Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 39
Filtrar
1.
Medicina (Kaunas) ; 59(1)2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36676739

RESUMO

BACKGROUND AND OBJECTIVES: The Temperament Evaluation of Memphis, Pisa, Paris and San Diego Autoquestionnaire (TEMPS-A) is designed to assess affective temperaments. The short version of the TEMPS-A (TEMPS-A-SV) has been translated into various languages for use in research and clinical settings. However, no research has been conducted to validate the Korean version of the TEMPS-A-SV in patients with mood disorders. The goal of this study is to evaluate the reliability and validity of the TEMPS-A-SV in Korean mood disorder patients. MATERIALS AND METHODS: In this cross-sectional retrospective study, a total of 715 patients (267 patients with major depressive disorder, 94 patients with bipolar disorder I, and 354 patients with bipolar disorder II) completed the Korean TEMPS-A-SV. Cronbach's alpha and McDonald's omega were used to assess the reliability. Exploratory factor analysis (EFA) was also performed. Spearman's correlation coefficient was used to examine associations between the five temperaments. The difference in five temperament scores between the gender or diagnosis groups was analyzed, and the correlation between five temperament scores and age was tested. RESULTS: The Korean TEMPS-A-SV displayed good internal consistency (α = 0.65-0.88, ω = 0.66-0.9) and significant correlations between the subscales except one (the correlation between hyperthymic and anxious). Using EFA, a two-factor structure was produced: Factor I (cyclothymic, depressive, irritable, and anxious) and Factor II (hyperthymic). The cyclothymic temperament score differed by gender and the anxious temperament score was significantly correlated with age. All the temperaments, except for irritable temperament, showed significant differences between diagnosis groups. CONCLUSIONS: Overall, the results show that the TEMPS-A-SV is a reliable and valid measurement that can be used for estimating Koreans' affective temperaments. However, more research is required on affective temperaments and associated characteristics in people with mood disorders.


Assuntos
Transtorno Depressivo Maior , Transtornos do Humor , Humanos , Transtornos do Humor/diagnóstico , Transtornos do Humor/psicologia , Temperamento , Transtorno Depressivo Maior/diagnóstico , Reprodutibilidade dos Testes , Estudos Transversais , Paris , Estudos Retrospectivos , Inventário de Personalidade , Inquéritos e Questionários , República da Coreia
2.
Sensors (Basel) ; 21(5)2021 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-33802352

RESUMO

In this paper, we present an efficient way to find a gateway deployment for a given sensor network topology. We assume that the expired sensors and gateways can be replaced and the locations of the gateways are chosen among the given sensor nodes. The objective is to find a gateway deployment that minimizes the cost per unit time, which consists of the maintenance and installation costs. The proposed algorithm creates a cost reference and uses it to find the optimal deployment via a divide and conquer algorithm. Comparing all cases is the most reliable way to find the optimal gateway deployment, but this is practically impossible to calculate, since its computation time increases exponentially as the number of nodes increases. The method we propose increases linearly, and so is suitable for large scale networks. Additionally, compared to stochastic algorithms such as the genetic algorithm, this methodology has advantages in computational speed and accuracy for a large number of nodes. We also verify our methodology through several numerical experiments.

3.
Molecules ; 26(9)2021 Apr 23.
Artigo em Inglês | MEDLINE | ID: mdl-33922535

RESUMO

Carbon fibers, which act as reinforcements in many applications, are often obtained from polyacrylonitrile (PAN). However, their production is expensive and results in waste problems. Therefore, we focused on producing carbon fibers from lyocell, a cellulose-based material, and analyzed the effects of the process parameters on their mechanical properties and carbon yields. Lyocell was initially grafted with polyacrylamide (PAM) via electron-beam irradiation (EBI) and was subsequently stabilized and carbonized. Thermal analysis showed that PAM grafting increased the carbon yields to 20% at 1000 °C when compared to that of raw lyocell, which degraded completely at about 600 °C. Stabilization further increased this yield to 55%. The morphology of the produced carbon fibers was highly dependent on PAM concentration, with fibers obtained at concentrations ≤0.5 wt.% exhibiting clear, rigid, and round cross-sections with smooth surfaces, whereas fibers obtained from 2 and 4 wt.% showed peeling surfaces and attachment between individual fibers due to high viscosity of PAM. These features affected the mechanical properties of the fibers. In this study, carbon fibers of the highest tensile strength (1.39 GPa) were produced with 0.5 wt.% PAM, thereby establishing the feasibility of using EBI-induced PAM grafting on lyocell fabrics to produce high-performance carbon fibers with good yields.

