基于Focal Loss改进LightGBM的供水管网毛刺数据检测

针对数据不平衡导致的管网毛刺数据检测召回率偏低问题,提出一种Focal Loss改进LightGBM的管网毛刺数据检测方法。首先,结合管网毛刺数据的特点,针对性构造邻域相关特征。其次,将Focal Loss函数引入LightGBM,提高模型对难以检测的毛刺样本的权重,并对Focal Loss不同的参数取值进行实验,以平衡精确率与召回率。最后,选择不同参数的Focal Loss进行模型融合,进一步提升模型对不平衡毛刺数据的检测性能。在某市供水管网的真实数据上进行实验,结果表明,对比基于交叉熵损失函数的单一模型,本文提出的Focal Loss改进后的融合模型在毛刺数据上召回率和F1值的提升幅度达33.3和18个百分点,但毛刺数据的精确率还有待进一步提升。本文所提方法从损失函数入手,动态调整难易样本的权重,有效地提升了不平衡数据下的毛刺数据的检测性能。

正常小鼠血清通过抑制focal adhesion信号通路减轻小鼠放射性肺炎

目的探讨正常小鼠血清(NMS)对放射性肺炎的治疗作用及可能机制。方法建立胸腔照射诱导的放射性肺炎模型,将小鼠分为对照组、静脉注射血清组、照射组和照射后静脉注射血清组。注射血清组小鼠在照射后立即静脉注射正常小鼠血清100μL,对照组小鼠注射100μL生理盐水,隔天注射1次,共注射8次。照射后15 d取材,HE染色检测肺组织形态学变化,ELISA检测小鼠肺组织和血清中炎症因子肿瘤坏死因子-α(TNF-α)、转化生长因子-β(TGF-β)、白细胞介素-1α(IL-1α)、白细胞介素-6(IL-6)水平;流式细胞术检测肺组织内淋巴细胞比例变化。外泌体miRNA高通量测序探索处理后小鼠的信号通路变化,qRT-PCR检测免疫相关基因的表达水平,使用Western blotting检测黏着斑通路talin-1、tensin 2、FAK、vinculin、α-actinin和paxillin蛋白的表达。结果与照射组相比,照射后注射血清组小鼠肺脏器系数、血清及肺组织上清液中炎症因子TNF-α、TGF-β、IL-1α、IL-6水平显著降低(P<0.05),CD45^(+)、CD4^(+)、T_(reg)淋巴细胞在小鼠肺组织中的浸润程度显著下降(P<0.05);肺中Egfr和Pik3cd的mRNA和蛋白表达水平显著下调,talin-1、tensin 2、FAK、vinculin、α-actinin和paxillin蛋白的表达水平也显著降低(P<0.05)。结论正常小鼠血清通过抑制focal adhesion信号通路关键蛋白的表达减轻电离辐射诱发的小鼠放射性肺炎。

Constraint on the focal mechanism of the 2011 Tohoku earthquake from the radial modes

Different from other normal modes of the Earth’s free oscillation that depend on all the six components(M_(rr),M_(tt),M_(pp),M_(rt),M_(rp),and M_(tp))of the centroid moment tensor,the amplitudes of the radial modes depend on the M_(rr)component(e.g.,scalar moment(M_(0)),dip(δ),and slip(λ))and hypocenter depth of the focal mechanism,and hence can be easily used to constrain these parameters of the focal mechanism.In this study,we use the superconducting gravimeter(SG)records after the 2011 Tohoku earthquake to analyze the radial modes_(0)S_(0)and_(1)S_(0).Based on the solutions of the focal mechanism provided by the GCMT and USGS,we can obtain the theoretical amplitudes of these two radial modes.Comparing the theoretical amplitudes with the observation amplitudes,it is found that there are obvious differences between the former and the latter,which means that the GCMT and USGS focal mechanisms cannot well represent the real focal mechanism of the 2011 event.Taking the GCMT solution as a reference and changing the depth and the three parameters of the M_(rr)moment,the scalar moment(M_(0))and the dip(δ)have significant influences,but the effects of the slip(λ)and the depth are minor.After comparisons,we provide a new constraint(M_(0)=5.8±0.09×10^(22)N·m,δ=10.1±0.08°,λ=88°,and depth=20 km)for the focal mechanism of the 2011 event.In addition,we further determine the center frequency(1.631567±2.6e^(-6)mHz)and quality factor(2046.4±50.1)of the_(1)S_(0)mode.

