Solution Blow Spinning of the Benzimidazole-Containing Aramid Nanofibers for Separators of Lithium-Ion Batteries.

Nanofibers based on high-performance polymers are much highlighted in recent studies toward advanced lithium-ion batteries. Herein, we demonstrate one scalable poly(ethylene oxide) (PEO)-assisted solution blow spinning strategy for the preparation of heterocyclic aramid (HA) nanofibers of poly(p-phenylene-benzimidazole-terephthalamide). The incorporation of PEO is essential to improve the spinnability of the HA solution achieved directly through the low-temperature-solution copolymerization process. Additionally, the flexible PEO with a strong H-bonding affinity is also utilized as the molecular zipper to adjust the pore size of the nanofiber membrane during the post-treatment process. The obtained membrane combines the good wettability of PEO to the liquid electrolytes, with outstanding mechanical strength, modulus, toughness, and environmental resistance of HA. The nonwoven separator membranes with a porosity of 83.6% exhibited excellent comprehensive performance, which could be seen not only on the high tensile strength (68.2 MPa), modulus (3.0 GPa), and toughness but also on the high thermal stability (Td > 405 °C) and flame retardancy, as well as the high electrolyte uptake (302.4%). The ion conductivity of the porous separators reached 0.83 mS/cm, with the bulk resistance dropping to 1/4 of the reference polypropylene separator. In the assembly of the Li/LiFePO4 half battery, the HA separators displayed improved discharge specific capacity and high retention in both rate capability and cycling tests, providing the potential industrial preparation for advanced lithium-ion batteries.

Communication-Efficient Accurate Statistical Estimation.

When the data are stored in a distributed manner, direct applications of traditional statistical inference procedures are often prohibitive due to communication costs and privacy concerns. This paper develops and investigates two Communication-Efficient Accurate Statistical Estimators (CEASE), implemented through iterative algorithms for distributed optimization. In each iteration, node machines carry out computation in parallel and communicate with the central processor, which then broadcasts aggregated information to node machines for new updates. The algorithms adapt to the similarity among loss functions on node machines, and converge rapidly when each node machine has large enough sample size. Moreover, they do not require good initialization and enjoy linear converge guarantees under general conditions. The contraction rate of optimization errors is presented explicitly, with dependence on the local sample size unveiled. In addition, the improved statistical accuracy per iteration is derived. By regarding the proposed method as a multi-step statistical estimator, we show that statistical efficiency can be achieved in finite steps in typical statistical applications. In addition, we give the conditions under which the one-step CEASE estimator is statistically efficient. Extensive numerical experiments on both synthetic and real data validate the theoretical results and demonstrate the superior performance of our algorithms.

First Report of Banana mild mosaic virus Infecting Banana in China.

