Query expansion with thesaurus is one of the useful techniques in modern information retrieval (IR). In this paper, a method of query expansion for Chinese IR by using a decaying co-occurrence model is proposed and re...Query expansion with thesaurus is one of the useful techniques in modern information retrieval (IR). In this paper, a method of query expansion for Chinese IR by using a decaying co-occurrence model is proposed and realized. The model is an extension of the traditional co-occurrence model by adding a decaying factor that decreases the mutual information when the distance between the terms increases. Experimental results on TREC-9 collections show this query expansion method results in significant improvements over the IR without query expansion.展开更多
This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are an...This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.展开更多
An approximate approach of querying between heterogeneous ontology-basedinformation systems based on an association matrix is proposed. First, the association matrix isdefined to describe relations between concepts in...An approximate approach of querying between heterogeneous ontology-basedinformation systems based on an association matrix is proposed. First, the association matrix isdefined to describe relations between concepts in two ontologies. Then, a methodof rewriting queriesbased on the association matrix is presented to solve the ontology heterogeneity problem. Itrewrites the queries in one ontology to approximate queries in another ontology based on thesubsumption relations between concepts. The method also uses vectors to represent queries, and thencomputes the vectors with the association matrix; the disjoint relations between concepts can beconsidered by the results. It can get better approximations than the methods currently in use, whichdonot consider disjoint relations. The method can be processed by machines automatically. It issimple to implement and expected to run quite fast.展开更多
[Objective] The aim was to survey and analyze informatization demand in new countryside in Poyang Lake Ecological Economic Zone and to propose counter- measures, [Method] A questionnaire was made among farmers on info...[Objective] The aim was to survey and analyze informatization demand in new countryside in Poyang Lake Ecological Economic Zone and to propose counter- measures, [Method] A questionnaire was made among farmers on informatization de- mands in different regions in Poyang Lake Ecological Economic Zone and the re- sults were analyzed to propose countermeasures promoting informatization. [Result] With strengthening of information awareness, information demands in rural areas in Poyang Lake Ecological Economic Zone change as follows: Information demand car- rier changes from traditional media to modern media; demand on information content changes from one-way to diversified one; demand of information service changes from one-way transmission to interaction and exchange. However, some problems still exist in informatization process, such as poor infrastructure, dispersed information resources, higher information expense and shortage of information-based talents. Hence, the countermeasures were proposed, as follows: Rational security systems should be established; financing should be as diversified as possible; informatization infrastructure should be reinforced; agricultural economic information and informatiza- tion service system should be established. [Conclusion] The research lays foundation for construction of informatization in new countryside in Poyang Lake Ecological Economic Zone.展开更多
AIM:To compare fluoroscopic, endoscopic and guide wire assistance with ultraslim gastroscopy for placement of nasojejunal feeding tubes. METHODS:The information regarding nasojejunal tube placement procedures was retr...AIM:To compare fluoroscopic, endoscopic and guide wire assistance with ultraslim gastroscopy for placement of nasojejunal feeding tubes. METHODS:The information regarding nasojejunal tube placement procedures was retrieved using the gastrointestinal tract database at Tongji Hospital affiliated to Tongji Medical College. Records from 81 patients who underwent nasojejunal tubes placement by different techniques between 2004 and 2011 were reviewed for procedure success and tube-related outcomes. RESULTS:Nasojejunal feeding tubes were successfully placed in 78 (96.3%) of 81 patients. The success rate by fluoroscopy was 92% (23 of 25), by endoscopic technique 96.3% (26 of 27), and by guide wire assistance (whether via transnasal or transoral insertion)100% (23/23, 6/6). The average time for successful placement was 14.9 ± 2.9 min for fluoroscopic placement, 14.8 ± 4.9 min for endoscopic placement, 11.1 ± 2.2 min for guide wire assistance with transnasal gastroscopic placement, and 14.7 ± 1.2 min for transoral gastroscopic placement. Statistically, the duration for the third method was significantly different (P < 0.05) compared with the other three methods. Transnasal placement over a guidewire was significantly faster (P < 0.05) than any of the other approaches. CONCLUSION:Guide wire assistance with transnasal insertion of nasojejunal feeding tubes represents a safe, quick and effective method for providing enteral nutrition.展开更多
Embedded ArcGIS Engine can improve development efficiency of environmental information system. The authors designed the structure, functions and database of the Yongjiang River Basin Water Environment Management Infor...Embedded ArcGIS Engine can improve development efficiency of environmental information system. The authors designed the structure, functions and database of the Yongjiang River Basin Water Environment Management Information System (YRBWEMIS) through the integration of ArcGIS Engine software with VC. The spatial data and attribute data in the YRBWEMIS are stored and managed separately. The system functions include display, query, statistics, spatial analysis and thematic mapping for water pollution sources, water quality, water function regionalization and catchments region.展开更多
