The effect of metal ions released from different dental implant-abutment couples on osteoblast function and secretion of bone resorbing mediators

OBJECTIVES: The etiology of the reduced marginal bone loss observed around platform-switched implant-abutment connections is not clear but could be related to the release of variable amounts of corrosion products. The present study evaluated the effect of different concentrations of metal ions released from different implant abutment couples on osteoblastic cell viability, apoptosis and expression of genes related to bone resorption. METHODS: Osteoblastic cells were exposed to five conditions of culture media prepared containing metal ions (titanium, aluminum, vanadium, cobalt, chromium and molybdenum) in different concentrations representing the amounts released from platform-matched and platform-switched implant-abutment couples as a result of an earlier accelerated corrosion experiment. Cell viability was evaluated over 21days using the Alamar Blue assay. Induction of apoptosis was measured after 24h of exposure using flow cytometry. Expression of interleukin-6, interleukin-8, cyclooxygenase-2, caspase-8, osteoprotegerin and receptor activator of nuclear factor kappa-B ligand (RANKL) by osteoblastic cells were analysed after exposure for 1, 3 and 21days using real-time quantitative polymerase chain reaction assay RESULTS: Metal ions in concentrations representing the platform-matched groups led to a reduction in cell viability (P<0.01) up to 7days of exposure. Stimulated cells showed higher rates of early apoptosis (P<0.01) compared to non-treated cells. Metal ions up-regulated the expression of interleukin-6, interleukin-8, cyclooxygenase-2 and RANKL in a dose dependent manner after 1day of exposure (P<0.05). The up-regulation was more pronounced in the groups containing the corrosion products of platform-matched implant-abutment couples. CONCLUSION: Osteoblastic cell viability, apoptosis, and regulation of bone resorbing mediators were significantly altered in the presence of metal ions. The change in cytokine levels expressed was directly proportional to the metal ion concentration. CLINICAL SIGNIFICANCE: The observed biological responses to decreased amounts of metal ions released from platform-switched implant-abutment couples compared to platform-matched couples may partly explain the positive radiographic findings in respect to crestal bone level when utilising the "platform-switching" concept, which highlights the possible role of corrosion products in the mediation of crestal bone loss around dental implants

Brush/Fin Thermal Interfaces

Brush/fin thermal interfaces are being developed to increase heat-transfer efficiency and thereby enhance the thermal management of orbital replaceable units (ORUs) of electronic and other equipment aboard the International Space Station. Brush/fin thermal interfaces could also be used to increase heat-transfer efficiency in terrestrial electronic and power systems. In a typical application according to conventional practice, a replaceable heat-generating unit includes a mounting surface with black-anodized metal fins that mesh with the matching fins of a heat sink or radiator on which the unit is mounted. The fins do not contact each other, but transfer heat via radiation exchange. A brush/fin interface also includes intermeshing fins, the difference being that the gaps between the fins are filled with brushes made of carbon or other fibers. The fibers span the gap between intermeshed fins, allowing heat transfer by conduction through the fibers. The fibers are attached to the metal surfaces as velvet-like coats in the manner of the carbon fiber brush heat exchangers described in the preceding article. The fiber brushes provide both mechanical compliance and thermal contact, thereby ensuring low contact thermal resistance. A certain amount of force is required to intermesh the fins due to sliding friction of the brush s fiber tips against the fins. This force increases linearly with penetration distance, reaching ~1 psi (~6.9 kPa) for full 2-in. (5.1 cm) penetration for the conventional radiant fin interface. Removal forces can be greater due to fiber buckling upon reversing the sliding direction. This buckling force can be greatly reduced by biasing the fibers at an angle perpendicularly to the sliding direction. Means of containing potentially harmful carbon fiber debris, which is electrically conductive, have been developed. Small prototype brush/fin thermal interfaces have been tested and found to exhibit temperature drops about onesixth of that of conventional meshing-fin thermal interface, when fabricated as a retrofit. In this case, conduction through the long, thin metal fins themselves becomes a thermal bottleneck. Further improvement could be made by prescribing aluminum fins to be shorter and thicker than those of the conventional meshing-fin thermal interfaces; the choice of height and thickness would be optimized to obtain greater overall thermal conductance, lower weight, and lower cost

