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Magnesia porous insulation materials were prepared via foam-gelcasting using industrial grade mid-range magnesia powder as the main raw materials, a copolymer of isobutylene and maleic anhydride (Isobam-104) as the dispersing and gelling agent, sodium carboxymethyl cellulose (CMC) as the foam stabilizing agent, and cetyltrimethylammonium bromide (CTAB) as the foaming agent. The effects of processing parameters such as amount of Isobam-104 (0.1 wt%, 0.15 wt%, 0.2 wt%, 0.25 wt%, and 0.3 wt%) and firing temperature (1300 ℃, 1350 ℃, and 1400 ℃) on magnesia porous insulation materials were investigated. In addition, the universal testing machine (WDW-100E) and the scanning electron microscope (SEM) were employed to characterize the firing samples. The results indicated that the compressive strength of the prepared samples increased with the increase in firing temperature, and the porosity decreased gradually. When the firing temperature was 1350 °C, the internal pores of the samples were uniformly distributed, the average pore size was in the range of 26.2 μm to 35.6 μm, and the compressive strength was in the range of 7.8 MPa to 11.5 MPa when porosity varied from 65.2% to 60.4%. The thermal conductivity of the prepared magnesia porous insulation materials was in the range of 0.481 W/(m·K) to 0.842 W/(m·K).

High pseudocapacitive activity of hydrated tungsten oxides (WO3·xH2O, x= 1 or 2) makes them promising materials for supercapacitors (SCs). During their synthesis, additives such as complexing agents and surfactants generally can only affect the morphology and/or size of the products. Here, we demonstrate that not only morphology and size of WO3·xH2O were affected, its phase composition could also change from WO3·2H2O to WO3·H2O simply by increasing the amount of sodium dodecyl sulfate (SDS) during its anodization synthesis. To the best of our knowledge, such a phenomenon has not been reported before. In addition, SDS introduced a special structure to the products, i.e., WO3·xH2O nanoplatelets constructed from nanoparticle multilayers with abundant nanogaps between the multilayers, which further arranged into nanoflowers with increased amounts of SDS. Benefiting from such a structure, low internal resistance, enhanced stability, and fast redox kinetics, the as-obtained WO3·xH2O/W-3 self-supporting electrode showed a high volumetric specific capacitance of 1402.92 F cm–3and good cycling stability (a capacity retention of 106% after 10 000 cycles). In addition, an all-solid-state asymmetric SC device based on WO3·xH2O/W-3 delivered high a volumetric energy density of 44.0 mW h cm–3at 0.5 W cm–3. Our method demonstrates a potential way to fabricate excellent self-supporting electrodes for SCs.

In mineral engineering, harmful foreign objects mixed in the feed can cause faults in the sizer crusher (Sizer). The traditional feed identification methods are inefficient and manual, which fail to adapt to the present production conditions of high belt speed, thick material layer, and large throughput. In previous studies, Sizer feed identification focused on single-component rather than mixed feeds. Therefore, we proposed a new Sizer mixed-feed identification method based on continuous wavelet transform (CWT) and squeeze-and-excitation residual network (SE-ResNet). First, the three-channel sensor signals acquired during the Sizer feeding process were subjected to CWT, and the resulting scalograms were fused as the image dataset. Second, a Sizer feed identification model based on SE-ResNet was designed for single-component and mixed-feed classification. Ablation studies and method comparisons were conducted to validate the performance of the proposed model. Finally, the method of this article was tested with industrial datasets to demonstrate its effectiveness and generalizability. The results show that the proposed method can achieve an accuracy of 85.99% ± 0.16% for Sizer mixed-feed identification. This method also significantly improves the identification ability of wood, which solves the problem of distinguishing between coal and wood in the feed. Besides, industrial tests suggest that our method has good Sizer mixed-feed identification performance with an average accuracy of 95.64% ± 1.77%, which can meet the demand of industrial production for the safe and smooth operation of the Sizer.

Three-dimensional numerical study of R134a flow boiling under overload was conducted based on the VOF model. A series of simulations were implemented with a 1.002 mm circular tube under six gravity levels ranging from 1 to 15 g and three directions (θ) ranging from 0° to 180° with mass fluxes of 200, 350, and 500 kg/m2 s, outlet vapor qualities of 0.041, 0.082, and 0.164, and saturation pressure of 0.71MPa. The gravity conditions were introduced into the momentum equation during the simulations. Comparisons among flow boiling characteristics under different gravity levels and directions are made, and significant effects of overload are found. With the increasing overload, the vapor phase distributions of flow boiling gradually turn into forms similar to ellipsoids/spheres, stratified flow, and elongated slugs, at θ = 0°, 90°, and 180°, respectively. Accordingly, the heat transfer coefficient keeps almost stable at θ = 0° and 180°, but decreases obviously at θ = 90°; the frictional pressure drop decreases at θ = 0°, decreases slightly at θ = 90°, but increases at θ = 180°. Making θ away from 90° is a potential method to avoid the flow boiling heat transfer deterioration under overload.

