Automatic splicing of interrupted yarns in ring spinning has always been a problem in the industry.Factors such as low yarn strengths and environmental influence on yarn tensions make it difficult to control the yarn ...Automatic splicing of interrupted yarns in ring spinning has always been a problem in the industry.Factors such as low yarn strengths and environmental influence on yarn tensions make it difficult to control the yarn tension during the robotic splicing process.The purpose of this research is to design active disturbance rejection control(ADRC)for a third-order nonlinear tension system subject to external disturbances.Firstly,a third-order extended state observer(ESO)is designed to achieve the suppression and the compensation of the internal modeling error and the external disturbances of the system.Secondly,the adaptive gain error feedback control and the filtering process are designed to reduce the influence of sensor noise on the disturbance observation.Finally,the tension control during the splicing process is simulated and experimented,and the experiments show that the method has good robustness in the tension tracking task under a dynamic environment,which verifies the effectiveness of the method.展开更多
In order to evaluate the phylogenetic position and validity of Rana altaica,we investigated the phylogeny of brown frogs in Eurasia by Bayesian Inference and Maximum Parsimony analyses of a fragment from the mitochond...In order to evaluate the phylogenetic position and validity of Rana altaica,we investigated the phylogeny of brown frogs in Eurasia by Bayesian Inference and Maximum Parsimony analyses of a fragment from the mitochondrial DNA gene Cytochrome b.Both analyses resolved R.altaica as nesting deeply within R.arvalis.Most samples of the nominal R.altaica from the Altai region and specimens from Central Siberia shared a haplotype with R.arvalis based on the network analysis.The matrilineal relationships suggested that R.altaica should be considered as a junior synonym of R.arvalis.Furthermore,our study suggested that the species group division of Chinese brown frogs should be re-evaluated within a phylogenetic context.展开更多
Reduced Q-matrix (Qr matrix) plays an important role in the rule space model (RSM) and the attribute hierarchy method (AHM). Based on the attribute hierarchy, a valid/invalid item is defined. The judgment method...Reduced Q-matrix (Qr matrix) plays an important role in the rule space model (RSM) and the attribute hierarchy method (AHM). Based on the attribute hierarchy, a valid/invalid item is defined. The judgment method of the valid/invalid item is developed on the relation between reachability matrix and valid items. And valid items are explained from the perspective of graph theory. An incremental augment algorithm for constructing Qr matrix is proposed based on the idea of incremental forward regression, and its validity is theoretically considered. Results of empirical tests are given in order to compare the performance of the incremental augment algo-rithm and the Tatsuoka algorithm upon the running time. Empirical evidence shows that the algorithm outper-forms the Tatsuoka algorithm, and the analysis of the two algorithms also show linear growth with respect to the number of valid items. Mathematical models with 10 attributes are built for the two algorithms by the linear regression analysis.展开更多
In order to overcome the wide-range load tracking and unknown disturbance issues of an ultra-supercritical boiler- turbine unit, a fuzzy disturbance rejection predictive control approach is proposed using the techniq...In order to overcome the wide-range load tracking and unknown disturbance issues of an ultra-supercritical boiler- turbine unit, a fuzzy disturbance rejection predictive control approach is proposed using the techniques of fuzzy scheduling, model predictive control and extended state observer. Local state-space models are established on the basis of nonlinearity analysis and subspace identification. To eiJiance thedisturbance rejection capability of the controller, a extended state observer is employed to estimate unnown disturbances and model mismatches. The disturbance estimation ennaced local predictive controllers ae subsequently devised based on the local models, the performance of which is further strengthened by incorporating the fuzzy scheduling technique. The simulation results verify the merits of the proposed strategy in achieving satisfactory wide-range load tracking ad disturbance rejection performance.展开更多
