Low-Cost Thermal Shield for Rapid Diagnostic Tests Using Phase Change Materials

2018 ◽  
Vol 12 (1) ◽  
Author(s):  
Luis R. Soenksen ◽  
David A. Martínez-Corona ◽  
Sofía Iñiguez de Gante ◽  
Pierre S. Phabmixay ◽  
Mauricio J. Marongiu Maggi
Keyword(s):  
Phase Change ◽  
Diagnostic Tests ◽  
Phase Change Materials ◽  
Point Of Care ◽  
Low Cost ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
Cold Chain ◽  
Thermal Shield ◽  
Tropical Regions

The shelf life of point-of-care and rapid diagnostic tests (POC-RDTs) is commonly compromised by abrupt temperature changes during storage, transportation, and use. This situation is especially relevant in tropical regions and resource-constrained settings where cold chain may be unreliable. Here, we report the use of novel and low-cost passive thermal shield (TS) made from laminated phase change material (PCM) to reduce thermal overload in POC-RDTs. Validation of the proposed design was done through numerical simulation and testing of an octadecane shield prototype in contact with a lateral flow immunoassay. The use of our TS design provided 30–45 min delay in thermal equilibration under constant and oscillating heat load challenges resembling those of field use. The addition of a thin PCM protection layer to POC-RDTs can be a cost-effective, scalable, and reliable solution to provide additional thermal stability to these devices.

Performance of rapid diagnostic tests for HCV infection in serum or plasma

2021 ◽  
Author(s):  
Stéphane Chevaliez ◽  
Françoise Roudot-Thoraval ◽  
Christophe Hézode ◽  
Jean-Michel Pawlotsky ◽  
Richard Njouom
Keyword(s):  
Hepatitis C ◽  
Diagnostic Tests ◽  
Large Scale ◽  
Low Cost ◽  
Antibody Test ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
Treatment Programs ◽  
Clinical Sensitivity ◽  
Cost Treatment

Aim: HCV diagnosis will become the bottleneck in eliminating hepatitis C. Simple, accurate and cost-effective testing strategies are urgently needed to improve hepatitis C screening and diagnosis. Materials & methods: Performance of seven rapid diagnostic tests (RDT) have been assessed in a large series (n = 498) of serum or plasma specimens collected in France and in Cameroon. Results: Specificity varied from 96.1 to 100%. The clinical sensitivity, compared with immunoassays as the reference, was high for all seven RDT (97.2–100%). The Multisure HCV antibody assay and OraQuick HCV rapid antibody test reached sensitivity ≥99%. Conclusion: A number of RDT may be suitable for WHO prequalification and may be implemented in the framework of large-scale low-cost treatment programs to achieve the WHO viral hepatitis objectives by 2030.

scholarly journals Economic considerations support C-reactive protein testing alongside malaria rapid diagnostic tests to guide antimicrobial therapy for patients with febrile illness in settings with low malaria endemicity

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Yoel Lubell ◽  
Arjun Chandna ◽  
Frank Smithuis ◽  
Lisa White ◽  
Heiman F. L. Wertheim ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Antimicrobial Therapy ◽  
Diagnostic Tests ◽  
Distribution Systems ◽  
Point Of Care ◽  
Febrile Illness ◽  
Cost Effective ◽  
Rapid Diagnostic Tests ◽  
C Reactive Protein ◽  
Reactive Protein

