Plant development is a process from germination of seed to vegetative growth, flower initiation and development, fertilization and finally to the next generation seed formation. A lot of achievements have been obtai...Plant development is a process from germination of seed to vegetative growth, flower initiation and development, fertilization and finally to the next generation seed formation. A lot of achievements have been obtained in plant developmental biology in China. Since the 1990's, those young generation scientists returned to China from abroad to use molecular and genetic techniques to study morphological, physiological and biochemical process of plant development. The present paper reviews the progress in some research area of plant developmental biology in the past decades and also prospects the chance and future of plant developmental studies, due to the recent advances of plant genome sequencing and functional genomics in China under the international research background.展开更多
A new two-step framework is proposed for image segmentation. In the first step, the gray-value distribution of the given image is reshaped to have larger inter-class variance and less intra-class variance. In the sec-...A new two-step framework is proposed for image segmentation. In the first step, the gray-value distribution of the given image is reshaped to have larger inter-class variance and less intra-class variance. In the sec- ond step, the discriminant-based methods or clustering-based methods are performed on the reformed distribution. It is focused on the typical clustering methods-Gaussian mixture model (GMM) and its variant to demonstrate the feasibility of the framework. Due to the independence of the first step in its second step, it can be integrated into the pixel-based and the histogram-based methods to improve their segmentation quality. The experiments on artificial and real images show that the framework can achieve effective and robust segmentation results.展开更多
To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is dev...To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is developed by using the transfer matrix method of multibody system(MS-TMM), the transfer matrix of non-u- niform beam is derived, and the natural frequencies are computed. Compared with the numerical assembly method (NAM), the results by MS-TMM have good agreement with the results by FEM, and are better than the results by NAM. When using the high precision method, the global dynamic equations of the complex multibody system are not needed and the orders of involved system matrices are decreased greatly. For the investigation on the re- verse problem of the physical parameter identification of multibody system, MS-TMM and the optimization tech- nology based on genetic algorithms(GAs) are combined and extended. The identification problem is exchanged for an optimization problem, and it is formulated as a global minimum solution of the objective function with respect to natural frequencies of multibody system. At last, the numerical example of non-uniform beam with attach- ments is discussed, and the identification results indicate the feasibility and the effectivity of the proposed aop- proach.展开更多
Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergo...Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time.展开更多
Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential(ECD) set.The existing prob...Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential(ECD) set.The existing problems and countermeasures of the different differential systems were discussed,and a research status quo on the molecular identification and detection of clubroot pathogen in crucifers were introduced.展开更多
In order to further understand the debismuthizing mechanism with calcium and magnesium, the influence of adding amount of calcium on the bismuth removal from lead was examined. A part of the debismuthizing dross sampl...In order to further understand the debismuthizing mechanism with calcium and magnesium, the influence of adding amount of calcium on the bismuth removal from lead was examined. A part of the debismuthizing dross samples were studied by electron probe microanalysis (EPMA). The results show that the calculated bismuthide governing debismuthizing process is Ca3Mg7Bi8, which may be a mixture of Ca3Bi2, CaBi, CaBi3 and Mg3Bi2. And the bismuthide formed during the debismuthizing process exists in two states: one is free bismuthide in the matrix of dross, and the other is symbiotic with Pb-Ca phase.展开更多
In order to achieve fine debismuthizing of lead bullion,the effects of temperature,adding amount of calcium and magnesium and antimony on the bismuth removal from lead bullion were investigated.The mechanism of debism...In order to achieve fine debismuthizing of lead bullion,the effects of temperature,adding amount of calcium and magnesium and antimony on the bismuth removal from lead bullion were investigated.The mechanism of debismuthizing was also discussed.The results show that when adding amounts of calcium and magnesium reach 0.112% and 0.395%,respectively,bismuth level of 0.001%(mass fraction) in the final lead is achieved at 330 ℃,without the need for antimony addition.Maintaining addition amount of magnesium at 0.155%,when calcium addition amount is less than 0.09%,the concentration of peritectic reaction point,the bismuth concentration can be easily decreased to 0.001% by the following antimony treatment.But the effect of antimony treatment on debismuthizing gets bad if the calcium addition exceeds 0.09%.展开更多
