The complexity of heatwaves impact on terrestrial ecosystem carbon fluxes: Factors, mechanisms and a multi-stage analytical approach

Extreme heatwaves have become more frequent and severe in recent decades, and are expected to significantly influence carbon fluxes at regional scales across global terrestrial ecosystems. Nevertheless, accurate prediction of future heatwave impacts remains challenging due to a lack of a consistent comprehension of intrinsic and extrinsic mechanisms. We approached this knowledge gap by analyzing the complexity factors in heatwave studies, including the methodology for determining heatwave events, divergent responses of individual ecosystem components at multiple ecological and temporal scales, and vegetation status and hydrothermal environment, among other factors. We found that heatwaves essentially are continuously changing compound environmental stress that can unfold into multiple chronological stages, and plant physiology and carbon flux responses differs in each of these stages. This approach offers a holistic perspective, recognizing that the impacts of heatwaves on ecosystems can be better understood when evaluated over time. These stages include instantaneous, post-heatwave, legacy, and cumulative effects, each contributing uniquely to the overall impact on the ecosystem carbon cycle. Next, we investigated the importance of the timing of heatwaves and the possible divergent consequences caused by different annual heatwave patterns. Finally, a conceptual framework is proposed to establish a united foundation for the study and comprehension of the consequences of heatwaves on ecosystem carbon cycle. This instrumental framework will assist in guiding regional assessments of heatwave impacts, shedding light on the underlying mechanisms responsible for the varied responses of terrestrial ecosystems to specific heatwave events, which are imperative for devising efficient adaptation and mitigation approaches.

Two new pregnane glycosides from the root of Cynanchum auriculatum

Two new pregnane glycosides (1 and 2), together with four known ones (3- 6), were isolated from the roots of Cynanchum auriculatum Royle ex Wight (Asclepiadaceae). On the basis of detailed spectroscopic analysis and chemical method, the structures of new compounds were characterized to be metaplexigenin 3-O-β-D-cymaropyranosyl- (1→4)-α-L-diginopyranosyl-(1→4)-β-D-cymaropyranoside (1), metaplexigenin 3-O-α-L-diginopyranosyl-(1→4)-β-D-cymaropyranoside (2). All the isolated compounds (1-6) were tested for their in vitro inhibitory activity against the growth of human colon cancer cell lines HCT-116. Compounds 5 and 6 showed significant cytoxicities with IC50 values of 43.58 µM and 52.21 µM.

[Changes of uterine morphology and endometrial T2 signal intensity in the fibrotic repair secondary to endometrial injury]

Objective: To investigate the value of uterine morphological parameters and endometrial T2 signal intensity (T2-SI) in evaluating the degree of the fibrotic repair secondary to endometrial injury. Methods: From Sep. 2018 to Feb. 2023, this study prospectively enrolled 29 patients with fibrotic repair secondary to severe endometrial injury (severe group), 17 patients with fibrotic repair secondary to mild to moderate endometrial injury (mild to moderate group), and 40 healthy women of reproductive age (control group) in Nanjing Drum Tower Hospital. The length of uterine cavity (LUC), length of cervix and isthmus (LCI), width of upper uterine cavity (WUUC) and width of lower uterine cavity (WLUC) were measured using magnetic resonance imaging. T2-SI of endometrium and subcutaneous fat of buttocks were measured, and endometrial normalized T2-SI (nT2-SI; T2-SI of endometrium/T2-SI of subcutaneous fat of buttocks) was calculated. Statistical analyses of data were performed using one-way analysis of variance, Mann-Whitney U test, intraclass correlation coefficient, Spearman rho test, area under the receiver operating characteristic curve (AUC). Results: LUC, WUUC, WLUC and endometrial nT2-SI of severe group [(19.7±3.5) mm, (26.9±6.4) mm, (7.9±1.4) mm, 0.73±0.11, respectively] were significantly lower than those of the control group (all P<0.01), while LCI and WUUC/LUC [(51.3±7.3) mm and 1.38±0.34] were significantly higher than those of the control group (all P<0.001). LUC and WLUC of severe group were significantly lower than those of mild to moderate group [(32.4±5.1) mm and (8.8±1.2) mm; all P<0.05], while LCI and WUUC/LUC were significantly higher than those of mild to moderate group [(41.8±8.6) mm and 0.94±0.16; all P<0.001]. LUC and endometrial nT2-SI of mild to moderate group were significantly lower than those of the control group [ (32.4±5.1) vs (35.3±3.5) mm, 0.68±0.13 vs 0.80±0.12; all P<0.01]. LUC, WUUC, WLUC and endometrial nT2-SI were significantly negatively correlated to the degree of the fibrotic repair secondary to endometrial injury (Spearman rho:-0.794, -0.441, -0.471 and -0.316, respectively; all P<0.05), while LCI and WUUC/LUC were significantly positively correlated to the degree of the fibrotic repair secondary to endometrial injury (Spearman rho: 0.481 and 0.674, respectively; all P<0.05). LUC and WUUC/LUC showed high value in distinguishing severe group from the control group or mild to moderate group (all AUC>0.9, all P<0.001). Conclusion: As noninvasive and quantitative biomarkers, uterine morphological parameters and endometrial nT2-SI could evaluate the degree of the fibrotic repair secondary to endometrial injury.

Two new chemical constituents from the stem and branch of Tripterygium wilfordii

A chemical investigation of 95% ethanol extract from the stem and branch of Tripterygium wilfordii has resulted in the isolation and characterization of two new compounds, one neolignan (1) and one phenylalanine derivative (2), as well as four known compounds (3-6). The structures of the new compounds were determined based on extensive spectroscopic analyses. The absolute configuration of compound 1 was defined by X-ray crystallographic analyses and electronic circular dichroism calculation. In addition, compounds 2 and 4-6 exhibited inhibitory effects against NO production in LPS-induced RAW 264.7 macrophages with the IC50 value ranging from 3.51 μM to 30.40 μM.

[Effect of Fire-deposited Charcoal on Soil Organic Carbon Pools and Associated Enzyme Activities in a Recently Harvested Pinus massoniana Plantation Subjected to Broadcast Burning]

Charcoal is a carbonaceous particulate matter with a highly aromatic structure produced by incomplete combustion, and it can cause persistent long-term effects on soil ecological functions. In this study, we determined soil organic carbon pools and associated enzyme activities following five years of different charcoal treatments[charcoal removal (B₀), charcoal retained in situ (B₁), and the addition of charcoal removed from B₀(B₂)] and the unburnt control (UB) in a recently harvested Pinus massoniana plantation subjected to broadcast burning. The results showed that dissolved organic carbon (DOC), microbial biomass carbon (MBC), coarse and fine particulate organic carbon (CPOC and FPOC), and recalcitrant carbon (RC) contents were significantly lower in B₁ than those in UB soil (P<0.05). The MBC and FPOC contents of B₂ soil were comparable to those of UB soil, which were significantly higher than those of B₀ soil (P<0.001). There was no difference in MBC/TC between the B₂ and UB soils, whereas MBC/TC was significantly lower in B₀ than in UB soil (P<0.05). β-glucosidase and peroxidase activities of B₀, B₁, and B₂ soils were significantly lower than that of UB soil (P<0.01), and polyphenol oxidase activity was significantly lower in B₀ and B₂ soils than in UB soil (P<0.01). No significant difference in soil TC, DOC, readily oxidized carbon (ROC), CPOC, and RC content as well as associated enzyme activities was observed among the charcoal treatments (P>0.05). Redundancy analysis showed that sucrose and polyphenol oxidase were the key drivers influencing soil organic carbon fractions, accounting for 16.3% and 12.7% of the total variance, respectively. Overall, our findings indicated that fire-deposited charcoal played a positive role in enhancing soil microbial biomass carbon recovery, soil organic carbon accumulation, and stability, highlighting the importance of charcoal in the management of subtropical plantations in the future.

