130 research outputs found
Stereospecific ethylene-styrene block copolymerization with ansa-zirconocene-based catalyst
rac-[Methylene(3-tert-butyl-1-indenyl)(2)]ZrCl2 activated by MAC, employed as catalyst in the ethylene-styrene copolymerization, shows a peculiar behavior. Actually, it produces block copolymers, whereas the homogeneous catalytic systems known to copolymerize these monomers preferentially give rise to alternating sequences of ethylene and styrene. The polystyrene blocks are isotactic and show crystallinity, also when their average length is as short as 10 units. Some evidence suggests the primary styrene insertion into the metal-carbon bond of the growing chain: this unusual regiochemistry could account for the observed tendency to give homosequences
Assessing the (In)Stability of Urban Art Paints: From Real Case Studies to Laboratory Investigations of Degradation Processes and Preservation Possibilities
Urban art as a shared expression of street art between artists, citizenship and municipalities has always had an important role in the social life and appearance of modern cities. However, the durability of urban and street artworks is susceptible to the degradation processes that the employed commercial paint formulations undergo once outdoors. These are complex mixtures of compounds, differently sensitive to environmental agents according to their chemical nature. Starting from the colorimetric analysis of murals created in 2010, 2011 and 2018 in Reggio Emilia, Italy, documenting their degradation already after a few months, this study aimed at understanding the stability of the most unstable paints used by the artists in these artworks. A multi-analytical approach evaluated the commercial products under the chemical point of view, after natural and accelerated ageing. Additionally, two manufactured anti-UV varnishes were evaluated for their possible use as coatings. The results pinpointed the weaknesses of the selected paints and highlighted how the application of an anti-UV coating might slightly affect the visual aspect of the artwork, though ensuring a greater resistance to the outdoor conditions due to their minor chemical sensitivity to environmental agents
Diagnosis of anal human papillomavirus infection: polymerase chain reaction or cytology?
Summary Objectives To investigate the relationship between human immunodeficiency virus (HIV)-positive and HIV-negative patients engaging in promiscuous behaviors and anal human papillomavirus (HPV) infection diagnosed by polymerase chain reaction (PCR) and cytology. Methods Fifty-six HIV-positive patients and 49 HIV-negative patients who engaged in sexually promiscuous behavior were enrolled in the study. We performed cytological exams using the Pap smear and PCR for HPV-DNA detection, with identification of oncogenic strains. The 2001 Bethesda System terminology was used for the cytological exams. We also evaluated the immunologic status of the HIV-infected patients. Results PCR positivity for HPV-DNA was higher in the group of HIV-positive patients than in the group of HIV-negative patients with a statistically significant difference. In contrast we did not find any statistically significant difference by cytological exam. Oncogenic strains were equally distributed in the two groups. Conclusions Our results indicate the importance of the cytological exam for anal HPV screening in the population at high risk of sexually transmitted disease and that HPV-DNA PCR can be used only as adjunct test
Synergism between bisphenol a exposure and overweight/obesity in increasing the malignancy risk in a cohort of patients with thyroid nodules
BPA exposure conferred higher risk of thyroid cancer only in case of concomitant overweight/obesity, therefore suggesting a synergistic action between BPA and the excess of adipose tissue in promoting thyroid carcinogenesis
Self-perception about health and wellness effects on recreational five-a-side football athletes
In this study, we examine the health and well-being perceptions arising from some of the most commonly used physical activities to achieve physical well-being. In particular, we focus on the perceptive aspects specific to recreational football, trying to understand what can be the parameters that acquire a greater benefit on a physical level and what are the diseases that can be prevented by practicing this activity. Through some questions asked to a group of 15 boys, aged between 23 and 29, it was found that recreational football can achieve greater physical resistance (71.4%) and a decrease in body fat (57.1 %), and that we can prevent cardiovascular diseases (76.9%) and obesity (61.5%). Furthermore, the data collected showed that the analysed sample considers it more appropriate to do the one activity than another, depending on the physical well-being that one wants to achieve. For example, according to the interviewees, to increase lean mass it is better to perform strength training (66.7%). According to many other studies, therefore, this type of activity significantly improves both in terms of perceptions and real data, the general physical well-being of the person who practices it
Emergence of Exhausted B Cells in Asymptomatic HIV-1-Infected Patients Naïve for HAART is Related to Reduced Immune Surveillance
Alterations of B cell subpopulations have been described up to date as characterizing advanced stage of HIV-1 infection. However, whether such defects are relevant in subjects with a preserved number of CD4+ T cells (>350 cells/μL) is unclear. In a cross-sectional study, we investigated if signs of B cells exhaustion and impaired viral immune surveillance are present in a cohort of 43 asymptomatic HIV-1-infected patients with preserved CD4+ T cell counts (>350 cells/μL) and highly active antiretroviral therapy (HAART) untreated. A dramatic expansion of exhausted tissue-like memory B cells (CD10−CD21lowCD27−) was observed. B cells alteration was related to an increase in Torque teno virus (TTV) load, used as surrogate marker of immune function. Successfully HAART-treated patients showed normalization of B cell subpopulations frequency and TTV load. These results provide new insights on B cell in HIV-1 infection and show that development of B cell abnormalities precedes CD4+ T cell decline
ALLELE-SPECIFIC TRANSCRIPTIONAL ACTIVITY OF THE VARIABLE NUMBER OF TANDEM REPEATS OF THE INDUCIBLE NITRIC OXIDE SYNTHASE GENE IS ASSOCIATED WITH IDIOPATHIC ACHALASIA
Background: Polymorphisms of genes involved in the regulation of the immune response are risk factors for achalasia, but their contribution to disease pathogenesis is unknown. Nitric oxide is involved in both immune function and inhibitory neurotransmission.
