Recovery Values Research Articles

Joint optimization of recyclable inventory routing problem under uncertainties in an incentive-based recycling system

Due to the value of resource recovery and the development of a circular economy, waste recycling has gathered global attention. Recently, many emerging cities designed new systems like an incentive-based recycling system (IBRS). In such systems, recyclables are collected through community recycling nodes by offering incentives, then transported to street recycling stations and sorted before being finally recycled. The increased recycling nodes and the incentives enhance the convenience and residents’ enthusiasm for waste recycling, but also intensify the uncertainty of recycling quantities and the complexity of the recycling operation management. Poor recycling operation management may result in increased recycling costs or greater loss of recyclables, which discourages residents from participating in recycling. Based on an existing IBRS, this study investigates the joint optimization problem of the recyclable inventory management at each community recycling node and the vehicle routing from the recycling nodes to the recycling station. A two-stage dual-objective multi-period stochastic programming model is established to minimize the loss of recyclables and logistics costs, which is further reformulated using the weighting method and transportation cost approximation parameters. To solve the reformulated model, a three-phase iterative algorithm is designed by combining the progressive hedging algorithm and route splitting algorithm based on the Lin-Kernighan heuristic. A case study is conducted using data from Shanghai’s IBRS. The proposed joint decision model is superior to separate decisions and the three-phase iterative algorithm can reduce the average total cost by up to 42.12% compared to the genetic algorithm and the Iteration-Move-Search method in the literature. Additionally, a sensitivity analysis is conducted to provide managerial insights.

Multi-enzyme-immobilized robust self-floating covalent organic framework/chitosan aerogels for the efficient remediation of emerging pollutants in water

Organic contaminants of emerging concern (OCECs) as a new class of organic pollutants have initiated intense global concerns. The efficient enzymatic water treatment was consider the crucial for the potential remediation process. However, the widespread application of enzymatic systems faces significant obstacles, including low enzyme activity and the lower value of recovery. Thus, a novel multi-enzymes immobilized biocatalytic system (multi-enzyme@COF@Chitosan aerogels) was synthesized via the combine the in-situ direct immobilization process and double-cross linking strategy in this study. Results showed that multi-enzyme@COF@Chitosan aerogels exhibits good mesoporous structure (the pore size distribution is 2.5nm) and mechanical strength, leading to remarkable stability a broader pH range (4-7) and temperature range (30~70 ℃). For typical OCECs, including 2-mercaptobenzothiazole (MBT), paracetamol (PCM), sulfamethoxazole (SMO), bisphenol A (BPA), Sulfamerazine (SMR), the remediation activities reached 100%, 87%, 68%, 69%, and 100%, respectively. Likewise, the multi-enzyme@COF@Chitosan aerogels exhibited good reusability, with the relative activity still maintained approximately 75.7% after seven cycles. Moreover, the electrochemical characteristics of multi-enzymes@COF@Chitosan aerogel and enzymes activities were contributed to degradation the OCECs.

TiO2 intercalated MWCNTs nanocomposite sensor for the detection and quantification of 5-Fluorouracil

The present analysis deals with the fabrication of novel electrochemical sensing platforms for the determination of the anti-cancer drug 5-Fluorouracil (5-FLU). Multiwalled carbon nanotubes/titanium dioxide nanoparticles (TiO2·MWCNTs) modified carbon paste electrodes were constructed and used to quantify 5-FLU in pH 7.0. TiO2·MWCNTs nanocomposite reveals a non-uniform distribution of agglomerated TiO2 nanoparticles over the smooth surface of MWCNTs At the TiO2∙MWCNTs/CPE, the 5-FLU molecule underwent an irreversible electro-oxidation process. The proposed electrode platform exhibited a high catalytic effect for the 5-FLU. The TiO2∙MWCNTs/CPE sensor shows the detection limits of 2.7nM for 5-FLU with sensitivity of 82.15µA·µM−1·cm−2. The sensor was employed to detect the desired drug moiety in the urine samples of pharmaceutical drugs along with spiked water and soil samples; the good recovery values demonstrating the applicability and selectivity of the sensor were supported by excipient interference investigation. Thus, the developed sensors and method makes them a promising alternative for future research to determine other bio-active molecules in pharmaceutical and clinical samples.

