Due to their very small size,nanoparticles can interact with all cells in the central nervous system.One of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that...Due to their very small size,nanoparticles can interact with all cells in the central nervous system.One of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that are citrate coated for electrostatic stabilization.To determine their influence on murine blood-derived monocytes,which easily enter the injured central nervous system,we applied VSOP and carboxydextran-coated superparamagnetic iron oxide nanoparticles(Resovist).We assessed their impact on the viability,cytokine,and chemokine secretion,as well as iron uptake of murine blood-derived monocytes.We found that(1)the monocytes accumulated VSOP and Resovist,(2)this uptake seemed to be nanoparticle-and time-dependent,(3)the decrease of monocytes viability was treatment-related,(4)VSOP and Resovist incubation did not alter cytokine homeostasis,and(5)overall a 6-hour treatment with 0.75 mM VSOP-R1 was probably sufficient to effectively label monocytes for future experiments.Since homeostasis is not altered,it is safe to label blood-derived monocles with VSOP.VSOP labeled monocytes can be used to study injured central nervous system sites further,for example with drug-carrying VSOP.展开更多
The IEEE 802.15.4 standard is widely used in wireless sensor networks （WSNs）. In this paper, we propose a priority-based IEEE 802.15.4 carrier sense multiple access with collision avoidance （CSMA/CA） mechanism for...The IEEE 802.15.4 standard is widely used in wireless sensor networks （WSNs）. In this paper, we propose a priority-based IEEE 802.15.4 carrier sense multiple access with collision avoidance （CSMA/CA） mechanism for WSNs. Considering traffic load and traffic type of sensor nodes, we classify sensor nodes into three types. In our mechanism, different contention parameters are set for nodes with different priority levels, in order that nodes with high priority achieve high probability to access the channel. By modeling the proposed mechanism using a Markov chain, we analyze and compute the successful transmission probability, throughput and energy consumption for nodes with different priority levels. Finally, our numerical results demonstrate that our mechanism performs well for WSNs.展开更多
Tramadol is an atypical opioid analgesic widely used in small animal practice.This study was designed to determine the effect of a single intravenous (IV) dose of tramadol on the minimum alveolar concentration (MAC) o...Tramadol is an atypical opioid analgesic widely used in small animal practice.This study was designed to determine the effect of a single intravenous (IV) dose of tramadol on the minimum alveolar concentration (MAC) of sevoflurane in dogs.Six beagle dogs were anesthetized twice to determine the sevoflurane MAC with or without an administration of tramadol (4 mg/kg,IV) at 7-days interval.The sevoflurane MAC was determined using a tail clamp method in each dog ventilated with positive pressure ventilation.The tramadol administration produced a significant reduction in the sevoflurane MAC by 22.3 ± 12.2% (1.44 ± 0.28% with tramadol versus 1.86 ± 0.29% without tramadol,P =0.010).This MAC reduction had been determined from 122 ± 19 to 180 ± 41 min following the tramadol administration.During this period,the plasma concentrations of tramadol and its metabolite,O-desmethyltramadol (M1),decreased from 429 ± 64 to 332 ± 55 ng/mL and from 136 ± 24 to 114 ± 68 ng/mL,respectively,but these changes were not statistically significant (P = 0.070 for tramadol and P = 0.716 for M1).There was no significant difference in heart rate,mean arterial blood pressure and SpO2between the control and tramadol treatment.The dogs that received tramadol treatment sometimes breathed spontaneously.Therefore,their respiratory rates significantly increased and PETCO2decreased during the MAC determination.In conclusion,the single IV dose of tramadol produced a significant reduction in the sevoflurane MAC in dog.展开更多
基金supported by Deutsche Forschungsgemeinschaft(DFG)grant Klinische Forschergruppe(KFO)213(to JG).
文摘Due to their very small size,nanoparticles can interact with all cells in the central nervous system.One of the most promising nanoparticle subgroups are very small superparamagnetic iron oxide nanoparticles(VSOP)that are citrate coated for electrostatic stabilization.To determine their influence on murine blood-derived monocytes,which easily enter the injured central nervous system,we applied VSOP and carboxydextran-coated superparamagnetic iron oxide nanoparticles(Resovist).We assessed their impact on the viability,cytokine,and chemokine secretion,as well as iron uptake of murine blood-derived monocytes.We found that(1)the monocytes accumulated VSOP and Resovist,(2)this uptake seemed to be nanoparticle-and time-dependent,(3)the decrease of monocytes viability was treatment-related,(4)VSOP and Resovist incubation did not alter cytokine homeostasis,and(5)overall a 6-hour treatment with 0.75 mM VSOP-R1 was probably sufficient to effectively label monocytes for future experiments.Since homeostasis is not altered,it is safe to label blood-derived monocles with VSOP.VSOP labeled monocytes can be used to study injured central nervous system sites further,for example with drug-carrying VSOP.
基金supported by the National Natural Science Foundation of China (60673185, 61073197)the Natural Science Foundation of Jiangsu Province (BK2010548)+2 种基金Scientific & Technological Support Project (Industry) of Jiangsu Province(BE2011186)the State Key Laboratory Program for Novel Software technology (Nanjing University, KFKT2010B08)the Research Innovation Program for College Graduates in Jiangsu Province(CXLX11 0262)
文摘The IEEE 802.15.4 standard is widely used in wireless sensor networks （WSNs）. In this paper, we propose a priority-based IEEE 802.15.4 carrier sense multiple access with collision avoidance （CSMA/CA） mechanism for WSNs. Considering traffic load and traffic type of sensor nodes, we classify sensor nodes into three types. In our mechanism, different contention parameters are set for nodes with different priority levels, in order that nodes with high priority achieve high probability to access the channel. By modeling the proposed mechanism using a Markov chain, we analyze and compute the successful transmission probability, throughput and energy consumption for nodes with different priority levels. Finally, our numerical results demonstrate that our mechanism performs well for WSNs.
文摘Tramadol is an atypical opioid analgesic widely used in small animal practice.This study was designed to determine the effect of a single intravenous (IV) dose of tramadol on the minimum alveolar concentration (MAC) of sevoflurane in dogs.Six beagle dogs were anesthetized twice to determine the sevoflurane MAC with or without an administration of tramadol (4 mg/kg,IV) at 7-days interval.The sevoflurane MAC was determined using a tail clamp method in each dog ventilated with positive pressure ventilation.The tramadol administration produced a significant reduction in the sevoflurane MAC by 22.3 ± 12.2% (1.44 ± 0.28% with tramadol versus 1.86 ± 0.29% without tramadol,P =0.010).This MAC reduction had been determined from 122 ± 19 to 180 ± 41 min following the tramadol administration.During this period,the plasma concentrations of tramadol and its metabolite,O-desmethyltramadol (M1),decreased from 429 ± 64 to 332 ± 55 ng/mL and from 136 ± 24 to 114 ± 68 ng/mL,respectively,but these changes were not statistically significant (P = 0.070 for tramadol and P = 0.716 for M1).There was no significant difference in heart rate,mean arterial blood pressure and SpO2between the control and tramadol treatment.The dogs that received tramadol treatment sometimes breathed spontaneously.Therefore,their respiratory rates significantly increased and PETCO2decreased during the MAC determination.In conclusion,the single IV dose of tramadol produced a significant reduction in the sevoflurane MAC in dog.
