| 1. |
- Christensen, Anna, et al.
(författare)
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Higher plant calreticulins have acquired specialized functions in arabidopsis
- 2010
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Ingår i: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 5:6, s. e11342-
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Tidskriftsartikel (refereegranskat)abstract
- Background: Calreticulin (CRT) is a ubiquitous ER protein involved in multiple cellular processes in animals, such as protein folding and calcium homeostasis. Like in animals, plants have evolved divergent CRTs, but their physiological functions are less understood. Arabidopsis contains three CRT proteins, where the two CRTs AtCRT1a and CRT1b represent one subgroup, and AtCRT3 a divergent member. Methodology/Principal Findings: Through expression of single Arabidopsis family members in CRT-deficient mouse fibroblasts we show that both subgroups have retained basic CRT functions, including ER Ca2+-holding potential and putative chaperone capabilities. However, other more general cellular defects due to the absence of CRT in the fibroblasts, such as cell adhesion deficiencies, were not fully restored. Furthermore, in planta expression, protein localization and mutant analyses revealed that the three Arabidopsis CRTs have acquired specialized functions. The AtCRT1a and CRT1b family members appear to be components of a general ER chaperone network. In contrast, and as recently shown, AtCRT3 is associated with immune responses, and is essential for responsiveness to the bacterial Pathogen-Associated Molecular Pattern (PAMP) elf18, derived from elongation factor (EF)-Tu. Whereas constitutively expressed AtCRT1a fully complemented Atcrt1b mutants, AtCRT3 did not. Conclusions/Significance: We conclude that the physiological functions of the two CRT subgroups in Arabidopsis have diverged, resulting in a role for AtCRT3 in PAMP associated responses, and possibly more general chaperone functions for AtCRT1a and CRT1b.
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| 2. |
- Jia, Yuehua, et al.
(författare)
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Efficient polymer bulk heterojunction solar cells with cesium acetate as the cathode interfacial layer
- 2013
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Ingår i: Renewable energy. - : Elsevier. - 0960-1481 .- 1879-0682. ; 50, s. 565-569
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Tidskriftsartikel (refereegranskat)abstract
- The enhanced performance of polymer solar cells based on regioregular poly(3-hexylthiophene) (P3HT) and methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester (PCBM) blend was achieved by using cesium acetate (CH3COOCs) as cathode buffer layer. Under 100 mW/cm(2) white light illumination, the device with 0.8 nm thick CH3COOCs as cathode buffer layer exhibits power conversion efficiency (PCE) as high as (4.16 +/- 0.02) %. Compared to the control devices without cathode buffer layer and with LiF as cathode buffer layer, the PCE is enhanced similar to 100% and similar to 31%, respectively. The introduction of the CH3COOCs buffer layer effectively improves the photo-generated charge collection. The Kelvin Probe measurement shows that the work function of the CH3COOCs is estimated to be -4.0 eV, which has an ideal energy band match with PCBM and a good property for electron collection. The static contact angle results indicated that the CH3COOCs with the hydrophobic CH3COO- group has an improved wettability between the buffer layer and the hydrophobic organic active layer surface, resulting in better interfacial contact and reduced contact resistance. The improved performance may be attributed to the dissociation of semi-conducting CH3COOCs upon deposition to liberate Cs with a low work function, which reduces the interface resistance of the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportation. Therefore, the CH3COOCs interlayer could be a promising alternative to LiF to improve the efficiency of the electron collection of polymer bulk heterojunction solar cells.
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| 3. |
- Liu, Shiping, et al.
(författare)
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Population Genomics Reveal Recent Speciation and Rapid Evolutionary Adaptation in Polar Bears
- 2014
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Ingår i: Cell. - : Elsevier BV. - 0092-8674 .- 1097-4172. ; 157:4, s. 785-794
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Tidskriftsartikel (refereegranskat)abstract
- Polar bears are uniquely adapted to life in the High Arctic and have undergone drastic physiological changes in response to Arctic climates and a hyper-lipid diet of primarily marine mammal prey. We analyzed 89 complete genomes of polar bear and brown bear using population genomic modeling and show that the species diverged only 479-343 thousand years BP. We find that genes on the polar bear lineage have been under stronger positive selection than in brown bears; nine of the top 16 genes under strong positive selection are associated with cardiomyopathy and vascular disease, implying important reorganization of the cardiovascular system. One of the genes showing the strongest evidence of selection, APOB, encodes the primary lipoprotein component of low-density lipoprotein (LDL); functional mutations in APOB may explain how polar bears are able to cope with life-long elevated LDL levels that are associated with high risk of heart disease in humans.
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| 4. |
- Ma, Chunyu, et al.
