Night lighting has been shown to affect wild animals.To date,the effects of night lighting on the metabolic homeostasis of birds that spend short time in urban environments remain unclear.Using model bird species Zebr...Night lighting has been shown to affect wild animals.To date,the effects of night lighting on the metabolic homeostasis of birds that spend short time in urban environments remain unclear.Using model bird species Zebra Finch(Taeniopygia guttata),we investigated the effects of short-term night lighting on liver transcriptome,blood glucose,triglyceride,and thyroxine(T4 and T3)levels in birds exposed to two different night lighting duration periods(three days and six days).After three days of night lighting exposure,the expression of genes involved in fat synthesis in the liver was upregulated while the expression of genes involved in fatty acid oxidation and triglyceride decomposition was downregulated.There was also a reduction in blood triglyceride,glucose,and T3 concentrations.However,after six days of night lighting,the expression of genes associated with fatty acid decomposition and hyperglycemia in the liver was upregulated,while the expression of genes involved in fat synthesis was downregulated.Simultaneously,blood glucose levels and T3 concentration increased.These findings indicate that short-term exposure to night lighting can disrupt the lipid and glucose metabolism of small passerine birds,and longer stopovers in urban area with intense night lighting may cause birds to consume more lipid energy.展开更多
With exhaustion of fossil fuels and the deterioration of global environment,widespread and intensive researches have been concentrated on clean and sustainable alternative energy sources,such as metal-air batteries[1]...With exhaustion of fossil fuels and the deterioration of global environment,widespread and intensive researches have been concentrated on clean and sustainable alternative energy sources,such as metal-air batteries[1],fuel cells[2]and water splitting devices[3].Electrocatalytic oxidation of water to O2(oxygen evolution reaction,OER)is a vital chemical process involved in energy storage and conversion from renewable sources in form of molecular fuels such as H2 via water electrolysis,which has attracted a great amount of research efforts in the past few years[4,5].Nowadays,RuO2 and IrO2 are widely used as typical excellent OER electrocatalysts.However,their high-cost and scarce nature restricts the broadly commercial application of those materials[6,7].Hence,there is an urgent demand to develop low cost,highly efficient,and superb stable OER catalysts.展开更多
Background:In high latitude grassland habitats,altricial nestlings hatching in open-cup nests early in the breeding season must cope with cold temperature challenges.Thyroid hormones(triiodothyronine,T_(3)and thyroxin...Background:In high latitude grassland habitats,altricial nestlings hatching in open-cup nests early in the breeding season must cope with cold temperature challenges.Thyroid hormones(triiodothyronine,T_(3)and thyroxine,T_(4))and corticosterone play a crucial role in avian thermoregulation response to cold.Investigating the endocrine response of altricial nestlings to temperature variation is important for understanding the adaptive mechanisms of individual variation in the timing of breeding in birds.Methods:We compared nest temperature,ambient temperature,body temperature,plasma T_(3),T_(4)and corticosterone levels in Asian Short-toed Lark(Alaudala cheleensis)nestlings hatching in the early-,middle-,and late-stages of the breeding season in Hulunbuir grassland,northeast China.Results:Mean nest temperature in the early-,middle-and late-stage groups was-1.85,3.81 and 10.23℃,respectively,for the 3-day-old nestlings,and 6.83,10.41 and 11.81℃,respectively,for the 6-day-old nestlings.The nest temperature significantly correlated with body temperature,plasma T_(3),T_(4)and corticosterone concentrations of nestlings.Body temperature of 3-day-old nestlings in the early and middle groups was significantly lower than that of the late group,but there was no significant difference between the nestlings in the early and middle groups.The T_(4)and T_(3)concentrations and the ratio of T_(3)/T_(4)of both 3-and 6-day-old nestlings in the early-stage group were significantly higher compared to the middle and late groups.The corticosterone levels of 3-day-old nestlings were significantly higher in the early-stage group compared to the middle-and late-stage groups.Conclusion:Nestlings hatching early responded to cold temperature by increasing thyroid hormones and corticosterone levels even in the early days of post hatching development when the endothermy has not been established.These hormones may play a physiological role in neonatal nestlings coping with cold temperature challenges.展开更多
Low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from funct...Low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from functional groups on the tensile properties of carbon nanothreads(NTH)– a new sp~3 carbon nanostructure. It is found that functional groups will alter the local bond configuration and induce initial stress concentration, which significantly reduces the fracture strain/strength of NTH. Different functional types lead to different local bond reconfigurations, and introduce different impacts on NTH. Further studies reveal that the tensile properties decreases generally when the content of functional groups increases. However, some NTHs with higher content of functional groups exhibit higher fracture strain/strength than their counterparts with lower percentage. Such observations are attributed to the synergetic effects from the sample length, self-oscillation, and distribution of functional groups. Simulations show that the tensile behaviour of NTH with the same functional percentage differs when the distribution pattern varies. Overall, ethyl groups are found to induce larger degradation on the tensile properties of NTH than methyl and phenyl groups. This study provides a comprehensive understanding of the influence from functional groups, which should be beneficial to the engineering applications of NTH.展开更多
