RESUMO
Stegosaurs are a minor but iconic clade of ornithischian dinosaurs, yet due to a poor fossil record, their early evolution is poorly understood. Here, we describe a new stegosaur, Baiyinosaurus baojiensis, gen. et sp. nov. from the Middle Jurassic Wangjiashan Formation of the Pingchuan District, Baiyin City, Gansu Province, China. The frontal of Baiyinosaurus possesses a unique characteristic among Stegosauria: it is wider than long and contributes to both the medial and anterior margins of the supratemporal fenestra. The character combinations of dorsal vertebrae of Baiyinosaurus are also different to other stegosaurs: its neural arches are not greatly elongated, its parapophyses are well developed, and its neural spines are axially expanded in lateral. The features of the frontal and vertebrae of Baiyinosaurus are reminiscent of basally branching thyreophorans, indicating that Baiyinosaurus is transitional in morphology between early thyreophorans and early-diverging stegosaurs. Systematic analysis shows that Baiyinosaurus is an early-diverging stegosaur.
Assuntos
Dinossauros , Fósseis , Dinossauros/anatomia & histologia , Dinossauros/classificação , Animais , China , Fósseis/anatomia & histologia , Filogenia , Coluna Vertebral/anatomia & histologia , Evolução BiológicaRESUMO
A network is considered observable if its current state can be determined in finite time from knowledge of the observed states. The observability transitions in networks based on random or degree-correlated sensor placement have recently been studied. However, these placement strategies are predominantly based on local information regarding the network. In this paper, to understand the phase transition process of network observability, we analyze the network observability transition for a betweenness-based sensor placement strategy, in which sensors are placed on nodes according to their betweenness. Using numerical simulations, we compute the size of the network's largest observable component (LOC) and compare the observability transitions for different sensor placements. We find that betweenness-based sensor placement can generate a larger LOC in the observability transition than the random or degree-based placement strategy in both model and real networks. This finding may help to understand the relationship between network observability and the topological properties of the network.
Assuntos
Aviação , Simulação por Computador , Modelos Biológicos , Modelos Teóricos , Mapas de Interação de Proteínas , Algoritmos , Proteínas Fúngicas/metabolismo , Leveduras/metabolismoRESUMO
Cascading failures have become major threats to network robustness due to their potential catastrophic consequences, where local perturbations can induce global propagation of failures. Unlike failures spreading via direct contacts due to structural interdependencies, overload failures usually propagate through collective interactions among system components. Despite the critical need in developing protection or mitigation strategies in networks such as power grids and transportation, the propagation behavior of cascading failures is essentially unknown. Here we find by analyzing our collected data that jams in city traffic and faults in power grid are spatially long-range correlated with correlations decaying slowly with distance. Moreover, we find in the daily traffic, that the correlation length increases dramatically and reaches maximum, when morning or evening rush hour is approaching. Our study can impact all efforts towards improving actively system resilience ranging from evaluation of design schemes, development of protection strategies to implementation of mitigation programs.
RESUMO
In recent years, robot-assisted surgery (RAS) has developed rapidly and become one of the hot topics in clinical research. Compared with traditional surgery, RAS has advantages in terms of minimal invasiveness, aesthetics, and functional preservation, and has been gradually applied in clinical practice such as neurosurgery, urology, and head and neck surgery. In the treatment of head and neck tumors, RAS can effectively minimize the surgical injury and accelerate postoperative recovery. This article reviews the application of RAS in the resection of primary lesions of head and neck tumors, neck dissection, and reconstruction of tissue defects.
RESUMO
OBJECTIVE: To study the effect and mechanism of tetrandrine (Tet) on enhancing radiosensitivity of human nasopharyngeal carcinoma cell lines in vitro. METHODS: CNE1 and CNE2 were exposed to radiation with or without Tet, the DNA damage of the cells were evaluated by neutral comet electrophoresis, and cell cycle and apoptosis were analyzed by flow cytometry. RESULTS: The mean tail movements (TM) of CNE1 treated with radiation or radiation plus Tet were (7.13 ± 3.70) (X(-) ± s) and (13.61 ± 5.45), respectively (t = 2.784, P < 0.05), and TM of CNE2 treated with radiation or radiation plus Tet were (11.52 ± 4.04) and (18.85 ± 6.18), respectively (t = 3.089, P < 0.05). With the exposure to radiation or radiation plus Tet, the percentages of CNE1 in G2 phases were (42.62 ± 2.07)% and (17.02 ± 1.87)%, respectively (t = 23.173, P < 0.01), and the percentages of CNE2 in G2 phases were (34.82 ± 2.74)% and (19.64 ± 4.82)%, respectively(t = 16.500, P < 0.01). There was no significant difference in the apoptosis rates between the cells treated with radiation or radiation plus Tet regardless of CNE1 (17.24 ± 0.99)% vs (19.11 ± 1.24)%, and CNE2 (16.68 ± 0.27)% vs (18.51 ± 2.41)% (P > 0.05). CONCLUSIONS: Tet can enhance radiosensitivity of human nasopharyngeal carcinoma cell lines. The mechanism could be related to abrogation of radiation-induced G2/M arrest and reduction of double-strand break repair capacity.
