Influence of errors and floating on static load-sharing characteristics of twin rotors concentric face-gear power-split transmission system

Hao Dong,Hao-Qin Zhang,Gang Liang,Bing-Xing Ren,Xiao-Long Zhao 대한기계학회 2023 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.37 No.4

Twin rotors concentric face-gear power-split transmission system (TRCFGPSTS) is a new and more advanced main reducer configuration of the high-speed helicopter. Its loadsharing performance between different branches has a great impact on the service life performance. Its load distribution is complex, and the research on the influence law of error on loadsharing performance is not clear. Therefore, to study the influence of system error and pinions floating on the mechanical properties of the system, the static load-sharing mathematical model of the system was established. The load-sharing model comprehensively considers the factors of manufacturing error (ME) and installation error (IE), meshing stiffness, torsional stiffness, support stiffness and member floating. The coordination conditions of torsional angle elastic deformation of the system with central displacement offset and the mechanical balance conditions under the action of elastic support and floating support are derived, which reflects the change law of load distribution from the perspective of the system as a whole. The load-sharing model is solved by the least square method. The load-sharing coefficient (LSC) of the system is obtained. The influence of ME, IE and floating pinions on load-sharing performance is analyzed. The results show that the LSC shows irregular periodic fluctuation under the combined action of error, and the LSC is 1.212. Under the single influence of ME, the LSC also shows irregular periodic fluctuation, and the LSC is 1.610. Under the single influence of IE, the LSC presents a constant influence law, and the LSC is 1.326. The error of each gear in the III-stage has the most obvious influence on the load-sharing characteristics. The LSC of I-stage and II-stage floating pinion under the single influence are 1.113 and 1.120, respectively. The floating gear can significantly improve the load-sharing performance, and meet the load-sharing at the ±5 % service requirement.

Analysis of the LED Lamp Arrangement for Uniformity of Illumination in Indoor VLC System

Hao Hong-gang,Zhang Dan-dan,Tang Shuai 한국광학회 2014 Current Optics and Photonics Vol.18 No.6

LED lamp arrangement is a critical issue in indoor visible light communication (VLC) system. In this paper, we analyze the illumination distribution under the arrangement of 2×3 and propose a method to find the optimal lamp arrangement. The method, based on the MIMO (Multiple Input/Multiple Output) system model and taking the first order reflection into consideration, enables accurate analysis of the arrangement of the LED lamps for any room. The studies show that under the optimal arrangement the uniformity of illumination is improved from 0.55 to 0.86, which guarantees that users can get almost equal lighting effects, no matter where they locate themselves. At the same time, the RMS delay spread distribution which is used to evaluate the inter-signal-interference (ISI) is analyzed, and the simulation results indicate that the optimal arrangement also can improve the communication quality by reducing the fluctuation of the RMS delay spread.

The Intracellular Mechanism of Action on Escherichia coli of BF2-A/C, Two Analogues of the Antimicrobial Peptide Buforin 2

Gang Hao,Yong-Hui Shi,Ya-Li Tang,Guo-Wei Le 한국미생물학회 2013 The journal of microbiology Vol.51 No.2

In the present study, the antimicrobial peptides BF2-A and BF2-C, two analogues of Buforin 2, were chemically synthesized and the activities were assayed. To elucidate the bactericidal mechanism of BF2-A/C and their different antimicrobial activities, the influence of peptides to E. coli cell membrane and targets of intracellular action were researched. Obviously, BF2-A and BF2-C did not induce the influx of PI into the E. coli cells, indicating nonmemebrane permeabilizing killing action. The FITC-labeled BF2-A/C could penetrate the E. coli cell membrane and BF2-C penetrated the cells more efficiently. Furthermore, BF2-A/C could bind to DNA and RNA respectively, and the affinity of BF2-C to DNA was powerful at least over 4 times than that of BF2-A. The present results implied that BF2-A and BF2-C inhibited the cellular functions by binding to DNA and RNA of cells after penetrating the cell membranes, resulting in the rapid cell death. The structure-activity relationship analysis of BF2-A/C revealed that the cell-penetrating efficiency and the affinity ability to DNA were critical factors for determining the antimicrobial potency of both peptides. The more efficient cellpenetrating and stronger affinity to DNA caused that BF2-C displayed more excellent antimicrobial activity and rapid killing kinetics than BF2-A.

