| 1. |
- 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.
|
|
| 2. |
- An, T., et al.
(författare)
-
Analysis on microstructure and friction wear performance of chromium carbide/Ni 3Al composite surfacing layer
- 2012
-
Ingår i: Hanjie Xuebao/Transactions of the China Welding Institution. - 0253-360X. ; 33:2, s. 101-104
-
Tidskriftsartikel (refereegranskat)abstract
- Microstructure of chromium carbide reinforced Ni 3Al-based matrix composite coating prepared by argon tungsten-arc welding was investigated with optical microscope, scanning electron microscopy (SEM), electron probe micro-analysis (EPMA) and X-ray diffraction (XRD). The wear performance of the coating and cast iron of piston ring were tested by a Pin-on-Disc tribometer. The results indicated that the Ni 3Al-based matrix was formed during welding, a large number of fine carbide particles such as Cr 3C 2 and Cr 7C 3 dispersed in it; The particle of Cr 3C 2 in welding wire was dissolved and re-precipitated during hardfacing. The re-precipitation of chromium carbide particle contains Fe, Ni elements and forms strong metallurgically bond with Ni 3Al-based matrix. Diffuse distribution of chromium carbide particles and Cr solid-solution in Ni 3Al-based matrix, makes the surfacing layer with higher hardness. The hardfaceing layer shows excellent dry friction wear resistance and its friction coefficient is 0.23, lower than 0.39 which is the friction coefficient of piston material of vermicular graphite cast iron. The wear rate of hardfaceing layer is only 43 percent of vermicular graphite cast iron.
|
|
| 3. |
- Davidson, Marta B., et al.
(författare)
-
Endogenous DNA replication stress results in expansion of dNTP pools and a mutator phenotype
- 2012
-
Ingår i: EMBO Journal. - : European Molecular Biology Organization. - 0261-4189 .- 1460-2075. ; 31:4, s. 895-907
-
Tidskriftsartikel (refereegranskat)abstract
- The integrity of the genome depends on diverse pathways that regulate DNA metabolism. Defects in these pathways result in genome instability, a hallmark of cancer. Deletion of ELG1 in budding yeast, when combined with hypomorphic alleles of PCNA results in spontaneous DNA damage during S phase that elicits upregulation of ribonucleotide reductase (RNR) activity. Increased RNR activity leads to a dramatic expansion of deoxyribonucleotide (dNTP) pools in G1 that allows cells to synthesize significant fractions of the genome in the presence of hydroxyurea in the subsequent S phase. Consistent with the recognized correlation between dNTP levels and spontaneous mutation, compromising ELG1 and PCNA results in a significant increase in mutation rates. Deletion of distinct genome stability genes RAD54, RAD55, and TSA1 also results in increased dNTP levels and mutagenesis, suggesting that this is a general phenomenon. Together, our data point to a vicious circle in which mutations in gatekeeper genes give rise to genomic instability during S phase, inducing expansion of the dNTP pool, which in turn results in high levels of spontaneous mutagenesis. The EMBO Journal (2012) 31, 895-907. doi: 10.1038/emboj.2011.485; Published online 10 January 2012
|
|
| 4. |
- Duan, Sai, et al.
(författare)
-
Density functional theory study on the adsorption and decomposition of the formic acid catalyzed by highly active mushroom-like Au@Pd@Pt tri-metallic nanoparticles
- 2013
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 15:13, s. 4625-4633
-
Tidskriftsartikel (refereegranskat)abstract
- Local structures and adsorption energies of a formic acid molecule and its decomposed intermediates (H, O, OH, CO, HCOO, and COOH) on highly electrocatalytically active mushroom-like Au-core@Pd-shell@Pt-cluster nanoparticles with two atomic layers of the Pd shell and stoichiometric Pt coverage of around half-monolayer (Au@2 ML Pd@0.5 ML Pt) have been investigated by first principles calculations. The adsorption sites at the center (far away from the Pt cluster) and the edge (close to the Pt cluster) are considered and compared. Significant repulsive interaction between the edge sites and CO is observed. The calculated potential energy surfaces demonstrate that, with respect to the center sites, the CO2 pathway is considerably promoted in the edge area. Our results reveal that the unique edge structure of the Pt cluster is responsible for the experimentally observed high electrocatalytic activity of the Au@Pd@Pt nanoparticles toward formic acid oxidation. Such microscopic understanding should be useful for the design of new electrochemical catalysts.
|
|
| 5. |
- Gong, Karin Anne Xia, 1965, et al.