Focal incidental colorectal fluorodeoxyglucose uptake:Should it be spotlighted?

Fluorine-18 fluorodeoxyglucose(F-18 FDG)positron emission tomography/computed tomography(PET/CT)has emerged as a cornerstone in cancer evaluation imaging,with a well-established history spanning several years.This imaging modality,encompassing the examination of the body from the base of the skull to the upper thighs,comprehensively covers the chest and abdominopelvic regions in a singular scan,allowing for a holistic assessment of nearly the entire body,including areas of marginal interest.The inherent advantage of this expansive scan range lies in its potential to unveil unexpected incidental abnormal hypermetabolic areas.The identification of incidental focal FDG uptake within colorectal regions during PET/CT scans is not an uncommon occurrence,albeit fraught with challenges associated with non-specific FDG uptake.The presence of benign colorectal lesions or physiological uptake poses a particular obstacle,as these may manifest with FDG uptake levels that mimic malignancy.Consequently,physicians are confronted with a diagnostic dilemma when encountering abnormal FDG uptake in unexpected colorectal areas.Existing studies have presented divergent results concerning these uptakes.Standardized uptake value and its derivatives have served as pivotal metrics in quantifying FDG uptake in PET images.In this article,we aim to succinctly explore the distinctive characteristics of FDG,delve into imaging findings,and elucidate the clinical significance of incidental focal colorectal uptake.This discussion aims to contribute valuable insights into the nuanced interpretation of such findings,fostering a comprehensive understanding.

Unexpected focal fluorodeoxyglucose uptake in main organs;pass through or pass by?

Since the inception of fluorine-18 fluorodeoxyglucose(F-18 FDG),positron emission tomography/computed tomography(PET/CT)utilizing F-18 FDG has become widely accepted as a valuable imaging modality in the field of oncology,with global prevalence in clinical practice.Given that a single Torso PET/CT scan encompasses the anatomical region from the skull base to the upper thigh,the detection of incidental abnormal focal hypermetabolism in areas of limited clinical interest is both feasible and not uncommon.Numerous investigations have been undertaken to delineate the distinctive features of these findings,yet the outcomes have proven inconclusive.The incongruent results of these studies present a challenge for physicians,leaving them uncertain about the appropriate course of action.This article provides a succinct overview of the characteristics of fluorodeoxyglucose,followed by a comprehensive discussion of the imaging findings and clinical significance associated with incidental focal abnormal F-18 FDG activity in several representative organs.In conclusion,while the prevalence of unrecognized malignancy varies across organs,malignancies account for a substantial proportion,ranging from approximately one-third to over half,of incidental focal uptake.In light of these rates,physicians are urged to exercise vigilance in not disregarding unexpected uptake,facilitating more assured clinical decisions,and advocating for further active evaluation.

Design and fabrication of compound varifocal lens driven by polydimethylsiloxane film elastic deformation

A compound varifocal lens based on electromagnetic drive technology is designed and fabricated, where the polydimethylsiloxane(PDMS) film acts as a driving component, while the PDMS biconvex lens and the plane-concave lens form a coaxial compound lens system. The plane-concave lens equipped with driving coils is installed directly above the PDMS lens surrounded by the annular magnet. When different currents are applied, the annular magnet moves up and down, driving the PDMS film to undergo elastic deformation, and then resulting in longitudinal movement of the PDMS lens. The position change of the PDMS lens changes the focal length of the compound lens system. To verify the feasibility and practicability of this design, a prototype of our compound lens system is fabricated in experiment. Our proposed compound lens shows that its zoom ability reaches 9.28 mm when the current ranges from -0.20 A to 0.21 A.

A monolithic integrated medium wave Mercury Cadmium Telluride polarimetric focal plane array

A medium wave(MW)640×512(25μm)Mercury Cadmium Telluride(HgCdTe)polarimetric focal plane array(FPA)was demonstrated.The micro-polarizer array(MPA)has been carefully designed in terms of line grating structure optimization and crosstalk suppression.A monolithic fabrication process with low damage was explored,which was verified to be compatible well with HgCdTe devices.After monolithic integration of MPA,NETD<9.5 mK was still maintained.Furthermore,to figure out the underlying mechanism that dominat⁃ed the extinction ratio(ER),specialized MPA layouts were designed,and the crosstalk was experimentally vali⁃dated as the major source that impacted ER.By expanding opaque regions at pixel edges to 4μm,crosstalk rates from adjacent pixels could be effectively reduced to approximately 2%,and promising ERs ranging from 17.32 to 27.41 were implemented.

