Distribution characteristics of soil microplastics and their impact on soil physicochemical properties in agricultural areas of the North China plain.

Microplastic (MPs) pollution has become a global issue, with particular concern regarding MPs in soil. To determine the characteristics of MPs in agricultural production areas and their impact on soil physicochemical properties, soil samples were collected from different land use types in the North China Plain. Layered sampling was conducted and the soil physicochemical properties were determined. A novel image recognition method based on fluorescence staining was proposed for the batch analysis of MPs in the study area. Together with the results of the soil physicochemical properties, the impact of MPs on soil physicochemical properties was analyzed and evaluated. The results showed that the soil MPs abundance in this agricultural area was moderate to low compared to other agricultural areas, with a larger proportion of particle-type and fragment-type MPs smaller than 10 µm. The soil MPs were predominantly composed of polyvinyl chloride (PVC) and polypropylene (PP). MPs abundance was higher in farmland and forest land than in vegetable fields. The impact of MPs on soil physicochemical properties was mainly manifested in the changes in soil structure due to the different MPs characteristics. Apart from abundance, the type of MPs was found to be the main factor affecting soil bulk density, with particle size and shape influencing the soil aggregate structure. MPs may effect the pH values of sandy and loamy soils, primarily by altering the soil porosity and water holding capacity, but also by increasing the area and duration of contact between the soil medium and external water sources. This study revealed the MPs characteristics in agricultural areas as well as the pathways by which they can impact soil physicochemical properties.

Preclinical Safety Assessment of Deferoxamine-preconditioned Canine Adipose Tissue-derived Mesenchymal Stem Cells.

BACKGROUND/AIM: In the pursuit of translating stem cell therapy technology into clinical practice, ensuring the safety and efficacy of treatments is paramount. Despite advancements, the effectiveness of stem cell applications often falls short of clinical requirements. This study aimed to address the challenge of limited efficacy by investigating the safety and effectiveness of canine adipose tissue-derived mesenchymal stem cells (cATMSCs) preconditioned with deferoxamine (DFO). MATERIALS AND METHODS: Different concentrations of DFO were used to evaluate its impact on cATMSC activity. The therapeutic potential of these preconditioned cells was validated using a mouse model of systemic inflammation. Comprehensive evaluations, including clinical hematological and radiological assessments before and after intravenous injection of preconditioned cells were conducted. RESULTS: The study showed a notable reduction in inflammatory markers and an overall decrease in the inflammatory response in the mouse model. The data collected from the clinical hematological and radiological assessments provided essential insights. CONCLUSION: This study lays the groundwork for the future clinical deployment of DFO-preconditioned cATMSCs, demonstrating their potential to improve the efficacy and safety of stem cell therapies.

Photonics for Neuromorphic Computing: Fundamentals, Devices, and Opportunities.

In the dynamic landscape of Artificial Intelligence (AI), two notable phenomena are becoming predominant: the exponential growth of large AI model sizes and the explosion of massive amount of data. Meanwhile, scientific research such as quantum computing and protein synthesis increasingly demand higher computing capacities. As the Moore's Law approaches its terminus, there is an urgent need for alternative computing paradigms that satisfy this growing computing demand and break through the barrier of the von Neumann model. Neuromorphic computing, inspired by the mechanism and functionality of human brains, uses physical artificial neurons to do computations and is drawing widespread attention. This review studies the expansion of optoelectronic devices on photonic integration platforms that has led to significant growth in photonic computing, where photonic integrated circuits (PICs) have enabled ultrafast artificial neural networks (ANN) with sub-nanosecond latencies, low heat dissipation, and high parallelism. In particular, various technologies and devices employed in neuromorphic photonic AI accelerators, spanning from traditional optics to PCSEL lasers are examined. Lastly, it is recognized that existing neuromorphic technologies encounter obstacles in meeting the peta-level computing speed and energy efficiency threshold, and potential approaches in new devices, fabrication, materials, and integration to drive innovation are also explored. As the current challenges and barriers in cost, scalability, footprint, and computing capacity are resolved one-by-one, photonic neuromorphic systems are bound to co-exist with, if not replace, conventional electronic computers and transform the landscape of AI and scientific computing in the foreseeable future.

Settling velocity of irregularly shaped microplastics under steady and dynamic flow conditions.

