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Xin QQ, Xu HF, Liang CY, Han ZG, Zeng G, Xu P, Wang M, Lü F. [Cost-effectiveness analysis of HIV testing strategy in hospitals from 2006 to 2010 in Guangzhou]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2013; 47:547-551. [PMID: 24113106] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
OBJECTIVE To evaluate the cost effectiveness of HIV testing strategy in hospitals from 2006 to 2010 in Guangzhou. METHODS According to the HIV test strategy costs and the number of HIV patients found in Guangzhou, following aspects were calculated as the total cost of HIV testing strategy in hospitals from 2006 to 2010 of Guangzhou, the cost of finding each HIV patient, and the cost of obtaining one quality adjusted life year (QALY) using Markov model. RESULTS The total HIV test strategy costs increased from 11 106.98 thousand Yuan to 25 105.58 thousand Yuan, and 4599 HIV positive patients were found due to this strategy. The cost-effectiveness of HIV testing were different in hospitals from 2006 to 2010 in Guangzhou. The lowest cost-effectiveness ratio of HIV testing strategy was 11 810 Yuan per HIV positive patient, the highest was 23 510 Yuan, and the average was 16 070 Yuan. According to the Markov model result, 7.2855 QALYs could be gained per HIV patient on average via HIV testing strategy in 113 hospitals in Guangzhou, and the cost of obtaining one QALY was 2210 Yuan. CONCLUSION The cost effectiveness ratio of HIV testing strategy in hospitals in Guangzhou was significantly lower than the standard of WHO recommended, and it was cost-effective to carry out the HIV testing strategy in Guangzhou.
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Wang P, Zeng G, Gan R, Wang J, Zha H. Structure-Sensitive Superpixels via Geodesic Distance. Int J Comput Vis 2012. [DOI: 10.1007/s11263-012-0588-6] [Citation(s) in RCA: 112] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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Masutani K, Zeng G, Randhawa P. Severe acute T cell and antibody-mediated rejection in ectopic kidney allografts with or without mouse polyomavirus infection. Am J Transplant 2012; 12:3161-2. [PMID: 22974172 DOI: 10.1111/j.1600-6143.2012.04239.x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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Saba L, Molinari F, Meiburger KM, Piga M, Zeng G, Rajendra Achraya U, Nicolaides A, Suri JS. What is the correct distance measurement metric when measuring carotid ultrasound intima-media thickness automatically? INT ANGIOL 2012; 31:483-489. [PMID: 22990512] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
AIM The aims of this study were: 1) to analyze the interobserver carotid intima-media thickness (CIMT) variability using three different measurement metrics on large multi-institutional databases; 2) to evaluate the three kinds of metrics when comparing completely automated CIMT measurement (Auto Edge CIMT) to two manually derived CIMT (manual CIMT). METHODS Two expert sonographers manually analyzed 665 carotid B-Mode ultrasound images collected from five institutions and using four different scanners. The two readers traced the lumen-intima (LI) and media-adventitia (MA) interfaces. The manual CIMT was computed from the LI/MA tracings by using three different distance measurement metrics: the Hausdorff, the PolyLine, and the Centerline distance metrics. The LI/MA tracings of a completely automated method we previously developed were then compared to manual CIMT. RESULTS The average CIMT values of Readers 1 and 2 were 1.904±0.650 mm and 1.421±0.394 using Hausdorff, 0.808±0.269 mm and 0.790±0.227 mm using Polyline, and 0.762±0.266 mm and 0.782±0.228 mm using Centerline, respectively. The correlation coefficients were 0.14 (0.07-0.22) for Hausdorff, 0.77 (0.74-0.80) for Polyline, and 0.82 (0.79-0.84) for Centerline. The variation coefficients (CV) were equal to 46.4% (Hausdorff), 2.6 % (Polyline), and 14.1% (Centerline). The Auto Edge CIMT values were: 1.655±0.676 mm using Hausdorff, 0.808±0.282 mm using Polyline, and 0.776±0.275 mm using Centerline. CONCLUSION Centerline and Polyline yield very close results and are clinically suitable distance measurement techniques for computing the CIMT from LI/MA profiles.
