All-perovskite tandem solar modules offer the potential to achieve rapid increases in power conversion efficiency (PCE), yet efficient lead-tin (Pb-Sn) subcells often contain thermally unstable methylammonium (MA). Replacing MA with cesium (Cs) has been adopted to improve thermal stability but results in nonuniform nucleation and rapid crystallization, degrading large-area film quality. Here, we introduce p-π conjugated semicarbazide hydrochloride (SHCl) as a crystallization modifier in precursor solutions. The SH+ and Cl- ions synergistically modulate the precipitation of Cs components and the growth process of perovskite films, achieving homogeneous nucleation and retarded crystal growth in formamidinium-cesium (FACs)-based Pb-Sn perovskites. Single-junction FACs Pb-Sn devices retained 85% of the initial efficiency after 700 hours at 85°C. The resultant all-perovskite tandem modules (20.25square centimeters) achieved the certified PCE of 24.3%, representing the highest certified PCE among MA-free all-perovskite tandem modules. Encapsulated modules maintained 90 and 92% of their initial efficiency under ISOS-standardized damp heat (200 hours) and thermal cycling (200 cycles) tests, respectively.

Semicarbazide (SEM), a metabolite of nitrofurazone, poses potential risks as a carcinogen and teratogen in animal-derived foods. This research is centered on creating a homemade electrochemical sensor with high sensitivity for detecting SEM with dual signals. The working electrode was modified through the in-situ growth of a copper-iron bimetallic organic framework (Cu/Fe-BTC) on carbon cloth (CC), followed by the decoration of gold nanoparticles (AuNPs) on the Cu/Fe-BTC/CC surface. The Cu/Fe-BTC component provides abundant metallic active sites, resulting in a distinct [Fe(CN)6]3-/4- peak observed at 0.67 V (I1, vs. SCE). Concurrently, the incorporation of AuNPs enhances the electrode high electron transfer capacity, which amplifies the signal peaked at 0.18 V (I2, vs. SCE), thereby establishing an effective dual-signal detection system. Furthermore, a molecularly imprinted polymer (MIP) layer was electropolymerized onto the modified electrodes, utilizing resorcinol as the functional monomer and SEM as the template. Then, the peak intensities of the dual signals decreased upon target (SEM) recognition and increased during template elution, generating a measurable detection signal. By calculating the current changes, ΔID = ΔI1 + ΔI2, the adsorbed template molecule concentration could be quantified. Under optimal conditions, the sensor has excellent stability, accuracy, and repeatability in analyzing various samples, including serum, urine, meat, egg, honey, canned food, flour, milk powder, fish, and shrimp. The determination range is linear, spanning from 0.005 to 100 nM, with a limit of detection at 3.9 pM. Therefore, the Cu/Fe-BTC and AuNPs-based MIP sensor represents a reliable dual-signal strategy for the quantitative determination of SEM.

This study aimed to investigate the effects of sodium hypochlorite (NaClO) bleaching on the quality of Basa (Pangasius bocourti) fish maw (BFM) and the formation of semicarbazide (SEM). Production of SEM increased (p < 0.05) when NaClO concentration, soaking temperature, or duration were increased. Notably, increasing NaClO solution pH also enhanced SEM formation. Soaking BFM in NaClO with available chlorine concentrations of 500, 700, and 1000 mg/L generated 0.05, 0.07, and 0.09 μg/kg SEM at pH 3 compared to 0.70, 1.19, and 2.34 μg/kg SEM at pH 11, respectively. NaClO improved BFM texture by creating a tight, fibrous structure, but also damaged the secondary structure and α-chains of collagen. Untargeted metabolomics showed that NaClO treatment significantly upregulated lipid metabolism pathways (biosynthesis of unsaturated fatty acids, linoleic acid metabolism, and glycerophospholipid metabolism) and elevated degradation of arginine, proline, and urocanic acid. This was associated with the accumulation of nitrogen-containing precursors in the urea cycle, which then reacted with NaClO, generating substantial SEM. Controlled SEM-generating reactions experiments confirmed that SEM was produced from reaction of urea and NaClO. This study elucidates the mechanism of SEM formation and identifies key factors influencing SEM levels, thereby providing a theoretical foundation for safe processing and quality control of fish maw.

Advances in the detection of azodicarbonamide and the metabolic product semicarbazide.

