A NiCo2O4 bimetallic electro-catalyst was synthesized on three-dimensional graphene (3D graphene) for the non-enzymatic detection of urea. The structural and morphological properties of the ...NiCo2O4/3D graphene nanocomposite were characterized by X-ray diffraction, Raman spectroscopy, and scanning electron microscopy. The NiCo2O4/3D graphene was deposited on an indium tin oxide (ITO) glass to fabricate a highly sensitive urea sensor. The electrochemical properties of the prepared electrode were studied by cyclic voltammetry. A high sensitivity of 166μAmM−1cm−2 was obtained for the NiCo2O4/3D graphene/ITO sensor. The sensor exhibited a linear range of 0.06–0.30mM (R2=0.998) and a fast response time of approximately 1.0s with a detection limit of 5.0µM. Additionally, the sensor exhibited high stability with a sensitivity decrease of only 5.5% after four months of storage in ambient conditions. The urea sensor demonstrates feasibility for urea analysis in urine samples.
•NiCo2O4 decorated 3D graphene has been used to fabricate a urea sensor.•NiCo2O4 nanoparticles were deposited by hydroxide decomposition.•The sensor exhibited ultra-high sensitivity with a low detection limit.•The sensor showed the feasibility of urea analysis in urine sample.
Excessive antimicrobial usage and deficiencies in hygiene in meat production systems may result in undesirable human health hazards, such as the presence of antimicrobial drug residues and ...non-typhoidal Salmonella (NTS), including antimicrobial resistant (AMR) NTS. Recently, Vietnam has witnessed the emergence of integrated intensive animal production systems, coexisting with more traditional, locally-sourced wet markets. To date no systematic studies have been carried out to compare health hazards in beef, pork and chicken in different production systems. We aimed to: (1) estimate the prevalence of antimicrobial residues in beef, pork and chicken meat; (2) investigate the prevalence and levels of NTS contamination; and (3) investigate serovar distribution and AMR against critically important antimicrobials by animal species and type of retail (wet market vs. supermarket) in Vietnam. Fresh pork, beef and chicken meat samples (N=357) sourced from wet markets and supermarkets in Ho Chi Minh City (HCMC), Hanoi and Dong Thap were screened for antimicrobial residues by PremiTest, and were further investigated by Charm II. Samples from HCMC (N=113) were cultured using ISO 6579:2002/Amd 1:2007. NTS bacteria were quantified using a minimum probable number (MPN) technique. NTS isolates were assigned to serovar by Multilocus Sequence Typing (MLST), and were investigated for their phenotypic susceptibility against 32 antimicrobials. A total of 26 (7.3%) samples tested positive by PremiTest (9.5% beef, 4.1% pork and 8.4% chicken meat). Sulfonamides, tetracyclines and macrolides were detected by Charm in 3.1%, 2.8% and 2.0% samples, respectively. Overall, meat samples from wet markets had a higher prevalence of residues than those from supermarkets (9.6% vs. 2.6%) (p=0.016). NTS were isolated from 68.4% samples from HCMC. Chicken samples from wet markets had by far the highest NTS counts (median 3.2 logMPN/g). NTS isolates displayed high levels of resistance against quinolones (52.2%) and β-lactams (49.6%), but low levels against 3rd generation cephalosporins (4.4%) and aminoglycosides (0.8%). The highest adjusted prevalence of multidrug resistance (MDR) corresponded to isolates from chicken meat and pork (OR 8.3 and 1.8, respectively) (baseline=beef). S. Kentucky was the most common serovar identified (11 from chicken, 1 from beef) and 91.7% isolates was MDR. 11/12 isolates corresponded to ST198, a worldwide-disseminated multi-resistant NTS clone. We recommend stepping up policy measures to promote responsible antimicrobial use in animal production, as well as awareness about withdrawal periods to limit the hazard of residues in animal products, and improving slaughtering/hygiene procedures to limit cross-contamination with NTS, particularly in poultry wet markets.
