47 research outputs found
Design and Implementation of a Wireless ZigBee Mesh Network
ZigBee is officially a wireless network protocol that is designed to be used with the low-data-rate sensor and control networks. The objective of this thesis was to implement a ZigBee mesh network with XBee 802.15.4 RF module and Raspberry Pi. The target was to make a mesh network with three nodes. The project consists of two parts: using the X-CTU application to implement the ZigBee network with XBee RF modules, XBee 802.15.4 Starter Development Kit and XBee Adapter Board, and then the implementation of the ZigBee network with XBee RF modules and Raspberry Pi. This project was to implement a wireless mesh network with three XBee RF modules in the Linux programming environment of Raspberry Pi. Of course, this implementation could be improved in a large mesh network with lots of wireless modules in the future. The thesis concentrates on how to build a mesh network. In a mesh network, more than two nodes can communicate with each other. First the wireless communication between two XBee RF modules was built, and then the third XBee RF module was added into this network. Finally, this mesh network was tested to see, how the mesh network works.The result of this project brings a feedback of the mesh network. If a node is in unicast mode, it can provide a peer-to-peer communication. However, if a node is in broadcast mode, it can send data to all the other nodes in a same personal area network. In conclusion, in a mesh network, there is at least one node is in a broadcast mode, and the DL address of other nodes should be same as MY address of the broadcast node. Otherwise a mesh network cannot be built
Controllable synthesis of biomimetic nano/submicro-fibrous tubes for potential small-diameter vascular grafts
Mimicking the morphological structure of native blood vessels is critical for the development of vascular grafts. Herein, small-diameter composite vascular grafts that integrate the nanofibrous bacterial cellulose (BC) and submicrofibrous cellulose acetate (CA) were fabricated via a combined electrospinning and step-by-step in situ biosynthesis. Scanning electron microscopy (SEM) observation shows the nano/submicro-fibrous morphology and well-interconnected porous structure of the BC/CA grafts. It is found that the BC/CA graft with a suitable BC content demonstrates lower potential of thrombus formation and enhanced endothelialization as compared to the BC and CA counterparts. Western blotting and RT-qPCR results suggest that the BC/CA-2 graft promotes endothelialization by improving expressions of genes vWF-1 and CD31 and protein CD31. The in vivo tests demonstrate much lower inflammatory response to the BC/CA graft. These results suggest that the BC/CA graft shows a great potential as an artificial graft for rapid formation of an endothelial cell monolayer.National Natural Science Foundation of China (Grant no. 51973058, 31870963, 31760265) and Key Research and Development Program of Jiangxi Province (No. 20192ACB80008)info:eu-repo/semantics/publishedVersio
Novel mechanisms in control of SIRT1 stability during DNA damage response.
Ph.DDOCTOR OF PHILOSOPHY (SOM
An Improved Mixed Integer Linear Programming Approach Based on Symmetry Diminishing for Unit Commitment of Hybrid Power System
In this paper, the mixed integer linear programming (MILP) for solving unit commitment (UC) problems in a hybrid power system containing thermal, hydro, and wind power have been studied. To promote its efficiency, an improved MILP approach has been proposed, while the symmetric problem in MILP formulas has been solved by reforming hierarchical constraints. Experiments on different scales have been conducted to demonstrate the effectiveness of the proposed approach. The results indicate a dramatic efficiency promotion compared to other popular MILP approaches in large scale power systems. Additionally, the proposed approach has been applied in UC problems of the hybrid power system. Two indexes, fluctuation degree and output degree, have been proposed to investigate the performance of renewable energy sources (RES). Several experiments are also implemented and the results show that the integration of pumped hydroelectric energy storage (PHES) can decrease the output of thermal units, as well as balance wind power fluctuation according to the load demand
Increased modified DUBLIN scores are associated with serious ulcerative colitis and treatment failure
Background: Grading of endoscopic lesions is important for determining the severity of ulcerative colitis and developing treatment strategies, but the commonly used methods are not sufficient. Objectives: This study aimed to investigate whether new endoscopic scoring systems incorporating lesions and disease extent are associated with clinical disease severity and maintainable remission. Design: This was a retrospective study. In all, 110 patients with ulcerative colitis were included and 87 completed 12-month follow-up. Methods: Colonoscopy was performed within 1 week before blood samples were taken. Degree of ulcerative colitis burden of luminal inflammation (DUBLIN) scores were calculated as the product of Mayo endoscopic score (MES) by disease extent and ulcerative colitis endoscopic index of severity was used to replace MES when calculating modified DUBLIN scores. Results: DUBLIN and modified DUBLIN scores were increased in the moderate and severe groups significantly ( p 7) were associated with an increased risk of treatment failure (hazard ratio = 4.96, 95% confidence interval: 1.17–21.00, p = 0.03), but there were no association between DUBLIN scores and long-term remission ( p > 0.05). Conclusion: Increased DUBLIN and modified DUBLIN scores were conducive to screening serious disease, but only modified DUBLIN scores had the potential to assist in making an upgraded therapeutic schedule