A new coupling axial flux variable-reluctance resolver is put forward on the basis of existing reluctance resolver. The coupling area of stator and rotor is calculated by using calculus method. The magneticmotive forc...A new coupling axial flux variable-reluctance resolver is put forward on the basis of existing reluctance resolver. The coupling area of stator and rotor is calculated by using calculus method. The magneticmotive force of four-phase signal windings is deduced under the case of different number of pole pairs. The theoretical derivation and finite element analysis of signal windings of precision machine are done when the number of teeth and pole pairs changes. Study on properties of the new resolver is conducive to further optimize,and it will be widely used in more and more fields.展开更多
The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS a...The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS and Particle-phase ROS,abbreviated to G-ROS and P-ROS)were measured by an online instrument in parallel with concurrent PM_(2.5) sample collections analyzed for chemical composition and cellular ROS in a baseline year(Coal Use Year-CUY)and the first year following implementation of the“Coal to Electricity”program(Coal Ban Year-CBY).The results showed PM_(2.5) concentrations had no significant difference between the two sampling periods,but the activities of G-ROS,P-ROS,and cellular ROS in CBY were 8.72 nmol H_(2)O_(2)/m^(3),9.82 nmol H 2 O 2/m 3,and 2045.75μg UD/mg PM higher than in CUY.Six sources were identified by factor-analysis from the chemical components of PM_(2.5).Secondary sources(SECs)were the dominant source of PM_(2.5) in the two periods,with 15.90%higher contribution in CBY than in CUY.Industrial Emission&Coal Combustion sources(Ind.&CCs),mainly from regional transport,also increased significantly in CBY.The contributions of Aged Sea Salt&Residential Burning sources to PM_(2.5) decreased 5.31% from CUY to CBY.The correlation results illustrated that Ind.&CCs had significant positive correlations with atmospheric ROS,and SECs significantly associated with cellular ROS,especially nitrates(r=0.626,p=0.000).Therefore,the implementation of the“Coal to Electricity”program reduced PM_(2.5) contributions from coal and biomass combustion,but had little effect on the improvement of atmospheric and cellular ROS.展开更多
Heavy metal pollution has attracted worldwide attention because of its adverse impact on the aquatic environment and human health.The production of biochar from biowaste has become a promising strategy for managing an...Heavy metal pollution has attracted worldwide attention because of its adverse impact on the aquatic environment and human health.The production of biochar from biowaste has become a promising strategy for managing animal carcasses and remediating heavy metal pollution in the aquatic environment.However,the sorption and remediation performance of carp residue-derived biochar(CRB)in Cu-polluted water is poorly understood.Herein,batches of CRB were prepared from carp residues at 450–650℃(CRB450–650)to investigate their physicochemical characteristics and performance in the sorption and remediation of Cu-polluted water.Compared with a relatively low-temperature CRB(e.g.,CRB450),the high-temperature biochar(CRB650)possessed a large surface area and thermodynamic stability.CRB650 contained higher oxygen-containing functional groups and P-associated minerals,such as hydroxyapatite.As the pyrolytic temperature increased from 450 to 650℃,the maximum sorption capacity of the CRBs increased from 26.5 to 62.5 mg/g.The adsorption process was a type of monolayer adsorption onto homogenous materials,and the sorption of Cu^(2+)on the CRB was mainly based on chemical adsorption.The most effective potential adsorption mechanisms were in order of electrostatic attraction and cation-πinteraction>surface complexation and precipitation>pore-filling and cation exchange.Accordingly,the CRBs efficiently immobilized Cu^(2+)and reduced its bioavailability in water.These results provide a promising strategy to remediate heavy metal-polluted water using designer biochars derived from biowastes,particularly animal carcasses.展开更多
Background: Estradiol, as an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization embryo transfer (IVF-ET) cycles. The aim of...Background: Estradiol, as an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization embryo transfer (IVF-ET) cycles. The aim of this retrospective study was to evaluate the association between elevated serum estradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and IVF-ET pregnancy and birth outcomes. Methods: A total of 1771 infertile patients with their first fresh IVF-ET cycles were analyzed retrospectively between January 2011 and January 2016 in Peking University First Hospital. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E2 levels < 1000 pg/mL, n = 205), group 2 (serum E2 levels 1001-2000 pg/mL, n = 457), group 3 (serum E2 levels 2001-3000 pg/mL, n = 425), group 4 (serum E2 levels 3001-4000 pg/mL, n = 310), group 5 (serum E2 levels 4001- 5000 pg/mL, n = 237), and group 6 (serum E2 levels > 5000 pg/mL, n — 137). The retrieved oocyte and Mil oocyte numbers and implantation and clinical pregnancy rates of the groups were compared as the first objective of the study. For the 360 women with singleton births among all patients, the area under the corresponding receiver operating characteristic curve (ROC curve) was calculated to assess the predictive value of the E2 change for the probability of low birth weight (LBW) infants as the second objective. Results: The retrieved oocyte and Mil oocyte numbers and implantation and clinical pregnancy rates gradually increased from groups 1 to 5 but decreased in group 6. The parameters of group 1 were statistically worse than those of the other groups, from group 2 to group 6 (the number of retrieved oocytes, t = 13.096, t = 23.307, t = 23.086, t = 26.376, t = 19.636, P < 0.003;the number of retrieved Mil oocytes, t = 10.856, t = 20.868, t = 21.874, t = 23.374, t = 19.092, P < 0.003;the implantation rate,χ^2= 12.179,χ^2= 22.239,χ^2= 23.993,χ^2= 23.344,χ^2= 16.758, P < 0.003;the clinical pregnancy rate,χ^2= 16.415,χ^2= 28.074,χ^2= 35.387,χ^2= 37.025,χ^2= 24.590, P < 0.003). ROC analysis revealed that when a serum peak E2 of 3148 pg/mL was used to predict LBW. Conclusions: The results indicate that serum E2 levels have a concentration-dependent effect on clinical outcomes. The optimal range of the E2 level during a fresh IVF-ET cycle is 1000 to 3148 pg/mL.展开更多
