Excessive abdominal fat deposition seriously restricts the production efficiency of broilers.Several studies found that dietary supplemental manganese(Mn)could effectively reduce the abdominal fat deposition of broile...Excessive abdominal fat deposition seriously restricts the production efficiency of broilers.Several studies found that dietary supplemental manganese(Mn)could effectively reduce the abdominal fat deposition of broilers,but the underlying mechanisms remain unclear.The present study aimed to investigate the effect of dietary supplementation with the inorganic or organic Mn on abdominal fat deposition,and enzyme activity and gene expression involved in lipid metabolism in the abdominal fat of male or female broilers.A total of 4201-d-old AA broilers(half males and half females)were randomly allotted by body weight and gender to 1 of 6 treatments with 10 replicates cages of 7 chicks per cage in a completely randomized design involving a 3(dietary Mn addition)×2(gender)factorial arrangement.Male or female broilers were fed with the Mn-unsupplemented basal diets containing 17.52 mg Mn kg^(-1)(d 1-21)and 15.62 mg Mn kg^(-1)(d 22-42)by analysis or the basal diets supplemented with 110 mg Mn kg^(-1)(d 1-21)and 80 mg Mn kg^(-1)(d 22-42)as either the Mn sulfate or the Mn proteinate with moderate chelation strength(Mn-Prot M)for 42 d.The results showed that the interaction between dietary Mn addition and gender had no impact(P>0.05)on any of the measured parameters;abdominal fat percentage of broilers was decreased(P<0.003)by Mn addition;Mn addition increased(P<0.004)adipose triglyceride lipase(ATGL)activity,while Mn-Prot M decreased(P<0.002)the fatty acid synthase(FAS)activity in the abdominal fat of broilers compared to the control;Mn addition decreased(P<0.009)diacylglycerol acyltransferase 2(DGAT2)mRNA expression level and peroxisome proliferator-activated receptor γ(PPARγ)mRNA and protein expression levels,but up-regulated(P<0.05)the ATGL mRNA and protein expression levels in the abdominal fat of broilers.It was concluded that dietary supplementation with Mn inhibited the abdominal fat deposition of broilers possibly via decreasing the expression of PPARγand DGAT2 as well as increasing the expression and activity of ATGL in the abdominal fat of broilers,and Mn-Prot M was more effective in inhibiting the FAS acitivity.展开更多
Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed highe...Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sources relative to FeSO_(4)·7H_(2)O were closely related to their Qf values,and NaFeEDTA sources with higher Qf values showed higher Fe bioavailabilities for broilers fed with a conventional corn-soybean meal diet.展开更多
Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells,drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help recons...Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells,drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct agood microenvironment for tissue repair. In order to achieve more ideal performance and face more complextissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond toexternal stimuli. These microcarriers have the functions of directional movement, targeted enrichment, materialrelease control, and providing signals conducive to tissue repair. Given the high controllability and designabilityof magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in thisreview. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed.In summary, through the design with clinical translation ability, meaningful and comprehensiveexperimental characterization, and in-depth study and application of tissue repair mechanisms, stimuliresponsivemicrocarriers have great potential in tissue repair.展开更多
Background:The current calcium(Ca)recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today.And the ...Background:The current calcium(Ca)recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today.And the response indicators in these studies are mainly growth performance and bone ash percentage.Therefore,the present study was carried out to investigate the effect of dietary Ca level on growth performance,serum parameters,bone characteristics and Ca metabolism-related gene expressions,so as to estimate dietary Ca requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.Methods:A total of 4201-day-old Arbor Acres male broilers were randomly assigned to 1 of 7 treatments with 6 replicates(10 birds per cage)and fed the corn-soybean meal diets containing 0.60%,0.70%,0.80%,0.90%,1.00%,1.10%or 1.20%Ca for 21 days.Each diet contained the constant non-phytate phosphorus content of about 0.39%.Results:The average daily gain decreased linearly(P<0.001)as dietary Ca level increased.The serum and tibia alkaline phosphatase(ALP)activities,tibia bone mineral density(BMD),middle toe BMD,tibia ash percentage,tibia breaking strength,and tibia ALP protein expression level were affected(P<0.05)by dietary Ca level,and showed significant quadratic responses(P<0.02)to dietary Ca levels.The estimates of dietary Ca requirements were 0.80 to 1.00%based on the best fitted broken-line or quadratic models(P<0.03)of the above serum and bone parameters,respectively.Conclusions:The results from the present study indicate that the Ca requirements would be about 0.60%to obtain the best growth rate,and 1.00%to meet all of the Ca metabolisms and bone development of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.展开更多
随着人类社会的高速发展,在保证环境不被破坏的情况下维持众多机械和电气设备的正常运转急需清洁的能源方式。氢被认为是在未来最有前景的清洁能源之一。近期,电化学水分解已被认为是获取氢能的最有效的方法之一,它的燃料产物只是无污...随着人类社会的高速发展,在保证环境不被破坏的情况下维持众多机械和电气设备的正常运转急需清洁的能源方式。氢被认为是在未来最有前景的清洁能源之一。近期,电化学水分解已被认为是获取氢能的最有效的方法之一,它的燃料产物只是无污染的水;然而,迟缓的析氧反应严重制约了水分解效率,导致驱动水分解的电压相对较高。探求热力学有利的阳极反应以取代缓慢的氧析出和开发高活性双功能型电催化剂用于这种阳极反应和析氢对于实现可应用于工业的节能型产氢至关重要。当前,普遍认为用其他有用的且利于热力学的反应取代析氧反应可以减小分解电压从而实现节能产氢。本文报道了一种用于甲醇氧化和析氢的双功能型嵌入镍纳米粒子的碳棱柱状微米棒电催化剂(命名为镍碳微米棒),该催化剂是由74号金属有机框架结构经碳化处理获得。这种由镍和碳构成的界面材料结构通过原位碳化实现,由于碳的分隔作用,分散的镍纳米颗粒不会轻易团聚,这有利于暴露更多的镍活性位点与电解液相接触,为更快的催化剂和电解液间电荷转移和电化学动力学提供保障。在此阳极的甲醇氧化中,产物分别为二氧化碳和甲酸,两者在1.55 V电压下的法拉第效率分别为36.2%和62.5%;同时该镍碳微米棒催化剂表现出优异的甲醇氧化活性和耐久性(12 h持续性催化,电流仅衰退2.7%)。值得注意的是,该双功能催化剂不仅具有甲醇氧化活性,在室温下含有0.5mol·L^(-1)甲醇的1.0mol·L^(-1)氢氧化钾电解液中的析氢过电位也较低(仅155 m V的过电位即可驱动10 m A·cm^(-2)的电流),保证了产氢效率。更重要的是,采用这种双功能型电极构造的双电极电解槽仅需1.6 V电压即可驱动10 m A·cm^(-2)的电流,与析氧反应作为阳极反应的电解槽相比驱动电压减小了240 mV。展开更多
