Sex differences in the management of patients with suspected acute coronary syndrome in China.

Few studies have assessed sex differences in the management of suspected acute coronary syndrome (ACS). We aimed to compare the evaluation, treatment, and outcomes between males and females with suspected ACS in the emergency department. Data were obtained from a prospective registry of acute chest pain involving 21 emergency departments in Shandong Province, China. The primary endpoint was 30-day major adverse cardiac events (MACEs). Overlap propensity score weighting was used to address potential confounding. A total of 8046 patients were analysed (42.8% female). Overlap-weighted analysis showed no significant association of female sex with 30-day MACEs (odds ratio, 0.91; 95% CI 0.75 to 1.11; P = 0.363). Secondary analyses found that women were less likely to be identified as high risk at first presentation (odds ratio, 0.86; 95% CI 0.78 to 0.94; P < 0.001). In the emergency department, women were less likely to undergo antiplatelet therapy (odds ratio, 0.87; 95% CI 0.79 to 0.96; P = 0.004) or coronary angiography (odds ratio, 0.78; 95% CI, 0.69 to 0.88; P < 0.001). Women had a longer length of stay in the emergency department and were less likely to be admitted to a ward at disposition. These sex differences existed only in the non-ST-elevation subgroup and were independent of risk stratification. Women with non-ST-elevation chest pain in China received suboptimal treatment in the emergency department. However, their clinical outcomes were not significantly different from those of men. Further studies are needed to determine the causes and impacts of these sex differences.

Simulating soil salinity dynamics, cotton yield and evapotranspiration under drip irrigation by ensemble machine learning.

Cotton is widely used in textile, decoration, and industry, but it is also threatened by soil salinization. Drip irrigation plays an important role in improving water and fertilization utilization efficiency and ensuring crop production in arid areas. Accurate prediction of soil salinity and crop evapotranspiration under drip irrigation is essential to guide water management practices in arid and saline areas. However, traditional hydrological models such as Hydrus require more variety of input parameters and user expertise, which limits its application in practice, and machine learning (ML) provides a potential alternative. Based on a global dataset collected from 134 pieces of literature, we proposed a method to comprehensively simulate soil salinity, evapotranspiration (ET) and cotton yield. Results showed that it was recommended to predict soil salinity, crop evapotranspiration and cotton yield based on soil data (bulk density), meteorological factors, irrigation data and other data. Among them, meteorological factors include annual average temperature, total precipitation, year. Irrigation data include salinity in irrigation water, soil matric potential and irrigation water volume, while other data include soil depth, distance from dripper, days after sowing (for EC and soil salinity), fertilization rate (for yield and ET). The accuracy of the model has reached a satisfactory level, R2 in 0.78-0.99. The performance of stacking ensemble ML was better than that of a single model, i.e., gradient boosting decision tree (GBDT); random forest (RF); extreme gradient boosting regression (XGBR), with R2 increased by 0.02%-19.31%. In all input combinations, other data have a greater impact on the model accuracy, while the RMSE of the S1 scenario (input without meteorological factors) without meteorological data has little difference, which is -34.22%~19.20% higher than that of full input. Given the wide application of drip irrigation in cotton, we recommend the application of ensemble ML to predict soil salinity and crop evapotranspiration, thus serving as the basis for adjusting the irrigation schedule.

Effects of nitrogen and phosphorus supply levels and ratios on soil microbial diversity-ecosystem multifunctionality relationships in a coastal nontidal wetland.