The method of commensurability was used by the authors to predict the great earthquake of magnitude 7.5 that occurred on March 31,2002 in Taiwan 70km away from Hualian. Analyzing the earthquakes of magnitude≥7.0 whic...The method of commensurability was used by the authors to predict the great earthquake of magnitude 7.5 that occurred on March 31,2002 in Taiwan 70km away from Hualian. Analyzing the earthquakes of magnitude≥7.0 which occurred in the Hualian area of Taiwan within the 20th century, the authors discovered that the occurrences of the earthquakes are commensurable. The earthquakes of magnitude 7.6 which occurred in Hualian of Taiwan, on September 20th, 1999 and of magnitude 7.5 which occurred 70 km away from Hualian, on March 31th, 2002 appeared at the commensurable point of K=2 and the period times the golden section, respectively. An extended discussion is carried out on the method of commensurability and its implied physical significance, especially on the contribution of the commensurable periodic extension made by Prof. Weng Wenbo.展开更多
The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative...The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative effects on the structure of our wintering populations. For its effective protection, it is important to conduct an intensive study on the genetic structure of this population. A total of 221 faecal samples, nine feather samples and four muscle samples of Hooded Cranes from four wintering populations, i.e., from Caizi Lake and Shengjin Lake in Anhui, Poyang Lake in Jiangxi and Chongming Dongtan in Shanghai, were collected for this study. Full-length 1103–1104 bp mtDNA D-loop sequences from 72 samples were amplified using PCR. Based on our amplified D-loop sequences and the sequences of two individual birds obtained from GenBank (AB017625 and AB023813), we analyzed the genetic structure of these four wintering Hooded Crane populations. Twenty six variable sites were found among 72 target sequences in the four wintering populations and 23 haplotypes were defined. Genetic diversity analyses showed that the haplotype diversity of Hooded Cranes was 0.823 ± 0.042 with a nucleotide diversity of 0.00157 ± 0.00021. The FST values of the four populations show that there is no significant genetic differentiation among the populations of Hooded Cranes wintering in the middle and lower reaches of the Yangtze River. Tajima’s D and Fu’s tests suggest that the Hooded Crane populations may have experienced population expansion in their evolutionary history.展开更多
The close relationship between the structure,evolution,and resources environment of the South China Sea is a current research focus and also a focal point of our study.In this paper,we use regional seismic sections to...The close relationship between the structure,evolution,and resources environment of the South China Sea is a current research focus and also a focal point of our study.In this paper,we use regional seismic sections to analyze the relationship between seismic facies and the structure and tectonic evolution of the northeastern South China Sea and propose new points about the structure and the direction of block(land mass) motion.First,the tectonic features are clear and can be divided into five different structural units which are both linked and independent of each other.Second,it doesn't matter if the South China Sea basin pattern is extensional,weakly compressive,or strongly compressive,the regional tectonic stress field is unified.For the first time we find that two shallow subduction zones are recognized in the seismic profiles.All the tectonic blocks have accordion-fold-style structures,converging in the east,and the South China Sea exhibits different stages of basin development:growth, maturity,end,and termination.The block subduction and regional block dip directions are all aligned with the regional stress field.展开更多
To evaluate the effect of the positive-indefinite matrix on the diffusion tensor-derived parameters, a modified algorithm is proposed for calculating these parameters. Magnetic resonance (MR) diffusion tensor images...To evaluate the effect of the positive-indefinite matrix on the diffusion tensor-derived parameters, a modified algorithm is proposed for calculating these parameters. Magnetic resonance (MR) diffusion tensor images of five healthy volunteers are collected. The diffusion sensitive gradient magnetic fields are applied along 25 directions and the diffusion weighting value is 1 000 s/mm^2. Many positive-indefinite diffusion tensors can be found in the white matter area, such as the genu and the splenium of corpus callosum. Due to the positive-indefinite matrix, the mean diffusivity (MD) and the fractional anisotropy (FA) are under-estimated and over-estimated by using the conventional algorithm. Thus, the conventional algorithm is modified by using the absolute values of all eigenvalues. Results show that both the robustness and the reliability for deriving these parameters are improved by the modified algorithm.展开更多
