Global antimicrobial use in livestock farming: an estimate for cattle, chickens, and pigs.

Livestock farming substantially contributes to the global economy and food security. However, it poses crucial environmental, animal welfare, and public health challenges. The main objective of this study is to quantify the global antimicrobial use (AMU) in cattle, chicken, and pig farming. This information is important for understanding the potential impact of farm AMU on the emergence and spread of antimicrobial resistance among animals and humans. Using the United States Department of Agriculture Production, Supply, and Distribution and the Food and Agriculture Organization databases, we estimated the total supply of cattle (in heads) and its distribution into four weight categories: calves (26%), cows (41%), heifers (4%), and bulls of more than one year (29%). Similarly, we calculated the total supply of pigs (in heads) and divided it into two weight categories: pigs (96%) and sows (4%). For chickens, we considered one weight category. We attributed to each category a standard weight according to the parameters set by the European Medicines Agency (EMA) to determine the animal biomass at risk of antimicrobial treatment, or population correction unit (PCU). Finally, we estimated the global PCUs and then the global AMU based on the average administered to the three species (in mg of active ingredients per kg PCU). With this method, we estimated a global annual AMU of 76 060 tonnes of antimicrobial active ingredients (2019-2021 average), of which 40 697 tonnes (or 53.5%) for cattle, 4 243 tonnes (or 5.6%) for chickens, and 31 120 tonnes (or 40.9%) for pigs. According to our assessment, global AMU leads to almost 20 000 tonnes less than the previous estimates due to a different evaluation of PCUs. In previous studies, PCUs were calculated on the liveweight at slaughtering of animals, while our method considers the age and sex of animals and their average weight at treatment. Our results are consistent with the World Organization for Animal Health (WOAH) estimate of 76 704 tonnes of veterinary antimicrobials globally consumed in 2018 for the total of food-producing animals (the WOAH estimation is based on sales and import data).

Evaluating the contribution of antimicrobial use in farmed animals to global antimicrobial resistance in humans.

Antimicrobial resistance (AMR) is currently regarded by the World Health Organization (WHO) as one of the most significant risks to global public health. The most critical causes of AMR infections in humans are the misuse and overuse of antimicrobials in humans and farmed animals. The rising global demand for food of animal origin encourages the increase of animal production worldwide, especially in developing countries. Simultaneously, current farming practices often extensively use antimicrobials on animals, influencing bacterial AMR incidence. This study aims to evaluate the correlation between antimicrobial use (AMU) in farmed animals and the detection of AMR infections in humans, the effects of enforcing laws in animal farming in a country on AMR situation in the neighbors, and the potential of AMR to spread from one country to another. Using data from 30 largest animal-producing countries in different regions of the world, between 2010 and 2020, and a Spatial Durbin Model (SDM), we found that AMU in farmed animals increases AMR in humans and there is a spatial dependence between countries regarding AMR spreading. Such findings indicate that a globally coordinated strategy regulating AMU on farmed animals may reduce AMR emergence and worldwide spreading.

Flexural strength of polymethyl methacrylate reinforced with high-performance polymer and metal mesh.

BACKGROUND: The flexural strength (FS) of a denture base material is of great concern, and many approaches have been used to strengthen the denture acrylic resins. The present study aimed to evaluate the effect of high-performance polymer (BioHPP) and metal mesh reinforcement on the FS of a heat-cured poly methyl methacrylate (PMMA) acrylic resin. MATERIALS AND METHODS: This experimental study was done on 30 rectangular specimens (64 mm × 13 mm × 3 mm) of a heat-cured PMMA resin. The specimens were divided into three groups (n = 10) to be reinforced with either metal mesh or BioHPP mesh; one group was left nonreinforced, serving as the control group. The FS of specimens was assessed through a 3-point bending test by using a universal testing machine at a crosshead speed of 2 mm/min. Kruskal-Wallis H and Dunn's post hoc tests were used to compare the FS among the groups (alpha = 0.05). RESULTS: The FS in the metal-reinforced group was statistically significantly higher than the two other groups (P < 0.001). However, the FS of the BioHPP-reinforced samples was not statistically significantly higher than the nonreinforced ones (P = 0.614). CONCLUSION: Reinforcing the PMMA with metal mesh significantly enhances its FS while BioHPP has no significant effect on the PMMA FS.

Stress-dependent conformational changes of artemin: Effects of heat and oxidant.

