Method For Synthesis Research Articles

DNA-Based Conductors: From Materials Design to Ultra-Scaled Electronics.

Photolithography has been the foundational fabrication paradigm in current high-performance electronics. However, due to the limitation in fabrication resolution, scaling beyond a 20-nm critical dimension for metal conductors presents a significant challenge for photolithography. Structural DNA nanotechnology emerges as a promising alternative to photolithography, allowing for the site-specific assembly of nano-materials at single-molecule resolution. Substantial progresses have been achieved in the ultra-scaled DNA-based conductors, exhibiting novel transport characteristics and small critical dimensions. This review highlights the structure-transport property relationship for various DNA-based conductors and their potential applications in quantum/semiconductor electronics, going beyond the conventional scope focusing mainly on the shape diversity of DNA-templated metals. Different material synthesis methods and their morphological impacts on the conductivities are discussed in detail, with particular emphasis on the conducting mechanisms, such as insulating, metallic conducting, quantum tunneling, and superconducting. Furthermore, the ionic gating effect of self-assembled DNA structures in electrolyte solutions is examined. This review also suggests potential solutions to address current challenges in DNA-based conductors, encouraging multi-disciplinary collaborations for the future development of this exciting area.

Facile and rapid colorimetric detection of carbaryl using nitrite-conjugated gold nanoparticles to ensure environmental and consumer safety

From the use of pesticides in agriculture, carbaryl, the main component of pesticides, has permeated the ecosystem, causing various side effects such as weakness and neurodegenerative diseases in organisms. For this reason, a convenient sensor that can be used for facile carbaryl detection is necessary. Herein, we design a facile, simple, and rapid synthesis method using nitrite receptor-conjugated gold nanoparticles (AuNPs@NO2) as a probe for colorimetric detection. This sensor provided a limit of 2 μM of carbaryl detection when observed with the naked eye, which is lower than those obtained with conventional sensors. Selective tests demonstrated that the nitrite receptor specifically interacted with carbaryl compared with other chemical compounds. Importantly, by introducing the stabilizing agent polyvinylpyrrolidone on the surface of the AuNPs@NO2, selective detection of carbaryl was also feasible in various real-world soil, crop, water, and cosmetic product samples. Recovery rates within the range of 83.33 ± 3.86–107.0 ± 3.24 % showed the operability of this sensor for diverse real samples. Using an easily synthesized colorimetric sensor, this study provides valuable insights into the simple and rapid detection of carbaryl in various areas, including ecosystems and human daily life.

Factors influencing multiple non-utilized healthcare appointments from patients' and healthcare providers' perspectives: a qualitative systematic review of the global literature.

The term "non-utilised appointments" emerged in 2019 but lacks a clear definition. We focus on multiple non-utilised appointments due to recent advances in understanding 'missingness' in UK healthcare. Studies on missed appointments show conflicting results regarding interventions like text messaging due to oversight of occasional versus repeated missed appointments. Understanding patient and healthcare-related factors in multiple non-utilised appointments is crucial for improving interventions and patient engagement. To identify factors influencing multiple non-utilised appointments from patients' and healthcare providers' perspectives. A systematic review of qualitative research identifying factors that influence multiple non-utilised appointments across diverse global health care settings. The review employed a qualitative systematic approach, encompassing diverse papers from multiple databases, irrespective of patient or healthcare provider age, location, or setting. Data analysis followed Thomas and Harden's thematic synthesis method. Themes are presented in alignment with both the health service and patient perspective aspects of the Levesque access model. Ten thousand and eighty-six records were retrieved. Five studies met the inclusion criteria and were analysed. Six key themes influenced appointment utilisation. Healthcare system determinants highlighted provider-patient relationship and professionalism, and healthcare organisation factors role in appointments utilisation. Patient experience and decision-making explored personal factors. Additionally, communication, support, and engagement delved into challenges with communication and language, family and social support, and socio-familial barriers to appointment utilisation. Health and well-being factors encompassed medical conditions, mental and emotional factors, and psychosocial determinants affecting appointment utilisation. Moreover, financial constraints and socioeconomic factors were identified as significant contributors. Lastly, healthcare access and barriers addressed transportation challenges, accessibility issues, and geographical barriers impacting healthcare access. The analysis reveals complex factors influencing multiple non-utilised appointments. Strong provider-patient relationships improve care accessibility. Flexible scheduling and patient-centred approaches are pivotal, alongside addressing workplace discrimination. Tailored healthcare services and overcoming geographical barriers are essential. Ensuring safety, accessibility, and communication, while supporting vulnerable groups and mental health needs, are necessary. Equitable access to services and alternative transportation solutions are essential for comprehensive healthcare delivery. PROSPERO CRD42023429465.

