47 research outputs found
Simulation and Analysis of Inhomogeneous Degradation in Large Format LiMn\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e/ Carbon Cells
Degradation phenomena are not distributed uniformly in a large-format cell. To better understand the inhomogeneous degradation in large-format cells, a two-dimensional model was developed for a LiMn2O4 (LMO)/Carbon cell. The model includes both the non-uniform porous electrode properties and the electrode mismatch. The simulation results show that when the anode edge is extended over the cathode edge, the LMO particles near the edge suffer larger potential difference, larger charge/discharge depth, and higher insertion-induced stress. Therefore, the predicted loss of LMO is more pronounced near the edge as has been seen experimentally. The influence of different design adjustable parameters (such as: the anode extension length, the capacity ratio, the porosity, and the electrode thickness) and electrolyte properties (such as: the diffusion coefficient and the ionic conductivity) on the cathode performance. Among them, the over-potential behavior of the cathode is most sensitive to the extent of the electrode mismatch. Larger anode extensions will increase the possibility of the LMO degradation at the cathode edge. This suggests that a longer extension of the anode is not better for improvement of cell life. An optimal design of the anode extension length should be carried out
Genome cloning and genetic diversity of Apple chlorotic leaf spot virus
514-519Apple chlorotic leaf spot virus (ACLSV) with a wide distribution and variability is great threat to apple yield and quality. The systematic research on the occurrence, genetic structure and evolutionary mechanism is important for the prevention of ACLSV. In this study, 360 apple leaf samples were collected from Shanxi province and tested by RT-PCR, and the result showed that the incidence of ACLSV in Shanxi was ranged from 43.59% in Linfen to 68.18% in Wanrong. One new ACLSV isolate (shanxi14-MK368727) was collected from the positive samples, of which the genome (including the 5' and 3' ends) was 7507 bp and encoded 2536 amino acids. Compared with online database, the highest nd identity was between shanxi14 and KJ522693.1, and the lowest was shanxi14 and M58152.1. Phylogenetic analyzed based on genome showed that 25 isolated of ACLSV were divided two groups (Group I and II), which showed that was no significant correlation with geographic location. The selection pressures of POL, MP and CP were tested, the result proved the three genes were under negative selection pressure. The knowledge presented in this study will be useful in for the design of long-term, sustainable management strategies for controlling these viruses
Capacity Fade Model for Spinel LiMn\u3csub\u3e2\u3c/sub\u3eO\u3csub\u3e4\u3c/sub\u3e Electrode
A mathematical model for the capacity fade of a LiMn2O4 (LMO) electrode is developed in this paper by including the acid attack on the active material and the solid electrolyte interphase (SEI) film formation on the LMO particle surface. The acid generated by the LiPF6 and the solvent decompositions are coupled to the manganese (Mn) dissolution. The decrease of the Li ion diffusion coefficient is involved as another contribution to the capacity fade, which is caused by the passive film formation on the active material surface. The effects of cell practical operation/fabrication conditions and kinetics of side reactions on battery life are also investigated by utilizing the developed mathematical model
The Carotid and Middle cerebral artery Occlusion Surgery Study (CMOSS): a study protocol for a randomised controlled trial
The regulation of trefoil factor 2 expression by the transcription factor Sp3
National Natural Science Foundation of China [81101817, 30971362]; China Postdoctoral Science Foundation [20100480724]Trefoil factor family 2 (TFF2) participates in mucus stabilization and repair, apoptosis, and inflammatory responses. Previously published reports have indicated that several growth factors and basal transcription factors are associated with the expression of TFF2. However, the detailed mechanisms that regulate TFF2 expression are not fully understood. The present study was designed to assess the essential role of the transcription factor SP3 with respect to TFF2 expression. We first demonstrated that there was a negative correlation between the expression levels of SP3 and TFF2. Thus, in the examined cells, the overexpression of SP3 decreased the expression level of TFF2, whereas the inhibition of SP3 increased the expression level of TFF2. Moreover, we discovered two GC boxes in the TFF2 promoter and confirmed the specific binding of SP3 to this promoter. On the whole, this study indicated that Sp3 was a major regulator of TFF2 expression. This knowledge should contribute to our understanding of the role that is played by SP3 in the regulation of TFF2 expression. (C) 2012 Elsevier Inc. All rights reserved
Pervasive hybridization during evolutionary radiation of Rhododendron subgenus Hymenanthes in mountains of southwest China
