BACKGROUND In-hospital cardiac arrest(IHCA) portends a poor prognosis and survival to discharge rate. Prognostic markers such as interleukin-6, S-100 protein and high sensitivity C reactive protein have been studied a...BACKGROUND In-hospital cardiac arrest(IHCA) portends a poor prognosis and survival to discharge rate. Prognostic markers such as interleukin-6, S-100 protein and high sensitivity C reactive protein have been studied as predictors of adverse outcomes after return of spontaneous circulation(ROSC); however; these variables are not routine laboratory tests and incur additional cost making them difficult to incorporate and less attractive in assessing patient's prognosis. The neutrophil-lymphocyte ratio(NLR) is a marker of adverse prognosis for many cardiovascular conditions and certain types of cancers and sepsis. We hypothesize that an elevated NLR is associated with poor outcomes including mortality at discharge in patients with IHCA.AIM To determine the prognostic significance of NLR in patients suffering IHCA who achieve ROSC.METHODS A retrospective study was performed on all patients who had IHCA with the advanced cardiac life support protocol administered in a large urban community United States hospital over a one-year period. Patients were divided into two groups based on their NLR value(NLR < 4.5 or NLR ≥ 4.5). This cutpoint was derived from receiving operator characteristic curve analysis(area under the curve = 0.66) and provided 73% positive predictive value, 82% sensitivity and42% specificity for predicting in-hospital death after IHCA. The primary outcome was death or discharge at 30 d, whichever came first.RESULTS We reviewed 153 patients with a mean age of 66.1 ± 16.3 years; 48% were female.In-hospital mortality occurred in 65%. The median NLR in survivors was 4.9(range 0.6-46.5) compared with 8.9(0.28-96) in non-survivors(P = 0.001). A multivariable logistic regression model demonstrated that an NLR above 4.55[odds ratio(OR) = 5.20, confidence interval(CI): 1.5-18.3, P = 0.01], older age(OR= 1.03, CI: 1.00-1.07, P = 0.05), and elevated serum lactate level(OR = 1.20, CI:1.03-1.40, P = 0.02) were independent predictors of death.CONCLUSION An NLR ≥ 4.5 may be a useful marker of increased risk of death in patients with IHCA.展开更多
A simplified approach is introduced to model production from shale gas resources. In this approach, a multi-fractured horizontal gas well in a shale formation is divided into four zones. Shale formation between each p...A simplified approach is introduced to model production from shale gas resources. In this approach, a multi-fractured horizontal gas well in a shale formation is divided into four zones. Shale formation between each pair of hydraulic fractures consists of four zones: compacted zone around well-bore (1), shale matrix (2), induced fractures (3) and main hydraulic fractures (4). The main contribution of this study is considering varying permeability for each specific zone implemented in the mathematical presentation of gas flow in shale. Further, gas desorption and slippage effect are applied to the model to capture the realistic gas flow in shale. The nonlinear partial differential equation of gas flow obtained from mass conservations law is then solved numerically for each specific zone with respect to their appropriate boundary conditions. This approach then is applied to three case studies, Cooper Basin, Georgina and Galilee shale. A history matching of the mentioned formations is accomplished to find the most uncertain parameters undertaken through this simplified approach. Results of this study are in an agreement with other methods and it is demonstrated that the simplified approach provides more accurate production forecast for the well-established Georgina asset and is in a good agreement for Cooper and Galilee. This study is also valuable since it provides some rough estimation for shale rock characteristics as the basis for rigorous simulation studies.展开更多
In this review we summarize the progress made towards understanding the role of protein-protein interactions in the function of various bioluminescence systems of marine organisms,including bacteria,jellyfish and soft...In this review we summarize the progress made towards understanding the role of protein-protein interactions in the function of various bioluminescence systems of marine organisms,including bacteria,jellyfish and soft corals,with particular focus on methodology used to detect and characterize these interactions.In some bioluminescence systems,protein-protein interactions involve an“accessory protein”whereby a stored substrate is efficiently delivered to the bioluminescent enzyme luciferase.Other types of complexation mediate energy transfer to an“antenna protein”altering the color and quantum yield of a bioluminescence reaction.Spatial structures of the complexes reveal an important role of electrostatic forces in governing the corresponding weak interactions and define the nature of the interaction surfaces.The most reliable structural model is available for the protein-protein complex of the Ca2+-regulated photoprotein clytin and green-fluorescent protein(GFP)from the jellyfish Clytia gregaria,solved by means of Xray crystallography,NMR mapping and molecular docking.This provides an example of the potential strategies in studying the transient complexes involved in bioluminescence.It is emphasized that structural studies such as these can provide valuable insight into the detailed mechanism of bioluminescence.展开更多
