scholarly journals Nanopore-based DNA sequencing sensors and CMOS readout approaches

Sensor Review ◽  
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Mehdi Habibi ◽  
Yunus Dawji ◽  
Ebrahim Ghafar-Zadeh ◽  
Sebastian Magierowski
Keyword(s):  
Dna Sequencing ◽  
Electrochemical Cell ◽  
Downstream Processing ◽  
Low Noise ◽  
Sensor Technology ◽  
Signal Acquisition ◽  
Content Type ◽  
Readout Circuits ◽  
Capacitance Effect ◽  
Human Genome Assembly

Purpose Nanopore-based molecular sensing and measurement, specifically DNA sequencing, is advancing at a fast pace. Some embodiments have matured from coarse particle counters to enabling full human genome assembly. This evolution has been powered not only by improvements in the sensors themselves, but also in the assisting microelectronic CMOS readout circuitry closely interfaced to them. In this light, this paper aims to review established and emerging nanopore-based sensing modalities considered for DNA sequencing and CMOS microelectronic methods currently being used. Design/methodology/approach Readout and amplifier circuits, which are potentially appropriate for conditioning and conversion of nanopore signals for downstream processing, are studied. Furthermore, arrayed CMOS readout implementations are focused on and the relevant status of the nanopore sensor technology is reviewed as well. Findings Ion channel nanopore devices have unique properties compared with other electrochemical cells. Currently biological nanopores are the only variants reported which can be used for actual DNA sequencing. The translocation rate of DNA through such pores, the current range at which these cells operate on and the cell capacitance effect, all impose the necessity of using low-noise circuits in the process of signal detection. The requirement of using in-pixel low-noise circuits in turn tends to impose challenges in the implementation of large size arrays. Originality/value The study presents an overview on the readout circuits used for signal acquisition in electrochemical cell arrays and investigates the specific requirements necessary for implementation of nanopore-type electrochemical cell amplifiers and their associated readout electronics.

scholarly journals Engineering Cyanobacterial Cell Morphology for Enhanced Recovery and Processing of Biomass

2017 ◽  
Vol 83 (9) ◽  
Author(s):  
Adam Jordan ◽  
Jenna Chandler ◽  
Joshua S. MacCready ◽  
Jingcheng Huang ◽  
Katherine W. Osteryoung ◽  
...  
Keyword(s):  
Cell Division ◽  
Cell Morphology ◽  
Dynamic Range ◽  
Enhanced Recovery ◽  
Downstream Processing ◽  
Crop Species ◽  
Content Type ◽  
Alternative Crop ◽  
Cell Harvesting ◽  
Broad Dynamic Range

ABSTRACT Cyanobacteria are emerging as alternative crop species for the production of fuels, chemicals, and biomass. Yet, the success of these microbes depends on the development of cost-effective technologies that permit scaled cultivation and cell harvesting. Here, we investigate the feasibility of engineering cell morphology to improve biomass recovery and decrease energetic costs associated with lysing cyanobacterial cells. Specifically, we modify the levels of Min system proteins in Synechococcus elongatus PCC 7942. The Min system has established functions in controlling cell division by regulating the assembly of FtsZ, a tubulin-like protein required for defining the bacterial division plane. We show that altering the expression of two FtsZ-regulatory proteins, MinC and Cdv3, enables control over cell morphology by disrupting FtsZ localization and cell division without preventing continued cell growth. By varying the expression of these proteins, we can tune the lengths of cyanobacterial cells across a broad dynamic range, anywhere from an ∼20% increased length (relative to the wild type) to near-millimeter lengths. Highly elongated cells exhibit increased rates of sedimentation under low centrifugal forces or by gravity-assisted settling. Furthermore, hyperelongated cells are also more susceptible to lysis through the application of mild physical stress. Collectively, these results demonstrate a novel approach toward decreasing harvesting and processing costs associated with mass cyanobacterial cultivation by altering morphology at the cellular level. IMPORTANCE We show that the cell length of a model cyanobacterial species can be programmed by rationally manipulating the expression of protein factors that suppress cell division. In some instances, we can increase the size of these cells to near-millimeter lengths with this approach. The resulting elongated cells have favorable properties with regard to cell harvesting and lysis. Furthermore, cells treated in this manner continue to grow rapidly at time scales similar to those of uninduced controls. To our knowledge, this is the first reported example of engineering the cell morphology of cyanobacteria or algae to make them more compatible with downstream processing steps that present economic barriers to their use as alternative crop species. Therefore, our results are a promising proof-of-principle for the use of morphology engineering to increase the cost-effectiveness of the mass cultivation of cyanobacteria for various sustainability initiatives.

scholarly journals Five Closed Salmonella enterica Genome Sequences from a 2017–2018 Multistrain, Multistate Kratom Outbreak

2020 ◽  
Vol 9 (3) ◽  
Author(s):  
Hallie E. Rauch ◽  
Julie Haendiges ◽  
Maria Balkey ◽  
Maria Hoffmann
Keyword(s):  
Dna Sequencing ◽  
Real Time ◽  
Single Molecule ◽  
Salmonella Enterica ◽  
Genome Sequences ◽  
Circular Chromosome ◽  
Content Type ◽  
Single Plasmid

We report here the closed genomes of Salmonella enterica strains from the 2017–2018 multistrain, multistate kratom outbreak using single-molecule real-time DNA sequencing. Four of the genomes consist of one circular chromosome, and the fifth has a circular chromosome and a single plasmid.

