| 1. |
- Beal, Jacob, et al.
(författare)
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Robust estimation of bacterial cell count from optical density
- 2020
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Ingår i: Communications Biology. - : Springer Science and Business Media LLC. - 2399-3642. ; 3:1
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Tidskriftsartikel (refereegranskat)abstract
- Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.
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| 2. |
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| 3. |
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- 2019
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Tidskriftsartikel (refereegranskat)
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| 4. |
- 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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| 5. |
- Ariyawansa, Hiran A., et al.
(författare)
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Fungal diversity notes 111–252—taxonomic and phylogenetic contributions to fungal taxa
- 2015
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Ingår i: Fungal diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 75, s. 27-274
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Tidskriftsartikel (refereegranskat)abstract
- This paper is a compilation of notes on 142 fungal taxa, including five new families, 20 new genera, and 100 new species, representing a wide taxonomic and geographic range. The new families, Ascocylindricaceae, Caryosporaceae and Wicklowiaceae (Ascomycota) are introduced based on their distinct lineages and unique morphology. The new Dothideomycete genera Pseudomassariosphaeria (Amniculicolaceae), Heracleicola, Neodidymella and P s e u d o m i c ros p h a e r i o p s i s ( D id y m e l l a c e a e ) , P s e u d o p i t h o m y c e s ( D i d y m o s p h a e r i a c e a e ) , Brunneoclavispora, Neolophiostoma and Sulcosporium (Halotthiaceae), Lophiohelichrysum (Lophiostomataceae), G a l l i i c o l a , Popul o c re s c e n t i a a nd Va g i c o l a (Phaeosphaeriaceae), Ascocylindrica (Ascocylindricaceae), E l o n g a t o p e d i c e l l a t a ( R o u s s o e l l a c e a e ) , Pseudoasteromassaria (Latoruaceae) and Pseudomonodictys (Macrodiplodiopsidaceae) are introduced. The newly described species of Dothideomycetes (Ascomycota) are Pseudomassariosphaeria bromicola (Amniculicolaceae), Flammeascoma lignicola (Anteagloniaceae), Ascocylindrica marina (Ascocylindricaceae) , Lembosia xyliae (Asterinaceae), Diplodia crataegicola and Diplodia galiicola ( B o t r yosphae r i a cea e ) , Caryospor a aquat i c a (Caryosporaceae), Heracleicola premilcurensis and Neodi dymell a thai landi cum (Didymellaceae) , Pseudopithomyces palmicola (Didymosphaeriaceae), Floricola viticola (Floricolaceae), Brunneoclavispora bambusae, Neolophiostoma pigmentatum and Sulcosporium thailandica (Halotthiaceae), Pseudoasteromassaria fagi (Latoruaceae), Keissleriella dactylidicola (Lentitheciaceae), Lophiohelichrysum helichrysi (Lophiostomataceae), Aquasubmersa japonica (Lophiotremataceae) , Pseudomonodictys tectonae (Macrodiplodiopsidaceae), Microthyrium buxicola and Tumidispora shoreae (Microthyriaceae), Alloleptosphaeria clematidis, Allophaeosphaer i a c y t i s i , Allophaeosphae r i a subcylindrospora, Dematiopleospora luzulae, Entodesmium artemisiae, Galiicola pseudophaeosphaeria, Loratospora(Basidiomycota) are introduced together with a new genus Neoantrodiella (Neoantrodiellaceae), here based on both morphology coupled with molecular data. In the class Agaricomycetes, Agaricus pseudolangei, Agaricus haematinus, Agaricus atrodiscus and Agaricus exilissimus (Agaricaceae) , Amanita m e l l e i a l b a , Amanita pseudosychnopyramis and Amanita subparvipantherina (Amanitaceae), Entoloma calabrum, Cora barbulata, Dictyonema gomezianum and Inocybe granulosa (Inocybaceae), Xerocomellus sarnarii (Boletaceae), Cantharellus eucalyptorum, Cantharellus nigrescens, Cantharellus tricolor and Cantharellus variabilicolor (Cantharellaceae), Cortinarius alboamarescens, Cortinarius brunneoalbus, Cortinarius ochroamarus, Cortinarius putorius and Cortinarius seidlii (Cortinariaceae), Hymenochaete micropora and Hymenochaete subporioides (Hymenochaetaceae), Xylodon ramicida (Schizoporaceae), Colospora andalasii (Polyporaceae), Russula guangxiensis and Russula hakkae (Russulaceae), Tremella dirinariae, Tremella graphidis and Tremella pyrenulae (Tremellaceae) are introduced. Four new combinations Neoantrodiella gypsea, Neoantrodiella thujae (Neoantrodiellaceae), Punctulariopsis cremeoalbida, Punctulariopsis efibulata (Punctulariaceae) are also introduced here for the division Basidiomycota. Furthermore Absidia caatinguensis, Absidia koreana and Gongronella koreana (Cunninghamellaceae), Mortierella pisiformis and Mortierella formosana (Mortierellaceae) are newly introduced in the Zygomycota, while Neocallimastix cameroonii and Piromyces irregularis (Neocallimastigaceae) ar e i n t roduced i n the Neocallimastigomycota. Reference specimens or changes in classification and notes are provided for Alternaria ethzedia, Cucurbitaria ephedricola, Austropleospora, Austropleospora archidendri, Byssosphaeria rhodomphala, Lophiostoma caulium, Pseudopithomyces maydicus, Massariosphaeria, Neomassariosphaeria and Pestalotiopsis montellica.
