•PFOA and PFOS reduced egg production in fish.•PFOA and PFOS changed in transcription and protein levels of vitellogenin.•PFOA and PFOS have modes of estrogenic and anti-estrogenic actions in fish, ...respectively.
Perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS) have widely and frequently used in many industrial sectors, and thus have been frequently found in the environment. These chemicals may act as endocrine disrupting chemicals (EDCs), although the molecular mechanisms are still debated. In this study, Japanese medaka (Oryzias latipes) were exposed to 10 mg/l PFOA and 1 mg/l PFOS for 21 days, and the reproductive responses, such as the fecundity, secondary sexual characteristics and transcriptional levels of vitellogenin (vtg1 and vtg2) and choriogenin (chgh, chghm and chgl), were time-dependently evaluated (day 7, 14 and 21). PFOA and PFOS significantly reduced fecundity, and caused expression changes in the genes with time, although the patterns were different for each chemical and each sex. Different transcriptional regulations of vitellogenin and choriogenin in male suggest that PFOA and PFOS have different mode of actions in reproductive effects despite their similar chemical structure.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Tissue regeneration includes delivering specific types of cells or cell products to injured tissues or organs for restoration of tissue and organ function. Stem cell therapy has drawn considerable ...attention since transplantation of stem cells can overcome the limitations of autologous transplantation of patient's tissues; however, it is not perfect for treating diseases. To overcome the hurdles associated with stem cell therapy, tissue engineering techniques have been developed. Development of stem cell technology in combination with tissue engineering has opened new ways of producing engineered tissue substitutes. Several studies have shown that this combination of tissue engineering and stem cell technologies enhances cell viability, differentiation, and therapeutic efficacy of transplanted stem cells.
Stem cells that can be used for tissue regeneration include mesenchymal stem cells, embryonic stem cells, and induced pluripotent stem cells. Transplantation of stem cells alone into injured tissues exhibited low therapeutic efficacy due to poor viability and diminished regenerative activity of transplanted cells. In this review, we will discuss the progress of biomedical engineering, including scaffolds, biomaterials, and tissue engineering techniques to overcome the low therapeutic efficacy of stem cells and to treat human diseases.
The combination of stem cell and tissue engineering techniques overcomes the limitations of stem cells in therapy of human diseases, and presents a new path toward regeneration of injured tissues.
3D cell-printing technique has been under spotlight as an appealing biofabrication platform due to its ability to precisely pattern living cells in pre-defined spatial locations. In skin tissue ...engineering, a major remaining challenge is to seek for a suitable source of bioink capable of supporting and stimulating printed cells for tissue development. However, current bioinks for skin printing rely on homogeneous biomaterials, which has several shortcomings such as insufficient mechanical properties and recapitulation of microenvironment. In this study, we investigated the capability of skin-derived extracellular matrix (S-dECM) bioink for 3D cell printing-based skin tissue engineering. S-dECM was for the first time formulated as a printable material and retained the major ECM compositions of skin as well as favorable growth factors and cytokines. This bioink was used to print a full thickness 3D human skin model. The matured 3D cell-printed skin tissue using S-dECM bioink was stabilized with minimal shrinkage, whereas the collagen-based skin tissue was significantly contracted during in vitro tissue culture. This physical stabilization and the tissue-specific microenvironment from our bioink improved epidermal organization, dermal ECM secretion, and barrier function. We further used this bioink to print 3D pre-vascularized skin patch able to promote in vivo wound healing. In vivo results revealed that endothelial progenitor cells (EPCs)-laden 3D-printed skin patch together with adipose-derived stem cells (ASCs) accelerates wound closure, re-epithelization, and neovascularization as well as blood flow. We envision that the results of this paper can provide an insightful step towards the next generation source for bioink manufacturing.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK, ZRSKP
A real-time humidity sensor based on a microwave resonator coupled with a poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) conducting polymer (CP) film is proposed in this paper. ...The resonator is patterned on a printed circuit board and is excited by electromagnetic field coupling. To enhance the sensitivity of the sensor, the CP film is located in the area with the strongest electric field in the resonator. To investigate the performance, the proposed sensor is placed alongside a reference sensor in a humidity chamber, and humidity is injected at room temperature. The experimental results indicate that the electrical properties of the resonator with the CP film, such as the transmission coefficient (S
) and resonance frequency, change with the relative humidity (RH). Specifically, as the RH changes from 5% to 80%, S
and the resonance frequency change simultaneously. Moreover, the proposed sensor exhibits great repeatability in the middle of the sensing range, which is from 40% to 60% RH. Consequently, our resonator coupled with the CP film can be used as a real-time humidity-sensing device in the microwave range, where various radio-frequency devices are in use.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
We report the microstructure, electrical and electrochemical properties of hybrid nanofibers composed of polyacrylonitrile (PAN)/lignin-derived carbon nanofibers and LaMnO
3
