The biodistribution of polystyrene nanoparticles administered intravenously in the chicken embryo.

Nanoplastics can cause severe malformations in chicken embryos. To improve our understanding of the toxicity of nanoplastics to embryos, we have studied their biodistribution in living chicken embryos. We injected the embryos in the vitelline vein at stages 18-19. We injected polystyrene nanoparticles (PS-NPs) tagged with europium- or fluorescence. Their biodistribution was tracked using inductively-coupled plasma mass spectrometry on tissue lysates, paraffin histology, and vibratome sections analysed by machine learning algorithms. PS-NPs were found at high levels in the heart, liver and kidneys. Furthermore, PS-NPs crossed the endocardium of the heart at sites of epithelial-mesenchymal transformation; they also crossed the liver endothelium. Finally, we detected PS-NPs in the allantoic fluid, consistent with their being excreted by the kidneys. Our study shows the power of the chicken embryo model for analysing the biodistribution of nanoplastics in embryos. Such experiments are difficult or impossible in mammalian embryos. These findings are a major advance in our understanding of the biodistribution and tissue-specific accumulation of PS-NPs in developing animals.

A life-history allele of large effect shortens developmental time in a wild insect population.

Developmental time is a key life-history trait with large effects on Darwinian fitness. In many insects, developmental time is currently under strong selection to minimize ecological mismatches in seasonal timing induced by climate change. The genetic basis of responses to such selection, however, is poorly understood. To address this problem, we set up a long-term evolve-and-resequence experiment in the beetle Tribolium castaneum and selected replicate, outbred populations for fast or slow embryonic development. The response to this selection was substantial and embryonic developmental timing of the selection lines started to diverge during dorsal closure. Pooled whole-genome resequencing, gene expression analysis and an RNAi screen pinpoint a 222 bp deletion containing binding sites for Broad and Tramtrack upstream of the ecdysone degrading enzyme Cyp18a1 as a main target of selection. Using CRISPR/Cas9 to reconstruct this allele in the homogenous genetic background of a laboratory strain, we unravel how this single deletion advances the embryonic ecdysone peak inducing dorsal closure and show that this allele accelerates larval development but causes a trade-off with fecundity. Our study uncovers a life-history allele of large effect and reveals the evolvability of developmental time in a natural insect population.

Nanoplastics causes extensive congenital malformations during embryonic development by passively targeting neural crest cells.

Nanomaterials are widespread in the human environment as pollutants, and are being actively developed for use in human medicine. We have investigated how the size and dose of polystyrene nanoparticles affects malformations in chicken embryos, and have characterized the mechanisms by which they interfere with normal development. We find that nanoplastics can cross the embryonic gut wall. When injected into the vitelline vein, nanoplastics become distributed in the circulation to multiple organs. We find that the exposure of embryos to polystyrene nanoparticles produces malformations that are far more serious and extensive than has been previously reported. These malformations include major congenital heart defects that impair cardiac function. We show that the mechanism of toxicity is the selective binding of polystyrene nanoplastics nanoparticles to neural crest cells, leading to the death and impaired migration of those cells. Consistent with our new model, most of the malformations seen in this study are in organs that depend for their normal development on neural crest cells. These results are a matter of concern given the large and growing burden of nanoplastics in the environment. Our findings suggest that nanoplastics may pose a health risk to the developing embryo.

Change and convergence of innovation efficiency among listed health companies in China: Empirical study based on the DEA-Malmquist model.

