CdTe/CdS-罗丹明体系用于铅离子（Ⅱ）的测定

目的建立以CdTe/CdS-RhB荧光共振能量转移体系为荧光探针,设计出一种快速、超灵敏且高选择性的检测Pb（Ⅱ）含量的方法。方法研究CdTe/CdS和罗丹明B（受体）之间FRET的最佳条件利用,Pb2＋能对能量转移体系中CdTe/CdS的荧光峰强产生猝灭作用从而测定Pb2＋的含量。结果在3.85×10-10～9.62×10-9mol.L-1线性关系良好,相关系数r为0.997 5。9组浓度为3.85×10-9mol.L-1的Pb（Ⅱ）对量子点-罗丹明体系荧光猝灭的相对标准偏差（RSD）为0.32%。将该方法用于测定菠菜和柑橘叶中Pb（Ⅱ）的含量分别为69.6和55.2μmol.kg-1,与火焰原子吸收光谱法比较无显著性差异。结论该体系作为荧光探针测定Pb（Ⅱ）简便经济可行,灵敏度高,选择性好。     

药物酚磺乙胺在MnO_2/离子液体复合电极上的电化学行为研究及测定

目的:制备[BMIM]PF6-MnO2-CHIT/GCE修饰电极,研究酚磺乙胺(ETH)在该电极上的电化学行为及其测定方法。方法:循环伏安法和微分脉冲伏安法。结果:ETH在[BMIM]PF6-MnO2-CHIT/GCE上的循环伏安图上出现1对灵敏、可逆的氧化还原峰,其氧化峰电流响应是其在MnO2-CHIT/GCE上的2.8倍,峰电位差降低到0.029 V,电子转移速率常数Ks=0.283 s-1。ETH在[BMIM]PF6-MnO2-CHIT/GCE上的微分脉冲伏安扫描峰电流与其浓度在5.0×10-7~5.0×10-4mol.L-1范围内呈良好的线性关系,检出限为5.0×10-8mol.L-1。连续5次测定1.0×10-5mol.L-1酚磺乙胺溶液的RSD为1.8%。结论:本法可靠、快捷、灵敏,可用于酚磺乙胺注射液中酚磺乙胺含量的电化学定量测定,结果满意。     

依托度酸的平行催化氢波法分析

目的:建立平行催化氢波测定依托度酸的新方法。方法:用氧化剂存在时依托度酸产生的极谱催化波提高分析灵敏度,用线性单扫描极谱法实现快速测定。结果:在磷酸二氢钾-磷酸氢二钠(pH5.5±0.1)支持电解质中,依托度酸产生一催化氢波,峰电位Ep=-1.23V。当1.0×10-2mol.L-1过氧化氢存在时,该催化氢波被催化,峰电流增加10倍,峰电位基本不变,产生一较灵敏的平行催化氢波。其二阶导数峰峰电流i″p与依托度酸浓度在2.0×10-7～6.0×10-5mol.L-1范围内呈线性关系(r=0.9987),检出限为1.0×10-7mol.L-1。结论:该方法可用于药物制剂中依托度酸含量的测定。     

流动注射-化学发光检测利福平

目的:建立一种流动注射-化学发光测定利福平的快速、灵敏新方法。方法:碱性条件下,利福平对luminol-KIO4化学发光体系有抑制作用,结合流动注射技术,建立了流动注射-化学发光检测利福平的新方法。结果:在优化条件下,利福平的线性范围是7.0×10-9～6.0×10-7 mol.L-1,检出限达3.2×10-9 mol.L-1。对3.0×10-8 mol.L-1和2.0×10-7mol.L-1利福平分别进行11次测定,相对标准偏差分别为0.8%和1.6%。分析速度为128个样品/时。将提出的新方法成功应用于利福平滴眼液和利福平胶囊中利福平含量的测定。结论:本方法操作简单快速,适合于利福平的分析。     

美托洛尔片的离子选择电极法测定

目的:建立用聚氯乙烯(PVC)膜美托洛尔电极测定美托洛尔片含量的方法.方法:利用该电极对美托洛尔的响应,测定美托洛尔片含量.结果:电极的Nernst响应范围为1.0×10-2～3.2×10-5mol·L-1,级差为30 mV/pC,检出限为2.0 × 10-5mol·L-1.结论:聚氯乙烯膜电极法可简便、快速、准确地检测片剂中美托洛尔的含量.     

