381 research outputs found

    Dynamic Adsorption Behaviors of Various Zeolites for the Adsorbent of Air Separation by Pressure-swing Adsorption Method

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    Adsorption behaviors of O₂ and N₂ in pressure-swing adsorption (PSA) at lower temperature on various American natural zeolites and synthetic zeolites having different pore structures were studied. The adsorption properties were largely dependent on whether the dimension of the pore-structure connection is one or three. Molecular sieves MS-5A and MS-4A, which have a large amount of adsorption and a large difference in adsorption capacity for N₂ and O₂, were preferable to air separation by the PSA method. The applicability to the air separation at low temperature was also investigated by using MS-4A and MS-5A as the adsorbent. Highly concentrated N₂ was obtained by MS-5A in the elution period and by MS-4A in the adsorption period. Furthermore, the applicability to the air separation at room temperature was examined by using MS-4A as the adsorbent, and the separation was confirmed at this condition

    Risk Assessment of Arsenic in Rice Cereal and Other Dietary Sources for Infants and Toddlers in the U.S.

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    Currently, there are no set standards or quantitative guidelines available in the U.S. for arsenic levels in rice cereal, one of the most common first solid foods for infants. The objective of this study was to evaluate whether the detected levels of inorganic arsenic (Asi) in rice cereal in the U.S. market are safe for consumption by infants and toddlers. A risk assessment was conducted based on literature reviews of the reported Asi in rice cereal from the U.S. Food and Drug Administration’s (FDA) survey and the recommended daily intake of rice cereal by body weight, for infants and toddlers between four and 24 months old. As a part of risk management, a maximum contaminant level (MCL) for Asi in rice cereal was computed considering overall exposure sources including drinking water, infant formula, and other infant solid foods. Hazard quotients (HQs) for acute and chronic exposures were calculated based on the U.S. Agency for Toxic Substances and Disease Registry’s (ATSDR) Minimal Risk Level (MRL)acute (5.0 × 10−3 mg/kg/day) and MRLchronic (3.0 × 10−4 mg/kg/day). A cancer slope or potency factor of 1.5 mg/kg/day was used to predict an incremental lifetime cancer risk (ILCR). Exposure assessment showed that the largest source of Asi for infants and toddlers between four and 24 months old was rice cereal (55%), followed by other infant solid food (19%), and drinking water (18%). Infant formula was the smallest source of Asi for babies (9%) at the 50th percentile based on Monte Carlo simulations. While HQacute were consistently below 1.0, HQchronic at the 50 and 75th percentiles exceeded 1.0 for both rice cereal and total sources. ILCR ranged from 10−6 (50th) to 10−5 (75th percentile). MCLs for Asi in rice cereal ranged from 0.0 (chronic) to 0.4 mg/kg (acute exposures).This article is made openly accessible in part by an award from the Northern Illinois University Libraries’ Open Access Publishing Fund

    Artificial Intelligence-based Detection of Epileptic Discharges from Pediatric Scalp Electroencephalograms: A Pilot Study

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    We developed an artificial intelligence (AI) technique to identify epileptic discharges (spikes) in pediatric scalp electroencephalograms (EEGs). We built a convolutional neural network (CNN) model to automatically classify steep potential images into spikes and background activity. For the CNN model’ training and validation, we examined 100 children with spikes in EEGs and another 100 without spikes. A different group of 20 children with spikes and 20 without spikes were the actual test subjects. All subjects were ≥ 3 to 0.97 when referential and combination EEG montages were used, and 0.99, indicating high performance of the classification method. EEG patterns that interfered with correct classification included vertex sharp transients, sleep spindles, alpha rhythm, and low-amplitude ill-formed spikes in a run. Our results demonstrate that AI is a promising tool for automatically interpreting pediatric EEGs. Some avenues for improving the technique were also indicated by our findings

    Exclusion of the Possibility of "False Ripples" From Ripple Band High-Frequency Oscillations Recorded From Scalp Electroencephalogram in Children With Epilepsy

