A synergistic reactive flame‐retardant polyol (AFeDH) containing ferrocene, phosphorus, and nitrogen elements was synthesized from ferro‐formaldehyde, 5‐amino‐1,3, 4‐thiadiazole‐2‐mercaptan, ...9,10‐dihydro‐9‐oxa‐10‐phos‐phaphenanthrene‐10‐oxide and hydroxyl terminated polybutadiene acrylonitrile, and then applied for flame retarding waterborne polyurethane (WPU). The chemical structures of intermediates and final products were well characterized to confirm the successful preparation of ternary P‐N‐Fe flame retardant. The effects of incorporated AFeDH on thermal stability, flame retardancy and mechanical properties of AFeDH/WPU films were systematically studied. The results indicated that LOI value increased with the increase amount of AFeDH, while the value then decreased as the loading content above 6 wt%. This increase in flame retardancy results from the competition between the catalytic degradation of iron and the catalytic carbonization. Benefiting from the good synergistic effects among each element of AFeDH, the WPU/AFeDH films perform the decreased heat release and smoke production. Moreover, the flame retardant films also show the enhanced tensile strength of 33.8 MPa and elongation at break of 763.3%. Therefore, this novel halogen‐free flame retardant shows an excellent synergistic effect among P, N, and Fe elements, which has a great potential in the application of flame retardant WPU.
The synergistic flame retardant of ferrocene, phosphorus and nitrogen can effectively restrain the production of smoke and heat release at high temperature. It can effectively catalyze carbonization to form graphitized surface on waterborne polyurethane coatings, which prevents further combustion within the polymer. What's more, the prepared waterborne polyurethane shows excellent mechanical properties.
This work evaluates and compares the performance of the radar reflectivity and lightning data assimilation schemes implemented in weather research and forecasting-four-dimensional data assimilation ...(WRF-FDDA) for short-term precipitation and lightning forecasts. All six mesoscale convective systems (MCSs) with a duration greater than seven hours that occurred in the Guangdong Province of China during June 2020 were included in the experiments. The results show that both the radar reflectivity data assimilation and lightning data assimilation improved the analyses and short-term forecasts of the precipitation and lightning of the MCSs. On average, for precipitation forecasts, the experiments with radar reflectivity data assimilation performed better than those with lightning data assimilation; however, for lightning forecasts, the experiments with lightning data assimilation performed better in the analysis period and 1 h forecast, and for some cases, the superiority lasted to three forecast hours. This highlights the potential of lightning data assimilation in short-term lightning forecasting.
Lightning simulation is important for a variety of applications, including lightning forecast, atmospheric chemical simulation, and lightning data assimilation. In this study, the potential of five ...storm parameters (graupel volume, precipitation ice mass, radar echo volume, maximum updraft, and updraft volume) to be used as the proxy for the diagnosis of gridded total lightning flash rates has been investigated in a convection-allowing model. A mesoscale convective system occurred in the Guangdong province of China was selected as the test case. Radar data assimilation was used to improve the simulation accuracy of the convective clouds, hence providing strong instantaneous correlations between observed and simulated storm signatures. The areal coverage and magnitude of the simulated lightning flash rates were evaluated by comparing to those of the total lightning observations. Subjective and the Fractions Skill Score (FSS) evaluations suggest that all the five proxies tested in this study are useful to indicate general tendencies for the occurrence, region, and time of lightning at convection-allowing scale (FSS statistics for the threshold of 1 flash per 9 km2 per hour were around 0.7 for each scheme). The FSS values were decreasing as the lightning flash rate thresholds used for FSS computation increased for all the lightning diagnostic schemes with different proxies. For thresholds from 1 to 3 and 16 to 20 flashes per 9 km2 per hour, the graupel contents related schemes achieved higher FSS values compared to the other three schemes. For thresholds from 5 to 15 flashes per 9 km2 per hour, the updraft volume related scheme yielded the largest FSS. When the thresholds of lightning flash rates were greater than 13 flashes per 9 km2 per hour, the FSS values were below 0.5 for all the lightning diagnostic schemes with different proxies.
