Two soils, one consisting of 1:1 clay minerals at pH 4.5 and the other containing 2:1 clay minerals at pH 7.0, were used to estimate the conversion of added NH+4 under different C/N ratios (glucose as the C source) an...Two soils, one consisting of 1:1 clay minerals at pH 4.5 and the other containing 2:1 clay minerals at pH 7.0, were used to estimate the conversion of added NH+4 under different C/N ratios (glucose as the C source) and the addition of potassium. Under lower C/N ratios (0:1 and 5:1), a large part of the added NH4+ in the acid soil was held in the forms of either exchangeable or water soluble NH4+ for a relatively long time and under higher C/N ratio (50:1), a large amount of the added NH4+ was directly immobilized by microorganisms. In the second soil containing appreciable 2:1 type clay minerals a large part of the added NH+4 at first quickly entered the interlayer of the minerals under both lower and higher C/N ratios. In second condition, however, owing to microbial assimilation stimulated by glucose the newly fixed NH4+c ould be completely released in further incubation because of a large concentration gradient between external NH4+ and fixed NH4+ in the mineral interlayer caused by heterotrophic microorganisms, which imply the fixed NH4+ to be available to plants. The results also showed that if a large amount of K+ with carbon source together was added to soil, the higher K+ concentration of soil solution could impede the release of fixed NH4+ , even if there was a lot of carbon source.展开更多
Co and Mo bimetallic nitrides supported on Mg(Al)O, MgO and γ-Al2O3 were prepared in temperatureprogrammed reactions with NH3. The surface morphology, chemical composition and catalytic activity for NH3 decompositi...Co and Mo bimetallic nitrides supported on Mg(Al)O, MgO and γ-Al2O3 were prepared in temperatureprogrammed reactions with NH3. The surface morphology, chemical composition and catalytic activity for NH3 decomposition on the supported Co and Mo bimetallic nitrides were studied by X-ray diffractometer (XRD), NH3 temperature-programmed desorption and mass spectrometer (NH3-TPD-MS), temperature-programmed desorption and mass spectrometer (TPD-MS), H2 temperature-programmed surface reaction (H2-TPSR) and activity test. The phases of Co3Mo3N and MoN could be formed on Mg(Al)O, MgO and Al2O3 during the nitridation, and they might be more uniformly dispersed on Mg(Al)O and MgO than on γ-Al2O3. Transition metallic nitrides are generally considered as potential catalysts for hydrogen-involving reactions due to the entrance of hydrogen atoms into subsurface and the lattice of metallic nitrides. The diffusion of nitrogen in the bulk and the structure transformation of Co and Mo nitride compounds occur during NH3-TPD, but the supported Co and Mo bimetallic nitrides are not easily reduced at H2 atmosphere. Co3Mo3N/Mg(Al)O catalyst exhibits the highest activity, while Co3Mo3N/Al2O3 exhibits the lowest activity for NH3 decomposition. Furthermore, the catalytic activity of Co and Mo bimetallic nitrides is not only much higher than that of supported single metallic nitride, but also highly dependent upon the surface acidity and BET surface area of support.展开更多
AIM: To study the effects of endogeous nitric oxide induced by 5-fluorouracil (5-FU) and L-arginine (L-Arg) on the human liver carcinoma model in nude mice. METHODS: The human liver carcinoma model in nude mice ...AIM: To study the effects of endogeous nitric oxide induced by 5-fluorouracil (5-FU) and L-arginine (L-Arg) on the human liver carcinoma model in nude mice. METHODS: The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline (NS), 5-FU and 5-FU + L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling (TUNEL) method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide (NO) in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS: 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU+L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively (P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group). The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU + L-Arg group (X^2= 15.963, P 〈 0.05). The apoptosis indexes were as follows: NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% (P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU). The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION: 5-FU combined with L-Arg can inhibit the growth of tumor in nude mice. The effect may be related to inducing the synthesis and increasing the activity of iNOS. The production of NO is increased, and it can enhance the expression of apoptosis-related gene and antioncogene.展开更多
