Envisioning patient safety in Telehealth: a research perspective

This article explores the need for research into patient safety in large-scale Telehealth systems faced with the perspective of its development extended to healthcare systems. Telehealth systems give rise to significant advantages in improving the quality of healthcare services as well as bringing about the possibility of new types of risk. A theoretical framework is proposed for patient safety for its approach as an emerging property in complex socio-technical systems (CSTS) and their modelling in layers. As regards this framework, the differential characteristic Telehealth elements of the system have been identified, with a greater emphasis on the level of Telehealth system and its typical subsystems. The bases of the analysis are based on references in the literature and the experience accumulated by the researchers in the area. In particular, a case describing an example of Telehealth to control patients undergoing treatment with oral anticoagulants is used. As a result, a series of areas of research into and topics regarding Telehealth patient safety are proposed to cover the detectable gaps. Both the theoretical and practical implications of the study are discussed and future perspectives are reflected on.This research has been partially supported by grants FISPI09-90110 ‘Innovation Platform in new services based on telemedicine and e-health for chronic and dependent patients -PITES’ from the Ministry of Health & Consumer Affairs; and FISPI13-00508 ‘Innovation platform in new services based on Telemedicine and e- Health: definition, design and development of tools for interoperability, patient safety and support to decision (PITES-ISA)’ from the Ministry of Economy and Competitiveness (Secretary of State of Research, Development and Innovation). The funders had no role in the study, decision to publish, or drafting of the manuscript.S

In Memorium: Swamy Laxminarayan [1939–2005]

Swamy Narasimha Laxminarayan, known to his many friends and colleagues as Swamy, passed away on September 29, 2005. He was one of the most prominent biomedical engineers on the international scene, and contributed immensely to the globalization of this new field

TSC1 stabilizes TSC2 by inhibiting the interaction between TSC2 and the HERC1 ubiquitin ligase

Tuberous sclerosis complex (TSC) is an autosomal dominant disease characterized by hamartoma formation in various organs. Two genes responsible for the disease, TSC1 and TSC2, have been identified. The TSC1 and TSC2 proteins, also called hamartin and tuberin, respectively, have been shown to regulate cell growth through inhibition of the mammalian target of rapamycin pathway. TSC1 is known to stabilize TSC2 by forming a complex with TSC2, which is a GTPase-activating protein for the Rheb small GTPase. We have identified HERC1 as a TSC2-interacting protein. HERC1 is a 532-kDa protein with an E3 ubiquitin ligase homology to E6AP carboxyl terminus (HECT) domain. We observed that the interaction of TSC1 with TSC2 appears to exclude TSC2 from interacting with HERC1. Disease mutations in TSC2, which result in its destabilization, allow binding to HERC1 in the presence of TSC1. Our study reveals a potential molecular mechanism of how TSC1 stabilizes TSC2 by excluding the HERC1 ubiquitin ligase from the TSC2 complex. Furthermore, these data reveal a possible biochemical basis of how certain disease mutations inactivate TSC2

Complex formation between ferredoxin and Synechococcus ferredoxin:nitrate oxidoreductase

AbstractThe ferredoxin-dependent nitrate reductase from the cyanobacterium Synechococcus sp. PCC 7942 has been shown to form a high-affinity complex with ferredoxin at low ionic strength. This complex, detected by changes in both the absorbance and circular dichroism (CD) spectra, did not form at high ionic strength. When reduced ferredoxin served as the electron donor for the reduction of nitrate to nitrite, the activity of the enzyme declined markedly as the ionic strength increased. In contrast, the activity of the enzyme with reduced methyl viologen (a non-physiological electron donor) was independent of ionic strength. These results suggest that an electrostatically stabilized complex between Synechococcus nitrate reductase and ferredoxin plays an important role in the mechanism of nitrate reduction catalyzed by this enzyme. Treatment of Synechococcus nitrate reductase with either an arginine-modifying reagent or a lysine-modifying reagent inhibited the ferredoxin-dependent activity of the enzyme but did not affect the methyl viologen-dependent activity. Treatment with these reagents also resulted in a large decrease in the affinity of the enzyme for ferredoxin. Formation of a nitrate reductase complex with ferredoxin prior to treatment with either reagent protected the enzyme against loss of ferredoxin-dependent activity. These results suggest that lysine and arginine residues are present at the ferredoxin-binding site of Synechococcus nitrate reductase. Results of experiments using site-specific, charge reversal variants of the ferredoxin from the cyanobacterium Anabaena sp. PCC 7119 as an electron donor to nitrate reductase were consistent with a role for negatively charged residues on ferredoxin in the interaction with Synechococcus nitrate reductase

