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161.
The medium carbon-medium alloy steel was developed for the manufacture of large ball mill liners and sports equipment. In this study, the continuous cooling transformation curve of a novel type of medium carbon-medium alloy steel was measured with a thermal simulation machine; based on this curve, the hardening and tempering processes were optimized. The steel was then complex modified with alkaline earth and rare earth alloys. The mechanical properties of the treated steel were tested. The microstructure of the steel was analyzed by metallographic microscopy, X-ray diffraction, scanning electron microscopy and transmission electron microscopy, and the wear surface of the steel was analyzed by a three-dimensional morphometer. After high-temperature tempering, the microstructure transformed into tempered sorbite, which possesses good mechanical properties and can adapt to working conditions that require high strength and toughness. Rare earth or alkaline earth modification of the medium carbon-medium alloy steel promoted microstructural uniformity and grain refinement and improved the mechanical and anti-wear properties. 相似文献
162.
Shuai Peng Zhenpeng Yu Qi Zhao Xiaoqing Du Xinghua Xie Bo Chen Yongping Zhang 《Materials》2022,15(13)
To investigate the dynamic compressive properties of concrete after high temperature and rapid cooling, an experimental study was carried out by considering five temperatures and four strain rates. The coupling effect of high temperature and strain rate on concrete damage morphology and mechanical parameters was comparatively analyzed. The main conclusions are as follows: the compressive damage morphology of concrete is affected by strain rate development trends of significant variability under different temperature conditions. As the strain rate increases, the compressive stress and elastic modulus of concrete are gradually increased. As the temperature increases, the increase in compressive stress is gradually reduced by the strain rate. For the temperatures of 20 °C and 800 °C, the increase in compressive stress by the strain rate is 38.69% and 7.78%, respectively. Meanwhile, SEM and CT scanning technology were applied to examine the mechanism of the effect of high temperature and strain rate on the mechanical properties of concrete from the microscopic perspective, and the corresponding constitutive model was proposed. 相似文献
163.
Min Li Tianjiao Zhang Jing Zhu Yuebo Li Wenying Chen Yanhu Xie Wei Zhang Rongzhu Chen Wei Wei Guihong Wang Jiwei Qin Weidong Zhao Dabao Wu Zhen Shen Bjrn Nashan Ying Zhou 《Oncology Letters》2022,23(5)
The present study aimed to evaluate the postoperative complications and the impact of an enhanced recovery programme in patients who underwent primary surgery (including extensive upper abdominal surgery) for epithelial ovarian carcinoma (EOC). All patients with stage I–IV ovarian carcinoma who underwent primary surgery were identified, and postoperative complications were evaluated and graded according to the Clavien-Dindo classification. Of 161 patients, 46 (28.57%) underwent surgical staging, 27 (16.77%) standard cytoreduction, 12 (7.45%) en bloc debulking and 76 (47.20%) extraradical debulking. A total of 157 patients (97.52%) achieved optimal tumor reduction (<1 cm). The mean postoperative hospitalization time was 17.33±11.29 days after completion of the initial postoperative chemotherapy (IPC), and the IPC interval was 16.22±10.09 days. A total of 13 patients (8.07%) had grade 3 complications (9 with wound dehiscence, 3 with digestive tract leakage and 1 with a bladder fistula). A total of 2 patients (1.24%) had grade 4–5 complications [1 patient with severe pneumonia returned to the intensive care unit (ICU) for tracheotomy and respiration rehabilitation; the other patient died of septicemia on day 19]. The multivariate analysis of the preoperative factors revealed that a human epididymis protein 4 (HE4) level of ≥717 pM (P=0.015) and Federation International of Gynecology and Obstetrics (FIGO) stage IV (P=0.004; compared with stage IIIC) were associated with grade 3–5 complications. The bootstrap analysis revealed that a cancer antigen 125 (CA125) level of ≥1,012 U/ml (P=0.034), a HE4 level of ≥717 pM (P=0.007) and FIGO stage IV (P=0.002; compared with stage IIIC) were significantly associated with grade 3–5 complications. Meanwhile, the multivariate analysis of the postoperative factors did not reveal any risk factors associated with grade 3–5 complications; the bootstrap analysis revealed that only transfer to the ICU after surgery (P=0.026) was significantly associated with grade 3–5 complications. In conclusion, the study found that application of enhanced recovery after surgery protocols is feasible in patients with EOC, especially in those undergoing advanced extensive upper abdominal surgery, and CA125, HE4 and FIGO stage IV were related with the occurrence of adverse perioperative outcomes. 相似文献
164.
