3D MERGE与3D SPACE STIR序列在腰椎间盘突出症检查中的应用比较

目的:对比三维多回波恢复梯度回波(3D MERGE)、三维可变反转角快速自旋回波(3D SPACE STIR)序列在腰椎间盘突出症(LDH)检查中的应用效果。方法:选择2020年1月~2022年11月收治的135例LDH患者,回顾性分析患者临床和磁共振成像(MRI)资料,所有患者均接受常规MRI扫描及3D MERGE、3D SPACE STIR序列扫描,对比3D MERGE、3D SPACE STIR序列测量神经根直径的一致性,评价两种序列的图像质量参数[信噪比(SNR)、对比噪声比(CNR)]、图像清晰度评分。结果:3D MERGE和3D SPACE STIR序列测量的L3~S1神经根直径比较差异无统计学意义(P>0.05),且两组序列测量的L3、L4、L5和S1直径均显示出较高相关性(r=0.957,0.986,0.975,0.972,P<0.05);3D MERGE序列的SNR及CNR均高于3D SPACE STIR序列,神经根显示分级、图像清晰度评分优于3D SPACE STIR序列,差异有统计学意义(P<0.05)。结论:3D MERGE、3D SPACE STIR序列在LDH神经根直径测量中具有极高一致性,3D MERGE序列较3D SPACE STIR序列能够更清晰显示神经跟的解剖形态,图像质量更好。

中医药多元证据整合方法学MERGE框架

在循证医学时代下,依托规范的技术方法和标准化的操作规程发掘中医药独特优势,是实现中医药现代化、国际化发展并惠泽人类的必由之路。中医理论、人用经验和研究证据三结合证据体系的提出标志着中医药特色评价体系思维方法取得了重要进步,经过恰当方法整合后的多元证据体是中医药临床指南推荐意见和循证卫生决策的有力支撑。本文基于当前国际证据合成与分级方法学前沿进展,初步提出中医药多元证据整合的方法学框架——MERGE(Merge Evidence-based Research and artificial intelliGence to support smart dEcision)框架,以期为中医药循证医学方法学体系的完善和发展提供借鉴和参考。

MRI 3D-MERGE序列对三角纤维软骨复合体损伤的诊断价值

目的探讨MRI三维-多回波恢复梯度回波(three dimensional-multiple-echo recalled gradient echo,3D-MERGE)序列在腕关节三角纤维软骨复合体(triangular fib roc a rt ilage complex,TFCC)损伤中的诊断价值。方法回顾性分析四川省骨科医院2021年1月-2022年1月因腕尺侧疼痛就诊的76例患者的临床资料,其中男性35例,女性41例,年龄16-52岁,平均年龄39.6岁。所有患者行腕关节MRI 3D-MERGE序列检查,并在随后接受腕关节镜手术。将TFCC损伤分为中心型损伤和边缘型损伤。以腕关节镜结果为金标准,探讨分析MRI 3D-MERGE序列诊断TFCC损伤的敏感度、特异度。结果腕关节镜检查确诊TFCC损伤者60例,其中中心型16例,边缘型28例,中心型和边缘型损伤同时存在16例;MRI 3D-MERGE序列检查TFCC损伤70例,中心型13例,边缘型35例,22例同时存在中心型和边缘型损伤。对比得出MRI 3D-MERGE序列诊断TFCC损伤中心型损伤的敏感度、特异度分别为0.93、0.89,边缘型损伤的敏感度、特异度分别为0.80、0.62。结论MRI3D-MERGE序列对TFCC损伤有较高的诊断价值,但相对于中心型损伤,MRI 3D-MERGE序列对边缘型损伤显示较低的特异度,因此在临床中,对于MRI提示的边缘型损伤患者,医师还需结合患者临床病史和体格检查进行谨慎诊断。

A New Merged Product Reveals Precipitation Features over Drylands in China

Due to the considerable uncertainties inherent in the datasets describing the spatiotemporal distributions of precipitation in the drylands of China,this study presents a new merged monthly precipitation product with a spatial resolution of approximately 0.2°×0.2°during 1980–2019.The newly developed precipitation product was validated at different temporal scales(e.g.,monthly,seasonally,and annually).The results show that the new product consistently aligns with the spatiotemporal distributions reported by the Chinese Meteorological Administration Land Data Assimilation System(CLDAS)product and Multi-Source Weighted Ensemble Precipitation(MSWEP).The merged product exhibits exceptional quality in describing the drylands of China,with a bias of–2.19 mm month^(–1)relative to MSWEP.In addition,the annual trend of the merged product(0.09 mm month^(–1)yr^(−1))also closely aligns with that of the MSWEP(0.11 mm month^(–1)yr^(−1))during 1980–2019.The increasing trend indicates that the water cycle and wetting process intensified in the drylands of China during this period.In particular,there was an increase in wetting during the period from 2001–2019.Generally,the merged product exhibits potential value for improving our understanding of the climate and water cycle in the drylands of China.

