A prototype protein nanocage minimized from carboxysomes with gated oxygen permeability.

Protein nanocages (PNCs) in cells and viruses have inspired the development of self-assembling protein nanomaterials for various purposes. Despite the successful creation of artificial PNCs, the de novo design of PNCs with defined permeability remains challenging. Here, we report a prototype oxygen-impermeable PNC (OIPNC) assembled from the vertex protein of the ß-carboxysome shell, CcmL, with quantum dots as the template via interfacial engineering. The structure of the cage was solved at the atomic scale by combined solid-state NMR spectroscopy and cryoelectron microscopy, showing icosahedral assembly of CcmL pentamers with highly conserved interpentamer interfaces. Moreover, a gating mechanism was established by reversibly blocking the pores of the cage with molecular patches. Thus, the oxygen permeability, which was probed by an oxygen sensor inside the cage, can be completely controlled. The CcmL OIPNC represents a PNC platform for oxygen-sensitive or oxygen-responsive storage, catalysis, delivery, sensing, etc.

2023/24 mid-season influenza and Omicron XBB.1.5 vaccine effectiveness estimates from the Canadian Sentinel Practitioner Surveillance Network (SPSN).

The Canadian Sentinel Practitioner Surveillance Network reports mid-season 2023/24 influenza vaccine effectiveness (VE) of 63% (95% CI: 51-72) against influenza A(H1N1)pdm09, lower for clade 5a.2a.1 (56%; 95% CI: 33-71) than clade 5a.2a (67%; 95% CI: 48-80), and lowest against influenza A(H3N2) (40%; 95% CI: 5-61). The Omicron XBB.1.5 vaccine protected comparably well, with VE of 47% (95% CI: 21-65) against medically attended COVID-19, higher among people reporting a prior confirmed SARS-CoV-2 infection at 67% (95% CI: 28-85).

Transmission rate Optimization by dynamic resource allocation algorithm for RF/VLC heterogeneous networks.

In this work, a dynamic resource allocation (DRA) algorithm is proposed to optimize the transmission rate subject to the access point assignment, bandwidth and transmit power allocation in RF/VLC heterogeneous networks, which combines the visible light communication (VLC) access point (AP) and radio frequency (RF) AP. To optimize the allocation among resource block (RB), subchannel and power, the time-average transmission rate is maximized under time-average transmit power budget. Specifically, the time-average optimization problem is converted into series of single timeslot online problem by Lyapunov optimization technique. Because of its complexity and non-convexity, the problem is decomposed into three independent subproblems for which a non-iterative solution is presented on the basis of Lagrange relaxation and convex optimization theory. Numerical simulations are conducted to demonstrate the effectiveness of the proposed DRA algorithm. And the comparisons with two classical algorithms are also given in terms of transmission rate and system stability. This work will benefit the design and development of hybrid RF/VLC system.

Generation and characterization of self-assembled protein nanocages based on ß-carboxysomes in Escherichia coli.

Self-assembly is a powerful means to create new materials and new catalysts. The advantages of biological self-assembly are based on it being highly programmable and prone to multilevel regulation, which can lead to multiple and complex functions. The self-assembly of carboxysomes in cyanobacteria enables the carboxysomes to enrich carbon dioxide in their interior, resulting in the formation of a highly efficient, multiple-enzyme catalytic system. Here, we show that the construction and coexpression of all genes of the ß-carboxysome from the cyanobacterium Thermosynechococcus elongatus BP-1 can lead to the production of ß-carboxysome-like structures in Escherichia coli. These shell structures were characterized intracellularly and extracellularly by transmission electron microscopy. This work lays a foundation for understanding carboxysome assembly and catalysis and the development of novel carboxysome-based nanomaterials utilizing synthetic biology.

Fatigue-Resistant Interfacial Layer for Safe Lithium Metal Batteries.