Effect of leaves damaged by Dendrolimus punctatus and insect frass on soil priming effect

Insect herbivory in the forest canopy leads to a large amount of damaged leaves and frass input to soil, with consequence on soil carbon cycle. However, the influence of damaged leaves and frass from insect canopy herbivory on the soil priming effect is unclear. We examined the effects of leaf litter, leaf damage caused by Dendrolimus punctatus, and insect frass on soil priming effect by using the ¹³C natural abundance technique. The results showed that the addition of leaf litter, damaged leaves, and frass significantly increased native soil organic carbon mineralization, producing a positive priming effect. Moreover, significant differences were observed among treatments. The accumulative priming effect induced by frass was the largest, followed by damaged leaves, and that of leaf litter was the smallest. The priming effect was positively correlated with total P, condensed tannin, total phenolic content, and the ratio of condensed tannin to P (condensed tannin/P), and negatively correlated with C/N, lignin/N, C/P, and lignin/P in the early stage of incubation. There was a significant negative correlation between the priming effect and lignin content in the later stage of incubation. Our results indicated that damaged leaves and frass increased the magnitude of positive priming effect, which was influenced by different factors at different incubation stages. Our results would strengthen the understanding in the effects of insect herbivory on soil carbon cycling in forests, and improve the accuracy of the assessment of its effects on forest carbon sink.

Effects of Chinese fir planting and phosphorus addition on soil microbial biomass and extracellular enzyme activities

Plants can alter soil microbial biomass and extracellular enzyme activities related with carbon (C), nitrogen (N), and phosphorus (P), through litter and root exudates, with consequences on soil carbon, nitrogen and phosphorus (P) cycling. However, it is not well known how the changes in soil phosphorus availability affect the relationships between plants and soil microorganisms. In this study, a factorial experiment was conducted to investigate the effects of Chinese fir (Cunninghamia lanceolata) planting and different levels of P addition (0, 1.95, 3.9, 7.8 and 15.6 g P·m^-2·a^-1) on soil microbial biomass and extracellular enzyme activities. The results showed that planting Chinese fir planting significantly altered soil microbial biomass and C- and N- and P-related extracellular enzyme activities, but the effects were dependent on P addition levels. Without P addition, Chinese fir planting significantly reduced soil nutrient availability and pH, which led to the aggravation of P limitation and lower soil microbial biomass. P addition relieved P limitation, and reduced soil acid phosphatase (ACP) activities by 30.0%, 30.5%, 35.3% and 47.1% with the increasing P addition level (1.95, 3.9, 7.8 and 15.6 g P·m^-2·a^-1). Under three P addition levels (1.95, 3.9 and 7.8 g P·m^-2·a^-1), the negative effects of Chinese fir planting on soil microbial growth were alleviated. Under the high P addition level (15.6 g P·m^-2·a^-1), the negative effects of Chinese fir planting on soil microbial growth occurred again due to soil N limitation. Taken together, Chinese fir planting and soil P availability generally affected soil microbial biomass and extracellular enzyme activities, and changed P limitation.

Two new aryltetralin-type lignans from Camellia oleifera husk

Two new aryltetralin-type lignans (1-2) were isolated from the dichloromethane fraction of 95% ethanol extract of Camellia oleifera fruit husk. Their structures were elucidated on the basis of spectroscopic analysis, and the absolute configurations of compounds 1-2 were determined by the comparison of measured ECD curves with the quantum chemical calculated ones. The new compounds were tested for their antioxidant activities and cytotoxicity against three human cancer cell lines (Huh-7, H460 and MCF-7). While compounds 1 and 2 only showed slight DPPH radical scavenging activities with the IC50 values of 38.68 ± 5.02 and 56.62 ± 1.49 μM, respectively.

ARSCP: An antimicrobial residue surveillance cloud platform for animal-derived foods

Antibiotics have been widely used for improving human and animal health and well-being for many decades. However, the enormous antibiotic usage in agriculture especially for livestock leads to considerable quantities of antibiotic residues in associated food products and can reach potentially hazardous levels for consumers. Therefore, timely detection and systematical surveillance on residual antibiotics in food materials are of significance to minimize the negative impact caused by such unwanted antibiotic leftovers. To this end, we constructed a cloud-platform-based system (ARSCP) for comprehensive surveillance of antibiotic residues in food materials. With the system, we collected 126,560 samples from 68 chicken farms across China and detected the antibiotic residues using a rapid detection colorimetric commercial (Explorer 2.0) kit and UPLC-MS/MS. Only 108 (0.085 %) of the samples contained residual antibiotics exceeding the MRLs and all data were subjected to ARSCP system to provide a landscape of antibiotic residues in China. As a proof-of-concept, we provided an overview of residual antibiotics based on data from China, but the system is generally applicable to track and monitor the antibiotic residues globally when the data from other countries are incorporated. We used the combined Explorer 2.0 and MS data to construct ARSCP, an antimicrobial residue surveillance cloud platform for raw chicken samples. ARSCP can be used for rapid detection and real-time monitoring of antibiotic residues in animal food and provides both data management and risk warning functions. This system provides a solution to improve the management of facilities that must monitor antibiotic MRLs in food animal products that can reduce the pollution of antibiotics to the environment.

[The purchase behavior of prepackaged food and its determinants among primary and middle school students in 6 provinces of China]

Objective: To examine the purchase behaviors of prepackaged food and its determinants among primary and middle school students in 6 provinces of China. Methods: A multi-stage sampling strategy was adopted to select 2 499 primary and middle school students and their parents from the eastern region of China(Beijing, Jiangsu Province, Guangdong Province), the northeast region(Heilongjiang Province), the central region(Henan Province) and the western region(Sichuan Province) from July 2020 to March 2021. Socio-demographic characteristics of students and their parents, eating-related behaviors and the purchase behaviors of prepackaged food of students, and parents' attitudes towards students' eating behavior were collected through questionnaire towards students and their parents. The χ² test was conducted to compare the purchase behaviors in different groups of students, and multivariate logistic stepwise regression analysis was used to analyze the determinants among primary and middle school students. Results: The age of 2 499 participants was(12.7±2.5) years. There were 1 272(50.9%) females and 1 279(51.2%) middle school students. About 1 404(56.2%) students bought prepackaged food. The top 6 prepackaged foods bought at least once a week were milk and dairy products(74.6%), baked food(58.7%), beverages(42.8%), puffed food(40.8%), chocolate and candy(39.8%), and nuts and dried fruits(37.5%). The multivariate logistic regression model analysis results showed that compared with primary school students, rural students, non-boarding students, students who did not like snacks and students whose parents paid attention to their children eating snacks, middle school students(OR=3.36, 95%CI:2.73-4.12), urban students(OR=1.33, 95%CI:1.11-1.61), boarding students(OR=2.15, 95%CI:1.66-2.79), students who liked snacks(OR=2.01, 95%CI:1.66-2.43), students whose parents did not pay attention to their children eating snacks(OR=1.27, 95%CI:1.05-1.54) were more likely to buy prepackaged food by themselves. Compared with students whose parents had education level of junior high school and below, students whose parents had education level of undergraduate and above(OR=0.70, 95%CI:0.53-0.92) were less likely to buy prepackaged food by themselves. Compared with students whose family monthly income was less than 5 000 yuan, students whose family monthly income was over 10 000 yuan(OR=0.67, 95%CI:0.52-0.87) were less likely to buy prepackaged food by themselves. Conclusion: Many primary and middle school students buy prepackaged food by themselves in 6 provinces of China. Individual characteristics such as grade, place of residence, boarding status, as well as family environment such as parents' education level, monthly income and concern about children eating snacks are the influencing factors of purchasing prepackaged food.

[Association between the awareness of Nutrition Facts Panel and prepackaged food purchase behavior among residents]

Objective: To explore the association between the cognition of Nutrition Facts Panel and prepackaged food purchase behavior among residents in six provinces in China. Methods: Using a multi-stage sampling method, 3 002 adults aged 18-70 were selected from the western region (Sichuan), eastern region (Guangdong, Jiangsu, Beijing), central region (Henan), and northeastern region (Heilongjiang) of China from July 2020 to March 2021. Socio-demographic characteristics of participants and their cognition of Nutrition Facts Panel and prepackaged food purchase behavior were collected through questionnaire. A multivariate binary logistic regression model was used to analyze the association between cognition of Nutrition Facts Panel and prepackaged food purchase behavior. Results: The age of 3 002 subjects was (42.3±13.4) years, among which 63.8% (1 914) were female, 66.7% knew the Nutrition Facts Panel, 49.8% would read it when purchasing, 30.7% could understand it, and 56.6% (1 699) bought prepackaged food more than once a week. The results of multivariate analysis showed that after adjusting for relevant confounding factors, compared with the participants knowing but not reading the Nutrition Facts Panel, the group knowing and reading was more likely to buy 11 types of prepackaged food at least once a week (all P<0.05). Compared with the participants reading but not understanding the Nutrition Facts Panel, the group reading and understanding was less likely to buy 11 types of prepackaged food at least once a week (all P<0.05). Conclusion: There was a correlation between cognition of Nutrition Facts Panel and prepackaged food purchase behavior among residents.

