Colloidal nanoparticles (NPs) have become versatile building blocks in a wide variety of fields. Here, we discuss the state-of-the-art, current hot topics, and future directions based on the ...following aspects: narrow size-distribution NPs can exhibit protein-like properties; monodispersity of NPs is not always required; assembled NPs can exhibit collective behavior; NPs can be assembled one by one; there is more to be connected with NPs; NPs can be designed to be smart; surface-modified NPs can directly reach the cytosols of living cells.
Nurses in primary health care (PHC) have multiple responsibilities but must often work with limited resources. The study's aim was to estimate burnout levels among PHC nurses. A Quantitative, ...observational, cross-sectional, multicentre study of 338 nurses working in PHC in the Andalusian Public Health Service (Spain) is presented. A total of 40.24% of the nurses studied had high levels of burnout. The dimensions of emotional exhaustion and depersonalisation were significantly associated with anxiety, depression, neuroticism, on-call duty and seniority-profession and inversely related to agreeableness. In addition, depersonalisation was significantly associated with gender, and emotional exhaustion correlated inversely with age. Personal achievement was inversely associated with anxiety and depression and positively correlated with agreeableness, extraversion and responsibility. There is a high prevalence of burnout among nurses in PHC. Those most likely to suffer burnout syndrome are relatively young, suffer from anxiety and depression and present high scores for neuroticism and low ones for agreeableness, responsibility and extraversion.
Biofilm-related infections account for at least 65% of all human infections, but there are no available antimicrobials that specifically target biofilms. Their elimination by available treatments is ...inefficient since biofilm cells are between 10- and 1,000-fold more resistant to conventional antibiotics than planktonic cells. Here we describe the synergistic interactions, with different classes of antibiotics, of a recently characterized antibiofilm peptide, 1018, to potently prevent and eradicate bacterial biofilms formed by multidrug-resistant ESKAPE (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens. Combinations of peptide 1018 and the antibiotic ceftazidime, ciprofloxacin, imipenem, or tobramycin were synergistic in 50% of assessments and decreased by 2- to 64-fold the concentration of antibiotic required to treat biofilms formed by Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, Salmonella enterica, and methicillin-resistant Staphylococcus aureus. Furthermore, in flow cell biofilm studies, combinations of low, subinhibitory levels of the peptide (0.8 μg/ml) and ciprofloxacin (40 ng/ml) decreased dispersal and triggered cell death in mature P. aeruginosa biofilms. In addition, short-term treatments with the peptide in combination with ciprofloxacin prevented biofilm formation and reduced P. aeruginosa PA14 preexisting biofilms. PCR studies indicated that the peptide suppressed the expression of various antibiotic targets in biofilm cells. Thus, treatment with the peptide represents a novel strategy to potentiate antibiotic activity against biofilms formed by multidrug-resistant pathogens.
Bacteria form multicellular communities known as biofilms that cause two thirds of all infections and demonstrate a 10 to 1000 fold increase in adaptive resistance to conventional antibiotics. ...Currently, there are no approved drugs that specifically target bacterial biofilms. Here we identified a potent anti-biofilm peptide 1018 that worked by blocking (p)ppGpp, an important signal in biofilm development. At concentrations that did not affect planktonic growth, peptide treatment completely prevented biofilm formation and led to the eradication of mature biofilms in representative strains of both Gram-negative and Gram-positive bacterial pathogens including Pseudomonas aeruginosa, Escherichia coli, Acinetobacter baumannii, Klebsiella pneumoniae, methicillin resistant Staphylococcus aureus, Salmonella Typhimurium and Burkholderia cenocepacia. Low levels of the peptide led to biofilm dispersal, while higher doses triggered biofilm cell death. We hypothesized that the peptide acted to inhibit a common stress response in target species, and that the stringent response, mediating (p)ppGpp synthesis through the enzymes RelA and SpoT, was targeted. Consistent with this, increasing (p)ppGpp synthesis by addition of serine hydroxamate or over-expression of relA led to reduced susceptibility to the peptide. Furthermore, relA and spoT mutations blocking production of (p)ppGpp replicated the effects of the peptide, leading to a reduction of biofilm formation in the four tested target species. Also, eliminating (p)ppGpp expression after two days of biofilm growth by removal of arabinose from a strain expressing relA behind an arabinose-inducible promoter, reciprocated the effect of peptide added at the same time, leading to loss of biofilm. NMR and chromatography studies showed that the peptide acted on cells to cause degradation of (p)ppGpp within 30 minutes, and in vitro directly interacted with ppGpp. We thus propose that 1018 targets (p)ppGpp and marks it for degradation in cells. Targeting (p)ppGpp represents a new approach against biofilm-related drug resistance.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
The purpose of this work is to fabricate self-assembled microstructures by the sol-gel method and study the morphological, structural and compositional dependence of -Fe
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nanoparticles embedded ...in silica when glycerol (GLY) and cetyl-trimethylammonium bromide (CTAB) are added as steric agents simultaneously. The combined action of a polyalcohol and a surfactant significantly modifies the morphology of the sample giving rise to a different microstructure in each of the studied cases (1, 3 and 7 days of magnetic stirring time). This is due to the fact that the addition of these two compounds leads to a considerable increase in gelation time as GLY can interact with the alkoxide group on the surface of the iron oxide precursor micelle and/or be incorporated into the hydrophilic chains of CTAB. This last effect causes the iron oxide precursor micelles to be interconnected forming aggregates whose size and structure depend on the magnetic stirring time of the sol-gel synthetic route. In this paper, crystalline structure, composition, purity and morphology of the sol-gel coatings densified at 960 °C are examined. Emphasis is placed on the nominal percentage of the different iron oxides found in the samples and on the morphological and structural differences. This work implies the possibility of patterning -Fe
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nanoparticles in coatings and controlling their purity by an easy one-pot sol-gel method.
