Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochast...Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochastic models is not well understood.The present study aimed to address this gap by conducting a comparative study using the susceptible,exposed,infectious,and recovered(SEIR)model and its extended CMs from the coronavirus disease 2019 modeling literature.We demonstrated the equivalence of the numerical solution of CMs using the Euler scheme and their stochastic counterparts through theoretical analysis and simulations.Based on this equivalence,we proposed an efficient model calibration method that could replicate the exact solution of CMs in the corresponding stochastic models through parameter adjustment.The advancement in calibration techniques enhanced the accuracy of stochastic modeling in capturing the dynamics of epidemics.However,it should be noted that discrete-time stochastic models cannot perfectly reproduce the exact solution of continuous-time CMs.Additionally,we proposed a new stochastic compartment and agent mixed model as an alternative to agent-based models for large-scale population simulations with a limited number of agents.This model offered a balance between computational efficiency and accuracy.The results of this research contributed to the comparison and unification of deterministic CMs and stochastic models in epidemic modeling.Furthermore,the results had implications for the development of hybrid models that integrated the strengths of both frameworks.Overall,the present study has provided valuable epidemic modeling techniques and their practical applications for understanding and controlling the spread of infectious diseases.展开更多
Background: Emerging evidence suggests that chemotherapy-induced peripheral neuropathy (CIPN) is a significant side effect of chemotherapeutic drugs. Many experiments have proved that sodium aescinate (SA) has definit...Background: Emerging evidence suggests that chemotherapy-induced peripheral neuropathy (CIPN) is a significant side effect of chemotherapeutic drugs. Many experiments have proved that sodium aescinate (SA) has definite pharmacological effects such as anti-infection, anti-exudation, anti-edema, anti-tumor as well as neuroprotection, and the drug side effects are mild. However, no study has explored whether SA is involved in the analgesic effect of paclitaxel (PAC) induced neuropathic pain in rats. Methods: Rats were given an intraperitoneal injection of PAC (2.5 mg/Kg intraperitoneally on days 1, 3, 5, and 7), while SA 25 mg/kg intraperitoneally was administered daily for 14 consecutive days. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) of rats were examined on experimental days 3, 5, 7, 11, 14. All rats were sacrificed on day 15 of the experiment, and L4-6 spinal cords were removed. Subsequently, immunohistochemistry, HE staining, ELISA, RT-qPCR, Western blotting were applied to evaluate cytoskeletal protein expression (NF-L and NF-M), spinal nerve structural integrity, proinflammatory factor contents (TNF-α, IL-1β, and IL-6), and protein content of the TLR4/NF-κB pathway, respectively. Results: After the rats developed PAC induced pain behaviors, multiple injections of SA rendered the rats with elevated MWT and TWL values, decreased expression of NF-L and NF-M in the spinal cord, materially downregulated content of proinflammatory factors, and reduced amounts of TLR4 and p-NF-κB protein levels. Conclusions: The results of the present study preliminarily indicate that SA has an analgesic effect on rats with CIPN induced by PAC injection, and the mechanism may be related to blocking the TLR4/NF-κB signaling pathway, inhibiting the expression of proinflammatory factors, and alleviating cytoskeletal disorders.展开更多
The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PG...The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PGO)with a P/O ratio of 8.5%was quickly synthesised by one-step electrochemical exfoliation based on a three-dimensiaonal(3D)printed reactor and natural graphite flakes.Compared with the GO prepared by the two-step electrochemical exfoliation method,the PGO synthesized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly(MEA)based on the polybenzimidazole(PBI)membrane in the HTPEMFC.The doping of 1.5 wt%GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4%or 35.4%compared to MEA based on pure PBI membrane at 150℃,respectively.In addition,the doping of PGO in PBI improves its durability under accelerated stress test(AST).展开更多