Dear Editor, This letter addresses the noncooperative formation control of multiple underactuated autonomous surface vehicles (ASVs) in an obstacle-laden environment. Each ASV is subject to external ...disturbances and fully unknown model parameters. A safety-critical game-based formation control method is proposed such that the multiple ASVs are able to track a reference trajectory, and accomplish each individual interest in safety behaviors simultaneously. The stability and safety analyses show that the closed-loop system is input-to-state stable (ISS), and the multi-ASV system is guaranteed for input-to-state safety (ISSf). Simulation results substantiate the proposed safety-critical game-based formation control method.
The incidence of Talaromyces marneffei (T. marneffei) infection has increased in recent years with the development of organ transplantation and the widespread use of immunosuppressive agents. ...However, the lack of clinical suspicion leading to delay or misdiagnosis is an important reason for the high mortality rate in non-human immunodeficiency virus (HIV) and non-endemic population. Herein, we report a case of disseminated T. marneffei infection in a non-HIV and non-endemic recipient after renal transplant, who initially presented with skin rashes and subcutaneous nodules and developed gastrointestinal bleeding.
We describe a 54-year-old renal transplantation recipient presented with scattered rashes, subcutaneous nodules and ulcerations on the head, face, abdomen, and right upper limb. The HIV antibody test was negative. The patient had no obvious symptoms such as fever, cough, etc. Histopathological result of the skin lesion sites showed chronic suppurative inflammation with a large number of fungal spores. Subsequent fungal culture suggested T. marneffei infection. Amphotericin B deoxycholate was given for antifungal treatment, and there was no deterioration in the parameters of liver and kidney function. Unfortunately, the patient was soon diagnosed with gastrointestinal bleeding, gastrointestinal perforation and acute peritonitis. Then he rapidly developed multiple organ dysfunction syndrome and abandoned treatment.
The risk of fatal gastrointestinal bleeding can be significantly increased in kidney transplant patients with T. marneffei infection because of the long-term side effects of post-transplant medications. Strengthening clinical awareness and using mNGS or mass spectrometry technologies to improve the detection rate and early diagnosis of T. marneffei are crucial for clinical treatment in non-HIV and non-endemic population.
Tetracycline antibiotics play a vital role in animal husbandry, primarily employed to uphold the health of livestock and poultry. Consequently, when manure is reintegrated into farmland, tetracycline ...antibiotics can persist in the soil. Simultaneously, to ensure optimal crop production, organochlorine pesticides (OCPs) are frequently applied to farmland. The coexistence of tetracycline antibiotics and OCPs in soil may lead to an increased risk of transmission of tetracycline resistance genes (TRGs). Nevertheless, the precise mechanism underlying the effects of OCPs on tetracycline antibiotics and TRGs remains elusive. In this study, we aimed to investigate the effects of OCPs on soil tetracycline antibiotics and TRGs using different concentrations of doxycycline (DOX) and pentachlorophenol (PCP). The findings indicate that PCP and DOX mutually impede their degradation in soil. Furthermore, our investigation identifies Sphingomonas and Bacillus as potential pivotal microorganisms influencing the reciprocal inhibition of PCP and DOX. Additionally, it is observed that the concurrent presence of PCP and DOX could impede each other's degradation by elevating soil conductivity. Furthermore, we observed that a high concentration of PCP (10.7 mg/kg) reduced the content of efflux pump tetA, ribosome protective protein tetM, tetQ, and passivating enzyme tetX. In contrast, a low PCP concentration (6.4 mg/kg) only reduced the content of ribosome protective protein tetQ. This suggests that PCP may reduce the relative abundance of TRGs by altering the soil microbial community structure and inhibiting the potential host bacteria of TRGs. These findings have significant implications in understanding the combined pollution of veterinary antibiotics and OCPs. By shedding light on the interactions between these compounds and their impact on microbial communities, this study provides a theoretical basis for developing strategies to manage and mitigate their environmental impact, and may give some information regarding the sustainable use of antibiotics and pesticides to ensure the long-term health and productivity of agricultural systems.
•Pentachlorophenol (PCP) and doxycycline (DOX) inhibit each other's degradation.•Sphingomonas and Bacillus may affect the mutual inhibitory effect of PCP and DOX.•One of the possible inhibitors between PCP and DOX is soil conductivity.•PCP reduced the contents of tetA, tetM, tetQ and tetX.
