PubMedChronology (PMC) is an app to visualize the chronology of subject terms based on PubMed queries. The number of hits for certain search terms is displayed as a graph in dependence of a range of year dates.

The app is useful to analyze trends in publication topics to elucidate historical developments and/or compare importance of subjects over time.

It is possible to export the data for generation of customized graphs.
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Main Interface

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Main Interface

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Data Export

In the line graph view it possible to save the data and the graph. The saved data is stored in the document directory. This directory can be accessed via iTunes (Guide). The data can be used to generate custom graphs on your desktop computer (e.g. iWork or Office). Three files will be saved: Values for subject term A (.txt), values for subject term B (.txt) and an image of the graph (.png).
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Saved data can be accessed via iTunes.


Approximate search times (WiFi connection):
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Below are examples to demonstrate the generation of customized graphs based on data generated with PubMedChronology.
Various Diseases
The graph shows that cancer is a main research topic.
Organ Transplantation
Historical development in organ transplantation. Influence of Cyclosporin A. The values for regenerative medicine are depicted on a separated axis.
Comparison between genomics and proteomics. Genomics is approx. 10 years ahead in technological development.
Technological Shift
Demonstration of a shift in technology.
Performance of various pharmaceutical companies
The figure depicts the performance of various pharmaceutical companies between 1979 and 2009.
(black,bold) This company (Pfizer) has the most frequent occurrences in PubMed. It shows an steady increase over the entire period.
(dark and light gray) These companies show a lower level in comparison to ten years ago, but now a more show constant performance.
(colors) These companies show a permanent decrease in performance since 2003.

(The performance is defined as occurrences of company names in publications)