This study investigates the present situation of and changing trend in the innovation efficiency of health industry enterprises in China. Based on panel data for 192 listed health companies in China from 2015 to 2020, we analyse innovation efficiency using the DEA-Malmquist index and test convergence using σ-convergence and ß-convergence models. From 2016 to 2019, comprehensive average innovation efficiency increased from 0.6207 to 0.7220 and average innovation efficiency decreased significantly in 2020. The average Malmquist index was 1.072. Innovation efficiency in China as a whole, North China, South China, and Northwest China showed σ-convergence. Except for the Northwest region, absolute ß-convergence was evident, and in China as a whole, North China, Northeast China, East China, and South China, conditional ß-convergence was evident. Overall innovation efficiency of these companies has increased annually but needs further improvement, and the COVID-19 pandemic has had a great negative impact on it. Innovation efficiency and trends in it vary across regions. Furthermore, we should pay attention to the impacts of innovation infrastructure and government scientific and technological support on innovation efficiency.

Influencing Mechanism and Difference of Poultry Farmers' Willingness and Behavior in Breeding Scale-Evidence from Jianghan Plain, China.

This paper uses the Heckprobit two-stage econometric model to explore the influence mechanism of poultry farmers' willingness and behavior regarding scale based on 269 household survey data in the hinterland of Jianghan Plain, China. The results show that (1) family endowments, social capital, economic capital, product market prediction, and major public emergencies are the main influencing factors for farmers to engage in poultry farming; (2) economic capital, policy guarantees, product market prediction, and major public emergencies are the main factors that influence the changes in farmers' poultry breeding scale; and (3) sampled poultry farmers are inconsistent between their breeding willingness and breeding behavior in poultry decision-making and the factors that affect the willingness and behavior are varied. Based on these findings, this paper suggests that the government should pay attention to inducing corresponding assistance and subsidy policies, formulating financial support countermeasures, organizing training and exchange meetings of the breeding industry, and promoting poultry market informatization to help the poultry industry prosper.

The effects of subway openings on air quality: evidence from China.

This paper examines a causal relationship between the opening of a city's subway system and its air quality by exploiting daily data on prefecture-level cities in China from 2000 to 2012. Using multi-period difference in differences (DID) method, we find that air quality can be significantly improved following a subway system opening. Robustness tests support the fundamental empirical results. Heterogeneity analysis shows that cities in the eastern and western regions and cities with higher GDP or cities with larger population experience greater and more significant reduction in pollution. We further find that the air pollution continues to decrease with the extension and prolonged operating period of a subway system. Mechanism analysis shows that the resulted air pollution index (API) reduction is due to the substitution effect of taxi.

China's Carbon Emissions and Trading Pilot, Political Connection, and Innovation Input of Publicly Listed Private Firms.

Taking China's carbon emissions and trading pilot (CCETP) as a quasi-natural experiment, this paper examines the impact of CCETP on publicly listed private firms' innovation input and the moderating effect of the firms' political connection based on the difference-in-differences model. The results show that CCETP has a significantly positive effect on the innovation input of Chinese publicly listed private firms. Moreover, the political connection of executives exhibits a positive moderating effect on CCETP's impact on innovation input. Meanwhile, the effect is more significant in regions with high environmental protection investment and large publicly listed private firms. The conclusions could provide some policy enlightenment for China's carbon market, as well as a rational adjustment of the relationship between political connection and innovation input of publicly listed private firms in the future.

Measuring the Environmental Efficiency and Technology Gap of PM2.5 in China's Ten City Groups: An Empirical Analysis Using the EBM Meta-Frontier Model.

Since air pollution is an important factor hindering China's economic development, China has passed a series of bills to control air pollution. However, we still lack an understanding of the status of environmental efficiency in regard to air pollution, especially PM2.5 (diameter of fine particulate matter less than 2.5 µm) pollution. Using panel data on ten major Chinese city groups from 2004 to 2016, we first estimate the environmental efficiency of PM2.5 by epsilon-based measure (EBM) meta-frontier model. The results show that there are large differences in PM2.5 environmental efficiency between cities and city groups. The cities with the highest environmental efficiency are the most economically developed cities and the city group with the highest environmental efficiency is mainly the eastern city group. Then, we use the meta-frontier Malmquist EBM model to measure the meta-frontier Malmquist total factor productivity index (MMPI) in each city group. The results indicate that, overall, China's environmental total factor productivity declined by 3.68% and 3.49% when considering or not the influence of outside sources, respectively. Finally, we decompose the MMPI into four indexes, namely, the efficiency change (EC) index, the best practice gap change (BPC) index, the pure technological catch-up (PTCU) index, and the frontier catch-up (FCU) index. We find that the trend of the MMPI is consistent with those of the BPC and PTCU indexes, which indicates that the innovation effect of the BPC and PTCU indexes are the main driving forces for productivity growth. The EC and FCU effect are the main forces hindering productivity growth.