Starch-modified nickel ferrite nanoparticles as a magnetic nano-bio adsorbent for the extraction and determination of lead in water and Moringa oleifera samples

In this work, nickel ferrite magnetic nanoparticles were synthesized using a facile hydrothermal method. The surface modification of the prepared nanoparticles was carried out using cross-linked starch as a good stabilizer and biopolymer. The as-prepared nickel ferrite-starch nano-bio composite was characterized using numerous techniques, and introduced as a novel adsorbent. The initial experimental results indicated that the adsorbent has a good capability to extract lead ions (Pb(II)) from aqueous solutions. Hence, the adsorbent was applied for dispersive magnetic solid-phase extraction of Pb(II) before flame atomic absorption spectrometric detection. Some variables affecting the extraction efficiency such as sample volume (250.0mL), pH (6.5), type and eluent concentration (0.3molL1 nitric acid), amount of the adsorbent (200mg), extraction time (15min), and desorption time (15min) were investigated and optimized. Moreover, the adsorption capacity (35.50mgg1), stability and reusability (80 extraction/desorption cycles), and selectivity of the adsorbent towards the analyte were studied. In the optimized conditions, the linear dynamic range of the constructed calibration graph is between 0.5 and 140.0ngmL1. The limit of detection and limit of quantification of the method are 0.12 and 0.40ngmL1, respectively. The average intra-day and inter-day relative standard deviations (for n=6 and 5.0, 50.0 and 100.0ngmL1 Pb(II) concentration) are 2.02% and 3.72%, respectively. To validate the method, the certified reference material NIST SRM 1643e was analyzed, and the method was used for the pre-concentration and determination of lead ions in different sections of Moringa oleifera medicinal plant and several water samples. The acceptable relative recovery values between 98.0 and 102.7% were attained for the spiked samples, approving the ignorable matrix effect of the method.

Climate Response and Radial Growth Dynamics of Pedunculate Oak (Quercus robur L.) Plus Trees and Their Half-Sib Progeny in Periods of Severe Droughts in the Forest-Steppe Zone of Eastern Europe

The dendrochronological parameters of 97 pedunculate oak (Quercus robur L.) trees including 20 plus trees (142-year-old on average) and four half-sib families for four of them were analyzed considering also specifically years of the most severe droughts that were identified using average monthly air temperature and precipitation data. The tree-ring width (TRW) was mostly affected by air temperature that had the largest cross-dating indices (CDI), up to 78% maximum. However, the 32-year Brückner–Egeson–Lockyer cycle (a climatic cycle of approximately 30–40 years that correlates with sunspot activity) was more reflected in the TRW dynamics in plus trees than precipitation and air temperature. A high-frequency of abnormal TRW was clearly observed during drought periods and in the following 2–3 years. Tree radial-growth reduction due to drought stress varied significantly between families. The resistance to drought based on TRW was higher in the maternal plus oak trees than in progeny. Drought resulted in reduced growth during the subsequent year(s); hence, the minimum growth occurred after the actual climate event. Autumn–winter precipitation and weather conditions were of the greatest importance at the onset of active vegetation in April and May. The influence of air temperature on oak growth was the largest in March (r = 0.39, p < 0.05). The strongest positive correlation between precipitation and growth (with r up to 0.38) was observed in May 2023. Plus trees had a high adaptive potential due to the stability of radial growth during drought with high resistance (Rt = 1.29) and resilience (Rs = 1.09) indexes. The offspring of families 1 (Rt = 0.89, Rs = 0.89) and 2 (Rt = 1.04, Rs = 0.87) had similar resistance and resilience, but the recovery indices (Rc) for offspring in families 1, 2 and 3 exceeded the recovery values for plus trees. For offspring in families 3 and 4, the index values were lower. The revealed responses of wood growth of plus trees to climatic parameters estimated as resistance (Rt), resilience (Rs) and recovery (Rc) indexes and similar responses in their progeny can be used in breeding pedunculate oak for wood growth productivity and drought resistance.

