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1.
J Proteome Res ; 23(4): 1221-1231, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38507900

RESUMO

Proteins usually execute their biological functions through interactions with other proteins and by forming macromolecular complexes, but global profiling of protein complexes directly from human tissue samples has been limited. In this study, we utilized cofractionation mass spectrometry (CF-MS) to map protein complexes within the postmortem human brain with experimental replicates. First, we used concatenated anion and cation Ion Exchange Chromatography (IEX) to separate native protein complexes in 192 fractions and then proceeded with Data-Independent Acquisition (DIA) mass spectrometry to analyze the proteins in each fraction, quantifying a total of 4,804 proteins with 3,260 overlapping in both replicates. We improved the DIA's quantitative accuracy by implementing a constant amount of bovine serum albumin (BSA) in each fraction as an internal standard. Next, advanced computational pipelines, which integrate both a database-based complex analysis and an unbiased protein-protein interaction (PPI) search, were applied to identify protein complexes and construct protein-protein interaction networks in the human brain. Our study led to the identification of 486 protein complexes and 10054 binary protein-protein interactions, which represents the first global profiling of human brain PPIs using CF-MS. Overall, this study offers a resource and tool for a wide range of human brain research, including the identification of disease-specific protein complexes in the future.


Assuntos
Proteínas , Espectrometria de Massas em Tandem , Humanos , Espectrometria de Massas em Tandem/métodos , Proteínas/química , Cromatografia Líquida de Alta Pressão/métodos , Cromatografia por Troca Iônica/métodos , Encéfalo , Proteoma/análise
2.
J Proteome Res ; 22(12): 3843-3853, 2023 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-37910662

RESUMO

Alzheimer's disease (AD) is the most prevalent form of dementia, disproportionately affecting women in disease prevalence and progression. Comprehensive analysis of the serum proteome in a common AD mouse model offers potential in identifying possible AD pathology- and gender-associated biomarkers. Here, we introduce a multiplexed, nondepleted mouse serum proteome profiling via tandem mass-tag (TMTpro) labeling. The labeled sample was separated into 475 fractions using basic reversed-phase liquid chromatography (RPLC), which were categorized into low-, medium-, and high-concentration fractions for concatenation. This concentration-dependent concatenation strategy resulted in 128 fractions for acidic RPLC-tandem mass spectrometry (MS/MS) analysis, collecting ∼5 million MS/MS scans and identifying 3972 unique proteins (3413 genes) that cover a dynamic range spanning at least 6 orders of magnitude. The differential expression analysis between wild type and the commonly used AD model (5xFAD) mice exhibited minimal significant protein alterations. However, we detected 60 statistically significant (FDR < 0.05), sex-specific proteins, including complement components, serpins, carboxylesterases, major urinary proteins, cysteine-rich secretory protein 1, pregnancy-associated murine protein 1, prolactin, amyloid P component, epidermal growth factor receptor, fibrinogen-like protein 1, and hepcidin. The results suggest that our platform possesses the sensitivity and reproducibility required to detect sex-specific differentially expressed proteins in mouse serum samples.


Assuntos
Doença de Alzheimer , Humanos , Masculino , Camundongos , Feminino , Animais , Doença de Alzheimer/metabolismo , Espectrometria de Massas em Tandem/métodos , Proteoma/análise , Reprodutibilidade dos Testes , Cromatografia de Fase Reversa
3.
Neurospine ; 20(3): 931-939, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37798987

