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Nonparametric Estimation of Interval-censored Failure Time Data in the Presence of Informative Censoring

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Acta Mathematicae Applicatae Sinica 2017年第1期33卷 107-114页

作者： Chun-jie WANG jian-guo sun De-hui WANG Ning-zhong SHI The College of Basic Science Changchun University of Technology Changchun 130012 China Mathematics School and Institute of Jilin University Changchun 130012 China Department of Statistics University of Missouri 146 Middlebush Hall MO 65211. USA Key Laboratory of Applied Statistics of MOE School of Mathematics and Statistics Northeast Normal University Changchun 130024 China

Nonparametric estimation of a survival function is one of the most commonly asked questions in the analysis of failure time data and for this, a number of procedures have been developed under various types of censoring structures （Kalbfleisch and Prentice, 2002）. In particular, several algorithms are available for interval-censored failure time data with independent censoring mechanism （sun, 2006; Turnbull, 1976）. In this paper, we consider the interval-censored data where the censoring mechanism may be related to the failure time of interest, for which there does not seem to exist a nonparametric estimation procedure. It is well-known that with informative censoring, the estimation is possible only under some assumptions. To attack the problem, we take a copula model approach to model the relationship between the failure time of interest and censoring variables and present a simple nonparametric estimation procedure. The method allows one to conduct a sensitivity analysis among others.

关键词： copula models interval censored data dependent censoring nonparametric estimation

In situ study of calcite-Ⅲ dimorphism using dynamic diamond anvil cell

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Chinese Physics B 2022年第9期31卷 421-427页

作者： Xia Zhao Sheng-Hua Mei Zhi Zheng Yue Gao jiang-Zhi Chen Yue-Gao Liu jian-guo sun Yan Li jian-Hui sun CAS Key Laboratory for Experimental Study under Deep-sea Extreme Conditions Institute of Deep-sea Science and EngineeringChinese Academy of Sciences(CAS)Sanya 572000China University of Chinese Academy of Sciences Beijing 100049China Department of Mechanical Engineering National University of Singapore(NUS)Singapore 117575Singapore

The phase transitions among the high-pressure polymorphic forms of CaCO_(3)(cc-Ⅰ,cc-Ⅱ,cc-Ⅲ,and cc-Ⅲb)are investigated by dynamic diamond anvil cell(dDAC)and in situ Raman *** are carried out at room temperature and high pressures up to 12.8 GPa with the pressurizing rate varying from 0.006 GPa/s to 0.056 GPa/*** situ observation shows that with the increase of pressure,calcite transforms from cc-Ⅰto cc-Ⅱat~1.5 GPa and from cc-Ⅱto cc-Ⅲat~2.5 GPa,and transitions are independent of the pressurizing ***,as the pressure continues to increase,the cc-Ⅲb begins to appear and coexists with cc-Ⅲwithin a pressure range that is inversely proportional to the pressurizing *** the pressurizing rates of 0.006,0.012,0.021,and 0.056 GPa/s,the coexistence pressure ranges of cc-Ⅲand cc-Ⅲb are 2.8 GPa-9.8 GPa,3.1 GPa-6.9 GPa,2.7 GPa-6.0 GPa,and 2.8 GPa-4.5 GPa,*** dependence of the coexistence on the pressurizing rate may result from the influence of pressurizing rate on the activation process of transition by reducing the energy *** higher the pressurizing rate,the lower the energy barrier is,and the easier it is to pull the system out of the coexistence *** results of this in situ study provide new insights into the understanding of the phase transition of calcite.

关键词： calcite-Ⅲ dimorphism dynamic diamond anvil cell in situ Raman spectroscopy pressurizing rate

Pharmacokinetics of recombinant human basic fibroblast growth factor in rabbits and mice serum and rabbits aqueous humor

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Acta Pharmacologica Sinica 2004年第8期 17-21页

作者： Qi ZHANG, Guang-ji WANG, jian-guo sun Center of Drug Metabolism and Pharmacokinetics, China Pharmaceutical University, Nanjing 210009, China

AIM: To study the pharmacokinetics of recombinant human basic fibroblast growth factor (rhbFGF) in rabbits and mice after iv and postocular administration, and the changes of rhbFGF in rabbits aqueous humor after postocular administration. METHODS: After iv or postocular administration three doses of rhbFGF in rabbits and mice, rhbFGF concentration in serum and rabbit aqueous humor was determined by enzyme-linked immunosorbent assay. RESULTS: Serum concentration-time data of rabbits after iv administration of rhbFGF 1, 2, and 4 μg/kg were fitted to bi-exponential equations with half-lives of 0.9, 0.9, and 0.6 min for T1/2α and 7, 8, and 4.7 min for T1/2β. Plasma concentration-time data of mice after iv administration of rhbFGF 2.5, 5 and 10 μg/kg were fitted to bi exponential equations with half-lives of 0.4, 0.6, and 0.9 min for T1/2α　and 6, 5, and 7 min for T1/2β.The AUCs were linearly correlated to doses in both cases (rrabbit=0.997, rmouse=0.999). The serum concentrations of rhbFGF were very l

