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This manuscript reports on a simple paper-based bienzymatic colorimetric assay for sarcosine as an important urinary biomarker of prostate cancer. All required assay reagents are pre-deposited on hydrophilic filter paper spots surrounded by a hydrophobic barrier. Sarcosine in the sample solution is selectively oxidized in the presence of sarcosine oxidase (SOx), resulting in the formation of hydrogen peroxide, which is subsequently detected through the horseradish peroxidase (HRP)–catalyzed conversion of the colorless indicator 3,3',5,5'-tetramethylbenzidine (TMB) into its blue-colored oxidation product. By the modification of the paper with positively charged poly(allylamine hydrochloride) (PAH), a linear response to sarcosine between 0 and 10 μM and a significant lowering of the limit of detection (LOD) (0.6 μM) compared to the unmodified paper substrate (12.6 μM) has been achieved. The improvement of the LOD was attributed to the fact that the presence of the polymer limits the enzyme-driven colorimetric reaction to the surface of the paper substrate, resulting in stronger color development. In experiments in artificial urine matrix, the bicarbonate anion was identified as an inhibitor of the colorimetric reaction. This inhibition was successfully eliminated through on-device sample pH adjustments with pH-buffer components pre-deposited onto assay devices. The LOD for sarcosine achieved in artificial urine matrix (2.5 μM) is below the 5 μM threshold value for this urinary biomarker required for diagnostic purposes. Finally, good selectivity over all 20 natural amino acids and satisfactory long-term storage stability of reagent-modified paper substrates at − 20 °C for a period of 50 days were confirmed. [ABSTRACT FROM AUTHOR]

Paper-based material is receiving more and more attention as an alternative of plastics in flexible electronics. However, conventional paper made of cellulose fibers is opaque owing to its micron-sized void space among fibers. Herein, cellulose fiber paper was changed into transparent paper by sequentially coating cationic cellulose nanofibers (CNFs) and polyvinylpyrrolidone (PVP). The morphology, transparency, thermal and mechanical properties were analyzed. The results show that the coating of CNFs reduces the micron-sized void space in the cellulose fiber paper, favoring the further improvement on the transparency of paper by coating PVP. By optimizing the coating amount of CNFs and PVP, a transparent paper with a transmittance of 88.5 % at 550 nm is obtained. The as-prepared transparent paper also shows improved thermal stability, slightly increased tensile strength and significantly enhanced deformation resistance. It was a potential candidate of flexible electronic substrates. [ABSTRACT FROM AUTHOR]

Recently, mulberry paper has attracted much attention as a substrate for paper-based energy storage and conversion systems due to the excellent mechanical and chemical stability arising from its holocellulose-based structure and low lignin content, which overcome the limitations of typical cellulose-based paper. The formation of an electrically conducting layer on the mulberry paper is a key step in fabricating the mulberry paper-based energy storage and conversion system. Various methods such as coating, printing, composite formation, and carbonization have been used to provide mulberry paper with electrical conductivity. The properties of mulberry paper electrodes largely depend on the choice of fabrication method, with each method having distinct advantages and disadvantages. Despite of the importance of the processing technology for forming the conducting layer, no comprehensive review on the topic exists to-date, especially with respect to mulberry paper. Hence, the present review introduces the research trends on mulberry paper-based energy storage and conversion devices, and focuses on the technology for fabricating the conducting layer. The advantages and disadvantages of the various fabrication methods are discussed in order to provide a future research direction for mulberry paper-based electrode fabrication, and for its application to the energy storage and conversion system. [ABSTRACT FROM AUTHOR]

Paper-based analytical devices (PADs) are powerful platforms for point-of-need testing since they are inexpensive devices fabricated in different shapes and miniaturized sizes, ensuring better portability. Additionally, the readout and detection systems can be accomplished with portable devices, allying with the features of both systems. These devices have been introduced as promising analytical platforms to meet critical demands involving rapid, reliable, and simple testing. They have been applied to monitor species related to environmental, health, and food issues. Herein, an outline of chronological events involving PADs is first reported. This work also introduces insights into fundamental parameters to engineer new analytical platforms, including the paper type and device operation. The discussions involve the main analytical techniques used as detection systems, such as colorimetry, fluorescence, and electrochemistry. It also showed recent advances involving PADs, especially combining optical and electrochemical detection into a single device. Dual/combined detection systems can overcome individual barriers of the analytical techniques, making possible simultaneous determinations, or enhancing the devices' sensitivity and/or selectivity. In addition, this review reports on distance-based detection, which is also considered a trend in analytical chemistry. Distance-based detection offers instrument-free analyses and avoids user interpretation errors, which are outstanding features for analyses at the point of need, especially for resource-limited regions. Finally, this review provides a critical overview of the practical specifications of the recent analytical platforms involving PADs, demonstrating their challenges. Therefore, this work can be a highly useful reference for new research and innovation. [ABSTRACT FROM AUTHOR]

The surface plasmon resonance property of silver nanoparticles (AgNPs) makes them a top-notch material for developing sensors, especially in surface-enhanced Raman scattering (SERS). The multi-shape silver nanoparticles decorated on cellulose fiber of paper provide flexible paper-based SERS substrates with different sensitivity. The isotropic and anisotropic morphology of AgNPs on filter paper has been controlled by weak and strong reducing agents: sodium borohydride (NaBH4), ascorbic acid (L-AA), glucose, formaldehyde (HCHO). The capping agent's chitosan and the reaction conditions like the ratio of precursors and stirring speed also influence the shape, size, stability, and dispersity of AgNPs on filter paper. Multi-shape AgNPs on paper are obtained as spherical shapes (about 50–100 nm), rods (size 100–500 nm in length, 50-nm wide), or thin wings. Depending on the reduction condition, these AgNPs can be single-dispersed or stuck together to form corals on paper. The fabricated paper-based SERS substrates were investigated the optical characterization and used to detect melamine in an aqueous solution with detection limits as low as 10−8 M with the EF = 2.3 × 109. [ABSTRACT FROM AUTHOR]

Chitosan is a biopolymer that has shown promising results for surface treatment of paper to enhance barrier and mechanical properties. Commercially, chitosan is available with a wide range of degree of deacetylation (DD). Herein, effect of DD on performance of chitosan in surface application of paper is investigated. Surface application of chitosan of different DD (77%, 84% and 94%) was done at a dose of 1.0 ± 0.2 g/m2 on kraft paper and comparison in terms of strength, structural, surface and barrier properties of paper was performed. Different DD of chitosan was confirmed by FTIR analysis. Results showed that breaking length of paper maximally increased by 15.2%/26.6% in machine direction (MD)/cross direction (CD), respectively after surface application of 94% DD chitosan followed by 77% DD and 84% DD. The maximum increase in burst index, stretch in MD and TEA in both directions of paper was found after surface application of 94% DD chitosan. Results attained by 77% DD and 84% DD chitosan for improvement in burst index, stretch and tensile energy absorption of paper were also encouraging. Maximum increase in stiffness was observed in CD with application of 84% DD chitosan. Double fold of paper also increased the maximum after surface application of 84% DD chitosan. The best results of contact angle, surface energy, Cobb60 and water vapor transmission rate were attained after surface application with 94% DD chitosan whereas the results attained by 77% DD and 84% DD chitosan for contact angle, surface energy, Cobb60 were also encouraging. [ABSTRACT FROM AUTHOR]

