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Abstract In this study, zinc oxide (ZnO) nanoparticles were prepared and modified using a wet chemical method with different concentrations of Ag and Cu nanoparticles. The objective was to improve the mechanical, optical, and antibacterial properties of the coated paper by using the prepared pigments. The long-term antimicrobial effects of the coated paper were evaluated over 25 years. The successful synthesis of a hexagonal structure of ZnO nanoparticles decorated with spherical Ag and Cu nanoparticles ranging from 20 to 50 nm was confirmed using X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and transmission electron microscopy (TEM). By increasing the concentrations of Ag and Cu from 0.01% to 1.0%, the mechanical properties of the coated paper were enhanced. The tensile strength reached a maximum of 6.77 kN/m and 7.03 kN/m, elongation increased to 1.69% and 1.70%, tensile energy absorption improved to approximately 77 and 80 J/m2, and burst strength rose to 218 and 219 kPa, respectively. The use of Ag-modified ZnO maintains the optical properties, while Cu-modified ZnO reduces brightness and whiteness without affecting opacity. The antimicrobial inhibition activity was improved with higher silver (Ag) and copper (Cu) content. The formulations containing 1% Ag/ZnO and 1%Cu/ZnO showed long-lasting antibacterial effects against gram-positive Staphylococcus aureus bacteria. Even after 25 years of aging, they maintained inhibition rates of 92.2% and 62.2%, respectively. The molecular docking and GeneMANIA analysis revealed the potential of ZnO, Ag-modified ZnO, and Cu-modified ZnO nanoparticles to disrupt the S. aureus cell wall biosynthesis pathway by targeting the MurA enzyme and associated cell wall synthesis genes.

Abstract Concrete’s widespread use in construction is increasing due to urbanization and population growth. While it offers durability and strength, its production poses environmental challenges. Researchers and global initiatives are working towards more sustainable concrete production methods and effective waste management, particularly for paper waste (WPA) and polyethylene terephthalate waste (PET). This study aims to investigate the effects of waste paper aggregate (WPA) on the flow time, compressive strength, flexural strength, and thermal conductivity of mortars. Furthermore, it explores the potential of polyethylene terephthalate (PET) to enhance the compressive and flexural strengths of these mortars. To conduct this study, the materials were characterized using EDX spectroscopy and SEM analysis. Gwyddion software was employed to conduct a comprehensive analysis of the grain segmentation and microstructural characteristics of the WPA mortars. Subsequently, four distinct mixtures were selected for further investigation. The first mixture involved substituting sand with various percentages of waste paper aggregate (WPA) (1–4%) without PET. The second mixture included WPA (1–4%) and 5% PET. Due to the ineffective plasticizer in the first two mixtures, the third mixture replaced 20% of quarry sand with dune sand (DS) while maintaining the same percentages of WPA and PET as in the previous mixtures. The results indicate that mortars RM1 (0% WPA + 0% PET) and RM2 (0% WPA + 0% PET + 20% DS) demonstrated the best flow time. This suggests that incorporating WPA and PET into the mortar mix can negatively impact its workability, making it more challenging to handle, shape, and apply. Sample PW4, composed of 4% WPA and 0% PET, displayed a significant increase in compressive strength from 46.36 MPa to 49.81 MPa and flexural strength from 10.5 MPa to 11.47 MPa, indicating that incorporating WPA into the mortars can enhance resistance to both compressive and flexural strengths. This same mixture, PW4, demonstrated that the mortars are poor conductors of heat and would be more effective as thermal insulators. Grain segmentation of WPA mortars using Gwyddion software revealed that shorter WPA fibers tend to align with the width, while longer WPA fibers tend to align with the length of the section.

Abstract Expansive soils have a high tendency for volume change in case of fluctuations in moisture content, potentially causing significant damage to light structures, particularly road pavements. This paper investigates the influence of waste paper sludge ( $$\:WPS$$ ) as an alternative sustainable stabilizer on the volume change behavior of expansive road subgrade soils of different origins. For this purpose, $$\:WPS$$ was added to the expansive soils at ratios of 3%, 6%, 9%, 12%, and 15% by dry weight of the soils. A series of Atterberg’s limit, swelling, shrinkage, compaction, and consolidation tests were performed on pure soils and soil specimens with $$\:WPS$$ to attain a comprehensive understanding of the role that $$\:WPS$$ plays in the volume change behavior of expansive soils. The experimental test results showed that the addition of $$\:WPS\:$$ led to a considerable decrease in the plasticity and swell-shrink potentials of subgrade soils. The consolidation settlement of expansive road subgrades was also reduced to some extent with $$\:WPS$$ . Moreover, the statistical analysis of the test data indicated a significant relationship among different swelling-shrinkage parameters. The experimental results presented here suggest that the $$\:WPS$$ may be a cost-effective, environmentally friendly, and sustainable stabilizer to reduce the volume change sensitivity of expansive road subgrade soils.

Abstract Flax (Linum usitatissimum) is a bast fiber plant known for its long fibers, making it an excellent source of pulp for paper production. In Ethiopia, flax is primarily cultivated for oil, with the residual straw utilized for papermaking. This study focuses on pulping flax straw using the Kraft process and investigates its chemical composition, proximate analysis, and morphological properties. The proximate analysis revealed an ash content of 4.13% and moisture content of 11%. Chemical composition analysis showed cellulose at 51.34%, hemicellulose at 25.20%, lignin at 14.12%, ash at 4.13%, and extractives at 5.21%. The morphological properties included a fiber length of 1.41 mm, diameter of 16.78 μm, lumen width of 9.45 μm, and cell wall thickness of 3.77 μm. Flax straw exhibited an acceptable Runkel ratio (0.8) and flexibility coefficient (56.32), placing it within the range of non-wood fibers. SEM analysis of the pulp’s morphology was conducted to assess fiber structure, including the presence of cracks. Pulp quality and length are directly linked to paper strength. Various pulping conditions were studied using a full-factorial design, with optimum conditions being 10% alkaline, 131.74°C, and 120 min of cooking time, yielding a pulp with a Kappa number of 10.45 and a yield of 40.56%. The resulting paper demonstrated standard tensile, tearing, and burst strengths, indicating that flax straw is a promising raw material for paper production.

Abstract Electrochemical analysis of glucose monitoring without painful blood collection provides a new noninvasive route for monitoring glucose levels. Thus, in this study, biobased cellulosic papers (methylated and phosphorylated one) based glucose monitoring sensor is developed. To achieve high hydrophilicity, microfibrillated cellulose (MFC) were functionalized using hexokinase mediated phosphorylation (–OH to – $$\text{SO}_{3}^{2-}$$ ). The instinctive increased surface charge density from 36.2 ± 3.4 to 118.4 ± 1.2 µmol/g and decrease contact angle (45°–22°) confirms the increased hydrophilicity of paper. Furthermore, functionalized phos-MFC paper increase the capillary flow of sweat, required low quantity (1 µl) of sweat for accurate analysis of glucose level. Additionally, chemically induced methyl groups (–CH3) make the sensor more barrier to other chemicals. In addition, a multilayer patch design combined with sensor miniaturization was used to lead to an increase in the efficiency of the sweat collection and sensing processes. Besides, this paper sensor integrated with artificial transdermal drug delivery unit (agarose gel as skin) for monitoring glucose levels in sweat. The patch monitoring system increase the accuracy of sensing with fluctuation in sweat vol. (1–4 µl), temperature (20–70 °C), and pH (4.0–7.0). In addition, temperature dependency artificial transdermal delivery (within agarose gel) of drug metformin agrees the measurement accuracy of sensor, called “switch system” without any error. As a result, the reported MFC paper based multi-patch disposable sensing system provides a novel closed-loop solution for the noninvasive sweat-based management of diabetes mellitus.

