Search

Naturally-derived proteins or peptides are promising biopolymers for tissue engineering applications owing to their health-promoting activity. Herein, we extracted proteins (~90%) from two-spotted cricket (Gryllus bimaculatus) and evaluated their osteoinductive potential in human bone marrow-derived mesenchymal stem cells (hBMSCs) under in vitro conditions. The extracted protein isolate was analyzed for the amino acid composition and the mass distribution of the constituent peptide fraction. Fourier transform infrared (FTIR) spectroscopy was used to determine the presence of biologically significant functional groups. The cricket protein isolate (CPI) exhibited characteristic protein peaks in the FTIR spectrum. Notably, an enhanced cell viability was observed in the presence of the extracted proteins, showing their biocompatibility. The CPI also exhibited antioxidant properties in a concentration-dependent manner. More significant mineralization was observed in the CPI-treated cells than in the control, suggesting their osteoinductive potential. The upregulation of the osteogenic marker genes (Runx2, ALP, OCN, and BSP) in CPI treated media compared with the control supports their osteoinductive nature. Therefore, cricket-derived protein isolates could be used as functional protein isolate for tissue engineering applications, especially for bone regeneration.

Edible insects have received global attention as an alternative protein-rich food. However, their structural characteristics make them difficult to digest. To overcome this obstacle, we assessed the techno-functional properties of three protein concentrates from the cricket Gryllus bimaculatus. Freeze-dried G. bimaculatus powder was defatted using ethanol, hexene, or acetone as solvents, and the techno-functional properties (protein solubility, water and oil holding capacity, foaming properties, emulsion capacity, and gel formation) of the protein concentrates were determined. Freeze-dried G. bimaculatus powder comprised approximately 17.3% crude fat and 51.3% crude protein based on dry weight. Ethanol was the most effective solvent for reducing the fat content (from 17.30% to 0.73%) and increasing the protein content (from 51.3% to 62.5%) of the concentrate. Techno-functionality properties drastically differed according to the defatting solvent used and foaming properties were most affected. Thus, the techno-functional and whole properties must be considered for proper application of edible insects to achieve global food sustainability.

The osteogenic differentiation of stem cells is profoundly affected by their microenvironmental conditions. The differentiation behavior of stem cells can be tuned by changing the niche environments. The proteins or peptides that are derived by living organisms facilitate the osteogenic differentiation of stem cells. Here, we have evaluated the osteoinductive and antioxidative potential of the Protaetia brevitarsis seulensis insect-derived protein for human bone marrow-derived mesenchymal stem cells (hBMSCs). The amino acid contents in the isolated protein were determined by an amino acid analyzer. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to analyze the extract’s functional groups and surface morphology. The extracted protein exhibited 51.08% β-sheet conformation. No adverse effects were observed in extract-treated cells, indicating their biocompatibility. The protein isolate showed an excellent antioxidative property. Besides this, an enhancement in the hBMSCs’ mineralization has been observed in the presence of treated protein isolates. Notably, osteogenic marker genes and proteins were effectively expressed in the treated cells. These results indicated that the P. brevitarsis-derived protein isolate can be used as a potential antioxidative biomaterial for bone tissue engineering applications.

Aeroelastic instability problems have become an increasingly important issue due to the increased use of larger horizontal axis wind turbines. To maintain these large structures in a stable manner, the blade design process should include studies on the dynamic stability of the wind turbine blade. Therefore, fluid-structure interaction analyses of the large-scaled wind turbine blade were performed with a focus on dynamic stability in this study. A finite element method based on the large deflection beam theory is used for structural analysis considering the geometric nonlinearities. For the stability analysis, a proposed aerodynamic approach based on Greenberg’s extension of Theodorsen’s strip theory and blade element momentum method were employed in conjunction with a structural model. The present methods proved to be valid for estimations of the aerodynamic responses and blade behavior compared with numerical results obtained in the previous studies. Additionally, torsional stiffness effects on the dynamic stability of the wind turbine blade were investigated. It is demonstrated that the damping is considerably influenced by variations of the torsional stiffness. Also, in normal operating conditions, the destabilizing phenomena were observed to occur with low torsional stiffness.