Background:Phosphorus is essential for bone mineralization in broilers,however,the underlying mechanisms remain unclear.We aimed to investigate whether bone phosphorus retention and bone development might be regulated...Background:Phosphorus is essential for bone mineralization in broilers,however,the underlying mechanisms remain unclear.We aimed to investigate whether bone phosphorus retention and bone development might be regulated by related hormones and local bone-derived regulators in broilers.Methods:Broilers were fed diets containing different levels of non-phytate phosphorus(NPP)0.15%,0.25%,0.35%,0.45% and 0.55% or 0.15%,0.22%,0.29%,0.36% and 0.43% from 1 to 21 or 22 to 42 days of age.Serum and tibia samples were collected for determinations of bone phosphorus retention and bone development parameters,related hormones and local bone-derived regulators of broiler chickens on d 14,28 and 42,respectively.Results:Tibia ash phosphorus,total phosphorus accumulation in tibia ash(TP_(TA)),bone mineral concentration(BMC),bone mineral density(BMD),bone breaking strength(BBS),and ash on d 14,28 or 42,serum 1,25-dihydroxyvitamin D_(3)(1,25(OH)_(2)D_(3))on d 28 and 42,mRNA expressions of tibia fibroblast growth factor 23(FGF23)and dentin matrix protein 1(DMP1)on d 14 and 28 increased linearly or quadratically(P<0.05),while serum parathyroid hormone(PTH)on d 28,tibia alkaline phosphatase(ALP)on d 14,28 and 42,bone gal protein(BGP)on d 14,and mRNA expression of tibia phosphate-regulating gene with homologies to endopeptidases on the X chromosome(PHEX)on d 14 and 28 decreased linearly or quadratically(P<0.04)as dietary NPP level increased.TPTA,BMC,BMD,and ash on d 28 and 42,BBS on d 28,and ash phosphorus on d 42 were positively correlated(r=0.389 to 0.486,P<0.03)with serum 1,25(OH)_(2)D_(3).All of the above parameters were positively correlated(r=0.380 to 0.689,P<0.05)with tibia DMP1 mRNA expression on d 14,28 and 42,but negatively correlated(r=−0.609 to−0.538,P<0.02)with serum PTH on d 28,tibia ALP on d 14,28 and 42,and BGP on d 14.TP_(TA),BMC and ash on d 14 and BMD on d 28 were negatively correlated(r=−0.397 to−0.362,P<0.03)with tibia PHEX mRNA expression,and BMD on d 28 was positively correlated(r=0.384,P=0.04)with tibia FGF23 mRNA expression.Conclusions:These results suggested that bone phosphorus retention and bone development parameters had moderate to strong correlations with serum PTH and 1,25(OH)2D3 and tibia DMP1,PHEX,FGF23,ALP and BGP in broilers during the whole growth period,and thus they might be partly regulated by these related hormones and local bone-derived regulators.展开更多
Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of emission.GaN-on-silicon microdisks can provide a per...Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of emission.GaN-on-silicon microdisks can provide a perfect cavity structure for such resonance to occur.Here we report GaN-based microdisks with different diameters,based on a standard blue LED wafer on a Si substrate.A confocal photoluminescence spectroscopy is performed to analyze the properties of all microdisks.Then,we systematically study the effects of radial modes and axial modes of these microdisks on photon-electron coupling efficiency by using three-dimensional finite-difference time-domain simulations.For thick microdisks,photon-electron coupling efficiency is found to greatly depend on the distributions of both the radial modes and the axial modes,and the inclined sidewalls make significant influences on the axial mode distributions.These results are important for realization of high-efficiency resonant emission in GaN-based microcavity devices.展开更多
This paper is to provide an empirical work for agricultural spatial distribution of agriculture. We consider the spatial location pattern in order to offer spatial views on the agricultural economic research and how C...This paper is to provide an empirical work for agricultural spatial distribution of agriculture. We consider the spatial location pattern in order to offer spatial views on the agricultural economic research and how Chinese agricultural economic spatial location pattern is forming, we also tested the agglomeration situation of agriculture and the process is going on in the future. The results indicate that the periphery areas exist significant differential among regions in Hunan province, China. It really presents some kinds of agglomeration pattern of agriculture and characteristic spatial autocorrelation;the biggest rate of contribution to the region agriculture economic gap is productivity per agriculture worker.展开更多
This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were rand...This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were randomly allotted 6 treatments with 8 replicate cages(6 broilers per cage)per treatment.Broilers were fed a Cu-unsupplemented corn-soybean meal basal diet(control,containing 7.36 mg Cu/kg)or the basal diet added with 3,6,9,12,or 15 mg Cu/kg from CuSO_(4)·5H_(2)O for 21 d.Quadratic,asymptotic and broken-line models were fitted and the best fitted models were selected to determine dietary Cu requirements.The results revealed that the contents of Cu in serum and liver,m RNA expression levels of Cu-and zinc-containing superoxide dismutase(CuZnSOD)in liver and monoamine oxidase b(MAO B)in heart,as well as protein expression level of CuZnSOD in liver were affected(P<0.05)by supplemental Cu levels,and the above indices varied linearly and quadratically(P<0.05)with increasing Cu levels.Dietary Cu requirements assessed according to the best fitted broken-line models(P<0.05)of the above indexes were 10.45—13.81 mg/kg.It was concluded that mRNA expression levels of CuZnSOD in liver and MAO B in heart,as well as liver CuZnSOD protein expression level were new specific sensitive biomarkers for estimating dietary Cu requirements,and the dietary Cu requirement was recommended to be 14 mg/kg to support Cu metabolic needs related to key Cucontaining enzymes in broilers fed the corn-soybean meal diet during 22—42 d of age,which was higher than the dietary Cu requirement(8 mg/kg)for broilers at the corresponding stage suggested by the Chinese Feeding Standard of Chicken.展开更多
From the viewpoint of earth system science,this paper discusses the observation capability of the second-generation of Chinese polar-orbiting,sun-synchronous operational meteorological satellite observation systems,Fe...From the viewpoint of earth system science,this paper discusses the observation capability of the second-generation of Chinese polar-orbiting,sun-synchronous operational meteorological satellite observation systems,Fengyun-3(FY-3),based on the function and performance test results from the FY-3 D satellite observation system in orbit.The FY-3 series of satellites have numerous remote sensing instruments and a wide range of imaging and sounding electromagnetic spectrometers onboard.These instruments can obtain reflectivity data for land surface,soil,vegetation,water body,snow cover,ocean color,and sea ice on earth’s surface over a wide spectral range,as well as information on the absorption and scattering radiative transfer of molecules and particles(clouds and aerosols)in earth’s atmosphere.All of these data can be used to retrieve physical and chemical information about the land,ocean,and atmosphere of the earth system.Comprehensive observation of the earth system by the FY-3 meteorological satellites is preliminarily realized.展开更多
The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical ...The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues.A total of 384 one-d-old male broilers(n=8 replicates/diet)were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1,0.2,0.3,0.4 or 0.5 mg Se/kg in the form of Na_(2)SeO_(3) for 21 d.Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line,quadratic or asymptotic models.The activity of glutathione peroxidase(GPX)in the plasma,liver,kidney and pancreas,iodothyronine deiodinase(DIO)in the plasma,liver and pancreas,and thioredoxin reductase(Txnrd)in the liver and pancreas,the mRNA levels of Gpx1,Gpx4,Dio1,selenoprotein(Seleno)h,Selenop and Selenou in the liver,Gpx4,Dio1,Txnrd1,Txnrd2,Selenoh,Selenop and Selenou in the kidney,and Gpx1,Gpx4,Selenoh and Selenou in the pancreas,and the protein levels of GPX4 in the liver and kidney of broilers were influenced(P<0.05)by added Se levels,and increased quadratically(P<0.05)with the increase of added Se levels.The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line,quadratic or asymptotic models(P<0.001)of the aforementioned selenoprotein expression in the plasma,liver and kidney,and 0.09 to 0.46 mg/kg based on the fitted broken-line models(P<0.001)of the aforementioned selenoprotein expression in the pancreas.The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma,liver and kidney,and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.展开更多