Abstract The pulp and paper industry generates vast quantities of paper sludge, posing significant environmental challenges due to its disposal in landfills or incineration. This study explores the potential of valorizing paper sludge by incorporating it into particleboard production. It aims to optimize sludge content and particle size to enhance board properties—a novel approach to waste management in the wood composites industry. Through systematic variation of sludge content (0–25%) and particle size ( 2 mm), we assessed the mechanical and physical properties such as internal bond strength (IB), modulus of rupture (MOR), modulus of elasticity (MOE), water absorption (WA), and thickness swelling (TS). The findings indicate that incorporating paper sludge at moderate levels (5–15%) with optimized particle sizes (

Abstract This work proposed an approach to multi-component non-metallic materials, namely regular polygonal paper honeycomb sandwich tubes filled with polyethylene (PE) foam, and focused on the influence of drop impact parameters and structural parameters on the deformation characteristics and energy absorption of the filled tubes. Axial drop impact tests were employed to exert drop impact loading on cross-sections of the specimens with a square drop weight. The results showed that the X-direction filled tube (X-DFT) had a higher crushing strength and yield strength than that of the Y-direction filled tube (Y-DFT). As the tubular cross-section edge number of the filled tube increased, the specific energy absorption (SEA) and specific total efficiency (STE) decreased. Under the same axial drop impact loading conditions, the SEA and STE of the X-DFT were superior to those of the Y-DFT. As the edge number of the tubular cross-section or the tubular length ratio increased, the SEA and STE of the filled honeycomb tube decreased significantly. While the impact energy increased, the SEA and STE of the filled tubes increased approximately linearly. This work investigated the influence of drop-impact and structural parameters on deformation characteristics and energy absorption. It is expected to provide supplementary documentation for the advancement of cushion protection technology and the optimization of product structure.

Abstract Nucleic acid amplification testing has great potential for point-of-need diagnostic testing with high detection sensitivity and specificity. Current sample preparation is limited by a tedious workflow requiring multiple steps, reagents and instrumentation, hampering nucleic acid testing at point of need. In this study, we present the use of mixed cellulose ester (MCE) paper for DNA binding by ionic interaction under molecular crowding conditions and fluid transport by wicking. The poly(ethylene) glycol-based (PEG) reagent simultaneously provides the high pH for alkaline lysis and crowding effects for ionic binding of the DNA under high salt conditions. In this study, we introduce Paper-based Abridged Solid-Phase Extraction with Alkaline Poly(ethylene) Glycol Lysis (PASAP). The anionic mixed cellulose ester (MCE) paper is used as solid phase and allows for fluid transport by wicking, eliminating the need for pipetting skills and the use of a magnet to retain beads. Following the release of DNA from the cells due to the lytic activity of the PASAP solution, the DNA binds to the anionic surface of the MCE paper, concentrating at the bottom while the sample matrix is transported towards the top by wicking. The paper was washed by dipping it in 40% isopropanol for 10 s. After air-drying for 30 s, the bottom section of the paper (3 mm × 4 mm) was snapped off using the cap of a PCR tube and immersed in the colourimetric loop-mediated isothermal amplification (cLAMP) solution for direct amplification and colourimetric detection. The total sample processing was completed in 15 min and ready for amplification. cLAMP enabled the detection of 102 CFU/mL of Escherichia coli (E. coli) from culture media and the detection of E. coli in milk

Abstract The paper industry is a major environmental polluter due to paper waste sludge (PWS), often disposed of in hazardous ways. The techniques are employed to disposing of PWS are posing significant environmental hazards and risks to well-being. This study aims to evaluate PWS as a potential replacement for commercial adsorbents like AC and ZEO in treating stabilized leachate. Contact angle analysis of PWS was 92.60°, reveals that PWS to be hydrophobic. Batch adsorption experiments were conducted with parameters set at 200 rpm stirring speed, 120 min contact time, and pH 7. Optimal conditions for COD and NH3–N removal were identified at 120 min contact time, 200 rpm stirring speed, pH 7, and 2.0 g PWS ratio. Removal percentages for COD and NH3–N were 62% and 52%, respectively. Based on the results of the isotherm and kinetic studies, it was observed that the Langmuir and Pseudo second order (PSO) model exhibited greater suitability compared to the Freundlich and Pseudo first order (PFO) model, as indicated by higher values of R-squared (R2). The R-squared of Langmuir for COD and NH3–N were 0.9949 and 0.9919 and for Freundlich model were 0.9855 and 0.9828 respectively. Whereas the R-squared of PFO for COD and NH3–N were 0.9875 and 0.8883 and for PSO were 0.9987 and 0.9909 respectively.

Abstract Paper- and paperboard-based materials are alternatives to petroleum-based plastics in food packaging but unsuitable for their poor moisture and oil resistance. In this sense, fluorinated compounds improve water and grease repellency, though their use is controversial. This Perspective discusses main techniques to combine fluorinated compounds with paper and paperboard, including water and oil contact angles and grease resistance values, and summarizes main legal aspects in Europe and the United States.

Abstract Materials that provide dynamically tunable infrared (IR) response are important for many applications, including active camouflage and thermal management. However, current IR-tunable systems often exhibit limitations in mechanical properties or practicality of their tuning modalities, or require complex and costly fabrication methods. An additional challenge relates to providing compatibility between different spectral channels, such as allowing an object to be reversibly concealed in the IR without making it appear in the visible range. Here, we demonstrate that conducting polymer-cellulose papers, fabricated through a simple and cheap approach, can overcome such challenges. The papers exhibit IR properties that can be electrochemically tuned with large modulation (absolute emissivity modulation of 0.4) while maintaining largely constant response in the visible range. Owing to high ionic and electrical conductivity, the tuning of the top surface can be performed electrochemically from the other side of the paper even at tens of micrometer thicknesses, removing the need for overlaying electrode and electrolyte in the optical beam path. These features enabled a series of electrically tunable IR devices, where we focus on demonstrating dynamic radiative coolers, thermal camouflage, anti-counterfeiting tags, and grayscale IR displays. The conducting polymer-cellulose papers are sustainable, cheap, flexible and mechanically robust, providing a versatile materials platform for active and adaptive IR optoelectronic devices.

Abstract Sepia melanin, a biopigment extracted from the ink sac of cuttlefish, is relevant to sustainable organic electronics. In this work, we flexographically print films from an ink of Sepia melanin including shellac as a bio-sourced binder on silver electrode-patterned paper. We examine the electrical response in high humidity and ambient conditions (here the electronic conductivity is as high as 10−4 S/cm). Additionally, we study the biodegradation of the printed films and their individual constituents based on their mineralization into CO2 under composting conditions. The printed films exhibit biodegradation levels of about 97 ± 25% in 85 d. We observe microorganism colonization on the printed film’s surface. The analysis of the microbial community on the compost reveals that bacterial species within the Acidimicrobiia class, specifically Actinomarinales order, are potentially responsible for the biodegradation of the printed film. Meanwhile, ecotoxicity tests conducted by germinating Lolium multiflorum and Tagetes erecta suggest that printed films have negligible phytotoxicity.

