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Jiang R, Zhan L, Osei E. SU-E-T-538: Lung SBRT Dosimetric Comparison of 3D Conformal and RapidArc Planning. Med Phys 2015. [DOI: 10.1118/1.4924900] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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Zhan L, Liu Y, Zhou J, Ye J, Thompson PM. Boosting Classification Accuracy of Diffusion MRI Derived Brain Networks for the Subtypes of Mild Cognitive Impairment Using Higher Order Singular Value Decomposition. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING 2015; 2015:131-135. [PMID: 26413202 PMCID: PMC4578228 DOI: 10.1109/isbi.2015.7163833] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Mild cognitive impairment (MCI) is an intermediate stage between normal aging and Alzheimer's disease (AD), and around 10-15% of people with MCI develop AD each year. More recently, MCI has been further subdivided into early and late stages, and there is interest in identifying sensitive brain imaging biomarkers that help to differentiate stages of MCI. Here, we focused on anatomical brain networks computed from diffusion MRI and proposed a new feature extraction and classification framework based on higher order singular value decomposition and sparse logistic regression. In tests on publicly available data from the Alzheimer's Disease Neuroimaging Initiative, our proposed framework showed promise in detecting brain network differences that help in classifying early versus late MCI.
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Zhan L, Jahanshad N, Faskowitz J, Zhu D, Prasad G, Martin NG, de Zubicaray GI, McMahon KL, Wright MJ, Thompson PM. HERITABILITY OF BRAIN NETWORK TOPOLOGY IN 853 TWINS AND SIBLINGS. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING 2015; 2015:449-453. [PMID: 26413204 PMCID: PMC4578220 DOI: 10.1109/isbi.2015.7163908] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Anatomical brain networks change throughout life and with diseases. Genetic analysis of these networks may help identify processes giving rise to heritable brain disorders, but we do not yet know which network measures are promising for genetic analyses. Many factors affect the downstream results, such as the tractography algorithm used to define structural connectivity. We tested nine different tractography algorithms and four normalization methods to compute brain networks for 853 young healthy adults (twins and their siblings). We fitted genetic structural equation models to all nine network measures, after a normalization step to increase network consistency across tractography algorithms. Probabilistic tractography algorithms with global optimization (such as Probtrackx and Hough) yielded higher heritability statistics than "greedy" algorithms (such as FACT) which process small neighborhoods at each step. Some global network measures (probtrackx-derived GLOB and ST) showed significant genetic effects, making them attractive targets for genome-wide association studies.
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An FP, Balantekin AB, Band HR, Beriguete W, Bishai M, Blyth S, Butorov I, Cao GF, Cao J, Chan YL, Chang JF, Chang LC, Chang Y, Chasman C, Chen H, Chen QY, Chen SM, Chen X, Chen X, Chen YX, Chen Y, Cheng YP, Cherwinka JJ, Chu MC, Cummings JP, de Arcos J, Deng ZY, Ding YY, Diwan MV, Draeger E, Du XF, Dwyer DA, Edwards WR, Ely SR, Fu JY, Ge LQ, Gill R, Gonchar M, Gong GH, Gong H, Grassi M, Gu WQ, Guan MY, Guo XH, Hackenburg RW, Han GH, Hans S, He M, Heeger KM, Heng YK, Hinrichs P, Hor YK, Hsiung YB, Hu BZ, Hu LM, Hu LJ, Hu T, Hu W, Huang EC, Huang H, Huang XT, Huber P, Hussain G, Isvan Z, Jaffe DE, Jaffke P, Jen KL, Jetter S, Ji XP, Ji XL, Jiang HJ, Jiao JB, Johnson RA, Kang L, Kettell SH, Kramer M, Kwan KK, Kwok MW, Kwok T, Lai WC, Lau K, Lebanowski L, Lee J, Lei RT, Leitner R, Leung A, Leung JKC, Lewis CA, Li DJ, Li F, Li GS, Li QJ, Li WD, Li XN, Li XQ, Li YF, Li ZB, Liang H, Lin CJ, Lin GL, Lin PY, Lin SK, Lin YC, Ling JJ, Link JM, Littenberg L, Littlejohn BR, Liu DW, Liu H, Liu JL, Liu JC, Liu SS, Liu YB, Lu C, Lu HQ, Luk KB, Ma QM, Ma XY, Ma XB, Ma YQ, McDonald KT, McFarlane MC, McKeown RD, Meng Y, Mitchell I, Monari Kebwaro J, Nakajima Y, Napolitano J, Naumov D, Naumova E, Nemchenok I, Ngai HY, Ning Z, Ochoa-Ricoux JP, Olshevski A, Patton S, Pec V, Peng JC, Piilonen LE, Pinsky L, Pun CSJ, Qi FZ, Qi M, Qian X, Raper N, Ren B, Ren J, Rosero R, Roskovec B, Ruan XC, Shao BB, Steiner H, Sun GX, Sun JL, Tam YH, Tang X, Themann H, Tsang KV, Tsang RHM, Tull CE, Tung YC, Viren B, Vorobel V, Wang CH, Wang LS, Wang LY, Wang M, Wang NY, Wang RG, Wang W, Wang WW, Wang X, Wang YF, Wang Z, Wang Z, Wang ZM, Webber DM, Wei HY, Wei YD, Wen LJ, Whisnant K, White CG, Whitehead L, Wise T, Wong HLH, Wong SCF, Worcester E, Wu Q, Xia DM, Xia JK, Xia X, Xing ZZ, Xu JY, Xu JL, Xu J, Xu Y, Xue T, Yan J, Yang CC, Yang L, Yang MS, Yang MT, Ye M, Yeh M, Yeh YS, Young BL, Yu GY, Yu JY, Yu ZY, Zang SL, Zeng B, Zhan L, Zhang C, Zhang FH, Zhang JW, Zhang QM, Zhang Q, Zhang SH, Zhang YC, Zhang YM, Zhang YH, Zhang YX, Zhang ZJ, Zhang ZY, Zhang ZP, Zhao J, Zhao QW, Zhao Y, Zhao YB, Zheng L, Zhong WL, Zhou L, Zhou ZY, Zhuang HL, Zou JH. Search for a light sterile neutrino at Daya Bay. PHYSICAL REVIEW LETTERS 2014; 113:141802. [PMID: 25325631 DOI: 10.1103/physrevlett.113.141802] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Indexed: 06/04/2023]
Abstract
A search for light sterile neutrino mixing was performed with the first 217 days of data from the Daya Bay Reactor Antineutrino Experiment. The experiment's unique configuration of multiple baselines from six 2.9 GW(th) nuclear reactors to six antineutrino detectors deployed in two near (effective baselines 512 m and 561 m) and one far (1579 m) underground experimental halls makes it possible to test for oscillations to a fourth (sterile) neutrino in the 10(-3) eV(2)<|Δm(41)(2) |< 0.3 eV(2) range. The relative spectral distortion due to the disappearance of electron antineutrinos was found to be consistent with that of the three-flavor oscillation model. The derived limits on sin(2) 2θ(14) cover the 10(-3) eV(2) ≲ |Δm(41)(2)| ≲ 0.1 eV(2) region, which was largely unexplored.
