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Objective:To investigate the effect of motion correction (MC) on the calculated values of myocardial blood flow (MBF) and myocardial flow reserve (MFR) based on cadmium-zinc-telluride SPECT (CZT SPECT) images.Methods:Twenty-eight consecutive patients (10 males, 18 females, age: (60.75±11.62) years) with suspected or known coronary artery disease who underwent myocardial perfusion imaging (MPI) with dynamic CZT SPECT between June 2019 and August 2019 in TEDA International Cardiovascular Hospital were retrospectively analyzed. The MBF and MFR during rest imaging and stress imaging were quantitatively analyzed. Corridor 4DM software was used to calculate the stress MBF (sMBF) and MFR of the coronary artery branches and left ventricular (LV) before and after MC. The paired t test and Pearson correlation were used for data analysis. Results:The sMBF and MFR of LV before MC were (0.82±0.49) ml·min -1·g -1 and 1.69±0.68 respectively. After MC the two parameters increased to (1.05±0.64) ml·min -1·g -1 and 2.12±0.77 respectively ( t values: -4.87, -6.01, both P<0.001). The sMBF and MFR in left anterior descending (LAD), left circumflex (LCX), right coronary artery (RCA) and LV before MC were correlated with those after MC ( r values: 0.69-0.96, all P<0.001). If MFR <2.0 was used as the reference of impaired MFR, data before MC showed 19 patients (67.9%, 19/28) had impaired MFR, while 13 patients (46.4%, 13/28) had impaired MFR based on MFR values after MC. Conclusion:For MPI quantitative imaging with CZT SPECT, the calculated values of sMBF and MFR after MC is higher than those before MC, suggesting that MC is helpful to reduce the false positive results which may be caused by the " creep" effect of the heart.
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Objective:To investigate the diagnostic value of myocardial blood flow quantitative imaging with cadmium zinc telluride (CZT) SPECT in patients with high-risk coronary artery disease (CAD).Methods:A total of 148 patients (82 males, 66 females, age: (63.8±8.2) years) who successfully completed CZT SPECT dynamic acquisition and routine SPECT myocardial perfusion imaging (MPI) in TEDA International Cardiovascular Hospital from November 2018 to October 2020 were analyzed retrospectively. According to the results of coronary angiography (CAG), patients were divided into two groups: high-risk CAD group and low-to-medium-risk CAD group. At the case level, quantitative parameters (stress myocardial blood flow (sMBF), rest myocardial blood flow (rMBF) and myocardial flow reserve (MFR)), semi-quantitative parameters (summed stress score (SSS), summed rest score (SRS), summed difference score (SDS) and transient ischemic dilation (TID)) and left ventricular function parameters of two groups were compared. Diagnostic accuracy was evaluated by ROC curve analysis. At the vascular level, the correlation between the degree of coronary artery stenosis and some parameters was analyzed. Mann-Whitney U test, logistic regression, Spearman rank correlation analysis and DeLong test were used for statistical analysis. Results:Case level analysis showed that MFR and sMBF in high-risk CAD group were significantly lower than those in low-to-medium-risk CAD group (1.36(0.87, 1.64) vs 2.74(2.30, 3.33), 1.06(0.69, 1.48) vs 2.50(1.73, 2.95) ml·g -1·min -1; U values: 628.0 and 853.5, both P<0.001). MFR and SDS were independent predictors of high-risk CAD patients (odds ratio ( OR)=0.251(95% CI: 0.136-0.464), P<0.001; OR=1.188(95% CI: 1.026-1.375), P=0.021), and MFR was more capable of predicting high-risk CAD. MFR and sMBF had the highest accuracy in diagnosing high-risk CAD (AUCs: 0.885 and 0.844). Differences of AUCs between MFR and other parameters were statistically significant ( z values: 1.99-6.77, all P<0.05), and the best diagnostic cut-off value was ≤1.83 (sensitivity: 85.90%; specificity: 85.71%). Vascular level analysis showed that MFR and sMBF( R2 values: 0.39 and 0.35, both P<0.001) were negatively correlated with the degree of coronary stenosis, while SSS, SRS and SDS ( R2 values: 0.22, 0.12 and 0.14, all P<0.001) were positively correlated with the degree of coronary stenosis. Conclusion:Compared with conventional SPECT MPI, CZT SPECT myocardial blood flow quantitative imaging has better diagnostic efficacy and clinical value in patients with high-risk CAD.