Abstract Mechanochromic photonic crystals are attractive due to their force-dependent structural colors; however, showing unrecordable color and unsatisfied performances, which significantly limits their development and expansion toward advanced applications. Here, a thermal-responsive mechanochromic photonic crystal with a multicolor recordability-erasability was fabricated by combining non-close-packing mechanochromic photonic crystals and phase-change materials. Multicolor recordability is realized by pressing thermal-responsive mechanochromic photonic crystals to obtain target colors over the phase-change temperature followed by fixing the target colors and deformed configuration at room temperature. The stable recorded color can be erased and reconfigured by simply heating and similar color-recording procedures respectively due to the thermoswitchable on-off mechanochromism of thermal-responsive mechanochromic photonic crystals along with solid-gel phase transition. These thermal-responsive mechanochromic photonic crystals are ideal rewritable papers for ink-freely achieving multicolor patterns with high resolution, difficult for conventional photonic papers. This work offers a perspective for designing color-recordable/erasable and other stimulus-switchable materials with advanced applications.

Abstract Microfluidic paper-based analytical devices often are combined with scanners as detectors. In this work, different scanning options offered by scanners: resolution, scanning mode, exposure to radiation, colour restoration, and saving format were tested. Moreover, different attempts to mathematical data treatment based on intensities of three channels—Red, Green and Blue, were studied. All measurements presented in this article were conducted for a model dye—bromothymol blue and a model analyte—zinc(II) ion (complexed with xylenol orange in a paper matrix). The article summarizes the scanning options and possibilities of mathematical calculations. Nevertheless, it is suggested that the best option is to use the prior prepared calculation file to paste obtained intensities and compare all presented in this article (and the most frequently used) equations to process intensities and decide which one should be used in the particular analysis.

Abstract Anger suppression is important in our daily life, as its failure can sometimes lead to the breaking down of relationships in families. Thus, effective strategies to suppress or neutralise anger have been examined. This study shows that physical disposal of a piece of paper containing one’s written thoughts on the cause of a provocative event neutralises anger, while holding the paper did not. In this study, participants wrote brief opinions about social problems and received a handwritten, insulting comment consisting of low evaluations about their composition from a confederate. Then, the participants wrote the cause and their thoughts about the provocative event. Half of the participants (disposal group) disposed of the paper in the trash can (Experiment 1) or in the shredder (Experiment 2), while the other half (retention group) kept it in a file on the desk. All the participants showed an increased subjective rating of anger after receiving the insulting feedback. However, the subjective anger for the disposal group decreased as low as the baseline period, while that of the retention group was still higher than that in the baseline period in both experiments. We propose this method as a powerful and simple way to eliminate anger.

Abstract There has been a growing effort to replace manual extraction of data from research papers with automated data extraction based on natural language processing, language models, and recently, large language models (LLMs). Although these methods enable efficient extraction of data from large sets of research papers, they require a significant amount of up-front effort, expertise, and coding. In this work, we propose the ChatExtract method that can fully automate very accurate data extraction with minimal initial effort and background, using an advanced conversational LLM. ChatExtract consists of a set of engineered prompts applied to a conversational LLM that both identify sentences with data, extract that data, and assure the data’s correctness through a series of follow-up questions. These follow-up questions largely overcome known issues with LLMs providing factually inaccurate responses. ChatExtract can be applied with any conversational LLMs and yields very high quality data extraction. In tests on materials data, we find precision and recall both close to 90% from the best conversational LLMs, like GPT-4. We demonstrate that the exceptional performance is enabled by the information retention in a conversational model combined with purposeful redundancy and introducing uncertainty through follow-up prompts. These results suggest that approaches similar to ChatExtract, due to their simplicity, transferability, and accuracy are likely to become powerful tools for data extraction in the near future. Finally, databases for critical cooling rates of metallic glasses and yield strengths of high entropy alloys are developed using ChatExtract.

Abstract Traditionally, cellulose nanofiber (CNF) production has primarily relied on virgin cellulose sources. Yet, the shift to using paper mill sludge (PMS) as a source for CNF underscores the significance of reusing and recycling industrial byproducts. PMS contains significant amounts of cellulose that can be extracted as a raw material. The purpose of present study is to provide a sustainable approach to PMS utilization as a paper coating additive in the cellulose nanofibrils (CNFPMS) form via simply scalable wire-wound rod coating method. The effect of CNFPMS additive amounts at two coating layers on microstructure and surface properties of coatings such as porosity, air permeability surface roughness and optical properties such as brightness, gloss and CIE L*a*b* is studied, which they can also provide insight for the eventual print performance. Results indicated that the obtained CNFPMS in paper coating shows 52% decrease in porosity, presenting significant improvement in the coating microstructure. The marginal increase in permeability coefficient and surface roughness, 54% and 10%, respectively, suggests improving color reproduction and preventing color density losses. Optical analysis showed slight decrease in brightness and gloss, as was expected. Notably, the lightness was improved, which also indicates increasing color gamut volume in printing applications. As a result, the current work offers a sustainable approach to manage PMS for use in paper coatings as a high-value-added material.

Abstract Despite progress in the prevention and diagnosis of cancer, current technologies for tumor detection present several limitations including invasiveness, toxicity, inaccuracy, lengthy testing duration and high cost. Therefore, innovative diagnostic techniques that integrate knowledge from biology, oncology, medicinal and analytical chemistry are now quickly emerging in the attempt to address these issues. Following this approach, here we developed a paper-based electrochemical device for detecting cancer-derived Small Extracellular Vesicles (S-EVs) in fluids. S-EVs were obtained from cancer cell lines known to express, at a different level, the αvβ6 integrin receptor, a well-established hallmark of numerous epithelial cancer types. The resulting biosensor turned out to recognize αvβ6-containing S-EVs down to a limit of 0.7*103 S-EVs/mL with a linear range up to 105 S-EVs /mL, and a relative standard deviation of 11%, thus it may represent a novel opportunity for αvβ6 expressing cancers detection.

Abstract Oil-immersed transformers are expensive equipment in the electrical system, and their failure would lead to widespread blackouts and catastrophic economic losses. In this work, an elaborate diagnostic approach is proposed to evaluate twenty-six different transformers in-service to determine their operative status as per the IEC 60599:2022 standard and CIGRE brochure. The approach integrates dissolved gas analysis (DGA), transformer oil integrity analysis, visual inspections, and two Back Propagation Neural Network (BPNN) algorithms to predict the loss of life (LOL) of the transformers through condition monitoring of the cellulose paper. The first BPNN algorithm proposed is based on forecasting the degree of polymerization (DP) using 2-Furaldehyde (2FAL) concentration measured from oil samples using DGA, and the second BPNN algorithm proposed is based on forecasting transformer LOL using the 2FAL and DP data obtained from the first BPNN algorithm. The first algorithm produced a correlation coefficient of 0.970 when the DP was predicted using the 2FAL measured in oil and the second algorithm produced a correlation coefficient of 0.999 when the LOL was predicted using the 2FAL and DP output data obtained from the first algorithm. The results show that the BPNN can be utilized to forecast the DP and LOL of transformers in-service. Lastly, the results are used for hazard analysis and lifespan prediction based on the health index (HI) for each transformer to predict the expected years of service.

