486 research outputs found
Production and Recovery of Astaxanthin from the Microalga Haematococcus pluvialis
Attualmente si sta diffondendo un grande interesse per l’uso nutraceutico e cosmetico dell'astaxantina naturale derivante dalla microalga Haematococcus pluvialis. L'astaxantina è un cheto-carotenoide secondario che tende ad accumularsi quando H. pluvialis è soggetta a condizioni di stress ed è un potente antiossidante. La presente tesi riguarda la produzione ed estrazione di astaxantina mediante metodi innovativi e sostenibili. L'acido ascorbico è stato il miglior fattore di stress che, in aggiunta ad una forte radiazione solare e carenza di nutrienti, ha favorito l'accumulo di astaxantina. Olio di mandorle e NaDES idrofobici a base di terpeni sono stati selezionati come candidati per ottenere formulati arricchiti in astaxantina direttamente disponibili per il consumo umano o per l'industria cosmetica; tutti i solventi sono stati testati attraverso il test di milking per mantenere in vita la coltura cellulare. In termini di vitalità cellulare, il miglior NaDES è stato il mentolo: acido oleico, seguito da α-bisabololo, mentolo: acido laurico e timolo: acido oleico; tuttavia il tasso di recupero di astaxantina è stato molto basso. L’olio di mandorle invece ha consentito il raggiungimento di un buon compromesso tra tasso di vitalità e di recupero. Entrambi i solventi hanno consentito di ricoltivare la coltura algale dopo una prima estrazione con approccio milking, senza compromettere la transizione cellulare dalla fase di stress a quella vegetativa. Questo fenomeno rende il processo di estrazione sostenibile riducendo i costi energetici ed economici associati alla perdita di biomassa algale. Nella seconda parte della tesi sono stati studiati gli effetti dell'astaxantina naturale e sintetica sulle cellule cancerogene Hep G2. I risultati dei test hanno dimostrato che sia l'astaxantina naturale che quella sintetica sono potenti antiossidanti; tuttavia solo l’astaxantina sintetica sembra avere un effetto sul metabolismo lipidico e sulla respirazione mitocondriale
Characterisation and analysis of uncertainties in building heat transfer estimates from co-heating tests
In recent years, measurement protocols for the estimation of the total aggregate building heat transfer coefficient (HTC) have provided sufficient empirical evidence to indicate that buildings often do not perform as intended. However, little research has been carried out into the associated uncertainties. Within this context, this paper reviews sources of uncertainty associated with co-heating tests; characterises these uncertainties and their impact on HTC estimates; and devises a method for the calculation of HTC uncertainty. The method proposed was applied to 14 co-heating tests, showing estimated total uncertainty ranging between 2.2-21.1 Image 1 (or 4.6-26.7% of the measured value) with a mean of 10.1 Image 1 (or 8.7%). The natural variation of HTC and often-observed inaccuracy of design calculations (the ‘prediction gap’) suggest that more accurate measurements may be of little benefit. Additionally, results suggest that weather conditions, challenging building design and poor experimental technique can all significantly contribute to HTC uncertainty. However, when suitable buildings are tested by experienced technicians and under suitable weather conditions, HTC estimates from the co-heating protocol are likely to provide a useful tool to assess and understand real-world building fabric performance
Data-driven smart buildings: Narratives of drivers and barriers from real-world implementations
Progress in the digitalisation of building services has been slow. Data-driven insights combined with innovative business models have the potential to unlockvalue. Yet barriers associated with implementing smart building technologies in the real worldinclude an unclear value proposition, differing stakeholder perspectives, and limited evidence of the benefits and disbenefits. This paper reports ongoingwork within the International Energy Agency Annex 81, “Data-driven smart buildings, ”to understandthe current technology landscape and opportunities by implementingdata-driven building servicesin non-domestic buildings. Several case studies were collected fromaround the world, contributed by Annex81 participants. This paper discusses stakeholder narratives on the value proposition and lessons learnt from the case studies collected and gives practical suggestions to overcomedigitalisation barriers
Urinary Cytology: Potential Role in Canine Urinary Tract Infections
