136 research outputs found
Agricoltori come “custodi del territorio”: il caso della Valle del Serchio in Toscana
The article focuses on the project “Custody of the Territory”, an initiative promoted by a territorial authority of a mountainous area of the Tuscany region (Unione dei Comuni Media Valle del Serchio) which set an agreement with local farmers to improve the hydro-geological management of the district. This innovative flooding prevention strategy, based on farmers’ knowledge and capabilities, shows that an effective hydro-geological management of the territory in mountainous areas should involve not only changes in farmers’ practices, but also a more structural shift regarding their identity, motivations and attitudes. The article highlights the need of implementing integrated policy tools based not only on compensation but also on incentives, communication and learning opportunities, since farmers’ knowledge and joint learning (amongst farmers, institutions, technicians, academics) are very important issues for an effective provision of environmental services through agriculture.L’articolo descrive il progetto Custodia del Territorio, un’iniziativa promossa dall’Unione dei Comuni della Media Valle del Serchio (LU) che ha stipulato contratti di sorveglianza e manutenzione del reticolo idraulico con gli agricoltori locali all’interno della propria area di competenza. Questa strategia innovativa per la prevenzione idraulica, basata sul rafforzamento delle conoscenze e delle abilità degli agricoltori, evidenzia come un’effettiva gestione degli aspetti idraulici nelle aree montane dovrebbe includere non solo cambiamenti nelle pratiche degli agricoltori, ma anche un cambiamento più strutturale che riguarda le loro identità , motivazioni e attitudini. L’articolo sottolinea la necessità di favorire delle politiche integrate basate non solo sulla corresponsione di pagamenti, ma anche su incentivi, comunicazione e opportunità di apprendimento per gli attori locali. Si evidenzia, inoltre, la necessità di sviluppare forme di conoscenze condivise (tra agricoltori, istituzioni, tecnici e ricercatori) per rendere più efficace l’erogazione di servizi ambientali da parte dell’agricoltura
Correlation of Shear Bond Strength and Degree of Conversion in Conventional and Self-Adhesive Systems Used in Orthodontic Bonding Procedures
Abstract
(1) Background: Self-adhesive systems have been proposed for the orthodontic bonding with the intention to reduce the traditional three-component system. (2) Methods: The sample consisted of 32 extracted intact permanent premolars randomly divided into two groups (n = 16). In Group I the metal brackets were bonded with Transbond XT Primer and Transbond XT Paste. In Group II the metal brackets were bonded with GC Ortho connect. The resin was polymerized for 20 s from two directions (mesial and occlusal) using a Bluephase light-curing unit. The shear bond strength (SBS) was measured using a universal testing machine. Immediately after SBS testing, Raman microspectrometry was performed for each sample to calculate the degree of conversion (DC). (3) Results: There was no statistically significant difference in the SBS between the two groups. A significantly higher DC (p < 0.001) value was recorded in Group II, in which the brackets were bonded with GC. Very weak or no correlation (0.01) was recorded between SBS and DC in Group I and moderate positive correlation was recorded in Group II (0.33). (4) Conclusions: No difference was found in SBS between the conventional and two-step systems used in orthodontics. The two-step system demonstrated higher DC compared to the conventional system. There is a very weak or moderate correlation between DC and SBS
Molecular modeling of the interface of an egg yolk protein-based emulsion
