Unique nucleolar dominance patterns in distant hybrid lineage derived from Megalobrama Amblycephala × Culter Alburnus

The peak figures of the PCR products sequencing. A, The sequencing peak figures of the PCR products amplified from genomic and cDNA of 18S rRNA gene in BSB and TC. B, The sequencing peak figures of the PCR products amplified from genomic and cDNA of 18S rRNA gene in F1 hybrids of BSB × TC. C, The sequencing peak figures of the PCR products amplified from genomic and cDNA of 18S rRNA gene in F2 hybrids of BSB × TC. Only the SNP site and 2 upstream and downstream nucleotides are showed. Note: For every pattern of each kind of fish, one sample was used to present. (PPT 275 kb

Front-running Attack in Sharded Blockchains and Fair Cross-shard Consensus

Sharding is a prominent technique for scaling blockchains. By dividing the network into smaller components known as shards, a sharded blockchain can process transactions in parallel without introducing inconsistencies through the coordination of intra-shard and cross-shard consensus protocols. However, we observe a critical security issue with sharded systems: transaction ordering manipulations can occur when coordinating intra-shard and cross-shard consensus protocols, leaving the system vulnerable to attack. Specifically, we identify a novel security issue known as finalization fairness, which can be exploited through a front-running attack. This attack allows an attacker to manipulate the execution order of transactions, even if the victim's transaction has already been processed and added to the blockchain by a fair intra-shard consensus. To address the issue, we offer Haechi, a novel cross-shard protocol that is immune to front-running attacks. Haechi introduces an ordering phase between transaction processing and execution, ensuring that the execution order of transactions is the same as the processing order and achieving finalization fairness. To accommodate different consensus speeds among shards, Haechi incorporates a finalization fairness algorithm to achieve a globally fair order with minimal performance loss. By providing a global order, Haechi ensures strong consistency among shards, enabling better parallelism in handling conflicting transactions across shards. These features make Haechi a promising solution for supporting popular smart contracts in the real world. To evaluate Haechi's performance, we implemented the protocol using Tendermint and conducted extensive experiments on a geo-distributed AWS environment. Our results demonstrate that Haechi achieves finalization fairness with little performance sacrifice compared to existing cross-shard consensus protocols

The Sterility of Allotriploid Fish and Fertility of Female Autotriploid Fish

Based on the formation of an autotetraploid fish line (4nAUT, 4n = 200; F2–F11) derived from the distant hybridization of female Carassius auratus red var. (RCC, 2n = 100) × male Megalobrama amblycephala (BSB, 2n = 48), we produced autotriploid hybrids (3nAUT) by crossing females of RCC with males of 4nAUT and allotriploid hybrids (3nALT) by crossing females of Cyprinus carpio (CC, 2n = 100) with males of 4nAUT. The aim of this study was to comparatively investigate the reproductive characteristics of 3nALT and 3nAUT. We investigated morphological traits, chromosomal numbers, DNA content and gonadal development in 3nAUT and 3nALT. The results indicated both 3nAUT and 3nALT possessed 150 chromosomes and were triploid hybrids. The females and males of 3nALT and males of 3nAUT had abnormal gonadal development and could not generate mature eggs or sperm, but the females of 3nAUT had normal gonadal development and generated mature eggs at 2 years old. The females of 3nAUT generated different sizes of eggs, which fertilized with haploid sperm from RCC and formed viable diploid, triploid, and tetraploid offspring. The formation of these two kinds of triploid hybrids provides an ideal model for studying the reproductive traits of triploid hybrids, which is of great value in animal genetics and reproductive biology

Nitrogen Removal from the Simulated Wastewater of Ionic Rare Earth Mining Using a Biological Aerated Filter: Influence of Medium and Carbon Source