In order to solve the hygroscopicity of ammonium polyphosphate (APP) and improve its flame retardancy, hydrophobic and flame retardant groups were introduced on the surface of APP by means of surface coating. It was blended with styrene acrylic emulsion (AAS) as the reinforcing resin and applied to the automobile engine air filter paper. The structure of the modified particles was confirmed by FT-IR TGA showed that the initial decomposition temperature of the modified particles decreased by 15 ℃, the decomposition rate decreased by about 5%, and the carbon residue rate at 800 ℃ increased from 21.73 to 44.92%; The DSC displayed that the blend resin had fine compatibility. Particle size analysis, scanning electron microscopy and transmission electron microscopy demonstrated that the large size modified APP particles were diffused into styrene acrylate emulsion particles and reconstituted to form a more compact and smaller particle size. The particles had a core shell structure with a shell thickness of 17 nm. These phenomena revealed the evolution of latex particles after blending. The air filter paper reinforced by blend resin has better mechanical properties and good water resistance. After absorbing water, the burst retention rate of air filter paper is more than 50%, and the stiffness retention rate is more than 20%. The combustion test and analysis by cone calorimeter analysis that the blend resin give the air filter paper excellent flame retardant performance. [ABSTRACT FROM AUTHOR]

Paper folding-and-punching tests are used to measure spatial abilities in humans. This paper presents a qualitative model for paper folding (QPF) and a computer game (Paper Folding Game) developed to apply and show the reasoning capabilities of the QPF model. This interactive game presents paper-folding activities intended to help users train and understand how to fold a paper to get a specific shape. Then, it presents paper-folding-and-punching tests to the players. The Paper Folding Game can automatically generate paper-folding-and-punching questions with varying degrees of difficulty depending on the number of folds and holes made, thus producing additional levels for training. The reasoning mechanisms in the QPF model are used by the Paper Folding Game to infer the right answer to each paper-folding-and-punching question. This reasoning capability allows the game to provide feedback to the players when they are wrong and also to create other plausible answers automatically, so that random question-answers are shown to the players in the master-mode. The Paper Folding Game has been implemented using Unity engine and it is available to download from GooglePlay and AppleStore for everyone to train their spatial reasoning skills. [ABSTRACT FROM AUTHOR]

The development of paper-based analytical platforms has brought a requirement on easily creating patterned paper sensors. This article describes a facile method of fabricating patterned paper sensors using a combination of wettability-controlled paper and the precipitation assays between analytes and sensing elements. Different from common fabrication processes in which patterned channels are defined by creating hydrophobic barriers, herein the direct deposition of the patterns of sensing elements onto paper is performed by simple writing and stamping. Without hydrophobic treatment, the patterned sensing components can remain in place on the paper substrate whose wettability is tuned via bovine serum albumin (BSA) modification. After exposure to the analytes, the precipitates of sensing reactions are not delocalized, giving a simple and successful patterned signal readout. The results of typical colorimetric assays show that slow capillary flow and insoluble products together on paper provide an extremely easy route for fabricating multifunctional patterned paper sensors. [ABSTRACT FROM AUTHOR]

During the past decades, several academic paper recommendation systems were introduced in literature aiming to assist users in finding relevant papers close to their needs. In particular, those models have used users' past preferences combined with papers' side information to personalize their recommendations. Unfortunately, the majority of those models fail to utilize the implicit relationship between the crucial elements along with the semantic relations of the nodes in a Heterogeneous Information Network (HIN), which can further improve the accuracy of the models. In this paper, we propose a research article recommendation model that aims to tackle those issues by exploiting both textual and graph representations, simultaneously. The model employs SPECTER document embedding to learn context-preserving research article representations. In particular, it learns the features from a HIN, which is a knowledge graph of the node entities and their relationships. Then, an attention module strengthens the semantic feature extraction process and learns enhanced representations. The combined semantic and structural features are then provided as input to a Deep Neural Network (DNN) in order to learn high-level representations of query and candidate papers. We have evaluated our model against state-of-the-art models over two popular datasets. The results indicate a significant improvement in terms of MAP, recall, and MRR. [ABSTRACT FROM AUTHOR]

Waste paper holds great potential as a substrate for the microbial production of bioplastic (Poly-3-hydroxybutyrate (PHB)). This study aimed to produce PHB by utilizing office paper as a substrate using Cupriavidus necator through batch and fed-batch simultaneous saccharification and fermentation (SSF) approach. For the batch experiment, different loadings of shredded office paper (3, 5 and 10%) with two different pretreatments H2O2 (OPH) and H2O2 and Triton X-100 (OPTH) were carried out. For the fed-batch experiment, paper loading started with 3% and two more additions were made at 36 and 84 h. Both experiments were conducted at 30 °C, 200 rpm and pH 7 using 55.5 FPU/g of cellulase and 37.5 CBU/g of β-glucosidase with a fixed amount of nitrogen source. High PHB yield was observed with OPH in all loadings, though the OPHT showed a better hydrolysis. Maximum PHB yield (4.27 g/L) was achieved with 10% OP on the sixth day of fermentation in batch SSF. Whereas, maximum PHB yield (4.19 g/L) was obtained within a shorter time (66 h)with OPH in the fed-batch experiment. The extracted PHB showed well-matched characteristic features to the standard PHB. Finally, this study proves the feasibility of employing the SSF process for PHB production using waste paper as an alternative approach to overcome the shortcoming of the separate hydrolysis and fermentation (SHF) process. [ABSTRACT FROM AUTHOR]

Technological advancements in flexible and wearable electronics have driven a boom in high-performance flexible electrodes. In this study, a simple and low-cost bio-inspired filter paper (FP) template method using the interfacial-aided polyethyleneimine-functionalized filter paper (FP-PEI) was developed to fabricate highly flexible silver-based conductive films. The FP was modified through amination to obtain FP-PEI with the rigid cellulose backbone and the flexible side chain of grafted amino groups, which played a key role as an interfacial layer during the chemical deposition of fractal-structured silver particles (FSSPs). The naturally porous and rough network structures of FP templates provided structural support and network for the deposition of conductive materials. In addition, the high porosity of FP facilitated the effective transfer of electrons, and its nano- or micro-scale rough surface structure promoted the formation of strong adhesion between the cellulose substrate and the conductive layer, which was crucial for the conductive stability of the device. The obtained conductive films (FP-PEI/FSSPs) exhibited a low sheet resistance of 1.47 Ω sq−1, a conductivity of 3401 S m−1, and good mechanical properties with a stress strength of 6.17 MPa. Moreover, FP-PEI/FSSPs exhibited a stable electrical conductivity (the sheet resistance only increased by 0.06 Ω sq–1 through 500 bending cycles), thermal stability (the maximum thermal decomposition rate increased from 349.3 to 357.8 °C), and oxidation resistance (the sheet resistance increased by only 0.04 Ω sq–1 after FP was exposed to the air for 15 days). The results indicate that FP-PEI/FSSP conductive films can be a potential green flexible electronic material. [ABSTRACT FROM AUTHOR]

