Reaction Sequence Research Articles

Construction of Spatially Separated Acid-Base Sites inside and outside Metal-Organic Framework Nanocrystals for Efficient Cascade Reactions.

The development of acid-base catalysts for one-pot cascade reactions remains challenging because of the inherent incompatibility of inorganic acid and base active sites. Here, we introduced an innovative approach that employs spatial separation to construct separated inorganic acid-base sites, achieving sequence control of acid-base cascade reactions. The as-prepared bifunctional catalyst applied metal-organic framework (MOF) nanocrystals as spatial separators, with the inside microcavities loaded with 1 nm inorganic polyoxometalate acid H3PMo12O40 clusters (NENU-5) and the outside crystal surface covered with basic CuCo layered double hydroxide (CuCo-LDH) nanosheets. By applying the resultant NENU-5@CuCo-LDH catalyst to cascade deacetalization-Knoevenagel condensation, over 99% of the benzaldehyde dimethyl acetal (BDMA) was transformed into the final benzylidene cyanoacetate (BCA) with a 99% yield at 80 °C and solvent-free conditions. Compared to the random NENU-5+CuCo-LDH, the NENU-5@CuCo-LDH with spatially separated acid-base sites indicated a higher reaction rate due to the designed reaction sequence and the shorter mass transfer pathway. Moreover, this hierarchical structure showed inherent shape selectivity and extraordinary stability. This study introduces spatial separation to address the incompatibility issue between inorganic acid and base active sites, offering novel perspectives for acid-base systems.

Parallel molecular data storage by printing epigenetic bits on DNA

DNA storage has shown potential to transcend current silicon-based data storage technologies in storage density, longevity and energy consumption1–3. However, writing large-scale data directly into DNA sequences by de novo synthesis remains uneconomical in time and cost4. We present an alternative, parallel strategy that enables the writing of arbitrary data on DNA using premade nucleic acids. Through self-assembly guided enzymatic methylation, epigenetic modifications, as information bits, can be introduced precisely onto universal DNA templates to enact molecular movable-type printing. By programming with a finite set of 700 DNA movable types and five templates, we achieved the synthesis-free writing of approximately 275,000 bits on an automated platform with 350 bits written per reaction. The data encoded in complex epigenetic patterns were retrieved high-throughput by nanopore sequencing, and algorithms were developed to finely resolve 240 modification patterns per sequencing reaction. With the epigenetic information bits framework, distributed and bespoke DNA storage was implemented by 60 volunteers lacking professional biolab experience. Our framework presents a new modality of DNA data storage that is parallel, programmable, stable and scalable. Such an unconventional modality opens up avenues towards practical data storage and dual-mode data functions in biomolecular systems.

Pyrolysis models for pressure treated wood and wood–plastic composite

AbstractPressure treated wood (PTW) and wood–plastic composites such as Trex® are popular materials for the construction of decks and other auxiliary structures, which are known to significantly contribute to spread of wildland fires into communities. In this work, representative samples of these materials were studied to determine their pyrolysis and combustion properties to enable simulation of fire growth on the surface of these building products. The pyrolysis property development process followed a well‐established hierarchical approach where thermogravimetric analysis, differential scanning calorimetry, and microscale combustion calorimetry were used to parametrize kinetics and thermodynamics of the thermal decomposition and combustion, while controlled atmosphere pyrolysis and cone calorimetry tests performed on coupon‐sized samples were used to parameterize thermal transport properties and validate performance of the fully parametrized pyrolysis models. PTW decomposition was captured using four sequential reactions with one additional reaction used to model vaporization of water. Trex® board was found to consist of two distinct layers: a thin outer layer and an internal core. The pyrolysis model for this material was constructed using some known properties of high‐density polyethylene (PE) and the properties of PTW determined in this work. The outer layer was defined in the model to consist of PE and an inert additive, while the core was defined as a blend of PE and wood particles, which kinetics and thermodynamics of the thermal decomposition and combustion were successfully captured using the model developed for PTW.