One‐Pot Synthesis of Gold Nanoparticles and Aluminum Hydroxide Hydrogels‐Based Nanocomposites with Modulated Optical Properties

AbstractIn this work, the one‐pot synthesis of composites constituted by gold nanoparticles (AuNPs) and aluminum hydroxide hydrogels (AlHG) by employing the Epoxide Route is presented. To modulate the optical properties of the final composites, different anions (X= , , and ) were used as nucleophile, complexing and growth directing agents of the AuNPs. In addition, the concentration of the reactants, e. g., the X : Cl ratio, was set in such a way to preserve the alkalization rate, the transparency of the hydrogels supporting the AuNPs, and the stability of the final composites. Consequently, the composites exhibit different plasmonic properties, resulting from the AuNPs with different sizes and morphologies, as confirmed through transmission electron microscopy, depending on the nature of the employed anion, exclusively. Furthermore, this versatile one‐pot synthesis strategy was employed to design new composites with different I : Cl ratio and synthesize stable colloidal AuNPs within an aluminum hydroxide sol (AuNP@Alsol) without adding any conventional capping agent. This AuNP@Alsol composite can be used as seed to accelerate the extremely slow AuNPs formation kinetics in AuNP@AlHG(SCN), demonstrating the potential of this synthesis method to create composites susceptible to be applied in the photonic and catalysis areas.

A mini‐review of intensified synthesis of 1st and 2nd generation biofuels in the presence of perovskite catalysts

AbstractEnhancement of a sustainable environment through the choice of a selective catalyst with high activity, regeneration nature, and high stability is an important aspect to be focused on to achieve a high yield and maximum conversion of feedstock to biodiesel (1st generation biofuel), and also in the biomass valorization/pyrolysis (2nd generation biofuel synthesis). Depending on the nature of the catalyst and synthesis method adopted for biofuel production and biomass valorization, the variations in the process conditions, final yield, and conversion are varied accordingly. A prospective development and application of perovskite catalysts in the synthesis of 1st and 2nd generation biofuels using various process intensification strategies for the development of a clean and green environment is reviewed in this study. The synthesis of types of perovskite catalysts polycrystalline, nano‐sized, and powdered oxide are also discussed in this review. It is also concluded that, apart from other process parameters, molar ratio is one of the most influencing sensitive factors in the case of 1st generation biofuel synthesis, whereas during the production of 2nd generation biofuels, catalyst concentration and liquid–solid ratio are more significant process parameters that change based on the nature of the catalyst selected for the reaction.

High performance oxygen reduction and evolution reactions by graphitization of nickel –cobalt framework system

