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Fungicide residues of soil samples taken from Batak Plain of Çanakkale province of Türkiye were assessed. Fungicide residue analyses were performed with the use of QuEChERS method and LC-MS/MS device. Blank samples were spiked at two different limit of quantification (LOQ) levels for method verification. Overall recovery was identified as 85.69% with an RSD of 12.36% (n=360; SD=10.59). A total of 110 soil samples were taken in November 2020. Present analyses revealed that 59.09% of samples contained fungicide residues at different concentrations. Propiconazole had the highest concentration (1736.06 μg/kg) in one sample, taken from the edge of the field where pesticide wastes were found and 26 fungicides were found at different concentrations in the same sample. Azoxystrobin was encountered in majority of the samples (29 samples). The most frequent fungicides were ordered as; boscalid and tebuconazole (22 samples) > metalaxyl (17 samples) > fluopyram (15 samples). Thirteen triazole fungicides were found in soil samples, mostly at moderately hazardous level (Class II). Risk assessments revealed that hazard levels of fungicides for adults and children were low with a hazard quotient (HQ) and hazard index (HI) of <1. Despite the safe nature of fungicides in soil samples, the greatest HQ values were identified for propiconazole (326.52E-08 for adults and 2449.00E-08 for children). The sum of hazard quotients for all fungicides was 86.31E-08 8 for adult and 647.35E-08 for children. In terms of soil pollution, it is important for farmers to apply fungicides with low HQ levels.

The validation of analytical procedures is included as part of drug registration applications submitted within the European Union, Japan, and the United States. In addition, such analytical procedure validation is also required for compendial (USP) submissions in support of the development or revision of public standards (monographs) that Food and Drug Administration (FDA) enforces in the United States. This chapter highlights general guideline for the determination of the analytical characteristics for different types of validation procedures for the analysis of both the drug substance and drug product. The validation characteristics used in this chapter are general in nature and apply to most typical and routine methods such as chromatographic and spectroscopic tests used in pharmaceutical laboratories. The chapter discusses the factors to consider for verification of the compendial procedures. In addition, it describes different approaches for the transfer of analytical procedure from one lab (transferring) to other lab(s) (receiving) under different circumstances.

This chapter contains sections titled: Introduction Cycle of Analytical Methods Method Verification Practices Method Revalidation Method Transfer Common Problems and Solutions References

An active targeting strategy-enabled DNA tetrahedron delivery vehicle could facilitate stable drug encapsulation and stimuli-responsive on-demand release, building a universal platform for different drug delivery requirements. Owing to the excellent biocompatible nature, programmability and remarkable cell and tissue permeability, the tetrahedral DNA nanostructure (TDN) has proven its value in the delivery of various bioactive molecules. We previously described this as a static multifunctional complex in our earlier protocol. However, static structures and passive targeting behavior might introduce off-target effects under complicated biological conditions. Therefore, in this Protocol Extension, we present a major update of the TDN delivery vehicle enabling an active targeting strategy to be used for stimuli-sensitive conformation changes and on-site cargo release, which could avoid drawbacks, including complex and time-consuming fabrication processes and undetermined cell penetration ability of other DNA-based delivery vehicles. Upon exquisite design of TDN size based on cargo type, one-pot annealing is applied to fabricate the Tiamat-designed TDN exoskeleton. Then the design of the dynamic DNA apparatus can be based on the target and environmental stimuli, including DNA strand hybridization-based and pH-sensitive DNA apparatus, and careful titration of strand lengths and mismatches is achieved using polyacrylamide and agarose gel electrophoresis, or fluorophore modifications. Finally, cargo loading strategies are designed, including site and stand titration and cargo encapsulation verification. The dynamic structures show promising targetability and effectiveness in antitumor and anti-inflammatory treatment in vitro and in vivo. Assembly and characterization in the lab takes ~5 d, and the timing for the verification of biostability and biological applications depends on the uses. This Protocol Extension presents an updated tetrahedral DNA nanostructure for the delivery of various bioactive molecules that enables an active targeting strategy to be used for stimuli-sensitive conformation changes and on-site cargo release.

In order to obtain scaffold that can meet the therapeutic effect, researchers have carried out research on irregular porous structures. However, there are deficiencies in the design method of accurately controlling the apparent elastic modulus of the structure at present. Natural bone has a gradient porous structure. However, there are few studies on the mechanical property advantages of gradient bionic bone scaffold. In this paper, an improved method based on Voronoi-tessellation is proposed. The method can get controllable gradient scaffolds to fit the modulus of natural bone, and accurately control the apparent elastic modulus of porous structure, which is conducive to improving the stress shielding. To verify the designed structure can be fabricated by additive manufacturing, several designed models are obtained by SLM and EBM. Through finite element analysis (FEA), it is verified that the irregular porous structure based on Voronoi-tessellation is more stable than the traditional regular porous structure of the same structure volume, the same pore number and the same material. Furthermore, it is verified that the gradient irregular structure has a better stability than the non-gradient structure. An experiment is conducted successfully to verify the stability performance got by FEA. In addition, a dynamic impact FEA is also performed to simulate impact resistance. The result shows that the impact resistance of the regular porous structure, the irregular porous structure and the gradient irregular porous structure becomes better in turn. The mechanical property verification provides a theoretical basis for the structural design of gradient irregular porous bone tissue engineering scaffolds.