L-半胱氨酸包覆的ZnS:Mn~(2+)水溶性的量子点荧光探针测定氟尿嘧啶的含量

目的:以绿色环保材料为基础,在温和的条件下合成了水溶性的L-半胱氨酸包覆的锰离子掺杂的硫化锌量子点(L-Cys/ZnS:Mn2+QDs),并以此为荧光探针建立了测定抗癌药物氟尿嘧啶(FU)的新方法。方法:研究了FU对L-Cys/ZnS:Mn2+QDs荧光的淬灭作用并阐述了可能的作用机理。实验还考察了缓冲液体系、pH、反应时间、量子点浓度等多种因素对测定FU的影响。结果:在磷酸盐(pH6.5)缓冲溶液中,L-Cys/ZnS:Mn2+QDs浓度为1.6×10-4mol.L-1时,FU在1.0~85μg.mL-1的浓度范围内对量子点的荧光强度有较强的猝灭作用,且体系的荧光强度变化与溶液中氟尿嘧啶的浓度符合斯特恩方程,线性方程为:Y=0.01059C+0.9757(r=0.9988);猝灭常数为1.377×103L.mol-1;检出限为0.38μg.mL-1。将方法应用于实际样品FU注射液的分析,获得满意结果,FU的加样回收率为99.2%~100.0%。结论:该法简便、快速、灵敏度高,可望将其作为一种新型的荧光标记物用于体内药物的示踪和测定。     

鲁米诺-Ag(Ⅲ)化学发光新体系用于石杉碱甲的测定

目的:建立测定石杉碱甲的流动注射化学发光法。方法:在碱性介质中,石杉碱甲对鲁米诺-Ag(Ⅲ)化学发光体系有显著的增敏作用,建立了化学发光检测石杉碱甲的新方法。结果:在优化的条件下,石杉碱甲浓度在1.0×10-8～5.0×10-7mol·L-1范围内与化学发光强度呈线性关系;对浓度为2.0×10-7 mol·L-1的石杉碱甲溶液11次平行测定的RSD为2.6%;检出限为8.0×10-9 mol·L-1。结论:该方法简单、快速、灵敏,适用于药物制剂中石杉碱甲的含量测定。     

谷胱甘肽在咖啡酸修饰碳糊电极上的电催化氧化及电分析方法

目的:研究了谷胱甘肽(还原型,glutathione,GSH)在咖啡酸(Caffeic acid,CFA)修饰碳糊电极(CFA/CPE)上的电催化氧化行为和电化学分析方法。方法:循环伏安法(CV),计时电流法(CA)和线性扫描伏安法(LSV)。结果:GSH在碳糊电极(CPE)上的直接电化学氧化过程十分迟缓,CFA/CPE对GSH电化学氧化具有良好的催化作用。同时测定了GSH在CFA/CPE上的电极过程动力学参数,用LSV法测得催化氧化峰电流与GSH在5.0×10-5～1.0×10-3 mol.L-1浓度范围内呈良好线性关系,线性回归方程为Ipa(μA)=2.003c(10-3 mol.L-1)+3.448,r=0.9989,检出限为4.0×10-5 mol.L-1。结论:CFA/CPE对GSH电化学氧化具有良好的催化作用,该方法可用于市售还原型谷胱甘肽药物含量的电化学定量测定。     

基于纳米金催化鲁米诺-氯化汞化学发光新体系测定木犀草素

目的:基于纳米金对鲁米诺-氯化汞化学发光体系有良好的催化作用,建立测定木犀草素含量的高灵敏流动注射-化学发光分析法。方法:采用流动注射技术,实验研究了影响化学发光的各种因素;根据体系的化学发光光谱和紫外-可见吸收光谱结果,探讨了可能的化学发光机理。结果:0.1 mol·L-1氢氧化钠、4.0×10-4 mol·L-1鲁米诺、6.08×10-5 mol·L-1纳米金与1.0×10-3 mol·L-1 HgCl2组成最优的化学发光体系。在优化的实验条件下,本方法测定木犀草素的线性范围为2.0×10-9～1.0×10-7 g·mL-1(r=0.9929),检出限为1.5×10-9 g·mL-1,RSD为2.1%(C=1.0×10-8 g·mL-1,n=11)。纳米金作为电子转移的媒介,在鲁米诺-氯化汞反应过程中起催化作用;木犀草素和鲁米诺竞争与氯化汞发生反应,抑制了鲁米诺氧化成鲁米诺自由基,导致发光强度的降低。结论:利用本法成功地测定了血清与合成样品中木犀草素的含量。     