4.
Inorg Chem ; 59(6): 3983-3992, 2020 Mar 16.
Artigo em Inglês | MEDLINE | ID: mdl-32133851

RESUMO

Hierarchically porous materials with high stability and tailorable pore characters have potential for mass transfer applications, including bulky molecule capture and separation, heterogeneous catalysis, and drug delivery. The scope of functionalities can be notably broadened by employing metal-organic framework (MOF) sheets with tunable thickness as giant molecular building blocks for self-assembly into hierarchical supramolecular porous coordination materials. However, synthesizing MOF sheets with controllable bulkiness has proved challenging for scientists. We present a rational yet unprecedented bottom-up strategy to prepare a novel two-dimensional MOF sheet [Zn(BPDI)(Py)2] (BPDI = N,N'-bis(glycinyl)pyromellitic diimide; Py = pyridine) with unusual and highly desired tunable thickness. These sheets self-organize into a unique three-dimensional supramolecular coordination material (NEU-1) with tailorable porosity. To assess its technological relevance, NEU-1c is tested as a support of amine sorbent for CO2 capture. Multichannel porous NEU-1c solves the conventional trade-off suffered by supported amine carbon dioxide adsorbents between increasing amine content and decreasing access to amine sites. Our synthesis process opens the door to novel MOF nanosheets and unique hierarchical supramolecular porous materials with tailorable porosity.

5.
Bull Math Biol ; 79(2): 277-302, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-27995380

RESUMO

We introduce a mesoscopic scale chemotaxis model for traveling wave phenomena which is induced by food metric. The organisms of this simplified kinetic model have two discrete velocity modes, [Formula: see text] and a constant tumbling rate. The main feature of the model is that the speed of organisms is constant [Formula: see text] with respect to the food metric, not the Euclidean metric. The uniqueness and the existence of the traveling wave solution of the model are obtained. Unlike the classical logarithmic model case there exist traveling waves under super-linear consumption rates and infinite population pulse-type traveling waves are obtained. Numerical simulations are also provided.


Assuntos
Quimiotaxia/fisiologia , Modelos Biológicos , Fenômenos Fisiológicos Bacterianos , Simulação por Computador , Alimentos , Cinética , Conceitos Matemáticos
6.
Acc Chem Res ; 48(10): 2680-7, 2015 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-26356307

RESUMO

Oxide supports functionalized with amine moieties have been used for decades as catalysts and chromatographic media. Owing to the recognized impact of atmospheric CO2 on global climate change, the study of the use of amine-oxide hybrid materials as CO2 sorbents has exploded in the past decade. While the majority of the work has concerned separation of CO2 from dilute mixtures such as flue gas from coal-fired power plants, it has been recognized by us and others that such supported amine materials are also perhaps uniquely suited to extract CO2 from ultradilute gas mixtures, such as ambient air. As unique, low temperature chemisorbents, they can operate under ambient conditions, spontaneously extracting CO2 from ambient air, while being regenerated under mild conditions using heat or the combination of heat and vacuum. This Account describes the evolution of our activities on the design of amine-functionalized silica materials for catalysis to the design, characterization, and utilization of these materials in CO2 separations. New materials developed in our laboratory, such as hyperbranched aminosilica materials, and previously known amine-oxide hybrid compositions, have been extensively studied for CO2 extraction from simulated ambient air (400 ppm of CO2). The role of amine type and structure (molecular, polymeric), support type and structure, the stability of the various compositions under simulated operating conditions, and the nature of the adsorbed CO2 have been investigated in detail. The requirements for an effective, practical air capture process have been outlined and the ability of amine-oxide hybrid materials to meet these needs has been discussed. Ultimately, the practicality of such a "direct air capture" process is predicated not only on the physicochemical properties of the sorbent, but also how the sorbent operates in a practical process that offers a scalable gas-solid contacting strategy. In this regard, the utility of low pressure drop monolith contactors is suggested to offer a practical mode of amine sorbent/air contacting for direct air capture.

