•Nimodipine provides neuroprotection against VD by activating the Akt/CREB signalling pathway.•Autophagy has a protective effect on rats after chronic cerebral hypoperfusion.•Autophagy can be part of ...integrated survival of the Akt/CREB pathway.
The Akt/CREB signalling pathway is involved in neuronal survival and protection. Autophagy is also likely to be involved in survival mechanisms. Nimodipine is an L-type calcium channel antagonist that reduces excessive calcium influx during pathological conditions (contributing to its neuroprotective properties). However, the potential role of nimodipine in autophagic and Akt/CREB signalling is not well understood. In addition, little is known about the relationship between autophagic and Akt/CREB signalling. Here, we designed a way to evaluate these issues. Adult male Sprague-Dawley rats were subjected to permanent bilateral occlusion of the common carotid artery (2VO) and randomly divided into three groups: the Vehicle (2VO), Nimodipine10 (2VO+nimodipine 10mg/kg), and Nimodipine20 (2VO+nimodipine 20mg/kg) groups. A fourth group of animals served as Sham controls. Each group was investigated at 4 and 8 weeks post-operatively and assessed using the Morris water maze. Nimodipine significantly alleviated spatial learning and memory impairments and inhibited the loss of neurons in the CA1 region of the hippocampus. These drug effects were more pronounced at 8 weeks than at 4 weeks. The activities of LC3 II p-Akt and p-CREB were examined using immunohistochemistry and western blotting. Suppressing autophagy induced pyramidal cell death without affecting increased pro-survival signalling induced by nimodipine. Nimodipine protected the brain from chronic cerebral hypoperfusion by activating the Akt/CREB signalling pathway. Autophagy has a neuroprotective effect on rats after 2VO. Autophagy is likely part of an integrated survival signalling network involving the Akt/CREB pathway.
•Adopting new varieties partially offsets the negative effects of climate change on crop yields.•The effects of hybrid management on maize yield were demonstrated with multiple datasets.•Regional ...warming shortened the length of the growing season, especially the vegetative period.•The improvement in maize grain yield became more evident as the latitude increased.
Adopting new cultivars is an effective strategy to partially offset the negative effects of climate change on crop yields. We integrated the regional agro-meteorological observations, site-level field experiment data, and a process-based crop model to assess the effects of maize hybrid management on grain yield at meteorological sites across Northeast China. On a regional scale, for per 1 ℃ increase in Tmin (Tmax) at the agro-meteorological stations, the length of the entire actual growing period for maize was shortened by 3.6 (2.3) days per year. Without changing maize hybrids, maize grain yield could be in jeopardy. Adopting hybrids with relatively longer growing period could take full advantage of the regional warming trend and hence improve the maize grain yield. In this study, we found that adopting novel hybrids (bred through trait selection and propagation during the past four decades) could improve maize grain yield in Northeast China. This conclusion was supported by the two-year field experiment that used nine prevailing newly-bred hybrids and the well-validated crop modeling at 74 locations covering a 60-year period (from 1961 to 2020). Compared with using the same hybrid, changing hybrid adapted the maize production to climate change in Northeast China; and the regional maize grain yield was increased by 5.4%, 7.4%, 6.8%, and 10.3%, respectively, due to changes in, respectively, solar radiation, Tmax, Tmin, and precipitation. The improvement in maize grain yield became more evident as latitude increased, especially at locations to the north of 42.5ºN. In the future, changing hybrid may increase the region-simulated maize grain yield by 6.2 and 7.2% under the scenarios of SSP-126 and SSP-585, respectively. In sum, adopting newly-bred maize hybrids, especially those with relatively long growing periods, would be an effective measure to adapt regional maize production to climate change in Northeast China.
Electrocatalytic reduction reactions play a crucial role in electrochemical energy conversion and storage technology, which are emerging technologies to ameliorate environmental problems. Spinel ...oxides are widely explored in electrocatalytic oxidation reactions but have a poor intrinsic ability to reduction reactions, making their electrocatalytic ability less effective. To improve this, defect engineering is a valuable method for regulating the electronic structure and coordination environment. Herein, this manuscript discusses the use of defect spinel oxides in electrocatalytic reduction reactions, including the different types of defects, construction methods, and characterization techniques. It also outlines the various applications of defect spinel oxides in different electrocatalytic reduction reactions. Finally, it goes over the challenges and future outlooks for defect spinels. This review aims to thoroughly explain how defect spinels work in electrocatalytic reduction reactions and serve as a helpful guide for creating effective electrocatalysts.