-based inorganic ...nanofibers for advanced applications as free-standing and binder-free electrode materials of energy storage devices. For this purpose, hybrid nanofibers are fabricated via dual-electrospinning technique and following heat-treatment at different temperatures of 700–1000 °C for simultaneous carbonization and calcination. The SEM, EDS, and XPS analyses reveal that the carbon content in the hybrid nanofibers increases with increasing the heat-treatment temperature and that La and Mn elements are dispersed uniformly over the hybrid nanofibers. The hybrid nanofibers heat-treated at 900 and 1000 °C have a high electrical conductivity of ~ 0.22 S/cm and ~ 0.35 S/cm, respectively. Accordingly, a symmetric two-electrode supercapacitor based on hybrid nanofibers heat-treated at 1000 °C is characterized to have excellent electrochemical performance such as specific capacitance of ~ 95.2 F/g at 1 A/g, power density of 667 W/kg, energy density of 17.6 Wh/kg, and capacitance retention of ~ 97% after 2000 cycles. The results denote that PAN/lignin and LaMnO
3
-based hybrid nanofibers can be utilized as self-supporting high-performance electrode materials for advanced energy storage devices.
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DOBA, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, IZUM, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, SIK, UILJ, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
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•PI/PMMA-derived HCNFs are fabricated via coaxial electrospinning and heat treatment.•The core–shell structure of HCNFs is controlled by the flow rate during coaxial ...electrospinning.•High electrical conductivity of 1.17–1.35 S/cm is achieved for HCNFs.•A symmetric two HCNF-electrode setup has an excellent electrochemical performance.•HCNFs can be utilized as self-standing and binder-free electrode materials.
We investigated the microstructure and electrochemical properties of a series of hollow carbon nanofibers (HCNFs) fabricated via coaxial electrospinning of poly(amic acid) (PAA, shell part) as a precursor of polyimide (PI) and poly(methyl methacrylate) (PMMA, core part) solutions, followed by heat treatment for imidization at 300 °C and carbonization at 1000 °C. The core–shell structure of PI/PMMA-derived HCNFs could be controlled by the flow rate (0.0–0.8 mL/h) of the core solution during the coaxial electrospinning. HCNF-28 and HCNF-38, which were manufactured at the core flow rates of 0.2 and 0.3 mL/h, respectively, exhibited a stable hollow morphological feature, unlike other HCNFs. It was also revealed that an ordered graphitic structure with fewer defects was developed for HCNF-28 and HCNF-38. Consistently, the electrical conductivity was relatively high, with a value of 1.17 S/cm for HCNF-28 and 1.35 S/cm for HCNF-38. The overall performance of a symmetric supercapacitor system, made up of two free-standing HCNF-28 electrodes, was found to be high in aspects of specific capacitance (ranging from 220.6 to 108.6F/g), power density (from 250 to 5,000 W/kg), and energy density (from 18.0 to 7.0 Wh/kg) when evaluated at current densities from 1 to 10 A/g.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The simulation and design of electronic devices such as transistors is vital for the semiconductor industry. Conventionally, a device is intuitively designed and simulated using model equations, ...which is a time-consuming and expensive process. However, recent machine learning approaches provide an unprecedented opportunity to improve these tasks by training the underlying relationships between the device design and the specifications derived from the extensively accumulated simulation data. This study implements various machine learning approaches for the simulation acceleration and inverse-design problems of fin field-effect transistors. In comparison to traditional simulators, the proposed neural network model demonstrated almost equivalent results (R
= 0.99) and was more than 122,000 times faster in simulation. Moreover, the proposed inverse-design model successfully generated design parameters that satisfied the desired target specifications with high accuracies (R
= 0.96). Overall, the results demonstrated that the proposed machine learning models aided in achieving efficient solutions for the simulation and design problems pertaining to electronic devices. Thus, the proposed approach can be further extended to more complex devices and other vital processes in the semiconductor industry.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
To attain thermoplastic polymer composites with enhanced thermal and mechanical properties as well as long‐term durability, in this study, polyurethane‐coated carbon fiber (CF) and electron beam (EB) ...irradiation are adopted as an effective reinforcing filler and efficient crosslinking process, respectively. For this purpose, polyamide 6 (PA)‐based composites with different CF contents of 1–10 wt% were fabricated through melt‐compounding and compression molding, and then irradiated with various EB doses of 50–200 kGy. The SEM and FT‐IR data reveal that CFs are well dispersed in the PA matrix with excellent interfacial adhesion via specific intermolecular interactions, which are even enhanced for the composites with crosslinked PA matrices after the EB irradiation. As the result, the thermal stability (initial decomposition temperature and residue at 800°C) and dynamic mechanical properties of PA/CF composites increased noticeably with increasing the CF content and EB irradiation dose. The initial storage modulus of 1.90 GPa for neat PA at 30°C was improved significantly to 2.94 GPa by 10 wt% CF addition and to 4.67 GPa by 200 kGy EB irradiation. In particular, the long‐term mechanical properties of PA/CF composites, which were evaluated using a stepped isothermal method based on the time–temperature superposition principle, were found to be highly enhanced by the synergistic effect of CF filler reinforcement, EB‐induced PA matrix crosslinking, and improved interfacial adhesion.