Abstract As the social organism, Polistes wasps build a communal nest using woody fibers with saliva for sustaining brood and adult population throughout the season. Limited information exists regarding the identification specific plant materials employed in wasp nest building. Thus, we firstly tested if the DNA metabarcoding approach utilizing rbcL and trnL molecular markers could identify the plant species quantitatively and qualitatively inform the mixed-origin woody samples. A threshold of 0.01 proportion of reads was applied for rbcL and trnL molecular markers, while this threshold for median proportion was 0.0025. In assessing taxa richness, the median proportion demonstrated superior performance, exhibiting higher taxa detection power, however, rbcL marker outperformed in quantitative analysis. Subsequently, we applied DNA metabarcoding to identify the plant materials from the nests of two Polistes species, P. mandarinus and P. rothneyi. The results showed that higher preference of Quercus and Robinia as the major nest building materials regardless of the surrounding plant communities, by two wasp species. Material diversity was higher for P. rothneyi than P. mandarinus, which may explain the abundance of this species possibly with heightened adaptive capacities in their nesting behavior. This study demonstrated that DNA metabarcoding could identify the complex nest-building plant materials of paper wasps and provide insights into their ecological interactions in the natural ecosystem.

Abstract This article presents the results of an experiment designed to study the impact of temperature on the characteristic parameters of creeping discharges. The insulating interfaces consist of a thermally enhanced cellulose surface immersed in mineral oil, palm kernel oil methyl ester (PKOME) and castor oil methyl ester (COME). The study was carried out under a standard negative lightning impulse voltage (1.2/50 μs). The article also presents the complete algorithms for calculating the maximum extension of the discharges, the ionisation rate and the charge produced by them. The results of the study show that temperature favors the propagation of discharges and the ionisation rate. It was observed that liquids with a higher dielectric constant and high electrical conductivity were more exposed to the impact of temperature. The results show ionisation increments of 0.973%/°C, 1.093%/°C and 1.076%/°C in mineral oil (MO), COME and PKOME respectively. The maximum extension of the discharges shows a linear evolution with the applied voltage and temperature but a non-linear increment with the temperature. As for the charge produced, it shows a constant increment with temperature and voltage in each liquid. These values are (5.839%/°C, 1.977%/kV), (6.047%/°C, 2.082%/kV) and (6.177%/°C, 2.113%/kV) respectively in MO, COME and PKOME.

Abstract Energy storage devices (ESD) which are intended to power electronic devices, used in close contact of human skin, are desirable to be safe and non-toxic. In light of this requirement, Zn based energy storage devices seem to provide a viable pathway as they mostly employ aqueous based electrolytes which are safe and non-toxic in their functioning. Additionally, having a flexible ESD will play a crucial role as it will enable the ESD to conform to the varying shapes and sizes of wearable electronics which they energize. In this work, we have developed an inkjet-printed Zinc ion battery (IPZIB) with planar electrode configuration over bond paper substrate. Zn has been used as the negative electrode, MnO2 is used as the positive electrode with Poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the active binder. Conducting tracks of reduced graphene oxide (rGO) are used to construct the current collector on the paper substrate. The fabricated IPZIB delivered a high discharge capacity of 300.14 mAh g−1 at a current density of 200 mA g−1. The energy density of the IPZIB is observed as 330.15 Wh kg−1 at a power density of 220 W kg−1 and retains an energy density of 94.36 Wh kg−1 at a high power density of 1650 W kg−1. Finally, we have demonstrated the capability of the IPZIB to power a LED at various bending and folding conditions which indicates its potential to be used in the next generation flexible and wearable electronic devices.

Abstract The surface modification of filters with large pore sizes for the development of low-cost gravity-driven point-of-use (POU) technologies for water disinfection can be an effective strategy to empower people to access safe water instantly, especially in low- and middle-income countries. In this study, the surface of commercial cellulose filter papers, as cheap and bio-based filters, was modified with polydopamine (PDA), polyethyleneimine (PEI) and ZnO/Ag/GO nanocomposite (ZnO/Ag/GO@PDA/PEI papers) for bacterial removal from water. PDA/PEI incorporation introduced a cationic functional layer, which can entrap negative bacteria and make a stable chemical bond with the nanocomposite. ZnO/Ag/GO exhibited promising synergistic antibacterial activities (30 times stronger than ZnO). As a result, 3 sheets of ZnO/Ag/GO@PDA/PEI papers showed a 99.98% bacterial reduction (E. coli), which met the WHO standards. Moreover, the leached zinc and silver in the filtrate were far below the WHO’s limits (380 and 10 ppb, respectively). The results showed that the modified papers could be reused multiple times. After six times of reuse, the flow rate dropped slightly (below 20%) and the bacterial removal efficiency was more than 99.9%. This study is valuable for developing filters for treating bacterial-contaminated water on-site with no need for energy, which is a demand in many countries.

Abstract Trimethylsilyl cellulose (TMSC) was employed as the coating matrix for the application of zinc oxide nanoparticles (ZnO) onto paper surfaces and the protections of ZnO/TMSC coating against UV-induced damages and fungal spoilage were evaluated. Filter papers were immersed in 2% w/v TMSC solution loaded with ZnO and air-dried. Three ZnO/TMSC suspensions were prepared with 0.1, 0.5, and 1% w/v ZnO NPs. The presences of ZnO/TMSC protective layers were confirmed with ATR-IR spectroscopy. The coated papers exhibited high surface hydrophobicities. After the coated papers were subject to 365-nm UV irradiation at 400 W for 3 h, the contact angles dramatically dropped. The trimethylsilyl (TMS) groups exposed on the surface formed a moisture barrier and were partially removed on UV exposure. ATR-IR revealed that more TMS groups were removed in the protective layer with no ZnO. UV-irradiated papers turned yellow and papers protected with 1% ZnO/TMSC exhibited significantly lower color changes than that of the uncoated one. Compared to the TMSC-coated paper, the addition of ZnO resulted in a significant reduction in tensile strength at maximum. However, after UV irradiation, significant increases in both the strain at break and strength at maximum were only observed in 1% ZnO/TMSC-protected papers. Regarding their anti-fungal properties, the 1% ZnO/TMSC films were effective in growth inhibitions of Aspergillus sp. and Penicillium sp. on the nonirradiated papers. Despite being hydrophilic after UV-irradiation, growths of the molds were severely suppressed on the UV-irradiated paper.

Abstract Pronoun usage’s psychological underpinning and behavioral consequence have fascinated researchers, with much research attention paid to second-person pronouns like “you,” “your,” and “yours.” While these pronouns’ effects are understood in many contexts, their role in bilateral, dynamic conversations (especially those outside of close relationships) remains less explored. This research attempts to bridge this gap by examining 25,679 instances of peer review correspondence with Nature Communications using the difference-in-differences method. Here we show that authors addressing reviewers using second-person pronouns receive fewer questions, shorter responses, and more positive feedback. Further analyses suggest that this shift in the review process occurs because “you” (vs. non-“you”) usage creates a more personal and engaging conversation. Employing the peer review process of scientific papers as a backdrop, this research reveals the behavioral and psychological effects that second-person pronouns have in interactive written communications.