An RFID and sensor technology-based warehouse center: assessment of new model on a superstore in China

2019 ◽  
Vol 39 (1) ◽  
pp. 86-100 ◽  
Author(s):  
Hao Liu ◽  
Zhong Yao ◽  
Li Zeng ◽  
Jing Luan
Keyword(s):  
Radio Frequency Identification ◽  
Operations Management ◽  
Large Scale ◽  
Rapid Development ◽  
Management Mode ◽  
Sensor Technology ◽  
Warehouse Management ◽  
Content Type ◽  
Management Level ◽  
Existing Problems

Purpose Large supermarkets, chain stores and enterprises with large-scale warehousing put forward higher standards and requirements for the automation and informatization of warehouses. As one of the fast-growing commercial supermarkets in China, the traditional warehouse management mode has restricted the rapid development of Yonghui Superstores to a certain extent. The purpose of this paper is to find out how the existing warehouse mode can be changed and to solve the existing problems of warehouse management of Yonghui Superstores. Design/methodology/approach This research puts forward construction of warehouse center, which is based on radio frequency identification (RFID) and sensor technology, then designs the model for receiving, storage, operations management, distribution and outbound to solve the existing problems of warehouse management of Yonghui Superstores. Findings What technologies should be adopted to meet storage requirements? How to monitor the storage environment in real time and improve the operation and management level of the warehouse? This study found that building a warehouse center based on RFID and sensor technology was a good solution. Research limitations/implications The Yonghui Superstores warehouse center model lacks corresponding simulation experiments, and the investment and income are difficult to estimate quantitatively. Practical implications This paper has designed and discussed the warehouse center model based on RFID and sensor technology, which provides a few references for the actual investment and construction of a warehouse center. In addition, the warehouse center model has strong generalized applicability and could be widely used in various enterprises. Social implications The warehouse center could improve the warehouse management level of Yonghui Superstores and change the traditional warehouse management mode. To some extent, it improves the enterprise flexibility of the market, which will be of great significance to improve business efficiency and enhance brand image and competitiveness. Originality/value This study takes Yonghui Superstores as a case to analyze the problems of warehousing management in detail and then designs a warehouse center based on RFID and sensor technology. The study discusses the location and distribution, software and hardware selection, benefits evaluation, significances and return on investment, which makes the warehouse center model versatile, technically feasible and economically applicable.

scholarly journals Sensors for Positron Emission Tomography Applications

Sensors ◽  
2019 ◽  
Vol 19 (22) ◽  
pp. 5019 ◽  
Author(s):  
Jiang ◽  
Chalich ◽  
Deen
Keyword(s):  
Positron Emission Tomography ◽  
Performance Metrics ◽  
Biological Activities ◽  
Low Noise ◽  
Emission Tomography ◽  
Sensor Technology ◽  
Limiting Factor ◽  
Operating Voltage ◽  
Positron Emission ◽  
Czt Detectors

Positron emission tomography (PET) imaging is an essential tool in clinical applications for the diagnosis of diseases due to its ability to acquire functional images to help differentiate between metabolic and biological activities at the molecular level. One key limiting factor in the development of efficient and accurate PET systems is the sensor technology in the PET detector. There are generally four types of sensor technologies employed: photomultiplier tubes (PMTs), avalanche photodiodes (APDs), silicon photomultipliers (SiPMs), and cadmium zinc telluride (CZT) detectors. PMTs were widely used for PET applications in the early days due to their excellent performance metrics of high gain, low noise, and fast timing. However, the fragility and bulkiness of the PMT glass tubes, high operating voltage, and sensitivity to magnetic fields ultimately limit this technology for future cost-effective and multi-modal systems. As a result, solid-state photodetectors like the APD, SiPM, and CZT detectors, and their applications for PET systems, have attracted lots of research interest, especially owing to the continual advancements in the semiconductor fabrication process. In this review, we study and discuss the operating principles, key performance parameters, and PET applications for each type of sensor technology with an emphasis on SiPM and CZT detectors—the two most promising types of sensors for future PET systems. We also present the sensor technologies used in commercially available state-of-the-art PET systems. Finally, the strengths and weaknesses of these four types of sensors are compared and the research challenges of SiPM and CZT detectors are discussed and summarized.

