Browsing by Issue Date, starting with "2023-01-11"
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- Vertical transmission and antifungal susceptibility profile of yeast isolates from the oral cavity, gut, and breastmilk of mother–child pairs in early lifePublication . Azevedo, Maria João; Araújo, Ricardo; Campos, Joana; Campos, Carla; Ferreira, Ana Filipa; Falcão-Pires, Inês; Ramalho, Carla; Zaura, Egija; Pinto, Eugénia; Sampaio-Maia, BeneditaYeast acquisition begins at birth; however, the contribution of the mother on yeast trans mission to the offspring and associated resistance is yet to be clarified. The aim of this study was to explore the vertical transmission of yeasts and their antifungal susceptibility profile in early life. Oral, fecal, and breastmilk samples were collected from 73 mother–child pairs four to twelve weeks after delivery and cultured on Sabouraud dextrose agar with chloramphenicol. The isolates were identified by MALDI-TOF MS. The vertical transmission was studied by microsatellite genotyping. Antifungal susceptibility was determined for fluconazole, voriconazole, miconazole, anidulafungin, and nystatin by broth microdilution assay, following CLSI–M60 guidelines. A total of 129 isolates were identified from 53% mother–child pairs. We verified the vertical transmission of Candida albicans (n = three mother–child pairs) and Candida parapsilosis (n = one mother–child pair) strains, includ ing an antifungal resistant strain transmitted from breastmilk to the gut of a child. Most isolates were susceptible to the tested antifungals, with the exception of four C. albicans isolates and one R. mucilaginosa isolate. The vertical transmission of yeasts happens in early life. This is the first work that demonstrated the role of the mother as a source of transmission of antifungal-resistant yeasts to the child.
- Improving the antimycobacterial drug Clofazimine through formation of organic salts by combination with fluoroquinolonesPublication . Bento, Clara M.; Silva, Ana Teresa; Mansano, Bruno; Aguiar, Luísa; Teixeira, Cátia; Gomes, Maria Salomé; Gomes, Paula; Silva, Tânia; Ferraz, RicardoThis work reports the synthesis, structural and thermal analysis, and in vitro evaluation of the antimicrobial activity of two new organic salts (OSs) derived from the antimycobacterial drug clofazimine and the fluoroquinolones ofloxacin or norfloxacin. Organic salts derived from active pharmaceutical ingredients (API-OSs), as those herein disclosed, hold promise as cost-effective formulations with improved features over their parent drugs, thus enabling the mitigation of some of their shortcomings. For instance, in the specific case of clofazimine, its poor solubility severely limits its bioavailability. As compared to clofazimine, the clofazimine-derived OSs now reported have improved solubility and thermostability, without any major deleterious effects on the drug’s bioactivity profile.
- Outage Probability of V2V Multiple-Antenna Rice Fading Links with Explicit Ground ReflectionPublication . Gutiérrez Gaitán, Miguel; Samano-Robles, Ramiro; Rodriguez, JonathanThis paper investigates the improvement in terms of outage probability of a vehicle-to-vehicle (V2V) communication link with respect to the density of antennas used at each vehicle end. The objective is to find a trade-off between system complexity and communication performance considering that the deterministic component of the link is affected explicitly by multiple ground reflections (self-interference). The antennas are assumed to be located at regularly distributed positions across the surface of contiguous vehicles. Part of the work assumes symbol repetition at the transmitter side, and different signal combining mechanisms at the receiver side, namely, maximum-ratio and equal-gain combining (MRC and EGC, respectively). The objective is to minimize outage probability of the link with deterministic and stochastic channel components (Rice-distributed), where the line-of-sight (LOS) is affected by multi-ray ground reflections as an extension of the well-known two-ray model. This scenario is considered more realistic for V2V scenarios due to the potential proximity of ground to the antenna elements. The outage probability is calculated over a range of inter-vehicle distances with respect to the free-space loss solution. The results show that performance is improved even for a relatively small number of antennas and that a critical point is reached beyond which improvement is only differential. This suggests that an optimum trade-off can be obtained to ensure a value of outage probability with a complexity constraint over a range of inter-vehicle distances.