Carcinoembryonic antigen in the diagnosis,treatment,and follow-up of focal liver lesions

In this editorial review,we comment on the article published in the recent issue of the World Journal of Gastrointestinal Surgery.Carcinoembryonic antigen(CEA)is a fetal glycoprotein and can be secreted in very small amounts from healthy adults after birth.CEA is widely used not only for diagnostic tumor markers but also importantly for the management of some gastrointestinal tumors.The most common clinical use is surveillance for the monitoring of colorectal carcinoma.However,CEA can become elevated in several malign or benign characterized pathologies.Serum CEA level may vary depending on the location of the lesion,whether it metastasizes or not,and its histopathological characteristics.It has been determined that cases with high preoperative CEA have a more aggressive course and the risk of metastasis to the lymph tissue and liver increases.In this editorial review,we focused on evaluating the role of CEA in clinical practice with a holistic approach,including the diagnostic and prognostic significance of CEA in patients with focal liver lesions,the role of CEA in follow-up after definitive surgery,and also hepatic resection for metastasis,and the management of all patients with raised CEA.

Towards fast focal mechanism inversion of shallow crustal earthquakes in the Chinese mainland

We have developed an automatic regional focal mechanism inversion system based on the Earthquake Rapid Report(ERR) system and the real-time three-component seismic waveform stream of 1 000 broadband seismic stations provided by the China Earthquake Networks Center(CENC). The system can rapidly provide a double couple solution and centroid depth within 5–15 min after receiving earthquake information from the ERR system.The data processing is triggered by earthquake information obtained from the ERR system. The system is capable of determining the focal mechanism of all shallow-depth earthquakes in the Chinese mainland with a magnitude of 5.5–6.5. It utilizes waveform data recorded by seismic stations located within 500 km from the epicenter,enabling the reporting of a focal mechanism solution within 5–15 min of an earthquake occurrence. Additionally,the system can assign a corresponding grade(A B C) to the focal mechanism solution. We processed a total of 301earthquakes that occurred from 2021 to June 2022, and after the quality control, 166 of them were selected.These selected solutions were manually checked, and 160 of them were compiled in a focal mechanism catalog.This catalog can be conveniently downloaded online via the Internet. The automatic focal mechanism solution of earthquakes in eastern China exhibits a good agreement with that provided by the Global Centroid Moment Tensor(GCMT), when available. The average Kagan angle between this catalog and GCMT is 22°, and the average difference in MWis 0.17. Furthermore, compared with GCMT, the minimum magnitude of our catalog has been reduced from approximately 5.0 to 4.0. The correlation between the centroid depth and crustal thickness in the Chinese mainland confirms the distribution of the centroid depth.

Imaging features and management of focal liver lesions

Notably,the number of incidentally detected focal liver lesions(FLLs)has increa-sed dramatically in recent years due to the increased use of radiological imaging.The diagnosis of FLLs can be made through a well-documented medical history,physical examination,laboratory tests,and appropriate imaging methods.Although benign FLLs are more common than malignant ones in adults,even in patients with primary malignancy,accurate diagnosis of incidental FLLs is of utmost clinical significance.In clinical practice,FLLs are frequently evaluated non-invasively using ultrasound(US),computed tomography(CT),and magnetic resonance imaging(MRI).Although US is a cost-effective and widely used imaging method,its diagnostic specificity and sensitivity for FLL characterization are limited.FLLs are primarily characterized by obtaining enhancement patterns through dynamic contrast-enhanced CT and MRI.MRI is a problem-solving method with high specificity and sensitivity,commonly used for the evaluation of FLLs that cannot be characterized by US or CT.Recent technical advancements in MRI,along with the use of hepatobiliary-specific MRI contrast agents,have significantly improved the success of FLL characterization and reduced unnece-ssary biopsies.The American College of Radiology(ACR)appropriateness criteria are evidence-based recommendations intended to assist clinicians in selecting the optimal imaging or treatment option for their patients.ACR Appropriateness Criteria Liver Lesion-Initial Characterization guideline provides recommend-ations for the imaging methods that should be used for the characterization of incidentally detected FLLs in various clinical scenarios.The American College of Gastroenterology(ACG)Clinical Guideline offers evidence-based recommend-ations for both the diagnosis and management of FLL.American Association for the Study of Liver Diseases(AASLD)Practice Guidance provides an approach to the diagnosis and management of patients with hepatocellular carcinoma.In this article,FLLs are reviewed with a comprehensive analysis of ACR Appropri-ateness Criteria,ACG Clinical Guideline,AASLD Practice Guidance,and current medical literature from peer-reviewed journals.The article includes a discussion of imaging methods used for the assessment of FLL,current recommended imaging techniques,innovations in liver imaging,contrast agents,imaging features of common nonmetastatic benign and malignant FLL,as well as current management recommendations.