Currently, water-soluble chitosan (WSC) has been developed through a pressurized hydrolysis process. Compared to acid-soluble chitosan, the WSC is soluble in water, and it is used in many applications such as pharmaceutical, food, and composite industries. The FTIR and thermal properties such as TGA were investigated to determine the effect as a sizing agent material on paper composite. Furthermore, the influence of pulp weight variation of 1, 1.5, and 2 g and WSC concentration of 0.25, 0.5, 0.75, and 1.0% (w/v) on the physical, mechanical, and antimicrobial properties of the paper composites were studied. The density and grammage increased after incorporating due to the increase in the dissolved concentration of WSC. The mechanical properties, such as tensile strength, tensile modulus, and elongation at break, were also improved to the highest value of 2.76 MPa, 170.58 MPa, and 2.67% at 1.0% WSC and 1 g pulp concentration, respectively. The paper composite incorporated WSC also showed antimicrobial activity against Gram-positive (Staphylococcus aureus) bacteria and Gram-negative (Escherichia coli). However, increased concentration of WSC up to 1% caused inhibition zone of Gram-negative (Escherichia coli and Salmonella typhi) and Gram-positive (Staphylococcus aureus and Bacillus subtilis) bacteria. [ABSTRACT FROM AUTHOR]

Paper-based relics as important carriers of human history and civilization have been facing severe damage problems, and their protection is a major project for cultural heritage restoration. So far, safe, high-efficiency, and multifunctional protection materials are still urgent to be developed. Herein, through screening a series of alkaline nano-oxides and cleverly combining the advantages of modified natural polymer (quaternized chitosan) and inorganic nanomaterials (ZnO), we successfully prepared their functional nanocomposites with multiple properties and pioneered their smart application for multifunctional protection of paper relics. By spraying loads, this kind of nanocomposites can effectively and safely inhibit the acid degradation of paper relics and long-term maintain a natural or weak basic state even under harsh accelerated aging conditions. Meanwhile, the coating of nanocomposites does not change the chromatic aberration but partially improves the hydrophobicity. Moreover, the mechanical properties of paper relics are reinforced up to more than one time for all-around tensile strength, folding endurance, and tearing strength. It is worth noting that the usage of nanocomposites can avoid the discoloration or fading of pH-sensitive pigments/dyes and prevent the blue/red inks from ink-spreading. By integrating the anti-microorganism effects of the two components, the nanocomposites have exhibited a broad antimicrobial capacity for both fungi (e.g., Plectosphaerella cucumerina and Aspergillus unguis) and bacteria (e.g., Staphylococcus aureus). The acquired knowledge not only represents an advanced step for designing functionalized inorganic/polymer nanocomposite but also sheds light on the multi-functional integrated protection of paper-based relics. [ABSTRACT FROM AUTHOR]

A paper-based analytical device (PAD) is presented with colorimetric/electrochemical dual readouts for the simultaneous sensing of total chromium (Cr) and hexavalent chromium (Cr(VI)). This device consists of a homemade three-electrode system and a patterned paper chip, integrating multiple functions including electrochemical detection, fluid driving, online oxidation, and colorimetric detection. The fiberglass filter paper with a hydrophilic microchannel was used to achieve self-driving fluidics without external equipment. One end of the microchannel was integrated with a homemade three-electrode system to achieve sample loading and electrochemical detection. The middle region on the microchannel was modified with oxidizing reagents to perform online pretreatment, and the yield of Cr(III) oxidation can reach 97.9%, ensuring reliable colorimetric detection of total Cr at another end of the microchannel modified with chromogenic agents. With this device, the signals of Cr(VI) (the signal peak at 0.29 V vs. Ag/AgCl) and total Cr can be obtained in one single injection. After optimization, the limit of detection (LOD) of Cr(VI) and total Cr were 0.01 mg L−1 and 0.06 mg L−1 and the linear ranges were 0.05–3.0 mg L−1 and 0.2–3.0 mg L−1, respectively. The relative standard deviations (RSD) of the electrochemical testing of Cr(VI) results were in a range 1.3%–8.7% (n = 3), and the RSD values of the colorimetric testing of total Cr were between 0.7–9.2% (n = 3). The device's reliability was demonstrated by performing the practical speciation of Cr in tap water, river water, and electroplating wastewater while the recoveries obtained using the present method were in the range 93.5–106%. Overall, the proposed device provides high application prospect in the on-site rapid Cr speciation. [ABSTRACT FROM AUTHOR]

The pulp and paper industry have historically been one of the world's largest consumers of freshwater resources and producers of wastewater discharges. More than 250 chemicals have been identified in effluents including chlorine-based organic and other toxic compounds. Some of these are resistant to biological degradation such as color-related compounds. The goal of this study was to analyze the real wastewater from the paper mill and to suggest a photocatalytic treatment method in order to reduce the organic pollutants load. The efficiency of the commonly used treatment photocatalytic processes (photo-TiO2 and photo-Fenton reagent) on the treatment of real paper mill effluent was investigated. Additionally, the performance of TiO2 photocatalytic reactions with and without the addition of hydrogen peroxide was also examined. For the experiment, a 500 mL pyrex UV reactor and a 125-W high-pressure mercury lamp, surrounded by pyrex filter blocking wavelengths below 290 nm were used. The approach has been applied for the treatment of effluents produced from a papermaking industry. [ABSTRACT FROM AUTHOR]

The present study aimed to investigate indigenous bacteria possibility in recycled paper and cardboard mill (RPCM) wastewater treatment through the isolation and identification of full-scale RPCM indigenous bacteria. The molecular characterization of the isolated bacteria was performed by 16S rRNA gene sequencing. Klebsiella pneumoniae AT-1 (MZ599583), Citrobacter freundii AT-4 (OK178569), and Bacillus subtilis AT-5 (MZ323975) were dominant strains used for RPCM wastewater bioremediation experiments. Under optimal conditions, the maximum values of chemical oxygen demand (COD) and color biodegradation by C. freundii AT-4 were 79.54% and 43.81% after 10 days of incubation, respectively. In the case of B. subtilis strain AT-5 and K. pneumoniae AT-1, the maximum values of COD and color biodegradation were 70.08%, 45.96%, 71.26%, and 32.06%, respectively. The results from optimal conditions regarding efficiency were higher in comparison with the efficiency obtained from the oxidation ditch treatment unit in full-scale RPCM-WWTP. Therefore, the present study introduces the isolated indigenous bacteria strains as a promising candidate for improving the RPCM-WWTP efficiency using bioremediation. [ABSTRACT FROM AUTHOR]