Zinc(Zn)has been shown to attenuate the adverse effects of heat stress on broilers,but the mechanisms involving this process remain unclear.We aimed to investigate possible protective mechanisms of Zn on primary cultu...Zinc(Zn)has been shown to attenuate the adverse effects of heat stress on broilers,but the mechanisms involving this process remain unclear.We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress.Three experiments were conducted.In Exp.1,hepatocytes were treated with 0,50,100,200,or 400μmol/L added Zn as inorganic Zn sulfate(iZn)for 12,24 or 48 h.In Exp.2,cells were exposed to 40℃(a normal temperature[NT])and 44℃(a high temperature[HT])for 1,2,4,6,or 8 h.In Exp.3,cells were preincubated with 0 or 50μmol/L Zn as iZn or organic Zn lysine chelate(oZn)for 8 h under NT,and then incubated with the same Zn treatments under NT or HT for 4 or 6 h.The biomarkers of antioxidative status and heat stress in cells were measured.The results in Exp.1 indicated that 50μmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes.In Exp.2,the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes.In Exp.3,HT elevated(P<0.01)malondialdehyde content and expressions of heat shock protein 70(HSP70)mRNA and protein,as well as HSP90 mRNA.However,Zn supplementation increased(P<0.05)copper zinc superoxide dismutase(CuZnSOD)activity and metallothionein mRNA expression,and effectively decreased(P<0.05)the ex-pressions of HSP70 mRNA and protein,as well as HSP90 mRNA.Furthermore,oZn was more effective(P<0.05)than iZn in enhancing CuZnSOD activity of hepatocytes under HT.It was concluded that Zn(especially oZn)could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.展开更多
The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers from 22 to 42 d of age is primarily based on a previous study reported in 1986,which might not be applicable to modern classes of rapidly growing ...The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers from 22 to 42 d of age is primarily based on a previous study reported in 1986,which might not be applicable to modern classes of rapidly growing broilers.The present experiment was conducted to determine the optimal dietary Se level for meeting metabolic and functional Se requirements of broilers fed a corn-soybean meal diet from 22 to 42 d of age.A total of 336 Arbor Acres male broilers at 22 d old were randomly assigned to 1 of 6 treatments with 7 replicates and fed a basal corn-soybean meal diet(control,containing 0.014 mg Se/kg)and the basal diet supplemented with 0.10,0.20,0.30,0.40,or 0.50 mg Se/kg from Na_(2)SeO_(3) for 21 d.The results showed that the Se concentrations in plasma,liver,kidney,pancreas,breast and thigh muscles,the activity of glutathione peroxidase(GPX)in plasma,liver and kidney,the mRNA expression levels of Gpx4,selenoprotein(Seleno)h and Selenou in liver,Selenop and Selenoh in kidney,and the protein expression levels of GPX4 in the liver and kidney of broilers were affected(P<0.05)by supplemental Se level,and increased quadratically(P<0.05)with the increase of supplemental Se level.The estimates of optimal dietary Se levels were 0.10 to 0.49 mg/kg based on the fitted broken-line or asymptotic models(P<0.0001)of the above Se concentration indices,and 0.08 to 0.37 mg/kg based on the fitted brokenline,quadratic or asymptotic models(P<0.007)of the above selenoprotein expression indices.These results indicate that the optimal dietary Se levels would be 0.49 mg/kg to support the maximum Se concentrations and 0.37 mg/kg to support the full expression of selenoproteins in plasma and various tissues of broilers fed a corn-soybean meal diet from 22 to 42 d of age.展开更多
No information is available regarding the utilization of iron (Fe) from different Fe sources at a targettissue level. To detect differences in Fe metabolic utilization among Fe sources, the effect of intravenouslyinje...No information is available regarding the utilization of iron (Fe) from different Fe sources at a targettissue level. To detect differences in Fe metabolic utilization among Fe sources, the effect of intravenouslyinjected Fe on growth performance, hematological indices, tissue Fe concentrations and Fe-containingenzyme activities and gene expressions of Fe-containing enzymes or protein in broilers was investigated.On d 22 post-hatching, a total of 432 male chickens were randomly allotted to 1 of 9 treatments ina completely randomized design. Chickens were injected with either a 0.9% (wt/vol) NaCl solution(control) or a 0.9% NaCl solution supplemented with Fe sulphate or 1 of 3 organic Fe sources. The 3organic Fe sources were Fe chelates with weak (Fe-MetW), moderate (Fe-ProtM) or extremely strong (Fe-ProtES) chelation strength. The 2 Fe dosages were calculated according to the Fe absorbabilities of 10%and 20% every 2 d for a duration of 20 d. Iron injection did not affect (P > 0.05) ADFI, ADG or FCR duringeither 1 to 10 d or 11 to 20 d after injections. Hematocrit and Fe concentrations in the liver and kidney ond 10 after Fe injections, and Fe concentrations in the liver or pancreas and ferritin heavy-chain (FTH1)protein expression level in the liver or spleen on d 20 after Fe injections increased (P≤0.05) as injectedFe dosages increased. When the injected Fe level was high at 20% Fe absorbability, the chickens injectedwith Fe-ProtES had lower (P < 0.001) liver or kidney Fe concentrations and spleen FTH1 protein levelsthan those injected with Fe-MetW or Fe-ProtM on d 20 after injections. And they had lower (P < 0.05)liver cytochrome C oxidase mRNA levels on d 20 after injections than those injected with Fe-MetW or Fesulphate. The results from this study indicate that intravenously injected Fe from Fe-ProtES was the least utilizable and functioned in the sensitive target tissue less effectively than Fe from Fe sulfate, Fe-MetW or Fe-ProtM.展开更多
In this work,the air dielectric barrier discharge plasma was applied to a model of protein human serum albumin to explore plasma‐mediated protein damage from a biomolecular perspective.Carbonylation and side chain mo...In this work,the air dielectric barrier discharge plasma was applied to a model of protein human serum albumin to explore plasma‐mediated protein damage from a biomolecular perspective.Carbonylation and side chain modifications of protein in solution were observed by Fourier transform infrared(FT‐IR)spectroscopy and mass spectrometry(MS).Protein backbone cleavage is proved by Bradford assay,sodium dodecyl sulphate–polyacrylamide gel electrophoresis,and MS.Typical fragments are in the range of 10–12 kDa.The decrease inα‐helix and increase inβ‐sheet indicated by FT‐IR are major protein secondary structure changes.Accordingly,a whole map of protein oxidative damage and structural changes in response to the plasma was postulated.展开更多
