Circuit Model for the Effect of Nonradiative Recombination in a High-Speed Distributed-Feedback Laser

Bowen Nie,Zhijuan Chi,Qing-an Ding,Xiang Li,Changqing Liu,Xiaojuan Wang,Lijun Zhang,Juan Song,Chaofan Li 한국광학회 2020 Current Optics and Photonics Vol.4 No.5

Based on single-mode rate equations, we present an improved equivalent-circuit model for distributedfeedback (DFB) lasers that accounts for the effects of parasitic parameters and nonradiative recombination. This equivalent-circuit model is composed of a parasitic circuit, an electrical circuit, an optical circuit, and a phase circuit, modeling the circuit equations transformed from the rate equations. The validity of the proposed circuit model is verified by comparing simulation results to measured results in the literature. The results show that the slope efficiency and threshold current of the model are 0.22 W/A and 13 mA respectively. It is also shown that increasing bias current results in the increase of the relaxation-oscillation frequency. Moreover, we show that the larger the bias current, the lower the frequency chirp, increasing the possibility of extending the transmission distance of an optical-fiber communication system. The results indicate that the proposed circuit model can accurately predict a DFB laser’s static and dynamic characteristics.

Bufalin Induces Mitochondrial Pathway-Mediated Apoptosis in Lung Adenocarcinoma Cells

Ding, Da-Wei,Zhang, Yong-Hong,Huang, Xin-En,An, Qing,Zhang, Xun Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.23

Background: To evaluate the effects of bufalin in A549 human lung adenocarcinoma epithelial cells in vitro and assess the underlying mechanisms. Materials and Methods: Human A549 non-small cell lung cancer (NSCLC) cells were treated with various concentrations of bufalin. Cell proliferation was measured by CCK-8 assay, apoptotic cell percentage was calculated by flow cytometry and morphological change was observed by inverted phase contrast microscopy/transmission electron microscopy. In addition, the membrane potential of mitochondria was detected by JC-1 fluorescence microscopy assay, and the related protein expression of cytochrome C and caspase-3 was analyzed by Western blotting. Results: Bufalin could inhibit the proliferation of A549 cells via induction of apoptosis, with the evidence of characteristic morphological changes in the nucleus and mitochondria. Furthermore, bufalin decreased the mitochondrial membrane potential with up-regulation of cytochrome C in the cytosol, and activation of caspase-3. Conclusions: Bufalin inhibits the proliferation of A549 cells and triggers mitochondria-dependent apoptosis, pointing to therapeutic application for NSCLC.

Preparation and Biocompatibility Study of Contrast-Enhanced Hernia Mesh Material

Ding Xuzhong,Zhu Jiachen,Liu Anning,Guo Qiyang,Cao Qing,Xu Yu,Hua Ye,Yang Yumin,Li Peng 한국조직공학과 재생의학회 2022 조직공학과 재생의학 Vol.19 No.4

BACKGROUND: Meshes play a crucial role in hernia repair. However, the displacement of mesh inevitably leads to various associated complications. This process is difficult to be traced by conventional imaging means. The purpose of this study is to create a contrast-enhanced material with high-density property that can be detected by computed tomography (CT). METHODS: The contrast-enhanced monofilament was manufactured from barium sulfate nanoparticles and medical polypropylene (PP/Ba). To characterize the composite, stress tensile tests and scanning electron microscopy (SEM) was performed. Toxicity and biocompatibility of PP/Ba materials was verified by in vitro cellular assays. Meanwhile, the inflammatory response was tested by protein adsorption assay. In addition, an animal model was established to demonstrate the long-term radiographic effect of the composite material in vivo. Subsequent pathological tests confirmed its in vivo compatibility. RESULTS: The SEM revealed that the main component of the monofilament is carbon. In vitro cell experiments demonstrated that novel material does not affect cell activity and proliferation. Protein adsorption assays indicated that the contrast-enhanced material does not cause additional inflammatory responses. In addition, in vivo experiments illustrated that PP/Ba mesh can be detected by CT and has good in vivo compatibility. CONCLUSION: These results highlight the excellent biocompatibility of the contrast-enhanced material, which is suitable for human abdominal wall tissue engineering.