In engineering application, a two-stage biological aerated filter (BAF) has been deployed to achieve the steady nitrogen removal of the wastewater from the mining area of ionic rare earth with a low carbon to nitrogen (C/N) ratio. However, the cost-efficiency of the medium and carbon source casts a shadow over further development. In this study, the influences of four media (i.e., volcanic, zeolite, quartz, and ceramisite) and three soluble carbon sources (i.e., acetate, glucose, and methanol) on the N removal were systematically compared. Applying volcanic and quartz showed a favorable start-up performance due to the biophilic surface and dense packing, respectively. However, regardless of medium type, with [NH4+-N]0 = 50 and [NO3−-N]0 = 30 mg/L, the C/N ratio of 3 was required to meet the discharge standards of NH4+-N, TN, and COD, and acetate was confirmed applicable for all the selected medium-packed BAFs. Introduction of sweet potato residues as the solid carbon source decreased the amount of added acetate by more than 13%. The 16S rRNA high-throughput gene sequencing revealed that Sphingomonas and Nitrospira were abundant in the aerobic stages of the volcanic and zeolite-packed BAFs, respectively. Such a community integrated with the extensively distributed Thauera, Clostridium_sensu_stricto, and Proteiniclasticum in the anoxic stage accounted for the efficient N removal. Thus, deploying volcanic as the medium and acetate as the soluble carbon source was proposed. These findings will provide valuable references for the selection of medium and carbon source and, consequently, further optimize the operational performance

Grafting of R4N+-Bearing Organosilane on Kaolinite, Montmorillonite, and Zeolite for Simultaneous Adsorption of Ammonium and Nitrate

Modification of aluminosilicate minerals using a R4N+-bearing organic modifier, through the formation of covalent bonds, is an applicable way to eliminate the modifier release and to maintain the ability to remove cationic pollutants. In this study, trimethyl [3-(trimethoxysilyl) propyl] ammonium chloride (TM) and/or dimethyl octadecyl [3-(trimethoxysilyl) propyl] ammonium chloride (DMO) were used to graft three aluminosilicate minerals, including calcined kaolinite (Kaol), montmorillonite (Mt), and zeolite (Zeol), and the obtained composites were deployed to assess their performance in regard to ammonium (NH4+) and nitrate (NO3−) adsorption. Grafting of TM and/or DMO had little influence on the crystal structures of Kaol and Zeol, but it increased the interlayer distance of Mt due to the intercalation. Compared to Kaol and Zeol, Mt had a substantially greater grafting concentration of organosilane. For Mt, the highest amount of loaded organosilane was observed when TM and DMO were used simultaneously, whereas for Kaol and Zeol, this occurred when only DMO was employed. 29Si-NMR spectra revealed that TM and/or DMO were covalently bonded on Mt. As opposed to NO3−, the amount of adsorbed NH4+ was reduced after TM and/or DMO grafting while having little effect on the adsorption rate. For the grafted Kaol and Zeol, the adsorption of NH4+ and NO3− was non-interfering. This is different from the grafted Mt where NH4+ uptake was aided by the presence of NO3−. The higher concentration of DMO accounted for the larger NO3− uptake, which was accompanied by improved affinity. The results provide a reference for grafting aluminosilicate minerals and designing efficient adsorbents for the co-adsorption of NH4+ and NO3−

Modification of ultrasound-pretreated montmorillonite using poly(diallyldimethylammonium chloride) for W and Mo separation and the sequential application in removal of heavy metals