The complex [Cu2(apo)4Cl4]·2H2O (apo=2-aminopyridine N-oxide) was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound (Cu2C20H28Cl4N8O6). The coordination geometry about e...The complex [Cu2(apo)4Cl4]·2H2O (apo=2-aminopyridine N-oxide) was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound (Cu2C20H28Cl4N8O6). The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2(apo)4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550(7), b = 8.5378(7), c = 12.082(1) ?, α = 72.807(1), β = 77.641(1), γ = 70.800(1)(, V =724.85(11) ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F(000) =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ(I). The distances between Cu(II) and O atoms are in the range from 1.934(2) to 2.042(2)?. The distance between two copper atoms Cu-Cu(A) is 3.2978(8) ?. The distances of Cu-Cl(1) and Cu-Cl(2) are 2.2322(9), 2.5095(10) ?, respectively. There is no evident hydrogen bond between N and Cl.展开更多
On the base of benzo [b] furo benzotriazoles several derivatives with expected biological activity were synthesized by alkylation and Mannich reactions. In the alkylation of ethyl iodide benzo [b] furo benzotriazoles ...On the base of benzo [b] furo benzotriazoles several derivatives with expected biological activity were synthesized by alkylation and Mannich reactions. In the alkylation of ethyl iodide benzo [b] furo benzotriazoles received 1-ethyl-benzo [b] furo [3,2-g] benzotriazole and 3-ethyl-benzo [b] furo [2,3-f] benzotriazole. Aminometilirization Mannich reaction conditions with "the application as amino compound diethylamine, morpholine and piperazine of benzo [b] furo benzotriazoles were received (N, N-diethylaminomethyl), CN-morpholinometil) and (N-piperazinometil)-derivatives.展开更多
This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature....This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature. Five different methods, namely, mechanical mixing, impregnation,hydrothermal treatment, co‐precipitation, and a sol‐gel technique, were used to synthesizeMnOx‐CeO2 catalysts. The catalysts were characterized in detail, and an NH3‐SCR model reaction waschosen to evaluate the catalytic performance. The results showed that the preparation methodsaffected the catalytic performance in the order: hydrothermal treatment > sol‐gel > co‐precipitation> impregnation > mechanical mixing. This order correlated with the surface Ce3+ and Mn4+ content,oxygen vacancies and surface adsorbed oxygen species concentration, and the amount of acidic sitesand acidic strength. This trend is related to redox interactions between MnOx and CeO2. The catalystformed by a hydrothermal treatment exhibited excellent physicochemical properties, optimal catalyticperformance, and good H2O resistance in NH3‐SCR reaction. This was attributed to incorporationof Mnn+ into the CeO2 lattice to form a uniform ceria‐based solid solution (containing Mn‐O‐Cestructures). Strengthening of the electronic interactions between MnOx and CeO2, driven by thehigh‐temperature and high‐pressure conditions during the hydrothermal treatment also improved the catalyst characteristics. Thus, the hydrothermal treatment method is an efficient and environment‐friendly route to synthesizing low‐temperature denitrification (deNOx) catalysts.展开更多
By the reaction of poly(bromoacetyl styrene) (EBPS) with thiaurea (TU), a kind of novel chelating resin with heterocyaclic ring of sulfur and nitrogen, poly[4-(2-amino)thiazoleyl-4- vinylbenzene], was synthesized. Its...By the reaction of poly(bromoacetyl styrene) (EBPS) with thiaurea (TU), a kind of novel chelating resin with heterocyaclic ring of sulfur and nitrogen, poly[4-(2-amino)thiazoleyl-4- vinylbenzene], was synthesized. Its structure was characterized by FTIR and elemental analysis. The factors which have influence on the reaction such as reaction time, solvents, and molar ratio of reactants were investigated.展开更多
A new series of azo were derived from 2,5-di(p-amino phenyl)-3,6-diphenyl pyrazine in the presence of benzoic acid, salicylic acid, p-amino salicylic acid, p-methoxy phenol and pmethyl phenol. The structures of the ...A new series of azo were derived from 2,5-di(p-amino phenyl)-3,6-diphenyl pyrazine in the presence of benzoic acid, salicylic acid, p-amino salicylic acid, p-methoxy phenol and pmethyl phenol. The structures of the synthesized compounds were determined on the basis of their FTIR, UV (ultraviolet), elemental analysis and H-NMR (H-nuclear magnetic resonance) spectral date. The purity of synthesized compounds was checked by performing TLC (thin layer chromatography). The antibacterial activity was evaluated in DMSO (dimethyl sulfoxide).展开更多
