Citation Frequency and the Value of Patented Innovation

Through a survey, economic value estimates were obtained on 962 inventions made in the United States and Germany and on which German patent renewal fees were paid to full-term expiration in 1995. A search of subsequent U.S. and German patents yielded a count of citations to those patents. Patents renewed to full term were significantly more valuable than patents allowed to expire before their full term. The higher an invention's economic value estimate was, the more the relevant patent was subsequently cited. results from two wide-ranging surveys, one in Germany and one in the United States, support Trajtenberg's conclusion that patents with greater economic value are more heavily cited in subsequent patents. Our evidence suggests at least a two-stage escalation of economic values and citation counts. First, patents that are renewed to full term expiration in environments such as Germany with highly progressive annual maintenance fees are more valuable and more highly cited than run-of-the-mill patents allowed to expire before running to full term. Second, within the relatively exclusive cohort of fullterm patents, citation frequency rises with economic value, although with considerable noise in the relationship. The most cited patents turn out to be very valuable indeed, with a single U.S. citation implying on average more than $1 million of economic value. These findings provide new support for research seeking to overcome the limitations of simple patent counts as a measure of innovative contribution by acquiring data on citation frequencies and the number of nations in which patent protection is sought. ZUSAMMENFASSUNG - (Zitationenzahl und der Wert der Patent-Innovation) Durch eine Unternehmensbefragung wurde der Wert von 962 Patenten von US-amerikanischen und deutschen Anmeldern ermittelt, die den Patentschutz durch Zahlung der Verlängerungsgebühren von 1977 bis 1995 in Deutschland aufrechterhalten hatten. Außerdem wurde für diese Patente die Zahl der Zitationen (Bezugnahmen in späteren Patenten) ermittelt. Die bis zur gesetzlichen Laufzeit aufrechterhaltenen Patente wiesen eine signifikant höhere Zahl von Zitationen auf als Patente, die nicht verlängert worden waren. Zwischen der Zahl der Zitationen und dem Wert eines Patentes gibt es einen statistisch signifikanten Zusammenhang, der in dieser Studie näher beschrieben wird.innovation; patent; citation; count data model

Citation Frequency and the Value of Patented Innovation

Through a survey, economic value estimates were obtained on 962 inventions made in the United States and Germany and on which German patent renewal fees were paid to full-term expiration in 1995. A search of subsequent U.S. and German patents yielded a count of citations to those patents. Patents renewed to full term were significantly more valuable than patents allowed to expire before their full term. The higher an invention?s economic value estimate was, the more the relevant patent was subsequently cited. --Innovation,Patent,Citation,Count data model

Citation Frequency and the Value of Patented Innovation

Through a survey, economic value estimates were obtained on 962 inventions made in the United States and Germany and on which German patent renewal fees were paid to full-term expiration in 1995. A search of subsequent U.S. and German patents yielded a count of citations to those patents. Patents renewed to full term were significantly more valuable than patents allowed to expire before their full term. The higher an invention's economic value estimate was, the more the relevant patent was subsequently cited

Diurnal changes in capecitabine clock-controlled metabolism enzymes are responsible for its pharmacokinetics in male mice

The circadian timing system controls absorption, distribution, metabolism, and elimination processes of drug pharmacokinetics over a 24-h period. Exposure of target tissues to the active form of the drug and cytotoxicity display variations depending on the chronopharmacokinetics. For anticancer drugs with narrow therapeutic ranges and dose-limiting side effects, it is particularly important to know the temporal changes in pharmacokinetics. A previous study indicated that pharmacokinetic profile of capecitabine was different depending on dosing time in rat. However, it is not known how such difference is attributed with respect to diurnal rhythm. Therefore, in this study, we evaluated capecitabine-metabolizing enzymes in a diurnal rhythm-dependent manner. To this end, C57BL/6J male mice were orally treated with 500 mg/kg capecitabine at ZT1, ZT7, ZT13, or ZT19. We then determined pharmacokinetics of capecitabine and its metabolites, 5 '-deoxy-5-fluorocytidine (5 ' DFCR), 5 '-deoxy-5-fluorouridine (5 ' DFUR), 5-fluorouracil (5-FU), in plasma and liver. Results revealed that plasma C-max and AUC(0-6h) (area under the plasma concentration-time curve from 0 to 6 h) values of capecitabine, 5 ' DFUR, and 5-FU were higher during the rest phase (ZT1 and ZT7) than the activity phase (ZT13 and ZT19) (p < 0.05). Similarly, C-max and AUC(0-6h) values of 5 ' DFUR and 5-FU in liver were higher during the rest phase than activity phase (p < 0.05), while there was no significant difference in liver concentrations of capecitabine and 5 ' DFCR. We determined the level of the enzymes responsible for the conversion of capecitabine and its metabolites at each ZT. Results indicated the levels of carboxylesterase 1 and 2, cytidine deaminase, uridine phosphorylase 2, and dihydropyrimidine dehydrogenase (p < 0.05) are being rhythmically regulated and, in turn, attributed different pharmacokinetics profiles of capecitabine and its metabolism. This study highlights the importance of capecitabine administration time to increase the efficacy with minimum adverse effects.Istanbul Universit

Patent Citation Cycles

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