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Paper Spray Ionization (PSI) is commonly applied for the analysis of small molecules, including drugs, metabolites, and pesticides in biological fluids, due to its high versatility, simplicity, and low costs. In this study, a new setup called Solvent Assisted Paper Spray Ionization (SAPSI), able to increase data acquisition time, signal stability, and repeatability, is proposed to overcome common PSI drawbacks. The setup relies on an integrated solution to provide ionization potential and constant solvent flow to the paper tip. Specifically, the ion source was connected to the instrument fluidics along with the voltage supply systems, ensuring a close control over the ionization conditions. SAPSI was successfully applied for the analysis of different classes of biomolecules: amyloidogenic peptides, proteins, and N-glycans. The prolonged analysis time allowed real-time monitoring of processes taking places on the paper tip, such as amyloid peptides aggregation and disaggregation phenomena. The enhanced signal stability allowed to discriminate protein species characterized by different post translational modifications and adducts with electrophilic compounds, both in aqueous solutions and in biofluids, such as serum and cerebrospinal fluid, without any sample pretreatment. In the next future, application to clinical relevant modifications, could lead to the development of quick and cost-effective diagnostic tools.

We present a simple all-in-one paper-based sensor for E. coli detection using a composite ink made of a fluorogenic DNAzyme probe for bacterial recognition and signal generation, lysozyme that lyses whole bacterial cells, and pullulan/trehalose sugars that stabilize printed bioactive molecules. The paper sensor is capable of producing a fluorescence signal as a readout within 5 minutes upon contacting E. coli, can achieve a limit of detection of 100 cells/mL, in a variety of sample matrixes, without sample enrichment, and remains stable for at least 6 months when stored at ambient temperature. Therefore, this simple paper sensor provides rapid bacterial testing on site, and can be shipped and stored under ambient conditions to benefit users living in resource-limited regions.

Industrially produced copy paper is presented as a novel optical material for narrow-band stimulated emission. Fluorescent brightening agents (FBA) such as Calcofluor White provide enough gain to exceed the threshold for amplified spontaneous emission. By applying an additional dye such as Coumarin 307, or simply a highlighter pen, the emission line can be shifted from blue (~440 nm), towards turquoise (>480 nm), up to orange (590 nm) which can be useful for spectroscopic applications. These properties are demonstrated in two papers, a commercial copy paper and a FBA-stained calligraphy paper.

Development of cost-effective and environmentally friendly manufacturing methods will enable important advances for the production of large-scale flexible electronics. Laser processing has shown to be a promising candidate that offers a fast and non-destructive way to produce highly conductive patterns on flexible substrates such as plastics. However, an emerging option with a lower environmental impact is instead the use of cellulose-based flexible substrates, such as paper. In this work we investigate the use of laser sintering of silver nanoparticle inks, which were inkjet-printed on three different types of paper. Patterns with a high conductivity could be manufactured where a special care was taken to prevent the substrates from damage by the intense laser light. We found that the best results was obtained for a photopaper, with a conductivity of 1.63 ∗ 107 S/m corresponding to nearly 26% of the bulk silver conductivity. In addition, we demonstrate laser sintering to fabricate a fully functional near field communication tag printed on a photopaper. Our results can have an important bearing for the development of cost-effective and environmentally friendly production methods for flexible electronics on a large scale.

Sugarcane bagasse is a significant renewable energy source for the sugar and bioethanol industries. Bagasse ash is the waste from the combustion process and is mostly disposed of as landfill. Only a small quantity of bagasse ash is utilized as pozzolan in concrete, and a considerable quantity is left unused due to its high carbon and crystallite content. Generally, bagasse ash is rich in silica (SiO2), and it is thus an alternative source for silica extraction. In this paper, a low-energy and low-chemical consumption method is proposed to obtain silica from bagasse ash using alkali extraction and acid precipitation. The physical and chemical properties of the extracted silica are described. A silica yield of 80% and moisture absorption of 73% were achieved. The silica had amorphous phases and was light gray in color owing to the presence of carbon from incomplete combustion. Bagasse silica was used as an extender filler in an expensive photochromic pigment to increase the bulk volume. It was found that a pigment-to-silica mass ratio up to 1:10 could be used for thick-layer painting. However, a ratio of up to 1:3 is recommended for thin-layer screen-printing on fabrics. The bagasse ash silica-pigment blends have very good color fastness when washing; however, frequent aggressive washing should be avoided.

