The Impact of Prior Antithrombotic Use on Blood Viscosity in Cardioembolic Stroke with Non-Valvular Atrial Fibrillation.

Although clinical studies have demonstrated that prior use of antiplatelets was associated with decreased blood viscosity (BV) in patients with acute ischemic stroke, the impact of previous anticoagulant use on blood viscosity in cardioembolic stroke with non-valvular AF (NVAF) has not yet been clearly studied. This single-center retrospective observational study aimed to determine the impact of prior antithrombotic (antiplatelet and anticoagulant) use on BV in patients with cardioembolic stroke (CES) due to NVAF. Patients with CES and NVAF were analyzed with the following inclusion criteria: (1) patients over 20 years of age admitted within five days of stroke onset; (2) ischemic stroke presumably due to an NVAF-derived embolus; (3) compatible cortical/subcortical lesion on brain computed tomography or magnetic resonance imaging; (4) hemoglobin level of 10-18 mg/dL; and (5) receiving antiplatelets within five days or anticoagulants within two days if previously medicated. From the screening of 195 patients (22% of the total stroke population during the study period) who had experienced ischemic stroke with AF, 160 were included for the final analysis. Eighty-nine patients (56%) were taking antithrombotics (antiplatelet, 57%; warfarin, 13%; NOACs, 30%) regularly. Compared to patients without previous antithrombotic use, those with previous antithrombotic use (antiplatelets, warfarin, and NOACs) were significantly associated with decreased systolic BV (SBV) and diastolic BV (DBV) (p < 0.036). In multiple linear regression analysis, hematocrit (Hct) level and prior antithrombotic use were significantly associated with decreased SBV and DBV. Hct was positively correlated with increased SBV and DBV. In Hct-adjusted partial correlation analysis, prior uses of any antithrombotic agents were associated with decreased SBV (r < -0.270, p < 0.015) and DBV (r < -0.183, p < 0.044). In conclusion, this study showed that prior antithrombotic use (antiplatelets, VKAs, and NOACs) was associated with decreased SBV and DBV in patients presenting with acute CES secondary to NVAF. Our results indicated that previous use of NOACs may be a useful hemorheological parameter in patients with acute CES due to NVAF. Accumulation of clinical data from a large number of patients with the risk of stroke occurrence, initial stroke severity, and functional outcome is necessary to assess the usefulness of BV.

Electrical and Structural Characteristics of Excimer Laser-Crystallized Polycrystalline Si1-xGex Thin-Film Transistors.

We investigated the characteristics of excimer laser-annealed polycrystalline silicon-germanium (poly-Si1-xGex) thin film and thin-film transistor (TFT). The Ge concentration was increased from 0% to 12.3% using a SiH4 and GeH4 gas mixture, and a Si1-xGex thin film was crystallized using different excimer laser densities. We found that the optimum energy density to obtain maximum grain size depends on the Ge content in the poly-Si1-xGex thin film; we also confirmed that the grain size of the poly-Si1-xGex thin film is more sensitive to energy density than the poly-Si thin film. The maximum grain size of the poly-Si1-xGex film was 387.3 nm for a Ge content of 5.1% at the energy density of 420 mJ/cm2. Poly-Si1-xGex TFT with different Ge concentrations was fabricated, and their structural characteristics were analyzed using Raman spectroscopy and atomic force microscopy. The results showed that, as the Ge concentration increased, the electrical characteristics, such as on current and sub-threshold swing, were deteriorated. The electrical characteristics were simulated by varying the density of states in the poly-Si1-xGex. From this density of states (DOS), the defect state distribution connected with Ge concentration could be identified and used as the basic starting point for further analyses of the poly-Si1-xGex TFTs.

The Characteristics of Transparent Non-Volatile Memory Devices Employing Si-Rich SiOX as a Charge Trapping Layer and Indium-Tin-Zinc-Oxide.