Dipolar Excitons, Spontaneous Phase Coherence, and Superfluid-Insulator Transition in Bi-layer Quantum Hall Systems at ν=1\nu=1

The spontaneous interlayer phase coherent (111) state of bi-layer Quantum Hall system at filling factor $\nu=1$ may be viewed as a condensate of interlayer particle-hole pairs or excitons. We show in this paper that when the layers are biased in such a way that these excitons are very dilute, they may be viewed as point-like bosons. We calculate the exciton dispersion relation, and show that the exciton-exciton interaction is dominated by the dipole moment they carry. In addition to the phase coherent state, we also find a Wigner Crystal/Glass phase in the presence/absence of disorder which is an insulating state for the excitons. The position of the phase boundary is estimated and the properties of the superfluid-insulator type transition between these two phases is discussed. We also discuss the relation between these "dipolar" excitons and the "dipolar" composite fermions studied in the context of half-filled Landau level.Comment: 4 pages with one embedded eps figur

Field-free spin-orbit torque-induced switching of perpendicular magnetization in a ferrimagnetic layer with vertical composition gradient

Current-induced spin-orbit torques (SOTs) are of interest for fast and energy-efficient manipulation of magnetic order in spintronic devices. To be deterministic, however, switching of perpendicularly magnetized materials by SOT requires a mechanism for in-plane symmetry breaking. Existing methods to do so involve the application of an in-plane bias magnetic field, or incorporation of in-plane structural asymmetry in the device, both of which can be difficult to implement in practical applications. Here, we reported bias-field-free SOT switching in a single perpendicular CoTb layer with an engineered vertical composition gradient. The vertical structural inversion asymmetry induces strong intrinsic SOTs and a gradient-driven Dzyaloshinskii-Moriya interaction (g-DMI), which breaks the in-plane symmetry during the switching process. Micromagnetic simulations are in agreement with experimental results, and elucidate the role of g-DMI in the deterministic switching. This bias-field-free switching scheme for perpendicular ferrimagnets with g-DMI provides a strategy for efficient and compact SOT device design.Comment: 27 pages, 5 figure

Spontaneous Interlayer Coherence in Double-Layer Quantum Hall Systems: Symmetry Breaking Interactions, In-Plane Fields and Phase Solitons

At strong magnetic fields double-layer two-dimensional-electron-gas systems can form an unusual broken symmetry state with spontaneous inter-layer phase coherence. The system can be mapped to an equivalent system of pseudospin $1/2$ particles with pseudospin-dependent interactions and easy-plane magnetic order. In this paper we discuss how the presence of a weak interlayer tunneling term alters the properties of double-layer systems when the broken symmetry is present. We use the energy functional and equations of motion derived earlier to evaluate the zero-temperature response functions of the double-layer system and use our results to discuss analogies between this system and Josephson-coupled superconducting films. We also present a qualitative picture of the low-energy charged excitations of this system. We show that parallel fields induce a highly collective phase transition to an incommensurate state with broken translational symmetry.Comment: 26 pages, RevTex, 8 postscript figures (submitted to Phys. Rev. B

Spontaneous Inter-layer Coherence in Double-Layer Quantum-Hall Systems I: Charged Vortices and Kosterlitz-Thouless Phase Transitions

At strong magnetic fields double-layer two-dimensional-electron-gas systems can form an unusual broken symmetry state with spontaneous inter-layer phase coherence. In this paper we explore the rich variety of quantum and finite-temperature phase transitions associated with this broken symmetry. We describe the system using a pseudospin language in which the layer degree-of-freedom is mapped to a fictional spin 1/2 degree-of-freedom. With this mapping the spontaneous symmetry breaking is equivalent to that of a spin 1/2 easy-plane ferromagnet. In this language spin-textures can carry a charge. In particular, vortices carry e/2 electrical charge and vortex-antivortex pairs can be neutral or carry charge e. We derive an effective low-energy action and use it to discuss the charged and collective neutral excitations of the system. We have obtained the parameters of the Landau-Ginzburg functional from first-principles estimates and from finite-size exact diagonalization studies. We use these results to estimate the dependence of the critical temperature for the Kosterlitz-Thouless phase transition on layer separation.Comment: 56 pages, 19 figures available upon request at [email protected]. RevTex 3.0. IUCM94-00