The Application Value of Swan-Neck Microcatheter in Peripheral Vascular Interventional Therapy

Background and Objectives: Establishing a stable pathway is the basis for interventional surgery, and hyper-selected intubation has become the basic requirement for vascular intervention therapy. Super-selection intubation can not only significantly improve the efficacy of peripheral intervention treatment, but also greatly reduce surgical complications. However, during the treatment of peripheral vascular intervention (such as liver tumor arterial chemotherapy embolism, hemoptysis bronchial arterial embolism, gastrointestinal hemorrhagic gastrointestinal arterial embolism, etc.), vascular mutation is often large, and there are many branches, and the direction of blood flow is into the direction of blood flow, the horns are even reverse, and even the use of straight-headed microstructures will have difficulty interpolation difficulties or even failure, which increases the risk of surgery and affects safety treatment. To overcome this, pre-plasticized microcatheters have emerged, among which the InstantPass Swan-Neck Microstructure is a catheter with a head-end morphology similar to Cobra. Our research aims to explore the feasibility, safety, and technical advantages of the use of swan-neck microcatheter in peripheral vascular hyperboloid intubation. Materials and Methods: From January 2023 to March 2024, 31 patients with swan-neck microstructure were used in the peripheral vascular intervention therapy outside the hospital. Among them, there were 23 men and 8 women, aged 32 - 81 years old, an average (55 ± 13) years, and the average irradiation time was 35.1 ± 24.7 minutes. 10 cases of iodide oil arterial chemotherapy embolism, 7 cases of microspheres of hepatic arteries, 3 cases of gastric duodenal artery selective embolism, 3 cases of vein embolism with esophageal stomach, and 2 cases of sperm varicose vein embolism, 2 cases of selective embolism of the intestinal membrane, 2 cases of uterine arteries embolism, and 2 cases of renal arterial embolism. 11 of these patients switched to the swan-neck microstructure after using the straight-headed microstructure super-selective intubation. To analyze whether the swan-neck microcatheter is successfully transported to the target location, whether it can provide a satisfactory path for subsequent intravascular treatment, evaluate the surgery instant image results and complications related to the microstructure during the surgery period, analyze the angle of the target blood vessels and the main blood vessels, the target blood vessels, the target blood vessels, the relationship between the degree of pedestrian and the success rate of ultra-selective intubation, and summarize the indication of the application of the swan-neck microstructure in peripheral intervention therapy. Results: In this study, 31 patients used 31 swan-neck microcatheters, of which 22 (70.9%) target vascular and main blood vessels were ≤90˚;17 patients (54.8%) patients were curved and angulated;11 cases (35.5%) were after the failure of the superselective intubation of the straight-headed microstructure, the swan-neck microcatheter was successful after the failure;1 case (3.2%) patients with microstructure-related mezzanine occurred during surgery, and the complication rate of the perioperative ductation was 3.2%. All target lesions are finally successfully completed, and the success rate of surgical technology is 100%. Conclusion: Swan-neck microcatheters have a high success rate in superselective cannulation of peripheral blood vessels and perform well in vascular tortuosity and angulated lesions.

基于SWAN模型下的马拉博油罐区深水波浪条件分析

在深水波浪条件下,油罐区的稳定性和安全性都面临着极大的挑战,对所在海域的风与波浪耦合作用的波浪分析变得至关重要。本文基于第三代海浪数值模型SWAN,依据CCMP和CFSR数值风场资料,建立南大西洋海浪后报数据集。通过与尼日利亚拉格斯外海Bonga站和纳米比亚卡拉斯外海Kudu站的实测数据资料进行对比,验证了数据集的合理性。并对赤道几内亚马拉博外海深水波浪条件进行分析,为后续油罐区项目建设提供数据参考。

基于SWAN模型的海宁市尖山段海塘设计波浪要素研究

为了保障尖山段海塘综合整治提升工程顺利实施,采用三重嵌套的SWAN波浪数学模型,研究整治工程实施前、后的海塘塘前波浪场变化。研究表明:海塘西侧由于高程抬升,水深减少,波高也相应减少,但强浪向依然不变;海塘东侧高程基本不变,波高也无明显变化;工程实施后的消浪效果在11%~17%;将数值模型结果与规范中的莆田公式比较,基于工程实际安全考虑,采用波浪数值模型计算结果作为设计波浪要素,为整治工程实施提供数据支撑。