(författare)
-
Wear Evaluation on Ni3Al/MnS Composite Related to Metallurgical Processes
- 2012
-
Ingår i: Journal of Iron and Steel Research International. - 1006-706X. ; 19:7, s. 46-54
-
Tidskriftsartikel (refereegranskat)abstract
- Iron alloyed Ni3Al with composition of Ni-18. 8A1-10. 7Fe0. 5Mn-0. 5Ti-0.2B in atom percent (NAC alloy)showed attractive tribological properties under unlubrication condition at room temperature. The alloy was preparedby hot isostatic pressing (HIP) process. The wear properties were associated with its intrinsic deformation mechanism.Unfortunately, the single phase NAC-alloy worked inadequately with its counterpart disk, and also showed apoor machinability. In the present work, NAC-alloy matrix composite with 6% (volume percent) MnS (manganese sulfide)particle addition was studied to improve its wear behaviors and performance on machining. Two metallurgical processes of HIP and vacuum casting were applied to produce the testing materials. Pin-on-disk (POD) measurements were carried outat room temperature. A commercial vermicular graphite cast iron was selected as a reference material. The counterpartdisk was made of a grey cast iron as liner material in ship engines. The contact pressures of 2. 83 MPa and 5. 66 MPawere normally applied in the tests. The investigation indicated that MnS particle addition in the NAC-alloy compositesfunctions as an effective solid lubricant, and improved wear properties and machinability of the materials. Obviously,as-cast NAC-alloy with in-situ formed MnS phase was working more effectively with the counterpart, comparingto the HIPed NAC-alloy composite with MnS particles. At the high contact pressure of 5.66 MPa, the specificwear rate of the as-cast NAC-alloy composite was high. The phenomenon of the negative effect is mostly due to thebrittle second NiAl phase as evidenced in the microstructure analysis.
|
|
| 6. |
- Tian, Shan Xi, et al.
(författare)
-
Coherent interference in the resonant dissociative electron attachment to carbon monoxide
- 2013
-
Ingår i: Physical Review A. Atomic, Molecular, and Optical Physics. - 1050-2947 .- 1094-1622. ; 88:1, s. 012708-
-
Tidskriftsartikel (refereegranskat)abstract
- Dissociative electron attachment to carbon monoxide, e(-) + CO -> C + O-, at 9.5, 10.0, and 10.6 eV is investigated by using the anion velocity time-sliced map imaging technique. The completely backward scattering distributions of the fast O- fragment are observed at 10.0 and 10.6 eV. The single electron-molecule resonance model fails in interpretation to these unusual angular distributions, while a quantum interference model including two (at 10.0 eV) or three (at 10.6 eV) dissociative outgoing waves is consequently proposed and provides the satisfying results about the experimental data fittings. Moreover, coherent interference among the (2)Pi, (2)Delta, and (2)Phi resonant states of CO- at 10.6 eV could be further established, based on the fact that the sum of the phase-shift fitting values equals pi rad.
|
|
| 7. |
- Wang, Zhaoming, et al.
(författare)
-
Imputation and subset-based association analysis across different cancer types identifies multiple independent risk loci in the TERT-CLPTM1L region on chromosome 5p15.33
- 2014
-
Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:24, s. 6616-6633
-
Tidskriftsartikel (refereegranskat)abstract
- Genome-wide association studies (GWAS) have mapped risk alleles for at least 10 distinct cancers to a small region of 63 000 bp on chromosome 5p15.33. This region harbors the TERT and CLPTM1L genes; the former encodes the catalytic subunit of telomerase reverse transcriptase and the latter may play a role in apoptosis. To investigate further the genetic architecture of common susceptibility alleles in this region, we conducted an agnostic subset-based meta-analysis (association analysis based on subsets) across six distinct cancers in 34 248 cases and 45 036 controls. Based on sequential conditional analysis, we identified as many as six independent risk loci marked by common single-nucleotide polymorphisms: five in the TERT gene (Region 1: rs7726159, P = 2.10 × 10(-39); Region 3: rs2853677, P = 3.30 × 10(-36) and PConditional = 2.36 × 10(-8); Region 4: rs2736098, P = 3.87 × 10(-12) and PConditional = 5.19 × 10(-6), Region 5: rs13172201, P = 0.041 and PConditional = 2.04 × 10(-6); and Region 6: rs10069690, P = 7.49 × 10(-15) and PConditional = 5.35 × 10(-7)) and one in the neighboring CLPTM1L gene (Region 2: rs451360; P = 1.90 × 10(-18) and PConditional = 7.06 × 10(-16)). Between three and five cancers mapped to each independent locus with both risk-enhancing and protective effects. Allele-specific effects on DNA methylation were seen for a subset of risk loci, indicating that methylation and subsequent effects on gene expression may contribute to the biology of risk variants on 5p15.33. Our results provide strong support for extensive pleiotropy across this region of 5p15.33, to an extent not previously observed in other cancer susceptibility loci.