Total biosynthesis of the medicinal triterpenoid saponin astragalosides.

Astragalus membranaceus has been used in traditional Chinese medicine for over 2,000 years. Its major active triterpenoid saponins, astragalosides, have attracted great attention due to their multiple health benefits and applications in medicine. Despite this, the biosynthetic machinery for astragalosides remains enigmatic. Here a chromosome-level genome assembly of A. membranaceus was generated. The identification of two tailoring enzymes required for astragaloside biosynthesis enabled the discovery of a triterpenoid biosynthetic gene cluster, leading to elucidation of the complete astragaloside biosynthetic pathway. This pathway is characterized by a sequence of selective hydroxylation, epoxidation and glycosylation reactions, which are mediated by three cytochrome P450s, one 2-oxoglutarate-dependent dioxygenase and two glycosyltransferases. Reconstitution of this biosynthetic machinery in Nicotiana benthamiana allowed for heterologous production of astragaloside IV. These findings build a solid foundation for addressing the sourcing issues associated with astragalosides and broaden our understanding of the diversity of terpene biosynthetic gene clusters.

Gut Microbiota and Metabolic Alterations Associated with Heart Failure and Coronary Artery Disease.

This study investigates the role of gut microbiota in cardiovascular diseases, with an additional focus on pro-atherogenic metabolites. We use advanced network analysis and machine learning techniques to identify key microbial features linked to coronary artery disease (CAD) and heart failure with reduced ejection fraction (HFrEF). This cross-sectional study included 189 participants divided into three groups: coronary artery disease (n = 93), heart failure with reduced ejection fraction (n = 43), and controls (n = 53). Assessments included physical exams, echocardiography, dietary surveys, blood analysis, and fecal analysis. Gut microbiota composition was analyzed using next-generation sequencing (NGS) and quantitative polymerase chain reaction (qPCR). Statistical analysis methods for testing hypotheses and correlations, alpha and beta-diversity analyses, co-occurrence networks, and machine learning were conducted using Python libraries or R packages with multiple comparisons corrected using the Benjamini-Hochberg procedure. Significant gut microbiota alterations were observed, with higher Bacillota/Bacteroidota ratios in CAD and HFrEF groups compared to controls (p < 0.001). Significant differences were observed in α-diversity indices (Pielou, Chao1, Faith) between disease groups and controls (p < 0.001). β-diversity analyses also revealed distinct microbial profiles (p = 0.0015). Interestingly, trimethylamine N-oxide (TMAO) levels were lower in CAD and HFrEF groups compared to controls (p < 0.05), while indoxyl sulfate (IS) levels were comparable between the study groups. Co-occurrence network analysis and machine learning identified key microbial features linked to these conditions, highlighting complex interactions within the gut microbiota associated with cardiovascular disease.

Warm growing season activates microbial nutrient cycling to promote fertilizer nitrogen uptake by maize

The influence of nitrogen (N) inputs on soil microbial communities and N uptake by plants is well-documented. Seasonal variations further impact these microbial communities and their nutrient-cycling functions, particularly within multiple cropping systems. Nevertheless, the combined effects of N fertilization and growing seasons on soil microbial communities and plant N uptake remain ambiguous, thereby constraining our comprehension of the optimal growing season for maximizing crop production. In this study, we employed 15N isotope labeling, high-throughput sequencing, and quantitative polymerase chain reaction (qPCR) techniques to investigate the effects of two distinct growing seasons on microbial communities and maize 15N uptake ratios (15NUR). Our results showed that the warm growing season (26.6 °C) increased microbial diversity, reduced network complexity but enhanced stability, decreased microbial associations, and increased modularization compared to the cool growing season (23.1 °C). Additionally, the warm growing season favored oligotrophic species and increased the abundance of microbial guilds and functional genes related to N, phosphorus, and sulfur cycling. Furthermore, alterations in the characteristics of soil microbial keystone taxa were closely linked to variations in maize 15NUR. Overall, our findings demonstrate significant seasonal variations in soil microbial diversity and functioning, with maize exhibiting higher 15NUR during the warm growing season of the double cropping system.