This paper presents a summary and meta-analysis of the first three iterations of the annual International Verification of Neural Networks Competition (VNN-COMP), held in 2020, 2021, and 2022. In the VNN-COMP, participants submit software tools that analyze whether given neural networks satisfy specifications describing their input-output behavior. These neural networks and specifications cover a variety of problem classes and tasks, corresponding to safety and robustness properties in image classification, neural control, reinforcement learning, and autonomous systems. We summarize the key processes, rules, and results, present trends observed over the last three years, and provide an outlook into possible future developments.

Significance: Code verification is an unavoidable step prior to using a Monte Carlo (MC) code. Indeed, in biomedical optics, a widespread verification procedure for MC codes is still missing. Analytical benchmarks that can be easily used for the verification of different MC routines offer an important resource. Aim: We aim to provide a two-step verification procedure for MC codes enabling the two main tasks of an MC simulator: (1) the generation of photons’ trajectories and (2) the intersections of trajectories with boundaries separating the regions with different optical properties. The proposed method is purely based on elementary analytical benchmarks, therefore, the correctness of an MC code can be assessed with a one-sample t-test. Approach: The two-step verification is based on the following two analytical benchmarks: (1) the exact analytical formulas for the statistical moments of the spatial coordinates where the scattering events occur in an infinite medium and (2) the exact invariant solutions of the radiative transfer equation for radiance, fluence rate, and mean path length in media subjected to a Lambertian illumination. Results: We carried out a wide set of comparisons between MC results and the two analytical benchmarks for a wide range of optical properties (from non-scattering to highly scattering media, with different types of scattering functions) in an infinite non-absorbing medium (step 1) and in a non-absorbing slab (step 2). The deviations between MC results and exact analytical values are usually within two standard errors (i.e., t-tests not rejected at a 5% level of significance). The comparisons show that the accuracy of the verification increases with the number of simulated trajectories so that, in principle, an arbitrary accuracy can be obtained. Conclusions: Given the simplicity of the verification method proposed, we envision that it can be widely used in the field of biomedical optics.

This work presents a comprehensive and chronologically ordered survey of existing studies and data sources on Electrocardiogram (ECG) based biometric recognition systems. This survey is organized in terms of the two main goals pursued in it: first, a description of the main ECG features and recognition techniques used in the existing literature, including a comprehensive compilation of references; second, a survey of the ECG databases available and used by the referenced studies. The most relevant characteristics of the databases are identified, and a comprehensive compilation of databases is given. To date, no other work has presented such a complete overview of both studies and data sources for ECG-based biometric recognition. Readers interested in the subject can obtain an understanding of the state of the art, easily identifying specific key papers by using different criteria, and become aware of the databases where they can test their novel algorithms.

Various frameworks and methods, such as quality by design (QbD), real time release test (RTRT), and continuous process verification (CPV), have been introduced to improve drug product quality in the pharmaceutical industry. The methods recognize that an appropriate combination of process controls and predefined material attributes and intermediate quality attributes (IQAs) during processing may provide greater assurance of product quality than end-product testing. The efficient analysis method to monitor the relationship between process and quality should be used. Process analytical technology (PAT) was introduced to analyze IQAs during the process of establishing regulatory specifications and facilitating continuous manufacturing improvement. Although PAT was introduced in the pharmaceutical industry in the early 21st century, new PAT tools have been introduced during the last 20 years. In this review, we present the recent pharmaceutical PAT tools and their application in pharmaceutical unit operations. Based on unit operations, the significant IQAs monitored by PAT are presented to establish a control strategy for CPV and real time release testing (RTRT). In addition, the equipment type used in unit operation, PAT tools, multivariate statistical tools, and mathematical preprocessing are introduced, along with relevant literature. This review suggests that various PAT tools are rapidly advancing, and various IQAs are efficiently and precisely monitored in the pharmaceutical industry. Therefore, PAT could be a fundamental tool for the present QbD and CPV to improve drug product quality.

Digoxin, a cardiac glycoside, is widely used in the treatment of cardiovascular diseases. Due to its narrow therapeutic range, precise monitoring of its blood concentration is essential. A reference measurement procedure (RMP) is pivotal for ensuring result accuracy and comparability. The RMP for serum digoxin by ID-LC-MS/MS was optimized with sample pre-treatment and detection processes, and the bracketing calibration method was used, which facilitates more accurate measurement, especially for extreme concentrations. The performance of this optimized RMP was thoroughly evaluated. The limit of detection (LoD) was 0.05 ng/mL (0.06 nmol/L) and the lowest limit of quantification (LLoQ) was 0.10 ng/mL (0.13 nmol/L). The intra- and inter-assay imprecisions were 2.24%, 2.51%, 1.40% and 1.72%, 1.65%, 0.97% at 0.5, 2.0, 5.0 ng/mL, respectively. Recoveries were 99.63 to 101.42% and the linear response ranged from 0.1 to 10.0 ng/mL. The relative bias was 0.41% and 2.00% of our results compared with the median of all participating reference laboratories for IFCC-RELA (External Quality Assessment Scheme for Reference Laboratories in Laboratory Medicine) 2023A and 2023B. The uncertainty, calibration and measurement capability (CMC) of this method were also evaluated. The optimized RMP was applied in the Trueness Verification Plan of Southern China, which indicates significant differences among clinical systems, highlighting the need for standardization efforts. In addition, two commonly used clinical systems which employed immunoassay methods were compared with this optimized RMP, and 26 individual serum samples were analyzed. The good correlations indicate the feasibility of standardization for serum digoxin. The optimized RMP serves as an accurate reference baseline for routine methods, aiming to enhance the accuracy and precision of measurements in clinical laboratories.