Cross-layer design for wireless sensor relay networks

In recent years, the idea of wireless sensor networks has gathered a great deal of attention. A distributed wireless sensor network may have hundreds of small sensor nodes. Each individual sensor contains both processing and communication elements and is designed in some degree to monitor the environmental events specified by the end user of the network. Information about the environment is gathered by sensors and delivered to a remote collector. This research conducts an investigation with respect to the energy efficiency and the cross-layer design in wireless sensor networks. Motivated by the multipath utilization and transmit diversity capability of space-time block codes (STBC), a new energy efficient cooperative routing algorithm using the STBC is proposed. Furthermore, the steady state performance of the network is analyzed via a Markov chain model. The proposed approach in this dissertation can significantly reduce the energy consumption and improve the power efficiency. This work also studies the application of differential STBC for wireless multi-hop sensor networks over fading channels. Using differential STBC, multiple sensors are selected acting as parallel relay nodes to receive and relay collected data. The proposed technique offers low complexity, since it does not need to track or estimate the time-varying channel coefficients. Analysis and simulation results show that the new approach can improve the system performance. This dissertation models the cooperative relay method for sensor networks using a Markov chain and an M/G/1 queuing system. The analytical and simulation results indicate system improvements in terms of throughput and end-to-end delay. Moreover, the impact of network resource constraints on the performance of multi-hop sensor networks with cooperative relay is also investigated. The system performance under assumptions of infinite buffer or finite buffer sizes is studied, the go through delay and the packet drop probability are improved compared to traditional single relay method. Moreover, a packet collision model for crucial nodes in wireless sensor networks is introduced. Using such a model, a space and network diversity combining (SNDC) method is designed to separate the collision at the collector. The network performance in terms of throughput, delay, energy consumption and efficiency are analyzed and evaluated

Effect of dexmedetomidine hydrochloride combination with conventional anesthesia on serum cortisol, inflammatory factors and cellular immunity during surgery on children with congenital anus atresia

Purpose: To study the effect of a combination of dexmedetomidine hydrochloride (DXM) and conventional anesthesia on surgical anesthesia in pediatric congenital anoplasty.Methods: Fifty children with congenital anus atresia were divided into control and study group. Both groups underwent anal angioplasty or colostomy, with the control group under conventional anesthesia, while the study group received both conventional anesthesia and DXM. Heart beat rate, arterial blood pressure, changes in oxygen saturation were recorded. Blood loss were noted. Venous blood was collected at various time points for assay of serum cortisol, IL-6, and T-lymphocyte subsets.Results: The arterial pressure and heart beat of the study group at T1 and T2 were significantly lower than those of the control group (p ˂ 0.05). Blood loss was significantly lower in the study group than in the control group (p ˂ 0.05). Serum cortisol and IL-6 levels at T1, T2 and T3 in both groups significantly increased, compared with T0, with levels in the study group significantly lower than those in the control group (p < 0.05). Values of CD3 +, CD4 + and CD4 +/CD8 + in both groups significantly decreased at T2, when compared with corresponding values at T0, while the levels in the study group were significantly lower than those in the control group (p < 0.05).Conclusion: Dexmedetomidine hydrochloride combined with conventional anesthesia is more effective than conventional anesthesia during surgery on congenital anal atresia.Keywords: Dexmedetomidine hydrochloride, Congenital anal atresia, Cortisol, IL-6, T-lymphocyte subset

