Hollow fiber-based liquid phase microextraction followed by analytical instrumental techniques for quantitative analysis of heavy metal ions and pharmaceuticals

Hollow-fiber liquid-phase microextraction(HF-LPME)and electromembrane extraction(EME)are miniaturized extraction techniques,and have been coupled with various analytical instruments for trace analysis of heavy metals,drugs and other organic compounds,in recent years.HF-LPME and EME provide high selectivity,efficient sample cleanup and enrichment,and reduce the consumption of organic sol-vents to a few micro-liters per sample.HF-LPME and EME are compatible with different analytical in-struments for chromatography,electrophoresis,atomic spectroscopy,mass spectrometry,and electrochemical detection.HF-LPME and EME have gained significant popularity during the recent years.This review focuses on hollow fiber based techniques(especially HF-LPME and EME)of heavy metals and pharmaceuticals(published 2017 to May 2019),and their combinations with atomic spectroscopy,UV-VIS spectrophotometry,high performance liquid chromatography,gas chromatography,capillary elec-trophoresis,and voltammetry.

SURFACE OIL FLOW TECHNIQUE AND LIQUID CRYSTAL THERMOGRAPHY FOR FLOW VISUALIZATION IN IMPULSE WIND TUNNELS

This paper describes flow visualization techniques employing surface oil flow and liquid crystal thermography suitable for use in impulse wind tunnels.High spatial resolution photographs of oil flow patterns and liquid crystal thermograms have been obtained within test times ranging from 7 to 500 ms and have been shown to be very useful for revealing the detailed features of 3-D separated flow.The results from oil flow patterns,liquid crystal thermograms,schlieren photographs and heat flux measurements are shown to be in good agreement.

Techniques for Treating Sulphuric Acid Pickling Waste Liquid of Steel Industry

Pickling waste liquid of the steel industry is included in National Hazardous Wastes Catalogue because of its high corrosion and large discharge. The techniques for treating pickling waste liquid （ H2SO4 ） in steel industry is summarized. The advantages, disadvantages and applied ranges of all kinds of control technologies are comparatively analysed. The research trends of techniques for treating pickling waste liquid （ H2SO4 ） are the resource reclamation technologies in future which is pointed out in the paper.

Creation of reversed phase high-performance liquid chromatographic technique to assay platelet-activating factor

Objective: To establish a new assay for platelet-activating factor (PAF), to compare it with bio-assay; and to discuss its significance in some elderly people diseases such as cerebral infarction and coronary heart disease. Methods: To measure PAF levels in 100 controls, 23 elderly patients with cerebral infarction and 65 cases with coronary heart disease by reversed phase high-performance liquid chromatographic technique (rHPLC). Results:rHPLC is more convenient, sensitive,specific, and less confusing, compared with bio-assay. The level of plasma PAF in patients with cerebral infarction was higher than that in the controls (P<0.01), and in patients with coronary heart disease. Conclusion: Detection of PAF with rHPLC is more reliable and more accurate. The new assay has important significance in PAF research.

Comparative Study of Cell Findings by Conventional Smear and Liquid-Based Cytology for Oral Exfoliative Cytology

Background: Liquid-based cytology (LBC) is a method of manufacturing cyto-diagnostic specimens. Improved accuracy is expected from standardizing specimen production and use of this method is rapidly spreading in oral cytology. On the other hand, LBC reportedly requires training to show peculiar cell findings compared to those of conventional smear cytology (CVC). Few studies have compared detailed cell findings for oral CVC and LBC. Objectives: The aim of this study was to compare cytological findings between CVC and LBC using cytomorphological image analysis. Materials and Methods: Cytological specimens were collected from 20 patients (negative for squamous neoplasia in 10, dysplasia in 5, squamous cell carcinoma in 5) and 5 controls of the tongue between January 2017 and December 2018. Two different preparation techniques were investigated cytomorphologically for CVC and LBC (BD CytorichTM). Results: LBC showed significantly higher cell numbers than CVC for all lesions. LBC-to-CVC ratio ranged from 9.52 (hyperkeratosis) to 1.87 (deep cells in oral squamous cell carcinoma (OSCC)). Nuclear area of normal, hyperkeratosis, and inflammation were significantly higher in LBC than those of CVC. Hyperchromasia was significantly more frequent with CVC than with LBC for hyperkeratosis, inflammation, dysplasia and OSCC. There was no significant difference in circularity between CVC and LBC among all lesions. Conclusion: Only one cytomorphological disadvantage was seen with LBC, in the form of decreased hyperchromasia. Further clarification of the advantages and disadvantages of LBC is needed, including management of precision and screening practices.