We fabricated the transparent non-volatile memory (NVM) of a bottom gate thin film transistor (TFT) for the integrated logic devices of display applications. The NVM TFT utilized indium-tin-zinc-oxide (ITZO) as an active channel layer and multi-oxide structure of SiO2 (blocking layer)/Si-rich SiOX (charge trapping layer)/SiOXNY (tunneling layer) as a gate insulator. The insulators were deposited using inductive coupled plasma chemical vapor deposition, and during the deposition, the trap states of the Si-rich SiOx charge trapping layer could be controlled to widen the memory window with the gas ratio (GR) of SiH4:N2O, which was confirmed by fourier transform infrared spectroscopy (FT-IR). We fabricated the metal-insulator-silicon (MIS) capacitors of the insulator structures on n-type Si substrate and demonstrated that the hysteresis capacitive curves of the MIS capacitors were a function of sweep voltage and trap density (or GR). At the GR6 (SiH4:N2O = 30:5), the MIS capacitor exhibited the widest memory window; the flat band voltage (ΔVFB) shifts of 4.45 V was obtained at the sweep voltage of ±11 V for 10 s, and it was expected to maintain ~71% of the initial value after 10 years. Using the Si-rich SiOX charge trapping layer deposited at the GR6 condition, we fabricated a bottom gate ITZO NVM TFT showing excellent drain current to gate voltage transfer characteristics. The field-effect mobility of 27.2 cm2/Vs, threshold voltage of 0.15 V, subthreshold swing of 0.17 V/dec, and on/off current ratio of 7.57 × 107 were obtained at the initial sweep of the devices. As an NVM, ΔVFB was shifted by 2.08 V in the programing mode with a positive gate voltage pulse of 11 V and 1 µs. The ΔVFB was returned to the pristine condition with a negative voltage pulse of -1 V and 1 µs under a 400-700 nm light illumination of ~10 mWcm-2 in erasing mode, when the light excites the electrons to escape from the charge trapping layer. Using this operation condition, ~90% (1.87 V) of initial ΔVFB (2.08 V) was expected to be retained over 10 years. The developed transparent NVM using Si-rich SiOx and ITZO can be a promising candidate for future display devices integrating logic devices on panels.

Improvement of Electrical Performance in P-Channel LTPS Thin-Film Transistor with a-Si:H Surface Passivation.

We report the effects of surface passivation by depositing a hydrogenated amorphous silicon (a-Si:H) layer on the electrical characteristics of low temperature polycrystalline silicon thin film transistors (LTPS TFTs). The intrinsic a-Si:H layer was optimized by hydrogen dilution and its structural and electrical characteristics were investigated. The a-Si:H layer in the transition region between a-Si:H and µc-Si:H resulted in superior device characteristics. Using a-Si:H passivation layer, the field-effect mobility of the LTPS TFT was increased by 78.4% compared with conventional LTPS TFT. Moreover, the leakage current measured at VGS of 5 V was suppressed because the defect sites at the poly-Si grain boundaries were well passivated. Our passivation layer, which allows thorough control of the crystallinity and passivation-quality, should be considered as a candidate for high performance LTPS TFTs.

New perspectives on Mega plasmid sequence (poh1) in Bacillus thuringiensis ATCC 10792 harbouring antimicrobial, insecticidal and antibiotic resistance genes.

