Effect of Chitosan and Hyperbranched Poly-L-Lysine Treatment on Quality of Cucumber (Cucumis sativus L.) during Storage.

To enhance the storage time of cucumbers, this research investigated the impact of chitosan (CS) and hyperbranched poly-L-lysine (HBPL) on the quality and nutritional attributes of cucumbers when stored at a temperature of 25 °C. The results demonstrated that sensory evaluation scores for cucumbers treated with a CS-HBPL combination were significantly higher than the control (CK), CS, and HBPL groups. On the 18th day of storage, cucumbers in the CK group exhibited significant decay and softening; however, there was a decrease in hardness observed in the CS-HBPL group and no decay or noticeable sour taste was detected. Furthermore, compared to the CK group, treatment with CS-HBPL effectively delayed cucumber decay and weight loss rate while significantly inhibiting decreases in cucumber hardness and growth of surface microorganisms. Additionally, it substantially reduced losses of soluble protein content as well as vitamin C (Vc), reducing sugars, and total phenolic compounds within cucumbers, which were 4.7 mg/g, 4.7 mg/g, 0.94 mg/g, and 0.52 mg/kg, respectively. Moreover, compared to the CK group, combined treatment with CS-HBPL significantly inhibited malondialdehyde (MDA) accumulation and reducing relative electrolyte permeability within cucumbers, which were 1.45 µmol·g-1FW and 29.82%. Furthermore, it notably enhanced activities of superoxide dismutase (SOD) and catalase (CAT), while exerting a significant inhibitory effect on polyphenol oxidase (PPO). In summary, the combined CS-HBPL treatment successfully prolonged cucumber shelf life at room temperature, enabling new possibilities for extending cucumber shelf life.

Effect-directed analysis of androgenic compounds from sewage sludges in China.

The safety of municipal sewage sludge has raised great concerns because of the accumulation of large-scale endocrine disrupting chemicals in the sludge during wastewater treatment. The presence of contaminants in sludge can cause secondary pollution owing to inappropriate disposal mechanisms, posing potential risks to the environment and human health. Effect-directed analysis (EDA), involving an androgen receptor (AR) reporter gene bioassay, fractionation, and suspect and nontarget chemical analysis, were applied to identify causal AR agonists in sludge; 20 of the 30 sludge extracts exhibited significant androgenic activity. Among these, the extracts from Yinchuan, Kunming, and Shijiazhuang, which held the most polluted AR agonistic activities were prepared for extensive EDA, with the dihydrotestosterone (DHT)-equivalency of 2.5 - 4.5 ng DHT/g of sludge. Seven androgens, namely boldione, androstenedione, testosterone, megestrol, progesterone, and testosterone isocaproate, were identified in these strongest sludges together, along with testosterone cypionate, first reported in sludge media. These identified androgens together accounted for 55 %, 87 %, and 52 % of the effects on the sludge from Yinchuan, Shijiazhuang, and Kunming, respectively. This study elucidates the causative androgenic compounds in sewage sludge and provides a valuable reference for monitoring and managing androgens in wastewater treatment.

Microglial exosomes in paraquat-induced Parkinson's disease: Neuroprotection and biomarker clues.

The exact mechanisms underlying the initiation and exacerbation of Parkinson's disease (PD) by paraquat remain unclear. We have revealed that exosomes mediate neurotoxicity induced by low dose paraquat exposure by transmitting intercellular signaling. Exposure to 40 µM paraquat promoted exosome release from mouse microglia cells (BV2) in vitro. Paraquat exposure at 100 µM caused degeneration of mouse dopaminergic MN9D cells and inhibited microglia exosome uptake by fluorescently labeling exosomes. We established an incubation model for exosomes and dopaminergic neuron cells under PQ treatment. The results indicated that microglial exosomes alleviated degeneration, increasing proliferation and PD-related protein expression of dopaminergic neurons; however, paraquat reversed this effect. Then, through exosome high-throughput sequencing and qRT-PCR experiments, miR-92a-3p and miR-24-3p were observed to transfer from exosomes to dopaminergic neurons, inhibited by paraquat. The specificity of miR-92a-3p and miR-24-3p was verified in PD patients exosomes, indicating the potential diagnostic value of the exosomal miRNAs in paraquat-induced PD. These results suggest glia-neuron communication in paraquat-induced neurodegeneration and may identify stable paraquat-mediated PD biomarkers, offering clues for early recognition and prevention of pesticide-induced degenerative diseases.