Purpose: This research evaluates the efficacy of astaxanthin (AX) on cerebral ischemia/reperfusion (I/R) injury in rats and elucidates the potential mechanism of its neuronal protective effect. Methods: Rats were subj...Purpose: This research evaluates the efficacy of astaxanthin (AX) on cerebral ischemia/reperfusion (I/R) injury in rats and elucidates the potential mechanism of its neuronal protective effect. Methods: Rats were subjected to a middle cerebral artery occlusion/reperfusion (MCAO/R) model. Fifty grown male Sprague-Dawley (SD) rats were divided into 5 groups, including sham operation group (Sham), MCAO/R group, MCAO/R+AX group, MCAO/R+ AX+ Scramble group and MCAO/R+AX+ si-PPAR-γ group. The neurological score and cerebral infarction volume were evaluated after surgery. Rat microglia (RM) were stimulated by lipopolysaccharide (LPS) to form an inflammatory environment. LPS-induced RM cells were incubated with different concentrations of AX (1, 5 or 10 μg/mL), then cell viability, the expression of microglial activation markers, including cytokines (IL-1β, IL-6 and TNF-α), cluster of differentiation 68 (CD68), inducible nitric oxide synthase (iNOS) and CD206 and the expression of PPAR-γ and phosphorylated P65 (p-P65) proteins were determined. Cells were treated with pcDNA-PPAR-γ, as well as treatment with si-PPAR-γ or PPAR-γ antagonist GW9662 before AX treatment, and then cell activation mediators were tested. Results: AX inhibits LPS-induced RM cells activation and enhanced the expression level of PPAR-γ protein in way of dose-dependent, and pcDNA-PPAR-γ treatment had the same effect as AX. While si-PPAR-γ transfection or PPAR-γ suppressant GW9662 treatment reversed the effect of AX, and cut down the level of PPAR-γ protein and augmented the level of p-P65 protein. In addition, AX treatment alleviated the infarct volume, and sensorimotor and cognitive functions of MCAO/R model rats. Conclusion: AX alleviates LPS-induced microglial injury and has a protective effect on rat cerebral I/R injury by regulating the PPAR-γ/NF-κB pathway.展开更多
Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows th...Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.展开更多
By allocating IP address and changing IP address in source and destination hosts, network address space randomization is committed to construct a dynamic and heterogeneous network to decrease the attacking possibility...By allocating IP address and changing IP address in source and destination hosts, network address space randomization is committed to construct a dynamic and heterogeneous network to decrease the attacking possibility and predictability. The research mainly deploys the features of OpenFlow network including data plane and control plane decoupling, centralized control of the network and dynamic updating of forwarding rules, combines the advantages of the network address space randomization technology with the features of the OpenFlow network, and designs a novel resolution towards IP conversion in Floodlight controller. The research can help improve the unpredictability and decrease the possibility of worm attacking and IP sniffing by IP allocation.展开更多
In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature ...In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature PEMFCs with lower Pt loading.On the one hand,Pt/Nr EGO_(2)-CB_(3)with the strong interaction between the Pt and nitrogen(N)prevent agglomeration of Pt particles and Pt particles is 5.46±1.46 nm,which is smaller than that of 6.78±1.34 nm in Pt/C.Meanwhile,ECSA of Pt/Nr EGO_(2)-CB_(3)decrease 13.65%after AST,which is much lower than that of 97.99%in Pt/C.On the other hand,the Nr EGO flakes in MEAac act as a barrier to mitigate phosphoric acid redistribution,which improves the formation of triple-phase boundaries(TPBs)and gives stable operation of the MEAacwith a lower decay rate of 0.02 mV h^(-1)within100 h.After steady-state operation,the maximum power density of Pt/Nr EGO_(2)-CB_(3)(0.411 W cm^(-2))is three times higher than that of conventional Pt/C(0.134 W cm^(-2))in high-temperature PEMFCs.After AST,the mass transfer resistance of Pt/Nr EGO_(2)-CB_(3)electrode(0.560Ωcm^(2))is lower than that in Pt/C(0.728Ωcm^(2)).展开更多
Monitoring sample plots is important for the sustainable management of forest ecosystems.Acquiring resource data in the field is labor-intensive,time-consuming and expensive.With the rapid development of hardware tech...Monitoring sample plots is important for the sustainable management of forest ecosystems.Acquiring resource data in the field is labor-intensive,time-consuming and expensive.With the rapid development of hardware technology and photogrammetry,forest researchers have turned two-dimensional images into three-dimensional point clouds to obtain resource information.This paper presents a method of sample plot analysis using two charge-coupled device(CCD) cameras based on video photography.A handheld CCD camera was used to shoot the sample plot by surrounding a central tree.Video-based point clouds were used to detect and model individual tree trunks in the sample plots and the DBH of each was estimated.The experimental results were compared with field measurement data.The results show