Implanted scaffolds with inductive niches can facilitate the recruitment and differentiation of host cells, thereby enhancing endogenous tissue regeneration. Extracellular matrix (ECM) scaffolds derived from cultured cells or natural tissues exhibit superior biocompatibility and trigger favourable immune responses. However, the lack of hierarchical porous structure fails to provide cells with guidance cues for directional migration and spatial organization, and consequently limit the morpho-functional integration for oriented tissues. Here, we engineer ECM scaffolds with parallel microchannels (ECM-C) by subcutaneous implantation of sacrificial templates, followed by template removal and decellularization. The advantages of such ECM-C scaffolds are evidenced by close regulation of in vitro cell activities, and enhanced cell infiltration and vascularization upon in vivo implantation. We demonstrate the versatility and flexibility of these scaffolds by regenerating vascularized and innervated neo-muscle, vascularized neo-nerve and pulsatile neo-artery with functional integration. This strategy has potential to yield inducible biomaterials with applications across tissue engineering and regenerative medicine.
A deuterium-deuterium (DD) neutron generator–based neutron activation analysis (NAA) system has been developed to quantify metals, including manganese (Mn), in bone in vivo. A DD neutron generator with a flux of up to 3*109 neutrons/second was set up in our lab for this purpose. Optimized settings, including moderator, reflector, and shielding material and thickness, were selected based on Monte Carlo (MC) simulations conducted in our previous work. Hand phantoms doped with different Mn concentrations were irradiated using the optimized DD neutron generator irradiation system. The Mn characteristic γ-rays were collected by an HPGe detector system with 100% relative efficiency. The calibration line of the Mn/calcium (Ca) count ratio versus bone Mn concentration was obtained (R2 = 0.99) using the hand phantoms. The detection limit (DL) was calculated to be about 1.05 μg/g dry bone (ppm) with an equivalent dose of 85.4 mSv to the hand. The DL can be reduced to 0.74 ppm by using two 100% HPGe detectors. The whole body effective dose delivered to the irradiated subject was calculated to be about 17 μSv. Given the average normal bone Mn concentration of 1 ppm in the general population, this system is promising for in vivo bone Mn quantification in humans.
This study was conducted to investigate the methodology and feasibility of developing a transportable neutron activation analysis (NAA) system to quantify manganese (Mn) in bone using a portable deuterium–deuterium (DD) neutron generator as the neutron source. Since a DD neutron generator was not available in our laboratory, a deuterium–tritium (DT) neutron generator was used to obtain experimental data and validate the results from Monte Carlo (MC) simulations. After validation, MC simulations using a DD generator as the neutron source were then conducted. Different types of moderators and reflectors were simulated, and the optimal thicknesses for the moderator and reflector were determined. To estimate the detection limit (DL) of the system, and to observe the interference of the magnesium (Mg) γ line at 844 keV to the Mn γ line at 847 keV, three hand phantoms with Mn concentrations of 30 parts per million (ppm), 150 ppm, and 500 ppm were made and irradiated by the DT generator system. The Mn signals in these phantoms were then measured using a 50% high-efficiency high-purity germanium (HPGe) detector. The DL was calculated to be about 4.4 ppm for the chosen irradiation, decay, and measurement time. This was calculated to be equivalent to a DL of about 3.3 ppm for the DD generator system. To achieve this DL with one 50% high-efficiency HPGe detector, the dose to the hand was simulated to be about 37 mSv, with the total body equivalent dose being about 23μSv. In conclusion, it is feasible to develop a transportable NAA system to quantify Mn in bone in vivo with an acceptable radiation exposure to the subject.
The profit of greenhouse production is influenced by management activities (e.g., environmental control and plantation scheduling) as well as social conditions (e.g., price fluctuation). In China, the prevailing horticultural facility is the traditional solar greenhouse. The key existing problem is the lack of knowledge of growers, which in turn leads to inefficient management, low production, or unsalable products. To secure effective greenhouse management, the production planning system must account for the crop growing environment, grower's activities, and the market. This paper presents an agricultural cyber-physical-social system (CPSS) serving agricultural production management, with a case study on the solar greenhouse. The system inputs are derived from social and physical sensors, with the former collecting the price of agricultural products in a wholesale market, and the latter collecting the necessary environmental data in the solar greenhouse. Decision support for the cropping plan is provided by the artificial system, computational experiment, and parallel execution-based method, with description intelligence for estimating the crop development and harvest time, prediction intelligence for optimizing the planting time and area according to the expected targets (stable production or maximum gross profit), and prescription intelligence for online system training. The presented system fits the current technical and economic situation of horticulture in China. The application of agricultural CPSS could decrease waste in labor or fertilizer and support sustainable agricultural production.
Photocatalytic decomposition of water is the most attractive method for the sustainable production of hydrogen, but the development of a highly active and low-cost catalyst remains a major challenge. Here, we report the preparation of LaCoO 3 /g-C 3 N 4 nanosheets and the utilization of LaCoO 3 instead of noble metals to improve the photocatalytic activity for the production of hydrogen. First, LaCoO 3 was successfully prepared by the sol−gel method, and then a series of highly efficient Z-scheme LaCoO 3 /g-C 3 N 4 heterojunction photocatalysts were synthesized by the solvothermal method. Various characterization techniques (X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), ultraviolet−visible (UV−vis) diffuse reflectance spectroscopy (DRS), photoluminescence (PL), transient photocurrent response test, electron paramagnetic resonance (EPR)) confirm that the heterostructure and interfacial interaction had been formed between LaCoO 3 nanoparticles and g-C 3 N 4 nanosheets. In the photocatalytic water splitting test, LaCoO 3 /g-C 3 N 4 -20 wt % exhibited the highest photocatalytic activity of 1046.15 μmol h −1 g −1 , which is 3.5 and 1.4 times higher than those of LaCoO 3 and g-C 3 N 4 , respectively. This work leads to an inexpensive and efficient LaCoO 3 /g-C 3 N 4 photocatalysis system for water splitting or other photocatalytic applications.
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