Direct and Detailed Site-Specific Glycopeptide Characterization by Higher-Energy Electron-Activated Dissociation Tandem Mass Spectrometry.

Glycosylation is widely recognized as the most complex post-translational modification due to the widespread presence of macro- and microheterogeneities, wherein its biological consequence is closely related to both the glycosylation sites and the glycan fine structures. Yet, efficient site-specific detailed glycan characterization remains a significant analytical challenge. Here, utilizing an Orbitrap-Omnitrap platform, higher-energy electron-activated dissociation (heExD) tandem mass spectrometry (MS/MS) revealed extraordinary efficacy for the structural characterization of intact glycopeptides. HeExD produced extensive fragmentation within both the glycan and the peptide, including A-/B-/C-/Y-/Z-/X-ions from the glycan motif and a-/b-/c-/x-/y-/z-type peptide fragments (with or without the glycan). The intensity of cross-ring cleavage and backbone fragments retaining the intact glycan was highly dependent on the electron energy. Among the four electron energy levels investigated, electronic excitation dissociation (EED) provided the most comprehensive structural information, yielding a complete series of glycosidic fragments for accurate glycan topology determination, a wealth of cross-ring fragments for linkage definition, and the most extensive peptide backbone fragments for accurate peptide sequencing and glycosylation site localization. The glycan fragments observed in the EED spectrum correlated well with the fragmentation patterns observed in EED MS/MS of the released glycans. The advantages of EED over higher-energy collisional dissociation (HCD), stepped collision energy HCD (sceHCD), and electron-transfer/higher-energy collisional dissociation (EThcD) were demonstrated for the characterization of a glycopeptide bearing a biantennary disialylated glycan. EED can produce a complete peptide backbone and glycan sequence coverage even for doubly protonated precursors. The exceptional performance of heExD MS/MS, particularly EED MS/MS, in site-specific detailed glycan characterization on an Orbitrap-Omnitrap hybrid instrument presents a novel option for in-depth glycosylation analysis.

C-Me-graphene: an ideal two-dimensional nodal line semimetal with ultrahigh Young's modulus.

Nodal line semimetal (NLSM) has become a captivating medium for studying varieties of novel quantum phenomena. Here, based on first-principles calculations, we identify a square compound lattice (SCL) structure, namely C-Me-graphene, featuring a NLSM, wherein the nodal line of this configuration resides precisely at the Fermi energy without any extraneous bands in the vicinity, manifesting the quintessential characteristics of an ideal NLSM. As a corollary, utilizing symmetry analysis, we propose that nodal lines can be generated by exploiting the two-dimensional (2D) SCL of carbon. This is because the SCL not only satisfies time-reversal symmetry and inversion symmetry but also conforms to glide mirror symmetry. Additionally, this structure reveals remarkable mechanical attributes, exemplifying the highest Young's modulus within the realm of 2D materials, second only to graphene. Our work not only identifies an ideal carbon-based NLSM but also advances a scheme for crafting NLSMs, which would greatly enrich topological materials with exotic properties.

Exploring the bidirectional causal associations between pain and circulating inflammatory proteins: A Mendelian randomization study.

