A novel floating osmotic pump controlled release system （FOP） and traditional matrix sustained release tablets （MT） of dipyridamole （DIP） were characterized in terms of pharmacokinetics, drug release, and in vit...A novel floating osmotic pump controlled release system （FOP） and traditional matrix sustained release tablets （MT） of dipyridamole （DIP） were characterized in terms of pharmacokinetics, drug release, and in vitro-in vivo correlation. In vivo study was performed by a three-crossover study in six beagle dogs relative to the conventional tablet （CT）. A HPLC method for the determination of DIP in the plasma was developed. Cumulative percent of absorption fraction was compared to that of in vitro cumulative release. Both FOP and MT displayed obvious extended release characteristic in vivo while FOP showed a better extended release behavior. The bioavailability of FOP was higher than that of MT and a zero-order release linear correlation of DIP between fraction absorbed in vivo and fraction dissolved in vitro was established for FOP while not for MT. The results indicated the existence of an absorption window in upper part of the GI track of DIP, which meant that floating system could be excellent for the drug delivery. In addition, the in vitro model was a good choice for depicting in vivo absorption and for optimization of the formulation of FOP if it is needed to be bio-equivalent to MT.展开更多
Extremely large accumulation of green algae Enteromorpha prolifera floated along China'coastal region of the Yellow Sea ever since the summer of 2008.Amplified Fragment Length Polymorphism (AFLP) analysis was appl...Extremely large accumulation of green algae Enteromorpha prolifera floated along China'coastal region of the Yellow Sea ever since the summer of 2008.Amplified Fragment Length Polymorphism (AFLP) analysis was applied to assess the genetic diversity and relationships among E. prolifera samples collected from 9 affected areas of the Yellow Sea.Two hundred reproducible fragments were generated with 8 AFLP primer combinations,of which 194 (97%) were polymorphic. The average Nei's genetic diversity, the coefficiency of genetic differentiation (Gst), and the average gene flow estimated from Gst in the 9 populations were 0.4018, 0.6404 and 0.2807 respectively. Cluster analysis based on the unweighed pair group method with arithmetic averages (UPGMA) showed that the genetic relationships within one population or among different populations were all related to their collecting locations and sampling time. Large genetic differentiation was detected among the populations.The E. prolifera originated from different areas and were undergoing a course of mixing.展开更多
A qualitative and quantitative test method of fingerprint of Wuji gastric floating sustained-release tablets was established. High performance liquid chromatography （HPLC） was adopted, using Agilent ZORBAX SB-C18 co...A qualitative and quantitative test method of fingerprint of Wuji gastric floating sustained-release tablets was established. High performance liquid chromatography （HPLC） was adopted, using Agilent ZORBAX SB-C18 column （250 mm×4.6 mm, 5 μm） as the chromatographic column, and acetonitrile-0.05 mol/L potassium dihydrogen phosphate solution as the mobile phase in a gradient elution with the flow rate of 1.0 mL/min. Sample solution （10 μL） was injected and was tested at the wavelength of 225 nm for 75 min at the column temperature of 30 ℃, Fingerprint similarity software （2004A version） was used to conduct data analysis. A total of 11 batches of Wuji gastric floating sustained-release tablets were tested and analyzed with HPLC fingerprint. Seventeen common peaks were found and the similarity of the 11 batches of agents was greater than 0.9, indicating that the production process of the agent is stable and feasible. The method is operable and could effectively control the quality of Wuji gastric floating sustained-release tablets.展开更多
The thermal conduction of suspended few-layer hexagonal boron nitride （h-BN） sheets was experimentally investigated using a noncontact micro-Raman spectroscopy method. The first-order temperature coefficients for mo...The thermal conduction of suspended few-layer hexagonal boron nitride （h-BN） sheets was experimentally investigated using a noncontact micro-Raman spectroscopy method. The first-order temperature coefficients for monolayer （1L）, bilayer （2L） and nine-layer （9L） h-BN sheets were measured to be -（3.41 ± 0.12）× 10-2, -（3.15 ± 0.14） × 10-2 and -（3.78 ±0.16）× 10-2 cm-1.K-1, respectively. The room-temperature thermal conductivity of few-layer h-BN sheets was found to be in the range from 227 to 280 W.m-1-K-1, which is comparable to that of bulk h-BN, indicating their potential use as important components to solve heat dissipation problems in thermal management configurations.展开更多