Urgent interventional bilateral renal artery fenestration for giant pararenal abdominal aortic aneurysm with upper digestive tract obstruction
An Improved Mixed Integer Linear Programming Approach Based on Symmetry Diminishing for Unit Commitment of Hybrid Power System
All-optical dynamic tuning of local excitonic emission of monolayer MoS2 by integration with Ge2Sb2Te5
Strong quantum confinement and coulomb interactions induce tightly bound quasiparticles such as excitons and trions in an atomically thin layer of transitional metal dichalcogenides (TMDs), which play a dominant role in determining their intriguing optoelectronic properties. Thus, controlling the excitonic properties is essential for the applications of TMD-based devices. Here, we demonstrate the all-optical tuning of the local excitonic emission from a monolayer MoS2 hybridized with phase-change material Ge2Sb2Te5 (GST) thin film. By applying pulsed laser with different power on the MoS2/GST heterostructure, the peak energies of the excitonic emission of MoS2 can be tuned up to 40 meV, and the exciton/trion intensity ratio can be tuned by at least one order of magnitude. Raman spectra and transient pump-probe measurements show that the tunability originated from the laser-induced phase change of the GST thin film with charge transferring from GST to the monolayer MoS2. The dynamic tuning of the excitonic emission was all done with localized laser pulses and could be scaled readily, which pave a new way of controlling the excitonic emission in TMDs. Our findings could be potentially used as all-optical modulators or switches in future optical networks
Development and validation of a nomogram for predicting prognosis of high-grade chondrosarcoma: A surveillance, epidemiology, and end results-based population analysis
Background The incidence of chondrosarcoma is increasing every year, and the treatment and prognosis of patients with high-grade chondrosarcoma are becoming more and more important. Nomogram is a tool that can quickly and easily predict the overall survival of tumor patients. Therefore, the development and validation of a nomogram to predict overall survival in patients with high-grade chondrosarcoma was desired. Methods We retrospectively collected 396 patients with high-grade chondrosarcoma from the Surveillance, Epidemiology, and End Results (SEER) database from 2004 to 2015. Randomly divided into model and validation groups, the best cut-off values for age and tumor size grouping were derived by using X-tile software. Then, independent prognostic factors for high-grade chondrosarcoma were derived by SPSS.26 univariate and multivariate Cox analyses analysis in the model group, and the model was evaluated by using R software, using C-indix and ROC curves, and finally these independent prognostic factors were included in Nomogram. Results 396 patients were randomly assigned to the modelling group (n = 280) or the validation group (n = 116). Age, tissue-type, tumor size, AJCC stage, regional expansion and surgery were identified as independent prognostic factors ( p < 0.05) which further combined to construct a nomogram. The C-index of internal validation for overall survival(OS) was 0.757, while the C-index of external validation for overall survival(OS) was 0.832. Both internal and external calibration curves show a good agreement between nomogram prediction and actual survival. Conclusion In this study, we established age, tumour size, AJCC stage, tissue type, surgery and tumor extension as independent prognostic factors for high-grade chondrosarcoma and constructed a nomogram to predict 3- and 5-year survival rates for high-grade chondrosarcoma
Data_Sheet_1_Effects of dietary tryptophan supplementation on rectal temperature, humoral immunity, and cecal microflora composition of heat-stressed broilers.ZIP
This trial aimed to determine the effects of tryptophan (Trp) on the rectal temperature, hormone, humoral immunity, and cecal microflora composition in broiler chickens under heat stress (HS). One hundred and eighty 18 days-old female Arbor Acres broilers were randomly divided into three treatment groups, with six replicates of ten birds in each replicate. The broilers were either raised under thermoneutral conditions (TN, 23 ± 1°C) or subjected to heat stress (34 ± 1°C for 8 h daily). The TN group received a basal diet, and another two heat-stressed groups were fed the basal diet (HS) or the basal diet supplemented with 0.18% Trp (HS + 0.18% Trp) for 21 consecutive days. The basal diet contained 0.18% Trp. Results revealed that HS increased the rectal temperature, serum epinephrine (EPI), and corticotropin-releasing hormone (CRH) concentrations (p < 0.05), reduced the bursal index, the levels of serum immunoglobulin A (IgA), IgG, IgM, and serotonin (5-HT) as well as the relative abundance of Actinobacteria in cecum (p < 0.05) compared with the TN group. Dietary supplementation of Trp decreased the rectal temperature, serum dopamine (DA), EPI, and the levels of CRH and L-kynurenine (p < 0.05), increased the bursal index, the levels of serum IgA, IgM, and 5-HT as well as the relative abundance of Ruminococcus torques group in cecum of heat-stressed broilers (p < 0.05) compared to HS group. In conclusion, dietary Trp supplementation decreased rectal temperature, improved cecal microbiota community and Trp metabolism, and enhanced humoral immunity of heat-stressed broilers.</p