The relationship between papillary thyroid cancer and triglyceride/glucose index, which is an indicator of insulin resistance.

OBJECTIVE: The incidence of thyroid cancer and metabolic syndrome has been increasing at the same rate over the past few decades. We hypothesized that there would be a direct relationship between thyroid papillary cancer and triglyceride/glucose index (TyG). PATIENTS AND METHODS: A total of 382 operated patients were divided into two groups: patients operated on for papillary thyroid cancer and for non-malignant reasons. Each patient's age, gender, operation times, presence of neck dissection, serum thyroid-stimulating hormone (TSH), free triiodothyronine (FT3) and free thyroxine (FT4), fasting blood glucose and triglyceride levels were scanned retrospectively from the archive system. RESULTS: TyG index was statistically higher in the malignant group. Receiver operating characteristic (ROC) curves obtained for TyG levels at the time of diagnosis of thyroid papillary cancer were AUC: 0.608. The threshold value for TyG was 6,252. The sensitivity of this value was 62.8% and the specificity was 49.2%. CONCLUSIONS: In this study, we investigated the predictive effect of the TyG index in differentiating thyroid papillary carcinoma from non-malignant thyroid lesions. We concluded that the TgY index can be used to identify people at high risk of thyroid papillary cancer and to plan treatment.

Assessing related factors to fasting blood sugar and glycosylated hemoglobin in patients with type 2 diabetes simultaneously by a multivariate longitudinal marginal model.

The multivariate marginal model can be used to simultaneously examine the factors affecting both FBS and HbA1c using longitudinal data. The model fitted to multivariate longitudinal data should prevent redundant parameter estimation in order to have greater efficiency. In this study, a multivariate marginal model is used to simultaneously investigate the factors affecting both FBS and HbA1c with longitudinal data for patients with type 2 diabetes in Northern Iran. The present research is a retrospective cohort study. Overall, 500 medical records with complete information were reviewed. The multivariate marginal model is used to determine the factors associated with FBS and HbA1c using longitudinal data. Data have been analyzed in R-3.4.0 using 'mmm2' package. Given that the coefficients for the interactions of rtype with the intercept, time, family history of diabetes, history of hypertension, history of smoking, insulin therapy, systolic/diastolic blood pressure and duration of disease at first visit are significantly different from zero (P < 0.05), the effect of the independent variables on the two response variables is different and different coefficients should be used for each. Therefore, the interactions of these variables with rtype are kept in the final model. The coefficients for the interactions of rtype with sex, age at first visit, history of high cholesterol, and weight are not significantly different from zero (P > 0.05), indicating that their effect on the two response variables is similar and only one coefficient should be used for each. We examined the similarity of coefficients when fitting the longitudinal multivariate model for the relationship between FBS/HbA1c and sex, age, history of high blood cholesterol, and body weight. If an independent variable has similar effects on both responses, only one coefficient should be estimated, which will increase the efficiency of the model and the reliability of the results.

Newly diagnosed diabetes based on an oral glucose tolerance test predicts cardiovascular outcomes in patients with coronary artery disease: An observational study.

Diabetes is prevalent in patients with coronary artery disease (CAD). Using the oral glucose tolerance test (OGTT), abnormal glucose regulation can be detected early in CAD patients without known diabetes. In the present study, we assessed the impact of abnormal glucose regulation on the long-term cardiovascular outcomes of patients with established CAD. Patients hospitalized for a scheduled angiography due to angina were enrolled in Taichung Veterans General Hospital. Fasting plasma glucose (FPG) and 2-hour postload glucose (2hPG) were assessed using the OGTT. Hemoglobin A1c (HbA1c) and other biochemical analyses were assessed using fasting blood samples. During a median follow-up period of 4.6 years, a composite of all-cause mortality, nonfatal myocardial infarction, and nonfatal stroke was recorded as the primary endpoint. In 682 enrolled patients who completed the follow-up, there were 16 myocardial infarction events, 12 stroke events, and 58 deaths as composite endpoints. According to FPG and 2hPG, patients with newly diagnosed diabetes had a 2-fold higher risk for the composite endpoint than those in the normal glucose group (hazard ratio [HR], 2.011; 95% confidence interval (CI), 1.101-3.673; P = .023); however, prediabetes was not significantly associated with the composite endpoint (HR, 1.452; 95% CI, 0.788-2.675; P = .232). On the other hand, patients with diabetes diagnosed by FPG and HbA1c did not have a significantly higher risk for the composite endpoint than those in the normal glucose group (HR, 1.321; 95% CI, 0.686-2.545; P = .405). A 2hPG ≥7.8 mmol/L was a significant predictor for the composite endpoint (odds ratio, 1.743; 95% CI, 1.060-2.863; P = .028) after adjusting for age, sex, and estimated glomerular filtration rate. Diabetes, but not prediabetes, detected via OGTT is associated with a significantly increased risk for the composite endpoint in patients with established CAD. The 2hPG provided a greater predictive power for the composite endpoint than fasting glucose and HbA1c.

