An Interface–Particle Interaction Approach for Evaluation of the Co-Encapsulation Efficiency of Cells in a Flow-Focusing Droplet Generator

Droplet-based microfluidics offers significant advantages, such as high throughput and scalability, making platforms based on this technology ideal candidates for point-of-care (POC) testing and clinical diagnosis. However, the efficiency of co-encapsulation in droplets is suboptimal, limiting the applicability of such platforms for the biosensing applications. The homogeneity of the bioanalytes in the droplets is an unsolved problem. While there is extensive literature on the experimental setups and active methods used to increase the efficiency of such platforms, passive techniques have received less attention, and their fundamentals have not been fully explored. Here, we develop a novel passive technique for investigating cell encapsulation using the finite element method (FEM). The level set method was used to track the interfaces of forming droplets. The effects of walls and the droplet interfaces on relatively large cells were calculated to track them more accurately during encapsulation. The static surface tension force was used to account for the effects of the interfaces on cells. The results revealed that the pairing efficiency is highly sensitive to the standard deviation (SD) of the distance between the cells in the entrance channel. The pairing efficiency prediction error of our model differed by less than 5% from previous experiments. The proposed model can be used to evaluate the performance of droplet-based microfluidic devices to ensure higher precision for co-encapsulation of cells.

Download Full-text

A Circular Business Model for Cloud Computing Services Providers

International Journal of Community Development and Management Studies ◽

10.31355/33 ◽

2018 ◽

Vol 2 ◽

pp. 105-120

Author(s):

Hamed Motaghi ◽

Saeed Nosratabadi ◽

Thabit Qasem Atobishi

Keyword(s):

Cloud Computing ◽

Business Model ◽

Circular Economy ◽

Service Providers ◽

Sustainable Consumption ◽

Future Research ◽

Extensive Literature ◽

Computing Services ◽

Proposed Model ◽

Cloud Computing Service

NOTE: THIS ARTICLE WAS PUBLISHED WITH THE INFORMING SCIENCE INSTITUTE. Aim/Purpose................................................................................................................................................................................................. The main objective of the current study is to develop a business model for service providers of cloud computing which is designed based on circular economy principles and can ensure the sustainable consumption. Background Even though the demand for cloud computing technology is increasing day by day in all over the world, the current the linear economy principles are incapable to ensure society development needs. To consider the benefit of the society and the vendors at the same time, the principles of circular economy can address this issue. Methodology................................................................................................................................................................................................. An extensive literature review on consumption, sustainable consumption, circular economic, business model, and cloud computing were conducted. the proposed model of Osterwalder, Pigneur and Tucci (2005) is admitted designing the circular business model. Contribution................................................................................................................................................................................................. The proposed model of the study is the contribution of this study where provides the guidelines for the cloud computing service providers to achieve both their economic profits and the society’ needs. Findings Finding reveals that if the cloud computing service providers design their business model based on the “access” principle of circular economy, they can meet their economic profits and the society’ needs at a same time. Recommendations for Practitioners.............................................................................................................................................................. It is recommended to the startup and the existing businesses to utilize the proposed model of this study to reach a sustainable development. Recommendation for Researchers................................................................................................................................................................ It proposes a new circular business model and its linkages with community building. Impact on Society............................................................................................................................................................................................ The proposed model of the study provides guidelines to the cloud computing service providers to design a business model which is able not only to meet their economic profit, but also to meet the society’s and customers’ benefits. Future Research............................................................................................................................................................................................... Future researches can build on this research model which proposed in this study to examine the limitations of this model by using empirical researches.

Download Full-text

LAMP-based foldable microdevice platform for the rapid detection of Magnaporthe oryzae and Sarocladium oryzae in rice seed

Scientific Reports ◽

10.1038/s41598-020-80644-z ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

M. K. Prasannakumar ◽

P. Buela Parivallal ◽

Devanna Pramesh ◽

H. B. Mahesh ◽

Edwin Raj

Keyword(s):

