Political incentives in market-based environmental regulation: Evidence from China's carbon emissions trading scheme.

This paper used a multi-period DID model with panel data from 283 Chinese cities between 2006 and 2019 to investigate the emission reduction effects and mechanisms of China's carbon trading scheme. The research revealed that China's Carbon Emissions Trading Scheme not only stimulated businesses to reduce emissions as a market-based environmental regulation policy but also influenced local governments' governance objectives. As a result, the Hawthorne effect inevitably manifested during the experimental period of China's Carbon Emissions Trading Scheme. Further analysis indicated that China's CETS encouraged local authorities to take a more proactive stance towards the balance between environmental preservation and economic growth, aiming to achieve a mutually beneficial outcome. Based on the political stance of local governments, they are likely to simultaneously increase their focus on both economic growth and environmental protection. However, when faced with the conflict between economic advancement and environmental safeguarding, pilot regions prioritized ecological conservation in their practical steps, leading to a modest decline in economic growth. In other words, the government's high-profile announcements may not always manifest in actual deeds. In practice, local authorities tend to allocate more administrative resources to areas highly prioritized by the central government. Furthermore, the extended analysis reveals that China's CETS has resulted in a reduction in social welfare due to a shift in governance priorities influenced by political incentives. Therefore, fine-tuning the performance evaluation mechanism, preventing any bias towards the target preferences of local authorities, and guaranteeing the successful operation of the market mechanism are imperative to achieve truly low-cost and sustainable emissions reductions objectives for CETS.

A GPU-based fast Monte Carlo code that supports proton transport in magnetic field for radiation therapy.

This paper presents the effort to extend a previously reported code ARCHER, a GPU-based Monte Carlo (MC) code for coupled photon and electron transport, into protons including the consideration of magnetic fields. The proton transport is modeled using a Class-II condensed-history algorithm with continuous slowing-down approximation. The model includes ionization, multiple scattering, energy straggling, elastic and inelastic nuclear interactions, as well as deflection due to the Lorentz force in magnetic fields. An additional direction change is added for protons at the end of each step in the presence of the magnetic field. Secondary charge particles, except for protons, are terminated depositing kinetic energies locally, whereas secondary neutral particles are ignored. Each proton is transported step by step until its energy drops to below 0.5 MeV or when the proton leaves the phantom. The code is implemented using the compute unified device architecture (CUDA) platform for optimized GPU thread-level parallelism and efficiency. The code is validated by comparing it against TOPAS. Comparisons of dose distributions between our code and TOPAS for several exposure scenarios, ranging from single square beams in water to patient plan with magnetic fields, show good agreement. The 3D-gamma pass rate with a 2 mm/2% criterion in the region with dose greater than 10% of the maximum dose is computed to be over 99% for all tested cases. Using a single NVIDIA TITAN V GPU card, the computational time of ARCHER is found to range from 0.82 to 4.54 seconds for 1 × 107 proton histories. Compared to a few hours running on TOPAS, this speed improvement is significant. This work presents, for the first time, the performance of a GPU-based MC code to simulate proton transportation magnetic fields, demonstrating the feasibility of accurate and efficient dose calculations in potential magnetic resonance imaging (MRI)-guided proton therapy.

Carbon ecological security assessment based on the decoupling relationship between carbon balance pressure and ecological quality in Xuzhou City, China.

Building a carbon ecological security (CES) framework helps to scientifically evaluate and manage the regional carbon cycle and eco-environment and support regional ecological security patterns. This paper adopted the pressure-state-response-immune (PSRI) model and the carbon balance index method to evaluate the ecological quality and carbon balance pressure. Then, based on the decoupling model and the improved four-quadrant model, the CES framework was constructed to evaluate the changing trend of the CES of Xuzhou City from 2005 to 2020. The results showed that the carbon balance pressure of Xuzhou City showed a pattern of "low-high-low" from east to west, and most areas tended to have a carbon balance and surplus in 2020. The ecological quality showed an overall upward trend during the study period. Protection and restoration drove the response and immune index growth from 2010 to 2020. In the Thirteenth Five-Year Plan stage, the nine districts of Xuzhou City were in a stable decoupling state, and the overall decoupling process was ideal. The CES of districts showed individual differences in the general upward trend. The carbon balance pressure of Gulou and Quanshan Districts was the main factor restricting the districts' CES. Therefore, based on the empirical results, this research proposes relevant suggestions to enhance carbon ecological security to achieve regional green and low-carbon development.

