Pd-Catalyzed Deacylative [4 + 1] Annulation of N-Arylimidoyl Chlorides with ß-Keto Esters Leading to 2-Fluoroalkyl Indoles.

A palladium-catalyzed [4 + 1] annulation of N-arylimidoyl chlorides with ß-keto esters has been developed. In the presence of Pd(OAc)2, PCy3, and K3PO4, a variety of fluoalkyl-containing N-arylimidoyl chlorides smoothly underwent the cascade C-H imidoylation/deacylative Heck-type reactions to afford biologically important 2-fluoroalkyl indoles in moderate to good yields.

GGNBP2 regulates histone ubiquitination and methylation in spermatogenesis.

Gametogenetin binding protein 2 (GGNBP2) was indispensable in normal spermatids for transformation into mature spermatozoa in mice, and when Gametogenetin binding protein 2 is bound to BRCC36 and RAD51, the complex participates in repairing DNA double-strand breaks (DSB) during the meiotic progression of spermatocytes. Ggnbp2 knockout resulted in the up-regulation of H2AK119ubi and down-regulation of H2BK120ubi in GC-2 cells (mouse spermatogonia-derived cell line) and postnatal day 18 testis lysate. Our results also demonstrated that Gametogenetin binding protein 2 inducedASXL1 to activate the deubiquitinating enzyme BAP1 in deubiquitinating H2A, while Gametogenetin binding protein 2 knockout disrupted the interaction between ASXL1 and BAP1, resulting in BAP1 localization change. Furthermore, the Gametogenetin binding protein 2 deletion reduced H2B ubiquitination by affecting E2 enzymes and E3 ligase binding. Gametogenetin binding protein 2 regulated H2A and H2B ubiquitination levels and controlled H3K27 and H3K79 methylation by PRC2 subunits and histone H3K79 methyltransferase. Altogether, our results suggest that Ggnbp2 knockout increased DNA damage response by promoting H2A ubiquitination and H3K27trimethylation (H3K27me3) and reduced nucleosome stability by decreasing H2B ubiquitination and H3K79 dimethylation (H3K79me2), revealing new mechanisms of epigenetic phenomenon during spermatogenesis. Gametogenetin binding protein 2 seems critical in regulating histone modification and chromatin structure in spermatogenesis.

The SPARC-related modular calcium binding 1 (Smoc1) regulated by androgen is required for mouse gubernaculum development and testicular descent.

ABSTRACT: Testicular descent occurs in two consecutive stages: the transabdominal stage and the inguinoscrotal stage. Androgens play a crucial role in the second stage by influencing the development of the gubernaculum, a structure that pulls the testis into the scrotum. However, the mechanisms of androgen actions underlying many of the processes associated with gubernaculum development have not been fully elucidated. To identify the androgen-regulated genes, we conducted large-scale gene expression analyses on the gubernaculum harvested from luteinizing hormone/choriogonadotropin receptor knockout (Lhcgr KO) mice, an animal model of inguinoscrotal testis maldescent resulting from androgen deficiency. We found that the expression of secreted protein acidic and rich in cysteine (SPARC)-related modular calcium binding 1 (Smoc1) was the most severely suppressed at both the transcript and protein levels, while its expression was the most dramatically induced by testosterone administration in the gubernacula of Lhcgr KO mice. The upregulation of Smoc1 expression by testosterone was curtailed by the addition of an androgen receptor antagonist, flutamide. In addition, in vitro studies demonstrated that SMOC1 modestly but significantly promoted the proliferation of gubernacular cells. In the cultures of myogenic differentiation medium, both testosterone and SMOC1 enhanced the expression of myogenic regulatory factors such as paired box 7 (Pax7) and myogenic factor 5 (Myf5). After short-interfering RNA-mediated knocking down of Smoc1, the expression of Pax7 and Myf5 diminished, and testosterone alone did not recover, but additional SMOC1 did. These observations indicate that SMOC1 is pivotal in mediating androgen action to regulate gubernaculum development during inguinoscrotal testicular descent.

CaF2 nanoparticles enabling LiF-dominated solid electrolyte interphase for dendrite-free and ultra-stable lithium metal batteries.

