A Survey on Routing Algorithms for Opportunistic Mobile Social Networks

Opportunistic Mobile Social Networks(OMSNs)are kind of Delay Tolerant Networks(DTNs)that leverage characteristics of Mobile Ad Hoc Networks(MANETs)and Social Networks,particularly the social features,to boost performance of routing algorithms.Users in OMSNs communicate to share and disseminate data to meet needs for variety of applications.Such networks have attracted tremendous attention lately due to the data transmission requirement from emerging applications such as IoT and smart city initiatives.Devices carried by human is the carrier of message transmission,so the social features of human can be used to improve the ability of data transmission.In this paper,we conduct a comparative survey on routing algorithms in OMSNs.We first analyze routing algorithms based on three social features.Since node selfishness is not really considered previously in aforementioned routing algorithms,but has significant impact on network performance,we treat node selfishness as another social feature,classify and elaborate routing algorithms based on incentive mechanism.To assess the impact of social features on routing algorithms,we conducted simulation for six routing algorithms and analyzed the simulation result.Finally,we conclude the paper with challenges on design of routing in OMSNs and point out some future research directions.

Expression and Significance of MicroRNA-21 and P-gp in Colon Cancer Cells

[Objectives]To investigate the expression and significance of miR-21 and P-gp in colon cancer cell line HCT-15.[Methods]RT-qPCR was used to detect the miR-21 and ABCB1 mRNA expression level of P-gp coding genes in normal colon mucosal cell NCM460 and colon cancer cell HCT-15,and Western Blot was used to detect the expression of P-gp in these two cell lines.[Results]The results of RT-qPCR showed that the expression level of miR-21 and ABCB1 mRNA in colon cancer cell HCT-15 was significantly higher than that in normal colon cell NCM460,and the difference was statistically significant(P<0.05).Western Blot results showed that the expression level of P-gp in HCT-15 was significantly higher than that in NCM460,and the difference was statistically significant(P<0.05).[Conclusions]The expression level of miR-21 and ABCB1 mRNA/P-gp in colon cancer cell HCT-15 was higher than that in normal colonic mucosal cell NCM460,and the relationship between miR-21 and multidrug resistance in colon cancer might be related to P-gp.

Expression of P-gp and miRNA-21 in Colorectal Cancer Tissues and the Clinical Significance

[Objectives]To study the expression of P-gp and miRNA-21 in colorectal cancer tissues and the relationship between the expression of P-gp and clinicopathological features,and to analyze the correlation between the expression of miRNA-21 and P-gp.[Methods]Immunohistochemical SP method was used to detect the expression level of P-gp in the tissues of 40 cases of colorectal cancer and the normal mucosal tissues 5 cm away from the corresponding cancer tissues,and the expression level of miRNA-21 in the paraffin tissues of the 40 cases was detected by RT-qPCR.[Results]The positive expression of P-gp was localized in the cell membrane,and the expression in colorectal cancer tissues was significantly higher than that in the corresponding adjacent tissues(P<0.05);the positive expression of P-gp was closely related to the degree of tumor differentiation and the depth of invasion(P<0.05),and the comparison results of P-gp expression in the differentiation groups of different cancer tissues showed that the expression level of P-gp in the moderately and poorly differentiated groups was significantly higher than that in the highly differentiated group(P<0.05),and the expression level of the moderately and poorly differentiated groups was similar(P>0.05).The expression of miRNA-21 in all cancer tissues was higher than that in the corresponding adjacent tissues(P<0.05),and the expression levels of miRNA-21 in differentiation groups of different cancer tissues were 1.286,1.445 and 1.992 times of those in the corresponding adjacent tissues,respectively;the comparison results of miRNA-21 between different differentiation groups showed that the expression level of miRNA-21 in the poorly differentiated group was significantly higher than that in the highly differentiated group and the moderately differentiated group(P<0.05),while the expression level of miRNA-21 in the highly differentiated group and the moderately differentiated group was similar(P>0.05).Spearman correlation analysis showed that there was a positive correlation on the expression between the two in colorectal cancer tissues(r=0.423,P<0.05).[Conclusions]The expression levels of miRNA-21 and P-gp are closely related to the differentiation degree of clinical colorectal cancer,the lower the differentiation degree,the higher the expression level of the two.

Effect of ATM/CHK2/CDC25A Signal Pathway on the Resistance of Colorectal Cancer Cells to L-OHP

[Objectives]To compare the expression of key factors ATM,CHK2,CDC25A and CDK2 in ATM/CHK2/CDC25A signal pathway in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and to explore the relationship between ATM/CHK2/CDC25A signal pathway and resistance of colorectal cancer cells to L-OHP.[Methods]RT-qPCR was used to detect the expression of ATM,CHK2,CDC25A and CDK2 mRNA in colorectal cancer cell line HCT116 and L-OHP-resistant cell line HCT116/L-OHP,and Western blot was used to detect the expression of corresponding proteins in these two cell lines.[Results]The expression of ATM,CHK2,CDC25A,CDK2 mRNA and protein in HCT116/L-OHP was significantly higher than that in HCT116.[Conclusions]ATM/CHK2/CDC25A signal pathway was associated with resistance of colorectal cancer cell line HCT116 to L-OHP.Blocking this signal pathway may partially reverse the chemotherapy resistance of colorectal cancer patients with L-OHP resistance.

