Stable dynamic pricing scheme independent of lane-choice models for high-occupancy-toll lanes

A stable dynamic pricing scheme is essential to guarantee the desired performance of high-occupancy-toll (HOT) lanes, where single-occupancy vehicles (SOVs) can pay a price to use the HOT lanes. But existing methods apply to either only one type of lane-choice models with unknown parameters or different types of lane-choice models but with known parameters. In this study we present a new dynamic pricing scheme that is stable and applies to different types of lane-choice models with unknown parameters. There are two operational objectives for operating HOT lanes: (i) to maintain the free-flow condition to guarantee the travel time reliability; and (ii) to maximize the HOT lanes’ throughput to minimize the system's total delay. The traffic dynamics on both HOT and general purpose (GP) lanes are described by point queue models, where the queueing times are determined by the demands and capacities. We consider three types of lane-choice models: the multinomial logit model when SOVs share the same value of time, the vehicle-based user equilibrium model when SOVs’ values of time are heterogeneous and follow a distribution, and a general lane-choice model. We demonstrate that the second objective is approximately equivalent to the social welfare optimization principle for the logit model. Observing that the dynamic price and the excess queueing time on the GP lanes are linearly correlated in all the lane-choice models, we propose a feedback control method to determine the dynamic prices based on two integral controllers. We further present a method to estimate the parameters of a lane-choice model once its type is known. Analytically we prove that the equilibrium state of the closed-loop system with constant demand patterns is ideal, since the two objectives are achieved in it, and that it is asymptotically stable. With numerical examples we verify the effectiveness of the solution method

A Control Theoretic Approach to Simultaneously Estimate Average Value of Time and Determine Dynamic Price for High-Occupancy Toll Lanes

The dynamic pricing problem of a freeway corridor with high-occupancy toll (HOT) lanes was formulated and solved based on a point queue abstraction of the traffic system [1]. However, existing pricing strategies cannot guarantee that the closed-loop system converges to the optimal state, in which the HOT lanes' capacity is fully utilized but there is no queue on the HOT lanes, and a well-behaved estimation and control method is quite challenging and still elusive. This paper attempts to fill the gap by making three fundamental contributions: (i) to present a simpler formulation of the point queue model based on the new concept of residual capacity, (ii) to propose a simple feedback control theoretic approach to estimate the average value of time and calculate the dynamic price, and (iii) to analytically and numerically prove that the closed-loop system is stable and guaranteed to converge to the optimal state, in either Gaussian or exponential manners

Correlation between change in body mass and mortality during hospitalization in intensive care unit: a retrospective cohort study

Objective To explore the effect of change in body mass on mortality during hospitalization in intensive care unit (ICU). Methods A multicenter and retrospective cohort study was conducted on patients who were firstly hospitalized in ICU and whose length of ICU stay were over 24 h, with data extracted from the eICU Collaborative Research Database. Univariate and multivariate logistic regression models were used to explore the relationship between body mass change and mortality in ICU patients. Interaction analysis was performed between body mass change and related covariates. Based on the results of interaction analysis and clinical practice, the association between body mass change and mortality was analyzed in subgroups stratified by age, Acute Physiology and Chronic Health Evaluation (APACHE) Ⅳ score, length of ICU stay and baseline BMI at ICU admission. Results A total of 34 311 ICU patients were included, among which 55.1% were male, the white race accounted for 82.4% and 51.3% were ≥65 years old. Compared with those with decreased body mass, patients with increased body mass had higher rates of renal failure (1 938 cases, 11.1%), liver failure (106 cases, 0.6%), sepsis (2 442 cases, 14.0%), longer ICU stay, longer hospital stay and higher APACHEⅣ scores. The multivariate logistic regression model showed the in-hospital and ICU mortality in patients with body mass gain were 1.25 times(95%CI: 1.16~1.36, P < 0.001) and 1.36 times (95%CI: 1.22~1.50, P < 0.001) higher than those with body mass decreased respectively. This difference is more significant in patients with higher APACHEⅣ score and the longer ICU stay. The different age subgroup or different baseline BMI levels exerted no effect on the results mentioned. Conclusion The change in body mass is the independent risk factor of the in-hospital and ICU motality