Artemin is an abundant thermostable protein in Artemia embryos and it is considered as a highly efficient molecular chaperone against extreme environmental stress conditions. The conformational dynamics of artemin have been suggested to play a critical role in its biological functions. In this study, we have investigated the conformational and functional changes of artemin under heat and oxidative stresses to identify the relationship between its structure and function. The tertiary and quaternary structures of artemin were evaluated by fluorescence measurements, protein cross-linking analysis, and dynamic light scattering. Based on the structural analysis, artemin showed irreversible substantial conformational lability in responses to heat and oxidant, which was mainly mediated through the hydrophobic interactions and dimerization of the chaperone. In addition, the chaperone-like activity of heated and oxidized artemin was examined using lysozyme refolding assay and the results showed that although both factors, i.e. heat and oxidant, at specific levels improved artemin potency, simultaneous incubation with both stressors significantly triggered the chaperone activation. Moreover, the heat-induced dimerization of artemin was found to be the most critical factor for its activation. It was suggested that oxidation presumably acts through stabilizing the dimer structures of artemin through formation of disulfide bridges between the subunits and strengthens its chaperoning efficacy. Accordingly, it is proposed that artemin probably exists in a monomer-oligomer equilibrium in Artemia cysts and environmental stresses and intracellular portion of protein substrates may shift the equilibrium towards the active dimer forms of the chaperone.

Association of Pathogenic Missense and Nonsense Mutations in Mitochondrial COII Gene with Familial Adenomatous Polyposis (FAP).

Nuclear genetic mutations have been extensively investigated in solid tumors. However, the role of the mitochondrial genome remains uncertain. Since the metabolism of solid tumors is associated with aerobic glycolysis and high lactate production, tumors may have mitochondrial dysfunctions. Familial adenomatous polyposis (FAP) is a rare form| of colorectal cancer and an autosomal dominant inherited condition that is characterized by the progress of numerous adenomatous polyps in the rectum and colon. The present study aimed at understanding the nature and effect of mitochondrial cytochrome c oxidase subunit 2 (COII) gene mutations in FAP tumorigenesis. Fifty-six (26 familial and 30 sporadic) FAP patients and 60 normal controls were enrolled in this study. COII point mutations were evaluated by PCR and direct sequencing methods, and a total of 7 mtDNA mutations were detected (3 missense, 1 nonsense, and 3 synonymous variations). Novel non-synonymous COII gene mutations were mostly in heteroplasmic state. These mutations change amino acid residues in the N-terminal and C-terminal regions of COXII. Bioinformatics analysis and three-dimensional structural modeling predicted that these missense and nonsense mutations have functional importance, and mainly affected on cytochrome c oxidase (complex IV). Also, FAP patients carried a meaningfully higher prevalence of mutations in the COII gene in comparison with healthy controls (P <0.001). Analysis of cancer-associated mtDNA mutation could be an invaluable tool for molecular assessment of FAP so that these findings can be helpful for the development of potential new biomarkers in the diagnosis of cancer for future clinical assessments.

The Effect of Finish Line Design on the Fracture Strength of Zirconia Copings.

STATEMENT OF THE PROBLEM: One of the major concerns about all ceramic crowns is their fracture resistance. PURPOSE: The purpose of this in vitro study was to evaluate the effect of two marginal designs (shoulder 90°, shoulder 135°) on the fracture resistance of zirconia copings. MATERIALS AND METHOD: In this in vitro study, 20 brass dies were prepared using milling machine: 10 with 1mm width shoulder 90° marginal design and the other 10 with 1mm width shoulder 135° finish line design. Zirconia cores with 0.5mm thickness and 30µm cement space were fabricated on brass dies. The copings were cemented on the dies and fracture test was done using a universal testing machine. Data were analyzed using Mann-Whitney test. RESULTS: The mean value of fracture resistance for shoulder 90° finish line design were 368.3±109.4 N and for shoulder 135° finish line design were 518.4±115.5 N. Data analysis revealed a statistically significant difference between groups (p< 0.05). CONCLUSION: The results of this study showed that the finish line design of zirconia copings influences their fracture resistance. A 135° shoulder finish line design can improve the fracture resistance of zirconia crowns.

Latest Trends in Electrochemical Sensors for Neurotransmitters: A Review.

