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1.
The difference between human normal and carcinoma lung cells was studied with regard to the protein expression level and localization of the cadherin/catenin/actin complex. Results demonstrated that normal lung cell RF expressed high levels of N-cadherin, β-catenin, α-catenin. These 3 proteins were colocalized at AJs and their submembrane adhesion plaques where they link the Rho-phalloidin-positive actin stress fibers, indicating the existence of N-cadherin/catenin/actin complexes at the AJs. Aberrant expression of AJ proteins and the actin cytoskelecton in carcinoma PG cells was observed: (1) inhibition of N-cadherin and to a degree of inhibition of α-catenin protein expression; (2) varied protein modification of β-catenin in cytoplasm soluble fraction and altered distribution of immunofluorescence: majorly in the cytoplasm and minorly on the membrane; (3) disassembly of actin stress fibers and formation of actin bodies in the cytoplasm. The data suggest that inhibited expression of AJ proteins is correlated with the disruption of the AJ complexes and the actin cytoskeleton in carcinoma PG cells, and responsible for its metastasis behaviors.  相似文献   

2.
NMDA receptor (NMDA-R) in the amygdala complex is critical for both long-term potentiation (LTP) and formation of conditioned fear memory. It is reported that activation of β-adrenoceptors (β-AR) in the amygdala facilitates LTP and enhances memory consolidation. The present study examined the regulatory effect of β-AR activation on NMDA-R mediated current in pyramidal cells of the basolateral nucleus of amygdala (BLA), using whole-cell recording technique. Bath application of the β-AR agonist isoproterenol enhanced NMDA-induced current, and this facilitatory effect was blocked by co-administered propranolol, a β-AR antagonist. The facilitatory effect of isoproterenol on NMDA-induced current could not be induced when the protein kinase A (PKA) inhibitor Rp-cAMPs was added in electrode internal solution.The present results suggest that β-AR activation in the BLA could modulate NMDA-R activity directly and positively, probably via PKA.  相似文献   

3.
To assess the remolding ability of repaired bone in hydroxyapatite (HA) and β-calcium phosphate (β-TCP) scaffold, two 75% porosity bioceramics with the same three-dimensional geometry were implanted into femoral condyles of rabbits. Histological and micro-computed tomography (micro-CT) results demonstrated abundant new bone formation in the porous HA scaffold along with indistinctive scaffold degradation. Results also indicated that scaffold resorption in the β-TCP group, which was followed by a replacement with newly formed bone, was significantly higher than that in the HA group. The crosslinking trabeculae remodeled from the mixtures of the newly formed bone and β-TCP scaffold remnants might be helpful to promoting even loading and reducing stress. The bone remodeling pattern resulted from bone formation and scaffold resorption was significantly different for the two bioceramics. The results demonstrated that the 75% porous β-TCP was more suitable for new bone remodification than HA scaffold.  相似文献   

4.
Appressorium formation is an important event in establishing a successful interaction between the rice blast fungus, Magnaporthe oryzae, and its host plant, rice. An understanding of molecular events occurring in appressorium differentiation will give new strategies to control rice blast. A quick and reliable method to extract total RNA from appressorium is essential for studying gene expression during appressorium formation and its mechanism. We found that duplicate film is an efficient substratum for appressorium formation, even when inoculated with high density conidia. When inoculated with conidia at 1 × 106 ml^-1, the percentages of conidium germination and appressorium formation were (97.98±0.67)% and (97.88±0.45)%, respectively. We applied Trizol before appressorium collection for total RNA isolation, and as much as 113.6 lag total RNA was isolated from the mature appressoria at 24 h after inoculation. Functional analysis of two genes, MNH6 and MgATG1, isolated from the cDNA subtractive library, revealed that the quantity of RNA was good enough to construct a cDNA (complementary DNA) library or a cDNA subtractive library. This method may be also applicable for the appressorium RNA isolation of other pathogenic fungi in which conidia differentiate into appressoria in the early stages of host infection.  相似文献   