This study was conducted to investigate the effects of fresh fermented soybean meal(FSM) on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia(NH3) and partic...This study was conducted to investigate the effects of fresh fermented soybean meal(FSM) on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia(NH3) and particulate matter(PM) in the piggery. A total of 472 nursery piglets(Landrace×Yorkshire,(16.3±0.36) kg body weight) were randomly allocated into two treatments with 236 pigs in each treatment. The pigs were fed the basal diet without fresh FSM(control) or diet containing 10%(100 g/kg) fresh FSM(FSM group), and the crude protein content of the two groups was consistent. The feeding trial lasted for 28 d. The results showed that the pigs fed fresh FSM had increased(P〈0.05) average daily gain(ADG) compared with the control. There was no significant difference(P〈0.05) in feed to gain ratio(F:G) between the two groups. During the whole experiment, the concentration of NH3 in the piggery decreased(P〈0.05) by 19.0%, and the concentrations of PM(PM(10) and PM(2.5)) in the piggery decreased(P〈0.05) by 19.9% and 11.6%, respectively, in the FSM group, compared with the control. The ammonia nitrogen and nitrite content in feces increased(P〈0.05) by 32.9% and 28.4%, respectively, in the FSM group. The fecal p H declined(P〈0.05) significantly in the FSM group compared with the control. At the end of experiment, total protein(TP) concentration was increased(P〈0.05) significantly and blood urea nitrogen(BUN) concentration was decreased(P〈0.05) for pigs fed the diet with fresh FSM. The results indicated that dietary fresh FSM not only improved the growth performance of nursery piglets, but also reduced the NH3 concentration in the piggery due to nitrogen conversion, and decreased the concentrations of PM(10) and PM(2.5) in the piggery.展开更多
The excellent bactericidal performance of silver nanoparticles (Ag NPs) has led to their wide applications, resulting in increasing concerns about their potential environmental impacts. This study evaluated the infl...The excellent bactericidal performance of silver nanoparticles (Ag NPs) has led to their wide applications, resulting in increasing concerns about their potential environmental impacts. This study evaluated the influences of different concentrations of Ag NPs (0, 1, 10, and 100 μg g^-1 dry soil) on the ammonia-oxidizing microorganisms in soil at cultivation temperatures of 25 and 5 ℃ for 37 d. The results showed that 1μg g^-1 dry soil of Ag NPs had no acute effects on the ammonia-oxidizing microorganisms. However, 10 and 100μg g^-1 dry soil of Ag NPs levels were found to significantly inhibit the activities of soil nitrification, with a decrease of 69.89% and 94.55%, respectively, at 25 ℃ and 61.65% and 83.79%, respectively, at 5℃ compared to the control (0 μg g^-1 dry soil of Ag NPs). These levels of Ag NPs also obviously decreased soil urease activity from about 380.47 ± 0.07 (at 5℃) and 529.76 ± 13.44 (at 25℃) mg N g^-1 dry soil d^-1 to 61.70 ± 2.97 and 68.29 ± 8.22 mg N g^-1 dry soil d^-1, respectively, after 37 d of cultivation. Quantitative polymerase chain reaction showed the abundance of ammonia-oxidizing archaea and bacteria. For the same exposure time, the effects of Ag NPs on the activities of ammonia-oxidizing microorganisms and urease decreased with decreasing temperature. The threshold concentration of Ag NPs that induced negative effects on ammonia-oxidizing microorganisms was higher at 5 -C than at 25 -C. Therefore, the temperature has a major impact on the toxicity of Ag NPs to ammonia-oxidizing microorganisms and on the urease activity, with toxicity being reduced with decreasing temperature.展开更多
A visible-light induced decarboxylative aza-Darzens reaction between N-aryl glycines and diazo compounds was developed, which affords various mono-substituted aziridines in good yields.
基金the National Natural Science Foundation of China (No.39770427).
文摘Two soils, one consisting of 1:1 clay minerals at pH 4.5 and the other containing 2:1 clay minerals at pH 7.0, were used to estimate the conversion of added NH+4 under different C/N ratios (glucose as the C source) and the addition of potassium. Under lower C/N ratios (0:1 and 5:1), a large part of the added NH4+ in the acid soil was held in the forms of either exchangeable or water soluble NH4+ for a relatively long time and under higher C/N ratio (50:1), a large amount of the added NH4+ was directly immobilized by microorganisms. In the second soil containing appreciable 2:1 type clay minerals a large part of the added NH+4 at first quickly entered the interlayer of the minerals under both lower and higher C/N ratios. In second condition, however, owing to microbial assimilation stimulated by glucose the newly fixed NH4+c ould be completely released in further incubation because of a large concentration gradient between external NH4+ and fixed NH4+ in the mineral interlayer caused by heterotrophic microorganisms, which imply the fixed NH4+ to be available to plants. The results also showed that if a large amount of K+ with carbon source together was added to soil, the higher K+ concentration of soil solution could impede the release of fixed NH4+ , even if there was a lot of carbon source.
