Breast Self-Examination (BSE): Association between “Belief in BSE” and “Awareness of BSE” among University Female Students in Uganda

Background: Regular breast self-examination (BSE) has been known to effectively detect breast cancer occurrence early. Are Women who consider BSE effective in detecting breast cancer more likely to be aware of BSE, or vice versa? The present study was an attempt to answer this question. Methods: A cross-sectional study was performed for 259 female University students in Kampala, Uganda. Data were analyzed using SPSS. Univariate and bivariate analyses were carried out. Results: The majority (64.1%) were aware of the BSE technique. Women considering BSE to be effective for early cancer detection were significantly more likely to be aware of the BSE technique. Conclusions: University students who believed in the benefits of BSE were more likely to be aware of BSE than those who did not. More emphasis should be placed on health education for women of younger ages to increase the knowledge of the practice of BSE.

Refining safety considerations for intradialytic blood flow restriction exercise. Commentary on “Concerns on the application of blood-flow restriction resistance exercise and thrombosis risk in hemodialysis patients”

I read with great interest the article“Concerns on the application of blood flow restriction resistance exercise and thrombosis risk in hemodialysis patients”by Correa et al.1 The study presents complementary data from a previous randomized controlled trial,2 exploring the application of intradialytic blood flow restriction exercise for hemodialysis patients.

Efficient ECG classification based on Chi-square distance for arrhythmia detection

This study introduces a new classifier tailored to address the limitations inherent in conventional classifiers such as K-nearest neighbor(KNN),random forest(RF),decision tree(DT),and support vector machine(SVM)for arrhythmia detection.The proposed classifier leverages the Chi-square distance as a primary metric,providing a specialized and original approach for precise arrhythmia detection.To optimize feature selection and refine the classifier’s performance,particle swarm optimization(PSO)is integrated with the Chi-square distance as a fitness function.This synergistic integration enhances the classifier’s capabilities,resulting in a substantial improvement in accuracy for arrhythmia detection.Experimental results demonstrate the efficacy of the proposed method,achieving a noteworthy accuracy rate of 98% with PSO,higher than 89% achieved without any previous optimization.The classifier outperforms machine learning(ML)and deep learning(DL)techniques,underscoring its reliability and superiority in the realm of arrhythmia classification.The promising results render it an effective method to support both academic and medical communities,offering an advanced and precise solution for arrhythmia detection in electrocardiogram(ECG)data.

Trustworthy semi-supervised anomaly detection for online‐tooffline logistics business in merchant identification

The rise of online-to-offline(O2O)e-commerce business has brought tremendous opportunities to the logistics industry.In the online-to-offline logistics business,it is essential to detect anomaly merchants with fraudulent shipping behaviours,such as sending other merchants'packages for profit with their low discounts.This can help reduce the financial losses of platforms and ensure a healthy environment.Existing anomaly detection studies have mainly focused on online fraud behaviour detection,such as fraudulent purchase and comment behaviours in e-commerce.However,these methods are not suitable for anomaly merchant detection in logistics due to the more complex online and offline operation of package-sending behaviours and the interpretable requirements of offline deployment in logistics.MultiDet,a semi-supervised multiview fusion-based Anomaly Detection framework in online-to-offline logistics is proposed,which consists of a basic version SemiDet and an attention-enhanced multi-view fusion model.In SemiDet,pair-wise data augmentation is first conducted to promote model robustness and address the challenge of limited labelled anomaly instances.Then,SemiDet calculates the anomaly scoring of each merchant with an auto-encoder framework.Considering the multi-relationships among logistics merchants,a multi-view attention fusion-based anomaly detection network is further designed to capture merchants'mutual influences and improve the anomaly merchant detection performance.A post-hoc perturbation-based interpretation model is designed to output the importance of different views and ensure the trustworthiness of end-to-end anomaly detection.The framework based on an eight-month real-world dataset collected from one of the largest logistics platforms in China is evaluated,involving 6128 merchants and 16 million historical order consignor records in Beijing.Experimental results show that the proposed model outperforms other baselines in both AUC-ROC and AUC-PR metrics.

