Knee osteoarthritis (OA) is a degenerative disease that impairs joint function. Adipose-derived stem cells (ADSCs) are promising for therapy due to their regenerative potential, particularly when cultured as spheroids to enhance paracrine activity. However, conventional plate-based spheroid culture faces challenges such as scalability limits, retrieval difficulties, excessive enlargement, and necrotic core formation, all of which may compromise therapeutic efficacy. An optimized, scalable method is therefore required for clinical application. This study aimed to establish a spheroid culture protocol using the SphereRing (R) device with methylcellulose (MC) to regulate spheroid size, improve viability, and enhance secretion of therapeutic factors including exosomes and interleukin-10 (IL-10). ADSCs were cultured in SphereRing (R) with 0.5-1 % MC for 3 days, and spheroid size, morphology, viability, and secretory profiles were assessed. Spheroids cultured with 0.75 % MC exhibited the most uniform size distribution, higher circularity, reduced necrotic core formation, and significantly greater viability compared to untreated controls. Moreover, IL-10 and exosome secretion were markedly increased in the 0.75 % MC group. Patient-derived ADSCs showed comparable improvements. MC-treated spheroids also maintained superior viability after exposure to synovial fluid, simulating intra-articular conditions. These findings suggest that incorporating MC into the SphereRing (R) system enables scalable and uniform spheroid production, establishing a clinically relevant platform for ADSC-based therapy in knee OA with potential to improve treatment consistency and outcomes.
Direct numerical simulations of the concentric annular turbulent pipe flow are performed to investigate the skin-friction drag reduction effect by the wall oscillation control technique. The oscillation on the inner and outer walls is synchronized, and the control effect is investigated for different radius ratios. While drag reduction by wall oscillation has been extensively studied in canonical wall-bounded flows such as plane channels and circular pipes, its effects in geometrically non-uniform configurations, such as the annular pipe, remain less understood. Curvature and frictional asymmetry give rise to characteristic flow responses. The simulations demonstrate that the friction drag decreases owing to the wall oscillation. The maximum drag reduction rate is R_D ≈ 0.5 at the optimal period of T^+ ≈ 150 . An identity equation for the skin-friction coefficient of the annular pipe flow is derived, and the contribution from turbulence is quantitatively discussed. Scaling methods for the drag reduction rate are applied: 1) increment of the mean velocity and 2) based on the Stokes problem. Both scaling methods appropriately describe the drag-reduction behavior in the drag-reduction regime at T^+ ⪅ 150 .
We theoretically investigate the transient spectral function during the photoinduced melting of charge order in a correlated electron system, to unravel the dynamical processes triggered by different initial excitations. We employ a one-dimensional interacting spinless fermion model introducing a pulsed laser light, and perform a comparative study by the Hartree-Fock approximation and by the exact diagonalization method to numerically solve the time-dependent Schr & ouml;dinger equation. We find characteristic behavior in the transient spectral function, whose features strongly depend on the pump light frequency omega(p). When omega(p) is resonant with the collective phase mode of frequency Omega(c)similar or equal to Delta(CO)/2, where Delta(CO) is the charge gap, the transient spectral function exhibits a photoinduced in-gap weight that triggers large responses. With increasing laser intensity, the development of in-gap weight directly turns into the collapse of the gap. This charge-order destabilization process is in sharp contrast to the case of omega(p) > Delta(CO), where the photoirradiation induces interband electron-hole excitations giving rise to a shrinkage of the gap. The impact of quantum fluctuations and spatial inhomogeneity on the photoinduced dynamics is also discussed.
Thermal problems of transistors, particularly self-heating (SH) effects, pose significant challenges for the accurate design of cryogenic control circuits for quantum computers. This study evaluated the SH characteristics of 200-nm silicon-on-insulator (SOI) metal-oxide semiconductor field-effect transistors (MOSFETs) and thermal conduction to adjacent devices at cryogenic temperatures using the four-terminal gate resistance method. A rapid rise in channel temperature of the SOI MOSFET due to SH was confirmed at 3 K. Additionally, it was found that thermal conduction from the heater exhibits greater localization at cryogenic temperatures compared to room temperature. Furthermore, the experimental findings were validated through two-dimensional thermal simulations.
n low- and middle-income countries, information and communication technology (ICT) professionals with soft skills have been recognized as potential leaders for economic growth, and professional experience abroad is an effective way to obtain soft skills. However, only a limited number of people have the opportunity to go abroad. In our research, we sought to understand whether soft skills such as those learned from international professional experience can be obtained through a domestic training course provided to Bangladeshi ICT professionals who aspired to work abroad. Through a randomized controlled trial, we found a mix of immediate effects of the training and latent effects that could be observed only after participants started working, especially when they worked abroad. Moreover, we find that training, while having some impact on conscientiousness, seems to be insufficient on its own—actual experience with the new environment seems to play a critical role. This study found evidence that the effectiveness of training strategies depends on the design of the training content, as well as when and where the effects of the intervention are expected to be observed.
