27,530 results
Search Results
2. Trends in Paper-Based Sensing Devices for Clinical and Environmental Monitoring
- Author
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Kummari, Shekher, Panicker, Lakshmi R, Bommi, Jagadeeswara Rao, Karingula, Sampath, Kumar, Venisheety Sunil, Mahato, Kuldeep, and Goud, Kotagiri Yugender
- Subjects
Analytical Chemistry ,Chemical Sciences ,Bioengineering ,Detection ,screening and diagnosis ,4.1 Discovery and preclinical testing of markers and technologies ,Paper ,Ecosystem ,Biosensing Techniques ,Environmental Monitoring ,Environmental Pollutants ,Electrochemical Techniques ,biosensors ,clinical diagnostics ,electrochemical sensors ,environmental monitoring ,optical sensors ,paper-based sensing devices ,Biochemistry and Cell Biology ,Biochemistry and cell biology ,Analytical chemistry - Abstract
Environmental toxic pollutants and pathogens that enter the ecosystem are major global issues. Detection of these toxic chemicals/pollutants and the diagnosis of a disease is a first step in efficiently controlling their contamination and spread, respectively. Various analytical techniques are available to detect and determine toxic chemicals/pathogens, including liquid chromatography, HPLC, mass spectroscopy, and enzyme-linked immunosorbent assays. However, these sensing strategies have some drawbacks such as tedious sample pretreatment and preparation, the requirement for skilled technicians, and dependence on large laboratory-based instruments. Alternatively, biosensors, especially paper-based sensors, could be used extensively and are a cost-effective alternative to conventional laboratory testing. They can improve accessibility to testing to identify chemicals and pollutants, especially in developing countries. Due to its low cost, abundance, easy disposal (by incineration, for example) and biocompatible nature, paper is considered a versatile material for the development of environmentally friendly electrochemical/optical (bio) sensor devices. This review presents an overview of sensing platforms constructed from paper, pointing out the main merits and demerits of paper-based sensing systems, their fabrication techniques, and the different optical/electrochemical detection techniques that they exploit.
- Published
- 2023
3. Dynamic Radial Placement and Routing in Paper Microfluidics
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Potter, Joshua, Grover, William H, and Brisk, Philip
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Bioengineering ,Biotechnology ,Layout ,Reservoirs ,Routing ,Physical design ,Substrates ,Geometry ,COVID-19 ,Continuous placement ,paper microfluidics ,placement and routing ,Electrical and Electronic Engineering ,Computer Hardware ,Computer Hardware & Architecture - Abstract
The low cost, simplicity, and ease of use of paper microfluidic devices have made them valuable medical diagnostics for applications from pregnancy testing to COVID-19 screening. Meanwhile, the increasing complexity of paper-based microfluidic devices is driving the need to produce new tools and methodologies that enable more robust biological diagnostics and potential therapeutic applications. A new design framework is being used to facilitate both research and fabrication of paper-based microfluidic biological devices to accelerate the investigative process and reduce material utilization and manpower. In this work we present a methodology for this framework to dynamically place and route microfluidic components in a nondiscrete design space where fluid volume usage, surface area utilization, and the timing required to perform specified biological assays are accounted for and optimized while also accelerating the development of potentially lifesaving new devices.
- Published
- 2021
4. Fluorometric Paper-Based, Loop-Mediated Isothermal Amplification Devices for Quantitative Point-of-Care Detection of Methicillin-Resistant Staphylococcus aureus (MRSA)
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Choopara, Ilada, Suea-Ngam, Akkapol, Teethaisong, Yothin, Howes, Philip D, Schmelcher, Mathias, Leelahavanichkul, Asada, Thunyaharn, Sudaluck, Wongsawaeng, Doonyapong, deMello, Andrew J, Dean, Deborah, and Somboonna, Naraporn
- Subjects
Analytical Chemistry ,Engineering ,Electronics ,Sensors and Digital Hardware ,Chemical Sciences ,Emerging Infectious Diseases ,Antimicrobial Resistance ,Bioengineering ,Infectious Diseases ,Infection ,Good Health and Well Being ,Humans ,Methicillin-Resistant Staphylococcus aureus ,Molecular Diagnostic Techniques ,Nucleic Acid Amplification Techniques ,Point-of-Care Systems ,Sensitivity and Specificity ,molecular diagnostic ,DNA detection ,loop-mediated isothermal amplification ,methicillin-resistant Staphylococcus aureus ,paper-based analytical device ,point-of-care ,quantitative detection ,Biomedical Engineering ,Nanotechnology ,Analytical chemistry ,Electronics ,sensors and digital hardware - Abstract
Loop-mediated isothermal amplification (LAMP) has been widely used to detect many infectious diseases. However, minor inconveniences during the steps of adding reaction ingredients and lack of simple color results hinder point-of-care detection. We therefore invented a fluorometric paper-based LAMP by incorporating LAMP reagents, including a biotinylated primer, onto a cellulose membrane paper, with a simple DNA fluorescent dye incubation that demonstrated rapid and accurate results parallel to quantitative polymerase chain reaction (qPCR) methods. This technology allows for instant paper strip detection of methicillin-resistant Staphylococcus aureus (MRSA) in the laboratory and clinical samples. MRSA represents a major public health problem as it can cause infections in different parts of the human body and yet is resistant to commonly used antibiotics. In this study, we optimized LAMP reaction ingredients and incubation conditions following a central composite design (CCD) that yielded the shortest reaction time with high sensitivity. These CCD components and conditions were used to construct the paper-based LAMP reaction by immobilizing the biotinylated primer and the rest of the LAMP reagents to produce the ready-to-use MRSA diagnostic device. Our paper-based LAMP device could detect as low as 10 ag (equivalent to 1 copy) of the MRSA gene mecA within 36-43 min, was evaluated using both laboratory (individual cultures of MRSA and non-MRSA bacteria) and clinical blood samples to be 100% specific and sensitive compared to qPCR results, and had 35 day stability under 25 °C storage. Furthermore, the color readout allows for quantitation of MRSA copies. Hence, this device is applicable for point-of-care MRSA detection.
- Published
- 2021
5. Rapid Measurement of Residual Kanamycin Using Highly Specific Biomimetic Recognition Paper-Based Chip
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Song, Jian, He, Kaiyu, Xing, Bingcong, Pei, Yong, Wang, Dingnan, Wang, Yang, Li, Shiyan, Li, Jie, Huan, Weiwei, Zhang, Yiming, and Hammock, Bruce D
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Fluid Mechanics and Thermal Engineering ,Engineering ,Chemical Sciences ,Biotechnology ,Bioengineering ,Molecular Imprinting ,Biomimetics ,Kanamycin ,Biomimetic Materials ,Analytical Chemistry ,Other Chemical Sciences ,Medical biochemistry and metabolomics ,Analytical chemistry ,Chemical engineering - Abstract
The development of highly specific biomimetic recognition material is a challenge for rapid detection of harmful residues in foodstuff. In this study, a paper-based boronate affinity metal-organic framework/molecularly imprinted polymer microfluidic chip (FZS-BA@MIP) was constructed based on the in situ construction strategy, which was also designed as a highly specific biomimetic recognition module. Here, the homogeneous zeolitic imidazole framework-8 (ZIF-8) membrane served as a great scaffold and enrichment layer. Besides, the recognition layer of MIP was prepared based on a highly oriented boronate affinity surface imprinting strategy. With the aid of the liquid flow channel, the highly specific enrichment and visual detection for antibiotic residues like kanamycin in actual products were achieved on the paper chip module of an integrated lateral flow platform. The whole analysis process could be accomplished within 30 min. In brief, this study offered a new integrated biomimetic recognition platform for visually detecting harmful veterinary residues containing cis-diols, which demonstrated promising commercial value in point-of-care testing of foodborne hazardous compounds.
- Published
- 2022
6. Distance and Microsphere Aggregation-Based DNA Detection in a Paper-Based Microfluidic Device
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Kalish, Brent, Zhang, Jianhou, Edema, Hilary, Luong, James, Roper, Jenna, Beaudette, Chad, Echodu, Richard, and Tsutsui, Hideaki
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Bioengineering ,Capillary Action ,DNA ,Microfluidic Analytical Techniques ,Microspheres ,Paper ,Plant Extracts ,distance-based ,microsphere ,aggregation ,DNA detection ,paper-based - Abstract
In paper-based microfluidics, the simplest devices are colorimetric, giving qualitative results. However, getting quantitative data can be quite a bit more difficult. Distance-based devices provide a user-friendly means of obtaining quantitative data without the need for any additional equipment, simply by using an included ruler or calibrated markings. This article details the development of a quantitative DNA detection device that utilizes the aggregation of polystyrene microspheres to affect the distance that microspheres wick through filter paper. The microspheres are conjugated to single-stranded DNA (ssDNA) oligomers that are partially complementary to a target strand and, in the presence of the target strand, form a three-strand complex, resulting in the formation of aggregates. The higher the concentration of the target strand, the larger the aggregate, and the shorter the distance wicked by the microspheres. This behavior was investigated across a wide range of target concentrations and under different incubation times to understand aggregate formation. The device was then used to successfully detect a target strand spiked in extracted plant DNA.
- Published
- 2020
7. Hybrid paper and 3D-printed microfluidic device for electrochemical detection of Ag nanoparticle labels
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Walgama, Charuksha, Nguyen, Michael P, Boatner, Lisa M, Richards, Ian, and Crooks, Richard M
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Engineering ,Materials Engineering ,Nanotechnology ,Bioengineering ,Biotechnology ,Electrochemical Techniques ,Lab-On-A-Chip Devices ,Metal Nanoparticles ,Paper ,Printing ,Three-Dimensional ,Silver ,Chemical Sciences ,Analytical Chemistry ,Chemical sciences - Abstract
In the present article we report a new hybrid microfluidic device (hyFlow) comprising a disposable paper electrode and a three-dimensional (3D) printed plastic chip for the electrochemical detection of a magnetic bead-silver nanoparticle (MB-AgNP) bioconjugate. This hybrid device evolved due to the difficulty of incorporating micron-scale MBs into paper-only fluidic devices. Specifically, paper fluidic devices can entrap MB-containing conjugates within their cellulose or nitrocellulose fiber matrix. The hyFlow system was designed to minimize such issues and transport MB conjugates more efficiently to the electrochemical detection zone of the device. The hyFlow system retains the benefit of fluid transport by pressure-driven flow, however, no pump is required for its operation. The hyFlow device is capable of detecting either pre-formed MB-AgNP conjugates or conjugates formed in situ. The detection limit of AgNPs using this device is 12 pM, which represents just 22 AgNPs per MB.