[Improvement and application on the estimation model of windbreak and sand fixation function based on remote sensing soil moisture factor]. / åŸºäºŽé¥æ„ŸåœŸå£¤æ¹¿åº¦å› å­çš„é˜²é£Žå›ºæ²™åŠŸèƒ½ä¼°ç®—æ¨¡åž‹æ”¹è¿›åŠåº”ç”¨.

Soil moisture factor is one of the important parameters in the study of wind and sand fixation functions of ecosystems. Traditional methods often use potential evaporation, rainfall, and irrigation observed by meteorological stations to estimate soil moisture, which has significant limitations in terms of spatial continuity and data availability. Based on the development of remote sensing technology in soil moisture detection, we selected four remote sen-sing indicators for soil moisture (MODIS evapotranspiration ratio method, SMAP soil moisture ratio method, visible shortwave infrared drought index method, and remote sensing humidity index method) to improve the estimation of soil moisture factor in the modified wind erosion equation model (RWEQ), and used the improved algorithm to analyze the spatiotemporal variations and driving factors of wind prevention and sand fixation services in the northwest region of Liaoning Province from 2001 to 2021. The results showed that the MODIS evapotranspiration ratio method had the highest correlation with traditional meteorological methods in calculating soil moisture. The formula obtained by fitting the two could be used to improve the calculation of soil moisture factor in the RWEQ model. From 2001 to 2021, the wind prevention and sand fixation capacity in the northwest region of Liaoning Province showed strong spatial distribution characteristics in the northern and eastern regions, while weak in the central and western regions. According to Mann-Kendall trend testing, 72.7% of the regions in northwest Liaoning Province were showing an upward trend in their ability to prevent wind and fix sand. The application of geographic detector models for driving factor analysis showed that the change in wind and sand fixation capacity was a process of multiple factors interacting with each other, greatly influenced by soil type, annual wind speed, and economic development level. Moreover, the interaction between various driving factors had a higher impact on wind and sand fixation than that of single factors. The results could improve the RWEQ model estimation and provide technical support for the long-term analysis of ecological function formation mechanisms and driving forces in the northwest region of Liaoning.

Deep learning image reconstruction algorithms in low-dose radiation abdominal computed tomography: assessment of image quality and lesion diagnostic confidence.

Background: The image quality of computed tomography (CT) can be adversely affected by a low radiation dose, and reconstruction algorithms of an appropriate level may be useful in reducing this impact. Methods: Eight sets of CT images of a phantom were reconstructed with filtered back projection (FBP); adaptive statistical iterative reconstruction-Veo (ASiR-V) at 30% (AV-30), 50% (AV-50), 80% (AV-80), and 100% (AV-100); and deep learning image reconstruction (DLIR) at low (DL-L), medium (DL-M), and high (DL-H) levels. The noise power spectrum (NPS) and task transfer function (TTF) were measured. Thirty consecutive patients underwent low-dose radiation contrast-enhanced abdominal CT scans that were reconstructed using FBP, AV-30, AV-50, AV-80, and AV-100, and three levels of DLIR. The standard deviation (SD), signal-to-noise ratio (SNR), and contrast-to-noise ratio (CNR) of the hepatic parenchyma and paraspinal muscle were evaluated. Two radiologists assessed the subjective image quality and lesion diagnostic confidence using a 5-point Likert scale. Results: In the phantom study, both a higher DLIR and ASiR-V strength and a higher radiation dose led less noise. The NPS peak and average spatial frequency of the DLIR algorithms were closer to those of FBP, as the tube current increased and declined as the level of ASiR-V and DLIR strengthened. The NPS average spatial frequency of DL-L were higher than those of AISR-V. In clinical studies, AV-30 demonstrated a higher SD and lower SNR and CNR compared to DL-M and DL-H (P<0.05). For qualitative assessment, DL-M produced the highest qualitative image quality scores, with the exception of overall image noise (P<0.05). The NPS peak, average spatial frequency, and SD were the highest and the SNR, CNR, and subjective scores were the lowest with FBP. Conclusions: Compared with FBP and ASiR-V, DLIR provided better image quality and noise texture both in the phantom and clinical studies, and DL-M maintained the best image quality and lesion diagnostic confidence in low-dose radiation abdominal CT.

Carbon and water footprint analysis of pig farm buildings in Northeast China using building-information-modeling enabled assessment.