The incompatible probability represents an important non-classical phenomenon, and it describes conflicting observed marginal probabilities, which cannot be satisfied with a joint probability. First, the incompatibili...The incompatible probability represents an important non-classical phenomenon, and it describes conflicting observed marginal probabilities, which cannot be satisfied with a joint probability. First, the incompatibility of random variables was defined and discussed via the non-positive semi-definiteness of their covariance matrixes. Then, a method was proposed to verify the existence of incompatible probability for variables. A hypothesis testing was also applied to reexamine the likelihood of the observed marginal probabilities being integrated into a joint probability space, thus showing the statistical significance of incompatible probability cases. A case study with user click-through data provided the initial evidence of the incompatible probability in information retrieval (IR), particularly in user interaction. The experiments indicate that both incompatible and compatible cases can be found in IR data, and informational queries are more likely to be compatible than navigational queries. The results inspire new theoretical perspectives of modeling the complex interactions and phenomena in IR.展开更多
Objectives:This study aimed to assess the reliability and validity of the Chinese version of the Head and Neck Information Needs Questionnaire(HaNiQ).Methods:The HaNiQ was translated into a Chinese version using inter...Objectives:This study aimed to assess the reliability and validity of the Chinese version of the Head and Neck Information Needs Questionnaire(HaNiQ).Methods:The HaNiQ was translated into a Chinese version using internationally recognized forwardand back-translation procedures.The reliability and validity of the HaNiQ were measured using Cronbach’s a coefficient,split-half reliability,exploratory factor analysis,and Pearson correlation analysis.Results:A total of 207 patients in different head and neck cancer(HNC)stages and 174 caregivers completed the Chinese version of the HaNiQ.Internal consistencies varied between good and very well(Cronbach’s α coefficient 0.74-0.90);the split-half coefficient and the content validity index(CVI)of the questionnaire were 83.5%and 83.33%,respectively.The cumulative contribution rates of the 5 subscales in patients with HNCand their caregivers were 62.41%and 61.19%,respectively.However,there are some differences between the Chinese questionnaire for caregiver and the original questionnaire regarding the attribution of items.Items 22,23,and 27 in the Psychosocial subscale of the English version were assigned to the Survivorship subscale in the Chinese version for caregivers.Conclusions:The results demonstrated that the Chinese version of the HaNiQ is a reliable and valid instrument for measuring the information needs of patients with HNC and that of their caregivers.Though the structure of the Chinese versionwas different from the English version for caregivers of HNC patients,the Chinese version of the HaNiQ appears to be reliable and would benefit from further testing.展开更多
Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they...Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they cannot make the reliability adequately explicable. Therefore, a mathematical tool, the unascertained measure, was introduced. First, the basic knowledge of the unascertained sets was introduced briefly. Second, the unascertained measure was defined and credible identification was set up. The method has been introduced into the fields for safety assessment of a jacket loadout procedure. Engineering practices showed that it can complete the safety assessment systematically and scientifically without any assumption. The work should have significance in theory and practice for offshore engineering.展开更多
A questionnaire research in ethics was conducted to get the view of students of medical universities in Shanghai on genomics and genetic discrimination. We find that 66% respondents indicated their willingness to unde...A questionnaire research in ethics was conducted to get the view of students of medical universities in Shanghai on genomics and genetic discrimination. We find that 66% respondents indicated their willingness to understand the genetic information and 79% of respondents mind their own genetic information be aware of by other people. In contrast, 77% of the respondents believe that medical organization are not able to protect personal genetic information from disclose. Hence, it is significant to take some measures to preserve citizen's genetic information privacy. Depending on our results, we put forward our suggestion to this problem.展开更多
To eliminate the mismatch between words of relevant documents and user's query and more seriousnegative effects it has on the performance of information retrieval,a method of query expansion on the ba-sis of new t...To eliminate the mismatch between words of relevant documents and user's query and more seriousnegative effects it has on the performance of information retrieval,a method of query expansion on the ba-sis of new terms co-occurrence representation was put forward by analyzing the process of producingquery.The expansion terms were selected according to their correlation to the whole query.At the sametime,the position information between terms were considered.The experimental result on test retrievalconference(TREC)data collection shows that the method proposed in the paper has made an improve-ment of 5%~19% all the time than the language modeling method without expansion.Compared to thepopular approach of query expansion,pseudo feedback,the precision of the proposed method is competi-tive.展开更多