- Published
- 2020
8. Modifying Wicking Speeds in Paper-Based Microfluidic Devices by Laser-Etching
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Kalish, Brent, Tan, Mick Kyle, and Tsutsui, Hideaki
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Fluid Mechanics and Thermal Engineering ,Engineering ,Materials Engineering ,Biotechnology ,Bioengineering ,paper-based microfluidics ,laser-etching ,wicking speeds ,faster wicking ,Nanotechnology - Abstract
Paper-based microfluidic devices are an attractive platform for developing low-cost, point-of-care diagnostic tools. As paper-based devices' detection chemistries become more complex, more complicated devices are required, often entailing the sequential delivery of different liquids or reagents to reaction zones. Most research into flow control has been focused on introducing delays. However, delaying the flow can be problematic due to increased evaporation leading to sample loss. We report the use of a CO2 laser to uniformly etch the surface of the paper to modify wicking speeds in paper-based microfluidic devices. This technique can produce both wicking speed increases of up to 1.1× faster and decreases of up to 0.9× slower. Wicking speeds can be further enhanced by etching both sides of the paper, resulting in wicking 1.3× faster than unetched channels. Channels with lengthwise laser-etched grooves were also compared to uniformly etched channels, with the most heavily grooved channels wicking 1.9× faster than the fastest double-sided etched channels. Furthermore, sealing both sides of the channel in packing tape results in the most heavily etched channels, single-sided, double-sided, and grooved, wicking over 13× faster than unetched channels. By selectively etching individual channels, different combinations of sequential fluid delivery can be obtained without altering any channel geometry. Laser etching is a simple process that can be integrated into the patterning of the device and requires no additional materials or chemicals, enabling greater flow control for paper-based microfluidic devices.
- Published
- 2020
9. Improving the Electrochemical Properties of Carbon Paper as Cathodes for Microfluidic Fuel Cells by the Electrochemical Activation in Different Solutions
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Liu, Chunmei, Sun, Canxing, Gao, Yanjun, Lan, Weijuan, and Chen, Shaowei
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Bioengineering ,Affordable and Clean Energy ,Chemical Engineering ,Materials Engineering - Abstract
Membraneless microfluidic fuel cells (MFCs) have garnered tremendous interest as micropower devices, which exploit the colaminar nature of two aqueous electrolytes to separate the anode and cathode and avoid the membrane usually used in a fuel cell. Our previous research shows that the performance of FeCl3-based MFCs with catalyst-free cathodes is mainly limited by the cathode. To improve the power output of these MFCs, we activated the carbon paper cathode by an electrochemical method in the three solutions (Na2SO4, NaOH, and H2SO4) to improve the electrochemical characteristics of the carbon paper cathode. The surface functionalities and defects, reduction activation of iron ions as the oxidant, cathode resistance, and performance of FeCl3-based MFCs were measured and compared. Our work shows that the electrochemical activation of the carbon paper in different solutions is a simple and effective method to enhance the electrochemical characteristics of the carbon paper cathode and improve the performance of the FeCl3-based MFC. Also, the MFC with the carbon paper cathode activated in the H2SO4 solution reaches the optimum performance: 235.6 mW cm-3 in volumetric power density and 1063.33 mA cm-3 in volumetric limiting current density, which are 1.58 and 1.52 times as much as that of a MFC with an untreated carbon paper cathode, respectively. This best performance can be attributed to the cathode activated in the H2SO4 solution with the largest number of oxygen-containing functional groups, the largest electrochemical active surface area, strongest reduction of iron ions, and least resistance of the cathode.
- Published
- 2021
10. 2023 Summer Biomechanics, Bioengineering, and Biotransport Conference Student Paper Competition.
- Author
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Miller, Kristin S.
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SCHOOL contests ,CONFERENCE papers ,BIOENGINEERING ,SUMMER - Published
- 2024
- Full Text
- View/download PDF
11. Design Automation for Paper Microfluidics with Passive Flow Substrates
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Potter, Joshua, Grover, William, and Brisk, Philip
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Engineering ,Information and Computing Sciences ,Fluid Mechanics and Thermal Engineering ,Materials Engineering ,Software Engineering ,Biotechnology ,Bioengineering ,Paper Microfluidics ,Design Automation ,Capillary ,Passive Flow ,Assay - Abstract
This paper introduces a novel software framework to support automated development of paper-based microuidic devices. Compared to existing lab-on-a-chip technologies, paper-based microuidics difiers in terms of substrate technologies and point-of-care usage across a wide variety environmental conditions. This paper addresses the contexts in which the software can address these challenges and presents several initial case studies that demonstrate the capabilities of the framework to produce workable and usable paper microuidic devices.
- Published
- 2017
12. Design automation for paper microfluidics with passive flow substrates
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Potter, J, Grover, W, and Brisk, P
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Paper Microfluidics ,Design Automation ,Capillary ,Passive Flow ,Assay ,Bioengineering ,Biotechnology - Abstract
This paper introduces a novel software framework to support automated development of paper-based microuidic devices. Compared to existing lab-on-a-chip technologies, paper-based microuidics difiers in terms of substrate technologies and point-of-care usage across a wide variety environmental conditions. This paper addresses the contexts in which the software can address these challenges and presents several initial case studies that demonstrate the capabilities of the framework to produce workable and usable paper microuidic devices.
- Published
- 2017
13. Using Adhesive Patterning to Construct 3D Paper Microfluidic Devices.
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Kalish, Brent and Tsutsui, Hideaki
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Biochemistry and Cell Biology ,Biological Sciences ,Bioengineering ,Adhesives ,Aerosols ,Lab-On-A-Chip Devices ,Microfluidic Analytical Techniques ,Paper ,Issue 110 ,Paper microfluidics ,nonplanar ,origami ,aerosol adhesive ,three-dimensional ,stencil ,patterning ,Psychology ,Cognitive Sciences ,Biochemistry and cell biology - Abstract
We demonstrate the use of patterned aerosol adhesives to construct both planar and nonplanar 3D paper microfluidic devices. By spraying an aerosol adhesive through a metal stencil, the overall amount of adhesive used in assembling paper microfluidic devices can be significantly reduced. We show on a simple 4-layer planar paper microfluidic device that the optimal adhesive application technique and device construction style depends heavily on desired performance characteristics. By moderately increasing the overall area of a device, it is possible to dramatically decrease the wicking time and increase device success rates while also reducing the amount of adhesive required to keep the device together. Such adhesive application also causes the adhesive to form semi-permanent bonds instead of permanent bonds between paper layers, enabling single-use devices to be non-destructively disassembled after use. Nonplanar 3D origami devices also benefit from the semi-permanent bonds during folding, as it reduces the likelihood that unrelated faces may accidently stick together. Like planar devices, nonplanar structures see reduced wicking times with patterned adhesive application vs uniformly applied adhesive.
- Published
- 2016
14. Design Automation of Paper Microfluidic Devices
- Author
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Potter, Joshua
- Subjects
Computer science ,Bioengineering ,Design automation ,microfluidics ,paper - Abstract
The emerging demands for healthcare where access is limited due to political, environmental, or socio-economic factors have been driving research into bio-medical devices that perform in both diagnostic and therapeutic roles at lower costs and greater accessibility. Paper microfluidic devices are used in many applications, particularly medical diagnostics and offer an excellent combination of utility and low cost making them particularly valuable in resource-limited applications and point-of-care usage across a wide variety environmental conditions. Microfluidic biological diagnostics continue to mature as researchers discover new ways to exploit the technological possibilities, and address liabilities. The increasing complexity of paper-based microfluidic devices beyond home pregnancy tests is driving the need to produce new tools and methodologies that enable more robust biological diagnostics and potential therapeutic applications. However, the process of developing new paper microfluidic devices is limited due to having to manually design and fabricate designs to research. Often, researchers must design scores of different devices to find a combination of parameters that functions as expected. In this work, a novel software framework to support automated development of paper-based microfluidic devices is introduced to facilitate both research and fabrication to accelerate the investigative process and reduce material utilization and manpower. Unlike to existing lab-on-a-chip technologies, paper-based microfluidics differs in terms of substrate technologies and use a passive flow method to deliver fluids and reagents for assays. While numerous analogies between microfluidics and semiconductor technologies have been espoused, the physical differences between the fluid dynamics and electrical current are significant which suggests that current trends in physical design for microfluidics must change course in order to be of practical use to designers. Within this framework, a methodology is introduced to address design automation such as dynamically placing and routing microfluidic components in a non-discrete design space while avoiding invalid design layouts, accounting for fluid volume usage, surface area utilization, and the timing required to perform specified biological assays and also optimizing device parameters, enabling researchers to focus on the science and thereby accelerating the development of new, low-resource paper microfluidic devices for a developing world.
- Published
- 2022
15. Bioengineering bacteriophages to enhance the sensitivity of phage amplification-based paper fluidic detection of bacteria.
