Using hydrothermal synthesis, a highly hydrophobic DDR-type zeolite membrane was prepared on the outer surface of a porous α-alumina tube. The results of this study show that it is useful for CO2/CH4 separation. Single-gas permeation for CO2, CH4, H2, He, N2, and O2, and CO2/CH4 binary gas permeation, were measured, respectively, at pressures up to 5 and 2 MPa. The respective single-gas permeances of CO2 and CH4 at 298 K at a feed pressure of 0.2 MPa and a permeate pressure of 0.1 MPa were 4.2 × 10-7 and 1.2 × 10-9 mol m-2 s-1 Pa-1; the ideal selectivity for CO2/CH4 was 340. The permeances were in the following order: CO2 > H2 > He > O2 > N2 > CH4. Single-gas permeance was dependent on the relative molecular size of the DDR pore diameter. However, CO2 permeance dominated the adsorption affinity to the pore wall of DDR zeolite. In mixed-gas permeation experiments using the sweep method, the DDR-type zeolite membrane showed high selectivity for CO2/CH4 mixtures of 200 and high CO2 permeance of 3.0 × 10-7 mol m-2 s-1 Pa-1 at 298 K with a feed pressure of 0.2 MPa. Furthermore, the DDR zeolite membranes were compared to other zeolite membranes for evaluation of their CO2/CH4 selectivity and CO2 permeance; the DDR-type zeolite membranes show better CO2/CH4 separation and CO2 permeance.
BackgroundThe chronic obstructive pulmonary disease (COPD) Assessment Test (CAT) is a concise health status measure for COPD. COPD patients have a variety of comorbidities, but little is known about their impact on quality of life. This study was designed to investigate comorbid factors that may contribute to high CAT scores.MethodsAn observational study at Keio University and affiliated hospitals enrolled 336 COPD patients and 67 non-COPD subjects. Health status was assessed by the CAT, the St. Georges Respiratory Questionnaire (SGRQ), and all components of the Medical Outcomes Study Short-Form 36-Item (SF-36) version 2, which is a generic measure of health. Comorbidities were identified based on patients’ reports, physicians’ records, and questionnaires, including the Frequency Scale for the Symptoms of Gastro-esophageal reflux disease (GERD) and the Hospital Anxiety and Depression Scale. Dual X-ray absorptiometry measurements of bone mineral density were performed.ResultsThe CAT showed moderate-good correlations with the SGRQ and all components of the SF-36. The presence of GERD, depression, arrhythmia, and anxiety was significantly associated with a high CAT score in the COPD patients.ConclusionsSymptomatic COPD patients have a high prevalence of comorbidities. A high CAT score should alert the clinician to a higher likelihood of certain comorbidities such as GERD and depression, because these diseases may co-exist unrecognized.Trial registrationClinical trial registered with UMIN (UMIN000003470).
Sulfonylurea-resistant biotypes of Schoenoplectus juncoides were collected from Nakafurano, Shiwa, Matsuyama, and Yurihonjyo in Japan. All of the four biotypes showed resistance to bensulfuron-methyl and thifensulfuron-methyl in whole-plant experiments. The growth of the Nakafurano, Shiwa, and Matsuyama biotypes was inhibited by imazaquin-ammonium and bispyribac-sodium, whereas the Yurihonjyo biotype grew normally after treatment with these herbicides. The herbicide concentration required to inhibit the acetolactate synthase (ALS) enzyme by 50% (I 50 ), obtained using in vivo ALS assays, indicated that the four biotypes were > 10-fold more resistant to thifensulfuron-methyl than a susceptible biotype. The Nakafurano, Shiwa, and Matsuyama biotypes exhibited no or little resistance to imazaquin-ammonium, whereas the Yurihonjyo biotype exhibited 6700-fold resistance to the herbicide. The Nakafurano and Shiwa biotypes exhibited no resistance to bispyribac-sodium, but the Matsuyama biotype exhibited 21-fold resistance and the Yurihonjyo biotype exhibited 260-fold resistance to the herbicide. Two S. juncoides ALS genes (ALS1 and ALS2) were isolated and each was found to contain one intron and to encode an ALS protein of 645 amino acids. Sequencing of the ALS genes revealed an amino acid substitution at Pro 197 in either encoded protein (ALS1 or ALS2) in the biotypes from Nakafurano (Pro 197 →Ser 197 ), Shiwa (Pro 197 →His 197 ), and Matsuyama (Pro 197 →Leu 197 ). The ALS2 of the biotype from Yurihonjyo was found to contain a Trp 574 →Leu 574 substitution. The relationships between the responses to ALS-inhibiting herbicides and the amino acid substitutions, which are consistent with previous reports in other plants, indicate that the substitutions at Pro 197 and Trp 574 are the basis of the resistance to sulfonylureas in these S. juncoides biotypes.
Identifying the host genetic factors underlying severe COVID-19 is an emerging challenge1–5. Here we conducted a genome-wide association study (GWAS) involving 2,393 cases of COVID-19 in a cohort of Japanese individuals collected during the initial waves of the pandemic, with 3,289 unaffected controls. We identified a variant on chromosome 5 at 5q35 (rs60200309-A), close to the dedicator of cytokinesis 2 gene (DOCK2), which was associated with severe COVID-19 in patients less than 65 years of age. This risk allele was prevalent in East Asian individuals but rare in Europeans, highlighting the value of genome-wide association studies in non-European populations. RNA-sequencing analysis of 473 bulk peripheral blood samples identified decreased expression of DOCK2 associated with the risk allele in these younger patients. DOCK2 expression was suppressed in patients with severe cases of COVID-19. Single-cell RNA-sequencing analysis (n = 61 individuals) identified cell-type-specific downregulation of DOCK2 and a COVID-19-specific decreasing effect of the risk allele on DOCK2 expression in non-classical monocytes. Immunohistochemistry of lung specimens from patients with severe COVID-19 pneumonia showed suppressed DOCK2 expression. Moreover, inhibition of DOCK2 function with CPYPP increased the severity of pneumonia in a Syrian hamster model of SARS-CoV-2 infection, characterized by weight loss, lung oedema, enhanced viral loads, impaired macrophage recruitment and dysregulated type I interferon responses. We conclude that DOCK2 has an important role in the host immune response to SARS-CoV-2 infection and the development of severe COVID-19, and could be further explored as a potential biomarker and/or therapeutic target.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.