| 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. |
|
|
| 4. |
- Ai, Yue-Jie, 1982-, et al.
(författare)
-
Repair of DNA Dewar Photoproduct to (6-4) photoproduct in (6-4) Photolyase
- 2011
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 115:37, s. 10976-10982
-
Tidskriftsartikel (refereegranskat)abstract
- Dewar photoproduct (Dewar PP) is the valence isomer of (6-4) photoproduct ((6-4)PP) in photodamaged DNA. Compared to the extensive studied CPD photoproducts, the underlying repair mechanisms for the (6-4)PP, and especially for the Dewar PP, are not well-established to date. In this paper, the repair mechanism of DNA Dewar photoproduct T(dew)C in (6-4) photolyase was elucidated using hybrid density functional theory. Our results showed that, during the repair process, the T(dew)C has to isomerize to T(6-4)C photolesion first via direct C6'-N3' bond cleavage facilitated by electron injection. This isomerization mechanism is energetically much more efficient than other possible rearrangement pathways. The calculations provide a theoretical interpretation to recent experimental observations.
|
|
| 5. |
- Ai, Yue-Jie, et al.
(författare)
-
Theoretical Studies on Photoisomerizations of (6-4) and Dewar Photolesions in DNA
- 2010
-
Ingår i: Journal of Physical Chemistry B. - : American Chemical Society (ACS). - 1520-6106 .- 1520-5207. ; 114:44, s. 14096-14102
-
Tidskriftsartikel (refereegranskat)abstract
- The (6-4) photoproduct ((6-4) PP) is one of the main lesions in UV-induced DNA damage. The (6-4) PP and its valence isomer Dewar photoproduct (Dewar PP) can have a great threat of mutation and cancer but gained much less attention to date. In this study, with density functional theory (DFT) and the complete active space self-consistent field (CASSCF) methods, the photoisomerization processes between the (6-4) PP and the Dewar PP in the gas phase, the aqueous solution, and the photolyase have been carefully examined. Noticeably, the solvent effect is treated with the CASPT2//CASSCF/Amber (QM/MM) method. Our calculations show that the conical intersection (Cl) points play a crucial role in the photoisomerization reaction between the (6-4) PP and the Dewar PP in the gas and the aqueous solution. The ultrafast internal conversion between the S-2 ((1)pi pi*) and the So states via a distorted intersection point is found to be responsible for the formation of the Dewar PP lesion at 313 nm, as observed experimentally. For the reversed isomeric process, two channels involving the "dark" excited states have been identified. In addition to the above passages, in the photolyase, a new electron-injection isomerization process as an efficient way for the photorepair of the Dewar PP is revealed.
|
|
| 6. |
- Ai, Yue-Jie, et al.
(författare)
-
Theoretical studies on the isomerization mechanism of the ortho-green fluorescent protein chromophore
- 2012
-
Ingår i: Physical Chemistry, Chemical Physics - PCCP. - : Royal Society of Chemistry (RSC). - 1463-9076 .- 1463-9084. ; 14:38, s. 13409-13414
-
Tidskriftsartikel (refereegranskat)abstract
- We present a systematic theoretical investigation on the overall ground state and excited-state isomerization reaction mechanism of ortho-green fluorescent protein chromophore (o-HBDI) using the density functional theory and the multireference methods. The calculated results and subsequent analysis suggest the possible isomerization mechanism for o-HBDI. By comparison with experimental observation and detailed analysis, it is concluded that as initiated by the excited-state intramolecular proton transfer reaction, the conical intersection between the ground state and the excited state along the C4-C5 single-bond rotational coordinate is responsible for the rapid deactivation of o-HBDI.
|
|
| 7. |
- Anchordoqui, Luis A., et al.
(författare)
-
The Forward Physics Facility : Sites, experiments, and physics potential
- 2022
-
Ingår i: Physics reports. - : Elsevier. - 0370-1573 .- 1873-6270. ; 968, s. 1-50
-
Tidskriftsartikel (refereegranskat)abstract
- The Forward Physics Facility (FPF) is a proposal to create a cavern with the space and infrastructure to support a suite of far-forward experiments at the Large Hadron Collider during the High Luminosity era. Located along the beam collision axis and shielded from the interaction point by at least 100 m of concrete and rock, the FPF will house experiments that will detect particles outside the acceptance of the existing large LHC experiments and will observe rare and exotic processes in an extremely low-background environment. In this work, we summarize the current status of plans for the FPF, including recent progress in civil engineering in identifying promising sites for the FPF and the experiments currently envisioned to realize the FPF's physics potential. We then review the many Standard Model and new physics topics that will be advanced by the FPF, including searches for long-lived particles, probes of dark matter and dark sectors, high-statistics studies of TeV neutrinos of all three flavors, aspects of perturbative and non-perturbative QCD, and high-energy astroparticle physics.
|
|
| 8. |
- Chen, X, et al.