(författare)
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Plasmon-enhanced organic solar cells with solution-processed three-dimensional Ag nanosheets
- 2013
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Ingår i: Solar Energy Materials and Solar Cells. - : ELSEVIER SCIENCE BV, PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS. - 0927-0248 .- 1879-3398. ; 109, s. 227-232
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Tidskriftsartikel (refereegranskat)abstract
- The silver nanosheets (AgNSs) prepared via normal silver mirror reaction were used to improve the performance of organic solar cells. AgNSs with a size of about 100 nm in width and 10 nm in thickness formed a 3-D network on an indium tin oxide (ITO) surface. Organic solar cells with a structure of ITO/AgNSs/poly(3,4-ethylene dioxythiophene) poly(styrenesulfonate) (PEDOT:PSS)/poly(3-hexylthiophene) and [6,6]-phenyl C-61 butyric acid methyl ester (P3HT:PC61BM)/LiF/Al exhibited an open circuit voltage (V-oc) of 0.60 +/- 0.01 V, short circuit current density (J(sc)) of 11.16 +/- 0.08 mA/cm(2), a fill factor (FF) of 53.69 +/- 0.92%, and power conversion efficiency (PCE) of 3.60 +/- 0.06%. The PCEs of organic solar cells with 3-D AgNSs layers were 1.29 times that of the control device without 3-D AgNSs layer. We attributed the improvement of the efficiency to localized surface plasmon resonance (LSPR) induced by the 3-D network of AgNSs, which enhanced the light harvest of active layers, increased the probability of exciton generation and dissociation.
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| 5. |
- Neng, Lingling, et al.
(författare)
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Isolation and culture of endothelial cells, pericytes and perivascular resident macrophage-like melanocytes from the young mouse ear
- 2013
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Ingår i: Nature Protocols. - : Nature Publishing Group. - 1754-2189 .- 1750-2799. ; 8:4, s. 709-720
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Tidskriftsartikel (refereegranskat)abstract
- This protocol describes a growth medium-based approach for obtaining cochlear endothelial cells (ECs), pericytes (PCs) and perivascular resident macrophage-like melanocytes (PVM/Ms) from the stria vascularis of mice aged between P10 and P15 (P, postnatal day). The procedure does not involve mechanical or enzymatic digestion of the sample tissue. Explants of stria vascularis, 'mini-chips', are selectively cultured in growth medium, and primary cell lines are obtained in 7-10 d. The method is simple and reliable, and it provides high-quality ECs, PVM/Ms and PCs with a purity >90% after two passages. This protocol is suitable for producing primary culture cells from organs and tissues of small volume and high anatomical complexity, such as the inner ear capillaries. The highly purified primary cell lines enable cell culture-based in vitro modeling of cell-cell interactions, barrier control function and drug action.
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| 6. |
- Qin, Wenjing, et al.
(författare)
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Surface states of ZnO nanoparticles effect on the performance of inverted-organic solar cells
- 2013
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Ingår i: Journal of Renewable and Sustainable Energy. - : American Institute of Physics (AIP). - 1941-7012. ; 5:5
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Tidskriftsartikel (refereegranskat)abstract
- ZnO is a promising material used as the electron transport layer in the inverted organic solar cells (IOSCs). However, the electrical or photoelectric properties of ZnO nanoparticles are governed by the surface states of the nanoparticles. Here, we demonstrate that the large number of hydroxyl (-OH) existed on the ZnO nanoparticles films have a vast impact on the performance of IOSCs with the structure of ITO/ZnO/poly(3-hexylthiophene) (P3HT):[6,6]-phenyl C-61 butyric acid methyl ester (PCBM)/MoO3/Ag. The surface hydroxyl groups depredate active layer via elevating photocatalytic activity of the ZnO, hence deteriorate the device performance. Experimental results show that hydroxyl groups can be effectively detached from ZnO film by annealing. Hydroxyl groups detach more with increasing annealing temperature, resulting in less degradation of the active layer. Therefore, the efficiency is significantly improved due to increased photo-current density and decreased series resistance of IOSCs. The best device exhibits a power conversion efficiency of 3.05% after annealing at 150 degrees C.
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| 7. |
- Wang, Wenjing, et al.
