In recent years,the need for a fast,efficient and a reliable wireless network has increased dramatically.Numerous 5G networks have already been tested while a few are in the early stages of deployment.In noncooperativ...In recent years,the need for a fast,efficient and a reliable wireless network has increased dramatically.Numerous 5G networks have already been tested while a few are in the early stages of deployment.In noncooperative communication scenarios,the recognition of digital signal modulations assists people in identifying the communication targets and ensures an effective management over them.The recent advancements in both Machine Learning(ML)and Deep Learning(DL)models demand the development of effective modulation recognition models with self-learning capability.In this background,the current research article designs aDeep Learning enabled Intelligent Modulation Recognition of Communication Signal(DLIMR-CS)technique for next-generation networks.The aim of the proposed DLIMR-CS technique is to classify different kinds of digitally-modulated signals.In addition,the fractal feature extraction process is appliedwith the help of the Sevcik Fractal Dimension(SFD)approach.Then,the extracted features are fed into the Deep Variational Autoencoder(DVAE)model for the classification of the modulated signals.In order to improve the classification performance of the DVAE model,the Tunicate Swarm Algorithm(TSA)is used to finetune the hyperparameters involved in DVAE model.A wide range of simulations was conducted to establish the enhanced performance of the proposed DLIMR-CS model.The experimental outcomes confirmed the superior recognition rate of the DLIMR-CS model over recent state-of-the-art methods under different evaluation parameters.展开更多
Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, o...Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form the basis for biological control of plant disease. These interactions may employ novel modes of regulation by conserved signaling elements. Tag1, a G protein α subunit of Trichoderma. atroviride belonging to fungal Gi class, is involved in repression of sporulation and hyphal coiling(1). Deletion of ortholog of this gene, TgaA, in Trichoderma (Gliocladium) virens, however, did not affect sporulation and growth, yet tgaA mutants are unable to parasitize S. rolfsii sclerotia(2). Mutation of a second G α subunit gene is now under study. TmkA, a MAPK gene of T. virens, is involved in biocontrol properties and repression of conidiation(3). Using suppression-subtraction hybridization and other approaches, we are beginning to identify additional elements of the signaling cascades and their downsteam targets. The role of G protein and MAPK genes are sometimes specific to a particular host fungus or to parasitism of mycelia or sclerotia(2,3). Also of relevance to biocontrol, signal transduction pathway provide a means to alter the balance between sporulation, mycelial growth and hyphal coiling.展开更多
The activation of the mitogen-activated protein(MAP) kinases extracellular signal-regulated kinase(ERK)1/2 was traditionally used as a readout of signaling of G protein-coupled receptors(GPCRs) via arrestins, as oppos...The activation of the mitogen-activated protein(MAP) kinases extracellular signal-regulated kinase(ERK)1/2 was traditionally used as a readout of signaling of G protein-coupled receptors(GPCRs) via arrestins, as opposed to conventional GPCR signaling via G proteins. Several recent studies using HEK293 cells where all G proteins were genetically ablated or inactivated, or both non-visual arrestins were knocked out, demonstrated that ERK1/2 phosphorylation requires G protein activity, but does not necessarily require the presence of non-visual arrestins. This appears to contradict the prevailing paradigm. Here we discuss these results along with the recent data on gene edited cells and arrestinmediated signaling. We suggest that there is no real controversy. G proteins might be involved in the activation of the upstream-most MAP3Ks, although in vivo most MAP3K