Guangdong Province Of China Research Articles

Geographical origin discrimination of Amomi fructus using an ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry-based metabolomics approach combined with antioxidant activity analysis

Background: Amomi fructus as edible and medicinal food can be used as a flavoring in the daily cooking and herbal tea, the consumption of A. fructus is gradually aggregate in recent years. The quality of A. fructus from Yangchun city of Guangdong province in China is familiar as the best and the value is higher than other areas, the flavor and pharmacological activities is mostly affected by its quality. However, geographical origin confusion often occurs in the market, so it is obligatory to develop technology to differentiate the geographical origin of A. fructus. Objectives: The objective of this study is to assess the antioxidant activity of A. fructus and discriminate the geographical origin of A. fructus using nontarget metabolomics technology. Materials and Methods: Ultra-performance liquid chromatography-quadrupole time-of-flight mass spectrometry was used for acquired data in positive ionization modes, principal component analysis, and orthogonal partial least-squares discrimination analysis. The online analysis website Metabo Analyst 4.0 ( https://www.metaboanalyst.ca/ ) was used for the ensuing analysis. A reducing power test, chelating power of ferrous ions test, 1,1-diphenyl-2-picryl-hydrazyl-hydrate assay, and hydroxyl radicals scavenging ability assays were used to assess the differences in antioxidant activity between the samples from the two geographical locations. Results: Eleven differential metabolites were attained, among which eight were established as marker compounds with the greatest contribution to the discernment between the two production areas. The antioxidant activity happens obvious differences due to dissimilar geographical origin. Conclusion: Untargeted metabolomics combined with multivariate statistical analysis is a commanding strategy to extricate the samples from the same species and to comprehend the quality differences from the viewpoint of overall metabolic profile.

Isolation and characterization of a novel chicken astrovirus in China

Chicken astrovirus (CAstV) is associated with kidney disease and visceral gout, runting and stunting syndrome, and white chick hatchery disease, causing economic losses to the poultry industry worldwide. In this study, 55.6% of 36 clinical samples from Guangdong province in China were positive for CAstV, but negative for other common enteric viruses, including avian nephritis virus, infectious bronchitis virus, fowl adenovirus Group I, Newcastle disease virus, chicken parvovirus, reovirus, and rotavirus by PCRs and RT-PCRs. A CAstV strain, named GD202013, was isolated from Guangdong province in south China, and was identified by CAstV RT-PCR. A whole genome sequence analysis demonstrated that GD202013 shares 76.0 to 88.1% identity with 24 reference strains in GenBank. Phylogenetic analysis, based on whole genome and capsid protein, showed that GD202013 is more closely related to 2 US strains (GA2011/US/2011 and 4175/US/2011) belonging to subgroup Bii. Recombination analysis indicated that GD202013 is a recombinant strain formed by 3 strains: a major parent strain CkP5/US/2016, and 2 minor parent strains (GA2011/US/2011 and G059/PL/2014). In addition, the chicken embryo infection experiment demonstrated that GD202013 causes hatchability reduction, growth depression, and death of embryos. Macroscopic and microscopic lesions in the liver, kidney and small intestine were observed in the dead-in-shell embryos. This is the first report of the novel CAstV infection in China.

A Study on the Relationship between Income Change and the Water Footprint of Food Consumption in Urban China

We use a threshold model to analyze the relationship between per capita income and the per capita water footprint of food consumption in the urban Guangdong Province of China, and further simulate the effect of changes in income distribution on the per capita water footprint of food consumption. The income growth of urban residents has a significant positive effect on the per capita water footprint of food consumption, where the effect varies by income stratum. The income elasticity of the per capita water footprint of food consumption for the total sample is 0.45, where the income elasticity of the low-income group (0.75) is greater than that of the high-income group (0.23), indicating that a change of income in the low-income group has a greater effect on water resources. The simulation results show that increasing the income of residents, especially that of the low-income group, significantly increases the water footprint due to food consumption for the whole society. At present, China is in a period of rapid economic growth and urbanization, comprising a period of profound change and sensitive response to the income level of urban and rural residents. Therefore, in order to reduce the effect of food consumption on the environment, sustainable food consumption management strategies should consider group differences. We should correctly guide all kinds of groups to carry out sustainable consumption, advocate healthy and reasonable diet models, reduce animal food consumption, avoid the excessive consumption of food, and strengthen the management of food waste.

