点石成色:敦煌壁画的彩色世界

敦煌壁画,作为中国古代艺术的瑰宝,是一个丰富的历史、文化、艺术和宗教文化遗产宝库,其价值不可估量。这些壁画所用的颜料,皆为天然矿物精心挑选而成,它们为敦煌壁画带来了独一无二的色彩与质感。深入理解这些颜料的特性,有助于我们更好地欣赏艺术、文化和历史的深厚底蕴,也是壁画保护与修复的基础。本文采用生动拟人化的叙述方式,通俗易懂地描绘了莫高窟壁画的色彩来源,重点阐述了常用典型的矿物颜料及其来源,旨在促进壁画的保护工作,以及文化遗产的普及、宣传和传承。

激光诱导击穿光谱(LIBS)分析虚拟仿真实验

虚拟仿真实验作为大型仪器分析实验教学模式的新兴趋势,有效地将虚拟仿真技术与实物仪器教学相结合,最大限度地提升了学生对于大型仪器分析的综合应用能力。本文以激光诱导击穿光谱(LIBS)虚拟仿真实验系统为例,完整地模拟了LIBS系统的样品处理、光谱采集、定性分析和定量分析等实际实验场景,通过虚实结合实验教学模式对实验过程进行实时跟踪与综合考评。该实验有助于提高学生自主探究能力和创新意识,培养具有独立思考与实践能力的拔尖人才。

基于Raman光谱的3,5-二氨基-1,2,4-三唑(DAT)合成反应在线监测与反应机理探究——推荐一个仪器分析综合实验

本实验介绍了一个仪器分析综合性实验——基于Raman光谱的3,5-二氨基-1,2,4-三唑(DAT)合成的在线监测与反应机理探究。该实验是一个科研转化的仪器分析综合实验,内容包括DAT的合成、基于Raman光谱的合成反应过程在线监测以及合成反应机理解析。在实验中,采用化学计量学方法对Raman光谱数据进行处理和分析,以更深入地理解合成反应的机理。通过本实验,可以巩固学生的化学专业知识,提高学生的综合实验操作技能,激发学生对科学研究的兴趣,培养学生的科研探究能力。

基于STEM教学理念的分析化学实验教学新模式探索--以“自来水硬度测定”为例

STEM是一种集科学、技术、工程、数学多学科融合的项目式教育理念,旨在通过融合多学科知识完成项目目标,从而培养学生提出问题、分析问题以及解决问题的能力,进而激发学生的科学探索精神和创新思维能力,已经成为当前国际教育研究和改革的热点。本文将STEM教育理念引入分析化学实验教学过程中,探索发展分析化学实验课程教学新模式。倡导以学生为中心、以真实问题为牵引,学生以相关课程理论为线索,自主完成实验方案设计、实验过程、实验结果分析等一系列分析化学实验过程,从而培养学生的科学探索与实践能力。主要从课程内容、教学方法以及考核方式等三个方面来探索分析化学实验教学新模式,进而提高分析化学实验的教学质量和学生的学习兴趣和科学素养。

线上线下深度融合的分析化学实验教学新模式探索--以“维生素C饮料中抗坏血酸含量的测定”为例

为了提高实验课程教学效果,提升学生的学习兴趣,培养学生的科学探索精神,充分利用线上教学平台辅助分析化学实验教学。以“维生素C饮料中抗坏血酸含量的测定”实验为例,建立线上线下深度融合的实验课教学模式,优化整个实验教学过程,记录学生的学习过程,改进实验成绩评价方式。该模式可以激发学生的实验热情,使学生的学习由被动变主动,满足学生个性化的学习需求,还有助于培养学生的严谨的科学态度、安全环保意识和实践创新能力,从而实现创新型人才培养。

Hyperthermic intraperitoneal chemotherapy for gastric cancer with peritoneal metastasis:A multicenter propensity scorematched cohort study