Triple the steady-state reaction rate by decorating the In_(2)O_(3)surface with SiO_(x)for CO_(2)hydrogenation

Indium oxide(In_(2)O_(3)),as a promising candidate for CO_(2)hydrogenation to C_(1) products,often suffers from sintering and activity decline,closely related to the undesirable structural evolution under reaction conditions.Based on the comprehension of the dynamic evolution,this study presents an efficient strategy to alleviate the agglomeration of In_(2)O_(3)nanoparticles by the surface decoration with highly dispersed silica species(SiO_(x)).Various structural characterizations combined with density functional theory calculations demonstrated that the sintering resulted from the over-reduction,while the enhanced stability originated from the anchoring effect of highly stable In-OSi bonds,which hinders the substantial formation of metallic In(In^(0))and the subsequent agglomeration.0.6Si/In_(2)O_(3)exhibited CO_(2)conversion rate of10.0 mmol g^(-1)h^(-1)at steady state vs.3.5 mmol g^(-1)h^(-1)on In_(2)O_(3)in CO_(2)hydrogenation.Enhanced steady-state activity was also achieved on Pd-modified catalysts.Compared to the traditional Pd/In_(2)O_(3)catalyst,the methanol production rate of Pd catalyst supported on 0.6Si/In_(2)O_(3)was enhanced by 23%,showing the potential of In_(2)O_(3)modified by SiO_(x)in serving as a platform material.This work provides a promising method to design new In_(2)O_(3)-based catalysts with improved activity and stability in CO_(2)hydrogenation.

Web GIS-Based Temporal Analysis of Climatic Factors Impacting Heat Stroke in Karachi

This study focuses on the impact of climate change, specifically the increasing threat of heatwaves, in Pakistan, with a particular emphasis on the city of Karachi. The Pakistan Meteorological Department (PMD) analysed a century of climatic data to reveal warming trends, attributing them to human-induced factors. The vulnerability of Pakistan to climate change is highlighted, given its warm climate and location in a region where temperature increases are expected to surpass global averages. The study examines the past three decades, noting a significant rise in the frequency of hot days, especially in Karachi, where heatwaves have become more prevalent. The aims and objectives of the study involve identifying temporal changes in temperature, rainfall, humidity, and wind speed from 1984 to 2014 in Karachi. The literature review emphasizes the health implications of heatwaves, citing increased mortality during such events globally. The study incorporates a comprehensive temporal analysis, addressing gaps in previous research by considering multiple climate indicators responsible for heatwaves. The methodology involves statistical analyses, including linear regression and Pearson correlation, applied to temperature data and urbanization parameters. Results indicate an increasing trend in heat index temperature, with heatwave vulnerability peaking in the last three decades. Heat Index Temperature Anomalies show a clear surge, emphasizing the need for new indices to control critical heat stress conditions. The study concludes that tropical climate variability, particularly heat index, is linked to extreme hot days, urging measures to reduce population vulnerability. The findings underscore the importance of policy strategies, such as integrated coastal zone management, to mitigate the adverse health effects of heatwaves in Karachi’s vulnerable population.

Clinical profile and outcomes in very elderly patients with atrial fibrillation anticoagulated with rivaroxaban: data from the EMIR study