[Effects of addition of organic carbon with different chemical structure on the fate and accumulation of exogenous carbon in red and sandy soils]

Plant litter input has important influences on soil CO₂ emission and soil organic carbon (SOC) formation in terrestrial ecosystem. However, it is not well known for the fate of carbon when exogenous organic matters with different chemical structures are added to soil with different textures. In this study, we added the uniformly ¹³C-labelled substrates of glucose, starch, and cellulose to red soil and sandy soil, and compared the net ¹³C accumulation and recovery and its proportions in soil releasing CO₂, SOC, dissolved organic carbon (DOC) and microbial biomass carbon (MBC) pools. The results showed that δ¹³C values increased after exogenous substrate additions in CO₂, SOC, DOC, and MBC, and that the peaks of δ¹³C in CO₂ pool appeared delay with increasing chemical structure complexity. The fate of exogenous C and its contributions of different C pools were significantly influenced by exogenous C types, soil types, and incubation times. In sandy soil, the added exogenous C was more mineralized as CO₂, with the net accumulation and recovery of ¹³C in CO₂ pool decreasing in the order of glucose&gt;starch&gt;cellulose. In red soil, more exogenous C was transferred to SOC pool, with the net accumulation and recovery of ¹³C in SOC pool decreasing in the order of glucose&gt;starch&gt;cellulose. Our results implied that the chemical structure of exogenous substrates and soil texture together controlled the fate and accumulation of exogenous organic carbon.

[Effects of addition of leaf litter with different chemical properties on soil organic carbon mineralization and priming effect]

Litter inputs can affect the mineralization of soil organic carbon (SOC). However, it is yet unknown how the input of leaf litter with different chemical properties drives SOC mineralization and priming effect. In this study, ¹³C-labeled leaf litter of six tree species were added to soil cores (10 cm depth) collected from a natural secondary forest in subtropical region. We examined the effects of different leaf litters on total soil CO₂, litter-derived and soil-derived CO₂ emission rates and accumulation and priming effect. We further examined the relationships between litter chemical properties and CO₂ accumulation and priming effect. Our results showed that leaf litter addition increased total soil CO₂ and soil-derived CO₂ emission rates and accumulations, and that there were positive priming effects ranging from 68% to 128%. Soil organic carbon mineralization and priming effects varied among tree species. The Pearson correlation and stepwise multiple linear regression analysis showed that the litter-derived CO₂ accumulation had negative correlation with leaf litter C, P and cellulose concentrations, whereas the soil-derived CO₂ accumulation were positively correlated to litter C:N and lignin:N. The results implied that tree species could influence SOC mineralization and litter-induced priming effect. Thus it could mitigate soil C loss when we afforested plantation with high quality leaf litter in subtropical region.

[Analysis of epidemiological characteristics of pulmonary tuberculosis patients in Fengtai District, Beijing City from 2011 to 2021]

Objective: To analyze the epidemiological characteristics of pulmonary tuberculosis (PTB) in Fengtai District from 2011 to 2021. Methods: A retrospective study was conducted, the data of PTB patients in Fengtai District from 2011 to 2021 were collected in Chinese disease prevention and Control Information System, which included etiological classification, gender, age, occupation, onset time, demographic information etc. the epidemiological characteristics of reported PTB patients was analysis. Results: A total of 10 342 cases of PTB were reported from 2011 to 2021 in Fengtai District, with an average annual reported incidence rate of 42.87/ 100 000. The incidence rate was the highest in 2012(75.89/100 000), and significantly declined from 2013, which declined to 29.70/100 000 in 2017. It showed a slow rise from 2018 to 2021. The difference was statistically significant (χ²=1 471.77,P<0.001).There were 2 975 cases of etiologic positive PTB from 2011 to 2021, and 76 cases of Rifampicin-resistant PTB from 2017 to 2021. The ratio of male cases to female was 1.75, the average annual incidence rate of male (53.94/100 000) was higher, than female(31.57/100 000).(χ²=704.01,P<0.001). Among all age groups, 25-29 years group, 20-24 years group and 30-34 years group had the highest proportion, which were 1 506 cases (14.56%) , 1 292 cases (12.49%) and 1 024 cases (9.90%) respectively. The average annual incidence rate was the lowest in the group less than 10 years old (1.43/100 000), and the highest in the group 85 years old and over (195.20/100 000), the difference was statistically significant(χ²=3164.24, P<0.001). The top occupations from high to low were housework and unemployment (2 917 cases, 28.21%), retirees (2 308 cases, 22.32%), workers (1 047 cases, 10.12%), cadres and staff (950 cases, 9.19%), farmers (860 cases, 8.32%), business services (698 cases, 6.75%), teachers and students (455 cases, 4.40%). Conclusion: From 2011 to 2021, the incidence rate of PTB was decreased from 2012 to 2017, and slowly increased lately in Fengtai District. The epidemiological characteristics of PTB vary in different age and gender.

Undescribed abietane-type diterpenoids and oleanane-type triterpenoids from the stem and branch of Tripterygium wilfordii

Six undescribed abietane-type diterpenoids (tripterydinoids A-F) and five undescribed oleanane-type triterpenoids (tripterytrinoids A-E) were obtained and determined from the stem and branch of Tripterygium wilfordii Hook. f. (Celastraceae). Tripterydinoids A-C possessed the abietane-type diterpenoid skeleton with rare 8, 9-epoxy ring. The structures of undescribed compounds were established by extensive spectroscopic studies [HRESIMS, 1D/2D-NMR and electronic circular dichroism (ECD) calculation]. The absolute configurations of tripterydinoids A, B, E and tripterytrinoid A were defined by X-ray crystallographic analyses. Bioactivity screening indicated that tripterydinoids A-C exhibited potent inhibitory effects against NO release in LPS-activated RAW 264.7 macrophages with IC₅₀ values of 6.93, 4.46 and 2.98 μM, respectively. Meanwhile, tripterydinoids A-D and tripterytrinoids B, C showed moderate and selective cytotoxicities against five human tumor cell lines (A375, Huh7, MCF-7, HCT-116 and NCI-H460).

[The preference for Front-of-Pack Labeling and its association with the understanding of Nutrition Facts Panel among residents aged 18 to 70: results of a survey in 6 provinces of China]

Objective: To investigate the preference for Front-of-Pack Labeling (FOP) and its association with the understanding of the Nutrition Facts Panel among Chinese residents. Methods: A multi-stage sampling strategy was adopted to select 3 002 people aged between 18 and 70 years old from the eastern region of China (Beijing, Jiangsu Province, Guangdong Province), the northeast region (Heilongjiang Province), the central region (Henan Province) and the western region (Sichuan Province) from July 2020 to March 2021. Socio-demographic characteristics of participants and their understanding of the Nutrition Facts Panel and preference for FOP were collected. The χ² test was conducted to compare the preference for FOP in different groups of population, and multivariate logistic regression was used to analyze the association between the preference for FOP and the understanding of the Nutrition Facts Panel. Results: The mean age of 3 002 participants was (42.3±13.4) years, of which 1 914 (63.8%) were females and 69.3% could not understand the Nutrition Facts Panel. About 2 458 respondents (81.9%) suggested that FOP could be promoted. The top three nutrients that should be labeled were sugar (68.4%), salt (68.2%) and total fat (62.4%). The number of participants who believed that the Multiple Traffic Lights (MTL) could be easier to help consumers to quickly choose healthy food, attract attention and provide the most needed information was 1 064 (35.4%), 1 026 (34.2%) and 1 140 (38.0%), respectively. The multivariate logistic regression analysis showed that, compared with the Guideline Daily Amount (GDA) system, participants who could not understand the Nutrition Facts Panel preferred (1) Nutri-Score, Warning labels, and Health logos: Smart Choice in terms of"Which format of FOP could quickly help you choose food more easily?"[OR (95%CI): 2.21 (1.62-3.02), 1.64 (1.22-2.22), 1.79 (1.31-2.45), respectively]; (2) Nutri-Score, Warning labels, and Health logos: Smart Choice in terms of"Which format of FOP could attract your attention the most?"[OR (95%CI): 2.62 (1.92-3.59), 1.96 (1.45-2.66), 2.25 (1.66-3.04), respectively]; and (3) Nutri-Score, Warning labels, and Health logos: Smart Choice in terms of"Which format of FOP could provide you with the most needed information?"[OR (95%CI): 2.33 (1.70-3.21), 2.21 (1.66-2.95), 2.01 (1.50-2.71), respectively]. Conclusion: The residents from six provinces in China have a supportive attitude towards FOP. The interpretive FOP with color information, specific nutrient information and summary indicator can be launched. The nutrition information of sugar, salt and total fat could be prioritized to be labeled on the FOP.

