Risk and related factors of elbow musculoskeletal diseases: A nationwide cross-sectional survey in China.

OBJECTIVE: Although studies have shown that Work-related Musculoskeletal Disorders (WMSDs) are common and continue to be a main source of disability and work time loss, there are few reports on elbow WMSDs. The aim of this study was to explore the prevalence and associated factors of elbow WMSDs. METHODS: The valid questionnaires of 57501 workers from 15 different industries nationwide were collected and the Chi-square test and logistic-regression-analysis were applied to reveal the prevalence and risk factors of elbow. RESULTS: The findings indicated that prevalence of elbow WMSDs among workers was 7.3%. The prevalence of elbow WMSDs in toy manufacturing was 21.3%, which significantly higher than that in other industries (P<0.05). Logistic regression analysis showed that aged 40 and above, married, very poor health, left-handed, lifting weights (more than 20 kg each time) , work requiring upper limb or hand force, work in an uncomfortable position, repetitive operations within one minute, using vibrating tools, work involves cold, cool winds or temperature changes, work being completed in the same workshop, work being done outdoors, frequent deal with customers , two shifts, often work overtime, staff shortage, often work for colleagues were the risk factors of elbow WMSDs.The higer education level and monthly income, and enough rest time were the protective factors of elbow WMSDs. CONCLUSION: The toy manufacturing is a high-risk industry for elbow WMSDs. The publicity and education of ergonomics knowledge should be strengthened, and the workers' ergonomics awareness should be improved to reduce the impact of WMSDs.

Emergence, Pattern, and Frequency of Spontaneous Waves in Spreading Epithelial Monolayers.

A striking phenomenon of collective cell motion is that they can exhibit a spontaneously emerging wave during epithelia expansions. However, the fundamental mechanism, governing the emergence and its crucial characteristics (e.g., the eigenfrequency and the pattern), remains an enigma. By introducing a mechanochemical feedback loop, we develop a highly efficient discrete vertex model to investigate the spatiotemporal evolution of spreading epithelia. We find both numerically and analytically that expanding cell monolayers display a power-law dependence of wave frequency on the local heterogeneities (i.e., cell density) with a scaling exponent of -1/2. Moreover, our study demonstrates the quantitative capability of the proposed model in capturing distinct X-, W-, and V-mode wave patterns. We unveil that the phase transition between these modes is governed by the distribution of active self-propulsion forces. Our work provides an avenue for rigorous quantitative investigations into the collective motion and pattern formation of cell groups.

Identification and Characterization of Polyamine Metabolism in Citrus in Response to 'Candidatus Liberibacter asiaticus' Infection.

Citrus Huanglongbing, one of the most devastating citrus diseases, is caused by 'Candidatus Liberibacter asiaticus' (CLas). Polyamines are aliphatic nitrogen-containing compounds that play important roles in disease resistance and are synthesized primarily by two pathways: an arginine decarboxylation pathway and an ornithine decarboxylation pathway. However, it is unclear whether polyamines play a role in the tolerance of citrus to infection by CLas and, if so, whether one or both of the core polyamine metabolic pathways are important. We used high-performance liquid chromatography and ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry to detect the contents of nine polyamine metabolism-related compounds in six citrus cultivars with varying levels of tolerance to CLas. We also systematically detected the changes in polyamine metabolism-related compounds and H2O2 contents and compared the gene expression levels and the activities of enzymes involved in the polyamine metabolic pathway among healthy, asymptomatic, and symptomatic leaves of Newhall navel oranges infected with CLas. The tolerant and moderately tolerant varieties showed higher polyamine metabolism-related compound levels than those of susceptible varieties. Compared with the healthy group, the symptomatic group showed significantly increased contents of arginine, ornithine, γ-aminobutyric acid, and putrescine by approximately 180, 19, 1.5, and 0.2 times, respectively, and upregulated expression of biosynthetic genes. Arginase and ornithine decarboxylase enzyme activities were the highest in the symptomatic group, whereas arginine decarboxylase and agmatine deiminase enzyme activities were the highest in the asymptomatic group. The two polyamine biosynthetic pathways showed different trends with the increase of the CLas titer, indicating that polyamines were mainly synthesized through the arginine decarboxylase pathway in the asymptomatic leaves and were synthesized via the ornithine decarboxylase pathway in symptomatic leaves. These findings provide new insight into the changes in polyamine metabolism in citrus infected with CLas.