activation is independent of heterotrimeric G proteins, being initiated by receptor tyrosine kinases and/or integrins. As far as MAP kinases are concerned, the best-established role of arrestins is scaffolding of the three-tiered cascades(MAP3K-MAP2 K-MAPK). Thus, it seems likely that arrestins, GPCRbound and free, facilitate the propagation of signals in these cascades, whereas signal initiation via MAP3K activation may be independent of arrestins. Different MAP3Ks are activated by various inputs, some of which are mediated by G proteins, particularly in cell culture, where we artificially prevent signaling by receptor tyrosine kinases and integrins, thereby favoring GPCR-induced signaling. Thus, there is no reason to change the paradigm: Arrestins and G proteins play distinct non-overlapping roles in cell signaling.展开更多
Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to ...Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.展开更多
OBJECTIVE Chronic kidney disease(CKD)has become a global public health problem with 10%-15%incidence rate,and inhibiting the renal interstitial fibrosis is considered to be a potential strategy to delay the progressio...OBJECTIVE Chronic kidney disease(CKD)has become a global public health problem with 10%-15%incidence rate,and inhibiting the renal interstitial fibrosis is considered to be a potential strategy to delay the progression of CKD.Z-Guggulsterone(Z-GS),an active compound from derived from Commiphora mukul,has been proved to be effective in various diseases.The present study aimes to determine the protective effect and the molecular mechanism of Z-GS on renal fibrosis.METHODS Unilateral ureteral obstruction(UUO)mice and hypoxia-induced HK-2 cells were used to simulate renal fibrosis in vitro and in vivo,respectively.The mice and cells were treated with different doses of Z-GS to observe the pharmacological action.Renal function,including Scr,BUN,and UA,were detected by commercial kits.H&E and Masson staining were performed to observe histopathological changes of kidney.Cell viability and LDH release of HK-2 cells were detected by commercial kits.Cell cycle distribution and apoptosis rate were analyzed by flow cytometry.Fibrosis markers were detected by immunohistochemistry and immunofluorescence analysis.Cell cycle related proteins and Klotho/p53 signaling were analyzed by Western blotting.RESULTS The results showed that Z-GS decreased the rise of Scr,BUN,and UA and lightened renal histopathological injury,which were induced by UUO.Besides,Z-GS administration alleviated renal fibrosis in mice by inhibiting the expressions ofα-SMA,TGF-βand collagenⅣ,and delayed G2/M cell cycle arrest by promoting the expressions of CDK1 and cyclinD1/B1 rate.Experiments in vitro indicated that Z-GS treatment significantly increased the cell viability while decreased the LDH release in hypoxia-induced HK-2 cells.In addition,hypoxia induced fibrosis and G2/M cycle arrest in HK-2 cells were retarded by Z-GS.The study of its possible mechanism exhibited that Z-GS treatment increased the level of Klotho and inhibited P53 level.Nevertheless,the effect of Z-GS on Klotho/P53 signaling was reversed by siRNA-Klotho.Moreover,siRNA-Klotho treatment eliminated the effects of Z-GS on G2/M cell cycle arrest and fibrosis.CONCLUSION This study clarified that Z-GS alleviated renal fibrosis and G2/M cycle arrest through Klotho/P53 signaling pathway.People who have suffered CKD may potentially benefit from treatment with Z-GS.展开更多
G蛋白偶联受体(G protein-coupled receptors,GPCRs)是一类重要的细胞膜表面7次跨膜蛋白受体超家族,可将多种分子外刺激,包括激素、离子、有机分子和光转化为细胞内“效应器”,目前普遍认为GPCR通路是致癌信号传输的关键路径,G蛋白信号...G蛋白偶联受体(G protein-coupled receptors,GPCRs)是一类重要的细胞膜表面7次跨膜蛋白受体超家族,可将多种分子外刺激,包括激素、离子、有机分子和光转化为细胞内“效应器”,目前普遍认为GPCR通路是致癌信号传输的关键路径,G蛋白信号转导调节因子(regulators of G protein signaling,RGS)蛋白家族是调控GPCR通路的关键蛋白。RGS家族的许多分子在恶性肿瘤的发生和发展中具有重要作用,是癌症诊断、治疗和预后的重要靶点。文章综述了近年来RGS家族在肿瘤发生、发展中的重要作用,阐释了RGS在肿瘤微环境中的独特作用,总结了RGS作用于肿瘤的一般规律,最后介绍一些靶向RGS蛋白的治疗癌症的方法。展开更多
