Background The job content of aircraft maintenance workers is complex, with high intensity and high requirements, and they are prone to work-related musculoskeletal disorders (WMSDs), but related research is relatively rare. Objective To investigate the positive rate of WMSDs among aircraft maintenance workers, evaluate ergonomic load, and analyze the risk factors of WMSDs. Methods We used a self-compiled questionnaire for WMSDs and the Quick Exposure Checklist (QEC) to investigate the basic situation, positive rate of WMSDs, and the ergonomic load of 2271 male maintenance workers in 6 departments of an aircraft maintenance company, including airline maintenance, overall overhaul, accessory/landing gear overhaul, engine overhaul, product customization, and power assist. We used a logistic regression model to analyze the risk factors of WMSDs in the neck, shoulder, hand/wrist, and lower back. Results The positive rate of WMSDs in the past 12 months was 70.4% (1598/2271) and the positive rate of WMSDs in different body parts ranged from 6.6% to 49.5%, with the top three parts of lower back, neck, and knee, respectively. There were statistically significant differences in the positive rate among different departments (P<0.05). The average QEC scores for neck, hand/wrist, and back (static) were moderate, while those for shoulder and back (dynamic) were high, and the body part specific positive rate of WMSDs increased with the increase of ergonomic load level. Working years (5-<10 years, ≥20 years), working with back flexed or twisted or side bent (moderately, excessively), high maximum force level exerted by one hand, and feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of lower back pain (OR=1.486, 1.505; 2.151, 3.769; 1.637; 2.110, 2.407; 1.637, 1.794; P<0.05). Working years (15-<20 years, ≥20 years), working with head/neck bent or twisted (occasionally, continuously), feeling difficult (sometimes) and stressful (very) while working were associated with higher risks of neck pain (OR=1.731, 1.586; 3.732, 8.341; 1.633; 1.696; P<0.05). Working years (15-<20 years, ≥20 years), working with hands in a high position (at shoulder or above), very frequent shoulder/arm movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of shoulder pain (OR=1.587, 1.709; 1.299; 1.521; 1.643, 2.239; 1.659, 1.977; P<0.05). Working with wrist at deviated or bent angle, high repetition of similar movements, feeling difficult (sometimes, often) and stressful (moderately, very) while working were associated with higher risks of hand/wrist pain (OR=1.692; 1.670; 1.827, 2.884; 2.190, 2.625; P <0.05) . Physical exercise after work (≥3 times·week⁻¹) was associated with a lower risk of neck pain (OR=0.582, P<0.05). Shift workers were at a lower risk of shoulder pain and hand/wrist pain (OR=0.737 and 0.554, P<0.05). Conclusion The high positive rate of WMSDs symptoms among aircraft maintenance workers is related to individual, occupational ergonomic, and psychological factors, and active prevention and intervention should be taken.

Objective To construct a plasmid reference for the detection of residual DNA from early region 1A(E1A) protein and simian virus 40 large T antigen(SV40LTA), and to explore a digital PCR(dPCR)-based analytical technique for copy number calibration of plasmid reference to quantify plasmid reference accurately, thereby providing a new idea for host cell DNA residual detection in biological products.Methods The plasmid pUC19-E1A-SV40LTA was constructed, and the whole gene was synthesized and then amplified to obtain sufficient reference plasmid. The digital PCR system was employed to determine the copy numbers using double fluorescence channels of E1A and SV40LTA primer-probe sets, respectively.The reference material calibrated by digital PCR was subsequently applied to qPCR to establish a method for detecting the specific E1A and SV40LTA sequences. The developed qPCR assay was systematically validated for plasmid reference linearity, accuracy, limit of quantification(LOQ), precision, specificity, applicability, and stability. Furthermore, the established qPCR system was utilized for the detection of recombinant adenovirus(rAdV) sample and recombinant adeno-associated virus(rAAV) sample.Results The copy numbers of E1A and SV40LTA targets in the plasmid reference were found to be essentially consistent through digital PCR using dual fluorescence channels. The detection values detected by E1A and SV40LTA primer-probe sets were 3. 55 × 109and 3. 48 × 109copies/μL, respectively. The coefficient of variation(CV) of these two values was 1. 42%, and the mean value of 3. 51 × 109copies/μL was taken as the calibration value of digital PCR.The qPCR system established by using digital PCR to calibrate copy number exhibited good linearity, accuracy, LOQ, precision, specificity, applicability and stability, and the recovery rates for rAdV and rAAV samples were between 70% and130%.Conclusion A reference plasmid for detecting E1A and SV40LTA residues in biological products was established,and a more sensitive and accurate digital PCR method was introduced for quantification, which can be used to detect the residual DNA of E1A and SV40LTA in gene therapy products produced with HEK293 and HEK293T as host cells.

