Evaluation of Bleeding Risk by Hemostatic Parameters in Hemodialysis at the Douala General Hospital: Comparison between Patients on Hemodialysis before 3 Months and after 12 Months

Background: Bleeding disorders are common and may be a life-threating complication among patients with End Stage Kidney Disease (ESKD), especially for those in hemodialysis (HD). Bleeding risk can be evaluated by hemostatic parameter such as platelet count, prothrombine time (PT) or activated prothromplastin time (aPTT) and may be influenced by duration in HD. Objective: Evaluate bleeding risk in HD patients by analyzing some hemostatic parameters according to duration in dialysis. Patients and methods: We conducted a cross sectional study of 3 months (March to May 2022) in the HD center of the Douala General Hospital. All consenting adult patients with ESKD admitted in HD for less than 3 months or more than 12 months were included. Bleeding risk was evaluated by platelet count, PT, aPTT and fibrinogen. Chi-square test and logistic regression were used to compare data and evaluate association with hemostatic disorder. Results: A total of 80 (60% male) patients were included;30 patients were on HD for less than 3 months and 50 for more than 12 months. Median age was 45 [30 - 60] years in the first group and 43 [30 - 55] years in the second group. Increased bleeding risk was noted in 50% (n = 40) of patients and was similar in both groups. Thrombocytopenia was more common in patients on HD ≥ 12 months (20% (n = 6) vs 44% (n = 22), p = 0.02). Prolong aPTT was more common in HD patients ≥ 3 months (OR = 6.6 [1.88 - 23.5], p = 0.0013) and those with HD catheter (OR = 21.3 [4.6 - 45.7], p < 0.001). Fibrinogen and PT were comparable in both groups. HD catheter was associated with prolong PT (OR = 5.3 CI [1.5 - 8.9], p = 0.03). Conclusion: Increased bleeding risk is common in HD patients. Thrombocytopenia is common in HD patients ≥ 12 months, while prolong aPTT are mainly found in HD patients ≤ 3 months with catheter and may reflect heparin overdose.

Influences of different time intervals between loop electrosurgical excision and abdominal hysterectomy or radical hysterectomy on postoperative complications: a retrospective analysis

Objective： To study the influences of different time intervals between loop electrosurgical excision （LEEP） and abdominal hysterectomy or radical hysterectomy on postoperative complications. Methods： Sixty-eight patients, who received subsequent abdominal hysterectomy or radical hysterectomy after LEEP due to C1N III and cervical cancer （IA1, IA2 and IB1）, were included in the present study. The hospital and clinic records of these patients were reviewed. The patients were divided into three groups according to the time intervals between LEEP and hysterectomy or radical hysterectomy： group l（within 48 h）, group 2 （between 48 h to 6 weeks）, and group 3（〉 6 weeks ）.Results： General characteristics of patients, including the mean age, delivery history, BMI, menopausal status, clinical stage and HPV infection, were comparable between patients of different groups. There were no significant differences in the mean transfusion amount, posthysterectomy hospital stay or operation time between different groups. The frequencies and spectrum of complications were not significantly affected by the time interval between LEEP and hysterectomy or radical hysterectomy. Conclusion： It is concluded that whenever the LEEP is done, the operation including hysterectomy or radical hysterectomy can be conducted at any time as it is necessary for the patients.

Effect of Optimization of Hemodialysis on Ophthalmological Variables in Patients with End Stage Renal Disease

Background: Conventional hemodialysis (HD) used in treating end stage renal disease (ESRD) can result in multiorgan insult including the eye-owing to the resultant reperfusion after the ischemic event. Optimization of HD can be done using a process called remote ischemia which includes applying cycles of brief, nonlethal ischemia followed by reperfusion to one limb. This method sends signal to the end organs to prepare themselves for the upcoming ischemia thus preventing their injury. Aim: To evaluate the effect of remote ischemia preconditioning in HD on ophthalmological variables. Patients and Methods: A pre-post interventional analytical study conducted on patients receiving hemodialysis. Remote ischemia preconditioning was done before each HD session incorporating 3 cycles of alternating ischemia and reperfusion (5 minutes each) performed in the upper limb using sphygmomanometer cuff. Ophthalmic examination was done at baseline and 3 months after HD optimization. Assessment was done half to one hour pre- and post-session for visual acuity, corneal, conjunctival deposits, tear break up time (TBUT), anterior chamber depth and central macular thickness. Results: The study included 50 eyes of 25 patients with almost equal gender distribution and mean age of 37.52 ± 9.824 years. They were maintained on hemodialysis for median 10 years (range 3-25 years). The commonest cause of ESRD was hypertension. The studied ocular parameters showed insignificant change after pre-conditioned HD except for TBUT that was statistically longer (p = 0.018). Conclusion: Optimization of hemodialysis using remote ischemia does not seem to have significant ocular effect apart from prolonged TBUT. .