SWAN序列在胎儿脊柱形态学诊断中的应用研究

针对目前有关胎儿脊柱形态变化的情况,就其诊断的相关方法进行分析,提出了利用SWAN序列法,对胎儿脊柱形态学进行研究。方法 于2019年1月至2021年11月,98名孕妇(孕21-36周)行胎儿脊柱磁共振检查,在胎儿脊柱椎体骨性发育异常的诊断中,超声检查是常用的检查方法。然而,在某些情况下,超声检查不能明确诊断,这时需要使用其他影像学检查方法。SWAN序列是一种较新的MRI影像学检查方法,可以检测胎儿脊柱椎体骨性发育异常。本次研究对28例胎儿进行了SWAN序列回顾性分析,并以出生后随访结果为金标准进行了对比。结果显示,SWAN序列的诊断准确性分别为半椎体畸形47.5%、蝴蝶椎畸形20%、椎体冠状裂畸形32.5%。因此,SWAN序列在超声检查不能明确诊断时,可以显著提高胎儿脊柱椎体骨性发育畸形的检出率。这一研究结果为胎儿脊柱椎体骨性发育异常的诊断提供了新的思路和方法。

Modeling wave attenuation by vegetation with accompanying currents in SWAN

Coastal wetlands such as salt marshes and mangroves provide important protection against stormy waves.Accurate assessments of wetlands’capacity in wave attenuation are required to safely utilize their protection services.Recent studies have shown that tidal currents have a significant impact on wetlands’wave attenuation capacity,but such impact has been rarely considered in numerical models,which may lead to overestimation of wave attenuation in wetlands.This study modified the SWAN(Simulating Waves Nearshore)model to account for the effect of accompanying currents on vegetation-induced wave dissipation.Furthermore,this model was extended to include automatically derived vegetation drag coefficients,spatially varying vegetation height,and Doppler Effect in combined current-wave flows.Model evaluation against an analytical model and flume data shows that the modified model can accurately simulate wave height change in combined current-wave flows.Subsequently,we applied the new model to a mangrove wetland on Hailing Island in China with a special focus on the effect of currents on wave dissipation.It is found that the currents can either increase or decrease wave attenuation depending on the ratio of current velocity to the amplitude of the horizontal wave orbital velocity,which is in good agreement with field observations.Lastly,we used Hailing Island site as an example to simulate wave attenuation by vegetation under hypothetical storm surge conditions.Model results indicate that when currents are 0.08–0.15 m/s and the incident wave height is 0.75–0.90 m,wetlands’wave attenuation capacity can be reduced by nearly 10%compared with pure wave conditions,which provides implications for critical design conditions for coastal safety.The obtained results and the developed model are valuable for the design and implementation of wetland-based coastal defense.The code of the developed model has been made open source,in the hope to assist further research and coastal management.

SWAN模式中风输入方案对南海台风浪后报的影响分析

基于近岸海浪模式(SWAN,Simulating waves nearshore),分别用ERA(ECMWF re-analysis)5、ERA-Interim、CCMP(Cross calibrated multi-platform)及美国国家环境预报中心(NCEP,National centers for environmental prediction)数据中心的天气预报再分析系统(CFSR,Climate forecast system reanalysis)的海表面10 m处风场作为不同的驱动风场,模拟15次经过南海的热带气旋过程产生的极值波高情况下的海浪,比较了不同风场驱动的海浪后报模拟值与Jason卫星高度计实测值的误差;再应用模拟精度最高的驱动风场,模拟同样条件的海浪场,对拖曳系数的参数化方案进行敏感性分析和比较。结果表明:在模式输入参数为默认值的情况下,ERA5风场与WU方案的风输入组合能够获得更加准确的中国南海热带气旋发生海域的有效波高;最后基于以上结果构建30年的南海海域海浪要素数据集,并使用Pearson-Ⅲ分布推算出南海海域的多年一遇有效波高。研究结果可以为南海海域的海浪灾害评估与海洋工程建设提供参考。

