At the Biological Modeling and Simulation Frontier

We provide a rationale for and describe examples of synthetic modeling and simulation (M&S) of biological systems. We explain how synthetic methods are distinct from familiar inductive methods. Synthetic M&S is a means to better understand the mechanisms that generate normal and disease-related phenomena observed in research, and how compounds of interest interact with them to alter phenomena. An objective is to build better, working hypotheses of plausible mechanisms. A synthetic model is an extant hypothesis: execution produces an observable mechanism and phenomena. Mobile objects representing compounds carry information enabling components to distinguish between them and react accordingly when different compounds are studied simultaneously. We argue that the familiar inductive approaches contribute to the general inefficiencies being experienced by pharmaceutical R&D, and that use of synthetic approaches accelerates and improves R&D decision-making and thus the drug development process. A reason is that synthetic models encourage and facilitate abductive scientific reasoning, a primary means of knowledge creation and creative cognition. When synthetic models are executed, we observe different aspects of knowledge in action from different perspectives. These models can be tuned to reflect differences in experimental conditions and individuals, making translational research more concrete while moving us closer to personalized medicine

Comparative performances of birnessite and cryptomelane MnO as electrode material in neutral aqueous lithium salt for supercapacitor application

International audienceNa-doped Birnessite-type manganese oxide (δ-MnO2) has been synthesized using the chemical method and characterized through X-ray diffraction and SEM, showing the lamellar structure and high crystal structure. A comparative study of the electrochemical performances of this material with those of the commercial Cryptomelane-type MnO2 has then been undertaken in ten neutral aqueous electrolytes for supercapacitor applications. Aqueous electrolytes, containing a lithium salt, LiX (where X = SO42-, NO3-, CH3CO2-, CH3SO3-, ClO4-, C7H15CO2-, TFSI-, Beti-, BOB-, or Lact-), have been first prepared under neutral pH conditions to reach the salt concentration, providing the maximum in conductivity. Their transport properties are then investigated through conductivities, viscosities, and self-diffusion coefficient measurements. Second, the thermal behaviors of these electrolytic aqueous solutions are then evaluated by using a differential scanning calorimeter from (213.15 to 473.15) K in order to access their liquid range temperatures. Cyclic voltammograms (CV) in three electrode configurations are thereafter investigated using Na Birnessite and Cryptomelane as working electrode material from (−0.05 to 1.5) V versus Ag/AgCl at various sweep rates from (2 to 100) mV*s-1. According to anion nature/structure and manganese oxide material type, different CV responses are observed, presenting a pure capacitive profile for Beti- or C6H13CO2- and an additional pseudocapacitive signal for the smallest anions, such as ClO4- and NO3-. The capacitances, energies, and efficiencies are finally calculated. These results indicate clearly that electrolytes based on a mineral lithium salt under neutral pH condition and high salt concentration (up to 5 mol*L-1) have better electrochemical performances than organic ones, up to 1.4 V with good material stability and capacity retention. The relationship between transport properties, electrostatic and steric hindrance considerations of hydrated ions, and their electrochemical performances is discussed in order to understand further the lithium intercalation-deintercalation processes in the lamellar or tunnel structure of investigated MnO2