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1.
Fetal Diagn Ther ; 51(5): 516-524, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38838656

RESUMO

INTRODUCTION: The aim of this study was to assess the short- and long-term outcome of selective reduction by fetoscopy-guided bipolar cord coagulation in monochronic twin pregnancies. METHODS: Retrospective analysis was conducted of a consecutive cohort of all monochorionic twin pregnancies treated with fetoscopy-guided bipolar cord coagulation between December 2015 and December 2022 in a single center in China. RESULTS: A total of 43 monochronic twin pregnancies undergoing fetoscopy-guided bipolar cord coagulation were analyzed. There were 5 intrauterine deaths with an 88.4% (38/43) survival rate overall. The preterm premature rupture of the membranes rate was 13.2%, and the preterm birth before 37 and 32 weeks was 42.1% and 13.1%, respectively. An uptrend in the survival rate (78.9 vs. 95.8%, p = 0.086) and a downtrend of procedure time (30 vs. 16.5 min, p = 0.036) were observed over time (period 1 from December 2015 to December 2019 verses period 2 from January 2020 to December 2022). Long-term outcome was assessed in 94.6% (35/37) of survivors, and 91.4% (32/35) had normal neurodevelopmental outcome. CONCLUSION: Fetoscopy-guided bipolar cord coagulation for fetal reduction in complicated monochorionic twin pregnancies could achieve a favorable short- and long-term outcome, especially in experienced hands.


Assuntos
Fetoscopia , Redução de Gravidez Multifetal , Gravidez de Gêmeos , Humanos , Feminino , Gravidez , Fetoscopia/métodos , Estudos Retrospectivos , Redução de Gravidez Multifetal/métodos , Adulto , Resultado do Tratamento , Gêmeos Monozigóticos , Resultado da Gravidez
2.
Biochem Biophys Res Commun ; 602: 27-34, 2022 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-35247701

RESUMO

Bilirubin oxidation end products (BOXes) are associated with the late-developing neurological deficits after subarachnoid hemorrhage (SAH) possibly by direct constricting the cerebral arteries, but their specific impacts on neurons especially in the state of hypoxia, a prominent feature during the late stage of SAH, remain unclear. Here, we explored the effects of BOXes on the primary cortical neurons subjected to CoCl2-induced hypoxia by evaluating the morphological and apoptotic changes of neurons. The present study showed that Z-BOX B but not Z-BOX A greatly alleviated CoCl2-induced neuronal cell deterioration and apoptosis. Immunocytochemical staining assay showed Z-BOX B significantly increased neurite length, the numbers of both secondary and tertiary branches, and the protein level of Synaptophysin. Caspase 3/7 apoptosis assay and DAPI staining showed that Z-BOX B markedly reduced primary cortical neurons apoptosis. The expression of cleaved Caspase-3 was suppressed by Z-BOX B treatment, while the expression of Bcl-xL was upregulated. To further discover the mechanism of the neuroprotective effect observed in Z-BOX B, we found Z-BOX B increased the expression of p-mTOR, p-Akt, and p-p70S6K. In general, our results implicated Z-BOX B may prevent CoCl2-induced primary cortical neurons apoptosis by activating sAkt/mTOR/p70S6K signaling pathway. Hence, the present data may provide new insights into the pathophysiological mechanism of delayed neurological dysfunction after SAH and novel targets for treating SAH.


Assuntos
Fármacos Neuroprotetores , Hemorragia Subaracnóidea , Apoptose , Bilirrubina/metabolismo , Bilirrubina/farmacologia , Sobrevivência Celular , Cobalto , Humanos , Hipóxia/metabolismo , Neurônios/metabolismo , Fármacos Neuroprotetores/metabolismo , Fármacos Neuroprotetores/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais , Hemorragia Subaracnóidea/complicações , Serina-Treonina Quinases TOR/metabolismo
3.
Anticancer Drugs ; 32(2): 127-137, 2021 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-33417325

