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1.
Heart ; 2020 May 07.
Artigo em Inglês | MEDLINE | ID: mdl-32381650

RESUMO

OBJECTIVE: Whether lipoprotein(a) (Lp(a)) is a predictor for recurrent cardiovascular events (RCVEs) in patients with coronary artery disease (CAD) has not been established. This study, hence, aimed to examine the potential impact of Lp(a) on RCVEs in a real-world, large cohort of patients with the first cardiovascular event (CVE). METHODS: In this multicentre, prospective study, 7562 patients with angiography-diagnosed CAD who had experienced a first CVE were consecutively enrolled. Lp(a) concentrations of all subjects were measured at admission and the participants were categorised according to Lp(a) tertiles. All patients were followed-up for the occurrence of RCVEs including cardiovascular death, non-fatal myocardial infarction and stroke. RESULTS: During a mean follow-up of 61.45±19.57 months, 680 (9.0%) RCVEs occurred. The results showed that events group had significantly higher Lp(a) levels than non-events group (20.58 vs 14.95 mg/dL, p<0.001). Kaplan-Meier analysis indicated that Lp(a) tertile 2 (p=0.001) and tertile 3 (p<0.001) groups had significantly lower cumulative event-free survival rates compared with tertile 1 group. Moreover, multivariate Cox regression analysis further revealed that Lp(a) was independently associated with RCVEs risk (HR: 2.01, 95% CI: 1.44 to 2.80, p<0.001). Moreover, adding Lp(a) to the SMART risk score model led to a slight but significant improvement in C-statistic (∆C-statistic: 0.018 (95% CI: 0.011 to 0.034), p=0.002), net reclassification (6.8%, 95% CI: 0.5% to 10.9%, p=0.040) and integrated discrimination (0.3%, 95% CI: 0.1% to 0.7%, p<0.001). CONCLUSIONS: Circulating Lp(a) concentration was indeed a useful predictor for the risk of RCVEs in real-world treated patients with CAD, providing additional information concerning the future clinical application of Lp(a).

2.
J Transl Med ; 18(1): 195, 2020 May 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398139

RESUMO

BACKGROUND: Green tea drinking has been proven to lower lipid and exert cardiovascular protection, while the potential mechanism has not been fully determined. This study was to investigate whether the beneficial impact of epigallocatechingallate (EGCG), a type of catechin in green tea on lipids is associated with proprotein convertase subtilisin/kexin type 9 (PCSK9) pathways. METHODS: We studied the effects and underlying molecular mechanism of EGCG or green tea on regulating cholesterol from human, animal and in vitro. RESULTS: In the age- and gender-matched case control observation, we found that individuals with frequent tea consumption (n = 224) had the lower plasma PCSK9 and low density lipoprotein cholesterol (LDL-C) levels compared with ones without tea consumption (n = 224, p < 0.05). In the high fat diet (HFD) fed rats, EGCG administration significantly lowered circulating PCSK9 concentration and liver PCSK9 expression, along with up-regulated LDL receptor (LDLR) expression but decreased level of LDL-C. In hepatic cell study, similar results were obtained regarding the impact of EGCG on LDLR and PCSK9 expression. The assay transposase-accessible chromatic with high-throughput sequencing (ATAC-seq) and subsequent results suggested that two transcription factors, hepatocyte nuclear factor-1α (HNF-1α) and forkhead box class O (FoxO) 3a involved in inhibitory action of EGCG on PCSK9 expression. CONCLUSIONS: The present study demonstrates that EGCG suppresses PCSK9 production by promoting nuclear FoxO3a, and reducing nuclear HNF1α, resulting in up-regulated LDLR expression and LDL uptake in hepatocytes. Thereby inhibiting liver and circulating PCSK9 levels, and ultimately lowering LDL-C levels.

3.
Int J Biol Macromol ; 155: 588-597, 2020 Mar 28.
Artigo em Inglês | MEDLINE | ID: mdl-32234445

RESUMO

In the current study, we found an interesting phenomenon that fresh egg white (EW) undergo the sol-gel-sol transition with alkali treatment. The transformation behavior at different alkalinity (1.5%, 2.0%, and 2.5%) was investigated. As the gel formed, the hardness, lightness, surface hydrophobicity and the total number of identified peptides increased, and then, remarkable reduction when the gel collapsed. Rheological behavior indicated that the viscosity varied with shear rate. Fourier transform infrared spectroscopy (FTIR) showed that ß-sheets gradually decreased as the α-helices increased during gel-sol transformation. The quantification of EW peptides analysis revealed that there was no dramatic correlation between the number of identified peptides and alkalinity. It was concluded that the sol-gel-sol transition was strongly dependent on alkali levels, moreover, high concentration promoted gel formation as well as liquefaction. The EW transformation behavior induced by alkali had a significant effect on protein aggregation and denaturation, and further changed physicochemical properties.

