Background: The distribution of forest vegetation within urban environments is critically important as it influences urban environmental conditions and the energy exchange through the absorption of solar radiation and...Background: The distribution of forest vegetation within urban environments is critically important as it influences urban environmental conditions and the energy exchange through the absorption of solar radiation and modulation of evapotranspiration. It also plays an important role filtering urban water systems and reducing storm water runoff.Methods: We investigate the capacity of ALS data to individually detect, map and characterize large(taller than15 m) trees within the City of Vancouver. Large trees are critical for the function and character of Vancouver’s urban forest. We used an object-based approach for individual tree detection and segmentation to determine tree locations(position of the stem), to delineate the shape of the crowns and to categorize the latter either as coniferous or deciduous.Results: Results indicate a detection rate of 76.6% for trees > 15 m with a positioning error of 2.11 m(stem location). Extracted tree heights possessed a RMSE of 2.60 m and a bias of-1.87 m, whereas crown diameter was derived with a RMSE of 3.85 m and a bias of-2.06 m. Missed trees are principally a result of undetected treetops occurring in dense, overlapping canopies with more accurate detection and delineation of trees in open areas.Conclusion: By identifying key structural trees across Vancouver’s urban forests, we can better understand their role in providing ecosystem goods and services for city residents.展开更多
Problems in desulfurization of coal by electrochemical reduction is analyzed and calculated. The result shows that 1 ) the △rGm function of the reaction of pyrite into FeS and the modifying reaction decreasing the ox...Problems in desulfurization of coal by electrochemical reduction is analyzed and calculated. The result shows that 1 ) the △rGm function of the reaction of pyrite into FeS and the modifying reaction decreasing the oxygenous functions on coal surface is smaller than zero in a spontaneous reaction, and greater than zero in a non-spontaneous reaction; 2) the △rGm value can be adjusted by pH and the dosage of electrolyte to make it be greaterthan zero , which is favorable for the modifying reaction and useful for desulfurization of coal. The research has provided a theoretical foundation for determining reasonable technical parameters of desulfurization。展开更多
BACKGROUND： Thyroid hormones modulate proliferation of astrocytes and microglia depending on maturation stage and localization. Studies have demonstrated that triiodothyronine treatment or thyroidectomy during develo...BACKGROUND： Thyroid hormones modulate proliferation of astrocytes and microglia depending on maturation stage and localization. Studies have demonstrated that triiodothyronine treatment or thyroidectomy during developmental stages results in morphological alterations and changes in the number of astrocytes and microglia. Little is known about the effects of hypothyroidism on astrocytes and microglia in adults. OBJECTIVE： To investigate the effects of hypothyroidism on morphology and number of astrocytes and microglia in the adult rat hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, neuroendocrinological, animal study was performed at the College of Medicine, Hallym University, South Korea between May 2008 and April 2009. MATERIALS： Methimazole, rabbit anti-glial fibrillary acidic protein （GFAP） antiserum, and rabbit anti-lba-1 antiserum were purchased from Sigma, USA. Rabbit anti-GFAP polyclonal antibody was provided by Chemicon, USA. Rabbit anti-lba-1 polyclonal antibody was purchased from Wako, Japan. Terminal deoxynucleotidyl transferase dUTP-biotin nick-end-labeling （TUNEL） kit was provided by Roche Molecular Biochemicals, Mannheim, Germany. METHODS： Hypothyroidism was induced in Wistar rats via methimazole administration （0.025%） in drinking water for 5 weeks, starting at 6 months of age. MAIN OUTCOME MEASURES： Following methimazole treatment, hippocampai neuronal death was determined using TUNEL staining. The morphology and number of GFAP and lba-1 immunoreactive cells were detected by immunohistochemistry. Hippocampal GFAP and lba-1 protein levels were detected by Western blot analysis. Serum-free triiodothyronine and thyroxine levels were quantified. RESULTS： TUNEL-positive neurons were not observed in the hippocampus of euthyroid and hypothyroid rats. Compared with the euthyroid rats, the number of GFAP immunoreactive astrocytes was decreased, and serum triiodothyronine and thyroxine levels were significantly decreased. In contrast, the number of lba-1 immunoreactive microglia was significantly increased in the hypothyroid rats （P 〈 0.05）. In addition, GFAP immunoreactive astrocytes were morphologically at a resting state, and lba-1 immunoreactive microglia were morphologically hypertrophic. GFAP and IBa-1 protein changes in the hippocampus of euthyroid and hypothyroid rats were in accordance with immunohistochemical data. CONCLUSION： Although methimazole-induced hypothyroidism did not induce neuronal injury in the adult rat hippocampus, it did result in decreased astrocyte numbers and increased microglial hypertrophy.展开更多