As a traditional nutritional and healthy cash crop in China, tea has certain significance in promoting human health and preventing and controlling chronic diseases. Studies have shown that the nutritional health effect of tea is due to its rich functional components, mainly including tea polyphenols, tea pigments, tea polysaccharides, theanine, alkaloids and other bioactive substances. At present, researchers from the academic circles have continuously carried out animal and human experiments on the health effects of various functional components of tea, which has accumulated abundant research data and materials. Based on this, this article reviews the literature on the nutritional and health effects of the main functional components of tea, and adopts the method of evidence-based research to screen and extract relevant data for qualitative and quantitative meta-analysis. Subsequently, the nutritional health effects of the five functional components of tea, namely tea polyphenols, tea pigments, tea polysaccharides, theanine, and alkaloids, are summarized and outlined. Studies have shown that tea polyphenols, tea pigments, tea polysaccharides, theanine and alkaloids have different health effects and are expected to play their unique roles in promoting human health and preventing and controlling diseases.

ObjectiveThis study leverages structural data from antigen-antibody complexes of the influenza A virus neuraminidase (NA) protein to investigate the spatial recognition relationship between the antigenic epitopes and antibody paratopes. MethodsStructural data on NA protein antigen-antibody complexes were comprehensively collected from the SAbDab database, and processed to obtain the amino acid sequences and spatial distribution information on antigenic epitopes and corresponding antibody paratopes. Statistical analysis was conducted on the antibody sequences, frequency of use of genes, amino acid preferences, and the lengths of complementarity determining regions (CDR). Epitope hotspots for antibody binding were analyzed, and the spatial structural similarity of antibody paratopes was calculated and subjected to clustering, which allowed for a comprehensively exploration of the spatial recognition relationship between antigenic epitopes and antibodies. The specificity of antibodies targeting different antigenic epitope clusters was further validated through bio-layer interferometry (BLI) experiments. ResultsThe collected data revealed that the antigen-antibody complex structure data of influenza A virus NA protein in SAbDab database were mainly from H3N2, H7N9 and H1N1 subtypes. The hotspot regions of antigen epitopes were primarily located around the catalytic active site. The antibodies used for structural analysis were primarily derived from human and murine sources. Among murine antibodies, the most frequently used V-J gene combination was IGHV1-12*01/IGHJ2*01, while for human antibodies, the most common combination was IGHV1-69*01/IGHJ6*01. There were significant differences in the lengths and usage preferences of heavy chain CDR amino acids between antibodies that bind within the catalytic active site and those that bind to regions outside the catalytic active site. The results revealed that structurally similar antibodies could recognize the same epitopes, indicating a specific spatial recognition between antibody and antigen epitopes. Structural overlap in the binding regions was observed for antibodies with similar paratope structures, and the competitive binding of these antibodies to the epitope was confirmed through BLI experiments. ConclusionThe antigen epitopes of NA protein mainly ditributed around the catalytic active site and its surrounding loops. Spatial complementarity and electrostatic interactions play crucial roles in the recognition and binding of antibodies to antigenic epitopes in the catalytic region. There existed a spatial recognition relationship between antigens and antibodies that was independent of the uniqueness of antibody sequences, which means that antibodies with different sequences could potentially form similar local spatial structures and recognize the same epitopes.

The excessive accumulation of advanced glycosylation end products(AGEs), the end products of non-enzymatic glycosylation reactions, can be involved in the pathological processes of various ocular diseases through mechanisms such as oxidative stress, inflammatory responses and apoptosis. In this paper, we systematically reviewed the key role of AGEs in diabetic keratopathy, cataract, glaucoma, age-related macular degeneration(ARMD)and diabetic retinopathy(DR). It was found that AGEs activate signalling pathways such as NADPH oxidase, MAPK and NF-κB by binding to the receptor RAGE, leading to reactive oxygen species(ROS)generation, release of inflammatory factors, and vascular endothelial dysfunction, which in turn induces delayed corneal healing, cross-linking of lens proteins, optic nerve degeneration, formation of choroidal neovascularisation(CNV), and blood-retinal barrier(BRB)disruption. For example, in diabetic keratopathy, AGEs delay wound healing via the ROS/NLRP3 inflammatory vesicle axis; in cataract, ascorbic acid-mediated cross-linking of lens proteins due to AGEs directly impairs lens transparency; and in DR, AGEs exacerbate microvascular damage by regulating vasucular endothelial growth factor(VEGF)expression and pericyte apoptosis. In addition, this article discusses the advances and limitations of AGEs detection techniques, such as the potential application of lens AGEscan fluorescence assay in screening for diabetic complications, and the need to develop tissue-specific assays for aqueous humour and vitreous. For therapeutic strategies, the research directions of inhibiting AGEs production, blocking RAGE signalling pathway and developing anti-glycosylation drugs are proposed to emphasise their clinical value in delaying disease progression. This review not only integrates the molecular mechanisms and clinical associations of AGEs in ocular diseases, but also provides a theoretical basis for targeted interventions, which is of great significance in exploring novel diagnostic and therapeutic strategies.