Objective:Systemic chemotherapy has limited efficacy in the treatment of peritoneal metastasis(PM)in gastric cancer(GC).Hyperthermic intraperitoneal chemotherapy(HIPEC)combined with complete cytoreductive surgery(CRS)has shown promising outcomes but remains controversial.The present study aimed to evaluate the safety and efficacy of HIPEC without CRS in GC patients with PM.Methods:This retrospective propensity score-matched multicenter cohort study included GC patients with PM treated with either chemotherapy alone(Cx group)or with HIPEC combined with chemotherapy(HIPEC-Cx group)in four Chinese high-volume gastric medical centers between 2010 and 2017.The primary outcomes were median survival time(MST)and 3-year overall survival(OS).Propensity score matching was performed to compensate for controlling potential confounding effects and selection bias.Results:Of 663 eligible patients,498 were matched.The MST in the Cx and HIPEC-Cx groups was 10.8 and 15.9 months,respectively[hazard ratio(HR)=0.71,95%confidence interval(95%CI),0.58-0.88;P=0.002].The 3-year OS rate was 10.1%(95%CI,5.4%-14.8%)and 18.4%(95%CI,12.3%-24.5%)in the Cx and HIPEC-Cx groups,respectively(P=0.017).The complication rates were comparable.The time to first flatus and length of hospital stay for patients undergoing HIPEC combined with chemotherapy was longer than that of chemotherapy alone(4.6±2.4 d vs.2.7±1.8 d,P<0.001;14.2±5.8 d vs.11.4±7.7 d,P<0.001),respectively.The median follow-up period was 33.2 months.Conclusions:Compared with standard systemic chemotherapy,HIPEC combined with chemotherapy revealed a statistically significant survival benefit for GC patients with PM,without compromising patient safety.

A multi-institutional retrospective study of hyperthermic plus intravesical chemotherapy versus intravesical chemotherapy treatment alone in intermediate and high risk nonmuscle-invasive bladder cancer

Objective:To compare the efficacy and safety of hyperthermic intravesical chemotherapy(HIVEC)and intravesical chemotherapy(IVEC)in patients with intermediate and high risk nonmuscle-invasive bladder cancer(NMIBC)after transurethral resection.Methods:We included 560 patients diagnosed with primary or recurrent NMIBC between April 2009 and December 2015 at 1 of 6 tertiary centers.We matched 364 intermediate or high risk cases and divided them into 2 groups:the HIVEC+IVEC group[chemohyperthermia(CHT)composed of 3 consecutive sessions followed by intravesical instillation without hyperthermia]and the IVEC group(intravesical instillation without hyperthermia).The data were recorded in the database.The primary endpoint was 2-year recurrence-free survival(RFS)in all NMIBC patients(n=364),whereas the secondary endpoints were the assessment of radical cystectomy(RC)and 5-year overall survival(OS).Results:There was a significant difference in the 2-year RFS between the two groups in all patients(n=364;HIVEC+IVEC:82.42%vs.IVEC:74.18%,P=0.038).Compared with the IVEC group,the HIVEC+IVEC group had a lower incidence of RC(P=0.0274).However,the 5-year OS was the same between the 2 groups(P=0.1434).Adverse events(AEs)occurred in 32.7%of all patients,but none of the events was serious(grades 3–4).No difference in the incidence or severity of AEs between each treatment modality was observed.Conclusions:This retrospective study showed that HIVEC+IVEC had a higher 2-year RFS and a lower incidence of RC than IVEC therapy in intermediate and high risk NMIBC patients.Both treatments were well-tolerated in a similar manner.

Raltitrexed as a synergistic hyperthermia chemotherapy drug screened in patient-derived colorectal cancer organoids