RESUMO

OBJECTIVE: This study aimed to evaluate the treatment of spinal stenosis with spondylolisthesis using bilateral-contralateral unilateral biportal endoscopic (UBE) decompression to minimize facet joint damage. METHODS: We retrospectively evaluated 42 patients with grade 1 spondylolisthesis who underwent bilateral-contralateral UBE decompression between July 2018 and September 2019. To identify segmental instability, static and dynamic images from preoperative and postoperative procedures and final follow-up radiographs were reviewed. Lateral radiograph slippage ratio, sagittal motion, and facet joint preservation were evaluated. Clinical assessments were conducted using the visual analogue scale (VAS), Oswestry Disability Index (ODI), and modified MacNab criteria. RESULTS: The average final follow-up period was 26.5 ± 1.3 months. The average preoperative slip percentage was 15.70% ± 5.25%, which worsened to 18.80% ± 5.41% at the final follow-up (p < 0.005). The facet joint preservation rate was 95.6% ± 4.1% on the contralateral side. Improvements in the VAS scores (leg pain: from 7.9 ± 2.2 to 3.1 ± 0.7; p < 0.005; back pain: from 7.2 ± 3.0 to 2.8 ± 1.0; p < 0.005) were observed at the final follow-up. The mean preoperative ODI was 26.19 ± 3.42, which improved to 9.6 ± 1.0 (p < 0.005). Thirteen patients exhibited delayed focal segmental instability following decompression. Despite the absence of symptoms or improvement with conservative treatment in the majority of patients with delayed instability, two patients required fusion surgery to address the instability. Additionally, 2 patients developed facet synovial cysts, while 2 experienced spinous process fractures. CONCLUSION: Bilateral decompression with a contralateral UBE approach could be an effective and alternative treatment method to reduce instability in spinal stenosis with grade 1 spondylolisthesis.

4.
Polymers (Basel) ; 15(20)2023 Oct 12.
Artigo em Inglês | MEDLINE | ID: mdl-37896306

RESUMO

Fiber-type electronics is a crucial field for realizing wearable electronic devices with a wide range of sensing applications. In this paper, we begin by discussing the fabrication of fibers from conjugated polymers. We then explore the utilization of these fibers in the development of field-effect and electrochemical transistors. Finally, we investigate the diverse applications of these fiber-type transistors, encompassing chemical and physical sensors. Our paper aims to offer a comprehensive understanding of the use of conjugated polymers in fiber-type transistor-based sensors.

5.
Polymers (Basel) ; 15(16)2023 Aug 18.
Artigo em Inglês | MEDLINE | ID: mdl-37631519

RESUMO

In this study, we investigated the gas-sensing mechanism in bottom-gate organic field-effect transistors (OFETs) using poly(triarylamine) (PTAA). A comparison of different device architectures revealed that the top-contact structure exhibited superior gas-sensing performance in terms of field-effect mobility and sensitivity. The thickness of the active layer played a critical role in enhancing these parameters in the top-contact structure. Moreover, the distance and pathway for charge carriers to reach the active channel were found to significantly influence the gas response. Additionally, the surface treatment of the SiO2 dielectric with hydrophobic self-assembled mono-layers led to further improvement in the performance of the OFETs and gas sensors by effectively passivating the silanol groups. Under optimal conditions, our PTAA-based gas sensors achieved an exceptionally high response (>200%/ppm) towards NO2. These findings highlight the importance of device and interface engineering for optimizing gas-sensing properties in amorphous polymer semiconductors, offering valuable insights for the design of advanced gas sensors.

6.
Ann Intern Med ; 176(7): 934-939, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37429031

RESUMO

BACKGROUND: In previous studies, the prevalence of patent foramen ovale (PFO) has been reported to be higher in scuba divers who experienced decompression illness (DCI) than in those who did not. OBJECTIVE: To assess the association between PFO and DCI in scuba divers. DESIGN: Prospective cohort study. SETTING: Tertiary cardiac center in South Korea. PARTICIPANTS: One hundred experienced divers from 13 diving organizations who did more than 50 dives per year. MEASUREMENTS: Participants had transesophageal echocardiography with a saline bubble test to determine the presence of a PFO and were subsequently divided into high- and low-risk groups. They were followed using a self-reported questionnaire while blinded to their PFO status. All of the reported symptoms were adjudicated in a blinded manner. The primary end point of this study was PFO-related DCI. Logistic regression analysis was done to determine the odds ratio of PFO-related DCI. RESULTS: Patent foramen ovale was seen in 68 divers (37 at high risk and 31 at low risk). Patent foramen ovale-related DCI occurred in 12 divers in the PFO group (non-PFO vs. high-risk PFO vs. low-risk PFO: 0 vs. 8.4 vs. 2.0 incidences per 10 000 person-dives; P = 0.001) during a mean follow-up of 28.7 months. Multivariable analysis showed that high-risk PFO was independently associated with an increased risk for PFO-related DCI (odds ratio, 9.34 [95% CI, 1.95 to 44.88]). LIMITATION: The sample size was insufficient to assess the association between low-risk PFO and DCI. CONCLUSION: High-risk PFO was associated with an increased risk for DCI in scuba divers. This finding indicates that divers with high-risk PFO are more susceptible to DCI than what has been previously reported and should consider either refraining from diving or adhering to a conservative diving protocol. PRIMARY FUNDING SOURCE: Sejong Medical Research Institute.