The quality control and hypoglycemic effect of Cinnamomi Cortex aqueous extract

ABSTRACT: Cinnamomi Cortex was a material as medicinal and edible resources and it has been demonstrated that Cinnamomi Cortex aqueous extract (CCAE) possess hypoglycemic effect, but there were no active compounds identified as quality standard of CCAE to be used in the investigate of hypoglycemic activity. Hence, in this study, the quality standard and the hypoglycemic effect of CCAE were investigated. Cinnamaldehyde and coumarin as the quality control in CCAE were analyzed by high performance liquid chromatography (HPLC) method. The results showed that the average yield of extraction was 10.06%. The concentration of coumarin was linear with peak area ranging from 0.02–1.00 μg/mL (r = 0.999 6, n = 6) and that of cinnamaldehyde also demonstrated a good linear relationship with peak area in the range of 1.05–52.50 μg/mL (r = 0.999 7, n = 6). The average recovery rate of coumarin and cinnamaldehyde was 99.42% and 100.11%, respectively. The investigation of hypoglycemic effect revealed that CCAE could improve weight loss, lower liver and pancreas indices, improve organ damage caused by diabetes, and lower fasting blood glucose, glycosylated serum protein (GSP) and total cholesterol (TC) levels. The results showed that CCAE can reduce fasting blood glucose and blood lipid levels in diabetic mice

Identification of Hub Genes as Biomarkers Correlated with the Proliferation and Prognosis in Lung Cancer: A Weighted Gene Co-Expression Network Analysis

Lung cancer is one of the most malignant tumors in the world. Early diagnosis and treatment of lung cancer are vitally important to reduce the mortality of lung cancer patients. In the present study, we attempt to identify the candidate biomarkers for lung cancer by weighted gene co-expression network analysis (WGCNA). Gene expression profile of GSE30219 was downloaded from the gene expression omnibus (GEO) database. The differentially expressed genes (DEGs) were analyzed by the limma package, and the co-expression modules of genes were built by WGCNA. UALCAN was used to analyze the relative expression of normal group and tumor subgroups based on tumor individual cancer stages. Survival analysis for the hub genes was performed by Kaplan–Meier plotter analysis with the TCGA database. A total of 2176 genes (745 upregulated and 1431 downregulated genes) were obtained from the GSE30219 database. Seven gene co-expression modules were conducted by WGCNA and the blue module might be inferred as the most crucial module in the pathogenesis of lung cancer. In the pathway enrichment analysis of KEGG, the candidate genes were enriched in the “DNA replication,” “Cell cycle,” and “P53 signaling pathway” pathways. Among these, the cell cycle pathway was the most significant pathway in the blue module with four hub genes CCNB1, CCNE2, MCM7, and PCNA which were selected in our study. Kaplan–Meier plotter analysis indicated that the high expressions of four hub genes were correlated with a worse overall survival (OS) and advanced tumors. qRT-PCR showed that mRNA expression levels of MCM7 (p=0.038) and CCNE2 (0.003) were significantly higher in patients with the TNM stage. In summary, the high expression of the MCM7 and CCNE2 were significantly related with advanced tumors and worse OS in lung cancer. Thus, the MCM7 and CCNE2 genes can be good indicators for cellular proliferation and prognosis in lung cancer

Downregulation of PTPRK Promotes Cell Proliferation and Metastasis of NSCLC by Enhancing STAT3 Activation

Objective. The receptor-type tyrosine-protein phosphatase κ (PTPRK) is a candidate tumor suppressor involved in the tumorigenesis of various organs. However, its expression and biological roles in non-small-cell lung cancer (NSCLC) have not yet been investigated. Methods. PTPRK expression in NSCLC tissues and cell lines was examined using real-time PCR and western blotting. In addition, the effects of PTPRK on cell migration, invasion, and proliferation were evaluated in vitro. Furthermore, we explored whether the downregulation of PTPRK led to STAT3 activation in NSCLC cell lines by western blotting. The expression of phospho-STAT3Tyr705 in primary human NSCLC tissues was evaluated by immunohistochemistry. Results. The results showed that PTPRK expression was frequently reduced in NSCLC tissues with lymph node metastasis and cell lines. The inhibition of PTPRK expression resulted in increased proliferation, invasion, and migration of NSCLC cells in vitro. Additionally, after silencing of PTPRK, phospho-STAT3Tyr705 was significantly increased in NSCLC cells. Moreover, the phospho-STAT3Tyr705 levels of NSCLC tissues were positively correlated with lymph node metastasis and significantly inversely correlated with the expression of PTPRK (p<0.05). Conclusions. These results suggested that PTPRK functions as a novel tumor suppressor in NSCLC, and its suppressive ability may be involved in STAT3 activation