Conventional neural network (CNN) has been extensively applied in the field of fault diagnosis for multilevel inverter. However, most CNN based diagnostic strategies are typically implemented offline. To accomplish precise and online diagnosis for the open-circuit (OC) fault of three-level active neutral-point-clamped (3L-ANPC) inverter, the trained CNN is deployed into an edge computation board. Furthermore, this letter utilizes TensorRT to facilitate the lightweight design of the trained CNN, thereby accelerating the diagnosis speed. In order to simplify the offline training, a specific optimization framework is employed to achieve the automatic adjustment of hyperparameters. Comparative evaluations are performed to highlight the training performance and the generalization ability of the proposed CNN. Finally, the proposed online diagnosis is experimentally validated through a 3L-ANPC inverter fed permanent magnet synchronous motor (PMSM) drives.

Magnesia lightweight aggregates were synthesized by direct foaming method with light burned magnesia powder as raw material, sodium dodecyl benzene sulfonate (SDBS) as foaming agent and triethanolamine (TEA) as dispersant. Aqueous foams and magnesia foam slurry with foaming agent content of 3 wt% were prepared. The effects of different contents TEA (0.6 wt%, 1.0 wt%, 1.4 wt%, 1.8 wt%, and 2.2 wt%) on Zeta potential, viscosity, expansion ratio, contact angle, and surface tension of magnesia foam slurry were studied. The microstructure of aqueous foams and magnesia foam slurry were observed by optical microscope. After sintering at 1600 °C, the number and distribution of pores in the magnesia lightweight aggregates were analyzed by SEM. In aqueous foams, with the increase of TEA contents, the bubble liquid film became thicker and the shape became circle. In the magnesia foam slurry, when the TEA content was 1.4 wt%, the Zeta potential was 28.19 mV, the contact angle was 62.3°, and the surface tension was 45.2 mN∙m− 1. The adsorption free energy of magnesia particles was about 7.3 × 10− 9J. The bubble size distribution was 31.48 μm to 114.30 μm. In magnesia lightweight aggregates, the average pore size was 30.98 μm to 95.43 μm.

Background: Endoscopic submucosal dissection (ESD) was widely used for the removal of esophageal tumors, and post-endoscopic submucosal dissection electrocoagulation syndrome (PEECS) was one of the postoperative adverse events. The aim of this research was to develop and validate a model to predict electrocoagulation syndrome after endoscopic submucosal dissection of esophageal tumors. Materials and methods: Patients who underwent esophageal ESD in our hospital were retrospectively included. A predictive nomogram was established based on the results of multivariate logistic regression analysis, and bootstrapping resampling was used for internal validation. Besides, the clinical usefulness of the nomogram was evaluated using decision curve analysis (DCA) and clinical impact curve. Results: A total of 552 patients who underwent esophageal ESD were included in the study, and the incidence of PPECS was 12.5% (69/552). Risk factors associated with PEECS (p< 0.1) were analyzed by multivariate logistic regression analysis, and the final model included four variables, namely gender, diabetes, tumor size and operation time. The predictive nomogram was constructed based on the above four variables, and the area under the ROC curve (AUC) was 0.811 (95% CI 0.767–0.855). The calibration curve of the nomogram presented good agreement between the predicted and actual probabilities. DCA showed that the model improved patient outcomes by helping to assess the risk of PEECS in patients compared to an all-or-no treatment strategy. In addition, the clinical impact curve of the model also indicates that the nomogram has a high clinical net benefit. Conclusion: In conclusion, we have developed a predictive nomogram for PEECS after ESD for esophageal tumors with good predictive accuracy and discrimination. This predictive nomogram can be effectively used to identify high-risk patients with PEECS, which will help clinicians in clinical decision-making and early intervention.