Variational Inference Based Kernel Dynamic Bayesian Networks for Construction of Prediction Intervals for Industrial Time Series With Incomplete Input

Prediction intervals(PIs)for industrial time series can provide useful guidance for workers.Given that the failure of industrial sensors may cause the missing point in inputs,the existing kernel dynamic Bayesian networks(KDBN),serving as an effective method for PIs construction,suffer from high computational load using the stochastic algorithm for inference.This study proposes a variational inference method for the KDBN for the purpose of fast inference,which avoids the timeconsuming stochastic sampling.The proposed algorithm contains two stages.The first stage involves the inference of the missing inputs by using a local linearization based variational inference,and based on the computed posterior distributions over the missing inputs the second stage sees a Gaussian approximation for probability over the nodes in future time slices.To verify the effectiveness of the proposed method,a synthetic dataset and a practical dataset of generation flow of blast furnace gas(BFG)are employed with different ratios of missing inputs.The experimental results indicate that the proposed method can provide reliable PIs for the generation flow of BFG and it exhibits shorter computing time than the stochastic based one.

The burden of upper motor neuron involvement is correlated with the bilateral limb involvement interval in patients with amyotrophic lateral sclerosis:a retrospective observational study

Amyotrophic lateral sclerosis is a rare neurodegenerative disease characterized by the involvement of both upper and lower motor neurons.Early bilateral limb involvement significantly affects patients'daily lives and may lead them to be confined to bed.However,the effect of upper and lower motor neuron impairment and other risk factors on bilateral limb involvement is unclear.To address this issue,we retrospectively collected data from 586 amyotrophic lateral sclerosis patients with limb onset diagnosed at Peking University Third Hospital between January 2020 and May 2022.A univariate analysis revealed no significant differences in the time intervals of spread in different directions between individuals with upper motor neuron-dominant amyotrophic lateral sclerosis and those with classic amyotrophic lateral sclerosis.We used causal directed acyclic graphs for risk factor determination and Cox proportional hazards models to investigate the association between the duration of bilateral limb involvement and clinical baseline characteristics in amyotrophic lateral sclerosis patients.Multiple factor analyses revealed that higher upper motor neuron scores(hazard ratio[HR]=1.05,95%confidence interval[CI]=1.01–1.09,P=0.018),onset in the left limb(HR=0.72,95%CI=0.58–0.89,P=0.002),and a horizontal pattern of progression(HR=0.46,95%CI=0.37–0.58,P<0.001)were risk factors for a shorter interval until bilateral limb involvement.The results demonstrated that a greater degree of upper motor neuron involvement might cause contralateral limb involvement to progress more quickly in limb-onset amyotrophic lateral sclerosis patients.These findings may improve the management of amyotrophic lateral sclerosis patients with limb onset and the prediction of patient prognosis.

Time Intervals of the Electron Transitions between the Energy States in the Hydrogen Atom Calculated in a Non-Probabilistic Way

Definitions of the mechanical parameters entering the Bohr model of the hydrogen atom allowed us to calculate the time intervals connected with the electron transitions between the nearest-neighbouring energy levels in the atom. This is done in a strictly non-probabilistic way. The time results are compared with those derived earlier on the basis of the classical Joule-Lenz law for the energy emission adapted to the case of the electron transfer in the quantum systems. A similar formalism has been next applied to the harmonic oscillator and a particle moving in the one-dimensional potential box.

