下肢动脉硬化闭塞症患者介入术后复发风险的列线图模型构建及验证

目的探讨构建下肢动脉硬化闭塞症(ASO)患者介入术后的预测模型预测患者介入术后复发的风险。方法纳入我院2020年7月—2022年9月血管外科经过介入治疗的病例170例为研究对象,收集患者一般资料,根据有无复发分为复发组(n=56)和非复发组(n=114)。根据Lasson回归筛选预测因子,再利用R软件建立列线图预测风险模型。用ROC曲线对该模型进行评估,并采用Bootstrap进行内部验证,计算C指数判断预测模型的区分度及模型校准度。结果单因素分析发现复发组和非复发组患者糖尿病、高血压、吸烟史、术后规律用抗血小板及降脂药、手术方式、钙化长度等影响因素比较,差异均有统计学意义(P<0.05)。根据Lasson回归筛选出糖尿病、高血压、吸烟史、术后规律用抗血小板及降脂药、手术方式、钙化长度6个预测因子,利用上述变量建立1年复发风险列线图预测模型,预测模型结果显示,ROC曲线提示AUC为0.754,原模型的C-index指数和Brier评分分别为0.765(95%CI:0.687~0.842)、0.172(95%CI:0.140~0.204),反复抽样500次以后的内部验证的C-index指数和Brier评分分别为:0.733(95%CI:0.623~0.842)、0.189(95%CI:0.139~0.246)。结论糖尿病、高血压、吸烟史、术后规律用抗血小板及降脂药、手术方式、钙化长度是影响ASO介入术后复发的重要影响因素。该模型能较好的评估患者介入治疗后的复发风险,具有一定的临床价值。

配位不饱和Au-O-Ti^(3+)活性位点的构建及其在低温丙烯气相环氧化反应中强化氢气效率的研究

自1998年以来,人们广泛认为Au/Ti基催化剂的Au-O-Ti^(4+)位点是在相对高温条件下丙烯气相环氧化反应的活性位点,但该类催化剂的H_(2)有效利用率普遍较低。本工作发现了一种在相对低温条件下丙烯气相环氧化反应的新活性位点Au-O-Ti^(3+)。值得注意的是,该活性位点主导反应时,最佳温度可从200℃显著降低至138℃,并使催化剂保持前所未有的43.6%的H_(2)有效利用率、90.7%的环氧丙烷(PO)选择性和超过100 h的稳定性。本工作通过调整处理后S-1晶种中Si-OH和Bu3NH+的量,定量构建了Au-O-Ti^(3+)活性位点。并且利用原位紫外-可见光谱(operando UV-vis)技术研究了Ti-OOH反应中间体的动态演化过程,结果表明,在Au-O-Ti^(3+)活性位点上的Ti-OOH的生成速率比在Au-O-Ti^(4+)活性位点上的明显增高。此外,氨程序升温脱附(NH3-TPD)和X射线光电子能谱(XPS)表征以及密度泛函数理论(DFT)计算表明,在相对低温条件下,Au-O-Ti^(3+)活性位点中配位不饱和Ti^(3+)位点促进了Au和Ti^(3+)之间的电子转移,从而增强了催化剂对O_(2)的吸附能力,有效促进H_(2)O_(2)的原位生成,并进一步促进活性中间体Ti-OOH的形成。本工作所报道的结果为强化丙烯直接气相环氧化反应的H_(2)有效利用率提供了新的思路,而且为低温下丙烯直接气相环氧化反应的工业化推进开辟了新的机会。

赤平极射-实体比例投影方法及其应用

赤平极射-实体比例投影方法在岩质边坡的稳定性分析中具有独特的优势。以黑山谷某岩质边坡为例,采用赤平极射-实体比例投影对该边坡进行了综合性分析,分析了滑坡的滑动机制、滑动方向、滑面面积、滑体体积等重要特征,并通过赤平极射-实体比例投影方法对该岩质边坡的稳定性进行了分析,讨论了赤平极射-实体比例投影方法和传统极限平衡法中的传递系数法的优缺点,认为赤平极射-实体比例投影法在岩质边坡稳定性分析中比传递系数法更具有优势,该方法能够为岩质边坡的防护提供参考。