Aims Many wetlands are polluted with both nutrients and toxic metals and vegetated largely by clonal plants.We hypothesized that eutrophication and clonal integration can increase phytoremediation of toxic metal pollu...Aims Many wetlands are polluted with both nutrients and toxic metals and vegetated largely by clonal plants.We hypothesized that eutrophication and clonal integration can increase phytoremediation of toxic metal pollution by increasing plant growth,even under the stress imposed by toxicity.Methods To test this hypothesis,single ramets of the common,widespread,floating,stoloniferous plant Pistia stratiotes L.,were grown for 42 days at two levels of nutrient availability with and without 0.6 mg L^(-1) cadmium.Ramets were either severed from their vegetative offspring to prevent clonal integration or left connected,and severed offspring were either removed to eliminate intraclonal competition or left in place.Important Findings Plants subjected to cadmium addition accumulated almost twice as much dry mass if given the higher nutrient level,due mainly to a doubling of the number of clonal offspring.Severance had little effect on the final mass of the parent plus offspring ramets.Removing offspring following severance had no effect on the final mass of the parental ramet in the presence of added cadmium,but it did increase the final mass of the parent in the absence of cadmium.These results support the hypothesis that eutrophication can increase remediation of toxic metal pollution by aquatic macrophytes but provided no evidence that clonal integration can affect remediation.Species such as P.stratiotes may help remediate co-pollution of wetlands with toxic metals and nutrients,and fragmentation of clones may not affect their remediation capacity.展开更多
To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating el...To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating electrical potential distribution on the micro-electrode chip is performed by COMSOL software, and the simulation result shows that the coupled electrical poten- tial on the floating drain electrodes is very close to the original electrical potential applied on the gate electrode, whicb means that the method can provide di-electrophoresis （DEP） force for all the electrode pairs at one time, thus realizing large-scale as- sembly at one time. With Cu/CuO nanowires well dispersed and micro-electrode chip fabrication, nanowires assembly experiments are performed and the experimental results show that Cu/CuO nanowires are assembled at hundreds of micro-electrodes pairs at one time, and the success rate of nanowires assembly also reaches 90%.展开更多
文摘A novel floating osmotic pump controlled release system （FOP） and traditional matrix sustained release tablets （MT） of dipyridamole （DIP） were characterized in terms of pharmacokinetics, drug release, and in vitro-in vivo correlation. In vivo study was performed by a three-crossover study in six beagle dogs relative to the conventional tablet （CT）. A HPLC method for the determination of DIP in the plasma was developed. Cumulative percent of absorption fraction was compared to that of in vitro cumulative release. Both FOP and MT displayed obvious extended release characteristic in vivo while FOP showed a better extended release behavior. The bioavailability of FOP was higher than that of MT and a zero-order release linear correlation of DIP between fraction absorbed in vivo and fraction dissolved in vitro was established for FOP while not for MT. The results indicated the existence of an absorption window in upper part of the GI track of DIP, which meant that floating system could be excellent for the drug delivery. In addition, the in vitro model was a good choice for depicting in vivo absorption and for optimization of the formulation of FOP if it is needed to be bio-equivalent to MT.
基金supported by the National Science and Technology Pillar Program(2008BAC-49B01)Qingdao Municipal Science and Technology Plan Project(08-1-7-1-hy),Qingdao Municipal Science and Technology Pillar Plan Project(09-2-5-5-hy)
文摘Extremely large accumulation of green algae Enteromorpha prolifera floated along China'coastal region of the Yellow Sea ever since the summer of 2008.Amplified Fragment Length Polymorphism (AFLP) analysis was applied to assess the genetic diversity and relationships among E. prolifera samples collected from 9 affected areas of the Yellow Sea.Two hundred reproducible fragments were generated with 8 AFLP primer combinations,of which 194 (97%) were polymorphic. The average Nei's genetic diversity, the coefficiency of genetic differentiation (Gst), and the average gene flow estimated from Gst in the 9 populations were 0.4018, 0.6404 and 0.2807 respectively. Cluster analysis based on the unweighed pair group method with arithmetic averages (UPGMA) showed that the genetic relationships within one population or among different populations were all related to their collecting locations and sampling time. Large genetic differentiation was detected among the populations.The E. prolifera originated from different areas and were undergoing a course of mixing.