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| 6. |
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| 7. |
- Bakken, TE, et al.
(författare)
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Comparative cellular analysis of motor cortex in human, marmoset and mouse
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 598:7879, s. 111-
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Tidskriftsartikel (refereegranskat)abstract
- The primary motor cortex (M1) is essential for voluntary fine-motor control and is functionally conserved across mammals1. Here, using high-throughput transcriptomic and epigenomic profiling of more than 450,000 single nuclei in humans, marmoset monkeys and mice, we demonstrate a broadly conserved cellular makeup of this region, with similarities that mirror evolutionary distance and are consistent between the transcriptome and epigenome. The core conserved molecular identities of neuronal and non-neuronal cell types allow us to generate a cross-species consensus classification of cell types, and to infer conserved properties of cell types across species. Despite the overall conservation, however, many species-dependent specializations are apparent, including differences in cell-type proportions, gene expression, DNA methylation and chromatin state. Few cell-type marker genes are conserved across species, revealing a short list of candidate genes and regulatory mechanisms that are responsible for conserved features of homologous cell types, such as the GABAergic chandelier cells. This consensus transcriptomic classification allows us to use patch–seq (a combination of whole-cell patch-clamp recordings, RNA sequencing and morphological characterization) to identify corticospinal Betz cells from layer 5 in non-human primates and humans, and to characterize their highly specialized physiology and anatomy. These findings highlight the robust molecular underpinnings of cell-type diversity in M1 across mammals, and point to the genes and regulatory pathways responsible for the functional identity of cell types and their species-specific adaptations.
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| 8. |
- Callaway, EM, et al.
(författare)
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A multimodal cell census and atlas of the mammalian primary motor cortex
- 2021
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 1476-4687 .- 0028-0836. ; 598:7879, s. 86-102
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Tidskriftsartikel (refereegranskat)abstract
- Here we report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties and cellular resolution input–output mapping, integrated through cross-modal computational analysis. Our results advance the collective knowledge and understanding of brain cell-type organization1–5. First, our study reveals a unified molecular genetic landscape of cortical cell types that integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a consensus taxonomy of transcriptomic types and their hierarchical organization that is conserved from mouse to marmoset and human. Third, in situ single-cell transcriptomics provides a spatially resolved cell-type atlas of the motor cortex. Fourth, cross-modal analysis provides compelling evidence for the transcriptomic, epigenomic and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types. We further present an extensive genetic toolset for targeting glutamatergic neuron types towards linking their molecular and developmental identity to their circuit function. Together, our results establish a unifying and mechanistic framework of neuronal cell-type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties.
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| 9. |
- Hu, Li-Peng, et al.
(författare)
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Terbinafine prevents colorectal cancer growth by inducing dNTP starvation and reducing immune suppression
- 2022
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Ingår i: Molecular Therapy. - : Elsevier BV. - 1525-0024 .- 1525-0016. ; 30:10, s. 3284-3299
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Tidskriftsartikel (refereegranskat)abstract
- Existing evidence indicates that gut fungal dysbiosis might play a key role in the pathogenesis of colorectal cancer (CRC). We sought to explore whether reversing the fungal dysbiosis by terbinafine, an approved antifungal drug, might inhibit the development of CRC. A population-based study from Sweden identified a total of 185 patients who received terbinafine after their CRC diagnosis and found that they had a decreased risk of death (hazard ratio=0.50) and metastasis (hazard ratio=0.44) compared with patients without terbinafine administration. In multiple mouse models of CRC, administration of terbinafine decreased the fungal load, the fungus-induced myeloid-derived suppressor cell (MDSC) expansion, and the tumor burden. Fecal microbiota transplantation from mice without terbinafine treatment reversed MDSC infiltration and partially restored tumor proliferation. Mechanistically, terbinafine directly impaired tumor cell proliferation by reducing the ratio of nicotinamide adenine dinucleotide phosphate (NADP+) to reduced form of nicotinamide adenine dinucleotide phosphate (NADPH), suppressing the activity of glucose-6-phosphate dehydrogenase (G6PD), resulting in nucleotide synthesis disruption, deoxyribonucleotide (dNTP) starvation and cell cycle arrest. Collectively, terbinafine can inhibit CRC by reversing fungal dysbiosis, suppressing tumor cell proliferation, inhibiting fungus-induced MDSC infiltration, and restoring antitumor immune response.