The warm-season hydroclimatology stemming primarily from the monsoon and typhoons in East Asia is an important determinant of sustainable water supplies for coupled human and natural systems. Therefore, in this study, we develop an empirical approach to the separation of summer rainfall into typhoon and monsoon types. In addition, exploratory analysis is conducted for regional patterns of summer precipitation across the Korean Peninsula (KP) to determine changes in the various types of temperature gradient. The results show that atmospheric thermal transitions lead significant and consistent changes in rainfall during the boreal summer season (June-September) in South Korea. For positive land-ocean contrast years, statistically significant positive anomalies of summer precipitation were exhibited in the interior and eastern river basins. In contrast, for negative years, suppression of seasonal precipitation patterns was detected. Moreover, during years of positive meridional temperature gradient, summers tended to be wetter relative to the long-term average. Although the time window of typhoon impacts may vary for different episodic typhoon events, the obtained positive anomalies of seasonal precipitation were more significant after removing the effects of tropical cyclones over the KP. [ABSTRACT FROM AUTHOR]

Wake effects of a horizontal-axis wind-turbine blade on aeroelastic characteristics were investigated under normal operational conditions. A structural analysis was performed employing a nonlinear beam model based on the large deflection beam theory. For inflow analysis on rotor blades, a free-vortex wake method was employed. An advantage of the present approach is its ability to calculate directly the induced velocities from the wake. Also, for the predictions of aerodynamic loads, a fully turbulent flow solution is invoked in FLUENT, where the k-to SST turbulent model of two-dimensional airfoils is adopted for transient analysis. To verify and validate the aerodynamic model for wind turbines, the wake geometry and the aerodynamic coefficients from the present simulation are compared with measurements and numerical results of previous studies. Finally, an analysis of the tightly coupled fluid-structure interaction phenomena of a wind-turbine blade has been carried out to investigate aeroelastic characteristics, such as steady-state blade deflections and dynamic stability. The present results are compared with the numerical results obtained using a uniform inflow model, which clearly confirms the importance of wake effects on the blade aeroelastic characteristics. [ABSTRACT FROM AUTHOR]

Modern horizontal axis wind turbine blades are long, slender, and flexible structures that can undergo considerable deformation, leading to blade failures (e.g., blade-tower collision). For this reason, it is important to estimate blade behaviors accurately when designing large-scale wind turbines. In this study, a numerical analysis considering blade torsional degree of freedom, geometric nonlinearity, and gravity was utilized to examine the effects of these factors on the aeroelastic blade behavior of a large-scale horizontal axis wind turbine. The results predicted that flapwise deflection is mainly affected by the torsional degree of freedom, which causes the blade bending deflections to couple to torsional deformation, thereby varying the aerodynamic loads through changes in the effective angle of attack. Edgewise deflection and torsional deformation are mostly influenced by the periodic gravitational force on the wind turbine blade. [ABSTRACT FROM AUTHOR]

The article discusses a study that investigated the flap-lag-torsion stability of helicopters' hingeless and bearingless rotors in forward flight using a finite element formulation based on a Hamilton's principle. A free-wake method for an aeroelastic analysis and a linear inflow model were introduced for predicting the wake more accurately. The researchers used three different aerodynamic models in addition to a nonlinear beam model based on a large deflection beam theory.

The wake effects on aeroelastic deflections and aerodynamics for the isotropic and composite rotor blades have been investigated. To take into account the large deflections and rotations of rotor blades, a large-deflection beam model was used. A free-wake model based on vortex-lattice method was used to obtain the aerodynamic forces while considering wake effects. Newton-Raphson iteration method was applied to the aeroelastic analysis to obtain the numerical solutions. The flap, lag, and torsion deflections considering wake effects by using the free-wake model were investigated and compared with the results using two-dimensional quasi-steady model. Finally, aerodynamic changes after aeroelastic deflections were investigated. [ABSTRACT FROM AUTHOR]

OBJECTIVE: • To investigate the impact of increased body mass index (BMI) on pathological features after radical prostatectomy (RP) in Korean patients. PATIENTS AND METHODS: • We reviewed the records of 1000 Korean patients who underwent RP for prostate cancer and assessed the differences in pathological outcomes and biochemical recurrence-free survival after RP according to BMI of subjects via univariate and multivariate analyses. • A multivariate logistics regression model, the performance of which was analysed from a receiver operator characteristics curve, was applied to assess the predictive capacity of variables shown to be significant predictors of adverse pathological outcome. RESULTS: #x2022; Among our subjects, only 17 (1.7%) men had BMI ≥ 30 kg/m 2. After adjusting for various clinical variables, BMI (highest quartile vs others) was shown to be significantly associated with extracapsular extension of tumour ( P = 0.014) and positive surgical margin ( P = 0.019), but not with high pathological Gleason score ( P = 0.912) and seminal vesicle invasion ( P = 0.191). • Meanwhile, the addition of BMI to a multivariate model devised for preoperatively predicting extracapsular extension of tumour did not significantly increase predictive accuracy of the model ( P = 0.319). On multivariate analysis, BMI was not shown to be a significant predictor of biochemical recurrence-free survival ( P = 0.201). CONCLUSION: • Although higher BMI was significantly associated with extracapsular extension of tumour, BMI did not significantly enhance the ability to preoperatively predict extra capsular extension of tumour and was not significantly associated with PSA outcome or with other objective pathological outcomes in Korean men undergoing RP, who are generally leaner than their western counterparts. [ABSTRACT FROM AUTHOR]