背景 严重精神障碍患者危险行为发生率较一般人群更高,我国对社区严重精神障碍患者危险行为发生风险的预测研究尚不多见,尤其缺乏除传统预测方法之外的数据挖掘技术预测模型的研究和比较。目的 采用Logistic回归分析及分类决策树构建社区严重精神障碍患者危险行为发生风险的预测模型,检验分类决策树模型是否优于Logistic回归模型。方法 于2023年12月,选取2013年—2022年随访记录完整的11 484名社区严重精神障碍在管患者,按8∶2随机分为训练集(n=9 186)与测试集(n=2 298)。在训练集中,分别使用Logistic回归分析和分类决策树建立预测模型,在测试集评价模型的区分度和校准度。结果 1 115例(9.71%)严重精神障碍患者在随访期间出现危险行为。Logistic回归分析结果显示,城市户籍、贫困、有监护人、精神残疾、危险行为史阳性、自知力不全、自知力缺失、有阳性症状是患者发生危险行为的危险因素(OR=1.778、1.459、2.719、1.483、3.890、1.423、2.528、2.124,P均<0.01);年龄≥60岁、受过教育、医嘱无需用药以及社会功... 相似文献
165.
Yuan Hong Ziyi Zhou Nan Zhang Qiangqiang He Zhangyou Guo Lishun Liu Yun Song Ping Chen Yaping Wei Qiuyue Xu Ya Li Binyan Wang Xianhui Qin Xiping Xu Yong Duan 《Journal of clinical hypertension (Greenwich, Conn.)》2022,24(7):945
We aimed to evaluate the prospective association of vitamin B5 with all‐cause mortality and explore its potential modifiers in Chinese adults with hypertension. A nested, case‐control study was conducted in the China Stroke Primary Prevention Trial, including 505 deaths of all causes and 505 matched controls. The median follow‐up duration was 4.5 years. The primary outcome measure in this investigation was all‐cause mortality, which encompassed deaths for any reason. The mean plasma vitamin B5 concentration for cases (43.7 ng/mL) was higher than that in controls (40.9 ng/mL) (p = .001). When vitamin B5 was further assessed as quintiles, compared with the reference group (Q1: < 33.0 ng/mL), the risk of all‐cause mortality increased by 29% (OR = 1.29, 95% CI: 0.83‐2.01) in Q2, 22% (OR = 1.22, 95% CI: 0.77‐1.94) in Q3, 62% (OR = 1.62, 95% CI: 1.00‐2.62) in Q4, and 77% (OR = 1.77, 95% CI: 1.06‐2.95) in Q5. The trend test was significant (p = .022). When Q4‐Q5 were combined, a significant 41% increment (OR = 1.41, 95% CI: 1.03‐1.95) in all‐cause death risk was found compared with Q1‐Q3. The adverse effects were more pronounced in those with normal folate levels (p‐interaction = .019) and older people (p‐interaction = .037). This study suggests that higher baseline levels of plasma vitamin B5 are a risk factor for all‐cause mortality among Chinese patients with hypertension, especially among older adults and those with adequate folate levels. The findings, if confirmed, may inform novel clinical and nutritional guidelines and interventions to optimize vitamin B5 levels. 相似文献
166.
167.
168.