- Author
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Alcaine SD, Law K, Ho S, Kinchla AJ, Sela DA, and Nugen SR
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- Alkaline Phosphatase genetics, Bacterial Proteins genetics, Escherichia coli genetics, Genetic Engineering methods, Limit of Detection, Maltose-Binding Proteins genetics, Up-Regulation, Bacteriophage T7 genetics, Bioengineering methods, Biosensing Techniques methods, Environmental Monitoring methods, Escherichia coli isolation & purification, Escherichia coli virology, Rivers microbiology
- Abstract
Bacteriophage (phage) amplification is an attractive method for the detection of bacteria due to a narrow phage-host specificity, short amplification times, and the phages' ability to differentiate between viable and non-viable bacterial cells. The next step in phage-based bacteria detection is leveraging bioengineered phages to create low-cost, rapid, and easy-to-use detection platforms such as lateral flow assays. Our work establishes the proof-of-concept for the use of bioengineered T7 phage strains to increase the sensitivity of phage amplification-based lateral flow assays. We have demonstrated a greater than 10-fold increase in sensitivity using a phage-based protein reporter, maltose-binding protein, over the detection of replicated T7 phage viron itself, and a greater then 100-fold increase in sensitivity using a phage-based enzymatic reporter, alkaline phosphatase. This increase in sensitivity enabled us to detect 10(3)CFU/mL of Escherichia coli in broth after 7h, and by adding a filter concentration step, the ability to detect a regulatory relevant E. coli concentration of 100CFU/100mL in inoculated river water after 9h, where the current standard requires days for results. The combination of the paper fluidic format with phage-based detection provides a platform for the development of novel diagnostics that are sensitive, rapid, and easy to use., (Copyright © 2016 Elsevier B.V. All rights reserved.)
- Published
- 2016
- Full Text
- View/download PDF
16. Metallic Nanoparticles for Expanding the Point-of-Care Applications of Paper-Based Diagnostic Devices
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Trinh, Jasmine Thanh
- Subjects
Bioengineering ,Diagnostics ,Gold nanorod ,Lateral-flow immunoassay ,Nanozyme ,Paper-based diagnostics ,Point of care - Abstract
As early diagnosis is essential for improving patient outcomes when treating both communicable and noncommunicable diseases, it is necessary to develop diagnostic tests that are accessible at the point of care. Thus, there is a need for rapid, robust, and inexpensive diagnostic tests, especially in resource-limited areas where access to healthcare is reduced. One such test is the lateral-flow immunoassay (LFA), which has seen a drastic rise in use during the COVID-19 pandemic. However, the conventional LFA suffers from a couple limitations, which this thesis aims to address. First, we address the limited sensitivity of the LFA by incorporating nanozyme signal enhancement to improve detection of the SARS-CoV-2 nucleocapsid protein in serum. By developing dehydrated signal enhancement reagents and an innovative 3D printed casing to store and deliver reagents at the push of a button, we were able to improve the limit of detection of the LFA by at least 10-fold without introducing additional complexity for the user.Next, we shifted our focus to introducing semi-quantitative results to the LFA through the multicolor etching of gold nanorods (GNRs). We demonstrated the first integration of the LFA with GNRs to produce a multicolor readout for the quantification of digoxin levels in serum. We then expanded upon this work by developing a fully paper-based assay to incorporate both the LFA detection and GNR etching steps together, which involved the design of novel color-changing GNR pads. The color hues generated by GNR etching are easily distinguishable by the naked eye, thus allowing for quantification of target biomarker concentrations at the point of care.
- Published
- 2022
17. Phytochemical analysis and insecticidal activities of seed extracts from Oenanthe pimpinelloides L. treated paper samples vs. Tribolium castaneum
- Author
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Bildik Dal, Ahsen Ezel, Özdemir, Ayşe Daut, Gücüş, Mehmet Onurhan, Herouini, Amel, Kemassi, Abdellah, and Gücüş, Mehmet Onurhan
- Subjects
Environmental Engineering ,Seed Extracts ,Tribolium Castaneum ,Bioengineering ,Oenanthe Pimpinelloides ,Waste Management and Disposal ,Paper Treatment - Abstract
WOS:000967659000009 The utilization of plant extraction products from Oeneanthe pimpinelloides (Apiaceae family) seeds were investigated in terms of their use as an insecticide control of packaging materials. The aim was to investigate their insecticidal effects against the flour beetle Tribolium castaneum. The Oeneanthe pimpinelloides seeds were extracted with methanol. By using the liquid-liquid extraction method, the hexane extract (II) was separated from the methanol extract (I) and hexane and methanol were evaporated. Then, the chemical composition of each sample was determined via gas chromatography–mass spectrometry. The methanol extract predominantly contained tetrahydrofuran, 1-methoxy-2-propanol, 1-methoxy, 2-butoxyethanol, 1-phenylethanone, cyclohexene carboxylate derivative, (3-phenyl-2-propynylidene) cyclopropane, diphenyldiazene, and dihydroxypropyl ester components, while the hexane fraction contained nonane, 1-octanol, decane, undecane, tridecane, alkyl benzene, benzene sulfonic acid, benzoxazine, and hexadecanoic acid components, as well as some derivatives of them. Each fraction was dissolved in DMSO for impregnation on filter paper. The insecticide effects of the paper samples were determined against Tribolium castneum. According to the results, the mortality started after 3 d for each fraction. After 4 d, the hexane fraction indicated total mortality in comparison with the methanol fraction, which showed partial mortality (3/5).
- Published
- 2023
18. The Development of an Interface-Locating Extraction Device for the Automated Application of Aqueous Two-Phase Systems to Rapid Paper-Based Assays
- Author
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Toubian, Adam Ashkan
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Bioengineering ,automated ,device ,diagnostics ,immunoassay ,lateral-flow ,urine - Abstract
The clinical diagnosis of urinary tract infections (UTIs) faces challenges characterized by prolonged test results, contributing to over-prescription of antibiotics, and missed diagnoses. Point-of-care (POC) tests such as the lateral-flow immunoassay (LFA) attempt to alleviate this issue by providing patients with rapid results; however, their effectiveness is limited by low sensitivity. To improve the performance of the LFA, this thesis focuses on the development of an automated device that enables the addition of a sample preconcentration step at the POC using an aqueous two-phase system (ATPS). The device utilizes a photoresistor-based interface detection algorithm to selectively extract the bottom phase of the ATPS, containing concentrated biomarker, thereby avoiding the dispensing of the undesired top phase onto an LFA. The device incorporates a custom syringe pump module to apply the sample fluid to the LFA, and a gravity-based buffer dispensing module to facilitate the application of running buffer following sample addition. The affordability of the device is ensured through the use of reusable electrical components and cost- effective consumables, making it accessible to physician offices and mobile clinics at the POC. Experimental results demonstrate the successful automation of ATPS application onto the LFA, effectively extracting the bottom phase without any of the top phase. This advancement brings sample preconcentration using an ATPS one step closer to clinical adoption, offering a sensitive, rapid, and user-friendly UTI diagnostic solution.
- Published
- 2023
19. Fluorescence‐guided surgery and intervention — An AAPM emerging technology blue paper
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Pogue, Brian W, Zhu, Timothy C, Ntziachristos, Vasilis, Paulsen, Keith D, Wilson, Brian C, Pfefer, Joshua, Nordstrom, Robert J, Litorja, Maritoni, Wabnitz, Heidrun, Chen, Yu, Gioux, Sylvain, Tromberg, Bruce J, and Yodh, Arjun G
- Subjects
Biomedical Imaging ,Bioengineering ,4.1 Discovery and preclinical testing of markers and technologies ,Detection ,screening and diagnosis ,Consensus ,Curriculum ,Health Personnel ,Humans ,Optical Imaging ,Patient Safety ,Practice Guidelines as Topic ,Societies ,Medical ,Surgery ,Computer-Assisted ,imaging ,imaging system ,intervention ,molecular ,molecular probe ,resection ,Other Physical Sciences ,Biomedical Engineering ,Oncology and Carcinogenesis ,Nuclear Medicine & Medical Imaging - Abstract
Fluorescence-guided surgery (FGS) and other interventions are rapidly evolving as a class of technologically driven interventional approaches in which many surgical specialties visualize fluorescent molecular tracers or biomarkers through associated cameras or oculars to guide clinical decisions on pathological lesion detection and excision/ablation. The technology has been commercialized for some specific applications, but also presents technical challenges unique to optical imaging that could confound the utility of some interventional procedures where real-time decisions must be made. Accordingly, the AAPM has initiated the publication of this Blue Paper of The Emerging Technology Working Group (TETAWG) and the creation of a Task Group from the Therapy Physics Committee within the Treatment Delivery Subcommittee. In describing the relevant issues, this document outlines the key parameters, stakeholders, impacts, and outcomes of clinical FGS technology and its applications. The presentation is not intended to be conclusive, but rather to inform the field of medical physics and stimulate the discussions needed in the field with respect to a seemingly low-risk imaging technology that has high potential for significant therapeutic impact. This AAPM Task Group is working toward consensus around guidelines and standards for advancing the field safely and effectively.
- Published
- 2018
20. The people behind the papers - Jingjing Sun and Angelike Stathopoulos.
- Subjects
- *
BIOENGINEERING , *GENE expression , *TRANSCRIPTION factors , *BIOLOGISTS , *BIOPHYSICS - Abstract
This article features an interview with Jingjing Sun and Angelike Stathopoulos, who conducted a study on the collective migration of caudal visceral mesoderm (CVM) cells in Drosophila embryos. They discovered that cell division coordinates two gene expression programs in migrating CVM cells. The researchers discuss their scientific backgrounds and the questions they are trying to answer in their lab. They also highlight the importance of the Drosophila system for their research. The study's key findings include the identification of two groups of genes that regulate the behaviors of CVM cells during migration, and the role of cell division in controlling gene expression programs. The researchers also discuss their motivations and future directions for their research. [Extracted from the article]
- Published
- 2024
- Full Text
- View/download PDF
21. Cross-Linking of Oxidized Hydroxypropyl Cellulose in Paper: Influence of Molecular Weight and Polymer Distribution on Paper Wet Strength Development
- Author
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David Seelinger and Markus Biesalski
- Subjects
Biomaterials ,Polymers and Plastics ,Organic Chemistry ,hydroxypropyl cellulose ,wet tensile strength ,wet strength resin ,polymer degradation ,polymer distribution in paper ,Bioengineering - Abstract
With the overarching aim for the development of sustainable, nontoxic wet strength agents for paper, a novel polymer gel system based on oxidized hydroxypropyl cellulose (keto-HPC) cross-linked with polyamines was investigated in detail to gain a deeper insight into the wet strength mechanism. When applied to paper, this wet strength system significantly increases the relative wet strength by using only low amounts of polymer, and it is therefore comparable with established wet strength agents based on fossil resources, such as polyamidoamine epichlorohydrin resins. With the help of ultrasonic treatment, keto-HPC was degraded with respect to its molecular weight and further cross-linked in paper using polymeric amine-reactive counterparts. The resulting polymer-cross-linked paper mechanical properties were analyzed with respect to the dry and wet tensile strength, respectively. In addition, we analyzed the polymer distribution using fluorescence confocal laser scanning microscopy (CLSM). If high-molecular-weight samples are being used for cross-linking, we do find accumulation of the polymer mainly on the surface of the fibers and at fiber crossing points, accompanied with enhancing strong effects on paper’s wet tensile strength. In contrast, if low-molecular-weight (i.e., degraded) keto-HPC is being applied, the macromolecules are capable of entering the inner porous structure of the paper fibers, and almost no accumulation at the fiber crossing points is observed, which also results in a lowered wet paper tensile strength, respectively. This insight into wet strength mechanisms of the keto-HPC/polyamine system can thus lead to new opportunities for the development of alternative biobased wet strength agents where molecular weight dependence of the wet tensile properties allows for a fine tuning of mechanical properties in the wet state.
