Search Results (24)

Apples are the most widely consumed temperate fruit worldwide and are often stored for long-term to ensure year-round availability. However, maintaining fruit quality during storage and subsequent shelf-life remain a significant postharvest challenge. This study investigated the combined effects of the harvest stage, cold storage duration, and shelf-life on the physico-chemical properties of Granny Smith apples. Key quality attributes including texture, maturity indices, color, and starch degradation were evaluated using instrumental methods and Raman microscopy. Fruit quality was affected differently by individual factors and their interactions. Texture parameters showed varied sensitivity: the harvest stage affected several parameters, storage duration had the strongest overall impact, shelf-life influenced a moderate number of parameters, and some were affected by combined factor interactions. Maturity indices were significantly influenced by all factors individually and combined. Color parameters were consistently affected by harvest stage and storage, with shelf-life and interactions influencing fewer parameters. These findings emphasize the complex interplay of factors shaping apple quality after harvest. The study demonstrates the importance of timing harvest and tailoring postharvest handling to maintain apple quality. It also demonstrates the potential of combining traditional and advanced techniques for effective ripeness monitoring. Full article

Haploinsufficiency disorders are genetic diseases caused by reduced gene expression, leading to developmental, metabolic, and tumorigenic abnormalities. The dosage-sensitive Retinoic Acid Induced 1 (RAI1) gene, located within the 17p11.2 region, is central to the core features of Smith––Magenis syndrome (SMS) and Potocki––Lupski syndrome (PTLS), caused by the reciprocal microdeletions and microduplications of this region, respectively. SMS and PTLS present contrasting phenotypes. SMS is characterized by severe neurobehavioral manifestations, sleep disturbances, and metabolic abnormalities, and PTLS shows milder features. Here, we detail the molecular functions of RAI1 in its wild-type and haploinsufficiency conditions (RAI1+/−), as studied in animal and cellular models. RAI1 acts as a transcription factor critical for neurodevelopment and synaptic plasticity, a chromatin remodeler within the Histone 3 Lysine 4 (H3K4) writer complex, and a regulator of faulty 5′-capped pre-mRNA degradation. Alterations of RAI1 functions lead to synaptic scaling and transcriptional dysregulation in neural networks. This review highlights key molecular mechanisms of RAI1, elucidating its role in the interplay between genetics and phenotypic features and summarizes innovative therapeutic approaches for SMS. These data provide a foundation for potential therapeutic strategies targeting RAI1, its mRNA products, or downstream pathways. Full article

Acinetobacter baumannii is a significant nosocomial pathogen characterized by the ability to produce a wide variety of capsular polysaccharides (CPSs). The structures of a K102-type CPS isolated from A. baumannii KZ-1102 and its Smith degradation product were determined by sugar analysis, 1D and 2D ¹H NMR spectroscopy, and ¹³C NMR spectroscopy. The K102 CPS biosynthesis gene cluster (KL102) contains genes for common sugar synthesis, K unit processing, capsule export, glycosyl transfer, initiating sugar phosphate transfer, and genes that encode d-GlcpNAc/d-GalpNAc dehydrogenase and phosphoglycerol transferase. The CPS is composed of a pentasaccharide repeating unit (K unit) consisting of a tetrasaccharide backbone including one α-d-Galp, three α-d-GlcpNAc residues, and one residue of a β-d-Glcp as a side chain. The tailspike depolymerase of the specific Obolenskvirus phage Cato was found to cleave the α-d-GlcpNAc-(1→6)-α-d-GlcpNAc linkage in the K102 CPS to give the monomer and dimer of the K repeating unit, which were characterized by high-resolution electrospray ionization mass spectrometry as well as ¹H and ¹³C NMR spectroscopy. Full article

Servo systems are important actuators of aeroengines. The repetitive, reciprocating motion of the servo system leads to significant changes in its time delay and gain characteristics, and degradation increases the uncertainty of these changes. These characteristic variations may have an adverse effect on the dynamic performance of the aeroengine. Therefore, a neural network-based parameter estimation and a multi-loop neural network-based predictive control (ML-NNPC) method for aeroengine inlet guide vane (IGV) servo systems (SVS) were proposed. In this study, the time delay estimation of the servo system was treated as a classification problem, and an SE (squeeze-and-excitation)-GRU (gated recurrent unit) network was proposed to estimate the time delay by using the selected dynamic data of the servo system. The estimated delay was embedded into an online sequential extreme learning machine, and a nonlinear model predictive controller was designed to obtain an optimal control sequence. The compensation control loop was designed to reduce the impact of the model and delay mismatch problems of the control system. The proposed method was applied to the IGV SVS control of a turboshaft engine. The simulation results demonstrate that the time delay is estimated accurately and compensated effectively. Compared to the existing PI and PI with Smith predictor methods, the ML-NNPC method achieves better control performance in the control of both the SVS and the engine rotor speed system. The stability and robustness of the ML-NNPC also show superiority. The results verify the effectiveness of the proposed time delay estimation method and the ML-NNPC method. Full article