xStripeMerge:基于纠删码存储的高效宽条带生成方法

为了解决纠删码存储系统的已有宽条带生成方法中扩容方案将产生大量宽条带生成带宽,合并方案受限于双条带的问题,提出了一种针对多条带合并下的宽条带生成问题的高效宽条带生成方法。定义了多条带合并过程的2个关键算子,并将宽条带生成问题建模为组合优化问题,提出了优先寻找具有小的奇偶校验块传输成本的窄条带组合方案的高效宽条带生成方法xStripeMerge。实验结果表明,与目前最优的存储扩容方法相比,xStripeMerge可以减少75%宽条带生成带宽。xStripeMerge的时间和空间复杂度远优于扩展的双条带合并方法,xStripeMerge可以在更短的时间内获得与其性能相近的宽条带生成方案,并且xStripeMerge可以适用于大规模存储系统。

基于VVC的多方向细化Merge模式优化算法

针对多功能视频编码标准VVC帧间预测中,Merge模式未充分考虑运动存在的多种方向性从而降低了预测精度的问题,提出了一种基于VVC的多方向细化Merge模式优化算法。本算法在分析带运动矢量差的Merge技术的基础上,首先调整了步长选择范围并增加多种搜索方向,然后根据步长自适应选择色度块的运动补偿方式,并最终根据率失真代价准则选择最优的运动矢量信息。实验结果表明,本文算法与VTM-12.0参考模型相比,在低延迟P帧配置下Y、U、V三分量的BD-rate分别平均下降了0.57%、0.62%、0.25%,在随机接入配置下的BD-rate中Y分量下降了0.27%、U分量仅提高了0.11%、V分量降低了0.04%,有效地提升了Merge模式的编码性能。

Carto-Merge技术在左肺静脉共干伴阵发性房颤患者导管消融术中的应用

目的探讨Carto-Merge技术指导存在左肺静脉共干的阵发性房颤患者行导管消融术的临床效果。方法选择存在左肺静脉共干的阵发性房颤患者27例,随机分为A组13例与B组14例。B组在Carto3技术建立的电解剖标测(FAM)模型指导下进行双侧肺静脉导管消融术,A组在Carto-Merge技术建立的影像融合模型(术前CT三维图像融合Carto3系统指引下建立的FAM模型)指导下进行双侧肺静脉导管消融术。记录并比较A组FAM模型与CT三维图像、B组FAM模型的左肺静脉相关参数(上下径、前后径、开口面积)及左心房容积,比较两组消融环相关参数(消融环上下径、前后径、横截面积、上下径比值、前后径比值及消融环横截面积/左肺静脉开口面积)。两组术后随访6个月,记录消融结局相关指标(双侧肺静脉电隔离完成情况、左右肺静脉消融时间及肺动脉压增高、窦性心律维持情况)。结果A组CT三维图像的左肺静脉开口面积、左心房容积均小于FAM模型(P均<0.05),两组FAM模型的左肺静脉上下径、前后径、开口面积及左心房容积比较差异均无统计学意义(P均>0.05)。A组消融环前后径、横截面积、前后径比值、消融环横截面积/左肺静脉开口面积均大于B组(P均<0.05)。两组消融环上下径、上下径比值及左、右肺静脉消融时间比较差异均无统计学意义(P均>0.05)。两组均顺利完成双侧肺静脉电隔离,其肺动脉压增高率、窦性心律维持率比较差异均无统计学意义(P均>0.05)。结论采用Carto-Merge技术指导存在左肺静脉共干的阵发性房颤患者进行导管消融术时不会增加手术时间,其消融效果与传统Carto3技术相当且安全性较高,有助于复杂肺静脉解剖结构的识别和消融。

Validation of the multi-satellite merged sea surface salinity in the South China Sea

Sea surface salinity(SSS)is an essential variable of ocean dynamics and climate research.The Soil Moisture and Ocean Salinity(SMOS),Aquarius,and Soil Moisture Active Passive(SMAP)satellite missions all provide SSS measurements.The European Space Agency(ESA)Climate Change Initiative Sea Surface Salinity(CCI-SSS)project merged these three satellite SSS data to produce CCI L4SSS products.We validated the accuracy of the four satellite products(CCI,SMOS,Aquarius,and SMAP)using in-situ gridded data and Argo floats in the South China Sea(SCS).Compared with in-situ gridded data,it shows that the CCI achieved the best performance(RMSD:0.365)on monthly time scales.The RMSD of SMOS,Aquarius,and SMAP(SMOS:0.389;Aquarius:0.409;SMAP:0.391)are close,and the SMOS takes a slight advantage in contrast with Aquarius and SMAP.Large discrepancies can be found near the coastline and in the shelf seas.Meanwhile,CCI with lower RMSD(0.295)perform better than single satellite data(SMOS:0.517;SMAP:0.297)on weekly time scales compared with Argo floats.Overall,the merged CCI have the smallest RMSD among the four satellite products in the SCS on both weekly time scales and monthly time scales,which illustrates the improved accuracy of merged CCI compared with the individual satellite data.