The uncontrollable growth of Li dendrites and severe interfacial parasitic reactions on the Li anode are the primary obstacles to the practical application of lithium (Li) metal batteries. Effective artificial solid electrolyte interphase is capable of regulating uniform Li deposition and isolateing Li from electrolyte, thereby eliminating parasitic reactions. Herein, we rationally design a uniform LiF-dominated solid electrolyte interphase through an in-situ reaction between CaF2 nanoparticles and the Li anode, which allows dendrite-free Li deposition and restrains interfacial deterioration. Accordingly, the protective Li electrode demonstrated exceptional stability, sustaining over 6000 h at a current density of 2 mA cm-2 in symmetric cells and attaining over 1000 cycles with a low capacity decay rate of 0.015 % per cycle in coupling with LiFePO4 cathodes.

Sphingobacterium tenebrionis sp. nov., isolated from intestine of mealworm.

A bacterial strain designated PU5-4T was isolated from the mealworm (the larvae of Tenebrio molitor) intestines. It was identified to be Gram-stain-negative, strictly aerobic, rod-shaped, non-motile, and non-spore-forming. Strain PU5-4T was observed to grow at 10-40 °C, at pH 7.0-10.0, and in the presence of 0-3.0 % (w/v) NaCl. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain PU5-4T should be assigned to the genus Sphingobacterium. The 16S rRNA gene sequence similarity analysis showed that strain PU5-4T was closely related to the type strains of Sphingobacterium lactis DSM 22361T (98.49 %), Sphingobacterium endophyticum NYYP31T (98.11 %), Sphingobacterium soli NCCP 698T (97.69 %) and Sphingobacterium olei HAL-9T (95.73 %). The predominant isoprenoid quinone is MK-7. The major fatty acids were identified as iso-C15 : 0, iso-C17 : 03-OH and summed feature 3 (C16 : 1 ω7c and/or C16 : 1 ω6c) and summed feature 9 (iso-C17 : 0 ω9c). The polar lipids are phosphatidylethanolamine, one unidentified phospholipid, and six unidentified lipids. The genomic DNA G+C content of strain PU5-4T is 40.24 mol%. The average nucleotide identity of strain PU5-4T exhibited respective values of 73.88, 73.37, 73.36 and 70.84 % comparing to the type strains of S. lactis DSM 22361T, S. soli NCCP 698T, S. endophyticum NYYP31T and S. olei HAL-9T, which are below the cut-off level (95-96 %) for species delineation. Based on the above results, strain PU5-4T represents a novel species of the genus Sphingobacterium, for which the name Sphingobacterium temoinsis sp. nov. is proposed. The type strain is PU5-4T (=CGMCC 1.61908T=JCM 36663T).

Oxidative MnO2 Template Assisted Electrochemical Fabrication of Graphene/Polypyrrole Supercapacitor Electrodes.

Improving the morphological structure of active materials is a reliable strategy for the fabrication of high-performance supercapacitor electrodes. In this study, we introduce a feasible approach to constructing the graphene/polypyrrole (PPy) composite film implanted onto the current collector through a two-step electrochemical deposition method utilizing MnO2 as an intermediary template. The reduced graphene oxide (rGO) hydrogel film is first hydrothermally grown on a carbon cloth (CC) substrate to obtain a porous rGO@CC electrode on which MnO2 is electrodeposited. Then the as-prepared rGO/MnO2@CC electrode is subjected to the electrochemical polymerization of pyrrole, with MnO2 acting as an oxidizing template to facilitate the oxidative polymerization of pyrrole, ultimately yielding an rGO/PPy composite film on CC. The PPy synthesized via this methodology exhibits a distinctive interconnected structure, resulting in superior electrochemical performance compared with the electrode with PPy directly electrodeposited on rGO@CC. The optimized electrode achieves an impressive specific capacitance of 583.6 F g-1 at 1 A g-1 and retains 83% of its capacitance at 20 A g-1, with a capacitance loss of only 9.5% after 5000 charge-discharge cycles. The corresponding all-solid-state supercapacitor could provide a high energy density of 22.5 Wh kg-1 and a power density of 4.6 kW kg-1, with a capacitance retention of 82.7% after 5000 charge-discharge cycles. Furthermore, the device also demonstrates good flexibility performance upon bending at 90 and 180°. This work presents an innovative method for the preparation of carbon material/conducting polymer electrodes with specific structural characteristics and superior performance.

