Average Recovery Rate Research Articles

Oleo-extraction of microplastics using flotation plus sol-gel technique to confine small particles in silicon dioxide gel.

Extracting microplastics from natural sources is challenging, especially microplastics with sizes smaller than 100μm. The flotation method is the most common microplastic extraction, but it struggles with fine particles due to the difficulty in collecting floating plastic particles from the liquid during the separation process. This study proposes a new floating media, tetraethyl orthosilicate (TEOS), that could separate microplastics using its hydrophobic-oleophilic properties. Most interestingly, TEOS transformed from a liquid state to a solid state (gel) by hydrolysis and condensation reactions, thus safely capturing the separated microplastic particles after flotation and mitigating particle loss from scooping since its gel acted as a particle holder. The average recovery rates obtained were in the range of 95-100% for polyethylene terephthalate, polyethylene, polypropylene, polyvinyl chloride, polystyrene, polytetrafluoroethylene, and aged tyre rubber. The recovery rates were slightly reduced for finer particles (sizes down to 40μm) at 82-98%. TEOS-based extraction provided a higher recovery rate for non-polar plastics than for polar or hydrophilic plastics. The separated microplastics maintained their characteristics for polymer identification, as proven by spectroscopic and thermal analysis techniques. Therefore, TEOS-based extraction could be a new approach to microplastic extraction, especially for preventing fine particle loss.

Determination of multiple restricted and prohibited ingredients in hair dyes using a novel 3D stationary phase coupled with gas chromatography-mass spectrometry

Hair dyes (HDs) are mainly composed of various benzene series, amines, and phenolic compounds. These ingredients are well known to have allergenic, teratogenic, and carcinogenic properties. As such, the presence of these ingredients in HDs has received increased attention in recent years. At present, the applications of traditional analytical and detection methods and commercial chromatographic columns are limited by problems such as poor qualitative analysis and inaccurate quantification. Thus, the development of new analytical and detection technologies and stationary phases is an urgent endeavor. Moreover, HDs contain complex compounds and exhibit significant matrix interference. Hence, appropriate sample pretreatment methods are necessary to analyze HDs. In this study, the 3D nonpolar rigid structure of triptycene (TP) was combined with the polar flexible chains of polyethylene glycol (PEG) to design and synthesize a TP derivative, TP-PEG, as a stationary phase for chromatographic columns. The stationary phase enabled the expansion of the selection range for polar and nonpolar analytes. Subsequently, gas chromatography-mass spectrometry (GC-MS) was used to quantitatively analyze 22 ingredients in HDs. The experimental results demonstrated that analytes with different polarities exhibited sharp and symmetrical peak shapes on the stationary phase, and all 22 analytes achieved baseline separation on the chromatographic column. The 22 ingredients in HDs showed good linear relationships within their respective ranges, with correlation coefficients greater than 0.9985. The average recovery rates at three spiked levels were in the range of 89.2%-103.2%, and RSDs were less than 5%. Compared with traditional methods, the proposed method has higher efficiency and better accuracy, thus verifying the excellent separation performance of the new stationary phase and the effectiveness of the established GC-MS detection method. The findings indicated the applicability of the developed method to the detection and analysis of various compounds in HDs.

Decline in and recovery of fertility rates after COVID-19-related state of emergency in Japan

IntroductionThe COVID-19 pandemic led to a decline in fertility rates worldwide. Although many regions have experienced a temporary drop in fertility rates with the spread of the infection, subsequent recovery...

Expanding sample volume for microscopical detection of nanoplastics

The extent of nanoplastic pollution has raised severe environmental and health concerns. While the means for microplastic detection are abundant, improved tools for nanoplastic detection are called-for. State-of-the-art microscopic techniques can detect nanoplastics down to tens of nanometers, however, only from small sample sizes (typically ∼10μl). In this work, we describe a method that enables sampling of 1 liter of seawater by the means of correlative Raman- and SEM-techniques. This is achieved by adapting common microplastic sample purification protocols to suit the nanoplastic study. In addition, we decorate a membrane filter with SERS-property to amplify the Raman signals. Together, the purification method combined with the use of the SERS-activated-membrane-filter enables identification and imaging of individual nanoplastic particles from significantly larger sample sizes than before. In the nanoscale the average recovery rate is 5 %. These results aim to provide useful tools for researchers in the fight against plastic pollution.

