Oxygen-Glucose Deprivation Induced Glial Scar-Like Change in Astrocytes

It has been demonstrated that cerebral ischemia induces astrocyte reactivity, and subsequent glial scar formation inhibits axonal regeneration during the recovery phase. Investigating the mechanism of glial scar formation will facilitate the development of strategies to improve axonal regeneration. However, an in vitro model of ischemia-induced glial scar has not yet been systematically established.In the present study, we at the first time found that oxygen-glucose deprivation (OGD) in vitro can induce rat cortical astrocytes to present characteristics of glial scar. After OGD for 6 h, astrocytes showed a remarkable proliferation following 24 h reperfusion, evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay and BrdU immunocytochemistry. Meanwhile, the expression of glial fibrillary acidic protein significantly increased, so did the expression of neurocan, which is a hallmark of the glial scar. In further experiments, neurons were co-cultured with astrocytes, which had been exposed to OGD, and then the immunostaining of class III β-tubulin was carried out to assess the neurite growth. When the co-culture was performed at 48 h reperfusion of astrocytes, the neurite growth was obviously inhibited, and this inhibition could be reversed by chondroitinase ABC, which digests glycosaminoglycan chains on CSPGs, including neurocan. However, the processes of neurons were elongated, when the co-culture was performed immediately after OGD.Our results indicated that after conditioned OGD the astrocytes presented the characteristics of the glial scar, which are also comparable to the astrocytes in acute and chronic phases after cerebral ischemia in vivo. Therefore, the present system may be used as an in vitro model to explore the mechanisms underlying glial scar formation and the treatments to improve axonal regeneration after cerebral ischemia

Evaluation of Forest Conversion Effects on Soil Erosion, Soil Organic Carbon and Total Nitrogen Based on ¹³⁷Cs Tracer Technique

Soil erosion can affect the horizontal and the vertical distribution of soil carbon at the landscape scale. The 137Cs tracer technique can overcome the shortcomings of traditional erosion research and has proven to be the best method to study soil erosion. To understand the responses of soil organic carbon and nitrogen to soil erosion and forest conversion in the development of slope economic forests in rocky mountain areas, three representative types of economic forests that were all formed after clear-cutting and afforestation on the basis of CBF (coniferous and broad-leaved mixed forests) were selected: CF (chestnut forests) with small human disturbance intensity, AF (apple forests), and HF (hawthorn forests) with high interference intensity. The results showed that all land use types have significantly eroded since 1950; the average annual loss of soil was 0.79 mm in the CBF, 2.31 mm in the AF, 1.84 mm in the HF, and 0.87 mm in the CF. The results indicated aggravation of soil erosion after the transformation of the CBF into an economic forest. The economic forest management reduced the average carbon storage and accelerated nutrient loss. The better vegetation coverage and litter coverage of CF made them stand out among the three economic forest varieties. Therefore, when developing economic forests, we should select species that can produce litter to ensure as much soil conservation as possible to reduce the risk of soil erosion

Enhancement of barrier and corrosion protection performance of vinyl ester resin coating via incorporation of MXene nanosheets

Anti-corrosion performance of a vinyl ester resin coating was enhanced by intercalation of MXene nanosheets in the resin matrix through wet transfer method. Open circuit potential and electrochemical impedance spectroscopy tests was executed to evaluate the barrier and corrosion protection performance of the VER and MXene/VER composite coatings. The results revealed significant enhancement of the corrosion protection performance of the MXene/VER composite coating samples compared with that of the VER coating samples. The real impendence values of VER and MXene/VER composite coatings was 1.83 and 5.87 MΩ cm2, and the coating resistance was 1.72 and 5.74 MΩ cm2 after 40-days soaking in the 3.5 wt % of NaCl solution, respectively. The results indicate that the 0.1 wt % MXene/VER composite coating exhibited a significant improvement of coating resistance and real impendence by up to 320% and 330%, respectively. The impermeability makes the 2D MXene nanosheets acting as a good barrier to corrosive electrolyte, leading to a more tortuous diffusion pathway and enhanced corrosion protection performance

Application of the Real-Time Kinematic Global Positioning System in Bridge Safety Monitoring

