基于C-value与TF-IDF的文献簇主题识别研究

引文分析是科技情报分析的一种重要方法和技术,特别是建立在共耦合和共被引基础上的引文聚类分析逐渐发展成为科技情报分析中最活跃的研究领域之一。引文聚类分析形成一系列由科技文献组成的文献簇,并不能直接体现出文献簇的主题,因此需要识别这些文献簇的内容特征。本文分析了引文分析中文献簇主题识别的典型方法及局限,提出了结合C-value和TF-IDF算法的文献簇主题识别方法。实验表明,该方法可以充分地利用C-value和TF-IDF算法的优点,对C-value和TF-IDF算法中不合理的地方予以了改进,从而可以更好地应用于引文分析中文献簇的主题识别。

The value of vegetation ecosystem services:a case of Qinling-Daba Mountains

According to differences in vegetation types and their coverage, combining the latest research, using theory and method on the value of vegetation ecosystem services, this paper not only calculated goods produced by different types of vegetation but also estimated the value of various vegetation ecosystem services and set up database, GIS and eco-account of vegetation ecosystem. The result was as follows: the value of vegetation's primary productivity, soil and fertility conservation, water conservation, CO 2 fixation and O 2 release was 199.6 billion yuan/a, 22.64 billion yuan/a, 22.66 billion yuan/a, 352.24 billion yuan/a and 374.19 billion yuan/a, respectively. The total value of ecosystem services was 968.33 billion yuan/a. The temperate deciduous broad-leaved forest had the highest contribution rate, accounting for 16.42%. The result of value can reflect regional reality more exactly.

Hepatitis C virus cure with direct acting antivirals: Clinical,economic, societal and patient value for China

About 10 million people in China are infected with hepatitis C virus(HCV),with the seroprevalence of anti-HCV in the general population estimated at 0.6%.Delaying effective treatment of chronic hepatitis C(CHC)is associated with liver disease progression,cirrhosis,hepatocellular carcinoma,and liver-related mortality.The extrahepatic manifestations of CHC further add to the disease burden of patients.Managing CHC-related advanced liver diseases and systemic manifestations are costly for both the healthcare system and society.Loss of work productivity due to reduced well-being and quality of life in CHC patients further compounds the economic burden of the disease.Traditionally,pegylatedinterferon plus ribavirin(PR)was the standard of care.However,a substantial number of patients are ineligible for PR treatment,and only 40%–75%achieved sustained virologic response.Furthermore,PR is associated with impairment of patient-reported outcomes(PROs),high rates of adverse events,and poor adherence.With the advent of direct acting antivirals(DAAs),the treatment of CHC patients has been revolutionized.DAAs have broader eligible patient populations,higher efficacy,better PRO profiles,fewer adverse events,and better adherence rates,thereby making it possible to cure a large proportion of all CHC patients.This article aims to provide a comprehensive evaluation on the value of effective,curative hepatitis C treatment from the clinical,economic,societal,and patient experience perspectives,with a focus on recent data from China,supplemented with other Asian and international experiences where China data are not available.

Diagnostic value of interleukin-8 in colorectal cancer:A case-control study and meta-analysis

AIM:To assess the diagnostic value of serum interleukin-8(IL-8)in the detection of colorectal cancer(CRC).METHODS:An original study was conducted to explore the potential value of IL-8 in CRC diagnosis.Receiver operating characteristic(ROC)analysis was performed and the area under the curve(AUC)value was calculated.PUBMED and EMBASE were searched(to October,2013),supplemented with manual screening for relevant publications.Meta-analysis methods were applied to pool sensitivity,specificity,positive and negative likelihood ratios,and diagnostic odds ratios and to construct a summary receiver-operating characteristic(s ROC)curve.Heterogeneity across studies was checked by the I2 test and Deek’s funnel plot method was applied to test publication bias.RESULTS:In our original study,serum IL-8 yielded an AUC of 0.742[95%CI:0.635-0.849].The sensitivity and specificity were 85.42%and 54.05%,respectively,at a cut-off value of 5.39.In this meta-analysis,we included five studies with 668 CRC patients and 374controls and one study in our own center with 48 CRC patients and 37 controls.The pooled sensitivity and specificity of IL-8 were 0.69(95%CI:0.42-0.87)and0.85(95%CI:0.68-0.94)for CRC detection.Besides,the area under the s ROC curve was 0.86(95%CI:0.82-0.88).Subgroup analysis suggested that there was no heterogeneity in the Asian subgroup but some in the European subgroup.In addition,no publication bias was found according to the Deek’s funnel plot asymmetry test.CONCLUSION:Serum IL-8 is a promising biomarker for CRC detection and may become a clinically useful tool to identify high-risk patients.