Phylogenetic structure of vertebrate communities across the A ustralian arid zone

Aim To understand the relative importance of ecological and historical factors in structuring terrestrial vertebrate assemblages across the A ustralian arid zone, and to contrast patterns of community phylogenetic structure at a continental scale. Location Australia. Methods We present evidence from six lineages of terrestrial vertebrates (five lizard clades and one clade of marsupial mice) that have diversified in arid and semi‐arid A ustralia across 37 biogeographical regions. Measures of within‐lineage community phylogenetic structure and species turnover were computed to examine how patterns differ across the continent and between taxonomic groups. These results were examined in relation to climatic and historical factors, which are thought to play a role in community phylogenetic structure. Analyses using a novel sliding‐window approach confirm the generality of processes structuring the assemblages of the A ustralian arid zone at different spatial scales. Results Phylogenetic structure differed greatly across taxonomic groups. Although these lineages have radiated within the same biome – the A ustralian arid zone – they exhibit markedly different community structure at the regional and local levels. Neither current climatic factors nor historical habitat stability resulted in a uniform response across communities. Rather, historical and biogeographical aspects of community composition (i.e. local lineage persistence and diversification histories) appeared to be more important in explaining the variation in phylogenetic structure. While arid‐zone assemblages show an overall tendency towards phylogenetic clustering, this pattern was less pronounced at finer spatial scales. Main conclusions By focusing within different taxonomic groups and between those groups within regions, we show that although the vertebrate lineages we examined exhibited high diversity and low turnover across the arid zone, the underlying phylogenetic structure differs between regions and taxonomic groups, suggesting that taxon‐specific histories are more important than habitat stability in determining patterns of phylogenetic community relatedness.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/98265/1/jbi12077.pd

Detailed liver-specific imaging prior to pre-operative chemotherapy for colorectal liver metastases reduces intra-hepatic recurrence and the need for a repeat hepatectomy

AbstractBackgroundNeoadjuvant chemotherapy for colorectal liver metastases (CRLM) reduces the accuracy of liver imaging which may understage patients pre-operatively. Retrospective review of a prospective database to determine whether liver-specific magnetic resonance imaging (MRI) prior to pre-operative chemotherapy affects intra-hepatic recurrence and long-term outcome after hepatectomy.Patients and methodsBetween 2003 and 2009, 242 patients with CRLM underwent a hepatectomy after ≥3 cycles of oxaliplatin or irinotecan-based chemotherapy. All had a liver-specific MRI immediately pre-operatively. The outcome of patients who had a liver-specific MRI prior to chemotherapy (PCI group, n= 92) was compared with those who did not (non-PCI group, n= 150).ResultsA liver-specific MRI pre-chemotherapy changed the staging in 56% of patients. At a median (range) follow-up of 55 (6–94) months, there was a higher incidence of intra-hepatic recurrence at a new site in the non-PCI group (65% vs. 48% in the PCI group, P= 0.041) and an increased rate of recurrence in patients with the same number of lesions pre- and post-chemotherapy [hazard ratio (HR) 2.02, 1:10–3.37, P= 0.024]. The non-PCI group underwent more repeat hepatectomies than the PCI group (24.7% vs. 13%, P= 0.034), achieving similar long-term survival.ConclusionsA liver-specific MRI prior to chemotherapy reduces intra-hepatic recurrence and avoids a repeat hepatectomy

Rainfastness of poly(vinyl alcohol) deposits on Vicia faba leaf surfaces: from laboratory-scale washing to simulated rain

Rainfastness is the ability of agrochemical deposits to resist wash-off by rain and other related environmental phenomena. This work reports laboratory-scale and raintower studies of the rainfastness of fluorescently labeled poly(vinyl alcohol) (PVA) using fluorescent microscopy combined with image analysis. Samples of hydrolyzed PVA exhibit improved rainfastness over a threshold molecular weight, which correlates with PVA film dissolution, swelling, and crystalline properties. It was also established that the rainfastness of PVA scaled with the molecular weight over this threshold. These PVA samples were further characterized in order to determine the effect of the crystallinity on rainfastness. The quantification of rainfastness is of great interest to the field of agrochemical formulation development in order to improve the efficacy of pesticides and their adjuvants