Highly effective strategy for isolation of mononuclear cells from frozen cord blood

Background aimsCord blood mononuclear cells (CBMCs) comprise a variety of single-nucleated cells found in the cord blood, mainly consisting of monocytes and lymphocytes. They also include a smaller proportion of other cell types, such as hematopoietic stem and progenitor cells (HSPCs) and mesenchymal stromal cells (MSCs). CBMCs are vital for acquiring HSPCs, MSCs, and other immune cells, like natural killer cells. These cells are essential for supporting subsequent research and clinical applications. Although automated equipment for CBMC enrichment has shown promise, the high cost of these machines and the expense of disposable consumables limit their routine use. Furthermore, limited information is available on manual strategies for isolating CBMCs from cryopreserved cord blood. Therefore, we aimed to optimize the dilution buffer and refine the isolation procedure for CBMCs. MethodsWe enhanced the CBMC recovery rate from cryopreserved cord blood using an optimized dilution buffer and a modified isolation procedure. ResultsWe achieved average recovery rates of 42.4 % and 54.3 % for CBMCs and CD34+ cells, respectively. Notably, all reagents used in the isolation procedure were of GMP-grade or pharmaceutical preparations, underscoring the potential clinical benefits of our strategy. DiscussionWe devised an optimized protocol suitable for routine research and clinical applications for enhanced recovery of CBMCs from cryopreserved cord blood units using an optimized dilution buffer and a modified isolation procedure.

Development of an Enhanced Quick, Easy, Cheap, Effective, Rugged, and Safe Method for Determination of Quinolone Drug Residues in Quail Eggs

ABSTRACTAn enhanced quick, easy, cheap, effective, rugged, and safe (QuEChERS) purification method utilizing multi‐walled carbon nanotubes (MWCNTs) has been developed and coupled with liquid chromatography‐tandem mass spectrometry for the determination of eight quinolone drug residues in quail eggs. The sample was extracted using ethylenediamine tetraacetic acid‐McIlvaine buffer (pH = 4.0) and 2% formic acid in acetonitrile, followed by salting out with MgSO4, and purification with primary secondary amine (PSA), MWCNT, and Octadecylsilane (C18). The method demonstrated linear relationships for the target compounds within the range of 2–100 µg/L with correlation coefficients (r) exceeding 0.99. The limits of detection and quantification were determined to be 0.4 and 0.8 µg/kg, respectively. Validation through a three‐level spiking test (low, medium, and high) in quail eggs resulted in an average recovery rate ranging from 86.8% to 113.7%, with relative standard deviations between 2.6% and 10.2% (n = 6). This method offers rapid operation, excellent purification efficiency, and high sensitivity, making it suitable for the qualitative and quantitative analysis of quinolone drug residues in eggs. Application of this method to a batch of 20 quail eggs revealed the presence of enrofloxacin and ciprofloxacin, suggesting a potential risk of non‐compliant quinolones use in quail egg production.

Detection of Short-Chain Chlorinated Aliphatic Hydrocarbons through an Engineered Biosensor with Tailored Ligand Specificity.