Promoter Methylation, BRAF Mutation Analysis and Topoisomerase IIa Expression for the Detection of Endometrial Carcinoma in Liquid Based Cytology Samples

Cancer of the corpus uteri remains the most common gynecological related cancer in developed countries. Cytology, after the induction of liquid based cytology, has reemerged as a possible first line non-interventional diagnostic procedure with promising results. Apart from slide preparation for cytology diagnosis, LBC allows the application of elaborate molecular tests on the residual material. Samples from 74 symptomatic women were collected in ThinPrep?PreservCyt medium, from witch immunocytochemical and molecular tests were performed. Final diagnosis of 39 endometrioid carcinomas, 20 non-endometrioid carcinomas and 15 non-malignant was set after hysterectomy. Topoisomerase IIa expression was common (42%) in both types of cancer. Promoter methylation analysis revealed that hMLH1 is commonly methylated in cancers (52.7%), CDKN2A and MGMT less often (27.1%) and RARB rarely methylated (8.4%). BRAF activating mutation V600E was a rare event (8.4%) only found in low grade endometrioid carcinomas. Topoisomerase IIa expression correlated with BRAF mutations, hMLH1 and to lesser extent with CDKN2A methylation. Almost none of the biomarkers were positive in cytological negative or hyperplastic without atypia samples. Detection of methylation in any gene displayed sensitivity, specificity, PPV and NPV similar to cytology of cancer. However, inclusion of cytology diagnosis of hyperlasias with atypia increased sensitivity and NPV of cytology outperforming methylation of any gene. Further evaluation of the panel of promoter methylation, especially in cytology diagnoses of hyperplasia with or without atypia should be evaluated since initial results are promising. Even though methylation of MGMT and RARB are rare events, some patients could be benefit from specific chemotherapeutics that target either of them or the more frequently expressed topoisomerase IIa.

Liquid Based Cytology of Cell Remnants in Needles Used for Breast Fine Needle Aspiration

This study examined cells contained in needles used for the collection of breast fine needle aspirates for the detection of malignant cells trapped in the needles. Remnants of cells contained in 50 needles used for the collection of scanty breast fine needle aspirates were examined by the liquid based cytology technique and compared with the conventional cytological technique of specimens in the corresponding syringes. The breast specimens were collected with clean sterile needles attached to the syringes. Smears were made and stained by the conventional method. The needles were removed from the syringes and a fixative was withdrawn into the syringes and the syringes were recapped with the needles. The fixative containing the specimen was then completely discharged into a centrifuge tube through the needles and treated by the liquid based cytology technique. The study revealed that cells were found trapped in all the needles used for the collection of breast FNA. 6% of them were positive for malignancy, similar to results obtained in the conventional method. Needles used for the collection of breast FNA should be examined before malignancy is completely ruled out particularly in extremely scanty specimens with a clinical suspicion of malignancy.

Ultrasonic Resonator Techniques for Broad-band Spectroscopy and for High-resolution Sound Velocity Measurement of Liquids

This review gives a short introduction into the principles of ultrasonic measurement techniques for liquids, using cavity resonators. Guidelines for the resonator design in broad-band ultrasonic stxctroscopy as well as in high-resolution single-frequncy or narrowband applications are presented. Deviations of the field configuration in real cells frtxn that in an ideal resonator are discussed and relations for the mode spectrum of cavity fields are given. Recent resonator measurement procedures and methods of data evaluation are mentioned briefly. Some examples of measurements show the extended usability of ultrasonic resonator techniques in basic science and in a wide range of applications for rrkaterials characterization, in manufacturing processes, as well as in control routines.

