Non-invasive assessment for intratumoural distribution of interstitial fluid flow

Interstitial fluid plays a vital role in drug delivery and tumour treatment.However,few non-invasive measurement methods are available for measuring low-velocity biological fluid flow.Therefore,this study aimed to develop a novel technology called interstitial flow velocity-MRI.The interstitial flow velocity-MRI sequence consists of a dual inversion recovery preparation and an improved stimulated echo sequence(ISTE)combined with phase-contrast MRI.A homemade flow phantom was used to assess the feasibility and sensitivity of interstitial flow velocity-MRI.In addition,xenografts of female BALB/c mouse models of 4T1 breast cancer administered losartan(40 mg/kg)or saline(n?6)were subjected to imaging on a 7.0 T scanner to assess the in vivo interstitial fluid flow velocity.The results showed a significant correlation(P<0.001)between the theoretical velocities and velocities measured using the flow phantom.Interstitial flow velocity-MRI could detect a velocity as low as 10.21±2.65 mm/s with a spatial resolution of 0.313 mm.The losartan group had a lower mean interstitial fluid velocity than the control group(85±16 vs 113±24 mm/s).In addition,compared to the saline treatment,losartan treatment reduced the proportion of collagen fibres by 10%and 12%in the Masson and Sirius red staining groups,respectively.Interstitial flow velocity-MRI has the potential to determine interstitial fluid flow velocity non-invasively and exhibits an intuitive velocity map.

MEEMD-DBA-based short term traffic flow prediction

Aiming at the problem that ensemble empirical mode decomposition(EEMD)method can not completely neutralize the added noise in the decomposition process,which leads to poor reconstruction of decomposition results and low accuracy of traffic flow prediction,a traffic flow prediction model based on modified ensemble empirical mode decomposition(MEEMD),double-layer bidirectional long-short term memory(DBiLSTM)and attention mechanism is proposed.Firstly,the intrinsic mode functions(IMFs)and residual components(Res)are obtained by using MEEMD algorithm to decompose the original traffic data and separate the noise in the data.Secondly,the IMFs and Res are put into the DBiLSTM network for training.Finally,the attention mechanism is used to enhance the extraction of data features,then the obtained results are reconstructed and added.The experimental results show that in different scenarios,the MEEMD-DBiLSTM-attention(MEEMD-DBA)model can reduce the data reconstruction error effectively and improve the accuracy of the short-term traffic flow prediction.

Transmural myocardial ischemia due to slow coronary flow

Slow coronary flow phenomenon(SCFP) is an angiographic observation characterized by delayed distal vessel opacifi-cation in the absence of significant epicardial coronary disease. Only limited studies have been focused on the etiologies,clinical manifestations and treatment of this unique angiographic phenomenon. In our case report,we described an 85-year-old man who came with significant ST segment elevation in leads V1-V4 and V3R-V5R without increase in myocardial enzyme. The patient also developed respiratory failure requiring intubation and mechanical ventilation. Coronary angiography revealed only mild atherosclerosis without spasm or thromboembolic occlusion. Slow flow was seen in all coronary arteries,especially in the left anterior descending and right coronary arteries. This case speculated that transmural myocardial ischemia with ST segment elevation might be resulted from slow coronary flow. Transmural myocardial ischemia can occur owing to abnormalities of the coronary microcirculation.

Calculation of the Water Distribution Networks Based on the Theory of Slow Transient Flow

Urban water supply network is a modern urban survival and development of the infrastructure of a city,and its normal running conditions have important significance. The actual hydraulic process in the variableload water distribution networks can be treated as the slow transient flow which belongs to the unsteady flow. This paper analyzes the multi-loops network slow transient model based on graph theory,and the link flow matrix is treated as the variables of the discrete solution model to simulate the process of the slow transient flow in the network. With the simulation of hydraulic regime in an actual pipe network,the changing laws of the flow in the pipes,nodal hydraulic heads and other hydraulic factors with the passage of time are obtained. Since the transient processes offer much more information than a steady process,the slow transient theory is not only practical on analyzing the hydraulic condition of the network,but also on identifying hydraulic resistance coefficients of pipes and detecting the leakage in networks.

