Performance Analysis of Piezoelectric Energy Harvesting System.

[EN] This paper analyzes a piezoelectric system made of a smart lead zirconate material. The system is composed of a monolithic PZT (piezoelectric ceramic) plate made of a ceramic-based piezoelectric material. The experiment was conducted on a test stand with a GUNT HM170 wind tunnel and a special measurement system. The developed bluff-body shape mounted on an elastic beam with a piezoelectric was mounted on a mast with arms. Springs were fixed on the arms to limit the movement of the test object. Air flow velocity in the wind tunnel and forced vibration frequencies were changed during the tests. The recorded parameters were an output voltage signal from the piezoelectric element and linear accelerations at selected points of the test object. The highest energy efficiency of the tested system was specified from mechanical vibrations and air flow. The results of the tests are a resonance curve for the tested system and a correlation of RMS voltage and acceleration as a function of the velocity of air flow for the excitation frequency f ranging from 1 to 6 Hz. The tests specified the area where the highest output voltage under the given excitation conditions is generated.Publication was supported by the program of the Polish Ministry of Science and Higher Education under the project DIALOG 0019/DLG/2019/10 in the years 2019¿2021.Ambrozkiewicz, B.; Czyz, Z.; Staczek, P.; Tiseira, A.; Garcia Tiscar, J. (2022). Performance Analysis of Piezoelectric Energy Harvesting System. Advances in Science and Technology Research Journal. 16:179-185. https://doi.org/10.12913/22998624/1562151791851

Organometallic ciprofloxacin conjugates with dual action: synthesis, characterization, and antimicrobial and cytotoxicity studies

The synthesis, characterization and biological activity of six bioorganometallic conjugates of ciprofloxacin with ferrocenyl, ruthenocenyl and cymantrenyl entities are described. Their antimicrobial activities were investigated against Gram-positive bacteria, Gram-negative bacteria and bloodstream forms of Trypanosoma brucei. Furthermore, the morphological changes of bacterial cells upon treatment with the conjugates were examined by scanning electron microscopy. In addition, the cytotoxicity of the conjugates against tumor and normal mammalian cells was also investigated. The results showed that conjugation of an organometallic moiety can significantly enhance the antimicrobial activity of the antibiotic ciprofloxacin drug. It was found that N-alkyl cymantrenyl and ruthenocenyl ciprofloxacin conjugates were the most effective derivatives although other conjugates also showed significant antimicrobial activity. The increase in the antimicrobial activity was most likely due to two independent mechanisms of action. The first mechanism is due to the bacterial topoisomerase inhibitory activity of ciprofloxacin while the second mechanism can be attributed to the generation of reactive oxygen species caused by the organometallic moiety. The presence of two modes of action enables the conjugates to kill bacteria in their stationary growth phase and to overcome the drug resistance of S. aureus strains. In addition, the conjugates showed promising selectivity toward bacterial and parasitic cells over mammalian cells

An Induced Hypersensitive-Like Response Limits Expression of Foreign Peptides via a Recombinant TMV-Based Vector in a Susceptible Tobacco

BACKGROUND: By using tobacco mosaic virus (TMV)-based vectors, foreign epitopes of the VP1 protein from food-and-month disease virus (FMDV) could be fused near to the C-terminus of the TMV coat protein (CP) and expressed at high levels in susceptible tobacco plants. Previously, we have shown that the recombinant TMV vaccines displaying FMDV VP1 epitopes could generate protection in guinea pigs and swine against the FMDV challenge. Recently, some recombinant TMV, such as TMVFN20 that contains an epitope FN20 from the FMDV VP1, were found to induce local necrotic lesions (LNL) on the inoculated leaves of a susceptible tobacco, Nicotiana tabacum Samsun nn. This hypersensitive-like response (HLR) blocked amplification of recombinant TMVFN20 in tobacco and limited the utility of recombinant TMV vaccines against FMDV. METHODOLOGY/PRINCIPAL FINDINGS: Here we investigate the molecular mechanism of the HLR in the susceptible Samsun nn. Histochemical staining analyses show that these LNL are similar to those induced in a resistant tobacco Samsun NN inoculated with wild type (wt) TMV. The recombinant CP subunits are specifically related to the HLR. Interestingly, this HLR in Samsun nn (lacking the N/N'-gene) was able to be induced by the recombinant TMV at both 25°C and 33°C, whereas the hypersensitive response (HR) in the resistant tobacco plants induced by wt TMV through the N/N'-gene pathways only at a permissive temperature (below 30°C). Furthermore, we reported for the first time that some of defense response (DR)-related genes in tobacco were transcriptionally upregulated during HLR. CONCLUSIONS: Unlike HR, HLR is induced in the susceptible tobacco through N/N'-gene independent pathways. Induction of the HLR is associated with the expression of the recombinant CP subunits and upregulation of the DR-related genes

The why and how of DNA unlinking

The nucleotide sequence of DNA is the repository of hereditary information. Yet, it is now clear that the DNA itself plays an active role in regulating the ability of the cell to extract its information. Basic biological processes, including control of gene transcription, faithful DNA replication and segregation, maintenance of the genome and cellular differentiation are subject to the conformational and topological properties of DNA in addition to the regulation imparted by the sequence itself. How do these DNA features manifest such striking effects and how does the cell regulate them? In this review, we describe how misregulation of DNA topology can lead to cellular dysfunction. We then address how cells prevent these topological problems. We close with a discussion on recent theoretical advances indicating that the topological problems, themselves, can provide the cues necessary for their resolution by type-2 topoisomerases

