High-speed in vitro intensity diffraction tomography

We demonstrate a label-free, scan-free intensity diffraction tomography technique utilizing annular illumination (aIDT) to rapidly characterize large-volume three-dimensional (3-D) refractive index distributions in vitro. By optimally matching the illumination geometry to the microscope pupil, our technique reduces the data requirement by 60 times to achieve high-speed 10-Hz volume rates. Using eight intensity images, we recover volumes of ∼350 μm  ×  100 μm  ×  20  μm, with near diffraction-limited lateral resolution of   ∼  487  nm and axial resolution of   ∼  3.4  μm. The attained large volume rate and high-resolution enable 3-D quantitative phase imaging of complex living biological samples across multiple length scales. We demonstrate aIDT’s capabilities on unicellular diatom microalgae, epithelial buccal cell clusters with native bacteria, and live Caenorhabditis elegans specimens. Within these samples, we recover macroscale cellular structures, subcellular organelles, and dynamic micro-organism tissues with minimal motion artifacts. Quantifying such features has significant utility in oncology, immunology, and cellular pathophysiology, where these morphological features are evaluated for changes in the presence of disease, parasites, and new drug treatments. Finally, we simulate the aIDT system to highlight the accuracy and sensitivity of the proposed technique. aIDT shows promise as a powerful high-speed, label-free computational microscopy approach for applications where natural imaging is required to evaluate environmental effects on a sample in real time.https://arxiv.org/abs/1904.06004Accepted manuscrip

Resolution-enhanced intensity diffraction tomography in high numerical aperture label-free microscopy

We propose label-free and motion-free resolution-enhanced intensity diffraction tomography (reIDT) recovering the 3D complex refractive index distribution of an object. By combining an annular illumination strategy with a high numerical aperture (NA) condenser, we achieve near-diffraction-limited lateral resolution of 346 nm and axial resolution of 1.2  μm over 130 μm×130 μm×8 μm volume. Our annular pattern matches the system’s maximum NA to reduce the data requirement to 48 intensity frames. The reIDT system is directly built on a standard commercial microscope with a simple LED array source and condenser lens adds-on, and promises broad applications for natural biological imaging with minimal hardware modifications. To test the capabilities of our technique, we present the 3D complex refractive index reconstructions on an absorptive USAF resolution target and Henrietta Lacks (HeLa) and HT29 human cancer cells. Our work provides an important step in intensity-based diffraction tomography toward high-resolution imaging applications.https://www.osapublishing.org/prj/fulltext.cfm?uri=prj-8-12-1818&id=442609Published versio

Dual-Modal Hybrid Control for an Upper-Limb Rehabilitation Robot

The recovery treatment of motor dysfunction plays a crucial role in rehabilitation therapy. Rehabilitation robots are partially or fully replacing therapists in assisting patients in exercise by advantage of robot technologies. However, the rehabilitation training system is not yet intelligent enough to provide suitable exercise modes based on the exercise intentions of patients with different motor abilities. In this paper, a dual-modal hybrid self-switching control strategy (DHSS) is proposed to automatically determine the exercise mode of patients, i.e., passive and assistive exercise mode. In this strategy, the potential field method and the ADRC position control are employed to plan trajectories and assist patients’ training. Dual-modal self-switching rules based on the motor and impulse information of patients are presented to identify patients’ motor abilities. Finally, the DHSS assisted five subjects in performing the training with an average deviation error of less than 2 mm in both exercise modes. The experimental results demonstrate that the muscle activation of the subjects differed significantly in different modes. It also verifies that DHSS is reasonable and effective, which helps patients to train independently without therapists

Hardware Trojan Detection Using Effective Property-Checking Method

Hardware Trojans refer to additional logic maliciously implanted by attackers in integrated circuits (ICs). Because of the potential security threat of hardware Trojans, they have attracted extensive attention to security issues. As a formal verification method, property checking has been proved to be a powerful solution for hardware Trojan detection. However, existing property-checking methods are limited by the unity of security properties and the model explosion problem of formal models. The limitations above hinder the practical applications of these methods. To alleviate these challenges, we propose an effective property-checking method for hardware Trojan detection. Specifically, we establish the formal model based on the principle of finite state machine (FSM), and the method can alleviate the model explosion problem. For property writing, we extract the core behavior characteristics of hardware Trojans and then generate properties for the verification of certain types of hardware Trojans. Experimental results demonstrate that our approach is applicable to detect information leakage and denial of service (DoS) hardware Trojans by verifying security properties

Hardware Trojan Detection Using Effective Property-Checking Method

Hardware Trojans refer to additional logic maliciously implanted by attackers in integrated circuits (ICs). Because of the potential security threat of hardware Trojans, they have attracted extensive attention to security issues. As a formal verification method, property checking has been proved to be a powerful solution for hardware Trojan detection. However, existing property-checking methods are limited by the unity of security properties and the model explosion problem of formal models. The limitations above hinder the practical applications of these methods. To alleviate these challenges, we propose an effective property-checking method for hardware Trojan detection. Specifically, we establish the formal model based on the principle of finite state machine (FSM), and the method can alleviate the model explosion problem. For property writing, we extract the core behavior characteristics of hardware Trojans and then generate properties for the verification of certain types of hardware Trojans. Experimental results demonstrate that our approach is applicable to detect information leakage and denial of service (DoS) hardware Trojans by verifying security properties