Banana (Musa spp.) is an important fruit in tropical and subtropical regions and an essential food crop in some developing countries. China has a long history of banana cultivation and ranks second in global banana production, with a planting area exceeding 11 million hectares (FAOSTAT, 2023). Banana mild mosaic virus (BanMMV) is a flexuous filamentous virus infecting bananas and a banmivirus in the Betaflexiviridae family. Its infection often results in symptomless plants of Musa spp., and the virus has a worldwide distribution, which can explain its high prevalence (Kumar et al., 2015). BanMMV infection often causes transitory symptoms, such as mild chlorotic streaks and mosaics, on young leaves (Thomas, 2015). The mixed infection of BanMMV with other banana-infecting viruses such as banana streak viruses (BSV) and cucumber mosaic virus (CMV), can exacerbate the mosaic symptoms of BanMMV (Fidan et al., 2019). In October 2021, we collected twenty-six leaf samples of suspected viral disease of bananas from four cities (Huizhou, Qingyuan, Zhanjiang, and Yangjiang) in Guangdong province, two cities (Hekou and Jinghong) in Yunnan province, two cities (Yulin and Wuming) in Guangxi Zhuang autonomous region. After fully mixing these infected samples, we divided them into two pools and sent them to Shanghai Biotechnology Corporation (China) for metatranscriptome sequencing. Each sample contained about 5 g of leaves in total. Zymo-Seq RiboFree Total RNA Library Prep Kit (Zymo Research, USA) was used for ribosomal RNA depletion and library preparations. Illumina sequencing (Illumina NovaSeq 6000) was carried out by Shanghai Biotechnology Corporation (China). Paired-end (150 bp) sequencing of the RNA library was performed on an Illumina HiSeq 2000/2500 platform. Clean reads were assembled by a metagenomic de novo assembly using the CLC Genomics Workbench (version: 6.0.4). Then the non-redundant protein database in the National Center for Biotechnology Information (NCBI) was used for BLASTx annotation. A total of 79,528 contigs were generated from the clean reads (68,878,162) through de novo assembly. A contig of 7265 nucleotides (nts) showed the highest nucleotide sequence identity (90.08%) to the genome of BanMMV isolate EM4-2 (GenBank accession no. OL826745.1). We designed specific primers according to the BanMMV CP gene (Table S1), tested the twenty-six leaf samples collected from the above-mentioned eight cities, and found that only one sample of Fenjiao (Musa ABB Pisang Awak) in Guangzhou city was infected with this virus. The symptoms of banana leaves containing BanMMV were slight chlorosis and yellowing of leaf edges (Fig. S1). We failed to detect other banana viruses, such as BSV, CMV, and banana bunchy top virus (BBTV) in the BanMMV-infected banana leaves. RNA from the infected leaves was extracted, and the assembled contig was confirmed by overlapping PCR amplification across the whole sequence (Table S1). All ambiguous regions were amplified by PCR and RACE, and the products were subjected to Sanger sequencing. The complete genome of the virus candidate was 7310 nts in length, excluding the poly (A) tail. The sequence was deposited in GenBank under accession number ON227268 (isolate BanMMV-GZ from Guangzhou). A schematic representation of the genome organization of BanMMV-GZ is shown in Fig. S2. Its genome has five open reading frames (ORF) encoding RNA-dependent RNA polymerase (RdRp), three triple gene block proteins necessary for cell-to-cell movement (TGBp1 to TGBp3) and a coat protein (CP), similar to other BanMMV isolates (Kondo et al., 2021). Phylogenetic analyses of the complete nt sequence of the full genome and RdRp gene using the neighbor-joining (NJ) method also clearly placed the BanMMV-GZ firmly within all isolates of BanMMV (Fig. S3). To our knowledge, this is the first report of BanMMV infecting bananas in China, extending the geographical range of this viral disease around the world. Accordingly, larger-scale BanMMV investigations must be conducted to determine the distribution and prevalence of BanMMV in China.

Recent Advances in Self-Assembly and Application of Para-Aramids.

Poly(p-phenylene terephthalamide) (PPTA) is one kind of lyotropic liquid crystal polymer. Kevlar fibers performed from PPTA are widely used in many fields due to their superior mechanical properties resulting from their highly oriented macromolecular structure. However, the "infusible and insoluble" characteristic of PPTA gives rise to its poor processability, which limits its scope of application. The strong interactions and orientation characteristic of aromatic amide segments make PPTA attractive in the field of self-assembly. Chemical derivation has proved an effective way to modify the molecular structure of PPTA to improve its solubility and amphiphilicity, which resulted in different liquid crystal behaviors or supramolecular aggregates, but the modification of PPTA is usually complex and difficult. Alternatively, higher-order all-PPTA structures have also been realized through the controllable hierarchical self-assembly of PPTA from the polymerization process to the formation of macroscopic products. This review briefly summarizes the self-assembly methods of PPTA-based materials in recent years, and focuses on the polymerization-induced PPTA nanofibers which can be further fabricated into different macroscopic architectures when other self-assembly methods are combined. This monomer-started hierarchical self-assembly strategy evokes the feasible processing of PPTA, and enriches the diversity of product, which is expected to be expanded to other liquid crystal polymers.