The studies on heterogeneous reactions over montmorillonite,which is a typical 2:1 layered aluminosilicate,will benefit to the understanding of heterogeneous reactions on clay minerals.Montmorillonite can be classifie...The studies on heterogeneous reactions over montmorillonite,which is a typical 2:1 layered aluminosilicate,will benefit to the understanding of heterogeneous reactions on clay minerals.Montmorillonite can be classified as sodium montmorillonite or calcium montmorillonite depending on the cation presented between the different layers.Using diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),the heterogeneous reaction mechanism of NO2 on the surface of montmorillonite was firstly investigated.Results showed that the reaction of NO2 on the surface of sodium and calcium montmorillonite fit a first-order kinetics,and the reaction duration of calcium montmorillonite was longer than that of sodium montmorillonite under the dry condition.For either sodium or calcium montmorillonite,the uptake coefficient decreased as humidity increased.展开更多
Ozone(O3) is an important atmospheric oxidant. Black carbon(BC) particles released into the atmosphere undergo an aging process via O3 oxidation. O3-aged BC particles may change their uptake ability toward trace reduc...Ozone(O3) is an important atmospheric oxidant. Black carbon(BC) particles released into the atmosphere undergo an aging process via O3 oxidation. O3-aged BC particles may change their uptake ability toward trace reducing gases such as SO2 in the atmosphere,leading to different environmental and health effects. In this paper, the heterogeneous reaction process between O3-aged BC and SO2 was explored via in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS). Combined with ion chromatography(IC),DRIFTS was used to qualitatively and quantitatively analyze the sulfate product. The results showed that O3-aged BC had stronger SO2 oxidation ability than fresh BC, and the reactive species/sites generated on the surface had an important role in the oxidation of SO2.Relative humidity or 254 nm UV(ultraviolet) light illumination enhanced the oxidation uptake of SO2 on O3-aged BC. The oxidation potentials of the BC particles were detected via dithiothreitol(DTT) assay. The DTT activity over BC was decreased in the process of SO2 reduction, with the consumption of oxidative active sites.展开更多
Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered envir...Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered environmentally friendly,the understanding on absorbing and oxidative capacity of soot emitted from them are still unclear.The watersoluble organic carbon(WSOC)content,surface chemical structure,light absorption and oxidative potential(OPDTT)of soot from biodiesel/diesel and chemicals/diesel blends were investigated utilizing total organic carbon analyzer,X-ray photoelectron spectrometer,ultraviolet–visible spectrophotometry and dithiothreitol(DTT)assay.The differences and correlations between soot properties were statistically analyzed.Chemicals/diesel blends soot owned significantly higher WSOC content,ratio of mass absorbing efficiency(MAE)in250 and 365 nm(E2/E3),OPDTT,and higher surface carbonyl content.Coconut biodiesel/diesel blends soot contained evidently higher aromatic carbon–oxygen single bond(ArC–O)content,and higher MAE365.The individual comparison of biodiesel/diesel blends showed20%coconut biodiesel blend owned the lowest WSOC,E2/E3 and OPDTT,while highest ArC–O and MAE365,representing strongest absorbing properties.Association analysis showed OPDTTwas significantly positively correlated with WSOC.Further,the evident negative correlation between MAE365 and OPDTT was observed.Our results showed coconut biodiesel/diesel blends soot induced lower levels of oxidative potential,whereas absorption of light was higher,which have far reaching consequences on climate forcing.Therefore,it is important to evaluate the balance point between light-absorbing properties and oxidative potential,under the wide use of biodiesel.展开更多
Anodization is a popular method of preparing TiO_2 nanotube array films(TiNTs) by using direct current(DC)power as the driving voltage.In this study,three driving voltage modes,namely,the sine alternating current(sine...Anodization is a popular method of preparing TiO_2 nanotube array films(TiNTs) by using direct current(DC)power as the driving voltage.In this study,three driving voltage modes,namely,the sine alternating current(sine) mode,the full-wave rectification of sine waves via four diodes(sine-4D,where D means diode) mode,and the DC mode,were used to prepare TiNTs by anodization.At 20 V,TiNTs were formed under sine-4D mode but only irregular porous TiO_2 films were formed under DC mode.At 50 V,TiNTs formed under both the sine-4D and DC modes.No TiNTs formed in the sine mode anodization at either 20 or 50 V.Compared with the DC mode,the sine-4D mode required a lower oxidation voltage for TiNT formation,which suggests that sine-4D is an economical,convenient,and efficient driving voltage for TiNT preparation by anodization.The morphologies and structures of TiNT samples anodized at 50 V in the sine-4D and DC modes at different oxidation time(1,5,10,30,60,and 120 min) were analyzed.TiNT growth processes were similar between the studied modes.However,the growth rate of the films was faster under the sine-4D mode than the DC mode during the first 30 min of anodization.展开更多
Graphene oxide(GO),a new and promising material,has been widely used as a co-catalyst in photocatalytic reactions;however,its capacity as a sole photocatalyst has rarely been investigated.In this study,ultraviolet(UV)...Graphene oxide(GO),a new and promising material,has been widely used as a co-catalyst in photocatalytic reactions;however,its capacity as a sole photocatalyst has rarely been investigated.In this study,ultraviolet(UV) light irradiation was used as a modification method to obtain reduced GO(rGO) samples.The samples were used as photocatalysts to examine their visible light photocatalytic activity toward hexavalent chromium(Cr(Ⅵ)) removal.Atomic force microscopy(AFM),X-ray diffraction(XRD),UV-vis spectrophotometry,Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and electron spin resonance(ESR) spectroscopy were applied to interpret the surface and structure changes with UV irradiation.The oxygen-containing functional groups(OFGs) on the GO surface were reduced to defective carbons andπ-conjugated C=C(sp^(2) domains) under UV light;this led to a decrease in the interlayer distance between GO sheets,GO fragmentation,and increased disorder on the GO surface.The restoration of sp^(2) domains led to a narrower band gap of GO,which favored the rGO excitation by visible light to generate electron-hole pairs.The rGO pre-irradiated with UV for 1 h(rGO-1),possessing the highest defect density and electron generation efficiency,exhibited the best Cr(Ⅵ) reduction efficiency,which was about three times that of the GO sample;moreover,it outperformed most of the reported GO-based nanomaterials.In addition,low pH and the addition of citric acid as a hole scavenger could further improve the photocatalytic activity.This study proves that GO or rGO can be used as a sole photocatalyst under visible light to remove environmental pollutants such as heavy-metal ions,and it paves the way for the development of this kind of material and its UV-irradiation modification for further applications.展开更多
Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogen...Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.展开更多
The reaction of HCHO with Beijing winter's real ambient particulate matter(PM) inside a 3.3 m^3 Teflon Chamber was conducted in this study. NO_2, O_3 and H_2O gases were removed from the ambient aerosol before ent...The reaction of HCHO with Beijing winter's real ambient particulate matter(PM) inside a 3.3 m^3 Teflon Chamber was conducted in this study. NO_2, O_3 and H_2O gases were removed from the ambient aerosol before entering into the chamber. The decays of HCHO were monitored(acetylacetone spectrophotometry method) during the reactions at different PM number concentrations(N_a) and relative humidities(RHs), and the formed particulate formate was detected by IC and XPS techniques. The results showed that when RH was10%–15%, the decay rate of HCHO in the chamber was higher with the existence of PM from relatively clean days(with number concentration(N_a) < 200,000 particle/L, 0.35–22.5 μm)compared to dirty days(N_a> 200,000 particle/L, 0.35–22.5 μm). When RH increased to 30%–45%, PM can hardly have significant influences on the decay of HCHO. The formations of formate on the reacted PM were consistent with the HCHO decay rates at different ambient PM N_aand RH conditions. This is a first study related to the "real" ambient PM reacted with HCHO and suggested that in the clean and low RH days, PM could be an effective medium for the conversion of HCHO to formate.展开更多
We designed photoelectrochemical cells to achieve efficient oxidation ofrhodamine B (RhB)without the need for photocatalyst or supporting electrolyte.RhB,the metal anode/cathode,and O2 formed an energy-relay structure...We designed photoelectrochemical cells to achieve efficient oxidation ofrhodamine B (RhB)without the need for photocatalyst or supporting electrolyte.RhB,the metal anode/cathode,and O2 formed an energy-relay structure,enabling the efficient formation of O2^- species under ultraviolet illumination.In a single-compartment cell (S cell)containing a titanium (Ti)anode,Ti cathode,and 10mg·mL^-1 RhB in water,the zero-order rate constant of the photoelectrochemical oxidation (kPEC)of RhB was 0.049mg·L^-1·min^-1,while those of the photochemical and electrochemical oxidations of RhB were nearly zero.kPEC remained almost the same when 0.5mol·L^-1 Na2SO4 was included in the reactive solution,regardless of the increase in the photocurrent of the S cell.The kpEc of the illuminated anode comoartment in the two-compartment cell,including a Ti anode,Ti cathode,and 10mg·mL^-1 RhB in water,was higher than that of the S cell.These results support a simple,eco-friendly,and energy saving method to realize the efficient degradation of RhB.展开更多
Breast cancer is one of the most common cancers in the world,survival rates of breast cancer are rising as screening and treatment improve.Many new technologies applied in the biomedical domain have been born for rapi...Breast cancer is one of the most common cancers in the world,survival rates of breast cancer are rising as screening and treatment improve.Many new technologies applied in the biomedical domain have been born for rapid diagnosis and treatment.In this work,visualization cell microarray chip with threedimensional(3 D)embedded cell scaffold for cell diagnosis and treatment was designed.DNA segment,targeting on breast cancer cells SK-BR-3,were modified with camptothecin and used as model drug.Cell microarray chip system successfully control the diffusion of small molecules and locally introduced the compounds into cells.3 D embedded cell scaffold in the cell array chip afforded an environment with continuous medium supplementary and help controlling the diffusion of small molecules drugs.By cell microarray chip system,SK-BR-3 was targeted screening and killing in one step.Cell microarray chip system can achieve accurate,rapid diagnosis and target treatment of breast cancer cells SK-BR-3 and have a potential to develop to be an effective and accurate drug screen method for evaluating the drug effect of the booming chemicals.展开更多
基金supported by grants from Key laboratory of Ecology and Environment in Minority Area,National Ethnic Affairs Commission(KLEEMA202207)the Graduate Research and Practice Projects of Minzu University of China(BZKY2022042).
文摘Night lighting has been shown to affect wild animals.To date,the effects of night lighting on the metabolic homeostasis of birds that spend short time in urban environments remain unclear.Using model bird species Zebra Finch(Taeniopygia guttata),we investigated the effects of short-term night lighting on liver transcriptome,blood glucose,triglyceride,and thyroxine(T4 and T3)levels in birds exposed to two different night lighting duration periods(three days and six days).After three days of night lighting exposure,the expression of genes involved in fat synthesis in the liver was upregulated while the expression of genes involved in fatty acid oxidation and triglyceride decomposition was downregulated.There was also a reduction in blood triglyceride,glucose,and T3 concentrations.However,after six days of night lighting,the expression of genes associated with fatty acid decomposition and hyperglycemia in the liver was upregulated,while the expression of genes involved in fat synthesis was downregulated.Simultaneously,blood glucose levels and T3 concentration increased.These findings indicate that short-term exposure to night lighting can disrupt the lipid and glucose metabolism of small passerine birds,and longer stopovers in urban area with intense night lighting may cause birds to consume more lipid energy.