Multisite chronic pain (MCP) and site-specific chronic pain (SSCP) may be influenced by circulating inflammatory proteins, but the causal relationship remains unknown. To overcome this limitation, two-sample bidirectional Mendelian randomization (MR) analysis was used to analyse data for 91 circulating inflammatory proteins, MCP and SSCP encompassing headache, back pain, shoulder pain, hip pain, knee pain, stomach abdominal pain and facial pain. The primary MR method used was inverse variance weighting, sensitivity analyses included weighted median, MR pleiotropy residual sum and outlier and the Egger intercept method. Heterogeneity was also detected using Cochrane's Q test and leave-one-out analyses. Finally, a causal relationship between 29 circulating inflammatory proteins and chronic pain was identified. Among these proteins, 14 exhibited a protective effect, including MCP (T-cell surface glycoprotein cluster of differentiation 5), headache (4E-binding protein 1 [4EBP1], cluster of differentiation 40, cluster of differentiation 6 and C-X-C motif chemokine [CXCL] 11), back pain (leukaemia inhibitory factor), shoulder pain (fibroblast growth factor [FGF]-5 and interleukin [IL]-18R1), stomach abdominal pain (tumour necrosis factor [TNF]-α), hip pain (CXCL1, IL-20 and signalling lymphocytic activation molecule 1) and knee pain (IL-7 and TNF-ß). Additionally, 15 proteins were identified as risk factors for MCP and SSCP: MCP (colony-stimulating factor 1, human glial cell line-derived neurotrophic factor and IL-17C), headache (fms-related tyrosine kinase 3 ligand, IL-20 receptor subunit α [IL-20RA], neurotrophin-3 and tumour necrosis factor receptor superfamily member 9), facial pain (CXCL1), back pain (TNF), shoulder pain (IL-17C and matrix metalloproteinase-10), stomach abdominal pain (IL-20RA), hip pain (C-C motif chemokine 11/eotaxin-1 and tumour necrosis factor ligand superfamily member 12) and knee pain (4EBP1). Importantly, in the opposite direction, MCP and SSCP did not exhibit a significant causal impact on circulating inflammatory proteins. Our study identified potential causal influences of various circulating inflammatory proteins on MCP and SSCP and provided promising treatments for the clinical management of MCP and SSCP.

Uniportal video-assisted thoracic surgery versus open thoracotomy for chronic pain after surgery: a prospective cohort study.

PURPOSE: The potential of uniportal video-assisted thoracic surgery (U-VATS) to reduce chronic pain after thoracic surgery (CPTS) compared to open thoracotomy (OT) remains unexplored. This prospective study aims to assess the incidence of CPTS following U-VATS or OT and identify associated risk factors. METHODS: Patients undergoing thoracic surgery were recruited from March 2021 to March 2022, categorized by surgical approach (U-VATS vs. OT). Standard clinical protocols for surgery, anesthesia, and analgesia were followed. Pain symptoms were assessed using the Short-form McGill Pain Questionnaire, with follow-ups up to 6 months. Perioperative factors influencing CPTS at 3 months were analyzed through univariate and multivariate methods. RESULTS: A total of 694 patients were analyzed. Acute pain after thoracic surgery (APTS) was significantly less severe in the U-VATS group (p < 0.001). U-VATS patients exhibited a lower incidence of CPTS at 3 months (63.4% vs. 80.1%, p < 0.001), with reduced severity among those experiencing CPTS (p = 0.007) and a decreased occurrence of neuropathic pain (p = 0.014). Multivariate analysis identified OT incision, moderate to severe APTS (excluding moderate static pain at 24 h postoperative), nocturnal surgery, and lung surgery as risk factors for CPTS. CONCLUSION: This study underscores the potential of U-VATS to reduce both the incidence and severity of CPTS at 3 months compared to OT. Furthermore, it highlights risk factors for CPTS, including OT incision, inadequately managed APTS, lung surgery, and nocturnal surgery. These findings emphasize the importance of considering surgical approach and perioperative pain management strategies to mitigate the burden of CPTS.

Dynamically Modulating the Dissymmetry Factor of Circularly Polarized Organic Ultralong Room-Temperature Phosphorescence from Soft Helical Superstructures.

Achieving circularly polarized organic ultralong room-temperature phosphorescence (CP-OURTP) with a high luminescent dissymmetry factor (glum ) is crucial for diverse optoelectronic applications. In particular, dynamically controlling the dissymmetry factor of CP-OURTP can profoundly advance these applications, but it is still unprecedented. This study introduces an effective strategy to achieve photoirradiation-driven chirality regulation in a bilayered structure film, which consists of a layer of soft helical superstructure incorporated with a light-driven molecular motor and a layer of room-temperature phosphorescent (RTP) polymer. The prepared bilayered film exhibits CP-OURTP with an emission lifetime of 805 ms and a glum value up to 1.38. Remarkably, the glum value of the resulting CP-OURTP film can be reversibly controlled between 0.6 and 1.38 over 20 cycles by light irradiation, representing the first example of dynamically controlling the glum in CP-OURTP.

Preterm birth, a consequence of immune deviation mediated hyperinflammation.

