FT-NIR spectroscopy for the quality characterization of apricots (Prunus armeniaca L.)

Abstract: The nondestructive assessment of apricot fruit quality (Bora cultivar) was carried out by means of FT-NIR reflectance spectroscopy in the wavenumber range 12000 to 4000 cm⁻¹. Samples were harvested at four different ripening stages and scanned by a fiber optical probe immediately after harvesting and after a storage of 3 d (2 d at 4 °C and 1 d at 18 °C); the flesh firmness (FF), the soluble solids content (SSC), the acidity (A), and the titratable acidity (malic and citric acids) were then measured by destructive methods. Soft independent modeling of class analogy (SIMCA) analysis was used to classify spectra according to the ripening stage and the storage: partial least squares regression (PLS) models to predict FF, SSC, A, and the titratable acidity were also set-up for both just harvested and stored apricots. Spectral pretreatments and wavenumber selections were conducted on the basis of explorative principal component analysis (PCA). Apricot spectra were correctly classified in the right class with a mean classification rate of 87% (range: 80% to 100%). Test set validations of PLS models showed R² values up to 0.620, 0.863, 0.842, and 0.369 for FF, SSC, A, and the titratable acidity, respectively. The best models were obtained for the SSC and A and are suitable for rough screening; a lower power prediction emerged for the other maturity indices and the relative predictive models are not recommended. Practical Application : The results of the study could be used as a tool for the assessment of the ripening stage during the harvest and the quality during the postharvest storage of apricot fruits.     

Molecular Mechanisms and Physiological Changes behind Benign Tracheal and Subglottic Stenosis in Adults

Laryngotracheal stenosis (LTS) is a complex and heterogeneous disease whose pathogenesis remains unclear. LTS is considered to be the result of aberrant wound-healing process that leads to fibrotic scarring, originating from different aetiology. Although iatrogenic aetiology is the main cause of subglottic or tracheal stenosis, also autoimmune and infectious diseases may be involved in causing LTS. Furthermore, fibrotic obstruction in the anatomic region under the glottis can also be diagnosed without apparent aetiology after a comprehensive workup; in this case, the pathological process is called idiopathic subglottic stenosis (iSGS). So far, the laryngotracheal scar resulting from airway injury due to different diseases was considered as inert tissue requiring surgical removal to restore airway patency. However, this assumption has recently been revised by regarding the tracheal scarring process as a fibroinflammatory event due to immunological alteration, similar to other fibrotic diseases. Recent acquisitions suggest that different factors, such as growth factors, cytokines, altered fibroblast function and genetic susceptibility, can all interact in a complex way leading to aberrant and fibrotic wound healing after an insult that acts as a trigger. However, also physiological derangement due to LTS could play a role in promoting dysregulated response to laryngo-tracheal mucosal injury, through biomechanical stress and mechanotransduction activation. The aim of this narrative review is to present the state-of-the-art knowledge regarding molecular mechanisms, as well as mechanical and physio-pathological features behind LTS.     

Biological Effects of Cyclin-Dependent Kinase Inhibitors Ribociclib,Palbociclib and Abemaciclib on Breast Cancer Bone Microenvironment

The CDK4/6 inhibitors (CDKi) palbociclib, ribociclib, and abemaciclib are currently approved in combination with anti-estrogen therapy for the treatment of advanced and/or metastatic hormone receptor-positive/HER2-neu-negative breast cancer patients. Given the high incidence of bone metastases in this population, we investigated and compared the potential effects of palbociclib, ribociclib, and abemaciclib on the breast cancer bone microenvironment. Primary osteoclasts (OCs) and osteoblasts (OBs) were obtained from human monocyte and mesenchymal stem cells, respectively. OC function was evaluated by tartrate-resistant acid phosphatase assay and real-time PCR; OB activity was assessed by an alizarin red assay. OB/breast cancer co-culture models were generated via the seeding of MCF-7 cells on a layer of OBs, and tumor cell proliferation was analyzed using flow cytometry. Here, we showed that ribociclib, palbociclib, and abemaciclib exerted similar inhibitory effects on the OC differentiation and expression of bone resorption markers without affecting OC viability. On the other hand, the three CDKi did not affect the ability of OB to produce bone matrix, even if the higher doses of palbociclib and abemaciclib reduced the OB viability. In OB/MCF-7 co-culture models, palbociclib demonstrated a lower anti-tumor effect than ribociclib and abemaciclib. Overall, our results revealed the direct effects of CDKi on the tumor bone microenvironment, highlighting differences potentially relevant for clinical practice.     