Farmer's willingness for purchasing information, an important factor of farmer's information demand, was analyzed by logit model, according to the survey data of 535 farmers from eleven cities in Hebei province. The...Farmer's willingness for purchasing information, an important factor of farmer's information demand, was analyzed by logit model, according to the survey data of 535 farmers from eleven cities in Hebei province. The result showed that 6 factors had a significant influence on it, that is, education of farmers, per capita income of farmers, the affordability of information risk, the proportion of agricultural labor households, the type of agricultural production and the rural information service stations. On the basis of these, the related policy recommendations were proposed.展开更多
A novel technique called the bitmap lattice index(BLI) is proposed, which combines the advantages of a wireless broadcasting environment with a road network. Existing road networks are based on the on-demand method: a...A novel technique called the bitmap lattice index(BLI) is proposed, which combines the advantages of a wireless broadcasting environment with a road network. Existing road networks are based on the on-demand method: a server's workload increases as the query request increases when a server sends a client information. To solve this problem, we propose the BLI. The BLI denotes an object and a node as 0 and 1 in the Hilbert curve(HC) map. The BLI can identify the position of a node and an object through bit information; it can also reduce the broadcasting frequency of a server by reducing the size of the index, thereby decreasing the access latency and query processing times. Moreover, the BLI is highly effective for data filtering, as it can identify the positions of both an object and a node. In a road network, if filtering is done via the Euclidean distance, it may result in an error. To prevent this, we add another validation procedure. The experiment is conducted by applying the BLI to kNN query, and the technique is assessed by a performance evaluation experiment.展开更多
Background Echocardiography has been shown to be a valuable resource in the diagnosis of many cardiac conditions, and can be used in all age groups, from the fetus to the oldest old. In the context of an increasingly ...Background Echocardiography has been shown to be a valuable resource in the diagnosis of many cardiac conditions, and can be used in all age groups, from the fetus to the oldest old. In the context of an increasingly aging population, the impact and utility of echocar- diography in centenarians is largely unknown. This study is to determine whether echocardiography in centenarians aids in making clinical patient management decisions. Methods A retrospective review of echocardiograms from 1986 to 2014, at two affiliated tertiary centers, in individuals who were 100 years or older at the time of the examination. Patient and echocardiogram characteristics, management decisions based on echocardiography, and mortality were documented. Results 114 centenarians had echocardiograms, with ages ranging from 100 to 107 years (101 - 1.4 years). In 82 of the centenarians evaluated (72%), no changes in management occurred as a consequence of the echocardiogram. From all management changes directly related to the echocardiogram, 81% (n = 26) of these corresponded to medication adjustments; interventional or surgical procedures followed the echocardiogram only in 4% (n = 5) of the total number of centenarians. Echocardiogram-based changes in management were only significant in patients that were referred for congestive heart failure (P = 0.02). After the echocardiogram was performed, 1-month and 1-year mortality were 15% and 47%, respectively. The median survival after the echocardiogram was obtained was 13 months (range 0.03 to 145 months), with no difference if there was a change or no change in manage- ment (P = 0.21). Conclusions Among centenarians undergoing echocardiography, despite additional diagnostic information, echocardio- grams in centenarians influence management in a minority of cases, most commonly in the form of medication changes for treatment of heart failure. A significant proportion of centenarians are deceased within a year of undergoing echocardiographic assessment. These findings may question the overall utility of echocardiography in these late survivors.展开更多
This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics i...This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5 mu m or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER's urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.展开更多
A theoretical protocol of quantum dialogue is proposed,which uses a class of three-photon W states asquantum channel.After two-step security check,four-bit secret message can be transmitted to each other by transmitti...A theoretical protocol of quantum dialogue is proposed,which uses a class of three-photon W states asquantum channel.After two-step security check,four-bit secret message can be transmitted to each other by transmittingof single photon with the aid of two-bit classical information.展开更多
文摘Query expansion with thesaurus is one of the useful techniques in modern information retrieval (IR). In this paper, a method of query expansion for Chinese IR by using a decaying co-occurrence model is proposed and realized. The model is an extension of the traditional co-occurrence model by adding a decaying factor that decreases the mutual information when the distance between the terms increases. Experimental results on TREC-9 collections show this query expansion method results in significant improvements over the IR without query expansion.