文摘Co and Mo bimetallic nitrides supported on Mg(Al)O, MgO and γ-Al2O3 were prepared in temperatureprogrammed reactions with NH3. The surface morphology, chemical composition and catalytic activity for NH3 decomposition on the supported Co and Mo bimetallic nitrides were studied by X-ray diffractometer (XRD), NH3 temperature-programmed desorption and mass spectrometer (NH3-TPD-MS), temperature-programmed desorption and mass spectrometer (TPD-MS), H2 temperature-programmed surface reaction (H2-TPSR) and activity test. The phases of Co3Mo3N and MoN could be formed on Mg(Al)O, MgO and Al2O3 during the nitridation, and they might be more uniformly dispersed on Mg(Al)O and MgO than on γ-Al2O3. Transition metallic nitrides are generally considered as potential catalysts for hydrogen-involving reactions due to the entrance of hydrogen atoms into subsurface and the lattice of metallic nitrides. The diffusion of nitrogen in the bulk and the structure transformation of Co and Mo nitride compounds occur during NH3-TPD, but the supported Co and Mo bimetallic nitrides are not easily reduced at H2 atmosphere. Co3Mo3N/Mg(Al)O catalyst exhibits the highest activity, while Co3Mo3N/Al2O3 exhibits the lowest activity for NH3 decomposition. Furthermore, the catalytic activity of Co and Mo bimetallic nitrides is not only much higher than that of supported single metallic nitride, but also highly dependent upon the surface acidity and BET surface area of support.
基金the Grants for the Excellent Youth Scientists of Shandong Provincial Science Commission.No.2000BB2DBA1
文摘AIM: To study the effects of endogeous nitric oxide induced by 5-fluorouracil (5-FU) and L-arginine (L-Arg) on the human liver carcinoma model in nude mice. METHODS: The human liver carcinoma model in nude mice was established with BEL-7402 cells and normal saline (NS), 5-FU and 5-FU + L-Arg injected intraperitoneally. The tumor size was measured. The necrotic degree and range were observed under microscope. The apoptosis of cancer cell was detected by turmina deoxynucleotidyl transferanse mediated dUTP nick end labeling (TUNEL) method. Immunohistochemical method was performed to determine the expression of iNOS, P16, BAX. The chemical colorimetry was used to test the activity and nitrate reductase method was adopted to test the concentration of nitric oxide (NO) in the tumor tissue. The BI2000 pathological image analyzer was used to analyze the result of immunohistochemistry. RESULTS: 5-FU combined with L-Arg could inhibit the tumor growth apparently. In NS, 5-FU and 5-FU+L- Arg groups, the changes of tumor volumes were 257.978 ± 59.0, 172.232 ± 66.0 and 91.523 ± 26.7 mm3, respectively (P 〈 0.05 5-FU vs 5-FU ± L-Arg group;P 〈 0.05 NS ys 5-FU ± L-Arg group; P 〈 0.05, NS ys 5-FU group). The necrotic range and apoptosis index were significantly increased after the drug injection. The necrotic range was biggest in 5-FU + L-Arg group (X^2= 15.963, P 〈 0.05). The apoptosis indexes were as follows: NS, 17.4% ± 6.19%; 5-FU, 31.3% ± 12.3%; and 5-FU ± L-Arg, 46% ± 15.24% (P 〈 0.05, 5-FU ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU ± L-Arg; P 〈 0.05, NS ys 5-FU). The expression and activity of iNOS were increased in the tumor tissue. The concentration of NO was also increased. F of opticaldensity of iNOS, iNOS activity and NO concentration are 31.693, 21.949, and 33.909, respectively, P 〈 0.05. The concentration of NO was related to the expression of PI6 and BAX. The correlation coefficient was 0.764 and 0.554. CONCLUSION: 5-FU combined with L-Arg can inhibit the growth of tumor in nude mice. The effect may be related to inducing the synthesis and increasing the activity of iNOS. The production of NO is increased, and it can enhance the expression of apoptosis-related gene and antioncogene.