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Tan Y, Yang H, Wu J, Yang X, Zhang Y, Zeng G, Zhang X. [The sub-microsecond pulser applied for electroporation effect]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2012; 29:615-619. [PMID: 23016402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
A sub-microsecond pulse generation applied for electroporation effects of tumor cell is presented in this paper. The principle of the generator is that the expected pulse waveform is intercepted from the RC discharge curve by controlling the on-off states of two IGBT modules with a synchronous controller. Experimental tests indicate that the generator can produce adjustable pulse waveform parameters with 0.5-3.5kV amplitude, 300-800 ns pulse duration, 1-400Hz repetition frequency rate, and it is suitable for the study of the electroporation effect experiments.
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Annis SL, Zeng G, Wu X, Macpherson M. Poster - Thur Eve - 54: A software solution for ongoing DVH quality assurance in radiation therapy. Med Phys 2012; 39:4635. [PMID: 28516715 DOI: 10.1118/1.4740162] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
PURPOSE A program has been developed in MATLAB for use in quality assurance of treatment planning of radiation therapy. It analyzes patient DVH files and compiles dose volume data for review, trending, comparison and analysis. MATERIAL AND METHODS Patient DVH files are exported from the Eclipse treatment planning system and saved according to treatment sites and date. Currently analysis is available for 4 treatment sites; Prostate, Prostate Bed, Lung, and Upper GI, with two functions for data report and analysis: patient-specific and organ-specific. The patient-specific function loads one patient DVH file and reports the user-specified dose volume data of organs and targets. These data can be compiled to an external file for a third party analysis. The organ-specific function extracts a requested dose volume of an organ from the DVH files of a patient group and reports the statistics over this population. A graphical user interface is utilized to select clinical sites, function and structures, and input user's requests. RESULTS We have implemented this program in planning quality assurance at our center. The program has tracked the dosimetric improvement in GU sites after VMAT was implemented clinically. It has generated dose volume statistics for different groups of patients associated with technique or time range. CONCLUSION This program allows reporting and statistical analysis of DVH files. It is an efficient tool for the planning quality control in radiation therapy.
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Fu P, Hughes J, Zeng G, Hanook S, Orem J, Mwanda OW, Remick SC. A comparative investigation of methods for longitudinal data with limits of detection through a case study. Stat Methods Med Res 2012; 25:153-66. [PMID: 22504231 DOI: 10.1177/0962280212444800] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The statistical analysis of continuous longitudinal data may be complicated since quantitative levels of bioassay cannot always be determined. Values beyond the limits of detection (LOD) in the assays may not be observed and thus censored, rendering complexity to the analysis of such data. This article examines how both left-censoring and right censoring of HIV-1 plasma RNA measurements, collected for the study on AIDS-related Non-Hodgkin’s lymphoma (AR-NHL) in East Africa, affects the quantification of viral load and explores the natural history of viral load measurements over time in AR-NHL patients receiving anticancer chemotherapy. Data analyses using Monte Carlo EM algorithm (MCEM) are compared to analyses where the LOD or LOD/2 (left censoring) value is substituted for the censored observations, and also to other methods such as multiple imputation, and maximum likelihood estimation for censored data (generalized Tobit regression). Simulations are used to explore the sensitivity of the results to changes in the model parameters. In conclusion, the antiretroviral treatment was associated with a significant decrease in viral load after controlling the effects of other covariates. A simulation study with finite sample size shows MCEM is the least biased method and the estimates are least sensitive to the censoring mechanism.