One-Step Fabrication of Integrated Graphene/Polypyrrole/Carbon Cloth Films for Supercapacitor Electrodes.

The facile and cost-effective preparation of supercapacitor electrodes is significant for the application of this kind of electrochemical energy-storing module. In this work, we designed a feasible strategy to fabricate a binary active material onto a current collector in one step. A colloidal mixture of graphene oxide and pyrrole layered on a carbon cloth could undergo a redox reaction through a mild hydrothermal process to yield a reduced graphene oxide/polypyrrole hydrogel film anchored onto the carbon cloth. The integrated electrode with the porous graphene/polypyrrole active material could be directly utilized as a freestanding working electrode for electrochemical measurements and the assembly of supercapacitor devices. The as-prepared electrode could achieve a high capacitance of 1221 mF cm-2 at 1 mA cm-2 (531 F g-1) with satisfactory cycling stability. The constructed symmetric supercapacitor with two optimal electrodes could provide an energy density of 70.4 µWh cm-2 (15.3 Wh kg-1). This work offers a feasible pathway toward the integration of graphene/conducting polymer composites as electrochemical electrodes.

Covalent Organic Framework Fiber-Constructed Artificial Solid Electrolyte Interphase Layer: Facilitated Uniform Deposition of Li+ and Encapsulated Li Dendrite.

Due to ultrahigh theoretical capacity and ultralow redox poteneial, lithium metal is considered as a promising anode material. However, uneven lithium deposition, uncontrollable lithium dendrite formation, and fragile solid electrolyte interphase (SEI) lead to low lithium utilization, rapid capacity decay, and poor cycle performance. Herein, a robust artificial SEI film by coating the lithium surface with fibrous covalent organic framework (Fib-COF) was constructed, which effectively prevented dendrite penetration and battery short-circuits. Experimental results demonstrated that the Fib-COF-decorated batteries showcased higher Coulombic efficiency (CE), extended cycling stability, and superior electrolyte compatibility. The strong affinity of the carbonyl group in Fib-COF towards Li+ contributes to facilitating the Li+ uniform transfer and nucleation. In situ optical microscopy dynamically revealed the formation process of dendrite-free interphase under the function of Fib-COF layer. As a result, the modified Li anode demonstrated remarkable cycle stability for more than 650 h at 20 mA cm-2 and 5 mAh cm-2 in ether-based electrolyte and 1000 h at 0.5 mA cm-2 and 0.5 mAh cm-2 in carbonate-based electrolyte. The dendrite-free Fib-COF@Li electrodes endowed higher specific capacities of 650 mAh g-1 for Fib-COF@Li|S full cell after 250 cycles and 120 mAh g-1 for Fib-COF @Li|LiFePO4 full cells after 300 cycles.

Synthesis of Trifluoromethylated Dibenzoxepines via Palladium-Catalyzed Tandem C-O Bond Formation/C-H Arylation.

A palladium-catalyzed cyclization reaction of phenols with trifluoromethyl-containing ortho-bromo-ß-chlorostyrenes has been developed. In the presence of palladium(II) acetate, tricyclohexylphosphine, and cesium carbonate, a variety of 6-trifluoromethyldibenzo[b,d]oxepines were prepared in moderate to good yields through the tandem O-alkenylation of general phenols and subsequent C-H arylation.

Rapid imaging and product screening with low-cost line-field Fourier domain optical coherence tomography.

Fourier domain optical coherence tomography (FD-OCT) is a well-established imaging technique that provides high-resolution internal structure images of an object at a fast speed. Modern FD-OCT systems typically operate at speeds of 40,000-100,000 A-scans/s, but are priced at least tens of thousands of pounds. In this study, we demonstrate a line-field FD-OCT (LF-FD-OCT) system that achieves an OCT imaging speed of 100,000 A-scan/s at a hardware cost of thousands of pounds. We demonstrate the potential of LF-FD-OCT for biomedical and industrial imaging applications such as corneas, 3D printed electronics, and printed circuit boards.

Maintaining her image: A social comparative evaluation of the particularity of mothers in the Chinese cultural context.

