151
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Alpichshev Z, Analytis JG, Chu JH, Fisher IR, Chen YL, Shen ZX, Fang A, Kapitulnik A. STM imaging of electronic waves on the surface of Bi2Te3: topologically protected surface states and hexagonal warping effects. Phys Rev Lett 2010; 104:016401. [PMID: 20366373 DOI: 10.1103/physrevlett.104.016401] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Indexed: 05/07/2023]
Abstract
Scanning tunneling spectroscopy studies on high-quality Bi2Te3 crystals exhibit perfect correspondence to angle-resolved photoemission spectroscopy data, hence enabling identification of different regimes measured in the local density of states (LDOS). Oscillations of LDOS near a step are analyzed. Within the main part of the surface band oscillations are strongly damped, supporting the hypothesis of topological protection. At higher energies, as the surface band becomes concave, oscillations appear, dispersing with a wave vector that may result from a hexagonal warping term.
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Affiliation(s)
- Zhanybek Alpichshev
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, California 94025, USA
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152
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Chen YL, Chen WW, Du CE, Chang WK, Wang JL, Chung TY, Chen YH. Narrow-line, cw orange light generation in a diode-pumped Nd:YVO4 laser using volume Bragg gratings. Opt Express 2009; 17:22578-22585. [PMID: 20052183 DOI: 10.1364/oe.17.022578] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
We report on the demonstration of a narrow-line, cw orange 593-nm laser achieved via intracavity sum-frequency generation (SFG) of a diode-pumped dual-wavelength (1064 and 1342 nm) Nd:YVO(4) laser using two volume Bragg grating (VBG) reflectors. At diode pump power of up to 3.6 W, the 593-nm intracavity SFG laser radiates at the single longitudinal mode of spectral linewidth as narrow as approximately 15 MHz. More than 23-mW single-longitudinal-mode or 40-mW, <8.5-GHz (10-pm) linewidth (at 4.2-W diode pump power) 593-nm orange lights can be obtained from this compact laser system. Spectral tuning of the orange light was performed via the temperature tuning of the two VBGs in this system, achieving an effective tuning rate of ~5 pm/degrees C.
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Affiliation(s)
- Y L Chen
- Department of Optics and Photonics, National Central University, Jhongli 320, Taiwan
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153
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Chen WL, Chen SC, Chen CC, Chou CH, Shih YY, Chen YL, Kuo TS. Patient-driven loop control for ambulation function restoration in a non-invasive functional electrical stimulation system. Disabil Rehabil 2009; 32:65-71. [PMID: 19925278 DOI: 10.3109/09638280903026564] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE In this study, a patient-driven loop control in a non-invasive functional electrical stimulation (FES) system was designed to restore ambulation function of patients with stroke with their residual capabilities. METHOD With this patient-driven loop control, patients use the electromyographic (EMG) signals from their voluntary controlled muscles in affected extremity to adjust stimulus parameters of the system. A special designed FES system generated electrical stimuli to excite the paralysed muscles through surface electrodes on the basis of the control command from the residual myoelectric signals. The EMG signals were also served as the trigger and the adjustment of stimulus parameters and thereby adding versatility of the FES system. One patient with hemiplegia was recruited to conduct clinical evaluation and treated by using the new closed-loop FES system. RESULTS The experimental results showed that hemiplegic could successfully control the system to restore their lost ambulation functions with the strategy of patient-driven loop control. It is revealed that the mean velocity, cadence, stride length, active ankle motion range and functional ambulation category have improved significantly from 0.22 + or - 0.17 m/s, 37.3 + or - 15.5 steps/min, 0.32 + or - 0.11 m, 10 degrees , level 2 to 0.46 + or - 0.23 m/s, 58.2 + or - 19.1 steps/min, 0.73 + or - 0.22 m, 35 degrees , level 4 respectively for the patient. A paired t-test indicated that differences in the EMG of the tibialis anterior and the gastrocnemius muscles between patient's disabled (affected-side) foot and normal (unaffected-side) foot are not significant (p > 0.05) after 12 weeks of training. CONCLUSIONS According to the experiment results, this patient-driven loop control can be beneficial for patient with hemiplegia to restore their ambulation functions such as dorsi-flexion and plantar-flexion. The control strategy of this study has the potential to be employed not only in the FES system but also in other assistive devices.
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Affiliation(s)
- W L Chen
- Department of Electrical Engineering, Chang Gung University, Tao-Yuan, Taiwan.
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154
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Ramakrishnan S, Shah SA, Ruggeri L, Chen YL, Schweizer KS, Zukoski CF. Collective diffusion in colloid-polymer suspensions: relative role of thermodynamics and hydrodynamics. Langmuir 2009; 25:10507-10514. [PMID: 19583187 DOI: 10.1021/la901210c] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Theories such as the mode coupling theory (MCT) have seen recent success in predicting the kinetic arrest boundaries and resultant flow properties of colloidal suspensions. A key assumption of such theories is that interparticle forces and equilibrium structure control slow dynamics and gelation, not long-time many-body hydrodynamics. Here we report measurements of short-time collective diffusivities of colloid-polymer suspensions aimed at elucidating the relative contributions of hydrodynamics and thermodynamics as a phase transition or gelation boundary is approached. The experimental system is a hard sphere octadecyl silica suspension to which nonadsorbing polystyrene is added. Two different polymer molecular weights are chosen such that they give rise to a liquid-liquid or a gel transition as the colloid volume fraction or polymer concentration is increased. The short-time diffusivities are measured for each polymer molecular weight as a function of polymer concentration and colloid volume fraction. At a fixed polymer molecular weight and concentration, the colloid volume fraction is varied from dilute to concentrated and near the phase separation boundary. It is found for all measured colloid volume fractions that the diffusivities decrease linearly with increasing strength of the polymer-mediated depletion attraction at a fixed polymer molecular weight. Comparisons are made with theoretical predictions in the dilute limit. When the effects of thermodynamics are normalized out by multiplying the measured diffusivities with the suspension structure factor, it is found that the hydrodynamic effects are essentially those of hard spheres independent of the range and strength of depletion attraction.
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Affiliation(s)
- S Ramakrishnan
- Department of Chemical and Biomedical Engineering, FAMU-FSU College of Engineering, Tallahassee, Florida 32312, USA.
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155
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Chen YL, Chen CL, Lin HY, Chen CW, Chen YF, Hung Y, Mou CY. Enhancement of random lasing based on the composite consisting of nanospheres embedded in nanorods template. Opt Express 2009; 17:12706-12713. [PMID: 19654676 DOI: 10.1364/oe.17.012706] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A simple and general approach has been developed for the enhancement of random lasing based on the composite consisting of nanospheres and nanorods array. Due to the inherent nature of high refractive index, the selected nanorods act efficiently as scattering feedback centers, which can promote the formation of closed loop paths of the emission arising from nanospheres. To illustrate our working principle, the composite consisting of Tb(OH)(3)/SiO(2) nanospheres and ZnO nanorods was chosen as an example. Quite interestingly, it is found that the random lasing behavior can be easily achieved for the composite system, while it is absent in pure Tb(OH)(3)/SiO(2) nanospheres. The strategy demonstrated here should be very useful for the future development of coherent light emission sources and many other optoelectronic devices.
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Affiliation(s)
- Y L Chen
- Department of Physics, National Taiwan University, Taipei 106, Taiwan.
