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BACKGROUND:Cranial sonography is a widely used point-of-care modality in infants. The authors evaluated that the ...respiratory variation of the internal carotid artery blood flow peak velocity as measured using transfontanelle ultrasound can predict fluid responsiveness in infants.
METHODS:This prospective observational study included 30 infants undergoing cardiac surgery. Following closure of the sternum, before and after the administration of 10ml · kg crystalloid, the respiratory variation of the aorta blood flow peak velocity, pulse pressure variation, and central venous pressure were obtained. The respiratory variation of the internal carotid artery blood flow peak velocity was measured using transfontanelle ultrasound. Response to fluid administration was defined as an increase in stroke volume index, as measured with transesophageal echocardiography, greater than 15% of baseline.
RESULTS:Seventeen subjects (57%) were responders to volume expansion. Before fluid loading, the respiratory variation of the internal carotid artery and the aorta blood flow peak velocity (means ± SD) of the responders were 12.6 ± 3.3% and 16.0 ± 3.8%, and those of the nonresponders were 8.2 ± 3.2% and 10.9 ± 3.5%, respectively. Receiver operating characteristic curve analysis showed that the respiratory variation of the internal carotid artery and the aorta blood flow peak velocity could predict fluid responsiveness; the area under the curve was 0.828 (P < 0.0001; 95% CI, 0.647 to 0.940) and 0.86 (P = 0.0001; 95% CI, 0.684 to 0.959), respectively. The cutoff values of the respiratory variation of the internal carotid artery and the aorta blood flow peak velocity were 7.8% (sensitivity, 94%; specificity, 69%) and 13% (sensitivity, 77%; specificity, 92%), respectively.
CONCLUSIONS:The respiratory variation of the internal carotid artery blood flow peak velocity as measured using transfontanelle ultrasound predicted an increase in stroke volume in response to fluid. Further research is required to establish any wider generalizability of the results.
•Heterologous expression of glycerol reductive pathway in E. coli BL21 was assessed.•Positive potential shifted the metabolic flux toward oxidative 3-HP pathway.•Negative potential drove microbial ...reduction and enhanced 1,3-PDO production.•Non-transcriptional metabolic control was demonstrated by electrochemical reaction.
Electrode-based metabolic regulation is an effective tool for shifting metabolic fluxes by controlling the intracellular redox balance. This paper reports an electrode-assisted non-native pathway regulation using a model recombinant strain of non-electrogenic (or weak electrogenic) bacteria, E. coli BL21(DE3) ΔglpK harboring glycerol reductive pathways to produce 3-hydroxypropionic acid (NAD+ dependent metabolite) or 1,3-propanediol (NADH dependent metabolite). The potentiostat, poising potential on electrode, induced a change in intracellular redox state via bacteria-electrode electron transfer (bacteria to the electrode in positive potential or electrode to bacteria in a negative potential). As a result, increased 3-hydroxypropionic acid production was identified in a positive potential (+ 0.7 V) with a simultaneous decrease in the NADH/NAD+ ratio, whereas enhanced 1,3-propanediol production with a relatively high NADH/NAD+ ratio was presented in the negative potential (–0.7 V). This study suggests an electrode-based metabolic regulation for the heterologously expressed glycerol pathway in E. coli, a weak electroactive but industrially feasible host bacteria.
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TREM2 plays a critical role in the alleviation of Alzheimer's disease by promoting Aβ phagocytosis by microglia, but the detailed molecular mechanism underlying TREM2-induced direct phagocytic ...activity of Aβ remains to be revealed. We found that learning and memory functions were improved in aged TREM2 TG mice, with the opposite effects in KO mice. The amount of phagocytosed Aβ was significantly reduced in the primary microglia of KO mice. CD36 expression in primary microglia was greater in TG than in WT mice but was substantially decreased in KO mice. The expression of C/EBPα, an upstream transcriptional activator of CD36, was also elevated in primary microglia of TG mice but decreased in KO mice. The transcription of CD36 was markedly increased by TREM2 overexpression, and this effect was suppressed by a mutation of the C/EBPα binding site on the CD36 promoter. The TREM2-induced expression of CD36 and C/EBPα was inhibited by treatment with PI3K/AKT signaling blockers, and phosphorylation of AKT was elevated in TREM2-overexpressing BV2 cells. The present study provides evidence that TREM2 is required for preventing loss of memory and learning in Alzheimer's disease by regulating C/EBPα-dependent CD36 expression and the consequent Aβ phagocytosis.