Prognostic value of interim ^(18)F-FDG PET/CT in diffuse large B-cell lymphoma

Objective： Diffuse large B-cell lymphoma （DLBCL） is a heterogeneous disease. The prognostic factor currently used is not accurate enough to predict the outcomes of patients with DLBCL. The prognostic significance of interim PET/CT in DLBCL remains controversial. The aim of this study is to determine the predictive value of interim 18F-FDG PET/CT after first-line treatment in patients with DLBCL. Methods： Thirty-two patients with DLBCL underwent baseline, interim and post-treatment lSF-FDG PET/CT scans. Imaging results were analyzed for the survival of patients via software SPSS 13.0, retrospectively. Results： Thirty-one of the 32 patients were treated with R-CHOP regimen, and interim 18F-FDG PET/CT of 24 patients was performed after 2 cycles of treatment. After a median follow-up period of 16.7 months, the 2-year progression-free survival （PFS） rates were significantly different between the groups above and below SUVmax CUt-Off value of 2.5 （P=0.039）. No significant differences were found in the 2-year PFS rates if SUVm, cut-offvalues were set as 2.0 and 3.0, respectively （P=0.360; P=0.113）. Conclusions： Interim PET/CT could predict the prognosis of DLBCL patients with the SUVmax cut-off value of 2.5, but more clinical data should be concluded to confirm this conclusion.

The Asymptotic Property of Generalized Taylor Remainder "Mean Value Point"

This paper discussed asymptotic property of Taylor remainder 'mean value point' in normed Linear space. The asymptotic progerty of 'mean value point' is solved when f^(n+i)(x0)h^(n+i)=0(i=1,2,……,p-1) and f^(n+p)(x0)h^(h+p) don't exist. Meanwhile, achicve more general asymptotic estimation formula. Make many former results are just because of special case of the pager.

EKELAND'S PRINCIPLE FOR SET-VALUED VECTOR EQUILIBRIUM PROBLEMS

In this paper, we introduce a concept of quasi C-lower semicontinuity for setvalued mapping and provide a vector version of Ekeland＇s theorem related to set-valued vector equilibrium problems. As applications, we derive an existence theorem of weakly efficient solution for set-valued vector equilibrium problems without the assumption of convexity of the constraint set and the assumptions of convexity and monotonicity of the set-valued mapping. We also obtain an existence theorem of ε-approximate solution for set-valued vector equilibrium problems without the assumptions of compactness and convexity of the constraint set.

基于领域类别信息C-value的多词串自动抽取

该本的多词串抽取是自然语言处理领域一项重要的研究内容。该文提出了一种多类别C-value(Multi-Class C-value)方法,利用多词串在不同领域的分布信息改善领域相关的多词串抽取的性能。在汽车、科技和旅行三个领域的数据上进行实验,评价多词串的准确率,在top-100级别上,较传统的C-value方法在三个领域中分别提高了12、12和13个百分点。实验结果验证了方法的有效性。

Foliar δ^13C Values and Water Use Efficiency ofSemi-arid Plants in Horqin Sandy Land, China

Water was a key factor restricting the plantation in sandy areas. Foliar δ^(13)C value regarded as an indicator of longterm water use efficiency(WUE) of plants was generally used to evaluate the adaptability of plants to arid and semi-arid environment. In Horqin sandy land of China, the foliar δ^(13)C values of 114 species in 35 families naturally growing in the area, and 15 species of sand-fixing trees and shrubs were measured and analyzed in 2012. The results showed that 97 species in all 114 species were C_3 plants and only 17 species were C_4 plants. Most C_4 plants belonged to Gramineae family. The foliar δ^(13)C value of C_3 plants was between -25.000 and -31.075‰ with an average of-28.226‰, while those of C_4 plants between -12.578 and -16.334‰, with an average of -13.678‰. The δ^(13)C values of mature leaves collected in August were averagely 0.85‰ less than that of juvenile leaves collected in June. The foliar δ^(13)C values and WUE of 15 sand-fixing tree species in Horqin sandy land ranked in the order as: S.vulgaris >H.rhamnoides >C.ovata >P.mongolica >T.chinensis >R.typhina >S.matsudana >E.angustifolia >U.pumila >S.gordejevii >X.sorbifolia >C.microphylla >H.fruticosum >C.korshinskii >E.bungeanus.