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Molinari F, Meiburger KM, Zeng G, Saba L, Rajendra Acharya U, Famiglietti L, Georgiou N, Nicolaides A, Sriswan Mamidi R, Kuper H, Suri JS. Automated carotid IMT measurement and its validation in low contrast ultrasound database of 885 patient Indian population epidemiological study: results of AtheroEdge™ Software. INT ANGIOL 2012; 31:42-53. [PMID: 22330624 PMCID: PMC3504971] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
AIM The aim of this paper was to demonstrate the usage of an automated computer-based IMT measurement system called - CALEX 3.0 (a class of patented AtheroEdge™ software) on a low contrast and low resolution image database acquired during an epidemiological study from India. The image contrast was very low with pixel density of 12.7 pixels/mm. Further, to demonstrate the accuracy and reproducibility of the AtheroEdge™ software system we compared it with the manual tracings of a vascular surgeon--considered as a gold standard. METHODS We automatically measured the IMT value of 885 common carotid arteries in longitudinal B-Mode images. CALEX 3.0 consisted of a stage for the automatic recognition of the carotid artery and an IMT measurement modulus made of a fuzzy K-means classifier. Performance was assessed by measuring the system accuracy and reproducibility against manual tracings by experts. RESULTS CALEX 3.0 processed all the 885 images of the dataset (100% success). The average automated obtained IMT measurement by CALEX 3.0 was 0.407±0.083 mm compared with 0.429 ± 0.052 mm for the manual tracings, which led to an IMT bias of 0.022±0.081mm. The IMT measurement accuracy (0.022 mm) was comparable to that obtained on high-resolution images and the reproducibility (0.081 mm) was very low and suitable to clinical application. The Figure-of-Merit defined as the percent agreement between the computer-estimated IMT and manually measured IMT for CALEX 3.0 was 94.7%. CONCLUSION CALEX 3.0 had a 100% success in processing low contrast/low-resolution images. CALEX 3.0 is the first technique, which has led to high accuracy and reproducibility on low-resolution images acquired during an epidemiological study. We propose CALEX 3.0 as a generalized framework for IMT measurement on large datasets.
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Fu P, Panneerselvam A, Clifford B, Dowlati A, Ma PC, Zeng G, Halmos B, Leidner RS. Simpson's paradox - aggregating and partitioning populations in health disparities of lung cancer patients. Stat Methods Med Res 2012; 24:937-48. [PMID: 22246415 DOI: 10.1177/0962280211434179] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
It is well known that non-small cell lung cancer (NSCLC) is a heterogeneous group of diseases. Previous studies have demonstrated genetic variation among different ethnic groups in the epidermal growth factor receptor (EGFR) in NSCLC. Research by our group and others has recently shown a lower frequency of EGFR mutations in African Americans with NSCLC, as compared to their White counterparts. In this study, we use our original study data of EGFR pathway genetics in African American NSCLC as an example to illustrate that univariate analyses based on aggregation versus partition of data leads to contradictory results, in order to emphasize the importance of controlling statistical confounding. We further investigate analytic approaches in logistic regression for data with separation, as is the case in our example data set, and apply appropriate methods to identify predictors of EGFR mutation. Our simulation shows that with separated or nearly separated data, penalized maximum likelihood (PML) produces estimates with smallest bias and approximately maintains the nominal value with statistical power equal to or better than that from maximum likelihood and exact conditional likelihood methods. Application of the PML method in our example data set shows that race and EGFR-FISH are independently significant predictors of EGFR mutation.
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Zeng G, Wu ZY. [Evaluation on health economics regarding provider-initiated AIDS testing and counseling strategy]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2012; 33:115-118. [PMID: 22575124] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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Jones DT, Machulda MM, Vemuri P, McDade EM, Zeng G, Senjem ML, Gunter JL, Przybelski SA, Avula RT, Knopman DS, Boeve BF, Petersen RC, Jack CR. Age-related changes in the default mode network are more advanced in Alzheimer disease. Neurology 2011; 77:1524-31. [PMID: 21975202 DOI: 10.1212/wnl.0b013e318233b33d] [Citation(s) in RCA: 255] [Impact Index Per Article: 19.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
OBJECTIVE To investigate age-related default mode network (DMN) connectivity in a large cognitively normal elderly cohort and in patients with Alzheimer disease (AD) compared with age-, gender-, and education-matched controls. METHODS We analyzed task-free-fMRI data with both independent component analysis and seed-based analysis to identify anterior and posterior DMNs. We investigated age-related changes in connectivity in a sample of 341 cognitively normal subjects. We then compared 28 patients with AD with 56 cognitively normal noncarriers of the APOE ε4 allele matched for age, education, and gender. RESULTS The anterior DMN shows age-associated increases and decreases in fontal lobe connectivity, whereas the posterior DMN shows mainly age-associated declines in connectivity throughout. Relative to matched cognitively normal controls, subjects with AD display an accelerated pattern of the age-associated changes described above, except that the declines in frontal lobe connectivity did not reach statistical significance. These changes survive atrophy correction and are correlated with cognitive performance. CONCLUSIONS The results of this study indicate that the DMN abnormalities observed in patients with AD represent an accelerated aging pattern of connectivity compared with matched controls.