This study presents the successful synthesis of metal-organic frameworks (MOFs) via a simple one-pot method, followed by pyrolysis at 1000 °C to be used in the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). A study utilizing various techniques, including field emission scanning electron microscopy (FESEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), investigated the properties of NiCo-MOF and its individual components before and after pyrolysis.The pristine MOFs exhibited limited electrochemical stability for both ORR and OER, while the pyrolyzed MOFs demonstrated a significant enhancement and excellent long-term stability in OER and ORR performance in alkaline media. Notably, the OER performance rivaled that of the benchmark IrO2 electrocatalyst, with similar onset potentials (1.48 V for IrO2, 1.52 V, 1.56 V, and 1.59 V for pyrolyzed NiCo-MOF, Co-MOF, and Ni-MOF, respectively). Furthermore, the pyrolyzed MOF catalysts displayed promising ORR activity in a 0.1 M KOH solution under O2 saturation, as evidenced by their onset potentials (around 0.615 V, 0.63 V, and 0.7 V vs. RHE) and favorable Tafel slopes (53, 84, and 154 mV dec⁻1, for graphitizated Ni-MOF, Co-MOF, and NiCo-MOF, respectively). These findings demonstrate the effectiveness of pyrolysis in engineering the MOF crystal structure for enhanced catalytic performance. This paves the way for further exploration of this synthesis method for the design of structurally optimized catalysts and applicable to a broad spectrum of energy technologies.

Charge-Transfer Complexes: Fundamentals and Advances in Catalysis, Sensing, and Optoelectronic Applications.

Supramolecular assemblies, formed through electronic charge transfer between two or more entities, represent a rich class of compounds dubbed as charge-transfer complexes (CTCs). Their distinctive formation pathway, rooted in charge-transfer processes at the interface of CTC-forming components, results in the delocalization of electronic charge along molecular stacks, rendering CTCs intrinsic molecular conductors. Since the discovery of CTCs, intensive research has explored their unique properties including magnetism, conductivity, and superconductivity. Their more recently recognized semiconducting functionality has inspired recent developments in applications requiring organic semiconductors. In this context, CTCs offer a tuneable energy gap, unique charge-transport properties, tailorable physicochemical interactions, photoresponsiveness, and the potential for scalable manufacturing. Here, an updated viewpoint on CTCs is provided, presenting them as emerging organic semiconductors. To this end, their electronic and chemical properties alongside their synthesis methods are reviewed. The unique properties of CTCs that benefit various related applications in the realms of organic optoelectronics, catalysts, and gas sensors are discussed. Insights for future developments and existing limitations are described.

Enhanced electrochemical validation of metal organic frameworks-derived TiO2/Fe-TiO2 as an active electrode for supercapacitors

AbstractDeveloping supercapacitor materials that are both efficient and durable, with high cycle life and specific energy, poses a significant challenge due to issues in electrodes such as volume expansion and electrode degradation that occur over time. This work reports a simple, novel, and cost-effective synthesis method to fabricate high surface area “Iron (Fe) doped TiO2 materials” via the metal-organic framework (MOF) route for supercapacitor application. Morphological analysis revealed a disc-like shaped pattern for pristine TiO2 (PT), and a cuboid form for Fe-doped TiO2 (FeT). The electrochemical investigation of MOF-derived PT and FeT electrode materials demonstrated the superior performance of FeT. Cyclic Voltammetry revealed enhanced electrochemical properties in FeT. Galvanostatic charge-discharge measurements confirmed FeT’s higher energy storage capacity, reaching a maximum specific capacitance of 925 Fg− 1. Long-term cycling tests exhibited excellent stability, with FeT retaining 67% of its initial capacitance after 6000 cycles and showing prolonged self-discharge. Overall, the results underscore the potential of Fe-doped TiO2 for high-performance supercapacitors.

Green Synthesis of Copper Oxide Nanoparticles from Waste Solar Panels Using Piper nigrum Fruit Extract and Their Antibacterial Activity