Adaptive Huber Regression on Markov-dependent Data.

High-dimensional linear regression has been intensively studied in the community of statistics in the last two decades. For the convenience of theoretical analyses, classical methods usually assume independent observations and sub-Gaussian-tailed errors. However, neither of them hold in many real high-dimensional time-series data. Recently [Sun, Zhou, Fan, 2019, J. Amer. Stat. Assoc., in press] proposed Adaptive Huber Regression (AHR) to address the issue of heavy-tailed errors. They discover that the robustification parameter of the Huber loss should adapt to the sample size, the dimensionality, and the moments of the heavy-tailed errors. We progress in a vertical direction and justify AHR on dependent observations. Specifically, we consider an important dependence structure - Markov dependence. Our results show that the Markov dependence impacts on the adaption of the robustification parameter and the estimation of regression coefficients in the way that the sample size should be discounted by a factor depending on the spectral gap of the underlying Markov chain.

First Report of Tobacco Mosaic Virus Infecting Papaya in China.

Papaya (Carica papaya. L) is widely cultivated in tropical and subtropical regions of China and has high nutritional and medicinal values. More than 11 species of papaya viruses have been recorded in the world, but the most destructive one for papaya production in China is papaya ringspot virus (PRSV) (Li, 2019). In order to control PRSV, a transgenic papaya cultivar, designated as 'Huanong No.1', carrying the nuclear inclusion b (Nib) cistron of PRSV Ys isolate, was successfully commercialized in 2006, and has shown a wide range of resistance to PRSV in China (Li et al. 2007). However, more than 10% of 'Huanong No.1' plants developed different virus-like symptoms on leaves, including mosaic, yellow mottle, and deformation in some plantations of Guangdong Province, China in 2020 (Suppl Figure 1a, b, and c). Based on observation of the symptomatic phenotypes, the field surveys indicated that the disease incidence ranged from 10% to 40%, resulting in significant loss of papaya fruit. The virus particles were purified from symptomatic papaya plants following Gooding and Hebert (1967) and rigid filamentous particles resembling tobacco mosaic virus (TMV) were observed by transmission electron microscopy. Purified virus samples were further utilized to mechanically inoculate healthy seedlings of papaya, Nicotiana glutinosa and N. tabacum K326. At 15 days after inoculation, the obvious symptoms of virus infection on different plants were observed. The diseased plants showed systemic mottling and mosaic in the papaya leaves (Suppl Figure 1d), necrotic spots on the leaves of N. glutinosa (Suppl Figure 1e), mosaic and mottling spots on leaves of N. tabacum K326 (Suppl Figure 1f). These symptoms produced on the hosts were exactly the same caused by TMV. In order to reconfirm the species of the infected virus, the total RNA was extracted from the single leaf of 30 diseased papaya plants using RNAiso Plus kit (Takara, Japan) and reverse transcription--polymerase chain reaction was performed using TMV coat protein cistron specific primers (TMV-CP-R: 5'-TCAAGTTGCAGGACCAGA-3' and TMV-CP-F 5'- ATGTCTTACAGTATCACTAC-3') as described previously (Srivastava et al. 2015). An expected 480-bp fragment was amplified from all of the samples. Sequence analysis revealed that the diseased papaya was infected with TMV, designated as Cpa-TMV. In order to understand the difference among TMV isolates on papaya and other host plants, the whole genomic sequence of TMV from papaya was obtained and analyzed. The total length of the genome of Cpa-TMV was 6395 bp, and the sequence was submitted to the NCBI database (GenBank no. OK149218). A neighbor-joining phylogenetic tree of 19 TMV isolates was constructed using MEGA X software. Phylogenetic analysis indicated that the 19 TMV isolates were divided into Clade I, II and III (Suppl Figure 2). Interestingly, Clade I was composed of 12 Chinese mainland isolates, which further was grouped into IA (Northern China) and IB (Southern China), while 6 isolates from other countries and 1 isolate (pet-TMV) from China Taiwan belong to Clade II and III. It is inferred that the TMV isolates from Chinese mainland are quite different from other countries and China Taiwan. This suggests that geographical differences between Northern and Southern China may lead to the gradual differentiation of TMV isolates and eventually induce those isolates to evolve into two subclades. To our knowledge, this is the first report of TMV infection on papaya under natural conditions. It is necessary to find effective methods to control TMV in transgenic papaya.

