Yu-Ming Liu - Academia.edu (original) (raw)

Papers by Yu-Ming Liu

Plasma Science & Technology, 2001

The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) hav... more The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.

Cheminform, 2004

For Abstract see ChemInform Abstract in Full Text.

Natural Product Research, 2011

A new flavonol glycoside, kaempferol 3-O-α-L-rhamnopyranosyl (1 → 6)-O-[β-D-glucopyranosyl (1 → 2... more A new flavonol glycoside, kaempferol 3-O-α-L-rhamnopyranosyl (1 → 6)-O-[β-D-glucopyranosyl (1 → 2)-O-β-D-galactopyranosyl (1→2)]-O-β-D-glucopyranoside (1), together with a known compound, kaempferol 3-O-β-D-glucopyranosyl (1 → 2)-O-β-D-galactopyranosyl (1 → 2)-O-β-D-glucopyranoside (2) was isolated from the seeds of Nigella glandulifera. Their structures were elucidated on the basis of spectral analysis, including ESI-MS, ESI-MS/MS, HR-ESI-MS, DQF-COSY, TOCSY, HSQC and HMBC techniques.

Chemical & Pharmaceutical Bulletin, 2004

A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the s... more A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the seeds of Nigella glandulifera, together with a known aporphine alkaloid, fuzitine (2). Their structures were established by spectral analysis, including two-dimensional (2D)-NMR spectroscopy. Nigeglanine (1) is the third natural product determined to contain an indazole nucleus.

Molecules, 2006

During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranuncu... more During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranunculaceae) the cytotoxicity of two oleanane triterpene saponins isolated from the seeds of this species, kalopanaxsaponins A and I, was evaluated against HepG2, drug resistant HepG2 (R-HepG2) (two hepatocyte cell lines) and primary cultured normal mouse hepatocytes. Evident cytotoxic activities were observed. Morphological observations and cell cycle analysis suggest that these compounds inhibit the proliferation of hepatoma by inducing apoptosis and consequently kalopanaxsaponins A and I may be potential therapeutic agents for the treatment of parental and drug resistant hepatoma.

International Journal of Radiation Oncology Biology Physics, 2003

Radiopaque gold markers can be implanted in the prostate to visualize its position on portal imag... more Radiopaque gold markers can be implanted in the prostate to visualize its position on portal images during radiation therapy. This procedure assumes that the markers do not move within the prostate. In this work we test this assumptiom. Three markers were implanted transrectally in the prostate of patients undergoing external radiation therapy. An orthogonal pair of portal images was acquired periodically throughout the course of radiation therapy with an a-Si electronic portal imaging device (EPID). The marker coordinates were determined, and the distances between the implanted markers were recorded. The distance time trend is used to evaluate the magnitude of marker migration. The average standard deviation (SD) of the distances between markers was 1.3 mm (range 0.44 to 3.04 mm). Three of the 11 patients show a SD larger than 2 mm. For these patients, all three distances show a simultaneous reduction with time, compatible with a shrinking of the prostate. All had been treated with neoadjuvant hormone therapy. For 1 of the 3 patients, this reduction in volume was confirmed with a repeat computed tomographic scan. None of the 33 markers studied migrated significantly. The implantation of three radiopaque gold markers enables accurate and precise on-line verification of the prostate position during external beam radiation therapy. The use of three markers provides a tool to monitor prostate position and volume changes that can occur over time due to hormone or radiation therapy.