A real-time kinematic (RTK) global positioning system (GPS) has been developed and installed on the Human Bridge (China) for on-line monitoring of bridge deck movement, which may occur as a result of seismic activity, traffic load, and such environmental elements as temperature and wind. This paper presents the main features of the on-line GPS RTK system and its value for on-line safety monitoring

Supplementary data for the quantum chemical calculation of free radical substitution reaction mechanism of camptothecin

This data article contains the truncated view of the transition states for methyl radical attacking camptothecin at the site of 9, 10, 11, 12 and 14 in acidic conditions obtained from quantum computation of Gaussian 09 with B3LYP/6–31+G(d,p) level, also the truncated view of transition states for H abstraction by singlet O2 from sites of 9, 10, 11 and 12 of the intermediates of methyl combination with camptothecin and that by triplet O2 from site 9 of the intermediate of methyl combination with camptothecin in acidic condition are included. The corresponding parameters of reaction rate constant calculation for the formation of methyl radical from acetaldehyde, the first and second step of radical substitution of camptothecin under acidic conditions are listed. The data of the basic parameters for the computation of the total energy of the spin-projection of singlet oxygen, and the S2 values for the reactants, transition states and intermediates in the free radical substitution reaction of camptothecin are also included

Two-Step Solvothermal Synthesis of (Zn0.5Co0.5Fe2O4/Mn0.5Ni0.5Fe2O4)@C-MWCNTs Hybrid with Enhanced Low Frequency Microwave Absorbing Performance

In this study, the quaternary hybrid of (Zn0.5Co0.5Fe2O4/Mn0.5Ni0.5Fe2O4)@C-MWCNTs with high-performance in low frequency electromagnetic absorption was synthesized via a facile two-step solvothermal synthesis method. The physicochemical properties as well as electromagnetic parameters and microwave absorption performance were characterized by XRD, SEM, TEM, RS, TGA, and VNA, respectively. The results indicate a nuclear-shell morphology of this hybrid for amorphous carbon coated on the surface of Zn0.5Co0.5Fe2O4 and Mn0.5Ni0.5Fe2O4 mixed polycrystalline ferrites. In addition, the MWCNTs synchronously enwind in the nuclear-shell NPs to form a special cross-linking structure. The outstanding low frequency microwave absorption property is attributed to the synergistic effect of dielectric and magnetic loss, better impedance matching condition, and excellent attenuation characteristics of the as-prepared paramagnetic quaternary hybrid. Maximum RL of −35.14 dB at 0.56 GHz with an effective absorption bandwidth in the range of 0.27–1.01 GHz can be obtained with thickness of 5 mm. This hybrid exhibits superior low frequency microwave absorption properties compared with other ferrite-carbon nanocomposites. This investigation provides a new route to prepare suitable candidates for the absorption of electromagnetic waves in a low frequency band on account of its good performance and simple preparation process

DataSheet_1_Efficient virus-mediated genome editing in cotton using the CRISPR/Cas9 system.docx

Plant virus-mediated sgRNA delivery and expression have great advantages; sgRNA expression can rapidly expand and accumulate along with virus replication and movement, resulting in efficient gene editing efficiency. In this study, a VIGE system based on cotton leaf crumple virus (CLCrV) was established using cotton overexpressing Cas9 (Cas9-OE) as the VIGE receptor. CLCrV-mediated VIGE could not only target and knock out the GhMAPKKK2, GhCLA1 and GhPDS genes subgroup A and D genome sequences but also achieve double mutation of GhCLA1 and GhPDS genes at the same time. These results verified the effectiveness and efficiency of this system. In addition, the off-target effect assay demonstrated that the CLCrV-mediated VIGE system not only has high gene editing efficiency but also high gene editing specificity in cotton. We further explored whether the FT-sgRNA strategy could transport sgRNA to cotton apical meristem (SAM) over long distances to avoid using tissue culture to obtain stable genetic mutants. The results showed that the sgRNA fused with FT mRNA at the 5’ end could also efficiently achieve targeted editing of endogenous genes in cotton, but it was difficult to detect heritable mutant progeny. The above results showed that the CLCrV-mediated VIGE system provided an accurate and rapid validation tool for screening effective sgRNAs in cotton.</p