Dexamethasone-Loaded Lipid Calcium Phosphate Nanoparticles Treat Experimental Colitis by Regulating Macrophage Polarization in Inflammatory Sites.

Background: The M1/M2 polarization of intestinal macrophages exerts an essential function in the pathogenesis of ulcerative colitis (UC), which can be adjusted to alleviate the UC symptoms. Purpose: A kind of pH-sensitive lipid calcium phosphate core-shell nanoparticles (NPs), co-loading with dexamethasone (Dex) and its water-soluble salts, dexamethasone sodium phosphate (Dsp), was constructed to comprehensively regulate macrophages in different states towards the M2 phenotype to promote anti-inflammatory effects. Methods: Dex and Dsp were loaded in the outer lipid shell and inner lipid calcium phosphate (Cap) core of the LdCaPd NPs, respectively. Then, the morphology of NPs and methods for determining drug concentration were investigated, followed by in vitro protein adsorption, stability, and release tests. Cell experiments evaluated the cytotoxicity, cellular uptake, and macrophage polarization induction ability of NPs. The in vivo distribution and anti-inflammatory effect of NPs were evaluated through a 2,4,6-trinitrobenzene sulfonic acid (TNBS)-induced BALB/c mice ulcerative colitis model. Results: The LdCaPd NPs showed a particle size of about 200 nm and achieved considerable loading amounts of Dex and Dsp. The in vitro and in vivo studies revealed that in the acidic UC microenvironment, the cationic lipid shell of LdCaPd underwent protonated dissociation to release Dex first for creating a microenvironment conducive to M2 polarization. Then, the exposed CaP core was further engulfed by M1 macrophages to release Dsp to restrict the pro-inflammatory cytokines production by inhibiting the activation and function of the nuclear factor kappa-B (NF-κB) through activating the GC receptor and the NF kappa B inhibitor α (I-κBα), respectively, ultimately reversing the M1 polarization to promote the anti-inflammatory therapy. Conclusion: The LdCaPd NPs accomplished the sequential release of Dex and Dsp to the UC site and the inflammatory M1 macrophages at this site, promoting the regulation of macrophage polarization to accelerate the remission of UC symptoms.

Ultrasound-guided serratus anterior plane block to prevent neurocognitive impairment in elderly patients after thoracoscopic lobectomy: protocol for a single-centre, double-blind, randomised controlled trial.

INTRODUCTION: Postoperative neurocognitive dysfunction (PND), including postoperative delirium (POD), is a common complication in elderly patients after major surgeries, often leading to poor postoperative recovery. Although the pathological mechanism underlying PND is still unclear, postoperative pain is strongly associated with the development of PND. The ultrasound-guided serratus anterior plane block (SAPB) has been reported to relieve postoperative pain in thoracic surgery. Therefore, this prospective trial hypothesises that SAPB may reduce the incidence of PND in the elderly undergoing thoracoscopic lobectomy. METHODS AND ANALYSIS: This study is designed as a single-centre, double-blind, randomised controlled clinical trial. A total of 256 elderly patients scheduled to undergo thoracoscopic lobectomy at Shanghai Pulmonary Hospital will be randomly assigned to general anaesthesia group or SAPB group. The primary outcome is the incidence of PND 7 days postoperatively or before discharge from hospital. The secondary outcomes include the occurrence of POD, the postoperative pain scores, Quality of Recovery at 1-2 days postoperatively and incidence of PND at 3 months postoperatively. The levels of fasting blood glucose in peripheral blood will be examined before and 1-2 days postoperatively. ETHICS AND DISSEMINATION: The trial has been approved by the Clinical Research Ethics Committee of Shanghai Pulmonary Hospital (identifier: K20-290). All participants will be required to provide written informed consent before any protocol-specific procedures. Findings will be disseminated in a peer-reviewed journal and in national and/or international meetings to guide future practice. TRIAL REGISTRATION NUMBER: ChiCTR2100052633.

Reversible structural transformations and color-tunable emissions in organic manganese halides.