Assuntos
Doença da Descompressão , Forame Oval Patente , Humanos , Forame Oval Patente/complicações , Forame Oval Patente/diagnóstico por imagem , Forame Oval Patente/epidemiologia , Doença da Descompressão/complicações , Doença da Descompressão/epidemiologia , Estudos de Coortes , Estudos Prospectivos , Descompressão/efeitos adversos
7.
ACS Omega ; 7(35): 31003-31012, 2022 Sep 06.
Artigo em Inglês | MEDLINE | ID: mdl-36092551

RESUMO

Despite a large number of existing studies about direct carbon fuel cells (DCFCs), sufficient power generation has remained a major technical challenge for the commercialization of DCFCs. This study was designed to implement the benefits of a carbon-filled porous anode developed in our recent studies in a unit cell. First, we developed a new tubular cell assembly comprising an anode, a thin matrix, and a tubular cathode with a certain number of holes in its surface. By employing a reference electrode, we measured the resistance and I-V-P characteristics of the anode, a cathode with a single hole, and the entire cell. As a result, we found that the cathode performance was degraded by resistance to ionic mass transfer, while the anode resistance was invariant (∼0.4 Ω cm2). By developing a semi-empirical current-potential model including an ion mass transport effect, we proved that the number of holes in the cathode surface is the key to the maximal utilization of the present anode. This eventually led to notable gains in the maximum power density to 205 mW cm-2 at 700 °C in experiments. Lastly, a durability test was conducted to reconfirm the effect of ionic mass transfer on the power generation over time.

8.
Trials ; 23(1): 172, 2022 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-35193640

RESUMO

BACKGROUND: Biportal endoscopic surgery has recently been performed in lumbar discectomy, with advantages over conventional surgery, such as less skin scarring and muscle damage. However, the clinical results have not been established. Although previous studies reported no difference between the biportal endoscopic and microscopic discectomy clinical results, the evidence was weak. Therefore, this study aims to evaluate the efficacy and safety of the biportal endoscopic discectomy versus the microscopic discectomy. METHODS: This prospective multicenter randomized controlled equivalence trial is designed to compare the efficacy and safety outcomes of patients who underwent lumbar discectomy using biportal endoscopy or microscopy. We will include 100 participants (50 per group) with a lumbar herniated disc. The primary outcome will be the Oswestry Disability Index (ODI) score 12 months after surgery based on a modified intention-to-treat strategy. The secondary outcomes will include the visual analog scale score for low back and lower extremity radiating pain, the ODI score, the Euro-Qol-5-Dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scar, and surgery-related variables, such as postoperative drainage, operation time, admission duration, postoperative creatine kinase, and implementation status of conversion to open surgery. Radiographic outcomes will also be analyzed using magnetic resonance imaging (MRI) or computed tomography (CT) and simple radiographs. Safety will be assessed by evaluating all adverse and severe adverse events and surgery-related effects. The participants will be assessed by a blinded assessor before surgery (baseline) and 2 weeks and 3, 6, and 12 months after surgery. DISCUSSION: This trial will be the first prospective, multicenter, randomized controlled trial to analyze the efficacy and safety of biportal endoscopic discectomy in lumbar herniated disc. This trial is designed for evaluating the equivalence of the results between biportal endoscopic and microscopic discectomy including adequate sample size, blinded analyses, and prospective registration to reduce bias. This trial will provide enough data on the effectiveness and safety of biportal endoscopic surgery and will be an important study that allows clear conclusions. TRIAL REGISTRATION: Clinical Research Information Service (cris.nih.go.kr.) ( KCT0006191 ). Registered on 27 March 2021.