Human activities have changed the levels and ratios of nitrogen (N) and phosphorus (P) in wetland ecosystems. However, the effects of N and P levels and ratios on wetland soil microbial community and ecosystem multifunctionality remain unclear, especially on the relationships between soil microbial diversity and ecosystem multifunctionality. In this study, the effects of a 7-year experimental nutrient addition on the soil microbial community and ecosystem multifunctionality (12 function variables related to carbon, N, and P cycling) were assessed by combining three N and P supply levels with three N:P supply ratios in a coastal nontidal wetland ecosystem. According to the obtained results, the N and P supply levels significantly affected soil bacterial community composition, as well as ecosystem multifunctionality, while no significant effects of N:P supply ratios were observed. Although N and P supply levels did not significantly affect bacterial and fungal diversity, they both changed the complexity of bacterial and fungal networks. Soil ecosystem multifunctionality was significantly and positively correlated with bacterial diversity rather than fungal diversity. Moreover, the correlation coefficient between bacterial diversity and ecosystem multifunctionality showed an increasing-decreasing trend with increasing N and P supply levels and an increasing trend with increasing N:P supply ratios. However, the correlation coefficient between bacterial diversity and ecosystem multifunctionality was not significantly correlated with bacterial network complexity. The current study provides new insights into the impacts of N and P levels and ratios on soil microbial community and ecosystem multifunctionality in a coastal nontidal wetland. In particular, the present study highlighted that changes in N and P supply levels and ratios lead to changes in the relationship between soil bacterial diversity and ecosystem multifunctionality, which should be considered in related studies to accurately predict the responses of ecosystem multifunctionality to N and P inputs in coastal nontidal wetlands.

The missing link between zeolites and polyoxometalates.

Open framework materials such as zeolites and metalorganic frameworks are garnering tremendous interest because of their intriguing architecture and attractive functionalities. Thus, new types of open framework materials are highly sought after. Here, we present the discovery of completely new inorganic framework materials, where, in contrast to conventional inorganic open frameworks, the scaffold is not based on tetrahedral EO4 (E = main group element) but octahedral MO6 (M = transition metal) building blocks. These structural features place them closer to polyoxometalates than zeolites. The first representatives of this class of materials are [(R)24(NH4)14(PO(OH)2)6]·[M134(PO3(OH,F))96F120] (M = Co, R = C2Py = 1-ethylpyridinium and M = Ni, R = C4C1Py = 1-butyl-3-methylpyridinium) featuring interlinked fullerene-like nanosphere cavities. Having a transition metal building up the framework brings about interesting properties, for example, spin-glass behavior, and, with this particular topology, a hedgehog-like spin orientation.

The combination of creatine kinase-myocardial band isoenzyme and point-of-care cardiac troponin/ contemporary cardiac troponin for the early diagnosis of acute myocardial infarction.

BACKGROUND: The early diagnosis of acute myocardial infarction (AMI) remains challenging, especially for institutions without the high-sensitive cardiac troponin (hs-cTn) assay. Herein, we aim to assess the value of creatine kinase-myocardial band isoenzyme (CK-MB) combined with different cardiac troponin (cTn) assays in AMI diagnosis. METHODS: This multicenter, observational study included 3,706 patients with acute chest pain from September 1, 2015, to September 30, 2017. We classified the participants into three groups according to the cTn assays: the point-of-care cTn (POC-cTn) group, the contemporary cTn (c-cTn) group, and hs-cTn group. The diagnostic value was quantified using sensitivity and the area under the curve (AUC). RESULTS: Compared to the single POC-cTn/c-cTn assays, combining CK-MB and POC-cTn/c-cTn increased the diagnostic sensitivity of AMI (56.1% vs. 63.9%, P<0.001; 82.7% vs. 84.3%, P=0.025). In contrast, combining CK-MB and hs-cTn did not change the sensitivity compared with hs-cTn alone (95.0% vs. 95.0%, P>0.999). In the subgroup analysis, the sensitivity of combining CK-MB and c-cTn increased with time from symptom onset <6 h compared with c-cTn alone (72.8% vs. 75.0%, P=0.046), while the sensitivity did not increase with time from symptom onset >6 h (97.5% vs. 98.3%, P=0.317). The AUC of the combination of CK-MB and POC-cTn significantly increased compared to the single POC-cTn assay (0.776 vs. 0.750, P=0.002). The AUC of the combined CK-MB and c-cTn/hs-cTn assays did not significantly decrease compared with that of the single c-cTn/hs-cTn assays within 6 h. CONCLUSIONS: The combination of CK-MB and POC-cTn or c-cTn may be valuable for the early diagnosis of AMI, especially when hs-cTn is not available.

Biomarker-based risk model to predict cardiovascular events in patients with acute coronary syndromes - Results from BIPass registry.