Blue light inactivation technology, particularly at the 405 nm wavelength, has demonstrated distinct and multifaceted mechanisms of action against both Gram-positive and Gram-negative bacteria, offering a promising alternative to conventional antibiotic therapies. For Gram-positive pathogens such as Bacillus cereus, Listeria monocytogenes, and methicillin-resistant Staphylococcus aureus (MRSA), the bactericidal effects are primarily mediated by endogenous porphyrins (e.g., protoporphyrin III, coproporphyrin III, and uroporphyrin III), which exhibit strong absorption peaks between 400-430 nm. Upon irradiation, these porphyrins are photoexcited to generate cytotoxic reactive oxygen species (ROS), including singlet oxygen, hydroxyl radicals, and superoxide anions, which collectively induce oxidative damage to cellular components. Early studies by Endarko et al. revealed that (405±5) nm blue light at 185 J/cm² effectively inactivated L. monocytogenes without exogenous photosensitizers, supporting the hypothesis of intrinsic photosensitizer involvement. Subsequent work by Masson-Meyers et al. demonstrated that 405 nm light at 121 J/cm² suppressed MRSA growth by activating endogenous porphyrins, leading to ROS accumulation. Kim et al. further elucidated that ROS generated under 405 nm irradiation directly interact with unsaturated fatty acids in bacterial membranes, initiating lipid peroxidation. This process disrupts membrane fluidity, compromises structural integrity, and impairs membrane-bound proteins, ultimately causing cell death. In contrast, Gram-negative bacteria such as Salmonella, Escherichia coli, Helicobacter pylori, Pseudomonas aeruginosa, and Acinetobacter baumannii exhibit more complex inactivation pathways. While endogenous porphyrins remain central to ROS generation, studies reveal additional photodynamic contributors, including flavins (e.g., riboflavin) and bacterial pigments. For instance, H. pylori naturally accumulates protoporphyrin and coproporphyrin mixtures, enabling efficient 405 nm light-mediated inactivation without antibiotic resistance concerns. Kim et al. demonstrated that 405 nm light at 288 J/cm² inactivates Salmonella by inducing genomic DNA oxidation (e.g., 8-hydroxy-deoxyguanosine formation) and disrupting membrane functions, particularly efflux pumps and glucose uptake systems. Huang et al. highlighted the enhanced efficacy of pulsed 405 nm light over continuous irradiation for E. coli, attributing this to increased membrane damage and optimized ROS generation through frequency-dependent photodynamic effects. Environmental factors such as temperature, pH, and osmotic stress further modulate susceptibility, sublethal stress conditions (e.g., high salinity or acidic environments) weaken bacterial membranes, rendering cells more vulnerable to subsequent ROS-mediated damage. The 405 nm blue light inactivates drug-resistant Pseudomonas aeruginosa through endogenous porphyrins, pyocyanin, and pyoverdine, with the inactivation efficacy influenced by bacterial growth phase and culture medium composition. Intriguingly, repeated 405 nm exposure (20 cycles) failed to induce resistance in A. baumannii, with transient tolerance linked to transient overexpression of antioxidant enzymes (e.g., superoxide dismutase) or stress-response genes (e.g., oxyR). For Gram-positive bacteria, porphyrin abundance dictates sensitivity, whereas in Gram-negative species, membrane architecture and accessory pigments modulate outcomes. Critically, ROS-mediated damage is nonspecific, targeting DNA, proteins, and lipids simultaneously, thereby minimizing resistance evolution. The 405 nm blue light technology, as a non-chemical sterilization method, shows promise in medical and food industries. It enhances infection control through photodynamic therapy and disinfection, synergizing with red light for anti-inflammatory treatments (e.g., acne). In food processing, it effectively inactivates pathogens (e.g., E. coli, S. aureus) without altering food quality. Despite efficacy against multidrug-resistant A. baumannii, challenges include device standardization, limited penetration in complex materials, and optimization of photosensitizers/light parameters. Interdisciplinary research is needed to address these limitations and scale applications in healthcare, food safety, and environmental decontamination.

Taste is a sensation produced by the reaction of substances in the mouth with taste receptor cells， and a normal taste function is essential for our daily life and health. As receivers of taste molecules， taste receptors include sour， bitter， sweet， salty， and umami receptors， which are mainly distributed in the oral cavity， gastrointestinal tract， respiratory tract epithelium and other organs and play a physiological role. Traditional Chinese medicine （TCM） has five flavors （sour， bitter， sweet， pungent， and salty）， which are closely related to the efficacy. Except the pungent flavor and umami taste receptors， the other five taste receptors correspond to the five flavors in the TCM theory， while the correlations between them have not been studied， such as those between bitter receptors and bitter TCM and between sweet receptors and sweet TCM. This article reviews the research reports on taste receptors in recent years. By analyzing the relationships of taste receptors with five flavors of TCM， signaling mechanisms， and diseases based on "receptor-TCM" correlations， this article puts forward the possibility of combining the TCM theory of five flavors with modern biomedical research， providing a reference for the research on "flavors" in TCM and the correlations between TCM and taste receptors.