A high-resolution mass spectrometry (HRMS) method was developed and optimized for quantitative and confirmatory analysis of the nitrofurazone (NFZ) cyano metabolite in shrimp. Extraction with 80% acetonitrile: buffer, salting out, and solid phase cartridge cleanup resulted in 87-112% recovery, <10% precision, and good sensitivity with 0.02 ppb limit of quantitation. Current monitoring of unauthorized NFZ use in aquaculture relies upon semicarbazide (SEM) metabolite detection; however, the natural occurrence of SEM in some crustaceans has raised interest for an alternative biomarker. The developed method was used to investigate the suitability of cyano metabolite as an alternate biomarker for unauthorized use of NFZ. In NFZ-incurred shrimp, the cyano metabolite depleted rapidly, with no detection after 6 days, while SEM was detected for at least 20 days. The short-lived stability of cyano metabolite limits its potential for nitrofurazone surveillance in shrimp. However, the method may be adequate for NFZ surveillance in other food animal matrices.

In this study, a green and efficient method has been developed for the preparation of aryl semicarbazones using Kigelia pinnata flower-derived carbon quantum dots (KP-CQDs) as a sustainable catalyst. The reaction between various aldehydes/acetophenones and semicarbazide (SC) hydrochloride was carried out smoothly at room temperature in an ethanol-water (1:4) solvent system, and excellent yields (83%-95%) were achieved within a short reaction time of 5-20min, demonstrating the high catalytic efficiency of KP-CQDs. A total of nine derivatives were synthesized, among which six compounds are reported for the first time. Furthermore, the biological potential of these compounds was investigated through in silico studies. The molecules were subjected to prediction of activity spectra for substances (PASS) online prediction to predict probable biological targets, and based on these predictions, molecular docking was performed against human mitochondrial 3-hydroxy-3-methylglutaryl-coenzyme A synthase 2 (Protein Data Bank [PDB] ID: 2WYA), hepatitis A virus 3C protease (PDB ID: 1HAV), and foot-and-mouth disease virus (FMDV) 3C protease (PDB ID: 2WV4). On conducting molecular docking, molecules 3f (-15.57kcal/mol), 3c (-5.61kcal/mol), and 3e (-9.44kcal/mol) showed remarkable activity with 2WYA, 1HAV, and 2WV4, respectively. This method offers several key advantages, including the use of a green and reusable CQD catalyst, mild reaction conditions, short reaction times, excellent yields, and the preparation of new semicarbazone derivatives with unexplored biological activities.

Nitrofurazone and its metabolite semicarbazide (SEM) residues present in food products pose substantial health hazards to humans. Herein, the colorimetric–fluorescent lateral flow immunoassay (LFIA) for 4[(4-carboxyphenyl)-methylene]-hydrazinecarboxamide (CPSEM) detection was developed using PCN-222@Pectin as a signal tag. Herein, the PCN-222 surface was subsequently modified with pectin to enhance its aqueous solubility and stability. The PCN-222@Pectin-LFIA system exhibited a broad linear range from 0.025 ng/mL to 100 ng/mL. The low limits of detection for the colorimetric and fluorescence-based detection methods were 0.1 and 0.05 ng/mL, respectively. Notably, these values represent a 10- and 20-fold higher sensitivity than that of the traditional colloidal gold nanoparticle-based LFIA. This method was successfully used to detect CPSEM in actual samples, with recovery rates of 89.34 %–120.80 %. This approach fulfills the need for on-site preliminary qualitative assessment during detection and permits subsequent accurate quantitative analysis.

Semicarbazide conferred developmental toxicity in Oryzias melastigma embryos by oxidative stress and energy metabolism disorder.

In this study, a series of novel cyclic imides linked to imidazopyridine was synthesized through multi-step reactions.The synthesis began with the reaction of 2-aminopyridine and 4-bromophenacyl bromide to obtain 2-(4-bromophenyl)imidazo[1,2-a]pyridine (A1).This intermediate was further reacted with 2-aminobenzoic acid under acid conditions to give the Mannich base (A2), followed by ring closure using semi carbazide and POCl3, yielding 2-aminooxadiazole (A3).Subsequent reactions with different anhydrides produced amic acid derivatives (A4-A6), which were cyclized into novel cyclic imides (A7-A9) via thermal dehydration.The synthesized compounds were characterized by 1 H NMR, 13 C NMR, and FT-IR spectroscopy.Electrochemical anticorrosion studies were conducted for compounds A7-A9 using potentiodynamic polarization techniques in 1 M HCl solution, revealing significant inhibition efficiency.Among the tested compounds, A9 exhibited the highest protection efficiency, correlating well with computational results obtained via Density Functional Theory (DFT) and Molecular Dynamics (MD) simulations.These results highlight the potential application of these novel cyclic imides as effective corrosion inhibitors for carbon steel.