that the relative root mean squared error(rRMSE) of the DBH estimates of individual trees was 2.1-5.7%,acceptable for practical applications in traditional forest inventories.The rRMSE of height estimates was2.7-36.3%.Average DBH and heights,and tree density and volume were calculated.Video-based methods require compact observation instruments,involve low costs during field investigations,acquire data with high efficiency,and point cloud data can be processed automatically.Furthermore,this method can directly extract information on the relative position of trees,which is important to show distribution visually and provides a basis for researchers to regulate stand density.Additionally,video photography with its unique advantages is a technology warranting future attention for forest inventories and ecological construction.展开更多
Objective: When nerve injury or inflammatory injury, different miRNA-mediated signal pathways are activated or inactivated, causing pain or hyperalgesia. Therefore, miRNA has become a new direction of pain mechanism r...Objective: When nerve injury or inflammatory injury, different miRNA-mediated signal pathways are activated or inactivated, causing pain or hyperalgesia. Therefore, miRNA has become a new direction of pain mechanism research. We aimed to investigate the effect and mechanism of miR-362-3p on neuropathic pain in rats with chronic sciatic nerve injury (CCI). Methods: Neuropathic pain CCI rat model was established. Real-time-quantitative polymerase chain reaction (RT-PCR), Western blot, immunofluorescence, intrathecal injection, Enzyme-linked immunosorbent assay (ELISA), and dual luciferase reporter gene assays were used to explore the role of miR-362-3p in neuropathic pain development and the relationship between miR-362-3p and JMJD1A (Jumonji domain-containing 1A). Results: In the CCI group, the miR-362-3p level was increased and JMJD1A level was reduced in spinal cords and isolated microglia. The paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) values were increased, the secretion of inflammatory factors was reduced, and the microglial marker Iba1 expression was decreased after intrathecal administration of miR-362-3p. miR-362-3p was observed to target JMJD1A. JMJD1A elevation abolished the inhibitory effects of miR-362-3p on neuropathic pain development. Conclusion: Intrathecal administration of miR-362-3p significantly relieved neuropathic pain in CCI rats and inhibited neuroinflammation possibly through regulating JMJD1A.展开更多
An explicit illustration of pulmonary delivery processes(PDPs)was a prerequisite for the formulation design and optimization of carrier-based DPIs.However,the current evaluation approaches for DPIs could not provide p...An explicit illustration of pulmonary delivery processes(PDPs)was a prerequisite for the formulation design and optimization of carrier-based DPIs.However,the current evaluation approaches for DPIs could not provide precise investigation of each PDP separately,or the approaches merely used a simplified and idealized model.In the present study,a novel modular modified Sympatec HELOS Real-time monitoring;Modular modification;Carrier;Air flow rate;Mechanism of drug delivery(MMSH)was developed to fully investigate the mechanism of each PDP separately in real-time.An inhaler device,artificial throat and pre-separator were separately integrated with a Sympatec HELOS.The dispersion and fluidization,transportation,detachment and deposition processes of pulmonary delivery for model DPIs were explored under different flow rates.Moreover,time-sliced measurements were used to monitor the PDPs in real-time.The Next Generation Impactor(NGI)was applied to determine the aerosolization performance of the model DPIs.The release profiles of the drug particles,drug aggregations and carriers were obtained by MMSH in real-time.Each PDP of the DPIs was analyzed in detail.Moreover,a positive correlation was established between the total release amount of drug particles and the fine particle fraction(FPF)values(R^2=0.9898).The innovative MMSH was successfully developed and was capable of illustrating the PDPs and the mechanism of carrier-based DPIs,providing a theoretical basis for the design and optimization of carrier-based DPIs.展开更多
