Detecting Majorana fermions by nonlocal entanglement between quantum dots

Nonlocal entanglement between two quantum dots can be generated through Majorana fermions. The two Majorana fermions at the ends of an one-dimensional topological superconductor form a nonlocal fermion level, coupling to the occupation states of two quantum dots put close to the two ends, and the entire system will come into an entangled state. After introducing a charging energy by a capacitor, entanglement of the entire system can manifest itself through the nonlocal entanglement between the two quantum dots. That is, when measuring the electron occupations of the quantum dots, the measurement result of one quantum dot will influence the measurement result of the other quantum dot. This nonlocal entanglement between the two quantum dots is a strong evidence of the nonlocal nature of the fermion level constructed by two Majorana fermions.Comment: 4 pages, 4 figure

Numerical optimization of vibration acceleration transmissibility for seat suspension system in vehicles

The parallel mechanism was adopted as seat suspension system in this paper. And the active joints with damping springs as the reduction vibration actuator, the reduction vibration seat model with 3-PRPS parallel mechanism which had six degree of freedom was established. With position of the mechanism as the premise, stability indexes of the reduction vibration seat in motion were proposed. As a result, the task space of the moving platform was obtained according to the inverse solution of the mechanism position. To reduce vibration effectively, velocity matrix of branched chain was built by means of vector method. The structural parameters were obtained by the numerical computation to improve the reduction vibration space and flexibility. Based on the above analysis, the simulation model can be obtained. In order to verify the reliability of the simulation model, the experiment of vibration acceleration transmissibility was conducted and the result was then compared with that of the numerical computation. Their results were consistent with each other. It indicated that the simulation model was reliable and could be used for the subsequent analysis. Then, influence factors of vibration acceleration transmissibility were researched based on the verified simulation model. In order to obtain a suspension system with better reduction vibration performance, making the maximum vibration acceleration transmissibility in the vertical and horizontal be minimal was set as the optimization objective. And the above influence factors were taken as the design variables. Finally, the ride comfort of vehicles was improved. Meanwhile, this research can also provide some references for the similar engineering problems

Numerical optimization of vibration acceleration transmissibility for seat suspension system in vehicles

The parallel mechanism was adopted as seat suspension system in this paper. And the active joints with damping springs as the reduction vibration actuator, the reduction vibration seat model with 3-PRPS parallel mechanism which had six degree of freedom was established. With position of the mechanism as the premise, stability indexes of the reduction vibration seat in motion were proposed. As a result, the task space of the moving platform was obtained according to the inverse solution of the mechanism position. To reduce vibration effectively, velocity matrix of branched chain was built by means of vector method. The structural parameters were obtained by the numerical computation to improve the reduction vibration space and flexibility. Based on the above analysis, the simulation model can be obtained. In order to verify the reliability of the simulation model, the experiment of vibration acceleration transmissibility was conducted and the result was then compared with that of the numerical computation. Their results were consistent with each other. It indicated that the simulation model was reliable and could be used for the subsequent analysis. Then, influence factors of vibration acceleration transmissibility were researched based on the verified simulation model. In order to obtain a suspension system with better reduction vibration performance, making the maximum vibration acceleration transmissibility in the vertical and horizontal be minimal was set as the optimization objective. And the above influence factors were taken as the design variables. Finally, the ride comfort of vehicles was improved. Meanwhile, this research can also provide some references for the similar engineering problems

Dietary saponins of sea cucumber alleviate orotic acid-induced fatty liver in rats via PPARα and SREBP-1c signaling