Abnormal glucose regulation in Chinese patients with coronary artery disease: a gender analysis.

BACKGROUND: Diabetes and impaired glucose regulation are very common in patients with coronary artery disease (CAD). In this study, we aim to investigate the prevalence of abnormal glucose regulation in men and women in Chinese CAD patients. METHODS: In this retrospective study, 4100 patients (male, n = 2873; female, n = 1227)with CAD were enrolled. The mean age of these patients was 63 years. The demographic data, medical history, echocardiography findings and blood investigations were collected and analyzed. RESULTS: In this population, 953 (24%) patients had definite diagnosis of type 2 diabetes mellitus, including 636 males (23%) and 317 females (27%). There was a higher prevalence of diabetes in females than men (p < 0.05). For the remaining patients, 48% (n = 959) undergone an oral glucose tolerance test (OGTT), which revealed that 83 male patients (12%) and 41 female patients (16%) suffered from the type 2 diabetes (p > 0.05). 283 men (40%) and 105 women (41%) had impaired glucose regulation (IGR) (p > 0.05). Only 338 men (25%) and 109 women (19%) showed the normal glucose regulation, implying a higher prevalence of abnormal glucose regulation in females (p < 0.01). The odd ratio (OR) showed that women were more prone to have diabetes mellitus or IGT than men and the OR was 1.44 and 1.43 respectively. CONCLUSION: Abnormal glucose regulation is highly prevalent in CAD patients. The women are more prone to have diabetes mellitus or IGT than men.

Accuracy Assessment of the GlucoMen® Day CGM System in Individuals with Type 1 Diabetes: A Pilot Study.

The aim of this study was to evaluate the accuracy and usability of a novel continuous glucose monitoring (CGM) system designed for needle-free insertion and reduced environmental impact. We assessed the sensor performance of two GlucoMen® Day CGM systems worn simultaneously by eight participants with type 1 diabetes. Self-monitoring of blood glucose (SMBG) was performed regularly over 14 days at home. Participants underwent two standardized, 5-h meal challenges at the research center with frequent plasma glucose (PG) measurements using a laboratory reference (YSI) instrument. When comparing CGM to PG, the overall mean absolute relative difference (MARD) was 9.7 [2.6-14.6]%. The overall MARD for CGM vs. SMBG was 13.1 [3.5-18.6]%. The consensus error grid (CEG) analysis showed 98% of both CGM/PG and CGM/SMBG pairs in the clinically acceptable zones A and B. The analysis confirmed that GlucoMen® Day CGM meets the clinical requirements for state-of-the-art CGM. In addition, the needle-free insertion technology is well tolerated by users and reduces medical waste compared to conventional CGM systems.

Cholesterol and glucose profiles according to different fasting C-peptide levels: a cross-sectional analysis in a healthy cohort from the Czech Republic.