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Liu Y, Tian X, Leitner WW, Aldridge ME, Zheng J, Yu Z, Restifo NP, Weiss R, Scheiblhofer S, Xie C, Sun R, Cheng G, Zeng G. Polymeric structure and host Toll-like receptor 4 dictate immunogenicity of NY-ESO-1 antigen in vivo. J Biol Chem 2011; 286:37077-84. [PMID: 21900253 DOI: 10.1074/jbc.m111.280123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In search of intrinsic factors that contribute to the distinctively strong immunogenicity of a non-mutated cancer/testis antigen, we found that NY-ESO-1 forms polymeric structures through disulfide bonds. NY-ESO-1 binding to immature dendritic cells was dependent on its polymeric structure and involved Toll-like receptor-4 (TLR4) on the surface of immature dendritic cells in mouse and human. Gene gun-delivered plasmid encoding the wild-type NY-ESO-1 readily induced T cell-dependent antibody (Ab) responses in wild-type C57BL/10 mice but not TLR4-knock-out C57BL/10ScNJ mice. Disrupting polymeric structures of NY-ESO-1 by cysteine-to-serine (Cys-to-Ser) substitutions lead to diminished immunogenicity and altered TLR4-dependence in the induced Ab response. To demonstrate its adjuvant effect, NY-ESO-1 was fused with a major mugwort pollen allergen Art v 1 and a tumor-associated antigen, carbonic anhydrase 9. Plasmid DNA vaccines encoding the fusion genes generated robust immune responses against otherwise non-immunogenic targets in mice. Polymeric structure and TLR4 may play important roles in rendering NY-ESO-1 immunogenic and thus serve as a potent molecular adjuvant. NY-ESO-1 thus represents the first example of a cancer/testis antigen that is a also damage-associated molecular pattern.
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Wu M, Yang H, Zhang Y, Zheng X, Zeng G, Tan Y, Sun Y, Zou H. [Electric pulse duration and windows effect of nuclear envelope]. SHENG WU YI XUE GONG CHENG XUE ZA ZHI = JOURNAL OF BIOMEDICAL ENGINEERING = SHENGWU YIXUE GONGCHENGXUE ZAZHI 2011; 28:602-606. [PMID: 21774232] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Nuclear envelope voltages of T cells were analyzed with a lumped circuitry for cells in combination with frequency domain power density of Gaussian pulses and monocycle pulses. According to the differences in geometric and electric parameters between normal and malignant T cells, circuitry analysis was performed. Theoretical evaluations indicated that apoptosis of malignant T cells was of feasibility, which could be applied in cancer therapy. The evaluations were in accord with the published experimental findings.