Novel layout design of 4H-SiC merged PiN Schottky diodes leading to improved surge robustness

A method to improve the surge current capability of silicon carbide(SiC)merged PiN Schottky(MPS)diodes is presented and investigated via three-dimensional electro-thermal simulations.When compared with a conventional MPS diode,the proposed structure has a more uniform current distribution during bipolar conduction due to the help of the continuous P+surface,which can avoid the formation of local hotspots during the surge process.The Silvaco simulation results show that the proposed structure has a 20.29%higher surge capability and a 15.06%higher surge energy compared with a conventional MPS diode.The bipolar on-state voltage of the proposed structure is 4.69 V,which is 56.29%lower than that of a conventional MPS diode,enabling the device to enter the bipolar mode earlier during the surge process.Furthermore,the proposed structure can suppress the occurrence of‘snapback'phenomena when switching from the unipolar to the bipolar operation mode.In addition,an analysis of the surge process of MPS diodes is carried out in detail.

一种改进的Split-Merge图像分割算法

图像分割的经典算法Split-Merge算法思路简洁、运算效率高,但存在边界定位不准确和过分割等问题。针对过分割问题提出了一种改进的Split-Merge算法,在合并过程中引入全局目标函数,并在目标函数中定义了长度项,使用贪心法完成合并过程。长度项以及贪心法的使用促使相邻区域充分合并,有效地克服了过分割等问题,取得了较好的分割效果。

高效视频编码的Merge模式候选决策研究与改进

高效视频编码的Merge模式基于四叉树的图像编码方式,可以将多个相邻且具有相似运动情况的预测单元(PU)块合并成同一个区域并使用相同的运动参数。研究候选PU的合并决策过程,针对Merge模式所带来的高计算复杂度且合并候选过程中常进行多次不必要的判断问题,提出一种低复杂度的候选决策算法。该算法基于时空域候选在不同情形下的分布特征,从改变候选列表选择过程的角度减少候选判断次数从而降低编码复杂度。实验结果表明,与原始算法相比,该算法的编码时间缩短、码率减少,能有效降低编码复杂度。

Construction and Evaluation of Merged Pharmacophore Based on Peroxisome Proliferator Receptor-Alpha Agonists

Pharmacophore is a commonly used method for molecular simulation, including ligand-based pharmacophore （LBP） and structure-based pharmacophore （SBP）. LBP can be utilized to identify active compounds usual with lower accuracy, and SBP is able to use for distin- guishing active compounds from inactive compounds with frequently higher missing rates. Merged pharmacophore （MP） is presented to integrate advantages and avoid shortcomings of LBP and SBP. In this work, LBP and SBP models were constructed for the study of per- oxisome proliferator receptor-alpha （PPARα） agonists. According to the comparison of the two types of pharmacophore models, mainly and secondarily pharmacological features were identified. The weight and tolerance values of these pharmacological features were adjusted to construct MP models by single-factor explorations and orthogonal experimental design based on SBP model. Then, the reliability and screening efficiency of the best MP model were validated by three databases. The best MP model was utilized to compute PPARα activity of compounds from traditional Chinese medicine. The screening efficiency of MP model outperformed individual LBP or SBP model for PPARα agonists, and was similar to combinatorial screening of LBP and SBP. However, MP model might have an advantage over the combination of LBP and SBP in evaluating the activity of compounds and avoiding the inconsistent prediction of LBP and SBP, which would be beneficial to guide drug design and optimization.

Capacity model of on-rampmerging section of urban expressway

To establish the empirical capacity model of an on- ramp merging section, the Erlang distribution is first selected to define the time headway distribution, and then the gap acceptance theory is applied to develop the basic capacity model of the on-ramp merging section. Since not all the time headways on the shoulder lane can be made full use of by on- ramp vehicles, a modified capacity model is developed, which takes the usage probability of time headway into consideration. Then, a model of capacity discount coefficient ~： is developed. Finally, based on the modified capacity model and the model of capacity discount coefficient, an empirical merge capacity model which contains the shoulder lane volume, critical gap, and the distance from nose to merging point, is constructed. Results show that, compared with other models, the proposed model is more reasonable since it takes merging section geometry into consideration, and it is easy to apply. The merge capacity varies with the shoulder lane volume, the critical gap, the distance between the nose and the merging point, and the design velocity of the shoulder lane and ramp.

