85 research outputs found

    Spatial Distribution Characteristics and Evolution Pattern of Air Quality in Henan Province

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    Urban air pollution is an urgent problem to be solved in the process of rapid urbanization and economic development in China. Based on the daily average data of urban air quality index of Henan province from 2015.1 to 2018.12, this paper utilizes cluster analysis, trend surface analysis and centralizing evolution analysis methods to study the spatial distribution characteristics and evolution pattern of urban air quality in the province. The results show that the air quality in the province presents five air quality systems, which seriously relate to the terrain, the air quality index of the northern cities has always been higher than that of the southern cities, with the latitude increases, the air quality index gradually increases, and the increase rate in the middle region is significantly higher than that in both sides. The province weathers, in the study period, shows 4 grades as good & moderate, lightly polluted, moderately polluted and heavily polluted. Lightly polluted weathers first appear in central and southern cities, moderately polluted and heavily polluted weather first appear in the northern cities, and then spread to the rest cities of the province

    Characteristics of mass-forming autoimmune pancreatitis commonly misdiagnosed as a malignant tumor

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    ObjectiveThis study aimed to explore the clinical characteristics and differential diagnosis of patients with autoimmune pancreatitis (AIP) and pancreatic cancer to prevent misdiagnosis and mistreatment.MethodsThe clinical data of patients with AIP with suspected pancreatic or bile duct malignancy and pancreatic cancer were retrospectively analyzed. The risk factors and the diagnostic value of IgG4 and Tbil levels before treatment for AIP was investigated. Moreover, the imaging features and response to hormone therapy were analyzed.ResultsAIP was commonly observed in men. Compared to patients with pancreatic cancer, the incidence of poor appetite and weight loss and carbohydrate antigen 19-9 (CA19-9) level was lower in patients with AIP, while the immunoglobulin G4 (IgG4) level was higher (p < 0.05). After treatment, the IgG4 and CA19-9 levels in patients with AIP were decreased (p < 0.001). IgG4 level before treatment (OR = 2.452, 95%CI: 1.180–5.096, P = 0.016) and total bilirubin (Tbil) level before treatment (OR = 0.992, 95%CI: 0.985–0.998, P = 0.013) were independent risk factors of AIP. Furthermore, the diagnostic value of IgG4 level before treatment, Tbil level before treatment, IgG4/Tbil before treatment, and a combination of these indicators was high. Moreover, 15 (68.18%) patients with AIP had space-occupying lesions of the pancreas, and 16 (72.73%) had autoimmune cholangitis. Most patients with AIP were sensitive to hormone therapy.ConclusionsThe Tbil and IgG4 levels, imaging findings, and hormone therapy reactivity could differentiate AIP from pancreatic cancer. A combination of IgG4, Tbil, and IgG4/Tbil before treatment might be a promising diagnostic biomarker for AIP

    Regional scale cropland carbon budgets: Evaluating a geospatial agricultural modeling system using inventory data

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    Accurate quantification and clear understanding of regional scale cropland carbon (C) cycling is critical for designing effective policies and management practices that can contribute toward stabilizing atmospheric CO2 concentrations. However, extrapolating site-scale observations to regional scales represents a major challenge confronting the agricultural modeling community. This study introduces a novel geospatial agricultural modeling system (GAMS) exploring the integration of the mechanistic Environmental Policy Integrated Climate model, spatially-resolved data, surveyed management data, and supercomputing functions for cropland C budgets estimates. This modeling system creates spatiallyexplicit modeling units at a spatial resolution consistent with remotely-sensed crop identification and assigns cropping systems to each of them by geo-referencing surveyed crop management information at the county or state level. A parallel computing algorithm was also developed to facilitate the computationally intensive model runs and output post-processing and visualization. We evaluated GAMS against National Agricultural Statistics Service (NASS) reported crop yields and inventory estimated county-scale cropland C budgets averaged over 2000e2008. We observed good overall agreement, with spatial correlation of 0.89, 0.90, 0.41, and 0.87, for crop yields, Net Primary Production (NPP), Soil Organic C (SOC) change, and Net Ecosystem Exchange (NEE), respectively. However, we also detected notable differences in the magnitude of NPP and NEE, as well as in the spatial pattern of SOC change. By performing crop-specific annual comparisons, we discuss possible explanations for the discrepancies between GAMS and the inventory method, such as data requirements, representation of agroecosystem processes, completeness and accuracy of crop management data, and accuracy of crop area representation. Based on these analyses, we further discuss strategies to improve GAMS by updating input data and by designing more efficient parallel computing capability to quantitatively assess errors associated with the simulation of C budget components. The modularized design of the GAMS makes it flexible to be updated and adapted for different agricultural models so long as they require similar input data, and to be linked with socio-economic models to understand the effectiveness and implications of diverse C management practices and policies

    Pepsinogen Serology and Gastritis OLGA Staging in Mucosal Atrophy Assessment: A Cross-Sectional Study Involving East China Endoscopy Population

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    The histological gastric stage (OLGA) plays an important role in evaluating gastric atrophy, a symptom which suggests a risk of gastric cancer (GC). However, gastroscopy is an invasive examination, which has limited application in populations undergoing physical examination. Serum pepsinogen (PG) and gastin-17 (G-17) levels are noninvasive indexes which are recommended when screening for GC. We aim to explore the correlation between PG/G-17 and OLGA stage, in order to provide reliable indexes for GC screening. The study included 453 asymptomatic individuals from East China undergoing physical examination, who then underwent endoscopy including collection of biopsy samples. Assays for serum PG, G-17, and Helicobacter pylori (Hp) were performed. Atrophy of gastric mucosa was graded according to OLGA for each individual. 453 participants, average age 52.46±10.30 years, 253 male and 200 female, were included. In the asymptomatic physical examination population, serum PGI, PGII, and PGR levels decreased with increasing OLGA scores. PGI and PGR were inversely correlated with increasing OLGA stage in both Hp-positive and Hp-negative groups. The levels of serum PGI, PGII, and G-17 in the Hp-positive group were higher than those in the Hp-negative group; conversely, the PGR levels were lower. Furthermore, OLGA scores increased with age in the Hp-positive group. In conclusion, there is a significant correlation between OLGA stage and serum PG in populations from East China undergoing physical examination. Serum PG and G-17 combined with Hp test plays an important role in evaluating gastric atrophy