Spire2 and Rab11a synergistically activate myosin-5b motor function.

Cellular vesicle long-distance transport along the cytoplasmic actin network has recently been uncovered in several cell systems. In metaphase mouse oocytes, the motor protein myosin-5b (Myo5b) and the actin nucleation factor Spire are recruited to the Rab11a-positive vesicle membrane, forming a ternary complex of Myo5b/Spire/Rab11a that drives the vesicle long-distance transport to the oocyte cortex. However, the mechanism underlying the intermolecular regulation of the Myo5b/Spire/Rab11a complex remains unknown. In this study, we expressed and purified Myo5b, Spire2, and Rab11a proteins, and performed ATPase activity measurements, pulldown and single-molecule motility assays. Our results demonstrate that both Spire2 and Rab11a are required to activate Myo5b motor activity under physiological ionic conditions. The GTBM fragment of Spire2 stimulates the ATPase activity of Myo5b, while Rab11a enhances this activation. This activation occurs by disrupting the head-tail interaction of Myo5b. Furthermore, at the single-molecule level, we observed that the GTBM fragment of Spire2 and Rab11a coordinate to stimulate the Myo5b motility activity. Based on our results, we propose that upon association with the vesicle membrane, Myo5b, Spire2 and Rab11a form a ternary complex, and the inhibited Myo5b is synergistically activated by Spire2 and Rab11a, thereby triggering the long-distance transport of vesicles.

An Anatomy- and Topology-Preserving Framework for Coronary Artery Segmentation.

Coronary artery segmentation is critical for coronary artery disease diagnosis but challenging due to its tortuous course with numerous small branches and inter-subject variations. Most existing studies ignore important anatomical information and vascular topologies, leading to less desirable segmentation performance that usually cannot satisfy clinical demands. To deal with these challenges, in this paper we propose an anatomy- and topology-preserving two-stage framework for coronary artery segmentation. The proposed framework consists of an anatomical dependency encoding (ADE) module and a hierarchical topology learning (HTL) module for coarse-to-fine segmentation, respectively. Specifically, the ADE module segments four heart chambers and aorta, and thus five distance field maps are obtained to encode distance between chamber surfaces and coarsely segmented coronary artery. Meanwhile, ADE also performs coronary artery detection to crop region-of-interest and eliminate foreground-background imbalance. The follow-up HTL module performs fine segmentation by exploiting three hierarchical vascular topologies, i.e., key points, centerlines, and neighbor connectivity using a multi-task learning scheme. In addition, we adopt a bottom-up attention interaction (BAI) module to integrate the feature representations extracted across hierarchical topologies. Extensive experiments on public and in-house datasets show that the proposed framework achieves state-of-the-art performance for coronary artery segmentation.

A new C19-diterpenoid alkaloid in Aconitum georgei Comber.

Nine diterpenoid alkaloids were isolated from Aconitum georgei Comber belonging to the genus Aconitum in Ranunculaceae family. Their structures were determinated by using HR-ESI-MS and 1 D/2D NMR spectra as geordine (1), yunaconitine (2), chasmanine (3), crassicauline A (4), forestine (5), pseudaconine (6), 14-acetylalatisamine (7), austroconitine B (8), and talatisamine (9). Among them, compound 1 is a previously undescribed aconitine-type C19-diterpenoid alkaloid, and compounds 3, and 5-9 have not previously been isolated from this species. The results of in vitro experiments indicated that new compound 1 possesses mild anti-inflammatory activity, which inhibited the production of NO in LPS-activated RAW 264.7 cells with an inhibition ratio of 29.75% at 50 µM.

Characterizing bacterial and fungal communities along the longitudinal axis of the intestine in cynomolgus monkeys.

