Point-of-Use Detection of Environmental Fluoride via a Cell-Free Riboswitch-Based Biosensor

AbstractAdvances in biosensor engineering have enabled the design of programmable molecular systems to detect a range of pathogens, nucleic acids, and chemicals. Here, we engineer and field-test a biosensor for fluoride, a major groundwater contaminant of global concern. The sensor consists of a cell-free system containing a DNA template that encodes a fluoride-responsive riboswitch regulating genes that produce a fluorescent or colorimetric output. Individual reactions can be lyophilized for long-term storage and detect fluoride at levels above 2 parts per million, the EPA’s most stringent regulatory standard, in both laboratory and field conditions. Through onsite detection of fluoride in a real-world water source, this work provides a critical proof-of-principle for the future engineering of riboswitches and other biosensors to address challenges for global health and the environment.

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Comparison of biofilm formation and water quality when water from different sources was stored in large commercial water storage tanks

Journal of Water and Health ◽

10.2166/wh.2012.014 ◽

2012 ◽

Vol 11 (1) ◽

pp. 30-40 ◽

Cited By ~ 6

Author(s):

Venessa van der Merwe ◽

Stacey Duvenage ◽

Lise Korsten

Keyword(s):

Water Quality ◽

Potable Water ◽

Water Storage ◽

Water Source ◽

Sampling Point ◽

Storage Tanks ◽

Long Term Storage ◽

Biofilm Development ◽

Term Storage

Rain-, ground- and municipal potable water were stored in low density polyethylene storage tanks for a period of 90 days to determine the effects of long-term storage on the deterioration in the microbial quality of the water. Total viable bacteria present in the stored water and the resultant biofilms were enumerated using heterotrophic plate counts. Polymerase chain reaction (PCR) and Colilert-18® tests were performed to determine if the faecal indicator bacteria Escherichia coli was present in the water and in the biofilm samples collected throughout the study. The municipal potable water at the start of the study was the only water source that conformed to the South African Water Quality Guidelines for Domestic Use. After 15 days of storage, this water source had deteriorated microbiologically to levels considered unfit for human consumption. E. coli was detected in the ground- and potable water and ground- and potable biofilms periodically, whereas it was detected in the rainwater and associated biofilms at every sampling point. Imperfections in the UV resistant inner lining of the tanks were shown to be ecological niches for microbial colonisation and biofilm development. The results from the current study confirmed that long-term storage can influence water quality and increase the number of microbial cells associated with biofilms on the interior surfaces of water storage tanks.

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Sustained use of a household-scale water filtration device in rural Cambodia

Journal of Water and Health ◽

10.2166/wh.2009.085 ◽

2009 ◽

Vol 7 (3) ◽

pp. 404-412 ◽

Cited By ~ 38

Author(s):

Joe Brown ◽

S. Proum ◽

M. D. Sobsey

Keyword(s):

Water Treatment ◽

Water Source ◽

Drinking Water Source ◽

Ceramic Water Filters ◽

Hygiene Practices ◽

Point Of Use ◽

Sanitation And Hygiene ◽

Water Filters ◽

Over Time

The effectiveness of point-of-use water treatment may be limited by declining use over time, particularly when water treatment is introduced via targeted intervention programmes. In order to evaluate the long-term uptake and use of locally produced ceramic water filters in rural Cambodia, we visited households that had received filters as part of NGO-subsidized distribution programmes over a 4 year period from 2002 to 2006. Of the more than 2,000 filters distributed, we visited 506 randomly selected households in 13 villages spanning three provinces to assess filter time in use and to collect data on factors potentially correlated with long-term use. Results indicate that filter use declined at the rate of approximately 2% per month after implementation, largely owing to breakages, and that, controlling for time since implementation, continued filter use over time was most closely positively associated with: related water, sanitation and hygiene practices in the home; cash investment in the technology by the household; and use of surface water as a primary drinking water source.