Cochliobolus heterostrophus is an agriculturally important and emerging model pathogen for studying the signaling hierarchies' role during the maize host colonization. In particular, G-protein and MAPK-linked path...Cochliobolus heterostrophus is an agriculturally important and emerging model pathogen for studying the signaling hierarchies' role during the maize host colonization. In particular, G-protein and MAPK-linked pathways are playing a major role during pathogenesis. Although gene disruption studies are an efficient way of identifying the role of these cascades, differentiating between the mutant strains’ virulence ability may become an intricate task. For example, in C. heterostrophus, mutants in a G-protein α subunit gene, cga1, are defective in mating and appressorium formation, but unlike mutants in homologous genes in other fungal pathogens, the cga1 mutants remained highly virulent to corn under some host physiological conditions. Here, we used the cga1 strain as a model for developing an in vivo sensitive and accurate pathogenicity assay. A detailed and well controlled analysis of wild type (WT) and cga1 pathogenic behavior revealed that detached leaves are significantly more vulnerable to the disease than intact ones. In intact leaves, cga1 mutants were less infective of maize under most conditions. This difference was maximized when the first seedling leaf was chosen for inoculation and when the infected leaves, with spores or mycelia fragments droplets, were incubated for a period of four days. This optimal condition set enabled us to classify the C. heterostrophus G-protein signaling mutants deficient in α, β or both subunits in order of decreasing virulence: WT > cga1> cgb1> cga1 cgb1. The method presented proved to be accurate and sensitive enough to identify even slight variations in virulence. Moreover, it could be modified for use in studies of other foliar phytoparasitic fungi.展开更多
【目的】观察苦瓜皂苷G对糖尿病肾病(DN)大鼠的治疗作用及机制。【方法】从55只大鼠中随机抽取45只采用一次性腹腔注射链脲佐菌素(STZ)法诱导DN模型。将造模成功的38只大鼠随机分为模型组9只、苦瓜皂苷G低剂量组9只、苦瓜皂苷G中剂量组1...【目的】观察苦瓜皂苷G对糖尿病肾病(DN)大鼠的治疗作用及机制。【方法】从55只大鼠中随机抽取45只采用一次性腹腔注射链脲佐菌素(STZ)法诱导DN模型。将造模成功的38只大鼠随机分为模型组9只、苦瓜皂苷G低剂量组9只、苦瓜皂苷G中剂量组10只、苦瓜皂苷G高剂量组10只。剩余10只大鼠设为正常组。对应灌胃给药4周后,酶联免疫吸附分析(ELISA)检测大鼠24 h尿蛋白水平,血糖仪检测空腹血糖(FBG),全自动生化分析仪检测血肌酐(SCr)、血尿素氮(BUN)水平,苏木素-伊红染色(HE)法观察大鼠肾组织病理学变化,采用实时定量聚合酶链反应(RT-qPCR)和Western Blot法分别检测E-钙黏蛋白(E-cad)、α-平滑肌肌动蛋白(α-SMA)、Notch1、锌指蛋白转录因子1(Snail1)、Jagged1 m RNA及蛋白表达情况。【结果】与正常组比较,模型组24 h尿蛋白、FBG、血清SCr和BUN水平及肾组织α-SMA、Notch1、Snail1、Jagged1 mRNA及蛋白水平显著升高,肾组织E-cad m RNA及蛋白水平降低,肾组织可见肾小球萎缩、肾小管扩张及间质纤维化;与模型组比较,苦瓜皂苷G低、中、高剂量组24 h尿蛋白、FBG、血清SCr和BUN水平及肾组织α-SMA、Notch1、Snail1、Jagged1 mRNA及蛋白水平显著降低,肾组织E-cad m RNA及蛋白水平升高,肾组织病理损伤得到改善。【结论】苦瓜皂苷G可有效改善DN大鼠肾功能障碍、减轻肾脏纤维化,其机制可能与通过调控Notch/Snail1信号通路,抑制α-SMA和Jagged1 mRNA及蛋白表达,增强E-cad mRNA及蛋白表达有关。展开更多
A novel class of periodically changing features hidden in radar pulse sequence environment,named G features,is proposed.Combining fractal theory and Hilbert-Huang transform,the features are extracted using changing ch...A novel class of periodically changing features hidden in radar pulse sequence environment,named G features,is proposed.Combining fractal theory and Hilbert-Huang transform,the features are extracted using changing characteristics of pulse parameters in radar emitter signals.The features can be applied in modern complex electronic warfare environment to address the issue of signal sorting when radar emitter pulse signal parameters severely or even completely overlap.Experiment results show that the proposed feature class and feature extraction method can discriminate periodically changing pulse sequence signal sorting features from radar pulse signal flow with complex variant features,therefore provide a new methodology for signal sorting.展开更多