Variety identification is important for maize breeding, processing and trade. The computer vision technique has been widely applied to maize variety identification. In this paper, computer vision technique has been su...Variety identification is important for maize breeding, processing and trade. The computer vision technique has been widely applied to maize variety identification. In this paper, computer vision technique has been summarized from the following technical aspects including image acquisition, image processing, characteristic parameter extraction, pattern recognition and programming softwares. In addition, the existing problems during the application of this technique to maize variety identification have also been analyzed and its development tendency is forecasted.展开更多
Fertilization in flowering plants is completed through several recognitionevents, and the first of which is the recognition of pollen by pistil of female reproductivetissue. Self-incompatibility (SI) is an intraspecif...Fertilization in flowering plants is completed through several recognitionevents, and the first of which is the recognition of pollen by pistil of female reproductivetissue. Self-incompatibility (SI) is an intraspecific reproductive barrier to prevent selfferitilization and widely distributed in flowering plants. In many species, SI shows simplegenetics and is controlled by a single multi-allelic locus, called the S locus. In gametophyticSI (GSI) exemplified by the Solanaceae, Scrophulariaceae and Rosaceae, a class ofribonucleases, called S RNases, have been shown to mediate the stylar expression of SI butnot the pollen expression of SI. The latter appears to be determined by a gene differentfrom those encoding S RNases, often referred to as pollen S gene. The pollen S gene is thecrucial missing part in understanding the biochemical and molecular mechanisms of self andnon-self pollen recognition in flowering plants. Recent genetic analysis of mutationsaffecting the pollen expression of SI has suggested a possible model of how the pollen S geneinteracts with S RNases to achieve self and non-self pollen recognition. Furthermore, wewill present two approaches, S-locus directed transposon tagging and map-based cloning, forcloning the pollen S in Antirrhinum.展开更多
Anthracnose disease is one of the major economic constraints to chilli production worldwide, especially in tropical and subtropical regions. Accurate taxonomic information is necessary for effective disease control ma...Anthracnose disease is one of the major economic constraints to chilli production worldwide, especially in tropical and subtropical regions. Accurate taxonomic information is necessary for effective disease control management. In the Colletotrichum patho-system, different Colletotrichum species can be associated with anthracnose of the same host. Little information is known concerning the interactions of the species associated with the chilli anthracnose although several Colletotrichum species have been reported as causal agents of chilli anthracnose disease worldwide. The ambiguous taxonomic status of Colletotrichum species has resulted in inaccurate identification which may cause practical problems in plant breeding and disease management. Although the management and control of anthracnose disease are still being extensively researched, commercial cultivars of Capsicum annuum that are resistant to the pathogens that cause chilli anthracnose have not yet been developed. This paper reviews the causal agents of chilli anthracnose, the disease cycle, conventional methods in identification of the pathogen and molecular approaches that have been used for the identification of Colletotrichum species. Pathogenetic variation and population structure of the causal agents of chilli anthracnose along with the current taxonomic status of Colletotrichum species are discussed. Future developments leading to the disease management strategies are suggested.展开更多
Edge detection is an image processing technique for finding the boundaries of objects within images. It is typically used to interpret gravity and magnetic data, and find the horizontal boundaries of geological bodies...Edge detection is an image processing technique for finding the boundaries of objects within images. It is typically used to interpret gravity and magnetic data, and find the horizontal boundaries of geological bodies. Large deviations between model and true edges are common because of the interference of depth and errors in computing the derivatives; thus, edge detection methods cannot provide information about the depth of the source. To simultaneously obtain the horizontal extent and depth of geophysical anomalies, we use normalized edge detection filters, which normalize the edge detection function at different depths, and the maxima that correspond to the location of the source. The errors between model and actual edges are minimized as the depth of the source decreases and the normalized edge detection method recognizes the extent of the source based on the maxima, allowing for reliable model results. We demonstrate the applicability of the normalized edge detection filters in defining the horizontal extent and depth using synthetic and actual aeromagnetic data.展开更多