Closing the gap between current and potential yields is one means of increasing agricultural production to feed the globally increasing population. Therefore, investigation of the geographic ...patterns, trends and causes of crop yield gaps is essential to identifying where yields might be increased and quantifying the contributions of yield-limiting factors that may provide us potentials to enhance crop productivity. In this study, the changes in potential yields, attainable yields, potential farmers' yields, and actual farmers' yields during the past five decades in Northeast China (NEC) were investigated. Additionally the yield gaps caused by non-controllable, agronomic, and socioeconomic factors were determined. Over the period 1961 to 2010 the estimated regional area-weighted mean maize potential yield, attainable yield, and potential farmers' yield were approximately 12.3tha−1, 11.5tha−1, and 6.4tha−1 which showed a decreasing tendency. The actual farmers' yield over NEC was 4.5tha−1, and showed a tendency to increase (p<0.01) by 1.27tha−1 per decade. The regional mean total yield gap (YGt), weighted by the area in each county dedicated to maize crop, was 64% of potential yield. Moreover, 8, 40, and 16% reductions in potential yields were due to non-controllable factors (YGI), agronomic factors (YGII), and socioeconomic factors (YGIII), respectively. Therefore, the exploitable yield gap, considered here as the difference between the potential yield and what one can expect considering non-controllable factors (i.e. YGt–YGI), of maize in NEC was about 56%. The regional area-weighted averages of YGt, and YGIII were found to have significant decreases of 11.0, and 10.7% per decade. At the time horizon 2010, the exploitable yield gaps were estimated to equal 36% of potential yield. This led to the conclusion that the yield gap could be deeply reduced by improving local agronomic management and controlling socioeconomic factors.
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•The actual farmers' yield showed a tendency to increase by 1.27tha−1 per decade.•Maize yield gaps due to non-controllable, agronomic, and socioeconomic factors were identified.•We suggest government and farmers focus on reducing yield gap by improving agronomic practices.
The Northeast China (NEC) accounts for more than 30% of the national total maize planted area (grain yield). Adjusting the sowing dates has been considered an effective measure to adapt to climate ...change, but there was little evidence that how well the producers had done. In this study, we used phenology observations at 67 stations from 1981 to 2014 to detect trends in actual sowing dates, then the agricultural production systems simulator, APSIM-Maize model, was used to assess the effects of changes in observed sowing dates on maize phenology and yields. During the past 34-year period, the actual maize sowing dates show a delaying tendency, at a rate of 1–6 days per decade, but there are significant fluctuations among years. For per day delay in the sowing dates, the whole growing season was shortened by 0.1%. Delaying sowing dates reduced the solar radiation interception during the vegetative period as well as the thermal time during the reproductive period. As a result, the overall maize potential yield was negatively affected in NEC; for per day delay in the sowing dates, the potential yield was decreased by 0.6%. By contrast, advancing sowing dates in some years led to increases in both the solar radiation interception during the vegetative period and the thermal time during the reproductive period. However, these increases showed various effects on the maize potential yield across different parts of the study region. We detected a positive effect of advancing sowing dates on maize potential yield in the high latitudes, at a rate of up to 1.6%. By contrast, in the low latitudes, the negative effect of advancing sowing dates on maize potential yield was dominant, at a rate of up to 2.7%.
•The observed sowing dates mostly delayed but fluctuated greatly among years.•The potential yield was decreased by 0.6% for per day delay in sowing dates.•The potential yield at high latitude and low latitude changed result differently.
IrO
2
exhibits good stability but limited electrocatalytic activity for oxygen evolution reaction in acid. Defect engineering is an effective strategy to improve the intrinsic ability of ...electrocatalysts by tailoring their electronic structure. Herein, we have successfully synthesized IrO
2
/Ir heterophase with compressive strain and metal vacancies via a simple substitution-etching method. In virtue of the solubility of Cr in strong alkali, metal vacancies could be formed at surface after etching Cr-doped IrO
2
/Ir in alkali, which leaded to modulated electronic structure. Meanwhile, the substitution of Cr with smaller atom radius would induce the formation of compressive strain and the relocated atoms made the d-band center shifted. With the regulated electronic structure and tuned d-band center, the obtained electrocatalyst only needed 285 mV to reach 10 mA·cm
−2
in 0.1 M HClO
4
. Reaction kinetic has been rapidly accelerated as indicated by the smaller Tafel slope and charge transfer resistance. Theoretical calculations revealed that the d-band center and charge density distribution have been regulated with the introduction of defects in IrO
2
/Ir, which significantly decreased the free energy barrier of rate determining step. This work provides a valuable reference to design effective and defects-rich electrocatalysts.