基金financially supported by the National Natural Science Foundation of China(U1707603,21521005,21975013,21901017)the National Key Research and Development Program of China(2017YFA0206500,2018YFA0702000)+2 种基金Beijing Natural Science Foundation(2172042)PetroChina Innovation Foundationthe Fundamental Research Funds for the Central Universities。
文摘With exhaustion of fossil fuels and the deterioration of global environment,widespread and intensive researches have been concentrated on clean and sustainable alternative energy sources,such as metal-air batteries[1],fuel cells[2]and water splitting devices[3].Electrocatalytic oxidation of water to O2(oxygen evolution reaction,OER)is a vital chemical process involved in energy storage and conversion from renewable sources in form of molecular fuels such as H2 via water electrolysis,which has attracted a great amount of research efforts in the past few years[4,5].Nowadays,RuO2 and IrO2 are widely used as typical excellent OER electrocatalysts.However,their high-cost and scarce nature restricts the broadly commercial application of those materials[6,7].Hence,there is an urgent demand to develop low cost,highly efficient,and superb stable OER catalysts.
基金supported by the National Natural Science Foundation of China(No.32071515)。
文摘Background:In high latitude grassland habitats,altricial nestlings hatching in open-cup nests early in the breeding season must cope with cold temperature challenges.Thyroid hormones(triiodothyronine,T_(3)and thyroxine,T_(4))and corticosterone play a crucial role in avian thermoregulation response to cold.Investigating the endocrine response of altricial nestlings to temperature variation is important for understanding the adaptive mechanisms of individual variation in the timing of breeding in birds.Methods:We compared nest temperature,ambient temperature,body temperature,plasma T_(3),T_(4)and corticosterone levels in Asian Short-toed Lark(Alaudala cheleensis)nestlings hatching in the early-,middle-,and late-stages of the breeding season in Hulunbuir grassland,northeast China.Results:Mean nest temperature in the early-,middle-and late-stage groups was-1.85,3.81 and 10.23℃,respectively,for the 3-day-old nestlings,and 6.83,10.41 and 11.81℃,respectively,for the 6-day-old nestlings.The nest temperature significantly correlated with body temperature,plasma T_(3),T_(4)and corticosterone concentrations of nestlings.Body temperature of 3-day-old nestlings in the early and middle groups was significantly lower than that of the late group,but there was no significant difference between the nestlings in the early and middle groups.The T_(4)and T_(3)concentrations and the ratio of T_(3)/T_(4)of both 3-and 6-day-old nestlings in the early-stage group were significantly higher compared to the middle and late groups.The corticosterone levels of 3-day-old nestlings were significantly higher in the early-stage group compared to the middle-and late-stage groups.Conclusion:Nestlings hatching early responded to cold temperature by increasing thyroid hormones and corticosterone levels even in the early days of post hatching development when the endothermy has not been established.These hormones may play a physiological role in neonatal nestlings coping with cold temperature challenges.
基金Support from the ARC Discovery Project (DP180103009, DP200102546)the High-Performance Computing (HPC) resources provided by the Queensland University of Technology(QUT)。
文摘Low dimensional sp~3 carbon nanostructures have attracted increasing attention recently, due to their unique properties and appealing applications. Based on in silico studies, this work exploits the impacts from functional groups on the tensile properties of carbon nanothreads(NTH)– a new sp~3 carbon nanostructure. It is found that functional groups will alter the local bond configuration and induce initial stress concentration, which significantly reduces the fracture strain/strength of NTH. Different functional types lead to different local bond reconfigurations, and introduce different impacts on NTH. Further studies reveal that the tensile properties decreases generally when the content of functional groups increases. However, some NTHs with higher content of functional groups exhibit higher fracture strain/strength than their counterparts with lower percentage. Such observations are attributed to the synergetic effects from the sample length, self-oscillation, and distribution of functional groups. Simulations show that the tensile behaviour of NTH with the same functional percentage differs when the distribution pattern varies. Overall, ethyl groups are found to induce larger degradation on the tensile properties of NTH than methyl and phenyl groups. This study provides a comprehensive understanding of the influence from functional groups, which should be beneficial to the engineering applications of NTH.
基金Sponsored by the National Key Basic Research Program of China(Grant No.2013CB035600)the National Natural Science Foundation of China(Grant No.51377031)
文摘A new coupling axial flux variable-reluctance resolver is put forward on the basis of existing reluctance resolver. The coupling area of stator and rotor is calculated by using calculus method. The magneticmotive force of four-phase signal windings is deduced under the case of different number of pole pairs. The theoretical derivation and finite element analysis of signal windings of precision machine are done when the number of teeth and pole pairs changes. Study on properties of the new resolver is conducive to further optimize,and it will be widely used in more and more fields.
基金supported by the National Natural Science Foundation of China(NSFC)(No.41877310)partly by the National Key Research and Development Program of China(No.2016YFC0503600).
文摘The Beijing“Coal to Electricity”program provides a unique opportunity to explore air quality impacts by replacing residential coal burning with electrical appliances.In this study,the atmospheric ROS(Gas-phase ROS and Particle-phase ROS,abbreviated to G-ROS and P-ROS)were measured by an online instrument in parallel with concurrent PM_(2.5) sample collections analyzed for chemical composition and cellular ROS in a baseline year(Coal Use Year-CUY)and the first year following implementation of the“Coal to Electricity”program(Coal Ban Year-CBY).The results showed PM_(2.5) concentrations had no significant difference between the two sampling periods,but the activities of G-ROS,P-ROS,and cellular ROS in CBY were 8.72 nmol H_(2)O_(2)/m^(3),9.82 nmol H 2 O 2/m 3,and 2045.75μg UD/mg PM higher than in CUY.Six sources were identified by factor-analysis from the chemical components of PM_(2.5).Secondary sources(SECs)were the dominant source of PM_(2.5) in the two periods,with 15.90%higher contribution in CBY than in CUY.Industrial Emission&Coal Combustion sources(Ind.&CCs),mainly from regional transport,also increased significantly in CBY.The contributions of Aged Sea Salt&Residential Burning sources to PM_(2.5) decreased 5.31% from CUY to CBY.The correlation results illustrated that Ind.&CCs had significant positive correlations with atmospheric ROS,and SECs significantly associated with cellular ROS,especially nitrates(r=0.626,p=0.000).Therefore,the implementation of the“Coal to Electricity”program reduced PM_(2.5) contributions from coal and biomass combustion,but had little effect on the improvement of atmospheric and cellular ROS.