Objectives To analyze the clinical profile,adequacy of treatment with rivaroxaban and outcomes in octogenarians with atrial fibrillation(AF),taking rivaroxaban in clinical practice.Methods Observational and non-interventional study that included AF adults recruited from 79 Spanish centers,anticoagulated with rivaroxaban ≥ 6 months before being included.Data were analyzed according to age(≥ 80 vs.< 80 years) at baseline.Results Out of 1433 patients,453(31.6%) were octogenarians at baseline.Compared to younger patients,octogenarians had more comorbidities,higher CHA2DS2-VASc(4.5 ± 1.3 vs.3.0 ± 1.4;P < 0.001) and HAS-BLED scores(2.0 ± 1.0 vs.1.4 ± 1.0;P < 0.001).Overall,the dose of rivaroxaban was adequately prescribed in 83.4% of patients,but more frequently in the younger population(71.1% vs.89.1%;P = 0.039).After a mean follow-up of 2.2 ± 0.6 years,annual rates of stroke + systemic embolism + transient ischemic attack,MACE,cardiovascular death and major bleeding were 1.03%,1.24%,1.03% and 1.75%,respectively,in octogenarian patients.Except for progressive heart failure death and major bleeding,rates of outcomes in octogenarians were similar compared to younger patients.In octogenarians,the concomitant use of antiplatelet agents and non-severe dementia were independently associated with the development of ischemic stroke,whereas previous coronary revascularization and heart failure with MACE,and higher HAS-BLED score with major bleeding.Conclusions In clinical practice,around one third of patients taking rivaroxaban are octogenarians.These patients have many comorbidities and a high thromboembolic risk.Despite that,rates of adverse events remain low.Rivaroxaban is adequately prescribed in the majority of octogenarians.

“Lifting More” is Associated with Lower Risks of Depression in University Students

Research on the population in western world showed that,MSE(muscle-strengthening exercise)is beneficial to the treatment of mental disorders.However,the situation in Chinese adults is little known.For this reason,the study is performed to understand the connection between depression and MSE among college and university students in China aged between 18 to 24.1793 college students have been recruited,and their average age is 20.67.A questionnaire has been developed and it is self-reported and designed to collect information about MSE and participants,including body mass index and sex and so on.Sleep and physical activity have been evaluated by introducing two scales,that is,Pittsburgh Sleep Quality Index and International Physical Activity Questionnaire-Short Form,respectively.Moreover,Patient Health Questionnaire-9 has been adopted to indicate the severity of depression of participants.The link between depression and MSE has been studied by introducing multilevel linear regression.Among all these study participants,just 24.87%of them met the MSE standards of World Health Organization,that is,more than 2 days every week.The average depression score was 6.80(±5.19).Greater num-ber of days for MSE shows negative association with the depression,with (beta=-0.17,95%CI:-0.31 to-0.03,p=0.015).Those students failing to meet MSE standards are more susceptible to the depression risk(beta=0.63,95%CI:0.09–0.19,p=0.027).The results show that,there is a relationship between MSE participation and relieved status of depression among young adults in China.Interventions designed to relieve depression can be developed on the basis of MSE.

Sports compression garments improve resting markers of venous return and muscle blood flow in male basketball players

Background:The benefits associated with sports compression garments are thought to be closely related to enhanced blood flow.However,findings are equivocal,possibly due to heterogeneity in the techniques used for measuring blood flow,the garment types used,and the pressures applied.This study combined Doppler ultrasound and near-infrared spectroscopy technologies to provide the first comprehensive assessment of the effects of 3 sports compression garment types on markers of venous return and muscle blood flow at rest.Methods:Resting lower-limb blood flow measures(markers of venous return,muscle blood flow,and muscle oxygenation)of 22 elite,junior,male basketball players(age=17.2±0.9 years,mean±SD)were assessed in 4 separate conditions:no compression(CON),compression tights(TIGHTS),compression shorts(SHORTS),and compression socks(SOCKS).Markers of venous return(cross-sectional area,time-averaged mean and peak blood flow velocity,and venous blood flow)were measured via Doppler ultrasound at the popliteal and common femoral veins.Muscle blood flow and muscle oxygenation were measured in the gastrocnemius medialis and vastus lateralis using near-infrared spectroscopy.Results:Popliteal markers of venous return were higher in TIGHTS compared to CON(p<0.01)and SHORTS(p<0.01),with SOCKS values higher compared with CON(p<0.05).Common femoral vein markers of venous return were higher for all conditions compared to CON(p<0.05),with TIGHTS values also higher compared to SOCKS(p<0.05).Gastrocnemius medialis blood flow was higher for TIGHTS compared to CON(p=0.000),SOCKS(p=0.012),and SHORTS(p=0.000),with SOCKS higher compared to SHORTS(p=0.046).Vastus lateralis blood flow was higher for TIGHTS compared to CON(p=0.028)and SOCKS(p=0.019),with SHORTS also higher compared to CON(p=0.012)and SOCKS(p=0.005).Gastrocnemius medialis oxygenation was higher for TIGHTS compared to CON(p=0.003),SOCKS(p=0.033),and SHORTS(p=0.003),with SOCKS higher compared to CON(p=0.044)and SHORTS(p=0.032).Vastus lateralis oxygenation was higher for TIGHTS compared to CON(p=0.020)and SOCKS(p=0.006).Conclusion:Markers of venous return,muscle blood flow,and muscle oxygenation are increased with sports compression garments.TIGHTS are most effective,potentially because of the larger body area compressed.