4.
Cardiovasc Diabetol ; 19(1): 45, 2020 Apr 03.
Artigo em Inglês | MEDLINE | ID: mdl-32245386

RESUMO

BACKGROUND: Elevation in small dense low-density lipoprotein (sdLDL) is common in patients with diabetes mellitus (DM), which has already been reported to be associated with incidence of coronary artery disease (CAD). The aim of the present study was to investigate the prognostic value of plasma sdLDL level in patients with stable CAD and DM. METHODS: A total of 4148 consecutive patients with stable CAD were prospectively enrolled into the study and followed up for major cardiovascular events (MACEs) up to 8.5 years. Plasma sdLDL level was measured in each patient by a direct method using automated chemistry analyzer. The patients were subsequently divided into four groups by the quartiles of sdLDL and the association of sdLDL level with MACEs in different status of glucose metabolism [DM, Pre-DM, normal glycaemia regulation (NGR)] was evaluated. RESULTS: A total of 464 MACEs were documented. Both Kaplan-Meier analysis and Cox regression analysis indicated that the patients in quartile 4 but not quartile 2 or 3 of sdLDL level had significantly higher rate of MACEs than that in lowest quartile. When the prognostic value of high sdLDL was assessed in different glucose metabolism status, the results showed that the high sdLDL plus DM was associated with worse outcome after adjustment of confounding risk factors (hazard ratio: 1.83, 95% confident interval: 1.24-2.70, p < 0.05). However, no significant association was observed for high sdLDL plus Pre-DM or NGR. CONCLUSIONS: The present study firstly indicated that elevated levels of plasma sdLDL were associated with increased risk of MACEs among DM patients with proven CAD, suggesting that sdLDL may be useful for CAD risk stratification in DM.

5.
Nanoscale ; 12(15): 8248-8254, 2020 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-32239032

RESUMO

Probes functioning in the second near-infrared window (1000-1700 nm, NIR-II) exhibit higher resolution and diminished auto-fluorescence compared to those in the traditional NIR region (700-950 nm). Here, we designed and synthesized rare earth ion doped probes with core/shell/shell structures and bright luminescence in the NIR-II region excited at 808 nm. With the doping of Ce3+ ions, the emission intensity of Er3+ at 1530 nm increased 10 times, while the upconversion luminescence decreased to less than 1%. After being modified with polyacrylic acid and polyethylene glycol, the as-obtained water-soluble probe exhibits continuous high-resolution for distinguishing 0.25 mm blood vessels even 10 h after injection. Noteworthily, the imaging of tumors was achieved by injecting the probe, indicating that the designed NIR-II probe has sufficient brightness and the ability to passively target tumor tissue.

6.
PLoS One ; 15(4): e0231497, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32287291

RESUMO

Salt stress is one of the major environmental constraints for plant growth. Although the ways in which mycorrhizal plants deal with salt stress have been well documented, it still is blank for Euonymus maackii, an important local ecological restoration tree, to arbuscular mycorrhizal fungi (AMF) inoculation and salt stress. In this study, we tested the effect of different salt levels (0, 50, 100,150 and 200 mM) and AMF inoculation on E. maackii growth rate, photosynthesis, antioxidant enzymes, nutrient absorption and salt ion distribution. The results indicated negative effect of salt on height, photosynthesis capacity, nutrition accumulation, while salt stimulated the antioxidant defense system and salt ions accumulation. The toxic symptom by excessive accumulation of salt ions worsen with salt level increased gradually (except for the 50 mM NaCl treatment). AMF inoculation alleviated the toxic symptom under moderate salt levels (100 and 150 mM) by increasing photosynthesis capacity, accelerating nutrient absorption and activating antioxidant enzyme activities under salt stress. Meanwhile, effect of AMF was not detected on seedlings under slight (0 and 50 mM) and high (200 mM) NaCl concentration. Our study indicated AMF had positive impact on E. maackii subjected to salt, which suggested potential application of AMF- E. maackii on restoration of salt ecosystems.