Background: Risk models integrating new biomarkers to predict cardiovascular events in acute coronary syndromes (ACS) are lacking. Therefore, we evaluated the prognostic value of biomarkers in addition to clinical predictors and developed a biomarker-based risk model for major adverse cardiovascular events (MACE) within 12 months after hospital admission with ACS. Methods: Patients (n = 4407) consecutively enrolled from November, 2017 to October, 2019 in three hospitals of a prospective Chinese registry (BIomarker-based Prognostic Assessment for Patients with Stable Angina and Acute Coronary Syndromes, BIPass) were designated as the risk model development cohort. Validation was performed in 1409 patients enrolled in two independent hospitals. Cox proportional hazards regression analysis was used to generate a risk prediction model and evaluate the incremental prognostic value of each biomarker. Findings: Over 12 months, 196 patients experienced MACE (5.1%/year). Among twelve candidate biomarkers, N-terminal pro-B-type natriuretic peptide (NT-proBNP) measured at baseline showed the most prognostic capability independent of clinical predictors. The developed BIPass risk model included age, hypertension, previous myocardial infarction, stroke, Killip class, heart rate, and NT-proBNP. It displayed improved discrimination (C-statistic 0.79, 95% CI 0.73-0.85), calibration (GOF = 9.82, p = 0.28) and clinical decision curve in the validation cohort, outperforming the GRACE and TIMI risk scores. Cumulative rates for MACE demonstrated good separation in the BIPass predicted low, intermediate, and high-risk groups. Interpretation: The BIPass risk model, integrating clinical variables and NT-proBNP, is useful for predicting 12-month MACE in ACS. It effectively identifies a gradient risk of cardiovascular events to aid personalized care. Funding: National Key R&D Program of China (2017YFC0908700, 2020YFC0846600), National S&T Fundamental Resources Investigation Project (2018FY100600, 2018FY100602), Taishan Pandeng Scholar Program of Shandong Province (tspd20181220), Taishan Young Scholar Program of Shandong Province (tsqn20161065, tsqn201812129), Youth Top-Talent Project of National Ten Thousand Talents Plan and Qilu Young Scholar Program.

Analysis of potential factors contributing to refusal of invasive strategy after ST-segment elevation myocardial infarction in China.

BACKGROUND: Reduced application of percutaneous coronary intervention (PCI) is associated with higher mortality rates after ST-segment elevation myocardial infarction (STEMI). We aimed to evaluate potential factors contributing to the refusal of PCI in STEMI patients in China. METHODS: We studied 957 patients diagnosed with STEMI in the emergency departments (EDs) of six public hospitals in China. The differences in baseline characteristics and 30-day outcome were investigated between patients who refused PCI and those who underwent PCI. Multivariable logistic regression was used to evaluate the potential factors associated with refusing PCI. RESULTS: The potential factors contributing to refusing PCI were older than 65 years (odds ratio [OR] 2.66, 95% confidence interval [CI] 1.56-4.52, P < 0.001), low body mass index (BMI) (OR 0.91, 95% CI 0.84-0.98, P = 0.013), not being married (OR 0.29, 95% CI 0.17-0.49, P < 0.001), history of myocardial infarction (MI) (OR 2.59, 95% CI 1.33-5.04, P = 0.005), higher heart rate (HR) (OR 1.02, 95% CI 1.01-1.03, P = 0.002), cardiac shock in the ED (OR 5.03, 95% CI 1.48-17.08, P = 0.010), pre-hospital delay (>12 h) (OR 3.31, 95% CI 1.83-6.02, P < 0.001) and not being hospitalized in a tertiary hospital (OR 0.45, 95% CI 0.27-0.75, P = 0.002). Compared to men, women were older, were less often married, had a lower BMI and were less often hospitalized in tertiary hospitals. CONCLUSIONS: Patients who were older, had lower economic or social status, and had poorer health status were more likely to refuse PCI after STEMI. There was a sex difference in the potential predictors of refusing PCI. Targeted efforts should be made to improve the acceptance of PCI among patients with STEMI in China.

Evaluation and comparison of six GRACE models for the stratification of undifferentiated chest pain in the emergency department.