RESUMO

Gastric cancer is one of the most common malignant tumors. MicroRNA-196b (miR-196b) has been demonstrated to play important roles in human cancers. However, its functions in gastric cancer progression were still largely unknown. In this study, the expression of miR-196b was determined by quantitative real-time PCR. Esophageal cancer-related gene 4 (ECRG4) level was examined by western blot assay and immunohistochemistry staining assay. Cell proliferation was evaluated by Cell Counting Kit-8 (CCK-8) assay and colony formation assay. Cell migration and invasion were analyzed by transwell assay. The association between miR-196b and ECRG4 was analyzed by dual-luciferase reporter assay. The functional role of miR-196b in vivo was analyzed by murine xenograft assay. As a result, we found the expression of miR-196b was elevated and the protein expression of ECRG4 was reduced in gastric cancer tissues and cells. MiR-196b inhibition suppressed gastric cancer cell proliferation, migration and invasion. ECRG4 was a target of miR-196b and its protein expression was negatively regulated by miR-196b. Moreover, ECRG4 overexpression showed similar effects with miR-196b inhibition on the malignant behaviors of GC cells and ECRG4 knockdown reversed the effects of miR-196b inhibition on gastric cancer cell proliferation, migration and invasion. In addition, miR-196b inhibition suppressed tumor volume and weight in vivo. In conclusion, downregulation of miR-196b inhibited gastric cancer progression by modulating ECRG4 expression, indicating that miR-196b might be a potential therapeutic target for gastric cancer.


Assuntos
MicroRNAs/biossíntese , Neoplasias Gástricas/genética , Neoplasias Gástricas/patologia , Proteínas Supressoras de Tumor/biossíntese , Idoso , Animais , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Regulação para Baixo , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Camundongos , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase em Tempo Real , Regulação para Cima
4.
Pharmacol Res ; 174: 105923, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34607006

RESUMO

Idiopathic pulmonary fibrosis (IPF) induces significant morbidity and mortality, for which there are limited therapeutic options available. Here, we found that tetraethylthiuram disulphide (disulfiram, DSF), a derivative of thiuram, used in the treatment of alcohol abuse, has an inhibitory effect on bleomycin (BLM)-induced pulmonary fibrosis via the attenuation of the fibroblast-to-myofibroblast transition, migration, and proliferation of fibroblasts. Furthermore, DSF inhibited the activation of primary pulmonary fibroblasts and fibroblast cell line under transforming growth factor-ß 1 (TGF-ß1) challenge. Mechanistically, the anti-fibrotic effect of DSF on fibroblasts depends on the inhibition of TGF-ß signalling. We further determined that DSF interrupts the interaction between SMAD3 and TGF-ß receptor Ι (TBR Ι), and identified that DSF directly binds with SMAD3, in which Trp326, Thr330, and Cys332 of SMAD3 are critical binding sites for DSF. Collectively, our results reveal a powerful anti-fibrotic function of DSF in pulmonary fibrosis through the inhibition of TGF-ß/SMAD signalling in pulmonary fibroblasts, indicating that DSF is a promising therapeutic candidate for IPF.


Assuntos
Dissuasores de Álcool/uso terapêutico , Dissulfiram/uso terapêutico , Fibrose Pulmonar/tratamento farmacológico , Actinas/metabolismo , Dissuasores de Álcool/farmacologia , Animais , Bleomicina , Cadeia alfa 1 do Colágeno Tipo I/genética , Cadeia alfa 1 do Colágeno Tipo I/metabolismo , Dissulfiram/farmacologia , Fibronectinas/genética , Fibronectinas/metabolismo , Células HEK293 , Humanos , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Células NIH 3T3 , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/genética , Fibrose Pulmonar/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta/genética , Fator de Crescimento Transformador beta/metabolismo
5.
Pharmacol Res ; 158: 104884, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32428667