IMPORTANCE: Gut microbiota varies along the gastrointestinal (GI) tract and exerts profound influences on the host's physiology, immunity, and nutrition. Given that gut microbes interact with the host closely and the gastrointestinal function differed from the small to the large intestine, it is essential to characterize the gut biogeography of the microbial community. Here, we focused on intestinal bacteria and fungi in cynomolgus monkeys and determined their spatial distribution along the GI tract by performing 16S and 18S rRNA gene sequencing. The composition and function of bacterial and fungal communities differed significantly at different biogeographic sites of the intestine, and the site-specific correlations between intestinal bacteria and fungi were revealed. Thus, our studies characterized the gut biogeography of bacteria and fungi in NHPs and revealed their site-specific correlations along the GI tract.

Environmental Stability and Transmissibility of Enveloped Viruses at Varied Animate and Inanimate Interfaces.

Enveloped viruses have been the leading causative agents of viral epidemics in the past decade, including the ongoing coronavirus disease 2019 outbreak. In epidemics caused by enveloped viruses, direct contact is a common route of infection, while indirect transmissions through the environment also contribute to the spread of the disease, although their significance remains controversial. Bridging the knowledge gap regarding the influence of interfacial interactions on the persistence of enveloped viruses in the environment reveals the transmission mechanisms when the virus undergoes mutations and prevents excessive disinfection during viral epidemics. Herein, from the perspective of the driving force, partition efficiency, and viral survivability at interfaces, we summarize the viral and environmental characteristics that affect the environmental transmission of viruses. We expect to provide insights for virus detection, environmental surveillance, and disinfection to limit the spread of severe acute respiratory syndrome coronavirus 2.

Renaissance of elemental phosphorus materials: properties, synthesis, and applications in sustainable energy and environment.

The polymorphism of phosphorus-based materials has garnered much research interest, and the variable chemical bonding structures give rise to a variety of micro and nanostructures. Among the different types of materials containing phosphorus, elemental phosphorus materials (EPMs) constitute the foundation for the synthesis of related compounds. EPMs are experiencing a renaissance in the post-graphene era, thanks to recent advancements in the scaling-down of black phosphorus, amorphous red phosphorus, violet phosphorus, and fibrous phosphorus and consequently, diverse classes of low-dimensional sheets, ribbons, and dots of EPMs with intriguing properties have been produced. The nanostructured EPMs featuring tunable bandgaps, moderate carrier mobility, and excellent optical absorption have shown great potential in energy conversion, energy storage, and environmental remediation. It is thus important to have a good understanding of the differences and interrelationships among diverse EPMs, their intrinsic physical and chemical properties, the synthesis of specific structures, and the selection of suitable nanostructures of EPMs for particular applications. In this comprehensive review, we aim to provide an in-depth analysis and discussion of the fundamental physicochemical properties, synthesis, and applications of EPMs in the areas of energy conversion, energy storage, and environmental remediation. Our evaluations are based on recent literature on well-established phosphorus allotropes and theoretical predictions of new EPMs. The objective of this review is to enhance our comprehension of the characteristics of EPMs, keep abreast of recent advances, and provide guidance for future research of EPMs in the fields of chemistry and materials science.

H2 S works synergistically with rhizobia to modify photosynthetic carbon assimilation and metabolism in nitrogen-deficient soybeans.

Hydrogen sulfide (H2 S) performs a crucial role in plant development and abiotic stress responses by interacting with other signalling molecules. However, the synergistic involvement of H2 S and rhizobia in photosynthetic carbon (C) metabolism in soybean (Glycine max) under nitrogen (N) deficiency has been largely overlooked. Therefore, we scrutinised how H2 S drives photosynthetic C fixation, utilisation, and accumulation in soybean-rhizobia symbiotic systems. When soybeans encountered N deficiency, organ growth, grain output, and nodule N-fixation performance were considerably improved owing to H2 S and rhizobia. Furthermore, H2 S collaborated with rhizobia to actively govern assimilation product generation and transport, modulating C allocation, utilisation, and accumulation. Additionally, H2 S and rhizobia profoundly affected critical enzyme activities and coding gene expressions implicated in C fixation, transport, and metabolism. Furthermore, we observed substantial effects of H2 S and rhizobia on primary metabolism and C-N coupled metabolic networks in essential organs via C metabolic regulation. Consequently, H2 S synergy with rhizobia inspired complex primary metabolism and C-N coupled metabolic pathways by directing the expression of key enzymes and related coding genes involved in C metabolism, stimulating effective C fixation, transport, and distribution, and ultimately improving N fixation, growth, and grain yield in soybeans.