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156
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Chen YL, Analytis JG, Chu JH, Liu ZK, Mo SK, Qi XL, Zhang HJ, Lu DH, Dai X, Fang Z, Zhang SC, Fisher IR, Hussain Z, Shen ZX. Experimental realization of a three-dimensional topological insulator, Bi2Te3. Science 2009; 325:178-81. [PMID: 19520912 DOI: 10.1126/science.1173034] [Citation(s) in RCA: 917] [Impact Index Per Article: 61.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Three-dimensional topological insulators are a new state of quantum matter with a bulk gap and odd number of relativistic Dirac fermions on the surface. By investigating the surface state of Bi2Te3 with angle-resolved photoemission spectroscopy, we demonstrate that the surface state consists of a single nondegenerate Dirac cone. Furthermore, with appropriate hole doping, the Fermi level can be tuned to intersect only the surface states, indicating a full energy gap for the bulk states. Our results establish that Bi2Te3 is a simple model system for the three-dimensional topological insulator with a single Dirac cone on the surface. The large bulk gap of Bi2Te3 also points to promising potential for high-temperature spintronics applications.
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Affiliation(s)
- Y L Chen
- Stanford Institute for Materials and Energy Sciences, SLAC National Accelerator Laboratory, 2575 Sand Hill Road, Menlo Park, CA 94025, USA
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157
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Liang YQ, Chen BA, Chen YL. [Research progress on aurora kinase inhibitor MK-0457 in therapy for some hematological malignancies -- review]. Zhongguo Shi Yan Xue Ye Xue Za Zhi 2009; 17:810-815. [PMID: 19549414] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Recent work indicates that an Aurora kinase inhibitor MK-0457 (VX-680), a small-molecule inhibitor of Aurora kinases A, B, C and BCR-ABL, FLT-3, JAK-2, can block the progression of cell growth cycle, causing apoptosis in a range of human tumors. MK-0457 has the activity against expressions of wild-type and mutated bcr-abl gene, including the T315I mutant, and can inhibit the activity of FLT-3, JAK-2 and their mutated types as well. Clinical applications suggest that the MK-0457 has therapeutic effect on the highly refractory CML and CML with poor prognosis, Ph(+) ALL with T315I mutant, relapse refractory AML and JAK-2 positive myeloproliferative diseases (MPD). The intensive preclinical studies and the on-going phase II clinical trials will open up a new vista of therapy for some hematological malignancies. This review focuses on the pharmacologic action of MK-0457 and its clinical trial as well as combined application.
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Affiliation(s)
- Yi-Qiong Liang
- Department of Hematology, Zhongda Hospital, Southeast University Clinical Medical College, Nanjing, Jiangsu Province, China
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158
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Ko LS, Shum JT, Chen YL, Wang YS. Pesticides and myopia, a working hypothesis. Acta Ophthalmol 2009; 185:145-6. [PMID: 2853524 DOI: 10.1111/j.1755-3768.1988.tb02693.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- L S Ko
- Department of Ophthalmology, National Taiwan University Hospital, Taipei
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159
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Chen YL. Effects of penetrating acupuncture on peripheral nerve conduction velo-city in patients with diabetic peripheral neuropathy: a randomized controlled trial. ACTA ACUST UNITED AC 2009; 7:273-5. [DOI: 10.3736/jcim20090314] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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160
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Lin YJ, Deng MC, Wu SH, Chen YL, Cheng HC, Chang CY, Lee MS, Chien MS, Huang CC. Baculovirus-derived hemagglutinin vaccine protects chickens from lethal homologous virus H5N1 challenge. J Vet Med Sci 2008; 70:1147-52. [PMID: 19057130 DOI: 10.1292/jvms.70.1147] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Since outbreaks of highly pathogenic avian influenza (HPAI) in both human and poultry from 2003, it is critical to have effective vaccines. A cDNA fragment coding the entire hemagglutinin (HA) gene derived from an H5N1 strain (A/duck/China/E319-2/03) was cloned and expressed using the baculovirus system. Two weeks after receiving two doses of recombinant HA (rHA) vaccines, chickens develop high antibody response for hemagglutination inhibition (HI) at titer 7.2 log(2). Challenge studies revealed that vaccinated chickens with HI titers greater than 3 log(2) could have immunoprotection against the same HPAI H5N1 strain virus challenge through intranasal route. Additionally, HI titer of 5 log(2) determined whether the live viruses could not be detected from oropharyngeal, cloacal discharge or in tissues. This result suggests that the rHA expressed from baculovirus system could be a candidate for the development of a safe and efficient subunit vaccine for HPAI (H5N1).
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Affiliation(s)
- Y J Lin
- Animal Health Research Institute, Council of Agriculture, Taipei, Taiwan
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161
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Yang EC, Chuang YC, Chen YL, Chang LH. Abnormal foraging behavior induced by sublethal dosage of imidacloprid in the honey bee (Hymenoptera: Apidae). J Econ Entomol 2008; 101:1743-8. [PMID: 19133451 DOI: 10.1603/0022-0493-101.6.1743] [Citation(s) in RCA: 176] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Although sublethal dosages of insecticide to nontarget insects have never been an important issue, they are attracting more and more attention lately. It has been demonstrated that low dosages of the neonicotinoid insecticide imidacloprid may affect honey bee, Apis mellifera L., behavior. In this article, the foraging behavior of the honey bee workers was investigated to show the effects of imidacloprid. By measuring the time interval between two visits at the same feeding site, we found that the normal foraging interval of honey bee workers was within 300 s. However, these honey bee workers delayed their return visit for > 300 s when they were treated orally with sugar water containing imidacloprid. This time delay in their return visit is concentration-dependent, and the lowest effective concentration was found to be 50 microg/liter. When bees were treated with an imidacloprid concentration higher than 1,200 microg/liter, they showed abnormalities in revisiting the feeding site. Some of them went missing, and some were present again at the feeding site the next day. Returning bees also showed delay in their return trips. Our results demonstrated that sublethal dosages of imidacloprid were able to affect foraging behavior of honey bees.
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Affiliation(s)
- E C Yang
- Department of Entomology, National Chung Hsing University, Taichung, Taiwan.
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162
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Abstract
Carbon nanotubes (CNTs) used to reinforce polymer matrix composites are functionalized to form covalent bonds with the polymer in order to enhance the CNT/polymer interfaces. These bonds destroy the perfect atomic structures of a CNT and degrade its mechanical properties. We use atomistic simulations to study the effect of hydrogenization on the mechanical properties of single-wall carbon nanotubes. The elastic modulus of CNTs gradually decreases with the increasing functionalization (percentage of C-H bonds). However, both the strength and ductility drop sharply at a small percentage of functionalization, reflecting their sensitivity to C-H bonds. The cluster C-H bonds forming two rings leads to a significant reduction in the strength and ductility. The effect of carbonization has essentially the same effect as hydrogenization.
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Affiliation(s)
- Z Q Zhang
- FML, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, People's Republic of China
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163
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164
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Kao CM, Chen CY, Chen SC, Chien HY, Chen YL. Application of in situ biosparging to remediate a petroleum-hydrocarbon spill site: field and microbial evaluation. Chemosphere 2008; 70:1492-1499. [PMID: 17950413 DOI: 10.1016/j.chemosphere.2007.08.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Revised: 08/12/2007] [Accepted: 08/14/2007] [Indexed: 05/25/2023]
Abstract
In this study, a full-scale biosparging investigation was conducted at a petroleum-hydrocarbon spill site. Field results reveal that natural attenuation was the main cause of the decrease in major contaminants [benzene, toluene, ethylbenzene, and xylenes (BTEX)] concentrations in groundwater before the operation of biosparging system. Evidence of the occurrence of natural attenuation within the BTEX plume includes: (1) decrease of DO, nitrate, sulfate, and redox potential, (2) production of dissolved ferrous iron, sulfide, methane, and CO(2), (3) decreased BTEX concentrations along the transport path, (4) increased microbial populations, and (5) limited spreading of the BTEX plume. Field results also reveal that the operation of biosparging caused the shifting of anaerobic conditions inside the plume to aerobic conditions. This variation can be confirmed by the following field observations inside the plume due to the biosparging process: (1) increase in DO, redox potential, nitrate, and sulfate, (2) decrease dissolved ferrous iron, sulfide, and methane, (3) increased total cultivable heterotrophs, and (4) decreased total cultivable anaerobes as well as methanogens. Results of polymerase chain reaction, denaturing gradient gel electrophoresis, and nucleotide sequence analysis reveal that three BTEX biodegraders (Candidauts magnetobacterium, Flavobacteriales bacterium, and Bacteroidetes bacterium) might exist at this site. Results show that more than 70% of BTEX has been removed through the biosparging system within a 10-month remedial period at an averaged groundwater temperature of 18 degrees C. This indicates that biosparging is a promising technology to remediate BTEX contaminated groundwater.