Phellinus igniarius is a medicinal fungus. Nonetheless, research on its water-soluble intracellular polysaccharides (IPSW-2 to 4) fractionation, structural elucidation, and antioxidant activity is limited. In this study, water-soluble intracellular polysaccharides (IPSW-2 to 4) were extracted and fractionated from P. igniarius mycelia, and their antioxidant and structural properties were assessed using GC-FID, GC-MS, FTIR, and NMR spectroscopy (¹H and ¹³C). In the water-eluted P. igniarius polysaccharide fractions (IPS30W, IPS60W, and IPS80W) of anion-exchange chromatography, the polysaccharide content was 79.05%, 68.25%, and 62.06%, with higher yields of 25.07%, 21.38%, and 20.34%, respectively. In contrast, the salt (NaCl) elution fractions (IPS30S1, IPS60S1, IPS60S2, and IPS80S1) of anion-exchange chromatography had lower polysaccharide content and yield. Hence, water elution fractions (IPS30W, IPS60W, and IPS80W) were selected for further purification. After repeated purification using size-exclusion chromatography, IPSW-2 to 4 were obtained with a yield of 8% to 15.83%. The IPSW-2 to IPSW-4 structures were elucidated, and they showed no triple helical conformation. Based on periodate oxidation, Smith degradation, methylation analysis, and ¹H and ¹³C NMR spectroscopy, the primary structures of IPSW-2, IPSW-3, and IPSW-4 were all glucan, with the main chain consisting of (1→6)-α-D-Glcp, (1→3,4)-α-D-Glcp, and (1→3, 6)-α-D-Glcp, with α-D-Glcp as a side chain. Finally, antioxidant analysis showed that IPS30W, IPS60W, and IPS80W were all more capable of scavenging superoxide anions than the polysaccharides of Phyllostachys (13.8%) and floribunda (15.1%) at the same concentration (0.40 mg/mL). This will serve as a guide for the development of functional foods. Full article

Agrobacterium sp. are notable for their ability to produce substantial amounts of exopolysaccharides. Our study identified an exopolysaccharide (Galacan, 4982.327 kDa) from Agrobacterium sp. FN01. Galacan is a heteropolysaccharide primarily composed of glucose and galactose at a molar ratio of 25:1. The FT-IR results suggested that Galacan had typical absorption peaks of polysaccharide. The results of periodate oxidation, Smith degradation, and NMR confirmed the presence of structural units, such as β-D-Galp(→, →3)β-D-Galp(1→, →2,3)β-D-Glcp(1→, β-D-Glcp(1→, and →2)β-D-Glcp(1→. Galacan demonstrated significant biological activities. In experiments conducted with zebrafish, it facilitated the proliferation of Lactobacillus brevis in the intestinal tract, suggesting potential prebiotic properties. Moreover, in vivo studies revealed its antihyperglycemic effects, as evidenced by significant reductions in blood glucose levels and enhanced fluorescence intensity of pancreatic β cells in a streptozotocin (STZ)-induced hyperglycemic zebrafish model. Additionally, antiaging assays demonstrated Galacan’s ability to inhibit β-galactosidase activity and enhance telomerase activity in a hydrogen peroxide (HP)-induced aging zebrafish model. These findings emphasized the potential of Galacan as a natural prebiotic with promising applications in diabetes prevention and antiaging interventions. Full article