Preterm birth represents a multifaceted syndrome with intricacies still present in our comprehension of its etiology. In the context of a semi-allograft, the prosperity from implantation to pregnancy to delivery hinges on the establishment of a favorable maternal-fetal immune microenvironment and a successful trilogy of immune activation, immune tolerance and then immune activation transitions. The occurrence of spontaneous preterm birth could be related to abnormalities within the immune trilogy, stemming from deviation in maternal and fetal immunity. These immune deviations, characterized by insufficient immune tolerance and early immune activation, ultimately culminated in an unsustainable pregnancy. In this review, we accentuated the role of both innate and adaptive immune reason in promoting spontaneous preterm birth, reviewed the risk of preterm birth from vaginal microbiome mediated by immune changes and the potential of vaginal microbiomes and metabolites as a new predictive marker, and discuss the changes in the role of progesterone and its interaction with immune cells in a preterm birth population. Our objective was to contribute to the growing body of knowledge in the field, shedding light on the immunologic reason of spontaneous preterm birth and effective biomarkers for early prediction, providing a roadmap for forthcoming investigations.

Antioxidant and Stress Resistance Properties of Flavonoids from Chinese Sea Buckthorn Leaves from the Qinghai-Tibet Plateau.

The unique ecological environment of the Qinghai-Tibetan Plateau has endowed Chinese sea buckthorn leaves with rich bioactivities. In this study, we investigated the bioactivity and stress resistance mechanisms of flavonoids derived from Chinese sea buckthorn leaves (FCL) native to the Qinghai-Tibet Plateau. Our analysis identified a total of 57 flavonoids, mainly flavonol glycosides, from FCL, of which 6 were novel flavonoids. Isorhamnetin glycosides, quercetin glycosides and kaempferol glycosides were the three most dominant classes of compounds in FCL. In particular, isorhamnetin-3-O-glucoside-7-O-rhamnoside emerged as the most abundant compound. Our results showed that FCL possesses potent antioxidant properties, as evidenced by its ability to effectively scavenge DPPH free radicals and demonstrate ferric reducing antioxidant power (FRAP) and oxygen radical absorbance capacity (ORAC) levels comparable to Trolox, a well-known antioxidant standard. Furthermore, FCL showed remarkable efficacy in reducing reactive oxygen species (ROS) levels and malondialdehyde (MDA) levels while enhancing the activities of key antioxidant enzymes, namely superoxide dismutase (SOD) and catalase (CAT), in Caenorhabditis elegans, a widely used model organism. Mechanistically, we elucidated that FCL exerts its stress resistance effects by modulating of transcription factors DAF-16 and HSF-1 within the insulin/insulin-like growth factor-1 signaling pathway (IIS). Activation of these transcription factors orchestrates the expression of downstream target genes including sod-3, ctl-1, hsp16.2, and hsp12.6, thus enhancing the organism's ability to cope with stressors. Overall, our study highlights the rich reservoir of flavonoids in Chinese sea buckthorn leaves as promising candidates for natural medicines, due to their robust antioxidant properties and ability to enhance stress resistance.

RPN1 promotes the proliferation and invasion of breast cancer cells by activating the PI3K/AKT/mTOR signaling pathway.

Ribophorin I (RPN1), a part of an N-oligosaccharyl-transferase complex, plays a vital role in the development of multiple cancers. However, its biological role in breast cancer has not been completely clarified. The RPN1 expression level was measured in breast cancer tissues and breast cancer cell lines (MCF7) using RT-qPCR. After down-regulating RPN1 expression by shRNA, the effects of RPN1 on the proliferation, migration and invasion of MCF7 cells were examined. Mechanistically, we assessed the effect of RPN1 on the PI3K/ AKT/mTOR signaling pathway. We found that RPN1 level was up-regulated in breast cancer tissues and cells compared with adjacent non-tumor tissues or MCF10A cells. RPN1 knockdown induced apoptosis and attenuated the proliferation, migration, and invasion of MCF7 cells. Moreover, RPN1 knockdown lowered the levels of p-PI3K/PI3K, p-AKT/AKT, and p-mTOR/mTOR, which were rescued by 740Y-P, a PI3K activator. 740Y-P also reversed the effects of RPN1 knockdown on apoptosis, proliferation, migration, and invasion in MCF7 cells. Taken together, RPN1 promotes the proliferation, migration, and invasion of breast cancer cells via the PI3K/AKT/mTOR signaling pathway.

