BIOE 402. Medical Technology Assessment. 2 or 3 hours. Bioentrepreneur course. Assessment of medical technology in the context of commercialization. Objectives, competition, market share, funding, pricing, manufacturing, growth, and intellectual property; many issues unique to biomedical products. Course Information: 2 undergraduate hours. 3 graduate hours. Prerequisite(s): Junior standing or above and consent of the instructor.

“Bioinformatics” 특집을 내면서

Coiled‐coils are found in proteins throughout all three kingdoms of life. Coiled‐coil domains of some proteins are almost invariant in sequence and length, betraying a structural and functional role for amino acids along the entire length of the coiled‐coil. Other coiled‐coils are divergent in sequence, but conserved in length, thereby functioning as molecular spacers. In this capacity, coiled‐coil proteins influence the architecture of organelles such as centrioles and the Golgi, as well as permit the tethering of transport vesicles. Specialized coiled‐coils, such as those found in motor proteins, are capable of propagating conformational changes along their length that regulate cargo binding and motor processivity. Coiled‐coil domains have also been identified in enzymes, where they function as molecular rulers, positioning catalytic activities at fixed distances. Finally, while coiled‐coils have been extensively discussed for their potential to nucleate and scaffold large macromolecular complexes, structural evidence to substantiate this claim is relatively scarce.

/pdf/coiled-coils-the-long-and-short-of-it-3qyfcikghr.pdf

Coiled‐coils: The long and short of it

Fast degradation rates in the physiological environment constitute the main limitation for magnesium alloys used in biodegradable hard tissue implants. In this work, the corrosion behavior of AZ91 magnesium alloy in simulated body fluids (SBF) was systematically investigated to determine its performance in a physiological environment. The influence of the main constituent phases on the corrosion behavior was studied by in situ visual observation and scanning electron microscopy. Energy dispersive x-ray spectrometry and Fourier transfer infrared spectroscopy revealed that both calcium and magnesium phosphates are present in the corroded products besides magnesium oxide. Electrochemical methods including open circuit potential evolution and electrochemical impedance spectroscopy were used to investigate the mechanism. The corresponding electrode controlled processes and evolution of the corrosion products layer were discussed. The degradation rate after immersion in SBF for seven days was calculated from both the weight loss and hydrogen evolution methods.

https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0884291400025589

Corrosion behavior of biomedical AZ91 magnesium alloy in simulated body fluids

Crystal orientation and electrochemical corrosion of polycrystalline Mg

The atomic nucleus is a quantum many-body system whose constituent nucleons (protons and neutrons) are subject to complex nucleon-nucleon interactions that include spin- and isospin-dependent components. For stable nuclei, several decades ago, emerging seemingly regular patterns in some observables could already be described successfully within a shell-model picture that results in particularly stable nuclei at certain magic fillings of the shells with protons and/or neutrons: N, Z=8, 20, 28, 50, 82, 126. However, in short-lived, so-called exotic nuclei or rare isotopes, characterized by a large N/Z asymmetry and located far from the valley of β stability on the nuclear chart, these magic numbers, viewed through observables, were shown to change. These changes in the regime of exotic nuclei offer an unprecedented view at the roles of the various components of the nuclear force when theoretical descriptions are confronted with experimental data on exotic nuclei where certain effects are enhanced. This article reviews the driving forces behind shell evolution from a theoretical point of view and connects this to experimental signatures.

/pdf/evolution-of-shell-structure-in-exotic-nuclei-3lvumr2ez4.pdf

Evolution of shell structure in exotic nuclei

The highly abundant α-helical coiled-coil motif not only mediates crucial protein-protein interactions in the cell but is also an attractive scaffold in synthetic biology and material science and a potential target for disease intervention. Therefore a systematic understanding of the coiled-coil interactions (CCIs) at the organismal level would help unravel the full spectrum of the biological function of this interaction motif and facilitate its application in therapeutics. We report the first identified genome-wide CCI network in Saccharomyces cerevisiae, which consists of 3495 pair-wise interactions among 598 predicted coiled-coil regions. Computational analysis revealed that the CCI network is specifically and functionally organized and extensively involved in the organization of cell machinery. We further show that CCIs play a critical role in the assembly of the kinetochore, and disruption of the CCI network leads to defects in kinetochore assembly and cell division. The CCI network identified in this study is a valuable resource for systematic characterization of coiled coils in the shaping and regulation of a host of cellular machineries and provides a basis for the utilization of coiled coils as domain-based probes for network perturbation and pharmacological applications.