Microfluidic sensor using pH gradient with hybrid magnetoliposomes containing laccase immobilized nanocrystals.

A method using pH gradient to modify the phospholipid dissociation has been developed using hybrid magnetoliposomes with encapsulated enzyme laccase, which has been immobilized on hydrophilic magnetic nanocrystals (PAA-MNCs) retained in the reaction/detection zone of a microfluidic system. The hybrid magnetoliposomes act as micro containers, providing the safe transfer of the enzyme to the reaction/detection site, where it is retained, and preconcentration of the enzyme in this placeoccurs, which improves the system's sensitivity. The use of pH change involves the lack of external molecules to release the encapsulated materials. The laccase-mediated redox oxidation of the fluorescent substrate 8-hydroxypyrene-1,3,6-trisulfonic acid (HPTS) to form its non-fluorescent oxide form has been used as the indicator reaction. The method was applied to determine potential laccase inhibitors in beverages and fruits. The study of the inhibitory effect has focused on compounds that follow different mechanisms: cysteine, malic acid, and fumaric acid. The dynamic ranges of the calibration graphsof these compoundswere between 0.05-100, 0.02-100, and 0.1-100μmol L-1, respectively. The detection limits have been established between 6 and 30nmol L-1, and the precision expressed as the percent of relative standard deviation (RSD%) was between 2.5 and 5.1%. The overall microfluidic system showed a sampling frequency of 8h-1. The method has been applied to determine fumaric acid as a laccase inhibitor in several juice samples (apple, pear, and grape), with recovery values between 85 and 101%. The results were comparable to those obtained using a LC reference method.

Positive Predictive Value of Contrast-Enhanced Fluid-Attenuated Inversion Recovery (FLAIR) Magnetic Resonance Imaging in Diagnosis of Meningitis Among Pediatrics Taking Cerebrospinal Fluid Analysis as Gold Standard

Positive Predictive Value of Contrast-Enhanced Fluid-Attenuated Inversion Recovery (FLAIR) Magnetic Resonance Imaging in Diagnosis of Meningitis Among Pediatrics Taking Cerebrospinal Fluid Analysis as Gold Standard

Voltammetric Determination of Pyridoxine in Pharmaceutical Samples Using Phosphorus-Doped Copper Oxide Pencil Graphite Electrode

Abstract A phosphorus-doped copper oxide/pencil graphite electrode (P-doped CuO/PGE) was developed to determine pyridoxine selectively. The phosphorus doped into the copper has revealed a large number of defects that can provide active sites for the reaction to take place, thus contributing to the improvement of the electrical conductivity of copper oxide. Cyclic voltammetry, electrochemical impedance spectroscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were employed for the characterization of the P-doped CuO/PGE. Surface morphology was analyzed by field emission scanning electron microscopy. Electrochemical measurements were performed by differential pulse voltammetry, and the limit of detection (LOD) and limit of quantification values for pyridoxine were calculated. The LOD value was 0.33 μmol L-1 with a linear range of 1.0 and 100 μmol L-1. The developed sensor showed a remarkable anti-interference effect against interference from ascorbic acid, dopamine, glucose, uric acid, and lactate. Potential interference effects of species that may coexist with pyridoxine in pharmacological samples were also investigated. The applicability of the developed sensor to real samples was examined, and satisfactory recovery values were obtained.