Magnaporthe Oryzae ◽

Plant Pathogens ◽

Point Of Care ◽

Lamp Assay ◽

Rice Seed ◽

Highly Sensitive ◽

Polymerase Chain ◽

Rice Seeds ◽

Template Dna ◽

Assay Conditions

AbstractRice blast (caused by Magnaporthe oryzae) and sheath rot diseases (caused by Sarocladium oryzae) are the most predominant seed-borne pathogens of rice. The detection of both pathogens in rice seed is essential to avoid production losses. In the present study, a microdevice platform was designed, which works on the principles of loop-mediated isothermal amplification (LAMP) to detect M. oryzae and S. oryzae in rice seeds. Initially, a LAMP, polymerase chain reaction (PCR), quantitative PCR (qPCR), and helicase dependent amplification (HDA) assays were developed with primers, specifically targeting M. oryzae and S. oryzae genome. The LAMP assay was highly efficient and could detect the presence of M. oryzae and S. oryzae genome at a concentration down to 100 fg within 20 min at 60 °C. Further, the sensitivity of the LAMP, HDA, PCR, and qPCR assays were compared wherein; the LAMP assay was highly sensitive up to 100 fg of template DNA. Using the optimized LAMP assay conditions, a portable foldable microdevice platform was developed to detect M. oryzae and S. oryzae in rice seeds. The foldable microdevice assay was similar to that of conventional LAMP assay with respect to its sensitivity (up to 100 fg), rapidity (30 min), and specificity. This platform could serve as a prototype for developing on-field diagnostic kits to be used at the point of care centers for the rapid diagnosis of M. oryzae and S. oryzae in rice seeds. This is the first study to report a LAMP-based foldable microdevice platform to detect any plant pathogens.

Download Full-text

Smartphone Based Highly Sensitive Visualized Detection of Acid Phosphatase Enzyme Activity

Analytical Methods ◽

10.1039/d0ay02128h ◽

2021 ◽

Author(s):

Rui Li ◽

Yanan Sun ◽

Lihua Jin ◽

Xiaohong Qiao ◽

Cong Li ◽

...

Keyword(s):

Enzyme Activity ◽

Acid Phosphatase ◽

Point Of Care ◽

Rapid Development ◽

Practical Application ◽

Fast Analysis ◽

Highly Sensitive ◽

Visualized Detection ◽

Sensitive Method ◽

Phosphatase Enzyme

With the rapid development of point-of-care (POC) technologies, the improvement of sensitive method featured with fast analysis and affordable devices has become an emerging requirement for the practical application. In...

Download Full-text

Evaluation of mobile real-time polymerase chain reaction tests for the detection of severe acute respiratory syndrome coronavirus 2

Scientific Reports ◽

10.1038/s41598-021-88625-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Chukwunonso Onyilagha ◽

Henna Mistry ◽

Peter Marszal ◽

Mathieu Pinette ◽

Darwyn Kobasa ◽

...

Keyword(s):

Severe Acute Respiratory Syndrome ◽

Real Time ◽

Point Of Care ◽

Middle Eastern ◽

Turnaround Time ◽

Cross Reactivity ◽

Clinical Samples ◽

Diarrhea Virus ◽

Highly Sensitive ◽

Transmissible Gastroenteritis

AbstractThe coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), calls for prompt and accurate diagnosis and rapid turnaround time for test results to limit transmission. Here, we evaluated two independent molecular assays, the Biomeme SARS-CoV-2 test, and the Precision Biomonitoring TripleLock SARS-CoV-2 test on a field-deployable point-of-care real-time PCR instrument, Franklin three9, in combination with Biomeme M1 Sample Prep Cartridge Kit for RNA 2.0 (M1) manual extraction system for rapid, specific, and sensitive detection of SARS-COV-2 in cell culture, human, and animal clinical samples. The Biomeme SARS-CoV-2 assay, which simultaneously detects two viral targets, the orf1ab and S genes, and the Precision Biomonitoring TripleLock SARS-CoV-2 assay that targets the 5′ untranslated region (5′ UTR) and the envelope (E) gene of SARS-CoV-2 were highly sensitive and detected as low as 15 SARS-CoV-2 genome copies per reaction. In addition, the two assays were specific and showed no cross-reactivity with Middle Eastern respiratory syndrome coronavirus (MERS-CoV), infectious bronchitis virus (IBV), porcine epidemic diarrhea virus (PEDV), transmissible gastroenteritis (TGE) virus, and other common human respiratory viruses and bacterial pathogens. Also, both assays were highly reproducible across different operators and instruments. When used to test animal samples, both assays equally detected SARS-CoV-2 genetic materials in the swabs from SARS-CoV-2-infected hamsters. The M1 lysis buffer completely inactivated SARS-CoV-2 within 10 min at room temperature enabling safe handling of clinical samples. Collectively, these results show that the Biomeme and Precision Biomonitoring TripleLock SARS-CoV-2 mobile testing platforms could reliably and promptly detect SARS-CoV-2 in both human and animal clinical samples in approximately an hour and can be used in remote areas or health care settings not traditionally serviced by a microbiology laboratory.