• Mo-CoP/Co-N-C was first prepared by using petroleum pitch as a carbon source in a simple one-pot method. • The unique structure of Mo-CoP/Co-N-C provided a high specific surface area with abundant active sites. • Mo-CoP/Co-N-C had excellent catalytic performances toward HER, OER, and overall water splitting over a wide pH range. Designing highly active and stable noble-metal-free electrocatalysts for water splitting over a wide pH range is critical yet remains significantly challenging. In this work, Mo-doped CoP nanoparticles (Mo-CoP) supported and enwrapped by porous single-atomic-Co doped carbon framework (Co-N-C) were designed and prepared by a simple one-pot pyrolysis method. The Mo-CoP/Co-N-C electrocatalyst exhibits superior performance with low overpotentials of only 45 mV for hydrogen evolution reaction (HER) and 201 mV for oxygen evolution reaction (OER) in 1 M KOH at 10 mA cm–2 current density. Such excellent catalytic activity can be ascribed to enhanced intrinsic activity, large surface area, and highly exposed active sites. Meanwhile, an extremely small overpotential of only 250 mV is required for a large current density of 500 mA cm–2 in HER, which exceeds the performance of benchmark 10% Pt/C. Besides, Mo-CoP/Co-N-C also exhibits superior HER performance in acidic and neutral mediums, with overpotentials of only 41 and 98 mV in 0.5 M H 2 SO 4 , and 1 M PBS, respectively, thus achieving efficient water splitting at a wide pH range. The long-term stabilities are guaranteed with no significant decline of catalytic activities for more than 24 h in all electrolytes, which can be ascribed to the carbon layer encapsulation structure. Additionally, in overall water splitting, the electrocatalytic cell consisting of the as-synthesized Mo-CoP/Co-N-C only requires a cell voltage of 1.611 V at 100 mA cm–2 with excellent stability, exceeding that of the benchmark Pt/C||RuO2 couple (1.645 V at 100 mA cm–2). This work not only presents a highly efficient electrocatalyst for pH-universal water splitting but also provides a new perspective for the design and construction of transition metal catalysts with excellent stability. In this work, Mo doped CoP nanoparticles supported and enwrapped by porous Co-N-C framework (single-atomic-Co doped carbon) was prepared by using petroleum pitch as carbon source in a simple one-pot method. Here, asphalt was not only used as a carbon source, but also formed a carbon layer in the pyrolysis to enwrap the active components and limit the particle size. The Mo-CoP/Co-N-C electrocatalyst shows superior HER performance (45 mV@10 mA cm−2 in 1 M KOH, 41 mV@10 mA cm−2 in 0.5 M H2SO4, 98 mV@10 mA cm−2 in 1 M PBS) and excellent OER performance in a wide pH range. Particularly, Mo-CoP/Co-N-C exhibits the low overpotential of only 250 mV for HER at a large current density of 500 mA cm-2 in alkaline media, which exceeds the benchmark of 10% Pt/C. Meanwhile, the electrocatalysts show satisfactory stability with no significant decline of catalytic activities for 24 h at all pH values. In overall water splitting, the electrocatalyst only required a cell voltage of 1.611 V at 100 mA cm-2 with an excellent stability. The outstanding performance and stability of the Mo-CoP/Co-N-C can be attributed to the following aspects: (1) the electronic structure of CoP could be adjusted by Mo doping, resulting in enhanced hydrophilicity and enhanced intrinsic activity. (2) Co-N-C as a support can not only increase the specific surface area of the material and improve the conductivity, but also change the local electrochemical environment, accelerate the charge transfer, and expose more active sites. (3) Petroleum asphalt is used as a carbon source to form the encapsulation structure and limit the agglomeration of active components, which also guarantee its long-term stability. [Display omitted] [ABSTRACT FROM AUTHOR]

Objectives: The COVID-19 Healthcare Personnel Study is a longitudinal survey to assess the changing impact of the COVID-19 pandemic on the New York State health care workforce. We analyzed results from a follow-up survey of physicians, nurse practitioners, and physician assistants on the availability of equipment and personnel, work conditions, physical and mental health of participants, and impact of the pandemic on commitment to their profession.Methods: We conducted an online survey of all licensed New York State physicians, nurse practitioners, and physician assistants in April 2020 (N = 2105) and a follow-up survey in February 2021 (N = 978). We analyzed changes in item responses from baseline to follow-up. We calculated survey-adjusted paired ttests and odds ratios (ORs) using survey-adjusted generalized linear models controlling for age, sex, region of practice, and hospital versus non–hospital-based practice.Results: Twenty percent of respondents expressed continuing concern about personnel shortages at both baseline and follow-up. Respondents reported working approximately 5 more hours on average during a 2-week period at follow-up compared with baseline (78.1 vs 72.6 hours; P= .008). For 20.4% (95% CI, 17.2%-23.5%) of respondents, mental health issues had become persistent. More than one-third (35.6%; 95% CI, 31.9%-39.4%) of respondents reported that they thought about leaving their profession more often than once per month. The association between persistent mental and behavioral health issues and contemplating leaving one’s profession was significant (OR = 2.7; 95% CI, 1.8-4.1; P< .001).Conclusions: Interventions such as decreasing the number of hours worked, ensuring health care professionals do not work directly with patients while ill, and addressing shortages of personal protective equipment can help address concerns of the health care workforce.