Environmental impact evaluation of buildings is critical for further analysis and optimization of pig farms for sustainable pork production. This study is the first attempt to quantify the carbon and water footprints of a standard intensive pig farm building using building information modeling (BIM) and operation simulation model. The model was constructed with carbon emission and water consumption coefficients, and a database was built. The results showed that the operational stage of pig farm accounted for most of the carbon footprint (49.3-84.9 %) and water footprint (65.5-92.5 %). Building materials production ranked second in carbon (12.0-42.5 %) and water footprints (4.4-24.9 %), and pig farm maintenance ranked third in carbon (1.7-5.7 %) and water footprints (0.7-3.6 %). Notably, the mining and production stages of building materials contributed the largest carbon and water footprints of pig farm construction. Masonry materials have a significant impact on the overall carbon and water footprints of the pig farm. Pig farm using aerated concrete could reduce 41.1 % of the total carbon footprint and 58.9 % of the total water footprint compared to that using coal gangue sintered brick and autoclaved fly ash brick. This study presented a BIM-enabled method for carbon and water footprint analysis of pig farms and illustrated how the model can be used to facilitate the low carbon design of agricultural buildings.

MRI Assessment of Renal Lipid Deposition and Abnormal Oxygen Metabolism of Type 2 diabetes Mellitus Based on mDixon-Quant.

BACKGROUND: Diabetic nephropathy (DN) is the main cause of end-stage renal failure. Multiecho Dixon-based imaging utilizes chemical shift for water-fat separation that may be valuable in detecting changes both fat and oxygen content of the kidney from a single dataset. PURPOSE: To investigate whether multiecho Dixon-based imaging can assess fat and oxygen metabolism of the kidney in a single breath-hold acquisition for patients with type 2 diabetes mellitus (DM). STUDY TYPE: Prospective. SUBJECTS: A total of 40 DM patients with laboratory examination of biochemical parameters and 20 age- and body mass index (BMI)-matched healthy volunteers (controls). FIELD STRENGTH/SEQUENCE: 3D multiecho Dixon gradient-echo sequence at 3.0 T. ASSESSMENT: The DM patients were divided into two groups based on urine albumin-to-creatinine ratio (ACR): type 2 diabetes mellitus (DM, 20 patients, ACR < 30 mg/g) and diabetic nephropathy (DN, 20 patients, ACR ≥ 30 mg/g). In all subjects, fat fraction (FF) and relaxation rate (R2*) maps were derived from the Dixon-based imaging dataset, and mean values in manually drawn regions of interest in the cortex and medulla compared among groups. Associations between MRI and biochemical parameters, including ß2-microglobulin, were investigated. STATISTICAL TESTS: Kruskal-Wallis tests, Spearman correlation analysis, and receiver operating characteristic (ROC) curve analysis. RESULTS: FF and R2* values of the renal cortex and medulla were significantly different among the three groups with control group < DM < DN (FF: control, 1.11± 0.30, 1.10 ± 0.39; DM, 1.52 ± 0.32, 1.57 ± 0.35; DN, 1.99 ± 0.66, 2.21 ± 0.59. R2*: Control, 16.88 ± 0.77, 20.70 ± 0.86; DM, 17.94 ± 0.75, 22.10 ± 1.12; DN, 19.20 ± 1.24, 23.63 ± 1.33). The highest correlation between MRI and biochemical parameters was that between cortex R2* and ß2-microglobulin (r = 0.674). A medulla R2* cutoff of 21.41 seconds-1 resulted in a sensitivity of 80%, a specificity of 85% and achieved the largest area under the ROC curve (AUC) of 0.83 for discriminating DM from the controls. A cortex FF of 1.81% resulted in a sensitivity of 80%, a specificity of 100% and achieved the largest AUC of 0.83 for discriminating DM from DN. DATA CONCLUSION: Multiecho Dixon-based imaging is feasible for noninvasively distinguishing DN, DM and healthy controls by measuring FF and R2* values. EVIDENCE LEVEL: 2. TECHNICAL EFFICACY: Stage 2.

MRI Assessment of the Relationship Between Cortical Morphological Features and Hemiparetic Motor-Related Outcomes in Chronic Subcortical Stroke Patients.