Cellulose nanofibers were obtained from the Colombian fique (Furcraea bedinghausii) and Acrylic hydrogels (H) and reinforced acrylic hydrogels with fique nanofibres (HRFN) were synthesized, using the solution polymerization method. The extraction was carried out using a combined extraction method (chemical procedures and ultrasound radiation). The raw material (NAT-F), bleached fibers (B-F), hydrolyzed fibers and fibers treated with ultrasound (US-F) were characterized by infrared spectroscopy (FTIR) and thermal stability analysis; also, in order to have a comparison criterion, a commercial microcrystalline cellulose sample (CC) was analyzed, which demonstrated the extraction of fique cellulose. The surface morphology of the NAT-F and the B-F was determined by scanning electron microscopy and the average particle size of the nanofibers was made through transmission electron microscopy. In H y HRFN the strain percent and compression resistance (Rc) were measured. The fique nanofibers showed diameter and length averages of 25.2 ± 6.2 nm and 483.8 ± 283.2 nm respectively. Maximum degradation temperature was 317 °C. HRFN presented higher compression resistance (16.39 ± 4.30 kPa) and this resistance was 2.5 greater than the resistance of H (6.49 ± 2.48 kPa). The results indicate that fique lignocellulosic matrix has potential application for obtaining polymeric type composite materials.

Microbial fuel cell (MFC) technology is a simple way to accelerate the treatment of the oily sludge which is a major problem affecting the quality of oil fields and surrounding environment while generating electricity. To investigate the oil removal and the characteristics of changes in the composition of bacteria, sediment microbial fuel cells (SMFCs) supplemented with oily sludge was constructed. The results showed that the degradation efficiency of total petroleum hydrocarbon (TPH) of SMFC treatment was 10.1 times higher than the common anaerobic degradation. In addition, the degradation rate of n-alkanes followed the order of high carbon number > low carbon number > medium carbon number. The odd–even alkane predominance (OEP) increased, indicating that a high contribution of even alkanes whose degradation predominates. The OUT number, Shannon index, AEC index, and Chao1 index of the sludge treated with SMFC (YN2) are greater than those of the original sludge (YN1), showing that the microbial diversity of sludge increased after SMFC treatment. After SMFC treatment the relative abundance of Chloroflexi, Bacteroidia and Pseudomonadales which are essential for the degradation of the organic matter and electricity production increased significantly in YN2. These results will play a crucial role in improving the performance of oily sludge MFC.

Lipids in sewage sludge are considered to be high-class raw materials for biodiesel or other valuable products. We profiled the characteristics and assessed the reutilization potential of lipids from different sludge sources, including sludge from the primary sedimentation tank (PST sludge) and sludge from the secondary sedimentation tank in a conventional activated sludge system (CAS sludge), as well as sludge from ultrashort-sludge retention time (SRT) activated sludge systems with different SRTs (USAS sludge, with SRTs of 0.5, 1.0, 2.0, 3.0 and 4.0 d). The results showed that the lipids in the sludges were mainly composed of cellular lipids, free fatty acids (FFAs), wax and gum. The highest lipid content was found in the PST sludge (156.8 ± 11.9 mg/g, dry basis), followed by the USAS sludges (67.9 ± 11.0–132.2 ± 11.8 mg/g) and the CAS sludge (46.0 ± 16.5 mg/g). Lipid species such as Cer, So, PE, PC, and TG were abundant, comprising over 80% of the cellular lipids in the sludges. With higher lipid contents, the PST sludge and USAS sludge (0.5 d SRT) were suggested to have a higher reutilization potential for use in producing biodiesel. In addition, the CAS sludge was promising for resource reutilization and energy recovery due to the large amount of excess sludge.

The management of large amounts of eggshell waste annually produced in the world is problematic as generally this material is only disposed at landfills with odor production and microbial growth. On the contrary, significant environmental and economic advantages could be obtained transforming this biowaste into new value-added products. Eggshell biowaste was the starting material for the synthesis of hydroxyapatite by a simple and sustainable procedure and applied for the removal of Co2+ from aqueous solutions. The effects of contact time and initial metal concentration were investigated in batch experiments. Eggshell-based hydroxyapatite (ESHAP) before and after Co2+ removal was characterized by X-ray diffraction and scanning electron microscopy. The process was rapid and reached equilibrium within 80 min. The removal efficiency was in the range 70–80% which is generally higher than other waste-derived adsorbents. Adsorption of Co2+ on the surface of ESHAP particles and ion exchange with Ca2+ resulting in the formation of a Co-phosphate are the main mechanisms of the metal removal. The conversion of eggshell waste to a low-cost adsorbent for the treatment of metal contaminated waters could contribute to a more sustainable and effective management of this biowaste.