- Published
- 2023
- Full Text
- View/download PDF
22. Trends in Paper-Based Sensing Devices for Clinical and Environmental Monitoring
- Author
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Shekher Kummari, Lakshmi R. Panicker, Jagadeeswara Rao Bommi, Sampath Karingula, Venisheety Sunil Kumar, Kuldeep Mahato, and Kotagiri Yugender Goud
- Subjects
Paper ,screening and diagnosis ,optical sensors ,Clinical Biochemistry ,Biomedical Engineering ,electrochemical sensors ,Bioengineering ,General Medicine ,Biosensing Techniques ,Electrochemical Techniques ,biosensors ,4.1 Discovery and preclinical testing of markers and technologies ,Analytical Chemistry ,Detection ,paper-based sensing devices ,Environmental Pollutants ,Biochemistry and Cell Biology ,Instrumentation ,Engineering (miscellaneous) ,Ecosystem ,Biotechnology ,clinical diagnostics ,environmental monitoring - Abstract
Environmental toxic pollutants and pathogens that enter the ecosystem are major global issues. Detection of these toxic chemicals/pollutants and the diagnosis of a disease is a first step in efficiently controlling their contamination and spread, respectively. Various analytical techniques are available to detect and determine toxic chemicals/pathogens, including liquid chromatography, HPLC, mass spectroscopy, and enzyme-linked immunosorbent assays. However, these sensing strategies have some drawbacks such as tedious sample pretreatment and preparation, the requirement for skilled technicians, and dependence on large laboratory-based instruments. Alternatively, biosensors, especially paper-based sensors, could be used extensively and are a cost-effective alternative to conventional laboratory testing. They can improve accessibility to testing to identify chemicals and pollutants, especially in developing countries. Due to its low cost, abundance, easy disposal (by incineration, for example) and biocompatible nature, paper is considered a versatile material for the development of environmentally friendly electrochemical/optical (bio) sensor devices. This review presents an overview of sensing platforms constructed from paper, pointing out the main merits and demerits of paper-based sensing systems, their fabrication techniques, and the different optical/electrochemical detection techniques that they exploit.
- Published
- 2023
23. Plasmonic Paper-Based Flexible SERS Biosensor for Highly Sensitive Detection of Lactic and Uric Acid
- Author
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M. Verma, Santosh K. Tripathi, N. Eswara Prasad, Prabhat K. Dwivedi, Tania K. Naqvi, and Manish M. Kulkarni
- Subjects
Silver ,Materials science ,Biomedical Engineering ,Metal Nanoparticles ,Pharmaceutical Science ,Medicine (miscellaneous) ,Preventive health ,Substrate (chemistry) ,Bioengineering ,Nanotechnology ,Biosensing Techniques ,Paper based ,Spectrum Analysis, Raman ,Uric Acid ,Computer Science Applications ,Highly sensitive ,Silver mirror ,chemistry.chemical_compound ,chemistry ,Humans ,Uric acid ,Electrical and Electronic Engineering ,Biosensor ,Plasmon ,Biotechnology - Abstract
Selective detection and quantification of biomarkers related to human diseases are essential for preventive healthcare. Surface-enhanced Raman scattering (SERS) spectroscopy is a powerful analytical tool offering high sensitivity. However, the success of this promising analytical tool relies on the ability to effectively fabricate SERS substrate. Herein we have demonstrated a plasmonic paper-based flexible substrate (PPFS) for SERS sensing. In situ growth of silver nanostructures (AgNS) on the paper-based substrate was achieved by using a simple one-step silver mirror reaction (SMR). FESEM and TEM results depicts that the increasing silver ion content influences the morphology (growth of multifacets), as well as size of AgNS. Further, the PPFS substrate was tested with Rhodamine-6G (Rh-6G) dye and an attomole sensitivity with a LOD of 4.54 x 10-18 M was achieved. Further, two biomarkers, lactic acid (LA) and uric acid (UA) were detected on the PPFS substrate, with μM and pM sensitivity, having LOD values of 0.6 x 10-6 and 0.3 x 10-12 M respectively. Above detection levels for UA on PPFS is two orders better than reported values, whereas for LA it is comparable with reported substrates. Finally, UA, LA and their mixtures were tested on PPFS and results compared with commercial substrate. The performance of PPFS were found better in all cases, thus, multifaceted AgNS paper based PPFS offers the potential to be used as a biosensor for detection of various biomarkers from body fluids, responsible for the detection of the critical disease for preventive health care.
- Published
- 2022
24. A Distance-Based Microfluidic Paper-Based Biosensor for Glucose Measurements in Tear Range
- Author
-
Mohsen Rabbani and Samira Allameh
- Subjects
Paper ,Materials science ,business.industry ,Microfluidics ,Glucose Measurement ,Bioengineering ,Biosensing Techniques ,General Medicine ,Microfluidic Analytical Techniques ,Applied Microbiology and Biotechnology ,Biochemistry ,Glucose Oxidase ,Paper based biosensor ,Glucose ,Range (statistics) ,Optoelectronics ,business ,Molecular Biology ,Horseradish Peroxidase ,Distance based ,Biotechnology - Abstract
The prevalence of diabetes has increased over the past years. Therefore, developing minimally invasive, user-friendly and cost-effective glucose biosensors is necessary especially in low-income and developing countries. Cellulose paper-based analytical devices have attracted the attention of many researchers due to affordability, not requiring trained personnel, and complex equipment. This paper describes a microfluidic paper-based analytical device for the detection of glucose in tear with the naked eye. The paper-based biosensor fabricated by laser CO2, and GOx/HRP enzymatic solution coupled with TMB was utilized as reagents. A sample volume of 10 µl was needed for the biosensor operation and the results were observable within 5 minutes. To evaluate the device performance, color intensity-based and distance-based results were analyzed by ImageJ and Tracker. Distance-based results showed a linear behavior in the range of 0.1–0.6 mM with an R2 = 0.967 and LOD of 0.2 mM. The results could be perceived by the naked eye without any need to further equipment or trained personnel in a relatively short time (3–5 minutes). Moreover, glucose concentration could be obtained non-invasively by tears collected by this µPAD.
- Published
- 2022
25. Control and Modeling of Imbibition in Paper-Based Microfluidic Devices
- Author
-
Modha, Sidharth
- Subjects
Bioengineering ,Fluid mechanics ,Materials Science - Abstract
Access to medical care is a significant challenge facing developing countries. The World Health Organization developed the ASSURED criteria, which specifies requirements for the ideal diagnostic. ASSURED stands for Affordable, Sensitive, Specific, Rapid/Robust, Equipment-free and Deliverable. Traditional microfluidic diagnostics (comprised of glass/PDMS) require expensive fabrication procedures and user-intervention to manipulate fluids on the device. For those reasons, paper shows great promise as a substrate for an ASSURED microfluidic diagnostic. It is affordable and does not require external pumping to move fluids. Initially, microfluidic paper-based analytical devices (μPADs) performed simple, colorimetric assays. However, the field has evolved rapidly. Modern μPADs have been developed for a plethora of applications such as nucleic acid amplification. Wider adaptation of μPADs relies on the incorporation of more complicated assays (i.e. involving multiple fluids), which would allow μPADs to replace more expensive benchtop equipment. This requires more robust fluid control. Typically, fluid control on μPADs has been achieved by slowing fluid down to create delays between different channels. However, adding delays increases overall assay time and creates other complications such as fluid loss due to evaporation. Instead, creating ‘delays’ by accelerating wicking (relative to native paper) is being investigated. Previous approaches include sandwiching the paper between polymer films or creating ‘macro capillaries’ within the paper for the liquid to flow through. Of particular interest is the etching of grooves onto paper channels using either a plotter or a CO2 laser. These grooves create hollow regions in the paper which lead to faster wicking speeds. This study aims to characterize the behavior of grooved channels in paper and assess their performance as ‘delay’ mechanisms for a multi-fluid paper-based sensor.Typically, μPAD designs evolve in a trial-and-error basis, where devices are fabricated, tested and updated. Having accurate models that characterize the imbibition process could streamline development by allowing direct translation of in-silico designs to fully-functioning paper-based tools. Current imbibition models do not adequately describe the complex transport phenomena occurring within the paper matrix. This study also aims to develop an in-silico simulation that can reliably predict imbibition in both native paper and grooved channels.