Hukou-based rural\u2013urban disparities in maternal health service utilization and delivery modes in two Chinese cities in Guangdong Province

BackgroundMost existing research on rural–urban health inequalities focuses on disparities in service access and health outcomes based on region. This paper examines rural–urban disparities in maternal healthcare utilization and delivery modes based on household registration (hukou) status to understand the role of state institutions in producing healthcare disparities in China.MethodsUtilizing administrative data from the Public Maternal Health Insurance scheme, we analyzed 54,733 live births in City A (2015–2019) and 25,849 live births in City B (2018–2019) in Guangdong Province in China. We constructed regression models using hukou status (rural versus urban) as the explanatory variable.ResultsWhile there is no statistically significant difference in rural and urban mothers’ probability of obtaining the minimum recommended number of prenatal care checkups in City A (OR = 0.990 [0.950, 1.032]), mothers with rural hukou status have a lower probability of obtaining the minimum recommended number of visits in City B than their counterparts with urban hukou (OR = 0.781 [0.740, 0.825]). The probability of delivering in tertiary hospital is lower among mothers with rural hukou than among those with urban hukou in both cities (City A: OR = 0.734 [0.701, 0.769]; City B: OR = 0.336 [0.319, 0.354]). Mothers with rural hukou are more likely to have a Cesarean section than those with urban hukou in both cities (City A: OR = 1.065 [1.027, 1.104]; City B: OR = 1.127 [1.069, 1.189]). Compared with mothers with urban hukou, mothers with rural hukou incurred 4 % (95 % CI [-0.046, -0.033]) and 9.4 % (95 % CI [-0.120, -0.068]) less in total medical costs for those who delivered via Cesarean section and 7.8 % (95 % CI [-0.085, -0.071]) and 19.9 % (95 % CI [-0.221, -0.177]) less for those who delivered via natural delivery in City A and City B, respectively.ConclusionsRural hukou status is associated with younger age, no difference or lower probability of having a minimum number of prenatal checkups, higher likelihood of delivering in nontertiary hospitals, increased Cesarean delivery rates, and lower medical cost for delivery in these two Chinese cities. Evaluating how hukou status influences maternal healthcare in Chinese cities is important for devising targeted public policies to promote more equitable maternal health services.

Power source–power grid coordinated typhoon defense strategy based on multiagent dynamic game theory

A power source–power grid coordinated typhoon defense strategy is proposed in this study to minimize the cost of power grid anti-typhoon reinforcement measures and improve defense efficiency. It is based on multiagent dynamic game theory. This strategy regards a typhoon as a rational gamer that always causes the greatest damage. Together with the grid planner and black start unit (BSU) planner, it forms a multiagent defense–attack–defense dynamic game model naturally. The model is adopted to determine the optimal reinforcements for the transmission lines, black start power capacity, and location. Typhoon Hato, which struck a partial coastal area in Guangdong province in China in 2017, was adopted to formulate a step-by-step model of a typhoon attacking coastal area power systems. The results were substituted into the multiagent defense–attack–defense dynamic game model to obtain the optimal transmission line reinforcement positions, as well as optimal BSU capacity and geographic positions. An effective typhoon defense strategy and minimum load shedding were achieved, demonstrating the feasibility and correctness of the proposed strategy. The related theories and methods of this study have positive significance for the prevention of uncertain large-scale natural disasters.

