Experiment and Theoretical Investigation on Fatigue Life Prediction of Fracturing Pumpheads Based on a Novel Stress-Field Intensity Approach

Fracturing pumpheads are typical pressure vessels that experience frequent fatigue failure under the effect of notches in their cross-bore. To enhance the fatigue life of fracturing pumpheads, the study of the notch effect is indispensable and important to establish a reliable mathematical model to predict their fatigue life. In the present paper, two novel fatigue life prediction models are proposed for notched specimens. In these models, two new geometric fatigue failure regions are defined to improve the weight function. Finally, the elaborated novel stress-field intensity approach was applied to three different types of notched specimens. Experiment results indicate that the new SFI approach achieves 47.82%, 39.48%, and 31.85% higher prediction accuracy than the traditional SFI approach, respectively. It was found that the modified SFI approach provided better predictions than the traditional SFI approach and the TCD method. The II-th novel SFI approach had the highest accuracy, and the I-th novel SFI approach was more suitable for sharply notched specimens.     

Association Between Nap and Reported Cognitive Function and Role of Sleep Debt: A Population-Based Study

Background and PurposeThe relationship between napping and cognition remains controversial. This study aimed to investigate the association between napping and cognition according to sleep debt in the Korean adult population.MethodsA population-based nationwide cross-sectional survey was conducted in 2018. A two-stage stratified random sample of Koreans aged ≥19 years was selected and evaluated using questionnaires by trained interviewers. Cognitive function was assessed using the Mail-In Cognitive Function Screening Instrument (MCFSI). Sleep habits on weekdays and weekends, napping, and subjective sleep requirements were assessed using the questionnaires. Accumulated sleep debt was calculated by subtracting the weekly average sleep duration from subjective sleep requirements. Sleep quality, daytime sleepiness, insomnia, depression, demographics, and comorbidities were assessed. Participants were grouped into those with sleep debt ≤60 min and those with sleep debt >60 min. Multiple linear regression was used to estimate the independent association between the factors and cognition.ResultsIn total, 2,501 participants were included in the analysis. Naps were reported in 726 (29.0%) participants (nappers). The mean MCFSI score was higher in nappers (3.4±3.6) than in non-nappers (2.3±3.0) (p<0.001). Multiple linear regression controlling for age, alcohol, smoking, depression, insomnia, daytime sleepiness, sleep quality, and education revealed that 30 to 60 min of napping was associated with worse cognitive function in participants with sleep debts ≤60 min, while >60 min of napping was associated with better cognitive function in participants with sleep debts >60 min.ConclusionsIn general, naps are associated with worse cognitive function in the Korean adult population. However, for those with sleep debt of >60 min, naps for >60 min were associated with better cognitive function.     

联合检测对地中海贫血实验诊断的应用价值

目的 评价红细胞平均体积（MCV）、红细胞脆性试验和血红蛋白（Hb）电泳在地中海贫血诊断及其产前筛查中的价值。方法 选择2004年至2005年间在我院进行系统产前检查的已被基因诊断证实的210例地中海贫血夫妇的筛查实验结果进行回顾性分析。结果 MCV、红细胞脆性试验及Hb电泳单项检测在地中海贫血产前筛查的灵敏度和特异度分别为97．6％、89．5％、90．0％及76．0％、89．3％、97．3％;MCV与Hb电泳、红细胞脆性试验与Hb电泳2项平行联合检测的灵敏度及特异度分别为100．0％、86．7％及99．0％、89．3％,系列联合检测的灵敏度及特异度分别为89．0％、99．7％及87．1％、100．0％。MCV、红细胞脆性试验及Hb电泳3项平行联合检测的灵敏度及特异度分别为100．0％、79．7％;3项系列联合检测灵敏度及特异度为86．7％、100．0％。经u检验,平行联合检测的灵敏度与各单项检测灵敏度之间、系列联合检测的特异度与各单项检测特异度之间差异有统计学意义（P〈0．05）。结论 MCV、红细胞脆性试验及Hb电泳3项联合检测是地中海贫血诊断及其产前筛查中最理想的试验方法。     

