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We narrowed to 1,042 results for: URE

Showing: 211 - 240 of 1042 results
  1. Twenty Years of Sharing: Addgene's Viral Vector Service

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    Blog Post
    ...growing in requests faster than jGCaMP7 (Figure 5B).   Figure 5: A) GCaMP6, jGCaMP7, and jGCaMP8 viral...setup. Teams across Addgene have worked hard to ensure that the service has grown steadily, helped by ...our catalog had grown to 879 viral catalog items (Figure 1). The service caught on quickly in the scientific...distributed over 100,000 viral vector preps!   Figure 1: A) Cumulative AAV preps available in the Addgene... they’re delivering their payload to.   Figure 2: Numbers of AAV tools, by category, available...respectively, by substrates, light, or engineered ligands (Figure 2). Biosensors, which include calcium and voltage...explain why they are the most commonly requested (Figure 3). Over 400 biosensors were distributed in 2023...
  2. AAV Titers: Where Do They Come From And What Do They Mean?

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    Blog Post
    ...preparations are genome-containing (Figure 1).    Figure 1: Electron micrograph of an Addgene... by the temperature parameters. For example, we found that changing the annealing temperature of the PCR...viral vector solution, and generally these methods measure different characteristics of the solution. These... containing viral genomes. Physical titers are measured by quantifying the concentration of viral genomes... report the physical titer of a viral solution (Figure 2). Because physical titers are used for dosing...values mean and how they can be compared.   Figure 2: Label that comes on Addgene’s AAV aliquots. ...circled in red) report physical titer, which is measured by qPCR.   Physical titer is typically calculated...
  3. Neuronal labeling with Spaghetti Monster

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    Blog Post
    ...neuronal sub-cellular structures GFP is limited in its ability to label subcellular structures in the CNS. GFP...connections (Shepherd, 2004). Understanding the structure and function of these neural circuits is essential...experiments and visualize numerous molecules or structures at once (Shaner, 2007). In contrast to epitope...for the cells and affects the labeling of small structures like neurites. Like epitope tags, low FP expression...church of the Flying Spaghetti Monster; the smFP structure resembles images of the deity (see comparison ...processes. In contrast, smFPs can label fine neuronal structures with high fidelity and at lower concentrations...GFP. smFPs enable better labeling of these fine structures through their multiple, high-affinity binding...
  4. Deep Dive: Statistical Tests (Comparisons)

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    Blog Post
    ... of temperature on total crop production and the production window. A two-way MANOVA could measure the..., you could test the impact of temperature, humidity, sunlight exposure time, and watering volume on total...power. Not sure if your data meets the assumptions of parametric tests? If you aren’t sure if your variance...outliers or data spread within those data sets. Measures of dispersion – standard deviation/error, variance...in a certain direction (i.e., you just want to measure if a sample is greater than a control), then a ...variable. A two-way ANOVA could test the effect of temperature and humidity on an outcome such as total crop... one-way ANOVA can test either the effect of temperature or humidity on crop production.   MANOVA The ...
  5. Sequencing Options for CRISPR Genotyping

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    Blog Post
    ... Figure 1: Schematic representations of the indicated unbiased genotyping options. Figure reproduced...other elements, including those relating to DNA structure (e.g. epigenetic modification, bulges) that may...conventional algorithms may not provide a full picture of the impact of CRISPR editing in the model cell...negatives Combining sequencing techniques can ensure validated experiments Unbiased detection methods...sequencing and in silico prediction should give a broad picture of all possible editing events in the genome; from...induced by CRISPR-Cas nucleases in human cells." Nature biotechnology 31.9 (2013): 822-826. PubMed PMID...reveals RNA-programmed Cas9 nuclease specificity." Nature biotechnology 31.9 (2013): 839-843. PubMed PMID...
  6. OCaMP: A New Calcium Indicator for Neural Imaging

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    Blog Post
    ...fluorescent protein mOrange2 (Figure 2). Figure 2: OCaMP structure and mechanism of action. Reproduced...brightness, ∆F/F0, or signal-to-noise ratio (Figure 3). Figure 3: One- and two-photon excitation and ... Figure 4: Calcium titration curves for OCaMP and various red and yellow GECIs measured with soluble...lasers available in your microscope setup. Figure 1: Excitation (dotted) and emission (solid) spectra...indicators spanning nearly the entire visible spectrum (Figure 1). The GCaMP series (e.g., jGCaMP8) remains the... yellow GECIs, OCaMP shows: Higher ΔF/F0 (the measure of signal change during calcium events), Greater...a CC-BY-NC-ND 4.0 International license. Figure 5: A) Simultaneous fluorescence (upper trace) and...
  7. Flow Cytometry Readouts: Yes, No, and Everything in Between

