In this paper, we investigate the cycle-based sizing optimization for diesel-engine two-cell selective catalytic reduction (SCR) systems. In modeling the SCR system, it is generally assumed that the ...states inside the catalyst can are homogeneous to simplify the modeling work. However, the actual states are not homogeneous, and the modeling error becomes large if the catalyst length is long. To reduce the modeling error, the states are assumed piecewise homogeneous, i.e., the catalyst is sliced into multicells and the states for each cell are assumed homogeneous. In this paper, we focus on the two-cell SCR systems where the two cells are connected in series and where the chemical reaction rates are assumed identical for the two cells. Considering the main chemical reactions and assuming that each cell is a continuous stirred tank reactor, a nonlinear system model with six states is obtained. To simultaneously reduce the tailpipe NO ∞ and ammonia slip, it is quite interesting to study the optimal control of the urea dosing such that the NO ∞ emissions can be maximally converted and where the ammonia slip is constrained. A dynamic programming (DP) algorithm that has a tolerable computational load is proposed. Since the whole catalyst is sliced into two cells, the next motivation is how to divide the catalyst such that the NO ∞ conversion efficiency can be maximized while meeting the tailpipe ammonia constraint. The best sizing ratio of the SCR system in our application for the US06 test cycle is found to be 60%-40%.
Oxymatrine (OXY) has antioxidative and antiinflammatory activities. In the present work, we investigate the effects of OXY on gastric ulcer models and elucidate the underlying mechanisms of action. ...Ethanol, indometacin, and restraint water immersion stress‐induced ulcerated models were used. The ulcer area was measured, and samples of gastric tissue were taken for pathological, histochemical, and biochemical analyses. OXY effectively reduced the area of gastric ulcers and improved the pathological changes of ulcerated tissue. OXY enhanced expression of Bcl‐2, reduced Bax protein expression, and inhibited alcohol‐induced apoptotic death in both ulcerated tissue and human gastric epithelial cells. OXY increased the prostaglandin E2 level and improved oxidative stress (malondialdehyde, superoxide dismutase, catalase, and nitric oxide) and inflammatory parameters (TNF‐a, IL‐6, and IL‐1) of ulcer tissue. OXY prevented an inflammatory response via decreasing expression of p38, p‐ERK, p‐JNK, and inhibiting NF‐κB p65 translocation from the cytoplasm to the nucleus. Our results reveal that OXY has remarkable protective effects on gastric ulcers. The action of OXY may be mediated via suppression of gastric inflammatory reactions, oxidative stress, and pro‐apoptotic actions, which were the results of blockades of MAPKs and NF‐κB signaling pathways. Our results provide evidence for the beneficial effects of OXY for treating peptic ulcers.
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The 48-V diesel mild-hybrid electric vehicle equipped with an electrically heated catalyst is a cost-effective solution to reduce tailpipe emissions, while its supervisory control design is more ...challenging, due to cross-coupled energy and thermal subsystems. This article presents a distributed control design for the energy and thermal management system, aiming to optimize fuel economy and reduce catalyst warm-up time, by cooperation between electrical heating and engine load upshift. A control-oriented model of HEV and catalyst is developed, which captures the dynamics of the battery state of charge and catalyst temperature. The energy and thermal management problem is cast as a hybrid optimal control problem, to minimize entire trip fuel consumption under different switching (warm-up) times. An off-line solution method is designed to exploit the tradeoff between fuel and warm-up time based upon hybrid minimum principle and a nested shooting algorithm. For online implementation, a distributed supervisory control is proposed, which covers both cold-start and normal operations, and is compatible with the equivalent consumption minimization strategy. Both off-line and online methods are validated in simulation, using two driving cycles and five warm-up speeds.
Electrified propulsion systems have now become an increasingly popular option for automotive companies to meet the more stringent emissions standards. A well-designed battery state estimation (BSE) ...system, which includes state-of-charge and state-of-health estimation, is one of the most important aspects of a successful electrified propulsion system design. Among different methods, model-based state estimation has proven to be very successful in their accuracy and implementability. A relatively newer approach to model-based BSE is to identify the battery model parameters (typically a low-order control-oriented model) in real time. This allows the battery model parameter to adjust to changing characteristics of the battery, and thus further improving the robustness of the design. However, standard identification algorithms used have very limited capability in performing this identification successfully due to the frequency response characteristics of the battery. In this brief, we describe a two time-scaled battery model parameter identification method, where the slower and faster battery dynamics are identified separately. Compared with standard approach to real-time battery model identification, where no such separation is made, this method can generate a model whose frequency response is much closer to that of the actual battery. Furthermore, this method uses the standard least squares regression method, which can be easily implemented in real time in the form of recursive least squares. Using this identification method, we show how battery SoC can be estimated. Laboratory battery cell data is used to illustrate the difference between this method and the more standard approach. Then, battery pack collected from a test vehicle is used to demonstrate the SoC estimation capability.
It is revealed that Xiaoyaosan could reduce glutamate level in the hippocampus of depressed rats, whose metabolism leads to the pathophysiology of depression. However, the underlying mechanism ...remains unclear. This study aims to explore the effect of Xiaoyaosan on glutamate metabolism, and how to regulate the excitatory injury caused by glutamate.