Radiations are especially important for generating species biodiversity in mountainous ecosystems. The contribution of hybridization to such radiations has rarely been examined. Here, we use extensive genomic data to test whether hybridization was involved in evolutionary radiation within Rhododendron subgenus Hymenanthes, whose members show strong geographic isolation in the mountains of southwest China. We sequenced genomes for 143 species of this subgenus and 93 species of four other subgenera, and found that Hymenanthes was monophyletic and radiated during the late Oligocene to middle Miocene. Widespread hybridization events were inferred within and between the identified clades and subclades. This suggests that hybridization occurred both early and late during diversification of subgenus Hymenanthes, although the extent to which hybridization, speciation through mixing-isolation-mixing or hybrid speciation, accelerated the diversification needs further exploration. Cycles of isolation and contact in such and other montane ecosystems may have together promoted species radiation through hybridization between diverging populations and species. Similar radiation processes may apply to other montane floras in this region and elsewhere
Metagenomics-based exploration of key soil microorganisms contributing to continuously planted Casuarina equisetifolia growth inhibition and their interactions with soil nutrient transformation
Casuarina equisetifolia (C. equisetifolia) is an economically important forest tree species, often cultivated in continuous monoculture as a coastal protection forest. Continuous planting has gradually affected growth and severely restricted the sustainable development of the C. equisetifolia industry. In this study, we analyzed the effects of continuous planting on C. equisetifolia growth and explored the rhizosphere soil microecological mechanism from a metagenomic perspective. The results showed that continuous planting resulted in dwarfing, shorter root length, and reduced C. equisetifolia seedling root system. Metagenomics analysis showed that 10 key characteristic microorganisms, mainly Actinoallomurus, Actinomadura, and Mycobacterium, were responsible for continuously planted C. equisetifolia trees. Quantitative analysis showed that the number of microorganisms in these three genera decreased significantly with the increase of continuous planting. Gene function analysis showed that continuous planting led to the weakening of the environmental information processing-signal transduction ability of soil characteristic microorganisms, and the decrease of C. equisetifolia trees against stress. Reduced capacity for metabolism, genetic information processing-replication and repair resulted in reduced microbial propagation and reduced microbial quantity in the rhizosphere soil of C. equisetifolia trees. Secondly, amino acid metabolism, carbohydrate metabolism, glycan biosynthesis and metabolism, lipid metabolism, metabolism of cofactors and vitamins were all significantly reduced, resulting in a decrease in the ability of the soil to synthesize and metabolize carbon and nitrogen. These reduced capacities further led to reduced soil microbial quantity, microbial carbon and nitrogen, microbial respiration intensity, reduced soil enzyme nutrient cycling and resistance-related enzyme activities, a significant reduction in available nutrient content of rhizosphere soils, a reduction in the ion exchange capacity, and an impediment to C. equisetifolia growth. This study provides an important basis for the management of continuously planted C. equisetifolia plantations
The Carotid and Middle cerebral artery Occlusion Surgery Study (CMOSS): a study protocol for a randomised controlled trial
Rising rural body-mass index is the main driver of the global obesity epidemic in adults
Body-mass index (BMI) has increased steadily in most countries in parallel with a rise in the proportion of the population who live in cities(.)(1,2) This has led to a widely reported view that urbanization is one of the most important drivers of the global rise in obesity(3-6). Here we use 2,009 population-based studies, with measurements of height and weight in more than 112 million adults, to report national, regional and global trends in mean BMI segregated by place of residence (a rural or urban area) from 1985 to 2017. We show that, contrary to the dominant paradigm, more than 55% of the global rise in mean BMI from 1985 to 2017-and more than 80% in some low- and middle-income regions-was due to increases in BMI in rural areas. This large contribution stems from the fact that, with the exception of women in sub-Saharan Africa, BMI is increasing at the same rate or faster in rural areas than in cities in low- and middle-income regions. These trends have in turn resulted in a closing-and in some countries reversal-of the gap in BMI between urban and rural areas in low- and middle-income countries, especially for women. In high-income and industrialized countries, we noted a persistently higher rural BMI, especially for women. There is an urgent need for an integrated approach to rural nutrition that enhances financial and physical access to healthy foods, to avoid replacing the rural undernutrition disadvantage in poor countries with a more general malnutrition disadvantage that entails excessive consumption of low-quality calories.Peer reviewe