Disturbance of Vancomycin Infusion Flow during Multidrug Infusion: Influence on Endothelial Cell Toxicity

Background: Phlebitis is a common side effect of vancomycin peripheral intravenous (PIV) infusion. As only one PIV catheter is frequently used to deliver several drugs to hospitalized patients through the same Y-site, perturbation of the infusion flow by hydration or other IV medication may influence vancomycin exposure to endothelial cells and modulate toxicity. Methods: We assessed the toxicity of variations in vancomycin concentration induced by drug mass flow variations in human umbilical vein endothelial cells (HUVECs), simulating a 24 h multi-infusion therapy on the same line. Results were expressed as the percentage of viable cells compared with a 100% control, and the Kruskal–Wallis test was used to assess the toxicity of vancomycin. Results: Our results showed that variations in vancomycin concentration did not significantly influence local toxicity compared to a fixed concentration of vancomycin. Nevertheless, the loss of cell viability induced by mechanical trauma mimicking multidrug infusion could increase the risk of phlebitis. Conclusion: To ensure that vancomycin-induced phlebitis must have other causes than variation in drug mass flow, further in vitro experiments should be performed to limit mechanical stress to frequent culture medium change.

Using Live Imaging and FUCCI Embryonic Stem Cells to Rank DevTox Risks: Adverse Growth Effects of PFOA Compared With DEP Are 26 Times Faster, 1,000 Times More Sensitive, and 13 Times Greater in Magnitude

Fluorescent ubiquitination-based cell cycle indicator (FUCCI) embryonic stem cells (ESCs), which fluoresce green during the S-G2-M phases, generate an S-shaped curve for the accumulation of cells during normal stemness (NS) culture with leukemia-inhibitory factor (LIF). Since it was hypothesized that a culture of ESCs was heterogeneous in the cell cycle, it was expected that increased S-G2-M-phases of the cell cycle would make an S-shaped curve parallel to the accumulation curve. Unexpectedly, it was observed that the fraction of FUCCI ESCs in green decreases over time to a nadir at ∼24 h after previous feeding and then rapidly enters S-G2-M-phases after medium change. G1 delay by infrequent medium change is a mild stress, as it does not affect growth significantly when frequency is increased to 12 h. Perfluoro-octanoic acid (PFOA) and diethyl phthalate (DEP) were used as examples of members of the per- and polyfluoroalkyl substances (PFAS) and phthalate families of chemicals, respectively. Two adverse outcomes were used to compare dose- and time-dependent effects of PFOA and DEP. The first was cell accumulation assay by time-lapse confluence measurements, largely at Tfinal/T74 h. The second was by quantifying dominant toxicant stress shown by the suppression of mild stress that creates a green fed/unfed peak. In terms of speed, PFOA is 26 times faster than DEP for producing a time-dependent LOAEL dose at 100 uM (that is, 2 h for PFOA and 52 h for DEP). PFOA has 1000-fold more sensitive LOAEL doses than DEP for suppressing ESC accumulation (confluence) at day 3 and day 2. There were two means to compare the magnitude of the growth suppression of PFOA and DEP. For the suppression of the accumulation of cells measured by confluence at Tfinal/T74h, there was a 13-fold suppression at the highest dose of PFOA > the highest dose of DEP. For the suppression of entry into the cell cycle after the G1 phase by stress on day 1 and 2, there is 10-fold more suppression by PFOA than DEP. The data presented here suggest that FUCCI ESCs can assay the suppression of accumulated growth or predict the suppression of future growth by the suppression of fed/unfed green fluorescence peaks and that PFOA’s adverse effects are faster and larger and can occur at more sensitive lower doses than DEP.

Differentiation of Human-Induced Pluripotent Stem Cell-Derived Endocrine Progenitors to Islet-like Cells Using a Dialysis Suspension Culture System

The production of functional islet-like cells from human-induced pluripotent stem cells (hiPSCs) is a promising strategy for the therapeutic use and disease modeling for type 1 diabetes. However, the production cost of islet-like cells is extremely high due to the use of expensive growth factors for differentiation. In a conventional culture method, growth factors and beneficial autocrine factors remaining in the culture medium are removed along with toxic metabolites during the medium change, and it limits the efficient utilization of those factors. In this study, we demonstrated that the dialysis suspension culture system is possible to reduce the usage of growth factors to one-third in the differentiation of hiPSC-derived endocrine progenitor cells to islet-like cells by reducing the medium change frequency with the refinement of the culture medium. Furthermore, the expression levels of hormone-secretion-related genes and the efficiency of differentiation were improved with the dialysis suspension culture system, possibly due to the retaining of autocrine factors. In addition, we confirmed several improvements required for the further study of the dialysis culture system. These findings showed the promising possibility of the dialysis suspension culture system for the low-cost production of islet-like cells.