Abstract Osteoclasts are the primary target for osteoporosis drug development. Recent animal studies revealed the crucial roles of osteoblasts in regulating osteoclastogenesis and the longer lifespans of osteoclasts than previously thought with fission and recycling. However, existing culture platforms are limited to replicating these newly identified cellular processes. We report a demineralized bone paper (DBP)-based osteoblast culture and osteoclast assay platform that replicates osteoclast fusion, fission, resorption, and apoptosis with high fidelity and analytical power. An osteoid-inspired DBP supports rapid and structural mineral deposition by osteoblasts. Coculture osteoblasts and bone marrow monocytes under biochemical stimulation recapitulate osteoclast differentiation and function. The DBP-based bone model allows longitudinal quantitative fluorescent monitoring of osteoclast responses to bisphosphonate drug, substantiating significantly reducing their number and lifespan. Finally, we demonstrate the feasibility of humanizing the bone model. The DBP-based osteo assay platforms are expected to advance bone remodeling-targeting drug development with improved prediction of clinical outcomes.

Abstract The valorization of paper mill sludge (PMS) is the main goal of this study. The emissions of PMS continue to increase at global scale, especially from packaging paper and board sectors. The raw sludge was used to prepare an adsorbent to remove toxic pollutants from wastewater, the methylene blue (MB), an organic dye. Firstly, the physico-chemical characterization of PMS was done determining the crystalline phases of PMS fibers, the content of main elements, and the pH zero point charge, which was determined at around pH 7. The adsorption of MB on PMS powder was studied at 18 °C with an agitation of 200 rpm, being the best operating conditions 30 min of contact time, 250 mg L−1 of initial MB concentration and 0.05 g in 25 mL of adsorbent dose. Experimental data of MB adsorption was fitted to Langmuir and Freundlich isotherm equations. The Langmuir model was more accurate for the equilibrium data of MB adsorption at pH 5.1. The PFOM and PSOM were adjusted to experimental adsorption kinetics data, being PSOM, which describes better the MB adsorption by PMS powder. This was confirmed by calculating the maximum adsorption capacity with PSOM, which was 42.7 mg g−1, being nearly similar of the experimental value of 43.5 mg g−1. The analysis of adsorption thermodynamics showed that the MB was adsorbed exothermically with a ΔH0 = − 20.78 kJ mol−1, and spontaneously with ΔG0 from − 0.99 to − 6.38 kJ mol−1 in the range of temperature from 291 to 363 K, respectively. These results confirm that the sludge from paper industry can be used as biosorbent with remarkable adsorption capacity and low cost for the treatment of wastewater. PMS can be applied in the future for the depollution of the effluents from the textile industry, which are highly charged with dyes.

Abstract Laserjet printing is a kind of facile and digital do-it-yourself strategies, which is of importance to fabricate inexpensive paper-based microfluidic devices. However, the printed hydrophobic barrier is not hydrophobic enough due to the weak hydrophobicity and requires subsequent heating, which can lead to the pyrolysis of cellulose in the paper and influence the detection results. Here, for the first time, we report a kind of functional toner including toner and polydopamine (PDA) nanocapsules which contains oleic acid modified ferric tetroxide (OA-Fe3O4) and octadecylamine (ODA), which is suitable for printing with desired shapes and sizes to lead to formation of superhydrophobic barriers. Moreover, patterns printed with functional toner have good stability, including resistance to moisture, ultraviolet (UV) and bending. Finally, a proof-of-concept of metal and nitrite ions testing is demonstrated using colorimetric analysis, and the results show that the printed devices successfully perform instant detection of ions. The developed functional toner offers easy fabrication, cost-effectiveness and mass production of paper-based devices. In general, this strategy provides a new idea and technical support for the rapid prototyping of microfluidic paper-based analytical devices (μPADs) using laserjet printing.

Abstract Uropathogenic Escherichia coli (UPEC) causes up to 90% of urinary tract infections (UTI) which is more prevalent among females than males. In urine, patients with symptomatic UTI usually have a high concentration of bacterial infection, ≥ 105 colony-forming units (CFU) per mL, in which the culture method is regularly the gold standard diagnosis. In this study, a simple and inexpensive distance-based paper device (dPAD) combined with the fluorescent closed tube LAMP assay was validated for simultaneously screening and semi-quantifying the infection level of E. coli in 440 urine samples of patients with UTI. The dPAD could measure the LAMP amplicons and semi-quantify the levels of E. coli infection in heavy (≥ 104 CFU/mL), light (≤ 103 CFU/mL) and no infection. The sensitivity and specificity had reliable performances, achieving as high as 100 and 92.7%, respectively. The one step LAMP assay could be performed within 3 h, which was 7.5 times faster than the culture method. To empower early UTI diagnosis and fast treatment, this inexpensive dPAD tool combined with the fluorescent closed tube LAMP assay is simple, reliably fast and practically portable for point-of-care settings, particularly in resource-limited areas, which can be set up in all levels of healthcare facilities.

Abstract Fluorescence analysis is a fast and sensitive method, and has great potential application in trace detection of environmental toxins. However, many important environmental toxins are non-fluorescent substances, and it is still a challenge to construct a fluorescence detection method for non-fluorescent substances. Here, by means of charge transfer effect and smart molecular imprinting technology, we report a sensitive indirect fluorescent sensing mechanism (IFSM) and microcystin (MC-RR) is selected as a model target. A molecular imprinted thin film is immobilized on the surface of zinc ferrite nanoparticles (ZnFe2O4 NPs) by using arginine, a dummy fragment of MC-RR. By implementation of IFSM on the paper-based microfluidic chip, a versatile platform for the quantitative assay of MC-RR is developed at trace level (the limit of detection of 0.43 μg/L and time of 20 min) in real water samples without any pretreatment. Importantly, the proposed IFSM can be easily modified and extended for the wide variety of species which lack direct interaction with the fluorescent substrate. This work offers the potential possibility to meet the requirements for the on-site analysis and may explore potential applications of molecularly imprinted fluorescent sensors.

Abstract In this paper, three kinds of micro-nano bamboo powder (MBP) and alkyl ketene dimer (AKD) were added to the polyvinyl alcohol/cellulose nanofiber (PVA/CNF) coating to prepare PVA/CNF/MBP coated paper and PVA/CNF/M-MBP/AKD coated paper. The results showed that MBP improved the oleophobicity of PVA/CNF coating, and the grease resistance grade of PVA/CNF/B-MBP and PVA/CNF/M-MBP coated papers reached the highest level, with a kit number of 12. Among the PVA/CNF/MBP coated papers, the PVA/CNF/M-MBP coated paper has the best hydrophobic properties, with the water contact angle and Cobb value of 74° and 21.3 g/m2, respectively. In addition, when the AKD dosage was 0.2% in the PVA/CNF/M-MBP/AKD coating, the kit number of the coated paper was 11, the Cobb value was 15.2 g/m2, the water contact angle was 103°, and the tensile strength was found to increase slightly. Therefore, compared with PVA/CNF coated paper, PVA/CNF/M-MBP/AKD coated paper has good strength and excellent hydrophobic and oleophobic properties.