Epidemiological study of multi-site WMSDs in the footwear industry in China.

Objectives. This study aimed to identify the prevalence of multi-site work-related musculoskeletal disorders (WMSDs) in Chinese footwear industry workers from 2018 to 2020 and explore the possible influencing factors of WMSDs. Methods. 7106 subjects from 26 large shoe factories in China were investigated using the epidemiological cross-sectional survey method by using the Nordic musculoskeletal questionnaire (NMQ). Results. The total prevalence of WMSDs in the study subjects was 36.8% (2616/7106). Among them, the prevalence of multi-site WMSDs was 26.1% (1858/7106). The proportion of multi-site WMSDs involving two sites was the largest (31.38%). In addition, the results showed that the risk factors of multi-site WMSDs were gender, marital status, long current job experience, poor health, poor working posture, etc. Conclusions. The prevalence of WMSDs was high in the Chinese footwear industry. Based on the results, therefore, it seems necessary to improve work posture, work organization and workenvironment to prevent WMSDs.

Thread-Embedded-in-PDMS Wearable Strain Sensor for Real-Time Monitoring of Human Joint Motion.

Real-time monitoring of human joint motion holds paramount importance in assessing joint health status, preventing and treating joint diseases, and evaluating physical flexibility and coordination. However, traditional strain sensors face limitations in meeting the substantial strain requirements associated with human joint motion. Recently, there has been considerable attention directed towards flexible strain sensors prepared using pliable substrates combined with silk and cotton fabrics. Nonetheless, these sensors exhibit insufficient linearity across the entire measurement range, thereby compromising the predictability of real joint motion based on the output signal. This paper introduced a flexible strain sensor designed to address this issue by offering an enhanced range and high linearity. Specifically, the core wire of the strain sensor was produced by coating a polybutylene terephthalate thread with conductive carbon ink integrated with carbon nanotubes, encapsulated in a thin layer of polydimethylsiloxane in an "S" configuration. The proposed strain sensor maintained excellent linearity within its strain range of 60%, along with advantages such as rapid response speed and robust durability. On-trial tests further affirmed the sensor's capability to effectively monitor the motion of human joints.

Identification of the botanical origins of honey based on nanoliter electrospray ionization mass spectrometry.

The botanical origins of honey are important for the quality control and commercialization of honey. In this research, we established a nanoliter electrospray ionization mass spectrometry (Nano-ESI-MS) method to identify Castanopsis honey (CH), Eurya honey (EH), Dendropanax dentiger honey (DH), and Triadica cochinchinensis honey (TH). In total, 38 compounds were identified based on the collision-induced dissociation experiments by Nano-ESI-MS with 16 differential compounds and 7 quantified as potential differential markers. These four types of honey were distinguished from each other by their mass spectrometry data combined with multivariate analysis with three out of the 7 differential markers, i.e., phenethylamine, tricoumaroyl spermidine, and (+/-)-abscisic acid, identified as potential markers for CH, EH, and DH, respectively. Both the qualitative and quantitative results derived from Nano-ESI-MS were further verified by UPLC-Q/TOF-MS. Our studies provided the significant potential of the Nano-ESI-MS method in the identification of the botanical origins of different kinds of honey.

The prevalence and risk factors of work related musculoskeletal disorders among electronics manufacturing workers: a cross-sectional analytical study in China.