Review of plasma exchange and rituximab for prevention of recurrent focal segmental glomerulosclerosis after a prior graft loss

BACKGROUND Focal segmental glomerulosclerosis(FSGS)often recurs after transplantation,leading to graft dysfunction and graft loss.Patients who have lost prior grafts due to recurrence are at particularly high risk of re-recurrence in subsequent grafts.Rituximab and plasma exchange have been used pre-emptively to prevent post-transplant recurrence.However,the efficacy of such preventative measures remains unclear.AIM To investigate the outcomes of preventative rituximab and plasma exchange for recurrent FSGS in transplant recipients after prior graft loss.METHODS We conducted a systematic review of 11 studies with 32 patients who had experienced prior graft loss due to post-transplant FSGS recurrence and were treated with either pre-emptive plasma exchange alone,rituximab alone,or a combination of both.RESULTS Overall,47%of the 32 patients experienced recurrence despite prophylactic treatment.Re-recurrence was seen in 25%(1/4)with pre-emptive rituximab alone,and 45%recurrence(9/20)with plasma exchange alone.Re-recurrence was noted in 63%with the use of combined plasma exchange and rituximab.CONCLUSION There is a paucity of available evidence in the literature to draw clear conclusions on the benefits of pre-emptive measures to prevent FSGS re-recurrence.The small sample sizes and variations in protocols call for larger and controlled studies to serve this patient population at high risk of recurrence and graft loss.

Clinicopathological features and medium-term outcomes of histologic variants of primary focal segmental glomerulosclerosis in adults:A retrospective study

BACKGROUND The Columbia classification identified five histological variants of focal segmental glomerulosclerosis(FSGS).The prognostic significance of these variants remains controversial.AIM To evaluate the relative frequency,clinicopathologic characteristics,and medium-term outcomes of FSGS variants at a single center in Pakistan.METHODS This retrospective study was conducted at the Department of Nephrology,Sindh Institute of Urology and Transplantation,Karachi,Pakistan on all consecutive adults(≥16 years)with biopsy-proven primary FSGS from January 1995 to December 2017.Studied subjects were treated with steroids as a first-line therapy.The response rates,doubling of serum creatinine,and kidney failure(KF)with replacement therapy were compared between histological variants using ANOVA or Kruskal Wallis,and Chi-square tests as appropriate.Data were analyzed by SPSS version 22.0.P-value≤0.05 was considered significant.RESULTS A total of 401 patients were diagnosed with primary FSGS during the study period.Among these,352(87.7%)had a designated histological variant.The not otherwise specified(NOS)variant was the commonest,being found in 185(53.9%)patients,followed by the tip variant in 100(29.1%)patients.Collapsing(COL),cellular(CEL),and perihilar(PHI)variants were seen in 58(16.9%),6(1.5%),and 3(0.7%)patients,respectively.CEL and PHI variants were excluded from further analysis due to small patient numbers.The mean follow-up period was 36.5±29.2 months.Regarding response rates of variants,patients with TIP lesions achieved remission more frequently(59.5%)than patients with NOS(41.8%)and COL(24.52%)variants(P<0.001).The hazard ratio of complete response among patients with the COL variant was 0.163[95%confidence interval(CI):0.039-0.67]as compared to patients with NOS.The TIP variant showed a hazard ratio of 2.5(95%CI:1.61-3.89)for complete remission compared to the NOS variant.Overall,progressive KF was observed more frequently in patients with the COL variant,43.4%(P<0.001).Among these,24.53%of patients required kidney replacement therapy(P<0.001).The hazard ratio of doubling of serum creatinine among patients with the COL variant was 14.57(95%CI:1.87-113.49)as compared to patients with the TIP variant.CONCLUSION In conclusion,histological variants of FSGS are predictive of response to treatment with immunosuppressants and progressive KF in adults in our setup.