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| 10. |
- Jayasiri, Subashini C., et al.
(författare)
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The Faces of Fungi database: fungal names linked with morphology, phylogeny and human impacts
- 2015
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Ingår i: Fungal diversity. - : Springer Science and Business Media LLC. - 1560-2745 .- 1878-9129. ; 74:1, s. 3-18
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Tidskriftsartikel (refereegranskat)abstract
- Taxonomic names are key links between various databases that store information on different organisms. Several global fungal nomenclural and taxonomic databases (notably Index Fungorum, Species Fungorum and MycoBank) can be sourced to find taxonomic details about fungi, while DNA sequence data can be sourced from NCBI, EBI and UNITE databases. Although the sequence data may be linked to a name, the quality of the metadata is variable and generally there is no corresponding link to images, descriptions or herbarium material. There is generally no way to establish the accuracy of the names in these genomic databases, other than whether the submission is from a reputable source. To tackle this problem, a new database (FacesofFungi), accessible at www.facesoffungi.org (FoF) has been established. This fungal database allows deposition of taxonomic data, phenotypic details and other useful data, which will enhance our current taxonomic understanding and ultimately enable mycologists to gain better and updated insights into the current fungal classification system. In addition, the database will also allow access to comprehensive metadata including descriptions of voucher and type specimens. This database is user-friendly, providing links and easy access between taxonomic ranks, with the classification system based primarily on molecular data (from the literature and via updated web-based phylogenetic trees), and to a lesser extent on morphological data when molecular data are unavailable. In FoF species are not only linked to the closest phylogenetic representatives, but also relevant data is provided, wherever available, on various applied aspects, such as ecological, industrial, quarantine and chemical uses. The data include the three main fungal groups (Ascomycota, Basidiomycota, Basal fungi) and fungus-like organisms. The FoF webpage is an output funded by the Mushroom Research Foundation which is an NGO with seven directors with mycological expertise. The webpage has 76 curators, and with the help of these specialists, FoF will provide an updated natural classification of the fungi, with illustrated accounts of species linked to molecular data. The present paper introduces the FoF database to the scientific community and briefly reviews some of the problems associated with classification and identification of the main fungal groups. The structure and use of the database is then explained. We would like to invite all mycologists to contribute to these web pages.
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| 11. |
- Kristanl, Matej, et al.
(författare)
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The Seventh Visual Object Tracking VOT2019 Challenge Results
- 2019
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Ingår i: 2019 IEEE/CVF INTERNATIONAL CONFERENCE ON COMPUTER VISION WORKSHOPS (ICCVW). - : IEEE COMPUTER SOC. - 9781728150239 ; , s. 2206-2241
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Konferensbidrag (refereegranskat)abstract
- The Visual Object Tracking challenge VOT2019 is the seventh annual tracker benchmarking activity organized by the VOT initiative. Results of 81 trackers are presented; many are state-of-the-art trackers published at major computer vision conferences or in journals in the recent years. The evaluation included the standard VOT and other popular methodologies for short-term tracking analysis as well as the standard VOT methodology for long-term tracking analysis. The VOT2019 challenge was composed of five challenges focusing on different tracking domains: (i) VOT-ST2019 challenge focused on short-term tracking in RGB, (ii) VOT-RT2019 challenge focused on "real-time" short-term tracking in RGB, (iii) VOT-LT2019 focused on long-term tracking namely coping with target disappearance and reappearance. Two new challenges have been introduced: (iv) VOT-RGBT2019 challenge focused on short-term tracking in RGB and thermal imagery and (v) VOT-RGBD2019 challenge focused on long-term tracking in RGB and depth imagery. The VOT-ST2019, VOT-RT2019 and VOT-LT2019 datasets were refreshed while new datasets were introduced for VOT-RGBT2019 and VOT-RGBD2019. The VOT toolkit has been updated to support both standard short-term, long-term tracking and tracking with multi-channel imagery. Performance of the tested trackers typically by far exceeds standard baselines. The source code for most of the trackers is publicly available from the VOT page. The dataset, the evaluation kit and the results are publicly available at the challenge website(1).
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| 12. |
- Persson, Ninni, et al.