Wood chips or particles as well as shredded straw offer desired thermal insulation qualities. When exposed to a humid environment, however, fungal growth on wood and straw is an important consideration. An experimental investigation was conducted in order to evaluate the effectiveness of a simple treatment in mitigating fungal growth on wood- and straw-based insulation. This treatment involved blending of wood chips or particles, or shredded straw with an aerated slurry which offers the potential to mitigate fungal growth on biomass by a combination of physical and chemical effects without imposing a weight penalty. Experimental results verified the effectiveness of this treatment in controlling fungal growth on wood and straw subjected to different moisture conditions.

The biosorption capacities of dried meal and a waste product from the processing for biostimulant extract of Ascophyllum nodosum were evaluated as candidates for low-cost, effective biomaterials for the recovery of indium(III). The use of indium has significantly grown in the last decade, because of its utilization in hi-tech. Two formats were evaluated as biosorbents: waste-biomass, a residue derived from the alkaline extraction of a commercial, biostimulant product, and natural-biomass which was harvested, dried and milled as a commercial, “kelp meal” product. Two systems have been evaluated: ideal system with indium only, and double metal-system with indium and iron, where two different levels of iron were investigated. For both systems, the indium biosorption by the brown algal biomass was found to be pH-dependent, with an optimum at pH3. In the ideal system, indium adsorption was higher (maximum adsorptions of 48 mg/g for the processed, waste biomass and 63 mg/g for the natural biomass), than in the double metal-system where the maximum adsorption was with iron at 0.07 g/L. Good values of indium adsorption were demonstrated in both the ideal and double systems: there was competition between the iron and indium ions for the binding sites available in the A. nodosum-derived materials. Data suggested that the processed, waste biomass of the algae, could be a good biosorbent for its indium absorption properties. This had the double advantages of both recovery of indium (high economic importance), and also definition of a virtuous circular economic innovative strategy, whereby a waste becomes a valuable resource.

Chitin and chitosan are biopolymers that have diverse applications in medicine, agriculture, food, cosmetics, pharmaceuticals, wastewater treatment and textiles. With bio-origins, they easily blend with biological systems and show exemplified compatibility which is mandatory when it comes to biomedical research. Chitin and chitosan are ecofriendly, however the processes that are used to recover them aren’t ecofriendly. The focus of this work is to attempt an ecofriendly, sustainable phytomediated one pot recovery of chitosan from commercial chitin and from crab and shrimp shells and squid pen solid wastes. Graviola extracts have been employed, given the fact file that their active ingredients acetogenins actively interact with chitin in insects (resulting in its application as an insecticide). With that as the core idea, the graviola extracts were chosen for orchestrating chitin recovery and a possible chitin to chitosan transformation. The results confirm that graviola extracts did succeed in recovery of chitosan nanofibers from commercial chitin flakes and recovery of chitosan particles directly from solid marine wastes of crab, shrimp and squids. This is a first time report of a phyto-extract mediated novel chitosan synthesis method.

Wastewater treatment plants (WWTPs) in industrial parks provide centralized treatment for industrial and domestic wastewater. However, the information on toxicity reduction of wastewater and its correlation with treatment process in industrial park is limited. This study compared the toxicity reduction of wastewater in 12 industrial park WWTPs based on battery of toxicity assays. Nine toxic endpoints involving microorganism, phytoplankton, zooplankton, plant and human cell lines were applied. All the influents of WWTPs induced high toxicities, which were significantly reduced after the treatments from 7 of the studied WWTPs. However, the effluents of five WWTPs induced higher toxicity in one or more toxic endpoints compared to the influents. This study also found that most of anaerobic-anoxic-oxic (A2/O)-based processes had good removal efficiency of wastewater toxicity, while the sequencing batch reactor (SBR)-based processes had the lowest removal efficiency. Moreover, low correlation coefficients were obtained among all toxic endpoints, indicating that battery of toxicity assays was necessary to completely characterize the toxicity and risk of wastewater in industrial parks. This study shed new lights to the toxicity reduction of wastewater and its correlation with treatment process, which is very useful for the design, management and operation of WWTPs in industrial parks.

