A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analys...A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analysis and histopathological evaluation were carried out.The results showed that Ca–P coating could obviously improve the corrosion resistance of the pure Mg membrane.The in vivo results showed that Mg membrane coated with Ca–P would take 8 weeks to be completely absorbed.However, Mg membrane was completely absorbed within 1 week.Histopathological evaluation showed that the Ca–P-coated Mg membranes were significantly better than Ti membranes at the early implantation time(4 weeks), and with the time prolonging,the performance of the coated Mg membrane was not as good as pure Ti membranes(but still better than blank group) at 8 and 12 weeks.The coated biodegradable Mg membrane had a good promising application in GBR.But further studies have to be done to further decrease the degradation rate of pure Mg membrane.展开更多
In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and tra...In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and transverse direction(TD).The FCGR tests were conducted at a constant load ratio(R=0.1)and maximum stress intensity factor(KMax=15.6 MPa√m)to investigate the crack closure effect.For both constant R and KMax conditions:(i)the load-displacement curves for every loading cycle were linear for a_(n)∥ to RD and TD,indicating no crack closure;(ii)the FCGR was found to be lower for an∥RD than an∥TD over the entire stress intensity factor range(△K).The hot-rolled sample contained long-aligned Al11Ce3 intermetallic phase within grain boundaries that are elongated along RD.During the FCGR test,{10.12}<10.11>extension twins(ET)with lamellae∼⊥and c-axis∼∥to these elongated intermetallics along RD developed irrespective of the notch orientation.During the loading cycle,these intermetallics along RD generate back-stresses,reducing the in-plane tensile stress∼||and∼⊥to crack-tip to∼0 for a_(n)∥to RD and TD,respectively.Hence,lenticular ET∼||⊥and∼||,with c-axis∼||and∼⊥to crack path activates,leading to trans and inter lamellar crack for anto RD and TD,respectively,and anisotropic FCGR.Translamellar crack in a_(n)∥RD reduces the FCGR due to plastic energy dissipation as perceived by comparatively more geometrically necessary boundaries(GNBs).On the other hand,faster FCGR was obtained for a_(n)∥TD due to interlamellar cracking.Thus,the crack growth through the matrix-ET interfaces was favoured due to strain incompatibility.The Fractography for a_(n)∥RD shows smaller elongated grooves along crack propagation,which indicates crack arrest.However,larger elongated grooves for a_(n)||TD indicated easy crack propagation due to favourable interlamellar crack.展开更多
Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (...Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (with & without), phosphorus supplementation at the levels of 0, 20, 40 and 80 kg P·ha-1. Both treatments were replicated four times in a split plot design. The macronutrients considered were N, P, K, Ca and Mg. Results showed that inoculation with B. japonicum significantly contribute to the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole soybean plant. Likewise, phosphorus supplementation significantly enhanced the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole plant. The use of effective strains of rhizobia and P supplementation was an effective way of enhancing the growth of soybean, eventually the uptake of macronutrients in plant organs.展开更多
A pot experiment was conducted to study the effects of magnesium on carbon and nitrogen metabolism of soybean at different nitrogen supplying levels. The results showed that the effects of magnesium at low nitrogen ra...A pot experiment was conducted to study the effects of magnesium on carbon and nitrogen metabolism of soybean at different nitrogen supplying levels. The results showed that the effects of magnesium at low nitrogen rate on N content, soluble protein, soluble sugar contents were not alike at different growth stage, although nodule dry weights raised, the yield and protein content of seeds decreased, however, the oil content was improved. The application of magnesium at medium and high nitrogen supplying levels promoted the uptake of N effectively, increased the soluble protein and soluble sugar contents, but the nodule dry weights of application magnesium at medium nitrogen supplying level decreased and the yield increased only a little despite the improved quality. Application of magnesium at high nitrogen supplying level raised nodule dry weights and soybean yield significantly, the quality of seeds was also improved.展开更多