Dry powder inhalers(DPIs) had been widely used in lung diseases on account of direct pulmonary delivery, good drug stability and satisfactory patient compliance. However, an indistinct understanding of pulmonary deliv...Dry powder inhalers(DPIs) had been widely used in lung diseases on account of direct pulmonary delivery, good drug stability and satisfactory patient compliance. However, an indistinct understanding of pulmonary delivery processes(PDPs) hindered the development of DPIs. Most current evaluation methods explored the PDPs with over-simplified models, leading to uncompleted investigations of the whole or partial PDPs. In the present research, an innovative modular process analysis platform(MPAP) was applied to investigate the detailed mechanisms of each PDP of DPIs with different carrier particle sizes(CPS). The MPAP was composed of a laser particle size analyzer, an inhaler device,an artificial throat and a pre-separator, to investigate the fluidization and dispersion, transportation,detachment and deposition process of DPIs. The release profiles of drug, drug aggregation and carrier were monitored in real-time. The influence of CPS on PDPs and corresponding mechanisms were explored. The powder properties of the carriers were investigated by the optical profiler and Freeman Technology four powder rheometer. The next generation impactor was employed to explore the aerosolization performance of DPIs. The novel MPAP was successfully applied in exploring the comprehensive mechanism of PDPs, which had enormous potential to be used to investigate and develop DPIs.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.82173620 to Yang Zhao and 82041024 to Feng Chen)partially supported by the Bill&Melinda Gates Foundation(Grant No.INV-006371 to Feng Chen)Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘Deterministic compartment models(CMs)and stochastic models,including stochastic CMs and agent-based models,are widely utilized in epidemic modeling.However,the relationship between CMs and their corresponding stochastic models is not well understood.The present study aimed to address this gap by conducting a comparative study using the susceptible,exposed,infectious,and recovered(SEIR)model and its extended CMs from the coronavirus disease 2019 modeling literature.We demonstrated the equivalence of the numerical solution of CMs using the Euler scheme and their stochastic counterparts through theoretical analysis and simulations.Based on this equivalence,we proposed an efficient model calibration method that could replicate the exact solution of CMs in the corresponding stochastic models through parameter adjustment.The advancement in calibration techniques enhanced the accuracy of stochastic modeling in capturing the dynamics of epidemics.However,it should be noted that discrete-time stochastic models cannot perfectly reproduce the exact solution of continuous-time CMs.Additionally,we proposed a new stochastic compartment and agent mixed model as an alternative to agent-based models for large-scale population simulations with a limited number of agents.This model offered a balance between computational efficiency and accuracy.The results of this research contributed to the comparison and unification of deterministic CMs and stochastic models in epidemic modeling.Furthermore,the results had implications for the development of hybrid models that integrated the strengths of both frameworks.Overall,the present study has provided valuable epidemic modeling techniques and their practical applications for understanding and controlling the spread of infectious diseases.
文摘Background: Emerging evidence suggests that chemotherapy-induced peripheral neuropathy (CIPN) is a significant side effect of chemotherapeutic drugs. Many experiments have proved that sodium aescinate (SA) has definite pharmacological effects such as anti-infection, anti-exudation, anti-edema, anti-tumor as well as neuroprotection, and the drug side effects are mild. However, no study has explored whether SA is involved in the analgesic effect of paclitaxel (PAC) induced neuropathic pain in rats. Methods: Rats were given an intraperitoneal injection of PAC (2.5 mg/Kg intraperitoneally on days 1, 3, 5, and 7), while SA 25 mg/kg intraperitoneally was administered daily for 14 consecutive days. The mechanical withdrawal threshold (MWT) and thermal withdrawal latency (TWL) of rats were examined on experimental days 3, 5, 7, 11, 14. All rats were sacrificed on day 15 of the experiment, and L4-6 spinal cords were removed. Subsequently, immunohistochemistry, HE staining, ELISA, RT-qPCR, Western blotting were applied to evaluate cytoskeletal protein expression (NF-L and NF-M), spinal nerve structural integrity, proinflammatory factor contents (TNF-α, IL-1β, and IL-6), and protein content of the TLR4/NF-κB pathway, respectively. Results: After the rats developed PAC induced pain behaviors, multiple injections of SA rendered the rats with elevated MWT and TWL values, decreased expression of NF-L and NF-M in the spinal cord, materially downregulated content of proinflammatory factors, and reduced amounts of TLR4 and p-NF-κB protein levels. Conclusions: The results of the present study preliminarily indicate that SA has an analgesic effect on rats with CIPN induced by PAC injection, and the mechanism may be related to blocking the TLR4/NF-κB signaling pathway, inhibiting the expression of proinflammatory factors, and alleviating cytoskeletal disorders.
