绿茶中茶多酚的分析方法研究进展

茶多酚是茶叶中一类具有强抗氧化作用的多酚类化合物的总称,具有抗氧化、抗炎、抗肿瘤、抗辐射、抗病毒等多种药理作用,其含量对茶叶的品质有非常重要的影响。但是,茶多酚结构复杂,不易准确测定,制约着对茶多酚的深入研究。综述近年来国内外对茶多酚的分析测定方法,重点阐述滴定法、红外光谱法、分光光度法、高效液相色谱法、气相色谱法等研究方法的应用和进展,为进一步研究提供参考。     

间接碘量法测定胆矾中铜含量的微型化

利用自己研制的微型滴定装置(WDCOⅡ型微型滴定装置),采用间接碘量法法测定胆矾中铜含量,操作简便快速,尤其是将测定微型化大大地降低了该实验的成本。对于"绿色化学"具有重要的实际意义。将常规滴定与微型滴定的平行结果进行了比较,得到的结果非常接近,且均具有较好的精密度。证明WDCOⅡ型微型滴定装置具有较好的操作性能,同时也证明了该实验微型化具有可行性和必要性。     

延胡索与不同药物配伍中总生物碱含量的测定

目的:探讨延胡索不同配伍中总生物碱的含量变化,为有效指导临床用药和中药新产品的研发提供依据。方法:采用水煎煮法提取总生物碱,利用生物碱盐类易溶于水的原理提取出游离的生物碱和生物碱盐类,再调节pH值,在碱性条件下用有机溶剂萃取,提取出生物碱。采用酸碱滴定法测定总生物碱,按消耗的硫酸计算出总生物碱含量,比较延胡索配伍中总生物碱含量的差别。结果:延胡索、延胡索与白芷、延胡索与当归不同配伍中,总生物碱的含量分别是1.81mg/g、2.36mg/g、1.99mg/g。延胡索与白芷配伍中总生物碱含量最高,其次是延胡索与当归配伍中总生物碱的含量,延胡索中总生物碱的含量在三者中最少。结论:延胡索与白芷、延胡索与当归配伍中总生物碱的含量比延胡索高,为延胡索与这些药物配伍的合理性研究提供了初步的依据。     

CPAP治疗OSAHS压力滴定方式选择-A、B还是C?

目的本研究评估三种不同的压力滴定方式首夜治疗的疗效及对OSAHS患者睡眠质量的影响。方法选取上海瑞金医院睡眠呼吸疾病诊疗中心就诊的中重度OSAHS患者60例,年龄24～72岁。随机采取不同的压力滴定方式,分为APAP（A组）,BiPAP（B组）和CPAP（C组）各20例。同时行PSG监测,比较各组治疗前后呼吸暂停低通气指数（AHI）,氧减指数（ODI）,微觉醒指数（mArI）以及所滴定的最适压力,以及对微觉醒,睡眠效率的影响。结果滴定前及滴定后AHI,氧减指数,微觉醒指数三组间均无明显差异。A,B,C组平均压力依次为11．05±1．23cmH2O,9．65±1．93cmH2O,9．15±1．95cmH2O（P〈0．01）。睡眠参数的改善三组间无显著性差异。C组S3＋S4＋REM时相占TST百分比较治疗前明显增加（P〈0．05）。结论三种方式均可有效滴定并改善睡眠效率。传统CPAP治疗时深睡眠改善更明显。仅一夜APAP治疗能否确定最适CPAP治疗压力仍需进一步研究。     

卵磷脂络合碘的制备及电位法测定碘的含量

目的:合成了卵磷脂络合碘,并建立一种以电位滴定法测定卵磷脂络合碘中碘含量的方法.方法:以卵磷脂和碘为原料,乙醚为反应溶剂,三者混合并充分搅拌,回收乙醚得卵磷脂络合碘.采用氢氧化钾乙醇溶液(v/v,1∶5)回流,水解卵磷脂络合碘,以 0.05 mol·L-1硝酸银为标准溶液进行滴定,用电位变化判断滴定终点,从而测定其中碘的含量.结果与结论:合成方法简单,收率高(>96%),合成工艺中使用的乙醚可回收使用,无污染.所建立的电位滴定法测定卵磷脂络合碘中碘的含量,滴定突跃明显,平均回收率为100.1%(RSD为0.21%),精密度RSD为0.34%(n＝6),结果令人满意.     

Comparison of automated solid phase versus manual saline indirect antiglobulin test methodology for non-ABO antibody titration: Implications for perinatal antibody monitoring

Background

Accurate antibody titration is crucial in prenatal evaluations to identify patients who need clinical monitoring for hemolytic disease of the fetus and newborn (HDFN) causing fetal anemia. This study compares the established gold standard method of manual tube saline indirect antiglobulin testing (SIAT) with the newer automated solid phase (ASP) method of antibody titration and aims to establish the critical titer threshold for ASP that corresponds to the previously established SIAT critical threshold of ≥16 used in our laboratory.

Study Design and Methods

One hundred fifty-seven prenatal and donor plasma samples with known antibodies were tested using both SIAT and ASP methodologies and results were compared.