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An F, Balantekin A, Band H, Beriguete W, Bishai M, Blyth S, Butorov I, Cao G, Cao J, Chan Y, Chang J, Chang L, Chang Y, Chasman C, Chen H, Chen Q, Chen S, Chen X, Chen X, Chen Y, Chen Y, Cheng Y, Cherwinka J, Chu M, Cummings J, de Arcos J, Deng Z, Ding Y, Diwan M, Draeger E, Du X, Dwyer D, Edwards W, Ely S, Fu J, Ge L, Gill R, Gonchar M, Gong G, Gong H, Gu W, Guan M, Guo X, Hackenburg R, Han G, Hans S, He M, Heeger K, Heng Y, Hinrichs P, Hor Y, Hsiung Y, Hu B, Hu L, Hu L, Hu T, Hu W, Huang E, Huang H, Huang X, Huber P, Hussain G, Isvan Z, Jaffe D, Jaffke P, Jen K, Jetter S, Ji X, Ji X, Jiang H, Jiao J, Johnson R, Kang L, Kettell S, Kramer M, Kwan K, Kwok M, Kwok T, Lai W, Lau K, Lebanowski L, Lee J, Lei R, Leitner R, Leung A, Leung J, Lewis C, Li D, Li F, Li G, Li Q, Li W, Li X, Li X, Li Y, Li Z, Liang H, Lin C, Lin G, Lin P, Lin S, Lin Y, Ling J, Link J, Littenberg L, Littlejohn B, Liu D, Liu H, Liu J, Liu J, Liu S, Liu Y, Lu C, Lu H, Luk K, Ma Q, Ma X, Ma X, Ma Y, McDonald K, McFarlane M, McKeown R, Meng Y, Mitchell I, Monari Kebwaro J, Nakajima Y, Napolitano J, Naumov D, Naumova E, Nemchenok I, Ngai H, Ning Z, Ochoa-Ricoux J, Olshevski A, Patton S, Pec V, Peng J, Piilonen L, Pinsky L, Pun C, Qi F, Qi M, Qian X, Raper N, Ren B, Ren J, Rosero R, Roskovec B, Ruan X, Shao B, Steiner H, Sun G, Sun J, Tam Y, Tang X, Themann H, Tsang K, Tsang R, Tull C, Tung Y, Viren B, Vorobel V, Wang C, Wang L, Wang L, Wang M, Wang N, Wang R, Wang W, Wang W, Wang X, Wang Y, Wang Z, Wang Z, Wang Z, Webber D, Wei H, Wei Y, Wen L, Whisnant K, White C, Whitehead L, Wise T, Wong H, Wong S, Worcester E, Wu Q, Xia D, Xia J, Xia X, Xing Z, Xu J, Xu J, Xu J, Xu Y, Xue T, Yan J, Yang C, Yang L, Yang M, Yang M, Ye M, Yeh M, Yeh Y, Young B, Yu G, Yu J, Yu Z, Zang S, Zeng B, Zhan L, Zhang C, Zhang F, Zhang J, Zhang Q, Zhang Q, Zhang S, Zhang Y, Zhang Y, Zhang Y, Zhang Y, Zhang Z, Zhang Z, Zhang Z, Zhao J, Zhao Q, Zhao Y, Zhao Y, Zheng L, Zhong W, Zhou L, Zhou Z, Zhuang H, Zou J. Independent measurement of the neutrino mixing angleθ13via neutron capture on hydrogen at Daya Bay. Int J Clin Exp Med 2014. [DOI: 10.1103/physrevd.90.071101] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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Gao EJ, Xu XY, Zhu MC, Yan HL, Fu H, Wang H, Zhan L, Yao Q, Li MY, Jiang MP. A novel Cd(II) complex with 1,3-bis(4-Pyridyl)propane: Synthesis, crystal structure, and interaction with DNA. RUSS J COORD CHEM+ 2014. [DOI: 10.1134/s107032841408003x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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An FP, Balantekin AB, Band HR, Beriguete W, Bishai M, Blyth S, Brown RL, Butorov I, Cao GF, Cao J, Carr R, Chan YL, Chang JF, Chang Y, Chasman C, Chen HS, Chen HY, Chen SJ, Chen SM, Chen XC, Chen XH, Chen Y, Chen YX, Cheng YP, Cherwinka JJ, Chu MC, Cummings JP, de Arcos J, Deng ZY, Ding YY, Diwan MV, Draeger E, Du XF, Dwyer DA, Edwards WR, Ely SR, Fu JY, Ge LQ, Gill R, Gonchar M, Gong GH, Gong H, Gornushkin YA, Gu WQ, Guan MY, Guo XH, Hackenburg RW, Hahn RL, Han GH, Hans S, He M, Heeger KM, Heng YK, Hinrichs P, Hor Y, Hsiung YB, Hu BZ, Hu LJ, Hu LM, Hu T, Hu W, Huang EC, Huang HX, Huang HZ, Huang XT, Huber P, Hussain G, Isvan Z, Jaffe DE, Jaffke P, Jetter S, Ji XL, Ji XP, Jiang HJ, Jiao JB, Johnson RA, Kang L, Kettell SH, Kramer M, Kwan KK, Kwok MW, Kwok T, Lai WC, Lai WH, Lau K, Lebanowski L, Lee J, Lei RT, Leitner R, Leung A, Leung JKC, Lewis CA, Li DJ, Li F, Li GS, Li QJ, Li WD, Li XN, Li XQ, Li YF, Li ZB, Liang H, Lin CJ, Lin GL, Lin SK, Lin YC, Ling JJ, Link JM, Littenberg L, Littlejohn BR, Liu DW, Liu H, Liu JC, Liu JL, Liu SS, Liu YB, Lu C, Lu HQ, Luk KB, Ma QM, Ma XB, Ma XY, Ma YQ, McDonald KT, McFarlane MC, McKeown RD, Meng Y, Mitchell I, Nakajima Y, Napolitano J, Naumov D, Naumova E, Nemchenok I, Ngai HY, Ngai WK, Ning Z, Ochoa-Ricoux JP, Olshevski A, Patton S, Pec V, Peng JC, Piilonen LE, Pinsky L, Pun CSJ, Qi FZ, Qi M, Qian X, Raper N, Ren B, Ren J, Rosero R, Roskovec B, Ruan XC, Shao BB, Steiner H, Sun GX, Sun JL, Tam YH, Tanaka HK, Tang X, Themann H, Trentalange S, Tsai O, Tsang KV, Tsang RHM, Tull CE, Tung YC, Viren B, Vorobel V, Wang CH, Wang LS, Wang LY, Wang LZ, Wang M, Wang NY, Wang RG, Wang W, Wang WW, Wang X, Wang YF, Wang Z, Wang Z, Wang ZM, Webber DM, Wei H, Wei YD, Wen LJ, Whisnant K, White CG, Whitehead L, Wise T, Wong HLH, Wong SCF, Worcester E, Wu Q, Xia DM, Xia JK, Xia X, Xing ZZ, Xu J, Xu JL, Xu JY, Xu Y, Xue T, Yan J, Yang CG, Yang L, Yang MS, Ye M, Yeh M, Yeh YS, Young BL, Yu GY, Yu JY, Yu ZY, Zang SL, Zhan L, Zhang C, Zhang FH, Zhang JW, Zhang QM, Zhang SH, Zhang YC, Zhang YH, Zhang YM, Zhang YX, Zhang ZJ, Zhang ZP, Zhang ZY, Zhao J, Zhao QW, Zhao YB, Zheng L, Zhong WL, Zhou L, Zhou ZY, Zhuang HL, Zou JH. Spectral measurement of electron antineutrino oscillation amplitude and frequency at Daya Bay. PHYSICAL REVIEW LETTERS 2014; 112:061801. [PMID: 24580686 DOI: 10.1103/physrevlett.112.061801] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Indexed: 06/03/2023]
Abstract
A measurement of the energy dependence of antineutrino disappearance at the Daya Bay reactor neutrino experiment is reported. Electron antineutrinos (ν¯(e)) from six 2.9 GW(th) reactors were detected with six detectors deployed in two near (effective baselines 512 and 561 m) and one far (1579 m) underground experimental halls. Using 217 days of data, 41 589 (203 809 and 92 912) antineutrino candidates were detected in the far hall (near halls). An improved measurement of the oscillation amplitude sin(2)2θ(13)=0.090(-0.009)(+0.008) and the first direct measurement of the ν¯(e) mass-squared difference |Δm(ee)2|=(2.59(-0.20)(+0.19))×10(-3) eV2 is obtained using the observed ν¯(e) rates and energy spectra in a three-neutrino framework. This value of |Δm(ee)2| is consistent with |Δm(μμ)2| measured by muon neutrino disappearance, supporting the three-flavor oscillation model.
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Horst JA, Pieper U, Sali A, Zhan L, Chopra G, Samudrala R, Featherstone JDB. Strategic protein target analysis for developing drugs to stop dental caries. Adv Dent Res 2013; 24:86-93. [PMID: 22899687 DOI: 10.1177/0022034512449837] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dental caries is the most common disease to cause irreversible damage in humans. Several therapeutic agents are available to treat or prevent dental caries, but none besides fluoride has significantly influenced the disease burden globally. Etiologic mechanisms of the mutans group streptococci and specific Lactobacillus species have been characterized to various degrees of detail, from identification of physiologic processes to specific proteins. Here, we analyze the entire Streptococcus mutans proteome for potential drug targets by investigating their uniqueness with respect to non-cariogenic dental plaque bacteria, quality of protein structure models, and the likelihood of finding a drug for the active site. Our results suggest specific targets for rational drug discovery, including 15 known virulence factors, 16 proteins for which crystallographic structures are available, and 84 previously uncharacterized proteins, with various levels of similarity to homologs in dental plaque bacteria. This analysis provides a map to streamline the process of clinical development of effective multispecies pharmacologic interventions for dental caries.
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Zhan L, Cheng J, Chang P, Ngo M, Denbesten PK, Hoover CI, Featherstone JDB. Effects of xylitol wipes on cariogenic bacteria and caries in young children. J Dent Res 2012; 91:85S-90S. [PMID: 22699675 DOI: 10.1177/0022034511434354] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
The aim of the study was to investigate the efficacy of the use of xylitol-containing tooth-wipes in preventing dental caries in young children. In a double-blinded randomized controlled clinical trial, 44 mothers with active caries and their 6- to 35-month-old children were randomized to xylitol-wipe or placebo-wipe groups. The children's caries scores were recorded at baseline and 1 year. Salivary levels of mutans streptococci and lactobacilli were enumerated at baseline, 3, 6, and 12 months. Data were analyzed by intent-to-treat modeling with imputation for caries lesions and a linear mixed-effect model for bacterial levels. Significantly fewer children in the xylitol-wipe group had new caries lesions at 1 year compared with those in the placebo-wipe group (P < 0.05). No significant differences between the two groups were observed in levels of mutans streptococci and lactobacilli at all time-points. Daily xylitol-wipe application significantly reduced the caries incidence in young children as compared with wipes without xylitol, suggesting that the use of xylitol wipes may be a useful adjunct for caries control in infants (Clinicaltrials.gov registration number CT01468727).
