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121.
We present an integration process to fabricate single-walled carbon nanotube (SWCNT) three-electrode systems on glass substrate for electrochemical biosensors. Key issues involve optimization of the SWCNT working electrode to achieve high sensitivity, developing an optimal Ag/AgCl reference electrode with good stability, and process development to integrate these electrodes. Multiple spray coatings of the SWCNT film on glass substrate enabled easier integration of the SWCNT film into an electrochemical three-electrode system. O? plasma etching and subsequent activation of spray-coated SWCNT films were needed to pattern and functionalize the SWCNT working electrode films without serious damage to the SWCNTs, and to remove organic residues. The microfabricated three-electrode systems were characterized by microscopic and spectroscopic techniques, and the electrochemical properties were investigated using cyclic voltammetry and chrono-amperometry. The fully-integrated CNT three-electrode system showed an effective working electrode area about three times larger than its geometric surface area and an improved electrochemical activity for hydrogen peroxide decomposition. Finally, the effectiveness of miniaturized pf-SWCNT electrodes as biointerfaces was examined by applying them to immunosensors to detect Legionella(L) pneumophila, based on a direct sandwich enzyme-linked immunosorbent assay (ELISA) format with 3,3',5,5'-tetramethylbenzidine dihydrochloride/hydrogen peroxide(TMB/H?O?) as the substrate/mediator system. The lower detection limit of the pf-SWCNT-based immunosensors to L. pneumophila is about 1500 times lower than that of the standard ELISA assay. 相似文献
122.
Hiroyuki Honda Kensuke Sasaki Haruhiko Minaki Kenta Masui Satoshi O. Suzuki Katsumi Doh‐ura Toru Iwaki 《Neuropathology》2012,32(2):124-132
Intraventricular infusion of pentosan polysulfate (PPS) as a treatment for various human prion diseases has been applied in Japan. To evaluate the influence of PPS treatment we performed pathological examination and biochemical analyses of PrP molecules in autopsied brains treated with PPS (one case of sporadic Creutzfeldt‐Jakob disease (sCJD, case 1), two cases of dura mater graft‐associated CJD (dCJD, cases 2 and 4), and one case of Gerstmann‐Sträussler‐Scheinker disease (GSS, case 3). Six cases of sCJD without PPS treatment were examined for comparison. Protease‐resistant PrP (PrPres) in the frontal lobe was evaluated by Western blotting after proteinase K digestion. Further, the degree of polymerization of PrP molecules was examined by the size‐exclusion gel chromatography assay. PPS infusions were started 3–10 months after disease onset, but the treatment did not achieve any clinical improvements. Postmortem examinations of the treated cases revealed symmetrical brain lesions, including neuronal loss, spongiform change and gliosis. Noteworthy was GFAP in the cortical astrocytes reduced in all treated cases despite astrogliosis. Immunohistochemistry for PrP revealed abnormal synaptic deposits in all treated cases and further plaque‐type PrP deposition in case 3 of GSS and case 4 of dCJD. Western blotting showed relatively low ratios of PrPres in case 2 of dCJD and case 3 of GSS, while in the treated sCJD (case 1), the ratio of PrPres was comparable with untreated cases. The indices of oligomeric PrP were reduced in one sCJD (case 1) and one dCJD (case 2). Although intraventricular PPS infusion might modify the accumulation of PrP oligomers in the brains of patients with prion diseases, the therapeutic effects are still uncertain. 相似文献
123.
Misun Song Young-Ah Kwon Yujin Lee Hyeran Kim Ji Hea Yun Seonwoo Kim Doh Kwan Kim 《Psychiatry investigation》2012,9(4):413-417
Objective
We compared the cell responsiveness of activated lymphocytes to rapamycin, which blocks the G1/S transition, between patients with Alzheimer''s disease (AD) and normal controls to assess the early phase control defect in cell cycle.Methods
Blood samples of 26 patients with AD and 28 normal controls were collected to separate peripheral lymphocytes. We measured the proportion of each cell cycle phase in activated lymphocytes using flow cytometry and evaluated the responsiveness of these lymphocytes to rapamycin.Results
The patients with AD were older than the normal controls (AD 74.03±7.90 yr vs. control 68.28±6.21 yr, p=0.004). The proportion of G1 phase cells in the AD group was significantly lower than that in the control group (70.29±6.32% vs. 76.03±9.05%, p=0.01), and the proportion of S phase cells in the AD group was higher than that in control group (12.45±6.09% vs. 6.03±5.11%, p=0.001). Activated lymphocytes in patients with AD were not arrested in the G1 phase and they progressed to the late phase of the cell cycle despite rapamycin treatment, in contrast to those of normal subjects.Conclusion
The patients with AD probably have a control defect of early phase cell cycle in peripheral lymphocytes that may be associated with the underlying pathology of neuronal death. 相似文献124.
