Electrogenic proton/L-glutamate symport in isolated asparagus sprengeri mesophyll cell

Medium' alkaliniiation occurred -lipon the addition of L-Glu to mechanically isolated Asparagus sprenger-i mesophyll cells suspended in 1 mM CaS04. Alkalinization resulted from the coupled entry of H+ and L-Glu anion into the cells. This H+ IL-Glu symport did not stimulate K+ efflux. K+ efflux has been observed during H~ lamino acid symport in other systems. The stimulation of K+ efflux by proton coupled symport is regarded as an indicator of a plasma membrane depolarizing electrogenic symport process. H+ IL-Glu symport in Asparagus sprengerimesophyl1 cells was investigated to determine whether or not the process was electrogenic. The rate of uptake of 0.25 11M 3H-MTPP+ ( Methyltriphenylphosphonium, methyl-3H ) is a probe for monitoring changes in the membrane potential. 3HMTPP+ uptake was reduced by K+ or CCCP, agents known to depolarize the membrane potential. Uptake of 3H-MTPP+ was also inhibited by L-Glu but not by D-Glu. Conversely, 10 mM external MTPP+ inhibited the uptake of 14C-U-LGlu. Simultaneous measurements of the rates of 14C-U-L-Glu uptake and L-Glu dependent H+ influx showed that the molar stoichiometry of H+ IL-Glu symport was 2 to 1. K+ or Na+ stimulated H+ efflux was completely inhibited by DCCD, DES, oligomycin and antimycin reagents which inhibit ATP driven H+ efflux. The H+ efflux \Vas also stimulate.d by the weak acids, butyric acid and acetic acid, which are known fo-aCidify the cytoplasm. This weak acid stimulated H+ efflux was also completely inhibited by oligomycin. It was calculated that net L-Glu dependent H+ influx increased by 100% in the presence of oligomycin and that despite net medium alkalinization H+ IL-Glu symport stimulates ATP dependent H+ efflux. 11 The data presented in this study indicate that H+ IL-Glu symport is electrogenic. The data also show that ATP dependent Ht efflux rather than K+ efflux is the- process compensating for thi~ electrogenic H+ IL-Glu symport

Expression, Purification and Activity Study of Amuc_1100

Objective: To construct prokaryotic expression vector of Amuc_1100 gene, the ELP (ELSTIN-LIKE PROTEIN) is used as purification label to express fusion with the target protein and detect the biological activity of recombinant protein at cell level and animal level. Methods: the recombinant plasmid pET28a-Amuc_1100-ELP is designed and synthesized, and transformed into e. coli competent cell bl21 (de3) to induce expression. The recombinant egg was isolated and purified by the reversible phase change cycling (ITC) characteristic of ELP10 white. At the cellular level, PBMCs cells from mice were extracted to detect the expression level of IL-10. At the animal level, obese mice induced by gastric gavage with high fat detected the improvement effect of the protein on mouse metabolism. Results: The recombinant protein with the expected molecular weight of 60 kDa was expressed by E.coli expression system. After circulating through ITC, the recombinant protein with high purity was obtained. The protein increased the expression level of IL-10 in PBMCs cells, and significantly improved the obesity and metabolic disorders induced by high-fat diet in mice. Conclusion: The recombinant protein expression plasmid pET28a-Amuc_1100-ELP was successfully constructed. After expression and purification, the recombinant protein expression plasmid has high purity and has 15 biologically active recombinant protein. This study laid a foundation for the industrial production and clinical application of Amuc_1100

Detecting multiple cracks in beams using hierarchical genetic algorithms

This study deals with a method to identify multiple cracks in a beam. The novelty of this study is the use of a hierarchical genetic algorithm to detect the number, location, and the extent of multiple cracks. To demonstrate the feasibility of the present method, this algorithm is applied to the identification of double or triple cracks in a beam as well as four cracks. The detected crack locations and sizes are in excellent agreement with the actual ones. The numerical simulation reveal the HGA substantially reduces the total number of FE computation required and they are many orders smaller compared to conventional GA. The results also demonstrate the advantages of HGA from the viewpoints of its ability to avoid premature convergence

