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乳清酸的单扫示波极谱研究 总被引：1，自引：0，他引：1
乳清酸在０．１ｍｏｌ／ＬＨＣｌＯ４＋０．０２ｍｏｌ／ＬＮａＣｌＯ４底液中，于ＪＰ－２型示波极谱仪上，有一良好的二阶导数峰Ｅｐ＝－０．８６０±０．０１Ｖ（ＳＣＥ），浓度在１×１０－７～６×１０－５ｍｏｌ／Ｌ范围内，与峰高成线性关系，检测限为７．５×１０－８ｍｏｌ／Ｌ．实验证明，电极过程为具有催化性质的双电子可逆过程． 相似文献
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本文系统地研究了甲硝唑在汞电极上的电极过程，证明了该电极过程为一含有吸附作用的不可逆的扩散控制过程，电子转移数为４，不可逆系数ａ＝０．７１４．建立了甲硝唑的单扫示波极谱测定法，在０．２０ｍｏｌ／Ｌ的ＮａＣｌ溶液中，于－０．７１Ｖ（ｖｓＳＣＥ）处的峰高与浓度［（０．０２─８０）ｍｇ／Ｌ］间存在良好的线性关系，检测限为２．４μｇ／Ｌ，ＲＳＤ＝２．０％（ｎ＝８），并考察了人体内常见微量物质对的影响。 相似文献
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采用浸渍法制备了一系列γ－Ａｌ２Ｏ３负载的Ｃｒ－Ａｇ双金属氧化物催化剂，并考察了对ＣＯ的氧化活性．结果表明，由Ｃｒ（ＮＯ３）３、ＣｒＯ３、Ｃｒ２（Ｃ２Ｏ４）３作为Ｃｒ源制备的单组分Ｃｒ－／γ－Ａｌ２Ｏ３催化剂对ＣＯ的氧化活性基本相同，且均较差；但添加少量Ａｇ（＜２ｗｔ％）却能明显提高Ｃｒ／γ－Ａｌ２Ｏ３催化剂对ＣＯ的氧化活性，且分步浸渍法制备的Ｃｒ－Ａｇ／γ－Ａｌ２Ｏ３双组分催化剂的活性明显优于用其浸渍法制备的催化剂 相似文献
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依据酸性条件下Ａｇ（Ｉ）和Ｈｇ（Ⅱ）在ＫＳＣＮ－罗丹明Ｂ－阿拉伯树胶体系中形成多元缔合物的速度差异。用停流法研究了各种因素分别对Ａｇ（Ｉ），Ｈｇ（Ⅱ）多元缔合物体系反应速度的影响。提出了同时测定环境样品中痕量银和汞的流动注射－速差动力学光度法。本法测定Ｈｇ（Ｉ）和Ａｇ（Ⅱ）的线性范围分别为０．２－３．５μｇ／ｍｌ和０．１５－２．６０μｇ／ｍｌ。检测限为０．０１μｇ／ｍｌＡｇ（Ｉ）和０．００８μｇ／ 相似文献
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采用甲基磺酸乙酯（ＥＭＳ）诱变草鱼吻端组织细胞（ＺＣ－７９０１）．用乌苯苷（Ｏｕａｂａｉｎ）筛选抗药性突变体．结果表明，ＥＭＳ对草鱼细胞的诱变效果与该药物对哺乳类细胞的诱变效果有明显差异．草鱼细胞对乌苯苷的敏感性也大大低于哺乳类细胞．ＺＣ－７９０１细胞在传代后２４ｈ，用浓度为２．８ｍｇ／ｍｌ的ＥＭＳ处理２４ｈ，诱变效果较理想，细胞杀伤率约３０％，这比通常用ＥＭＳ诱变哺乳类细胞所使用的浓度（０．４ｍｇ／ｍｌ）增大了７倍，存留下来的细胞用浓度为２５ｍｍｏｌ／Ｌ乌苯苷筛选抗性突变体，有少数细胞存活，并具有分裂增殖能力．但在细胞瓶内不易形成单层 相似文献
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EGTA—EDTA直接滴定法测定水泥中的氧化镁 总被引：1，自引：0，他引：1
根据水泥的化学组成,利用ＥＧＴＡ与Ｃａ＾２＋、Ｍｇ＾２＋配位能力相差较大的特性提出了ＥＧＴＡ作为Ｃａ＾２＋的掩蔽剂,ＥＤＴＡ直接滴定镁的方法并讨论了Ｆｅ＾３＋、Ａｌ＾３＋、Ｔｉ＾４＋、Ｍｕ＾２＋等离子的干扰及消除。 相似文献
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报告１０８例病毒性肝炎患者血清总补体（ＣＨ＿（５０））和Ｃ＿３值的检测结果：急性肝炎的ＣＨ＿（５０）为６８．４±６．１３单位／ｍｌ，Ｃ＿３为１３０．２±６．６７ｍｇ％，均高于正常组（ＣＨ＿（５０）为４８．５±５．７５单位／ｍｌ，Ｃ＿３为１０２±５ｍｇ％），Ｐ＜０．０１；其他类型的肝炎患者组的补体均低于正常组，Ｐ＜０．０１．补体的含量与Ｔ细胞花环（Ｅｔ花环）呈中度相关，与ＧＰＴ呈高度相关，因此测定ＣＨ＿（５０）和Ｃ＿３可作为衡量患者机体免疫功能和判断病毒性肝炎预后的指标之一。 相似文献
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废水中痕量银和汞同时测定的停流式FIA－速差动力学法 总被引：2，自引：0，他引：2
依据微酸性条件下Ａｇ（Ⅰ）和Ｈｇ（Ⅱ）在ＫＳＣＮ－罗丹明Ｂ－阿拉伯树胶体系中形成多元缔合物的速度差异，用停流法研究了各种因素分别对Ａｇ（Ⅰ）、Ｈｇ（Ⅱ）多元缔合物体系反应速度的影响。提出了同时测定环境样品中痕量银和汞的流动注射－速差动力学光度法。本法测定Ｈｇ（Ⅰ）和Ａｇ（Ⅱ）的线性范围分别为０．２～３．５μｇ／ｍｌ和０．１５～２．６０μｇ／ｍｌ。检测限为０．０１μｇ／ｍｌＡｇ（Ⅰ）和０．００８μｇ／ｍｌＨｇ（Ⅱ）．常见共存离子基本不干扰测定。用本法测定了废水及混合标准溶液中银和汞含量，结果满意。 相似文献
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印度芥菜BjPCS1基因的表达提高烟草对重金属的抗性 总被引：4，自引：0，他引：4
在植物体内植物络合素(PC)可与重金属螯合,并进一步转运至液泡贮存,使细胞质的重金属浓度降低,从而达到解毒效果。PC不是基因的直接翻译产物,而是以谷胱甘肽(GSH) 为底物由植物络合素合酶催化而成。将来源于重金属超富集植物印度芥菜(Brassica juncea)的植物络合素合酶基因BjPCS1转入烟草,PCR和Northern结果表明,该基因已经整合到烟草基因组中,并在转录水平上表达。在3种重金属(200mmol/L CdCl2、400mmol/L ZnCl2、200mmo/L NiCl2)胁迫条件下,转基因烟草植株的脯氨酸含量、可溶性糖含量、丙二醛含量、相对电导率和叶绿素含量等指标均优于未转化的对照植株,表明转化BjPCS1基因提高了烟草对3种重金属的抗性,其中转基因烟草抗Cd能力最强,并且转基因烟草的T1代种子在Cd处理的情况下萌发状况明显优于对照。这些结果说明BjPCS1基因在利用基因工程改良植物抗重金属能力和净化环境污染方面,具有良好的应用前景。 相似文献