Abstract Paper coating plays an important role in the paper properties, printability and application. The nanocoating is a multifunction layer that provides the paper with unique features. In this work, nanocoating formulas were prepared using a green method and component. The nanocoating formulas were based on biopolymers nanostarch NSt and nanochitosan NCh (NCS) decorated with Egyptian kaolinite Ka doped with zinc nanoparticles NCS@xka/ZnONPs (x represents different ratios) support for multifunctional uses. The nanocoating formulas were characterized using a physiochemical analysis as well as a topographical study. FTIR, XRD, SEM and TEM techniques were used. Additionally, the antimicrobial activity of the tested samples was assessed against six microorganisms including Gram-negative and Gram-positive bacteria. The prepared nanocoating formulas affirmed excellent antimicrobial activity as a broad-spectrum antimicrobial active agent with excellent activity against all representative microbial communities. The nanocoating with the highest ratio of Ka/ZnONPs (NCS@40 ka/ZnONPs) showed excellent antimicrobial activity with an inhibition percentage of more than 70% versus all microorganisms presented. The paper was coated with the prepared suspensions and characterized concerning optical, mechanical and physical properties. When Ka/ZnONPs were loaded into NCS in a variety of ratios, the characteristics of coated paper were enhanced compared to blank paper. The sample NCS@40 ka/ZnONPs increased tensile strength by 11%, reduced light scattering by 12%, and improved brightness and whiteness by 1%. Paper coated with NCh suspension had 35.32% less roughness and 188.6% less porosity. When coated with the sample NCS@10 ka/ZnONPs, the coated paper's porosity was reduced by 94% and its roughness was reduced by 10.85%. The greatest reduction in water absorptivity was attained by coating with the same sample, with a reduction percentage of 132%.

Abstract This paper introduces CORE, a widely used scholarly service, which provides access to the world’s largest collection of open access research publications, acquired from a global network of repositories and journals. CORE was created with the goal of enabling text and data mining of scientific literature and thus supporting scientific discovery, but it is now used in a wide range of use cases within higher education, industry, not-for-profit organisations, as well as by the general public. Through the provided services, CORE powers innovative use cases, such as plagiarism detection, in market-leading third-party organisations. CORE has played a pivotal role in the global move towards universal open access by making scientific knowledge more easily and freely discoverable. In this paper, we describe CORE’s continuously growing dataset and the motivation behind its creation, present the challenges associated with systematically gathering research papers from thousands of data providers worldwide at scale, and introduce the novel solutions that were developed to overcome these challenges. The paper then provides an in-depth discussion of the services and tools built on top of the aggregated data and finally examines several use cases that have leveraged the CORE dataset and services.

Abstract In this work heat transfer papers were loaded with a new core–shell pigment based on precipitating thin shell of titanium dioxide on a core of rice husk silica ash TiO2/RHSA to be applied in dye sublimation printing of textile fabrics. Besides, 0.1% (w/w) cationic polyacrylamide (CPAM) and 1% (w/w) bentonite (Bt) were also added sequentially to improve drainage and filler retention of the paper hand-sheets made from bleached kraft bagasse pulps. The effect of the new core–shell pigment on the mechanical and barrier properties, thermal stability and surface morphology of modified paper sheets were investigated. In addition, the study of transfer printability and ease of dye release from paper to fabric in this heat transfer printing of polyester fabrics using silk-screen printing under different transfer parameters were studied. Also, fastness measurements including washing, light and perspiration of printing polyester fabric were also estimated.

Abstract Paper and packaging materials a lignocellulose-based natural biodegradable polymer that spontaneously releases acetic acid, aldehydes, alcohol, and ester-based volatile organic compounds (VOCs) upon ageing and these VOCs start degrading the paper products and decline their mechanical strength properties. The reactivity of the paper of unbleached wheat straw pulp towards acetic acid and hexanal, which has been proven to have more degrading effects on paper than other VOCs, was considered in this work. The papers were exposed to these volatile compounds for 90 days in an air-tight vessel under ambient environmental conditions. The results showed that hexanal was more destructive than acetic acid with regards to cellulose degradation and depletion in the mechanical strength properties. The paper properties like, tensile, tear and burst index, viscosity, pH and carbonyl group content was measured. The growth of the carbonyl group, evidence of the ageing effects in the paper, detected more in the paper exposed to acetic acid. However, the strength of paper properties declined more with hexanal. FE-SEM analysis of the sample showed the development of pores and damage of cellulose fibre upon ageing. Similarly, the damaging effects of VOCs on cellulose, hemicelluloses and lignin were confirmed by significantly reduced peak detection through FT-IR \analysis. The high crystallinity index of the paper products due to exposure to VOCs was detected by XRD analysis, which confirmed the degradation of the low molecular weight cellulose molecule. Thus, the results are strongly recommended that VOCs that generates due to natural or artificial ageing could be the leading cause of paper degradation.

Abstract Polymers are often combined with magnetostrictive materials to enhance their toughness. This study reports a cellulose nanofibril (CNF)-based composite paper containing dispersed CoFe2O4 particles (CNF–CoFe2O4). Besides imparting magnetization and magnetostriction, the incorporation of CoFe2O4 particles decreased the ultimate tensile strength and increased the fracture elongation of the CNF–CoFe2O4 composite paper. CNF was responsible for the tensile properties of CNF–CoFe2O4 composite paper. Consequently, the magnetic and magnetostrictive properties and tensile properties of CNF–CoFe2O4 composite paper can be controlled by changing the mixture ratio of CNF and CoFe2O4 particles.

Abstract We aimed to investigate differences in patients’ anxiety and satisfaction between patients undergoing paper-based patient decision aid (PDA) for shared decision-making (SDM) and those receiving computer-based PDA. We retrospectively collected questionnaires before and after SDM. Basic demographic data as well as anxiety, satisfaction, knowledge acquisition, and participation in SDM were recorded. We divided our population into subgroups according to use of paper-based or computer-based PDA. In addition, Pearson correlation analysis was applied to assess the relationships among variables. In total, 304 patients who visited our Division of Nephrology were included in the final analysis. Overall, over half of the patients felt anxiety (n = 217, 71.4%). Near half of the patients felt a reduction in anxiety after SDM (n = 143, 47.0%) and 281 patients (92.4%) were satisfied with the whole process of SDM. When we divided all the patients based on use of paper-based or computer-based PDA, the reduction of anxiety level was greater in the patients who underwent paper-based PDA when compared with that of those who underwent computer-based PDA. However, there was no significant difference in satisfaction between the two groups. Paper-based PDA was as effective as computer-based PDA. Further studies comparing different types of PDA are warranted to fill the knowledge gaps in the literature.

Abstract Although often regarded a childhood toy, the design of paper airplanes is subtly complex. The design space and mapping from geometry to distance flown is highly nonlinear and probabilistic where a single airplane design exhibits a multitude of trajectory forms and flight distances. This makes optimization and understanding of their behavior challenging for humans. By understanding the behavior of paper airplanes and predicting flight behavior, there is a potential to improve the design of aerial vehicles that operate at low Reynolds numbers. By developing a robotic system that can fabricate, test, analyze, and model the flight behavior in an unsupervised fashion, a wide design space can be reliably characterized. We find there are discrete behavioral groups that result in different trajectories: nose dive, glide, and recovery glide. Informed by this characterization we propose a method of using Gaussian mixture models to extract the clusters of the design space that map to these different behaviors. This allows us to solve both the forward and reverse design problem for paper airplanes, and also to perform efficient optimization of the geometry for a given target flight distance.

