A High-Frequency Medium-Voltage DC-DC Converter for Future Electric Energy Delivery and Management Systems

Haifeng Fan,Hui Li 전력전자학회 2011 ICPE(ISPE)논문집 Vol.2011 No.5

This paper proposes a high-frequency dc-dc converter for the medium-voltage application of future electric energy delivery and management systems. The proposed dc-dc converter uses low-voltage MOSFETs, featuring low conduction loss and good switching performance with high-frequency operation, to handle medium-voltage input by utilizing input-series-output-parallel (ISOP) modular structure. In addition, phase-shift zero-voltage-switching technique is employed for the constituent module to achieve low switching loss under high-frequency operation. As a result, high efficiency and high power density can be expected. Moreover, the expanded power capability can be obtained by directly connecting multiple ISOP converters in input-parallel-out-parallel without any additional control circuit. Large-signal average model is developed to elaborate the proposed distributed control scheme, which can provide plug-and-play capability and high-level fault-tolerance. Finally, the simulation is conducted and presented to evaluate both static and dynamic performances of the proposed dc-dc converter.

Algorithm for Detection of Fire Smoke in a Video Based on Wavelet Energy Slope Fitting

Yi Zhang,Haifeng Wang,Xin Fan 한국정보처리학회 2020 Journal of information processing systems Vol.16 No.3

The existing methods for detection of fire smoke in a video easily lead to misjudgment of cloud, fog and movingdistractors, such as a moving person, a moving vehicle and other non-smoke moving objects. Therefore, analgorithm for detection of fire smoke in a video based on wavelet energy slope fitting is proposed in this paper. The change in wavelet energy of the moving target foreground is used as the basis, and a time window of 40continuous frames is set to fit the wavelet energy slope of the suspected area in every 20 frames, thusestablishing a wavelet-energy-based smoke judgment criterion. The experimental data show that the algorithmdescribed in this paper not only can detect smoke more quickly and more accurately, but also can effectivelyavoid the distraction of cloud, fog and moving object and prevent false alarm.

Triptolide downregulates Rac1 and the JAK/STAT3 pathway and inhibits colitis-related colon cancer progression

Zhipeng Wang,Haifeng Jin,Ruodan Xu,Qibing Mei,Daiming Fan 생화학분자생물학회 2009 Experimental and molecular medicine Vol.41 No.10

Triptolide, a diterpenoid triepoxide from the traditional Chinese medicinal herb Tripterygium wilfordii Hook. f., is a potential treatment for autoimmune diseases as well a possible anti-tumor agent. It inhibits proliferation of coloretal cancer cells in vitro and in vivo. In this study, its ability to block progress of colitis to colon cancer, and its molecular mechanism of action are investigated. A mouse model for colitis-induced colorectal cancer was used to test the effect of triptolide on cancer progression. Treatment of mice with triptolide decreased the incidence of colon cancer formation, and increased survival rate. Moreover, triptolide decreased the incidence of tumors in nude mice inoculated with cultured colon cancer cells dose-dependently. In vitro, triptolide inhibited the proliferation, migration and colony formation of colon cancer cells. Secretion of IL6 and levels of JAK1, IL6R and phosphorylated STAT3 were all reduced by triptolide treatment. Triptolide prohibited Rac1 activity and blocked cyclin D1 and CDK4 expression, leading to G1 arrest. Triptolide interrupted the IL6R-JAK/STAT pathway that is crucial for cell proliferation, survival, and inflammation. This suggests that triptolide might be a candidate for prevention of colitis induced colon cancer because it reduces inflammation and prevents tumor formation and development. Triptolide, a diterpenoid triepoxide from the traditional Chinese medicinal herb Tripterygium wilfordii Hook. f., is a potential treatment for autoimmune diseases as well a possible anti-tumor agent. It inhibits proliferation of coloretal cancer cells in vitro and in vivo. In this study, its ability to block progress of colitis to colon cancer, and its molecular mechanism of action are investigated. A mouse model for colitis-induced colorectal cancer was used to test the effect of triptolide on cancer progression. Treatment of mice with triptolide decreased the incidence of colon cancer formation, and increased survival rate. Moreover, triptolide decreased the incidence of tumors in nude mice inoculated with cultured colon cancer cells dose-dependently. In vitro, triptolide inhibited the proliferation, migration and colony formation of colon cancer cells. Secretion of IL6 and levels of JAK1, IL6R and phosphorylated STAT3 were all reduced by triptolide treatment. Triptolide prohibited Rac1 activity and blocked cyclin D1 and CDK4 expression, leading to G1 arrest. Triptolide interrupted the IL6R-JAK/STAT pathway that is crucial for cell proliferation, survival, and inflammation. This suggests that triptolide might be a candidate for prevention of colitis induced colon cancer because it reduces inflammation and prevents tumor formation and development.