As algal biotechnology develops, there is an increasing requirement to conserve cultures without the cost, time and genetic stability implications of conventional serial transfers, including issues regarding potential loss by failure to regrow, contamination on transfer, mix up and/or errors in the documentation on transfer. Furthermore, it is crucial to ensure both viability and functionality are retained by stored stock-cultures. Low temperature storage, ranging from the use of domestic freezers to storage under liquid nitrogen, is widely being used, but the implication to stability and function rarely investigated. We report for the first time, retention of functionality in the maintenance of master stock-cultures of an industrially relevant, lipid-producing alga, under a variety of cryopreservation regimes. Storage in domestic (−15 °C), or conventional −80 °C freezers was suboptimal, with a rapid reduction in viability observed for samples at −15 °C and a >50% loss of viability, within one month, for samples stored at −80 °C. No reduction in viability occurred at −196 °C. Post-thaw culture functional performance was also influenced by the cryopreservation approach employed. Only samples held at −196 °C responded to nitrogen limitation in terms of growth characteristics and biochemical profiles (lipid production and chlorophyll a) comparable to the untreated control, cultured prior to cryopreservation. These results have important implications in microbial biotechnology, especially for those responsible for the conservation of genetic resources.

Carbon nanotubes (CNTs) have been applied in a wide range of fields, such as materials, electronics, energy storages, and biomedicine. With the rapid increase in CNTs industrialization, more and more CNT-containing wastewater is being produced. Since concerns about the toxic effects of CNTs on human health persist, CNT-containing wastewater should not be released into the environment without purification, but no effective methods have been reported. In the present study, we report a simple method to eliminate CNTs from industrial or laboratorial wastewater using sodium hypochlorite. Direct treatment of aqueous dispersions with sodium hypochlorite solution completely degraded CNTs into carbon oxides or carbonates ions. Since hypochlorite is environmentally friendly and frequently used as a disinfectant or bleaching agent in domestic cleaning, this method is practical for purification of CNT-contaminated industrial wastewater.

The large volume of municipal sludge causes environmental problems in cities worldwide. In this study, municipal sludge, mixed with construction waste residue, was used as substrate to plant Ailanthus altissima. The growth of A. altissima, the substrate characteristics, and substrate microbial diversity were measured to investigate potential recycling and reusing pathways of municipal sludge. The obtained results showed that compared to garden soil, the mixed substrate was weakly alkaline, and had higher nutrient contents, which is beneficial for A. altissima, and results in better growth in mixed substrate. Although the contents of the main heavy metals in the mixed substrate were significantly higher than in garden soil, the values met the criterion of Class II soil in the Environmental Quality Standard for the Soils of China (GB15618-1995). Different substrates showed a variety of microbial diversities. Proteobacteria was the top microbial phylum in all samples, and higher relative abundances were found in samples containing municipal sludge. After growing A. altissima, the relative abundances of Acidobacteria and Gemmatimonadetes increased in the mixed substrate. Therefore, addition of construction waste residue and growth of A. altissima caused a difference. The microbial communities in the mixed substrate with A. altissima are both plant friendly and environmentally friendly. These results suggest this mixed substrate as a potentially feasible and effective pathway for the reuse and recycling of municipal sludge for vegetation restoration.

With a conceptual shift in sewage treatment from ‘waste pollution’ to ‘vehicle of resource and energy recovery’ and the further intensification of the energy crisis, the separation and recovery of carbon resources from discharged sewage has gained increasing recent attention in the field of water treatment. The ultra-short Solids Retention Time (SRT) activated sludge process (SRT ≤ 4 d) is highly efficient for separating organic matter and improving the energy recovery rate in wastewater treatment plants, but the effluent quality is relatively poor. If organics in the ultra-short SRT effluent can be reduced further to separate and recover carbon resources, the process may soon replace the traditional activated sludge process. We conducted physical adsorption carbon recovery experiments in an ultra-short SRT (SRT = 2 d) activated sludge system using three carbon nanotubes. Considering that Chemical Oxygen Demand (COD) arises from a mixture of organic compounds, and because humic acid (HA) makes up a large fraction of the effluent and can cause great environmental harm, further experiments were conducted on the adsorption of HA in the effluent COD to three nanotubes. This study proposes a novel method to completely remove organics from the effluent from ultra-short SRT activated sludge processes and reveals nanotube adsorption properties and mechanisms.

Three different treatment technologies, namely mono-algae culture, algal-bacterial culture, and algal-fungal culture, were applied to remove pollutants form synthetic domestic sewage and to remove CO2 from biogas in a photobioreactor. The effects of different initial influent C/N ratios on microalgal growth rates and pollutants removal efficiencies by the three microalgal cultures were investigated. The best biogas upgrading and synthetic domestic sewage pollutants removal effect was achieved in the algal-fungal system at the influent C/N ratio of 5:1. At the influent C/N ratio of 5:1, the algal-fungal system achieved the highest mean chemical oxygen demand (COD) removal efficiency of 81.92% and total phosphorus (TP) removal efficiency of 81.52%, respectively, while the algal-bacterial system demonstrated the highest mean total nitrogen (TN) removal efficiency of 82.28%. The average CH4 concentration in upgraded biogas and the removal efficiencies of COD, TN, and TP were 93.25 ± 3.84% (v/v), 80.23 ± 3.92%, 75.85 ± 6.61%, and 78.41 ± 3.98%, respectively. These results will provide a reference for wastewater purification ad biogas upgrading with microalgae based technology.