Vaginal Intraepithelial Neoplasia Detected with Cervical Liquid-Based Cytology: Old Concerns or New Facilities?

Background: The detection of vaginal intraepithelial neoplasia (VAIN) in cervical samples is not a common finding. Therefore, we aimed to report VAINs detected in liquid-based cytology (LBC) from women examined at Hospital das Clínicas of Faculty of Medicine, Sao Paulo State University. Materials and Methods: We evaluated LBC samples from women referred to gynecology examination for different reasons (previous abnormal PapTest, follow up of treated cervical lesion, ecc) and women examined for regular screening proposals, and compared with biopsy diagnoses, including the controversial diagnoses of vaginal intraepithelial neoplasia (VAIN). Results: From 1866 patients, 1423 (76.3%) cases were negative and 443 (23.7%) were positive for any cellular alteration. Age of patients ranged from 12 to 86 years. We detected 25 histologically confirmed VAIN (1.3% p = 0.0002 by Fisher’s exact test IC 95% 0.0090 - 0.0198) and 1.1% VAIN (p = 0.0031 by Fisher’s exact test IC 95% 0.0077 - 0.0179). Conclusion: The identification of VAIN in routine is feasible;the professionals involved with cytological examination should be aware of these lesions in Pap test samples.

Liquid phase separating mechanism and preparation techniques of immiscible alloys

Immiscible alloys have attracted growing interest for their valuable physical and mechanical properties. However, their production is difficult because of metallurgical problems in which there is a serious tendency for gravity separation in the region of the miscibility gap. So far the study on the liquid separation mechanism is still one of the important projects in the spatial materials science and the spatial fluid science. The studied results about the liquid phase separating mechanism of immiscible alloys are presented, at the same time the preparation techniques of homogeneous immiscible alloys are summarized, and the existing problems and the related researching areas in the future are also pointed out.

Immediate-release Mechanism of Dehydrotrametenolic Acid and Dehydroeburicoic Acid in Poriae Cutis Total Triterpenoids Tablets Based on Liquid-solid Compact Technique

[Objectives]To study the immediate-release mechanism of dehydrotrametenolic acid and dehydroeburicoic acid in Poriae Cutis total triterpenoids tablets by liquid-solid compacts technique.[Methods] Taking dehydrotrametenolic acid and dehydroeburicoic acid as indicators,differences in dissolution were compared between liquid-solid compressed tablets and crude drug of total triterpenoids in Poriae Cutis;crude drug,powder of liquid-solid compressed tablets and excipients of liquid-solid compressed tablets were characterized by differential scanning calorimetry( DSC).[Results]Liquid-solid compact technique could significantly improve dissolution rate of dehydrotrametenolic acid and dehydroeburicoic acid. The total dissolution rate of dehydrotrametenolic acid and dehydroeburicoic acid in Poriae Cutis total triterpenoids tablets was 92%,t50( time for 50% total dissolution rate) and t_D( time for 63. 2% total dissolution rate) were 11. 18 min and 22. 71 min; the total dissolution rate of dehydrotrametenolic acid and dehydroeburicoic acid in crude drug of total triterpenoids was 29%,and t50 and t_D were231. 06 min and 359. 23 min. DSC showed that there was no mutual interaction between excipients and total triterpenoids in Poriae Cutis; on the DSC curve for powder of liquid-solid compressed tablets,the absorption peak vanished completely,indicating that the drug exists in the amorphous form in the liquid-solid powder.[Conclusions] Liquid-solid compact technique can increase the dissolution rate of total triterpenoids in Poriae Cutis and allow rapid release of poorly water soluble drugs.

