高效液膜法分离富集钼（VI）与钨精矿中痕量钼的测定

用ＴＢＰ－ＴＯＰＯ（协同载体）Ｎ１１３Ｃ（表面活性剂）液体石蜡（增强剂）煤油（溶剂）和内相（１ｍｏｌ／ＬＮａＯＨ水溶液）乳状液膜体系，研究了钼（ＶＩ）的迁移富集行为，确定了用此液膜迁移分离钼（ＶＩ）的最适宜实验条件。钼（Ⅵ）在２０ｍｉｎ可迁移速率达９９．６５％以上，在同样条件下，一些共存金属离子如Ｗ＾６＋，Ｆｅ＾３＋，Ａｌ＾３＋，Ｃａ＾２＋，Ｍｇ＾２＋，Ｍｎ＾２＋，Ｐｂ＾２＋，Ｚｎ＾２＋，Ｃｕ＾２     

液膜分离富集CN^—与测定水中氰化物

用ＴＢＰ－ＰＭＢＰ、ＳＰＡＮ８０、液体石蜡、煤油和内相（２％ＮａＯＨ溶液）乳状液膜，研究了ＣＮ＾－的迁移行为及最适宜的实验条件。ＣＮ＾－在１５ｍｉｎ内可以迁移９９．５％以上。在此情况下许多共存离子，如Ｍｏ＾６＋、Ｍｏ＾５＋、Ｆｅ＾３＋、Ａｌ＾３＋、Ｃａ＾２＋、Ｍｇ＾２＋、Ｓｒ＾２＋、Ｂａ＾２＋、ΣＲＥ＾３＋、Ａｇ＾２＋、Ｐｄ＾２＋、Ｐｔ＾４＋、Ｒｈ＾３＋、Ｃｕ＾２＋、Ｐｂ＾２＋、Ｚｎ＾２＋、Ｗ＾６     

液膜法分离富集测定钢中痕量铅

用２，６－二酮吡啶－１８－王冠－６（２－６－ＤＫＰ－１８－Ｃｒｏｗｅ－６），ＳＰＡＮ８０，Ｓ１００Ｎ－Ｉ（中性油）和Ｃ２Ｈ２Ｃｌ４乳状液膜体系，研究了Ｐｂ６２＋的迁移行为。在适宜条件下，８ｍｉｎ内Ｐｂ＾２＋的迁移率达９９．５％以上，而而这种情况下，许多金属离子如Ｆｅ＆３＋，Ｎｉ＾２＋，Ｃｒ＾３＋，Ｌｉ＾＋，∑ＲＥ＾３＋，Ｋ＾＋，Ｎａ＾＋，Ｃａ＾２＋，Ｍｇ＾２＋，Ｂａ６２＋，Ｓｒ＾２＋，Ａｌ＾３＋，     

某些阳离子通过离子交换膜的迁移特性

本文研究了低浓度的重金属离子ＺＮ＾２＋、Ｎｉ＾２＋、Ｃｕ＾２＋及Ｈ＾＋在浓度差和电场作用下通过阳离子交换膜的迁移行为,以表以迁移速率（Ｊ）表征不同离子在各种条件下的管移特性。文中还以四对阳膜和阴膜组成的微型电渗析器进行了从稀溶液中浓度Ｃｕ＾２＋的试验,效果较好。     

液膜法从湿法炼锌系统是提取镓的研究

对利用液膜法从湿法炼锌系统中分离提取镓的工艺进行了系统研究，确定了分离提取镓的最佳液膜条件。结果表明，在最佳条件下Ｇａ＾３＋的迁移率为９８．５％，内水相可富集近１０００保，Ｚｎ＾２＋、Ｃｕ＾２＋、Ｇｅ＾４＋及Ｆｅ＾３＋等杂质对Ｇａ＾３＋的迁移影响很小。     

金属阳离子对含金黄铁矿浮选的影响及消除方法的研究

矿浆中难免的金属离子Ｃｕ＾２＋、Ｆｅ＾２＋、Ｆｅ＾３＋在达到一定浓度时，会严重抑制含金黄铁矿的浮选。腐植酸钠可用来络合Ｃｕ＾２＋、Ｆｅ＾２＋、Ｆｅ＾３＋完全消除这些金属离子对含金黄铁矿浮选的影响。     

