18 research outputs found

    Effects of Ball Milling Processing Conditions and Alloy Components on the Synthesis of Cu-Nb and Cu-Mo Alloys

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    The effects of processing parameters in ball milling and the different behaviors of Cu-Nb and Cu-Mo alloys during milling were investigated. High powder yields can be obtained by changing the BPR value and ball size distribution and no clear dependence of BPR value on powder yield can be found from the experiment results. The addition of oxygen can largely reduce the effect of excessive cold welding during ball milling. A “two-step” ball milling method was introduced to evaluate the different evolution processes and morphologies in different alloys. With 8 h pre-milling, this method considerably benefits the oxidation process of Mo and shows its promising potential in the synthesis of immiscible alloys. Based on the experiment results and analysis, we suggest that the different behaviors of Cu-Nb and Cu-Mo alloys are related to the shear modules and different tendencies to be oxidized

    IMPROVEMENT ON THE SUPPORT STRUCTURE OF THE SUPERCONDUCTING SADDLE MAGNET SSM-3

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    Le travail pour l'amélioration de la structure supportante de l'aimant SSM-3 ("adiabatically stable, saddle magnet") est résumé. Cet aimant atteint la performance en échantillon court.The work related to support structure improvement, which allows the adiabatically stable saddle magnet SSM-3 to achieve "short-sample" performance, has been summarized

    A novel approach for assessing osteoporosis utilizing DXA, HU and VBQ

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    Objective: To precisely assess preoperative osteoporosis in patients, a more precise method for evaluating osteoporosis is being developed to better guide the use of bone cement reinforced screws. Method: The retrospective analysis was conducted on patients who underwent posterior lumbar decompression and fusion internal fixation at Shanghai Tongren Hospital.The general information, bone mineral density assessment data, Fracture risk prediction rate(WHO Fracture Risk Assessment Tool (FRAX)), and whether to use cement reinforced screws were collected. Definition of combination method: T value ​3.5.The diagnostic rates of osteoporosis were compared between dual energy x-ray absorptiometry(DXA), Hounsfield Units(HU), Vertebral Bone Quality (VBQ), National Bone Health Alliance(NBHA), and combination methods, and the correlation between different methods was analyzed. Binary logistic regression was used to analyze the significant influencing factors of the use of cement-reinforced screws. Result: A total of 178 patients were enrolled in the study, aged 65.73 ​± ​14.43 years, 121 female, 57 male, Body Mass Index(BMI) was 22.88 ​± ​3.52, 57 (32.0%) used cement reinforced screws, and 14 (7.9%) had previous fracture history.The diagnostic rates of osteoporosis by DXA, HU, VBQ, NBHA and combination method were 22.5% (40/178), 47.2% (84/178), 56.2% (100/178), 64.0% (114/178) and 75.8% (135/178), respectively.HU, VBQ, NBHA, and combination methods were significantly different from DXA in the diagnosis rate of osteoporosis (P ​< ​0.001). Binary Logistics regression showed that age, T value, HU value, and VBQ value significantly influenced bone cement screw use, and the odds ratio of VBQ was 4.315. The prediction accuracy of the regression equation was 90.4%, the area under the receiver operator characteristic(ROC) curve was 0.974, and the Youden index was 0.830. Conclusion: Currently, the DXA method widely used for diagnosing osteoporosis yields false negative results and there are significant discrepancies among different diagnostic methods. The combined approach exhibits a higher detection rate (75.8%). Age, T value, HU value, and VBQ value significantly influence the use of cement screws with a regression equation accuracy of 90.4%. Cement-reinforced screws are recommended when osteoporosis is determined by a combination method

    EXPERIENCES IN DEVELOPING THE HIGH CURRENT DENSITY WAX-FILLED SUPERCONDUCTING SADDLE MAGNETS

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    La conception, la fabrication et les résultats expérimentaux de trois aimants ("saddle magnets") sont décrit(e)s. Les expériences pendant le développement sont résumées.The design, construction technology and test results of three model saddle magnets are described. The main research and development experiences are summarized

    Perioperative risk factors for postoperative pneumonia after major oral cancer surgery: A retrospective analysis of 331 cases

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    <div><p>Objective</p><p>Postoperative pneumonia (POP) is common and results in prolonged hospital stays, higher costs, increased morbidity and mortality. However, data on the incidence and risk factors of POP after oral and maxillofacial surgery are rare. This study aims to identify perioperative risk factors for POP after major oral cancer (OC) surgery.</p><p>Methods</p><p>Perioperative data and patient records of 331 consecutive subjects were analyzed in the period of April 2014 to March 2016. We individually traced each OC patient for a period to discharge from the hospital or 45 days after surgery, whichever occur later.</p><p>Results</p><p>The incidence of POP after major OC surgery with free flap construction or major OC surgery was 11.6% or 4.5%, respectively. Patient-related risk factors for POP were male sex, T stage, N stage, clinical stage and preoperative serum albumin level. Among the investigated procedure-related variables, incision grade, mandibulectomy, free flap reconstruction, tracheotomy, intraoperative blood loss, and the length of the operation were shown to be associated with the development of POP. Postoperative hospital stay was also significantly related to increased incidence of POP. Using a multivariable logistic regression model, we identified male sex, preoperative serum albumin level, operation time and postoperative hospital stay as independent risk factors for POP.</p><p>Conclusion</p><p>Several perioperative risk factors can be identified that are associated with POP. At-risk oral cancer patients should be subjected to intensified postoperative pulmonary care.</p></div

    Just give the contrast? Appraisal of guidelines on intravenous iodinated contrast media use in patients with kidney disease

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    Abstract Objective To appraise the quality of guidelines on intravenous iodinated contrast media (ICM) use in patients with kidney disease, and to compare the recommendations among them. Methods We searched four literature databases, eight guideline libraries, and ten homepages of radiological societies to identify English and Chinese guidelines on intravenous ICM use in patients with kidney disease published between January 2018 and June 2023. The quality of the guidelines was assessed with the Scientific, Transparent, and Applicable Rankings (STAR) tool. Results Ten guidelines were included, with a median STAR score of 46.0 (range 28.5–61.5). The guidelines performed well in “Recommendations” domain (31/40, 78%), while poor in “Registry” (0/20, 0%) and “Protocol” domains (0/20, 0%). Nine guidelines recommended estimated glomerular filtration rate (eGFR) < 30 mL/min/1.73 m2 as the cutoff for referring patients to discuss the risk-benefit balance of ICM administration. Three guidelines further suggested that patients with an eGFR < 45 mL/min/1.73 m2 and high-risk factors also need referring. Variable recommendations were seen in the acceptable time interval between renal function test and ICM administration, and that between scan and repeated scan. Nine guidelines recommended to use iso-osmolar or low-osmolar ICM, while no consensus has been reached for the dosing of ICM. Nine guidelines supported hydration after ICM use, but their protocols varied. Drugs or blood purification therapy were not recommended as preventative means. Conclusion Guidelines on intravenous ICM use in patients with kidney disease have heterogeneous quality. The scientific societies may consider joint statements on controversial recommendations for variable timing and protocols. Critical relevance statement The heterogeneous quality of guidelines, and their controversial recommendations, leave gaps in workflow timing, dosing, and post-administration hydration protocols of contrast-enhanced CT scans for patients with kidney diseases, calling for more evidence to establish a safer and more practicable workflow. Key points • Guidelines concerning iodinated contrast media use in kidney disease patients vary. • Controversy remains in workflow timing, contrast dosing, and post-administration hydration protocols. • Investigations are encouraged to establish a safer iodinated contrast media use workflow. Graphical Abstrac
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