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In the context of the circular economy, there is a need for advanced methods to recover metals from industrial waste, yet classical hydrometallurgical techniques are limited. Here, we review ultrasonic-assisted hydrometallurgical leaching with focus on the use of acids, bases, oxidants, bacteria and electrolysis. Oxidative leaching is done with ferric ions, dioxygen, ozone and hydrogen peroxide. Upscaling is also detailed. Ultrasonication allows to reduce the dosage of leaching agents, to reduce reaction time, and to enhance leaching efficiency. Large-scale equipments are still limited by low cavitation efficiency, low throughput, high usage costs, and high energy consumption. [ABSTRACT FROM AUTHOR]

Simple Summary: Pathogens of diseases in branches and trunks are commonly inoculated through punching, burning, and toothpick inoculation. At present, there is a lack of comparative analyses of the inoculation outcomes of these three methods. We determined that toothpick inoculation is an optimal option for studying the pathogenesis of Valsa sordida in six-year-old Populus alba var. pyramidalis, providing technical support for research on poplar diseases and offering a theoretical basis for the inoculation of other diseases in branches and trunks. A key step in the study of tree pathology is the identification of an appropriate method for inoculating pathogens of diseases in branches and trunks. Pathogens of diseases in branches and trunks are commonly inoculated through punching, burning, and toothpick inoculation. However, there is a lack of comparative analyses of the inoculation outcomes of these three methods. In this work, six-year-old P. alba var. pyramidalis were inoculated with V. sordida using punching, burning, and toothpick techniques to investigate the differences in the effectiveness of these inoculation methods. Results reveal that the incidence rate was 93.55% in the toothpick inoculation group, significantly higher than the 80.65% in the burning inoculation group (chi-square, n = 90, p = 0.007), while punching inoculation exhibited significant pathological responses in the early stages, with spontaneous healing in the later stage. Additionally, toothpick inoculation was more efficient in inducing Valsa canker when inoculating the pathogen at the bottom of the tree, with lower intra- and inter-row spacing (stand density) providing better outcomes than higher intra- and inter-row spacing. The results of this study demonstrate that toothpick inoculation is an optimal option for studying the artificial inoculation of V. sordida in six-year-old P. alba var. pyramidalis, providing technical support for research on poplar diseases and offering a theoretical basis for the inoculation of other diseases in the branch and trunk. [ABSTRACT FROM AUTHOR]

Insect infestations cause substantial changes in the leaves they attack, but the effects of insect infestation on photosynthesis and gene expression in the whole infestation period are rarely reported. In this study, the effects of poplar aphid (Chaitophorus populialbae Boyer de Fonscoloube) on photosynthetic rate and gene expression of Populus alba var. pyramidalis were studied, from 2 to 36 days after low-density aphid inoculation (DAI). The results revealed a dynamic change of photosynthesis in poplar after aphid infestation: compensatory increased at 8 DAI, was inhibited at 17 DAI, but repaired after 21 DAI. Aphid infestation promoted the expression of the majority of differentially expressed genes (DEGs) at 4, 6, 8, and 21 DAI. The DEGs were enriched into a plant–pathogen interaction, plant hormone signal transduction, and MAPK signaling pathway, suggesting a significant but transient resistance to disease or other stresses. Photosynthesis-related DEGs were downregulated at 8 DAI, which might result in photosynthetic inhibition at 17 DAI. The expression of flavonoid biosynthesis-related DEGs dynamic changed from all downregulated at 2 DAI to almost all upregulated at 21 DAI, suggesting a persistent resistance to insect infestation. This study reveals dynamic changes in photosynthesis, resistance to pathogens, and insects in poplar leaves after aphid infestation. [ABSTRACT FROM AUTHOR]

In this study, two poplar varieties with different resistance to sulfur dioxide were selected for a comparative experiment. SO2 fumigation to the poplars was carried out under controlled conditions to determine the variation in the activity of enzymes, the content of metabolites and the expression of enzymes genes in pathways of sulfur metabolism in plants. The results showed that the activity of enzymes and the content of sulfur metabolites were closely related to the response of the poplars to SO2 stress. Populus × euramericana cv. 'Purui' had two ways of detoxification: oxidation detoxification, oxidizing sulfite (SO32−) to sulfate SO42− by sulfite oxidase; reductive detoxification, SO32− being reduced to S2− by sulfite reductase (SiR). Moreover, OASTL and SAT activity, and levels of cysteine (CYS) and glutathione (GSH) also increased in P. × euramericana cv. 'Purui' in response to SO2 fumigation, and the gene expression encoding Glutathione S-transferases (GST), and some enzymes in cysteine and methionine metabolism was up-regulated. For Populus × euramericana cv. '74/76' with weaker resistance to sulfur dioxide, it only detoxified by increasing the activity of SiR, and but down-regulated the expression of gene encoding 3'-phosphoadenosine 5'-phosphosulfate synthase (PAPSS), which could affect the consumption of sulfite in the exposure to SO2. Thus, the SO2-resistant difference of the two poplar varieties is mainly attributed to variation in activity of the enzymes and content of their metabolites in pathways of sulfur metabolism, and gene expression of some enzymes in cysteine and methionine metabolism also plays a role in the resistant difference. [ABSTRACT FROM AUTHOR]