Sporisorium reilianum is an important biotrophic pathogen that causes head smut disease. Polysaccharides extracted from diseased sorghum heads by Sporisorium reilianum exhibit significant medicinal and edible value. However, the structure and biological activities of these novel polysaccharides have not been explored. In this study, a novel polysaccharide (WM-NP’-60) was isolated and purified from the fruit bodies of S. reilianum and aimed to explore the structural characteristics and substantial antioxidant and antitumor properties of WM-NP’-60. Monosaccharide composition determination, periodate oxidation-Smith degradation, 1D/2D-NMR analysis, and methylation analysis revealed that WM-NP’-60 consisted mainly of β-1,6-D-Glcp, β-1,3-D-Glcp, and β-1,3,6-D-Glcp linkages. The antioxidant assays demonstrated that WM-NP’-60 exhibited great activities, including scavenging free radicals, chelating ferrous ions, and eliminating reactive oxygen species (ROS) within cells. The HepG2, SGC7901, and HCT116 cells examined by transmission electron microscopy (TEM) revealed typical apoptotic bodies. Therefore, a novel fungal polysaccharide (WM-NP’-60) was discovered, extracted, and purified in this experiment, with the aim of providing a reference for the development of a new generation of food and nutraceutical products suitable for human consumption. Full article

The color of an apple is an important index of its appearance quality, which affects the fruit’s marketability and value. The green variety “Granny Smith” remains green when ripe, and the pigment in the peel is mainly chlorophyll. The chlorophyll in the peel of the yellow variety “Golden Delicious” degrades as the fruit ripens. To explore the different mechanisms of chlorophyll degradation in the “Golden Delicious” and “Granny Smith” varieties, transcriptomic analysis was performed on the mature peels of both cultivars. High-quality sequences totaling 48,206,940 and 48,796,646 raw bases, as well as 9632 differentially expressed genes (DEGs), were identified. A total of 1206 DEGs were classified in 118 KEGG metabolic pathways. Additionally, 3258 transcription factors from 428 gene families were predicted, and DEGs associated with chlorophyll degradation, including MdSGR2, MdNYC1 and MdHCAR, were identified. Subsequently, the MdSGR2 gene was isolated from the mature peel of “Granny Smith” apples. Subsequent subcellular localization analysis confirmed that MdSGR2 specifically targets chloroplasts. The transient overexpression of MdSGR2 was found to negatively regulate chlorophyll degradation, leading to the inhibition or deceleration of chlorophyll breakdown, thereby maintaining green coloration in the leaves and peel. Conversely, silencing MdSGR2 positively regulated chlorophyll degradation, resulting in chlorosis in the leaves and peel. These findings offer valuable insights into the regulatory mechanism governing apple fruit coloration and lays a solid foundation for further investigation in this field. Full article

Chronic obstructive pulmonary disease (COPD) is a highly prevalent disease that has become the third leading cause of death worldwide. Cycloastragenol (CAG), which is the genuine sapogenin of the main active triterpene saponins in Astragali radix, is a bioavailable pre-clinical candidate for chronic obstructive pulmonary disease (COPD), and it was investigated in our previous study. In order to progress medical research, it was first efficiently produced on a 2.5-kg scale via Smith degradation from astragaloside IV (AS-IV). Simultaneously, since the impurity profiling of a drug is critical for performing CMC documentation in pre-clinical development, a study on impurities was carried out. As these structures do not contain chromophores and possess weak UV absorption characteristics, HPLC-CAD and UPLC-LTQ-Orbitrap-MS were employed to carry out the quality control of the impurities. Then, column chromatography (CC), preparative thin-layer chromatography (PTLC), and crystallization led to the identification of 15 impurities from CAG API. Among these impurities, compounds 1, 4, 9, 10, 14, and 15 were elucidated via spectroscopic analysis, and 2–3, 5–8, and 11–13 were putatively identified. Interestingly, the new compounds 9 and 14 were rare 10, 19-secocycloartane triterpenoids that displayed certain anti-inflammatory activities against LPS-induced lymphocyte cells and CSE-induced MLE-12 cells. Additionally, a plausible structural transformation pathway of the degradation compounds from CAG or AS IV was proposed. The information obtained will provide a material basis to carry out the quality control and clinical safety assurance of API and related prescriptions. Reasonable guidance will also be provided regarding the compounds with weak UV absorption characteristics. Full article

The easy implementation of ecologically-sound remediation measures for the prompt stabilisation of burned areas may be crucial in Mediterranean forest environments. Manual in situ contour redirection of burned felled logs could aid in soil erosion control and facilitate forest self-regeneration. In this study, a plot-scale runoff/sediment yield survey was conducted in Calabria, Italy, within a Mediterranean pine forest that was affected by an extreme wildfire spanning over 15,000 hectares in the summer of 2021. The hydrological response to 24 rainfall events was analysed after one year of monitoring using nine Wischmeier and Smith 20% sloping plots, which were distributed into three plot-blocks representing different conditions (forested, burned with randomly directed fallen logs, and burned with fallen logs manually redirected along contour lines). The post-fire condition (with felled logs in random positions) exhibited a consistent overall increase (approximately four times) in runoff and sediment yield compared to the pre-fire situation. This degradation effect was mitigated by approximately 30% through the manual redirection of burned logs, which promoted early (three to five weeks) vegetation regeneration (including tree emergence) and enhanced coverage as vegetation spread from the log positions. The results obtained so far provide encouraging insights and warrant further research on steeper slopes and complementary aspects (regulatory, biological, mechanical, economic, etc.). Full article