- Published
- 2022
26. Rapid and inexpensive process to fabricate paper based microfluidic devices using a cut and heat plastic lamination process
- Author
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Nityanand Kumawat, Soja Saghar Soman, Sanjairaj Vijayavenkataraman, and Sunil Kumar
- Subjects
Paper ,Mice ,Hot Temperature ,Lab-On-A-Chip Devices ,Biomedical Engineering ,Animals ,Humans ,Bioengineering ,General Chemistry ,Microfluidic Analytical Techniques ,Hydrophobic and Hydrophilic Interactions ,Plastics ,Biochemistry - Abstract
Microfluidic paper-based analytical devices (microPADs) are emerging as simple-to-use, low-cost point-of-care testing platforms. Such devices are mostly fabricated at present by creating hydrophobic barriers using wax or photoresist patterning on porous paper sheets. Even though devices fabricated using these methods are used and tested with a wide variety of analytes, still they pose many serious practical limitations for low-cost automated mass fabrication for their widespread applicability. We present an affordable and simple two-step process - cut and heat (CH-microPADs) - for the selective fabrication of hydrophilic channels and reservoirs on a wide variety of porous media such as tissue/printing/filter paper and cloth types, such as cotton and polyester, by a lamination process. The technique presents many advantages as compared to existing commonly used methods. The devices possess excellent mechanical strength against bending, folding and twisting, making them virtually unbreakable. They are structurally flexible and show good chemical resistance to various solvents, acids and bases, presenting widespread applicability in areas such as clinical diagnostics, biological sensing applications, food processing, and the chemical industry. Fabricated paper media 96 well-plate CH-microPAD configurations were tested for cell culture applications using mice embryonic fibroblasts and detection of proteins and enzymes using ELISA. With a simple two-step process and minimal human intervention, the technique presents a promising step towards mass fabrication of inexpensive disposable diagnostic devices for both resource-limited and developed regions.
- Published
- 2022
27. Making paper from materials that are essential to our lives/making paper without trees is the new 'Must'
- Author
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Carmen-Alice Teacă
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Paper, which is in fact a very complex cellulose-based product derived from different lignocellulosic resources, is usually regarded as a simple omnipresent commodity in our lives. Wood fibers derived from trees are the most employed sources for papermaking purposes. From an environmental protection perspective, and for their essential role in our life (they give us the life itself through their foliar system supporting the photosynthesis process), trees should not be extensively cut down and they should be used less and less for papermaking. Thus, employment of non-woody alternative sources for papermaking could be exploited more as an attractive and feasible option.
- Published
- 2023
28. Traffic light type paper-based analytical device for intuitive and semi-quantitative naked-eye signal readout
- Author
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Sera Ohta, Ryuya Hiraoka, Yuki Hiruta, and Daniel Citterio
- Subjects
Paper ,Point-of-Care Testing ,Lab-On-A-Chip Devices ,Biomedical Engineering ,Bioengineering ,Hydrogen Peroxide ,General Chemistry ,Microfluidic Analytical Techniques ,Biochemistry - Abstract
Microfluidic paper-based analytical devices (μPADs) have attracted great attention as potential candidates for point-of-care testing (POCT). Nevertheless, only a limited number of μPADs expected to satisfy the standard of Clinical Laboratory Improvement Amendments (CLIA) waived tests as issued by the US Food and Drug Administration (FDA) have been reported. This work introduces a "traffic light type μPAD", enabling highly intuitive semi-quantitative equipment-free naked-eye readout with no need for calibration, subjective interpretation or calculation. Assay results are displayed as traffic light colours reporting 5 analyte concentration levels (green/greenyellow/yellow/yellowred/red). The device has been designed to never display all three colours simultaneously, eliminating any risk for misinterpretation. The mechanism relies on the modulation of sample flow through a network of paperfluidic channels modified with a hydrophobic to hydrophilic phase-switching substance responsive to H
- Published
- 2022
29. Producing flexible calcium carbonate from waste paper and their use as fillers for high bulk paper
- Author
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Lae Hyuk Kang, Yung Bum Seo, and Jung Soo Han
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Microfibrillated cellulose (MFC) was prepared from post-consumer old corrugated container (OCC) material, which was first disintegrated in water, cleaned to remove impurities, and then fibrillated by grinding. Those processed MFCs were treated with in-situ formation of calcium carbonate by adding calcium oxide and injecting carbon dioxide into the mixture up to the ratio of 1:40 (MFC : calcium carbonate) by weight. The MFCs had a dark brown color initially but turned into high brightness materials similar to commercial ground calcium carbonate (GCC) after the in-situ formation process. The MFCs that had calcium carbonate attached on their surfaces, which were lengthy and flexible, were called flexible calcium carbonate from OCC (FCCO). Paper containing FCCO gave higher bulk, higher stiffness, and higher tensile index without lowering smoothness when compared to the paper containing commercial GCC. However, brightness was slightly lowered because of initial low brightness of the OCC. This study also demonstrated the feasibility to substitute wood fibers up to 5% with FCCO without lowering essential properties for printing paper. Benefits of the waste paper are savings of both wood resources and production cost.
- Published
- 2023
30. Energy efficiency challenges in pulp and paper manufacturing: A tutorial review
- Author
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Martin A. Hubbe
- Subjects
Exergy ,Environmental Engineering ,business.industry ,Computer science ,Pulp (paper) ,Bioengineering ,engineering.material ,Product (business) ,Cellulosic ethanol ,Process integration ,Pinch analysis ,engineering ,Electricity ,Process engineering ,business ,Waste Management and Disposal ,Efficient energy use - Abstract
The pulp and paper industry is highly energy-intensive. In mills that use chemical pulping, roughly half of the higher heating value of the cellulosic material used to manufacture the product typically is incinerated to generate steam and electricity that is needed to run the processes. Additional energy, much of it non-renewable, needs to be purchased. This review considers publications describing steps that pulp and paper facilities can take to operate more efficiently. Savings can be achieved, for instance, by minimizing unnecessary losses in exergy, which can be defined as the energy content relative to a standard ambient condition. Throughout the long series of unit operations comprising the conversion of wood material to sheets of paper, there are large opportunities to more closely approach a hypothetical ideal performance by following established best-practices.
- Published
- 2021
31. Quantitative assessment of AD markers using naked eyes: point-of-care testing with paper-based lateral flow immunoassay
- Author
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Liding Zhang, Xiaohan Liang, Yanqing Li, Haiming Luo, Xuewei Du, Shiqi Niu, and Ying Su
- Subjects
Paper ,Pathology ,medicine.medical_specialty ,Gold nanoparticle ,medicine.drug_class ,Point-of-care testing ,Biomedical Engineering ,Pharmaceutical Science ,Medicine (miscellaneous) ,Bioengineering ,Monoclonal antibody ,Applied Microbiology and Biotechnology ,Mice ,Cerebrospinal fluid ,Alzheimer Disease ,Limit of Detection ,medicine ,Quantitative assessment ,Medical technology ,Animals ,Humans ,R855-855.5 ,Immunoassay ,Amyloid beta-Peptides ,business.industry ,Aβ42 monomer ,Research ,Antibodies, Monoclonal ,Paper based ,Aβ42 oligomer ,Peptide Fragments ,Visual detection ,Blood ,Point-of-Care Testing ,Elisa test ,Paper-based lateral flow immunoassay ,Magnetic nanoparticles ,Molecular Medicine ,business ,Alzheimer’s disease ,Biomarkers ,TP248.13-248.65 ,Lateral flow immunoassay ,Biotechnology - Abstract
Aβ42 is one of the most extensively studied blood and Cerebrospinal fluid (CSF) biomarkers for the diagnosis of symptomatic and prodromal Alzheimer’s disease (AD). Because of the heterogeneity and transient nature of Aβ42 oligomers (Aβ42Os), the development of technologies for dynamically detecting changes in the blood or CSF levels of Aβ42 monomers (Aβ42Ms) and Aβ42Os is essential for the accurate diagnosis of AD. The currently commonly used Aβ42 ELISA test kits usually mis-detected the elevated Aβ42Os, leading to incomplete analysis and underestimation of soluble Aβ42, resulting in a comprised performance in AD diagnosis. Herein, we developed a dual-target lateral flow immunoassay (dLFI) using anti-Aβ42 monoclonal antibodies 1F12 and 2C6 for the rapid and point-of-care detection of Aβ42Ms and Aβ42Os in blood samples within 30 min for AD diagnosis. By naked eye observation, the visual detection limit of Aβ42Ms or/and Aβ42Os in dLFI was 154 pg/mL. The test results for dLFI were similar to those observed in the enzyme-linked immunosorbent assay (ELISA). Therefore, this paper-based dLFI provides a practical and rapid method for the on-site detection of two biomarkers in blood or CSF samples without the need for additional expertise or equipment. Graphical Abstract
- Published
- 2021
32. Programmable-Printing Paper-Based Device with a MoS2 NP and Gmp/Eu-Cit Fluorescence Couple for Ratiometric Tetracycline Analysis in Various Natural Samples
- Author
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Xiaobo Zou, Xuechao Xu, Zeng Niu, Zongbao Sun, Yunlong Gao, Haodong Pan, and Wen Zhang
- Subjects
Fluid Flow and Transfer Processes ,Materials science ,Quenching (fluorescence) ,business.industry ,Process Chemistry and Technology ,Process (computing) ,Bioengineering ,Paper based ,Sense (electronics) ,Smartphone application ,River water ,Fluorescence ,Optoelectronics ,business ,Instrumentation - Abstract
Paper-based fluorescence devices, with smartphone aids, bring considerable operation convenience for tetracycline (TC) sensing. Nevertheless, they must meet the challenge in real determination against complicated backgrounds. Considering that, we present a programmable-printing paper-based device and then apply it to TC determination for various natural samples. MoS2 NPs and Gmp/Eu-Cit are synthetized as composite probes. A static quenching process is found with MoS2 NP fluorescence at 430 nm, while significant magnification of Gmp/Eu-Cit emission is obtained at 617 nm, establishing a valuable ratiometric indicator. Remarkably, two-stage programmable printing maximizes the proposed sensing capability. A transitive device, containing a gradually changing amount of a certain probe, is prepared to sense TC. With a homemade smartphone application and 3D-printed measurement chamber, the corresponding signals are examined to explore optimal setups. These setups are automatically processed to prepare the final-version device, not requiring manual operations. Benefitting from this interesting feature, the proposed device gains many rewards in performances. It effectively senses TC in a wide range from 12.7 nM to 80 μM and simultaneously provides naked eye-legible signals and smartphone-based readouts with confident selectivity and stability. This device is consequently applied for various samples of soil, river water, milk, and serum and meets well with HPLC-MS and recovery tests.