Binary sparse signal recovery with binary matching pursuit * *This work was partially supported by National Natural Science Foundation of China (Grant No. 11871248, 61907014, 61901160), the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme (2019), Guangdong Major Project of Basic and Applied Basic Research (Grant No. 2019B030302008), and Natural Science Foundation of Guangdong Province of China (Grant

In numerous applications from communications and signal processing, we often need to acquire a K-sparse binary signal from sparse noisy linear measurements. In this work, we first develop an algorithm called binary matching pursuit (BMP) to recover the K-sparse binary signal. According to whether the residual vector is explicitly formed or not at each iteration, we develop two implementations of BMP which are respectively called explicit BMP and implicit BMP. We then analyze their complexities and show that, compared to the batch-orthogonal matching pursuit (OMP), which is the fastest implementation of OMP, the improvements of the explicit and implicit BMP algorithms are respectively n/(2K) and K times when some quantities are pre-computed. Finally, we provide sharp sufficient conditions of stable recovery of the support of the sparse signal using mutual coherence and restricted isometry property of the sensing matrix. Simulation tests indicate that the implicit BMP algorithm is around or more than n/(2K) times faster than batch-OMP with around or more than 20% lower rates of missed detection and false alarm.

Strategic Criticism in Second Language Class

Criticism is one of the important speech acts in class. Some teachers' criticism may threaten students’ face and lower their self-confidence and motivation in L2 learning. “Green Criticism”, which is indirect and friendly, is suggested to establish a harmonious relationship between teachers and students as well as improving teaching efficiency. It can be presented in two forms: verbal criticism and non-verbal criticism: As to verbal criticism, appropriate words like appropriate person deixis, hedges and positive words should be carefully selected to protect students’ self-esteem. Besides, empathetic mood such as passive voice, subjunctive, rising tone and stroking can be utilized to lessen face-threatening acts. Other pragmatic skills including application of request and humor as well as violation of CP are also effective in solving problems occurring in class. As for non-verbal criticism, keeping silent, using eye contact, walking around, changing facial expression and employing gestures are techniques to solve problems in class effectively. Different problems occurring in an English class of 7th grade in a training school in Zhanjiang, Guangdong Province of China are used as examples to illustrate the strategies of criticism.

Impact of Logistics Development on Economic Growth: An Empirical Research from Guangdong Province in China

This paper evaluates the impact of the development of the logistics industry on economic growth based on panel data of 21 cities in Guangdong Province in China from 2007 to 2019. Using the overall entropy method, the comprehensive development index of the logistics industry is constructed to capture the performance of the logistics industry. On this basis, by using Moran’s index, we measure the spatial agglomeration effect of the logistics industry. Furthermore, direct and spatial spillover effects are also obtained. The estimation results of the spatial Durbin model (SDM) reveal that the elasticity coefficient of the effect of the comprehensive development level of the logistics industry on economic growth is 0.2590, which is significant at the 1% level. In addition, the coefficient of the direct effect of the logistics industry on local economic growth is 0.4074, and the coefficient of the spatial spillover effect on the economic growth of the surrounding areas is 0.3596, which are both significant at the 1% level. These results indicate that the development of the logistics industry can not only improve local economic growth but also promote the economic growth of the surrounding regions.

A Mixed-Method Study on Nurses’ Assessment of Post-Stroke Depressive Symptoms

Background: Stroke is the second leading cause of death in the world and the leading cause of death in China. Post-stroke depression is prevalent, affecting approximately one third of stroke survivors at any given time. However, the depressive symptoms of stroke patients are often overlooked in clinical practice. Objective: The aim is to investigate the knowledge, attitudes, and practice status of nurse clinicians on the assessment of post-stroke depressive symptoms and explore the influencing factors, so as to provide empirical evidence for clinical education related to Post-Stroke Depression (PSD) and the development of nursing clinical pathways for screening. Methods: A self-designed questionnaire is used to survey 298 nurse clinicians in Guangdong Province of China. 12 nurses and nurse managers among the study subjects are purposefully invited to participate in semistructured interviews for in-depth discussion about factors affecting the status of assessment. Results: The total scores of the survey of clinical nurses assessing poststroke depression are (84.76±13.255). The scores of knowledge, attitude, and practice of the survey are (25.08±8.975), (33.33±5.483), and (26.35±6.719) respectively. The results of multiple linear regression analysis show that predominate influencing factors of knowledge include position and whether appropriate training is offered by the employer. Nurses’ attitudes toward assessment are influenced by where they worke. Influencing factors for the practice of assessing PSD symptoms include nurses’ positions, participation in training, knowledge level, and attitudes. Conclusion: The total scores of nurse clinicians in assessing the symptoms of PSD are below average. The current practice needs to be improved.