The plating/stripping of Li dendrites can fracture the static solid electrolyte interphase (SEI) and cause significant dynamic volume variations in the Li anode, which give rise to poor cyclability and severe safety hazards. Herein, a tough polymer with a slide-ring structure was designed as a self-adaptive interfacial layer for Li anodes. The slide-ring polymer with a dynamically crosslinked network moves freely while maintaining its toughness and fracture resistance, which allows it can to dissipate the tension induced by Li dendrites on the interphase layer. Moreover, the slide-ring polymer is highly stretchable, elastic, and displays an ultrafast self-healing ability, which allows even pulverized Li to remain coalesced without disintegrating upon consecutive cycling. The Li anodes demonstrate greatly improved suppression of Li dendrite formation, as evidenced by the high critical current density (6 mA cm-2 ) and stable cycling for the full cells with high-areal capacity LiFePO4 , high-voltage NCM, and S cathodes.

Comparative genomic analysis of 142 bacteriophages infecting Salmonella enterica subsp. enterica.

BACKGROUND: Bacteriophages are bacterial parasites and are considered the most abundant and diverse biological entities on the planet. Previously we identified 154 prophages from 151 serovars of Salmonella enterica subsp. enterica. A detailed analysis of Salmonella prophage genomics is required given the influence of phages on their bacterial hosts and should provide a broader understanding of Salmonella biology and virulence and contribute to the practical applications of phages as vectors and antibacterial agents. RESULTS: Here we provide a comparative analysis of the full genome sequences of 142 prophages of Salmonella enterica subsp. enterica which is the full complement of the prophages that could be retrieved from public databases. We discovered extensive variation in genome sizes (ranging from 6.4 to 358.7 kb) and guanine plus cytosine (GC) content (ranging from 35.5 to 65.4%) and observed a linear correlation between the genome size and the number of open reading frames (ORFs). We used three approaches to compare the phage genomes. The NUCmer/MUMmer genome alignment tool was used to evaluate linkages and correlations based on nucleotide identity between genomes. Multiple sequence alignment was performed to calculate genome average nucleotide identity using the Kalgin program. Finally, genome synteny was explored using dot plot analysis. We found that 90 phage genome sequences grouped into 17 distinct clusters while the remaining 52 genomes showed no close relationships with the other phage genomes and are identified as singletons. We generated genome maps using nucleotide and amino acid sequences which allowed protein-coding genes to be sorted into phamilies (phams) using the Phamerator software. Out of 5796 total assigned phamilies, one phamily was observed to be dominant and was found in 49 prophages, or 34.5% of the 142 phages in our collection. A majority of the phamilies, 4330 out of 5796 (74.7%), occurred in just one prophage underscoring the high degree of diversity among Salmonella bacteriophages. CONCLUSIONS: Based on nucleotide and amino acid sequences, a high diversity was found among Salmonella bacteriophages which validate the use of prophage sequence analysis as a highly discriminatory subtyping tool for Salmonella. Thorough understanding of the conservation and variation of prophage genomic characteristics will facilitate their rational design and use as tools for bacterial strain construction, vector development and as anti-bacterial agents.

SPL13 regulates shoot branching and flowering time in Medicago sativa.

KEY MESSAGE: Our results show SPL13 plays a crucial role in regulating vegetative and reproductive development in Medicago sativa L. (alfalfa), and that MYB112 is targeted and downregulated by SPL13 in alfalfa. We previously showed that transgenic Medicago sativa (alfalfa) plants overexpressing microRNA156 (miR156) show a bushy phenotype, reduced internodal length, delayed flowering time, and enhanced biomass yield. In alfalfa, transcripts of seven SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) transcription factors, including SPL13, are targeted for cleavage by miR156. Thus, association of each target SPL gene to a trait or set of traits is essential for developing molecular markers for alfalfa breeding. In this study, we investigated SPL13 function using SPL13 overexpression and silenced alfalfa plants. Severe growth retardation, distorted branches and up-curled leaves were observed in miR156-impervious 35S::SPL13m over-expression plants. In contrast, more lateral branches and delayed flowering time were observed in SPL13 silenced plants. SPL13 transcripts were predominantly present in the plant meristems, indicating that SPL13 is involved in regulating shoot branch development. Accordingly, the shoot branching-related CAROTENOID CLEAVAGE DIOXYGENASE 8 gene was found to be significantly downregulated in SPL13 RNAi silencing plants. A R2R3-MYB gene MYB112 was also identified as being directly silenced by SPL13 based on Next Generation Sequencing-mediated transcriptome analysis and chromatin immunoprecipitation assays, suggesting that MYB112 may be involved in regulating alfalfa vegetative growth.

