检索结果-南通市图书馆

Generalized principle of least action in electromagnetism and its applications

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1998年第9期43卷 732-734页

作者： Yongjun Xie changhong liang Xidian Univ Dept Microwave Telecommun Engn Xian 710071 Peoples R China

The generalized principle of least action in electromagnetism is presented, which is effective even though in lossy and nonreciprocal media. It is pointed out that the Maxwell’s equations can be derived from this principle. At last for example of its applications, some useful variational expressions for electromagnetic fields are derived systematically from the principle.

关键词： the generalized principle of least action lossy and nonreciprocal media Maxwell’s equations variational expressions.

Generalized system function analysis of resonant behavior of electromagnetic open systems

在线全文

学校读者我要写书评

暂无评论

Science in China(Series F) 2005年第5期48卷 615-631页

作者： LI Long LIU Haixia SHI Yan liang changhong National Laboratory of Antennas and Microwave Technology Xidian University Xi'an 710071 China Institute of Signal and Data Processing Xidian University Xi'an 710071 China

Abstract The generalized system function, H（s）, directly associated with the radiated or scattered fields is presented to effectively analyze the special resonant behavior of electromagnetic open systems in this paper, which is adaptively constructed by using the model-based parameter estimation （MBPE） technique in the complex frequency domain. By analyzing the characteristics of complex zeros, poles and residues of H（s） in a finite operational frequency band, we can effectively determine resonant frequencies and resonant intensity of electromagnetic open systems. It is known that an analysis of Q-factor of antenna and scattering systems has been an interesting and challenging problem. Based on H（s） and the complex frequency w theories, a complex frequency method for Q-factor of electromagnetic open systems is presented in this paper. Some examples of the practical antenna arrays are given to illustrate the applications and validity of the generalized system function theory proposed by this paper.

关键词： Keywords: generalized system function H(s) electromagnetic open resonance complex frequency qualityfactor Q model-based parameter estimation (MBPE)

Radiomics-based predictive risk score: A scoring system for preoperatively predicting risk of lymph node metastasis in patients with resectable non-small cell lung cancer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2019年第4期31卷 641-652页

作者： Lan He Yanqi Huang Lixu Yan Junhui Zheng changhong liang Zaiyi Liu Department of Radiology Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China Department of Pathology Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China

Objective: To develop and validate a radiomics-based predictive risk score(RPRS) for preoperative prediction of lymph node(LN) metastasis in patients with resectable non-small cell lung cancer(NSCLC).Methods: We retrospectively analyzed 717 who underwent surgical resection for primary NSCLC with systematic mediastinal lymphadenectomy from October 2007 to July 2016. By using the method of radiomics analysis, 591 computed tomography(CT)-based radiomics features were extracted, and the radiomics-based classifier was constructed. Then, using multivariable logistic regression analysis, a weighted score RPRS was derived to identify LN metastasis. Apparent prediction performance of RPRS was assessed with its calibration,discrimination, and clinical ***: The radiomics-based classifier was constructed, which consisted of 13 selected radiomics *** models demonstrated that radiomics-based classifier, age group, tumor diameter, tumor location, and CT-based LN status were independent predictors. When we assigned the corresponding score to each variable,patients with RPRSs of 0-3, 4-5, 6, 7-8, and 9 had distinctly very low(0%-20%), low(21%-40%), intermediate(41%-60%), high(61%-80%), and very high(81%-100%) risks of LN involvement, respectively. The developed RPRS showed good discrimination and satisfactory calibration (C-index: 0.785, 95% confidence interval(95% CI):0.780-0.790)Additionally, RPRS outperformed the clinicopathologic-based characteristics model with net reclassification index(NRI) of 0.711(95% CI: 0.555-0.867).Conclusions: The novel clinical scoring system developed as RPRS can serve as an easy-to-use tool to facilitate the preoperatively individualized prediction of LN metastasis in patients with resectable NSCLC. This stratification of patients according to their LN status may provide a basis for individualized treatment.

关键词： Lymph node radiomics risk score CT non-small cell lung cancer

A radiomics prognostic scoring system for predicting progression-free survival in patients with stageⅣnon-small cell lung cancer treated with platinum-based chemotherapy

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2021年第5期33卷 592-605页

作者： Lan He Zhenhui Li Xin Chen Yanqi Huang Lixu Yan changhong liang Zaiyi Liu Department of Radiology Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China Department of Radiology the Third Affiliated Hospital of Kunming Medical UniversityYunnan Cancer HospitalYunnan Cancer CenterKunming 650118China Department of Radiology Guangzhou First People’s HospitalSchool of MedicineSouth China University of TechnologyGuangzhou 510120China The Second School of Clinical Medicine Southern Medical UniversityGuangzhou 510515China Department of Pathology Guangdong Provincial People’s HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China