Migration routes and differences in migration strategies of Whooper Swans between spring and autumn

Long-distance migratory birds travel more rapidly in spring than in autumn,as they face temporal breeding constraints.However,several species travel slower in spring owing to environmental influences,such as food availability and wind conditions.GPS trackers were attached to 17 Whooper Swans(Cygnus cygnus) inhabiting northeastern Mongolia,to determine their migration routes and stopover sites in spring and autumn.Differences between spring and autumn migrations,migration-influencing parameters,and the effect of spring stopover site temperatures were analyzed.Six swans completed perfect tours between their wintering and breeding sites,and these data were used for analysis.Spring migration lasted 57 days,with 49.2 days spent at 3.7 stopover sites.Autumn migration lasted 21.5 days,with 17.5 days spent at 1.0 stopover sites.Thus,the swans traveled more rapidly in autumn than in spring.Migration distance,number of stopovers,migration speed,and straightness were important migration determinants in both spring and autumn.Migration distance,stopover duration,number of stopovers,daily travel speed,travel duration,and migration speed differed significantly between spring and autumn.During spring migration,the temperature at the current stopover sites and that at the future stopover sites displayed significant variations(t=1585.8,df=631.6,p <0.001).These findings are critical for the conservation and management of Whooper Swans and their key habitats in East Asian regions,and the data are anticipated to make a particularly significant contribution toward developing detailed management plans for the conservation of their key habitats.

SWAN浅水波浪模式在渤海的应用研究——Phillips线性增长比例系数的改进

将国际上通用的SWAN波浪数值模式应用到渤海,以检验其适应性。通过对由风引起的波浪的增长和耗散作用源函数的实验研究,发现SWAN中所采用的Phillips线性增长部分的比例系数和波浪成长有较大的关系,此比例系数随摩擦速度变化(原模式取此系数为一常数)。基于模式试验,引入了一个新的Phillips线性增长项公式,并且利用3个风过程对模式的改进进行了验证。3个风过程的计算结果和实测值比较表明,计算结果在3个过程当中都得到了明显的改进。

WaveWatch Ⅲ和SWAN模型嵌套技术在业务化海浪预报系统中的应用及检验

根据钓鱼岛海域海监巡航执法保障预报、重点海洋安全保障目标精细化预报等海浪业务化预报工作的新需求,基于WRF海面风场预报模型,利用结构网格海浪模型Wave WatchⅢ和非结构网格海浪模型SWAN(Simulating Waves Nearshore)的嵌套计算,建立一套适用于东海区和上海近海的海浪数值预报系统。通过不同数值实验,证明此系统的稳定性和时效性。利用观测数据对连续2个月的有效波高值的预报结果进行检验,结果表明:24小时预报平均绝对误差在0.3 m以下;48小时预报平均绝对误差在0.5 m以下;72小时预报平均绝对误差在0.7 m以下,且误差极值主要是由台风过程引起,但预报趋势仍值得参考。对2次台风过程采用不同风场源数据进行对比试验,结果显示采用实况路径的后报风场,海浪预报精度明显改善。对于近岸区域采用嵌套计算的SWAN模型预报结果比Wave Watch III模型预报结果精度显著提高,证明建立的海浪数值预报系统在满足"稳定性"和"时效性"的基础上,各尺度和分辨率的预报产品"准确性"也能得到保证。

利用WAVEWATCH和SWAN嵌套计算珠江口附近海域的风浪场

基于CCMP(Cross Calibrated Multi-platform)卫星遥感海面风场数据,通过将WAVEWATCH和SWAN(SimulatingWAves Nearshore)模型嵌套的方法,数值模拟了珠江口附近海域的风浪场。将总计10个月的数值模拟的有效波高、波周期和波向分别与相应的观测值进行了定量比较。结果说明,有效波高的平均绝对误差为15.4cm,分散系数SI为0.240,相关系数为0.925;波周期的平均绝对误差为1.9s,分散系数SI为0.433,相关系数为0.636;波向的平均绝对误差为23.9°。计算的波高和波向与观测结果的变化趋势相吻合。由于第三代海浪模式本身的缺陷,导致所计算的波周期偏小。总体说来,本文所采用的数值模式能较好地模拟珠江口附近海域的风浪场。另外,还设计了6个算例以探讨采用不同的计算方法和风场对计算结果精度的影响。结果表明使用本文的数值方法和高精度的CCMP风场确实可以提高计算结果的精度。