Assuntos
Deslocamento do Disco Intervertebral , Disco Intervertebral , Discotomia/efeitos adversos , Discotomia/métodos , Endoscopia/efeitos adversos , Endoscopia/métodos , Humanos , Disco Intervertebral/cirurgia , Deslocamento do Disco Intervertebral/diagnóstico por imagem , Deslocamento do Disco Intervertebral/cirurgia , Vértebras Lombares/diagnóstico por imagem , Vértebras Lombares/cirurgia , Estudos Multicêntricos como Assunto , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Resultado do Tratamento
9.
Sensors (Basel) ; 22(3)2022 Feb 03.
Artigo em Inglês | MEDLINE | ID: mdl-35161915

RESUMO

A fully integrated sensor array assisted by pattern recognition algorithm has been a primary candidate for the assessment of complex vapor mixtures based on their chemical fingerprints. Diverse prototypes of electronic nose systems consisting of a multisensory device and a post processing engine have been developed. However, their precision and validity in recognizing chemical vapors are often limited by the collected database and applied classifiers. Here, we present a novel way of preparing the database and distinguishing chemical vapor mixtures with small data acquisition for chemical vapors and their mixtures of interest. The database for individual vapor analytes is expanded and the one for their mixtures is prepared in the first-order approximation. Recognition of individual target vapors of NO2, HCHO, and NH3 and their mixtures was evaluated by applying the support vector machine (SVM) classifier in different conditions of temperature and humidity. The suggested method demonstrated the recognition accuracy of 95.24%. The suggested method can pave a way to analyze gas mixtures in a variety of industrial and safety applications.


Assuntos
Monitoramento Ambiental , Gases , Nariz Eletrônico , Gases/análise , Umidade , Máquina de Vetores de Suporte
10.
Ann Lab Med ; 42(1): 96-99, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34374354

RESUMO

The sensitivity of molecular diagnostics could be affected by nucleotide variants in pathogen genes, and the sites affected by such variants should be monitored. We report a single-nucleotide variant (SNV) in the nucleocapsid (N) gene of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), i.e., G29179T, which impairs the diagnostic sensitivity of the Xpert Xpress SARS-CoV-2 assay (Cepheid, Sunnyvale, CA, USA). We observed significant differences between the threshold cycle (Ct) values for envelope (E) and N genes and confirmed the SNV as the cause of the differences using Sanger sequencing. This SNV, G29179T, is the most prevalent in Korea and is associated with the B.1.497 virus lineage, which is dominant in Korea. Clinical laboratories should be aware of the various SNVs in the SARS-CoV-2 genome and consider their potential effects on the diagnosis of coronavirus disease 2019.


Assuntos
COVID-19 , SARS-CoV-2 , Humanos , Técnicas de Diagnóstico Molecular , Nasofaringe , Nucleotídeos , Prevalência , República da Coreia , Sensibilidade e Especificidade
12.
BMC Musculoskelet Disord ; 22(1): 1056, 2021 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-34930222

RESUMO

BACKGROUND: Recent studies on biportal endoscopic spine surgery in patients with lumbar spinal stenosis have reported good clinical results. However, these studies have been limited by the small sample sizes and use of a retrospective study design. Therefore, we aim to compare the efficacy and safety of biportal endoscopic decompressive laminectomy with those of conventional decompressive laminectomy in a multicenter, prospective, randomized controlled trial. METHODS: This study will include 120 patients (60 per group, aged 20-80 years) with 1- or 2-level lumbar spinal stenosis, who will be recruited from six hospitals. The study will be conducted from July 2021 to December 2024. The primary outcome (Oswestry Disability Index at 12 months after surgery) will be evaluated through a modified intention-to-treat method. The secondary outcomes will include the following: visual analog scale score for low back and lower extremity radiating pain, EuroQol 5-dimensions score, surgery satisfaction, walking time, postoperative return to daily life period, postoperative surgical scars, and some surgery-related variables. Radiographic outcomes will be analyzed using magnetic resonance imaging or computed tomography. All outcomes will be evaluated before the surgery and at 2 weeks, 3 months, 6 months, and 12 months postoperatively. This protocol adheres to the Standard Protocol Items: Recommendations for Interventional Trials (SPIRIT) guidelines for reporting of clinical trial protocols. DISCUSSION: It is hypothesized that the efficacy and safety of biportal endoscopic and conventional decompressive laminectomy will be comparable in patients with lumbar spinal stenosis. The results of this trial will provide a high level of evidence for the efficacy and safety of the biportal endoscopic technique in patients with lumbar spinal stenosis and facilitate the development of clinical practice guidelines. Furthermore, the results of this study may indicate the feasibility of the biportal endoscopic technique for other types of spinal surgery. TRIAL REGISTRATION: The ENDO-B trial is registered at Clinical Research Information Service (CRIS, cris.nih.go.kr ) (KCT0006057; April 52,021).


