| 1. |
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| 2. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 3. |
- Yan, Hua, et al.
(författare)
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Microstructure and mechanical properties of K438 alloy processed by selective laser melting and subsequent heat treatment
- 2022
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Ingår i: Materials Characterization. - : Elsevier BV. - 1044-5803. ; 191
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Tidskriftsartikel (refereegranskat)abstract
- In this work, K438 nickel-based high-temperature alloy was successfully prepared and heat-treated by selected laser melting (SLM). A comparative study of the microstructure and mechanical properties of different samples was carried out to reveal the influence of SLM process parameters and heat treatment. The layer-by-layer fabrication in SLM created a special sunflower-shaped dendrites and the extremely fast cooling rate resulted in a large number of low angle grain boundaries (LAGBs) and inhomogeneous γ’ phases being found in the samples. After heat treatment, the orbital structure within the tissue disappeared and the coarse square γ’ phase (0.4 to 0.8 μm) melted and precipitated fine rounded secondary γ’ phases (0.05 μm). During recrystallisation, the LAGBs to high angle grain boundaries (HAGBs) transition occurs and many fine grain clusters appear at the grain boundaries, resulting in subcrystalline nucleation based on subcrystals and an increase in UTS.
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| 4. |
- Azzi, Elias, et al.
(författare)
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Guidelines for estimation of biochar durability : Background report
- 2023
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Rapport (övrigt vetenskapligt/konstnärligt)abstract
- Biochar is produced by heating biomass in the total or partial absence of oxygen. This report addresses the long-term persistence of biochar in soil and how this can be managed in climate calculations and reporting. The report consists of this summary and four chapters, which can be read independently.Different terms have been used to describe the durability of biochar carbon storage, but also the physical presence of biochar in soils, e.g. persistence, permanence, recalcitrance, residence times, stability. Today, the term “durability of carbon storage” is preferred in policy contexts, but various academic disciplines such as soil science have other established terms like “persistence”. Here, both durability and persistence are used, rather interchangeably. It is important to be aware of differences in meaning that exist between disciplines.The purpose of this report is to present the state of knowledge regarding the proportion of carbon in biochar that remains in the soil over time and provide recommendations for calculating this. There is a need to calculate the persistence of biochar in soil for national climate reporting, corporate climate reporting, carbon credit trading, and life cycle assessments for various purposes.On the persistence of biocharThe amount of biochar remaining after a certain time depends on the properties of the biochar and the environment in which it is located. Nearly all research on biochar persistence has focused on its application in agricultural soils.The main reason for the high durability of biochar carbon storage is the formation of fused aromatic stable structures during biomass pyrolysis. A high degree of fused aromatic structures makes biochar much less prone to microbial decomposition than fresh biomass.Different biochars have different properties, and this influences how long they persist in the soil. To achieve biochar with properties that provide higher persistence, it should be produced at higher temperatures for a sufficient duration.Measuring and calculating biochar persistenceEstablished quantification methods of 100-year biochar persistence (e.g. referenced in IPCC inventory guidelines and used in voluntary carbon markets, to date) extrapolate short-term soil decomposition processes, and do not fully consider the processes that may explain millennial persistence.Calculations regarding biochar persistence have traditionally used a time span of 100 years to describe the amount of remaining carbon after a certain time. The use of specifically 100 years lacks a well founded scientific reason, but has been regarded as “far enough” into the future from a climate perspective and close enough for modelling to be meaningful.An active area of research relevant for the understanding biochar carbon storage durability is the development of advanced analytical characterisation methods of biochar that will enable measurement of the physicochemical heterogeneity in carbon structures present in biochar.Another area of continued research is biochar incubation, with a focus on field conditions, to elucidate both differences from laboratory conditions, and how transport processes affect biochar in the field.Recommendation and conclusionIn the project, available research data has been aggregated into a functional model that calculates how much of the carbon in biochar remains after a given number of years. The model is based on the H/C ratio of the biochar placed in the soil and the annual average temperature at the location.The model is made freely accessible to provide biochar market actors with the best available knowledge for estimating the durability of biochar carbon.Existing research results provide a sufficient foundation for estimation of the amount of biochar expected to remain over time. Future research results are expected to lead to increased knowledge regarding the decomposition properties of biochar, in particular biochars with a very low H/C ratio. Therefore, this recommendation will be revised by the end of the project in 2025.
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| 5. |
- Azzi, Elias, et al.