[Investigation and analysis of the implementation status of "Diagnosis and therapy guideline of preterm birth (2014)"]

Objective: To understand the actual situation of the implementation of "Diagnosis and therapy guideline of preterm birth（2014）", "Guideline" for short, by front-line obstetricians, and to provide reference for the further update and supplement of the "Guideline". Methods: This study designed a structured questionnaire for the prominent problems in the prevention and treatment of preterm birth, which was determined by the expert team drafting the "Guideline". In October to November 2021, a cross-sectional survey was conducted among obstetricians, including members of the Perinatal Medicine Branch of Jiangsu Medical Association and the Obstetrics Subgroup,Chinese society of Obstetrics and Gynecology, Chinese Medical Association, on the implementation status of the "Guideline". The recommendations of the "Guideline" were used as standard answers to determine the implementation rate. A total of 328 valid questionnaires were collected. The total score of the questionnaire was 12 points. The questionnaire was divided into low executive ability group (<7 points) and high executive ability group (≥7 points) with a score of 7 as the threshold value, and the differences in baseline information such as hospital grade and professional title between the two groups were compared. Results: The score of 328 obstetricians was (7.6±1.6) points, including 250 (76.2%, 250/328) in the high execution group and 78 (23.8%, 78/328) in the low execution group. The execution rates of "the use of uterine contraction inhibitors for short courses"[97.0% (318/328)], "late umbilical cord breakage after birth of premature infants"[87.8% (288/328)] and "should preterm patients with intact membranes be treated with antibiotics"[86.6% (284/328)] were all over 80%, indicating good implementation. Multiple logistic regression analysis showed that hospital grade and professional title were independent factors influencing the performance of the "Guideline"(all P<0.05), and secondary hospitals had lower scores and worse execution than tertiary hospitals (OR=0.42, 95%CI: 0.23-0.77; P=0.005). Senior titles had higher scores and better execution than junior titles (OR=5.33, 95%CI: 2.35-12.07; P<0.001). When answering the question "gestational week at which premature infants could survive in your hospital", only 3.4% (11/328) answered 22 weeks, and 44.5% (146/328) answered 28 weeks, accounted for the highest proportion. The gestational week of surviving premature infants in tertiary hospitals was earlier than that in secondary hospitals (P<0.05). The gestational week of surviving premature infants answered by senior titles was earlier than that of junior titles (P<0.05). Conclusions: Obstetricians generally have a good implementation of the "Guideline", and their understanding of some recommended clauses in the guidelines needs to be improved. In the future, training of primary hospitals and physicians with junior titles should be strengthened.

[Soil Enzyme Stoichiometric Characteristics of Pinus massoniana Plantations at Different Stand Ages in Mid-subtropical Areas]

Soil enzyme activity is an important index to characterize the nutrient requirements and nutrient limitations of soil microorganisms. In this study, Pinus massoniana plantations of different stand ages (9, 17, 26, 34, and 43 a) in mid-subtropical China were taken as the research object; the activities of β-glucosidase (BG), N-acetyl-β-glucosaminidase (NAG), leucine amino-peptidase (LAP), acid phosphatase (AP), polyphenol oxidase (POX), and peroxidase (POD) were determined; and soil enzyme stoichiometric ratios were also calculated to investigate the soil microbial nutrient limitations of P. massoniana plantation development. The results showed that the activities of BG, NAG, AP, POX, and POD were enhanced with the increase in stand age, and the activity of LAP was the lowest at 17 a, which showed a significant difference and fluctuated among the neighboring stand ages. The soil enzyme C:N:P stoichiometric ratio was 1:1:0.56, which deviated from the global ecosystem enzyme C:N:P stoichiometric ratio (1:1:1). The enzyme C:N increased, whereas the enzyme N:P decreased, with increasing stand age, and both ratios tended to be stable after 17 a. There was no significant difference in enzyme N:P among different stand ages. The vector length of enzyme stoichiometry was not significantly different among the five stand ages. The vector angles increased with the increase in stand ages and tended to be stable after 17 a of stand age, but the angles were less than 45°. Redundancy analysis (RDA) revealed that soil carbon quality index and pH were the main factors influencing soil enzyme activity and the associated stoichiometric ratio. Our findings indicated that P. massoniana plantation soil microorganisms at different growth stages were all subjected to N limitation, and the N limitation was alleviated with the increase in stand age; however, the P requirement was gradually enhanced. Therefore, the management of P. massoniana plantations should take care to increase nitrogen fertilizer at the early growth stage of P. massoniana, and more phosphorus fertilizers need to be applied with nitrogen at the late growth stage in order to maintain the productivity and sustainable development of P. massoniana plantations.

[Study on surface electromyography characteristics of erector spinae muscles at different spinal anteversion angles of the scrapers]

Objective: To simulate and evaluate the scraping and grinding work of workers with different spinal anteversion angles, and to explore the effects of different anteversion angles on the erector spinae muscles of scrapers. Methods: In November 2019, 16 male college student volunteers were recruited to simulate workers' scraping and grinding work. The parameters were 25°, 15 times/min, 15°, 30 times/min, 5°, 60 times/min respectively. The surface electromyography (sEMG) was used to collect the electromyographic signals of the erector spinae muscles, and the surface electromyographic characteristics of the erector spinae muscles were evaluated with Borg Scale. Results: There were significant differences between the maximum voluntary contraction percentage (MVE%) of the left and right erector spinae muscles groups in the three groups with different spinal anteversion angles (F(left)=13.41, P(left)<0.001; F(right)=4.74, P(right)=0.005) , and the EMG amplitude was higher at 25°, 15 times/min. At 15°, 30 times/min, MVE% of the left side was significantly higher than that of the right side (t=2.58, P=0.021) . There was significant difference in the mean power frequency (MPF) of the right erector spinae muscle in the three groups (F=9.42, P<0.001) , but there was no significant difference in the MPF of the left erector spinae muscle (F=0.30, P=0.823) . The fitting line showed that the left erector spinae muscle showed a downward trend at 5°, 60 times/min (t=-5.39, P=0.012) . Conclusion: Scrapers are less likely to be fatigued when the posture is 15°, 30 times/min, but they are more likely to be fatigued when working at 5°, 60 times/min.

[Association between gestational blood pressure and pregnancy induced hypertension or pre-eclampsia]