- Published
- 2021
33. Surface characterization of paper products by profilometry with a fractal dimension analysis
- Author
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Yong Ju Lee, Young Chan Ko, Byoung Geun Moon, and Hyoung Jin Kim
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
A surface profilometry technique was used to characterize the surfaces of paper products. A stylus-contact type profilometer capable of simultaneously generating both surface roughness- and friction-profiles was used. As a stylus for the profilometer, a conical shape whose tip was rounded to have a 0.5 mm curvature radius was designed and successfully employed in both printing & writing (P&W) papers and hygiene papers such as bathroom tissues and kitchen towel. From the profiles, the mean absolute deviation (MAD) from the averages, i.e., R-MAD from the roughness average and F-MAD from the average coefficient of friction, were suggested as the new surface characterization parameters. To elucidate the surface roughness profiles by fractal dimension analysis, the variogram method was applied to get the fractal dimensions of the paper products. Generally, the value of the fractal dimension increased as the surface roughness increased. The surface profilometry technique with the fractal dimension analysis with the variogram method looks promising to gain additional insight on the surface characteristics of paper products.
- Published
- 2023
34. H2O2 bleaching of brown pulp with adsorbed xylan and its modifying effects on the mechanical properties of paper
- Author
-
Li Nanhua, Li Lizi, Zuo Leigang, Junfei Tian, Xue Zhang, Yan Luming, Xianyong Du, and He Jiang
- Subjects
Environmental Engineering ,genetic structures ,Bleach ,Pulp (paper) ,Xylan (coating) ,Bioengineering ,engineering.material ,Pulp and paper industry ,chemistry.chemical_compound ,Adsorption ,stomatognathic system ,chemistry ,Kraft process ,Hardwood ,engineering ,Hemicellulose ,sense organs ,Hydrogen peroxide ,Waste Management and Disposal - Abstract
Xylan is the primary hemicellulose in most hardwood species, especially in birch. Research has highlighted the exploitation of xylans as a strength-enhancing additive to paper due to the current trend for the effective utilization of biomass. In this paper, a new pulping process was proposed, which involved the extraction of xylan prior to pulping, followed by the re-adsorption of the pulp after the final stage in the digester, followed by a suitable bleaching process. The aim of this work was to bleach hardwood kraft pulp (brown pulp) with adsorbed birch xylan via hydrogen peroxide and study the effect of the bleaching parameters on the paper properties. The results showed that the optical properties of paper decreased; however, the mechanical properties increased after the brown pulp adsorbed birch xylan. During the bleaching process, better mechanical properties were obtained with shorter bleaching times and lower bleaching temperatures, initial pHs, and MgSO4 dosages. However, the optical properties were improved as the bleaching time, temperature, initial pH, and MgSO4 dosage were increased. The adsorption of birch xylan could effectively modify the mechanical properties of paper made from brown pulp under various phases.
- Published
- 2021
35. Pulling-Force Spinning Top for Serum Separation Combined with Paper-Based Microfluidic Devices in COVID-19 ELISA Diagnosis
- Author
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Ji Qi, Anyuan Sun, Dan Zhao, Haopeng Fang, Baolong Wang, Jianping Weng, Fanwu Gong, Bofeng Li, Huan Ma, Qiangsheng Li, Lianxin Liu, Jinglong Han, Bowei Li, Tengchuan Jin, Hua-xing Wei, Liu Liu, Hongliang He, Cuichen Ma, and Xucai Zheng
- Subjects
COVID-19 diagnosis ,Coronavirus disease 2019 (COVID-19) ,Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) ,Microfluidics ,anti-RBD antibody ,Enzyme-Linked Immunosorbent Assay ,Bioengineering ,Antibodies, Viral ,Sensitivity and Specificity ,Article ,COVID-19 Testing ,Lab-On-A-Chip Devices ,serum separation ,medicine ,Humans ,Pull force ,microfluidic devices ,Instrumentation ,Spinning ,Fluid Flow and Transfer Processes ,medicine.diagnostic_test ,Human blood ,SARS-CoV-2 ,business.industry ,Process Chemistry and Technology ,COVID-19 ,Paper based ,Immunoassay ,business ,paper-based ELISA ,Biomedical engineering - Abstract
The spread of Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2), resulting in a global pandemic with around four million deaths. Although there are a variety of nucleic acid-based tests for detecting SARS-CoV-2, these methods have a relatively high cost and require expensive supporting equipment. To overcome these limitations and improve the efficiency of SARS-CoV-2 diagnosis, we developed a microfluidic platform that collected serum by a pulling-force spinning top and paper-based microfluidic enzyme-linked immunosorbent assay (ELISA) for quantitative IgA/IgM/IgG measurements in an instrument-free way. We further validated the paper-based microfluidic ELISA analysis of SARS-CoV-2 receptor-binding domain (RBD)-specific IgA/IgM/IgG antibodies from human blood samples as a good measurement with higher sensitivity compared with traditional IgM/IgG detection (99.7% vs 95.6%) for early illness onset patients. In conclusion, we provide an alternative solution for the diagnosis of SARS-CoV-2 in a portable manner by this smart integration of pulling-force spinning top and paper-based microfluidic immunoassay.
- Published
- 2021
36. Fabrication of super-hydrophobic filter paper via mixed wax phase separation for efficient oil/water separation
- Author
-
Yating Wang, Xiaochun Chen, Chenghua Yu, and Yaqi Liang
- Subjects
Wax ,Coated paper ,Environmental Engineering ,Materials science ,Filter paper ,Papermaking ,Bioengineering ,Beeswax ,Micrometre ,Contact angle ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,visual_art ,visual_art.visual_art_medium ,Carnauba wax ,Waste Management and Disposal - Abstract
Despite previous efforts, the fabrication of superhydrophobic substrate via an environment friendly and easy approach remains a great challenge. In this study, a low cost, simple, and green procedure was developed to prepare a superhydrophobic paper surface that is acceptable for the papermaking industry. First, a wax mixture (beeswax & carnauba wax) was emulsified and coated on the filter paper surface. Then, the coated paper was annealed at different temperatures. The further heat-treatment-rendered wax-coated paper hydrophobic or superhydrophobic because submicrometer or micrometer wax structures were present on the paper surface. The water contact angle of the annealed filter paper sample reached 151.5° at 60 °C, and the sliding angle was under 10°. Further, the relationship between surface composition and the hydrophobic properties of the coated paper samples was discussed. The obtained paper samples showed great potential in water/oil separation, as they had an efficiency over 99%. This work proposed a new simple and mild approach to fabricate superhydrophobic filter papers and explored the hydrophobicity and water/oil separation properties.
- Published
- 2021
37. Developing a Paper-Based Diagnostic Kit for the Detection of a Malaria Biomarker in Serum
- Author
-
Diaz, Alexia Chantha Jaotegan
- Subjects
Bioengineering ,Aqueous two-phase system (ATPS) preconcentration ,Lateral-flow immunoassay (LFA) ,Malaria ,Nanozyme signal enhancement ,Platinum-coated gold nanozyme probes (PtGNP) ,Point-of-care diagnostics - Abstract
The prevalence of malaria across the globe creates the need for the development of diagnostic devices, as many deaths caused by malaria could be prevented by early diagnosis and treatment. Since typical symptoms of malaria, such as fever and chills, are challenging to distinguish from other diseases, diagnostic tests are crucial for allowing patients to receive the appropriate medical care. While current gold-standard methods such as microscopy are able to identify the presence and species of malaria parasites, the sensitivity achieved with these methods depends on the microscopist’s training, as well as access to resources such as lab equipment and power. Disparities in supplies and training lead to late or incorrect diagnosis in resource-limited areas across the globe. This has led to the development of point-of-care devices, which provide more rapid results without the need for expensive lab equipment or training. One example of such a device is the lateral-flow immunoassay (LFA), which has commonly found use as at-home pregnancy tests and recently as COVID-19 tests. Although the LFA is simple to use and provides easy-to-read results, currently available LFAs for malaria detection suffer from lower sensitivity compared to laboratory tests. In this thesis, I investigate methods for improving the detection of the malaria antigen Plasmodium falciparum lactate dehydrogenase (pLDH).Methods to improve the detection of the LFA include biomarker preconcentration and signal enhancement. Biomarker preconcentration can be achieved using aqueous two-phase systems (ATPSs), which are liquid-liquid extraction systems composed mostly of water. Molecules that are added into an ATPS can be concentrated into the smaller of the two phases. In addition, the sensitivity of the LFA can be improved through the use of signal enhancement, which aims to increase the intensity at the detection zone with the use of additional or modified colorimetric indicators.In Chapter 2, we focus on using a polymer-salt ATPS to purify the serum sample and concentrate pLDH into the smaller salt-rich phase of the ATPS via colorimetric probes to capture the biomarker. In addition, we used signal enhancement via platinum-coated gold nanozyme probes (PtGNPs) to improve the test line intensity, allowing us to detect pLDH at concentrations as low as 0.01 ng/mL in serum. This LFA with improved detection has the potential for early detection of malaria when parasite concentrations are low, which can help patients receive access to treatment before their symptoms worsen.
