68 research outputs found
Comment on "Delayed luminescence of biological systems in terms of coherent states" [Phys. Lett. A 293 (2002) 93]
Popp and Yan [F. A. Popp, Y. Yan, Phys. Lett. A 293 (2002) 93] proposed a
model for delayed luminescence based on a single time-dependent coherent state.
We show that the general solution of their model corresponds to a luminescence
that is a linear function of time. Therefore, their model is not compatible
with any measured delayed luminescence. Moreover, the functions that they use
to describe the oscillatory behaviour of delayed luminescence are not solutions
of the coupling equations to be solved.Comment: 2 pages, no figur
THE IMPACT OF E-LEARNING ON UNIVERSITY STUDENTS' ACADEMIC ACHIEVEMENT AND CREATIVITY
Research on the efficacy of ICT-based teaching methods in improving generic skills in addition to content skills among future workforce is increasing.  Accordingly, this study investigates the impact of e-learning on creativity and content knowledge of chemistry students at the Payame Noor University of Hamedan, Iran. The study used the pre-test/post-test experimental design with a control group. The statistical population of the study included was 100 pure chemistry students who were following two separate classes. Forty students were selected from this group who placed in the experimental group (n = 20) and the control group (n = 20). Two instruments were used for data collection; a specifically developed test on the Introduction to Chemistry course and the Abedi Inventory for assessing creativity. Results of data analysis using the independent t-test (aided by SPSS) demonstrated statistically significantly higher scores for the experimental group on measured variables, knowledge and creativity. Therefore, it is concluded that e-learning is effective for knowledge and creativity acquisitions among chemistry students and the greater e-learning opportunities should be provided for wider audiences
A Quantum-mechanical description of ion motion within the confining potentials of voltage gated ion channels
Voltage gated channel proteins cooperate in the transmission of membrane
potentials between nerve cells. With the recent progress in atomic-scaled
biological chemistry it has now become established that these channel proteins
provide highly correlated atomic environments that may maintain electronic
coherences even at warm temperatures. Here we demonstrate solutions of the
Schr\"{o}dinger equation that represent the interaction of a single potassium
ion within the surrounding carbonyl dipoles in the Berneche-Roux model of the
bacterial \textit{KcsA} model channel. We show that, depending on the
surrounding carbonyl derived potentials, alkali ions can become highly
delocalized in the filter region of proteins at warm temperatures. We provide
estimations about the temporal evolution of the kinetic energy of ions
depending on their interaction with other ions, their location within the
oxygen cage of the proteins filter region and depending on different
oscillation frequencies of the surrounding carbonyl groups. Our results provide
the first evidence that quantum mechanical properties are needed to explain a
fundamental biological property such as ion-selectivity in trans-membrane
ion-currents and the effect on gating kinetics and shaping of classical
conductances in electrically excitable cells.Comment: 12 pages, 8 figure
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