Source Separation and Medium Change of Contained Chemical Explosions from Coda Wave Interferometry

Differences in the seismic coda of neighboring events can be used to investigate source location offsets and medium change with coda wave interferometry (CWI). We employ CWI to infer the known relative location between two chemical explosions in Phase I of the Source Physics Experiment (SPE). The inferred displacement between the first, SPE-1, and second, SPE-2, chemical explosion is between 6 and 18 m, with an expectation of 9.2 m, where the known separation is close to 9.4 m. We also employ CWI to find any velocity perturbation due to damage from SPE-2, by comparing its coda with the collocated third SPE chemical explosion, SPE-3. We find that damage due to SPE-2 must be confined to a spherical region with radius less than 10 m and velocity perturbation less than 25%.

An Open-Source Add-On EVOM® Device for Real-Time Transepithelial/Endothelial Electrical Resistance Measurements in Multiple Transwell Samples

This study provides design of a low-cost and open source add-on device that enhances the functionality of the popular EVOM® instrument for transepithelial/endothelial electrical resistance (TEER) measurement. The original EVOM® instrument is designed for measuring TEER in transwell samples manually using a pair of Ag/AgCl electrodes. The inconsistency in electrode placement, temperature variation, and a typically large (12–24 h) time interval between measurements result in large data variabilities. Thus, to solve the current limitation of the EVOM® instrument, we built an add-on device using a custom designed electronic board and a 3D printed electrode holder that allowed automated TEER measurements in multiple transwell samples. To demonstrate the functionality of the device prototype, we monitored TEER in 4 transwell samples containing retinal cells (ARPE-19) for 67 h. Furthermore, by monitoring temperature of the cell culture medium, we were able to detect fluctuations in TEER due to temperature change after the medium change process, and were able to correct the data offset. Although we demonstrated the use of our add-on device on EVOM® instrument only, the concept (multiplexing using digitally controlled relays) and hardware (custom data logger) presented here can be applied to more advanced TEER instruments to improve the performance of those devices.

Development of a mathematical model of the continuous (chemostat) process of culturing pasteurella

One of the most important technological stages in the production of biological preparations intended for the specific prevention of infectious diseases is the cultivation of microorganisms. The synthesis of antigens occurs precisely at this technological stage of vaccine production; the effectiveness of immunopreparations depends on them. In the process of growing bacteria, it is necessary, simultaneously with an increase in the biomass yield, to ensure that the pathogen does not change its biological properties. To do this, it is necessary to create optimal conditions for cultivation, taking into account the physiological state of microorganisms. The technology of manufacturing bacterial vaccines is a multifaceted problem, the key direction of which is the development of controlled processes for the cultivation of microorganisms. At present, obtaining a bacterial mass of microorganisms for the manufacture of vaccines is based on a periodic method of cultivation, during which the properties of cells and the composition of the culture medium change unpredictably. According to a number of researchers, the most efficient in terms of accumulation of bacterial biomass is chemostat cultivation with limitation by the carbon source [1, 2]. The productivity of continuous (chemostat) cultivation of microorganisms significantly exceeds the productivity of the batch method. Therefore, very promising research aimed at organizing the processes of controlled cultivation and, in particular, on continuous methods of growing microorganisms, allowing you to create and maintain for a long time cultures with a constant and precisely defined biomass concentration, phase and growth rate, as well as the ratio of protective antigens [ 3, 4]. The aim of this work is to build an adequate mathematical model of the process of chemostat cultivation of Pasteurella in the production of anti-Pasteurella vaccine in order to optimize it. As a result of the research, the structure of the mathematical model of continuous cultivation of P. multocida was developed, its coefficients were determined, the adequacy of the model to the real process was verified, the obtained mathematical description of the process makes it possible to calculate and select the modes of chemostatic cultivation - the dilution rate D and the initial glucose concentration S0 - to obtain the optimal concentrations of viable pasteurella, the specified productivity values, the degree of substrate conversion, etc. in the manufacture of antibacterial vaccines. In addition, the obtained mathematical dependences make it possible to make a proposal on the metabolic mechanism for increasing the concentration of pasteurella at low dilution rates.

Storable bFGF-Releasing Membrane Allowing Continuous Human iPSC Culture

Basic fibroblast growth factor (bFGF) is a crucial supplement for culture media of human pluripotent stem cells. However, bFGF is extremely unstable under cell culture conditions, which makes frequent (generally every day) medium refreshment requisite. We recently developed a water-floatable, bFGF-releasing membrane via a simple bFGF adsorption process following oxygen plasma treatment by utilizing a polyethylene nonwoven fabric as an adsorbent. This membrane allowed sustained release of bFGF while floating on medium, thereby keeping the bFGF concentration in the medium sufficient for maintaining human-induced pluripotent stem cells (iPSCs) in a proliferative and pluripotent state for as long as 3 days. In this study, lyophilization was applied to the membrane to stabilize bFGF. The sustained bFGF-releasing function of the membrane was kept unchanged even after lyophilization and subsequent cryopreservation at −30 °C for 3 months. The cryopreserved membrane supported proliferation and colony formation of human iPSCs while retaining their viability and pluripotency in a medium-change-free continuous culture for 3 days. The present bFGF-releasing membrane is ready-to-use, storable for at least 3 months, and obviates daily medium refreshment. Therefore, it is a new and more practical bFGF supplement for culture media of human stem cells.

