Parts Per Million
Parts Per Million - Related Videos
09:42
Unraveling Entropic Rate Acceleration Induced by Solvent Dynamics in Membrane Enzymes
0 Views •
Cited by 17 •
2016
Channels for the transportation of water molecules in enzymes influence active site solvation and catalysis. Herein we present a protocol for the engineering of these additional catalytic motifs based on in silico computer modeling and experiments. This will enhance our understanding of the influence of solvent dynamics on enzyme catalysis.
05:54
Transplantation into the Anterior Chamber of the Eye for Longitudinal, Non-invasive In vivo Imaging with Single-cell Resolution in Real-time
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Cited by 31 •
2013
A new approach combining intraocular transplantation and confocal microscopy enables longitudinal, non-invasive real-time imaging with single-cell resolution within grafted tissues in vivo. We demonstrate how to transplant pancreatic islets into the anterior chamber of the mouse eye.
08:59
Looking for Driver Pathways of Acquired Resistance to Targeted Therapy: Drug Resistant Subclone Generation and Sensitivity Restoring by Gene Knock-down
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Cited by 1 •
2017
This is a time- and cost-effective in vitro protocol investigating the mechanisms of acquired resistance to targeted therapeutic agents, which is a highly unmet medical need in cancer management.
08:12
Detection of a Circulating MicroRNA Custom Panel in Patients with Metastatic Colorectal Cancer
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Cited by 2 •
2019
We present a protocol to evaluate the expression levels of circulating microRNA (miRNAs) in plasma samples from cancer patients. In particular, we used a commercially available kit for circulating miRNA extraction and reverse transcription. Finally, we analyzed a panel of 24 selected miRNAs using real-time pre-spotted probe custom plates.
05:27
In Vivo Imaging of Liver Spheroids Engrafted in the Anterior Chamber of the Mouse Eye
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2024
Here, we describe a platform that allows noninvasive in vivo imaging of liver spheroids engrafted in the anterior chamber of the mouse eye. The workflow spans from generating spheroids from primary liver cells to transplantation into the mouse eye and in vivo imaging at cellular resolution by confocal microscopy.
FAQs
The same numerical ppm value can represent different quantities if it is based on mass, volume, a solution, or a sample. Chemistry reports therefore need to identify what the measured amount is relative to. This clarification prevents misleading comparisons and allows analytical, environmental, or quality-control results to be interpreted consistently.
The approximation applies to dilute aqueous solutions, where ppm commonly corresponds numerically to milligrams of solute per liter of solution. It should not be treated as a universal conversion because the relationship depends on the stated mass or volume basis and the nature of the sample. Reporting the basis preserves the measurement’s meaning.
They should verify that both values use the same reference basis and describe comparable materials, such as solutions or samples. A ppm result tied to a volume basis should not be interpreted as though it were mass-based without additional information. This check is especially important when evaluating contaminants, dissolved ions, or additives from different measurements.
A useful report identifies the substance measured, the solution or sample examined, and the mass or volume basis used for the concentration. If the result comes from a dilute aqueous solution, the report may also state the corresponding milligrams-per-liter approximation, while making clear that it is an approximation rather than an unrestricted conversion.
Environmental measurements use ppm to describe trace contaminants, dissolved ions, and atmospheric gases in samples or monitored media. The unit allows small concentrations to be recorded in a compact form for analytical measurement and comparison. Interpreting the result still requires attention to whether the reported basis concerns the sample, solution, mass, or volume.
In quality control, ppm can express the concentration of trace additives or unwanted contaminants in a material or solution. In exposure assessment, it provides a way to report small amounts of chemical substances detected in relevant samples or atmospheric measurements. These uses help connect analytical results with monitoring decisions, provided the concentration basis is clearly stated.