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Wastewater-based surveillance of the COVID-19 pandemic holds great promise; however, a point-of-use detection method for SARS-CoV-2 in wastewater is lacking. Here, a portable paper device based on CRISPR/Cas12a and reverse-transcription loop-mediated isothermal amplification (RT-LAMP) with excellent sensitivity and specificity was developed for SARS-CoV-2 detection in wastewater. Three primer sets of RT-LAMP and guide RNAs (gRNAs) that could lead Cas12a to recognize target genes via base pairing were used to perform the high-fidelity RT-LAMP to detect the N, E, and S genes of SARS-CoV-2. Due to the trans-cleavage activity of CRISPR/Cas12a after high-fidelity amplicon recognition, carboxyfluorescein-ssDNA-Black Hole Quencher-1 and carboxyfluorescein-ssDNA-biotin probes were adopted to realize different visualization pathways via a fluorescence or lateral flow analysis, respectively. The reactions were integrated into a paper device for simultaneously detecting the N, E, and S genes with limits of detection (LODs) of 25, 310, and 10 copies/mL, respectively. The device achieved a semiquantitative analysis from 0 to 310 copies/mL due to the different LODs of the three genes. Blind experiments demonstrated that the device was suitable for wastewater analysis with 97.7% sensitivity and 82% semiquantitative accuracy. This is the first semiquantitative endpoint detection of SARS-CoV-2 in wastewater via different LODs, demonstrating a promising point-of-use method for wastewater-based surveillance.

Two easy-to-use, rapid, and inexpensive colorimetric-based assays for the detection of active constituent in nasal decongestant phenylephrine hydrochloride (PHP), in solution and their respective pharmaceutical preparations were reported. The assay principle depends on the diazotized sulfadimidine (DSDM) coupling with PHP active pharmaceutical compound under alkaline conditions to produce a colored azo-dye product. A UV/VIS spectrophotometry method was utilized to monitor the color absorbance change at 460 nm, with a linear calibration graph in the concentration range of 1-20 mg L-1 and a limit of detection of 0.22 mg L-1 and limit of quantification of 0.72 mg L-1. A comparison was done using a paper-based microfluidic analytical device (µPADs) and color intensity change was measured using a Samsung note 9 camera to capture digital images and Image J software to analyze the color intensity development. A linear trend was observed above approximately 10 mg L-1. Thus, paper-based microfluidic analytical devices (µPADs) can be used as an alternative platform to conventional methods to perform a semi-quantitative PHP drug analysis. The proposed method was applied for the determination of PHP in commercial pharmaceutical preparations. KEY WORDS: Phenylephrine hydrochloride, Spectrophotometry, Paper-based microfluidic analytical devices (µPADs), Pharmaceutical preparations, Colorimetric detection Bull. Chem. Soc. Ethiop. 2022, 36(4), 727-736. DOI: https://dx.doi.org/10.4314/bcse.v36i4.1 &nbsp

Paper microfluidics has been extensively exploited as a powerful tool for environmental and medical detection applications. Both flow delay and compatibility with either polar or non-polar reagents are indispensable for the automation of detections requiring multiple reaction steps. This article reports the systematic studies of a 3D-printing protocol, characterization, and application of both the partially and fully penetrated polydimethylsiloxane (PDMS) barriers for flexible flow control in paper microfluidics. The physical parameters of PDMS barriers printed using a simple liquid dispenser were found related to the printing pressure, speed, diffusion time after printing, baking temperature, and PDMS viscosity. The capability of PDMS barriers to confine the flow of non-polar solvents was demonstrated using oil flow in both wax-and PDMS-surrounded channels. It was identified that the minimum width of channels to prevent leakage was 470 ± 54 μm, which was as narrow as that fabricated using stamps from lithography. Both the partially penetrated barriers (PPBs) and constriction channels were of the capability to delay flow in paper microfluidics. Additionally, an in silico investigation led to the further understanding that the reduction of channel cross-section resulting from PPBs was the primary reason for flow delay. Our results suggest that increasing the penetration depth of the barriers is more efficient in delaying flow than increasing the PPB length. Finally, devices with four inlet channels and 0-6 PPBs across each channel were successfully applied in flow delay for sequential fluid delivery. These results improve the understanding of the major factors, affecting the 3D PDMS barrier fabrication and the resulting flow control in paper microfluidics, providing practical implications for applications in various fields.