The clinical importance of blood group (BG) antigens is related to their ability to induce immune antibodies that can cause hemolysis. Yet, ABO and D (Rh) are still considered to be the key antigens for healthy blood transfusion and secondary antigens are the next priority. Serological typing is the most widely used typing method. Rapid and accurate blood grouping plays an important role in some clinical conditions, rather than conventional techniques. Hence, developing a simple and economical model for rapid blood grouping would facilitate these tests. In recent decades, paper-based microfluidics such as μPADs has gained much interest in wide application areas such as point-of-care diagnostic. In this study, we evaluated μPADs that are performed for blood grouping and its recent progress. A comprehensive literature search was performed using databases including PUBMED, SCOPUS, Web of Science and Google Scholar. Keywords were blood grouping or typing, paper analytical device, rapid test, etc. After investigation of search results, 16 papers from 2010 to 2020 were included. Further information in detail was classified in Table 1. Generally, two principles for blood typing μPADs are introduced. The lateral chromatographic flow method and the vertical flow-through method that detects BG in a visual-based manner. To detect results with acceptable clarity many factors and challenges like paper, blood sample, buffer, Ab and RBC interaction and also μPADs stability need to be considered, which are discussed. In conclusion, the simplicity, stability, cheapness, portability and biocompatibility of μPADs for blood grouping confirming its utility and also they have the capability to robust, universal blood-grouping platform. Table 1 Summary of blood grouping tests using paper-based analytical devices Antigens Type of diagnosis Validation method Sample No Accuracy Action time Paper type Stability Sample dilution Buffer Ref A, B, Rh Forward volunteers records 5 - - Whatman No. 4 - 1/2 PBS* (Khan et al. 2010) A, B, Rh Forward gel assay test and conventional slide test 100 100% 1 min Whatman No. 4 and Kleeenex paper towel 7 Days in 4 °C 1/1 NSS (Al-Tamimi et al. 2012) A, B, Rh Forward gel card assay 99 100% 20 Sec + Washing Kleeenex paper towel - 1/1 NSS (Li et al. 2012) A, B, Rh Forward - - - - Kleeenex paper towel - 45/100 PSS (Li et al. 2013) A, B, Rh Forward gel card assay 98 100% 1.5 min Kleeenex paper towel - 85/100 PBS (Guan et al. 2014b) C, E, c, e, K, Jka, Jkb, M, N, S, P1, and Lea Forward gel card assay 266 100% - Kleeenex paper towel - 1/1 NSS (Li et al. 2014b) A, B, Rh Forward and Reverse conventional slide test 96 ≈ 91% 10 min Whatman No. 1 21 Days in 4 °C 1/2 NSS (Noiphung et al. 2015) C, c, E, e, K, k, Fya, Fyb, Jka, Jkb, M, N, S and s, P1, Lea and Leb Forward - 478 - - Kleeenex paper towel - 1/1 NSS, PBS (Then et al. 2015) A, B Forward and Reverse conventional slide test 76 100% 5–8 min Whatman No. 4 38 Days in 4 °C 1/4, 1/1 NSS (Songjaroen and Laiwattanapaisal 2016) D, K Forward volunteers records 210 - 7.5 min Kleenex paper towel - 1/1 NSS (Yeow et al. 2016) A, B, c, e, D, C, E, M, N, S, s, P1, Jka, Jkb, Lea, Leb, Fya, and Fyb Forward and Reverse gel card assay 3550 ≈100% 30 s Fiber glass and cotton linter 180 Days in 25 °C 45/100, 1/1 PBS (Zhang et al. 2017) A, B Forward conventional slide test 598 100% 3 min Whatman No. 113 14 Day in 4 °C 1/1 NSS (Songjaroen et al. 2018) A, B, Rh Forward conventional slide test - - 30 Sec + Washing Unrefined sisal paper - 1/2 NSS (Casals‐Terré et al. 2019) A, B, Rh Forward - - - - Whatman No.1 - 1/1 NSS (Ansari et al. 2020) ABO & Rh Forward and Reverse conventional slide test - 100% Unrefined Eucalyptus papers - 1/2 NSS, PBS (Casals‐Terré et al. 2020) A, B, Rh Forward - - - 30 Sec + Washing Whatman No. 4 modified with chitosan ≥ 100 days in 25 °C 1/1 NSS (Parween et al. 2020) *phosphate buffer saline, normal saline solution [ABSTRACT FROM AUTHOR]

A user-friendly, cost-effectively, portable, and environmentally friendly colorimetric sensor for the quantitative determination of formaldehyde was developed based on the combining of microfluidic paper-based analytical device (μPAD), headspace microextraction (HSME), and digital image colorimetry. Coupling HSME and μPAD led to enhancements in selectivity and sensitivity of the sensor through sample cleanup and analyte enrichment. To construct the μPAD-HSME device, two pieces of paper as the sample and detection zone were placed facing each other so that a small common and sealed space was created between them. The color change occurred when the analyte in the gaseous form crossed this gap and reached the detection zone. Colorimetric sensing in the detection zone was performed based on the Hantzsch reaction. The color change in the detection zone was recorded by a smartphone and digital images were processed using image analysis software based on the RGB model. The influence of some key variables on the sensitivity of the method including derivatization reagent composition, sample volume, extraction temperature, and extraction time was studied and optimized. The linear dynamic range of the method was obtained in two ranges of 0.10–0.75 and 0.75–5.0 mg L−1 with a limit of detection of 0.03 mg L−1. The recoveries were in the range 80–126% for the quantification of formaldehyde in textile, milk, and wastewater samples. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) has been recognized as one of the most sensitive analytical methods by adsorbing the target of interest onto a plasmonic surface. Growing attention has been directed towards the fabrication of various substrates to broaden SERS applications. Among these, flexible SERS substrates, particularly paper-based ones, have gained popularity due to their easy-to-use features by full contact with the sample surface. Herein, we reviewed the latest advancements in flexible SERS substrates, with a focus on paper-based substrates. Firstly, it begins by introducing various methods for preparing paper-based substrates and highlights their advantages through several illustrative examples. Subsequently, we demonstrated the booming applications of these paper-based SERS substrates in abiotic and biological matrix detection, with particular emphasis on their potential application in clinical diagnosis. Finally, the prospects and challenges of paper-based SERS substrates in broader applications are discussed. [ABSTRACT FROM AUTHOR]

In this work, a low-cost and eco-friendly paper-based analytical device (PAD) method is described for the determination of phyto-cannabinoids in cannabis and oral fluids based on a simple colorimetric reaction. The PAD was able to distinguish tetrahydrocannabinol (THC)- and cannabidiol (CBD)-rich plant samples by using 4-aminophenol (4-AP) and later on to quantify total phyto-cannabinoid content (THC + CBD + CBN) in plant and oral fluids by using the Fast Corinth V reagent. The chemical and physical properties regarding paper type and reagent concentration in the PAD were optimized to achieve the best analytical performance. After that, analytical features were obtained, including a linear range of 0.01–0.1 mg mL−1, a limit of detection (LOD) of 0.003 mg mL−1, and a suitable precision, expressed as relative standard deviation (RSD) lower than 10%. Furthermore, no significant interferences were observed in colorimetric reactions when tea, herbs, and drug samples were analyzed. Additionally, the PAD proved color stability up to 1 month after the sampling at 25 °C. The developed PAD was suitable for determining total phyto-cannabinoid content in plants and oral fluids, obtaining good results compared to GC–MS. Overall, this method showed good reliability resulting in an operational on-site device for drug monitoring. [ABSTRACT FROM AUTHOR]

Dyes are one of the main pollutants in the composition of wastewater from various industries. Various chemical and physico-chemical methods are used for the disposal of dyes in aqueous media, of which adsorption is the most effective. The use of activated carbons in water treatment processes is limited by their high price and the need for regeneration. The most acceptable is the use of industrial and agricultural waste as sorption materials. The possibility of using a fibrous waste from industrial production—sludge from waste paper processing—as a sorption material for removing dyes from aqueous media was studied. The use of cellulose-containing production waste is cost-effective, since it does not require the cost of producing new materials, but is an annually renewable plant resource. The use of such materials is also advisable from an economic point of view, since they are natural materials and do not contain any harmful substances in their composition. Information is provided on the processes of waste paper processing that generate waste, including fibrous sludge, which cannot be reused and is transported to sludge storage facilities. The use of the named production waste as a sorption material is proposed. For the preparation of model solutions, methylene blue dye was used as a pollutant, which is a reference compound for analyzing the sorption characteristics of various adsorbents. Some physical and chemical indicators of fibrous waste from waste paper processing are given. It was determined that the maximum sorption capacity of the studied waste was 1.17 mmol/g or 374.3 g/g. The adsorption isotherm of Methylene blue dye on the studied sorption material was constructed and mathematically processed within the framework of Langmuir, Freundlich and Dubinin–Radushkevich models. It was found that the adsorption isotherm is most adequately described by the Langmuir model (R2 = 0.7909). The calculated thermodynamic parameters (adsorption energy and Gibbs energy) indicate the occurrence of a spontaneous physical process. [ABSTRACT FROM AUTHOR]

