Article
Chemistry, Physical
Aleksey A. Nikitin, Anastasiia V. Prishchepa, Ruslan A. Rytov, Vladimir P. Chekhonin, Maxim A. Abakumov
Summary: The study investigates the remote magneto-mechanical actuation of biomolecules under the influence of external magnetic fields using magnetic nanoparticles. The results demonstrate a nonmonotonic dependence of mechanical destruction on the size of nanoparticles, indicating the crucial role of magneto-dipole interactions between nanoparticles. This finding contributes to the fine-tuning of magnetic nanoparticle properties for specific magneto-mechanical tasks.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2023)
Article
Crystallography
Mohamed S. A. Darwish
Summary: This study fabricated a series of photocatalysts based on magnetic ferrite nanostructures using a two-step co-precipitation technique. The fabricated magnetic photocatalysts were characterized using various methods. The results showed that MNPs exhibited outstanding performance as magnetic photocatalysts for the water-splitting process.
Article
Chemistry, Multidisciplinary
J. K. Han, A. A. Baker, J. R. I. Lee, S. K. McCall
Summary: Exchange coupling in a model core-shell system is demonstrated as a step towards 3D exchange spring magnets. High-quality core-shell nanoparticles of Ni@CoFe2O4 were fabricated using a simple two-step method. The microstructural quality was validated using TEM, confirming a well-defined interface between the core and the shell. Results showed a strongly temperature-dependent two-phase magnetic hysteresis loop, indicating a coupling of approximately 50% between the core and the shell. Element-specific XMCD hysteresis confirmed the presence of exchange coupling, suppressing the superparamagnetism of the Ni core at room temperature, and achieving a coercivity of >6 kOe at 80 K. These findings provide a pathway for the development of heterostructured metal-oxide exchange-coupled nanoparticles with improved maximum energy product.
Article
Materials Science, Multidisciplinary
Nikolaos Ntallis, Corisa Kons, Hariharan Srikanth, Manh-Huong Phan, D. A. Arena, Manuel Pereiro
Summary: In this study, the magnetic properties of ferrite nanoparticles were investigated using theoretical techniques based on Monte Carlo methods. Different levels of complexity were introduced to the macro-magnetic model, allowing for the study of single nanoparticles, core-shell nanoparticles, and assemblies of nanoparticles. The results showed good agreement with experimental data, providing an important tool for understanding the internal structure and spin interactions of ferrite nanoparticles.
Article
Materials Science, Ceramics
I Anila, B. B. Lahiri, Jacob Mathew, John Philip
Summary: The study demonstrates the viscosity-independent magnetic hyperthermia properties of chitosan-coated ultrafine CoFe2O4 MNPs, showing higher field-induced heating efficiency.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Multidisciplinary
Mai M. El-Masry, Rania Ramadan
Summary: Cobalt ferrite, copper ferrite, and cobalt doped copper ferrite nanoparticles were synthesized and characterized, and they were found to be promising fillers for PVDF polymer, improving its optical and piezoelectric properties.
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
(2022)
Article
Chemistry, Multidisciplinary
Diana Zahn, Joachim Landers, Marco Diegel, Soma Salamon, Andreas Stihl, Felix H. Schacher, Heiko Wende, Jan Dellith, Silvio Dutz
Summary: This study reports the synthesis and characterization of high coercivity cobalt ferrite nanoparticles using a wet co-precipitation method. The results show that the properties of the nanoparticles, including crystallinity, coercivity, and magnetization, can be tuned by varying the synthesis conditions and atmosphere. The influence of cobalt fraction on the magnetic and structural properties of the particles is also investigated, revealing a direct correlation between high-field magnetization, an antiferromagnetic phase, and the estimated transition temperature.
Article
Chemistry, Physical
T. Muthukumaran, John Philip
Summary: In this study, cobalt ferrite nanoparticles capped with an ultrathin phosphate layer were synthesized and characterized. The phosphate moieties greatly enhanced the adsorption of methylene blue, while the adsorption efficiency and capacity of other dyes on the particles were low. The interaction between different functional groups of dyes and the phosphate moieties on the particles was studied. The approach is found to be suitable for dye removal without labor-intensive steps compared to nonmagnetic nanoparticle based methods.