Doh J Irvine DJ 《Proceedings of the National Academy of Sciences of the United States of America》2006,103(15):5700-5705
T cells are activated by recognition of foreign peptides displayed on the surface of antigen presenting cells (APCs), an event that triggers assembly of a complex microscale structure at the T cell-APC interface known as the immunological synapse (IS). It remains unresolved whether the unique physical structure of the synapse itself impacts the functional response of T cells, independent of the quantity and quality of ligands encountered by the T cell. As a first step toward addressing this question, we created multicomponent protein surfaces presenting lithographically defined patterns of tethered T cell receptor (TCR) ligands (anti-CD3 "activation sites") surrounded by a field of tethered intercellular adhesion molecule-1 (ICAM-1), as a model substrate on which T cells could be seeded to mimic T cell-APC interactions. CD4(+) T cells seeded on these surfaces polarized and migrated; on contact with activation sites, T cells assembled an IS with a structure modulated by the physical pattern of ligand encountered. On surfaces patterned with focal spots of TCR ligand, T cells stably interacted with activation sites, proliferated, and secreted cytokines. In contrast, T cells interacting with activation sites patterned to preclude centralized clustering of TCR ligand failed to form stable contacts with activation sites, exhibited aberrant PKC- clustering in a fraction of cells, and had significantly reduced production of IFN-gamma. These results suggest that focal clustering of TCR ligand characteristic of the "mature" IS may be required under some conditions for full T cell activation. 相似文献
125.
A novel fibrinogen variant (fibrinogen Seoul II; AalphaGln328Pro) characterized by impaired fibrin alpha-chain cross-linking 下载免费PDF全文
We report a novel fibrinogen variant (fibrinogen Seoul II), which has a heterozygous point mutation from CAA to CCA leading to AalphaGln328Pro. The mutation site is among several glutamine residues that serve as alpha-chain cross-linking acceptor sites. Fibrinogen Seoul II was found in a 51-year-old male patient and his family in Seoul, Korea. The patient was diagnosed with myocardial infarction at age 43. Eight years later he was admitted to the emergency room due to recurrence of the disease, where he expired under treatment with tissue plasminogen activator (t-PA). Fibrin polymerization curves, made using purified fibrinogen from the patient's relatives, showed a decreased final turbidity, suggesting Seoul II fibrin clots are composed of thinner fibers. This supposition was verified using scanning electron microscopy. Alpha-polymer formation by the mutant fibrinogen upon thrombin treatment in the presence of factor XIII and calcium was distinctly impaired. This result confirms that the residue Aalpha328 plays a pivotal role in alpha-chain cross-linking. 相似文献
126.
Seokhun Yang Bon-Kwon Koo Masahiro Hoshino Joo Myung Lee Tadashi Murai Jiesuck Park Jinlong Zhang Doyeon Hwang Eun-Seok Shin Joon-Hyung Doh Chang-Wook Nam Jianan Wang Shaoliang Chen Nobuhiro Tanaka Hitoshi Matsuo Takashi Akasaka Gilwoo Choi Kersten Petersen Jagat Narula 《JACC: Cardiovascular Imaging》2021,14(3):629-641
ObjectivesThe goal of this study was to investigate the association of stenosis and plaque features with myocardial ischemia and their prognostic implications.BackgroundVarious anatomic, functional, and morphological attributes of coronary artery disease (CAD) have been independently explored to define ischemia and prognosis.MethodsA total of 1,013 vessels with fractional flow reserve (FFR) measurement and available coronary computed tomography angiography were analyzed. Stenosis and plaque features of the target lesion and vessel were evaluated by an independent core laboratory. Relevant features associated with low FFR (≤0.80) were identified by using machine learning, and their predictability of 5-year risk of vessel-oriented composite outcome, including cardiac death, target vessel myocardial infarction, or target vessel revascularization, were evaluated.ResultsThe mean percent diameter stenosis and invasive FFR were 48.5 ± 17.4% and 0.81 ± 0.14, respectively. Machine learning interrogation identified 6 clusters for low FFR, and the most relevant feature from each cluster was minimum lumen area, percent atheroma volume, fibrofatty and necrotic core volume, plaque volume, proximal left anterior descending coronary artery lesion, and remodeling index (in order of importance). These 6 features showed predictability for low FFR (area under the receiver-operating characteristic curve: 0.797). The risk of 5-year vessel-oriented composite outcome increased with every increment of the number of 6 relevant features, and it had incremental prognostic value over percent diameter stenosis and FFR (area under the receiver-operating characteristic curve: 0.706 vs. 0.611; p = 0.031).ConclusionsSix functionally relevant features, including minimum lumen area, percent atheroma volume, fibrofatty and necrotic core volume, plaque volume, proximal left anterior descending coronary artery lesion, and remodeling index, help define the presence of myocardial ischemia and provide better prognostication in patients with CAD. (CCTA-FFR Registry for Risk Prediction; NCT04037163) 相似文献
127.