(författare)
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Ligand-Structure Effect on the Formation of One-Dimensional Nanoscale Cu(II)-Schiff Base Complexes and Solvent-Mediated Shape Transformation
- 2012
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Ingår i: Crystal Growth & Design. - : American Chemical Society. - 1528-7483 .- 1528-7505. ; 12:5, s. 2707-2713
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Tidskriftsartikel (refereegranskat)abstract
- We report here a Cu(II)-Schiff base complex that can assemble into one-dimensional (1D) nanoscale fibers, belts, and rods under different synthetic conditions. The ligand-structure effect is investigated by modification of the ligand structure. The formation of a ID nanostructure was studied, and the formation of dimers was revealed as a key factor for 1D assembly. In dimethylformamide (DMF) medium, this complex represents one of the rare examples of low-molecular-weight "super-metallogelators" with a critical gelation concentration of 0.3 wt % for DMF. The ligand exhibits good selectivity toward different metal ions in terms of gel formation and only the Cu(II) complex forms gels. It is interesting that this metallogel is a kind of dynamic nanostructure, which can be transformed to rods with different aspect ratios via a solvent-mediated process under stimulation of ultrasound.
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| 8. |
- Wang, Yaling, et al.
(författare)
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Enhanced performance and stability in polymer photovoltaic cells using lithium benzoate as cathode interfacial layer
- 2011
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Ingår i: SOLAR ENERGY MATERIALS AND SOLAR CELLS. - : Elsevier Science B.V., Amsterdam.. - 0927-0248. ; 95:4, s. 1243-1247
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Tidskriftsartikel (refereegranskat)abstract
- We report the enhanced performance and stability of polymer solar cells based on regioregular poly(3-hexylthiophene)(P3HT) and methanofullerene [6,6]-phenyl C-61-butyric acid methyl ester (PCBM) blend using lithium benzoate (C6H5COOLi) as cathode buffer layer between the active layer and the Al cathode. The effects of the C6H5COOLi thickness on the performance of polymer solar cell are also investigated. Under 100 mW/cm(2) white light illumination, the device with 1 nm thick C6H5COOLi as cathode buffer layer exhibits power conversion efficiency (PCE) as high as 3.41 +/- 0.07% and the device stability is greatly extended. Compared to the solar cell with LiF/AI cathode, the PCE is increased ca. 9.4%. Introduction of C6H5COOLi buffer layer effectively increases the shunt resistance and improves the photo-generated charge collection. The improved performance may attribute to the dissociation of semi-conducting C6H5COOLi upon deposition to liberate Li with a low work function, which reduces the interface resistance of the active layer and the cathode and enhances the interior electric field that may result in efficient charge transportion. In addition, the C6H5COOLi layer may serve as an effective oxygen and moisture diffusion barrier for the organic solar cells. Therefore. C6H5COOLi is a promising candidate as an interlayer to improve the efficiency of electron collection and to reduce the ambience influence on the stability of polymer solar cells.
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| 9. |
- Zhang, Hua, et al.
(författare)
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Combating ovarian aging depends on the use of existing ovarian follicles, not on putative oogonial stem cells
- 2013
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Ingår i: Reproduction. - : Bioscientifica. - 1470-1626 .- 1741-7899. ; 146:6
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Tidskriftsartikel (refereegranskat)abstract
- Ovarian aging is characterized by both a reduction in egg quality and a drastic reduction in the number of ovarian follicles. It has been generally accepted for 60 years that a fixed population of primordial follicles is established in the ovaries during early life, and in most mammalian species, oocytes cannot renew themselves in postnatal or adult life. This dogma, however, has been challenged over the past decade. In this review, we summarize the recent studies on primordial follicles and putative oogonial stem cells and discuss what resources in the ovary might be more reliable and promising source tools for combating ovarian aging.
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| 10. |
- Zhang, Hua, et al.
(författare)
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Experimental evidence showing that no mitotically active female germline progenitors exist in postnatal mouse ovaries
- 2012
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Ingår i: Proceedings of the National Academy of Sciences of the United States of America. - : Proceedings of the National Academy of Sciences. - 0027-8424. ; 109:31, s. 12580-12585
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Tidskriftsartikel (refereegranskat)abstract
- It has been generally accepted for more than half a century that, in most mammalian species, oocytes cannot renew themselves in postnatal or adult life, and that the number of oocytes is already fixed in fetal or neonatal ovaries. This assumption, however, has been challenged over the past decade. In this study, we have taken an endogenous genetic approach to this question and generated a multiple fluorescent Rosa26(rbw/+); Ddx4-Cre germline reporter mouse model for in vivo and in vitro tracing of the development of female germline cell lineage. Through live cell imaging and de novo folliculogenesis experiments, we show that the Ddx4-expressing cells from postnatal mouse ovaries did not enter mitosis, nor did they contribute to oocytes during de novo folliculogenesis. Our results provide evidence that supports the traditional view that no postnatal follicular renewal occurs in mammals, and no mitotically active Ddx4-expressing female germline progenitors exist in postnatal mouse ovaries.
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