Many food emulsions are stabilized by functional egg yolk biomolecules, which act as surfactants at the oil/water interface. Detailed experimental studies on egg yolk emulsifying properties have been largely hindered due to the difficulty in isolating individual chemical species. Therefore, this work presents a molecular model of an oil/water interfacial system where the emulsifier is one of the most surface-active proteins from the egg yolk low-density lipoproteins (LDL), the so-called Apovitellenin I. Dissipative particle dynamics (DPD) was here adopted in order to simulate large systems over long time scales, when compared with full-atom molecular dynamics (MD). Instead of a manual assignment of the DPD simulation parameters, a fully automated coarse-graining procedure was employed. The molecular interactions used in the DPD system were determined by means of a parameter calibration based on matching structural data from atomistic MD simulations. Despite the little availability of experimental data, the model was designed to test the most relevant physical properties of the protein investigated. Protein structural and dynamics properties obtained via MD and DPD were compared highlighting advantages and limits of each molecular technique. Promising results were achieved from DPD simulations of the oil/water interface. The proposed model was able to properly describe the protein surfactant behavior in terms of interfacial tension decrease at increasing protein surface concentration. Moreover, the adsorption time of a free protein molecule was estimated and, finally, an LDL-like particle adsorption mechanism was qualitatively reproduced
Multiscale simulation of a high-shear mixer for food emulsion production
Food emulsions, such as mayonnaise, are made of a continuous water phase, a dispersed phase with a high content of oil, and a surfactant (i.e. the egg yolk for mayonnaise) that stabilizes the oil drops. The droplet size distribution (DSD) is the most important property of the emulsion since the structure, stability, taste, and color of the final product depend on the DSD. The DSD in turn depends on the emulsion composition, the type of process, and the operating conditions in which the production process operates. The production of emulsions is based on mixing the ingredients and applying enough mechanical energy to the emulsion, to reach the desired DSD. In particular, for the food emulsion investigated in this work, i.e. the mayonnaise, a typical mixing process is composed of two steps (Figure 1). First, the ingredients (mainly egg yolk, vinegar, oil, water, salt) are mixed together in large stirred vessels at a moderate rotational speed. Then, this premixed emulsion is finally fluxed into a high-shear device, commonly a cone mill mixer, where the oil droplets undergo breakage until the final size distribution is reached. This last step is crucial to fine-tune the DSD, in order to determine the properties of the final product. A typical cone mill is constituted of a solid conical frustum rotor inside a slightly larger stator of the same shape, forming a small gap in which the emulsion flows and experiences high shear stresses, due to the high rotational speed of the rotor.
Within the multiscale framework, different time- and space- scales are investigated to describe the modeling approach for the macro-scale (cone mill) and the molecular scale (oil-water interface). Computational fluid dynamics (CFD) simulations are employed to properly describe the non-Newtonian dynamics of the emulsion, investigate the role of the pre- and post-mixing zones and clarify the importance of the type of flow, namely pure-shear versus elongational. In order to describe the evolution of the droplet size distribution, the Population Balance Modelling (PBM) is employed, in which coalescence and breakage of oil droplets are taken into account by appropriate kernels, which depend on local flow conditions.
During the emulsification process, the interfacial properties between dispersed and continuous phases have an essential role in the formation and stabilization of the oil droplets. Once the chemical composition of mayonnaise is determined, especially the biomolecules acting as surfactants, the interfacial tension between the two phases is directly computed with the help of atomistic techniques, such as Molecular Dynamics (MD) and Dissipative Particle Dynamics (DPD). This mesoscale approach also provides the surfactant adsorption kinetics and its molecular conformation at the interface, paving the way for a better understanding of the breakage and coalescence events of the oil droplets occurring in the production process. This information can be eventually transferred to the CFD-PBM simulations thus achieving a complete, general, and multi-scale model of the food emulsion production process.