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Optimization of culture conditions for the maintenance of Onchocerca gutturosa adult worms in vitro

Journal of Helminthology ◽

10.1017/s0022149x00008579 ◽

1986 ◽

Vol 60 (4) ◽

pp. 323-330 ◽

Cited By ~ 16

Author(s):

Simon Townson ◽

C. Connelly ◽

R. Muller

Keyword(s):

Calf Serum ◽

Culture Conditions ◽

Foetal Calf Serum ◽

Free System ◽

Gas Phases ◽

Mdbk Cells ◽

A Cell ◽

Series Of Experiments

ABSTRACTA series of experiments examined the effects of various media, serum supplements, gas phases and the incorporation of mammalian cell feeder layers on the survival on Onchocerca gutturosa adult worms in vitro. The survival of male worms was poor in all media tested that were not supplemented with inactivated foetal calf serum (IFCS), with improved but variable survival in media supplemented with 10–30% IFCS. Using a cell-free system in an atmosphere of 5% CO2in air, good results were obtained in medium NCTC 135 + 10% IFCS (median survival time 39 days, range 25–41). Marginally better survival was obtained with the same medium in an atmosphere of 95% N2/5% CO2 (medium 45 days, range 25–56)and with a 1:1 mixture of media NCTC 135 and IMDM+10% IFCS(medium 38 days, range 38–51). Survival was enhanced in culture systems which incorporated bovine kindney (MDBK) cells, bovine trachea (EBTR) cells and monkey kidney (LLCMK2) cells. Exceptionally long survival was obtained using medium MEM+10% IFCS+LLCMK2 cells under a gas phase of 5% CO2in air, in which male worms survived from approximately 6 to over 7 months. Under similar conditions, female worms were also maintained for periods of up to 6 months and 5 out of 18 specimens released microfilariae into the culture system. The long-term culture described in this study will be useful for basic biochemical, chemotherapeutic and immunological studies in vitro.

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On-Board Reagent Storage and Release by Solvent-Selective, Rotationally Opened Membranes – A Digital Twin Approach

10.33774/chemrxiv-2021-pvb0t ◽

2021 ◽

Author(s):

Jens Ducrée

Keyword(s):

Point Of Care ◽

Spindle Motor ◽

Digital Twin ◽

Long Term Storage ◽

Point Of Use ◽

Resource Poor ◽

Algorithmic Design ◽

Novel Concept ◽

Term Storage

Decentralized bioanalytical testing in resource-poor settings ranges among the prime applications of microfluidic systems. The high operational autonomy in such point-of-care / point-of-use scenarios requires on-board stored liquid reagents, which need to be safely contained during long-term storage, transport and handling, and reliably released prior to activation. Over the recent decades, centrifugal microfluidic technologies have demonstrated the capability of integrated, automated and parallelized sample preparation and detection of bioanalytical protocols. This paper introduces a novel concept for onboard storage of liquid reagents which can be delivered in a well-defined manner by a rotational stimulus of the system-innate spindle motor, while still aligning with the conceptual simplicity of such “Lab-on-a-Disc” (LoaD) concepts. The reagent storage technology is captured by a digital twin which allows making complex performance analysis and algorithmic design optimization according to given objectives as expressed by target metrics.

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Cryopreservation of Hydractinia symbiolongicarpus sperm to support community-based repository development for preservation of genetic resources

10.1101/2020.11.03.366344 ◽

2020 ◽

Author(s):

Aidan L. Huene ◽

Matthew L. Nicotra ◽

Virginia M. Weis ◽

Terrence R. Tiersch

Keyword(s):

Genetic Resources ◽

Model Organism ◽

Community Based ◽

Community Needs ◽

Hydractinia Symbiolongicarpus ◽

Research Fields ◽

Long Term Storage ◽

Genomic Tools ◽

A Cell

AbstractHydractinia symbiolongicarpus is an emerging model organism in which cutting-edge genomic tools and resources are being developed for use in a growing number of research fields. However, one limitation of this model system is the lack of long-term storage for genetic resources. Our goal in this study was to establish a generalizable approach to sperm cryopreservation that would support future repository development and could be applied to many species according to available resources. Our approach was to: 1) Assess sperm characteristics and standardize collection and processing; 2) Assess acute toxicity to cryoprotectants, and 3) Evaluate and refine freezing conditions to permit post-thaw fertilization and produce viable offspring. By following this approach, we found that Hydractinia sperm incubated in 5% DMSO, equilibrated at 4°C for 20 min, and cooled at a rate of 20°C/min to - 80°C at a cell concentration of 108-109/mL in 0.25-mL aliquots were able to fertilize 150-300 eggs which yielded offspring that could metamorphose into juvenile polyps. In addition, improvements were made for processing sperm using a customized 3-D printed collection system. Other opportunities for improvement include optimizing the volumetric sperm-to-egg ratio for fertilization. Establishing repository capabilities for the Hydractinia research community will be essential for future development, maintenance, protection, and distribution of genetic resources. More broadly, this application-based approach highlights the long-term value of establishing repository-level resources that can be expanded to fit community needs.

