Publications by authors named "Chen Yi-Chun"

Object: Oxidative stress may play a role in spontaneous intracerebral hemorrhage (ICH), but data on oxidative burden in cerebral hemorrhage are limited, and it is not clear whether oxidative markers add predictive power regarding ICH outcome beyond that of traditional factors. The authors therefore examined redox status and traditional factors in ICH patients within 3 days of hemorrhage onset to delineate redox status in ICH and investigate the predictive value with respect to 30-day functional outcome.

Methods: Sixty-four patients with ICH and 114 controls were prospectively enrolled in this study.

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The efficacy of administering a recombinant adeno-associated virus (AAV) vector encoding human IGF-1 (AAV2/1-hIGF-1) into the deep cerebellar nucleus (DCN) of a type III SMA mouse model was evaluated. High levels of IGF-1 transcripts and protein were detected in the spinal cord at 2 months post-injection demonstrating that axonal connections between the cerebellum and spinal cord were able to act as conduits for the viral vector and protein to the spinal cord. Mice treated with AAV2/1-hIGF-1 and analyzed 8 months later showed changes in endogenous Bax and Bcl-xl levels in spinal cord motor neurons that were consistent with IGF-1-mediated anti-apoptotic effects on motor neurons.

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Enterovirus 71 (EV71), a member of the Picornaviridae family, may cause serious clinical manifestations associated with the central nervous system. Enterovirus 3C protease is required for virus replication and can trigger host cell apoptosis via cleaving viral polyprotein precursor and cellular proteins, respectively. Although the role of the 3C protease in processing viral and cellular proteins has been established, very little is known about the modulation of EV71 3C function by host cellular factors.

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Development of magnetoelectric, electromechanical, and photovoltaic devices based on mixed-phase rhombohedral-tetragonal (R-T) BiFeO(3) (BFO) systems is possible only if the control of the engineered R phase variants is realized. Accordingly, we explore the mechanism of a bias induced phase transformation in this system. Single point spectroscopy demonstrates that the T → R transition is activated at lower voltages compared to T → -T polarization switching.

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La(Mg(0.5)Ti(0.5))O(3) (LMT) ceramics were prepared by either the solid-state reaction (LMT)(SS) or the citric-acid chemical method (LMT)(CA).

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We have presented a systematical study of the domain nucleation and growth behaviors in multiferroic BiFeO(3) (BFO) films. Both the ferroelectric and the ferroelastic switching dynamics were investigated. Several environmental parameters, including the polarization orientations, the monodomain-like matrix, and the ordered domain walls as local boundaries, were well controlled by thin-film strain engineering through changing the vicinal angles of the substrates.

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Aims: Taiwan has the highest incidence and prevalence of end-stage renal disease worldwide. Haptoglobin (Hp) has a role in renal protection, and there are known differences in the function of different Hp alleles. We aim to study the association between Hp genotype and chronic kidney disease (CKD) in Taiwan.

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Accumulating evidence has shown the adverse effect of long-term hyperaldosteronism on cardiovascular morbidity that is independent of blood pressure. However, the diagnosis of primary aldosteronism (PA) remains a challenge for patients who present with subtle or atypical features or have chronic kidney disease (CKD). SPECT/CT has proven valuable in the diagnosis of a number of conditions.

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Technetium-99m human serum albumin ((99m)Tc-HSA) is an important radiopharmaceutical required in nuclear medicine studies. However, the risk of transfusion-transmitted infection remains a major safety concern. Autopreparation of serum component acquired from patient provides a "personal-exclusive" source for radiolabeling.

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Synapsin is an evolutionarily conserved, presynaptic vesicular phosphoprotein. Here, we ask where and how synapsin functions in associative behavioral plasticity. Upon loss or reduction of synapsin in a deletion mutant or via RNAi, respectively, Drosophila larvae are impaired in odor-sugar associative learning.

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Methods for tagging biomolecules with fluorine 18 as immuno-positron emission tomography (immunoPET) tracers require tedious optimization of radiolabeling conditions and can consume large amounts of scarce biomolecules. We describe an improved method using a digital microfluidic droplet generation (DMDG) chip, which provides computer-controlled metering and mixing of 18F tag, biomolecule, and buffer in defined ratios, allowing rapid scouting of reaction conditions in nanoliter volumes. The identified optimized conditions were then translated to bench-scale 18F labeling of a cancer-specific engineered antibody fragments, enabling microPET imaging of tumors in xenografted mice at 0.

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Angiotensin II (AngII) mediates progression of aortic aneurysm, but the relative contribution of its type 1 (AT1) and type 2 (AT2) receptors remains unknown. We show that loss of AT2 expression accelerates the aberrant growth and rupture of the aorta in a mouse model of Marfan syndrome (MFS). The selective AT1 receptor blocker (ARB) losartan abrogated aneurysm progression in the mice; full protection required intact AT2 signaling.

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Transforming growth factor-β (TGFβ) signaling drives aneurysm progression in multiple disorders, including Marfan syndrome (MFS), and therapies that inhibit this signaling cascade are in clinical trials. TGFβ can stimulate multiple intracellular signaling pathways, but it is unclear which of these pathways drives aortic disease and, when inhibited, which result in disease amelioration. Here we show that extracellular signal-regulated kinase (ERK) 1 and 2 and Smad2 are activated in a mouse model of MFS, and both are inhibited by therapies directed against TGFβ.