FBW7 Upregulation Enhances Cisplatin Cytotoxicity in Non-small Cell Lung Cancer Cells

Yu, Hao-Gang,Wei, Wei,Xia, Li-Hong,Han, Wei-Li,Zhao, Peng,Wu, Sheng-Jun,Li, Wei-Dong,Chen, Wei Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

Introduction: Lung cancer is extremely harmful to human health and has one of the highest worldwide incidences of all malignant tumors. Approximately 80% of lung cancers are classified as non-small cell lung cancers (NSCLCs). Cisplatin-based multidrug chemotherapy regimen is standard for such lesions, but drug resistance is an increasing problem. F-box/WD repeat-containing protein 7 (FBW7) is a member of the F-box protein family that regulates cell cycle progression, and cell growth and differentiation. FBW7 also functions as a tumor suppressor. Methods: We used cell viability assays, Western blotting, and immunofluorescence combined with siRNA interference or plasmid transfection to investigate the underlying mechanism of cisplatin resistance in NSCLC cells. Results: We found that FBW7 upregulation significantly increased cisplatin chemosensitivity and that cells expressing low levels of FBW7, such as NCI-H1299 cells, have a mesenchymal phenotype. Furthermore, siRNA-mediated silencing or plasmid-mediated upregulation of FBW7 resulted in altered epithelial-mesenchymal transition (EMT) patterns in NSCLC cells. These data support a role for FBW7 in regulating the EMT in NSCLC cells. Conclusion: FBW7 is a potential drug target for combating drug resistance and regulating the EMT in NSCLC cells.

RON and MET Co-overexpression Are Significant Pathological Characteristics of Poor Survival and Therapeutic Targets of Tyrosine Kinase Inhibitors in Triple-Negative Breast Cancer

Tian-Hao Weng,Min-Ya Yao,Xiang-Ming Xu,Chen-Yu Hu,Shu-Hao Yao,Yi-Zhi Liu,Zhi-Gang Wu,Tao-Ming Tang,Pei-Fen Fu,Ming-Hai Wang,Hang-Ping Yao 대한암학회 2020 Cancer Research and Treatment Vol.52 No.3

Purpose Triple-negative breast cancer (TNBC) is highly malignant and has poor prognosis and a high mortality rate. The lack of effective therapy has spurred our investigation of new targets for treating this malignant cancer. Here, we identified RON (macrophage-stimulating 1 receptor) and MET (MET proto-oncogene, receptor tyrosine kinase) as a prognostic biomarker and therapeutic targets for potential TNBC treatment. Materials and Methods We analyzed RON and MET expression in 187 primary TNBC clinical samples with immunohistochemistry. We validated the targeted therapeutic effects of RON and MET in TNBC using three tyrosine kinase inhibitors (TKIs): BMS-777607, INCB28060, and tivantinib. The preclinical therapeutic efficacy of the TKIs was mainly estimated using a TNBC xenograft model. Results Patients with TNBC had widespread, abnormal expression of RON and MET. There was RON overexpression, MET overexpression, and RON and MET co-overexpression in 63 (33.7%), 63 (33.7%), and 43 cases (23.0%), respectively, which had poor prognosis and short survival. In vivo, the TKI targeting RON ant MET inhibited the activation of the downstream signaling molecules, inhibited TNBC cell migration and proliferation, and increased TNBC cell apoptosis; in the xenograft model, they significantly inhibited tumor growth and shrank tumor volumes. The TKI targeting RON and Met, such as BMS-777607 and tivantinib, yielded stronger anti-tumor effects than INCB28060. Conclusion RON and MET co-overexpression can be significant pathological characteristics in TNBC for poor prognosis. TKIs targeting RON and MET have stronger drug development potential for treating TNBC.