Liver specification of human iPSC-derived endothelial cells transplanted into mouse liver

Background & Aims: Liver sinusoidal endothelial cells (LSECs) are important in liver development, regeneration, and pathophysiology, but the differentiation process underlying their tissue-specific phenotype is poorly understood and difficult to study because primary human cells are scarce. The aim of this study was to use human induced pluripotent stem cell (hiPSC)-derived LSEC-like cells to investigate the differentiation process of LSECs. Methods: hiPSC-derived endothelial cells (iECs) were transplanted into the livers of Fah−/−/Rag2−/−/Il2rg−/− mice and assessed over a 12-week period. Lineage tracing, immunofluorescence, flow cytometry, plasma human factor VIII measurement, and bulk and single cell transcriptomic analysis were used to assess the molecular and functional changes that occurred following transplantation. Results: Progressive and long-term repopulation of the liver vasculature occurred as iECs expanded along the sinusoids between hepatocytes and increasingly produced human factor VIII, indicating differentiation into LSEC-like cells. To chart the developmental profile associated with LSEC specification, the bulk transcriptomes of transplanted cells between 1 and 12 weeks after transplantation were compared against primary human adult LSECs. This demonstrated a chronological increase in LSEC markers, LSEC differentiation pathways, and zonation. Bulk transcriptome analysis suggested that the transcription factors NOTCH1, GATA4, and FOS have a central role in LSEC specification, interacting with a network of 27 transcription factors. Novel markers associated with this process included EMCN and CLEC14A. Additionally, single cell transcriptomic analysis demonstrated that transplanted iECs at 4 weeks contained zonal subpopulations with a region-specific phenotype. Conclusions: Collectively, this study confirms that hiPSCs can adopt LSEC-like features and provides insight into LSEC specification. This humanised xenograft system can be applied to further interrogate LSEC developmental biology and pathophysiology, bypassing current logistical obstacles associated with primary human LSECs. Impact and implications: Liver sinusoidal endothelial cells (LSECs) are important cells for liver biology, but better model systems are required to study them. We present a pluripotent stem cell xenografting model that produces human LSEC-like cells. A detailed and longitudinal transcriptomic analysis of the development of LSEC-like cells is included, which will guide future studies to interrogate LSEC biology and produce LSEC-like cells that could be used for regenerative medicine

The Lantern, 2012-2013

• How They Run • What Was Said in Boston • On the Last Day of the Month • An Angel Tries to Surprise Humans • I Wonder if God Modeled Boys After Books • Marred with Modern Scars • Feather Bed • Ode to a Pen • Objet Petit A • Breaking News: Grownups Fear Return of Disco • Neuroscience • New Document • We Were Stars, and the Sky was Our Grass • About a Man • Trojan • An Ode • Yr Body Sour • That Lake in Jamaica • Live While Chiefs are Still Fighting • Lament for Mathematics • The Robert Frost House • People Fell in Love on Me • Sunday Review • Looks Silly in Tiny Desk Chairs • Two Years Later • Better Than Nothing • Istanbul • Packs of Cigarettes • Sonnet • Outside King of Steaks • Obstinance • Coffee Grinds • Autumn Equinox • Homecoming • Oh, San Francisco • Slide: A Beginning • Slowly Last Summer • Of Dogs and Men • Letters Not Sent • Before the Race • The Little Things • Tarpon Springs • Payment for Rebellion • Wednesday • When is President\u27s Day? • Heartless Parallels and Perpendiculars • Railway • Presto Agitato • Easier Said Than Done • Waves • Four White Women • Rope • Alter Ego Self Portrait • Pebbles • Coney Island • Guanjuanto • Growth • Evolve • Winter Blackout • Honeybee • Frames • Wanderlust • Guiding Light 1 • Frick\u27s Lock • The Ones That Never Leave • In Memoriam: Rachel Blunthttps://digitalcommons.ursinus.edu/lantern/1179/thumbnail.jp