OBJECTIVES: To describe the prevalence of self-reported musculoskeletal disorders among workers in the electronics manufacturing industry and to investigate the relations between work-related musculoskeletal disorders (WMSDs) and work-related variables. METHODS: An interview-based questionnaire survey was carried out in thirty electronics manufacturing factories in China in 2018. The prevalence of WMSDs was estimated using the modified Nordic Musculoskeletal Questionnaire (NMQ). A multivariate logistic regression model was applied to evaluate the effects of risk factors on WMSDs on multiple body parts. RESULTS: The 12-month prevalence of WMSDs among participants was 40.6%, and the common body sites affected were the neck (26.8%), shoulder (22.8%), upper back (14.9%), and lower back (14.8%). The results of logistic regression showed that female adults, > 5 job tenure and work-related factors (including awkward posture, lifting or carrying weights, excessive repetition, prolonged sitting, monotonous work and working under conditions of cold or temperature variations) led to a higher risk of WMSDs on most body parts. Upper back, wrist/hand and elbow pain levels were significantly higher for workers with vibration. However, more frequently, physical exercise was a protective factor against WMSDs on most body parts except the upper back, leg and knee. CONCLUSIONS: The study indicates a high prevalence of musculoskeletal pain among the electronics manufacturing industry in China. Different personal and work factors are related to the occurrence of WMSD on different body parts. Preventive measures should be implemented based on the characteristics of WMSD in the electronic manufacturing industry. Furthermore, the training and intervention guidance of ergonomic hazards in the workplace need to be strengthened by understanding the impact of bad posture, avoiding long-term sitting posture and increasing physical activities.

Chemical composition and anti-inflammatory activities of Castanopsis honey.

Castanopsis is diffusely spread in tropical and subtropical regions and is an important nectar source plant in China. The Castanopsis honey (CH) is characterized by its bitter taste. However, its composition and functions remain unclear. In this study, the physicochemical parameters, chemical composition, and antioxidant capacity of CH were comprehensively investigated, with the anti-inflammatory effects of the Castanopsis honey extract (CHE) evaluated based on the RAW 264.7 cell inflammatory model. The results revealed a high level of quality in CH based on the quality standards. Among a total of 84 compounds identified in CH, 5 high response compounds and 29 phenols were further quantified by UPLC-Q/TOF-MS. The high content of phenylethylamine (117.58 ± 64.81 mg kg-1) was identified as a potential marker of CH. Furthermore, the CH showed evident antioxidant activities, and the anti-inflammatory activities of CHE were observed to inhibit the release of nitric oxide (NO) and reduce the content of tumor necrosis factor alpha (TNF-α) and improve the content of interleukin-10 (IL-10) by regulating the NF-κB pathway. Our study indicates that CH has sound physicochemical properties and biological activities with a high level of quality, providing strong experimental evidence to support the further economic and agricultural development and application of CH.

Prevalence status and associated factors of wrist postural injury in the Chinese occupational population.

Objective: This study investigated the prevalence of wrist injuries in 15 industries and different types of work in China. Study on the associated factors of wrist injuries provides a scientific basis for prevention and treatment of wrist diseases in occupational workers. Methods: A cross-sectional study of musculoskeletal symptoms of related practitioners in 15 industries, including automobile manufacturing, was conducted to retrieve worker demographic information, working wrist posture, and pain conditions. Multivariable binary logistic regression analyses were performed to identify factors associated with work-related musculoskeletal disorders (WMSDs). Results: The prevalence of wrist injuries among the study population was 13.2%. Toy manufacturing, animal husbandry, automobile manufacturing, shoe manufacturing, and biopharmaceutical manufacturing had the highest wrist injury rates at 29.1, 19.1, 14.9, 14.9, and 14.0%, respectively. Among the types of jobs, enamel workers (63.0%), butchers (43.6%), combers (32.5%), welders (31.3%), and scaffolders (26.5%) had the highest prevalence rates. Based on the final multivariate logistic regression analysis: female [odds ratios (OR) = 1.24; 95% confidence interval (CI), 1.15-1.35], 6-10 years of service (OR = 1.11; 95% CI, 1.03-1.18), >10 years of service (OR = 1.15; 95% CI, 1.06-1.25), frequent upward and downward flexion in wrist posture at work (OR = 1.81; 95% CI, 1.84-2.11), and frequent wrist placement on the edge of angular objects increased the OR of injury (OR = 1.52; 95% CI, 1.44-1.61). Need to squeeze objects tightly while working (OR = 1.72; 95% CI, 1.57-1.89), prolonged wrist flexion (OR = 1.86; 95% CI, 1.75-1.97), and work hand position above the shoulder for prolonged periods (OR = 1.11; 95% CI, 1.04-1.19) also suggested the relationship between these factors and the higher prevalence of wrist injury in the workers. The associated factor was physical activity (OR = 0.86; 95% CI, 0.80-0.94). Conclusion: This study suggested the relationship between these factors and the higher prevalence of wrist injury in the toy manufacturing, animal husbandry, automobile manufacturing, and shoe-making industries, enamel workers, butchers, and combers. And are work types that require special attention. Females, working age, physical activity, and abnormal posture of the wrist were factors significantly associated with WMSDs.

