基于改进LightGBM算法的配网线损自动检测方法

常规线损检测方法主要对线损率数据的短期波动性进行分析,线损产生的突变情况直接影响了检测的精准度,导致线损检测效果不佳,因此,研究基于改进LightGBM算法的配网线损自动检测方法。根据线损率数据长期波动性变化,提取出配网线损趋势分量,再检测出线损趋势分量的突变节点,分析线损突变对检测结果的干扰特性。通过改进LightGBM算法,构建出线损自动检测模型,在模型上加入一个深度限制,提高模型的运行效率,进而实现配网线损的快速检测。采用对比实验的方式,验证了该方法能够在模型中自动提取突变节点,自动检测精准度更高,能够应用于实际生活中。

Ultrasound features of extranodal extension in the metastatic cervical lymph nodes of papillary thyroid cancer:a case-control study

Objective：Extranodal extension in cervical lymph nodes is an important risk factor for the progression and prognosis of papillary thyroid cancer.The purpose of this study was to identify the common and characteristic preoperative ultrasonography features that are associated with the pathologic extranodal extension of metastatic papillary thyroid carcinoma.Methods：We retrospectively assessed and compared clinicopathologic and ultrasound features between 60 papillary thyroid cancer patients with extranodal extension and 120 control patients with papillary thyroid cancer without extranodal extension.Results：With respect to the pathological N stage and clinicopathologic features,N1b stage papillary thyroid carcinomas were more frequently found in patients who were extranodal extension-positive,in comparison with those who were extranodal extension-negative（78.3%vs.63.3%,P=0.043）.Extranodal extension was detected most frequently in level VI cervical lymph nodes（48.7%）.In our univariate analysis of patients with papillary thyroid carcinoma,cervical lymph nodes with extranodal extension showed higher incidences of node matting,microcalcification,cystic area,aspect ratio＆lt;2,and larger diameter than those without extranodal extension（all P〈0.05）.Our multivariate analysis demonstrated that node matting and cystic area were independent risk factors for the presence of extranodal extension[odds ratio（OR）：4.751,95%confidence interval（CI）：1.212~18.626,P=0.025;OR：2.707,95%CI：1.127~6.502,P=0.026].Conclusions：Common ultrasound features may indicate the presence of extranodal extension in patients with metastatic cervical lymph nodes of papillary thyroid carcinoma.

DELETIONS AND POINT MUTATIONS OF p16,p15 GENE IN PRIMARY TUMORS AND TUMOR CELL LINES

Aberrations of chromosome 9 p21 22 are involved in the genesis of many forms of cancer.The gene p16 and p15 have been assigned to this region.Both p16 and p15 are an inhibitor of cyclin D cdk4,cyclin D cdk6 complex and have been implicated in a wide variety of cancer types,including the germline of patients with familial melanoma.In order to investigate and compare the status of p16,p15 gene in primary tumors and cell lines,we examined 357 primary tumors and 29 cell lines derived from diverse tumor types.In addition to analysis of these primary tumors and cell lines,blood specimens from 91 patients either with sporadic multiple cancers or from cancer prone families were also analyzed.The data showed the following:1)Homozygous deletions of p16,p15 were comparatively rare and far less common than previously reported,although hemizygous deletions were observed in a significant fraction of many tumor types;2)the incidence of p16,p15 deletions(either homozygous deletions or heterozygous deletions)varied significantly among different tumor types;3)most deletions involved in both p16 and p15 genes;4)sequence variations in the coding sequence of p16,p15 were comparatively rare among these tumor types,though mutations and polymorphisms were identified;5)some tumors which showed LOH at 9p,containing p16 and p15 gene,did not show deletions or point mutations in the p16,p15 gene.6)In a subset of retinoblastoma and osteosarcoma where no Rb gene mutations were present a significant fraction was found to contain p16,p15 gene deletions.