Dear editor, This letter addresses the multi-target tracking of underactuated unmanned surface vehicles (USVs) subject to multiple stationary/moving obstacles. The kinetic model parameters of each ...USV are totally unknown. A safety-critical model-free control method is proposed for tracking multiple targets with a collision-free containment formation. Specifically, a distributed containment extended state observer (DCESO) is designed to estimate the convex hull spanned by the multiple targets. At the kinematic level, a collision-free kinematic guidance law is presented using a control barrier function (CBF) and an extended state observer for each follower USV. At the kinetic level, a model-free position tracking control law by using an adaptive ESO (AESO) is presented for each follower USV. By the designed safety-critical model-free control method, cooperative tracking of multiple targets under multiple stationary/moving obstacles can be achieved using completely unknown kinetic model parameters. Simulations are provided to illustrate the efficacy of the proposed safety-critical model-free control method for a fleet of USVs.
In this work, we systematically evaluated the effect of Si on the dynamic recrystallization (DRX) during hot deformation behavior of a novel high-strength rolled Medium Mn steel. To this end, the ...novel steel was subjected to compression test in the temperatures of range temperature of 950–1150 °C and the strain rate of range of 0.01–10 s−1. Numerical simulation, constitutive analysis, different models and processing maps were also developed to predict the volume fraction of DRX, which was further confirmed through electron backscatter diffraction (EBSD). The results show that some disparities are existed between the model predictions and the results. The EBSD micrographs of samples displayed prominent discontinuous DRX peak in the true stress-strain curves exhibit conventional equiaxed DRX particles. Most specifically, in initial stages the addition of Si increased the DRX and grain boundary migration, and the later stages of deformation the DRX was triggered after achieving the steady state. Therefore, the final microstructure appears as elongated austenite or localized DRX. Furthermore, the work hardening stage before the new round of DRX nucleation caused the stress to continue to increase after the steady state. These findings provide valuable insights into the complex behavior of materials under the influence of Si addition and enhancing our understanding of microstructural evolution during hot deformation.
Feather pecking (FP) is a maladaptive behavior in laying hens that is associated with numerous physiological traits, including those involving the central neurotransmitter system and the immune ...system, which have been identified in many species as being regulated by the gut microbiota
the "microbiota-gut-brain" (MGB) axis. Yet, it is unknown whether and how gut microbiota influences FP by regulating multiple central neurotransmission systems and immune system.
This study was measured the prevalence of severe FP (SFP) in the commercial layer farm. The chicken flock with the highest frequency of SFP were selected for FP phenotype identification. Nontargeted metabolomics was performed to investigated the differences in the peripheral and central metabolites and 16S rDNA sequencing was performed to investigated the differences in gut microbiome of laying hens with different FP phenotypes. Correlation analysis was performed to determine the potential mechanism by which the disturbed gut microbiota may modulate host physiology and behavior.
The results showed that pullets (12 weeks of age) showed significantly higher SFP frequencies than chicks (6 weeks of age) and adults (22 weeks of age;
< 0.05). Compared to neutrals (N), peckers (P) exhibited the stress-induced immunosuppression with the increased plasma levels of corticosterone and norepinephrine, and the decreased plasma levels of IgA, IL-1, IL-6 and tumor necrosis factor α (
< 0.05). In the cecum, the relative abundances of
and
were higher in the P group, while
,
,
,
and
were more enriched in the N group. Moreover, increased plasma levels of L-tryptophan, beta-tyrosine and L-histidine were found in the P group (
< 0.05). Notably, in the P group, hippocampal levels of L-tryptophan, xanthurenic acid, L-histidine and histamine were improved and showed a positive association with L-glutamic acid levels. Plasma levels of L-tryptophan, beta-tyrosine and L-histidine were both positively correlated with
abundance but negatively correlated with
abundance.
Overall, these findings suggest that the development of FP may be affected by the gut microbiota, which regulates the central glutamatergic nerve system by altering the metabolism of tryptophan, histidine and tyrosine.
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