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Lifetime-resolved imaging measurements of chlorophyll a fluorescence were made on leaves of avocado plants to study whether rapidly reversible ΔpH-dependent (transthylakoid H(+) concentration gradient) thermal energy dissipation (qE) and slowly reversible ΔpH-independent fluorescence quenching (qI) are modulated by lutein-epoxide and violaxanthin cycles operating in parallel. Under normal conditions (without inhibitors), analysis of the chlorophyll a fluorescence lifetime data revealed two major lifetime pools (1.5 and 0.

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Huntington's disease (HD) is a progressive neurodegenerative disease caused by an unstable CAG trinucleotide repeat expansion. The need for biomarkers of onset and progression in HD is imperative, since currently reliable outcome measures are lacking. We used two-dimensional electrophoresis and mass spectrometry to analyze the proteome profiles in cerebrospinal fluid (CSF) of 6 pairs of HD patients and controls.

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Prostate cancer associated with cadmium exposure may indicate a link between prostate specific antigen (PSA) and levels of blood cadmium (BCd) and urinary cadmium (UCd). Thus, these associations were investigated. We recruited 295 men, 50 years of age and above from a health check-up program at a health center as subjects of the study.

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To provide a behavior-based estimate of odor similarity in larval Drosophila, we use 4 recognition-type experiments: 1) We train larvae to associate an odor with food and then test whether they would regard another odor as the same as the trained one. 2) We train larvae to associate an odor with food and test whether they prefer the trained odor against a novel nontrained one. 3) We train larvae differentially to associate one odor with food, but not the other one, and test whether they prefer the rewarded against the nonrewarded odor.

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Using a combination of piezoresponse force microscopy (PFM) and phase-field modeling, we demonstrate ubiquitous formation of center-type and possible ferroelectric closure domain arrangements during polarization switching near the ferroelastic domain walls in (100) oriented rhombohedral BiFeO(3). The formation of these topological defects is determined from the vertical and lateral PFM data and confirmed from the reversible changes in surface topography. These observations provide insight into the mechanisms of tip-induced ferroelastic domain control and suggest that formation of topological defect states under the action of local defect- and tip-induced fields is much more common than previously believed.

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We present our experience in intraoperative wake-up test in a deaf-mute feminine teenager who underwent spine surgery for correction of lordoscoliosis. Inadequate comprehension of the preoperative instructions, together with higher threshold of arousal in deaf-mutism may possibly contribute to lingering of the test. The report implicated direct, painful stimulation of the tested limbs, rather than indirect cues, such as flap on the dorsum of hands would be required for performance of wake-up test in the deaf-mute patients.

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This article reports a flexible hollow nanoparticles, self-assembling from poly(N-vinylimidazole-co-N-vinylpyrrolidone)-g-poly(d,l-lactide) graft copolymers and methoxyl/functionalized-PEG-PLA diblock copolymers, as an anticancer drug doxorubicin (Dox) carrier for cancer targeting, imaging, and cancer therapy. This multifunctional hollow nanoparticle exhibited a specific on-off switch drug release behavior, owning to the pH-sensitive structure of imidazole, to release Dox in acidic surroundings (intracellular endosomes) and to capsulate Dox in neutral surroundings (blood circulation or extracellular matrix). Imaging by SPECT/CT shows that nanoparticle conjugated with folic acids ensures a high intratumoral accumulation due to the folate-binding protein (FBP)-binding effect.

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This study was designed to determine the in vitro angiogenic ability of far-infrared (FIR) radiation in the skin-derived cultured human microvascular endothelial cells and to elucidate the role of mitogen-activated protein kinases (MAPKs) in this process. The results revealed that FIR radiation from a WS(TM) TY301 FIR emitter activated p38 and extracellular signal-regulated kinase (ERK), but not Akt or c-Jun N-terminal protein kinases (JNK), and significantly promoted angiogenesis by increasing tube formation in Matrigel and the migration of cells across an eight micron polyester filter. The addition of 50 μM PD98059, a MEK inhibitor, significantly inhibited the activation of ERK and the enhanced angiogenesis; in contrast, the inhibition of p38 phosphorylation did not inhibit the enhanced angiogenesis.

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Heme oxygenase-1 (HO-1) expression, in response to various stimuli, has been generally reported to protect against cellular stress. However, we previously demonstrated simvastatin-induced HO-1-exaggerated nuclear factor kappa beta (NF-κβ) activation and superoxide production on exposure to lipopolysaccharide (LPS). The addition of the iron chelator, desferrioxamine, to reduce the accumulation of ferric iron from heme by HO-1 resulted in a blockade of aggravated superoxide production.

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Controlling the size distribution of polymer-based nanoparticles is a challenging task due to their flexible core and surface structures. To accomplish such as task requires very precise control at the molecular level. Here we demonstrate a new approach whereby uniform-sized supramolecular nanoparticles (SNPs) can be reliably generated using a digital microfluidic droplet generator (DMDG) chip.

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Using liquid slugs as microreactors and microvessels enable precise control over the conditions of their contents on short-time scales for a wide variety of applications. Particularly for screening applications, there is a need for control of slug parameters such as size and composition. We describe a new microfluidic approach for creating slugs in air, each comprising a size and composition that can be selected individually for each slug.

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