Short-chain chlorinated aliphatic hydrocarbons (SCAHs), commonly used as industrial reagents and solvents, pose a significant threat to ecosystems and human health as they infiltrate aquatic environments due to extensive usage and accidental spills. Whole-cell biosensors have emerged as cost-effective, rapid, and real-time analytical tools for environmental monitoring and remediation. While the broad ligand specificity of transcriptional factors (TFs) often prohibits the application of such biosensors. Herein, we exploited a semirational transition ligand approach in conjunction with a positive/negative fluorescence-activated cell sorting (FACS) strategy to develop a biosensor based on the TF AlkS, which is highly specific for SCAHs. Furthermore, through promoter-directed evolution, the performance of the biosensor was further enhanced. Mutation in the -10 region of constitutive promoter PalkS resulted in reduced AlkS leakage expression, while mutation in the -10 region of inducible promoter PalkB increased its accessibility to the AlkS-SCAHs complex. This led to an 89% reduction in background fluorescence leakage of the optimized biosensor, M2-463, further enhancing its response to SCAHs. The optimized biosensor was highly sensitive and exhibited a broader dynamic response range with a 150-fold increase in fluorescence output after 1 h of induction. The detection limit (LOD) reached 0.03 ppm, and the average recovery rate of SCAHs in actual water samples ranged from 95.87 to 101.20%. The accuracy and precision of the proposed biosensor were validated using gas chromatography-mass spectrometry (GC-MS), demonstrating the promising application for SCAH detection in an actual environment sample.

Simultaneous determination of 13 biogenic amines and their metabolites in liquid fermented food by HPLC-QTRAP-MS without derivatization

Biogenic amines and their metabolites (BAs) are among the most frequently detected compounds in liquid fermented foods, raising significant concerns about the potential risks they pose. To rapidly and selectively determine BAs, this study proposed and validated a method for the simultaneous determination of 13 BAs in liquid fermented foods using high performance liquid chromatography-triple quadrupole/linear ion trap mass spectrometry (HPLC-QTRAP-MS) without derivatization. The simultaneous separation and determination of histamine (HIS), tyramine (TYR), putrescine (PUT), octopamine (OCT), 2-phenylethylamine (2-PHE), dopamine (DOP), spermidine (SPD), epinephrine (EPI), agmatine (AGM), 5-hydroxytryptamine (5-HYD), tryptamine (TRY), L-noradrenaline (L-NOR), cadaverine (CAD) were achieved using a Waters Atlantis Premier BEH Z-HILIC (1.7 μm particle size, 100 mm × 2.1 mm id) column with a mobile phase consisting of water (containing 0.025 % formic acid) and acetonitrile (containing 0.1 % formic acid). The analysis of target compounds was performed with electrospray ionization (ESI) in positive ion mode, multiple reaction monitoring (MRM), information dependent acquisition (IDA), enhanced product ion (EPI), and multi-step mode analysis combined with EPI library searching. To enhance the extraction efficiency of BAs, factors such as extraction solvent, filter membranes, extraction methods, pH, oscillation speed, time and temperature were systematically investigated. The results demonstrated that the method exhibited low limits of detection (LOD) and quantification (LOQ), ranging from 0.05 to 2.00 µg/L and 0.16 to 6.60 µg/L, respectively. The method also showed satisfactory reproducibility, with intra-day and inter-day relative standard deviations ranging from 0.90 % to 3.80 % and 2.65 % to 8.27 %, respectively. Additionally, it had a broad linear range from 0.05 to 200.00 µg/L with excellent linearity (R>0.99) and an average recovery rate between 65.68 % and 115.14 %. Overall, the results demonstrated that the established method was convenient to operate, offered a short analysis time, and achieved high accuracy and sensitivity. It met the qualitative and quantitative requirements for detecting 13 BAs in liquid fermented food, thus providing strong technical support for BAs detection.

Approach for concurrent detection and removal of diclofenac in wastewater: Integration of MOF with Poly(deep eutectic solvent) imprinting method