CFD model performance benchmark of fast filling simulations of hydrogen tanks with pre-cooling

High gas temperatures can be reached inside a hydrogen tank during the filling process because of the large pressure increase (up to 70–80 MPa) and because of the short time (∼3 min) of the process. High temperatures can potentially jeopardize the structural integrity of the storage system and one of the strategies to reduce the temperature increase is to pre-cool the hydrogen before injecting it into the tank. Computational Fluid Dynamics (CFD) tools have the capabilities of capturing the flow field and the temperature rise in the tank. The results of CFD simulations of fast filling with pre-cooling are shown and compared with experimental data to assess the accuracy of the CFD model.     

CFD analysis of fast filling scenarios for 70 MPa hydrogen type IV tanks

High injection pressure is combined with high refueling rate for vehicles storing pressurized gaseous hydrogen onboard. As a drawback, high temperatures are developed inside the tank, which can jeopardize the structural integrity of the storage system. Computational Fluid Dynamics (CFD) codes already proved to be a valuable tool for predicting the temperature distribution within the tank during fast refueling. Results of hydrogen fast filling CFD simulations for a type IV tank, filled to 70 MPa at different working conditions are presented as follow up of the CFD model validation performed against experimental data. Alternative rates of pressure rise, adiabatic and cold filling are investigated to evaluate the effect on maximum hydrogen temperatures inside the tank. Results confirmed that the developed CFD model could be a suitable tool for investigating fast filling scenarios when experimental data are not yet available or of difficult realization.     

Thin-film solar cells on commercial ceramic tiles

Amorphous silicon solar cells were deposited on porcelain stoneware tiles in order to develop a fully integrated PV building element. In a previous work we demonstrated the feasibility of adopting porcelain stoneware tiles as thin-film solar cell substrates and we fabricated solar cells on “industrial-level” ceramic substrates showing more than 4% efficiency. In this study we focus our attention on larger area devices deposited on tiles. As the active area increases additional problems arise from the surface of the substrate. In particular we find that short-circuit paths originate from the unfavorable properties of the substrate tiles (roughness, porosity, etc.) having dramatic consequences on the performance of larger area devices. With the assumption that spot-like regions, in which the back layer and the front layer are in electrical contact (local short-circuits), are present all over the device, we propose a new device structure to overcome the substrate drawbacks. A new contacts arrangement was designed in order to minimize the shunting effect of short-circuit paths. As a result an initial efficiency of 2.5% has been obtained using the new device structure for devices deposited on a PV mini-module tile.     

Double emulsions (W/O/W): physical characteristics and perceived intensity of salty taste

This study addressed the correlation between physical characteristics of double emulsions and sensory perception, as the microstructure of these systems may provide the mechanism to understanding the initial cause of the altered salty taste. Thus, double emulsions (W/O/W) were prepared using different volumes of the internal aqueous phase while maintaining the same fat and sodium contents in the evaluated systems. Polyglycerol polyricinoleate (PGPR) and tween 80 were used as hydrophobic and hydrophilic emulsifiers, respectively. After preparation, the samples were stored at 25 °C for 4 days and submitted to analysis of optical microscopy, distribution and polydispersity of the oil droplets size, electrical conductivity, rheological behaviour and sensorial analysis. It was found that the use of different emulsifier concentrations (PGPR) did not influence the physical characteristics of the emulsions with the same formulation, but emulsions with different internal aqueous phase concentrations presented different results. These distinct characteristics may have influenced sensorial perception, as the emulsion with higher internal phase concentration was considered saltier. Thus, it can be concluded that structural differences of the double emulsions can be used to decrease the sodium contents without perceivable changes in salty taste.     

Vacuum impregnation of chitosan‐based edible coating in minimally processed pumpkin

The goal of this research was to evaluate the use of vacuum impregnation (VI) and soaking techniques (ST) in the application of edible coatings of chitosan and chitosan + lauric acid to minimally processed pumpkins (MPP). The vacuum impregnation method led to greater component incorporation (5.9% and 1.75%, respectively) in the pumpkins when compared to soaking and consequently the formation of more uniform, thicker coatings (25.6 and 22.3 μm, respectively). However, VI caused greater changes in pH, acidity, colour and firmness. Relating to water content and carotenoid content, noncoated pumpkins presented greater losses during the storage period, regardless of impregnation method. The pumpkins with edible coatings, regardless of method, presented lower numbers of psychrotrophic micro‐organisms and coliforms during the storage period. Therefore, soaking was considered the best method for the application of chitosan‐based edible coatings to minimally processed pumpkins, as it led to smaller changes in the properties of the product.     

Archaeological Arsenical Bronzes and Equilibrium in the As-Cu System

Metallurgical and Materials Transactions B - Understanding the effects of impurities, segregation, undercooling, and solidification velocity is necessary to reconstruct prehistoric As-Cu alloy...