Taste is a sensation produced by the reaction of substances in the mouth with taste receptor cells， and a normal taste function is essential for our daily life and health. As receivers of taste molecules， taste receptors include sour， bitter， sweet， salty， and umami receptors， which are mainly distributed in the oral cavity， gastrointestinal tract， respiratory tract epithelium and other organs and play a physiological role. Traditional Chinese medicine （TCM） has five flavors （sour， bitter， sweet， pungent， and salty）， which are closely related to the efficacy. Except the pungent flavor and umami taste receptors， the other five taste receptors correspond to the five flavors in the TCM theory， while the correlations between them have not been studied， such as those between bitter receptors and bitter TCM and between sweet receptors and sweet TCM. This article reviews the research reports on taste receptors in recent years. By analyzing the relationships of taste receptors with five flavors of TCM， signaling mechanisms， and diseases based on "receptor-TCM" correlations， this article puts forward the possibility of combining the TCM theory of five flavors with modern biomedical research， providing a reference for the research on "flavors" in TCM and the correlations between TCM and taste receptors.

Objective: To understand the association between weight-adjusted-waist index (WWI) and cardiopulmonary endurance among middle school students, so as to provide references for the improvement of cardiopulmonary endurance levels in adolescents. Methods: From June 2015 to December 2018 by using the method of purposive sampling, height, weight, waist circumference, and 20 m shuttle-run tests were measured among 44 870 adolescents aged 13-18 from Northeast, North, East, South, Southwest and Northwest of China. The WWI of the adolescents and the maximum oxygen uptake (VO 2max ) were calculated indirectly. The t-test and one way analysis of variance were used for comparison, and the curve regression analysis method was adopted to analyze the relationship between WWI and VO 2max . Results: For Chinese middle school students aged 13-18, the WWI was (9.35±1.02), the number of 20 m shuttle-run was (38.89±18.14) times, and VO 2max was (39.96±5.88) mL/(kg ·min -1 ). The differences of VO 2max between WWI quartile arrays of boys aged 13-18 were statistically significant ( F=15.19, 9.00, 14.97, 20.48, 28.13, 10.13 , P <0.01), girls had the same trend ( F=23.36, 16.61, 33.45, 32.96, 18.23, 19.36, P <0.01). There was an inverted U shaped curve relationship between WWI and cardiopulmonary endurance. When WWI was 8.5, the VO 2max level reached the highest, which was 40.07 mL/(kg ·min -1 ). Compared with girls, WWI in boys had a more significant impact on cardiopulmonary endurance. Conclusion Maintaining optimal WWI levels may enhance adolescents cardiopulmonary endurance.

BACKGROUND:Currently,exercise therapy is an effective non-pharmacological treatment for low back pain,and exercise therapy can maintain lumbar spine stabilization through mechanical-chemical coupling between bones and muscles,but there is no clear description of the research progress and optimal treatment protocols for exercise therapy to relieve chronic non-specific lower back pain through mechanical-chemical coupling. OBJECTIVE:To review the research progress related to the influence of paravertebral muscles on lumbar spine stabilization during exercise therapy through mechanical-chemical coupling,which in turn relieves chronic non-specific lower back pain,as well as the current optimal treatment protocols of exercise therapy for chronic non-specific lower back pain. METHODS:Literature searches were performed in WanFang database,CNKI,VIP,Web of Science,and PubMed database,with search terms of"chronic non-specific low back pain,lumbar spine stabilization,paravertebral muscles,exercise therapy"in Chinese and English.Relevant literature published from database inception to January 2024 was searched and 93 articles were included for final summarization. RESULTS AND CONCLUSION:Exercise therapy can act on the paravertebral muscles and bones through appropriate mechanical stimulation and produce corresponding changes.Exercise therapy is an important intervention for chronic non-specific lower back pain as it improves the quality of the paravertebral muscles,primarily through mechanical-chemical coupling,and thus maintains lumbar spine stabilization for better relief of chronic non-specific lower back pain.However,there are no clear reports on the exact effective protocols for exercise therapy to treat chronic non-specific lower back pain through lumbar spine stabilization.The development of an individualized exercise program is particularly important for the treatment and prognosis of chronic non-specific low back pain.Muscle mass and bone mass of the same individual are closely related,and imaging assessment of paravertebral muscle mass and quantity is important for disease detection and intervention.