Gene editing by CRISPR/Cas9 in the obligatory outcrossing Medicago sativa.

MAIN CONCLUSION: The CRISPR/Cas9 technique was successfully used to edit the genome of the obligatory outcrossing plant species Medicago sativa L. (alfalfa). RNA-guided genome engineering using Clustered Regularly Interspersed Short Palindromic Repeats (CRISPR)/Cas9 technology enables a variety of applications in plants. Successful application and validation of the CRISPR technique in a multiplex genome, such as that of M. sativa (alfalfa) will ultimately lead to major advances in the improvement of this crop. We used CRISPR/Cas9 technique to mutate squamosa promoter binding protein like 9 (SPL9) gene in alfalfa. Because of the complex features of the alfalfa genome, we first used droplet digital PCR (ddPCR) for high-throughput screening of large populations of CRISPR-modified plants. Based on the results of genome editing rates obtained from the ddPCR screening, plants with relatively high rates were subjected to further analysis by restriction enzyme digestion/PCR amplification analyses. PCR products encompassing the respective small guided RNA target locus were then sub-cloned and sequenced to verify genome editing. In summary, we successfully applied the CRISPR/Cas9 technique to edit the SPL9 gene in a multiplex genome, providing some insights into opportunities to apply this technology in future alfalfa breeding. The overall efficiency in the polyploid alfalfa genome was lower compared to other less-complex plant genomes. Further refinement of the CRISPR technology system will thus be required for more efficient genome editing in this plant.

MsmiR156 affects global gene expression and promotes root regenerative capacity and nitrogen fixation activity in alfalfa.

MicroRNA156 (miR156) regulates a network of downstream genes to affect plant growth and development. We previously generated alfalfa (Medicago sativa) plants that overexpress homologous miR156 (MsmiR156OE), and identified three of its SPL target genes. These plants exhibited increased vegetative yield, delayed flowering and longer roots. In this study, we aimed to elucidate the effect of miR156 on the root system, including effect on nodulation and nitrogen fixation. We found that MsmiR156 overexpression increases root regeneration capacity in alfalfa, but with little effect on root biomass at the early stages of root development. MsmiR156 also promotes nitrogen fixation activity by upregulating expression of nitrogenase-related genes FixK, NifA and RpoH in roots inoculated with Sinorrhizobium meliloti. Furthermore, we conducted transcriptomics analysis of MsmiR156OE alfalfa roots and identified differentially expressed genes belonging to 132 different functional categories, including plant cell wall organization, peptidyl-hypusine synthesis, and response to water stress. Expression analysis also revealed miR156 effects on genes involved in nodulation, root development and phytohormone biosynthesis. The present findings suggest that miR156 regulates root development and nitrogen fixation activity. Taken together, these findings highlight the important role that miR156 may play as a tool in the biotechnological improvement of alfalfa, and potentially other crops.

Comparative transcriptome investigation of global gene expression changes caused by miR156 overexpression in Medicago sativa.

