| 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. |
- Ma, Ming-Guo, et al.
(författare)
-
Fabrication and characterization of Ag/calcium silicate core-shell nanocomposites
- 2011
-
Ingår i: Materials letters (General ed.). - : Elsevier BV. - 0167-577X .- 1873-4979. ; 65:19-20, s. 3069-3071
-
Tidskriftsartikel (refereegranskat)abstract
- The Ag/calcium silicate nanocomposite with core-shell nanostructure has been successfully synthesized using Ag solution, Ca(NO(3))(2)center dot 4H(2)O and Na(2)SiO(3)center dot 9H(2)O in ethanol/water mixed solvents at room temperature for 48 h. Ag solution was previously prepared by microwave-assisted method in ethylene glycol (EG) at 150 degrees C for 10 min. The nanocomposites consisted of Ag core and an amorphous calcium silicate shell. The XRD and EDS results confirmed that the product was the Ag/calcium silicate nanocomposite. The TEM micrographs indicated that the Ag/calcium silicate nanocomposite was core-shell nanoparticles. The effects of Ca (NO(3))(2)center dot 4H(2)O and Na(2)SiO(3)center dot 9H(2)O concentration on the shells of Ag/calcium silicate nanocomposite were investigated. The products were characterized by X-ray powder diffraction (XRD), transmission electron microscopy (TEM), and energy-dispersive X-ray spectra (EDS). This method is simple, fast and may be extended to the synthesis of the other kinds of core-shell nanocomposites.
|
|
| 3. |
- Castellani, Rudy J., et al.
(författare)
-
CD3 in Lewy pathology : does the abnormal recall of neurodevelopmental processes underlie Parkinson's disease
- 2011
-
Ingår i: Journal of neural transmission. - : Springer Science and Business Media LLC. - 0300-9564 .- 1435-1463. ; 118:1, s. 23-26
-
Tidskriftsartikel (refereegranskat)abstract
- CD3ζ is a subunit of the CD3 molecule that, until recently, appeared restricted to T cells and natural killer cells. However, experimental studies have demonstrated a role of CD3ζ in dendritic outgrowth in the visual system as well as in synaptic plasticity. Given the increasing evidence for uncharacteristic recapitulation of neurodevelopmental processes in neurodegenerative diseases, in this study, we evaluated brains from subjects with Parkinson's disease and Lewy body dementia for evidence of aberrant CD3 expression. Our data shows marked CD3ζ in association with the α-synuclein containing pathological lesions, i.e., Lewy bodies and Lewy neurites, in the brains of subjects with Parkinson's disease and Lewy body dementia. This finding raises the novel concept of CD3 dysregulation in these disorders as a pathogenic factor and also furthers the increasing evidence that the recall of aberrant neurodevelopmental processes underlies the pathogenesis of neurodegenerative diseases.
|
|
| 4. |
- Chen, X, et al.
(författare)
-
Shallow-terrace-like interface in dilute-bismuth GaSb/AlGaSb single quantum wells evidenced by photoluminescence
- 2013
-
Ingår i: Journal of Applied Physics. - : AIP Publishing. - 0021-8979 .- 1089-7550. ; 113:15, s. 153505-153507
-
Tidskriftsartikel (refereegranskat)abstract
- Photoluminescence (PL) measurements are performed on one GaSb/AlGaSb single-quantum-well (SQW) sample and two dilute-bismuth (Bi) GaSb/AlGaSb SQW samples grown at 360 and 380 °C, at low temperatures and under magnetic fields. Bimodal PL features are identified in the dilute-Bi samples, and to be accompanied by abnormal PL blueshift in the sample grown at 360 °C. The bimodal PL features are found to be from similar origins of band-to-band transition by magneto-PL evolution. Analysis indicates that the phenomenon can be well interpreted by the joint effect of interfacial large-lateral-scale islands and Al/Ga interdiffusion due to Bi incorporation. The interdiffusion introduces about 1-monolayer shrinkage to the effective quantum-well thickness, which is similar to the interfacial islands height, and the both together result in an unusual shallow-terrace-like interface between GaSbBi and AlGaSb. A phenomenological model is established, the Bi content of isoelectronic incorporation and the exciton reduced effective mass are estimated for the GaSbBi sample grown at 380 °C, and a value of about 21 meV/% is suggested for the bandgap bowing rate of GaSbBi. An effective routine is suggested for determining the Bi content and the depth of the shallow-terraces at interface in dilute-Bi SQW structures.
|
|
| 5. |
- Ding, G. Q., et al.
