Zeolite Membrane-Based Low-Temperature Dehydrogenation of a Liquid Organic Hydrogen Carrier: A Key Step in the Development of a Hydrogen Economy.

Methylcyclohexane (MCH) dehydrogenation is an equilibrium-limited reaction that requires high temperatures (>300 °C) for complete conversion. However, high-temperature operation can degrade catalytic activity and produce unwanted side products. Thus, a hybrid zeolite membrane (Z) is prepared on the inner surface of a tubular support and used it as a wall in a membrane reactor (MR) configuration. Pt/C catalysts is packed diluted with quartz sand inside the Z-coated tube and applied the MR for MCH dehydrogenation at low temperatures (190-250 °C). Z showed a remarkable H2-permselectivity in the presence of both toluene and MCH, yielding separation factors over 350. The Z-based MR achieved higher MCH conversion (75.3% ± 0.8% at 220 °C) than the conventional packed-bed reactor (56.4% ± 0.3%) and the equilibrium state (53.2%), owing to the selective removal of H2 through Z. In summary, the hybrid zeolite MR enhances MCH dehydrogenation at low temperatures by overcoming thermodynamic limitations and improves the catalytic performance and product selectivity of the reaction.

Chemical upcycling of PVC-containing plastic wastes by thermal degradation and catalysis in a chlorine-rich environment.

Chlorine (Cl)-containing chemicals, including hydrogen chloride, generated during thermal degradation of polyvinyl chloride (PVC) and corresponding mixture impede the chemical recycling of PVC-containing plastic wastes. While upgrading plastic-derived vapors, the presence of Cl-containing chemicals may deactivate the catalysts. Accordingly, herein, catalytic upgrading of pyrolysis vapor prepared from a mixture of PVC and polyolefins is performed using a fixed-bed reactor comprising zeolites. Among the H-forms of zeolites (namely, ZSM-5, Y, ß, and chabazite) used in this study, a higher yield of gas products composed of hydrocarbons with lower carbon numbers is obtained using H-ZSM-5, thus indicating further decomposition of the pyrolysis vapor to C1-C4 hydrocarbons on it. Although the formation of aromatic compounds is better on H-ZSM-5, product distributions can be adjusted by further modifying the acidic properties via the alteration of the Si/Al molar ratio, and maximum yields of C1-C4 compounds (60.8%) and olefins (64.7%) are achieved using a Si/Al molar ratio of 50. Additionally, metal ion exchange on H-ZSM-5 is conducted, and upgrading of PVC-containing waste-derived vapor to aromatic chemicals and small hydrocarbon molecules was successfully performed using Co-substituted H-ZSM-5. It reveals that the highest yield of gas products on 1.74 wt% cobalt (Co)-substituted H-ZSM-5 is acquired via the selection of an appropriate metal and metal ion concentration adjustment. Nevertheless, introduction of excess Co into the H-ZSM-5 surface decreases the cracking activity, thereby implying that highly distributed Co is required to achieve excellent cracking activity. The addition of Co also adjusted the acid types of H-ZSM-5, and more Lewis acid sites compared to Brønsted acid sites selectively produced olefins and naphthenes over paraffins and aromatics. The proposed approach can be a feasible process to produce valuable petroleum-replacing chemicals from Cl-containing mixed plastic wastes, contributing to the closed loops for upcycling plastic wastes.

Impact of COVID-19 on ophthalmic medical access during successive waves: Demographics, disease factors, and wave locations.