BACKGROUND: Medicago sativa (alfalfa) is a low-input forage and potential bioenergy crop, and improving its yield and quality has always been a focus of the alfalfa breeding industry. Transgenic alfalfa plants overexpressing a precursor of alfalfa microRNA156 (MsmiR156) were recently generated by our group. These plants (miR156OE) showed enhanced biomass yield, reduced internodal length, increased shoot branching and trichome density, and a delay in flowering time. Transcripts of three SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) genes (MsSPL6, MsSPL12, and MsSPL13) were found to be targeted for cleavage by MsmiR156 in alfalfa. RESULTS: To further illustrate the molecular mechanisms underlying the effects of miR156 in alfalfa, two miR156OE genotypes (A11a and A17) were subjected to Next Generation RNA Sequencing with Illumina HiSeq. More than 1.11 billion clean reads were obtained from our available sequenced samples. A total of 160,472 transcripts were generated using Trinity de novo assembly and 4,985 significantly differentially expressed genes were detected in miR156OE plants A11a and A17 using the Medicago truncatula genome as reference. A total of 17 genes (including upregulated, downregulated, and unchanged) were selected for quantitative real-time PCR (qRT-PCR) validation, which showed that gene expression levels were largely consistent between qRT-PCR and RNA-Seq data. In addition to the established SPL genes MsSPL6, MsSPL12 and MsSPL13, four new SPLs; MsSPL2, MsSPL3, MsSPL4 and MsSPL9 were also down-regulated significantly in both miR156OE plants. These seven SPL genes belong to genes phylogeny clades VI, IV, VIII, V and VII, which have been reported to be targeted by miR156 in Arabidopsis thaliana. The gene ontology terms characterized electron transporter, starch synthase activity, sucrose transport, sucrose-phosphate synthase activity, chitin binding, sexual reproduction, flavonoid biosynthesis and lignin catabolism correlate well to the phenotypes of miR156OE alfalfa plants. CONCLUSIONS: This is the first report of changes in global gene expression in response to miR156 overexpression in alfalfa. The discovered miR156-targeted SPL genes belonging to different clades indicate miR156 plays fundamental and multifunctional roles in regulating alfalfa plant development.

Hibiscus latent Fort Pierce virus in Brazil and synthesis of its biologically active full-length cDNA clone.

A Brazilian isolate of Hibiscus latent Fort Pierce virus (HLFPV-BR) was firstly found in a hibiscus plant in Limeira, SP, Brazil. RACE PCR was carried out to obtain the full-length sequences of HLFPV-BR which is 6453 nucleotides and has more than 99.15 % of complete genomic RNA nucleotide sequence identity with that of HLFPV Japanese isolate. The genomic structure of HLFPV-BR is similar to other tobamoviruses. It includes a 5' untranslated region (UTR), followed by open reading frames encoding for a 128-kDa protein and a 188-kDa readthrough protein, a 38-kDa movement protein, 18-kDa coat protein, and a 3' UTR. Interestingly, the unique feature of poly(A) tract is also found within its 3'-UTR. Furthermore, from the total RNA extracted from the local lesions of HLFPV-BR-infected Chenopodium quinoa leaves, a biologically active, full-length cDNA clone encompassing the genome of HLFPV-BR was amplified and placed adjacent to a T7 RNA polymerase promoter. The capped in vitro transcripts from the cloned cDNA were infectious when mechanically inoculated into C. quinoa and Nicotiana benthamiana plants. This is the first report of the presence of an isolate of HLFPV in Brazil and the successful synthesis of a biologically active HLFPV-BR full-length cDNA clone.

Upregulation of LINC-AP2 is negatively correlated with AP2 gene expression with Turnip crinkle virus infection in Arabidopsis thaliana.