7.
Pain Manag Nurs ; 2020 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-32278530

RESUMO

BACKGROUND: The relationship between pain and mortality risk has not been well established. AIMS: This study aimed to assess the possible association between a chief complaint of pain and in-hospital mortality. DESIGN: Retrospective cohort study using 11-year hospital administrative data. SETTING: Southwest Hospital of Third Military Medical University (Chongqing, China). PARTICIPANTS: A total of 645,998 adult inpatients admitted without department limitation between January 1, 2003, and December 31, 2013. METHODS: Information on the chief complaint at admission was obtained, and the main outcome measure was in-hospital mortality. RESULTS: The crude overall in-hospital mortality rate for patients admitted with chief complaint of pain was 958 (3.9%), which was significantly lower than that of patients without pain (1,970, 4.9%). The risk of hospital death for inpatients admitted with pain was 21% lower compared to inpatients admitted without pain (p < .001). Female patients with a chief complaint of pain had a lower risk of in-hospital mortality (p < .001) compared with male patients (p < .001). When stratified by location of pain, patients with chest pain had a significantly higher risk of in-hospital mortality compared with those without complaint of pain (p < .001), whereas for patients with a chief complaint of waist, abdominal, limb, or joint pain, the risk of hospital death was lower compared with cases without pain. CONCLUSIONS: The present study suggested that inpatients admitted with a chief complaint of pain might have a significantly lower risk of in-hospital mortality compared with those admitted without a chief complaint of pain.

8.
Nanoscale ; 12(10): 6096-6103, 2020 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-32129393

RESUMO

Integration of diagnostic and therapeutic components into a single coordination polymer nanoparticle is desirable for theranostic applications, but still challenging. Herein, we report the synthesis of bimetal-phenolic coordination polymer nanoparticles using gadolinium nitrate and ferrous sulphate as a metal source, and plant polyphenols (i.e., tannic acid) as an organic ligand via a metal-catechol coordination assembly process. Such coordination polymers show a tunable molar ratio of Gd/Fe and high dispersibility and stability in aqueous solution. The coordination polymers reveal composition-dependent performance for longitudinal relaxivity and photothermal conversion. The longitudinal relaxivity is positively related to the molar ratio of Gd/Fe, while the photothermal performance is negatively related to the molar ratio of Gd/Fe in the coordination polymers. The coordination polymers with an optimized molar ratio of Gd/Fe exhibit an ultra-small hydrodynamic diameter (∼23 nm), a high r1 value (9.3 mM-1 s-1) with low r2/r1 (1.26) and high photothermal conversion efficiency (η = 37%). They can be used as a contrast agent for T1-weighted magnetic resonance imaging of EMT-6 tumor bearing mice, which can effectively enhance the signals of tumors. They can also effectively suppress tumor growth via photothermal therapy. This work brings new insights for the synthesis of multifunctional coordination polymer nanoparticles and extending their potential applications in theranostics.

9.
Arch Gynecol Obstet ; 301(5): 1247-1255, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32221709

RESUMO

PURPOSE: This retrospective study compared the efficacy and survival of patients with cervical adenocarcinoma (IB2/IIA2; FIGO2009) treated with neoadjuvant chemotherapy before radical surgery (NACT + RS), neoadjuvant chemoradiation therapy before radical surgery (NACRT + RS), or primary radical surgery (RS). METHODS: Between January 2008 and November 2015, 91 patients diagnosed with stage IB2/IIA2 cervical adenocarcinoma were enrolled, including 29 patients who received RS, 24 patients who received NACT + RS, and 38 patients who received NACRT + RS. RESULTS: The characteristics of patients were balanced among the three groups, and the median follow-up time was 72 months. The 5 year disease-free survival (DFS) rate was 75.8% and the 5 year overall survival (OS) rate was 85.0%. Univariate analysis revealed that effectiveness of neoadjuvant treatment, tumor size, lymph node metastases, and depth of stromal invasion were the factors predicting recurrence and mortality. Multivariate Cox proportional analysis revealed that the occurrence of a lymph node metastasis was an independent prognostic factor of DFS (hazard ratio [HR] = 0.223; 95% confidence interval [CI]: 0.060-0.827) and OS (HR = 0.088; 95% CI: 0.017-0.470). On survival analysis of preoperative adjuvant chemotherapy and primary surgery, the 5 year OS (P = 0.010) and DFS (P = 0.016) rates for the NACRT + RS group were significantly lower than those for the RS group. CONCLUSION: Stage IB2/IIA2 cervical adenocarcinoma patients who received primary RS had a better DFS and OS than those who received preoperative NACRT. There was no significant difference when compared to the preoperative NACT group.

