Simulation Analysis of Concrete Pumping Based on Smooth Particle Hydrodynamics and Discrete Elements Method Coupling

With an increase of suction efficiency of fresh concrete pumping in confined spaces, the laminar flow state will be damaged by the return flow caused by distribution value direction changes and concrete gravity. This is a fact, but one which is rarely studied. In this work, the flow state, flow velocity, and suction efficiency of fresh concrete pumping are simulated using the coupled smooth particle hydrodynamics and Discrete Elements Method (SPH-DEM). The rheological parameters and Herschel-Bulkley-Papanastasiou (HBP) rheological model are adopted to simulate fresh concrete in the numerical simulation model. The study reveals that the error between the slump experimental result and that obtained by the HBP model is negligible. A model is therefore established for numerical simulations of the suction efficiency of fresh concrete pumping. An experimental concrete pumping platform is built, and the pressure and efficiency data during pumping are collected. A comparison of the numerical simulation with experimental results shows that the error is less than 10%.     

基于机器学习预测模型探究薄型子宫内膜患者接受IVF/ICSI-ET治疗的早期流产风险因素

目的：基于多种机器学习方法,探讨薄子宫内膜患者在新鲜胚胎移植中发生早期流产的影响因素,并建立预测模型,为预防薄子宫内膜患者在进行新鲜胚胎移植中发生早期流产提供合理的指导思路。方法：纳入了首次进行新鲜胚胎移植的薄子宫内膜患者1153例,通过LASSO回归和随机森林递归特征消除（recursive feature elimination,RFE）筛选特征,建立6种机器学习模型,通过交叉验证、准确度、敏感性、召回率、f1值、ROC曲线下面积及校准曲线比较不同模型的性能。SHAP图用于解释影响早期流产的因素。结果：通过LASSO回归和随机森林RFE筛选出29个特征变量纳入六种机器学习模型,其中多层感知机模型对早期流产的区分度最佳,ROC曲线下面积为0.803(95%CI=0.772～0.834)。随机森林、XGBoost和AdaBoost模型的ROC曲线下面积都高于0.7。结论：开发了薄子宫内膜患者在新鲜胚胎移植中是否发生早期流产的机器学习预测模型,各种评价指标的验证表明该模型的性能良好,有助于临床医生对该人群患者的早期诊断,为未来改善早期流产高危患者的妊娠结局提供指导思路。     

基于化学模式识别结合灰色关联度法的鲜地黄药材质量评价

目的：构建基于化学模式识别和灰色关联度法的鲜地黄药材多指标综合评价模型,为鲜地黄药材整体质量评价提供参考。方法：收集不同产地的32批鲜地黄药材样品,测定各批样品中总灰分,酸不溶性灰分,浸出物,梓醇、地黄苷D、铅、镉、砷、汞、铜含量与指纹图谱,采用聚类分析（HCA）、主成分分析（PCA）、正交偏最小二乘法-判别分析和灰色关联度法对各指标数据进行分析。结果：HCA和PCA均可将32批鲜地黄药材分为4类,但无明显产地聚集现象;指纹图谱中峰1～3、9、10的峰面积及总灰分、浸出物、梓醇含量是体现各产地鲜地黄药材质量差异的主要指标;32批鲜地黄药材灰色关联度为0.036～0.042,灰色关联度差异为0～13.89%,综合质量差异不大。结论：化学模式识别结合灰色关联度法构建的多指标综合评价模型分析结果客观、科学、准确,可用于鲜地黄药材质量的综合评价。     

Use of convalescent plasma for managing severe COVID‐19 infection in 2‐month‐old infant

A 58‐day‐old female infant reported with complaints of fever, difficult breathing, loose stool, vomiting and refusal to feed for 4 days. Laboratory work showed anaemia, leucocytosis with elevated neutrophils and thrombocytopenia along with high C‐reactive protein and D‐dimer with bilateral patchy infiltrate on X‐ray and positivity for COVID‐19. Her blood culture was also positive for Gram‐negative bacilli (acinetobacter lwoffii). Along with antibiotics, she was given 50 ml convalescent plasma. She was off oxygen within 2 days and showed improvement in lung lesions, and RT‐PCR was negative by day 7 and discharged by day 10 of transfusion.     

白毛夏枯草鲜汁治疗烫伤的实验研究

目的　观察白毛夏枯草鲜汁对大鼠实验性烫伤模型的治疗作用。方法　SD雄性大鼠背部脱毛后浸入 85℃恒温水浴中15s,使之造成深Ⅱ度烫伤 ,烫伤部位外涂不同浓度的白毛夏枯草鲜汁 ,同时设烫伤宁阳性对照 ,每隔 5d用硫酸纸描绘烫伤面积 ,以硫酸纸重量为指标比较各组烫伤面积大小以及各时段的愈合情况 ,连续 2 5d。结果　从d10开始 ,白毛夏枯草大、中剂量组的皮肤烫伤面积的图纸重量明显轻于模型对照组 (P <0 .0 5 ) ;病理切片结果显示白毛夏枯草各剂量组愈合程度明显好于模型对照组。结论　白毛夏枯草鲜汁对大鼠实验性烫伤模型有显著的治疗作用     

北青龙衣中胡桃苷B的分离及含量测定方法的建立

目的 从北青龙衣醇提取物中分离胡桃苷B并建立了含量测定的方法。方法 利用大孔树脂柱色谱、硅胶柱色谱和反相硅胶柱色谱进行分离纯化,得到胡桃苷B,通过高效液相色谱仪建立了含量测定的方法。结果 经核磁共振谱鉴定胡桃苷B为(4S)-4,5-二羟基-α-四氢萘酮-4-O-β-D-吡喃葡糖苷,高效液相色谱洗脱条件为乙腈-水-磷酸（10∶90∶0.2）。结论 该方法简便可行、重复性好,胡桃苷B可作为北青龙衣的指标成分建立质量控制的方法。     

Nationwide survey of severe postpartum hemorrhage in Japan: an exploratory study using the national database of health insurance claims

Aim: The aim of this study was to investigate epidemiological and clinical aspects of severe postpartum hemorrhage (PPH) in Japan.