Objective: To construct the gestational-age-specific blood pressure curve and percentile blood pressure values of pregnant women in Jiangsu Province, and to explore the clinic significance of the blood pressure changes in women whose blood pressure was less than 140/90 mmHg (1 mmHg=0.133 kPa) in each trimester and eventually developed pregnancy induced hypertension (PIH) or pre-eclampsia (PE). Methods: A prospective longitudinal cohort during pregnancy was built. Singleton pregnant women in the first trimester (11-13⁺⁶ weeks) were recruited from July 2017 to September 2020 in Nanjing Drum Tower Hospital, and were followed up in the second trimester (19-23⁺⁶ weeks), the third trimester (30-33⁺⁶ weeks) and approaching the expected date of delivery (35-38⁺⁶ weeks). The Viewpoint 6.0 software was used to record pregnancy-related information. The blood pressure was measured by standard methods in our clinic. Least mean square (LMS) function was performed to fit the gestational-age-specific blood pressure curve and percentile blood pressure values were calculated at every follow-up time point. Logistic regression was applied to calculate the OR for the groups with blood pressure ≥95th percentile (P₉₅). Results: There were 3 728 singleton pregnant women invited in this study, including 3 490 normal pregnant women (93.62%, 3 490/3 728), and 238 pregnant women with PIH or PE (6.38%, 238/3 728). Gestational-age-specific blood pressure curve showed that systolic blood pressure (SBP), diastolic blood pressure (DBP) and mean arterial pressure (MAP) decreased in the second trimester, compared with those in the first and the third trimester, however the fluctuation of blood pressure was low, but regardless of the gestational age, P₉₅ of SBP, DBP and MAP increased by 14, 11 and 11 mmHg respectively, compared with 50th percentile (P₅₀). In the first trimester, the risk of developing PIH or PE finally in pregnant women with blood pressure ≥P₉₅ was 4.36-fold (95%CI: 2.99-6.35) for SBP than women with SBP<P₉₅, 5.22-fold (95%CI: 3.65-7.46) for DBP and 5.14-fold (95%CI: 3.61-7.32) for MAP. When approaching the expected date of delivery, the corresponding risks of the women with blood pressure ≥P₉₅ were 16.76 times, 27.45 and 27.31 times respectively than those of the women with blood pressure <P₉₅. In the first trimester, every 1 mmHg elevation of SBP the risk developing PIH or PE increased by 24% (OR=1.24, 95%CI: 1.15-1.33), 44% (OR=1.44, 95%CI: 1.31-1.59) for DBP and 47% (OR=1.47, 95%CI: 1.33-1.61) for MAP, respectively. The risk in the second trimester was similar to that in the first trimester, and in the third trimester, the risk was further increased. When approaching the expected date of delivery, DBP or MAP increased by 1 mmHg, the risk developing PIH or PE was double; while SBP increased by 1 mmHg, the risk increased by 58%. The areas under the receiver operator characteristic curves of SBP, DBP and MAP were similar for predicting PIH or PE, and the predictive efficiency were all poor. Conclusions: Construction of percentile blood pressure values for pregnant women is helpful in identification of high-risk women of developing PIH or PE. The risk of PIH or PE in pregnant women with blood pressure ≥P₉₅ but <140/90 mmHg has significantly increased compared with women with blood pressure <P₉₅.

[Comparison of diagnostic performance of thyroid autoantibodies and high-resolution ultrasound in euthyroid Hashimoto's thyroiditis]

Objective: To compare the diagnostic performance of thyroid peroxidase antibody (TPOAb), thyroglobulin antibody (TgAb) and high-resolution ultrasound (HRUS) in euthyroid Hashimoto's thyroiditis (HT). Methods: From January 2016 to January 2019, patients with complete data of preoperative thyroid function, TPOAb, TgAb and HRUS who had undergone thyroid surgery treatment at the First Affiliated Hospital with Nanjing Medical University were reviewed. The diagnostic value of different diagnostic methods was compared using histopathology (HP) examination result as the gold standard. Results: The data of 792 patients (217 males and 575 females) was retrospectively collected. The M(Q₁,Q₃)of patients' age was 41(32,52)years and the range was 16-75 years. With HP as the diagnostic gold standard, TPOAb exhibited similar sensitivity (59.3% vs 61.2%, P=0.752), accuracy (85.0% vs 83.6%, P=0.379), area under the receiver operating characteristic curve (AUC) (0.767 vs 0.764, P=0.886) and higher specificity (94.2% vs 91.6%, P=0.033) when compared with TgAb in diagnosing euthyroid HT. They both exhibited a higher sensitivity (59.3% vs 44.5%, P = 0.002; 61.2% vs 44.5%, P<0.001), accuracy (85.0% vs 79.7%, P = 0.001; 83.6% vs 79.7%, P = 0.013) and AUC (0.767 vs 0.684, P<0.001; 0.764 vs 0.684, P<0.001) than HRUS. Compared with each method alone, the sensitivity and AUC of TPOAb combined with TgAb or HRUS were improved. The combination of three methods showed the greatest sensitivity. Concordance analysis demonstrated that TPOAb and HP had a moderate agreement (Kappa=0.580, 95%CI:0.513-0.647,P<0.001). Conclusions: The combination of thyroid antibodies, TPOAb and TgAb, can improve sensitivity, accuracy and AUC of diagnosis in euthyroid Hashimoto's thyroiditis. The two antibodies combined with HRUS exhibited the highest diagnostic performance. Elevated TPOAb showed moderate diagnostic consistency with histopathologic evidence of HT.

[Effects of interpregnancy interval on pregnancy outcomes of subsequent pregnancy: a multicenter retrospective study]

Objective: To explore the effects of interpregnancy interval (IPI) on pregnancy outcomes of subsequent pregnancy. Methods: A multicenter retrospective study was conducted in 21 hospitals in China. Information of age, height, pre-pregnancy weight, IPI, history of diseases, complications of pregnancy, gestational age of delivery, delivery mode, and pregnancy outcomes of the participants were collected by consulting medical records of pregnant women who had two consecutive deliveries in the same hospital during 2011 to 2018. The participants were divided into 4 groups according to IPI:<18 months, 18-23 months, 24-59 months and ≥60 months. According to the WHO's recommendation, with the IPI of 24-59 months group as a reference, to the effects of IPI on pregnancy outcomes of subsequent pregnancy were analyzed. Stratified analysis was further carried out based on age, history of gestational diabetes mellitus (GDM), macrosomia, and premature delivery, to explore the differences in the effects of IPI on pregnancy outcomes among women with different characteristics. Results: A total of 8 026 women were included in this study. There were 423, 623, 5 512 and 1 468 participants in <18 months group, 18-23 months group, 24-59 months group and ≥60 months group, respectively. (1) The age, pre-pregnancy body mass index (BMI), history of cesarean section, GDM, gestational hypertension and cesarean section delivery rate of <18 months group, 18-23 months group, 24-59 months group and ≥60 months group were gradually increased, and the differences were statistically significant (P<0.05). (2) After adjusting for potential confounding factors, compared with women in the IPI of 24-59 months group, the risk of premature delivery, premature rupture of membranes, and oligohydramnios were increased by 42% (OR=1.42, 95%CI: 1.07-1.88, P=0.015), 46% (OR=1.46, 95%CI: 1.13-1.88, P=0.004), and 64% (OR=1.64, 95%CI: 1.13-2.38, P=0.009) respectively for women in the IPI≥60 months group. No effects of IPI on other pregnancy outcomes were found in this study (P>0.05). (3) After stratified by age and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of oligohydramnios for women with advanced age (OR=2.87, 95%CI: 1.41-5.83, P=0.004); and <18 months could increase the risk of premature rupture of membranes for women under the age of 35 (OR=1.59, 95%CI: 1.04-2.43, P=0.032). Both the risk of premature rupture of membranes (OR=1.58, 95%CI: 1.18-2.13, P=0.002) and premature delivery (OR=1.52, 95%CI: 1.07-2.17, P=0.020) were significantly increased in the IPI≥60 months group. After stratified by history of GDM and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would lead to an increased risk of postpartum hemorrhage for women with a history of GDM (OR=5.34, 95%CI: 1.45-19.70, P=0.012) and an increased risk of premature rupture of membranes for women without a history of GDM (OR=1.44, 95%CI: 1.10-1.90, P=0.009). After stratified by history of macrosomia and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months could increase the proportion of cesarean section for women with a history of macrosomia (OR=4.11, 95%CI: 1.18-14.27, P=0.026) and the risk of premature rupture of membranes for women without a history of macrosomia (OR=1.46, 95%CI: 1.12-1.89, P=0.005). After stratified by history of premature delivery and adjusted for confounding factors, compared with women in the IPI of 24-59 months group, IPI≥60 months would significantly increase the risk of premature rupture of membranes for women without a history of premature delivery (OR=1.47, 95%CI: 1.13-1.92, P=0.004). Conclusions: Both IPI≥60 months and <18 months would increase the risk of adverse pregnancy outcomes in the subsequent pregnancy. Healthcare education and consultation should be conducted for women of reproductive age to maintain an appropriate IPI when they plan to pregnant again, to reduce the risk of adverse pregnancy outcomes in the subsequent pregnancy.