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
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165
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Hsieh SH, Ying NW, Wu MH, Chiang WF, Hsu CL, Wong TY, Jin YT, Hong TM, Chen YL. Galectin-1, a novel ligand of neuropilin-1, activates VEGFR-2 signaling and modulates the migration of vascular endothelial cells. Oncogene 2008; 27:3746-53. [PMID: 18223683 DOI: 10.1038/sj.onc.1211029] [Citation(s) in RCA: 165] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Galectin-1 (Gal-1), a homodimeric prototype of the galectins with a single carbohydrate-recognition domain, was recently identified as being overexpressed in tumor-associated capillary endothelial cells. The role of Gal-1 in endothelial cellular functions and the mechanism of action of Gal-1 remain unknown. Neuropilin-1 (NRP1) is a neuronal receptor that mediates repulsive growth cone guidance, and NRP1 functions in endothelial cells as a coreceptor (with vascular endothelial growth factor receptors (VEGFRs)) for VEGF(165). In this study, we found that Gal-1 was overexpressed in the tumor-associated endothelial cells of oral squamous cell carcinomas (P<0.001). Gal-1 increased the proliferation and adhesion of endothelial cells, and enhanced cell migration in combination with VEGF(165). Surprisingly, Gal-1 selectively bound NRP1 via the carbohydrate-recognition domain, but did not bind VEGFR-1, VEGFR-2 or VEGFR-3. The Gal-1-NRP1 interaction mediated the migration and adhesion of endothelial cells. The binding of Gal-1 to NRP1 enhanced VEGFR-2 phosphorylation and stimulated the activation of the mitogen activated protein (MAP) kinases SAPK1/JNK (stress activated protein kinase-1/c-Jun NH2-terminal kinase). These findings show, for the first time, that Gal-1 can directly bind to NRP1 on endothelial cells, and can promote the NRP1/VEGFR-2-mediated signaling pathway as well as NRP1-mediated biological activities.
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Affiliation(s)
- S H Hsieh
- Institute of Oral Medicine, National Cheng Kung University, College of Medicine, Tainan, Taiwan
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166
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Chen CC, Wai YY, Chen YL. SU-FF-I-88: Using Fast MR Imaging Techniques to Evaluate T1 Changes After Hyperoxygenation of Brain Tumor preliminary Result. Med Phys 2007. [DOI: 10.1118/1.2760465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022] Open
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167
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Abstract
Two new guaianolides, namely, 3beta,8alpha-dihydroxy-13-methoxyl-4(14),10(15)-dien-(1alphaH,5alphaH,6beta H,11betaH)-12,6-olide (1) and 3beta,8alpha-dihydroxy-13-methoxyl-4(14),10(15)-dien-(1alphaH,5alphaH,6beta H,11alphaH)-12,6-olide (2), together with six known guaianolides, 8-hydroxyzaluzanin C, austricin, chlorojanerin, cynaropicrin, chlorohyssopifolin E and chlorohyssopifolin A were isolated from the aerial parts of Saussurea alata. The structures were established mainly based on spectral analysis, especially 2D NMR techniques.
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Affiliation(s)
- G Ren
- Research Centre of Siyuan Natural Pharmacy and Bio-toxicity, College of Life Sciences, Zhejiang University, Hangzhou 310058, China
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168
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Lee A, Chen YL, Lee MH, Wong WY. Oxadisilole-Fused Isoindole. Synlett 2006. [DOI: 10.1055/s-2006-950420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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169
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Lin YJ, Chen YL, Huang CY, Wu MF. Photocatalysis of 2,2',3,4,4',5'-hexachlorobiphenyl and its intermediates using various catalytical preparing methods. J Hazard Mater 2006; 136:902-10. [PMID: 16494999 DOI: 10.1016/j.jhazmat.2006.01.031] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/09/2005] [Revised: 11/18/2005] [Accepted: 01/16/2006] [Indexed: 05/06/2023]
Abstract
Four etching solutions used on support materials and two coating methods of TiO(2) were conducted to investigate the effects of catalytical preparing methods on the photocatalysis of 2,2',3,4,4',5'-hexachlorobiphenyl (PCB congener 138). The results of XRD analyses confirmed that various etching solutions used on support substrates did not influence the characteristics of titanium(IV) oxide. The XRD patterns of crystallization for the catalysts before and after purification remained unchanged. Hydrofluoric acid used as an etching solution for the support substrates provided the best adhesion stability for the catalysts that demonstrated the highest photocatalytic efficiency for congener 138. Xenon and ultraviolet lamps were used to compare the irradiation effect on photocatalysis. The shortest half-lives of congener 138 were 7.4 and 12.2 h using xenon and UV reactors, respectively. Lower chlorinated biphenyls (lower congener numbers) were identified through the continuous dechlorination of congener 138. PCB congeners 99, 87, 66, 49, 28, 17, 9, and 7 were detected as a result of dechlorination from higher chlorinated congeners to lower chlorinated congeners along with the extension of exposure times. The concentrations of chloride ion were increased with increasing exposure time through dechlorination, while the concentrations of organic chlorine of congener 138 were decreased. Meta-dechlorination was the most commonly found mechanism for the photocatalysis of PCB 138. The activation energy of the photocatalysis of congener 138 was 70.8 kJ mol(-1).
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Affiliation(s)
- Y J Lin
- Department of Environmental Science and Engineering, National Pingtung University of Science and Technology, Pingtung 912, Taiwan.
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170
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Chen YL, Hau CK, Wang H, He H, Wong MS, Lee AWM. Oxadisilole-Fused Isobenzofurans. Synthesis and Characterization of Oxadisilole-Substituted Acenes. J Org Chem 2006; 71:3512-7. [PMID: 16626133 DOI: 10.1021/jo060099d] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Mono- and bis-oxadisilole-fused isobenzofurans were first synthesized and isolated. A series of mono-, bis-, and tris-oxadisilole-substituted acenes were then synthesized by benzyne Diels-Alder reactions with the isobenzofurans. The photophysical, redox, and thermal properties of these new acenes were characterized.
