地理信息系统（geographic information systems，GIS）是用于收集、检查、处理、集成和分析与地表相关信息的计算机系统，将地理空间数据与计算机技术相结合，以空间数据库为基础，对空间数据进行处理、分析、显示与更新[1]。目前GIS...地理信息系统（geographic information systems，GIS）是用于收集、检查、处理、集成和分析与地表相关信息的计算机系统，将地理空间数据与计算机技术相结合，以空间数据库为基础，对空间数据进行处理、分析、显示与更新[1]。目前GIS在公共卫生领域为公共卫生从业人员提供了一个有用的研究工具。传染病的流行因素与地理空间有着密不可分的联系，传染病的发生与流行，许多疾病的地方高发性特点等都与空间信息密切相关。展开更多
移动低占空比无线传感器网络是近年来出现的新型网络。在移动低占空比无线传感器网络中,由于节点的存储空间有限,并且节点的移动及睡眠会导致网络不连通、数据无法及时传输等问题,使数据很难被快速分发并存储,数据持续性较低。为此,提...移动低占空比无线传感器网络是近年来出现的新型网络。在移动低占空比无线传感器网络中,由于节点的存储空间有限,并且节点的移动及睡眠会导致网络不连通、数据无法及时传输等问题,使数据很难被快速分发并存储,数据持续性较低。为此,提出一种卢比变换码的分布式数据存储(LT-MDS,Luby transform codes based mobile distributed storage)算法,该算法采用一种新的传染病式数据分发方法在节点不断移动的网络中分发数据,使数据能以较低的时延被网络中绝大部分节点接收到,提高了网络的可靠性;节点在接收到数据的同时,利用卢比变换码(LTC,Luby transform code)对数据进行编码存储,使容量有限的节点可以保存更多的数据信息。理论分析和仿真实验表明,LT-MDS算法能够以低时延完成数据分发和存储,同时获得较高的数据持续性。展开更多
AIM To evaluate the prognostic value of site-specific metastases among patients with metastatic pancreaticc arcinoma registered within the Surveillance, Epidemiology and End Results(SEER) database.METHODS SEER databas...AIM To evaluate the prognostic value of site-specific metastases among patients with metastatic pancreaticc arcinoma registered within the Surveillance, Epidemiology and End Results(SEER) database.METHODS SEER database(2010-2013) has been queried through SEER*Stat program to determine the presentation, treatment outcomes and prognostic outcomes of metastatic pancreatic adenocarcinoma according to the site of metastasis. In this study, metastatic pancreatic adenocarcinoma patients were classified according to the site of metastases(liver, lung, bone, brain and distant lymph nodes). We utilized chi-square test to compare the clinicopathological characteristics among different sites of metastases. We used Kaplan-Meier analysis and log-rank testing for survival comparisons. We employed Cox proportional model to perform multivariate analyses of the patient population; and accordingly hazard ratios with corresponding 95%CI were generated. Statistical significance was considered if a two-tailed P value < 0.05 was achieved. RESULTS A total of 13233 patients with stage Ⅳ pancreatic cancer and known sites of distant metastases were identified in the period from 2010-2013 and they were included into the current analysis. Patients with isolated distant nodal involvement or lung metastases have better overall and pancreatic cancer-specific survival compared to patients with isolated liver metastases(for overall survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001)(for pancreatic cancer-specific survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001). Multivariate analysis revealed that age < 65 years, white race, being married, female gender; surgery to the primary tumor and surgery to the metastatic disease were associated with better overall survival and pancreatic cancer-specific survival.CONCLUSION Pancreatic adenocarcinoma patients with isolated liver metastases have worse outcomes compared to patients with isolated lung or distant nodal metastases. Further research is needed to identify the highly selected subset of patients who may benefit from local treatment of the primary tumor and/or metastatic disease.展开更多
文摘地理信息系统（geographic information systems，GIS）是用于收集、检查、处理、集成和分析与地表相关信息的计算机系统，将地理空间数据与计算机技术相结合，以空间数据库为基础，对空间数据进行处理、分析、显示与更新[1]。目前GIS在公共卫生领域为公共卫生从业人员提供了一个有用的研究工具。传染病的流行因素与地理空间有着密不可分的联系，传染病的发生与流行，许多疾病的地方高发性特点等都与空间信息密切相关。
文摘移动低占空比无线传感器网络是近年来出现的新型网络。在移动低占空比无线传感器网络中,由于节点的存储空间有限,并且节点的移动及睡眠会导致网络不连通、数据无法及时传输等问题,使数据很难被快速分发并存储,数据持续性较低。为此,提出一种卢比变换码的分布式数据存储(LT-MDS,Luby transform codes based mobile distributed storage)算法,该算法采用一种新的传染病式数据分发方法在节点不断移动的网络中分发数据,使数据能以较低的时延被网络中绝大部分节点接收到,提高了网络的可靠性;节点在接收到数据的同时,利用卢比变换码(LTC,Luby transform code)对数据进行编码存储,使容量有限的节点可以保存更多的数据信息。理论分析和仿真实验表明,LT-MDS算法能够以低时延完成数据分发和存储,同时获得较高的数据持续性。
文摘AIM To evaluate the prognostic value of site-specific metastases among patients with metastatic pancreaticc arcinoma registered within the Surveillance, Epidemiology and End Results(SEER) database.METHODS SEER database(2010-2013) has been queried through SEER*Stat program to determine the presentation, treatment outcomes and prognostic outcomes of metastatic pancreatic adenocarcinoma according to the site of metastasis. In this study, metastatic pancreatic adenocarcinoma patients were classified according to the site of metastases(liver, lung, bone, brain and distant lymph nodes). We utilized chi-square test to compare the clinicopathological characteristics among different sites of metastases. We used Kaplan-Meier analysis and log-rank testing for survival comparisons. We employed Cox proportional model to perform multivariate analyses of the patient population; and accordingly hazard ratios with corresponding 95%CI were generated. Statistical significance was considered if a two-tailed P value < 0.05 was achieved. RESULTS A total of 13233 patients with stage Ⅳ pancreatic cancer and known sites of distant metastases were identified in the period from 2010-2013 and they were included into the current analysis. Patients with isolated distant nodal involvement or lung metastases have better overall and pancreatic cancer-specific survival compared to patients with isolated liver metastases(for overall survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001)(for pancreatic cancer-specific survival: lung vs liver metastases: P < 0.0001; distant nodal vs liver metastases: P < 0.0001). Multivariate analysis revealed that age < 65 years, white race, being married, female gender; surgery to the primary tumor and surgery to the metastatic disease were associated with better overall survival and pancreatic cancer-specific survival.CONCLUSION Pancreatic adenocarcinoma patients with isolated liver metastases have worse outcomes compared to patients with isolated lung or distant nodal metastases. Further research is needed to identify the highly selected subset of patients who may benefit from local treatment of the primary tumor and/or metastatic disease.