BACKGROUND: The Global Registry of Acute Coronary Events (GRACE) score is recommended for stratifying chest pain. However, there are six formulas used to calculate the GRACE score for different outcomes of acute coronary syndrome (ACS), including death (Dth) or composite of death and myocardial infarction (MI), while in hospital (IH), within 6 months after discharge (OH6m) or from admission to 6 months later (IH6m). We aimed to perform the first comprehensive evaluation and comparison of six GRACE models to predict 30-day major adverse cardiac events (MACEs) in patients with acute chest pain in the emergency department (ED). METHODS: Patients with acute chest pain were consecutively recruited from August 24, 2015 to September 30, 2017 from the EDs of two public hospitals in China. The 30-day MACEs included death, acute myocardial infarction (AMI), emergency revascularization, cardiac arrest and cardiogenic shock. The correlation, calibration, discrimination, reclassification and diagnostic accuracy at certain cutoff values of six GRACE models were evaluated. Comparisons with the History, ECG, Age, Risk Factors, and Troponin (HEART) and Thrombolysis in Myocardial Infarction (TIMI) scores were conducted. RESULTS: A total of 2886 patients were analyzed, with 590 (20.4%) patients experiencing outcomes. The GRACE (IHDthMI), GRACE (IH6mDthMI), GRACE (IHDth), GRACE (IH6mDth), GRACE (OH6mDth) and GRACE (OH6mDthMI) showed positive linear correlations with the actual MACE rates (r ≥ 0.568, P < 0.001). All these models had good calibration (Hosmer-Lemeshow test, P ≥ 0.073) except GRACE (IHDthMI) (P < 0.001). The corresponding C-statistics were 0.83(0.81,0.84), 0.82(0.81,0.83), 0.75(0.73,0.76), 0.73(0.72,0.75), 0.72(0.70,0.73) and 0.70(0.68,0.71), respectively, first two of which were comparable to HEART (0.82, 0.80-0.83) and superior to TIMI (0.71, 0.69-0.73). With a sensitivity ≥95%, GRACE (IHDthMI) ≤81 and GRACE (IH6mDthMI) ≤79 identified 868(30%) and 821(28%) patients as low risk, respectively, which were significantly better than other GRACEs and HEART ≤3(22%). With a specificity ≥95%, GRACE (IHDthMI) > 186 and GRACE (IH6mDthMI) > 161 could recognize 12% and 11% patients as high risk, which were greater than other GRACEs, HEART ≥8(9%) and TIMI ≥5(8%). CONCLUSIONS: In this Chinese setting, certain strengths of GRACE models beyond HEART and TIMI scores were still noteworthy for stratifying chest pain patients. The validation and reasonable application of appropriate GRACE models in the evaluation of undifferentiated chest pain should be recommended.

Comparison of usual care and the HEART score for effectively and safely discharging patients with low-risk chest pain in the emergency department: would the score always help?

BACKGROUND: Triage decisions for chest pain patients receiving usual care are based on a dynamic and comprehensive strategy performed in the physician's mind. It remains controversial whether simple, structured risk tools can surpass real, complex judgments. HYPOTHESIS: The potentially used History, Electrocardiogram, Age, Risk factors, Troponin (HEART) score would help identify low-risk patients for discharge. METHODS: Patients with acute, non-traumatic chest pain managed according to usual care were consecutively enrolled in a tertiary university hospital in China from August 24, 2015 to September 30, 2017. Major adverse cardiac events (MACE) included death, acute myocardial infarction, revascularization, and significant coronary stenosis (>50%) within 30 days. We compared the efficacy and safety of usual care and the potentially used HEART score in this population. RESULTS: Of 2185 patients analyzed, 926 (42.4%) patients were directly discharged by usual care, whereas HEART≤3 would have identified 524 (24.0%) patients as low-risk (P < .001). The MACE rate in discharged patients was 2.2% (20/926) and would have been 5.2% (27/524) in those with HEART≤3 (P = .002). For discharged patients, the MACE rates in HEART≤3 vs HEART>3 groups were not significantly different (1.5% vs 2.7%, P = .225). Negative predictive value (NPV) was higher with usual care than with the HEART score (P = .003), but sensitivity was similar. For 340 patients with serial troponins, usual care was superior to the potentially used HEART score in regard to efficacy. CONCLUSIONS: At this institution, usual care identified many more patients for discharge than the HEART score would have without apparently different outcomes in discharged patients with lower vs higher HEART scores. The HEART score would not appear to provide helpful risk stratification.