BACKGROUND: The coronavirus disease (COVID-19) pandemic significantly impacted medical care, including ophthalmology. This study aimed to identify factors associated with reduced ophthalmic medical access during the pandemic. METHODS: This nationwide population-based cohort study analysed South Korean health insurance claims data from January 2019 to November 2021. Outpatient visits and surgeries for age-related macular degeneration, cataract, diabetic retinopathy, glaucoma, and retinal detachment during the two pandemic waves were compared with those in the non-pandemic period. Poisson regression was used to estimate incidence rate ratios and changes in outpatient visits and surgeries between waves concerning patient age, sex, residential location, and health insurance type. RESULTS: Outpatient visits for five eye diseases decreased in the first wave (0.733-0.985, P < 0.001). In the second wave, only outpatient visits for age-related macular degeneration, cataract, and glaucoma decreased (0.754, 0.878, and 0.874, respectively, all P < 0.001). Age-related macular degeneration, cataract, and glaucoma surgeries were significantly reduced in the first wave (0.829, P < 0.001; 0.836, P < 0.001; 0.904, P = 0.030, respectively). Age-related macular degeneration (0.852) and cataract (0.716) surgeries dropped in the second wave. Women and elderly (>65 years) patients curtailed outpatient visits and surgeries more throughout the pandemic and were less resilient during the second wave. Wave location was also related to outpatient visits and surgeries. CONCLUSIONS: The COVID-19 pandemic decreased outpatient visits and surgeries for eye diseases, with more significant impact on women, older patients, and those residing near wave locations. These findings can inform healthcare policies to minimise future pandemic impacts on healthcare delivery.

Impact of intensive rehabilitation on long-term prognosis after stroke: A Korean nationwide retrospective cohort study.

An increasing number of patients are receiving rehabilitation after stroke. But the impact of intensive rehabilitation on the long-term prognosis of patients with stroke remains to be elucidated. The purpose of this study was to identify the impact of intensive rehabilitation on the long-term prognosis of patients with stroke using data from the National Health Insurance Service database. This is a register-based, retrospective cohort study. Using data from the National Health Insurance Service database, we included the patients who received rehabilitation for stroke from 2006 to 2013. Of the 14,984 patients diagnosed with stroke, 2483 died within 1 year, and 2866 did not receive rehabilitation; hence, they were also excluded. The final sample included 9635 (49.2% men, 50.8% women) patients. After correcting for covariates, the Cox model was used to evaluate the effects of physical therapy (PT) and occupational therapy (OT) on survival. We estimated the independent contribution of each factor to the risk of death from the initiation of rehabilitation. Significant differences in mortality were observed according to age, Charlson comorbidity index (CCI), income level, and stroke type. Patients with stroke who received both PT and OT had a better long-term prognosis than those who received either treatment alone. Therapy performed by a physical therapist with more than 120 hours of training effectively improved the patients' long-term prognosis. Intensive PT and OT will help improve the long-term prognosis of patients with stroke. This study emphasizes the importance of intensive rehabilitation in these patients.

A Hybrid Zeolite Membrane-Based Breakthrough for Simultaneous CO2 Capture and CH4 Upgrading from Biogas.

Biogas is an environmentally friendly and sustainable energy resource that can substitute or complement conventional fossil fuels. For practical uses, biogas upgrading, mainly through the effective separation of CO2 (0.33 nm) and CH4 (0.38 nm), is required to meet the approximately 90-95% purity of CH4, while CO2 should be concomitantly purified. In this study, a high CO2 perm-selective zeolite membrane was synthesized by heteroepitaxially growing a chabazite (CHA) zeolite seed layer with a synthetic precursor that allowed the formation of all-silica deca-dodecasil 3 rhombohedral (DDR) zeolite (with a pore size of 0.36 × 0.44 nm2). The resulting hydrophobic DDR@CHA hybrid membrane on an asymmetric α-Al2O3 tube was thin (ca. 2 µm) and continuous, thus providing both high flux and permselectivity for CO2 irrespective of the presence or absence of water vapor (the third largest component in the biogas streams). To the best of our knowledge, the CO2 permeance of (2.9 ± 0.3) × 10-7 mol m-2 s-1 Pa-1 and CO2/CH4 separation factor of ca. 274 ± 73 at a saturated water vapor partial pressure of ca. 12 kPa at 50 °C have the highest CO2/CH4 separation performance yet achieved. Furthermore, we explored the membrane module properties of the hybrid membrane in terms of the recovery and purity of both CO2 and CH4 under dry and wet conditions. Despite the high intrinsic membrane properties of the current hybrid membrane, reflected by the high permeance and SF, the corresponding module properties indicated that high-performance separation of CO2 and CH4 for the desired biogas upgrading was achieved at a limited processing capacity. This supports the importance of understanding the correlation between the membrane and module properties, as this will provide guidance for the optimal operating conditions.