The relationship between glycaemia and lipoprotein metabolism has not been completely clarified, and slight differences may be found between local authors, trials and evaluated parameters. Therefore this cross-sectional study investigated fasting cholesterol and glucose levels along with the determination of atherogenic index in a cohort of healthy individuals from the Czech Republic in relation to their fasting C-peptide levels. Data were collected between 2009 and 2018 and a total of 3189 individuals were stratified by C-peptide reference range (260-1730 pmol/l) into three groups - below (n = 111), within (n = 2952) and above (n = 126). Total, HDL, LDL cholesterol and atherogenic index were used to compare lipoprotein levels by relevant C-peptide concentrations. Participants using the supplements to affect lipid or glycaemia metabolism were excluded from this study. The evaluation of blood parameters in a fasting state included correlations between C-peptide and cholesterols, differences of variances (F-test) and the comparison of lipoprotein mean values (t-test) between the groups created by the C-peptide reference range. Mean values of total (4.9, 5.1, 5.3 mmol/l), LDL (2.6, 3.1, 3.4 mmol/l) cholesterol and atherogenic index (2.1, 2.8, 3.7) were higher with increasing C-peptide levels, whereas HDL was inversely associated with fasting C-peptide concentration. A positive and negative correlation between atherogenic index (rxy = 0.36) and HDL level (rxy = -0.36) with C-peptide values was found. Differences of HDL, LDL and atherogenic index were, in particular, recorded between the groups below and above the reference range of C-peptide (p ≤ 0.001). Considerable differences (p ≤ 0.001) were also observed for the same lipoprotein characteristics between the groups above and within the C-peptide reference. Generally, the type of cholesterol is crucial for the evaluation of specific changes concerning the C-peptide range. Lipoprotein concentrations differ in relation to C-peptide - not only below and above the physiological range, but also inside and outside of it. Conclusions: Fasting levels of cholesterol, plasma glucose, and atherogenic index were strongly associated with fasting C-peptide levels in healthy individuals. Our data suggest that fasting C-peptide could serve as a biomarker for the early detection of metabolic syndrome and/or insulin resistance prior to the manifestation of type 2 diabetes.

Preparation of boronic acid-modified polymer dots under mild conditions and their applications in pH and glucose detection.

For the first time, boronic acid-modified polymer dots (B-PDs) were fabricated by a "synthesis-modification integration" route using polyethylenimine (PEI) and phenylboronic acid as precursors. Under optimized preparation conditions, the B-PDs exhibited an average size of 2.2 nm, good water solubility, and high fluorescence quantum yield of 8.69%. The B-PDs showed reversible fluorescence response in acid solutions (blue emissions) and alkaline solutions (green emissions). The fluorescence emissions of B-PDs demonstrated an obvious red shift with varying the pH value from 1 - 13. Moreover, glucose could assemble on the surface of B-PDs due to the reversible reaction between boronic acid and cis-diols, which resulted in a blue shift of emission wavelength and an obvious increase of FL intensity at λex = 380 nm based on the aggregation-induced enhancement effect. The glucose sensing method was thus developed in the range 0.0001 - 1.0 mol L-1. Applications to real human blood and glucose injection samples demonstrated satisfactory results. The B-PDs based on the analytical method display good selectivity, wide detection range, and simplicity in preparation and detection, implying promising applications as a practical platform for biosensing.

Hydrogen Peroxide-Triggered Conversion of Boronic Acid-Appended Insulin into Insulin and Its Application as a Glucose-Responsive Insulin Formulation.

p-Boronophenylmethoxycarbonyl (BPmoc) is a protecting group for amines that is removable by treatment with hydrogen peroxide (H2O2). We prepared BPmoc-modified insulin (BPmoc-Ins) and subcutaneously injected the formulation into diabetic rats. The results demonstrated that BPmoc effectively sealed the blood glucose (Glc)-lowering effects of Ins. Conversely, coinjection of BPmoc-Ins and Glc oxidase (GOx) resulted in reduced blood Glc levels, indicating that Ins was generated from BPmoc-Ins through the following reactions: oxidation of endogenous Glc by GOx; production of H2O2 accompanied by Glc oxidation; removal of BPmoc residues by H2O2. These results show the potential of BPmoc-Ins for a Glc-responsive Ins release system.

B,N-Doped PdRu Aerogels as High-Performance Peroxidase Mimics for Sensitive Detection of Glucose.

Among plentiful porous nanomaterials, noble metal aerogels taken as nanozymes attract broad attention in sensing applications with their distinct enzyme mimic functions. In the catalytic field, the heteroatom doping strategy is a kind of way with great promise in improving the enzyme mimic activity of noble metal aerogels. In this experiment, we find a type of creative materials that were prepared by the fast and simple method. Due to the unique porous structure and synergetic effect from doped atoms, PdRu aerogels co-doped with boron and nitrogen (B, N-PdRu aerogels) were prepared using NH3BH3 as a reductant, which present improved peroxidase mimicking activity. With the existence of H2O2, the oxidation of 3,3',5,5'-tetramethylbenzidine was catalyzed by B, N-PdRu aerogels fairly efficiently, whose solution would be a blue appearance at optimum absorption wavelength 652 nm. Thus, by the tandem reaction bound to the enzyme glucose oxidase, the B, N-PdRu aerogels can be used for the sensitive determination of glucose. The new method has a good linear detection effect for glucose in the range of 10 µM to 2 mM. The minimum limit of detection can reach as low as 6 µM. This work will contribute to research on the rational design of metal aerogels based on the heteroatomic doping strategy and enhance the corresponding performance for a variety of applications.