Age-dependence of hypervirulent fowl adenovirus type 4 pathogenicity in specific-pathogen-free chickens

Hypervirulent fowl adenovirus serotype 4 (hvFAdV-4) has emerged as a major pathogen of hepatitis-hydropericardium syndrome (HHS) with increased mortality in chickens, resulting in economic losses to the Chinese poultry industry since June 2015. Here, we isolated a hypervirulent FAdV-4 (hvFAdV-4) strain (designated GD616) from 25-day-old meat-type chickens with severe HHS in Guangdong Province China in June 2017. The whole genome of the strain GD616 shares high homology with those in the recently-reported hvFAdV-4 isolates in China, with natural deletions of ORF19 and ORF27. A comparative analysis of Hexon and Fiber-2 proteins revealed that 2 unique amino acid residues at positions 378 and 453 of the Fiber-2 protein might be associated with virulence due to their occurrences in all the hvFAdV-4 isolates only. To systemically evaluate the effect of age on the susceptibility of chickens to hvFAdV-4, we used this hvFAdV-4 strain to intramuscularly inoculate 7- to 180-day-old specific-pathogen-free chickens for the evaluation of pathogenicity. These results showed that the pathogenicity of the hvFAdV-4 strain GD616 to chickens exhibited age-relatedness, with younger than 59-day-old chickens showing 100% morbidity and mortality, while 180-day-old chickens still exhibited a hydropericardium syndrome-like clinicopathology with 60% morbidity and 20% mortality. These findings enrich the current available knowledge regarding the pathogenicity of the hypervirulent FAdV-4 virus in chickens with a wide range of ages, which assists with the selection of suitable-aged chickens for the evaluation of hvFAdV-4 vaccines.

Guangdong's experience in defeating the COVID-19.

To provide valuable experience for other countries currently fighting the COVID-19 pandemic by systematically analyzing the effects of control policies on coping with COVID-19 in Guangdong Province of China.Integrating qualitative and quantitative methods to systematically analyze the effects of control policies on fighting COVID-19 with official data in Guangdong Province.Between January 19, 2020 and February 26, 2020, Guangdong Province issued 6 critical control policies to cope with COVID-19 and achieved effects in the following 3-phase. 1.Phase 1: from January 19 to February 7, 2020, Guangdong Province issued the following 4 policies: activating the first-level response to public health emergencies; holding press conferences during the epidemic; carrying out grid investigation; and taking the lead in covering the treatment expenses of suspected patients in basic medical insurance. In this phase, the number of confirmed cases increased rapidly and the number of recovered cases increased gradually.2.Phase 2: from February 8 to 14, Guangdong Province issued the following 2 polices: applying Toujie Quwen granules to 30 designated hospitals and launching a registration and report system for the sale of fever and cough drugs. In this phase, the growth trend of confirmed cases had slowed down on February 10 and then increased slowly on February 14. The number of recovered cases increased rapidly on February 10 and then increased rapidly on February 14.3.Phase 3: from February 15 to 26, the increase number of confirmed cases was a small in magnitude on February 20 and then increased slowly on February 26. The number of recovered cases increased rapidly on February 20 and then increased rapidly on February 26.Guangdong Province implemented 6 control policies in 3-phase and finally successfully defeated the COVID-19. In the first phase, the first 4 control policies showed initial effects on COVID-19 epidemic control. In the second phase, the last 2 control policies greatly contributed to containing the COVID-19 epidemic. In the third phase, the 6 control policies completely overcame the COVID-19 in Guangdong Province, China.

Students' experience of online learning during the COVID-19 pandemic: A province-wide survey study.