Plastic-Flow Waves (“Slow-Waves") and Seismic Activity in Central-Eastern Asia

The results inferred from experiments with analogue models carried out previously have shown that two types of plastic-flow waves, “fast-waves" and “slow-waves", are induced in the lower lithosphere (including the lower crust and lithospheric mantle) under driving at plate boundaries and both of them are viscous gravity waves formed by the superposition of major and subsidiary waves. The major waves are similar to solitary waves and the subsidiary waves are traveling waves. The plastic-flow waves in the lower lithosphere control seismic activities in the overlying seismogenic layer and result in the distribution of earthquakes along the wave-crest belts. “Fast-waves" propagated with velocities of orders of magnitude of 100～102km/a have been verified by wave-controlled earthquake migration, showing the “decade waves" and “century waves" with the average periods of 10.8 and 93.4 a, respectively, which originate from the Himalayan driving boundary. According to the recognition of the patterns of the belt-like distribution of strong earthquakes with M S≥7.0, it is indicated further in this paper that the “slow-waves" with velocities of orders of magnitude of 100～101 m/a also originated under compression from the Himalayan driving boundary. Strong earthquakes with M S≥7.0 are controlled mainly by subsidiary waves, because the major waves with a duration of up to 106 a for each disturbance cannot result in the accumulation of enough energy for strong earthquakes due to the relaxation of the upper crust. The subsidiary waves propagate with an average wave length of 445 km, velocities of 0.81～2.80 m/a and periods of 0.16～0.55 Ma. The wave-generating time at the Himalayan driving boundary is about 1.34～4.59 Ma before present for the “slow-waves", corresponding to the stage from the Mid Pliocene to the Mid Early-Pleistocene and being identical with one of the major tectonic episodes of the Himalayan tectonic movement. It is shown from the recognition of the wave-controlled belts of strong earthquakes that two optimal patterns of wave-crest belts originated simultaneously from the eastern and western segments of the Himalayan arc, respectively. The overlap of wave-crest belts of these two systems is responsible for the relative concentration of energy and forms the seismic-energy-background zones for strong earthquakes with M S≥7.0.

Effect of nicorandil on the coronary artery microcirculation and hemodynamics in patients with coronary slow flow

Objective:To explore the effect of nicorandil on the coronary artery microcirculation and hemodynamics in patients with coronary slow flow (CSF).Methods: A total of 86 patients with CSF who were admitted in our hospital were included in the study and randomized into the treatment group and the control group with 43 cases in each group. The patients in the control group were given aspirin, HMG-CoA reductase inhibitor, and ACEI. On this basis, the patients in the treatment group were given nicorandil. The patients in the two groups were continuously treated for 6 months. The coronary artery microcirculation and hemodynamic indicators before and after treatment in the two groups were detected and compared.Results:TAT, ET-1, and hs-CRP levels, LAD, LCX, RCA, TIMI average blood flow frame count value, and IMR after treatment in the two groups were significantly reduced when compared with before treatment (P<0.05). The above indicators after treatment in the treatment group were significantly lower than those in the control group (P<0.05). FMD after treatment in the two groups was significantly elevated when compared with before treatment (P<0.05). FMD after treatment in the treatment group was significantly higher than that in the control group (P<0.05). Conclusions: Nicorandil in the treatment of CSF can effectively improve the coronary artery microcirculation and hemodynamics, with a significant efficacy.

Short-Term Traffic Flow Prediction Based on Road Network Topology

Accurate short-term traffic flow prediction plays a crucial role in intelligent transportation system (ITS), because it can assist both traffic authorities and individual travelers make better decisions. Previous researches mostly focus on shallow traffic prediction models, which performances were unsatisfying since short-term traffic flow exhibits the characteristics of high nonlinearity, complexity and chaos. Taking the spatial and temporal correlations into consideration, a new traffic flow prediction method is proposed with the basis on the road network topology and gated recurrent unit (GRU). This method can help researchers without professional traffic knowledge extracting generic traffic flow features effectively and efficiently. Experiments are conducted by using real traffic flow data collected from the Caltrans Performance Measurement System (PEMS) database in San Diego and Oakland from June 15, 2017 to September 27, 2017. The results demonstrate that our method outperforms other traditional approaches in terms of mean absolute percentage error (MAPE), symmetric mean absolute percentage error (SMAPE) and root mean square error (RMSE).

