For a channel-shoal system in a funnel-shaped basin the impact of dredging and dumping is investigated using a complex process-based model. First, the residual flow and sediment transport circulations are analysed for...For a channel-shoal system in a funnel-shaped basin the impact of dredging and dumping is investigated using a complex process-based model. First, the residual flow and sediment transport circulations are analysed for the channel-shoal pattern, which has emerged after a longterm model simulation. Results are compared to the Western Scheldt estuary, which forms the inspiration for this study. Subsequently, different dredge and dump scenarios are modelled, according to a conceptual model, in which ebb- and flood-channels and enclosed shoals form morphodynamic units (cells) with their own sediment circulation. Model results show that dumping sediment in a channel further reduces the channel depth and induces erosion in the opposite channel, which enhances tilting of the cross-section of the cell and eventually can lead to the degeneration of a multiple channel system into a single channel. The impact of different dredging and dumping cases agrees with results from a stability analysis. This means that this type of model applied to a realistic geometry can potentially be used for better prediction of the impact of human interventions.展开更多
A novel methodology is presented for simultaneously optimizing synthesis and cleaning schedule of flexible heat exchanger network(HEN)by genetic/simulated annealing algorithms(GA/SA).Through taking into account the ef...A novel methodology is presented for simultaneously optimizing synthesis and cleaning schedule of flexible heat exchanger network(HEN)by genetic/simulated annealing algorithms(GA/SA).Through taking into account the effect of fouling process on optimal network topology,a preliminary network structure possessing two-fold oversynthesis is obtained by means of pseudo-temperature enthalpy(T-H)diagram approach prior to simultaneous optimization.Thus,the computational complexity of this problem classified as NP(Non-deterministic Polynomial)-complete can be significantly reduced.The promising matches resulting from preliminary synthesis stage are further optimized in parallel with their heat exchange areas and cleaning schedule.In addition,a novel continu- ous time representation is introduced to subdivide the given time horizon into several variable-size intervals according to operating periods of heat exchangers,and then flexible HEN synthesis can be implemented in dynamic manner.A numerical example is provided to demonstrate that the presented strategy is feasible to decrease the total annual cost(TAC)and further improve network flexibility,but even more important,it may be applied to solve large-scale flexible HEN synthesis problems.展开更多
The inflammatory cytokine interleukin-1 beta （IL-1β） plays a key role in the process of intervertebral disc degenera- tion （IVDD）. In the present study, we aimed to evaluate the effect of pharmaco-serum of ＂Taor...The inflammatory cytokine interleukin-1 beta （IL-1β） plays a key role in the process of intervertebral disc degenera- tion （IVDD）. In the present study, we aimed to evaluate the effect of pharmaco-serum of ＂Taoren-Honghua-herb pair＂ on IL-1β- induced chondrocyte degeneration in vitro. Taoren （Semen persicae） and Honghua （Safflower carthamus） were administered to the rats, and the pharmaco-serum was collected and prepared. Chondrocytes of the third passage, isolated from the rat＇s vertebral endplates, were treated by standard medium only （Group NC）, IL-1β （Group IL） or combination of IL-1β and pharmaco-serum （Group TRHH）. Cell proliferation and apoptosis were determined, and the expression of aggrecan, Col2ul, Coll0ul, IL-6 and SOX9 at the mRNA level in chondrocytes was quantified by real-time PCR. Immunohistochemistry staining of type II and X collagen and Safranine O staining were also used to evaluate the chondrocytes. Compared with the Group NC, IL-1β treatment inhibited the cell proliferation and induced the cell apoptosis （P〈0.05）, and the expression of aggrecan, Col2αl and SOX9 at the mRNA level was down-regulated. In contrast, the expression of Coll0ul and IL-6 was up-regulated after IL-1β treatment （P〈0.05）. Meanwhile, the immune-staining of type II collagen and Safranine O staining were decreased, while the staining of type X collagen was increased. Compared with the Group IL, cell proliferation was increased, and apoptosis of chondrocytes was decreased when cells were treated with the pharmaco-semm of TRHH-herb pair （P〈0.05）. The expression of aggrecan, Col2cd and SOX9 at the mRNA level was up-regulated, while that of Coll0cd and IL-6 was down-regulated （P〈0.05）. Saffanine O staining also showed increased positive staining （P〈0.05）. Taken together, the treatment of pharmaco-serum of TRHH-herb pair could prevent endplate chondrocyte degeneration induced by IL-1β.展开更多