Results

The study found that ASP titers were, on average, 1.33 dilutions higher than SIAT titers. The critical titer cutoff for ASP was determined to be ≥32, which is one tube higher than the SIAT cutoff of ≥16.

Discussion

The ASP method for antibody titration offers greater reproducibility and efficiency compared with manual SIAT titration. This study suggests that a titer cutoff of ≥32 is appropriate for most clinically significant antibodies using ASP. However, further research is needed to determine the comparability of ASP with SIAT in samples with multiple antibodies, anti-M antibodies, and other less common antibodies. Validation of the ASP titer cutoff against HDFN clinical outcomes is required before implementing this test for routine use in perinatal antibody titration.     

Effect of Ionic Strength and Anion Identity on Rare-Earth Element Chelation by Poly(acrylic acid)

Rare-earth elements (REEs) are critical components of many modern technologies, but their efficient separation and purification continue to pose significant challenges. Metal-binding polymers may enable the development of promising alternative approaches to conventional separation techniques (e.g., solvent extraction), and insights into the interactions between the metal ions and polymers in solution are crucial to such development. In this work,  the effect of ionic strength on the chelation of REEs by poly(acrylic acid) is investigated using isothermal titration calorimetry (ITC) to measure the metal-binding thermodynamics. ITC experiments revealed that when ionic strength increases from increasing the sodium acetate buffer strength, polymer-REE binding becomes increasingly disfavored. However, when ionic strength is increased by the addition of sodium chloride, binding again becomes increasingly disfavored, but to a lesser extent than when ionic strength increases from increasing the buffer strength. Additionally, the reduction in binding affinity is enthalpically driven when ionic strength is raised with sodium chloride, while it is entropically driven when raised with sodium acetate buffer, suggesting competive binding by the acetate ions. These results highlight the importance of ionic strength in polymer-metal binding thermodynamics and will guide the development of new processes for the purification of critical metals.     

Efficacy and safety of basal-first titration order in individuals with type 2 diabetes receiving short-term intensive insulin therapy: An exploratory analysis of BEYOND V

Aims

To present the results of an exploratory analysis of the BEYOND V study in which Chinese individuals with uncontrolled type 2 diabetes (T2D) received short-term intensive insulin therapy (SIIT) during study run-in (prior to randomization) using a basal-first insulin titration method.

Materials and methods

This was exclusively an exploratory analysis of the 7- to 10-day run-in period of BEYOND V. Participants were hospitalized and had oral therapies withdrawn (except metformin). They received SIIT with once-daily insulin glargine and three-times-daily premeal insulin glulisine, titrated daily from a total starting dose of 0.4 to 0.5 units/kg/d, first adjusting insulin glargine to achieve fasting blood glucose (FBG) of 4.4 to 6.1 mmol/L (79 to 119 mg/dL), then insulin glulisine to achieve pre-meal blood glucose of 4.4 to 6.1 mmol/L. Key outcomes were the proportions of participants achieving FBG and 2-hour postprandial blood glucose (PBG) targets.

Results

Overall, 397 entered the run-in (mean 54.2 years, 235 males [59.2%]). At the end of SIIT, 374/396 participants (94.4%) had both FBG <7.0 mmol/L (<126 mg/dL) and 2-hour PBG <10 mmol/L (<180 mg/dL) and 282/396 (71.2%) had both FBG <6.1 mmol/L (<100 mg/dL) and 2-hour PBG <10 mmol/L. The mean first time taken to achieve FBG <7 mmol/L, 2-hour PBG <10 mmol/L, and both, was 4.35, 3.88, and 5.04 days, respectively. Hypoglycaemia occurred in 99 participants (24.9%). There was no severe hypoglycaemia.

Conclusions

Titrating basal insulin first is an effective and safe method of SIIT in individuals with T2D, rapidly achieving target glucose levels with a relatively low rate of hypoglycaemia.     

氨基糖苷类及多肽类抗生素中硫酸盐的两种测定方法比较

的：比较并探讨氨基糖苷类及多肽类抗生素中硫酸盐的两种测定方法。方法：用络合滴定法和HPLC-ELSD法分别对三种抗生素中的硫酸盐进行测定；HPLC-ELSD法色谱柱为Grace Apollo C18（4.6 mm×250 mm，5 μm），流动相为0.2 mol﹒L-1三氟乙酸溶液-甲醇柱温35 ℃，进样量20 μl。结果：进行两种方法配对t检验分析，t=0.436，P＞0.05，结果无显著性差异。结论：络合滴定法为经典分析方法，成本低廉，但需要始终保持待测液pH值11，且调节pH时应注意避免反应离子及待测离子的损失，操作繁琐，耗时较长，在滴定过程中产生的白色沉淀对终点的判断有影响，主观性较强；而HPLC-ELSD法测定三种抗生素中的硫酸盐，专属性、准确度、精密度均良好 ,方法易操作，克服了滴定法判断终点的主观性，能更为准确快捷地测定氨基糖苷类及多肽类抗生素中硫酸盐的含量。