The striking gender disparity observed in the incidence of hepatocellutar carcinoma (HCC) suggests an important role of sex hormones in HCC pathogenesis. Though the studies began as early as in 1980s, the precise ro...The striking gender disparity observed in the incidence of hepatocellutar carcinoma (HCC) suggests an important role of sex hormones in HCC pathogenesis. Though the studies began as early as in 1980s, the precise role of sex hormones and the significance of their receptors in HCC still remain poorly understood and perhaps contribute to current controversies about the potential use of hormonal therapy in HCC. A comprehensive review of the existing literature revealed several shortcomings associated with the studies on estrogen receptor (ER) and androgen receptor (AR) in normal liver and HCC. These shortcomings include the use of less sensitive receptor ligand binding assays and immunohistochemistry studies for ERα alone until 1996 when ERβ isoform was identified. The animal models of HCC utilized for studies were primarily based on chemical-induced hepatocarcinogenesis with less similarity to virus-induced HCC pathogenesis. However, recent in vitro studies in hepatoma cells provide newer insights for hormonal regulation of key cellular processes including interaction of ER and AR with viral proteins. In light of the above facts, there is an urgent need for a detailed investigation of sex hormones and their receptors in normal liver and HCC. In this review, we systematically present the information currently available on androgens, estrogens and their receptors in normal liver and HCC obtained from in vitro, in vivo experimental models and clinical studies. This information will direct future basic and clinical research to bridge the gap in knowledge to explore the therapeutic potential of hormonal therapy in HCC.展开更多
The international standard ISO 10303, called STEP, has been used to deal with problems in the ex-change of product models and the associated data between different computer-aided systems. A platform based on STEP for ...The international standard ISO 10303, called STEP, has been used to deal with problems in the ex-change of product models and the associated data between different computer-aided systems. A platform based on STEP for managing product information is presented. This platform includes three components: a product geometry information model, a product feature model and a product visualization model. An information extracting pattern, in which information is extracted from low level elements to high level ones, is adopted in establishing the product geometry information model. Relative elements lists are created based on the extracted product information. With the traversing of these lists, feature extraction methods are proposed, which take advantage of boundary information in product model and avoid the determination of concavity and convexity of curves. Information correlating to fea-tures is stored in a structure named as feature block and the product visualization model is founded from it. The feature block is used in the platform for information communication and synchronous update among the three com-ponents.展开更多
Functional dyspepsia is a common clinical condition characterised by chronic or recurrent upper abdominal pain or discomfort commonly associated with a variety of associated gastrointestinal symptoms and a normal endo...Functional dyspepsia is a common clinical condition characterised by chronic or recurrent upper abdominal pain or discomfort commonly associated with a variety of associated gastrointestinal symptoms and a normal endoscopy. To standardise research-based approaches, an initial categorisation of into sub groups was agreed to, based on clusters of symptoms. However the early expectation that these subgroups would be associated with distinct pathophysiologies amenable to specific therapy has not been realised. A classification based on the most troublesome symptom has been suggested but the utility of this is also unclear. More recent data suggest that some of the pathophysiologic dysfunctions may be associated with specific symptoms and so provide a better tool for grouping patients. But this approach remains incomplete as current insights into the pathogenesis are still too limited for this to be satisfactory. In conclusion, no classification provides for an adequate treatment-based approach to the syndrome of functional dyspepsia. As a consequence treatment remains largely empiric.展开更多
According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template_based matching model,...According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template_based matching model,prototype_based matching model and feature_based matching model are built and discussed separately.In addition,the influence of object background information and visual focus point to the result of pattern recognition is also discussed with the example of recognition for fuzzy letters and figures展开更多
Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results ...Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results The automatic identification of every parking place in the parking plot was realized. The automatic measuring of parked vehicle count and parking lot utilization was completed. Conclusion It can complete the real time recognition, and has some practicabilities.展开更多
A novel Bacterial Foraging Algorithm (BFA) based neural network is presented for image compression. To improve the quality of the decompressed images, the concepts of reproduction, elimination and dispersal in BFA are...A novel Bacterial Foraging Algorithm (BFA) based neural network is presented for image compression. To improve the quality of the decompressed images, the concepts of reproduction, elimination and dispersal in BFA are firstly introduced into neural network in the proposed algorithm. Extensive experiments are conducted on standard testing images and the results show that the pro- posed method can improve the quality of the reconstructed images significantly.展开更多
Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb...Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb,lambda-cyhalothrin,and simeconazole,were studied on cellulose tris-(3,5-dimethylphenyl-carbamate)-coated chiral stationary phase(CDMPC-CSP) using high-performance liquid chromatography under normal phase condition.The effects of chromatographic conditions,such as the mobile phase composition including the concentration and type of alcohol modifiers in hexane,flow rate and column temperature,on enantiomer separation were examined.The thermodynamical mechanism of enantioseparation and chiral recognition mechanism were discussed.Better separation were achieved using 20% n-propanol for indoxacarb,2% iso-butanol for lambda-cyhalothrin,and 20% iso-propanol for simeconazole as modifiers in hexane at 25℃ with the selectivity factor(a) of 1.69,1.82 and 1.70,respectively.The resolution factor(Rs) decreased as the flow rate increased from 0.4 to 1.1 ml·min-1.The retention factor(k') and selectivity factor for the enantiomers of analytes decreased as temperature increased.The lna-1/T plots for racemic chiral pesticides were linear in the range of 15-35℃ in hexane/iso-propanol and the chiral separation was controlled by enthalpy.Hydrogen bonding,π-π and dipole-dipole interactions between enantiomers and CDMPC-CSP play an important role in chiral identification,and the fitting of the asymmetric portion of solutes in a chiral cavity or channel of the CSP is also important.展开更多
Heterotopic pancreas is defined as pancreatic tissue found outside the usual anatomical location of the pancreas. It is often an incidental finding and can be found at different sites in the gastrointestinal tract. It...Heterotopic pancreas is defined as pancreatic tissue found outside the usual anatomical location of the pancreas. It is often an incidental finding and can be found at different sites in the gastrointestinal tract. It may become clinically evident when complicated by pathological changes such as inflammation, bleeding, obstruction, and malignant transformation. In this report, a 60-year-old man with carcinoid syndrome caused by heterotopic pancreatic tissue in the duodenum is described, along with a 62-year-old man with abdominal pain caused by heterotopic pancreatic tissue in the gastric antrum. The difficulty of making an accurate diagnosis is highlighted. The patients remain healthy and symptom-free after follow-up of 1 year. Frozen sections may help in deciding the extent of resection intraoperatively. Although heterotopic pancreas is rare, it should be considered in the differential diagnosis of gastrointestinal stromal tumor.展开更多
文摘Plant development is a process from germination of seed to vegetative growth, flower initiation and development, fertilization and finally to the next generation seed formation. A lot of achievements have been obtained in plant developmental biology in China. Since the 1990's, those young generation scientists returned to China from abroad to use molecular and genetic techniques to study morphological, physiological and biochemical process of plant development. The present paper reviews the progress in some research area of plant developmental biology in the past decades and also prospects the chance and future of plant developmental studies, due to the recent advances of plant genome sequencing and functional genomics in China under the international research background.
基金Supported by the National Natural Science Foundation of China(60505004,60773061)~~
文摘A new two-step framework is proposed for image segmentation. In the first step, the gray-value distribution of the given image is reshaped to have larger inter-class variance and less intra-class variance. In the sec- ond step, the discriminant-based methods or clustering-based methods are performed on the reformed distribution. It is focused on the typical clustering methods-Gaussian mixture model (GMM) and its variant to demonstrate the feasibility of the framework. Due to the independence of the first step in its second step, it can be integrated into the pixel-based and the histogram-based methods to improve their segmentation quality. The experiments on artificial and real images show that the framework can achieve effective and robust segmentation results.
基金Supported by the National Natural Science Foundation of China(10902051)the Natural Science Foundation of Jiangsu Province(BK2008046)~~
文摘To analyze a multibody system composed of non-uniform beam and spring-mass subsystems, the model discretization is carried on by utilizing the finite element method(FEM), the dynamic model of non-uniform beam is developed by using the transfer matrix method of multibody system(MS-TMM), the transfer matrix of non-u- niform beam is derived, and the natural frequencies are computed. Compared with the numerical assembly method (NAM), the results by MS-TMM have good agreement with the results by FEM, and are better than the results by NAM. When using the high precision method, the global dynamic equations of the complex multibody system are not needed and the orders of involved system matrices are decreased greatly. For the investigation on the re- verse problem of the physical parameter identification of multibody system, MS-TMM and the optimization tech- nology based on genetic algorithms(GAs) are combined and extended. The identification problem is exchanged for an optimization problem, and it is formulated as a global minimum solution of the objective function with respect to natural frequencies of multibody system. At last, the numerical example of non-uniform beam with attach- ments is discussed, and the identification results indicate the feasibility and the effectivity of the proposed aop- proach.