A ring R is said to be satisfying P-stable range provided that whenever aR + bR = R, there exists y ∈ P(R) such that a + by is a unit of R, where P(R) is the subset of R which satisfies the property that up, pu...A ring R is said to be satisfying P-stable range provided that whenever aR + bR = R, there exists y ∈ P(R) such that a + by is a unit of R, where P(R) is the subset of R which satisfies the property that up, pu∈ P(R) for every unit u of R and p ∈P(R). By studying this ring, some known results of rings satisfying unit-1 stable range, ( S, 2) -stable range, weakly unit 1- stable range and stable range one are unified. An element of a ring is said to be UR if it is the sum of a unit and a regular dement and a ring is said to be satisfying UR-stable range if R has P-stable range and P(R) is the set of all UR-elements of R, Some properties of this ring are studied and it is proven that if R satisfies UR-stahle range then so does any n × n matrix ring over R.展开更多
The exchange rings without unity, first introduced by Ara, are further investigated. Some new characterizations and properties of exchange general rings are given. For example, a general ring I is exchange if and only...The exchange rings without unity, first introduced by Ara, are further investigated. Some new characterizations and properties of exchange general rings are given. For example, a general ring I is exchange if and only if for any left ideal L of I and a^-= a^-2 ∈I/L, there exists w ∈ r. ureg(I) such that w^- = a^-; E(R, I) ( the ideal extension of a ring R by its ideal I) is an exchange ring if and only if R and I are both exchange. Furthermore, it is presented that if I is a two-sided ideal of a unital ring R and I is an exchange general ring, then every central element of I is a clean element in 1.展开更多
In this paper, we shall define a new concept, P map. Therefore the question which arises in will be answered satisfactorily, i.e. a frame map f: K→L from a T 2 frame K to a T 2 frame L c...In this paper, we shall define a new concept, P map. Therefore the question which arises in will be answered satisfactorily, i.e. a frame map f: K→L from a T 2 frame K to a T 2 frame L can be uniquely extended to a frame map τf:τK→τL if and only if f is a P map.展开更多
A series of new 2 (alkylthio) 5,7 dimethyl 1,2,4 triazolopyrimidines and 3 (alkylthio) 5,7 dimethyl 1,2,4 triazolopyrimidines have been synthesized. These derivatives were evaluated for inhibitory effects on...A series of new 2 (alkylthio) 5,7 dimethyl 1,2,4 triazolopyrimidines and 3 (alkylthio) 5,7 dimethyl 1,2,4 triazolopyrimidines have been synthesized. These derivatives were evaluated for inhibitory effects on 85 7 mmol·L 1 K + and 10 4 mmol·L -1 NE (nor epinephrine) induced contraction of rat aorta strips.展开更多
Objective:To investigate the effect of Fufang Danshen pill on bone marrow stem mobilization during myocardial scathe. Methods:Rat models with expansionary myocardial disease were established by Pituitrin and Furazol...Objective:To investigate the effect of Fufang Danshen pill on bone marrow stem mobilization during myocardial scathe. Methods:Rat models with expansionary myocardial disease were established by Pituitrin and Furazolidone. Experimental rats were divided into the contrast group, the myocardial scathe group (MS group), the myocardial scathe and Fufang Dansben pill group ( MS + FD group) and the myocardial scathe and fluvastatin group ( MS + FT group). The ratio of CD34^+ cells was examined at the 1^st, 3^nl and 6^th weekend. Index of heart structure and function including LVESD, LVEDD. LYEF, LVEDP and dp/dtmax were evaluated at the 6^th weekend. The HW/BW index was calculated. Results:In the MS group, the index of HW/BW, LVESD, LVEDD and LVEDP were obviously increased (P 〈 0.01 ) and index of dp/ dtmax and LVEF were obviously decreased (P 〈 0.05 ). The ratio of CD34^+ cells was significantly improved at the 1^at weekend and then reduced slowly with no difference from that of the contrast group at the 6th weekend. Compared the MS + FD group and the MS + FT group with the MS group, the