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简介:AbstractBackground:Radical nephrectomy and thrombectomy is the standard surgical procedure for the treatment of renal cell carcinoma (RCC) with tumor thrombus (TT). But the estimation of intra-operative blood loss is only based on the surgeon’s experience. Therefore, our study aimed to develop Peking University Third Hospital score (PKUTH score) for the prediction of intra-operative blood loss volume in radical nephrectomy and thrombectomy.Methods:The clinical data of 153 cases of renal mass with renal vein (RV) or inferior vena cava tumor thrombus admitted to Department of Urology, Peking University Third Hospital from January 2015 to May 2018 were retrospectively analyzed. The total amount of blood loss during operation is equal to the amount of blood sucked out by the aspirator plus the amount of blood in the blood-soaked gauze. Univariate linear analysis was used to analyze risk factors for intra-operative blood loss, then significant factors were included in subsequent multivariable linear regression analysis.Results:The final multivariable model included the following three factors: open operative approach (P < 0.001), Neves classification IV (P < 0.001), inferior vena cava resection (P = 0.001). The PKUTH score (0-3) was calculated according to the number of aforementioned risk factors. A significant increase of blood loss was noticed along with higher risk score. The estimated median blood loss from PKUTH score 0 to 3 was 280 mL (interquartile range [IQR] 100-600 mL), 1250 mL (IQR 575-2700 mL), 2000 mL (IQR 1250-2900 mL), and 5000 mL (IQR 4250-8000 mL), respectively. Meanwhile, the higher PKUTH score was, the more chance of post-operative complications (P = 0.004) occurred. A tendency but not significant overall survival difference was found between PKUTH risk score 0 vs. 1 to 3 (P = 0.098).Conclusion:We present a structured and quantitative scoring system, PKUTH score, to predict intra-operative blood loss volume in radical nephrectomy and thrombectomy.
简介:摘要机床参考点(原点或零点),是机床的机械原点和电气原点相重合的点。每台机床可以有一个参考原点,也可以按需要设置多个参考原点,如用于自动刀具交换(ATC)或自动拖盘交换(APC)等。机械原点是基本机械坐标系的基准点,机械部件一旦装配完毕,机械原点随即确立。电气原点是以机床检测反馈元件发出的栅点信号或零标志信号确立的参考点。为了使电气原点与机械原点重合,必须将电气原点到机械原点的距离用一个原点偏移量参数进行设置。这个重合的点就是机床原点。在加工中心使用过程中,机床手动或者自动回参考点操作是经常进行的动作。本文对THMC机床出现的126#报警Z轴不在原点故障诊断分析,做出了相应的诊断方案,最终找到故障点,更换或维修磁栅尺,并提出了应急方案,避免了设备长时间停机,使机床得以正常运行,保障了生产。
简介:Icewatercontent(IWC)playsimportantrolesinweatherandclimatechange.DeterminingtheIWCsofcirruscloudswithmillimeter-wavelengthradarcanbeproblematicduetoinfluencesoficeparticlerotationontheirbackscatteringcrosssections.Wehereintroducemodelstodescribetheradiationpatternsofsixnonsphericalparticlesofspecificsizes.SimulationsusingHFSSsoftwarewereappliedtodescribethedifferencesresultingfromdifferentorientationsandequivalentspheres.Adoubleexponentialfunctionwasusedforfittingtodescribetherelationshipbetweentheparticles’maximumsizesandbackscatteringcrosssections.Thebackscatteringcrosssectionsofnonsphericaliceparticleswerecomputedbythemethodofmoment,andthoseoftheequivalentsphericalparticleswerecomputedbyLorenz-Mietheoryforthreedifferentorientations:fixed,horizontal,andrandom.AssumingthatamixtureofnonsphericaliceparticlesfollowstheB-Hmixingmodel,thesizedistributionofcirrusparticlesobeystheexponentialdistributionmeasuredbyNASAin2007.BycomputingtheIWCsofcirrusclouds,whichfollowstheabovementionedB-Hmodelandexponentialdistribution,theradarreflectivityfactorsofnonsphericaliceparticlesandequivalentspheresatthreedifferentorientationscanbecomputed.Subsequently,theIWCresultscanbeacquiredbyinputtingtheradarreflectivityvariablesintothewell-knownIWC-Zformula.TheanalysisdescribedheredemonstratesthatwhenusingtheradarreflectivityZ,theorientationmustbeconsideredinordertodeterminetheIWC.Usingequivalentspheretheory,thederivedIWCsunderestimatetheactualIWCs.Theseresultsareimportantforaccuratelyretrievingthemicrophysicalparametersofcirrusclouds.
简介:摘要光伏发电的并网是现如今太阳能光伏发电发展研究的热点,而其中逆变器作为DC-AC的重要部件在光伏并网发电当中起到了重要的作用,由于现有的电压型逆变器以及电流型逆变器在原理上并不能满足我们的实际要求,因此,本论文运用了一种新型的Z源逆变器,它能够克服电压型以及电流型逆变器在这里的局限性,主要体现在逆变器和主电路之间的直通并利用这个使他成为一个既能升压又能降压的逆变器。本论文在深层分析了Z源逆变器的电路结构以及工作原理重点分析了Z源逆变器工作在电压模式的工作,对于电压型Z源逆变器的电路参数进行了分析,研究了基于Z源逆变器的光伏并网控制方案并选取了合适方案解决问题。
简介:InthisnotewediscusstheannihilatingpropertiesofsequencesoverZ/(m).Byconsideringthelinearcomplexityandtheannihilatorstructure,wederivetheuniquenessconditionfortheminimalpolynomial,andsomerelatedresultsofdecimationsequences.