Germination percentage(G_(P)),mean germination time(T_(M)),and germination value(G_(V))under 25/15°C temperature and the three light conditions were then determined.Phytohormone levels and germination performances were significantly affected by light and temperature.No consistent trend was found between the phytohormone levels and G_(P) caused by light levels.Under the three light conditions,ABA concentrations in the embryo and endosperm decreased as storage temperature shifted from T-5 to T25 and increased from T25 to T15;GA_(3) decreased in nearly all four storage temperatures.G_(P) reached 40–60%in T25 storage without light irradiance.In the three light conditions,G_(P) and G_(V) were higher at T5 and T25 than at T-5 and T15;so T5 and T25 are considered as optimum storage temperatures for dormancy release and germination.At optimum temperatures,light(L200,L20)significantly increased the G_(P) and G_(V) compared with the dark(L0).At L200 and L20,significant negative correlations between G_(V) and the ABA concentrations and positive correlations between G_(V) and GA/ABA in the seed embryo were found.Temperature played a more important role in primary dormancy release and germination;light was unnecessary for primary dormancy release.Light facilitated seed germination at optimum temperatures.The dormancy release and germination of P.koraiensis seeds were controlled by a decrease in ABA concentrations or an increase in GA/ABA induced by temperature variations.展开更多
A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of...A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of the compounds.It is worth noting that the2-methyl alkanes in the humic coal samples show an obvious distribution of even carbon predominances rarely reported in the literature.The results show that with the increase of Pr/Ph(pristane/phytane),the even carbon dominance of 2-methyl alkanes is more obvious,while the odd carbon number distribution of 3-methyl alkanes is weakened.As Pr/Ph increases in the humic coal,the relative content of the hopanes increased,while the relative content of 2-methyl alkanes and 3-methyl alkanes increases first and then decreases.展开更多
Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced Stober method and subsequent hydrothermal reaction with copper ions in alkaline condition.The high content of Cu2+as we...Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced Stober method and subsequent hydrothermal reaction with copper ions in alkaline condition.The high content of Cu2+as well as the unique structures of hierarchical copper silicate in the as-prepared catalysts endowed their outstanding catalytic performance.Efficient decarboxylative A3-coupling of a-keto acid,amine and alkyne was realized with the low Fe3 O4@CuSiO3 loading.A range of propargylamines were produced in good to excellent yields under solvent-free condition.Moreover,the catalyst can be easily separated from the final organic product with an external magnet.Also,this kind of catalyst could be recycled up to six times while maintaining its activity.展开更多
Tooth enamel is prone to be attacked by injurious factors,leading to a de/remineralization imbalance.To repair demineralized enamel and prevent pulp inflammation caused by biofilm accumulation,measures are needed to p...Tooth enamel is prone to be attacked by injurious factors,leading to a de/remineralization imbalance.To repair demineralized enamel and prevent pulp inflammation caused by biofilm accumulation,measures are needed to promote remineralization and inhibit bacterial adhesion on the tooth surface.An innovative material,poly(aspartic acid)-polyethylene glycol(PASP-PEG),was designed and synthesized to construct a mineralizing and anti-adhesive surface that could be applied to repair demineralized enamel.A cytotoxicity assay revealed the low cytotoxicity of synthesized PASP-PEG.Adsorption results demonstrated that PASPPEG possesses a high binding affinity to the hydroxyapatite(HA)/tooth surface.In vitro experiments and scanning electron microscopy(SEM)demonstrated a strong capacity of PASP-PEG to induce in situ remineralization and direct the oriented growth of apatite nanocrystals.Energy dispersive X-ray spectroscopy(EDS),X-ray diffraction analysis(XRD)and Vickers hardness tests demonstrated that minerals induced by PASP-PEG were consistent with healthy enamel in Ca/P ratio,crystal form and surface micro-hardness.Contact angle tests and bacterial adhesion experiments demonstrated that PASP-PEG yielded a strong antiadhesive effect.In summary,PASP-PEG could achieve dual effects for enamel repair and anti-adhesion of bacteria,thereby widening its application in enamel repair.展开更多