•Antimicrobial residues were found in 7.3% meat samples (9.6% in meat from wet markets and 2.6% in meat from supermarkets).•Over two thirds (68.4%) of meat samples were contaminated with non-typhoidal Salmonella; 52.2% of isolates were multidrug resistant.•Chicken meat from wet markets had the highest loads of contamination with non-typhoidal Salmonella (median 3.2logMPN/g in positive samples).•Multidrug resistance was highest in Salmonella from chicken meat, and lowest in beef; the type of retail was not linked to increased resistance.•The most commonly identified serovar was multidrug resistant Salmonella Kentucky ST198, with high levels resistance against β-lactams and quinolones.
A 90‐day feeding experiment was conducted in order to test spent brewer's yeast as a replacement for fishmeal in diets for giant freshwater prawn (Macrobrachium rosenbergii) reared in either a ...recirculating aquaculture system (RAS) or a biofloc system. Triplicate groups, each of 20 prawn (6.7 ± 0.03 g), were randomly assigned to 24 identical tanks. Twelve tanks were connected to the RAS, and the other 12 tanks were connected to the biofloc system which were initially supplemented with Bacillus subtilis, molasses and blood meal to achieve a C:N ratio of 20:1. Four iso‐nitrogenous (350 g/kg) and iso‐energetic (19 MJ/kg) diets where 0%, 20%, 40% and 60% of fishmeal protein was replaced by spent brewer's yeast. Neither growth nor survival was affected (p > 0.05) by increasing levels of brewer's yeast. The exception, being fish given 60% replacement with brewer's yeast, reared in biofloc, which displayed a higher (p < 0.05) growth than fish given 40% replacement, reared in clear water. The feed conversion ratio of prawn reared in the biofloc environment was lower than in the clear water. We concluded that spent brewer's yeast represents a possible 60% substitute for fishmeal in giant freshwater prawn diets, especially for prawn reared in a biofloc environment.
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Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
A highly sensitive non-enzymatic urea sensor was fabricated using nickel oxide deposited on a cellulose/carbon nanotube composite.
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•NiO nano particles were impregnated onto ...cellulose/CNT composite for the electro-oxidation of urea.•The simply prepared NiO/Cellulose/CNT electrode exhibited remarkably high sensitivity.•The sensor showed a high stability and feasibility for urea analysis in urine sample.
A highly sensitive non-enzymatic urea sensor was fabricated using nickel oxide deposited on a cellulose/carbon nanotube (CNT) composite. The structure and morphological properties of the NiO/cellulose/CNT composite were investigated using X-ray diffraction and scanning electron microscopy. A thin film of the NiO/cellulose/CNT composite was coated on an indium tin oxide glass to fabricate an amperometric urea sensor. The composition of the modified electrode and detection conditions (i.e., pH and temperature) were optimized. The prepared electrode exhibited an excellent sensitivity of 371μAmM−1cm−2 with a fast response time of 4s. The electrode also showed high stability with only a 3.6% decrease in its sensitivity after storage for two months under ambient conditions. In addition, the feasibility for urea analysis in urine samples was demonstrated.
Development and validation of large animal models of Pseudomonas aeruginosa ventilator-associated pneumonia are needed for testing new drug candidates in a manner that mimics how they will be used ...clinically. We developed a new model in which rabbits were ventilated with low tidal volume and challenged with P. aeruginosa to recapitulate hallmark clinical features of acute respiratory distress syndrome (ARDS): acute lung injury and inflammation, progressive decrease in arterial oxygen partial pressure to fractional inspired oxygen PaO
:FiO
, leukopenia, neutropenia, thrombocytopenia, hyperlactatemia, severe hypotension, bacterial dissemination from lung to other organs, multiorgan dysfunction, and ultimately death. We evaluated the predictive power of this rabbit model for antibiotic efficacy testing by determining whether a humanized dosing regimen of meropenem, a potent antipseudomonal β-lactam antibiotic, when administered with or without intensive care unit (ICU)-supportive care (fluid challenge and norepinephrine), could halt or reverse natural disease progression. Our humanized meropenem dosing regimen produced a plasma concentration-time profile in the rabbit model similar to those reported in patients with ventilator-associated bacterial pneumonia. In this rabbit model, treatment with humanized meropenem and ICU-supportive care achieved the highest level of survival, halted the worsening of ARDS biomarkers, and reversed lethal hypotension, although treatment with humanized meropenem alone also conferred some protection compared to treatment with placebo (saline) alone or placebo plus ICU-supportive care. In conclusion, this rabbit model could help predict whether an antibiotic will be efficacious for the treatment of human ventilator-associated pneumonia.