10.
Anal Chem ; 92(7): 5540-5545, 2020 Apr 07.
Artigo em Inglês | MEDLINE | ID: mdl-32141734

RESUMO

The enzyme-linked immunosorbent assay (ELISA) is widely used in clinical diagnostics. However, conventional ELISA is labor-intensive and lengthy. Herein, the sensitive detection of biomarkers with only one-step incubation of 20 min is demonstrated, based on antibody-fused, boronic-acid-decorated carbon nitride nanosheets. The decoration of carbon nitride nanosheets with boronic acid facilitates antibody binding at physiological conditions along with a concomitant fluorescence enhancement. The presence of target antigen results in a decrement of the fluorescence and ensures one-step immunofluorescent detection. The immune recognition of the antibody/target antigen in combination with glucose blocking ensures a highly selective assay of the biomarkers. The protocol is validated by the assay of nonglycoprotein, glycoprotein, and small-molecular-toxin targets. The multiplex target detection capability is demonstrated by the simultaneous assay of the triple cardiac biomarker cTnI, Mb, and CK-MB in human serum.

11.
Braz J Infect Dis ; 2020 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-32201125
12.
Cardiovasc Diabetol ; 19(1): 36, 2020 Mar 19.
Artigo em Inglês | MEDLINE | ID: mdl-32192491

RESUMO

BACKGROUND: The present cohort study aims to examine the relationship between fibrinogen (Fib) levels and glucose metabolism [fasting blood glucose (FBG) and hemoglobin A1c (HbA1c)] and investigate the impact of high Fib on cardiovascular outcomes in patients with stable CAD and pre-diabetes mellitus (pre-DM) or diabetes mellitus (DM). METHODS: This study included 5237 patients from March 2011 to December 2015. Patients were distributed into three groups according to Fib levels (low Fib, median Fib, high Fib) and further categorized by glucose metabolism status [normal glucose regulation (NGR), Pre-DM, DM]. All patients were followed up for the occurrences of major adverse cardiovascular events (MACEs), including cardiovascular mortality, nonfatal MI, stroke, and unplanned coronary revascularization. RESULTS: Linear regression analyses showed that FBG and HbA1c levels were positively associated with Fib in overall CAD participants, either with or without DM (all P < 0.001). During an average of 18,820 patient-years of follow-up, 476 MACEs occurred. High Fib was independently associated with MACEs after adjusting for confounding factors [Hazard Ratio (HR): 1.57, 95% confidence interval (CI) 1.26-1.97, P < 0.001]. Furthermore, DM but not pre-DM was a significant predictor of MACEs (P < 0.001 and P > 0.05, respectively). When patients were stratified by both glucose metabolism status and Fib levels, high Fib was associated with a higher risk of MACEs in pre-DM (HR 1.66, 95% CI 1.02-2.71, P < 0.05). Medium and high Fib levels were associated with an even higher risk of MACEs in DM (HR 1.86, 95% CI 1.14-3.05 and HR 2.28, 95% CI 1.42-3.66, all P < 0.05). After adding the combination of Fib and glucose status to the Cox model, the C-statistic was increased by 0.015 (0.001-0.026). CONCLUSIONS: The present study suggested that Fib levels were associated with FBG and HbA1c in stable CAD patients. Moreover, elevated Fib was independently associated with MACEs in CAD patients, especially among those with pre-DM and DM, suggesting that Fib may provide incremental value in the cardiovascular risk stratification of pre-DM and DM patients.

14.
Materials (Basel) ; 13(6)2020 Mar 11.
Artigo em Inglês | MEDLINE | ID: mdl-32168807

RESUMO

GaAs monolithic microwave integrated circuits (MMICs) with different back metallization systems (TiW/Au and Au/Ti/Au) exhibit different problems in the automatic Au-Sn eutectic bonding process, such as edge breakage or excessive voids. In this study, the formation mechanism of the edge breakage and excessive voids were investigated to prevent the damage of the MMICs in mass production scenarios. The microstructure and elemental distribution were studied using a scanning electron microscope and energy-dispersive spectroscopy. The void contents of the brazed region were measured with three-dimensional computed tomography. The top Au layer of the TiW/Au metallization partially dissolved in the melting An-Sn solder. Consequently, liquidus temperature of the solder increased, leading to isothermal solidification with the formation of ζ-Au5Sn in the scrubbing process, which was the reason for the edge breakage. The terminal Au film of the Au/Ti/Au metallization completely dissolved in the melting An-Sn solder. The metallurgical combination was achieved by the formation of the TiAu4 intermetallic compound between the Au-Sn solder and the Ti layer. The wettability of Au-Sn solder on Ti layer should be improved to prevent the formation of the excessive voids.