Introduction.In this study there are presented the results of selecting a sorbent for clean-up of an extract of 4 nitrofuran metabolites extracted from the meat, preparing a solid-phase column with this sorbent, and confirming the advantages of this column using validation of method.Materials and methods.The extract was clean-up using a solid-phase column, prepared by us with the sorbent Silica gel 60; identification and quantitative determination of nitrofuran metabolites: 3-amino-2-oxazolidinone (AOZ), 3-amino 5methylmorpholino-2-oxazolidinone (AMOZ), 1-aminohydantoin (AHD), semicarbazide (SEM), and their nitrophenyl derivatives was carried out using a high-performance liquid chromatography with diode array detector.Results and discussion.Based on the physicochemical properties of the analyzed substances, sorbents and literature data, two sorbents were selected -silica gel 60 and a polymer sorbent -polypropylene, which is most often used in ready-made columns for nitrofuran purification.Columns were made from the selected sorbents and their suitability was determined.The advantage of the manufactured columns using silica gel was experimentally proven.96-98% extraction of nitrofuran metabolites was achieved with good reproducibility (RSD 2.0%), since when using a polymer sorbent, the extraction does not exceed 94%.When using silica gel 60, the limit of quantification for metabolites -AOZ, AMOZ, AHD and SEM is within 0.1-0.12g/kg, for their nitrophenyl derivatives (NP) within -0.11-0.14g/kg.The decision limit is within 0.01-0.07g/kg.When using a polymer sorbent: the limit of quantification for metabolites -AOZ, AMOZ, AHD and SEM is within 0.21-0.32g/kg; for their NPs within 0.25-0.43g /kg.The decision limit is within 0.13-0.28g/kg.Conclusions.Silica gel 60 and columns prepared with this sorbent were identified as preferable for the purification and concentration of nitrofuran metabolites isolated from meat.The advantages of the proposed column over disposable, expensive, commercially available columns were demonstrated through method validation.

Abstract N‐ heterocycles have been proven as significant corrosion inhibitors for mild steel due to their excellent binding ability with metallic surfaces. In this study, we have designed and synthesized new isatin‐based hybrids ( ISA and IST ) via condensation of isatin with semicarbazide hydrochloride, followed by Cu(I)‐catalyzed click reaction. After successful characterization, these molecules were evaluated for their corrosion inhibition activity toward mild steel in an acidic medium (1 M HCl) using potentiodynamic polarization (PDP), electrochemical impedance spectroscopy (EIS), and weight loss measurements. Triazole hybrid ( IST ) exhibited maximum corrosion inhibition efficiency ( η eis % = 95.20%, η pol % = 92.84%, η WL % = 97.03%) at a concentration of 500 ppm in 1 M HCl. SEM and EDX analysis revealed that inhibitor molecules prohibited corrosion by forming a protection layer on it. DFT calculations indicated that the synthesized molecules have lower hardness ( η ) and higher softness ( σ ) values, means more effective in inhibiting corrosion. Molecular dynamics (MD) studies were also performed to have an insight about interaction modes, preferred orientation of the molecule over the metal surface, and interaction energies. Results of in silico studies were found to be in good agreement with the experimental studies.

In the fabrication of FAPbI3-based perovskite solar cells, Lewis bases play a crucial role in facilitating the formation of the desired photovoltaic α-phase. However, an inherent contradiction exists in their role: they must strongly bind to stabilize the intermediate δ-phase, yet weakly bind for rapid removal to enable phase transition and grain growth. To resolve this conflict, we introduced an on-demand Lewis base molecule formation strategy. This approach utilized Lewis-acid-containing organic salts as synthesis additives, which deprotonated to generate Lewis bases precisely when needed and could be reprotonated back to salts for rapid removal once their role is fulfilled. This method promoted the optimal crystallization of α-phase FAPbI3 perovskite films, ensuring the uniform vertical distribution of A-site cations, larger grain sizes and fewer voids at buried interfaces. Perovskite solar cells incorporating semicarbazide hydrochloride achieved an efficiency of 26.1%, with a National Renewable Energy Laboratory-certified quasi-steady-state efficiency of 25.33%. These cells retained 96% of their initial efficiency after 1,000 h of operation at 85 °C under maximum power point tracking. Additionally, mini-modules with an aperture area of 11.52 cm2 reached an efficiency of 21.47%. This strategy is broadly applicable to all Lewis-acid-containing organic salts with low acid dissociation constants and offers a universal approach to enhance the performance of perovskite solar cells and modules.