Commercialization of perovskite solar cells(PSCs) requires the development of high-efficiency devices with none current density-voltage(J-V) hysteresis. Here, electron transport layers(ETLs) with gradual change in wor...Commercialization of perovskite solar cells(PSCs) requires the development of high-efficiency devices with none current density-voltage(J-V) hysteresis. Here, electron transport layers(ETLs) with gradual change in work function(WF) are successfully fabricated and employed as an ideal model to investigate the energy barriers, charge transfer and recombination kinetics at ETL/perovskite interface. The energy barrier for electron injection existing at ETL/perovskite is directly assessed by surface photovoltage microscopy, and the results demonstrate the tunable barriers have significant impact on the J-V hysteresis and performance of PSCs. By work function engineering of ETL, PSCs exhibit PCEs over 21% with negligible hysteresis. These results provide a critical understanding of the origin reason for hysteresis effect in planar PSCs, and clear reveal that the J-V hysteresis can be effectively suppressed by carefully tuning the interface features in PSCs. By extending this strategy to a modified formamidinium-cesium-rubidium(FA-Cs-Rb) perovskite system, the PCEs are further boosted to 24.18%. Moreover, 5 cm × 5 cm perovskite mini-modules are also fabricated with an impressive efficiency of 20.07%, demonstrating compatibility and effectiveness of our strategy on upscaled devices.展开更多
基金Supported by Social Science Foundation of Hubei Province(HBSKJJ20243227)Doctoral Initiation Project of Hubei University of Science and Technology(BK201819).
文摘The Yangtze River Economic Belt is the birthplace of the world s rice farming culture,and is the origin of common rice(Oryza sativa L.),wild rice(Oryza Rufipogon Griff.),medicinal rice(Oryza officinalis Wall.ex G.Watt),and wart-grain rice(Oryza granate Nees et Arn.ex Hook.f.).Rice culture is the main theme of agricultural culture in this economic belt and an outstanding representative of excellent traditional Chinese culture.This study provides an overview of the history of rice cultivation in the belt from the prehistory,post-history and modern progress.It studies the agricultural cultural heritage resources of the whole rice industry chain from the biological genetic resources,world cultural heritage,key cultural relics protection units,national archaeological site parks,movable cultural relics,important agricultural cultural heritage,intangible cultural heritage,China time-honored brands,historical names,traditional markers,tribute culture,archival and documentary heritage.It also analyzes the six main problems in the inheritance and development of rice farming culture,and proposes 8 strategies,including promoting the inheritance and innovative development of excellent traditional Chinese culture through the inheritance of rice farming culture,promoting the Exploration of the Origins of Chinese Civilization Project through rice farming culture,and creating the Yangtze River National Cultural Park with rice farming culture as the main theme.
基金financial support of the National Natural Science Foundation of China(No.42230706)the Outstanding Youth Science Fund(Overseas)of Shandong Provincial Natural Science Foundation(No.2022HWYQ-015)+1 种基金the Taishan Scholars Project Special Fund(No.tsqn202211039)Qilu Youth Talent Program of Shandong University(No.61440082163171)。
文摘The removal of highly toxic arsenic(As)and antimony(Sb)contaminants in water by adsorption presents a great challenge worldwide.Conventional adsorbents exhibit insufficient efficacy for removing pentavalent oxyanions,As(Ⅴ)and Sb(Ⅴ),which are predominant compared with the trivalent species,As(Ⅲ)and Sb(Ⅲ),in surface waters.Here,we synthesized a novel composite adsorbent,amine-functionalized polystyrene resin loaded with nano TiO_(2)(Am PSd-Ti).The mm-scale spheres showed outstanding adsorption capacities for As(Ⅲ),As(Ⅴ),Sb(Ⅲ),and Sb(Ⅴ)at 73.85,153.29,86.80,and 123.71 mg/g,respectively.Am PSd-Ti exhibited selective adsorption for As and Sb in the presence of Cl^(-),NO_(3)^(-),SO_(4)^(2-),and F^(-).As and Sb were adsorbed by the nano-sized TiO_(2)confined in the porous resin via forming innersphere complexes.The protonated amine groups enhanced the adsorption of As(Ⅴ)and Sb(Ⅴ)by electrostatic attraction and hydrogen bonding,which was confirmed by experimental results and molecular dynamics simulations.Fixed-bed column tests showed breakthrough curves with adsorption capacities of1.38 mg/g(6600 BV)and 6.65 mg/g(1260 BV)upon treating real As-contaminated groundwater and Sbcontaminated industrial wastewater.Our study highlights a feasible strategy by incorporating inorganic metal oxides into organic polymers to achieve highly efficient removal of As and Sb in real-world scenarios.