[Objectives]This study was conducted to investigate the effects of magnesium on the yield of Blumea balsamifera(L.)DC.and the accumulation of primary metabolites that affect yield of the medicinal material.[Methods]Th...[Objectives]This study was conducted to investigate the effects of magnesium on the yield of Blumea balsamifera(L.)DC.and the accumulation of primary metabolites that affect yield of the medicinal material.[Methods]The annual seedlings of B.balsamifera were selected as experimental materials.The treatment concentrations of magnesium(Mg)were set as 0,1.5,15 and 150 mg/ml supplied by MgSO4·7H2O.The yield of the medicinal material was measured dynamically.And the content of total sugar was determined by 3,5-dinitrosalicylic acid colorimetry;the content of crude protein was determined by the Kjeldahl method;the ash content was determined by the high-temperature burning method;the crude fat content was determined with a crude fat instrument;and the crude fiber content was determined by the acid-base washing and weighing method.[Results]Mg significantly increased the yield of B.balsamifera medicinal material,especially 15 mg/ml Mg.It was found that in September,October and November,1.5 mg/ml and 15 mg/ml Mg significantly increased the contents of primary metabolites including total sugar,ash,crude protein,crude fat and crude fiber,and 150 mg/ml of Mg increased the accumulation of total sugar,ash,crude protein and crude fiber to different degrees,but had certain inhibitory effect on the accumulation of crude fat.In December,the application of Mg inhibited the accumulation of total sugar,ash and crude protein to different degrees,but significantly promoted the accumulation of crude fat and fiber.[Conclusions]This study provides a theoretical basis for clarifying the effects of different concentrations of magnesium on plant growth.展开更多
基金financially supported by the Key Program of China on Biomedical Materials Research and Tissue and Organ Replacement (Nos.2016YFC1101804 and 2016YFC1100604)Shenyang Key R&D and Technology Transfer Program (No.Z18-0-027)
文摘A novel calcium-phosphate(Ca–P)-coated magnesium(Mg) membrane used for guided bone regeneration(GBR) was studied.The microstructural characterization, electrochemical test, immersion test,fluorescence labeling analysis and histopathological evaluation were carried out.The results showed that Ca–P coating could obviously improve the corrosion resistance of the pure Mg membrane.The in vivo results showed that Mg membrane coated with Ca–P would take 8 weeks to be completely absorbed.However, Mg membrane was completely absorbed within 1 week.Histopathological evaluation showed that the Ca–P-coated Mg membranes were significantly better than Ti membranes at the early implantation time(4 weeks), and with the time prolonging,the performance of the coated Mg membrane was not as good as pure Ti membranes(but still better than blank group) at 8 and 12 weeks.The coated biodegradable Mg membrane had a good promising application in GBR.But further studies have to be done to further decrease the degradation rate of pure Mg membrane.
基金support provided by the Science and Engineering Research Board(Ref.no.:ECR/2016/000125)Department of Science and Technology,Government of India.SB acknowledges the funding by Alexander von Humboldt Foundation,Germany.
文摘In this work,anisotropic fatigue crack growth rate(FCGR)behaviour in a hot-rolled Mg-3wt%Al-0.5wt%Ce alloy was investigated using compact tension(CT)specimens with notch(an)parallel to the rolling direction(RD)and transverse direction(TD).The FCGR tests were conducted at a constant load ratio(R=0.1)and maximum stress intensity factor(KMax=15.6 MPa√m)to investigate the crack closure effect.For both constant R and KMax conditions:(i)the load-displacement curves for every loading cycle were linear for a_(n)∥ to RD and TD,indicating no crack closure;(ii)the FCGR was found to be lower for an∥RD than an∥TD over the entire stress intensity factor range(△K).The hot-rolled sample contained long-aligned Al11Ce3 intermetallic phase within grain boundaries that are elongated along RD.During the FCGR test,{10.12}<10.11>extension twins(ET)with lamellae∼⊥and c-axis∼∥to these elongated intermetallics along RD developed irrespective of the notch orientation.During the loading cycle,these intermetallics along RD generate back-stresses,reducing the in-plane tensile stress∼||and∼⊥to crack-tip to∼0 for a_(n)∥to RD and TD,respectively.Hence,lenticular ET∼||⊥and∼||,with c-axis∼||and∼⊥to crack path activates,leading to trans and inter lamellar crack for anto RD and TD,respectively,and anisotropic FCGR.Translamellar crack in a_(n)∥RD reduces the FCGR due to plastic energy dissipation as perceived by comparatively more geometrically necessary boundaries(GNBs).On the other hand,faster FCGR was obtained for a_(n)∥TD due to interlamellar cracking.Thus,the crack growth through the matrix-ET interfaces was favoured due to strain incompatibility.The Fractography for a_(n)∥RD shows smaller elongated grooves along crack propagation,which indicates crack arrest.However,larger elongated grooves for a_(n)||TD indicated easy crack propagation due to favourable interlamellar crack.
