932 research outputs found
Biocompatible Poly(catecholamine)-Film Electrode for Potentiometric Cell Sensing
Surface-coated poly(catecholamine) (pCA) films have attracted attention as biomaterial interfaces owing to their biocompatible and physicochemical characteristics. In this paper, we report that pCA-film-coated electrodes are useful for potentiometric biosensing devices. Four different types of pCA film—L-dopa, dopamine, norepinephrine, and epinephrine—with thicknesses in the range of 7–27 nm were electropolymerized by oxidation on Au electrodes by using cyclic voltammetry. By using the pCA-film electrodes, the pH responsivities were found to be 39.3 to 47.7 mV/pH within the pH range of 1.68 to 10.01 on the basis of the equilibrium reaction with hydrogen ions and the functional groups of the pCAs. The pCA films suppressed nonspecific signals generated by other ions (Na+, K+, Ca2+) and proteins such as albumin. Thus, the pCA-film electrodes can be used in pH-sensitive and pH-selective biosensors. HeLa cells were cultivated on the surface of the pCA-film electrodes to monitor cellular activities. The surface potential of the pCA-film electrodes changed markedly because of cellular activity; therefore, the change in the hydrogen ion concentration around the cell/pCA-film interface could be monitored in real time. This was caused by carbon dioxide or lactic acid that is generated by cellular respiration and dissolves in the culture medium, resulting in the change of hydrogen concentration. pCA-film electrodes are suitable for use in biocompatible and pH-responsive biosensors, enabling the more selective detection of biological phenomena
An analysis method for flavan-3-ols using high performance liquid chromatography coupled with a fluorescence detector
Procyanidins belong to a family of flavan-3-ols, which consist of monomers, (+)-catechin and (-)-epicatechin, and their oligomers and polymers, and are distributed in many plant-derived foods. Procyanidins are reported to have many beneficial physiological activities, such as antihypertensive and anticancer effects. However, the bioavailability of procyanidins is not well understood owing to a lack of convenient and high-sensitive analysis methods. The aim of this study was to develop an improved method for determining procyanidin content in both food materials and biological samples. High performance liquid chromatography (HPLC) coupled with a fluorescence detector was used in this study. The limits of detection (LODs) of (+)-catechin, (-)-epicatechin, procyanidin B2, procyanidin C1, and cinnamtannin A2 were 3.0 x 10(-3) ng, 4.0 x 10(-3) ng, 14.0 x 10(-3) ng, 18.5 x 10(-3) ng, and 23.0 x 10(-3) ng, respectively; the limits of quantification (LOQs) were 10.0 x 10(-3) ng, 29.0 x 10(-3) ng, 28.5 x 10(-3) ng, 54.1 x 10(-3) ng, and 115.0 x 10(-3) ng, respectively. The LOD and LOQ values indicated that the sensitivity of the fluorescence detector method was around 1000 times higher than that of conventional HPLC coupled with a UV-detector. We applied the developed method to measure procyanidins in black soybean seed coat extract (BE) prepared from soybeans grown under three different fertilization conditions, namely, conventional farming, basal manure application, and intertillage. The amount of flavan-3-ols in these BEs decreased in the order intertillage > basal manure application > conventional farming. Commercially available BE was orally administered to mice at a dose of 250 mg/kg body weight, and we measured the blood flavan-3-ol content. Data from plasma analysis indicated that up to the tetramer oligomerization, procyanidins were detectable and flavan-3-ols mainly existed in conjugated forms in the plasma. In conclusion, we developed a highly sensitive and convenient analytical method for the analysis of flavan-3-ols, and applied this technique to investigate the bioavailability of flavan-3-ols in biological samples and to measure flavan-3-ol content in food material and plants
Bone regeneration of induced pluripotent stem cells derived from peripheral blood cells in collagen sponge scaffolds
Stem cell-based regeneration therapy offers new therapeutic options for patients with bone defects because of significant advances in stem cell research. Although bone marrow mesenchymal stem cells are the ideal material for bone regeneration therapy using stem cell, they are difficult to obtain. Induced pluripotent stem cells (iPSCs) are now considered an attractive tool in bone tissue engineering. Recently, the efficiency of establishing iPSCs has been improved by the use of the Sendai virus vector, and it has become easier to establish iPSCs from several type of somatic cells. In our previous study, we reported a method to purify osteogenic cells from iPSCs. Objective: This study aimed to evaluate the osteogenic ability of iPSCs derived from peripheral blood cells. Methodology: Mononuclear cells (MNCs) were obtained from human peripheral blood. Subsequently, T cells were selectively obtained