Encapsulation, Pharmacokinetics and Tissue Distribution of Interferon α-2b Liposomes after Intramuscular Injection to Rats

Hao Li,Li Yang,Gang Cheng,Hong-Yan Wei,Qun Zeng 대한약학회 2011 Archives of Pharmacal Research Vol.34 No.6

The aim of the present study was to investigate the effect of liposome-encapsulation and liposome-size on the in vivo pharmacokinetics of interferon α-2b (IFNα-2b) following i.m. administration to rats, and whether there was any liver-targeting of these liposomes. Since liposomes of different sizes can be obtained by homogenization, the effect of homogenization on the IFNα-2b activity was also investigated. The pharmacokinetics of IFNα-2b solution (12.8 μg/kg) and IFNα-2b prepared in liposomes, including three mean sizes of 172 nm (12.2 μg/kg), 113 nm (44.2, 11.0, and 2.8 μg/kg, respectively), and 82 nm (13.1 μg/kg), were studied after a single i.m. dose to rats. Compared to a solution of IFNα-2b. administration of liposomal IFNα-2b resulted in a significantly prolonged t_max, the apparent elimination half life (t_(1/2β)) was 2.3 times longer, both AUC_(0-∞) and MRT_(0-∞) were also clearly enhanced and greater accumulation was obtained in the liver (p < 0.05). The AUC_(0-∞) increased proportionally to the administered dose of IFNα-2b liposomes. Moreover, the size of liposomes ranging from 82 nm to 172 nm had no significant difference on the pharmacokinetic behavior in vivo (p > 0.05). In sum, compared with the free form, IFNα-2b encapsulated in liposomes can alter strikingly the pharmacokinetics properties following i.m. injection and if a liposomal size ranging from 82 nm to 172 nm was used, consistent pharmacokinetic behaviors of IFNα-2b was exhibited. The liposomal formulation apparently targeted the liver, offering a potential advantage for hepatitis B treatment.

Association of Four ERCC1 and ERCC2 SNPs with Survival of Bone Tumour Patients

Hao, Ting,Feng, Wei,Zhang, Jie,Sun, Yong-Jian,Wang, Gang Asian Pacific Journal of Cancer Prevention 2012 Asian Pacific journal of cancer prevention Vol.13 No.8

Aim: SNPs of ERCC1 and ERCC2 genes have been found to be associated with response to platinum therapy in different clinical settings. In the current study, we investigated the relationship of SNPs in ERCC1 and ERCC2 to cisplain response and survival in osteosarcoma patients. Methods: 267 consecutive patients diagnosed with osteosarcoma between January 2003 to January 2005 were followed up until the end of January 2010. ERCC1 Asn118Asn, ERCC1 Gln504Lys, ERCC2 Asp312Asn and ERCC2 Lys751Gln polymorphisms were detected based upon the Sequenom MassARRAY platform.Results: For ERCC1 Asn118Asn, the variant genotype T/T was strongly significantly associated with a higher event free survival when compared with the wild-type C/C, with an adjusted OR (95% CI) of 0.39 (0.14-0.95). ERCC2 751 A/A genotype showed increased event free survival of osteosarcoma (HR=0.44; 95%CI=0.10-0.87). However, we did not find significant association of ERCC1 Gln504Lys and ERCC2 Asp312Asn polymorphisms with prognosis of osteosarcoma. Conclusions: We first report associations of four SNPs, ERCC1 Asn118Asn, ERCC1 Gln504Lys, ERCC2 Asp312Asn and ERCC2 Lys751Gln, with risk of death from osteosarcoma in a Chinese population, indicating ERCC1 118T/T and ERCC2 A/A may be used as surrogate markers for clinical outcome of osteosarcoma treatmetn with cisplain.