文摘BACKGROUND In-hospital cardiac arrest(IHCA) portends a poor prognosis and survival to discharge rate. Prognostic markers such as interleukin-6, S-100 protein and high sensitivity C reactive protein have been studied as predictors of adverse outcomes after return of spontaneous circulation(ROSC); however; these variables are not routine laboratory tests and incur additional cost making them difficult to incorporate and less attractive in assessing patient's prognosis. The neutrophil-lymphocyte ratio(NLR) is a marker of adverse prognosis for many cardiovascular conditions and certain types of cancers and sepsis. We hypothesize that an elevated NLR is associated with poor outcomes including mortality at discharge in patients with IHCA.AIM To determine the prognostic significance of NLR in patients suffering IHCA who achieve ROSC.METHODS A retrospective study was performed on all patients who had IHCA with the advanced cardiac life support protocol administered in a large urban community United States hospital over a one-year period. Patients were divided into two groups based on their NLR value(NLR < 4.5 or NLR ≥ 4.5). This cutpoint was derived from receiving operator characteristic curve analysis(area under the curve = 0.66) and provided 73% positive predictive value, 82% sensitivity and42% specificity for predicting in-hospital death after IHCA. The primary outcome was death or discharge at 30 d, whichever came first.RESULTS We reviewed 153 patients with a mean age of 66.1 ± 16.3 years; 48% were female.In-hospital mortality occurred in 65%. The median NLR in survivors was 4.9(range 0.6-46.5) compared with 8.9(0.28-96) in non-survivors(P = 0.001). A multivariable logistic regression model demonstrated that an NLR above 4.55[odds ratio(OR) = 5.20, confidence interval(CI): 1.5-18.3, P = 0.01], older age(OR= 1.03, CI: 1.00-1.07, P = 0.05), and elevated serum lactate level(OR = 1.20, CI:1.03-1.40, P = 0.02) were independent predictors of death.CONCLUSION An NLR ≥ 4.5 may be a useful marker of increased risk of death in patients with IHCA.
文摘A simplified approach is introduced to model production from shale gas resources. In this approach, a multi-fractured horizontal gas well in a shale formation is divided into four zones. Shale formation between each pair of hydraulic fractures consists of four zones: compacted zone around well-bore (1), shale matrix (2), induced fractures (3) and main hydraulic fractures (4). The main contribution of this study is considering varying permeability for each specific zone implemented in the mathematical presentation of gas flow in shale. Further, gas desorption and slippage effect are applied to the model to capture the realistic gas flow in shale. The nonlinear partial differential equation of gas flow obtained from mass conservations law is then solved numerically for each specific zone with respect to their appropriate boundary conditions. This approach then is applied to three case studies, Cooper Basin, Georgina and Galilee shale. A history matching of the mentioned formations is accomplished to find the most uncertain parameters undertaken through this simplified approach. Results of this study are in an agreement with other methods and it is demonstrated that the simplified approach provides more accurate production forecast for the well-established Georgina asset and is in a good agreement for Cooper and Galilee. This study is also valuable since it provides some rough estimation for shale rock characteristics as the basis for rigorous simulation studies.
基金by“Fellowship for Young International Scientists”of Chinese Academy of SciencesThis work was supported by the National Natural Science Foundation of China(Grant Nos:30870483,31070660,31021062 and 81072449)+1 种基金Ministry of Science and Technology of China(Nos.2009DFB30310,2009CB918803 and 2011CB911103)CAS Research Grants(Nos.YZ200839 and KSCX2-EW-J-3).
文摘In this review we summarize the progress made towards understanding the role of protein-protein interactions in the function of various bioluminescence systems of marine organisms,including bacteria,jellyfish and soft corals,with particular focus on methodology used to detect and characterize these interactions.In some bioluminescence systems,protein-protein interactions involve an“accessory protein”whereby a stored substrate is efficiently delivered to the bioluminescent enzyme luciferase.Other types of complexation mediate energy transfer to an“antenna protein”altering the color and quantum yield of a bioluminescence reaction.Spatial structures of the complexes reveal an important role of electrostatic forces in governing the corresponding weak interactions and define the nature of the interaction surfaces.The most reliable structural model is available for the protein-protein complex of the Ca2+-regulated photoprotein clytin and green-fluorescent protein(GFP)from the jellyfish Clytia gregaria,solved by means of Xray crystallography,NMR mapping and molecular docking.This provides an example of the potential strategies in studying the transient complexes involved in bioluminescence.It is emphasized that structural studies such as these can provide valuable insight into the detailed mechanism of bioluminescence.