碳糊电极法测定美托洛尔片中的美托洛尔

目的建立用碳糊美托洛尔电极测定美托洛尔片含量的方法。方法利用该电极对美托洛尔的响应,测定美托洛尔片的含量。结果电极的Nernst响应范围为0.01～5.0×10-6 mol.L-1,级差为30.2 mV.pC-1,检出限为3.2×10-6 mol.L-1。结论碳糊美托洛尔电极法可简便、快速、准确地检测片剂中美托洛尔的含量。     

Efficacy of gut lavage,hemodialysis, and hemoperfusion in the therapy of paraquat or diquat intoxication

Clinical and in vitro investigations were carried out to test the efficacy of gut lavage, hemodialysis, and hemoperfusion in the treatment of poisoning with paraquat or diquat. In a patient suffering from diquat intoxication 130 times more diquat was removed by gut lavage 30 h after ingestion than was removed by complete aspiration of the gastric contents.Determination of in vitro clearances for paraquat and diquat by hemodialysis showed that, at serum concentrations of 1–2 ppm, such as are frequently encountered in poisoning in man, toxicologically relevant quantities of herbicide cannot be removed from the body. At a concentration of 20 ppm, on the other hand, hemodialysis proved to be effective, the clearance being 70 ml/min at a blood flow rate of 100 ml/min. The efficacy of hemoperfusion with coated activated charcoal was on the whole better. Especially at concentrations around 1–2 ppm, the clearance values for hemoperfusion were some 5–7 times higher than those for hemodialysis.In a patient suffering from paraquat poisoning, both hemodialysis as well as hemoperfusion were carried out. The in vitro results could be confirmed: At serum concentrations of paraquat less than 1 ppm no clearance could be obtained by hemodialysis while by hemoperfusion with activated charcoal quite high clearance values were measured and the serum level dropped down to zero.

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Zusammenfassung Klinische Untersuchungen und Laboratoriumsversuche wurden durchgeführt, um die Wirksamkeit von Darmspülung, Hämodialyse und Hämoperfusion bei Paraquat- und Deiquat-Vergiftungen zu prüfen.Bei einem Patienten wurde 30 Std nach Deiquat-Aufnahme durch Darmspülung 130mal mehr Deiquat entfernt als durch vollständige Aspiration des Mageninhaltes. In vitro-Versuche ergaben, daß bei Blutserumkonzentrationen von 1–2 ppm, die bei Vergiftungen oft gemessen werden, durch Hämodialyse keine toxikologisch relevanten Paraquat- oder Deiquat-Mengen entfernt werden können. Dagegen erwies sich die Hämodialyse bei 20 ppm und einer Blutumlaufgeschwindigkeit von 100 ml/min mit einer Clearance von 70 ml/min als wirksam. Die Hämoperfusion mit beschicheter Aktivkohle war in diesen Versuchen aber eindeutig überlegen, denn insbesondere bei Konzentrationen um 1–2 ppm waren die Clearance-Werte 5–7mal höher als bei der Hämodialyse.Die in vitro-Ergebnisse wurden bei einem Patienten mit einer Paraquat-Vergiftung bestätigt: Bei Konzentrationen unter 1 ppm war die Hämodialyse wirkungslos, während durch Hämoperfusion relativ hohe Clearance-Werte erreicht wurden, so daß der Serumspiegel rasch unter die Nachweisgrenze abfiel.

     

In vitro studies on sterically stabilized liposomes (SL) as enzyme carriers in organophosphorus (OP) antagonism

This study describes a new approach for organophosphorous (OP) antidotal treatment by encapsulating an OP hydrolyzing enzyme, OPA anhydrolase (OPAA), within sterically stabilized liposomes. The recombinant OPAA enzyme was derived from Alteromonas strain JD6. It has broad substrate specificity to a wide range of OP compounds: DFP and the nerve agents, soman and sarin. Liposomes encapsulating OPAA (SL)* were made by mechanical dispersion method. Hydrolysis of DFP by (SL)* was measured by following an increase of fluoride ion concentration using a fluoride ion selective electrode. OPAA entrapped in the carrier liposomes rapidly hydrolyze DFP, with the rate of DFP hydrolysis directly proportional to the amount of (SL)* added to the solution. Liposomal carriers containing no enzyme did not hydrolyze DFP. The reaction was linear and the rate of hydrolysis was first order in the substrate. This enzyme carrier system serves as a biodegradable protective environment for the recombinant OP-metabolizing enzyme, OPAA, resulting in prolongation of enzymatic concentration in the body. These studies suggest that the protection of OP intoxication can be strikingly enhanced by adding OPAA encapsulated within (SL)* to pralidoxime and atropine.     