基金supports of the National Natural Science Foundation of China(NSFC)(52021004,52394202)key project of the Joint Fund for Innovation and Development of Chongqing Natural Science Foundation(CSTB2022NSCQ-LZX0013)+1 种基金the National Natural Science Foundation of China(NSFC)(52301232,and 52476056)the Natural Science Foundation of Chongqing Province(2024NSCQ-MSX1109).
文摘Controllable synthesis of ultrathin metallene nanosheets and rational design of their spatial arrangement in favor of electrochemical catalysis are critical for their renewable energy applications.Here,a biomimetic design of“Trunk-Branch-Leaf”strategy is proposed to prepare the ultrathin edge-riched Zn-ene“leaves”with a thickness of~2.5 nm,adjacent Zn-ene cross-linked with each other,which are supported by copper nanoneedle“branches”on copper mesh“trunks,”named as Zn-ene/Cu-CM.The resulting superstructure enables the formation of an interconnected network and multiple channels,which can be used as an electrocatalytic CO_(2) reduction reaction(CO_(2)RR)electrode to allow a fast charge and mass transfer as well as a large electrolyte reservoir.By virtue of the distinctive structure,the obtained Zn-ene/Cu-CM electrode exhibits excellent selectivity and activity toward CO production with a maximum Faradaic efficiency of 91.3%and incredible partial current density up to 40 mA cm^(−2),outperforming most of the state-of-the-art Zn-based electrodes for CO_(2) reduction.The phenolphthalein color probe combined with in situ attenuated total reflection-infrared spectroscopy uncovered the formation of the localized pseudo-alkaline microenvironment at the interface of the Zn-ene/Cu-CM electrode.Theoretical calculations confirmed that the localized pH as the origin is responsible for the adsorption of CO_(2) at the interface and the generation of *COOH and *CO intermediates.This study offers valuable insights into developing efficient electrodes through synergistic regulation of reaction microenvironments and active sites,thereby facilitating the electrolysis of practical CO_(2) conversion.
基金funded by the National Defence Science and Technology Project Fund of China(No.3101140)the Shanghai Aerospace Science and Technology Innovation Fund of China(No.SAST2015028)the Equipment Prophecy Fund of China(No.9140A21040115KG01001).
文摘To improve the resolution and accuracy of Direct Position Determination(DPD),this paper investigates the problem of positioning multiple emitters directly with a single moving Rotating Linear Array(RLA).Firstly,the geometry of the RLA is formulated and analysed.According to its geometry,the intercepted noncoherent signals in multiple interception intervals are modeled.Correspondingly,the Multiple SIgnal Classification(MUSIC)based noncoherent DPD approach is proposed.Secondly,the synchronous coherent pulse signals are individually considered and formulated.And the coherent DPD approach which aims for localizing this special type of signal is presented by stacking all array responses at different interception intervals.Besides,we also derive the constrained Cramer-Rao Lower Bound(CRLB)expression for both noncoherent and coherent DPD with RLA under the constraint that the altitudes of the emitters are known.At last,computer simulations are included to examine the performance of the proposed approach.The results demonstrate that the localization accuracy and resolution of DPD with single moving linear array can be significantly improved by the array rotation.In addition,coherent DPD with RLA further improves the resolution and increases the maximum emitter number that can be localized compared with the noncoherent DPD with RLA.