Pectin content is an important quality index of fruits, as pectin content undergoes significant changes during the peach ripening process. The commonly used carbazole colorimetry method measures only the total content value of each kind of pectin for each pulp sample and cannot provide distribution maps of the pectin contents for the whole fruit pulp. This work used the hyperspectral imaging technique to quantitatively visualize the distribution maps of pectin contents inside peach pulp at the pixel level. The protopectin contents were well predicted, with the best residual predictive deviation of 2.264, whereas the predictions of the water-soluble pectin and the total pectin contents were not satisfied. On the basis of the best predictive model, the distribution maps of the protopectin contents were quantitatively visualized. A histogram of an example protopectin distribution revealed the existence of a wide range of protopectin contents in peach pulp. Our results show that hyperspectral imaging holds promise as a powerful alternative to the carbazole colorimetry method for measuring the spatial variations in the protopectin distribution inside peach pulp. The distribution maps could be used as a maturity indicator to understand and evaluate the ripening process of peach fruit in depth.

Blue emission giving nanoscale molecular clusters of Oleylamine–Acetone system was formed by an aging assisted hydrogen bond formation between the interacting molecular systems, at room temperature. The as-formed nanoscale molecular clusters were found to be self-assembled into flower-like aggregates and shifted the emission wavelength to red colour depicting an exciton delocalization in the aggregate system. Interestingly aging process has also produced imine type binding between Oleylamine and Acetone due to the condensation reaction. The experimental conditions and formation mechanism of hydrogen bond assisted Oleylamine–Acetone molecular aggregates and imine bond assisted Oleylamine–Acetone is elaborated in this paper in a systematic experimental approach with suitable theory. Finally we have introduced this Acetone assisted aging process in In2S3 QD system prepared with Oleylamine as functional molecules. It was found that the aging process has detached Oleylamine from QD surface and as a consequence In2S3 QD embedded Oleylamine–Acetone aggregates was obtained. When this In2S3 QD embedded molecular cluster system was used as an active layer in a photo conductor device then a maximum photo current value of the order of milli Ampere was obtained. The surfactant molecules normally inhibit the charge transport between QD systems and as a result it is always problematic to have the functional molecules in the QD based transport devices. Our approach has a solution to this problem and the present paper discusses the outcome of the results in detail.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

The applications of machine learning/deep learning (ML/DL) methods in meteorology have developed considerably in recent years. Massive amounts of meteorological data are conducive to improving the training effect and model performance of ML/DL, but the establishment of training datasets is often time consuming, especially in the context of supervised learning. In this paper, to identify the two-dimensional (2D) structures of extratropical cyclones in the Northern Hemisphere, a quasi-supervised reidentification method for extratropical cyclones is proposed. This method first uses a traditional automatic cyclone identification method to construct a trainable labeled dataset and then reidentifies extratropical cyclones in a quasi-supervised fashion by using a (pre-trained) Mask region-based convolutional neural network (Mask R-CNN) model. In comparison, the new method increases the number of identified cyclones by 8.29%, effectively supplementing the traditional method. The newly recognized cyclones are mainly shallow or moderately deep subsynoptic-scale cyclones. However, a considerable portion of the new cyclones along the coastlines of the oceans are accompanied by strong winds. In addition, the Mask R-CNN model also shows good performance in identifying the horizontal structures of tropical cyclones. The quasi-supervised concept proposed in this paper may shed some light on accurate target identification in other research fields.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

In the paper, the results of the first regular studies of ultra-small iron oxide nanoparticles (IONPs) toxicity in vitro were presented. The influence of PEG-coated NPs with 5 nm magnetite core on six different cell lines was examined. These were: human bronchial fibroblasts, human embryonic kidney cells (HEK293T), two glioblastoma multiforme (GBM) cell lines as well as GBM cells isolated from a brain tumor of patient. Additionally, mouse macrophages were included in the study. The influence of IONPs in three different doses (1, 5 and 25 µg Fe/ml) on the viability, proliferation and migration activity of cells was assessed. Moreover, quantifying the intracellular ROS production, we determined the level of oxidative stress in cells exposed to IONPs. In the paper, for the first time, the effect of Fe in the form of IONPs was compared with the analogical data obtained for iron salts solutions containing the same amount of Fe, on the similar oxidation state. Our results clearly showed that the influence of iron on the living cells strongly depends not only on the used cell line, dose and exposure time but also on the form in which this element was administered to the culture. Notably, nanoparticles can stimulate the proliferation of some cell lines, including glioblastoma multiforme. Compared to Fe salts, they have a stronger negative impact on the viability of the cells tested. Ultra-small NPs, also, more often positively affect cell motility which seem to differ them from the NPs with larger core diameters.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