压实土体崩解特性的试验研究

基于传统崩解试验方法精度较低的问题,研制了一套压实土体崩解试验系统。查明了压实土体试验中崩解时间和崩解量的变化规律,利用自主研制的试验装置,开展了崩解试验研究。分析了含水率、密实度、颗粒级配、颗粒种类等因素对压实土体崩解时间和崩解量的影响。试验结果表明:对于砂岩颗粒土料,含水率对崩解量和崩解时间的影响较大;而相对密实度对崩解量和崩解时间影响较小。对于泥岩颗粒土料,含水率对试样的崩解量和崩解时间影响不显著;而相对密实度对崩解量和崩解时间影响较大。对于不同级配的砂岩、泥岩颗粒土料,细颗粒含量越多,抗崩解性也随之增强,崩解时间越短崩解量越大。

基于动态强度双折减系数法的滑坡灾变过程模拟

为了模拟滑坡的灾变过程,提出了动态强度双折减系数法,实现了对滑坡折减系数的合理分布,通过对李家湾滑坡灾变过程的模拟,分析了各个位移分量变化趋势。结果表明,位移突变以破积土前缘最为突出,依据应变累积速率的不同,可以将整个灾变过程划分为稳定状态、欠稳定状态和失稳状态。通过失稳判别和双折减系数的处理,对李家湾滑坡进行了稳定性评价。结果表明,动态强度双折减系数法评价滑坡稳定性偏于安全,经过处理得到的滑坡综合安全储备都要小于整体强度折减法的结果,但两者的结果相近,说明动态双折减系数折减在用于滑坡的灾变过程模拟和稳定性评价都是合理的。

基于RTDS的孤立电网的极端运行情况仿真研究

以中国内蒙古东部地区即将建成的一个高风电渗透率的微电网为研究对象,依据系统不同运行方式及故障情况下的系统备用容量和损失功率,按照四边界法选取了四种极端情况的算例,深入分析该系统孤立运行时,电网的频率电压特性以及控制策略,为实际孤立电网的安全稳定控制提供参考方案。

D-二聚体对急性胰腺炎预后预测价值的Meta分析

目的探讨D-二聚体对急性胰腺炎(acute pancreatitis, AP)患者预后预测价值.方法计算机检索Medline、EMBASE、Cochrane图书馆、CBM网络版和CNKI等数据库,收集D-二聚体水平升高对AP患者预后影响的临床研究,对符合纳入标准的研究进行质量评价和资料提取后,采用MetaD isc软件进行Meta分析.结果共纳入8项关于D-二聚体对AP患者预后的研究.Meta分析结果显示:D-二聚体对于AP患者严重程度的预测价值合并的敏感度为0.80(95%CI:0.74-0.80),特异度为0.75(95%CI:0.72-0.79),阳性似然比为3.17(95%CI:2.74-3.66),阴性似然比为0.30(95%CI:0.23-0.38),合并的受试者工作特征曲线的曲线下面积为0.8345(诊断比值比=11.47; 95%CI:8.06-16.33),且无显著的异质性(Q=4.57, I2=0.0%, P>0.1).结论 D-二聚体水平升高有助于早期鉴别不同严重程度的AP患者.