Effect of various culinary treatments on the glycoalkaloid content of potato peel

Potatoes are one of the most consumed foods worldwide. During germination, glycoalkaloids (GAs) with potential bioactive properties are produced, which, at high concentrations, may have adverse health effects. Potato peels, a byproduct generated in large quantities but increasingly used in contemporary cuisine, contain significant levels of these GAs. This paper examines GA levels in potato peels after various culinary treatments (boiling, steaming, baking, air frying, conventional deep frying, and double frying) to provide new data and ensure food safety. An optimized extraction method using ultrasound-assisted extraction (UAE) was employed, followed by purification with mesostructured SBA-15 silica functionalized with octadecylsilane (C18) chains as sorbent in solid-phase extraction, prior to HPLC-DAD determination of α-solanine and α-chaconine levels in the samples. The method was validated, obtaining excellent recovery values (88 – 96 %) and low detection and quantification limits (0.3 and 1 mg/L, respectively). Upon application of the validated analytical method to the samples culinarily treated using the most common cooking techniques (boiling, steaming, baking, air frying, conventional deep frying, and double frying) at various times and temperatures, the obtained results demonstrated significant reductions (between 52 % and 84 %) in GAs content in the treated potato peels, compared to fresh samples. Statically significant degradation of these compounds was observed through baking at elevated times and temperatures (74 – 84 %), as well as both conventional deep frying and double frying (76 – 83 %).

Detection of the antipsychotic drug cariprazine using a low-cost MIP-based electrochemical sensor and its electrooxidation behaviour

Cariprazine (CAR), a member of the class of atypical antipsychotics, is a widely utilized pharmaceutical agent. Therefore, analytical techniques for its detection in real samples must be established, both for the purposes of treatment and for the advancement of the pharmaceutical industry. In recent years, there have been notable advancements in the development of sensor-based technologies, particularly those employing electrochemical detection for the rapid and precise analysis of a range of pharmaceuticals. Accordingly, the present study initially examined the voltammetric behaviour of CAR using an unmodified glassy carbon electrode (GCE). The mechanism of electrochemical oxidation was proposed, and subsequently, an electrochemical method for the determination of CAR was applied, which demonstrated a detection limit of 6.4 × 10−7 M (0.64 µM) and a broad linear dynamic range (2.5 × 10−6–5.0 × 10−5 M; 2.5–50.0 µM). Subsequently, a molecularly imprinted recognition system was fabricated via a simple one-step electrochemical polymerization process, using CAR as the template molecule and 3-aminophenylboronic acid as the functional monomer. A systematic optimization of the parameters influencing the sensor response was conducted. Upon identifying the optimal conditions, the MIP/GCE demonstrated a commendable sensitivity (177.25 µA/µM) and a detection limit of 1.27 × 10−14 M (12.7 fM) in a linear range from 1.0 × 10−13 to 2.5 × 10−12 M (0.1–2.5 pM). Subsequently, the sensor was effectively utilized to determine CAR in capsule and commercial serum samples, yielding satisfactory recovery values.

Synthesis of Functionalized Pyridine Modified Magnetic Nanoparticles for Utilization in Magnetic Solid-Phase Extraction of Tebuconazole and Propiconazole Followed by Quantification via High-Performance Liquid Chromatography-Ultraviolet Detection.

In the current study, a new magnetic sorbent (Fe3O4@2,6-diamino-4-(3,4-dihydroxyphenyl) pyridine-3,5-dicarbonitrile) was prepared as a new and efficient sorbent to be used in the magnetic solid-phase extraction method to extract tebuconazole and propiconazole as model compounds. In this regard, effective parameters such as pH of the sample solution, desorption volume, ionic strength, extraction time, desorption time, and amount of the magnetic sorbent were optimized using experimental design. In the optimal condition, the linear dynamic ranges for tebuconazole and propiconazole were between 0.5 and 200.0µg/L. Also, the limits of detection, limits of quantification, and relative standard deviations were 0.21-0.14µg/L, 0.49-0.45µg/L, and 1.3%-4.6%, respectively. The estimated enrichment factors for tebuconazole and propiconazole were 22 and 28, respectively. The absolute recovery (AR%) values for tebuconazole and propiconazole were also 67% and 84%, respectively. Finally, the proposed method was used for determination of tebuconazole and propiconazole in cucumber, tomato, orange, and lemon fruits. The obtained result confirmed that the presented method is capable for the analysis of the selected analytes in complicated matrices. In addition, the ARs% were in the range of 67%-84%. The result proved that the presented method can be an alternative to the extraction process of various pesticides.

