| 1. |
|
|
| 2. |
- Klionsky, Daniel J., et al.
(författare)
-
Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
-
Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
-
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.
|
|
| 3. |
- Zhang, Peili, et al.
(författare)
-
Gas-templating of hierarchically structured Ni-Co-P for efficient electrocatalytic hydrogen evolution
- 2017
-
Ingår i: Journal of Materials Chemistry A. - : ROYAL SOC CHEMISTRY. - 2050-7488 .- 2050-7496. ; 5:16, s. 7564-7570
-
Tidskriftsartikel (refereegranskat)abstract
- One of the grand challenges for developing scalable and sustainable hydrogen producing systems is the lack of efficient and robust earth-abundant element based catalysts for the hydrogen evolution reaction (HER). Herein, a hierarchically structured Ni-Co-P film was fabricated via a gas templating electro-deposition method. This film exhibits remarkably high catalytic performance for the HER in 1 M KOH with respective current densities of -10 and -500 mA cm(-2) at the overpotentials of -30 and -185 mV with a Tafel slope of 41 mV dec(-1). A controlled potential electrolysis experiment demonstrates that the as-prepared Ni-Co-P film is an efficient and robust catalyst with a faradaic efficiency close to 100%. Systematic characterization suggests that the unique hierarchical structure and the mutual participation of nano-sized Ni/Co based components are responsible for the high HER catalytic activity.
|
|
| 4. |
- Cheng, Minglun, et al.
(författare)
-
Photocatalytic H-2 production using a hybrid assembly of an [FeFe]-hydrogenase model and CdSe quantum dot linked through a thiolato-functionalized cyclodextrin
- 2017
-
Ingår i: Faraday discussions. - : Royal Society of Chemistry. - 1359-6640 .- 1364-5498. ; 198, s. 197-209
-
Tidskriftsartikel (refereegranskat)abstract
- It is a great challenge to develop iron-based highly-efficient and durable catalytic systems for the hydrogen evolution reaction (HER) by understanding and learning from [FeFe]-hydrogenases. Here we report photocatalytic H-2 production by a hybrid assembly of a sulfonate-functionalized [FeFe]-hydrogenase mimic (1) and CdSe quantum dot (QD), which is denoted as 1/beta-CD-6-S-CdSe (beta-CD-6-SH = 6-mercapto-beta-cyclodextrin). In this assembly, thiolato-functionalized beta-CD acts not only as a stabilizing reagent of CdSe QDs but also as a host compound for the diiron catalyst, so as to confine CdSe QDs to the space near the site of diiron catalyst. In addition, another two reference systems comprising MAA-CdSe QDs (HMAA = mercaptoacetic acid) and 1 in the presence and absence of beta-CD, denoted as 1/beta-CD/MAA-CdSe and 1/MAA-CdSe, were studied for photocatalytic H-2 evolution. The influences of beta-CD and the stabilizing reagent beta-CD-6-S- on the stability of diiron catalyst, the fluorescence lifetime of CdSe QDs, the apparent electron transfer rate, and the photocatalytic H-2-evolving efficiency were explored by comparative studies of the three hybrid systems. The 1/beta-CD-6-SCdSe system displayed a faster apparent rate for electron transfer from CdSe QDs to the diiron catalyst compared to that observed for MAA-CdSe-based systems. The total TON for visible-light driven H-2 evolution by the 1/beta-CD-6-S-CdSe QDs in water at pH 4.5 is about 2370, corresponding to a TOF of 150 h(-1) in the initial 10 h of illumination, which is 2.7- and 6.6-fold more than the amount of H-2 produced from the reference systems 1/beta-CD/MAA-CdSe and 1/MAA-CdSe. Additionally, 1/beta-CD-6-S-CdSe gave 2.4-5.1 fold enhancement in the apparent quantum yield and significantly improved the stability of the system for photocatalytic H-2 evolution.
|
|
| 5. |
- Han, Kai, et al.
