科技论文网络研究进展及建立论文相似网络的构想

从复杂网络角度介绍科技论文相关网络的研究进展,包括引用网络和共现网络,在此基础上提出了建立论文内容相似性网络的构想,并探讨其现实意义与关键问题,包括论文内容的完整准确表达、利用向量空间模型表达文献内容、被引强度和耦合率等.     

Depressive mood modulates the anterior lateral CA1 and DG/CA3 during a pattern separation task in cognitively intact individuals: A functional MRI study

Although patients with major depressive disorder typically have a reduced hippocampal volume, particularly in the cornu ammonis 1 (CA1), animal studies suggest that depressive mood is related to the dentate gyrus (DG). In this study, our objective was to clarify which hippocampal subregions are functionally associated with depressive mood in humans. We conducted a functional MRI (fMRI) study on 27 cognitively intact volunteers. Subjects performed a modified version of a delayed matching‐to‐sample task in an MRI scanner to investigate pattern separation‐related activity during each phase of encoding, delay, and retrieval. In each trial, subjects learned a pair of sample cues. Functional MR images were acquired at a high spatial resolution, focusing on the hippocampus. Subjects also completed the Beck Depression Inventory (BDI), a questionnaire about depressive mood. Depending on the similarity between sample cues, activity in the DG/CA3 and medial CA1 in the anterior hippocampus changed only during encoding. Furthermore, the DG/CA3 region was more active during successful encoding trials compared to false trials. Activity in the DG/CA3 and lateral CA1 was negatively correlated with BDI scores. These results suggest that the DG/CA3 is the core region for pattern separation during the encoding phase and interacts with the medial CA1, depending on the similarity of the stimuli, to achieve effective encoding. Impaired activity in the DG/CA3, as well as in the lateral CA1, was found to be associated with depressive symptoms, even at a subclinical level. © 2013 Wiley Periodicals, Inc.     

Interactive computer-aided diagnosis of breast masses: computerized selection of visually similar image sets from a reference library

RATIONALE AND OBJECTIVES: The clinical utility of interactive computer-aided diagnosis (ICAD) systems depends on clinical relevance and visual similarity between the queried breast lesions and the ICAD-selected reference regions. The objective of this study is to develop and test a new ICAD scheme that aims improve visual similarity of ICAD-selected reference regions. MATERIALS AND METHODS: A large and diverse reference library involving 3,000 regions of interests was established. For each queried breast mass lesion by the observer, the ICAD scheme segments the lesion, classifies its boundary spiculation level, and computes 14 image features representing the segmented lesion and its surrounding tissue background. A conditioned k-nearest neighbor algorithm is applied to select a set of the 25 most "similar" lesions from the reference library. After computing the mutual information between the queried lesion and each of these initially selected 25 lesions, the scheme displays the six reference lesions with the highest mutual information scores. To evaluate the automated selection process of the six "visually similar" lesions to the queried lesion, we conducted a two-alternative forced-choice observer preference study using 85 queried mass lesions. Two sets of reference lesions selected by one new automated ICAD scheme and the other previously reported scheme using a subjective rating method were randomly displayed on the left and right side of the queried lesion. Nine observers were asked to decide for each of the 85 queried lesions which one of the two reference sets was "more visually similar" to the queried lesion. RESULTS: In classification of mass boundary spiculation levels, the overall agreement rate between the automated scheme and an observer is 58.8% (Kappa = 0.31). In observer preference study, the nine observers preferred on average the reference lesion sets selected by the automated scheme as being more visually similar than the set selected by the subjective rating approach in 53.2% of the queried lesions. The results were not significantly different for the two methods (P = .128). CONCLUSIONS: This study suggests that using the new automated ICAD scheme, the interobserver variability related issues can thus be avoided. Furthermore, the new scheme maintains the similar performance level as the previous scheme using the subjective rating method that can select reference sets that are significantly more visually similar (P < .05) than when using traditional ICAD schemes in which the mass boundary spiculation levels are not accurately detected and quantified.     

白桦总三萜类成分高效液相色谱指纹图谱研究

目的建立白桦总三萜类成分的HPLC指纹图谱分析方法,研究不同采收期白桦药材的质量。方法以Kromasil C18柱（4.6mm×250mm,5μm）为色谱柱,流动相乙腈-水,采用梯度洗脱,流速为1.0ml/min,柱温25℃,检测波长280nm;进样量20μl;检测时间60min,对10批白桦总三萜类成分的HPLC指纹图谱进行研究,并运用相似度评价法对数据进行分析。结果实验标定9个共有峰,不同采收期的白桦指纹图谱相似度较好。结论该方法准确可靠,重复性好,用于白桦的质量评价切实可行;不同采收期白桦总三萜类化学组成相似,其相对比例较稳定。     