In-situ grown hexagonal rod-like ZIF-L(Zn/Co) variant on reduced graphene oxide (rGO) for the enhanced electrochemical sensing of acetaminophen

Graphene – one of the most regarded materials in the world of Flatland has a substantial role in sensing applications due to its exceptional properties. Combining graphene with MOF can effectively mitigate the limitations of MOF while synergistically enhancing their unique properties. In this research work, we present a new hybrid composite of Zeolite Imidazolate Framework-L made composite with reduced graphene oxide, ZIF-L(Zn/Co)/rGO (ZLG) and applied its electrocatalytic performance in the sensitive detection of acetaminophen (AP). The mixture was prepared via a simple in-situ solvothermal method whose physico-chemical nature was investigated in detail. The ZIF-L phase identification, morphological change of ZIF, confirmation of rGO incorporation, and chemical composition analysis were established using the XRD, SEM, Raman and XPS respectively. Additionally, the kinetics of electron transfer was studied by EIS. Thereafter, proper optimization of various sensor parameters such as pH, scan rate and analytical performance were executed. Preliminary sensing studies carried out by cyclic voltammetry revealed an enhancement in peak current from 0.48µA to 1.05µA upon incorporation of rGO into the ZIF-L(Zn/Co) hybrid. Compared with reported studies along a similar vein, from the differential voltammetric analysis the ZLG-modified GCE displays a high selectivity towards AP with a broad linear range of 1 µM – 2060 µM exhibiting a sensitivity and LOD of 8.145 µA/mM and 162 nM respectively. The real-time validation of the sensor in paracetamol tablets and biological samples of human blood and urine exhibited recovery values in the range of ∼ 94 % − 102 %. Hence, this suggests a reliable practical applicability of the sensor owing to the high catalytic, large surface area and increased conductivity of the nanocomposite.

Rapid and sensitive colorimetric assay based on aggregation of gold nanoparticles coupled with fuzzy inference system for the trace determination of sofosbuvir and ledipasvir as anti-hepatitis F in binary mixture

A facile, rapid, low-cost, and sensitive gold nanoparticle (AuNP)-based colorimetric method was introduced to analyze sofosbuvir (SOF) and ledipasvir (LED) simultaneously in laboratory binary mixtures and pharmaceutical formulation samples using fuzzy inference system (FIS). The synthesized AuNPs before and after adding the drug were characterized using Fourier-transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), and dynamic light scattering (DLS). After adding the drug to AuNPs solution, the color change from wine red (520 nm) to grey (660 nm) occurred due to the aggregation of AuNPs and the surface plasmon resonance (SPR) in the visible region. A linear calibration curve was in the range from 10 to 100 and 20–100 mg/L with a limit of detection and limit of quantification of 9.57, 29.07 μg/L and 8.58, 26.15 μg/L for SOF and LED, respectively. FIS along with principal component analysis (PCA) was used for the simultaneous determination of SOF and LED. The mean recovery values were found to be 101.07 % and 99.58 %, and the root mean square error (RMSE) was 1.1455 and 1.2138 for SOF and LED, respectively. The results obtained from the analysis of real sample by FIS-PCA and HPLC were compared via an ANOVA test and no significant difference was observed. The results indicated that the developed optical method has high precision, accuracy, and sensitivity for the analysis of pharmaceutical components in binary mixtures, which can be faster and less expensive than chromatography methods.