index of HW/BW, LYESD, LYEDD and LYEDP of were signifi cantly decreased ( P 〈 0.05 ) and index of dp/dtmax and LVEF were increased (P 〈 0.01 ). The ratio of CD34^+ cells was significantly higher at the 1^st, 3^nl and 6^th weekend, but had no statistic meaning at 3^nl and 6^th weekend (P 〉 0.05 ). Conclusion:Pituitrin and Furazolidone can be used to establish rat models with expansionary myocardial disease. There has bone marrow stem mobilization during the early period of myocardial scathe. Fufang Danshen pill has effect on improving bone marrow stem mobilization, lightening the expansionary degree of heart and protecting the heart function. The effect of Fufang Danshen pill is as same as that of fluvastatin.展开更多
AIM: TO introduce a new method: small endoscopic sphincterotomy (ES) combined with endoscopic papillary large balloon dilation (SES + EPLBD) to treat patients with large biliary stones.METHODS: Retrieval of la...AIM: TO introduce a new method: small endoscopic sphincterotomy (ES) combined with endoscopic papillary large balloon dilation (SES + EPLBD) to treat patients with large biliary stones.METHODS: Retrieval of large biliary stones was performed in 88 patients. Mean stone size was 14 ± 3 mm and mean number of stones was 2.5 ± 3.5. Firstly, ES with a small incision was performed. Next, endoscopic papillary dilation was performed with a large balloon to slowly match the size of the bile duct. Stones were then retrieved from the biliary duct with a balloon and a basket.RESULTS: Stone retrieval was successful in all cases except one cystic duct stone case without the need to crush large stones. Mean procedure time was 30 ± 5 min. Dilating the papillary orifice with a large balloon made it possible to remove large stones smoothly without crushing them. After dilation with the large balloon, there were some instances of oozing, but no perforations. One instance of post-procedural pancreatitis (1%) occurred. CONCLUSION: SES + EPLBD was effective for the retrieval of large biliary stones without the use of mechanical lithotripsy.展开更多
AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic ca...AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases. METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records. RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer. CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful followup since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high.展开更多
基金National Natural Science Foundation of China(No.52275478)Fundamental Research Funds for the Central Universities,China(No.2232024Y-01)DHU Distinguished Young Professor Program,China(No.LZB2023001)。
文摘Automatic splicing of interrupted yarns in ring spinning has always been a problem in the industry.Factors such as low yarn strengths and environmental influence on yarn tensions make it difficult to control the yarn tension during the robotic splicing process.The purpose of this research is to design active disturbance rejection control(ADRC)for a third-order nonlinear tension system subject to external disturbances.Firstly,a third-order extended state observer(ESO)is designed to achieve the suppression and the compensation of the internal modeling error and the external disturbances of the system.Secondly,the adaptive gain error feedback control and the filtering process are designed to reduce the influence of sensor noise on the disturbance observation.Finally,the tension control during the splicing process is simulated and experimented,and the experiments show that the method has good robustness in the tension tracking task under a dynamic environment,which verifies the effectiveness of the method.
基金The National Natural Science Foundation of China(30700065)the Program for Fostering Young Talents of Kunming Institute of Zoology,the Chinese Academy of Sciences(0706571141)~~
文摘In order to evaluate the phylogenetic position and validity of Rana altaica,we investigated the phylogeny of brown frogs in Eurasia by Bayesian Inference and Maximum Parsimony analyses of a fragment from the mitochondrial DNA gene Cytochrome b.Both analyses resolved R.altaica as nesting deeply within R.arvalis.Most samples of the nominal R.altaica from the Altai region and specimens from Central Siberia shared a haplotype with R.arvalis based on the network analysis.The matrilineal relationships suggested that R.altaica should be considered as a junior synonym of R.arvalis.Furthermore,our study suggested that the species group division of Chinese brown frogs should be re-evaluated within a phylogenetic context.
