Background Forage production in the saline-sodic soil of the western Songnen Plain Northeast China depends on irrigation. Therefore, the water use efficiency (WUE) and soil chemical properties are key factors in the overall forage productivity in this water scarce region. Improving forage yield, WUE, and soil properties under irrigation are very important for food and ecological security in this water-deficient region. Additionally, a suitable irrigation schedule for this region is necessary. Methods A field experiment was conducted between 2015 and 2018 to evaluate the effects of irrigation on artificial grassland productivity and the changes in soil chemical properties as well as to plan a reliable irrigation schedule for the western Songnen Plain. Eight irrigation treatments were designed, which depended on the three growth stages of alfalfa. The shoot height (SH), the chlorophyll content (SPAD), the dry yield (DM), the ratio of stem to leaves (SLR), the WUE, the changes in the chemical properties of the soil, and precipitation and evaporation were investigated. Results The SH, DM, WUE, and SLR were significantly increased by irrigation ( P < 0.01). However, the SPAD resulting from irrigation was not significantly higher than the SPAD of CK (no irrigation) ( P < 0.05). In addition, the soil chemical properties at the depth of 0–100 cm were significantly decreased by irrigation P (0.05). For example, the soil electrical conductivity, sodium absorption ratio, and total alkalization were reduced 182–345 μS cm −1 , 8.95–9.00 (mmol c /L) 1/2 , and 3.29–4.65 mmol c L −1 by different irrigation treatments, respectively. Finally, considering the highest WUE of I5 (irrigation at branch stage) (2.50 kg m −3 ), relative high DM of I5 (787.00 g m −2 ), the precipitation, the evaporation, the water resources, and the changes of the soil’s chemical properties, 236.50 mm of irrigation water was recommended at the branching stage of alfalfa for the western Songnen Plain, Northeast China.
In the Songnen Plain, Northeast China, chemical parameters of salt-affected soils were previously obtained from 1:5 soil-to-water (1:5) extracts so that there is no information available for soil salinity and sodicity from the saturated paste (SP) extracts. The work reported here characterized soil salinity and sodicity of SP extracts and compared salinity and sodicity measurements using SP and 1:5 extraction methods from 121 soil samples from various sites of salt-affected soil areas in the Songnen Plain. Electrical conductivity (EC), major cations (Na+, K+, Mg2+, Ca2+), sodium adsorption ratio (SAR), and pH were determined and analyzed using SP extracts and 1:5 extracts. The sodium ion was the predominant cation so that Na+ concentration was close to total cation concentration (TCC). The SAR in the 121 samples was remarkably high; 22 soils had a SAR > 1000 (mmolc L−1)1/2 with a maximum SAR value of 4042.57 (mmolc L−1)1/2 for SP extract. The SAR was highly correlated with EC (r 2 > 0.86, P < 0.0001). The salt-affected soils are predominantly saline-sodic based on the classification of the USDA (1954 U.S. Department of Agriculture (USDA) . 1954 . Diagnosis and improvement of saline and alkali soils . USDA , Washington , DC . [Google Scholar]). Through a regression analysis, total cation concentration was strongly related to EC with slopes of 10.3 and 9.8 without y intercept in SP and 1:5 extracts, respectively. Significant relationships (r 2 > 0.81, P < 0.0001) existed between EC, Na+, and SAR in SP and 1:5 extracts. However, K+, Ca2+, and Mg2+ of SP extracts was not related to those of 1:5 extracts.
Four-octyl itaconate (OI), the itaconate's cell-permeable derivative, can activate Nrf2 signaling via alkylation of Keap1 at its cysteine residues. The current study tested the potential neuroprotective function of OI in hydrogen peroxide (H2O2)-treated neuronal cells.SH-SY5Y neuronal cells and epigenetically de-repressed (by TSA treatment) primary murine neurons were treated with OI and/or H2O2. Nrf2 pathway genes were examined by Western blotting assay and real-time quantitative PCR analysis. Neuronal cell death was tested by the LDH and trypan blue staining assays. Apoptosis was tested by TUNEL and Annexin V assays.In SH-SY5Y neuronal cells and primary murine neurons, OI activated Nrf2 signaling, causing Keap1-Nrf2 disassociation, Nrf2 protein stabilization and nuclear translocation, as well as expression of Nrf2-regulated genes (HO1, NQO1 and GCLC) and ninjurin2 (Ninj2). Functional studies showed that OI attenuated H2O2-induced reactive oxygen species (ROS) production, lipid peroxidation and DNA damage as well as neuronal cell death and apoptosis. shRNA-mediated knockdown, or CRISPR/Cas9-induced knockout of Nrf2 almost abolished OI-induced neuroprotection against H2O2. Keap1 is the primary target of OI. Keap1 knockout by CRISPR/Cas9 method mimicked and abolished OI-induced actions in SH-SY5Y cells. Introduction of a Cys151S mutant Keap1 in SH-SY5Y cells reversed OI-induced Nrf2 activation and anti-H2O2 neuroprotection.OI activates Keap1-Nrf2 signaling to protect SH-SY5Y cells and epigenetically de-repressed primary neurons from H2O2 in vitro.
