Endothelial dysfunction contributes to the development of acute kidney injury (AKI) in animal models of ischemia reperfusion injury and sepsis. There are limited data on markers of endothelial dysfunction in human AKI. We hypothesized that Protein C (PC) and soluble thrombomodulin (sTM) levels could predict AKI. We conducted a multicenter prospective study in 80 patients to assess the relationship of PC and sTM levels to AKI, defined by the AKIN creatinine (AKI Scr) and urine output criteria (AKI UO). We measured marker levels for up to 10 days from intensive care unit admission. We used area under the curve (AUC) and time-dependent multivariable Cox proportional hazard model to predict AKI and logistic regression to predict mortality/non-renal recovery. Protein C and sTM were not different in patients with AKI UO only versus no AKI. On intensive care unit admission, as PC levels are usually lower with AKI Scr, the AUC to predict the absence of AKI was 0.63 (95%CI 0.44-0.78). The AUC using log10 sTM levels to predict AKI was 0.77 (95%CI 0.62-0.89), which predicted AKI Scr better than serum and urine neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C, urine kidney injury molecule-1 and liver-fatty acid-binding protein. In multivariable models, PC and urine NGAL levels independently predicted AKI (p=0.04 and 0.02) and PC levels independently predicted mortality/non-renal recovery (p=0.04). In our study, PC and sTM levels can predict AKI Scr but are not modified during AKI UO alone. PC levels could independently predict mortality/non-renal recovery. Additional larger studies are needed to define the relationship between markers of endothelial dysfunction and AKI.
In this study, the perovskite layers were prepared by two-step wet process with different CH3NH3I (MAI) concentrations. The cell structure was glass/FTO/TiO2-mesoporous/CH3NH3PbI3 (MAPbI3)/spiro-OMeTAD/Ag. The MAPbI3 perovskite films were prepared using high and low MAI concentrations in a two-step process. The perovskite films were optimized at different spin coating speed and different annealing temperatures to enhance the power conversion efficiency (PCE) of perovskite solar cells. The PCE of the resulting device based on the different perovskite morphologies was discussed. The PCE of the best cell was up to 17.42%, open circuit voltage of 0.97 V, short current density of 24.06 mA/cm2, and fill factor of 0.747.
Developing
efficient bifunctional electrocatalysts in
neutral media
to avoid the deterioration of electrodes or catalysts under harsh
environments has become the ultimate goal in electrochemical water
splitting. This work demonstrates the fabrication of an on-chip bifunctional
two-dimensional (2D) monolayer (ML) WSe2/graphene heterojunction
microreactor for efficient overall water splitting in a neutral medium
(pH = 7). Through the synergistic atomic growth of the metallic Cr
dopant and graphene stitching contact on the 2D ML WSe2, the bifunctional WSe2/graphene heterojunction microreactor
consisting of a full-cell configuration demonstrates excellent performance
for overall water splitting in a neutral medium. Atomic doping of
metallic Cr atoms onto the 2D ML WSe2 effectively facilitates
the charge transfer at the solid–liquid interface. In addition,
the direct growth of the self-stitching graphene contact with the
2D WSe2 catalyst largely reduces the contact resistance
of the microreactor and further improves the overall water splitting
efficiency. A significant reduction of the overpotential of nearly
1000 mV at 10 mA cm–2 at the Cr-doped WSe2/graphene heterojunction microreactor compared to the ML pristine
WSe2 counterpart is achieved. The bifunctional WSe2/graphene self-stitching heterojunction microreactor is an
ideal platform to investigate the fundamental mechanism of emerging
bifunctional 2D catalysts for overall water splitting in a neutral
medium.
We demonstrate a method to enhance the power conversion efficiency (PCE) of MAPbI3 perovskite solar cells through localized surface plasmon (LSP) coupling with gold nanoparticles:CsPbBr3 hybrid perovskite quantum dots (AuNPs:QD-CsPbBr3). The plasmonic AuNPs:QD-CsPbBr3 possess the features of high light-harvesting capacity and fast charge transfer through the LSP resonance effect, thus improving the short-circuit current density and the fill factor. Compared to the original device without Au NPs, a 27.8% enhancement in PCE of plasmonic AuNPs:QD-CsPbBr3/MAPbI3 perovskite solar cells was achieved upon 120 μL Au NP solution doping. This improvement can be attributed to the formation of surface plasmon resonance and light scattering effects in Au NPs embedded in QD-CsPbBr3, resulting in improved light absorption due to plasmonic nanoparticles.
A case study of applying LRFM (length, recency, frequency, and monetary) model and clustering techniques in evaluating an outfi tter's customer values is presented. Self-organizing maps is fi rst used to determine the best number of clusters and then K-means method is applied to classify 551 customers into twelve clusters when L, R, F, and M are the segmenting variables. The results show that Cluster 5 might be the most important cluster because the average values of L, R, F, and M are well above the averages. In contrast, the customers in Clusters 7 and 10 have low contributions since L, R, F, and M values are below the average values. As a result, with the applications of LRFM model and clustering techniques, the outfi tter can allocate and utilize resources eff ectively and eff iciently to fi rst identify high-value and profi t potential customers and then design diff erent marketing strategies to maximize its profi ts for diff erent types of clusters.
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