Summer Precipitation Changes over the Yangtze River Valley and North China: Simulations from CMIP3 Models

Gang Zeng,Wei-Chyung Wang,Caiming Shen,Zhixin Hao 한국기상학회 2014 Asia-Pacific Journal of Atmospheric Sciences Vol.50 No.3

We present a study of summer precipitation changes overthe Yangtze River Valley (YRV) and North China (NC) simulatedfrom 20 models of the CMIP3 (phase 3 of the Coupled Model IntercomparisonProject). It is found that the LASG-FGOALS-g1.0 (fgoals)model has the highest ability in simulating both the interannualvariability of individual regions and the seesaw pattern of the tworegions observed during the past few decades. Analyses of atmosphericcirculations indicate that the variability in precipitation isclosely associated with the 850 hPa meridional winds over the tworegions. Wetness in the YRV and dryness in NC are corresponding tostrong meridional wind gradient and weak meridional wind overthese two regions, respectively. The ability of a coupled generalcirculation model (CGCM) to simulate precipitation changes in theYRV and NC depends on how well the model reproduces bothobserved associations of precipitation with overlying meridionalwinds and observed meridional wind features in summer. Analysis offuture precipitation changes over the two regions projected by thefgoals model under the IPCC scenarios B1 and A1B suggests asignificant increase of 7-15% for NC after 2040s due to thestrengthened meridional winds, and a slight increase over the YRVdue to less significant intensification of the Mei-yu front.

Exploring the role and mechanisms of diallyl trisulfide and diallyl disulfide in chronic constriction-induced neuropathic pain in rats

( Gang Wang ),( Yan Yang ),( Chunfeng Wang ),( Jianzhong Huang ),( Xiao Wang ),( Ying Liu ),( Hao Wang ) 대한통증학회 2020 The Korean Journal of Pain Vol.33 No.3

Background: Garlic oil is a rich source of organosulfur compounds including diallyl disulfide and diallyl trisulfide. There have been studies showing the neuroprotective actions of these organosulfur compounds. However, the potential of these organosulfur compounds in neuropathic pain has not been explored. The present study was aimed at investigating the pain attenuating potential of diallyl disulfide and diallyl trisulfide in chronic constriction injury (CCI)-induced neuropathic pain in rats. The study also explored their pain-attenuating mechanisms through modulation of H₂S, brain-derived neurotrophin factor (BDNF) and nuclear factor erythroid 2-related factor 2 (Nrf2). Methods: The rats were subjected to CCI injury by ligating the sciatic nerve in four places. The development of neuropathic pain was measured by assessing mechanical hyperalgesia (Randall-Selittotest), mechanical allodynia (Von Frey test), and cold allodynia (acetone drop test) on 14th day after surgery. Results: Administration of diallyl disulfide (25 and 50 mg/kg) and diallyl trisulfide (20 and 40 mg/kg) for 14 days led to a significant reduction in pain in CCI-subjected rats. Moreover, treatment with these organosulfur compounds led to the restoration of H₂S, BDNF and Nrf2 levels in the sciatic nerve and dorsal root ganglia. Coadministration of ANA-12 (BDNF blocker) abolished pain attenuating actions as well as BDNF and the Nrf2 restorative actions of diallyl disulfide and diallyl trisulfide, without modulating H₂S levels. Conclusions: Diallyl disulfide and diallyl trisulfide have the potential to attenuate neuropathic pain in CCI-subjected rats possibly through activation of H₂S-BDNF-Nrf2 signaling pathway.

ISAR 2-D Imaging of Uniformly Rotating Targets via Matching Pursuit

Gang Li,Hao Zhang,Xiqin Wang,Xiang-Gen Xia IEEE 2012 IEEE transactions on aerospace and electronic syst Vol.48 No.2

<P>An algorithm based on matching pursuit (MP) is proposed for inverse synthetic aperture radar (ISAR) two-dimensional (2-D) imaging of uniformly rotating targets. The ISAR echo is decomposed into many subsignals that are generated by discretizing spatial domain and synthesizing the ISAR data for every discretized spatial position. The subsignals that indeed contribute to the ISAR echo are selected by the MP, and their coefficients represent the superresolution image. The target rotation rate is estimated by combining MP with maximum contrast search.</P>