To promote environmental development and sustain resource circularity, recycling metals from electronic waste is essential. Electronic waste is a significant secondary source of metals, with its production increasing rapidly and most remaining unrecycled. In solar panels, copper is the second-most-valuable metal after silver. We propose an innovative method to recycle copper from waste solar panels and convert it into copper oxide nanoparticles (CuONPs) using a green synthesis method. Synthesizing CuONPs is advantageous due to their large surface area compared to bulk material. Nitric acid, a strong oxidizing agent, was used to leach copper from solid copper wires in waste solar panels. A green synthesis method, following a bottom-up approach, was employed using Piper nigrum fruit extract to synthesize CuONPs. The synthesized nanoparticles were characterized using various qualitative and quantitative techniques. Spectroscopic analysis confirmed the formation of CuONPs, and transmission electron microscopy revealed that the nanoparticles were spherical with sizes up to 60 nm. Biomolecules from the Piper nigrum extract were detected on the surface of the crystalline CuONPs. These nanoparticles exhibited antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus using a well-diffusion method, showing a larger zone of inhibition for E. coli compared to S. aureus. This research demonstrates the complete recovery of copper from waste solar panels and its conversion into useful CuONPs, which have potential medicinal applications.

Creating a body of physical activity evidence to test the generalisation of annotation methods for automated evidence synthesis

Background The Human Behaviour-Change Project (HBCP) aims to improve evidence synthesis in behavioural science by compiling intervention reports, annotating them according to an ontology, and using the resulting data to train information extraction and prediction algorithms. The HBCP used smoking cessation as the first ‘proof of concept’ domain but intends to extend its methodology to other behaviours. The aims of this paper are to (i) assess the extent to which methods developed for annotating smoking cessation intervention reports were generalisable to a corpus of evidence relating to a different behaviour, namely physical activity, and (ii) describe the steps involved in developing this second HBCP corpus. Methods The development of the physical activity corpus took place in four stages: (i) reviewing the suitability of smoking cessation codes already used in the HBCP, (ii) defining the selection criteria and scope of the corpus, (iii) identifying and screening records for inclusion, and (iv) annotating intervention reports using a code set of 200+ entities from the Behaviour Change Intervention Ontology. Results Stage 1 highlighted the need to modify the smoking cessation behavioural outcome codes for application to physical activity. One hundred physical activity intervention reports were reviewed, and 11 physical activity experts were consulted to inform the adapted code set. Stage 2 involved narrowing down the scope of the corpus to interventions targeting moderate-to-vigorous physical activity. In stage 3, 111 physical activity intervention reports were identified, which were then annotated in stage 4. Conclusions Smoking cessation annotation methods developed as part of the HBCP were mostly transferable to the physical activity domain. However, the codes applied to behavioural outcome variables required adaptations. This paper can help anyone interested in building a body of research to develop automated evidence synthesis methods in physical activity or for other behaviours.

High-performance electrocatalyst for PEMFC cathode: Combination of ultra-small platinum nanoparticles and N-doped carbon support

To accelerate the implementation of zero-emission power installations based on proton-exchange membrane fuel cells, it is necessary to maximize the power characteristics of these devices. For this purpose, we have obtained and tested a new N-doped carbon support and a synthesized Pt/C catalyst based on it with a platinum loading of about 37.3 %. A comparison of the degradation resistance of the initial support and the N-doped one has shown greater stability of the latter. At the same time, Raman spectroscopy has confirmed the presence of the C–N bond, which indicates the successful doping of carbon with nitrogen. The resulting Pt/C catalyst based on an N-doped support is characterized by a substantially narrow size dispersion and an ultra-small nanoparticle size of about 2.6 nm. The high-angle annular dark-field scanning transmission electron microscopy images of the synthesized catalyst have confirmed the presence of individual platinum atoms/clusters uniformly distributed over the surface of the support, and their presence is due to nitrogen embedded into the carbon structure. This material is characterized by a 50 m2 gPt-1 larger electrochemically active surface area and a 227 A gPt-1 greater mass activity compared to the commercial JM40 analog (40 % platinum loading). Meanwhile, the electrochemical parameters remaining after the accelerated stress testing are almost 2 times higher than those of JM40. And the power characteristics in the membrane electrode assembly for the catalyst synthesized by the facile one-pot synthesis method are 13 % (575 mW cm-2) higher than those of the commercial analog (500 mW cm-2). The Pt/C catalyst obtained during the research is deemed promising for commercial use in proton-exchange membrane fuel cells.