基金This work was financially supported by the Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi Province(China)(No.2021L460)the Key R&D Project of Shaanxi Province(China)(No.2022NY-054)+1 种基金the Hainan Provincial Joint Project of Sanya Yazhou Bay Science and Technology City(China)(No.220LH061)the Natural Science Fund for Distinguished Young Scholars of Shandong Province(China)(No.ZR2021JQ13).
文摘Heavy metal pollution has attracted worldwide attention because of its adverse impact on the aquatic environment and human health.The production of biochar from biowaste has become a promising strategy for managing animal carcasses and remediating heavy metal pollution in the aquatic environment.However,the sorption and remediation performance of carp residue-derived biochar(CRB)in Cu-polluted water is poorly understood.Herein,batches of CRB were prepared from carp residues at 450–650℃(CRB450–650)to investigate their physicochemical characteristics and performance in the sorption and remediation of Cu-polluted water.Compared with a relatively low-temperature CRB(e.g.,CRB450),the high-temperature biochar(CRB650)possessed a large surface area and thermodynamic stability.CRB650 contained higher oxygen-containing functional groups and P-associated minerals,such as hydroxyapatite.As the pyrolytic temperature increased from 450 to 650℃,the maximum sorption capacity of the CRBs increased from 26.5 to 62.5 mg/g.The adsorption process was a type of monolayer adsorption onto homogenous materials,and the sorption of Cu^(2+)on the CRB was mainly based on chemical adsorption.The most effective potential adsorption mechanisms were in order of electrostatic attraction and cation-πinteraction>surface complexation and precipitation>pore-filling and cation exchange.Accordingly,the CRBs efficiently immobilized Cu^(2+)and reduced its bioavailability in water.These results provide a promising strategy to remediate heavy metal-polluted water using designer biochars derived from biowastes,particularly animal carcasses.
文摘Background: Estradiol, as an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization embryo transfer (IVF-ET) cycles. The aim of this retrospective study was to evaluate the association between elevated serum estradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and IVF-ET pregnancy and birth outcomes. Methods: A total of 1771 infertile patients with their first fresh IVF-ET cycles were analyzed retrospectively between January 2011 and January 2016 in Peking University First Hospital. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E2 levels < 1000 pg/mL, n = 205), group 2 (serum E2 levels 1001-2000 pg/mL, n = 457), group 3 (serum E2 levels 2001-3000 pg/mL, n = 425), group 4 (serum E2 levels 3001-4000 pg/mL, n = 310), group 5 (serum E2 levels 4001- 5000 pg/mL, n = 237), and group 6 (serum E2 levels > 5000 pg/mL, n — 137). The retrieved oocyte and Mil oocyte numbers and implantation and clinical pregnancy rates of the groups were compared as the first objective of the study. For the 360 women with singleton births among all patients, the area under the corresponding receiver operating characteristic curve (ROC curve) was calculated to assess the predictive value of the E2 change for the probability of low birth weight (LBW) infants as the second objective. Results: The retrieved oocyte and Mil oocyte numbers and implantation and clinical pregnancy rates gradually increased from groups 1 to 5 but decreased in group 6. The parameters of group 1 were statistically worse than those of the other groups, from group 2 to group 6 (the number of retrieved oocytes, t = 13.096, t = 23.307, t = 23.086, t = 26.376, t = 19.636, P < 0.003;the number of retrieved Mil oocytes, t = 10.856, t = 20.868, t = 21.874, t = 23.374, t = 19.092, P < 0.003;the implantation rate,χ^2= 12.179,χ^2= 22.239,χ^2= 23.993,χ^2= 23.344,χ^2= 16.758, P < 0.003;the clinical pregnancy rate,χ^2= 16.415,χ^2= 28.074,χ^2= 35.387,χ^2= 37.025,χ^2= 24.590, P < 0.003). ROC analysis revealed that when a serum peak E2 of 3148 pg/mL was used to predict LBW. Conclusions: The results indicate that serum E2 levels have a concentration-dependent effect on clinical outcomes. The optimal range of the E2 level during a fresh IVF-ET cycle is 1000 to 3148 pg/mL.
基金supported by the National Natural Science Foundation of China (No. 41005071,40490265,20637020)the National Basic Research Program of China(No. 2002CB410802 )the Special Fund of State Key Joint Laboratory of Environment Simulation and Pollution Control (No. 09K01ESPCP)
文摘The studies on heterogeneous reactions over montmorillonite,which is a typical 2:1 layered aluminosilicate,will benefit to the understanding of heterogeneous reactions on clay minerals.Montmorillonite can be classified as sodium montmorillonite or calcium montmorillonite depending on the cation presented between the different layers.Using diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS),the heterogeneous reaction mechanism of NO2 on the surface of montmorillonite was firstly investigated.Results showed that the reaction of NO2 on the surface of sodium and calcium montmorillonite fit a first-order kinetics,and the reaction duration of calcium montmorillonite was longer than that of sodium montmorillonite under the dry condition.For either sodium or calcium montmorillonite,the uptake coefficient decreased as humidity increased.
