Research progress in the removal of fluoride ions from mine water by adsorption method

Fluoride ions are widely distributed in surface rivers and groundwater bodies in China, especially in the mining areas along the Yellow River in the western Yellow River basin that there is a widespread problem of excessive fluoride in the mine water, which poses a potential threat to the local ecological environment and human health. The status quo of fluoride pollution in China is mostly at a low concentration pollution level, which leads to it difficult to remove efficiently through conventional water treatment technologies. The adsorption method is considered to be an effective way to remove low concentration fluoride ions because of its high adsorption efficiency and convenient operation. The research status of fluoride removal by commonly used adsorption materials such as carbon based, minerals, metals and metal organic frameworks (MOFs) was reviewed and summarized before summarizing the influence of different factors on the fluoride removal efficiency and adsorption mechanism of these adsorption materials. Then the application effect and operation cost of adsorption method in mine water treatment were emphatically analyzed, and the development direction of adsorption method in the treatment of low concentration (<10 mg/L) and high water content fluorine-containing mine water was prospected. In general, there are still some deficiencies in the study of fluoride removal by adsorption. In terms of adsorption mechanism, it should be further investigated from three aspects which includes the characteristics of adsorption materials, the occurrence form of fluoride ions and the interaction mechanism between adsorption materials and fluoride ions. For the engineering application of adsorption method, the demand of engineering application should be regarded as the guidance. Based on the above discussion, the research and development direction of removing fluoride ions from mine water by adsorption method is proposed, which is to focus on the development of low cost and high efficiency environment-friendly modified adsorbents based on natural/waste (ore) and carbon-based, aluminum-based or other new polymer adsorption materials under the principle of clarifying local policies and water quality and quantity. In addition, it is necessary not to improve the selective adsorption performance of the modified adsorbent for fluoride ions, but also to ensure the stability, economy and safety of the adsorbent in the whole life cycle of preparation, processing, production and recycling, thereby improving its competitiveness of the adsorption method in the actual application of fluoride containing wastewater and enhancing the application potential of the adsorption method

Using machine learning to explore the characteristics of eye movement patterns and relationship with cognition ability of Chinese children aged 1–6 years

Researchers have begun to investigate the relationship between eye movement characteristics of gaze patterns and cognitive abilities, and have attempted to use eye-tracking technology as a new method to evaluate cognitive abilities. Traditional eye movement analysis methods typically separate spatial and temporal information of eye movements, mostly analyze averaged data, and consider individual differences as noise. In addition, current eye movement studies on gaze patterns mostly involve adults, while research on infants and toddlers is limited with small sample sizes and narrow age ranges. It is still unknown whether the conclusions drawn from adult-based research can be applied to children. Consequently, eye movement research on gaze patterns in children is necessary. To address the concerns stated above, this study used the Hidden Markov machine learning method to model gaze patterns of 330 children aged 1–6 years while observing faces freely, and analyzed characteristics of eye movement gaze patterns. Additionally, we analyzed the correlation between gaze patterns of 31 toddlers aged 1–3 years and 37 preschoolers aged 4–6 years, and the different dimensions of cognitive abilities. The findings indicated that children exhibited holistic and analytic gaze patterns while observing different faces freely. More children adopted a holistic gaze pattern, and there were age-specific gaze pattern characteristics and regularities. Gaze patterns of toddlers may be correlated with their adaptive abilities and gaze patterns of preschoolers may be correlated with their visual space abilities. Specifically, toddlers aged 1–3 years showed a moderate negative correlation between the H-A scale and the adaptive dimension, while preschoolers aged 4–6 years showed a low negative correlation between the H-A scale and the visual space dimension. This study may provide new insights into the characteristics of children’s eye-movement gaze patterns during face observation, and potentially offer objective evidence for future research aimed at promoting the use of eye-tracking technology in the assessment of toddlers’ adaptive abilities and preschoolers’ visual space abilities in the field of face perception