Assuntos
Estenose Espinal , Humanos , Laminectomia/efeitos adversos , Estudos Multicêntricos como Assunto , Estudos Prospectivos , Ensaios Clínicos Controlados Aleatórios como Assunto , Estudos Retrospectivos , Estenose Espinal/diagnóstico por imagem , Estenose Espinal/cirurgia , Caminhada
13.
Artigo em Inglês | MEDLINE | ID: mdl-34770093

RESUMO

A single-particle mass spectrometer (SPMS) with laser ionization was constructed to determine the chemical composition of single particles in real time. The technique was evaluated using various polystyrene latex particles with different sizes (125 nm, 300 nm, 700 nm, and 1000 nm); NaCl, KCl, MgCO3, CaCO3, and Al2O3 particles with different chemical compositions; an internal mixture of NaCl and KCl; and an internal mixture of NaCl, KCl, and MgCl2 with different mixing states. The results show that the SPMS can be useful for the determination of chemical characteristics and mixing states of single particles in real time. The SPMS was then applied to obtain the chemical signatures of various combustion aerosols (diesel engine exhaust, biomass burning (rice straw), coal burning, and cooking (pork)) based on their single-particle mass spectra. Elemental carbon (EC)-rich and EC-organic carbon (OC) particles were the predominant particle types identified in diesel engine exhaust, while K-rich and EC-OC-K particles were observed among rice straw burning emissions. Only one particle type (ash-rich particles) was detected among coal burning emissions. EC-rich and EC-OC particles were observed among pork burning particles. The single-particle mass spectra of the EC or OC types of particles differed among various combustion sources. The observed chemical signatures could be useful for rapidly identifying sources of atmospheric fine particles. In addition, the detected chemical signatures of the fine particles may be used to estimate their toxicity and to better understand their effects on human health.


Assuntos
Poluentes Atmosféricos , Material Particulado , Aerossóis/análise , Poluentes Atmosféricos/análise , Carbono/análise , China , Carvão Mineral , Monitoramento Ambiental , Humanos , Tamanho da Partícula , Material Particulado/análise , Estações do Ano
14.
Rev Sci Instrum ; 92(4): 043105, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-34243378

RESUMO

Having a sub-ns response time and not requiring physical contacts to the measurement points, a voltage measurement system based on the Pockels electro-optic effect, referred to as a PE (Pockels effect)-based voltmeter, is widely used for pulsed high voltage devices such as accelerators and X-pinch systems. To correct for the misalignment of a Pockels cell and the transmittance ratio of a beam splitter, a polar-coordinate-based data analysis scheme has been proposed. This scheme also overcomes a limitation on the measurable range of a PE-based voltmeter without ambiguity and can measure the half-wave voltage of a Pockels cell. We present an improved polar-coordinate-based data analysis scheme using an ellipse fitting method, which can correct for misalignments of all the optics components of a PE-based voltmeter while keeping the advantages of the previous scheme. We show the results of the improved data analysis scheme for measuring a slowly modulated voltage up to approximately 5 kV in about 30 s and a pulsed high voltage up to 7 kV with a rise time of less than 20 ns.

15.
Nat Commun ; 12(1): 3741, 2021 06 18.
Artigo em Inglês | MEDLINE | ID: mdl-34145296

RESUMO

Despite technological advances in biomolecule detections, evaluation of molecular interactions via potentiometric devices under ion-enriched solutions has remained a long-standing problem. To avoid severe performance degradation of bioelectronics by ionic screening effects, we cover probe surfaces of field effect transistors with a single film of the supported lipid bilayer, and realize respectable potentiometric signals from receptor-ligand bindings irrespective of ionic strength of bulky solutions by placing an ion-free water layer underneath the supported lipid bilayer. High-energy X-ray reflectometry together with the circuit analysis and molecular dynamics simulation discovered biochemical findings that effective electrical signals dominantly originated from the sub-nanoscale conformational change of lipids in the course of receptor-ligand bindings. Beyond thorough analysis on the underlying mechanism at the molecular level, the proposed supported lipid bilayer-field effect transistor platform ensures the world-record level of sensitivity in molecular detection with excellent reproducibility regardless of molecular charges and environmental ionic conditions.