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Eduardo Martínez-Morillo María García-García María Angeles Luengo Concha Luis Rello Varas 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2021,31(1)
IntroductionThe accurate estimation of low-density lipoprotein cholesterol (LDL) is crucial for management of patients at risk of cardiovascular events due to dyslipidemia. The LDL is typically calculated using the Friedewald equation and/or direct homogeneous assays. However, both methods have their own limitations, so other equations have been proposed, including a new equation developed by Sampson. The aim of this study was to evaluate Sampson equation by comparing with the Friedewald and Martin-Hopkins equations, and with a direct LDL method.Materials and methodsResults of standard lipid profile (total cholesterol (CHOL), high-density lipoprotein cholesterol (HDL) and triglycerides (TG)) were obtained from two anonymized data sets collected at two laboratories, using assays from different manufacturers (Beckman Coulter and Roche Diagnostics). The second data set also included LDL results from a direct assay (Roche Diagnostics). Passing-Bablok and Bland-Altman analysis for method comparison was performed.ResultsA total of 64,345 and 37,783 results for CHOL, HDL and TG were used, including 3116 results from the direct LDL assay. The Sampson and Friedewald equations provided similar LDL results (difference ≤ 0.06 mmol/L, on average) at TG ≤ 2.0 mmol/L. At TG between 2.0 and 4.5 mmol/L, the Sampson-calculated LDL showed a constant bias (- 0.18 mmol/L) when compared with the Martin-Hopkins equation. Similarly, at TG between 4.5 and 9.0 mmol/L, the Sampson equation showed a negative bias when compared with the direct assay, which was proportional (- 16%) to the LDL concentration.ConclusionsThe Sampson equation may represent a cost-efficient alternative for calculating LDL in clinical laboratories. 相似文献
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目的:用高效液相色谱法测定氨苄西林胶囊的含量。方法:采用Diamond ODS C18柱(150×4.6mm,5um);流动相A为12%醋酸溶液-0.2mol/L磷酸二氢钾溶液-乙腈-水(0.5:50:50:900)流动相B为12%醋酸溶液-0.2mol/L磷酸二氢钾溶液-乙腈-水(0.5:50:400:550),以流动相A-流动相B(85:15)为流动相;流速1.0ml/min;检测波长254nm;柱温40℃。结果:氨苄西林的线性范围为7.382～366.4μg/ml,r=0.9996,回收率为98.74%(RSD=0.6%)。结论:本法方便、快速、准确,可用于氨苄西林胶囊的质量控制。 相似文献
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Haseeb Ahmad Khan Samia Hasan Sobki Abdullah Saleh Alhomida Shaukat Ali Khan 《Indian journal of clinical biochemistry : IJCB》2007,22(1):65-70
This study reports the utilization of serum fructosamine and blood glucose for the screening of gestational diabetes mellitus
(GDM). Blood samples from 165 pregnant women were analyzed for fasting blood glucose (FBG), random blood glucose (RBG) and
serum fructosamine. The actual fructosamine levels were corrected for serum protein (c-Fruct) for more precise presentation.