"Paper mills" are unethical outsourcing agencies proficient in fabricating fraudulent manuscripts submitted to scholarly journals. In earlier years, the activity of such companies involved plagiarism, but their processes have gained complexity, involving the fabrication of images and fake results. The objective of this study is to examine the main features of retracted paper mills' articles registered in the Retraction Watch database, from inception to the present, analyzing the number of articles per year, their number of citations, and their authorship network. Eligibility criteria for inclusion: retracted articles in any language due to paper mill activity. Retraction letters, notes, and notices, for exclusion. We collected the associated citations and the journals' impact factors of the retracted papers from Web of Science (Clarivate) and performed a data network analysis using VOSviewer software. This scoping review complies with PRISMA 2020 statement and main extensions. After a thorough analysis of the data, we identified 325 retracted articles due to suspected operations published in 31 journals (with a mean impact factor of 3.1). These retractions have produced 3708 citations. Nearly all retracted papers have come from China. Journal's impact factor lower than 7, life sciences journals, cancer, and molecular biology topics were common among retracted studies. The rapid increase of retractions is highly challenging. Paper mills damage scientific research integrity, exacerbating fraud, plagiarism, fake images, and simulated results. Rheumatologists should be fully aware of this growing phenomenon. [ABSTRACT FROM AUTHOR]

For shaped charge blasting projects in mining, civil engineering, and similar fields, it is proposed to modify the charge structure by combining slotted tubes and shaped charge liners to obtain a new type of charge structure. This aims to achieve directional rock breaking through the focused action of the shaped charge. The influence of different slotted pipe materials on the directional rock-breaking effect of concentrated energy using a new charge structure is explored through theoretical analysis combined with model test study, high-speed camera, stress–strain gauge, and other equipment. A comparison is made between slotted pipes made of aluminum, kraft paper, and PVC, with the cutting width of 2 mm. Based on the characteristics of the cracks formed after blasting, the new charge structure made of aluminum slotted pipe produces a penetrating crack that is almost consistent with the pre-cracking direction. Based on the corresponding characteristics of successively released blasting energy, the guiding and convergence effect of the new charge structure made of aluminum slotted pipe on the explosion energy is greater than that of the new charge structure made of the other two types of slotted pipe material. According to the strain data measured after blasting, the peak arrival time of the strain peak in the direction of the slotted pipe on one side of the shaped hood is shorter than that in the other two directions, and the peak strain is greater than that in the other two directions while having a better energy gathering effect. Based on the findings, the new charge structure with directional energy concentration has a damage reduction effect. Furthermore, the material of aluminum slotted pipe is found to be better than PVC slotted pipe, whereas the material of PVC slotted pipe is better than kraft paper slotted pipe in achieving directional rock breaking. [ABSTRACT FROM AUTHOR]

Anthraquinone has been widely utilized in the pulp and paper industry as a catalyst for alkaline cooking; however, its application has been recently restricted due to its potential carcinogenic effects. Hence, safer alternatives to anthraquinone have been explored. Agro-industrial by-products have been utilized as sustainable sources of value-added materials. In this study, teak (Tectona grandis) wood waste from Gunung Kidul, Indonesia, which naturally contains lapachol, was utilized as a biocatalyst to enhance delignification and improve pulp yield in alkaline cooking for pulp and paper production. The use of lapachol as a cooking catalyst was investigated for kraft, soda, and prehydrolysis soda cooking. Lapachol accelerated delignification and retained carbohydrate in all three alkaline cooking methods, with its effect being more pronounced in kraft cooking than in soda cooking. This study demonstrates that teak wood extractives with lapachol are promising sustainable catalysts for alkaline cooking. [ABSTRACT FROM AUTHOR]

Rapid and accurate bioburden detection has become increasingly necessary for food, health, pharmaceutical and environmental applications. To detect bioburden accurately, and in a highly sensitive manner, we have fabricated a novel microfluidic device with an integrated filter to trap the cells. Bioburden is detected on the filter paper in situ using the redox reaction of fluorescent label resorufin and a portable multichannel fluorometer is used for fluorescence measurement. The microfluidic device was fabricated in a facile, low-cost, and rapid way with microwave-induced thermally assisted bonding. To characterize the bonding quality of the microfluidic cassettes, different tests were performed, and the filter paper material and size were optimized. Primary Bacillus subtilis culture bacterial samples were filtered through the device to validate and investigate the performance parameters. Our results show that a limit of detection (LOD) of 0.037 CFU/mL can be achieved through this microfluidic device whereas the LOD in a normal microfluidic cassette in the fluorometer and the golden standard spectrophotometer are 0.378 and 0.128 CFU/mL respectively. The results depict that three to ten times LOD improvement is possible through this microfluidic cassette and more sensitive detection is possible depending on the volume filtered within a rapid 3 min. This novel microfluidic device along with the fluorometer can be used as a rapid portable tool for highly sensitive, accurate and high-throughput bacterial detection for different applications. [ABSTRACT FROM AUTHOR]

Tissue products such as facial tissue and paper towels have been playing a crucial role in promoting hygiene and maintaining good health, since they are commonly available and widely used nowadays. The production of low-density tissue paper typically involves a key creping process that contains pressing and adhering the wet web onto a high-speed Yankee cylinder, followed by releasing the creped sheet with a stationary creping blade to form periodic micro-folds within the tissue structure. This paper discusses and reviews the mechanisms of tissue creping technology, as well as the factors that impact the creping process and tissue properties. These factors primarily include the dryness of the tissue web, creping rate, properties of the pulp raw material, Yankee coating, crepe doctor blade, and tissue drying machines. It is indicated that the creping process, as a multifaceted and integrated treatment for tissue production, can be significantly enhanced through the concerted efforts of the aforementioned factors to achieve greater creping efficiency. However, further endeavors are necessary to address the constraints stemming from the pilot experimental equipment and data, as well as modeling simulation, to enable a more comprehensive examination of the creping process and its mechanism. This review offers a practical overview and comprehensive understanding of the creping technology and its underlying factors for tissue production. [ABSTRACT FROM AUTHOR]

As research becomes more interdisciplinary, it is becoming more common for papers not to be published in their own disciplinary journals. This phenomenon is further amplified by the large number of multi-disciplinary journals in China's social sciences, and prompts this study to explore the influence of discipline consistency between papers and published journals on citations. In this study, 476,327 Chinese papers in Economics, Law, and Library & Information Science published between 1998 and 2016 are collected from the Chinese Social Sciences Citation Index (CSSCI) as research samples. Descriptive statistics, Kruskal–Wallis test, Chi-square test, and regression analysis are used to compare the citation count and citation rate between papers published in own disciplinary journals, other disciplinary journals, and multi-disciplinary journals. It is found that papers whose discipline is consistent with published journals have a statistically significant citation advantage, which can be explained by the principle of least effort and scholars' familiarity-based journal evaluation. According to the findings, this study also discusses some issues on the development of multi-disciplinary journals and the usage of citation indicators in academic evaluation. [ABSTRACT FROM AUTHOR]