Assuntos
Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Bicamadas Lipídicas/química , Potenciometria/instrumentação , Potenciometria/métodos , Membrana Celular/metabolismo , Lipídeos de Membrana/metabolismo , Simulação de Dinâmica Molecular , Concentração Osmolar , Transistores Eletrônicos
16.
PLoS One ; 16(5): e0251851, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33999944

RESUMO

The purpose of this longitudinal follow-up study was to investigate the risk of ischemic stroke nationwide in patients with seropositive rheumatoid arthritis (RA) and controls who were matched in age and sex. Patient data were collected from the National Health Insurance Service (NHIS) Health Screening (HEALS) cohort. Using the International Classification of Diseases code M05 (seropositive RA), with a prescription of any disease-modifying anti-rheumatic drug (DMARD), RA was identified. A total of 2,765 patients and 13,825 control subjects were included in our study. The 12-year incidence of ischemic stroke in each group was calculated using the Kaplan-Meier method. The risk ratio of ischemic stroke was estimated using Cox proportional hazards regression. Sixty-four patients (2.31%) in the seropositive RA group and 512 (3.70%) in the control group experienced ischemic stroke (P < 0.001) during the follow-up period. The hazard ratio of ischemic stroke in the seropositive RA group was 1.32 (95% confidence interval (CI), 1.02-1.73) after adjusting for age and sex. The adjusted hazard ratio of ischemic stroke in the seropositive RA group was 1.40 (95% CI, 1.07-1.82) after adjusting for demographics and comorbid medical disorders. According to the subgroup analysis, the hazard ratios of ischemic stroke risks in the female and hypertensive subgroups were 1.44 (95% CI, 1.05-1.97) and 1.66 (95% CI, 1.16-2.38), respectively. In the non-diabetes and non-dyslipidemia subgroups, the corresponding hazard ratios of ischemic stroke were 1.47 (95% CI, 1.11-1.95) and 1.43 (95% CI, 1.07-1.91). Seropositive RA patients have an increased risk of ischemic stroke. In female, hypertension, non-diabetes, and non-dyslipidemia RA subgroups, even without the traditional risk factors for stroke (except for hypertension), increased the risk, which could be potentially attributed to RA.


Assuntos
Artrite Reumatoide/epidemiologia , Isquemia Encefálica/epidemiologia , Diabetes Mellitus/epidemiologia , AVC Isquêmico/epidemiologia , Adulto , Idoso , Antirreumáticos , Artrite Reumatoide/sangue , Artrite Reumatoide/complicações , Artrite Reumatoide/patologia , Isquemia Encefálica/sangue , Isquemia Encefálica/patologia , Diabetes Mellitus/sangue , Diabetes Mellitus/patologia , Dislipidemias/sangue , Dislipidemias/epidemiologia , Dislipidemias/patologia , Feminino , Humanos , Hipertensão/sangue , Hipertensão/complicações , Hipertensão/epidemiologia , Hipertensão/patologia , Seguro Saúde , AVC Isquêmico/sangue , AVC Isquêmico/complicações , AVC Isquêmico/patologia , Estimativa de Kaplan-Meier , Coreia (Geográfico)/epidemiologia , Masculino , Pessoa de Meia-Idade , Modelos de Riscos Proporcionais , Fatores de Risco
17.
Rev Sci Instrum ; 92(3): 033520, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33819990

RESUMO

The Single Crystal Dispersion Interferometer (SCDI) is a newly developed dispersion interferometer (DI) system installed on KSTAR and has obtained the first data successfully in January 2020. Unlike conventional heterodyne DI systems, which use two nonlinear crystals, only one nonlinear crystal is used to eliminate the difficulty in overlapping the first and second harmonic beams, aligning and focusing the beams to a small aperture of the second nonlinear crystal, and resolving a problem of significant efforts to maintain the beam alignment to the second nonlinear crystal after a long beam transmission. The second nonlinear crystal is replaced by a frequency doubler, a simple electronic component. To infer a line integrated electron density with its associated uncertainty consistent with the measured data, we develop a forward model of the KSTAR SCDI that can be used as a likelihood within a Bayesian-based data analysis routine. The forward model consists of two main parts, which are an optical system and an electronics system, and it takes into account noises by modeling the mechanical vibrations and the electronic noises as Gaussian distributions, while the photon noise is modeled with a Poisson distribution. The developed forward model can be used for designing and improving the SCDI system.