Static Strength Training Method for Type 2 Diabetic Mice.

The treatment of type 2 diabetes mellitus (T2DM) is a major difficulty in improving patient health. Exercise is one of the main interventions for T2DM. Static strength training is one of the key forms of traditional sports in China. Research shows that static strength training is an effective clinical method for T2DM intervention, but there is no experimental device suitable for static training in mice. One of the difficulties in moving from clinical to basic research is to design appropriate experimental devices. In order to further study the mechanism of static training intervention in T2DM, a simple method for making a static training device for mice is introduced in this paper. This device has the advantages of simple operation, cheap material, and high feasibility. Previous studies conducted under this protocol have shown that static training can effectively reduce blood glucose levels and improve the mitochondrial function of skeletal muscle cells in T2DM mice. The purpose of introducing this device is to promote research on the mechanism of traditional exercise in the intervention of T2DM and to lay a foundation for the quantitative intervention of exercise.

The study on mechanical model considering optimal self-adaption in the bottleneck area.

It aims to solve the problem that the evacuation state of pedestrians depicted by the traditional social force model in a crowded multiexit scenario has a relatively large difference with the actual state, especially the 'optimal path' considered by the self-driving force is the problem of shortest path, and the multiexit evacuation mode depicted by the 'herd behavior' is the local optimum problem. Through in-depth analysis of actual evacuation data of pedestrians and causes of problem, a new crowd evacuation optimization model is established in order to effectively improve the simulation accuracy of crowd evacuation in a multi-exit environment. The model obtains the direction of motion of pedestrians using a field model, fully considers the factors such as exit distance, distribution of pedestrians and regional crowding degree, makes a global optimization for the self-driving force in the social force model using a centralized and distributed network model, and makes a local optimization for it using an elephant herding algorithm, so as to establish a new evacuation optimization method for optimal self-adaption in the bottleneck area. The performance status is compared between the improved social force model and the new model by experiments, and the key factors that affect the new model are analyzed in an in-depth manner. The results show that the new model can optimize the optimal path choice at the early stage of evacuation and improve the evacuation efficiency of pedestrians at the late stage, so as to ensure relatively even distribution of pedestrians at each exit, and also make the simulated evacuation process be more real; and the improvement in overall evacuation efficiency is greater when the number of pedestrians to be evacuated is larger. Therefore, the new model provides a method to solve the phenomenon of disorder in overall pedestrian evacuation due to excessive crowd density during the process of multi-exit evacuation.

Pulsed electric field treatment improves the oil yield, quality, and antioxidant activity of virgin olive oil.

Pulsed electric field (PEF) is an innovative technique used to assist in the extraction of vegetable oils. There has been no research on the effects of PEF on virgin olive oil (VOO) quality and antioxidant activity to date. The present study aimed to analyze the effects of PEF on oil yield, quality, and in vitro antioxidant activity of "Koroneiki" extra virgin olive oil. The results show that the PEF treatment increased the oil yield by 5.6%, but had no significant effect on the saponification value, K232, K270, and ∆K value of the VOO. PEF treatment reduced the oleic acid content by 3.12%, but had no significant effect on the content of palmitic acid, linoleic acid, linolenic acid, arachidonic acid, stearic acid, oleic acid, and palmitic acid. After PEF treatment, the levels of total phenolics, total flavonoids, and oleuropein increased by 7.6%, 18.3% and 76%, respectively. There was no significant effect on the levels of 4 phenolic acids (vanillic acid, p-coumaric acid, ferulic acid and cinnamic acid), 2 lignans (lignans and apigenin), hydroxytyrosol, and 3 pigments (lutein, demagnetized chlorophyll, and carotenoids). In addition, PEF treatment significantly increased the content of tocopherols, with α, ß, γ, and δ tocopherols increasing by 9.8%, 10.7%, 13.6% and 38.4%, respectively. The free radical scavenging ability of DPPH and ABTS was also improved. In conclusion, the use of PEF significantly increased the yield of VOO oil as well as the levels of total phenolics, total flavonoids, oleuropein, tocopherol, and in vitro antioxidant activity.