Endoscopic ultrasound-guided tissue acquisition for the diagnosis of focal liver lesion

In patients with liver tumors,the histopathology examination can assist in diagnosis,staging,prognosis,and therapeutic management strategy.Endoscopic ultrasound(EUS)-guided tissue acquisition using fine needle aspiration(FNA)or more newly fine needle biopsy(FNB)is a well-developed technique in order to evaluate and differentiate the liver masses.The goal of the EUS-FNA or EUS-FNB is to provide an accurate sample for a histopathology examination.Therefore,malignant tumors such as hepatocarcinoma,cholangiocarcinoma and liver metastasis or benign tumors such as liver adenoma,focal hyperplastic nodular tumors and cystic lesions can be accurately diagnosed using EUS-guided tissue acquisition.EUS-FNB using 19 or 22 Ga needle provide longer samples and a higher diagnostic accuracy in patients with liver masses when compared with EUS-FNA.Few data are available on the diagnostic accuracy of EUS-FNB when compared with percutaneously,ultrasound,computer tomography or transjugulary-guided liver biopsies.This review will discuss the EUS-guided tissue acquisition options in patients with liver tumors and its efficacy and safety in providing accurate samples.The results of the last studies comparing EUS-guided liver biopsy with other conventional techniques are presented.The EUS-guided tissue acquisition using FNB can be a suitable technique in suspected liver lesions in order to provide an accurate histopathology diagnosis,especially for those who require endoscopy.

Clinical course and outcome of adult patients with primary focal segmental glomerulosclerosis with kidney function loss on presentation

BACKGROUND Kidney function loss or renal insufficiency indicated by elevated creatinine levels and/or an estimated glomerular filtration rate(eGFR)<60 mL/minute/1.73 m²at presentation in patients with primary focal segmental glomerulosclerosis(FSGS)is commonly seen as a poor prognostic marker for kidney survival.However,a pre>vious study from our center suggested this may be due to hemodynamic factors.AIM To observe the clinical and biochemical parameters,treatment response,kidney survival,and overall outcomes of adult patients with primary FSGS presenting with kidney function insufficiency.METHODS This retrospective observational study was conducted at the Department of Nephrology,Sindh Institute of Urology and Transplantation,Karachi,Pakistan,from January 1995 to December 2017.During this period,401 biopsy-proven primary FSGS patients were identified,of which 98(24.4%)presented with kidney function loss or renal insufficiency defined as eGFR<60 mL/minute/1.73 m²at presentation and were studied in detail.RESULTS Among the 98 patients with renal function loss on presentation,the mean age was 30.9 years±13.6 years with a male-to-female ratio of 2.5:1.The mean serum creatinine level was 2.2 mg/dL±1.3 mg/dL and mean eGFR 37.1 mL/minute/1.73 m2±12.8 mL/minute/1.73 m2.The mean 24-hour urinary protein excretion was 5.9 g/day±4.0 g/day,and the mean serum albumin was 2.1 g/dL±1.0 g/dL(median:1.5 g/dL).The mean systolic blood pressure(BP)was 132.7 mmHg±19.8 mmHg,and the mean diastolic BP was 87.4 mmHg±12.7 mmHg.Steroid treatment was given to 81(82.6%)of 98 patients for an average duration of 19.9 weeks±14.4 weeks,with a mean total steroid dose of 4.4 g±1.5 g.Treatment response showed that 20(24.6%)patients achieved complete remission,9(11.1%)achieved partial remission,and 52(64.1%)did not respond.The baseline eGFR was significantly lower in the non-responsive group(P=0.006).The distribution of FSGS variants was also significantly different among steroid-responsive and non-responsive groups(P=0.012).CONCLUSION Renal function loss in FSGS patients at presentation does not necessarily indicate irreversible kidney function loss and a significant number of patients respond to appropriate treatment of the underlying disease.