Sol-gel synthesis of self-assembled iron oxide precursor micelles.
Europium-doped calcium hydroxyapatite and fluoroapatite nanophosphors functionalized with poly(acrylic acid) (PAA) have been synthesized through a one-pot microwave-assisted hydrothermal method from ...aqueous basic solutions containing calcium nitrate, sodium phosphate monobasic, and PAA, as well as sodium fluoride in the case of the fluoroapatite particles. In both cases a spindlelike morphology was obtained, resulting from an aggregation process of smaller subunits which also gave rise to high specific surface area. The size of the nanospindles was 191 (32) × 40 (5) nm for calcium hydroxyapatite and 152 (24) × 38 (6) nm for calcium fluoroapatite. The luminescent nanoparticles showed the typical red luminescence of Eu3+, which was more efficient for the fluoroapatite particles than for the hydroxyapatite. This is attributed to the presence of OH– quenchers in the latter. The nanophosphors showed negligible toxicity for Vero cells. Both PAA-functionalized nanophosphors showed a very high (up to at least 1 week) colloidal stability in 2-(N-morpholino)ethanesulfonic acid (MES) at pH 6.5, which is a commonly used buffer for physiological pH. All these features make both kinds of apatite-based nanoparticles promising tools for biomedical applications, such as luminescent biolabels and tracking devices in drug delivery systems.
Highlights • Biofilms may have evolved as an adaptive response to environmental stresses. • Biofilm formation is a complex process involving sophisticated regulatory networks. • Biofilms are highly ...resistant to diverse antibiotics. • Resistance is adaptive and mediated through a plethora of molecular mechanisms. • Potential new therapeutics that specifically target biofilms are under development.
Objective: Hodgkin and non-Hodgkin lymphoma patients are at high risk of experiencing anxiety because the clinical processes and therapies they undergo produce strong adverse effects. In this review ...we discuss the prevalence of anxiety among these patients and examine the methods used for data collection, intervention frequency, types of instruments used to recognize anxiety, and data collection purposes, both in Hodgkin and non-Hodgkin lymphoma survivors and patients being treated or diagnosed with these diseases. Methods: This systematic review and meta-analysis of the literature was carried out using the following sources: PubMed, Scopus, LILACS, and PsycINFO. Results: The meta-analysis sample was n = 2,138 and the overall prevalence of anxiety was 19% (95% CI 12%, 25%). According to the Egger test, there were no publication biases and no studies were eliminated after the sensitivity analysis. The I2 for the heterogeneity analysis was 92.6%. Conclusions: Hodgkin and non-Hodgkin lymphoma patients are vulnerable to suffering anxiety. It is important to focus on the psychological effect of anxiety during remission or current cancer treatments because they can affect patient outcomes.
Extensive information on the atmospheric corrosion of weathering steel has been published in the scientific literature. The contribution of the present work is to provide a bibliographic review of ...the reported information, which mostly concerns the weathering steel ASTM A-242. This review addresses issues such as rust layer stabilisation times, steady-state steel corrosion rates, and situations where the use of unpainted weathering steel is feasible. It also analyses the effect of exposure conditions. Finally it approaches the important matter of predicting the long-term behaviour of weathering steel reviewing the different prediction models published in the literature.
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