Effects of aboveground and belowground litter inputs on the balance of soil new and old organic carbon under the typical forests in subtropical region

Litter is one of the most important factors controlling the accumulation, stabilization, and turnover of soil organic carbon (SOC) in forests. There is a knowledge gap of the impacts of aboveground and belowground litter inputs on the balance of new and old SOC under different forests in subtropical region. We examined the effects of aboveground and belowground litter inputs on SOC turnover using isotopic tracing technique, based on a 3-year C3 plants/C4 soil replacement experiment in natural forest (NF), Masson pine (Pinus massoniana) plantation (PM) and Chinese fir (Cunninghamia lanceolata) plantation (CL). Our results showed that forest types, litter treatments, and sampling time significantly affected SOC contents, δ¹³C, new and old SOC contents. Moreover, there were significant interactions between forest types and litter treatments. Litter input increased SOC content and net SOC increment, with higher sensitivity of NF than CL. Litter inputs decreased soil δ¹³C, with lower values in NF and PM compared to CL. For PM, the new SOC content in belowground litter treatment was significantly higher than that in aboveground litter treatment. The contents of old SOC were lower in belowground litter treatment than aboveground litter treatment in the NF and CL. Above- and below-ground biomass were positively correlated with SOC content and net increment. Belowground litter biomass were positively correlated with soil C/N ratio and new SOC content. Our results implied that belowground litter input had stronger effects on SOC turnover compared to aboveground litter input, with the effects varying among different forests. Our results provided new information on SOC accumulation and on sustainable management of the typical forests in subtropical region.

[Current status and research progress in load assessment methods for occupational low back pain]

With the development of industry, musculoskeletal disorders have become increasingly prominent, and low back pain is one of the major problems. The United States and Germany have already included it in the category of occupational diseases. Therefore, it is extremely important to determine the occupational factors affecting low back pain and evaluate the load level of workers. In this paper, combined with the existing literature, the evaluation methods of the load of low back pain were reviewed, in order to provide reference for the development of prevention strategies of low back pain from the perspective of occupational factors.

[Survey of related factors of maternal venous thromboembolism in nine hospitals of China]

Objective: To investigate and analyze disease status and risk factors of venous thromboembolism (VTE) during pregnancy and puerperium in our country. Methods: Clinical datas were collected from 575 patients diagnosed with VTE during pregnancy and puerperium and hospitalized in nine medical institutions in our country from January 1, 2015 to November 30, 2019, and retrospectively analyzed it's disease status and risk factors. Results: (1) The proportion of VTE in pregnancy and puerperium was 50.6% (291/575) and 49.4% (284/575), respectively. Four patients died, the mortality rate was 0.7% (4/575). The cause of death was pulmonary embolism. (2) The location of VTE during pregnancy and puerperium was mainly in the lower limb vascular (76.2%, 438/575), followed by pulmonary vessels (7.1%, 41/575). (3) In the risk factors of VTE, cesarean section accounted for 32.3% (186/575), maternal advance age accounted for 27.7% (159/575), braking or hospitalization during pregnancy accounted for 13.6% (78/575), other risk factors accounted for more than 5% were previous VTE, obesity, preterm birth, assistant reproductive technology conception and so on, pre-eclampsia and multiple pregnancy accounted for 4.9% (28/575) respectively. In addition, some patients with VTE did not have any of the above risk factors, and the incidence rate was as high as 23.1% (133/575). Conclusions: The occurrence of VTE during pregnancy and puerperium is related to multiple risk factors, and could lead to matemal death, It is very necessary to screen VTE risk factors for all pregnant women, to make corresponding prevention and control measures.

[Intrauterine balloon tamponade combined with temporary abdominal aortic balloon occlusion in the management of women with placenta accreta spectrum:a randomized controlled trial]

Objective: To access the effectiveness and safety of the intrauterine balloon tamponade verse gauze packing combined with temporary abdominal aortic balloon occlusion in the management of placenta accreta spectrum (PAS). Methods: This was an open-label, randomized controlled trial conducted in Nanjing Drum Tower Hospital. The patients suspected with PAS for uterine preservation surgery under the multidisciplinary team care were recruited between Aug 2015 and Jan 2018. When bleeding could not be achieved after fetus delivered, and a temporary abdominal aortic balloon occlusion and the compression sutures as needed, the women were randomly allocated 1∶1 into balloon tamponade (n=81) or gauze packing (n=80) group. The primary outcome was successful bleeding arrests by avoiding second line surgeries. The secondary outcomes included the volume of blood loss during and after cesarean section, the rate of PPH, incidence and amount of blood transfusion, hysterectomy, postpartum pain, ICU admission, need for re-laparotomy, and the length of hospital stay, readmission, and interventional radiology complications. Results: All the women [100% (81/81)] in the balloon group were obtained hemostasis without further intervention, significantly higher than 88% (70/80) in the gauze group (P=0.001). Before uterine tamponade, blood loss were 820 ml (620-1 230) ml and 850 ml (605-1 442) ml, while placenta bed were sutured in 96%（78/81, 77/80） respectively (P>0.05).The proportion of blood loss≥1 000 ml was higher in the gauze group than that in the balloon group (P=0.006). Maternal adverse events involving total blood loss, puerperal morbidity and postpartum pain occurred more frequently in the gauze group (P<0.05). The following outcome showed no statistically significant difference between the two groups: the vascular occlusion time, the dose of radiation, and interventional radiology complication (P>0.05). The median volume infused into the lower and upper balloons is 70 ml (50-100 ml) and 180 ml (100-240 ml). Conclusions: Incrauterine balloon tamponade is as effective as gauze packing in hemostasis following the placenta delivery in PAS. Compared with gauze packing, the uterine balloon tamponade is more effective.

[Ergonomic risk factors of carpal tunnel syndrome in workers of an automobile factory]

Objective: To investigate the occurrence of pain symptoms and risk factors of carpal tunnel syndrome (CTS) in automobile manufacturing workers and provide theoretical basis for the prevention of CTS. Methods: From Nov.5th to Nov.19th, 2017, 446 workers in an automobile factory whose work age was above one year participate in questionnaires by cluster sampling. Chi square test and multifactor logistics regression analysis were used to analyze the factors related to the occurrence of CTS pain symptoms in workers. Results: The incidence of CTS pain among workers in this automobile factory was 20.8%. Working in the same position for a long time (OR=2.137, 95% CI:1.183-3.862) and unable to work reasonably because of uncomfortable posture (OR =2.067, 95% CI: 1.075-3.974) were identified as the risk factors of CTS pain symptoms by multifactor logistics regression analysis. Working age (OR=0.537, 95%CI:0.311-0.926) and work break (OR= 0.489, 95% CI: 0.282-0.849) were identified as the benefit factors of CTS pain symptoms. Conclusion: The incidence of CTS pain in automobile manufacturing workers is related to the posture in the process of labor . Effective ergonomic interventions should be carried out to prevent the occurrence of CTS pain in automobile manufacturing workers.

Highly oxygenated and rearranged limonoids from the stem barks of Entandrophragma utile

Seventeen highly oxygenated and rearranged limonoids, including nine previously undescribed phragmalin-type limonoids with 1,8,9- and 8,9,30-orthesters (entanutilins C-K, 1-9), three undescribed limonoids with rare rearranged-6/6/7/5 skeleton (entanutilins L-N, 10-12), and 5 known limonoids, were isolated from the stem barks of Entandrophragma utile from Ghana (Africa). Their structures including absolute configurations were elucidated based on comprehensive spectroscopic analyses, such as HRESIMS, 1D/2D-NMR, CD exciton chirality method, time-dependent density functional theory (TDDFT)/ECD calculations, and single-crystal X-ray diffraction. Bioactivity screenings suggested that some of these compounds effectively reversed resistance in MCF-7/DOX cells at a nontoxic concentration of 30 μM with 6- to 19-fold enhancing effects.