A tyrosine-rich amelogenin peptide promotes neovasculogenesis in vitro and ex vivo

H.D.A. is grateful for the financial support provided by a Dorothy Hodgkin Postgraduate Award (jointly funded by the Engineering and Physical Sciences Research Council, UK and the Institut Straumann, Switzerland) and the Research Discretionary Funds of the Periodontology Unit, UCL Eastman Dental Institute. Financial support was also provided by the NIHR Comprehensive Biomedical Research Centre, UK and the WCU Program of the National Research Foundation of Korea (NRF), funded by the Ministry of Education, Science and Technology, South Korea (No. R31-10069)

Extending conceptual understanding : how interprofessional education influences affective domain development

Background: Interprofessional learning (IPL) can influence affective domain development of students, through teaching activities that facilitate learning with, from and about other professions. Current quantitative evidence offers limited explanation of how this learning is achieved within IPL programmes. This original paper tests a conceptual framework drawn from theories on IPL and affective domain development (attitudes, values and behaviours) to explain what works for whom, when and in what circumstances. Methods: The objectives of the study were twofold: to evaluate the impact of the IPL programme on the student’s attitudes and values, and identify behaviour changes in clinical practice towards interprofessional working. Using an action research approach, based in practice, an IPL programme was delivered over six weeks. Students from five professional disciplines: nursing, radiography, physiotherapy, social work, and podiatry (n=63) participated over the two action research cycles and in semi structured focus groups (n=37). Results: The recorded personal experiences of the IPL activities on the students were examined in relation to the: type of activity; impact on the affective domain of learning (attitude, value, or behaviour) and self-reported outcome on application to their practice. Modification in affective domain development was measured to identification or internalisation stage for 30 of the students. Self-reported outcomes on application to practice included direct impact on patient care, personal resilience building, improved communication and ability to challenge practice. Conclusion: This paper presents a conceptual framework not evident in current research, in regards to what IPL works for whom, in what circumstances and when. IPL Activities that address a personal reward or incentive and are delivered over 4 weeks, imitating ‘circles of care,’ that explore self-assessment, team building and reflection can lead to sustained change in values, attitudes and behaviours. Keywords: Action Research, Interprofessional Education, Interprofessional learning, Health and Social care, Collaboration

The Lantern, 2011-2012

• Frangipani • A Shadow • Dear Anne, In this Place, Stringbean Girls • Back to a Dandelion • How to Plant a Room • Swimming Pool Poem 30 • The Naming of Daughters • Berman Museum Photographs • Truth or Dare • The Song of Remembrance, L\u27vov, Poland, 1940 • Headlights • Prayer of Thanks • Numbers Game • Pediment • Home Sick • Lust • Sand Lining Instructions • A-A-Ask a Question • Flash Cards • Columbus Day • Mr. Yoest Gives His Report to the Police Officers on Wednesday Night • Gender Trouble • The Internet Connection at Ursinus College • Assuming You\u27ll Still be Here • 10/28/11, Third Poem • October • Actions that Affirm and Confirm Us as a Community • Why I Hate The Lantern • Confessions of an Ex-Vegetarian • Run • Lunch at Caltort • Schemers • You Will Make Beautiful Babies in America • The Black Dirt Region • Il Travatore • Ghost Story • Blue Eyes and Sunny Skies • A Little Sincerity • The Bookstore • The Opposite of Serendipity • The Human Doll • Evil Deeds • Francesca • Sunday Morning • Jersey Aesthetic • Jump! • Behind Reimert • Seaweed in New Zealand • Tombee de L\u27elegance • The Window • Esperando • Rainbow to the Heavens • Encased • In Springtime • A Fiesolan Monk\u27s Room • Inside a Bone • Neon Indian • Moments of Clarity • OneFeral: A Feral Self-Portrait • Cover Image: The Conquerorhttps://digitalcommons.ursinus.edu/lantern/1177/thumbnail.jp