Polyvinyl alcohol as a crucial omissible polymer to fabricate an impedimetric glucose biosensor based on hierarchical 3D-NPZnO/chitosan.

Highly stable and reliable monitoring of glucose is of great importance for diabetes patients. This paper describes the application of two types of polymer for developing a reliable impedimetric glucose biosensor by designing an efficient nanoporous microenvironment for enzyme loading. Polyvinyl alcohol (PVA) was used as a sacrifice polymer to prepare a uniform 3D-nanoporous ZnO (3D-NPZnO) platform through electrodeposition of ZnO/PVA layer followed by PVA elimination via annealing. The carbohydrate polymer, chitosan (CTS), with a high isoelectric point (pI = 7.0-9.0), was selected in accompanying with 3D-NPZnO (pI = 9.5) to provide a hierarchical 3D-NPZnO/CTS microenvironment of a favorable isoelectric point for glucose oxidase enzyme (pI = 4.2) loading. The characterization of structural features and monitoring of the biosensor fabrication process was performed using FE-SEM, EDX, TGA-DTG, FTIR, UV-Vis, BET-BJH, XRD, CV, and EIS techniques. The fabricated platform, which shows a wide linear range of 1.0-18.0 mM and a low detection limit of 0.2 mM for glucose determination, was successfully used for real sample analysis. The proposed fabrication method can be applied for immobilizing the other low isoelectric point enzymes and biomolecules.

Electrochemiluminescence sensor based on cyclic peptides-recognition and Au nanoparticles assisted graphitic carbon nitride for glucose determination.

A glucose (Glu) sensor was designed by introducing synthetic cyclic peptides (CPs) as recognition receptors and Au nanoparticles assisted graphitic carbon nitride (AuNPs/g-C3N4) for electrochemiluminescence (ECL) enhancement. The synthetic CP receptor (cyclo-[-CNDNHCRDNDC-]) with natural active center of Glu binding protein can mimic the interactions between Glu and Glu binding protein to specifically capture Glu. The AuNPs were reduced on g-C3N4 and formed a new nanohybrid that can be applied as an ECL emitter. The AuNPs/g-C3N4 effectively ameliorated the ECL response of bare g-C3N4. The ECL enhancement mechanism was theoretically speculated through computer simulation. Glu quantification was conducted by recording ECL shifts induced by the binding of Glu to CPs. The linear detection range of the fabricated CPs-based ECL sensor was 1 to 100 mmol L-1, and the detection limit (LOD) was 0.57 nmol L-1 (S / N = 3). The CP-based ECL sensor also showed good specificity, repeatability, stability, and favorable recoveries in sample analysis. This work offer a promising analytical method for Glu assay in clinical diagnostics and bioprocess monitoring.

Ultrathin PdCu alloy nanosheet-assembled 3D nanoflowers with high peroxidase-like activity toward colorimetric glucose detection.

Enzyme-mimetic properties of nanomaterials can be efficiently tuned by controlling their size, composition, and structure. Here, ultrathin PdCu alloy nanosheet-assembled three-dimensional (3D) nanoflowers (Pd1Cux NAFs) with tunable surface composition are obtained via a generalized strategy. In presence of H2O2, the as-synthesized Pd1Cux NAFs can catalyze the oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) to the oxidized form of TMB (oxTMB) with a characteristic absorption peak at 652 nm. Interestingly, Pd1Cux NAFs show obviously composition-dependent peroxidase-like catalytic activities because of the synergistic interaction of nanoalloy. Additionally, different from 2D Pd nanosheets, the distinctive 3D superstructures are featured with rich approachable sites and proper layer spacing, which are in favor of fast mass transport and electron transfers during the catalytic process. Among the studied Pd1Cux NAFs, the Pd1Cu1.7 NAFs show the highest enzyme-like activities and can be successfully applied for the colorimetric detection of glucose with a low detection limit of 2.93 ± 0.53 µM. This work provides an efficient avenue to fabricate PdCu NAF nanozymes in biosensing toward glucose detection. Two-dimensional (2D) PdCu ultrathin nanosheet-assembled 3D nanoflowers (Pd1Cux NAFs) with tunable surface composition exhibit substantially enhanced intrinsic peroxidase-like catalytic activities. The Pd1Cu1.7 NAFs are successfully used as peroxidase mimic catalyst for the colorimetric detection of glucose with low detection limit of 2.93 µM.