Assuntos
Benzilisoquinolinas/farmacologia , Benzilisoquinolinas/toxicidade , Tolerância a Radiação/efeitos dos fármacos , Apoptose/efeitos dos fármacos , Benzilisoquinolinas/administração & dosagem , Carcinoma , Linhagem Celular Tumoral , Reparo do DNA , Humanos , Carcinoma Nasofaríngeo , Neoplasias Nasofaríngeas , Metástase NeoplásicaRESUMO
Objective To analyze the correlation between the direct measurement of pulmonary artery pressure and the related echocardiographic parameters in rats with pulmonary arterial hypertension ( PA H ) , and establish a predictable equation for pulmonary artery pressure using non‐invasive ultrasonic parameters . Methods Fifteen male Wistar rats were randomly divided into normal control ( NC ) group with five rats and PA H model group with 10 rats .PA H model was established by intraperitoneal injection of 1% MCT solution in the dose of 60 mg/kg . All the rats were examined by ultrasonic apparatus to record cardiac parameters including right ventricle anterior wall thickness ( RVAWT ) ,pulmonary artery diameter ( PAD) , aorta diameter ( AOD ) , pulmonary artery acceleration time ( PAAT ) , pulmonary artery ejection time ( PAET ) ,right ventricle end‐diastolic diameter ( RVEDD ) ,right ventricle end‐diastolic length ( RVEDL ) , tricuspid annular plane systolic excursion ( T APSE) and left ventricular ejection fraction ( LVEF ) before experiments as well as 2 and 4 weeks after modeling . At the fifth week of modeling ,all the rats were administrated with thoracotomy and right ventricular catheter to obtain pulmonary artery systolic ,diastolic and mean pressures ( PASP ,PADP and PAM P) . Results As time went on ,measures of RVAWT ,PAD , PAD/AOD ,RVEDD ,RVEDL ,RVEDD/RVEDL increased ,while measurements of PAA T ,PAA T/PAET , T APSE decreased in the model group .T he changes of RVAWT ,PAD ,PAA T/PAET ,RVEDD in the model group appeared early in the second week in contrast to data before molding ( P <0 .05) . When comparing model group with NC group ,there were statistic differences of RVAWT ,PAAT/PAET as early as 2 weeks after modeling measuring (all P <0 .05) and the dramatic variance in the parameters of PAD/AOD ,PAAT , RVEDD ,RVEDD/RVEDL ,T APSE appeared in 4‐week observation . Correlation analysis suggested there were high‐degree correlations between PAA T ,PAA T/PAET and PASP ,PAM P ( for PASP : r = -0 .829 ,-0 .865 ,P< 0 .05 ; for PAM P : r = -0 .831 , -0 .842 , P < 0 .05 ) ,and moderate‐degree correlations between RVAWT ,PAD/AOD ,RVEDD ,RVEDD/RVEDL ,T APSE and PASP ,PAM P ( for PASP :|r|=0 .615-0 .786 , P <0 .05 ; for PAM P : r =0 .683-0 .799 , P <0 .05) .T he linear dependent equations were established as PASP = -169 .392 PAAT/PAET + 105 .092 ( r2 = 0 .748 , P = 0 .000 ) ,PASP = 49 .576 RVAWT+67 .314RVEDD/RVEDL -45 .198 ( r2 =0 .731 , P =0 .003) ,PAM P= -150 .664PAAT/PAET+88 .156 ( r2 =0 .709 , P = 0 .001 ) ,PAM P=37 .988RVAWT +82 .072RVEDD/RVEDL -50 .517 ( r2 =0 .794 , P = 0 .001 ) to represent the relationships between PASP or PAM P and PAAT/PAET or RVAWTcombined RVEDD/RVEDL . Conclusions Echocardiography can monitor changes in heart structure and hemodynamics .Ultrasonic parameters especially PAAT/PAET or RVAWT ,RVEDD/RVEDL could be used to estimate PASP or PAM P measured by catheterization .