RESUMO

Idiopathic pulmonary fibrosis (IPF) is a chronic and irreversible lung disease with limited therapeutic strategies. Lycorine (LYC), an alkaloid isolated from Amaryllidaceae family plants, exhibits effective anti-inflammatory, antiviral, and anti-tumor activities. In this study, we attempted to determine the effect of LYC on bleomycin (BLM)-induced IPF and NLRP3 inflammasome activation. Our results demonstrated that the LYC treatment ameliorated BLM-induced pulmonary fibrosis and inflammation in mice. LYC inhibited active Caspase-1 expression and lactate dehydrogenase (LDH) release during BLM-induced acute lung injury (ALI) in mice. Furthermore, our in vitro assay showed that LYC inhibited LPS/Nigericin- or LPS/ATP-induced NACHT, LRP and PYD domains-containing protein 3 (NLRP3) inflammasome activation, and pyroptosis in bone marrow-derived macrophages (BMDMs). Mechanically, LYC could disturb the interaction of NLRP3 with apoptosis-associated speck-like protein containing a CARD (ASC) by targeting the pyrin domain (PYD) on Leu9, Leu50, and Thr53. Our findings indicate that LYC ameliorated BLM-induced pulmonary fibrosis by inhibiting NLRP3 inflammasome activation and pyroptosis through targeting the PYD domain of ASC. Thus, LYC might be a potential therapeutic agent for pulmonary inflammation and fibrosis.


Assuntos
Alcaloides de Amaryllidaceae/uso terapêutico , Bleomicina/toxicidade , Proteína 3 que Contém Domínio de Pirina da Família NLR/antagonistas & inibidores , Fenantridinas/uso terapêutico , Fibrose Pulmonar/induzido quimicamente , Fibrose Pulmonar/tratamento farmacológico , Piroptose/efeitos dos fármacos , Alcaloides de Amaryllidaceae/química , Alcaloides de Amaryllidaceae/farmacologia , Animais , Antibióticos Antineoplásicos/toxicidade , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Células Cultivadas , Relação Dose-Resposta a Droga , Células HEK293 , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular/métodos , Proteína 3 que Contém Domínio de Pirina da Família NLR/metabolismo , Fenantridinas/química , Fenantridinas/farmacologia , Estrutura Secundária de Proteína , Fibrose Pulmonar/metabolismo , Piroptose/fisiologia
6.
Front Endocrinol (Lausanne) ; 15: 1345573, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38919479

RESUMO

Introduction: Preeclampsia is a disease with an unknown pathogenesis and is one of the leading causes of maternal and perinatal morbidity. At present, early identification of high-risk groups for preeclampsia and timely intervention with aspirin is an effective preventive method against preeclampsia. This study aims to develop a robust and effective preeclampsia prediction model with good performance by machine learning algorithms based on maternal characteristics, biophysical and biochemical markers at 11-13 + 6 weeks' gestation, providing an effective tool for early screening and prediction of preeclampsia. Methods: This study included 5116 singleton pregnant women who underwent PE screening and fetal aneuploidy from a prospective cohort longitudinal study in China. Maternal characteristics (such as maternal age, height, pre-pregnancy weight), past medical history, mean arterial pressure, uterine artery pulsatility index, pregnancy-associated plasma protein A, and placental growth factor were collected as the covariates for the preeclampsia prediction model. Five classification algorithms including Logistic Regression, Extra Trees Classifier, Voting Classifier, Gaussian Process Classifier and Stacking Classifier were applied for the prediction model development. Five-fold cross-validation with an 8:2 train-test split was applied for model validation. Results: We ultimately included 49 cases of preterm preeclampsia and 161 cases of term preeclampsia from the 4644 pregnant women data in the final analysis. Compared with other prediction algorithms, the AUC and detection rate at 10% FPR of the Voting Classifier algorithm showed better performance in the prediction of preterm preeclampsia (AUC=0.884, DR at 10%FPR=0.625) under all covariates included. However, its performance was similar to that of other model algorithms in all PE and term PE prediction. In the prediction of all preeclampsia, the contribution of PLGF was higher than PAPP-A (11.9% VS 8.7%), while the situation was opposite in the prediction of preterm preeclampsia (7.2% VS 16.5%). The performance for preeclampsia or preterm preeclampsia using machine learning algorithms was similar to that achieved by the fetal medicine foundation competing risk model under the same predictive factors (AUCs of 0.797 and 0.856 for PE and preterm PE, respectively). Conclusions: Our models provide an accessible tool for large-scale population screening and prediction of preeclampsia, which helps reduce the disease burden and improve maternal and fetal outcomes.