    Poly(ether sulfone) nanoparticles and controllably modified nanoparticles obtained through temperature-dependent cryogelation

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    Poly(ether sulfone) (PES) nanoparticles (NPs) have broad application prospects in the field of nanomedicine. However, the current techniques could not be used to create PES-based NPs because of a lack of sophisticated equipment. In this study, a temperature-dependent cryogelation process was developed to fabricate PES NPs through PES self-assembly under unusually low polymer concentrations in the absence of any nanomanufacturing equipment or synthesis steps. The morphologies of the prepared NPs varied with the concentration difference of the initial PES solutions, and the diameter of the polymer particles reached about 50 nm with a high monodispersity. Furthermore, cocryogelation was explored in a novel manner to introduce two representative reversible addition-fragmentation chain-transfer (RAFT) agents onto the PES NPs separately for the following modification. Then, surface-initiated RAFT polymerization was also conducted to enable the controllable variation of the polymer brushes outside the NPs to verify their scalability for further application. (c) 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47485

    Influence of Nozzle Design on Flow Characteristic in the Continuous Casting Machinery

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    In the process of continuous casting, the submerged nozzle will affect the flow of the liquid steel and the quality of the slab. In this paper, three nozzle structures are investigated to compare the influence of the nozzle structure on the flow and solidification of steel. In addition, the flow field, flow velocity, recirculation zone, free-surface turbulent kinetic energy and heat transfer of fluid steel are calculated. The results demonstrate that among the three nozzles, the structure of the B nozzle is the best. The fluid steel flows out from the nozzle at a certain angle. The flow rate and momentum of the fluid steel gradually decrease, and two split streams are formed when the main stream approaches the narrow surface. The spherical area at the bottom of the nozzle can reduce the flow rate of the fluid steel at the outlet of the nozzle, leading to a stable liquid level. The turbulent kinetic energy of the free liquid surface of nozzle A is the largest, reaching 0.00204 m2·s−2. The turbulent kinetic energy of nozzle C is slightly lower (0.00193 m2·s−2), and the free-liquid-surface turbulent kinetic energy of nozzle B (0.00154 m2·s−2) is the smallest. The surface velocity of nozzle B is also lower than that of A and C because the vortex center of the upper recirculation zone of nozzle B is closer to the narrow surface. The results show that the B nozzle is optimal, and this model can provide theoretical guidance for the design of a nozzle during the continuous casting

    Study on the Seismic Behavior of a Steel Plate–Concrete Composite Shear Wall with a Fishplate Connection

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    The steel plate–concrete composite shear wall (SPCSW), having been widely applied to several super high-rise buildings, is currently regarded as a new type of lateral load-resisting structure. The SPCSW design does not consider the connection to the surrounding structure, normally envisaged as a buttweld connection, while the fishplate lap connection tends to be applied in construction. To explore the fishplate lap connection to achieve the performance standard of SPCSW, in this paper, an SPCSW with a fishplate connection is modeled using ABAQUS to investigate the hysteretic behavior under constant axial force and horizontal cyclic loads. Through the hysteresis curve and a load–displacement skeleton curve, the effects of fishplate thickness and lap length on its hysteretic behavior are studied. The results show that increasing the fishplate thickness contributes to a slight increase in the bearing capacity and energy dissipation and has little influence on stiffness degradation. When the fishplate thickness is more than half the steel plate thickness, the strength and energy dissipation of an SPCSW with a fishplate connection can reach the level of an SPCSW without a fishplate connection. The bearing capacity and stiffness of the SPCSW increase with the increase in lap length. When the lap length is greater than 50 mm, the strength, stiffness and energy dissipation capacity of an SPCSW with a fishplate connection are superior to those without fishplate connections. Finally, engineering suggestions on fishplate connections are put forward

    Comparison between Endoscopic Submucosal Dissection and Surgery in Patients with Early Gastric Cancer

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    Background: Endoscopic submucosal dissection (ESD) has become a preferred treatment option for early gastric cancer (EGC). This study aimed to compare the clinical outcomes of ESD and surgical resection for EGC. Methods: This was a retrospective case–control study. Patients with a diagnosis of EGC who underwent ESD or surgery in our hospital from 2011 to 2020 were enrolled. We compared the clinical characteristics and treatment outcomes of these two groups according to propensity score-matching. The primary outcome comparison was overall survival (OS). Secondary outcomes were disease-specific survival (DSS), recurrence-free survival (RFS), and treatment-related events. Results: In the matched cohort, the ESD group showed comparable OS, RFS, and DSS with the surgery group. Statistical differences were shown in blood loss and adverse events. Furthermore, the ESD group showed lower hospital cost, as well as a shorter operative time and hospital duration than the surgery group. The R0 resection and recurrence rates were similar between the two groups. In Cox regression analysis, age, tumor size, poor differentiation, and lymphovascular invasion were regarded as independent factors of OS. Conclusions: With sufficient safety and advantages, ESD can be a first-line treatment of EGC. Preoperative evaluation is vital to the appropriate treatment and prognosis
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