KEY MESSAGE: A long intergenic noncoding RNA LINC - AP2 is upregulated and negatively correlated with AP2 gene expression with Turnip crinkle virus infection in Arabidopsis. Plant vegetative growth and floral reproductive structure were severely retarded and distorted in Turnip crinkle virus (TCV)-infected Arabidopsis thaliana. Compared to mock-inoculated plants, the stamen filaments were shorter in flowers of TCV-infected plants. However, TCV-infected plants can still produce normal seeds through artificial pollination, indicating both its pollen and stigma were biologically functional. From our high-throughput RNA-Seq transcriptome analysis, a floral structure-related APETALA2 (AP2) gene was found to be downregulated and its neighboring long intergenic noncoding RNAs (lincRNA), At4NC069370 (named LINC-AP2 in this study), were upregulated significantly in TCV-infected plants. This LINC-AP2 was further confirmed for its existence using 5'RACE technology. LINC-AP2 overexpression (LINC-AP2 OE) transgenic Arabidopsis plants were generated to compare with TCV-infected WT plants. TCV-infected LINC-AP2 OE plants which contained lower AP2 gene expression displayed more severe symptoms (including floral structure distortion) and higher TCV-CP gene transcript and coat protein levels. Furthermore, compared to TCV-infected WT plants, TCV-infected ap2 mutant plants failed to open their flower buds and displayed more severe viral symptoms. In conclusion, upregulation of LINC-AP2 is negatively correlated with AP2 gene expression with TCV infection in Arabidopsis.

mRNA Delivery Systems Based on Protein Nanocages: How Far Can We Go?

Messenger RNA (mRNA) therapeutics hold great potential in the prevention and treatment of many diseases owing to several unique advantages. Delivery of mRNA into target cells is a critical step in mRNA therapy. Efficient and safe delivery systems remain an urgent need. Here, we provide an overview of the current applications of protein nanocages (PNCs), which include different types of PNCs, such as viral capsids, nonviral PNCs, and artificial PNCs, in mRNA delivery. PNCs have the features of uniform size, controllable assembly, modifiable inner and outer surfaces, good biocompatibility, and biodegradability, making them ideal candidates for mRNA delivery. In this review, the properties, loading strategies, and delivery outcomes of each tested PNC are introduced. The challenges faced by PNC-based mRNA carriers are discussed. We also share our perspectives on possible strategies to address these challenges, emphasizing the opportunities brought by emerging technologies and disciplinary convergence.

Application of prophage sequence analysis to investigate a disease outbreak involving Salmonella Adjame, a rare serovar and implications for the population structure.

Introduction: Outbreak investigation of foodborne salmonellosis is hindered when the food source is contaminated by multiple strains of Salmonella, creating difficulties matching an incriminated organism recovered from patients with the specific strain in the suspect food. An outbreak of the rare Salmonella Adjame was caused by multiple strains of the organism as revealed by single-nucleotide polymorphism (SNP) variation. The use of highly discriminatory prophage analysis to characterize strains of Salmonella should enable a more precise strain characterization and aid the investigation of foodborne salmonellosis. Methods: We have carried out genomic analysis of S. Adjame strains recovered during the course of a recent outbreak and compared them with other strains of the organism (n = 38 strains), using SNPs to evaluate strain differences present in the core genome, and prophage sequence typing (PST) to evaluate the accessory genome. Phylogenetic analyses were performed using both total prophage content and conserved prophages. Results: The PST analysis of the S. Adjame isolates showed a high degree of strain heterogeneity. We observed small clusters made up of 2-6 isolates (n = 27) and singletons (n = 11) in stark contrast with the three clusters observed by SNP analysis. In total, we detected 24 prophages of which only four were highly prevalent, namely: Entero_p88 (36/38 strains), Salmon_SEN34 (35/38 strains), Burkho_phiE255 (33/38 strains) and Edward_GF (28/38 strains). Despite the marked strain diversity seen with prophage analysis, the distribution of the four most common prophages matched the clustering observed using core genome. Discussion: Mutations in the core and accessory genomes of S. Adjame have shed light on the evolutionary relationships among the Adjame strains and demonstrated a convergence of the variations observed in both fractions of the genome. We conclude that core and accessory genomes analyses should be adopted in foodborne bacteria outbreak investigations to provide a more accurate strain description and facilitate reliable matching of isolates from patients and incriminated food sources. The outcomes should translate to a better understanding of the microbial population structure and an 46 improved source attribution in foodborne illnesses.

Influence of genomic variations on glanders serodiagnostic antigens using integrative genomic and transcriptomic approaches.