Assuntos
Aprendizado de Máquina , Pré-Eclâmpsia , Humanos , Feminino , Gravidez , Pré-Eclâmpsia/diagnóstico , Adulto , China/epidemiologia , Estudos Prospectivos , Estudos de Coortes , Estudos Longitudinais , Biomarcadores/sangue , Algoritmos , Fatores de Risco , Prognóstico , Fator de Crescimento Placentário/sangue
7.
Sci Total Environ ; 859(Pt 1): 160143, 2023 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-36375544

RESUMO

BACKGROUND: Little is known about the non-linear cumulative effects of temperature on blood pressure (BP) during pregnancy. We investigated the differing effects of daily ambient temperature on BP for up to 30 days in three trimesters. METHODS: The first, second, and third trimester analyses included 2547, 2299, and 2011 pregnant women, respectively, from a prospective cohort in Nanjing from January 2017 to January 2020. BP was measured at each follow-up visit. The individual daily temperature exposures were calculated for 30 days prior to the follow-up date. The Distributed Lag Non-linear Model was used to investigate the relationship between temperature and BP in each trimester. RESULTS: Temperatures under 15 °C elevate systolic, diastolic BP, and mean arterial pressure (SBP, DBP, and MAP) in the first trimester, while temperatures above 15 °C reduce SBP in the second and third trimesters. By using Distributed Lag Linear Models, we estimated that with a 1 °C decrease in daily temperature, the SBP and DBP increased by 0.32 (95 % CI: 0.12, 0.52) and 0.23 (95 % CI: 0.07, 0.39) mmHg, respectively, in the first trimester with a 20-day cumulative lag, while with a 1 °C increase in daily temperature, the SBP decreased by 0.23 (0.35, 0.10) mmHg in the third trimester with a 30-day cumulative lag. The significant effects of temperature mainly manifested between 2 and 4 weeks of exposure. CONCLUSIONS: Temperature has different effects on BP over three trimesters. Protective measures to reduce cold-related BP rise will help reduce the risk of hypertensive disorders of pregnancy.


Assuntos
Hipertensão , Feminino , Gravidez , Humanos , Pressão Sanguínea/fisiologia , Estudos de Coortes , Estudos Prospectivos , Trimestres da Gravidez/fisiologia
8.
Front Pharmacol ; 13: 835979, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35355726

RESUMO

Pulmonary fibrosis is a group of life-threatening diseases with limited therapeutic options. The involvement of cannabinoid type 1 receptors (CB1R) has been indicated in fibrotic diseases, but whether or not the activation of CB1R can be a benefit for fibrosis treatment is controversial. In this study, we investigated the effects of arachidonoylcyclopropylamide (ACPA), as a selective CB1R agonist, on bleomycin (BLM)-induced pulmonary fibrosis. We showed that ACPA treatment significantly improved the survival rate of BLM-treated mice, alleviated BLM-induced pulmonary fibrosis, and inhibited the expressions of extracellular matrix (ECM) markers, such as collagen, fibronectin, and α-SMA. The enhanced expressions of ECM markers in transforming growth factor-beta (TGF-ß)-challenged primary lung fibroblasts isolated from mouse lung tissues were inhibited by ACPA treatment in a dose-dependent manner, and the fibroblast migration triggered by TGF-ß was dose-dependently diminished after ACPA administration. Moreover, the increased mRNA levels of CB1R were observed in both lung fibroblasts of BLM-induced fibrotic mice in vivo and TGF-ß-challenged primary lung fibroblasts in vitro. CB1R-specific agonist ACPA significantly diminished the activation of TGF-ß-Smad2/3 signaling, i.e., the levels of p-Smad2 and p-Smad3, and decreased the expressions of downstream effector proteins including slug and snail, which regulate ECM production, in TGF-ß-challenged primary lung fibroblasts. Collectively, these findings demonstrated that CB1R-specific agonist ACPA exhibited antifibrotic efficacy in both in vitro and in vivo models of pulmonary fibrosis, revealing a novel anti-fibrosis approach to fibroblast-selective inhibition of TGF-ß-Smad2/3 signaling by targeting CB1R.