基金the financial support provided by the National Natural Science Foundation of China(Nos.21277004,21190051,41121004)the Beijing Natural Science Foundation(No.8132035)+1 种基金the Fujitsu Laboratories Limited Foundation(No.k120400)the Special Fund of State Key Joint Laboratory of Environmental Simulation and Pollution Control(2015)
文摘Ozone(O3) is an important atmospheric oxidant. Black carbon(BC) particles released into the atmosphere undergo an aging process via O3 oxidation. O3-aged BC particles may change their uptake ability toward trace reducing gases such as SO2 in the atmosphere,leading to different environmental and health effects. In this paper, the heterogeneous reaction process between O3-aged BC and SO2 was explored via in-situ diffuse reflectance infrared Fourier transform spectroscopy(DRIFTS). Combined with ion chromatography(IC),DRIFTS was used to qualitatively and quantitatively analyze the sulfate product. The results showed that O3-aged BC had stronger SO2 oxidation ability than fresh BC, and the reactive species/sites generated on the surface had an important role in the oxidation of SO2.Relative humidity or 254 nm UV(ultraviolet) light illumination enhanced the oxidation uptake of SO2 on O3-aged BC. The oxidation potentials of the BC particles were detected via dithiothreitol(DTT) assay. The DTT activity over BC was decreased in the process of SO2 reduction, with the consumption of oxidative active sites.
基金supported by the National Natural Science Foundation of China(Nos.21577003,21876003)the National Key Research and Development Program of China(No.2016YFC0202200)+1 种基金the Australian Research Council under Discovery Project(No.DP180102632)the special fund of State Key Joint Laboratory of Environment Simulation and Pollution Control(No.19Y02ESPCP)
文摘Soot particles,mainly coming from fuel combustion,affect climate forcing through absorbing light and also result in adverse human health outcomes.Though biodiesel or additives blending with diesel was considered environmentally friendly,the understanding on absorbing and oxidative capacity of soot emitted from them are still unclear.The watersoluble organic carbon(WSOC)content,surface chemical structure,light absorption and oxidative potential(OPDTT)of soot from biodiesel/diesel and chemicals/diesel blends were investigated utilizing total organic carbon analyzer,X-ray photoelectron spectrometer,ultraviolet–visible spectrophotometry and dithiothreitol(DTT)assay.The differences and correlations between soot properties were statistically analyzed.Chemicals/diesel blends soot owned significantly higher WSOC content,ratio of mass absorbing efficiency(MAE)in250 and 365 nm(E2/E3),OPDTT,and higher surface carbonyl content.Coconut biodiesel/diesel blends soot contained evidently higher aromatic carbon–oxygen single bond(ArC–O)content,and higher MAE365.The individual comparison of biodiesel/diesel blends showed20%coconut biodiesel blend owned the lowest WSOC,E2/E3 and OPDTT,while highest ArC–O and MAE365,representing strongest absorbing properties.Association analysis showed OPDTTwas significantly positively correlated with WSOC.Further,the evident negative correlation between MAE365 and OPDTT was observed.Our results showed coconut biodiesel/diesel blends soot induced lower levels of oxidative potential,whereas absorption of light was higher,which have far reaching consequences on climate forcing.Therefore,it is important to evaluate the balance point between light-absorbing properties and oxidative potential,under the wide use of biodiesel.
基金the financial support provided by the National Natural Science Foundation of China (Nos. 21277004, 21190051 and 41121004)the Beijing Natural Science Foundation, China (No. 8132035)
文摘Anodization is a popular method of preparing TiO_2 nanotube array films(TiNTs) by using direct current(DC)power as the driving voltage.In this study,three driving voltage modes,namely,the sine alternating current(sine) mode,the full-wave rectification of sine waves via four diodes(sine-4D,where D means diode) mode,and the DC mode,were used to prepare TiNTs by anodization.At 20 V,TiNTs were formed under sine-4D mode but only irregular porous TiO_2 films were formed under DC mode.At 50 V,TiNTs formed under both the sine-4D and DC modes.No TiNTs formed in the sine mode anodization at either 20 or 50 V.Compared with the DC mode,the sine-4D mode required a lower oxidation voltage for TiNT formation,which suggests that sine-4D is an economical,convenient,and efficient driving voltage for TiNT preparation by anodization.The morphologies and structures of TiNT samples anodized at 50 V in the sine-4D and DC modes at different oxidation time(1,5,10,30,60,and 120 min) were analyzed.TiNT growth processes were similar between the studied modes.However,the growth rate of the films was faster under the sine-4D mode than the DC mode during the first 30 min of anodization.
基金financial support provided by National Natural Science Foundation of China (Nos.21876003 and41961134034)the Second Tibetan Plateau Scientific Expedition and Research (No.2019QZKK0607)the 111 Project Urban Air Pollution and Health Effects (B20009)。
文摘Graphene oxide(GO),a new and promising material,has been widely used as a co-catalyst in photocatalytic reactions;however,its capacity as a sole photocatalyst has rarely been investigated.In this study,ultraviolet(UV) light irradiation was used as a modification method to obtain reduced GO(rGO) samples.The samples were used as photocatalysts to examine their visible light photocatalytic activity toward hexavalent chromium(Cr(Ⅵ)) removal.Atomic force microscopy(AFM),X-ray diffraction(XRD),UV-vis spectrophotometry,Raman spectroscopy,X-ray photoelectron spectroscopy(XPS),and electron spin resonance(ESR) spectroscopy were applied to interpret the surface and structure changes with UV irradiation.The oxygen-containing functional groups(OFGs) on the GO surface were reduced to defective carbons andπ-conjugated C=C(sp^(2) domains) under UV light;this led to a decrease in the interlayer distance between GO sheets,GO fragmentation,and increased disorder on the GO surface.The restoration of sp^(2) domains led to a narrower band gap of GO,which favored the rGO excitation by visible light to generate electron-hole pairs.The rGO pre-irradiated with UV for 1 h(rGO-1),possessing the highest defect density and electron generation efficiency,exhibited the best Cr(Ⅵ) reduction efficiency,which was about three times that of the GO sample;moreover,it outperformed most of the reported GO-based nanomaterials.In addition,low pH and the addition of citric acid as a hole scavenger could further improve the photocatalytic activity.This study proves that GO or rGO can be used as a sole photocatalyst under visible light to remove environmental pollutants such as heavy-metal ions,and it paves the way for the development of this kind of material and its UV-irradiation modification for further applications.