Fluctuation-Induced Transitions in Anisotropic Two-Dimensional Turbulence

Two-dimensional (2D) turbulence features an inverse energy cascade producing large-scale flow structures such as hurricane-like large-scale vortices (LSVs) and jets. We study the dynamics of such structures by direct numerical simulations (DNS) of stochastically forced, viscously damped 2D turbulence within a periodic rectangular domain $[0,L_x]\times[0,L_y]$. Stable LSVs form in the system when the aspect ratio $\delta = L_x/L_y \approx 1$, while jets predominate at $\delta\gtrsim 1.1$. At intermediate values of $\delta$, both structures are metastable, and noise-induced transitions occur between them. Based on large-scale energy balance, we derive and verify predictions for the parameter dependence of the total kinetic energy and the flow polarity. We collect detailed statistics on the lifetimes of LSVs and jets from long-time simulations, consistent with a memoryless process. Our DNS results support both an exponential and an algebraic dependence of the mean lifetime on $\delta$. We show that the mean lifetime depends strongly on the Reynolds number $Re$. As $Re$ increases, the energy gap between LSV (lower energy) and jet states (higher energy) grows, leading to increasing lifetimes following power laws in $Re$. Similarly, as the forcing scale decreases, transitions become less frequent. We study the transitions in terms of kinetic energy, flow polarity, and 2D phase-space diagrams, revealing that the transitions occur in two stages: an initial, efficient redistribution of kinetic energy by nonlinear triadic interactions facilitates a rapid transition from LSVs to jets and vice versa. In the second stage, the kinetic energy of the newly formed structure slowly adjusts to its associated equilibrium value on a longer, viscous timescale, leading to hysteresis. Our findings shed new light on the dynamics of coherent large-scale structures in anisotropic turbulence

Study on the settlement law of tunnel in diatomite stratum based on Strain Softening model

Nowadays, there is no precedent for building a high-speed railway in diatomite area. Due to the complex structure and poor mechanical properties of diatomite as well as the lack of relevant engineering experience, more attention has been paid to the proper constitutive model of the tunnel in diatomite layer using the numerical calculation method, while the traditional Elastoplastic calculation model is the most used yet. Therefore, relying on the Feifengshan tunnel, through FLAC3D software as well as the on-site monitoring, the analysis of the settlement law about tunnelling in diatomite stratum is carried out based on different constitutive models. The research results show that diatomite has obvious strain-softening characteristics. The calculated surface settlement and vault settlement based on the Strain Softening model was greater than that based on the Mohr Coulomb model. When compared with the on-site monitoring data, it was found that the Strain Softening model would more accurately show the settlement law of the tunnel in diatomite and has better applicability in the diatomite area. The above-mentioned research results may provide some references for the construction and design of tunnels in similar strata in the future

A cuproptosis random forest cox score model-based evaluation of prognosis, mutation characterization, immune infiltration, and drug sensitivity in hepatocellular carcinoma

BackgroundHepatocellular carcinoma is the third most deadly malignant tumor in the world with a poor prognosis. Although immunotherapy represents a promising therapeutic approach for HCC, the overall response rate of HCC patients to immunotherapy is less than 30%. Therefore, it is of great significance to explore prognostic factors and investigate the associated tumor immune microenvironment features.MethodsBy analyzing RNA-seq data of the TCGA-LIHC cohort, the set of cuproptosis related genes was extracted via correlation analysis as a generalization feature. Then, a random forest cox prognostic model was constructed and the cuproptosis random forest cox score was built by random forest feature filtering and univariate multivariate cox regression analysis. Subsequently, the prognosis prediction of CRFCS was evaluated via analyzing data of independent cohorts from GEO and ICGC by using KM and ROC methods. Moreover, mutation characterization, immune cell infiltration, immune evasion, and drug sensitivity of CRFCS in HCC were assessed.ResultsA cuproptosis random forest cox score was built based on a generalization feature of four cuproptosis related genes. Patients in the high CRFCS group exhibited a lower overall survival. Univariate multivariate Cox regression analysis validated CRFCS as an independent prognostic indicator. ROC analysis revealed that CRFCS was a good predictor of HCC (AUC =0.82). Mutation analysis manifested that microsatellite instability (MSI) was significantly increased in the high CRFCS group. Meanwhile, tumor microenvironment analysis showed that the high CRFCS group displayed much more immune cell infiltration compared with the low CRFCS group. The immune escape assessment analysis demonstrated that the high CRFCS group displayed a decreased TIDE score indicating a lower immune escape probability in the high CRFCS group compared with the low CRFCS group. Interestingly, immune checkpoints were highly expressed in the high CRFCS group. Drug sensitivity analysis revealed that HCC patients from the high CRFCS group had a lower IC50 of sorafenib than that from the low CRFCS group.ConclusionsIn this study, we constructed a cuproptosis random forest cox score (CRFCS) model. CRFCS was revealed to be a potential independent prognostic indicator of HCC and high CRFCS samples showed a poor prognosis. Interestingly, CRFCS were correlated with TME characteristics as well as clinical treatment efficacy. Importantly, compared with the low CRFCS group, the high CRFCS group may benefit from immunotherapy and sorafenib treatment