Antioxidants other than vitamin C may be detected by glucose meters: Immediate relevance for patients with disorders targeted by antioxidant therapies.

Owing to their ease of use, glucose meters are frequently used in research and medicine. However, little is known of whether other non-glucose molecules, besides vitamin C, interfere with glucometry. Therefore, we sought to determine whether other antioxidants might behave like vitamin C in causing falsely elevated blood glucose levels, potentially exposing patients to glycemic mismanagement by being administered harmful doses of glucose-lowering drugs. To determine whether various antioxidants can be detected by seven commercial glucose meters, human blood samples were spiked with various antioxidants ex vivo and their effect on the glucose results were assessed by Parkes error grid analysis. Several of the glucose meters demonstrated a positive bias in the glucose measurement of blood samples spiked with vitamin C, N-acetylcysteine, and glutathione. With the most interference-sensitive glucose meter, non-blood solutions of 1 mmol/L N-acetylcysteine, glutathione, cysteine, vitamin C, dihydrolipoate, and dithiothreitol mimicked the results seen on that glucose meter for 0.7, 1.0, 1.2, 2.6, 3.7 and 5.5 mmol/L glucose solutions, respectively. Glucose meter users should be alerted that some of these devices might produce spurious glucose results not only in patients on vitamin C therapy but also in those being administered other antioxidants. As discussed herein, the clinical relevance of the data is immediate in view of the current use of antioxidant therapies for disorders such as the metabolic syndrome, diabetes, cardiovascular diseases, and coronavirus disease 2019.

A facile method for the fabrication of hierarchically structured Ni2CoS4 nanopetals on carbon nanofibers to enhance non-enzymatic glucose oxidation.

Unique Ni2CoS4-carbon nanofiber (CNF) composite nanostructures were fabricated using a simple electrospinning-assisted hydrothermal route and used for the rapid and accurate electrochemical oxidation of glucose in real samples at the trace level. Electrochemical impedance spectroscopy and cyclic voltammetry of unmodified and modified electrodes revealed low charge-transfer resistance and the excellent electrocatalytic sensing of glucose when using the Ni2CoS4-CNF at a low potential due to the combined benefits of the highly conductive Ni2Co2S4 anchored to the large surface area of the CNFs. Amperometric analysis of the fabricated sensor has shown an extremely low limit of detection (0.25 nM) and a large linear range (5-70 nM) for glucose at a working potential of 0.54 V (vs. Hg/HgO). The practicability of the Ni2CoS4-CNF for use in glucose determination was tested withl human saliva, blood plasma, and fruit juice samples. The Ni2CoS4-CNF/GCE showed acceptable recovery values for human saliva (99.1-100.8%), blood plasma (98.6-101.5%), and fruit juice (95.1-105.7%) samples. The proposed sensor also exhibited outstanding electroanalytical characteristics for glucose oxidation in these samples, including reusability, repeatability, and interference resistance, even in the presence of other biological substances and organic and inorganic metal ions.

Relationship of continuous glucose monitoring-related metrics with HbA1c and residual ß-cell function in Japanese patients with type 1 diabetes.

The targets for continuous glucose monitoring (CGM)-derived metrics were recently set; however, studies on CGM data over a long period with stable glycemic control are limited. We analyzed 194,279 CGM values obtained from 19 adult Japanese patients with type 1 diabetes. CGM data obtained during stable glycemic control over four months were analyzed. CGM-related metrics of different durations "within 120, 90, 60, 30, and 7 days" were calculated from baseline. Time in range (TIR; glucose 70-180 mg/dL), time above range (TAR; glucose ≥ 181 mg/dL), and average glucose levels, but not time below range (TBR; glucose ≤ 69 mg/dL), strongly correlated with glycated hemoglobin (HbA1c) values (P < 0.0001). TBR correlated with glucose coefficient of variation (CV) (P < 0.01). Fasting serum C-peptide levels negatively correlated with glucose CV (P < 0.01). HbA1c of approximately 7% corresponded to TIR of 74% and TAR of 20%. The shorter the CGM period, the weaker was the relationship between HbA1c and CGM-related metrics. TIR, TAR, and average glucose levels accurately reflected HbA1c values in Japanese patients with type 1 diabetes with stable glycemic control. Glucose CV and TBR complemented the limitation of HbA1c to detect glucose variability and hypoglycemia. Stable glycemic control with minimal hypoglycemia depended on residual ß-cell function.