选择性头部降温对胎羊缺血性脑损伤纹状体神经元凋亡和星形胶质细胞增殖的影响

目的研究选择性头部降温对缺血性脑损伤胎羊纹状体神经元凋亡和星形胶质细胞增殖的影响。方法胎羊于妊娠117~124d时通过双侧颈动脉阻塞30min造成双侧脑缺血损伤,损伤后将胎羊随机分为:损伤组(n=10)、2h低温组(损伤后2h开始亚低温治疗,n=7)和6h低温组(损伤后6h开始亚低温治疗,n=8),另设正常对照组(n=5)。通过冷循环水进行选择性头部降温,取脑组织用免疫组化法检测胎羊纹状体caspase-3(半胱天冬氨酸酶-3),GFAP(胶质纤维酸性蛋白)和PCNA(增殖细胞核抗原)的表达。结果①纹状体神经元凋亡:正常对照组中,caspase-3表达极少(11.00±13.77),损伤组caspase-3免疫阳性细胞为177.70±48.69,明显增加(P=0.000),损伤后2h治疗组(54.14±39.44,P=0.000)和损伤后6h治疗组(122.43±52.36,P=0.017)均能减少caspase-3免疫阳性细胞。②纹状体星形胶质细胞增殖:与正常对照组(163.40±21.98)相比,缺血性脑损伤组的GFAP免疫阳性细胞明显增多(433.25±66.69,P=0.000),损伤后2h开始亚低温治疗(219.50±35.31,P=0.000)和损伤后6h开始亚低温治疗(272.50±86.20,P=0.000)均能减少GFAP免疫阳性细胞。③纹状体PCNA阳性细胞的表达:在正常对照组中,PCNA免疫阳性细胞较少,为153.40±12.46,缺血性脑损伤组的PCNA免疫阳性细胞明显增多(353.70±45.60,P=0.000),损伤后2h开始亚低温治疗(187.14±26.26,P=0.000)和损伤后6h开始亚低温治疗(230.25±67.46,P=0.000)均能减少PCNA免疫阳性细胞。结论亚低温可以抑制纹状体神经元的凋亡和星形胶质细胞的增殖,该作用可能为选择性头部降温的脑保护作用机制之一。     

Association between plasma Vitamin B5 levels and all‐cause mortality: A nested case‐control study

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.     

Clinical course and outcomes of COVID-19 patients with chronic obstructive pulmonary disease: A retrospective observational study in Wuhan,China

Information about coronavirus disease 2019 (COVID-19) patients with pre-existing chronic obstructive pulmonary disease (COPD) is still lacking. The aim of this study is to describe the clinical course and the outcome of COVID-19 patients with comorbid COPD.This retrospective study was performed at Wuhan Huoshenshan Hospital in China. Patients with a clear diagnosis of COVID-19 who had comorbid COPD (N = 78) were identified. COVID-19 patients without COPD were randomly selected and matched by age and sex to those with COPD. Clinical data were analyzed and compared between the two groups. The composite outcome was the onset of intensive care unit admission, use of mechanical ventilation, or death during hospitalization. Multivariable Cox regression analyses controlling for comorbidities were performed to explore the relationship between comorbid COPD and clinical outcome of COVID-19.Compared to age- and sex-matched COVID-19 patients without pre-existing COPD, patients with pre-existing COPD were more likely to present with dyspnea, necessitate expectorants, sedatives, and mechanical ventilation, suggesting the existence of acute exacerbations of COPD (AECOPD). Greater proportions of patients with COPD developed respiratory failure and yielded poor clinical outcomes. However, laboratory tests did not show severer infection, over-activated inflammatory responses, and multi-organ injury in patients with COPD. Kaplan–Meier analyses showed patients with COPD exhibited longer viral clearance time in the respiratory tract. Multifactor regression analysis showed COPD was independently correlated with poor clinical outcomes.COVID-19 patients with pre-existing COPD are more vulnerable to AECOPD and subsequent respiratory failure, which is the main culprit for unfavorable clinical outcomes. However, COPD pathophysiology itself is not associated with over-activated inflammation status seen in severe COVID-19.     

Predicting the depressive status using empirical dietary inflammatory index in patients with antineutrophil cytoplasmic antibody‐associated vasculitis

BackgroundThis study investigated whether the empirical dietary inflammatory index (eDII) score is associated with the inflammatory burden as well as the depressive status in patients with antineutrophil cytoplasmic antibody‐associated vasculitis (AAV).MethodsEighty‐four patients with AAV participated in this study. Birmingham vasculitis activity score (BVAS) and short‐form 36‐item Health Survey mental component summary (SF‐36 MCS) were considered as indices assessing the inflammatory burden and depressive status, respectively. The eDII includes 16 food components and consists of three groups: −9 to −2, the low eDII group; −1 to +1, the moderate eDII group; and +2 to +10, the high eDII group. Furthermore, the lower eDII group includes both the low and moderate eDII groups.ResultsThe median age was 64.5 years (36 men). The eDII scores inversely correlated with SF‐36 MCS (r = −0.298, p = 0.006) but not with BVAS. SF‐36 MCS significantly differ between the lower and higher eDII groups (69.7 vs. 56.7, p = 0.016), but not among the low, moderate and high eDII groups. Additionally, when patients with AAV were divided into two groups according to the upper limit of the lowest tertile of SF‐36 MCS of 55.31, patients in the higher eDII group exhibited a significantly higher risk for the lowest tertile of SF‐36 MCS than those in the lower eDII group (RR 3.000).ConclusionWe demonstrated for the first time that the eDII could predict the depressive status by estimating SF‐36 MCS without utilising K‐CESD‐R ≥ 16 in patients with AAV.     