Carto-Merge指导下导管消融治疗阵发性房颤的初步体会

目的运用16排螺旋CT图像与CARTO三维电解剖标测整合技术（Carto-Merge）指导阵发性房颤的导管消融治疗。方法32例经抗心律失常药物治疗效果欠佳的患者进行手术，其中6例患者术前1～3d行16排CT心脏成像检查，术前将CT导入有Carto-Merge的软件包进行三维重建，重建后在Carto-Merge指导手术。结果所有患者均顺利完成手术，未发生手术并发症。Carto-Merge整合误差为（1．8±0．62）mm，使用Carto-Merge患者平均手术时间为（98±28）min，X线曝光时间为（26±11）min；未使用Carto-Merge患者手术时间为（112±42）min，X线曝光时间为（35±17）min。结论使用图像融合技术可以缩短手术及X线曝光时间，提高手术的效率及安全性。

改进Split-Merge分割用于蝗虫图像

为了更好地分割蝗虫图像,对传统Split-Merge算法做出改进:用PCNN来进行分裂,采用一种简化的Mumford-Shah模型进行合并。该方法的优点是:分裂阶段不仅无效分割数目减少,而且无方块效应,对边缘定位准确;合并阶段能够理想地将分裂后的区域合并为感兴趣的前景与不感兴趣的背景,误合并与欠合并大幅减小。实验对成虫与幼虫图像均进行分割。综合比较,该算法性能较优。

3D-MERGE序列在肩袖及其周围韧带损伤中的诊断价值

目的:评价核磁共振3D-MERGE序列对肩袖及其周围韧带损伤的临床应用价值。方法:回顾性分析20例肩关节活动受限,临床症状疑诊肩袖损伤的病人,行常规肩关节磁共振扫描和3D-MERGE序列扫描,对比观察各条肌腱、韧带,探讨这个新序列诊断肩袖损伤的价值。结果:3D-MERGE序列能沿任意方位重建肩关节各个位置,清晰显示各条肌腱、韧带及软骨,较常规序列更有优势。且扫描时间明显缩短,病人容易耐受。结论:3D-MERGE序列能较准确的对肩袖及周围韧带的损伤做出诊断,更好的为临床医师提供科学依据。

基于PCNN的改进Split-merge图像分割

为了更好地分割图像,对传统Split-merge算法作出改进:PCNN先进行分裂,用一种简化的Mumford-Shah模型进行合并,使得分裂阶段不仅无效分割减少,而且无方块效应,对边缘定位准确;合并阶段能够理想地将分裂后的区域合并为感兴趣的前景与不感兴趣的背景,误合并与欠合并大幅减小。对Papav,Monkey,Twoman图像的仿真表明,其分割结果和运行时间均优于AMS,MBMS算法。仿真结果证明,本文算法是一种适用于图像分割的有效算法。

在Split-Merge框架下进行基于图的图像分割

Split-Merge算法是图像分割领域的经典算法,思路简洁、运算效率高,但因分裂位置和形状固定,导致出现方块效应和边界定位不准确等问题。现有的各种改进算法不能从根本上解决这些问题,为此本文将基于图的分割算法纳入到Split-Merge框架中来,提出了在Split-Merge框架下进行基于图的分割。新算法把传统的基于图割值的算法作为分裂阶段的处理手段,在合并阶段采用本文提出的一种与访问次序无关的合并算法。新算法既解决了Split-Merge算法中因分裂位置和形状固定而带来的各种问题,也有效地消除了在基于图的分割中常见的"过分割"现象,取得了满意的分割效果。

基于Excel数据源的Mail Merge在教学管理中的应用

教育教学管理过程中常常涉及到追考证、成绩单、录取通知书等教育对象数据的通知工作,利用常规办法将成绩统计表中数据逐一复制的方式不仅繁琐且容易出错。基于EXCEL数据源的Mail Merge(Word邮件合并)使用可以迅速、准确地完成数据处理、个案分析及个人成绩通知。

Cluster-Merge本体构造算法

本体构造就是利用各种数据源以半自动方式新建或扩充改编已有本体以构建一个新本体。现有的本体构造方法大都以大量领域文本和背景语料库为基础抽取大量概念术语,然后从中选出领域概念构造出一个本体。Cluster-Merge算法首先对领域文档先用k-means聚类算法进行聚类,然后根据文档聚类的结果来构造本体,最后根据本体相似度进行本体合并得到最终的输出本体。通过实验可证明用Cluster-Merge算法得出的本体可以提高查全率、查准率。