BACKGROUND: It is unclear which cortical regions are specific to or commonly associated with the impairments of the upper/lower limbs and the activities of daily life (ADL) in stroke patients. PURPOSE: To investigate the relationships between MRI-assessed surface-based morphometry (SBM) features and motor function as well as ADL in participants with chronic stroke. STUDY TYPE: Prospective. SUBJECTS: Thirty-five participants with subcortical stroke more than 3 months from the first-onset (age: 56.44 ± 9.56 years; 32 male). FIELD STRENGTH/SEQUENCE: T1 -weighted images, 3.0 T, three-dimensional fast field-echo sequence. ASSESSMENT: FreeSurfer (6.0) was used to parcellate each hemisphere into 34 regions based on the Desikan-Killiany atlas and to extract the surface area, volume, thickness, and curvature. The motor function and ADL were assessed by the Fugl-Meyer Assessment for the Upper/Lower Extremity (FMA-UE/FMA-LE) and the Chinese version of the Modified Barthel Index (MBI-C), respectively. STATISTICAL TESTS: A linear mixed-effect model was applied to evaluate the relationship between the morphological features and the FMA-UE, FMA-LE, and MBI-C. A false discovery rate corrected P value < 0.05 was considered statistically significant. RESULTS: Correlations between the size of stroke lesion and MRI measurements did not pass the FDR correction (adjusted P > 0.05). SBM features in motor-related and high-order cognitive cortical regions showed significant correlations with FMA-UE and FMA-LE, respectively. Moreover, the thickness in the prefrontal cortex significantly positively correlated, while the surface area in the right supramarginal gyrus significantly negatively correlated, with both FMA-UE, FMA-LE, and MBI-C. The thickness in the left frontal lobe significantly positively correlated with both FMA-UE and MBI-C. DATA CONCLUSION: This study's findings suggest that different hemiparetic motor-related outcomes in participants with subcortical stroke which suffered a corticospinal tract-related injury show specific, but also share common, associations with several cortical regions. EVIDENCE LEVEL: 2 TECHNICAL EFFICACY: Stage 2.

Burden of Malaria in Sao Tome and Principe, 1990-2019: Findings from the Global Burden of Disease Study 2019.

Background: Malaria is a parasitic infection transmitted by mosquito vectors, commonly found in tropical regions, and characterized by high morbidity and mortality. It causes a heavy disease burden in Sao Tome and Principe (STP), an island country in West Africa which at one time had a high incidence of malaria. Objective: This study aims to analyze the trend of disease burden of malaria in STP. Methods: The crude and age-standardized incidence, mortality, and disability-adjusted life years (DALYs) rate data of malaria were extracted from GBD 2019. Joinpoint 4.9 software was used to calculate the annual percentage change (APC) and the average annual percentage change (AAPC), which were also used to indicate the change in disease burden by different stages. Results: In general, the age-standardized incidence rate (ASIR), age-standardized mortality rate (ASMR), and age-standardized DALYs rate (ASDR) of malaria presented a decreasing trend between 1990 and 2019, with an average annual decrease of 5.6%, 6.2%, and 10.7%, respectively, in STP. Specifically, all indicators first presented an increasing trend from 1990 to about 2000, followed by a decreasing trend until 2019, although the incidence rebounded slightly after 2015. Overall, the ASIR, ASMR, and ASDR of malaria reduced by 77.08%, 87.84%, and 82.21%, respectively, in 2019 as compared to 1990. No significant differences in disease burden were found between males and females between 2005 and 2019. Children who were under 5 years old showed a relatively small decrease in the rate of DALYs as compared to other age groups, but remained the group with the highest disease burden of malaria in the country. Conclusions: The disease burden of malaria in STP showed a significant decrease between 1990 and 2019, but it will still be challenging to achieve the goal of eliminating malaria by 2025. The government and relevant authorities should aim to strengthen the prevention and surveillance of malaria and tailor population-specific interventions in order to reduce the disease burden of malaria in STP.

Clinical Study on Blood Pressure Variability, Montreal Cognitive Assessment and Arteriosclerosis Index in Patients with Cerebral Small Vessel Disease Treated with Integrated Traditional Chinese and Western Medicine by Invigorating Kidney and Removing Blood Stasis.

