Julien Wist

Bio: Julien Wist is an academic researcher from University of Valle. The author has contributed to research in topics: Medicine & Internal medicine. The author has an hindex of 13, co-authored 42 publications receiving 667 citations. Previous affiliations of Julien Wist include National University of Colombia & Murdoch University.

Evaluation of photocatalytic disinfection of crude water for drinking-water production

Abstract: TiO2-photocatalysis disinfection experiments were carried out with both E. coli in distilled water and natural water samples from the Cauca River (Cali, Colombia). The experiments performed with E. coli in distilled water showed no increase in cell concentration after the treated solution was left in the dark for 24 h. However, the experiments carried out with natural water samples showed drastic culturable cell concentration increase 24 h after stopping the irradiation. This shows the lack of residual effect of TiO2-photocatalysis.

Incomplete Systemic Recovery and Metabolic Phenoreversion in Post-Acute-Phase Nonhospitalized COVID-19 Patients: Implications for Assessment of Post-Acute COVID-19 Syndrome.

Abstract: We present a multivariate metabotyping approach to assess the functional recovery of nonhospitalized COVID-19 patients and the possible biochemical sequelae of "Post-Acute COVID-19 Syndrome", colloquially known as long-COVID. Blood samples were taken from patients ca. 3 months after acute COVID-19 infection with further assessment of symptoms at 6 months. Some 57% of the patients had one or more persistent symptoms including respiratory-related symptoms like cough, dyspnea, and rhinorrhea or other nonrespiratory symptoms including chronic fatigue, anosmia, myalgia, or joint pain. Plasma samples were quantitatively analyzed for lipoproteins, glycoproteins, amino acids, biogenic amines, and tryptophan pathway intermediates using Nuclear Magnetic Resonance (NMR) spectroscopy and mass spectrometry. Metabolic data for the follow-up patients (n = 27) were compared with controls (n = 41) and hospitalized severe acute respiratory syndrome SARS-CoV-2 positive patients (n = 18, with multiple time-points). Univariate and multivariate statistics revealed variable patterns of functional recovery with many patients exhibiting residual COVID-19 biomarker signatures. Several parameters were persistently perturbed, e.g., elevated taurine (p = 3.6 × 10-3 versus controls) and reduced glutamine/glutamate ratio (p = 6.95 × 10-8 versus controls), indicative of possible liver and muscle damage and a high energy demand linked to more generalized tissue repair or immune function. Some parameters showed near-complete normalization, e.g., the plasma apolipoprotein B100/A1 ratio was similar to that of healthy controls but significantly lower (p = 4.2 × 10-3) than post-acute COVID-19 patients, reflecting partial reversion of the metabolic phenotype (phenoreversion) toward the healthy metabolic state. Plasma neopterin was normalized in all follow-up patients, indicative of a reduction in the adaptive immune activity that has been previously detected in active SARS-CoV-2 infection. Other systemic inflammatory biomarkers such as GlycA and the kynurenine/tryptophan ratio remained elevated in some, but not all, patients. Correlation analysis, principal component analysis (PCA), and orthogonal-partial least-squares discriminant analysis (O-PLS-DA) showed that the follow-up patients were, as a group, metabolically distinct from controls and partially comapped with the acute-phase patients. Significant systematic metabolic differences between asymptomatic and symptomatic follow-up patients were also observed for multiple metabolites. The overall metabolic variance of the symptomatic patients was significantly greater than that of nonsymptomatic patients for multiple parameters (χ2 p = 0.014). Thus, asymptomatic follow-up patients including those with post-acute COVID-19 Syndrome displayed a spectrum of multiple persistent biochemical pathophysiology, suggesting that the metabolic phenotyping approach may be deployed for multisystem functional assessment of individual post-acute COVID-19 patients.

Metarhizium spp., cosmopolitan insect-pathogenic fungi: mycological aspects.

Abstract: Publisher Summary The chapter focuses on mycological aspects of the genus Metarhizium . The genus includes several species, varieties within species, and individual isolates with broad ranges of physiological traits—including host range. The interactions of these fungi with their hosts, and the large literature on their use for pest control, largely define the scientific and popular concepts of Metarhizium spp. Fungi of the hyphomycete genus Metarhizium have been isolated from infected insects and soil. Although some isolates of these fungi have rather restricted host ranges, the group is better known for its ability to kill a wide spectrum of insects, including insects in at least seven orders. The common name for Metarhizium -induced disease is “green muscardine,” based on the encrustation of insect cadavers with green conidia. The rapid increase in research on Metarhizium , followed by sustained high scientific output, can be explained by several important worldwide attitude changes and the initiation of several promising Metarhizium -based pest-control and molecular-biology efforts.