Clinical application of serological Alzheimer's disease diagnosis using a highly sensitive biosensor with hydrogel-enhanced dielectrophoretic force.

Analysis of a ratio between amyloid beta 1-40 and 1-42 (Aß1-40 and Aß1-42) presented in plasm enables a highly accurate diagnosis of Alzheimer's disease (AD). However, the analysis of plasma Aßs is not routinely conducted because of the lack of Aß detection techniques sensitive enough to specifically detect Aß from thousands of biomaterials present in the plasma. We developed a hydrogel-patterned spiral microelectrode sensor combined with a hopping dielectrophoretic (DEP) force, combining the negative DEP and positive DEP forces, for Aß detection. The hydrogel effectively increased the number of immobilized fragmented antibodies in the reaction region of the sensor and enabled size-exclusive passive filtration of non-specific plasma proteins from that region. The hopping DEP force further concentrated the Aßs and removed the non-specific plasma proteins. Consequently, our sensor achieved a limit of detection (LOD) of approximately âˆ¼ 0.15 pg/mL for both Aß1-40 and Aß1-42 in the standard plasma. Finally, comparing the ratio between Aß1-40 and Aß1-42 signals, we distinguished AD patients from cognitively normal subjects with 95.83% accuracy and 92.31% precision (n = 24, p < 0.0001, One-way ANOVA).

Multiplex SNP Genotyping Using SWITCH: Sequence-Specific Nanoparticle with Interpretative Toehold-Mediated Sequence Decoding in Hydrogel.

Single nucleotide polymorphisms (SNPs) that can alter phenotypes of individuals play a pivotal role in disease development and, more importantly, responses to therapy. However, SNP genotyping has been challenging due to the similarity of SNP alleles and their low concentration in biological samples. Sequence-specific nanoparticle with interpretative toehold-mediated sequence decoding in hydrogel (SWITCH) for multiplex SNP genotyping is presented. The encoding with gold nanoparticle probes transduces each SNP target to ≈1000 invaders with prominently different sequences between wild and mutant types, featuring polymerase chain reaction (PCR)-free amplification. Subsequently, the toehold-mediated DNA replacement in hydrogel microparticles decodes the invaders via SNP-specific fluorescence signals. The 4-plex detection of the warfarin-associated SNP targets spiked in commercially validated human serum (S1-100ML, Merck) is successfully demonstrated with excellent specificity. This work is the first technology development presenting PCR-free, multiplex SNP genotyping with a single reporting fluorophore, to the best of knowledge.

Two-Dimensional MFI Zeolite Nanosheets Exfoliated by Surfactant Assisted Solution Process.

Two-dimensional (2D) zeolite nanosheets are important for the synthesis of high flux zeolite membranes due to their lateral size in a preferred orientation. A way to obtain 2D zeolite nanosheets is to exfoliate interlocked structures generated during the hydrothermal synthesis. The mechanical and polymer assisted exfoliation process leads to mechanical damage in nanosheets and short lateral size. In the present study, polyvinylpyrrolidone (PVP) was introduced as an exfoliation agent and dispersant, so that multilamellar interlocked silicalite-1 zeolite nanosheets successfully exfoliated into a large lateral size (individual nanosheets 500~1200 nm). The good exfoliation behavior was due to the strong penetration of PVP into multilamellar nanosheets. Sonication assisted by mild milling helps PVP molecules to penetrate through the lamellar structure, contributing to the expansion of the distance between adjacent layers and thus decreasing the interactions between each layer. In addition, the stability of exfoliated nanosheets was evaluated with a series of organic solvents. The exfoliated nanosheets were well dispersed in n-butanol and stable for 30 days. Therefore, the PVP-assisted solution-based exfoliation process provides high aspect ratio MFI zeolite nanosheets in organic solvents for a long period.

Association between Moving to a High-Volume Hospital in the Capital Area and the Mortality among Patients with Cancer: A Large Population-Based Cohort Study.