In Chinese culture, the mother holds a special meaning in one's self-concept, and is perceived as being stablyincorporated into and consistent with the self. However, it is unclear whether the evaluation of mothers by individuals is affected following the initiation of upward and downward social comparisons (USC and DSC). This experiment manipulated USC and DSC by evaluating positive and negative public figures and used functional near-infrared spectroscopy to record changes in brain activity during the evaluation. It was found that participants' evaluations of their mothers and their brain activity did not differ from the self during USC, verifying the equivalence of the mother and the self. In DSC, participants made significantly more positive social judgments about their mothers, accompanied by greater activation of the left temporal lobe. These results suggest that the mother was not only stably incorporated into the self but was in a position of even greater importance than the self. In DSC in particular, individuals are more likely to maintain a positive image of their mother.

[Advances in poly(ethylene terephthalate) hydrolases].

Plastics have brought invaluable convenience to human life since it was firstly synthesized in the last century. However, the stable polymer structure of plastics led to the continuous accumulation of plastic wastes, which poses serious threats to the ecological environment and human health. Poly(ethylene terephthalate) (PET) is the most widely produced polyester plastics. Recent researches on PET hydrolases have shown great potential of enzymatic degradation and recycling of plastics. Meanwhile, the biodegradation pathway of PET has become a reference model for the biodegradation of other plastics. This review summarizes the sources of PET hydrolases and their degradation capacity, degradation mechanism of PET by the most representative PET hydrolase-IsPETase, and recently reported highly efficient degrading enzymes through enzyme engineering. The advances of PET hydrolases may facilitate the research on the degradation mechanism of PET and further exploration and engineering of efficient PET degradation enzymes.

Insights into autotrophic carbon fixation strategies through metagonomics in the sediments of seagrass beds.

Seagrass beds contributes up to 10% ocean carbon storage. Carbon fixation in seagrass bed greatly affect global carbon cycle. Currently, six carbon fixation pathways are widely studied: Calvin, reductive tricarboxylic acid (rTCA), Wood-Ljungdahl (WL), 3-hydroxypropionate (3HP), 3-hydroxypropionate/4-hydroxybutyrate (3HP/4HB) and dicarboxylate/4-hydroxybutyrate (DC/4-HB). Despite the knowledges about carbon fixation increase, the carbon fixation strategies in seagrass bed sediment remain unexplored. We collected seagrass bed sediment samples from three sites with different characteristics in Weihai, a city in Shandong, China. The carbon fixation strategies were investigated through metagenomics. The results exhibited that five pathways were present, of which Calvin and WL were the most dominant. The community structure of microorganisms containing the key genes of these pathways were further analyzed, and those dominant microorganisms with carbon fixing potential were revealed. Phosphorus significantly negatively corelated with those microorganisms. This study provides an insight into the strategies of carbon fixation in seagrass bed sediments.

Role of apigenin in high glucose-induced retinal microvascular endothelial cell dysfunction via regulating NOX4/p38 MAPK pathway in vitro.

AIM: To investigate the retinoprotective role of Apigenin (Api) against high glucose (HG)-induced human retinal microvascular endothelial cells (HRMECs), and to explore its regulatory mechanism. METHODS: HRMECs were stimulated by HG for 48h to establish the in vitro cell model. Different concentrations of Api (2.5, 5, and 10 µmol/L) were applied for treatment. Cell counting kit-8 (CCK-8), Transwell, and tube formation assays were performed to examine the effects of Api on the viability, migration, and angiogenesis in HG-induced HRMECs. Vascular permeability was evaluated by Evans blue dye. The inflammatory cytokines and oxidative stress-related factors were measured using their commercial kits. Protein expression of nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) and p38 mitogen-activated protein kinase (MAPK) was measured by Western blot. RESULTS: Api prevented HG-induced HRMECs viability, migration, angiogenesis, and vascular permeability in a concentration-dependent manner. Meanwhile, Api also concentration-dependently inhibited inflammation and oxidative stress in HRMECs exposed to HG. In addition, HG caused an elevated expression of NOX4, which was retarded by Api treatment. HG stimulation facilitated the activation of p38 MAPK signaling in HRMECs, and Api could weaken this activation partly via downregulating NOX4 expression. Furthermore, overexpression of NOX4 or activation of p38 MAPK signaling greatly weakened the protective role of Api against HG-stimulated HRMECs. CONCLUSION: Api might exert a beneficial role in HG-stimulated HRMECs through regulating NOX4/p38 MAPK pathway.