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Zhan L, Featherstone J, Lo J, Krupansky C, Hoang N, DenBesten P, Huynh T. Clinical Efficacy and Effects of Xylitol Wipes on Bacterial Virulence. Adv Dent Res 2012; 24:117-22. [DOI: 10.1177/0022034512449835] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The aim of the study was to investigate whether xylitol-wipe use in young children prevented caries by affecting bacterial virulence. In a double-blinded randomized controlled clinical trial, 44 mother-child pairs were randomized to xylitol-wipe or placebo-wipe groups. Salivary mutans streptococci levels were enumerated at baseline, 6 months, and one year. Ten mutans streptococci colonies were isolated and genotyped from each saliva sample. Genotype-colonization stability, xylitol sensitivity, and biofilm formation of these isolates were studied. Despite a significant reduction in new caries at one year in the xylitol-wipe group, no significant differences were found between the two groups in levels of mutans streptococci. Children in the xylitol-wipe group had significantly fewer retained genotypes (p = 0.06) and more transient genotypes of mutans streptococci (p = 0.05) than those in the placebo-wipe group. At one year, there was no significant difference in the prevalence of xylitol-resistant genotypes or in biofilm formation ability of mutans streptococci isolates between the two groups. The mechanism of the caries-preventive effect of xylitol-wipe use may be related to the stability of mutans streptococci colonization. Further studies with genomic characterization methods are needed to determine specific gene(s) that account for the caries-preventive effect of xylitol.
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Jiang R, Zhan L, Gopaul D, Osei E. Poster - Thur Eve - 67: Clinical results of deep inspiration breath hold radiation treatment for the left breast patients. Med Phys 2012; 39:4637. [DOI: 10.1118/1.4740175] [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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Zhan L, Jiang R, Osei EK. Poster - Thur Eve - 77: Coordinate transformation from DICOM to DOSXYZnrc. Med Phys 2012; 39:4639-4640. [PMID: 28516630 DOI: 10.1118/1.4740186] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
DICOM format is the de facto standard for communications between therapeutic and diagnostic modalities. A plan generated by a treatment planning system (TPS) is often exported to DICOM format. BEAMnrc/DOSXYZnrc is a widely used Monte Carlo (MC) package for beam and dose simulations in radiotherapy. It has its own definition for beam orientation, which is not in compliance with the one defined in DICOM standard. Dose simulations using TPS generated plans require transformation of beam orientations to DOSXYZnrc coordinate system (c.s.) after extracting the necessary parameters from DICOM RP files. The transformation is nontrivial. There have been two studies for the coordinate transformations. The transformation equation sets derived have been helpful to BEAMnrc/DOSXYZnrc users. However, both the transformation equation sets are complex mathematically and not easy to program. In this study, we derive a new set of transformation equations, which are more compact, better understandable, and easier for computational implementation. The derivation of polar angle θ and azimuthal angle φ is similar to the existing studies by applying a series of rotations to a vector in DICOM patient c.s. The derivation of beam rotation Φcol for DOSXYZnrc, however, is different. It is obtained by a direct combination of the actual collimator rotation with the projection of the couch rotation to the collimator rotating plane. Verification of the transformation has been performed using clinical plans created with Eclipse. The comparison between Eclipse and MC results show exact geometrical agreement for field placements, together with good agreement in dose distributions.
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Zhan L, Schaly B, Jiang R, Osei EK. Sci-Thur AM: Planning - 12: Comparative study of SBRT lung dose calculation using Eclipse and Monte Carlo. Med Phys 2012; 39:4621. [PMID: 28516566 DOI: 10.1118/1.4740097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
Abstract
Stereotactic Body Radiation Therapy (SBRT) is an option for early stage non-small cell lung cancer treatment. In SBRT treatment, high biological effective dose is delivered to the patient within a small number of fractions. High level of confidence in accuracy is required in the entire treatment procedure, from patient setup, tumour delineation, treatment simulation and planning, to the final dose delivery. SBRT lung treatment utilizes small fields that are incident on large tissue inhomogeneities within the patient. It is difficult for commercially available treatment planning systems (TPS) to model the lack of charged particle equilibrium and the dose near tissue-lung interfaces accurately. The Monte Carlo (MC) technique calculates the dose distribution from the first principles thereby providing a feasible tool for verifying the dose distribution computed from TPS. In this study, we compared the SBRT dose distribution between Eclipse 8.9 and BEAMnrc/DOSXYZnrc for both conformal and RapidArc plans. Calculation results for five clinical SBRT conformal lung plans were compared. Eclipse and MC results for each plan showed good agreement in dose received by organs at risk. MC simulation predicted uniformly hotter or similar PTV coverage for three cases with tumor either small or attached to the chest wall. When tumor is inside lung and at relatively medium to larger size for SBRT, MC predicted lower PTV coverage. The variation in dose coverage may depend on the tumour size and its position within the lung. Dose comparison for RapidArc plans shows similar dependence.
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An FP, Bai JZ, Balantekin AB, Band HR, Beavis D, Beriguete W, Bishai M, Blyth S, Boddy K, Brown RL, Cai B, Cao GF, Cao J, Carr R, Chan WT, Chang JF, Chang Y, Chasman C, Chen HS, Chen HY, Chen SJ, Chen SM, Chen XC, Chen XH, Chen XS, Chen Y, Chen YX, Cherwinka JJ, Chu MC, Cummings JP, Deng ZY, Ding YY, Diwan MV, Dong L, Draeger E, Du XF, Dwyer DA, Edwards WR, Ely SR, Fang SD, Fu JY, Fu ZW, Ge LQ, Ghazikhanian V, Gill RL, Goett J, Gonchar M, Gong GH, Gong H, Gornushkin YA, Greenler LS, Gu WQ, Guan MY, Guo XH, Hackenburg RW, Hahn RL, Hans S, He M, He Q, He WS, Heeger KM, Heng YK, Hinrichs P, Ho TH, Hor YK, Hsiung YB, Hu BZ, Hu T, Hu T, Huang HX, Huang HZ, Huang PW, Huang X, Huang XT, Huber P, Isvan Z, Jaffe DE, Jetter S, Ji XL, Ji XP, Jiang HJ, Jiang WQ, Jiao JB, Johnson RA, Kang L, Kettell SH, Kramer M, Kwan KK, Kwok MW, Kwok T, Lai CY, Lai WC, Lai WH, Lau K, Lebanowski L, Lee J, Lee MKP, Leitner R, Leung JKC, Leung KY, Lewis CA, Li B, Li F, Li GS, Li J, Li QJ, Li SF, Li WD, Li XB, Li XN, Li XQ, Li Y, Li ZB, Liang H, Liang J, Lin CJ, Lin GL, Lin SK, Lin SX, Lin YC, Ling JJ, Link JM, Littenberg L, Littlejohn BR, Liu BJ, Liu C, Liu DW, Liu H, Liu JC, Liu JL, Liu S, Liu X, Liu YB, Lu C, Lu HQ, Luk A, Luk KB, Luo T, Luo XL, Ma LH, Ma QM, Ma XB, Ma XY, Ma YQ, Mayes B, McDonald KT, McFarlane MC, McKeown RD, Meng Y, Mohapatra D, Morgan JE, Nakajima Y, Napolitano J, Naumov D, Nemchenok I, Newsom C, Ngai HY, Ngai WK, Nie YB, Ning Z, Ochoa-Ricoux JP, Oh D, Olshevski A, Pagac A, Patton S, Pearson C, Pec V, Peng JC, Piilonen LE, Pinsky L, Pun CSJ, Qi FZ, Qi M, Qian X, Raper N, Rosero R, Roskovec B, Ruan XC, Seilhan B, Shao BB, Shih K, Steiner H, Stoler P, Sun GX, Sun JL, Tam YH, Tanaka HK, Tang X, Themann H, Torun Y, Trentalange S, Tsai O, Tsang KV, Tsang RHM, Tull C, Viren B, Virostek S, Vorobel V, Wang CH, Wang LS, Wang LY, Wang LZ, Wang M, Wang NY, Wang RG, Wang T, Wang W, Wang X, Wang X, Wang YF, Wang Z, Wang Z, Wang ZM, Webber DM, Wei YD, Wen LJ, Wenman DL, Whisnant K, White CG, Whitehead L, Whitten CA, Wilhelmi J, Wise T, Wong HC, Wong HLH, Wong J, Worcester ET, Wu FF, Wu Q, Xia DM, Xiang ST, Xiao Q, Xing ZZ, Xu G, Xu J, Xu J, Xu JL, Xu W, Xu Y, Xue T, Yang CG, Yang L, Ye M, Yeh M, Yeh YS, Yip K, Young BL, Yu ZY, Zhan L, Zhang C, Zhang FH, Zhang JW, Zhang QM, Zhang K, Zhang QX, Zhang SH, Zhang YC, Zhang YH, Zhang YX, Zhang ZJ, Zhang ZP, Zhang ZY, Zhao J, Zhao QW, Zhao YB, Zheng L, Zhong WL, Zhou L, Zhou ZY, Zhuang HL, Zou JH. Observation of electron-antineutrino disappearance at Daya Bay. PHYSICAL REVIEW LETTERS 2012; 108:171803. [PMID: 22680853 DOI: 10.1103/physrevlett.108.171803] [Citation(s) in RCA: 124] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2012] [Indexed: 05/23/2023]
Abstract
The Daya Bay Reactor Neutrino Experiment has measured a nonzero value for the neutrino mixing angle θ(13) with a significance of 5.2 standard deviations. Antineutrinos from six 2.9 GWth reactors were detected in six antineutrino detectors deployed in two near (flux-weighted baseline 470 m and 576 m) and one far (1648 m) underground experimental halls. With a 43,000 ton-GWth-day live-time exposure in 55 days, 10,416 (80,376) electron-antineutrino candidates were detected at the far hall (near halls). The ratio of the observed to expected number of antineutrinos at the far hall is R=0.940±0.011(stat.)±0.004(syst.). A rate-only analysis finds sin(2)2θ(13)=0.092±0.016(stat.)±0.005(syst.) in a three-neutrino framework.