- Published
- 2022
38. Integrated intravascular ultrasound and optical coherence tomography technology: a promising tool to identify vulnerable plaques [INVITED PAPER]
- Author
-
Li, Jiawen and Chen, Zhongping
- Subjects
Fluid Mechanics and Thermal Engineering ,Engineering ,Biomedical Engineering ,Bioengineering ,Heart Disease - Coronary Heart Disease ,Cardiovascular ,Biomedical Imaging ,Heart Disease ,Atherosclerosis ,Detection ,screening and diagnosis ,4.2 Evaluation of markers and technologies ,IVUS ,Optical coherence tomography ,cardiology ,integraged IVUS/OCT ,intravascular OCT ,intravascular imaging ,multi-modality imaging ,ultrasound ,vulnerable plaques - Abstract
Heart attack is mainly caused by the rupture of a vulnerable plaque. IVUS-OCT is a novel medical imaging modality that provides opportunities for accurate assessment of vulnerable plaques in vivo in patients. IVUS provides deep penetration to image the whole necrotic core while OCT enables accurate measurement of the fibrous cap of a plaque owing to its high resolution. In this paper, the authors describe the fundamentals, the technical designs and the applications of IVUS-OCT technology. Results from cadaver specimens are summarized, which indicated the complementary nature of OCT and IVUS for assessment of vulnerable plaques, plaque composition, and stent-tissue interactions. Furthermore, previously reported in vivo animal experiments are reviewed to assess the clinical adaptability of IVUS-OCT. Future directions for this technology are also discussed in this review.
- Published
- 2015
39. Xylanolytic Enzymes in Pulp and Paper Industry: New Technologies and Perspectives
- Author
-
Rajeev Kumar Kapoor, Pratyoosh Shukla, Guddu Kumar Gupta, and Mandeep Dixit
- Subjects
Laccase ,chemistry.chemical_classification ,biology ,Biomass ,Bioengineering ,Cellulase ,Raw material ,Biodegradation ,Pulp and paper industry ,Applied Microbiology and Biotechnology ,Biochemistry ,Xylan ,Enzyme ,chemistry ,biology.protein ,Xylanase ,Molecular Biology ,Biotechnology - Abstract
The pulp and paper industry discharges massive amount of wastewater containing hazardous organochlorine compounds released during different processing stages. Therefore, some cost-effective and nonpolluting practices such as enzymatic treatments are required for the potential mitigation of effluents released in the environment. Various xylanolytic enzymes such as xylanases, laccases, cellulases and hemicellulases are used to hydrolyse raw materials in the paper manufacturing industry. These enzymes are used either individually or in combination, which has the efficient potential to be considered for bio-deinking and bio-bleaching components. They are highly dynamic, renewable, and high in specificity for enhancing paper quality. The xylanase act on the xylan and cellulases act on the cellulose fibers, and thus increase the bleaching efficacy of paper. Similarly, hemicellulase enzyme like endo-xylanases, arabinofuranosidase and β-d-xylosidases have been described as functional properties towards the biodegradation of biomass. In contrast, laccase enzymes act as multi-copper oxidoreductases, bleaching the paper by the oxidation and reduction process. Laccases possess low redox potential compared to other enzymes, which need some redox mediators to catalyze. The enzymatic process can be affected by various factors such as pH, temperature, metal ions, incubation periods, etc. These factors can either increase or decrease the efficiency of the enzymes. This review draws attention to the xylanolytic enzyme-based advanced technologies for pulp bleaching in the paper industry.
- Published
- 2021
40. On-chip Paper Electrophoresis for Ultrafast Screening of Infectious Diseases
- Author
-
Ki-Hun Jeong, Hamin Na, Yoosik Kim, Byoung-Hoon Kang, and Jayoung Ku
- Subjects
Chemistry ,viruses ,Biomedical Engineering ,Outbreak ,RNA ,Bioengineering ,Paper electrophoresis ,Genome ,Virology ,Virus ,RNA silencing ,Capillary electrophoresis ,Viral disease ,Electrical and Electronic Engineering ,Biotechnology - Abstract
The outbreak of new viral strains promotes advances in universal diagnostic techniques for detecting infectious diseases with unknown viral sequence. Long double-stranded RNA (dsRNA), a hallmark of infections, serves as a virus marker for prompt detection of viruses with unknown genomes. Here, we report on-chip paper electrophoresis for ultrafast screening of infectious diseases. Negatively charged RNAs pass through the micro and nanoscale pores of cellulose in order of size under an external electric field applied to the paper microfluidic channel. Quantitative separation of long dsRNA mimicking poly I:C was analyzed from 1.67 to 33 ng·μL−1, which is close to the viral dsRNA concentration in infected cells. This paper-based capillary electrophoresis chip (paper CE chip) can provide a new diagnostic platform for ultrafast viral disease detection at the point-of-care (POC) level.
- Published
- 2021
41. In situ formation of zinc oxide on bamboo bleached pulp in preparation of antibacterial paper: Effect of precursors addition
- Author
-
Zakiah Sobri, Norzita Yacob, Luqman Chuah Abdullah, Paik San H'ng, Ainun Zuriyati Mohamed Asa’ari, and Edi Syams Zainudin
- Subjects
In situ ,Environmental Engineering ,Materials science ,Scanning electron microscope ,Pulp (paper) ,chemistry.chemical_element ,Bioengineering ,Zinc ,engineering.material ,Amorphous solid ,Field emission microscopy ,Crystallinity ,chemistry ,engineering ,Dispersion (chemistry) ,Waste Management and Disposal ,Nuclear chemistry - Abstract
An approach of green in situ synthesis single-step method was applied to produce antibacterial paper. The objective was to investigate the effect of precursor addition on the formation of zinc oxide particles using an in situ single-step method. Zinc chloride concentrations of 0.1, 0.3, 0.5, and 0.7 M were prepared and added into a solution of algae extract and bamboo pulp. The prepared pulps were tested and made into handsheets using a papermaking machine based on TAPPI T205 (2006). Morphological observation of treated papers was conducted using a field emission scanning electron microscope (FESEM). An average of 400 to 570 nm zinc oxide spherical-shaped particle was observed on the fibers of paper. The percentage of element composition of the treated paper were 15.08% to 34.08% of zinc and 17.45% to 32.59% of oxygen captured via scanning electron microscopy with energy dispersive X-ray (SEM-EDX) analysis. The crystallinity test was performed using X-ray dispersion (XRD). A higher percentage of precursors exhibited a more amorphous structure. A measurement of more than 30% increment of inhibition zone was obtained from 10.00 to 25.00 mm against S. aureus, S. choleraesuis, and E. coli. Precursors addition of more than 0.3 M would have the most potential to enhance the growth of zinc oxide via in situ preparation, hence providing better antibacterial properties of the prepared papers.
- Published
- 2021
42. Preparation and characterization of cellulose nanocrystals from paper mulberry fibers
- Author
-
Hae Min Jo, Soo Hyun Lee, and Ji Young Lee
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
The applicability of paper mulberry fiber (PM-FB), which is bast fiber, for manufacturing cellulose nanocrystals (CNCs) with high-yield was investigated. The PM-FB and hardwood bleached kraft pulp (Hw-BKP) were hydrolyzed under different sulfuric acid concentrations, reaction times, and reaction temperatures. The dependence of the CNC yield on the hydrolysis conditions and crystallinity of the raw materials was analyzed. The functional groups of the CNCs and their zeta potentials were determined. The fiber length and width of the individual CNCs were determined by transmission electron microscopy image analysis. The PM-FB showed a higher crystallinity of 86.8% compared to that of Hw-BKP and exhibited a high CNC yield of 55% under strong hydrolysis conditions. The sulfate group was introduced into the CNCs, which increased their negative charge. The fiber width of PM-FB-based CNCs (PM-CNCs) was larger than that of Hw-BKP-based CNCs (Hw-CNCs), and the aspect ratio ranged from 29.0 to 12.2 depending on the hydrolysis conditions. The yield of PM-CNCs was higher than that of Hw-CNCs under the same hydrolysis conditions. In addition, both CNCs exhibited similar quality. Therefore, PM-FB is a promising raw material for efficient CNC manufacturing.
- Published
- 2023
43. Mechanical behavior of toilet paper perforation
- Author
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Joana Vieira, Paulo Torrão Fiadeiro, André Vieira, Ana Paula Cabral Seixas Costa, Ana M. M. S. Carta, and António de Oliveira Mendes
- Subjects
Environmental Engineering ,business.industry ,Limit value ,Perforation (oil well) ,Bioengineering ,Structural engineering ,Finite element method ,Tissue paper ,Line (geometry) ,Ultimate tensile strength ,Toilet paper ,business ,Waste Management and Disposal ,Stress concentration ,Mathematics - Abstract
Perforation is used in multilayer tissue products, such as toilet and kitchen papers, as part of the converting process. Perforation facilitates the detachment of consecutive sheets by the user. The compromise between the strength required to detach a perforated sheet and the strength required to break a sheet affects the perforation efficiency. In this work, the mechanical behaviors of 15 commercial papers from different European producers were studied. A morphological analysis of the materials was performed, followed by the determination of their perforation efficiency (through tensile tests). A qualitative analysis of the cuts quality, along with a quantitative analysis of the same cuts dimensions was performed through an optical system. Finally, the stress concentration in the holes and the influence of the cuts distance were analyzed using a finite element model implemented in Abaqus/Standard finite element software. The results showed that a cut distance of 2.0 mm should not be used in these types of papers, and the perforation efficiency increased with the cut distance, regardless of the number of plies in the toilet paper. The stress concentration factor was also determined to have a limit value of 0.11. Papers above this limit value tear at the perforation line, as desired.
- Published
- 2021
44. Replacement of imported long fiber kraft pulp with lignocellulosic nanofibers and cationic materials in the production of durable paper
- Author
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Jafar Ebrahimpour Kasmani, Hassan Mohammadpour, and Ahmad Samariha
- Subjects
Environmental Engineering ,Materials science ,Starch ,Pulp (paper) ,Cationic polymerization ,Bioengineering ,engineering.material ,Folding endurance ,chemistry.chemical_compound ,Kraft process ,Chemical engineering ,chemistry ,Ultimate tensile strength ,engineering ,Cellulose ,Waste Management and Disposal ,Kraft paper - Abstract
Usage of cellulosic nanofibers, starch-nanocellulose, and polyacrylamide-nanocellulose hybrid systems were investigated for the replacement of imported long bleached kraft fibers in the production of durable papers. In this study, imported softwood kraft pulp was added to cotton pulp at four levels. Nanofibrillated cellulose (NFC) prepared from chemimechanical pulp was added to cotton pulp at a 5% level with optional 1% cationic starch or 0.1% cationic polyacrylamide. Comparative tests were done without NFC at three levels of either cationic starch or cationic polyacrylamide. For each condition, 80 gm-2 handsheets were made, and the physical, mechanical, and optical properties of the paper were compared. The results showed that increases of NFC yielded higher surface smoothness, tensile strength, resistance to bursting, tearing energy, folding endurance, yellowness, and opacity. It also reduced brightness and porosity whether added singly or in combination with cationic starch or polyacrylamide. Increasing cationic starch also increased surface smoothness, tensile strength, resistance to bursting, and folding endurance, but paper opacity was reduced. The field emission-scanning electron microscopy results showed that increased NFC reduced porosity, the paper surface became smoother, and the pores were relatively filled. Finally, the combined treatment of 5% NFC and 1% cationic starch is introduced as a suitable combination.
