Synthetic antibiofilm peptides de la Fuente-Núñez, César; Cardoso, Marlon Henrique; de Souza Cândido, Elizabete ...
Biochimica et biophysica acta,
05/2016, Letnik:
1858, Številka:
5
Journal Article
Recenzirano
Odprti dostop
Bacteria predominantly exist as multicellular aggregates known as biofilms that are associated with at least two thirds of all infections and exhibit increased adaptive resistance to conventional ...antibiotic therapies. Therefore, biofilms are major contributors to the global health problem of antibiotic resistance, and novel approaches to counter them are urgently needed. Small molecules of the innate immune system called host defense peptides (HDPs) have emerged as promising templates for the design of potent, broad-spectrum antibiofilm agents. Here, we review recent developments in the new field of synthetic antibiofilm peptides, including mechanistic insights, synergistic interactions with available antibiotics, and their potential as novel antimicrobials against persistent infections caused by biofilms. This article is part of a Special Issue entitled: Antimicrobial peptides edited by Karl Lohner and Kai Hilpert.
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•Bacteria often live in multicellular communities called biofilms that exhibit increased adaptive resistance to antibiotics.•Naturally occurring host defense peptides (HDPs) are excellent templates for engineering optimized synthetic peptides.•Anti-biofilm peptides have broad spectrum activity synergize with conventional antibiotics, and work in animal models.•Bio-inspired synthetic peptides have potential for human health applications and in biomaterials.
Background and Aims
Results from a recent study among 750 heroin users in three Mexico's northern border cities revealed an increase in white powder availability (also known as China white) and ...preference for this product among heroin users, as well as a general perception of increased overdose cases among this population. Here, we questioned whether those findings reflect an increased presence of heroin laced with fentanyl, which is associated with greater risks of overdose but that, until now, has not been described in Mexico.
Design
We tested fentanyl using highly sensitive test strips in syringe plungers, metal cookers and drug wrappings associated with heroin use.
Setting
Three injection sites in Tijuana, Baja California, México.
Participants
Eighty‐nine heroin users who interchanged paraphernalia for new syringes.
Measurements
We tested 59 residues of ‘pure’ white powder. The rest were white powder with black tar (n = 5) or white powder with crystal meth (n = 9), black tar with crystal meth (n = 1), black tar only (n = 13) and crystal meth only (n = 2).
Findings
Users believed that they consumed either white powder heroin, white powder heroin with crystal meth, white powder with black tar heroin or black tar heroin only. Analyses revealed that 93% (n = 55) of the ‘pure’ white powder samples had fentanyl. All (n = 9) the white powder samples mixed with crystal meth and 40% (n = 2) of the white powder with black tar were also laced with fentanyl.
Conclusions
In a sample of 89 heroin users in Mexico, most white powder heroin users were unknowingly exposed to fentanyl, with fentanyl detected in 93% of white powder samples.
The boron removal capacity from an aqueous solution using MgAlFe mixed oxides from layered double hydroxides (LDH) was studied. They were synthesized by the coprecipitation method at 70 °C and were ...characterized as potential filter materials. The Fe3+ analyzed by X-ray photoelectron spectroscopy and UV–visible diffuse reflectance showed their tetrahedral and octahedral coordination. Scanning electron microscopy micrographs and thermogravimetric and differential scanning calorimetry analysis evidenced the presence of clusters and particles aggregates and decreased dehydroxylation temperature when the iron content increased. Mixed oxides and boron solution in a ratio of 20:1 Mg/B were put in a batch reactor at different contact times. The borate removal process was due to the memory effect of the mixed oxides and superficial adsorption by electrostatic attraction. This fact is directly related to the specific surface area, Fe content, and surface charge. The maximum boron removals were achieved with the CS25 and CS50 samples with values higher than 85%.
Many authors have suggested that the vulnerability of montane biodiversity to climate change worldwide is significantly higher than in most other ecosystems. Despite the extensive variety of studies ...predicting severe impacts of climate change globally, few studies have empirically validated the predicted changes in distribution and population density. Here, we used 17 years (2000-2016) of standardised bird monitoring across latitudinal/elevational gradients in the rainforest of the Australian Wet Tropics World Heritage Area to assess changes in local abundance and elevational distribution. We used relative abundance in 1977 surveys across 114 sites ranging from 0-1500m above sea level and utilised a trend analysis approach (TRIM) to investigate elevational shifts in abundance of 42 species. The local abundance of most mid and high elevation species has declined at the lower edges of their distribution by >40% while lowland species increased by up to 190% into higher elevation areas. Upland-specialised species and regional endemics have undergone dramatic population declines of almost 50%. The "Outstanding Universal Value" of the Australian Wet Tropics World Heritage Area, one of the most irreplaceable biodiversity hotspots on Earth, is rapidly degrading. These observed impacts are likely to be similar in many tropical montane ecosystems globally.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Amine-functionalized anion-tethered ionic liquids (ILs) trihexyl(tetradecyl)phosphonium asparaginate P66614Asn, glutaminate P66614Gln, lysinate P66614Lys, methioninate P66614Met, prolinate P66614Pro, ...taurinate P66614Tau, and threoninate P66614Thr were synthesized and investigated as potential absorbents for CO2 capture from postcombustion flue gas. Their physical properties, including density, viscosity, glass transition temperature, and thermal decomposition temperature were determined. Furthermore, the CO2 absorption isotherms of P66614Lys, P66614Tau, P66614Pro, and P66614Met were measured using a volumetric method, and the results were modeled with two different Langmuir-type absorption models. The most important result of this study is that the viscosity of P66614Pro only increased by a factor of 2 when fully complexed with 1 bar of CO2 at room temperature. This is in stark contrast to the other chemically reacted ILs investigated here and all other amino acid-based ILs reported in the literature, which dramatically increase in viscosity, typically by 2 orders of magnitude, when complexed with CO2. The unique behavior of P66614Pro is likely due to its ring structure, which limits the number and availability of hydrogen atoms that can participate in a hydrogen bonding network. We found that water can be used to further reduce the viscosity of the CO2-complexed IL, while only slightly decreasing the CO2 capacity. Finally, from temperature-dependent isotherms, we estimate a heat of absorption of −63 kJ/mol of CO2 for the 1:1 reaction of CO2 with P66614Pro, when we use the two-reaction model.
