Underwater adhesion is crucial to many marine life forms living a sedentary lifestyle. Amongst them, mussel adhesion has been mostly studied, which inspires numerous investigations of ...3,4-dihydroxyphenylalanine (DOPA)-based organic adhesives. In contrast, reef-building oysters represent another important “inorganic” strategy of marine molluscs for adhesion by generating biomineralized organic–inorganic adhesives, which is still rarely studied and no synthetic analogues have ever been reported so far. Here, a novel type of oyster-inspired organic–inorganic adhesive based on a biomineralized polyelectrolyte hydrogel is reported, which consists of polyacrylic acid physically cross-linked by very small amorphous calcium carbonate nanoparticles (<3 nm). The mineral-enhanced polyelectrolyte hydrogel adhesive is shown to be injectable, reusable, and optically clear upon curing in air. Moreover, comparable adhesion performance to DOPA-based adhesives is found for the hydrogel adhesive in both dry and wet conditions, which can even be further enhanced by introducing a small amount of second large cross-linker such as negatively charged nanoparticles. The present mineral hydrogel represents a new type of bio-inspired organic–inorganic adhesive that may find a variety of potential applications in adhesive chemistry.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been spreading worldwide, causing a global pandemic. Bat-origin RaTG13 is currently the most phylogenetically related virus. Here we ...obtained the complex structure of the RaTG13 receptor binding domain (RBD) with human ACE2 (hACE2) and evaluated binding of RaTG13 RBD to 24 additional ACE2 orthologs. By substituting residues in the RaTG13 RBD with their counterparts in the SARS-CoV-2 RBD, we found that residue 501, the major position found in variants of concern (VOCs) 501Y.V1/V2/V3, plays a key role in determining the potential host range of RaTG13. We also found that SARS-CoV-2 could induce strong cross-reactive antibodies to RaTG13 and identified a SARS-CoV-2 monoclonal antibody (mAb), CB6, that could cross-neutralize RaTG13 pseudovirus. These results elucidate the receptor binding and host adaption mechanisms of RaTG13 and emphasize the importance of continuous surveillance of coronaviruses (CoVs) carried by animal reservoirs to prevent another spillover of CoVs.
Display omitted
•The complex structure of RaTG13 RBD with hACE2 was determined•Binding of RaTG13 RBD to 24 additional ACE2 orthologs was evaluated•Residue 501 plays a key role in determining the potential host range of RaTG13•SARS-CoV-2 induces strong cross-protective antibodies to RaTG13 RBD
Structural and molecular analysis of the receptor binding domain of RaTG13, a coronavirus phylogenetically closely related to SARS-CoV-2, bound to the human receptor ACE2 as well as ACE2 orthologs in 24 other species provides a framework to understand its host range as well as the basis of antibody cross-reactivity between the two viruses.
SARS-CoV-2 Omicron variant has presented significant challenges to current antibodies and vaccines. Herein, we systematically compared the efficacy of 50 human monoclonal antibodies (mAbs), covering ...the seven identified epitope classes of the SARS-CoV-2 RBD, against Omicron sub-variants BA.1, BA.1.1, BA.2, and BA.3. Binding and pseudovirus-based neutralizing assays revealed that 37 of the 50 mAbs lost neutralizing activities, whereas the others displayed variably decreased activities against the four Omicron sub-variants. BA.2 was found to be more sensitive to RBD-5 antibodies than the other sub-variants. Furthermore, a quaternary complex structure of BA.1 RBD with three mAbs showing different neutralizing potencies against Omicron provided a basis for understanding the immune evasion of Omicron sub-variants and revealed the lack of G446S mutation accounting for the sensitivity of BA.2 to RBD-5 mAbs. Our results may guide the application of the available mAbs and facilitate the development of universal therapeutic antibodies and vaccines against COVID-19.
Display omitted
•Immune escape of 50 human mAbs by Omicron sub-variants was assessed•Omicron sub-variants BA.1, BA.1.1, BA.2, and BA.3 have similar immune evasion spectra•BA.2 is more sensitive to RDB-5 mAbs due to the lack of G446S mutation
The evolution of SARS-CoV-2 variants of concern brings new challenges toward host immunity and protection. Huang et al. tested the neutralization potency of 50 human mAbs against Omicron sub-variants BA.1, BA.1.1, BA.2, and BA.3. Structural analysis of three mAbs provides further insight into the immune evasion capacity of Omicron sub-variants.
