Dual-mode adaptive-SVD ghost imaging

In this paper, we present a dual-mode adaptive singular value decomposition ghost imaging (A-SVD GI), which can be easily switched between the modes of imaging and edge detection. It can adaptively localize the foreground pixels via a threshold selection method. Then only the foreground region is illuminated by the singular value decomposition (SVD) - based patterns, consequently retrieving high-quality images with fewer sampling ratios. By changing the selecting range of foreground pixels, the A-SVD GI can be switched to the mode of edge detection to directly reveal the edge of objects, without needing the original image. We investigate the performance of these two modes through both numerical simulations and experiments. We also develop a single-round scheme to halve measurement numbers in experiments, instead of separately illuminating positive and negative patterns in traditional methods. The binarized SVD patterns, generated by the spatial dithering method, are modulated by a digital micromirror device (DMD) to speed up the data acquisition. This dual-mode A-SVD GI can be applied in various applications, such as remote sensing or target recognition, and could be further extended for multi-modality functional imaging/detection

Bi-directional Mendelian randomization analysis provides evidence for the causal involvement of dysregulation of CXCL9, CCL11 and CASP8 in the pathogenesis of ulcerative colitis

Background and Aims Systemic inflammation is well recognised to be associated with ulcerative colitis [UC], but whether these effects are causal or consequential remains unclear. We aimed to define potential causal relationship of cytokine dysregulation with different tiers of evidence. Methods We first synthesised serum proteomic profiling data from two multicentred observational studies, in which a panel of systemic inflammatory proteins was analysed to examine their associations with UC risk. To further dissect observed associations, we then performed a bidirectional two-sample Mendelian randomisation [TSMR] analysis from both forward and reverse directions using five genome-wide association study [GWAS] summary level data for serum proteomic profiles and the largest GWAS of 28 738 European-ancestry individuals for UC risk. Results Pooled analysis of serum proteomic data identified 14 proteins to be associated with the risk of UC. Forward MR analysis using only cis-acting protein quantitative trait loci [cis-pQTLs] or trans-pQTLs further validated causal associations of two chemokines and the increased risk of UC: C-X-C motif chemokine ligand 9 [CXCL9] [OR 1.45, 95% CI 1.08, 1.95, p = 0.012] and C-C motif chemokine ligand 11 [CCL11] [OR 1.14, 95% CI 1.09, 1.18, p = 3.89 x 10(-10)]. Using both cis- and trans-acting pQTLs, an association of caspase-8 [CASP8] [OR 1.04, 95% CI 1.03, 1.05, p = 7.63 x 10(-19)] was additionally identified. Reverse MR did not find any influence of genetic predisposition to UC on any of these three inflammation proteins. Conclusion Pre-existing elevated levels of CXCL9, CCL11 and CASP8 may play a role in the pathogenesis of UC

Influence of grain discharge rate on the normal force of arch

The arch stress of grain particles during the discharge of the silo is very important to the safety of the silo. At present, most silos adopt the standard discharge port size. To improve the discharge efficiency, it is generally achieved by changing the angle of the discharge port. In this article, an improved silo model is used to study the discharge experiments in the silo with five inclination angles of the discharge port, and analyze the normal force distribution of the wheat grains at the arch, comparing the normal force distribution under five different discharge rates. From the results given, when the angle of the discharge port is 45°, the area where the normal force among particles is larger is wider. At other flow rates, increasing the flow rate can shorten the arching period. During the arching cycle, the normal force among particles in the center area of the silo at the same height is smaller than at the silo wall and is negatively correlated with the discharge rate. In addition, the normal force on the silo wall gradually decreases with the increase in the discharge rate

A Flow Velocity Measurement Method Based on a PVDF Piezoelectric Sensor

To measure the flow velocity of a fluid without affecting its motion state, a method was proposed based on a polyvinylidene fluoride (PVDF) piezoelectric film sensor. A self-made PVDF piezoelectric sensor placed parallel with the flow direction was used to measure the flow velocity. First, the piezoelectric characteristics of PVDF were obtained theoretically. Next, the relationship between flow velocity and sound pressure was verified numerically. Finally, the relationship between flow velocity and the electrical output of the PVDF piezoelectric film was obtained experimentally. In conclusion, the proposed method was shown to be reliable and effective

Separating boundary potential changes at thin solid contact ion transfer voltammetric membrane electrodes

Thin ion-selective membrane films deposited on solid electrode substrate are useful tools to study ion transfer processes. This is because the experimental conditions may be chosen such that diffusion processes within the membrane and contacting aqueous solution are not rate limiting. In an ideal case, therefore, equilibrium considerations may be used to describe the resulting ion transfer voltammograms. For example, the electrochemical oxidation of an electrically neutral redox molecule in the membrane results in a cationic oxidized form. To preserve electroneutrality, a cation is transferred out of the membrane into solution, freeing the cation-exchanger of the membrane to become the counterion of the oxidized redox molecule. This work describes a model system that agrees well with thermodynamic theory, using the lipophilic (1-dodecyl-1H-1,2,3-triazol-4-yl)ferrocene as redox molecule and a monovalent reference cation for ion transfer. The full peak width at half maximum was found as 0.110 V, in agreement with theory, and with peak current proportional to scan rate supporting thin layer behavior. The charge passed during the voltammetric scan was related to ion-exchanger concentration available for ion extraction as a function of potential. Subtraction of the ion transfer potential using the reference ion from the experimental one for each charge increment gave the potential change for the electrochemical ion-to-electron transducer. In one application, the potential change of the polymeric transducing layer poly(3-octylthiophene) (POT) film upon electrochemical oxidation within the membrane was characterized. A non-linear potential–charge curve was observed, in contrast to earlier assumptions

Selective Molecular Recognition of Low Density Lipoprotein Based on β-Cyclodextrin Coated Electrochemical Biosensor

The excess of low-density lipoprotein (LDL) strongly promotes the accumulation of cholesterol on the arterial wall, which can easily lead to the atherosclerotic cardiovascular diseases (ACDs). It is a challenge on how to recognize and quantify the LDL with a simple and sensitive analytical technology. Herein, β-cyclodextrins (β-CDs), acting as molecular receptors, can bind with LDL to form stable inclusion complexes via the multiple interactions, including electrostatic, van der Waals forces, hydrogen bonding and hydrophobic interactions. With the combination of gold nanoparticles (Au NPs) and β-CDs, we developed an electrochemical sensor providing an excellent molecular recognition and sensing performance towards LDL detection. The LDL dynamic adsorption behavior on the surface of the β-CD-Au electrode was explored by electrochemical impedance spectroscopy (EIS), displaying that the electron-transfer resistance (Ret) values were proportional to the LDL (positively charged apolipoprotein B-100) concentrations. The β-CD-Au modified sensor exhibited a high selectivity and sensitivity (978 kΩ·µM−1) toward LDL, especially in ultra-low concentrations compared with the common interferers HDL and HSA. Due to its excellent molecular recognition performance, β-CD-Au can be used as a sensing material to monitor LDL in human blood for preventing ACDs in the future