The visible infrared radiometer(VIRR)is the first instrument with longest measurements equipped on the Fengyun(FY)polar-orbiting satellites.Through re-processing of the historic VIRR measurements,long-term(over 20 yr)...The visible infrared radiometer(VIRR)is the first instrument with longest measurements equipped on the Fengyun(FY)polar-orbiting satellites.Through re-processing of the historic VIRR measurements,long-term(over 20 yr)global data can be integrated from multiple participating VIRRs on a consistent radiometric scale,which are valuable to climate and climate change studies.Due to lack of an onboard calibration system for VIRR,the reflective solar bands must be vicariously calibrated.This study applied the multi-site vicarious approach for consistent calibration of the VIRR visible(VIS)and near-infrared(NIR)data,and produced calibration coefficients for five VIRRs on FY-1 C/D and FY-3 A/B/C.The data quality was then evaluated with observations.The reflectance predicted by using the radiative transfer model over multiple invariant desert and ocean targets was used to derive the calibration slope via a weighted fitting scheme,in which the weights are the inverse of the variance from a radiative transfer simulation evaluated with reference to Aqua moderate resolution imaging spectroradiometer(MODIS).The sensor-specific calibration coefficients were derived on a daily basis by using piecewise polynomials.The calibration reference of the VIRR solar band record was further traced to the Aqua MODIS Collection 6.1 reference calibration with a systematic correction derived from the Libya4 desert.The VIRR record was compared with the Aqua MODIS C6.1 calibration over the polar region based on simultaneous nadir overpass observations.The lifetime relative difference for each sensor are within 3.3%and 4.5%for channels 1 and 2.Invariant deserts were also employed to evaluate the stability and consistency of the VIRR record.In general,the means of the directional and spectral corrected reflectance for each sensor are within 1%of the 20-yr average,implying that the VIRR reflectance of the invariant targets is consistent to within 1%among the sensors for channels 1 and 2.The VIRR data thus derived are reliable.展开更多
The current dietary copper(Cu)requirement(8 mg/kg)of broilers is mainly based on growth,hemoglobin concentration,or hematocrit,which might not be the most sensitive indices to evaluate dietary Cu requirements of broil...The current dietary copper(Cu)requirement(8 mg/kg)of broilers is mainly based on growth,hemoglobin concentration,or hematocrit,which might not be the most sensitive indices to evaluate dietary Cu requirements of broilers.The present study was carried out to estimate dietary Cu requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age using biochemical or molecular biomarkers.A total of 3841-d-old Arbor Acres male broilers were randomly allocated to 1 of 6 treatments with 8 replicates and fed a Cu-unsupplemented corn-soybean meal basal diet containing 5.17 mg Cu/kg by analysis and the basal diet supplemented with 3,6,9,12 or 15 mg Cu/kg as CuSO4,5H2O for 21 d.Regression analysis was performed to estimate the optimal dietary Cu level using the broken-line model.Dietary supplemental Cu level affected(P<0.05)Cu contents in serum and liver and kidney monoamine oxidase(MAO)activity,but had no effects(P>0.05)on the growth performance,Cu contents in heart,kidney,pancreas and spleen,Cu-and zinc-containing superoxide dismutase(CuZnSOD)activity and ceruloplasmin content in serum,CuZnSOD and cytochrome c oxidase(COX)activities and ceruloplasmin,CuZnSOD,MAO A,MAO B,COX 4I1 and COX 1 mRNA and protein expressions in the above tissues of broilers.As dietary supplemental Cu levels increased,Cu contents in serum and liver increased linearly(P<0.05),but kidney MAO activity decreased linearly and quadratically(P<0.05).The estimated dietary Cu requirement based on the fitted broken-line model(P=0.035)of kidney MAO activity was 11.30 mg/kg.In conclusion,kidney MAO activity is a new and sensitive criterion to evaluate the dietary Cu requirement of broilers,and the dietary Cu requirement was 11.30 mg/kg for broilers fed the conventional corn-soybean meal diet from 1 to 21 d of age,which is higher than the current National Research Council(NRC)Cu requirement(8 mg/kg)of broilers.展开更多
New U-Pb zircon geochronology data suggest that the Yintun Formation is younger man ~ 1895 Ma and is late Paleoproterozoic.The Yintun Formation may represent the first sedimentary cover of the North China Craton(NCC)b...New U-Pb zircon geochronology data suggest that the Yintun Formation is younger man ~ 1895 Ma and is late Paleoproterozoic.The Yintun Formation may represent the first sedimentary cover of the North China Craton(NCC)based on its stratigraphic sequence and the ages of its sediments.Gravels in the conglomerates from the lower member of the Yintun Formation are characterized by obvious glacial origins.It is possible that these glacial gravels are the re-deposited sedimentary products of the Huronian Glaciation from the Indian continent.This can also provide sedimentary evidence for the relative location of the Indian continent and the NCC in the reconstruction of the Columbia supercontinent.展开更多
基金financially supported by the National Natural Science Foundation of China(32102559)the Jiangsu Shuang Chuang Tuan Dui Program,China(JSSCTD202147)the Jiangsu Shuang Chuang Ren Cai Program,China(JSSCRC2021541)。
文摘Excessive abdominal fat deposition seriously restricts the production efficiency of broilers.Several studies found that dietary supplemental manganese(Mn)could effectively reduce the abdominal fat deposition of broilers,but the underlying mechanisms remain unclear.The present study aimed to investigate the effect of dietary supplementation with the inorganic or organic Mn on abdominal fat deposition,and enzyme activity and gene expression involved in lipid metabolism in the abdominal fat of male or female broilers.A total of 4201-d-old AA broilers(half males and half females)were randomly allotted by body weight and gender to 1 of 6 treatments with 10 replicates cages of 7 chicks per cage in a completely randomized design involving a 3(dietary Mn addition)×2(gender)factorial arrangement.Male or female broilers were fed with the Mn-unsupplemented basal diets containing 17.52 mg Mn kg^(-1)(d 1-21)and 15.62 mg Mn kg^(-1)(d 22-42)by analysis or the basal diets supplemented with 110 mg Mn kg^(-1)(d 1-21)and 80 mg Mn kg^(-1)(d 22-42)as either the Mn sulfate or the Mn proteinate with moderate chelation strength(Mn-Prot M)for 42 d.The results showed that the interaction between dietary Mn addition and gender had no impact(P>0.05)on any of the measured parameters;abdominal fat percentage of broilers was decreased(P<0.003)by Mn addition;Mn addition increased(P<0.004)adipose triglyceride lipase(ATGL)activity,while Mn-Prot M decreased(P<0.002)the fatty acid synthase(FAS)activity in the abdominal fat of broilers compared to the control;Mn addition decreased(P<0.009)diacylglycerol acyltransferase 2(DGAT2)mRNA expression level and peroxisome proliferator-activated receptor γ(PPARγ)mRNA and protein expression levels,but up-regulated(P<0.05)the ATGL mRNA and protein expression levels in the abdominal fat of broilers.It was concluded that dietary supplementation with Mn inhibited the abdominal fat deposition of broilers possibly via decreasing the expression of PPARγand DGAT2 as well as increasing the expression and activity of ATGL in the abdominal fat of broilers,and Mn-Prot M was more effective in inhibiting the FAS acitivity.