WAVEWATCH Ⅲ和SWAN模式在南海北部海域海浪模拟结果的对比分析

基于1987年9月到1988年8月期间南海北部的一个浮标资料,首先分析了美国环境预报中心(NCEP)和国家大气研究中心(NCAR)联合推出的再分析风场在南海北部海域的适用性,结果表明NCEP/NCAR再分析风场在一定程度上与浮标观测结果相一致。然后利用NCEP/NCAR再分析风场作为海浪模式输入场,评估了WAVEWATCHⅢ(WW3)和Simulating Waves Nearshore(SWAN)这2个海浪模式在南海北部海域模拟海浪的能力,结果表明在季风和季风转换期间,WW3模式和SWAN模式对有效波高的模拟能力几乎一致。在季风期间,WW3模式对平均波周期的模拟能力优于SWAN模式;而在季风转换时期,SWAN模式模拟平均波周期的能力较好。此外,还利用WW3模拟结果分析了南海北部海域海浪的空间分布特征,分析结果表明有效波高受季风影响呈显著的季节变化,平均波周期呈现相对显著的半年变化。

基于SWAN的冰雹探测算法研究

为了提高冰雹短时临近预报的准确性,首先介绍了WSR-88D冰雹算法原理,提出了在SWAN中使用垂直高度阈值进行改造的方法,通过和PUP产品数据进行对比,验证了算法的正确性。其次,针对业务中出现的冰雹尺寸计算值过大问题,通过与有冰雹尺寸记录的实例进行比较,使用最佳的幂函数拟合进行了修正。最后,对业务中常见的由超折射引起的虚警进行了分析。结果表明,设定风暴中心附近的反射率垂直梯度阈值>3,可以消除大部分的超折射。对于由冰雹产生的阈值<3的风暴,继续使用二维风暴个数>7的阈值进行识别,可以减少误判率,取得较理想的效果。

浅水波浪数值模型SWAN的原理及应用综述

概述了模拟海岸、河口的浅水波浪数值模型研究现状、存在的问题以及用能量平衡方程预报海浪的发展历史。介绍了基于当代最新波浪理论研究成果的第三代浅水波浪数值模型SWAN模型,对模型的适用性、数值特性、功能及局限性进行了阐述。介绍动谱平衡方程数学模型、方程离散要求、边界条件的处理和源项(包括能量输入、损耗及波与波之间非线性相互作用)的处理方法,重点介绍三相波非线性相互作用。模拟海安湾有效波高、波周期场,并分析波与波之间非线性相互作用对波浪要素预报的影响,最后对SWAN模型的应用前景和研究趋势进行了展望。

基于WRF-SWAN模式的韦帕台风波浪场模拟

为获取更为准确的台风过程波浪模拟结果,将中尺度大气模式WRFD海面以上10 m处风速资料作为驱动风场提供给第三代海浪模式SWAN进行波浪计算,模拟了0713号"韦帕"台风的波浪场过程。模拟和实测资料比较结果表明WRF模式能较好地模拟韦帕台风过程,给SWAN模型提供高精度风场资料,WRF-SWAN模式能够较好模拟韦帕台风过程中海浪的演化和传播。

Wave Watch的操作系统移植及其与SWAN嵌套接口的改进

为使WaveWatch和SWAN两种海浪预报模式能够有效地嵌套运行,将WaveWatch模式从UNIX移植到Windows系统下运行,同时对SWAN模式与WaveWatch模式的嵌套接口格点座标读取精度进行修改,使其能够应用于不规则边界的曲线网格和小间距规则网格的嵌套;作为检验个例,使用WaveWatchIII与SWAN模式多重嵌套的方法在Windows系统下对长江口海浪场进行数值模拟实验,得到了理想的模拟结果。