18.
Rev Sci Instrum ; 92(3): 033536, 2021 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-33820011

RESUMO

Dispersion interferometers have been used to measure line integrated electron densities from many fusion devices. To optically suppress noise due to mechanical vibrations, a conventional dispersion interferometer typically uses two nonlinear crystals located before and after the plasma along the laser beam path. Due to the long beam path, it can be difficult to overlap the fundamental and second harmonic laser beams for a heterodyne dispersion interferometer and to focus the beams on the second nonlinear crystal located after the plasma, especially when the aperture of the nonlinear crystal is small, i.e., of the order of mm. To overcome such difficulties, a new concept of a heterodyne dispersion interferometer, a single crystal dispersion interferometer (SCDI), is developed and installed on KSTAR with the laser wavelength of 1064 nm. The concept and the optical setup of the KSTAR SCDI are discussed, as well as its first measurement during a shattered pellet injection that produces abrupt and large changes in the electron density. To demonstrate feasibility, the KSTAR SCDI measurements are also compared with those from the existing two-color interferometer.

19.
ACS Omega ; 6(8): 5962-5971, 2021 Mar 02.
Artigo em Inglês | MEDLINE | ID: mdl-33681634

RESUMO

Previous research findings and experiential accounts have provided evidence that specific components of coal ash play a catalytic role in the dry desulfurization of flue gas such that their contributions need to be considered for determining the optimal amount of desulfurizing agent such as limestone. The purpose of this study was to quantify the desulfurization characteristics of coal ash in a 500 MW pulverized coal combustion (PC) boiler as well as a 1000 MW circulating fluidized bed combustion (CFBC) boiler. In parallel with a year-long data collection of coal blends and emission characteristics, a series of temperature-controlled fixed bed (lab scale) experiments were conducted for 11 individual (but representative) coal samples. The results indicated that desulfurization by fly ashes appeared to proceed roughly in proportion to the total alkali (TA) contents of the ash, which were consistent with our preliminary test result of the CFBC boiler. In the PC boiler, however, the desulfurization reaction seemed to be very kinetically limited, apparently deactivating the TA components. We developed a practical equation for a priori prediction of SO2 concentration based on the sulfur content of coal blends.

20.
J Neurosurg Spine ; 34(4): 564-572, 2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33450734

RESUMO

OBJECTIVE: Whereas the benefits of indirect decompression after lateral lumbar interbody fusion are well known, the effects of anterior lumbar interbody fusion (ALIF) have not yet been verified. The purpose of this study was to evaluate the clinical and radiological effects of indirect decompression after ALIF for central spinal canal stenosis. In this report, along with the many advantages of the anterior approach, the authors share cases with good outcomes that they have encountered. METHODS: The authors performed a retrospective analysis of 64 consecutive patients who underwent ALIF for central spinal canal stenosis with instability and mixed foraminal stenosis between January 2015 and December 2018 at their hospital. Clinical assessments were performed using the visual analog scale score, the Oswestry Disability Index, and the modified Macnab criteria. The radiographic parameters were determined from pre- and postoperative cross-sectional MRI scans of the spinal canal and were compared to evaluate neural decompression after ALIF. The average follow-up period was 23.3 ± 1.3 months. RESULTS: All clinical parameters, including the visual analog scale score, Oswestry Disability Index, and modified Macnab criteria, improved significantly. The mean operative duration was 254.8 ± 60.8 minutes, and the intraoperative bleeding volume was 179.8 ± 119.3 ml. In the radiological evaluation, radiological parameters of the cross-sections of the spinal canal showed substantial development. The spinal canal size improved by an average of 43.3% (p < 0.001) after surgery. No major complications occurred; however, aspiration guided by ultrasonography was performed in 2 patients because of a pseudocyst and fluid collection. CONCLUSIONS: ALIF can serve as a suitable alternative to extensive posterior approaches. The authors suggest that ALIF can be used for decompression in central spinal canal stenosis as well as restoration of the foraminal dimensions, thus allowing decompression of the nerve roots.


Assuntos
Constrição Patológica/cirurgia , Vértebras Lombares/cirurgia , Região Lombossacral/cirurgia , Estenose Espinal/cirurgia , Adulto , Idoso , Constrição Patológica/patologia , Estudos Transversais , Descompressão Cirúrgica/métodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Radiografia/métodos , Canal Medular/cirurgia , Fusão Vertebral/métodos , Estenose Espinal/patologia
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