This study aimed to identify the association between moving to a high-volume hospital and the mortality of patients with cancer living in the district. The study population comprised participants diagnosed with cancer within the past nine years (2004-2012). The final sample included 8197 patients with cancer, 3939 were males (48.1%), and 4258 were females (51.9%). A Cox proportional hazard model was used to estimate the hazard ratio (HR) for death. Confounding variables including sex, age, type of social security, income level, disability, and utilization volume were incorporated into the model. Among patients with cancer living in the district, 2874 (35.1%) used healthcare services in Seoul. About 10% (n = 834) of patients died during the follow-up period. The HR for death in females (HR: 0.68, 95% CI: 0.58-0.81) was lower than that in males. Additionally, the HR for the death of patients using healthcare services in Seoul (HR: 1.30, 95% CI: 1.11-1.53) was higher than those patients who did not use healthcare services in Seoul. Among patients utilizing services in the province, wealthier patients' survival probability was significantly higher than that of others. The cause of income differences should be identified, and accessibility to medical use of low-income families should be enhanced to prevent mortality of patients from cancer disparities.

Improved catalytic depolymerization of lignin waste using carbohydrate derivatives.

CARBOHYDRATE-: or sugar-derived compounds were used as environmentally friendly additives for the depolymerization of Kraft lignin waste and organosolv lignin prepared from Miscanthus giganteus. The yields of the aromatic monomers obtained from Kraft lignin increased from 5.1 to 49.2% with the addition of mannitol, while those obtained from organosolv lignin increased from 44.4 to 83.0% with the addition of sucrose. This improved lignin depolymerization was also confirmed by gel permeation chromatography and nuclear magnetic resonance spectroscopy. The above results clearly indicate the beneficial effects of carbohydrate derivatives on the lignin depolymersization process, more specifically, suggesting that the presence of carbohydrates improve the lignin depolymerization of lignocellulose, as observed for the raw lignocellulose feed.

An Extrinsic-Pore-Containing Molecular Sieve Film: A Robust, High-Throughput Membrane Filter.

MFI type zeolites with 10-membered-ring pores (ca. 0.55 nm) have the ability to separate p-xylene (ca. 0.58 nm) from its bulkier isomers. Here, we introduced non-zeolitic micropores (ca. 0.6-1.5 nm) and mesopores (ca. 2-7 nm) to a conventional microporous MFI type zeolite membrane, yielding an unprecedented hierarchical membrane structure. The uniform, embedded non-zeolitic pores decreased defect formation considerably and facilitated molecular transport, resulting in high p-xylene perm-selectivity and molar flux. Specifically, compared to a conventional, crack network-containing MFI membranes of similar thickness (ca. 1 µm), the mesoporous MFI membranes showed almost double p-xylene permeance (ca. 1.6±0.4×10-7  mol m-2 s-1 Pa-1 ) and a high p-/o-xylene separation factor (ca. 53.8±7.3 vs. 3.5±0.5 in the conventional MFI membrane) at 225 °C. The embedded non-zeolitic pores allowed for decreasing the separation performance degradation, which was apparently related to coke formation.

Smoking cessation is related to change in metabolic syndrome onset: A rural cohort study.

INTRODUCTION: Relatively few, mainly cross-sectional, studies have examined the relationship between smoking cessation and metabolic syndrome (MetS). In particular, information on smoking cessation after MetS is limited. This study aimed to investigate the probability of smoking cessation after the onset of MetS. METHODS: In this study we used cohort data from a rural area of Korea and extracted the data of 1054 smokers who were identifiable at baseline and were followed up. Of these, 1041 individuals were selected. Descriptive statistical analyses were performed to identify the basic characteristics of smokers. Multiple logistic regression was performed to determine the association between changes in MetS and smoking cessation. RESULTS: The probability of smoking cessation was 1.84 times higher in the newly developed MetS cohort than in the reference group (without MetS at any time point), and it was 1.61 times higher in the persistent MetS cohort than in the reference group, with both probabilities being significant. CONCLUSIONS: We found that patients with MetS were more likely to quit smoking than those without MetS. However, intervention is still needed, as numerous patients with MetS continued to smoke. Interventions that actively involve medical institutions or organizations are among the most effective approaches to promote smoking cessation in patients with MetS. In particular, women, farmers and current drinkers should be prioritized.