A.P.-F. and J.M.A.: conception and design, statistical analysis, interpretation of data, writing paper. F.J.A.G. and F.M.A.: conducted experiments, analyzed and interpretation of data, feedback on the paper. J.M.G.: feedback on the paper. J.H.M., J.S., and F.B.O.: interpretation of data, feedback on the paper. All authors read and approved the final manuscript., Heart rate variability (HRV) is a valid and non-invasive indicator of cardiac autonomic nervous system functioning. Short-term HRV recordings (e.g., 10 min long) produce data that usually is manually processed. Researcher subjective decision-making on data processing could produce inter- or intraresearcher differences whose magnitude has not been previously quantified in three independent human cohorts. This study examines the inter- and intra-researcher reproducibility of HRV parameters (i.e., the influence of R–R interval selection by different researchers and by the same researcher in different moments on the quantification of HRV parameters, respectively) derived from short-term recordings in a cohort of children with overweight/obesity, young adults and middle-age adults. Participants were recruited from 3 different studies: 107 children (10.03 ± 1.13 years, 58% male), 132 young adults (22.22 ± 2.20 years, 33% males) and 73 middle-aged adults (53.62 ± 5.18 years, 48% males). HRV was measured using a Polar RS800CX heart rate monitor. The intraclass correlation coefficient (ICC) ranged from 0.703 to 0.989 and from 0.950 to 0.998 for inter-and intra-researcher reproducibility, respectively. Limits of agreement for HRV parameters were higher for the interresearcher processing compared with the intra-researcher processing. On average, the intraresearcher differences were 31%, 62%, and 80% smaller than the inter-researchers differences based on Coefficient of Variation in children, young and middle-aged adults, respectively. Our study provides the quantification of the inter-researcher and intra-researcher differences in three independent human cohorts, which could elicit some clinical relevant differences for HRV parameters. Based on our findings, we recommend the HRV data signal processing to be performed always by the same trained researcher and we postulate a development of algorithms for an automatic ECG selection., Spanish Ministry of Economy and Competitiveness DEP2013-47540 DEP2016-79512-R PTA 12264-I, Spanish Ministry of Education, Culture and Sport FPU 16/02760 FPU15/02645 FPU15/04059 FPU14/06837 FPU14/04172, Unit of Excellence on Exercise and Health (UCEES), EXERNET Research Network on Exercise and Health in Special Populations DEP2005-00046/ACTI, Unit of Excellence in Sport and Health (UCEES) - University of Granada, Junta de Andalucía, European Union (EU) SOMM17/6107/UGR

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

E-mail has become the main carrier of spreading malicious software and been widely used for phishing, even high-level persistent threats. The e-mail accounts with high social reputation are primary targets to be attacked and utilized by attackers, suffering a lot of probing attacks for a long time. In this paper, in order to understand the probing pattern of the e-mail account attacks, we analyse the log of email account probing captured in the campus network based on graph mining. By analysing characteristics of the dataset in different dimensions, we find a kind of e-mail account probing attack and give it a new definition. Based on the analysis results, its probing pattern is figured out. From the point of probing groups and individuals, we find definitely opposite characteristics of the attack. Owing to the probing pattern and its characteristics, attacks can escape from the detection of security devices, which has a harmful effect on e-mail users and administrators. The analysis results of this paper provide support for the detection and defence of such distributed attacks.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Spiking neural networks (SNNs) are considered as the third generation of artificial neural networks, having the potential to improve the energy efficiency of conventional computing systems. Although the firing rate of a spiking neuron is an approximation of rectified linear unit (ReLU) activation in an analog-valued neural network (ANN), there remain many challenges to be overcome owing to differences in operation between ANNs and SNNs. Unlike actual biological and biophysical processes, various hardware implementations of neurons and SNNs do not allow the membrane potential to fall below the resting potential—in other words, neurons must allow the sub-resting membrane potential. Because there occur an excitatory post-synaptic potential (EPSP) as well as an inhibitory post-synaptic potential (IPSP), negatively valued synaptic weights in SNNs induce the sub-resting membrane potential at some time point. If a membrane is not allowed to hold the sub-resting potential, errors will accumulate over time, resulting in inaccurate inference operations. This phenomenon is not observed in ANNs given their use of only spatial synaptic integration, but it can cause serious performance degradation in SNNs. In this paper, we demonstrate the impact of the sub-resting membrane potential on accurate inference operations in SNNs. Moreover, several important considerations for a hardware SNN that can maintain the sub-resting membrane potential are discussed. All of the results in this paper indicate that it is essential for neurons to allow the sub-resting membrane potential in order to realize high-performance SNNs.