In the future the fifth generation( 5 G) communication systems,channel models may be very complicated and it is difficult to calculate equivalent signal to interference plus noise ratio( SINR)of a random fading channe...In the future the fifth generation( 5 G) communication systems,channel models may be very complicated and it is difficult to calculate equivalent signal to interference plus noise ratio( SINR)of a random fading channel. Therefore,methods for the calculation of equivalent SINR of a random fading channel are very necessary.In this paper,an enhanced algorithm on the exponential effective SINR mapping( EESM) model for random fading channels was proposed. First, the optimal adjustment parameters of typical channel fading models including extended pedestrian A( EPA)model,extended vehicular A( EVA) model and extended typical urban( ETU) model were obtained by simulation. Then the proposed solution was used to actualize channel classification according to the maximum multipath delay and the average power of the random channel. The solution can determine the typical channel closest to random channel for obtaining the optimal adjustment value of EESM. The evaluation results indicate that the proposed one can improve the whole system throughput significantly and meanwhile the accuracy of the link prediction algorithm is also guaranteed.展开更多
文摘In recent years,the need for a fast,efficient and a reliable wireless network has increased dramatically.Numerous 5G networks have already been tested while a few are in the early stages of deployment.In noncooperative communication scenarios,the recognition of digital signal modulations assists people in identifying the communication targets and ensures an effective management over them.The recent advancements in both Machine Learning(ML)and Deep Learning(DL)models demand the development of effective modulation recognition models with self-learning capability.In this background,the current research article designs aDeep Learning enabled Intelligent Modulation Recognition of Communication Signal(DLIMR-CS)technique for next-generation networks.The aim of the proposed DLIMR-CS technique is to classify different kinds of digitally-modulated signals.In addition,the fractal feature extraction process is appliedwith the help of the Sevcik Fractal Dimension(SFD)approach.Then,the extracted features are fed into the Deep Variational Autoencoder(DVAE)model for the classification of the modulated signals.In order to improve the classification performance of the DVAE model,the Tunicate Swarm Algorithm(TSA)is used to finetune the hyperparameters involved in DVAE model.A wide range of simulations was conducted to establish the enhanced performance of the proposed DLIMR-CS model.The experimental outcomes confirmed the superior recognition rate of the DLIMR-CS model over recent state-of-the-art methods under different evaluation parameters.
文摘Filamentous fungi employ conserved eukaryotic signaling pathway to detect and respond to environmental signals, including the presence of the host. Genetic experiment in which a particular signaling protein is lost, or its activity enhanced, have defined some of the function of heterotrimeric G proteins and MAP kinases in development and virulence. A hallmark of these studies is that orthologs in different species may have different functions. Antagonistic fungal-fungal interactions form the basis for biological control of plant disease. These interactions may employ novel modes of regulation by conserved signaling elements. Tag1, a G protein α subunit of Trichoderma. atroviride belonging to fungal Gi class, is involved in repression of sporulation and hyphal coiling(1). Deletion of ortholog of this gene, TgaA, in Trichoderma (Gliocladium) virens, however, did not affect sporulation and growth, yet tgaA mutants are unable to parasitize S. rolfsii sclerotia(2). Mutation of a second G α subunit gene is now under study. TmkA, a MAPK gene of T. virens, is involved in biocontrol properties and repression of conidiation(3). Using suppression-subtraction hybridization and other approaches, we are beginning to identify additional elements of the signaling cascades and their downsteam targets. The role of G protein and MAPK genes are sometimes specific to a particular host fungus or to parasitism of mycelia or sclerotia(2,3). Also of relevance to biocontrol, signal transduction pathway provide a means to alter the balance between sporulation, mycelial growth and hyphal coiling.