Anti-inflammatory Properties of Tongfeng Li'an Granules in an Acute Gouty Arthritis Rat Model.

OBJECTIVES: To examine the anti-inflammatory properties and underlying mechanisms of Tongfeng Li'an Granules (TFLA), a traditional medicine, in acute gouty arthritis using a rat model. MATERIALS AND METHODS: We identified 55 major compounds in TFLA via ultrahigh-performance liquid chromatography connected to quadrupole time-of-flight mass spectrometry (UPLC-TQF-MS/MS). Databases were employed for the prediction of potential targets, followed by PPI network construction as well as GO and KEGG analyses. After network-pharmacology-based analysis, a rat gouty arthritis model was used to validate the anti-inflammatory mechanism of TFLA. RESULTS: UPLC-TQF-MS/MS and network pharmacology analyses revealed 55 active ingredients and 160 targets of TFLA associated with gouty arthritis, forming an ingredient-target-disease network. The PPI network identified 20 core targets, including TLR2, TLR4, IL6, NFκB, etc. Functional enrichment analyses highlighted the Toll-like receptor signaling pathway as significantly enriched by multiple targets, validated in in vivo experiments. Animal experiments demonstrated that TFLA improved pathological changes in gouty joint synovium, with decreased ankle joint circumference, serum IL6, IL10, and TNFα levels, as well as reduced protein and mRNA expression of NLRP3, TLR2, and TLR4 in ankle joint synovial tissue observed in the middle- and high-dose TFLA and positive control groups compared to the model group (p < 0.05). CONCLUSION: This research elucidated the pharmacological mechanisms of TFLA against gouty arthritis, implicating various ingredients, targets, and signaling pathways. Animal experiments confirmed TFLA's efficacy in alleviating inflammation in acute gouty arthritis by modulating Toll-like receptor signaling and NLRP3 expression.

Decentralized dynamic system for optimal power dispatch in wind farms based on node-dependence nature.

Meeting the power demand from the transmission system operator is an important objective for power dispatch, which introduces a power supply-demand equality constraint coupling all the wind turbines among the wind farm into the optimization problem. For a large-scale wind farm, processing the global equality constraint in a centralized or distributed framework is time-consuming and computationally complex. Here we considered the fast and localized execution issue of the power optimal dispatch problems. A completely decentralized dynamic system was designed to optimize power flow while satisfying the electricity supply constraints. A voltage optimization problem with the global power constraints was decoupled into local wind turbine controllers based on the node-dependence nature, which is an inherent characteristic of wind farms and was fitted to the power sensitivity matrix in this paper. The local optimization problem was solved iteratively using the gradient projection method, and the system converged linearly to the equilibrium point. The simulations for the case studies performed in Simulink demonstrate that the proposed method achieves a near-global optimal performance using only local measurements.

Effect of continuous nursing on treatment compliance and side effect management of coronary heart disease.

BACKGROUND: There are relatively few studies on continuing care of coronary heart disease (CHD), and its research value needs to be further clarified. AIM: To investigate the effect of continuous nursing on treatment compliance and side effect management in patients with CHD. METHODS: This is a retrospective study with patients from January 2021 to 2023. The study was divided into two groups with 30 participants in each group. Self-rating anxiety scale (SAS) and Self-rating depression scale (SDS) were used to assess patients' anxiety and depression, and medical coping questionnaire was used to assess patients' coping styles. The pelvic floor dysfunction questionnaire (PFDI-20) was used to assess the status of pelvic floor function, including bladder symptoms, intestinal symptoms, and pelvic symptoms. RESULTS: SAS score decreased from 57.33 ± 3.01before treatment to 41.33 ± 3.42 after treatment, SDS score decreased from 50.40 ± 1.45 to 39.47 ± 1.57. The decrease of these two indexes was statistically significant (P < 0.05). PFDI-20 scores decreased from the mean 16.83 ± 1.72 before treatment to 10.47 ± 1.3the mean after treatment, which was statistically significant (P < 0.05). CONCLUSION: The results of this study indicate that pioneering research in continuous care of CHD has a positive impact on improving patients' treatment compliance, reducing anxiety and depression levels, and improving coping styles and pelvic floor functional status.

