58 research outputs found
Spin connection as Lorentz gauge field: propagating torsion
We propose a modified gravitational action containing besides the
Einstein-Cartan term some quadratic contributions resembling the Yang-Mills
lagrangian for the Lorentz spin connections. We outline how a propagating
torsion arises and we solve explicitly the linearised equations of motion on a
Minkowski background. We identify among torsion components six degrees of
freedom: one is carried by a pseudo-scalar particle, five by a tachyon field.
By adding spinor fields and neglecting backreaction on the geometry, we point
out how only the pseudo-scalar particle couples directly with fermions, but the
resulting coupling constant is suppressed by the ratio between fermion and
Planck masses. Including backreaction, we demonstrate how the tachyon field
provides causality violation in the matter sector, via an interaction mediated
by gravitational waves.Comment: 7 pages, no figures, new section adde
METODOLOGIA DI APPROCCIO INTEGRATO SOSTENIBILITA’ – RESILIENZA NELLA RIABILITAZIONE DELLE INFRASTRUTTURE VIARIE DOPO EVENTI ESTREMI
Sustainability and resilience are relevant concepts in design and management of transport infrastructures. Sustainability refers to concept of development that meets the needs of the present without compromising the ability of future generations to meet their ones. Resilience is linked to the occurrence of extreme events during the life cycle of infrastructures and it is a measure of the ability of recovery the previous functionality. Traditionally, the two concepts are applied separately even if they present a significant number of similar characteristics. The better solutions in transport infrastructures design, maintenance and rehabilitation should lead to an improvement of both qualities. This paper presents an integrated approach sustainability-resilience as a useful tool in the decision-making process where different alternatives of rehabilitation after an extreme event are considered. Sustainability and resilience are estimated based on LCCA. The integrated perspective allows addressing an appropriate amount of technical, economic and environmental issues and is an useful tool for the identification of the most efficient solution
Biodiversity, Perceived Restorativeness, and Benefits of Nature: A Study on the Psychological Processes and Outcomes of On-Site Experiences in Urban and Peri-Urban Green Areas in Italy
Cancer astrocytes have a more conserved molecular status in long recurrence free survival (RFS) IDH1 wild-type glioblastoma patients: New emerging cancer players
Glioblastoma is a devastating disease that despite all the information gathered so far, its optimal management remains elusive due to the absence of validated targets from clinical studies. A better clarification of the molecular mechanisms is needed. In this study, having access to IDH1 wild-type glioblastoma of patients with exceptionally long recurrence free survival (RFS), we decided to compare their mutational and gene expression profile to groups of IDH1 wild-type glioblastoma of patients with shorter RFS, by using NGS technology. The exome analysis revealed that Long-RFS tumors have a lower mutational rate compared to the other groups. A total of 158 genes were found differentially expressed among the groups, 112 of which distinguished the two RFS extreme groups. Overall, the exome data suggests that shorter RFS tumors could be, chronologically, in a more advanced state in the muli-step tumor process of sequential accumulation of mutations. New players in this kind of cancer emerge from the analysis, confirmed at the RNA/DNA level, identifying, therefore, possible oncodrivers or tumor suppressor genes
Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries
Abstract
Background
Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres.
Methods
This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries.
Results
In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia.
Conclusion
This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries
Improved performance in flexible organic solar cells by using copolymeric phase-separation modulators
One of the main problems related to the low performance of the organic solar cells (OSCs), concerns the low mobility of the materials constituting the heterojunction. Indeed, the poor charge transport in the active layer is the principal cause of a competition between separation and recombination of the photogenerated carriers. In this regard, a major obstacle to enhance OSCs efficiency is developing strategies to optimize the exciton dissociation and, consequently, the charge collection at the electrodes. Donor and acceptor systems must be well mixed on the length scale of 5 – 20 nm (exciton diffusion length) to meet the criteria for efficient exciton dissociation. In addition, the network structure should involve continuous donor-acceptor pathways for efficient carrier transport. The most common practice to achieve this goal is by thermal or solvent annealing of active layer.[1] However, this approach often leads to an unwanted phase segregation with formation of large domains where only a small fraction of excitons could diffuse to the donor-acceptor interface.[2] In this work, we show how this challenge is achievable by incorporating phase-separation modulators into bulk heterojunction (BHJ). In particular, three copolymers based on polythiophene and C60 units have been designed, easily synthesized, characterized, and employed as additive in P3HT:PCBM devices. The effect of the thienyl spacer length between C60 monomers on optoelectronic properties, morphology, and structure of heterojunction has been examined using several techniques (NMR, FTIR, XPS, XRD and AFM). We observed that small quantities of these systems can play a critical role in tuning the device morphology by improving the phase separation in thin film heterojunction.[3] In particular, these copolymers act as phase separation modulators by controlling the growth of donor/acceptor domains in the heterojunction, during the thermal annealing process. Indeed, by employing copolymers containing oligothiophenic chains with size of about 8 nm, a large number of domains with a size comparable to the length scale of exciton diffusion are generated, resulting in the highest power conversion efficiency (PCE) (4.46 %) and short current density (JSC) (16.15 mA cm-2) values reported so far for P3HT:PCBM solar cells on plastic substrates. Moreover, the results obtained in preliminary investigations on the other devices containing different fullerene acceptors seem to show the effectiveness and the generality of our approach. Finally, bending tests showed that OSCs with copolymers maintain higher level of performance than reference devices, thus giving new perspectives to applications of flexible photovoltaics