Portosplenomesenteric vein thrombosis in patients with early-stage severe acute pancreatitis

AIM To investigate the incidence and risk factors of portosplenomesenteric vein thrombosis(PSMVT) in the early stage of severe acute pancreatitis(SAP).METHODS Patients with SAP in a tertiary care setting from January 2014 to December 2016 were retrospectively reviewed. All contrast-enhanced computed tomography(CT) studies were reassessed and reviewed. Clinical outcome measures were compared between SAP patients with and without PSMVT in the early stage of the disease. Univariate and multivariate logistic regression analyses were sequentially performed to assess potential risk factors for the development of PSMVT in SAP patients. A receiver operating characteristic(ROC) curve was generated for the qualifying independent risk factors.RESULTS Twenty-five of the one hundred and forty(17.86%) SAP patients developed PSMVT 6.19 ± 2.43 d after acute pancreatitis(AP) onset. PSMVT was confirmed by contrast-enhanced CT. Multivariate stepwise logistic regression analyses showed that Balthazar's CT severity index(CTSI) scores [odds ratio(OR): 2.742; 95% confidence interval(CI): 1.664-4.519; P = 0.000], hypoalbuminemia(serum albumin level < 25 g/L)(OR: 32.573; 95%CI: 2.711-391.353; P = 0.006) and gastrointestinal wall thickening(OR: 4.367, 95%CI: 1.218-15.658; P = 0.024) were independent risk factors for PSMVT developed in patients with SAP. The area under the ROC curve for Balthazar's CTSI scores was 0.777(P = 0.000), the sensitivity was 52%, and the specificity was 93% at a cut-off value of 5.5.CONCLUSION High Balthazar's CTSI scores, hypoalbuminemia and gastrointestinal wall thickening are independent risk factors for PSMVT developed in the early stage of SAP.

Causes associated with recurrent choledocholithiasis following therapeutic endoscopic retrograde cholangiopancreatography: A large sample sized retrospective study

BACKGROUND Recurrence of primary choledocholithiasis commonly occurs after complete removal of stones by therapeutic endoscopic retrograde cholangiopancreatography(ERCP). The potential causes of the recurrence of choledocholithiasis after ERCP are unclear.AIM To analyze the potential causes of the recurrence of choledocholithiasis after ERCP.METHODS The ERCP database of our medical center for the period between January 2007 and January 2016 was retrospectively reviewed, and information regarding eligible patients who had choledocholithiasis recurrence was collected. A 1:1 case-control study was performed for this investigation. Data including general characteristics of the patients, past medical history, ERCP-related factors,common bile duct(CBD)-related factors, laboratory indicators, and treatment was analyzed by univariate and multivariate logistic regression analysis and KaplanMeier analysisly.RESULTS First recurrence of choledocholithiasis occurred in 477 patients; among these patients, the second and several instance(≥ 3 times) recurrence rates were 19.5%and 44.07%, respectively. The average time to first choledocholithiasis recurrence was 21.65 mo. A total of 477 patients who did not have recurrence were selected as a control group. Multivariate logistic regression analysis showed that age > 65 years(odds ratio [OR] = 1.556; P = 0.018), combined history of choledocholithotomy(OR = 2.458; P < 0.01), endoscopic papillary balloon dilation(OR = 5.679; P = 0.000), endoscopic sphincterotomy(OR = 3.463; P = 0.000), CBD stent implantation(OR = 5.780; P = 0.000), multiple ERCP procedures(≥2; OR =2.75; P = 0.000), stones in the intrahepatic bile duct(OR = 2.308; P = 0.000),periampullary diverticula(OR = 1.627; P < 0.01), choledocholithiasis diameter ≥10 mm(OR = 1.599; P < 0.01), bile duct-duodenal fistula(OR = 2.69; P < 0.05),combined biliary tract infections(OR = 1.057; P < 0.01), and no preoperative antibiotic use(OR = 0.528; P < 0.01) were independent risk factors for the recurrence of choledocholithiasis after ERCP.CONCLUSION Patient age greater than 65 years is an independent risk factor for the development of recurrent choledocholithiasis following ERCP, as is history of biliary surgeries, measures during ERCP, and prevention of postoperative complications.