Potential role of heteroplasmic mitochondrial DNA mutations in modulating the subtype-specific adaptation of oral squamous cell carcinoma to cisplatin therapy

Cancer cells are constantly evolving to adapt to environmental changes, particularly during exposure to drug treatment. In this work, we aimed to characterize genetic and epigenetic changes in mitochondrial DNA (mtDNA) that may increase the resistance of oral squamous cell carcinoma (OSCC) to cisplatin. We first derived drug-resistant cells from two human OSCC cell lines, namely SAS and H103, by continual cisplatin treatments for about 4 months. To determine mtDNA changes induced by cisplatin, we performed nanopore sequencing and quantitative polymerase chain reaction analysis of mtDNA extracted from the cells pre- and post-treatment. We also assessed the mitochondrial functions of the cells and their capacity to generate intracellular reactive oxygen species (ROS). We found that in the cisplatin-resistant cells derived from SAS, there was a reduction in mtDNA content and significant enrichment of a m.3910G > C mutation in the MT-ND1 gene. However, such changes were not detected in cisplatin-resistant H103 cells. The cisplatin treatment also altered methylation patterns in both SAS and H103 cells and decreased their sensitivity to ROS-induced cytotoxicity. We suggest that the sequence alterations and epigenetic changes in mtDNA and the reduction in mtDNA content could be key drivers of cisplatin resistance in OSCC. These mtDNA alterations may participate in cellular adaptation that serves as a response to adverse changes in the environment, particularly exposure to cytotoxic agents. Importantly, the observed mtDNA changes may be influenced by the distinct genetic landscapes of various cancer subtypes. Overall, this study reveals significant insights into cisplatin resistance driven by complex mtDNA dynamics, particularly in OSCC. This underscores the need for targeted therapies tailored to the genetic profiles of individual OSCC patients to improve disease prognosis.

Study of the relationships among known virulence genes, coccoid transformation and cytotoxicity of Helicobacter pylori in different clinical diseases

ABSTRACT Background Helicobacter pylori (H. pylori) has infected approximately 4.4 billion individuals worldwide. The known virulence genes and the existing H. pylori typing methods have not been shown to have a recognized correlation with its infectivity. The aim of this study was to elucidate the relationships among known important virulence genes, coccoid transformation, and cytotoxicity of H. pylori isolated from individuals with different clinical diseases to provide guidance for the development of new virulence typing methods for H. pylori. Methods The known important virulence genes of 35 H. pylori strains were identified by whole-gene next-generation sequencing (WGS) and polymerase chain reaction (PCR). The chronological changes in the proportion of coccoid forms of H. pylori and their ultramicroscopic structures were observed chronologically using transmission electron microscopy. Human gastric mucosal epithelial cells (GES-1) w Results There were no significant correlations among the known important virulence genes, coccoid transformation and cytotoxicity of H. pylori isolated from patients with different clinical diseases. We developed a new virulence classification based on the defensive and offensive abilities of H. pylori. Conclusions Coccoid transformation and virulence are two independent characteristics of H. pylori that reflect its defensive and offensive abilities, respectively. These two abilities work synergistically, warranting the construction of a new virulence typing method for H. pylori. However, the correlation between the new virulence classification and pathogenic ability still needs to be further ver

Air-stable palladium N[sbnd]Heterocyclic carbene based CCC[sbnd]NHC pincer complexes: Synthesis, characterization, photophysical and Raman vibrational studies, and DFT studies, plus observation of an abnormal carbene pincer