Herein, we for the first time report a reversible conversion between green-emissive [DMPZ]MnCl4 and red-emissive [DMPZ]4(MnCl6)(MnCl4)2·(H2O)2 (DMPZ = 1,4-dimethylpiperazine) using kinetic and thermodynamic controlling strategies. Significantly, the synchronous structural and emission transformations in single-component organic manganese halides with adjustable emission colors are highlighted.

Integrating massive RNA-seq data to elucidate transcriptome dynamics in Drosophila melanogaster.

The volume of ribonucleic acid (RNA)-seq data has increased exponentially, providing numerous new insights into various biological processes. However, due to significant practical challenges, such as data heterogeneity, it is still difficult to ensure the quality of these data when integrated. Although some quality control methods have been developed, sample consistency is rarely considered and these methods are susceptible to artificial factors. Here, we developed MassiveQC, an unsupervised machine learning-based approach, to automatically download and filter large-scale high-throughput data. In addition to the read quality used in other tools, MassiveQC also uses the alignment and expression quality as model features. Meanwhile, it is user-friendly since the cutoff is generated from self-reporting and is applicable to multimodal data. To explore its value, we applied MassiveQC to Drosophila RNA-seq data and generated a comprehensive transcriptome atlas across 28 tissues from embryogenesis to adulthood. We systematically characterized fly gene expression dynamics and found that genes with high expression dynamics were likely to be evolutionarily young and expressed at late developmental stages, exhibiting high nonsynonymous substitution rates and low phenotypic severity, and they were involved in simple regulatory programs. We also discovered that human and Drosophila had strong positive correlations in gene expression in orthologous organs, revealing the great potential of the Drosophila system for studying human development and disease.

CenhANCER: a comprehensive cancer enhancer database for primary tissues and cell lines.

Enhancers, which are key tumorigenic factors with wide applications for subtyping, diagnosis and treatment of cancer, are attracting increasing attention in the cancer research. However, systematic analysis of cancer enhancers poses a challenge due to the lack of integrative data resources, especially those from tumor primary tissues. To provide a comprehensive enhancer profile across cancer types, we developed a cancer enhancer database CenhANCER by curating public resources including all the public H3K27ac ChIP-Seq data from 805 primary tissue samples and 671 cell line samples across 41 cancer types. In total, 57 029 408 typical enhancers, 978 411 super-enhancers and 226 726 enriched transcription factors were identified. We annotated the super-enhancers with chromatin accessibility regions, cancer expression quantitative trait loci (eQTLs), genotype-tissue expression eQTLs and genome-wide association study risk single nucleotide polymorphisms (SNPs) for further functional analysis. The identified enhancers were highly consistent with accessible chromatin regions in the corresponding cancer types, and all the 10 super-enhancer regions identified from one colorectal cancer study were recapitulated in our CenhANCER, both of which testified the high quality of our data. CenhANCER with high-quality cancer enhancer candidates and transcription factors that are potential therapeutic targets across multiple cancer types provides a credible resource for single cancer analysis and for comparative studies of various cancer types. Database URL http://cenhancer.chenzxlab.cn/.

Infliximab Inhibits Colitis Associated Cancer in Model Mice by Downregulating Genes Associated with Mast Cells and Decreasing Their Accumulation.

Inflammatory bowel diseases (IBDs), such as Crohn's disease or ulcerative colitis, can be treated with anti TNF-alpha (TNF-α) antibodies (Abs), but they also put patients with IBDs at risk of cancer. We aimed to determine whether the anti TNF-α Ab induces colon cancer development in vitro and in vivo, and to identify the genes involved in colitis-associated cancer. We found that TNF-α (50 ng/mL) inhibited the proliferation, migration, and invasion of HCT8 and COLO205 colon cancer cell lines and that anti TNF-α Ab neutralized TNF-α inhibition in vitro. The effects of anti TNF-α Ab, infliximab (10 mg/kg) were investigated in mouse models of colitis-associated cancer induced by intraperitoneally injected azoxymethane (AOM: 10 mg/kg)/orally administered dextran sodium sulfate (DSS: 2.5%) (AOM/DSS) in vivo. Infliximab significantly attenuated the development of colon cancer in these mice. Microarray analyses and RT-qPCR revealed that mast cell protease 1, mast cell protease 2, and chymase 1 were up-regulated in cancer tissue of AOM/DSS mice; however, those mast cell related genes were downregulated in cancer tissue of AOM/DSS mice with infliximab. These results suggested that mast cells play a pivotal role in the development of cancer associated with colitis in AOM/DSS mice.