AbstractMalaria is no longer a common cause of febrile illness in many regions of the tropics. In part, this success is a result of improved access to accurate diagnosis and effective anti-malarial treatment, including in many hard-to-reach rural areas. However, in these settings, management of other causes of febrile illness remains challenging. Health systems are often weak and other than malaria rapid tests no other diagnostics are available. With millions of deaths occurring annually due to treatable bacterial infections and the ever increasing spread of antimicrobial resistance, improvement in the management of febrile illness is a global public health priority. Whilst numerous promising point-of-care diagnostics are in the pipeline, substantial progress can be made in the interim with existing tools: C-reactive protein (CRP) is a highly sensitive and moderately specific biomarker of bacterial infection and has been in clinical use for these purposes for decades, with dozens of low-cost devices commercially available. This paper takes a health-economics approach to consider the possible advantages of CRP point-of-care tests alongside rapid diagnostic tests for malaria, potentially in a single multiplex device, to guide antimicrobial therapy for patients with febrile illness. Three rudimentary assessments of the costs and benefits of this approach all indicate that this is likely to be cost-effective when considering the incremental costs of the CRP tests as compared with either (i) the improved health outcomes for patients with bacterial illnesses; (ii) the costs of antimicrobial resistance averted; or (iii) the economic benefits of better management of remaining malaria cases and shorter malaria elimination campaigns in areas of low transmission. While CRP-guided antibiotic therapy alone cannot resolve all challenges associated with management of febrile illness in remote tropical settings, in the short-term a multiplexed CRP and malaria RDT could be highly cost-effective and utilize the well-established funding and distribution systems already in place for malaria RDTs. These findings should spark further interest amongst industry, academics and policy-makers in the development and deployment of such diagnostics, and discussion on their geographically appropriate use.

scholarly journals Encapsulation of Phase Change Materials Using Layer-by-Layer Assembled Polyelectrolytes

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Qiangying Yi ◽  
Gleb B. Sukhorokov ◽  
Jin Ma ◽  
Xiaobo Yang ◽  
Zhongwei Gu
Keyword(s):  
Phase Change ◽  
Phase Change Materials ◽  
Low Cost ◽  
Sodium Dodecyl ◽  
Layer By Layer ◽  
Latent Heat Storage ◽  
Good Thermal Stability ◽  
Lbl Assembly ◽  
Acid Sodium Salt ◽  
Assembly Technique

Phase change materials absorb the thermal energy when changing their phases (e.g., solid-to-liquid) at constant temperatures to achieve the latent heat storage. The major drawbacks such as limited thermal conductivity and leakage prevent the PCMs from wide application in desired areas. In this work, an environmentally friendly and low cost approach, layer-by-layer (LbL) assembly technique, was applied to build up ultrathin shells to encapsulate the PCMs and therefore to regulate their changes in volume when the phase change occurs. Generally, the oppositely charged strong polyelectrolytes Poly(diallyldimethylammonium chloride) (PDADMAC) and Poly(4-styrenesulfonic acid) sodium salt (PSS) were employed to fabricate multilayer shells on emulsified octadecane droplets using either bovine serum albumin (BSA) or sodium dodecyl sulfate (SDS) as surfactant. Specifically, using BSA as the surfactant, polyelectrolyte encapsulated octadecane spheres in size of ∼500 nm were obtained, with good shell integrity, high octadecane content (91.3% by mass), and good thermal stability after cycles of thermal treatments.

scholarly journals Experimental Characterization of Phase Change Materials for Refrigeration Processes

Energies ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3033
Author(s):  
Anastasia Stamatiou ◽  
Lukas Müller ◽  
Roger Zimmermann ◽  
Jamie Hillis ◽  
David Oliver ◽  
...  
Keyword(s):  
Energy Density ◽  
Phase Change ◽  
Thermophysical Properties ◽  
Phase Change Materials ◽  
Cost Effective ◽  
Latent Heat Storage ◽  
Lower Energy Density ◽  
Change Material ◽  
Storage Units

Latent heat storage units for refrigeration processes are promising as alternatives to water/glycol-based storage due to their significantly higher energy densities, which would lead to more compact and potentially more cost-effective storages. In this study, important thermophysical properties of five phase change material (PCM) candidates are determined in the temperature range between −22 and −35 °C and their compatibility with relevant metals and polymers is investigated. The goal is to complement existing scattered information in literature and to apply a consistent testing methodology to all PCMs, to enable a more reliable comparison between them. More specifically, the enthalpy of fusion, melting point, density, compatibility with aluminum, copper, polyethylene (PE), polypropylene (PP), neoprene and butyl rubber, are experimentally determined for 1-heptanol, n-decane, propionic acid, NaCl/water mixtures, and Al(NO3)3/water mixtures. The results of the investigations reveal individual strengths and weaknesses of the five candidates. Further, 23.3 wt.% NaCl in water stands out for its very high volumetric energy density and n-decane follows with a lower energy density but better compatibility with surrounding materials and supercooling performance. The importance of using consistent methodologies to determine thermophysical properties when the goal is to compare PCM performance is highlighted.

