AIM:To determine the basic demographic features of colorectal cancer (CRC) in five hospitals located in four different areas of Guangdong Province,China.METHODS:A review of patient records from 1986 to 2006 from five ...AIM:To determine the basic demographic features of colorectal cancer (CRC) in five hospitals located in four different areas of Guangdong Province,China.METHODS:A review of patient records from 1986 to 2006 from five hospitals was conducted. Patient data was obtained,including age,gender,location of le-sions,staging and histological type of CRC. The Chi-square test was used to assess differences in rates and a significance level of 0.05 was used. Univariate com-parisons were made via Fisher's exact tests.RESULTS:Analysis was carried out on 8172 CRC patents,6.1% (499/8172) of the patients were aged ≤ 30 years. The peak incidence was between the ages 61-70 years (27.8%). The mean age at CRC diagnosis increased from 52 years (1986-1988) to 60 years(2004-2006) and the proportion of young CRC patients decreased from 8.0% to 5.9% over the same period. Of 8172 lesions,4434 (54.3%) were located in rectum and 3738 (45.7%) in colon. The incidence of rectal cancer decreased significantly from 59.4% (1989-1991) to 51.8% (2004-2006) and right sided colon cancer increased from 40.6% to 48.2%. The mean age,ana-tomic distribution,histological type and differentiation degree were significantly different among the four geographical areas (P < 0.05).CONCLUSION:The hospitalization rate for CRC has increased in Guangdong in recent years. The characteristics of CRC from the five hospitals located in the four different areas of Guangdong Province are also different. Further studies are needed to assess more recent trend in the incidence and prevalence of CRC as well as the respective roles of genetic and environ-mental factors in CRC.展开更多
随着分布式能源的大量接入和电力系统运行方式的逐渐转变,社区微网系统(community microgrid system,CMS)中用户已经从传统的消费者转变为具有电能生产/消费行为的产消者。在此背景下,通过引入点对点(peer to peer,P2P)能源交易机制,实...随着分布式能源的大量接入和电力系统运行方式的逐渐转变,社区微网系统(community microgrid system,CMS)中用户已经从传统的消费者转变为具有电能生产/消费行为的产消者。在此背景下,通过引入点对点(peer to peer,P2P)能源交易机制,实现社区微网系统中的产消者自主能量管理以及自主竞价策略最终达成P2P能量交易。首先,考虑产消者的差异化特征,对CMS内部资源自主形成的4种典型类型的产消者进行整合和建模。然后,基于连续双边拍卖机制搭建了日前阶段多类型产消者P2P能量交易框架,各产消者考虑历史交易决策信息以个体利益最大为目标,并通过交互有限的信息,在产消者之间互相发起交易请求,实现CMS内产消者之间P2P能量交易。针对在交易过程中产消者可能出现的隐私性保护,提出基于多段报价机制的P2P竞价策略,既能降低交易方的信息暴露风险,又能减少单次竞价决策的风险度,保证产消者收益稳定。最后,通过算例验证文中设计的P2P交易机制能够有效保护产消者的交易隐私性的同时,提高其经济效益。展开更多
OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was ...OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was undertaken to identify English articles about the growth of neural stem cells in vitro published from January 2000 to October 2006 by using the keywords of ＂neural stem cells, bone marrow mesenchymal stem cells （BMSCs）, umbilical cord blood stem cells, embryonic stem cells （ESC）, separation methods, neural growth factor＂. And relevant articles published in IEEE/IEE Electronic Library （IEL） database, Springer Link database and Kluwer Online Journals were also searched, Chinese relevant articles published between January 2000 to October 2006 were searched with the same keywords in Chinese in Chinese journal full-text database. STUDY SELECTION ： The articles were primarily screened, and then the full-texts were searched. Inclusive criteria： （1） Articles relevant to the biological characteristics and classification of neural stem cells; （2） Articles about the source, separation and differentiation of the ESCs, BMSCs and umbilical cord blood stem cells. The repetitive studies and reviews were excluded. DATA EXTRACTION ： Thirty articles were selected from 203 relevant articles according to the inclusive criteria Articles were excluded because of repetition and reviews. DATA SYNTHESES ： Neural stem cells have the ability of self-renewing and high differentiation, and they are obtained from ESCs, nerve tissue, nerve system, BMSCs and umbilical cord blood stem cells. ESCs can be separated by means of mechanical dissociation is better than that of the trypsin digestion, BMSCs by density gradient centrifuge separation, hemolysis, whole-blood culture, etc., and umbilical cord blood stem ceils by Ficoil density gradient centrifugation, hydroxyethyl starch （HES） centrifugation sedimentation, etc. Neural growth factor （NGF） and other factors play an important role in the gr展开更多
The quantity and survival time of astrocytes,which were differentiated from adult adipose-derived stromal cells after exposure to an inducer containing 3-isobutyl-1-methylxanthine,have thus far been unsatisfactory.The...The quantity and survival time of astrocytes,which were differentiated from adult adipose-derived stromal cells after exposure to an inducer containing 3-isobutyl-1-methylxanthine,have thus far been unsatisfactory.The present study investigated the growth and differentiation characteristics of induced astrocytes by observing their growth curves.After induction for 48 hours with an inducer containing 0.5% ethanol,some adult adult adipose-derived stromal cells displayed typical astrocytic morphology.The cell quantity gradually decreased with prolonged induction time.Nestin,glial fibrillary acidic protein,and S-100 expression reached peak levels at 14 days,but neuron-specific enolase was not expressed.These results suggest that the induced astrocytes reached their peak at 14 days.Further optimization of the culture environment may yield mature astrocytes with normal functions,in greater quantity,and prolonged survival time.展开更多