The use of a resin to selectively separate thiomolybdate from a tungsten (W) feed solution is a well-known protocol for achieve high-purity W products; however, the regeneration of saturated resin is laborious. In this study, poly(diallyl dimethyl ammonium chloride) (PDADMA) was used to modify ultrasound-pretreated montmorillonite (Mt) for W and molybdenum (Mo) separation for the first time, and the resultant tetrathiomolybdate (MoS42-)-loaded composite was further tested to remove heavy metals instead of regeneration. Among the three variables of ultrasound pretreatment, that is, Mt concentration, ultrasound power, and treatment time, the Mt concentration exhibited the most significant influence followed by ultrasound power on the separation performance of W and Mo. Compared to the distance of the interlayer space and the surface charge of the modified Mt, the PDADMA content showed a closer correlation with the W/Mo separation coefficient. Assisted by Box–Behnken design, with Mt concentration of 6.9 g/L, ultrasound power of 593.8 W, and treatment time of 13.8 min, the composite with the greatest separation coefficient was obtained. The adsorption of Cu(II) on the optimal W/Mo separation-derived composite was ascribed to the formation of Cu-S complexes, while that of Pb(II) was attributed to complexation and surface precipitation. In contrast, ion exchange with the initially loaded anions, reduction by sulfide to Cr(III), and formation of Cr(III)-S complexes accounted for Cr(VI) removal. The adsorption of Cu(II) and Pb(II) equilibrated faster and showed higher acid-resistance than that of Cr(VI). The adsorption capacities for Cu(II), Pb(II), and Cr(VI) were 0.535, 1.398, and 0.882 mmol/g, respectively. Applying PDADMA to modify Mt as a reagent for W/Mo separation was feasible, and the derived composite was capable of removing cationic and anionic heavy metals

Highly efficient potassium fertilizer production by using a gemini surfactant

Herein, we report that a gemini surfactant can efficiently separate KCl from NaCl by froth flotation to produce potassium fertilizer (KCl). For achieving the obviously superior flotation performance (KCl recovery increased by 14.51%), the dosage of the gemini surfactant should be three times less than that of the conventional monomeric surfactant. Its unique properties, such as double active centers to mineral surfaces, double hydrophobic groups, and stronger surface tension reducing ability, make it a superior flotation collector for separation of KCl from NaCl in potassium fertilizer production

Gemini surfactant: A novel flotation collector for harvesting of microalgae by froth flotation

Froth flotation has been proved to be a promising approach for commercial scale harvesting of microalgae. However, all the surfactants used in the microalgae flotation harvesting process are conventional monomeric surfactants contain a single similar hydrophobic group in the molecule, which results in a low harvesting efficiency. In this work, a novel Gemini surfactant, N,N′-bis(cetyldimethyl)-1,4-butane diammonium dibromide (BCBD) was prepared, and originally recommended as a collector for froth flotation harvesting of Chlorella vulgaris from culture medium. The performance of BCBD was compared with the results acquired using its conventional monomeric surfactant cetyl trimethyl ammonium bromide (CTAB). The bench-scale flotation results showed that BCBD had excellent collecting power for Chlorella vulgaris. Achieving the obviously superior flotation harvesting performance (flotation recovery increased by 21.4% and enrichment ratio increased by 22.9), the dosage of Gemini type BCBD collector is five times less than that of monomeric CTAB collector

Utilization of a new Gemini surfactant as the collector for the reverse froth flotation of phosphate ore in sustainable production of phosphate fertilizer

An effective collector plays a vital role in the reverse flotation of phosphate ore as well as sustainable production of phosphate fertilizer. Phosphate fertilizer is used to achieve the sustainable increase in the production of food. Phosphate ore is concentrated by reverse froth flotation and used as a raw material to produce phosphate fertilizer in industry. However, all the surfactants used in the phosphate ore reverse flotation process are conventional monomeric surfactants contain a single similar hydrophobic group in the molecule, which results in a low production efficiency and severe environmental contamination. In this work, a novel Gemini surfactant, N,N′-bis(dodecyldimethyl)-1,4-butane diammonium dibromide (BDBD) was prepared, and originally recommended as a collector for reverse froth flotation separation of silicoide from phosphate ore. The performance of BDBD was compared with the results acquired using its conventional monomeric surfactant dodecylamine hydrochloride (DAH). The bench-scale flotation results showed that BDBD had excellent collecting power for silicoide and significant selectivity against apatite at pH 9. Moreover, BDBD presented stronger desilication efficiency than DAH. Achieving the superior flotation performance (P O recovery increased by 2.41%, P O content increased by 0.26%, and SiO content reduced by 2.52%), the dosage of Gemini type BDBD collector (100 g/t) is four times less than that of monomeric DAH collector (400 g/t). Therefore, this work provides a promising approach to the sustainable phosphate fertilizer production and to address global food security concerns