Paper as a novel material platform for devices

Research on microfluidic devices for biological analysis has progressed sufficiently to be developed into point-of-care diagnostics products. The goal of this thesis is to improve multiple aspects of capillary-driven microfluidic devices. In particular, the objective is to provide devices with a fast time to result, that are simple to use (one-step), that can be portable, that accept a variety of samples, that operate reliably, that provide a range of detection signals, that are mass manufacturable at lost cost, and that are able to detect medically relevant biological molecules. First, we survey the evolution of microfluidic research into portable medical diagnostic devices. By looking at several gaps and opportunities in current medical diagnostics, we provide an overview of research topics that have the potential to shape the next generation of point-of-care diagnostics. Specifically we explain technologies in the order of sample interacting with different components of a device. We investigate the materials, surface treatments, sample processing, microfluidic elements (such as valves, pumps and mixers), receptors and analytes and the integration of these components into a device that might conceivably leave the laboratory for the hands of consumers. The knowledge of what is important in a point-of-care diagnostics device was used to develop a proof of concept. One of the main challenges is to make microfluidics easy to use by incorporating reagents and microfluidic elements. We integrated a number of functional elements on a chip such as a sample collector, delay valves, flow resistors, a deposition zone for detection antibodies (dAbs), a reaction chamber sealed with a polydimethylsiloxane (PDMS) substrate, and a capillary pump and vents. We further incorporated capture antibodies (cAbs), detection antibodies (dAbs) and analyte molecules for making one-step immunoassays. The integrated microfluidic chip requires only the addition of sample to trigger a sequence of events controlled by capillary forces to detect C-reactive protein (CRP), a general inflammation and cardiac marker, at a concentration of 1 ng mL-1 within 14 min using only 5 µL of human serum. The proof-of-concept is extended to easily modify several assay parameters such as the flow rates and the volumes of samples for tests, and the type of reagents and receptors for analytes. The multiparametric microfluidic chip is capable of analyzing 20 µL of human serum in 6 parallel flow paths in a range of flow rates with filling times from 10 minutes to 72 minutes. The asymmetric release of dAbs in a stream of human serum is compensated by a Dean flow mixer. Sample is equally split into 6 reaction chambers connected to flow resistances that vary flow rates, and the kinetics of capture of analyte-dAb complexes. The increased incubation time leads to a fourfold increase in detection signal in the reaction chamber with the longer incubation time. Furthermore, integrating reagents and controlling their release is essential for simple and accurate point-of-care diagnostic devices. We developed reagent integrators (RIs) to release small amounts of dried reagents (ng quantities and less) into microliters of sample. Typical RIs are composed of an inlet splitting into a central reagent channel, with a high hydraulic resistance, and two diluter channels. Reagents spotted in the central channel reconstitute in sample during filling and merge at the end of the RI with a dilution factor corresponding to the relative hydraulic resistance of the channels forming the RI. RIs are simple to integrate in lateral flow assays and provide a great degree of control over reagent integration and dissolution. Finally, the one-step capillary-driven microfluidic chips have the ability to not only detect a variety of proteins, but also to detect nucleic acids for molecular diagnostics. These devices, especially if manufactured in low cost plastic and used with portable fluorescence readers, have the potential to identify a wide variety of health conditions and to enable truly decentralized medical diagnostics.

Microfluidic devices are a good example of the collaboration of chemical, biological, and engineering sciences. Microfluidic devices emerge as an in fluent technology which provides an alternative to conventional laboratory methods. These devices are employed for the precise handling and transport precise quantities of drugs without toxicity. This system is emerging as a promising platform for designing advanced drug delivery systems and analysis of biological phenomena on miniature devices for easy diagnosis. Microfluidics enables the fabrication of drug carriers with controlled geometry and specific target sites. Microfluidic devices are also used for the diagnosis of cancer circulating tumor cells. In the current review, different microfluidic drug delivery systems and diagnostic devices have described.