Multi-scale Chaotic Analysis of the Characteristics of Gas-Liquid Two-phase Flow Patterns

Using the high-speed camera the time sequences of the classical flow patterns of horizontal gas-liquid pipe flow are recorded, from which the average gray-scale values of single-frame images are extracted. Thus obtained gray-scale time series is decomposed by the Empirical Mode Decomposition (EMD) method, the various scales of the signals are processed by Hurst exponent method, and then the dual-fractal characteristics are obtained. The scattered bubble and the bubble cluster theories are applied to the evolution analysis of two-phase flow patterns. At the same time the various signals are checked in the chaotic recursion chart by which the two typical characteristics (diagonal average length and Shannon entropy) are obtained. Resulting term of these properties, the dynamic characteristics of gas-liquid two-phase flow patterns are quantitatively analyzed. The results show that the evolution paths of gas-liquid two-phase flow patterns can be well characterized by the integrated analysis on the basis of the gray-scale time series of flowing images from EMD, Hurst exponents and Recurrence Plot (RP). In the middle frequency section (2nd, 3rd, 4th scales), three flow patterns decomposed by the EMD exhibit dual fractal characteristics which represent the dynamic features of bubble cluster, single bubble, slug bubble and scattered bubble. According to the change of diagonal average lengths and recursive Shannon entropy characteristic value, the structure deterministic of the slug flow is better than the other two patterns. After the decomposition by EMD the slug flow and the mist flow in the high frequency section have obvious peaks. Anyway, it is an effective way to understand and characterize the dynamic characteristics of two-phase flow patterns using the multi-scale non-linear analysis method based on image gray-scale fluctuation signals.

Cluster-size dependent randomization traffic flow model

In order to exhibit the meta-stable states, several slow-to-start rules have been investigated as modification to Nagel-Schreckenberg （NS） model. These models can reproduce some realistic phenomena which are absent in the original NS model. But in these models, the size of cluster is still not considered as a useful parameter. In real traffic, the slow-to-start motion of a standing vehicle often depends on the degree of congestion which can be measured by the clusters＇ size. According to this idea, we propose a cluster-size dependent slow-to-start model based on the speed- dependent slow-to-start rule （VDR） model. It gives expected results through simulations. Comparing with the VDR model, our new model has a better traffic efficiency and shows richer complex characters.

Detection of Intracellular Cytokine Production in Peripheral Blood CD_^+ T Cells of Patients with Recurrent Genital Herpes

To study the role of Th1/Th2 cytokines in the pathogenesis of recurrent genital herpes (RGH), and to better understand the relationship between them. Methods: A two-color immunofluorescent staining of cell surface antigen and intracellular cytokines for flow cytometric analysis was used for CD3, IL-2, IL-10, IL-12, IFN-y and TNF-a in CD3^+ T-lymphocytes in activated peripheral blood mononuclear cells of patients with RGH. Results: Compared to controls, patients with RGH showed fewer CD3^+ T cells (P<0.05) and IL-2 producing and IFN-7 producing T cells (P<0.02 and P<0.001, respectively)after in vitro stimulation with PMA and ionomycin in the presence of a protein transport inhibitor. More IL-10 producing and IL-12 producing T cells were found in patients with RGH (P<0.01). There was no significant difference in the number of TNY-α producing cells between RGH patients and controls (P<0.05). Conclusion: RGH patients showed relatively more Th2 cytokines. The imbalance between Thl and Th2 cytokines results in inhibitory effects on a series of cell-immune responses, which may play an important role in the pathogenesis of RGH.

基于电容传感器的CO_(2)气液两相流流型识别

为了实现碳捕捉与封存(CCS)管道内CO_(2)流量的精确测量,需要对CO_(2)的流型进行辨识。基于递归定量分析和模糊C均值(FCM)聚类算法,建立了CO_(2)气液两相流的流型识别模型。提出利用小波变换在多尺度下分析CO_(2)气液两相流电容信号递归图结构特性的方法,对各个尺度下的递归图分别进行定量分析,提取出不同流型下CO_(2)流动的电容传感器递归特征参数。采用FCM算法,对特征参数进行流型聚类,完成了对CO_(2)气液两相流的分层流、气泡流和雾状流3种流型的识别。