文摘AIM:To determine the basic demographic features of colorectal cancer (CRC) in five hospitals located in four different areas of Guangdong Province,China.METHODS:A review of patient records from 1986 to 2006 from five hospitals was conducted. Patient data was obtained,including age,gender,location of le-sions,staging and histological type of CRC. The Chi-square test was used to assess differences in rates and a significance level of 0.05 was used. Univariate com-parisons were made via Fisher's exact tests.RESULTS:Analysis was carried out on 8172 CRC patents,6.1% (499/8172) of the patients were aged ≤ 30 years. The peak incidence was between the ages 61-70 years (27.8%). The mean age at CRC diagnosis increased from 52 years (1986-1988) to 60 years(2004-2006) and the proportion of young CRC patients decreased from 8.0% to 5.9% over the same period. Of 8172 lesions,4434 (54.3%) were located in rectum and 3738 (45.7%) in colon. The incidence of rectal cancer decreased significantly from 59.4% (1989-1991) to 51.8% (2004-2006) and right sided colon cancer increased from 40.6% to 48.2%. The mean age,ana-tomic distribution,histological type and differentiation degree were significantly different among the four geographical areas (P < 0.05).CONCLUSION:The hospitalization rate for CRC has increased in Guangdong in recent years. The characteristics of CRC from the five hospitals located in the four different areas of Guangdong Province are also different. Further studies are needed to assess more recent trend in the incidence and prevalence of CRC as well as the respective roles of genetic and environ-mental factors in CRC.
文摘随着分布式能源的大量接入和电力系统运行方式的逐渐转变,社区微网系统(community microgrid system,CMS)中用户已经从传统的消费者转变为具有电能生产/消费行为的产消者。在此背景下,通过引入点对点(peer to peer,P2P)能源交易机制,实现社区微网系统中的产消者自主能量管理以及自主竞价策略最终达成P2P能量交易。首先,考虑产消者的差异化特征,对CMS内部资源自主形成的4种典型类型的产消者进行整合和建模。然后,基于连续双边拍卖机制搭建了日前阶段多类型产消者P2P能量交易框架,各产消者考虑历史交易决策信息以个体利益最大为目标,并通过交互有限的信息,在产消者之间互相发起交易请求,实现CMS内产消者之间P2P能量交易。针对在交易过程中产消者可能出现的隐私性保护,提出基于多段报价机制的P2P竞价策略,既能降低交易方的信息暴露风险,又能减少单次竞价决策的风险度,保证产消者收益稳定。最后,通过算例验证文中设计的P2P交易机制能够有效保护产消者的交易隐私性的同时,提高其经济效益。
文摘OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was undertaken to identify English articles about the growth of neural stem cells in vitro published from January 2000 to October 2006 by using the keywords of ＂neural stem cells, bone marrow mesenchymal stem cells （BMSCs）, umbilical cord blood stem cells, embryonic stem cells （ESC）, separation methods, neural growth factor＂. And relevant articles published in IEEE/IEE Electronic Library （IEL） database, Springer Link database and Kluwer Online Journals were also searched, Chinese relevant articles published between January 2000 to October 2006 were searched with the same keywords in Chinese in Chinese journal full-text database. STUDY SELECTION ： The articles were primarily screened, and then the full-texts were searched. Inclusive criteria： （1） Articles relevant to the biological characteristics and classification of neural stem cells; （2） Articles about the source, separation and differentiation of the ESCs, BMSCs and umbilical cord blood stem cells. The repetitive studies and reviews were excluded. DATA EXTRACTION ： Thirty articles were selected from 203 relevant articles according to the inclusive criteria Articles were excluded because of repetition and reviews. DATA SYNTHESES ： Neural stem cells have the ability of self-renewing and high differentiation, and they are obtained from ESCs, nerve tissue, nerve system, BMSCs and umbilical cord blood stem cells. ESCs can be separated by means of mechanical dissociation is better than that of the trypsin digestion, BMSCs by density gradient centrifuge separation, hemolysis, whole-blood culture, etc., and umbilical cord blood stem ceils by Ficoil density gradient centrifugation, hydroxyethyl starch （HES） centrifugation sedimentation, etc. Neural growth factor （NGF） and other factors play an important role in the gr
文摘The quantity and survival time of astrocytes,which were differentiated from adult adipose-derived stromal cells after exposure to an inducer containing 3-isobutyl-1-methylxanthine,have thus far been unsatisfactory.The present study investigated the growth and differentiation characteristics of induced astrocytes by observing their growth curves.After induction for 48 hours with an inducer containing 0.5% ethanol,some adult adult adipose-derived stromal cells displayed typical astrocytic morphology.The cell quantity gradually decreased with prolonged induction time.Nestin,glial fibrillary acidic protein,and S-100 expression reached peak levels at 14 days,but neuron-specific enolase was not expressed.These results suggest that the induced astrocytes reached their peak at 14 days.Further optimization of the culture environment may yield mature astrocytes with normal functions,in greater quantity,and prolonged survival time.