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Featherstone JDB, White JM, Hoover CI, Rapozo-Hilo M, Weintraub JA, Wilson RS, Zhan L, Gansky SA. A randomized clinical trial of anticaries therapies targeted according to risk assessment (caries management by risk assessment). Caries Res 2012; 46:118-29. [PMID: 22472515 PMCID: PMC3362266 DOI: 10.1159/000337241] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2011] [Revised: 01/27/2012] [Accepted: 01/27/2012] [Indexed: 11/19/2022] Open
Abstract
This randomized parallel group clinical trial assessed whether combined antibacterial and fluoride therapy benefits the balance between caries pathological and protective factors. Eligible, enrolled adults (n = 231), with 1-7 baseline cavitated teeth, attending a dental school clinic were randomly assigned to a control or intervention group. Salivary mutans streptococci (MS), lactobacilli (LB), fluoride (F) level, and resulting caries risk status (low or high) assays were determined at baseline and every 6 months. After baseline, all cavitated teeth were restored. An examiner masked to group conducted caries exams at baseline and 2 years after completing restorations. The intervention group used fluoride dentifrice (1,100 ppm F as NaF), 0.12% chlorhexidine gluconate rinse based upon bacterial challenge (MS and LB), and 0.05% NaF rinse based upon salivary F. For the primary outcome, mean caries increment, no statistically significant difference was observed (24% difference between control and intervention groups, p = 0.101). However, the supplemental adjusted zero-inflated Poisson caries increment (change in DMFS) model showed the intervention group had a statistically significantly 24% lower mean than the control group (p = 0.020). Overall, caries risk reduced significantly in intervention versus control over 2 years (baseline adjusted generalized linear mixed models odds ratio, aOR = 3.45; 95% CI: 1.67, 7.13). Change in MS bacterial challenge differed significantly between groups (aOR = 6.70; 95% CI: 2.96, 15.13) but not for LB or F. Targeted antibacterial and fluoride therapy based on salivary microbial and fluoride levels favorably altered the balance between pathological and protective caries risk factors.
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Leow A, Zhan L, Ajilore O, Gadelkarim J, Zhang A, Arienzo D, Moody T, Feusner J, Kumar A, Thompson P, Altshuler L. MEASURING INTER-HEMISPHERIC INTEGRATION IN BIPOLAR AFFECTIVE DISORDER USING BRAIN NETWORK ANALYSES AND HARDI. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING 2012:5-8. [PMID: 22902926 PMCID: PMC3420952 DOI: 10.1109/isbi.2012.6235470] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Bipolar disorder is characterized by extreme mood swings, including both manic and depressive episodes commonly accompanied by psychosis. Many imaging studies have investigated white matter changes in bipolar illness, and the results have suggested abnormal intra- and inter-hemispheric white matter structures, particularly in the fronto-limbic and callosal systems. However, some inconsistency remains in the literature, and no study to-date has utilized brain network analysis using graph theory. Here, we acquired 64-direction diffusion weighted imaging (DWI) on 25 euthymic bipolar I subjects and 25 gender/age matched healthy subjects. White matter integrity measures were computed and compared in 50 white matter ROIs. The results indicated impaired integrity in the corpus callosum. Guided by this, we constructed whole brain structural connectivity networks using graph theory. We devised brain network metrics (inter-hemispheric path length and efficiency) to further probe inter-hemispheric integration, and demonstrated relatively preserved intra-hemispheric but significantly impaired inter-hemispheric integration in our bipolar subjects.
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Tong M, Kim Y, Zhan L, Sapiro G, Lenglet C, Mueller BA, Thompson PM, Vese LA. A VARIATIONAL MODEL FOR DENOISING HIGH ANGULAR RESOLUTION DIFFUSION IMAGING. PROCEEDINGS. IEEE INTERNATIONAL SYMPOSIUM ON BIOMEDICAL IMAGING 2012:530-533. [PMID: 22902985 PMCID: PMC3420955 DOI: 10.1109/isbi.2012.6235602] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The presence of noise in High Angular Resolution Diffusion Imaging (HARDI) data of the brain can limit the accuracy with which fiber pathways of the brain can be extracted. In this work, we present a variational model to denoise HARDI data corrupted by Rician noise. Numerical experiments are performed on three types of data: 2D synthetic data, 3D diffusion-weighted Magnetic Resonance Imaging (DW-MRI) data of a hardware phantom containing synthetic fibers, and 3D real HARDI brain data. Experiments show that our model is effective for denoising HARDI-type data while preserving important aspects of the fiber pathways such as fractional anisotropy and the orientation distribution functions.
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Qian K, Zhan L, Zhang L, Zhu ZQ, Peng JS, Gu ZC, Hu X, Luo SY, Xia YX. Group velocity manipulation in active fibers using mutually modulated cross-gain modulation: from ultraslow to superluminal propagation. OPTICS LETTERS 2011; 36:2185-2187. [PMID: 21685961 DOI: 10.1364/ol.36.002185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
We propose and experimentally demonstrate the propagation of slow/fast light in an erbium-doped fiber (EDF) using mutually modulated cross-gain modulation. The group velocity of the light signal can be manipulated by the effect of gain cross-saturation modulation by a saturating light at an arbitrary wavelength in the gain bandwidth of the EDF. The ultraslow propagation with a small group velocity of 5.6 × 10⁻³c (c is the light speed in free space) and superluminal propagation with a negative group velocity of -1.1 × 10⁻³c has been observed under different modulation phases.
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Zhan L, Fleck A, Jiang R, Osei E. SU-E-T-729: A Superficial Information Management and Calculation System. Med Phys 2011. [DOI: 10.1118/1.3612691] [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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Jiang R, Zhan L, Gopaul D, Osei E. SU-E-T-615: Clinical Implementation of Deep Inspiration Breath-Hold for Left Breast Cancers Treatment. Med Phys 2011. [DOI: 10.1118/1.3612578] [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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Zhan L, Kerr JR, Lafuente MJ, Maclean A, Chibalina MV, Liu B, Burke B, Bevan S, Nasir J. Altered expression and coregulation of dopamine signalling genes in schizophrenia and bipolar disorder. Neuropathol Appl Neurobiol 2011; 37:206-19. [PMID: 20874815 DOI: 10.1111/j.1365-2990.2010.01128.x] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
INTRODUCTION signalling through dopamine receptors is of critical importance in the brain and is implicated in schizophrenia and bipolar disorder, but its underlying molecular mechanisms remain poorly understood. MATERIALS AND METHODS using a yeast two-hybrid approach, we previously identified 11 novel dopamine receptor-interacting proteins. Here we compare gene expression levels for 17 genes [including all 11 dopamine receptor interacting proteins, all 5 dopamine receptors (DRD1-DRD5) and DARPP-32] by real-time polymerase chain reaction, using prefrontal cortex post mortem brain samples from 33 schizophrenic, 32 bipolar disorder and 34 control subjects. RESULTS the expression of C14ORF28, GNB2L1, MLLT3, DRD2 and DARPP-32 genes was altered in schizophrenia and/or bipolar disorder samples relative to controls (P < 0.05). Hierarchical clustering analysis revealed the expression of these five genes (C14ORF28, GNB2L1, MLLT3, DARPP-32, DRD2) is closely correlated in patients. However, in controls, DRD2 expression in relation to the other genes appears to be very different, suggesting abnormal DRD2 activity is an important trigger in the pathophysiology of schizophrenia and bipolar disorder. CONCLUSIONS our data suggest: (i) C14ORF28, GNB2L1, MLLT3, DRD2 and DARPP-32 are important in the pathogenesis of schizophrenia and bipolar disorder; (ii) these two disorders share common disease-related mechanisms linked to dopamine signalling; (iii) the expression of these genes is closely correlated; and (iv) DRD2 provides the initial trigger in the pathogenesis of these disorders.
