23 research outputs found
Universal statistics of epithelial tissue topology
Cells forming various epithelial tissues have a strikingly universal distribution for the number of their edges. It is generally assumed that this topological feature is predefined by the statistics of individual cell divisions in growing tissue but existing theoretical models are unable to predict the observed distribution. Here we show experimentally, as well as in simulations, that the probability of cellular division increases exponentially with the number of edges of the dividing cell and show analytically that this is responsible for the observed shape of cell-edge distribution
Tělo v kontextu paliativnà péče: Etnografická studie
Studium humanitnĂ vzdÄ›lanosti - SpoleÄŤenskovÄ›dnĂ modulLiberal Arts and Humanities - Social Sciences ModuleFaculty of HumanitiesFakulta humanitnĂch studi
Statistical significance of curing variables on geopolymerization of mining by-product untreated clay
The focus of this research is to investigate of the possibility of reusing mineral wastes and by-products from mining processes to produce more sustainable binders in large amounts. A mining by-product consisting of halloysite (approximately 48 wt%) was used to produce dense alkali activated solids. Attention was paid to the influence of temperature on the geopolymerisation process in terms of the microstructural characteristics of the samples obtained. The challenge was to alkali activate the clay as received without any firing pre-treatment. The fresh paste of untreated clay was cured at 50% relative humidity (RH%) at different temperatures: 40, 60, and 70 °C. The halloysite-bearing powder (HC) was then mixed with a low-quartz sand, a second by-product of the mining industry, to achieve higher chemical stability. The results showed a clear difference in chemical stability for samples containing sand compared to those without sand. Low percentages of metakaolin (5–15%) were also added to the same formulations to improve the chemical and physical properties of the samples and to reduce the curing time. For mixtures consisting of untreated clay and sand only NaOH was added as alkaline activator. The effect of curing temperature, curing time and addition of metakaolin (MK) on the microstructure of the geopolymers was analysed by different techniques: measurement of pH and ionic conductivity of the eluate of the chemical stability test in water, X-ray diffraction (XRD), scanning electron microscopy (SEM), bulk density, and compressive strength. Finally, a statistical approach was adopted to rationalise the effect of the curing conditions on the consolidation of the fresh pastes of samples with the untreated HC, sand and metakaolin. To test whether the parameters of the curing process, as well as the MK addition had an influence on the values of the ionic conductivity of the eluate from water sinking and/or the density of the solid final product, a 3-way ANOVA followed by Tukey-Kramer post hoc tests (p < 0.05) were performed. To further investigate the interaction between preparation parameters and the material properties, we also built a Generalized Linear model that provided an equation to predict the final results. Overall, we found that the addition of MK significantly reduced the conductivity while only marginally increasing the density of the material. This effect was extremely temperature-dependent, and it disappeared at 70 °C. In conclusion, it has been demonstrated how the addition of fillers, an easily controllable industrial step, can maximise the performance of the consolidated material, rather than controlling the curing time and temperature conditions
La restrizione di libert\ue0 nella patogenesi dei disturbi del comportamento alimentare
Introduction. Freedom constraints in coercitive closed environments such as a jail always cause problems with sadness, loneliness, abandonment causing to a grater or lesser degree, stable depressive phenomena or general psychological uneasiness. An aspect which has been inadequately assessed up to now in literature is that of eating disorders. Such pathologies in this last twenty years have been increasingly affecting different age bands with various relational-existential problems at the individual level. Materials and methods. For this reason we have thought about observing such phenomena within structures where different aspects regarding food, body perceptions, space and above all freedom are altered. The group from us taken in examination originates from four jail of Sicily. Three tests of self-administration have been delivered: Zung for the anxiety, Zung for the depression and EDI-1 modified to 38 items. Conclusions. Our study has shown that there are some meaningful correlations between freedom restrictions regime and some dimensions that interest the pathogenesis of eating disorders. We did not find evidence of eating disorders in a narrow sense but observed changed attitudes towards food and relationships with one's own body imag
Peptide stereochemistry effects from pKa-shift to gold nanoparticle templating in a supramolecular hydrogel.