7.
Proc Natl Acad Sci U S A ; 110(50): E4849-57, 2013 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-24277814

RESUMO

Centrosomes play an important role in various cellular processes, including spindle formation and chromosome segregation. They are composed of two orthogonally arranged centrioles, whose duplication occurs only once per cell cycle. Accurate control of centriole numbers is essential for the maintenance of genomic integrity. Although it is well appreciated that polo-like kinase 4 (Plk4) plays a central role in centriole biogenesis, how it is recruited to centrosomes and whether this step is necessary for centriole biogenesis remain largely elusive. Here we showed that Plk4 localizes to distinct subcentrosomal regions in a temporally and spatially regulated manner, and that Cep192 and Cep152 serve as two distinct scaffolds that recruit Plk4 to centrosomes in a hierarchical order. Interestingly, Cep192 and Cep152 competitively interacted with the cryptic polo box of Plk4 through their homologous N-terminal sequences containing acidic-α-helix and N/Q-rich motifs. Consistent with these observations, the expression of either one of these N-terminal fragments was sufficient to delocalize Plk4 from centrosomes. Furthermore, loss of the Cep192- or Cep152-dependent interaction with Plk4 resulted in impaired centriole duplication that led to delayed cell proliferation. Thus, the spatiotemporal regulation of Plk4 localization by two hierarchical scaffolds, Cep192 and Cep152, is critical for centriole biogenesis.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Centríolos/fisiologia , Centrossomo/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas de Ciclo Celular/genética , Centríolos/metabolismo , Proteínas Cromossômicas não Histona/genética , Clonagem Molecular , Biologia Computacional , DNA Complementar/genética , Técnica Indireta de Fluorescência para Anticorpo , Immunoblotting , Imunoprecipitação , Lentivirus , Mutagênese , Oligonucleotídeos/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA
8.
Langmuir ; 31(15): 4534-41, 2015 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-25811242

RESUMO

The CO2 adsorption characteristics of a pillared 2-dimensional porous silicate material impregnated with amine containing polymers have been investigated. It was determined that the introduction of amine polymer deteriorates the CO2 capture kinetics of the MCM-36 supported amine adsorbents compared to that of the bare material, due to the fact that with the addition of a higher loading of amine polymer the diffusion of CO2 through the 2-dimensional interlayer mesoporous channels of MCM-36 becomes greatly hindered. This pore blocking sets an upper limit to the CO2 capture performance of the polymer impregnated MCM-36 and greatly reduces the utility of using this sort of amine-solid adsorbent for carbon capture. Interestingly, these results suggest that for 2-D channel solid supports there is an optimal amine loading which is not likely to be equal to the maximum loading, and which can be determined and utilized to obtain the maximum improvement over the original materials. The study performed in this work for the MCM-36 material could therefore be applied to other porous supports to determine these optimum loadings and be used to more easily compare and contrast the alterations to capture characteristics which occur upon amine loading for a wide range of materials. It is believed this will make it more straightforward to determine which solid supports hold the promise for greatly improved capture characteristics upon amine loading and allow the field to more quickly determine avenues for fruitful development. These results also suggest the need for a new sort of support structure for amine loaded solids, one which can allow us to decouple amine loading from increasing diffusion resistance so that high amine efficiency can be maintained throughout the range of increased amine loadings.

9.
Cryobiology ; 70(2): 175-83, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25732704

RESUMO

Development of techniques for the preservation of mammalian spermatogonial stem cells (SSCs) is a critical step in commercial application of SSC based technologies, including species preservation, amplification of agriculturally valuable germ lines, and human fertility preservations. The objective of this study was to develop an efficient cryopreservation protocol for preservation of bovine SSCs using a slow freezing technique. To maximize the efficiency of SSC cryopreservation, the effects of various methods (tissue vs. cell freezing) and cryoprotective agents (trehalose, sucrose, and polyethylene glycol [PEG]) were tested. Following thawing, cells were enriched for undifferentiated spermatogonia by differential plating and evaluated for recovery rate, proliferation capacity, and apoptosis. Additionally, putative stem cell activity was assessed using SSC xenotransplantation. The recovery rate, and proliferation capacity of undifferentiated spermatogonia were significantly greater for germ cells frozen using tissue freezing methods compared to cell freezing methods. Cryopreservation in the presence of 200 mM trehalose resulted in significantly greater recovery rate, proliferation capacity, and apoptosis of germ cells compared to control. Furthermore, cryopreservation using the tissue freezing method in the presence of 200 mM trehalose resulted in the production of colonies of donor-derived germ cells after xenotransplantation into recipient mouse testes, indicating putative stem cell function. Collectively, these data indicate that cryopreservation using tissue freezing methods in the presence of 200 mM trehalose is an efficient cryopreservation protocol for bovine SSCs.