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Affiliation(s)
- Ya-Li Chen
- Department of Chemistry and Centre for Advanced Luminescence Materials, Hong Kong Baptist University, Kowloon Tong, Hong Kong, China
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171
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Shi ZY, Chen YL, Feng G, Liu RJ, Christie P, Li XL. Arbuscular mycorrhizal fungi associated with the Meliaceae on Hainan island, China. Mycorrhiza 2006; 16:81-87. [PMID: 16133253 DOI: 10.1007/s00572-005-0017-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2004] [Accepted: 07/08/2005] [Indexed: 05/04/2023]
Abstract
Species richness, spore density, frequency of occurrence, and relative abundance of AM fungi were determined in rhizosphere soil samples from nine tropical rainforest sites on Hainan island, south China, and the arbuscular mycorrhizal (AM) status of members of the Meliaceae was examined. All 28 plant taxa investigated (25 species including two varieties of 1 species and three varieties of another) were colonized by AM fungi. The mean proportion of root length colonized was 56% (range 10-95%). Vesicles were observed in 27 and hyphal coils in 26 of the 28 plant taxa. Mycorrhizas were of the Paris-type or intermediate-type, with no Arum-type mycorrhizas observed. Species richness of AM fungi varied from 3 to 15 and spore density from 46 to 1,499 per 100 g rhizosphere soil. Of 33 AM fungal taxa in five genera isolated and identified, 18 belonged to Glomus, 9 to Acaulospora, 1 to Entrophospora, 2 to Gigaspora, and 3 to Scutellospora. Acaulospora and Glomus were the dominant genera identified. Glomus claroideum was the taxon most commonly isolated, with a frequency of occurrence of 56.5% and relative abundance of 10.4%. A positive correlation was found between percentage of root length colonization and species richness. However, there was no correlation between spore density and percentage of root length colonized by AM fungi.
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Affiliation(s)
- Z Y Shi
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100094, China
| | - Y L Chen
- Research Institute of Tropical Forestry, Chinese Academy of Forestry, Guangzhou, Guangdong, 510520, China
- School of Biological Sciences and Biotechnology, Murdoch University, Perth, WA, 6150, Australia
| | - G Feng
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100094, China
| | - R J Liu
- Mycorrhiza Laboratory, Laiyang Agricultural College, Laiyang, Shandong, 265200, China
| | - P Christie
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100094, China
- Agricultural and Environmental Science Department, Queen's University Belfast, Newforge Lane, Belfast, BT9 PX, UK
| | - X L Li
- College of Resources and Environmental Sciences, China Agricultural University, Beijing, 100094, China.
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172
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Huang MH, Liu RH, Chen YL, Rhodes SL. Correlation of Drug-Testing Results - Immunoassay versus Gas Chromatography-Mass Spectrometry. Forensic Sci Rev 2006; 18:9-41. [PMID: 26247108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
The need for and prevalence of workplace drug-testing programs mandate the development of an effective and efficient two-step test strategy. Successful implementation of the two-step test strategy relies on the establishment of a reasonable correlation between the preliminary and the confirmatory test data and the selection of an appropriate cutoff for each test step. Correlations of test data derived form these two test steps were most commonly studied qualitatively by comparing the positive/negative test result concluded by these two test steps; however, when instrument-based immunoassays (IA) are used in the preliminary test step, the resulting "semiquantitative" and "apparent" concentration of the targeted analyte can be quantitatively correlated to the analyte concentration as determined by gas chromatography-mass spectrometry (GC-MS). Specimens selected for quantitative correlation studies should be clinical specimens with the distributions of metabolites similar to that present in test specimens; if the resulting correlation data are to be used for selecting appropriate/corresponding cutoffs for these two test steps, the concentrations of the targeted analyte in these specimens should also be within a narrow range centering on the proposed GC-MS cutoff concentration. Among the very significant number of reports correlating IA and GC-MS test data, cannabis and urine are the most common drug category and test specimen studied. The degree of correlation between IA and the GC-MS test data varies with the IA reagent manufacturers, and even with manufacture dates/lots of those supplied by the same manufacturer. The most important factors underlying the observed degree of correlation are undoubtedly the cross-reacting characteristics of the antibody and the metabolite distribution pattern of the drug of concern. Over time, specificities of IA reagents have been optimized so that the two-step test strategy can be most effectively and efficiently applied using the cutoffs mandated by workplace drug-testing programs. The nature of correlation and the selection of appropriate/corresponding cutoffs between IA and GC-MS test data derived from alternate biological matrices are yet to be fully understood and established.
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Affiliation(s)
- M H Huang
- Department of Medical technology, Fooyin University, Ta-Liao Hsiang, Kaohsiung Hsien, Taiwan
| | - R H Liu
- Department of Medical technology, Fooyin University, Ta-Liao Hsiang, Kaohsiung Hsien, Taiwan
| | - Y L Chen
- Department of Biotechnology, National Kaohsiung Normal University, Yen-Chao Hsiang, Kaohsiung Hsien, Taiwan
| | - S L Rhodes
- Graduate Program in Forensic Science, University of Alabama at Birmingham, Birmingham, AL, USA
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173
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Kao CM, Liu JK, Chen YL, Chai CT, Chen SC. Factors affecting the biodegradation of PCP by Pseudomonas mendocina NSYSU. J Hazard Mater 2005; 124:68-73. [PMID: 15979238 DOI: 10.1016/j.jhazmat.2005.03.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/18/2004] [Revised: 02/22/2005] [Accepted: 03/26/2005] [Indexed: 05/03/2023]
Abstract
A pentachlorophenol (PCP) degrading bacterium was isolated from PCP-contaminated soils and identified as Pseudomonas mendocina NSYSU (P. mendocina NSYSU). The main objectives of this study were to (1) clarify the factors affecting the ability and efficiency of PCP biodegradation by P. mendocina NSYSU, and (2) optimize the use of this bacterium in bioremediation of PCP. Microcosm experiments were conducted to fulfill the objectives. In batch cultures, P. mendocina NSYSU used PCP as its sole source of carbon and energy and was capable of completely degrading this compound. This was confirmed by the stoichiometric release of chloride ion. Moreover, P. mendocina NSYSU was able to mineralize a high concentration of PCP (150 mg/L). Results from the oxygen concentration experiment reveal that the growth of P. mendocina NSYSU was inhibited under low oxygen and anaerobic conditions. Results indicate that the optimal growth conditions for P. mendocina NSYSU include the following: slightly acidic (6<pH<7), aerobic, and relatively moderate ambient temperature (20 degrees C<temperature<30 degrees C) conditions. Addition of extra carbon sources (sodium acetate and glucose) could not enhance the PCP biodegradation. No PCP byproducts were detected after eight days of incubation in this study. This suggests that P. mendocina NSYSU is able to effectively biodegrade PCP and its biodegradation byproducts without the accumulation of inhibitory toxic compounds. Results from this study could be used to assist the optimization of its use in bioremediation of PCP.
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
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174
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Rao GN, Yao YD, Chen YL, Wu KT, Chen JW. Particle size and magnetic field-induced optical properties of magnetic fluid nanoparticles. Phys Rev E Stat Nonlin Soft Matter Phys 2005; 72:031408. [PMID: 16241436 DOI: 10.1103/physreve.72.031408] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2005] [Revised: 06/15/2005] [Indexed: 05/05/2023]
Abstract
Magnetite nanoparticles with diameters of 7, 9, and 12 nm have been prepared by a chemical coprecipitation method. The transmission of light through magnetic fluid containing these nanoparticles has been investigated as a function of film thickness with wavelength between 400 and 750 nm, and applied magnetic fields up to 275 Oe. The transmission threshold shifts to the lower wavelength side with decreasing magnetic fluid film thickness as well as the particle size. For a given film thickness, the transmittance increases with increasing magnetic field for films with a particle size of 7 and 9 nm, but decreases in the 12-nm film. This is attributed to the competition between the van der Waals and dipole-dipole interaction.