(författare)
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Age and sex related differences in subcortical brain iron concentrations among healthy adults
- 2015
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Ingår i: NeuroImage. - : Elsevier BV. - 1053-8119 .- 1095-9572. ; 122, s. 385-398
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Tidskriftsartikel (refereegranskat)abstract
- Age and sex can influence brain iron levels. We studied the influence of these variables on deep gray matter magnetic susceptibilities. In 183 healthy volunteers (44.7 ± 14.2 years, range 20–69, ♀ 49%), in vivo quantitative susceptibility mapping (QSM) at 1.5 T was performed to estimate brain iron accumulation in the following regions of interest (ROIs): caudate nucleus (Cd), putamen (Pt), globus pallidus (Gp), thalamus (Th), pulvinar (Pul), red nucleus (Rn), substantia nigra (Sn) and the cerebellar dentate nuclei (Dn). We gauged the influence of age and sex on magnetic susceptibility by specifying a series of structural equation models. The distributions of susceptibility varied in degree across the structures, conforming to histologic findings (Hallgren and Sourander, 1958), with the highest degree of susceptibility in the Gp and the lowest in the Th. Iron increase correlated across several ROIs, which may reflect an underlying age-related process. Advanced age was associated with a particularly strong linear rise of susceptibility in the striatum. Nonlinear age trends were found in the Rn, where they were the most pronounced, followed by the Pul and Sn, while minimal nonlinear trends were observed for the Pt, Th, and Dn. Moreover, sex related variations were observed, so that women showed lower levels of susceptibility in the Sn after accounting for age. Regional susceptibility of the Pul increased linearly with age in men but exhibited a nonlinear association with age in women with a leveling off starting from midlife. Women expected to be post menopause (+ 51 years) showed lower total magnetic susceptibility in the subcortical gray matter. The current report not only is consistent with previous reports of age related variations of brain iron, but also adds to the current knowledge by reporting age-related changes in less studied, smaller subcortical nuclei. This is the first in-vivo report to show lower total subcortical brain iron levels selectively in women from midlife, compared to men and younger women. These results encourage further assessment of sex differences in brain iron. We anticipate that age and sex are important co-factors to take into account when establishing a baseline level for differentiating pathologic neurodegeneration from healthy aging. The variations in regional susceptibility reported herein should be evaluated further using a longitudinal study design to determine within-person changes in aging.
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| 13. |
- Shen, Ting, et al.
(författare)
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A structure of CdS/CuxS quantum dots sensitized solar cells
- 2016
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Ingår i: Applied Physics Letters. - : AIP Publishing. - 0003-6951 .- 1077-3118. ; 108:21
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Tidskriftsartikel (refereegranskat)abstract
- This work introduces a type of CdS/CuxS quantum dots (QDs) as sensitizers in quantum dot sensitized solar cells by in-situ cationic exchange reaction method where CdS photoanode is directly immersed in CuCl2 methanol solution to replace Cd2+ by Cu2+. The p-type CuxS layer on the surface of the CdS QDs can be considered as hole transport material, which not only enhances the light harvesting of photoanode but also boosts the charge separation after photo-excitation. Therefore, both the electron collection efficiency and power conversion efficiency of the solar cell are improved from 80% to 92% and from 1.21% to 2.78%, respectively.
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| 14. |
- Shen, Ting, et al.
(författare)
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Surface Engineering of Quantum Dots for Remarkably High Detectivity Photodetectors.
- 2018
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Ingår i: The Journal of Physical Chemistry Letters. - : American Chemical Society (ACS). - 1948-7185. ; 9:12, s. 3285-3294
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Tidskriftsartikel (refereegranskat)abstract
- Ternary alloyed CdSexTe1–x colloidal QDs trap-passivated by iodide-based ligands (TBAI) are developed as building blocks for UV–NIR photodetectors. Both the few surface traps and high loading of QDs are obtained by in situ ligand exchange with TBAI. The device is sensitive to a broad wavelength range covering the UV–NIR region (300–850 nm), showing an excellent photoresponsivity of 53 mA/W, a fast response time of ≪0.02s, and remarkably high detectivity values of 8 × 1013 Jones at 450 nm and 1 × 1013 Jones at 800 nm without an external bias voltage. Such performance is superior to what has been reported earlier for QD-based photodetectors. The photodetector exhibits excellent stability, keeping 98% of photoelectric responsivity after 2 months of illumination in air even without encapsulation. In addition, the semitransparent device is successfully fabricated using a Ag nanowires/polyimide transparent substrate. Such self-powered photodetectors with fast response speed and a stable, broad-band response are expected to function under a broad range of environmental conditions.
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| 15. |
- Song, Kaixuan, et al.
(författare)
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Spray coated colloidal quantum dot films for broadband photodetectors
- 2019
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Ingår i: Nanomaterials. - : MDPI AG. - 2079-4991. ; 9:12
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Tidskriftsartikel (refereegranskat)abstract
- A technique for scalable spray coating of colloidal CdSeTe quantum dots (QDs) for photovoltaics and photodetector applications is presented. A mixture solvent with water and ethanol was introduced to enhance the adhesive force between QDs and the substrate interface. The performance of the detector reached the highest values with 40 spray coating cycles of QD deposition. The photodetectors without bias voltage showed broadband response in the wavelength range of 300–800 nm, and high responsivity of 15 mA/W, detectivity of more than 1011 Jones and rise time of 0.04 s. A large size QD-logo pattern film (10 × 10 cm2 ) prepared by the spray coating process displayed excellent uniformity of thickness and absorbance. The large area detectors (the active area 1 cm2 ) showed almost the same performance as the typical laboratory-size ones (the active area 0.1 cm2 ). Our study demonstrates that the spray coating is a very promising film fabrication technology for the industrial-scale production of optoelectronic devices.