Relation between the Intervals ΔE and Δt Obtained in the De-Excitation Process of Electrons in Metals

A relation between the intervals of energy and time, derived in a former paper and associated with the electron transitions on the Fermi surface of a metal, is examined in comparison with the experimental data. These data are obtained from the de-excitation process of electrons in metals. A comparison between theory and experiment demonstrated that the new relation between energy and time is fitted much better for the experimental results than the well-known relation due to the Heisenberg theory.

Impact of interval between neoadjuvant chemoradiotherapy and surgery in rectal cancer patients

BACKGROUND Epidemiologically,in China,locally advanced rectal cancer is a more common form of rectal cancer.Preoperative neoadjuvant concurrent chemoradiotherapy can effectively reduce the size of locally invasive tumors and improve disease-free survival(DFS)and pathologic response after surgery.At present,this modality has become the standard protocol for the treatment of locally advanced rectal cancer in many centers,but the optimal time for surgery after neoadjuvant therapy is still controversial.AIM To investigate the impact of time interval between neoadjuvant therapy and surgery on DFS and pathologic response in patients with locally advanced rectal cancer.METHODS A total of 231 patients who were classified as having clinical stage II or III advanced rectal cancer and underwent neoadjuvant chemoradiation followed by surgery at the National Cancer Center/Cancer Hospital,Chinese Academy of Medical Sciences and Peking Union Medical College from November 2014 to August 2017 were involved in this retrospective cohort study.The patients were divided into two groups based on the different time intervals between neoadjuvant therapy and surgery:139(60.2%)patients were in group A(≤9 wk),and 92(39.2%)patients were in group B(>9 wk).DFS and pathologic response were analyzed as the primary endpoints.The secondary endpoints were postoperative complications and sphincter preservation.RESULTS For the 231 patients included,surgery was performed at≤9 wk in 139(60.2%)patients and at>9 wk in 92(39.8%).The patients’clinical characteristics,surgical results,and tumor outcomes were analyzed through univariate analysis combined with multivariate regression analysis.The overall pathologic complete response(pCR)rate was 27.2%(n=25)in the longer time interval group(>9 wk)and 10.8%(n=15)in the shorter time interval group(≤9 wk,P=0.001).The postoperative complications did not differ between the groups(group A,5%vs group B,5.4%;P=0.894).Surgical procedures for sphincter preservation were performed in 113(48.9%)patients,which were not significantly different between the groups(group A,52.5%vs group B,43.5%;P=0.179).The pCR rate was an independent factor affected by time interval(P=0.009;odds ratio[OR]=2.668;95%CI:1.276-5.578).Kaplan-Meier analysis and Cox regression analysis showed that the longer time interval(>9 wk)was a significant independent prognostic factor for DFS(P=0.032;OR=2.295;95%CI:1.074-4.905),but the time interval was not an independent prognostic factor for overall survival(P>0.05).CONCLUSION A longer time interval to surgery after neoadjuvant therapy may improve the pCR rate and DFS but has little impact on postoperative complications and sphincter preservation.

Discussion of the Horizontal Intensity of Late Quaternary Fault Activity Along the Tianjingshan Fault Zone in Different Time Intervals and Fault Segments

By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are discussed in different time intervals and fault segments.The results suggest that the intensity of activity along the fault zone is not strong,but the differences between different time intervals and fault segments since the late Pleistocene have been obvious.The average rates range from 0.23 mm/a to 1.62 mm/a.The largest average rate is 1.40 mm/a,which occurred in the early and middle of late Pleistocene along the western segment of the fault zone.Since the late stage of the late Pleistocene,the center of faulting activity of the fault zone has shifted to the middle segment,and the average slip rates range have changed from 1.30 mm/a to 1.63 mm/a.

Relativistic Reduction of the Electron-Nucleus Force in Bohr’s Hydrogen Atom and the Time of Electron Transition between the Neighbouring Quantum Energy Levels

The aim of the paper is to get an insight into the time interval of electron emission done between two neighbouring energy levels of the hydrogen atom. To this purpose, in the first step, the formulae of the special relativity are applied to demonstrate the conditions which can annihilate the electrostatic force acting between the nucleus and electron in the atom. This result is obtained when a suitable electron speed entering the Lorentz transformation is combined with the strength of the magnetic field acting normally to the electron orbit in the atom. In the next step, the Maxwell equation characterizing the electromotive force is applied to calculate the time interval connected with the change of the magnetic field necessary to produce the force. It is shown that the time interval obtained from the Maxwell equation, multiplied by the energy change of two neighbouring energy levels considered in the atom, does satisfy the Joule-Lenz formula associated with the quantum electron energy emission rate between the levels.