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Affiliation(s)
- G Narsinga Rao
- Institute of Physics, Academia Sinica, Taipei, Taiwan, Republic of China
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175
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Abstract
AIMS The ability of Azotobacter vinelandii, a N(2)-fixing bacterium, to biodegrade tetracyanonickelate (TCN) was evaluated. METHODS AND RESULTS The amounts of TCN were measured spectrophotometrically. Ammonia was determined colorimetrically by the indophenol method. The produced methane from TCN conversion by A. vinelandii was detected by gas chromatography. Results showed that A. vinelandii was able to biodegrade 1 mmol l(-1) of TCN. Ammonia and methane were detected during the process of TCN degradation. Effects of exogenous nitrogen sources on TCN degradation were addressed in this study. Results revealed that the addition of ammonia (1, 5 and 10 mmol l(-1)) into the reaction mixtures caused decrease of TCN degradation rate during a 24-h incubation period. This inhibition was also observed when nitrite (5 and 10 mmol l(-1)) was added, whereas TCN degradation still proceeded after the addition of nitrate at the same concentrations. Furthermore, the rate of TCN utilization was strikingly enhanced when 0.8% of glucose was added. CONCLUSIONS Azotobacter vinelandii can degrade 1 mmol l(-1) of TCN into ammonia and methane. However, the inhibitory effects of exogenous ammonia and nitrite on TCN degradation by this bacterium were found in this study. SIGNIFICANCE AND IMPACT OF THE STUDY This is the first report defining the capability of A. vinelandii to degrade TCN. This bacterium might have potential value in applied strategies for removing metal-cyano wastes. Furthermore, these findings would be helpful in designing a practical system inoculated with A. vinelandii for the treatment of TCN.
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
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176
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Abstract
Cortical dysplasia is a neuronal migration disorder occasionally associated with anomalous draining veins. However, to our knowledge, no intracranial haemorrhage in conjunction with this association has been reported in the literature. We herein report a 7-month-old baby girl with cortical dysplasia associated with an ipsilateral cortical draining vein and complicated with subdural haemorrhage, with the diagnosis made by computed tomography and magnetic resonance imaging. This case demonstrated that patients with this condition could have an excellent prognosis even when the anomalous veins coexist with intracranial haemorrhage. We postulate that venous rupture may be the cause of this condition and further discuss the possible pathophysiology.
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Affiliation(s)
- A M C Wong
- Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Linkou Medical Center, Tao Yuan, Taiwan, ROC
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177
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Chen KF, Kao CM, Hsieh CY, Chen SC, Chen YL. Natural biodegradation of MTBE under different environmental conditions: microcosm and microbial identification studies. Bull Environ Contam Toxicol 2005; 74:356-364. [PMID: 15841978 DOI: 10.1007/s00128-004-0592-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Affiliation(s)
- K F Chen
- National Sun Yat-Sen University, Institute of Environmental Engineering, Kaohsiung, Taiwan
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178
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179
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Abstract
Linear and angular benzobisoxadisiloles 14 and 16 can serve as the precursors for stepwise generations of the syntetic equivalents of 1,4- and 1,3-benzdiynes. Benzynes generated were trapped as [4+2] cycloaddition products. Two identical or different rings can be fused to the benzdiyne equivalents. Highly substituted arenes were obtained by removing the oxygen bridges from the furan adducts. The synthesis of naphthoxadisilole 28, which can serve as the precursor of 2,3-naphthyne, is also described.
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Affiliation(s)
- Ya-Li Chen
- Department of Chemistry, Centre for Advanced Luminescence Materials and Central Laboratory of the Institute of Molecular Technology for Drug Discovery and Synthesis, Hong Kong Baptist University, Kowlooon Tong, Hong Kong, China
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180
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan, Republic of China
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181
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Abstract
Burkholderia pseudomallei Ara- in rice fields was detected using PCR-based techniques with 16S RNA and flagella gene primer sets. The sensitivity of these PCRs was at least 1 CFU/mL of B. pseudomallei Ara- preincubated into Ashdown's medium for 6 h. B. pseudomallei Ara- DNA from watery soil were more detectable than from dry soil. The distribution of this DNA was mainly found at a depth of 300-600 mm under crop-covered fields, but not detected in the location of soil close to the land surface. The results suggest that PCR based on 16S RNA and flagella gene primer sets can be applied to investigate the presence of B. pseudomallei Ara- in contaminated soil of rice fields.
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
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182
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Abstract
The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to evaluate the (1) feasibility of enhancing PCE biodegradation using cane molasses and sludge cakes as the primary substrates under methanogenic and iron reducing conditions, and (2) potential of installation a sludge cake/cane molasses biobarrier to clean up PCE-contaminated aquifers. The biodegradability of sludge cake (from secondary wastewater treatment system) and cane molasses was tested using bioavailability experiments. Results show that biodegradable materials were released from sludge cake/cane molasses and utilized by microbial consortia. Based on the chemical oxygen demand (COD) tests, approximately 28 and 248 mg of biodegradable COD can be released from 1g of sludge cake and 1g of cane molasses under anaerobic conditions, which have the potential to convert 70 and 620 mg of PCE to ethylene (ETH), respectively. Reductive dechlorination was evaluated using microcosms containing primary substrates (sludge cake/cane molasses) and inocula (aquifer sediments). Results indicate that sludge cake and cane molasses can serve as the diffusion sources of primary substrates, and enhance the reductive dechlorination of PCE under methanogenic processes. However, results from this study were not sufficient enough to show that reductive dechlorination of PCE would occur under iron-reducing conditions. This indicates that more studies need to be performed to further evaluate the role of iron reduction on the PCE dechlorination. Results reveal that it is feasible and applicable to install a sludge cake or cane molasses biobarrier to clean up PCE contaminated aquifers. From an engineering point of view, the sludge cake/cane molasses biobarrier has the potential to become an environmentally and economically acceptable technology for PCE bioremediation.
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan.
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183
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Ying BW, Tang JP, Gao YZ, Chen YL, Li YB, Wu J, Zhang J, Shi MS, Zhu QF, Zhou XK, Hou YP. Haplotype frequencies of three Y-chromosome STR loci in Tibetan ethnic group of Chinese population. J Forensic Sci 2003; 48:449-50. [PMID: 12665015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/01/2023]
Affiliation(s)
- B W Ying
- Institute of Forensic Medicine, Sichuan University, (West China University of Medical Sciences), Chengdu 610041, Sichuan, PR China
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184
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Abstract
Optimum conditions were determined for the growth of Burkholderia pseudomallei in natural soils or waters. It grows better in paddy soil, crop-covered and fallow field than in fresh and salty water. Although the optimal temperature and pH for the growth were 37 or 42 degrees C, and 6.5 or 7.5 in an environmental-mimicking soil medium, this bacterium can still grow at 4 degrees C, which was suggested to be related with the occurrence of melioidosis in some cold areas. In soil media with water content < 15. B. pseudomallei did not grow until 60 d of incubation, suggesting that water contents of soils in which it dwelled would be one important factor in determining the growth rate.
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Affiliation(s)
- Y S Chen
- Section of Infectious Disease, Veterans General Hospital, Kaohsiung, Taiwan
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185
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Hung-Lung C, Chen TC, Tsai MC, Chen YL. Adsorption characteristics of benzene on biosolid adsorbent. Water Sci Technol 2003; 47:83-87. [PMID: 12578178] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
This study selected biosolids from a petrochemical wastewater treatment plant as the raw material. The sludge was immersed in 0 to 5 mol l(-1) of ZnCl2 solutions and pyrolyzed at different temperatures. When the sludge was pyrolyzed for 30 min at temperatures of 400, 500, 600, and 700 degrees C, the corresponding surface area of the biosolid adsorbent was 46, 401, 921, and 727 m2/g, respectively. Pore size analysis indicated that the mesopore (20 to 500 A) contributed more than the macropore and micropore in the sludge pyrolytic residue. When the benzene influent concentration was 800 ppmv, the adsorption capacity ranged from 59 to 164 mg/g for different biosolid adsorbents. A larger BET surface area and smaller average pore diameter yielded a larger benzene adsorption capacity.