基金The National Natural Science Foundation of China(Grant No.81460609)
文摘A qualitative and quantitative test method of fingerprint of Wuji gastric floating sustained-release tablets was established. High performance liquid chromatography （HPLC） was adopted, using Agilent ZORBAX SB-C18 column （250 mm×4.6 mm, 5 μm） as the chromatographic column, and acetonitrile-0.05 mol/L potassium dihydrogen phosphate solution as the mobile phase in a gradient elution with the flow rate of 1.0 mL/min. Sample solution （10 μL） was injected and was tested at the wavelength of 225 nm for 75 min at the column temperature of 30 ℃, Fingerprint similarity software （2004A version） was used to conduct data analysis. A total of 11 batches of Wuji gastric floating sustained-release tablets were tested and analyzed with HPLC fingerprint. Seventeen common peaks were found and the similarity of the 11 batches of agents was greater than 0.9, indicating that the production process of the agent is stable and feasible. The method is operable and could effectively control the quality of Wuji gastric floating sustained-release tablets.
文摘The thermal conduction of suspended few-layer hexagonal boron nitride （h-BN） sheets was experimentally investigated using a noncontact micro-Raman spectroscopy method. The first-order temperature coefficients for monolayer （1L）, bilayer （2L） and nine-layer （9L） h-BN sheets were measured to be -（3.41 ± 0.12）× 10-2, -（3.15 ± 0.14） × 10-2 and -（3.78 ±0.16）× 10-2 cm-1.K-1, respectively. The room-temperature thermal conductivity of few-layer h-BN sheets was found to be in the range from 227 to 280 W.m-1-K-1, which is comparable to that of bulk h-BN, indicating their potential use as important components to solve heat dissipation problems in thermal management configurations.
基金supported by the National Natural Science Foundation of China(31761123001,31870610)the Joint Fund of the Zhejiang Provincial Natural Science Foundation(LTZ20C030001)the Ten Thousand Talent Program of Zhejiang Province(2018R52016).
文摘Aims Many wetlands are polluted with both nutrients and toxic metals and vegetated largely by clonal plants.We hypothesized that eutrophication and clonal integration can increase phytoremediation of toxic metal pollution by increasing plant growth,even under the stress imposed by toxicity.Methods To test this hypothesis,single ramets of the common,widespread,floating,stoloniferous plant Pistia stratiotes L.,were grown for 42 days at two levels of nutrient availability with and without 0.6 mg L^(-1) cadmium.Ramets were either severed from their vegetative offspring to prevent clonal integration or left connected,and severed offspring were either removed to eliminate intraclonal competition or left in place.Important Findings Plants subjected to cadmium addition accumulated almost twice as much dry mass if given the higher nutrient level,due mainly to a doubling of the number of clonal offspring.Severance had little effect on the final mass of the parent plus offspring ramets.Removing offspring following severance had no effect on the final mass of the parental ramet in the presence of added cadmium,but it did increase the final mass of the parent in the absence of cadmium.These results support the hypothesis that eutrophication can increase remediation of toxic metal pollution by aquatic macrophytes but provided no evidence that clonal integration can affect remediation.Species such as P.stratiotes may help remediate co-pollution of wetlands with toxic metals and nutrients,and fragmentation of clones may not affect their remediation capacity.
基金supported by the National Natural Science Foundation of China(Grant No.51005230)China Postdoctoral Science Foundation(Grant No.2012M520654)the Education Department of Liaoning Province Science and Ttechnology Research Projects(Grant No.L2012213)
文摘To improve the efficiency of nano-electronic device fabrication, a new method named floating electrical potential assembly is proposed to realize large-scale assembly of Cu/CuO nanowires, The simulation of floating electrical potential distribution on the micro-electrode chip is performed by COMSOL software, and the simulation result shows that the coupled electrical poten- tial on the floating drain electrodes is very close to the original electrical potential applied on the gate electrode, whicb means that the method can provide di-electrophoresis （DEP） force for all the electrode pairs at one time, thus realizing large-scale as- sembly at one time. With Cu/CuO nanowires well dispersed and micro-electrode chip fabrication, nanowires assembly experiments are performed and the experimental results show that Cu/CuO nanowires are assembled at hundreds of micro-electrodes pairs at one time, and the success rate of nanowires assembly also reaches 90%.