Comparative transcriptome analysis revealed resistance differences of Cavendish bananas to Fusarium oxysporum f.sp. cubense race1 and race4.

BACKGROUND: Banana Fusarium wilt is a devastating disease of bananas caused by Fusarium oxysporum f. sp. cubense (Foc) and is a serious threat to the global banana industry. Knowledge of the pathogenic molecular mechanism and interaction between the host and Foc is limited. RESULTS: In this study, we confirmed the changes of gene expression and pathways in the Cavendish banana variety 'Brazilian' during early infection with Foc1 and Foc4 by comparative transcriptomics analysis. 1862 and 226 differentially expressed genes (DEGs) were identified in 'Brazilian' roots at 48 h after inoculation with Foc1 and Foc4, respectively. After Foc1 infection, lignin and flavonoid synthesis pathways were enriched. Glucosinolates, alkaloid-like compounds and terpenoids were accumulated. Numerous hormonal- and receptor-like kinase (RLK) related genes were differentially expressed. However, after Foc4 infection, the changes in these pathways and gene expression were almost unaffected or weakly affected. Furthermore, the DEGs involved in biological stress-related pathways also significantly differed after infection within two Foc races. The DEGs participating in phenylpropanoid metabolism and cell wall modification were also differentially expressed. By measuring the expression patterns of genes associated with disease defense, we found that five genes that can cause hypersensitive cell death were up-regulated after Foc1 infection. Therefore, the immune responses of the plant may occur at this stage of infection. CONCLUSION: Results of this study contribute to the elucidation of the interaction between banana plants and Foc and to the development of measures to prevent banana Fusarium wilt.

Predictive factors of progression in renal function after unilateral nephrectomy in renal malignancy.

PURPOSE: This study aimed to investigate the predictors of renal function changes after unilateral nephrectomy in renal malignancy. METHODS: The clinical data from patients who were pathologically diagnosed with primary renal cancer with preoperative eGFR≥60 mL/min/1.73 m2 and had accepted the unilateral nephrectomy for renal malignant tumors were retrospectively analysed. General information and biochemical indicators of patients were collected before surgery. This study used multiple uni-factor and multi-factor correlation analyses to determine the correlation between postoperative eGFR and preoperative indicators. RESULTS: After a postoperative follow-up of 119 patients from 3 to 60 months, we found that among 31 factors, urine osmotic pressure and preoperative eGFR were significantly associated with postoperative renal function deterioration. Further analysis indicated that urinary osmotic pressure was an independent risk factor of renal function deterioration. There was a negative correlation between preoperative eGFR and postoperative renal function deterioration. Lymphocyte counts and preoperative eGFR had a significant impact on postoperative renal function deterioration. Urinary osmotic pressure and preoperative eGFR could be used to evaluate the postoperative renal function deterioration. CONCLUSIONS: The postoperative renal function deterioration of patients with renal cell carcinoma was closely related to urine osmotic pressure and preoperative eGFR. The indicators of lymphocyte counts and preoperative eGFR had a significant impact on the progression of patient renal dysfunction. Urine osmotic pressure and preoperative eGFR can be utilized as an evaluation index for postoperative renal function deterioration.