Abstract
We employ the corrected Gaia Early Data Release 3 photometric data and spectroscopic data from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) DR7 to assemble a sample ...of approximately 0.25 million FGK dwarf photometric standard stars for the 12 J-PLUS filters using the stellar color regression (SCR) method. We then independently validate the J-PLUS DR3 photometry and uncover significant systematic errors: up to 15 mmag in the results from the stellar locus method and up to 10 mmag primarily caused by magnitude-, color-, and extinction-dependent errors of the Gaia XP spectra as revealed by the Gaia BP/RP (XP) synthetic photometry (XPSP) method. We have also further developed the XPSP method using the corrected Gaia XP spectra by B. Huang et al. and applied it to the J-PLUS DR3 photometry. This resulted in an agreement of 1–5 mmag with the SCR method and a twofold improvement in the J-PLUS zero-point precision. Finally, the zero-point calibration for around 91% of the tiles within the LAMOST observation footprint is determined through the SCR method, with the remaining approximately 9% of the tiles outside this footprint relying on the improved XPSP method. The recalibrated J-PLUS DR3 photometric data establish a solid data foundation for conducting research that depends on high-precision photometric calibration.
As tick-borne diseases are on the rise, an international effort resulted in the sequence and assembly of the first genome of a tick vector. This result promotes research on comparative, functional ...and evolutionary genomics and the study of tick-host-pathogen interactions to improve human, animal and ecosystem health on a global scale.
The design of the first weathering steels was purely empirical and focused on a small number of conventional alloying elements such as manganese, silicon, chromium, nickel, copper and phosphorus, ...mainly. The environmental conditions that promote the formation of protective rust layers: existence of wet/dry cycling, absence of very long wetness times, atmospheres without a marine component, etc., were identified by trial and error. This paper makes a bibliographic review of the abundant literature that has been published on the atmospheric corrosion of weathering steels, setting out in chronological order the advances made in the scientific knowledge of important matters such as: atmospheric corrosion mechanisms of weathering steel, formation of protective rust layers, and the role played by alloying elements. The work ends with an overview of the scientific design of new weathering steels, placing special emphasis on the new compositions developed for application in marine atmospheres.
The ESA-JAXA BepiColombo mission will provide simultaneous measurements from two spacecraft, offering an unprecedented opportunity to investigate magnetospheric and exospheric dynamics at Mercury as ...well as their interactions with the solar wind, radiation, and interplanetary dust. Many scientific instruments onboard the two spacecraft will be completely, or partially devoted to study the near-space environment of Mercury as well as the complex processes that govern it. Many issues remain unsolved even after the MES-SENGER mission that ended in 2015. The specific orbits of the two spacecraft, MPO and Mio, and the comprehensive scientific payload allow a wider range of scientific questions to be addressed than those that could be achieved by the individual instruments acting alone, or by previous missions. These joint observations are of key importance because many phenomena in Mercury’s environment are highly temporally and spatially variable. Examples of possible coordinated observations are described in this article, analysing the required geometrical conditions, pointing, resolutions and operation timing of different BepiColombo instruments sensors.
Bacterial biofilms are responsible for most clinical infections and show increased antimicrobial resistance. In this study, molecularly imprinted polymers (MIPs) were developed to specifically ...capture prototypical quorum sensing autoinducers i.e., N-(3-oxododecanoyl)-l-homoserine lactone (3-oxo-C12AHL), interrupt quorum sensing, and subsequently inhibit biofilm formation of Pseudomonas aeruginosa, an important human nosocomial pathogen. The synthesis of MIPs was optimized by considering the amount and type of the functional monomers itaconic acid (IA) and 2-hydroxyethyl methacrylate (HEMA). IA-based MIPs showed high adsorption affinity toward 3-oxo-C12AHL with an imprinting factor of 1.68. Compared to IA-based MIPs, the adsorption capacity of HEMA-based MIPs was improved fivefold. HEMA-based MIPs significantly reduced biofilm formation (by ∼65%), whereas biofilm suppression by IA-based MIPs was neutralized because of increased bacterial attachment. The developed MIPs represent promising alternative biofilm intervention agents that can be applied to surfaces relevant to clinical settings and food processing equipment.
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