Reactive Oxygen Species (ROS) play an essential role in the pathogenesis of osteoporosis mainly characterized by excessive osteoclasts (OCs) activity. OCs are rich in mitochondria for energy support, ...which is a major source of total ROS. Tussilagone (TSG), a natural Sesquiterpenes from the flower of Tussilago farfara, has plentiful beneficial pharmacological characteristics with anti-inflammatory and anti-oxidative activity, but its effects and mechanism in osteopathology are still unclear. In our study, we investigated the regulation of ROS generated from the mitochondria in OCs. We found that TSG inhibited OCs differentiation and bone resorption without any cytotoxicity. Mechanistically, TSG reduced RANKL-mediated total ROS level by down-regulating intracellular ROS production and mitochondrial function, leading to the suppression of NFATc1 transcription. We also found that nuclear factor erythroid 2-related factor 2 (Nrf2) could enhance ROS scavenging enzymes in response to RANKL-induced oxidative stress. Furthermore, TSG up-regulated the expression of Nrf2 by inhibiting its proteosomal degradation. Interestingly, Nrf2 deficiency reversed the suppressive effect of TSG on mitochondrial activity and ROS signaling in OCs. Consistent with this finding, TSG attenuated post-ovariectomy (OVX)- and lipopolysaccharide (LPS) induced bone loss by ameliorating osteoclastogenesis. Taken together, TSG has an anti-bone resorptive effect by modulating mitochondrial function and ROS production involved Nrf2 activation.
Improving the adsorption selectivity, enhancing the extraction capacity, and ensuring the structural stability of the adsorbent are the key to realize the high efficiency recovery of uranium. In this ...work, we utilized the strong Lewis acid–base interaction between S2– and U(VI)O2 2+ coupling rapid electron transfer at the MnS/U(VI)O2 2+ solid–liquid interface to achieve excellent selectivity, high adsorption capacity, and rapid extraction of uranium. The as-synthesized MnS adsorbent exhibited an ultrahigh uranium extraction capacity (2457.05 mg g–1) and a rapid rate constant (K = 9.11 × 10–4 g h–1 mg–1) in seawater with 100.7 ppm of UO2(NO3)2 electrolyte. The kinetic simulation reveals that this adsorption process is a chemical adsorption process and conforms to a pseudo-second-order kinetic model, indicating electron transfer at the MnS/U(VI)O2 2+ solid–liquid interface. The relevant (quasi) in situ spectroscopic characterization and theoretical calculation results further revealed that the outstanding uranium extraction property of MnS could be attributed to the highly selective UO2 2+ adsorption of MnS with lower adsorption energy as a result of the strong interaction between S2– and UO2 2+ and the rapid mass transfer and interface electron transfer from S2– and low-valent Mn(II) to U(VI)O2 2+.
Soybean is an important oil crop in China, and the national focus of soybean production is in Northeast China. In order to achieve high-stable yield, it is crucial to acknowledge the impacts of mean ...climate and extreme climate indices on soybean yield and yield components. In this study, based on the weather data from 61 counties from 1981 to 2017 in Northeast China, we assessed the impacts of mean climate and extreme climate indices on soybean observed yield and simulated yield. Mean climate include effective growing degree days (GDD10), precipitation (Pre), and solar radiation (SR); extreme climate indices include the number of cool days during seed-filling period (C15), the number of cool days during 15 days before anthesis (C17), the number of hot days (H30), maximum amount of 5 Day accumulated precipitation (P5), and consecutive dry days (CDD)). We used the DSSAT-CROPGRO-Soybean model to identify the main yield components for soybean. The results showed that observed soybean yield reduced by 3.57% due to the collective changes in the eight study climate indices. Increases in GDD10, decreases in Pre, and decreases in SR caused a 3.96%, −3.89%, and − 0.48% change in soybean yield, respectively. Decreases in C15 and C17 led to a 5.36% increase in soybean yield; increases in H30, P5, and CDD caused a 5.75%, 0.30%, and 1.14% reduction in soybean yield, respectively. By comparing the response of observed and simulated soybean yield to climate indices (excluding P5) in the DSSAT-CROPGRO-Soybean model, we identified the key yield components for soybean as the number of pods and seed weight. The negative impacts on the number of pods and seed weight were mainly attributed to changes in Pre and H30 from anthesis to podding and during seed-filling period. Our results could be used to assist the local soybean community adapt to climate change.
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•Mean climate, extreme climate indices and climate change decreased soybean yield.•Soybean yield was mostly attributed to the number of pods and seed weight.•Changing in Pre and H30 mainly decreased the number of pods and seed weight.
SignificanceDynamically understanding the microscopic processes governing ordering transformations has rarely been attained. The situation becomes even more challenging for nanoscale alloys, where ...the significantly increased surface-area-to-volume ratio not only opens up a variety of additional freedoms to initiate an ordering transformation but also allows for kinetic interplay between the surface and bulk due to their close proximity. We provide direct evidence of the microscopic processes controlling the ordering transformation through the surface-bulk interplay in Pt-Fe nanoalloys and new features rendered by variations in alloy composition and chemical stimuli. These results provide a mechanistic detail of ordering transformation phenomena which are widely relevant to nanoalloys as chemical ordering occurs in most multicomponent materials under suitable environmental bias.