A series of CCCNHC pincer Pd(II)X complexes, where X = Cl, Br, or I, were synthesized by a metalation/transmetalation reaction sequence and characterized by NMR and Raman spectroscopy, photophysical studies, X-ray crystallography, and DFT computational studies. This is the first detailed report of the CCCNHC pincer Pd complexes analogous to the previously reported Pt analogs. Photophysical measurements show that by varying the X ligand, the emission wavelength can be tuned. The chloride complex is a water and air stable blue emitter with a quantum yield of 46 % and all three complexes have photostabilities >90 %. A combined DFT and TD-DFT study has been carried out to investigate ground state and excited state geometries as well as absorption and emission processes of CCCNHC Pd complexes. Theoretical results were compared with the corresponding experimental results and showed good agreement. Raman spectroscopy (computational and experimental) was used to examine Pd-X vibrations which have been rarely reported in the literature. Several by-products of the metalation/transmetalation procedure were identified. A rare mixed normal/abnormal carbene pincer Pd(II)Cl complex was isolated and crystallographically characterized.

Abiotic Acyl Transfer Cascades Driven by Aminoacyl Phosphate Esters and Self-Assembly.

Biochemical acyl transfer cascades, such as those initiated by the adenylation of carboxylic acids, are central to various biological processes, including protein synthesis and fatty acid metabolism. Designing cascade reactions in aqueous media remains challenging due to the need to control multiple, sequential reactions in a single pot and manage the stability of reactive intermediates. Herein, we developed abiotic cascades using aminoacyl phosphate esters, the synthetic counterparts of biological aminoacyl adenylates, to drive sequential chemical reactions and self-assembly in a single pot. We demonstrated that the structural elements of amino acid side chains (aromatic versus aliphatic) significantly influence the reactivity and half-lives of aminoacyl phosphate esters, ranging from hours to days. This behavior, in turn, affects the number of couplings we can achieve in the network and the self-assembly propensity of activated intermediate structures. The cascades are constructed using bifunctional peptide substrates featuring side chain nucleophiles. Specifically, aromatic amino acids facilitate the formation of transient thioesters, which preorganized into spherical aggregates and further couple into chimeric assemblies composed of esters and thioesters. In contrast, aliphatic amino acids, which lack the ability to form such structures, predominantly undergo hydrolysis, bypassing further transformations after thioester formation. Additionally, in mixtures containing multiple aminoacyl phosphate esters and peptide substrates, we achieved selective product formation by following a distinct pathway that favors subsequent reactions through reactivity changes and self-assembly. By coupling chemical reactions with molecules of varying reactivity time scales, we can drive multiple reaction clocks with distinct lifetimes and self-assembly dynamics, facilitating precise temporal and structural regulation.

AML typical mutations (CEBPA, FLT3, NPM1) identify a high-risk chronic myelomonocytic leukemia independent of CPSS molecular

AbstractMutations commonly associated with acute myeloid leukemia (AML), such as CEBPA, FLT3, IDH1/2, and NPM1, are rarely found in chronic myelomonocytic leukemia (CMML), and their prognostic significance in CMML has not been clearly identified. In 127 patients with CMML, we have retrospectively analyzed next-generation sequencing and polymerase chain reaction data from bone marrow samples collected at the time of CMML diagnosis. Seven patients harbored CEBPA mutations, 8 FLT3 mutations, 12 IDH1 mutations, 26 IDH2 mutations, and 11 NPM1 mutations. Patients with CMML harboring CEBPA, FLT3, and/or NPM1 mutations (mutCFN) more frequently had the myeloproliferative subtype, a high prevalence of severe cytopenia, and elevated blast counts. Regardless of their CMML Prognostic Scoring System molecular classification, mutCFN patients with CMML had a poor prognosis, and the multivariate analysis identified mutCFN as an independent marker of overall survival. The genetic profile of these mutCFN patients with CMML closely resembled that of patients with AML, with higher-risk clinical characteristics. Our findings lead us to suggest including the assessment of these mutations in CMML prognostic models and treating these patients with AML-type therapies, including intensive chemotherapy and allogeneic stem cell transplantation, whenever feasible. Furthermore, certain targeted therapies approved for use in AML should be considered.

