Filamentous fungi constitute a large group of eukaryotic microorganisms that grow by forming simple tube-like hyphae that are capable of differentiating into more-complex morphological structures and ...distinct cell types. Hyphae form filamentous networks by extending at their tips while branching in subapical regions. Rapid tip elongation requires massive membrane insertion and extension of the rigid chitin-containing cell wall. This process is sustained by a continuous flow of secretory vesicles that depends on the coordinated action of the microtubule and actin cytoskeletons and the corresponding motors and associated proteins. Vesicles transport cell wall-synthesizing enzymes and accumulate in a special structure, the Spitzenkörper, before traveling further and fusing with the tip membrane. The place of vesicle fusion and growth direction are enabled and defined by the position of the Spitzenkörper, the so-called cell end markers, and other proteins involved in the exocytic process. Also important for tip extension is membrane recycling by endocytosis via early endosomes, which function as multipurpose transport vehicles for mRNA, septins, ribosomes, and peroxisomes. Cell integrity, hyphal branching, and morphogenesis are all processes that are largely dependent on vesicle and cytoskeleton dynamics. When hyphae differentiate structures for asexual or sexual reproduction or to mediate interspecies interactions, the hyphal basic cellular machinery may be reprogrammed through the synthesis of new proteins and/or the modification of protein activity. Although some transcriptional networks involved in such reprogramming of hyphae are well studied in several model filamentous fungi, clear connections between these networks and known determinants of hyphal morphogenesis are yet to be established.
Ultrasound-assisted extraction is a common technique for the extraction of organic contaminants from solid samples due to its ease of application to a variety of matrices and the wide range of ...solvents that can be used. In recent years, many methods have combined sonication with microextraction techniques for liquid samples. Among the improvements in extraction techniques, there is an increasing interest in reducing the use of traditional organic solvents or replacing them with other less toxic solvents, such as ionic liquids due to the negligible vapour pressure of these solvents. However, these solvents are not fully green due to poor biodegradability and some toxicity to aquatic life. As a result of the growing interest in the so-called “Green Chemistry”, the use of more environmentally friendly solvents, such as deep eutectic solvents, or novel sorbents, such as magnetic nanoparticles, has been observed for the extraction of organic contaminants. This review provides an overview of the new applications of ultrasound-assisted extraction for the determination of organic contaminants, with special emphasis on the methods that implement the principles of Green Analytical Chemistry to reduce the environmental impact. In this article, the ultrasound-assisted extraction methods proposed in the last five years (2018–2022) are reviewed to update our previous review.
•Overview of new applications of ultrasound assisted extraction from 2018 to 2022.•Ultrasound-assisted extraction methods for organic contaminants are discussed.•Microextraction methods for liquid samples are summarized.•Application of new sorbents and green solvents is discussed.
Ultrasound-assisted extraction is an efficient environmental friendly technique, since the solvent volume required in sample preparation is reduced and the extraction time is shortened in comparison ...to classical extraction procedures. Ultrasound radiation has been primarily applied to the extraction of analytes from solid samples. However, an important increase in the application of ultrasounds in the extraction of liquid samples has been observed lately, coupled to new microextraction techniques. Several improvements have been applied to these techniques, such as the use of ionic liquids or surfactants, as green solvents. This review discusses the application of different ultrasound-assisted techniques in the analysis of frequently occurring organic contaminants in food and environmental samples, mainly focused on the works published in the last five years.
•Ultrasound-assisted extraction of organic contaminants is discussed.•Microextraction techniques for solid and liquid samples are reviewed.•Application of new sorbents, ionic liquids and supramolecular solvents is discussed.
The availability and persistence of various antibiotics in soil and soil amended with composted poultry manure were investigated through laboratory incubation assays. Six veterinary antibiotics (one ...fluoroquinolone, two tetracyclines, two sulfonamides and one lincosamide) and one active metabolite (ciprofloxacin) were studied. The incubation assays were conducted at a controlled temperature of 25 °C with different water regimes, such as constant moisture content (80% of water holding capacity) and drying-rewetting cycles. The studied antibiotics were determined in soil and soil aqueous phase samples by LC-MS/MS using internal standards. The results indicated that the highest levels found in the soil aqueous phase were for sulfamethoxazole, followed by sulfamethazine and lincomycin, being very low the levels of chlortetracycline, doxycycline, ciprofloxacin and enrofloxacin (≤1.8%). A positive correlation was observed between the antibiotic concentrations and the content of the dissolved organic carbon in soil aqueous phase with the incubation time. An increase in the apparent sorption coefficients of these antibiotics, except chlortetracycline and lincomycin, was observed when the soil was amended with composted manure. Except for fluoroquinolones, with remaining residues around 70% after 90 days of incubation, a fast dissipation of antibiotics was observed during the assay, with half-lives ranging from 8 to 27 days. These values increased between 6% and 53% in manure amended soil; nevertheless, half-lives remained short (9 days and 27 days for lincomycin and sulfamethazine, respectively). Similar results were obtained with soil under drying-rewetting cycles showing somewhat lower values in soil aqueous phase and slightly shorter half-lives in some cases. The results obtained pointed out that the route of entry of antibiotics into the soil, through recycled water or manure, may have an important effect on their behavior, particularly regarding their availability in soil.
