High Granularity approaches for effective energy delivery from Photovoltaic Sources

Silicon solar cell technology is a fully mature technology but the need to compete with traditional and other renewable energy sources urges to improve the overall efficiency of a photovoltaic (PV) system by a significant amount. Regardless of the solar panel efficiency, the difference between the nominal performance of a PV system and the energy actually produced is quite high, and it can be quantified in the order of 20%. A loss term, often underestimated, depends on possible failure of the Maximum Power Point Tracking (MPPT) algorithms in the presence of multiple maximum power points in power-voltage characteristic, arising in mismatch conditions. This work proposes High Granularity (HG) approaches in order to improve the PV energy yield: a monitoring strategy, a modeling and a power flux control of the whole PV system, all performed at level of single elementary source (i.e., PV cell or PV panel). An innovative HG sensor infrastructure was developed, and the measurements were exploited to perform an automatic PV system reconfiguration, and to design an information based MPPT. Moreover, the data validated a circuit HG model describing the PV system at single cell level, which also accounts for the electrothermal effect. The model was exploited in an automatic tool which translates an AutoCAD project of a PV plant in an equivalent circuit netlist. Finally, the results were employed to investigate the effectiveness of distributed power conversion – in particular the efficiency of the multilevel cascaded H bridge converter controlled by means of an innovative strategy, which overcomes some issues related to the need of performing a distributed MPPT, was assessed

Accurate Maximum Power Tracking in Photovoltaic Systems Affected by Partial Shading

A maximum power tracking algorithm exploiting operating point information gained on individual solar panels is presented. The proposed algorithm recognizes the presence of multiple local maxima in the power voltage curve of a shaded solar field and evaluates the coordinated of the absolute maximum. The effectiveness of the proposed approach is evidenced by means of circuit level simulation and experimental results. Experiments evidenced that, in comparison with a standard perturb and observe algorithm, we achieve faster convergence in normal operating conditions (when the solar field is uniformly illuminated) and we accurately locate the absolute maximum power point in partial shading conditions, thus avoiding the convergence on local maxima

Synthesis of Oligonucleotide Conjugates and Phosphorylated Nucleotide Analogues: An Improvement to a Solid Phase Synthetic Approach

An improvement to our solid phase strategy to generate pharmacologically interesting molecule libraries is proposed here. The synthesis of newo-chlorophenol-functionalised solid supports with very high loading (0.18–0.22 meq/g for control pore glass (CPG) and 0.25–0.50 meq/g for TG) is reported. To test the efficiency of these supports, we prepared nucleotide and oligonucleotide models, and their coupling yields and the purity of the crude detached materials were comparable to previously available results. These supports allow the facile and high-yield preparation of highly pure phosphodiester and phosphoramidate monoester nucleosides, conjugated oligonucleotides, and other yet unexplored classes of phosphodiester and phosphoramidate molecules

Study of the effect of different breast implant surfaces on capsule formation and host inflammatory response in an animal model

Background: Breast implants are biomaterials eliciting a physiological and mandatory foreign body response. Objectives: The authors designed an animal study to investigate the impact of different implant surfaces on the formation of the periprosthetic capsule, the inflammatory response, and the cellular composition. Methods: The authors implanted 1 scaled-down version of breast implants by different manufactures on 70 female Sprague Dawley rats. Animals were divided into 5 groups of 14 animals. Group A received a smooth implant (Ra ≈ 0.5 µm) according to the ISO 14607-2018 classification, Group B a smooth implant (Ra ≈ 3.2 µm), Group C a smooth implant (Ra ≈ 5 µm), Group D a macrotextured implant (Ra ≈ 62 µm), and Group E a macrotextured implant (Ra ≈ 75 µm). At 60 days, all animals received a magnetic resonance imaging (MRI), and 35 animals were killed and their capsules sent for histology (capsule thickness, inflammatory infiltrate) and immunohistochemistry analysis (cellular characterization). The remaining animals repeated the MRI at 120 days and were killed following the same protocol. Results: MRI showed a thinner capsule in the smooth implants (Groups A-C) at 60 days (P < .001) but not at 120 days (P = .039), confirmed with histology both at 60 days (P = .005) and 120 days (P < .001). Smooth implants (Groups A-C) presented a mild inflammatory response at 60 days that was maintained at 120 days and a high M2-Macrophage concentration (anti-inflammatory). Conclusions: Our study confirms that smooth implants form a thinner capsule, inferior inflammatory infiltrate, and a cellular composition that indicates a mild host inflammatory response. A new host inflammatory response classification is elaborated classifying breast implants into mild, moderate, and high

Synthesis and characterization of a mini-library of new conjugated d(TGGGAG) oligonucleotides with potential anti-HIV activity.