A proposed NMR solution for multi-phase flow fluid detection

In the petroleum industry,detection of multi-phase fluid flow is very important in both surface and down-hole measurements.Accurate measurement of high rate of water or gas multi-phase flow has always been an academic and industrial focus.NMR is an efficient and accurate technique for the detection of fluids;it is widely used in the determination of fluid compositions and properties.This paper is aimed to quantitatively detect multi-phase flow in oil and gas wells and pipelines and to propose an innovative method for online nuclear magnetic resonance(NMR)detection.The online NMR data acquisition,processing and interpretation methods are proposed to fill the blank of traditional methods.A full-bore straight tube design without pressure drop,a Halbach magnet structure design with zero magnetic leakage outside the probe,a separate antenna structure design without flowing effects on NMR measurement and automatic control technology will achieve unattended operation.Through the innovation of this work,the application of NMR for the real-time and quantitative detection of multi-phase flow in oil and gas wells and pipelines can be implemented.

NMR fluid analyzer applying to petroleum industry

Tremendous progress of developing nuclear magnetic resonance(NMR)fluid analyzer has been witnessed in the oil industry for last two decades.This device allows extensive and accurate exploration of fluid properties,such as its hydrogen content,composition,viscosity,hydrogen index(HI),mud filtrate invasion,gas to oil ratio,average velocity,velocity distribution etc.,in the situations of in situ downhole or surface Petro-pipelines.In this review article,we focus on the design principle,manufacturing,implementation,methodology and applications of NMR fluid analyzer to oil and gas industry.A detailed description of the state-of-art NMR fluid analyzers was firstly given to exhibit their respective characteristics.With these experiences on hand,we introduced a series of NMR fluid analyzers designed by us at China University of Petroleum-Beijing with continuous optimizations,in terms of magnet construction,antenna layout,circuit design and operating surroundings.These systems discussed in this article have been demonstrated to achieve multiple NMR parameter acquisition when the fluid is in stationary or flowing state.In the end,a prototype was fabricated and validated considering a vast of engineering influences,such as variable temperatures in a large range,high pressure,limited volume,detection efficiency,etc.A particular emphasis of this paper is to expedite the measurement efficiency of the NMR fluid analyzer to reduce the operation costs.This dilemma can be Figured out by upgrading both pulse sequence and observational mode.For different fluid states,two rapid pulse sequences were proposed to sufficiently obtain the multi-dimensional NMR correlation map.Meanwhile,two observational modes were developed to take full advantage of the polarization time,during which the individual antenna was systematically switched.Another domain of interest in this review concerns the applications of this new tool.For stationary fluids case,accurate identification of fluid properties is of great value for scheme building in oil and gas exploration process.Particularly,it can acquire the fluid content by different NMR responses of different components.In addition,with Bloembergen theory and Stokes-Einstein equation,not only molecular dynamics and composition,but also oil viscosity can be readily evaluated.Moreover,HI information of crude oils will be speculated through partial least square regression.As for flowing fluids case,velocity is a significant parameter to understand the in situ fluid exploitation and therefore evaluate the productivity of certain oil wells or pipelines.Regarding to the unique magnet and antenna designs in our NMR fluid analyzer;this review adopts two distinct methods to obtain flow velocity at a wide rating scale.The first one is a time-of-flight method adaptive in a homogeneous magnetic field,which is suitable in the case of fluid at high flow velocity.The other one relies on the adjacent echo phase difference at a magnetic field with constant gradient,which is preferred for relatively low flow velocity.In the near future,this tool will be tested underground to offer individual fluid velocities by combining both the stationary and flowing analysis methods.

Covalent modification of multiwalled carbon nanotubes with a low molecular weight chitosan

Covalent modification of shortened multiwalled carbon nanombes （MWNTs） with a natural low molecular weight chitosan （LMCS） was accomplished by the nucleophilic substitution reaction. The LMCS modified MWNTs （MWNT-LMCS） were characterized by FTIR, solid-state ^13C NMR, and XPS spectroscopies, thermogravimetric analysis, and transmission electron microscopy. The results revealed that amino and primary hydroxyl groups of the LMCS participated mainly in the formation of the MWNT-LMCS conjugates. The MWNT-LMCS consists of 58 wt.% LMCS, and about four molecular chains of the LMCS were attached to 1000 carbon atoms of the nanotube sidewalls. As a novel derivative of the MWNTs, the MWNT-LMCS not only solved in DMF, DMAc and DMSO, but also in aqueous acetic acid solution.