It is widely recognized that the quality of fruits and vegetables can be altered during transportation and storage. Firmness and loss of weight are the crucial attributes used to evaluate the quality of various fruits, as many other quality attributes are related to these two attributes. These properties are influenced by the surrounding environment and preservation conditions. Limited research has been conducted to accurately predict the quality attributes during transport and storage as a function of storage conditions. In this research, extensive experimental investigations have been conducted on the changes in quality attributes of four fresh apple cultivars (Granny Smith, Royal Gala, Pink Lady, and Red Delicious) during transportation and storage. The study evaluated the weight loss and change in firmness of these apples varieties at different cooling temperatures ranging from 2 °C to 8 °C to assess the impact of storing at these temperatures on the quality attributes. The results indicate that the firmness of each cultivar continuously decreased over time, with the R² values ranging from 0.9489–0.8691 for red delicious, 0.9871–0.9129 for royal gala, 0.9972–0.9647 for pink lady, and 0.9964–0.9484 for granny smith. The rate of weight loss followed an increasing trend with time, and the high R² values indicate a strong correlation. The degradation of quality was evident in all four cultivars, with temperature having a significant impact on firmness. The decline in firmness was found to be minimal at 2 °C, but increased as the storage temperature increased. The loss of firmness also varied among the four cultivars. For instance, when stored at 2 °C, the firmness of pink lady decreased from an initial value of 8.69 kg·cm² to 7.89 kg·cm² in 48 h, while the firmness of the same cultivar decreased from 7.86 kg·cm² to 6.81 kg·cm² after the same duration of storage. Based on the experimental results, a multiple regression quality prediction model was developed as a function of temperature and time. The proposed models were validated using a new set of experimental data. The correlation between the predicted and experimental values was found to be excellent. The linear regression equation yielded an R² value of 0.9544, indicating a high degree of accuracy. The model can assist stakeholders in the fruit and fresh produce industry in anticipating quality changes at different storage stages based on the storage conditions. Full article

Pyrola corbieri Levl has been used to strengthen bones and nourish the kidney (the kidney governs the bone and is beneficial to the brain) by the local Miao people in China. However, the functional components and neurotrophic activity have not been reported. A new acidic homogeneous heteropolysaccharide named LTC-1 was obtained and characterized by periodate oxidation, Smith degradation, partial acid hydrolysis, GC–MS spectrometry, methylation analysis, and Fourier transform infrared spectroscopy, and its molecular weight was 3239 Da. The content of mannuronic acid (Man A) in LTC-1 was 46%, and the neutral sugar was composed of L-rhamnose (L-Rha), L-arabinose (L-Ara), D-xylose (D-Xyl), D-mannose (D-Man), D-glucose (D-Glc) and D-galactose (D-Gal) with a molar ratio of 1.00:3.63:0.86:1.30:6.97:1.30. The main chain of LTC-1 was composed of Glc, Gal, Man, Man A and the branched chain Ara, Glc, Gal. The terminal residues were composed of Glc and Gal. The main chain and branched chains were linked by (1→5)-linked-Ara, (1→3)-linked-Glc, (1→4)-linked-Glc, (1→6)-linked-Glc, (1→3)-linked-Gal, (1→6)-linked-Gal, (1→3, 6)-linked-Man and ManA. Meanwhile, neurotrophic activity was evaluated through PC12 and primary hippocampal neuronal cell models. LTC-1 exhibited neurotrophic activity in a concentration-dependent manner, which significantly induced the differentiation of PC12 cells, promoted the neurite outgrowth of PC12 cells, enhanced the formation of the web architecture of dendrites, and increased the density of dendritic spines in hippocampal neurons and the expression of PSD-95. These results displayed significant neurotrophic factor-like activity of LTC-1, which suggests that LTC-1 is a potential treatment option for neurodegenerative diseases. Full article