Botryosphaeriaceae , as a major family of the largest class of kingdom fungi Dothideomycetes , encompasses phytopathogens, saprobes, and endophytes. Many members of this family are opportunistic phytopathogens with a wide host range and worldwide geographical distribution, and can infect many economically important plants, including food crops and raw material plants for biofuel production. To date, however, little is known about the family evolutionary characterization, mating strategies, and pathogenicity-related genes variation from a comparative genome perspective. Here, we conducted a large-scale whole-genome comparison of 271 Dothideomycetes , including 19 species in Botryosphaeriaceae. The comparative genome analysis provided a clear classification of Botryosphaeriaceae in Dothideomycetes and indicated that the evolution of lifestyle within Dothideomycetes underwent four major transitions from non-phytopathogenic to phytopathogenic. Mating strategies analysis demonstrated that at least 3 transitions were found within Botryosphaeriaceae from heterothallism to homothallism. Additionally, pathogenicity-related genes contents in different genera varied greatly, indicative of genus-lineage expansion within Botryosphaeriaceae. These findings shed new light on evolutionary traits, mating strategies and pathogenicity-related genes variation of Botryosphaeriaceae. [ABSTRACT FROM AUTHOR]

Soap stocks are by-products obtained during the refining process of vegetable oil, and are mainly feedstocks to produce acidified oil. In this work, an efficient process was developed to convert soap stock into a high-quality biofuel with low impurity content. A combination of acidification and catalytic cracking reactions employed as pretreatment was investigated to decrease the impurity content in the soap stock feedstock for obtaining a value-added biofuel. A high olefin content (approximately 47%) pyrolytic oil was obtained during the pretreatment. For further improvement of the cold flow properties, hydro-isomerization of pyrolytic oil for the formation of iso-alkanes over the Ce–Pt/SAPO-11and Ce–Pt/ZSM-5 catalysts was then carried out. The isomerization reaction temperature could be decreased to 320 °C because of the approximately 47% olefin content. The cold filter plugging point (CFPP) of the resulting product could be obtained at −11 °C, and the sulfur content could be decreased to lower than 10 ppm, which could meet the EN and ASTM specifications. [ABSTRACT FROM AUTHOR]

Time series classification (TSC) arises in many fields and has a wide range of applications. Here, we adopt the bag-of-words (BoW) framework to classify time series. Our algorithm first samples local subsequences from time series at feature-point locations when available. It then builds local descriptors, and models their distribution by Gaussian mixture models (GMM), and at last it computes a Fisher Vector (FV) to encode each time series. The encoded FV representations of time series are readily used by existing classifiers, e.g., SVM, for training and prediction. In our work, we focus on detecting better feature points and crafting better local representations, while using existing techniques to learn codebook and encode time series. Specifically, we develop an efficient and effective peak and valley detection algorithm from real-case time series data. Subsequences are sampled from these peaks and valleys, instead of sampled randomly or uniformly as was done previously. Then, two local descriptors, Histogram of Oriented Gradients (HOG-1D) and Dynamic time warping-Multidimensional scaling (DTW-MDS), are designed to represent sampled subsequences. Both descriptors complement each other, and their fused representation is shown to be more descriptive than individual ones. We test our approach extensively on 43 UCR time series datasets, and obtain significantly improved classification accuracies over existing approaches, including NNDTW and shapelet transform. [ABSTRACT FROM PUBLISHER]

It is of great importance to explore the selective hydrogenolysis of β-O-4 linkages, which account for 45–60% of all linkages in native lignin, to produce valued-added chemicals and fuels from biomass employing UV light as catalyst. TiO2 exhibited satisfactory catalytic performances in various photochemical reactions, due to its versatile advantages involving high catalytic activity, low cost and non-toxicity. In this work, 20 wt.% Ni/TiO2 and oxidant PCC (Pyridinium chlorochromate) were employed to promote the cleavage of β-O-4 alcohol to obtain high value chemicals under UV irradiation at room temperature. The Ni/TiO2 photocatalyst can be magnetically recovered and efficiently reused in the following four consecutive recycling tests in the cleavage of β-O-4 ether bond in lignin. Mechanism studies suggested that the oxidation of β-O-4 alcohol to β-O-4 ketone by oxidant PCC first occurred during the reaction, and was followed by the photocatalysis of the obtained β-O-4 ketone to corresponding acetophenone and phenol derivates. Furthermore, the system was tested on a variety of lignin model substrates containing β-O-4 linkage for the generation of fragmentation products in good to excellent results. [ABSTRACT FROM AUTHOR]