Download Full-text

A Thermal Model for Three-Core Armored Submarine Cables Based on Distributed Temperature Sensing

Energies ◽

10.3390/en14133897 ◽

2021 ◽

Vol 14 (13) ◽

pp. 3897

Author(s):

Miguel Ángel González-Cagigal ◽

Juan Carlos del-Pino-López ◽

Alfonso Bachiller-Soler ◽

Pedro Cruz-Romero ◽

José Antonio Rosendo-Macías

Keyword(s):

Temperature Sensing ◽

The Finite Element Method ◽

Current Profile ◽

Distributed Temperature Sensing ◽

Numerical Resolution ◽

Electromagnetic Model ◽

Proposed Model ◽

Relative Errors ◽

Dynamic Loading Conditions ◽

Submarine Cables

This paper presents a procedure for the derivation of an equivalent thermal network-based model applied to three-core armored submarine cables. The heat losses of the different metallic cable parts are represented as a function of the corresponding temperatures and the conductor current, using a curve-fitting technique. The model was applied to two cables with different filler designs, supposed to be equipped with distributed temperature sensing (DTS) and the optical fiber location in the equivalent circuit was adjusted so that the conductor temperature could be accurately estimated using the sensor measurements. The accuracy of the proposed model was tested for both stationary and dynamic loading conditions, with the corresponding simulations carried out using a hybrid 2D-thermal/3D-electromagnetic model and the finite element method for the numerical resolution. Mean relative errors between 1 and 3% were obtained using an actual current profile. The presented procedure can be used by cable manufacturers or by utilities to properly evaluate the cable thermal situation.

Download Full-text

A Highly Sensitive, Polarization Maintaining Photonic Crystal Fiber Sensor Operating in the THz Regime

Photonics ◽

10.3390/photonics5040040 ◽

2018 ◽

Vol 5 (4) ◽

pp. 40 ◽

Cited By ~ 7

Author(s):

Sohel Rana ◽

Nirmala Kandadai ◽

Harish Subbaraman

Keyword(s):

Photonic Crystal ◽

Photonic Crystal Fiber ◽

High Sensitivity ◽

Relative Sensitivity ◽

Computational Technique ◽

The Finite Element Method ◽

High Birefringence ◽

Crystal Fiber ◽

Highly Sensitive ◽

Imaging And Spectroscopy

In this paper, a high sensitivity, polarization preserving photonic crystal fiber (PCF), based on circular air holes for sensing in the terahertz (THz) band, is presented. The finite element method, a practical and precise computational technique for describing the interactions between light and matter, is used to compute the modal properties of the designed fiber. For the designed PCF, comprising of circular air holes in both the cladding and in the porous core, a relative sensitivity of 73.5% and a high birefringence of 0.013 are achieved at 1.6 THz. The all circular air-hole structure, owing to its simplicity and compatibility with the current fiber draw technique for PCF fabrication, can be realized practically. It is anticipated that the designed fiber can be employed in applications such as detection of biological samples and toxic chemicals, imaging, and spectroscopy.

Download Full-text

A Novel NiFe2O4/Paper-Based Magnetoelastic Biosensor to Detect Human Serum Albumin

Sensors ◽

10.3390/s20185286 ◽

2020 ◽

Vol 20 (18) ◽

pp. 5286

Author(s):

Xing Guo ◽

Rong Liu ◽

Hongmei Li ◽

Jingzhe Wang ◽

Zhongyun Yuan ◽

...

Keyword(s):

Human Serum Albumin ◽

Serum Albumin ◽

Human Serum ◽

Specific Binding ◽

Point Of Care ◽

Electromagnetic Signal ◽

Portable Detection ◽

Highly Sensitive ◽

Stress Signal ◽

Nife2o4 Nanoparticles

For the first time, a novel NiFe2O4/paper-based magnetoelastic (ME) biosensor was developed for rapid, sensitive, and portable detection of human serum albumin (HSA). Due to the uniquely magnetoelastic effect of NiFe2O4 nanoparticles and the excellent mechanical properties of the paper, the paper-based ME biosensor transforms the surface stress signal induced by the specific binding of HSA and antibody modified on the paper into the electromagnetic signal. The accumulated binding complex generates a compressive stress on the biosensor surface, resulting in a decrease in the biosensor’s static magnetic permeability, which correlates to the HSA concentrations. To improve the sensitivity of the biosensor, the concentration of NiFe2O4 nanofluid and the impregnated numbers of the NiFe2O4 nanofluid-impregnated papers were optimized. The experimental results demonstrated that the biosensor exhibited a linear response to HSA concentrations ranging from 10 μg∙mL−1 to 200 μg∙mL−1, with a detection limit of 0.43 μg∙mL−1, which is significantly lower than the minimal diagnosis limit of microalbuminuria. The NiFe2O4/paper-based ME biosensor is easy to fabricate, and allows the rapid, highly-sensitive, and selective detection of HSA, providing a valuable analytical device for early monitoring and clinical diagnosis of microalbuminuria and nephropathy. This study shows the successful integration of the paper-based biosensor and the ME sensing analytical method will be a highly-sensitive, easy-to-use, disposable, and portable alternative for point-of-care monitoring.