Regenerable, high‐efficiency salt sorption materials are highly desirable for water treatment. Here, a thermoresponsive, amphoteric metal–organic framework (MOF) material is reported that can adsorb ...multiple salts from saline water at room temperature and effectively release the adsorbed salts into water at elevated temperature (e.g., 80 °C). The amphoteric MOF, integrated with both cation‐binding carboxylic groups and anion‐binding tertiary amine groups, is synthesized by introducing a polymer with tertiary amine groups into the cavities of a water‐stable MOF such as MIL‐121 with carboxylic groups inside its frameworks. The amphoterized MIL‐121 exhibits excellent salt adsorption properties, showing stable adsorption–desorption cycling performances and high LiCl, NaCl, MgCl2, and CaCl2 adsorption capacities of 0.56, 0.92, 0.25, and 0.39 mmol g−1, respectively. This work provides a novel, effective strategy for synthesizing new‐generation, environmental‐friendly, and responsive salt adsorption materials for efficient water desalination and purification.
A thermoresponsive, amphoteric metal–organic‐framework material that can adsorb multiple salts from saline water at room temperature and effectively release the adsorbed salts into water at elevated temperature is fabricated for efficient water desalination. It exhibits excellent LiCl, NaCl, MgCl2, and CaCl2 adsorption capacities of 0.56, 0.92, 0.25, and 0.39 mmol g−1, respectively, and shows stable thermoresponsive adsorption–desorption cycling performance.
is a critical host for producing recombinant proteins. However, the SDS-PAGE process, including the sample preparation steps, varies among
-related studies, making it impossible to compare findings. ...Hence, this paper provides a simple guide to culture and collect
cells through an OD
measurement and a protocol for SDS-PAGE. These techniques were applied to check the expression of a BgaB, a reporter protein and LukF-PV, a potential vaccine candidate against
, in the cytoplasm of
under the control of a strong promoter, P
. This protocol could be helpful for scientists in preparing samples and generating an SDS-PAGE experiment, as well as favoring the unification of research about protein expression in
.
Aerobic glycolysis in cancer cells, originally observed by Warburg 100 years ago, which involves the production of lactate as the end product of glucose breakdown even in the presence of adequate ...oxygen, is the foundation for the current interest in the cancer-cell-specific reprograming of metabolic pathways. The renewed interest in cancer cell metabolism has now gone well beyond the original Warburg effect related to glycolysis to other metabolic pathways that include amino acid metabolism, one-carbon metabolism, the pentose phosphate pathway, nucleotide synthesis, antioxidant machinery, etc. Since glucose and amino acids constitute the primary nutrients that fuel the altered metabolic pathways in cancer cells, the transporters that mediate the transfer of these nutrients and their metabolites not only across the plasma membrane but also across the mitochondrial and lysosomal membranes have become an integral component of the expansion of the Warburg effect. In this review, we focus on the interplay between these transporters and metabolic pathways that facilitates metabolic reprogramming, which has become a hallmark of cancer cells. The beneficial outcome of this recent understanding of the unique metabolic signature surrounding the Warburg effect is the identification of novel drug targets for the development of a new generation of therapeutics to treat cancer.
Successful male gametogenesis involves orchestration of sequential gene regulation for somatic differentiation in pre-meiotic anthers. We report here the cloning of Male Sterile23 (Ms23), encoding an ...anther-specific predicted basic helix-loop-helix (bHLH) transcription factor required for tapetal differentiation; transcripts localize initially to the precursor secondary parietal cells then predominantly to daughter tapetal cells. In knockout ms23-ref mutant anthers, five instead of the normal four wall layers are observed. Microarray transcript profiling demonstrates a more severe developmental disruption in ms23-ref than in ms32 anthers, which possess a different bHLH defect. RNA-seq and proteomics data together with yeast two-hybrid assays suggest that MS23 along with MS32, bHLH122 and bHLH51 act sequentially as either homo- or heterodimers to choreograph tapetal development. Among them, MS23 is the earliest-acting factor, upstream of bHLH51 and bHLH122, controlling tapetal specification and maturation. By contrast, MS32 is constitutive and independently regulated and is required later than MS23 in tapetal differentiation.
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