A New Modified Carbon Paste Electrode for Selective Determination of Chromium(III) in Pharmaceutical Drugs and Food Samples

Background and Objective: This study presents a novel potentiometric method for the precise, accurate, selective, and rapid determination of Cr(III) ion concentration in different samples. Methods: A new ionophore, namely macrocyclic tetramide ionophore (MCTA), was synthesized through an inexpensive and straightforward approach, yielding a high-quality product. The (MCTA) ionophore was utilized as the active center in the preparation of modified carbon paste electrodes (MCPEs) to quantify the Cr(III) ion. The paste was made by adding graphite, MCTA, and plasticizer and mixing them in varying weight percent ratios. Results: The proposed electrodes, I and II, exhibited a trivalent Nernstian response of 20.029 ±0.57 and 20.3±0.56 mV decade-1 , respectively, with linearity of 1.0x10-7 – 1.0x10-2 and 1.0x10-5 – 1.0x10- 2 mol L-1 . Electrodes I and II were examined for their pH, response time, and thermal stability. In comparison to other mono-, bi-, and trivalent cations, starch, and sugars, the electrodes demonstrated a high degree of selectivity for Cr(III). The modified electrodes were used to determine the concentration of Cr(III) in various real samples, including drug tablets, juice extractions, and tap water, with acceptable recovery values. Conclusion: The results were compared with those obtained using the previously reported method, with no significant difference observed between them, as indicated by the F and t-test values. The data showed good accuracy and precision, as well as a high percentage of recovery. The adsorption capacity of the MCTA ionophore towards Cr(III) ions was also examined.

Development and Validation of an optimized HPLC-UV analytical method for the quantification of 5-Methyltetrahydrofolate (Active Folate) in dietary Supplements: Application to commercial tablets and capsules

5-MTHF is the active form of folic acid, and it is provided as a dietary supplement in the market. Therefore, in this study we provide a new, simple and economic HPLC-UV analysis method to quantify 5-MTHF in dietary supplement. A new HPLC-UV method was developed and validated for the quantification of 5-methyltetrahydrofolate in dietary supplements. The method was optimized in terms of chromatographic conditions, including the mobile phase composition, chromatographic column, and the sample preparation diluent using ascorbic acid. A combination of ammonium acetate buffer with methanol (90:10) was the optimal mobile phase, achieving a retention time of approximately 11.4 min on C18 column with good column performance (N = 6786, Asymmetry = 1.03). The method was validated for selectivity, linearity, precision, accuracy, and robustness. The calibration curve was linear (r2 > 0.999) over the concentration range of 1.20 to 4.80 µg/mL. Precision was demonstrated with RSD% values ranging from 1.38 % to 2.90 % for intra-day precision and 0.96 % to 2.61 % for inter-day precision. Accuracy was confirmed with recovery values between 96.5 % and 110.6 % for spiked samples. To demonstrate the method’s applicability, ten brands of 5-MTHF dietary supplements were collected from local pharmacies. Assay results showed significant variability, with four brands having contents below the acceptable range (90–110 % of labeled contents) and two brands exceeding this range. The stability of 5-MTHF in these products appeared to be formula-dependent, emphasizing the need for regulatory revisions to mandate stability testing for dietary supplements.

A new method development and validation for simultaneous estimation of ramipril and telmisartan by RP-HPLC method in combined dosage form

The present research work was development and validation of new RP-HPLC method for simultaneous estimation of Ramipril and Telmisartan in combined dosage form. In simultaneous RP-HPLC method development, Waters 2695 Separations Module with PDA Detector and column used is C8 SB ZORBAX (150 X 4.6mm) column with 3.5-micron particle size. Injection volume of 10 µL is injected and eluted with the mobile phase selected after optimization was Phosphate buffer and Acetonitrile in the ratio of 70:30 was found to be ideal. The optimized flow rate was at 1.0 mL/min. Detection was carried out at 230 nm. This system produced symmetric peak shape, good resolution and reasonable retention times of Ramipril and Telmisartan were found to be 2.275 and 4.261 minutes respectively. The Ramipril and Telmisartan showed linearity in the range of 20-60 µg/mL and 160-480 µg/mL respectively. The %RSD values for precision was found to be within the acceptable limit, which revealed that the developed method was precise. The developed method was found to be robust and the %RSD value for percentage recovery of Ramipril and Telmisartan was found to be within the acceptance criteria. The results indicate satisfactory accuracy of method for simultaneous estimation of the Ramipril and Telmisartan.

