为解决异构的服务机器人团队为多位老人服务时的协调问题以及在此过程中如何最大化老人的总体满意度,提出了一种服务于多人的多机器人−多任务协调框架.首先,结合时延Petri网和颜色Petri网提出了可扩展时延−颜色Petri网(Scalable timed-c...为解决异构的服务机器人团队为多位老人服务时的协调问题以及在此过程中如何最大化老人的总体满意度,提出了一种服务于多人的多机器人−多任务协调框架.首先,结合时延Petri网和颜色Petri网提出了可扩展时延−颜色Petri网(Scalable timed-colored Petri net,STdCPN)对养老院情境下服务机器人照顾老人的过程进行建模.然后,将老人的感受和情绪作为机器人照顾老人时的重要指标,构建了服务对象满意度模型.最后,设计智能体来实现该协调框架的调度,该智能体通过考虑老人“个人因素”和机器人的实时状态、位置等信息来对任务进行合理的规划调度,使机器人帮助老人完成任务的同时,最大化老人总体满意度.展开更多
Background Dysembryoplastic neuroepithelial tumor （DNT） is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies an...Background Dysembryoplastic neuroepithelial tumor （DNT） is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies and improving prognosis. The purpose of this study was to characterize DNTs using magnetic resonance imaging （MRI） and magnetic resonance spectroscopy （MRS） and to analyze the value of these two techniques in the diagnosis of DNTs. Methods MR images of 13 patients with DNTs were reviewed retrospectively; and five of the patients also underwent MRS. Tumors were confirmed by surgery. The distribution, extension and signal features of the lesions were assessed, and the MRS results were analyzed. Results All tumors were supratentorial. The cortex was the main area involved, with nine tumors located in the temporal lobe, three in the frontal lobe, and one on the boundary between the temporal and occipital lobes. All cases had decreased signal intensity on Tl-weighted MR images and increased signal intensity on T2-weighted images. On fluid attenuated inversion recovery weighted images, the hyperintense ＂ring sign＂ and internal septation of the lesion were seen in 9 cases. Eight tumors had well-demarcated borders. Peritumoral edema or mass effect was absent in all cases. A contrast enhancement examination was performed in 9 cases. Contrast enhancement was absent in five cases, and four cases showed significant enhancement. The MRS showed a low N-acetylaspartate peak and a lack of elevated choline-containing component （Cho） or Cho-Cr ratio （Cho/Cr） in five patients. Conclusions The MRI findings of DNTs were stereotypical. The combination of MRI and MRS techniques were helpful in making a correct presurgical diagnosis.展开更多
Malignant meningiomas are uncommon intracranial tumors. The metastasis of malignant meningiomas to distant extracranial sites are well known. However, dissemination of the tumours in the cerebrospinal fluid （CSF） is...Malignant meningiomas are uncommon intracranial tumors. The metastasis of malignant meningiomas to distant extracranial sites are well known. However, dissemination of the tumours in the cerebrospinal fluid （CSF） is rare and few cases have been reported. We present a case of histologically proven malignant meningioma with CSF dissemination at the remote intracranial area and into the spinal canal detected with maqnetic resonance imaging.展开更多
Background Using magnetic resonance imaging, diagnosis of malignant meningioma from benign meningioma with atypical features is uncertain. We evaluated the value of lipid signal in differentiating intracranial meningi...Background Using magnetic resonance imaging, diagnosis of malignant meningioma from benign meningioma with atypical features is uncertain. We evaluated the value of lipid signal in differentiating intracranial meningiomas. Methods ^1H-magnetic resonance spectroscopy （MRS） using a point resolved spectroscopy （TR/TE 1000/144 ms） sequences were performed on 34 patients on a 3.0 T scanner. Lipid peak located at 1.3 ppm was evaluated. MRS data from these tumours were compared with histopathological findings （including hematoxylin and eosin staining and KP-1 staining）. Results Twenty-nine meningiomas were histologically benign （eleven meningothelial, thirteen fibrous, four transitional and one microcystic）, three were atypical, and two were anaplastic. Lipid signal was detected in ten cases： two anaplastic three atypical, two fibrous and three rneningothelial meningiomas. All voxels with lipid peak in the spectrum from the tumour were evaluated. With creatinine peak in the normal white matter chosen as internal standard, lipid/creatinine ratios of anaplastic, atypical and benign meningiomas were 0.844±0.027 （range from 0.725 to 0.994）, 0.465±0.023 （range from 0.239 to 0.724）, and 0.373±0.016 （range from 0.172 to 0.571） respectively. Highly significant differences were noted between anaplastic and the other two subtypes. Patchy necrosis was observed in anaplastic meningioma, while focal necrosis was noted in atypical meningioma with HE stain. However, no necrosis was found in benign group. KP-1 stain demonstrated histocytes containing lipids in the necrotic region of anaplastic and atypical meningioma. Conclusion The lipid signal at 1.3 ppm is a useful marker in evaluating the malignancy of intracranial meningiomas, especially in the differential diagnosis of anaplastic meningioma.展开更多
Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocamp...Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.展开更多
文摘为解决异构的服务机器人团队为多位老人服务时的协调问题以及在此过程中如何最大化老人的总体满意度,提出了一种服务于多人的多机器人−多任务协调框架.首先,结合时延Petri网和颜色Petri网提出了可扩展时延−颜色Petri网(Scalable timed-colored Petri net,STdCPN)对养老院情境下服务机器人照顾老人的过程进行建模.然后,将老人的感受和情绪作为机器人照顾老人时的重要指标,构建了服务对象满意度模型.最后,设计智能体来实现该协调框架的调度,该智能体通过考虑老人“个人因素”和机器人的实时状态、位置等信息来对任务进行合理的规划调度,使机器人帮助老人完成任务的同时,最大化老人总体满意度.