This study aimed to investigate the serological characteristics of Ebola virus(EBOV) infection during the late phase of the Ebola outbreak in Sierra Leone. In total, 877 blood samples from 694 suspected Ebola virus di...This study aimed to investigate the serological characteristics of Ebola virus(EBOV) infection during the late phase of the Ebola outbreak in Sierra Leone. In total, 877 blood samples from 694 suspected Ebola virus disease(EVD) cases assessed from March to December 2015, were analyzed via real-time reverse transcription polymerase chain reaction(RT-PCR) for viral RNA and enzyme-linked immunosorbent assay(ELISA) and Luminex to detect antibodies against EBOV. Viral load and EBOV-specific IgM/IgG titers displayed a declining trend during March to December 2015. Viral RNA load decreased rapidly at earlier stages after disease onset, while EBOV-specific IgM and IgG still persisted in 58.1%(18/31) and 93.5%(29/31) of the confirmed EVD patients and in 3.8%(25/663) and 17.8%(118/663) of the RNA-negative suspected patients in the later phase, respectively. Dynamic analysis of longitudinally collected samples from eight EVD patients revealed typically reversed trends of declining viral load and increasing IgM and/or IgG titers in response to the EBOV infection.The present results indicate that certain populations of Sierra Leone developed immunity to an EBOV infection in the late phase of the outbreak, providing novel insights into the risk assessment of EBOV infections among human populations.展开更多
文摘For a channel-shoal system in a funnel-shaped basin the impact of dredging and dumping is investigated using a complex process-based model. First, the residual flow and sediment transport circulations are analysed for the channel-shoal pattern, which has emerged after a longterm model simulation. Results are compared to the Western Scheldt estuary, which forms the inspiration for this study. Subsequently, different dredge and dump scenarios are modelled, according to a conceptual model, in which ebb- and flood-channels and enclosed shoals form morphodynamic units (cells) with their own sediment circulation. Model results show that dumping sediment in a channel further reduces the channel depth and induces erosion in the opposite channel, which enhances tilting of the cross-section of the cell and eventually can lead to the degeneration of a multiple channel system into a single channel. The impact of different dredging and dumping cases agrees with results from a stability analysis. This means that this type of model applied to a realistic geometry can potentially be used for better prediction of the impact of human interventions.
基金Supported by the National Natural Science Foundation of China （20976022） and Dalian University of Technology for Constructing Interdiscipline ＇Energy＋X＇. ACKNOWLEDGEMENTS The authors gratefully acknowledge financial support from Lanzhou Petrochemical Company, PetroChina Company Limited.
文摘A novel methodology is presented for simultaneously optimizing synthesis and cleaning schedule of flexible heat exchanger network(HEN)by genetic/simulated annealing algorithms(GA/SA).Through taking into account the effect of fouling process on optimal network topology,a preliminary network structure possessing two-fold oversynthesis is obtained by means of pseudo-temperature enthalpy(T-H)diagram approach prior to simultaneous optimization.Thus,the computational complexity of this problem classified as NP(Non-deterministic Polynomial)-complete can be significantly reduced.The promising matches resulting from preliminary synthesis stage are further optimized in parallel with their heat exchange areas and cleaning schedule.In addition,a novel continu- ous time representation is introduced to subdivide the given time horizon into several variable-size intervals according to operating periods of heat exchangers,and then flexible HEN synthesis can be implemented in dynamic manner.A numerical example is provided to demonstrate that the presented strategy is feasible to decrease the total annual cost(TAC)and further improve network flexibility,but even more important,it may be applied to solve large-scale flexible HEN synthesis problems.