Improved results on passivity analysis of discrete-time stochastic neural networks with time-varying delay

The problem of passivity analysis for a class of discrete-time stochastic neural networks (DSNNs) with time-varying interval delay was investigated. The delay-dependent sufficient criteria were derived in terms of linear matrix inequalities (LMIs). The results are shown to be generalization of some previous results and are less conservative than the existing works. Meanwhile, the computational complexity of the obtained stability conditions is reduced because less variables are involved. A numerical example is given to show the effectiveness and the benefits of the proposed method.

海底节点同步源高效混叠采集随机延迟时间序列分布原则研究

近年来,海底节点(OBN)同步震源高效采集方法的研究成为地震勘探领域的热点之一。陆地可控震源数据分离激发参数的选择有时间延迟、相位、扫描长度等3种编码方式。但是,由于海上空气枪激发的特点,相位和扫描长度编码适用性差。只能采用时间延迟编码方式。海上混叠采集时间延迟序列的编码是影响数据分离效果的最关键因素之一。提出了一种基于正态分布约束的均匀随机时间分布定量编码准则,通过目标函数约束构建最优时间序列,并对比分析了实际自然随机激发时间和其它2种理论模拟的随机时间分布方式在共检波点域的分布特征。利用频率波数波数(FKK)域迭代反演方法进行混叠数据分离,单炮模拟测试结果表明,构建的最优时间序列比其它3种分布方式更能有效地分离混叠地震数据。海上三维工区高效混叠采集试验结果表明,根据最优准则构建的延迟时间序列,能够取得较好的数据分离效果。该研究结果为后续野外混叠采集的延迟激发时间设计提供了技术支持。

柴达木盆地北缘断裂锡铁山-阿木尼克山段第四纪晚期古地震活动性

柴达木盆地北缘断裂带是青藏高原北部的一条区域性活动断裂带,构成了柴达木盆地北部和祁连山的边界断裂,研究其第四纪晚期古地震活动对于理解柴达木盆地北缘断裂带地震复发周期、地震危险性等具有重要意义。通过地质考察、遥感解译、探槽开挖及OSL地质测年、古地震期次分析等,对柴达木盆地北缘断裂(锡铁山-阿木尼克山段)古地震事件进行了研究。研究表明:探槽剖面共揭露了5次比较可靠的古地震事件,发震时间分别为:事件E1距今约60 a;事件E23.1±0.3~3.4±0.3 ka;事件E37.5±0.3~8.1±0.3 ka;事件E410.1±0.4~11.4±0.4 ka;事件E512.1±0.4~12.8±0.4 ka。利用古地震逐次限定法认为柴达木盆地北缘断裂(锡铁山-阿木尼克山段)地震复发周期为2.6~3.4 ka。阿木尼克山段最新离逝时间为60年前,锡铁山段最新离逝时间为3.1±0.3 ka,分析认为柴达木盆地北缘断裂锡铁山段未来遭遇破坏性地震的可能性大于阿木尼克山段。该结果可以更好地了解柴达木盆地北缘断裂的古地震期次、复发间隔等,对地震预报预测及评价该断裂未来地震危险性具有一定的指导意义。

一种应用于TDMA无线传感网的低能耗同步机制

为了降低时分多址网络中时钟同步所导致的节点能耗,根据节点晶振器件的潜在漂移,提出了一种应用于星型无线传感网的低能耗同步机制。该机制中整个时间轴由长帧组成,每个长帧包含一个同步帧与多个子帧,每个子帧由所有子节点绑定的子时隙构成。根节点在长帧开始时发送同步帧,使得所有子节点时钟同步。每个子时隙增加了相应的保护间隔,有效地避免子节点之间因时钟漂移导致时隙间相互影响,从而最大限度地增加长帧中的子帧数量,降低子节点唤醒进行同步的频率。与传统的TDMA每个子帧均需同步相比,从接收同步帧角度来讲,大幅度减少了子节点能耗。最后,假定晶振频率误差为正态分布的情况下,利用MATLAB进行仿真,验证了该低能耗同步模型公式的正确性,并将仿真情况在CC1310器件构建的星型网上进行了应用验证。