文摘Background Dysembryoplastic neuroepithelial tumor （DNT） is a rare benign neoplasm of the central nervous system affecting young people. A correct preoperative diagnosis is helpful for planning surgical strategies and improving prognosis. The purpose of this study was to characterize DNTs using magnetic resonance imaging （MRI） and magnetic resonance spectroscopy （MRS） and to analyze the value of these two techniques in the diagnosis of DNTs. Methods MR images of 13 patients with DNTs were reviewed retrospectively; and five of the patients also underwent MRS. Tumors were confirmed by surgery. The distribution, extension and signal features of the lesions were assessed, and the MRS results were analyzed. Results All tumors were supratentorial. The cortex was the main area involved, with nine tumors located in the temporal lobe, three in the frontal lobe, and one on the boundary between the temporal and occipital lobes. All cases had decreased signal intensity on Tl-weighted MR images and increased signal intensity on T2-weighted images. On fluid attenuated inversion recovery weighted images, the hyperintense ＂ring sign＂ and internal septation of the lesion were seen in 9 cases. Eight tumors had well-demarcated borders. Peritumoral edema or mass effect was absent in all cases. A contrast enhancement examination was performed in 9 cases. Contrast enhancement was absent in five cases, and four cases showed significant enhancement. The MRS showed a low N-acetylaspartate peak and a lack of elevated choline-containing component （Cho） or Cho-Cr ratio （Cho/Cr） in five patients. Conclusions The MRI findings of DNTs were stereotypical. The combination of MRI and MRS techniques were helpful in making a correct presurgical diagnosis.
文摘Malignant meningiomas are uncommon intracranial tumors. The metastasis of malignant meningiomas to distant extracranial sites are well known. However, dissemination of the tumours in the cerebrospinal fluid （CSF） is rare and few cases have been reported. We present a case of histologically proven malignant meningioma with CSF dissemination at the remote intracranial area and into the spinal canal detected with maqnetic resonance imaging.
文摘Background Using magnetic resonance imaging, diagnosis of malignant meningioma from benign meningioma with atypical features is uncertain. We evaluated the value of lipid signal in differentiating intracranial meningiomas. Methods ^1H-magnetic resonance spectroscopy （MRS） using a point resolved spectroscopy （TR/TE 1000/144 ms） sequences were performed on 34 patients on a 3.0 T scanner. Lipid peak located at 1.3 ppm was evaluated. MRS data from these tumours were compared with histopathological findings （including hematoxylin and eosin staining and KP-1 staining）. Results Twenty-nine meningiomas were histologically benign （eleven meningothelial, thirteen fibrous, four transitional and one microcystic）, three were atypical, and two were anaplastic. Lipid signal was detected in ten cases： two anaplastic three atypical, two fibrous and three rneningothelial meningiomas. All voxels with lipid peak in the spectrum from the tumour were evaluated. With creatinine peak in the normal white matter chosen as internal standard, lipid/creatinine ratios of anaplastic, atypical and benign meningiomas were 0.844±0.027 （range from 0.725 to 0.994）, 0.465±0.023 （range from 0.239 to 0.724）, and 0.373±0.016 （range from 0.172 to 0.571） respectively. Highly significant differences were noted between anaplastic and the other two subtypes. Patchy necrosis was observed in anaplastic meningioma, while focal necrosis was noted in atypical meningioma with HE stain. However, no necrosis was found in benign group. KP-1 stain demonstrated histocytes containing lipids in the necrotic region of anaplastic and atypical meningioma. Conclusion The lipid signal at 1.3 ppm is a useful marker in evaluating the malignancy of intracranial meningiomas, especially in the differential diagnosis of anaplastic meningioma.
文摘Background Diffusion tensor imaging （DTI） is a noninvasive imaging technique for the assessment of the integrity of cerebral tissues. This study was undertaken to assess the changes of diffusion indices of hippocampal formation （HF） in patients with medial temporal lobe epilepsy （MTLE）. Methods Fourteen patients with MTLE and 14 healthy subjects were evaluated. Mean diffusivity （MD） and fractional anisotropy （FA） from the symmetrical-voxel sampling regions of the anterior HF were calculated in all subjects. The MD and FA values were compared across the groups. Results No significant differences of MD and FA values were noted between right and left HF in the controls. In the patient group, MD significantly increased in the HF ipsilateral to the lesioned side [（9.27±1.09）×10^-4 mm^2/s], compared with the values in the contralateral HF [（8.20±0.59）×10^-4 min^2]s] （t = 4.479, P = 0.001） and healthy subjects [（7.58±0.51）×10^-4 mm^2/s] （P 〈 0.001）, but no significant differences were found in FA. When compared with the controls, patients had a significantly higher MD in the contralateral HF （P 〈 0.05）, but the difference in FA was not statistically significant. Conclusions DTI could detect hippocampal abnormality in patients with MTLE. This technique may be helpful for preoperative evaluation of such patients.
