Send more data: a systematic review of mathematical models of antimicrobial resistance

Abstract Background Antimicrobial resistance is a global health problem that demands all possible means to control it. Mathematical modelling is a valuable tool for understanding the mechanisms of AMR development and spread, and can help us to investigate and propose novel control strategies. However, it is of vital importance that mathematical models have a broad utility, which can be assured if good modelling practice is followed. Objective The objective of this study was to provide a comprehensive systematic review of published models of AMR development and spread. Furthermore, the study aimed to identify gaps in the knowledge required to develop useful models. Methods The review comprised a comprehensive literature search with 38 selected studies. Information was extracted from the selected papers using an adaptation of previously published frameworks, and was evaluated using the TRACE good modelling practice guidelines. Results None of the selected papers fulfilled the TRACE guidelines. We recommend that future mathematical models should: a) model the biological processes mechanistically, b) incorporate uncertainty and variability in the system using stochastic modelling, c) include a sensitivity analysis and model external and internal validation. Conclusion Many mathematical models of AMR development and spread exist. There is still a lack of knowledge about antimicrobial resistance, which restricts the development of useful mathematical models

Stability Analysis of Mathematical Model including Pathogen-Specific Immune System Response with Fractional-Order Differential Equations

In this study, the mathematical model examined the dynamics between pathogen and specific immune system cells (memory T cells) for diseases such as chronic infection and cancer in which nonspecific immune system cells are inadequate to destroy the pathogen and has been suggested by using a system of the fractional-order differential equation with multi-orders. Qualitative analysis of the proposed model reveals the equilibrium points giving important ideas about the proliferation of the pathogen and memory T cells. According to the results of this analysis, the possible scenarios are as follows: the absence of both pathogen and memory T cells, only the existence of pathogen, and the existence of both pathogen and memory T cells. The qualitative analysis of the proposed model has expressed the persistent situations of the disease where the memory T cells either do not be able to respond to the pathogen or continue to exist with the disease-causing pathogen in the host. Results of this analysis are supported by numerical simulations. In the simulations, the time-dependent size of the tumor population under the pressure of the memory T cells was tried to be estimated

Novel PSt/PGMA/PIN ternary composite for SPE and analysis of some heavy metals in various cosmetics and food products by flame AAS

In this investigation, a solid-phase extraction (SPE) process was improved for selective separation of Cr, Cu, Fe, Mn, Pb and Zn ions on novel ternary composite. These heavy metals were analyzed by flame atomic absorption spectrometry (Flame-AAS). To prepare the novel ternary composite, FeCl(3)was used as an oxidant agent in the chemical polymerization technique by formating polystyrene/polyglycidylmethacrylate/polyindole(PSt/PGMA/PIN) [25:25:50]. The structure of novel ternary composite was characterized by FTIR, TGA, X-RD and BET analysis technique. Themorphological surface analysis has been carried out by using SEM and AFM technique. Morphological studies have been show that composite has a smooth surface. To maximum recoveries of heavy metals, the optimum experimental conditions and analytical parameters were searched. These quantitative recoveries of analytes ions were determined at pH7. The detection limits (DL) were found as minimum of 0.9 mu g/L and maximum 1.4 mu g/L for Cr, Cu, Fe, Mn, Pb and Zn ions. Relative standard deviation (RSD) of the developed SPE process is below 3.3%. This improved SPE process is simple and selective. By the improved extraction method in which PSt/PGMA/PIN ternary composite used as solid phase, analyte ions were determined in certified reference material (CRM), various cosmetic and food products by flame AAS