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Osei EK, Willick K, Puzzuoli D, Wernik C, Zhan L, Barnett R. Poster - Thur Eve - 55: GRRCC-Monte Carlo Treatment Planning Research Environment (MCTPRE). Med Phys 2010. [DOI: 10.1118/1.3476160] [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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Doméjean S, Zhan L, DenBesten PK, Stamper J, Boyce WT, Featherstone JD. Horizontal transmission of mutans streptococci in children. J Dent Res 2010; 89:51-5. [PMID: 19918090 DOI: 10.1177/0022034509353400] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
It has not been established whether transmission of mutans streptococci occurs between unrelated children older than 4 years of age. The aim of the study was to investigate the possible transmission of mutans streptococci genotypes from child to child in kindergarten. We studied 96 children (ages 5-6 yrs) in three San Francisco Bay Area public schools. Mutans streptococci colonies from each child were isolated from selective culture on Mitis Salivarius Sucrose Bacitracin agar. We used arbitrary primed polymerase chain reactions to determine the mutans streptococci genotypes. Two children (not siblings) in each of the three schools (6%) shared an identical amplitype of S. mutans, unique to each pair. The 19 S. sobrinus amplitypes were found in 12 children, and all were unique to each child. The presence of matching genotypes of S. mutans demonstrates horizontal transmission of this species between unrelated children aged 5-6 years.
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Zhan L, Leow A, Zhu S, Chiang M, Barysheva M, Toga A, McMahon K, de Zubicaray G, Wright M, Thompson P. Analysis of Fiber Reconstruction Accuracy in High Angular Resolution Diffusion Images (HARDI). Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70141-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Leow A, Zhan L, Zhu S, Hageman N, Chiang M, Barysheva M, Toga A, McMahon K, de Zubicaray G, Wright M, Thompson P. Novel Measure of Fiber Integrity based on Q-Ball Imaging and the Tensor Distribution Function avoids Problems with Fractional Anisotropy Measures. Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)70920-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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Zhan L, Leow A, Zhu S, Chiang M, Barysheva M, Toga A, McMahon K, de Zubicaray G, Wright M, Thompson P. Validating the Tensor Distribution Function for Fiber Reconstruction in HARDI (High-Angular Resolution Diffusion Imaging). Neuroimage 2009. [DOI: 10.1016/s1053-8119(09)71225-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Penumathsa SV, Thirunavukkarasu M, Zhan L, Maulik G, Menon VP, Bagchi D, Maulik N. Resveratrol enhances GLUT-4 translocation to the caveolar lipid raft fractions through AMPK/Akt/eNOS signalling pathway in diabetic myocardium. J Cell Mol Med 2009; 12:2350-61. [PMID: 18266981 PMCID: PMC4514113 DOI: 10.1111/j.1582-4934.2008.00251.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Homeostasis of blood glucose by insulin involves stimulation of glucose uptake by translocation of glucose transporter Glut-4 from intracellular pool to the caveolar membrane system. In this study we examined resveratrol (RSV)-mediated Glut-4 translocation in the streptozotocin (STZ)-induced diabetic myocardium. The rats were randomized into three groups: Control (Con), Diabetes Mellitus (DM) (STZ 65 mg/kg b.w., i.p.) & DM + RSV (2.5 mg/kg b.wt. for 2 weeks orally) (RSV). Isolated rat hearts were used as per the experimental model. RSV induced glucose uptake was observed in vitro with H9c2 cardiac myoblast cells. Decreased blood glucose level was observed after 30 days (375 mg/dl) in RSV-treated rats when compared to DM (587 mg/dl). Treatment with RSV demonstrated increased Adenosine Mono Phosphate Kinase (AMPK) phosphorylation compared to DM. Lipid raft fractions demonstrated decreased expression of Glut-4, Cav-3 (0.4, 0.6-fold) in DM which was increased to 0.75-and 1.1-fold on RSV treatment as compared to control. Increased Cav-1 expression (1.4-fold) in DM was reduced to 0.7-fold on RSV treatment. Increased phosphorylation of endothelial Nitric Oxide Synthase (eNOS) & Akt was also observed in RSV compared to DM (P< 0.05). Confocal microscopy and co-immunoprecipitation studies demonstrated decreased association of Glut-4/Cav-3 and increased association of Cav-1/eNOS in DM as compared to control and converse results were obtained on RSV treatment. Our results suggests that the effect of RSV is non-insulin dependent and triggers some of the similar intracellular insulin signalling components in myocardium such as eNOS, Akt through AMPK pathway and also by regulating the caveolin-1 and caveolin-3 status that might play an essential role in Glut-4 translocation and glucose uptake in STZ- induced type-1 diabetic myocardium.
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Leow AD, Zhu S, Zhan L, McMahon K, de Zubicaray GI, Meredith M, Wright MJ, Toga AW, Thompson PM. The tensor distribution function. Magn Reson Med 2009; 61:205-14. [PMID: 19097208 PMCID: PMC2770429 DOI: 10.1002/mrm.21852] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2007] [Accepted: 09/17/2008] [Indexed: 12/31/2022]
Abstract
Diffusion weighted magnetic resonance imaging is a powerful tool that can be employed to study white matter microstructure by examining the 3D displacement profile of water molecules in brain tissue. By applying diffusion-sensitized gradients along a minimum of six directions, second-order tensors (represented by three-by-three positive definite matrices) can be computed to model dominant diffusion processes. However, conventional DTI is not sufficient to resolve more complicated white matter configurations, e.g., crossing fiber tracts. Recently, a number of high-angular resolution schemes with more than six gradient directions have been employed to address this issue. In this article, we introduce the tensor distribution function (TDF), a probability function defined on the space of symmetric positive definite matrices. Using the calculus of variations, we solve the TDF that optimally describes the observed data. Here, fiber crossing is modeled as an ensemble of Gaussian diffusion processes with weights specified by the TDF. Once this optimal TDF is determined, the orientation distribution function (ODF) can easily be computed by analytic integration of the resulting displacement probability function. Moreover, a tensor orientation distribution function (TOD) may also be derived from the TDF, allowing for the estimation of principal fiber directions and their corresponding eigenvalues.
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Loukas M, Diala EZ, Tubbs RS, Zhan L, Rhizek P, Monsekis A, Akiyama M. A review of the distribution of the arterial and venous vasculature of the diaphragm and its clinical relevance. Folia Morphol (Warsz) 2008; 67:159-165. [PMID: 18828095] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The diaphragm is the major respiratory muscle of the body. As it plays such a vital role, a continuous arterial and venous blood supply is of the utmost importance. It is therefore not surprising to find described in the literature a complex system of anastomoses that contributes to the maintenance of this muscle's life-preserving contraction. Understanding the anatomy of the diaphragm and any divergence in its vasculature is literally vital to humanity. In the light of this, we review the literature on the blood supply to the diaphragm, with specific emphasis on the recent description of the inferior phrenic vessels and the superior phrenic artery, summarize the clinical significance of the diaphragmatic vasculature and suggest future avenues of study to further expand on this current body of knowledge.
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Xu E, Li W, Zhan L, Guan G, Wang X, Chen S, Shi Y. Polymorphisms of the lipoprotein lipase gene are associated with atherosclerotic cerebral infarction in the Chinese. Neuroscience 2008; 155:403-8. [PMID: 18590804 DOI: 10.1016/j.neuroscience.2008.06.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 06/01/2008] [Accepted: 06/02/2008] [Indexed: 01/03/2023]
Abstract
BACKGROUND Lipoprotein lipase (LPL), which plays an essential role in plasma lipoprotein metabolism and transportation, appears to be a risk factor for ischemic vascular diseases. Several studies have recently reported the presence of relationship between HindIII, PvuII, Ser447Ter (C-->G) polymorphisms of LPL and ischemic vascular diseases. PURPOSE We first studied the relationship between LPL polymorphisms and the risk of atherosclerotic cerebral infarction (CI) by detecting the frequencies of LPL HindIII, PvuII and Ser447Ter genotypes and combined genotypes in the Chinese. METHODS We recruited 185 CI patients, confirmed by cranial computed tomography or magnetic resonance imaging/angiography, or both, and 186 control subjects. Polymerase chain reaction-restriction fragment length polymorphisms technique was used to detect HindIII, PvuII and Ser447Ter polymorphisms of the LPL gene. RESULTS The frequencies of the H+H+ genotype and H+ allele did not differ between CI and control groups. The frequencies of the P+P+ genotype and P+ allele gene were significantly higher in the CI group (P=0.040, P=0.015). The frequencies of CG+GG genotype and G allele were lower in the CI group (P<0.001, P<0.001). In the CI group, the individuals with P+P+ genotype had a significantly higher level of plasma triglyceride (TG) and a lower level of plasma high density lipoprotein cholesterol (HDL-c). CG+GG genotypes were correlated with significantly higher levels of plasma total cholesterol (TC), HDL-c and low density lipoprotein cholesterol (LDL-c) in the CI group. The frequencies of H+/C and P+/C combined genotypes were higher in the CI group than in controls (P<0.001, P<0.001). The frequency of H+/P+/C combined genotype was significantly higher in the CI group than in controls (P<0.001). CONCLUSIONS Our study suggests that PvuII and Ser447Ter polymorphisms are associated with lipid profile and CI.
