Due to the intensity of urban development around the world, there is an increasing body of studies attempting to investigate urban heat island (UHI) in various spatial and temporal scales. In surface ...heat urban island (SUHI) studies, extended periods of time, broader regions and local government area (LGA) level have become more crucial and will shed light on causes of UHI. Moreover, the spatial pattern and structure of SUHI will be useful for policy-makers to develop mitigation strategies. This study focused on three objectives. Firstly, analyzing land surface temperature (LST), normalized difference built-up (NDBI) and vegetation (NDVI) indices. Secondly, investigating interrelationships among LST, NDVI, and NDBI. Thirdly, identifying LST patterns in the Melbourne metropolitan area. These objectives were achieved through three different methods. The modified automatic mapping method for the first objective, the correlation analysis for the second, and spatial statistical methods for the third. The methodological innovations of this study were considering LGA in interrelationship analysis among LST, NDBI and NDVI, and calculation of NDVI for each acquisition date. The results indicated that the clustering pattern of LST expanded toward the north-west and south-east during the period of the study. Furthermore, the north-west part of the city has the highest positive (0.6) correlation between NDBI and LST, and the south-east part of the city has the lowest negative (−0.8) correlation between NDVI and LST. The most significant increase and decrease in mean LST happened respectively from January 6th to 22nd 2017, and January 14th to 30th January 2014. The temperature degree altered from 19.61 °C to 27.86 °C in inner western suburbs, and from 35.49 °C to 26.88 °C in most LGA's. These findings are critical for planners to localize UHI mitigation action plans, target hot spots in LGA's and allocate resources to respond to the adverse effect of UHI.
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•Time-series satellite imagery and spatial statistical used to determine the LST spatial structure at the local government level.•LST calculated by the modified mapping method and NDVI calculated for each acquisition dates from Landsat satellite images.•Overall, clustering patterns of LST expanded toward the north-west(NW) and south-east(SE) in Melbourne•NW part has the highest positive correlation between NDBI and LST; SE part has lowest negative correlation for NDVI and LST
Oxidative stress reflects an imbalance between the overproduction and incorporation of free radicals and the dynamic ability of a biosystem to detoxify reactive intermediates. Free radicals produced ...by oxidative stress are one of the common features in several experimental models of diseases. Free radicals affect both the structure and function of neural cells, and contribute to a wide range of neurodegenerative diseases, including Parkinson's disease and Alzheimer's disease. Although the precise mechanisms that result in the degeneration of neurons and the relevant pathological changes remain unclear, the crucial role of oxidative stress in the pathogenesis of neurodegenerative diseases is associated with several proteins (such as α-synuclein, DJ-1, Amyloid β and tau protein) and some signaling pathways (such as extracellular regulated protein kinases, phosphoinositide 3-kinase/Protein Kinase B pathway and extracellular signal-regulated kinases 1/2) that are tightly associated with the neural damage. In this review, we present evidence, gathered over the last decade, concerning a variety of pathogenic proteins, their important signaling pathways and pathogenic mechanisms associated with oxidative stress in Parkinson's disease and Alzheimer's disease. Proper control and regulation of these proteins' functions and the related signaling pathways may be a promising therapeutic approach to the patients. We also emphasizes antioxidative options, including some new neuroprotective agents that eliminate excess reactive oxygen species efficiently and have a certain therapeutic effect; however, controversy surrounds some of them in terms of the dose and length of therapy. These agents require further investigation by clinical application in patients suffering Parkinson's disease and Alzheimer's disease.
In order to clarify the effect of pulsating fracturing on gas comprehensive desorption, experimental study of gas desorption characteristics effected by the pulsating hydraulic fracturing (PHF) and ...static hydraulic fracturing (SHF) were carried out, the gas displacement amount (GDA) and natural desorption amount (NDA) under different hydraulic fracturing methods are investigated. The results show that the GDA generated by the SHF is significantly less than the PHF. At the same time, the GDA increases linearly first, and then logarithmically with the fracturing frequency; with the increase of pulsating peak pressure, it showed a logarithmic increase. The water has an inhibitory effect on the natural desorption of gas. With the increase of pulsating pressure and frequency, the effect of pulsation fracturing suppressing the natural desorption of gas is weakened. According to the effect of different fracturing methods on gas desorption, the PHF is divided into four types: low pressure-low frequency, low pressure-high frequency, high pressure-low frequency and high pressure-high frequency. Because the gas displacement rate (ƞd) determines the changes of gas comprehensive desorption effect, the low pressure-low frequency inhibits gas desorption, while the low pressure-high frequency, high pressure-low frequency and high pressure-high frequency can promote gas desorption. The results provide theoretical guidance for optimizing pulsating parameters, increasing gas desorption and promoting coal seam gas drainage.