Online learning is currently adopted by educational institutions worldwide to provide students with ongoing education during the COVID‐19 pandemic. Even though online learning research has been advancing in uncovering student experiences in various settings (i.e., tertiary, adult, and professional education), very little progress has been achieved in understanding the experience of the K‐12 student population, especially when narrowed down to different school‐year segments (i.e., primary and secondary school students). This study explores how students at different stages of their K‐12 education reacted to the mandatory full‐time online learning during the COVID‐19 pandemic. For this purpose, we conducted a province‐wide survey study in which the online learning experience of 1,170,769 Chinese students was collected from the Guangdong Province of China. We performed cross‐tabulation and Chi‐square analysis to compare students’ online learning conditions, experiences, and expectations. Results from this survey study provide evidence that students’ online learning experiences are significantly different across school years. Foremost, policy implications were made to advise government authorises and schools on improving the delivery of online learning, and potential directions were identified for future research into K‐12 online learning. Practitioner notesWhat is already known about this topic Online learning has been widely adopted during the COVID‐19 pandemic to ensure the continuation of K‐12 education.Student success in K‐12 online education is substantially lower than in conventional schools.Students experienced various difficulties related to the delivery of online learning. What this paper adds Provide empirical evidence for the online learning experience of students in different school years.Identify the different needs of students in primary, middle, and high school.Identify the challenges of delivering online learning to students of different age. Implications for practice and/or policy Authority and schools need to provide sufficient technical support to students in online learning.The delivery of online learning needs to be customised for students in different school years.

Priority decision of risk management for Chinese fisheries by using an analytic hierarchy process (AHP) approach

This study aims to (1) identify risk types faced by the Chinese fisheries; and (2) give priority ranks to the risks and their sub-types for better management. For this purpose, data was collected from fishery researchers/experts working in Shandong, Fujian, Liaoning, and Guangdong provinces of China through questionnaire based survey. In total, 33 questionnaires were obtained among which only 25 questionnaires, consistency ratio (CR) value below than 0.1, were employed in this study. Data was statistically analyzed by using the Analytical Hierarchy Process (AHP). Obtained results indicate that Chinese fisheries is facing five diverse risk types, viz ., natural risk, ecological risk, market risk, technical risk, and management risk. The calculated rank and importance of these risks types are management risk (1 and 0.509), ecological risk (2 and 0.220), technical risk (3 and 0.131), natural risk (4 and 0.076), and market risk (5 and 0.063). On the other hand, overfishing is the biggest risk sub-type faced by Chinese fisheries followed by lack of knowledge and hazardous inorganics. Overall, 18 risk sub-types are identified in this study. The estimated rank and importance of top 3 risk sub-types are overfishing (1 and 0.239), lack of knowledge (2 and 0.169), and hazardous inorganics (3 and 0.130).

Factors Predicting Collaborative Problem Solving: Based on the Data From PISA 2015

Collaborative problem solving (CPS) competency is critical in the twenty-first century. The Program for International Student Assessment (PISA) launched a large-scale assessment of CPS competency for the first time in 2015. Beijing, Shanghai, Jiangsu, and Guangdong provinces in China participated the assessment and scored an average of 496, which was slightly lower than the OECD average 500 and ranked 25th among the 51 countries and economies participating in the assessment. Therefore, this research was conducted to dig into the factors predicting students’ CPS competency, and help students improve it. Most research about CPS has fallen into the construction of the CPS framework and the effectiveness of CPS; research focusing on the factors predicting CPS competency is rare. Accordingly, a hierarchical linear model (HLM) was constructed to investigate the factors predicting students’ CPS competency in the current research. The model revealed that there was a large difference of students’ CPS competency among schools. In addition, among student-level variables, gender, grade, ESCS, ICT resources, students’ attitude toward CPS, and teacher unfairness were effective in predicting students’ CPS competency; among school-level variables, school location, schools’ ESCS and the proportion of all teachers fully certified predicted students’ CPS competency positively. The findings implied that in order to enhance students’ CPS competency, CPS competency training should be permeated through all the subjects; schools should employ teachers who are fully qualified; teachers should treat each student fairly; and students should be provided with more ICT resources and etc.

A 1:1 matched case-control study on dietary protein intakes and hip fracture risk in Chinese elderly men and women.