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Loukas M, El-Zammar D, Shoja MM, Tubbs RS, Zhan L, Protyniak B, Krutoshinskaya Y. The clinical anatomy of the triangle of Grynfeltt. Hernia 2008; 12:227-31. [DOI: 10.1007/s10029-008-0354-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 02/01/2008] [Indexed: 10/22/2022]
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Thirunavukkarasu M, Addya S, Juhasz B, Pant R, Zhan L, Surrey S, Maulik G, Menon VP, Maulik N. Heterozygous disruption of Flk-1 receptor leads to myocardial ischaemia reperfusion injury in mice: application of affymetrix gene chip analysis. J Cell Mol Med 2008; 12:1284-302. [PMID: 18266966 PMCID: PMC3865673 DOI: 10.1111/j.1582-4934.2008.00269.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
This study addresses an important clinical issue by identifying potential candidates of vascular endothelial growth factor (VEGF) signalling through the Flk-1 receptor that trigger cardioprotective signals under ischaemic stress. Isolated working mouse hearts of both wild-type (WT) and Flk-1+/− were subjected to global ischaemia (I) for 30 min. followed by 2 hrs of reperfusion (R). Flk-1+/− myocardium displayed almost 50% reduction in Flk-1 mRNA as examined by quantitative real-time RT-PCR at the baseline level. Flk-1+/− mouse hearts displayed reduction in left ventricular functional recovery throughout reperfusion (dp/dt 605 versus 884), after 2 hrs (P < 0.05). Coronary (1.9 versus 2.4 ml) and aortic flow (AF) (0.16 versus 1.2 ml) were reduced in Flk-1+/− after 2 hrs of reperfusion. In addition, increased infarct size (38.4%versus 28.41%, P < 0.05) and apoptotic cardiomyocytes (495 versus 213) were observed in Flk-1+/− knockout (KO) mice. We also examined whether ischaemic preconditioning (PC), a novel method to induce cardioprotection against ischaemia reperfusion injury, through stimulating the VEGF signalling pathway might function in Flk-1+/− mice. We found that knocking down Flk-1 resulted in significant reduction in the cardioprotective effect by PC compared to WT. Affymetrix gene chip analysis demonstrated down-regulation of important genes after IR and preconditioning followed by ischaemia reperfusion in Flk-1+/− mice compared to WT. To get insight into the underlying molecular pathways involved in ischaemic PC, we determined the distinct and overlapping biological processes using Ingenuity pathway analysis tool. Independent evidence at the mRNA level supporting the Affymetrix results were validated using real-time RT-PCR for selected down-regulated genes, which are thought to play important roles in cardioprotection after ischaemic insult. In summary, our data indicated for the first time that ischaemic PC modifies genomic responses in heterozygous VEGFR-2/Flk-1 KO mice and abolishes its cardioprotective effect on ischaemic myocardium.
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Hu YL, Zhan L, Zhang ZX, Luo SY, Xia YX. High-resolution measurement of fiber length by using a mode-locked fiber laser configuration. OPTICS LETTERS 2007; 32:1605-7. [PMID: 17572720 DOI: 10.1364/ol.32.001605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
A simple method to precisely measure fiber length has been experimentally demonstrated by using a mode-locked fiber laser configuration. Since the transit time in a cavity is exactly proportional to the cavity length, it is easy to obtain the fiber length from the generation of mode-locked pulses in the fiber laser with a long-range nonlinear optical loop mirror that includes the measured fiber. Our new method has a large measurement range, over hundreds of kilometers, and a high resolution, of the order of centimeters, as well as no measurement dead zone.
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Guo JM, Xiao BX, Lou YR, Wang DH, Yan CH, Zhan L, Zhao WH. The effects of all-trans-retinoic acid on cell cycle and alkaline phosphatase activity in pancreatic cancer cells. Med Chem 2007; 2:457-61. [PMID: 17017984 DOI: 10.2174/157340606778250298] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Pancreatic cancer is one of the tumors with the highest mortality, poorly responding to available chemotherapeutic agents. The objective of this study was to study the anticancer effects of all-trans retinoid acid, a functional form of vitamin A, on pancreatic cancer cells. Human pancreatic cancer MiaPaCa-2 cells were treated with 1, 5, 10, 20, 30, 40 and 50 microM ATRA for 1, 2, 3, 4, 5 or 6 d, respectively. Cell growth was determined by MTT viability assay. The cell cycle distribution and the alkaline phosphatase (ALP) activity were analyzed by flow cytometry and chemical analyzer, respectively. The results show that ATRA significantly inhibited the growth of MiaPaCa-2 cells at 40 and 50 microM. ATRA arrested pancreatic cancer cells at G0/G1 phase. The sub-G1 peak and DNA fragmentation were observed. There were time and dose dependent increases in alkaline phosphatase activity (ALP), an indicator of cell differentiation, upon treatment with ATRA when compared to controls. In conclusion, ATRA has an inhibitory effect on the cell growth of MiaPaCa-2, and its tumor suppressive effect is by means of cell cycle arrest and apoptosis induction.
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Zhan L, Ji JH, Xia J, Luo SY, Xia YX. 160-line multiwavelength generation of linear-cavity self-seeded Brillouin-Erbium fiber laser. OPTICS EXPRESS 2006; 14:10233-10238. [PMID: 19529419 DOI: 10.1364/oe.14.010233] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We have demonstrated a novel multiwavelength Brillouin-erbium fiber laser (BEFL), in which the Brillouin pump is self-excited within the linear cavity, instead of the injection from the external cavity or direct generation in the intracavity. By using this simple scheme, the generation of more than 160 Brillouin Stokes lines has been experimentally demonstrated, which is the largest one achieved in BEFLs to the best of our knowledge. Also, the single longitudinal mode operation and the low noise performance of output wavelength line have been confirmed. Meanwhile, the experiment demonstrates that the BEFL performs good stability on both the operating wavelengths and the output power of each wavelength.
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Penumathsa S, Thirunavukkarasu M, Koneru S, Zhan L, Maulik N. A39. Sildenafil citrate (viagra), a selective phosphodiesterase type 5 inhibitor is a powerful pro-angiogenic agent. J Mol Cell Cardiol 2006. [DOI: 10.1016/j.yjmcc.2006.03.406] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Yi L, Zhan L, Taung C, Luo S, Hu W, Su Y, Xia Y, Leng L. Low noise figure all-optical gain-clamped parallel C+L band Erbium-doped fiber amplifier using an interleaver. OPTICS EXPRESS 2005; 13:4519-4524. [PMID: 19495366 DOI: 10.1364/opex.13.004519] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
A low noise figure (NF), all-optical gain-clamped C+L band erbium-doped fiber amplifier (EDFA) has been demonstrated. A parallel configuration is employed to avoid the crosstalk between the C- and L-band signals. Half of the amplified spontaneous emission from the output signal is filtered by an interleaver and fed back to the parallel EDFA to form lasing cavity. Two lasers in the C- and L-band, respectively, formed in the cavity clamp the C- and L-band signals simultaneously. In the L-band, the double-pass configuration with a fiber Bragg grating is used to improve the gain and NF. Furthermore, co-propagation of the signal and the lasing power leads to a low NF, while the amplified signals are exported separately from the lasing power. Finally, a wide gain-clamping range up to -10dBm and ~5.5dB NF are obtained.
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Song YJ, Zhan L, Ji JH, Su Y, Ye QH, Xia YX. Self-seeded multiwavelength Brillouin-erbium fiber laser. OPTICS LETTERS 2005; 30:486-488. [PMID: 15789711 DOI: 10.1364/ol.30.000486] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
We propose and demonstrate a self-seeded multiwavelength Brillouin-erbium fiber laser with an internally self-excited Brillouin pump, which is achieved by incorporation of a length of single-mode fiber together with a Sagnac loop mirror into a fiber ring cavity. In this simple scheme the Brillouin pump is self-excited in the fiber ring cavity and then used to seed the Brillouin multiwavelength comb in the single-mode fiber. Stable generation of more than 120 Brillouin Stokes wavelengths with relatively uniform amplitudes is demonstrated with this scheme. It is also shown that such a self-seeded Brillouin laser has good stability and repeatability.