Slow-pull and different conventional suction techniques in endoscopic ultrasound-guided fine-needle aspiration of pancreatic solid lesions using 22-gauge needles

AIM To evaluate the cytological diagnostic capacity and sample quality of the slow-pull technique and compare them with different suction techniques.METHODS From July 2010 to December 2015, 102 patients with pancreatic solid lesions who underwent endoscopic ultrasound-guided fine-needle aspiration(EUS-FNA) with 22-gauge needles were retrospectively evaluated. EUS-FNA diagnosis was based on a cytological examination, and final diagnosis was based on a comprehensive standard of cytological diagnosis, surgical pathology and clinical or imaging follow-up. Cytological specimens were characterized for cellularity and blood contamination. The cytological diagnostic capacity and sample quality of the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were analyzed.RESULTS Of all of the EUS-FNA procedures, the slow-pull technique and suction techniques with 5-m L/10-m L/20-m L syringes were used in 31, 19, 34 and 18 procedures, respectively. There were significant differences between these four suction techniques in terms of cytological diagnostic accuracy(90.3% vs 63.2% vs 58.8% vs 55.6%, P = 0.019), sensitivity(88.2% vs 41.7% vs 40.0% vs 36.4%, P = 0.009) and blood contamination(score ≥ 2 for 29.0% vs 52.6% vs 70.6% vs 72.2%, P = 0.003). The accuracy and sensitivity of the slow-pull technique were significantly higher than those of the suction techniques using 5-m L(P = 0.03, P = 0.014), 10-m L(P = 0.005; P = 0.006) and 20-mL syringes(P = 0.01, P = 0.01). Blood contamination was significantly lower in the slow-pull technique than in the suction techniques with 10-m L(P = 0.001) and 20-mL syringes(P = 0.007).CONCLUSION The slow-pull technique may increase the cytological diagnostic accuracy and sensitivity with slight blood contamination during EUS-FNA when using 22-gauge needles for solid pancreatic masses.

BREAK-UP MECHANISM OF METAL DROPLETS GENERATED BY AN ELECTROHYDRODYNAMIC TECHNIQUE

Nanometer powders can be produced by an electrohydrodynamic technique. The breakup mechanism of the metal droplets generated by the electrohydrodynamic technique was analysed. It showed that the applied voltage, the electric field Btrength, the properties of the molten metal and the volumetric flow rate of the molten metal directly effect the breat-up extent of the metal droplets.

高效液相色谱及其串联质谱技术在牙膏风险物质分析中的应用

牙膏是日常生活中必不可少的口腔清洁护理用品,牙膏的基料较为复杂,牙膏中潜在的风险物质对人体存在一定危害,因此牙膏产品的安全性已成为当今社会关注的焦点之一。利用现代先进的检验检测技术对牙膏中潜在的风险物质进行分析、研究,将有利于实现对牙膏产品的安全监管,本文综述了近几年来高效液相色谱及其串联质谱技术在牙膏产品检验标准和检验方法开发等方面的研究以及应用进展,一定程度上能为牙膏产品的质量控制和科学监管提供参考。

液基细胞学制片巴氏染色临床诊断真菌性阴道炎的价值

目的探讨液基细胞学制片巴氏染色诊断真菌性阴道炎的临床价值。方法选取2020年4月至2021年6月期间在河南中医药大学第三附属医院门诊或住院的具有典型临床症状、初步诊断为真菌性阴道炎的251例患者进行研究。共采集到有效标本230例,阴道微生态方法检测128例(有效标本122例),白带常规检测123例(有效标本108例),所有标本均接受液基细胞学制片巴氏染色方法检测,以真菌培养结果作为诊断金标准,绘制2×2配对四格表计算相关诊断学指标,绘制受试者工作特征(ROC)曲线计算曲线下面积(AUC)分析液基细胞学制片巴氏染色用于诊断真菌性阴道炎的价值。结果采用阴道微生态、液基细胞学两种方法检查的122例患者,经真菌培养共计检测出真菌感染患者52例,其中最主要的真菌类型为白色念珠球菌25例(48.08%),其次为光滑念珠球菌18例(34.62%);阴道微生态诊断阴道真菌感染的灵敏度为75.00%、特异度为91.43%、阳性预测值为86.67%、阴性预测值为83.12%、ROC曲线下面积AUC值为0.784;液基细胞学诊断阴道真菌感染的灵敏度为95.74%、特异度为90.67%、阳性预测值为86.53%、阴性预测值为97.14%、ROC曲线下面积AUC值为0.918;接受白带常规、液基细胞学两种方法检查的108例患者,经真菌培养共计检测出真菌感染患者51例,其中最主要的真菌类型为白色念珠球菌27例(51.92%),其次为光滑念珠球菌15例(28.85%);白带常规诊断阴道真菌感染的灵敏度为96.08%、特异度为75.44%、阳性预测值为77.78%、阴性预测值为95.56%、ROC曲线下面积AUC值为0.824;液基细胞学诊断阴道真菌感染的灵敏度为96.97%、特异度为88.71%、阳性预测值为86.27%、阴性预测值为96.49%、ROC曲线下面积AUC值为0.914。结论液基细胞学制片巴氏染色作为一种新的真菌定性检测方法,应用于临床诊断真菌性阴道炎较阴道微生态方法具有更高的灵敏度,较白带常规具有更高的特异性,同时保证诊断的准确性,具有一定的临床应用价值。