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Affiliation(s)
- C Hung-Lung
- Department of Environmental Engineering, Fooyin Institute of Technology, Kaoshsiung Hsien, 831, Chinese Taiwan
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186
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Kao CM, Chen SC, Wang JY, Chen YL, Lee SZ. Remediation of PCE-contaminated aquifer by an in situ two-layer biobarrier: laboratory batch and column studies. Water Res 2003; 37:27-38. [PMID: 12465785 DOI: 10.1016/s0043-1354(02)00254-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The industrial solvent tetrachloroethylene (PCE) is among the most ubiquitous chlorinated compounds found in groundwater contamination. The objective of this study was to develop an in situ two-layer biobarrier system consisting of an organic-releasing material layer followed by an oxygen-releasing material layer. The organic-releasing material, which contained sludge cakes from a domestic wastewater treatment plant, is able to release biodegradable organics continuously. The oxygen-releasing material, which contained calcium peroxide, is able to release oxygen continuously upon contact with water. The first organic-releasing material layer was to supply organics (primary substrates) to reductively dechlorinate PCE in situ. The second oxygen-releasing material layer was to release oxygen to aerobic biodegrade or cometabolize PCE degradation byproducts from the first anaerobic layer. Batch experiments were conducted to design and identify the components of the organic and oxygen-releasing materials, and evaluate the organic substrate (presented as chemical oxygen demand (COD) equivalent) and oxygen release rates from the organic-releasing material and oxygen-releasing materials, respectively. The observed oxygen and COD release rates were approximately 0.0368 and 0.0416 mg/d/g of material, respectively. A laboratory-scale column experiment was then conducted to evaluate the feasibility of this proposed system for the bioremediation of PCE-contaminated groundwater. This system was performed using a series of continuous-flow glass columns including a soil column, an organic-releasing material column, two consecutive soil columns, and an oxygen-releasing material column, followed by two other consecutive soil columns. Anaerobic acclimated sludges were inoculated in the first four columns, and aerobic acclimated sludges were inoculated in the last three columns to provide microbial consortia for contaminant biodegradation. Simulated PCE-contaminated groundwater with a flow rate of 0.25 L/d was pumped into this system. Effluent samples from each column were analyzed for PCE and its degradation byproducts. Results show that up to 99% of PCE removal efficiency was obtained in this passive system. Thus, the biobarrier treatment scheme has the potential to be developed into an environmentally and economically acceptable remediation technology for the in situ treatment of PCE-contaminated aquifer.
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Affiliation(s)
- C M Kao
- Institute of Environmental Engineering, National Sun Yat-Sen University, 804 Kaohsiung, Taiwan.
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187
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Hsu SW, Rodesch G, Luo CB, Chen YL, Alvarez H, Lasjaunias PL. Concomitant conus medullaris arteriovenous malformation and sacral dural arteriovenous fistula of the filum terminale. Interv Neuroradiol 2002; 8:47-53. [PMID: 20594512 PMCID: PMC3572522 DOI: 10.1177/159101990200800109] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2002] [Accepted: 02/05/2002] [Indexed: 11/17/2022] Open
Abstract
SUMMARY A patient with a spinal intradural arteriovenous malformation (AVM) at the conus medullaris concomitant with a sacral dural arteriovenous fistula (AVF) of the filum terminale is reported. A 44-year-old-male presentied with bilateral leg weakness and urinary incontinence for several months. Spinal angiography demonstrated two lesions: one was spinal intradural AVM at the conus medullaris supplied by the anterior spinal artery; the other was sacral dural AVF of the filum terminale supplied by the middle sacral artery. Although multifocal spinal cord AVMs have been reported, this is the first case report of two different types of vascular malformations coexisting in one patient. The arterial supply of the dural AVF of the filum by the middle sacral artery is also first demonstrated in the literature. The patient was treated successfully by surgical approach for both lesions in the same operation.
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Affiliation(s)
- S W Hsu
- Department of Diagnostic Radiology, Chang Gung Memorial Hospital, Kaohsiung, Taiwan
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188
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Chen YL, Luo CB, Hsu SW, Rodesch G, Lasjaunias P. Tuberous sclerosis complex with an unruptured intracranial aneurysm: manifestations of contiguous gene syndrome. Interv Neuroradiol 2002; 7:337-41. [PMID: 20663367 DOI: 10.1177/159101990100700410] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2001] [Accepted: 10/25/2001] [Indexed: 11/17/2022] Open
Abstract
SUMMARY With the advancement of molecular genetics, the deletion of the TSC2/PKD1 gene at chromosome 16p13.3 has been discovered to be responsible for the tuberous sclerosis complex sharing some of the clinical manifestations of autosomal dominant adult polycystic kidney disease such as multiple renal cysts and intracranial aneurysms. The unruptured aneurysm in tuberous sclerosis complex is far beyond the meaning it has in general population. The risk of aneurysmal hemorrhage in tuberous sclerosis complex may be higher than that in autosomal dominant adult polycystic kidney disease due to the synergistic effect of gene deletion and certainly much higher than that in the general population. For such high-risk patients with intracranial aneurysms doomed to subarachnoid hemorrh age, magnetic resonance angiography plays an important role in screening and follow-up, especially more critically for patients with contiguous gene syndrome. Endovascular coil embolization should be the first choice of treatment for un ruptured intracranial aneurysms.
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Affiliation(s)
- Y L Chen
- Department of Radiology, Chang Gung Memorial Hospital and University; Taoyuan and Kaohsiung; Taiwan
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189
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Li HY, Zhou SM, Li J, Chen YL, Wang SY, Shen ZC, Chen LY, Liu H, Zhang XX. Analysis of the drude model in metallic films. Appl Opt 2001; 40:6307-6311. [PMID: 18364937 DOI: 10.1364/ao.40.006307] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A method, believed to be new, to simulate Drude parameters for collective oscillation of the free carriers in metallic films is proposed. Plasma resonance frequency and relaxation were simulated simultaneously from both the real and the imaginary parts of the dielectric function of a metallic film after consideration of their correlation in the Drude model. As examples, the contributions of the electrons in Ag films and of the free carriers in metallic silicide, NbSi(2) and TaSi(2), films have been studied.
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190
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Abstract
The catalytic domain of a xylanase from the anaerobic fungus Neocallimastix patriciarum was made more alkalophilic through directed evolution using error-prone PCR. Transformants expressing the alkalophilic variant xylanases produced larger clear zones when overlaid with high pH, xylan-containing agar. Eight amino acid substitutions were identified in six selected mutant xylanases. Whereas the wild-type xylanase exhibited no activity at pH 8.5, the relative and specific activities of the six mutants were higher at pH 8.5 than at pH 6.0. Seven of the eight amino acid substitutions were assembled in one enzyme (xyn-CDBFV) by site-directed mutagenesis. Some or all of the seven mutations exerted positive and possibly synergistic effects on the alkalophilicity of the enzyme. The resulting composite mutant xylanase retained a greater proportion of its activity than did the wild type at pH above 7.0, maintaining 25% of its activity at pH 9.0, and its retention of activity at acid pH was no lower than that of the wild type. The composite xylanase (xyn-CDBFV) had a relatively high specific activity of 10128 micromol glucose x min(-1) x (mg protein)(-1) at pH 6.0. It was more thermostable at 60 degrees C and alkaline tolerant at pH 10.0 than the wild-type xylanase. These properties suggest that the composite mutant xylanase is a promising and suitable candidate for paper pulp bio-bleaching.