Recycling is emerging as both a viable alternative to extraction in many industries and a cornerstone of the circular economy. In this paper, we assess the role of paper and cardboard recycling on the forest sector, from both an economic and carbon perspective. For this purpose, we add the recycling industry to an existing forest-sector model in an attempt to capture its effects on other wood products and the overall forest resource. As the forest sector has an important potential for climate change mitigation, this model allows us to assess the effects of increased paper and cardboard recycling on the availability of the natural resource and the carbon balance of the forest sector. We show that these results are strongly linked to the hypotheses of substitutability and/or complementarity of recycled pulp and virgin pulpwood. Although we find increased emissions at the pulp sector level, the effects on emissions in other wood products are small. When pulp products are considered substitutes, we find the impact on total net sequestration to be positive. In the case where pulp products are considered complements, we find the impact on total net sequestration to be negative. [ABSTRACT FROM AUTHOR]

With the widespread application of graphene paper in energy storage, an increasing amount of research is focused on how to enhance its mechanical properties and specific surface area. In this study, flexible porous graphene papers were prepared using a graphene oxide (GO) dispersion and polyurethane diol oligomer (PUO) via electrospray deposition. The improved mechanical properties of the reduced graphene oxide (rGO) papers were attributed to the cross-linking of PUO molecules with the neighbouring GO flakes through π–π stacking and hydrogen bonding interactions during the mixing of the GO dispersion and PUO. In addition, owing to the bursting of the bubbles introduced by PUO during the reduction process, many porous structures appeared inside the rGO paper. The rGO paper performance was adjusted by varying the ratio of PUO content. The optimised rGO paper proved to be excellent for energy storage and oil/water separation. [ABSTRACT FROM AUTHOR]

Urine contains multiple water-soluble hormones, which are valuable non-invasive biomarkers for the monitoring of reproductive status and health. An effective method for drying urine on filter paper was previously developed to preserve wildlife urine samples where electrical equipment was not available for this; however, the stability of samples preserved in this way remains to be verified. Here, we developed and validated a method to elute multiple water-soluble reproductive hormones from filter paper that had been stored for an extended period of time. Aliquots of urine from chimpanzees were adsorbed on filter papers, air dried and stored for 1 year at room temperature. Estrone-3-conjugate (E1C), pregnanediol-3-glucuronide (PdG), estriol-3-glucuronide (E3G), and chorionic gonadotropin (CG) were eluted into deionized water from the filter papers and measured using enzyme immunoassays (EIAs). The mean recoveries of E1C, PdG, and creatinine from filter papers stored for 1 year were 69.5%, 128.7%, and 83.8%, respectively. The profiles of E1C and PdG from preserved filter papers significantly correlated with those derived from a direct analysis of the frozen urine of menstruating chimpanzees. We detected E3G and CG from 1-year-old filter papers for urine collected during early pregnancy, but the recovery of E3G was low and CG profiles did not correlate with those of the original frozen urine samples. The method proposed here for the elution and measurement of reproductive hormones in urine preserved for a long period of time on filter paper provides a practical and simple way to monitor the reproductive status of chimpanzees. We propose that this method can also be utilized in field studies of other wild nonhuman primates. [ABSTRACT FROM AUTHOR]

Global sustainability megatrends are promoting the utilization of sustainably perceived fibers such as recycled and agricultural residue fibers in hygiene tissue applications. Tissue paper products advertised as sustainable have higher prices and inferior performance than conventional products manufactured from virgin wood fibers. This work demonstrates the feasibility of using agricultural residues from fique plantations (Furcraea microphylla genus) as an alternative to Northern Bleached Softwood Fibers (NBSK) in high-performance hygiene tissue applications. For our study, fiber residues were mechanically cleaned and upgraded to a tissue pulp using a simple pulping and bleaching process. A complete characterization of tissue paper properties (bulk, softness, water absorbency, tensile strength) was performed and compared against the NBSK market pulp. Additionally, fique residue pulp was blended with Bleached Eucalyptus Kraft (BEK) to match the performance of a selected benchmark consisting of 70% BEK and 30% NBSK. Results indicate fique residue bleached pulp has similar fiber morphology and comparable strength properties in terms of the tensile strength (+ 6%) and tear strength (+ 10%), but superior bulk (+ 12%), water absorbency (+ 28%), and softness (−29% TS7 values) than NBSK pulp. A fiber blend of 70% BEK and 30% fique residue showed superior tensile strength (+ 21%), tear strength (+ 54%), bulk (+ 5.5%), water absorbency (+ 1.5%), and softness (−8.7% TS7 values) over a similar fiber blend of BEK and NBSK. Our findings demonstrate that fibers from fique residue can substitute NBSK in hygiene tissue applications. Upgrading residues from fique fibers as raw materials for the tissue industry can bridge the gap between sustainability and product performance, simultaneously opening the possibility of new revenue streams for millions of small farmers in the producing countries. [ABSTRACT FROM AUTHOR]

Paper dusting, which occurs when a tissue web releases unbound and loosely bound fibers or filler particles during tissue-making or product manufacturing, has an overall negative impact, causing safety hazards, machine runnability difficulties, and product quality issues. To date, there are no well-established industry standards to quantify dusting/linting propensities in finished tissue products, thus evaluating the effectiveness of dust/lint control programs is challenging yet intriguing. This research aims to fill this gap by developing a methodology to characterize dusting in tissue papers. We have developed a device prototype (named the Tissue Dust Collector) and a methodology that together have been named the Tissue Dust Analysis System (TDAS), which aims at quantifying the propensity for tissue-grade paper products to generate dust/lint in a controlled and reproducible manner. Two samples, corresponding to commercial products with a low and high linting propensity, were tested using the proposed device and methodology, and the released particles were quantified and characterized. The device and methodology provided reproducible results for simulated consumer handling and product manufacturing scenarios. By changing the instrument's motor frequency, the force of agitation changes, mimicking/simulating consumer (60 strokes per min, spm) and producer/manufacturing (180 spm) handling scenarios (though manufacturing processes are much faster in practice). Particle counts at each level for each product showed reproducible values differentiable at different agitation levels. Adopting the proposed Tissue Dust Analysis System may help to characterize and understand the mechanisms behind dusting to create dust-control strategies that can alleviate this issue at its various sources or simply allow tissue paper manufacturers to compare and advertise their products based on dusting propensity. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering (SERS) spectroscopy is an effective approach for trace-level detection of molecular substance. Plasmonic metallic nanostructures with high distribution densities and small gap widths are always expected for constructing SERS substrates. We report here a paper-based SERS substrate, where the three-dimensional (3D) network of paper fibers was used as the platform for supporting the gold nanoparticle clusters. Such a 3D arrangement of plasmonic porous clusters supplies high-density hotspots with large total volume and large surface area for the interaction with molecules. Comparison between different papers found that the filter papers commonly available in labs are the best choice. An enhancement factor higher than 104 has been achieved in the detection of R6G molecules. The preparation of such SERS substrates is very simple and convenient, implying low-cost, disposable, and environment-friendly SERS techniques. Furthermore, the paper-based flexible SERS substrates can be easily tailored into different shapes and sizes for fitting different applications. [ABSTRACT FROM AUTHOR]

