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1.
目的:探讨血清糖类抗原CA199糖类抗原CA724癌胚抗原CEA在结直肠癌的TNM分期中的临床应用价值。方法:观察组结直肠癌患者100例与对照组同期非消化道肿瘤的住院病人100例,空腹抽取静脉血,采用罗氏公司E601电化学发光全自动免疫分析仪和罗氏原装试剂盒检测血清中CEA、CA199、CA724值。应用SPSS 17.0软件进行统计学处理,计量资料以均数±标准差f±s)表示,采用单因素方差分析进行统计,计数资料采用X-2检验,P0.05为差异有统计学意义。结果:在单项检测中,CEA的敏感率最高,达37%,且CEACA199CA724.在两项联合检测中CA199+CEA的敏感度最高达53%,三项联合检测敏感度达64%,在各种联合检测中最高。三项肿瘤标志物的阳性率和升高水平随肿瘤的TNM分期的增加而递增。结论:三项肿瘤标志物的单一检测敏感度较低,肿瘤标志的联合检测结直肠癌可以提高敏感性,以CEA+CA199+CA724的效果最好,CA199+CEA次之。CA199、CA724、CEA三项肿瘤标志物的阳性率及升高水平依肿瘤的TNM分期的增加呈递增趋势。  相似文献   

2.
The association of serum trace elements like selenium, zinc and copper has been found in different types of cancer. This study was conducted to see the serum level of these three trace elements in cancer esophagus patients. Biopsy confirmed cancer esophagus, 24 patients (12 males, 12 females, mean age 54.5±11.65 year with 23 healthy subjects (16 males, 7 females, mean age 44 ±13.82 years) were included in this study. Both control and study group patients were of same socio-economic status and dietary habits. Serum zinc and copper level were estimated using standard absorption spectrometer technique and serum selenium by Hydride generation method. We observed significant low serum levels of zinc and selenium while high level of serum copper in carcinoma esophagus patients, as compared with normal healthy controls. This shows an association of serum selenium zinc and copper with cancer esophagus.  相似文献   

3.
This study was conducted to find out the possible underlying mechanism of various manifestation of fluorosis, a disease caused by excess ingestion of fluoride. For this the fluoride belt of Jaipur district was selected. The parameters selected were serum Parathyroid hormone, the levels of which are directly affected by fluoride intake. The levels of serum seromucoid, serum and leucocyte ascorbic acid, serum sialic acid (SSA) reflects ground substance metabolism. The study was conducted on two hundred children, selected from four areas (50 from each area) consuming water containing 2.4, 4.6, 5.6 and 13.6 mg/l of fluoride. Drinking water fluoride and serum fluoride were measured by Ion selective electrode method. Serum parathyroid by RIA and all other parameters were measured spectrophotometrically. The results revealed an increase in levels of fluoride, parathyroid hormone and seromucoid in serum with increasing water fluoride concentrations. Serum Calcium and serum ascorbic acid were found in normal range, how ever leucocyte ascorbic acid were decreased. A high positive correlation among fluoride concentration in drinking water and serum parathyroid hormone (r=0.967), and, serum parathyroid hormone and serum seromucoid concentration (r=0.935) was also observed The results indicated that secondary hyperparathyroidism due to hypocalcemic stress caused by excess fluoride ingestion disturbs normal metabolism of ground substance in calcified tissues of the body reflected as altered levels of the components of ground substance in the serum.  相似文献   

4.
Collaboration is an important aspect for virtually all workplace environments. Workplaces often encourage and foster collaboration in a variety of ways with the purpose to collectively focus the group's attention on a specific problem and solve it as quickly and as efficiently as possible. While collaboration is generally viewed as a positive aspect of the workplace, the negative aspect—interruption—cannot be ignored. Interruptions are an important research area of human-computer interaction and with the growth of pervasive or ubiquitous computing on the rise, the number of interruptions we experience on a daily basis is also growing. It is for these reasons that interruption is and will continue to be a key issue in workplaces.This report presents the findings of a qualitative research project which explored interruptions in a mid-size software development company based in Ontario, Canada. The purpose of this research was to identify the types of interruptions (both on- and off-task) that occur during typical office software related activities, explore the contextual characteristics surrounding these interruptions, and identify methodologies that could be used to reduce the cost of interruptions and increase employee effectiveness and satisfaction.  相似文献   

5.
This paper proposes collaborative filtering as a means to predict semantic preferences by combining information on social ties with information on links between actors and semantics. First, the authors present an overview of the most relevant collaborative filtering approaches, showing how they work and how they differ. They then compare three different collaborative filtering algorithms using articles published by New York Times journalists from 2003 to 2005 to predict preferences, where preferences refer to journalists’ inclination to use certain words in their writing. Results show that while preference profile similarities in an actor’s neighbourhood are a good predictor of her semantic preferences, information on her social network adds little to prediction accuracy.  相似文献   