文摘This paper focuses on exporting relational data into extensible markup language (XML). First, the characteristics of both relational schemas represented by E-R diagrams and XML document type definitions (DTDs) are analyzed. Secondly, the corresponding mapping rules are proposed. At last an algorithm based on edge tables is presented. There are two key points in the algorithm. One is that the edge table is used to store the information of the relational dictionary, and this brings about the efficiency of the algorithm. The other is that structural information can be obtained from the resulting DTDs and other applications can optimize their query processes using the structural information.
文摘An approximate approach of querying between heterogeneous ontology-basedinformation systems based on an association matrix is proposed. First, the association matrix isdefined to describe relations between concepts in two ontologies. Then, a methodof rewriting queriesbased on the association matrix is presented to solve the ontology heterogeneity problem. Itrewrites the queries in one ontology to approximate queries in another ontology based on thesubsumption relations between concepts. The method also uses vectors to represent queries, and thencomputes the vectors with the association matrix; the disjoint relations between concepts can beconsidered by the results. It can get better approximations than the methods currently in use, whichdonot consider disjoint relations. The method can be processed by machines automatically. It issimple to implement and expected to run quite fast.
文摘[Objective] The aim was to survey and analyze informatization demand in new countryside in Poyang Lake Ecological Economic Zone and to propose counter- measures, [Method] A questionnaire was made among farmers on informatization de- mands in different regions in Poyang Lake Ecological Economic Zone and the re- sults were analyzed to propose countermeasures promoting informatization. [Result] With strengthening of information awareness, information demands in rural areas in Poyang Lake Ecological Economic Zone change as follows: Information demand car- rier changes from traditional media to modern media; demand on information content changes from one-way to diversified one; demand of information service changes from one-way transmission to interaction and exchange. However, some problems still exist in informatization process, such as poor infrastructure, dispersed information resources, higher information expense and shortage of information-based talents. Hence, the countermeasures were proposed, as follows: Rational security systems should be established; financing should be as diversified as possible; informatization infrastructure should be reinforced; agricultural economic information and informatiza- tion service system should be established. [Conclusion] The research lays foundation for construction of informatization in new countryside in Poyang Lake Ecological Economic Zone.
文摘AIM:To compare fluoroscopic, endoscopic and guide wire assistance with ultraslim gastroscopy for placement of nasojejunal feeding tubes. METHODS:The information regarding nasojejunal tube placement procedures was retrieved using the gastrointestinal tract database at Tongji Hospital affiliated to Tongji Medical College. Records from 81 patients who underwent nasojejunal tubes placement by different techniques between 2004 and 2011 were reviewed for procedure success and tube-related outcomes. RESULTS:Nasojejunal feeding tubes were successfully placed in 78 (96.3%) of 81 patients. The success rate by fluoroscopy was 92% (23 of 25), by endoscopic technique 96.3% (26 of 27), and by guide wire assistance (whether via transnasal or transoral insertion)100% (23/23, 6/6). The average time for successful placement was 14.9 ± 2.9 min for fluoroscopic placement, 14.8 ± 4.9 min for endoscopic placement, 11.1 ± 2.2 min for guide wire assistance with transnasal gastroscopic placement, and 14.7 ± 1.2 min for transoral gastroscopic placement. Statistically, the duration for the third method was significantly different (P < 0.05) compared with the other three methods. Transnasal placement over a guidewire was significantly faster (P < 0.05) than any of the other approaches. CONCLUSION:Guide wire assistance with transnasal insertion of nasojejunal feeding tubes represents a safe, quick and effective method for providing enteral nutrition.
文摘Embedded ArcGIS Engine can improve development efficiency of environmental information system. The authors designed the structure, functions and database of the Yongjiang River Basin Water Environment Management Information System (YRBWEMIS) through the integration of ArcGIS Engine software with VC. The spatial data and attribute data in the YRBWEMIS are stored and managed separately. The system functions include display, query, statistics, spatial analysis and thematic mapping for water pollution sources, water quality, water function regionalization and catchments region.