Background: Endoscopic full-thickness resection is a common endoscopic procedure for treating gastrointestinal submucosal tumors. Nasogastric tube placement is frequently performed after abdominal surgery, but the routine use of this approach remains controversial. The aim of this research was to explore whether nasogastric tube placement after gastric endoscopic full-thickness resection is necessary. Methods: A retrospective study enrolled patients who underwent gastric endoscopic full-thickness resection in our hospital between January 2014 and January 2019, and all the patients had a tumor size ≤ 2 cm. The patients were divided into two groups according to whether a nasogastric tube was placed. Postprocedural adverse events and hospital stay duration were compared between the two groups using 1:1 propensity score matching. Results: A total of 461 patients were enrolled in this study, including 385 patients in the nasogastric tube group (NGT group) and 76 patients in the non-nasogastric tube group (non-NGT group). After matching, the baseline characteristics of 73 patients in the NGT group and 73 patients in the non-NGT group were balanced (p> 0.05). The postprocedural fever rate in the NGT group was significantly higher than that in the non-NGT group (23.3% vs. 9.6%, p= 0.044). 6.9% (5/73) of patients experienced severe nasogastric tube-related throat discomfort. However, the duration of hospitalization stay was not different between the two groups. Conclusions: For patients with tumor size ≤ 2 cm, routine nasogastric tube placement after gastric endoscopic full-thickness resection may be unnecessary.

ABSTRACTEucalyptus biomass-fired boilers generally experience severe problems with deposit formation and are expected to suffer from severe superheater corrosion at high temperatures due to the large alkali and chlorine content in eucalyptus biomass. The unique deposition layer structure and corrosion mechanism of eucalyptus-fired boilers are discussed in this paper. It was found that a unique sandwich like cell-membrane structure on the heating surface was formed in eucalyptus biomass-fired boilers. Chlorine acts as a catalyst, circulates the reaction and causes serious corrosion. The oxides at the junction of the corrosion layer and the matrix mainly penetrate along the grain boundary of the matrix, forming a unique network structure. There is obvious internal oxidation and mass transfer along the grain boundary in the matrix of 12Cr2MoWVTiB steel pipe, and no obvious internal oxidation in SA213T91 steel pipe due to its fine and uniform grains.

This article investigates the sliding wear behavior of ZTA (zirconia toughened alumina) particle (ZTAp)- and NbC (niobium carbide) particle (NbCp)-reinforced Fe60 matrix composites (ZTAp–NbCp/Fe60). ZTAp–NbCp/Fe60 was produced through vacuum sintering and tested on an M-2000 wear-testing machine. As revealed by the results, the wear loss increased with the increase in rotation speed and load. Abrasive wear occurred in the mild wear region; adhesive wear and serious abrasive occurred in the moderate wear region; and fatigue wear and ZTAp broken occurred in the severe wear region. According to the aforementioned conclusions, a more clean and intuitive wear mechanism diagram was established. In the process of wear, ZTAp was well combined with the matrix, and there was no crack at the interface. Meanwhile, in the wear process, ZTAp could block furrow, weaken the wear of the micro-convex ring, and improve the sliding wear performance of the composite material.

A creative approach for fabricating porous magnesia materials with improved mechanical and thermal properties using walnut shell powders as pore-forming agent combined with self-created porous magnesia aggregates is reported in the present work. The work focused on the microstructure and binding mechanism of the novel walnut shell powders (WSP), which treated by silica sol, aluminum sol, and oleic acid, and the properties and microstructure of porous magnesia materials. The results showed that the surface of the sols-treated walnut shell powders was spherical and significantly dispersed. The oleic acid-treated walnut shell powder (OWS) did not differ much from the original state; the surface was rough and agglomeration. The porous magnesia material with the addition of SWS has excellent properties, forms closed pores and low conductivity. When the SWS was added at 10%, the bulk density, porosity, compressive strength, and thermal conductivity of samples were 1.64 g·cm−3, 53.97%, 22 MPa, and 0.447 W/(m·K), respectively.