Regulatory bodies aim to protect consumers from harmful substances. The use of certain antibiotics is prohibited in food-producing animals in the EU due to their potential detrimental effects on humans. Among these are nitrofuran antibiotics, which degrade rapidly so that their metabolites are used as markers in screening for their illegal use. The use of one metabolite, semicarbazide (SEM), as a marker for detecting the antibiotic nitrofurazone, has been criticized due to the many pathways it can be formed by and its natural occurrence in some food items. A recent change in the reference point of action (RPA) for SEM, as stated in Commission Regulation (EU) 2019/1871, due to a reassessment of sensitivity of the analyses, poses a problem for the export of heather honey in Norway. Norwegian heather honey seems to exceed the lowered RPA in numerous cases. Here we show that Norwegian heather honey samples, but not polyfloral ‘summer’ honey samples from the same hives, contain SEM. The simplest explanation for the demonstrated pattern is a natural source of SEM in heather honey, not the use of a banned antibiotic. Based on our results, we propose that an exception to the EU regulation should be added, exempting heather honey derived from Calluna vulgaris unless other nitrofurans or their metabolites are found together with SEM.

Semicarbazide (SEM), a metabolite of nitrofurazone (NFZ), is widely used to detect the illegal application of NFZ in crustaceans. The conventional detection method involves chemical derivatization combined with reversed-phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS), which is both complex and time-consuming. To address this limitation, a more efficient approach was developed for SEM detection. This study introduces a modified QuEChERS pretreatment method coupled with hydrophilic interaction liquid chromatography-tandem mass spectrometry (HILIC-MS/MS) for detecting SEM in crustaceans. The proposed method is simple, fast, and highly accurate, making it universally applicable for SEM detection in crustaceans. Additionally, the method was applied to investigate NFZ metabolism in Macrobrachium rosenbergii with a kinetic model. The findings suggested a plausible mechanism for the absorption of NFZ and its subsequent transfer from meat to the shell. In conclusion, this study provides a simple and rapid technique for SEM detection in crustaceans with immense application value.

Nitrofurazone (NFZ), a synthetic antibiotic, is banned from use in food animals because of its potential carcinogenicity and mutagenicity. Regulatory agencies regularly surveil illegal use of NFZ in animal-derived products by measuring a marker metabolite, semicarbazide (SEM). However, SEM is not specific for NFZ exposure, and its detection has proven to return false positive results in unexposed animals. Therefore, the identification of a NFZ-specific marker is a pressing need for detecting illicit NFZ use. To this end, disposition and depletion studies in broiler chickens were performed using 14C-NFZ test articles containing radiocarbon at the furaldehyde carbon (NFZ-A) or the carbonyl carbon of SEM (NFZ-B). Birds were fed complete rations containing [14C]-NFZ-A (n = 12, Group A) or 14C-NFZ-B (n = 12, Group B) at 5 mg NFZ/kg feed for 7 consecutive days. Control birds (n = 6) were fed NFZ-free feed. Birds were euthanized on withdrawal days (WD) 0, 4, 7, and 14. Total radioactive residues in plasma, liver, kidney, muscle, gizzard, lung, and heart were determined by oxidation, followed by liquid scintillation counting. At WD 0, the kidney was the major depot for total radioactive residues followed by the liver. Depletion rates of radioactive residues in tissues were not different (P > 0.20) between the NFZ-A and NFZ-B treated groups, suggesting that the SEM moiety remained intact during biotransformation of both nitrofurazone test articles. Estimated half-life of radioactive residues was longer in muscle than that in the liver. About 70% or higher of NFZ-related residues remained unextractable and bound to tissues, regardless of the withdrawal day. Major portions of NFZ-residues were covalently bound to protein, with smaller portions bound to DNA and RNA fractions.

Nitrofurans (NFs) are commonly used medicines for bacteria and parasites in animal diseases. Their residues in food products have mutagenic and carcinogenic effects on humans. In this study, we investigated the presence of NF metabolites which are 3 amino 2 oxazolidinone (AOZ), semicarbazide (SEM), 5 methylemorpholino 3 amino 2 oxazolidinone (AMOZ), and 1 aminohydantoin (AHD) in raw cow milk and assessment of human health risks in the region of Ankara, Turkey. End of the result showed that the linearity, recovery, and other validation parameters obtained by high-performance liquid chromatography with tandem mass spectrometry (LC/MS/MS) analyzing milk samples were at the required levels for the analysis. Also, cow raw milk instances were taken from farms in Ankara province and were analyzed by LC/MS/MS. End of the sample analyses, NFs were not found in cow raw milk instances. In conclusion, NF metabolites were good determined in milk by LC/MS/MS and milk offered for consumption does not pose a risk to consumer health for NFs.