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Zeng G, Murphy J, Zhan Q, Wang Y, Wang Y, Tsao J, McGowan T, MacPherson M. 1324 poster RAPID DOUBLE ARC REPLACES DYNAMIC IMRT IN PROSTATE BED AND STOMACH RADIATION THERAPY. Radiother Oncol 2011. [DOI: 10.1016/s0167-8140(11)71446-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
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Xie C, Kim HJ, Haw JG, Kalbasi A, Gardner BK, Li G, Rao J, Chia D, Liong M, Punzalan RR, Marks LS, Pantuck AJ, de la Taille A, Wang G, Mukouyama H, Zeng G. A novel multiplex assay combining autoantibodies plus PSA has potential implications for classification of prostate cancer from non-malignant cases. J Transl Med 2011; 9:43. [PMID: 21504557 PMCID: PMC3102624 DOI: 10.1186/1479-5876-9-43] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 04/19/2011] [Indexed: 12/18/2022] Open
Abstract
Background The lack of sufficient specificity and sensitivity among conventional cancer biomarkers, such as prostate specific antigen (PSA) for prostate cancer has been widely recognized after several decades of clinical implications. Autoantibodies (autoAb) among others are being extensively investigated as potential substitute markers, but remain elusive. One major obstacle is the lack of a sensitive and multiplex approach for quantifying autoAb against a large panel of clinically relevant tumor-associated antigens (TAA). Methods To circumvent preparation of phage lysates and purification of recombinant proteins, we identified B cell epitopes from a number of previously defined prostate cancer-associated antigens (PCAA). Peptide epitopes from cancer/testis antigen NY-ESO-1, XAGE-1b, SSX-2,4, as well as prostate cancer overexpressed antigen AMACR, p90 autoantigen, and LEDGF were then conjugated with seroMAP microspheres to allow multiplex measurement of autoAb present in serum samples. Moreover, simultaneous quantification of autoAb plus total PSA was achieved in one reaction, and termed the "A+PSA" assay. Results Peptide epitopes from the above 6 PCAA were identified and confirmed that autoAb against these peptide epitopes reacted specifically with the full-length protein. A pilot study was conducted with the A+PSA assay using pre-surgery sera from 131 biopsy-confirmed prostate cancer patients and 121 benign prostatic hyperplasia and/or prostatitis patients. A logistic regression-based A+PSA index was found to enhance sensitivities and specificities over PSA alone in distinguishing prostate cancer from nonmalignant cases. The A+PSA index also reduced false positive rate and improved the area under a receiver operating characteristic curve. Conclusions The A+PSA assay represents a novel platform that integrates autoAb signatures with a conventional cancer biomarker, which may aid in the diagnosis and prognosis of prostate cancer and others.
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Sun X, Lu F, Wu Z, Poundstone K, Zeng G, Xu P, Zhang D, Liu K, Liau A. Evolution of information-driven HIV/AIDS policies in China. Int J Epidemiol 2011; 39 Suppl 2:ii4-13. [PMID: 21113036 PMCID: PMC2992621 DOI: 10.1093/ije/dyq217] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
Background As China continues to commit to universal access to HIV/AIDS prevention, treatment and care services, its HIV/AIDS policies have become increasingly information driven. We review China’s key national-level HIV/AIDS policies and discuss policy gaps and challenges ahead. Methods We conducted a desk review of key national-level policies that have had a major impact on China’s HIV/AIDS epidemic, and examined recent epidemiological data relevant to China’s HIV response. Results National-level policies that have had a major impact on China’s HIV/AIDS response include: ‘Four Frees and One Care’; 5-year action plans; and HIV/AIDS regulation. These landmark policies have facilitated massive scaling up of services over the past decade. For example, the number of drug users provided with methadone maintenance treatment significantly increased from 8116 in 2005 to 241 975 in 2009; almost a 30-fold increase. The ‘Four Frees and One Care’ policy has increased the number of people living with AIDS on anti-retroviral treatment from some 100 patients in 2003 to over 80 000 in 2009. However, stigma and discrimination remains major obstacles for people living with HIV/AIDS trying to access services. Conclusions China’s current national policies are increasingly information driven and responsive to changes in the epidemic. However, gaps remain in policy implementation, and new policies are needed to meet emerging challenges.
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Liu Y, Jiang T, Zeng G, Huang Y, Li X. Rheological Properties of Neat and Calcium Carbonate Particles Filled Polypropylene Blends under Axial Vibration Force Field. INT POLYM PROC 2011. [DOI: 10.3139/217.2392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Structures, working mechanism, data collecting and processing methods of the self-made multifunctional all-electronic rheometer for polymer composites were introduced in detail. The validity of this equipment was proved by deriving the apparent shear viscosity expression under axial vibration condition and comparing the results obtained from both this self-made rheometer and Rosand Rh7D capillary rheometer at steady state. With this equipment, the effects of calcium carbonate weight fraction, particle size and vibration parameters on apparent shear viscosity of calcium carbonate filled propylene composites were investigated. The results show that: the apparent shear viscosity of the composites increases with the filled particle concentration. However, it is seldom affected by particle size within certain a range of shear rate. While the apparent shear viscosity increases with the decrease of particle size at moderate shear rate. Besides, the apparent shear viscosity declines rapidly with the increasing vibration amplitude. However it exhibits a cosinoidal or sinusoidal trend as vibration frequency increases and peaks at the resonant frequency of the composites.
