Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between bu...Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between butyrate and forskolin(a natural labdane diterpene)in enhancing innate host defense,barrier function,disease resistance,growth performance,and meat quality of broilers.Methods:The expressions of representative genes involved in host defense(AvBD9 and AvBD10),barrier function(MUC2,CLDN1,and TJP1),and inflammation(IL-1β)were measured in chicken HD11 macrophages in response to butyrate and forskolin in the presence or absence of bacterial lipopolysaccharides(LPS).Intestinal lesions and the Clostridium perfringens titers were also assessed in C.perfringens-challenged chickens fed butyrate and forskolincontaining Coleus forskohlii(CF)extract individually or in combination.Furthermore,growth performance and carcass characteristics were evaluated in broilers supplemented with butyrate and the CF extract for 42 d.Results:Butyrate and forskolin synergistically induced the expressions of AvBD9,AvBD10,and MUC2 in chicken HD11 cells(P<0.05)and the synergy was maintained in the presence of LPS.Butyrate and forskolin also suppressed LPS-induced IL-1βgene expression in HD11 cells in a synergistic manner(P<0.05).The two compounds significantly reduced the intestinal lesions of C.perfringens-challenged chickens when combined(P<0.05),but not individually.Furthermore,butyrate in combination with forskolin-containing CF extract had no influence on weight gain,but significantly reduced feed intake(P<0.05)with a strong tendency to improve feed efficiency(P=0.07)in a 42-d feeding trial.Desirably,the butyrate/forskolin combination significantly decreased abdominal fat deposition(P=0.01)with no impact on the carcass yield,breast meat color,drip loss,or pH of d-42 broilers.Conclusions:Butyrate and forskolin has potential to be developed as novel antibiotic alternatives to improve disease resistance,feed efficiency,and carcass composition of broilers.展开更多
Background: Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2(TLR2) is important for host recognition of invad...Background: Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2(TLR2) is important for host recognition of invading Grampositive microbes. Over-expression of TLR2 in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.Methods: We over-expressed TLR2 in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria,triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from the TLR2-positive transgenic goats, and induced over-expression of activator protein-1(AP-1), phosphatidylinositol 3-kinase(PI3K) and transcription factor nuclear factor kappa B(NF-κB) and inflammation factors downstream of the signal pathway.Results: Compared with wild-type controls, measurements of various oxidative stress-related molecules showed that TLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased m RNA levels of transcription factor NF-E2-related factor-2(Nrf2) and the downstream gene, heme oxygenase-1(HO-1). When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.Conclusions: The results indicate that the oxidative injury in goats over-expressing TLR2 was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation gene HO-1 by activation of the Nrf2 signal pathway.展开更多
A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this...A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this paper,the stress analysis of the main cable is carried out,and the relationship between the slope change and the coordinate change is found.This paper also discussed how to find the minimum slope point of symmetrical or asymmetric main cable,and the deformation compatibility equation is established and solved to obtain the shape of main cable.The algorithm in this paper can ensure the convergence of the solution for the suspension bridge with spatial cables.The calculation accuracy is high through the demonstration of the calculation examples.展开更多