A new series of transition metal complexes of Cu(II), Ni(II), Co(II) and Fe(III) have been synthesized from the Schiff base (L1) and (L2) derived from Semicarbazide hydro chloride and 4-chlorobenzaldehyde or 4-bromobenzaldehyde. The structural features have been arrived from their elemental analyses, magnetic susceptibility, molar conductivity, IR, UV-Vis. and 1H NMR spectral studies. The data show that the complexes have composition of [M(L)2](NO3)2 and [Fe(L)2 (NO3)2](NO3) where the M=Co(II),Ni(II) and Cu(II) ;L=L1and L2 type. The magnetic susceptibility and UV-Vis spectral data of the complexes suggest a square planer geometry for Co(II) and Cu(II) but Fe(III) octahedral geometry and Ni(II) tetrahedral geometry around the central metal ion.Hyper Chem-6 program has been used to predict structure geometries of compounds in gas phase .The electrostatic potential of the free ligands were calculated to investigate the reactive sites of the molecules .The heat of formation(?Hf ?) and binding energy(?Eb) at 298K for the free ligands and its metal complexes were calculated by using PM3 method.

Certified reference materials (CRMs) contribute to the traceability of measurement results to recognized anchor points, ideally to the International System of Units (SI), and consequently, to their comparability and reliability. In the area of veterinary drugs' residues in foods of animal origin, the important role of CRMs must be highlighted, given the problems caused by trade restrictions in some countries. The results of studies concerning the certification of an incurred matrix certified reference material (IMCRM) for the mass fraction of nitrofuran metabolites in chicken muscles are presented in this work. A batch of IMCRM candidates was produced from chicken muscle samples containing the metabolites 3-amino-2-oxazolidinone (AOZ), 3-amino-5-morpholinomethyl-2-oxazolidinone (AMOZ), semicarbazide (SEM), and 1-aminohydantoin (AHD). All the statistical approaches for the homogeneity and stability assessments were based on the principles contained within ISO Guide 35 (current ISO 33405:2024). All the quantitative analyses of the nitrofuran metabolites were performed by means of high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The properties studied were sufficiently homogeneous and stable at -20°C for 360days (the defined storage conditions). Under transport conditions, the AOZ metabolite showed instability at 50°C. The residual moisture content was also monitored and showed instability at 20°C and 50°C. The characterization was performed via an exact matching calibration approach and the assigned values with their respective expanded uncertainties (k = 2) were 5.40 ± 1.2ngg-1, 5.49 ± 0.85ngg-1, 5.08 ± 1.2ngg-1, and 6.01 ± 0.85ngg-1 for the metabolites AOZ, AMOZ, AHD, and SEM, respectively, in the lyophilized chicken muscle. These values ranged from 1.3 to 1.5ngg-1 on a wet basis. The expiration date for the CRM was estimated based on the stated limits for future values calculated from the confidence interval of the stability study's linear regression curve.

Semicarbazide (SEM) is commonly utilized as a biomarker for detecting the usage of nitrofurazone (NFZ); however, its endogenous presence in aquatic products complicates detection and poses challenges to the quality and safety of these products. Although previous research suggests a potential link between SEM and urea, the specific mechanisms underlying its production under induced conditions remain unclear. To solve the above problem, the integrated metabolomic and transcriptomic analyses were performed for systematically exploring endogenous production mechanisms underlying SEM in Macrobrachium rosenbergii under urea conditions. As a result, urea exposure significantly disrupted key pathways, including glycine, serine, and threonine metabolism; 2-oxocarboxylic acid metabolism; and protein digestion and absorption, thereby highlighting the role of amino acid metabolism in SEM formation. Compared to traditional single-omics approaches, this method provided a comprehensive analysis of gene–metabolite interactions, revealing the mechanism of endogenous production of SEM in M. rosenbergii. This research offers new insights into enhancing aquatic product safety and quality and represents a methodological reference for future research regarding the endogenous SEM production mechanisms.

Design and synthesis of a novel pyrazole-based molecule with potential anticancer and antimicrobial effects: A multifaceted in silico approach