Effects of organic additives on calcium hydroxide crystallisation during lime slaking

Organic compounds, often used in cement systems as admixtures, may affect the crystallisation and carbonation kinetics of Ca(OH)2, an important phase of hydrated cement. Here, we investigated changes in Ca(OH)2 morphology in the presence of 3 organic compounds, commonly encountered in cement and lime-based materials: sucrose, pectin and calcium lignosulfonate. The additives were introduced either before or after lime slaking to determine the influence of temperature. Ca(OH)2 crystals and supernatant solutions were characterised at time of slaking and after 6 months of ageing using scanning electron microscopy, X-ray diffraction and optical emission spectroscopy. Our results indicate that the morphology of Ca(OH)2 crystals is modified by the characteristics of the organic molecules which promote formation of Ca(OH)2 with habits that can result in faster carbonation, an effect that is detrimental to cement used in reinforced concrete. These effects are enhanced when the additives are introduced before slaking, likely as a result of thermal degradation

Differential Variance Analysis: A direct method to quantify and visualize dynamic heterogeneities

Many amorphous materials show spatially heterogenous dynamics, as different regions of the same system relax at different rates. Such a signature, known as Dynamic Heterogeneity, has been crucial to understand the nature of the jamming transition in simple model systems and is currently considered very promising to characterize more complex fluids of industrial and biological relevance. Unfortunately, measurements of dynamic heterogeneities typically require sophisticated experimental set-ups and are performed by few specialized groups. It is now possible to quantitatively characterize the relaxation process and the emergence of dynamic heterogeneities using a straightforward method, here validated on video microscopy data of hard-sphere colloidal glasses. We call this method Differential Variance Analysis (DVA), since it focuses on the variance of the differential frames, obtained subtracting images at different time-lags. Moreover, direct visualization of dynamic heterogeneities naturally appears in the differential frames, when the time-lag is set to the one corresponding to the maximum dynamic susceptibility. This approach opens the way to effectively characterize and tailor a wide variety of soft materials, from complex formulated products to biological tissues

COVID-19 Incidence and Vaccine Effectiveness in University Staff, 1 March 2020–2 April 2022

Background: University workers undergo intense social interactions due to the frequent contact with students and colleagues and lectures in crowdy conditions. The aim of our study was to assess the incidence of COVID-19 infection and vaccine effectiveness in a cohort of workers of the University of Trieste from 1 March 2020 (start of the pandemic) through 2 April 2022. Methods: The University of Trieste implemented a number of public health policies to contain the spread of SARS-CoV-2 on the campus, including prompt contact tracing, the enhanced ventilation of all premises, fomites disinfection and the mandatory use of face masks indoors. In compliance with the surveillance protocol of the local public health department, university personnel were tested for SARS-CoV-2 by polymerase chain reaction (PCR) on a nasopharyngeal swab on demand, in the event of symptoms consistent with COVID-19 or for contact tracing, following close contact with a confirmed COVID-19 case. The incidence rates of SARS-CoV-2 infections were estimated as the number of cases by the number of person-days (p-d) at risk. The multivariable Cox proportional hazard regression model was employed to investigate the risk of primary COVID-19 infection, adjusting for a number of potential confounders and expressing the risk as the adjusted hazard ratio (aHR) with a 95% confidence interval (95% CI). Results: The incidence of SARS-CoV-2 infection among the university staff was lower than that of healthcare workers (HCWs) of the same area. Compared to unvaccinated colleagues (6.55 × 10,000 p-d), the raw incidence of SARS-CoV-2 infection was higher among university workers immunized with one (7.22 × 10,000 p-d) or two (7.48 × 10,000 p-d) doses of the COVID-19 vaccine, decreasing in those receiving the booster (1.98 × 1000 p-d). The risk of infection increased only in postgraduate medical trainees (aHR = 2.16; 95% CI: 1.04; 4.48), though this was limited to the Omicron transmission period. After the implementation of the national vaccination campaign against COVID-19, workers immunized with the booster were less likely than unvaccinated workers to be infected by SARS-CoV-2 both before (aHR = 0.10; 95% CI: 0.06; 0.16) and after (aHR = 0.37; 95% CI: 0.27; 0.52) the Omicron transmission period. The vaccine effectiveness of the booster was 90% (=(1−0.10) × 100) before versus 63% (=(1−0.37) × 100) during the Omicron wave, without a significant difference between homologous (three doses of m-RNA vaccines) and heterologous (first two doses of Vaxzevria followed by a third dose of m-RNA vaccine) immunization. Conclusions: The incidence of SARS-CoV-2 infection in the university staff was lower than that of HCWs of ASUGI, likely because the testing-on-demand schedule inevitably missed asymptomatic infections. Therefore, the observed significantly protective effect of the booster dose in university personnel referred to symptomatic SARS-CoV-2 infections. The infection prevention and control policies implemented by the University of Trieste managed to equalize the biological risk between the administrative and teaching staff