纤支镜下刷检薄层液基细胞学检查在肺癌诊断价值的研究

目的:研究纤支镜下刷检薄层液基细胞学检查(LCT)在肺癌诊断价值。方法:选取2023年4月到2024年3月间江门市新会区人民医院呼吸与危重症医学科首诊患者80名,所有患者均采用传统支气管镜活检、刷检涂片细胞学检查和刷检LCT检查的方法。传统刷检涂片细胞学检查(CS)为对照组,支气管镜刷检LCT检查为液基组,支气管镜活检为钳检组。对比各组对肺癌诊断阳性率,分析液基组及对照组对肺癌组织类型的检查情况,对比两组对肺癌组织类型的检查结果。结果:液基组对肺癌诊断的阳性率为40.00%(32/80),较对照组的25.00%(20/80)明显更高(P<0.05)。但液基组与钳检组比较,差异不显著(P>0.05)。LCT对肺癌鳞癌诊断的符合率为83.33%(10/12),对腺癌的诊断符合率为42.86%(6/14),对小细胞癌的诊断符合率为75.00%(9/12)。CS对肺癌鳞癌诊断的符合率为41.67%(5/12),对腺癌的诊断符合率为66.67%(8/12),对小细胞癌的诊断符合率为35.71%(5/14)。液基组对于肺癌组织类型为鳞癌以及小细胞癌的符合率较对照组更高(P<0.05),但两组对腺癌的符合率比较,差异不显著(P>0.05)。结论:应用纤支镜下刷检LCT检查在肺癌的诊断价值较高,且值得在临床诊断过程中给予推广。

基于高速摄像法的气液段塞流特性参数测量

在气-液两相段塞流中,液膜段的湿壁分数和弹头倾角是研究气弹段持液率和气弹特性的关键.文章基于光学成像技术设计了高速摄像法的视觉传感器测试系统,实现了气液两相段塞流气弹特性参数测量.基于图像分析技术,优化边缘检测算子,精确定位边缘位置,高质量提取了轮廓分布,将机器学习模型作为预测多相流特征参数的一种新方法,对气弹弹头倾角进行数据建模研究,分析了适用于分层平滑流、波浪和环状流的表观粗糙表面(modified apparent rough surface,MARS)模型以及段塞流气弹区和液膜区流动状态机理,在MARS模型基础上进行了参数优化,使其适用于段塞流液膜处的湿壁分数和持液率求解.结果表明:通过数据拟合的多项式模型弹头倾角α的模型预测结果的平均绝对百分比误差(MAPE)为8.87%,94.6%预测结果处于相对误差±20%的范围内.通过修正MARS模型提出的水平管段塞流液膜处湿壁分数预测结果的MAPE为9.42%,96.1%预测结果处于相对误差±20%的范围内.液膜持液率预测模型结果的MAPE约为8.04%,93.4%预测结果处于相对误差±20%的范围内.