[Prospective cohort study of fetal nuchal translucency in first-trimester and pregnancy outcome]

Objective: To explore the relationship between fetal nuchal translucency (NT) in the first trimester and pregnancy outcome. Methods: A prospective cohort study was conducted in Nanjjing Drum Tower Hospital from December 2015 to December 2018, 4 958 singleton pregnant women were enrolled to screen fetal ultrasound structure and serology in the first trimester, ultrasound in the second trimester and neonatus physical examination 28 days after birth. According to the results of NT, 167 cases of fetus with increased NT (≥3.0 mm) and 4 791 cases of normal NT were divided, moreover, 86 cases with isolate increased NT and 81 cases of increased NT combined with structural abnormality. The prognosis of fetuses with different NT thickness was analyzed, and the pregnancy outcome of fetuses with isolate increased NT or combined with structural abnormality were analyzed. In the first trimester, if the fetal structure was abnormal or the serological screening result was high risk, the chromosomal microarray analysis (CMA) would be performed by chorionic villus sampling to determine the prenatal diagnosis. Results: (1) The pregnancy outcome for fetus of normal NT: there were 4 791 cases with normal NT. Totally, 4 726 cases with normal NT and no structural abnormalities were screened out in the firsttrimester. In this group, 5 cases of aneuploidies were diagnosed based on high risk of maternal serum biomarkers and 83 cases of structural abnormalities were screened out in the subsequent ultrasound scan and the neonatal examination. Another 65 cases with normal NT present complicated with structural anomalies were screened out in the first trimester and 4 cases were diagnosed as aneuploidies. (2) The pregnancy outcome for fetus of isolate increased NT: 66 (76.7%, 66/86) cases of isolated increased NT were performed CMA, 3 cases were diagnosed as trisomy 21 and terminated pregnancy. Another 4 cases were terminated pregnancy privately without cytogenetic diagnosis. No further anomalies were found in 79 cases till 6 to 21 months postnatally. (3) The pregnancy outcome for fetus of increased NT with structural anomalies: increased NT present with structural anomalies were screened out by detailed anomaly scan in the first trimester and 32 of them were confirmed as aneuploidies. In this group, 70 cases terminated pregnancy, 2 cases had spontaneous miscarriages and 9 cases had liveborns (1 newborn was found ventricular septal defect). (4) The pregnancy outcome for fetus of increased NT with or without structural anomalies: the percentage of aneuploidies in fetuses with isolated increased NT (3.5%, 3/86) was significantly lower than those with structural abnormalities (39.5%,32/81). The healthy survival rate in fetuses with isolated increased NT (91.9%,79/86) was significantly higher than those with structural abnormalities (9.9%, 8/81). Conclusions: A detailed first-trimester anomaly scan could improve prenatal screening efficiency of birth defects. Compared to the fetuses with increased NT combined with structural abnormalities, the healthy survival rate of fetuses with isolated increased NT based on detailed first-trimester anomaly scan is higher and the percentage of fetal aneuploidies is lower.

Variability of soil carbon and nitrogen stocks after conversion of natural forest to plantations in Eastern China

Forest plantation, either through afforestation or reforestation, has been suggested to reverse and mitigate the process of deforestation. However, uncertainties remain in the potential of plantation forest (PF) to sequestrate carbon (C) and nitrogen (N) compared to natural forest (NF). Soil C and N stocks require a critical and updated look at what is happening especially in the context of increasing rate of land use change and climate change. The current study was conducted in China’s Eastern forest to estimate soil C and N stocks in six depth layers (0–10, 10–20, 20–40, 40–60, 60–80 and 80–100 cm) and two forest types (NF and PF) at four sites along climate factors gradient. The results showed that the overall mean soil C and N amounts to a depth of 20 cm ranged from 2.6 ± 1.1 Mg ha⁻¹ to 38.6 ± 23.1 Mg ha⁻¹, and soil nitrogen stock ranged from 0.2 ± 0.1 Mg ha⁻¹ to 3.3 ± 1.5 Mg ha⁻¹. Moreover, a loss of C stock was observed at Qingyuan (QY) by −7%, Dinghushan (DH) by −26%, Jianfengling (JF) by −13% while that of N stock was observed at QY (−8%), DH (−19%) and JF (−12%) at both depth layers. These results indicate that NFs have a better capacity to accumulate soil C and N. The soil C and N decreased from the southeast to the northeast and increased from tropical to temperate mixed forests zone in the eastern part of the study area. The C and N stock mainly occurred in the topsoil and decreased significantly with depth. Moreover, soil C and N stocks increased with age of plantation. This study provides an overview of the current spatial distribution and soil stocks of C and N, as well as the effects of environmental factors on soil C and N stocks. It also indicated that, although mean annual temperature and mean annual precipitation are the key factors affecting the variations in soil C and N, their vertical and horizontal distribution differed in various aspects.

The re-sequencing of complete chloroplast genome of Cinnamomum camphora (Lauraceae) from Quanzhou, China

Cinnamomum camphora is a precious species for its significance of timber. It is also the main component of the subtropical evergreen broad-leaved forest. We report a chloroplast genome of C. camphora from Quanzhou, China. The complete chloroplast genome is 152,730 bp in length consisting of a pair of inverted repeat (IR) regions of 19,968 bp, a small single-copy (SSC) region of 18,874 bp, and a large single-copy (LSC) region of 93,706 bp, respectively. The chloroplast genome encoded 116 genes, including 79 protein-coding genes, 36 tRNA genes, and eight rRNA genes. This result will provide useful genomic basis for the phylogenetic research of Lauraceae.

[The analysis of health effects of exposure to occupational hazards on works in gypsum mining enterprise]

Objective: To investigate the health of gypsum miners in Hubei province and analyze the health effects of occupational disease hazards exposure on gypsum miners. Methods: In April 2017, occupational disease hazard factors were tested on the site of a gypsum mine, and 500 workers were selected by random sampling to conduct questionnaires, relevant data such as occupational health examination was collected, and descriptive statistical analysis was performed. Results: The main occupational hazards of gypsum miners were gypsum dust and noise. The time-weighted average concentration of 8 h in the workplace was 4.32 to 9.34 mg/m(3), and the post pass rate was 69.2% (9/13) ; Respiratory dust 0.13-5.15 mg/m(3), post pass rate 75.0% (3/4). Gypsum miners had finger dysfunction and muscle numbness, joint pain (29.2%, 88/301) and chest pain and breathing difficulties (17.6%, 53/301). Followed by tinnitus, auricle pus, running water (4.7%, 14/301), abnormal muscle tension (2.7%, 8/301). The exposure of occupational disease hazards was associated with respiratory, auditory and neurological symptoms of gypsum miners. Conclusion: The long-term exposure of gypsum workers to gypsum dust, noise and other harmful factors may result in obvious symptoms of respiratory system and other health damage.

[Mid-to-long term outcomes and influence factors of postoperative concurrent chronic ankle instability and posterior ankle impingement]

OBJECTIVE

To investigate the mid-to-long-term efficacy of patients with chronic ankle instability combined with posterior impingement syndrome after 3-9 years of follow-up, and to analyze the influencing factors.

METHODS

From February 2010 to December 2015, 46 patients underwent concurrent lateral ankle ligament repair with posterior ankle arthroscopic surgery at the Institute of Sports Medicine, Peking University Third Hospital. The patient was first placed in a prone position and underwent arthroscopic debridement for the posterior impingement. After finishing the posterior arthroscopy, the surgeon and assistants first translated the patient to the affected side, then turned to the healthy side, and changed the position to the supine position. During the turning over, another assistant held the arthroscope and the instrument to ensure that it was sterile and could be used without replacement. The anterior ankle arthroscopy was operated if necessary and the lateral ankle ligament repair was anatomic repaired with anchors. The 42 patients were followed up, including 26 males and 16 females. The average age was (28.9±10.0) years. The patient's clinical symptoms, joint stability, mobility and motor function were compared by questionnaire and physical examination. The preoperative and postoperative visual analogue scale (VAS) scores, American Orthopaedic Foot and Ankle Society (AOFAS) scores, Tegner scores were compared, and the clinical scores and the patient age, gender, height and weight were compared. The correlations between body mass index (BMI), preoperative duration, surgery duration, and cartilage injury were analyzed.

RESULTS

The mean follow-up time was (71.8±22.8) months. The postoperative VAS scores (1.0 vs. 5.0, P<0.001), AOFAS scores (92 vs. 80, P<0.001), and Tegner scores (6.5 vs. 2, P<0.001) were significantly superior to the preoperative levels. The excellent and good rate was 97.6%. The postoperative VAS score (t=2.719, P=0.10), AOFAS score (t=-2.853, P=0.10), Tegner score (t=-3.443, P=0.001) and time to return exercise (t=2.814, P=0.008) were negatively correlated with the patient age, and the postoperative VAS score was negatively correlated with cartilage injury (Z=-2.195, P=0.028).

CONCLUSION

The mid-to-long-term clinical outcomes of the chronic ankle ligament instability combined with the posterior impingement were good. The age of the patients was negatively correlated with the clinical outcome. The combined cartilage injury could aggravate the postoperative pain.