Shoulder work-related musculoskeletal disorders and related factors of workers in 15 industries of China: a cross-sectional study.

BACKGROUND: Changes in modern industrial production practices can easily lead to shoulder work-related musculoskeletal disorders (WMSD). The current reports on shoulder WMSD are limited to some industries are less well studied, and the sample size is usually small. This study aimed to describe the prevalence and severity of shoulder WMSD in a large sample of Chinese workers from 15 industries, analyze the possible correlations with sociodemographic and work-related variables, and compare the differences between industries. METHODS: A cross-sectional study was conducted among a sample of 55,749 participants from 252 enterprises in 15 industries throughout China. A Chinese version of the musculoskeletal disease questionnaire was used to collect the demographic factors, shoulder symptoms in past 12 months, and work-related factors including posture-related factors, repetition, vibration, work organization, job control, and environmental factors as independent variables. Descriptive statistics were used, and the binary logistic regression analysis was performed to explore the association between shoulder WMSD and potential demographic and work-related factors. RESULTS: Nearly 35.5% of participants reported shoulder pain and discomfort in the previous 12 months. Biopharmaceutical manufacturing (56.2%), medical services (54.4%), and aviation services (50.1%) were the three industries with the highest prevalence of shoulder WMSD. The pain score of aviation services workers was the highest. The related factors for shoulder WMSD varied among the different industries. CONCLUSION: Our study found a relatively high prevalence of shoulder WMSD in China. There were large differences in the prevalence of shoulder WMSD among industries, and the related factors were particular to each industry. Such information is useful to help occupational health practitioners and policymakers conduct preventive programs to reduce shoulder disorders in these working populations.

Optimization of Thermo-Mechanical Fatigue Life for Eutectic Al-Si Alloy by the Ultrasonic Melt Treatment.

The eutectic cast Al-Si alloys with excellent high-temperature and casting performance are widely used in engine pistons. During frequent starts and stops, the thermo-mechanical fatigue (TMF) is the most important failure cause. Ultrasonic melt treatment (UT) was chosen to compare and investigate the influence of micro-structures on fatigue life and damage mechanisms of as-cast (AC) eutectic Al-Si alloys under TMF loading. After UT, the grain size, primary Si, and intermetallic particles are reduced significantly in the alloy; fatigue life increases obviously. As a result of pilling-up of dislocations, the competitive effects of the critical strain/stress for fatigue crack nucleation can be found. There are two different crack initiation mechanisms under TMF: one is primary Si fracture for AC alloys with limited critical strain/stress for fatigue crack nucleation at fractured Si particles, and the other is primary Si debonding for UT alloys with increasing critical fracture strain/stress. After the crack initiation, the fractured or debonded primary phases provide the advantages for the further development of main cracks for both alloys. The UT alloy (805 ± 253 cycles) has about twice the TMF life of the AC alloy (403 ± 98 cycles). The refinement of micro-structures is instrumental in improving the fatigue resistance and life of TMF for the UT alloy.