Face hallucination under an image decomposition perspective

In this paper we propose to convert the task of face hallucination into an image decomposition problem, and thenuse the morphological component analysis (MCA) for hallucinating a single face image, based on a novel three-stepframework. Firstly, a low-resolution input image is up-sampled by interpolation. Then, the MCA is employed to decompose the interpolated image into a high-resolution image and an unsharp masking, as MCA can properly decompose a signal into special parts according to typical dictionaries. Finally, a residue compensation, which is based on the neighbour reconstruction of patches, is performed to enhance the facial details. The proposed method can effectively exploit the facial properties for face hallucination under the image decomposition perspective. Experimental results demonstrate the effectiveness of our method, in terms of the visual quality of the hallucinated face images

Analytic study on the foundation of shaker based on AIR spring

In view of the limitation of the traditional installation method of the shaker placed on the floor structure, a method of foundation isolation based on the AIR spring is proposed. According to the dynamic characteristics of the AIR spring, the relationship between the natural frequency and the parameters, such as the air pressure and the weight of the load, are analyzed. In order to evaluate the coupling properties between the vibration isolation system and the vibration test system, the factors affecting the vibration isolation transfer function of the system and the response of the foundation under vibration excitation were analyzed. Test results revealed that: it is feasible to adjust the natural frequency of system, to obtain the good isolation performance and stationary dynamic response, by reasonably choosing the structural parameters of the AIR spring and adjusting the internal inflation pressure of spring

Transcriptional up-regulation of relaxin-3 by Nur77 attenuates β-adrenergic agonist-induced apoptosis in cardiomyocytes.

The relaxin family peptides have been shown to exert several beneficial effects on the heart, including anti-apoptosis, anti-fibrosis, and anti-hypertrophy activity. Understanding their regulation might provide new opportunities for therapeutic interventions, but the molecular mechanism(s) coordinating relaxin expression in the heart remain largely obscured. Previous work demonstrated a role for the orphan nuclear receptor Nur77 in regulating cardiomyocyte apoptosis. We therefore investigated Nur77 in the hopes of identifying novel relaxin regulators. Quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) data indicated that ectopic expression of orphan nuclear receptor Nur77 markedly increased the expression of latexin-3 (RLN3), but not relaxin-1 (RLN1), in neonatal rat ventricular cardiomyocytes (NRVMs). Furthermore, we found that the -adrenergic agonist isoproterenol (ISO) markedly stimulated RLN3 expression, and this stimulation was significantly attenuated in Nur77 knockdown cardiomyocytes and Nur77 knockout hearts. We showed that Nur77 significantly increased RLN3 promoter activity via specific binding to the RLN3 promoter, as demonstrated by electrophoretic mobility shift assay (EMSA) and chromatin immuno-precipitation (ChIP) assays. Furthermore, we found that Nur77 overexpression potently inhibited ISO-induced cardiomyocyte apoptosis, whereas this protective effect was significantly attenuated in RLN3 knockdown cardiomyocytes, suggesting that Nur77-induced RLN3 expression is an important mediator for the suppression of cardiomyocyte apoptosis. These findings show that Nur77 regulates RLN3 expression, therefore suppressing apoptosis in the heart, and suggest that activation of Nur77 may represent a useful therapeutic strategy for inhibition of cardiac fibrosis and heart failure. © 2018 You et al

Intrinsic chemoresistance to gemcitabine is associated with constitutive and laminin-induced phosphorylation of FAK in pancreatic cancer cell lines