An Hetero-Epitaxially Grown Zeolite Membrane.

The secondary growth methodology to form zeolite membranes has stringent requirements for homogeneous epitaxial intergrowth of the seed layer and limits the number of accessible high-quality zeolite membranes. Despite previous reports on hetero-epitaxial growth, high-performance zeolite membranes have yet to be reported using this approach. Here, the successful hetero-epitaxial growth of highly siliceous ZSM-58 (DDR-type zeolite) films from a SSZ-13 (CHA-type zeolite) seed layer is reported. The resulting membranes show excellent CO2 perm-selectivities, having maximum CO2 /N2 and CO2 /CH4 separation factors (SFs) as high as about 17 and 279, respectively, at 30 °C. Furthermore, the hybrid membrane maintains the CO2 perm-selectivity in the presence of water vapor (the third main component in both cases), that is, CO2 /N2 SF of about 14 and CO2 /CH4 SF of about 78, respectively, at 50 °C (a representative temperature of both CO2 -containing streams).

Differences between the effects of conventional cigarettes, e-cigarettes and dual product use on urine cotinine levels.

INTRODUCTION: The goal of this study was to evaluate the differences in urine cotinine (UC) concentration based on the use of conventional cigarettes, e-cigarettes (ECs), and dual product use, and determine the use of ECs in the real world. METHODS: In total, 15099 subjects were classified into non-smokers, cigarette smokers (c-smokers), e-cigarette smokers (e-smokers), and dual users, and their UC (a classical biomarker of smoking) values were compared. Analysis of covariance (ANCOVA) was performed after adjusting for age, sex and job status to analyze the differences in UC concentration in relation to type of smoking. The reasons for using ECs and the experience of cigarette use before using ECs were analyzed. RESULTS: Of the 15099 people, 76.4% were non-smokers, 20.9% c-smokers, 2.3% dual users, and 0.4% were e-smokers. There were significant differences in UC concentration among the groups (p<0.001). The geometric mean (GM) UC concentration was 4.45 ng/mL. UC concentration was the highest among dual users (GM: 1030.5, median: 1258.9 ng/mL), followed by c-smokers (GM: 842.5, median: 1163.0 ng/mL), e-smokers (GM: 119.5, median: 309.7 ng/mL), and non-smokers (GM: 0.8, median: 0.8 ng/mL). Among the EC users, the rate of using ECs for health or social convenience was 81.9%. Among e-smokers, 11.4% had never smoked previously. CONCLUSIONS: The UC concentration was the highest among dual users. However, for the female population, the UC concentration was the highest among e-smokers. The vast majority of EC users were dual users. In addition, there were no differences in the frequency of cigarette smoking between the dual user and c-smoker groups. Consequently, EC use did not lead to a decrease in cigarette use, but did lead to an increase in UC concentration. Therefore, in the real world, dual users have higher cotinine levels than the other groups, which could indicate that they take more nicotine by cigarettes or ECs, or are more addicted than others.

The 5-Year Survival Rate of Nonsurgical Endodontic Treatment: A Population-based Cohort Study in Korea.

INTRODUCTION: The purpose of the current population-based study was to analyze the 5-year survival rate of teeth that received nonsurgical endodontic treatment. Specifically, the variables affecting the 5-year survival rates of endodontically treated teeth were analyzed. METHODS: The present study included all endodontically treated teeth reported in 2010 in the National Health Insurance Cohort database of the Republic of Korea. By tracing the dental records of the sample to the end of 2015, the 5-year survival rates of the initial root canal treatment (RCT) and re-RCT were analyzed. Gender, age, institution type, diagnosis, arch type, tooth type, number of visits, and rubber dam usage were included in the analyses as confounding variables. RESULTS: In total, 2,866,749 teeth received initial RCT, and 173,429 teeth received re-RCT. Five-year survival rates were 90.85% and 88.42%, respectively. The survival rate of teeth that received initial RCT was significantly higher than that of those that received re-RCT. Specifically, re-RCT showed a significantly higher rate of extraction within 12 months than during other intervals. Furthermore, the following characteristics significantly positively affected the 5-year tooth survival rate: being female, <20 years of age, hospital as the institution type, mandibular teeth, anterior teeth, initial RCT, and use of rubber dam. CONCLUSIONS: Because of its high 5-year survival rate, endodontic treatment is an effective method for maintaining natural teeth.