Green synthesis of nanostructured 1T/2H-MoS2 hybrid phase with polyol solvents and microwave heating

Green synthesis approaches have attracted greatly of attention in recent years since they address the issues associated with sustainability than conventional synthesis methods. New research fields in green nanoscience are being developed as a result of the incorporation of green chemistry principles into nanoscience. In this paper, the successful microwave-assisted green synthesis of MoS2 nanoparticles in a single pot using polyol solvents such as ethylene glycol and glycerol is demonstrated. The coexistence of 1T and 2H phases in MoS2 nanomaterials was determined using advanced techniques such as XRD, Raman, XPS, and TEM images. The highest 1T proportion obtained was 84.5% when compared to the 2H phase. The reaction mechanism and the phase transition between 1T and 2H were described and illustrated. The role of polyol solvents in the practical synthesis of nano MoS2 under microwave heating is also evaluated and explained. Due to the ability of the metallic 1T phase to enhance electrical conductivity, it is believed that hybrid nanostructures exhibit superior electrochemical performance for energy storage and conversion applications.

Green synthesis of iron nanoparticles (Fe(NPs)) using plant extract from Eucalyptus grandis: characterization and determination of the catalytic potential for reduction of 4-nitrophenol

This study assessed a green synthesis method for iron nanoparticles (Fe(NPs)), using Eucalyptus grandis leaf extract, to reduce waste generation and diminish the use of conventional chemical inputs, such as Sodium Borohydride (NaBH4), without significant losses in catalytic activity. Various volumetric ratios of plant extract and NaBH4 were tested to understand how this variation would affect the morphological, structural, and catalytic power of the material. In the conducted analyses, a reduction in the crystallinity of Fe(NPs) was observed for proportions above 25% of the extract. However, the particle size remained stable among different syntheses, with iron ions showing improved dispersion for proportions of 40% and 50% of the extract. Regarding stabilization, characteristic bands of aromatic compounds, alcohols, ethers and carboxylic acids were identified, indicating the extract's involvement in coating the metallic cores. To assess the catalytic performance, studies were conducted on the catalytic reduction of the contaminant 4-nitrophenol to 4-aminophenol, using Fe(NPs) as catalysts. The results revealed conversions above 80% for Fe(NPs) synthesized with volumetric proportions of up to 40% of the plant extract, suggesting that substituting the chemical agent did not significantly affect the catalytic activity of the biocatalyst. Finally, ecotoxicological tests performed with Lemna minor and artemia salina demonstrated a significant reduction in the toxicity of the contaminant 4-nitrophenol, as well as the biocompatibility of the obtained Fe(NPs). Keywords: iron oxides, stabilization, vegetable coating.

Spectroscopic investigations of green synthesized zinc oxide nanoparticles (ZnO NPs): antioxidant and antibacterial activity