Associations between meeting 24-hour movement guidelines and quality of life among children and adolescents with autism spectrum disorder

Background:The Canadian 24-hour movement behavior(24-HMB)guidelines suggest that a limited amount of screen time use,an adequate level of physical activity(PA),and sufficient sleep duration are beneficial for ensuring and optimizing the health and quality of life(QoL)of children and adolescents.However,this topic has yet to be examined for children and adolescents with autism spectrum disorder(ASD)specifically.The aim of this cross-sectional observational study was to examine the associations between meeting 24-HMB guidelines and several QoLrelated indicators among a national sample of American children and adolescents with ASD.Methods:Data were taken from the 2020 U.S.National Survey of Children’s Health dataset.Participants(n=956)aged 617 years and currently diagnosed with ASD were included.The exposure of interest was adherence to the 24-HMB guidelines.Outcomes were QoL indicators,including learning interest/curiosity,repeating grades,adaptive ability,victimization by bullying,and behavioral problems.Categorical variables were described with unweighted sample counts and weighted percentages.Age,sex,race,preterm birth status,medication,behavioral treatment,household poverty level,and the educational level of the primary caregivers were included as covariates.Odds ratio(OR)and 95%confidence interval(95%CI)were used to present the strength of association between adherence to 24-HMB guidelines and QoL-related indicators.Results:Overall,452 participants(45.34%)met 1 of the 3 recommendations,216(22.65%)met 2 recommendations,whereas only 39 participants(5.04%)met all 3 recommendations.Compared with meeting none of the recommendations,meeting both sleep duration and PA recommendations(OR=3.92,95%CI:1.639.48,p<0.001)or all 3 recommendations(OR=2.11,95%CI:1.034.35,p=0.04)was associated with higher odds of showing learning interest/curiosity.Meeting both screen time and PA recommendations(OR=0.15,95%CI:0.040.61,p<0.05)or both sleep duration and PA recommendations(OR=0.24,95%CI:0.070.87,p<0.05)was associated with lower odds of repeating any grades.With respect to adaptive ability,participants who met only the PA recommendation of the 24-HMB were less likely to have difficulties dressing or bathing(OR=0.11,95%CI:0.020.66,p<0.05)than those who did not.For participants who met all 3 recommendations(OR=0.38,95%CI:0.150.99,p=0.05),the odds of being victimized by bullying was lower.Participants who adhered to both sleep duration and PA recommendations were less likely to present with severe behavioral problems(OR=0.17,95%CI:0.040.71,p<0.05)than those who did not meet those guidelines.Conclusion:Significant associations were found between adhering to 24-HMB guidelines and selected QoL indicators.These findings highlight the importance of maintaining a healthy lifestyle as a key factor in promoting and preserving the QoL of children with ASD.