Association between health status and tooth loss in Korean adults: longitudinal results from the National Health Insurance Service-Health Examinee Cohort, 2002-2015.

PURPOSE: This study investigated the association between health status and tooth loss based on data from the National Health Insurance Service-Health Examinee Cohort in 2002-2015. METHODS: Multivariate Cox proportional hazards regression analyses were applied to a longitudinal retrospective database, which was updated and newly released in 2018, to assess the association between health status and tooth loss while adjusting for potential confounders among sociodemographic and economic factors (sex, age, household income, insurance, and presence of disability), general and oral health status (body mass index [BMI], smoking and drinking status, periodic dental visits and scaling, and brushing before sleep), and comorbid disease (hypertension, diabetes mellitus [DM], and Charlson comorbidity index [CCI]). RESULTS: Among 514,866 participants from a South Korean population, 234,247 (45.5%) participants satisfying the inclusion criteria were analyzed. In the adjusted multivariate analysis, sex, age, household income, insurance, presence of disability, BMI, smoking and drinking status, periodic scaling, tooth brushing before sleep, DM, and CCI showed statistically significant associations with the loss of at least 1 tooth. The risk of experiencing a loss of ≥4 teeth was associated with an increase in age (in those 50-59 years of age: hazard ratio [HR], 1.98; 95% confidence interval [CI], 1.93-2.03; in those 60-69 years of age: HR, 2.93; 95% CI, 2.85-3.02; and in those 70-79 years of age: HR, 2.93; 95%, CI 2.81-3.05), smoking (HR, 1.69; 95% CI, 1.65-1.73), and DM (HR, 1.43; 95% CI, 1.38-1.48). CONCLUSIONS: The results of this study showed that the risk of experiencing tooth loss was related to multiple determinants. DM and smoking were especially significantly associated with tooth loss.

Metal@SiO2 Core-Shells with Self-Arrested Migrating Core.

Developing easy and customizable strategies for the directional structure modulation of multicomponent nanosystems to influence and optimize their properties are a paramount but challenging task in nanoscience. Here, we demonstrate highly controlled eccentric off-center positioning of metal-core in metal@silica core-shells by utilizing an in situ generated biphasic silica-based intraparticle solid-solid interface. In the synthetic strategy, by including Ca2+-ions in silica-shell and successive oxidative and reductive annealing at high temperature, a unique hairline-biphasic interface is evolved via the heat-induced concentric radial segregation of calcium silicate phase at the interior and normal silica phase at the exterior of core-shell, which can effectively arrest the outwardly migrating metal-core within rubbery calcium silicate phase, affording various eccentric core-shells, where core-positions are flexibly controlled by the annealing time and amounts of initially added Ca2+-ions. In the structure-property correlation study, the strategy allows fine-tuning of dipolar interaction-based blocking temperatures and magnetic anisotropies of different eccentric core-shells as the function of variable off-center distance of magnetic core without changing the overall size of nanoparticles. This work demonstrates the discovery and potential application of biphasic solid-solid media interface in controlling the heat-induced migration of metal nanocrystals and opens the avenues for exploiting the rarely studied high-temperature solid-state nanocrystal conversion chemistry and migratory behavior for directional nanostructure engineering.

Chabazite-Type Zeolite Membranes for Effective CO2 Separation: The Role of Hydrophobicity and Defect Structure.