I^——EDTA—Cu^2＋体系在分析化学中的应用

本文采用Ｐｔ／Ｉ２／Ｉ＾－电极电位滴定法，系统地研究了，Ｉ＾－－ＥＤＴＡ－Ｃｕ＾２＋体系在不同条件下的化学平衡，提出了用Ｃｕ＾２＋盐返滴法和Ｎａ２Ｓ２Ｏ３滴定法测定Ｎｉ＾２＋、Ｓｎ＾４＋等金属离子的新方法，为多元素（如Ｃｕ－Ｓｎ、Ｃｕ－Ｎｉ、Ｃｕ－Ｎｉ－Ｆｅ等）连续测定提供了新途径。     

用Oxine作释放剂选择性螯合滴定法测定钙镁

干扰离子如Ｆｅ３＋、Ａｌ３＋、Ｃｕ２＋、Ｎｉ２＋、Ｚｒ４＋、Ｚｎ２＋、Ｍｏ６＋、Ｃｄ２＋、Ｐｂ２＋、Ｍｎ２＋等，用适量Ｔａｒｔｒａｔｅ、ＴＥＡ、ＤＬ－Ｃｙｓｔｅｉｎｅ掩蔽。在ｐＨ１０左右，用ＥＤＴＡ滴定Ｃａ２＋、Ｍｇ２＋，确定合量。然后加入Ｏｘｉｎｅ分解Ｍｇ－ＥＤＴＡ螯合物，释放出的ＥＤＴＡ用Ｃａ２＋标准溶液滴定。用ＭＴＢ－ＸＯ－ＣＰＢ为混合指示剂，终点颜色变化敏锐，一般常见金属离子均不干扰。该法已用于测定水和工业废水中钙镁含量，结果十分满意     

液膜法分离富集测定水中痕量镉

用ＨＥＨＥＨＰ、ＴＯＰＯ、ＳＰＡＮ８０、液体石蜡、煤油和内相乳状液膜体系，研究了Ｃｄ＾２＋的迁移行为，只有Ｃｄ＾２＋能与各种阳离子得到满意的分离。最佳液膜体系的体积比为４％ＨＥＨＥＨＰ、３％ＴＯＰＯ、５％ＳＰＡＮ８０、４％液体石蜡、８４％煤油，内相为３ｍｏｌ／Ｌ ＨＣｌ溶液。同时还确定了分离富集Ｃｄ＾２＋的最优实验条件，经法用于水和工业废水中痕量镉，其加嘏率为９９．４％以上，相对标准偏差在３．８％     

铜精矿中金属元素的快速分析法

本文应用Ｐｔ／Ｉ２／Ｉ＾－为指示电极，以Ｎａ２Ｓ２Ｏ３为滴定剂，连续测定了铜精矿中Ｃｕ－Ｆｅ－Ｎｉ。文章重点研究了在Ｃｕ＾２＋、Ｆｅ＾３＋、Ｎｉ＾２＋、Ｃｏ＾２＋、Ａｌ＾３＋、Ｉ＾－、ＥＤＴＡ共存的复杂体系中测定Ｎｉ＾２＋的条件，以及用Ｐｔ／Ｉ２／Ｉ＾－电极连续指示滴定终点的原理和实验条件。     

高铼酸铵除铊试验研究

从铜冶炼污酸中提取的高铼酸铵含有一定量的Tl元素, 影响高铼酸铵品质及制约铼产品的末端应用.文中采用传统的吸附法进行除Tl, 用活性炭、TiO₂、KI与XH30树脂进行静态吸附探索性试验; 在此基础上, 考察了铼液浓度、吸附线速度、铼液pH对XH30树脂动态吸附Tl的影响.结果表明, 活性炭与KI对Tl吸附效果不理想; TiO₂与XH30树脂长时间动态吸附Tl的吸附率分别达96.9 %、97.95 %; 用XH30树脂装柱吸附Tl, 当铼液Re为10 g/L, 铼液Tl约为5 mg/L, pH值为8.5时, 控制吸附线速度为8 cm/min, Tl去除率稳定在93.4 %, 铼液经重结晶后高铼酸铵品位稳定在99.99 %以上.      