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•Sulfonamides and lincomycin showed the highest levels in soil solution.•A correlation was observed between antibiotic availability, incubation time and DOC.•Except for fluoroquinolones, a fast dissipation of antibiotics in soil occurred.•Entry route affects the fate of antibiotics in soil.
Aims and objectives
To examine registered nurses' self‐evaluation of their competence in mentoring nursing students in clinical practice.
Background
Clinical mentors have significant roles and ...responsibility for nursing students' clinical learning. Moreover, the mentors' role is becoming increasingly important internationally, as the role of nurse teachers in mentoring students in clinical practice has declined. However, in most EU countries there are no specific educational requirements for clinical mentors, although they need targeted education to increase their competence in mentoring nursing students.
Design
The systematic review of quantitative studies was designed according to guidelines of the Centre for Reviews and Dissemination and PRISMA protocol.
Methods
Studies published during 2000–2019 that met inclusion criteria formulated in PiCOS format were systematically reviewed by three independent reviewers. CINAHL (Ebsco), PubMed (MEDLINE), Scopus, ERIC and Medic databases were used to retrieve the studies. Three independent reviewers conducted the systematic review process. The studies were tabulated, thematically compared and narratively reported.
Results
In total, 16 peer‐reviewed studies met the inclusion criteria. The studies identified various dimensions of mentors´ competence and associated environmental factors. Generally, participating mentors rated competences related to the clinical environment, mentoring, supporting students' learning processes and relevant personal characteristics fairly high. They also rated organisational practices in their workplaces, resources in the clinical environment and their mentor–student and mentor–stakeholder pedagogical practices, as respectable or satisfactory.
Conclusion
The results indicate considerable scope for improving mentors' competence, particularly through enhancing organisational mentoring practices and relevant resources in clinical environments.
Relevance for clinical practice
Pedagogical practices of mentors in relations with both students and stakeholders should be enhanced to improve future nurses' learning. This systematic review addresses a gap in knowledge of mentors' self‐evaluated competence that could assist the formulation of effective educational programmes for mentors internationally and improving clinical environments.
Wine, and particularly red wine, is a beverage with a great chemical complexity that is in continuous evolution. Chemically, wine is a hydroalcoholic solution (~78% water) that comprises a wide ...variety of chemical components, including aldehydes, esters, ketones, lipids, minerals, organic acids, phenolics, soluble proteins, sugars and vitamins. Flavonoids constitute a major group of polyphenolic compounds which are directly associated with the organoleptic and health-promoting properties of red wine. However, due to the insufficient epidemiological and in vivo evidences on this subject, the presence of a high number of variables such as human age, metabolism, the presence of alcohol, the complex wine chemistry, and the wide array of in vivo biological effects of these compounds suggest that only cautious conclusions may be drawn from studies focusing on the direct effect of wine and any specific health issue. Nevertheless, there are several reports on the health protective properties of wine phenolics for several diseases such as cardiovascular diseases, some cancers, obesity, neurodegenerative diseases, diabetes, allergies and osteoporosis. The different interactions that wine flavonoids may have with key biological targets are crucial for some of these health-promoting effects. The interaction between some wine flavonoids and some specific enzymes are one example. The way wine flavonoids may be absorbed and metabolized could interfere with their bioavailability and therefore in their health-promoting effect. Hence, some reports have focused on flavonoids absorption, metabolism, microbiota effect and overall on flavonoids bioavailability. This review summarizes some of these major issues which are directly related to the potential health-promoting effects of wine flavonoids. Reports related to flavonoids and health highlight some relevant scientific information. However, there is still a gap between the knowledge of wine flavonoids bioavailability and their health-promoting effects. More in vivo results as well as studies focused on flavonoid metabolites are still required. Moreover, it is also necessary to better understand how biological interactions (with microbiota and cells, enzymes or general biological systems) could interfere with flavonoid bioavailability.