5.
Inclusion complex of Orange II with β-Cyclodextrin (β-CD) and the anti-photolysis effect under UV-light were investigated. The molar ratio of inclusion complex of β-Cyclodextrin and Orange Ⅱ is 1∶1. The formation constant K=1.236×103 L/mol was determined by the UV and Fluorescence spectra respectively, which was quite in accordance with the calculation with a modified Benesi-Hildbrand equation. The inclusion complex was characterized by the IR spectra and the molar ratio of inclusion complex is 1∶1 too. The formation constant K=1.266×103 L/mol was determined by 1 H NMR analysis and was nearly the same by UV and fluorescence spectra. The photocatalytic decolorization rate of Orange Ⅱ solutions containing β-CD and TiO2 was smaller by 51.9% than that of the Orange Ⅱ solutions only containing TiO2, while in the case of direct photolysis of Orange Ⅱ solutions, β-CD can lower the photolysis rate by 48.1% under UV-light. This result indicates β-CD can inhibit the photolysis and photocatalytic decolorization of Orange Ⅱ under UV-light. The β-CD inclusion complex was found to be persistent to UV-light photolysis.  相似文献   

6.
A novel type of circular single-stranded satellite DNA, known as DNAβ, was recently characterized and demonstrated to be associated with monopartite begomoviruses. DNAβ was essential for induction of characteristic symptoms in plants. DNAβ has three structural features: an 115 bp highly conserved region, tiC/gene and A-Rich region. The in-frame ATG mutation of βC1 gene of Tomato yellow leaf curl China virus isolate Y10 (TYLCCNV-TY10) DNAβ demonstrated that βC1 gene is required for leaf curl symptom. Here, the function of A-Rich region in TYLCCNV-Y10 DNAβ was identified. When A-Rich region was deleted, the A-Rich deleted mutant was still capable of replication and systemic infection in plant, indicating that A-Rich region is not required for trans-replication of DNAβ. The immunotrapping-PCR demonstrated that A-Rich deleted mutant could be encapsidated in the coat protein encoded by TYLCCNV-Y10 DNA-A, suggesting that A-Rich region is not related with DNAβ encapsidation. However, the A-Rich region deleted mutant caused milder symptom.  相似文献   

7.
Efficient thickening of tailings is a prerequisite for the metal mine tailings backfill and surface disposal operation. The effective collision of ultrafine tailings particles in suspension with flocculant molecules is essential for flocs aggregates formation and settling. Unreasonable feeding speed and flocculant adding method will lead to the failure of effective dispersion of flocculant and high particle content in thickener overflow. In this work, the effect of turbulence intensity and flocc...  相似文献   

8.
9.
This study aimed at exploring the effect of surface morphology of dense phosphate calcimn (Ca-P) ceramics upon the formation of bone-like apatite in static or dynamic simulated body fluid (SBF). Dense and sandblasted calcium phosphate ceramics were immersed into dynamic SBF flowing at normal physiological speed of body fluid of skeletal muscle. The changes were characterized using SEM, XPS, IR and XRD. Changes can be observed after the sandblasted surface of dense calcium phosphate ceramics had been immersed in SBF for 14 days. XPS analysis results showed that the flake-like structure was composed of Ca, P, C, O; IR analysis result of surface structure of samples showed that there were specific peaks for CO3^2-; XRD results indicated the decrease in crystallinity and the increase in amorphous structure. The rough surface was advantageous for the formation of bone-like apatite. Increasing the Ca^2+, HPO4^2- concentration of SBF could also enhance the bonelike apatite formation. All the results demonstrated that local concentration is a key factor affecting nucleation.  相似文献   