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    Blog Post
    ...downregulation. Figure 3 shows a histogram for a yes-no dot plot, like the one shown in Figure 1.  ...populations in the histogram plot in Figure 4 compared to the dot plot in Figure 2. Quantification using MFI makes...Before you read out your plots, you’ll want to make sure you’ve also adjusted voltage and compensated your...adjusting voltage: During data acquisition, make sure that the signal for the positive population is no...should overlap with the negative control population (Figure 1). Based on where the GFP- population ends, you... the total cells present in the gate.   Figure 1: Example of yes-no flow plot of the (negative...expression, low expression, and everything in between (Figure 2). These smears tend to occur when you are looking...
  8. Pooled CRISPR Libraries Offer Genome-Wide Control for Large-Scale Functional Screens

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    Blog Post
    ...Nishimasu H, Nureki O, Zhang F. Nature. 2015 Jan 29;517(7536):583-8. doi: 10.1038/nature14136. Epub 2014...Cas9’s crystal structure. “I thought maybe we could use information from the structure to guide and improve...technology. These libraries are lentiviral in nature, so please ensure that you are equipped and authorized to...genes, it is not possible to test each one and make sure it’s working. You can only do that screen with a... the SAM pooled library In a paper published in Nature in December, Konermann and her colleagues in Feng...-scale, knockout screening). As the Zhang lab's Nature paper reports, “Here we have shown that the SAM...Therapeutic uses in humans are also on the table. “In the future, there is potential there,” he says. "We have to...
  9. Plasmid Preps: Different Purity, Different Quantities, Different Uses

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    Blog Post
    ...the purification procedure. Good indicators of DNA purity are the absorbance measurements at 230, 260, and...same. Before purifying a plasmid from a bacterial culture, it is important to consider your experiment.  ...Cloning grade DNA Transfection grade DNA Figure 1: Transformation introduces transformation grade...range). It can be extracted from small bacterial cultures (i.e. 2-3 ml) with or without commercially available...and DNA for transformation doesn’t need to be as pure as for other uses.   Cloning grade DNA Molecular...also dictate the required sizes of the bacterial cultures and commercial kits you will adopt for the extraction... cloning it is important that the preparation is pure from other nucleic acids (genomic DNA and RNA), ...
  10. Live and Let Dye: Self-Labeling Protein Tags

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    Blog Post
    ...applications.   Figure 1: Live-cell labeling strategies. The green structure represents a fluorophore... end up linked to whatever molecule you choose (Figure 1). Just express the fusion protein and add a specific...fluorophore or other useful ligand, gray structure is the protein of interest, and black is the fusion tag ...-tag construct can help you better detect dim structures or low levels of expression with the same imaging...super-resolution or single-molecule techniques.   Figure 2: Two-color super-resolution imaging of ER and... enables applications like multi-color imaging (Figure 2). If you’re working with purified proteins in...colors depending on the needs of your experiment (Figure 3). And using self-labeling tags makes updating...
  11. Fluorescent Proteins 101: Photoactivatable Fluorescent Proteins

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    Blog Post
    ...unique changes in their spectral properties upon exposure to a specific wavelength of light. PA-FPs can ...fluorescence, to a brighter fluorescent state by exposure to a specific wavelength of light. The switch ...switches from green to red fluorescence. mEosFP exposure to UV light causes an irreversible cleavage near...formation of mEosFP’s chromophore requires a temperature below 30°C and this is not ideal for experiments...emission of green fluorescence, but then further exposure to blue light also inactivates the chromophore...state. Dronpa can be reversibly reactivated by exposure to UV light. The fact that blue light both activates...photons are being emitted, making it easier to capture a clear image above background. The majority of...
  12. A Look at Addgene's QC Process

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    Blog Post
    ... to ensure all plasmids pass our high-quality standards and contain the expected plasmid features.  ...based on SnapGene’s “Common Feature” library — with some additional features added by the QC team — and...the plasmid to ensure our assembly result is accurate The gene/insert or any major feature highlighted by...Nobody’s perfect! This is a platitude I’m sure we have all heard. It’s a truth that extends to both people...optimizing experiments, to false conclusions.  Figure 1. Potential points where DNA errors can be introduced... Figure 2. Addgene’s basic QC process. Created with BioRender.com. Once Addgene receives deposited...resolving a variety of QC issues. This process ensures that any potential sequence discrepancies can be...
  13. Viral Vectors 101: Virus Safety