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| 16. |
- Tian, Pengfei, et al.
(författare)
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Folding pathway of an Ig domain is conserved on and off the ribosome
- 2018
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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 .- 1091-6490. ; 115:48, s. E11284-E11293
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Tidskriftsartikel (refereegranskat)abstract
- Proteins that fold cotranslationally may do so in a restricted configurational space, due to the volume occupied by the ribosome. How does this environment, coupled with the close proximity of the ribosome, affect the folding pathway of a protein? Previous studies have shown that the cotranslational folding process for many proteins, including small, single domains, is directly affected by the ribosome. Here, we investigate the cotranslational folding of an all-beta Ig domain, titin I27. Using an arrest peptide-based assay and structural studies by cryo-EM, we show that I27 folds in the mouth of the ribosome exit tunnel. Simulations that use a kinetic model for the force dependence of escape from arrest accurately predict the fraction of folded protein as a function of length. We used these simulations to probe the folding pathway on and off the ribosome. Our simulations-which also reproduce experiments on mutant forms of I27-show that I27 folds, while still sequestered in the mouth of the ribosome exit tunnel, by essentially the same pathway as free I27, with only subtle shifts of critical contacts from the C to the N terminus.
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| 17. |
- Tu, Suo, et al.
(författare)
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Improvement of the thermoelectric properties of PEDOT:PSS films via DMSO addition and DMSO/salt post-treatment resolved from a fundamental view
- 2022
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 429
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Tidskriftsartikel (refereegranskat)abstract
- The combination of dimethyl sulfoxide (DMSO)-solvent doping and physical-chemical DMSO/salt de-doping in a sequence has been used to improve the thermoelectric (TE) properties of poly(3,4-ethylenedioxythiophene):poly (4-styrenesulfonate) (PEDOT:PSS) films. A high power factor of ca.105.2 mu W m(-1) K-2 has been achieved for the PEDOT:PSS film after post-treatment with 10 % sodium sulfite (Na2SO3) in the DMSO/salt mixture (v/v), outperforming sodium bicarbonate (NaHCO3). The initial DMSO-doping treatment induces a distinct phase separation by facilitating the aggregation of the PEDOT molecules. At the same time, the subsequent DMSO/salt dedoping post-treatment strengthens the selective removal of the surplus non-conductive PSS chains. Substantial alterations in the oxidation level, chain conformations, PEDOT crystallites and their preferential orientation are observed upon treatment on the molecular level. At the mesoscale level, the purification and densification of PEDOT-rich domains enable the realization of inter-grain coupling by the formation of the electronically well-percolated network. Thereby, both electrical conductivity and Seebeck coefficient are optimized.
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| 18. |
- Wang, Jin, et al.
(författare)
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A review on nanofluid stability : preparation and application
- 2023
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Ingår i: Renewable and Sustainable Energy Reviews. - 1364-0321. ; 188
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Tidskriftsartikel (refereegranskat)abstract
- Due to excellent thermal performance and application prospects, nanofluids are attracting many researchers to pay more attention to new types of heat transfer fluids. However, previous studies have focused on the effects of nanofluids on thermophysical properties without considering the limitation of dispersion stability in practical applications. Excellent nanofluid stability is judged with the zeta potential value above 30 mV. Unstable nanofluids block the fluid flow in heat exchanger channels, which reduces the system performance by over 23 %. Based on a systematic review of improving nanofluid stability, this research discusses the preparation, characterisation, influencing factor, dispersion mechanism, and dispersion method on nanofluid stability. Four methods for improving nanofluid stability are summarised. The nanofluid is stable at pH values between 4 and 9 b y controlling its ionic concentration. The nanofluid concentration is required below 2 % to improve the repulsion between nanoparticles. The stability of the nanofluid is affected by the type and amount of the surfactant, which fails to improve the nanofluid stability at temperature above 60 °C. In addition, the molecular forces between the mixed nanofluids enhance the stability of the nanofluid. This review examines the variation patterns of nanofluid stability and the effect of stability on heat transfer. It is expected to identify some opportunities and demonstrate future challenges in both the in-lab research and the commercialisation of nanofluids.
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| 19. |
- Wang, Yizhi, et al.