Bacillus thuringiensis promotes the growth of numerous economically important crops. The present study presents the complete genome sequence for a mega plasmid present in the type strain of B. thuringiensis ATCC 10792, a typical spore-forming Gram-positive bacterium with insecticidal activity, and investigates its genetic characteristics. The genome was sequenced and assembled de novo using Pac-Bio sequencers and the Hierarchical Genome Assembly Process, respectively. Further genome annotation was performed, and a total of 489 proteins and a novel mega-plasmid (poh1) with 584,623 bps were identified. The organization of poh1 revealed the genes involved in the insecticidal toxin pathway. The genes responsible for antimicrobial, insecticidal and antibiotic activities were well conserved in poh1, indicating an intimate association with plant hosts. The poh1 plasmid contains the gene encoding a novel crystal protein kinase responsible for production of zeta toxin, which poisons insects and other Gram-negative bacteria through the global inhibition of peptidoglycan synthesis. Lantibiotics are a group of bacteriocins that include the biologically active antimicrobial peptide Paenibacillin. Further, poh1 also contains the genes that encode the gramicidin S prototypical antibiotic peptide and tetracycline resistance protein. In conclusion, the strain-specific genes of B. thuringiensis strain ATCC 10792 were identified through complete genome sequencing and bioinformatics data based on major pathogenic factors that contribute to further studies of the pathogenic mechanism and phenotype analyses.

Microbiological Quality and Safety of Fresh Fruits and Vegetables at Retail Levels in Korea.

The aim of this study was to evaluate the microbiological quality and safety of fresh produce at retail level in Korea in order to periodically update information and establish available risks associated with consumption of fresh fruits and vegetables. The samples from different markets located in 3 provinces of South Korea were collected. The protocol in the Korean Food Standards Codex was applied and generic Escherichia coli, coliforms, aerobic mesophilic bacteria (AMB), and yeast and mold (YM) in 360 packaged and unpackaged fresh fruits and vegetables were analyzed. Presence of pathogens was examined using real-time polymerase chain reaction (q-PCR) after enrichment of samples. For all, the microbial counts ranged from 1.7 to 10.6 log cfu/g for AMB, 2.2 to 7.9 log cfu/g for coliforms, and 5.5 to 7.9 log cfu/g for YM. Three lettuce samples were contaminated by E. coli with a bacterial load ranging from 2 to 4 log cfu/g. Salmonella spp. were not detected in any fresh produce. Listeria monocytogenes, E. coli O157:H7, and Staphylococcus aureus were found in 1 (0.6%), 3 (0.8%), and 5 (1.4%) fresh produce samples, respectively. Bacillus cereus (50.3%) and Clostridium perfringens (13.3%) had the highest prevalence. These results indicate the need for employing strict control measures and developing preventive strategies to improve the quality and safety of fresh produce in Korea.

Molecular discrimination of Bacillus cereus group species in foods (lettuce, spinach, and kimbap) using quantitative real-time PCR targeting groEL and gyrB.

The aim of the study was to identify and evaluate specific biomarkers to differentiate within Bacillus cereus group species from contaminated food samples with the use of real-time PCR. A total of 120 strains, comprising of 28 reference, 2 type, 78 wild strains of B. cereus and B. thuringiensis along with 12 strains representing 2 bacterial groups - B. mycoides, B. pseudomycoides, B. weihenstephanensis (B. cereus group); B. amyloliquefaciens, B. subtilis, Enterococcus faecalis, Escherichia coli, Listeria monocytogenes, Micrococcus luteus, Salmonella enterica, Staphylococcus aureus, Streptococcus pyogenes (non-Bacillus sp.) were identified by applying valid biomarkers (groEL and gyrB). In addition, the presence of B. cereus group was determined in three different artificially contaminated vegetable samples (lettuce, spinach, and kimbap), using prominent biomarkers targeting on chaperonin protein (GroEL) and topoisomerase enzyme protein (gyrB). Direct analysis of samples revealed the specificity towards identification and characterization of the B. cereus group among wild, reference and type strains and the type strain inoculated in vegetables. Our results demonstrated two existing biomarkers groEL and gyrB with a high specificity of 98% and 96% respectively to analyze the total B. cereus group. Further, we also reported the detection limit of groEL and gyrB in food samples was 3.5 and 3.7 log CFU/g respectively. Thus, the developed real-time PCR approach can be a reliable and effective tool for the identification of B. cereus group strains present in environment and food samples. This does not require band isolation, re-amplification, sequencing or sequence identification, thus reducing the time and cost of analysis.