Febrile and gynaecological infections in pregnancy increase the risk of childhood respiratory disorders in the offspring

Emerging evidence suggests that foetal and early life environmental factors are critical for determining the susceptibility to allergic and respiratory diseases. In the present study, we investigated whether maternal febrile infections (FI) or gynaecological infections (GI) during pregnancy are associated with allergic respiratory diseases in the offspring, and whether specific pregnancy trimesters are involved.We enrolled 4,577 children, aged 3-14yr. Their parents filled in a standardized questionnaire about children’s respiratory health and the events occurred during pregnancy and at birth. We evaluated the incidence of wheezing, asthma and rhinitis, and the occurrence of five respiratory symptoms in the last 12 months.Children born to mothers who reported FI and GI had more respiratory symptoms in the last 12 months (IRR:1.40, 95%CI:1.12-1.74 and IRR:1.60, 95%CI:1.24-2.06, respectively). This association was stronger when FI occurred in the 1st trimester of pregnancy (IRR:2.12, 95%CI:1.37-3.28).The incidence of asthma was significantly higher in the children whose mothers reported FI or GI in the 1st trimester of pregnancy (HR:2.61, 95%CI:1.01-6.76 and HR:3.50, 95%CI:1.24-9.91, respectively). GI in the 3rd trimester were associated with higher risk of wheezing (HR:1.55, 95%CI:1.11-2.17) and rhinitis (HR:1.82; 95%CI:1.02-3.26).FI and GI might increase the risk of developing respiratory symptoms and diseases, especially when occurring in specific trimesters of pregnancy. These findings suggest that FI and GI might interfere with foetal programming of respiratory and immune system through different mechanisms

Febrile and gynecological infections during pregnancy are associated with a greater risk of childhood eczema

Background:Mounting evidence suggests that fetal exposures may exert long-termeffects on the function of the skin and of the immune system. This study aimed atassessing whether maternal complications during pregnancy are associated with anincreased risk of eczema during childhood.Methods:The associations between hypertension/preeclampsia, febrile infections, orgynecological infections during pregnancy and the occurrence of childhood eczema werestudied in a population (n=3907) of children, aged 3–14 yrs, living in Italy. Theirparents filled in a standardized questionnaire about the presence of children’s eczemaand the events that occurred during pregnancy, birth, and the first year of the child’s life.Results:7.7%, 3.8%, and 6.1% of the pregnancies were complicated by hypertension/preeclampsia, febrile infections, and gynecological infections, respectively. The preva-lence of eczema was significantly higher in children born to mothers who had experiencedfebrile (35.5% vs. 22.0%; p<0.001) or gynecological infections (35.3% vs. 21.6%;p<0.001) compared with those born to mothers who had not suffered from that specificpregnancy complication, while hypertension/preeclampsia was not significantly associ-ated with childhood eczema. After adjusting for potential confounders, the risk ofeczema was significantly higher in children born to mothers who reported febrileinfections during the 1st trimester (OR: 2.32; 95%CI: 1.11–4.82) and gynecologicalinfections during the 3rd trimester of pregnancy (OR: 2.73; 95%CI:1.73–4.31).Conclusions:Fetal exposure to febrile and gynecological infections might enhance therisk of eczema in the offspring, especially when occurring in specific trimesters ofpregnancy. These findings suggest that febrile and gynecological infections mightinterfere with fetal and perinatal programming of the immune function and skinthrough different mechanisms

Carbonation of Hydrous Materials at the Molecular Level: A Time of Flight-Secondary Ion Mass Spectrometry, Raman and Density Functional Theory Study

Carbonation of hydrous minerals such as calcium hydroxide (Ca(OH)2) is an important process in environmental and industrial applications for the construction industry, geological disposal repositories for nuclear waste, and green technologies for carbon capture. Although the role of ions during the carbonation mechanism of Ca(OH)2 is still unclear, we identified the exchange of ions during the dissolution and precipitation process, by determining the change in isotopic composition of carbonation products using time-of-flight-secondary ion mass spectrometry. Our samples of pure Ca(18OH)2 carbonated in air were characterized using scanning electron microscopy and Raman spectroscopy, aided by density functional theory calculations. Our results show that the carbonation process at high pH is a two-stage mechanism. The first stage occurs in a short time after Ca(18OH)2 is exposed to air and involved the dissolution of surface Ca ions and hydroxyl 18OH groups, which reacts directly with dissolved CO2, leading to 1/3 of 18O in the oxygen content of carbonate phases. The second stage occurs within 24 h of exposure allowing a rebalance of the oxygen isotopic composition of the carbonate phases with a higher content of 16O