Fatigue behavior of hybrid GFRP-concrete bridge decks under sagging moment

Haohui Xin,Yuqing Liu,Jun He,Haifeng Fan,Youyou Zhang 국제구조공학회 2015 Steel and Composite Structures, An International J Vol.18 No.4

This paper presents a new cost-effective hybrid GFRP-Concrete deck system that the GFRP panel serves as both tensile reinforcement and stay-in-place form. In order to understand the fatigue behavior of such hybrid deck, fatigue test on a full-scale specimen under sagging moment was conducted, and a series of static tests were also carried out after certain repeated loading cycles. The fatigue test results indicated that such hybrid deck has a good fatigue performance even after 3.1 million repeated loading cycles. A three-dimensional finite element model of the hybrid deck was established based on experimental work. The results from finite element analyses are in good agreement with those from the tests. In addition, flexural fatigue analysis considering the reduction in flexural stiffness and modulus under cyclic loading was carried out. The predicted flexural strength agreed well with the analytical strength from finite element simulation, and the calculated fatigue failure cycle was consistent with the result based on related S-N curve and finite element analyses. However, the flexural fatigue analytical results tended to be conservative compared to the tested results in safety side. The presented overall investigation may provide reference for the design and construction of such hybrid deck system.

Metal-organic framework-based photodynamic combined immunotherapy against the distant development of triple-negative breast cancer

Xiaoyan Liang,Min Mu,Bo Chen,Rangrang Fan,Haifeng Chen,Bingwen Zou,Bo Han,Gang Guo 한국생체재료학회 2023 생체재료학회지 Vol.27 No.00

Background Triple-negative breast cancer (TNBC) is an aggressive, metastatic and apparently drug-resistant subtype of breast cancer with a higher immune response compared to other types of breast cancer. Photodynamic therapy (PDT) has been gaining popularity for its non-invasive nature, minimal side effects, and spatiotemporally controlled benifits. The use of metal-organic frameworks (MOFs) loaded with programmed death-ligand 1 inhibitors (iPD-L1) offers the possibility of combining PDT with immunotherapy. Method Here, we construct PCN-224, a MOFs with good biocompatibility and biodegradability for the delivery of the PD-L1 small molecule inhibitor BMS-202 to achieve a synergistic anti-tumor strategy of PDT and immunotherapy. Hyaluronic acid (HA) modified PEG (HA-PEG) was synthesized for the outer layer modification of the nanocomplex, which prolongs its systemic circulation time. Results In vitro cellular experiments show that the nanocomplexes irradiated by 660 nm laser has a strong ability to produce singlet oxygen, which effectively induce PDT. PDT with strong immunogenicity leads to tumor necrosis and apoptosis, and induces immunogenic cell death, which causes tumor cells to release danger associated molecular patterns. In combination with iPD-L1, the combination therapy stimulates dendritic cell maturation, promotes T-cell activation and intratumoral infiltration, and reshapes the tumor immune microenvironment to achieve tumor growth inhibition and anti-distant tumor progression. Conclusions MOFs-based nano-systems as a platform for combination therapy offer a potentially effective strategy for the treatment of TNBC with high metastatic rates.

Eco-friendly Polypyrrole-coated Cocozelle Composites for Supercapacitor Application

Hui Ji,Chuanjie Zhang,Weida Rao,Bin Guo,Lingling Fan,Zikui Bai,Haifeng Bao,Jie Xu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.6

Cocozelle is essentially consisted of hemicellulose and lignin with a hierarchically porous structure. Herein,cocozelle slices after freeze-drying were employed as green substrates to support the growth of polypyrrole (PPy) via a facileoxidative polymerization approach. The cocozelle surface was densely covered with sheet-like PPy due to the hydrogenbonding between PPy and cocozelle. The PPy/cocozelle composites could be facilely utilized as supercapacitor electrodes,which showed a high specific capacitance of 1108 F g-1 with an energy density of 70.5 Wh kg-1 and a power density of398 W kg-1 at a charge/discharge current density of 0.8 mA cm-2 as well as desirable cycling life with a capacitance retentionrate of 76.9 % after 1000 cycles. Moreover, 95.3 % of the initial specific capacitance obtained at 0.2 mA cm-2 could bereached as the current density increased to 1.6 mA cm-2. These results demonstrate that cocozelle could be used as a superioralternative biomass-derived substrate for the developments of eco-friendly and renewable energy storage devices.