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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. [ABSTRACT FROM AUTHOR]

Objective: Obstructive sleep apnea is closely related to oxidative stress. 4-hydroxy-2,2,6,6-tetramethylpiperidine-1-oxyl (Tempol) can scavenge reactive oxygen species (ROS) and ameliorate oxidative damage in the body. The mechanism by which Tempol alleviates chronic intermittent hypoxia-induced lung injury has rarely been reported. This study aimed to confirm the molecular mechanism by which Tempol alleviates lung injury. Methods: The levels of miR-212-5p and Sirtuin 6 (SIRT6) in injured lungs were analyzed using bioinformatics. In vitro, intermittent hypoxia (IH) treatment induced hypoxia in BEAS-2B cells and we established a model of chronic intermittent hypoxia (CIH) in mouse using a programmed hypoxia chamber. We used HE staining to observe the morphology of lung tissue, and the changes in lung fibers were observed by Masson staining. The levels of inflammatory factors in mouse serum were detected by ELISA, and the levels of the oxidative stress indicators GSH, MDA, SOD and ROS were detected using commercially available kits. Moreover, a real-time qPCR assay was used to detect miR-212-5p expression, and Western blotting was used to detect the levels of SIRT6, HIF-1α and apoptosis-related proteins. CCK-8 was used to detect cell proliferation. Subsequently, we used flow cytometry to detect cell apoptosis. Dual-luciferase gene reporters determine the on-target binding relationship of miR-212-5p and SIRT6. Results: SIRT6 was highly expressed in CIH-induced lung injury, as shown by bioinformatics analysis; however, miR-212-5p expression was decreased. Tempol promoted miR-212-5p expression, and the levels of SIRT6 and HIF-1α were inhibited. In BEAS-2B cells, Tempol also increased proliferation, inhibited apoptosis and inhibited oxidative stress in BEAS-2B cells under IH conditions. In BEAS-2B cells, these effects of Tempol were reversed after transfection with an miR-212-5p inhibitor. miR-212-5p targeted and negatively regulated the level of SIRT6 and overexpression of SIRT6 effectively reversed the enhanced influence of the miR-212-5p mimic on Tempol's antioxidant activity. Tempol effectively ameliorated lung injury in CIH mice and inhibited collagen deposition and inflammatory cell infiltration. Likewise, the therapeutic effect of Tempol could be effectively reversed by interference with the miR-212-5p inhibitor. Conclusion: Inhibition of the SIRT6-HIF-1α signaling pathway could promote the effect of Tempol by upregulating the level of miR-212-5p, thereby alleviating the occurrence of lung injury and providing a new underlying target for the treatment of lung injury. [ABSTRACT FROM AUTHOR]

IrO2 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 IrO2/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 IrO2/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 HClO4. 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 IrO2/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. [ABSTRACT FROM AUTHOR]

In China, grape is one of the top five fruit crops for both bearing acreage and production. Recently, national grape production has been stalling because of an increase in drought events. In order to combat the adverse effects of drought on grape production, it is imperative to understand the historical drought trend and frequency during the growing season. In this study, we focused on agricultural drought during the four growth periods of grape: bud break-flowering, flowering-veraison, veraison-berry maturation, and berry maturation-leaf fall. Based on the weather data from 429 meteorological stations, we computed the Crop Water Deficit Index (CWDI) in the five main grape-growing regions of China: Northeast China, North China, Northwest China, Southwest China, and Southeast China. Then, we evaluated the CWDI-based drought distribution and trend in the study regions, as well as the frequency of different degrees of drought. The results showed that exceptional drought was occurring frequently in Xinjiang Uyghur Autonomous Region, northern Gansu province, and northern Ningxia Hui Autonomous Region. Among the four study growth periods of grape, exceptional drought was the most expansive during bud break-flowering. What's more, exceptional drought coverage during bud break-flowering in the study regions was increasing from 1981 to 2016. Analysis of butterfly structure showed that the occurrence of drought was continuous and persistent in northern China. Our study results could serve as guideposts to highlight Chinese grape production industry's vulnerability to agricultural drought against the background of climate change. [ABSTRACT FROM AUTHOR]

Against the background of global warming, extreme agrometeorological events have become more intense and frequent during the growing season of maize (Zea mays L.). In this study, we focused on the five types of extreme agrometeorological events that greatly affect maize production in Northeast China, including chilling injury, drought, rainstorm, frost, and gale. We averaged the actual timing of phenological events from the study agrometeorological stations and divided the maize growing season into four growth stages: emergence—jointing, jointing—flowering, flowering—kernel milk, and kernel milk—physiological maturity. Based on the historical weather data from 1960 to 2017 in the study region, we derived the values of pertinent indices for the five types of study extreme agrometeorological events during the four selected maize growth stages. The results showed that chilling injury and drought were relatively more frequent during the four growth stages of maize from 1960 to 2017 in the Northeast China. As time goes on during the growing season of maize, the spatial coverage of chilling injury, frost, and gale all showed a decreasing trend. By contrast, the spatial coverage of drought showed an increasing trend during the study growth stages of maize. During growth stages of maize, chilling injury was the main extreme agrometeorological event before the 2000s, while drought became the main extreme agrometeorological event after the 2000s. Identifying the main extreme climate events that could cause yield loss is imperative, and it is important for farmers to acknowledge ongoing changes in these extreme climate events in order to take preventive measures if necessary. [ABSTRACT FROM AUTHOR]