(författare)
-
Photochemical hydrogen production from water catalyzed by CdTe quantum dots/molecular cobalt catalyst hybrid systems
- 2015
-
Ingår i: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1359-7345 .- 1364-548X. ; 51:32, s. 7008-7011
-
Tidskriftsartikel (refereegranskat)abstract
- A hybrid system with a coordinative interaction between a cobalt complex of a N2S2-tetradentate ligand and CdTe quantum dots displayed a high activity (initial TOF 850 h(-1)) and improved stability (TON 1.44 x 10(4) based on catalyst over 30 h) for the photochemical H-2 generation from water, with a quantum efficiency of 5.32% at 400 nm.
|
|
| 6. |
- Li, Xueqiang, et al.
(författare)
-
Noncovalent assembly of a metalloporphyrin and an iron hydrogenase active-site model : Photo-induced electron transfer and hydrogen generation
- 2008
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207 .- 1089-5647. ; 112:27, s. 8198-8202
-
Tidskriftsartikel (refereegranskat)abstract
- A noncovalent assembly of a pyridyl-functionalized hydrogenase active-site model complex and zinc tetraphenylporphyrin has been obtained and characterized. Upon light irradiation, fluorescence quenching by electron transfer was observed from the singlet excited state of the porphyrin to the diiron center, and the mechanism was verified by fluorescence lifetime and transient absorption spectroscopic measurements. In contrast to molecular dyads linked by covalent bonds, the assembled system was designed to avoid charge recombination via complex dissociation after photo-induced electron transfer. Visible light-driven hydrogen generation was observed from this self-assembled system. The assembling strategy employed in this study has the potential to be used for any other hydrogenase models in the future.
|
|
| 7. |
- Meng, Peng, et al.
(författare)
-
CdSe quantum dots/molecular cobalt catalyst co-grafted open porous NiO film as a photocathode for visible light driven H-2 evolution from neutral water
- 2015
-
Ingår i: Journal of Materials Chemistry A. - : Royal Society of Chemistry (RSC). - 2050-7488 .- 2050-7496. ; 3:37, s. 18852-18859
-
Tidskriftsartikel (refereegranskat)abstract
- An active noble-metal-free photocathode was fabricated by co-grafting water-soluble thioglycolic acid-stabilized CdSe quantum dots and a molecular cobaloxime catalyst (CoP) through chemical linkage on a p-type open porous NiO film. This photocathode was used as a working electrode in a three-electrode cell, which displayed a photocurrent density up to 110 mu A cm(-2) at an applied potential of 0 V vs. NHE in 0.1 M Na2SO4 solution at pH 6.8 upon visible light illumination. The comparative studies showed that the open porous NiO/CdSe electrode did display a higher photocurrent density than that exhibited by an analogous planar NiO/CdSe electrode made by doctor-blading a NiO paste. Long-time photoelectrolysis experiments revealed that about 83% of the photocurrent density remained after 3.5 h illumination at 0.2 V vs. NHE. The open porous NiO/CdSe/CoP photocathode showed a considerably better current density and photocatalytic stability compared to the so-far reported dye-or QD-sensitized NiO cathodes with a cobaloxime catalyst chemically attached or physically adsorbed on the electrode surface under similar conditions.
|
|
| 8. |
- Na, Yong, et al.
