164 research outputs found

    Sinking of light intruders in a shaken granular bed

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    We present an experimental study of the displacement of a light intruder immersed in a vibrated granular bed. Using high speed video we resolve the motion, during one cycle of oscillation, of a cylindrical object inside a Plexiglas box partially filled with grains. We report experimental evidence that, in the absence of convection, at least two forces are behind the intruder’s motion: an air drag force—due to the airflow through the granular bed—and a buoyancy force produced by an air-mediated granular fluid

    Effects of Leukocyte-Platelet Rich Fibrin and Nanoporous Scaffolds on Cell Proliferation and Cell Migration

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    In regenerative medicine, repair and regeneration of defects and damage in both soft and hard tissues still remain a challenge. Hence, better bioengineering strategies and biomaterials are needed. Autologous platelet concentrates are potential tools from which regenerative medicine can benefit. The Leukocyte Platelet Rich Fibrin (L-PRF) is a subfamily of the PRF concentrates that has been in the spotlight because of its simplicity. The presence in its enriched solid three-dimensional fibrin matrix of leukocytes, proteins, cytokines, growth factors, and stem cells give this biomaterial angiogenic, osteogenic, hemostatic, anti-inflammatory, antimicrobial, analgesic, and wound healing properties. Polymeric substances, such as PLGA have demonstrated potential to operate as a scaffold for bone volume augmentation. The ability to tailor the material's properties at the molecular level is one the benefits that allow these materials to be used as proper scaffolds for cells

    Assessment of bleeding events in patients receiving DOACs with or without statins to treat venous thromboembolism: insights from the RIETE registry.

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    To evaluate the impact of coadministering statins with direct oral anticoagulants (DOACs) on the risk of major bleeding events in patients with venous thromboembolism (VTE). Observational cohort analysis based on a multicentre international registry. Data were extracted from the Registro Informatizado de Enfermedad TromboEmbolica Registry, which involves 205 centres across 27 countries. A total of 73 659 patients diagnosed with VTE were classified based on their anticoagulant therapy (DOACs) versus low-molecular-weight heparin (LMWH) or vitamin K antagonists (VKAs) and concurrent use of statins. Multivariable Cox proportional hazards models adjusted for confounding variables to assess the risk of major bleeding events stratified by the type of anticoagulant use and statin use. From October 2013 to February 2023, 73 659 patients were recruited: 2573 were statin users on DOACs, 14 090 were statin users on LMWH or VKA therapy, 10 088 were non-statin users on DOACs and 46 908 were non-statin users on LMWH or VKA therapy. Statin users were 10 years older and more likely to have hypertension, diabetes, renal failure or prior artery disease. During anticoagulation (median, 187 days), 1917 patients (2.6%) suffered major bleeding. Rates of major bleeding per 100 patient-years were 2.33 (95% CI 1.72 to 3.09), 3.75 (95% CI 3.43 to 4.10), 1.39 (95% CI 1.13 to 1.69) and 3.10 (95% CI 2.93 to 3.27), respectively. On multivariable analysis, patients treated with DOACs had a significantly lower risk of major bleeding compared with those on LMWH or VKA therapy (adjusted HR 0.59; 95% CI 0.48 to 0.74). The adjusted HR in statin users versus non-users was 1.03 (95% CI 0.92 to 1.14), while in statin users on DOACs versus the rest of patients, it was 1.18 (95% CI 0.79 to 1.76). In patients with VTE receiving statins, long-term anticoagulation with DOACs was associated with a reduced risk of major bleeding, regardless of the statin use. These findings support the safety profile of DOACs over VKAs or LMWH in the management of VTE in patients requiring statins

    Topological analysis of tapped granular media using persistent homology

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    We use the first Betti number of a complex to analyze the morphological structure of granular samples in mechanical equilibrium. We investigate two-dimensional granular packings after a tapping process by means of both simulations and experiments. States with equal packing fraction obtained with different tapping intensities are distinguished after the introduction of a filtration parameter which determines the particles (nodes in the network) that are joined by an edge. This is accomplished by just using the position of the particles obtained experimentally and no other information about the possible contacts, or magnitude of force