Plant virus particles carrying tumour antigen activate TLR7 and induce high levels of protective antibody

Induction of potent antibody is the goal of many vaccines targeted against infections or cancer. Modern vaccine designs that use virus-like particles (VLP) have shown efficacy for prophylactic vaccination against virus-associated cancer in the clinic. Here we used plant viral particles (PVP), which are structurally analogous to VLP, coupled to a weak idiotypic (Id) tumour antigen, as a conjugate vaccine to induce antibody against a murine B-cell malignancy. The Id-PVP vaccine incorporates a natural adjuvant, the viral ssRNA, which acts via TLR7. It induced potent protective anti-Id antibody responses in an in vivo mouse model, superior to the "gold standard" Id vaccine, with prevalence of the IgG2a isotype. Combination with alum further increased antibody levels and maintained the IgG2a bias. Engagement of TLR7 in vivo was followed by secretion of IFN-? by plasmacytoid dendritic cells and by activation of splenic CD11chi conventional dendritic cells. The latter was apparent from up-regulation of co-stimulatory molecules and from secretion of a wide range of inflammatory cytokines and chemokines including the Th1-governing cytokine IL-12, in keeping with the IgG2a antibody isotype distribution. PVP conjugates are a novel cancer vaccine design, offering an attractive molecular form, similar to VLP, and providing T-cell help. In contrast to VLP, they also incorporate a safe "in-built" ssRNA adjuvant

Feelings for Five-O: An Analysis of Factors Affecting Baltimore Youth's Perceptions of Police

This research focuses on the factors that influence youth perceptions of police and the implications on legal cynicism in the United States. Through interviews with 151 Baltimore City youth, I analyze the impact of institutional resources, police interactions, and gender on youth opinions towards law enforcement. By giving each interviewee a score that rated their level of participation in resources and level of interactions with police, I was able to uncover themes within different groups of youth supplemented by the qualitative interview data. Through this analysis, I found that kids with participation in more institutional resources and less interactions with officers ultimately had more positive perceptions of police. Further, I found that boys had a more negative perception of police than girls. In researching and analyzing these factors affecting youth perceptions, I hope to highlight the impacts of police on the quality of life for disadvantaged youth and their perceptions

Feelings for Five-O: An Analysis of Factors Affecting Baltimore Youth's Perceptions of Police

This research focuses on the factors that influence youth perceptions of police and the implications on legal cynicism in the United States. Through interviews with 151 Baltimore City youth, I analyze the impact of institutional resources, police interactions, and gender on youth opinions towards law enforcement. By giving each interviewee a score that rated their level of participation in resources and level of interactions with police, I was able to uncover themes within different groups of youth supplemented by the qualitative interview data. Through this analysis, I found that kids with participation in more institutional resources and less interactions with officers ultimately had more positive perceptions of police. Further, I found that boys had a more negative perception of police than girls. In researching and analyzing these factors affecting youth perceptions, I hope to highlight the impacts of police on the quality of life for disadvantaged youth and their perceptions

El euro digital: diseño y razones para su creación

Desde el año 2020 el Banco Central Europeo está investigando el posible lanzamiento del llamado euro digital, una moneda que sólo existiría electrónicamente, que tendría el mismo valor que el euro, respaldada igual que este por el Banco Central Europeo, pero que a diferencia de los depósitos bancarios, no sería un pasivo de la banca comercial sino un pasivo del Banco Central Europeo. El diseño de este euro digital es de vital importancia para el sistema bancario. ¿Sería el euro digital una competencia a los depósitos bancarios? ¿Servirá únicamente para realizar pagos o podría ser un instrumento de inversión? ¿Quién proporcionaría y mantendría los monederos digitales necesarios para guardar los euros digitales? Estas son solo algunas de las muchas preguntas que el diseño del euro digital plantea. Finalmente, en el trabajo se investigarán las razones por las que el Banco Central Europeo se plantea la posible creación del euro digital cuando no se percibe en la sociedad una demanda de una moneda únicamente digital respaldada por el banco central. De hecho, la ciudadanía ya puede realizar pagos con tarjetas y transferencias bancarias en euros electrónicos, vía el sistema bancario. La competencia de las criptomonedas y la creación por parte de otros bancos centrales de sus propias divisas digitales podrían tener mucho que ver con la razón de ser del euro digital.Facultad de Ciencias de la EmpresaUniversidad Politécnica de Cartagen

Feelings for Five-O: An Analysis of Factors Affecting Baltimore Youth's Perceptions of Police

This research focuses on the factors that influence youth perceptions of police and the implications on legal cynicism in the United States. Through interviews with 151 Baltimore City youth, I analyze the impact of institutional resources, police interactions, and gender on youth opinions towards law enforcement. By giving each interviewee a score that rated their level of participation in resources and level of interactions with police, I was able to uncover themes within different groups of youth supplemented by the qualitative interview data. Through this analysis, I found that kids with participation in more institutional resources and less interactions with officers ultimately had more positive perceptions of police. Further, I found that boys had a more negative perception of police than girls. In researching and analyzing these factors affecting youth perceptions, I hope to highlight the impacts of police on the quality of life for disadvantaged youth and their perceptions