752 research outputs found

    Semiclassical time--dependent propagation in three dimensions: How accurate is it for a Coulomb potential?

    Full text link
    A unified semiclassical time propagator is used to calculate the semiclassical time-correlation function in three cartesian dimensions for a particle moving in an attractive Coulomb potential. It is demonstrated that under these conditions the singularity of the potential does not cause any difficulties and the Coulomb interaction can be treated as any other non-singular potential. Moreover, by virtue of our three-dimensional calculation, we can explain the discrepancies between previous semiclassical and quantum results obtained for the one-dimensional radial Coulomb problem.Comment: 8 pages, 4 figures (EPS

    Explant-derived human dental pulp stem cells enhance differentiation and proliferation potentials

    Full text link
    Numerous stem cell niches are present in the different tissues and organs of the adult human body. Among these tissues, dental pulp, entrapped within the 'sealed niche' of the pulp chamber, is an extremely rich site for collecting stem cells. In this study, we demonstrate that the isolation of human dental pulp stem cells by the explants culture method (hD-DPSCs) allows the recovery of a population of dental mesenchymal stem cells that exhibit an elevated proliferation potential. Moreover, we highlight that hD-DPSCs are not only capable of differentiating into osteoblasts and chondrocytes but are also able to switch their genetic programme when co-cultured with murine myoblasts. High levels of MyoD expression were detected, indicating that muscle-specific genes in dental pulp cells can be turned on through myogenic fusion, confirming thus their multipotency. A perivascular niche may be the potential source of hD-DPSCs, as suggested by the consistent Ca(2+) release from these cells in response to endothelin-1 (ET-1) treatment, which is also able to significantly increase cell proliferation. Moreover, response to ET-1 has been found to be superior in hD-DPSCs than in DPSCs, probably due to the isolation method that promotes release of stem/progenitor cells from perivascular structures. The ability to isolate, expand and direct the differentiation of hD-DPSCs into several lineages, mainly towards myogenesis, offers an opportunity for the study of events associated with cell commitment and differentiation. Therefore, hD-DPSCs display enhanced differentiation abilities when compared to DPSCs, and this might be of relevance for their use in therapy

    An evaluation of metal removal during wastewater treatment: The potential to achieve more stringent final effluent standards

    Get PDF
    This is the author's accepted manuscript. The final published article is available from the link below. Copyright @ 2011 Taylor & Francis.Metals are of particular importance in relation to water quality, and concern regarding the impact of these contaminants on biodiversity is being encapsulated within the latest water-related legislation such as the Water Framework Directive in Europe and criteria revisions to the Clean Water Act in the United States. This review undertakes an evaluation of the potential of 2-stage wastewater treatment consisting of primary sedimentation and biological treatment in the form of activated sludge processes, to meet more stringent discharge consents that are likely to be introduced as a consequence. The legislation, sources of metals, and mechanisms responsible for their removal are discussed, to elucidate possible pathways by which the performance of conventional processes may be optimized or enhanced. Improvements in effluent quality, achievable by reducing concentrations of suspended solids or biochemical oxygen demand, may also reduce metal concentrations although meeting possible requirements for the removal of copper my be challenging

    Prospects for the development of odour baits to control the tsetse flies Glossina tachinoides and G. palpalis s.l.

    Get PDF
    Field studies were done of the responses of Glossina palpalis palpalis in Côte d'Ivoire, and G. p. gambiensis and G. tachinoides in Burkina Faso, to odours from humans, cattle and pigs. Responses were measured either by baiting (1.) biconical traps or (2.) electrocuting black targets with natural host odours. The catch of G. tachinoides from traps was significantly enhanced (~5×) by odour from cattle but not humans. In contrast, catches from electric targets showed inconsistent results. For G. p. gambiensis both human and cattle odour increased (>2×) the trap catch significantly but not the catch from electric targets. For G. p. palpalis, odours from pigs and humans increased (~5×) the numbers of tsetse attracted to the vicinity of the odour source but had little effect on landing or trap-entry. For G. tachinoides a blend of POCA (P = 3-n-propylphenol; O = 1-octen-3-ol; C = 4-methylphenol; A = acetone) alone or synthetic cattle odour (acetone, 1-octen-3-ol, 4-methylphenol and 3-n-propylphenol with carbon dioxide) consistently caught more tsetse than natural cattle odour. For G. p. gambiensis, POCA consistently increased catches from both traps and targets. For G. p. palpalis, doses of carbon dioxide similar to those produced by a host resulted in similar increases in attraction. Baiting traps with super-normal (~500 mg/h) doses of acetone also consistently produced significant but slight (~1.6×) increases in catches of male flies. The results suggest that odour-baited traps and insecticide-treated targets could assist the AU-Pan African Tsetse and Trypanosomiasis Eradication Campaign (PATTEC) in its current efforts to monitor and control Palpalis group tsetse in West Africa. For all three species, only ~50% of the flies attracted to the vicinity of the trap were actually caught by it, suggesting that better traps might be developed by an analysis of the visual responses and identification of any semiochemicals involved in short-range interaction

    Differential impact of LPG-and PG-deficient Leishmania major mutants on the immune response of human dendritic cells