|
|
| 8. |
- Xia, Junjie, et al.
(författare)
-
Suppressing memory T cell activation induces islet allograft tolerance in alloantigen-primed mice
- 2010
-
Ingår i: Transplant International. - : Frontiers Media SA. - 1432-2277 .- 0934-0874. ; 23:11, s. 1154-1163
-
Tidskriftsartikel (refereegranskat)abstract
- P>Memory T cells are known to play a key role in prevention of allograft tolerance in alloantigen-primed mice. Here, we used an adoptively transferred memory T cell model and an alloantigen-primed model to evaluate the abilities of different combinations of monoclonal antibodies (mAb) to block key signaling pathways involved in activation of effector and memory T cells. In the adoptively transferred model, the use of anti-CD134L mAb effectively prevented activation of CD4+ memory T cells and significantly prolonged islet survival, similar to the action of anti-CD122 mAb to CD8+ memory T cells. In the alloantigen-primed model, use of anti-CD134L and anti-CD122 mAbs in addition to co-stimulatory blockade with anti-CD154 and anti-LFA-1 prolonged secondary allograft survival and significantly reduced the proportion of memory T cells; meanwhile, this combination therapy increased the proportion of regulatory T cells (Tregs) in the spleen, inhibited lymphocyte infiltration in the graft, and suppressed alloresponse of recipient splenic T cells. However, we also detected high levels of alloantibodies in the serum which caused high levels of damage to the allogeneic spleen cells. Our results suggest that combination of four mAbs can significantly suppress the function of memory T cells and prolong allograft survival in alloantigen primed animals.
|
|
| 9. |
- Xiao, Fang, et al.
(författare)
-
Slc26a3 deficiency is associated with loss of colonic HCO3 (-) secretion, absence of a firm mucus layer, and barrier impairment in mice.
- 2014
-
Ingår i: Acta physiologica (Oxford, England). - : Wiley. - 1748-1716 .- 1748-1708. ; 211:1, s. 161-175
-
Tidskriftsartikel (refereegranskat)abstract
- DRA (downregulated in adenoma, Slc26a3) is a member of the SLC26 family of anion transporters, which is mutated in congenital chloride diarrhoea (CLD). Besides Cl(-) -rich diarrhoea, CLD patients also have a higher than average incidence of intestinal inflammation. In a search for potential explanations for this clinical finding, we investigated colonic electrolyte transport, the mucus layer, and susceptibility against dextran sodium sulphate (DSS)-induced colitis in Slc26a3(-/-) mice.
|
|
| 10. |
- Yang, Jia-Xiang, et al.
(författare)
-
Facile synthesis, optical properties and theoretical calculation of two novel two-photon absorption chromophores
- 2010
-
Ingår i: Journal of Luminescence. - : Elsevier BV. - 0022-2313 .- 1872-7883. ; 130:4, s. 654-659
-
Tidskriftsartikel (refereegranskat)abstract
- Two heterocycle-based derivatives that can be used as two-photon absorption chromophore, 9-butyl-3-(2,6-diphenylpyridin-4-yl)-9H-carbazole (BDPYC) and 9-butyl-3-(4-(2, 6-diphenylpyridin-4-yl)styryl)-9H-carbazole (BDPSC) have been successfully synthesized and fully characterized by elemental analysis, IR, H-1 NMR, C-13 NMR and MS. The molecules possess D-pi-A structures, but have different pi bridge. The 9-butylcarbazole is used as a donor (D), and the pyridine ring is used as an acceptor (A). One- and two-photon absorption and excited fluorescence properties in various solvents were experimentally investigated. Two-photon initiated optical data recording experiments have been carried Out under 740 nm laser radiation, and the possible mechanism of optical data storage is discussed based on theoretical calculations.
|
|