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    Aim Ripple-band epileptic high-frequency oscillations (HFOs) can be recorded by scalp electroencephalography (EEG), and tend to be associated with epileptic spikes. However, there is a concern that the filtration of steep waveforms such as spikes may cause spurious oscillations or "false ripples." We excluded such possibility from at least some ripples by EEG differentiation, which, in theory, enhances high-frequency signals and does not generate spurious oscillations or ringing. Methods The subjects were 50 pediatric patients, and ten consecutive spikes during sleep were selected for each patient. Five hundred spike data segments were initially reviewed by two experienced electroencephalographers using consensus to identify the presence or absence of ripples in the ordinary filtered EEG and an associated spectral blob in time-frequency analysis (Session A). These EEG data were subjected to numerical differentiation (the second derivative was denoted as EEG ''). The EEG '' trace of each spike data segment was shown to two other electroencephalographers who judged independently whether there were clear ripple oscillations or uncertain ripple oscillations or an absence of oscillations (Session B). Results In Session A, ripples were identified in 57 spike data segments (Group A-R), but not in the other 443 data segments (Group A-N). In Session B, both reviewers identified clear ripples (strict criterion) in 11 spike data segments, all of which were in Group A-R (p < 0.0001 by Fisher's exact test). When the extended criterion that included clear and/or uncertain ripples was used in Session B, both reviewers identified 25 spike data segments that fulfilled the criterion: 24 of these were in Group A-R (p < 0.0001). Discussion We have demonstrated that real ripples over scalp spikes exist in a certain proportion of patients. Ripples that were visualized consistently using both ordinary filters and the EEG '' method should be true, but failure to clarify ripples using the EEG '' method does not mean that true ripples are absent. Conclusion The numerical differentiation of EEG data provides convincing evidence that HFOs were detected in terms of the presence of such unusually fast oscillations over the scalp and the importance of this electrophysiological phenomenon

    The Role of RANTES Promoter Polymorphism in Functional Dyspepsia

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    Altered inflammatory immune responses have been shown to be associated with functional gastro intestinal disorder. We aimed to clarify the effect of functional promoter polymorphism of RANTES, which is a potent chemoattractant peptide for memory T lymphocytes and eosinophils, on the risk of functional dyspepsia in a Japanese population. RANTES promoter C-28G polymorphism was genotyped in 246 subjects including 134 FD patients according to Roma III criteria and 112 non-symptomatic healthy controls. Although frequency of RANTES promoter polymorphisms in overall dyspeptic patients and non-symptomatic healthy controls did not show any significant differences, a significant association was found between G carrier and reduced risk of PDS according to Roma III criteria (age, sex, H. pylori infection adjusted OR  = 0.23, 95% CI = 0.06–0.80). We also found that the same genotype held a lower risk of PDS in H. pylori positive PDS subjects (age, sex adjusted OR = 0.11, 95% CI = 0.01–0.94). Our data suggest that RANTES promoter -28G carriers is associate with a reduced risk of PDS especially in H. pylori positive subjects

    Absence of Common Polymorphisms of Toll Like Receptor 4 (TLR4): Asp299Gly, Thr399Ile in Patients with Gastroduodenal Diseases in Japan

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    Host genetic factors may play a key role in determining the long-term outcome of the Helicobacter pylori (H. pylori) infection. Toll-like receptor 4 (TLR4) mediated recognition of lipo-polysaccharide (LPS) is required for efficient recognition of gram-negative bacterial infections. The aim of this study is to investigate the effects of common polymorphisms of TLR4 Asp299Gly, Thr399Ile in patients with gastroduodenal diseases in Japanese population. The study was performed in 149 gastric cancer (GC) cases (mean age 64.0 ± 12.4, M:F = 109:40) and 94 patients without evidence of GC (mean age 64.1 ± 12.3, M:F = 65:25) as the control group. TLR4 Asp299Gly, Thr399Ile were determined by Polymerase chain reaction-length of polymorphisms (PCR-RFLP) in all the patients. Asp299Gly, Thr399Ile were not detected in all 243 patients enrolled in this study. In conclusion, our data suggest that TLR4 Asp299Gly, Thr399Ile are very rare in Japanese population and thus they may not be a important factor in determining the outcome of H. pylori infected individuals in Japan

    Analysis of Beta-Tubulin Gene Exon 4 Mutations in Advanced Stage III or IV Gastric Cancer

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    The mechanisms that cause chemoresistance of gastric cancer have yet to be elucidated. Taxanes and promising agents that were recently approved for treatment of advanced or recurrent gastric cancer. Mutations of beta-tubulin, which is a target of taxianes, have been shown to confer chemoresistance against these agents. The aim of the present study is to investigate the presence of mutations of the beta-tubulin in gastric cancer tissues. Sixty-six patients with advanced stage III or IV gastric cancer patients enrolled in this study. Paired samples of gastric cancer tissue and normal mucosa were obtained by endoscopy. The guanosine 5'-triphosphate (GTP)-binding site in exon 4 of the beta-tubulin gene was examined by polymerase chain reaction single-strand conformational polymorphism (PCR-SSCP) analysis, followed by sequencing of the products with abnormally shifted bands. SSCP analysis showed abnormal bands upstream of the GTP-binding site in 7 of the 66 patients, but sequence analysis found no nucleotide substitutions in these patients. Three variant bands were also detected down stream of the the GTP-binding site, but the sequences of the 3 products corresponded to those of two independent pseudogenes. Thus, none of the tumor samples showed mutation of the beta-tubulin exon 4 GTP-binding site. In conclusion, these findings suggest that mutations of the beta-tubulin gene are rare and are unlikely to be an important cause of taxane resistance to taxians
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