基金supported by the Health Bureau of Jiangsu Province(No.K201104)the Scientific Support Plan of Jiangsu Province(No.BE2011803)+2 种基金the National Natural Science Foundation of China(No.81170102/H0203)the Priority Academic Program Development of Jiangsu Higher Education Institutions(No.BL2012011)the Fourth Period Project"333"of Jiangsu Province(No.BRA2012207),China
文摘Cardiac troponin-I （cTnI） and -T （cTnT） are sensitive and specific markers of myocardial injury. However, the role of increased cTnI and cTnT in percutaneous coronary intervention （PCI）-related myocardial injury remains controversial. In this prospective, single-center and double-blind study, we aimed to determine the diagnostic and prognostic value of cTnI as well as cTnT （cTns） in PCI-related myocardial injury in a Chinese population. A total of 1,008 patients with stable angina pectoris and non-ST-segment elevation acute coronary syndrome were recruited. The levels of cTnI and cTnT were examined before and after PCI. All patients were followed up for 26± 9 months to observe the incidence of major adverse cardiac events （MACEs）. Our results showed that post- PCI cTnI and/or cTnT levels were increased to more than the 99^th percentile upper reference limit （URL） in 133 （13.2%） patients, among which 22 （2.2%） were more than 5 × 99^th percentile URL. By univariate analysis, an elevation in cTns after PCI was not an independent predictor of increased MACEs, HR 1.35 （P = 0.33, 95% CI： 0.74-2.46）. In conclusion, our data demonstrate that the incidence of PCI-related myocardial injury is not common in a Chinese population and minor elevated cTns levels may not be a sensitive prognostic marker for MACEs.
基金Project supported by the Foundation Project for Medical Science and Technology of Zhejiang Province(Nos.2019ZH022 and 2018KY478)the Zhejiang Province Public Welfare Technology Application Research Project(No.LGF19H180021),China
文摘Common bile duct(CBD)stones are a frequent problem in Chinese populations,and their incidence is particularly high in certain areas(Wang et al.,2013).In recent years,laparoscopic common bile duct exploration(LCBDE)and endoscopic retrograde cholangiopancreatography(ERCP)have been the main surgical procedures for CBD stones,although each has different advantages and disadvantages in the treatment of choledocholithiasis(Loor et al.,2017;Zhou et al.,2017).
文摘Objective To investigate the role of peffusion-weighted magnetic resonance imaging （MRI） in evaluation of cirrhotic fiver. Methods With a 4F catheter, 1% diluted carbon tetrachloride （ 1 ml/kg） was selectively injected into fight or left hepatic artery of 12 dogs fortnightly. The half fiver into which carbon tetrachloride was injected was called as study side （SS）, while the other half fiver without carbon tetrachloride injection was called as study control side （SCS）. Conventional and peffusion-weighted MRI were performed in every 4 weeks. Via a 4F catheter, 5ml gadolinium diethylentriamine pentaaceti acid （Gd-DTPA） dilution was injected into superior mesenteric artery at the 5th scan. The signal intensity-thne curves of SS, SCS, and portal vein were completed in MR workstation. The maximal relative signal increase （ MRSI）, peak time （ tp）, and slope of the curves were measured. Results On conventional MR images, no abnormalities of externality and signal intensity were observed in both SS and SCS of fiver at each stage. The mean tp, MP, SI, and slope of intensity-time curves in normal fiver were 10. 56 seconds, 1.01, and 10. 23 arbitrary unit （au）/s, respectively. Three parameters of curves didn＇t show obvious change in SCS of fiver at every stage. Abnormal perfusion curves occurred in SS of fiver at the 12th week after the 1st injection. The abnormality of perfusion curve in SS was more and more serious as the times of injection increased. The mean tp, IVlRSI, and slope intensity-time curves in SS of fiver were 19.45 seconds, 0. 43, and 3. 60 au/s respectively at the 24th week. Conclusion Perfusion-weighted imaging can potentially provide information about portal peffusion of hepatic parenchyma, and to some degree, reflect the severity of cirrhosis.