15.
Parasitol Res ; 119(3): 1035-1041, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32072328

RESUMO

Telomerase plays a crucial role in ageing and tumourigenesis. However, the regulatory network of its activity is complicated and not fully understood. In the present study, a yeast two-hybrid screen identified a homologue of human replication factor C subunit 1 (RFC1) as a novel interacting protein of Giardia duodenalis GdTRBD (Giardia duodenalis telomerase ribonucleoprotein complex RNA binding domain GdTRBD). This interaction was further verified via GST pull-down in vitro and co-immunoprecipitation (Co-IP) and bimolecular fluorescence complementation (BiFC) in vivo. We also found that GdRFC1 (Giardia duodenalis replication factor C subunit 1) only interacted with GdTRBD in one nucleus in Giardia duodenalis via a proximity ligation assay (PLA). We reasoned that the two nuclei might have significant heterogeneity in their functional activities during the trophozoite stage and that the two molecules might be involved in other unidentified functions in addition to telomerase activity. In addition, knockdown of GdRFC1 decreased telomerase activity. Collectively, our results indicate that GdRFC1 is a novel binding partner and positive regulator of telomerase in Giardia duodenalis.

16.
J Am Heart Assoc ; 9(3): e014581, 2020 Feb 04.
Artigo em Inglês | MEDLINE | ID: mdl-32013705

RESUMO

Background Although several studies have indicated that lipoprotein(a) is a useful prognostic predictor for patients following percutaneous coronary intervention (PCI), previous observations have somewhat been limited by either small sample size or short-term follow-up. Hence, this study aimed to evaluate the impact of lipoprotein(a) on long-term outcomes in a large cohort of stable coronary artery disease patients after PCI. Methods and Results In this multicenter and prospective study, we consecutively enrolled 4078 stable coronary artery disease patients undergoing PCI from March 2011 to March 2016. They were categorized according to both the median of lipoprotein(a) levels and lipoprotein(a) values of <15 (low), 15 to 30 (medium), and ≥30 mg/dL (high). All patients were followed up for occurrence of cardiovascular events, including cardiovascular death, nonfatal myocardial infarction, and stroke. During an average of 4.9 years of follow-up, 315 (7.7%) cardiovascular events occurred. The events group had significantly higher lipoprotein(a) levels than the nonevents group. Compared with the low lipoprotein(a) group, Kaplan-Meier analysis showed that the high lipoprotein(a) group had a significantly lower cumulative event-free survival rate, and multivariate Cox regression analysis further revealed that the high lipoprotein(a) group had significantly increased cardiovascular events risk. Moreover, adding continuous or categorical lipoprotein(a) to the Cox model led to a significant improvement in C-statistic, net reclassification, and integrated discrimination. Conclusions With a large sample size and long-term follow-up, our data confirmed that high lipoprotein(a) levels could be associated with a poor prognosis after PCI in stable coronary artery disease patients, suggesting that lipoprotein(a) measurements may be useful for patient risk stratification before selective PCI.

17.
Cardiovasc Diabetol ; 19(1): 15, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-32041617

RESUMO

BACKGROUND: Heart-type fatty acid-binding protein (H-FABP) is a novel marker of myocardial injury and has been reported to be associated with cardiovascular diseases (CVD) including patients with diabetes mellitus (DM). Unfortunately, its prognostic value in patients with CVD and impaired glucose metabolism (IGM) is unclear. The objective of this study was to investigate the prognostic value of H-FABP in CVD patients with IGM. METHODS: A total of 4594 patients with angiography-proven coronary artery disease (CAD) were enrolled and divided into subgroup according to glucose metabolism status (normal glucose regulation [NGR], pre-DM, and DM). Baseline levels of H-FABP were measured using latex immunoturbidimetric method. The cardiovascular events (CVE) were defined as cardiovascular death, myocardial infarction, stroke and coronary revascularization. Cox regression and Kaplan-Meier analysis were used to evaluate the relations of H-FABP and glucose metabolism status to CVEs. RESULTS: During the follow-up period with up to 7.1 years, 380 CVEs occurred. Patients with CVE had higher levels of H-FABP compared to those without CVE (p < 0.001). Interestingly, H-FABP levels were also elevated in DM and pre-DM groups compared with NGR group (p < 0.001), when combined glucose metabolism status with H-FABP stratification, patients in the highest tertile of H-FABP appeared to have higher risk of CVEs with pre-DM (adjusted hazard ratio [HR]: 1.855, 95% confidential intervals [CIs] 1.076-3.214; p = 0.033) and DM (adjusted HR: 2.560, 95% CIs 1.409-4.650; p = 0.002). The Kaplan-Meier curve indicated that DM patients with the highest H-FABP levels were associated with the greatest risk of CVEs (p < 0.05). CONCLUSIONS: Our data firstly showed that elevated H-FABP levels were associated with worse outcomes in CAD patients with pre-DM and DM, which provided the novel information that H-FABP might be a prognostic marker for clinical outcomes among patients with CAD and IGM.