基金funded by Jiangsu Shuang Chuang Tuan Dui program (JSSCTD202147)Jiangsu Shuang Chuang Ren Cai program (JSSCRC2021541)+1 种基金Young Elite Scientists Sponsorship Program by CAST (2022QNRC001)the Initiation Funds of Yangzhou University for Distinguished Scientists
文摘Background Our previous studies demonstrated that divalent organic iron(Fe)proteinate sources with higher complexation or chelation strengths as expressed by the greater quotient of formation(Qf)values displayed higher Fe bioavailabilities for broilers.Sodium iron ethylenediaminetetraacetate(NaFeEDTA)is a trivalent organic Fe source with the strongest chelating ligand EDTA.However,the bioavailability of Fe when administered as NaFeEDTA in broilers and other agricultural animals remains untested.Herein,the chemical characteristics of 12 NaFeEDTA products were determined.Of these,one feed grade NaFeEDTA(Qf=2.07×10^(8)),one food grade NaFeEDTA(Qf=3.31×10^(8)),and one Fe proteinate with an extremely strong chelation strength(Fe-Prot ES,Qf value=8,590)were selected.Their bioavailabilities relative to Fe sulfate(FeSO_(4)·7H_(2)O)for broilers fed with a conventional corn-soybean meal diet were evaluated during d 1 to 21 by investigating the effects of the above Fe sources and added Fe levels on the growth performance,hematological indices,Fe contents,activities and gene expressions of Fe-containing enzymes in various tissues of broilers.Results NaFeEDTA sources varied greatly in their chemical characteristics.Plasma Fe concentration(PI),transferrin saturation(TS),liver Fe content,succinate dehydrogenase(SDH)activities in liver,heart,and kidney,catalase(CAT)activity in liver,and SDH mRNA expressions in liver and kidney increased linearly(P<0.05)with increasing levels of Fe supplementation.However,differences among Fe sources were detected(P<0.05)only for PI,liver Fe content,CAT activity in liver,SDH activities in heart and kidney,and SDH mRNA expressions in liver and kidney.Based on slope ratios from multiple linear regressions of the above indices on daily dietary analyzed Fe intake,the average bioavailabilities of Fe-Prot ES,feed grade NaFeEDTA,and food grade NaFeEDTA relative to the inorganic FeSO_(4)·7H_(2)O(100%)for broilers were 139%,155%,and 166%,respectively.Conclusions The bioavailabilities of organic Fe sources relative to FeSO_(4)·7H_(2)O were closely related to their Qf values,and NaFeEDTA sources with higher Qf values showed higher Fe bioavailabilities for broilers fed with a conventional corn-soybean meal diet.
基金supported by National Natural Science Foundation of China(Grant No.52273119,51973018)Key Research and Development Projects of People’s Liberation Army(BWS17J036)Beijing Science and Technology Project(Z191100002019017).
文摘Microcarrier applications have made great advances in tissue engineering in recent years, which can load cells,drugs, and bioactive factors. These microcarriers can be minimally injected into the defect to help reconstruct agood microenvironment for tissue repair. In order to achieve more ideal performance and face more complextissue damage, an increasing amount of effort has been focused on microcarriers that can actively respond toexternal stimuli. These microcarriers have the functions of directional movement, targeted enrichment, materialrelease control, and providing signals conducive to tissue repair. Given the high controllability and designabilityof magnetic and electroactive microcarriers, the research progress of these microcarriers is highlighted in thisreview. Their structure, function and applications, potential tissue repair mechanisms, and challenges are discussed.In summary, through the design with clinical translation ability, meaningful and comprehensiveexperimental characterization, and in-depth study and application of tissue repair mechanisms, stimuliresponsivemicrocarriers have great potential in tissue repair.
基金financially supported by the China Agriculture Research System of MOF and MARA (project number CARS-41,Beijing, P. R.China)the Agricultural Science and Technology Innovation Program(ASTIP-IAS09, Beijing, P. R. China)
文摘Background:The current calcium(Ca)recommendation for broilers is primarily based on studies conducted more than 30 years ago with birds of markedly different productive potentials from those which exist today.And the response indicators in these studies are mainly growth performance and bone ash percentage.Therefore,the present study was carried out to investigate the effect of dietary Ca level on growth performance,serum parameters,bone characteristics and Ca metabolism-related gene expressions,so as to estimate dietary Ca requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.Methods:A total of 4201-day-old Arbor Acres male broilers were randomly assigned to 1 of 7 treatments with 6 replicates(10 birds per cage)and fed the corn-soybean meal diets containing 0.60%,0.70%,0.80%,0.90%,1.00%,1.10%or 1.20%Ca for 21 days.Each diet contained the constant non-phytate phosphorus content of about 0.39%.Results:The average daily gain decreased linearly(P<0.001)as dietary Ca level increased.The serum and tibia alkaline phosphatase(ALP)activities,tibia bone mineral density(BMD),middle toe BMD,tibia ash percentage,tibia breaking strength,and tibia ALP protein expression level were affected(P<0.05)by dietary Ca level,and showed significant quadratic responses(P<0.02)to dietary Ca levels.The estimates of dietary Ca requirements were 0.80 to 1.00%based on the best fitted broken-line or quadratic models(P<0.03)of the above serum and bone parameters,respectively.Conclusions:The results from the present study indicate that the Ca requirements would be about 0.60%to obtain the best growth rate,and 1.00%to meet all of the Ca metabolisms and bone development of broilers fed a conventional corn-soybean meal diet from 1 to 21 days of age.
文摘随着人类社会的高速发展,在保证环境不被破坏的情况下维持众多机械和电气设备的正常运转急需清洁的能源方式。氢被认为是在未来最有前景的清洁能源之一。近期,电化学水分解已被认为是获取氢能的最有效的方法之一,它的燃料产物只是无污染的水;然而,迟缓的析氧反应严重制约了水分解效率,导致驱动水分解的电压相对较高。探求热力学有利的阳极反应以取代缓慢的氧析出和开发高活性双功能型电催化剂用于这种阳极反应和析氢对于实现可应用于工业的节能型产氢至关重要。当前,普遍认为用其他有用的且利于热力学的反应取代析氧反应可以减小分解电压从而实现节能产氢。本文报道了一种用于甲醇氧化和析氢的双功能型嵌入镍纳米粒子的碳棱柱状微米棒电催化剂(命名为镍碳微米棒),该催化剂是由74号金属有机框架结构经碳化处理获得。这种由镍和碳构成的界面材料结构通过原位碳化实现,由于碳的分隔作用,分散的镍纳米颗粒不会轻易团聚,这有利于暴露更多的镍活性位点与电解液相接触,为更快的催化剂和电解液间电荷转移和电化学动力学提供保障。在此阳极的甲醇氧化中,产物分别为二氧化碳和甲酸,两者在1.55 V电压下的法拉第效率分别为36.2%和62.5%;同时该镍碳微米棒催化剂表现出优异的甲醇氧化活性和耐久性(12 h持续性催化,电流仅衰退2.7%)。值得注意的是,该双功能催化剂不仅具有甲醇氧化活性,在室温下含有0.5mol·L^(-1)甲醇的1.0mol·L^(-1)氢氧化钾电解液中的析氢过电位也较低(仅155 m V的过电位即可驱动10 m A·cm^(-2)的电流),保证了产氢效率。更重要的是,采用这种双功能型电极构造的双电极电解槽仅需1.6 V电压即可驱动10 m A·cm^(-2)的电流,与析氧反应作为阳极反应的电解槽相比驱动电压减小了240 mV。
基金supported by the Key Program of the National Natural Science Foundation of China(project no.31630073,Beijing,P.R.China)the National Key R&D Program of China(project no.2017YFD0502200,Beijing,P.R.China)+1 种基金the China Agriculture Research System of MOF and MARA(project no.CARS-41,Beijing,P.R.China)the Agricultural Science and Technology Innovation Program(project no.ASTIPIAS09,Beijing,P.R.China).