6.
生活领域能源消费的锁定效应研究——以上海市为例   总被引:2,自引:0,他引:2  
高然  张真 《资源科学》2015,37(4):733-743
当前,在全社会大力倡导节能行为,节能家电已成为市场主流的背景下,我国人均生活能源消费量却逐年攀升。本文认为,这源于生活领域能源消费的锁定效应,本文从住房面积和收入水平两方面分别探究上述锁定效应的形成过程。基于2013年《上海市居民生活碳消费状况调查数据》,本文首先选取两类面积水平相同的住房类型(类型1:别墅、联排、大平层,类型5:农民独栋别墅),通过多元线性回归分析筛选出显著耗能设备,之后运用逻辑斯蒂回归模型探究拥有上述筛选出的耗能设备的概率与居民收入水平的关系,进而分析收入水平对能源消费的锁定效应;类似地,本文选取两类收入水平相同的住房类型(类型1:别墅、联排、大平层,类型2:高层/小高层),探究住房面积对能源消费的锁定效应。结果表明,收入水平和居住面积影响居民家庭购置、使用功能类似但能耗水平不同的电器,从而形成不同的生活样式,导致居住能耗差异。  相似文献   

7.
The race against ‘Digital Darwinism’ in public sector had caused failures of several high profile large-scale Digitally Enabled Service Transformation (DEST) projects. While technical and managerial issues are often emphasised as the factors underpinning such failures, the vital role of key actors and the interplay between these actors and structures is underplayed when examining the causes of DEST failure. To enable a richer understanding of DEST, this paper proposes an analytical lens combining Institutional Theory (IT) and Structuration Theory (ST) to explore the case of ‘Universal Credit’, a very large and ambitious DEST project in the UK. Analysis reveals that the institutional actors and structures played significant roles in the transformation process. Albeit governing the actors’ actions, institutional structures are shaped through actions that are influenced by knowledge, power and norms. Hence, recognising and addressing these subliminal factors are critical to promote actions that can facilitate DEST success. The contributions of this case study are two-folds. Theoretically, it provides a distinctive conceptual approach to study DEST; and practically, the lessons help in signposting better managerial practices.  相似文献   

8.
This article proposes a process to retrieve the URL of a document for which metadata records exist in a digital library catalog but a pointer to the full text of the document is not available. The process uses results from queries submitted to Web search engines for finding the URL of the corresponding full text or any related material. We present a comprehensive study of this process in different situations by investigating different query strategies applied to three general purpose search engines (Google, Yahoo!, MSN) and two specialized ones (Scholar and CiteSeer), considering five user scenarios. Specifically, we have conducted experiments with metadata records taken from the Brazilian Digital Library of Computing (BDBComp) and The DBLP Computer Science Bibliography (DBLP). We found that Scholar was the most effective search engine for this task in all considered scenarios and that simple strategies for combining and re-ranking results from Scholar and Google significantly improve the retrieval quality. Moreover, we study the influence of the number of query results on the effectiveness of finding missing information as well as the coverage of the proposed scenarios.  相似文献   

9.
This case study analyzes the Internet-based resources that a software engineer uses in his daily work. Methodologically, we studied the web browser history of the participant, classifying all the web pages he had seen over a period of 12 days into web genres. We interviewed him before and after the analysis of the web browser history. In the first interview, he spoke about his general information behavior; in the second, he commented on each web genre, explaining why and how he used them. As a result, three approaches allow us to describe the set of 23 web genres obtained: (a) the purposes they serve for the participant; (b) the role they play in the various work and search phases; (c) and the way they are used in combination with each other. Further observations concern the way the participant assesses quality of web-based resources, and his information behavior as a software engineer.  相似文献   

10.
郑刚  郭艳婷 《科研管理》2017,38(7):62-71
近年来,一些后发企业开始借助更高的资源平台、更广的学习方式和更丰富的能力基础挑战领导企业,而这些变化与起点更高、范围更广、速度更快的"新型技术追赶"密切相关。本文基于动态能力视角,尝试打开后发企业如何通过动态能力进行战略调整、进而从追赶到超越的黑箱。通过对比分析海尔、美的、格力3家家电企业,纵向归纳出新型技术追赶阶段与以往研究在追赶起点、范围和速度上的联系与区别,并通过横向对比三家企业,解释不同赶超路径的成因。通过构建"新型技术追赶"框架并揭示其背后的动态能力架构,以期对那些接近前沿的后发企业做出理论和实践贡献,从多方位、多路径挑战领先者地位,形成真正意义上的全球竞争力。  相似文献   