Unique biomarkers as a potential predictive tool for differentiation of Bacillus cereus group based on real-time PCR.

The aim of the study was to develop unique biomarkers for qPCR detection of Bacillus cereus group. Clinical and soil isolates were identified by specifically designed biomarkers - Lipoprotein (OPL-114-lipo), Methyltransferase (MT-17) and S-layer homology domain protein (151-1BC). In order to design biomarkers, we used 120 bacterial strains grouped into B. cereus and non-Bacillus group. The B. cereus group was confirmed by 108 strains of B. cereus and B. thuringiensis (30 reference and 78 wild), along with 3 strains of B. mycoides, B. pseudomycoides, and B. weihenstephanensis; while the non-Bacillus group was composed of 9 Gram-positive and Gram-negative strains. Direct analysis of samples revealed specificity towards identification and characterization of B. cereus group. The newly developed markers OPL-114-lipo and MT-17 showed specificity of 95% and 81%, respectively in identification of B. cereus. They are efficient tools to identify contaminated sources and the degree of bacterial contamination. Environmental and food samples do not require band isolation, re-amplification, sequencing or sequence identification. Thus, reducing the time and cost of analysis. Hence, it will be an alternative approach to traditional culture methods. Commercial food processing industries will be able to employ these biomarkers specific for B. cereus group as a detection tool to reduce economic loss due to B. cereus contamination.

Radiculopathy in neuromyelitis optica. How does anti-AQP4 Ab involve PNS?

BACKGROUND: Until recently, the peripheral nervous system (PNS) had been known to be spared in multiple sclerosis (MS) and neuromyelitis optica spectrum disorder (NMOSD). However, some studies of late have reported PNS damage in demyelination diseases of the central nervous system (CNS) such as MS and NMOSD. Although multiple studies have reported characteristics reminiscent of peripheral neuropathy in MS, there have been limited reports in NMOSD. To investigate the incidence and pathology of peripheral neuropathy in NMOSD, we reviewed articles describing such cases including our own case. METHODS: We performed a search of all clinical studies of peripheral neuropathy in NMOSD published up to December 17, 2016. We put no restrictions on language or year of publication in our search. The following keywords were searched: radiculopathy, peripheral nervous system diseases, neuromyelitis optica, neuromyelitis optica septrum disorder, aquaporin 4, electrodiagnosis, neural conduction and electromyography. RESULT: We review ten cases (nine published reports and our own case study) of peripheral neuropathy in NMOSD. Each case could be confirmed as radiculopathy by electrodiagnostic (EDX) testing. Presently, there are two disparate viewpoints on peripheral neuropathy in NMOSD. In the first, aquaporin 4, which exists in the transitional zone of the CNS-PNS at the root level, may be the target of radiculitis in NMOSD. In the second, there may be some other unknown antibody to an axoglial antigen or something else that may play an active role in PNS damage. In our survey of ten case studies, the EDX results confirmed mixed axonal loss as well as demyelination type radiculopathy, which lends support to the first viewpoint. CONCLUSION: Pathophysiology of PNS damage in NMOSD might be due to radiculopathy. Although it seems to be rare, radiculopathy may actually be underestimated, and correspondingly underreported, due to its overlap with symptoms of myelitis. Therefore, further evaluation is needed to establish the incidence and pathophysiology of radiculopathy in NMOSD.

Predictive Model for Growth of Staphylococcus aureus on Raw Pork, Ham, and Sausage.

