Effect of Thermal Oxidation of Carbon Nanotubes during Wet Spinning into Fibers Using Sodium Cholate Surfactant in Aqueous Dispersion.

Surfactant-based wet spinning is a promising route toward the eco-friendly production of carbon nanotube fibers (CNTFs). However, currently, the properties of surfactant-based wet-spun CNTFs lag behind those produced by other methods, indicating the need for further understanding and research. Here, we explored the surface characteristics of carbon nanotubes (CNTs) that are advantageous for the properties of CNTFs produced by wet spinning, using sodium cholate as a surfactant. Our finding indicates that appropriate thermal oxidation of CNTs enhances the fiber properties, while excessive oxidation undermines them. This implies that the bonding mechanism between CNTs and sodium cholate involves hydrophobic interaction and π-π interaction. Therefore, it is crucial to preserve a clean surface of CNTs in wet spinning using sodium cholate. We believe our research will contribute to the advancement of surfactant-based wet spinning of CNTFs.

Impact of cardiac rehabilitation on ventricular-arterial coupling and left ventricular function in patients with acute myocardial infarction.

To maintain efficient myocardial function, optimal coordination between ventricular contraction and the arterial system is required. Exercise-based cardiac rehabilitation (CR) has been demonstrated to improve left ventricular (LV) function. This study aimed to investigate the impact of CR on ventricular-arterial coupling (VAC) and its components, as well as their associations with changes in LV function in patients with acute myocardial infarction (AMI) and preserved or mildly reduced ejection fraction (EF). Effective arterial elastance (EA) and index (EAI) were calculated from the stroke volume and brachial systolic blood pressure. Effective LV end-systolic elastance (ELV) and index (ELVI) were obtained using the single-beat method. The characteristic impedance (Zc) of the aortic root was calculated after Fourier transformation of both aortic pressure and flow waveforms. Pulse wave separation analysis was performed to obtain the reflection magnitude (RM). An exercise-based, outpatient cardiac rehabilitation (CR) program was administered for up to 6 months. Twenty-nine patients were studied. However, eight patients declined to participate in the CR program and were subsequently classified as the non-CR group. At baseline, E' velocity showed significant associations with EAI (beta -0.393; P = 0.027) and VAC (beta -0.375; P = 0.037). There were also significant associations of LV global longitudinal strain (LV GLS) with EAI (beta 0.467; P = 0.011). Follow-up studies after a minimum of 6 months demonstrated a significant increase in E' velocity (P = 0.035), improved EF (P = 0.010), and LV GLS (P = 0.001), and a decreased EAI (P = 0.025) only in the CR group. Changes in E' velocity were significantly associated with changes in EAI (beta -0.424; P = 0.033). Increased aortic afterload and VA mismatch were associated with a negative impact on both LV diastolic and systolic function. The outpatient CR program effectively decreased aortic afterload and improved LV diastolic and systolic dysfunction in patients with AMI and preserved or mildly reduced EF.

Biomedical Applications of CNT-Based Fibers.

Carbon nanotubes (CNTs) have been regarded as emerging materials in various applications. However, the range of biomedical applications is limited due to the aggregation and potential toxicity of powder-type CNTs. To overcome these issues, techniques to assemble them into various macroscopic structures, such as one-dimensional fibers, two-dimensional films, and three-dimensional aerogels, have been developed. Among them, carbon nanotube fiber (CNTF) is a one-dimensional aggregate of CNTs, which can be used to solve the potential toxicity problem of individual CNTs. Furthermore, since it has unique properties due to the one-dimensional nature of CNTs, CNTF has beneficial potential for biomedical applications. This review summarizes the biomedical applications using CNTF, such as the detection of biomolecules or signals for biosensors, strain sensors for wearable healthcare devices, and tissue engineering for regenerating human tissues. In addition, by considering the challenges and perspectives of CNTF for biomedical applications, the feasibility of CNTF in biomedical applications is discussed.