Tossicodipendenti autori di reato e matrici familiari: l'utilizzo dell'Intervista Clinica Generazionale nel contesto carcerario
La ricerca sulle relazioni familiari privilegia l'utilizzo di scale di misurazione focalizzate su costrutti quali il coping familiare, il senso di coerenza, il perdono, l'efficacia familiare e finalizzate alla generalizzazione dei risultati. Meno frequente è l'utilizzo di strumenti di assessment terapeutico che pongano al centro dell'indagine clinica lo scambio generazionale tra i membri familiari. A questo proposito, l'Intervista Clinica Generazionale (ICG) è uno strumento dialogico ed intersoggettivo che consente di cogliere le qualità delle matrici familiari su tre assi: (1) rapporto con le origini; (2) relazione di coppia; (3) passaggio (relazione con il figlio).Il presente contributo si propone di presentare i risultati dell'applicazione dell'ICG su un campione di 25 detenuti tossicodipendenti. Le interviste sono state trascritte e sottoposte ad analisi testuale utilizzando il software T-LAB. Due sono gli obiettivi di ricerca: (1) valutare le caratteristiche dell'ICG in quanto strumento di assessment terapeutico; (2) studiare la relazione tra tossicomania e reato all'interno di una prospettiva relazionale-simbolica, che si emancipa dal determinismo causale avendo come fine la formulazione di ipotesi di senso. L'utilizzo dell'ICG in ambito carcerario e con detenuti tossicodipendenti ha messo in evidenza la flessibilità dello strumento nella sua applicazione in contesti particolari e la sua sensibilità nel rilevare le qualità del "corpo familiare", consentendo di mettere in rapporto la tossicomania e il reato da una prospettiva transgenerazionale. Da questo punto di vista è emerso quanto l'abuso di sostanze (prevalentemente cocaina) nella sua articolazione con un certo tipo di reati (generalmente spaccio o rapine) costituisca per il soggetto una difesa di tipo maniacale rispetto a vissuti di vuoto e depressione legati a storie familiari segnate da lutti precoci (con particolare riferimento alla figura paterna)
Colorectal Liver Metastases: A Literature Review of Viable Surgical Options with a Special Focus on Microwave Liver Thermal Ablation and Mini-Invasive Approach
Colorectal cancer (CRC) is the third most common tumor worldwide and it is characterized in 20–30% of cases by liver involvement, which strongly affects the long-term patient outcome. There are many available therapies for liver colorectal metastases (CRLMs); the current standard of care is represented by liver resection, and when feasible, associated with systemic chemotherapy. Microwave thermal ablation (MWA) is a viable option in unresectable patients or to achieve treatment with a parenchymal spearing approach. A literature review was performed for studies published between January 2000 and July 2022 through a database search using PUBMED/Medline and the Cochrane Collaboration Library with the following MeSH search terms and keywords: microwave, ablation, liver metastases, colorectal neoplasm, and colon liver rectal metastases. The recurrence rate and overall patients’ survival were evaluated, showing that laparoscopic MWA is safe and effective to treat CRLMs when resection is not feasible, or a major hepatectomy in fragile patients is necessary. Considering the low morbidity of this procedure, it is a viable option to treat patients with recurrent diseases in the era of effective chemotherapy and multimodal treatments
Botanical gardens as restorative environments: a study on the relationships between on-site experience and well-being
The literature on restorative environments has analysed the positive effects of people\u2019s transactions with different natural (wild areas, urban parks, etc.) and built settings (museums, monasteries, historical towns, etc.). To date, little attention has been paid to the analysis of the restorative potential of botanical gardens, which are characterised by a high level of biodiversity and human-made elements at the same time. Recent findings support the idea that biodiversity can play a major role in users\u2019 evaluations of green areas (Chen, Adimo, & Bao, 2009; Lindemann-Matthies & Bose, 2007) and may increase the psychological benefits associated with experience in nature (Fuller, Irvine, Devine- Wright, Warren, & Gaston, 2007). In addition, little is known about the process leading to restoration, as studies have mostly addressed the analysis of positive outcomes of restorative experiences. Botanical gardens with distinct physical properties were identified in four Italian cities, namely Padua, Florence, Rome, and Bari, and considered for the study. We administered a questionnaire focusing on people\u2019s experience in the botanical garden (length and frequency of visits, activities performed, perceived restorative properties and restorativeness, emotional response, perceived well-being) to an opportunistic sample (N = 127) contacted at the different locations. ANOVAs were conducted to analyse the relationships between the physical properties of the four botanical gardens and people\u2019s on-site experience, in terms of perceived restorative properties, emotional response, perceived well-being. In addition, we analysed the effect of group characteristics (gender, age, working activity) and of activities performed on users\u2019 experience in the botanical garden. A multiple regression analysis predicting perceived well-being was then carried out to test a model including several sets of variables: structural (e.g. distance from home, working activity, etc.), experiential (length and frequency of visits, activities performed), and psychological (perceived restorative properties, emotional response) ones. Results showed that the physical properties of botanical gardens affect the perception of the restorative properties and the emotional response toward the environment. Also activities performed play a role in shaping the experience of users: the more users spend their time in the botanical garden, the higher is the perceived level of the restorative properties and the better is the emotional response. Finally, multiple regression analysis showed that well-being experienced in botanical gardens is predicted by variables from the different sets included in the model, with perceived restorativeness and emotional response playing a key role. In particular, our analysis outline a mediation role of perceived restorativeness and emotional response in the relationship between experiential variables and perceived well-being. Theoretical implications for the study of restorative environments, and suggestions for the management of botanical gardens are discussed
Synthesis, Stereochemistry, and Solution Dynamics of Heterobimetallic Complexes with Metals Connected by Dithioxamides in κ-S,S‘ κ-N,N‘ Binucleation Mode. The Molecular Structure of [2-(Diphenylphosphino)pyridine-Pt-Cl-( μ
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