基于循环独立机制的交通流量预测

交通流量预测是智能交通控制和管理系统的一个重要环节,但交通流量数据具有时间和空间上的非线性和复杂性等特征,为对其进行精准预测,本文提出了Graph Temopral Recurrent Independent Mechanisms (G-tRIM)模型。该模型使用图注意力网络(Graph Attention Networks, GAT)来有效捕获交通流量数据的空间依赖关系,使用循环独立机制(Recurrent Independent Mechanisms, RIM)来精准刻画交通流量数据的潜在状态。最后在北京和贵州数据集上,以均方误差(Mean Square Error, MSE)和平均绝对误差(Mean Absolute Error, MAE)为指标进行实验,结果表明,G-tRIM在各个数据集上的表现均优于基准模型。

基于冠状动脉造影术中即刻新型评分系统对STEMI患者急诊PCI术中慢血流/无复流的预测价值和短期预后研究

目的基于临床指标和造影术中即刻影像学指标构建新型评分系统评估急性ST段抬高型心肌梗死(STEMI)接受急诊PCI(PPCI)术中慢血流/无复流的风险。方法本研究连续入选325例接受PPCI的STEMI患者作为建模组;另外连续入选412例患者作为验证组,用于验证该评分系统对慢血流/无复流(SF/NRF)的预测价值,并评估住院期间该评分系统高风险组与低风险组主要不良心血管事件的相关性。结果本研究使用5个变量建立SF/NRF预测模型。SF/NRF的独立预测因素为Killip≥2级、症状发作到球囊扩张时间≥4 h、初始TIMI血流0级、造影血栓负荷分级≥4和IRA管径≥3.5 mm。依据OR值对SF/NRF的独立预测因素进行赋分,进而建立SF/NRF的独立预测因素预测模型,使用受试者工作特征曲线(ROC)分析显示该模型评分≥7分对SF/NRF预测的敏感度为81.2%,特异度为72.3%(AUC=0.845,95%CI:0.788~0.902,P=0.012)。在验证队中使用该模型评分≥7分对SF/NRF预测的敏感度为78.2%,特异度为69.5%(AUC=0.752,95%CI:0.687~0.827,P=0.021)。在建模组、验证组和总人群中高危组(≥7分)住院期间主要不良心血管事件(MACE)显著高于对照组。结论基于冠状动脉造(冠脉)影术中即刻新型评分系统对STEMI患者PPCI术中SF/NRF具有良好的预测价值,且高风险组患者住院期间MACE显著高于低风险组。

低分子肝素与阿司匹林联合应用于子宫动脉血流阻力升高复发性流产保胎治疗中的效果

目的分析低分子肝素联合阿司匹林治疗子宫动脉血流阻力升高复发性流产的效果。方法选取150例复发性流产患者,采用随机表法分为对照组及研究组,每组75例。对照组采用地屈孕酮治疗,研究组采用低分子肝素联合阿司匹林治疗。对比两组患者的子宫动脉阻力指数、激素水平及凝血功能。结果治疗后,研究组左、右侧子宫动脉阻力指数分别为(0.52±0.11)、(0.46±0.12),均低于对照组的(0.72±0.13)、(0.72±0.16)(P<0.05)。治疗后,研究组各项激素指标水平及凝血功能指标水平均优于对照组(P<0.05)。结论低分子肝素联合阿司匹林可改善复发性流产患者的子宫动脉血流阻力,调节其激素水平,改善其凝血功能,具有保胎作用,值得推广应用。