Assuntos
Células-Tronco Adultas/fisiologia , Células-Tronco Adultas/transplante , Criopreservação/métodos , Crioprotetores/farmacologia , Espermatogônias/citologia , Animais , Apoptose/efeitos dos fármacos , Apoptose/fisiologia , Bovinos , Proliferação de Células , Criopreservação/veterinária , Preservação da Fertilidade/métodos , Preservação da Fertilidade/veterinária , Congelamento/efeitos adversos , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Polietilenoglicóis/farmacologia , Espermatogônias/efeitos dos fármacos , Sacarose/farmacologia , Transplante Heterólogo , Trealose/farmacologia
10.
IEEE Trans Cybern ; PP2024 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-38949931

RESUMO

We consider a heterogeneous multiagent system for tracking multiple targets with a rigid formation on a unit sphere, where the targets and chasing agents are governed by single-and double-integrator models, respectively. To make asymptotic rendezvous between agents and their corresponding targets, we use an autonomous system consisting of attraction forces and velocity alignments. If the target's position, velocity, and acceleration information are available, we derive a multiagent system for complete rendezvous and obtain its exponential convergence result. If we have only the location and velocity information of the targets, we provide an autonomous system for practical rendezvous and the corresponding mathematical analysis. To prove the main results, we employ frame-rotation-structure decomposition for the double-integrator model and the geometric properties of a rigid formation on a sphere. We also provide numerical simulations to confirm our mathematical results and apply them to multiagent dynamics with a rigid formation that patrols the boundary line for a certain area on the sphere.

11.
IEEE Trans Cybern ; 54(5): 2901-2913, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-37022386

RESUMO

We consider the target tracking problem on a sphere with topographic structure. For a given moving target on the unit sphere, we suggest a double-integrator autonomous system of multiple agents that track the given target under the topographic influence. Through this dynamic system, we can obtain a control design for target tracking on the sphere and the adapted topographic data provides an efficient agent trajectory. The topographic information, described as a form of friction in the double-integrator system, affects the velocity and acceleration of the target and agents. The target information required by the tracking agents consists of position, velocity, and acceleration. We can obtain practical rendezvous results when agents utilize only target position and velocity information. If the acceleration data of the target is accessible, we can get the complete rendezvous result using an additional control term in the form of the Coriolis force. We provide mathematically rigorous proofs for these results and present numerical experiments that can be visually confirmed.

12.
Sci Data ; 11(1): 371, 2024 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-38605036

RESUMO

The simplified molecular-input line-entry system (SMILES) has been utilized in a variety of artificial intelligence analyses owing to its capability of representing chemical structures using line notation. However, its ease of representation is limited, which has led to the proposal of BigSMILES as an alternative method suitable for the representation of macromolecules. Nevertheless, research on BigSMILES remains limited due to its preprocessing requirements. Thus, this study proposes a conversion workflow of BigSMILES, focusing on its automated generation from SMILES representations of homopolymers. BigSMILES representations for 4,927,181 records are provided, thereby enabling its immediate use for various research and development applications. Our study presents detailed descriptions on a validation process to ensure the accuracy, interchangeability, and robustness of the conversion. Additionally, a systematic overview of utilized codes and functions that emphasizes their relevance in the context of BigSMILES generation are produced. This advancement is anticipated to significantly aid researchers and facilitate further studies in BigSMILES representation, including potential applications in deep learning and further extension to complex structures such as copolymers.

