Browsing by Issue Date, starting with "2023-12-01"
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- Diversity of cultured heterotrophic bacteria from polar sea waters and sea ice ecosystems: A unique source for blue biotechnologyPublication . Tinto, Eleonora; Power, Deborah M.; Acinas, Silvia G.The discovery of the CRISPR-Cas system, a prokaryotic defense mechanism, has revolutionized genomics and biotechnology. This system uses Cas nucleases to precisely cut DNA sequences by relying on a protospacer adjacent motif (PAM). Cas9, especially SpCas9 from Streptococcus pyogenes, has been widely studied for genome engineering due to its wellunderstood biochemistry and short PAM sequence. However, its limitations in the recognition of PAM sequences have led researchers to look for natural orthologs of Cas9. This study focuses on the remote areas of the polar regions, where extreme conditions result in unique environments. During three expeditions - PI-ICE (2019) and ANTOM-2 (2022) in Antarctica, and QikIce in the Arctic (2023) – seawater, sea ice and brine samples were collected. Subsequent cultivation showed differences in bacterial growth and taxa enrichment between seawater and sea ice heterotrophic bacteria. Furthermore, the taxonomic analysis of 199 colonies revealed similarities and variations in their biodiversity across habitats, depths and regions. In particular, in ANTOM-2, seawater samples from different depths showed a prevalence of Gammaproteobacteria in deeper layers, while Alphaproteobacteria dominated the photic zones. Dominant genera included Sulfitobacter, Pseudoalteromonas and Shewanella. Five out of seven deep-sea genera were found in photic zones, including Bacillus, Pseudoalteromonas, Pseudomonas, Psychroserpens and Winogradskyella. In contrast, sea ice isolates from PI-ICE showed an absence of Alphaproteobacteria, with Flavobacteriia and Gammaproteobacteria dominating. Notable genera were Flavobacterium, Psychrobacter and Chryseobacterium. During the QikIce expedition, Bacilli and Flavobacteriia were predominant, while three genera differed from those found in Antarctica: Planomicrobium, Maribacter and Octadecabacter. In the final phase of the study, the design of two primer pairs led to the amplification of potential Cas9 sequences from three Flavobacterium isolates, opening up new avenues for future efforts. This research highlights the importance of exploring extreme environments, such as polar regions, for biotechnological discoveries and expanding the CRISPR-Cas toolbox.
- Using satellite data to monitor Groundwater drought in the Algarve regionPublication . Neves, Maria C.; Moreira, Elsa; Costa, LuisGroundwater drought presents significant economic and societal challenges, highlighting the need for effective monitoring and early warning systems at local and regional scales. Despite its vital role in water supply and irrigation, groundwater drought is often not adequately monitored in national operational systems. While the propagation of meteorological drought through hydrological systems has been extensively studied in various parts of the world, there is a lack of groundwater drought monitoring at an integrated basin-scale based on groundwater data. Long-term hydrological drought is often assessed using meteorological drought indices like SPI or SPEI with long periods of accumulation (12, 24 or 48 months time scales). However, most studies recognize that the accumulation periods necessary to achieve maximum correlation with groundwater observations exhibit high spatial variability due to the complexity of local hydrogeological conditions. This study aims to address this gap on groundwater drought monitoring in the Algarve by investigating the suitability of GRACE-based drought indices and ground-based drought indices derived from piezometer measurements for monitoring and predicting groundwater droughts.
- Prophylactic negative pressure wound therapy in patients with closed surgical wound: an integrative reviewPublication . Tendeiro, Daniela; Mestre, Teresa; Martins, Helga; Carmo, AndréSurgical site infection is the leading healthcare-associated infection and a major contributor to rising healthcare costs. Implementation of measures to reduce this problem, particularly the prophylactic use of negative pressure wound therapy, may be an effective and promising method to reduce the risk of surgical site infection in patients with closed surgical wounds. The aim of the study was to identify the effectiveness of negative pressure wound therapy as a prophylactic measure in reducing the risk of surgical site infection in patients with a closed surgical wound. Whittemore and Knafl's five-step integrative review framework was carried out using three electronic databases. MEDLINE with Full-text, CINAHL with Full-text and Academic Search Complete were searched through the EBSCOhost Web platform. Articles search publication date was between 2018 and 2022. Nine studies were identified that addressed the effectiveness of prophylactic negative pressure wound therapy in reducing the risk of surgical site infection in the patient with a closed surgical wound. There was also evidence of effectiveness in reducing surgical wound dehiscence, drainage output and drainage time, as well as reducing the incidence of hospital readmissions and the need for wound debridement. Prophylactic negative pressure wound therapy can be an effective treatment option, among others, in reducing the risk of surgical site infection in patients with a closed surgical wound. This evidence promotes improved clinical practice regarding the management of the closed surgical wound, promoting health gains for patients.