舟曲虎家崖滑坡直接转化泥石流的特征、过程与机理研究

滑坡直接转化而成的泥石流通常比滑坡本身运移距离更远,波及范围更广,危害也更严重,但目前相关转化机制及其影响因素的研究较少。2020年10月20日位于白龙江左岸、甘肃省舟曲县的虎家崖暴发小型泥石流,侵入省道313,威胁毗邻村庄。通过现场调查、室内岩土试验、遥感解译和降雨资料分析,本文对虎家崖泥石流形成的地质环境条件、运移及堆积特征等进行了调查,研究了浅层滑坡失稳并直接转化为泥石流的主要特征、过程、影响因素及其形成机理,探讨其未来发展趋势。研究表明:(1)虎家崖上游狭长沟道堆积体受到长达19 d、累计98.5 mm的持续性降雨的激发而发生慢速滑坡,区域强震造成的坡体结构损伤对滑坡发育也有贡献。(2)滑坡后段与滑坡前缘的剪出部分在运动过程中直接转化为泥石流,但中段滑坡体则维持剪切滑动。(3)转化过程受滑坡前缘剪出土体饱水程度、沟道坡度与落差以及地表径流等因素的影响。(4)虎家崖狭长沟道后缘可能因毗邻泄流坡滑坡活动牵引而破坏,同时上游沟道残余滑坡体与灰岩崩塌体、出口右侧残余滑坡体可能受降雨、地震等激发而失稳,再次转化为泥石流,威胁沟道下方虎家崖村和省道S313。

子午流注择时电温针联合双补增津汤治疗结肠慢传输型便秘气阴两虚证的疗效观察

目的:观察子午流注择时电温针联合双补增津汤治疗结肠慢传输型便秘(STC)气阴两虚证的临床疗效。方法:选择符合纳入标准的152例STC气阴两虚证患者,按随机抽取法分为对照组(枸橼酸莫沙必利治疗)、电针组(枸橼酸莫沙必利+子午流注择时电温针治疗)、中药组(枸橼酸莫沙必利+双补增津汤治疗)和结合组(枸橼酸莫沙必利+子午流注择时电温针+双补增津汤治疗),每组各38例,均治疗4周。观察比较4组患者治疗前后中医症状积分和总积分、结肠传输试验标志物含量、肠道菌群数量、焦虑自评量表评分(SAS)、抑郁自评量表评分(SDS)、慢性便秘严重度评分(CSS)的变化情况,比较临床疗效及随访6个月复发率。结果:4组患者治疗后中医症状积分和总积分、结肠传输试验标志物含量和SAS、SDS、CSS评分均较治疗前比较均明显下降(P<0.05),肠道内大肠埃希数量与治疗前比较明显减少(P<0.05),双歧杆菌、乳酸杆菌数量与治疗前比较明显增多(P<0.05);结合组临床疗效明显优于其他3组(P<0.05),随访期复发率明显低于其他3组(P<0.05)。结论:子午流注择时电温针联合双补增津汤治疗STC气阴两虚证的疗效显著,二者可发挥协同增效作用,能有效缓解便秘症状,调节肠道菌群,恢复肠道运动功能,改善焦虑、抑郁心理状态,降低复发率。

冠状动脉慢血流与QRS波群离散度关系的研究

目的:探讨冠状动脉慢血流与QRS波群离散度的关系。方法:我们回顾分析2021年至2022年间,北京安贞医院经冠状动脉造影明确SCF患者18例,对照组由23例年龄和性别匹配的冠状动脉造影完全正常者组成,测量两组患者的心电图数据中Tpe(T波峰值至终点的间隔时间)、Tpe/QT、QTd(QT离散度)、QTcd(校正QT离散度)数值,分析SCF患者中QRS波离散度同血流帧数之间的关系。结果:与对照组相比,SCF组的平均Tpe、Tpe/QT、QTd、QTcd延长(P<0.05)。与对照组相比,SCF组的TIMI帧数明显升高(P<0.05)。结论:SCF患者心电图中Tpe、Tpe/QT、QTd、QTcd的延长,预测室性心律失常的风险增加。