基金financially supported by the National Basic Research Program of China (No.2011CB605506)
文摘The purpose of this paper is to estimate the fatigue crack growth threshold of a high-Nb TiAl alloy at the different temperatures based on scanning electron microscopy （SEM） in-situ observation. The results indicated that the fatigue crack growth threshold △Kth of a nearly lamellar high-Nb TiAl alloy with 8% Nb content at room temperature and 750℃ was determined as 12.89 MPa.m^1/2 and 8.69 MPa.m^1/2, respectively. The effect of the elevated temperature on the fatigue crack growth threshold cannot be ignored. At the same time, the early stage of fatigue crack propagation exhibited multicrack initiation and bridge-link behavior.
基金supported by grants from the National Natural Science Foundation of China,No.31171019 and No.31200820the Opening Project of Shanghai Key Laboratory of Brain Functional Genomics and Key Laboratory of Brain Functional Genomics(East China Normal University)of the Ministry of Education
文摘Metformin may reduce food intake and body weight, but the anorexigenic effects of metformin are still poorly understood. In this study, Sprague-Dawley rats were administered a single intracere- broventricular dose of metformin and compound C, in a broader attempt to investigate the regula- tory effects of metformin on food intake and to explore the possible mechanism. Results showed that central administration of metformin significantly reduced food intake and body weight gain, par- ticularly after 4 hours. A reduction of neuropeptide Y expression and induction of AMP-activated protein kinase phosphorylation in the hypothalamus were also observed 4 hours after metformin administration, which could be reversed by compound C, a commonly-used antagonist of AMP-activated protein kinase. Furthermore, metformin also improved lipid metabolism by reducing plasma low-density lipoprotein. Our findings suggest that under normal physiological conditions, central regulation of appetite by metformin is related to a decrease in neuropeptide Y gene expres- sion, and that the activation of AMP-activated protein kinase may simply be a response to the anorexigenic effect of metformin.
基金supported by Grant 81570806 from the National Natural Science Foundation of China
文摘Growth differentiation factor 11 （GDF11） is an important circulating factor that regulates aging. However, the role of GDF11 in bone metabolism remains unclear. The present study was undertaken to investigate the relationship between serum GDF11 level, bone mass, and bone turnover markers in postmenopausal Chinese women. Serum GDF11 level, bone turnover biochemical markers, and bone mineral density （BMD） were determined in 169 postmenopausal Chinese women （47-78 years old）. GDF11 serum levels increased with aging. There were negative correlations between GDF11 and BMD at the various skeletal sites. After adjusting for age and body mass index （BMI）, the correlations remained statistically significant. In the multiple linear stepwise regression analysis, age or years since menopause, BMI, GDF11, and estradiol were independent predictors of BMD. A significant negative correlation between GDF11 and bone alkaline phosphatase （BAP） was identified and remained significant after adjusting for age and BMI. No significant correlation was noted between cross-linked N-telopeptides of type I collagen （NTX） and GDF11. In conclusion, GDF11 is an independent negative predictor of BMD and correlates with a biomarker of bone formation, BAP, in postmenopausal Chinese women. GDF11 potentially exerts a negative effect on bone mass by regulating bone formation.
文摘Rural landscape is not only a natural landscape,but also a cultural landscape.The improvement of rural environment in Lushi County is carried out under the background of“Building Beautiful Villages”.Through the plan of environmental improvement,the appearance of villages in rural areas will be significantly improved,and the gap between urban and rural areas will be shortened.This research addresses the problems of scarce water resources,imperfect rainwater collection facilities,and increased environmental pollution in rural areas,and explores a flexible,effective,and integrated landscape ecological water treatment system that integrates with natural ecosystems.The practice has shown that the flexible combination of different technical measures according to local conditions and the construction of ecological water self-circulation and self-purification systems can reduce maintenance costs and achieve sustainable landscape.The virtuous cycle of the revetment’s micro-ecology greatly improves the environmental carrying capacity of the landscape.Reasonable water management system is more flexible in dealing with unexpected problems.The thesis proposes landscape design strategies for water circulation and water purification in rural areas,and applies them to actual design cases.It attempts to introduce a combined treatment system to achieve a more diverse landscape concept and further explore the healthy and sustainable development of rural water environment.