文摘The complex [Cu2(apo)4Cl4]·2H2O (apo=2-aminopyridine N-oxide) was obtained. A single- crystal X-ray study shows that the complex is a binuclear compound (Cu2C20H28Cl4N8O6). The coordination geometry about each copper atom is best described as a distorted square pyramid. The compound [Cu2(apo)4Cl4]·2H2O belongs to the triclinic system with space group P, lattice constants: a = 7.8550(7), b = 8.5378(7), c = 12.082(1) ?, α = 72.807(1), β = 77.641(1), γ = 70.800(1)(, V =724.85(11) ?3, Z=1, Mr =745.38, Dc=1.708 g/cm3, μ =1.886mm-1, F(000) =378, R=0.0359, wR2=0.0884 for 2220 reflections with I >2σ(I). The distances between Cu(II) and O atoms are in the range from 1.934(2) to 2.042(2)?. The distance between two copper atoms Cu-Cu(A) is 3.2978(8) ?. The distances of Cu-Cl(1) and Cu-Cl(2) are 2.2322(9), 2.5095(10) ?, respectively. There is no evident hydrogen bond between N and Cl.
文摘On the base of benzo [b] furo benzotriazoles several derivatives with expected biological activity were synthesized by alkylation and Mannich reactions. In the alkylation of ethyl iodide benzo [b] furo benzotriazoles received 1-ethyl-benzo [b] furo [3,2-g] benzotriazole and 3-ethyl-benzo [b] furo [2,3-f] benzotriazole. Aminometilirization Mannich reaction conditions with "the application as amino compound diethylamine, morpholine and piperazine of benzo [b] furo benzotriazoles were received (N, N-diethylaminomethyl), CN-morpholinometil) and (N-piperazinometil)-derivatives.
基金supported by the National Natural Science Foundation of China (No. 21507130)the Open Project Program of Beijing National Laboratory for Molecular Sciences (No. 20140142)+3 种基金the Open Project Program of Chongqing Key Laboratory of Environmental Materials and Remediation Technology from Chongqing University of Arts and Sciences (No. CEK1405)the Open Project Program of Jiangsu Key Laboratory of Vehicle Emissions Control (No. OVEC001)the Open Project Program of Chongqing Key Laboratory of Catalysis and Functional Organic Molecules from Chongqing Technology and Business University (1456029)the Chongqing Science & Technology Commission (Nos. cstc2016jcyj A0070, cstc2014pt-gc20002, cstckjcxljrc13)~~
文摘This work examines the influence of preparation methods on the physicochemical properties and catalytic performance of MnOx‐CeO2 catalysts for selective catalytic reduction of NO by NH3 (NH3‐SCR) at low temperature. Five different methods, namely, mechanical mixing, impregnation,hydrothermal treatment, co‐precipitation, and a sol‐gel technique, were used to synthesizeMnOx‐CeO2 catalysts. The catalysts were characterized in detail, and an NH3‐SCR model reaction waschosen to evaluate the catalytic performance. The results showed that the preparation methodsaffected the catalytic performance in the order: hydrothermal treatment > sol‐gel > co‐precipitation> impregnation > mechanical mixing. This order correlated with the surface Ce3+ and Mn4+ content,oxygen vacancies and surface adsorbed oxygen species concentration, and the amount of acidic sitesand acidic strength. This trend is related to redox interactions between MnOx and CeO2. The catalystformed by a hydrothermal treatment exhibited excellent physicochemical properties, optimal catalyticperformance, and good H2O resistance in NH3‐SCR reaction. This was attributed to incorporationof Mnn+ into the CeO2 lattice to form a uniform ceria‐based solid solution (containing Mn‐O‐Cestructures). Strengthening of the electronic interactions between MnOx and CeO2, driven by thehigh‐temperature and high‐pressure conditions during the hydrothermal treatment also improved the catalyst characteristics. Thus, the hydrothermal treatment method is an efficient and environment‐friendly route to synthesizing low‐temperature denitrification (deNOx) catalysts.
基金National Natural Science Foundation of China (No.29906008) and Natural Science Foundation of Shandong Province (No.Q99B15)
文摘By the reaction of poly(bromoacetyl styrene) (EBPS) with thiaurea (TU), a kind of novel chelating resin with heterocyaclic ring of sulfur and nitrogen, poly[4-(2-amino)thiazoleyl-4- vinylbenzene], was synthesized. Its structure was characterized by FTIR and elemental analysis. The factors which have influence on the reaction such as reaction time, solvents, and molar ratio of reactants were investigated.