Effects of Paeonol Combined with Panax Notoginseng Saponins on Nrf2/ARE Pathway in Rats with Diabetic Cardiomyopathy

[Objectives]To investigate whether paeonol(Pae)combined with panax notoginseng saponins(PNS)can protect the myocardium of rats with diabetic cardiomyopathy(DCM)through improving the antioxidant capacity of the rats by activating the Nrf2/ARE pathway.[Methods]The rats were fed with high-fat and high-sugar diet for 6 weeks,and combined with intraperitoneal injection of small-dose STZ to build a type II diabetes model;the model rats were randomly divided into a model group,a Pae group of 80 mg/kg,and a PNS group of 100 mg/kg,a Pae 80 mg/kg+PNS 100 mg/kg,and a metformin group 157.5 mg/kg;rats of normal group and model group were injected with an equal volume of sodium carboxymethyl cellulose(1%),10 rats in each group.After 8 weeks,3 rats in the model group were taken for histopathological examination.Changes in myocardial fibrosis and myocardial collagen formation indicated that the building of DCM model was successful.qRT-PCR and Western blot were used to detect the expression levels of Nrf2,HO-1,Col-I,and Col-III in myocardial tissue of each group of rats.[Results]Compared with the normal group,the mRNA and protein expression levels of Nrf2 and HO-1 in myocardial tissue of the DCM group rats were significantly reduced,and the mRNA and protein expression levels of Col-I and Col-III were significantly increased;compared with the DCM group,the mRNA and protein expression levels of Nrf2 and HO-1 in the myocardial tissue of each drug group increased to varying degrees,and the combined drug group increased more significantly than that of the single drug group;the mRNA and protein expression levels of Col-I and Col-III were reduced to varying degrees,and the combined drug group declined more significantly than that of the single drug group.[Conclusions]Paeonol combined with panax notoginseng saponins can up-regulate the expression of Nrf2 and HO-1 in myocardial tissue,inhibit the expression of type I and type III collagen.The mechanism may be related to improving the DCM myocardial fibrosis through activating the Nrf2/ARE pathway.

Protective Effect of Paeonol on Diabetic Cardiomyopathy in Rats

[Objectives] The protective effect of paeonol on DCM was further confirmed by observing the changes of myocardial structure and function in rats. [Methods] Rats were fed high-sugar and high-fat diet and injected intraperitoneally with streptozotocin(STZ) for two consecutive days to prepare animal model of type II diabetes. The model rats were randomly divided into model group, low-dose paeonol group(30 mg/kg), middle-dose paeonol group(60 mg/kg), high-dose paeonol group(120 mg/kg) and metformin group(157 mg/kg). The detected indicators included heart weight index(HWI), blood glucose(FBG), body mass, triglyceride(TG), and total cholesterol(TC). Myocardial pathological changes were observed by HE staining. The extent of myocardial fibrosis was observed by Masson staining. [Results] In the model group, the body weight of the rats declined significantly, and the phenomena of overdrinking, overeating and polyuria occurred. Compared with the model group, the body weight of rats in the paeonol treatment groups increased to different extents. Compared with the normal group, the HWI, FBG, LDH, AST, and TG increased in the model group, and decreased in different degrees in the paeonol treatment groups(P<0.05), suggesting that paeonol has certain protective effect on diabetic cardiomyopathy in rats. After HE staining and fixation, the myocardial tissue of rats was observed by optical microscope. The morphology of myocardial cells and myocardial fibers in the normal group were normal;Compared with the normal group, the model group has hypertrophy of myocardial cells, disordered arrangement of myocardial fibers, fiber breakage and dissolution, uneven staining between myocardial cells, and nucleus breakage or even disappearance;Compared with the model group, the pathological changes of myocardium in the paeonol treatment groups and DMBG group have been improved to different degrees. The arrangement of myocardial fibers is regular and the coloration is uniform. The results of Masson staining showed that in the normal group, and there was no significant increase of myocardial collagen fibers in the myocardial interstitium. Compared with the normal group, myocardial cells and interstitial collagen fibers(blue) in the model group were significantly increased. Compared with model group, myocardial collagen fiber hyperplasia in the paeonol treatment groups and DMBG group showed different degrees of improvement, among which the Pae-H group had the least blue bands and the most obvious improvement of collagen fiber. [Conclusions] Paeonol has different degrees of improvement effects on myocardial fibrosis in rats with diabetic cardiomyopathy, suggesting that paeonol has a protective effect on diabetic cardiomyopathy in rats.