RESUMO
Objective To identify the mechanisms of oral administered rapamycin on the prevention of restenosis after stent implantation with intravascular ultrasound (IVUS) and pathology.Methods Twenty-four New Zealand white rabbits underwent balloon-induced abdominal aortic wall injury and were given a diet of 1 % cholesterol for 8 weeks.Then,the rabbits were divided into three groups:the bare metal stent group(BMS group),the bare metal stent with oral rapamycin group(BMS + RAPA group) and the rapamycin eluting stent group(DES group).Rabbits in the RAPA and BMS + RAPA groups received a daily oral dose of rapamycin(0.5 mg/kg),whereas rabbits in the DES group received no drugs.All the rabbits were euthanized after the 4-week intervention.Serum lipids were measured.IVUS and pathologic studies were performed.The minimal luminal diameter (MLD),external elastic membrane (EEM) area,lumen area (LA),and plaque area(PA),plaque burden(PB) were measured.Mammalian target of rapamycin(mTOR) expression level was examined by immunohistochemistry.Results After the 4-week intervention,there was no significant difference of serum lipid levels among the three groups.IVUS showed that oral administration of rapamycin in the BMS + RAPA groups showed similar effects in reducing PA and PB as the DES group,which all were better than the BMS group.The BMS + RAPA and DES groups showed much more MLD and less lumen reduction,compared with the BMS group( P <0.05).Level of mTOR expression of the BMS + RAPA group and DES group was significantly lower than that of BMS group.Conclusions Oral administration of rapamycin demonstrates the same effect in the reduction of plaque burden and stent restenosis as the rapamycin eluting stent.Inhibition of mTOR by rapamycin involves in the stent restenosis.
RESUMO
ObjectiveTo elucidate the clinical application value of intravascular ultrasound(IVUS) in assessing intermediate lesions and the relationship between serum levels of fractalkine,CD36 and LP-PLA2and severity of coronary artery atherosclerosis.MethodsOne hundred and twenty patients with unstable angina underwent coronary angiography.Then the patients were divided into two groups:severe lesion group (lumen diameter stenosis greater than 70%,including 40 patients),and the intermediate lesion group lumen diameter stenosis(50%~70%,80 patients).IVUS were performed in all patients to analysis the coronary lesions.Concentrations of CD36,fractalkine and LP-PLA2 were measured by means of ELISA.Results IVUS found that 74% intermediate lesion patients had soft lipid plaques,while 48% severe lesion patients had lipid plaques ( P<0.01 ).Patients with severe lesion had larger plaque burden and vascular remodeling index than those of patients with intermediate lesions(P<0.05~0.01).There were 59 patients(74%) in the intermediate lesion group underwent PCI.IVUS also found the PCI patients had larger plaque burden and vascular remodeling index.Concentration of CD36 was significantly higher in severe lesion group than that of intermediate lesion group (P<0.05).ConclusionsIVUS could further clarify the characteristics of the intermediate and severe lesions,and provide guidance for PCI treatment.Plasma CD36 level could be used to predict pathological severity of coronary atherosclerosis.
RESUMO
Objective To investigate the feasibility of gene modification of peripheral blood derived endothelial progenitor cells(EPCs).Methods The rabbit mononuclear cells were collected from rabbit peripheral blood and cultured.The uptaking test of DiI-Ac-LDL was directly visualized with fluorescent microscopy,the immunofluorescence analysis was performed to detect the expression of surface marker.And the human tissue kallikrein(HTK)gene was amplified with PCR,and inserted into pEGFP-N3 vector.EPCs were transfected with the constructed plasmid by means of lipidosome,and the HTK-EGFP fused protein was visualized directly with fluorescent microscopy,and the expression of HTK was detected by RT-PCR and ELISA.Results After 5~6 days of culture,spindle-shaped attached cells clustered together,and cobblestone-like cell layer appeared after 15 days.Cells were positive of uptaking DiI-Ac-LDL and expressing vWF and CD133 related antigen.Plasmids were correctly formed and expressed in the rabbit EPCs.The fused protein had activity of both HTK and EGFP.Conclusion The HTK gene modified EPCs is potential in the treatment of artery injury and endothelial dysfunction.
RESUMO
OBJECTIVE: To investigate the protective effect of berberine on CCl4-induced acute liver injury in mice.METHODS: Kunming mice were included and equally divided into 6 groups: normal group,model group,berberine groups(40,20,10 mg?kg-1).After intragastric administration of corresponding drugs for 5 consecutive days,the mice were intraperitoneally injected with CCl4(10 mL?kg-1) to establish liver injury mice model.Alanine transaminase(ALT) and aspartate transaminase(AST) in serum,activities of superoxidase(SOD) and malondialdehyde(MDA) content in liver homogenate were measured.RESULTS: In Berberine-treated groups compared the model group,serum ALT level and AST activity decreased significantly(P