Environmental-friendly and high-performance biopolymer-based dielectrics have attracted great attention in light weight and flexible electronics. In this work, the biodegradable TEMPO-oxidized cellulose nanofibrils (TOCNs) were mixed with inorganic mica platelets through vacuum-assisted filtration and subsequent hot-pressing method. It was found that mica platelets could be well aligned within TOCN matrix to form a nacre-like multilayer structure due to good compatibility and hydrogen bonding interaction between mica and TOCNs. The TOCN/mica composite paper shows good flexibility, high mechanical strength (9.8 MPa) and enhanced dielectric breakdown strength (17.85 kV/mm). TOCN/mica papers were further dip-treated by epoxidized soybean oil (ESO) and cured at 170 °C for 2 h. The ESO-treated composite papers show greatly enhanced breakdown strength and reach as high as 175.65 kV/mm for TN-M50/ESO sample. Therefore, these cellulose nanofibrils-based composite papers have shown great potentials in paper insulator in power transformers. [ABSTRACT FROM AUTHOR]

Key summary points: Aim: To describe the evidence on the usefulness of a Comprehensive Geriatric Assessment (CGA)-based approach during the COVID-19 pandemic. Findings: The multidimensional, CGA-based approach allows better identification of individual risk profiles and frailty status of infected, recovered but with a post-COVID-19 condition, and non-infected older adults. Message: Capturing older patients' needs through CGA may offer the possibility to guide clinical decision and implement personalized medicine. Purpose: The COVID-19 pandemic has been a dramatic trigger that has challenged the intrinsic capacity of older adults and of society. Due to the consequences for the older population worldwide, the Special Interest Group on Comprehensive Geriatric Assessment (CGA) of the European Geriatric Medicine Society (EuGMS) took the initiative of collecting evidence on the usefulness of the CGA-based multidimensional approach to older people during the COVID-19 pandemic. Methods: A narrative review of the most relevant articles published between January 2020 and November 2022 that focused on the multidimensional assessment of older adults during the COVID-19 pandemic. Results: Current evidence supports the critical role of the multidimensional approach to identify older adults hospitalized with COVID-19 at higher risk of longer hospitalization, functional decline, and short-term mortality. This approach appears to also be pivotal for the adequate stratification and management of the post-COVID condition as well as for the adoption of preventive measures (e.g., vaccinations, healthy lifestyle) among non-infected individuals. Conclusion: Collecting information on multiple health domains (e.g., functional, cognitive, nutritional, social status, mobility, comorbidities, and polypharmacy) provides a better understanding of the intrinsic capacities and resilience of older adults affected by SARS-CoV-2 infection. The EuGMS SIG on CGA endorses the adoption of the multidimensional approach to guide the clinical management of older adults during the COVID-19 pandemic. [ABSTRACT FROM AUTHOR]

The development of environmentally friendly natural fiber composite materials is desirable. In this study, Urushi (oriental lacquer), which is a natural paint, and Sumi ink (black ink), which is a natural ink, were applied to Washi (Japanese paper), and their effect on the functional properties (appearance, mechanical properties, and water repellency) of the coated Washi were evaluated. Coating the Washi specimens with Urushi significantly improved their water repellency and tensile strength compared to those of untreated Washi. This was because Urushi filled the gaps between the fibers; however, it also caused brittle fracture. In addition, the elongation at break and water repellency were improved when Washi was coated with Sumi ink compared with those of untreated Washi. Furthermore, Washi specimens coated with Sumi ink followed by Urushi exhibited filled gaps between the fibers, a smoother surface, and lower water repellency compared to Washi directly coated with Urushi. The brittle fracture occurred from the Sumi–Washi fiber interface. [ABSTRACT FROM AUTHOR]

We investigated treatment of cellulose paper with a phosphoric acid–urea solution for increasing the wet strength. First, a filter paper was immersed in a phosphoric acid–urea solution (phosphoric acid: urea mole ratio = 1:0, 3:1, 1:1, or 1:3). Next, the filter paper was put between glass plates and heated at 80–140 °C for 15 min to 3 h. Then, the filter paper was washed for 1 h in distilled water. After washing, the filter paper was dried in a hot press at 110 °C and 1.1 MPa for 1 h. We investigated disintegration by immersing the prepared filter papers in distilled water. The paper treated with the 1:3 phosphoric acid–urea solution did not disintegrate. The optimum concentrations for developing the wet strength of the paper were 1.2–2.5 M phosphoric acid and 3.7–7.5 M urea. The optimum treatment time and temperature were 1.5 h and 140 °C, respectively. The wet strength of the paper increased after treatment with the phosphoric acid–urea solution. This method is a viable alternative to treatment with chemicals such as polyamidoamine epichlorohydrin. [ABSTRACT FROM AUTHOR]

Recycled paper pulping wastewater (RPPW) will cause serious environmental problems due to the high loads of dissolved organic matter (DOM) and toxic components. In the present work, the degradation of DOM in the biologically treated RPPWs (cardboard wastewater (CW) and corrugated container wastewater (CCW)) by a combined coagulation and ozonation process was investigated. The optimal chemical oxygen demand (COD) removal of CW reached 73.64% at aluminum sulfate (Al2(SO4)3) dosage of 800 mg/l, aeration aperture of 10 μm, pH of 9, hydrogen peroxide (H2O2) dosage of 100 mg/l, and reaction time of 70 min. The optimal COD removal of CCW reached 55.76% at a poly-aluminum chloride (PAC) dosage of 700 mg/l, H2O2 dosage of 140 mg/l, and reaction time of 50 min. This study provided some insights into the change of DOM during the combined treatment through the use of UV–Vis spectroscopy and excitation-emission matrix spectroscopy (EEM). PAC and Al2(SO4)3 removed high molecular weight organic such as lignin and lignin-derived compounds to improve the biodegradability of the wastewater. Ozone oxidized high molecular weight organic with complex functional groups to low molecular weight organic with simple functional groups and even mineralization, and this phenomenon resulted in the COD of ozonation effluent significantly reduced. Thus, the results presented in this study support the application of the combined coagulation and ozonation process in treating RPPW. [ABSTRACT FROM AUTHOR]

China's pulp and paper industry (CPPI) has been always the main carbon emission source in recent years. However, the analysis on influencing factors of carbon emissions from this industry is insufficient. To address the issue, the CO2 emissions from CPPI are estimated in the period of 2005–2019, the driving factors of CO2 emissions are investigated by the logarithmic mean Divisia index (LMDI) method, the decoupling state of economic growth and CO2 emissions is determined by Tapio decoupling model, and finally, future CO2 emissions are predicted under four scenarios by the STIRPAT model to explore the potential of carbon peaking. The results show that CPPI exhibits a rapid increase and a fluctuating downward trend in CO2 emissions during the period of 2005–2013 and 2014–2019, respectively. The main promoting and inhibiting factors to the increase of CO2 emission are per capita industrial output value and energy intensity, respectively. There are five decoupling states of CO2 emissions and economic growth during the study period, and the CO2 emissions exhibit a weak decoupling state with the industrial output value growth in most years of the study period. It is very difficult to realize the carbon peaking goal by 2030 under the baseline and fast development scenarios. Therefore, efficient low carbon and strong low-carbon development policies are necessary and urgent for the realization of carbon peaking goal and the sustainable development of CPPI. [ABSTRACT FROM AUTHOR]