基金supported by the National Key Research and Development Program of China(Nos.2022YFC3902102 and 2019YFC1803403)the Key Programof National Natural Science Foundation of China(No.41931298).
文摘Sediment is the ultimate sink of environmental pollutants.A total of 128 surface sediment sampleswere collected from8 rivers and 3 reservoirs in Maoming City,Guangdong Province.This study assessed the content and distribution of brominated flame retardants in sediments.The acute toxicity effects of tetrabromobisphenol A(TBBPA)and hexabromocyclododecane(HBCDs)in sediments were evaluated using Caenorhabditis elegans as model organisms.The concentration of TBBPA in sediments ranged from not detected(ND)to 12.59μg/kg andwas mainly distributed in the central area,whichwas affected by the emission of TBBPA from residential and factory.The concentration of HBCDs ranged from ND to 6.31μg/kg,and the diastereoisomer distribution was consistent,showing a trend close to the South China Sea.The composition pattern of HBCDs in the surface sediments from rivers were 41.73%-62.33%,7.89%-25.54%,and 18.76%-40.65%forα-,β-,andγ-HBCD,respectively,and in the sediments from reservoirs were 26.15%-45.52%,7.44%-19.23%,and 47.04%-61.89%forα-,β-,andγ-HBCD,respectively.When the sum of concentrations of TBBPA and HBCD in sediments were above high levels,reactive oxygen species in nematodes significantly increased,resulting in an oxidative stress response.Intestinal permeabilitywas also enhanced,causing intestinal damage.In addition,in terms of this study,TBBPA had a greater impact on biotoxicity compared to HBCDs,and more attention should be paid to the toxic effects of the river ecosystem organisms in Maoming City,Guangdong Province.This study can complement the pollution database in the study area and provide basic data for pollution control.
基金Supported by the National Natural Science Foundation of China(Nos.31971449,31370509,31100363)the CAS-SAFEA International Partnership Program for Creative Research Teams(CN)(No.KZZD-EWTZ-08)the startup funds from Nanjing Institute of Geography and Limnology,Chinese Academy of Sciences(No.NIGLAS2011QD05)。
文摘Aerobic anoxygenic phototrophic bacteria(AAPB)repre sent a major group of bacterioplankton assemblages in many water systems and some are assumed to be closely associated with phytoplankton.However,studies on relationships between AAPB and cyanobacterial blooms are in scarcity.The dynamics of the abundance and diversity of AAPB was compared based on pufM gene in Meiliang Bay(featured by cyanobacterial blooms)and East Bay(featured by macrophyte)of Taihu Lake,a shallow subtropical lake in the East China plain.AAPB abundance was not significantly different between the two sites,and they were positively correlated with dissolved organic carbon(DOC)concentration.The ratios of AAPB to total bacteria varied from 3.4%to 11.5%and peaked in winter in both site s.No significant differences of AAPB community compositions were detected between the two sites,but there was a separation between warm seasons(June,August,and October)and cold seasons(December,February,and April).Rhizobiales and Limnohabitans-like pufM sequences were significantly contributors for the difference between two seasons,and specially enriched in cold seasons.Chlorophyll a(Ch1 a)and DOC were the most significant variables influencing the AAPB community structure.Furthermore,Porphyrobacter and Rhodospirillales-like pufM sequences were positively correlated with Ch1 a,indicating potential influence of cyanobacterial blooms on these AAPB taxa.These results suggested that diverse AAPB ecotypes coexisted in Taihu Lake,and their ecological role in carbon cycling in the lake may not be ignored.
基金supported by the Science and Technology Program of Tianjin in China(Grant No.:23ZYJDSS00030).