Foam separation of radio-molybdenum oxyanions (99MoO42−) incorporated into Co(II)/Al(III) layered double hydroxide using anionic surfactant

Foam separation of radio-molybdenum oxyanions (99MoO42−) incorporated into in-situ formed Co(II)/Al(III) layered double hydroxide (LDH) particles was applied for recovery of these anionic species from aqueous solutions. The results showed that Co(II)/Al(III) molar ratios of 2 and 2.5 resulted into not only high recovery values for 99MoO42− (R > 0.97), but also high decontamination factor (DF = 33 and 36, respectively). Almost complete recovery was achieved for 99MoO42− coprecipitated with Co(II)/Al(III) LDH in the pH range 9.9–10.5. Ageing time of 5 min was sufficient to completely coprecipitate the concerned anionic species. Sodium dodecyl sulfate (SDS) concentrations in the range 1.5 × 10−3 - 3 × 10−3 mol/L had the ability to efficiently form hydrophobic 99MoO42--Co(II)/Al(III)-LDH particles, where recovery values of about 0.96 were achieved with high DF values. The influence of the coexistence of different foreign anions (Cl−, NO3−, HCO3−, CO32− and SO42−) during coprecipitation process of 99MoO42− and foam separation of the resultant particles was investigated. The suggested strategy in the present study was effectively applied for recovery of 99MoO42− anions from ground water (R ≈ 0.98 and enrichment ratio (ER ≈ 7172) and radioactive process wastewater (R ≈ 0.96 and ER = 3887). Based on characterization of Co(II)/Al(III) LDH using Fourier transform infrared (FTIR) and X-ray diffraction (XRD) before and after foam separation process using SDS and the obtained data, the recovery mechanism of 99MoO42− was proposed.

Long-term prognostic value of heart rate recovery in patients with left bundle branch block without inducible ischemia and without known coronary artery disease

Abstract Background Heart rate recovery (HRR) has been shown to predict cardiovascular and all-­cause morbidity and mortality. Left bundle branch block (LBBB) is often associated with significant heart disease and is often the result of underlying coronary artery disease (CAD), myocardial injury, strain or hypertrophy. However, there are insufficient data on the prognostic value of HRR in patients with LBBB without inducible ischemia and without known CAD. Aim The aim of this study was to determine the long-term prognostic value of HRR in patients with LBBB without inducible ischemia and without known CAD. Methods This retrospective study included 182 patients (64, 35.2% male gender, average age 63 ± 10 years) with LBBB and without known CAD who were referred to the SECHO test for chest pain. All the patients had negative SECHO test according the Bruce protocol. Risk factors for CAD (diabetes, smoking, hypertension, high cholesterol and positive family history of CAD), functional capacity (Metabolic Equivalents - METs) and heart rate recovery (HRR) were recorded in all patients. HRR was calculated as the difference between heart rate at the peak stress and heart rate in the first minute of rest. Slow HRR was defined as ≤18 beats/min. Median follow up of the patients was 102.5 months (IQR 68-146 months) for the occurrence of MACE (all-cause mortality, non-fatal myocardial infarction (MI), coronary artery bypass grafting (CABG) and percutaneous coronary intervention (PCI)). Results Overall, 16pts (8.8%) had slow HRR. During the follow-up period 34 out of 182 patients (18.7%) had an adverse event (16 deaths, 10 non-fatal MI, 1 CABG and 7 PCI). Using the Cox regression analysis, univariate predictors of MACE were age (B=0.050, HR 1.051 [95% CI 1.011-1.093], p=0.012), hypertension (B=-1.219, HR 3.385 [95% CI 1.071-10.699], p=0.038), MET (B=-0.183, HR 0.833 [95% CI 0.706-0.982], p=0.030), diabetes (B=0.981, HR 2.667 [95% CI 1.267-5.612], p=0.010) and slow HRR (B=1.171, HR 3.225 [95% CI 1.307-7.959], p=0.011). However, in the multivariate analysis only slow HRR remained the independent predictor of MACE (B=0.974, HR 2.648 [95% CI 0.980-7.151], p=0.048). Using the Kaplan-Meier survival curve we see that the patients with slow HRR had much shorter event-free time compared to the patients with normal HRR (106.9 ± 14.9 months vs 157.9 ± 24 months, Log Rank 7.227, p=0.007) (Figure 1.). Conclusion Slow HRR is an independent long-term predictor of adverse events in patients with left bundle branch block without inducible ischemia and without known coronary artery disease.Kaplan-Meier survival curve for the MACE