A Dual Fluorescence Assay Enables High-Throughput Screening for Poly(ethylene terephthalate) Hydrolases.

The drastically increasing consumption of petroleum-derived plastics hasserious environmental impacts and raises public concerns. Poly(ethylene terephthalate) (PET) is amongst the most extensively produced synthetic polymers. Enzymatic hydrolysis of PET recently emerged as an enticing path for plastic degradation and recycling. In-lab directed evolution has revealed the great potential of PET hydrolases (PETases). However, the time-consuming and laborious PETase assays hinder the identification of effective variants in large mutant libraries. Herein, we devise and validate a dual fluorescence-based high-throughput screening (HTS) assay for a representative IsPETase. The two-round HTS of a pilot library consisting of 2850 IsPETase variants yields six mutant IsPETases with 1.3-4.9 folds improved activities. Compared to the currently used structure- or computational redesign-based PETase engineering, this HTS approach provides a new strategy for discovery of new beneficial mutation patterns of PETases.

Mode of action of nanochitin whisker against Fusarium pseudograminearum.

Nanochitin whisker (NC) is an advanced nanobiomaterial with novel physicochemical and biological properties. Fusarium pseudograminearum (Fpg) is an important pathogenic fungus causing wheat crown rot disease. This study explored the mode of action of NC against Fpg as a target microorganism. The effects of different treatments and concentrations of NC on the fungal growth and conidial germination were investigated by in vitro bioassay. The impacts of NC on cell structure integrity, membrane permeability, pathogenesis related key enzymes activity, and the mycotoxin production were examined by electron microscopy, fluorescence spectroscopy, IR spectroscopy, conductometry, and spectrophotometry, respectively. The results showed that NC significantly reduced hyphal growth, and the spore germination rate of Fpg declined by 33.0 % and 23.2 % when Fpg was treated with 30 and 300 µg/mL of NC, respectively. NC vigorously influenced structural stability of cell wall by destroying dextran structure, and strongly stimulated ergosterol production altering membrane integrity of the fungus. It reduced the activities of enzymes related to energy-supply like nicotinamide adenine dinucleotide oxidase and succinate dehydrogenase remarkably. The production of fungal mycotoxin deoxynivalenol was also decreased by NC. These findings provide an important basis for fully understanding the mechanism of nanobiomaterial in plant fungal disease control.

Nondestructive in situ monitoring of pea seeds germination using optical coherence tomography.

Seed germination and uniform plant stand in the field are the most critical crop growth stages determining the final yield. Pea (Pisum sativum L.) seeds production is often hampered due to the seed dormancy caused by the hard seed coat. Such effect is mainly attributed to poor or uneven germination and unsynchronised seedling emergence. Understanding the time course of water intake and several critical germination indicators can reveal many features of seed germination such as rate and uniformity. This paper used optical coherence tomography (OCT), a noninvasive and cross-sectional imaging technique, to monitor the inner structural changes throughout the germination process. A sequence of cross-sectional OCT images of pea (P. sativum L.) seeds, together with additional microscopic optical images, was recorded continuously and in situ for over 40 h. OCT and microscopic images revealed the changes in the internal structure and the external shape of the pea seeds during germination, respectively. It was found that the cross-sectional OCT images helped to identify the critical indicators distinguishing the different phases of germination pea seeds. Therefore, the presented OCT approach offers a fast and nondestructive way to precisely measure the structural indicators in different germination phases.

Influence of atmospheric teleconnections on interannual variability of Arctic-boreal fires.