PREDICTION OF LOAD LIMIT OF BI-MODULUS COMPOSITES LAMINATED STRUCTURE

Based on three dimensional continuum damage mechanics,an improved progressive damage analysis method was proposed for bi-modulus fiber-reinforced polymer（ BFRP） composites laminated structure. Firstly,according to the bi-linear model of bi-modulus materials and constitutive theory of orthotropic material,the stress-strain relation for BFRP composites lamina was described. Secondly,in-situ strength of lamina was calculated using Dvorak model. Plus,damage initiation and its evolution inside laminates were described by three-dimensional Hashin strength criterion and the exponential damage evolution criterion,and the cohesive element was used to describe the interlaminar mechanical behavior. Then,the progressive damage analysis code for BFRP composites laminated structure was realized through ABAQUS material subroutine UMAT. The new method was verified by comparing to the experimental results in literatures. Finally,this method is used to examine the load limit of a BFRP arm structure which is a part of space station and obtain the prediction results

Research on indoor thermal environment evaluation and thermal adaptation in winter of Japanese wood-framed detached houses

Indoor space is the place where human beings live, and how to meet people's indoor thermal comfort needs in the context of energy scarcity is one of the important issues for sustainable development of buildings, and the evaluation of the indoor thermal environment has become the key to it. In the case of Japanese wood-framed detached houses, which contain different types of space forms, it is difficult to accurately apply the existing thermal environment evaluation results. In this study, detached houses in Kitakyushu City, Japan, were selected as the research object, and continuous measurements and subjective questionnaires of the indoor thermal environments were conducted based on three modes of no heating, continuous heating, and intermittent heating, in order to grasp the current information of the thermal comfort in detached houses. The results showed that: 1. The average indoor temperatures in both Washitsu and Yoshitsu were lower than the human thermal comfort range; 2. The thermally neutral temperature of 15.9 °C in Washitsu was lower than that of 17.7 °C in Yoshitsu, and the acceptable temperature zones were (14.3–17.5 °C) and (15.6–18.9 °C), respectively; 3. Develop modified models (PMVe) and adaptive predicted mean vote (aPMV) model suitable for thermal comfort evaluation of detached houses in Japan. The results of this study will help to improve the indoor thermal environment and thermal comfort evaluation system of Japanese detached houses, and provide a useful reference for the study of the renewal and renovation of houses in this area

Preparation of Conductive Cellulose Coated with Conductive Polymer and Its Application in the Detection of pH and Characteristic Substances in Sweat

Rich biological information in sweat provides great potential for health monitoring and management. However, due to the complexity of sweat, the development of environmentally friendly green electronic products is of great significance to the construction of ecological civilization. This study utilized a simple combination of polystyrene sulfonate sodium (PSS) and filter paper (FP) to prepare cellulose materials coated with conductive polymers, developing an electrochemical sensor based on the modified materials. The mechanical and electrochemical properties of the fabricated PSS/FP membrane were optimized by adjusting the feeding dosage of PSS. The realized PSS/FP composite containing 7% PSS displayed good conductivity (9.1 × 10−2 S/m), reducing electric resistance by 99.2% compared with the original FP membrane (6.7 × 10−4 S/m). The stable current of the membrane in simulated sweat under different pH environments is highly correlated with the pH values. Additionally, when the membrane is exposed to simulated sweat with varying ion concentrations, the current signal changes in real time with the concentration variations. The response time averages around 0.3 s

Mesenchymal Migration on Adhesive–Nonadhesive Alternate Surfaces in Macrophages

Abstract Mesenchymal migration usually happens on adhesive substrates, while cells adopt amoeboid migration on low/nonadhesive surfaces. Protein‐repelling reagents, e.g., poly(ethylene) glycol (PEG), are routinely employed to resist cell adhering and migrating. Contrary to these perceptions, this work discovers a unique locomotion of macrophages on adhesive–nonadhesive alternate substrates in vitro that they can overcome nonadhesive PEG gaps to reach adhesive regions in the mesenchymal mode. Adhering to extracellular matrix regions is a prerequisite for macrophages to perform further locomotion on the PEG regions. Podosomes are found highly enriched on the PEG region in macrophages and support their migration across the nonadhesive regions. Increasing podosome density through myosin IIA inhibition facilitates cell motility on adhesive–nonadhesive alternate substrates. Moreover, a developed cellular Potts model reproduces this mesenchymal migration. These findings together uncover a new migratory behavior on adhesive–nonadhesive alternate substrates in macrophages