Diclofenac in medical wastewater poses a significant threat to the environment and human health. A simple and efficient enrichment strategy has been established for the selective identification and removal for diclofenac in environmental water samples applying MOF based polymeric deep eutectic solvent (Poly(DES)@MOF). Poly(DES)@MOF was synthesized using a surface imprinting method. The components included MOF-199 as the support material, diclofenac as the template, and a deep eutectic solvent (DES) composed of choline chloride and methacrylate (1:2) as the functional monomer. Density functional theory calculated the Gibbs free energy change during the reaction process, confirming that DES improved the binding performance and selectivity of polymer. Related experiments have shown that Poly (DES) @ MOF has high adsorption capacity, reaching equilibrium within 2 h. In real sample experiments, the maximum adsorption capacity of diclofenac in lake water by the extraction device was 19.39 mg·g−1, with an average recovery rate between 99.4 % and 105.8 %. After 5 repeated uses, the performance did not show significant degradation. After evaluating the principles of green analytical chemistry using agree software, the total score was 0.68, reflecting the high greenness of this study. This study combined molecular imprinting technology and computer theory simulation of MOF based and DES mediated polymerization processes to construct an extraction device that was easy to operate and could extract diclofenac from environmental water samples with high selectivity and adsorption capacity. It showed great potential in the field of environmental monitoring and provided a new approach for the detection of other pollutants in the environment.

A comprehensive evaluation of Cell Elution Method (CEM) for forensic DNA analysis from smoked cigarettes

Cigarette stubs are commonly encountered trace DNA samples at crime scenes. Standard laboratory practice typically involves direct lysis of the stub for DNA extraction, leading to the co-extraction of DNA-degrading and inhibiting constituents from smoke and tobacco. This process can result in lower-quality DNA profiles. There has been limited focus on developing specific sample processing techniques that minimize these degrading agents and inhibitors before DNA extraction, which could significantly enhance the quality of DNA profiles. This study evaluates a previously established Cell Elution Method (CEM) against the conventional Direct Lysis Method (DLM) for DNA extraction from cigarette stubs. DNA quantity, quality, and subsequent STR profiles were assessed in 80 smoked cigarette stubs, comprising both flavoured and unflavoured types. While CEM exhibited comparable DNA yield from both flavoured (0.17 ng) and unflavoured (0.19 ng) cigarettes, DLM showed significant variability in average DNA yield for unflavoured (0.05 ng) and for flavoured (0.25 ng) cigarettes. Notably, CEM-treated samples demonstrated lower Degradation Index (DI) values compared to DLM-treated ones for both the types of cigarettes. Consequently, STR profiling success rates were higher with CEM, with 95 % of flavoured and 55 % of unflavoured samples yielding informative profiles, compared to 80 % and 0 %, respectively, for DLM. In unflavoured stubs, Amelogenin marker amplification was achieved in 35 % of CEM-treated samples, significantly outperforming the 5 % success rate with DLM. Additionally, CEM resulted in higher average allele recovery rates for both flavoured (58.98 %) and unflavoured (33.41 %) samples compared to DLM. These findings indicate that CEM outperforms DLM in producing higher-quality DNA profiles from cigarette stubs. Thus, CEM can be a choice of method for processing cigarette stub prior to DNA extraction.

Sensitive and selective fluorescence detection of acetamiprid using oxidized single-walled carbon nanohorns and cryonase-assisted signal amplification

To address the low accuracy of pesticide residue detection in traditional Chinese medicine, we developed a biosensor for acetamiprid detection. First, an oxidized single-walled carbon nanohorn capable of adsorbing and quenching fluorescence was prepared. Second, a novel fluorescence sensing system was constructed based on this nanomaterial. The detection performance of the sensor system was evaluated, which revealed that fluorescence quenching by the biosensor was primarily due to the adsorption of the aptamer by the nanomaterials. Optimal conditions were found to be a nanomaterial mass concentration of 800 ng/mL and an incubation time of 70 min, which resulted in the best fluorescence response. Under these optimal conditions, the system was used to detect acetamiprid residues in traditional Chinese medicine. The fluorescence intensity showed a strong linear relationship with acetamiprid concentration, with a correlation coefficient of 0.9985 and a detection limit of 6.33 ng/mL. In the sample test, the biosensor demonstrated high accuracy, with good average recovery rates and low relative standard deviation. The system showed excellent selectivity and detection performance, with no interference from other pesticides.

