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Digital twin represents the core technology to realize the dynamic monitoring of complex industrial systems. However, the human body, as the most complex system in the physical world, digital twin is rarely applied in it. In this study, we successfully demonstrated a digital twin in the human biomedical application by proposing a dynamic monitoring system of the upper limb force. In this system, the real upper limb drives the motion of the virtual one in real-time and dynamically updates the force. Meanwhile, the virtual upper limb feeds back the monitoring-results of the force to the controller of the real upper limb via immersive virtual reality interaction. Experimental results of the typical motions of the upper limb revealed that the proposed system functioned interactively in real-time in a non-invasive manner, while ensuring the accurate solving of the muscle force. In conclusion, our digital twin-driven system is of great importance for rehabilitation medicine, biomechanical scientific research and physical training, promoting the application of the digital twin in the human biomedical field. [ABSTRACT FROM AUTHOR]

Constructing heterostructures from already synthesized two-dimensional materials is of significant importance. We performed a first-principles study to investigate the electronic properties and interfacial characteristics of Janus MoSH/WSi2N4 van der Waals heterostructure (vdWH) contacts. We demonstrate that the p-type Schottky formed by MoSH/WSi2N4 and MoHS/WSi2N4 has extremely low Schottky barrier heights (SBHs). Due to its excellent charge injection efficiency, Janus MoSH may be regarded as an effective metal contact for WSi2N4 semiconductors. Furthermore, the interfacial characteristics and electronic structure of Janus MoSH/WSi2N4 vdWHs can not only reduce/eliminate SBH, but also forms the transition from p-ShC to n-ShC type and from Schottky contact (ShC) to Ohmic contact (OhC) through the layer spacing and electric field. Our results can offer a fresh method for optoelectronic applications based on metal/semiconductor Janus MoSH/WSi2N4 vdW heterostructures, which have strong potential in optoelectronic applications. [ABSTRACT FROM AUTHOR]

The disposal and management of waste lithium-ion batteries (LIBs) and low-density polyethylene (LDPE) plastics pose significant environmental challenges. Here we show a synergistic pyrolysis approach that employs spent lithium transition metal oxides and waste LDPE plastics in one sealed reactor to achieve the separation of Li and transition metal. Additionally, we demonstrate the preparation of nanoscale NiCo alloy@carbon nanotubes (CNTs) through co-pyrolysis of LiNi0.6Co0.2Mn0.2O2 and LDPE. The NiCo alloy@CNTs exhibits excellent catalytic activity (Eonset = ~0.85 V) and the selectivity (~90%) for H2O2 production through the electrochemical reduction of oxygen. This can be attributed to the NiCo nanoalloy core and the presence of CNTs with abundant oxygen-containing functional groups (e.g., –COOH and C–O–C), as confirmed by density function theory calculations. Overall, this work presents a straightforward and green approach for valorizing and upcycling various waste LIBs and LDPE plastics. Waste lithium-ion batteries and low-density polyethylene plastics present environmental issues. Herein, the authors demonstrate a synergistic pyrolysis approach for efficient and selective lithium extraction and upgrading of transition metal-carbon composites. [ABSTRACT FROM AUTHOR]

ADSCs are a great cell source for tissue engineering and regenerative medicine. However, the development of methods to appropriately manipulate these cells in vitro remains a challenge. Here the proliferation and differentiation of ADSCs on microfabricated surfaces with varying geometries were investigated. To create the patterned substrates, a maskless biofabrication method was developed based on dynamic optical projection stereolithography. Proliferation and early differentiation of ADSCs were compared across three distinct multicellular patterns, namely stripes (ST), symmetric fork (SF), and asymmetric fork (AF). The ST pattern was designed for uniaxial cell alignment while the SF and AF pattern were designed with altered cell directionality to different extents. The SF and AF patterns generated similar levels of regional peak stress, which were both significantly higher than those within the ST pattern. No significant difference in ADSC proliferation was observed among the three patterns. In comparison to the ST pattern, higher peak stress levels of the SF and AF patterns were associated with up-regulation of the chondrogenic and osteogenic markers SOX9 and RUNX2. Interestingly, uniaxial cell alignment in the ST pattern seemed to increase the expression of SM22α and smooth muscle α-actin, suggesting an early smooth muscle lineage progression. These results indicate that geometric cues that promote uniaxial alignment might be more potent for myogenesis than those with increased peak stress. Overall, the use of these patterned geometric cues for modulating cell alignment and form-induced stress can serve as a powerful and versatile technique towards controlling differentiation in ADSCs.

Using a combination of dynamical and statistical downscaling techniques, we projected mid-21stcentury warming in the Los Angeles region at 2-km (1.2-mile) resolution. To account for uncertainty associated with the trajectory of future greenhouse gas emissions and other factors affecting the planet's energy balance, we examined projections for both "business-as-usual" (RCP8.5) and "mitigation" (RCP2.6) emissions scenarios of the Fifth Coupled Model Intercomparison Project. To account for the considerable uncertainty associated with choice of global climate model, we downscaled results for all available global models. For the business-as-usual scenario, we find that by the mid-21stcentury, the most likely warming is roughly 4.6°F averaged over the region's land areas, with a 95% confidence that the warming lies between 1.7 and 7.5°F. The high resolution of the projections reveals a pronounced spatial pattern in the warming: High elevations and inland areas separated from the coast by at least one mountain complex warm 20 to 50% more than the areas near the coast or within the Los Angeles basin. This warming pattern is especially apparent in summertime. The summertime warming contrast between the inland and coastal zones has a large effect on the most likely expected number of extremely hot days per year. Coastal locations and areas within the Los Angeles basin see roughly two to three times the number of extremely hot days, while high elevations and inland areas typically experience approximately three to five times the number of extremely hot days. Under the mitigation emissions scenario, the most likely warming and increase in heat extremes are somewhat smaller. However, the majority of the warming seen in the business-as-usual scenario still occurs at all locations in the most likely case under the mitigation scenario, and heat extremes still increase significantly. Therefore adaptation to a changing climate over the next few decades is likely to be inevitable in the Los Angeles region.

We show that intermodel variations in the anthropogenically-forced evolution of September sea ice extent (SSIE) in the Arctic stem mainly from two factors: the baseline climatological sea ice thickness (SIT) distribution, and the local climate feedback parameter. The roles of these two factors evolve over the course of the twenty-first century. The SIT distribution is the most important factor in current trends and those of coming decades, accounting for roughly half the intermodel variations in SSIE trends. Then, its role progressively decreases, so that around the middle of the twenty-first century the local climate feedback parameter becomes the dominant factor. Through this analysis, we identify the investments in improved simulation of Arctic climate necessary to reduce uncertainties both in projections of sea ice loss over the coming decades and in the ultimate fate of the ice pack.