13.
Psychiatry Res ; 333: 115753, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38335777

RESUMO

Creativity is known to be heritable and exhibits familial aggregation with psychiatric disorders; however, the complex nature of their relationship has not been well-established. In the present study, we demonstrate that using an expanded and validated machine learning (ML)-based phenotyping of occupational creativity (OC) can allow us to further understand the trait of creativity, which was previously difficult to define and study. We conducted the largest genome-wide association study (GWAS) on OC with 241,736 participants from the UK Biobank and identified 25 lead variants that have not yet been reported and three candidate causal genes that were previously associated with educational attainment and psychiatric disorders. We found extensive genetic overlap between OC and psychiatric disorders with mixed effect direction through various post-GWAS analyses, including the bivariate causal mixture model. In addition, we discovered a strongly genetic correlation between our original GWAS and the GWAS adjusted for education years (rg = 0.95). Our GWAS analysis via ML-based phenotyping contributes to the understanding of the genetic architecture of creativity, which may inform genetic discovery and genetic prediction in human cognition and psychiatric disorders.


Assuntos
Estudo de Associação Genômica Ampla , Transtornos Mentais , Humanos , Predisposição Genética para Doença , Transtornos Mentais/genética , Cognição , Fenótipo , Polimorfismo de Nucleotídeo Único/genética
14.
Appl Clin Inform ; 13(4): 880-890, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-36130711

RESUMO

BACKGROUND: A computerized 12-lead electrocardiogram (ECG) can automatically generate diagnostic statements, which are helpful for clinical purposes. Standardization is required for big data analysis when using ECG data generated by different interpretation algorithms. The common data model (CDM) is a standard schema designed to overcome heterogeneity between medical data. Diagnostic statements usually contain multiple CDM concepts and also include non-essential noise information, which should be removed during CDM conversion. Existing CDM conversion tools have several limitations, such as the requirement for manual validation, inability to extract multiple CDM concepts, and inadequate noise removal. OBJECTIVES: We aim to develop a fully automated text data conversion algorithm that overcomes limitations of existing tools and manual conversion. METHODS: We used interpretations printed by 12-lead resting ECG tests from three different vendors: GE Medical Systems, Philips Medical Systems, and Nihon Kohden. For automatic mapping, we first constructed an ontology-lexicon of ECG interpretations. After clinical coding, an optimized tool for converting ECG interpretation to CDM terminology is developed using term-based text processing. RESULTS: Using the ontology-lexicon, the cosine similarity-based algorithm and rule-based hierarchical algorithm showed comparable conversion accuracy (97.8 and 99.6%, respectively), while an integrated algorithm based on a heuristic approach, ECG2CDM, demonstrated superior performance (99.9%) for datasets from three major vendors. CONCLUSION: We developed a user-friendly software that runs the ECG2CDM algorithm that is easy to use even if the user is not familiar with CDM or medical terminology. We propose that automated algorithms can be helpful for further big data analysis with an integrated and standardized ECG dataset.


Assuntos
Eletrocardiografia , Vocabulário , Algoritmos , Bases de Dados Factuais , Software
15.
Artigo em Inglês | MEDLINE | ID: mdl-36141854

RESUMO

Ambient air pollutants reportedly increase inflammatory responses associated with multiple chronic diseases. We investigated the effects of long-term exposure to ambient air pollution on high-sensitivity C-reactive protein (hs-CRP) using data from 60,581 participants enrolled in the Korean Genome and Epidemiology Study-Health Examinees Study between 2012 and 2017. Community Multiscale Air Quality System with surface data assimilation was used to estimate the participants' exposure to criteria air pollutants based on geocoded residential addresses. Long-term exposure was defined as the 2-year moving average concentrations of PM10, PM2.5, SO2, NO2, and O3. Multivariable linear and logistic regression models were utilized to estimate the percent changes in hs-CRP and odds ratios of systemic low-grade inflammation (hs-CRP > 3 mg/L) per interquartile range increment in air pollutants. We identified positive associations between hs-CRP and PM10 (% changes: 3.75 [95% CI 2.68, 4.82]), PM2.5 (3.68, [2.57, 4.81]), SO2 (1.79, [1.10, 2.48]), and NO2 (3.31, [2.12, 4.52]), while negative association was demonstrated for O3 (-3.81, [-4.96, -2.65]). Elevated risks of low-grade inflammation were associated with PM10 (odds ratio: 1.07 [95% CI 1.01, 1.13]), PM2.5 (1.08 [1.02, 1.14]), and SO2 (1.05 [1.01, 1.08]). The odds ratios reported indicated that the exposures might be risk factors for inflammatory conditions; however, they did not reflect strong associations. Our findings suggest that exposure to air pollutants may play a role in the inflammation process.