Optimal sensor placement is used to establish the optimal sensor quantity and layout. In this study, the minimum quantity and locations of measurement sensors were assumed to satisfy the constraint ...conditions of the optimal sensor placement. A set of strain data in a truss structure was expanded to another set of displacements corresponding to the entire degrees of freedom from the relationship between the strain and displacement. It indicates to reduce the number of sensors because the strain depends on the displacements in a finite element model. The damaged truss element was traced using the expanded data that satisfied the prescribed constraints. The proposed optimal sensor placement method has a merit to explicitly determine the optimal sensor locations without any numerical scheme and statistical methods. The method was applied to the damage detection of a single-damaged truss structure. It was shown that the optimal sensor placement method depended on the sensor layout irrespective of the same quantity of sensors. In addition, a numerical example was used to compare sensitivities to damage detection based on the sensor placement and the existence of external noise contained in the measurement data.
BACKGROUND:Pediatric cardiac patients are at risk for perioperative respiratory insufficiency. The objective of this study was to assess the utility of perioperative lung ultrasound examination in ...pediatric cardiac surgery.
METHODS:In this randomized, controlled trial, children (5 yr old or younger) undergoing cardiac surgery were allocated into a control (n = 61) or intervention (n = 61) group. The control group received only lung ultrasound examinations at the end of surgery and 6 to 12 h after surgery. The intervention group received lung ultrasound examinations and an ultrasound-guided recruitment maneuver depending on ultrasound findings after inducing anesthesia, at the end of surgery, and 6 to 12 h after surgery. Primary outcomes were incidences of intra- and postoperative desaturation, and postoperative pulmonary complications. Multiple comparisons were corrected (P ≤ 0.017) in the primary outcome analysis.
RESULTS:Of the 120 children included in the analysis, postoperative desaturation (64% vs. 27%; P < 0.001; odds ratio OR, 0.210; 95% CI, 0.097 to 0.456) occurred more in the control group. The incidences of intraoperative desaturation (36% vs. 19%; P = 0.033; OR, 0.406; 95% CI, 0.176 to 0.939) and postoperative pulmonary complications (12% vs. 3%; P = 0.093; OR, 0.271; 95% CI, 0.054 to 1.361) were similar between the groups. Lung ultrasound scores were better in the intervention group than in the control group. Duration of mechanical ventilation was longer in the control group than in the intervention group (38 ± 43 vs. 26 ± 25 h; 95% CI of mean difference, 0 to 25; P = 0.048).
CONCLUSIONS:Perioperative lung ultrasound examination followed by ultrasound-guided recruitment maneuver helped decrease postoperative desaturation events and shorten the duration of mechanical ventilation in pediatric cardiac patients.
VISUAL ABSTRACT:An online visual overview is available for this article at http://links.lww.com/ALN/B682.
In this paper, characteristics of PV (photovoltaic) modules under partial shading or with a damaged bypass diode in the junction box were evaluated by comparing a theoretical model and empirical ...data. For the electrical analysis of the current-voltage (I-V) curve of each module, a PV module with one diode cell model was proposed, and the model closely matched the empirical results. The damaged bypass diode was replaced with an element of resistance in the simulation model. The calculation shows that the open circuit voltage of the PV module with a damaged bypass diode was slightly higher than that of a PV module under shading conditions while the PV system was operating. The I-V curve of each module obtained with the solar simulator was similar to the results of the simulation. From the results of field testing each PV module, when the PV system was operating in connection with the power grid, the internal temperature of the junction box connected to the shaded PV module was 5 °C higher than that of the PV module with the damaged bypass diode. Furthermore when the PV system was not operating, the internal temperature of the junction box in the PV module with the damaged bypass diode was extremely high. This condition caused a short-circuit and the surface temperature of the damaged bypass diode reached 219 °C. In this paper, we theoretically and empirically analyzed the characteristics of a shaded PV module and a module with a damaged bypass diode.
•It proposed the mathematical models of PV modules under shading and with damaged bypass diode.•Electric and thermal characteristics of PV modules under shading and with damaged bypass diode were discussed.•It is possible to distinguish shading or bypass diode failure in PV modules using the thermal characteristics.
