Urinary tract infections (UTIs) make up a significant proportion of the global burden of disease in vulnerable groups and tend to substantially impair the quality of life of those affected, making ...timely detection of UTIs a priority for public health. However, economic and societal barriers drastically reduce accessibility of traditional lab-based testing methods for critical patient groups in low-resource areas, negatively affecting their overall healthcare outcomes. As a result, cellulose-based materials such as paper and thread have garnered significant interest among researchers as substrates for so-called frugal analytical devices which leverage the material’s portability and adaptability for facile and reproducible diagnoses of UTIs. Although the field may be only in its infancy, strategies aimed at commercial penetration can appreciably increase access to more healthcare options for at-risk people. In this review, we catalogue recent advances in devices that use cellulose-based materials as the primary housing or medium for UTI detection and chart out trends in the field. We also explore different modalities employed for detection, with particular emphasis on their ability to be ported onto discreet casings such as sanitary products.
Graphical abstract
This study employs a commercial multifilament cotton thread as a low-cost microbial identification assay integrated with smartphone-based imaging for high throughput and rapid detection of pathogens. ...The thread device with inter-twined fibers was drop-cast with test media and a pH indicator. The target pathogens scavenge the media components with different sugars and release acidic by-products, which in turn act as markers for pH-based color change. The developed thread-based proof-of-concept was demonstrated for the visual color detection (red to yellow) of
Candida albicans
( 16 hours) and
Escherichia coli
( 5 hours). Besides that, using a smart-phone to capture images of the thread-based colorimetric assay facilitates early detection of turning point of the pH-based color change and further reduces the detection time of pathogens
viz. Candida albicans
( 10 hours) and
Escherichia coli
( 1.5 hours). The reported thread and smartphone integrated image analysis works towards identifying the turning point of the colorimetric change rather than the end-point analysis. Using this approach, the interpretation time can be significantly reduced compared to the existing conventional microbial methods ( 24 hours). The thread-based colorimetric microbial assay represents a ready-to-use, low-cost and straightforward technology with applicability in resource-constrained environments, surpassing the need for frequent fresh media preparation, expensive instrumentation, complex fabrication techniques and expert intervention. The proposed method possesses high scalability and reproducibility, which can be further extended to bio(chemical) assays.
A proof-of-concept unifying thread devices and smart-phone imaging for low-cost microbial detection based on simple colour change.
Packed bed column studies were carried out to evaluate the performance of chemically modified adsorbents for the sequestration of hexavalent chromium from synthetic and electroplating industrial ...effluent. The effects of parameters such as bed height (3–9 cm), inlet flow rate (5–15 mL/min), and influent Cr(VI) concentration (50–200 mg/L) on the percentage removal of Cr(VI) and the adsorption capacity of the adsorbents in a packed bed column were investigated. The breakthrough time increased with increasing bed height and decreased with the increase of inlet flow rate and influent Cr(VI) concentration. The adsorption column models such as Thomas, Adams–Bohart, Yoon–Nelson, and bed depth service time (BDST) were successfully correlated with the experimental data. The Yoon–Nelson and BDST model showed good agreement with the experimental data for all the studied parameter conditions. Results of the present study indicated that the chemically modified
Swietenia mahagoni
shell can be used as an adsorbent for the removal of Cr(VI) from industrial wastewater in a packed bed column.
In this study, batch removal of hexavalent chromium from aqueous solutions by powdered Colocasia esculenta leaves was investigated. Batch experiments were conducted to study the effects of adsorption ...of Cr(VI) at different pH values, initial concentrations, agitation speeds, temperatures, and contact times. The biosorbent was characterized by scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectrometer analysis. The biosorptive capacity of the adsorbent was dependent on the pH of the chromium solution in which maximum removal was observed at pH 2. The adsorption equilibrium data were evaluated for various adsorption isotherm models, kinetic models, and thermodynamics. The equilibrium data fitted well with Freundlich and Halsey models. The adsorption capacity calculated was 47.62Â mg/g at pH 2. The adsorption kinetic data were best described by pseudo-second-order kinetic model. Thus, Colocasia esculenta leaves can be considered as one of the efficient and cheap biosorbents for hexavalent chromium removal from aqueous solutions.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
Display omitted
•Liquid-liquid flow maps in a circular microchannel of varying confluence angle was established.•Confluence angle has 17.78% effect on flow pattern formation.•GRNN exhibited better ...prediction.•The system was interpreted using state space models.