2D metal azolate framework as nanozyme for amperometric detection of glucose at physiological pH and alkaline medium.

The synthesis of Co-based two-dimensional (2D) metal azolate framework nanosheets (MAF-5-CoII NS) is described using a simple hydrothermal method. The product was isostructural to MAF-5 (Zn). The as-prepared MAF-5-CoII NS exhibited high surface area (1155 m2/g), purity, and crystallinity. The MAF-5-CoII NS-modified screen-printed electrode (MAF-5-CoII NS/SPE) was used for nonenzymatic detection of glucose in diluted human blood plasma (BP) samples with phosphate buffer saline (PBS, pH 7.4) and NaOH (0.1 M, pH 13.0) solutions. The MAF-5-CoII NS nanozyme displayed good redox activity in both neutral and alkaline media with the formation of CoII/CoIII redox pair, which induced the catalytic oxidation of glucose. Under the optimized detection potential, the sensor presented a chronoamperometric current response for the oxidation of glucose with two wide concentration ranges in PBS-diluted (62.80 to 180 µM and 305 to 8055 µM) and NaOH-diluted (58.90 to 117.6 µM and 180 to 10,055 µM) BP samples, which were within the limit of blood glucose levels of diabetic patients before (4.4-7.2 mM) and after (10 mM) meals (recommended by the American Diabetes Association). The sensor has a limit of detection of ca. 0.25 and 0.05 µM, respectively, and maximum sensitivity of ca. 36.55 and 1361.65 mA/cm2/mM, respectively, in PBS- and NaOH-diluted BP samples. The sensor also displayed excellent stability in the neutral and alkaline media due to the existence of hydrophobic linkers (2-ethyl imidazole) in the MAF-5-CoII NS, good repeatability and reproducibility, and interference-free signals. Thus, MAF-5-CoII NS is a promising nanozyme for the development of the disposable type of sensor for glucose detection in human body fluids. Graphical abstract.

Postprandial Increase in Mesenteric Blood Flow is Attenuated in Parkinson's Disease: A Dynamic PC-MRI Study.

BACKGROUND: Gastrointestinal dysfunction and related clinical symptoms are common in Parkinson's disease (PD), but the underlying mechanisms are still poorly understood. OBJECTIVE: In this study, we investigated how PD affects the postprandial vascular response in the splanchnic circulation. METHODS: 23 patients with PD in the "ON-medication" state and 23 age- and sex-matched healthy control participants underwent serial phase-contrast magnetic resonance imaging (PC-MRI) to measure the postprandial blood flow response in the superior mesenteric artery (SMA). Participants ingested a standardized liquid test meal (∼400 kcal) and underwent four PC-MRI runs within the following hour. Each PC-MRI run consisted of six consecutive measurements of SMA blood flow. RESULTS: In both groups, standardized food intake triggered an increase of blood flow in the SMA, but absolute and relative increases in blood flow were attenuated in patients compared to the control group (p < 0.001). While baseline blood flow in the SMA was comparable in both groups, the postprandial maximum blood flow was attenuated in patients (p = 0.03). The temporal dynamics of the postprandial blood flow did not differ between groups. Postprandial SMA blood flow increase in patients correlated neither with subjective reports of non-motor symptoms or upper gastrointestinal complaints, nor with levodopa equivalent daily dose or disease duration. Blood glucose measurements in between the PC-MRI runs showed a smaller postprandial increase in blood glucose in the patient group (p = 0.006). CONCLUSION: This study provides first-time evidence that patients with PD have an attenuated postprandial blood flow response in the SMA, indicating an impaired functional regulation of gastrointestinal perfusion in response to food intake in PD.

Nickel sulfide nanoworm network architecture as a binder-free high-performance non-enzymatic glucose sensor.