Objective:To develop and validate a radiomics prognostic scoring system(RPSS)for prediction of progressionfree survival(PFS)in patients with stageⅣnon-small cell lung cancer(NSCLC)treated with platinum-based ***:In this retrospective study,four independent cohorts of stageⅣNSCLC patients treated with platinum-based chemotherapy were included for model construction and validation(Discovery:n=159;Internal validation:n=156;External validation:n=81,Mutation validation:n=64).First,a total of 1,182 three-dimensional radiomics features were extracted from pre-treatment computed tomography(CT)images of each ***,a radiomics signature was constructed using the least absolute shrinkage and selection operator method(LASSO)penalized Cox regression ***,an individualized prognostic scoring system incorporating radiomics signature and clinicopathologic risk factors was proposed for PFS ***:The established radiomics signature consisting of 16 features showed good discrimination for classifying patients with high-risk and low-risk progression to chemotherapy in all cohorts(All P<0.05).On the multivariable analysis,independent factors for PFS were radiomics signature,performance status(PS),and N stage,which were all selected into construction of *** RPSS showed significant prognostic performance for predicting PFS in discovery[C-index:0.772,95%confidence interval(95%CI):0.765-0.779],internal validation(C-index:0.738,95%CI:0.730-0.746),external validation(C-index:0.750,95%CI:0.734-0.765),and mutation validation(Cindex:0.739,95%CI:0.720-0.758).Decision curve analysis revealed that RPSS significantly outperformed the clinicopathologic-based model in terms of clinical usefulness(All P<0.05).Conclusions:This study established a radiomics prognostic scoring system as RPSS that can be conveniently used to achieve individualized prediction of PFS probability for stageⅣNSCLC patients treated with platinumbased chemotherapy,which holds

关键词： Non-small cell lung cancer radiomics prognostic scoring system progression-free survival platinum-based chemotherapy

Radiomics approach for preoperative identification of stages Ⅰ-Ⅱand Ⅲ-Ⅳ of esophageal cancer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2018年第4期30卷 396-405页

作者： Lei WU Cong Wang Xianzheng Tan Zixuan Cheng Ke Zhao Lifen Yan Yanli liang Zaiyi Liu changhong liang School of Medicine South China University of Technology Guangzhou 510006 China Department of Radiology Guangdong General HospitalGuangdong Academy of Medical Sciences Guangzhou 510080 China School of Automation Science and Engineering South China University of Technology Guangzhou 510641 China

Objective： To predict preoperative staging using a radiomics approach based on computed tomography （CT）images of patients with esophageal squamous cell carcinoma （ESCC）.Methods： This retrospective study included 154 patients （primary cohort： n： t 14; validation cohort： n：40） withpathologically confirmed ESCC. All patients underwent a preoperative CT scan from the neck to abdomen. Highthroughput and quantitative radiomics features were extracted from the CT images for each patient. A radiomicssignature was constructed using the least absolute shrinkage and selection operator （Lasso）. Associations betweenradiomics signature, tumor volume and ESCC staging were explored. Diagnostic performance of radiomicsapproach and tumor volume for discriminating between stages Ⅰ-Ⅱand Ⅲ-Ⅳ was evaluated and compared usingthe receiver operating characteristics （ROC） curves and net reclassification improvement （NRI）.Results= A total of 9,790 radiomics features were extracted. Ten features were selected to build a radiomicssignature after feature dimension reduction. The radiomics signature was significantly associated with ESCCstaging （P〈0.001）, and yielded a better performance for discrimination of early and advanced stage ESCC comparedto tumor volume in both the primary [area under the receiver operating characteristic curve （AUC）： 0.795 vs. 0.694,P=0.003; NRI=0.424）] and validation cohorts （AUC： 0.762 vs. 0.624, P=0.035; NRI=0.834）.Conclusions： The quantitative approach has the potential to identify stage Ⅰ-Ⅱand Ⅲ-Ⅳ ESCC beforetreatment.

关键词： Esophageal cancer tumor staging diagnostic imaging tumor volume

Application of quantitative imaging in oncologic management

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2018年第4期30卷 395-395页

作者： changhong liang Department of Radiology Guangdong General HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China

Medical imaging, such as computed tomography （CT）, magnetic resonance imaging （MRI） and positron emissiontomography （PET）, plays a vital role for the decision-making in oncologic management. In clinical practice, imaging-derivedtumor metrics are routinely applied in oncologic management as an imaging biomarker. For example, the ResponseEvaluation Criteria in Solid Tumors （RECIST） are commonly used for tumor treatment response evaluation based on thedynamic changes in tumor size. However, the current cross-sectional images are interpreted qualitatively for lesioncharacterization, treatment response evaluation and prognostic prediction by highly trained radiologists, which hasincreasingly apparent limitations. Therefore, there is a demanding shift toward more quantitative imaging interpretation.