仙灵骨葆胶囊中丹参酮Ⅱ_A溶出度测定方法研究

目的:建立仙灵骨葆胶囊中丹参酮ⅡA的体外溶出测定方法,对新型仙灵骨葆胶囊与仙灵骨葆胶囊中丹参酮ⅡA的溶出情况进行比较。方法:采用小杯法,转速100 r.m in-1,以6种不同溶液为溶出介质,HPLC法测定仙灵骨葆胶囊中丹参酮ⅡA在不同溶出介质中的体外溶出度,计算累积溶出百分率,采用相似因子(f2)进行释放曲线的相似性比较,对溶出曲线进行多种数学模型拟合,计算溶出参数。结果:以pH 7.6的磷酸盐缓冲液+4.0%胆酸作为仙灵骨葆胶囊中丹参酮ⅡA的溶出介质时,累积溶出百分率最高;新型仙灵骨葆胶囊与仙灵骨葆胶囊中丹参酮ⅡA的溶出曲线相似因子f2小于50。结论:不同工艺制备的仙灵骨葆胶囊丹参酮ⅡA的溶出度差异较大。新型仙灵骨葆胶囊丹参酮ⅡA的溶出速度快,累积溶出百分率高。     

低阻抗意念导入疗法与催眠疗法的异同点分析

低阻抗意念导入疗法要求患者处于低阻抗状态时进行治疗,而低阻抗状态是指从清醒到睡眠这个过程的某种中间状态,这与催眠状态存在相似之处.为了更好地区分低阻抗意念导入疗法与催眠疗法,将对两者的异同点进行分析,以便读者更好地对低阻抗意念导入疗法进行把握.     

双鱼颗粒挥发性成分指纹图谱和定量分析

目的建立双鱼颗粒挥发性成分指纹图谱及定量测定方法。方法 Agilent DB-1毛细管柱(30 m×0.32 mm,0.25μm);进样量为1μL;分流比为25∶1;进样口温度为230℃;以氮气为载气,体积流量0.6 mL/min;FID检测器温度为250℃;程序升温。结果建立的指纹图谱分离度和重复性良好,确定12个共有峰,各批次样品相似度在0.95以上;采用GC/MS对色谱峰进行定性分析,其中7个成分经对照品比对,分别为桉油精(峰2)、樟脑(峰3)、薄荷酮(峰4)、龙脑(峰5)、薄荷脑(峰6)、(+)-胡薄荷酮(峰9)、甲基正壬酮(峰10),其中1、10、11、12号峰主要来自于鱼腥草,2、5号峰主要来自于艾叶和薄荷,3号峰主要来自于艾叶,4、6、8、9号峰主要来自于薄荷,7号峰主要来自于艾叶、薄荷和鱼腥草。并对其中桉油精、薄荷脑进行定量分析,平均回收率分别为103.9%和98.2%,RSD分别为2.1%和2.3%。10批次样品中桉油精为0.17～0.23mg/g,薄荷脑为0.45～0.67mg/g。结论建立的双鱼颗粒指纹图谱和2个指标成分定量分析方法,快速、简便、准确,能有效评价该制剂的质量。     

牛膝指纹图谱分析

目的:对不同产地牛膝药材、同一产地不同规格牛膝药材的HPLC指纹图谱进行研究,比较不同产地牛膝药材、同一产地不同规格牛膝药材的HPLC指纹图谱差异,探讨产地、规格对牛膝药材质量的影响及规格与牛膝药材内部质量的联系;为牛膝药材的产地鉴别提供理论依据;为牛膝药材质量标准制定、规格完善及临床用药提供参考。方法:采用超声提取法制备样品,通过HPLC法采集不同产地牛膝药材、同一产地不同规格牛膝药材的指纹图谱,运用相似度、聚类分析、主成分分析的方法进行分析,并比较不同产地牛膝药材、不同规格牛膝药材的HPLC指纹图谱差异。结果:不同产地分析,主成分分析能将5个产地牛膝药材区分开,且产地鉴别结果优于聚类分析和相似度分析。不同规格分析,相似度和主成分分析均不能将不同规格牛膝药材区分开。结论:不同产地牛膝药材化学成分种类、峰高差异显著;不同规格牛膝药材化学成分种类、峰高差异较小;主成分分析可用于牛膝药材的产地鉴别。     

玫瑰花口服液的红外指纹图谱及化学模式识别

目的:采用红外光谱和化学模式识别相结合建立了玫瑰花口服液质量评价的方法。方法:以11批玫瑰花口服液和4种伪品作红外光谱分析,对主要吸收峰进行指认,获得红外指纹图谱,并按不同特征吸收峰位下的透射比进行相似度计算,通过相似度分析对11批玫瑰花口服液及4种伪品的红外图谱一致性进行了考察,并把获得的指纹图谱采用系统聚类分析和主成分分析进行化学模式识别。结果:11批玫瑰花口服液红外指纹图谱一致性良好,玫瑰花口服液及伪品通过相似度分析和化学模式识别均能够很好地区分开来,相似度和聚类分析、主成分分析结果相一致,2种化学计量方法具有良好的相关性。结论:结果表明该方法是鉴别玫瑰花口服液真伪的有效方法。