Efficient concentration of viral nucleic acid in wastewater through surfactant releasing and a two-step magnetic bead extraction and purification

Wastewater-based epidemiology (WBE) is a valuable complement to clinical monitoring, allowing for effective surveillance of viral infections in populations, and tracking the presence and the epidemiological dynamics of various infectious pathogens in communities. However, virus loads are usually low-abundant in wastewater, and current virus concentration methods for WBE are laborious and time-consuming with low recovery efficiency. To address these challenges, we have developed a magnetic bead-based semi-automated method involving extraction and purification to directly concentrate viral nucleic acids from sewage within 55 min. Prior to concentration, 0.5 % LDS was introduced to pretreat wastewater to inactivate viruses and release viral nucleic acids from both liquid and solid fractions to improve recovery. Under optimal conditions, the concentration method combined with reverse transcription-quantitative polymerase chain reaction (RT-qPCR) can detect severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) RNA added exogenously in wastewater as low as 4.9 copies/mL within 2.5 h, with an average recovery rate exceeding 80 %. Testing real sewages proved the applicability of the method to detect multiple viruses in different sewages. Additionally, variants of SARS-CoV-2 were successfully identified by multiplex amplicon sequencing in two samples. In conclusion, the new method could provide a much more efficient way for WBE of pathogenic viruses in various sewages.

Remote sensing reveals trends in vegetative recovery and land cover transformation post-reclamation at tar creek superfund site

The harmful effects of mining waste on human and ecosystem health make reclamation of former mine sites an environmental management priority. However, field-based monitoring of reclamation requires significant investments of time, labor, and money. Remote sensing offers a less expensive alternative to field-based monitoring, but work is still needed to determine which metrics can be reliably estimated using remote sensing techniques. This study uses remote sensing to examine over 20 years of reclamation efforts at Tar Creek Superfund Site and to assess revegetation after site restoration. Using the Normalized Difference Vegetation Index (NDVI), we quantify key factors affecting vegetation recovery and stability after reclamation across 123 surface mining waste cleanup locations within Tar Creek. Leveraging long-term imagery from Landsat and high-resolution PlanetScope imagery, we combine time series analysis of vegetation regrowth and landcover change detection for a comprehensive picture of recovery at each site. Across all reclamation sites, the average recovery duration was 3.5 years, and average recovery rate was 0.1 NDVI year−1. After vegetative growth had plateaued, reclaimed sites had an average NDVI of 0.70. All reclamation areas were converted from majority barren landcover to vegetated landcover classes after reclamation, and vegetative stability at reclamation sites was high (70% of reclaimed area saw continuous vegetative cover from 2017 to 2023). These results demonstrate a strong potential for multi-method remote sensing techniques in tracking and explaining vegetation recovery after reclamation and represent a cost-effective approach for real-time monitoring of reclamation progress and outcomes.

Integrated Application of Risk Management Techniques in Developing an Analysis Method for Traditional Chinese Medicine: A Case Study of a Percolation Solution for Xiaochaihu Capsules

Risk management should run through the entire process of method development, utilization, and maintenance. Based on the analytical quality by design (AQbD) concept, various integrated risk management techniques were used in this study to develop an analysis method for the percolation solution of Xiaochaihu capsules. During the development of the analysis method, risk assessment was conducted using an Ishikawa diagram and failure mode effects analysis, followed by method optimization using experimental design. The probability of nonconformance calculated via an exhaustive Monte Carlo method quantitatively characterized the risk magnitude of method parameter failures, leading to the establishment of a operable design region method based on risk magnitude. Validation experiments and robustness tests of the data were utilized for model refinement and initial risk review. Methodological validation of the developed method was performed, and control strategies for the analysis method were presented through a decision tree. Stability experiments demonstrated that the samples remained stable at 4 °C for 24 h. The average recovery rate fell between 98.8% and 105%, with relative standard deviations ranging from 2.73% to 4.48%. The results showed that the established analysis method exhibited robustness. This analysis method can simultaneously determine the contents of uridine, adenine, 5-hydroxymethylfurfural, and guanosine. This method can also be employed for process control during percolation. This study integrated various risk management techniques to develop and maintain the analysis method, and this approach can potentially be extended to other analytical methods.