<p>Abstract</p> <p>Background</p> <p>Nonalcoholic fatty liver disease is the most common chronic liver disease in the world, and is becoming increasingly prevalent. Saponins of sea cucumber (SSC) are proven to exhibit various biological activities. Therefore, the present study was undertaken to examine the effect of saponins extracted from sea cucumber (Pearsonothuria graeffei) on the preventive activity of fatty liver in rats.</p> <p>Methods</p> <p>Male Wistar rats were randomly divided into five groups, including normal control group, fatty liver model group, SSC-treated group with SSC at levels of 0.01%, 0.03% and 0.05%. Model rats were established by administration with 1% orotic acid (OA). After the experiment period, serum total cholesterol (TC), triglyceride (TG), and hepatic lipid concentrations were determined. To search for a possible mechanism, we examined the changes of key enzymes and transcriptional factors involved in hepatic lipids biosynthesis, fatty acid β-oxidation.</p> <p>Results</p> <p>Both 0.03% and 0.05% SSC treatment alleviated hepatic steatosis and reduced serum TG and TC concentration significantly in OA fed rats. Hepatic lipogenic enzymes, such as fatty acid synthase (FAS), malic enzyme (ME), and glucose-6-phosphate dehydrogenase (G6PDH) activities were inhibited by SSC treatment. SSC also decreased the gene expression of FAS, ME, G6PDH and sterol-regulatory element binding protein (SREBP-1c). Otherwise, the rats feeding with SSC showed increased carnitine palmitoyl transferase (CPT) activity in the liver. Hepatic peroxisome proliferator-activated receptor (PPARα), together with its target gene CPT and acyl-CoA oxidase (ACO) mRNA expression were also upregulated by SSC.</p> <p>Conclusions</p> <p>According to our study, the lipids-lowering effect of dietary SSC may be partly associated with the enhancement of β-oxidation via PPARα activation. In addition, the inhibited SREBP-1c- mediated lipogenesis caused by SSC may also contribute to alleviating fatty liver.</p

The mechanism of dietary cholesterol effects on lipids metabolism in rats

<p>Abstract</p> <p>Background</p> <p>Cholesterol administration has been reported to influence hepatic lipid metabolism in rats. In the present study, the effect of dietary cholesterol on hepatic activity and mRNA expression of the enzymes involved in lipid metabolism were investigated. Fourteen male Wistar rats were randomly divided into 2 groups and fed 1% cholesterol or cholesterol free AIN76 diets for 4 weeks.</p> <p>Results</p> <p>The serum triglyceride and high density lipoprotein cholesterol levels were significantly decreased but the total cholesterol and non high density lipoprotein cholesterol levels were significantly increased in the cholesterol-fed rats compared with the control rats. And the concentrations of the hepatic total cholesterol and triglyceride increased about 4-fold and 20-fold separately by dietary cholesterol. The activities of hepatic malic enzyme, glucose-6-phosphate dehydrogenase, fatty acid synthase, phosphatidate phophatase and carnitine palmitoyl transferase were depressed by the cholesterol feeding (40%, 70%, 50%, 15% and 25% respectively). The results of mRNA expression showed that fatty acid synthase, carnitine palmitoyl transferase 1, carnitine palmitoyl transferase 2, and HMG-CoA reductase were down-regulated (35%, 30%, 50% and 25% respectively) and acyl-CoA: cholesterol acyltransferase and cholesterol 7α-hydroxylase were up regulated (1.6 and 6.5 folds) in liver by the cholesterol administration.</p> <p>Conclusions</p> <p>The dietary cholesterol increased the triglyceride accumulation in liver, but did not stimulate the activity and the gene expression of hepatic enzymes related to triglyceride and fatty acid biosynthesis.</p

Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis.

BACKGROUND: Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed. AIM: To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging. METHODS: This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young\u27s modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination. RESULTS: 2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC \u3e 0.7, P \u3c 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC \u3e 0.7, P \u3c 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P \u3e 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC \u3e 0.7, P \u3c 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P \u3c 0.05), whereas no significant differences were observed in other comparisons (P \u3e 0.05). CONCLUSION: Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution

Distinct fingerprints of charge density waves and electronic standing waves in ZrTe3_3

Experimental signatures of charge density waves (CDW) in high-temperature superconductors have evoked much recent interest, yet an alternative interpretation has been theoretically raised based on electronic standing waves resulting from quasiparticles scattering off impurities or defects, also known as Friedel oscillations (FO). Indeed the two phenomena are similar and related, posing a challenge to their experimental differentiation. Here we report a resonant X-ray diffraction study of ZrTe$_3$, a model CDW material. Near the CDW transition, we observe two independent diffraction signatures that arise concomitantly, only to become clearly separated in momentum while developing very different correlation lengths in the well-ordered state. Anomalously slow dynamics of mesoscopic ordered nanoregions are further found near the transition temperature, in spite of the expected strong thermal fluctuations. These observations reveal that a spatially-modulated CDW phase emerges out of a uniform electronic fluid via a process that is promoted by self-amplifying FO, and identify a viable experimental route to distinguish CDW and FO.Comment: 6 pages, 4 figures; supplementary information available upon reques