Arylative Cyclization of 2‑Isocyanobiphenyls with Anilines: One-Pot Synthesis of 6‑Arylphenanthridines via Competitive Reaction Pathways

A transition-metal-free method for the synthesis of C6 phenanthridine derivatives by arylative cyclization of 2-isocyanobiphenyls with arylamines in one pot was developed. Mechanistic studies suggest that electrophilic aromatic substitution (S_EAr) of a nitrilium intermediate and homolytic aromatic substitution (HAS) of an imidoyl radical intermediate are two competitive reaction pathways involved in the annulation step

E-optimal designs for polynomial regression without intercept

We give all E-optimal designs for the mean parameter vector in polynomial regression of degree d without intercept in one real variable. The deviation is based on interplays between E-optimal design problems in the present and in certain heteroscedastic polynomial setups with intercept. Thereby the optimal supports are found to be related to the alternation points of the Chebyshev polynomials of the first kind, but the structure of optimal designs essentially depends on the regression degree being odd or even. In the former case the E-optimal designs are precisely the (infinitely many) scalar optimal designs, where the scalar parameter system refers to the Chebyshev coefficients, while for even d there is exactly one optimal design. In both cases explicit formulae for the corresponding optimal weights are obtained. Remarks on extending the results to E-optimality for subparameters of the mean vector (in heteroscdastic setups) are also given. (orig.)Available from TIB Hannover: RR 4487(1995,19) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekSIGLEDEGerman

Facile Chemical Solution Transportation for Direct Recycling of Iron Oxide Rust Waste to Hematite Films

Convenient and economic recycling of the environmental solid waste is one of the most essential and challenging issues for the sustainable development of modern society. In this work, for the first time, a chemical solution transportation method has been developed to convert iron oxides and related rust into (photo)­electroactive hematite films on a conductive F-doped SnO₂ substrate in a hydrothermal system. We found that the zeta potential of the substrate and the precursor particles could be modulated by controlling the NaNO₃ electrolyte concentration. The decrease of the positive surface charge densities caused less adsorption of Fe­(C₂O₄)₃^3– intermediates on the iron oxide precursors, while the intermediate adsorption at the F-SnO₂ substrate increased relatively. As a result, the small hematite nanocrystals were deposited on the substrate through an island nucleation mechanism, which transferred into a continuous dense hematite film with transportation time increase. These hematite films exhibited high photoelectrochemical and electrochemical activities in water oxidation for hydrogen generation. This direct chemical transportation method could be a promising solution for sustainable recycling of metal rust waste

A cross-sectional assessment of health-related quality of life in Chinese patients with chronic hepatitis c virus infection with EQ-5D

Abstract Background Hepatitis C virus (HCV) infection is one of the most common liver infections, with a decrement in HRQoL of HCV patients. This study aims to assess Health-related quality of life (HRQoL) in Chinese patients with chronic HCV infection, and to identify significant predictors of the HRQoL in these patients of China. Methods In this cross-sectional observational study, treatment-naïve Han ethnic adults with chronic HCV infection were enrolled. Adopting European Quality of Life scale (EQ-5D) and EuroQOL visual analogue scale (EQ-VAS) were used to qualify HRQoL. Results were reported in descriptive analyses to describe sociodemographic and clinical characteristics. Multiple linear regression analysis was applied to investigate the associations of these variables with HRQoL. Binary logistic regression analysis was performed to identify associations of these variables with HRQoL by dimensions of EQ-5D. Results Nine hundred ninety-seven patients were enrolled in the study [median age 46.0 (37.0, 56.0) years; male 54.8%]. Mean EQ-5D index and EQ-VAS score were 0.780 ± 0.083 and 77.2 ± 14.8. Multiple Linear regression analysis showed that income (< 2000 RMB, β = − 0.134; 2000–4999 RMB, β = − 0.085), moderate or severe symptoms of discomfort (more than one symptoms, β = − 0.090), disease profile (cirrhosis, β = − 0.114), hyperlipidemia (β = − 0.065) and depression (β = − 0.065) were independently associated with EQ-5D index. Residence (the west, β = 0.087), income (< 2000 RMB, β = − 0.129; 2000–4999 RMB, β = − 0.052), moderate or severe symptoms of discomfort (more than one symptoms, β = − 0.091), disease profile and depression (β = − 0.316) were the influencing factors on EQ-VAS. Binary logistic regression indicated that disease profile and clinical depression were the major influencing factors on all five dimensions of EQ-5D. Conclusions In this cross-sectional assessment of HCV patients in China, we indicated HRQoL of Chinese HCV patients. Significant negative associations between HRQoL and sociodemographic and clinical factors such as moderate or severe symptoms of discomfort, disease profile and depression emerged. We have to focus on optimally managing care of HCV patients and improving their HRQoL. Trial registration ClinicalTrials.gov identifier NCT01293279. Date of registration: February 10, 2011