Effects of Paeonol on CRP and NF-κB p65 in Rats with Atherosclerosis

[Objectives] The protective mechanism of paeonol on atherosclerotic vessels was investigated by detecting CRP content in the serum and expression of NF-κB p65 in the aorta of atherosclerotic rats. [Methods] An animal model of AS rats was prepared by high-fat diet combined with intraperitoneal injection of VD3. The rats were randomly divided into the normal group,model group,high-dose paeonol group( 120 mg/kg),medium-dose paeonol group( 60 mg/kg),low-dose paeonol group( 30 mg/kg),and simvastatin group( 10 mg/kg) as the positive control group,and drug intervention was continued for 16 weeks. CRP content in the serum was detected by ELISA method,and the expression level of NF-κB p65 was detected by RT-PCR and Western-blot method. [Results]Compared with the normal group,CRP content in the serum and the expression of NF-κB p65 mRNA and protein in the aorta of rats in the model group significantly increased. Compared with the model group,CRP content in the serum dropped obviously,and the expression of NF-κB p65 mRNA and protein in the aorta of rats significantly reduced in the administration groups. Moreover,the improvement of each indicator in the high-dose paeonol group was obviously better than that of the medium-dose and low-dose groups. [Conclusions] Paeonol may protect atherosclerotic vessels by reducing serum CRP content,inhibiting the expression of NF-κB p65 and reducing inflammation.

Preparation of Acute Myocardial Infarction Model for SD Rats and Ventricular Remodeling

[Objectives] To prepare an acute myocardial infarction model for SD rats and conduct ventricular remodeling. [Methods] 45 male Sprague-Dawley( SD) rats were randomly selected in 60 male rats as the model group and the rest rats were sham operation group. For the model group,the left anterior descending coronary artery was ligated,while the sham operation group was not ligated. 4 weeks after the operation,hemodynamics was used to measure the cardiac function of both groups. HE staining and Masson staining were used to observe the changes in myocardial histopathology and myocardial fibrosis of both groups. [Results] Compared with the sham operation group,the model group rats showed significant decrease in the left ventricular systolic pressure( LVSP) and left ventricular pressure maximum rising and dropping rate( ± d_p/d_(tmax)) and significant increase in the left ventricular end-diastolic pressure( LVEDP). HE staining showed that a large number of myocardial cell necrosis occured in the model group,while the morphology of myocardial cells of rats in the sham operation group was normal. Masson staining showed that myocardial collagen fibers in the model group were significantly increased compared with those in the sham operation group. Collagen fibers were scattered in the sham operation group. [Conclusions] It can be concluded that cardiac function of rats changed and ventricular remodeling occurred in 4 weeks after myocardial infarction.

Fault identification scheme for protection and adaptive reclosing in a hybrid multi-terminal HVDC system

A fault identification scheme for protection and adaptive reclosing is proposed for a hybrid multi-terminal HVDC system to increase the reliability of fault isolation and reclosing.By analyzing the"zero passing"characteristic of current at the local end during the converter capacitor discharge stage,the fault identification scheme is proposed.The distributed parameter-based fault location equation,which incorporates fault distance and fault impedance,is developed with the injection signal and the distributed parameter model during the adaptive reclosing stage.The fault distance is determined using a trust region reflection algorithm to identify the permanent fault,and a fault iden-tification scheme for adaptive reclosing is developed.Simulation results show that the proposed scheme is suitable for long-distance transmission lines with strong anti-fault impedance and anti-interference performance.Also,it is less affected by communication delay and DC boundary strength than existing methods.

金属有机框架/聚合物气体分离膜的界面结构设计研究进展

气体分离膜技术在节能减排领域具有突出优势,是一项具有很大发展潜力的气体分离技术.基于金属有机框架/聚合物的混合基质膜兼具聚合物膜材料的易加工性和金属有机框架的优良气体选择吸附特性,受到全球学者的关注.如何有效调控两相界面处微观结构,改善混合基质膜材料的气体分离性能是混合基质膜领域的关键问题.针对这一热点问题,主要综述了近几年学者在金属有机框架/聚合物基混合基质膜的界面结构设计优化、膜材料构效关系研究、膜的规模化制备等领域的研究现状与进展.重点介绍了如何优化与表征界面结构以及金属有机框架与聚合物对膜性能的影响规律两个方面.此外,对混合基质膜材料未来的发展方向进行展望,以期为高性能混合基质膜的理性设计等方面提供研究思路.

Research on the protection coordination of permanent magnet synchronous generator based wind farms with low voltage ride through capability

To coordinate the protection of PMSG(permanent magnet synchronous generator),collector circuits and outgoing lines,a comprehensive and improved protection method of PMSG based wind farms with LVRT(low voltage ride through)capability is proposed.The proposed method includes adding a short time delay to the collector network current protection zone I and a directional protective relaying to the collector network protection,installing grounding transformers and zero sequence current protection,and generator low-voltage protection action improvement.A LVRT scheme consisting of variable resistance dumping circuit,grid side dynamic reactive power control and reactive power compensation control is proposed.The fault characteristics of PMSG based wind farms are analyzed,and a PMSG based wind farm in Dabancheng,Xinjiang,is used as an example to analyze typical wind farm protection configuration,the setting values considering LVRT requirements,and the coordination problems.Finally,an improved wind farm protection coordination methodology is proposed and its validity is verified by simulation.