风电不确定性输入下电力系统仿真的区间仿射算法

大规模的风电机组并网改变了以同步发电机为主的传统电力系统的暂态特性,此外风电出力的随机性会影响电力系统的暂态稳定性。为此,文中提出了基于仿射算术的电力系统不确定性时域仿真算法,以考虑风电出力的波动性。在双馈风电机组机电暂态模型的基础上,扩展电力系统机电暂态模型,建立考虑双馈风电机组输入功率波动下的电力系统机电暂态仿射模型,通过隐式梯形积分法将仿射模型转化为的仿射雅克比矩阵方程迭代求解。仿真结果表明,文中所提出的仿射方法在不假设输入不确定量概率分布的情况下,能够较蒙特卡洛仿真更快地获得电力系统暂态响应的区间边界。

缩短解压间隔时间对经皮冠状动脉介入治疗术后病人的影响

目的:探讨缩短解压间隔时间在经皮冠状动脉介入治疗(percutaneous coronary intervention, PCI)术后病人中的应用效果。方法:便利选取2021年11月-2022年8月入住聊城市某三级甲等综合医院心内科114例行桡动脉PCI的病人作为研究对象,采用随机数字表法分为试验组56例和对照组58例。两组病人住院期间经桡动脉行PCI术后,均接受螺旋式桡动脉压迫止血器止血,试验组至少每1 h解压1次,对照组病人给予常规每2 h解压1次。比较两组桡动脉PCI术后病人桡动脉压迫时间、并发症、舒适度。结果:桡动脉PCI术后病人桡动脉压迫时间比较,试验组(5.1±1.2)h,少于对照组(6.5±2.4)h(P<0.05);在出血并发症方面,差异无统计学意义(P>0.05);在血肿并发症方面,差异无统计学意义(P>0.05);在肿胀并发症方面,试验组和对照组发生率分别为3.6%、20.7%,试验组少于对照组(P<0.05);在皮肤压力性损伤并发症方面,试验组和对照组发生率分别为0.0%、12.1%,试验组少于对照组(P=0.013);在舒适度方面,试验组舒适度为(72.4±7.9)分,对照组舒适度为(54.1±6.3)分,试验组优于对照组(P<0.05)。结论:缩短解压间隔时间能有效缩短经桡动脉行PCI术后病人桡动脉压迫时间,减少并发症,改善病人舒适度,促进病人康复。

基于张量表示的间歇性序列自适应区间预测

在实际业务中,配件需求发生随机、需求量波动大,配件序列数据呈现明显的间歇性分布,同时由于人工报单失误或特殊事件等因素的影响,实际配件需求易发生异常变化,导致传统的时间序列预测方法难以捕捉配件需求量的演化规律,预测结果不确定性高、可靠性不足。为解决上述问题,提出了一种基于张量表示的间歇性序列自适应区间预测方法。首先,利用层次聚类,基于间歇性序列的平均需求间隔和平方变异系数指标筛选相似序列形成序列簇,用于提取簇内公共需求演化信息,增加可预测性;其次,通过张量分解重构原始需求序列,在最大限度保留序列核心信息的前提下平滑序列中的异常值;最后,构建一种自适应预测区间算法,通过动态更新机制得到配件需求量的预测值和预测区间,以确保结果的可靠性。利用某大型轨道交通制造企业实际售后数据进行验证,与现有典型时间序列预测方法相比,所提方法可有效挖掘不同特点间歇性序列的演化趋势,提高小样本间歇性序列的预测精度。实验结果表明:所提方法在间歇性特有指标均方根标准误差(RMSSE)上,相较于需求预测主流的深度学习方法平均降低了0.32,且当预测结果出现失真时,可提供一个可靠的弹性预测区间,为实际应用中企业智能备件计划决策提供了一种新的解决方案。