Polycyclic aromatic hydrocarbons (PAHs) have been demonstrated to be neurotoxic.
To summarize the existing epidemiological studies to quantify the effects of PAHs exposure on child neurodevelopment ...and adult emotional disorders.
We conducted a systematic literature search for studies of child neurodevelopment and adult emotional disorders published in English up to April 2022 in the databases of PubMed, Web of Science and Embase using combinations of MeSH terms and Entry terms, and the articles were filtered out according to data availability. A variety of common PAHs were included in the meta-analysis: 1-hydroxynaphthalene, 2-hydroxynaphthalene, 2-hydroxyfluorene, 3-hydroxyfluorene, 9-hydroxyfluorene, 1-hydroxyphenanthrene, 2-hydroxyphenanthrene, 3-hydroxyphenanthrene, 4-hydroxyphenanthrene, 9-hydroxyphenanthrene, 1-hydroxypyrene and benzoapyrene (BaP).
We extracted the content of each article, summarized its design characteristics and performed quality evaluation. We combined the odds ratio (OR) available in various studies to obtain the risk of PAHs exposure and adaptive, language, social, attention, motor skills and child depression/anxiety in children ≤ 15 years old. In addition, we also conducted a meta-analysis on the relationship between PAHs exposure and the risk of depression in adults.
We included a total of 16 epidemiological studies (4 cross-sectional studies and 12 cohort studies). The sample size of all included studies ranged from 110 to 9625. Prenatal exposure to PAHs was found to be associated with increased risk of social behavior (OR = 1.60, 95% CI: 1.00–2.54), attention (OR = 2.99, 95% CI: 1.48–6.02), motor skill problems (OR = 1.91, 95% CI: 1.27–2.86) and any adverse neurodevelopmental outcome in children (OR = 2.10, 95% CI: 1.69–2.62). In addition, we found that PAHs exposure could increase the risk of adult depression, with 2-hydroxyfluorene exposure showing the highest combined OR (OR = 1.48, 95% CI: 1.10–2.00).
The results suggested that PAHs exposure are associated with increased risk of child neurodevelopment and adult depression. The neurotoxic effects of PAHs exposure in human being should be paid more attention. The results suggested that PAHs exposure are associated with increased risk of child neurodevelopment and adult depression. The neurotoxic effects of PAHs exposure in human being should be paid more attention. Steps should be taken to enhance the biomonitoring of PAHs and to reduce the exposure in general population.
•PAHs are environmental pollutants and are widely present.•Prenatal exposure to PAHs is detrimental to the neurodevelopment of offspring.•Exposure to PAHs may increase the risk of mood disorders in adults.
With its its ability to non-contact measure three-dimensional information of objects and its extremely high accuracy advantage in close range, structured light 3-D measurement is widely used in ...various fields. However, some application scenarios, such as measuring moving objects and performing measurements in confined spaces, impose requirements for high speed and miniaturization in structured light 3-D measurement. Therefore, we propose a real-time structured light 3-D measurement system on FPGA. This system employs a four-step phase-shifting method to compute wrapped phases, complemented Gray code for phase unwrapping, and a cubic polynomial fitting approach for calculating the 3-D coordinates of points. We have proposed the optimized pipeline structure for each module. We have also proposed an optimized on-chip buffer structure to further improve throughput. The 3-D measurement speed of the proposed method can reach 76.9 fps, when the clock frequency is 100 MHz, and the image size is 2448
×
2048.
Replacing natural gas with the environmentally sustainable biogas is a promising way to reduce the usage of fossil fuels and promote organic waste utilization. Micro gas turbine (MGT), as a common ...power supply machine, is capable of adopting biogas as the fuel. Given the different intrinsic components between natural gas and biogas, combustion performance of biogas in MGT was studied in this work. The effects of fuel composition and excess air coefficient on combustion performance were analyzed through three-dimensional numerical simulation of the MGT combustor. RNG
k
-
ε
turbulent model, eddy-dissipation/finite rate model, and eight-step reaction mechanism were adopted in the simulation. The results showed that when the CO
2
percentage in biogas increases, the NO and CO emissions decreases. However, the fuel rate and pressure drop of combustion chamber increases to maintain constant thermal input. The overall high velocity also increases the requirement for materials of combustion chamber. Furthermore, the average temperature of whole combustor decreases when the excess air coefficient increases. Accordingly, the CO
2
mole fraction in biogas should be controlled below 30% and the optimal range of the excess air coefficient is 2–2.5 for the MGT.