基金financially supported by the UK Research Council EPSRC EP/009050/1。
文摘The doping of functionalized graphene oxide(GO)in the membranes becomes a promising method for improving the performance of high-temperature proton exchange membrane fuel cells(HT-PEMFC).Phosphonated graphene oxide(PGO)with a P/O ratio of 8.5%was quickly synthesised by one-step electrochemical exfoliation based on a three-dimensiaonal(3D)printed reactor and natural graphite flakes.Compared with the GO prepared by the two-step electrochemical exfoliation method,the PGO synthesized by the one-step electrochemical exfoliation can better improve the performance of the membrane-electrode-assembly(MEA)based on the polybenzimidazole(PBI)membrane in the HTPEMFC.The doping of 1.5 wt%GO synthesised by electrochemical exfoliation with the 2-step method or reactor method in PBI increased the peak power density by 17.4%or 35.4%compared to MEA based on pure PBI membrane at 150℃,respectively.In addition,the doping of PGO in PBI improves its durability under accelerated stress test(AST).
文摘Purpose: This research evaluates the efficacy of astaxanthin (AX) on cerebral ischemia/reperfusion (I/R) injury in rats and elucidates the potential mechanism of its neuronal protective effect. Methods: Rats were subjected to a middle cerebral artery occlusion/reperfusion (MCAO/R) model. Fifty grown male Sprague-Dawley (SD) rats were divided into 5 groups, including sham operation group (Sham), MCAO/R group, MCAO/R+AX group, MCAO/R+ AX+ Scramble group and MCAO/R+AX+ si-PPAR-γ group. The neurological score and cerebral infarction volume were evaluated after surgery. Rat microglia (RM) were stimulated by lipopolysaccharide (LPS) to form an inflammatory environment. LPS-induced RM cells were incubated with different concentrations of AX (1, 5 or 10 μg/mL), then cell viability, the expression of microglial activation markers, including cytokines (IL-1β, IL-6 and TNF-α), cluster of differentiation 68 (CD68), inducible nitric oxide synthase (iNOS) and CD206 and the expression of PPAR-γ and phosphorylated P65 (p-P65) proteins were determined. Cells were treated with pcDNA-PPAR-γ, as well as treatment with si-PPAR-γ or PPAR-γ antagonist GW9662 before AX treatment, and then cell activation mediators were tested. Results: AX inhibits LPS-induced RM cells activation and enhanced the expression level of PPAR-γ protein in way of dose-dependent, and pcDNA-PPAR-γ treatment had the same effect as AX. While si-PPAR-γ transfection or PPAR-γ suppressant GW9662 treatment reversed the effect of AX, and cut down the level of PPAR-γ protein and augmented the level of p-P65 protein. In addition, AX treatment alleviated the infarct volume, and sensorimotor and cognitive functions of MCAO/R model rats. Conclusion: AX alleviates LPS-induced microglial injury and has a protective effect on rat cerebral I/R injury by regulating the PPAR-γ/NF-κB pathway.
基金supported by the Engineering and Physical Sciences Research Council (EPSRC) EP/P009050/1 and EP/S021531/1the Henry Royce Institute for Advanced Materials, funded through the EPSRC grants EP/R00661X/1, EP/S019367/1, EP/P025021/1 and EP/P025498/1funding from the European Commission H2020ERC Starter grant Evolu TEM (715502)。
文摘Nitrogen doping of the carbon is an important method to improve the performance and durability of catalysts for proton exchange membrane fuel cells by platinum–nitrogen and carbon–nitrogen bonds. This study shows that p-phenyl groups and graphitic N acting bridges linking platinum and the graphene/carbon black(the ratio graphene/carbon black = 2/3) hybrid support materials achieved the average size of platinum nanoparticles with(4.88 ± 1.79) nm. It improved the performance of the lower-temperature hydrogen fuel cell up to 0.934 W cm^(-2) at 0.60 V, which is 1.55 times greater than that of commercial Pt/C. Doping also enhanced the interaction between Pt and the support materials, and the resistance to corrosion, thus improving the durability of the low-temperature hydrogen fuel cell with a much lower decay of 10 mV at 0.80 A cm^(-2) after 30 k cycles of an in-situ accelerated stress test of catalyst degradation than that of 92 mV in Pt/C, which achieves the target of Department of Energy(<30 mV). Meanwhile,Pt/Nr EGO_(2)-CB_(3) remains 78% of initial power density at 1.5 A cm^(-2) after 5 k cycles of in-situ accelerated stress test of carbon corrosion, which is more stable than the power density of commercial Pt/C, keeping only 54% after accelerated stress test.