(författare)
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Modelling biochar long-term carbon storage in soil with harmonized analysis of decomposition data
- 2024
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Ingår i: Geoderma. - 0016-7061 .- 1872-6259. ; 441
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Tidskriftsartikel (refereegranskat)abstract
- The climate change mitigation benefits of biochar systems arise largely from carbon storage in biochar. However, while biochar is increasingly recognized as a carbon dioxide removal technology, there are on-going scientific discussions on how to estimate the persistence of biochar carbon when biochar is used in soils. Estimates vary from decades to millennia, building on different modelling approaches and evidence. Here, we revisited the persistence estimates derived from extrapolation of biochar incubation experiments, with the aims of making incubation data available, modelling choices transparent, and results reproducible. An extensive dataset of biochar incubations, including 129 biochar decomposition time series, was compiled and is made available alongside code for its analysis. Biochar persistence correlations were sensitive to data selection procedures and to the curve fitting modelling step, while soil temperature adjustments methods had less impact. Biochar H/C ratio remained the main predictor of biochar persistence, in line with previous research, regardless of the extrapolation assumptions (multi-pool exponential functions or power function) used in curve fitting. The relation between H/C and percentage of biochar carbon remaining after 100 years (BC100) was better explained by a power model than a linear model, with R2 values between 0.5 and 0.9. Using multi-pool exponential functions, estimated BC100 varied between 90 % and 60 % for H/C from 0 to 0.7. However, using power functions, BC100 was constrained between 90 % and 80 % for the same H/C range. Additional information about the biochar, the pyrolysis conditions or the environmental incubation conditions did not significantly increase explained variance. Notably, the dataset lacks observations at H/C ratios below 0.2, of biochar made from manure and biosolids, biochar from processes other than slow pyrolysis, field studies, and incubation temperatures below 10 °C, which should guide future experimental work. The detailed analysis performed in this study does not cast doubts on the longevity of biochar carbon storage; rather, it confirms previous knowledge by critically examining the modelling, elucidating the assumptions and limitations, and making the analysis fully reproducible. There is a need for further interdisciplinary work on integration of various theories and approaches to biochar persistence, ultimately leading to the formulation of policy-relevant conclusions.
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| 6. |
- Chen, Fang, et al.
(författare)
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A field study of cold effects among cold store workers in China
- 1991
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Ingår i: Arctic Medical Research. - 0782-226X. ; 50:Suppl. 6, s. 99-103
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Tidskriftsartikel (refereegranskat)abstract
- A field study was carried out among cold store workers in China. A self administrative questionnaire and health check-up were taken among 463 male workers from two different types of cold stores, all during their whole daily work. 296 men from Lower Temperature Stores (LTS), where the air temperature was between -10 to -25 degrees C, and 167 men from Ice Stores (IS), where the air temperature was between -5 and +5 degrees C participated. Another group of 152 men working in normal stores and exposed to an air temperature between 20 and 30 degrees C served as a control group. The study did not indicate any special disease attributable to the cold environment. The number of complaints of lower back pain and knee pain in the cold exposed group were significantly higher than that of the control group (in LTS: 42.3%, 46.6%; IS: 52.7%, 50.8%; control group: 9.2%, 14.5%; low back and knee pain, respectively). After 5 years of cold exposure work, the lower back and knee symptoms were very frequent. The point press pain on the knees of the cooler group (LTS) was higher than in the moderate cold group (IS). We suppose that the cold factor contributed to lower back and knee pain. 12.2% of 463 cold exposed workers had frostbite on the body extremities viz: hand, foot and ear. Self estimation of health indicated more problems among cold exposed workers (28.0%) than control group (2.7%).
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| 7. |
- Duan, Jianli, et al.
(författare)
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Bab2 Functions as an Ecdysone-Responsive Transcriptional Repressor during Drosophila Development
- 2020
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Ingår i: Cell Reports. - : Elsevier BV. - 2211-1247. ; 32:4
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Tidskriftsartikel (refereegranskat)abstract
- Drosophila development is governed by distinct ecdysone steroid pulses that initiate spatially and temporally defined gene expression programs. The translation of these signals into tissue-specific responses is crucial for metamorphosis, but the mechanisms that confer specificity to systemic ecdysone pulses are far from understood. Here, we identify Bric-a-brac 2 (Bab2) as an ecdysone-responsive transcriptional repressor that controls temporal gene expression during larval to pupal transition. Bab2 is necessary to terminate Salivary gland secretion (Sgs) gene expression, while premature Bab2 expression blocks Sgs genes and causes precocious salivary gland histolysis. The timely expression of bab2 is controlled by the ecdysone-responsive transcription factor Broad, and manipulation of EcR/USP/Broad signaling induces inappropriate Bab2 expression and termination of Sgs gene expression. Bab2 directly binds to Sgs loci in vitro and represses all Sgs genes in vivo. Our work characterizes Bab2 as a temporal regulator of somatic gene expression in response to systemic ecdysone signaling.