Objective: To explore the clinical improvement in blood pressure variability, Montreal Cognitive Assessment, and angiosclerosis index in patients with cerebral small vessel disease treated with integrated traditional Chinese and Western medicine. Methods: A randomized controlled study of patients with cerebral small vessel disease who were treated in our hospital from November 1, 2018, to January 31, 2022. The enrolled patients were randomized into 2 groups according to the random numbers: an observation group treated with integrated traditional Chinese and Western medicine and a control group treated with Western medicine only. Blood pressure variability, Montreal Cognitive Assessment (MoCA), and angiosclerosis index were compared between the two groups. Results: There were 71 qualified cases in the observation group and 58 qualified cases in the control group. Before treatment, the indicators between the two groups were comparable (P > 0.05). After treatment, the mean values of systolic blood pressure (SBP) and diastolic blood pressure (DBP) were significantly decreased (P < 0.05); the decrease of 24hSBP-coefficient of variation (CV), daytime SBP (dSBP)-CV, 24hSBP-standard deviation (SD), and dSBP-SD in the observation group was significantly better than that in the control group; the MoCA scores of the observation group were significantly higher than those of the control group ((P < 0.05); the ABI and PWV were significantly different between the two groups (P < 0.05); TC, TG, HDL-C, and LDL-C in observation group decreased after treatment, and HDL-C increased significantly (P < 0.05). Conclusion: Integrative traditional Chinese and Western medicine treatment can further reduce the blood pressure variability, especially systolic blood pressure; improve the MoCA score and cognitive function, increase the ankle-brachial index, reduce pulse wave velocity and the degree of arteriosclerosis; and improve lipid metabolism a comprehensive intervention role.

Multistate Markov model application for blood pressure transition among the Chinese elderly population: a quantitative longitudinal study.

OBJECTIVE: To explore the transitions of different blood pressure states based on a multistate Markov model among the Chinese elderly population. SETTING: A community health centre in Xiamen, China. PARTICIPANTS: 1833 elderly Chinese people. METHODS: A multistate Markov model was built based on 5001 blood pressure measurements from 2015 to 2020. Research was conducted to explore the process of hypertension progression, providing information on the transition probability, HR and the mean sojourn time in three blood pressure states, namely normal state, elevated state and hypertensive state. RESULTS: Probabilities of moving from the normal state to the hypertensive state in the first year were 16.97% (female) and 21.73% (male); they increased dramatically to 47.31% (female) and 51.70% (male) within a 3-year follow-up period. The sojourn time in the normal state was 1.5±0.08 years. Elderly women in the normal state had a 16.97%, 33.30% and 47.31% chance of progressing to hypertension within 1, 2 and 3 years, respectively. The corresponding probabilities for elderly men were 21.73%, 38.56% and 51.70%, respectively. For elderly women starting in the elevated state, the probabilities of developing hypertension were 25.07%, 43.03% and 56.32% in the next 1, 2 and 3 years, respectively; while the corresponding changes for elderly men were 20.96%, 37.65% and 50.86%. Increasing age, body mass index (BMI) and glucose were associated with the probability of developing hypertension from the normal state or elevated state. CONCLUSIONS: Preventive actions against progression to hypertension should be conducted at an early stage. More awareness should be paid to elderly women with elevated state and elderly men with normal state. Increasing age, BMI and glucose were critical risk factors for developing hypertension. The derived transition probabilities and sojourn time can serve as a significant reference for making targeted interventions for hypertension progression among the Chinese elderly population.

The Role of Socioeconomic Status, Family Resilience, and Social Support in Predicting Psychological Resilience Among Chinese Maintenance Hemodialysis Patients.

Objectives: Evidence regarding the possible influence of social factors on psychological resilience among maintenance hemodialysis patients is scarce. The aim of this study was to explore the relationship among socioeconomic status, family resilience, and social support, and psychological resilience among Chinese maintenance hemodialysis patients. Methods: This cross-sectional study was conducted in the hemodialysis centers of three comprehensive hospitals in China from September to December 2020 using convenience sampling. Two hundred fifty-eight patients receiving maintenance hemodialysis were investigated using a sociodemographic questionnaire, the Chinese version of the Medical Outcomes Study-Social Support Survey (MOS-SSS), Chinese Family Resilience Assessment Scale (C-FRAS), and Chinese version of the Conner and Davidson resilience scale (CD-RISC). Results: Maintenance hemodialysis patients reported a low level of physical resilience, with a score of (58.92 ± 15.27). Hierarchical linear regression analysis showed that education level (ß = 0.127, p = 0.018), maintenance of a positive outlook by the family (ß = 0.269, p = 0.001), positive social interaction support from the family (ß = 0.233, p = 0.002), and tangible support (ß = -0.135, p = 0.037) were significantly associated with psychological resilience. Conclusion: SES, family resilience and social support may be potential predictive factors of psychological resilience. Interventions to improve the family resilience and social support may be beneficial to promote the psychological resilience of Chinese maintenance hemodialysis patients.