Prevalence and risk factors analysis for low back pain among occupational groups in key industries of China.

BACKGROUND: With the acceleration of industrialization and population aging, low back pain (LBP) has become the leading cause of life loss years caused by disability. Thus, it places a huge economic burden on society and is a global public health problem that needs urgent solution. This study aimed to conduct an epidemiological investigation and research on a large sample of workers in key industries in different regions of China, determine the incidence and distribution characteristics of LBP, explore the epidemic law, and provide a reference basis for alleviating global public health problems caused by LBP. METHODS: We adopted a modified epidemiological cross-sectional survey method and a stratified cluster sampling method. All on-duty workers who fulfill the inclusion criteria are taken as the research participants from the representative enterprises in key industries across seven regions: north, east, central, south, southwest, northwest, and northeast China. The Chinese version of the musculoskeletal disease questionnaire, modified by a standardized Nordic questionnaire, was used to collect information, and 57,501 valid questionnaires were received. Descriptive statistics were used, and multivariate logistic regression analysis (p < 0.05) was performed to explore the association between musculoskeletal disorders and potential risk factors. RESULTS: LBP annual incidence among workers in China's key industries is 16.4%. There was a significant difference in LBP incidence among occupational groups across different industries (p < 0.05). The multivariate regression model showed the following as risk factors for LBP: frequent repetitive movements with the trunk, working in the same positions at a high pace, trunk position, frequently turning around with your trunk, often working overtime, lifting heavy loads (i.e., more than 20 kg), education level, staff shortage, working age (years), cigarette smoking, use of vibration tools at work, body mass index, lifting heavy loads (i.e., more than 5 kg), and age (years). Physical exercise, often standing at work, and absolute resting time were protective factors. CONCLUSION: LBP incidence among key industries and workers in China is high. Thus, it is urgent to take relevant measures according to the individual, occupational, and psychosocial factors of LBP to reduce the adverse impact of LBP on workers' health.

SSVEP-Based Brain Computer Interface Controlled Soft Robotic Glove for Post-Stroke Hand Function Rehabilitation.

Soft robotic glove with brain computer interfaces (BCI) control has been used for post-stroke hand function rehabilitation. Motor imagery (MI) based BCI with robotic aided devices has been demonstrated as an effective neural rehabilitation tool to improve post-stroke hand function. It is necessary for a user of MI-BCI to receive a long time training, while the user usually suffers unsuccessful and unsatisfying results in the beginning. To propose another non-invasive BCI paradigm rather than MI-BCI, steady-state visually evoked potentials (SSVEP) based BCI was proposed as user intension detection to trigger the soft robotic glove for post-stroke hand function rehabilitation. Thirty post-stroke patients with impaired hand function were randomly and equally divided into three groups to receive conventional, robotic, and BCI-robotic therapy in this randomized control trial (RCT). Clinical assessment of Fugl-Meyer Motor Assessment of Upper Limb (FMA-UL), Wolf Motor Function Test (WMFT) and Modified Ashworth Scale (MAS) were performed at pre-training, post-training and three months follow-up. In comparing to other groups, The BCI-robotic group showed significant improvement after training in FMA full score (10.05 ± 8.03, p = 0.001), FMA shoulder/elbow (6.2 ± 5.94, p = 0.0004) and FMA wrist/hand (4.3 ± 2.83, p = 0.007), and WMFT (5.1 ± 5.53, p = 0.037). The improvement of FMA was significantly correlated with BCI accuracy (r = 0.714, p = 0.032). Recovery of hand function after rehabilitation of SSVEP-BCI controlled soft robotic glove showed better result than solely robotic glove rehabilitation, equivalent efficacy as results from previous reported MI-BCI robotic hand rehabilitation. It proved the feasibility of SSVEP-BCI controlled soft robotic glove in post-stroke hand function rehabilitation.