关键词： fibroblast growth factor 2 pharmacokinetics enzyme-linked immunosorbent assay aqueous humor rabbits mice

Cyclosporine A-loaded drug delivery systems inhibit scar formation after glaucoma surgery in rabbits

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Chinese Medical Journal 2019年第11期132卷 1381-1384页

作者： Zhao-Xing Dai Xiao-Le Song Xiao-Bo Yu jian-guo sun Xing-Huai sun Department of Ophthalmology and Visual Science Eye and ENT Hospital Shanghai Medical College Fudan University Shanghai 200031 China Department of Ear-Nose-Throat Eye and ENT Hospital Shanghai Medical College Fudan University Shanghai 200031 China Research Center Eye and ENT Hospital Shanghai Medical College Fudan University Shanghai 200031 China Key Laboratory of Myopia NHFPC and Shanghai Key Laboratory of Visual Impairment and Restoration Fudan University Shanghai 200031 China State Key Laboratory of Medical Neurobiology Institutes of Brain Science and Collaborative Innovation Center for Brain Science Fudan University Shanghai 200032 China

To the Editor:Glaucoma is the primary cause of irreversible blindness. Surgery is the main treatment option if intraocular pressure (IOP) cannot be controlled with medications. Local fibroblast proliferation and collagen deposition cause stenosis of drainage channels and scar formation in the filtration area, which are the main causes of unsuccessful antiglaucoma surgery. Application of mitomycin C during surgery is one of the most widely performed clinical interventions aimed at modifying the wound healing process. However, recent reports suggest that there is scope to further improve the outcomes of mitomycin C application in surgery.

关键词： glaucoma intraocular pressur mitomycin C

Brain endothelial cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING)signaling pathway in aging and neurodegeneration

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Neural Regeneration Research 2025年第7期20卷 2005-2007页

作者： Bryan sun Lulin Li jian Luo Palo Alto Veterans Institute for Research VA Palo Alto Health Care SystemPalo AltoCAUSA Polytrauma System of Care VA Palo Alto Health Care SystemPalo AltoCAUSA

The cyclic GMP-AMP synthase(cGAS)-stimulator of interferon genes(STING)signaling pathway has emerged as a key mediator of *** current studies primarily attribute its effects to neurons and glial cells,emerging research suggests that cGAS-STING signaling may play a critical role in cerebral vasculature,particularly in brain endothelial ***,studying the role 7of inflammation caused by the cGAS-STING pathway in brain endothelial cells could provide a more comprehensive understanding of neuroinflammatory disease and new avenues for therapeutic ***,we review the multifaceted role of global cGAS-STING signaling in various neurological and neuroinflammatory diseases and the potential contribution of cGAS-STING in brain endothelial cells.

关键词： stimulator interferon inflammation

A Computational Study of the Gas-Solid Suspension Flow through a Supersonic Nozzle

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Open Journal of Fluid Dynamics 2012年第4期2卷 242-247页

作者： jian guo sun Heuy Dong Kim Jin Ouk Park Ying Zi Jin College of Mechanical Engineering & Automation Zhejiang Sci-Tech University Hangzhou China School of Mechanical Engineering Andong National University Andong Korea

The present study focuses on numerical simulation of the gas-solid suspension flow in a supersonic nozzle. The Euler- Lagrange approach using a Discrete Phase Model (DPM) has been used to solve the compressible Navier-Stokes equa- tions. A fully implicit finite volume scheme has been employed to discretize the governing equations. Based upon the present CFD results, the particle loading effect on gas-solid suspension flow was investigated. The results show that the presence of particles has a big influence on the gas phase behavior. The structure of shock train, the separation point, and the vortex of the backflow are all related to particle loading. As the particle loading increases the flow characteris- tics behave differently such as 1) the strength of shock train decreases, 2) the separation point moves toward the nozzle exit, 3) the number and strength of vortex increase, 4) the strength of first shock also increases while the other pseudo shocks decreases. The change of gas flow behavior in turn affects the particle distribution. The particles are concen- trated at the shear layers separated from the upper wall surface.