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Zhan L, Wang PH, Gu ZC, Luo SY, Xia YX. Amplitude-equalized high-order arbitrary numerator rational harmonic mode-locked pulse generation in fiber-ring lasers using nonlinear polarization rotation. OPTICS EXPRESS 2005; 13:836-841. [PMID: 19494944 DOI: 10.1364/opex.13.000836] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We report the amplitude-equalized high order arbitrary numerator rational harmonic mode-locked (RHMLed) pulse generations based on the technique of nonlinear polarization rotation in the fiber-ring laser. The numerator effect on the amplitude uniformity of RHMLed pulse train is first investigated. It is demonstrated that the high order RHMLed pulse train with uniform amplitude can be achieved by choosing a proper numerator. The pulse amplitude equalization in up to the 10th order RHMLed pulse train is observed when the numerator is equal to 3 instead of 1. It is important that the technique may be useful to generate the high-speed pulse trains with uniform amplitude by using the high order RHMLing technique.
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Zhan L, Li K, Zhang R, Liu Q, Lü CH, Ling L. Improvements of the DA equation for application in hydrogen adsorption at supercritical conditions. J Supercrit Fluids 2004. [DOI: 10.1016/s0896-8446(03)00003-2] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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Guo Q, Zhan L. [Analysis of 136 children with gastrointestinal hemorrhage]. HUNAN YI KE DA XUE XUE BAO = HUNAN YIKE DAXUE XUEBAO = BULLETIN OF HUNAN MEDICAL UNIVERSITY 2001; 26:566-8. [PMID: 12536545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To investigate the pathogeny of children with gastrointestinal hemorrhage, pathogeny distribution and the cause of misdiagnosis before gastrointestinal endoscopy check-up. METHODS We detected 136 children suspected upper gastrointestinal hemorrhage (UGH) by gastrointestinal endoscopy and among them a few cases were diagnosed by celiotomy. RESULTS One hundred and three cases of UGH, 7 cases of small intestine bleeding, and 4 cases of gulping blood syndrome were diagnosed; but the pathogeny of the other 22 cases was not clear. CONCLUSION Gastric ulcer and duodenal ulcer are the common causes of gastrointestinal hemorrhage of elder children and inheriting alimentary canal abnormality leads to gastrointestinal hemorrhage of infants. Some children with bellyache were misdiagnosed as ascariasis or enterospasm. The endoscopy examination should carry on within 48 hours after the latest bleeding to reach the highest positive rate.
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Hannigan MO, Zhan L, Ai Y, Kotlyarov A, Gaestel M, Huang CK. Abnormal migration phenotype of mitogen-activated protein kinase-activated protein kinase 2-/- neutrophils in Zigmond chambers containing formyl-methionyl-leucyl-phenylalanine gradients. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2001; 167:3953-61. [PMID: 11564814 DOI: 10.4049/jimmunol.167.7.3953] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Time-lapsed video microscopy and confocal imaging were used to study the migration of wild-type (WT) and mitogen-activated protein kinase-activated protein kinase 2 (MK2-/-) mouse neutrophils in Zigmond chambers containing fMLP gradients. Confocal images of polarized WT neutrophils showed an intracellular gradient of phospho-MK2 from the anterior to the posterior region of the neutrophils. Compared with WT neutrophils, MK2-/- neutrophils showed a partial loss of directionality but higher migration speed. Immunoblotting experiments showed a lower protein level of p38 mitogen-activated protein kinase and a loss of fMLP-induced extracellular signal-related kinase phosphorylation in MK2-/- neutrophils. These results suggest that MK2 plays an important role in the regulation of neutrophil migration and may also affect other signaling molecules.
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Zhan L, Yue ST, Xue YX, Attele AS, Yuan CS. Effects of qian-kun-nin, a Chinese herbal medicine formulation, on HIV positive subjects: a pilot study. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2001; 28:305-12. [PMID: 11154043 DOI: 10.1142/s0192415x00000362] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Qian-kun-nin is a Chinese herbal formulation considered to have anti-infection, anti-tumor and immuno-enhancing properties. Data from previous investigations showed that qian-kun-nin causes HIV growth inhibition and immunomodulation in vitro, suggesting that this formula has the ability to inhibit HIV and modulate impaired immune functions in humans. We conducted this pilot study to evaluate the anti-retroviral and immunological enhancing effects of this formula on HIV positive subjects. Eight subjects completed the study, receiving oral qian-kun-nin capsules for 24 consecutive weeks in a single blind design. Compared to baseline level, the plasma virus load decreased significantly at the end of week 12 (p < 0.01) and week 24 (p < 0.01), respectively. Four weeks after cessation of qian-kun-nin treatment, plasma virus load was still significantly lower compared to baseline (p < 0.01). Blood CD4 cell counts were increased significantly at the end of the 12th week compared to the baseline level (p < 0.01). No adverse effects were observed, and no significant side effects were recorded in any subjects. These data suggest that qian-kun-nin has therapeutic potential in the treatment of HIV positive patients.
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Hannigan M, Zhan L, Ai Y, Huang CK. Leukocyte-specific gene 1 protein (LSP1) is involved in chemokine KC-activated cytoskeletal reorganization in murine neutrophils in vitro. J Leukoc Biol 2001; 69:497-504. [PMID: 11261799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/19/2023] Open
Abstract
Leukocyte-specific gene 1 protein (LSP1) is a cytoskeletal-associated protein of leukocytes that in vitro cross-links F-actin into extensively branched bundles of mixed polarity. In this study, we examined chemotaxis and superoxide production in neutrophils prepared from wild-type (WT) and Lsp1 knockout mice. Compared to WT neutrophils, Lsp1-/- neutrophils showed impairment in both migration speed and chemotaxis direction during chemokine KC-directed chemotaxis. When examined by confocal microscopy, chemotaxing Lsp1-/- neutrophils showed abnormal morphologies. They had discontinuous primary actin-rich cortexes and large membrane protrusions. When stimulated by phorbol 12-myristate 13-acetate (PMA), Lsp1-/- peritoneal neutrophils produce more superoxide than WT. The data presented suggest that LSP1 plays important roles in the regulation of neutrophil morphology, motility, and superoxide production.
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Huang X, Liu T, Chen Z, Zhan L, Yang J. [Evaluation of cariogenic potential of Streptococcus mutans isolated from caries-free and -active persons: adherence properties to saliva-coated hydroxyapatite]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2000; 18:416-8. [PMID: 12539475] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE In this study, authors used saliva-coated hydroxyapatite to simulate tooth surface in oral cavity to evaluate adherence of different Streptococcus mutans isolated from caries-free and -active persons to saliva-coated hydroxyapatite. METHODS Streptococcus mutans isolated from people with different carious experiences were divided into two groups: the caried-free group (DMFS = 0) including 19 persons and the caries-active group (DMFS > or = 6) including 40 persons. Totally 105 genotype Streptococcus mutans strains were obtains, including 22 strains from the caries-free group, and 83 strains from the caries-active group. The adhering properties of Streptococcus mutans (serotype c) strains were investigated, and different adhering properties were compared between the caries-free group and the caries-active group in order to find the correlationship between carious experiences and adhering properties of Streptococcus mutans. Saliva-coated hydroxyapatite was used to simulated tooth surface in oral cavity. Streptococci mutans were cultured in TPY liquid medium containing 3H-TDR in the same radioactive concentration. After being cultured in an anaerobic incubator for 18 hours, Streptococci mutans were radiolabelled by 3H-TDR. Saliva-coated hydroxyapatite and bacterial liquid(BSA = 0.52) were mixed for 90 minutes. Samples were assayed by using liquid scintillation counter, and binding abilities of strains were evaluated by the count per minute(cpm). RESULTS Binding abilities of strains were significantly different in two groups, Caries-active people harbored more Streptococci mutans with high binding abilities(cpm > 2000) than caries-free people did(P < 0.05). The binding abilities to saliva-coated hydroxyapatite were different between strains of differing genotypes isolated from the same person. Each person always harbored one or two strains with high binding abilities(cpm > 2000) in the caries-active group. CONCLUSION 1. Different genotypes have different adhering properties. 2. In caries-active group, different genotype strains have synergic effects, and adhesion of high binding ability strains cause caries susceptibility. 3. The differences in binding properties of isolates might relate to differences in carious experiences.