In surface-enhanced Raman scattering(SERS),flexible substrate plays an important role in target molecular collection from various shape surfaces and increases the analytical sensitivity.In this study,silver nanopartic...In surface-enhanced Raman scattering(SERS),flexible substrate plays an important role in target molecular collection from various shape surfaces and increases the analytical sensitivity.In this study,silver nanoparticles(Ag NPs)were deposited on a non-woven fabric used as an SERS substrate by self-assembly,in situ growing or the self-assembly/in situ growing combination method.4-Aminothiophenol was selected as a model molecular for the evaluation of the SERS performance using the substrates.The Ag NPs substrate prepared by self-assembly/in situ growing method presented the best Raman enhancement effect and its enhancement factor was estimated as high as 3.59106.The substrate was applied to the determination of four pesticide residues on the surfaces of fruit samples through wipe sampling,and the results revealed the good reproducibility of SERS responses and high detection sensitivity.The prepared flexible substrate was simple to fabricate and environmentally friendly.It could be expected to be a useful tool in rapid on-site test of pesticide residues on fruit surfaces because of its high sensitivity,convenience and non-destructive characteristics.展开更多
In this paper, influence of temperature and reverse bias on photocurrent spectrum and spectral response of a monolithic GalnP/GaAs double-junction solar cell was investigated in detail. Two sharp spectral response off...In this paper, influence of temperature and reverse bias on photocurrent spectrum and spectral response of a monolithic GalnP/GaAs double-junction solar cell was investigated in detail. Two sharp spectral response offsets, corresponding to the bandedge photo absorption of the bottom GaAs and the top GalnP subcells, respectively, show the starting response points of individual subcells. More interestingly, the cell photocurrent was found to enhance significantly with increasing the temperature. In addition, the cell photocurrent also increases obviously as the reverse bias voltage increases. The integrated photocurrent intensity of the top GalnP subcell was particularly addressed. A theoretical model was proposed to simulate the reverse bias dependence of the integrated photocurrent of the GalnP subceU at different temperatures.展开更多
基金supported by the USDA National Institute of Food and Agriculture (grant no. 2018–68003-27462 and 2020–67016-31619)Oklahoma Center for the Advancement of Science and Technology (grant no. AR19–027)+2 种基金Boulware Endowment FundOklahoma Agricultural Experiment Station Project H-3112supported by the USDA-NIFA Predoctoral Fellowship grant 2018–67011-28041
文摘Background:The emergence of antimicrobial resistance has necessitated the development of effective alternatives to antibiotics for livestock and poultry production.This study investigated a possible synergy between butyrate and forskolin(a natural labdane diterpene)in enhancing innate host defense,barrier function,disease resistance,growth performance,and meat quality of broilers.Methods:The expressions of representative genes involved in host defense(AvBD9 and AvBD10),barrier function(MUC2,CLDN1,and TJP1),and inflammation(IL-1β)were measured in chicken HD11 macrophages in response to butyrate and forskolin in the presence or absence of bacterial lipopolysaccharides(LPS).Intestinal lesions and the Clostridium perfringens titers were also assessed in C.perfringens-challenged chickens fed butyrate and forskolincontaining Coleus forskohlii(CF)extract individually or in combination.Furthermore,growth performance and carcass characteristics were evaluated in broilers supplemented with butyrate and the CF extract for 42 d.Results:Butyrate and forskolin synergistically induced the expressions of AvBD9,AvBD10,and MUC2 in chicken HD11 cells(P<0.05)and the synergy was maintained in the presence of LPS.Butyrate and forskolin also suppressed LPS-induced IL-1βgene expression in HD11 cells in a synergistic manner(P<0.05).The two compounds significantly reduced the intestinal lesions of C.perfringens-challenged chickens when combined(P<0.05),but not individually.Furthermore,butyrate in combination with forskolin-containing CF extract had no influence on weight gain,but significantly reduced feed intake(P<0.05)with a strong tendency to improve feed efficiency(P=0.07)in a 42-d feeding trial.Desirably,the butyrate/forskolin combination significantly decreased abdominal fat deposition(P=0.01)with no impact on the carcass yield,breast meat color,drip loss,or pH of d-42 broilers.Conclusions:Butyrate and forskolin has potential to be developed as novel antibiotic alternatives to improve disease resistance,feed efficiency,and carcass composition of broilers.