Abstract Paper-based electronics have attracted much attention due to their softness, degradability, and low cost. However, paper-based sensors are difficult to apply to high-humidity environments or even underwater. Here, we report a fully paper-integrated piezoresistive sensing system that exhibits flexibility, waterproofing, air permeability, and biocompatibility. This system consists of hydrophobic paper as the substrate and encapsulation layer, conductive paper with a double ‘zig-zag’ and dotted surface structure as the sensing layer, and silver paste films as the interconnects. The structural design of the sensing layer helps to increase the contact area in adjacent layers under pressure and further improves the pressure sensitivity. The piezoresistive system can be worn on human skin in the ambient environment, wet environment, and water for real-time monitoring of physiological signals with air permeability and waterproofing due to its hydrophobic fiber structure. Such a device provides a reliable, economical, and eco-friendly solution to wearable technologies.

Abstract This study performs a chemical investigation of blood plasma samples from patients with and without fibromyalgia, combined with some of the symptoms and their levels of intensity used in the diagnosis of this disease. The symptoms evaluated were: visual analogue pain scale (VAS); fibromyalgia impact questionnaire (FIQ); Hamilton anxiety rating scale (HAM); Tampa Scale for Kinesiophobia (TAMPA); quality of life Questionnaire—physical and mental health (QL); and Pain Catastrophizing Scale (CAT). Plasma samples were analyzed by paper spray ionization mass spectrometry (PSI-MS). Spectral data were organized into datasets and related to each of the symptoms measured. The datasets were submitted to multivariate classification using supervised models such as principal component analysis with linear discriminant analysis (PCA-LDA), successive projections algorithm with linear discriminant analysis (SPA-LDA), genetic algorithm with linear discriminant analysis (GA-LDA) and their versions with quadratic discriminant analysis (PCA/SPA/GA-QDA) and support vector machines (PCA/SPA/GA-SVM). These algorithm combinations were performed aiming the best class separation. Good discrimination between the controls and fibromyalgia samples were observed using PCA-LDA, where the spectral data associated with the CAT symptom achieved 100% classification sensitivity, and associated with the VAS symptom achieved 100% classification specificity, with both symptoms at the moderate level of intensity. The spectral variable at 579 m/z was found to be substantially significant for classification according to the PCA loadings. According to the human metabolites database, this variable can be associated with a LysoPC compound, which comprises a class of metabolites already evidenced in other studies for fibromyalgia diagnosis. This study proposed an investigation of spectral data combined with clinical data to compare the classification ability of different datasets. The good classification results obtained confirm this technique is as a good analytical tool for the detection of fibromyalgia, and provides theoretical support for other studies about fibromyalgia diagnosis.

Abstract In medical institutions, radiation shielding is an effective strategy to protect medical personnel and patients from exposure. Reducing the weight of the shield worn by medical personnel in the radiation generating area plays a key role in improving their productivity and mobility. In this study, a new lightweight radiation shield was developed by electrospinning a polymer-tungsten composite material to produce nanofibers with a multi-layered thin-film structure similar to that of a morpho butterfly wing. The fabricated shield was in the form of 0.1 mm thick flexible shielding paper. The multi-layer structure of the thin shielding paper was obtained through nanofiber pattern formation via electrospinning a dispersion of tungsten particles. At 0.1 mm thickness, the paper’s shielding rate was 64.88% at 60 keV. Furthermore, at 0.3 mm thick and arranged in a laminated structure, the shielding rate was 90.10% and the lead equivalent was 0.296 mmPb. When used as an apron material, the weight can be reduced by 45% compared to existing lead products. In addition, the material is highly processable and can be used to manufacture various flexible products, such as hats, gloves, underwear, and scarves used in medical institutions.

Abstract Numerous scientific, health care, and industrial applications are showing increasing interest in developing optical pH sensors with low-cost, high precision that cover a wide pH range. Although serious efforts, the development of high accuracy and cost-effectiveness, remains challenging. In this perspective, we present the implementation of the machine learning technique on the common pH paper for precise pH-value estimation. Further, we develop a simple, flexible, and free precise mobile application based on a machine learning algorithm to predict the accurate pH value of a solution using an available commercial pH paper. The common light conditions were studied under different light intensities of 350, 200, and 20 Lux. The models were trained using 2689 experimental values without a special instrument control. The pH range of 1: 14 is covered by an interval of ~ 0.1 pH value. The results show a significant relationship between pH values and both the red color and green color, in contrast to the poor correlation by the blue color. The K Neighbors Regressor model improves linearity and shows a significant coefficient of determination of 0.995 combined with the lowest errors. The free, publicly accessible online and mobile application was developed and enables the highly precise estimation of the pH value as a function of the RGB color code of typical pH paper. Our findings could replace higher expensive pH instruments using handheld pH detection, and an intelligent smartphone system for everyone, even the chef in the kitchen, without the need for additional costly and time-consuming experimental work.

Abstract The study's goal was to develop a spore-based paper strip biosensor for detecting ß-lactam antibiotics in milk using the enzyme induction principle. A new spore-based paper strip biosensor has been developed after important operating parameters such as spore volume, substrate volume, exposure time and temperature, and incubation time and temperature were optimised. The limit of detection for various ß-lactam antibiotics, including amoxicillin, penicillin, ampicillin, carbenicillin, cloxacillin, nafcillin, oxacillin, cephalothin, cefalexin, cefoxitin, cefazolin, and cefuroxime, was determined in milk with detection sensitivity of 1 ppb, 2 ppb, 2 ppb, 10 ppb, 10 ppb, 10 ppb, 20 ppb, 10 ppb 1000 ppb, 10 ppb 300 ppb and 100 ppb, respectively. It was also tested with other contaminants such non-ß-lactam antibiotics, pesticides, aflatoxin, heavy metals, and other chemical contaminants, and no interference was found, indicating that the created biosensor had a low rate of false positive and negative results. In comparison to the AOAC-approved CHARM-ROSA ß-lactam strip test, which identified 7 raw milk and zero pasteurised milk samples positive for ß-lactam antibiotics, the sensor was further analysed and verified using 200 raw milk and 105 pasteurised milk samples. This indicates a perfect match between our biosensor and the AOAC-approved CHARM-ROSA ß-lactam strip test. The developed spore-based paper strip biosensors are expected to be useful in the rapid and cost-effective detection of ß-lactam antibiotic residues in milk samples at the dairy farm, reception dock, and production units, respectively.