基金Supported by National Basic Research Program of China("973"Program,No.2013cb329304)Natural Science Foundation of China(No.61105072,No.61070044 and No.61111130190)International Joint Research Project"QONTEXT"of the Council of European Union
文摘The incompatible probability represents an important non-classical phenomenon, and it describes conflicting observed marginal probabilities, which cannot be satisfied with a joint probability. First, the incompatibility of random variables was defined and discussed via the non-positive semi-definiteness of their covariance matrixes. Then, a method was proposed to verify the existence of incompatible probability for variables. A hypothesis testing was also applied to reexamine the likelihood of the observed marginal probabilities being integrated into a joint probability space, thus showing the statistical significance of incompatible probability cases. A case study with user click-through data provided the initial evidence of the incompatible probability in information retrieval (IR), particularly in user interaction. The experiments indicate that both incompatible and compatible cases can be found in IR data, and informational queries are more likely to be compatible than navigational queries. The results inspire new theoretical perspectives of modeling the complex interactions and phenomena in IR.
基金This research was supported by Beijing University of Chinese Medicine [2020-JYB-ZDGG-081].
文摘Objectives:This study aimed to assess the reliability and validity of the Chinese version of the Head and Neck Information Needs Questionnaire(HaNiQ).Methods:The HaNiQ was translated into a Chinese version using internationally recognized forwardand back-translation procedures.The reliability and validity of the HaNiQ were measured using Cronbach’s a coefficient,split-half reliability,exploratory factor analysis,and Pearson correlation analysis.Results:A total of 207 patients in different head and neck cancer(HNC)stages and 174 caregivers completed the Chinese version of the HaNiQ.Internal consistencies varied between good and very well(Cronbach’s α coefficient 0.74-0.90);the split-half coefficient and the content validity index(CVI)of the questionnaire were 83.5%and 83.33%,respectively.The cumulative contribution rates of the 5 subscales in patients with HNCand their caregivers were 62.41%and 61.19%,respectively.However,there are some differences between the Chinese questionnaire for caregiver and the original questionnaire regarding the attribution of items.Items 22,23,and 27 in the Psychosocial subscale of the English version were assigned to the Survivorship subscale in the Chinese version for caregivers.Conclusions:The results demonstrated that the Chinese version of the HaNiQ is a reliable and valid instrument for measuring the information needs of patients with HNC and that of their caregivers.Though the structure of the Chinese versionwas different from the English version for caregivers of HNC patients,the Chinese version of the HaNiQ appears to be reliable and would benefit from further testing.
基金the National Natural Science Foundation of China (505079047)
文摘Safety assessment of offshore platforms is an urgent task. Such assessments are now focusing on the structure, maintenance, and retirement of a platform. Some methods employed have many shortcomings. For example, they cannot make the reliability adequately explicable. Therefore, a mathematical tool, the unascertained measure, was introduced. First, the basic knowledge of the unascertained sets was introduced briefly. Second, the unascertained measure was defined and credible identification was set up. The method has been introduced into the fields for safety assessment of a jacket loadout procedure. Engineering practices showed that it can complete the safety assessment systematically and scientifically without any assumption. The work should have significance in theory and practice for offshore engineering.
文摘A questionnaire research in ethics was conducted to get the view of students of medical universities in Shanghai on genomics and genetic discrimination. We find that 66% respondents indicated their willingness to understand the genetic information and 79% of respondents mind their own genetic information be aware of by other people. In contrast, 77% of the respondents believe that medical organization are not able to protect personal genetic information from disclose. Hence, it is significant to take some measures to preserve citizen's genetic information privacy. Depending on our results, we put forward our suggestion to this problem.
基金the High Technology Research and Development Program of China(No.2006AA01Z150)the National Natural Science Foundation of China(No.60435020)
文摘To eliminate the mismatch between words of relevant documents and user's query and more seriousnegative effects it has on the performance of information retrieval,a method of query expansion on the ba-sis of new terms co-occurrence representation was put forward by analyzing the process of producingquery.The expansion terms were selected according to their correlation to the whole query.At the sametime,the position information between terms were considered.The experimental result on test retrievalconference(TREC)data collection shows that the method proposed in the paper has made an improve-ment of 5%~19% all the time than the language modeling method without expansion.Compared to thepopular approach of query expansion,pseudo feedback,the precision of the proposed method is competi-tive.