Objective:Organoids have recently been used as in vitro models to screen chemotherapy drugs in combination with hyperthermia treatment in colorectal cancer.Our research aimed to establish a library of patient-derived colorectal cancer organoids to evaluate synergism between chemotherapy drugs and hyperthermia;validate an index of the hyperthermia chemotherapy sensitization enhancement ratio(HCSER)to identify the chemotherapeutics most enhanced by hyperthermia;and recommend chemotherapy drugs for hyperthermic intraperitoneal treatment.Methods:Organoids were grown from cells extracted from colorectal cancer patient samples or colorectal cancer cell lines.Cells from both sources were encapsulated in 3 D Matrigel droplets,which were formulated in microfluidics and phase-transferred into identical cell-laden Matrigel microspheres.The microspheres were seeded in 96-well plates,with each well containing a single microsphere that developed into an organoid after 7 days.The organoids were used to evaluate the efficacy of chemotherapy drugs at both 37℃ as a control and 43℃ for 90 min to examine hyperthermia synergism.Cell viability was counted with 10%CCK8.Results:We successfully established a library of colorectal cancer organoids from 22 patient parental tumors.We examined the hyperthermia synergism of 7 commonly used hyperthermic intraperitoneal chemotherapy drugs.In 11 of the 22 patient organoids,raltitrexed had significant hyperthermia synergism,which was indexed as the highest HCSER score within each patient group.Conclusions:Our results primarily demonstrated the use of patient-derived colorectal cancer organoids as in vitro models to evaluate hyperthermia synergistic chemotherapeutics.We found that hyperthermia enhanced the effect of raltitrexed the most among the common anti-colorectal cancer drugs.

A novel strategy for quantitative analysis of soil pH via laser-induced breakdown spectroscopy coupled with random forest

pH is one of the significant properties of soil,and is closely related to the decomposition of soil organic matter,anion-cation balance,growth of plants and many other soil processes.In the present work,laser-induced breakdown spectroscopy(LIBS) technique coupled with random forest(RF) was proposed to quantify the pH of soil.First,LIBS spectra of soil was collected,and some common elements in soil were identified based on the National Institute of Science and Technology database.Then,in order to obtain a better predictive result,the influence of different input variables(full spectrum,different spectral ranges,the intensity of characteristic bands and characteristic lines) on the predictive performance of RF calibration model was explored with the evaluation indicators of root mean square error(RMSE) and coefficient of determination(R2),the characteristic bands of four elements(AI,Ca,Mg and Si) were determined as the optimal input variables.Finally,the predictive performance of RF calibration model was compared with partial least squares calibration model with the optimal input variables and model parameters,and RF calibration model showed a better predictive performance,and the four evaluation indicators of R_p^2,RMSEP,mean absolute error and mean relative error were 0.9687,0.1285,0.1114 and 0.0136,respectively.It indicates that LIBS technique coupled with RF algorithm is an effective method for pH determination of soil.

Added Value of Quantitative Apparent Diffusion Coefficients for Identifying Small Hepatocellular Carcinoma from Benign Nodule Categorized as LI-RADS 3 and 4 in Cirrhosis

Background and Aims:Correct identification of small hepa-tocellular carcinomas(HCCs)and benign nodules in cirrhosis remains challenging,quantitative apparent diffusion coeffi-cients(ADCs)have shown potential value in characterization of benign and malignant liver lesions.We aimed to explore the added value of ADCs in the identification of small(≤3 cm)HCCs and benign nodules categorized as Liver Imag-ing Reporting and Data System(LI-RADS)3(LR-3)and 4(LR-4)in cirrhosis.Methods:Ninety-seven cirrhosis patients with 109 small nodules(70 HCCs,39 benign nodules)of LR-3 and 4 LR-4 based on major and ancillary magnetic resonance imaging features were included.Multiparametric quantitative ADCs of the lesions,including the mean ADC(ADCmean),min-imum ADC(ADCmin),maximal ADC(ADCmax),ADC standard deviation(ADCstd),and mean ADC value ratio of lesion-to-liv-er parenchyma(ADCratio)were calculated.Regarding the joint diagnosis,a nomogram model was plotted using multivariate logistic regression analysis.The performance was assessed using the area under the receiver operating characteristic curve(AUC).Results:The ADCmean,ADCmin,ADCratio,and ADCstd were significantly associated with the identification of small HCC and benign nodules(p<0.001).For the joint diagnosis,the LI-RADS category(odds ratio[OR]=12.50),ADCmin(OR=0.14),and ADCratio(OR=0.12)were identified as independent factors for distinguishing HCCs from benign nodules.The joint nomogram model showed good calibration and discrimination,with a C-index of 0.947.Compared with the LI-RADS category alone,this nomogram model demon-strated a significant improvement in diagnostic performance,with AUC increasing from 0.820 to 0.967(p=0.001).Con-clusions:The addition of quantitative ADCs could improve the identification of small HCC and benign nodules catego-rized as LR-3 and 4 LR-4 in patients with cirrhosis.