Cognitive load, schema acquisition, and procedural adaptation in nonisomorphic analogical transfer.

Cognitive load theory was explored in 3 conditions among 96 3rd graders in nonisomorphic transfer. In 1 condition, both goal attainment and problem-space exploration were emphasized on each acquisition trial. In a 2nd condition, problem-space exploration was emphasized, whereas goal attainment was not. In a 3rd condition, goal attainment was emphasized, but the problem-space was explored only until an error occurred on each trial. All children solved 2 analogs of the missionaries/cannibals problem and transferred to an analog of the jealous husbands problem. Children in the 2nd condition made fewer errors and required less time than the other groups on the 1st move in transfer, which is taken to reflect the quality of the base attained during acquisition. On later moves, children in Conditions 1 and 2 outperformed those in Condition 3. Thus, children in the 1st 2 conditions were better able to adjust the base to the target. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Thallium-201 scintigraphy to predict therapeutic outcome of iodine-131 therapy of metastatic thyroid carcinoma

We studied the relationship between 201Tl uptake and the efficacy of radioiodine therapy in thyroid carcinoma. METHODS: Forty-four patients with metastases of well-differentiated thyroid carcinoma received 201Tl scintigraphy within the 2 mo before their initial 131I therapy. Patients were classified into two groups according to the tumor-to-background (T/B) ratio on the late 201Tl scan: high 201Tl uptake (T/B > or = 2.1) and low 201Tl uptake (T/B < 2.1). The therapeutic outcome was judged by the percent reduction in the tumor diameter at 6 mo after the treatment. The treatment was defined as effective when the tumor showed more than 50% reduction in the tumor diameter. The patients in whom radioiodine was ineffective were followed up to determine if the tumor showed further growth. RESULTS: Of the 44 patients, 25 had high 201Tl uptake and 19 had low 201Tl uptake. The therapy was effective in 15 patients and was ineffective in 29. All the patients in whom radioiodine was effective had low 201Tl uptake. On the other hand, 25 of 29 patients in whom radioiodine was ineffective had high 201Tl uptake. Eight patients, in whom radioiodine was ineffective despite good 131I uptake, had high 201Tl uptake. There were no significant differences in the positive predictive value and the negative predictive value for effective treatment between 201Tl scintigraphy and therapeutic dose 131I scintigraphy. Among the 25 patients in whom radioiodine was ineffective and who had high 201Tl uptake, the tumor diameter increased in 7 (28%). However, none of the tumors with low 201Tl uptake increased in size during the follow-up period. CONCLUSION: Thallium-201 scintigraphy has a high predictive value for the efficacy of radioiodine therapy in metastatic thyroid carcinoma. Thus, it is helpful in determining the indication for radioiodine therapy and it seems to be an adjunct to tracer dose 131I scintigraphy.     