Chabazite (CHA)-type zeolites are promising for the separation of CO2 from larger molecules, such as N2 (relevant to postcombustion carbon capture) and CH4 (relevant to natural gas/biogas upgrading). In particular, the pore size of CHA zeolites (0.37 × 0.42 nm2) can recognize slight molecular size differences between CO2 (0.33 nm) and the larger N2 (0.364 nm) or CH4 (0.38 nm) molecules, thus allowing separation in favor of CO2 through CHA membranes. Furthermore, the siliceous constituents in the CHA zeolite can reduce the adsorption capacity toward the smaller H2O molecule (0.265 nm) and, thus, the H2O permeation rate. This is highly desirable for securing good molecular sieving ability with CO2 permselectivity in the presence of H2O vapor. Indeed, a siliceous CHA film obtained with a nominal Si/Al ratio of 100 (CHA_100) showed high CO2/N2 and CO2/CH4 separation performance, especially in the presence of H2O vapor; ∼13.4 CO2/N2 and ∼37 CO2/CH4 separation factors (SFs) at 30 °C. These SFs were higher than the corresponding values (∼5.2 CO2/CH4 SFs and ∼31 CO2/CH4 SFs) under dry conditions; such improvement could be ascribed to defect blocking by physisorbed water molecules. Finally, the contribution of molecular transport through zeolitic and nonzeolitic parts was quantitatively analyzed by combining information extracted from image processing of fluorescence confocal optical microscopy images with a one-dimensional permeation model. It appears that ∼19 and ∼20% of the total CO2 permeance for CHA_100 were reduced due to transport inhibition by the physisorbed water molecules on the membrane surface and defect, respectively.

Multifunctionalized Reduced Graphene Oxide Biosensors for Simultaneous Monitoring of Structural Changes in Amyloid-ß 40.

Determination of the conformation (monomer, oligomer, or fibril) of amyloid peptide aggregates in the human brain is essential for the diagnosis and treatment of Alzheimer's disease (AD). Accordingly, systematic investigation of amyloid conformation using analytical tools is essential for precisely quantifying the relative amounts of the three conformations of amyloid peptide. Here, we developed a reduced graphene oxide (rGO) based multiplexing biosensor that could be used to monitor the relative amounts of the three conformations of various amyloid-ß 40 (Aß40) fluids. The electrical rGO biosensor was composed of a multichannel sensor array capable of individual detection of monomers, oligomers, and fibrils in a single amyloid fluid sample. From the performance test of each sensor, we showed that this method had good analytical sensitivity (1 pg/mL) and a fairly wide dynamic range (1 pg/mL to 10 ng/mL) for each conformation of Aß40. To verify whether the rGO biosensor could be used to evaluate the relative amounts of the three conformations, various amyloid solutions (monomeric Aß40, aggregated Aß40, and disaggregated Aß40 solutions) were employed. Notably, different trends in the relative amounts of the three conformations were observed in each amyloid solution, indicating that this information could serve as an important parameter in the clinical setting. Accordingly, our analytical tool could precisely detect the relative amounts of the three conformations of Aß40 and may have potential applications as a diagnostic system for AD.

Charlson comorbidity index as a predictor of periodontal disease in elderly participants.

PURPOSE: This study investigated the validity of the Charlson comorbidity index (CCI) as a predictor of periodontal disease (PD) over a 12-year period. METHODS: Nationwide representative samples of 149,785 adults aged ≥60 years with PD (International Classification of Disease, 10th revision [ICD-10], K052-K056) were derived from the National Health Insurance Service-Elderly Cohort during 2002-2013. The degree of comorbidity was measured using the CCI (grade 0-6), including 17 diseases weighted on the basis of their association with mortality, and data were analyzed using multivariate Cox proportional-hazards regression in order to investigate the associations of comorbid diseases (CDs) with PD. RESULTS: The multivariate Cox regression analysis with adjustment for sociodemographic factors (sex, age, household income, insurance status, residence area, and health status) and CDs (acute myocardial infarction, congestive heart failure, peripheral vascular disease, cerebral vascular accident, dementia, pulmonary disease, connective tissue disorders, peptic ulcer, liver disease, diabetes, diabetes complications, paraplegia, renal disease, cancer, metastatic cancer, severe liver disease, and human immunodeficiency virus [HIV]) showed that the CCI in elderly comorbid participants was significantly and positively correlated with the presence of PD (grade 1: hazard ratio [HR], 1.11; P<0.001; grade ≥2: HR, 1.12, P<0.001). CONCLUSIONS: We demonstrated that a higher CCI was a significant predictor of greater risk for PD in the South Korean elderly population.