The aim of the study was to investigate the association of dietary protein intakes with hip fracture risk among Chinese elderly. This was a 1:1 age and sex matched cross-sectional study of case-control design among 1070 pairs of elderly Chinese people aged 55 to 80 years. Patients who were newly diagnosed (within 2-week) hip fracture by X-ray were recruited from four hospitals in Guangdong Province of China. Dietary intakes were evaluated by a validated food frequency questionnaire for total protein, protein from different sources, amino acids profiles, and estimated renal acid load in diet. Daily average intakes of total protein were 58.1±27.0 (women) and 65.7±31.8 (men) g/d for cases, and 66.8±21.5 (women) and 72.1±24.4 (men) for controls (p<0.001). Multivariable regression indicated that, compared with the lowest quartile, the highest quartile of consumption of energy adjusted total protein [OR: 0.360 (0.206~0.630) for women and 0.381 (0.153~0.949) for men] and animal protein [0.326 (0.183, 0.560) for women and 0.335 (0.136~0.828) for men] was significantly associated with the lowered risk of hip fracture in a dose-response manner (all p for trend <0.05). A significant hip fracture risk reduction was observed in women with higher intakes of sulfur amino acids [OR: 0.464 (0.286~0.753)] and aromatic amino acids [0.537 (0.326~0.884)] but not in men. Subgroup analysis suggested that these associations were more evident in elderly with lower body mass index and dietary calcium intake less than 400 mg/d. A higher level of protein intake, even substituted for fat, is associated with lowered hip fracture risk.

A new species of Viola (Violaceae) from Guangdong Province, China.

Viola huizhouensis (Violaceae), a new species from Xiangtoushan National Nature Reserve of Guangdong Province in China, is described and illustrated. The new species is most similar to V. guangzhouensis, but it can be easily distinguished by its much stouter rhizome, lack of aerial stem, dense pubescence of the basal pedicel and the whole plant. Our phylogenetic analysis, based on ITS sequences, confirms that the new species belongs to V. sect. Diffusae.

Bioaccessibility of Cd and its Correlation with Divalent Mineral Nutrients in Locally Grown Rice from Two Provinces in China.

Rice and rice products are the main sources of Cd contamination in humans. The total and bioaccessible concentrations of Cd and three divalent nutrients, Mn, Cu, and Zn, in locally grown rice grains from Hunan and Guangdong Provinces in China were investigated. An in vitro physiologically based extraction test method was introduced to evaluate the bioaccessibility of the target metals in the rice grains. The mean concentrations of Cd in the rice grains were 0.245 mg/kg and 0.235 mg/kg from Hunan and Guangdong Provinces, respectively. Large variations were observed in the Cd concentrations, indicating a heterogeneous distribution of Cd contamination throughout the study areas. The bioaccessibility of Cd, Mn, and Zn in the gastrointestinal fractions was significantly lower than that in the gastric fractions. In contrast, the bioaccessibility of Cu at the intestinal phase was detected in the rice grains from both provinces. The correlation analysis showed significant relationships between total Cd concentrations and bioaccessible Cd fractions, indicating that higher total Cd in rice grains always resulted in higher bioaccessible Cd. Consistent correlations in the rice grains were observed between Zn and Mn. However, a lack of correlation was found between Cd and Zn in the current study. Risk assessment according to bioaccessible Cd would significantly reduce the exposure risk to Cd from rice consumption.

Ubiquitin Conjugating Enzyme E2C Correlates with Tumor Microenvironment and Impacts with Patient Prognosis: A Pan-Cancer Analysis

