2,162 research outputs found

    Detecting temporal and spatial effects of epithelial cancers with Raman spectroscopy.

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    PublishedJournal ArticleResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov'tThis is the final version of the article. Available from Hindawi Publishing Corporation via the DOI in this record.Epithelial cancers, including those of the skin and cervix, are the most common type of cancers in humans. Many recent studies have attempted to use Raman spectroscopy to diagnose these cancers. In this paper, Raman spectral markers related to the temporal and spatial effects of cervical and skin cancers are examined through four separate but related studies. Results from a clinical cervix study show that previous disease has a significant effect on the Raman signatures of the cervix, which allow for near 100% classification for discriminating previous disease versus a true normal. A Raman microspectroscopy study showed that Raman can detect changes due to adjacent regions of dysplasia or HPV that cannot be detected histologically, while a clinical skin study showed that Raman spectra may be detecting malignancy associated changes in tissues surrounding nonmelanoma skin cancers. Finally, results of an organotypic raft culture study provided support for both the skin and the in vitro cervix results. These studies add to the growing body of evidence that optical spectroscopy, in this case Raman spectral markers, can be used to detect subtle temporal and spatial effects in tissue near cancerous sites that go otherwise undetected by conventional histology.The authors acknowledge the financial support of the NCI/NIH (R01-CA95405 and R21-CA95995), as well as the Howard Hughes Medical Institute (pre-doctoral fellowship for MK). We would also like to thank the doctors and staff at Vanderbilt University Medical Center and Tri-state Women’s Health for all their assistance

    The fate of the homoctenids (Tentaculitoidea) during the Frasnian-Famennian mass extinction (Late Devonian)

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    The homoctenids (Tentaculitoidea) are small, conical-shelled marine animals which are amongst the most abundant and widespread of all Late Devonian fossils. They were a principal casualty of the Frasnian-Famennian (F-F, Late Devonian) mass extinction, and thus provide an insight into the extinction dynamics. Despite their abundance during the Late Devonian, they have been largely neglected by extinction studies. A number of Frasnian-Famennian boundary sections have been studied, in Poland, Germany, France, and the United States. These sections have yielded homoctenids, which allow precise recognition of the timing of the mass extinction. It is clear that the homoctenids almost disappear from the fossil record during the latest Frasnian “Upper Kellwasser Event”. The coincident extinction of this pelagic group, and the widespread development of intense marine anoxia within the water column, provides a causal link between anoxia and the F-F extinction. Most notable is the sudden demise of a group, which had been present in rock-forming densities, during this anoxic event. One new species, belonging to Homoctenus is described, but is not formally named here

    Improvement in the Electrical Properties of Nickel-Plated Steel Using Graphitic Carbon Coatings

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    Thin layers of highly conductive graphitic carbon are deposited onto nickel‐plated steel substrates using a direct photothermal chemical vapor deposition (PTCVD) technique. The coated nickel‐plated steel substrates improve electrical properties (sheet resistance and interfacial contact resistance [ICR]) compared with pristine nickel‐plated steel, which makes it a cost‐effective alternative to stainless steel for steel producers to use in high‐end electrical applications such as energy storage and microelectronics. The coated nickel‐plated steel is found to have ≈10% reduction in sheet resistance and 200 times reduction in ICR (under compression at 140 N cm−2), compared with pristine nickel‐plated steel. ICR is also three times lower than that of a benchmark gold‐coated stainless steel equivalent at the same pressure

    Monotonicity of Fitness Landscapes and Mutation Rate Control

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    A common view in evolutionary biology is that mutation rates are minimised. However, studies in combinatorial optimisation and search have shown a clear advantage of using variable mutation rates as a control parameter to optimise the performance of evolutionary algorithms. Much biological theory in this area is based on Ronald Fisher's work, who used Euclidean geometry to study the relation between mutation size and expected fitness of the offspring in infinite phenotypic spaces. Here we reconsider this theory based on the alternative geometry of discrete and finite spaces of DNA sequences. First, we consider the geometric case of fitness being isomorphic to distance from an optimum, and show how problems of optimal mutation rate control can be solved exactly or approximately depending on additional constraints of the problem. Then we consider the general case of fitness communicating only partial information about the distance. We define weak monotonicity of fitness landscapes and prove that this property holds in all landscapes that are continuous and open at the optimum. This theoretical result motivates our hypothesis that optimal mutation rate functions in such landscapes will increase when fitness decreases in some neighbourhood of an optimum, resembling the control functions derived in the geometric case. We test this hypothesis experimentally by analysing approximately optimal mutation rate control functions in 115 complete landscapes of binding scores between DNA sequences and transcription factors. Our findings support the hypothesis and find that the increase of mutation rate is more rapid in landscapes that are less monotonic (more rugged). We discuss the relevance of these findings to living organisms

    Dose-dependent effects of Allopurinol on human foreskin fibroblast cell and human umbilical vein endothelial cell under hypoxia

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    Allopurinol, an inhibitor of xanthine oxidase, has been used in clinical trials of patients with cardiovascular and chronic kidney disease. These are two pathologies with extensive links to hypoxia and activation of the transcription factor hypoxia inducible factor (HIF) family. Here we analysed the effects of allopurinol treatment in two different cellular models, and their response to hypoxia. We explored the dose-dependent effect of allopurinol on Human Foreskin Fibroblasts (HFF) and Human Umbilical Vein Endothelial Cells (HUVEC) under hypoxia and normoxia. Under normoxia and hypoxia, high dose allopurinol reduced the accumulation of HIF-1α protein in HFF and HUVEC cells. Allopurinol had only marginal effects on HIF-1α mRNA level in both cellular systems. Interestingly, allopurinol effects over the HIF system were independent of prolyl-hydroxylase activity. Finally, allopurinol treatment reduced angiogenesis traits in HUVEC cells in an in vitro model. Taken together these results indicate that high doses of allopurinol inhibits the HIF system and pro-angiogenic traits in cells