The diagnosis of urinary tract infections (UTIs) requires a concomitant evaluation of clinical signs and urine culture, which is of fundamental to start an appropriate antibiotic treatment. Several factors, such as subclinical bacteriuria or pre-analytical errors, may make the interpretation of urine culture difficult. The aim of the study was to evaluate the association between the finding of neutrophils and bacteria in unstained and stained canine urine sediment and the presence of clinical signs and positive urine culture. Urine samples from 35 dogs with clinical signs of UTI and 55 asymptomatic dogs with risk factors for UTI were prospectively collected by cystocentesis, divided into three aliquots, and submitted for: (1) physical and chemical Dipstick analysis and unstained urinary sediment (casts, crystals, bacteria, leucocytes, cells, parasites); (2) stained urinary sediment (extra/intracellular bacteria, degenerated and non-degenerated neutrophils); (3) qualitative and quantitative urine culture and antimicrobial sensitivity-test. The association between unstained and stained findings of urinary sediment and urine culture was tested. Sensibility, specificity, and positive/negative predictive values in diagnosing positive urine cultures of bacteria at unstained and stained evaluation were compared. Both wet-mount bacteriuria and the cytological presence of intracellular and extracellular bacteria, neutrophils, and degenerated neutrophils were successively associated with positive urine culture (p < 0.001). The presence of intracellular bacteria was the only independent predictor of positive urine culture. Total bacterial count did not differ significantly between symptomatic and asymptomatic dogs. Detection of extracellular and intracellular bacteriuria at stained urinary sediment significantly improved the sensibility of predicting positive urine culture. Cytologic evaluation of urinary sediment may be helpful in detecting signs of active inflammation, thus enhancing the clinical relevance of a positive urine culture
Retrofitting traditional buildings: a risk-management framework integrating energy and moisture
Traditional buildings constitute a large proportion of the building stock in many countries worldwide; around 40% of the UK’s housing stock was built before 1940 and was primarily made with solid masonry walls. Only 11% of UK solid-walled dwellings had insulation installed, suggesting the high potential of the low-carbon retrofit of traditional buildings. However, there is evidence of the occurrence of unintended consequences, often associated with excess moisture. A method is presented for moisture risk management that includes the development of a process and a framework. These tools are then integrated into a novel framework for the combined energy and moisture performance retrofit of traditional buildings. An example of the framework’s practical application is provided, with a focus on retrofit measures for solid-wall insulation. The proposed systematic approach demonstrates the interconnected nature of energy and moisture. It harmonises the principles needed to support organisations in the delivery of robust retrofit of traditional buildings through the integration of pre-retrofit building assessment and post-retrofit monitoring in the process. The risk-management process and framework presented can be valuable tools to support designers in providing robust and scalable retrofit measures and strategies. 'Practice relevance' An integrated energy and moisture risk-management process is presented to support designers in the retrofit of traditional buildings. This is accompanied by a framework that explains the steps required for moisture risk management at the various stages of the retrofit process. This systematic approach harmonises the principles needed to support organisations in delivering robust low-carbon retrofits and integrates pre- and post-retrofit building assessment in the process. While previous work has addressed energy and moisture management separately, this integrates the two aspects into a framework for risk management. An example illustrates the relevant modes and methods of assessment and monitoring in support of risk management. When combined with practical guidelines and training, the risk-management process and framework can be valuable tools to provide robust and scalable retrofit measures and strategies. The framework was developed within the context of the UK construction industry; it can be adapted to other contexts
3-D visualization of urban environmental quality indicators: using the city GML standard
In October 2005, a survey to several potential end-users (surveyors, architects, urban planners, environmental and energy specialists, among others) of the City of Geneva (Switzerland) howed a strong interest for the integration of the third dimension in the available GIS data of the City of Geneva, mainly by the integration of new layers of information, here referred to as 3-D urban indicators [1]. In order to extract this type of indicators, different geo-referenced data of excellent quality, such as 2-D cadastral data, aerial images, LiDAR (Light Detection And Ranging) data and a 3-D vector model were used. A main focus was given to the construction of innovative 3-D Urban Environmental Quality (UEQ) indicators, which are highlighted through the 3-D visualization displays proposed here. A simple example is the exploration of the solar potential of building facades and roofs. In this case, the purpose is to evaluate the potential of buildings for the installation of solar panels (photovoltaic and thermal).Peer Reviewe