Siamese bat catfish (Oreoglanis siamensis Smith, 1993) has been listed as an endangered species, and its abundance has been severely declining due to habitat degradation and overfishing. To establish an appropriate management strategy, it is crucial to gain information about the distribution of this endangered species. As O. siamensis live under rocks in streams, detecting their presence is difficult. Recently, environmental DNA (eDNA)–based detection has been demonstrated to be a valid tool for monitoring rare species, such as O. siamensis. Therefore, this study developed an eDNA assay targeting a 160 bp fragment of the COI region to detect the presence of this species in its natural habitat. An amount of 300 mL of water samples (0.7 μm filtered) were collected from 15 sites in the Mae Klang sub-basin, where this fish species was visually detected at two locations. O. siamensis eDNA was detected at 12 of the 15 sites sampled with varying concentrations (0.71–20.27 copies/mL), including at the sites where this species was visually detected previously. The developed O. siamensis eDNA assay was shown to be effective for detecting the presence of this endangered species in the Klang Phat and Klang Rivers within the Doi Inthanon National Park. Full article

A novel pectic polysaccharide (HPP-1) with high immunomodulatory activity was extracted and isolated from the immature honey pomelo fruit (Citrus grandis). Characterization of its chemical structure indicated that HPP-1 had a molecular weight of 59,024 D. In addition, HPP-1 was primarily composed of rhamnose, arabinose, fucose, mannose, and galactose at a molar ratio of 1.00:11.12:2.26:0.56:6.40. Fourier-transform infrared spectroscopy, periodic acid oxidation, and Smith degradation results showed that HPP-1 had α- and β-glycosidic linkages and 1 → 2, 1 → 4, 1 → 6, and 1 → 3 glycosidic bonds. ¹³C NMR and ¹H NMR analyses revealed that the main glycogroups included 1,4-D-GalA, 1,6-β-D-Gal, 1,6-β-D-Man, 1,3-α-L-Ara, and 1,2-α-L-Rha. Immunomodulatory bioactivity analysis using a macrophage RAW264.7 model in vitro revealed that NO, TNF-α, and IL-6 secretions were all considerably increased by HPP-1. Moreover, RT-PCR results showed that HPP-1-induced iNOS, TNF-α, and IL-6 expression was significantly increased in macrophages. HPP-1-mediated activation in macrophages was due to the stimulation of the NF-κB and MAPK signaling pathways based on western blot analyses. HPP-1 extracted from immature honey pomelo fruit has potential applications as an immunomodulatory supplement. Full article

The fall armyworm (Spodoptera frugiperda, J.E. Smith) is one of the most important agricultural pests in the world and causes serious damage to many significant crops. Insect gut microbiota plays a vital role in host immunity, digestion, and development, helping the higher organism colonize in a new environment. However, the effects of different diets on midgut microbial composition and host immunity in S. frugiperda remain unclear. So far, no reports have compared the gut microbiota of fall armyworm reared using an artificial diet compared to corn leaf in Guangzhou, China. High-throughput 16S rRNA sequencing technology was applied to gain insight into the composition of the gut microbiota of S. frugiperda feeding on corn leaf (field diet) and on a starch-rich artificial diet (lab diet). The fall armyworm gut microbiota was dominated by the bacterial phyla Firmicutes and Proteobacteria. Despite the difference in diet, the core bacterial community was represented by the genus Enterococcus. However, the bacterial community is dominated by a few phylotypes, namely operational taxonomical units 1 (OTU1) (Enterococcus casseliflavus), OTU3 (Enterobacteriaceae), OTU2 (Weissella), and OTU4 (Clostridium), accounting for 97.43% of the total OTUs in the complete dataset. A significant difference was identified in the bacterial communities between the “lab diet” and the “field diet” groups. OTU1 and OTU2 were significantly higher in the “field diet” group, whereas OTU3 and OTU4 were higher in the “lab diet” group. A phylogenetic investigation of the communities by reconstruction of unobserved states (PICRUSt) predicted functional analysis indicates the presence of several genes associated with plant biomass degradation. Importantly, antibiotic-mediated perturbation of the midgut microbial community significantly impacts the expression profile of the important immune genes of the host. Furthermore, the oral reintroduction of gut bacterial isolates (E. mundtii and E. gallinarum) significantly enhances host resistance to AcMNPV infection. Taken together, our results indicate that diet composition is an important driver in shaping insect gut microbiome and immune gene expression, ultimately playing an important role in the pest defense system. Full article