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Objective@#To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections.@*Methods@#A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise reduction (NR), NR+ scatter correction (SC), NR+ SC+ resolution recovery (RR)), NR+ SC+ RR+ attenuation correction (AC; total corrections, TC). Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality (R2) and fraction blood volume (FBV) to assess the quality of modeling. Rest MBF (RMBF), stress MBF (SMBF) and myocardial flow reserve (MFR) quantified from no correction (NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear regression analysis were used to analyze the data.@*Results@#Compared to TC, NC showed the lowest R2 (rest: 0.69, stress: 0.78; z values: 4.78 and 4.78, both P<0.01) and highest FBV (rest: 0.37, stress: 0.40; z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR (z values: 1.27 and -3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values: from -4.55 to 1.27, all P<0.01). NR and NR+ SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+ SC, NR+ SC+ RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1.129-1.308, and Bland-Altman plots demonstrated positive biases (0.60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70, -0.11, -0.05, 0.01).@*Conclusion@#Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pinhole CZR-SPECT.
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Objective@#To investigate the incremental value of coronary flow reserve (CFR) assessed by cadmium zinc telluride(CZT)-SPECT as an adjunct to myocardial perfusion imaging (MPI) in the diagnosis of coronary artery disease (CAD).@*Methods@#Data of 132 patients (89 males, 43 females; 40-81 years) with or suspected with CAD who successfully underwent rest and stress MPI and CFR from November 2017 to October 2018 in Zhongshan Hospital Affiliated to Fudan University were retrospectively analyzed. Based on coronary angiography (CAG) as the " gold standard" , the value of MPI and MPI+ CFR in the diagnosis of CAD was evaluated and compared. χ2 test or Fisher exact probability test was used for data analysis.@*Results@#Of 132 patients, 61 (46.2%) were CAD with stenosis of at least 75% in one vessel (47.5%, 29/61), two vessels (34.4%, 21/61), or three vessels (18.0%, 11/61). A total of 104 (26.3%) vessels with stenosis of at least 75%, 25 (6.3%) vessels with stenosis of 65%-74%, and 30 (7.6%) vessels with stenosis of 50%-64% were found in 396 vessels. For detecting coronary stenosis of at least 75%, the sensitivity and accuracy of MPI on per-patient analysis were 86.89%(53/61) and 68.94%(91/132), which increased to 96.72%(59/61; χ2=3.921, P<0.05) and 87.88%(116/132; χ2=13.984, P<0.01) by MPI+ CFR. On per-vessel analysis, the sensitivity and accuracy of MPI were 72.12%(75/104) and 77.53%(307/396) and increased to 96.15%(100/104; χ2=22.511, P<0.01) and 85.10%(337/396; χ2=7.479, P<0.05) by MPI+ CFR. The sensitivity of MPI for predicting one, two, and three vessels disease were 72.41%(21/29), 42.86%(9/21), and 5/11 and were improved to 93.10%(27/29; χ2=4.350, P=0.037), 90.48%(19/21; χ2=10.714, P=0.001), and 11/11 (P=0.012) by MPI+ CFR. For coronary with stenosis of 65%-74%, the sensitivity of MPI was 24.00%(6/25) and was improved to 64.00%(16/25; χ2=8.117, P=0.004) by MPI+ CFR. For coronary with stenosis of 50%-64%, the sensitivity of MPI was 40.00%(12/30) and was improved to 76.67%(23/30; χ2=8.297, P=0.004) by MPI+ CFR.@*Conclusion@#As an adjunct to MPI, CFR can significantly improve the sensitivity and accuracy in the diagnosis of CAD, particularly for patients with mild stenosis and multivessel CAD.
