Long-term in vitro 3D hydrogel co-culture model of inflammatory bowel disease

The in vitro study of the pathogenesis of inflammatory bowel disease (IBD) requires a cell model which closely reflects the characteristics of the in vivo intestinal epithelium. This study aimed to investigate the application of L-pNIPAM hydrogel as a scaffold to develop a long-term 3D co-culture model of Caco-2 and HT29-MTX cells under conditions analogous to inflammation, to determine its potential use in studying IBD. Monocultures and co-cultures were layered on L-pNIPAM hydrogel scaffolds and maintained under dynamic culture conditions for up to 12 weeks. Treatments with IL-1β, TNFα, and hypoxia for 1 week were used to create an inflammatory environment. Following prolonged culture, the metabolic activity of Caco-2 monoculture and 90% Caco-2/10% HT29-MTX co-cultures on L-pNIPAM hydrogels were increased, and finger-like structures, similar in appearance to villi were observed. Following treatment with IL-1β, TNFα and hypoxia, ALP and ZO-1 were decreased, MUC2 increased, and MUC5AC remained unchanged. ADAMTS1 was increased in response to hypoxia. Caspase 3 expression was increased in response to TNFα and hypoxic conditions. In conclusion, L-pNIPAM hydrogel supported long-term co-culture within a 3D model. Furthermore, stimulation with factors seen during inflammation recapitulated features seen during IBD

Signs of the rates in the Lindblad master equations can always be arbitrarily determined

Determining the Markovianity and non-Markovianity of a quantum process is a critical problem in the theory of open quantum systems, as their behaviors differ significantly in terms of complexity. It is well recognized that a quantum process is Markovian if and only if the quantum master equation can be written in the standard Lindblad form with all rates nonnegative for all time. However, here we present a striking result that \textit{any} finite-dimensional open quantum system dynamics can be described by a quantum master equation in the Lindblad form with all rates nonnegative for all time. In fact, it can be shown that one can arbitrarily decide the sign of the rates in any case at any time interval. Note that here we take an unconventional approach where the quantum master equation we construct will in general be state-dependent, which means that the Hamiltonian, jump operators and rates will all depend on the current state of the density matrix $\rho(t)$. Our findings raise serious questions on the current criterion in determining Markovianity and non-Markovianity in open quantum system dynamics.Comment: 5 page

Quantum State Driving along Arbitrary Trajectories

Starting with the quantum brachistochrone problem of the infinitesimal form, we solve the minimal time and corresponding time-dependent Hamiltonian to drive a pure quantum state with limited resources along arbitrary pre-assigned trajectories. It is also shown that out of all possible trajectories, with limited resources, which are physically accessible and which are not. The solution is then generalized to the mixed quantum state cases, and applied to trajectories parameterized by single or multiple parameters with discrete or continuous spectrum. We then compare the solution to that of the counterdiabatic driving, and show how the Berry phase is directly involved in both driving processes.Comment: 7 pages, 3 figure

Describing the Wave Function Collapse Process with a State-dependent Hamiltonian

It is well-known that quantum mechanics admits two distinct evolutions: the unitary evolution, which is deterministic and well described by the Schr\"{o}dinger equation, and the collapse of the wave function, which is probablistic, generally non-unitary, and cannot be described by the Schr\"{o}dinger equation. In this paper, starting with pure states, we show how the continuous collapse of the wave function can be described by the Schr\"{o}dinger equation with a stochastic, time-dependent Hamiltonian. We analytically solve for the Hamiltonian responsible for projective measurements on an arbitrary $n$-level system and the position measurement on an harmonic oscillator in the ground state, and propose several experimental schemes to verify and utilize the conclusions. A critical feature is that the Hamiltonian must be state-dependent. We then discuss how the above formalism can also be applied to describe the collapse of the wave function of mixed quantum states. The formalism we proposed may unify the two distinct evolutions in quantum mechanics.Comment: 12 pages, 1 figur

Quantifying goodness of story narratives

In the present study an additional measure of story narrative performance, story completeness, is evaluated. The completeness measure involves a tally of the critical story components mentioned by a storyteller. It was hypothesized that by combining organizational (story grammar) and completeness measures, story “goodness” could be quantified. Data from 46 normal adults indicated that this analysis was relatively sensitive in that it classified the story narratives of the group into four distinct categories of story “goodness”. This analysis should prove useful for the study of narrative discourse of brain-injured populations

Quantifying goodness of story narratives

In the present study an additional measure of story narrative performance, story completeness, is evaluated. The completeness measure involves a tally of the critical story components mentioned by a storyteller. It was hypothesized that by combining organizational (story grammar) and completeness measures, story “goodness” could be quantified. Data from 46 normal adults indicated that this analysis was relatively sensitive in that it classified the story narratives of the group into four distinct categories of story “goodness”. This analysis should prove useful for the study of narrative discourse of brain-injured populations