Paper aging and protection processes play an essential function in the preservation of library collections and archives. In this study, some physical-mechanical properties of paper samples from XXth century books (private collections), such as pH acidity, tensile strength, and modulus of elasticity, as well as optical properties, such as absolute change in yellowness, were examined before and after treating them with hydroxyapatite nanoparticles (HAp). Accelerated light aging was also evaluated and discussed. The treatment with HAp nanoparticles increased the paper’s pH to slightly alkaline values (approximately pH 8). Washing and treating the paper improved its mechanical properties compared to untreated paper; the tear length increased by 35% and the modulus of elasticity increased by 56%. That the treated and aged samples are more elastic than the original samples demonstrates that HAp nanoparticles consolidated the cellulose fibers. Additionally, particle morphology, size, composition and size distribution were assessed via image analysis using scanning electron microscopy (SEM-EDX), atomic force microscopy (AFM), and the ImageJ processing program.

Recognising the relevance of learning Geometry, and in particular 3D Geometry, this study aims to discuss the contributions that digital technology and paper and pencil approaches can bring to students’ learning. We seek, therefore, to identify the differences between the two approaches, and specifically: What factors are relevant in one and the other approach? What does one approach facilitate over the other? A quantitative and a qualitative and interpretive methodology was adopted, and based on a didactic intervention, the students' resolutions of the proposed tasks were analysed. The results obtained show that the experience and prior knowledge of the students with each of the solids involved seems to be decisive in the approach with paper and pencil. However, technology emerges as an enhancing resource when prior knowledge is more fragile. The study also shows differences between the representations supported by the two resources, suggesting the mobilisation of different knowledge by the students in relation to each of the resources., This work was partially funded by CIEd – Centro de Investigação em Educação, Instituto de Educação, Universidade do Minho, projects UIDB/01661/2020 and UIDP/01661/2020, through national funds of FCT/MCTES-PT; and by national funds through FCT – Foundation for Science and Technology, I.P., within the scope of the project PTDC/CED-EDG/32422/2017.

We report a non-invasive and multi-analytical physico-chemical method for the characterization of paper artworks, able to identify sizing, inks, and glues and to quantify oxidative degradation by-products. The proposed methodology is mostly carried out in situ by using easy-to-use and cheap portable instrumentation for the acquisition of multispectral images, punctual ultraviolet-visible-near infrared fiber-optics reflectance spectroscopy (FORS) and punctual fiber optics fluorescence spectroscopy. Further analytical information is provided by non-invasive in-situ sampling of paper surface by using soft latex sponges, making possible laboratory chromatographic and infrared spectroscopic analyses on the aqueous sponge extracts. The proposed diagnostics method was applied to two 17th century letters written by St Francis of Sales (1567-1622), collected at the Chigi Palace in the town of Ariccia (Italy). Results show an intense oxidative degradation of the letters, also localized in water spots, and the presence of carboxylic acids by-products. Analysis of FORS spectra provided the concentration of chromophores in the paper substrate. The diagnostic method allowed the identification of gelatin sizing, the presence of starch glue in specific areas of the letters and the type of ink used in the text. Our diagnostic approach aims to offer to conservator-restorer a characterization of a paper artwork, that can be applied to other, for a correct planning of conservation interventions.

