ARTICLE | doi:10.20944/preprints202305.1421.v2
Subject: Engineering, Architecture, Building And Construction Keywords: Latin America heritage; Reform in cultural heritage management; UNESCO site at risk
Online: 9 June 2023 (05:44:45 CEST)
Since 2017 Cartagena UNESCO World Heritage has threatened to be categorized as "in Danger" by UNESCO. This research analyzes two main critical aspects, Governance and Current state of the Site. Regarding Governance, the study aims to identify strengths, weaknesses, opportunities and treats in the UNESCO Site. Exemplary heritage management systems are studied to propose an adaptable management approach specifically for Cartagena. On the other hand, a comprehensive analysis is conducted utilizing a photographic report that highlights the major issues arising from inadequate heritage management. Hyperspectral images obtained from a previous study are employed to identify vegetation and asbestos-cement roofs within the cultural heritage Site. The study reveals that the ambiguity surrounding decision-making authority for heritage management, distributed between the Mayor's Office and the Ministry of Culture, is a primary challenge. This fragmentation has resulted in duplicated efforts and a lack of coordinated action, significantly compromising the conservation and protection of the cultural heritage Site. Moreover, twelve current shortcomings of cultural heritage in Cartagena are identified through authors' five-year on-site regular visits, photographic reports and observation. To address the prevailing concerns, a new line of command for cultural heritage management is proposed as the most effective means of tackling these challenges. Additionally, general recommendations are presented to mitigate the existing problems and prevent the classification of Cartagena's heritage as "at risk" by UNESCO in the near future. This research provides a scientific perspective, drawing upon years of experience studying heritage and residing in the city, devoid of political influences or conflicts of interest.
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: screen printed electrodes; Ag nanoparticles; drop-casting; spin-coating; nanoprisms; heavy metals; Differential pulse anodic stripping voltammetric; electrocatalysis
Online: 5 August 2019 (04:55:05 CEST)
The screen-printed carbon nanofibers electrodes (SPCNFE) represent an alternative with great acceptance due to their results, as well as their low impact for the environment. In order to improve their performance, in the present work they were modified with silver nanoparticles (Ag-NPs) and electrochemically characterized by using anodic stripping voltammetry. From the Ag-NPs synthesis, silver seeds (Ag-NS) and silver nanoprisms (Ag-NPr) were obtained. The Ag-NPs formation was confirmed by micrographs where Ag-NPs with diameters of 12.20±0.04 nm for Ag-NS, and 20.40±0.09 nm for Ag-NPr were observed. The electrodes were modified by using three different deposition methods: drop-casting, spin-coating and in-situ approaches. It was observed that the last methodology showed a low amount of Ag-NS deposited on the electrode surface and a deep alteration of this surface. Those facts suggested that the in situ synthesis methodology were not appropriate for the determination of heavy metals and it was discarded. The incorporation of the nanoparticles by spin-coating and drop-casting strategies showed different spatial distribution on the electrode surface as proved by scanning electron microscopy. The electrodes modified by these strategies, were evaluated for the cadmium(II) and lead(II) detection using differential pulse anodic stripping voltammetry, obtaining detection limit values of 2.1 and 2.8 µg L-1, respectively. The overall results showed that the incorporation route does not change directly the electrocatalytic effect of the nanoparticles, but the shape of these nanoparticles (spherical for seeds and triangular for prisms) has a preferential electrocatalytical enhancement over Cd(II) or Pb(II).
REVIEW | doi:10.20944/preprints202306.2260.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: epicatechin; skeletal muscle; muscular atrophy; catechins; myogenic regulatory factors
Online: 30 June 2023 (14:49:48 CEST)
Epicatechin has been described as a polyphenol compound that promotes skeletal muscle restructuring, by expressing muscle regulation factors, activation of satellite cells and modulation of the main pathways associated with catabolism. However, the literature shows contrasting results of therapeutic effects and treatment protocols. Thus, the aim of this systematic review was to analyze the current literature addressing the molecular mechanism and clinical protocol of epicatechin on skeletal muscular atrophy in humans and animals. A search was conducted in PubMed/MEDLINE, Embase, Web of Science, and Cochrane Library databases. The qualitative analysis showed a prevalence of the inhibitory action of epicatechin in myostatin expression and atrogenes FOXO, MAFbx and MuRF1. Epicatechin showed positive effects on increased follistatin and on the activation of the myogenic regulatory factors (Myf5, MyoD and myogenin). In addition, the studies evidenced the impact of epicatechin on the mitochondrias' biosynthesis in muscle fibers, activation of the signaling pathway of AKT/mTOR protein synthesis, and improvement of skeletal musculature performance, particularly when associated with physical training. Epicatechin showed promising clinical applicability through beneficial results under conditions that negatively affect the skeletal musculature. However, there is no protocol standardization allowing to draw more specific conclusions on its therapeutic use.