基金National Natural Science Foundation of China(Grant No.81273777,81102606,81072831)the National Basic Re search Program of China(Grant No.2010CB530400)the Program for Changjiang Scholars and Innovative Research Team in University(PCSIRT,IRT1270)
文摘The inflammatory cytokine interleukin-1 beta （IL-1β） plays a key role in the process of intervertebral disc degenera- tion （IVDD）. In the present study, we aimed to evaluate the effect of pharmaco-serum of ＂Taoren-Honghua-herb pair＂ on IL-1β- induced chondrocyte degeneration in vitro. Taoren （Semen persicae） and Honghua （Safflower carthamus） were administered to the rats, and the pharmaco-serum was collected and prepared. Chondrocytes of the third passage, isolated from the rat＇s vertebral endplates, were treated by standard medium only （Group NC）, IL-1β （Group IL） or combination of IL-1β and pharmaco-serum （Group TRHH）. Cell proliferation and apoptosis were determined, and the expression of aggrecan, Col2ul, Coll0ul, IL-6 and SOX9 at the mRNA level in chondrocytes was quantified by real-time PCR. Immunohistochemistry staining of type II and X collagen and Safranine O staining were also used to evaluate the chondrocytes. Compared with the Group NC, IL-1β treatment inhibited the cell proliferation and induced the cell apoptosis （P〈0.05）, and the expression of aggrecan, Col2αl and SOX9 at the mRNA level was down-regulated. In contrast, the expression of Coll0ul and IL-6 was up-regulated after IL-1β treatment （P〈0.05）. Meanwhile, the immune-staining of type II collagen and Safranine O staining were decreased, while the staining of type X collagen was increased. Compared with the Group IL, cell proliferation was increased, and apoptosis of chondrocytes was decreased when cells were treated with the pharmaco-semm of TRHH-herb pair （P〈0.05）. The expression of aggrecan, Col2cd and SOX9 at the mRNA level was up-regulated, while that of Coll0cd and IL-6 was down-regulated （P〈0.05）. Saffanine O staining also showed increased positive staining （P〈0.05）. Taken together, the treatment of pharmaco-serum of TRHH-herb pair could prevent endplate chondrocyte degeneration induced by IL-1β.
基金supported by National Mega project for Infectious Disease,Ministry of Science and technology(Grant Nos.2016ZX10004222-002,2016ZX10004222-003)National Natural Science Foundation of China(Grant Nos.81373141 and 81401312)National key project of Ebola research,National Natural Science Foundation of China(NSFC,Grant No.81590763)
文摘This study aimed to investigate the serological characteristics of Ebola virus(EBOV) infection during the late phase of the Ebola outbreak in Sierra Leone. In total, 877 blood samples from 694 suspected Ebola virus disease(EVD) cases assessed from March to December 2015, were analyzed via real-time reverse transcription polymerase chain reaction(RT-PCR) for viral RNA and enzyme-linked immunosorbent assay(ELISA) and Luminex to detect antibodies against EBOV. Viral load and EBOV-specific IgM/IgG titers displayed a declining trend during March to December 2015. Viral RNA load decreased rapidly at earlier stages after disease onset, while EBOV-specific IgM and IgG still persisted in 58.1%(18/31) and 93.5%(29/31) of the confirmed EVD patients and in 3.8%(25/663) and 17.8%(118/663) of the RNA-negative suspected patients in the later phase, respectively. Dynamic analysis of longitudinally collected samples from eight EVD patients revealed typically reversed trends of declining viral load and increasing IgM and/or IgG titers in response to the EBOV infection.The present results indicate that certain populations of Sierra Leone developed immunity to an EBOV infection in the late phase of the outbreak, providing novel insights into the risk assessment of EBOV infections among human populations.