Coiled-coil networking shapes cell molecular machinery

The onset of the superfluid phase in high-density neutron matter is studied within the BCS framework with two- and three-body forces. When including the strong correlation effects in the gap equation, the pairing gap turns out to be nonvanishing in a range of densities about $0.1--0.4\phantom{\rule{0.28em}{0ex}}{\text{fm}}^{\ensuremath{-}3}$ with a peak value a bit less than 0.05 MeV. These results could limit the role of the ${}^{3}{\mathit{PF}}_{2}$ superfluidity in the interpretation of phenomena occurring in the neutron-star core.

3 PF 2 pairing in high-density neutron matter

The corrosion behavior of as-cast AZ91D magnesium alloy in 0.1M sodium sulfate solution at the corrosion potential (E-corr) was investigated by using electrochemical impedance spectroscopy (EIS), environmental scanning electron microscopy (ESEM), energy dispersive X-ray spectroscopy (EDS) and X-ray diffraction (XRD). The results showed that the corrosion of AZ91D started at both the primary alpha-Mg and the eutectic alpha-Mg. The surface first was covered by a film (MgO, Mg(OH)2) which became thicker with time. Due to the dissolution of the eutectic alpha-Mg, the concentration of aluminum increased, MgAl2(SO4)(4). 2H(2)O precipitated at the primary alpha-Mg and progressively spread to the eutectic alpha-Mg areas. The surface film changed from two-layer to three-layer structure with the increase of immersion time.

Corrosion behavior of AZ91D magnesium alloy in sodium sulfate solution

In the framework of the Hartree-Fock-Bogoliubov approach with the Skyrme interactions SLy5, SLy5$+$T, SLy5$+$T${}_{w}$, and several sets of the TIJ parametrizations (Skyrme effective interaction parametrizations including the tensor terms), the effect of the tensor force on the shell evolution at $Z,N=8$, 20, and 28 is investigated It is shown that the evolution of the gap (defined as the energy difference between the last occupied and first unoccupied single-particle orbits) with SLy5$+$T is similar to that with SLy5$+$T${}_{w}$, and the gap values with SLy5$+$T are smaller than those with SLy5$+$T${}_{w}$ in the cases of $Z,N=8$, 20 At Z, N $=$ 28, the gap values with SLy5 are smaller than those with SLy5$+$T and larger than those with SLy5$+$T${}_{w}$ To understand these features, we analyze the spin-orbit potentials with and without the tensor contributions and the radial wave functions of relevant orbits Meanwhile, we find that the deviation of the calculated gaps with SLy5$+$T${}_{w}$ from the experimental ones is larger than that with SLy5$+$T This indicates that SLy5$+$T${}_{w}$ is not suitable for investigating the properties of the ground-state gap evolution Finally, it is seen that the gap evolutions with different sets of the TIJ parametrizations are similar to each other except for the ones with T22, and there is almost no difference between the tensor effect in gap evolution with the perturbative method and the one with the complete fitting method

Systematic study of tensor effects in shell evolution

To gain a better insight into $\ensuremath{\alpha}$-decay fine structure, we calculate the relative intensities of $\ensuremath{\alpha}$ decay to $2{}^{+}$ and $4{}^{+}$ rotational states in the framework of the generalized liquid drop model (GLDM) and improved Royer's formula. The calculated relative intensities of $\ensuremath{\alpha}$ decay to $2{}^{+}$ states are in good agreement with the experimental data. For the relative intensities of $\ensuremath{\alpha}$ decay to $4{}^{+}$ states, a good agreement with experimental data is achieved for Th and U isotopes. The formula we obtain is useful for the analysis of experimental data of $\ensuremath{\alpha}$-decay fine structure. In addition, some predicted relative intensities which are still not measured are provided for future experiments.

J. M. Dong

Papers

Coiled-coil networking shapes cell molecular machinery

3 PF 2 pairing in high-density neutron matter

Corrosion behavior of AZ91D magnesium alloy in sodium sulfate solution

Systematic study of tensor effects in shell evolution

Fine structure of α decay to rotational states of heavy nuclei