Aquatic Insects and Trace Metals: Bioavailability,Bioaccumulation, and Toxicity

Abstract

The uptake of metals from food and water sources by insects is thought to be additive. For a given metal, the proportions taken up from water and food will depend both on the bioavailable concentration of the metal associated with each source and the mechanism and rate by which the metal enters the insect. Attempts to correlate insect trace metal concentrations with the trophic level of insects should be made with a knowledge of the feeding relationships of the individual taxa concerned. Pathways for the uptake of essential metals, such as copper and zinc, exist at the cellular level, and other nonessential metals, such as cadmium, also appear to enter via these routes. Within cells, trace metals can be bound to proteins or stored in granules. The internal distribution of metals among body tissues is very heterogeneous, and distribution patterns tend to be both metal and taxon specific. Trace metals associated with insects can be both bound on the surface of their chitinous exoskeleton and incorporated into body tissues. The quantities of trace meals accumulated by an individual reflect the net balance between the rate of metal influx from both dissolved and particulate sources and the rate of metal efflux from the organism. The toxicity of metals has been demonstrated at all levels of biological organization: cell, tissue, individual, population, and community. Much of the literature pertaining to the toxic effects of metals on aquatic insects is based on laboratory observations and, as such, it is difficult to extrapolate the data to insects in nature. The few experimental studies in nature suggest that trace metal contaminants can affect both the distribution and the abundance of aquatic insects. Insects have a largely unexploited potential as biomonitors of metal contamination in nature. A better understanding of the physico-chemical and biological mechanisms mediating trace metal bioavailability and exchange will facilitate the development of general predictive models relating trace metal concentrations in insects to those in their environment. Such models will facilitate the use of insects as contaminant biomonitors.     

Pharmacological treatment of COVID-19: an opinion paper

The precocity and efficacy of the vaccines developed so far against COVID-19 has been the most significant and saving advance against the pandemic. The development of vaccines has not prevented, during the whole period of the pandemic, the constant search for therapeutic medicines, both among existing drugs with different indications and in the development of new drugs. The Scientific Committee of the COVID-19 of the Illustrious College of Physicians of Madrid wanted to offer an early, simplified and critical approach to these new drugs, to new developments in immunotherapy and to what has been learned from the immune response modulators already known and which have proven effective against the virus, in order to help understand the current situation.     

Steroidal sapogenin contents in some domestic plants

In order to find out the values of the steroid resources for the future use. the compositions and contents of steroidal sapogenins from 13 domestic plants have been investigated. As a result,Dioscorea nipponica, D. quinqueloba andSmilax china were found to have large amount of diosgenin. And pennogenin inTrillium kamtschaticum andParis verticillata, yuccagenin inAllium fistulosum, hecogenin inAgave americana and neochlorogenin inSolanum nigum were appeared to be major steroidal sapogenins.     

Alzheimer’s disease – current trends in basic and clinical research. Highlights from the 16th ECNP

Advances in the molecular biological knowledge of neuronal nicotinic acetylcholine receptors (nAChRs) have led to a growing interest by the pharmaceutical industry in the development of novel compounds that selectively modulate nAChR function. The ability of (-)-nicotine, an activator of nAChRs, to enhance attentional aspects of cognition in animals and humans, to exert neuroprotective and anxiolytic-like effects, and presumably to mediate the negative correlation between smoking and Alzheimer's (and Parkinson's) Disease, has focused interest on the potential therapeutic utility of modulators of nAChR function for treatment of some of the deficits associated with these progressive, neurodegenerative conditions. Numerous compounds are known which activate nAChRs and which might serve as lead compounds toward the development of such agents. The pharmacologic diversity of neuronal nAChR subtypes suggests the possibility of developing selective compounds which would have more favourable side-effect profiles than existing agents. This broader class of agents, collectively called cholinergic channel modulators (ChCMs), is anticipated to encompass compounds which would have more favourable side-effect profiles than existing agents, which generally exhibit low selectivity. This selectivity may be achieved by preferentially activating some subtypes of nAChRs (i.e., Cholinergic Channel Activators, ChCAs) or inhibiting the function of other subtypes (Cholinergic Channel Inhibitors, ChCIs). An overview of the biology of nAChRs and the rationale for the use of ChCMs for the treatment of dementia related to neurodegenerative diseases are presented, followed by a discussion of lead compounds and compounds under consideration for clinical evaluation.