Endothelial RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of ß-catenin and ILK signaling pathways after inflammatory vascular injury.

Endothelial repair is essential for restoring tissue fluid homeostasis following lung injury. R-spondin3 (RSPO3), a secreted protein mainly produced by endothelial cells (ECs), has shown its protective effect on endothelium. However, the specific mechanisms remain unknown. To explore whether and how RSPO3 regulates endothelial regeneration after inflammatory vascular injury, the role of RSPO3 in sepsis-induced pulmonary endothelial injury was investigated in EC-specific RSPO3 knockdown, inducible EC-specific RSPO3 deletion mice, EC-specific RSPO3 overexpression mice, systemic RSPO3-administration mice, in isolated mouse lung vascular endothelial cells (MLVECs), and in plasma from septic patients. Here we show that plasma RSPO3 levels are decreased in septic patients and correlated with endothelial injury markers and PaO2/FiO2 index. Both pulmonary EC-specific knockdown of RSPO3 and inducible EC-specific RSPO3 deletion inhibit pulmonary ECs proliferation and exacerbate ECs injury, whereas intra-pulmonary EC-specific RSPO3 overexpression promotes endothelial recovery and attenuates ECs injury during endotoxemia. We show that RSPO3 mediates pulmonary endothelial regeneration by a LGR4-dependent manner. Except for ß-catenin, integrin-linked kinase (ILK)/Akt is also identified as a novel downstream effector of RSPO3/LGR4 signaling. These results conclude that EC-derived RSPO3 mediates pulmonary endothelial regeneration by LGR4-dependent activation of ß-catenin and ILK signaling pathways after inflammatory vascular injury.

Investigation of α-Fe2O3 catalyst structure for efficient photocatalytic fenton oxidation removal of antibiotics: preparation, performance, and mechanism.

Currently, the surface structure modification of photocatalysts is one of the effective means of enhancing their photocatalytic efficiency. Therefore, it is critically important to gain a deeper understanding of how the surface of α-Fe2O3 photocatalysts influences catalytic activity at the nanoscale. In this work, α-Fe2O3 catalysts were prepared using the solvothermal method, and four distinct morphologies were investigated: hexagonal bipyramid (THB), cube (CB), hexagonal plate (HS), and spherical (RC). The results indicate that the hexagonal bipyramid (THB) exhibits the highest degradation activity towards tetracycline (TC), with a reaction rate constant of k = 0.0969 min-1. The apparent reaction rate constants for the cube (CB), hexagonal plate (HS), and spherical (RC) morphologies are 0.0824, 0.0726, and 0.0585 min-1, respectively. In addition, it has been observed that the enhancement of photocatalytic activity is closely related to the increase in surface area, which provides more opportunities for interactions between Fe2+ and holes. The quenching experiments and electron paramagnetic resonance (EPR) results indicate that the ˙O2, ˙OH and h+ contribute mainly to the degradation of TC in the system. This research contributes to a more comprehensive understanding of catalyst surface alterations and their impact on catalytic performance.

Enhanced sandwich immunoassay based on bivalent nanobody as an efficient immobilization approach for foodborne pathogens detection.