ERV14 receptor impacts mycelial growth via its interactions with cell wall synthase and transporters in Aspergillus niger.

Efficient protein secretion is closely correlated with vesicle sorting and packaging, especially with cargo receptor-mediated selective transport for ER exit. Even though Aspergillus niger is considered an industrially natural host for protein production due to its exceptional secretion capacity, the trafficking mechanism in the early secretory pathway remains a black box for us to explore. Here, we identified and characterized all putative ER cargo receptors of the three families in A. niger. We successfully constructed overexpression and deletion strains of each receptor and compared the colony morphology and protein secretion status of each strain. Among them, the deletion of Erv14 severely inhibited mycelial growth and secretion of extracellular proteins such as glucoamylase. To gain a comprehensive understanding of the proteins associated with Erv14, we developed a high-throughput method by combining yeast two-hybrid (Y2H) with next-generation sequencing (NGS) technology. We found Erv14 specifically interacted with transporters. Following further validation of the quantitative membrane proteome, we determined that Erv14 was associated with the transport of proteins involved in processes such as cell wall synthesis, lipid metabolism, and organic substrate metabolism.

TaG-Net: Topology-Aware Graph Network for Centerline-Based Vessel Labeling.

Anatomical labeling of head and neck vessels is a vital step for cerebrovascular disease diagnosis. However, it remains challenging to automatically and accurately label vessels in computed tomography angiography (CTA) since head and neck vessels are tortuous, branched, and often spatially close to nearby vasculature. To address these challenges, we propose a novel topology-aware graph network (TaG-Net) for vessel labeling. It combines the advantages of volumetric image segmentation in the voxel space and centerline labeling in the line space, wherein the voxel space provides detailed local appearance information, and line space offers high-level anatomical and topological information of vessels through the vascular graph constructed from centerlines. First, we extract centerlines from the initial vessel segmentation and construct a vascular graph from them. Then, we conduct vascular graph labeling using TaG-Net, in which techniques of topology-preserving sampling, topology-aware feature grouping, and multi-scale vascular graph are designed. After that, the labeled vascular graph is utilized to improve volumetric segmentation via vessel completion. Finally, the head and neck vessels of 18 segments are labeled by assigning centerline labels to the refined segmentation. We have conducted experiments on CTA images of 401 subjects, and experimental results show superior vessel segmentation and labeling of our method compared to other state-of-the-art methods.

Efficient and selective removal of Hg(II) from water using recyclable hierarchical MoS2/Fe3O4 nanocomposites.

Developing practical and cost-effective adsorbents with satisfactory mercury (Hg) remediation capability is indispensable for aquatic environment safety and public health. Herein, a recyclable hierarchical MoS2/Fe3O4 nanocomposite (by in-situ growth of MoS2 nanosheets on the surface of Fe3O4 nanospheres) is presented for the selective removal of Hg(II) from aquatic samples. It exhibited high adsorption capacity (∼1923.5 mg g -1), fast kinetics (k2 ∼ 0.56 mg g -1 min-1), broad working pH range (2-11), excellent selectivity (Kd > 1.0 × 107 mL g -1), and great reusability (removal efficiency > 90% after 20 cycles). In particular, removal efficiencies of up to ∼97% for different Hg(II) concentrations (10-1000 µg L -1) in natural water and industrial effluents confirmed the practicability of MoS2/Fe3O4. The possible mechanism for effective Hg(II) removal was discussed by a series of characterization analyses, which was attributed to the alteration of the MoS2 structure and the surface coordination of Hg-S. The accessibility of surface sulfur sites and the diffusion of Hg(II) in the solid-liquid system were enhanced due to the advantage of the expanded interlayer spacing (0.96 nm) and the hierarchical structure. This study suggests that MoS2/Fe3O4 is a promising material for Hg(II) removal in actual scenarios and provides a feasible approach by rationally constructing hierarchical structures to promote the practical applications of MoS2 in sustainable water treatments.