Conformational changes in yeast pyruvate kinase studied by 205Tl+ NMR

The interaction of the monovalent cation with yeast pyruvate kinase (yPK) has been investigated by 205Tl+ NMR. TlNO3 activates yPK to 80-90% activity compared to KCl with an apparent Ka of 1.00 +/- 0.03 mM in the presence of 4 mM Mn(NO3)2 as the activating divalent cation. At higher concentrations of Tl+, enzyme inhibition is observed with an apparent KI of 180 +/- 10 mM. The extent of inhibition is dependent on the nature and concentration of the divalent cation. The effect of Mn2+ on the 1/T1 and 1/T2 values of 205Tl+ in the presence of yPK was determined at 173.02 MHz (300 MHz, 1H) and 346.03 MHz (600 MHz, 1H). The temperature dependence of the relaxation rates indicates that fast exchange conditions prevail for 205Tl+ longitudinal relaxation rates. The correlation time, tauc, for the Mn2+-205Tl+ interaction was estimated by a frequency dependence of 1/T1m for several enzyme complexes, and an average value of tauc was determined to be 0.91 ns. The distance between Tl+ and Mn2+ at the active site of yPK was calculated from the paramagnetic contribution of Mn2+ to the longitudinal (1/T1m) relaxation rates of Tl+ bound to yPK. For the apo yPK complex, the Tl+ to Mn2+ distance is 6.7 +/- 0.2 A. Upon addition of phosphoenolpyruvate (PEP) to form the yPK-Tl-Mn-PEP complex, the inter-cation distance decreases to 6.1 +/- 0.3 A. The addition of the allosteric activator fructose 1,6-bisphosphate (FBP) to form the yPK-Tl+-Mn2+-PEP-FBP complex gives an intermetal distance of 6.2 +/- 0.2 A. In the yPK-Tl-Mn-FBP complex, a Tl+-Mn2+ distance of 6.0 +/- 0.1 A is observed, indicating that FBP causes a conformational change at the active site in the absence of PEP. Analogous 205Tl NMR experiments with competitive inhibitors of PEP (oxalate, BrPEP) indicate that these ligands do not induce the same conformational changes as do the physiological substrates and activators. Similar experiments with the nonallosteric rabbit muscle PK were also performed and analyzed.     

罗丹明6G共振光散射法测定废水中铊

在硫酸介质中, 痕量铊(Ⅲ)与碘化钾反应生成I₃^-, I₃^-与罗丹明6G形成1∶1缔合物, 可导致共振光散射明显增强, 据此建立了共振光散射测定痕量铊的新方法。考察了它们的光谱特征:罗丹明6G溶液的共振荧光峰波长为540 nm, (Rh6G-I₃)n缔合微粒共振散射峰波长为330、420、580 nm。通过条件试验确定0.4 mL 0.2 mol/L硫酸作为反应介质、0.1 mol/L KI溶液用量为0.4 mL、1.0×10^-4 mol/L罗丹明6G 溶液用量为0.4 mL、反应时间为5 min。进一步考察发现, 在580 nm波长, 共振散射光强度增加值与溶液中铊浓度呈线性关系, 方法的线性范围为0.005～0.10 mg/L, 检出限为0.001 2 mg/L。方法应用于工业废水中铊含量的测定, 结果与ICP-MS法的对照结果基本一致, 相对标准偏差(RSD, n=6)为1.8%～3.2%。     

Importance of intramembrane carboxylic acids for occlusion of K+ ions at equilibrium in renal Na,K-ATPase

Site-directed mutagenesis and assay of Rb+ and Tl+ occlusion in recombinant Na,K-ATPase from yeast were combined to establish structure-function relationships of amino acid side chains involved in high-affinity occlusion of K+ in the E2[2K] form. The wild-type yeast enzyme was capable of occluding 2 Rb+ or Tl+ ions/ouabain binding site or alpha 1 beta 1 unit with high apparent affinity (Kd(Tl+) = 7 +/- 2 microM), like the purified Na,K-ATPase from pig kidney. Mutations of Glu327(Gln,Asp), Asp804(Asn, Glu), Asp808(Asn, Glu) and Glu779(Asp) abolished high-affinity occlusion of Rb+ or Tl+ ions. The substitution of Glu779 for Gln reduced the occlusion capacity to 1 Tl+ ion/alpha 1 beta 1-unit with a 3-fold decrease of the apparent affinity for the ion (Kd(Tl+) = 24 +/- 8 microM). These effects on occlusion were closely correlated to effects of the mutations on K0.5(K+) for K+ displacement of ATP binding. Each of the four carboxylate residues Glu327, Glu779, and Asp804 or Asp808 in transmembrane segments 4, 5, and 6 is therefore essential for high-affinity occlusion of K+ in the E2[2K] form. These residues either may engage directly in cation coordination or they may be important for formation or stability of the occlusion cavity.     