Dynamics of a susceptible-infected-recovered model on complex networks with interregional migration.

We present a susceptible-infected-recovered model based on a dynamic flow network that describes the epidemic process on complex metapopulation networks. This model views population regions as interconnected nodes and describes the evolution of each region using a system of differential equations. The next-generation matrix method is used to derive the global basic reproduction number for three cases: a general network with homogeneous infection rates in all regions, a fully connected network, and a star network with heterogeneous infection and recovery rates. For the homogeneous case, we show that this global basic reproduction number is independent of the migration rates between regions. However, the rate of convergence of each region to an equilibrium state exhibits a much larger variance in random (Erdős-Rényi) networks compared to small-scale (Barabási-Albert) networks. For the general heterogeneous case, we report interesting results, namely that the global basic reproduction number decays exponentially with respect to the smallest nonzero Laplacian eigenvalue (algebraic connectivity). Furthermore, we demonstrate both analytically and numerically that as the network's algebraic connectivity increases, either by increasing the average node degree of each region or the global migration rate, the global basic reproduction number decreases and converges to the ratio of the average local infection rate to the average local recovery rate, meaning that the lower bound of the global basic reproduction rate does not equal the mean of local basic reproduction rates.

Unveiling Mispricing Risks: Nonlarge Homogeneous Portfolio Factor Copula Models for Enhanced Valuation of Subordinated Loan Securitization

AbstractThis paper presents an innovative factor copula model for collateralized loan obligation (CLO) tranche valuation, incorporating non‐Gaussian distributions and dynamic correlations without relying on the large homogeneous portfolio (LHP) assumption. Through numerical analyses and comparisons with LHP models, I find that non‐LHP models produce higher tranche spreads, especially for lower‐rated tranches. Sensitivity analysis reveals varying sensitivities to changes in the number of collaterals, risk‐free rate, average collateral ratings, recovery rates, and time to maturity. The non‐LHP one‐factor copula models, including stochastic correlation and random factor loading models, outperform LHP models in root mean squared errors when calibrated to market data. The results underscore the importance of considering model limitations in CLO tranche pricing and highlight potential mispricing of spread risk in higher‐rated tranches using LHP models. The proposed models contribute to a more comprehensive understanding of CLO tranche pricing by accounting for various factors and assumptions influencing fair premiums.

한중 양국 중소기업해외채권 회수제도 비교 연구

According to the Korea Trade Insurance Corporation, the amount of funds that have not yet received payment for exports in 2021 is 82 million US dollars (106.6 billion Korean won), and the total amount of accounts receivable in the past five years has reached 1.3 trillion Korean won. According to the Korea Trade Association, although the issuance scale of foreign bonds is increasing, the cumulative recovery rate is as low as around 30%. The average recovery rate of overseas accounts receivable owed by Chinese export enterprises is only 20%. Combined with a 5% export bad debt rate, it basically means that 4% of the annual export amount cannot be recovered. For small and medium-sized enterprises with weak risk resistance, cash flow is crucial for their survival. In general, there are two common ways to obtain compensation for uncollected debts: by purchasing pre export credit insurance or by seeking an ECA agency for agency recovery. The public export credit agencies (ECA) K-SURE and SINOSURE of the two countries are exploring the differences and similarities in overseas bond recovery systems, while hoping to provide better bond recovery methods for small and medium-sized enterprises and help with overseas bond recovery.