Numerical analysis of the effects of vesicle distribution characteristics on the engineering properties of volcanic rocks

Vesicles can be of different sizes and shapes and can be randomly distributed within vesicular volcanic rocks. This study investigates the variation of engineering properties of vesicular rocks due to the changes in vesicle distribution characteristics for different cases of bulk porosity and vesicle diameter using a systematic numerical simulation program using the finite element method-based rock failure process analysis (RFPA) software. Models with uniform-size vesicles and combinations of different proportions of different-sized vesicles were considered to resemble natural vesicular rocks more closely, and ten different random vesicle distributions were tested for each case. Increasing bulk porosity decreased the uniaxial compressive strength (UCS) and elastic modulus of the specimens, and the specimens with the lowest bulk porosity showed the greatest range of UCS values in the case of uniform-size vesicles. The effect of vesicle diameter on UCS showed an unsystematic response which was understood to be a result of different vesicle distribution patterns, some of which facilitated a shear failure. Specimens with multiple-size vesicles in different proportions revealed that the variation of UCS due to vesicle distribution characteristics is minimum when the bulk porosity is equally shared by different size vesicles. In addition, when the proportion of smaller-sized vesicles is higher, UCS showed an increase compared to that of the equal proportion of different size vesicles case at low porosities, but a decrease at higher porosities. Variation of elastic modulus showed minor, unsystematic fluctuations as a function of vesicle diameter and different proportions of different-sized vesicles, and the range for different vesicle distribution patterns was narrow in general. Overall, the findings of this study recommend cautious use of the engineering properties determined through a limited number of laboratory tests on vesicular rocks.

The Role for AVE0991 (MAS-Receptor Angiotensin II (1-7) Agonist) in Reducing Cisplatin-Induced Acute Kidney Injury on C57BL/6 Mice

Acute Kidney Injury (AKI) is a condition that causes nephrotoxicity in kidney tissues due to cisplatin-induced cancer treatments. Hence, it is proposed in this review that AVE0991 (a MAS-receptor Angiotensin II (1-7) agonist) may reduce cisplatin-induced acute kidney injury by promoting nitric oxide production.

A Scheme Library-Based Ant Colony Optimization with 2-Opt Local Search for Dynamic Traveling Salesman Problem

The dynamic traveling salesman problem(DTSP)is significant in logistics distribution in real-world applications in smart cities,but it is uncertain and difficult to solve.This paper proposes a scheme library-based ant colony optimization(ACO)with a two-optimization(2-opt)strategy to solve the DTSP efficiently.The work is novel and contributes to three aspects:problemmodel,optimization framework,and algorithmdesign.Firstly,in the problem model,traditional DTSP models often consider the change of travel distance between two nodes over time,while this paper focuses on a special DTSP model in that the node locations change dynamically over time.Secondly,in the optimization framework,the ACO algorithm is carried out in an offline optimization and online application framework to efficiently reuse the historical information to help fast respond to the dynamic environment.The framework of offline optimization and online application is proposed due to the fact that the environmental change inDTSPis caused by the change of node location,and therefore the newenvironment is somehowsimilar to certain previous environments.This way,in the offline optimization,the solutions for possible environmental changes are optimized in advance,and are stored in a mode scheme library.In the online application,when an environmental change is detected,the candidate solutions stored in the mode scheme library are reused via ACO to improve search efficiency and reduce computational complexity.Thirdly,in the algorithm design,the ACO cooperates with the 2-opt strategy to enhance search efficiency.To evaluate the performance of ACO with 2-opt,we design two challenging DTSP cases with up to 200 and 1379 nodes and compare them with other ACO and genetic algorithms.The experimental results show that ACO with 2-opt can solve the DTSPs effectively.