Rats were induced by chronic unpredictable mild stress, then divided into control, vehicle (distilled water), Xiaoyaosan, fluoxetine, vehicle (DMSO), Xiaoyaosan + Ly294002 and Ly294002 groups. Ly294002 was microinjected into the lateral ventricular catheterization at 5 mM. Xiaoyaosan (2.224 g/kg) and fluoxetine (2.0 mg/kg) were orally administered for three weeks. The open field test (OFT), forced swimming test (FST), and sucrose preference test (SPT) were used to assess depressive behavior. The glutamate and corticosterone (CORT) levels were detected by ELISA. Western blot, immunochemistry or immunofluorescence were used to detect the expressions of NR2B, MAP2, PI3K and P-AKT/Akt in the hippocampal CA1 region. The mRNA level of MAP2, NR2B and PI3K were detected by RT-qPCR.
Compared to the rats in control group, body weight and food intake of CUMS rats was decreased. CUMS rats also showed depression-like behavior as well as down regulate the NR2B and PI3K/Akt signaling pathway. Xiaoyaosan treatments could increase food intake and body weight as well as improved time spent in the central area, total distance traveled in the OFT. Xiaoyaosan could also decrease the immobility time as well as increase the sucrose preference in SPT. Moreover, xiaoyaosan decreased the level of glutamate in the hippocampal CA1 region and serum CORT in CUMS rats. Furthermore, xiaoyaosan improved the expression of MAP2 as well as increased the expression of NR2B, PI3K and the P-AKT/AKT ratio in the hippocampal CA1 region in the CUMS rats.
Xiaoyaosan treatment can exert the antidepressant effect by rescuing hippocampal neurons loss induced by the glutamate-mediated excitotoxicity in CUMS rats. The underlying pathway maybe through NR2B and PI3K/Akt signaling pathways. These results may suggest the potential of Xiaoyaosan in preventing the development of depression.
Aim
Platinum‐based chemotherapy is the standard treatment for ovarian cancer. However, tumor cells' resistance to platinum drugs often occurs. This paper provides a review of Forkhead box O (FOXO) ...protein's role in platinum resistance of ovarian cancer which hopefully may provide some further guidance for the treatment of platinum‐resistant ovarian cancer.
Methods
We reviewed a 128 published papers from authoritative and professional journals on FOXO and platinum‐resistant ovarian cancer, and adopts qualitative analyses and interpretation based on the literature.
Results
Ovarian cancer often has abnormal activation of cellular pathways, the most important of which is the PI3K/AKT pathway. FOXOs act as crucial downstream factor of the PI3K/Akt pathway and are negatively regulated by it. DNA damage response and apoptosis including the relationship between FOXOs and ATM‐Chk2‐p53 are essential for platinum resistance of ovarian cancer. Through gene expression analysis in platinum‐resistant ovarian cancer cell model, it was found that FoxO‐1 is decreased in platinum‐resistant ovarian cancer, so studying the role of FOXO in the pathway on platinum‐induced apoptosis may further guide the treatment of platinum‐resistant ovarian cancer.
Conclusions
There are many drug resistance mechanisms in ovarian cancer, wherein the decrease in cancer cells apoptosis is one of the important causes. Constituted by a series of transcription factors evolving conservatively and mainly working in inhibiting cancer, FOXO proteins play various roles in cells' antitumor response. More and more evidence suggests that we need to re‐understand the role that FOXOs have played in cancer development and treatment.
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There is significant controversy regarding the influence of video laryngoscopy on the intubation outcomes in emergency and critical patients. This systematic review and meta-analysis was designed to ...determine whether video laryngoscopy could improve the intubation outcomes in emergency and critical patients.
We searched the Cochrane Central Register of Controlled Trials, PubMed, Embase, and Scopus databases from database inception until 15 February 2017. Only randomized controlled trials comparing video and direct laryngoscopy for tracheal intubation in emergency department, intensive care unit, and prehospital settings were selected. The primary outcome was the first-attempt success rate. Review Manager 5.3 software was used to perform the pooled analysis and assess the risk of bias for each eligible study. The GRADE (Grading of Recommendations Assessment, Development and Evaluation) system was used to assess the quality of evidence for all outcomes.
Twelve studies (2583 patients) were included in the review for data extraction. Pooled analysis did not show an improved first-attempt success rate using video laryngoscopy (relative risk RR, 0.93; P = 0.28; low-quality evidence). There was significant heterogeneity among studies (I
= 91%). Subgroup analyses showed that, in the prehospital setting, video laryngoscopy decreased the first-attempt success rate (RR, 0.57; P < 0.01; high-quality evidence) and overall success rate (RR, 0.58; 95% CI, 0.48-0.69; moderate-quality evidence) by experienced operators, whereas in the in-hospital setting, no significant difference between two devices was identified for the first-attempt success rate (RR, 1.06; P = 0.14; moderate-quality evidence), regardless of the experience of the operators or the types of video laryngoscopes used (P > 0.05), although a slightly higher overall success rate was shown (RR, 1.11; P = 0.03; moderate-quality evidence). There were no differences between devices for other outcomes (P > 0.05), except for a lower rate of esophageal intubation (P = 0.01) and a higher rate of Cormack and Lehane grade 1 (P < 0.01) when using video laryngoscopy.
On the basis of the results of this study, we conclude that, compared with direct laryngoscopy, video laryngoscopy does not improve intubation outcomes in emergency and critical patients. Prehospital intubation is even worsened by use of video laryngoscopy when performed by experienced operators.
Blue photoluminescene (PL) from chemically derived graphene oxide has been observed. The PL is attributed to radiative recombination of electron–hole pairs in isolated “molecular” sp2 domains, which ...are present within the carbon–oxygen sp3 matrix in chemically derived graphene oxide. The PL intensity is correlated to the evolution of sp2 domains during reduction.
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