The pig industry is the pillar industry of animal husbandry in China, and epidemics can lead to drastic changes in pig supply, affecting the healthy development of the pig industry and residents’ ...quality of life. This study analyzed the mechanism of the effect of swine epidemics on nonlinear shocks to pig supply, and monthly data on pig supply from January 2012 to June 2020 were applied to study the threshold effect of swine epidemics on pig stock and slaughter in China empirically, using the index of swine epidemics’ width (ISEW) as the threshold variable. The results of this study were as follows: (1) The influence of the ISEW over 7 months on pig stock in China was divided into two ranges, and the pig stock did not change significantly when the ISEW was less than 0.25. Swine epidemics had a significantly negative impact on the pig stock when the ISEW was larger than 0.25. (2) The influence of the ISEW over 8 months on pig slaughter was also divided into two ranges. When the ISEW was less than 0.33, epidemics had a positive and significant effect on pig slaughter, while epidemics had a marked negative impact on pig slaughter when the ISEW was greater than 0.33. Based on these conclusions, this study proposed relevant measures for the prevention and control of swine epidemics.
The strain-controlled cyclic deformation behaviour of Mg-9Gd-4Y-2Zn-0.5Zr with different structures was investigated. Alloys were prepared by solution, extrusion and pre-ageing extrusion, and the ...microstructures before and after the fatigue tests were characterized. Experimental results indicated that the bimodal structure owned the better performance in fatigue test, which was attributed to the higher yield strength. For the equiaxed structure, cyclic hardening induced stress concentration until the failure. Stable cyclic deformation and persistent cyclic softening played an important role at the low and high strain amplitudes, respectively. This was attributed to the formation of fine grains relieving the stress concentration during cyclic loading. In addition, residual twins were observed in equiaxed structure to induce crack, and the bimodal structure effectively restrain it.
The development of skin-compatible polyurethane materials with excellent wide-temperature range and anti-aging self-healing properties is considered crucial for modern applications. However, few ...polyurethane materials can achieve these characteristics simultaneously because of the chemical bond activity. Here, we report a wide-temperature range and anti-aging self-healing polyurethane material with superior mechanical features. At -40 °C, the polyurethane exhibits a self-healing efficiency of 12.6%, with a tensile strength of ~1.4 MPa and elongation at break of ~1424.5%. At 60 °C, its self-healing efficiency reached 93.6%, with an elongation at break of 1922.2% without significant reduction of the tensile strength. Notably, its low-temperature self-healing efficiency was 19.3 and 12.6%, respectively, at -20 and-40 °C, and the samples showed some degree of self-healing, even at -60 and -80 °C. Meanwhile, the polyurethane showed excellent anti-aging performance, and its self-healing properties were sufficiently high after aging at 60 °C for 1 days. The designed polyurethane is expected to offer a promising platform for fabricating materials for electronic skin applications, wearable electronic devices, flexible displays, and soft robotics.
The detection of partial discharge (PD) in transformers is of great significance for preventing insulation defects from developing into insulation failures. Transformer partial discharge detection ...technology includes pulse current method, radio frequency measurement method, UHF method, ultrasonic detection method, gas chromatography, and optical detection method. Among them, the optical detection method has the characteristics of strong anti-electromagnetic interference ability, and the signal can be transmitted and received without loss. The optical detection method has unique advantages. In this paper, an optical signal measuring device for partial discharge inside the transformer is designed and fabricated, the typical insulation defect inside the transformer is simulated, and the optical signal characteristics of typical partial discharge are obtained. Compared with the pulse current method, it is found that the magnitude of partial discharge can be characterized by the integral of the optical signal. The characteristic of the optical signal phase resolved partial discharge (PRPD) spectrum of typical insulation defects is obtained. The PRPD spectrum of the optical signals of different defects is obviously different. It is feasible to draw the PRPD spectrum and identify the defect types according to the optical signal, which can be further applied to the identification of internal faults in transformers.
PDF