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Affiliation(s)
- Y L Chen
- Institute of BioAgricultural Sciences, Academia Sinica, Taipei, Taiwan, Republic of China
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191
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Abstract
For the first time, the influence of the injection solution composition on the quality of LC-MS-MS methods, in terms of column efficiency and peak shape, was systematically investigated. Various types of compounds, including polar ionic acidic, polar ionic basic and non-polar neutral compounds, were prepared in different solutions ranging from 100% water to 100% acetonitrile. Different volumes of these solutions were injected onto either C18 or silica columns connected to tandem mass spectrometry. The mobile phases consisted of acetonitrile, water, and small amounts of volatile acid or buffer. On silica columns, the influence of injection solution on the peak shape and column efficiency was straightforward. The sharpest peaks and the highest column efficiency were obtained with 100% acetonitrile as the injection solvent. On C18 columns, this type of influence was less clear due to the dual retention mechanism of the bonded phase and of the residual silanol groups. On C18 column, retention due to residual silanol groups was significant even with a mobile phase containing less than 50% acetonitrile. Poor peak shape was observed when the injection solution had a stronger eluting strength than mobile phase, particularly for early eluting peaks.
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Affiliation(s)
- W Naidong
- Covance Laboratories Inc., Department of Bioanalytical Chemistry, 3301 Kinsman Boulevard, Madison, WI 53707, USA.
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192
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Shih CC, Shih CM, Chen YL, Su YY, Shih JS, Kwok CF, Lin SJ. Growth inhibition of cultured smooth muscle cells by corrosion products of 316 L stainless steel wire. J Biomed Mater Res 2001; 57:200-7. [PMID: 11484182 DOI: 10.1002/1097-4636(200111)57:2<200::aid-jbm1159>3.0.co;2-5] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
The potential cytotoxicity on vascular smooth muscle cells of corrosion products from 316 L stainless steel, one of most popular biomaterials of intravascular stents, has not been highlighted. In this investigation, 316 L stainless steel wires were corroded in Dulbecco's modified eagle's medium with applied constant electrochemical breakdown voltage, and the supernatant and precipitates of corrosion products were prepared as culture media. The effects of different concentrations of corrosion products on the growth of rat aortic smooth muscle cells were conducted with the [3H]-thymidine uptake test and cell cycle sorter. Both the supernatant and precipitates of corrosion products were toxic to the primary culture of smooth muscle cells. The growth inhibition was correlated well with the increased nickel ions in the corrosion products when nickel concentration was above 11.7 ppm. The corrosion products also changed cell morphology and induced cell necrosis. The cell growth inhibition occurred at the G0/G1 to S transition phase. Similar to our recent study of nitinol stent wire, the present investigation also demonstrated the cytotoxicity of corrosion products of 316 L stainless steel stent wire on smooth muscle cells, which might affect the poststenting vascular response.
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Affiliation(s)
- C C Shih
- Institute of Clinical Medicine, National Yang-Ming University School of Medicine, Taipei 112, Taiwan
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193
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Chen YH, Lin SJ, Ku HH, Shiao MS, Lin FY, Chen JW, Chen YL. Salvianolic acid B attenuates VCAM-1 and ICAM-1 expression in TNF-alpha-treated human aortic endothelial cells. J Cell Biochem 2001; 82:512-21. [PMID: 11500927 DOI: 10.1002/jcb.1176] [Citation(s) in RCA: 142] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Attachment to, and migration of leukocytes into the vessel wall is an early event in atherogenesis. Expression of cell adhesion molecules by the arterial endothelium may play a major role in atherosclerosis. It has been suggested that antioxidants inhibit the expression of adhesion molecules and may thus attenuate the processes leading to atherosclerosis. In the present study, the effects of a potent water-soluble antioxidant, salvianolic acid B (Sal B), and an aqueous ethanolic extract (SME), both derived from a Chinese herb, Salvia miltiorrhiza, on the expression of endothelial-leukocyte adhesion molecules by tumor necrosis factor-alpha (TNF-alpha)-treated human aortic endothelial cells (HAECs) were investigated. When pretreated with SME (50 and 100 microg/ml), the TNF-alpha-induced expression of vascular adhesion molecule-1 (VCAM-1) was notably attenuated (77.2 +/- 3.2% and 80.0 +/- 2.2%, respectively); and with Sal B (1, 2.5, 5, 10, and 20 microg/ml), 84.5 +/- 1.9%, 78.8 +/- 1.2%, 58.9 +/- 0.4%, 58.7 +/- 0.9%, and 57.4 +/- 0.3%, respectively. Dose-dependent lowering of expression of intercellular cell adhesion molecule-1 (ICAM-1) was also seen with SME or Sal B. In contrast, the expression of endothelial cell selectin (E-selectin) was not affected. SME (50 microg/ml) or Sal B (5 microg/ml) significantly reduced the binding of the human monocytic cell line, U937, to TNF-alpha-stimulated HAECs (45.7 +/- 2.5% and 55.8 +/- 1.2%, respectively). SME or Sal B significantly inhibited TNF-alpha-induced activation of nuclear factor kappa B (NF-kappaB) in HAECs (0.36- and 0.48-fold, respectively). These results demonstrate that SME and Sal B have anti-inflammatory properties and may explain their anti-atherosclerotic properties. This new mechanism of action of Sal B and SME, in addition to their previously reported inhibition of LDL, may help explain their efficacy in the treatment of atherosclerosis.
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Affiliation(s)
- Y H Chen
- Institute of Traditional Medicine, National Yang-Ming University, Taipei, Taiwan
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194
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Chen YL, Zhang M, Hua YF, He GQ. [Studies on polysaccharide alkaloids and minerals from Dendrobium moniliforme (L.) Sw]. Zhongguo Zhong Yao Za Zhi 2001; 26:709-10, 4. [PMID: 12776324] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
OBJECTIVE To explore contents of active substances in different part of Dendrobium monilifrome and the quality influenced by different drying processes. METHOD Contents of alkaloids and polysaccharides in upper, middle, lower-stem and root part of Dendrobium moniliforme were determined by uv-spectrophotometer method. Contents of essential trace elements were determined by ICP method. RESULT Contents of polysaccharides and alkaloids were highest in the upper-stem of D. montiliforme. Contents of active substances in different part of D. moniliforme were unequal. Distributions of polysaccharides and alkaloids in different parts were greatly influenced by drying procedures. CONCLUSION Dendrobium moniliforme has higher contents of active ingredients, such as essential tract elements, alkaloids and polysaccharides. The ideal drying process after harvesting is to be the way dried by fire at a high temperature and desiccated at a temperature of 60 degreeC.
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Affiliation(s)
- Y L Chen
- College of Life Science, Zhejiang University, Hangzhou 310012, Zhejiang, China
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195
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Chio CC, Wang YS, Chen YL, Lin SJ, Yang BC. Down-regulation of Fas-L in glioma cells by ribozyme reduces cell apoptosis, tumour-infiltrating cells, and liver damage but accelerates tumour formation in nude mice. Br J Cancer 2001; 85:1185-92. [PMID: 11710833 PMCID: PMC2375147 DOI: 10.1054/bjoc.2001.2055] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Fas-L (CD95L, APO-1L) expresses in a variety of tumours and has been proposed to play a role in tumour formation and metastasis. The contribution of Fas-L to tumour growth, however, is not conclusive especially in systems using cells with over-expressed Fas-L. In this study we down-regulated the expression o Fas-L in human glioma cells by a hammerhead ribozyme (Fas-L(ribozyme)) targeting against Fas-L mRNA. Fas-L(ribozyme)-carrying cells exhibited slightly enhanced growth rate and less degree of spontaneous apoptosis in vitro as compared with vector controls. In nude mice, Fas-L(ribozyme)-carrying cells grew faster with lesser apoptosis, formed bigger tumour with significantly fewer infiltrating cells in the tumour area, and triggered relatively milder tumour-associated liver damage than vector controls did. Thus, down-regulation of Fas-L not only improved viability of glioma cells but also reduces local immune responses that may consequently affect tumour formation. Taken together, our findings imply that endogenous expression of Fas-L in malignant cells is not always growth promoting.