Measurement and Evaluation of the Operating Efficiency of China's Basic Pension Insurance: Based on Three-Stage DEA Model.

PURPOSE: This paper aims to measure the operating efficiency of China's basic pension insurance from 2014 to 2019 in 31 provinces. METHODS: The three-stage DEA model was used to evaluate the operating efficiency of basic pension insurance in 31 provinces. RESULTS: On the whole, the operating efficiency of China's basic pension insurance was at a high level, but there was still room for improvement. GDP, urbanization level and scale of government public expenditure had a positive impact on the operating efficiency of regional basic pension insurance. In contrast, the old-age dependency ratio had a significant negative effect. There were noticeable regional differences in the operating efficiency of China's basic pension insurance, which showed a pattern of Central (0.742) >Eastern (0.689) >Western (0.505) after removing the influence of environmental variables. CONCLUSION: This study systematically analyzes the impact of external environmental regulations on China's basic pension insurance's operating efficiency and provides decision-making references for further improving the operating efficiency of China's basic pension insurance. In order to further optimize the allocation of basic endowment insurance, this paper proposes the following countermeasures and suggestions: (1) broaden investment channels and improve the investment efficiency; (2) increase supervision of social security departments and strengthen information disclosure; (3) unify the management of social basic pension insurance.

Occurrence of polycyclic aromatic hydrocarbons in fried and grilled fish from Shandong China and health risk assessment.

Diet is the main way for the human body to ingest polycyclic aromatic hydrocarbons (PAHs). In this study, the occurrence, dietary exposure, and health risks of 15 PAHs in 31 fried and grilled fish samples were investigated, which were collected from the Shandong Province of China. The results showed that benzo[a]pyrene (BaP) of 5 samples exceeded the European Union (EU) limit value. Naphthalene (NaP) and fluorene (Fle) were present in all samples, and the average concentration of ∑15PAHs was 91.1 µg/kg, with light PAHs dominated. The average contamination level of ∑15PAHs in fried and grilled fish was distributed differently, and there seemed to be more PAH contamination in the grilled samples. The results of the margin of exposure (MOE) suggested that PAH ingestion through fried and grilled fish did not imply significant toxicological concern for consumers in Shandong. The incremental lifetime cancer risk (ILCR) values for the consumption of fried and grilled fish were higher than 1 × 10-6, indicating a potential health risk in the adult population. The study provides baseline health information on PAH intake by residents due to dietary exposure to fried and grilled fish food products, suggesting that health risk monitoring of PAHs in such foods should be continually performed.

Machine learning-based operation skills assessment with vascular difficulty index for vascular intervention surgery.

An accurate assessment of surgical operation skills is essential for improving the vascular intervention surgical outcome and the performance of endovascular surgery robots. In existing studies, subjective and objective assessments of surgical operation skills use a variety of indicators, such as the operation speed and operation smoothness. However, the vascular conditions of particular patients have not been considered in the assessment, leading to deviations in the evaluation. Therefore, in this paper, an operation skills assessment method including the vascular difficulty level index for catheter insertion at the aortic arch in endovascular surgery is proposed. First, the model describing the difficulty of the vascular anatomical structure is established with characteristics of different aortic arch branches based on machine learning. Afterwards, the vascular difficulty level is set as an objective index combined with operating characteristics extracted from the operations performed by surgeons to evaluate the surgical operation skills at the aortic arch using machine learning. The accuracy of the assessment improves from 86.67 to 96.67% after inclusion of the vascular difficulty as an evaluation indicator to more objectively and accurately evaluate skills. The method described in this paper can be adopted to train novice surgeons in endovascular surgery, and for studies of vascular interventional surgery robots. Graphical abstract Operation skill assessment with vascular difficulty for vascular interventional surgery.

Effect of Land Expropriation on Land-Lost Farmers' Health: Empirical Evidence from Rural China.