STRUCTURES OF VALUES FOR SET GAMES RESTRICTED BY PARTITION SYSTEM

A set game, in which the worth of a coalition is expressed by a set instead of a real number, is a new type of cooperative game. A F-restricted set game is a set game restricted by partition system. The main theorems show the structures of IM-value,OIM-value,SCM-value and ICM-value respectively,and the equivalency of IM value and the OIM-value for monotonic set games restricted by partition system as well.

Seismicity Factor A-Value and Its Application to Mid-Term Earthquake Prediction in North China

The seismicity factor A-value is defined by synthesizing the seismicity precursors in time, space and magnitude in this paper. The seismicity data of moderate or small earthquakes during 1972 ~ 1996 in North China are used to perform spacial scanning of seismicity factor A-value. The result shows that there are obviously anomaly zones of A-value with better prediction effect in the mid-term of 2~3 years before most moderately strong earthquakes. Some problems regarding the mid-term prediction using A-value have been discussed.

Application Value of Vitamin C in the Treatment of Sepsis

Objective:To analyze the effect and value of vitamin C in the treatment of sepsis.Methods:Forty-four patients with sepsis treated in our hospital from June 2019 to June 2021 were investigated.The above subjects were divided into conventional group and research group,each with 22 cases,using the method of drawing lots.Routine treatment was applied in the conventional group,and the patients of the research group were treated with vitamin C on the basis of the routine method.The effective rate after treatment and the score of liver and kidney function in patients with sepsis were compared between the two groups.Results:The total effective rate(95.45%)of the research group with increased vitamin C in the treatment of sepsis was much higher than that of the conventional group(72.72%),and the scores of liver function and renal function in the research group were much higher than those in the conventional group at different times(P<0.05).Conclusion:Vitamin C has a good effect in the treatment of sepsis.It not only greatly reduces the mortality of sepsis patients,but also effectively improves the liver function and renal function of sepsis patients.It is of high application value.It is recommended to be popularized for applications.

Poetic Justice: Novel Reading and the Perfection of Human Public Value

Taking novels as the breakthrough point,the American thinker,Martha C.Nussbaum,strongly criticizes the materialization of human beings by economic utilitarianism and legal economics,as well as the estrangement and indifference between human beings in the book Poetic Justice:The Literary Imagination and Public Life.Through being read,the novels enter into the field of public life,expand the area of human emotion,preach human justice and promote the perfection of human values.

A REGULAR VALUE OF COMPACT DEFORMATION

Sufficient conditions were given to assert that between any two Banach spaces over K, Fredholm mappings share at least one .value in a specific open ball. The proof of the result is constructive and based upon continuation methods.

ALGORITHMS FOR A SYSTEM OF GENERALIZED MIXED EQUILIBRIUM PROBLEMS AND A COUNTABLE FAMILY OF SOME NONLINEAR MULTI-VALUED NONEXPANSIVE-TYPE MAPS

In this paper, relaxed iterative algorithms of Krasnoselskii-type and Halpern-type that approximate a solution of a system of a generalized mixed equilibrium problem anda common fixed point of a countable family of totally quasi-C-asymptotically nonexpansivemulti-valued maps are constructed. Strong convergence of the sequence generated by thesealgorithms is proved in uniformly smooth and strictly convex real Banach spaces with Kadec-Klee property. Furthermore, several applications of our theorems are also presented. Finally,our theorems are significant improvements on several important recent results for this classof nonlinear problems.