文摘Field and glasshouse experiments were conducted to study the effect of B. japonicum inoculation and phosphorus supplementation on macronutrient uptake by soybean. The treatments consisted of B. japonicum inoculation (with & without), phosphorus supplementation at the levels of 0, 20, 40 and 80 kg P·ha-1. Both treatments were replicated four times in a split plot design. The macronutrients considered were N, P, K, Ca and Mg. Results showed that inoculation with B. japonicum significantly contribute to the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole soybean plant. Likewise, phosphorus supplementation significantly enhanced the uptake of N, P, K, Ca and Mg in roots, shoots, pods and the whole plant. The use of effective strains of rhizobia and P supplementation was an effective way of enhancing the growth of soybean, eventually the uptake of macronutrients in plant organs.
基金Sponsored by the Great Committee of Science and Technology of National Tenth "Five-year Plan" (2001BA50705-01)
文摘A pot experiment was conducted to study the effects of magnesium on carbon and nitrogen metabolism of soybean at different nitrogen supplying levels. The results showed that the effects of magnesium at low nitrogen rate on N content, soluble protein, soluble sugar contents were not alike at different growth stage, although nodule dry weights raised, the yield and protein content of seeds decreased, however, the oil content was improved. The application of magnesium at medium and high nitrogen supplying levels promoted the uptake of N effectively, increased the soluble protein and soluble sugar contents, but the nodule dry weights of application magnesium at medium nitrogen supplying level decreased and the yield increased only a little despite the improved quality. Application of magnesium at high nitrogen supplying level raised nodule dry weights and soybean yield significantly, the quality of seeds was also improved.
基金Supported by National Natural Science Foundation of China(81403035)Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(1630032019004)Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(1630032020002).
文摘[Objectives]This study was conducted to investigate the effects of magnesium on the yield of Blumea balsamifera(L.)DC.and the accumulation of primary metabolites that affect yield of the medicinal material.[Methods]The annual seedlings of B.balsamifera were selected as experimental materials.The treatment concentrations of magnesium(Mg)were set as 0,1.5,15 and 150 mg/ml supplied by MgSO4·7H2O.The yield of the medicinal material was measured dynamically.And the content of total sugar was determined by 3,5-dinitrosalicylic acid colorimetry;the content of crude protein was determined by the Kjeldahl method;the ash content was determined by the high-temperature burning method;the crude fat content was determined with a crude fat instrument;and the crude fiber content was determined by the acid-base washing and weighing method.[Results]Mg significantly increased the yield of B.balsamifera medicinal material,especially 15 mg/ml Mg.It was found that in September,October and November,1.5 mg/ml and 15 mg/ml Mg significantly increased the contents of primary metabolites including total sugar,ash,crude protein,crude fat and crude fiber,and 150 mg/ml of Mg increased the accumulation of total sugar,ash,crude protein and crude fiber to different degrees,but had certain inhibitory effect on the accumulation of crude fat.In December,the application of Mg inhibited the accumulation of total sugar,ash and crude protein to different degrees,but significantly promoted the accumulation of crude fat and fiber.[Conclusions]This study provides a theoretical basis for clarifying the effects of different concentrations of magnesium on plant growth.