Ionothermal Synthesis, Structures, and Magnetism of Three New Open Framework Iron Halide-Phosphates.

A set of different open framework iron phosphates have been synthesized ionothermally using a task-specific ionic liquid, 1-butyl-4-methylpyridinium hexafluorophosphate, that acts in the synthesis as the reaction medium and mineralizer: (NH4)2Fe2(HPO4)(PO4)Cl2F (1) and K2Fe2(HPO4)(PO4)Cl2F (2) exhibit similar composition and closely related structural features. Both structures consist of {Fe2(HPO4)(PO4)Cl2F}2- macroanions and charge balancing ammonium or potassium cations. Their open framework structure contains layers and chains of corner-linked {Fe(1)O2Cl4} and {Fe(2)F2O4} octahedra, respectively, interconnected by PO4 tetrahedra forming 10-ring channels. KFe(PO3F)F2 (3) is built up by {Fe[(PO3F)4/3F2/2]}{Fe(PO3F)2/3F2/2F2} layers separated by K+ cations. Chains of alternating {FeF2O4} and {FeO2F4} octahedra, which are linear for 1 but undulated for 2, are linked to each other via corner-sharing {PO3F} tetrahedra with the fluorine pointing into the interlayer space. The compounds were characterized by means of single crystal and powder X-ray diffraction, infrared spectroscopy, and magnetic measurements. 1 reveals a strong ground state spin anisotropy with a spin 5/2 state and a magnetic moment of 5.3 µB/Fe3+. Specific heat and magnetic data unveil three magnetic transitions at 95, 50, and 3.6 K. Compound 2 has a very similar crystal structure as compared to 1 but exhibits a different magnetic behavior: a slightly lower magnetic moment of 4.7 µB/Fe3+ and a magnetic transition to a canted antiferromagnetic state below 90 K. Compound 3 exhibits typical paramagnetic behavior close to room-temperature (5.71 µB/Fe3+). There are no clear indications for a phase transition down to 2 K despite strong antiferromagnetic spin-spin interactions; only a magnetic anomaly appears at 50 K in the zero-field cooled data.

Overall supply level, not the relative supply of nitrogen and phosphorus, affects the plant community composition of a supratidal wetland in the Yellow River Delta.

Human activities have altered the environmental nitrogen (N) and phosphorus (P) supply from both aspects of overall supply level and relative supply ratio. However, the effects of the two aspects on plant community composition are still not clear. In this study, a field manipulation experiment combining 3 overall nutrient supply levels (Low, Medium and High) and 3 N:P supply ratios (5,1, 15:1 and 45:1) was conducted in a supratidal wetland in the Yellow River Delta from 2015 to 2018. The effects of the two aspects on soil properties, performance of dominant species and plant community diversity were examined. The results showed that the N:P supply ratio and overall supply level both affected the concentration of soil inorganic N and available P, and N:P ratio significantly, while only overall supply level exerted a significant effect on the importance value of the dominant species, species richness and Shannon diversity. There were big gaps in the N and P supply amounts among the treatments that having same overall supply level with different supply ratio, but the plant composition displayed no significant difference among these treatments, which suggested that P may be also very important in affecting plant community composition in the study area. The species richness and the Shannon diversity were negatively correlated with the importance value of Suaeda glauca. With the rise of overall supply level, S. glauca became increasingly dominant and suppressed other species. Compared with the control treatment, the species richness and the Shannon diversity declined significantly only at high supply level (minimum N supply amount of 26.01 g m-2 yr-1), indicated that the supratidal wetland had high resilience to nutrient enrichment. Our results revealed that the N:P supply ratio has little influence on plant composition, compared with overall supply, in relative short-term in the supratidal wetland.

Clinical impact of using a more sensitive troponin assay in patients with acute chest pain.