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Objective@#To explore the optimal and rapid imaging acquisition time and clinical applicability when using high- and low-dose one day rest/stress myocardial perfusion imaging (MPI) with cadmium-zinc-telluride heart dedicated SPECT (CZT-SPECT).@*Methods@#The MPI data with high-dose rest/stress protocol in 51 patients (22 males, 29 females, age: (55.4±8.5) years) between November 2017 and December 2017 and those with low-dose protocol in 50 patients (27 males, 23 females, age: (59.1±12.8) years) between July 2018 and October 2018 were retrospectively analyzed. The MPI was performed with CZT-SPECT. Each patient received 296-370 MBq rest dose of 99Tcm-methoxyisobutylisonitrile (MIBI) for high-dose protocol, 111-222 MBq rest dose of 99Tcm-MIBI for low-dose protocol. Stress dose was 3 times of the corresponding rest dose. Rest and stress scans were acquired 6 min and 4 min for high-dose protocol, while 8 min and 6 min for low-dose protocol in total. All rest or stress imaging data were reconstructed from list-mode raw data to obtain scan durations of 1 min, 2 min, etc, up to the maximum of acquisition time. Image quality at different acquisition times were evaluated, and myocardial perfusion and function parameters were compared. Paired t test, Wilcoxon signed rank test, Pearson correlation and Bland-Altman analyses were used for data analysis.@*Results@#The image quality was rated as excellent/good in all patients (100%, 51/51) when acquisition time ≥3 min and ≥2 min respectively for rest and stress imaging with high-dose protocol, the similar results was obtained (100%, 50/50) when acquisition time ≥4 min and ≥3 min respectively for rest and stress imaging with low-dose protocol. The quantitative perfusion parameters(summed rest scores, summed stress scores, total perfusion deficit) and left ventricle ejection fraction (LVEF) at shorter acquisition times (3 min/2 min, 4 min/3 min) were not significantly different from the results at the longer acquisition times (6 min/4 min, 8 min/6 min; t values: from -1.196 to 1.597, z values: from -1.963 to 1.945, all P>0.05). Those parameters at shorter and longer acquisition times showed strong correlations (all r>0.700, all P<0.001), and Bland-Altman analysis revealed good agreement between them.@*Conclusion@#The optimal acquisition time is 3 min/2 min for high-dose one-day rest/stress CZT-SPECT MPI, and 4 min/3 min for low-dose protocol, which can significantly shorten the MPI acquisition time, then reliable perfusion parameters and LVEF can be obtained under the premise of ensuring image quality, making it the better clinical applicability.
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Objective To explore the optimal and rapid imaging acquisition time and clinical ap-plicability when using high-and low-dose one day rest/stress myocardial perfusion imaging ( MPI) with cad-mium-zinc-telluride heart dedicated SPECT ( CZT-SPECT) . Methods The MPI data with high-dose rest/stress protocol in 51 patients (22 males, 29 females, age:(55.4±8.5) years) between November 2017 and December 2017 and those with low-dose protocol in 50 patients (27 males, 23 females, age:(59.1±12.8) years) between July 2018 and October 2018 were retrospectively analyzed. The MPI was performed with CZT-SPECT. Each patient received 296-370 MBq rest dose of 99Tcm-methoxyisobutylisonitrile (MIBI) for high-dose protocol, 111-222 MBq rest dose of 99 Tcm-MIBI for low-dose protocol. Stress dose was 3 times of the corresponding rest dose. Rest and stress scans were acquired 6 min and 4 min for high-dose protocol, while 8 min and 6 min for low-dose protocol in total. All rest or stress imaging data were reconstructed from list-mode raw data to obtain scan durations of 1 min, 2 min, etc, up to the maximum of acquisition time. Image quality at different acquisition times were evaluated, and myocardial perfusion and function parame-ters were compared. Paired t test, Wilcoxon signed rank test, Pearson correlation and Bland-Altman analyses were used for data analysis. Results The image quality was rated as excellent/good in all patients ( 100％, 51/51) when acquisition time≥3 min and ≥2 min respectively for rest and stress imaging with high-dose protocol, the similar results was obtained ( 100％, 50/50) when acquisition time≥4 min and≥3 min re-spectively for rest and stress imaging with low-dose protocol. The quantitative perfusion parameters(summed rest scores, summed stress scores, total perfusion deficit) and left ventricle ejection fraction ( LVEF) at shor-ter acquisition times (3 min/2 min, 4 min/3 min) were not significantly different from the results at the lon-ger acquisition times (6 min/4 min, 8 min/6 min;t values:from -1.196 to 1.597, z values:from -1.963 to 1. 945, all P>0. 05) . Those parameters at shorter and longer acquisition times showed strong correlations ( all r>0.700, all P<0.001) , and Bland-Altman analysis revealed good agreement between them. Conclusion The opti-mal acquisition time is 3 min/2 min for high-dose one-day rest/stress CZT-SPECT MPI, and 4 min/3 min for low-dose protocol, which can significantly shorten the MPI acquisition time, then reliable perfusion parameters and LVEF can be obtained under the premise of ensuring image quality, making it the better clinical applicability.