Glanders is a highly contagious and life-threatening zoonotic disease caused by Burkholderia mallei (B. mallei). Without an effective vaccine or treatment, early diagnosis has been regarded as the most effective method to prevent glanders transmission. Currently, the diagnosis of glanders is heavily reliant on serological tests. However, given that markedly different host immune responses can be elicited by genetically different strains of the same bacterial species, infection by B. mallei, whose genome is unstable and plastic, may result in various immune responses. This variability can make the serodiagnosis of glanders challenging. Therefore, there is a need for a comprehensive understanding and assessment of how B. mallei genomic variations impact the appropriateness of specific target antigens for glanders serodiagnosis. In this study, we investigated how genomic variations in the B. mallei genome affect gene content (gene presence/absence) and expression, with a special focus on antigens used or potentially used in serodiagnosis. In all the genome sequences of B. mallei isolates available in NCBI's RefSeq database (accessed in July 2023) and in-house sequenced samples, extensive small and large variations were observed when compared to the type strain ATCC 23344. Further pan-genome analysis of those assemblies revealed variations of gene content among all available genomes of B. mallei. Specifically, differences in gene content ranging from 31 to 715 genes with an average of 334 gene presence-absence variations were found in strains with complete or chromosome-level genome assemblies, using the ATCC 23344 strain as a reference. The affected genes included some encoded proteins used as serodiagnostic antigens, which were lost due mainly to structural variations. Additionally, a transcriptomic analysis was performed using the type strain ATCC 23344 and strain Zagreb which has been widely utilized to produce glanders antigens. In total, 388 significant differentially expressed genes were identified between these two strains, including genes related to bacterial pathogenesis and virulence, some of which were associated with genomic variations, particularly structural variations. To our knowledge, this is the first comprehensive study to uncover the impacts of genetic variations of B. mallei on its gene content and expression. These differences would have significant impacts on host innate and adaptive immunity, including antibody production, during infection. This study provides novel insights into B. mallei genetic variants, knowledge which will help to improve glanders serodiagnosis.

Hibiscus chlorotic ringspot virus coat protein upregulates sulfur metabolism genes for enhanced pathogen defense.

In both Hibiscus chlorotic ringspot virus (HCRSV)-infected and HCRSV coat protein (CP) agroinfiltrated plant leaves, we showed that sulfur metabolism pathway related genes-namely, sulfite oxidase (SO), sulfite reductase, and adenosine 5'-phosphosulfate kinase-were upregulated. It led us to examine a plausible relationship between sulfur-enhanced resistance (SED) and HCRSV infection. We broadened an established method to include different concentrations of sulfur (0S, 1S, 2S, and 3S) to correlate them to symptom development of HCRSV-infected plants. We treated plants with glutathione and its inhibitor to verify the SED effect. Disease resistance was induced through elevated glutathione contents during HCRSV infection. The upregulation of SO was related to suppression of symptom development induced by sulfur treatment. In this study, we established that HCRSV-CP interacts with SO which, in turn, triggers SED and leads to enhanced plant resistance. Thus, we have discovered a new function of SO in the SED pathway. This is the first report to demonstrate that the interaction of a viral protein and host protein trigger SED in plants. It will be interesting if such interaction applies generally to other host-pathogen interactions that will lead to enhanced pathogen defense.

Application of a High-Throughput Targeted Sequence AmpliSeq Procedure to Assess the Presence and Variants of Virulence Genes in Salmonella.