基金supported by the Chinese Ministry of Science and Technology(No.2008AA062503)the National Natural Science Foundation Committee of China(Nos.41421064,20637020)the China Postdoctoral Science Foundation(No.20100470166)
文摘Heterogeneous reactions on the aerosol particle surface in the atmosphere play important roles in air pollution, climate change, and global biogeochemical cycles. However, the reported uptake coefficients of heterogeneous reactions usually have large variations and may not be relevant to real atmospheric conditions. One of the major reasons for this is the use of bulk samples in laboratory experiments, while particles in the atmosphere are suspended individually. A number of technologies have been developed recently to study heterogeneous reactions on the surfaces of individual particles. Precise measurements on the reactive surface area, volume, and morphology of individual particles are necessary for calculating the uptake coefficient, quantifying reactants and products, and understanding the reaction mechanism better. In this study, for the first time we used synchrotron radiation X-ray computed tomography(XCT) and micro-Raman spectrometry to measure individual CaCO_3 particle morphology, with sizes ranging from 3.5–6.5 μm. Particle surface area and volume were calculated using a reconstruction method based on software threedimensional(3-D) rendering. The XCT was first validated with high-resolution fieldemission scanning electron microscopy(FE-SEM) to acquire accurate CaCO_3 particle surface area and volume estimates. Our results showed an average difference of only 6.1% in surface area and 3.2% in volume measured either by micro-Raman spectrometry or X-ray tomography. X-ray tomography and FE-SEM can provide more morphological details of individual Ca CO3 particles than micro-Raman spectrometry. This study demonstrated that X-ray computed tomography and micro-Raman spectrometry can precisely measure the surface area, volume, and morphology of an individual particle.
基金supported by the National Natural Science Foundation of China(nos.41421064,21577003,21277004)
文摘The reaction of HCHO with Beijing winter's real ambient particulate matter(PM) inside a 3.3 m^3 Teflon Chamber was conducted in this study. NO_2, O_3 and H_2O gases were removed from the ambient aerosol before entering into the chamber. The decays of HCHO were monitored(acetylacetone spectrophotometry method) during the reactions at different PM number concentrations(N_a) and relative humidities(RHs), and the formed particulate formate was detected by IC and XPS techniques. The results showed that when RH was10%–15%, the decay rate of HCHO in the chamber was higher with the existence of PM from relatively clean days(with number concentration(N_a) < 200,000 particle/L, 0.35–22.5 μm)compared to dirty days(N_a> 200,000 particle/L, 0.35–22.5 μm). When RH increased to 30%–45%, PM can hardly have significant influences on the decay of HCHO. The formations of formate on the reacted PM were consistent with the HCHO decay rates at different ambient PM N_aand RH conditions. This is a first study related to the "real" ambient PM reacted with HCHO and suggested that in the clean and low RH days, PM could be an effective medium for the conversion of HCHO to formate.
基金The authors are grateful to the financial support provided by National Natural Science Foundation of China (Grant Nos. 21577003,21277004and 41421064)the National Key Research and Development Program of China (No.2016YFC0202200) Beijing Natural Science Foundation (No.8132035).
文摘We designed photoelectrochemical cells to achieve efficient oxidation ofrhodamine B (RhB)without the need for photocatalyst or supporting electrolyte.RhB,the metal anode/cathode,and O2 formed an energy-relay structure,enabling the efficient formation of O2^- species under ultraviolet illumination.In a single-compartment cell (S cell)containing a titanium (Ti)anode,Ti cathode,and 10mg·mL^-1 RhB in water,the zero-order rate constant of the photoelectrochemical oxidation (kPEC)of RhB was 0.049mg·L^-1·min^-1,while those of the photochemical and electrochemical oxidations of RhB were nearly zero.kPEC remained almost the same when 0.5mol·L^-1 Na2SO4 was included in the reactive solution,regardless of the increase in the photocurrent of the S cell.The kpEc of the illuminated anode comoartment in the two-compartment cell,including a Ti anode,Ti cathode,and 10mg·mL^-1 RhB in water,was higher than that of the S cell.These results support a simple,eco-friendly,and energy saving method to realize the efficient degradation of RhB.
基金supported by the National Natural Science Foundation of China(Nos.11204033,51773093)the Natural Science Foundation of Jiangsu Province(No.BK20141397)+4 种基金the Research Fund for the Doctoral Program of Higher Education of China(No.20120092120042)the CMA L’OREAL CHINA SKIN GRANT 2015(No.S2015121421)the Open Research Fund of State Key Laboratory of Natural Medicines,China Pharmaceutical University(No.SKLNMKF201803)Southeast University and Nanjing Medical University Cooperation Project(No.2242018K3DN14)Open Research Fund of State Key Laboratory of Bioelectronics,Southeast University
文摘Breast cancer is one of the most common cancers in the world,survival rates of breast cancer are rising as screening and treatment improve.Many new technologies applied in the biomedical domain have been born for rapid diagnosis and treatment.In this work,visualization cell microarray chip with threedimensional(3 D)embedded cell scaffold for cell diagnosis and treatment was designed.DNA segment,targeting on breast cancer cells SK-BR-3,were modified with camptothecin and used as model drug.Cell microarray chip system successfully control the diffusion of small molecules and locally introduced the compounds into cells.3 D embedded cell scaffold in the cell array chip afforded an environment with continuous medium supplementary and help controlling the diffusion of small molecules drugs.By cell microarray chip system,SK-BR-3 was targeted screening and killing in one step.Cell microarray chip system can achieve accurate,rapid diagnosis and target treatment of breast cancer cells SK-BR-3 and have a potential to develop to be an effective and accurate drug screen method for evaluating the drug effect of the booming chemicals.