Objective: to assess the association and the functional relevance of the CCTTT inducible Nitric Oxide Synthase (NOS2) gene promoter polymorphism in achalasia.
Methods: Genomic DNA was isolated from 181 achalasia patients and 220 controls. Genotyping of the (CCTTT)n repeats was performed by PCR and capillary electrophoresis, and data analyzed by considering the frequency of the different alleles. HT29 cells were transfected with iNOS luciferase promoter-reporter plasmids containing different (CCTTT)n.
Results: The alleles’ distribution ranged from 7 to 18, with a peak frequency at 12 repeats. Analysis of the allele frequencies revealed that individuals carrying 10 and 13 CCTTT repeats were respectively less and more frequent in achalasia (OR 0.5, 95% CI 0.3-0.5 and OR 1.6, 95% CI 1-2.4, all p<0.05). Long repeats were also significantly associated with an earlier onset of the disease (OR 1.69, 95% CI 1.13-2.53, p=0.01). Transfection experiments’ revealed a similar allele-specific iNOS transcriptional activity.
Conclusion: The functional polymorphism (CCTTT) of NOS2 promoter is associated with achalasia, likely by an allele-specific modulation of nitric oxide production
BCI devices and their capacity to express human will having legal value: A model of risk-based classification
One of the ultimate frontiers in biotechnology is Brain-computer-interface. BCI devices are currently developed for therapeutic purposes (e.g., as assistive tools) but also recreational ones. A BCI system detects brain activity, allowing a decoding of patterns of neural signals, then ‘translatable’ in commands a computer can understand and even carry out in the external reality. That’s why BCI is now becoming more used (or experimented), considering the advantages that could derive from it. Nevertheless, it also raises some questions from a legal perspective. This Paper focuses on BCI-based devices used for assistive and augmented communication of users, and wonders what legal regime should be accorded to the personal will expressed through those tools. Once the risks have been identified, the parameters and requirements a BCI device must meet, for the human will expressed through it having legal value, are outlined. The Paper proposes, in conclusion, a self-assessment strategy to operationalize BCI technologies applicable to the context of legal relations, implementing methods of risk evaluation and management. A risk- based classification model is also suggested
Heterogeneity and penetration of HIV-1 non-subtype B viruses in an Italian province: Public health implications
SUMMARYThis study assessed changes in prevalence and distribution of HIV-1 non-subtype B viruses in Italian and immigrant patients over two decades in a province in Italy. All HIV-positive patients who underwent genotypic resistance testing were selected. Prevalence of non-subtype B viruses in 3-year periods was calculated. All sequences of non-subtype B and those provided by REGA as unassigned were analysed for phylogenetic relationships. In total, 250/1563 (16%) individuals were infected with a non-subtype B virus. Prevalence increased over time, reaching a peak (31·5%) in 2004–2006. In Italian patients, the most frequent subtypes were B (92·5%) and F1 (4%). F1 subtype was also prevalent in patients from South America (13·6%); in patients of African origin, CRF02_AG (54·9%) and G (12·3%) were the most frequent. HIV-1 non-subtype B infections in Italians were mostly found in patients who acquired HIV sexually. A phylogenetic relationship between F subtypes in Italian and representative HIV-1 sequences from Brazil was found. C subtypes in Italians were phylogenetically related to subtypes circulating in Brazil. Inter-subtype recombinants were also found in the latest years. The HIV-1 epidemic in Brescia province evolved to the point where about 1/3 patients recently diagnosed harboured non-B HIV subtypes. The distribution of HIV-1 non-B subtypes in Italian patients resembled that in South American patients and phylogenetic relatedness between some Italian and South American HIV-1 strains was found. The possible epidemiological link between these two populations would have been missed by looking only at risk factors for HIV acquisition declared by patients. The evidence of inter-subtype recombinants points to significant genetic assortment. Overall our results support phylogenetic analysis as a tool for epidemiological investigation in order to guide targeted prevention strategies
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