11.
在面对条件价值评估法估值问题时,由于对待评估物品缺乏认知等原因,部分受访者将对支付意愿金额表现出不确定性,造成不确定性偏差。为识别并修正不确定性偏差,本文以平潭海洋生物多样性价值评估为例,通过增设题项,要求受访者给出支付意愿确切金额或区间范围,以支付意愿区间长度比例衡量受访者不确定性,在此基础上分析不确定性的影响因素,并以不确定性水平对支付意愿区间进行加权,将不确定性纳入支付意愿估值框架以减少偏误,提高条件价值评估法估值精度。结果表明:①不确定性的存在具有普遍性,近50%受访者对支付意愿表现出不确定性。②受访者在当地的居住年限、对海洋生物多样性的了解程度、收入水平均对不确定性具有显著影响。③将不确定性水平纳入支付意愿估计,运用参数估计方法测算福建平潭居民对于保护海洋生物多样性的支付意愿为200.24元/(人·年),平潭海洋生物多样性价值为8888.65万元/年。研究结论将加深对条件价值评估法中不确定性偏差来源及修正方法的理解,提高条件价值评估法估值有效性与准确性,并为海岛生态系统的海洋生物多样性保护与管理、海洋资源可持续利用提供支撑。  相似文献   

12.
高军波  喻超  戈大专  陈建华 《资源科学》2019,41(9):1690-1702
不同地理环境下农户致贫因素的多尺度探索,对揭示乡村贫困成因规律、提升减贫成效具有重要意义。本文基于分层线性模型和多维贫困数据,从户-村-县三级尺度研究了河南省及其平原、丘陵、山地3种地理环境下农户致贫因素的尺度差异及机理比较。结果表明:①河南省农户致贫因素存在显著的尺度差异特征,农户尺度总体上解释了82.0%的农户致贫方差变异,村和县尺度分别为10.6%和7.4%。平原、丘陵、山地地区农户尺度的致贫方差变异占比分别为85.4%、89.7%和74.7%,村域尺度分别为14.6%、10.3%和25.3%,表明不同地理环境下农户的主要致贫因素均聚集在农户尺度,村级尺度对农户致贫也有一定的作用,而县级尺度因素影响相对较小。②不同地理环境下的农户致贫因素显著不同。未成年抚养负担、种植业收入占比高和转移性收入依赖是贫困农户的主要致贫因素,其中平原地区的直接致贫因素是较高医疗支出及未成年人抚养负担,而种植业收入依赖是丘陵和山地地区的关键致贫因素。③县域地形地貌条件及涉农投资是农户致贫的宏观背景,传统农业种植收入依赖及较重的家庭负担是农户致贫的个体因素,村平均高程及人均耕地规模加剧了个体因素的致贫作用。区域减贫政策制定不但要强调县域尺度的区域差异性,更须重视农户及村域尺度的微观特征,发挥农户脱贫主体地位,完善农户需求导向的减贫政策体系,提升减贫政策实施成效。  相似文献   

13.
Business integration is an important determinant of business value and firm performance which enables a firm to respond to pressing competitive forces. Given its significant role, business integration in general has been an enduring research topic over the years. However, due to its complex nature, the ways to achieve this important organisational capability in firms are still not clearly understood. Hence, the present study is an attempt to ‘open this black box’ and examine the relevant issues through a case study of M.com, one of the largest e-commerce firms in China. The findings of this case study emphasise that the ability to coordinate organisational interdependencies and asset orchestration according to the needs of business processes is challenging but necessary in order to achieve business integration in e-commerce firms. It is found that asset orchestration in a firm is contingent on the organisational interdependencies such that different interdependence types demand different coordination methods at the very least. It also shows the significant role of IT in asset orchestration and the coordination of organisational interdependencies during business integration. With these capabilities, firms can experience growth and improve the quality of conformance to customer needs.  相似文献   

14.
由于制冷剂较高的臭氧层消耗潜势和气候变化影响,政府和公众对于制冷剂的重视程度正不断加深.《蒙特利尔议定书》虽从源头上限制了臭氧消耗类物质(ODS)的生产和使用,却忽略了ODS的产品生命周期过程中潜在的释放风险.基于物质流分析方法,本文构建了中国澳门特别行政区(以下简称澳门特区)家用空调制冷剂的动态分析框架,并从生命周期...  相似文献   

15.
This paper advances a friendly critique of the national systems of innovation approach and offers some suggestions for its future development. I argue that the approach has difficulty accounting for bounded change in national systems. I review three recent changes in the U.S. innovation system - the Internet boom and bust of the late 1990s and early 2000s, the response to the terrorist attacks of September 11, 2001, and the acceleration of productivity growth since the mid-1990s - in order to assess the strengths and weaknesses of the framework in this respect. Future research might be enriched, at least in the case of large national innovation systems, by absorbing concepts developed in other strands of institutionalist literature, such as “intercurrence” and “embeddedness”.  相似文献   