The behavior of microplastics (MPs) in aquatic environments can vary significantly according to their composition, shape, and physical and chemical properties. To predict the settling trajectory of MPs in aquatic environments, this study investigates the settlement law of MPs under static and dynamic conditions. Four types of materials were analyzed, namely polystyrene, polyamide, polyethylene terephthalate, and polyvinyl chloride. Approximately 1270 MP particles with irregular shapes (near-sphere, polygonal ellipsoid, and fragment) were selected for the settling experiments. The experimental results show that the main factors affecting the settling velocity of MPs were shape irregularity, density, and particle size. The settling velocity of irregular MPs was significantly lower than that of perfectly spherical MPs. We proposed a model that predicts the correlation between the settling velocity of MPs and their shape, density, particle size, and water density.

Nitrogen-Doped Microporous Carbons Derived from Pyridine Ligand-Based Metal-Organic Complexes as High-Performance SO2 Adsorption Sorbents.

Heteroatom-doped porous carbons are emerging as platforms for gas adsorption. Herein, N-doped microporous carbon (NPC) materials have been synthesized by carbonization of two pyridine ligand-based metal-organic complexes (MOCs) at high temperatures (800, 900, 1000, and 1100 °C). For NPCs (termed NPC-1- T and NPC-2- T, where T represents the carbonization temperature), the micropore is dominant, pyridinic-N and other N atoms of MOC precursors are mostly retained, and the N content reaches as high as 16.61%. They all show high Brunauer-Emmett-Teller surface area and pore volume, in particular, NPC-1-900 exhibits the highest surface areas and pore volumes, up to 1656.2 m2 g-1 and 1.29 cm3 g-1, respectively, a high content of pyridinic-N (7.3%), and a considerable amount of SO2 capture (118.1 mg g-1). Theoretical calculation (int = ultrafine m062x) indicates that pyridinic-N acts as the leading active sites contributing to high SO2 adsorption and that the higher content of pyridinic-N doping into the graphite carbon layer structure could change the electrostatic surface potential, as well as the local electronic density, which enhanced SO2 absorption on carbon edge positions. The results show great potential for the preparation of microporous carbon materials from pyridine ligand-based MOCs for effective SO2 adsorption.

Novel Hydrogen-Bonding Cross-Linking Aggregation-Induced Emission: Water as a Fluorescent "Ribbon" Detected in a Wide Range.

The development of efficient sensors for detection of the water content in a wide detection range is highly desirable for balance in many industrial processes and products. Presented herein are six novel different substituted Schiff base Zn(II) complexes, which exhibit the remarkable capability to detect traces of water in a wide linear range (most can reach 0-94%, v/v), low detection limit of 0.2% (v/v), and rapid response time of 8 s in various organic solvents by virtue of an unusual water-activated hydrogen-bonding cross-linking AIE (WHCAIE) mechanism. As a proof-of-concept, the WHCAIE mechanism is explained well by single X-ray diffraction, absorption spectra, fluorescence spectra, dynamic light scattering, 1H NMR spectra, and theoretical calculations. In addition, the molecules demonstrated their application for the detection of humidity (42-80%). These Schiff base Zn(II) complexes become one of the most powerful water sensors known due to their extraordinary sensitivity, fast response, and wide detection range for water.

Carboxyl-functionalized dual pH/temperature-responsive poly(N-vinylcaprolactam) microgels based on isogenous comonomers for smart window applications.

Stimuli-responsive poly(N-vinylcaprolactam) (PVCL)-based microgels, which could response to small external environmental changes, have attracted great interests in the fields of biomedicine and nanotechnology. However, the preparation of such microgels meets severe challenge due to their low incorporation efficiency and thermoresponsivity passivation. To address these issues, we select 3-(tert-butoxycarbonyl)-N-vinylcaprolactam (TBVCL), a carboxyl-functionalized VCL derivative, as a comonomer to develop pH/temperature dual-responsive microgels. TBVCL, with a structure similar to VCL, enhances incorporation efficiency and colloidal stability, while reducing thermoresponsivity passivation. The volume phase transition temperature (VPTT) of the microgels can be adjusted over a broad range (19.0-49.5 °C). Notably, the radial swelling ratios of the microgels can be modulated by pH, achieving a maximum swelling ratio of 3. The distinct changes in dissolution-precipitation behavior under different temperatures or pH conditions make these microgels suitable for applications such as smart windows and sensors. Furthermore, this novel approach for fabricating microgels with pH-tunable phase-transition temperatures demonstrates significant potential for the controlled release of nanoparticles (e.g., drugs, catalysts, and quantum dots) and the development of smart nanocrystal-polymer composite sensors.