System development toward effective maintenance management practices

2014 ◽  
Vol 4 (4) ◽  
pp. 406-422 ◽  
Author(s):  
Zul-Atfi Ismail
Keyword(s):  
Service Delivery ◽  
Conventional Method ◽  
Process Model ◽  
Management Practices ◽  
System Development ◽  
Facility Management ◽  
Maintenance Management ◽  
Sensor Technology ◽  
Maintenance Planning ◽  
Content Type

Purpose – The current maintenance management method has affected the efficiency of the building facility management at Polytechnics. Many issues such as poor service delivery, inadequate finance, poor maintenance planning and maintenance backlogs have emerged due to the usage of conventional method application (paper-based form and unsystematic database). Therefore, the proposed system improvement is intended to be used for maintenance management practices at Malaysian Polytechnics in order to provide high quality of building facility with safe and healthy environments. The paper aims to discuss these issues. Design/methodology/approach – Eight Polytechnics were selected based on major problems of using conventional method in the comparison to investigate the maintenance management practices in each Polytechnic. Findings – The overall findings of this research indicated; poor service delivery, inadequate financial, poor maintenance planning and maintenance backlogs. The system architecture and the conceptual process model are presented to integrate the information database and maintenance management processes in improving the building diagnosis approach and decision-making process for managing building maintenance. Originality/value – This new system development provides a better maintenance assessment for identifying symptoms, causes and reasons of building defects without depending on the expensive instruments, for instance, non-destructive testing (NDT) and sensor technology. It also has the potential to become the successful technology in assisting the maintenance contractors, clients and developer for effective management of maintenance defects at Polytechnic.

scholarly journals F Plasmids Are the Major Carriers of Antibiotic Resistance Genes in Human-Associated Commensal Escherichia coli

mSphere ◽  
2020 ◽  
Vol 5 (4) ◽  
Author(s):  
Craig Stephens ◽  
Tyler Arismendi ◽  
Megan Wright ◽  
Austin Hartman ◽  
Andres Gonzalez ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Transposable Elements ◽  
Dna Sequencing ◽  
Resistance Genes ◽  
Bacterial Pathogens ◽  
Acquired Resistance ◽  
Antibiotic Resistance Genes ◽  
Content Type ◽  
E Coli

ABSTRACT The evolution and propagation of antibiotic resistance by bacterial pathogens are significant threats to global public health. Contemporary DNA sequencing tools were applied here to gain insight into carriage of antibiotic resistance genes in Escherichia coli, a ubiquitous commensal bacterium in the gut microbiome in humans and many animals, and a common pathogen. Draft genome sequences generated for a collection of 101 E. coli strains isolated from healthy undergraduate students showed that horizontally acquired antibiotic resistance genes accounted for most resistance phenotypes, the primary exception being resistance to quinolones due to chromosomal mutations. A subset of 29 diverse isolates carrying acquired resistance genes and 21 control isolates lacking such genes were further subjected to long-read DNA sequencing to enable complete or nearly complete genome assembly. Acquired resistance genes primarily resided on F plasmids (101/153 [67%]), with smaller numbers on chromosomes (30/153 [20%]), IncI complex plasmids (15/153 [10%]), and small mobilizable plasmids (5/153 [3%]). Nearly all resistance genes were found in the context of known transposable elements. Very few structurally conserved plasmids with antibiotic resistance genes were identified, with the exception of an ∼90-kb F plasmid in sequence type 1193 (ST1193) isolates that appears to serve as a platform for resistance genes and may have virulence-related functions as well. Carriage of antibiotic resistance genes on transposable elements and mobile plasmids in commensal E. coli renders the resistome highly dynamic. IMPORTANCE Rising antibiotic resistance in human-associated bacterial pathogens is a serious threat to our ability to treat many infectious diseases. It is critical to understand how acquired resistance genes move in and through bacteria associated with humans, particularly for species such as Escherichia coli that are very common in the human gut but can also be dangerous pathogens. This work combined two distinct DNA sequencing approaches to allow us to explore the genomes of E. coli from college students to show that the antibiotic resistance genes these bacteria have acquired are usually carried on a specific type of plasmid that is naturally transferrable to other E. coli, and likely to other related bacteria.

scholarly journals Increasedpfmdr1Copy Number and Sequence Polymorphisms in Plasmodium falciparum Isolates from Sudanese Malaria Patients Treated with Artemether-Lumefantrine

2011 ◽  
Vol 55 (11) ◽  
pp. 5408-5411 ◽  
Author(s):  
Nahla B. Gadalla ◽  
Ishag Adam ◽  
Salah-Eldin Elzaki ◽  
Sahar Bashir ◽  
Izdihar Mukhtar ◽  
...  
Keyword(s):  
Plasmodium Falciparum ◽  
Molecular Markers ◽  
Dna Sequencing ◽  
Gene Amplification ◽  
Recurrent Infection ◽  
Efficacy Study ◽  
Content Type ◽  
Sequence Polymorphisms ◽  
Eastern Sudan

ABSTRACTMolecular markers for surveillance ofPlasmodium falciparumresistance to current antimalarials are sorely needed. A 28-day efficacy study of artemether-lumefantrine in eastern Sudan identified 5 treatment failures among 100 evaluable patients; 9 further individuals were parasite positive by PCR during follow-up. Polymorphisms inpfatpase6andpfmdr1were evaluated by DNA sequencing. One individual carried parasites with a novelpfmdr1polymorphism (F1044L).pfmdr1gene amplification in parasites prior to treatment occurred in three individuals who had recurrent infection during follow-up.

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