(författare)
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SynQuant : an automatic tool to quantify synapses from microscopy images
- 2020
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Ingår i: Bioinformatics. - : Oxford University Press (OUP). - 1367-4803 .- 1367-4811 .- 1460-2059. ; 36:5, s. 1599-1606
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Tidskriftsartikel (refereegranskat)abstract
- Motivation: Synapses are essential to neural signal transmission. Therefore, quantification of synapses and related neurites from images is vital to gain insights into the underlying pathways of brain functionality and diseases. Despite the wide availability of synaptic punctum imaging data, several issues are impeding satisfactory quantification of these structures by current tools. First, the antibodies used for labeling synapses are not perfectly specific to synapses. These antibodies may exist in neurites or other cell compartments. Second, the brightness of different neurites and synaptic puncta is heterogeneous due to the variation of antibody concentration and synapse-intrinsic differences. Third, images often have low signal to noise ratio due to constraints of experiment facilities and availability of sensitive antibodies. These issues make the detection of synapses challenging and necessitates developing a new tool to easily and accurately quantify synapses.Results: We present an automatic probability-principled synapse detection algorithm and integrate it into our synapse quantification tool SynQuant. Derived from the theory of order statistics, our method controls the false discovery rate and improves the power of detecting synapses. SynQuant is unsupervised, works for both 2D and 3D data, and can handle multiple staining channels. Through extensive experiments on one synthetic and three real datasets with ground truth annotation or manually labeling, SynQuant was demonstrated to outperform peer specialized unsupervised synapse detection tools as well as generic spot detection methods.
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| 20. |
- Weindl, Christian L., et al.
(författare)
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Effect of Solvent Vapor Annealing on Diblock Copolymer-Templated Mesoporous Si/Ge/C Thin Films : Implications for Li-Ion Batteries
- 2022
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Ingår i: ACS Applied Nano Materials. - : American Chemical Society (ACS). - 2574-0970. ; 5:5, s. 7278-7287
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Tidskriftsartikel (refereegranskat)abstract
- Although amphiphilic diblock copolymer templating of inorganic materials such as TiO2 is already well investigated, sol-gel synthesis routines for porous silicon and germanium are relatively rare. Therefore, especially in the field of Li-ion batteries, novel synthesis routines with the possibility to tune the silicon and germanium ratio and the morphology in the nanometer regime are of high interest. Here, we demonstrate a synthesis method that allows a change of morphology and elemental composition with minimal effort. We evidence a morphological transformation in the nanometer regime with real space (scanning electron microscopy) and complementary reciprocal space analysis methods (grazing-incidence small-angle X-ray scattering). Although energy-dispersive X-ray spectroscopy (EDS) reveals a considerable amount of oxygen in the thin film, crystalline Ge in the bulk is detected with powder Xray diffraction (PXRD) and Raman spectroscopy. Due to the system's simplicity, chemical mass production options such as roll-to-roll or slot-die printing can also be considered high-yield methods compared to standard synthesis routines.
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| 21. |
- Weindl, Christian L., et al.
(författare)
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Toluene‐Mediated Morphology Tuning of Diblock Copolymer‐Templated Porous Si/Ge/K/C Thin Films for Li‐Ion Batteries
- 2023
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Ingår i: Advanced Energy and Sustainability Research. - : Wiley. - 2699-9412 .- 2699-9412. ; 4:10
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Tidskriftsartikel (refereegranskat)abstract
- Amphiphilic diblock copolymer poly(styrene-b-ethylene oxide) templating in combination with sol–gel chemistry is utilized to synthesize porous mixed silicon/germanium/potassium/carbon (Si/Ge/K/C) thin films. As a Si/Ge source, the dissolvable Zintl phase K12Si12Ge5 is used. The toluene-mediated morphological changes in the porous mixed Si/Ge/K/C thin films are studied with scanning electron microscopy and grazing incidence small/wide-angle X-Ray scattering. A dichloromethane solvent vapor annealing step is applied to study the additional morphological transformation inside the films. Since Ge and Si are promising anode materials in Li-ion batteries, CR2032 half-cells are manufactured with the porous mixed Si/Ge/K/C thin films and characterized by cyclic voltammograms, cycling, and impedance spectroscopy.
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| 22. |
- Wienhold, Kerstin S., et al.
(författare)
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Following In Situ the Evolution of Morphology and Optical Properties during Printing of Thin Films for Application in Non-Fullerene Acceptor Based Organic Solar Cells
- 2020
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Ingår i: ACS Applied Materials and Interfaces. - : AMER CHEMICAL SOC. - 1944-8244 .- 1944-8252. ; 12:36, s. 40381-40392
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Tidskriftsartikel (refereegranskat)abstract
- In situ printing gives insight into the evolution of morphology and optical properties during slot-die coating of active layers for application in organic solar cells and enables an upscaling and optimization of the thin film deposition process and the photovoltaic performance. Active layers based on the conjugated polymer donor with benzodithiophene units PBDB-T-2Cl and the non-fullerene small-molecule acceptor IT-4F are printed with a slot-die coating technique and probed in situ with grazing incidence small-angle X-ray scattering, grazing incidence wide-angle X-ray scattering, and ultraviolet/visible light spectroscopy. The formation of the morphology is followed from the liquid state to the final dry film for different printing conditions (at 25 and 35 degrees C), and five regimes of film formation are determined. The morphological changes are correlated to changing optical properties. During the film formation, crystallization of the non-fullerene small-molecule acceptor takes place and polymer domains with sizes of some tens of nanometers emerge. A red shift of the optical band gap and a broadening of the absorbance spectrum occurs, which allow for exploiting the sun spectrum more efficiently and are expected to have a favorable effect on the solar cell performance.