    Abundance of Early Functional HIV-Specific CD8+ T Cells Does Not Predict AIDS-Free Survival Time

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    Background T-cell immunity is thought to play an important role in controlling HIV infection, and is a main target for HIV vaccine development. HIV-specific central memory CD8+ and CD4+ T cells producing IFNγ and IL-2 have been associated with control of viremia and are therefore hypothesized to be truly protective and determine subsequent clinical outcome. However, the cause-effect relationship between HIV-specific cellular immunity and disease progression is unknown. We investigated in a large prospective cohort study involving 96 individuals of the Amsterdam Cohort Studies with a known date of seroconversion whether the presence of cytokine-producing HIV-specific CD8+ T cells early in infection was associated with AIDS-free survival time. Methods and Findings The number and percentage of IFNγ and IL-2 producing CD8+ T cells was measured after in vitro stimulation with an overlapping Gag-peptide pool in T cells sampled approximately one year after seroconversion. Kaplan-Meier survival analysis and Cox proportional hazard models showed that frequencies of cytokine-producing Gag-specific CD8+ T cells (IFNγ, IL-2 or both) shortly after seroconversion were neither associated with time to AIDS nor with the rate of CD4+ T-cell decline. Conclusions These data show that high numbers of functional HIV-specific CD8+ T cells can be found early in HIV infection, irrespective of subsequent clinical outcome. The fact that both progressors and long-term non-progressors have abundant T cell immunity of the specificity associated with low viral load shortly after seroconversion suggests that the more rapid loss of T cell immunity observed in progressors may be a consequence rather than a cause of disease progression

    Modelling the Innate Immune Response against Avian Influenza Virus in Chicken

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    At present there is limited understanding of the host immune response to (low pathogenic) avian influenza virus infections in poultry. Here we develop a mathematical model for the innate immune response to avian influenza virus in chicken lung, describing the dynamics of viral load, interferon-α, -β and -γ, lung (i.e. pulmonary) cells and Natural Killer cells. We use recent results from experimentally infected chickens to validate some of the model predictions. The model includes an initial exponential increase of the viral load, which we show to be consistent with experimental data. Using this exponential growth model we show that the duration until a given viral load is reached in experiments with different inoculation doses is consistent with a model assuming a linear relationship between initial viral load and inoculation dose. Subsequent to the exponential-growth phase, the model results show a decline in viral load caused by both target-cell limitation as well as the innate immune response. The model results suggest that the temporal viral load pattern in the lungs displayed in experimental data cannot be explained by target-cell limitation alone. For biologically plausible parameter values the model is able to qualitatively match to data on viral load in chicken lungs up until approximately 4 days post infection. Comparison of model predictions with data on CD107-mediated degranulation of Natural Killer cells yields some discrepancy also for earlier days post infection

    PENGARUH PROFITABILITAS, STRUKTUR MODAL DAN PERTUMBUHAN PENJUALAN TERHADAP RETURN SAHAM (Studi pada Perusahaan Sektor Manufaktur Subsektor Makanan dan Minuman yang Terdaftar di BEI 2018-2022)

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    ABSTRAK Kemajuan perekonomian suatu negara salah satunya dapat direfleksikan oleh aktivitas pasar modal yang ada di negara tersebut. Sebagai pasar yang sedang berkembang, pergerakan harga saham di pasar modal Indonesia berfluktuatif relatif tinggi. Penelitian ini merupakan gabungan dari penelitian sebelumnya yang dilakukan oleh Endri (2019) dengan variabel profitabilitas, Bhagyalakshmi (2020) dengan variabel struktur modal dan Thomas (2022) dengan variabel sales growth. penelitian mengenai “Pengaruh Profitabilitas, Struktur Modal dan Pertumbuhan Penjualan Terhadap Return Saham (Studi pada Perusahaan Sektor Manufaktur Subsektor Makanan dan Minuman yang Terdaftar di BEI 2018-2022)”. Penelitian ini bertujuan mengetahui bagaimana profitabilitas, struktur modal, pertumbuhan penjualan pada Perusahaan Sektor Makanan dan Minuman yang terdaftar di Bursa Efek Indonesia (BEI) periode 2018-2022 serta bagaimana pengaruhnya terhadap return saham. Perusahaan Manufaktur Sub Sektor Makanan dan Minuman yang terdaftar di Bursa Efek Indonesia (BEI) Tahun 2018-2022 merupakan unit dari penelitian ini dengan variabel dependen nya yaity profitabilitas, stuktur modal dan pertumbuhan penjualan dan variabel dependenya yaitu return saham. Hasil analisis pada penelitian ini menujukan Profitabilitas, stuktur modal masuk ke dalam kategori Rendah dengan memiliki pengaruh positif dan signifikan terhadap return saham sedangkan Pertumbuhan Penjualan masuk ke dalam kategori Cukup baik dengan memiliki pengaruh positif dan signifikan terhadap return saham. Kata Kunci: Profitabilitas, Struktur Modal, Pertumbuhan Penjualan, Return Saham, BE
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