(författare)
-
Chemical vapor deposition of graphene on liquid metal catalysts
- 2013
-
Ingår i: Carbon. - : Elsevier BV. - 0008-6223. ; 53, s. 321-326
-
Tidskriftsartikel (refereegranskat)abstract
- Several molten metals and their alloys were used for graphene growth by atmosphere pressure chemical vapor deposition. It was found that liquid gallium (Ga) has very effective catalytic ability for graphene formation. Graphene with a controllable thickness and quality can be synthesized on a molten Ga surface only in a few minutes. Compared to solid catalysts, several new and unexpected results have been observed on Ga surface including graphene formation on a liquid surface at high temperature and keeping on a liquid surface at room temperature, time-dependent thickness control and a decrease in quality with increasing hydrogen flow. These growth characteristics can be attributed to the distinct differences in physical/chemical properties of liquid catalysts versus solids, and consequently distinct catalytic behaviors with the precursor gas. Other molten metals and alloys, including indium, tin, tin-nickle and tin-copper etc., were also explored for graphene synthesis. Use of liquid catalysts opens a new window for graphene synthesis.
|
|
| 6. |
- He, Shu-Lan, et al.
(författare)
-
Mitochondrial-related gene expression profiles suggest an important role of PGC-1alpha in the compensatory mechanism of endemic dilated cardiomyopathy.
- 2013
-
Ingår i: Experimental Cell Research. - : Elsevier. - 0014-4827 .- 1090-2422. ; 319:17, s. 2604-2616
-
Tidskriftsartikel (refereegranskat)abstract
- Keshan disease (KD) is an endemic dilated cardiomyopathy with unclear etiology. In this study, we compared mitochondrial-related gene expression profiles of peripheral blood mononuclear cells (PBMCs) derived from 16 KD patients and 16 normal controls in KD areas. Total RNA was isolated, amplified, labeled and hybridized to Agilent human 4 × 44k whole genome microarrays. Mitochondrial-related genes were screened out by the Third-Generation Human Mitochondria-Focused cDNA Microarray (hMitChip3). Quantitative real-time PCR, immunohistochemical and biochemical parameters related mitochondrial metabolism were conducted to validate our microarray results. In KD samples, 34 up-regulated genes (ratios ≥ 2.0) were detected by significance analysis of microarrays and ingenuity systems pathway analysis (IPA). The highest ranked molecular and cellular functions of the differentially regulated genes were closely related to amino acid metabolism, free radical scavenging, carbohydrate metabolism, and energy production. Using IPA, 40 significant pathways and four significant networks, involved mainly in apoptosis, mitochondrion dysfunction, and nuclear receptor signaling were identified. Based on our results, we suggest that PGC-1alpha regulated energy metabolism and anti-apoptosis might play an important role in the compensatory mechanism of KD. Our results may lead to the identification of potential diagnostic biomarkers for KD in PBMCs, and may help to understand the pathogenesis of KD.
|
|
| 7. |
- Jia, Ning, et al.
(författare)
-
Hydrothermal fabrication, characterization, and biological activity of cellulose/CaCO3 bionanocomposites
- 2012
-
Ingår i: Carbohydrate Polymers. - : Elsevier BV. - 0144-8617 .- 1879-1344. ; 88:1, s. 179-184
-
Tidskriftsartikel (refereegranskat)abstract
- Bionanocomposites with the combination of natural polymers and inorganic nanoparticles may induce unique properties and exhibit promising functions for different applications. Herein, we report a hydrothermal route to the preparation of cellulose/CaCO3 bionanocomposites using the cellulose solution. Ca(NO3)(2)center dot 4H(2)O and Na2SiO3 center dot 9H(2)O. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in NaOH-urea aqueous solution. The urea also acts as the CO32- source for the synthesis of CaCO3. The influences of several reaction parameters, such as the heating time, the heating temperature, and the types of additives on the products were investigated by X-ray powder diffraction, Fourier transform infrared spectrometry, scanning electron microscopy, thermogravimetric analysis, and differential thermal analysis. The experimental results demonstrated that the hydrothermal conditions had an effect on the morphology of the bionanocomposites. Cytotoxicity experiments indicated that the cellulose/CaCO3 bionanocomposites had good biocompatibility, so that the bionanocomposites could be ideal candidate for practical biomedical applications.
|
|
| 8. |
- Jia, Ning, et al.
