Toxic Chemical and their Neutralising Agents in Porous Media

The UK Government Decontamination Service advises central Govern- ment on the national capability for the decontamination of buildings, infrastructure, transport and open environment, and be a source of expertise in the event of a chemical, biological, radiological and nuclear (CBRN) incident or major release of HazMat materials. The study group constructed mathematical models to describe the depth to which a toxic chemical may seep into an initially dry porous substrate, and of the neutralisation process between a decontaminant and the imbibed chemical. The group recognised that capillary suction was the dominant process by which the contaminant spreads in the porous substrate. Therefore, in the first instance the absorption of the contaminant was modelled using Darcy’s law. At the next level of complication a diffuse interface model based on Richards’ equation was employed. The results of the two models were found to agree at early times, while at later times we found that the diffuse interface model predicted the more realistic scenario in which the contaminant has seeped deeper into the substrate even in the absence of further contaminant being supplied at the surface. The decontamination process was modelled in two cases; first, where the product of the decontamination reaction was water soluble, and the second where the reaction product formed soluble in the contaminant phase and of similar density. These simple models helped explain some of the key physics involved in the process, and how the decontamination process might be optimised. We found that decontamination was most effective in the first of these two cases. The group then sought to incorporate hydrodynamic effects into the reaction model. In the long wavelength limit, the governing equations reduced to a one-dimensional Stefan model similar to the one considered earlier. More detailed approximations and numerical simulations of this model were beyond the scope of this study group, but provide an entry point for future research in this area

Multiscale modeling of a rectifying bipolar nanopore : comparing Poisson-Nernst-Planck to Monte Carlo

In the framework of a multiscale modeling approach, we present a systematic study of a bipolar rectifying nanopore using a continuum and a particle simulation method. The common ground in the two methods is the application of the Nernst-Planck (NP) equation to compute ion transport in the framework of the implicit-water electrolyte model. The difference is that the Poisson-Boltzmann theory is used in the Poisson-Nernst-Planck (PNP) approach, while the Local Equilibrium Monte Carlo (LEMC) method is used in the particle simulation approach (NP+LEMC) to relate the concentration profile to the electrochemical potential profile. Since we consider a bipolar pore which is short and narrow, we perform simulations using two-dimensional PNP. In addition, results of a non-linear version of PNP that takes crowding of ions into account are shown. We observe that the mean field approximation applied in PNP is appropriate to reproduce the basic behavior of the bipolar nanopore (e.g., rectification) for varying parameters of the system (voltage, surface charge, electrolyte concentration, and pore radius). We present current data that characterize the nanopore’s behavior as a device, as well as concentration, electrical potential, and electrochemical potential profiles

Preoperative HE4, CA125 and ROMA in the differential diagnosis of benign and malignant adnexal masses

BACKGROUND: The aim of this study was to evaluate HE4, CA125 and ROMA in the preoperative differentiation benign ovarian diseases from epithelial ovarian cancer depending on the menopausal status. METHODS: In order to estimate markers’ concentrations in the serum of women with benign ovarian disease (n = 128) and with epithelial ovarian carcinoma (n = 96) the electrochemiluminescence (ECLIA) technique has been applied. RESULTS: Using the ROC analysis, although no statistical differences were found among their AUCs, the ROMA algorithm seems to be effective in gathering the diverse performance of HE4 and CA125. The AUC for HE4, CA125 and ROMA for all patients were: 0.895; 0.879 and 0.918, respectively. At established new optimal cutoff values for HE4, CA125 and ROMA we found higher specificity in postmenopausal compared to premenopausal women (96.9 vs 89.8 % and 97.7 vs 84.1 % and 95.9 vs 89.1 %, respectively). The sensitivity of HE4 in pre- and postmenopausal women was similar (83.5 vs 83.8 %), while for CA125 was the highest in premenopausal women (87.0 vs 84.1 %). For HE4, CA125 and ROMA the negative predictive value was high (97.6, 93.9 and 94.4 %, respectively). CONCLUSIONS: The ROMA algorithm shows the best diagnostic performance to distinguish epithelial ovarian cancer from benign ovarian disease. We found the high specificity of HE4 and CA125 while differentiating ovarian benign diseases from epithelial ovarian cancer in postmenopausal women and the high sensitivity of CA125 in detecting epithelial ovarian cancer in premenopausal patients

Multiscale analysis of the effect of surface charge pattern on a nanopore’s rectification and selectivity properties: From all-atom model to Poisson-Nernst-Planck

We report a multiscale modeling study for charged cylindrical nanopores using three modeling levels that include (1) an all-atom explicit-water model studied with molecular dynamics, and reduced models with implicit water containing (2) hard-sphere ions studied with the Local Equilibrium Monte Carlo simulation method (computing ionic correlations accurately), and (3) point ions studied with Poisson-Nernst-Planck theory (mean-field approximation). We show that reduced models are able to reproduce device functions (rectification and selectivity) for a wide variety of charge patterns, that is, reduced models are useful in understanding the mesoscale physics of the device (i.e., how the current is produced). We also analyze the relationship of the reduced implicit-water models with the explicit-water model and show that diffusion coefficients in the reduced models can be used as adjustable parameters with which the results of the explicit- and implicit-water models can be related. We find that the values of the diffusion coefficients are sensitive to the net charge of the pore but are relatively transferable to different voltages and charge patterns with the same total charge

