| 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. |
- Teng, Chao, et al.
(författare)
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Influence of Triple Bonds as pi-Spacer Units in Metal-Free Organic Dyes for Dye-Sensitized Solar Cells
- 2010
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:25, s. 11305-11313
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Tidskriftsartikel (refereegranskat)abstract
- Four metal-free organic sensitizers (TC101-TC104) with triple bonds in pi-spacers and five reference dyes (TC, TC105, TPC1, D5, and TH208) without triple bonds were applied in dye-sensitized solar cells to study the influence of triple bonds as pi-spacer units on their photoelectrochemical properties and dye-sensitized solar cells (DSCs) performance. Results show that the introduction of triple bond could red-shift the dye's absorption spectrum due to the enhancement of the pi-spacer. However, the spectrum red-shift is much less than that of the introduction of double bond because of more electronegativity of triple bond. The incident photon-to-current conversion efficiency reveals that the electron transfer yield (Phi(nu)(ET)) of DSCs becomes larger with the introduction of triple bond. Electrochemical impedance spectroscopy analysis reveals that the introduction of triple bond almost does not change the electron lifetimes in TiO2 films but decreases the effective diffusion lengths.
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| 3. |
- Teng, Chao, et al.
(författare)
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Molecular Design of Anthracene-Bridged Metal-Free Organic Dyes for Efficient Dye-Sensitized Solar Cells
- 2010
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Ingår i: The Journal of Physical Chemistry C. - : American Chemical Society (ACS). - 1932-7447 .- 1932-7455. ; 114:19, s. 9101-9110
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Tidskriftsartikel (refereegranskat)abstract
- A series of metal-free organic dyes bridged by anthracene-containing pi-conjugations were designed and synthesized as new chromophores for the application of dye-sensitized solar cells (DSCs). Detailed investigations on the relationship between the dye structures, photophysical properties, electrochemical properties, and performances of DSCs are described. With the introduction of the anthracene moiety, together with a triple bond for the fine-tuning of molecular planar configurations and to broaden absorption spectra, the short-circuit photocurrent densities (J(sc)) and open-circuit photovoltages (V-oc) of DSCs were improved to a large extent. The improvement of J(sc) is attributed to much broader absorption spectra of the dyes with the anthracene moiety. Electrochemical impedance spectroscopy (EIS) analysis reveals that the introduction of the anthracene moiety suppresses the charge recombination arising from electrons in TiO2 films with I-3(-) ions in the electrolyte, thus improving V-oc considerably. On the basis of optimized molecular structures and DSC test conditions, the dye TC501 shows a prominent solar energy conversion efficiency (eta) up to 7.03% (J(sc) = 12.96 mA . cm(-2), V-OC = 720 mV, ff = 0.753) under simulated AM 1.5 irradiation (100 mW . cm(-2)).
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| 4. |
- Huang, Sunan, et al.
(författare)
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An investigation on child occupant safety in passenger vehicles based on accident data from Changsha, China
- 2013
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Ingår i: Proceedings - 2013 5th Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2013. - 9780769549323 ; , s. 218-221
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Konferensbidrag (refereegranskat)abstract
- The objective of this study is to determine the traffic safety situation of child occupants in the urban areas of Changsha, China. For this purpose, accident data were collected from the local traffic police authority. The selected samples have been dated from January 1,2001 to December 31,2010, durich which 1, 629 traffic accidents involving children occurred in Changsha. A total of 331 child occupants up to 15 years of age were identified in these accidents. A statistical analysis was then conducted in terms of the accident type, accident scenario, child age, gender, injury region, and injury severity. The results indicate that the side impact is the most common accident scenario in the child occupant accidents, accounting for 45% of all the cases. The major type of the accidents is the double-vehicle crashes in which passenger vehicles account for 73.4%. No child restraint system (CRS) was identified in the selected accidents. The head and extremity injuries have a high frequency in the child injuries. With the implementation of safey regulations, common knowledge about the traffic safety for child occupants should be strengthen, and CRS will be required in cars to protect child occupants.
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| 5. |
- Wang, Zhaoming, et al.
(författare)
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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
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Ingår i: Human Molecular Genetics. - : Oxford University Press (OUP). - 0964-6906 .- 1460-2083. ; 23:24, s. 6616-6633
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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.
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| 6. |
- Yang, Chao, et al.