文摘Background:Phosphorus is essential for bone mineralization in broilers,however,the underlying mechanisms remain unclear.We aimed to investigate whether bone phosphorus retention and bone development might be regulated by related hormones and local bone-derived regulators in broilers.Methods:Broilers were fed diets containing different levels of non-phytate phosphorus(NPP)0.15%,0.25%,0.35%,0.45% and 0.55% or 0.15%,0.22%,0.29%,0.36% and 0.43% from 1 to 21 or 22 to 42 days of age.Serum and tibia samples were collected for determinations of bone phosphorus retention and bone development parameters,related hormones and local bone-derived regulators of broiler chickens on d 14,28 and 42,respectively.Results:Tibia ash phosphorus,total phosphorus accumulation in tibia ash(TP_(TA)),bone mineral concentration(BMC),bone mineral density(BMD),bone breaking strength(BBS),and ash on d 14,28 or 42,serum 1,25-dihydroxyvitamin D_(3)(1,25(OH)_(2)D_(3))on d 28 and 42,mRNA expressions of tibia fibroblast growth factor 23(FGF23)and dentin matrix protein 1(DMP1)on d 14 and 28 increased linearly or quadratically(P<0.05),while serum parathyroid hormone(PTH)on d 28,tibia alkaline phosphatase(ALP)on d 14,28 and 42,bone gal protein(BGP)on d 14,and mRNA expression of tibia phosphate-regulating gene with homologies to endopeptidases on the X chromosome(PHEX)on d 14 and 28 decreased linearly or quadratically(P<0.04)as dietary NPP level increased.TPTA,BMC,BMD,and ash on d 28 and 42,BBS on d 28,and ash phosphorus on d 42 were positively correlated(r=0.389 to 0.486,P<0.03)with serum 1,25(OH)_(2)D_(3).All of the above parameters were positively correlated(r=0.380 to 0.689,P<0.05)with tibia DMP1 mRNA expression on d 14,28 and 42,but negatively correlated(r=−0.609 to−0.538,P<0.02)with serum PTH on d 28,tibia ALP on d 14,28 and 42,and BGP on d 14.TP_(TA),BMC and ash on d 14 and BMD on d 28 were negatively correlated(r=−0.397 to−0.362,P<0.03)with tibia PHEX mRNA expression,and BMD on d 28 was positively correlated(r=0.384,P=0.04)with tibia FGF23 mRNA expression.Conclusions:These results suggested that bone phosphorus retention and bone development parameters had moderate to strong correlations with serum PTH and 1,25(OH)2D3 and tibia DMP1,PHEX,FGF23,ALP and BGP in broilers during the whole growth period,and thus they might be partly regulated by these related hormones and local bone-derived regulators.
基金the National Key R&D Program of China(Grant Nos.2016YFB0400102 and 2016YFB0400602)the National Natural Science Foundation of China(Grant Nos.61674076,61422401 and 51461135002)+2 种基金the Collaborative Innovation Center of Solid State Lighting and Energy-Saving Electronics,Open Fund of the State Key Laboratory on Integrated Optoelectronics(Grant No.IOSKL2017KF03)the Natural Science Foundation for Young Scientists of Jiangsu Province of China(Grant No.BK20160376)the Research Funds from NJU-Yangzhou Institute of Opto-electronics,and the Research and Development Funds from State Grid Shandong Electric Power Company and Electric Power Research Institute.
文摘Resonance effects caused by the photon-electron interaction are a focus of attention in semiconductor optoelectronics,as they are able to increase the efficiency of emission.GaN-on-silicon microdisks can provide a perfect cavity structure for such resonance to occur.Here we report GaN-based microdisks with different diameters,based on a standard blue LED wafer on a Si substrate.A confocal photoluminescence spectroscopy is performed to analyze the properties of all microdisks.Then,we systematically study the effects of radial modes and axial modes of these microdisks on photon-electron coupling efficiency by using three-dimensional finite-difference time-domain simulations.For thick microdisks,photon-electron coupling efficiency is found to greatly depend on the distributions of both the radial modes and the axial modes,and the inclined sidewalls make significant influences on the axial mode distributions.These results are important for realization of high-efficiency resonant emission in GaN-based microcavity devices.
文摘This paper is to provide an empirical work for agricultural spatial distribution of agriculture. We consider the spatial location pattern in order to offer spatial views on the agricultural economic research and how Chinese agricultural economic spatial location pattern is forming, we also tested the agglomeration situation of agriculture and the process is going on in the future. The results indicate that the periphery areas exist significant differential among regions in Hunan province, China. It really presents some kinds of agglomeration pattern of agriculture and characteristic spatial autocorrelation;the biggest rate of contribution to the region agriculture economic gap is productivity per agriculture worker.
基金supported by Jiangsu Shuang Chuang Tuan Dui program(JSSCTD202147)Jiangsu Shuang Chuang Ren Cai program(JSSCRC2021541)+1 种基金Young Elite Scientists Sponsorship Program by CAST(2022QNRC001)the Initiation Funds of Yangzhou University for Distinguished Scientists
文摘This research was to assess the dietary copper(Cu)requirement of broiler chickens fed a practical cornsoybean meal diet during 22—42 d of age.A total of 288 numbered Arbor Acres male broilers at 22 d of age were randomly allotted 6 treatments with 8 replicate cages(6 broilers per cage)per treatment.Broilers were fed a Cu-unsupplemented corn-soybean meal basal diet(control,containing 7.36 mg Cu/kg)or the basal diet added with 3,6,9,12,or 15 mg Cu/kg from CuSO_(4)·5H_(2)O for 21 d.Quadratic,asymptotic and broken-line models were fitted and the best fitted models were selected to determine dietary Cu requirements.The results revealed that the contents of Cu in serum and liver,m RNA expression levels of Cu-and zinc-containing superoxide dismutase(CuZnSOD)in liver and monoamine oxidase b(MAO B)in heart,as well as protein expression level of CuZnSOD in liver were affected(P<0.05)by supplemental Cu levels,and the above indices varied linearly and quadratically(P<0.05)with increasing Cu levels.Dietary Cu requirements assessed according to the best fitted broken-line models(P<0.05)of the above indexes were 10.45—13.81 mg/kg.It was concluded that mRNA expression levels of CuZnSOD in liver and MAO B in heart,as well as liver CuZnSOD protein expression level were new specific sensitive biomarkers for estimating dietary Cu requirements,and the dietary Cu requirement was recommended to be 14 mg/kg to support Cu metabolic needs related to key Cucontaining enzymes in broilers fed the corn-soybean meal diet during 22—42 d of age,which was higher than the dietary Cu requirement(8 mg/kg)for broilers at the corresponding stage suggested by the Chinese Feeding Standard of Chicken.
基金Supported by the National Development and Reform Commission and Ministry of Finance of China.
文摘From the viewpoint of earth system science,this paper discusses the observation capability of the second-generation of Chinese polar-orbiting,sun-synchronous operational meteorological satellite observation systems,Fengyun-3(FY-3),based on the function and performance test results from the FY-3 D satellite observation system in orbit.The FY-3 series of satellites have numerous remote sensing instruments and a wide range of imaging and sounding electromagnetic spectrometers onboard.These instruments can obtain reflectivity data for land surface,soil,vegetation,water body,snow cover,ocean color,and sea ice on earth’s surface over a wide spectral range,as well as information on the absorption and scattering radiative transfer of molecules and particles(clouds and aerosols)in earth’s atmosphere.All of these data can be used to retrieve physical and chemical information about the land,ocean,and atmosphere of the earth system.Comprehensive observation of the earth system by the FY-3 meteorological satellites is preliminarily realized.