基金The present work was supported by Foundation of State Key Basic Research and Development Project (G1998051100)
文摘Two compounds were isolated from ethyl acetate extract of the fermentation of fungus 07-11, which obtained from the soil of Yunnan Province. They were identified as N-(4-hydroxy-2-methoxyphenyl) acetamide (1) and ergosta-7,22-diene-3,6-dione (2) respectively on the basis of spectral analyses and physical and chemical identifications. Compound 1 was a new natural product. Compound 2 was firstly isolated from its genus. Spectral data of 1 and complete 1H NMR data of 2 were reported for the first time.
基金Supported by the National Science and Technology Program of the Ministry of Science and Technology of China(2010BAD01B04)Research Fund of Department of Science and Technology of Sichuan Province(2008NG0003)the Genetic Engineering Fund of Department of Finance of Sichuan Province(2011JYGC06)~~
文摘Research progress was reviewed on the differential systems for physiologic races of Plasmodiophora brassicae Woron,including Williams,differential system and European clubroot differential(ECD) set.The existing problems and countermeasures of the different differential systems were discussed,and a research status quo on the molecular identification and detection of clubroot pathogen in crucifers were introduced.
文摘In order to further understand the debismuthizing mechanism with calcium and magnesium, the influence of adding amount of calcium on the bismuth removal from lead was examined. A part of the debismuthizing dross samples were studied by electron probe microanalysis (EPMA). The results show that the calculated bismuthide governing debismuthizing process is Ca3Mg7Bi8, which may be a mixture of Ca3Bi2, CaBi, CaBi3 and Mg3Bi2. And the bismuthide formed during the debismuthizing process exists in two states: one is free bismuthide in the matrix of dross, and the other is symbiotic with Pb-Ca phase.
文摘In order to achieve fine debismuthizing of lead bullion,the effects of temperature,adding amount of calcium and magnesium and antimony on the bismuth removal from lead bullion were investigated.The mechanism of debismuthizing was also discussed.The results show that when adding amounts of calcium and magnesium reach 0.112% and 0.395%,respectively,bismuth level of 0.001%(mass fraction) in the final lead is achieved at 330 ℃,without the need for antimony addition.Maintaining addition amount of magnesium at 0.155%,when calcium addition amount is less than 0.09%,the concentration of peritectic reaction point,the bismuth concentration can be easily decreased to 0.001% by the following antimony treatment.But the effect of antimony treatment on debismuthizing gets bad if the calcium addition exceeds 0.09%.
基金Special Fund for Science & Technology Research of Education Commission,Chongqing(KJ101302)~~
文摘Variety identification is important for maize breeding, processing and trade. The computer vision technique has been widely applied to maize variety identification. In this paper, computer vision technique has been summarized from the following technical aspects including image acquisition, image processing, characteristic parameter extraction, pattern recognition and programming softwares. In addition, the existing problems during the application of this technique to maize variety identification have also been analyzed and its development tendency is forecasted.
文摘Fertilization in flowering plants is completed through several recognitionevents, and the first of which is the recognition of pollen by pistil of female reproductivetissue. Self-incompatibility (SI) is an intraspecific reproductive barrier to prevent selfferitilization and widely distributed in flowering plants. In many species, SI shows simplegenetics and is controlled by a single multi-allelic locus, called the S locus. In gametophyticSI (GSI) exemplified by the Solanaceae, Scrophulariaceae and Rosaceae, a class ofribonucleases, called S RNases, have been shown to mediate the stylar expression of SI butnot the pollen expression of SI. The latter appears to be determined by a gene differentfrom those encoding S RNases, often referred to as pollen S gene. The pollen S gene is thecrucial missing part in understanding the biochemical and molecular mechanisms of self andnon-self pollen recognition in flowering plants. Recent genetic analysis of mutationsaffecting the pollen expression of SI has suggested a possible model of how the pollen S geneinteracts with S RNases to achieve self and non-self pollen recognition. Furthermore, wewill present two approaches, S-locus directed transposon tagging and map-based cloning, forcloning the pollen S in Antirrhinum.