(författare)
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Computational fluid dynamics model development on transport phenomena coupling with reactions in intermediate temperature solid oxide fuel cells
- 2013
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Ingår i: Journal of Renewable and Sustainable Energy. - : AIP Publishing. - 1941-7012. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- A 3D model is developed to describe an anode-supported planar solid oxide fuel cell (SOFC), by ANSYS/Fluent evaluating reactions including methane steam reforming (MSR)/water-gas shift (WGSR) reactions in thick anode layer and H-2-O-2/CO-O-2 electrochemical reactions in anode active layer, coupled with heat, mass species, momentum, and ion/electron charges transport processes in SOFC. The predicted results indicate that electron/ion exchange appears in the very thin region in active layers (0.018 mm in anode and 0.01 mm in cathode), based on three phase boundary, operating temperature and concentration of reactants (mainly H-2). Active polarization happening in active layers dominates over concentration and ohmic losses. High gradient of current density exists near interface between electrode and solid conductor due to the block by gas channel. It is also found the reaction rates of MSR and WGSR along main flow direction and cell thickness direction decrease due to low concentration of fuel (CH4) caused by mass consumption. With increasing operating temperature from 978 K to 1088 K, the current density and the reaction rate of MSR are increased by 10.8% and 5.4%, respectively. While ion current density is 52.9% higher than in standard case, and H-2 is consumed by 5.1% more when ion conductivity is doubled. CO-O-2 has been considered in charge transfer reaction in anode active layer and it is found that the current density and species distributions are not sensitive, but WGSR reaction will be forced backwards to supply more CO for CO-O-2 electrochemical reaction. (V) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4798789]
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| 7. |
- Amer, Wael A., et al.
(författare)
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Liquid-crystalline azobenzene-containing ferrocene-based polymers : study on synthesis and properties of main-chain ferrocene-based polyesters with azobenzene in the side chain
- 2013
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Ingår i: Polymers for Advanced Technologies. - : Wiley. - 1042-7147 .- 1099-1581. ; 24:2, s. 181-190
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Tidskriftsartikel (refereegranskat)abstract
- Ferrocene-based polymers are characterized by their electrochemical activity, good redox properties, thermal, photochemical stability, and liquid crystallinity, and thus they have various applications in different fields. A comprehensive investigation on the synthesis and properties of three novel main-chain ferrocene-based polyesters with azobenzene in the side chain (MFPAS) was carried out. The main-chain ferrocene-based polyester, poly(N-phenyldiethanolamine 1,1'-ferrocene dicarboxylate (PPFD), was synthesized via the solution polycondensation reaction of 1,1'-ferrocenedicarbonyl chloride with phenyldiethanolamine (PDE). The novel MFPAS were synthesized via the post-polymerization azo-coupling reaction of PPFD with three different 4-substituted anilines including 4-nitroaniline, 4-aminobenzoic acid, and 4-aminobenzonitrile to produce 4-nitrophenylazo-functionalized-PPFD (PPFD-NT), 4-carboxyphenylazo-functionalized-PPFD (PPFD-CA), and 4-cyanophenylazo-functionalized-PPFD (PPFD-CN), respectively. All the synthesized polymers were characterized by 1H NMR spectroscopy, Fourier transform infrared spectroscopy, and UVvisible spectroscopy. In addition, powder X-ray diffraction patterns were measured for the synthesized polymers. The photoisomerization of the MFPAS was studied. The thermal properties of the MFPAS were studied using thermogravimetric analysis and differential scanning calorimetry. PPFD-CA and PPFD-CN were found to be more thermally stable than PPFD-NT. Finally, the liquid-crystalline properties of PPFD and the MFPAS were examined using polarized optical microscope. It was found that all the polymers possessed nematic phases and exhibited textures with schlieren disclinations.
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| 8. |
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| 9. |
- Chen, Jiguang, et al.
(författare)
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FEA of helmet-head injury protection based on motorcycle accident reconstruction
- 2013
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Ingår i: Proceedings - 2013 5th Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2013. - 9780769549323 ; , s. 570-573
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Konferensbidrag (refereegranskat)abstract
- Head impact usually causes fatalities of riders in motorcycle accidents. The use of helmet can protect head effectively and the study of head injury mechanism is useful in safety helmet design and head injury risk decrease. A real motorcycle-passenger car accident was reconstructed in order to simulate and analyze the motion, impact velocity, impact angle in the collision. In order to study the dynamic response of helmeted head during the accident impact processing, an effective helmet model was constructed and validated. Coupling with the finite element model of human head, the injury mechanism of head and relevant parameters of biomechanics were studied and the protection ability of helmet was analyzed. It was found that the presence of helmet reduces the probility of head injury.
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| 10. |
- Dai, Bing, et al.
(författare)
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A study on throw distance of electric bicycle and cyclist based on accident reconstruction
- 2013
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Ingår i: Proceedings - 2013 5th Conference on Measuring Technology and Mechatronics Automation, ICMTMA 2013. - 9780769549323 ; , s. 135-138
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Konferensbidrag (refereegranskat)abstract
- This paper aims to determine the correlation of the throw distance of cyclist and electric bicycle in traffic accidents with throw vehicle impact speed. A total of 22 vehicle-electric bicycle accidents were sampled from IVAC database, China. The selected accidents were reconstructed by using PC-Crash and Madymo programs. The relationship between throw distance and vehicle impact velocity was analyzed by using logistic regression model The relationship curves were obtained based on the calculated parameters. With increasing of the vehicle impact velocity, an increase of throw distance was observed. When the vehicle impact velocity was above 30km/h, the throw distance of electric bicycle was larger than that of cyclist. By comparing of results from the PC-Crash and MADYMO simulations with observations from in-depth accident investigation, the feasibility of the reconstruction method and the validity of the numerical model were evaluated. This research could provide a basis for further study on the dynamic response and injury prevention of cyclist.
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