Two cut-off values of FBG (>5.3 mmol/L and >7.0 mmol/L) and RBG (>7.8 mmol/L and >11.0 mmol/L) were used to classify hyperglycemic
subjects for subsequent evaluation. The average values±standard deviations for FBG, RBG and cFruct were 5.865±1.95, 7.767±3.21
and 2.387±0.47 mmol/L, respectively. FBG levels were significantly correlated with RBG (Pearson correlation=0.597, P<0.001).
Significant correlations were also observed between cFruct and FBG (Pearson correlation=0.673, P<0.001) or RBG (Pearson correlation=0.641,
P<0.001). Out of 165 subjects, 24 (14.5%) cases were classified as hyperglycemic on the basis of FBG>7.0 mmol/L or RBG>11.0
mmol/L; use of lower cut-off values resulted higher frequencies of hyperglycemia. Whereas, a combined criteria of FBG>5.3
mmol/L and cFruct >2.5 mmol/L predicted 35 patients as the most probable hyperglycemic as compared to 32 patients identified
using the criteria of RBG >7.8 mmol/L and cFruct >2.5 mmol/L. These criteria were associated with 4.8% and 3.6% false-positivity
at the expense of 3.6% and 3.0% false-negative outcomes, respectively. The levels of FBG, RBG and cFruct were significantly
higher in hyperglycemic groups (irrespective of grouping criteria) as compared to the respective normal groups. In conclusion,
these findings clearly indicate that the paired values of cFruct with FBG or RBG could help in filtering high-risk individuals
for OGTT and therefore avoiding a unnecessary OGTT. 相似文献
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重金属离子Cd Hg Pb在鳗鱼体内残留规律研究 总被引：3，自引：0，他引：3
研究了0.005、0.05、0.10和0.15/mg/L四种不同浓度的Cd与0.10mg/LPb,0.05mg/LHg在日本鳗鱼肝脏、腮、鱼血和鱼肉的残留规律。分别将鳗鱼暴露于上述浓度的重金属35 d后再用清水喂养43 d,考察鳗鱼对该三种重金属的吸收和清除规律。结果显示三种重金属在鳗鱼体内富集能力依次是Hg>Pb>Cd。Cd在鳗鱼组织中蓄积顺序为肝脏>腮>鱼肉>血。鳗鱼体内Cd的吸收量与其暴露浓度呈正相关,停止暴露后Cd由其他组织向肝脏转移,可导致肝脏Cd负担持续增大。0.15mg/L浓度的Cd可使鳗鱼产生急性和亚急性中毒症状。鳗鱼组织中Hg和Pb蓄积顺序为腮>肝脏>鱼肉>血。鱼肉中两种重金属消除速度非常缓慢。 相似文献
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目的：建立注射用维库溴铵有关物质的检测方法。方法：采用反相HPLC法,色谱柱为Agilent EclipseXD（BC-18,250×4.6mm,5μm）,流动相为：pH为6.5的18.0g·L^-1的四甲基氢氧化铵的溶液-甲醇-乙腈（50：250：700）,流速1.5ml·min-1,柱温40℃,进样量20μL,检测波长为210nm。稀释剂：乙腈：0.01mol·L^-1盐酸溶液（1：1）;结果：杂质A、杂质C和杂质E的检测限都为0.007%、杂质D和维库溴铵的检测限为0.006%,定量限为0.02%,柱温、流速、流动相比例经过微小变化不影响检测结果。结论：本方法灵敏度高,准确度高,可用于注射用维库溴铵有关物质的检测。 相似文献
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The effects of global warming, pollution in river effluents, and changing ocean currents can be studied by characterizing variations in phytoplankton populations. We demonstrate the design and fabrication of a Microflow Cytometer for characterization of phytoplankton. Guided by chevron-shaped grooves on the top and bottom of a microfluidic channel, two symmetric sheath streams wrap around a central sample stream and hydrodynamically focus it in the center of the channel. The lasers are carefully chosen to provide excitation light close to the maximum absorbance wavelengths for the intrinsic fluorophores chlorophyll and phycoerythrin, and the excitation light is coupled to the flow cytometer through the use of an optical fiber. Fluorescence and light scatter are collected using two multimode optical fibers placed at 90-degree angles with respect to the excitation fiber. Light emerging from these collection fibers is directed through optical bandpass filters into photomultiplier tubes. The cytometer measured the optical and side scatter properties of Karenia b., Synechococcus sp., Pseudo-Nitzchia, and Alexandrium. The effect of the sheath-to-sample flow-rate ratio on the light scatter and fluorescence of these marine microorganisms was investigated. Reducing the sample flow rate from 200 μL/min to 10 μL/min produced a more tightly focused sample stream and less heterogeneous signals. 相似文献