International Journal of Radiation Oncology Biology Physics, 2004

Retrograde urethrography (UG) is commonly used at the time of simulation to assist in defining th... more Retrograde urethrography (UG) is commonly used at the time of simulation to assist in defining the prostate apex. Some investigators have reported that performing the UG introduces error by causing prostate displacement. We investigate the movement of the prostate caused by the retrograde UG. Twenty-four patients treated with three-dimensional conformal radiotherapy for prostate cancer who had gold marker seeds placed into their prostates were studied. Marker seed locations at the time of simulation and on the portal images acquired just before the treatment were compared with the locations on digitally reconstructed radiographs (DRR). Movement in the superior-inferior and anteroposterior directions as seen on lateral images was measured from 402 portal images by offline customized imaging software and evaluated using analysis of variance methods for continuous variables and chi-square statistics for categoric variables. "Natural" nonrandom movement of the prostate around an "origin" as defined by markers on DRR was observed. This movement tends to be in a superior and anterior direction, with the average shift being 1 mm and 0.82 mm, respectively. The magnitude of movement in the superior direction averaged 2.88 mm compared with 1.64 mm in the inferior direction (p = 0.04). There was slightly greater movement after the UG compared with mean "natural" movement but the difference was less than 3 mm in either direction on average (difference: superior-inferior = 2.64 mm, p = 0.004; anteroposterior = 2.24, p = 0.035). Use of the UG induces a small but clinically insignificant displacement of the prostate when "natural" movement is taken into account.

International Journal of Radiation Oncology Biology Physics, 2004

The purpose of this study was to develop and test planning dose constraint templates for tumor an... more The purpose of this study was to develop and test planning dose constraint templates for tumor and normal structures in the treatment of nasopharyngeal carcinoma (NPC) using a specific commercial inverse treatment planning system. Planning dose constraint templates were developed based on the analyses of dose-volume histograms (DVHs) of tumor targets and adjacent sensitive structures by clinically approved treatment plans of 9 T1-2 and 16 T3-4 NPC patients treated with inverse planned intensity-modulated radiation therapy (IP-IMRT). DVHs of sensitive structures were analyzed by examining multiple defined endpoints, based on the characteristics of each sensitive structure. For each subgroup of patients with T1-2 and T3-4 NPC, the resulting mean values of these defined endpoint doses were considered as templates for planning dose constraints and subsequently applied to a second group of patients, 5 with T1-2 NPC and 5 with T3-4 NPC. The 10 regenerated plans (called new plans) were compared to the original clinical plans that were used to treat the second group of patients, based on plan conformity index and DVHs. The conformity indices of the new plans were comparable to the original plans with no statistical difference (p = 0.85). Among the serial sensitive structures evaluated, there was a significant decrease with the new plans in the dose to the spinal cord when analyzed by the maximum dose (p = 0.001), doses encompassing 1 cc of the spinal cord volume (p = 0.001) and 3 cc of the spinal cord volume (p = 0.001). There was no significant difference in the mean maximum dose to the brainstem between the new plans and the original plans (p = 0.36). However, a significant difference in the mean maximum dose to the brainstem was seen among the different T-stages (p = 0.04). A decrease with the new plan to the brainstem in the doses encompassing 5% and 10% of the volume was of borderline statistical significance (p = 0.08 and p = 0.06, respectively). There were no statistical differences between the new plans and the original plans in the mean doses to the chiasm, optic nerve, or eye for each of the endpoints considered. For parallel sensitive structures in the new plans, there was a significant increase in the average mean dose to the parotid glands (p = 0.01), a decrease that was of borderline significance in the average mean dose to the temporomandibular joint (p = 0.07), but no difference in the average mean dose to the ear. The statistical analysis showed that new plans are comparable to the original plans for most of the sensitive structures except for a trade-off between a dose reduction to the spinal cord in the new plans and an increase in the mean dose to the parotid glands. These tested planning dose constraint templates can serve as good "starting points" for an inverse plan of NPC using a specific commercial inverse treatment planning system.

Investigating the recent direct action campaigns against genetically modified crops in France and... more Investigating the recent direct action campaigns against genetically modified crops in France and the United Kingdom, the authors set out to understand how contrasting judicial systems and cultures affect the way that activists choose to commit ostensibly illegal actions and how they negotiate the trade-offs between effectiveness and public accountability. The authors find evidence that prosecution outcomes across different judicial systems are consistent and relatively predictable and consequently argue that the concept of a "judicial opportunity structure" is useful for developing scholars' understanding of social movement trajectories. The authors also find that these differential judicial opportunities cannot adequately account for the tactical choices made by activists with respect to the staging of covert or overt direct action; rather, explanations of tactical choice are better accounted for by movement ideas, cultures, and traditions.