SNaPshot minisequencing for SARS CoV 2 Variant Genotyping

Abstract Introduction/Objective The SNaPshot Multiplex System (Thermo Fisher) can investigate up to fifty SNP markers simultaneously by using PCR amplification and subsequent dideoxy single base extension of an unlabeled primer and capillary electrophoresis. After electrophoresis and fluorescence detection, the alleles of a single marker appear as different colored peaks at roughly the same size in the electropherogram plot. The size of the different allele peaks vary slightly due to differences in molecular weight of the dyes. We propose a new set of primers and probes to use this system to differentiate variants of SARs Cov 2 variants. Methods/Case Report SNAPSHOT analysis was performed using the primers designed internally and analysis was done of up to 7 mutation hot spots, which were 417, 4511, 478, 484, 501, 614, and 681. By implementing the algorithm of systems and methods herein with the traces depicted in Figures, true positive and true negative outcomes for the different COVID variants can be performed, based on the highlighted peaks, which are not necessarily the most intense peaks. 10 Positive controls achieved from in stro transcript plasmid was tested then 10 viral RNA obtained through BEI Resources, NIAID was tested after mixed into 30 pooled negative PCR-swab specimens. Genmapper was used for analysis of results. 40 Korean patient samples were tested as well. Results (if a Case Study enter NA) Both In vitro transcript and derived specimens of wild type, alpha, beta, delta, gamma, kappa, omicron, and pirola showed expected results in 78/80 of the specimens. For example,delta B.1.617.2 variant showed 1 = A (green) at Primer 452R-F, 2 = G (blue): Primer 484Q-F, and 3 = A (green) at Primer 614-F. Of note, hetero type was noted in a few of the patient strains but none of the BEI strains and this may be due to a transfromation of the virus and worth investigation. Conclusion The SNaPshot® Multiplex System is a accurate system that may be applied to multiple applications including viral strain anylsis and here we can show how it may be effectively used for SARS-Cov-2 gentotyping. Using this technique, it is possible to analyze more than 50 SNPs distributed throughout the genome in a single multiplex reaction, making it an advantage when compared with traditional sequencing reaction. This is a important study that shows that this technique may be used in multiple field applictions.

Dual Redox Reactions of Silver Hexacyanoferrate Prussian Blue Analogue Enable Superior Electrochemical Performance for Zinc-ion Storage.

Prussian blue analogues (PBAs) have been employed as host materials of aqueous zinc-ion batteries (ZIBs), however, they suffer from low capacity and poor cycling stability due to limited electron transfer and the presence of interstitial water in PBAs. Herein, a vacancy and water-free silver hexacyanoferrate K0.95Ag3.05Fe(CN)6 (AgHCF-3) was synthesized by adjusting the ratio of K and Ag in the framework. It offers nearly four electrons involving two sequential redox reactions, namely, Fe3+/Fe2+ and Ag+/Ag0, to deliver a large capacity of 179.6 mAh g-1 at 20 mA g-1 with Coulomb efficiency of ~100%. The Zn//AgHCF-3 cell delivers an estimated energy density of 200 Wh kg-1, surpassing reported PBAs-based ZIBs. The formation of Ag0 in the cycling process merits favorable rate performance of AgHCF-3 (156.4 mAh g-1 at 200 mA g-1 with 80.3% capacity retention after 100 cycles). This investigation paves new pathways for high-capacity PBA cathodes.

Association Between the Risk of Dental Caries and DLX3 Gene Polymorphisms in Chinese Children.