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Xiao Y, Liu T, Zhan L, Zhou X. [The effects of tea polyphenols on the adherence of cariogenic bacterium to the collagen in vitro]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2000; 18:340-2. [PMID: 12539657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE In the first phase of our study, it has been proved that tea polyphenols (TP) can inhibit the preliminary adherence of oral cariogenic bacterium to salivary acquired pellicle. This study is carried on to investigate the effects of tea polyphenols on the preliminary adherence of main cariogenic bacterium to collagen I and reveal the anticarious mechanisms of tea polyphenols further. METHODS Tea polyphenols solution was prepared firstly, the concentrations of which were 0.5, 1.0, 2.0 and 4.0 mg/ml. An in-vitro model of experimental pellicle(C-HA) was formed by immerging the hydroxyapatites in 250 micrograms/ml collagen I solution for 1 h. Streptococcus mutans 3a3, Actinomyces viscosus ATCC 19246 and Lactobacillus ATCC 4546 were chosen as the main cariogenic bacterium and radiolabelled by growing them in TPY culture medium supplemented with 3H-thymidine. Two parts of inhibited adherence tests were done with TP-treated C-HA or TP-treated bacterium respectively. In the first one, C-HA was immerged into the TP solution of different concentrations for 1 h before the attachment of bacterium. In the other, the bacterium were mixed with the TP solution for 1 h and then centrifuged and washed before bound to C-HA. KCl buffer solution provided a steady condition to the whole process. Finally, the number of 3H-thymidine-labelled bacterium which attached to C-HA were determined by scintillation counting. RESULTS In both the two parts of this study, tea polyphenols solution, the concentrations of which were changed from 1.0 to 4.0 mg/ml could inhibit the attachments of S. mutans 3a3, A. viscosus ATCC 19246 and Lactobacillus ATCC 4546 to C-HA effectively, and the inhibition rates rose with the increase of the concentrations of TP solution. But the inhibitory effects of 0.5 mg/ml TP solution were inconsistent in different tests. The inhibitory functions of tea polyphenols were so prominent that in some experiments, while the concentrations of TP solution were higher than 2.0 mg/ml, the number of 3H-thymidine-labelled bacterium which attached to C-HA was even less than that of the same bacterium which attached to naked HA. These results showed that TP had the remarkable inhibitory efficiency on the attachments of S. mutans, A. viscosus and Lactobacillus to C-HA. CONCLUSION Tea polyphenols can inhibit the preliminary adherence of Streptococcus mutans, Actinomyces viscosus and Lactobacillus to C-HA effectively. TP may prevent dentine from caries by decreasing the adherence of main cariogenic bacterium to collagen.
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Xiao Y, Liu T, Zhan L, Zhou X. [The effects of tea polyphenols on the adherence of cariogenic bacterium to the salivary acquired pellicle in vitro]. HUA XI KOU QIANG YI XUE ZA ZHI = HUAXI KOUQIANG YIXUE ZAZHI = WEST CHINA JOURNAL OF STOMATOLOGY 2000; 18:336-9. [PMID: 12539656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE It has been proved that tea polyphenols (TP) can inhibit the sucrose-dependent adherence of oral cariogenic bacterium to the tooth surface. This study is carried on to investigate the effects of tea polyphenols on the preliminary adherence of main cariogenic bacterium to salivary acquired pellicle and reveal the anticarious mechanisms of tea polyphenols further. METHODS The hydroxyapatites were coated by saliva to form S-HA, an in-vitro model of experimental pellicle. Streptococcus mutans 3a3 and Actinomyces viscosus ATCC 19246 were chosen as the main cariogenic bacterium, and the microorganisms were radiolabelled by growing them in TPY culture medium supplemented with 3H-thymidine. Tea polyphenols solution was prepared, the concentrations of which were 0.5, 1.0, 2.0 and 4.0 mg/ml respectively. Two parts of inhibited adherence tests were done with TP-treated S-HA or TP-treated bacterium. In the first one, S-HA was immerged into the TP solution of different concentrations for 1 h before the attachment of bacterium. In the other, the bacterium were mixed with the TP solution for 1 h and then centrifuged and washed before bound to S-HA. The whole process was carried on in KCl buffer solution. The number of 3H-thymidine-labelled bacterium which attached to S-HA were determined by scintillation counting. RESULTS In both the two parts of this study, tea polyphenols solution, the concentrations of which were changed from 1.0 to 4.0 mg/ml, could decrease the number of S. mutans 3a3 and A. viscosus ATCC 19246, and the inhibition rates rose with the increase of the concentrations of TP solution. But the inhibitory effects of 0.5 mg/ml TP solution were inconsistent in different tests. The results showed that 1.0-4.0 mg/ml TP solution could inhibit the attachments of S. mutans and A. viscosus to S-HA effectively. The inhibitory functions of tea polyphenols were so obvious that in some experiments, while the concentrations of TP solution were changed from 2.0 to 4.0 mg/ml, the number of 3H-thymidine-labelled bacterium which attached to S-HA was even less than that of the same bacterium which attached to naked HA. CONCLUSION Tea polyphenols can inhibit the preliminary adherence of Streptococcus mutans and Actinomyces viscosus to S-HA effectively. TP may prevent enamel from caries by decreasing the adherence of main cariogenic bacterium to salivary acquired pellicle.
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Zhan L, Yortsos YC. Identification of the permeability field of a porous medium from the injection of a passive tracer. PHYSICAL REVIEW. E, STATISTICAL PHYSICS, PLASMAS, FLUIDS, AND RELATED INTERDISCIPLINARY TOPICS 2000; 62:863-879. [PMID: 11088544 DOI: 10.1103/physreve.62.863] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/1999] [Revised: 02/28/2000] [Indexed: 05/23/2023]
Abstract
We propose a method for the direct inversion of the permeability field of a porous medium from the analysis of the displacement of a passive tracer. By monitoring the displacement front at successive time intervals (for example, using a tomographic method), the permeability can be directly obtained from the solution of a nonlinear boundary-value problem. Well posedness requires knowledge of the pressure profile or the permeability at no-flow boundaries. The method is tested using synthetic data in two dimensions (2D) (and some 3D) geometries for a variety of heterogeneous fields and found to work well when the permeability contrast is not too large. However, it is sensitive to sharp variations in permeability. In the latter case, a modified approach based on the successive injection in both directions and the use of an optimization technique leads to improved estimates. The sensitivity to measurement errors is analyzed. An important feature of the direct method is that it also applies to anisotropic porous media. When the principal axes of anisotropy are known, a suitable procedure is proposed and demonstrated using synthetic data.
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Zhan L. Cognitive adaptation and self-consistency in hearing-impaired older persons: testing Roy's adaptation model. Nurs Sci Q 2000; 13:158-65. [PMID: 11847701 DOI: 10.1177/08943180022107447] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
This study, based on constructs from Roy's adaptation model, examined the relationship between cognitive adaptation processes and self-consistency in hearing-impaired elders (N = 130). Data were collected through survey questionnaires. Major research hypotheses were formulated and tested. Results of this study supported Roy's theoretical proposition of cognitive adaptation processes and their role in the maintenance of self-consistency. Three cognitive processes (clear focus and methods, knowing awareness, and self-perception) significantly contributed to the maintenance of self-consistency. Understanding these cognitive processes helps nurses to promote effective adaptation in older persons.
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Reaven E, Zhan L, Nomoto A, Leers-Sucheta S, Azhar S. Expression and microvillar localization of scavenger receptor class B, type I (SR-BI) and selective cholesteryl ester uptake in Leydig cells from rat testis. J Lipid Res 2000; 41:343-56. [PMID: 10706582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023] Open
Abstract
This study investigates the relationship between the high density lipoprotein (HDL) receptor (scavenger receptors, SR-BI and SR-BII), selective lipoprotein-cholesteryl ester uptake, and testosterone production in Leydig cells of control, hypocholesterolemic and gonadotrophic hormone (hCG) treated rats. Leydig cells from mature control rats show poor efficiency in incorporation of labeled HDL-cholesteryl esters into testosterone, poor selective uptake of lipoprotein lipids overall, and a dramatic reduction of circulating levels of lipoproteins has no apparent effect on testosterone production or expression of intracellular enzymes synthesizing cholesterol. Leydig cells from control rats show minimal levels of SR-BI and SR-BII. However, similarly aged rats treated with hCG for several days undergo changes consistent with hormone-desensitization. Despite the resulting low levels of testosterone production, SR-BI levels are dramatically increased, Leydig cells now efficiently internalize HDL-supplied cholesteryl esters by the selective cholesterol uptake process, and various other cholesterol-sensitive genes of the cells are up-regulated. Only SR-BII expression remains negligible and unchanged throughout this period. It is of interest that Leydig cell SR-BI of hCG-treated rats is localized in surface microvilli, but is present also in an elaborate and complex channel system within the cytoplasm of the cells. In summary, Leydig cells differ from other rat steroidogenic cells in not depending on exogenous lipoprotein-cholesterol during periods of normal steroid hormone production. However, trophic hormone desensitization is accompanied by increased Leydig cell SR-BI expression and increased selective HDL-cholesteryl ester uptake, presumably in preparation for renewed testosterone production.
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