Ferroelectric polymer gates for non-volatile field effect control of ferromagnetism in (Ga, Mn)As layers.

(Ga, Mn)As and other diluted magnetic semiconductors (DMS) attract a great deal of attention for potential spintronic applications because of the possibility of controlling the magnetic properties via electrical gating. Integration of a ferroelectric gate on the DMS channel adds to the system a non-volatile memory functionality and permits nanopatterning via the polarization domain engineering. This topical review is focused on the multiferroic system, where the ferromagnetism in the (Ga, Mn)As DMS channel is controlled by the non-volatile field effect of the spontaneous polarization. Use of ferroelectric polymer gates in such heterostructures offers a viable alternative to the traditional oxide ferroelectrics generally incompatible with DMS. Here we review the proof-of-concept experiments demonstrating the ferroelectric control of ferromagnetism, analyze the performance issues of the ferroelectric gates and discuss prospects for further development of the ferroelectric/DMS heterostructures toward the multiferroic field effect transistor.

Studies on the leukocytosis and lymphocytosis induced by Bordetella pertussis. I. Radioautographic analysis of the circulating cells in mice undergoing pertussis-induced hyperleukocytosis.

By the use of radioautographic techniques it was shown that the lymphocytosis induced by Bordetella pertussis in mice was not caused by an increased production of lymphocytes but was primarily due to the entry into the circulation of mature cells from tissue pools. The accompanying polymorphonuclear leukocytosis was due to both proliferation of myeloid elements and entry of mature cells from tissue reserves, with the former the predominant mechanism.

Studies on the leukocytosis and lymphocytosis induced by Bordetella pertussis. II. The effect of pertussis vaccine on the thoracic duct lymph and lymphocytes of mice.

The 24 hr volume flow, cell concentration, and total cell output of thoracic duct fluid from mice with pertussis-induced hyperlymphocytosis were markedly reduced when compared with values obtained in normal animals. An increase in the number of circulating lymphocytes occurred in several of the pertussis-treated mice despite the presence of an indwelling thoracic duct cannula. The drainage from such animals also showed a reduced cell concentration and total cell output. It is suggested that lymphocyte recirculation may be minimal in pertussis-induced lymphocytosis, and the evidence obtained also suggests that lymphocytes may enter the blood stream by direct routes during the course of the reaction.

Non-volatile ferroelectric control of ferromagnetism in (Ga,Mn)As.

Multiferroic structures that provide coupled ferroelectric and ferromagnetic responses are of significant interest as they may be used in novel memory devices and spintronic logic elements. One approach towards this goal is the use of composites that couple ferromagnetic and ferroelectric layers through magnetostrictive and piezoelectric strain transmitted across the interfaces. However, mechanical clamping of the films to the substrate limits their response. Structures where the magnetic response is modulated directly by the electric field of the poled ferroelectric would eliminate this constraint and provide a qualitatively higher level of integration, combining the emerging field of multiferroics with conventional semiconductor microelectronics. Here, we report the realization of such a device using (Ga,Mn)As, which is an archetypical diluted magnetic semiconductor with well-understood carrier-mediated ferromagnetism, and a polymer ferroelectric gate. Polarization reversal of the gate by a single voltage pulse results in a persistent modulation of the Curie temperature of the ferromagnetic semiconductor. The non-volatile gating of (Ga,Mn)As has been made possible by applying a low-temperature copolymer deposition technique that is distinct from pre-existing technologies for ferroelectric gates on magnetic oxides. This accomplishment opens a way to nanometre-scale modulation of magnetic semiconductor properties with rewritable ferroelectric domain patterns, operating at modest voltages and subnanosecond times.

Effectiveness of rosiglitazone in reducing flexion contracture in a rabbit model of arthrofibrosis with surgical capsular release: A biomechanical, histological, and genetic analysis.

AIMS: Animal models have been developed that allow simulation of post-traumatic joint contracture. One such model involves contracture-forming surgery followed by surgical capsular release. This model allows testing of antifibrotic agents, such as rosiglitazone. METHODS: A total of 20 rabbits underwent contracture-forming surgery. Eight weeks later, the animals underwent a surgical capsular release. Ten animals received rosiglitazone (intramuscular initially, then orally). The animals were sacrificed following 16 weeks of free cage mobilisation. The joints were tested biomechanically, and the posterior capsule was assessed histologically and via genetic microarray analysis. RESULTS: There was no significant difference in post-traumatic contracture between the rosiglitazone and control groups (33° (standard deviation (sd) 11) vs 37° (sd14), respectively; p = 0.4). There was no difference in number or percentage of myofibroblasts. Importantly, there were ten genes and 17 pathways that were significantly modulated by rosiglitazone in the posterior capsule. DISCUSSION: Rosiglitazone significantly altered the genetic expression of the posterior capsular tissue in a rabbit model, with ten genes and 17 pathways demonstrating significant modulation. However, there was no significant effect on biomechanical or histological properties.Cite this article: M. P. Abdel. Effectiveness of rosiglitazone in reducing flexion contracture in a rabbit model of arthrofibrosis with surgical capsular release: A biomechanical, histological, and genetic analysis. Bone Joint Res 2016;5:11-17. doi: 10.1302/2046-3758.51.2000593.

Perioperative nursing. Designing, implementing a baccalaureate elective.

The clinical faculty of the affiliated teaching hospitals felt the initial course offering was beneficial to students and institutions alike. The course served as a foundation for the students' entry into perioperative nursing practice, and served to shorten the amount of time institutions invest in orientation. In conclusion, we recognize the importance of offering a perioperative nursing educational opportunity at the baccalaureate level. With increased student interest, we are looking forward to continuing the course and implementing the refinements as recommended.

Incorporation of an additional viral-clearance step into a human immunoglobulin manufacturing process.

BACKGROUND AND OBJECTIVES: Regulatory agencies have mandated that manufacturers of immunoglobulin products incorporate robust viral inactivation or removal steps into their purification processes. We evaluated the effectiveness of incorporating nanofiltration, a generic virus-clearance step, into an existing plasma-fractionation process for a human anti-D immunoglobulin product. MATERIALS AND METHODS: The nanofiltration process studied utilizes a 180 000-molecular weight composite membrane with well-defined pore distribution. To examine its viral-clearance capability, diluted anti-D immunoglobulin was spiked with high concentrations of human and animal model viruses and subjected to tangential-flow nanofiltration during scaled-down validation runs. Viral clearance by the membrane was determined by calculating log removal values in accordance with guidelines provided by US and European regulatory agencies. RESULTS: Nanofiltration removed viruses of varying sizes and physical characteristics. For the three non-enveloped viruses tested (porcine parvovirus, encephalomyocarditis virus and hepatitis A virus, sizes 18-30 nm), clearance was 3.3, 4.1 and > 5.1 log, respectively. For the three enveloped viruses (human immunodeficiency virus-1, bovine viral diarrhoea virus and pseudorabies virus, 50-200 nm), a substantial 5-log reduction was demonstrated. Product potency, purity and stability were unaffected. CONCLUSION: Tangential-flow nanofiltration provides substantial virus-removal capabilities for immunoglobulin preparations.