Plasma Science & Technology, 2001

The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) hav... more The aging effects of the contact angle and surface energy on polyethylene terephthalate (PET) have been investigated with surface modification by water vapor plasma. The experimental results show that the contact angle of water and PET decreases obviously and surface energy increases. However, with the increase of the aging time, the contact angle and surface energy change back gradually to original state.

Cheminform, 2004

For Abstract see ChemInform Abstract in Full Text.

Natural Product Research, 2011

A new flavonol glycoside, kaempferol 3-O-α-L-rhamnopyranosyl (1 → 6)-O-[β-D-glucopyranosyl (1 → 2... more A new flavonol glycoside, kaempferol 3-O-α-L-rhamnopyranosyl (1 → 6)-O-[β-D-glucopyranosyl (1 → 2)-O-β-D-galactopyranosyl (1→2)]-O-β-D-glucopyranoside (1), together with a known compound, kaempferol 3-O-β-D-glucopyranosyl (1 → 2)-O-β-D-galactopyranosyl (1 → 2)-O-β-D-glucopyranoside (2) was isolated from the seeds of Nigella glandulifera. Their structures were elucidated on the basis of spectral analysis, including ESI-MS, ESI-MS/MS, HR-ESI-MS, DQF-COSY, TOCSY, HSQC and HMBC techniques.

Chemical & Pharmaceutical Bulletin, 2004

A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the s... more A new compound, nigeglanine (1), and its new artificial derivative (1a), were isolated from the seeds of Nigella glandulifera, together with a known aporphine alkaloid, fuzitine (2). Their structures were established by spectral analysis, including two-dimensional (2D)-NMR spectroscopy. Nigeglanine (1) is the third natural product determined to contain an indazole nucleus.

Molecules, 2006

During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranuncu... more During an investigation of antitumor substances from Nigella glandulifera Freyn et Sint. (Ranunculaceae) the cytotoxicity of two oleanane triterpene saponins isolated from the seeds of this species, kalopanaxsaponins A and I, was evaluated against HepG2, drug resistant HepG2 (R-HepG2) (two hepatocyte cell lines) and primary cultured normal mouse hepatocytes. Evident cytotoxic activities were observed. Morphological observations and cell cycle analysis suggest that these compounds inhibit the proliferation of hepatoma by inducing apoptosis and consequently kalopanaxsaponins A and I may be potential therapeutic agents for the treatment of parental and drug resistant hepatoma.

International Journal of Radiation Oncology Biology Physics, 2003

Radiopaque gold markers can be implanted in the prostate to visualize its position on portal imag... more Radiopaque gold markers can be implanted in the prostate to visualize its position on portal images during radiation therapy. This procedure assumes that the markers do not move within the prostate. In this work we test this assumptiom. Three markers were implanted transrectally in the prostate of patients undergoing external radiation therapy. An orthogonal pair of portal images was acquired periodically throughout the course of radiation therapy with an a-Si electronic portal imaging device (EPID). The marker coordinates were determined, and the distances between the implanted markers were recorded. The distance time trend is used to evaluate the magnitude of marker migration. The average standard deviation (SD) of the distances between markers was 1.3 mm (range 0.44 to 3.04 mm). Three of the 11 patients show a SD larger than 2 mm. For these patients, all three distances show a simultaneous reduction with time, compatible with a shrinking of the prostate. All had been treated with neoadjuvant hormone therapy. For 1 of the 3 patients, this reduction in volume was confirmed with a repeat computed tomographic scan. None of the 33 markers studied migrated significantly. The implantation of three radiopaque gold markers enables accurate and precise on-line verification of the prostate position during external beam radiation therapy. The use of three markers provides a tool to monitor prostate position and volume changes that can occur over time due to hormone or radiation therapy.