Download Full-text

Modeling bid/no bid decisions using fuzzy fault tree

Construction Innovation ◽

10.1108/ci-11-2016-0060 ◽

2018 ◽

Vol 18 (1) ◽

pp. 90-108 ◽

Cited By ~ 1

Author(s):

Mohamed Marzouk ◽

Emad Mohamed

Keyword(s):

Fault Tree ◽

The Body ◽

Final Decision ◽

Extensive Literature ◽

Willingness To Participate ◽

Tree Model ◽

Content Type ◽

Proposed Model ◽

Multiple Experts ◽

Two Stages

Purpose Decisions by construction contractors to bid (or not to bid) require the thorough assessment and evaluation of factors relevant to the decision, as well as the quantification of their combined impact, to produce successful bid/no-bid decisions. The purpose of this study is to present a fuzzy fault tree model to assist construction contractors to more efficiently bid for future projects. Design/methodology/Approach The proposed model consist of two stages: first, identification of the factors that affect bidding decision using a questionnaire survey after an extensive literature review, and second, usage of the identified factors to build a fuzzy fault tree model to simulate the bidding decision. Findings A list of 15 factors that affect bid/no-bid decisions was identified. Analysis of factors revealed that the highest-ranking factors were related to financial aspects of the project. A case study is presented to demonstrate the capabilities of the model, and a fuzzy important analysis is performed on the basic events to demonstrate the differences between three contractors’ bid/no-bid decisions. The results reveal that there is variation between the decisions of each contractor based on their willingness to participate. Besides, the influence of evaluation factors on the final decision for each contractor is different. Originality/value The study contributes to the body of knowledge on tendering and bidding practices. The proposed model incorporated the fuzzy set theory, which suits human subjectivity. The proposed methodology overcomes the limitations of previous models as it can, using the linear pool opinion principle, combine and weigh the evaluations of multiple experts. In addition, the model is convenient for situations where historical data are not available.

Download Full-text

Point-of-care testing of melamine via gas pressure readout using polythymine-coated Au@Pt nanoparticles through specific triple hydrogen-bonding recognition

The Analyst ◽

10.1039/d1an01153g ◽

2021 ◽

Author(s):

Ling Li ◽

Hanwen Deng ◽

Zhongshuai Zhao ◽

Zhongde Liu

Keyword(s):

Hydrogen Bonding ◽

Point Of Care ◽

Pt Nanoparticles ◽

Gas Pressure ◽

Point Of Care Testing ◽

Highly Sensitive

On the basis of the target-responsive aggregation occurrence of Au@PtNPs, a pressure-based signaling strategy was developed for highly sensitive and specific melamine detection not only in laboratory but also in point-of-care (POC) settings.

Download Full-text

A Model to Assist the Maintenance vs. Replacement Decision in Information Systems

Measuring Organizational Information Systems Success ◽

10.4018/978-1-4666-0170-3.ch008 ◽

2012 ◽

pp. 137-157 ◽

Cited By ~ 2

Author(s):

O. Tolga Pusatli ◽

Brian Regan

Keyword(s):

Information Systems ◽

Software Quality ◽

Decision Makers ◽

Software Quality Assurance ◽

Extensive Literature ◽

Science Literature ◽

Overburden Pressure ◽

Proposed Model ◽

Maintenance Activities ◽

Change Requests

An extensive literature review shows that Information Systems (IS) are changed and eventually replaced by substitutes under the influence of productivity, popularity, and specialisation of IS along with associated available support facilities, maintenance activities, failures, and user feedback. This chapter compiles those factors emerged from software engineering, IS, software quality assurance measurements, and computer science literature. A final product is a proposed model bringing those factors together as they are suspected to raise a need for taking the decision of evaluating change requests that may lead to a further maintenance or replace the IS. While keeping in mind that limitations on advanced testing exist, an expected service of such a model may help decision makers to explain maintenance/replacement decision of IS/component in a more itemized manner, hence diminish overburden pressure of experience responsibility on them.

Download Full-text