Recent Staphylococcus aureus outbreaks linked to meat and poultry products underscore the importance of understanding the growth kinetics of S. aureus in these products at different temperatures. Raw pork, ham, and sausage (each 10 ± 0.3 g) were inoculated with a three-strain cocktail of S. aureus, resulting in an initial level of ca. 3 log CFU/g. Samples were stored isothermally at 10, 15, 20, 25, 30, 35, and 40°C, and S. aureus was enumerated at appropriate time intervals. The square root model was developed using experimental data collected from S. aureus grown on all samples (where data from raw pork, ham, and sausage were combined) so as to describe the growth rate of S. aureus as a function of temperature. The model was then compared with models for S. aureus growth on each individual sample in the experiments (raw pork, ham, or sausage) and the S. aureus ComBase models, as well as models for the growth of different types of pathogens (S. aureus, Escherichia coli O157:H7, Clostridium perfringens, Salmonella serovars, and Salmonella Typhimurium) on various types of meat and poultry products. The results show that the S. aureus model developed here based on the pooled data from all three pork products seems suitable for the prediction of S. aureus growth on different pork products under isothermal conditions from 10 to 25°C, as well as for S. aureus growth on different meat and poultry products at higher temperatures between 20 and 35°C. Regardless of some high deviations observed at temperatures between 25 and 40°C, the developed model still seems suitable to predict the growth of other pathogens on different types of meat and poultry products over the temperature ranges used here, especially for E. coli O157:H7 and Salmonella Typhimurium. The developed model, therefore, may be useful for estimating the effects of storage temperature on the behavior of pathogens in different meat and poultry products and for microbial risk assessments evaluating meat safety.

Microbiological Analysis of Rice Cake Processing in Korea.

This study was conducted to evaluate the microbial contamination in rice cake materials and products during processing and in the operation environment in nonhazard analysis [and] critical control point factories. Furthermore, the environmental health of the processing facilities and the bacterial and fungal contamination on the workers' hands were investigated. Pour plate methods were used for enumeration of aerobic plate count (APC), yeast and molds (YM), Bacillus cereus, Staphylococcus aureus, and Clostridium perfringens, whereas Petrifilm count plates were used for enumeration of coliforms and Escherichia coli. The respective microbial levels of APC, coliforms, YM, and B. cereus were in the range of 2.6 to 4.7, 1.0 to 3.8, not detected (ND) to 2.9, and ND to 2.8 log CFU/g in the raw materials and in the range of 2.3 to 6.2, ND to 3.6, ND to 2.7, and ND to 3.7 log CFU/g during processing of the rice cake products. During the processing of rice cakes, APC, coliforms, YM, and B. cereus increased during soaking and smashing treatments and decreased after steaming treatment. E. coli, S. aureus, and C. perfringens were not detected in any of the raw materials and operating areas or during processing. B. cereus was detected on the operators' hands at microbial contamination levels of 1.9 ± 0.19 to 2.0 ± 0.19 log CFU/g. The results showed that B. cereus in the end product is presumably the main concern for rice cakes. In addition, the high contamination level of B. cereus during manufacturing processes, including soaking, smashing, and molding, and the absence of B. cereus from the air sampling plates indicated that the contaminated equipment showed the potential risk to cause cross-contamination.

Effect of water hardness on the production and microbicidal efficacy of slightly acidic electrolyzed water.

Slightly acidic electrolyzed water (SAEW) has been proved as an effective sanitizer against microorganisms attached to foods. However, its physical properties and inactivation efficacy are affected by several factors such as water hardness. Therefore, in this study the effect of water hardness on SAEW properties were studied. Pure cultures of foodborne bacteria were used in vitro and in vivo to evaluate the inactivation efficacy of the SAEWs produced. Results obtained showed water hardness to be an important factor in the production of SAEW. Low water hardness may result in the necessity of further optimization of production process. In this study the addition of 5% HCl and 2 M NaCl at 1.5 mL/min flow rate was found to be the best electrolyte concentration for the optimization of SAEW production from low hardness water (34 ± 2 mg/L). Furthermore, the results showed that pre-heating was a better approach compared to post-production heating of SAEW, resulting in higher ACC values and therefor better sanitization efficacy.

Analysis of microbiological contamination in mixed pressed ham and cooked sausage in Korea.