Although previous studies have found that melatonin can promote seed germination, the mechanisms involved in perceiving and signaling melatonin remain poorly understood. In this study, it was found ...that melatonin was synthesized during cucumber seed germination with a peak in melatonin levels occurring 14 hr into germination. This is indicative of a correlation between melatonin synthesis and seed germination. Meanwhile, seeds pretreated with exogenous melatonin (1 μm) showed enhanced germination rates under 150 mm NaCl stress compared to water‐pretreated seeds under salinity stress. There are two apparent mechanisms by which melatonin alleviated salinity‐induced inhibition of seed germination. Exogenous melatonin decreased oxidative damage induced by NaCl stress by enhancing gene expression of antioxidants. Under NaCl stress, compared to untreated control, the activities of antioxidant enzymes including superoxide dismutase (SOD), catalase (CAT), and peroxidase (POD) were significantly increased by approximately 1.3–5.0‐fold, with a concomitant 1.4–2.0‐fold increase of CsCu‐ZnSOD, CsFe‐ZnSOD, CsCAT, and CsPOD in melatonin‐pretreated seeds. Melatonin also alleviated salinity stress by affecting abscisic acid (ABA) and gibberellin acid (GA) biosynthesis and catabolism during seed germination. Compared to NaCl treatment, melatonin significantly up‐regulated ABA catabolism genes (e.g., CsCYP707A1 and CsCYP707A2, 3.5 and 105‐fold higher than NaCl treatment at 16 hr, respectively) and down‐regulated ABA biosynthesis genes (e.g., CsNECD2, 0.29‐fold of CK2 at 16 hr), resulting in a rapid decrease of ABA content during the early stage of germination. At the same time, melatonin positively up‐regulated GA biosynthesis genes (e.g., GA20ox and GA3ox, 2.3 and 3.9‐fold higher than NaCl treatment at 0 and 12 hr, respectively), contributing to a significant increase of GA (especially GA4) content. In this study, we provide new evidence suggesting that melatonin alleviates the inhibitory effects of NaCl stress on germination mainly by regulating the biosynthesis and catabolism of ABA and GA4.
Seed germination is a critical and complex process in the plant life cycle. Although previous studies have found that melatonin can promote seed germination under salt stress, the involvement of ...melatonin in the regulation of proteomic changes remains poorly understood. In this study, a total of 157 proteins were significantly influenced (ratio ≥ 2 or ≤ -2) by melatonin during seed germination under salt stress using a label-free quantitative technique. Our GO analysis revealed that several pathways were obviously regulated by melatonin, including ribosome biosynthesis, lipid metabolism, carbohydrate metabolism, and storage protein degradation. Not only stress-tolerant proteins but also proteins that produce ATP as part of glycolysis, the citric acid cycle, and the glyoxylate cycle were upregulated by melatonin. Overall, this study provides new evidence that melatonin alleviates the inhibitory effects of NaCl stress on seed germination by promoting energy production. This study is the first to provide insights at the proteomic level into the molecular mechanism of melatonin in response to salt stress in cucumber seeds. This may be helpful to further understand the role of melatonin in cucumber seed germination under stress conditions.
Alkali metal‐oxygen (Li‐O2, Na‐O2) batteries have attracted a great deal of attention recently due to their high theoretical energy densities, comparable to gasoline, making them attractive ...candidates for application in electrical vehicles. However, the limited cycling life and low energy efficiency (high charging overpotential) of these cells hinder their commercialization. The Li‐O2 battery system has been extensively studied in this regard during the past decade. Compared to the numerous reports of Li‐O2 batteries, the research on Na‐O2 batteries is still in its infancy. Although, Na‐O2 batteries show a number of attractive properties such as low charging overpotential and high round‐trip energy efficiency, their cycling life is currently limited to a few tens of cycles. Therefore, understanding the chemistry behind Na‐O2 cells is critical towards enhancing their performance and advancing their development. Chemical and electrochemical reactions of Na‐O2 batteries are reviewed and compared with those of Li‐O2 batteries in the present review, as well as recent works on the chemical composition and morphology of the discharge products in these batteries. Furthermore, the determining kinetics factors for controlling the chemical composition of the discharge products in Na‐O2 cells are discussed and the potential research directions toward improving Na‐O2 cells are proposed.