    Get PDF
    <div><p>Background</p><p><i>Leishmania major</i> infection induces robust interleukin-12 (IL12) production in human dendritic cells (hDC), ultimately resulting in Th1-mediated immunity and clinical resolution. The surface of <i>Leishmania</i> parasites is covered in a dense glycocalyx consisting of primarily lipophosphoglycan (LPG) and other phosphoglycan-containing molecules (PGs), making these glycoconjugates the likely pathogen-associated molecular patterns (PAMPS) responsible for IL12 induction.</p><p>Methodology/Principal Findings</p><p>Here we explored the role of parasite glycoconjugates on the hDC IL12 response by generating <i>L</i>. <i>major</i> Friedlin V1 mutants defective in LPG alone, (FV1 <i>lpg1-</i>), or generally deficient for all PGs, (FV1 <i>lpg2-</i>). Infection with metacyclic, infective stage, <i>L</i>. <i>major</i> or purified LPG induced high levels of <i>IL12B</i> subunit gene transcripts in hDCs, which was abrogated with FV1 <i>lpg1-</i> infections. In contrast, hDC infections with FV1 <i>lpg2-</i> displayed increased <i>IL12B</i> expression, suggesting other PG-related/<i>LPG2</i> dependent molecules may act to dampen the immune response. Global transcriptional profiling comparing WT, FV1 <i>lpg1-</i>, FV1 <i>lpg2-</i> infections revealed that FV1 <i>lpg1-</i> mutants entered hDCs in a silent fashion as indicated by repression of gene expression. Transcription factor binding site analysis suggests that LPG recognition by hDCs induces IL-12 in a signaling cascade resulting in Nuclear Factor κ B (NFκB) and Interferon Regulatory Factor (IRF) mediated transcription.</p><p>Conclusions/Significance</p><p>These data suggest that <i>L</i>. <i>major</i> LPG is a major PAMP recognized by hDC to induce IL12-mediated protective immunity and that there is a complex interplay between PG-baring <i>Leishmania</i> surface glycoconjugates that result in modulation of host cellular IL12.</p></div

    Interactions between obstructive sleep apnea syndrome and insulin resistance

    Get PDF
    Previous studies have shown Obstructive Sleep Apnea (OSA) as a risk factor for development of cardiovascular and cerebrovascular disease. However, controversies remain as to whether these changes are consequences of the associated obesity or OSA itself results in endocrine and metabolic changes, including impairment of insulin sensitivity, growth hormone, secretion inflammatory cytokines alterations, activation of peripheral sympathetic activity, and hipothalamic-pituitary-adrenal (HPA) axis, that may predispose to vascular disease. Furthermore many cardiovascular risk factors, such as hypertension, obesity, insulin resistance and type 2 diabetes, are strongly associated with OSA. In this article, we will review the evidence and discuss possible mechanisms underlying these links and the pathophysiology of OSA morbidities.Estudos anteriores mostraram que pacientes com Apnéia Obstrutiva do Sono (AOS) apresentam maior risco para doenças cardiovasculares. Entretanto, permanece controverso se essa associação depende da obesidade ou se ocorre devido a alterações fisiológicas decorrentes da desordem do sono, como ativação do sistema nervoso simpático, da inflamação e desordens do eixo corticotrófico e somatotrófico, que predispõem a danos vasculares. Além disso, muitos fatores de risco para doenças cardiovasculares (DCV) estão fortemente associados ao distúrbio respiratório, entre eles hipertensão, obesidade, resistência à insulina e diabetes tipo 2 (DM2). Neste artigo, vamos discutir a interação entre resistência à insulina e AOS e os possíveis mecanismos fisiopatológicos que contribuem para suas co-morbidades.Universidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de Clínica MédicaUniversidade Federal de São Paulo (UNIFESP) Escola Paulista de Medicina Departamento de PsicobiologiaUNIFESP, EPM, Depto. de Clínica MédicaUNIFESP, EPM, Depto. de PsicobiologiaSciEL

    Penumbra indigo percutaneous aspiration thrombectomy system in the treatment of aortic endograft iliac limb occlusion: results from an Italian Multicentre Registry