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Manipulating and discriminating biological cells of interest using microfluidic and micro total analysis system (μTAS) devices have potential applications in clinical diagnosis and medicine. Cellular focusing in microfluidic devices is a prerequisite for medical applications, such as cell sorting, cell counting, or flow cytometry. In the present study, an insulator-based dielectrophoretic microdevice is designed for the simultaneous filtration and focusing of biological cells. The cells are introduced into the microchannel and hydrodynamically pre-confined by funnel-shaped insulating structures close to the inlet. There are ten sets of X-patterned insulating structures in the microfluidic channel. The main function of the first five sets of insulating structures is to guide the cells by negative dielectrophoretic responses (viable HeLa cells) into the center region of the microchannel. The positive dielectrophoretic cells (dead HeLa cells) are attracted to regions with a high electric-field gradient generated at the edges of the insulating structures. The remaining five sets of insulating structures are mainly used to focus negative dielectrophoretic cells that have escaped from the upstream region. Experiments employing a mixture of dead and viable HeLa cells are conducted to demonstrate the effectiveness of the proposed design. The results indicate that the performance of both filtration and focusing improves with the increasing strength of the applied electric field and a decreasing inlet sample flow rate, which agrees with the trend predicted by the numerical simulations. The filtration efficiency, which is quantitatively investigated, is up to 88% at an applied voltage of 50 V peak-to-peak (1 kHz) and a sample flow rate of 0.5 μl/min. The proposed device can focus viable cells into a single file using a voltage of 35 V peak-to-peak (1 kHz) at a sample flow rate of 1.0 μl/min. 相似文献
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Gabriel Lima-Oliveira Giuseppe Lippi Gian Luca Salvagno Martina Montagnana Geraldo Picheth Gian Cesare Guidi 《Biochemia medica : ?asopis Hrvatskoga dru?tva medicinskih biokemi?ara / HDMB》2013,23(2):218-223
Procedures involving phlebotomy are critical for obtaining diagnostic blood specimens and represent a well known and recognized problem, probably among the most important issues in laboratory medicine. The aim of this report is to show spurious hyperkalemia and hypocalcemia due to inadequate phlebotomy procedure. The diagnostic blood specimens were collected from a male outpatient 45 years old, with no clinical complaints. The tubes drawing order were as follows: i) clot activator and gel separator (serum vacuum tube), ii) K3EDTA, iii) a needleless blood gas dedicated-syringe with 80 I.U. lithium heparin, directly connected to the vacuum tube holder system. The laboratory testing results from serum vacuum tube and dedicated syringe were 4.8 and 8.5 mmol/L for potassium, 2.36 and 1.48 mmol/L for total calcium, respectively. Moreover 0.15 mmol/L of free calcium was observed in dedicated syringe. A new blood collection was performed without K3EDTA tube. Different results were found for potassium (4.7 and 4.5 mmol/L) and total calcium (2.37 and 2.38 mmol/L) from serum vacuum tube and dedicated syringe, respectively. Also free calcium showed different concentration (1.21 mmol/L) in this new sample when compared with the first blood specimen. Based on this case we do not encourage the laboratory managers training the phlebotomists to insert the dedicated syringes in needle-holder system at the end of all vacuum tubes. To avoid double vein puncture the dedicated syringe for free calcium determination should be inserted immediately after serum tubes before EDTA vacuum tubes. 相似文献