Heart rate response and recovery in bicycle exercise testing - reference values and association with mortality

Abstract Introduction Chronotropic incompetence and impaired heart rate (HR) recovery are related to mortality. Guidelines lack specific recommendations for reference values on HR recovery assessment. Purpose To define normal values for HR response and recovery in individuals referred for a bicycle exercise stress test and to relate these factors to risk of mortality. Methods We included 9,917 subjects (46% females) aged 18–85 years who performed a bicycle exercise test. We defined age- and sex-specific reference equations for peak HR, HR reserve, and HR recovery at 1 and 2 minutes (HRR1 and HRR2) using a subgroup of individuals without apparent cardiovascular (CV) risk nor comorbidities (N=2,774). Associations between blunted HR indices (<5thpercentile) and mortality were analysed using Cox regression in all subjects and in individuals with normal exercise capacity (N=8,070). Results All HR indices were age-dependent. The 5th percentiles of HR reserve, HRR1, and HRR2 correlated weakly with previously reported reference values. During median follow-up of 8.6 years 1,110 (11%) died. HR recovery variables were the strongest predictors of all-cause (HRR1, hazard ratio 1.66 (95% confidence interval, 1.45–1.90)) and CV mortality (HRR2, 1.59 (1.26–2.00)) after adjustments for potential confounders. Blunted HR response (peak HR) increased risk of all-cause (1.32 (1.14–1.53)) and CV mortality (1.41 (1.09–1.83)). Combined blunted HRR1 and HRR2 or HR response and HRR1 further increased risk of all-cause (1.92 (1.64–2.24) and 1.85 (1.55–2.22), respectively) and CV mortality (1.95 (1.50–2.54) and 1.94 (1.42–2.65), respectively). HR recovery variables (HRR1, 1.97 (1.63–2.39) and HRR2, 1.76 (1.46–2.12)) remained stronger predictors of mortality than peak HR (1.38 (1.10–1.72)) in individuals with normal exercise capacity. Conclusions All HR variables were age-dependent and associated with mortality. Blunted HR recovery was more strongly related to mortality than chronotropic incompetence, and their combination added prognostic value. Furthermore, blunted HR recovery variables, rather than blunted HR response, remained strongly associated with mortality even in the presence of normal exercise capacity.

Validation of a smartphone-compatible MIP-based sensor for bisphenol A determination in wastewater samples.

A handheld smartphone-compatible molecularly imprinted polymer (MIP)-based sensor was developed for the analysis of bisphenol A (BPA) in wastewater samples. Sensing elements based on ethylene glycol methacrylate phosphate (EGMP)-containing MIP films were designed and optimized using molecular dynamics simulations. The highly porous MIP films were synthesized via in situ polymerization, employing a fragment-based approach. The colorimetric response was based on the 4-aminoantipyrine method, while the MIP films were further utilized to detect BPA with a smartphone. The proposed sensor exhibited a wide linear range from 5 to 250μM, with a limit of detection (LOD) of 5μM (S/N = 3). Furthermore, the designed analytical system demonstrated excellent analytical performance in terms of selectivity, stability, and reproducibility. During sensor validation, real wastewater samples were successfully tested for BPA, showcasing the feasibility of the smartphone-compatible MIP-based sensor. Recovery values of 87.1-114.6% underscored the efficacy and reliability of the developed sensor system.