The divergent supramolecular behavior of a series of tripeptide stereoisomers was elucidated through spectroscopic, microscopic, crystallographic and computational techniques. Only two epimers were able to effectively self-organize into amphipathic structures, leading to supramolecular hydrogels or crystals, respectively. Despite the similarity between the two peptides’ turn conformations, stereoconfiguration led to different abilities to engage in intramolecular hydrogen bonding. Self-assembly further shifted the pKa of the C-terminal side chain. As a result, across the pH range 4-6, only one epimer predominated sufficiently as a zwitterion to reach the critical molar fraction allowing gelation. By contrast, the differing pKa values and higher dipole moment of the other epimer favored crystallization. The four stereoisomers were further tested for gold nanoparticle (Au NP) formation, with the supramolecular hydrogel being key to control and stabilize Au NPs, yielding a nanocomposite that catalyzed the photodegradation of a dye. Importantly, the Au NP formation occurred without the use of reductants other than the peptide, and the redox chemistry was investigated by LC-MS and NMR. This study provides important insights for the rational design of simple peptides as minimalistic and green building blocks for functional nanocomposites
Advanced Cutaneous Squamous Cell Carcinoma: Italian Multicentric Retrospective Analysis of Patient Profiles and Therapeutic Approaches
Background: Advanced cutaneous squamous cell carcinoma (aCSCC) represents an area of unmet clinical need, with no standardized treatments until the recent approval of immune checkpoint inhibitors (ICIs). Objectives: The aim of the study was to describe clinical characteristics and therapeutic strategies of a real-life Italian cohort of aCSCC patients managed at the beginning of cemiplimab approval as compassionate use in Italy. Methods: A multicenter retrospective study was performed by 10 Italian centers in the period January 1, 2018-May 31, 2020. Patients aged >= 18 years and diagnosed with aCSCC (locally aCSCC and metastatic CSCC) were eligible for the study. Analysis of patients' characteristics and treatment strategies was performed. Results: 239 patients were initially recruited in the study: 19 patients were excluded due to incomplete data collection, yielding a final cohort of 220 patients, of which 191 and 220 were included for patients' clinical characteristics and therapeutic intervention analysis, respectively. Median age at the time of diagnosis was 81 years (range: 72-86); nodal metastases were detected in 64/220 (29%) patients, and distant metastatic spread was reported in 33/220 (15%) patients. Most of our patients referred chronic occupational and/or recreational sun exposure, experienced >= 1 sunburn during their lifetime, never wore hats or used photoprotective filters, and presented with signs of cumulative sun damage (solar lentigines and/or actinic keratosis). Majority of our cohort received at least one intervention directed to the primary tumor (n = 212, 96.3%); surgery and radiotherapy were the most common therapeutic choices. Immunotherapy was administered to a small number of patients as compassionate use, especially in the metastatic setting. Conclusions: Our study outlines the complex and heterogeneous clinical and therapeutic landscape of aCSCC patients at the beginning of ICI era, highlighting the need of a standardized care for this fragile and high-need patient population
Human Infection with Highly Pathogenic A(H7N7) Avian Influenza Virus, Italy, 2013
During an influenza A(H7N7) virus outbreak among poultry in Italy during August–September 2013, infection with a highly pathogenic A(H7N7) avian influenza virus was diagnosed for 3 poultry workers with conjunctivitis. Genetic analyses revealed that the viruses from the humans were closely related to those from chickens on affected farms
E-cigarettes induce toxicological effects that can raise the cancer risk
Electronic cigarettes (e-cigs) are devices designed to deliver nicotine in a vaping solution rather than smoke and without tobacco combustion. Perceived as a safer alternative to conventional cigarettes, e-cigs are aggressively marketed as lifestyle-choice consumables, thanks to few restrictions and a lack of regulatory guidelines. E-cigs have also gained popularity among never-smokers and teenagers, becoming an emergent public health issue. Despite the burgeoning worldwide consumption of e-cigs, their safety remains largely unproven and it is unknown whether these devices cause in vivo toxicological effects that could contribute to cancer. Here we demonstrate the co-mutagenic and cancer-initiating effects of e-cig vapour in a rat lung model. We found that e-cigs have a powerful booster effect on phase-I carcinogen-bioactivating enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), and increase oxygen free radical production and DNA oxidation to 8-hydroxy-2'-deoxyguanosine. Furthermore, we found that e-cigs damage DNA not only at chromosomal level in peripheral blood, such as strand breaks in leucocytes and micronuclei formation in reticulocytes, but also at gene level such as point mutations in urine. Our results demonstrate that exposure to e-cigs could endanger human health, particularly among younger more vulnerable consumers
E-cigarettes induce toxicological effects that can raise the cancer risk
Electronic cigarettes (e-cigs) are devices designed to deliver nicotine in a vaping solution rather than smoke and without tobacco combustion. Perceived as a safer alternative to conventional cigarettes, e-cigs are aggressively marketed as lifestyle-choice consumables, thanks to few restrictions and a lack of regulatory guidelines. E-cigs have also gained popularity among never-smokers and teenagers, becoming an emergent public health issue. Despite the burgeoning worldwide consumption of e-cigs, their safety remains largely unproven and it is unknown whether these devices cause in vivo toxicological effects that could contribute to cancer. Here we demonstrate the co-mutagenic and cancer-initiating effects of e-cig vapour in a rat lung model. We found that e-cigs have a powerful booster effect on phase-I carcinogen-bioactivating enzymes, including activators of polycyclic aromatic hydrocarbons (PAHs), and increase oxygen free radical production and DNA oxidation to 8-hydroxy-2′-deoxyguanosine. Furthermore, we found that e-cigs damage DNA not only at chromosomal level in peripheral blood, such as strand breaks in leucocytes and micronuclei formation in reticulocytes, but also at gene level such as point mutations in urine. Our results demonstrate that exposure to e-cigs could endanger human health, particularly among younger more vulnerable consumers