The objective of this study was to investigate the microbial contamination levels (aerobic bacteria plate count [APC], coliforms, Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes) in mixed pressed ham and cooked sausage. A total of 180 samples were collected from factories with and without hazard analysis critical control point (HACCP) systems at four steps: after chopping (AC), after mixing (AM), cooling after the first heating process, and cooling after the second heating process. For ham, APCs and coliform and E. coli counts increased when ingredients were added to the meat at the AC step. Final product APC was 1.63 to 1.85 log CFU/g, and coliforms and E. coli were not detected. S. aureus and L. monocytogenes were found in nine (15.0%) and six (10.0%) samples, respectively, but only at the AC and AM steps and not in the final product. Sausage results were similar to those for ham. The final product APC was 1.52 to 3.85 log CFU/g, and coliforms and E. coli were not detected. S. aureus and L. monocytogenes were found in 29 (24.2%) and 25 (20.8%) samples at the AC and AM steps, respectively, but not in the final product. These results indicate that the temperature and time of the first and second heating are of extreme importance to ensure the microbiological safety of the final product regardless of whether a HACCP system is in place. Microorganism contamination must be monitored regularly and regulations regarding sanitization during processing should be improved. Education regarding employee personal hygiene, environmental hygiene, prevention of cross-contamination, ingredient control, and step-by-step process control is needed to reduce the risk of food poisoning.

Rapid detection of viable Escherichia coli O157 by coupling propidium monoazide with loop-mediated isothermal amplification.

Conventional molecular detection methods cannot distinguish between viable and dead Escherichia coli O157 cells. In this study, the loop-mediated isothermal amplification (LAMP) method combined with propidium monoazide (PMA) treatment was developed to selectively detect viable E. coli O157 cells. Four primers, including outer primers and inner primers, were specially designed for the recognition of six distinct sequences on the serogroups (O157) of the specific rfbE gene of the E. coli O157 genome. PMA selectively penetrated through the compromised cell membranes and intercalated into DNA. Amplification of DNA from dead cells was completely inhibited by 3.0 µg/ml PMA, whereas the DNA derived from viable cells was amplified remarkably within 1 h by PMA-LAMP. Exhibiting high sensitivity and specificity, PMA-LAMP is a suitable method for evaluating the inactivation efficacy of slightly acidic electrolyzed water in broth. PMA-LAMP can selectively detect viable E. coli O157 cells. This study offers a novel molecular detection method to distinguish between viable and dead E. coli O157 cells.

Genetic diversity of emetic toxin producing Bacillus cereus Korean strains.

Bacillus cereus is divided into emetic and enterotoxin producing strains. Emetic B. cereus showed the low level of genetic diversity and single evolutionary lineage but no specific study of the genotypic characterization of emetic B. cereus Korean strains has been conducted. The objective of this study was to investigate the genotypic diversity of emetic B. cereus Korean strains. A total 39 strains (35 clinical and 4 food isolates) was analyzed for the genotypic characterization. A total of 17 distinct patterns were obtained from the random-amplified polymorphic DNA (RAPD) banding patterns and the majority of clusters belong to group 3. The pulsed-field gel electrophoresis (PFGE) banding patterns were divided into 17 distinct pulsotypes, and groups B and C were dominated. Emetic B. cereus Korean strains showed diverse pulsotypes in contrast with previous studies. All strains were resistant to ß-lactam antibiotics such as penicillin and ampicillin. Combining biochemical properties, PFGE types, RAPD types and antibiotic resistance types, a total of 7 composite clusters were found. The majority of composite clusters were consisted with cluster 5 and 6. Enterotoxin producing reference strains belong to composite cluster 7. However, JNHE 6 (Jeollabuk-do Research Institute of Health & Environment; cluster 1) and JNHE 36 (cluster 2) which possessed the ability of starch hydrolysis and saline fermentation showed different composite clusters comparing with most emetic B. cereus. JNHE 7 and JNHE 53 formed composite cluster 3 and 4. Emetic B. cereus Korean strains showed genotypic diversity comparing with the previous studies.