BM-MSCs overexpressing the Numb enhance the therapeutic effect on cholestatic liver fibrosis by inhibiting the ductular reaction.

BACKGROUND: Cholestatic liver fibrosis (CLF) is caused by inflammatory destruction of the intrahepatic bile duct and abnormal proliferation of the small bile duct after cholestasis. Activation of the Notch signaling pathway is required for hepatic stem cells to differentiate into cholangiocytes during the pathogenesis of CLF. Our previous research found that the expression of the Numb protein, a negative regulator of Notch signaling, was significantly reduced in the livers of patients with primary biliary cholangitis and CLF rats. However, the relationship between the Numb gene and CLF is largely unclear. In this study, we investigated the role of the Numb gene in the treatment of bile duct ligation (BDL)-induced CLF. METHODS: In vivo, bone marrow-derived mesenchymal stem cells (BM-MSCs) with Numb gene overexpression or knockdown obtained using lentivirus transfection were transplanted into the livers of rats with BDL-induced CLF. The effects of the Numb gene on stem cell differentiation and CLF were evaluated by performing histology, tests of liver function, and measurements of liver hydroxyproline, cytokine gene and protein levels. In vitro, the Numb gene was overexpressed or knocked down in the WB-F344 cell line by lentivirus transfection, Then, cells were subjected immunofluorescence staining and the detection of mRNA levels of related factors, which provided further evidence supporting the results from in vivo experiments. RESULTS: BM-MSCs overexpressing the Numb gene differentiated into hepatocytes, thereby inhibiting CLF progression. Conversely, BM-MSCs with Numb knockdown differentiated into biliary epithelial cells (BECs), thereby promoting the ductular reaction (DR) and the progression of CLF. In addition, we confirmed that knockdown of Numb in sodium butyrate-treated WB-F344 cells aggravated WB-F344 cell differentiation into BECs, while overexpression of Numb inhibited this process. CONCLUSIONS: The transplantation of BM-MSCs overexpressing Numb may be a useful new treatment strategy for CLF.

Isorhynchophylline inhibits inflammatory responses in endothelial cells and macrophages through the NF-κB/NLRP3 signaling pathway.

BACKGROUND: Atherosclerosis is a chronic inflammatory disease of arterial wall, which is closely related to inflammatory reaction. In this study, the anti-inflammatory effect of isorhynchophylline was studied by NF- κB / NLRP3 pathway. METHODS: (1) ApoE-/- mice were fed with high-fat diet to establish atherosclerotic model, while C57 with the same genetic background was fed with common diet as control group. Body weight was recorded and blood lipids were detected. The expression of NLRP3, NF-κB, IL-18 and Caspase-1 in aorta was detected by Western-Blot and PCR, and plaque formation was detected by HE and oil red O staining. (2) Lipopolysaccharide interfered with Human Umbilical Vein Endothelial Cells (HUVECs) and RAW264.7 to form inflammatory model, and was treated with isorhynchophylline. The expression of NLRP3, NF-κB, IL-18 and Caspase-1 in aorta was detected by Western-Blot and PCR, and the ability of cell migration was detected by Transwell and scratch test. RESULTS: (1) the expression of NLRP3, NF- κB, IL-18 and Caspase-1 in aorta of model group was higher than that of control group, and plaque formation was obvious. (2) the expressions of NLRP3, NF- κB, IL-18 and Caspase-1 in HUVECs and RAW264.7 model groups were higher than those in control group, while isorhynchophylline decreased their expression and enhanced cell migration ability. CONCLUSION: Isorhynchophylline can reduce the inflammatory reaction induced by lipopolysaccharide and promote the ability of cell migration.