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Zeng G, Xu C, Liu Y, Qu J, Jiang T. Lower Temperature Plasticizing and Extrusion of Polymer in Spherical Screw Extruder under Vibration Force Field. INT POLYM PROC 2011. [DOI: 10.3139/217.2372] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Abstract
Physical and mathematical model for polymer plasticizing in proposed electromagnetic dynamic spherical screw extruder were developed to explore polymer plasticizing and molding mechanism at lower temperature under vibration force field. Polymer plasticizing mechanism was studied by deriving the mathematical expressions of energy consumed and the polymer flow. The energy consumed in polymer plasticizing was depicted in terms of vibrating dissipation, polymer deformation, shear and friction energy. LDPE was used as an objective material and extruded by the extruder with the electromagnetic excitation and spherical screw. The experimental results show the good agreement with theoretical calculations. Both of them show that: Polymer processing temperature and energy consumption decrease significantly while the plasticizing rate is increased over 60% by introducing the vibration force field. The research offers experimental and theoretical references as well as the evaluation method for optimizing the polymer processing parameters and designing the vibration induced equipment.
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Zhang XF, Tan X, Zeng G, Misse A, Singh S, Kim Y, Klaunig JE, Monga SPS. Conditional beta-catenin loss in mice promotes chemical hepatocarcinogenesis: role of oxidative stress and platelet-derived growth factor receptor alpha/phosphoinositide 3-kinase signaling. Hepatology 2010; 52:954-65. [PMID: 20583210 PMCID: PMC3100799 DOI: 10.1002/hep.23747] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
UNLABELLED Activation of beta-catenin, the central effector of the canonical Wnt pathway and a recognized oncogene, has been implicated in hepatocellular carcinoma. We examined N-nitrosodiethylamine (DEN)-induced tumorigenesis in hepatic beta-catenin conditional knockout mice (beta-cat KO). Male beta-cat KO and age- and sex-matched littermate controls were given a single intraperitoneal DEN injection and followed for 6-12 months for hepatic tumors. Hepatic tumors were characterized for histology, proliferation, apoptosis, oxidative stress, and specific proteins by way of western blot, immunohistochemistry, and coprecipitation studies. For in vivo tumor intervention studies, specific inhibitors were administered intraperitoneally or through drinking water. Intriguingly, beta-cat KO mice showed a paradoxical increase in susceptibility to DEN-induced tumorigenesis. This accelerated tumorigenesis is due to increased injury and inflammation, unrestricted oxidative stress, fibrosis, and compensatory increase in hepatocyte proliferation secondary to platelet-derived growth factor receptor alpha (PDGFRalpha)/phosphoinositide 3-kinase (PIK3CA)/Akt activation and c-Myc overexpression. In vitro suppression of beta-catenin expression in hepatoma cells led to enhanced PDGFRalpha expression, which was abrogated in the presence of nuclear factor kappaB (NF-kappaB) inhibitor. Daily treatment of 6-month-old DEN-exposed beta-cat KO with PDGFRalpha inhibitor dramatically reduced tumor numbers and size. Inclusion of N-acetyl-L-cysteine, a known antioxidant and NF-kappaB inhibitor, in the drinking water led to complete abolition of tumorigenesis in DEN-exposed beta-cat KO. CONCLUSION Loss of beta-catenin impairs the liver's ability to counteract DEN-induced oxidative stress and enhances tumorigenesis through PDGFRalpha/PIK3CA/Akt signaling. Blockade of PDGFRalpha or oxidative stress dramatically affects beta-catenin-deficient tumorigenesis. Also, hepatoma cells use PDGFRalpha/PIK3CA signaling as an escape mechanism following beta-catenin suppression, and their sequential suppression profoundly impedes tumor proliferation.