Polyamide 6 (PA)‐based thermoplstic composites reinforced with 1‐10 wt% polyurethane‐coated short carbon fibers (CFs) are fabricated by melt‐mixing and electron beam (EB) irradiation. There exist specific interactions between CFs and PA in the composites. The thermal stability and mechanical property of the composites increase with the CF content and the EB irradiation dose. The long‐term mechanical durability of the composites is highly improved by the synergistic effect of CF filler and EB‐induced crosslinking.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Herein, the electromagnetic interference (EMI) shielding and electrothermal properties of MXene‐coated cellulose hybrid papers (MCPs) and fabrics (MCFs) with high flexibility and low density, which ...are manufactured by a dip‐dry coating approach, are reported. For this purpose, MCPs and MCFs are fabricated by dipping cellulose papers and fabrics repeatedly into an aqueous dispersion of MXene. The electron microscopic and X‐ray diffraction data reveal that MXene sheets are coated uniformly on the surfaces of cellulose fibrils and fibers and that their contents increase with the dip‐dry coating cycle. For MCP10 (5.68 wt% MXene) and MCF10 (11.77 wt% MXene), which are manufactured by ten‐time dip‐dry coating cycles, high electrical conductivity of 1.91 and 0.08 S cm−1 are attained, respectively. In addition, MCP10 and MCF10 possess excellent absolute EMI shielding effectiveness (SSEt) of 2198 and 1100 dB cm2 g−1 at 8 GHz, respectively, which is due to the multiple internal reflection and absorption of incident EM waves by conductive and interconnected MXene‐coated cellulose fibrils and fibers. It is also found that MCP1 (0.9 wt% MXene) and MCF1 (1.9 wt% MXene) at one‐time dip‐dry coating cycle show outstanding electrothermal performance in aspects of high saturated temperatures and energy conversion efficiency at low applied voltages.
The electromagnetic interference (EMI) shielding and electrothermal performance of MXene‐coated cellulose hybrid papers and fabrics, which are manufactured by an efficient dip‐dry coating approach, are investigated, considering the structural features and electrical properties. Hybrid papers and fabrics are characterized to have excellent absolute EMI‐shielding effectiveness of ≈2198 and ≈1100 dB cm2 g−1 at 8 GHz, respectively.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Objective Contrast agents used for radiological examinations are an important cause of acute kidney injury (AKI). We developed and validated a machine learning and clinical scoring prediction model ...to stratify the risk of contrast-induced nephropathy, considering the limitations of current classical and machine learning models. Methods This retrospective study included 38,481 percutaneous coronary intervention cases from 23,703 patients in a tertiary hospital. We divided the cases into development and internal test sets (8:2). Using the development set, we trained a gradient boosting machine prediction model (complex model). We then developed a simple model using seven variables based on variable importance. We validated the performance of the models using an internal test set and tested them externally in two other hospitals. Results The complex model had the best area under the receiver operating characteristic (AUROC) curve at 0.885 95% confidence interval (CI) 0.876-0.894 in the internal test set and 0.837 (95% CI 0.819-0.854) and 0.850 (95% CI 0.781-0.918) in two different external validation sets. The simple model showed an AUROC of 0.795 (95% CI 0.781-0.808) in the internal test set and 0.766 (95% CI 0.744-0.789) and 0.782 (95% CI 0.687-0.877) in the two different external validation sets. This was higher than the value in the well-known scoring system (Mehran criteria, AUROC=0.67). The seven precatheterization variables selected for the simple model were age, known chronic kidney disease, hematocrit, troponin I, blood urea nitrogen, base excess, and N-terminal pro-brain natriuretic peptide. The simple model is available at http://52.78.230.235:8081/Conclusions We developed an AKI prediction machine learning model with reliable performance. This can aid in bedside clinical decision making.
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