Organosulfur Materials for Rechargeable Batteries: Structure, Mechanism, and Application.

Lithium-ion batteries have received significant attention over the last decades due to the wide application of portable electronics and increasing deployment of electric vehicles. In order to further enhance the performance of the batteries and overcome the capacity limitations of inorganic electrode materials, it is imperative to explore new cathode and functional materials for rechargeable lithium batteries. Organosulfur materials containing sulfur-sulfur bonds as a kind of promising organic electrode materials have the advantages of high capacities, abundant resources, tunable structures, and environmental benignity. In addition, organosulfur materials have been widely used in almost every aspect of rechargeable batteries because of their multiple functionalities. This review aims to provide a comprehensive overview on the development of organosulfur materials including the synthesis and application as cathode materials, electrolyte additives, electrolytes, binders, active materials in lithium redox flow batteries, and other metal battery systems. We also give an in-depth analysis of structure-property-performance relationship of organosulfur materials, and guidance for the future development of organosulfur materials for next generation rechargeable lithium batteries and beyond.

Mucoadhesive Nanoparticles Enhance the Therapeutic Effect of Dexamethasone on Experimental Ulcerative Colitis by the Local Administration as an Enema.

Background: As the first-line drug to treat ulcerative colitis (UC), long-term use of glucocorticoids (GCs) produces severe toxic and side effects. Local administration as enema can increase the local GCs concentrations and reduce systemic exposure to high oral doses by directly delivering GCs to the inflammation site in the distal colorectum. However, UC patients are often accompanied by diarrhea, leading to the short colonic residence time of GCs and failure to exert their function fully. Purpose: A kind of mucoadhesive nanoparticles (NPs) loading different dexamethasone derivatives (DDs) were developed, which could attach to the positively charged inflammatory colonic mucosa through electrostatic adsorption after administered by enema, thereby improving the local concentration and achieving effective targeted therapy for UC. Methods: Two DDs, dexamethasone hemisuccinate and dexamethasone phosphate, were synthesized. In NPs preparation, The core PEI-DDs NPs were built by the electrostatic adsorption of DDs and the cationic polymer polyethyleneimine (PEI). Then, the natural polyanionic polysaccharide sodium alginate (SA) was electronically coated around NPs to construct the final SA-PEI-DDs NPs, followed by the in vitro stability and release tests, in vitro and in vivo colonic mucosal adhesion tests. In the in vivo anti-UC test, the experimental colitis mice were induced by 2,4,6-trinitrobenzenesulfonic acid. The body weight and disease activity index changes were measured, and the myeloperoxidase activity, pro-inflammatory cytokines concentration, and hematoxylin and eosin staining were also investigated to evaluate the therapeutic effect of NPs. Results: The structures of two DDs were demonstrated by 1H-NMR and MS. Both NPs were negatively charged and achieved high loading efficiency of DDs, while their particle sizes were significantly different. NPs showed good stability and sustained release properties in the simulated colonic environment. Moreover, the negative charge on the of NPs surface made them easier to adhere to the positively charged inflammatory colonic mucosa, thereby enhancing the enrichment and retention of DDS in the colitis site. Furthermore, the NPs exhibited better therapeutic effects than free Dex on the experimental colitis mice induced by TNBS through the enema rectal. Conclusion: These results indicated the mucoadhesive NPs as a kind of novel nano-enema showed great potential to achieve efficient treatment on UC.

[Applied anatomy of the stylomastoid foramina and its relation to the surrounding bone structures].