Traditional papermaking is based on the use of an aqueous suspension consisting of cellulose fibres obtained by processing wood, non-wood plants or waste paper. With growing environmental concerns regarding deforestation and CO2 production, the paper industry has been always looking for new sources of non-wood pulp that would produce papers of similar quality to those made from wood pulp. Cereal straw from wheat, barley or triticale crops that remains on fields as a residue after grain harvesting has proven to be a good substitute for virgin wood fibres needed in the production of recycled paper. In this study, the quality of printed text on recycled paper with added straw pulp is evaluated mainly based on the line and edge characteristics of the printed letters. For this purpose, three types of laboratory paper substrates were first prepared using recycled wood pulp with the addition of 30% wheat, barley, or triticale straw pulp. The same letter pattern was printed with black ink on each paper substrate at a standard size of 12 pt with two common typefaces: Arial and Times New Roman. The quality of the printed letters was assessed through the measured print quality parameters such as blurriness, raggedness, fill and contrast. The resulting measurements were compared with the results obtained on the reference and control samples made exclusively from recycled wood pulp as a substrate from laboratory and commercial production. In terms of fill and contrast values, the uniformity of lines printed on the recycled papers with added straw pulp is the same or very similar to the reference and control papers. Letters printed in Arial (sans-serif) typeface show slightly better reproduction quality than letters printed in Times New Roman (serif) typeface. The measured parameters blurriness and raggedness of all laboratory-made paper substrates (with and without straw pulp) had similar values between 0.17 mm and 0.20 mm, resulting in a very similar reproduction quality compared to the reference paper substrate.

This studies paper posted in Conference proceeding identifies the elements that make a contribution to the fulfillment of librarians as lively researchers. Research fulfillment is commonly aligned with productiveness and output, and the authors are consequently interested by know-how the elements that inspire studies productiveness. This fills an opening with inside the literature on librarians as researchers. This paper present research productivity of LIS professionals in Kavyitri Bahinabai Chaudhari North Maharashtra University, Jalgaon Affiliated Colleges in Nandurbar District, during 2009-10 to 2018-19. This research paper covers the analysis of this paper is Year wise Research Productivity, research paper publication in state, national and International level conference proceedings, Gender-wise trend, Age-wise trend, Area-wise trend, Author trend, and Language-wise trend published in Conference Proceeding. A structured questionnaire was used to collect the information.

Understanding the long-term impact of scientific findings requires understanding the dynamic process of new research fields' formation. In new research fields, slow-cited papers (SCP) and the awakeners (AW) are more likely to exist, indicating explorers revisited underrated but significant past papers relocating the findings in the new paradigm. This study acquired SCP-AW pairs located in the integrated point of two different research fields using the inheritance of clusters. We found that research field integration, including SCP-AW pairs, was diverse but followed a similar pattern throughout history, generating an equal mix of SCP and AW fields. The recent trend toward more AW-centric disciplinary combinations supports the belief that field integration will become increasingly technology-driven in the coming years.