from these MNCs and iPSCs were established using Sendai virus vectors. Established iPSCs were evaluated by the expression of undifferentiated markers and teratoma formation assays. Osteoblasts were induced from these iPSCs and evaluated by the expression of osteoblast markers. Additionally, the induced osteoblasts were transplanted into rat critical size calvaria bone defect models with collagen sponge scaffolds. Samples were evaluated by radiographical and histological assessments. Results: Induced osteoblasts expressed several osteoblast-specific markers. The results of radiographical and histological assessments revealed that the cell transplant group had bone formations superior to those of the control group. Conclusions: This study suggests that peripheral blood MNCs have the potential to differentiate into osteoblasts. Although there are some hurdles in iPSC transplantation, osteoblasts obtained from MNC-iPSCs could be applied to bone regeneration therapy in the future
JVNV: A Corpus of Japanese Emotional Speech with Verbal Content and Nonverbal Expressions
We present the JVNV, a Japanese emotional speech corpus with verbal content
and nonverbal vocalizations whose scripts are generated by a large-scale
language model. Existing emotional speech corpora lack not only proper
emotional scripts but also nonverbal vocalizations (NVs) that are essential
expressions in spoken language to express emotions. We propose an automatic
script generation method to produce emotional scripts by providing seed words
with sentiment polarity and phrases of nonverbal vocalizations to ChatGPT using
prompt engineering. We select 514 scripts with balanced phoneme coverage from
the generated candidate scripts with the assistance of emotion confidence
scores and language fluency scores. We demonstrate the effectiveness of JVNV by
showing that JVNV has better phoneme coverage and emotion recognizability than
previous Japanese emotional speech corpora. We then benchmark JVNV on emotional
text-to-speech synthesis using discrete codes to represent NVs. We show that
there still exists a gap between the performance of synthesizing read-aloud
speech and emotional speech, and adding NVs in the speech makes the task even
harder, which brings new challenges for this task and makes JVNV a valuable
resource for relevant works in the future. To our best knowledge, JVNV is the
first speech corpus that generates scripts automatically using large language
models
Achievements and Challenges of Long-Distance Race Classes Focusing on Competition: Focusing on the Positive Change in Junior High School Students’ Attitudes towards Long-Distance Races
In this study, we conducted long-distance race classes focusing on competition (Takashima et al., 2017) for junior high school students. The purposes of this study were to analyze whether students’ attitudes toward long-distance races became more positive and the determinants of this change, as well as to consider achievements and challenges of the long-distance race classes focusing on competition. The results are summarized as follows. (1) The students’ attitudes toward long-distance races became more positive, with significant pre-post differences (p<0.05). As a factor behind this finding, in the review after the classes, 60% of students responded that “classes were enjoyable overall,” so it can be said that they were able to experience the enjoyment of competition in the classes. (2) The two methods devised in this study were effective for urging students to proactively engage in long-distance race classes. (3) After the classes, 33% of the students answered, “I don’t like long-distance races.” Thus, it seems that the experience of pleasures from competition were insufficient to compensate for the physical distress of long-distance races
Natural history of medium-sized atrial septal defect in pediatric cases
AbstractBackgroundThe indication for surgical repair of atrial septal defect (ASD) is pulmonary to systemic blood flow ratio (Qp/Qs)>2.0, and therapeutic strategy depends on the facility in cases of Qp/Qs 1.5–2.0. Defect size increases with age, but hemodynamic changes of medium-sized ASD (Qp/Qs 1.5–2.0) are unknown.Methods and resultsFrom April 1, 1985 to March 31, 2008, we experienced 125 cases of cardiac catheterization for ASD. Twelve cases were re-evaluated without surgical repair. The first and second catheterizations were performed at median ages of 7 years (range, 2–13 years) and 16 years (range, 5–19 years), respectively. The mean follow-up period was 7 years. Qp/Qs increased from 1.6 to 2.0 during follow-up (p<0.05). Of four cases with Qp/Qs<1.5 at initial presentation, three had Qp/Qs≥1.5 at second inspection. Right ventricle diastolic volume (RVEDV/LVEDV) also increased.ConclusionsQp/Qs and RVEDV/LVEDV of medium-sized ASD increase together in childhood. Re-evaluation before adulthood should be considered in patients with no indications of ASD closure in childhood
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