Various aspects of the Na‐O2 cell, from fundamental (electro)chemistry of sodium and oxygen, to the chemical and electrochemical reaction mechanisms of the cell are discussed. Specifically, effects of various factors, e.g. physicochemical and kinetic parameters, humidity, air electrode, binders, electrolyte, and electrocatalysis on the performance of Na‐O2 cell are reviewed over the recent studies and future research perspectives are accordingly proposed.
Brachytherapy has been indicated as an alternative option for treating cystic craniopharyngiomas (CPs). The potential benefits of brachytherapy for CPs have not yet been clarified. The purpose of ...this work was to conduct a meta-analysis to analyze the long-term efficacy and adverse reactions profile of brachytherapy for CPs.
The relevant databases were searched to collect the clinical trials on brachytherapy in patients with CPs. Included studies were limited to publications in full manuscript form with at least 5-year median follow-up, and adequate reporting of treatment outcomes and adverse reactions data. Stata 12.0 was used for data analysis.
According to the inclusion and exclusion criteria, a total of 6 clinical trials involving 266 patients with CPs were included in this meta-analysis. The minimum average follow-up was 5 years. The results of the meta-analysis showed that 1-year, 2-3 years and 5 years progression free survival rates (PFS) are 75% (95%CI: 66-84%), 62% (95%CI: 52-72%) and 57% (95%CI: 22-92%), respectively. At the last follow-up, less than 16% of patients with visual outcomes worser than baseline in all included studies. While, for endocrine outcomes, less than 32% of patients worser than baseline level.
In general, based on the above results, brachytherapy should be considered as a good choice for the treatment of CP.
It has been proven that the future of energy demands for human society is related to clean energy sources such as solar energy. On the other hand, fuel cell technology converts the chemical energy of ...a fuel into electrical energy. Meanwhile, the polygeneration system based on (semi) renewable energy can be a viable alternative to conventional fuel-based systems. However, examining their performance for widespread implementation requires further and powerful studies. The aim of the present work is to evaluate the performance of the polygeneration energy system to produce electricity, heat, hydrogen and cool. The novel hybrid power system consists of the 10 kWel phosphoric acid fuel cell, linear Fresnel solar reflector (LFR), Organic Rankine Cycle (ORC) and Stirling engine (SE). In the novel energy conversion process proposed, the fuel cell generates electricity and heat, and its waste heat is used to generate additional electricity in the SE. The fuel and oxidant required by the fuel cell are supplied by an electrolyzer that is powered by an ORC system. A solar thermal collector provides the duty required by the evaporator of ORC system. The effect of key parameters such as current density, solar radiation and flow rate of hydrogen on the system energy and exergy performance is also investigated. To evaluate the performance of the LFR system the climatic conditions of Tehran (in Iran) and Beijing (in China) are considered. Results revealed that, the SE and ORC system separately generates 1.48 and 26.54 kW of electricity, respectively. Furthermore, the electrolyzer consumes 23.36 kW of electric power and 3.64 kW of cooling is produced by the chiller. In addition, the energy efficiency and total exergy destruction of the proposed system are 71.32 % and 57.94 kW, respectively.
To use liquid chromatography-mass spectrometry (LC-MS) to identify endogenous differential metabolites in the urine of rats with chronic atrophic gastritis (CAG).
Methylnitronitrosoguanidine (MNNG) ...was used to produce a CAG model in Wistar rats, and HE staining was used to determine the pathological model. LC-MS was used to detect the differential metabolic profiles in rat urine. Diversified analysis was performed by the statistical method.
Compared with the control group, the model group had 68 differential metabolites, 25 that were upregulated and 43 that were downregulated. The main metabolic pathways were D-glutamine and D-glutamic acid metabolism, histidine metabolism and purine metabolism.
By searching for differential metabolites and metabolic pathways in the urine of CAG rats, this study provides effective experimental data for the pathogenesis and clinical diagnosis of CAG.
Metallic Na anode is considered as a promising alternative candidate for Na ion batteries (NIBs) and Na metal batteries (NMBs) due to its high specific capacity, and low potential. However, the ...unstable solid electrolyte interphase layer caused by serious corrosion and reaction in electrolyte will lead to big challenges, including dendrite growth, low Coulombic efficiency and even safety issues. In this paper, we first demonstrate the inorganic–organic coating via advanced molecular layer deposition (alucone) as a protective layer for metallic Na anode. By protecting Na anode with controllable alucone layer, the dendrites and mossy Na formation have been effectively suppressed and the lifetime has been significantly improved. Moreover, the molecular layer deposition alucone coating shows better performances than the atomic layer deposition Al2O3 coating. The novel design of molecular layer deposition protected Na metal anode may bring in new opportunities to the realization of the next-generation high energy-density NIBs and NMBs.
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