Neural Induction Potential and MRI of ADSCs Labeled Cationic Superparamagnetic Iron Oxide Nanoparticle In Vitro

Magnetic resonance imaging (MRI) combined with contrast agents is believed to be useful for stem cell tracking in vivo, and the aim of this research was to investigate the biosafety and neural induction of SD rat-originated adipose derived stem cells (ADSCs) using cationic superparamagnetic iron oxide (SPIO) nanoparticle which was synthesized by the improved polyol method, in order to allow visualization using in vitro MRI. The scan protocols were performed with T2-mapping sequence; meanwhile, the ultrastructure of labeled cells was observed by transmission electron microscopy (TEM) while the iron content was measured by inductively coupled plasma-atomic emission spectrometry (ICP-AES). After neural induction, nestin and NSE (neural markers) were obviously expressed. In vitro MRI showed that the cationic PEG/PEI-modified SPIO nanoparticles could achieve great relaxation performance and favourable longevity. And the ICP-AES quantified the lowest iron content that could be detected by MRI as 1.56~1.8 pg/cell. This study showed that the cationic SPIO could be directly used to label ADSCs, which could then inductively differentiate into nerve and be imaged by in vitro MRI, which would exhibit important guiding significance for the further in vivo MRI towards animal models with neurodegenerative disorders

Challenges for Water Security and Sustainable Socio-Economic Development: A Case Study of Industrial, Domestic Water Use and Pollution Management in Shandong, China

Comprehensive analysis of water use and pollution management plays an important role in regional water security and sustainable socio-economic development. This study applies the environmental Kuznets curve (EKC), Gini index and elasticity coefficient methods to conduct an investigation of industrial and domestic water use and pollution management in Shandong. The results show that industrial water pollution generally displayed a coordinated relationship with socio-economic development, while an uncoordinated relationship occurred between domestic water pollution and socio-economic development. Meanwhile, the Gini index between domestic water use and population in 2017 (0.101) was superior to that of 2003 (0.165), and the Gini index of industrial water use and second industry output in 2017 (0.273) was better than that of 2003 (0.292), indicating that the allocation and equity of domestic and industrial water use in Shandong kept to a good development trend. Additionally, the industrial effect is better than the domestic effect in terms of the control of wastewater emissions and the governance of typical pollutants in wastewater. Accordingly, domestic water pollution has gradually become one of the major sources of water pollution, and the allocation of industrial and domestic water use has room to improve further in Shandong. Conjunctive use of the aforementioned three methods provides an approach to investigate the integrated management of water use and water pollution control from multiple angles

River Ecological Corridor: A Conceptual Framework and Review of the Spatial Management Scope

Studying the spatial management scope of the river ecological corridor is a crucial step in effectively managing river health problems. For various purposes and needs, human beings intervene excessively in the river, resulting in the problems of unclear spatial scope, unclear ownership, and unreasonable functional utilization of the river ecological corridor. However, there is scarce research on the management scope of the river ecological corridor at present, and on the coordination relationship with territorial spatial protection planning. Therefore, in order to solve this key problem, this paper reviews and summarizes the current research status and development trends in terms of the concept, components, and other basic theories of the river ecological corridor, as well as relevant policy regulations. The relationship between the spatial scope of the river ecological corridor and the territorial spatial control line is analyzed, including the relationship with the river shoreline, aquatic ecological redline, “three control lines” and other control lines. Accordingly, this study reviewed the spatial management and control scope of the river ecological corridor. It also determined that the boundary line of the river shoreline management is the minimum line, the aquatic ecological redline, and the “three control lines” are the outermost boundary lines, in which the aquatic ecological redline has priority over other control lines. It also points out the thinking of determining the management scope in the protection and restoration of the river ecological corridor in the future. Our findings can provide a decision-making basis for the management of river ecological space

Pore size dependent connectivity and ionic transport in saturated cementitious materials

Microstructure-property relationship has drawn strong attention in modern material science. The progress achieved in this field relies on a common basis that the material performance originates from the microstructure. This paper brings together new insights and facts from experiments regarding the pore size dependent connectivity and its relation to ionic transport property in saturated cementitious materials. An innovative measurement, i.e. intrusion-extrusion cyclic mercury porosimetry (IEC-MIP), is proposed to distinguish between the small capillary pores that are present within clusters of hydration products and the large capillary pores that are left out of hydration products. The distribution of connectivity as a function of pore size in cementitious materials is analyzed. A novel transport parameter, i.e. connectivity of small capillary pores, is introduced and quantified by IEC-MIP measurements. The ionic transport was measured by means of rapid chloride migration tests. A power relationship is established between connectivity of small capillary pores and chloride migration coefficient for cementitious materials irrespective of the binder type.Accepted Author ManuscriptMaterials and Environmen

Dependence of unsaturated chloride diffusion on the pore structure in cementitious materials