Soluble and ordered ladder like polyphenylsilsesquioxane was synthesized by a two-step sol-gel method including hydrolysis and polycondensation. The procedure was monitored by Fourier transform infrared spectroscopy a...Soluble and ordered ladder like polyphenylsilsesquioxane was synthesized by a two-step sol-gel method including hydrolysis and polycondensation. The procedure was monitored by Fourier transform infrared spectroscopy and the presence of the ladder like structure was confirmed by X-ray techniques. 29Si NMR analysis shows a very narrow half peak width（δ4） at δ –78.866 of the main chain unit C6H5SiO3/2 of polyphenylsilsesquioxane, indicating that the polyphenylsilsesquioxane has ordered ladder like structures rather than the branched ones. The relationship between molecular weight and the time of polycondensation was also discussed.展开更多
It was found for the first time that the compounds with only one functional group, such as pyridine, can show the promotion effect for the electrochemical reaction of cytochrome C at gold electrodes.
This paper studies mainly how to make use of Multi- Agent technology to solve the complex problems which are caused by unsuitable coordination between protection and untimely action and protection fault activity in la...This paper studies mainly how to make use of Multi- Agent technology to solve the complex problems which are caused by unsuitable coordination between protection and untimely action and protection fault activity in large power system, and realizes timely the coordination among protections effectively in when losing some or all information. Thus it overcomes the difficult of solving single or shore range information, enhances correspond and coordination among the intelligent protect Agent, raises the stable and reliable property, and promotes the process of power network for large area.展开更多
Background： It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease （CAD）. Coronary endarterectomy （CE） offers an alternative choice of coronary...Background： It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease （CAD）. Coronary endarterectomy （CE） offers an alternative choice of coronary artery reconstruction and revascularization. In this study, short-term result of CE combined with coronary artery bypass graft （CABG） was discussed in the treatment for the diffused CAD. Methods： From January 2012 to April 2014, 221 cases of CABG were performed by the same surgeon in our unit. Among these cases, 38 cases of CE ＋ CABG were pertbrmed, which was about 17.2% （38/221） of the cohort. All these patients were divided into two groups： CE ＋ CABG group （Group A） and CABG alone group and postoperative complications and in-hospital mortality were Chi-square test and Student＇s t-test respectively. （Group B）. All clinical data were compared between the two groups, analyzed. The categorical and continuous variables were analyzed by Results： Diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease were more common in group A. In this cohort, a total of 50 vessels were endarterectomized. Among them, CE was perfbrmed on left anterior descending artery in 11 cases, on right coronary artery in 29 cases, on diagonal artery in 3 cases, on intermediate artery in 2 cases, on obtuse marginal artery in 5 cases. There was no hospital mortality in both groups. The intro-aortic balloon pump was required in 3 cases in Group A （3/38）, which was more often than that in Group B （3/183）. At the time of follow-up, coronary computed tomography angiogram showed all the grafts with CE were patent （50/50）. There is no cardio-related mortality in both groups. All these patients were free from coronary re-intervention. Conclusions： Coronary endarterectomy ＋ CABG can oilier satisfactory result for patients with diffused CAD in a short-term after the operation.展开更多
To the Editor： Endometriosis is a common gynecologic condition that affects approximately 10% of females of reproductive age. It is a chronic inflammatory disease that is defined by the presence of endometrial-like t...To the Editor： Endometriosis is a common gynecologic condition that affects approximately 10% of females of reproductive age. It is a chronic inflammatory disease that is defined by the presence of endometrial-like tissue outside the uterine cavity. Endometriosis commonly occurs in the peritoneum, ovaries, and rectovaginal septum, but may also be found in other abdominal or extra-abdominal sites.展开更多