基金Supported by National Institutes of Health RO1 grants,No.EY011500National Institutes of Health R35 grants,No.GM122491Cornelius Vanderbilt Endowed Chair(Vanderbilt University),No.NS065868(to Gurevich VV)and No.DA030103(to Gurevich EV)
文摘The activation of the mitogen-activated protein(MAP) kinases extracellular signal-regulated kinase(ERK)1/2 was traditionally used as a readout of signaling of G protein-coupled receptors(GPCRs) via arrestins, as opposed to conventional GPCR signaling via G proteins. Several recent studies using HEK293 cells where all G proteins were genetically ablated or inactivated, or both non-visual arrestins were knocked out, demonstrated that ERK1/2 phosphorylation requires G protein activity, but does not necessarily require the presence of non-visual arrestins. This appears to contradict the prevailing paradigm. Here we discuss these results along with the recent data on gene edited cells and arrestinmediated signaling. We suggest that there is no real controversy. G proteins might be involved in the activation of the upstream-most MAP3Ks, although in vivo most MAP3K activation is independent of heterotrimeric G proteins, being initiated by receptor tyrosine kinases and/or integrins. As far as MAP kinases are concerned, the best-established role of arrestins is scaffolding of the three-tiered cascades(MAP3K-MAP2 K-MAPK). Thus, it seems likely that arrestins, GPCRbound and free, facilitate the propagation of signals in these cascades, whereas signal initiation via MAP3K activation may be independent of arrestins. Different MAP3Ks are activated by various inputs, some of which are mediated by G proteins, particularly in cell culture, where we artificially prevent signaling by receptor tyrosine kinases and integrins, thereby favoring GPCR-induced signaling. Thus, there is no reason to change the paradigm: Arrestins and G proteins play distinct non-overlapping roles in cell signaling.
基金supported by grants from the Ministerio de Economia y Competitividad(BFU2013-43458-R)Junta de Andalucia(P12-CTS-1694 and Proyexcel-00422)to ZUK。
文摘Memory deficit,which is often associated with aging and many psychiatric,neurological,and neurodegenerative diseases,has been a challenging issue for treatment.Up till now,all potential drug candidates have failed to produce satisfa ctory effects.Therefore,in the search for a solution,we found that a treatment with the gene corresponding to the RGS14414protein in visual area V2,a brain area connected with brain circuits of the ventral stream and the medial temporal lobe,which is crucial for object recognition memory(ORM),can induce enhancement of ORM.In this study,we demonstrated that the same treatment with RGS14414in visual area V2,which is relatively unaffected in neurodegenerative diseases such as Alzheimer s disease,produced longlasting enhancement of ORM in young animals and prevent ORM deficits in rodent models of aging and Alzheimer’s disease.Furthermore,we found that the prevention of memory deficits was mediated through the upregulation of neuronal arbo rization and spine density,as well as an increase in brain-derived neurotrophic factor(BDNF).A knockdown of BDNF gene in RGS14414-treated aging rats and Alzheimer s disease model mice caused complete loss in the upregulation of neuronal structural plasticity and in the prevention of ORM deficits.These findings suggest that BDNF-mediated neuronal structural plasticity in area V2 is crucial in the prevention of memory deficits in RGS14414-treated rodent models of aging and Alzheimer’s disease.Therefore,our findings of RGS14414gene-mediated activation of neuronal circuits in visual area V2 have therapeutic relevance in the treatment of memory deficits.
