3,838 research outputs found

    Surfactant effect in heteroepitaxial growth. The Pb - Co/Cu(111) case

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    A MonteCarlo simulations study has been performed in order to study the effect of Pb as surfactant on the initial growth stage of Co/Cu(111). The main characteristics of Co growing over Cu(111) face, i.e. the decorated double layer steps, the multiple layer islands and the pools of vacancies, disappear with the pre-evaporation of a Pb monolayer. Through MC simulations, a full picture of these complex processes is obtained. Co quickly diffuses through the Pb monolayer exchanging place with Cu atoms at the substrate. The exchange process diffusion inhibits the formation of pure Co islands, reducing the surface stress and then the formation of multilayer islands and the pools of vacancies. On the other hand, the random exchange also suppress the nucleation preferential sites generated by Co atoms at Cu steps, responsible of the step decoration.Comment: 4 pages, latex, 2 figures embedded in the tex

    Unraveling Differences in Molecular Mechanisms and Immunological Contrasts between Squamous Cell Carcinoma and Adenocarcinoma of the Cervix

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    This study aims to refine our understanding of the inherent heterogeneity in cervical cancer by exploring differential gene expression profiles, immune cell infiltration dynamics, and implicated signaling pathways in the two predominant histological types of cervix carcinoma, Squamous Cell Carcinoma (SCC) and Adenocarcinoma (ADC). Targeted gene expression data that were previously generated from samples of primary cervical cancer were re-analyzed. The samples were grouped based on their histopathology, comparing SCC to ADC. Each tumor in the study was confirmed to be high risk human papilloma virus (hrHPV) positive. A total of 21 cervical cancer samples were included, with 11 cases of SCC and 10 of ADC. Data analysis revealed a total of 26 differentially expressed genes, with 19 genes being overexpressed in SCC compared to ADC (Benjamini–Hochberg (BH)-adjusted p-value &lt; 0.05). Importantly, the immune checkpoint markers CD274 and CTLA4 demonstrated significantly higher expression in SCC compared to ADC. In addition, SCC showed a higher infiltration of immune cells, including B and T cells, and cytotoxic cells. Higher activation of a variety of pathways was found in SCC samples including cytotoxicity, interferon signaling, metabolic stress, lymphoid compartment, hypoxia, PI3k-AKT, hedgehog signaling and Notch signaling pathways. Our findings show distinctive gene expression patterns, signaling pathway activations, and trends in immune cell infiltration between SCC and ADC in cervical cancer. This study underscores the heterogeneity within primary cervical cancer, emphasizing the potential benefits of subdividing these tumours based on histological and molecular differences.</p

    The Highest Resolution Chandra View of Photoionization and Jet-Cloud Interaction in the Nuclear Region of NGC 4151

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    We report high resolution imaging of the nucleus of the Seyfert 1 galaxy NGC 4151 obtained with a 50 ks Chandra HRC observation. The HRC image resolves the emission on spatial scales of 0.5", ~30 pc, showing an extended X-ray morphology overall consistent with the narrow line region (NLR) seen in optical line emission. Removal of the bright point-like nuclear source and image deconvolution techniques both reveal X-ray enhancements that closely match the substructures seen in the Hubble Space Telescope [OIII] image and prominent knots in the radio jet. We find that most of the NLR clouds in NGC 4151 have [OIII] to soft X-ray ratio ~10, despite the distance of the clouds from the nucleus. This ratio is consistent with the values observed in NLRs of some Seyfert 2 galaxies, which indicates a uniform ionization parameter even at large radii and a density decreasing as r2r^{-2} as expected for a nuclear wind scenario. The [OIII]/X-ray ratios at the location of radio knots show an excess of X-ray emission, suggesting shock heating in addition to photoionization. We examine various mechanisms for the X-ray emission and find that, in contrast to jet-related X-ray emission in more powerful AGN, the observed jet parameters in NGC 4151 are inconsistent with synchrotron emission, synchrotron self-Compton, inverse Compton of CMB photons or galaxy optical light. Instead, our results favor thermal emission from the interaction between radio outflow and NLR gas clouds as the origin for the X-ray emission associated with the jet. This supports previous claims that frequent jet-ISM interaction may explain why jets in Seyfert galaxies appear small, slow, and thermally dominated, distinct from those kpc scale jets in the radio galaxies.Comment: Accepted for publication in ApJ. 28 pages, 9 figures, 3 table

    Lateral Trunk Motion and Knee Pain in Osteoarthritis of the Knee: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Patients with osteoarthritis of the knee may change their gait in an attempt to reduce loading of the affected knee, thereby reducing pain. Especially changes in lateral trunk motion may be potentially effective, since these will affect the position of the centre of mass relative to the knee, enabling minimization of the load on the knee and thereby knee pain. The aim of the study was to test the hypothesis that a higher level of knee pain is associated with higher lateral trunk motion in patients with knee OA.</p> <p>Methods</p> <p>Fifty-two patients with OA of the knee were tested. Lateral trunk motion was measured during the stance phase of walking with an optoelectronic motion analysis system and a force plate. Knee pain was measured with the VAS and the WOMAC pain questionnaire. Regression analyses were performed to assess the relationship between lateral trunk motion and knee pain.</p> <p>Results</p> <p>It was shown that in bivariate analyses knee pain was not associated with lateral trunk motion. In regression analyses, pain was associated with more lateral trunk motion. In addition, more lateral trunk motion was associated with younger age, being female, higher self-reported knee stiffness and higher maximum walking speed.</p> <p>Conclusion</p> <p>Pain is associated with lateral trunk motion. This association is weak and is influenced by age, gender, self-reported stiffness and maximum walking speed.</p