Assuntos
Poluentes Atmosféricos , Poluição do Ar , Poluentes Ambientais , Ozônio , Poluentes Atmosféricos/efeitos adversos , Poluentes Atmosféricos/análise , Poluição do Ar/efeitos adversos , Poluição do Ar/análise , Proteína C-Reativa/metabolismo , Estudos Transversais , Poeira , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Humanos , Inflamação/induzido quimicamente , Inflamação/epidemiologia , Dióxido de Nitrogênio/análise , Ozônio/efeitos adversos , Ozônio/análise , Material Particulado/efeitos adversos , Material Particulado/análise
16.
Langmuir ; 27(12): 7892-901, 2011 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-21612250

RESUMO

Nanoporous layered silicate materials contain 2D-planar sheets of nanoscopic thickness and ordered porous structure. In comparison to porous 3D-framework materials such as zeolites, they have advantages such as significantly increased surface area and decreased diffusion limitations because the layers can potentially be exfoliated or intercalated into polymers to form nanocomposite materials. These properties are particularly interesting for applications as materials for enhancing molecular selectivity and throughput in composite membranes. In this report, the swelling and surface modification chemistry of two attractive nanoporous layered silicate materials, AMH-3 and MCM-22, were studied. We first describe a method, using long-chain diamines instead of monoamines, for swelling of AMH-3 while preserving its pore structure to a greater extent during the swelling process. Then, we describe a stepwise functionalization method for functionalizing the layer surfaces of AMH-3 and MCM-22 via silane condensation reactions. The covalently attached hydrocarbon chain molecules increased the hydrophobicity of AMH-3 and MCM-22 layer surfaces and therefore allow the possibility of effectively dispersing these materials in polymer matrices for thin film/membrane applications.

17.
Environ Sci Technol ; 45(6): 2420-7, 2011 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-21323309

RESUMO

While current carbon capture and sequestration (CCS) technologies for large point sources can help address the impact of CO(2) buildup on global climate change, these technologies can at best slow the rate of increase of the atmospheric CO(2) concentration. In contrast, the direct CO(2) capture from ambient air offers the potential to be a truly carbon negative technology. We propose here that amine-based solid adsorbents have significant promise as key components of a hypothetical air capture process. Specifically, the CO(2) capture characteristics of hyperbranched aminosilica (HAS) materials are evaluated here using CO(2) mixtures that simulate ambient atmospheric concentrations (400 ppm CO(2) = "air capture") as well as more traditional conditions simulating flue gas (10% CO(2)). The air capture experiments demonstrate that the adsorption capacity of HAS adsorbents are only marginally influenced even with a significant dilution of the CO(2) concentration by a factor of 250, while capturing CO(2) reversibly without significant degradation of performance in multicyclic operation. These results suggest that solid amine-based air capture processes have the potential to be an effective approach to extracting CO(2) from the ambient air.


Assuntos
Poluentes Atmosféricos/química , Aminas/química , Dióxido de Carbono/química , Sequestro de Carbono , Adsorção , Poluentes Atmosféricos/análise , Poluição do Ar/prevenção & controle , Dióxido de Carbono/análise , Cinética , Dióxido de Silício/química
18.
Dalton Trans ; 50(9): 3145-3154, 2021 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-33543738

RESUMO

Selective separation of light hydrocarbons (LHs) and adsorption of volatile organic compounds (VOCs) remain expensive and complex scientific challenges in the petrochemical industry. Shape-selective adsorbent materials can cost-effectively face these demands. Two new porous, dynamic and amorphous metal-organic frameworks (MOFs), NEU-3 [= Zn(PMDA)(Py)2] and NEU-4 [= Fe(PMDA)(Py)2] are disclosed. These MOFs along with NEU-1c [= Zn(BPDI)(Py)2] and NEU-2 [= Fe(BPDI)(Py)2] display an electron-deficient pore surface due to predesigned π-electron-deficient ligands. They are unique smart guest-responsive materials owing to their π Lewis acidic pore surface and presumably their framework flexibility. A variety of effective adsorptions and adsorptive separations is achieved by using beds of NEU-1c, NEU-2, NEU-3 and NEU-4. Promising for further investigations into the petrochemical industry, NEU-4 shows ultrahigh benzene adsorption, recognition capability, selectivity for benzene over its analogues, and high stability and regenerability.

