Thixotropic gel is an inert (nonreacting) synthetic substance in the bottom of certain tubes. When a specimen in a gel tube is centrifuged the gel undergoes a change in viscosity and moves to a position between the cells and the serum or plasma, forming a physical barrier between them. This separation prevents the cells from continuing to metabolize substances such as glucose in the serum or plasma.
Placement of Citations. 1  Place a citation as close to the quoted or paraphrased material as possible without disrupting the sentence. 2  When material from one source and the same page numbers is used throughout a paragraph, use one citation at the end of the paragraph rather than a citation at the end of each sentence.
Google Scholar Citations. Google Scholar Citations provide a simple way for authors to keep track of citations to their articles. You can check who is citing your publications, graph citations over time, and compute several citation metrics. You can also make your profile public, so that it may appear in Google Scholar results when people search for your name, e.g., richard feynman.