爆破振动强度、波形与频谱研究综述:预测及主动控制

岩石钻孔爆破不可避免地会产生爆破振动效应及危害,准确预测爆破振动效应并进行主动控制具有极大的现实意义。论文综述了近40年来,国内外研究人员在爆破振动预测及主动控制方面取得的研究成果。在爆破振动速度峰值(PPV)预测方面,经验模型预测方法体现出了较大的便捷性,但预测精度与效果较差,将概率统计理论引入经验模型预测方法,提高了PPV预测精度;而基波叠加预测方法可实现对振速、频率和持续时间的综合预测,但是该方法对振动基波的测试精度要求较高,同时亟须在行业内建立对爆破振动采集设备的定期标定与校核机制;人工智能预测方法极大提高了PPV预测精度,同时为多因素影响下的爆破振动效应预测提供了新思路,但需要建立在海量真实有效实测数据的基础上,目前还缺乏充实的振动测试样本数据库;PPV预测理论模型及数值模拟预测法对理论与专业知识、数值模拟技术等要求高,限制了两种方法在工程的普遍应用。在爆破振动速度主动控制上,可以确定合理的延期时间,采用毫秒延迟干扰减振法来降低PPV,但目前多为单一防护对象所提出的延期时间建议值;从调整爆破振动频谱结构的角度,通过主动改变延期时间调控爆破振动频率成分,可避开建(构)筑物自振频带,减小爆破振动危害,然而目前仅仅停留在理论层面或模型试验尺度条件下,缺乏大规模的现场应用实例。最后,对未来爆破振动预测及控制方面重点研究内容进行了展望。

时间感知的用户长短期兴趣特征分离推荐算法

针对传统推荐算法未充分考虑行为序列间的动态时间间隔、语义不规则以及用户长短期兴趣相互纠缠的问题,提出一种时间感知的用户长短期兴趣特征分离推荐算法。利用用户个性化时间聚合间隔感知和时间位置多头注意力捕获长期兴趣特征,采用动态时间间隔感知和潜在意图注意力的Time-LSTM捕获短期兴趣特征,提出长短期兴趣特征分离获取方法,分别独立捕获两种时间尺度的用户兴趣,通过注意力机制自适应融合长短期兴趣特征,提高用户兴趣特征捕获准确率。实验结果表明,该算法在预测精度指标AUC和GAUC上较对比算法均有提升,消融实验也进一步验证了该算法的必要性。

不同运动时间和间歇模式的大强度间歇运动对愉悦情绪和享受感的影响

探讨4种不同运动时间和间歇模式的大强度间歇运动(HIIT)诱发愉悦情绪和享受感的效果差异。方法:将75名大学生随机分配至运动30 s间歇30 s组、运动1 min间歇1 min组、运动30 s间歇1min组和运动1 min间歇2 min组,分别于运动前、运动后即刻和20 min测量其享受感,并对运动中的疲劳感、愉悦情绪和享受感进行测试。结果:1)运动30 s间歇1 min HIIT相比运动1 min间歇2 min,运动30 s间歇30 s HIIT相比运动1 min间歇1 min HIIT均可诱发更积极的愉悦情绪。运动30 s间歇1 min HIIT诱发的愉悦情绪最高,运动1 min间歇1 min HIIT诱发的愉悦情绪最低。2)1:1间歇模式HIIT诱发的享受感水平低于1:2间歇模式,并且与运动30 s间歇30 s、运动1 min间歇1 min HIIT相比,运动1min间歇2 min HIIT诱发的享受感水平更高。3)运动30 s间歇1 min HIIT诱发的享受感水平显著高于运动1 min间歇1 min,相同间歇模式HIIT诱发的享受感水平没有显著差异。结论:1)运动时间和间歇时间等量时,运动时间越长,愉悦情绪越低,运动时间小于间歇时间的HIIT诱发的愉悦情绪更高。2)间歇期长的HIIT诱发的享受感水平更高,相同间歇模式的运动时间长短不影响运动后产生的享受感。3)短时间多组数HIIT是诱发愉悦情绪的最佳方案,长时间的间歇期HIIT是诱发享受感的最佳方案。