Embryo implantation in the mink follows the pattern of many carnivores, in that preimplantation embryo diapause occurs in every gestation. Details of the gene expression and regulatory networks that terminate embryo diapause remain poorly understood. Illumina RNA-Seq was used to analyze global gene expression changes in the mink uterus during embryo diapause and activation leading to implantation. More than 50 million high quality reads were generated, and assembled into 170,984 unigenes. A total of 1684 differential expressed genes (DEGs) in uteri with blastocysts in diapause were compared to the activated embryo group (p < 0.05). Among these transcripts, 1527 were annotated as known genes, including 963 up-regulated and 564 down-regulated genes. The gene ontology terms for the observed DEGs, included cellular communication, phosphatase activity, extracellular matrix and G-protein couple receptor activity. The KEGG pathways, including PI3K-Akt signaling pathway, focal adhesion and extracellular matrix (ECM)-receptor interactions were the most enriched. A protein-protein interaction (PPI) network was constructed, and hub nodes such as VEGFA, EGF, AKT, IGF1, PIK3C and CCND1 with high degrees of connectivity represent gene clusters expected to play an important role in embryo activation. These results provide novel information for understanding the molecular mechanisms of maternal regulation of embryo activation in mink. [ABSTRACT FROM AUTHOR]

The complete mitochondrial genome (mtDNA) of Peking duck (Anas platyrhychos) was determined. The entire genome was 16,604 bp in length. Similar to the typical mtDNA of vertebrates, it contained 37 genes (13 protein-coding genes, 2 rRNA genes, 22 tRNA genes) and a non-coding region (D-loop). The characteristics of the mitochondrial genome was analyzed and discussed in detail. [ABSTRACT FROM AUTHOR]

The raccoon dog (Nyctereutes procyonoides) is an important canid fur-bearing animal species worldwide. Chinese raccoon dogs that present a white mutation, especially those with a white coat. Exploring melanin biosynthesis in the hair and skin of raccoon dogs is important for understanding the survival and evolutionary mechanisms of them. In this study, we measured the content of melanin in the hair of two types of raccoon dog and generated stained slices of skin tissue. The results indicated that melanin biosynthesis occurs in the wild-type (W) and white-type (B) raccoon dog skin, although less melanin is produced in B skin. We then sequenced the skin transcriptomes of W and B, compared the similarities and differences in expressed genes. A comparison of the gene expression showed 60 up-regulated genes and 127 down-regulated genes in B skin. We analyzed the unigenes and pathways related to the melanogenesis pathway and found that TYR, TYRP1, MC1R, SLC24a5, SLC45a2 and OCA2 were significantly down-regulated in B skin and these results were verified via qRT-PCR. We surmised that the phenotypic characteristics of the white mutation might be caused by the reduced expression of these genes and this finding provides new insights for future experiments in raccoon dogs. [ABSTRACT FROM AUTHOR]

An understanding of the mechanisms of reactive Al and AlN in a sodium aluminate solution contributes to the safe and effective utilization of secondary aluminum dross (SAD). This study demonstrates that the slurry temperature increased exponentially with an increase in the SAD dosage. Synergistic kinetic phenomena in the form of a large dosage and high temperature occurred initially in relatively stable microbubbles and later in the slurry. The leaching efficiencies of pure Al and AlN powders were greater than that of Al and AlN in SAD, respectively. Meanwhile, the leaching rate became higher for Al in SAD but lower for AlN in SAD compared to that of pure Al and AlN powder. The AlN particles in SAD were covered by Al(OH) 3 precipitated from the saturated solution in the bubbles. As a result, the relatively stable microbubbles with a thick border accelerated the reaction of Al and AlN and produced a saturated solution thereby changing the leaching efficiency and leaching rate of AlN in SAD. The embedded Al and AlN grains in the SAD, relatively stable microbubbles, and the SAD particles covered by Al(OH) 3 , synergistically changed the leaching mechanism. These results provide further understanding of the reaction mechanism of rich bubbles and facilitate the optimization of the comprehensive utilization of SAD. • Temperature of the slurry increased exponentially as the dosage of SAD increased. • Both large dosage and high temperature generated leaching kinetic synergy. • Synergistic kinetics occured first in the bubbles during the leaching of SAD. • Leaching mechanism of SAD in sodium aluminate solution depends on the rich bubbles. [ABSTRACT FROM AUTHOR]