关键词： Application of quantitative imaging in oncologic management

Individualized prediction of perineural invasion in colorectal cancer: development and validation of a radiomics prediction model

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2018年第1期30卷 40-50页

作者： Yanqi Huang Lan He Di Dong Caiyun Yang Cuishan liang Xin Chen Zelan Ma Xiaomei Huang Su Yao changhong liang Jie Tian Zaiyi Liu Department of Radiology Guangdong General Hospital Guangdong Academy of Medical Sciences School of Medicine South China University of Technology Key Laboratory of Molecular Imaging Chinese Academy of Sciences Department of Radiology the Affiliated Guangzhou First People's Hospital Guangzhou Medical University Department of Pathology Guangdong General Hospital Guangdong Academy of Medical Sciences

Objective： To develop and validate a radiomics prediction model for individualized prediction of perineural invasion（PNI） in colorectal cancer（CRC）.Methods： After computed tomography（CT） radiomics features extraction, a radiomics signature was constructed in derivation cohort（346 CRC patients）. A prediction model was developed to integrate the radiomics signature and clinical candidate predictors [age, sex, tumor location, and carcinoembryonic antigen（CEA） level]. Apparent prediction performance was assessed. After internal validation, independent temporal validation（separate from the cohort used to build the model） was then conducted in 217 CRC patients. The final model was converted to an easy-to-use ***： The developed radiomics nomogram that integrated the radiomics signature and CEA level showed good calibration and discrimination performance [Harrell＇s concordance index（c-index）： 0.817; 95% confidence interval（95% CI）： 0.811–0.823]. Application of the nomogram in validation cohort gave a comparable calibration and discrimination（c-index： 0.803; 95% CI： 0.794–0.812）.Conclusions： Integrating the radiomics signature and CEA level into a radiomics prediction model enables easy and effective risk assessment of PNI in CRC. This stratification of patients according to their PNI status may provide a basis for individualized auxiliary treatment.

关键词： Colorectal cancer perineural invasion prediction model radiomics nomogram

在线全文

学校读者我要写书评

暂无评论

几个重要常数的差比数列研究

西安电子科技大学学报 2011年第6期38卷 163-166,192页

作者：梁昌洪史琰西安电子科技大学天线与微波技术重点实验室陕西西安710071

着重研究了几个重要常数所构成的差比数列.除圆周率π和指数e之外,还引入了Euler常数γ和非线性混沌点k∞,它们几乎无一例外地当n充分大时,趋于一定值,这其中的奥秘很值得进一步探索.文中还给出了这几个重要常数的最佳有理分数逼近.

关键词：重要常数差比数列最佳有理分数

Prognostic value of a modified Immunoscore in patients with stage Ⅰ-Ⅲ resectable colon cancer

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Cancer Research 2021年第3期33卷 379-390页

作者： Ke Zhao Xiaomei Wu Zhenhui Li Yingyi Wang Zeyan Xu Yajun Li Lin Wu Su Yao Yanqi Huang changhong liang Zaiyi Liu Department of Radiology Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China School of Medicine South China University of TechnologyGuangzhou 510006China Department of Radiology the Sixth Affiliated Hospital of Sun Yat-sen UniversityGuangzhou 510655China Department of Radiology the Third Affiliated Hospital of Kunming Medical UniversityYunnan Cancer HospitalYunnan Cancer CenterKunming 650118China Department of Radiology Zhuhai People's HospitalZhuhai Hospital Affiliated with Jinan UniversityZhuhai 519000China Department of Pathology the Third Affiliated Hospital of Kunming Medical UniversityYunnan Cancer HospitalYunnan Cancer CenterKunming 650118China Department of Pathology Guangdong Provincial People's HospitalGuangdong Academy of Medical SciencesGuangzhou 510080China the Second School of Clinical Medicine Southern Medical UniversityGuangzhou 510080China

Objective: The Immunoscore method has proved fruitful for predicting prognosis in patients with colon ***, there is still room for improvement in this scoring method to achieve further advances in its clinical translation. This study aimed to develop and validate a modified Immunoscore(IS-mod) system for predicting overall survival(OS) in patients with stage Ⅰ-Ⅲ colon ***: The IS-mod was proposed by counting CD3+ and CD8+ immune cells in regions of the tumor core and its invasive margin by drawing two lines of interest. A discovery cohort(N=212) and validation cohort(N=103)from two centers were used to evaluate the prognostic value of the ***: In the discovery cohort, 5-year survival rates were 88.6% in the high IS-mod group and 60.7% in the low IS-mod group. Multivariate analysis confirmed that the IS-mod was an independent prognostic factor for OS[adjusted hazard ratio(HR)=0.36, 95% confidence interval(95% CI): 0.20-0.63]. With less annotation and computation cost, the IS-mod achieved performance comparable to that of the Immunoscore-like(IS-like) system(C-index, 0.676 vs. 0.661, P=0.231). The 2-category IS-mod using 47.5% as the threshold had a better prognostic value than that using a fixed threshold of 25%(C-index, 0.653 vs. 0.573, P=0.004). Similar results were confirmed in the validation ***: Our method simplifies the annotation and accelerates the calculation of Immunoscore method,thus making it easier for clinical implementation. The IS-mod achieved comparable prognostic performance when compared to the IS-like system in both cohorts. Besides, we further found that even with a small reference set(N≥120), the IS-mod still demonstrated a stable prognostic value. This finding may inspire other institutions to develop a local reference set of an IS-mod system for more accurate risk stratification of colon cancer.

关键词： Immunoscore colon cancer whole-slide image overall survival digital pathology