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Affiliation(s)
- C C Chio
- Department of Neurosurgery, Chi-Mei Foundation Hospital, Tainan, Taiwan
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196
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Abstract
Laser-induced gas breakdown and ignition of atmospheric pressure NH3/O2 mixtures are investigated. The nanosecond-pulsed, 1064-nm Nd:YAG laser is used to create the cascade-type optical breakdown. The post-breakdown plasma and ignition are studied using spectroscopic techniques that include spontaneous emission and NH planar laser-induced fluorescence (PLIF). These time-resolved two-dimensional images provide not only radiative and gas dynamic information but also the space-time loci of the temperature and transient species concentrations. The results provide an understanding of the plasma kernel dynamics and the flame development that is essential to verify on-going simulation modeling of laser-ignition.
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197
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Abstract
OBJECTIVE To determine the optimal venous tubing diameter for adult cardiopulmonary bypass (CPB) to improve gravity drainage and to reduce priming volume. METHODS (A) Maximum bovine blood flow rates by gravity drainage were assessed in vitro for four different tubing diameters (1/2, 3/8, 5/16,1/4 inch) with three different lengths and various pre- and afterloads. Based on the results of (A) and multiple regression analyses, we developed equations to predict tubing sizes as a function of target flows. (C) The equations obtained in (B) were validated by ex vivo bovine experiments. (D) The clinically required maximal flows were determined retrospectively by reviewing 119 perfusion records at Zurich University. (E) Based on our model (B), the clinical patient and hardware requirements, the optimal venous tubing diameter was calculated. (F) The optimized venous tubing was evaluated in a prospective clinical trial involving 312 patients in Hangzhou. RESULTS For a mean body surface area of 1.83+/-0.2 m(2), the maximal perfusion flow rate (D) achieved with 1/2-inch (=1.27 cm(2)) venous tubing was 4.62+/-0.57 l/min (range: 2.50-6.24 l/min). Our validated model (B,C) predicted 1.0 cm(2) as optimal cross-sectional area for the venous line. New tubing packs developed accordingly were used routinely thereafter. The maximal flow rate was 4.93+/-0.58 l/min (range: 3.9-7.0) in patients with a mean body surface area of 1.62+/-0.21 m(2). CONCLUSION The new venous tubing with 1.0-cm(2) cross-sectional area improves the drainage in the vast majority of adult patients undergoing CPB and reduces the priming volume (-27 ml/m). Reduced hemodilution can prevent homologous transfusions if a predefined transfusion trigger level is not reached.
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Affiliation(s)
- Y M Ni
- Department of Cardiothoracic Surgery, The First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou, China
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198
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Abstract
This study describes the motivation and the design considerations of an economical head-operated computer mouse. In addition, it focuses on the invention of a head-operated computer mouse that employs two tilt sensors placed in the headset to determine head position and to function as simple head-operated computer mouse. One tilt sensor detects the lateral head-motion to drive the left/right displacement of the mouse. The other one detects the head's vertical motion to move up and down with respect to the displacement of the mouse. A touch switch device was designed to contact gently with operator's cheek. Operator may puff his cheek to trigger the device to perform single click, double clicks, and drag commands. This system was invented to assist people with disabilities to live an independent professional life.
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Affiliation(s)
- Y L Chen
- Department of Electronic Engineering, Hwa-Hsia, College of Technology and Commerce, Taipei Hsien, Taiwan, ROC.
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Chen YL, Yang SP, Shiao MS, Chen JW, Lin SJ. Salvia miltiorrhiza inhibits intimal hyperplasia and monocyte chemotactic protein-1 expression after balloon injury in cholesterol-fed rabbits. J Cell Biochem 2001; 83:484-93. [PMID: 11596116 DOI: 10.1002/jcb.1233] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Antioxidants that prevent low density lipoproteins (LDL) from oxidation may inhibit atherosclerosis and post-angioplasty restenosis. Salvia miltiorrhiza (SM) has been shown to inhibit LDL oxidation and reduce atherosclerosis in cholesterol-fed rabbits. The effects of SM on neointimal hyperplasia and monocyte chemotactic protein-1 (MCP-1) expression after balloon injury were studied. Male New Zealand white rabbits were fed a 2% cholesterol diet together with daily SM (4.8 gm/kg body wt.) treatment (SM; n=10) or without SM as a control (C; n=9) for 6 weeks. Probucol-treated (0.6 gm/kg body wt.) rabbits (P; n=9) were used as a positive control group. A balloon injury of the abdominal aorta was performed at the end of the third week. Aortas were harvested at the end of 6 weeks. The plasma cholesterol levels were lowered in SM group. The neointimal hyperplasia in abdominal aortas was significantly inhibited in SM group [neointima/media area ratio: 0.63+/-0.05 (SM) versus 0.78+/-0.05 (C); P < 0.05] and in P group [0.45+/-0.02 (P) versus 0.78+/-0.05 (C); P < 0.05] when compared with C group. SM treatment significantly reduced MCP-1 mRNA and protein expression in balloon-injured abdominal aorta. These inhibitory effects on intimal response after balloon injury might be attributed to antioxidant capacity and cholesterol lowering effect of SM. SM treatment may offer some protection against post-angioplasty restenosis.
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Affiliation(s)
- Y L Chen
- Institute of Anatomy and Cell Biology, National Yang-Ming University, Taipei, Taiwan
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200
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Shiau AL, Chen YL, Liao CY, Huang YS, Wu CL. Prothymosin alpha enhances protective immune responses induced by oral DNA vaccination against pseudorabies delivered by Salmonella choleraesuis. Vaccine 2001; 19:3947-56. [PMID: 11427270 DOI: 10.1016/s0264-410x(01)00130-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Previously, we showed that vaccination with the glycoprotein D (gD) gene of pseudorabies virus (PrV) delivered by Escherichia coli induced protective immune responses. In this study, we report that oral DNA vaccination with attenuated Salmonella choleraesuis carrying the PrV gD gene conferred protective immunity in mice against PrV. Moreover, co-delivery of the prothymosin alpha gene carried by S. choleraesuis enhanced the vaccine efficacy. Our results thus demonstrate for the first time, to our knowledge, the effectiveness of oral DNA vaccination using S. choleraesuis as a delivery vehicle and the potential usefulness of prothymosin alpha as a DNA vaccine adjuvant.
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MESH Headings
- Adjuvants, Immunologic/administration & dosage
- Adjuvants, Immunologic/genetics
- Administration, Oral
- Animals
- Antibodies, Bacterial/biosynthesis
- Antibodies, Viral/biosynthesis
- Female
- Genetic Vectors
- Herpesvirus 1, Suid/genetics
- Herpesvirus 1, Suid/immunology
- In Vitro Techniques
- Lac Operon
- Lymphocyte Activation
- Mice
- Mice, Inbred BALB C
- Plasmids/genetics
- Promoter Regions, Genetic
- Protein Precursors/administration & dosage
- Protein Precursors/genetics
- Pseudorabies/immunology
- Pseudorabies/prevention & control
- Pseudorabies Vaccines/administration & dosage
- Pseudorabies Vaccines/genetics
- Salmonella/genetics
- Salmonella/immunology
- T-Lymphocytes, Cytotoxic/immunology
- Thymosin/administration & dosage
- Thymosin/analogs & derivatives
- Thymosin/genetics
- Vaccines, DNA/administration & dosage
- Vaccines, DNA/genetics
- Viral Envelope Proteins/genetics
- Viral Envelope Proteins/immunology
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Affiliation(s)
- A L Shiau
- Department of Microbiology, National Cheng Kung University Medical College, Tainan 701, Taiwan.
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