文摘Anthracnose disease is one of the major economic constraints to chilli production worldwide, especially in tropical and subtropical regions. Accurate taxonomic information is necessary for effective disease control management. In the Colletotrichum patho-system, different Colletotrichum species can be associated with anthracnose of the same host. Little information is known concerning the interactions of the species associated with the chilli anthracnose although several Colletotrichum species have been reported as causal agents of chilli anthracnose disease worldwide. The ambiguous taxonomic status of Colletotrichum species has resulted in inaccurate identification which may cause practical problems in plant breeding and disease management. Although the management and control of anthracnose disease are still being extensively researched, commercial cultivars of Capsicum annuum that are resistant to the pathogens that cause chilli anthracnose have not yet been developed. This paper reviews the causal agents of chilli anthracnose, the disease cycle, conventional methods in identification of the pathogen and molecular approaches that have been used for the identification of Colletotrichum species. Pathogenetic variation and population structure of the causal agents of chilli anthracnose along with the current taxonomic status of Colletotrichum species are discussed. Future developments leading to the disease management strategies are suggested.
基金supported by the China Postdoctoral Science Foundation (No.2014M551188)the Deep Exploration in China Sinoprobe-09-01 (No.201011078)
文摘Edge detection is an image processing technique for finding the boundaries of objects within images. It is typically used to interpret gravity and magnetic data, and find the horizontal boundaries of geological bodies. Large deviations between model and true edges are common because of the interference of depth and errors in computing the derivatives; thus, edge detection methods cannot provide information about the depth of the source. To simultaneously obtain the horizontal extent and depth of geophysical anomalies, we use normalized edge detection filters, which normalize the edge detection function at different depths, and the maxima that correspond to the location of the source. The errors between model and actual edges are minimized as the depth of the source decreases and the normalized edge detection method recognizes the extent of the source based on the maxima, allowing for reliable model results. We demonstrate the applicability of the normalized edge detection filters in defining the horizontal extent and depth using synthetic and actual aeromagnetic data.
文摘The striking gender disparity observed in the incidence of hepatocellutar carcinoma (HCC) suggests an important role of sex hormones in HCC pathogenesis. Though the studies began as early as in 1980s, the precise role of sex hormones and the significance of their receptors in HCC still remain poorly understood and perhaps contribute to current controversies about the potential use of hormonal therapy in HCC. A comprehensive review of the existing literature revealed several shortcomings associated with the studies on estrogen receptor (ER) and androgen receptor (AR) in normal liver and HCC. These shortcomings include the use of less sensitive receptor ligand binding assays and immunohistochemistry studies for ERα alone until 1996 when ERβ isoform was identified. The animal models of HCC utilized for studies were primarily based on chemical-induced hepatocarcinogenesis with less similarity to virus-induced HCC pathogenesis. However, recent in vitro studies in hepatoma cells provide newer insights for hormonal regulation of key cellular processes including interaction of ER and AR with viral proteins. In light of the above facts, there is an urgent need for a detailed investigation of sex hormones and their receptors in normal liver and HCC. In this review, we systematically present the information currently available on androgens, estrogens and their receptors in normal liver and HCC obtained from in vitro, in vivo experimental models and clinical studies. This information will direct future basic and clinical research to bridge the gap in knowledge to explore the therapeutic potential of hormonal therapy in HCC.
基金Supported by National Natural Science Foundation of China (No.50475117)Tianjin Municipal Science and Technology Commission (No.05YFJZJC01800)Research Fund for the Doctoral Program of Higher Education of China (No.20060056016).
文摘The international standard ISO 10303, called STEP, has been used to deal with problems in the ex-change of product models and the associated data between different computer-aided systems. A platform based on STEP for managing product information is presented. This platform includes three components: a product geometry information model, a product feature model and a product visualization model. An information extracting pattern, in which information is extracted from low level elements to high level ones, is adopted in establishing the product geometry information model. Relative elements lists are created based on the extracted product information. With the traversing of these lists, feature extraction methods are proposed, which take advantage of boundary information in product model and avoid the determination of concavity and convexity of curves. Information correlating to fea-tures is stored in a structure named as feature block and the product visualization model is founded from it. The feature block is used in the platform for information communication and synchronous update among the three com-ponents.
