The aim of this research is to reduce the number of defects caused by the hydrophobicity of silica aerogel (SA) in the interfacial transition zone formed by this solid aggregate and a liquid binder ...in an alternative construction composite (paste). A new technique for controlling compatibility issues has been developed by modifying the chemicals and physical properties involved, evaluating two surfactants that function as elements that increase adhesion strength. The characteristics of wettability and free surface energy are beneficial for macroscopic morphology, microscopic structure, porosity, pore size, and physisorption, and they influence the mechanical and thermal properties of the composites. The contact angle shows that the composites obtained with the smallest SA particle size modify the wettability of the composite, increasing the contact angle to 136°, thus approaching the limit of superhydrophobic surfaces. Conversely, the composites with the large SA particles sizes decrease the angle to 94°, approaching the hydrophilic limit. The copolymer (COP) is the most efficient surfactant, achieving high surface energies, sometimes doubling those of composites integrated with only SA. Microscopy images show the presence of additional compact and homogeneous composites, with few separations and cracks. Additionally, the porosity increases to a total pore volume of 0.3376 cm
3
/g, and the specimen has an average pore size of 26.576 nm and a surface area of 50.811 m
2
/g. The compounds modified with the copolymer A3100COP and A3110COP and those modified with A3100S and silane (S) achieve great efficiency, with a mechanical strength of 5.19 MPa and a thermal conductivity of 0.141 W/(m·K) after 28 days.
The analysis of fractal texture reflects a change in pixel intensity, and this might contain information about the structure of objects since a great change in intensity might usually indicate ...changes in the object. In the images of banana surfaces, the texture image can, to some extent, reflect changes and thus it can be used as an indicator of the last stage during the ripening process (over-ripening). In this experiment, bananas (
Musa cavendish) were stored during 10 days at 20
°C. Images of banana surfaces were recorded using a computational vision system. The over-ripening process of bananas was represented by an increment in the fractal value derived from texture fractal Fourier analysis. The result shows that fractal texture derived from the spectral Fourier analysis increased monotonically and it can be used as an indicator of the senescence process also called “senescent spotting” of the banana peel.
In May 2010, SCID was recommended to be added to the panel of genetic disorders in the national uniform newborn screening (NBS) program.1 SCID screening involves the measurement of T-cell receptor ...excision circles (TRECs), by-products of T-cell receptor rearrangement that reflect the robustness of T-cell production in the thymus; low blood levels of TRECs suggest profound T lymphopenia and are used to identify newborns for further evaluation. Hematopoietic stem cell transplant remains the only curative treatment, but the increased incidence and severity of graft-versus-host disease in association with pretransplant viral infections emphasize the importance of early diagnosis and intervention.6 In addition, the identification of 2 cases in California within a 6-month period and in patients of an ethnic background not usually associated with this disease suggest that MHC class II deficiency may not be as rare as previously considered.
Abstract
This study was designed to propose alternative therapeutic compounds to fight against bacterial pathogens. Thus, a library of nitrogen-based compounds bis(triazolyl)methane (1T–7T) and ...bis(pyrazolyl)methane (1P–11P) was synthesised following previously reported methodologies and their antibacterial activity was tested using the collection strains of
Staphylococcus aureus, Enterococcus faecalis
,
Escherichia coli,
and
Pseudomonas aeruginosa
. Moreover, the novel compound 2P was fully characterized by IR, UV–Vis and NMR spectroscopy. To evaluate antibacterial activity, minimal inhibitory concentrations (MICs), minimal bactericidal concentrations (MBCs), minimum biofilm inhibitory concentrations (MBICs), and minimum biofilm eradication concentrations (MBECs) assays were carried out at different concentrations (2–2000 µg/mL). The MTT assay and Resazurin viability assays were performed in both human liver carcinoma HepG2 and human colorectal adenocarcinoma Caco-2 cell lines at 48 h. Of all the synthesised compounds, 2P had an inhibitory effect on Gram-positive strains, especially against
S. aureus
. The MIC and MBC of 2P were 62.5 and 2000 µg/mL against
S. aureus
, and 250 and 2000 µg/mL against
E. faecalis
, respectively. However, these values were > 2000 µg/mL against
E. coli
and
P. aeruginosa
. In addition, the MBICs and MBECs of 2P against
S. aureus
were 125 and > 2000 µg/mL, respectively, whereas these values were > 2000 µg/mL against
E. faecalis
,
E. coli
, and
P. aeruginosa
. On the other hand, concentrations up to 250 µg/mL of 2P were non-toxic doses for eukaryotic cell cultures. Thus, according to the obtained results, the 2P nitrogen-based compound showed a promising anti-Gram-positive effect (especially against
S. aureus
) both on planktonic state and biofilm, at non-toxic concentrations.
► SAA2.2 folds into a kinetically favored octameric species that slowly converts to a hexamer at 4°C. ► The octamer is ∼10°C less stable than the hexamer, explaining the octamer to hexamer ...conversion. ► Data suggest that a dimeric/trimeric intermediate is the rate-limiting step in hexamer formation. ► SAA might be modulated in vivo to form different biologically distinct oligomeric species.
