Alginate Microencapsulation of Human Islets Does Not Increase Susceptibility to Acute Hypoxia

Islet transplantation in diabetes is hampered by the need of life-long immunosuppression. Encapsulation provides partial immunoprotection but could possibly limit oxygen supply, a factor that may enhance hypoxia-induced beta cell death in the early posttransplantation period. Here we tested susceptibility of alginate microencapsulated human islets to experimental hypoxia (0.1–0.3% O2 for 8 h, followed by reoxygenation) on viability and functional parameters. Hypoxia reduced viability as measured by MTT by 33.8±3.5% in encapsulated and 42.9±5.2% in nonencapsulated islets (P<0.2). Nonencapsulated islets released 37.7% (median) more HMGB1 compared to encapsulated islets after hypoxic culture conditions (P<0.001). Glucose-induced insulin release was marginally affected by hypoxia. Basal oxygen consumption was equally reduced in encapsulated and nonencapsulated islets, by 22.0±6.1% versus 24.8±5.7%. Among 27 tested cytokines/chemokines, hypoxia increased the secretion of IL-6 and IL-8/CXCL8 in both groups of islets, whereas an increase of MCP-1/CCL2 was seen only with nonencapsulated islets. Conclusion. Alginate microencapsulation of human islets does not increase susceptibility to acute hypoxia. This is a positive finding in relation to potential use of encapsulation for islet transplantation

The ability of 1.23% acidulated phosphate fluoride gel to inhibit simulated endogenous erosion in tooth roots

The document attached has been archived with permission from the Australian Dental Association. An external link to the publisher’s copy is included.Background: Endogenous dental erosion is that produced by contact of gastric acids with tooth structure. It may affect exposed root cementum/ dentine as well as coronal enamel, causing marked loss of mineral. The aim of this study was to determine whether 1.23 per cent acidulated phosphate fluoride gel, if applied to the surface cementum at certain intervals during an erosive acid challenge, could provide any protection against demineralization. Materials and methods: Roots of preserved extracted human teeth were painted with a water and acid resistant varnish, leaving two windows (3x1mm) of exposed dentine. These were placed in a solution containing 0.06MHCl and 2.2mMCaHPO4, which has been shown to simulate gastric acid when it meets the tooth surface. The roots were placed in the erosive solution unprotected (controls), or subject to APF application for four minutes prior to and every 10, 30 or 120 minutes during the erosive challenge. Roots were removed at either 6 or 12 hours, washed thoroughly and cut into 120μm thick sections. Depths of demineralization were measured using an optical graticule under polarized light microscopy. Results: A high level of protection was provided when the roots were coated with APF gel every 10 or 30 minutes. Conclusions: APF gel will partially inhibit endogenous erosion of roots for up to 30 minutes if applied, for example, the night before a morning reflux episode. This should be considered along with other erosion control or reduction procedures for patients suffering from the effects of endogenous erosion.JGC Saunders and JM McIntyr

Spin-orbit torques for current parallel and perpendicular to a domain wall

We report field- and current-induced domain wall (DW) depinning experiments in Ta/Co20Fe60B20/MgO nanowires through a Hall cross geometry. While purely field-induced depinning shows no angular dependence on in-plane fields, the effect of the current depends crucially on the internal DW structure, which we manipulate by an external magnetic in-plane field. We show for the first time depinning measurements for a current sent parallel to the DW and compare its depinning efficiency with the conventional case of current flowing perpendicularly to the DW. We find that the maximum efficiency is similar for both current directions within the error bars, which is in line with a dominating damping-like spin-orbit torque (SOT) and indicates that no large additional torques arise for currents parallel to the DW. Finally, we find a varying dependence of the maximum depinning efficiency angle for different DWs and pinning levels. This emphasizes the importance of our full angular scans compared to previously used measurements for just two field directions (parallel and perpendicular to the DW) and shows the sensitivity of the spin-orbit torque to the precise DW structure and pinning sites.Comment: 11 pages, 3 figure

Spin Damping Monopole

We present theoretical evidence that a magnetic monopole emerges in dynamic magnetic systems in the presence of the spin-orbit interaction. The monopole field is expressed in terms of spin damping associated with magnetization dynamics. We demonstrate that the observation of this spin damping monopole is accomplished electrically using Ampere's law for monopole current. Our discovery suggests the integration of monopoles into electronics, namely, monopolotronics.Comment: 9 pages, 1 figure

The Pattern of the Mineralization of Enamel

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68291/2/10.1177_00220345610400050101.pd

Antiferromagnetic spintronics

Antiferromagnetic materials are magnetic inside, however, the direction of their ordered microscopic moments alternates between individual atomic sites. The resulting zero net magnetic moment makes magnetism in antiferromagnets invisible on the outside. It also implies that if information was stored in antiferromagnetic moments it would be insensitive to disturbing external magnetic fields, and the antiferromagnetic element would not affect magnetically its neighbors no matter how densely the elements were arranged in a device. The intrinsic high frequencies of antiferromagnetic dynamics represent another property that makes antiferromagnets distinct from ferromagnets. The outstanding question is how to efficiently manipulate and detect the magnetic state of an antiferromagnet. In this article we give an overview of recent works addressing this question. We also review studies looking at merits of antiferromagnetic spintronics from a more general perspective of spin-ransport, magnetization dynamics, and materials research, and give a brief outlook of future research and applications of antiferromagnetic spintronics.Comment: 13 pages, 7 figure