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Objective To investigate the impact on myocardial blood flow (MBF) quantitation with multi-pinhole cadmium zinc telluride (CZT)-SPECT with or without partial physical corrections. Methods A total of 30 patients (18 males, 12 females; age: (63±9) years) with suspected or known coronary heart diseases who underwent dynamic SPECT from July 2018 to January 2019 in Fuwai Hospital were enrolled. Images were reconstructed using different corrections: no correction (NC), partial corrections ((noise re-duction ( NR) , NR+scatter correction ( SC) , NR+SC+resolution recovery ( RR) ) , NR+SC+RR+attenua-tion correction ( AC;total corrections, TC) . Kinetic modeling integrated one-tissue two-compartment model while using index of fitting quality ( R2 ) and fraction blood volume ( FBV) to assess the quality of modeling. Rest MBF ( RMBF) , stress MBF ( SMBF) and myocardial flow reserve ( MFR) quantified from no correc-tion ( NC) or partial corrections were compared with those of TC. Wilcoxon signed rank test and linear re-gression analysis were used to analyze the data. Results Compared to TC, NC showed the lowest R2( rest:0.69, stress:0.78;z values:4.78 and 4.78, both P<0.01) and highest FBV ( rest:0.37, stress:0.40;z values: -3.40 and -3.30, both P<0.01). The improvement of R2 and FBV was consistent with increased corrective terms. Compared with TC, NC overestimated SMBF and MFR ( z values:1.27 and-3.50, both P<0.01), all partial corrections overestimated RMBF and SBMF (z values:from -4.55 to 1.27, all P<0.01). NR and NR+SC underestimated MFR (both P<0.05). Linear regression analysis showed that the regressive coefficients of RMBF between NC, NR, NR+SC, NR+SC+RR and TC were 0.908-1.210, and Bland-Altman plots of RMBF demonstrated positive or negative biases (-0.07, 0.21, 0.26, 0.15 ml·min-1·g-1). The regression coefficients of SMBF were 1. 129-1. 308, and Bland-Altman plots demonstrated positive biases (0. 60, 0.25, 0.28, 0.24 ml·min-1·g-1). The regression coefficients of MFR were 0.907-1.318, and Bland-Altman plots demonstrated positive or negative biases (0.70,-0.11,-0.05, 0.01). Conclusion Full physical corrections can improve the index of fitting quality in the kinetic modeling and reduce left ventricle spillover, which help to warrant the accuracy of SPECT myocardial blood flow quantitation with multi-pin-hole CZR-SPECT.
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Objective To investigate the incremental value of coronary flow reserve ( CFR) as-sessed by cadmium zinc telluride(CZT)-SPECT as an adjunct to myocardial perfusion imaging (MPI) in the diagnosis of coronary artery disease (CAD). Methods Data of 132 patients (89 males, 43 females; 40-81 years) with or suspected with CAD who successfully underwent rest and stress MPI and CFR from November 2017 to October 2018 in Zhongshan Hospital Affiliated to Fudan University were retrospectively analyzed. Based on coronary angiography (CAG) as the " gold standard" , the value of MPI and MPI+CFR in the di-agnosis of CAD was evaluated and compared. χ2 test or Fisher exact probability test was used for data analy-sis. Results Of 132 patients, 61 (46.2％) were CAD with stenosis of at least 75％ in one vessel (47.5％, 29/ 61), two vessels (34.4％, 21/ 61), or three vessels (18.0％, 11/ 61). A total of 104 (26.3％) vessels with stenosis of at least 75％, 25 (6.3％) vessels with stenosis of 65％-74％, and 30 (7.6％) vessels with stenosis of 50％-64％ were found in 396 vessels. For detecting coronary stenosis of at least 75％, the sensi-tivity and accuracy of MPI on per-patient analysis were 86.89％(53/ 61) and 68.94％(91/ 132), which in-creased to 96.72％(59/ 61; χ2 = 3.921, P<0.05) and 87.88％(116/ 132; χ2 = 13.984, P<0.01) by MPI+CFR. On per-vessel analysis, the sensitivity and accuracy of MPI were 72.12％ (75/ 104) and 77. 53％(307/ 396) and increased to 96.15％(100/ 104; χ2 = 22. 511, P<0.01) and 85.10％(337/ 396; χ2 = 7.479, P<0.05) by MPI+CFR. The sensitivity of MPI for predicting one, two, and three vessels disease were 72. 41％(21/ 29), 42.86％ (9/ 21), and 5/ 11 and were improved to 93.10％ (27/ 29; χ2 = 4.350, P =0. 037), 90.48％(19/ 21; χ2 = 10.714, P = 0.001), and 11/ 11 (P = 0.012) by MPI+CFR. For coronary with stenosis of 65％-74％, the sensitivity of MPI was 24. 00％(6/ 25) and was improved to 64.00％(16/25; χ2 = 8.117, P= 0.004) by MPI+CFR. For coronary with stenosis of 50％-64％, the sensitivity of MPI was 40.00％(12/ 30) and was improved to 76.67％(23/ 30; χ2 = 8.297, P= 0.004) by MPI+CFR. Conclu-sion As an adjunct to MPI, CFR can significantly improve the sensitivity and accuracy in the diagnosis of CAD, particularly for patients with mild stenosis and multivessel CAD.