Performance evaluation and design considerations for a split air-conditioner with built-in thermal energy storage

2018 ◽  
Vol 40 (5) ◽  
pp. 560-575
Author(s):  
Jehanzeb Ahmad ◽  
M Najam Ul Islam ◽  
Jawwad Sabir
Keyword(s):  
Energy Storage ◽  
Phase Change ◽  
Thermal Energy ◽  
Thermal Energy Storage ◽  
Phase Change Materials ◽  
Low Cost ◽  
Hvac Systems ◽  
Air Conditioner ◽  
Widespread Application ◽  
Air Conditioners

The benefits of thermal energy storage using phase change materials are well documented in the literature. Despite all the potential benefits of thermal energy storage, its commercial and widespread application remains limited. This is due to the high initial cost of phase change materials, extensive rework required in buildings, major modifications in HVAC systems, and the potential for leakage, fire and toxicity hazards. There is a strong need for a simple thermal energy storage solution which can be adopted by large number of consumers. Ductless split air-conditioners are portable, low cost, efficient and account for 70% of all air-conditioning systems sold worldwide each year. The present research provides a novel and low cost solution that incorporates thermal energy storage in these air conditioners, allowing them to run without electricity for 3 h. The paper deals with the detailed design aspects and engineering challenges that arise when incorporating thermal energy storage in these small units. A prototype air-conditioner with in-built thermal energy storage was developed, and all performance parameters presented have been validated through data obtained from the prototype. Our results indicate that thermal energy storage can be incorporated in split units in low cost and with minimal drop in overall energy efficiency of the system. Practical application: Incorporating thermal energy storage in split air-conditioners which enables them to run without grid for many hours has immense practical applications. Since around 50% power in any building is consumed by HVAC systems, being able to provide cooling during peak hours without using grid can significantly reduce load on the grid without compromising user comfort. For developing countries where load shedding is frequent, the users can run these air-conditioners without the use of generators or batteries thus saving costs and the environment.

scholarly journals The Role of Antigen Rapid Diagnostic Test in COVID-19 Diagnosis

2021 ◽  
Vol 1 (1) ◽  
pp. 108-111
Author(s):  
Ronni Mol Joji ◽  
Mohammad Shahid
Keyword(s):  
Diagnostic Tests ◽  
Point Of Care ◽  
Rapid Diagnostic Tests ◽  
World Health ◽  
Complementary Role ◽  
Reverse Transcription Quantitative Pcr ◽  
Highly Sensitive ◽  
Health Organization ◽  
Random Screening

Since the emergence of a novel infection due to the SARS-CoV-2 virus (COVID-19), the World Health Organization has urged countries to develop diagnostic tests to combat the pandemic. Molecular assays were developed following the release of the gene sequence of the virus in January 2020. Reverse transcription-quantitative PCR (RT-qPCR) is taken as the gold standard for the diagnosis of COVID-19. However, due to its limitations, highly sensitive methods for detecting antigens (antigen rapid diagnostic tests) have been developed that would help in a timely and accurate diagnosis. Antigen rapid diagnostic tests (Ag-RDTs) can help guide patient management at the point of care by random screening, re-testing, and timely decision-making in the field of public health. When the affordability and validity of the diagnostic assay are involved, no assay can show 100% correct results. Further studies need to be done to better understand the response of the Ag-RDTs in different settings. Nevertheless, Ag-RDTs can play a complementary role in the response and case management of COVID-19.

scholarly journals Thermal Performance of Resource-Efficient Geopolymeric Mortars Containing Phase Change Materials

2018 ◽  
Vol 12 (1) ◽  
pp. 217-233
Author(s):  
M. Kheradmand ◽  
F. Pacheco-Torgal ◽  
M. Azenha
Keyword(s):  
Phase Change ◽  
Thermal Performance ◽  
Phase Change Materials ◽  
Positive Impact ◽  
Performance Testing ◽  
Cost Effective ◽  
Small Scale ◽  
Heating And Cooling ◽  
Reduce Emissions ◽  
Cooling Loads