BACKGROUND: More sensitive troponin assays have the potential to better evaluate patients with suspected acute coronary syndrome (ACS). Meanwhile, they may result in avoidable diagnostic testing. HYPOTHESIS: Our aim was to determine the clinical impact of implementing a more sensitive cardiac troponin I (cTnI) assay in patients with acute non-traumatic chest pain presenting to the emergency department (ED). METHODS: This is a pre-post cohort study. A total of 1201 consecutive patients with acute non-traumatic chest pain or equivalent ischemic symptoms suggestive of ACS were allocated to two groups according to the cTnI assay used. The outcomes included the ED length of stay (LOS), hospital admission rate, the use of procedures and the incidence of major adverse cardiac events (MACE) at 30 days. RESULTS: The introduction of the more sensitive troponin assay shortened ED LOS (odds ratio [OR] 0.39, 95% confidence interval [CI] 0.28-0.54) regarding patients discharged home directly, increased the hospital admission rate (OR 1.43, 95% CI 1.12-1.84), the use of echocardiography (OR 1.58, 95% CI 1.22-2.06), coronary computed tomography angiography (OR 1.78, 95% CI 1.04-3.06), coronary angiography (OR 1.53, 95% CI 1.10-2.12) and percutaneous coronary intervention (OR 2.42, 95% CI 1.58-3.70) regarding patients discharged or admitted. The incidence of MACE did not decrease significantly (OR 0.61, 95% CI 0.27-1.37). CONCLUSIONS: The introduction of the more sensitive troponin assay appeared to result in less time spent in the ED regarding patients discharged home directly, but prompted more hospitalizations and procedures without impacting the incidence of MACE.

Effective combination of isolated symptom variables to help stratifying acute undifferentiated chest pain in the emergency department.

BACKGROUND: Symptom is still indispensable for the stratification of chest pain in the emergency department. However, it is a sophisticated aggregation of several aspects of characteristics and effective combination of those variables remains deficient. We aimed to develop and validate a chest pain symptom score (CPSS) to address this issue. HYPOTHESIS: The CPSS may help stratifying acute undifferentiated chest pain in ED. METHODS: Patients with non-ST segment elevation chest pain and negative cardiac troponin (cTn) over 3 hours after symptom onset were consecutively recruited as the derivation cohort. Logistic regression analyses identified statistical predictors from all symptom aspects for 30-day acute myocardial infarction (AMI) or death. The performance of CPSS was compared with the symptom classification methods of the history variable in the history, electrocardiograph, age, risk factors, troponin (HEART) score. This new model was validated in a separated cohort of patients with negative cTn within 3 hours. RESULTS: Seven predictors in four aspects of chest pain symptom were identified. The CPSS was an independent predictor for 30-day AMI or death (P < 0.001). In the derivation (n = 1434) and validation (n = 976) cohorts, the expected and observed event rates were well calibrated (Hosmer-Lemeshow test P > 0.30), and the c-statistics of CPSS were 0.72 and 0.73, separately, significantly better than the previous history classifications in HEART score (P < 0.001). Replacing the history variable with the CPSS improved the discrimination and risk classification of HEART score significantly (P < 0.001). CONCLUSIONS: The effective combination of isolated variables was meaningful to make the most stratification value of symptoms. This model should be considered as part of a comprehensive strategy for chest pain triage.

Evaluation and management of patients with acute chest pain in China (EMPACT): protocol for a prospective, multicentre registry study.

