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Printable biosensors have gained numerous exciting advancements towards downstream applications in fundamental biomedical research, healthcare, food safety, environmental monitoring and governance, and to name a few. Particularly, paper-based printable biosensors have gained rising popularity in providing affordable platforms due to their merits, such as cost-effective, accurate, simple, and efficient detection of diseases for clinical diagnosis. In addition to advantages and opportunities in point-of-care detection, printable biosensors are also facing challenges. Herein, this review aims to provide a systematic summary of the development of printable biosensors, with a special focus on paper-based printable biosensors. Different types of substrates for printable biosensors are highlighted first. Then we mainly focus on paper substrates with superior properties like low-cost, simple, flexible, lightweight, recyclable, etc. In addition, current printing technologies to fabricate paper-based sensors, including wax printing, photolithography, screen printing, inkjet printing, and laser printing summarize, are discussed, together with strategies for biomolecular fabrication on substrates and transducers. Finally, we also discuss the challenges and possible future perspectives, hoping to provide researchers and clinicians with informative insights into paper-based printable biosensors for a smart and effective point-of-care purpose.

To extend the application of cost-effective high-yield pulps in packaging, strength and barrier properties are improved by advanced-strength additives or by hot-pressing. The aim of this study is to assess the synergic effects between the two approaches by using nanocellulose as a bulk additive, and by hot-pressing technology. Due to the synergic effect, dry strength increases by 118% while individual improvements are 31% by nanocellulose and 92% by hot-pressing. This effect is higher for mechanical fibrillated cellulose. After hot-pressing, all papers retain more than 22% of their dry strength. Hot-pressing greatly increases the paper’s ability to withstand compressive forces applied in short periods of time by 84%, with a further 30% increase due to the synergic effect of the fibrillated nanocellulose. Hot-pressing and the fibrillated cellulose greatly decrease air permeability (80% and 68%, respectively) for refining pretreated samples, due to the increased fiber flexibility, which increase up to 90% using the combined effect. The tear index increases with the addition of nanocellulose, but this effect is lost after hot-pressing. In general, fibrillation degree has a small effect which means that low- cost nanocellulose could be used in hot-pressed papers, providing products with a good strength and barrier capacity.

Internationally, teachers use oral reading fluency (ORF) measurements to monitor learning progress in reading and adapt instruction to the individual needs of students. In ORF measures, the child reads aloud single syllables, words, or short passages, and the teacher rates in parallel at which items the child makes a mistake. Since administering paper-based ORF requires increased effort on the part of teachers, computer-based test administration is available. However, there are still concerns about the comparability of paper-based and computer-based test modes. In our study, we examine mode effects between paper-based and computer-based test scores for both reading speed and reading accuracy using a German-language ORF assessment for progress monitoring. 2nd- and 3rd-year-students (N = 359) with and without special education needs participated in the study. Results show comparable and high reliability (r > 0.76) and no differential item functioning for both test modes. Furthermore, students showed significantly higher reading speed on the paper-based test, while no differences were found in reading accuracy. In the absence of differential item functioning, we discuss how mean differences can be accounted for, how teachers can be trained to use the different test modes, and how computer-based tests can be safeguarded in practice.

Paper-based friction material is a typical paper-based composite that is usually cured via hot-pressing. This curing method does not account for the effect of pressure on the matrix resin, resulting in uneven distribution of resin in the material and reducing the mechanical properties of friction materials. To overcome the above shortcomings, a pre-curing method was introduced before hot-pressing, and the effects of different pre-curing degrees on the surface morphology and mechanical properties of paper-based friction materials were studied. The pre-curing degree significantly affected the resin distribution and interfacial bonding strength of the paper-based friction material. When the material was cured at 160 °C for 10 min, the pre-curing degree reached 60%. At this point, most of the resin was in a gel state, which could retain abundant pore structures on the material surface without causing mechanical damage to the fiber and resin matrix during hot-pressing. Ultimately, the paper-based friction material exhibited improved static mechanical properties, decreased permanent deformation, and reasonable dynamic mechanical properties.

Packaging is defined as the enclosement and protection of products for their distribution, storage, sale, consumption, and use [1], with the preferred material being paper and cardboard-based packages. Taking this into consideration, by 2021 the global paper industry reported a market value of 372.34 billion USD [2] and a production volume of approximately 417.3 million metric tonnes [3]. Therefore, when assessing global waste composition trends, it is not surprising to find that the most prominent stream after organic waste corresponds to paper and cardboard with a 17% representation [4]. Considering the above as well as the Sustainable Development Goals (SDG) tackling sustainable consumption and production patterns (Goal 12), the necessity to take urgent action to combat climate change and its impacts (Goal 13), and sustainably manage forests, combat desertification, halt and reverse land degradation and halt biodiversity loss (Goal 15), the following research had as its main objective to measure the impact of commonly used inks, coatings, varnishes, and decorations in paper and cardboard packaging repulpability according to the American Fibre Box Association (FBA) repulpability standard. Ten (10) samples employing digital printing – 2 samples – Offset printing in cardboard packages – 5 samples – and Offset printing in paper labels – 3 samples – were sourced from Kaunas University of Technology Publishing House and packaging manufacturer Trustpack, Lithuania. Results show that 3 out of the 10 samples produced more than 15% of rejects, and therefore cannot be considered repulpable. Additionally, the 3 samples show the inclusion on foil paints or metallized engravings, which supports the conclusion that the addition of such materials to the packaging significantly reduce the amount of recoverable material., Pakuotė apibrėžiama kaip produktų uždengimas ir apsauga, skirta jų platinimui, laikymui, pardavimui, vartojimui ir naudojimui [1], o populiariausia medžiaga yra popierinės ir kartoninės pakuotės. Atsižvelgiant į tai, iki 2021 m. pasaulinės popieriaus pramonės rinkos vertė siekė 372.34 mlrd. dolerių [2], o gamybos apimtis - apie 417,3 mln. metrinių tonų [3]. Todėl, vertinant pasaulines atliekų sudėties tendencijas, nenuostabu, kad po organinių atliekų svarbiausią srautą atitinka popierius ir kartonas, kurių dalis sudaro 17 % [4]. Atsižvelgiant į tai, kas išdėstyta pirmiau, taip pat į Darnaus vystymosi tikslus (DVT), kuriuose sprendžiamas tvaraus vartojimo ir gamybos modelių klausimas (12 tikslas), būtinybę imtis skubių veiksmų kovojant su klimato kaita ir jos poveikiu (13 tikslas), tvariai tvarkyti miškus, kovoti su dykumėjimu, sustabdyti ir pakeisti žemės degradaciją ir sustabdyti biologinės įvairovės nykimą (15 tikslas), šio tyrimo pagrindinis tikslas buvo įvertinti dažniausiai naudojamų rašalų, dangų, lakų ir dekoracijų poveikį popieriaus ir kartono pakuočių atstūmimui pagal Amerikos pluošto dėžučių asociacijos (FBA) atstūmimo standartą. Dešimt (10) pavyzdžių, kuriuose naudota skaitmeninė spauda - 2 pavyzdžiai, ofsetinė spauda kartoninėse pakuotėse - 5 pavyzdžiai ir ofsetinė spauda popierinėse etiketėse - 3 pavyzdžiai, buvo gauti iš Kauno technologijos universiteto leidyklos ir pakuočių gamintojo Trustpack, Lietuva. Rezultatai rodo, kad 3 iš 10 pavyzdžių buvo gauta daugiau kaip 15 % broko, todėl jų negalima laikyti atpažįstamais. Be to, šiuose 3 mėginiuose matyti, kad į pakuotę įtraukta ant folijos dažų arba metalizuotų graviūrų, o tai patvirtina išvadą, kad tokių medžiagų įtraukimas į pakuotę gerokai sumažina atgautinos medžiagos kiekį.

Paper has gained popularity as a packaging material due to its reduced environmental impact compared with non-degradable alternatives. However, its flammability poses safety risks, prompting research on enhancing its flame retardancy. This work introduces a diffusion-driven self-assembly strategy (DDSAS) to create a functional graphene oxide (GO) coating on various packaging papers. DDSAS involves infiltrating the paper’s cellulose microfiber network with branched polyethyleneimine (b-PEI), which binds firmly to cellulose microfibers. Electrostatic interactions between GO and b-PEI then drive GO assembly into a densely stacked, layered structure on the paper surface. This GO structure provides a physical barrier against flames and generates incombustible gases (CO2, H2O, NO2, and NO) when heated, diluting the surrounding oxygen concentration and acting as a heat insulation layer. These factors increase the flame retardancy of treated papers ten-fold. Additionally, the gradual reduction of GO upon heating forms reduced graphene oxide (rGO) on the paper, significantly increasing its electrical conductivity. As a result, the flame-retardant papers not only prevent the fire from spreading but can also act as fire sensors by triggering an alarm signal at the early stages of contact with fire. In summary, this work offers a rational strategy for designing and manufacturing flame-retardant paper packaging materials.

This article presents results on the use of a new material as a solidifying agent and/or color-fixing agent. A special polysaccharide material extracted from the prickly pear cactus (Opuntia ficus indica) was tested on historical materials and modern papers. An old book from the 18th century was chosen as historical material. From the mentioned book 42 pages were taken, on which a conservation and restoration pretreatment was performed before applying the polysaccharide material: sampling, fiber analysis, dry cleaning, ink solubility, pH test, thickness measurement and wet cleaning. The paper sheets provided for the test were divided into 4 groups, 3 of which were treated with gel and one left untreated as a reference. The division into groups is not only due to the different method of application, but also due to the process of gel extraction. The effect of the treatment was analyzed using FTIR-ATR. To test the mucilage as color-fixing agent 2 samples were prepared using watercolor papers colored with 6 different watercolors applied to 2.5 cm2 samples for each color in two rows of different intensity. One of the 2 samples was treated with gel, but both were immersed for 3 times in a water-ethanol solution for approximately 20 min as is standard practice in conservation and restoration. After washing, both specimens were subjected to colorimetric analysis to assess their differences. The results provided satisfactory evidence for the protection of paints sensitive to aqueous treatments and suggest the use of mucilage as a new material in cleaning method for water-soluble media.

Compared to students in other countries, Japanese university students tend to sleep less. Because there are many individual differences in sleep habits, a specific intervention is not necessarily appropriate. In this study, the sleep habits of university students were investigated using a sleep diary during a semester. Participants were 13 undergraduates who completed sleep diaries for one consecutive week on three separate occasions during the semester. The results showed that university students' sleep habits could be divided into three groups. While one group had no subjective sleep disorders, the other two groups reported poor sleep quality and went to bed late: one of the group tended to wake up early and sleep shorter, and the rest woke up later. Changes in bedtime were observed throughout the semester. University students may try to cope with events during the semester by changing their bedtimes. This study revealed that time management that keeps bedtime ahead of schedule without shifting the wake-up time through the semester is important for students with sleep difficulty. (150 – 200 words)

The object of research in this scientific paper is the treatment of waste generated by paper production in industrial landfills. In the part of the paper production process, i.e. in its subsystem for wastewater treatment, a significant amount of solid waste is generated, which ends up in industrial landfills. The reason for the impossibility of returning to the production process lies in the fact that the sludge contains larger amounts of moisture and present chemical components that are isolated in the paper production process or during wastewater treatment. In the experimental part of the paper, a “trial plot” was selected on which seedlings of the paulownia elongate plant were planted in the waste sludge. The process of plant growth was monitored for two years and bioremediation, i.e. transfer of elements from sediments to plants, was analysed by modern instrumental methods. Based on the results obtained by research, it can be said with certainty that Paulownia elongate can be used in bioremediation of areas where these sediments are deposited.

In an article to study the effect of sizing agent and filler on the structural features of paper from the cellulose mass of the inner layer of the bark of mulberry tree branches, mechanical strength, absorbency and sorption properties were studied. Tensile strength was determined on a tensile testing machine by the force causing the destruction of the sample. Surface absorbency at one side wetting was determined by the method of Cobb(30), by determining the mass of water absorbed by the surface of the paper when wetting one side of the test sample. Sorption properties were studied on a high-vacuum setup with mercury gates and McBain quartz balances according to water vapor sorption data. It was found that the internal 2% sizing of the paper pulp with cherry tree resin glue contributes to the strengthening of the paper structure, which is confirmed by the values of mechanical strength and surface absorbency when unilaterally wetted with water, relative to the values obtained when sizing with pine oleoresin rosin glue. When using glue from cherry resin, it is advisable to add 2 g of kaolin to 100 g of pulp from the inner layer of the bark of mulberry tree branches, since the increase negatively affects mechanical strength and hydrophobicity., В статье для исследования влияния проклеивающего вещества и наполнителя на структурные особенности бумаги из целлюлозной массы внутреннего слоя коры веток тутового дерева изучены механическая прочность, впитывающая способность и сорбционные свойства. Прочность на разрыв при растяжении определяли на разрывной машине по усилию, вызывающему разрушение образца. Поверхностную впитываемость при одностороннем смачивании определяли по методу Кобб(30), путем определения массы воды, поглощенной поверхностью бумаги при смачивании одной стороны испытуемого образца. Сорбционные свойства исследовали на высоковакуумной установке с ртутными затворами и кварцевыми весами Мак-Бена по данным сорбции паров воды. Выявлено, что внутренняя 2%-ная проклейка бумажной массы клеем из живицы черешневого дерева способствует упрочнению структуры бумаги, что подтверждается значениями механической прочности и поверхностной впитываемостью при одностороннем смачивании водой, относительно значений, полученных при проклейке канифольным клеем из сосновой живицы. При использовании клея из живицы черешневого дерева целесообразно к 100 г целлюлозной массы из внутреннего слоя коры веток тутового дерева добавлять каолин в количестве 2 г, так как увеличение отрицательно влияет на механическую прочность и гидрофобность.

Lead (Pb) pollution from local mines and industrial use increases risks for human, animal, and plant health. Pectin is an effective chelator of Pb, and it has been shown that a unicellular green alga, Penium margaritaceum, synthesizes pectin in the cell wall. In this study, the ability of P. margaritaceum to remove Pb from an aqueous solution was investigated. Energy dispersive X-ray spectroscopy revealed that two strains of P. margaritaceum accumulated Pb on the cell surface. Hence, P. margaritaceum cells were immobilized on cellulose filter paper. The immobilized algal cells were soaked in 1.0 mg/L Pb solution with gentle shaking for 8 h, and Pb in the solution and on the filter paper was measured by flame atomic absorption spectrometry. The immobilized algal cells continuously decreased the Pb concentration to less than 0.5 mg/L and recovered 31.8–32.7% of added Pb. The specific decrease in Pb and increase in Ca were observed in the presence of 1.0 mg/L each of Ca, Mg, Na, and K. Fourier transform infrared spectra suggested that the carboxylic acid group would be responsible for the adsorption of Pb. This study is the first to demonstrate the effectiveness of the immobilized P. margaritaceum cell in removing Pb from aqueous solutions with simple solid–liquid separation.

Four organic solid wastes (coffee grounds, ground nut shell, paper money sewage sludge and cork powder) have been investigated as bloating inducing agents in lightweight aggregate (LWA) manufacturing when mixed in small proportions (2.5 wt.%) with three types of clays. The pellets obtained were fired in a rotary kiln at the maximum feasible temperature for 4 min. A similar impact was observed both in the working conditions and in the properties of the LWAs, showing that the differences between said residues are not as decisive as those of the clays to which they are added. The organic wastes have played a crucial role in achieving reducing conditions inside the aggregate. Thus, their addition has led to substantial improvements both from an operational point of view, lowering the working temperature, and from a technological perspective, favoring bloating and the development of a highly porous and lightweight structure. Leachate studies have shown that the LWAs meet the regulatory limits. The outcomes of this investigation show that, in line with the precepts of the Circular Economy, the recovery of organic wastes of different nature can have a place in the production of environmentally friendly LWAs