(författare)
-
An approach to water-soluble hydrogenase active site models : Synthesis and electrochemistry of diiron dithiolate complexes with 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo 3.3.1 nonane ligand(s)
- 2006
-
Ingår i: Journal of Organometallic Chemistry. - : Elsevier BV. - 0022-328X .- 1872-8561. ; 691:23, s. 5045-5051
-
Tidskriftsartikel (refereegranskat)abstract
- In order to improve the hydro- and protophilicity of the active site models of the Fe-only hydrogenases, three diiron dithiolate complexes with DAPTA ligand(s) (DAPTA=3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonanc), (mu-pdt)[Fe(CO)(2)][Fe(CO)(2)(DAPTA)] (1, pdt = 1,3-propanedithiolato), (mu-pdt)[Fe(CO)(2)(DAPTA)](2) (2) and (mu-pdt)[Fe(CO)(2)(PTA)][Fe(CO)(2)(DAPTA)] (3), were prepared and spectroscopically characterized. The water solubility of DAPTA-coordinate complexes 1-3 is better than that of the PTA-coordinate analogues. With complexes 1-3 as electrocatalysts, the overvoltage is reduced by 460-770 mV for proton reduction from acetic acid at low concentration in CH3CN. Significant decrease, up to 420 mV, in reduction potential for the Fe(I)Fe(I) to Fe(I)Fe(0) process and the curve-crossing phenomenon are observed in cyclic voltammograms of 2 and 3 in CH3CN/H2O mixtures. The introduction of the DAPTA ligand to the diiron dithiolate model complexes indeed makes the water solubility of 2 and 3 sufficient for electrochemical studies in pure water, which show that the proton reduction from acetic acid in pure water is electrochemically catalyzed by 2 and 3 at ca. -1.3 V vs. NHE.
|
|
| 9. |
- Na, Yong, et al.
(författare)
-
Visible light-driven electron transfer and hydrogen generation catalyzed by bioinspired 2Fe2S complexes
- 2008
-
Ingår i: Inorganic Chemistry. - : American Chemical Society (ACS). - 0020-1669 .- 1520-510X. ; 47:7, s. 2805-2810
-
Tidskriftsartikel (refereegranskat)abstract
- Complexes [{(mu-SCH2)(2)NCH2C6H5){Fe(CO)(2)L-1){Fe(CO)(2)L-2}] (L-1 = CO, L-2 = P(Pyr)(3), 2; L-1 = L-2 = P(Pyr)(3), 3) were prepared, which have the lowest reduction potentials for the mono- and double-CO-displaced diiron complexes reported so far. Hydrogen evolution, driven by visible light, was successfully observed for a three-component system, consisting of a ruthenium polypyridine complex, the biomimetic model complex 2 or 3, and ascorbic acid as both electron and proton donor in CH3CN/H2O. The electron transfer from photogenerated Ru(bPY)(3)(+) to 2 or 3 was detected by laser flash photolysis. Under optimal conditions, the total turnover number for hydrogen evolution was 4.3 based on 2 and 86 based on Ru(bPY)(3)(2+) in a three-hour photolysis.
|
|
| 10. |
- Yang, Yong, et al.
(författare)
-
Evident Enhancement of Photoelectrochemical Hydrogen Production by Electroless Deposition of M-B (M = Ni, Co) Catalysts on Silicon Nanowire Arrays
- 2016
-
Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society. - 1944-8244 .- 1944-8252. ; 8:44, s. 30143-30151
-
Tidskriftsartikel (refereegranskat)abstract
- Modification of p-type Si surface by active and stable earth-abundant electrocatalysts is an effective strategy to improve the sluggish kinetics for the hydrogen evolution reaction (HER) at p-Si/electrolyte interface and to develop highly efficient and low-cost photocathodes for hydrogen production from water. To this end, Si nanowire (Si-NW) array has been loaded-with highly efficient electrocatalysts, M-B (M = Ni, Co), by facile and quick electroless plating to build M-B catalyst-modified Si nanowire-array-textured photocathodes for water reduction to H-2. Compared with the bare Si-NW array, composite Si-NWs/M-B arrays display evidently enhanced photoelectrochemical (PEC) performance. The onset potential (V-phon) of cathodic photocurrent is positively shifted by 530-540 mV to 0.44-0.45 V vs RHE, and the short-circuit current density (J(sc)) is up to 19.5 mA cm(-2) in neutral buffer solution under simulated 1 sun illumination. Impressively, the half-cell photopower conversion efficiencies (eta(hc)) of the optimized Si-NWs/Co-B (2.53%) and Si-NWs/Ni-B (2.45%) are comparable to that of Si-NWs/Pt (2.46%). In terms of the large J(sc), V-phon, and eta(hc) values, as well as the high Faradaic efficiency, Si-NW-s/M-B electrodes are among the top performing Si photocathodes which are modified with HER electrocatalysts but have no buried solid/solid junction.
|
|