关键词： Gas-Solid Suspension Flow Supersonic Nozzle Flow Choking Internal Flow Shock Wave

Inexact proximal gradient algorithm with random reshuffling for nonsmooth optimization

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Science China(Information Sciences) 2025年第1期68卷 219-237页

作者： Xia jianG Yanyan FANG Xianlin ZENG jian sun Jie CHEN National Key Lab of Autonomous Intelligent Unmanned Systems School of AutomationBeijing Institute of Technology Beijing Institute of Technology Chongqing Innovation Center School of Electronic and Information Engineering Tongji University

Proximal gradient algorithms are popularly implemented to achieve convex optimization with nonsmooth regularization. Obtaining the exact solution of the proximal operator for nonsmooth regularization is challenging because errors exist in the computation of the gradient; consequently, the design and application of inexact proximal gradient algorithms have attracted considerable attention from researchers. This paper proposes computationally efficient basic and inexact proximal gradient descent algorithms with random reshuffling. The proposed stochastic algorithms take randomly reshuffled data to perform successive gradient descents and implement only one proximal operator after all data pass through. We prove the convergence results of the proposed proximal gradient algorithms under the sampling-without-replacement reshuffling *** computational errors exist in gradients and proximal operations, the proposed inexact proximal gradient algorithms can converge to an optimal solution neighborhood. Finally, we apply the proposed algorithms to compressed sensing and compare their efficiency with some popular algorithms.

关键词： proximal operator random reshuffling inexact computation compressed sensing nonsmooth optimization

A Mn-porphyrinic metal–organic framework immobilizing glucose oxidase for combined photodynamic/chemodynamic/starvation therapy

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Tungsten 2025年第1期7卷 183-194页

作者： Xin-Ran sun Hao-Ming Yuan guo-Da Zhang Chao Wang Shu-Juan sun Peng-Fei Shi Shandong Provincial Key Laboratory of Detection Technology for Tumor Markers School of Chemistry and Chemical Engineering Linyi University

The combination of photodynamic therapy（PDT） and chemodynamic therapy（CDT） in tumor treatment has attracted considerable ***,tumor hypoxia and glutathione（GSH） overproduction in the tumor tissue restricted the progress of their ***,a Mn-porphyrinic metal-organic framework（Mn-TCPP） was constructed by the one-pot method and further used for immobilizing glucose oxidase（GOx） to obtain GOx@*** would rapidly exhaust endogenous glucose into hydrogen peroxide（H2O2） and gluconic acid,thus shutting off the energy supply of tumor cells for starvation ***-TCPP catalyzed H2O2to produce oxygen,regulating the hypoxic tumor microenvironment and in turn improving1O2generation under laser ***,Mn-TCPP can reduce reactive oxygen species consumption owing to the redox reaction between Mn3+and GSH,thus greatly enhancing ***,benefiting from GOx-mediated starvation therapy,Mn2+produced by Mn3+reduction can react with sufficient intracellular H2O2to generate ·OH with high cytotoxicity through a Fenton-like *** treatment by GOx@Mn-TCPP under laser irradiation in vitro,the cell viability of 4T1 and A549 tumor cells reached to 20%,reflecting GOx@Mn-TCPP could give full play to the advantages of PDT/CDT/starvation *** results in vivo demonstrated that GOx@Mn-TCPP mediated synergistic cascade therapy could significantly inhibit tumor growth and improve the therapeutic effect.

关键词： Chemodynamic therapy Immobilizing enzyme Metal–organic frameworks Photodynamic therapy Starvation therapy

Buried interface bridging for inverted cesium-formamidinium triiodide perovskite solar cells with long operational stability

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Science China Chemistry 2025年第1期68卷 163-173页

作者： Chenhui Zhang Chunjun Liang Fulin sun Ting Zhu Xinghai Huang Yuzhu guo Xinyu guo Kunyang Ge Dan Li Fangtian You Zhiqun He Key Laboratory of Luminescence and Optical Information Ministry of Education Institute of Optoelectronic TechnologyBeijing Jiaotong University Department of Physics School of Physical Science and Engineering Beijing Jiaotong University

In the field of perovskite solar cells(PSCs), the research on defects in the buried interface has been relatively limited due to its non-exposure; however, this interface significantly impacts the performance enhancement of inverted PSCs. This study employs phenylethylammonium chloride(PEACl) molecules as a buffer layer to modify the buried interface of p-i-n structured PSCs,aiming to enhance the uniformity of self-assembled monolayers(SAMs) and facilitate the uniform nucleation and growth of perovskite films on the substrate. Furthermore, the introduction of the PEACl buffer layer effectively passivates defects at the bottom of the perovskite layer and notably enhances the crystal quality of the perovskite film by mitigating residual stress,thereby reducing nonradiative recombination loss. Following these optimizations, the MA-free PSCs treated with PEACl achieve a power conversion efficiency(PCE) of 24.11%, with significant improvements in storage, thermal stability, and operational stability. Particularly noteworthy is the device's performance in an unencapsulated state, whereas after 1,500 hours of continuous light operation stability testing, it retains 97% of its original efficiency. This study not only enriches the systematic understanding of the characteristics of the buried interface in PSCs but also contributes significantly to advancing the commercial production of perovskite photovoltaic technology.

关键词： defect-induced recombination buried interfaces inverted perovskite solar cells crystallization lattice mismatch