Copper-deficient Cu2–xS nanoparticles (NPs) are extensively exploited as a superior cation exchange (CE) template to yield sophisticated nanostructures. Recently, it has been discovered that their CE reactions can be facilely manipulated by copper vacancy density, morphology, and NP size. However, the structural similarity of usually utilized Cu2–xS somewhat limits the manipulation of the CE reactions through the factor of crystal structure because it can strongly influence the process of the reaction. Herein, we report a methodology of crystal structure transformation to manipulate the CE reactions. Particularly, roxbyite Cu1.8S nanodisks (NDs) were converted into solid wurtzite CdS NDs and Janus-type Cu1.94S/CdS NDs by a “full”/partial CE reaction with Cd2+. Afterward, the roxbyite Cu1.8S were pseudomorphically transformed into covellite CuS NDs. Unlike Cu1.8S, the CuS was scarcely exchanged because of the unique disulfide (S–S) bonds and converted into hollow wurtzite CdS under a more reactive condition. The S–S bonds were gradually split and CuS@CdS core@shell-type NDs were generated. Therefore, our findings in the present study provide not only a versatile technique to manipulate CE reactions in Cu2–xS NPs but also a better comprehension of their reaction dynamics and pathways.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.annemergmed.2006.05.022 Byline: Ru Ding, Melissa L. McCarthy, Guohua Li, Thomas D. Kirsch, Julianna J. Jung, Gabor D. Kelen Abstract: We identify patient characteristics associated with uncompleted visits to the emergency department (ED). Author Affiliation: Department of Emergency Medicine, Johns Hopkins University School of Medicine, Baltimore, MD. Article History: Received 12 October 2005; Revised 5 January 2006; Revised 19 April 2006; Revised 8 May 2006; Accepted 24 May 2006 Article Note: (footnote) Supervising editor: Brent R. Asplin, MD, MPH Author contributions: All of the authors contributed to the scientific content of the article. All authors participated in the concept and design and interpretation of the data, as well as revising the manuscript. RD, MLM, and GL are responsible for the analysis of the data. MLM takes responsibility for the manuscript as a whole. Funding and support: The authors report this study did not receive any outside funding or support. Publication dates: Available online June 30, 2006. Reprints not available from the authors.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.annemergmed.2005.11.018 Byline: Susan P. Baker (a)(b), Jurek G. Grabowski (b), Robert S. Dodd (a), Dennis F. Shanahan (a), Margaret W. Lamb (a), Guohua H. Li (a)(b) Abstract: In recent years, air transport of patients has been associated with disproportionate increases in crashes and deaths. We identify factors related to fatal outcome in air medical helicopter crashes and suggest preventive measures. Author Affiliation: (a) Center for Injury Research and Policy, Johns Hopkins University Bloomberg School of Public Health, Baltimore, MD (b) Department of Emergency Medicine, Johns Hopkins University School of Medicine, Baltimore, MD. Article History: Received 29 July 2005; Revised 14 October 2005; Revised 1 November 2005; Accepted 9 November 2005 Article Note: (footnote) Supervising editor: Arthur L. Kellermann, MD, MPH Author contributions: SPB, RSD, and MWL conceived the study. SPB and GHL obtained research funding. SPB and MWL read and coded the case reports. SPG and JGG supervised data collection, and JGG performed data analyses. SPB, RSD, DFS, and MWL interpreted the results of analyses. GHL was the statistical consultant. SPB drafted the manuscript, and all authors contributed substantially to its revision. SPB takes responsibility for the paper as a whole. Reprints not available from the authors. Funding and support: This research was supported by the Center for Injury Research and Prevention, Centers for Disease Control and Prevention (grant CCR302486) and in part by grant R01AA09963 from the National Institutes of Health. Reprints not available from the authors.

To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.annemergmed.2005.07.009 Byline: Marian E. Betz, Guohua Li Abstract: Epidemiologic studies of injury morbidity have relied primarily on data from emergency departments (EDs) and hospital admissions. We seek to assess the incidences and characteristics of acute injuries treated at EDs and other ambulatory care settings. Author Affiliation: From Johns Hopkins University School of Medicine (Betz), and the Department of Emergency Medicine, Johns Hopkins School of Medicine (Li), Baltimore, MD Article History: Received 7 March 2005; Revised 13 May 2005; Revised 20 June 2005; Accepted 1 July 2005 Article Note: (footnote) Supervising editor: Arthur L. Kellermann, MD, MPH Author contributions: GL conceived the study and obtained research funding. MEB obtained, managed, and analyzed the data. GL provided statistical advice. MEB drafted the manuscript, and both MEB and GL contributed substantially to its revision. MEB takes responsibility for the paper as a whole. Funding and support: This research was supported in part by grants R01 AA09963 and R01 AG013642 from the National Institutes of Health and by grant CCR302486 from the Centers for Disease Control and Prevention.