青年与老年冠状动脉慢血流患者临床特点对比研究

背景冠状动脉慢血流(CSF)现象表现为反复发作的静息型心绞痛,可能会导致急性心肌梗死、致命性的心律失常和心源性猝死等严重的心血管事件,并降低患者的生活质量。随着冠状动脉造影(CAG)的安全性、可行性、可靠性的提高,CSF的检出率逐渐增高,但国内外对早发CSF机制、青年CSF患者的临床特点对比分析较少。目的初步探讨青年CSF患者的临床特点,并与老年CSF患者相比较,为探索早发CSF机制提供方向与思路。方法连续性分析2017年1月—2019年1月在中国人民解放军第三〇五医院心内科住院经CAG诊断为CSF的青年(18岁≤年龄<45岁)患者86例作为青年组,随机抽取同期≥65岁的CSF患者88例作为老年组。收集整理两组患者的临床资料,包括病史、诊断,以及实验室相关检查和CAG结果,进行对比分析。结果青年组患者平均年龄、高血压比例、糖尿病比例低于老年组,男性比例、BMI高于老年组(P<0.05)。青年组患者CSF累及血管支数以单支为主(58.1%),老年组患者CSF累及血管支数以三支为主(45.5%);两组患者CSF累及血管支数分布比较,差异有统计学意义(χ^(2)=29.521,P<0.001)。青年组患者CSF累及血管总数为137个,老年组患者CSF累及血管总数为199个;两组患者CSF累及血管分布比较,差异无统计学意义(χ^(2)=1.366,P=0.644)。青年组患者三酰甘油(TG)、血尿酸(SUA)、高敏C反应蛋白(hs-CRP)、内皮素1(ET-1)水平高于老年组,一氧化氮(NO)水平低于老年组(P<0.05)。结论与老年CSF患者相比,青年CSF患者中男性多,BMI高,CSF累及血管个数少,TG、SUA、hs-CRP、ET-1水平较高,而高血压、糖尿病比例较低。提示代谢异常、炎症反应以及血管内皮功能受损与青年CSF的发病更为密切相关。

冠状动脉慢血流患者发生主要不良心血管事件的影响因素分析

目的分析冠状动脉慢血流患者(CSFP)随访期间发生主要不良心血管事件(MACE)的影响因素。方法采用回顾性观察性研究设计,纳入安庆市立医院2019年1月至2023年1月因胸痛入院行冠状动脉造影首次诊断CSFP患者249例,通过医护人员定期对入组患者门诊随访信息收集、患者或家属进行电话随访,前瞻性随访所有符合纳入标准患者MACE发生情况(包括因胸痛再住院、非致死性心肌梗死及心源性死亡),随访截止日期2023年9月。使用单因素及多因素Cox回归分析发生MACE的影响因素。结果平均随访24.2月,共有50例(20.1%)患者发生MACE,其中46例(18.5%)因胸闷胸痛再住院,4例(1.6%)发生非致死性心肌梗死。单因素及多因素Cox回归均提示,糖尿病、平均校正TIMI血流帧数(mcTFC)和低密度脂蛋白胆固醇(LDL-C)水平与CSFP患者随访期间发生MACE相关,缺失数据多重填补后分析及完整数据分析结论一致,将mcTFC及LDL-C行分类变量转换后,Kaplan-Meier分析CSFP患者不同组组间MACE发生率有统计学差异,Log-rankP均<0.05。结论糖尿病、mcTFC、LDL-C对CSFP患者随访期间发生MACE有一定预测价值。

三酰甘油-葡萄糖指数与冠状动脉慢血流的相关性研究

目的分析冠状动脉慢血流(CSF)相关风险因素,使用限制性立方样条(RCS)模型探究三酰甘油-葡萄糖(TyG)指数与CSF之间剂量-反应关系,进一步了解胰岛素抵抗(IR)与CSF发生间的关系。方法回顾性选取2021年6月至2023年5月就诊于新疆医科大学第五附属医院完善冠状动脉造影检查明确诊断为CSF的115例患者作为CSF组,另选取同期健康体检的121例无冠状动脉血流异常者作为正常血流组进行研究。运用多因素logistic回归分析发生CSF的相关风险因素,对TyG指数进行分组,运用RCS模型明确TyG指数与CSF之间的剂量-反应关系。结果多因素logistic回归分析结果表示,吸烟史(β=1.538,OR=4.655,95%CI:2.332~9.681)、收缩压(β=0.077,OR=1.080,95%CI:1.051~1.113)、低密度脂蛋白胆固醇(β=0.552,OR=1.737,95%CI:1.156~2.676)和TyG指数(β=1.072,OR=2.922,95%CI:1.629~5.475)为CSF的危险因素,淋巴细胞计数(β=-0.941,OR=0.390,95%CI:0.218~0.680)和左室射血分数(β=-0.126,OR=0.881,95%CI:0.813~0.944)为CSF的保护因素。RCS模型结果表示,TyG指数与CSF之间存在剂量-反应关系(P-overall<0.001,P-non-linear=0.001)。结论TyG指数为CSF的独立危险因素,二者之间存在非线性剂量-反应关系,IR可能与CSF的发生机制相关。