18.
J Agric Food Chem ; 68(7): 1948-1957, 2020 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-32009394

RESUMO

As one of six dietary nutrients, lipid derived from different food matrices has been extensively studied and has an appropriate application in food, medicine, and cosmetic industry. Egg is a richly nutritive food, of which proteins and lipids possess excellent functional characteristics and biological activities. In recent years, egg yolk lipid has been successively separated and investigated, such as egg yolk oil, phospholipids, and fatty acids, which have anti-inflammatory activity, antioxidant activity, cardiovascular protection, and memory improvement, involving the regulation of cell function and physiological homeostatic balance. In this paper, the biological activities and underlying benefit of egg yolk lipids and fat-soluble components have been highlighted and summarized. Meanwhile, the quantitative data of egg yolk lipids needed to achieve any of the described biological effects and recommended concentrations relevant for dietary intake are reviewed. Finally, current challenges and crucial issues of high-efficiency utilization of egg yolk lipids are also discussed.


Assuntos
Gema de Ovo/química , Lipídeos/farmacologia , Animais , Galinhas , Humanos , Lipídeos/química
19.
Sensors (Basel) ; 20(4)2020 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-32098377

RESUMO

Spectral imaging is a promising technique for detecting the quality of rice seeds. However, the high cost of the system has limited it to more practical applications. The study was aimed to develop a low-cost narrow band multispectral imaging system for detecting rice false smut (RFS) in rice seeds. Two different cultivars of rice seeds were artificially inoculated with RFS. Results have demonstrated that spectral features at 460, 520, 660, 740, 850, and 940 nm were well linked to the RFS. It achieved an overall accuracy of 98.7% with a false negative rate of 3.2% for Zheliang, and 91.4% with 6.7% for Xiushui, respectively, using the least squares-support vector machine. Moreover, the robustness of the model was validated through transferring the model of Zheliang to Xiushui with the overall accuracy of 90.3% and false negative rate of 7.8%. These results demonstrate the feasibility of the developed system for RFS identification with a low detecting cost.

20.
Anal Chem ; 92(5): 3769-3774, 2020 Mar 03.
Artigo em Inglês | MEDLINE | ID: mdl-31931569

RESUMO

Alkaline phosphatase (ALP) plays critical roles in signal transmission and cell growth/apoptosis. Its abnormal level in serum/cell is tightly related to diseases, thus, serum and cellular ALP detection is of great significance for disease diagnosis. Herein, a novel approach for ALP assay based on a satellite-nanostructure is developed by conjugating lanthanide upconversion nanoparticles (UCNPs) with silver nanoclusters (AgNCs) through DNA bridging. UCNPs serve as the cores to conjugate with DNA fragments, followed by assembly of AgNCs as the satellites on UCNPs surface through the AgNCs-cytosine affinity, to produce the satellite-nanostructure of UCNPs@DNA-AgNCs. The presence of ALP converts phosphate groups into hydroxyl groups at DNA helix, weakening the coordination of DNA with UCNPs. As a result, the satellite AgNC labeling on DNA fragments strips off the UCNP surface. Silver is quantified by measuring isotope 107Ag with ICP-MS, which further derives the content of ALP by correlation to the number of AgNCs. A linear calibration range is obtained in 0.005-120 U/L with a detection limit of 1.8 mU/L. The distinct advantage of this strategy, on one hand, is the substrate-free feature that eliminates the intermediate process of substrate reaction, where the substrate activity decrease and its instability may significantly deteriorate the sensitivity. On the other hand, ALP triggers the production of a large number of AgNCs resulting in substantial amplification on ICP-MS signal to give a favorable sensitivity. This is the first attempt for ALP detection by inductively coupled plasma mass spectrometry.

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