9.
Int J Gynaecol Obstet ; 156(1): 28-33, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33459352

RESUMO

OBJECTIVE: To construct an ultrasound partogram using serial transperineal sonographic measurements of the angle of fetal head progression during the first stage of labor, and to compare it with a conventional partogram based on digital vaginal examinations. METHODS: Between 2017 and 2018, a prospective cohort study at Drum Tower Hospital, Nanjing, China, recruited 375 nulliparous women with singleton pregnancy and spontaneous onset of labor at 37 or more gestational weeks. Transperineal ultrasound scans were performed to measure the angle of progression (AoP) every 0.5-1 h until the second stage. Vaginal examinations were also used to measure cervical dilatation. Repeated-measures analysis was used to generate labor curves. RESULTS: The labor curve generated by AoP had a pattern similar to that based on cervical dilatation. There was an initial slow period lasting approximately 5.5 h until the cervical dilatation or AoP reached the inflection point (4 cm and 119°, respectively), followed by a second, more rapid period, lasting approximately 2.5 h. CONCLUSION: Based on ultrasound data, it was feasible to construct an "angle of progression partogram" of the first stage of labor, which was similar in pattern to the partogram based on cervical dilatation measured in the same cohort.


Assuntos
Primeira Fase do Trabalho de Parto , Ultrassonografia Pré-Natal , Feminino , Cabeça/diagnóstico por imagem , Humanos , Apresentação no Trabalho de Parto , Gravidez , Estudos Prospectivos , Ultrassonografia
10.
Front Cardiovasc Med ; 8: 764587, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35155595

RESUMO

OBJECTIVE: To evaluate the feasibility of 9. 4-T postmortem MRI (pm-MRI) for assessment of major congenital heart defects (CHD) cases terminated in the early stage of gestation. METHODS: Fetuses with CHD detected by the detailed first-trimester ultrasound scan and terminated before 18 gestational weeks were recruited between January 2018 and June 2020. All fetuses were offered 9.4-T pm-MRI examinations and those terminated over 13+6 weeks were offered conventional autopsies simultaneously. Findings of pm-MRI were compared with those of conventional autopsy and prenatal ultrasound. RESULTS: A total of 19 fetuses with major CHD were analyzed, including 6 cases of the atrioventricular septal defect, 5 cases of Tetralogy of Fallot, 3 cases of hypoplastic left heart syndrome, 1 case of tricuspid atresia, 1 case of transposition of the great arteries, 1 case of severe tricuspid regurgitation, and 2 cases of complex CHD. Pm-MRI had concordant findings in 73.7% (14/19) cases, discordant findings in 15.8% (3/19) cases, and additional findings in 10.5% (2/19) cases when compared with prenatal ultrasound. Pm-MRI findings were concordant with autopsy in all 8 CHD cases terminated over 13+6 weeks. CONCLUSION: It is feasible to exhibit the structure of fetal heart terminated in the first trimester clearly on 9.4-T pm-MRI with an optimized scanning protocol. High-field pm-MRI could provide medical imaging information of CHD for those terminated in the early stage of gestation, especially for those limited by conventional autopsy.

11.
Cell Mol Immunol ; 18(4): 979-991, 2021 04.
Artigo em Inglês | MEDLINE | ID: mdl-33707686

RESUMO

Immune activation at the maternal-fetal interface is a main pathogenic factor of preeclampsia (PE). Neutrophils (PMNs) are activated in PE patients, but the mechanism and consequences of PMN activation need to be further explored. Here, we demonstrated that interleukin-32 (IL-32) expression was significantly upregulated in syncytiotrophoblasts (STBs) and that IL-32ß was the major isoform with increased expression in the placenta of severe PE (sPE) patients. Furthermore, the level of IL-32 expression in the placenta was correlated with its level in the serum of sPE patients, indicating that IL-32 in the serum is derived mainly from the placenta. Then, in vitro experiments showed that IL-32ß could highly activate PMNs and that these IL-32ß-activated PMNs were better able to adhere to endothelial cells (HUVECs) and enhance the expression of vascular cell adhesion molecule-1 (VCAM-1) and intercellular cell adhesion molecule-1 (ICAM-1) in HUVECs, which could be reversed by preincubation with the NADPH oxidase inhibitor VAS 2870. In addition, we showed that IL-32ß mainly activated PMNs by binding to proteinase 3. Finally, IL-32ß administration induced a PE-like phenotype in a pregnant mouse model. This study provides evidence of the involvement of IL-32ß in the pathogenesis of PE.