Finite Frequency Fault Detection for T-S Fuzzy Singular Multiple Timedelay Systems

Ding Zhai,Li-Wei An,Jing-Hao Li,Qing-Ling Zhang 제어·로봇·시스템학회 2016 International Journal of Control, Automation, and Vol.14 No.4

This paper focuses on the problem of fault detection (FD) for a class of nonlinear systems describedby the T-S fuzzy singular model with multiple time delays and actuator faults. Two finite-frequency performanceindices are introduced to measure fault sensitivity and disturbance robustness. To reduce the conservatism of theexisting results, a finite frequency domain approach to fuzzy singular multiple time-delay systems is proposed. Then based on the approach, filter design conditions for the solvability of this problem are presented in terms oflinear matrix inequalities (LMIs). Finally, simulation studies are provided to demonstrate the application of theproposed method.

Experimental investigation of long-term characteristics of greenschist

Zhang, Qing-Zhao,Shen, Ming-Rong,Ding, Wen-Qi,Jang, Hyun-Sic,Jang, Bo-An Techno-Press 2016 Geomechanics & engineering Vol.11 No.4

The greenschist in the Jinping II Hydropower Station in southwest China exhibits continuous creep behaviour because of the geological conditions in the region. This phenomenon illustrates the time-dependent deformation and progressive damage that occurs after excavation. In this study, the responses of greenschist to stress over time were determined in a series of laboratory tests on samples collected from the access tunnel walls at the construction site. The results showed that the greenschist presented time-dependent behaviour under long-term loading. The samples generally experienced two stages: transient creep and steady creep, but no accelerating creep. The periods of transient creep and steady creep increased with increasing stress levels. The long-term strength of the greenschist was identified based on the variation of creep strain and creep rate. The ratio of long-term strength to conventional strength was around 80% and did not vary much with confining pressures. A quantitative method for predicting the failure period of greenschist, based on analysis of the stress-strain curve, is presented and implemented. At a confining pressure of 40 MPa, greenschist was predicted to fail in 5000 days under a stress of 290 MPa and to fail in 85 days under the stress of 320 MPa, indicating that the long-term strength identified by the creep rate and creep strain is a reliable estimate.

Influence of Ribosomal Protein L39-L in the Drug Resistance Mechanisms of Lacrimal Gland Adenoid Cystic Carcinoma Cells

Ye, Qing,Ding, Shao-Feng,Wang, Zhi-An,Feng, Jie,Tan, Wen-Bin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.12

Background: Cancer constitutes a key pressure on public health regardless of the economy state in different countries. As a kind of highly malignant epithelial tumor, lacrimal gland adenoid cystic carcinoma can occur in any part of the body, such as salivary gland, submandibular gland, trachea, lung, breast, skin and lacrimal gland. Chemotherapy is one of the key treatment techniques, but drug resistance, especially MDR, seriously blunts its effects. As an element of the 60S large ribosomal subunit, the ribosomal protein L39-L gene appears to be documented specifically in the human testis and many human cancer samples of different origins. Materials and Methods: Total RNA of cultured drug-resistant and susceptible lacrimal gland adenoid cystic carcinoma cells was seperated, and real time quantitative RT-PCR were used to reveal transcription differences between amycin resistant and susceptible strains of lacrimal gland adenoid cystic carcinoma cells. Viability assays were used to present the amycin resistance difference in a RPL39-L transfected lacrimal gland adenoid cystic carcinoma cell line as compared to control vector and null-transfected lacrimal gland adenoid cystic carcinoma cell lines. Results: The ribosomal protein L39-L transcription level was 6.5-fold higher in the drug-resistant human lacrimal gland adenoid cystic carcinoma cell line than in the susceptible cell line by quantitative RT-PCR analysis. The ribosomal protein L39-L transfected cells revealed enhanced drug resistance compared to plasmid vector-transfected or null-transfected cells as determined by methyl tritiated thymidine (3H-TdR) incorporation. Conclusions: The ribosomal protein L39-L gene could possibly have influence on the drug resistance mechanism of lacrimal gland adenoid cystic carcinoma cells.