Emergent trends in the device development for neural prosthetics have focused on establishing stimulus localization, improving longevity through immune compatibility, reducing energy re-quirements, and embedding active control in the devices. Ultrasound stimulation can single-handedly address several of these challenges. Ultrasonic stimulus of neurons has been studied extensively from 100 kHz to 10 MHz, with high penetration but less localization. In this paper, a chip-scale device consisting of piezoelectric Aluminum Nitride ultrasonic transducers was engineered to deliver gigahertz (GHz) ultrasonic stimulus to the human neural cells. These devices provide a path towards complementary metal oxide semiconductor (CMOS) integration towards fully controllable neural devices. At GHz frequencies, ultrasonic wavelengths in water are a few microns and have an absorption depth of 10–20 µm. This confinement of energy can be used to control stimulation volume within a single neuron. This paper is the first proof-of-concept study to demonstrate that GHz ultrasound can stimulate neurons in vitro. By utilizing optical calcium imaging, which records calcium ion flux indicating occurrence of an action potential, this paper demonstrates that an application of a nontoxic dosage of GHz ultrasonic waves $$(\ge 0.05\frac{W}{c{m}^{2}})$$ ( ≥ 0.05 W c m 2 ) caused an average normalized fluorescence intensity recordings >1.40 for the calcium transients. Electrical effects due to chip-scale ultrasound delivery was discounted as the sole mechanism in stimulation, with effects tested at α = 0.01 statistical significance amongst all intensities and con-trol groups. Ionic transients recorded optically were confirmed to be mediated by ion channels and experimental data suggests an insignificant thermal contributions to stimulation, with a predicted increase of 0.03 oC for $$1.2\frac{W}{c{m}^{2}}\cdot $$ 1.2 W c m 2 ⋅ This paper paves the experimental framework to further explore chip-scale axon and neuron specific neural stimulation, with future applications in neural prosthetics, chip scale neural engineering, and extensions to different tissue and cell types.

The lack of biomarkers for an early diagnosis of neurodegenerative disorders (NDs) has hampered the development of therapeutics whose effect would be enhanced by a timely intervention. Neurofilaments light chain (Nf-L), an integral part of the axonal structure, has emerged as a robust fluid biomarker for fatal neurodegenerative disorders like amyotrophic lateral sclerosis (ALS). To facilitate large-scale studies into early-stage neurodegeneration, reduce costs of samples collection/processing and cold-chain storage, we describe the measurement of Nf-L in blood fractions obtained from dry blood spots (DBS) and dry plasma spots (DPS), two filter paper-based remote blood collection tools. To test the feasibility of using this approach, Nf-L analysis in DBS/DPS is compared to that in plasma obtained from the same blood sample, looking at Nf-L discriminatory power in the clinical stratification of ALS compared to healthy controls. With the best pre-analytical treatment for total protein recovery and using highly sensitive immunoassays, we report the detection of different Nf-L levels in DBS elute compared to reference plasma and DPS from the same blood samples. However, Nf-L measurement in DBS elutes provides a very good discrimination of ALS from healthy controls which is comparable to that obtained using plasma Nf-L assays. With the available immunodetection methods, we show that Nf-L measurement based on DPS microsampling is similar to that in plasma. The filter-paper biophysical characteristics and the interference of high haemoglobin concentration released by erythrocyte lysis is likely to perturb Nf-L detection in DBS elute. Further studies into DBS-based Nf-L detection and its analytical optimization are needed to make this method suitable for routine Nf-L blood analyses in neurodegeneration.