基金supported by the National Natural Science Foundation of China(project no.31601956)the Agricultural Science and Technology Innovation Program(project no.ASTIPIAS09)the China Agriculture Research System of MOF and MARA(project no.CARS-41)。
文摘The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers is primarily based on growth performance data reported in 1986.Our study aimed to determine optimal dietary Se levels of broilers fed a practical corn-soybean meal diet for the full expression of selenoproteins in various tissues.A total of 384 one-d-old male broilers(n=8 replicates/diet)were fed a basal corn-soybean meal diet or the basal diet supplemented with 0.1,0.2,0.3,0.4 or 0.5 mg Se/kg in the form of Na_(2)SeO_(3) for 21 d.Regression analysis was conducted to evaluate the optimal dietary Se levels using broken-line,quadratic or asymptotic models.The activity of glutathione peroxidase(GPX)in the plasma,liver,kidney and pancreas,iodothyronine deiodinase(DIO)in the plasma,liver and pancreas,and thioredoxin reductase(Txnrd)in the liver and pancreas,the mRNA levels of Gpx1,Gpx4,Dio1,selenoprotein(Seleno)h,Selenop and Selenou in the liver,Gpx4,Dio1,Txnrd1,Txnrd2,Selenoh,Selenop and Selenou in the kidney,and Gpx1,Gpx4,Selenoh and Selenou in the pancreas,and the protein levels of GPX4 in the liver and kidney of broilers were influenced(P<0.05)by added Se levels,and increased quadratically(P<0.05)with the increase of added Se levels.The estimates of optimal dietary Se levels were 0.07 to 0.36 mg/kg based on the fitted broken-line,quadratic or asymptotic models(P<0.001)of the aforementioned selenoprotein expression in the plasma,liver and kidney,and 0.09 to 0.46 mg/kg based on the fitted broken-line models(P<0.001)of the aforementioned selenoprotein expression in the pancreas.The results indicate that the optimal dietary Se levels would be 0.36 mg/kg to support the full expression of selenoproteins in the plasma,liver and kidney,and 0.46 mg/kg to support the full expression of selenoproteins in the pancreas of broilers fed a practical corn-soybean meal diet from 1 to 21 d of age.
基金supported by the Key International Cooperation Program of the National Natural Science Foundation of China(project no.31110103916,Beijing,China)the National Natural Science Foundation of China(project no.31972583,Beijing,China)+1 种基金the China Agricultural Research System(project no.CARS-41,Beijing,China)the Agricultural Science and Technology Innovation Program(ASTIP-IAS09,Beijing,China)
文摘Zinc(Zn)has been shown to attenuate the adverse effects of heat stress on broilers,but the mechanisms involving this process remain unclear.We aimed to investigate possible protective mechanisms of Zn on primary cultured hepatocytes of broiler embryos subjected to heat stress.Three experiments were conducted.In Exp.1,hepatocytes were treated with 0,50,100,200,or 400μmol/L added Zn as inorganic Zn sulfate(iZn)for 12,24 or 48 h.In Exp.2,cells were exposed to 40℃(a normal temperature[NT])and 44℃(a high temperature[HT])for 1,2,4,6,or 8 h.In Exp.3,cells were preincubated with 0 or 50μmol/L Zn as iZn or organic Zn lysine chelate(oZn)for 8 h under NT,and then incubated with the same Zn treatments under NT or HT for 4 or 6 h.The biomarkers of antioxidative status and heat stress in cells were measured.The results in Exp.1 indicated that 50μmol/L Zn and 12 h incubation were the optimal conditions for increasing antioxidant ability of hepatocytes.In Exp.2,the 4 or 6 h incubation under HT was effective in inducing heat shock responses of hepatocytes.In Exp.3,HT elevated(P<0.01)malondialdehyde content and expressions of heat shock protein 70(HSP70)mRNA and protein,as well as HSP90 mRNA.However,Zn supplementation increased(P<0.05)copper zinc superoxide dismutase(CuZnSOD)activity and metallothionein mRNA expression,and effectively decreased(P<0.05)the ex-pressions of HSP70 mRNA and protein,as well as HSP90 mRNA.Furthermore,oZn was more effective(P<0.05)than iZn in enhancing CuZnSOD activity of hepatocytes under HT.It was concluded that Zn(especially oZn)could alleviate heat stress of broiler hepatocytes via enhancing their antioxidant ability and attenuating heat shock responses.
基金The present study was supported by the National Natural Science Foundation of China(project no.31601956)the Agricultural Science and Technology Innovation Program(project no.ASTIPIAS09)the China Agriculture Research System of MOF and MARA(project no.CARS-41).
文摘The current NRC dietary selenium(Se)requirement(0.15 mg/kg)of broilers from 22 to 42 d of age is primarily based on a previous study reported in 1986,which might not be applicable to modern classes of rapidly growing broilers.The present experiment was conducted to determine the optimal dietary Se level for meeting metabolic and functional Se requirements of broilers fed a corn-soybean meal diet from 22 to 42 d of age.A total of 336 Arbor Acres male broilers at 22 d old were randomly assigned to 1 of 6 treatments with 7 replicates and fed a basal corn-soybean meal diet(control,containing 0.014 mg Se/kg)and the basal diet supplemented with 0.10,0.20,0.30,0.40,or 0.50 mg Se/kg from Na_(2)SeO_(3) for 21 d.The results showed that the Se concentrations in plasma,liver,kidney,pancreas,breast and thigh muscles,the activity of glutathione peroxidase(GPX)in plasma,liver and kidney,the mRNA expression levels of Gpx4,selenoprotein(Seleno)h and Selenou in liver,Selenop and Selenoh in kidney,and the protein expression levels of GPX4 in the liver and kidney of broilers were affected(P<0.05)by supplemental Se level,and increased quadratically(P<0.05)with the increase of supplemental Se level.The estimates of optimal dietary Se levels were 0.10 to 0.49 mg/kg based on the fitted broken-line or asymptotic models(P<0.0001)of the above Se concentration indices,and 0.08 to 0.37 mg/kg based on the fitted brokenline,quadratic or asymptotic models(P<0.007)of the above selenoprotein expression indices.These results indicate that the optimal dietary Se levels would be 0.49 mg/kg to support the maximum Se concentrations and 0.37 mg/kg to support the full expression of selenoproteins in plasma and various tissues of broilers fed a corn-soybean meal diet from 22 to 42 d of age.
基金the National Natural Science Foundation of China(project number 31672440,Beijing,China)the Research Program of State Key Laboratory of Animal Nutrition(project number 2004DA125184G1606,Beijing,China)+1 种基金the Agricultural Science and Technology Innovation Program(ASTIP-IAS09,Beijing,China)the China Agriculture Research System of MOF and MARA(project number CARS-41,Beijing,China).