16.
Serum beta-glucuronidase activity was estimated by our modified method using two substrates phenolphthalein glucuronide and p-nitrophenyl glucoronide in 49 healthy subjects and 94 patients with gastrointestinal tract (GIT) carcinoma. The correlation coefficient using the two substrates was found to be r=0.8383. The method of Gabor Szasz was modified wherein the incubation time was decreased from 5 hours to 2 hours and the incubation temperature was increased from 25°C to 37°C. The increase in beta-glucuronidase activity in GIT carcinoma appears to be a good biochemical marker in patients with such type of carcinomas, a finding not reported in literature to-date. The modified quantitative method used for estimation of beta-glucuronidase is reliable, accurate, simple and rapid.  相似文献   

17.
王昌海  温亚利  郝春旭  时鉴 《资源科学》2010,32(10):2028-2035
基于陕西长青大熊猫自然保护区周边124退耕户实地调研有效问卷,探讨了该区退耕户退耕意愿及其影响因素。并利用Logistic模型研究了各相关因素对退耕户参与退耕意愿的具体影响。结果表明:农户愿意后续退耕的比例略高于不愿意继续退耕的比例,其中经济相对发达地区的农户退耕意愿高于经济相对欠发达地区;而在影响农户后续退耕意愿的诸因素中,退耕补贴所占收入比重、经济林的预期经济收益、后续技术指导以及农户的环保意识对退耕农户后续退耕意愿有着比较显著的影响。本研究为进一步巩固前期退耕成果提供借鉴和启示,为完善大熊猫自然保护区的生态补偿机制提供参考。  相似文献   

18.
在浙东新昌地区,新发现了一个由辉绿岩和花岗岩组成的复合岩体.辉绿岩主要由斜长石(An=45~55.50%~60%)、普通辉石(20%~30%)、普通角闪石(10%~15%)等组成,全岩Ar-Ar同位素年龄为109.1±2.8Ma;花岗岩主要由石英(25%~30%),钾长石(50%~60%),斜长石(An=20±,10%~15%)及少量的黑云母(<5%)组成,锆石SHRIMP U-Pb年龄值为129~109Ma,其最小年龄值109Ma与辉绿岩的相同,证明辉绿岩和花岗岩近同时冷凝固结.在岩石地球化学上,它们同属钙碱性岩石系列,具有轻稀土元素和大离子亲石元素富集、高场强元素亏损等特点,稀土元素、微量元素配分型式基本相同,(87Sr/86Sr)I=0.7074~0.7079,εNd(t)=-3.5~-4.4,指示它们的微量元素和同位素发生过充分的交换.这与浙东晚中生代玄武岩-流纹岩复合岩流的相似,也与福建沿海同时代复合火成岩的基本一致.它们是起源于受消减作用影响的岩石圈地幔部分熔融而产生的玄武岩浆底侵,并与深融的壳源花岗岩浆相互作用的结果,是壳幔作用的产物.新昌复合岩体的发现与研究,为研究浙东地区和浙闽沿海的壳幔作用和构造-岩浆作用提供了一个新的实例.  相似文献   

19.
选取陕北沙漠化逆转区榆林作为研究对象,采用气候倾向率、Mann—Kendall非参数检验和小波分析法等气候诊断方法,探讨了1971年-2010年榆林地区气温时空分布规律、变化趋势及其影响因素。结果表明:榆林南北两大地貌单元气温逐年升高,北部增温幅度大于南部,气候倾向率关系为:陕南〈关中〈全国〈南部丘陵沟壑区〈北部风沙草滩区;南部丘陵沟壑区气温突变(1989年)早于北部风沙草滩区(1994年)。气温增加幅度存在差异,空间格局呈现“冷快暖l陧,整体一致增加”的变化特征。榆林地区气温变化完全符合全球变化规律,其驱动力是自然因素和人类活动共同作用的结果,太阳辐射由强到弱,加之LaNina事件频发,在一定程度上减缓了人类活动带来的增温。  相似文献   

20.
Small enterprises play an important role in the technology innovation and economic development of most countries all over the world, particularly in Taiwan. Due to a lack of financial resources and expertise, small enterprises tend to find novel ways to utilize IT resources in order to reduce IT adoption costs, to achieve better flexibility, business agility and scalability, and to react faster to market demands. Whereas Taiwan has been promoting cloud computing to help Taiwanese enterprises adopt more effective information technologies, we found that the service strategies of small cloud service providers are individually differentiated in order to survive in the competitive cloud computing market. This paper reports a case study of a small e-learning service provider and its four clients in Taiwan. Some novel insights are revealed through this case study and recommendations are provided accordingly.  相似文献   

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