Background:Energy efficiency is not only the most cost effective way to reduce emissions but also a way to improve competitiveness and create employment. Geopolymeric mortars containing phase change materials-PCMs have a twofold positive impact concerning eco-efficiency. On one hand, the mortars are based on industrial waste contributing for resource efficiency. And on the other hand, PCM based mortars have the capacity to enhance the thermal performance of the buildings.Objective:This paper reports experimental results on the thermal performance of geopolymeric mortars containing different percentages of phase-change materials-PCMs.Method:Five groups of alkali-activated based mortars with different PCM percentages were produced and placed on a panel within a small scale prototype for thermal performance testing.Results:The results show that the thermal conductivity of the mortars decreased with the increase in the percentage of the PCM.Conclusion:Thermal performance of the PCM based mortars allowed for a stronger attenuation of the temperature amplitudes. Both for heating and cooling loads.

scholarly journals Review of Solutions for the Use of Phase Change Materials in Geopolymers

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6044
Author(s):  
Michał Łach ◽  
Kinga Pławecka ◽  
Agnieszka Bąk ◽  
Marcin Adamczyk ◽  
Patrycja Bazan ◽  
...  
Keyword(s):  
Phase Change ◽  
Building Materials ◽  
Phase Change Materials ◽  
Matrix Material ◽  
Cost Effective ◽  
Mass Scale ◽  
Sustainable Construction ◽  
Thermal Gradients ◽  
Effective Form ◽  
The Matrix

The paper deals with the possibility of using Phase Change Materials (PCM) in concretes and geopolymer composites. The article presents the most important properties of PCM materials, their types, and their characteristics. A review of the latest research results related to their use in geopolymer materials is presented. The benefits of using PCM in building materials include the improvement of thermal comfort inside the building, and also the fact that the additive in the form of PCM reduces thermal gradients and unifies the temperature inside the concrete mix, which can reduce the risk of cracking. The paper also presents a critical analysis related to the feasibility of mass scale implementations of such composites. It was found that the use of PCM in sustainable construction is necessary and inevitable, and will bring a number of benefits, but it still requires large financial resources and time for more comprehensive research. Despite the fact that PCM materials have been known for many years, it is necessary to refine their form to very stable phases that can be used in general construction as well as to develop them in a cost-effective form. The selection of these materials should also be based on the knowledge of the matrix material.

scholarly journals Clinical impact of the rapid molecular detection of RSV and influenza A and B virus in the emergency room

2021 ◽  
Author(s):  
Nicolas Yin ◽  
Marc Van Nuffelen ◽  
Magali Bartiaux ◽  
Thierry Preseau ◽  
Inge Roggen ◽  
...  
Keyword(s):  
Emergency Room ◽  
Clinical Management ◽  
Diagnostic Tests ◽  
Influenza A ◽  
Point Of Care ◽  
Antibiotic Use ◽  
Rapid Diagnostic Tests ◽  
Analytical Performance ◽  
Molecular Test ◽  
The Impact

Introduction: Using respiratory viruses' rapid diagnostic tests in the emergency room (ER) could allow a better and faster clinical management. Point-of-care PCR instruments provide now results in less than 30 minutes. The objective of this study was to assess the impact of the use of the cobas® Influenza A/B & RSV Assay for use on Roche's cobas® Liat® instrument on the clinical management of ER patients. Methods: Patients (adults and children) requiring admission or suffering from an underlying condition at risk of respiratory complication were prospectively recruited in the ER of four hospitals in the Brussels region. Physician's intentions regarding admission, isolation, antibiotic and antiviral use were collected before and after performing a cobas® Influenza A/B & RSV molecular test. Additionally, a comparison of the analytical performance of this test against antigen rapid tests and viral culture was performed as well as a time-to-result evaluation. Results: PCR yielded twice more positive results than antigen rapid diagnostic tests. It allowed a decrease in the overall need for isolation and treatment by limiting the isolation of negative patients and the antibiotic use for positive patients. Meanwhile, antiviral treatments better targeted patients with a positive influenza PCR. Conclusion: The use of a rapid influenza and RSV molecular test improves the clinical management of patients admitted to the ER by providing a fast and reliable result. Their additional cost compared to antigen tests should be balanced with the benefit of their analytical performance, leading to efficient reductions in the need of isolation and antibiotic use.

Sign in / Sign up

Export Citation Format

Share Document