Neurotransmitters are endogenous chemical messengers which play an important role in many of the brain functions, abnormal levels being correlated with physical, psychotic and neurodegenerative diseases such as Alzheimer's, Parkinson's, and Huntington's disease. Therefore, their sensitive and robust detection is of great clinical significance. Electrochemical methods have been intensively used in the last decades for neurotransmitter detection, outclassing more complicated analytical techniques such as conventional spectrophotometry, chromatography, fluorescence, flow injection, and capillary electrophoresis. In this manuscript, the most successful and promising electrochemical enzyme-free and enzymatic sensors for neurotransmitter detection are reviewed. Focusing on the activity of worldwide researchers mainly during the last ten years (2010-2019), without pretending to be exhaustive, we present an overview of the progress made in sensing strategies during this time. Particular emphasis is placed on nanostructured-based sensors, which show a substantial improvement of the analytical performances. This review also examines the progress made in biosensors for neurotransmitter measurements in vitro, in vivo and ex vivo.

Applying mindfulness training to enhance the mental toughness and emotional intelligence of amateur basketball players.

OBJECTIVES: Mindfulness is a proven treatment in clinical settings. Our objective was to examine the feasibility and effect of a mindfulness-training program on the mental resilience and emotional intelligence of amateur basketball players. METHODS: This was a parallel-group, pre- and post- test, randomised controlled trial. Thirty male amateur male basketball players from Tehran, Iran, were assigned randomly into experimental and control groups (n = 15 each). Outcomes were measured using the mindfulness sport inventory, mental toughness (MT) questionnaire and emotional intelligence questionnaire. Data were analysed using ANCOVA and MANCOVA. RESULTS: Mindfulness scores were significantly greater in the intervention group than in the controls following training. The intervention also increased overall MT and all of the component sub scores. The same applied to emotional intelligence and all of its components. CONCLUSIONS: These findings may have implications on sport mindfulness training in increasing the MT and emotional intelligence of athletes.

Fabrication of an ultrasensitive and selective electrochemical aptasensor to detect carcinoembryonic antigen by using a new nanocomposite.

A lable-free electrochemical aptasensor was successfully developed for the sensitive detection of carcinoembryonic antigen as a tumor biomarker. To do this, a ternary nanocomposite of hemin, graphene oxide and multi-walled carbon nanotubes was used. The aptamer can be attached to the surface of a hemin, graphene oxide and multi-walled carbon nanotubes glassy carbon electrode through -NHCO- covalent bonds to form a sensing surface. Through fourier transform infrared spectroscopy and scanning electron microscopy, it was indicated that hemin can be successfully incorporated into hemin, graphene oxide and multi-walled carbon nanotubes. Hemin, which protects graphene nanosheets, also serves as an in-situ probe owing to its well-defined redox properties. Multi-walled carbon nanotubes in the modifier enhance conductivity and facilitate the electron transfer between hemin and the glassy carbon electrode. In this study, carcinoembryonic antigen got specifically bound to the aptamer, and the current changes were used for selective and specific detection of that antigen. The devised aptasensor proved to have excellent performance with a wide linear range of 1.0 × 10-15 - 1.0 × 10-8 gmL-1 and a detection limit of 0.82 fg mL-1. The inter-day and intra-day values of RSD% were obtained in the range of 0.10-2.91 and 2.21-4.56 respectively. According to the experiments conducted on real samples, it may be claimed that the proposed label-free electrochemical aptasensor is capable enough of determining carcinoembryonic antigen in clinical diagnostics.

In vitro ovicidal activity of Peganum harmala seeds extract on the eggs of Fasciola hepatica.

Peganum harmala seeds extract has been previously reported to have antimicrobial and other medicinal properties. The aim of this study was to evaluate the ovicidal activity of the methanolic extract of P. harmala seeds against the eggs of F. hepatica. The phenolic compounds of the methanolic extract of P. harmala seeds were identified by HPLC analysis. Catechin, rutin, p-Coumaric acid, chloregenic acid and hesperetin were found to be the major phenolic compounds. F. hepatica eggs were collected from the gall bladder of naturally infected sheep. The eggs were exposed to two concentrations of P. harmala seeds extract (1 and 3 mg/mL) for 24 and 48 h. To investigate the effect of the P. harmala seeds extract on the miracidial formation, the treated eggs were incubated at 28 °C for 14 days. The results indicated that F. hepatica eggs were susceptible to the methanolic extract of P. harmala seeds. Following 24 h exposure of the eggs to P. harmala seeds extract with concentrations of 1 and 3 mg/mL, the miracidial formation reduced to 5 and 2.2 % respectively (compared with 60 % for the control group). Following 48 h of exposure of the eggs to P. harmala seeds extract with 1 mg/mL concentration, the miracidial formation reduced to 0.5 %. In this exposure time, no miracidial formation was observed in the eggs exposed to P. harmala seeds extract with concentration of 3 mg/mL. Therefore, the results of this study indicated that P. harmala seeds extract has high ovicidal activity against the eggs of F. hepatica. Accordingly, this extract may have the potential flukicidal activity against the immature and mature F. hepatica.