文摘A new series of azo were derived from 2,5-di(p-amino phenyl)-3,6-diphenyl pyrazine in the presence of benzoic acid, salicylic acid, p-amino salicylic acid, p-methoxy phenol and pmethyl phenol. The structures of the synthesized compounds were determined on the basis of their FTIR, UV (ultraviolet), elemental analysis and H-NMR (H-nuclear magnetic resonance) spectral date. The purity of synthesized compounds was checked by performing TLC (thin layer chromatography). The antibacterial activity was evaluated in DMSO (dimethyl sulfoxide).
基金Project supported by the Key Agricultural Projects of Ningbo Science and Technology Bureau of Zhejiang Province(No.2013C11008),China
文摘This study was conducted to investigate the effects of fresh fermented soybean meal(FSM) on the growth performance of nursery piglets, nitrogen excretion in feces, and the concentrations of ammonia(NH3) and particulate matter(PM) in the piggery. A total of 472 nursery piglets(Landrace×Yorkshire,(16.3±0.36) kg body weight) were randomly allocated into two treatments with 236 pigs in each treatment. The pigs were fed the basal diet without fresh FSM(control) or diet containing 10%(100 g/kg) fresh FSM(FSM group), and the crude protein content of the two groups was consistent. The feeding trial lasted for 28 d. The results showed that the pigs fed fresh FSM had increased(P〈0.05) average daily gain(ADG) compared with the control. There was no significant difference(P〈0.05) in feed to gain ratio(F:G) between the two groups. During the whole experiment, the concentration of NH3 in the piggery decreased(P〈0.05) by 19.0%, and the concentrations of PM(PM(10) and PM(2.5)) in the piggery decreased(P〈0.05) by 19.9% and 11.6%, respectively, in the FSM group, compared with the control. The ammonia nitrogen and nitrite content in feces increased(P〈0.05) by 32.9% and 28.4%, respectively, in the FSM group. The fecal p H declined(P〈0.05) significantly in the FSM group compared with the control. At the end of experiment, total protein(TP) concentration was increased(P〈0.05) significantly and blood urea nitrogen(BUN) concentration was decreased(P〈0.05) for pigs fed the diet with fresh FSM. The results indicated that dietary fresh FSM not only improved the growth performance of nursery piglets, but also reduced the NH3 concentration in the piggery due to nitrogen conversion, and decreased the concentrations of PM(10) and PM(2.5) in the piggery.
基金supported by the National Natural Science Foundation of China (No. 51479034)the Fundamental Research Funds for the Central Universities of China (No. 2242016R30008)
文摘The excellent bactericidal performance of silver nanoparticles (Ag NPs) has led to their wide applications, resulting in increasing concerns about their potential environmental impacts. This study evaluated the influences of different concentrations of Ag NPs (0, 1, 10, and 100 μg g^-1 dry soil) on the ammonia-oxidizing microorganisms in soil at cultivation temperatures of 25 and 5 ℃ for 37 d. The results showed that 1μg g^-1 dry soil of Ag NPs had no acute effects on the ammonia-oxidizing microorganisms. However, 10 and 100μg g^-1 dry soil of Ag NPs levels were found to significantly inhibit the activities of soil nitrification, with a decrease of 69.89% and 94.55%, respectively, at 25 ℃ and 61.65% and 83.79%, respectively, at 5℃ compared to the control (0 μg g^-1 dry soil of Ag NPs). These levels of Ag NPs also obviously decreased soil urease activity from about 380.47 ± 0.07 (at 5℃) and 529.76 ± 13.44 (at 25℃) mg N g^-1 dry soil d^-1 to 61.70 ± 2.97 and 68.29 ± 8.22 mg N g^-1 dry soil d^-1, respectively, after 37 d of cultivation. Quantitative polymerase chain reaction showed the abundance of ammonia-oxidizing archaea and bacteria. For the same exposure time, the effects of Ag NPs on the activities of ammonia-oxidizing microorganisms and urease decreased with decreasing temperature. The threshold concentration of Ag NPs that induced negative effects on ammonia-oxidizing microorganisms was higher at 5 -C than at 25 -C. Therefore, the temperature has a major impact on the toxicity of Ag NPs to ammonia-oxidizing microorganisms and on the urease activity, with toxicity being reduced with decreasing temperature.
基金supported by the National Natural Science Foundation of China(2147224921202207)+1 种基金the Pearl River S&T Nova Program of Guangzhou(2013J2200017)the Fundamental Research Funds for the Central Universities(14lgzd05)
文摘A visible-light induced decarboxylative aza-Darzens reaction between N-aryl glycines and diazo compounds was developed, which affords various mono-substituted aziridines in good yields.