Background: Increasing evidences indicated that tumor microenvironment played a crucial role in cancer initiation and progression. Ubiquitin-conjugating enzyme E2C(UBE2C) was differentially expressed in 33 cancer types. However, the immunological and prognostic roles ofUBE2C across 33 cancers were unclear. Methods: Differentially expressed genes(DEGs) of 29 cancer types were downloaded from GEPIA2 and 4 cancer types were excluded. Furthermore, the gene expression profiles, mutation data and survival data of 33 cancer types were obtained from UCSC Xena. Survival and prognostic analysis, clinical stage relevance, tumor mutational burden(TMB) and tumor microenvironment(TME) relevance analysis and Gene set enrichment analysis(GSEA) of DEGs in 33 cancer types were performed. Findings: UBE2C was identified as the only one DEG in 33 cancer types which was related to Overall survival(OS) in 13 cancer types, disease-specific survival(DSS) in 8 cancer types, disease-free survival(DFS) in 11 cancer types and progression-free survival(PFS) in 14 cancer types. In addition, the higher UBE2C expression level meant terminal clinical stage in 8 cancer types and the expression level of UBE2C was related to TMB in 20 cancer types. Finally, both immune relevance analysis and GSEA indicated that UBE2C played a vital role in immune response of many cancers. Interpretation:UBE2C was differentially expressed in 33 cancer types and related to the pathnogenesis and tumor microenvironment of many cancers, which might be a potential diagnostic and therapeutic biomarker. Funding: This work was supported by the National Natural Science Foundation of China (81472536); the Science and Technology Planning Project of Guangdong Province (2017A020215181;2014A020212440); Project of Educational Commission of Guangdong Province of China (2018KTSCX026); the Scientific Research Planning Project of Southern Medical University (CX2018N016) and the Presidential Foundation of the Nanfang Hospital (2014027;2019Z030). Declaration of Interest: None Ethical Approval: The Nanfang Hospital ethics committee (AF/SC-09/03.2) approved this study.

Early Detection of Metastatic Relapse and Monitoring of Therapeutic Efficacy by a Five Circulating Tumor DNA Methylation Signature in Colorectal Cancer

Purpose: To develop a circulating tumor DNA (ctDNA) methylation signature for early detection of metastatic relapse and surveillance of therapeutic efficacy in stage III CRC. Perimental design: The deferentially methylated locations (DMLs) between 52 normal intestinal mucosa and 134 stage III CRC tissue and between plasma from 96 stage I/II CRC patients and 73 stage IV CRC patients were detected by high-throughput targeted methylation sequencing. CtDNA methylation signature was established by random forest with DMLs shared by plasma and tissue samples. This signature was then applied to predict the risk of metastatic disease recurrence in blood samples from 50 stage III CRC patients and dynamic monitor the recurrence risk in serial blood samples from 4 CRC patients. Results: 2237 and 1185 hypermethylation markers were identified in CRC tissue and plasma from stage IV CRC patients, respectively. Our signature achieved the sensitivity of 84.21% and specificity of 81.81% in distinguishing late CRC from early CRC in the validation cohort. Moreover, this signature yielded high sensitivity (87.5%) and specificity (94.12%) for predicting metastatic disease relapse in a cohort of 50 stage III CRC patients, and could be an independent risk factor for relapse in those patients (HR, 18.7; 95% CI, 5.3-66.2; P = 9.86e-6). The analyses of serial blood samples of CRC showed that this model was more sensitive to monitor treatment response than imaging examination and serum carcinoembryonic antigen (CEA). Conclusions: We identify a ctDNA methylation signature for stratifying risk of recurrence in stage III CRC and non-invasively monitoring treatment response.Statement of translational relevanceWe successfully developed a ctDNA methylation signature for risk assessment of metastatic disease recurrence in stage III CRC patients and surveillance of therapeutic efficacy of CRC. Funding: This work was supported by the National Key R&D program of China (2017YFC1309002), National Natural Science Foundation of China (81672821, 81872041, 81773101, 81802306, 81903002), Natural Science Foundation Key program of Guangdong Province of China (2018B0303110017), Natural Science Foundation of Guangdong Province of China (2018A030310457, 2019A1515011436), Science and Technology Planning Project of Guangdong Province, China (2017B020226005). Declaration of Interest: The authors Jianbing Fan, Xia Li are employees of AnchorDx Medical Co., Ltd., a company that focuses on the development of next generation sequencing diagnostic products for cancer detection using liquid biopsy. All other authors declare no competing financial interest. Ethical Approval: It was approved by the Human Research Ethical Review Board in Southern Hospital of Southern Medical University and Southern Theater General Hospital of Chinese people's Liberation Army.

Impact of the COVID-19 Pandemic on the Economy of China's Guangdong Province in 2020

Impact of the COVID-19 Pandemic on the Economy of China's Guangdong Province in 2020