10.
Dynamically tracking hundreds of individual pits is essential to determine whether there exist "hot spots" for the formation of clathrin-coated pits or if the pits formed randomly on the plasma membrane. We propose an automated approach to detect these particles based on an improved á trous wavelet transform decomposition with automatic threshold selection and post processing solution, and to track the dynamic process with a greedy algorithm. The results indicate that the detection method can successfully detect most particles in an image with accuracy of 98.61% and 97.65% for adaptor and clathrin images, respectively, and that the tracking algorithm can resolve merging and splitting issues encountered when analyzing dynamic, live-cell images of clathrin assemblies.  相似文献   

11.
Intrusion detection system can make effective alarm for illegality of network users, which is absolutely necessarily and important to build security environment of communication base service. According to the principle that the number of network traffic can affect the degree of self-similar traffic, the paper investigates the variety of self-similarity resulted from unconventional network traffic. A network traffic model based on normal behaviors of user is proposed and the Hurst parameter of this model can be calculated. By comparing the Hurst parameter of normal traffic and the self-similar parameter, we can judge whether the network is normal or not and alarm in time.  相似文献   

12.
Information on palaeoocean and palaeoclimate can be recorded in foraminifera, and formation ages of the fo- raminifera are nevertheless essential for such study of pa- laeoenvironment. The growth rate of seamount ferroman- ganese crusts is normally very l…  相似文献   

13.
Microsporogenesis in flowering plants plays important roles in sexual reproduction. It has been reported that DEFECTIVE IN EXINE FORMATION1 (DEX1) is essential for exine pattern formation in Arabidopsis thaliana. However, the functions of DEX1 in regulating microspore development are largely not understood. In this study, we show that DEX1 is strongly expressed in the tapetum by using RNA in situ hybridization. dex1 microspores were degenerated and aborted after release from the tetrads. The callose wall in tetrads was thinner in the dex1 mutant than in the wild type, suggesting that DEX1 affects callose formation at the tetrad stage during anther development. RT-PCR and real-time PCR analyses showed that CalS5, which plays an important role in callose synthesis during microspore development, was greatly down-regulated in dex1 plants. DEX1 encodes a membrane protein with one transmembrane domain, one intracellular domain and one extracellular domain. Collectively, our results demonstrate that DEX1 is essential for microspore development, possibly by regulating the expression of CalS5.  相似文献   

14.
Angiogenesis is very important for many physiological and pathological processes. However, the molecular mechanisms of angiogenesis are unclear. To elucidate the molecular mechanisms of angiogenesis and to develop treatments for "angiogenesis-dependent" diseases, it is essential to establish a suitable in vitro angiogenesis model. In this study, we created a novel in vitro angiogenesis model based on a microfluidic device. Our model provides an in vivo-like microenvironment for endothelial cells (ECs) cultures and monitors the response of ECs to changes in their microenvironment in real time. To evaluate the potential of this microfluidic device for researching angiogenesis, the effects of pro-angiogenic factors on ECs proliferation, migration and tube-like structure formation were investigated. Our results showed the proliferation rate of ECs in 3D matrix was significantly promoted by the pro-angiogenic factors (with an increase of 59.12%). With the stimulation of pro-angiogenic factors gradients, ECs directionally migrated into the Matrigel from low concentrations to high concentrations and consequently formed multi-cell chords and tube-like structures. These results suggest that the device can provide a suitable platform for elucidating the mechanisms of angiogenesis and for screening pro-angiogenic or anti-angiogenic drugs for "angiogenesis-dependent" diseases.  相似文献   

15.
It was assumed that the homogeneous dehydrogenation of CiHg occurred in the gas phase was independent of the presence of catalysts and this is applicable to the oxidative dehydrogenation of ethane with CO2 over CeO2 . On the basis of this assumption, a method was developed to analyze the contribution of C2rtj formation from heterogeneous catalysis. In this study, ceria was found to be active and selective for the oxidative dehydrogenation of ethane with CO2 and the selectivity to C, H4 was above 60 % and the actual contribution for C, H4 formation from heterogeneous catalysis was about 55%— 75% in the range of 953—993 K.  相似文献   