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| 8. |
- Li, Haichao
(författare)
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Advances in understanding bioaerosol release characteristics and potential hazards during aerobic composting
- 2024
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Ingår i: Science of the Total Environment. - 0048-9697 .- 1879-1026. ; 926
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Forskningsöversikt (refereegranskat)abstract
- Bioaerosol emissions and their associated risks are attracting increasing attention. Bioaerosols are generated during the pretreatment, fermentation, and screening of mature compost when processing various types of solid waste at composting plants (e.g., municipal sludge and animal manure). In this review, we summarize research into bioaerosols at different types of composting plants by focusing on the methods used for sampling bioaerosols, stages when emissions potentially occur, major components of bioaerosols, survival and diffusion factors, and possible control strategies. The six -stage Andersen impactor is the main method used for sampling bioaerosols in composting plants. In addition, different composting management methods mainly affect bioaerosol emissions from composting plants. Studies of the components of bioaerosols produced by composting plants mainly focused on bacteria and fungi, whereas few considered others such as endotoxin. The survival and diffusion of bioaerosols are influenced by seasonal effects due to changes in environmental factors, such as temperature and relative humidity. Finally, three potential strategies have been proposed for controlling bioaerosols in composting plants. Improved policies are required for regulating bioaerosol emissions, as well as bioaerosol concentration diffusion models and measures to protect human health.
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| 9. |
- Li, Haichao
(författare)
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Biochar enhanced organic matter transformation during pig manure composting: Roles of the cellulase activity and fungal community
- 2023
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Ingår i: Journal of Environmental Planning and Management. - : Elsevier BV. - 0964-0568 .- 1360-0559. ; 333
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Tidskriftsartikel (refereegranskat)abstract
- Fungal degradation of cellulose is a key step in the conversion of organic matter in composting. This study investigated the effects of adding 10% biochar (including, prepared from corn stalk and rape stalk corresponding to CSB and RSB) on organic matter transformation in composting and determined the role of cellulase and fungal communities in the conversion of organic matter. The results showed that biochar could enhance the conversion of organic matter, especially in RSB treatment. Biochar could increase cellulase activity, and RSB could enhance 33.78% and 30.70% the average activity of cellulase compared with the control and CSB treatments in the mesophilic to thermophilic phase, respectively. The results of high throughput sequencing demonstrated that Basidiomycota dominant in mesophilic phase, and Ascomycota dominant in other phases of composting. The redundancy analysis showed that Alternaria, Thermomycees, Aspergillus, Wallemia, and Melanocarpus might be the key fungi for the degradation of organic matter, and Fusarium, Penicillium, and Scopulariopsis may promote the conversion of organic matter. Network showed that the addition of RSB changed the interactions between fungal communities and organic matter transformation, and RSB treatment enriched members of Ascomycota related to organic matter transformation and cellulase activity. These results indicated that RSB improved organic matter conversion by enhancing the role of cellulase and fungal communities.
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| 10. |
- Li, Haichao
(författare)
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Biochar improves the humification process during pig manure composting: Insights into roles of the bacterial community and metabolic functions
- 2024
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Ingår i: Journal of Environmental Management. - 0301-4797 .- 1095-8630. ; 355
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Tidskriftsartikel (refereegranskat)abstract
- Biochar could promote humification in composting, nevertheless, its mechanism has not been fully explored from the perspective of the overall bacterial community and its metabolism. This study investigated the effects of bamboo charcoal (BC) and wheat straw biochar (WSB) on the humic acid (HA) and fulvic acid (FA) contents during pig manure composting. The results showed that BC enhanced humification more than WSB, and significantly increased the HA content and HA/FA ratio. The bacterial community structure under BC differed from those under the other treatments, and BC increased the abundance of bacteria associated with the transformation of organic matter compared with the other treatments. Furthermore, biochar enhanced the metabolism of carbohydrates and amino acids in the thermophilic and cooling phases, especially BC. Through Mantel tests and network analysis, we found that HA was mainly related to carbon source metabolism and the bacterial community, and BC might change the interaction patterns among carbohydrates, amino acid metabolism, Bacillales, Clostridiales, and Lactobacillales with HA and FA to improve the humification process during composting. These results are important for understanding the mechanisms associated with the effects of biochar on humification during composting.
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