基金National Natural Science Foundation of China(82003982)Natural Science Foundation of Gansu Province(20JR5RA591+1 种基金20JR10R015)and Special Cultivation Project of the 940th Hospital(2021yxky026)。
文摘OBJECTIVE Chronic kidney disease(CKD)has become a global public health problem with 10%-15%incidence rate,and inhibiting the renal interstitial fibrosis is considered to be a potential strategy to delay the progression of CKD.Z-Guggulsterone(Z-GS),an active compound from derived from Commiphora mukul,has been proved to be effective in various diseases.The present study aimes to determine the protective effect and the molecular mechanism of Z-GS on renal fibrosis.METHODS Unilateral ureteral obstruction(UUO)mice and hypoxia-induced HK-2 cells were used to simulate renal fibrosis in vitro and in vivo,respectively.The mice and cells were treated with different doses of Z-GS to observe the pharmacological action.Renal function,including Scr,BUN,and UA,were detected by commercial kits.H&E and Masson staining were performed to observe histopathological changes of kidney.Cell viability and LDH release of HK-2 cells were detected by commercial kits.Cell cycle distribution and apoptosis rate were analyzed by flow cytometry.Fibrosis markers were detected by immunohistochemistry and immunofluorescence analysis.Cell cycle related proteins and Klotho/p53 signaling were analyzed by Western blotting.RESULTS The results showed that Z-GS decreased the rise of Scr,BUN,and UA and lightened renal histopathological injury,which were induced by UUO.Besides,Z-GS administration alleviated renal fibrosis in mice by inhibiting the expressions ofα-SMA,TGF-βand collagenⅣ,and delayed G2/M cell cycle arrest by promoting the expressions of CDK1 and cyclinD1/B1 rate.Experiments in vitro indicated that Z-GS treatment significantly increased the cell viability while decreased the LDH release in hypoxia-induced HK-2 cells.In addition,hypoxia induced fibrosis and G2/M cycle arrest in HK-2 cells were retarded by Z-GS.The study of its possible mechanism exhibited that Z-GS treatment increased the level of Klotho and inhibited P53 level.Nevertheless,the effect of Z-GS on Klotho/P53 signaling was reversed by siRNA-Klotho.Moreover,siRNA-Klotho treatment eliminated the effects of Z-GS on G2/M cell cycle arrest and fibrosis.CONCLUSION This study clarified that Z-GS alleviated renal fibrosis and G2/M cycle arrest through Klotho/P53 signaling pathway.People who have suffered CKD may potentially benefit from treatment with Z-GS.
文摘G蛋白偶联受体(G protein-coupled receptors,GPCRs)是一类重要的细胞膜表面7次跨膜蛋白受体超家族,可将多种分子外刺激,包括激素、离子、有机分子和光转化为细胞内“效应器”,目前普遍认为GPCR通路是致癌信号传输的关键路径,G蛋白信号转导调节因子(regulators of G protein signaling,RGS)蛋白家族是调控GPCR通路的关键蛋白。RGS家族的许多分子在恶性肿瘤的发生和发展中具有重要作用,是癌症诊断、治疗和预后的重要靶点。文章综述了近年来RGS家族在肿瘤发生、发展中的重要作用,阐释了RGS在肿瘤微环境中的独特作用,总结了RGS作用于肿瘤的一般规律,最后介绍一些靶向RGS蛋白的治疗癌症的方法。
文摘Cochliobolus heterostrophus is an agriculturally important and emerging model pathogen for studying the signaling hierarchies' role during the maize host colonization. In particular, G-protein and MAPK-linked pathways are playing a major role during pathogenesis. Although gene disruption studies are an efficient way of identifying the role of these cascades, differentiating between the mutant strains’ virulence ability may become an intricate task. For example, in C. heterostrophus, mutants in a G-protein α subunit gene, cga1, are defective in mating and appressorium formation, but unlike mutants in homologous genes in other fungal pathogens, the cga1 mutants remained highly virulent to corn under some host physiological conditions. Here, we used the cga1 strain as a model for developing an in vivo sensitive and accurate pathogenicity assay. A detailed and well controlled analysis of wild type (WT) and cga1 pathogenic behavior revealed that detached leaves are significantly more vulnerable to the disease than intact ones. In intact leaves, cga1 mutants were less infective of maize under most conditions. This difference was maximized when the first seedling leaf was chosen for inoculation and when the infected leaves, with spores or mycelia fragments droplets, were incubated for a period of four days. This optimal condition set enabled us to classify the C. heterostrophus G-protein signaling mutants deficient in α, β or both subunits in order of decreasing virulence: WT > cga1> cgb1> cga1 cgb1. The method presented proved to be accurate and sensitive enough to identify even slight variations in virulence. Moreover, it could be modified for use in studies of other foliar phytoparasitic fungi.