Objective: Although a popular endeavor, boxing has fallen under increased scrutiny because of its association with traumatic brain injury. However, few studies have investigated the overall epidemiology of boxing injuries [...]

Objectives: This study aimed to assess the impact of the 1997 Arkansas helmet law repeal on motorcycle registrations, crash and fatality risks, and alcohol involvement in motorcycle crashes. Methods: Annual [...]

Plasma ignition technology is the research frontier in the field of energy and power. In this paper, a novel type of plasma jet igniter called pre-combustion plasma jet igniter is designed and the experimental results show that it has great potential in strengthening jet stiffness, improving ignition energy, decreasing ignition energy consumption and reducing igniter ablation. The value S called jet stiffness is defined for the first time to reflect the stiffness characteristics of the plasma jet. And the effects of jet gas flow rate, fuel-air ratio and input current on the jet stiffness are investigated experimentally. The experimental results show that the stiffness of the pre-combustion plasma jet is significantly stronger than that of the air plasma jet. When the total jet gas flow rate is increased from 16 L/min to 40 L/min, the stiffness of the air plasma jet and the pre-combustion plasma jet are increased by 73.3 % and 27.2 % respectively. When the current value reaches 30 A, the jet stiffness is increased by about 70 % compared to the input current of 20 A.

Arsenic (As) pollution is a serious worldwide problem that requires urgent attention, as this heavy metal poses a serious threat to both human and environmental health. Here, Fe3O4was used as an in situFe source removal agent to study the effect of pre-dissolution time on arsenic removal by Fe3O4. Fe3O4is uniquely well suited for the treatment of industrial wastewater due to its structural characteristics. Assays were conducted at a Fe/As molar ratio of 3 : 1, and these components were pre-dissolved at 23 °C for 2 h to establish the optimal initial conditions for Fe-mediated arsenic removal at a high temperature. The adsorption capacity of arsenic in the pre-dissolution stage was 143.99 mg g−1. After adjusting the pH value to 2.5 and allowing the Fe and As to react at 90 °C for 24 h, 99.1% of the As was precipitated from the wastewater with an initial arsenic concentration of 8276.1 mg L−1. The leaching of this As-bearing precipitate was as low as 0.3 mg L−1. As a solid iron source, Fe3O4provides a large number of nuclear sites for arsenic precipitation in the pre-dissolution stage and the high-temperature synthesis stage. At the same time, the supersaturation of the system was regulated by controlling the reaction and dissolution characteristics. Upon further characterization, the removal of As by Fe3O4in the pre-dissolution process was attributed to a combination of physical adsorption and chemical precipitation.

Background and aims: The American Society for Gastrointestinal Endoscopy (ASGE) has developed a complexity-grading system for endoscopic retrograde cholangiopancreatography (ERCP) to predict technical success and adverse events. This study aimed to assess the association between the degree of difficulty for ERCP and the rates of success and adverse event, in turn demonstrating the validity and practicality of this system. Methods: ERCP procedures performed in the First Affiliated Hospital of Nanchang University from January 2010 to December 2019 were retrospectively reviewed. Procedural success and adverse events were recorded based on difficulty level according to the ASGE-grading system. Results: A total of 20,652 ERCP procedures performed during the study period were analyzed, including 1908 procedures considered grade 1(9.2%), 10,170 procedures considered grade 2 (49.2%), 7764 procedures considered grade 3 (37.6%), 810 procedures considered grade 4 (3.9%). The overall success rate increased from 92.8% in 2011–2015 to 94.0% in 2016–2020, while the distribution of procedures and the incidence of complications showed little variation. The success rate revealed a significantly decreasing trend with increasing difficulty (ranging from 55.6 to 98.6%), mainly for biliary diseases. In addition, the difficulty scale was not associated with any differences in the rate of adverse event, except for the pancreatitis for grade 1 procedures, which had a low incidence. Conclusions: The ASGE-grading system can help predict the success rate of ERCP procedures but showed poor performance in predicting adverse events. Further exploration may be required to improve the grading system by adjusting or including certain clinical parameters, and to validate the system for extrapolation to other endoscopy units.

In China, depressive disorders have been estimated to be the second leading cause of years lived with disability. However, nationally representative epidemiological data for depressive disorders, in particular use of mental health services by adults with these disorders, are unavailable in China. The present study, part of the China Mental Health Survey, 2012–15, aims to describe the socioeconomic characteristics and the use of mental health services in people with depressive disorders in China.