(författare)
-
Hydrothermal Synthesis and Characterization of Cellulose-Carbonated Hydroxyapatite Nanocomposites in NaOH-Urea Aqueous Solution
- 2010
-
Ingår i: Science of Advanced Materials. - : American Scientific Publishers. - 1947-2935 .- 1947-2943. ; 2:2, s. 210-214
-
Tidskriftsartikel (refereegranskat)abstract
- Cellulose-carbonated hydroxyapatite (CHA) nanocomposites with CHA nanostructures dispersed in the cellulose matrix have been successfully synthesized using microcrystalline cellulose, CaCl2, and NaH2PO4 in NaOH-urea aqueous solution by hydrothermal method. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in NaOH-urea aqueous solution. The effects of the hydrothermal heating time, the heating temperature, and cellulose concentration on the products were investigated. The XRD and FTIR results indicated that the obtained products were the cellulose CHA nanocomposites. The SEM micrographs showed the CHA particles were dispersed in the cellulose matrix. The TGA and DTA indicated the cellulose content in the cellulose-CHA nanocomposites decreased with the decreasing raw cellulose. The size of CHA in nanocomposites decreased with the increasing preparation temperature. The products were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TG), differential thermal analysis (DTA), Fourier transform infrared spectrometry (FTIR), and scanning electron microscopy (SEM). This type of cellulose/CHA nanocomposites would be expected to be useful as novel biomedical material.
|
|
| 9. |
- Jia, Ning, et al.
(författare)
-
Microwave-assisted synthesis and characterization of cellulose-carbonated hydroxyapatite nanocomposites in NaOH-urea aqueous solution
- 2010
-
Ingår i: Materials letters (General ed.). - : Elsevier BV. - 0167-577X .- 1873-4979. ; 64:20, s. 2223-2225
-
Tidskriftsartikel (refereegranskat)abstract
- We report the microwave-assisted synthesis of the cellulose-carbonated hydroxyapatite (CHA) nanocomposites with CHA nanostructures dispersed in the cellulose matrix by using the cellulose solution, CaCl2, and NaH2PO4. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in NaOH-urea aqueous solution. The influences of the heating time and cellulose concentration on the products were also investigated. The X-ray powder diffraction (XRD) and Fourier transform infrared spectrometry (FT-IR) results indicated that the obtained products were the cellulose-CHA nanocomposites. The scanning electron microscopy (SEM) micrographs showed the CHA nanostructures were dispersed in the cellulose matrix. The thermal stability of the cellulose-CHA nanocomposites in air was investigated using thermogravimetric analysis (TGA) and differential thermal analysis (DTA). This method is simple, fast, low-cost and suitable for large-scale production of cellulose-based nanocomposites.
|
|
| 10. |
- Jia, Ning, et al.
(författare)
-
Synthesis and characterization of cellulose-silica composite fiber in ethanol/water mixed solvents
- 2011
-
Ingår i: BioResources. - 1930-2126. ; 6:2, s. 1186-1195
-
Tidskriftsartikel (refereegranskat)abstract
- Cellulose-silica composite fiber samples have been successfully synthesized using cellulose solution, tetraethoxysilane, and NH3 center dot H2O in ethanol/water mixed solvents at room temperature for 24 h. The cellulose solution was previously prepared by the dissolution of microcrystalline cellulose in a solvent mixture of N,N-dimethylacetamide (DMAc)/lithium chloride (LiCl). The effect of the tetraethoxysilane concentration on the product was investigated. The products were characterized by X-ray powder diffraction (XRD), thermogravimetric analysis (TG), differential scanning calorimetric analysis (DSC), scanning electron microscopy (SEM), Fourier transform infrared spectrometry (FT-IR), energy-dispersive X-ray spectrum (EDS), and cross polarization magic angle spinning (CP/MAS) solid state C-13-NMR. The morphology of the cellulose-silica composite fiber was investigated by SEM, while their composition was established from EDS measurements combined with the results of FT-IR spectral analysis and XRD patterns. The XRD, FT-IR and EDS results indicated that the obtained product was cellulose-silica composite fiber. The SEM micrographs showed that the silica particles were homogeneously dispersed in the cellulose fiber. The CP/MAS solid state C-13-NMR results indicated that the silica concentration had an influence on the crystallinity of the cellulose. This method is simple for preparation of cellulose-based composites.
|
|