Event-triggered Control for Heterogeneous Discrete-time Multi-agent Systems Subject to Uncertainties and Noises

Jie Zhang,Da-Wei Ding,Qing Li,Cuijuan An 제어·로봇·시스템학회 2020 International Journal of Control, Automation, and Vol.18 No.3

This paper investigates the event-triggered control problem of heterogeneous discrete-time multi-agent systems (MASs) subject to uncertainties and noises. Based upon the output regulation theory, a new distributed event-triggered control scheme is proposed to reduce communication burden and attenuate effects of stochastic noises. Two types of event-triggered control laws based on dynamic state feedback and dynamic output feedback are designed, respectively. Moreover, to compensate parameter uncertainties, a p-copy internal model is synthesized into the designed controllers. It is shown that all tracking errors are exponentially ultimately bounded in the mean square sense regardless of uncertainties and noises. Several examples are finally given to demonstrate the validity of main results.

A Retrospective Study of the Effect of Spinopelvic Parameters on Fatty Infiltration in Paraspinal Muscles in Patients With Lumbar Spondylolisthesis

Jia-Chen Yang,Jia-Yu Chen,Yin Ding,Yong-Jie Yin,Zhi-Ping Huang,Xiu-Hua Wu,Zu-Cheng Huang,Yi-Kai Li,Qing-An Zhu 대한척추신경외과학회 2024 Neurospine Vol.21 No.1

Objective: The effect on fat infiltration (FI) of paraspinal muscles in degenerative lumbar spinal diseases has been demonstrated except for spinopelvic parameters. The present study is to identify the effect of spinopelvic parameters on FI of paraspinal muscle (PSM) and psoas major muscle (PMM) in patients with degenerative lumbar spondylolisthesis. Methods: A single-center, retrospective cross-sectional study of 160 patients with degenerative lumbar spondylolisthesis (DLS) and lumbar stenosis (LSS) who had lateral full-spine x-ray and lumbar spine magnetic resonance imaging was conducted. PSM and PMM FIs were defined as the ratio of fat to its muscle cross-sectional area. The FIs were compared among patients with different pelvic tilt (PT) and pelvic incidence (PI), respectively. Results: The PSM FI correlated significantly with pelvic parameters in DLS patients, but not in LSS patients. The PSM FI in pelvic retroversion (PT > 25°) was 0.54 ± 0.13, which was significantly higher in DLS patients than in normal pelvis (0.41 ± 0.14) and pelvic anteversion (PT < 5°) (0.34 ± 0.12). The PSM FI of DLS patients with large PI ( > 60°) was 0.50 ± 0.13, which was higher than those with small ( < 45°) and normal PI (0.37 ± 0.11 and 0.36 ± 0.13). However, the PSM FI of LSS patients didn’t change significantly with PT or PI. Moreover, the PMM FI was about 0.10–0.15, which was significantly lower than the PSM FI, and changed with PT and PI in a similar way of PSM FI with much less in magnitude. Conclusion: FI of the PSMs increased with greater pelvic retroversion or larger pelvic incidence in DLS patients, but not in LSS patients.

Diagnosis and Cure Experience of Hepatolithiasis-Associated Intrahepatic Cholangiocarcinoma in 66 Patients

Li, Hong-Yang,Zhou, Shi-Ji,Li, Min,Xiong, Ding,Singh, Akanand,Guo, Qing-Xi,Liu, Chang-An,Gong, Jian-Ping Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.2

Background: The management of hepatolithiasis combined with intrahepatic cholangicarcinoma (IHHCC) remains a challenge due to poor prognosis. The aim of this study was to summarize our diagnosis and cure experience of IHHCC over the recent 10 years. Methods: From January 1996 to January 2006, 66 patients with IHHCC were reviewed retrospectively. Results: Of the 66 patients, 52 underwent surgical resection (radical resection in 38 and palliative in 14) and 8 patients abdominal exploration, while the other 6 cases received endoscopic retrograde biliary internal drainage and stent implantation. In this series, correct diagnosis of advanced stage was made during operation in 8 cases (8/60, 13.3%) and all of them (underwent unnecessary abdominal exploration, among them the positive rate of CA19-9 was 100%, and the positive rate of CEA was 87.6% (7/8), incidence rate of ascites was 100% and short-term significant weight loss was 100%, with median overall survival of only 4 months. Conclusion: Radical resection is mandatory for IHHCC patient to achieve long-term survival, the CT and MR imaging features of IHHCC being concentric enhancement. Patients with IHHCC have significant higher CA199 and significant higher CEA and short-term significant weight loss and ascites should be considered with advanced stage of IHHCC and unnecessary non-therapeutic laparotomies should be avoided.