We have developed a targeted, amplicon-based next-generation sequencing method to detect and analyze 227 virulence genes (VG) of Salmonella (AmpliSeqSalm_227VG) for assessing the pathogenicity potential of Salmonella. The procedure was developed using 80 reference genomes representing 75 epidemiologically-relevant serovars associated with human salmonellosis. We applied the AmpliSeqSalm_227VG assay to (a) 35 previously characterized field strains of Salmonella consisting of serovars commonly incriminated in foodborne illnesses and (b) 34 Salmonella strains with undisclosed serological or virulence attributes, and were able to divide Salmonella VGs into two groups: core VGs and variable VGs. The commonest serovars causing foodborne illnesses such as Enteritidis, Typhimurium, Heidelberg and Newport had a high number of VGs (217-227). In contrast, serovars of subspecies not commonly associated with human illnesses, such as houtenae, arizonae and salame, tended to have fewer VGs (177-195). Variable VGs were not only infrequent but, when present, displayed considerable sequence variation: safC, sseL, sseD, sseE, ssaK and stdB showed the highest variation and were linked to strain pathogenicity. In a chicken infection model, VGs belonging to rfb and sse operons showed differences and were linked with pathogenicity. The high-throughput, targeted NGS-based AmpliSeqSalm_227VG procedure provided previously unknown information about variation in select virulence genes that can now be applied to a much larger population of Salmonella for evaluating pathogenicity of various serovars of Salmonella and for risk assessment of foodborne salmonellosis.

Building a Self-Adaptive Protective Layer on Ni-Rich Layered Cathodes to Enhance the Cycle Stability of Lithium-Ion Batteries.

Layered Ni-rich lithium transition metal oxides are promising battery cathodes due to their high specific capacity, but their poor cycling stability due to intergranular cracks in secondary particles restricts their practical applications. Surface engineering is an effective strategy for improving a cathode's cycling stability, but most reported surface coatings cannot adapt to the dynamic volume changes of cathodes. Herein, a self-adaptive polymer (polyrotaxane-co-poly(acrylic acid)) interfacial layer is built on LiNi0.6 Co0.2 Mn0.2 O2 . The polymer layer with a slide-ring structure exhibits high toughness and can withstand the stress caused by particle volume changes, which can prevent the cracking of particles. In addition, the slide-ring polymer acts as a physicochemical barrier that suppresses surface side reactions and alleviates the dissolution of transition metallic ions, which ensures stable cycling performance. Thus, the as-prepared cathode shows significantly improved long-term cycling stability in situations in which cracks may easily occur, especially under high-rate, high-voltage, and high-temperature conditions.

Chemotaxis Toward Crude Oil by an Oil-Degrading Pseudomonas aeruginosa 6-1B Strain.

The chemotactic properties of an oil-degrading Pseudomonas aeruginosa strain 6-1B, isolated from Daqing Oilfield, China, have been investigated. The strain 6-1B could grow well in crude oil with a specific rhamnolipid biosurfactant production. Furthermore, it exhibits chemotaxis toward various substrates, including glycine, glycerol, glucose, and sucrose. Compared with another oil-degrading strain, T7-2, the strain 6-1B presented a better chemotactic response towards crude oil and its vital component, n-alkenes. Based on the observed distribution of the strain 6-1B cells around the oil droplet in the chemotactic assays, the potential chemotaxis process of bacteria toward crude oil could be summarized in the following steps: searching, moving and consuming.

Deep desulfurization of fuels using supported ionic liquid-polyoxometalate hybrid as catalyst: A comparison of different types of ionic liquids.

In this work, polyoxometalates-based monomer ionic liquid, dimer ionic liquid and polyionic liquid were designed and prepared. Then supported catalysts were synthesized by loading polyoxometalate derivatives on the surface of graphene oxide (GO). The catalysts before and after loading were characterized via many tests such as scanning electron microscope (SEM), infrared spectroscopy (IR), X-ray powder diffraction (XRD) and so on. The influences of ionic liquid type and carrier on desulfurization activity were carried out. The result shows that supported catalyst-based polyionic liquid (P[Vim]POM/GO) performed high activity and excellent recyclability in extraction-oxidation desulfurization (EODS) due to unique state of polyoxometalate and the support of graphene oxide. In addition, the possible mechanism of oxidation dibenzothiophene (DBT) with H2O2 was proposed according to the kinetic study and gas chromatography-mass spectrometer (GC-MS) result.