Inhibition of prolidase activity by non-steroid antiinflammatory drugs in cultured human skin fibroblasts

201-Thallium (Tl) and (99m)Tc-sestamibi (SM) present different biological properties and kinetics, suggesting a complementary evaluation of mitochondrial and cell membrane functions with subsequent implications regarding myocardial injury mapping. To verify the usefulness of a dual isotopic approach in Q infarcted patients, 30 subjects were submitted at rest, within 5 days, to SM imaging, 4h-delayed Tl scans and echocardiography (ECHO). Left ventricle segmental uptake and wall motion were graded on a 3 points scale (0=absent to 2=normal) and compared on the basis of an 11 segments model. RESULTS AND DISCUSSION: 1) The analysis of SM normal segments demonstrated a strong concordance (97%) with Tl and ECHO, suggesting that both mitochondrial and cell membrane functions are preserved; 2) 49% of SM graded 0 segments were scored 1 by Tl and ECHO, suggesting a worse impairment of mitochondrial function with respect to cell membrane function; 3) approximately 55% of segments showing a reduced MIBI uptake were found normal using Tl, then an impaired mitochondrial but a normal cell membrane function could be hypothesized. 4) Tl provided a better estimation of the effective infarction size with respect to SM. CONCLUSIONS: The SM and Tl dual approach, allowing scintigraphic mapping of myocardial injury, seems to provide a useful tool for a complete evaluation of infarcted patients.     

Myocardial perfusion SPET in the detection of coronary artery disease in orthotopic heart transplantation

BACKGROUND: Thallium-201 (201Tl) reinjection after conventional redistribution imaging is a standard procedure, resulting in enhanced 201Tl redistribution which is compatible with viable myocardium. Although this method significantly improves identification of viable myocardium, it increases the investigation time by approximately 1 h. Thus, this technique is suboptimal from the standpoint of patient convenience, since its routine performance may be impractical in a high-volume nuclear medicine laboratory. HYPOTHESIS: This study was undertaken to evaluate the efficacy of an early 201Tl reinjection and imaging protocol in combination with sublingual nitroglycerin, to detect myocardial ischemia and/or viability, and to reduce the need for conventional (4 h) redistribution imaging. MATERIALS AND METHODS: In this study, 62 consecutive coronary patients, referred for the detection of possible myocardial ischemia and/or viability, were involved (mean age 55 years, range 41-70). Of those, 50 had previous angina attacks, with 42 having a history of previous myocardial infarction; 10 patients had coronary artery bypass grafting; and the remaining 2 had atypical chest pain. Immediately after the completion of the initial postexer-cise imaging, 0.3 mg sublingual nitroglycerin followed by the reinjection of 1 m Ci of 201Tl were administered, and two further sets of images were acquired 1 h and 4 h later. RESULTS: In each set of images, a total of 496 segments were analyzed. On postexercise imaging, 305 (61%) segments demonstrated defects of which 198 (65%) showed enhanced thallium uptake, 97 (32%) did not change, and 10 (3%) showed reverse redistribution on 1 h reinjection imaging (IRI). Of the 97 persistent defects, only 17 (6%) showed fill-in of 201Tl on 4 h redistribution imaging (CRI), while 12 (4%) segments showed reverse redistribution. On the other hand, after analyzing the 62 patients of the 1 h IRI, 17 (27%) remained unchanged while in only 1 patient (6%) of 17 the diagnosis changed from myocardial necrosis to ischemia after analysis of the 4 h CRI. CONCLUSION: These results indicate that early postexercise reinjection of 201Tl in combination with sublingual nitroglycerin followed by 1 h image acquisition may prove useful for a comprehensive and convenient assessment of myocardial ischemia and/or viability.     