Dimensional stability of two solder index materials.

OBJECTIVES: This study aimed to compare the dimensional accuracy of two indexing materials, an acrylic resin (GC pattern resin) and a castable composite (Bredent). The effect of time lapse until investment was also investigated. MATERIALS AND METHODS: Two standardized brass dies 15 mm apart were prepared and then 20 identical coping-bar assemblies were designed and fabricated by a rapid prototyping device. Each bar was sectioned at the center, and indices were fabricated from an acrylic resin or castable composite (n = 10 per group). The distances between the reference points were measured with a digital microscope at ×80 magnifications at 15 min, 60 min, and 24 h after indexing. Data were statically analyzed using repeated-measure ANOVA (α = 0.05). RESULTS: The distance between the reference points without the coping being joined was considered as the baseline measurement (control group). The mean distance was 19.30 ± 0.04 mm between the reference points where the copings were not joined. When indexed with acrylic resin, the mean ± standard deviation (SD) dimensions were 19.27 ± 0.087 mm (15 min), 19.25 ± 0.09 mm (60 min), and 18.98 ± 0.1 mm (24 h). The mean ± SD dimensions for composite were 19.29 ± 0.087 mm (15 min), 19.28 ± 0.08 mm (60 min), and 19.26 ± 0.08 mm (24 h). All tested groups showed significant differences compared to the control group except when it was indexed with composite and where the distances were measured after 15 and 60 min (P > 0.05). CONCLUSIONS: The most accurate indexed-assemblies belonged to castable composite at 15 and 60 min.

The Effect of Gap Angle on Tensile Strength of Preceramic Base Metal Solder Joints.

STATEMENT OF THE PROBLEM: Soldering is a process commonly used in fabricating dental prosthesis. Since most soldered prosthesis fail at the solder joints; the joint strength is of utmost importance. PURPOSE: The purpose of this study was to evaluate the effect of gap angle on the tensile strength of base metal solder joints. MATERIALS AND METHOD: A total number of 40 Ni-Cr samples were fabricated according to ADA/ISO 9693 specifications for tensile test. Samples were cut at the midpoint of the bar, and were placed at the considered angles by employing an explicitly designed device. They were divided into 4 groups regarding the gap angle; Group C (control group) with parallel gap on steady distance of 0.2mm, Group 1: 10°, Group 2: 20°, and Group3: 30° gap angles. When soldered, the specimens were all tested for tensile strength using a universal testing machine at a cross-head speed of 0.5 mm/min with a preload of 10N. Kruskal-Wallis H test was used to compare tensile strength among the groups (p< 0.05). RESULTS: The mean tensile strength values obtained from the study groups were respectively 307.84, 391.50, 365.18, and 368.86 MPa. The tensile strength was not statistically different among the four groups in general (p≤ 0.490). CONCLUSION: Making the gap angular at the solder joints and the subsequent unsteady increase of the gap distance would not change the tensile strength of the joint.

The effect of bright light on physiological circadian rhythms and subjective alertness of shift work nurses in Iran.

In this study, the effects of bright light (BL) on the rhythms in body temperature, plasma melatonin, plasma cortisol and subjective alertness, in 34 shift work nurses at a university hospital were assessed. They were exposed to very BL (4,500 lx) during 2 breaks (21:15-22:00 and 3:15-4:00) or dim light (300 lx). The subjects were studied under 24 h of realistic conditions during which their plasma cortisol and melatonin were measured at 3-h intervals; their body temperature was also measured during and after night shift work. Subjective alertness was evaluated with the Karolinska sleepiness scale. Administration of BL significantly suppressed night-time melatonin levels. A one-way ANOVA revealed that BL tended to increase cortisol levels and body temperature and significantly improved alertness. These results demonstrate that photic stimulation in a hospital setting can have a powerful influence on the adjustment of the circadian system.