Combined Effect of Concept Drift and Class Imbalance on Model Performance During Stream Classification

Every application in a smart city environment like the smart grid,health monitoring, security, and surveillance generates non-stationary datastreams. Due to such nature, the statistical properties of data changes overtime, leading to class imbalance and concept drift issues. Both these issuescause model performance degradation. Most of the current work has beenfocused on developing an ensemble strategy by training a new classifier on thelatest data to resolve the issue. These techniques suffer while training the newclassifier if the data is imbalanced. Also, the class imbalance ratio may changegreatly from one input stream to another, making the problem more complex.The existing solutions proposed for addressing the combined issue of classimbalance and concept drift are lacking in understating of correlation of oneproblem with the other. This work studies the association between conceptdrift and class imbalance ratio and then demonstrates how changes in classimbalance ratio along with concept drift affect the classifier’s performance.We analyzed the effect of both the issues on minority and majority classesindividually. To do this, we conducted experiments on benchmark datasetsusing state-of-the-art classifiers especially designed for data stream classification.Precision, recall, F1 score, and geometric mean were used to measure theperformance. Our findings show that when both class imbalance and conceptdrift problems occur together the performance can decrease up to 15%. Ourresults also show that the increase in the imbalance ratio can cause a 10% to15% decrease in the precision scores of both minority and majority classes.The study findings may help in designing intelligent and adaptive solutionsthat can cope with the challenges of non-stationary data streams like conceptdrift and class imbalance.

Data inversion of multi-dimensional magnetic resonance in porous media

Since its inception in the 1970s,multi-dimensional magnetic resonance(MR)has emerged as a powerful tool for non-invasive investigations of structures and molecular interactions.MR spectroscopy beyond one dimension allows the study of the correlation,exchange processes,and separation of overlapping spectral information.The multi-dimensional concept has been re-implemented over the last two decades to explore molecular motion and spin dynamics in porous media.Apart from Fourier transform,methods have been developed for processing the multi-dimensional time-domain data,identifying the fluid components,and estimating pore surface permeability via joint relaxation and diffusion spectra.Through the resolution of spectroscopic signals with spatial encoding gradients,multi-dimensional MR imaging has been widely used to investigate the microscopic environment of living tissues and distinguish diseases.Signals in each voxel are usually expressed as multi-exponential decay,representing microstructures or environments along multiple pore scales.The separation of contributions from different environments is a common ill-posed problem,which can be resolved numerically.Moreover,the inversion methods and experimental parameters determine the resolution of multi-dimensional spectra.This paper reviews the algorithms that have been proposed to process multidimensional MR datasets in different scenarios.Detailed information at the microscopic level,such as tissue components,fluid types and food structures in multi-disciplinary sciences,could be revealed through multi-dimensional MR.

行为安全“2-4”模型及其在煤矿安全管理中的应用

通过观察事故统计得知,几乎100%的生产安全事故是责任事故,且是由于事故单位的"管理漏洞"所引起。理论分析得知,应用古典、近代及已有的现代事故致因链不能够精确定位"管理漏洞"的具体位置和内容,事故预防困难。根据组织行为学原理,并研究国内外已有事故致因链发现并提出了行为安全"2-4"模型这个新型现代事故致因链。在该模型中,将事故的原因首先分解为组织行为、组织成员个人行为两个层面,然后再将组织行为继续细化分解为指导行为、运行行为,将个人行为细化分解为习惯性行为、一次性行为4个行为阶段,分别对应事故的根源、根本、间接、直接原因,具体内容分别是安全文化,安全管理体系,安全知识、意识和习惯,不安全动作和不安全状态。煤矿事故案例分析证实,应用该模型,且把"安全管理"表达为"行为控制"之后,可以将导致事故发生的关键原因"管理漏洞"、"管理缺欠"理解为"行为控制缺欠",并可将其精确定位在"2"个层面、"4"个行为阶段的其中一个或几个上面,据此即可制定有效、明确的事故预防措施。