In the recent decade, zinc oxide nanoparticles (ZnO NPs) have been widely explored owing to their versatile properties and prodigious demands in the drug delivery, medical, energy storage, cosmetics, and the healthcare sectors. Therefore, the current work opts for an environmentally benign method to prepare ZnO NPs. The leaf extract of Calendula officinalis L. acts as a reducing agent for the metal ions; therefore, in the current research, ZnO NPs were prepared via green route by using Calendula officinalis leaf extract. Furthermore, the ZnO NPs were analysed with different spectroscopic techniques to confirm the structure and stability of nanomaterials. The prepared ZnO NPs were characterized by XRD, FE-SEM, FT-IR and UV–Vis studies. Also, the antioxidant and antimicrobial properties of the synthesized ZnO NPs were investigated. The XRD result of synthesized ZnO NPs showed the crystalline size 28.23 nm with wurtzite hexagonal structure along with the most intense peak (101). Following preliminary confirmations of the intended ZnO NPs, both big and small agglomerated forms were observed in the FE-SEM, which is often used to determine their exterior assembly. Further, the results of Fourier transform infrared spectroscopy (FT-IR) indicated the formation of pure ZnO NPs with an absorption peak of the Zn–O bond between 4000 cm−1 and 500 cm−1 and no discernible peak in the monitoring range. The UV–Vis spectrum of the green synthesized ZnO NPs were revealed two prominent absorption peaks at 355 nm and 370 nm with energy band gap of 2.986 eV. Using the 1, 1-di phenyl-2-picrylhydrazyl (DPPH) test, the antioxidant activity of the described ZnO NPs was assessed. It demonstrated how, ZnO NPs significantly increased their antioxidant activity by scavenging 1, 1-di phenyl-2-picrylhydrazyl (DPPH) free radicals. It could be seen that synthesis of the naturally occurring plant product ZnO NPs have been acting as an alternate of chemical antioxidant. The antimicrobial analysis was also performed with the help of disk diffusion method where three multi-drug resistant human pathogens namely Staphylococcus aureus, Klebsiella pneumoniae and E.coli were used. The Zone of Inhibition diameter values are 35.2 mm ± 0.9, 23.6 mm ± 0.1 and 13.5 mm ± 0.1, respectively, which showed that the ZnO NPs was highly effective against S. aureus. Thus, the green synthesis method of ZnO NPs using leaf extract of Calendula officinalis is evidence that it is superior and environmentally friendly method for the preparation of ZnO NPs and hence it can be utilized in various nano-medicine approaches.

Advances in sustainable nano-biochar: precursors, synthesis methods and applications.

Nano-biochar, characterized by its environmentally friendly nature and unique nanostructure, offers a promising avenue for sustainable carbon materials. With its small particle size, large specific surface area, abundant functional groups and tunable pore structure, nano-biochar stands out due to its distinct physical and chemical properties compared to conventional biochar. This paper aims to provide an in-depth exploration of nano-biochar, covering its sources, transformation mechanisms, properties, applications, and areas requiring further research. The discussion begins with an overview of biomass sources for nano-biochar production and the conversion processes involved. Subsequently, primary synthesis methods and strategies for functionalization enhancement are examined. Furthermore, the applications of nano-biochar in catalysis, energy storage, and pollutant adsorption and degradation are explored and enhanced in various fields.

A two‐step sizing method for multistage Op Amps based on behavioral initial sizing followed by Spice‐in‐the‐loop refining

AbstractAnalog integrated circuit sizing is a laborious process that requires many times of iteration with Spice simulations. Even by applying the method, it still requires iterations and test assignment of device values (and biasings) in each iteration until reaching a satisfactory sizing result. When facing a design of multiple‐stage circuits (such as multiple‐stage operational amplifier [Op Amp]), sizing becomes more challenging due to the requirement on pole‐zero placement in order to achieve a better high‐frequency performance. Simulation‐in‐the‐loop method has been the dominating means taken by a great many of existing circuit sizer, but they suffer from intolerable runtime while lacking the possibility of offering insight or design knowledge acquisition. On the other hand, behavioral‐level synthesis methods, although intuitive and fast, suffer from accuracy loss due to the adoption of simplified device models and significantly condensed design equations. However, a proper combination of these two types of methods could lead to a lucrative research territory, yet it demands a methodological development for efficient deployment in practice, namely, implementation easy, less runtime, and guaranteed sizing quality. In this paper, we propose a two‐step method that takes the advantage of behavioral synthesis (in the first step) that is capable of fast and broader coverage of design space then makes correction (in the second step) on sizing refining by Spice simulation. Due to the profiling knowledge acquired on the design space in the first step, it can avoid blindness of the optimization landscape that is faced by many simulation‐centric methods which could easily get trapped in local optima. Conducted experiments over eight three‐stage Op Amps with different compensation configurations, including nested Miller capacitor (NMC), NMC with feedforward path (NMCF), NMC with feedforward path and nulling resistor (NMCFNR), NMC with nulling resistor (NMCNR), double pole‐zero cancellation (DPZC), transconductance with capacitances feedback compensation (TCFC), impedance adapting compensation (IAC), active feedback frequency compensation (AFFC), have validated that the proposed method can successfully generate qualified sizing results, offering an opportunity to compare fairly what merit a specific compensation strategy could possibly have.