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    Blog Post
    ... alert the day of the procedure. Mice move much more quickly than cell cultures do, and tired researchers... some nerves. Following safety procedures and practicing safety culture, however, can let you work with...risks and how to minimize them. Built-in safety features   When viruses were first being engineered as ...still enter (and thus infect) cells, this safety feature prevents the virus from replicating and spreading... including yourself as the researcher.   Figure 1: Separation of retroviral packaging components...precautions to take, and if something does happen, ensure you can receive appropriate treatment and/or monitoring...monitoring. Virus-specific concerns   In nature, some viruses are more dangerous than others, and the...
  14. Antibodies 101: Flow Compensation

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    Blog Post
    ...present in the sample (APC in the case of Figure 1). In Figure 1A, the population needs to be shifted towards.... Let's look at an experimental example in Figure 2. Figure 2A shows the sample prior to compensation....the populations move, as in Figure 2, following compensation. Figure 3: Flow plot for a double positive... a compensation value between the two channels (Figure 1A). Applying compensation means you are telling...values later in your analysis, unlike voltages.  Figure 1A shows a single-color APC control, with APC and... a straight line and are only positive for APC (Figure 1B). For single-color samples, you can only change...would decrease the compensation value.   Figure 1: Compensation example with single color control...
  15. Polymerase Chain Reaction Overview and Applications

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    Blog Post
    ...also stable at this temperature and can bind to the primers.  Extension- The temperature is then raised slightly...slightly to Taq polymerase’s ideal temperature (70-75oC). At this temperature Taq polymerase can synthesize...and the use of a fluorometer feature built into the thermocycler to measure that fluorescent output. With...resistant enzyme that can withstand changes in temperature. Taq was first identified in the late 1960s during...separation of the two DNA strands.  Annealing- The temperature is then dropped to a range in which the forward...forward and reverse primers are stable. At this temperature the primers can anneal to the single stranded...the target DNA quickly and accurately.  Figure 1: Steps in PCR reaction   This process of ...
  16. Early Career Researcher Toolbox: Free Tools for Making Scientific Graphics

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    Blog Post
    ...your own figures Google Drawings Google Drawings is similar to using PowerPoint to draw figures. It’s part...useful for drawing figures with lots of elements. It took some playing around to figure out all the settings...project my team & I have poured our hearts into for 2 yrs) has 200K+ figures by 95K+ scientists 👨🏽‍🔬...when writing posts. Since then I’ve realized my figures are just as important, if not more important, than...drawing tools, so it’s harder to draw intricate figures, like a brain or a mouse. Vectr Vectr is like a... Vectr to be fairly intuitive and I was making figures quickly. Inkscape Inkscape is the most similar...Illustrator out of the three options for drawing your own figure discussed in this post. It’s open source and available...
  17. The CRISPR Software Matchmaker: A New Tool for Choosing the Best CRISPR Software for Your Needs

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    Blog Post
    ...design goals. Examples:  “feature aware”, “SNP aware”, “secondary structure aware”, and “microhomology...collective utility, it’s easy to fault the lack of features in a single application. The question is then,... solve, and finally how we might proceed in the future. When we think of designing experiments using CRISPR...have broken down the tools into the individual features that make each tool unique. The CRISPR Software...Software Matchmaker is composed of these features and enables you to select the tool(s) based on your project...advanced functionality, it seems these kinds of features are delegated to other more suitable software ... removing repetitive tasks and/or by providing features to help with the post-design process such as primer...
  18. FLEx Technology and Optogenetics: Flipping the switch on gene expression with high spatial and temporal resolution

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    Blog Post
    ...activates halorhodopsins to silence neuronal activity (Figure 1) (Wiegert et al., 2017). How to get an opsin...into the correct orientation to be transcribed (Figure 2) (Sharma and Zhu, 2014). How does FLEx enable...promoter only in specific neuronal cells. FLEx ensures, therefore, spatial accuracy and strong opsin expression... functional topography of the neural circuit architecture of the brain regions associated with motivated...on developmental biology at the École Normale Supérieure de Lyon. Her love for educational science led...genetically targeted optical control of neural activity." Nature neuroscience 8.9 (2005): 1263. PubMed PMID: 16116447...: PMC2820367. Deisseroth, Karl. "Optogenetics." Nature methods 8.1 (2011): 26. PubMed PMID: 21191368. ...
  19. QC Sequencing Technologies at Addgene