In the search for ODNs endowed with relevant antiviral properties, Hotoda and coworkers investigated a series of G-quadruplex-forming ODNs, finally focusing on modified d(TGGGAG) ODNs conjugated with aromatic residues at the 5-end. These were found to exhibit potent anti-HIV activity associated with low cytotoxicity when carrying at the 5′-end bulky aromatic residues. Recently we described a general approach to obtain a mini library of new d(TGGGAG) ODNs, conjugated with different aromatic groups at the 5’-end through a phosphodiester bond. Several modified sequences showed pronounced anti-HIV-1 activity and they showed high binding affinities for the HIV-1 envelope gp120 and gp41. In these structures the 5-end residues play a major role on the G-quadruplex stability, dramatically enhancing stability of the quadruplex complexes (Tm>20°C). With the final goal to expand the repertoire of accessible end-modified G-rich ODNs, and to get a more complete picture of their structure-activity relationships, we describe herein the synthesis and characterization of a mini-library of new d(5’TGGGAG3’) carrying hydrophobic groups at the 5’-end and 2-hydroxyethylphosphate group at the 3'-end, connected through phosphodiester and phosphoramidate bonds, respectively. In order to study the influence of the conjugation at the ends of the oligonucleotide chains on their ability to form quadruplex structures, a CD analysis was undertaken on the conjugated oligomers in comparison with the corresponding unmodified d(TGGGAG) oligomer

Breast implant associated anaplastic large cell lymphoma. proposal for a monitoring protocol

BACKGROUND: The authors report four cases of breast implant-associated anaplastic large cell lymphoma (ALCL) from a single institution and propose a multidisciplinary protocol. METHODS: From 2012 to 2014, four breast implant-associated ALCL cases were diagnosed. The authors performed the original operation, and no patients were referred to their practice. Cases 1, 2, and 4 were CD4/CD30/ALK ALCL with previous textured-implant reconstruction, whereas case 3 was CD8/CD30/ALK ALCL with previous polyurethane-implant augmentation. A retrospective study of all patients who underwent breast implant positioning was performed to identify any misdiagnosed cases. RESULTS: Of 483 patients, 226 underwent reconstruction with latissimus dorsi flap and prosthesis, 115 had skin-sparing/nipple-sparing mastectomy and prosthesis, 117 underwent an expander/implant procedure, and 25 underwent breast augmentation. Fifty-eight cases (12 percent) underwent implant replacement for capsular contracture, 15 (3.1 percent) experienced late-onset seroma, and four (0.83 percent) had both capsular contracture and seroma. Seventy-seven symptomatic patients (16 percent) underwent surgical revision (capsulectomy/capsulotomy) and/or seroma evacuation. The second look on histologic specimens did not identify misdiagnosed cases. A multidisciplinary protocol for suspected implant-associated ALCL was established. Ultrasound and cytologic examinations are performed in case of periprosthetic effusion. If implant-associated ALCL is diagnosed, implant removal with capsulectomy is performed. If disseminated disease is detected through positron emission tomography/computed tomography of the total body, the patient is referred to the oncology department. CONCLUSIONS: A multidisciplinary protocol is mandatory for both early diagnosis and patient management. Until definitive data emerge regarding the exact etiopathogenesis of breast implant-associated ALCL, the authors suggest offering only autologous reconstruction if patients desire it

New 23-phosphodiester derivatives of Silibin and DHS: synthesis and preliminary evaluation of antioxidant properties

Silybin is the major flavonolignan of silymarin which is widely used as a natural remedy for the treatment of cirrhosis, chronic hepatitis, and liver diseases associated with alcohol consumption and exposure to environmental toxins. Different studies recently made on the antiradical activity of silybin and DHS have elucidated the functional groups responsible for this activity. The results suggest that the C-23 position could be a site for useful modifications aimed to improve the bioactivity of silybin and/or DHS analogues. Recently we describe an efficient synthetic strategy to obtain a variety of new silybin and 2,3-dehydrosilybin (DHS) derivatives in which the 23-hydroxyl group was converted to a sulfate, phosphodiester, or amine group, using a solution-phase approach. The antioxidant properties of the new compounds were evaluated in a cellular model in vivo and most of them displayed an antioxidant activity comparable or higher to silybin and DHS. These results confirmed the assumption that modifications in position C–23 do not affect the radical scavenging activity of these analogues. With the final goal to expand the repertoire of silybin and DHS C-23 modified, we describe here the synthesis and preliminary evaluation of antioxidant properties of a variety of new silybin and DHS conjugated with different labels through a phosphodiester bond The antioxidative properties of the above-synthesized compounds were determined by free radical scavenging (DPPH) assay