The stability of maize production is essential to global food security. Climate factors, such as temperature, precipitation, and solar radiation, directly affect the development of maize plants and hence the final grain yield. In this study, we investigated the spatial distributions and temporal trends of agro-climatic indices and severe weather indicators during the actual growing season for summer maize in Huanghuaihai region of China. The results showed that during the growing season, accumulated effective thermal time had significantly increased. From R3 to R6, accumulated effective thermal time, effective precipitation, and photosynthesis active radiation all showed an increasing trend, with the rate of 20.3 °C day, 1.1 mm, and 7.3 MJ m−2 per decade, respectively. From VE to R3, most of the study years showed a > 50% ratio of high-temperature days to subtotal days and > 7 consecutive days without available precipitation. During most of the study years, there were at least 0.5 thunderstorm events from V6 to VT stage in the locations of study; days with strong winds accounted for more than half the subtotal days during the V6-VT stage. And potential risk of lodging may be reduced by the decrease in days with strong wind. The results of this study could be used in optimizing agricultural management in summer maize production in order to take advantage of beneficial climatic elements while combating adverse climatic elements. [ABSTRACT FROM AUTHOR]

As the growth in global population has led to greater demands for food and energy, societies have been pressured to increase food production. Closing the gap between current and potential yields is one means of producing more food. In this study, we first identify the gaps between the potential yield and actual on-farm yield of maize for ten climate zones (CZs) in Northeast China (NEC) from 1961 to 2010. We then use trend analysis to assess yield gaps caused by suboptimal water availability (YGw). Finally, we identify the CZs where maize yields could be increased through improved irrigation management. Nonparametric trend analysis showed an estimated regional area-averaged yield gap of 64% between potential yield and actual on-farm yield; this gap decreased by 11.0% per decade over the study period (p < 0.01). Although yield gaps have fallen to 43% during the past decade, on-farm maize yield still accounts for only 57% of potential yield. Therefore, there is still a considerable yield gap in maize production in NEC. Simulation results indicated that the average YGw of 23% in NEC is due to suboptimal water availability. Moreover, in CZs with a positive water deficit, the YGw ranged from 14 to 48%; in the remaining CZs, the YGw ranged from 5 to 13%. We conclude that there are substantial opportunities to increase maize production by up to 2.8 t ha−1 through improved irrigation management in cases where the limited irrigation resources can be improved, especially in CZs that receive less than 450 mm of precipitation during the maize-growing season. [ABSTRACT FROM AUTHOR]

l-3- n-Butylphthalide ( l-NBP) exerts neuroprotective effects in animal models of cerebral ischemia, but its potential benefits in repeated cerebral ischemia-reperfusion (RCIR) injury remain unknown. We investigated the effect of l-NBP on cognitive impairment induced by RCIR in mice. Male C57Bl/6 mice received sham surgery or bilateral common carotid artery occlusion (3 times, 20 min each) and were orally administered preoperative l-NBP (30 mg/kg/day, 7 days), postoperative l-NBP (30 or 60 mg/kg/day, 28 days) or postoperative vehicle (28 days). Learning and memory were assessed by the Morris water maze task and step-down passive avoidance test. Nissl staining was used to identify pathologic changes in the hippocampal CA1 region. The expressions of proteins associated with signaling, apoptosis and autophagy were assessed by quantitative PCR and western blot. RCIR induced deficits in learning and memory that were alleviated by preoperative or postoperative l-NBP administration. Pathologic lesions in the hippocampal CA1 region induced by RCIR were less severe in mice treated with l-NBP. Preoperative or postoperative l-NBP administration in mice receiving RCIR promoted hippocampal expression of phospho-Akt and phospho-mTOR (suggesting activation of Akt/mTOR signaling), increased the Bcl-2/Bax ratio (indicating suppression of apoptosis) and reduced the LC3-II/LC3-I ratio (implying inhibition of autophagy). Preoperative or postoperative l-NBP administration also depressed hippocampal levels of beclin-1 mRNA (indicating suppression of autophagy). These findings suggest that the effect of l-NBP to alleviate learning and memory deficits in mice following RCIR may involve activation of Akt/mTOR signaling and regulation of the expressions of proteins related to apoptosis and autophagy. [ABSTRACT FROM AUTHOR]