Fc gamma RII on human B cells can mediate enhanced antigen presentation

As several reinjection procedures have shown encouraging results in terms of imaging, we investigated whether the kinetics of thallium-201 would differ between the standard stress-redistribution-reinjection approach and the stress-immediate reinjection approach. In 53 consecutive patients with undiagnosed chest pain, 75 MBq (2 mCi) 201Tl was injected at maximal exercise. In 26 of these patients (group I), 37 MBq (1 mCi) 201Tl was reinjected immediately after completing the exercise images (the immediate reinjection procedure) and in 27 patients (group II), 37 MBq (1 mCi) 201Tl was reinjected after completing 3-h redistribution images (the standard reinjection procedure). Mean peak 201Tl blood activity after exercise was 17.7+/-12.5 kBq/ml (4.8+/-3.4 mCi/ml) for group I versus 16.4+/-9.2 kBq/ml (4.4+/-2.5 mCi/ml) for group II (NS). The relative increase in 201Tl blood activity after reinjection of half the initial dose [37 MBq (1 mCi)] exceeded 50% of the initial peak in both groups. The relative amount of 201Tl delivered to the myocardium was assessed by the area under the curve after both exercise and reinjection, and was 117%+/-72% for group I and 112%+/-73% for group II (NS). Blood clearance of 201Tl was at least biexponential. Mean early decay constants (lambda 1) after exercise and reinjection were 0.30+/-0.18 min-1 and 0.22+/-0.046 min-1 respectively for group I (T 1/2 2.3 min and 3.2 min respectively, NS), and 0.30+/-0.12 min-1 and 0.24+/-0.07 min-1 respectively for group II (T1/2 2.3 min and 2.9 min respectively, NS). For both procedures no significant differences were found between lambda 1 after exercise and lambda 1 after injection. The mean late clearance (lambda 2) from the blood was 0.032+/-0.056 min-1 and 0.012+/-0.012 min-1 respectively for group I (T1/2 21.6 min and 57.7 min respectively, NS), and 0.036+/-0.030 min-1 and 0.014+/-0.014 min-1 respectively for group II (T1/2 19.3 min and 49.5 min respectively, NS). Also, no significant differences were found between lambda 2 after exercise for both groups and between lambda 2 after reinjection for both groups. We conclude that reinjection of 37 MBq (1 mCi) 201Tl (half the initial dose) results in a relative increase in the initial peak and a relative increase in the amount of 201Tl delivered to the myocardium of more than 50% for both the standard and the immediate reinjection procedure. The clearance of 201Tl from the blood was not influenced by exercise or by the time of reinjection. Based on 201Tl kinetics as measured in the peripheral blood, there is no reason to postpone reinjection until 3-4 h following exercise.     

Impairment of regional fatty acid uptake in relation to wall motion and thallium-201 uptake in ischaemic but viable myocardium: assessment with iodine-123-labelled beta-methyl-branched fatty acid

In coronary artery disease, discrepancy in the uptake of thallium-201 and of methyl-branched fatty acid at rest has been described. The purpose of this study was to evaluate iodine-123 labelled beta-methyl-branched fatty acid (BMIPP) myocardial uptake and wall motion at rest in segments with stress-induced ischaemia identified by stress 201Tl tomography in patients with chronic coronary artery disease. 123I-BMIPP myocardial tomography was performed at rest and was compared with the findings of exercise-reinjection 201Tl tomography in 45 patients with chronic coronary artery disease. Regional wall motion was evaluated by contrast left ventriculography in 36 patients. Among 237 segments with reversible 201Tl defects, equally decreased uptake on both reinjection 201Tl and BMIPP images was observed in 93 (39%), more severely decreased uptake of BMIPP in 118 (50%) and more severely decreased uptake of reinjection 201Tl in 26 (11%). On the other hand, among 90 segments with non-reversible 201Tl defects, each pattern was observed in 71 (79%), 6 (7%) and 13 (14%) segments, respectively. When comparing the ischaemic segments with and without more severely reduced uptake of BMIPP than of reinjection 201Tl, wall motion was impaired to a greater extent in the segments with more severely reduced uptake of BMIPP than of reinjection 201Tl [severe hypo- or dyskinesis was present in 64 (70%) of 91 segments and in 24 (22%) of 110 segments, respectively, P<0.005]. In patients with chronic coronary artery disease, resting fatty acid uptake was frequently more reduced than reinjection 201Tl in the segments with stress-induced ischaemia, while in most of the fixed perfusion defects BMIPP and reinjection 201Tl uptake decreased concordantly. In ischaemic myocardium, wall motion was impaired to a greater extent in those segments which showed more severely reduced uptake of BMIPP than of reinjection 201Tl. In ischaemic but viable myocardium, discordant BMIPP uptake less than reinjection 201Tl uptake may indicate metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities. In conclusion, the combination of resting BMIPP and stress-reinjection 201Tl imaging may provide information on metabolic alterations and wall motion abnormality at rest independent of perfusion abnormalities.