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Zhu M, Tan N, Zhu H, Zeng G, He W, Yu B, Chen X. Anti-sports anaemia effects of verbascoside and martynoside in mice. Int J Sports Med 2010; 31:537-41. [PMID: 20556696 DOI: 10.1055/s-0030-1254115] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
This paper aims to investigate the effects of verbascoside and martynoside isolated from PEDICULARIS DOLICHOCYMBA on sports anaemia. Forty mice were divided into four groups: Group R (control group, nonsupplemented and maintained at rest), Group E (nonsupplemented and undergoing exercise), Group VE (supplemented with verbascoside 10 mg/kg per day and undergoing exercise), and Group ME (supplemented with martynoside 10 mg/kg per day and undergoing exercise). After 5 weeks intensive swimming exercises, we measured the RBC count, the hemoglobin concentration, the hematocrit (Hct), the mean corpuscular hemoglobin concentration (MCHC) and the mean corpuscular hemoglobin (MCH). We studied the shapes of RBC and measured the plasma malonyldialdehyde (MDA). We found Group E showed lower RBC, hemoglobin and Hct levels, higher MCHC, MCH, plasma MDA levels and the abnormally shaped RBCs percentage than Groups R, VE and ME. Group ME showed lower RBC and Hct levels, higher MCH, plasma MDA levels and the abnormally shaped RBCs percentage than Group VE. The results indicated that verbascoside and martynoside have the potential of antagonizing sports anaemia, the mechanism of this effect might be related to preventing RBC from free radical damage. Moreover, verbascoside was found to be more active than martynoside.
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Zeng G, Do A, Lawrence K, Wang Y, McGowan T, MacPherson M. SU-GG-J-70: Prostate Bed Localization in Post-Prostatectomy Image-Guided Radiation Therapy. Med Phys 2010. [DOI: 10.1118/1.3468294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Lee JM, Garon EB, Baratelli F, Schaue D, Pak PS, Wallace WD, Suh R, Abtin F, Zeng G, Dubinett SM. Phase I trial of CCL21 gene modified dendritic cells in non-small cell lung cancer. J Clin Oncol 2010. [DOI: 10.1200/jco.2010.28.15_suppl.tps157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Feng N, Lü F, Zeng G, Nan L, Wang XY, Xu P, Zhang JX, Zhang SE. [Acceptability and related factors on male circumcision among young men with Yi ethnicity in one county of Sichuan province.]. ZHONGHUA LIU XING BING XUE ZA ZHI = ZHONGHUA LIUXINGBINGXUE ZAZHI 2010; 31:281-285. [PMID: 20510053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
OBJECTIVE To explore the acceptability of male circumcision (MC) as an HIV prevention method and its related factors among young men of Yi ethnicity in Liangshan prefecture. METHODS 446 young men were selected in Butuo county, under stratified sampling method. Using a self-designed questionnaire, face to face interviews were taken to collect HIV-related risk behaviors, knowledge and acceptability of MC. RESULTS After an introduction on MC by interviewers, 40.6% of the interviewees expressed their willingness in taking this surgery. The main reason for acceptance was that they felt this surgery might reduce the risk of HIV infection (90.1%). For those who refused to take this surgery, most of them thought it was too sensitive and embarrassing (52.5%) and were afraid that it might affect their procreation ability. Data from logistic regression analysis indicated that the acceptability of MC was associated with the following factors as:age, income, experience of commercial sexual behavior. They also felt that messages related to male MC surgery could reduce the risk of being infected with HIV/STDs or induce pain when having sexual intercourse, or it might cause partial infection after surgery, or they might be mocked at if taking the surgery. CONCLUSION It is the prerequisite in helping young people of Yi ethnicity to have a good understanding on MC as for Yi people, embarrassment attitudes towards sex appears to be one of the big obstacles against the popularization of this surgery. The operation should be provided by trained and professional doctors, with standardized procedure, in good sanitary conditions and free for service.