A compact aqueous K-ion Micro-battery by a Self-shrinkage assembly strategy

Micro-batteries are promising power sources to drive miniaturized or portable electronic devices due to their higher energy density than micro-supercapacitors. Current micro-batteries still suffer from relatively large footprint and unsatisfactory areal electrochemical performance caused by loose electrode structure. Here, we develop a compact aqueous K-ion micro-battery through the self-shrinking of reduced graphene oxide hydrogel to realize small footprint and high areal capacity at the same time. With a volume of as small as 0.00381 cm(-3), this micro-battery delivers the highest areal capacity (5.1 mAh cm(-2)) and energy density (4.78 mWh cm(-2)) among all reported micro-batteries. Meanwhile, this micro-battery can be prepared into different shapes and attached onto a range of animals (ants, crabs and butterflies, etc.) for wide applications

Relationship of Admission Serum Anion Gap and Prognosis of Critically Ill Patients: A Large Multicenter Cohort Study

Background. There were controversies over the relationship between Anion gap (AG) and mortality in critically ill patients. Therefore, a large multicenter cohort study was conducted to evaluate the association of AG and mortality in large-scale intensive care units (ICUs) patients. Methods. This retrospective cohort study included adult ICU patients enrolled from eICU Collaborative Research Database. According to initial serum AG upon ICU admission, patients were divided into three groups: AG16 mmol/L. Logistic regression models were built to investigate the association between serum AG and ICU and hospital mortalities. Serum AG was added into Acute Physiology and Chronic Health Evaluation (APACHE) IV score and the model discrimination was assessed by the area under the curve (AUC) of receiver operating characteristic curves. The relationship between serum AG and mortalities in patients with different acid-base status and serum lactate were also evaluated. An external validation was performed with the Critical care database comprising patients with infection at Zigong Fourth People’s Hospital. Results. A total of 8520 patients entered the final cohort. There are 42 patients with serum AG16 mmol/L. Serum AG>16 mmol/L is related with increased ICU mortality (odds ratio [OR], 1.530; 95% confidence interval [CI], 1.305–1.794) and hospital mortality (OR, 1.618; 95% CI, 1.415–1.849), compared with 8≤AG≤16 mmol/L. Adding Serum AG to APACHE IV score could statistically improve the prediction of ICU (0.770 [0.761–0.779] to 0.774 [0.765–0.783], P=0.001) and hospital mortalities (0.756 [0.747–0.765] to 0.761 [0.751–0.770], P=0.012). The associations between serum AG and mortalities remain robust in patients with different acid-base statuses and serum lactate. The findings are validated in the external cohort. Conclusions. Initial serum AG>16 mmol/L after ICU admission is associated with increased mortality in critically ill patients

Ultrafast Synthesis of Metal-Layered Hydroxides in a Dozen Seconds for High-Performance Aqueous Zn (Micro-) Battery

Abstract Efficient synthesis of transition metal hydroxides on conductive substrate is essential for enhancing their merits in industrialization of energy storage field. However, most of the synthetic routes at present mainly rely on traditional bottom-up method, which involves tedious steps, time-consuming treatments, or additional alkaline media, and is unfavorable for high-efficiency production. Herein, we present a facile, ultrafast and general avenue to synthesize transition metal hydroxides on carbon substrate within 13 s by Joule-heating method. With high reaction kinetics caused by the instantaneous high temperature, seven kinds of transition metal-layered hydroxides (TM-LDHs) are formed on carbon cloth. Therein, the fastest synthesis rate reaches ~ 0.46 cm2 s−1. Density functional theory calculations further demonstrate the nucleation energy barriers and potential mechanism for the formation of metal-based hydroxides on carbon substrates. This efficient approach avoids the use of extra agents, multiple steps, and long production time and endows the LDHs@carbon cloth with outstanding flexibility and machinability, showing practical advantages in both common and micro-zinc ion-based energy storage devices. To prove its utility, as a cathode in rechargeable aqueous alkaline Zn (micro-) battery, the NiCo LDH@carbon cloth exhibits a high energy density, superior to most transition metal LDH materials reported so far