INTRODUCTION: Acute chest pain represents a major healthcare burden in emergency departments (ED) throughout the world. Among these patients, rapidly determining whether an acute coronary syndrome (ACS) is evolving remains difficult. In China, there are limited data correlating the baseline characteristics, evaluation and management of ED patients with acute chest pain and ACS-related symptoms with clinical outcomes. Nor has there been an evaluation of outcomes at different levels of hospitals. The Evaluation and Management of Patients with Acute ChesT pain in China (EMPACT) study will address this evidence gap through a regional representative prospective registry. METHODS AND ANALYSIS: Twenty-two public hospitals with ED in Shandong province have been selected based on a stratified random sampling approach. A total of 10 000 patients with acute chest pain or suspected ACS presenting to the ED will be consecutively enrolled from January 2016 to September 2017. Episodes of care will be evaluated for key performance measures such as the time to first ECG, receipt of troponin testing, receipt of reperfusion therapy for ST segment elevation ACS and provision of angiography for troponin-positive patients. All patients will be assessed for the composite endpoint of adjudicated major adverse cardiac events in 30 days after presentation, including death from all causes, non-fatal myocardial infarction, urgent revascularisation, stroke, cardiac arrest and cardiogenic shock. The secondary outcomes include revisit to ED and rehospitalisation within 30 days. ETHICS AND DISSEMINATION: Ethics approval was obtained at all participating centres. The registry is the first attempt to comprehensively evaluate the current emergency care of acute chest pain from a regional representative sample in China. Findings will allow new opportunities to facilitate the clinical quality improvements and ultimately reduce the mortality in patients with acute chest pain and suspected ACS. TRIAL REGISTRATION NUMBER: NCT02536677; Pre-results.

Usage of ambulance transport and influencing factors in acute coronary syndrome: a cross-sectional study at a tertiary centre in China.

OBJECTIVES: The aim of this study was to explore the choice of transportation mode to hospital in patients with acute coronary syndrome (ACS) and to determine the factors influencing the use of ambulance. DESIGN, SETTING AND PARTICIPANTS: This cross-sectional study was conducted in a tertiary and teaching hospital in China. The study was carried out between 24 August 2015 and 24 July 2016. A total of 828 patients with ACS presented at the emergency department (ED) were included. The study population was dichotomised according to their primary mode of transport (ambulance or self-transport) to hospital. Social demographics, cardiovascular history, risk factors, prehospital medications, clinical characteristics and symptom characteristics were collected. Multivariable logistic regression was used to examine the factors associated with ambulance use. RESULTS: We found that only 179 (21.6%) patients with ACS chose taking ambulance to hospital. Factors associated with ambulance use were single (OR 1.66, 95% CI 1.07 to 2.57), taking Suxiaojiuxin pills (OR 1.91, 1.31 to 2.80) or nitrates (OR 2.91, 1.70 to 4.99) before going to hospital, diagnosed as ST-elevation myocardial infarction (STEMI) (OR 2.43, 1.45 to 4.05), with persistent symptoms (OR 1.95, 1.33 to 2.86) and symptoms accompanied with vomiting (OR 2.35, 1.19 to 4.62). The patients who had symptoms precipitated or aggravated by exercise (OR 0.37, 0.14 to 0.98) tended to choose self-transport. CONCLUSION: The usage of ambulance in patients with ACS presenting to the ED was low in China. Factors like single, taking Suxiaojiuxin pills or nitrates before going to hospital, diagnosed as STEMI, accompanied with vomiting and persistent symptoms were independently associated with ambulance use. Future education programmes should focus on these factors and increase people's knowledge on ACS and the benefits of ambulance use.

Distribution of carbon, nitrogen and phosphorus in coastal wetland soil related land use in the Modern Yellow River Delta.

The delivery and distribution of nutrients in coastal wetland ecosystems is much related to the land use. The spatial variations of TOC, TN, NH4+-N, NO3--N and TP and associated soil salinity with depth in 9 kinds land uses in coastal zone of the modern Yellow River Delta (YRD) was evaluated based on monitoring data in field from 2009 to 2015. The results showed that the average contents of soil TOC, TN, NO3--N, NH4+-N and TP were 4.21 ± 2.40 g kg-1, 375.91 ± 213.44, 5.36 ± 9.59 and 7.20 ± 5.58 and 591.27 ± 91.16 mg kg-1, respectively. The high N and C contents were found in cropland in southern part and low values in natural wetland, while TP was relatively stable both in profiles and in different land uses. The land use, land formation age and salinity were important factors influencing distributions of TOC and N. Higher contents of TOC and N were observed in older formation age lands in whole study region, while the opposite regulation were found in new-born natural wetland, indicating that the anthropogenic activities could greatly alter the original distribution regulations of nutrients in coastal natural wetlands by changing the regional land use.

Bacterial community structure and function shift along a successional series of tidal flats in the Yellow River Delta.