With rapid urbanization and industry development, China has witnessed substantial land acquisition. Using the rural household survey data, this paper examines the impact of land expropriation on land-lost farmers' self-reported health with the ordered probit model and investigates the possible mechanisms. The results show that the land expropriation puts higher health risks over those land-lost farmers and the health status of land-lost farmers is significantly worse than that of those with land. Land expropriation has a negative impact on the land-lost farmer's health through income effects and psychological effects. The health status of land-lost farmers can be enhanced through amending current land requisition policies, increasing the amount of compensation, improving the earning capacity of land-lost farmers and strengthening mental health education.

[Assessment and application for the results of global intercalibration study of typical perfluoroalkyl substances in foods and human matrices].

OBJECTIVE: To analyze the result of global intercalibration study of typical perfluoroalkyl substances( PFASs) and their typical isomers in foods, human milk and serum from 2010 to 2017 and discuss the application of the result in quality assurance and control. METHODS: Z-scores were employed to assess the result of PFASs and their typical isomers from global intercalibration study. Combined with the concentrations of the samples, we have also analyzed the key point of the method. RESULTS: The absolute values of the Z-scores of most PFASs and their typical isomers were less than 1, indicating that the concentrations determined by our laboratory were satisfactory. CONCLUSION: The problems in the method could be found in time by participating in the global intercalibration study. Therefore we can improve the method to ensure the accuracy of the data and provide the effective technical support for determining the levels of PFASs and their typical isomers in foods, human milk and serum in China.

The effect of sampling strategies on assessment of water quality criteria attainment.

Sample locations for large river studies affect the representativeness of data, and thus can alter decisions made regarding river conditions and the need for interventions to improve water quality. The present study evaluated three water-quality sampling programs for Total Dissolved Solid (TDS) assessment in the Monongahela River from 2008 to 2012. The sampling plans cover the same 145 km of river but differ in frequency, sample location and type (e.g., river water sample vs drinking water plant intake sample). Differences resulting from temporal and spatial variability in sampling lead to different conclusions regarding water quality in the river (including regulatory listing decisions), especially when low flow leads to concentrations at or near the water quality criteria (500mg/L TDS). Drinking water samples exceeded the criteria 82 out of 650 samples (12.6%), while river water samples exceeded the criteria 47 out of 464 samples (10.1%). Different water sample types could provide different pictures of water quality in the river and lead to different regulatory listing decisions.

The roles of spatial pattern and size variation in shaping height inequality of plant population.

Game-theoretic models predict that there is an ESS height for the plant population to which all individual plants should converge. To attain this conclusion, the neighborhood factors were assumed to be equal for all the individual plants, and the spatial pattern and size variation of population were left without consideration, which is clearly not right for the scenario of plant competition. We constructed a spatially-explicit, individual-based model to explore the impacts of spatial structure and size variation on individual plant's height and population's height hierarchies under the light competition. The monomorphic equilibrium of height that all the individual plants will converge to only exists for a population growing in a strictly uniform spatial pattern with no size variation. When the spatial pattern of the population is non-uniform or there's size variation among individual plants, the critical heights that individual plants will finally reach are different from each other, and the height inequality at the end of population growth will increase when the population's spatial pattern's degree of deviation from uniform and population's size variation increase. Our results argue strongly for the importance of spatial pattern and neighborhood effects in generating the diversity of population's height growth pattern.

A sensitive and specific liquid chromatography/tandem mass spectrometry method for determination of echinacoside and its pharmacokinetic application in rats.

A rapid and sensitive method based on liquid chromatography/tandem mass spectrometry (LC/MS/MS) for the determination of echinacoside in rat plasma was established and fully validated. A single step of liquid-liquid extraction with n-butanol was utilized. Chromatographic separation of the analyte and the internal standard (IS), chlorogenic acid, from the sample matrix was performed using a Capcell-MG C(18) analytical column (100 2.0 mm x 5 microm), with a gradient of acetonitrile and water containing 0.1% acetic acid as the mobile phase. Detection was performed on a triple quadrupole tandem mass spectrometer equipped with electrospray ionization source operated in negative ion selected reaction monitoring mode. The method was linear in the concentration range 10-2500 ng/mL. The deviations of both intra- and inter-day precisions (RSD) were 7.1% and the assay accuracies were within 99.2-106.5%. Echinacoside proved to be stable during sample storage, preparation and analysis when an antioxidant solution was used. The method was successfully applied to a pharmacokinetic study in rats after an intragastric administration of echinacoside (100 mg/kg). With the lower limit of quantification at 10 ng/mL, this method proved to have sufficient selectivity, sensitivity and reproducibility for the pharmacokinetic study of echinacoside.