Assuntos
Endotélio Vascular/imunologia , Interleucinas/metabolismo , Neutrófilos/imunologia , Fagocitose , Placenta/metabolismo , Pré-Eclâmpsia/patologia , Animais , Células Cultivadas , Feminino , Humanos , Interleucinas/genética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pré-Eclâmpsia/etiologia , Pré-Eclâmpsia/metabolismo , Gravidez
12.
Talanta ; 174: 301-306, 2017 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-28738584

RESUMO

This paper reports accurate synthesis of a new type of surface-enhanced Raman spectroscopy (SERS) substrate based on gold nanoparticles decorated 201 red silanized diatomaceous supports. The developed SERS substrate is easy to fabricate, cost effective and offers sensitive rapid detection. The performance and stability of the SERS substrate was investigated and the results showed good SERS activity of substrate that can last for more than 6 months. Tiazophos and phosmet pesticides in aqueous solutions can be detected clearly at a low concentration of 0.01mg/L. The new substrate was applied to detect triazophos in apple pulp at 0.2mg/kg. The results indicate that this substrate have good potential in rapid monitoring of pesticide residues in fruits and could be suitable for field-based applications, and routine laboratory analysis of chemicals.

13.
J Food Sci ; 77(5): T105-9, 2012 May.
Artigo em Inglês | MEDLINE | ID: mdl-22489549

RESUMO

An ultrasensitive method based on Surface enhanced Raman scattering (SERS) has been developed to determine content of a pesticide which is tricyclazole in paddy rice using sliver colloid as a substrate and pyridine as an internal standard. The peaks at 424 and 1035 cm(-1) in a SERS spectrum were selected as analytic and internal peaks, respectively, and their intensity ratio I(t)/I(p) was used to calculate the regression concentration of tricyclazole. The correlation between I(t)/I(p) and concentration showed significant linear relationship with a correlation coefficient of R(2)= 0.995 in a concentration range of 0.05 to 0.70 mg/L and the tricyclazole solution can be detected to be low as 0.002 mg/L by SERS. The method was applied to determine tricyclazole contents of 3 real rice samples with a standard addition method in order to eliminate interference of matrix. The errors of SERS measurements for the 3 samples were 0.0008 to 0.0246, 0.0013 to 0.0028, and 0.0129 to 0.0304 mg/kg, respectively, compared with the results obtained by high performance liquid chromatography method. This also showed a good reproducibility with low values of relative standard deviation (n= 3) for the 3 samples ranged from 3.63% to 4.64%.


Assuntos
Oryza/química , Resíduos de Praguicidas/análise , Análise Espectral Raman/métodos , Tiazóis/análise , Calibragem , Cromatografia Líquida de Alta Pressão , Coloides/química , Limite de Detecção , Piridinas/análise , Reprodutibilidade dos Testes , Prata/análise , Prata/química
14.
Anal Chim Acta ; 670(1-2): 39-43, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20685414

RESUMO

A micro near infrared spectroscopy (MicroNIRS) technique based on monolithic column enrichment has been developed to detect low concentration metallic ions in water. Glycidyl methacrylate-ethylene dimethacrylate-iminodiacetic acid (GMA-EDMA-IDA) monolithic material was synthesized to construct an enrichment device, which can enrich metallic ions more efficiently than chelating resin materials such as D401. Cu(2+) solutions passed through the enrichment device and concentrated on the surface of the material, and then diffuse reflection NIR (DRNIR) spectra were measured by touching the NIR probe on the surface. The spectra were pretreated with multiplicative scatter correction (MSC) and the MSC-pretreated spectra showed high linear correlation to the Cu(2+) concentrations in spectral regions of 900-1350 nm, 1420-1480 nm and 1970-2050 nm for all concentration ranges. PLS models built with leave-one-out cross-validation also yielded good features. The mean relative error (MRE) of prediction was 10.0% in the 0.0001-0.0010 microg mL(-1) range. The concentration has low to ppb-level, but the MRE was not more than 10%, which was acceptable for trace analysis. The results revealed that the MicroNIRS technique enhanced the sensitivity of NIRS dramatically and widened the NIRS technique to micro and trace analysis field.


Assuntos
Cobre/análise , Compostos de Epóxi/química , Iminoácidos/química , Metacrilatos/química , Espectroscopia de Luz Próxima ao Infravermelho/métodos , Poluentes Químicos da Água/análise
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