Application of Multicolor Fluorescent Carbon Dots Based on Tea Polyphenols in a White Light-Emitting Diode and Room-Temperature Phosphorescence

Carbon dots (CDs) are new carbon nanomaterials, among which those prepared from biomass are popular due to their excellent optical properties and environmental friendliness. As representative natural phenolic compounds, tea polyphenols are ideal precursors with fluorescent aromatic rings and phenolic hydroxyl structures. Usually, polyphenolic precursors can only be used to produce blue or green fluorescent CDs, and fluorescence in long wavelength domains, such as orange or red, cannot be achieved. Herein, the high reactivity of the phenolic hydroxyl groups in tea polyphenols with o-phthalaldehyde was exploited to modulate the pH during the carbonation process, which led to redshifts of the fluorescence wavelengths. Different pH values during the reaction caused the precursors to take different reaction paths and form fluorescent groups exhibiting different conjugated structures, resulting in carbon dots providing different fluorescent colors. Finally, by utilizing the in situ hydrolysis of ethyl orthosilicate, the tea polyphenol-based carbon dots were embedded into a silica matrix, inducing phosphorescence of the carbon dots. This study provides a new approach for green preparation and application of natural polyphenolic CDs

Systematic analyses of the factors influencing sperm quality in patients with SARS-CoV-2 infection

Abstract To figure out how does SARS-CoV-2 affect sperm parameters and what influencing factors affect the recovery of sperm quality after infection? We conducted a prospective cohort study and initially included 122 men with SARS-CoV-2 infection. The longest time to track semen quality after infection is 112 days and 58 eligible patients were included in our study eventually. We subsequently exploited a linear mixed-effects model to statistically analyze their semen parameters at different time points before and after SARS-CoV-2 infection. Semen parameters were significantly reduced after SARS-CoV-2 infection, including total sperm count (211 [147; 347] to 167 [65.0; 258], P < 0.001), sperm concentration (69.0 [38.8; 97.0] to 51.0 [25.5; 71.5], P < 0.001), total sperm motility (57.5 [52.3; 65.0] to 51.0 [38.5; 56.8], P < 0.001), progressive motility (50.0 [46.2; 58.0] to 45.0 [31.5; 52.8], P < 0.001). The parameters displayed the greatest diminution within 30 days after SARS-CoV-2 infection, gradually recovered thereafter, and exhibited no significant difference after 90 days compared with prior to COVID-19 infection. In addition, the patients in the group with a low-grade fever showed a declining tendency in semen parameters, but not to a significant degree, whereas those men with a moderate or high fever produced a significant drop in the same parameters. Semen parameters were significantly reduced after SARS-CoV-2 infection, and fever severity during SARS-CoV-2 infection may constitute the main influencing factor in reducing semen parameters in patients after recovery, but the effect is reversible and the semen parameters gradually return to normal with the realization of a new spermatogenic cycle

Selective Antimicrobial Activities and Action Mechanism of Micelles Self-Assembled by Cationic Oligomeric Surfactants

This work reports that cationic micelles formed by cationic trimeric, tetrameric, and hexameric surfactants bearing amide moieties in spacers can efficiently kill Gram-negative E. coli with a very low minimum inhibitory concentration (1.70–0.93 μM), and do not cause obvious toxicity to mammalian cells at the concentrations used. With the increase of the oligomerization degree, the antibacterial activity of the oligomeric surfactants increases, i.e., hexameric surfactant > tetrameric surfactant > trimeric surfactant. Isothermal titration microcalorimetry, scanning electron microscopy, and zeta potential results reveal that the cationic micelles interact with the cell membrane of E. coli through two processes. First, the integrity of outer membrane of E. coli is disrupted by the electrostatic interaction of the cationic ammonium groups of the surfactants with anionic groups of E. coli, resulting in loss of the barrier function of the outer membrane. The inner membrane then is disintegrated by the hydrophobic interaction of the surfactant hydrocarbon chains with the hydrophobic domains of the inner membrane, leading to the cytoplast leakage. The formation of micelles of these cationic oligomeric surfactants at very low concentration enables more efficient interaction with bacterial cell membrane, which endows the oligomeric surfactants with high antibacterial activity