Abstract There is increasing focus on applying deep learning methods to electrocardiograms (ECGs), with recent studies showing that neural networks (NNs) can predict future heart failure or atrial fibrillation from the ECG alone. However, large numbers of ECGs are needed to train NNs, and many ECGs are currently only in paper format, which are not suitable for NN training. We developed a fully-automated online ECG digitisation tool to convert scanned paper ECGs into digital signals. Using automated horizontal and vertical anchor point detection, the algorithm automatically segments the ECG image into separate images for the 12 leads and a dynamical morphological algorithm is then applied to extract the signal of interest. We then validated the performance of the algorithm on 515 digital ECGs, of which 45 were printed, scanned and redigitised. The automated digitisation tool achieved 99.0% correlation between the digitised signals and the ground truth ECG (n = 515 standard 3-by-4 ECGs) after excluding ECGs with overlap of lead signals. Without exclusion, the performance of average correlation was from 90 to 97% across the leads on all 3-by-4 ECGs. There was a 97% correlation for 12-by-1 and 3-by-1 ECG formats after excluding ECGs with overlap of lead signals. Without exclusion, the average correlation of some leads in 12-by-1 ECGs was 60–70% and the average correlation of 3-by-1 ECGs achieved 80–90%. ECGs that were printed, scanned, and redigitised, our tool achieved 96% correlation with the original signals. We have developed and validated a fully-automated, user-friendly, online ECG digitisation tool. Unlike other available tools, this does not require any manual segmentation of ECG signals. Our tool can facilitate the rapid and automated digitisation of large repositories of paper ECGs to allow them to be used for deep learning projects.

Abstract In the present work, the composite cross-linked were used to consolidate the dyed paper manuscripts. Nanocomposites of mesoporous silica nanoparticle (MPSNP)/polyvinyl alcohol (PVA) and cellulose nanofiber (CNF)/PVA, which have never been used before, have been evaluated for the consolidation process of the dyed paper manuscripts with madder extract. Three concentrations 1%, 3%, and 5% have been prepared. Analysis and investigation methods like scanning electron microscope (SEM), transmission electron microscope (TEM), dynamic light scattering analysis (DLS), X-Ray diffraction Analysis (XRD), atomic force microscope (AFM), Fourier transform infrared spectroscopy (FTIR) and total color difference (ΔE) by spectrophotometer have been used in order to characterize the prepared nano-sized composites and evaluate the treated dyed paper samples before and after the aging process. The results of surface morphology by SEM revealed the effectiveness of MPSNP/PVA core–shell nanocomposite at 5% in the consolidation process, where the improvement of properties of the aged dyed paper samples. The fibers of the treated paper became strong and appeared clearly. The result of ΔE measurements showed that the treated sample with MPSNP/PVA nanocomposite at 5% gave the lowest ΔE (5.22), while, the treated sample with CNF/PVA nanocomposite at 5% gave the highest ΔE value (11.66). Mechanical measurements (tensile strength and elongation) revealed the efficiency of MPSNP/PVA nanocomposite at 5% in the treatment of the aged dyed paper samples. The treated sample with the mentioned material gave tensile strength and elongation values of 84.8 N/nm2 and 1.736%, respectively. In contrast, the treated sample with CNF/PVA nanocomposite at 1% gave the lowest tensile strength and elongation values 38.2 N/nm2, and 1.166%, respectively. FTIR analysis revealed an increase was noticed in the CH2 stretching band (refers to the crystallinity of cellulose), where the intensity of the treated sample with MPSNP/PVA nanocomposite was at a 5% increase compared to the control sample. The FTIR results supported the results of mechanical measurements. The intensity of the CH2 stretching band, which refers to the crystallinity index of cellulose, was increased with the use of MPSNP/PVA nanocomposite at 3% and 5%, which explains the improvement in mechanical properties. This may be due to the nano-mineral particles, which improve the mechanical properties. Additionally, they reduce the effect of accelerated thermal aging on the cellulosic fibers and give them stability. The detailed analysis of analytical methods used for evaluation revealed the novelty of MPSNP/PVA nanocomposite, especially at 5%. It has a potential role in strengthening and improving different properties of the dyed paper manuscripts with madder extract.

Abstract Hydrogen peroxide (H2O2) has attracted considerable attention for use as a disinfectant ingredient for various applications over the decades. The use of H2O2 within the safety regulations can avoid its toxicity to human health and the environment. In this study, a paper-based sensor containing green-synthesized silver nanoparticles (P-AgNPs) was developed for use in a smartphone in the determination of the H2O2 concentration. In the synthesis process, an extract of spent coffee grounds was used as a bioreducing agent. The effects of reaction time and silver nitrate (AgNO3) concentration on the green synthesis of silver nanoparticles (AgNPs) were investigated. The optimum conditions for the preparation of P-AgNPs were determined to be 100 mM AgNO3 (P-AgNPs-100) and 15 h synthesis time. The P-AgNPs-100 sensor exhibited high sensitivity with a detection limit of 1.26 mM H2O2, which might be suitable for the detection of H2O2-based household and beverage sanitizers. The H2O2 detection capability of P-AgNPs-100 was comparable to that of a commercial strip sensor. Furthermore, P-AgNPs-100 had a detection efficiency of more than 95% after long-term storage for 100 days.

Abstract Paper-based analytical devices are promising choices for rapid tests and lab-on-chip detection techniques. Carbon quantum dots (CQDs), on the other hand, are biocompatible nanomaterials, which are industrially promising, due to their fast and cost-effective gram-scale synthesis techniques, as well as their significantly high and stable photoluminescence (PL) properties, which are durable and reliable over a year. However, there have been limitations in the entrapment of CQDs on cellulose papers in a way that their PL is not influenced by the flowing of the CQDs with the stream of analyte fluid, making the sensors less accurate at very low concentrations of liquid analytes. Therefore, in this investigation, a polyvinyl alcohol/alkaline-based method was systematically generated and developed to entrap CQDs inside a 3D crystalline matrix on paper, in a way that they can be used directly as probes for a simple drop-and-detect method. As a proof of concept, N/P-doped CQD on cellulose paper was used to make fluorescent paper-based analytical devices for identifying traces of Hg2+ of around 100 ppb. The designed sensor was tested over several months, to study its durability and functionality over long periods, for potential industrial applications.

Abstract The effect of cellulose nanofibers (CNFs)/polyvinyl alcohol (PVA) coating on the hydrophobic, oleophobic, and strength properties of paper were investigated. The results showed that the size of bamboo fibers (BFs) decreased significantly and the crystallinity increased significantly after biological enzyme treatment. The average length of CNFs obtained by high pressure homogenization was 2.4 µm, the diameter was 28.7 nm, and the crystallinity was 63.63%. When the coating weight of PVA/CNF was 2.0 g/m2 and the CNF dosage was increased from 0.0% to 3.0%, the paper grease resistance grade was increased from 7 to 9, the Cobb value was decreased from 22.68 ± 0.29 g/m2 to 18.37 ± 0.63 g/m2, the contact angle was increased from 67.82° to 93.56°, and the longitudinal and transverse tensile index were increased from 67.72 ± 0.21 N m/g and 37.63 ± 0.25 N m/g to 68.61 ± 0.55 N m/g and 40.71 ± 0.78 N m/g, respectively. When the CNF dosage was 3.0% and the coating weight of PVA/CNF was 4.0 g/m2, the grease resistance grade of the paper was 12, the Cobb value was 21.80 ± 0.39 g/m2, and the longitudinal and transverse tensile indices were 72.11 ± 0.43 N m/g and 42.58 ± 0.48 N m/g, respectively. In summary, the increase of CNFs can effectively improve the lipophobicity, hydrophobicity and tensile strength of the PVA coated paper.