Nickel sulfide nanoworm (Ni3S2 NW) network architecture was directly grown on the poly (3,4-ethylenedioxythiophene)-reduced graphene oxide hybrid films (PEDOT-rGO HFs) modified on glassy carbon electrode (GCE), acting as a binder-free sensor for high-performance non-enzymatic glucose monitoring. The sensor exhibited the satisfactory sensitivity (2123 µA mM-1 cm-2), wide linear range (15~9105 µM), low detection limit (0.48 µM), and rapid response time (< 1.5 s) at a potential of 0.5 V (vs. SCE) in 0.1 M NaOH and possessed good selectivity, reproducibility, and stability. The enhanced electrocatalytic activity of the sensor towards glucose oxidation was attributed to the particular morphology, satisfying hydrophilic nature, strong combination between Ni3S2 NWs, PEDOT-rGO, and bare GCE. Moreover, it can be used for assaying glucose in human serum samples without dilution, indicating potential for clinical diagnostic applications. Graphical abstract Nickel sulfide nanoworms (Ni3S2 NWs)/poly (3,4-ethylenedioxythiophene)-reduced graphene oxide hybrid films (PEDOT-rGO HFs) were used to construct a binder-free high-performance non-enzymatic glucose sensor with satisfactory sensitivity, wide linear range, low detection limit, good selectivity, amazing reproducibility, and stability.

Iron-Mineralization-Induced Mesoporous Metal-Organic Frameworks Enable High-Efficiency Synergistic Catalysis of Natural/Nanomimic Enzymes.

Metal-organic frameworks (MOFs) have become a promising accommodation for enzyme immobilization and protection. However, the integration of multienzymes into MOFs may result in compromise of individual enzymatic activity. In this work, we report an iron mineralization strategy to facilely construct a mesoporous MOF, possessing excellent peroxidase-mimic bioactivity. Furthermore, the feasibility of in situ encapsulating natural enzymes within the developed mesoporous MOF nanozymes endows these natural/nanomimic enzyme hybrids with remarkably enhanced synergistic catalysis ability. Such activity enhancement is mainly due to (1) the fast flux rate of substances through the interconnected mesoporous channels and (2) the simultaneously increased loading amount of enzymes and iron within the MOFs caused by the iron mineralization process.

Two-dimensional iron MOF nanosheet as a highly efficient nanozyme for glucose biosensing.

Two-dimensional (2D) nanomaterials are attractive in catalysis due to their rich accessible active sites. Iron-based metal organic frameworks (MOFs) are promising nanozymes because of their iron center and pore structure. However, it is challenging to obtain iron-based 2D MOF nanozymes due to the coordinated form of iron. Herein, we report a cation substitution strategy to transform an easily obtained Cu(HBTC)(H2O)3 (represented as Cu(HBTC)-1, the product of only two carboxylate groups in 1,3,5-benzenetricarboxylic acid (H3BTC) ligands linked by Cu ions) nanosheet into a 2D Fe-BTC nanosheet, which was characterized by SEM (scanning electron microscopy), AFM (atomic force microscopy), XPS (X-ray photoelectron spectroscopy), FT-IR (Fourier transform infrared spectroscopy), and XRD (X-ray diffraction). The 2D Fe-BTC nanosheet can catalyze TMB (3,3',5,5'-tetramethylbenzidine) oxidation by H2O2, showing its intrinsic peroxidase mimetic characteristic. The catalytic performance of 2D Fe-BTC was superior to those of its template Cu(HBTC)-1 nanosheet and 3D MIL-100(Fe). Their catalytic activities follow the order of 2D Fe-BTC > MIL-100(Fe) > 2D Cu(HBTC)-1. The peroxidase-like activity of 2D Fe-BTC is 77 times that of its template Cu(HBTC)-1, and 2.2 times that of MIL-100(Fe), a well known 3D crystalline form of iron trimesates. The Km values of 2D Fe-BTC for TMB and H2O2 were 0.2610 mM and 0.0334 mM, which were 1.6 and 1.9-fold lower than those of 3D MIL-100(Fe), respectively. The TMB oxidation rate and H2O2 reduction rate at unit mass concentration of the catalyst (Kw) for 2D Fe-BTC were 2.7-72.3 and 1.5-37.9 times those for the previously reported 3D MOF nanozymes, respectively. In terms of the excellent peroxidase mimetic characteristic of 2D Fe-BTC, a sensitive and selective colorimetric biosensing platform for hydrogen peroxide and glucose was developed. The linear ranges are 0.04-30 µM and 0.04-20 µM for H2O2 and glucose, with a low detection limit of 36 nM and 39 nM, respectively. The assay was satisfactorily applied to glucose determination in biological matrices.