文摘Plant-derived nanovesicles have gained attention given their similarity to mammalian exosomes and advantages such as low cost,sustainability,and tissue targeting.Thus,they hold promise for disease treatment and drug delivery.In this study,we proposed a time-efficient method,PEG 8000 combined with sucrose density gradient centrifugation to prepare ginger-derived nanovesicles(GDNVs).Subsequently,curcumin(CUR)was loaded onto GDNV by ultrasonic incubation.The optimum conditions for ginger-derived nanovesicles loaded with curcumin(CG)were ultrasound time of 3 min,a carrier-to-drug ratio(GDNV:CUR)of 1:1.The study achieved a high loading capacity(94.027%±0.094%)and encapsulation efficiency(89.300%±0.344%).Finally,the drugs'in vivo distribution and anti-colitis activity were investigated in mice.CG was primarily distributed in the colon after oral administration.Compared to CUR and GDNV,CG was superior in improving disease activity,colon length,liver and spleen coefficients,myeloperoxidase activity,and biochemical factor levels in ulcerative colitis(UC)mice.In addition,CG plays a protective role against UC by modulating serum metabolite levels and gut flora.In summary,our study demonstrated that GDNV can be used for CUR delivery with enhanced therapeutic potential.
基金supported by National Natural Science Foundation of China(No.31830016 and 31800534)。
文摘Elucidating the regulatory mechanisms of environmental factors on seed dormancy and germination will provide guidance for tree regeneration.Toward understanding the coupled effect of light and temperature on dormancy release and germination of Pinus koraiensis seeds,we set up three light conditions(L200:200μmol m^(-2) s^(-1),L20:20μmol m^(-2) s^(-1),L0:0μm^(-2) s^(-1))and four storage temperatures[T-5:-5°C(50 days),T5:-5°C(50 days)+5°C(50 days),T25:-5°C(50 days)+5°C(50 days)+25°C(50 days),T15:-5°C(50 days)+5°C(50 days)+25°C(50 days)+15°C(50 days)]using imbibed seeds,then quantified phytohormones gibberellic acid(GA_(3))and abscisic acid(ABA)during the stratification.Germination percentage(G_(P)),mean germination time(T_(M)),and germination value(G_(V))under 25/15°C temperature and the three light conditions were then determined.Phytohormone levels and germination performances were significantly affected by light and temperature.No consistent trend was found between the phytohormone levels and G_(P) caused by light levels.Under the three light conditions,ABA concentrations in the embryo and endosperm decreased as storage temperature shifted from T-5 to T25 and increased from T25 to T15;GA_(3) decreased in nearly all four storage temperatures.G_(P) reached 40–60%in T25 storage without light irradiance.In the three light conditions,G_(P) and G_(V) were higher at T5 and T25 than at T-5 and T15;so T5 and T25 are considered as optimum storage temperatures for dormancy release and germination.At optimum temperatures,light(L200,L20)significantly increased the G_(P) and G_(V) compared with the dark(L0).At L200 and L20,significant negative correlations between G_(V) and the ABA concentrations and positive correlations between G_(V) and GA/ABA in the seed embryo were found.Temperature played a more important role in primary dormancy release and germination;light was unnecessary for primary dormancy release.Light facilitated seed germination at optimum temperatures.The dormancy release and germination of P.koraiensis seeds were controlled by a decrease in ABA concentrations or an increase in GA/ABA induced by temperature variations.
基金financially supported by the National Natural Science Foundation of China(No.41772124)National Science and Technology Major Project(No.2016ZX05007001-002).
文摘A series of Monomethyl branched alkanes compounds were detected between nC14-nC36,in immature and low maturity Jurassic humic coal,Junggar basin.2-methyl alkanes and 3-methyl alkanes accounted for the vast majority of the compounds.It is worth noting that the2-methyl alkanes in the humic coal samples show an obvious distribution of even carbon predominances rarely reported in the literature.The results show that with the increase of Pr/Ph(pristane/phytane),the even carbon dominance of 2-methyl alkanes is more obvious,while the odd carbon number distribution of 3-methyl alkanes is weakened.As Pr/Ph increases in the humic coal,the relative content of the hopanes increased,while the relative content of 2-methyl alkanes and 3-methyl alkanes increases first and then decreases.