Serum amyloid A (SAA) is an inflammatory protein predominantly bound to high-density lipoprotein in plasma and presumed to play various biological and pathological roles. We previously found that the murine isoform SAA2.2 exists in aqueous solution as a marginally stable hexamer at 4–20°C, but becomes an intrinsically disordered protein at 37°C. Here we show that when urea-denatured SAA2.2 is dialyzed into buffer (pH 8.0, 4°C), it refolds mostly into an octameric species. The octamer transitions to the hexameric structure upon incubation from days to weeks at 4°C, depending on the SAA2.2 concentration. Thermal denaturation of the octamer and hexamer monitored by circular dichroism showed that the octamer is ∼10°C less stable, with a denaturation mid point of ∼22°C. Thus, SAA2.2 becomes kinetically trapped by refolding into a less stable, but more kinetically accessible octameric species. The ability of SAA2.2 to form different oligomeric species in vitro along with its marginal stability, suggest that the structure of SAA might be modulated in vivo to form different biologically relevant species.
is one of the species with the greatest clinical importance and greatest impact on public health. In fact, methicillin-resistant
(MRSA) is considered a pandemic pathogen, being essential to develop ...effective medicines and combat its rapid spread. This study aimed to foster the translation of clinical research outcomes based on metallodrugs into clinical practice for the treatment of MRSA. Bearing in mind the promising anti-Gram-positive effect of the heteroscorpionate ligand 1,1'-(2-(4-isopropylphenyl)ethane-1,1-diyl)bis(3,5-dimethyl-1H-pyrazole) (2P), we propose the coordination of this compound to platinum as a clinical strategy with the ultimate aim of overcoming resistance in the treatment of MRSA. Therefore, the novel metallodrug 2P-Pt were synthetized, fully characterized and its antibacterial effect against the planktonic and biofilm state of
evaluated. In this sense, three different strains of
were studied, one collection strain of
sensitive to methicillin and two clinical MRSA strains. To appraise the antibacterial activity, minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), minimum biofilm inhibitory concentration (MBIC), and minimum biofilm eradication concentration (MBEC) were determined. Moreover, successful outcomes on the development of biofilm in a wound-like medium were obtained. The mechanism of action for 2P-Pt was proposed by measuring the MIC and MBC with EDTA (cation mediated mechanism) and DMSO (exogenous oxidative stress mechanism). Moreover, to shed light on the plausible antistaphylococcal mechanism of this novel platinum agent, additional experiments using transmission electron microscopy were carried out. 2P-Pt inhibited the growth and eradicated the three strains evaluated in the planktonic state. Another point worth stressing is the inhibition in the growth of MRSA biofilm even in a wounded medium. The results of this work support this novel agent as a promising therapeutic alternative for preventing infections caused by MRSA.
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•T. sanguinea LSR01 and T. villosa LSR02 produce biofoams from beer bagasse.•Biofoam production has potential in the valorization of brewery waste.•The mechanical stability of ...biofoams improves as laccase production increases.•Biofoams have residual laccase activity after drying oven process.•Biofoams can be used as green catalysts in biooxidation reactions.
White rot fungi are promising organisms for the production of mycelial-based biofoams, providing a sustainable means of valorizing lignocellulosic wastes. This study explores the utilization of two indigenous fungal species, isolated from Argentina and belonging to the genera Trametes, for producing biofoams from brewery waste. The resulting biofoams exhibited an average density of 0.30 g cm−3, a Young’s modulus of approximately 1 MPa, and a compressive stress of around 19 MPa. Additionally, the variation of laccase activity throughout the biofoam production process was evaluated. Surprisingly, residual laccase activity was detected in the biofoams following oven drying at temperatures of 60, 80, and 100 °C. This detection highlights the untapped enzymatic potential of the biofoams and positions them as promising green catalysts for various biotechnological applications.
Nanotechnology is a developing field that has boomed in recent years due to the multiple qualities of nanoparticles (NPs), one of which is their antimicrobial capacity. We propose that NPs anchored ...with 2-(dimethylamino)ethyl methacrylate (DMAEMA) have antibacterial properties and could constitute an alternative tool in this field. To this end, the antimicrobial effects of three quaternised NPs anchored with DMAEMA were studied. These NPs were later copolymerized using different methylmethacrylate (MMA) concentrations to evaluate their role in the antibacterial activity shown by NPs. Clinical strains of
,
,
and
were used to assess antibacterial activity. The minimal inhibitory concentration (MIC) was determined at the different concentrations of NPs to appraise antibacterial activity. The cytotoxic effects of the NPs anchored with DMAEMA were determined in NIH
T
mouse fibroblast cultures by MTT assays. All the employed NPs were effective against the studied bacterial strains, although increasing concentrations of the MMA added during the synthesis process diminished these effects without altering toxicity in cell cultures. To conclude, more studies with other copolymers are necessary to improve the antibacterial effects of NPs anchored with DMAEMA.
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