International Journal of Radiation Oncology Biology Physics, 2004

Retrograde urethrography (UG) is commonly used at the time of simulation to assist in defining th... more Retrograde urethrography (UG) is commonly used at the time of simulation to assist in defining the prostate apex. Some investigators have reported that performing the UG introduces error by causing prostate displacement. We investigate the movement of the prostate caused by the retrograde UG. Twenty-four patients treated with three-dimensional conformal radiotherapy for prostate cancer who had gold marker seeds placed into their prostates were studied. Marker seed locations at the time of simulation and on the portal images acquired just before the treatment were compared with the locations on digitally reconstructed radiographs (DRR). Movement in the superior-inferior and anteroposterior directions as seen on lateral images was measured from 402 portal images by offline customized imaging software and evaluated using analysis of variance methods for continuous variables and chi-square statistics for categoric variables. "Natural" nonrandom movement of the prostate around an "origin" as defined by markers on DRR was observed. This movement tends to be in a superior and anterior direction, with the average shift being 1 mm and 0.82 mm, respectively. The magnitude of movement in the superior direction averaged 2.88 mm compared with 1.64 mm in the inferior direction (p = 0.04). There was slightly greater movement after the UG compared with mean "natural" movement but the difference was less than 3 mm in either direction on average (difference: superior-inferior = 2.64 mm, p = 0.004; anteroposterior = 2.24, p = 0.035). Use of the UG induces a small but clinically insignificant displacement of the prostate when "natural" movement is taken into account.

International Journal of Radiation Oncology Biology Physics, 2004

The purpose of this study was to develop and test planning dose constraint templates for tumor an... more The purpose of this study was to develop and test planning dose constraint templates for tumor and normal structures in the treatment of nasopharyngeal carcinoma (NPC) using a specific commercial inverse treatment planning system. Planning dose constraint templates were developed based on the analyses of dose-volume histograms (DVHs) of tumor targets and adjacent sensitive structures by clinically approved treatment plans of 9 T1-2 and 16 T3-4 NPC patients treated with inverse planned intensity-modulated radiation therapy (IP-IMRT). DVHs of sensitive structures were analyzed by examining multiple defined endpoints, based on the characteristics of each sensitive structure. For each subgroup of patients with T1-2 and T3-4 NPC, the resulting mean values of these defined endpoint doses were considered as templates for planning dose constraints and subsequently applied to a second group of patients, 5 with T1-2 NPC and 5 with T3-4 NPC. The 10 regenerated plans (called new plans) were compared to the original clinical plans that were used to treat the second group of patients, based on plan conformity index and DVHs. The conformity indices of the new plans were comparable to the original plans with no statistical difference (p = 0.85). Among the serial sensitive structures evaluated, there was a significant decrease with the new plans in the dose to the spinal cord when analyzed by the maximum dose (p = 0.001), doses encompassing 1 cc of the spinal cord volume (p = 0.001) and 3 cc of the spinal cord volume (p = 0.001). There was no significant difference in the mean maximum dose to the brainstem between the new plans and the original plans (p = 0.36). However, a significant difference in the mean maximum dose to the brainstem was seen among the different T-stages (p = 0.04). A decrease with the new plan to the brainstem in the doses encompassing 5% and 10% of the volume was of borderline statistical significance (p = 0.08 and p = 0.06, respectively). There were no statistical differences between the new plans and the original plans in the mean doses to the chiasm, optic nerve, or eye for each of the endpoints considered. For parallel sensitive structures in the new plans, there was a significant increase in the average mean dose to the parotid glands (p = 0.01), a decrease that was of borderline significance in the average mean dose to the temporomandibular joint (p = 0.07), but no difference in the average mean dose to the ear. The statistical analysis showed that new plans are comparable to the original plans for most of the sensitive structures except for a trade-off between a dose reduction to the spinal cord in the new plans and an increase in the mean dose to the parotid glands. These tested planning dose constraint templates can serve as good "starting points" for an inverse plan of NPC using a specific commercial inverse treatment planning system.

Investigating the recent direct action campaigns against genetically modified crops in France and... more Investigating the recent direct action campaigns against genetically modified crops in France and the United Kingdom, the authors set out to understand how contrasting judicial systems and cultures affect the way that activists choose to commit ostensibly illegal actions and how they negotiate the trade-offs between effectiveness and public accountability. The authors find evidence that prosecution outcomes across different judicial systems are consistent and relatively predictable and consequently argue that the concept of a "judicial opportunity structure" is useful for developing scholars' understanding of social movement trajectories. The authors also find that these differential judicial opportunities cannot adequately account for the tactical choices made by activists with respect to the staging of covert or overt direct action; rather, explanations of tactical choice are better accounted for by movement ideas, cultures, and traditions.