From DNA sequence to application: possibilities and complications

The development of sophisticated genetic tools during the past 15 years have facilitated a tremendous increase of fundamental and application-oriented knowledge of lactic acid bacteria (LAB) and their bacteriophages. This knowledge relates both to the assignments of open reading frames (ORF’s) and the function of non-coding DNA sequences. Comparison of the complete nucleotide sequences of several LAB bacteriophages has revealed that their chromosomes have a fixed, modular structure, each module having a set of genes involved in a specific phase of the bacteriophage life cycle. LAB bacteriophage genes and DNA sequences have been used for the construction of temperature-inducible gene expression systems, gene-integration systems, and bacteriophage defence systems. The function of several LAB open reading frames and transcriptional units have been identified and characterized in detail. Many of these could find practical applications, such as induced lysis of LAB to enhance cheese ripening and re-routing of carbon fluxes for the production of a specific amino acid enantiomer. More knowledge has also become available concerning the function and structure of non-coding DNA positioned at or in the vicinity of promoters. In several cases the mRNA produced from this DNA contains a transcriptional terminator-antiterminator pair, in which the antiterminator can be stabilized either by uncharged tRNA or by interaction with a regulatory protein, thus preventing formation of the terminator so that mRNA elongation can proceed. Evidence has accumulated showing that also in LAB carbon catabolite repression in LAB is mediated by specific DNA elements in the vicinity of promoters governing the transcription of catabolic operons. Although some biological barriers have yet to be solved, the vast body of scientific information presently available allows the construction of tailor-made genetically modified LAB. Today, it appears that societal constraints rather than biological hurdles impede the use of genetically modified LAB.

Impact of episiotomy on pelvic floor disorders and their influence on women's wellness after the sixth month postpartum: a retrospective study

<p>Abstract</p> <p>Background</p> <p>The role of episiotomy as a protective factor against pelvic floor disorders postpartum has been debated for many years, but its routine use has been hitherto discouraged in the literature. Comparisons between restrictive and routine use of episiotomy in existent literature, however, fail to include any consideration relating to quality of life. The aim of this study, therefore, is to state the role of episiotomy in preserving the perineum from damage, in order to prevent the influence of pelvic floor disorders on women's psycho-physical wellness after the sixth month postpartum.</p> <p>Methods</p> <p>A follow-up telephone interview was performed among 377 primiparous and secondiparous Caucasian women who had a child by spontaneous or operative vaginal delivery in 2006 using a self-created questionnaire and King's Health Questionnaire (KHQ).</p> <p>Results</p> <p>The mean age at delivery was 35.26 (±4.68) years and episiotomy was performed in 59.2% of women. Multivariate linear regression shows episiotomy associated to higher quality of life after the sixth month postpartum by correlating with inferior values of King's Health Questionnaire (p < 0.05).</p> <p>Conclusions</p> <p>Episiotomy appears to be a protective factor for women's wellness. Women who had episiotomy and who experienced perineal symptoms have a better psycho-physical health status in the 12.79 months (±3.3) follow-up.</p

A multi-centre quality improvement project to reduce the incidence of obstetric anal sphincter injury (OASI): study protocol.

BACKGROUND: Third and fourth degree perineal tears, or obstetric anal sphincter injuries (OASI), sustained during childbirth can result in anal incontinence and psychosocial problems which require ongoing treatment. Within the English National Health System (NHS) reported rates of OASI have gradually increased. In response, a care bundle was developed incorporating four elements: 1) antenatal information to women, 2) manual perineal protection during all vaginal births, 3) episiotomy to be performed with a 60° mediolateral angle at crowning (when clinically indicated) and 4) perineal examination (including per rectum) after childbirth. Implementation of the OASI Care Bundle is aided by a skills development module and an awareness campaign. The project is a collaboration between two national professional bodies, an NHS hospital trust and an academic institution. METHODS: Implementation of the OASI Care Bundle will be evaluated using a stepped-wedge design. From January 2017 sixteen maternity units across England, Wales and Scotland will participate in the study over a 15-month period, with sequential roll-out of the intervention in four blocks (regions) of four units. The primary clinical outcome is OASI rate. Regression analysis will adjust for differences in organisational characteristics and obstetric risk factors in women who gave birth before and after implementation of the care bundle. Focus group discussions and in-depth interviews with clinicians will evaluate the feasibility of integrating the care bundle into routine practice. Interviews with women will explore the acceptability of the intervention. DISCUSSION: This protocol outlines the evaluation of our quality improvement project which aims to prevent OASI using a bundle of evidence-based interventions that are each widely used in practice. The OASI project aims to 1) standardise practice to prevent OASI in a way that is acceptable to clinicians and women and 2) identify the barriers and enablers associated with upscaling interventions within maternity units. If found to be effective, feasible and acceptable, the OASI Care Bundle will be shared with a range of audiences using the communication channels available to the professional bodies. TRIAL REGISTRATION: The OASI Project was retrospectively registered on the ISCTRN12143325 database date assigned 03/10/2017