PURPOSE: To study the relationship between the stylomastoid foramen and surrounding bony structures, enrich anatomical data and provide reference for clinical surgery. METHODS: A total of 62 intact and dry adult skulls were selected. The shape of the stylomastoid foramen was observed, the diameter of the stylomastoid foramen, the distances from the posterolateral point and the anterior medial point to the surrounding bony structures were measured with a vernier caliper. SPSS 25.0 software package was used to analyze the data. RESULTS: There were four shapes of stylomastoid foramen, i.e., circular (61.29%), oval (29.84%), irregular (8.06%) and triangular (0.81%). The circular diameter was (2.80±0.61) mm, the oval long and short diameters were (4.43±0.96) and (2.79±0.60) mm. Distances from the posterolateral and anterior medial points of the stylomastoid foramen to the posterolateral point of the external opening of the carotid canal, the anterior medial point of the jugular foramen, the midline, the most anterior point of the foramen magnum, the posterior point of the great palatine foramen, the posterolateral point of the foramen lacerated, the foramen ovale, the posterolateral point of the foramen spinosum, the anterior point of the styloid process root, the outermost point of the tympanomastoid fissure and the tip of the mastoid process were (16.10±2.81), (24.01±2.65), (44.95±3.24), (45.10±2.71), (61.66±4.14), (35.56±4.35), (32.26±2.85), (29.12±3.40), (10.39±3.25), (9.49±2.24) and (12.01±2.79) mm; (12.80±2.41), (21.56±2.51), (42.96±3.97), (42.91±2.76), (58.97±3.97), (32.98±4.14), (29.20±2.77), (25.80±2.87), (7.37±2.33), (11.42±2.00) and (15.41±2.57) mm, respectively. Statistical analysis showed that there was no significant difference in the apertures and distances between the left and right side(P＞0.05). CONCLUSIONS: Most of the stylomastoid foramen are round and oval, understanding the distance between the foramen and surrounding bony structures is helpful for guiding clinical operations and enriching anatomical knowledge.

Sexually Dimorphic Gene Expression in X and Y Sperms Instructs Sexual Dimorphism of Embryonic Genome Activation in Yellow Catfish (Pelteobagrus fulvidraco).

Paternal factors play an important role in embryonic morphogenesis and contribute to sexual dimorphism in development. To assess the effect of paternal DNA on sexual dimorphism of embryonic genome activation, we compared X and Y sperm and different sexes of embryos before sex determination. Through transcriptome sequencing (RNA-seq) and whole-genome bisulfite sequencing (WGBS) of X and Y sperm, we found a big proportion of upregulated genes in Y sperm, supported by the observation that genome-wide DNA methylation level is slightly lower than in X sperm. Cytokine-cytokine receptor interaction, TGF-beta, and toll-like receptor pathways play important roles in spermatogenesis. Through whole-genome re-sequencing (WGRS) of parental fish and RNA-seq of five early embryonic stages, we found the low-blastocyst time point is a key to maternal transcriptome degradation and zygotic genome activation. Generally, sexual differences emerged from the bud stage. Moreover, through integrated analysis of paternal SNPs and gene expression, we evaluated the influence of paternal inheritance on sexual dimorphism of genome activation. Besides, we screened out gata6 and ddx5 as potential instructors for early sex determination and gonad development in yellow catfish. This work is meaningful for revealing the molecular mechanisms of sex determination and sexual dimorphism of fish species.

The effect of the nucleotides immediately upstream of the AUG start codon on the efficiency of translation initiation in sperm cells.

It is widely known that an optimal nucleotide sequence context immediately upstream of the AUG start codon greatly improves the efficiency of translation initiation of mRNA in mammalian and plant somatic cells, which in turn increases protein levels. However, it is still unclear whether a similar regulatory mechanism is also present in highly differentiated cells. Here, we surveyed this issue in Arabidopsis thaliana sperm cells and found that the sequence context-mediated regulation of translation initiation in sperm cells is generally similar to that in somatic cells. A simple motif of four adenine nucleotides at positions - 1 to - 4 greatly improved the efficiency of translation initiation, and when the motif was present there, translation was even initiated at some non-AUG codons in sperm cells. However, unlike that in mammalian cells, a mainly effective nucleotide site to regulate the efficiency of translation initiation was not present at positions - 1 to - 4 in sperm cells. Meanwhile, different from somatic cells, sperm cells did not use eukaryotic translation initiation factor 1 to regulate the efficiency in a poor context consisting of the lowest frequency nucleotides. All these results contribute to our understanding of the cytoplasmic event of translation initiation in highly differentiated sperm cells.