基金supported by grants from National Transgenic Creature Breeding Grand Project(2014ZX08008-005)Chinese Universities Scientific Fund(2014BH032)Natural Science Foundation of China(31501953, 31471352, 31471400 and 31171380)
文摘Background: Mastitis, an infection caused by Gram-positive bacteria, produces udder inflammation and oxidative injury in milk-producing mammals. Toll-like receptor 2(TLR2) is important for host recognition of invading Grampositive microbes. Over-expression of TLR2 in transgenic dairy goats is a useful model for studying various aspects of infection with Gram-positive bacteria, in vivo.Methods: We over-expressed TLR2 in transgenic dairy goats. Pam3CSK4, a component of Gram-positive bacteria,triggered the TLR2 signal pathway by stimulating the monocytes-macrophages from the TLR2-positive transgenic goats, and induced over-expression of activator protein-1(AP-1), phosphatidylinositol 3-kinase(PI3K) and transcription factor nuclear factor kappa B(NF-κB) and inflammation factors downstream of the signal pathway.Results: Compared with wild-type controls, measurements of various oxidative stress-related molecules showed that TLR2, when over-expressed in transgenic goat monocytes-macrophages, resulted in weak lipid damage, high level expression of anti-oxidative stress proteins, and significantly increased m RNA levels of transcription factor NF-E2-related factor-2(Nrf2) and the downstream gene, heme oxygenase-1(HO-1). When Pam3CSK4 was used to stimulate ear tissue in vivo the HO-1 protein of the transgenic goats had a relatively high expression level.Conclusions: The results indicate that the oxidative injury in goats over-expressing TLR2 was reduced following Pam3CSK4 stimulation. The underlying mechanism for this reduction was increased expression of the anti-oxidation gene HO-1 by activation of the Nrf2 signal pathway.
文摘A new algorithm is proposed to solve the problems of shape-finding of suspension bridge with spatial cables what include tedious iteration,slow convergence speed and even no convergent under some circumstances.In this paper,the stress analysis of the main cable is carried out,and the relationship between the slope change and the coordinate change is found.This paper also discussed how to find the minimum slope point of symmetrical or asymmetric main cable,and the deformation compatibility equation is established and solved to obtain the shape of main cable.The algorithm in this paper can ensure the convergence of the solution for the suspension bridge with spatial cables.The calculation accuracy is high through the demonstration of the calculation examples.
基金Natural Science Foundation of Fujian Province(No.2015J01058)and NFFTBS(No.J1310024)which are gratefully acknowledged.
文摘In surface-enhanced Raman scattering(SERS),flexible substrate plays an important role in target molecular collection from various shape surfaces and increases the analytical sensitivity.In this study,silver nanoparticles(Ag NPs)were deposited on a non-woven fabric used as an SERS substrate by self-assembly,in situ growing or the self-assembly/in situ growing combination method.4-Aminothiophenol was selected as a model molecular for the evaluation of the SERS performance using the substrates.The Ag NPs substrate prepared by self-assembly/in situ growing method presented the best Raman enhancement effect and its enhancement factor was estimated as high as 3.59106.The substrate was applied to the determination of four pesticide residues on the surfaces of fruit samples through wipe sampling,and the results revealed the good reproducibility of SERS responses and high detection sensitivity.The prepared flexible substrate was simple to fabricate and environmentally friendly.It could be expected to be a useful tool in rapid on-site test of pesticide residues on fruit surfaces because of its high sensitivity,convenience and non-destructive characteristics.
基金This work was financially supported by the National Natural Science Foundation of China (Grant No. 11374247)
文摘In this paper, influence of temperature and reverse bias on photocurrent spectrum and spectral response of a monolithic GalnP/GaAs double-junction solar cell was investigated in detail. Two sharp spectral response offsets, corresponding to the bandedge photo absorption of the bottom GaAs and the top GalnP subcells, respectively, show the starting response points of individual subcells. More interestingly, the cell photocurrent was found to enhance significantly with increasing the temperature. In addition, the cell photocurrent also increases obviously as the reverse bias voltage increases. The integrated photocurrent intensity of the top GalnP subcell was particularly addressed. A theoretical model was proposed to simulate the reverse bias dependence of the integrated photocurrent of the GalnP subceU at different temperatures.