Coastal ecosystems play significant ecological and economic roles but are threatened and facing decline. Microbes drive various biogeochemical processes in coastal ecosystems. Tidal flats are critical components of coastal ecosystems; however, the structure and function of microbial communities in tidal flats are poorly understood. Here we investigated the seasonal variations of bacterial communities along a tidal flat series (subtidal, intertidal and supratidal flats) and the factors affecting the variations. Bacterial community composition and diversity were analyzed over four seasons by 16S rRNA genes using the Ion Torrent PGM platform. Bacterial community composition differed significantly along the tidal flat series. Bacterial phylogenetic diversity increased while phylogenetic turnover decreased from subtidal to supratidal flats. Moreover, the bacterial community structure differed seasonally. Canonical correspondence analysis identified salinity as a major environmental factor structuring the microbial community in the sediment along the successional series. Meanwhile, temperature and nitrite concentration were major drivers of seasonal microbial changes. Despite major compositional shifts, nitrogen, methane and energy metabolisms predicted by PICRUSt were inhibited in the winter. Taken together, this study indicates that bacterial community structure changed along the successional tidal flat series and provides new insights on the characteristics of bacterial communities in coastal ecosystems.

Seasonal Variations of C: N: P Stoichiometry and Their Trade-Offs in Different Organs of Suaeda salsa in Coastal Wetland of Yellow River Delta, China.

Variations of plant C: N: P stoichiometry could be affected by both some environmental fluctuations and plant physiological processes. However, the trade-off mechanism between them and their influencial factors were not understood completely. In this study, C, N, P contents and their stoichiometry of S. salsa's plant organs (leaves, stems, and roots), together with their environmental factors including salinity, pH, soil N and soil P, were examined in the intertidal and supratidal habitats of coastal wetlands during the different sampling times (May, July, September, November). The results showed that both plant organ and sampling times affected C, N, and P and stoichiometry of S. salsa in the intertidal and supratidal habitats, however, their influencial conditions and mechanisms were different. In the intertidal habitat, the different slopes of C-P and N-P within interspecific organs suggested that plant P, C:P and N:P of S. salsa were modulated by P concentrations that allocated in the specific organs. However, the slopes of C-N were found to be not significant within interspecific organs, but during the sampling times. These differences of plant N and C:N were related with the physiological demand for N in the specific life history stage. In the supratidal habitat, no significant differences were found in the slopes of C-N, C-P, and N-P within interspecific organs. However, different slopes of C-N among the sampling times also indicated a self-regulation strategy for plant N and C:N of S. salsa in different ontogenetic stages. In contrast to the intertidal habitat, seasonal variations of P, C:P and N:P ratios within interspecific organs reflected the soil P characteristics in the supratidal habitat. Our results showed that the stoichiometric constraint strategy of plant S. salsa in this region was strongly correlated with the local soil nutrient conditions.

Changes of soil particle size distribution in tidal flats in the Yellow River Delta.

BACKGROUND: The tidal flat is one of the important components of coastal wetland systems in the Yellow River Delta (YRD). It can stabilize shorelines and protect coastal biodiversity. The erosion risk in tidal flats in coastal wetlands was seldom been studied. Characterizing changes of soil particle size distribution (PSD) is an important way to quantity soil erosion in tidal flats. METHOD/PRINCIPAL FINDINGS: Based on the fractal scale theory and network analysis, we determined the fractal characterizations (singular fractal dimension and multifractal dimension) soil PSD in a successional series of tidal flats in a coastal wetland in the YRD in eastern China. The results showed that the major soil texture was from silt loam to sandy loam. The values of fractal dimensions, ranging from 2.35 to 2.55, decreased from the low tidal flat to the high tidal flat. We also found that the percent of particles with size ranging between 0.4 and 126 µm was related with fractal dimensions. Tide played a great effort on soil PSD than vegetation by increasing soil organic matter (SOM) content and salinity in the coastal wetland in the YRD. CONCLUSIONS/SIGNIFICANCE: Tidal flats in coastal wetlands in the YRD, especially low tidal flats, are facing the risk of soil erosion. This study will be essential to provide a firm basis for the coast erosion control and assessment, as well as wetland ecosystem restoration.