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    Blog Post
    ...short-read sequencing are highlighted in Figure 2. Figure 2: Overview of short-read sequencing technology...pnas.74.12.5463  Shendure, J., & Ji, H. (2008). Next-generation DNA sequencing. Nature Biotechnology, 26... that’s not the only technology Addgene uses to ensure accuracy of deposited plasmids. To resolve QC issues...recognized and recorded as a DNA strand is synthesized (Figure 1). Sanger sequencing requires four separate reactions... “trace” file to determine the sequence. Figure 1: Overview of Sanger sequencing technology. Created...by synthesis, but modifies the original Sanger procedure to improve throughput by increasing the number...puzzle pieces together. Once they have the full picture of the puzzle, the QC team compares it to the plasmid...
  20. Hot Plasmids - November 2023

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    Blog Post
    ... and in vitro applications.   Figure 2: Modular features of DIRECTED particles where the fusion...-the-art. PE6b was very efficient for short, unstructured templates and significantly reduced undesired...efficient at complex edits, such as long or highly structured templates. Cas9 variants PE6e–g often had even...varied depending on the specific edit.   Figure 1: Choosing the best PE6 variant for your application...type-specific delivery by modular envelope design. Nature Communications, 14(1), 5141. https://doi.org/10.1038...therefore been trafficked between locations). Figure 3: A) LOV-Turbo becomes active when illuminated... control of proximity labeling in living cells. Nature Methods, 20(6), 908–917. doi: 10.1038/s41592-023...
  21. Plasmids 101: Codon usage bias

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    ...codon optimality reveals hidden signatures of cotranslational folding." Nature structural & molecular biology20.2...but some possible reasons include: Metabolic pressures - it takes cellular resources to produce tRNAs...Protein folding - If a protein is encoded by a mixture of codons with highly and poorly charged tRNAs,...codons are associated with specific secondary structures in 10 closely related yeast strains. Adaptation...properly. You might then think, “Okay, I’ll just make sure the abundances of the codons I choose for the host...Angov et al., 2008), but there are still many more features to consider when designing a full gene. A non-...Restriction sites Sequences prone to create secondary structures in RNA transcripts Effects on transcription (...
  22. 15 Hot Plasmids from 2017

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    Blog Post
    ...repository, but be sure to let us know if you'd like to write about your plasmids in a future blog post. No...found at Addgene and in Figure S12 of the publication. Agudelo D, et al. Nature Methods. 2017. PubMed ...Rees H, et al. Nature Communications. 2017. PubMed PMID: 28585549 Kim Y, et al. Nature Biotechnology. ...GABA-ergic interneurons here. Dimidschstein J, et al. Nature Neuroscience. 2016. PubMed PMID: 27798629 Listen...Find PhoCl plasmids at Addgene. Zhang W, et al. Nature Methods. 2017. PubMed PMID: 28288123 Listen to...used as tools to learn about the influence of structure on an FP’s properties. pBAD-LSSmCherry1 is a long... Plasmid ID Plasmid Name Cas9 Variant Speacial Features 85169  pJL-SaBE3  SaCas9 (NNGRRT)    85170...
  23. Optogenetics + CRISPR, Using Light to Control Genome Editing

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    Blog Post
    ...CRY2PHR-activator fusion floats freely, depicted in the figure below. Once triggered by blue light, the CRY2 and...31X. By using a slit pattern during blue light exposure (470nm), the researchers showed that expression...created a photoactive Cas9 tool, as shown in the figure below. Their most successful design utilized Magnet...on and off. As one might expect from the modular nature of Cas9, Nihongaki et al. showed that it was possible...reach deeper tissues. Additionally, high intensity exposure can cause DNA damage. Far-red light, however, ...to create photoswitchable spCas9, dCas9, and S. aureus Cas9 (saCas9) proteins, showing the versatility... variant of AcrIIA4 (CASANOVA). As shown in the figure below, in the absence of light, Cas9 is bound by...
  24. Illuminating Choices: A Guide to Selecting Fluorescent Dyes and Ligands

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    Blog Post
    ... of fluorescent dyes/ligands Figure 1: Example structures of fluorophores, fluorescent dyes, and...visualization of both organic tissues and cell cultures, opening biological interiors to many inquisitive... and fluorescent ligands. Figure created with BioRender.com. Fluorescence refers to the emission ...Fluorescent dyes and ligands vary in their chemical structure, leading to differences in their excitation and...ability to retain fluorescent intensity during exposure to light, is another factor to consider. If your...your application requires longer periods of exposure, you’ll want a more photostable fluorophore. Factors...recruitment to receptors, indicating their agonistic nature. The potency and efficacy of these ligands can ...
  25. Antibodies 101: Beyond Surface Labeling