Background: The goal of this study was to compare the efficacy and safety of needle-knife fistulotomy (NKF) to that of conventional cannulation methods (CCMs) when used for primary biliary access in patients with duodenal papillary tumors. Methods: Consecutive patients who had duodenal papillary tumors and who underwent endoscopic retrograde cholangiopancreatography (ERCP) were retrospectively enrolled. Successful cannulation rates, cannulation and procedure times, and the prevalence of adverse events were compared between the NKF and CCM groups. Results: A total of 404 patients (NKF, n= 124; CCM, n= 280) with duodenal papillary tumors were included. The primary and overall cannulation rates were 92.1% (372/404) and 96.0% (388/404), respectively. Compared to CCMs, NKF was associated with a significantly higher successful cannulation rate (99.2% versus 88.9%, P&lt; 0.001) and significantly lower cannulation times (2.1 ± 2.0 min versus 4.7 ± 5.2 min), procedure times (8.8 ± 3.8 min versus 12.9 ± 7.6 min), and unintentional pancreatic duct cannulation rates (1.6% versus 20%), with P&lt; 0.001 for all. Overall adverse events occurred less frequently in the NKF group (3.2% versus 10.7%, P= 0.011). Of these adverse events, post-ERCP pancreatitis (PEP) was significantly lower in the NKF group than in the CCM group (1.6% versus 6.8%, P= 0.03). Bleeding and cholangitis rarely occurred with either cannulation method (0.8% versus 2.1%, P= 0.681, and 0.8% versus 1.7%, P= 0.671, respectively). Conclusion: NKF is a more effective and safer procedure than CCMs for patients with duodenal papillary tumors.

Children who use skateboards have a higher risk of injury than children who use roller skates or in-line skates. Data from 79 US hospitals reveal that 154 roller skaters, 190 in-line skaters and 254 skateboarders were treated for injuries between 1988 and 1997. Overall, three-quarters were male and 37% had a head injury. Half of the skateboarders had a head injury compared to 34% of the in-line skaters and 19% of the roller skaters. Skateboarders were twice as likely to have severe injuries as in-line skaters and eight times more likely than roller skaters. Skateboarders had longer hospital stays than the other children.

Background: Change in body weight is a potentially modifiable risk factor for hip fracture in older women but, to our knowledge, its relationship to risk in older men has not been reported previously. Objective: To investigate the effects of weight loss and weight gain from age 50 years to old age on the risk of hip fracture among elderly men. Methods: The association between weight change and risk of hip fracture was studied in a cohort of 2413 community-dwelling white men aged 67 years or older from 3 sites of the Established Populations for Epidemiologic Study of the Elderly. Results: The older men in this study, observed for a total of 13 620 person-years during the 8 years of follow-up, experienced 72 hip fractures, yielding an overall incidence rate of 5.3 per 1000 person-years. Extreme weight loss ([is greater than or equal to] 10%) beginning at age 50 years was associated in a proportional hazards model with increased risk of hip fracture (relative risk, 1.8; 95% confidence interval, 1.04-3.3). Weight loss of 10% or more was associated with several indicators of poor health, including physical disability, low mental status score, and low physical activity (P [is less than] .05). Weight gain of 10% or more beginning at age 50 years provided borderline protection against the risk of hip fracture (relative risk, 0.4; 95% confidence interval, 0.1-1.00). Conclusions: Despite differences between older men and women in the incidence of and risk factors for hip fracture, weight history is also an important determinant of the risk of hip fracture among older men. Weight loss of 10% or more beginning at age 50 years increases the risk of hip fracture in older white men; weight gain of 10% or more decreases the risk of hip fracture. The relationship between extreme weight loss and poor health suggests that weight loss is a marker of frailty that may increase the risk of hip fracture in older men. Physicians should include weight history in their assessment of the risk of hip fracture among older men. Arch Intern Med. 1998;158:990-996