    Bacterial and fungal microflora in surgically removed lung cancer samples

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    <p>Abstract</p> <p>Background</p> <p>Clinical and experimental data suggest an association between the presence of bacterial and/or fungal infection and the development of different types of cancer, independently of chemotherapy-induced leukopenia. This has also been postulated for the development of lung cancer, however the prevalence and the exact species of the bacteria and fungi implicated, have not yet been described.</p> <p>Aim</p> <p>To determine the presence of bacterial and fungal microflora in surgically extracted samples of patients with lung cancer.</p> <p>Materials and methods</p> <p>In this single-center prospective, observational study, tissue samples were surgically extracted from 32 consecutive patients with lung cancer, and reverse-transcription polymerase chain reaction (RT-PCR) was used to identify the presence of bacteria and fungi strains.</p> <p>Results</p> <p>The analysis of the electrophoresis data pointed out diversity between the samples and the strains that were identified. Mycoplasma strains were identified in all samples. Strains that appeared more often were Staphylococcus epidermidis, Streptococcus mitis and Bacillus strains, followed in descending frequency by Chlamydia, Candida, Listeria, and Haemophilus influenza. In individual patients Legionella pneumophila and Candida tropicalis were detected.</p> <p>Conclusions</p> <p>A diversity of pathogens could be identified in surgically extracted tissue samples of patients with lung cancer, with mycoplasma strains being present in all samples. These results point to an etiologic role for chronic infection in lung carcinogenesis. Confirmation of these observations and additional studies are needed to further characterize the etiologic role of inflammation in lung carcinogenesis.</p

    Pulmonary tuberculosis and lung cancer: simultaneous and sequential occurrence

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    OBJECTIVE: Lung cancer (LC) is the leading cause of cancer-related death and represents a major public health problem worldwide. Another major cause of morbidity and mortality, especially in developing countries, is tuberculosis. The simultaneous or sequential occurrence of pulmonary tuberculosis and LC in the same patient has been reported in various case series and case-control studies. The objective of this study was to describe the characteristics of patients developing tuberculosis and LC, either simultaneously or sequentially. METHODS: This was a cross-sectional study based on the review of medical charts. RESULTS: The study involved 24 patients diagnosed with tuberculosis and LC between 2009 and 2012. The diagnoses of tuberculosis and LC occurred simultaneously in 10 patients, whereas tuberculosis was diagnosed prior to LC in 14. The median time between the two diagnoses was 5 years (interquartile range: 1-30 years). Fourteen patients (58.3%) were male, 20 (83.3%) were White, and 22 (91.7%) were smokers or former smokers. The most common histological type was adenocarcinoma, identified in 14 cases (58.3%), followed by epidermoid carcinoma, identified in 6 (25.0%). Seven patients (29.2%) presented with distant metastases at diagnosis; of those 7 patients, 5 (71%) were diagnosed with LC and tuberculosis simultaneously. CONCLUSIONS: In the present study, most of the patients with tuberculosis and LC were smokers or former smokers, and tuberculosis was diagnosed either before or simultaneously with LC. Non-small cell lung cancer, especially adenocarcinoma, was the most common histological type

    Protandim, a Fundamentally New Antioxidant Approach in Chemoprevention Using Mouse Two-Stage Skin Carcinogenesis as a Model