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| 23. |
- Xiao, Tianxiao, et al.
(författare)
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Autonomous self-healing hybrid energy harvester based on the combination of triboelectric nanogenerator and quantum dot solar cell
- 2024
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Ingår i: Nano Energy. - : Elsevier BV. - 2211-2855 .- 2211-3282. ; 125
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Tidskriftsartikel (refereegranskat)abstract
- Realization of multi-source energy harvesting with one single device would maximize power output. Thus, it is emerging as a promising strategy towards renewable energy generation and has attracted worldwide attention in the past decades. Capable of capturing mechanical energy that is ubiquitous in the ambient environment, triboelectric nanogenerator (TENG) has been considered a novel yet effective source towards next-generation energy harvesting. In this work, a flexible hybrid energy harvester (HEH) is developed via the rational integration of autonomous self-healing TENG and high bending-stable lead sulfide quantum dot (PbS QD) solar cell, enabling independent electricity generation by two different mechanisms. The single-electrode mode TENG component with self-healing is realized by a polydimethylsiloxane/Triton X-100 (PDMS/TX100) mixture as the dielectric layer and the shared gold (Au) electrode, which generates 0.39 µA of output current (Iout), 24.6 V of output voltages (Vout), 15.4 nC of transfer charges (Qsc), and 7.80 mW m−2 of output power peak density. The thin-film solar cell component is based on a PbS QD layer as the light absorber with a planar structure fabricated under low-cost and compatible conditions, achieving 22.8 mA cm−2 of short-circuit current density (Jsc) and 4.92% of power conversion efficiency (PCE). As a proof of concept, an electronic watch is successfully powered by harnessing ambient mechanical and solar energy with a hybridized energy cell. This approach will offer more opportunities to construct a versatile platform towards remote monitoring and smart home systems.
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| 24. |
- Yang, Xian, et al.
(författare)
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Thermal-hydraulic performance of printed circuit heat exchangers with various channel shapes under rolling conditions
- 2024
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Ingår i: Applied Thermal Engineering. - 1359-4311. ; 244
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Tidskriftsartikel (refereegranskat)abstract
- The floating liquefied natural gas (LNG) facilities are located in deep oceans, where the harsh ocean conditions cause the facilities to sway and tilt. The rolling conditions in floating LNG systems affect the uniformity of gas–liquid distribution in heat exchangers. Thermal and hydraulic performances of printed circuit heat exchangers (PCHEs) with straight, zigzag, and trapezoidal channels are investigated under static and rolling conditions. The results reveal that all channels enhance heat transfer near the pseudo-critical point of LNG at a rolling period of 2 s and a rolling amplitude of 15°. The Nusselt number for the PCHE with a zigzag channel increases by 32.2% and 72.5% compared to those with straight and trapezoidal channels. The highest increase in comprehensive performance is obtained for the zigzag channel with an evaluation index of 1.23 under the rolling condition. Compared with under the static condition, the Nusselt number and Fanning friction factor for the zigzag channel increase by 12% and 28% under the rolling condition. The thermal performance is weakened by the nonuniform flow velocity and improved by the enhancement of flow turbulence. The thermal–hydraulic performance increases with the rolling period from 1 s to 3 s and the rolling amplitude from 15° to 45°. The maximum improvement of 65.3% and 97.2% in Nusselt number and Fanning friction factors is observed at a rolling period of 1 s and a rolling amplitude of 45°. The methods to suppress the deterioration of heat transfer in microfluidic channels under rolling conditions are proposed to satisfy the requirement of LNG with low-resistance and high-efficiency microfluidic structure.
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| 25. |
- Yin, Shanshan, et al.
(författare)
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In Situ GISAXS Observation and Large Area Homogeneity Study of Slot-Die Printed PS-b-P4VP and PS-b-P4VP/FeCl3 Thin Films
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:2, s. 3143-3155
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Tidskriftsartikel (refereegranskat)abstract
- Mesoporous hematite (alpha-Fe2O3) thin films with high surface-to-volume ratios show great potential as photoelectrodes or electrochemical electrodes in energy conversion and storage. In the present work, with the assistance of an up-scalable slot-die coating technique, locally highly ordered alpha-Fe2O3 thin films are successfully printed based on the amphiphilic diblock copolymer poly(styrene-b-4-vinylpyridine) (PS-b-P4VP) as a structure-directing agent. Pure PS-b-P4VP films are printed under the same conditions for comparison. The micellization of the diblock copolymer in solution, the film formation process of the printed thin films, the homogeneity of the dry films in the lateral and vertical direction as well as the morphological and compositional information on the calcined hybrid PS-b-P4VP/FeCl3 thin film are investigated. Because of convection during the solvent evaporation process, a similar dimple-type structure of vertically aligned cylindrical PS domains in a P4VP matrix developed for both printed PS-b-P4VP and hybrid PS-b-P4VP/FeCl3 thin films. The coordination effect between the Fe3+ ions and the vinylpyridine groups significantly affects the attachment ability of the P4VP chains to the silicon substrate. Accordingly, distinct feature sizes and homogeneity in the lateral direction, as well as the thicknesses in the perpendicular direction, are demonstrated in the two printed films. By removing the polymer template from the hybrid PS-b-P4VP/FeCl3 film at high temperature, a locally highly ordered mesoporous alpha-Fe2O3 film is obtained. Thus, a facile and up-scalable printing technique is presented for producing homogeneous mesoporous alpha-Fe2O3 thin films.