All-in-one IQ toggle switches with high versatilities for fine-tuning of transgene expression in mammalian cells and tissues.

The transgene toggling device is recognized as a powerful tool for gene- and cell-based biological research and precision medicine. However, many of these devices often operate in binary mode, exhibit unacceptable leakiness, suffer from transgene silencing, show cytotoxicity, and have low potency. Here, we present a novel transgene switch, SIQ, wherein all the elements for gene toggling are packed into a single vector. SIQ has superior potency in inducing transgene expression in response to tebufenozide compared with the Gal4/UAS system, while completely avoiding transgene leakiness. Additionally, the ease and versatility of SIQ make it possible with a single construct to perform transient transfection, establish stable cell lines by targeting a predetermined genomic locus, and simultaneously produce adenovirus for transduction into cells and mammalian tissues. Furthermore, we integrated a cumate switch into SIQ, called SIQmate, to operate a Boolean AND logic gate, enabling swift toggling-off of the transgene after the removal of chemical inducers, tebufenozide and cumate. Both SIQ and SIQmate offer precise transgene toggling, making them adjustable for various researches, including synthetic biology, genome engineering, and therapeutics.

Bayesian Optimization of Wet-Impregnated Co-Mo/Al2O3 Catalyst for Maximizing the Yield of Carbon Nanotube Synthesis.

Multimetallic catalysts have demonstrated their high potential for the controlled synthesis of carbon nanotubes (CNTs), but their development requires a more complicated optimization than that of monometallic catalysts. Here, we employed Bayesian optimization (BO) to optimize the preparation of Co-Mo/Al2O3 catalyst using wet impregnation, with the goal of maximizing carbon yield in the chemical vapor deposition (CVD) synthesis of CNTs. In the catalyst preparation process, we selected four parameters to optimize: the weight percentage of metal, the ratio of Co to Mo in the catalyst, the drying temperature, and the calcination temperature. We ran two parallel BO processes to compare the performance of two types of acquisitions: expected improvement (EI), which does not consider noise, and one-shot knowledge gradient (OKG), which takes noise into account. As a result, both acquisition functions successfully optimized the carbon yield with similar performance. The result suggests that the use of EI, which has a lower computational load, is acceptable if the system has sufficient robustness. The investigation of the contour plots showed that the addition of Mo has a negative effect on carbon yield.

The effect of home-based cardiac rehabilitation on arterial stiffness and peak oxygen consumption in patients with myocardial infarction.

Objectives: This study aims to investigate the effectiveness of home-based cardiac rehabilitation (CR) on arterial stiffness in patients with acute myocardial infarction (AMI). Patients and methods: Between January 2015 and December 2017, a total of 135 patients (120 males, 15 females; mean age: 58.8±11.1 years) with AMI who were referred for CR were included. Home-based CR was prescribed based on a cardiopulmonary exercise test (CPET) for at least six months. All patients completed three consecutive CPETs and brachial-ankle pulse wave velocity (baPWV) measurements at one, four, and seven months after onset. Results: After six months of CR, there was an improvement in peak oxygen consumption (pVO2) (Month 1, 28.7±6.4 mL/kg/min; Month 4, 31.6±6.3 mL/kg/min; Month 7, 31.2±7.1 mL/kg/min, p<0.001) and a reduction in baPWV (Month 1, left, 1546.0±311.2 cm/sec, right 1545.5±301.5 cm/sec; Month 4, left, 1374.9±282.5 cm/sec, right 1371.6±287.5 cm/sec; Month 7, left, 1362.9±287.0 cm/sec, right 1365.5±281.1 cm/sec, p<0.001). Conclusion: In patients with AMI, arterial stiffness and aerobic capacity improved after six months of home-based CR, particularly in the early stages of rehabilitation. These results suggest that changes in baPWV are useful in determining the effectiveness of CR and pVO2 in the initial stages of CR.