Fires across the Arctic-boreal zone (ABZ) play an important role in the boreal forest succession, permafrost thaw, and the regional and global carbon cycle and climate. These fires occur mainly in summer with large interannual variability. Previous studies primarily focused on the impacts of local surface climate and tropical El Niño-Southern Oscillation (ENSO). This study, for the first time, comprehensively investigates the influence of summer leading large-scale atmospheric teleconnection patterns in the Northern Hemisphere extra-tropics on interannual variability of ABZ fires. We use correlation and regression analysis of 1997-2019 multiple satellite-based products of burned area and observed/reanalyzed climate data. Results show that eight leading teleconnection patterns significantly affect 63 ± 2 % of burned areas across the ABZ. Western North America is affected by the East Pacific/North Pacific pattern (EP/NP) and the West Pacific pattern (WP); boreal Europe by the Scandinavia pattern (SCA); eastern North America, western and central Siberia, and southeastern Siberia by the North Atlantic Oscillation (NAO); and eastern Siberia /Russian Far East by the East Atlantic pattern (EA). NAO/EA induces lower-tropospheric drier northwesterly/northerly airflow passing through the east of boreal North America/Eurasia, which decreases surface relative humidity. Other teleconnections trigger a high-pressure anomaly, forcing downward motion that suppresses cloud formation and increases solar radiation reaching the ground to warm the surface air as well as brings drier air downward to reduce surface relative humidity. The drier and/or warmer surface air can decrease fuel wetness and thus increase burned area. Our study highlights the important role of the extra-tropical teleconnection patterns on ABZ fires, which is much stronger than ENSO that was thought to control interannual variability of global fires. It also establishes a theoretical foundation for ABZ fire prediction based on extra-tropical teleconnections, and has the potential to facilitate ABZ fire prediction and management.

Atorvastatin regulates the migration and invasion of prostate cancer through the epithelial-mesenchymal transformation and matrix metalloproteinase pathways.

PURPOSE: Our purpose was to verify the effects of atorvastatin (ATO) on prostate cancer (PCa) proliferation, apoptosis, invasion, and metastasis and to further explore the drug's mechanism of action. MATERIALS AND METHODS: We used cell counting kit-8 (CCK8) and clone formation experiments to study the effect of ATO on the proliferation of PC3 cells. Flow cytometry and Hoechst 33342 staining were used to detect cell apoptosis. Cell migration and invasion were detected through wound healing experiments and transwell experiments. Western blotting was applied to detect apoptosis-related proteins (BAX, Bcl-2, PARP, and Caspase-3), epithelial-mesenchymal transformation (EMT) proteins, and matrix metalloproteinase (MMP) expression. A mouse xenograft tumor model was established, and tumor volume and weight were determined. The expression levels of the above-mentioned proteins were determined through western blot. RESULTS: ATO inhibited PC-3 cell proliferation and promoted cell apoptosis in a dose-dependent manner. ATO significantly up-regulated the expression of BAX, PARP, and Caspase-3 and inhibited the expression of Bcl-2. Wound healing and transwell experiments showed that ATO inhibited invasion and metastasis in PC-3 cells, possibly because ATO could inhibit the EMT and the expression of MMPs in PC-3 cells. Studies in nude mice showed that ATO significantly reduced tumor volume and weight; the expression levels of related proteins were consistent with the in vitro results. CONCLUSIONS: ATO inhibits the occurrence and development of PCa and regulates the migration and invasion of PCa cells by inhibiting the EMT and MMPs.

Effect of slightly acidic electrolyzed water on natural Enterobacteriaceae reduction and seed germination in the production of alfalfa sprouts.

Microbial contamination of sprouts commonly occurs because of the pathogens present on and in the seeds and the optimal conditions for bacteria growth provided during the germination and sprouting processes. This study examined the decontamination effect of slightly acidic electrolyzed water (SAEW), a 'generally recognized as safe' (GRAS) disinfectant, in the production process of alfalfa sprouts. SAEW with various available chlorine concentrations (ACC, 25, 35, 45 mg/L) and different pH levels (5.0, 5.7 and 6.4) was used to soak seeds for different length of time (0.5 and 6 h), after which the variations in natural Enterobacteriaceae, water absorption and seed germination (germination rate, weight and length of sprouts) were determined. The results showed that when the seeds were soaked with SAEW, albeit with different ACC (25, 35 and 45 mg/L) and pH levels (5.0, 5.7 and 6.4), a significant reduction of Enterobacteriaceae and no negative effect on sprout quality was observed. The water absorption and germination rates were also not significantly adversely affected by SAEW soaking. These findings suggest that SAEW could be used to decontaminate natural Enterobacteriaceae in the production of alfalfa sprouts, with no negative side effects on the alfalfa seeds.