文摘No information is available regarding the utilization of iron (Fe) from different Fe sources at a targettissue level. To detect differences in Fe metabolic utilization among Fe sources, the effect of intravenouslyinjected Fe on growth performance, hematological indices, tissue Fe concentrations and Fe-containingenzyme activities and gene expressions of Fe-containing enzymes or protein in broilers was investigated.On d 22 post-hatching, a total of 432 male chickens were randomly allotted to 1 of 9 treatments ina completely randomized design. Chickens were injected with either a 0.9% (wt/vol) NaCl solution(control) or a 0.9% NaCl solution supplemented with Fe sulphate or 1 of 3 organic Fe sources. The 3organic Fe sources were Fe chelates with weak (Fe-MetW), moderate (Fe-ProtM) or extremely strong (Fe-ProtES) chelation strength. The 2 Fe dosages were calculated according to the Fe absorbabilities of 10%and 20% every 2 d for a duration of 20 d. Iron injection did not affect (P > 0.05) ADFI, ADG or FCR duringeither 1 to 10 d or 11 to 20 d after injections. Hematocrit and Fe concentrations in the liver and kidney ond 10 after Fe injections, and Fe concentrations in the liver or pancreas and ferritin heavy-chain (FTH1)protein expression level in the liver or spleen on d 20 after Fe injections increased (P≤0.05) as injectedFe dosages increased. When the injected Fe level was high at 20% Fe absorbability, the chickens injectedwith Fe-ProtES had lower (P < 0.001) liver or kidney Fe concentrations and spleen FTH1 protein levelsthan those injected with Fe-MetW or Fe-ProtM on d 20 after injections. And they had lower (P < 0.05)liver cytochrome C oxidase mRNA levels on d 20 after injections than those injected with Fe-MetW or Fesulphate. The results from this study indicate that intravenously injected Fe from Fe-ProtES was the least utilizable and functioned in the sensitive target tissue less effectively than Fe from Fe sulfate, Fe-MetW or Fe-ProtM.
基金This work was funded by the National Natural Science Foundation of China(52041701)Tsinghua University-Peking Union Medical College Hospital Initiative Scientific Research Programme(20191080604)Tsinghua University Spring Breeze Fund(2020Z99CFG007).
文摘In this work,the air dielectric barrier discharge plasma was applied to a model of protein human serum albumin to explore plasma‐mediated protein damage from a biomolecular perspective.Carbonylation and side chain modifications of protein in solution were observed by Fourier transform infrared(FT‐IR)spectroscopy and mass spectrometry(MS).Protein backbone cleavage is proved by Bradford assay,sodium dodecyl sulphate–polyacrylamide gel electrophoresis,and MS.Typical fragments are in the range of 10–12 kDa.The decrease inα‐helix and increase inβ‐sheet indicated by FT‐IR are major protein secondary structure changes.Accordingly,a whole map of protein oxidative damage and structural changes in response to the plasma was postulated.
基金Supported by the National Key Research and Development Program of China(2018YFB0504905 and 2018YFB0504900)。
文摘The visible infrared radiometer(VIRR)is the first instrument with longest measurements equipped on the Fengyun(FY)polar-orbiting satellites.Through re-processing of the historic VIRR measurements,long-term(over 20 yr)global data can be integrated from multiple participating VIRRs on a consistent radiometric scale,which are valuable to climate and climate change studies.Due to lack of an onboard calibration system for VIRR,the reflective solar bands must be vicariously calibrated.This study applied the multi-site vicarious approach for consistent calibration of the VIRR visible(VIS)and near-infrared(NIR)data,and produced calibration coefficients for five VIRRs on FY-1 C/D and FY-3 A/B/C.The data quality was then evaluated with observations.The reflectance predicted by using the radiative transfer model over multiple invariant desert and ocean targets was used to derive the calibration slope via a weighted fitting scheme,in which the weights are the inverse of the variance from a radiative transfer simulation evaluated with reference to Aqua moderate resolution imaging spectroradiometer(MODIS).The sensor-specific calibration coefficients were derived on a daily basis by using piecewise polynomials.The calibration reference of the VIRR solar band record was further traced to the Aqua MODIS Collection 6.1 reference calibration with a systematic correction derived from the Libya4 desert.The VIRR record was compared with the Aqua MODIS C6.1 calibration over the polar region based on simultaneous nadir overpass observations.The lifetime relative difference for each sensor are within 3.3%and 4.5%for channels 1 and 2.Invariant deserts were also employed to evaluate the stability and consistency of the VIRR record.In general,the means of the directional and spectral corrected reflectance for each sensor are within 1%of the 20-yr average,implying that the VIRR reflectance of the invariant targets is consistent to within 1%among the sensors for channels 1 and 2.The VIRR data thus derived are reliable.
基金This work was supported by the China Agriculture Research System of MOF and MARA(CARS-41)the Agricultural Science and Technology Innovation Program(ASTIP-IAS09)+2 种基金the Key Program of the National Natural Science Foundation of China(31630073)the National Natural Science Foundation of China(31972583)the Earmarked Fund for Hebei Chicken Innovation Team of Modern Agro-industry Technology Research System(HBCT2018150203,HBCT2018150206).
文摘The current dietary copper(Cu)requirement(8 mg/kg)of broilers is mainly based on growth,hemoglobin concentration,or hematocrit,which might not be the most sensitive indices to evaluate dietary Cu requirements of broilers.The present study was carried out to estimate dietary Cu requirements of broilers fed a conventional corn-soybean meal diet from 1 to 21 d of age using biochemical or molecular biomarkers.A total of 3841-d-old Arbor Acres male broilers were randomly allocated to 1 of 6 treatments with 8 replicates and fed a Cu-unsupplemented corn-soybean meal basal diet containing 5.17 mg Cu/kg by analysis and the basal diet supplemented with 3,6,9,12 or 15 mg Cu/kg as CuSO4,5H2O for 21 d.Regression analysis was performed to estimate the optimal dietary Cu level using the broken-line model.Dietary supplemental Cu level affected(P<0.05)Cu contents in serum and liver and kidney monoamine oxidase(MAO)activity,but had no effects(P>0.05)on the growth performance,Cu contents in heart,kidney,pancreas and spleen,Cu-and zinc-containing superoxide dismutase(CuZnSOD)activity and ceruloplasmin content in serum,CuZnSOD and cytochrome c oxidase(COX)activities and ceruloplasmin,CuZnSOD,MAO A,MAO B,COX 4I1 and COX 1 mRNA and protein expressions in the above tissues of broilers.As dietary supplemental Cu levels increased,Cu contents in serum and liver increased linearly(P<0.05),but kidney MAO activity decreased linearly and quadratically(P<0.05).The estimated dietary Cu requirement based on the fitted broken-line model(P=0.035)of kidney MAO activity was 11.30 mg/kg.In conclusion,kidney MAO activity is a new and sensitive criterion to evaluate the dietary Cu requirement of broilers,and the dietary Cu requirement was 11.30 mg/kg for broilers fed the conventional corn-soybean meal diet from 1 to 21 d of age,which is higher than the current National Research Council(NRC)Cu requirement(8 mg/kg)of broilers.
基金funded by the National Key Basic Research Program of China(2013CB429806)
文摘New U-Pb zircon geochronology data suggest that the Yintun Formation is younger man ~ 1895 Ma and is late Paleoproterozoic.The Yintun Formation may represent the first sedimentary cover of the North China Craton(NCC)based on its stratigraphic sequence and the ages of its sediments.Gravels in the conglomerates from the lower member of the Yintun Formation are characterized by obvious glacial origins.It is possible that these glacial gravels are the re-deposited sedimentary products of the Huronian Glaciation from the Indian continent.This can also provide sedimentary evidence for the relative location of the Indian continent and the NCC in the reconstruction of the Columbia supercontinent.