基金Supported by the National Natural Science Foundation of China (30860084,60673014,60263005)the Backbone Young Teachers Foundation of Fujian Normal University(2008100244)the Department of Education Foundation of Fujian Province (ZA09047)~~
文摘Reduced Q-matrix (Qr matrix) plays an important role in the rule space model (RSM) and the attribute hierarchy method (AHM). Based on the attribute hierarchy, a valid/invalid item is defined. The judgment method of the valid/invalid item is developed on the relation between reachability matrix and valid items. And valid items are explained from the perspective of graph theory. An incremental augment algorithm for constructing Qr matrix is proposed based on the idea of incremental forward regression, and its validity is theoretically considered. Results of empirical tests are given in order to compare the performance of the incremental augment algo-rithm and the Tatsuoka algorithm upon the running time. Empirical evidence shows that the algorithm outper-forms the Tatsuoka algorithm, and the analysis of the two algorithms also show linear growth with respect to the number of valid items. Mathematical models with 10 attributes are built for the two algorithms by the linear regression analysis.
基金The National Natural Science Foundation of China(No.51506029,51576041)the Natural Science Foundation of Jiangsu Province(No.BK20150631)China Postdoctoral Science Foundation
文摘In order to overcome the wide-range load tracking and unknown disturbance issues of an ultra-supercritical boiler- turbine unit, a fuzzy disturbance rejection predictive control approach is proposed using the techniques of fuzzy scheduling, model predictive control and extended state observer. Local state-space models are established on the basis of nonlinearity analysis and subspace identification. To eiJiance thedisturbance rejection capability of the controller, a extended state observer is employed to estimate unnown disturbances and model mismatches. The disturbance estimation ennaced local predictive controllers ae subsequently devised based on the local models, the performance of which is further strengthened by incorporating the fuzzy scheduling technique. The simulation results verify the merits of the proposed strategy in achieving satisfactory wide-range load tracking ad disturbance rejection performance.
基金This work was supported by the Nation’s Natural Science Found of China (No.10373017) and the Chinese Astronomical Committee Foundation.
文摘The method of commensurability was used by the authors to predict the great earthquake of magnitude 7.5 that occurred on March 31,2002 in Taiwan 70km away from Hualian. Analyzing the earthquakes of magnitude≥7.0 which occurred in the Hualian area of Taiwan within the 20th century, the authors discovered that the occurrences of the earthquakes are commensurable. The earthquakes of magnitude 7.6 which occurred in Hualian of Taiwan, on September 20th, 1999 and of magnitude 7.5 which occurred 70 km away from Hualian, on March 31th, 2002 appeared at the commensurable point of K=2 and the period times the golden section, respectively. An extended discussion is carried out on the method of commensurability and its implied physical significance, especially on the contribution of the commensurable periodic extension made by Prof. Weng Wenbo.
基金supported by the National Natural Science Foundation of China (Grant No 31172117)the Anhui Academic and Technical Leaders Fund
文摘The Hooded Crane (Grus monacha) is a waterbird wintering in the wetlands of the middle and lower reaches of the Yangtze River, China. The gradual habitat loss resulting from wetland degradation may have posed negative effects on the structure of our wintering populations. For its effective protection, it is important to conduct an intensive study on the genetic structure of this population. A total of 221 faecal samples, nine feather samples and four muscle samples of Hooded Cranes from four wintering populations, i.e., from Caizi Lake and Shengjin Lake in Anhui, Poyang Lake in Jiangxi and Chongming Dongtan in Shanghai, were collected for this study. Full-length 1103–1104 bp mtDNA D-loop sequences from 72 samples were amplified using PCR. Based on our amplified D-loop sequences and the sequences of two individual birds obtained from GenBank (AB017625 and AB023813), we analyzed the genetic structure of these four wintering Hooded Crane populations. Twenty six variable sites were found among 72 target sequences in the four wintering populations and 23 haplotypes were defined. Genetic diversity analyses showed that the haplotype diversity of Hooded Cranes was 0.823 ± 0.042 with a nucleotide diversity of 0.00157 ± 0.00021. The FST values of the four populations show that there is no significant genetic differentiation among the populations of Hooded Cranes wintering in the middle and lower reaches of the Yangtze River. Tajima’s D and Fu’s tests suggest that the Hooded Crane populations may have experienced population expansion in their evolutionary history.
基金the National Hi-Tech Research and Development Program of China(Grant No.2006AA09A101).