D-二聚体与C反应蛋白对Stanford A型主动脉夹层动脉瘤患者术后远期预后的预测价值

目的分析D-二聚体(D-D)与C反应蛋白(CRP)在Stanford A型主动脉夹层动脉瘤(ADA)患者术后远期预后中的预测价值。方法选取76例胸痛患者为研究对象,所有患者均行心脏超声或主动脉CT血管成像检查,将45例Stanford A型ADA患者纳入观察组,均行手术治疗;非Stanford A型ADA的31例患者纳入对照组。对比2组发生胸痛72 h内的D-D与CRP水平。术后对观察组随访3年,按临床结局分成死亡组(n=10)与存活组(n=35),对比2组D-D与CRP水平;另绘制受试者工作曲线(ROC),分析D-D、CRP单独与联合预测Stanford A型ADA患者的远期预后临床价值。结果观察组的D-D[(1.31±0.35)mg/L]与CRP[(16.59±2.34)mg/L]水平高于对照组[(0.68±0.13)mg/L、(7.53±1.26)mg/L],差异有统计学意义(P<0.05);ADA患者中死亡组的D-D[(1.78±0.49)mg/L]与CRP[(30.46±4.77)mg/L]水平高于存活组[(1.03±0.26)mg/L、(13.59±2.36)mg/L],差异有统计学意义(P<0.05)。ROC结果显示,D-D与CRP联合检测预测Stanford A型ADA患者远期预后的曲线下面积(AUC)[0.909(95%CI:0.823~0.994)]高于D-D与CRP单独预测[0.806(95%CI:0.680~0.931)、0.840(95%CI:0.727~0.953)]。结论Stanford A型ADA患者血清内的D-D与CRP水平呈高表达,且表达水平越高,患者预后越差,两项指标联合可有效预测患者的远期预后,临床应用价值较高。

Return Value VS.Exception

处理C++程序中的非正常情况时,return value和exception是两种常见的工具。本文对这两种工具的差异做了一个比较。

^(18)F-FDG PET/CT代谢参数联合临床病理特征对晚期结直肠癌患者KRAS基因突变的评估价值

目的探讨^(18)F-氟代脱氧葡萄糖(^(18)F-FDG)PET/CT代谢参数联合临床病理特征对晚期结直肠癌患者鼠类肉瘤病毒癌基因(KRAS)基因突变的评估价值。方法回顾性分析64例晚期结直肠癌患者的临床资料。所有患者在治疗前均接受^(18)F-FDG PET/CT检查。分析最大标准化摄取值(SUV_(max))、不同阈值下的代谢肿瘤体积(MTV)和病变总糖酵解(TLG)、临床病理特征与患者KRAS基因突变状态之间的关系。通过多因素Logistic回归模型分析与患者KRAS基因突变相关的因素。采用受试者工作特征曲线分析^(18)F-FDG PET/CT代谢参数、临床病理特征及二者联合评估患者KRAS基因突变的效能。基于^(18)F-FDG PET/CT代谢参数和临床病理特征构建列线图模型。结果单因素和多因素Logistic回归分析结果显示,SUV_(max)≥19.55、MTV50%≥7.95、肿瘤组织中/高分化与患者KRAS基因突变有关。SUV_(max)、MTV50%和肿瘤组织分化程度评估患者KRAS基因突变的曲线下面积(AUC)分别为0.653、0.625和0.621,三者联合评估的AUC为0.800,均高于单个指标的AUC(P<0.05)。基于SUV_(max)、MTV50%和肿瘤组织分化程度构建的列线图模型的一致性指数为0.800,校准曲线与参考线基本拟合。结论^(18)F-FDG PET/CT的代谢参数SUV_(max)、MTV50%与晚期结直肠癌患者KRAS基因突变密切相关,联合肿瘤组织分化程度所构建的列线图模型对患者KRAS基因突变具有较高的评估价值。

^(18)F-FDG PET/CT显像中标准化摄取值测量技术、影响因素及临床应用的研究进展

^(18)F-氟代脱氧葡萄糖(^(18)F-FDG)正电子发射计算机断层/电子计算机断层扫描(PET/CT)显像在临床应用中较为广泛,标准化摄取值(SUV)是重要的半定量指标,对于疾病的早期诊断和鉴别诊断、预测肿瘤治疗的早期响应和疗效监测具有重要意义。该文就^(18)F-FDG PET/CT显像中SUV测量技术、影响因素及临床应用的研究进展作一综述。

基于e^3value的B2C电商商业模式研究——对比分析天猫商城与京东商城

本文基于商业模式价值系统研究视角,采用e^3value可视化研究方法,以天猫商城与京东商城为研究对象,针对进行的价值创造和价值传递途径,对其价值获取方式及其影响因素进行分析。研究发现:天猫商城和京东商城在价值获取上与入驻商家及供应商存在矛盾,需要协调各方关系;在价值传递过程中京东商城有着更加完善合理的传递途径;在价值创造方面B2C电商需要拓展其服务内容,为顾客创造更多的价值。