- Published
- 2021
45. A microfluidic fully paper-based analytical device integrated with loop-mediated isothermal amplification and nano-biosensors for rapid, sensitive, and specific quantitative detection of infectious diseases
- Author
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Hamed Tavakoli, Elisabeth Hirth, Man Luo, Sanjay Sharma Timilsina, Maowei Dou, Delfina C. Dominguez, and XiuJun Li
- Subjects
Lab-On-A-Chip Devices ,Microfluidics ,Biomedical Engineering ,Humans ,Bioengineering ,General Chemistry ,Neisseria meningitidis ,Biochemistry ,Nucleic Acid Amplification Techniques ,Communicable Diseases - Abstract
Bacterial meningitis, an infection of the membranes (meninges) and cerebrospinal fluid (CSF) surrounding the brain and spinal cord, is one of the major causes of death and disability worldwide. Higher case-fatality rates and short survival times have been reported in developing countries. Hence, a quick, straightforward, and low-cost approach is in great demand for the diagnosis of meningitis. In this research, a microfluidic fully paper-based analytical device (μFPAD) integrated with loop-mediated isothermal amplification (LAMP) and ssDNA-functionalized graphene oxide (GO) nano-biosensors was developed for the first time for a simple, rapid, low-cost, and quantitative detection of the main meningitis-causing bacteria
- Published
- 2023
46. A comparative fiber morphological analysis of major agricultural residues (used or investigated) as feedstock in the pulp and paper industry
- Author
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Zoltán Börcsök, Levente Csóka, Vladimír Gryc, Kyriaki Giagli, Zoltán Pásztory, and Dimitrios Tsalagkas
- Subjects
Environmental Engineering ,biology ,Chemistry ,Pulp (paper) ,Bioengineering ,Miscanthus ,engineering.material ,biology.organism_classification ,Sunflower ,Husk ,Animal science ,Stalk ,Hardwood ,engineering ,Fiber ,Bagasse ,Waste Management and Disposal - Abstract
The suitabilities of major agricultural residues were assessed as papermaking feedstocks. All the examined agricultural residues were assumed as potential candidates for substituting hardwood fibers in mixed pulp blends from a fiber morphological perspective. Wheat, barley, rice, rapeseed, maize, sunflower, sugarcane bagasse, coconut husk, and two genotypes of miscanthus grass underwent identical maceration. The fiber length, fiber width, cell wall thickness, and lumen diameter were measured to calculate the slenderness ratio, flexibility coefficient, and Runkel ratio. The average fiber length ranged from 0.50 mm ± 0.32 mm (MG-S-02-V) to 1.15 mm mm ± 0.58 mm (sugarcane bagasse). The fiber width ranged from 10.77 μm ± 3.28 μm (rice straw) to 22.99 mm ± 5.20 mm (sunflower stalk). The lumen diameter ranged from 4.52 μm ± 2.52 μm (rice straw) to 13.23 μm ± 4.87 μm (sunflower stalk). The cell wall thickness ranged from 3.02 μm ± 0.95 μm (rice straw) to 4.80 μm ± 1.48 μm (sunflower stalk). The slenderness ratio, flexibility coefficient, and Runkel ratio values ranged between 28.08 to 58.11, 37.97 to 60.8, and 0.62 to 1.68, respectively. Wheat, maize, rapeseed, sugarcane bagasse, and coconut husk were found to be appropriate residue sources for papermaking feedstocks.
- Published
- 2021
47. Changes in fold cracking properties and mechanical properties of high-grammage paper as affected by additive and fillers
- Author
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Dong-Seop Kim and Yong Joo Sung
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Fold cracking, which reduces the economic feasibility of paper-making, is a localized surface deformation caused by extreme bending stress. Most paper products, such as base paper and coated paper, generate fold cracking during folding processing. To control fold cracking, the mechanical properties of the base paper can be strengthened, and the flexibility of the structure can be increased by controlling the modification in pulp fibers and stock preparation conditions. This study analyzed the changes in the mechanical properties of high-grammage paper in response to the addition of precipitated calcium carbonate (PCC) and cationic starch (C-starch). The application of inorganic filler (PCC) drastically reduced the internal bond strength and tensile strength, causing fold cracking, whereas C-starch increased the bond strength between fibers, which improved the tensile strength, internal bond strength, and elongation. However, when applied independently, fold cracking occurred because of extreme increase or decrease in strength. Therefore, the combined application of C-starch and PCC made it possible to form a paper-based structure with high fold cracking resistance. Moreover, when the fold cracking resistance was excellent, the mechanical properties were balanced without being biased in one direction even under conditions of relatively low mechanical properties.
- Published
- 2023
48. Mechanical properties of paper saturated with a hydrophobic ionic liquid
- Author
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Christiane Helbrecht, Fabian Schmitt, Tobias Meckel, Markus Biesalski, Bastian J. M. Etzold, and Samuel Schabel
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Research into paper-based devices and ionic liquids has increased considerably in the past few years. Thus, the combination of paper-based devices with ionic liquids is also becoming an increasingly frequent research subject. However, the influence of the ionic liquid on the paper properties has been hardly considered. In this paper, the influence of a hydrophobic ionic liquid (1-butyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl)imide) on the mechanical properties of laboratory paper, isotropic and oriented, made from eucalyptus sulfate and cotton linters, is investigated. The tensile strength, elastic modulus, and breaking strain of papers saturated with ionic liquid were about 60 to 90% of the dry paper characteristics. In contrast to water, the breaking strain did not increase in the presence of the ionic liquid. This is because the ionic liquid only slightly swelled the fibers.
- Published
- 2023
49. Enhancing strength properties of recycled paper with TEMPO-oxidized nanocellulose
- Author
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Eti Indarti, Khairul Hafizuddin Abdul Rahman, Mazlan Ibrahim, and Wan Rosli Wan Daud
- Subjects
Environmental Engineering ,Bioengineering ,Waste Management and Disposal - Abstract
Recycled fibers used in the manufacturing of paper and board are associated with strength deficiencies. This study investigated the use of TEMPO-oxidized nanocellulose from oil palm empty fruit bunch (OPEFB-TEMPO) for reinforcing papers made from such fibers. Strength properties of tensile and tear were enhanced with the addition of OPEFB-TEMPO, with strong correlations, as indicated by the R2 values. The reinforcement capability was supported by the scattering coefficient-percent relationship. The only drawback of the nanocellulose addition is that it reduces pulp drainability, which can be minimized by adding drainage aids. Because only a relatively small amount is required, OPEFB-TEMPO has the potential to be used as paper strengthening agent, particularly in the production of low grammage papers.
- Published
- 2023
50. A low-cost, paper-based hybrid capture assay to detect high-risk HPV DNA for cervical cancer screening in low-resource settings
- Author
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Chelsey A. Smith, Megan M. Chang, Kathryn A. Kundrod, Emilie N. Novak, Sonia G. Parra, Leticia López, Celda Mavume, Cesaltina Lorenzoni, Mauricio Maza, Mila P. Salcedo, Jennifer L. Carns, Ellen Baker, Jane Montealegre, Michael Scheurer, Philip E. Castle, Kathleen M. Schmeler, and Rebecca R. Richards-Kortum
- Subjects
Biomedical Engineering ,Bioengineering ,General Chemistry ,Biochemistry - Abstract
Cervical cancer is a leading cause of cancer death for women in low-resource settings. The World Health Organization recommends that cervical cancer screening programs incorporate HPV DNA testing, but available tests are expensive, require laboratory infrastructure, and cannot be performed at the point-of-care. We developed a two-dimensional paper network (2DPN), hybrid-capture, signal amplification assay and a point-of-care sample preparation protocol to detect high-risk HPV DNA from exfoliated cervical cells within an hour. The test does not require expensive equipment and has an estimated cost of$3 per test without the need for batching. We evaluated performance of the paper HPV DNA assay with short synthetic and genomic HPV DNA targets, HPV positive and negative cellular samples, and two sets of clinical samples. The first set of clinical samples consisted of 16 biobanked, provider-collected cervical samples from a study in El Salvador previously tested with careHPV and subsequently tested in a controlled laboratory environment. The paper HPV DNA test correctly identified eight of eight HPV-negative clinical samples and seven of eight HPV-positive clinical samples. We then performed a field evaluation of the paper HPV DNA test in a hospital laboratory in Mozambique. Cellular controls generated expected results throughout field testing with fully lyophilized sample preparation and 2DPN reagents. When evaluated with 16 residual self-collected cervicovaginal samples previously tested by the GeneXpert HPV assay ("Xpert"), the accuracy of the HPV DNA paper test in the field was reduced compared to testing in the controlled laboratory environment, with positive results obtained for all eight HPV-positive samples as well as seven of eight HPV-negative samples. Further evaluation showed reduction in performance was likely due in part to increased concentration of exfoliated cells in the self-collected clinical samples from Mozambique compared with provider-collected samples from El Salvador. Finally, a formal usability assessment was conducted with users in El Salvador and Mozambique; the assay was rated as acceptable to perform after minimal training. With additional optimization for higher cell concentrations and inclusion of an internal cellular control, the paper HPV DNA assay offers promise as a low-cost, point-of-care cervical cancer screening test in low-resource settings.
- Published
- 2023
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