Investigation on the effects of guava (Psidium guajava L.) infusions on germination, root tips and meristematic cells of Latuca sativa

Guava (Psidium guajava L.) is a plant often employed in popular medicine. Recently several studies have alerted about the toxicity of substances present in medicinal plants, which can pose risks to the human health. In this sense, the present work aimed to investigate the phytotoxic, cytotoxic and genotoxic action of three guava varieties - Paluma, Pedro Sato and Roxa (purple) - on the plant test system Lactuca sativa L. Thus, macro- and microscopic evaluations were carried out for five infusion concentrations (2.5, 5.0, 10.0, 20.0 and 40.0 g.L-1) prepared from each variety. Distilled water was used as negative control. Chromatographic and spectroscopic analysis by HPLC-PAD indicated that the chemical composition of the infusion of Roxa is different than that of the infusions of the varieties Paluma and Pedro Sato. It was observed that seed germination and root growth in L. sativa exposed to infusions decreased with increasing infusion concentration, regardless of the tested cultivar. For the mitotic index, no statistical differences were observed. On the other hand, a significant increase in the frequency of cell cycle alterations was verified, especially for the highest concentrations tested. The cytogenotoxic was significant. Therefore, guava should not be used indiscriminately in popular medicine.A goiaba (Psidium guajava L.) é uma planta bastante utilizada na medicina popular. Recentemente alguns trabalhos tem alertado acerca da toxicidade de substâncias presentes em plantas medicinais, o que pode trazer riscos à saúde humana. Neste sentido, o presente trabalho objetivou investigar a ação fitotóxica, citotóxica e genotóxica de três variedades de goiaba - Paluma, Pedro Sato e Roxa - no sistema teste vegetal Lactuca sativa L. Assim, foram realizadas avaliações macro- e microscópicas para cinco concentrações de infusões (2,5, 5,0, 10,0, 20,0 e 40,0 g.L-1) preparadas a partir de cada variedade. A água destilada foi usada como controle negativo. As análises cromatográficas e espectroscópicas por HPLC-PAD indicaram que a composição química da infusão da Roxa é diferente das infusões das variedades Paluma e Pedro Sato. Foi observado que a germinação das sementes e o crescimento da raiz em L. sativa expostas às infusões diminuem com o aumento da concentração da infusão, independentemente da cultivar testada. Para o índice mitótico, diferenças estatísticas não foram observadas. Por outro lado, foi verificado um aumento significativo na frequência de alterações do ciclo celular, especialmente para as maiores concentrações testadas. O efeito citogenotóxico foi significativo. Portanto, a goiaba não deve ser utilizada indiscriminadamente na medicina popular.Universidade Federal do Espírito Santo Centro de Ciências Agrárias Departamento de BiologiaUniversidade Federal de Lavras Departamento de BiologiaUniversidade Estadual Paulista Faculdade de Ciências Departamento de QuímicaUniversidade Estadual Paulista Faculdade de Ciências Departamento de Químic

Environmental and recombinant microorganisms for biopharmaceuticals production

Current, very fast development of genetic engineering and protein engineering (main segments of modern biotechnology) is a good way for commercially production of proteins, which benefit biopharmaceutical, the enzyme and agricultural industries. These products augment the fields of medicine, diagnostics, food, nutrition, detergents, textiles, leather, paper, pulp, polymers and plastics. Proteins with biopharmaceutical application are mainly clinical reagents, vaccines and drugs. During the last decade, the pharmaceutical biotechnology represents the fastest growing segment in the biotechnology sector. Production of recombinant proteins for use as pharmaceuticals, is a multi-billion dollar industry. One third of the biopharmaceuticals has come from microorganisms, such as Escherichia coli and yeast. The selection of expression systems depends on the size and biochemical status of proteins. Large proteins and proteins that require glycosylation are usually expressed in a mammalian cells, fungi or the baculovirus system. Smaller proteins are produced by prokaryotic cells. There are some very useful advantages for prokaryotic recombinant expression systems: it is easy of culture, very rapid cell growth with possibility of IPTG expression induction and quite simple product purification. On the other hand, for very large proteins, for S-S rich proteins and proteins which require post-translational modifications, bacteria, usually E. coli strains are not robust system. Better are yeasts with very popular species Saccharomyces cerevisiae and Pichia pastoris. This article presents the current application of microbes as production platforms for recombinant proteins and its genetic engineering for the use as biopharmaceuticals

Specific for DNA damages GFP microbial biosensor as a tool for genotoxic action assessment of environmental pollution

In the presented paper, autofluorescent reporter of Escherichia coli K-12 recA::gfpmut2 strain, which contained a plasmid-borne transcriptional fusion between DNA-damage inducible recA promoter involved in the SOS regulon response and fast folding GFP variant reporter gene-gfpmut2, have been used. GFP-based bacterial biosensors allowed the detection of bacterial cells response to selected tested genotoxic compounds such as mitomycin C (MMC), actinomycin D, N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and formaldehyde (CH2O). Experiment indicated that E. coli K-12 recA::gfpmut2 biosensor strain is more specific and sensitive for especially two genotoxins: actinomycin D and MNNG and with very low response to other agents. So it was concluded that for formaldehyde and MMC E. coli K-12 recA::gfpmut2 genetic system is disqualified for genotoxicity screening