文摘The close relationship between the structure,evolution,and resources environment of the South China Sea is a current research focus and also a focal point of our study.In this paper,we use regional seismic sections to analyze the relationship between seismic facies and the structure and tectonic evolution of the northeastern South China Sea and propose new points about the structure and the direction of block(land mass) motion.First,the tectonic features are clear and can be divided into five different structural units which are both linked and independent of each other.Second,it doesn't matter if the South China Sea basin pattern is extensional,weakly compressive,or strongly compressive,the regional tectonic stress field is unified.For the first time we find that two shallow subduction zones are recognized in the seismic profiles.All the tectonic blocks have accordion-fold-style structures,converging in the east,and the South China Sea exhibits different stages of basin development:growth, maturity,end,and termination.The block subduction and regional block dip directions are all aligned with the regional stress field.
基金Supported by the Research Project of Dongguan Higher Education (200910815252)the Beijing Natural Science Foundation(7102102)the Scientific Research Key Program of Beijing Municipal Commission of Ed-ucation(KZ200810025011)~~
文摘To evaluate the effect of the positive-indefinite matrix on the diffusion tensor-derived parameters, a modified algorithm is proposed for calculating these parameters. Magnetic resonance (MR) diffusion tensor images of five healthy volunteers are collected. The diffusion sensitive gradient magnetic fields are applied along 25 directions and the diffusion weighting value is 1 000 s/mm^2. Many positive-indefinite diffusion tensors can be found in the white matter area, such as the genu and the splenium of corpus callosum. Due to the positive-indefinite matrix, the mean diffusivity (MD) and the fractional anisotropy (FA) are under-estimated and over-estimated by using the conventional algorithm. Thus, the conventional algorithm is modified by using the absolute values of all eigenvalues. Results show that both the robustness and the reliability for deriving these parameters are improved by the modified algorithm.
基金Foundation items:The National Natural Science Foundation of China (No.10571026)the Specialized Research Fund for the Doctoral Program ofHigher Education (No.20060286006)
文摘A ring R is said to be satisfying P-stable range provided that whenever aR + bR = R, there exists y ∈ P(R) such that a + by is a unit of R, where P(R) is the subset of R which satisfies the property that up, pu∈ P(R) for every unit u of R and p ∈P(R). By studying this ring, some known results of rings satisfying unit-1 stable range, ( S, 2) -stable range, weakly unit 1- stable range and stable range one are unified. An element of a ring is said to be UR if it is the sum of a unit and a regular dement and a ring is said to be satisfying UR-stable range if R has P-stable range and P(R) is the set of all UR-elements of R, Some properties of this ring are studied and it is proven that if R satisfies UR-stahle range then so does any n × n matrix ring over R.
基金The National Natural Science Foundation of China(No10571026),the Natural Science Foundation of Jiangsu Province(NoBK2005207), the Teaching and Research Award Program for Out-standing Young Teachers in Higher Education Institutions of MOE,PRC
文摘The exchange rings without unity, first introduced by Ara, are further investigated. Some new characterizations and properties of exchange general rings are given. For example, a general ring I is exchange if and only if for any left ideal L of I and a^-= a^-2 ∈I/L, there exists w ∈ r. ureg(I) such that w^- = a^-; E(R, I) ( the ideal extension of a ring R by its ideal I) is an exchange ring if and only if R and I are both exchange. Furthermore, it is presented that if I is a two-sided ideal of a unital ring R and I is an exchange general ring, then every central element of I is a clean element in 1.
文摘In this paper, we shall define a new concept, P map. Therefore the question which arises in will be answered satisfactorily, i.e. a frame map f: K→L from a T 2 frame K to a T 2 frame L can be uniquely extended to a frame map τf:τK→τL if and only if f is a P map.
文摘A series of new 2 (alkylthio) 5,7 dimethyl 1,2,4 triazolopyrimidines and 3 (alkylthio) 5,7 dimethyl 1,2,4 triazolopyrimidines have been synthesized. These derivatives were evaluated for inhibitory effects on 85 7 mmol·L 1 K + and 10 4 mmol·L -1 NE (nor epinephrine) induced contraction of rat aorta strips.