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The dedicated cardiac cadmium-zinc-telluride (CZT) SPECT device has been commercially applied to the clinics in recent years. Compared to the traditional SPECT, cardiac CZT SPECT has better image quality, higher spatial and energy resolution with shorter acquisition duration and lower radiation exposure. With these advantages, the clinical application of cardiac CZT SPECT is of great potential. This review summarizes the technological advances, clinical progress and current shortages of cardiac CZT SPECT.
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A cintilografia miocárdica de perfusão (CMP) é um dos métodos mais utilizados na avaliação de pacientes com suspeita de coronariopatia por seu valor diagnóstico e prognóstico. Duas de suas maiores limitações são o uso de radiação e a duração prolongada dosexames. Entretanto, novas Gamacâmaras de CZT (GC-CZT) têm permitido reduzir as doses dos radiotraçadores empregadas e o tempo de aquisição. O valor prognóstico desses novos protocolos não é conhecido.Objetivo: Determinar o valor prognóstico de um novo protocolo de CMP ultrarrápido e de baixa radiação numa GC-CZT. População: Pacientes com suspeita de coronariopatia consecutivamente submetidos a CMP numa GC-CZT no período de novembro de 2011 a junho de 2012.Metodologia: Foi utilizado protocolo de mesmo dia, iniciado pela fase de repouso com dose de 5 mCi e posterior estresse com dose de 15 mCi de Tc-99m sestamibi. Os tempos de aquisição foram de 6 e 3 minutos, respectivamente. Os exames foram classificados como normais ou anormais e escores de perfusão (SSS, SRS e SDS) foram calculados. Pacientes foram acompanhados mediante contato telefônico semestral. Os eventos avaliados foram morte, infarto não fatal e revascularização tardia (> 60 dias após CMP). Foi utilizado método de Coxpara identificar os preditores.Resultados: Setecentos e noventa e dois pacientes foram acompanhados por 21,3 ± 3,7 meses. A idade média foi de 65,2 ± 12,7 anos, sendo 50,3% do sexo masculino e o IMC médio de 26,9 ± 4,7. Hipertensão arterial foi o fator de risco mais frequente (59,5%), seguidode dislipidemia (51,9%) e diabetes (23,3%). Estresse físico foi empregado em 438 (55,3%) pacientes; 618 (78%) CMP foram normais. A dosimetria média dos exames foi 6 mSv e a duração média, de 48 ± 11 minutos. Durante o seguimentos ocorreram 12 óbitos, 4 infartos não fatais...
Myocardial perfusion scintigraphy (MPS) is one of the most used imaging methods for the evaluation of patients for coronary artery disease (CAD) due to its diagnostic and prognostic value. Two of its main limitations are radiation use and scan duration. However, CZT cameras (CZT-C) have allowed tracer dose and scan time reductions. However, the prognostic value of these new protocols is not known. Objective: To determine the prognostic value of a new, ultrafast, low dose protocol in a CZT-C. Population: Patients with suspect CAD undergoing MPS from 11/2011 to 6/2012 were studied. Methods: They had a 1-day Tc-99m sestamibi protocol starting with rest study (5 mCi dose) followed by stress (15 mCi). Acquisition times were 6 and 3 minutes respectively. MPS studied were classified as normal or abnormal and perfusion scores (SSS, SRS and SDS) were calculated. Patients were accompanied by 6-month phone calls. Events were defined as death, nonfatal myocardial infarction and late revascularization (> 60 days after MPS) and analyzed with the Cox method.Results: 792 patients were followed for 21.3 ± 3.7 months. Age was 65.2 ± 12.7 years, 50.3% were male and body mass index was 26.9 ± 4.7. Hypertension was the most frequent risk factor (59.5%), followed by hypercholesterolemia (51.9%) and diabetes (23.3%). Exercise was used in 438 (55.3%); 618 (78%) MPS studies were normal. Mean dosimetry was 6 mSv and mean scan time, 48 ± 11 minutes. During follow-up, there were 12 deaths...