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| 26. |
- Yin, Shanshan, et al.
(författare)
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Tailored fabrication of quasi-isoporous and double layered alpha-Fe2O3 thin films and their application in photovoltaic devices
- 2023
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Ingår i: Chemical Engineering Journal. - : Elsevier BV. - 1385-8947 .- 1873-3212. ; 455, s. 140135-
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Tidskriftsartikel (refereegranskat)abstract
- A series of α-Fe2O3 thin films with distinct morphologies are prepared via a facile polystyrene-block-polyethylene oxide templated sol–gel method. By tailoring the poor solvent contents and FeCl3-to-polymer weight ratio in the sol–gel solutions, quasi-isoporous α-Fe2O3 thin films with different substructures and thicknesses are obtained. Via a thermal annealing post-treatment, double layered structures are induced by a synergistic dewetting and Oswald ripening effect. Special focus is set on the α-Fe2O3 thin films prepared with no annealing/annealing-medium FeCl3 concentration, as they possess uniform periodic structures, which is suitable to be used as hole blocking modification layer of perovskite solar cells (PSCs). An improved power conversion efficiency (PCE) is obtained when the double layered α-Fe2O3 thin film is applied as the hole blocking modification layer for PSCs. The improved PCE primarily originates from the increased VOC, which probably benefits from the synergistic effect of the suppressed charge carrier recombination at the interfaces, the enhanced light transmittance as well as the superior electron extraction capacity.
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| 27. |
- Zhang, Yunquan, et al.
(författare)
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Parallel Processing Systems for Big Data : A Survey
- 2016
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Ingår i: Proceedings of the IEEE. - : IEEE. - 0018-9219 .- 1558-2256. ; 104:11, s. 2114-2136
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Tidskriftsartikel (refereegranskat)abstract
- The volume, variety, and velocity properties of big data and the valuable information it contains have motivated the investigation of many new parallel data processing systems in addition to the approaches using traditional database management systems (DBMSs). MapReduce pioneered this paradigm change and rapidly became the primary big data processing system for its simplicity, scalability, and fine-grain fault tolerance. However, compared with DBMSs, MapReduce also arouses controversy in processing efficiency, low-level abstraction, and rigid dataflow. Inspired by MapReduce, nowadays the big data systems are blooming. Some of them follow MapReduce's idea, but with more flexible models for general-purpose usage. Some absorb the advantages of DBMSs with higher abstraction. There are also specific systems for certain applications, such as machine learning and stream data processing. To explore new research opportunities and assist users in selecting suitable processing systems for specific applications, this survey paper will give a high-level overview of the existing parallel data processing systems categorized by the data input as batch processing, stream processing, graph processing, and machine learning processing and introduce representative projects in each category. As the pioneer, the original MapReduce system, as well as its active variants and extensions on dataflow, data access, parameter tuning, communication, and energy optimizations will be discussed at first. System benchmarks and open issues for big data processing will also be studied in this survey.
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| 28. |
- Zhou, Wei, et al.
(författare)
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Global Biobank Meta-analysis Initiative : Powering genetic discovery across human disease
- 2022
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Ingår i: Cell Genomics. - : Elsevier. - 2666-979X. ; 2:10
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Tidskriftsartikel (refereegranskat)abstract
- Biobanks facilitate genome-wide association studies (GWASs), which have mapped genomic loci across a range of human diseases and traits. However, most biobanks are primarily composed of individuals of European ancestry. We introduce the Global Biobank Meta-analysis Initiative (GBMI)-a collaborative network of 23 biobanks from 4 continents representing more than 2.2 million consented individuals with genetic data linked to electronic health records. GBMI meta-analyzes summary statistics from GWASs generated using harmonized genotypes and phenotypes from member biobanks for 14 exemplar diseases and endpoints. This strategy validates that GWASs conducted in diverse biobanks can be integrated despite heterogeneity in case definitions, recruitment strategies, and baseline characteristics. This collaborative effort improves GWAS power for diseases, benefits understudied diseases, and improves risk prediction while also enabling the nomination of disease genes and drug candidates by incorporating gene and protein expression data and providing insight into the underlying biology of human diseases and traits.
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