Abstract Background Glioblastoma multiforme (GBM) is a fatal malignant primary brain tumor in adults. The therapeutic efficacy of chemotherapeutic drugs is limited due to the blood-brain barrier (BBB), poor drug targeting, and short biological half-lives. Multifunctional biomimetic nanodrugs have great potential to overcome these limitations of chemotherapeutic drugs. Methods We synthesized and characterized a biomimetic nanodrug CMS/PEG-DOX-M. The CMS/PEG-DOX-M effectively and rapidly released DOX in U87 MG cells. Cell proliferation and apoptosis assays were examined by the MTT and TUNEL assays. The penetration of nanodrugs through the BBB and anti-tumor efficacy were investigated in the orthotopic glioblastoma xenograft models. Results We showed that CMS/PEG-DOX-M inhibited cell proliferation of U87 MG cells and effectively induced cell apoptosis of U87 MG cells. Intracranial antitumor experiments showed that free DOX hardly penetrated the BBB, but CMS/PEG-DOX-M effectively reached the orthotopic intracranial tumor through the BBB and significantly inhibited tumor growth. Immunofluorescence staining of orthotopic tumor tissue sections confirmed that nanodrugs promoted apoptosis of tumor cells. This study developed a multimodal nanodrug treatment system with the enhanced abilities of tumor-targeting, BBB penetration, and cancer-specific accumulation of chemotherapeutic drugs by combining chemotherapy and photothermal therapy. It can be used as a flexible and effective GBM treatment system and it may also be used for the treatment of other central nervous systems (CNS) tumors and extracranial tumors.
On the basis of the successful experience in studing navigable technique of Xiangjiang River Dayuandu Navigation Complex,the paper discussed the layout principle of the bend reach navigation complex,the optimization pattern of the training mole structure as well as the siltation features at approach channel of the shiplock and its minimixing measures.
It was demonstrated from statistical analysis of acid rain for 1992—2008 that the annual variability of acid rain in Guangzhou changed markedly.For the 17-year period,the average annual pH value of acid rain is 4.05,with the lowest at 3.13 and the highest at 4.53;The average annual frequency of acid rain is 86.9%,with the lowest annual value at 71.8% and the highest at 98.6%.Moreover,acid rain changed obviously in different seasons,with the lowest pH value being in spring and the highest in summer.The average pH value of acid rain also varies from month to month,with February having the lowest pH value and December having the highest.SO42-,Cl-,Ca2+,NH4+ and NO3-were identified as the main ions that influenced the pH value of rainfall in Guangzhou and SO2 and NOx were the main pollutants,a conclusion drawn after analysis of ion composition of rainfall as well as pollution concentration.The formation mechanism of acid rain in Guangzhou is not only related to the pollution source,but also related to weather systems and meteorological features of the boundary layer in the process of pollution migration and diffusion.
Ninety-four saline and alkaline soil samples were collected from the Songnen Plain of Northeast China,and their electrical conductivity(EC),sodium adsorption ratio(SAR),total cation concentration(TCC),and major cations(Na+,Ca2+,Mg2+,K+) concentrations in saturated and in 1∶5 soil/water extracts were determined.The EC,SAR,TCC,and Na+ concentration in saturated and in 1∶5 soil/water extracts had significant correlations,and the established regression equations could be used to convert these parameters in the two extracts.However,no correlations were observed between the K+,Ca2+ and Mg2+ concentrations in saturated and in 1∶5 soil/water extracts.
To study the planosol improving effect of subsoil mixing with different soil-improving materials, five treatments were implemented to investigate the physicochemical properties and the yield. The results showed that the subsoil layer physical properties was improved compared with the control. The soil water content was increased by 3.88%-7.78% in the 20-40 cm layer, and the hardness was reduced by about 50%. The soil permeability was increased and the soil three-phase ratio was improved. The solid phase was decreased by 9.71%-11.91%, liquid phase was increased by 1.24%-15.23%, and gas phase was increased by 4.50%-9.83%. The bulk density was reduced by 14.84%-16.77%, the subsoil layer nutrient contents were improved. The alkali-hydrolyzale nitrogen was increased by 8.24%-20.41%, the available phosphorus was increased by 38.89%-192.59%, the rapidly available potassium was increased by 13.22%-28.10%, and organic matter was increased by 33.84%-167.69%. The soil acidity was reduced with pH increased by 0.42 after lime treatment. The soybean yield was significantly increased by 13.00%-14.47%. In summary, subsoil mixing with soil-improving materials could provide technical support for the improvement of planosol and similar low-yield soils and for the increase in crop yield.
'/%3e%3cuse xlink:href='%23a' transform='rotate(23.036 .093 25.536)'/%3e%3cuse xlink:href='%23a' transform='rotate(45.87 1.273 16.18)'/%3e%3cuse xlink:href='%23a' transform='rotate(69.945 .996 12.078)'/%3e%3cuse xlink:href='%23a' transform='rotate(20.66 -19.689 31.932)'/%3e%3c/svg%3e)