Subject(s)
Humans , Male , Female , Aged , Carotid Artery Diseases , Gamma Cameras , Myocardial Perfusion Imaging/methods , Prognosis , Radiation Exposure Control , Semiconductors/trends , Cadmium/therapeutic use , Radiopharmaceuticals/administration & dosage , Risk Factors , Data Interpretation, Statistical , Tellurium , Treatment Outcome , Tellurium/therapeutic use , Zinc/therapeutic useABSTRACT
A method has been developed for the determination of tellurium(Te) in soil by hydride generation(HG) atomic fluorescence spectrometry(AFS) based on dielectric barrier discharge(DBD) plasma as low-temperature atomizer. The samples were dissolved by aqua regior acid without matrix separation. The characteristics of the DBD atomizer and the effects of different experimental parameters, such as discharge power, flow rates of discharge gas and AFS carrier gas, lamp current, negative high voltage, observation height, KBH4 concentration and acid medium on the determination were studied and the analytical performances of the present method were evaluated. The detection limit of Te was 0.08 μg/L. The linear range was from 0.5 to 80 μg/L. Recoveries of spiked sample was from 90% to 103 %. The accuracy of this method was verified by the determination of Te in the reference materials. The results agreed well with the reference values.
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Tellurium is a rare element which has been regarded as a toxic, non-essential trace element and its biological role is not clearly established to date. Besides of that, the biological effects of elemental tellurium and some of its inorganic and organic derivatives have been studied, leading to a set of interesting and promising applications. As an example, it can be highlighted the uses of alkali-metal tellurites and tellurates in microbiology, the antioxidant effects of organotellurides and diorganoditellurides and the immunomodulatory effects of the non-toxic inorganic tellurane, named AS-101, and the plethora of its uses. Inasmuch, the nascent applications of organic telluranes (organotelluranes) as protease inhibitors and its applications in disease models are the most recent contribution to the scenario of the biological effects and applications of tellurium and its compounds discussed in this manuscript.
O telúrio é um elemento não-essencial raro que vem sendo considerado tóxico, e o seu papel biológico é ainda pouco esclarecido. Apesar disso, os efeitos biológicos do telúrio elementar e de alguns derivados inorgânicos e orgânicos que têm sido estudados revelam um conjunto de aplicações diversificadas interessantes e promissoras. Como exemplo, pode-se destacar os usos de teluritos e teluratos de metais alcalinos em microbiologia, o efeito antioxidante de teluretos e diteluretos orgânicos, os efeitos imunomodulatórios e a diversidade de usos correlacionados a este efeito de uma telurana inorgânica denominada AS-101. Ademais, as aplicações de teluranas orgânicas (organoteluranas) como inibidoras de proteases e as aplicações em modelos de doenças compõem a mais recente contribuição ao cenário dos efeitos e aplicações biológicas do telúrio e seus compostos discutidas neste manuscrito.
Subject(s)
Humans , Tellurium/pharmacology , Structure-Activity Relationship , Tellurium/chemistry , Tellurium/classificationABSTRACT
Objective To establish a method for determination of tellurium(Ti)in the air of workplace by microwave digestion-HG-AFS. Methods The air samples were collected by micropore filters and the concentration of tellurium was determined by microwave digestion-HG-AFS. Results In this method, the linear range was 0.11-40.0 ?g/L, the detection limit was 0.11 ?g/L, the lowest detected concentration of tellurium was 0.000 09 mg/m3(based on 30 L air sample), the rate of recovery was in the range of 95.5%-98.2%, the RSD was less than 3%. Conclusion The method is rapid, accurate, sensitive and suitable for the determination of tellurium in the air of workplace.