| 1. |
- 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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| 2. |
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| 3. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 4. |
- Eriksson, Johan, et al.
(författare)
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Utilisation of oily mill scale sludge as scrap resource
- 1999
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Ingår i: REWAS '99. ; , s. 1423-1430
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Konferensbidrag (refereegranskat)abstract
- This paper presents the results of reduction trials of oily mill scale sludge. Laboratory experiments and two campaigns in a pilot plant rotary kiln have been carried out. The results indicate that it's possible to reduce oily mill scale sludge to sponge iron in the rotary kiln. The first pilot plant campaign was carried out with a mix of 75 wt-% mill scales and 25 wt-% mill scale sludge. During the second campaign 100 wt-% oily mill scale sludge were mixed with blast furnace flue dust and reduced. Petroleum coke has been used as the main reductant in both campaigns. Smelting trials of the sponge iron product have also been carried out in a production EAF. The sponge iron was charged into the scrap bin in big-bags. These trials showed that the degree of metallization of the sponge iron must be higher than 55% to avoid an increased iron oxide content in the slag, i.e. a low iron yield to the metal
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| 5. |
- Ma, Ping, et al.
(författare)
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Experimental and theoretical study of the removal of sulphur and fluorine from pickling hydroxide sludge generated in the stainless steel industry
- 2005
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Ingår i: Global Symposium on Recycling, Waste Treatment, and Clean Technology (REWAS '04). - : Minerals, Metals & Materials Society. - 8495520060 ; , s. 2017-2026
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Konferensbidrag (refereegranskat)abstract
- Pickling hydroxide sludge (pickling sludge for short) generated in the stainless steel industry in Sweden is currently dumped in special landfill areas. After filtration the sludge contains 50-60 wt-% moisture. After drying at 120C it contains about 26 wt-% of metal oxides, such as Fe 2O3, NiO and Cr2O3 and 43 wt-% of CaF2. In order to facilitate the recycling of pickling sludge and/or to recover fluorine as an HF acid, different scale experimental studies to remove sulphur and/or fluorine directly from the sludge have been carried out. Theoretical thermodynamic calculation results show that the simultaneous removal of both sulphur and fluorine is possible when the temperature is above 1500°C under the oxidizing condition and in the presence of water vapour in the system. Experimental results show that the elimination degrees of sulphur and fluorine for pickling sludge can reach 99 wt-% and 84 wt-%, respectively. These results demonstrate that potentially feasible methods for removing sulphur and/or fluorine from the sludge have been found.
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| 6. |
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| 7. |
- Ping, Ma, et al.
(författare)
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Experimental studies on solid-state reduction of pickling sludge generated in the stainless steel production
- 2005
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Ingår i: Scandinavian journal of metallurgy. - : Blackwell Publishing. - 0371-0459 .- 1600-0692. ; 34:1, s. 31-40
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Tidskriftsartikel (refereegranskat)abstract
- Neutralized pickling sludge generated during stainless steel production contains large amounts of calcium fluoride, water and a relatively low metal content, which makes it difficult to directly recycle back to the steelmaking process. It would also pose a potential environmental problem if deposited outdoors over a long term. However, metals such as iron, nickel and chromium, in the form of oxides and/or hydroxides, as well as calcium fluoride in the sludge, are of economic concern to stainless steel makers. Therefore, to develop an economically and technically suitable recycling process, a comparison study on reducing both pickling sludge and mixtures of metal oxides, using petroleum coke (P-coke) and graphite as reductant, respectively, was carried out at temperatures up to 1400°C using thermogravimetric (TG) analysis. Meanwhile, laboratory-scale tests on reducing pickling sludge, using P-coke as reductant, were also conducted in a Tammann fur nace at 800-1200°C. Results of the comparison study by TG demonstrate that the reduction behaviour of pickling sludge may be approached by the reduction behaviour of the metal oxide mixture having the same composition as those in the pickling sludge. Results of the Tammann furnace tests show that temperature has a significant influence on reduction. The reduced metals in the reduction products exist mostly in the form of alloys such as '(Fe,Ni)' and 'Cr-Fe-Ni'.
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| 8. |
- Ping, Ma, et al.