文摘By allocating IP address and changing IP address in source and destination hosts, network address space randomization is committed to construct a dynamic and heterogeneous network to decrease the attacking possibility and predictability. The research mainly deploys the features of OpenFlow network including data plane and control plane decoupling, centralized control of the network and dynamic updating of forwarding rules, combines the advantages of the network address space randomization technology with the features of the OpenFlow network, and designs a novel resolution towards IP conversion in Floodlight controller. The research can help improve the unpredictability and decrease the possibility of worm attacking and IP sniffing by IP allocation.
基金supported by the Engineering and Physical Sciences Research Council(EPSRC)(EP/P009050/1 and EP/S021531/1)Tthe Henry Royce Institute for Advanced Materials,funded through the EPSRC grants(EP/R00661X/1,EP/S019367/1,EP/P025021/1 and EP/P025498/1)。
文摘In this study,nitrogen doped electrochemically exfoliated reduced graphene oxide and carbon black supported platinum(Pt/Nr EGO_(2)-CB_(3))has been prepared to enhance the performance and durability of hightemperature PEMFCs with lower Pt loading.On the one hand,Pt/Nr EGO_(2)-CB_(3)with the strong interaction between the Pt and nitrogen(N)prevent agglomeration of Pt particles and Pt particles is 5.46±1.46 nm,which is smaller than that of 6.78±1.34 nm in Pt/C.Meanwhile,ECSA of Pt/Nr EGO_(2)-CB_(3)decrease 13.65%after AST,which is much lower than that of 97.99%in Pt/C.On the other hand,the Nr EGO flakes in MEAac act as a barrier to mitigate phosphoric acid redistribution,which improves the formation of triple-phase boundaries(TPBs)and gives stable operation of the MEAacwith a lower decay rate of 0.02 mV h^(-1)within100 h.After steady-state operation,the maximum power density of Pt/Nr EGO_(2)-CB_(3)(0.411 W cm^(-2))is three times higher than that of conventional Pt/C(0.134 W cm^(-2))in high-temperature PEMFCs.After AST,the mass transfer resistance of Pt/Nr EGO_(2)-CB_(3)electrode(0.560Ωcm^(2))is lower than that in Pt/C(0.728Ωcm^(2)).
基金funded partly by the National Natural Science Foundation of China (Grant number funded this research U1710123)the Fundamental Research Funds for the Central Universities (No.2015ZCQ-LX-01)。
文摘Monitoring sample plots is important for the sustainable management of forest ecosystems.Acquiring resource data in the field is labor-intensive,time-consuming and expensive.With the rapid development of hardware technology and photogrammetry,forest researchers have turned two-dimensional images into three-dimensional point clouds to obtain resource information.This paper presents a method of sample plot analysis using two charge-coupled device(CCD) cameras based on video photography.A handheld CCD camera was used to shoot the sample plot by surrounding a central tree.Video-based point clouds were used to detect and model individual tree trunks in the sample plots and the DBH of each was estimated.The experimental results were compared with field measurement data.The results show that the relative root mean squared error(rRMSE) of the DBH estimates of individual trees was 2.1-5.7%,acceptable for practical applications in traditional forest inventories.The rRMSE of height estimates was2.7-36.3%.Average DBH and heights,and tree density and volume were calculated.Video-based methods require compact observation instruments,involve low costs during field investigations,acquire data with high efficiency,and point cloud data can be processed automatically.Furthermore,this method can directly extract information on the relative position of trees,which is important to show distribution visually and provides a basis for researchers to regulate stand density.Additionally,video photography with its unique advantages is a technology warranting future attention for forest inventories and ecological construction.