基金supported by the National Natural Science Foundation of China(Nos.21601121,21305086)the Natural Science Foundation of Shanghai(No.18ZR1416400)+1 种基金support of the Shanghai University of Engineering Science(Nos.201810856017,A1-0601-19-01017)the Opening Project of Shanghai Key Laboratory of Chemical Biology for financial support。
文摘Highly active and stable magnetic copper catalysts were successfully achieved by magnetic induced Stober method and subsequent hydrothermal reaction with copper ions in alkaline condition.The high content of Cu2+as well as the unique structures of hierarchical copper silicate in the as-prepared catalysts endowed their outstanding catalytic performance.Efficient decarboxylative A3-coupling of a-keto acid,amine and alkyne was realized with the low Fe3 O4@CuSiO3 loading.A range of propargylamines were produced in good to excellent yields under solvent-free condition.Moreover,the catalyst can be easily separated from the final organic product with an external magnet.Also,this kind of catalyst could be recycled up to six times while maintaining its activity.
基金This work was supported by the National Natural Science Foundation of China(81670977 and 51903169)Sichuan Province Science and Technology Support Program(2017SZ0030)+3 种基金China Postdoctoral Science Foundation(2019M663529)Special Funding of State Key Laboratory of Oral Diseases(SKLOD202019)Postdoctoral Cross Funding of Sichuan University(0040304153059)Research Funding for talents developing,West China Hospital of Stomatology,Sichuan University(RCDWJS2020-17).
文摘Tooth enamel is prone to be attacked by injurious factors,leading to a de/remineralization imbalance.To repair demineralized enamel and prevent pulp inflammation caused by biofilm accumulation,measures are needed to promote remineralization and inhibit bacterial adhesion on the tooth surface.An innovative material,poly(aspartic acid)-polyethylene glycol(PASP-PEG),was designed and synthesized to construct a mineralizing and anti-adhesive surface that could be applied to repair demineralized enamel.A cytotoxicity assay revealed the low cytotoxicity of synthesized PASP-PEG.Adsorption results demonstrated that PASPPEG possesses a high binding affinity to the hydroxyapatite(HA)/tooth surface.In vitro experiments and scanning electron microscopy(SEM)demonstrated a strong capacity of PASP-PEG to induce in situ remineralization and direct the oriented growth of apatite nanocrystals.Energy dispersive X-ray spectroscopy(EDS),X-ray diffraction analysis(XRD)and Vickers hardness tests demonstrated that minerals induced by PASP-PEG were consistent with healthy enamel in Ca/P ratio,crystal form and surface micro-hardness.Contact angle tests and bacterial adhesion experiments demonstrated that PASP-PEG yielded a strong antiadhesive effect.In summary,PASP-PEG could achieve dual effects for enamel repair and anti-adhesion of bacteria,thereby widening its application in enamel repair.
基金supported by the National Natural Science Foundation of China (Grant No. NSFC62004182)the Career Development Grant of Institute of Chemical Materials (Grant No. STB-2021-10)the Sichuan Science and Technology Program (Grant No. 2022JDRC0021)。
文摘Commercialization of perovskite solar cells(PSCs) requires the development of high-efficiency devices with none current density-voltage(J-V) hysteresis. Here, electron transport layers(ETLs) with gradual change in work function(WF) are successfully fabricated and employed as an ideal model to investigate the energy barriers, charge transfer and recombination kinetics at ETL/perovskite interface. The energy barrier for electron injection existing at ETL/perovskite is directly assessed by surface photovoltage microscopy, and the results demonstrate the tunable barriers have significant impact on the J-V hysteresis and performance of PSCs. By work function engineering of ETL, PSCs exhibit PCEs over 21% with negligible hysteresis. These results provide a critical understanding of the origin reason for hysteresis effect in planar PSCs, and clear reveal that the J-V hysteresis can be effectively suppressed by carefully tuning the interface features in PSCs. By extending this strategy to a modified formamidinium-cesium-rubidium(FA-Cs-Rb) perovskite system, the PCEs are further boosted to 24.18%. Moreover, 5 cm × 5 cm perovskite mini-modules are also fabricated with an impressive efficiency of 20.07%, demonstrating compatibility and effectiveness of our strategy on upscaled devices.