A transformation of the healthcare industry is necessary and imminent: hospital-centered, reactive care will soon give way to proactive, person-centered care which focuses on individuals' well-being. However, this transition will only be made possible through scientific innovation. Next-generation technologies will be the key to developing affordable and accessible care, while also lowering the costs of healthcare. A promising solution to this challenge is low-cost continuous health monitoring; this approach allows for effective screening, analysis, and diagnosis and facilitates proactive medical intervention. Urine has great promise for being a key resource for health monitoring; unlike blood, it can be collected effortlessly on a daily basis without pain or the need for special equipment. Unfortunately, the commercial rapid urine analysis tests that exist today can only go so far-this is where the promise of microfluidic devices lies. Microfluidic devices have a proven record of being effective analytical devices, capable of controlling the flow of fluid samples, containing reaction and detection zones, and displaying results, all within a compact footprint. Moving past traditional glass- and polymer-based microfluidics, paper-based microfluidic devices possess the same diagnostic ability, with the added benefits of facile manufacturing, low-cost implementation, and disposability. Hence, we review the recent progress in the application of paper-based microfluidics to urine analysis as a solution to providing continuous health monitoring for proactive care. First, we present important considerations for point-of-care diagnostic devices. We then discuss what urine is and how paper functions as the substrate for urine analysis. Next, we cover the current commercial rapid tests that exist and thereby demonstrate where paper-based microfluidic urine analysis devices may fit into the commercial market in the future. Afterward, we discuss various fabrication techniques that have been recently developed for paper-based microfluidic devices. Transitioning from fabrication to implementation, we present some of the clinically implemented urine assays and their importance in healthcare and clinical diagnosis, with a focus on paper-based microfluidic assays. We then conclude by providing an overview of select biomarker research tailored towards urine diagnostics. This review will demonstrate the applicability of paper-based assays for urine analysis and where they may fit into the commercial healthcare market.

GeTe Thermoelectrics

Background: This study aims to employ Discriminant Analysis to examine the differentiation between state-level volleyball players categorized as "High Performance" and "Low Performance,". Objectives of the Study: 1. To characterize the level of anthropometric, functional and volleyball skill of volleyball players on the basis of high and low performance. 2. To develop discriminate model for classifying a State level Volleyball Players into High or low – performance categories. Materials and methods: In this study 72 male state-level volleyball players from various volleyball academies were selected, their age ranging between 19-25 year, all were selected by using purposive sampling. These selected subjects had been alienated into two group i.e. high and low performance group. Anthropometrical variables were measured by anthropometric kit, General volley pass playing ability, serving skill, passing skill and AAHPER serving test Numerical was measured by Brady’s wall volleying test, AAHPER passing test, AAHPER set up test and AAHPER serving test respectively. Leg Explosive Power, Shoulder Strength, Agility, Abdominal strength measured Standing broad Jump, Medicine ball throw Distance, 10x4 shuttle run, Sit-ups respectively. Results: Box’s M test value is 1.357 is not significant it means that the assumption of homogeneity of variance/covariance matrices is not violated. Canonical correlations of function 1 is.639 indicates 40.83% (=.639) of the variation in the two different group. Wilks' Lambda value is.807 which indicates the model is good as only 65.12% in function 1 variability is not explained by the model. The value of chi-square is 15.294 shows the significance of Wilks Lambda. Group means for high and low group means are.482 and -.482 which are group centroid. (78.4%) cases were correctly classified by the model which is quite high, therefore the model can be considered as valid. Conclusions: Discriminant function for the State level volleyball players on the basis of the performance (High and Low) is Z= -5.331 +.401× (Set Up).