How Can Scientific Literature Support Decision-Making in the Renovation of Historic Buildings?:An Evidence-Based Approach for Improving the Performance of Walls
Buildings of heritage significance due to their historical, architectural, or cultural value, here called historic buildings, constitute a large proportion of the building stock in many countries around the world. Improving the performance of such buildings is necessary to lower the carbon emissions of the stock, which generates around 40% of the overall emissions worldwide. In historic buildings, it is estimated that heat loss through external walls contributes significantly to the overall energy consumption, and is associated with poor thermal comfort and indoor air quality. Measures to improve the performance of walls of historic buildings require a balance between energy performance, indoor environmental quality, heritage significance, and technical compatibility. Appropriate wall measures are available, but the correct selection and implementation require an integrated process throughout assessment (planning), design, construction, and use. Despite the available knowledge, decision-makers often have limited access to robust information on tested retrofit measures, hindering the implementation of deep renovation. This paper provides an evidence-based approach on the steps required during assessment, design, and construction, and after retrofitting through a literature review. Moreover, it provides a review of possible measures for wall retrofit within the deep renovation of historic buildings, including their advantages and disadvantages and the required considerations based on context
Adherence to Herpes Zoster (Shingles) Catch-Up Campaign at the Romagna Local Health Authority (Italy), a Multi-Center Retrospective Observational Study
: Herpes Zoster (shingles) is an infection that occurs when varicella-zoster virus reactivates from the latent state. Incidence and severity of Herpes Zoster disease increase with age. Antiviral drugs are the elective treatment; however, prevention of disease reactivation through effective and safe vaccines is available in Italy out-of-pocket from age 65 onwards. The Romagna Local Health Authority (northern Italy) administered catch-up vaccinations in March-May 2022 for immunizations not performed during the COVID-19 pandemic. In this study, adherence rates to the catch-up campaign and recall activities adopted in two centers were investigated. The uptakes for only the catch-up vaccinations were 11.4% and 12.4%. Having suffered from Herpes Zoster or having family members who suffered from it would not seem to be drivers of increased uptake. Although sending text-messages to all involved patients was the main motivation for vaccine uptake (85.7-95.1%), word of mouth and web/news advertising also contributed to adoption in Center No. 2. In both centers, the need for greater synergy between public health departments and general practitioners to engage their patients emerged, as did the need for additional recall measures. Studying the main drivers of vaccine hesitancy, especially at the local level, can help in targeting campaigns and catch-up activities in order to achieve widespread acceptance
Cathepsin K-deficient osteocytes prevent lactation-induced bone loss and parathyroid hormone suppression
Lactation induces bone loss to provide sufficient calcium in the milk, a process that involves osteoclastic bone resorption but also osteocytes and perilacunar resorption. The exact mechanisms by which osteocytes contribute to bone loss remain elusive. Osteocytes express genes required in osteoclasts for bone resorption, including cathepsin K (Ctsk), and lactation elevates their expression. We show that Ctsk deletion in osteocytes prevented the increase in osteocyte lacunar area seen during lactation, as well as the effects of lactation to increase osteoclast numbers and decrease trabecular bone volume, cortical thickness, and mechanical properties. In addition, we show that Ctsk deletion in osteocytes increased bone parathyroid hormone-related peptide (PTHrP) and prevented the decrease in serum parathyroid hormone (PTH) induced by lactation, but amplified the increase in serum 1,25-dyhydroxyvitamin D [1,25(OH)(2)D]. The net result of these changes is to maintain serum and milk calcium levels in the normal range, ensuring normal offspring skeletal development. Our studies confirm the fundamental role of osteocytic perilacunar remodeling in physiological states of lactation and provide genetic evidence that osteocyte-derived Ctsk contributes not only to osteocyte perilacunar remodeling, but also to the regulation of PTH, PTHrP, 1,25(OH)(2)D, osteoclastogenesis, and bone loss in response to the high calcium demand associated with lactation
- …