siRNAs bearing aromatic residues in the 3’-overhang region

RNA interference (RNAi) is a biological process whereby small interfering RNA (siRNA) and microRNA (miRNA) silence gene expression in a sequence-specific manner. These effectors regulate gene expression through the RNA-induced silencing complex (RISC). It has been suggested that RISC preferentially selects and incorporates one of two strands of the siRNA duplex depending on its thermodynamic features and that the off-target effects of siRNAs can be correlated to the Tm of the duplex. The problem of unwanted incorporation of the passenger strand into RISC could be address altering the thermodynamic asymmetry of the duplex by using specific chemical modifications. Structural studies have revealed that the 3’-overhang region of the guide strand of siRNA is recognized by the PAZ domain and is accommodated into its hydrophobic binding pocket. We expected that aromatic-based modifications in 3’-overhang would enhance RISC selection of antisense strands of siRNA duplexes, reducing off-target effects induced by sense strands. In this study, we report the synthesis of siRNAs bearing diphenylpropylamine, tyramine and tryptamine units at the 3’-end of sense and antisense strands. We found thermodynamic stability of the conjugates was increased by these modifications. Furthermore, but not surprisingly, the modified duplexes were found to retain RNA-like A-type conformation. We also assessed the nuclease resistance of the modified siRNAs and found it was similar to those of unmodified siRNAs. These results prompted us to investigate the silencing activity of the siRNAs possessing the aromatic moiety in the 3’-end by in vitro experiments in mammalian cells

IL-10, IL-13, Eotaxin and IL-10/IL-6 ratio distinguish breast implant-associated anaplastic large-cell lymphoma from all types of benign late seromas

Breast implant-associated anaplastic large-cell lymphoma (BI-ALCL) is an uncommon peripheral T cell lymphoma usually presenting as a delayed peri-implant effusion. Chronic inflammation elicited by the implant has been implicated in its pathogenesis. Infection or implant rupture may also be responsible for late seromas. Cytomorphological examination coupled with CD30 immunostaining and eventual T-cell clonality assessment are essential for BI-ALCL diagnosis. However, some benign effusions may also contain an oligo/monoclonal expansion of CD30 + cells that can make the diagnosis challenging. Since cytokines are key mediators of inflammation, we applied a multiplexed immuno-based assay to BI-ALCL seromas and to different types of reactive seromas to look for a potential diagnostic BI-ALCL-associated cytokine profile. We found that BI-ALCL is characterized by a Th2-type cytokine milieu associated with significant high levels of IL-10, IL-13 and Eotaxin which discriminate BI-ALCL from all types of reactive seroma. Moreover, we found a cutoff of IL10/IL-6 ratio of 0.104 is associated with specificity of 100% and sensitivity of 83% in recognizing BI-ALCL effusions. This study identifies promising biomarkers for initial screening of late seromas that can facilitate early diagnosis of BI-ALCL

Harpin oligonucleotides forming G-quadruplexes: new aptamers with potential anti-HIV activity

Several G-rich synthetic oligodeoxyribonucleotides (ODNs) have shown promising biological properties, ranging from anticancer to anti-HIV activities. G-quadruplex formation was found to be a crucial prerequisite in determining these biological effects. Aptamers exhibiting anti-HIV activity represent an important class of potential therapeutics. Recently we described the synthesis and characterization of new d(TGGGAG) ODNs, conjugated with different aromatic groups at the 5’-end through a phosphodiester bond. The modified sequences showed a parallel stranded tetramolecular G-quadruplexes CD profile and a pronounced anti-HIV-1 activity. Herein, with the aim to use d(TGGGAG) as a lead sequence for a more effective anti-HIV agent, we propose the fully automated synthesis of new ODNs containing two d(TGGGAG) sequences whose 3-ends are joint by an hexaethylenglycole loop. CD analysis was undertaken on the 3’-3’ linked d(TGGGAG) hairpins in comparison with the corresponding unmodified oligomers. Besides, in order to study the influence of the conjugation at the ends of the harpin chains on their ability to stabilize quadruplex structures and on their anti-HIV activity, different conjugated oligomers have been studied