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Zeng G, Xiao Y, Xu P, Feng N, Jin CR, Lü F. [Evaluation of effect of community-based HIV/AIDS interventions among men who have sex with men in eighteen cities, China]. ZHONGHUA YU FANG YI XUE ZA ZHI [CHINESE JOURNAL OF PREVENTIVE MEDICINE] 2009; 43:977-980. [PMID: 20137519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
OBJECTIVE To evaluate the effect of a community-based intervention project among men who have sex with men (MSM) after two-year implementation. METHODS Comprehensive interventions among MSM in 18 cities of seven provinces were conducted. The pre-intervention questionnaire was conducted in September 2006 and 5178 subjects were investigated through snowball method. In May 2007, post-questionnaire was conducted and 5460 subjects were investigated through snowball or accompanied recommendation method. For each subject, a questionnaire was completed, including basic information, HIV/AIDS knowledge, behaviours and intervention status. At the same time, 5 ml intravenous blood sample was collected to detect HIV infection and evaluated the intervention effect. RESULTS After two-year implementation, the awareness rate of HIV/AIDS knowledge increased from 76.0% (3933/5178) in 2006 to 90.5% (4943/5460) in 2008 (chi(2) = 451.786, P < 0.001); the rate of condom use in the last anal sex with males increased from 58.0% (2382/4105) to 76.7% (3643/4750) (chi(2) = 215.491, P < 0.01); the rate of consistent condom use in the last six months increased from 28.2% (1163/4118) to 44.5% (2114/4753) (chi(2) = 264.606, P < 0.01); the proportion of MSM receiving HIV antibody test increased from 18.8% (973/5170) to 39.1% (2136/5454) (chi(2) = 530.181, P < 0.01); and the HIV infection rate increased from 2.3% (118/5178) to 5.0% (271/5427) (chi(2) = 47.613, P < 0.01). CONCLUSION The MSM community-based intervention project achieved some good results after two-year implementation and contributed to an increase in HIV/AIDS knowledge and safe sex.
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Nejak-Bowen KN, Zeng G, Tan X, Cieply B, Monga SP. Beta-catenin regulates vitamin C biosynthesis and cell survival in murine liver. J Biol Chem 2009; 284:28115-28127. [PMID: 19690176 PMCID: PMC2788862 DOI: 10.1074/jbc.m109.047258] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2009] [Indexed: 12/18/2022] Open
Abstract
Because the Wnt/beta-catenin pathway plays multiple roles in liver pathobiology, it is critical to identify gene targets that mediate such diverse effects. Here we report a novel role of beta-catenin in controlling ascorbic acid biosynthesis in murine liver through regulation of expression of regucalcin or senescence marker protein 30 and L-gulonolactone oxidase. Reverse transcription-PCR, Western blotting, and immunohistochemistry demonstrate decreased regucalcin expression in beta-catenin-null livers and greater expression in beta-catenin overexpressing transgenic livers, HepG2 hepatoma cells (contain constitutively active beta-catenin), regenerating livers, and in hepatocellular cancer tissues that exhibit beta-catenin activation. Interestingly, coprecipitation and immunofluorescence studies also demonstrate an association of beta-catenin and regucalcin. Luciferase reporter and chromatin immunoprecipitation assays verified a functional TCF-4-binding site located between -163 and -157 (CTTTGCA) on the regucalcin promoter to be critical for regulation by beta-catenin. Significantly lower serum ascorbate levels were observed in beta-catenin knock-out mice secondary to decreased expression of regucalcin and also of L-gulonolactone oxidase, the penultimate and last (also rate-limiting) steps in the synthesis of ascorbic acid, respectively. These mice also show enhanced basal hepatocyte apoptosis. To test if ascorbate deficiency secondary to beta-catenin loss and regucalcin decrease was contributing to apoptosis, beta-catenin-null hepatocytes or regucalcin small interfering RNA-transfected HepG2 cells were cultured, which exhibited significant apoptosis that was alleviated by the addition of ascorbic acid. Thus, through regucalcin and L-gulonolactone oxidase expression, beta-catenin regulates vitamin C biosynthesis in murine liver, which in turn may be one of the mechanisms contributing to the role of beta-catenin in cell survival.
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