Structure of ZnxFe3−xO4 nanoparticles studied by neutron diffraction and its relation with their response in magnetic hyperthermia experiments

The mixed zinc-ferrite spinel magnetic nanoparticles (MNPs) with the general formula ZnxFe3−xO4 are among the most extensively studied families of Fe oxides due to their interesting and diverse chemical, electronic, and magnetic properties. These systems offer the possibility of surface functionalization and possess high biocompatibility, making them highly attractive for applications in biomedicine, such as magnetic fluid hyperthermia (MFH). The efficiency of the MFH process relies on the magnetic, structural and morphological properties of the MNPs. The substitution with the Zn ion and the cationic distribution, as well as the synthesis process employed, have a direct impact on the final properties of these oxides. Therefore, it is essential to have tools that enable a comprehensive characterization of the system to assess its performance in MFH. In this study, we have synthesized four ZnxFe3−xO4 MNP systems using three different methods: two by thermal decomposition at high temperatures, one by co-precipitation, and another by co-precipitation followed by ball milling. We analyze the effect of these various synthesis processes on the magnetic and crystallographic properties, aiming to correlate them with the response of each system in MFH. Neutron diffraction data are employed to determine the cation site occupation and to investigate the correlation with the synthesis method. MFH measurements were conducted in media of diverse viscosities, revealing different values of specific loss power, thus demonstrating a clear dependence on the synthesis process and Zn content.

Method for Synthesis of 4-(4-Hydroxyphenyl)cycloalkanedicarboxylic Acids Based on SEAr Alkylation

A study was carried out on the alkylation reaction of anisole with cycloalkenedicarboxylic acids in the presence of various catalytic systems. It was found that the reaction proceeds with high yields in the presence of aluminum chloride, ferric chloride, and p-toluenesulfonic acid. The possibility of further cleavage of the ether bond to obtain 4-(4-hydroxyphenyl)cycloalkanedicarboxylic acids was demonstrated. The resulting compounds are potential biologically active compounds.

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations.

A steadily increasing number of reports have been published on chemo-enzymatic synthesis methods that integrate biosynthetic enzymatic transformations with chemical conversions. This review focuses on the total synthesis of natural products and classifies the enzymatic reactions into three categories. The total synthesis of five natural products: cotylenol, trichodimerol, chalcomoracin, tylactone, and saframycin A, as well as their analogs, is outlined with an emphasis on comparing these chemo-enzymatic syntheses with the corresponding natural biosynthetic pathways.

Synthesis and Structure of Barium Hexaferrite BaFe12–xInxO19 (x = 0–1)

This study presents the results of the synthesis and examination of indium-substituted barium hexaferrite samples with the formula BaFe12–xInxO19. The ferrites were obtained via a solid state synthesis method. The substitution level of indium, represented by x(In), was varied from 0 to 1 in 0.25 increments. The stoichiometric formulas of the compounds were calculated using the EDS data. The powder X-ray diffraction analysis indicated that all samples form a single crystalline phase with the M-type hexaferrite structure. Parameters of the crystal unit cell were calculated from powder diffraction data. An expansion of the crystal lattice parameters was observed as iron was substituted with indium, from x = 0 to x = 0.84. The Curie temperatures of the synthesized ferrites were determined using differential scanning calorimetry (DSC) method. It is established that the Curie temperature decreases from 452 to 292°C with In content growth from x = 0 to x = 0.84 in the BaFe12–xInxO19.