华为云ModelArts平台驱动的AI辅助诊断系统在宫颈液基细胞学非典型病变检出中的应用研究

目的探索并验证基于华为云ModelArts平台构建的深度学习模型在宫颈液基细胞学(liquid-based cytology,LBC)非典型细胞诊断中的应用价值,并评估其对不同诊断经验医师的辅助效果。方法回顾性分析2020年东莞市人民医院1044例宫颈脱落细胞学标本,采用华为云ModelArts平台开发的人工智能(artifical intelligence,AI)辅助诊断系统与初级、中级、高级医师进行诊断比对,计算灵敏度、特异度、精确率、符合率、曲线下面积(area under the curve,AUC)等指标,评估AI系统的诊断效能及其对不同年资医师的辅助诊断效果。采用McNemar检验比较AI系统与人工诊断的差异。结果在1044例宫颈脱落细胞学标本中,AI系统在非典型细胞检出的灵敏度和特异度分别为98.96%和89.15%,均高于初级医师(81.95%和91.81%)。AI系统的总体诊断精确率为93.68%,显著高于初级医师(87.26%,P<0.001)。AI辅助可显著提高初级医师的诊断性能,灵敏度从80.1%提升至96.5%,特异度从85.6%提升至92.3%。结论本研究构建的AI辅助宫颈细胞学诊断系统性能优越,尤其能显著提高初级医师的诊断水平,具有良好的临床应用前景。

基于代谢组学的‘铁观音’和‘水仙’品种茶叶化学成分解析

为探究茶树品种及加工工艺对茶叶化学成分的影响,本实验采用基于超高效液相色谱-飞行时间质谱的非靶向代谢组学方法对同一产地的‘铁观音’和‘水仙’茶树品种鲜叶制成的绿茶、清香乌龙茶、浓香乌龙茶和红茶展开化学成分解析。结果表明,不同品种茶树制成的茶叶化学成分具有较大差异。其中,‘铁观音’品种制成的4类茶叶中大部分脂类、生物碱类及甲基化儿茶素类化合物含量较高,‘水仙’品种制成的4类茶叶中茶氨酸、大部分儿茶素类、黄酮(醇)糖苷类、酚酸类、N-乙基-2-吡咯烷酮取代的儿茶素类化合物含量较高。加工工艺对茶叶化学成分也具有显著影响,共筛选了127种差异化合物,其中大部分儿茶素类、原花青素类、生物碱类及部分氨基酸类化合物在绿茶中的含量显著高于其他茶类;部分氨基酸类与部分黄酮(醇)糖苷类(如槲皮素-3-半乳糖苷、山柰酚-3-葡萄糖酰芸香糖苷等)化合物在清香乌龙茶中含量相对较高;浓香乌龙茶中N-乙基-2-吡咯烷酮取代的儿茶素类、部分黄酮(醇)糖苷(如槲皮素-3-葡萄糖苷、山柰酚-3-(6”-乙酰基半乳糖苷)等)及脂类化合物含量较高;而红茶中则含有更丰富的茶黄素类化合物及少部分的黄酮(醇)糖苷类化合物。本研究较为系统地阐明了‘铁观音’和‘水仙’品种茶叶的化学成分差异及不同加工工艺对茶叶化学成分的影响。

乳及乳制品中抗寄生虫药检测方法研究进展

抗寄生虫药是牛羊等产奶动物养殖过程中必不可少的投入品。这些药物经牛羊吸收代谢后,容易残留在牛羊奶及其他动物组织中,给消费者造成安全隐患。我国食品安全国家标准规定了牛羊奶中21种抗寄生虫药的最大残留限量值,科研工作者们也建立了多种检测方法。本文对2018—2023年牛羊奶中抗寄生虫药的检测方法进行综述,简要对比电化学传感器法、表面增强拉曼光谱法、胶体金免疫试纸条法、液相色谱-质谱法、液相色谱-高分辨质谱法的优缺点,并对抗寄生虫药检测方法的发展方向进行了讨论和展望,为乳及乳制品中抗寄生虫药的定性筛查和定量检测提供技术参考。