Identification and expression analysis of a TLR11 family gene in the sea urchin Strongylocentrotus intermedius.

In this study, a homolog of the TLR11 family gene from the sea urchin Strongylocentrotus intermedius (denoted as SiTLR11) was cloned and characterized. The full-length cDNA of SiTLR11 was 2096-bp long, which included 43 bp of 5' untranslated region (UTR), 238 bp of 3' UTR, and a putative open reading frame of 1815 bp encoding a polypeptide of 604 amino acid residues. Representative domains such as leucine-rich repeat (LRR) (residues 108-249) and a cytoplasmic Toll-interleukin-1 receptor (TIR) (residues 429-571) domains were detected in the predicted amino acid sequence of SiTLR11. SiTLR11 transcript was widely distributed in all the tested tissues, including intestine, tube feet, gonad, coelomocytes, and peristomial membrane, with the highest expression level in the coelomocytes and peristomial membrane. After the sea urchin was injected with polyinosinic:polycytidylic acid (PolyI:C), the expression level of SiTLR11 in the coelomocytes increased significantly, reaching 1.96-fold the level of the control at 12 h, but decreased to level below that of control at 24 and 48 h. Injection of peptidoglycan (PGN) also led to increased expression of SiTLR11, which peaked at 12 h, yielding an increase of 2.19-fold compared to the control group, and continued to increase at 24 and 48 h. However, almost no differences in immunological activity were found in the groups challenged with lipopolysaccharides (LPS), Zymosan A (ZOA), or Vibrio fortis compared to the control. Taken together, the results strongly suggested that SiTLR11 was functionally involved in the immune response triggered by double-stranded RNA (dsRNA) viruses and Gram-positive bacteria.

Characterization and expression analysis of a thioredoxin-like protein gene in the sea cucumber Apostichopus japonicus.

As the most important disulfide bond reducates of intracellular oxidordeuctase, thioredoxin (TRX) plays a crucial role in maintaining reducing state of intracellular proteins to normally perform their function. In this study, a cDNA of TRX-like protein gene from Apostichopus japonicus (denoted as AjTRX) was cloned and characterized. The full-length cDNA of AjTRXwas of 1870 bp, consisting of a 5'-UTR of 101 bp, a long 3'-UTR of 887 bp and a 882 bp open reading frame (ORF) encoding a 293 amino acids. The predicted molecular mass and the theoretical PI of the deduced amino acids of AjTRX were 32.3 kDa and 5.52, respectively. Phylogenetic trees showed that AjTRX had a closer evolution relationship with TRX from Strongylocentrotus purpuratus. AjTRX was found to be ubiquitously expressed in all examined tissues including longitudinal muscle, coelomocytes, tube feet, intestine, respiratory tree and body wall indicating a general role in physiological processes. Temporal expression pattern of AjTRX in coelomocytes showed that AjTRX reached two peak expression levels at 8 h and 48 h after Vibrio splendidus challenge with a 8.6 and 9.3-fold increase compared to their control groups, respectively. The recombinant AjTRX protein (rAjTRX) displayed obvious antioxidant activity in a dose-dependent manner, and the higher reducing activity was detected in 20 µM experimental group. All these results strongly suggested that AjTRX could play an important role as an antioxidant in a physiological context, and might be involved in the process of bacterial challenge.