An intein-split transactivator for intersectional neural imaging and optogenetic manipulation.

The cell-type-specific recording and manipulation is instrumental to disentangle causal neural mechanisms in physiology and behavior and increasingly requires intersectional control; however, current approaches are largely limited by the number of intersectional features, incompatibility of common effectors and insufficient gene expression. Here, we utilized the protein-splicing technique mediated by intervening sequences (intein) and devised an intein-based intersectional synthesis of transactivator (IBIST) to selectively control gene expression of common effectors in multiple-feature defined cell types in mice. We validated the specificity and sufficiency of IBIST to control fluorophores, optogenetic opsins and Ca2+ indicators in various intersectional conditions. The IBIST-based Ca2+ imaging showed that the IBIST can intersect five features and that hippocampal neurons tune differently to distinct emotional stimuli depending on the pattern of projection targets. Collectively, the IBIST multiplexes the capability to intersect cell-type features and controls common effectors to effectively regulate gene expression, monitor and manipulate neural activities.

In vitro study on non-thermal argon plasma in improving the bonding efficacy between dentin and self-etch adhesive systems.

Self-etch adhesive systems have the advantages of simple operating steps and low technique sensitivity. However, some deficiencies of self-etch adhesive result that the immediate bonding strength between self-etch adhesive and dentine is not so high. Non-thermal atmospheric pressure plasma (NTAPP) can be used for surface modification. Previous studies of our research group have proven that NTAPP can improve bonding durability between dentine and etch-and-rinse adhesive. However, it is still unknown whether NTAPP can improve bonding strength between dentine and self-etch adhesive. The study observed the contact angle on dentine surface, the adhesive permeability and MTBS. The study proved that NTAPP can improve dentine surface wettability, clear up smear layer, and enhanced the self-etch adhesive permeability in dentine bonding interface. In conclusion, NTAPP could improve the bonding strength between dentine and self-etch adhesive systems. The most optimum treating time was 15 s.

Advances of Organosulfur Materials for Rechargeable Metal Batteries.

Battery materials have become a hotspot in the academic research. Organosulfur compounds are considered as a promising class of cathode materials for rechargeable metal batteries. They have attracted increasing attention in recent years after a long-term stagnancy since 1980s. Recent studies have focused on the understanding of redox mechanism of linear organosulfur molecules R-Sn -R with defined structures. In addition, some new organosulfur compounds are developed. The reversible sulfursulfur (SS) bond breakage/formation of organosulfur in batteries makes them applicable as functional materials in batteries. In this review, new organosulfur materials including molecules, polymers, and composites are introduced. In the following, organosulfur-inorganic hybrid materials are discussed, which have shown unique redox process and enhanced battery performance. In the third part, organosulfur additives are used in Li-S batteries, which can improve the formation of solid-electrolyte interphase (SEI) and alter the redox pathways of sulfur cathodes. In the fourth part, organosulfur materials used in other metal batteries are introduced. Lastly, a summary and some perspectives are given. This review presents an overview of the recent advances of organosulfur materials in batteries and provides guidance for the future development of these materials.

Tunable high acoustic impedance alumina epoxy composite matching for high frequency ultrasound transducer.

Matching layer is a critical component that determines the performance of piezoelectric ultrasound transducer. For most piezoelectric materials, their acoustic impedances are significantly higher than human tissues and organs, so a tunable matching layer with a high acoustic impedance is required for optimizing the acoustic wave transmission. In this article, a high compression fabrication method is presented, with which the acoustic impedance of alumina-epoxy composite matching layer can be tuned from 6.50 to 9.47 MRayl by controlling the applied compression pressure and ratio of the components. The maximum acoustic impedance 9.47 MRayl can be achieved by compressing a mixture of 80% alumina weight ratio under a 62.4 MPa pressure. This enhancement mainly relies on the increased acoustic longitudinal velocity which enlarged the tolerance of high to ultra-high frequency transducer fabrication using quarter wavelength matching design. Furthermore, the attenuation of the matching layer developed by this method is only -10 dB/mm at 40 MHz. The very high acoustic impedance value and very low attenuation make this matching material superior than all reported matching materials, and therefore, can enhance the performance of the ultrasound transducers, especially for medical imaging applications.