As climate changes, suitability zones for the cultivation of some crops may shift. In Northeast China (NEC), it is critically important for the agricultural community (e.g. farmers, advisors) to understand the potential shift in suitable cropping zones for spring maize in order to adapt to climate change. The potential climatic suitability can be defined as how actual temperature and solar radiation conditions match the requirements of crop growth under non-limited situations. Here, we used yield potential to reflect the potential climatic suitability, which is determined by the characteristics of crop, solar radiation, temperature, and photoperiod, given the assumption that water, nutrients, pests, and diseases are not limiting the crop growth. We assessed the annual yield potential of spring maize during 1961-2010 in NEC with APSIM-Maize. And then we analyzed the variations in potential climatic suitability zones and the possible effects of these variations on maize production potential. The results show that growing degree-days (GDD) during the growing season for spring maize universally increased in all the locations of this study during the period of 1981-2010 (period II) as compared to the period of 1961-1980 (period I). A total of 66 % of the locations show a decrease in accumulated sunshine duration (ASD) during the growing season during period II as compared to period I. Both coefficient of variation (CV) of GDD and CV of ASD showed an increase during period II as compared to period I. Under the background of climate change, the potential climatic suitability for spring maize was worsened during the most recent five decades: the yield potential declined and the yield stability decreased. In particular, most of the very suitable zone in Jilin and Liaoning during period I turned into suitable or moderately suitable zone during period II. Meanwhile, the total area of marginally suitable zone and no suitable zone increased by 16 % during period II as compared to period I. We detected a close correlation between the decrease in ASD and the decrease in potential climatic suitability, R = 0.56, p < 0.01. We also found a close correlation between the increase in GDD and the decrease in potential climatic suitability, R = −0.25, p < 0.05. Given the same crop varieties and farming management, the total production potential for spring maize in the entire NEC reduced by 4.3 % during period II as compared to period I. [ABSTRACT FROM AUTHOR]

Understanding how changing climate and cultivars influence crop phenology and potential yield is essential for crop adaptation to future climate change. In this study, crop and daily weather data collected from six sites across the North China Plain were used to drive a crop model to analyze the impacts of climate change and cultivar development on the phenology and production of winter wheat from 1981 to 2005. Results showed that both the growth period (GP) and the vegetative growth period (VGP) decreased during the study period, whereas changes in the reproductive growth period (RGP) either increased slightly or had no significant trend. Although new cultivars could prolong the winter wheat phenology (0.3∼3.8 days per decade for GP), climate warming impacts were more significant and mainly accounted for the changes. The harvest index and kernel number per stem weight have significantly increased. Model simulation indicated that the yield of winter wheat exhibited increases (5.0∼19.4 %) if new cultivars were applied. Climate change demonstrated a negative effect on winter wheat yield as suggested by the simulation driven by climate data only (−3.3 to −54.8 kg ha year, except for Lushi). Results of this study also indicated that winter wheat cultivar development can compensate for the negative effects of future climatic change. [ABSTRACT FROM AUTHOR]

Changing crop variety with different maturity types is one of the most effective ways for agricultural production to adapt to climate change. However, variability of climate resources and disaster risks under varying climate conditions makes selection of the proper variety for a certain region more difficult. Based on climate data from 1951 to 2010 and crop data from 1981 to 2007, the impact of climate change on maturity-type shifts of maize variety, the variability of available climate resources including heat, precipitation, and sunshine duration, and agro-meteorological disaster risks in Northeast China (NEC) were analysed. Larger middle- and late-maturity-type cropping areas were found during the second period (1981-2010) than during the first period (1951-1980). The area planted with early-maturity maize tended to decrease in the north-western portion of NEC. In sensitive cropping areas where the maturity types of spring maize shifted, growing degree days increased by 2.8-11.5 %, and the northern portion showed higher increasing amplitude than the southern portion. In addition, both accumulated precipitation and sunshine duration during the maize-growing season showed a significant increasing trend in the northern portion, although a significant decreasing trend was found in the southern portion of NEC. In conclusion, the maturity-type shift in spring maize caused more exposure to chilling damage and water deficiency in the sensitive cropping areas of NEC. The importance of taking full account of disaster risks was demonstrated when changing maturity types of spring maize to achieve higher production. [ABSTRACT FROM AUTHOR]

Northeast China (NEC) is one of the major agricultural production areas in China and also an obvious region of climate warming. We were motivated to investigate the impacts of climate warming on the northern limits of maize planting. Additionally, we wanted to assess how spatial shifts in the cropping system impact the maize yields in NEC. To understand these impacts, we used the daily average air temperature data in 72 weather stations and regional experiment yield data from Jilin Province. Averaged across NEC, the annual air temperature increased by 0.38 °C per decade. The annual accumulated temperature above 10 °C (AAT10) followed a similar trend, increased 66 °C d per decade from 1961 to 2007, which caused a northward expansion of the northern limits of maize. The warming enabled early-maturing maize hybrids to be sown in the northern areas of Heilongjiang Province where it was not suitable for growing maize before the warming. In the southern areas of Heilongjiang Province and the eastern areas of Jilin Province, the early-maturing maize hybrids could be replaced by the middle-maturing hybrids with a longer growing season. The maize in the northern areas of Liaoning Province was expected to change from middle-maturing to late-maturing hybrids. Changing the hybrids led to increase the maize yield. When the early-maturing hybrids were replaced by middle-maturing hybrids in Jilin Province, the maize yields would increase by 9.8 %. Similarly, maize yields would increase by 7.1 % when the middle-maturing hybrids were replaced by late-maturing hybrids. [ABSTRACT FROM AUTHOR]