Joo Myung Lee Hyun Kuk Kim Kyung Seob Lim Jun-Kyu Park Ki Hong Choi Jonghanne Park Doyeon Hwang Tae-Min Rhee Jeong Hoon Yang Eun-Seok Shin Chang-Wook Nam Joon-Hyung Doh Joo-Yong Hahn Bon-Kwon Koo Myung Ho Jeong 《JACC: Cardiovascular Interventions》2018,11(8):717-724
Objectives
The aim of this study was to investigate the influence of microvascular damage in one vessel territory on invasively measured physiological parameters in the other vessel, using a porcine microvascular damage model.Background
Although fractional flow reserve (FFR)-guided decision-making for the nonculprit stenosis in patients with acute myocardial infarction has been reported to be better than angiography-guided revascularization, there have been debates regarding the influence of microvascular dysfunction on measured FFR in nonculprit vessels.Methods
In Yorkshire swine, microvascular damage was induced with selective intracoronary injection of microspheres (100 μm × 105 each) into the left anterior descending artery (LAD). Coronary stenosis was created in both the LAD and the left circumflex artery (LCx) using balloon catheters. Coronary physiological changes were assessed with index of microcirculatory resistance (IMR) and FFR at baseline and at each subsequent injection of microsphere up to a fifth dose in both the LAD and LCx. Measurements were repeated 5 times at each stage, and a total of 424 measurements were made in 12 Yorkshire swine models.Results
The median area stenosis in LAD and LCx was 48.1% (interquartile range: 40.8% to 50.4%) and 47.9% (interquartile range: 31.1% to 62.9%), respectively. At baseline, FFR in the LAD was lower than that in the LCx (0.89 ± 0.01 and 0.94 ± 0.01; p < 0.001). There was no difference in the IMR (18.4 ± 5.8 U and 17.9 ± 1.2 U; p = 0.847). With repeated injections of microspheres, IMR in LAD was significantly increased, up to 77.7 ± 15.7 U (p < 0.001). Given the same stenosis, FFR in the LAD was also significantly increased, up to 0.98 ± 0.01 along with IMR increase (p < 0.001). Conversely, IMR and FFR were not changed in the LCx throughout repeated injury to the LAD territory (p = 0.105 and p = 0.286 for IMR and FFR, respectively). The increase in LAD IMR was mainly driven by the increase in hyperemic mean transit time (p < 0.001).Conclusions
In Yorkshire swine models, local microvascular damage increased both FFR and IMR in a vessel supplying target myocardial territory. However, IMR and FFR were maintained in the other vessel. These physiological results in swine support the concept that FFR measurement might provide useful information for evaluating nonculprit lesions in clinical settings involving significant acute myocardial injury. 相似文献128.
129.
Seung Hun Lee MD PhD Ki Hong Choi MD Joo Myung Lee MD MPH PhD Doosup Shin MD Doyeon Hwang MD Hyun Kuk Kim MD PhD Joon-Hyung Doh MD PhD Chang-Wook Nam MD PhD Eun-Seok Shin MD PhD Mi Ja Jang RN Se Young Im MS Taek Kyu Park MD PhD Jeong Hoon Yang MD PhD Young Bin Song MD PhD Joo-Yong Hahn MD PhD Seung-Hyuk Choi MD PhD Bon-Kwon Koo MD PhD Hyeon-Cheol Gwon MD PhD 《Catheterization and cardiovascular interventions》2021,97(4):E454-E466
130.
Beng Wei Chong Rokiah Othman Ramadhansyah Putra Jaya Doh Shu Ing Xiaofeng Li Mohd Haziman Wan Ibrahim Mohd Mustafa Al Bakri Abdullah Andrei Victor Sandu Bartosz Poszaj Janusz Szmidla Tomasz Stachowiak 《Materials》2021,14(7)
Image analysis techniques are gaining popularity in the studies of civil engineering materials. However, the current established image analysis methods often require advanced machinery and strict image acquisition procedures which may be challenging in actual construction practices. In this study, we develop a simplified image analysis technique that uses images with only a digital camera and does not have a strict image acquisition regime. Mortar with 10%, 20%, 30%, and 40% pozzolanic material as cement replacement are prepared for the study. The properties of mortar are evaluated with flow table test, compressive strength test, water absorption test, and surface porosity based on the proposed image analysis technique. The experimental results show that mortar specimens with 20% processed spent bleaching earth (PSBE) achieve the highest 28-day compressive strength and lowest water absorption. The quantified image analysis results show accurate representation of mortar quality with 20% PSBE mortar having the lowest porosity. The regression analysis found strong correlations between all experimental data and the compressive strength. Hence, the developed technique is verified to be feasible as supplementary mortar properties for the study of mortar with pozzolanic material. 相似文献