A competitive PCR-based method to detect a single copy of T-DNA insertion in transformants.

Gene function studies benefit from the availability of mutants. In plants, Agrobacterium-mediated genetic transformation is widely used to create mutants. These mutants, also called transformants, contain one or several transfer-DNA (T-DNA) copies in the host genome. Quantifying the copy number of T-DNA in transformants is beneficial to assess the number of mutated genes. Here, we developed a competitive polymerase chain reaction (PCR)-based method to detect a single copy of a T-DNA insertion in transformants. The competitor line BHK- -1 that contains a single copy of competitor BHK- (BHK, Basta, Hygromycin, Kanamycin-resistant genes) was crossed with test transformants and the genomic DNA of F1 plants was subjected to competitive PCR. By analyzing the gray ratio between two PCR products, we were able to determine whether or not the test transformants contained a single copy of T-DNA insertion. We also generated the control lines BHK±1:1 and BHK±2:1 , which contain the target (BHK+ ) and competitor (BHK- ) in a ratio of 1:1 and 2:1, respectively. The ratios of their PCR products are useful references for quantitative analysis. Overall, this method is reliable and simple in experimental manipulations and can be used as a substitute for Southern-blot analysis to identify a single copy of T-DNA insertion in transformants.

Electrosynthesis of 1,4-bis(diphenylphosphanyl) tetrasulfide via sulfur radical addition as cathode material for rechargeable lithium battery.

Organic electrodes are promising as next generation energy storage materials originating from their enormous chemical diversity and electrochemical specificity. Although organic synthesis methods have been extended to a broad range, facile and selective methods are still needed to expose the corners of chemical space. Herein, we report the organopolysulfide, 1,4-bis(diphenylphosphanyl)tetrasulfide, which is synthesized by electrochemical oxidation of diphenyl dithiophosphinic acid featuring the cleavage of a P-S single bond and a sulfur radical addition reaction. Density functional theory proves that the external electric field triggers the intramolecular rearrangement of diphenyl dithiophosphinic acid through dehydrogenation and sulfur migration along the P-S bond axis. Impressively, the Li/bis(diphenylphosphanyl)tetrasulfide cell exhibits the high discharge voltage of 2.9 V and stable cycling performance of 500 cycles with the capacity retention of 74.8%. Detailed characterizations confirm the reversible lithiation/delithiation process. This work demonstrates that electrochemical synthesis offers the approach for the preparation of advanced functional materials.

Nuclear DNA replicates during zygote development in Arabidopsis and Torenia fournieri.

The progression of the cell cycle is continuous in most cells, but gametes (sperm and egg cells) exhibit an arrest of the cell cycle to await fertilization to form a zygote, which then continues through the subsequent phases to complete cell division. The phase in which gametes of flowering plants arrest has been a matter of debate, since different phases have been reported for the gametes of different species. In this study, we reassessed the phase of cell-cycle arrest in the gametes of two species, Arabidopsis (Arabidopsis thaliana) and Torenia fournieri. We first showed that 4', 6-diamidino-2-phenylindole staining was not feasible to detect changes in gametic nuclear DNA in T. fournieri. Next, using 5-ethynyl-2'-deoxyuridine (EdU) staining that detects DNA replication by labeling the EdU absorbed by deoxyribonucleic acid, we found that the replication of nuclear DNA did not occur during gamete development but during zygote development, revealing that the gametes of these species have a haploid nuclear DNA content before fertilization. We thus propose that gametes in the G1 phase participate in the fertilization event in Arabidopsis and T. fournieri.