Methods: We used national health insurance claims from 2011 to 2014 provided by the Ministry of Health, Labour and Welfare. The data included randomly selected claims that covered 10% of all inpatients in October, a so-called sampling dataset (covering 1/120 inpatients per year). We extracted claims for transfused blood, and further narrowed down the claims by names of diseases linked to PPH. As most referral obstetric facilities have adopted the diagnosis procedure combination (DPC)-based payment system while small-scale obstetric facilities have not (non-DPC facilities), the claims were also analyzed separately for DPC and non-DPC facilities. We assessed the incidence and causes of PPH, transfusion volume of red blood cells (RBC) and fresh frozen plasma (FFP), and surgical hemostatic management.

Results: The number of PPH cases that required blood transfusion in the sampling dataset was 29, 29, 32, and 36 in 2011, 2012, 2013, and 2014, respectively. The leading cause of PPH was uterine atony followed by placental abruption. Although no specific trends were observed for the volume of transfused RBC (1467?±?234?ml in 2014), there was a steady increase in the rate of FFP utilization in non-DPC facilities from 37% to 79% over the 4-year sampling period. Intrauterine balloon tamponade emerged in 2014.

Conclusion: This nationwide survey indicates that the annual incidence of severe PPH is increasing. Furthermore, FFP has become more prevalent in small-scale obstetric facilities.     

A prospective assessment of the medic autologous blood transfusion skills for field transfusion preparation

Background

Data demonstrate the benefit of blood product administration near point-of-injury (POI). Fresh whole blood transfusion from a pre-screened donor provides a source of blood at the POI when resources are constrained. We captured transfusion skills data for medics performing autologous blood transfusion training.

Methods

We conducted a prospective, observational study of medics with varying levels of experience. Inexperienced medics were those with minimal or no reported experience learning the autologous transfusion procedures, versus reported experience among special operations medics. When available, medics were debriefed after the procedure for qualitative feedback. We followed them for up to 7 days for adverse events.

Results

The median number of attempts for inexperienced and experienced medics was 1 versus 1 (interquartile range 1–1 for both, p = .260). The inexperienced medics had a slower median time to needle venipuncture access for the donation of 7.3 versus 1.5 min, needle removal after clamping time of 0.3 versus 0.2 min, time to bag preparation of 1.9 versus 1.0 min, time to IV access for reinfusion of 6.0 versus 3.0 min, time to transfusion completion of 17.3 versus 11.0 min, and time to IV removal of 0.9 versus 0.3 min (all p < .05). We noted one administrative safety event in which an allogeneic transfusion occurred. No major adverse events occurred. Qualitative data saturated around the need for quarterly training.

Conclusions

Inexperienced medics have longer procedure times when training autologous whole blood transfusion skills. This data will help establish training measures of performance for skills optimization when learning this procedure.     

Comprehensive quality initiative leads to immediate postoperative extubation following liver transplant

BackgroundImmediate postoperative extubation (IPE) can reduce perioperative complications and length of stay (LOS), however it is performed variably after liver transplant across institutions and has historically excluded high-risk recipients from consideration. In late 2012, we planned and implemented a single academic institution structured quality improvement (QI) initiative to standardize perioperative care of liver transplant recipients without exceptions. We hypothesized that such an approach would lead to a sustained increase in IPE after primary (PAC) and delayed abdominal closure (DAC).MethodsWe retrospectively studied 591 patients from 2013 to 2018 who underwent liver transplant after initiative implementation. We evaluated trends in incidence of IPE versus delayed extubation (DE), and reintubation, LOS, and mortality.ResultsOverall, 476/591 (80.5%) recipients underwent PAC (278 IPE, 198 DE) and 115/591 (19.5%) experienced DAC (39 IPE, 76 DE). When comparing data from 2013 to data from 2018, the incidence of IPE increased from 9/67 (13.4%) to 78/90 (86.7%) after PAC and from 1/12 (8.3%) to 16/23 (69.6%) after DAC. For the same years, the incidence of IPE after PAC for recipients with MELD scores ≥30 increased from 0/19 (0%) to 12/17 (70.6%), for recipients who underwent simultaneous liver-kidney transplant increased from 1/8 (12.5%) to 4/5 (80.0%), and for recipients who received massive transfusion (>10 units of packed red blood cells) increased from 0/17 (0%) to 10/13 (76.9%). Reintubation for respiratory considerations <48 h after IPE occurred in 3/278 (1.1%) after PAC and 1/39 (2.6%) after DAC. IPE was associated with decreased intensive care unit (HR of discharge: 1.92; 95% CI: 1.58, 2.33; P < 0.001) and hospital LOS (HR of discharge: 1.45; 95% CI: 1.20, 1.76; P < 0.001) but demonstrated no association with mortality.ConclusionA structured QI initiative led to sustained high rates of IPE and reduced LOS in all liver transplant recipients, including those classified as high risk.