(författare)
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Mechanism study on solid-state reduction in the Fe2O3–NiO–Cr2O3–C system using thermal analyses
- 2005
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Ingår i: Scandinavian journal of metallurgy. - : Blackwell Publishing. - 0371-0459 .- 1600-0692. ; 34:1, s. 22-30
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Tidskriftsartikel (refereegranskat)abstract
- In order to clarify the interactions among metal oxides during reduction of pickling sludge, the reduction mechanism of the metal oxide mixture, Fe2O3-NiO-Cr2O3, which simulates the composition of these metal oxides in pickling sludge, was studied using graphite as a reductant, by means of thermal analysis techniques. X-ray diffraction analysis was used for characterization of reduction products. In addition to the reduction test on the metal oxide mixture mentioned above, for comparison, separate tests on the reduction of Fe2O3, NiO and Cr2O3 were also conducted. The results demonstrate that through formation of a transitional compound 'FeCr2O4', Fe2O3 promotes the complete reduction of Cr 2O3 at a temperature lower than that required for reducing pure Cr2O3. On the other hand, Cr2O3 hinders the reduction of Fe2O3 at lower temperatures. The whole reduction process may be classified as five distinguishable reduction stages in which possible reactions were proposed to represent the reduction mechanism. The reduced metals in the final product exist primarily in the form of solid solutions, such as 'Cr-Fe-Ni', which mainly containing '(Fe,Ni)' and '(Fe,Cr)', and small amounts of carbides, such as (Cr,Fe)7C3 and/or Cr7C3.
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| 9. |
- Shi, Zhi Sheng, et al.
(författare)
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Enrichment of Ni–Mo–V via pyrometallurgical reduction from spent hydrogenation catalysts and the multi-reaction mechanism
- 2023
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Ingår i: Rare Metals. - 1001-0521 .- 1867-7185. ; 42:8, s. 2700-2712
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Tidskriftsartikel (refereegranskat)abstract
- Spent hydrogenation catalysts are important secondary resources due to richness in the valuable metals of Ni, Mo and V. Recovery of valuable metals from spent catalysts has high economic value and environmental benefits since they are hazardous wastes as well. Traditional recycling processes including hydrometallurgical leaching and soda roasting-leaching have disadvantages such as generating large amounts of wastewater, long process, and low recovery efficiency of valuable metals. Thus, this paper proposed synergistic enrichment of Ni, Mo and V via pyrometallurgical reduction at 1400–1500 °C. The melting temperature and viscosity of slag were reduced through slag designing by software FactSage 7.1. The phase diagram of Al2O3-CaO-SiO2-Na2O-B2O3 was drawn, and low-temperature region (≤ 1300 °C) was selected as target slag composition. Ni, Mo, and V can be collaborative captured and recovered through the mutual solubility at molten state. Increasing the melting temperature and the amount of CaO, Na2O and C were conducive to improving the metals recovery rates. The kilogram-scale experiments were carried out, and the recovery efficiencies of Ni, Mo and V were 98.3%, 95.3% and 97.9% under optimized conditions: at 1500 °C, with the basicity of 1.0, 13.1 wt% SiO2, 7.0 wt% B2O3, 7.7 wt% Na2O and 20.0 wt% C. The distribution behavior of valuable metals was clarified by investigating the melting process of slag and the reduction in valuable metals. Ni was preferentially reduced and acted as a capturing agent, which captured other metals to form NiMoV alloys. Graphical abstract: [Figure not available: see fulltext.]
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| 10. |
- Sun, Yu-Ping, et al.
(författare)
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Suppression of resonant auger effect with chirped x-ray free-electron laser pulse
- 2018
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Ingår i: Journal of Physics B. - : IOP PUBLISHING LTD. - 0953-4075 .- 1361-6455. ; 51:3
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Tidskriftsartikel (refereegranskat)abstract
- We study the Auger effect in the presence of strong x-ray free-electron lasers (XFELs) propagating through resonant argon vapors by solving the Maxwell-Bloch equations numerically. The simulations are based on the three-level system with the carrier frequency tuned in the 2p(3/2)-4s resonance. It is shown that the Auger branching is sensitive to the pulse area and duration. The relative Auger yield can be suppressed in the course of pulse propagation due to the interplay between the Auger decay and stimulated emission. Further suppression can be achieved by chirping the initial pulse, which is more effective for the long-pulse case. In addition, the sign and magnitude of the chirp rate play important roles in pulse reshaping and Auger emission.
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