“Alteration” geologically refers to chemical composition and/or structural changes of minerals under the influences of hydrothermal fluids, surface water, seawater, or other environmental conditions. In this paper, we use the word “alteration” to refer to chemical component and structural changes in jade artifacts caused by human activity and natural weathering, which is different from the term in geology. “Mercury alteration”, a kind of black alteration related to Hg, is unique among the several types of alteration that occur in Chinese ancient jades. Mercury alteration often appears on ancient jade artifacts unearthed from high-grade tombs of the pre-Qin period (before 221 B.C.). Therefore, ancient jades with mercury alteration have attracted substantial attention from Chinese archaeologists. This paper reports the use of materials analytic techniques to study such ancient jade fragments. The studied jade samples date to the middle and late periods of the Spring and Autumn Period (~500 B.C.) and were unearthed from Lizhou’ao Tomb in Jiangxi Province, China. Structural analyses revealed the internal microstructure of the ancient jade fragments and the microdistribution of the mercury alteration. The jade fragments exhibit typical characteristics of round holes and structural hierarchy, which imply that the jades were heated before burial. The black alteration on these jade samples was found to be rich in Hg. The results of this study will be widely useful in the study of ancient jade artifacts and jade culture in Chinese archeology.

This paper establishes a Markov chain model as a unified framework for describing the evolution processes in complex networks. The unique feature of the proposed model is its capability in addressing the formation mechanism that can reflect the "trichotomy" observed in degree distributions, based on which closed-form solutions can be derived. Important special cases of the proposed unified framework are those classical models, including Poisson, Exponential, Power-law distributed networks. Both simulation and experimental results demonstrate a good match of the proposed model with real datasets, showing its superiority over the classical models. Implications of the model to various applications including citation analysis, online social networks, and vehicular networks design, are also discussed in the paper.

Marine plastic pollution is an increasing environmental threat. Although it is assumed that most marine plastics are transported from land to the ocean through rivers, only limited data on riverine plastic transport exists. Recently, new methods have been introduced to characterize riverine plastics consistently through time and space. For example, combining visual counting observations and plastic debris sampling can provide order of magnitude estimations of plastic transport through a river. In this paper, we present findings from multi-season measurement campaign in the Saigon River, Vietnam. For the first time, we demonstrate that macroplastic transport exhibits strong temporal variation. The monthly averaged plastic transport changes up to a factor five within the measurement period. As it is unclear what drives the variation in plastic transport, relations between rainfall, river discharge, presence of organic material and plastic transport have been explored. Furthermore, we present new findings on the cross-sectional and vertical distribution of riverine plastic transport. With this paper we present new insights in the origin and fate of riverine plastic transport, emphasizing the severity of the emerging thread of plastic pollution on riverine ecosystems.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Due to increasing global warming resulting from the greenhouse effect, subsequent environmental impacts and corresponding ecological influences are unavoidable. These problems are becoming more serious with time. Due to rising temperatures, the survival crisis of polar bears is a very often reported issue, because polar bears are encountering shortened seasons for catching prey on their sea-ice habitat. In this work, we report an innovative and facile strategy to save polar bears via prolonging the existence of ice layers based on plasmon-activated water (PAW). PAW with a reduced hydrogen-bonded network can be created by letting bulk deionized (DI) water flow through supported gold nanoparticles (AuNPs) under resonant illumination. Experimental results indicated that the freezing time of PAW was faster than that of DI water. In contrast, the melting time of frozen PAW was slower than that of the frozen DI water. Because the PAW with reduced hydrogen bonds (HBs) is in a high-energy state, it can more easily transform into a stronger HB structure in a low-energy state during cooling when freezing. This is accompanied by the release of more available energy, resulting in more-perfect tetrahedral symmetrical ice. Similar results were observed for solutions with 3 wt% NaCl, which is similar to the salinity of sea water. Moreover, the heat required to melt frozen PAW was ca. 7.6% higher than that of frozen DI water. These interesting phenomena suggest that prolonging the existence of solid ice can be achieved in a PAW-based system. Moreover, a system of AuNP-coated filter paper in DI water or in a DI water solution (3 wt% NaCl) under resonant illumination could work to prolong the presence of solid ice, compared to a system of AuNP-free filter paper. This innovative concept has emerged as a practical strategy to save polar bears and for other related applications.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

We have proposed a dynamic smoothing method based on a phase control to smooth plasma non-uniformities in perturbed plasma systems. In this paper, the dynamic smoothing method is applied to a spherical direct-driven fuel target implosion in heavy ion inertial confinement fusion. We found that the wobbling motion of each heavy ion beam (HIB) axis induces a phase-controlled HIBs energy deposition, and consequently the phase-controlled implosion acceleration is realized, so that the HIBs irradiation non-uniformity is successfully smoothed. HIB accelerators provide a well-established performance to oscillate a HIB axis at a high frequency. In inertial confinement fusion, a fuel implosion uniformity is essentially significant for achieving the DT fuel compression and for releasing the fusion energy, and the non-uniformity of the implosion acceleration should be less than a few %. The results in this paper demonstrate that the wobbling HIBs would provide an improvement in the fuel target implosion uniformity.