Exploratory Study on the Methodology of Fast Imaging of Unilateral Stroke Lesions by Electrical Impedance Asymmetry in Human Heads

Stroke has a high mortality and disability rate and should be rapidly diagnosed to improve prognosis. Diagnosing stroke is not a problem for hospitals with CT, MRI, and other imaging devices but is difficult for community hospitals without these devices. Based on the mechanism that the electrical impedance of the two hemispheres of a normal human head is basically symmetrical and a stroke can alter this symmetry, a fast electrical impedance imaging method called symmetrical electrical impedance tomography (SEIT) is proposed. In this technique, electrical impedance tomography (EIT) data measured from the undamaged craniocerebral hemisphere (CCH) is regarded as reference data for the remaining EIT data measured from the other CCH for difference imaging to identify the differences in resistivity distribution between the two CCHs. The results of SEIT imaging based on simulation data from the 2D human head finite element model and that from the physical phantom of human head verified this method in detection of unilateral stroke

Quantitative index of EIT based on 3D abdominal bleeding simulation model

According CT images, a 3D abdominal bleeding simulation model with real shape was set up using COMOSOL Multi-physics. By parameter sweeping, the surface measurement data for EIT were obtained while bleeding from 0~800ml. Total relative changes (TRC) of the data were calculated, shown a linear correlation (R>0.99) with bleeding volume (BV), which implies TRC be a good quantitative index to indicate BV

Recommender System-Based Diffusion Inferring for Open Social Networks

Open social network (OSN) plays a more significant role in information propagation through the rapid developing of information technology. Since information diffusion is an essential process happens in OSN, it has been studied in many studies. Several models have been proposed to infer the diffusion process and reproduce diffusion network. However, these methods have two critical problems: 1) ignoring the effects of user social characteristics and 2) inaccuracy resulted from calculating the influence of different features independently. To address these limitations, a diffusion inferring method based on a recommender system (DIM-SPTF) was proposed. The DIM-SPTF method considers the propagation process between the users as the recommendation process of information and employs a recommender system to infer the propagation relationship. Through determining the propagation relations among all users in the observed topic data set, an information diffusion network can be finally obtained. Experimental results show that DIM-SPTF leads to improvements in performance compared with the state-of-the-art methods

“Hot Edges” in Inverse Opal Structure Enable Efficient CO2 Electrochemical Reduction and Sensitive in-situ Raman Characterization

Conversion of CO 2 into fuels and chemicals via electroreduction has attracted significant interest. Via mesostructure design to tune the electric field distribution in the electrode, it is demonstrated that the Cu-In alloy with an inverse opal (CI-1-IO) structure provides efficient electrochemical CO 2 reduction and allows for sensitive detection of the CO 2 reduction intermediates via surface-enhanced Raman scattering. The significant enhancement of Raman signals of the intermediates on the CI-1-IO surface can be attributed to electric field enhancement on the "hot edges" of the inverse opal structure. Additionally, a highest CO 2 reduction faradaic efficiency (FE) of 92% (sum of formate and CO) is achieved at-0.6 V vs. RHE on the CI-1-IO electrode. The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) results show that the Cu-In alloy with an inverse opal structure has faster adsorption kinetics and higher adsorption capacity for CO 2. The "hot edges" of the bowl-like structure concentrate electric fields, due to the high curvature, and also concentrate K + on the active sites, which can lower the energy barrier of the CO 2 reduction reaction. This research provides new insight into the design of materials for efficient CO 2 conversion and the detection of intermediates during the CO 2 reduction process. </p

A Glimpse of Streptococcal Toxic Shock Syndrome from Comparative Genomics of S. suis 2 Chinese Isolates

BACKGROUND: Streptococcus suis serotype 2 (SS2) is an important zoonotic pathogen, causing more than 200 cases of severe human infection worldwide, with the hallmarks of meningitis, septicemia, arthritis, etc. Very recently, SS2 has been recognized as an etiological agent for streptococcal toxic shock syndrome (STSS), which was originally associated with Streptococcus pyogenes (GAS) in Streptococci. However, the molecular mechanisms underlying STSS are poorly understood. METHODS AND FINDINGS: To elucidate the genetic determinants of STSS caused by SS2, whole genome sequencing of 3 different Chinese SS2 strains was undertaken. Comparative genomics accompanied by several lines of experiments, including experimental animal infection, PCR assay, and expression analysis, were utilized to further dissect a candidate pathogenicity island (PAI). Here we show, for the first time, a novel molecular insight into Chinese isolates of highly invasive SS2, which caused two large-scale human STSS outbreaks in China. A candidate PAI of ∼89 kb in length, which is designated 89K and specific for Chinese SS2 virulent isolates, was investigated at the genomic level. It shares the universal properties of PAIs such as distinct GC content, consistent with its pivotal role in STSS and high virulence. CONCLUSIONS: To our knowledge, this is the first PAI candidate from S. suis worldwide. Our finding thus sheds light on STSS triggered by SS2 at the genomic level, facilitates further understanding of its pathogenesis and points to directions of development on some effective strategies to combat highly pathogenic SS2 infections

Use of electrical impedance tomography to monitor dehydration treatment of cerebral edema: a clinical study

In this study EIT was used to monitor brain impedance changes due to variations in cerebral fluid content during dehydration treatment of edema patients. 30 patients with cerebral edema were continuously imaged for two hours after the initiation of dehydration treatment. Results show that overall impedance across the brain increased significantly 5 minutes after dehydration treatment started. And different brain tissues have different reactions towards dehydration

SalK/SalR, a Two-Component Signal Transduction System, Is Essential for Full Virulence of Highly Invasive Streptococcus suis Serotype 2

BACKGROUND: Streptococcus suis serotype 2 (S. suis 2, SS2) has evolved into a highly infectious entity, which caused the two recent large-scale outbreaks of human SS2 epidemic in China, and is characterized by a toxic shock-like syndrome. However, the molecular pathogenesis of this new emerging pathogen is still poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: 89K is a newly predicted pathogenicity island (PAI) which is specific to Chinese epidemic strains isolated from these two SS2 outbreaks. Further bioinformatics analysis revealed a unique two-component signal transduction system (TCSTS) located in the candidate 89K PAI, which is orthologous to the SalK/SalR regulatory system of Streptococcus salivarius. Knockout of salKR eliminated the lethality of SS2 in experimental infection of piglets. Functional complementation of salKR into the isogenic mutant DeltasalKR restored its soaring pathogenicity. Colonization experiments showed that the DeltasalKR mutant could not colonize any susceptible tissue of piglets when administered alone. Bactericidal assays demonstrated that resistance of the mutant to polymorphonuclear leukocyte (PMN)-mediated killing was greatly decreased. Expression microarray analysis exhibited a transcription profile alteration of 26 various genes down-regulated in the DeltasalKR mutant. CONCLUSIONS/SIGNIFICANCE: These findings suggest that SalK/SalR is requisite for the full virulence of ethnic Chinese isolates of highly pathogenic SS2, thus providing experimental evidence for the validity of this bioinformatically predicted PAI