• Metal oxide modified Ni-based catalysts were tested in the selective hydrogenation of fatty acids to fatty alcohols. • CeO 2 supported Ni-MoO x bimetallic catalyst showed the best catalytic performance under mild conditions. • Ni species were decorated by MoO x and charge transfer from Ni to Mo in the Ni-MoO x /CeO 2 bimetallic catalyst. • The synergistic effect between Ni and MoO x facilitated the selective hydrogenation of fatty acids. To develop an efficient Ni-based catalyst for converting renewable fatty acids into high value-added fatty alcohols under mild reaction conditions, the scope of metal oxide modified nickel catalysts was scrutinized. The results show that MoO x modified Ni/CeO 2 catalyst exhibits the excellent catalytic performance in the conversion of fatty acids to form corresponding alcohols at mild reaction conditions (235 °C, 3.0 MPa H 2). Using stearic acid as a model substrate, Ni-MoO x /CeO 2 catalyst shows the 98.0% conversion and 96.2% selectivity to stearyl alcohol, which is significantly higher than that of Ni/CeO 2 catalyst and of a physical mixture of both Ni/CeO 2 and MoO x /CeO 2. Detailed characterization (XRD, Raman, XPS, in situ CO-FTIR, HRTEM, and EPR) indicates that NiMoO 4 is the mainly active phase in the pre-reduced bimetallic catalysts. After reduction at 500 °C in a H 2 flow, the surface of Ni metal is decorated by the MoO x species, the phenomenon is similar to the strong metal-support interaction (SMSI) previously observed on reducible oxides. The presence of MoO x species in the bimetallic Ni-MoO x /CeO 2 catalyst not only improves the dispersion of metallic Ni, but also promotes the charge transfer from Ni to Mo. The electronic interaction at the interface of Ni and MoO x provides synergistic catalysis sites of electron-deficient Ni and MoO x species, which is primarily responsible for the excellent catalytic performance of the bimetallic Ni-MoO x catalyst. Additionally, the introduction of Mo species provides much oxygen vacancy sites for the adsorption of fatty acids, which results in high activity for the conversion of fatty acids. The insights into the synergistic catalysis between Ni and MoO x will provide new possibilities in the design of efficient Ni-based catalysts for selective hydrogenation of other biomass-derived compounds containing carboxylic group. [ABSTRACT FROM AUTHOR]

Tree canker diseases are mainly caused by necrotrophic fungal pathogens, which induce canker lesions, wilting, or dieback in many species. We hypothesized that canker-associated canopy dieback is related to functional failure of the phloem and cambium, carbon starvation and/or hydraulic failure. Using a girdling and inoculation system, we evaluated gas exchange and hydraulic parameters, concentrations of non-structural carbohydrates (NSCs), leaf characteristics, stem phenotyping and symptoms of 6-month-old poplar saplings with Botryosphaeria or Valsa canker disease. Pathogen inoculations inhibited callus formation and phloem regeneration and altered the physiological parameters, water potential, NSC content in stems, and symptoms on leaves and stems, while the girdling-only control did not. Results suggest that the functional and structural integrity of the phloem and cambium play crucial roles in the pathogenesis of canker disease. Botryosphaeria canker decreased photosynthetic rate (−54% to −75%), stomatal conductance (−71% to −80%) and transpiration rate (−58% to −66%), while Valsa canker decreased photosynthetic rate (−53% to −83%), stomatal conductance (−71% to −87%) and transpiration rate (−53% to −76%) at 20, 25, and 30 days after inoculation. Results suggest that the two fungal pathogens induce carbon starvation by inhibiting photosynthesis. The leaf water potential was higher and the change in specific hydraulic conductivity was smaller in the canker region than in the adjacent regions, while the NSC content was lower in the region below cankers than above them, suggesting that the fungal pathogens caused poplar canopy dieback by initially inducing carbon starvation, not hydraulic failure. • A novel girdling-inoculation method was used to reveal the physiology of poplar Botryosphaeria dothidea and Valsa sordida diseases. • The functional integrity of phloem and cambium plays crucial roles in the development of cankers. • Pathogens B. dothidea and V. sordida induce carbon starvation by inhibiting photosynthesis. • The development of cankers initially due to carbon starvation, not hydraulic failure, in the early stage of diseases. • Pathogens change the path of water movement, suggesting an inhibition of water conductivity in the late stage of poplar canker diseases. [ABSTRACT FROM AUTHOR]