Hydroiodic Acid Additive Enhanced the Performance and Stability of PbS-QDs Solar Cells via Suppressing Hydroxyl Ligand

The recent emerging progress of quantum dot ink(QD-ink)has overcome the complexity of multiple-step colloidal QD(CQD)film preparation and pronouncedly promoted the device performance.However,the detrimental hydroxyl(OH)ligands induced from synthesis procedure have not been completely removed.Here,a halide ligand additive strategy was devised to optimize QD-ink process.It simultaneously reduced sub-bandgap states and converted them into iodide-passivated surface,which increase carrier mobility of the QDs films and achieve thicker absorber with improved performances.The corresponding power conversion efficiency of this optimized device reached 10.78%.(The control device was 9.56%.)Therefore,this stratege can support as a candidate strategy to solve the QD original limitation caused by hydroxyl ligands,which is also compatible with other CQD-based optoelectronic devices.

Joint Power and Duty-Cycle Design Using Alternating Optimization Algorithm under Energy Harvesting Architectures

In the emerging sixth generation(6G)communication network,energy harvesting(EH)is a promising technology to achieve the unlimited energy supply and hence makes the wireless communication systems self-sustainable in terms of energy.However,in practice,the efficiency of energy harvesting is often low due to the limited device capability.In this paper,we formulate three types of different EH architectures,i.e.,the harvest-use architecture,the harvest-store-use architecture,and the harvest-use-store architecture from the perspective of energy storage efficiency.We propose resource allocation schemes to jointly design the sensor power and duty-cycle via an alternating optimization algorithm under the above EH architectures,in both simultaneous and non-simultaneous harvesting and utilization models,aiming at achieving a higher throughput and energy efficiency.Non-ideal circuit power is also considered.Numerical results show that our proposed schemes under EH architectures outperform the existing classic continuous transmission schemes.

基于主成分分析法去屏蔽的地层尖灭线识别技术及应用——以塔河油田678区不整合面T50屏蔽为例

地层尖灭线的识别与刻画对地层尖灭圈闭的描述极为重要。塔河油田石炭系卡拉沙依组地层尖灭线埋深较大,地震反射层能量较弱,分辨率较低,上覆不整合面T50的强反射隐蔽了地层尖灭线的有效反射信号,使地层尖灭位置很难准确判断。利用主成分分析法去不整合面T50的强屏蔽,使尖灭点信息在地震剖面上更加清晰,从而获得地层尖灭线较精确的位置,使沿其发育的一批地层圈闭边界刻画的更加精确,为地层圈闭类油藏储量的准确计算打下坚实基础。

Study on Chronic Diseases Comprehensive Intervention in Baoji of Shaanxi Province in China

Background: There is very limited data available about the epidemiology trial on chronic diseases comprehensive intervention. The aim of this study was to assess the effect of comprehensive intervention on chronic diseases in Baoji and provide basis for the improvement of chronic diseases intervention measures. Methods: Using four stages stratified random sampling method, comprehensive intervention measures were implemented on intervention group (575 individuals) respectively aimed at three crowds of whole population, high risk population and chronic diseases patients. The control group (782 individuals) did not receive special treatment. Two groups were evaluated effect after one year observation. Results: The chronic diseases prevalence rate of whole population in intervention group was lower than that in control group (P < 0.05), the blood pressure level and smoking proportion of high risk population in intervention group were lower than in control group (P < 0.05), and the blood pressure, blood glucose control rate of chronic diseases patients in intervention group were higher than in control group (P < 0.05). Conclusion: Comprehensive intervention could prevent the rise of chronic diseases prevalence. The intervention is effective in reducing or halting risk factors of high risk population, particularly in controlling blood pressure, blood glucose of patients. We should establish government leading, department cooperation, social participation, longtime and classified comprehensive intervention mechanism of chronic diseases. We believe that whole population should control the risk factors, high risk population should early diagnosis and treatment, chronic diseases patients should normalized management, and it could be applied in other counties.