[Retrospective analysis of modified Karlsson surgery for chronic calcaneofibular ligament injury]

Objective: To retrospectively evaluate the therapeutic effect and influencing factors of the modified Karlsson operation (anchor method) in treating chronic rupture of the calcaneofibular ligament (CFL). Methods: From August 2010 to May 2014, the data of 24 patients with calcaneofibular ligament rupture treated in Institute of Sports Medicine, Third Hospital of Peking University were retrospectively analyzed. All cases were repaired with modified Karlsson operation (anchor method). There were 14 males and 10 females, with an average age of (30±9) years, and the average body mass index (BMI) was (25±5) kg/m(2). Visual analogue pain score (VAS), American Foot and Ankle Surgery Association score (AOFAS), Tegner knee motion score, ankle stability and mobility were followed up and analyzed. The paired t test was used to compare the normal distribution data before and after the operation. Results: The average follow-up time was (41±13) months. Compared with pre-operation, VAS score decreased significantly at the last follow-up [0(0,7) vs 5(0,8), Z=4.13,P=0.000], AOFAS score increased significantly (94±10 vs 70±14, t=8.94, P<0.05), Tegner score increased significantly (4.7±1.5 vs 2.8±1.3, t=6.87, P<0.05), all improved significantly. AOFAS score was excellent in 19 cases, good in 4 cases and moderate in 1 case, the excellent and good rate was 95.8%. Among them, 20 cases (83.3%) were satisfied with the recovery effect after the operation. Postoperative sprain occurred in 5 cases (20.8%) and ankle mobility was limited in 3 cases (12.5%). Conclusions: The modified Karlsson operation (anchor method) can restore the stability of the ankle joint by treating the chronic rupture of CFL. It is an effective therapy for lateral ankle instability.

[Reconstruction of neglected Achilles tendon rupture: flexor hallucis longus transfer versus gastrocnemius turn-down flaps]

Objective: To compare the outcome of either flexor hallucis longus transfer or turn-down of proximal Achilles tendon tissue repair in treating chronic Achilles tendon rupture. Methods: The clinical data of 21 patients who underwent repair of Myerson type Ⅲ chronic Achilles tendon rupture at Peking University Sports Medicine Research Institute from May 2012 to March 2015 were retrospectively analyzed. Among them, 11 cases were treated with flexor hallucis longus (FHL) transfer, and 10 cases were treated with gastrocnemius turn-down flaps repair. The American Orthopedic Foot & Ankle Society (AOFOS) hindfoot score and Tegner motor function score before and after surgery were recorded and compared between the two groups. Data comparison between groups was performed with t test. Results: The patients in the both group were followed up for an average of (21±7) months. The postoperative AOFOS hindfoot score in the long flexor and gastrocnemius groups were both significantly higher than those before surgery, and the differences were statistically significant (97.7±2.6 vs 72.0±8.1 and 96.0±5.5 vs 78.5±6.4, t=10.70, 6.42, both P<0.05).The postoperative Tegner scores of the two groups were also significantly higher than those before surgery (4.2±1.4 vs 0.7±0.4 and 4.1±0.8 vs 0.6±0.5,t=7.29, 9.35, both P<0.05). There were no significant differences in postoperative AOFOS hindfoot scores and Tegner motor function scores between the two groups (both P>0.05). Conclusion: The flexor hallucis longus transfer and turn-down of proximal Achilles tendon tissue repair can both get satisfactory results in treating chronic Achilles tendon rupture.

[Risk factors and sonographic findings associated with the type of placenta accreta spectrum disorders]

Objective: To evaluate the risk factors and sonographic findings of pregnancies complicated by placenta increta or placenta percreta. Methods: Totally, 2 219 cases were retrospectively analyzed from 20 tertiary hospitals in China from January 2011 to December 2015. The data were collected based on the original case records. All cases were divided into two groups, the placenta increta (PI) group (79.1%, 1 755/2 219) and the placenta percreta (PP) group (20.9%, 464/2 219) , according to the degree of placental implantation. The risk factors and sonographic findings of placenta increta or percreta were analyzed by uni-factor and logistic regression statistic methods. Results: The risk factors associated with the degree of placental implantation were age, gravida, previous abortion or miscarriage, previous cesarean sections, and placenta previa (all P<0.05), especially, previous cesarean sections (χ(2)=157.961) and placenta previa (χ(2)=91.759). Sonographic findings could be used to predict the degree of placental invasion especially the boundaries between placenta and uterine serosa, the boundary between placenta and myometrium, the disruption of the placental-uterine wall interface and loss of the normal retroplacental hypoechoic zone(all P<0.01). Conclusions: Previous cesarean sections and placenta previa are the main independent risk factors associated with the degree of placenta implantation. Ultrasound could be used to make a prenatal suggestive diagnosis of placenta accreta spectrum disorders.

Differential patterns of nitrogen and δ15N in soil and foliar along two urbanized rivers in a subtropical coastal city of southern China

Urbanization usually pollutes the environment leading to alterations in key biogeochemical cycles. Therefore, understanding its effects on forest nitrogen (N) saturation is becoming increasingly important for addressing N pollution challenges in urban ecosystems. In this study, we compared soil (N availability, net N mineralization, net nitrification, and δ¹⁵N) and foliar (N concentrations and δ¹⁵N) variables in upstream, midstream and downstream forest stands of Bailongjiang River (BJR; more urbanized) and Wulongjiang River (WJR; less urbanized), the two branches of the Minjiang River Estuary. Total soil N, ammonium, nitrate, net N mineralization and nitrification rates, as well as soil δ¹⁵N were significantly higher in BJR compared with WJR forest stands. While no substantial difference in foliar N concentrations was noted between rivers, foliar δ¹⁵N was on average more than 2.5 times higher in BJR than WJR forest stands. Across the study area, foliar δ¹⁵N was positively related to soil δ¹⁵N, which also had positive linear relationships with soil nitrate concentrations, net N mineralization and net nitrification rates. Moreover, all variables except foliar δ¹⁵N and ammonium concentrations showed decreasing patterns in the order: upstream > midstream > downstream along the BJR forest stands. Soil ammonium and foliar values (N concentrations and δ¹⁵N) revealed clear patterns along the WJR, with the former increasing and the latter decreasing from the upstream to downstream forest stands. Our findings indicate an increase in urbanization-induced N inputs from the WJR to BJR and that forest stands along the BJR especially at the upstream have higher N availability and are shifting rapidly towards N saturation state. These results emphasize the need for effective N pollution control in urban environments through sustainable urban planning.

[Diagnosis and treatment of five neonatal cerebral venous sinus thrombosis]

Objective: To summarize the clinical presentations and imaging features of cerebral venous sinus thrombosis (CVST) in 5 newborns. Methods: The clinical data of 5 newborns with CVST admitted to Department of Neonatology of Maternal and Children Hospital of Hubei Province from February 2017 to April 2018 were analyzed retrospectively. The risk factors, clinical presentations, imaging manifestations and treatment of CVST were investigated. Results: Of the 5 full term neonates, 4 were males and 1 female, with 4 aged less than 7 days and 1 more than 7 days; one with the history of maternal gestational diabetes mellitus, one with maternal gestational hypertension. The clinical presentations included seizures (3 cases), fever (3 cases), dehydration (1 cases), lethargy (2 cases), hypoglycemia (2 cases), thrombocytopenia (2 cases). Electroencephalogram (EEG) showed electrical seizures in 3 cases. Magnetic resonance imaging (MRI) and magnetic resonance venography (MRV) showed 4 cases of intracranial hemorrhage, 3 cases of cerebral parenchymal infarction. For the sites of the thrombi, 4 were in the superior sagittal sinus, 3 in straight sinus, 2 in transverse sinus and 1 in sinus confluence. CT showed intracranial hemorrhage in 2 cases and venous sinus dilatation in 2 cases. Doppler ultrasound showed 2 cases of intraventricular hemorrhage and 2 cases of changes of venous sinus blood flow. Three neonates were treated with anticoagulant and thrombolytic therapy, followed by recanalization of the veins and discontinuing of seizures. Conclusions: Seizure is the main clinical presentation of CVST. The main radiologic manifestations are cerebral infarction and hemorrhage. Timely brain MRI and MRV are helpful in the early diagnosis and treatment of CVST.