    Structure-based exploration and pharmacological evaluation of N-substituted piperidin-4-yl-methanamine CXCR4 chemokine receptor antagonists

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    Using the available structural information of the chemokine receptor CXCR4, we present hit finding and hit exploration studies that make use of virtual fragment screening, design, synthesis and structure-activity relationship (SAR) studies. Fragment 2 was identified as virtual screening hit and used as a starting point for the exploration of 31 N-substituted piperidin-4-yl-methanamine derivatives to investigate and improve the interactions with the CXCR4 binding site. Additionally, subtle structural ligand changes lead to distinct interactions with CXCR4 resulting in a full to partial displacement of CXCL12 binding and competitive and/or non-competitive antagonism. Three-dimensional quantitative structure-activity relationship (3D-QSAR) and binding model studies were used to identify important hydrophobic interactions that determine binding affinity and indicate key ligand-receptor interactions

    The efficacy of topical imiquimod in high-grade cervical intraepithelial neoplasia:A systematic review and meta-analysis

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    Objective: A major side effect of cervical excision for high-grade cervical intraepithelial neoplasia (CIN) is premature birth. A non-invasive treatment for reproductive age women is warranted. The aim of the present study was to determine the efficacy of topical imiquimod in the treatment of high-grade CIN, defined as a regression to ≤CIN 1, and to determine the clearance rate of high-risk human papillomavirus (hr-HPV), compared with surgical treatment and placebo. Methods: Databases were searched for articles from their inception to February 2023.The study protocol number was INPLASY2022110046. Original studies reporting the efficacy of topical imiquimod in CIN 2, CIN 3 or persistent hr-HPV infections were included. The study followed the Preferred Reporting Items for Systematic Reviews and Meta-analyses checklist. Results: Five studies were included (n = 463). Histological regression to ≤CIN 1 was 55% in imiquimod versus 29% in placebo, and 93% in surgical treatment. Imiquimod-treated women had a greater odds of histological regression to ≤CIN 1 than placebo (odds ratio [OR] 4.17, 95% confidence interval [CI] 2.03–8.54). In comparison to imiquimod, surgical treatment had an OR of 14.81(95% CI 6.59–33.27) for histological regression to ≤CIN 1. The hr-HPV clearance rate was 53.4% after imiquimod and 66% after surgical treatment (95% CI 0.62–23.77). Conclusions: The histological regression rate is highest for surgical treatment followed by imiquimod treatment and placebo.</p

    Delay and Impairment in Brain Development and Function in Rat Offspring After Maternal Exposure to Methylmercury

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    Maternal exposure to the neurotoxin methylmercury (MeHg) has been shown to have adverse effects on neural development of the offspring in man. Little is known about the underlying mechanisms by which MeHg affects the developing brain. To explore the neurodevelopmental defects and the underlying mechanism associated with MeHg exposure, the cerebellum and cerebrum of Wistar rat pups were analyzed by [F-18]FDG PET functional imaging, field potential analysis, and microarray gene expression profiling. Female rat pups were exposed to MeHg via maternal diet during intrauterinal and lactational period (from gestational day 6 to postnatal day (PND)10), and their brain tissues were sampled for the analysis at weaning (PND18-21) and adulthood (PND61-70). The [F-18]FDG PET imaging and field potential analysis suggested a delay in brain activity and impaired neural function by MeHg. Genome-wide transcriptome analysis substantiated these findings by showing (1) a delay in the onset of gene expression related to neural development, and (2) alterations in pathways related to both structural and functional aspects of nervous system development. The latter included changes in gene expression of developmental regulators, developmental phase associated genes, small GTPase signaling molecules, and representatives of all processes required for synaptic transmission. These findings were observed at dose levels at which only marginal changes in conventional developmental toxicity endpoints were detected. Therefore, the approaches applied in this study are promising in terms of yielding increased sensitivity compared with classical developmental toxicity tests

    Pharmacokinetic considerations and recommendations in palliative care, with focus on morphine, midazolam and haloperidol

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    Introduction: A variety of medications are used for symptom control in palliative care, such as morphine, midazolam and haloperidol. The pharmacokinetics of these drugs may be altered in these patients as a result of physiological changes that occur at the end stage of life. Areas covered: This review gives an overview of how the pharmacokinetics in terminally ill patients may differ from the average population and discusses the effect of terminal illness on each of the four pharmacokinetic processes absorption, distribution, metabolism, and elimination. Specific considerations are also given for three commonly prescribed drugs in palliative care: morphine, midazolam and haloperidol). Expert opinion: The pharmacokinetics of drugs in terminally ill patients can be complex and limited evidence exists on guided drug use in this population. To improve the quality of life of these patients, more knowledge and more pharmacokinetic/pharmacodynamics studies in terminally ill patients are needed to develop individualised dosin
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