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Primer RNA for DNA synthesis on single-stranded DNA template in a cell free system fromDrosophila melanogasterembryos

Nucleic Acids Research ◽

10.1093/nar/11.11.3433 ◽

1983 ◽

Vol 11 (11) ◽

pp. 3433-3450 ◽

Cited By ~ 11

Author(s):

Kin-ya Yoda ◽

Tuneko Okazaki

Keyword(s):

Dna Synthesis ◽

Single Stranded Dna ◽

Free System ◽

Cell Free System ◽

A Cell ◽

Dna Template ◽

Primer Rna

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Influence of the Calendar Aging on the Cycle Aging of LiNiMnCoO2 Lithium-Ion Batteries

Journal of The Electrochemical Society ◽

10.1149/1945-7111/ac405a ◽

2021 ◽

Author(s):

Wen-Feng Cai ◽

Kuo-Ching Chen

Keyword(s):

Late Stage ◽

Lithium Ion ◽

Storage Conditions ◽

Cycle Life ◽

Long Term Storage ◽

Capacity Loss ◽

Rest Time ◽

A Cell ◽

Semi Empirical

Abstract An experimental and theoretical study of lithium nickel manganese cobalt oxide (NMC) cells with a long rest time under different storage temperatures is carried out. We show that the long-term storage of a cell decisively influences its cycle life, and this influence is more pronounced at the late stage of the battery cycle life. Experimental outcomes demonstrate that the cycle life drops as the storage span lengthens, and the storage under relatively low temperature helps to reduce the cycle fading. Based on the experimental data, we identify the point on the fading trajectory to separate the early-medium stage and the late stage for the cycle aging. By extending the previously proposed semi-empirical model to incorporate the two-stage fading into a single formulation, the cycling capacity loss of the stored NMC cells is predicted. An incremental capacity analysis is further performed to assess the cycle fading of the cells under various storage conditions.

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Preparation And elemental analysis of ancient fibers

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100126846 ◽

1987 ◽

Vol 45 ◽

pp. 410-411

Author(s):

Allen Angel ◽

Kathryn A. Jakes

Keyword(s):

Cross Sections ◽

Physical Structure ◽

Energy Dispersive ◽

Archaeological Sites ◽

X Ray ◽

Long Term Storage ◽

Backscattered Electron ◽

Electron Imaging

Fabrics recovered from archaeological sites often are so badly degraded that fiber identification based on physical morphology is difficult. Although diagenetic changes may be viewed as destructive to factors necessary for the discernment of fiber information, changes occurring during any stage of a fiber's lifetime leave a record within the fiber's chemical and physical structure. These alterations may offer valuable clues to understanding the conditions of the fiber's growth, fiber preparation and fabric processing technology and conditions of burial or long term storage (1).Energy dispersive spectrometry has been reported to be suitable for determination of mordant treatment on historic fibers (2,3) and has been used to characterize metal wrapping of combination yarns (4,5). In this study, a technique is developed which provides fractured cross sections of fibers for x-ray analysis and elemental mapping. In addition, backscattered electron imaging (BSI) and energy dispersive x-ray microanalysis (EDS) are utilized to correlate elements to their distribution in fibers.

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Modelling of Moisture Movement in Wood during Outdoor Storage

Nonlinear Analysis Modelling and Control ◽

10.15388/na.2001.6.1.15210 ◽

2001 ◽

Vol 6 (2) ◽

pp. 3-14 ◽

Cited By ~ 23

Author(s):

R. Baronas ◽

F. Ivanauskas ◽

I. Juodeikienė ◽

A. Kajalavičius

Keyword(s):

Experimental Data ◽

Finite Difference ◽

Climatic Conditions ◽

Two Dimensional ◽

Moisture Movement ◽

Finite Difference Technique ◽

Long Term Storage ◽

Space Formulation ◽

Term Storage

A model of moisture movement in wood is presented in this paper in a two-dimensional-in-space formulation. The finite-difference technique has been used in order to obtain the solution of the problem. The model was applied to predict the moisture content in sawn boards from pine during long term storage under outdoor climatic conditions. The satisfactory agreement between the numerical solution and experimental data was obtained.

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