The flow pattern map for liquid-liquid system in a circular microchannel of 600μm was experimentally investigated for a varying confluence angle (10–170 degree) of inlet fluids. The experimental results showing distinguishing nature of transition boundaries were established using graphical interpretation. Investigations were carried out to find a better objective flow pattern indicator for a vast flow pattern observations. Studies on advanced feed-forward back-propagation networks and radial basis networks such as CFN, ANN-FF, ANN-PR, PNN, GRNN and ANFIS showed that GRNN (Generalized Regression Neural Network) showed a better prediction over other prediction techniques with a R2 value of 0.988. The relative impact of input variables such as confluence angle, superficial velocity of dodecane and superficial velocity of water on flow pattern formation was found to be 17.78%, 43.30% and 38.92% respectively. The discrete and continuous time state space models for the system was also developed and interpreted in detail using system identification technique for the better understanding of the system.
India is an agrarian country with a long history of traditional food processing practices and Short food supply chains (SFSC). However, last few decades saw a huge investment and steady increase in ...large scale integrated food processing units to combat globalization, food security and India’s export demands. Recent outbreak of COVID-19 has manifested the drawbacks in the existing production and supply chain system with a wide range of issues and enforces the need for a more balanced approach. This scenario can be commonly observed in many other agrarian developing nations. This article discusses various issues concerning the existing integrated food processing sectors such as high energy consumption, greenhouse gas emissions and food insecurity during disasters and pandemic outbreaks. Moreover, we emphasise a more sustainable approach with a better balance and understanding between SFSC and integrated food processing. A potential solution in this scenario would be, rejuvenating SFSC and traditional food processing approaches along with integrated food processing units. An approach of this kind, opens up new possibilities for a next generation process-supply system.
The flow pattern map for a liquid–liquid system in a 600 μm circular microchannel was experimentally investigated for a varying Y-junction confluence angle (10° to 180°). The experimental results ...showing the distinguishing nature of transition boundaries were established using graphical interpretation. This paper tries to find a better objective flow pattern indicator for vast amounts of experimental data. Studies have been carried out using significant feed-forward back-propagation networks and radial-basis networks such as artificial neural network–pattern recognition (ANN-PR), artificial neural network–function fitting (ANN-FF), cascade-forward network (CFN), probabilistic neural network (PNN), generalized-regression neural network (GRNN), and adaptive neuro-fuzzy inference system (ANFIS). From the study, we found that GRNN showed better prediction ability than the other prediction techniques. Discrete- and continuous-time state-space models for the system were also developed using the system identification technique.
Induced flow inside a droplet by static electrical charge Pradhan, Tapan Kumar; Banuprasad, Theneyur Narayanaswamy; Nandagopal, M S Giri ...
Journal of micromechanics and microengineering,
02/2023, Letnik:
33, Številka:
2
Journal Article
Recenzirano
Odprti dostop
Abstract
Introducing controlled fluid motion in a droplet turns out to be of outstanding scientific importance, hallmarked by a plethora of applications ranging from engineering to biology. While ...internal mechanisms such as interfacial tension or buoyancy-driven dynamics may trigger fascinating flow structures inside a droplet, controllability of the same without external forcing remains questionable. On the other hand, in an electrically forced environment, complex fabrication steps and special choices of the ionic liquid are often demanded. Circumventing these limits, here we bring out a new method of flow manipulation inside a sessile droplet by simply deploying a static charge produced by the triboelectric effect. This is physically actuated by charge transfer between the two lateral electrodes within which the droplet is entrained, triggering a strong ionized air current. The flow inside the droplet is generated due to the shear exerted at the interface by the charge-induced ionized airflow around the droplet, a paradigm that has hitherto remained unexplored. The strength of the fluid flow can be controlled by adjusting the supplied static charge. Such unique controllability without sacrificing the physical simplicity opens up new possibilities for flow manipulation in a multitude of applications ranging from droplet microreactors to digital microfluidics.
We present a high resolution, ultra-frugal printing of paper microfluidic devices using in-house paraffin formulation on a simple filter paper. The patterns printed using an office inkjet printer ...formed a selective hydrophobic barrier of 4 ± 1 µm thickness with a hydrophilic channel width of 275 µm. These printed patterns effectively confine common aqueous solutions and solvents, which was verified by solvent compatibility studies. SEM analysis reveals that the solvent confinement is due to pore blockage in the filter paper. The fabricated paper-based device was validated for qualitative assessment of
Candida albicans
(pathogenic fungi) by using a combination of L-proline β-naphthylamide as the substrate and cinnamaldehyde as an indicator. Our studies reveal that the pathogenic fungi can be detected within 10 min with the limit of detection (LOD) of 0.86 × 10
6
cfu/mL. Owing to its simplicity, this facile method shows high potential and can be scaled up for developing robust paper-based devices for biomarker detection in resource-limited settings.
Graphic abstract
PDF