Comparison and quantification of estrogen receptor-mediated responsiveness to endocrine disruptors in bivalves by using complementary model and a novel yeast assay approach.

Endocrine disrupting chemicals (EDCs) in estuaries and coastal habitats have been widely detected over the world and caused global concern. Bivalves have been shown to be vulnerable to endocrine disruption. However, estrogen receptors (ERs) sensitivity to steroids and EDCs has long been considered to be restricted to vertebrates. In the present study, a computational simulation docking model was applied to qualitatively predict the binding behavior of two bivalve ERs to estradiol and compared the docking activity with zebra fish ERa. A novel reconstituted yeast system was constructed by using transcriptional activator GAL-4 consists of ER-expressing plasmid and ERE (estrogen responsive element)-containing plasmid. The assays showed that bivalve ER specifically activate transcription in response to tested steroids and EDCs, but the activation ability is weaker compared to zebra fish ERa. The results corroborate the presence of an active ER in bivalve molluscs and provide a promising tool for screening of marine environmental pollutants active in disturbing ERs of bivalves, as well as understanding the underlying mechanism across taxonomic groups and phyla.

UV-ARTP-DES compound mutagenesis breeding improves natamycin production of Streptomyces natalensis HW-2 and reveals transcriptional changes by RNA-seq.

Natamycin is widely used in food, medical and health, agriculture, and animal husbandry. In this study, Streptomyces natalensis HW-2 was used as the research object, and a mutant DES-26 with stable genetic characters was selected by UV-ARTP-DES compound mutation. The natamycin yield was 1.64 g/L, 86.36% higher than original strain. Differential expression genes were analyzed by transcriptomics, and results showed that 295 and 860 genes were significantly differentially expressed at fermentation for 48 h and 72 h. GO and KEGG analysis showed that compound mutagenesis had a significant impact on glycolysis, pentose phosphate, TCA cycle, fatty acid metabolism pathways, and several key enzyme genes in the pathways were up-regulated, and genes related to natamycin biosynthesis (pimB-pimI) and transcriptional regulator (pimR) were also up-regulated. qRT-PCR results confirmed that expression levels of these genes were consistent with transcriptional changes of RNA-Seq. Supplementary Information: The online version contains supplementary material available at 10.1007/s10068-022-01191-z.

Macrostines A and B: Tetracyclic fisicoccane from the fungus Periconia macrospinosa WTG-10.

Two previous unreported fusicoccane diterpenoids macrostines A and B, together with seven known compounds were isolated from an extract of the fungus Periconia macrospinosa WTG-10. Their structures were elucidated by detailed analysis of spectroscopic data, NMR calculations with DP4+, and their absolute configurations were further determined by quantum chemical calculations of ECD spectra or X-crystallography. Macrostines A and B showed no cytotoxicity, antimicrobial activity and inhibitory effect on nitric oxide production in LPS-activated RAW264.7 macrophages. Compound 9 showed moderate activity against Bacillus subtilis.

Transcriptomic response to GnRH down regulation by RNA interference in clam Ruditapes philippinarum, suggest possible role in reproductive function.

Gonadotropin-releasing hormone (GnRH) plays a key role in the control of the reproductive axis in vertebrates, however, little is known about its function in reproductive endocrine regulation in molluscs. In the present study, RNA-seq was used to construct transcriptomes of Ruditapes philippinarum testis and ovaries of control and GnRH suppressed individuals using RNA interference. GnRH suppression caused 112 and 169 enriched KEGG pathways in testis and ovary, with 92 pathways in common in both comparisons. The most enriched KEGG pathways occurred in the "Oxidative phosphorylation", "Dorso-ventral axis formation", "Thyroid hormone synthesis" and "Oxytocin signaling pathway" etc. A total of 1838 genes in testis and 358 genes in ovaries were detected differentially expressed in GnRH suppressed clams. Among the differentially expressed genes, a suit of genes related to regulation of steroid hormones synthesis and gonadal development, were found in both ovary and testis with RNAi of GnRH. These results suggest that GnRH may play an important role in reproductive function in bivalves. This study provides a preliminary basis for studying the function and regulatory mechanism of GnRH in bivalves.