一种改进的Focal Loss在语义分割上的应用

传统基于深度学习的语义分割方法使用的损失函数为交叉熵,而交叉熵并不能解决训练数据中的样本非均衡性问题。语义分割任务属于像素级分类,样本的非均衡性问题在其中体现得十分突出。文章提出了一种改进的Focal Loss作为损失函数来自动解决训练样本的非均衡性。该损失函数等同于在标准交叉熵上加上一个权重,该权重能够自动增加困难样本的交叉熵损失值,同时保持简单样本的交叉熵损失值。将Focal Loss作为DeepLabv3+的损失函数,并将DeepLabv3+的Backbone替换为ResNet-18,再使用Cityscapes数据集作为训练样本,分别使用交叉熵和Focal Loss作为损失函数来对模型进行训练。实验结果表明,改进的Focal Loss损失函数相比于交叉熵获得的语义分割精度更高,且能够有效缓解训练样本的非均衡性问题。

基于边界自适应SMOTE和Focal Loss函数改进LightGBM的信用风险预测模型

针对信用风险评估中数据集不平衡影响模型预测效果的问题,提出一种基于边界自适应合成少数类过采样方法(BA-SMOTE)和利用FocalLoss函数改进LightGBM损失函数的算法(FLLightGBM)相结合的信用风险预测模型。首先,在边界合成少数类过采样(Borderline-SMOTE)的基础上,引入自适应思想和新的插值方式,使每个处于边界的少数类样本生成不同数量的新样本,并且新样本的位置更靠近原少数类样本,以此来平衡数据集;其次,利用FocalLoss函数来改进LightGBM算法的损失函数,并以改进的算法训练新的数据集以得到最终结合BA-SMOTE方法和FLLightGBM算法建立的BA-SMOTE-FLLightGBM模型;最后,在LendingClub数据集上进行信用风险预测。实验结果表明,与其他不平衡分类算法RUSBoost、CUSBoost、KSMOTE-AdaBoost和AK-SMOTE-Catboost相比,所建立的模型在G-mean和AUC两个指标上都有明显的提升,提升了9.0%~31.3%和5.0%~14.1%。以上结果验证了所提出的模型在信用风险评估中具有更好的违约预测效果。

Focal mechanism solution statistics of seismic tsunami sources

In recent years, tsunami happens frequently in the world, which caused huge losses. In order to find objective features of tsunamigenic source, global CMT data from 1976 to 2010 and tsunami data from NOAA are analyzed statistically, tsunami is compared with bigger tsunamis. At last, some features of seismic tsunami sources are concluded.

The Focalizers and the Themes of the Sound and the Fury

Based on the narrative theory of Shlomith Rimmon-Kenan,the present paper will analyze the close connection between the choice and order of the focalizers and the themes of the novel to show that they are chosen and arranged deliberately and accorded to its themes.

Computer Simulation of Compensation Method for Infrared Focal Plane Array

A major motivation for this work is to investigate a method of computer simulation for compensating fixed pattern noise of the infrared focal plane arrays. A mathematical model of the output signal of focal plane array was established; a compensating algorithm utilizing reference source was derived and simulating programs were designed. The images of compensating process verify the influence of nonuniformity of responsibility and offset on fixed pattern noise. The result show that simulating method of investigating compensation technology for focal plane arrays is feasible, the generated images and methods can be used to the study of image recognition.

Protective Effect of Tetrandrine and Fructose-1,6-diphos phate on the Model of Focal Cerebral Ischemia in Rats

The effect of tetrandrine (Tet) on the infarction area and volume of rat brain induced by middle cerebral artery occlusion (MCAO) was investigated. The treatment with Tet 7.5, 12.0 or 15.0 mg·kg 1 , or with fructose 1,6 diphosphate (FDP) 200 and 350 mg·kg 1 ip immediately after MCAO, respectively, significantly reduced the infarction area and volume in a dose dependent manner. MK801 and FDP also displayed a protective effect on brain ischemia. A combination of Tet and FDP administered immediately after MCAO, produced a more potent protective effect than those treated with Tet or FDP alone. When Tet or FDP was administered 1 h and 2 h after MCAO, respectively, they could still significantly reduce the infarction area and volume of brain tissue. But, there was no significant protective effect when these two compounds were given 3 h after MCAO.