This effort is carried out in the context of the VIMMP project (www.vimmp.eu), where the entire workflow will serve to devise a marketplace for generic multiscale and multiphysics simulations. The VIMMP project has received funding
from the European Union’s Horizon 2020 Research Innovation Programme under Grant Agreement n. 760907
Impact of cavity shave margins in patients with ductal carcinoma in situ undergoing conserving breast surgery
aim: the main challenge during breast-conserving surgery (BCS) is to obtain clear margins, especially in patients with ductal carcinoma in situ (DCIS) due to the absence of well-defined nodules. many surgical approaches have been used in an attempt to reduce the positive margin rate. the aim of this retrospective study is to compare the cavity shave margin technique with standard surgery and the intraoperative evaluation of surgical margins. methods: this is a single-center retrospective study analyzing margin status, need for re-excision, and surgical time in a cohort of 227 patients who underwent surgery from september 2016 to september 2022. results: In patients subjected to cavity shaving, we reported a significant reduction in positive margins of 17.1% versus 28.7% (p-value = 0.042). also, a difference in terms of surgical re-excision was reported as p-value = 0.039 (12.4% versus 23.8%, respectively, for the cavity shave and control group). In the multivariate analysis, intraoperative evaluation of the margins was a risk factor for margins re-excision (Wald = 4.315, p = 0.038, OR: 2.331 [95% CI: 1.049-5.180]). surgical time was lower in patients subjected to cavity shaves (p = 0.024), and the relative mean time was 68.4 min +/- 37.1 min in the cavity shave group versus 93.9 min +/- 40.6 min in the control group. conclusion: the cavity shave margin technique in conserving breast surgery results in a reduction in positive margin rate, surgical re-excision, and operative time
Breast Cancer and Pregnancy: Epidemiology, Phenotypes, Presentation during Pregnancy, and Therapeutic Approaches
Breast cancer (BC) represents the most frequent cancer worldwide, with almost 2.26 million new diagnoses recorded in 2020, and is the most common malignant neoplasia diagnosed during pregnancy. Pregnancy-related Breast Cancer (PrBC), indeed, is diagnosed in 1 in 2000–4000 pregnant women every year in Europe. PrBC is frequently characterized by unfavorable biological marks that, along with the late diagnosis, the limited imaging applicable, and the often-suboptimal treatments necessary to protect the fetus, could possibly lead to a worse prognosis in this population of patients. Babies born from mothers treated for cancer during pregnancy have been followed during a long-term follow-up and have showed cognitive and physical functions not different from the general population, but more studies are needed. Taking into consideration the complexity of the disease, a multidisciplinary approach is crucial to define the best therapeutical path
Trace Elements in Chromian Spinels from Four Siberian Kimberlites
We analysed the major, minor and trace elements chemistry of forty-two Cr-spinels from four Siberian kimberlites. They showed a wide range in Mg# (Mg/(Mg + Fe2+); 0.42–0.78) and Cr# (Cr/(Cr + Al); 0.32–0.92) and a common trend of increasing Cr# with decreasing Mg#. The major element classification schemes suggested that there were spinels deriving from a peridotitic source (Xen) and spinels crystallised from kimberlitic melts (Chr). Laser-Ablation Inductively Coupled Plasma Mass Spectrometry on both groups showed that the trace elements with the highest abundance were Mn (985–3390 ppm), Ni (531–3162 ppm), V (694–2510 ppm) and Zn (475–2230 ppm). Testing the effectiveness of trace elements in determining the source for Cr-spinels, we found out that Cr-spinels crystallised directly from a kimberlitic melt usually showed higher Mn, Ni, Sc and V concentrations with respect to those of peridotitic origin. In addition, using the available partitioning models, we found that the correlations between major elements and Ni, Co, Sc and Ga in the Xen group could be explained by subsolidus equilibration between spinel, olivine and clinopyroxene at 800–1000 °C, thus supporting a peridotitic source for this group. Finally, we calculated the composition of the possible melts in equilibrium with the Cr-spinels of the Chr group, using a selected set of partition coefficients. Calculated abundances of Cu, Ga and Zr were comparable to those of the kimberlite, while V was never close to the kimberlite composition. This simulation highlighted the need for new data on the trace elements partition coefficients between
kimberlitic melts and Cr-spinel
Th1 and Th17 pro-inflammatory profile characterizes iNKT cells in virologically suppressed HIV+ patients with low CD4/CD8 ratio