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    Blog Post
    ...a separate fix/perm cytosolic procedure in that case.     Figure 3: For intracellular labeling...antibody through the biotin-streptavidin interaction (Figure 1a). This interaction brings the fluorophore in...plasmids and biotin plasmids at Addgene!     Figure 1: Indirect detection of target markers can be ...(“anti-rabbit”) region of the primary antibody (Figure 1b). As above, the advantage of this system is ...which would label everything but the CD8+ T cells (Figure 2). Even better, we can use the same fluorophore... gating on the negative population.     Figure 2: Dump gating labels all unwanted cell lineages...membrane but inside the cell. Due to their chemical nature, antibodies cannot penetrate the cell membrane;...
  26. SARS-CoV-2/COVID-19 Detection Methods Based on CRISPR/Cas

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    Blog Post
    ...guest bloggers Shravanti Surest from Iowa State University. Shravanti Suresh is a PhD candidate who investigates...This post was contributed by Shravanti Suresh from Iowa State University. Since its appearance, SARS-...19 and some serological tests to determine past exposure. However, the limited availability of reagents... turn to other technologies like CRISPR. Figure 1: An overview of the general schematic of CRISPR...with streptavidin, the lateral flow strip first captures the streptavidin portion of the probe via biotin...probe that is cut will continue to flow and be captured by an antibody further along on the strip. Highlights...Isothermal amplification is done at one constant temperature, eliminating the need for thermocyclers. This...
  27. Antibodies 101: Introduction to Immunofluorescence

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    Blog Post
    ...primary is conjugated to a fluorophore (Figure 1).   Figure 1: Comparison between how direct immunofluorescence...confocal   Figure 2: High-level overview of an indirect immunofluorescence procedure with key considerations...within a cell,” “Does this disease change the architecture of my cells,” or “How does this mutation impact...non-fluorescent visualization methods. Stay tuned for a future blog post to learn more about these techniques!.... For this strategy to work, it is important to ensure that you are using secondaries with fluorophores...divided into the several steps outlined below and in Figure 2. For a deeper dive into the steps and techniques...involve multiple smaller steps that all help to ensure that antibodies can access their target and that...
  28. Savvy Advocates Needed to Navigate a Scientific Enterprise in Flux

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    ...Symposium and Workshop, organized by Future of Research, Academics for the Future of Science, and the MIT Graduate... More information can be found at http://futureofresearch.org/advocating-for-science-boston-2016/. Sign...Science Symposium Boston 2016 Changes since the Future of Research Symposia Ongoing challenges facing...et al, PNAS 2014; Taylor, eLife, 2016). Several Future of Research (FoR) symposia held across the USA ...science to date. Advocacy opportunities for the future No matter your opinion on these changes, it is ...institutional responses to the FLSA ruling. Similarly, from purely a salary perspective, while this is a move in the...For those advocating in this area, keeping the pressure on for further increases will be challenging, ...
  29. Exploring Applications of the Bioluminescent HiBiT Tag

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    ...disrupt normal cell biology and make it hard to capture true protein behavior. Traditional epitope knock-ins...Together, these limitations create challenges for measurements needed to move discoveries from the lab bench...reconstitutes a fully functional luciferase enzyme (Figure 1). Addition of substrate generates a proportionate...research questions before creating knock-ins.  Figure 1: Schematic of HiBiT tagging technology.   ...autofluorescence from the plates or media, which can obscure weak signals; photobleaching from the excitation...more than substrate addition and a simple add-mix-measure method. NanoBiT® luciferase activity is compatible...letting you track endogenous protein activity and measure responses to therapeutics in real time. Let's take...
  30. Hot Plasmids: Spring 2025

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    ...Glypican Collection here! Figure 3: General glypican domain structure. Glypicans are proteoglycans ... no UTR sequence added to the genome (Figure 4). Figure 4: STITCHR consists of a nicking Cas9 ... FOS gene promoter and the MYC locus (Figure 5). Figure 5: TurboCas protein labeling compared ...synapses and deep-brain fiber photometry.  Figure 1: Characterization of iGluSnFR4 in mice. A) Scheme...choice. After hearing about researchers' favorite features and limitations of existing backbones, we're excited...viral generation and stable cell line creation (Figure 2). Looking for more? Explore our empty and EGFP... own Lentiviral backbone plasmids here! Figure 2: Addgene cloned EGFP into pAG Lenti CMV N-HA ...
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