文摘Objective:To investigate the effect of Fufang Danshen pill on bone marrow stem mobilization during myocardial scathe. Methods:Rat models with expansionary myocardial disease were established by Pituitrin and Furazolidone. Experimental rats were divided into the contrast group, the myocardial scathe group (MS group), the myocardial scathe and Fufang Dansben pill group ( MS + FD group) and the myocardial scathe and fluvastatin group ( MS + FT group). The ratio of CD34^+ cells was examined at the 1^st, 3^nl and 6^th weekend. Index of heart structure and function including LVESD, LVEDD. LYEF, LVEDP and dp/dtmax were evaluated at the 6^th weekend. The HW/BW index was calculated. Results:In the MS group, the index of HW/BW, LVESD, LVEDD and LVEDP were obviously increased (P 〈 0.01 ) and index of dp/ dtmax and LVEF were obviously decreased (P 〈 0.05 ). The ratio of CD34^+ cells was significantly improved at the 1^at weekend and then reduced slowly with no difference from that of the contrast group at the 6th weekend. Compared the MS + FD group and the MS + FT group with the MS group, the index of HW/BW, LYESD, LYEDD and LYEDP of were signifi cantly decreased ( P 〈 0.05 ) and index of dp/dtmax and LVEF were increased (P 〈 0.01 ). The ratio of CD34^+ cells was significantly higher at the 1^st, 3^nl and 6^th weekend, but had no statistic meaning at 3^nl and 6^th weekend (P 〉 0.05 ). Conclusion:Pituitrin and Furazolidone can be used to establish rat models with expansionary myocardial disease. There has bone marrow stem mobilization during the early period of myocardial scathe. Fufang Danshen pill has effect on improving bone marrow stem mobilization, lightening the expansionary degree of heart and protecting the heart function. The effect of Fufang Danshen pill is as same as that of fluvastatin.
文摘AIM: TO introduce a new method: small endoscopic sphincterotomy (ES) combined with endoscopic papillary large balloon dilation (SES + EPLBD) to treat patients with large biliary stones.METHODS: Retrieval of large biliary stones was performed in 88 patients. Mean stone size was 14 ± 3 mm and mean number of stones was 2.5 ± 3.5. Firstly, ES with a small incision was performed. Next, endoscopic papillary dilation was performed with a large balloon to slowly match the size of the bile duct. Stones were then retrieved from the biliary duct with a balloon and a basket.RESULTS: Stone retrieval was successful in all cases except one cystic duct stone case without the need to crush large stones. Mean procedure time was 30 ± 5 min. Dilating the papillary orifice with a large balloon made it possible to remove large stones smoothly without crushing them. After dilation with the large balloon, there were some instances of oozing, but no perforations. One instance of post-procedural pancreatitis (1%) occurred. CONCLUSION: SES + EPLBD was effective for the retrieval of large biliary stones without the use of mechanical lithotripsy.
文摘AIM: To study the patients with main pancreatic duct dilation on computed tomography (CT) and thereby to provide the predictive criteria to identify patients at high risk of significant diseases, such as pancreatic cancer, and to avoid unnecessary work up for patients at low risk of such diseases. METHODS: Patients with dilation of the main pancreatic duct on CT at Emory University Hospital in 2002 were identified by computer search. Clinical course and ultimate diagnosis were obtained in all the identified patients by abstraction of their computer database records. RESULTS: Seventy-seven patients were identified in this study. Chronic pancreatitis and pancreatic cancer were the most common causes of the main pancreatic duct dilation on CT. Although the majority of patients with isolated dilation of the main pancreatic duct (single duct dilation) had chronic pancreatitis, one-third of patients with single duct dilation but without chronic pancreatitis had pancreatic malignancies, whereas most of patients with concomitant biliary duct dilation (double duct dilation) had pancreatic cancer. CONCLUSION: Patients with pancreatic double duct dilation need extensive work up and careful followup since a majority of these patients are ultimately diagnosed with pancreatic cancer. Patients with single duct dilation, especially such patients without any evidence of chronic pancreatitis, also need careful follow-up since the possibility of pancreatic malignancy, including adenocarcinoma and intraductal papillary mucinous tumors, is still high.