To explore the association between the risk of dental caries and distal-less homeobox 3 (DLX3) gene in Chinese children. Based on the decayed, missing, and filled teeth (dmft) score, the children were divided into a control group (dmft &#61; 0) and a case group (dmft ≥ 1). DLX3 gene (rs11656951 and rs2278163) polymorphisms were genotyped by polymerase chain reaction (PCR) and Sanger sequencing methods. Possible association of DLX3 gene (rs11656951 and rs2278163) polymorphisms with dental caries risk was assessed using the chi-squared test. Subgroup analysis of association was assessed by logistic regression analysis for the potential risk factors. The age at which toothbrushing was started, the brushing frequency, brushing with fluoride toothpaste, and regular dental visits were statistically significantly different between case and control groups (p 0.05). The frequencies of rs11656951 TT genotype and T allele were statistically significantly higher in the control group than in the case group. The chi-squared test showed that CT genotype (p &#61; 0.026, OR &#61; 0.613, 95%CI &#61; 0.398-0.944) and TT genotype (p &#61; 0.001, OR &#61; 0.378, 95%CI &#61; 0.212-0.673) were negatively correlated with caries susceptibility. The T allele of rs11656951 was more frequently discovered in the control group, and was statistically significantly associated with decreased caries susceptibility (p &#61; 0.001, OR &#61; 0.636, 95%CI &#61; 0.486-0.831). The G allele of rs2278163 was obviously correlated with elevated caries susceptibility (p &#61; 0.049, OR &#61; 1.314, 95%CI &#61; 1.000-1.725). DLX3 gene rs11656951 TT genotype was a protective factor for caries susceptibility in the subgroups gender, sweets intake, eating before sleep, brushing frequency, brushing with fluoride toothpaste, and dental visits. The GG genotype of rs2278163 was a risk factor for caries in subgroups eating before sleep, brushing without fluoride toothpaste, and regular dental. The TT genotype of rs11656951 was dramatically correlated with reduced caries risk in low (p &#61; 0.004, OR &#61; 0.387, 95%CI &#61; 0.202-0.742) and moderate/high (p &#61; 0.016, OR &#61; 0.360, 95%CI &#61; 0.154-0.840) groups. DLX3 gene rs11656951 TT genotype is a protective factor and rs2278163 GG genotype is a risk factor for caries susceptibility, especially in low and moderate/high subgroups.

Diagnostic potential of miRNA-135A1 in human papillomavirus associated cervical lesions

Introduction. Human papillomavirus (HPV) infection with high-risk HPVs is an etiological factor in the development of cervical cancer, with HPV type 16 (HPV16) being the most common. The mechanisms leading to disruption of viral oncogene expression and initiation of epithelial cell transformation are poorly understood. Epigenetic regulatory factors, including cellular miRNAs, may play an important role in HPV-induced carcinogenesis, and aberrantly expressed miRNAs may be promising markers for the diagnosis of HPV-associated lesions.Aim. To search for miRNAs involved in the pathogenesis of HPV16-associated cervical cancer and to evaluate their diagnostic potential for the detection of cervical cancer and precancerous lesions.Materials and methods. MiRNA expression in clinical samples was assessed by both next generation sequencing and quantitative stem-loop polymerase chain reaction (sl-qPCR). Plasma miRNAs from patients with precancerous and cancerous lesions and healthy donors were analyzed using sl-qPCR. Loss of heterozygosity in cervical cancer samples was assessed by copy number ratio of MIR135A1 and ACTB genes. A total of 67 patients with cervical cancer, 21 with precancerous cervical lesions and 24 healthy donors were included in the study. The effect of DNA methylation on miRNA-135A1 expression was evaluated after treatment with a demethylating agent of the cervical HPV16-positive SiHa cell line. Changes in the expression of the HPV16 E6 oncogene were analyzed after transfection with synthetic analogues of the mature forms of miRNA-135А1 (miRNA-135a-3p and miRNA-135a-5p).Results. A significant decrease in the expression of miRNA-135A1 and miRNA-135A2 was detected in tumor tissue samples from HPV16-positive cervical cancer, which was confirmed by sl-qPCR in an independent panel of tumor samples. A decrease in miRNA-135A1 expression was shown to result from both loss of heterozygosity of the gene and aberrant DNA methylation. Transfection of mature forms of miRNA-135A1 into SiHa cells resulted in decreased expression of the E6 oncogene of HPV16. Blood plasma samples from patients with cervical cancer and precancerous lesions showed lower levels of miRNA-135a-3p than healthy donors, and ROC analysis indicated its high diagnostic potential.Conclusion. Levels of miRNA-135A1 are significantly reduced in cervical lesions, both in tumor tissue and plasma, and the ability of this miRNA to suppress the expression of the HPV16 E6 oncogene suggests its oncosuppressive properties. Thus, miRNA-135A1 can be used as a promising new marker for the diagnosis of HPV-associated lesions.