BACKGROUND: Nanobodies (Nbs), which consist of only antigen-binding domains of heavy chain antibodies, have been used in a various range of applications due to their excellent properties. Nevertheless, the size of Nbs is so small that their antigen binding sites may be sterically hindered after random fixation as capture antibodies, thus leading to poor detection performance in immunoassays. To address this problem, we have focused on the multivalent modification of Nbs, wanted to retain the advantage of good stability through enlarging the size of Nbs to a certain extent, while improve its affinity and reduce its influence by spatial orientation. RESULTS: Here, we designed homo- and heterodimeric Nbs based on Nb413 and Nb422 which recognize different epitopes of Salmonella. The affinity of engineered bivalent nanobodies for S. Enteritidis were 2 orders of magnitude higher compared to monovalent Nbs and low to sub-nM KD, as calculated by Scatchard analysis. To further explore the potential of bivalent Nbs for the detection of Salmonella, we established a sandwich ELISA based on bivalent and phage-displayed Nbs (BNb-ELISA) for multiplex Salmonella determination. Compared with monovalent Nb-based ELISA, the limit of detection (LOD) of the BNb-ELISA was shown to increase 7.5-fold to 2.364 × 103 CFU mL-1 for S. Enteritidis. In addition, the feasibility of this approach for S. Enteritidis detection in real samples was evaluated, with recoveries ranging from 73.0 % to 125.6 % and coefficients of variation (CV) below 7.68 %. SIGNIFICANCE AND NOVELTY: In this study, we developed for the first time bivalent Nbs against Salmonella and examined their improved affinity and impact on the performance of ELISA assay. It confirmed the high binding affinity and good ability of dimeric Nbs to reduce the occupation of the binding sites of immobilized antibodies. Thus, the multivalent modification of Nbs was demonstrated to be a promising means to enhance the performance of Nbs-based immunoassays for foodborne pathogens.

Enhancing Nanobody Immunoassays through Ferritin Fusion: Construction of a Salmonella-Specific Fenobody for Improved Avidity and Sensitivity.

Nanobodies (Nbs) serve as powerful tools in immunoassays. However, their small size and monovalent properties pose challenges for practical application. Multimerization emerges as a significant strategy to address these limitations, enhancing the utilization of nanobodies in immunoassays. Herein, we report the construction of a Salmonella-specific fenobody (Fb) through the fusion of a nanobody to ferritin, resulting in a self-assembled 24-valent nanocage-like structure. The fenobody exhibits a 35-fold increase in avidity compared to the conventional nanobody while retaining good thermostability and specificity. Leveraging this advancement, three ELISA modes were designed using Fb as the capture antibody, along with unmodified Nb422 (FbNb-ELISA), biotinylated Nb422 (FbBio-ELISA), and phage-displayed Nb422 (FbP-ELISA) as the detection antibody, respectively. Notably, the FbNb-ELISA demonstrates a detection limit (LOD) of 3.56 × 104 CFU/mL, which is 16-fold lower than that of FbBio-ELISA and similar to FbP-ELISA. Moreover, a fenobody and nanobody sandwich chemiluminescent enzyme immunoassay (FbNb-CLISA) was developed by replacing the TMB chromogenic substrate with luminal, resulting in a 12-fold reduction in the LOD. Overall, the ferritin-displayed technology represents a promising methodology for enhancing the detection performance of nanobody-based sandwich ELISAs, thereby expanding the applicability of Nbs in food detection and other fields requiring multivalent modification.

Identification and Characterization of Hibiscus mutabilis Varieties Resistant to Bemisia tabaci and Their Resistance Mechanisms.

Hibiscus mutabilis, the city flower of Chengdu, is culturally significant and has nutritional and medicinal benefits. However, frequent infestations of Bemisia tabaci have caused economic losses. This study aimed to identify insect-resistant H. mutabilis varieties. Over two years, varieties like Jinqiusong, Zuiyun, and Zuifurong showed moderate to high resistance based on reproductive indices. Assessments of antixenosis and developmental impacts revealed that adult B. tabaci exhibited low selectivity toward these resistant varieties, indicating a strong repellent effect. Gas chromatography-mass spectrometry analysis identified volatile organic compounds, such as alcohols, alkanes, and terpenes. Notably, 2-ethylhexanol and 6-methylheptanol exhibited repellent properties. Using nontargeted metabolomics, this study compared the metabolite profiles of the insect-resistant variety Jinqiusong (JQS), moderately resistant Bairihuacai (BRHC), and highly susceptible Chongbanbai (CBB) post B. tabaci infestation. Fifteen key metabolites were linked to resistance, emphasizing the phenylpropanoid biosynthesis pathway as crucial in defense. These findings offer a theoretical foundation for breeding insect-resistant H. mutabilis varieties and developing eco-friendly strategies against B. tabaci infestations.