文摘Background: The distribution of forest vegetation within urban environments is critically important as it influences urban environmental conditions and the energy exchange through the absorption of solar radiation and modulation of evapotranspiration. It also plays an important role filtering urban water systems and reducing storm water runoff.Methods: We investigate the capacity of ALS data to individually detect, map and characterize large(taller than15 m) trees within the City of Vancouver. Large trees are critical for the function and character of Vancouver’s urban forest. We used an object-based approach for individual tree detection and segmentation to determine tree locations(position of the stem), to delineate the shape of the crowns and to categorize the latter either as coniferous or deciduous.Results: Results indicate a detection rate of 76.6% for trees > 15 m with a positioning error of 2.11 m(stem location). Extracted tree heights possessed a RMSE of 2.60 m and a bias of-1.87 m, whereas crown diameter was derived with a RMSE of 3.85 m and a bias of-2.06 m. Missed trees are principally a result of undetected treetops occurring in dense, overlapping canopies with more accurate detection and delineation of trees in open areas.Conclusion: By identifying key structural trees across Vancouver’s urban forests, we can better understand their role in providing ecosystem goods and services for city residents.
基金National Natural Science Foundation of China(50174054)
文摘Problems in desulfurization of coal by electrochemical reduction is analyzed and calculated. The result shows that 1 ) the △rGm function of the reaction of pyrite into FeS and the modifying reaction decreasing the oxygenous functions on coal surface is smaller than zero in a spontaneous reaction, and greater than zero in a non-spontaneous reaction; 2) the △rGm value can be adjusted by pH and the dosage of electrolyte to make it be greaterthan zero , which is favorable for the modifying reaction and useful for desulfurization of coal. The research has provided a theoretical foundation for determining reasonable technical parameters of desulfurization。
基金Supported by the Korea Research Foundation Grant funded by the Korean Government (MOEHRD,Basic Research Promotion Fund), No. KRF-2007-412-J00502
文摘BACKGROUND： Thyroid hormones modulate proliferation of astrocytes and microglia depending on maturation stage and localization. Studies have demonstrated that triiodothyronine treatment or thyroidectomy during developmental stages results in morphological alterations and changes in the number of astrocytes and microglia. Little is known about the effects of hypothyroidism on astrocytes and microglia in adults. OBJECTIVE： To investigate the effects of hypothyroidism on morphology and number of astrocytes and microglia in the adult rat hippocampus. DESIGN, TIME AND SETTING： A randomized, controlled, neuroendocrinological, animal study was performed at the College of Medicine, Hallym University, South Korea between May 2008 and April 2009. MATERIALS： Methimazole, rabbit anti-glial fibrillary acidic protein （GFAP） antiserum, and rabbit anti-lba-1 antiserum were purchased from Sigma, USA. Rabbit anti-GFAP polyclonal antibody was provided by Chemicon, USA. Rabbit anti-lba-1 polyclonal antibody was purchased from Wako, Japan. Terminal deoxynucleotidyl transferase dUTP-biotin nick-end-labeling （TUNEL） kit was provided by Roche Molecular Biochemicals, Mannheim, Germany. METHODS： Hypothyroidism was induced in Wistar rats via methimazole administration （0.025%） in drinking water for 5 weeks, starting at 6 months of age. MAIN OUTCOME MEASURES： Following methimazole treatment, hippocampai neuronal death was determined using TUNEL staining. The morphology and number of GFAP and lba-1 immunoreactive cells were detected by immunohistochemistry. Hippocampal GFAP and lba-1 protein levels were detected by Western blot analysis. Serum-free triiodothyronine and thyroxine levels were quantified. RESULTS： TUNEL-positive neurons were not observed in the hippocampus of euthyroid and hypothyroid rats. Compared with the euthyroid rats, the number of GFAP immunoreactive astrocytes was decreased, and serum triiodothyronine and thyroxine levels were significantly decreased. In contrast, the number of lba-1 immunoreactive microglia was significantly increased in the hypothyroid rats （P 〈 0.05）. In addition, GFAP immunoreactive astrocytes were morphologically at a resting state, and lba-1 immunoreactive microglia were morphologically hypertrophic. GFAP and IBa-1 protein changes in the hippocampus of euthyroid and hypothyroid rats were in accordance with immunohistochemical data. CONCLUSION： Although methimazole-induced hypothyroidism did not induce neuronal injury in the adult rat hippocampus, it did result in decreased astrocyte numbers and increased microglial hypertrophy.