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    Oxidative stress is an important contributor to cancer development. Consistent with that, antioxidant enzymes have been demonstrated to suppress tumorigenesis when being elevated both in vitro and in vivo, making induction of these enzymes a more potent approach for cancer prevention. Protandim, a well-defined combination of widely studied medicinal plants, has been shown to induce superoxide dismutase (SOD) and catalase activities and reduce superoxide generation and lipid peroxidation in healthy human subjects. To investigate whether Protandim can suppress tumor formation by a dietary approach, a two-stage mouse skin carcinogenesis study was performed. At the end of the study, the mice on a Protandim-containing basal diet had similar body weight compared with those on the basal diet, which indicated no overt toxicity by Protandim. After three weeks on the diets, there was a significant increase in the expression levels of SOD and catalase, in addition to the increases in SOD activities. Importantly, at the end of the carcinogenesis study, both skin tumor incidence and multiplicity were reduced in the mice on the Protandim diet by 33% and 57% respectively, compared with those on basal diet. Biochemical and histological studies revealed that the Protandim diet suppressed tumor promoter-induced oxidative stress (evidenced by reduction of protein carbonyl levels), cell proliferation (evidenced by reduction of skin hyperplasia and suppression of PKC/JNK/Jun pathway), and inflammation (evidenced by reduction of ICAM-1/VCAM-1 expression, NF-κB binding activity, and nuclear p65/p50 levels). Overall, induction of antioxidant enzymes by Protandim may serve as a practical and potent approach for cancer prevention

    Pharmacological Blockade of Serotonin 5-HT7 Receptor Reverses Working Memory Deficits in Rats by Normalizing Cortical Glutamate Neurotransmission

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    The role of 5-HT7 receptor has been demonstrated in various animal models of mood disorders; however its function in cognition remains largely speculative. This study evaluates the effects of SB-269970, a selective 5-HT7 antagonist, in a translational model of working memory deficit and investigates whether it modulates cortical glutamate and/or dopamine neurotransmission in rats. The effect of SB-269970 was evaluated in the delayed non-matching to position task alone or in combination with MK-801, a non-competitive NMDA receptor antagonist, and, in separate experiments, with scopolamine, a non-selective muscarinic antagonist. SB-269970 (10 mg/kg) significantly reversed the deficits induced by MK-801 (0.1 mg/kg) but augmented the deficit induced by scopolamine (0.06 mg/kg). The ability of SB-269970 to modulate MK-801-induced glutamate and dopamine extracellular levels was separately evaluated using biosensor technology and microdialysis in the prefrontal cortex of freely moving rats. SB-269970 normalized MK-801 -induced glutamate but not dopamine extracellular levels in the prefrontal cortex. Rat plasma and brain concentrations of MK-801 were not affected by co-administration of SB-269970, arguing for a pharmacodynamic rather than a pharmacokinetic mechanism. These results indicate that 5-HT7 receptor antagonists might reverse cognitive deficits associated with NMDA receptor hypofunction by selectively normalizing glutamatergic neurotransmission

    Previous Lung Diseases and Lung Cancer Risk: A Systematic Review and Meta-Analysis

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    In order to review the epidemiologic evidence concerning previous lung diseases as risk factors for lung cancer, a meta-analysis and systematic review was conducted.Relevant studies were identified through MEDLINE searches. Using random effects models, summary effects of specific previous conditions were evaluated separately and combined. Stratified analyses were conducted based on smoking status, gender, control sources and continent.A previous history of COPD, chronic bronchitis or emphysema conferred relative risks (RR) of 2.22 (95% confidence interval (CI): 1.66, 2.97) (from 16 studies), 1.52 (95% CI: 1.25, 1.84) (from 23 studies) and 2.04 (95% CI: 1.72, 2.41) (from 20 studies), respectively, and for all these diseases combined 1.80 (95% CI: 1.60, 2.11) (from 39 studies). The RR of lung cancer for subjects with a previous history of pneumonia was 1.43 (95% CI: 1.22-1.68) (from 22 studies) and for subjects with a previous history of tuberculosis was 1.76 (95% CI=1.49, 2.08), (from 30 studies). Effects were attenuated when restricting analysis to never smokers only for COPD/emphysema/chronic bronchitis (RR=1.22, 0.97-1.53), however remained significant for pneumonia 1.36 (95% CI: 1.10, 1.69) (from 8 studies) and tuberculosis 1.90 (95% CI: 1.45, 2.50) (from 11 studies).Previous lung diseases are associated with an increased risk of lung cancer with the evidence among never smokers supporting a direct relationship between previous lung diseases and lung cancer
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