文摘Objective: When nerve injury or inflammatory injury, different miRNA-mediated signal pathways are activated or inactivated, causing pain or hyperalgesia. Therefore, miRNA has become a new direction of pain mechanism research. We aimed to investigate the effect and mechanism of miR-362-3p on neuropathic pain in rats with chronic sciatic nerve injury (CCI). Methods: Neuropathic pain CCI rat model was established. Real-time-quantitative polymerase chain reaction (RT-PCR), Western blot, immunofluorescence, intrathecal injection, Enzyme-linked immunosorbent assay (ELISA), and dual luciferase reporter gene assays were used to explore the role of miR-362-3p in neuropathic pain development and the relationship between miR-362-3p and JMJD1A (Jumonji domain-containing 1A). Results: In the CCI group, the miR-362-3p level was increased and JMJD1A level was reduced in spinal cords and isolated microglia. The paw withdrawal threshold (PWT) and paw withdrawal latency (PWL) values were increased, the secretion of inflammatory factors was reduced, and the microglial marker Iba1 expression was decreased after intrathecal administration of miR-362-3p. miR-362-3p was observed to target JMJD1A. JMJD1A elevation abolished the inhibitory effects of miR-362-3p on neuropathic pain development. Conclusion: Intrathecal administration of miR-362-3p significantly relieved neuropathic pain in CCI rats and inhibited neuroinflammation possibly through regulating JMJD1A.
基金funded by the National Natural Science Foundation of China(81673375 and 81703431)the Science and Technology Foundation Guangzhou(201509030006,China)the National Students Innovation Training Program of China(201901390)
文摘An explicit illustration of pulmonary delivery processes(PDPs)was a prerequisite for the formulation design and optimization of carrier-based DPIs.However,the current evaluation approaches for DPIs could not provide precise investigation of each PDP separately,or the approaches merely used a simplified and idealized model.In the present study,a novel modular modified Sympatec HELOS Real-time monitoring;Modular modification;Carrier;Air flow rate;Mechanism of drug delivery(MMSH)was developed to fully investigate the mechanism of each PDP separately in real-time.An inhaler device,artificial throat and pre-separator were separately integrated with a Sympatec HELOS.The dispersion and fluidization,transportation,detachment and deposition processes of pulmonary delivery for model DPIs were explored under different flow rates.Moreover,time-sliced measurements were used to monitor the PDPs in real-time.The Next Generation Impactor(NGI)was applied to determine the aerosolization performance of the model DPIs.The release profiles of the drug particles,drug aggregations and carriers were obtained by MMSH in real-time.Each PDP of the DPIs was analyzed in detail.Moreover,a positive correlation was established between the total release amount of drug particles and the fine particle fraction(FPF)values(R^2=0.9898).The innovative MMSH was successfully developed and was capable of illustrating the PDPs and the mechanism of carrier-based DPIs,providing a theoretical basis for the design and optimization of carrier-based DPIs.
基金funded by the Fundamental Research Funds for the Central Universities(Nos.21620434 and 2162014,China)the National Natural Science Foundation of China(Nos.81673375 and 81703431)+1 种基金the Science and Technology Foundation Guangzhou(No.201509030006,China)the National Students Innovation Training Program of China(No.201901390,China)。
文摘Dry powder inhalers(DPIs) had been widely used in lung diseases on account of direct pulmonary delivery, good drug stability and satisfactory patient compliance. However, an indistinct understanding of pulmonary delivery processes(PDPs) hindered the development of DPIs. Most current evaluation methods explored the PDPs with over-simplified models, leading to uncompleted investigations of the whole or partial PDPs. In the present research, an innovative modular process analysis platform(MPAP) was applied to investigate the detailed mechanisms of each PDP of DPIs with different carrier particle sizes(CPS). The MPAP was composed of a laser particle size analyzer, an inhaler device,an artificial throat and a pre-separator, to investigate the fluidization and dispersion, transportation,detachment and deposition process of DPIs. The release profiles of drug, drug aggregation and carrier were monitored in real-time. The influence of CPS on PDPs and corresponding mechanisms were explored. The powder properties of the carriers were investigated by the optical profiler and Freeman Technology four powder rheometer. The next generation impactor was employed to explore the aerosolization performance of DPIs. The novel MPAP was successfully applied in exploring the comprehensive mechanism of PDPs, which had enormous potential to be used to investigate and develop DPIs.