一个关于临界地震的临界区域判别的方法

由临界地震的概念和外推 Bowman等人关于孕育未来地震半径的思想 ,发展出一个临界圆重叠方法来寻找未来强震的临界区域位置。模拟实验的对比检验表明这种方法是有效的。使用主震前一定时间内地震目录 ,这个方法能找出临界区域 ,而未来震中位置将位于临界区域内或其边缘。使用新西兰和中国新疆南部的中强震目录检验 ,该方法可以在震前较准确地定位出强震的临界区域位置。使用中国 1 995年至 1 999年 8月的小震目录 ,给出 1 999年 8月以后中国未来强震临界区域的分布 ,而 1 999年 8月以后至 2 0 0 0年 6月 1 6日 (截稿日期 )在中国 (除西藏地区外 )所发生的 5.0级以上的地震几乎均位于所给出的临界区域内。

长江流域现代沉积物碎屑锆石U-Pb年龄物源探讨

长江流域上游到入海口共10个现代沉积物样品碎屑锆石U-Pb年龄分析表明,200～300、400～500、750～850和1800～2000Ma这4组年龄是长江流域沉积物U-Pb年龄的主要组成,出现在大多数样品中,其中又以200～300、750～850Ma占主体。10个样品中大多数锆石颗粒Th/U>0.3,说明这些锆石多是岩浆成因的锆石。所有样品锆石年龄的重叠度和相似度都在0.6以上,说明长江流域现代沉积物在不同河段,其锆石U-Pb年龄相近。通过与长江流域可能物源区羌塘地块、义敦岛弧、松潘甘孜复理石盆地、扬子克拉通、秦岭造山带、大别造山带几个构造单元锆石U-Pb年龄对比发现,除了羌塘地块和义顿岛弧之外,其他几个构造单元几乎都包括200～300、400～500、750～850和1800～2000Ma这4组年龄,因此,由锆石U-Pb年龄判别不出具体的物源供给。在青藏高原东部的红河和湄公河沉积物中反映出与长江流域相似的U-Pb年龄谱,从而进一步证实由于长江流域可能物源区锆石U-Pb年龄的相似性,单一碎屑锆石U-Pb年龄方法不能把各个物源区区分开来,有必要与其他物源分析方法相结合。

基于ROI的压缩域多谱段遥感图像的检索

根据JPEG2000对感兴趣区域优先编码,以及感兴趣区域的形状可随意选取的特点,提出了一种在JPEG2000压缩码流不完全解码的情况下,实现多谱段遥感图像感兴趣目标的检索方法,该方法利用了遥感图像的性质,根据例子图像的谱特征对感兴趣区域的内容进行分析,并设计了一套相似性度量的方法。实验结果表明,此方法有较理想的图像检索效果和很高的检索效率,解决了应用上对实时性的高要求与遥感图像库数据海量性之间的矛盾。

中国人头发纤维在UVA紫外光老化中的光谱学研究

生活中,日光中的紫外辐射是导致头发光老化/光损伤的重要环境因素。长时间光照可使染发和天然发出现包括颜色褪变在内的退行性变化。以中老年人的自然灰发为样本来源,通过分离和人工漂染处理,获得了包括自然发色、漂白和染黑的六种头发类型,经过UVA（320～400nm）紫外光老化,采用漫反射光谱、三维荧光光谱和衰减全反射傅里叶变换红外光谱对头发纤维的老化特征进行无损分析,结合头发中光产生过氧化氢的定量分析,探讨了不同发色和漂染处理对头发耐光性的影响。结果表明,UVA辐照可通过Ⅱ型电子转移机制诱导头发中的光敏基团产生过氧化氢,导致纤维表面蛋白和色素分子的光氧化降解。自然发色与漂染发在光老化中的颜色变化不同：灰发和白发主要发生光黄化,人工染发和漂白发分别发生光褪色和光漂白。高湿度环境能加速头发的光降解。化学漂染处理会使头发中的光致过氧化氢水平升高,使纤维处于较高的氧化压力从而影响头发的光稳定性;而头发中的黑色素分子,包括天然黑色素和染发剂的人工黑色素,可能具有自由基产生与清除双重性。研究结果为建立中国人头发光损伤的光谱学评价方法和进一步研发针对国人发质的染护发产品提供了重要的实验基准数据。