Development and evaluation of time‐resolved fluorescent immunochromatographic assay for quantitative detection of SARS‐CoV‐2 spike antigen

BackgroundThe spread of COVID‐19 worldwide caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has necessitated efficient, sensitive diagnostic methods to identify infected people. We report on the development of a rapid 15‐minute time‐resolved fluorescent (TRF) lateral flow immunochromatographic assay for the quantitative detection of the SARS‐CoV‐2 spike protein receptor‐binding domain (S1‐RBD).ObjectivesOur objective was to develop an efficient method of detecting SARS‐CoV‐2 within 15 min of sample collection.MethodsWe constructed and evaluated a portable, disposable lateral flow device, which detected the S1‐RBD protein directly in nasopharyngeal swab samples. The device emits a fluorescent signal in the presence of S1‐RBD, which can be captured by an automated TRF instrument.ResultsThe TRF lateral flow assay signal was linear from 0 to 20 ng/ml and demonstrated high accuracy and reproducibility. When evaluated with clinical nasopharyngeal swabs, the assay was performed at >80% sensitivity, >84% specificity, and > 82% accuracy for detection of the S1‐RBD antigen.ConclusionThe new S1‐RBD antigen test is a rapid (15 min), sensitive, and specific assay that requires minimal sample preparation. Critically, the assay correlated closely with PCR‐based methodology in nasopharyngeal swab samples, showing that the detected S1‐RBD antigen levels correlate with SARS‐CoV‐2 virus load. Therefore, the new TRF lateral flow test for S1‐RBD has potential application in point‐of‐care settings.     

Immunogenicity and Reactogenicity of Ad26.COV2.S in Korean Adults: A Prospective Cohort Study

BackgroundAs the coronavirus disease 2019 (COVID-19) pandemic continues, there are concerns regarding waning immunity and the emergence of viral variants. The immunogenicity of Ad26.COV2.S against wild-type (WT) and variants of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) needs to be evaluated.MethodThis prospective cohort study was conducted between June 2021 and January 2022 at two university hospitals in South Korea. Healthy adults who were scheduled to be vaccinated with Ad26.COV2.S were enrolled in this study. The main outcomes included anti-spike (S) IgG antibody and neutralizing antibody responses, S-specific T-cell responses (interferon-γ enzyme-linked immunospot assay), solicited adverse events (AEs), and serious AEs.ResultsFifty participants aged ≥ 19 years were included in the study. Geometric mean titers (GMTs) of anti-S IgG were 0.4 U/mL at baseline, 5.2 ± 3.0 U/mL at 3–4 weeks, 55.7 ± 2.4 U/mL at 5–8 weeks, and 81.3 ± 2.5 U/mL at 10–12 weeks after vaccination. GMTs of 50% neutralizing dilution (ND50) against WT SARS-CoV-2 were 164.6 ± 4.6 at 3-4 weeks, 313.9 ± 3.6 at 5–8 weeks, and 124.4 ± 2.6 at 10–12 weeks after vaccination. As for the S-specific T-cell responses, the median number of spot-forming units/10⁶ peripheral blood mononuclear cell was 25.0 (5.0–29.2) at baseline, 60.0 (23.3–178.3) at 5-8 weeks, and 35.0 (13.3–71.7) at 10–12 weeks after vaccination. Compared to WT SARS-CoV-2, ND50 against Delta and Omicron variants was attenuated by 3.6-fold and 8.2-fold, respectively. The most frequent AE was injection site pain (82%), followed by myalgia (80%), fatigue (70%), and fever (50%). Most AEs were grade 1–2, and resolved within two days.ConclusionSingle-dose Ad26.COV2.S was safe and immunogenic. NAb titer and S-specific T-cell immunity peak at 5–8 weeks and rather decrease at 10–12 weeks after vaccination. Cross-reactive neutralizing activity against the Omicron variant was negligible.     

握球运动配合水胶体敷料透明贴在肺癌经外周中心静脉导管置管化疗患者并发症预防中的应用

目的 探讨握球运动配合水胶体敷料透明贴对降低经外周中心静脉导管（PICC）化疗肺癌患者并发症的作用。方法 选取2019年12月至2021年1月九江市第一人民医院呼吸内科收治的96例PICC置管化疗的肺癌患者作为研究对象,按照随机数字表法将其分为对照组与研究组,每组各48例。对照组患者采用50%的硫酸镁温敷,研究组患者采用水胶体敷料透明贴联合握球运动训练干预。比较两组患者置管3个月内的导管相关并发症发生率和置管前及置管后1、2、3个月置管肢体侧腋静脉最大血液流速（Vmax）、单位时间平均血液流速（TMFV）。结果 研究组患者干预后的静脉炎和静脉血栓发生率低于对照组,差异有统计学意义（P<0.05）。两组患者的渗血和导管异位发生率比较,差异无统计学意义（P>0.05）。两组患者置管前的Vmax、TMFV水平比较,差异无统计学意义（P>0.05）;两组患者置管后1、2、3个月的Vmax、TMFV水平低于置管前,差异有统计学意义（P<0.05）;研究组患者置管后1、2、3个月的Vmax、TMFV水平高于对照组,差异有统计学意义（P<0.05）;且组别、交互中差异有...