A compact and automated ex vivo vessel culture system for the pulsatile pressure conditioning of human saphenous veins

Saphenous vein (SV) graft disease represents an unresolved problem in coronary artery bypass grafting (CABG). After CABG, a progressive remodelling of the SV wall occurs, possibly leading to occlusion of the lumen, a process termed 'intima hyperplasia' (IH). The investigation of cellular and molecular aspects of IH progression is a primary end-point toward the generation of occlusion-free vessels that may be used as 'life-long' grafts. While animal transplantation models have clarified some of the remodelling factors, the pathology of human SV is far from being understood. This is also due to the lack of devices able to reproduce the altered mechanical load encountered by the SV after CABG. This article describes the design of a novel ex vivo vein culture system (EVCS) capable of replicating the altered pressure pattern experienced by SV after CABG, and reports the results of a preliminary biomechanical conditioning experimental campaign on SV segments. The EVCS applied a CAGB-like pressure (80-120\u2009mmHg) or a venous-like perfusion (3\u2009ml/min, 5\u2009mmHg) conditioning to the SVs, keeping the segments viable in a sterile environment during 7\u2009day culture experiments. After CABG-like pressure conditioning, SVs exhibited a decay of the wall thickness, an enlargement of the luminal perimeter, a rearrangement of the muscle fibres and partial denudation of the endothelium. Considering these preliminary results, the EVCS is a suitable system to study the mechanical attributes of SV graft disease, and its use, combined with a well-designed biological protocol, may be of help in elucidating the cellular and molecular mechanisms involved in SV graft disease

Dynamic markers based on blood perfusion fluctuations for selecting skin melanocytic lesions for biopsy

Skin malignant melanoma is a highly angiogenic cancer, necessitating early diagnosis for positive prognosis. The current diagnostic standard of biopsy and histological examination inevitably leads to many unnecessary invasive excisions. Here, we propose a non-invasive method of identification of melanoma based on blood flow dynamics. We consider a wide frequency range from 0.005 – 2 Hz associated with both local vascular regulation and effects of cardiac pulsation. Combining uniquely the power of oscillations associated with individual physiological processes we obtain a marker which distinguishes between melanoma and atypical nevi with sensitivity of 100% and specificity of 90.9%. The method reveals valuable functional information about the melanoma microenvironment. It also provides the means for simple, accurate, in vivo distinction between malignant melanoma and atypical nevi, and may lead to a substantial reduction in the number of biopsies currently undertaken

Foetal exposure to maternal stressful events increases the risk of having asthma and atopic diseases in childhood

Background:The natural history of asthma and atopic diseases beginsin utero.Studies investigating the influence of foetal exposure to maternal stressful life eventsduring pregnancy (SLEP) on asthma and atopic diseases are lacking.Aim:To test whether the children of mothers who had experienced SLEP are at anincreased risk for asthma, atopic eczema and allergic rhinitis.Methods:The association between maternal SLEP (at least one among: divorce,mourning or loss of the job) and the occurrence of asthma and atopic diseases inchildhood was studied in a population (n = 3854) of children, aged 3–14 yrs, livingin Northern Italy. The parents filled in a standardized questionnaire about the chil-dren’s health and the events occurred to their mothers during pregnancy.Results:Three hundred and thirty-three (9%) of the mothers experienced SLEP.Their children had a statistically significantly higher lifetime prevalence of wheezing(31.6% vs. 23.1%), asthma (8.9% vs. 5.6%), allergic rhinitis (10.9% vs. 7.3%) andatopic eczema (29.7% vs. 21.1%) than those of mothers without SLEP. Afteradjusting for potential confounders, the foetal exposure to SLEP was positivelyassociated with wheezing (OR: 1.41, 95% CI: 1.03–1.94), asthma (OR: 1.71, 95%CI: 1.02–2.89), allergic rhinitis (OR: 1.75, 95% CI: 1.08–2.84) and atopic eczema(OR: 1.53, 95% CI: 1.11–2.10).Conclusion:The children of mothers who had experienced SLEP were at a moder-ately increased risk of having wheezing, asthma, eczema and allergic rhinitis duringtheir childhood. Maternal stress during pregnancy might enhance the expression ofasthma and atopic phenotypes in children.Pediatric Allergy and Immunology724Pediatric Allergy and Immunology23(2012) 724–729ª2012 John Wiley & Sons A/S. Published by Blackwell Publishing Lt