Visco-plastic deformation characteristics of accelerated-aging asphalt mixture containing reclaimed asphalt pavement regenerated with crumb rubber based on Hamburg Wheel-Track test

The regeneration of the reclaimed asphalt pavement (RAP) with incorporation of crumb rubber was a cleaner alternative for reducing the fossil and ore resources consumption. For the desert area like Egypt, the rut of reclaimed pavement was principal contradiction during a long service. This work mainly characterized the visco-plastic deformation of accelerated-aging rubberized reclaimed asphalt mixture based on Hamburg Wheel-Track test. Four mixtures were designed by two contents of RAP (15% and 30%), two contents of crumb rubber (5% and 15%), and two asphalts (pen-#70 and pen-#90). Specifically, this work focused on the determination of accelerated aging effect, and analysis of rutting deformation fitting including overall deformation and visco-plastic deformation. Then, effect of accelerated aging time and material compositions on visco-plastic deformation was analyzed. In addition, the correlation analysis among indicators evaluating rutting deformation of mixture was conducted, and the correlation analysis between rutting deformation of mixture and average recovery rate at 3.2 kPa of extracted bitumen was completed. The results demonstrated that the accelerated aging equivalent factor of sunlight was approximately 6, meaning that one day of accelerated aging was equivalent to six days of natural aging in Cairo. With the accelerated aging time increased, resistance to rutting deformation of rubberized reclaimed asphalt mixture was promoted with the incorporation of RAP, crumb rubber and soft matrix binder. Meanwhile, dynamic stability, derived from fitting curve of visco-plastic deformation, was positively correlated with accelerated aging time, and it could accurately evaluate visco-plastic deformation characteristics of reclaimed mixture. Finally, visco-plastic deformation characteristics of reclaimed mixture was closely related to the permanent deformation resistance of binder at high temperature.

Screen-printed carbon electrode functionalized with AuNPs-cysteamine self-assembled monolayers for enzymatic uric acid detection in non-invasive samples.

Uric acid (UA) is a relevant biomarker that at abnormal levels could provide information for the timely diagnosis of chronic-degenerative diseases, such as Diabetes mellitus, cardiovascular deficiencies or gut. This work presents a simple surface functionalization of screen-printed carbon electrodes (SPCE) with cysteamine self-assembled monolayers (SAMs) assembled over electrodeposited gold nanoparticles (AuNPs). The modification allowed the immobilization of uricase enzyme, preserving its biocatalytic activity and resulting in sensitive and selective UA detection. The developed biosensor device exhibited a linear detection range from 100 μM – 1000 μM, a sensitivity of 6.622 nA/μM and a limit of detection (LOD) of 4.6 μM with selectivity to UA molecules over common interfering analytes. When evaluated in urine samples, the analytical capabilities of the PTSPCE/AuNPS/SAMs/Uox biosensor remained, achieving an average recovery rate of 126.91%. The obtained analytical parameters proved to be competitive when utilizing non-invasive fluids, suggesting the possibility of conducting detection assays with potential clinical applications using an implemented electrochemical biosensor through a simple, flexible, and reproducible methodology.

A dual-scale fused hypergraph convolution-based hyperedge prediction model for predicting missing reactions in genome-scale metabolic networks.

Genome-scale metabolic models (GEMs) are powerful tools for predicting cellular metabolic and physiological states. However, there are still missing reactions in GEMs due to incomplete knowledge. Recent gaps filling methods suggest directly predicting missing responses without relying on phenotypic data. However, they do not differentiate between substrates and products when constructing the prediction models, which affects the predictive performance of the models. In this paper, we propose a hyperedge prediction model that distinguishes substrates and products based on dual-scale fused hypergraph convolution, DSHCNet, for inferring the missing reactions to effectively fill gaps in the GEM. First, we model each hyperedge as a heterogeneous complete graph and then decompose it into three subgraphs at both homogeneous and heterogeneous scales. Then we design two graph convolution-based models to, respectively, extract features of the vertices in two scales, which are then fused via the attention mechanism. Finally, the features of all vertices are further pooled to generate the representative feature of the hyperedge. The strategy of graph decomposition in DSHCNet enables the vertices to engage in message passing independently at both scales, thereby enhancing the capability of information propagation and making the obtained product and substrate features more distinguishable. The experimental results show that the average recovery rate of missing reactions obtained by DSHCNet is at least 11.7% higher than that of the state-of-the-art methods, and that the gap-filled GEMs based on our DSHCNet model achieve the best prediction performance, demonstrating the superiority of our method.