The purpose of this study was to take the gauge of the importance-performance of the clothing store attribute in the department store. The survey was administered to customers of department stores in Deajeon city and frequency analysis, factor analysis, reliability analysis, and importance-performance analysis were used to analyze the data of 37 clothing store attributes. The findings of this study were as bellows: 1. 8 factors were distracted from 37 clothing store attributes by factor analysis (Factor 1: goods, Factor 2; store's facility and environment, Factor 3; salesman and service, Factor 4; brand, Factor 5; price, Factor 6; store's atmosphere, Factor 7; convenience of the transportation and access, Factor 8; promotion and advertisement) 2. as results of importance-performance analysis, 10 attributes were shown in area I (high importance and high performance) which needed a strategy of Keep Up the Good Work, 6 attributes in area II (low importance but high performance) fitted a strategy of Possible Overkill, 12 attributes in area III (high importance but low performance) corresponded to a strategy of Concentrate Here, and finally a strategy of Low Priority was needed to 9 attributes in area IV (low importance and low performance).

We might be at the turning point where research in microfluidics undertaken in academia and industrial research laboratories, and substantially sponsored by public grants, may provide a range of portable and networked diagnostic devices. In this Progress Report, an overview on microfluidic devices that may become the next generation of point-of-care (POC) diagnostics is provided. First, we describe gaps and opportunities in medical diagnostics and how microfluidics can address these gaps using the example of immunodiagnostics. Next, we conceptualize how different technologies are converging into working microfluidic POC diagnostics devices. Technologies are explained from the perspective of sample interaction with components of a device. Specifically, we detail materials, surface treatment, sample processing, microfluidic elements (such as valves, pumps, and mixers), receptors, and analytes in the light of various biosensing concepts. Finally, we discuss the integration of components into accurate and reliable devices.

The recent cases of COVID-19 have brought the prospect of and requirement for point-of-care diagnostic devices into the limelight. Despite all the advances in point-of-care devices, there is still a huge requirement for a rapid, accurate, easy-to-use, low-cost, field-deployable and miniaturized PCR assay device to amplify and detect genetic material. This work aims to develop an Internet-of-Things automated, integrated, miniaturized and cost-effective microfluidic continuous flow-based PCR device capable of on-site detection. As a proof of application, the 594-bp GAPDH gene was successfully amplified and detected on a single system. The presented mini thermal platform with an integrated microfluidic device has the potential to be used for the detection of several infectious diseases.

The objectives for this study were to 1) determine the relationship between sexual performance class and lambs sired in a competitive mating environment, and 2) determine whether the male-oriented ram test is valid. Fifteen 2- to 3-yr-old whitefaced rams classified as female-oriented, with high or low sexual performance, or classified as male-oriented were used in a multiple-sire breeding arrangement. Five groups of approximately 200 ewes each were exposed for 21 d to 3 rams per group consisting of 1 ram from each class. Rams were blocked for sexual class, and those with close genetic relationship were assigned to different pens. Genomic DNA was prepared from blood collected from 15 rams, 934 ewes, and 1,757 lambs. Up to 4 microsatellite markers were used to determine a lamb's sire. Of 884 ewes with identifiable lambs (known sires), 178 ewes had single lambs, 408 had multiples sired by 1 ram, and 298 had multiples sired by more than 1 ram. The sexual partner preference test used to identify male-oriented rams did not absolutely reflect their sexual performance during competitive breeding. In contrast to only mounting and servicing males in preference tests before breeding, male-oriented rams sired 480 lambs from 330 ewes. Serving capacity tests predicted sexual performance of high and low sexual performance rams. High performance rams impregnated more ewes (499 vs. 258; P < 0.05) and sired more lambs (756 vs. 357; P < 0.05) than did low performance rams, respectively. Low performance and male-oriented rams did not differ for ewes impregnated or lambs sired. We conclude that 1) sexual partner preference tests used to classify male-oriented rams were not absolute in reflecting their breeding performance in a competitive breeding environment; 2) serving capacity tests predicted that high performance rams would breed more ewes than low performance rams and sire more lambs than either low performance or male-oriented rams; and 3) under the conditions of this study, low performance and male-oriented rams did not have an adverse impact on the overall breeding outcome. Combined, low performance and male-oriented rams sired 81 more lambs than did high performance rams, but this required twice as many rams to obtain approximately equal breeding results. Therefore, we suggest that serving capacity tests should be used to select high performance rams, reduce number of rams with marginal sexual performance, and make decisions on ram numbers needed.