19.
J Reprod Dev ; 56(6): 575-82, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20657156

RESUMO

Various methods have been used to remove reactive oxygen species (ROS) generated from in vitro culture (IVC) conditions that can cause cell injury or death, including the application of low oxygen (O(2)) tension and the addition of antioxidants. The beneficial effects of antioxidants and O(2) tension on IVC of porcine embryos, however, are controversial among researchers. In this study, we sought to determine the effects and optimal concentrations of antioxidants for the development of porcine embryos in an IVC system. Specifically, we examined the synergistic effects of antioxidants on development to the blastocyst stage in a culture system supplemented with L-cysteine during IVM. Of the antioxidants tested (melatonin, glutathione (GSH), ß-mercaptoethanol (ß-ME), N-acetylcysteine (NAC) and dithiothreitol (DTT)), addition of GSH (1 mM) or ß-ME (25 µM) significantly increased development to the blastocyst stage compared with the controls without antioxidant treatment (22.2 ± 4.2% for 1 mM GSH, 25.9 ± 2.2% for 25 µM ß-ME and 12-13% for the control, P<0.05). In addition, the mean cell number per blastocyst was increased by approximately 1.7-fold in the presence of GSH or ß -ME. These GSH- and ß-ME-induced increases in development to the blastocyst stage and total cell number, however, were not mimicked by melatonin, NAC or DTT, all of which are ROS scavengers. The combination of GSH or ß-ME with L-cysteine significantly reduced high O(2) tension-induced ROS production (P<0.05). These results suggest that a combination of 1 mM GSH or 25 µM ß-ME with 1 mM L-cysteine could be used for production of high quality porcine blastocysts in IVC systems.


Assuntos
Antioxidantes/farmacologia , Blastocisto/efeitos dos fármacos , Cisteína/metabolismo , Ectogênese/efeitos dos fármacos , Técnicas de Cultura Embrionária/veterinária , Oócitos/efeitos dos fármacos , Sus scrofa/embriologia , Criação de Animais Domésticos , Animais , Blastocisto/citologia , Blastocisto/metabolismo , Contagem de Células , Sinergismo Farmacológico , Feminino , Fertilização in vitro/métodos , Fertilização in vitro/veterinária , Glutationa/farmacologia , Masculino , Mercaptoetanol/farmacologia , Oócitos/citologia , Oócitos/metabolismo , Concentração Osmolar , Estresse Oxidativo/efeitos dos fármacos , Oxigênio/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Sus scrofa/metabolismo
20.
Yeungnam Univ J Med ; 37(4): 349-355, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32942349

RESUMO

Active and prompt scale-up screening tests are essential to efficiently control the coronavirus disease 2019 (COVID-19) outbreak. The goal of this work was to identify shortcomings in the conventional screening system (CSS) implemented in the beginning of the outbreak. To overcome these shortcomings, we then introduced a novel, independently developed system called the Yeungnam University type drive-through (YU-Thru), and distributed it nationwide in Korea. This system is similar to the drive-throughs utilized by fast food restaurants. YU-Thru system has shortened the time taken to test a single person to 2-4 minutes, by completely eliminating the time required to clean and ventilate the specimen collection room. This time requirement was a major drawback of the CSS. YU-Thru system also reduced the risk of subjects and medical staff infecting one another by using a separate and closed examination system. On average, 50 to 60 tests were conducted per day when using the CSS, while now up to 350 tests per day are conducted with the YU-Thru system. We believe that the YU-Thru system has made an important contribution to the rapid detection of COVID-19 in Daegu, South Korea. Here, we will describe the YU-Thru system in detail so that other countries experiencing COVID-19 outbreaks can take advantage of this system.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA