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Hypochlorous acid (HClO), the core bactericidal substance of the human immune system, plays a vital role in many physiological and pathological processes in the human body. In this work, we designed and synthesized a novel deep-red fluorescent probe TCF-ClO for the determination of hypochlorous acid through theoretical analysis. The results showed that probe TCF-ClO exhibited excellent characteristics of long-wavelength emission (635 nm), fast response ( 1 min), and low detection limit (24 nM). In addition, it had been successfully used for imaging of HClO in living HeLa cells. More importantly, the TCF-ClO composited paper-based sensing material was successfully constructed. The RGB/gray value was obtained from a mobile phone and computer, which could achieve the quantitative detection of HClO, with a linear detection range of 0-50 μM and a detection limit of 1.09 μM (RGB mode)/3.38 μM (gray mode). The function of the paper-based sensor extended from qualitative to quantitative detection of HClO, and it is expected to become a portable device widely used in the environmental area.

Developing fluorescent paper-based materials with recyclable, environmental friendly, excellent stable and uniform performances are still an urgent challenge at present. Herein, a simple, green, and high-efficiency method for the fabrication of high stability and recyclable cellulose-based fluorescent paper from waste bagasse via Hantzsch reaction is proposed. Compared to the pristine paper, the surface modification showed little effect on the morphology, mechanical properties, thermal performance and appearance. Meanwhile, the good writing and printing ability of the paper still remained. The prepared paper showed excellent fluorescence performance, which is very stable even treated with acidic, alkaline, and different solvents for 24 h. It can be processed into different security patterns. What’s more, this strategy could be extended by using other compositions with aldehyde groups. Considering their functional and recyclable features, as well as the convenient and efficient fabrication process, our fluorescent papers hold great potential to be applied in many fields such as anti-counterfeiting.

In this work, the effect of using Ag-doped TiO2 nanopigments on optical, mechanical and antimicrobial properties of coated paper was explored. Furthermore, the long-term antimicrobial activity of the coated paper was examined for up to 25 years. Titanium dioxide (TiO2) nanoparticles have been synthesized and doped with different percentages of Ag nanoparticles (Ag NPs) using a simple wet chemical approach. The Ag@TiO2 modified nanopigments were in the form of nanorods with an average size of about 20 nm as observed from TEM images. Increasing Ag content from 0.01 to 1.0% showed an increase in the mechanical properties of coated paper in terms of tensile, stretching, tensile energy absorption and burst while preserving the optical properties. Moreover, the antimicrobial inhibition activity increased with increasing the Ag content. The 1% Ag@TiO2 showed a long-lasting antimicrobial effect against Staphylococcus aureus (S. aureus) Gram-positive bacteria even after 25 years of ageing (93.4% inhibition). Investigation of reactive oxygen species (ROS) generation and reaction mechanism of antimicrobial activity over Ag/TiO2 under visible light is proposed. These results suggest that Ag/TiO2 NPs can be potentially used as a disinfection coating for paper and improving its mechanical properties. Graphical abstract

The following paper presents a construct for a paper-based device which utilizes latex as the hydrophobic material for the fabrication of its hydrophobic barrier, which was deposited onto the cellulose surface either by free-hand or stenciled drawing. This method demands the least amount of expertise and time from its use, enabling a simple and rapid fabrication experience. Several properties of the hydrophobic material were characterized, such as the hydro head and penetration rate, with the aim of assessing its robustness and stability. The presented hydrophobic barriers fabricated using this approach have a barrier width of 4 mm, a coating thickness of 208 µm, and a hydrophilic resolution of 446.5 µm. This fabrication modality boasts an excellent solvent resistance with regard to the hydrophobic barrier. These devices were employed for on-the-spot detection of Metanil Yellow, a banned food adulterant often used in curcumin and pigeon peas, within successful limits of detection (LOD) of 0.5% (w/w) and 0.25% (w/w), respectively. These results indicate the great potential this fabricated hydrophobic device has in numerous paper-based applications and other closely related domains, such as diagnostics and sensing, signalling its capacity to become commonplace in both industrial and domestic settings.

"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.

Iron is an important micronutrient involved in several mechanisms in the human body and can be an important biomarker. In this work, a simple and disposable microfluidic paper-based analytical device (µPAD) was developed for the quantification of iron in urine samples. The detection was based on the colorimetric reaction between iron(II) and bathophenanthroline and the reduction of iron(III) to iron(II) with hydroxylamine. The developed µPAD enabled iron determination in the range 0.07–1.2 mg/L, with a limit of detection of 20 µg/L and a limit of quantification of 65 µg/L, thus suitable for the expected values in human urine. Additionally, targeting urine samples, the potential interference of the samples color was overcome by incorporating a sample blank assessment for absorbance subtraction. Stability studies revealed that the device was stable for 15 days prior to usage and that the formed colored product was stable for scanning up to 3 h. The accuracy of the developed device was established by analyzing urine samples (#26) with the developed µPAD and with the atomic absorption spectrometry method; the relative deviation between the two sets of results was below 9.5%. Graphical abstract: [Figure not available: see fulltext.]

The adsorption of locust bean gum (LBG) onto Northern Bleached Softwood Kraft (NBSK) pulp improved paper tensile and burst strength and lowered refining energy by strengthening inter-fibre bonding. Adsorption kinetics and isotherms were investigated to develop a fundamental understanding of the adsorption mechanism. The adsorption rate followed pseudo-second-order kinetics and the activation energy was 99.34 kJ·mol−1, suggesting chemisorption. The adsorption rate constant increased rapidly with temperature from 25 to 45 °C (k = 1.93 to 24.03 g·mg−1·min−1), but the amount adsorbed at equilibrium decreased (qe = 1.91 to 0.48 mg·g−1 o.d. fibre). LBG adsorption to NBSK at 25 °C was consistent with the Langmuir adsorption model for LBG n = 5.00, and the equilibrium constant Kf = 2.57 mg·g−1·(mg·L−1)−1/n at 25 °C. Favorable adsorption conditions for negatively charged LBG were identified: 25 °C for 10 min, low dosage level ( 150 r.p.m.), acidic or neutral conditions (pH 2–7) without salt addition. Graphic abstract

The pulp and paper industry discharges massive amount of wastewater containing hazardous organochlorine compounds released during different processing stages. Therefore, some cost-effective and nonpolluting practices such as enzymatic treatments are required for the potential mitigation of effluents released in the environment. Various xylanolytic enzymes such as xylanases, laccases, cellulases and hemicellulases are used to hydrolyse raw materials in the paper manufacturing industry. These enzymes are used either individually or in combination, which has the efficient potential to be considered for bio-deinking and bio-bleaching components. They are highly dynamic, renewable, and high in specificity for enhancing paper quality. The xylanase act on the xylan and cellulases act on the cellulose fibers, and thus increase the bleaching efficacy of paper. Similarly, hemicellulase enzyme like endo-xylanases, arabinofuranosidase and β-d-xylosidases have been described as functional properties towards the biodegradation of biomass. In contrast, laccase enzymes act as multi-copper oxidoreductases, bleaching the paper by the oxidation and reduction process. Laccases possess low redox potential compared to other enzymes, which need some redox mediators to catalyze. The enzymatic process can be affected by various factors such as pH, temperature, metal ions, incubation periods, etc. These factors can either increase or decrease the efficiency of the enzymes. This review draws attention to the xylanolytic enzyme-based advanced technologies for pulp bleaching in the paper industry.

Free-standing reduced graphene oxide (rGO) papers were prepared by chemical reduction, thermal reduction and combined chemical-thermal reduction, respectively. Four-point probe and nanoindentation experiments were conducted to investigate the electrical and mechanical properties of rGO papers. The rGO paper prepared by soaking in L-ascorbic acid and thermal annealing in argon at 1000 °C (labeled rGO-AsA-T) showed superior electrical and mechanical properties when compared with rGO papers prepared merely by chemical reduction or thermal reduction. The as-prepared rGO-AsA-T paper exhibited an electrical conductivity of 5.7 × 104 S/m, showing an increase of 90% compared to that in the thermally annealed rGO paper and nearly 40 times that of rGO paper reduced by L-ascorbic acid. It was also found that the rGO-AsA-T paper had the lowest elastic modulus of 288 MPa, showing enhanced flexibility. The nearly free voids in rGO-AsA-T paper proved by scanning electron microscopy (SEM) were due to the capillary action in chemical reduction and were significant in improving the electrical conductivity and flexibility of the paper. The rGO-AsA-T paper with high conductivity and flexibility has a promising application in flexible electronics.

The outbreak of new viral strains promotes advances in universal diagnostic techniques for detecting infectious diseases with unknown viral sequence. Long double-stranded RNA (dsRNA), a hallmark of infections, serves as a virus marker for prompt detection of viruses with unknown genomes. Here, we report on-chip paper electrophoresis for ultrafast screening of infectious diseases. Negatively charged RNAs pass through the micro and nanoscale pores of cellulose in order of size under an external electric field applied to the paper microfluidic channel. Quantitative separation of long dsRNA mimicking poly I:C was analyzed from 1.67 to 33 ng·μL−1, which is close to the viral dsRNA concentration in infected cells. This paper-based capillary electrophoresis chip (paper CE chip) can provide a new diagnostic platform for ultrafast viral disease detection at the point-of-care (POC) level.

The coronavirus (COVID-19) pandemic disrupted all surgical specialties significantly and exerted additional pressures on the overburdened United Kingdom (UK) National Health Service. Healthcare professionals in the UK have had to adapt their practice. In particular, surgeons have faced organisational and technical challenges treating patients who carried higher risks, were more urgent and could not wait for prehabilitation or optimisation before their intervention. Furthermore, there were implications for blood transfusion with uncertain patterns of demand, reductions in donations and loss of crucial staff because of sickness and public health restrictions. Previous guidelines have attempted to address the control of bleeding and its consequences after cardiothoracic surgery, but there have been no targeted recommendations in light of the recent COVID-19 challenges. In this context, and with a focus on the perioperative period, an expert multidisciplinary Task Force reviewed the impact of bleeding in cardiothoracic surgery, explored different aspects of patient blood management with a focus on the use of haemostats as adjuncts to conventional surgical techniques and proposed best practice recommendations in the UK.

Instituto de Salud Carlos III, European Union - NextGenerationEU, Recovery, Transformation and Resilience Plan RD21/0017/0001

This article reviews Bram Büscher’s book The Truth about Nature: Environmentalism in the Era of Post-truth Politics and Platform Capitalism (2021).