Optimizing propylene production via acetone hydrodeoxygenation: Insights from catalytic studies with Cu/γ-Al2O3 and Hβ zeolite

Propylene is a crucial light olefin in the petrochemical industry and can be produced via acetone hydrodeoxygenation, which involves two sequential reactions: first, acetone undergoes hydrogenation catalyzed by metallic sites, followed by the dehydration of the resulting isopropanol catalyzed by acidic sites. In this study, propylene production through acetone hydrodeoxygenation was investigated using a physical mixture of 35 wt% Cu/γ-Al2O3 and Hβ zeolite to investigate how various reaction parameters affect acetone conversion and propylene yield. Using the experimental design methodology, empirical models were developed to correlate acetone conversion (Xacet) and propylene yield (Yprop) with the ratio of 35 wt% Cu/γ-Al2O3 to Hβ (CR), total catalyst weight (Cw), hydrogen volumetric flow rate (FH2) and reaction temperature (T). The maximum propylene yield achieved in the catalytic tests was 73.46 %. A long-term test demonstrated the catalyst's reusability, remaining active even after 22 hours of reaction with only a slight decrease in propylene yield. Analysis of the experimental data revealed that increasing T and Cw positively affected propylene yield, whereas higher CR and FH2 had negative effects. According to the Pareto chart, reaction temperature was the most influential variable for propylene yield, followed by CR, FH2 and Cw. For acetone conversion, the order of significance among the variables was T >CR >Cw >FH2.

Catalytic hydrodehalogenation of iodinated contrast agents in drinking water: A kinetic study

The occurrence of iodinated contrast media (ICM) in water bodies represents a significant threat for public health due to their strong biochemical stability and recalcitrance to conventional water treatment systems. In this work, the feasibility of catalytic hydrodehalogenation (HDH) for the degradation of a representative group of ICMs (iohexol (IHX), iopromide (IPR), iopamidol (IPM) and diatrizoic acid (DIA)) is investigated. Complete degradation and deiodination of the isolated ICMs (1.6·10−2 mmol L−1) was achieved in less than 30 min in the presence of 0.25 g L−1 of different precious metal catalysts (Pd/Al2O3, Rh/Al2O3 and Pt/Al2O3) under ambient conditions, closing iodine balance by >95 %. Based on the identified reaction intermediates and final products, reaction mechanisms were accordingly proposed. A sequential reaction pathway was proposed for DIA removal, while reaction mechanisms encompassing both sequential and concerted reaction steps were proposed for the non-ionic ICMs (IHX, IPR, and IPM). Subsequent kinetic models, which successfully described experimental data, were developed from the elucidated reaction mechanisms, considering all species involved in the reaction. The versatility of the process was finally demonstrated in the treatment of real aqueous matrices (surface water and tap water) spiked with the ICMs mixture, except in the case of Pt/Al2O3 which suffered deactivation due to surface poisoning by halides. For this catalyst, kinetic constants ranged from 0.31 to 0.22 min−1 in deionized water, and from 0.04 to 0.08 min−1 in surface water as the reaction matrix. Among the tested catalysts, Pd/Al2O3 showed the highest activity and stability for the removal of ICMs.