(författare)
-
Negative thermal quenching of below-bandgap photoluminescence in InPBi
- 2017
-
Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 110:5
-
Tidskriftsartikel (refereegranskat)abstract
- This paper reports a temperature-dependent (10-280 K) photoluminescence (PL) study of below-bandgap electron-hole recombinations and anomalous negative thermal quenching of PL intensity in InP1- xBix (x = 0.019 and 0.023). Four PL features are well resolved by curve-fitting of the PL spectra, of which the energies exhibit different temperature dependence. The integral intensities of the two high-energy features diminish monotonically as temperature rises up, while those of the two low-energy features decrease below but increase anomalously above 180 K. A phenomenological model is established that the residual electrons in the final state of the PL transition transfer into nonradiative state via thermal hopping, and the thermal hopping produces in parallel holes in the final state and hence enhances the radiative recombination significantly. A reasonable interpretation of the PL processes in InPBi is achieved, and the activation energies of the PL quenching and thermal hopping are deduced. © 2017 Author(s).
|
|
| 9. |
- Fang, Xing, et al.
(författare)
-
Microstructure and mechanical properties of the laser welded air-hardening steel joint
- 2024
-
Ingår i: Materials Characterization. - : Elsevier BV. - 1044-5803 .- 1873-4189. ; 213
-
Tidskriftsartikel (refereegranskat)abstract
- The decrease in mechanical properties of high-strength steel after welding is an important issue affecting the wide application of high-strength steel. Air-hardening steel is a high-strength steel suitable for lower body structural parts such as subframes. Its application process involves welding, hot forming and other processes. The present work investigates the microstructure and mechanical properties of the air-hardening steel laser welded joint that is air-cooled after hot forming in the two-phase zone (800 °C). The microstructure was characterized by electron backscattered diffraction (EBSD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The results show that during hot forming, the welded joint transforms from martensite to ferrite and acicular martensite, and the base metal transforms from ferrite to polygonal martensite and ferrite. The difference in martensite morphology between the welded joint and the base metal is attributed to the nucleation positions of austenite. The structural evolution of the welded joint and the base metal is accompanied with the annihilation and reproduction of dislocations, which results in significant changes in hardness. The hardness value dropped from the highest 430 HV to 271 HV in the welded joint, while increased from the lowest 184 HV to 203 HV in the base metal. After hot forming, the tensile strength of the welded sample is reduced by only 36 MPa, and the total elongation is slightly decreased by about 1.5% compared with the unwelded sample. The welded joint and the base metal have similar plastic deformation capabilities, since the acicular martensite in the welded joint displays good plastic deformation ability, and the dislocation density of the welded joint and the base metal is similar. Overall, the microstructure and dislocation density of the air-hardening steel welded joint after hot forming are similar to those of the base metal, which is responsible for the good mechanical properties of air-hardening steel welded joint.
|
|
| 10. |
- Huang, Zhen, et al.
(författare)
-
Recurrent chromosome reshuffling and the evolution of neo-sex chromosomes in parrots
- 2022
-
Ingår i: Nature Communications. - : Springer Nature. - 2041-1723. ; 13:1
-
Tidskriftsartikel (refereegranskat)abstract
- Parrots have undergone substantial karyotype evolution compared to most other birds. Here, Huang et al. analyze chromosome-level genome assemblies for four parrot species and elucidate the complex evolutionary history of parrot chromosomes. The karyotype of most birds has remained considerably stable during more than 100 million years' evolution, except for some groups, such as parrots. The evolutionary processes and underlying genetic mechanism of chromosomal rearrangements in parrots, however, are poorly understood. Here, using chromosome-level assemblies of four parrot genomes, we uncover frequent chromosome fusions and fissions, with most of them occurring independently among lineages. The increased activities of chromosomal rearrangements in parrots are likely associated with parrot-specific loss of two genes, ALC1 and PARP3, that have known functions in the repair of double-strand breaks and maintenance of genome stability. We further find that the fusion of the ZW sex chromosomes and chromosome 11 has created a pair of neo-sex chromosomes in the ancestor of parrots, and the chromosome 25 has been further added to the sex chromosomes in monk parakeet. Together, the combination of our genomic and cytogenetic analyses characterizes the complex evolutionary history of chromosomal rearrangements and sex chromosomes in parrots.
|
|