Jinlong Wang Mengjuan Shi Lili Huang Qing Li Shanshan Meng Jingyuan Xu Ming Xue Jianfeng Xie Songqiao Liu Yingzi Huang 《Renal failure》2022,44(1):1207
PurposeTerlipressin improves renal function in patients with septic shock. However, the mechanism remains unclear. Here, we aimed to evaluate the effects of terlipressin on renal perfusion in patients with septic shock.Materials and MethodsThis pilot study enrolled patients with septic shock in the intensive care unit of the tertiary hospital from September 2019 to May 2020. We randomly assigned patients to terlipressin and usual care groups using a 1:1 ratio. Terlipressin was intravenously pumped at a rate of 1.3 μg/kg/hour for 24 h. We monitored renal perfusion using renal contrast-enhanced ultrasound (CEUS). The primary outcome was peak sonographic signal intensity (a renal perfusion parameter monitored by CEUS) at 24 h after enrollment.Results22 patients were enrolled in this study with 10 in the terlipressin group and 12 in the usual care group. The baseline characteristics of patients between the two groups were comparable. The peak sonographic signal intensity at 24 h after enrollment in the terlipressin group (60.5 ± 8.6 dB) was significantly higher than that in the usual care group (52.4 ± 7.0 dB; mean difference, 7.1 dB; 95% CI, 0.4–13.9; adjusted p = .04). Patients in the terlipressin group had a lower time to peak, heart rates, norepinephrine dose, and a higher stroke volume at 24 h after enrollment. No significant difference in the urine output within 24 h and incidence of acute kidney injury within 28 days was found between the two groups.ConclusionsTerlipressin improves renal perfusion, increases stroke volume, and decreases norepinephrine dose and heart rates in patients with septic shock. 相似文献
169.
BackgroundOn May 18, 2020, the New York State Department of Health implemented a statewide flavor ban to prohibit the sales of all flavored vapor products, except for tobacco or any other authorized flavor.ObjectiveThis study aims to investigate the discussion changes in e-cigarette–related tweets over time with the implementation of the New York State flavor ban.MethodsThrough the Twitter streaming application programming interface, 59,883 e-cigarette–related tweets were collected within the New York State from February 6, 2020, to May 17, 2020 (period 1, before the implementation of the flavor ban), May 18, 2020-June 30, 2020 (period 2, between the implementation of the flavor ban and the online sales ban), July 1, 2020-September 15, 2020 (period 3, the short term after the online sales ban), and September 16, 2020-November 30, 2020 (period 4, the long term after the online sales ban). Sentiment analysis and topic modeling were conducted to investigate the changes in public attitudes and discussions in e-cigarette–related tweets. The popularity of different e-cigarette flavor categories was compared before and after the implementation of the New York State flavor ban.ResultsOur results showed that the proportion of e-cigarette–related tweets with negative sentiment significantly decreased (4305/13,246, 32.5% vs 3855/14,455, 26.67%, P<.001), and tweets with positive sentiment significantly increased (5246/13,246, 39.6% vs 7038/14,455, 48.69%, P<.001) in period 4 compared to period 3. “Teens and nicotine products” was the most frequently discussed e-cigarette–related topic in the negative tweets. In contrast, “nicotine products and quitting” was more prevalent in positive tweets. The proportion of tweets mentioning mint and menthol flavors significantly increased right after the flavor ban and decreased to lower levels over time. The proportions of fruit and sweet flavors were most frequently mentioned in period 1, decreased in period 2, and dominated again in period 4.ConclusionsThe proportion of e-cigarette–related tweets with different attitudes and frequently discussed flavor categories changed over time after the implementation of the New York State ban of flavored vaping products. This change indicated a potential impact of the flavor ban on public discussions of flavored e-cigarettes. 相似文献
170.
Zongyan Xie ChenFei Li Yaxin An Dong Zhao Xuhong Wang 《The Journal of international medical research》2022,50(7)
Thyroid hormone resistance syndrome (THRS) is a rare disease characterized by reduced sensitivity to thyroid hormones. Mutations in the thyroid hormone receptor beta (THRB) gene are considered as contributing to the pathogenesis. This report describes a Chinese pedigree with THRS and Hashimoto’s thyroiditis (HT) due to novel point mutation in the 11th exon of the THRB gene (c. 1378 G > A). The proband complained of goitre with increased thyroid hormone and normal thyroid stimulating hormone levels. Gene sequencing was performed to confirm the diagnosis. HT was also diagnosed based on positive thyroid autoantibodies and diffuse, grid-like changes in the thyroid on ultrasound examination. Additionally, a comprehensive examination of the proband’s pedigree was conducted. The patient’s father exhibited the same gene mutation site and was diagnosed with THRS and HT. No mutation site was detected in three patients with HT only and three healthy volunteers. Thus, gene sequencing should be considered the gold standard for diagnosing THRS. Furthermore, treatment should be individualized to control the patient’s symptoms rather than normalizing thyroid hormone levels. Further studies that determine the relationship between THRS and TH are warranted. 相似文献