Electrochemical C-O and C-N Arylation using Alternating Polarity in flow for Compound Libraries.

Etherification and amination of aryl halide scaffolds are commonly used reactions in parallel medicinal chemistry to rapidly scan structure-activity relationships with abundant building blocks. Electrochemical methods for aryl etherification and amination demonstrate broad functional group tolerance and extended nucleophile scope compared to traditional methods. Nevertheless, there is a need for robust and scale-transferable workflows for electrochemical compound library synthesis. Herein we describe a platform for automated electrochemical synthesis of C-X arylation (X=NH, OH) in flow to access compound libraries. A comprehensive Design of Experiment (DoE) study identifies an optimal protocol which generates high yields across>30 aryl halide scaffolds, diverse amines (including electron-deficient sulfonamides, sulfoximines, amides, and anilines) and alcohols (including serine residues within peptides). Reaction sequences are automated on commercially available equipment to generate libraries of anilines and aryl ethers. The unprecedented application of potentiostatic alternating polarity in flow is essential to avoid accumulating electrode passivation. Moreover, it enables reactions to be performed in air, without supporting electrolyte and with high reproducibility over consecutive runs. Our method represents a powerful means to rapidly generate nucleophile independent C-X arylation compound libraries using flow electrochemistry.

Innovations in cancer diagnosis and treatment: prospects and challenges

The research relevance of cancer diagnostics and treatment is determined by its widespread occurrence and the lack of adequate modern diagnostic methods. The study aims to characterise new diagnostic methods, namely screenings in detecting cancer at early stages of development. To achieve this goal, the bibliosemantic and bibliographic methods were used. Main results. Cancer is the leading cause of morbidity and mortality after cardiovascular diseases and injuries in many countries around the world. Various diagnostic and treatment methods are used to combat this problem, including computed tomography, magnetic resonance imaging and positron emission tomography. In addition, modern diagnostic methods such as polymerase chain reaction, mass spectrometry and genomic sequencing play an important role in determining the types of cancer cells and their sensitivity to treatment. These advanced methods can be used to diagnose cancer more accurately and efficiently and choose the most appropriate treatment strategies for each patient. The practical significance of this topic is to ensure appropriate care for patients with cancer: providing high-quality, efficient, fast and minimally invasive diagnostics using the latest methods, as well as implementing a screening system.

The first report of prion protein gene sequences in Dybowski’s frog and the American bullfrog: high amyloid propensity of the frog prion protein

Prion diseases are fatal infectious neurodegenerative diseases caused by the proteinase K-sensitive form of prion protein (PrPSc). The exact origin of prion seeding and the transition factor of PrPSc has not been elucidated. The main hosts of prion diseases are herbivores, so the feces and corpses of Amphibians can seed PrPSc through ecosystems. The frog is an excellent candidate for transmission studies for this reason, but genetic analyses of the prion protein gene (PRNP) in the context of prion-related characteristics of frog species are lacking. We amplified frog PRNP gene sequences in Dybowski’s frog and the American bullfrog by polymerase chain reaction (PCR) and amplicon sequencing. In addition, we carried out multiple sequencing alignments and annotated major PrP components including signal peptide, tandem repeat domain, and PrPC-PrPSc interaction region of frog PrPs by bioinformatics tools. We predicted secondary and tertiary structures and amyloid propensities of frog PrPs using AlphaFold2 and AMYCO, respectively. We obtained DNA sequences of the PRNP gene in Dybowski’s frog and the American bullfrog, as well as a partially conserved palindromic sequence (PrPC-PrPSc interaction region) and absence of tandem repeat region of PrP in seven frog species. We analyzed protein structure of among these frog species and found that the high Himalaya frog has high aggregation propensity and the western clawed frog does not have the N-terminal signal peptide. To the best of our knowledge, this was the first comparative genetic study regarding prion-related features of frog species.