Early detection of Huanglongbing with EESI-MS indicates a role of phenylpropanoid pathway in citrus.

Huanglongbing (HLB), a devastating disease for citrus worldwide, is caused by Candidatus Liberibacter asiaticus (CLas). In this study, we employed a novel extractive electrospray ionization-mass spectrometry (EESI-MS) method to analyze the metabolites in leaves of uninfected and HLB-infected Newhall navel orange. The results showed that uninfected and HLB-infected leaves could be readily distinguished based on EESI-MS combined by multivariable analysis. Nine phenolic compounds involved in phenylpropanoid pathway, such as p-coumaric acid, naringin, and apigenin, were principal components to distinguish the leaves of uninfected and HLB-infected Newhall navel orange. Gene expression was also conducted to further explore the molecular mechanism of phenylpropanoid branch pathway in HLB. The expression of genes (4CL, HCT, CHI, CHS, CYP, and C12R) involved in phenylpropanoid branch pathway was increased in asymptomatic and early period of HLB-infected leaves, while decreased in later period of HLB-infected leaves. This study provides a novel method for early detection of citrus HLB and suggests the regulation mechanism of phenylpropanoid pathway in the interaction between citrus and CLas.

Incidence and Risk Factors of the Upper-Limb Musculoskeletal Disorders Among Occupational Groups in Key Industries - China, 2018-2021.

What is already known about this topic?: The burden of illness and economic losses due to upper-limb work-related musculoskeletal disorders (UL-WMSDs) is high; thus, they have become a major global public health problem. At present, the epidemiological characteristics of UL-WMSDs in China's occupational population are still unknown. What is added by this report?: The incidence of UL-WMSDs among key occupational groups in China is 22.5%, with distinct occupational characteristics. What are the implications for public health practice?: This study has primarily determined the occurrence and potential risk factors of UL-WMSDs in key industries in China and provided data support for recommending prevention and control of the occurrence of such diseases in key industries in China, and in facilitating the addition into the China's List of Legal Occupational Diseases.

Epidemiological Data of Work-Related Musculoskeletal Disorders - China, 2018-2020.

WHAT IS ALREADY KNOWN ABOUT THIS TOPIC?: In recent decades, work-related musculoskeletal disorders (WMSDs) have become increasingly prominent and have become an important issue that is of universal concern and an urgent need to be solved in all countries of the world. WHAT IS ADDED BY THIS REPORT?: The top three industries or occupational groups with the highest standardized prevalence rate of WMSDs were flight attendants, medical staff, and vegetable greenhouses in that order. Women workers were 1.5 times more likely to suffer from WMSDs than men workers. WHAT ARE THE IMPLICATIONS FOR PUBLIC HEALTH PRACTICE?: This study has found the prevalence and distribution characteristics of WMSDs in key industries in China. It is urgent to draw up relevant measures to prevent and control occupational populations with WMSDs.

A deep learning-based model for screening and staging pneumoconiosis.

This study aims to develop an artificial intelligence (AI)-based model to assist radiologists in pneumoconiosis screening and staging using chest radiographs. The model, based on chest radiographs, was developed using a training cohort and validated using an independent test cohort. Every image in the training and test datasets were labeled by experienced radiologists in a double-blinded fashion. The computational model started by segmenting the lung field into six subregions. Then, convolutional neural network classification model was used to predict the opacity level for each subregion respectively. Finally, the diagnosis for each subject (normal, stage I, II, or III pneumoconiosis) was determined by summarizing the subregion-based prediction results. For the independent test cohort, pneumoconiosis screening accuracy was 0.973, with both sensitivity and specificity greater than 0.97. The accuracy for pneumoconiosis staging was 0.927, better than that achieved by two groups of radiologists (0.87 and 0.84, respectively). This study develops a deep learning-based model for screening and staging of pneumoconiosis using man-annotated chest radiographs. The model outperformed two groups of radiologists in the accuracy of pneumoconiosis staging. This pioneer work demonstrates the feasibility and efficiency of AI-assisted radiography screening and diagnosis in occupational lung diseases.