Heteronuclear-filtered ^(1)H homonuclear multi-quantum correlation experiment at 100 kHz magic-angle spinning Dedicated to Professor Chaohui Ye on the occasion of his 80th birthday

Remarkable advances in fast magic-angle spinning(MAS)techniques significantly improve the resolution of^(1)H solid-state nuclear magnetic resonance(NMR)spectra.Here,we introduce a heteronuclear-filtered^(1)H homonuclear multi-quantum(MQ)correlation strategy available at a MAS rate of 100 kHz by combining^(1)H{X}heteronuclear-filtered methods and^(1)H homonuclear MQ correlation experiments.The proposed strategy was applied to selectively extract^(1)H signals of aluminum lactate(Al-Lac)in a mixture of Al-Lac and zinc lactate(Zn-Lac)using 27Al-filtered methods(i.e.,^(1)H{27Al}heteronuclear multiple quantum correlation(HMQC)or^(1)H{27Al}symmetry-based resonance-echo saturationpulse double-resonance(S-RESPDOR)).We demonstrate that incorporating these 27Al-filtered methods into two-dimensional(2D)^(1)He^(1)H double-quantum(DQ)/single-quantum(SQ),triple-quantum(TQ)/SQ,and even three-dimensional(3D)27Al/^(1)H(DQ)/^(1)H(SQ)experiments can facilitate the acquisition of spectra without signal overlap and targeted characterization of the^(1)H species surrounding 27Al sites.The proposed strategy is considered to efficiently extract key structural information from complex spin systems.

Visual Exploration of Polynomial Combination Based on Variant Measurement Model

Based on the variant measurement model, this paper uses the combined transformation method to convert the binomial coefficients into a polynomial combination counting formula which contains quaternary variables. The two-dimensional quantitative counting matrix is obtained by using the combination function calculation method. Then the related numerical calculation results are converted into statistical histograms and project them on the coordinate axes. The visualization of the final polynomial combination formula is presented in a two-dimensional color map mode. It can be seen from the variant maps of the polynomial that the graphical results under multiple conditions exhibit spatial symmetry, as well as special changes and fixed characteristics of the points.

Preface to the Special Issue “Celebrating the 80th Birthday of Professor Chaohui Ye”

It’s hard to imagine the unlimitedness of human life until you see it with your own eyes.Professor Chaohui Ye demonstrates to us how unlimited and meaningful a life can be,by maximizing his talents and efforts in every position.He is such a gentleman,a great scientist,an encouraging supervisor,an insightful research group leader and a profound thinker,who inspired and influenced so many,including the authors and guest editors of this special issue.

Introduction

Professor Chaohui Ye is one of the founders and pioneers of nuclear magnetic resonance(NMR)spectroscopy and magnetic resonance imaging(MRI)in China.He has achieved much fruitful research in the field of NMR spectroscopy,such as relaxation mechanism in solids,high-resolution solid-state NMR techniques,dynamic nuclear polarization,spin dynamics,the measurement of fundamental solid-state NMR parameters,Raman magnetic resonance,radiation damping,and the design and manufacture of magnetic resonance instrument.Besides NMR,Professor Ye was also engaged in the research of atomic frequency standard and made contributions to the design of the first Rb atomic clock in China.Professor Ye has once been the director of the Wuhan Institute of Physics and Mathematics,Chinese Academy of Sciences(CAS),the president of the Wuhan branch of CAS,the director of the State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics,the director of the National Center for Magnetic Resonance in Wuhan,the director of the Committee of Magnetic Resonance Spectroscopy,Chinese Physical Society,and the editor-in-chief of Chinese Journal of Magnetic Resonance.For many years,Professor Ye has made tremendous efforts for the development of NMR and MRI research,and domestic academic journals.