文摘【目的】观察苦瓜皂苷G对糖尿病肾病(DN)大鼠的治疗作用及机制。【方法】从55只大鼠中随机抽取45只采用一次性腹腔注射链脲佐菌素(STZ)法诱导DN模型。将造模成功的38只大鼠随机分为模型组9只、苦瓜皂苷G低剂量组9只、苦瓜皂苷G中剂量组10只、苦瓜皂苷G高剂量组10只。剩余10只大鼠设为正常组。对应灌胃给药4周后,酶联免疫吸附分析(ELISA)检测大鼠24 h尿蛋白水平,血糖仪检测空腹血糖(FBG),全自动生化分析仪检测血肌酐(SCr)、血尿素氮(BUN)水平,苏木素-伊红染色(HE)法观察大鼠肾组织病理学变化,采用实时定量聚合酶链反应(RT-qPCR)和Western Blot法分别检测E-钙黏蛋白(E-cad)、α-平滑肌肌动蛋白(α-SMA)、Notch1、锌指蛋白转录因子1(Snail1)、Jagged1 m RNA及蛋白表达情况。【结果】与正常组比较,模型组24 h尿蛋白、FBG、血清SCr和BUN水平及肾组织α-SMA、Notch1、Snail1、Jagged1 mRNA及蛋白水平显著升高,肾组织E-cad m RNA及蛋白水平降低,肾组织可见肾小球萎缩、肾小管扩张及间质纤维化;与模型组比较,苦瓜皂苷G低、中、高剂量组24 h尿蛋白、FBG、血清SCr和BUN水平及肾组织α-SMA、Notch1、Snail1、Jagged1 mRNA及蛋白水平显著降低,肾组织E-cad m RNA及蛋白水平升高,肾组织病理损伤得到改善。【结论】苦瓜皂苷G可有效改善DN大鼠肾功能障碍、减轻肾脏纤维化,其机制可能与通过调控Notch/Snail1信号通路,抑制α-SMA和Jagged1 mRNA及蛋白表达,增强E-cad mRNA及蛋白表达有关。
基金supported by the National Natural Science Foundation of China (60872108)the Postdoctoral Science Foundation of China(200902411+3 种基金20080430903)Heilongjiang Postdoctoral Financial Assistance (LBH-Z08129)the Scientific and Technological Creative Talents Special Research Foundation of Harbin Municipality (2008RFQXG030)Central University Basic Research Professional Expenses Special Fund Project
文摘A novel class of periodically changing features hidden in radar pulse sequence environment,named G features,is proposed.Combining fractal theory and Hilbert-Huang transform,the features are extracted using changing characteristics of pulse parameters in radar emitter signals.The features can be applied in modern complex electronic warfare environment to address the issue of signal sorting when radar emitter pulse signal parameters severely or even completely overlap.Experiment results show that the proposed feature class and feature extraction method can discriminate periodically changing pulse sequence signal sorting features from radar pulse signal flow with complex variant features,therefore provide a new methodology for signal sorting.
基金Institute of Nonlinear Science of Donghua University,China
文摘In the future the fifth generation( 5 G) communication systems,channel models may be very complicated and it is difficult to calculate equivalent signal to interference plus noise ratio( SINR)of a random fading channel. Therefore,methods for the calculation of equivalent SINR of a random fading channel are very necessary.In this paper,an enhanced algorithm on the exponential effective SINR mapping( EESM) model for random fading channels was proposed. First, the optimal adjustment parameters of typical channel fading models including extended pedestrian A( EPA)model,extended vehicular A( EVA) model and extended typical urban( ETU) model were obtained by simulation. Then the proposed solution was used to actualize channel classification according to the maximum multipath delay and the average power of the random channel. The solution can determine the typical channel closest to random channel for obtaining the optimal adjustment value of EESM. The evaluation results indicate that the proposed one can improve the whole system throughput significantly and meanwhile the accuracy of the link prediction algorithm is also guaranteed.