Polyurea coating helps improve the ductility and toughness of structural members. A fiber-reinforced polyurea (FRPU) composite provides high load-carrying capacity and is applied by simply spraying ...it onto the member surface. Unlike existing reinforcement approaches, the FRPU coating method can prevent the ductility of concrete beams from deteriorating and the concrete surface from debonding. In this study, 20 concrete beams were tested with respect to their load-carrying capacity and flexural ductility using polyurea or FRPU reinforcement. The test variables included the type of reinforcing fibers, coating thickness, and weight-to-content ratio of the fibers in the FRPU. Moreover, the load-carrying capacity and mechanical behavior of all specimens were compared according to the content of the steel fibers, milled glass fibers, or carbon nanotubes (CNTs). Specimens reinforced using polyurea or FRPU were confirmed to retain the load-carrying capacity and flexural ductility to a certain degree after concrete failure at the tension face of the midspan section. The concrete beams ultimately failed through the fracture of polyurea or FRPU without debonding. Experiments were conducted to illustrate the strengthening effect by FRPU and determine its superiority.
The dynamic properties of structural and mechanical systems are commonly predicted using frequency response functions (FRFs), which represent the relationship between input forces and the ...corresponding responses in the frequency domain. Analytically calculated responses seldom coincide with actual responses because of modeling and construction errors, performance deterioration in service, etc. The inconsistency requires the correction of the FRF matrix for subsequent analysis, performance evaluation, etc. Obtaining the complete FRF matrix corresponding to all the degrees of freedom at measurement is not practical. This paper derives the mathematical form to expand the incomplete FRF matrix at measurement using the least-squares approach constrained by measured FRFs and correct the FRF matrix at the intact state. Additionally, this paper provides two analytical methods to predict unknown input dynamic excitations using the expanded FRF matrix and direct approaches. Numerical applications elucidate the validity and drawbacks of the proposed methods.
In photovoltaic module manufacturing processes, it is essential to achieve high production reliability of modules based on the given cells with scattered characteristics. This study aims to ...investigate the optimal cell sorting method to minimize the deviation of module power via simulation analysis. We consider the given solar cells to have different electrical characteristics with Gaussian distributions and ideal interconnections. We examine the resultant power distributions of modules for various cell sorting methods based on multiple cell parameters such as maximum power current, maximum power voltage, and maximum power of the cells. Our simulation shows that the average power maximum of the modules in different sorting methods has a marginal difference, and the mismatch loss by different cell characteristics is not a key factor to reduce the module reliability, but the standard deviation of the maximum powers of modules can be largely reduced by one order of magnitude if the cells are sorted out based on the reference of the average power maximum of the participated cells. Our study will provide useful guidance for cost-efficient and reliable photovoltaic modules in the manufacturing process.
Triggering receptor expressed on myeloid cells 2 (TREM2) is known to be involved in the anti-inflammatory response and osteoclast development. However, the role of TREM2 in adipogenesis or obesity ...has not yet been defined. The effect of TREM2 on adipogenesis and obesity was investigated in TREM2 transgenic (TG) mice on a high-fat diet (HFD). To block TREM2 signaling, a neutralizing fusion protein specific for TREM2 (TREM2-Ig) was used. TG mice were much more obese than wild-type mice after feeding with an HFD, independent of the quantity of food intake. These HFD-fed TG mice manifested adipocyte hypertrophy, glucose and insulin resistance, and hepatic steatosis. The expression of adipogenic regulator genes, such as peroxisome proliferator-activated receptor γ and CCAAT/enhancer-binding protein α, was markedly increased in HFD-fed TG mice. Additionally, HFD-fed TG mice exhibited decreased Wnt10b expression and increased GSK-3β (glycogen synthase kinase-3β)-mediated β-catenin phosphorylation. In contrast, the blockade of TREM2 signaling using TREM2-Ig resulted in the inhibition of adipocyte differentiation in vitro and a reduction in body weight in vivo by downregulating the expression of adipogenic regulators. Our data demonstrate that TREM2 promotes adipogenesis and diet-induced obesity by upregulating adipogenic regulators in conjunction with inhibiting the Wnt10b/β-catenin signaling pathway.
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