文摘Functional dyspepsia is a common clinical condition characterised by chronic or recurrent upper abdominal pain or discomfort commonly associated with a variety of associated gastrointestinal symptoms and a normal endoscopy. To standardise research-based approaches, an initial categorisation of into sub groups was agreed to, based on clusters of symptoms. However the early expectation that these subgroups would be associated with distinct pathophysiologies amenable to specific therapy has not been realised. A classification based on the most troublesome symptom has been suggested but the utility of this is also unclear. More recent data suggest that some of the pathophysiologic dysfunctions may be associated with specific symptoms and so provide a better tool for grouping patients. But this approach remains incomplete as current insights into the pathogenesis are still too limited for this to be satisfactory. In conclusion, no classification provides for an adequate treatment-based approach to the syndrome of functional dyspepsia. As a consequence treatment remains largely empiric.
文摘According to the fundamental theory of visual cognition mechanism and cognitive psychology,the visual pattern recognition model is introduced briefly.Three pattern recognition models,i.e.template_based matching model,prototype_based matching model and feature_based matching model are built and discussed separately.In addition,the influence of object background information and visual focus point to the result of pattern recognition is also discussed with the example of recognition for fuzzy letters and figures
文摘Aim To study the parking management in the condition of vehicles' increasing. Methods The methods of pattern recognition and image processing were used to analyze the eigenvalues of parking lot images. Results The automatic identification of every parking place in the parking plot was realized. The automatic measuring of parked vehicle count and parking lot utilization was completed. Conclusion It can complete the real time recognition, and has some practicabilities.
基金Supported by the National Natural Science Foundation of China (No.60572100)by the Royal Society (U.K.) International Joint Projects 2006/R3-Cost Share with NSFC (No.60711130233)
文摘A novel Bacterial Foraging Algorithm (BFA) based neural network is presented for image compression. To improve the quality of the decompressed images, the concepts of reproduction, elimination and dispersal in BFA are firstly introduced into neural network in the proposed algorithm. Extensive experiments are conducted on standard testing images and the results show that the pro- posed method can improve the quality of the reconstructed images significantly.
基金Supported by China Postdoctoral Science Fund (20090461007)Postdoctoral Research Funding Special Plans of Hunan(2010RC4025)Graduate Innovation Research Project of Hunan (CX2010B295)
文摘Enantiomer separation is one of the most important prerequisites for the investigation of environmental enantioselective behavior for chiral pesticides.The enantiomeric separation of three chiral pesticides,indoxacarb,lambda-cyhalothrin,and simeconazole,were studied on cellulose tris-(3,5-dimethylphenyl-carbamate)-coated chiral stationary phase(CDMPC-CSP) using high-performance liquid chromatography under normal phase condition.The effects of chromatographic conditions,such as the mobile phase composition including the concentration and type of alcohol modifiers in hexane,flow rate and column temperature,on enantiomer separation were examined.The thermodynamical mechanism of enantioseparation and chiral recognition mechanism were discussed.Better separation were achieved using 20% n-propanol for indoxacarb,2% iso-butanol for lambda-cyhalothrin,and 20% iso-propanol for simeconazole as modifiers in hexane at 25℃ with the selectivity factor(a) of 1.69,1.82 and 1.70,respectively.The resolution factor(Rs) decreased as the flow rate increased from 0.4 to 1.1 ml·min-1.The retention factor(k') and selectivity factor for the enantiomers of analytes decreased as temperature increased.The lna-1/T plots for racemic chiral pesticides were linear in the range of 15-35℃ in hexane/iso-propanol and the chiral separation was controlled by enthalpy.Hydrogen bonding,π-π and dipole-dipole interactions between enantiomers and CDMPC-CSP play an important role in chiral identification,and the fitting of the asymmetric portion of solutes in a chiral cavity or channel of the CSP is also important.
文摘Heterotopic pancreas is defined as pancreatic tissue found outside the usual anatomical location of the pancreas. It is often an incidental finding and can be found at different sites in the gastrointestinal tract. It may become clinically evident when complicated by pathological changes such as inflammation, bleeding, obstruction, and malignant transformation. In this report, a 60-year-old man with carcinoid syndrome caused by heterotopic pancreatic tissue in the duodenum is described, along with a 62-year-old man with abdominal pain caused by heterotopic pancreatic tissue in the gastric antrum. The difficulty of making an accurate diagnosis is highlighted. The patients remain healthy and symptom-free after follow-up of 1 year. Frozen sections may help in deciding the extent of resection intraoperatively. Although heterotopic pancreas is rare, it should be considered in the differential diagnosis of gastrointestinal stromal tumor.