Polyketides with antimicrobial activities from Penicillium canescens DJJ-1.

Two undescribed polyketides canecines A-B, one unreported cyclopentenone canecine C, together with 12 known compounds were isolated from an extract of the fungus Penicillium canescens DJJ-1. Their structures were elucidated by detailed analysis of spectroscopic data, NMR calculations with dJ-DP4 or DP4+, and their absolute configurations were further determined by quantum chemical calculations of ECD spectra or X-crystallography. Canecine A was a grisan polyketide featuring a dimethyltetrahydro-4H-furo[2,3-b]pyran. Canecine A exhibited significant inhibitory activity against Candida albicans with an MIC value of 1 µg/mL and showed inhibitory effect on nitric oxide production in LPS-activated RAW264.7 macrophages. These results enrich the structural diversities of polyketides from endophytic fungi.

Effect of Combined Chitosan and Hyperbranched Poly-L-Lysine Based Coating on Prolonging the Shelf Life of Oyster Mushroom (Pleurotus ostreatus).

To extend the shelf life of oyster mushroom (Pleurotus ostreatus), the effects of chitosan (CS) and hyperbranched poly-L-lysine (HBPL) combined treatment on quality characteristics, nutritional quality, storage characteristics, and enzyme activity of oyster mushroom during postharvest storage at 4 °C were investigated. The results showed that CS-HBPL combined treatment could significantly reduce rot degree and weight loss and significantly inhibit the browning of oyster mushroom. At the same time, the loss of reducing sugar, vitamin C, soluble protein, and total phenolic was significantly reduced. Compared with the control, CS-HBPL combined treatment could also significantly inhibit an increase in malondialdehyde (MDA) and significantly decrease the relative electrolyte leakage of oyster mushroom. In addition, the activities of catalase (CAT), superoxide dismutase (SOD), phenylalnine ammonialyase (PAL), and peroxidase (POD) were significantly improved, and the activity of polyphenol oxidase (PPO) was significantly inhibited in oyster mushroom. In conclusion, CS-HBPL combined treatment had a good protective effect on the membrane permeability damage of oyster mushroom and could effectively delay the oxidation of phenolic substances and browning of oyster mushroom. Therefore, CS-HBPL combined treatment can be used as a potential strategy to extend the storage time of oyster mushroom.

Dynamic landscape of multi-elements in PM2.5 revealed by real-time analysis.

Metal components in fine particulate matter (PM2.5) are closely associated with many adverse health outcomes. Dynamic changes of metals in PM2.5 are critical for risk assessment due to their temporal variations. Herein, an online method for real-time determination of multi-elements (As, Cd, Cs, Cu, Fe, Mg, Mn, Pb, Rb, Sn, Tl, and V) in PM2.5 was established by directly introducing air samples into inductively coupled plasma mass spectrometry (ICPMS). Meanwhile, a quantified method using metal standard aerosols (Cr, Mo, and W) and high time resolution for 3.3 min online measurement was developed and validated. The limits of detection were in the range of 0.001-6.30 ng/m3 for different metals. Subsequently, the real-time contents of multi-elements in PM2.5 for 12 h over 33 days were measured at different air qualities. Temporal variations of crustal elements like Fe, Mg are similar to PM2.5, whereas toxic elements (Pb, As and Cd) have upward trends at dusk. This denoted the association with various emission sources and different exposure concentrations of metals. In addition to the acquisition of real-time information, online analysis of multi-elements in PM2.5 is beneficial for atmospheric monitoring and provides critical insights into the different exposure risks of metals in PM2.5 at varying times.