Biomimetic Conductive Hydrogel Scaffolds with Anisotropy and Electrical Stimulation for In Vivo Skeletal Muscle Reconstruction.

The nature of the hydrogel scaffold mimicking extracellular matrix plays a crucial role in tissue engineering like skeletal muscle repair. Herein, an anisotropic and conductive hydrogel scaffold is fabricated using gelatin methacryloyl (GelMA) as the matrix hydrogel and silver nanowire (AgNW) as the conductive dopant, through a directional freezing technique for muscle defect repair. The scaffold has an anisotropic structure composed of a directional longitudinal section and a honeycomb cross-section, with high mechanical strength of 10.5 kPa and excellent conductivity of 0.26 S m-1 . These properties are similar to native muscle extracellular matrix (ECM) and allow for cell orientation under the guidance of contact cues and electrical stimulation synergistically. In vitro experiments show that the scaffold's oriented structure combined with electrical stimulation results in enhanced myotube formation, with a length of up to 863 µm and an orientation rate of 81%. Furthermore, the electrically stimulated scaffold displays a promoted muscle reconstruction ability when transplanted into rats with muscle defects, achieving a muscle mass and strength restoration ratio of 95% and 99%, respectively, compared to normal levels. These findings suggest that the scaffold has great potential in muscle repair applications.

Multifunctional rural transition along China's Yangtze River Transect: Spatial differentiation and economic relevance.

To understand rural sustainability, it is necessary to scrutinize the relationship between rural transition and economic growth. The article uses rural multifunctionality as an analytical lens through which to view the processes of the development of rural occupancy. There is a pressing need to ascertain how to quantify rural multifunctionality and reveal its spatial differentiation, as well as garner and investigate how multifunctional rural transition (MRT) responds to economic growth. This paper employed the concept of sample transect to compensate for data deficiencies in a long temporal series and established the indicator system from three different aspects-living function, production function, and ecological function-to measure MRT along China's Yangtze River Transect. Our analysis showed that living function and production function display an increasing trend from underdeveloped western regions to eastern economically prosperous regions, and represent a high degree surrounding urban agglomerations, while economic growth only leads to a statistically insignificant decreasing trend in ecological function. The MRT resulting from multiple factors is much diverse, complex, and sophisticated; therefore, it should be understood within a framework incorporating both endogenous and exogenous factors. According to the results, it is thus important to formulate differentiated managerial countermeasures corresponding to the economic development level rather than the uniform regulations.

Low Field Magnetic Stimulation Ameliorates Schizophrenia-Like Behavior and Up-Regulates Neuregulin-1 Expression in a Mouse Model of Cuprizone-Induced Demyelination.

White matter and myelin sheath integrity are disrupted in schizophrenia, and non-invasive magnetic brain stimulation targeting these tracts is a promising new therapeutic approach. In particular, deep-brain reachable low field magnetic stimulation (DMS) could alleviate cognitive impairment and depressive-like behaviors in animal models. In this study, we sought to assess the effects of DMS on myelin sheath damage and schizophrenia-like behaviors in the cuprizone-induced demyelination mouse model. Mice were fed cuprizone (copper ion chelating agent, 0.2% w/w mixed with food) for 6 weeks to induce demyelination. During these 6 weeks, mice were stimulated with either sham, low-frequency (LFS, delta frequency) DMS or high-frequency (HFS, gamma Hz) DMS for 20 min each day. Behavioral tests were conducted 24 h after the final DMS session. The myelin sheath was examined by immunohistochemistry and the expression of neuregulin-1 (NRG1)/ErbB4 in the prefrontal cortex was measured with Western blotting. Six weeks of HFS significantly alleviated schizophrenia-like behaviors in cuprizone mice, including improved nesting, social interaction and sensorimotor gating, while LFS improved sensorimotor gating only. HFS and LFS both repaired the myelin sheath and increased the expression of neuregulin-1 and its receptor ErbB4, in the prefrontal cortex of demyelinated mice. Our findings show that DMS is a potential effective neuromodulation technique for the treatment of schizophrenia. One possible mechanism underlying these therapeutic effects could involve the up-regulation of NRG1/ErbB4 signaling in the prefrontal cortex.

Molecularly imprinted solid-phase extraction for the selective determination of 17beta-estradiol in fishery samples with high performance liquid chromatography.

A molecularly imprinted polymer (MIP) has been synthesized by a thermo-polymerization method using methacrylic acid (MAA) as functional monomer, ethylene glycol dimethacrylate (EGDMA) as cross-linker, acetonitrile as porogenic solvent, and 17beta-estradiol as template. The MIP showed obvious affinity for 17beta-estradiol in acetonitrile solution, which was confirmed by absorption experiments. After optimization of molecularly imprinted solid-phase extraction (MISPE) conditions, three structurally related estrogenic compounds (17beta-estradiol, estriol, and diethylstilbestrol) were used to evaluate the selectivity of the MIP cartridges. The MIP cartridges exhibited highly selectivity for E(2), the recoveries were 84.8+/-6.53% for MIPs and 19.1+/-1.93% for non-imprinted polymer (NIP) cartridges. The detection and quantification limits correspond to 0.023 and 0.076 mg L(-1). Furthermore, the MISPE methods were used to selectively extract E(2) from fish and prawn tissue prior to HPLC analysis. This MISPE-HPLC procedure could eliminate all matrix interference simultaneously and had good recoveries (78.3-84.5%).