INTRODUCTION:: Scanty data exist on the phenotype and functionality of invariant natural killer T (iNKT) cells in HIV+ patients (pts). METHODS:: By flow cytometry, we studied iNKT cells from 54 HIV+ pts who started combined antiretroviral therapy (cART) and had undetectable viral load for >1 year. Twenty-five maintained a CD4/CD8 ratio <0.4, while 29 reached a ratio >1.1; 32 age- and sex-matched subjects were healthy controls (CTR). RESULTS:: Pts with low ratio had lower percentage of CD4+ iNKT cells compared to pts with high ratio, and higher CD8+ iNKT cell percentage; double negative (DN) iNKT cells were lower in HIV+ pts compared to CTR. Pts with low ratio had higher percentage of CD4+ and DN iNKT cells expressing CD38 and HLA-DR compared to pts with high ratio. CD4+ iNKT cells expressing PD-1 were higher in pts with CD4/CD8 ratio <0.4, while DN iNKT cells expressing PD-1 were lower compared to pts with ratio >1.1. Pts with low ratio had higher CD4+ iNKT cells producing IL-17, CD8+ iNKT cells producing IFN-γ, TNF-α or IFN-γ plus TNF-α, and DN iNKT cells producing IL-17 or IL-17 plus IFN-γ compared to CTR. Activated CD4+ (or CD8+) T cells correlated with activated CD4+ (or CD8+) iNKT cells, as well as the percentages of CD4+ (or CD8+) T cells expressing PD-1 was correlated to that of CD4+ (or CD8+) iNKT cells expressing PD-1. CONCLUSIONS:: Low CD4/CD8 ratio despite effective cART is associated with altered iNKT cell subsets, enhanced activation and prominent Th1/Th17 pro-inflammatory profile
The Combination of Immune Checkpoint Blockade with Tumor Vessel Normalization as a Promising Therapeutic Strategy for Breast Cancer: An Overview of Preclinical and Clinical Studies
Immune checkpoint inhibitors (ICIs) have a modest clinical activity when administered as monotherapy against breast cancer (BC), the most common malignancy in women. Novel combinatorial strategies are currently being investigated to overcome resistance to ICIs and promote antitumor immune responses in a greater proportion of BC patients. Recent studies have shown that the BC abnormal vasculature is associated with immune suppression in patients, and hampers both drug delivery and immune effector cell trafficking to tumor nests. Thus, strategies directed at normalizing (i.e., at remodeling and stabilizing) the immature, abnormal tumor vessels are receiving much attention. In particular, the combination of ICIs with tumor vessel normalizing agents is thought to hold great promise for the treatment of BC patients. Indeed, a compelling body of evidence indicates that the addition of low doses of antiangiogenic drugs to ICIs substantially improves antitumor immunity. In this review, we outline the impact that the reciprocal interactions occurring between tumor angiogenesis and immune cells have on the immune evasion and clinical progression of BC. In addition, we overview preclinical and clinical studies that are presently evaluating the therapeutic effectiveness of combining ICIs with antiangiogenic drugs in BC patients
Analysis of inflammasomes and antiviral sensing components reveals decreased expression of NLRX1 in HIV-positive patients assuming efficient antiretroviral therapy
Objective: Few studies have investigated the importance of different components of the inflammasome system and of innate mitochondrial sensing (IMS) pathways in HIV infection and its treatment. We analysed the expression of several components of the inflammasome and of the IMS in HIV-positive patients taking successful combination antiretroviral therapy (cART). Methods: We enrolled 20 HIV-positive patients under cART, who achieved viral suppression since at least 10 months and 20 age and sex-matched healthy donors. By RT-PCR, using peripheral blood mononuclear cells (PBMCs), we quantified the mRNA expression of 16 genes involved in inflammasome activation and regulation (AIM2, NAIP, PYCARD, CASP1, CASP5, NLRP6, NLRP1, NLRP3, TXNIP, BCL2, NLRC4, PANX1, P2RX7, IL-18, IL-1\u3b2, SUGT1) and eight genes involved in IMS (MFN2, MFN1, cGAS, RIG-I, MAVS, NLRX1, RAB32, STING). Results: Compared with controls, HIV-positive patients showed significantly lower mRNA levels of the mitochondrial protein NLRX1, which plays a key role in regulating apoptotic cell death; main PBMC subpopulations behave in a similar manner. No differences were observed in the expression of inflammasome components, which however showed complex correlations. Conclusion: The decreased level of NLRX1 in HIV infection could suggest that the virus is able to downregulate mechanisms linked to triggering of cell death in several immune cell types. The fact that HIV-positive patients did not show altered expression of inflammasome components, nor of most genes involved in IMS, suggests that the infection and/or the chronic immune activation does not influence the transcriptional machinery of innate mechanisms able to trigger inflammation at different levels
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