Community Health Centers’ Performance in Cancer Screening and Prevention

We evaluate a theory of the effects of publishing performance information on citizens' collective voice to local providers about public service performance and the perceptions and attitudes that influence their voice. Field experiments show that information about low absolute and relative performance of local government household waste recycling services lowers citizens' perceptions of performance, and information about high absolute and relative performance raises perceived performance. Relative information makes citizens judge local providers as being more responsible for outcomes in the case of high performance, suggesting that systems for comparative performance reporting increase local accountability for outcomes. Negativity bias is evident, with information about low absolute performance reducing citizens' satisfaction but information about high performance not raising satisfaction. Information about low performance did not trigger collective voice protest behaviour as hypothesized, suggesting that providers who need citizens' collective voice the most do not get it.

Automation Highlights from the Literature

The past few decades has witnessed an intensive drive in the development of microfluidic technologies and devices that have tremendous applications in diverse sectors from defence to healthcare. Entire analytical protocols, including sample pretreatment, sample/reagent manipulation, separation, reaction, and detection can be performed significantly quicker on these miniaturised and compact devices. A broad range of existing and new materials from silicon, glass, polymers, and paper have been demonstrated as viable compatible materials for creating advanced and low-cost microfluidic devices, with embedded micrometre-sized elements, to provide unique and often combined functionalities for microfluidic processing. Based on the category of materials, fabrication techniques and examples of applications will be discussed in this chapter. Factors influencing the choice of material, cost of processing, and suitability of specific applications are included. The integration of microfluidic devices and detection technologies suggests a solid understanding of fabrication procedures and their limitations is essential to the development of commercial microfluidic devices.

Silicon dioxide (SiO2) is ubiquitous in biomedical diagnostics and other applications as a capture medium for nucleic acids and proteins. Diagnostic devices have seen rapid miniaturisation in recent years, due to the increased demand for portable point-of-care diagnostics. However, there are increasing challenges with incorporating SiO2 nanostructures into diagnostic devices, due to the complexity of nanostructured SiO2 synthesis, often involving etching and chemical vapour deposition under high vacuum conditions.We report a novel and straightforward method for deposition of high-quality, nanoscale SiO2 films and 3D SiO2 structures using thermal decomposition of polydimethylsiloxane (PDMS), in a furnace at atmospheric pressure at 500 °C. This method allows individual nanometre controllability of conformal pinhole-free layers on a variety of materials and morphologies. The temperature ramp rate is a key factor in determining the SiO2 deposit morphology, with slower ramp rates leading to highly conformal 2D films and faster ones yielding 3D nanodentrite structures. For the 2D films, the film thickness, as determined by spectroscopic ellipsometry and confirmed by SEM data, is shown to correlate excellently with initial PDMS source material mass in the thickness range 0.8–18 nm. Fits to ellipsometry models confirm that the refractive index of the deposited film matches the expected value for SiO2, while electrical breakdown measurements confirm that the breakdown strength of the films is comparable to that of high-quality thermal oxides. Depositions on high aspect ratio ZnO nanostructures are shown to be highly conformal, leading to core-shell ZnO-SiO2 nanostructures whose shell thickness is in excellent agreement with the expected values from deposition on planar substrates. At faster ramp rates an abrupt morphological transition is seen to a deposit which displays a 3D nanodentrite morphology. The possibilities for applications of both morphologies (and core-shell combinations with other nanostructured materials) in biosensing and related areas are briefly discussed, and the DNA capture capabilities of each nanostructure are measured. The high aspect ratio nanodendrite structures allow for significant DNA capture within microfluidic devices in the presence of low DNA concentrations, with a maximum average capture efficiency of 43.4 % achieved in the presence of 10 ng/mL of DNA, which is an improvement by a factor of ∼ 3 over planar Si surfaces. Improvements by factors of >10 over planar surfaces were achieved at higher DNA concentrations of 100 and 1000 ng/mL.

Integration of isothermal amplification methods in microfluidic devices: Recent advances