16.
A predominance area diagram for the Zr-Si-C-O system at 1773 K was plotted according to correlative thermodynamic data. β-SiC/ZrO2 composites were prepared based on the phase diagram by carbothermal reduction of zircon (ZrSiO4) in argon atmosphere. Zircon and carbon black were mixed according to the C/ZrSiO4 mass ratio of 0.2, and with 0, 1wt% and 2wt% extra addition of La2O3. Phase evolution of the mixture was investigated at 1723-1803 K by X-ray powder diffraction, and the microstructure of the product prepared at 1803 K for 4 h was examined by scanning electronic microscope. The results show that the decomposition of ZrSiO4 and the formation of β-SIC can be promoted by increasing the heating temperature and adding La2O3. The β-SiC/ZrO2 composites can be prepared at 1803 K for 4 h in a mixture of zircon, carbon black and La2O3, and the contents of β-SIC and m-ZrO2 in the product sample with 2wt% La2O3 reach the highest values of 10.8wt% and 89.2wt%, respectively. The crystal size of the products is about 200 nm.  相似文献   

17.
The formation mechanisms of the mega-dunes and lakes in the hinterland of Badain Jaran Desert,China,is the focus of extensive academic research in the field of geoscience,and an often debated topic is whether atmospheric precipitation on the mega-dune can infiltrate to recharge groundwater.In the present study,the probability distribution functions and the return period analysis of extreme daily precipitation based on long-term precipitation records for the southern margin of Badain Jaran Desert and 2-year observation of hinterland precipitation were used to classify precipitation in the desert region.The data of automatic weather station and eddy covariance system in the desert hinterland were used to analyze evaporation on the mega-dune surface after various rain events.The results showed that the rain events in the desert could be divided into three categories.The first is conventional precipitation(CP),which is below 5 mm,accounting for roughly 90%of all rain events in the desert.The second and third categories are ordinary annual maximum(OAM)and extreme precipitation(EP),in which precipitation is roughly 20 mm and more than 40 mm,respectively.The atmospheric precipitation of CP and OAM evaporated from the megadune surface in 1–3 days and 3–4 weeks,respectively.Following an EP event,the mega-dune evaporation was negatively influenced by the upper dry sand layer,and a lengthy period was required for its complete removal.The accumulative evaporation and accumulative precipitation of all three types of rain events indicated that local atmospheric precipitation had no significant contribution to recharging the groundwater system in the hinterland of Badain Jaran Desert.This research will benefit comprehensive elucidation of the formation mechanism of lakes in the hinterland of Badain Jaran Desert.  相似文献   

18.
Electrospinning is a well-known process for producing submicrometer fibers, which have wide applications in many fields, especially in tissue engineering scaffolds and drug-delivery systems. This paper presents the formation of drug-loaded electrospun twin fibers. The correlations between the twin fiber formation and the polymer materials or the loaded drugs were studied by using poly(l-lactide) and poly(l-lactide-co-glycolide) as electrospinning materials, and rifampin and paclitaxel as loaded drugs. Scanning electron microscopy showed that the formation of twin fibers is significantly affected by the loaded drug but not the polymer material. A possible reason for twin fiber formation was analyzed.  相似文献   

19.
The internal cracks in continuously cast slabs are attributed to the excessive tensile strain occurring at the solidifying front during the continuous casting process. Based on the understanding, a model for diagnosing the formation of the internal cracks was established, in which the strains at the solidifying front caused by bulging, straightening or unbending, and roll misalignment were calculated and compared with a critical strain value to estimate whether the internal cracks form. Moreover, the established model was applied to a real slab caster to reveal the distribution of the strains in casting direction and its effect on the internal cracks. It was proved that the model was reliable and useful for optimizing the operation of continuous casting.  相似文献   

20.
The origin of dolomite has been hotly debated. There is still a lack of petrological evidence and theoretical support for the formation of primary dolomite in geological history because dolomite cannot be synthesized under normal laboratory conditions. Wright experimented  相似文献   

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