Comparison of BISAP, Ranson, MCTSI, and APACHE II in Predicting Severity and Prognoses of Hyperlipidemic Acute Pancreatitis in Chinese Patients

In recent years, with the developing of living standard, hyperlipidemia becomes the second major reason of acute pancreatitis. It is important to predict the severity and prognosis at early stage of hyperlipidemic acute pancreatitis (HLAP). We compared the BISAP, Ranson, MCTSI, and APACHE II scoring system in predicting MSAP and SAP, local complications, and mortality of HLAP. A total of 326 diagnosed hyperlipidemic acute pancreatitis patients from August 2006 to July 2015 were studied retrospectively. Our result showed that all four scoring systems can be used to predict the severity, local complications, and mortality of HLAP. Ranson did not have significant advantage in predicting severity and prognosis of HLAP compared to other three scoring systems. APACHE II was the best in predicting severity of HLAP, but it had shortcoming in predicting local complications. MCTSI had outstanding performance in predicting local complications, but it was poor in predicting severity and mortality. BISAP score had high accuracy in assessment of severity, local complications, and mortality of HLAP, but the accuracy still needs to be improved in the future

Correlation of Body Mass Index and Waist-Hip Ratio with Severity and Complications of Hyperlipidemic Acute Pancreatitis in Chinese Patients

Hyperlipidemic acute pancreatitis (HLAP) is characterized by critical condition and high recurrence rate compared with non-HLAP. We conducted this study to investigate the value of body mass index and waist-hip ratio in predicting severity and local complications in HLAP. 96 patients with HLAP were categorized by body mass index and waist-hip ratio, respectively. According to the body mass index, they were divided into 3 groups, including normal weight, overweight, and obesity. According to the waist-hip ratio, they were divided into central obesity group and no central obesity group. The body mass index and waist-hip ratio were compared in severity, local complications, and systematic complications of HLAP, using chi-square test and Monte Carlo simulations. The body mass index and waist-hip ratio were correlated with the severity of acute pancreatitis (MAP, MSAP, and SAP), respiratory failure, and circulatory failure in HLAP (p<0.05), but not correlated with the local complications (walled-off necrosis, pancreatic abscess, and pancreatic pseudocyst), renal failure, and gastrointestinal bleeding.The body mass index and waist-hip ratio are valuable in predicting severity and complication in HLAP. We demonstrated that obese patients had an increased risk of developing more serious condition and more complications in HLAP

Continual Exposure to Cigarette Smoke Extracts Induces Tumor-Like Transformation of Human Nontumor Bronchial Epithelial Cells in a Microfluidic Chip

IntroductionHeavy cigarette smoking-related chronic obstructive pulmonary disease is an independent risk factor for lung squamous carcinoma. However, the mechanisms underlying the malignant transformation of bronchial epithelial cells are unclear.MethodsIn our study, human tumor-adjacent bronchial epithelial cells were obtained from 10 cases with smoking-related chronic obstructive pulmonary disease and lung squamous carcinoma and cultured in an established microfluidic chip for continual exposure to cigarette smoke extracts (CSE) to investigate the potential tumor-like transformation and mechanisms. The integrated microfluidic chip included upstream concentration gradient generator and downstream cell culture chambers supplied by flowing medium containing different concentrations of CSE.ResultsOur results showed that continual exposure to low doses of CSE promoted cell proliferation whereas to high doses of CSE triggered cell apoptosis. Continual exposure to CSE promoted reactive oxygen species production in human epithelial cells in a dose-dependent manner. More importantly, continual exposure to low dose of CSE promoted the epithelial-to-mesenchymal transition process and anchorage-independent growth, and increased chromosome instability in bronchial epithelial cells, accompanied by activating the GRP78, NF-κB, and PI3K pathways.ConclusionsThe established microfluidic chip is suitable for primary culture of human tumor-adjacent bronchial epithelial cells to investigate the malignant transformation. Continual exposure to low doses of CSE promoted tumor-like transformation of human nontumor bronchial epithelial cells by inducing reactive oxygen species production and activating the relevant signaling