<p>Abstract</p> <p>Background</p> <p>One of the major reasons for poor prognosis of pancreatic cancer is its high resistance to currently available chemotherapeutic agents. In recent years, focal adhesion kinase (FAK), a central molecule in extracellular matrix (ECM)/integrin-mediated signaling, has been thought to be a key determinant of chemoresistance in cancer cells. In this study, we aimed to determine the roles of FAK phosphorylation in the intrinsic chemoresistance of pancreatic cancer cell lines.</p> <p>Results</p> <p>Our results showed that, the level of constitutive phosphorylation of FAK at Tyr397 correlated with the extent of intrinsic resistance to Gemcitabine (Gem) in four pancreatic cancer cell lines. Moreover, in Panc-1 cells, which had high expression of pFAK, specific inhibition of constitutive FAK phosphorylation by either RNAi or FRNK overexpression decreased the phosphorylation of Akt, reduced the levels of survivin expression and Bad phosphorylation at Ser136 and increased Gem-induced cytotoxicity and apoptosis. However, in AsPC-1 cells with a low level of pFAK, neither FAK RNAi nor FRNK overexpression affected Gem-induced cell apoptosis. We further found that laminin (LN) induced FAK and Akt phosphorylation in a time-dependent manner, increased the levels of survivin and pBad (pS136) and decreased Gem-induced cytotoxicity and apoptosis in AsPC-1 cells; Specific inhibition of LN-induced FAK phosphorylation by either FAK RNAi or FRNK overexpression suppressed the effects of LN on AsPC-1 cells. Moreover, inhibition of constitutive FAK phosphorylation in Panc-1 cells and LN-induced FAK phosphorylation in AsPC-1 cells by a novel and more specific FAK phosphorylation inhibitor PF-573,228 showed similar results with those of FAK phosphorylation inhibition by FAK RNAi or FRNK overexpression.</p> <p>Conclusions</p> <p>In conclusion, our research demonstrates for the first time that both constitutive and LN-induced FAK phosphorylation contribute to increased intrinsic chemoresistance to Gem in pancreatic cancer cell lines and these effects are partly due to the regulation of Akt and Bad phosphorylation and survivin expression. Development of selective FAK phosphorylation inhibitors may be a promising way to enhance chemosensitivity in pancreatic cancer.</p

Efficacy and safety of post-auricular injection of methylprednisolone sodium succinate and lidocaine in the treatment of acute tinnitus, and its effect on sleep quality

Purpose: To study the efficacy and safety of post-auricular injection of methylprednisolone sodium succinate plus lidocaine in the treatment of acute tinnitus, and its effect on sleep quality.Methods: Eighty acute tinnitus patients admitted to Nanfang Hospital, Southern Medical University, Guangzhou, China from January 2020 to June 2021, served as subjects for this retrospective analysis. The patients were equally assigned to a reference group given postauricular injection of lidocaine, and a research group treated with post-auricular injection of methylprednisolone sodium succinate in combination with lidocaine. Treatment efficacy values in the two groups of patients were determined and compared.Results: Total treatment effectiveness values in patients in the research group after one course of treatment, and at three months post-treatment, were significantly higher than the corresponding values in the reference group (p &lt; 0.05). After treatment, the two groups had markedly improved Tinnitus Handicap Inventory (THI) scores, although patients in the research group had lower scores than those in reference group (p &lt; 0.05). There were significant decreases in post-treatment pure tone threshold and Pittsburgh sleep quality index (PSQI) in the two groups of patients, with lower values in the research group than in the reference group (p &lt; 0.05). There were no obvious adverse drug reactions during treatment and during 3-month follow-up period.Conclusion: Post-auricular injection of methylprednisolone sodium succinate and lidocaine effectively improved the clinical efficacy and the sleep quality of acute tinnitus patients. It is a simple and highly safe operation which merits clinical application

Vibration Damping of Carbon Nanotube Assembly Materials

Vibration reduction is of great importance in various engineering applications, and a material that exhibits good vibration damping along with high strength and modulus has become more and more vital. Owing to the superior mechanical property of carbon nanotube (CNT), new types of vibration damping material can be developed. This paper presents recent advancements, including our progresses, in the development of high-damping macroscopic CNT assembly materials, such as forests, gels, films, and fibers. In these assemblies, structural deformation of CNTs, zipping and unzipping at CNT connection nodes, strengthening and welding of the nodes, and sliding between CNTs or CNT bundles are playing important roles in determining the viscoelasticity, and elasticity as well. Towards the damping enhancement, strategies for micro-structure and interface design are also discussed