Objective: To examine the characteristics of unintentional and assaultive firearm-related pediatric injuries treated in trauma centers. Design: Comparative analysis of patients 14 years or younger who were admitted to the trauma centers because of unintentional firearm-related injuries (n= 292) vs assaultive firearm-related injuries (n=457). Setting: Sixty-eight trauma centers or children's hospitals in the continental United States and Canada that reported data to the National Pediatric Trauma Registry from January 1, 1990, through December 31, 1994. Main Outcome Measures: Frequency distributions of firearm-related injuries in relation to intent and injury circumstances, odds ratios (ORB) on the intent of injury being assaultive, injury severity scales, and in-hospital fatality rates. Results: The frequency of unintentional firearm-related injuries rose in the afternoons peaking between 4 and 5 PM; they predominantly occurred at home (89%). Assaultive firearm-related injuries peaked sharply between 8 and 9 PM and usually occurred on roads or in other public places (63%). About 3 times as many boys as girls were harmed in firearm-related injuries. Given a firearm-related injury resulting in admission to a trauma center, the adjusted OR of it being assaultive was 2.8 (95% confidence interval [CI], 1.6-4.6) if the victim was a girl, 4.9 (95% CI, 3.1-7.8) if the shooting occurred at night, 2.6 (95% CI, 1.6-4.2) if the shooting occurred on a weekday, and 21.1 (95% CI, 9.1-49.4) if the shooting occurred on a road. Injury patterns and severity were similar between patients with unintentional and assaultive injuries. Overall, 19% of the patients sustained head injuries, which contributed to 90% of the in-hospital deaths. Conclusions: Marked differences in injury circumstances exist between unintentional and assaultive firearm-related injuries among children. The late afternoon hours when many children have come home from school but their parents may still be working have the highest frequency of unintentional firearm-related injuries. The evening peak of assaultive injuries may be related to drug-related and gang-related violence. While it is important to reduce the access of firearms to children, school-based extracurricular and community-based social services should be considered in developing intervention programs., Firearm-related injuries in children may differ according to type of injury event and type of victim. Researchers reviewed records of 749 pediatric trauma patients seen in 68 hospitals for firearm-related injuries. A total of 292 (39%) injuries were unintentional and 457 (61%) were assaultive injuries. Unintentional firearm-related injuries were more common in the afternoon, after school hours, and at home. Assaultive injuries happened between 8 and 9 p.m. and on roads or public places. Schools and communities should develop programs to supervise children during these times.

Background Anemia is associated with intensive care unit (ICU) outcomes, but data describing this association in sub-Saharan Africa are scarce. Patients in this region are at risk for anemia due to endemic conditions like malaria and because transfusion services are limited.Methods This was a prospective cohort study of ICU patients at Kamuzu Central Hospital (KCH) in Malawi. Exclusion criteria included age <5 years, pregnancy, ICU readmission, or admission for head injury. Cumulative incidence functions and Fine-Gray competing risk models were used to evaluate hemoglobin (Hgb) at ICU admission and hospital mortality.Results Of 499 patients admitted to ICU, 359 were included. The median age was 28 years (interquartile ranges (IQRs) 20-40) and 37.5% were men. Median Hgb at ICU admission was 9.9 g/dL (IQR 7.5-11.4 g/dL; range 1.8-18.1 g/dL). There were 61 (19%) patients with Hgb < 7.0 g/dL, 59 (19%) with Hgb 7.0-8.9 g/dL, and 195 (62%) with Hgb ≥ 9.0 g/dL. Hospital mortality was 51%, 59%, and 54%, respectively. In adjusted analyses, anemia was associated with hospital mortality but was not statistically significant.Conclusions This study provides preliminary evidence that anemia at ICU admission may be an independent predictor of hospital mortality in Malawi. Larger studies are needed to confirm this association.

To simultaneously optimize the surface quality and machining efficiency of the electrical discharge machining (EDM) processes used to produce titanium alloy quadrilateral group small hole parts, a combined “EDM + AFM” machining technology is proposed in this paper as an efficient and high-quality machining approach. In the proposed method, TC4 titanium alloy is first machined using the EDM process with graphite electrodes and the abrasive flow machining (AFM) process is then used to finish the machined surface. The effects of various electrical parameters on EDM-derived surface quality and improvements in EDM-derived quality under the application of AFM were assessed and, using the final surface roughness as a constraint condition, the effects of various combinations of EDM and “EDM + AFM” on efficiency were studied. The results revealed that the thickness and surface roughness of the superficial recast layer of the TC4 titanium alloy increase with both current and pulse width; in particular, increasing these parameters can increase the surface roughness by two to three grades. Following AFM, the alloy has a more uniform hardness distribution and the surface stress state changes from tensile to compressive stress, indicating that the combined “EDM + AFM” machining scheme can significantly enhance the surface quality of EDM-produced titanium alloy quadrilateral small group holes. The combined scheme achieves a balancing point beyond which increasing the roughness or the number of machining holes enhances either the machining efficiency or the machining surface quality. In the case of typical titanium alloy quadrilateral group small hole parts, the combined machining process can improve the finishing efficiency and total machining efficiency by 71.2% and 25.36%, respectively.