基金Supported by the National Natural Science Foundation of China(No.51073020)the Program for Changjiang Scholars and Innovative Research Team in University of China(No.IRT0706)
文摘Soluble and ordered ladder like polyphenylsilsesquioxane was synthesized by a two-step sol-gel method including hydrolysis and polycondensation. The procedure was monitored by Fourier transform infrared spectroscopy and the presence of the ladder like structure was confirmed by X-ray techniques. 29Si NMR analysis shows a very narrow half peak width（δ4） at δ –78.866 of the main chain unit C6H5SiO3/2 of polyphenylsilsesquioxane, indicating that the polyphenylsilsesquioxane has ordered ladder like structures rather than the branched ones. The relationship between molecular weight and the time of polycondensation was also discussed.
基金The project is supported by National Natural Science Foundation of China
文摘It was found for the first time that the compounds with only one functional group, such as pyridine, can show the promotion effect for the electrochemical reaction of cytochrome C at gold electrodes.
基金Province natural science fund in Guangdong subsidizes item(05300167)
文摘This paper studies mainly how to make use of Multi- Agent technology to solve the complex problems which are caused by unsuitable coordination between protection and untimely action and protection fault activity in large power system, and realizes timely the coordination among protections effectively in when losing some or all information. Thus it overcomes the difficult of solving single or shore range information, enhances correspond and coordination among the intelligent protect Agent, raises the stable and reliable property, and promotes the process of power network for large area.
文摘Background： It is still a challenge for the cardiac surgeons to achieve adequate revascularization for diffused coronary artery disease （CAD）. Coronary endarterectomy （CE） offers an alternative choice of coronary artery reconstruction and revascularization. In this study, short-term result of CE combined with coronary artery bypass graft （CABG） was discussed in the treatment for the diffused CAD. Methods： From January 2012 to April 2014, 221 cases of CABG were performed by the same surgeon in our unit. Among these cases, 38 cases of CE ＋ CABG were pertbrmed, which was about 17.2% （38/221） of the cohort. All these patients were divided into two groups： CE ＋ CABG group （Group A） and CABG alone group and postoperative complications and in-hospital mortality were Chi-square test and Student＇s t-test respectively. （Group B）. All clinical data were compared between the two groups, analyzed. The categorical and continuous variables were analyzed by Results： Diabetes mellitus, hypertension, hyperlipidemia, and peripheral vascular disease were more common in group A. In this cohort, a total of 50 vessels were endarterectomized. Among them, CE was perfbrmed on left anterior descending artery in 11 cases, on right coronary artery in 29 cases, on diagonal artery in 3 cases, on intermediate artery in 2 cases, on obtuse marginal artery in 5 cases. There was no hospital mortality in both groups. The intro-aortic balloon pump was required in 3 cases in Group A （3/38）, which was more often than that in Group B （3/183）. At the time of follow-up, coronary computed tomography angiogram showed all the grafts with CE were patent （50/50）. There is no cardio-related mortality in both groups. All these patients were free from coronary re-intervention. Conclusions： Coronary endarterectomy ＋ CABG can oilier satisfactory result for patients with diffused CAD in a short-term after the operation.
基金This study was supported by grants from the National Key Technology R＆D Program （No. 2015BAI13B06） and the National Natural Science Foundation of China （No. 21507003）.
文摘To the Editor： Endometriosis is a common gynecologic condition that affects approximately 10% of females of reproductive age. It is a chronic inflammatory disease that is defined by the presence of endometrial-like tissue outside the uterine cavity. Endometriosis commonly occurs in the peritoneum, ovaries, and rectovaginal septum, but may also be found in other abdominal or extra-abdominal sites.