Background: Diabetes is related with oxidative stress caused by free radicals and glycation of the proteins. Objectives: This study aimed to isolate a polysaccharide (PLY) from Cucurbita argyrosperma ...seeds and determine their antioxidant and antiglycation effects. Materials and Methods: The PLY fraction was isolated by hot water extraction and purified by ion-exchange chromatography (A103S). La antioxidant capacities were evaluated by using lipid peroxidation, superoxide dismutase, glutathione peroxidase (GSH-Px), catalase, and malondialdehyde activities, and intracellular reactive oxygen species (ROS) with stimulation H2O2 in pancreatic β INS-1 cells. In addition, scavenging activities of PLY were estimated in 2,2 diphenyl-1-picrylhydrazyl radical, 2,2′-Azino-bis (3-ethylbenzothiazoline-6-sulfonic acid, β-carotene-linoleic acid, chelating activity, ferric reducing power, hydroxyl radical, nitric oxide radical, and superoxide anion radical assays. Therefore, the protective effect of PLY on reducing sugar-induced bovine serum albumin glycation was examined. Results: PLY consisted of mannose, galactose, and glucose in the molar ratio of 1.12:6.12:5.60 with an average molecular weight of 102326 Da. PLY had a pronounced radical scavenging potential as well as total antioxidant effect and prevented the cells ROS generation and increased the level of antioxidant enzymes. PLY inhibited the formation of carboxymethyllysine and fructosamine, prevented protein oxidation increasing the level of thiol, and decreasing protein carbonyl level, interacts with reactive dicarbonyl compounds (methylglyoxal), and decreased amyloid cross β-structure level. Conclusion: These results indicate that PLY enhanced antioxidant capacity and prevented oxidative stress and AGEs progression in its different stages. consequently, had promising effects on diabetes and associated disorders.
The aim of the present study was to evaluated hemoglobin A1c (HbA1c), the hemoglobin glycation index (HGI), and triglyceride and glucose (TG) index as predictive indicators for low feed intake in ...lactating sows due to glucose intolerance. Cactus (Opuntia ficus-indica) was included in sow diets as a modulating factor of glucose. Thirty-six sows were separated into three groups (Gs). Although the three groups received a conventional diet during gestation and lactation, 2.0 kg per sow per day of steam-cooked cactus (G1) and fresh cactus (G2) were added to the lactation diet as a glycemic modulating factor, with G3 serving as the control group. Glycemia was assessed via glucometer (blood glucose concentrations), HbA1c and HGI. For each indicator of glycemia the triglycerides and glucose (TG) index was evaluated. The highest blood glucose concentration was observed on day 3 of lactation (88.2 mg/dL). The average glycemic concentrations obtained from HbA1c on farrowing day (61.6 mg/dL) and day 21 of lactation (65.6 mg/dL) were lower (p<0.05) than those measured by a glucometer on the same days (71.8 and 77.7 mg/dL for farrowing day and day 21 of lactation, respectively). At farrowing, the TG index obtained from the HGI indicated that 83.0% of sows were glucose intolerant, compared to 100% according to the TG index obtained from a glucometer. At weaning, 50% of G2 did not show glucose intolerance when the TG index was calculated using the HGI, compared to 54% when it was calculated with blood glucose concentrations measured by a glucometer. All G3 sows presented glucose intolerance, regardless of the test used. The HbA1c, HGI, and TG index tests are viable alternatives to predict low feed intake due to glucose intolerance in lactating sows.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Impaired adipose tissue (AT) lipid handling and inflammation is associated with obesity-related metabolic diseases. Circulating lipopolysaccharides (LPSs) from gut microbiota (metabolic endotoxemia), ...proposed as a triggering factor for the low-grade inflammation in obesity, might also be responsible for AT dysfunction. Nevertheless, this hypothesis has not been explored in human obesity. To analyze the relationship between metabolic endotoxemia and AT markers for lipogenesis, lipid handling, and inflammation in human obesity, 33 patients with obesity scheduled for surgery were recruited and classified according to their LPS levels. Visceral and subcutaneous AT gene and protein expression were analyzed and adipocyte and AT in vitro assays performed. Subjects with obesity with a high degree of metabolic endotoxemia had lower expression of key genes for AT function and lipogenesis ( SREBP1, FABP4, FASN, and LEP) but higher expression of inflammatory genes in visceral and subcutaneous AT than subjects with low LPS levels. In vitro experiments corroborated that LPS are responsible for adipocyte and AT inflammation and downregulation of PPARG, SCD, FABP4, and LEP expression and LEP secretion. Thus, metabolic endotoxemia influences AT physiology in human obesity by decreasing the expression of factors involved in AT lipid handling and function as well as by increasing inflammation.
Bisphenol analogues are compounds extensively used which have been potentially linked to adverse health effects. Nevertheless, few studies reported the analysis of compounds, other than bisphenol A, ...in environmental solid samples and none in soil samples. In this study, a rapid and sensitive analytical method is presented for the simultaneous determination of 13 bisphenols in soil samples. The method combines ultrasonic-assisted extraction of samples placed in small columns and GC-MS/MS analysis. Manual and on-line derivatizations were compared and results showed that significant higher chromatographic responses were achieved with on-line derivatization. Different parameters such as the quantity of derivatization agent, the extraction solvent, or the extraction time were assayed. The detection limits for all target bisphenols ranged from 0.04 to 0.27 ng g
−1
, for BPC and BPA, respectively. Analysis of spiked soil samples gave satisfactory recovery results, from 70 to 111%, for all the compounds. Finally, the validated method was applied to soil samples from several Spanish areas, and 3 of the 13 target bisphenols (BPAF, BPF, and BPA) were detected, although only BPF and BPA could be quantified with levels up to 127 ng g
−1
.
Graphical abstract
Schematic diagram of the developed method for the determination of bisphenol analogues
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