Metabolic response of Citrus limon to Asian citrus psyllid infestation revealed by EESI-MS and HPLC.

Asian citrus psyllid (ACP) causes direct and indirect damage to the citrus industry. Extractive electrospray ionization mass spectrometry (EESI-MS) and high performance liquid chromatography (HPLC) were used to detect the metabolites of C. limon leaves at 0, 12, 24, and 72 h after ACP treatment. The EESI-MS results showed that ACP infestation significantly affected metabolites within a short feeding duration with 8 metabolites identified. The metabolites in leaves of these four groups could be distinguished, with 55 peaks showing significant differences including methyl N-methylanthranilate, caffeic acid, and syringic acid. The quantification of 15 phenolic compounds with HPLC-UV method in C. limon leaves after ACP infestation showed that the total content of them reached a peak of 3504.69 µg g-1 at 12 h, with 9 phenolic compounds changing significantly (P < 0.05). A total of 21 metabolites identified in this study were involved in the biosynthesis pathways of flavonoid, flavone and flavonol, isoflavonoid and phenylpropanoid, and the degradation of aminobenzoate. Contents of epicatechin and caffeic acid increased with the feeding time of ACP as detected by both EESI-MS and HPLC. This may be related to plant defense. This study provides novel insights into the biochemical relationship of ACP and its host plants.

Direct identification and metabolomic analysis of Huanglongbing associated with Candidatus Liberibacter spp. in navel orange by MALDI-TOF-MS.

Citrus Huanglongbing (HLB) is one of the most destructive citrus diseases worldwide, and is associated with the phloem-limited plant pathogenic bacteria Candidatus Liberibacter species. However, there is a latency period during which newly infected trees do not show symptoms, creating challenges for the early detection of HLB. In order to establish a method for rapid detection and to assess the metabolite differences between healthy and HLB-affected Newhall navel oranges, we used matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF-MS) to study asymptomatic and symptomatic leaf extracts compared with healthy leaves. The results showed that healthy, asymptomatic, and symptomatic leaves were distinguishable using MALDI-TOF-MS combined with multivariable analysis. Discriminant analysis (DA) results showed that the accuracy of discrimination of the training set and the success rate of cross-validation analysis were both 100%. Blind testing revealed that nine validation samples were correctly classified to their corresponding group. In addition, 32 MS peaks of metabolites had significant differences between healthy and different HLB-affected navel orange leaves. Among 32 MS peaks, the relative content of nine substances showed an upward trend, and 19 metabolites showed a downward trend, including a significant decrease in malate and citrate, with an increase in HLB bacterial populations. Malate and citrate were found to be specifically reduced in infected leaves regardless of whether symptoms appeared. Thus, they could be used as potential biomarkers for early detection of HLB, reducing false-negative results caused by uneven distribution of the HLB bacterial pathogen. This novel method can efficiently differentiate HLB-affected samples from the host population and provide new information for early detection of HLB in citrus. The entire process from metabolite extraction to the collection of mass spectra of citrus leaves was a simple operation, with no need for sterile conditions. We believe this strategy has significant implications for rapid and effective HLB screening. Graphical abstract.

Investigation on Work-Related Musculoskeletal Disorders - China, 2018-2019.

What is already known about this topic? Work-related musculoskeletal disorders (WMSDs) have a high prevalence and seriously harmful, which has attracted extensive attention in various countries in the world. Currently, the occurrence and rules of WMSDs in key industries are not known in China. What is added by this report? The prevalence of WMSDs is relatively high among professional populations in key industries in China, with the most commonly affected body parts concentrated in neck, shoulders, and low back and increasing with age and working years. What are the implications for public health practice? This study determined the prevalence and distribution characteristics of WMSDs in key industries in China and provided scientific evidence to recommend for inclusion of WMSDs in the new revision of the list of occupational diseases in China.