Conceptual analysis is performed to examine the effects of pore features on the water continuity in unsaturated porous systems. The roles of pore features in relative chloride diffusion coefficient (Drc) of mortar specimens at various degrees of water saturation (Sw) were studied based on mercury intrusion porosimetry and resistivity tests. It is found that the role of pore structure in the Drc-Sw relationship is a result of its effect on the water continuity. Porosity and tortuosity are not relevant to the Drc-Sw relationship. A finer pore size distribution or lower pore connectivity tends to result in a lower Drc. The pore size effect on the Drc is pronounced primarily at high Sw, while the Drc is dominated by the pore connectivity at low Sw. Cement mortar with a higher water-to-binder ratio shows larger chloride diffusion at high relative humidity levels but smaller chloride diffusion at low relative humidity levels.Accepted Author ManuscriptMaterials and Environmen

New insights into long-term chloride transport in unsaturated cementitious materials: Role of degree of water saturation

Concrete is rarely saturated. Reliable durability design of marine concrete structures requires a solid understanding of the long-term chloride transport in unsaturated concretes. This paper presents a critical analysis of the time-dependent chloride diffusion coefficient in unsaturated cementitious materials exposed to marine environment. Evolutions of pore structure and chloride diffusion coefficient in saturated cementitious materials, along with the role of the degree of water saturation in long-term chloride diffusion, are analyzed. It is emphasized that the long-term sharp decrease of the chloride diffusion coefficient in marine cementitious materials is not primarily caused by densification of the microstructure due to hydration, but by the decreasing degree of water saturation with depth in the surface part of the materials. The effects of water/binder ratio and supplementary cementitious materials on chloride diffusion coefficient are different between saturated and unsaturated cementitious materials.Accepted Author ManuscriptMaterials and Environmen

The Effect of Moisture Content on the Electrical Properties of Graphene Oxide/Cementitious Composites

Due to its ability to improve mechanical properties when incorporated into cement, graphene oxide (GO) has received extensive attention from scholars. Graphene oxide is also a filler that improves the self-sensing properties of cement composites (CCs). However, existing studies have not focused sufficient attention on the electric conductivity of cement composites filled with graphene oxide (GO/CCs) and their mechanisms, especially polarization. This study examines the effects of water content and temperature on the electrical conductivity of GO/CCs. GO/CC polarization phenomena are analyzed to reveal the conductive mechanism. The results show that water has a significant influence on the electrical conductivity of GO/CCs. With increasing water loss, the electrical resistivity of GO/CCs increases by four orders of magnitude. For the same water content, a 0.1% GO concentration significantly decreases the resistivity of GO/CCs. Temperature can significantly enhance the current intensity of GO/CCs; furthermore, there is a quadratic relationship between current intensity and temperature. The conductive mechanism of GO/CCs is attributed to the interaction between ionic conductivity and electronic conductivity

Microstructure-based relative humidity in cementitious system due to self-desiccation

The internal relative humidity (RH) plays a crucial role in most of the concrete properties. Self-desiccation caused by continuous cement hydration is a major factor affecting the RH of concrete. This paper investigates the relationship between RH and microstructure for cementitious systems in the case of self-desiccation. A series of paste specimens prepared with different binder and water-binder-ratio (w/b) were cured under sealed conditions from 1 day to 1.5 years. The RH and microstructure of the paste specimens were measured. The microstructure characteristics under study include porosity, pore size, evaporable and non-evaporable water content. The results reveal that the RH of cementitious system drops to a great extent in the first 105 days' hydration and decreases slowly afterwards. The blended materials such as fly ash, slag or limestone powder have different influences on the RH. A mathematical model between RH and the average pore diameter is proposed for cementitious systems under self-desiccation, regardless of age, w/b or cement type.Materials and Environmen

Compatibility and Photocatalytic Capacity of the Novel Core@shell Nanospheres in Cementitious Composites

In this paper, a novel core@shell nanosphere (TiO2@CoAl-LDH) based on layered double hydroxide (LDH) combined with a nano-TiO2 semiconductor was synthesized and introduced to cementitious materials via spraying technology and a smearing method. The compatibility with a cementitious matrix and the effects of TiO2@CoAl-LDH on cement hydration, surface microstructure, and the microscopic mechanical properties of mortar were investigated by AFM, microhardness testing, FESEM, and BET analysis. Meanwhile, the effects of TiO2@CoAl-LDH introduction methods on the photocatalytic performance and durability of the photocatalyst were systematically evaluated by methylene blue (MB) removal ratio and wear testing. The results show that TiO2@CoAl-LDH exhibits enhanced compatibility with cementitious matrices and a higher photocatalytic capacity than individual CoAl-LDH and nano-TiO2. The photocatalytic mortar prepared via spraying technology (CM-C) displays a higher photocatalytic capacity than that prepared via the smearing method (CM-S). Among them, the mortar with two layers of photocatalytic coatings (CM-C2) has the highest MB removal ratio, which reached 95.1% within 120 min of UV-visible light irradiation. While on the other hand, the wear test revealed that the smeared mortar has a higher photocatalytic capacity and better photocatalyst durability than the sprayed mortar. This work is expected to contribute to the development of multifunctional sustainable building materials