基于SWAN模式的南海台风浪推算的影响因素分析

基于南海实际地形和真实的台风过程,对影响SWAN模式在南海台风浪推算中的准确性的因素进行了较系统的研究。首先对不同的模型风场进行了对比分析,结果表明一个准确的风场是正确推算台风浪的关键。同时对SWAN模式中的白冠耗散作用、风能输入与白冠耗散不同的组合方式和折射项作用等因素对台风浪推算的影响进行分析,并对模式中的各影响因素给出了合理建议。使得SWAN模式在南海台风浪推算中具有更好的适用性。

基于WRF-SWAN耦合模式的台风“威马逊”波浪场数值模拟

获取高分辨率的风场数据和气压场数据是精确模拟台风浪的基础,采用经验公式构建台风风场和气压场对海浪模式进行驱动,无法反映台风影响下海气动力过程,难以提供高精度的风场、气压场数据。本文基于中尺度大气模式WRF(Weather Research and Forecasting model)和第三代海浪模式SWAN(Simulating WAves Nearshore model),构建了南中国海地区大气—海浪实时双向耦合模式,针对超强台风"威马逊"进行数值模拟。将数值模拟结果与现场观测结果及卫星高度计观测结果进行对比验证,验证结果表明,本文建立的WRF-SWAN耦合模式在对台风"威马逊"影响下的南中国海台风浪的模拟中展现出较高的模拟精度,揭示了台风风场分布和台风浪分布在空间上的"右偏性"不对称分布特征及其形成机制。基于WRF和SWAN建立的大气-海浪实时双向耦合模式能够准确模拟台风动力过程以及台风浪的时空分布特征,可以推广用于南中国海地区台风浪的模拟分析。

SWAN近岸海浪模式在辽东湾的应用

介绍了第三代近岸海浪数值模式SWAN,并使用SWAN对辽东湾海浪进行了模拟。辽东湾平缓的淤泥质海岸为研究海浪底摩擦耗散提供了理想的条件。与实测数据对比分析表明,SWAN模式能够较好的模拟辽东湾近岸水域海浪。在8月南风过程中,底摩擦耗散起作用的范围主要集中于辽东湾北部10m等深线以浅水深变化平缓的地区。耗散强度随水深变浅而逐渐增强。

两种网格下的SWAN模式对黄渤海海浪模拟比较

采用NCEP再分析风场作为驱动海浪模式的强迫场,在考虑相同物理过程和分辨率基础上,SWAN海浪模式分别采用矩形网格和非结构三角网格对2000年12月黄渤海海域波浪场进行模拟,并将模拟的有效波高与海洋浮标观测数据作对比分析,结果表明,SWAN模式运用两种网格均能够取得良好的模拟结果,相对矩形网格,非结构三角网格模拟有效波高效果较好,且能够较好的刻画复杂地形。最后,采用局部加密的非结构三角网格对黄渤海波浪场进行模拟验证,分析表明非结构三角网格的局部加密方案可以进一步提高加密区域的有效波高模拟精度。

WAVEWATCH和SWAN嵌套模拟台风浪场的结果分析

利用WAVEWATCH和SWAN嵌套模拟2007年8月墨西哥湾飓风迪安的波浪场。将QSCAT/NCEP混合风场与台风模型风场合成为背景风场。修改WAVEWATCH和SWAN嵌套接口以使WAVEWATCH和SWAN2种海浪预报模式能够有效地嵌套运行。利用WAVEWATCH和SWAN嵌套模拟飓风迪安的波浪场,采用浮标资料检验模拟结果,以验证WAVEWATCH和SWAN模拟的准确性及修改后嵌套接口的可用性。结果表明,修改嵌套接口之后模式运行平稳,2种模式的结果与浮标及高度计观测数据均基本吻合。嵌套模拟结果好于单纯使用WAVEWATCH模拟的结果,体现了利用2种模式嵌套模拟台风浪场的科学性。