Simulation Analysis of Sedimentation Separation of Suspended Solids Sewage in Oil Field Based on COMSOL

After oil and water separation, the produced sewage needs to be treated in a series of ways and injected into the ground if it reaches the discharge standard in oilfields. Sedimentation separation is one of the most important process. In order to study the law of settlement, a set of settlement simulation device was set up, and the raw wastewater was extracted from the oil production plant for settlement experiment, and the relevant data were gathered. Comsol software is used to model and analyse the model. Through comparing the calculation results with the experimental data, the velocity and concentration of liquid-solid two-phase medium change rules are concluded, which lays a foundation for further research on efficient treatment of oilfield sewage.

RECOMENDAÇÕES PARA A IMPLANTAÇÃO DE SISTEMAS DE GESTÃO AMBIENTAL DE ACORDO COM A ISO 14001:2015

<p>Com a reformulação da norma ISO14001, em 2015, surgiram novos desafios para as organizações implementarem o Sistemas de Gestão Ambiental (SGA). O objetivo deste trabalho foi analisar as alterações dos requisitos apresentados na versão da ISO 14001:2015 e propor recomendações para a implantação do SGA. Os procedimentos metodológicos adotados foram realizar a análise documental comparativa dos requisitos das versões da norma (2004 e 2015) e utilizá-la como base para um estudo exploratório, por meio da aplicação de questionários para consultores e auditores que trabalhavam com a ISO 14001. A análise documental comparativa possibilitou a avaliação de 44 requisitos quanto às orientações para a implantação do SGA. Os resultados mostraram 07 itens classificados com grau de alteração alto; 12 itens, com grau de alteração médio; e 25 itens, com grau de alteração baixo. A partir das respostas aos 30 questionários e da análise documental realizada, este trabalho produziu 08 recomendações principais para ajudar as organizações na implantação do SGA, de acordo com a nova versão da ISO 14001. Além de ajudar no processo de desenvolvimento de SGAs, estas recomendações podem contribuir para novas pesquisas.</p><p> </p><p align="center">RECOMMENDATIONS FOR THE IMPLEMENTATION OF ENVIRONMENTAL MANAGEMENT SYSTEMS ACCORDING TO ISO 14001:2015</p>After the recasting of ISO 14001 normative, in 2015, new challenges were established in relation to the implementation of Environmental Management Systems (EMS) by the organizations. The aim of this work was to evaluate the changes of requirements presented in the ISO 14001:2015 version and to propose recommendations to the implementation of EMS. The methodological procedures adopted were the comparative documentary analysis of rule versions (2004 and 2015), serving as the basis for the exploratory study with application of surveys for consultants and auditors that worked with the ISO 14001. The comparative documentary analysis enabled the assessment of 44 requirements in relation to the orientations for the implementation of EMS. The results showed 07 items evaluated with high change level, 12 items evaluated with medium change level and 25 items evaluated with low change level. From the responses received of the 30 questionnaires and the documentary analysis realized, 08 main recommendations were established to help the organizations in the implementation of EMS based on the new ISO 14001 version. Besides contributing in the development process of EMS, these recommendations can help to new research.

Seismic monitoring of explosions in the Central site of the Kumtor deposit, Tien Shan

Seismic monitoring of explosions was carried out at the local area of the Central site of the Kumtor deposit for January 2017 - January 2018. Velocities of seismic longitudinal and transverse waves, their ratios (VP, VS, VP/VS), maximum amplitudes and their ratios (AP, AS, AS/AP) were studied, and average values with standard deviation values were determined, and hierarchies of cycles are distinguished in their variations in time. It is noted that the ratios of VP, VS, VP/VS reflect the state of the crust medium, small values of VP, VS, VP/VS express possible manifestation of fluids, and large value of the ratio VP/VS – possible manifestation of partial melting, large values of VP, VS – possible manifestation of relatively high pressures. Physical parameters of the medium are estimated: seismic parameter Φ, Poisson's ratio, shear modulus, and bulk modulus. It is established that these physical parameters are dynamic parameters that depend on the frequency of geodynamic processes, namely, in cycles, for example, of the third order with a relatively high frequency, relatively small values of modules (physical parameters of the medium) are observed, and in cycles of the second and first orders with a relatively low frequency, relatively large values of modules are observed. Changes in the values of AP, AS, AS/AP, and the degree of seismic waves’ absorption are predetermined by physical parameters and the state of the medium. Change in the penetration depth of seismic waves from an explosion is noted in the range of about 8-35 km