Ascorbic acid (AA) is the most important water-soluble organic biomolecule with antioxidant properties, known as vitamin C in many foods and beverages. The number of different methods developed for the determination of antioxidant properties of foods is increasing. Paper-based microfluidic analytical devices (µPADs) have been applied in the development of fast, simple, and cost-effective field analyzes in recent years. These developed analyzes are used as an alternative to laboratory-equipped qualitative and quantitative analyzes. In this study, a paper-based colorimetric method was applied for the determination of ascorbic acid. Geometric shapes with hydrophobic barrier were created on Whatman filter papers with the help of a wax pen. Using the principle of reduction of the AgNO3 solution in the presence of antioxidants in these shapes, the images of the color transformations were recorded with the help of a smartphone camera. ImageJ software was used in the image processing to determine the concentrations of standard AA solutions. Linear calibration curves for AA concentrations in the 0,2 to 1,0 mM range were obtained in grayscale and RGB (Red-Green-Blue) values. The coefficient of determination of the calibration curves (R2), respectively; 0,9389 for grayscale, 0,9728, 0,9628, and 0,8859 for Red, Green, and Blue channels. High-Performance Liquid Chromatography (HPLC) was used as a standard method to compare with the paper-based method. Freshly squeezed orange juice was used for the determination of ascorbic acid in the real food sample. The ascorbic acid value determined in orange juices by HPLC and colorimetric methods were statistically compared., Askorbik asit (AA), birçok yiyecek ve içecekte C vitamini olarak bilinen ve antioksidan özelliği olan en önemli suda çözünür organik biyomoleküldür. Gıdaların antioksidan özelliklerinin belirlenmesine yönelik geliştirilen farklı yöntemlerin sayısı giderek artmaktadır. Kağıt tabanlı mikroakışkan analitik cihazlar (µPAD'ler), son yıllarda hızlı, basit ve uygun maliyetli saha analizlerinin geliştirilmesinde uygulanmaktadır. Geliştirilen bu analizler, laboratuar donanımlı kalitatif ve kantitatif analizlere alternatif olarak kullanılmaktadır. Bu çalışma kapsamında, askorbik asit tayini için kağıt tabanlı kolorimetrik bir yöntemin uygulaması yapılmıştır. Whatman filtre kağıtları üzerinde vaks kalem yardımıyla hidrofobik bariyerli geometrik şekiller oluşturulmuştur. Bu şekillerin içerisinde AgNO3 çözeltisinin antioksidan varlığında indirgenmesi prensibi kullanılarak meydana gelen renk dönüşümlerinin görüntüleri akıllı telefon kamerası yardımıyla kaydedilmiştir. Standart AA çözeltilerinin konsantrasyonlarının tespiti için ImageJ yazılımı, görüntü işleme prosesinde kullanılmıştır. 0,2 ile 1,0 mM aralığında AA konsantrasyonları için doğrusal kalibrasyon eğrileri gri ölçek ve RGB (Kırmızı-Yeşil-Mavi) değerlerinde elde edilmiştir. Kalibrasyon eğrilerinin determinasyon katsayısı (R2) sırasıyla; gri ölçek için 0,9389, Kırmızı, Yeşil ve Mavi kanallar için 0,9728, 0,9628 ve 0,8859 olarak hesaplanmıştır. Yüksek Performanslı Sıvı Kromatografisi (HPLC) standart bir yöntem olarak kağıt tabanlı yöntem ile karşılaştırmak için kullanılmıştır. Gerçek gıda örneğinde askorbik asit tayini için taze sıkılmış portakal suları kullanılmıştır. HPLC yöntemiyle kolorimetrik yöntem sonucu portakal sularında belirlenen askorbik asit değerleri istatistiksel olarak karşılaştırılmıştır.

Supplemental information associated with this article can be found online: https://doi.org/10.1016/j.trechm.2022.03.005, The implementation of a wide diagnostic campaign to diagnose cancer early could save millions of lives and billions of dollars every year. Unfortunately, cancer diagnosis is extremely complicated and current approaches rely on the use of expensive equipment and specialized personnel, which hamper their deployment in low- and middle-income settings. Here, we analyze the technical challenges that must be overcome to achieve precise cancer diagnostics and we describe how such hurdles have limited the development of point-of-care (PoC) sensors. Then, we explain why we believe recent achievements in the field of paper-based sensors could allow their use as widely available sensing platforms for cancer detection. Finally, we present our vision of what should be done in order to make paper-based sensors widely used diagnostics platforms for cancer., We acknowledge Agencia Estatal de Investigación (AEI) and Fondo Europeo de Desarrollo Regional (FEDER) for the project MAT2017-87202-P and through the Severo Ochoa Centres of Excellence Program under Grant SEV2201320295. This work is also funded by the CERCA Program/Generalitat de Catalunya. C. Pa. acknowledges support from the Spanish Ministry of Science and Innovation and State Research Agency through the “Centro de Excelencia Severo Ochoa 2019-2023” Program (CEX2018-000806-S). This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2020 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. C.Pe. was recipient of a fellowship supported by a doctoral advanced training (call NORTE-69-2015-15) funded by the European Social Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. A.I. was supported by PROBIST postdoctoral fellowship funded by the European Research Council (Marie Skłodowska-Curie grant agreement no. 754510., info:eu-repo/semantics/publishedVersion

This work presents a unique approach to the design, fabrication, and characterization of paper-based origami robotic systems consisting of stackable pneumatic actuators. These paper-based actuators...