Toilet paper has been reported as one of the major insoluble pollutant components in the influent of wastewater treatment plants. Toilet paper fibers contribute to a large production of sewage sludge, resulting in a high treatment cost and high energy consumption. To find energy-efficient, cost-effective, and environment-friendly technologies for fiber removal and resource recovery from wastewater, a life-cycle assessment (LCA) was performed to analyze the wastewater treatment processes, including a sieving process for removing and recovering suspended solids before the biodegradation units. Based on the LCA results, it was estimated that the sieve screening process saved 8.57% of energy consumption. The construction phase of sieving consumed 1.31% energy cost compared with the operation phase. Environmental impact analysis showed that sieving reduced the impacts of climate change, human toxicity, fossil depletion, and particulate matter formation, which reduced the total normalized environmental impacts by 9.46%. The life-cycle analysis of the removal of toilet paper fibers from wastewater revealed the need to use more efficient methods to enhance the recovery of cellulose fibers. [ABSTRACT FROM AUTHOR]

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 FROM AUTHOR]

To reduce the fire risk of air filter paper, a reactive ammonium phosphite flame retardant was synthesized and applied to the flame-retarding treatment of air filter paper. It was found that ammonium phosphite reacted with cellulose existing in filter paper fibers to form P–O–C bonds and remarkably improved the flame-retarding properties and thermal stability of the air filter paper. After modification of the air filter paper with 30 wt% of ammonium phosphite, its limiting oxygen index value reached 39.5%, which remained at 29.6% after 4 h of the dipping test. The heat release rate and total heat release rate of the treated air filter paper decreased significantly, and the carbon residual amounts at 700 °C in the nitrogen atmosphere and in air reached 43.96% and 16.35%, respectively. During thermal decomposition, ammonium phosphite played a flame-retarding role in both condensed and gas phases. Moreover, ammonium phosphite, as a flame retardant, had no obvious influence on the physical properties and filtration performance of the air filter paper. [ABSTRACT FROM AUTHOR]

Purpose: The purpose of this study was to investigate associations between digital urine color and paper urine color with other urine indices to assess hydration status. Methods: Twelve male subjects (mean ± standard deviation; age, 26 ± 8 years; body mass, 57.8 ± 5.3 kg; height, 177.5 ± 8.9 cm; VO2max, 57.8 ± 5.8 ml·kg−1·min−1) performed four exercise trials in the heat. Before and following exercise trials, subjects provide urine samples. Urine samples were measured using a digital urine color chart on a portable device screen. Urine samples were also assessed with urine specific gravity (USG), urine osmolality (UOsmo), and a validated paper urine color chart. Results: There were extremely large associations found between digital urine color and paper urine color (r = 0.926, p < 0.001). Correlation coefficients showing associations with USG and UOsmo were similar between digital urine color (USG, r = 0.695, p < 0.001; UOsmo, r = 0.555, p < 0.001) and paper urine color (USG, r = 0.713, p < 0.001; UOsmo, r = 0.570, p < 0.001). Bland–Altman analysis indicated that no proportional bias was observed between digital and paper urine colors (bias, − 0.148; SD of bias, 0.492; 95% LOA, − 1.11, 0.817; p = 0.094). Conclusions: Strong associations were found between digital and paper urine colors with no proportional bias. Furthermore, the degree of associations with USG and UOsmo was similar between digital and paper urine color. These results indicate that digital urine color is a useful tool to assess hydration status and this method could be used as an alternative method to using paper urine color. [ABSTRACT FROM AUTHOR]

While gamified technology integration in vocabulary instruction within a flipped classroom has yielded beneficial teaching outcomes, specific studies have raised concerns about potential adverse effects linked to this approach. As a result, conducting a comparative analysis between gamified technology and conventional paper-based methods within the flipped classroom framework has become essential. This analysis aims to foster the development of a targeted teaching approach that adeptly addresses the unique needs of students. This study employed a sequential explanatory research design to examine the effectiveness of flipped classroom with gamified technology and paper-based method in teaching vocabulary to students with different proficiency levels. Quantitative data was gathered from a pretest and a posttest, whilst qualitative data was collected through teachers' guided reflection. Using Academic Word List (300 target words), control groups employed a paper-based, while experimental groups applied gamified technology (Quizlet, Kahoot!, Quizizz, Socrative, and Google Form), which lasted 10 weeks. The participants were 144 non-English major students who took a general English course in the 2nd semester of 2023. Quantitative data analysis ran in SPSS 25 using Paired Sample t-Test and One-way ANOVA. The qualitative data were analyzed using thematic progression. The results showed that gamified technology did not affect students' learning outcomes, while the paper-based method resulted conversely. It revealed that the paper-based method is more effective than gamified technology for students in general, with low proficiency and high-proficiency level. Further, teachers' beliefs admitted distinctive issues that gamified technology was more effective for high-proficiency learners, whereas paper-based was more effective for low-proficiency learners. The difference analysis of quantitative and qualitative data sheds light on discussing threats while implementing gamified technology and possible solutions. [ABSTRACT FROM AUTHOR]

Sorption properties of paper products are important when applying paper as the packaging material. Hydrophobicity, i.e. reduced affinity of paper surface to liquid water, is of particular importance from the point of view of the direct impact on packed goods. However, hygroscopicity of the material is significant during storage of goods. The analysis of changes in the hygroscopic properties of paper products induced by the treatment with silane modified starch was presented. The results on the hygroscopicity of treated paper were related to the previously published results on the hydrophobicity. The discrete values of equilibrium moisture content allowed constructing adsorption and desorption isotherms. The three-parameter Guggenheim, Anderson, and De Boer (GAB) model, the four-parameter Generalized D'Arcy and Watt (GDW), and Yanniotis and Blahovec (Y-B) sorption isotherm models were used to quantify the hygroscopic properties for all options of untreated and modified paper samples. The effectiveness of silanes for improving hygroscopic properties was determined and compared to their impact on hydrophobicity of the studied materials. It was found that 1H, 1H, 2H, 2H-perfluorooctyltriethoxysilane was the only silane improving hydrophobic and hygroscopic properties. The analysis of the applied models of sorption isotherms depicted that the GAB model was not valid for describing water sorption isotherms in the case of the tested materials, while the GDW and Y-B models provided a much more realistic description of water sorption mechanisms. The evaluation of the results of fitting the GDW model indicated that water molecules bonding to the primary sites was the dominating mechanism of sorption. [ABSTRACT FROM AUTHOR]

Selective and sensitive detection of halides in water is critically important in the diagnosis of diseases and assessment of aquatic ecosystems. The recognition is usually carried out by numerous analytical techniques such as ion chromatography, fluorescence, near-infrared spectroscopy, ion-selective electrode and light scattering. Although these methods offer high sensitivity, they are expensive and time-consuming. Therefore, great efforts have been focused on the sensing of halide anions in water through a simple, fast, low-cost and portable paper-based colorimetric platform. In particular, the sensing process with silver nanoparticles interacting with analytes is of great chemical and biological interest. In this work, anisotropic silver nanoparticles in size and shape embedded in epoxy resin were prepared and subsequently printed on filter papers of cellulose. The influence of water and halide anions (Cl−, Br− and I−) on the morphology of these nanoparticles are investigated by scanning electron microscopy, Raman shift and diffuse reflectance spectroscopy. The mechanism involves aggregation of faceted silver nanoparticles induced by interactions between carbonyl groups of the resin and water. Subsequently, the interaction between halide anions and the aggregated silver nanoparticles causes oxidative etching on their surface, shape conversion (faceted to quasi-spherical shapes), decreasing in the particle size and formation of chain–like or compact aggregates resulting in strong interparticle plasmonic coupling. This selective mechanism was tested for the naked-eye colorimetric recognition of chloride anions in a complex simulated physiological system, whose results show promising perspectives to develop diagnostic-sensing devices. [ABSTRACT FROM AUTHOR]