    Get PDF
    Objective: This study aimed to evaluate the safety and effectiveness of the Penumbra Indigo percutaneous aspiration thrombectomy (PAT) system in the clinical presentation of iliac limb occlusion (ILO) after endovascular aortic repair (EVAR).Methods: A retrospective, observational, multicentre study conducted in eight Italian vascular centres. Consecutive patients presenting with ILO after EVAR were eligible. To assess vessel revascularisation, Thrombo-aspiration In Peripheral Ischaemia (TIPI) classification (score 0-3) was used at presentation (t1), after PAT (t2), and after adjunctive procedures (t3). Successful revascularisation was considered TIPI 2-3 (near complete or complete). Primary intra-operative outcomes were technical success (TS) of Indigo PAT and combined TS of PAT associated with adjunctive procedures when needed. Primary follow up outcomes were safety and effectiveness at one, six, and 12 months.Results: From September 2019 to December 2021, there were 48 ILO and 17 patients (35%) [median age 75 years, IQR 71, 83 years; male, 14 (82%); urgent, 8 (47%)] were treated and enrolled. The median time after primary EVAR was 24 months (IQR 0, 42 months). The median clot age from ILO diagnosis to PAT was three days (IQR 1, 12 days). Ten patients (59%) presented with limb threatening ischaemia. At t1, TIPI 0 and 1 was present in 13 (76%) and four (24%) cases, respectively. At t2, primary TS (TIPI 2-3) was achieved in 14 cases (82%) after Indigo PAT (p &lt; .001). Fifteen patients (88%) required adjunctive procedures (14 re-linings, one surgical patch angioplasty). At t3, combined TS was achieved in 16 cases (94%). Intra-operative complication included one (6%) distal embolisation, treated successfully. The 30 day mortality was one case (6%) due to pneumonia. At one, six, and 12 months, clinical success was 100% without ILO recurrence. The median follow up was 23 months (IQR 11, 41 months): at 18 months, survival and freedom from re-intervention were 91 + 8% and 90 + 9%, respectively.Conclusion: This study reports for the first time the efficacy and safety of Penumbra Indigo PAT for ILO after EVAR, with promising technical and clinical success up to one year

    First record of Rhabdoceras suessi (Ammonoidea, Late Triassic) from the Transylvanian Triassic Series of the Eastern Carpathians (Romania) and a review of its biochronology, paleobiogeography and paleoecology

    Get PDF
    Abstract The occurrence of the heteromorphic ammonoid Rhabdoceras suessi Hauer, 1860, is recorded for the first time in the Upper Triassic limestone of the Timon-Ciungi olistolith in the Rarău Syncline, Eastern Carpathians. A single specimen of Rhabdoceras suessi co-occurs with Monotis (Monotis) salinaria that constrains its occurrence here to the Upper Norian (Sevatian 1). It is the only known heteromorphic ammonoid in the Upper Triassic of the Romanian Carpathians. Rhabdoceras suessi is a cosmopolitan species widely recorded in low and mid-paleolatitude faunas. It ranges from the Late Norian to the Rhaetian and is suitable for high-resolution worldwide correlations only when it co-occurs with shorter-ranging choristoceratids, monotid bivalves, or the hydrozoan Heterastridium. Formerly considered as the index fossil for the Upper Norian (Sevatian) Suessi Zone, by the latest 1970s this species lost its key biochronologic status among Late Triassic ammonoids, and it generated a controversy in the 1980s concerning the status of the Rhaetian stage. New stratigraphic data from North America and Europe in the subsequent decades resulted in a revised ammonoid biostratigraphy for the uppermost Triassic, the Rhaetian being reinstalled as the topmost stage in the current standard timescale of the Triassic. The geographic distribution of Rhabdoceras is compiled from published worldwide records, and its paleobiogeography and paleoecology are discussed

    Simultaneous versus staged approach in transcatheter aortic valve implantation for severe stenosis and endovascular aortic repair for thoracic and abdominal aortic aneurysm

    Get PDF
    Objectives: Thoracic/abdominal aortic aneurysms and aortic stenosis may be concomitant diseases requiring both transcatheter aortic valve implantation (TAVI) and endovascular aneurysm repair (T/EVAR) in high-risk patients for surgical approaches, but temporal management is not clearly defined yet. The aim of the study was to analyse outcomes of simultaneous versus staged TAVI and T/EVAR. Methods: Retrospective observational multicentre study was performed on patients requiring TAVI and T/EVAR from 2016 to 2022. Patients were divided into 2 groups: 'Simultaneous group' if T/EVAR + TAVI were performed in the same procedure and 'Staged group' if T/EVAR and TAVI were performed in 2 steps, but within 3 months. Primary outcomes were technical success, 30-day mortality/major adverse events and follow-up survival. Secondary outcomes were procedural metrics and length of stay. Results: Forty-four cases were collected; 8 (18%) had T/EVAR and 36 (82%) had EVAR, respectively. Upon temporal determination, 25 (57%) and 19 (43%) were clustered in Simultaneous and Staged groups, respectively. In Staged group, median time between procedures was 72 (interquartile range-IQR: 57-87) days. Preoperative and intraoperative figures were similar. There was no difference in 30-day mortality (Simultaneous: 0/25 versus Staged: 1/19; P = 0.43). Pulmonary events (Simultaneous: 0/25 versus Staged: 5/19; P = 0.01) and need of postoperative cardiac pacemaker (Simultaneous: 2/25 versus Staged: 7/19; P = 0.02) were more frequent in Staged patients. The overall length of stay was lower in the Simultaneous group [Simultaneous: 7 (IQR: 6-8) versus Staged: 19 (IQR: 15-23) days; P = 0.001]. The median follow-up was 25 (IQR: 8-42) months and estimated 3-year survival was 73% with no difference between groups (Simultaneous: 82% versus Staged: 74%; P = 0.90). Conclusions: Both Simultaneous or Staged T/EVAR and TAVI procedures are effective with satisfactory outcomes. Despite the small numbers, simultaneous repair seems to reduce length of stay and pulmonary complications, maintaining similar follow-up survival
    corecore