文摘Farmer's willingness for purchasing information, an important factor of farmer's information demand, was analyzed by logit model, according to the survey data of 535 farmers from eleven cities in Hebei province. The result showed that 6 factors had a significant influence on it, that is, education of farmers, per capita income of farmers, the affordability of information risk, the proportion of agricultural labor households, the type of agricultural production and the rural information service stations. On the basis of these, the related policy recommendations were proposed.
基金supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by the Ministry of Education, Science and Technology (NRF2013R1A1A1004593, 2013R1A1A1A05012348)
文摘A novel technique called the bitmap lattice index(BLI) is proposed, which combines the advantages of a wireless broadcasting environment with a road network. Existing road networks are based on the on-demand method: a server's workload increases as the query request increases when a server sends a client information. To solve this problem, we propose the BLI. The BLI denotes an object and a node as 0 and 1 in the Hilbert curve(HC) map. The BLI can identify the position of a node and an object through bit information; it can also reduce the broadcasting frequency of a server by reducing the size of the index, thereby decreasing the access latency and query processing times. Moreover, the BLI is highly effective for data filtering, as it can identify the positions of both an object and a node. In a road network, if filtering is done via the Euclidean distance, it may result in an error. To prevent this, we add another validation procedure. The experiment is conducted by applying the BLI to kNN query, and the technique is assessed by a performance evaluation experiment.
文摘Background Echocardiography has been shown to be a valuable resource in the diagnosis of many cardiac conditions, and can be used in all age groups, from the fetus to the oldest old. In the context of an increasingly aging population, the impact and utility of echocar- diography in centenarians is largely unknown. This study is to determine whether echocardiography in centenarians aids in making clinical patient management decisions. Methods A retrospective review of echocardiograms from 1986 to 2014, at two affiliated tertiary centers, in individuals who were 100 years or older at the time of the examination. Patient and echocardiogram characteristics, management decisions based on echocardiography, and mortality were documented. Results 114 centenarians had echocardiograms, with ages ranging from 100 to 107 years (101 - 1.4 years). In 82 of the centenarians evaluated (72%), no changes in management occurred as a consequence of the echocardiogram. From all management changes directly related to the echocardiogram, 81% (n = 26) of these corresponded to medication adjustments; interventional or surgical procedures followed the echocardiogram only in 4% (n = 5) of the total number of centenarians. Echocardiogram-based changes in management were only significant in patients that were referred for congestive heart failure (P = 0.02). After the echocardiogram was performed, 1-month and 1-year mortality were 15% and 47%, respectively. The median survival after the echocardiogram was obtained was 13 months (range 0.03 to 145 months), with no difference if there was a change or no change in manage- ment (P = 0.21). Conclusions Among centenarians undergoing echocardiography, despite additional diagnostic information, echocardio- grams in centenarians influence management in a minority of cases, most commonly in the form of medication changes for treatment of heart failure. A significant proportion of centenarians are deceased within a year of undergoing echocardiographic assessment. These findings may question the overall utility of echocardiography in these late survivors.
文摘This study was undertaken to construct a preliminary spatial analysis method for building an urban-suburban-rural category in the specific sample area of central California and providing distribution characteristics in each category, based on which, some further studies such as regional manners of residential wood burning emission (PM2.5, the term used for a mixture of solid particles and liquid droplets found in the air, refers to particulate matter that is 2.5 mu m or smaller in size) could be carried out for the project of residential wood combustion. Demographic and infrastructure data with spatial characteristics were processed by integrating both Geographic Information System (GIS) and statistics method (Cluster Analysis), and then output to a category map as the result. It approached the quantitative and multi-variables description on the major characteristics variations among the urban, suburban and rural; and perfected the TIGER's urban-rural classification scheme by adding suburban category. Based on the free public GIS data, the spatial analysis method provides an easy and ideal tool for geographic researchers, environmental planners, urban/regional planners and administrators to delineate different categories of regional function on the specific locations and dig out spatial distribution information they wanted. Furthermore, it allows for future adjustment on some parameters as the spatial analysis method is implemented in the different regions or various eco-social models.
基金Supported by the National Natural Science Foundation of China under Grant No.10704011the Research Programs of the Educational Office of Liaoning Province under Grant No.2008006
文摘A theoretical protocol of quantum dialogue is proposed,which uses a class of three-photon W states asquantum channel.After two-step security check,four-bit secret message can be transmitted to each other by transmittingof single photon with the aid of two-bit classical information.