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
(2021)
Article
Physics, Applied
Sudhir Regmi, Zhong Li, K. C. Shambhu, Rabin Mahat, Ankur Rastogi, Ranjan Datta, Arunava Gupta
Summary: Epitaxial thin films of cobalt ferrite have been successfully grown on isostructural substrates using pulsed laser deposition. The films on ZnGa2O4 substrates are defect-free and under slight compressive strain, while the films on MgGa2O4 substrates show strain relaxation and defect formation.
APPLIED PHYSICS LETTERS
(2022)
Article
Chemistry, Multidisciplinary
Pendaranahalli Nadikeraiah Anantharamaiah, Hadonahalli Munegowda Shashanka, Srikari Srinivasan, Debabrata Das, Ahmed A. El-Gendy, C. V. Ramana
Summary: This study reports on the fabrication, characterization, and evaluation of cobalt ferrite nanocrystalline thin films on a flexible mica substrate. The CFO films exhibited single-phase and nanocrystalline nature, spherical shape morphology, and suitable magnetic and magnetostrictive properties for flexible sensor devices.
Article
Chemistry, Multidisciplinary
Pengfei Hu, Dong Zhou, Shiqing Xu, Qianru Ma, Jiaqi Yin, Yali Cao, Jing Xu
Summary: This study successfully achieved room-temperature aqueous phase- and size-controlled synthesis of CdS nanocrystals by modulating the pH value and using chelator ethylenediamine for guiding the assembly of nanocrystals.
Article
Materials Science, Ceramics
Andre de Oliveira Girao Maia, Francisco Gilvane Sampaio Oliveira, Carlos Henrique Nascimento Cordeiro, Edwalder Silva Teixeira, Erandir Brasil da Silva, Joao Maria Soares, Igor Frota de Vasconcelos, Jose Marcos Sasaki, Thomas Dumelow
Summary: This work synthesized superparamagnetic cobalt ferrite nanoparticles using a sol-gel method and characterized the samples using different instruments. Magnetic hardening and an increase in anisotropy constant were observed with increasing nanoparticle size. Additionally, a decrease in saturation magnetization due to the formation of magnetically dead layer on the surface was also observed.
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
(2021)
Article
Biochemistry & Molecular Biology
Rocio Redon, Miriam D. Aviles-Avila, Leopoldo Ruiz-Huerta, Herlinda Montiel, Alex Elias-Zuniga, Lucy-Caterine Daza-Gomez, Oscar Martinez-Romero
Summary: By utilizing additive manufacturing and nanotechnology, magnetic cobalt ferrite and barium ferrite nanoparticles were incorporated into commercial resins and successfully transferred their magnetic properties to the final 3D-printed pieces through photopolymerization.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Article
Materials Science, Multidisciplinary
A. V. Ravindra, Shaohua Ju
Summary: Cobalt ferrite (CoFe2O4) nanoparticles with a size of 7-20 nm were easily synthesized by a microwave-hydrothermal route at temperatures of 100, 150, and 200 degrees C. The synthesized nanoparticles exhibited a pure spinel CoFe2O4 phase, high thermal stability, and a spherical morphology. The magnetic properties of the nanoparticles varied with synthesis temperature/particle size, with an increase in MS value and a decrease in Mr and Hc values as the temperature increased. The findings of this study provide insights into tailoring the properties of CoFe2O4 nanoparticles for specific applications using microwave-hydrothermal synthesis.
MATERIALS CHEMISTRY AND PHYSICS
(2023)
Article
Engineering, Electrical & Electronic
Reshma Prakshale, Sachin Bangale, Mahesh Kamble, Sanjay Sonawale
Summary: A solution combustion method was used to synthesize nanocrystalline spinel structured CoFe2O4, which showed high sensitivity and good selectivity to ethanol.
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
(2023)
Article
Chemistry, Applied
Jean-Bosco Jouda, Emmanuel Mfotie Njoya, Ruland Tchuinkeu Nguengang, Virginie Flaure Tsague Tankeu, Hans-Georg Stammler, Yoshihito Shiono, Norbert Sewald, Alain Meli Lannang
Summary: A new compound, asperpyrone (1), and two known compounds, stigmasterol (2) and 7-hydroxy-3-(2,3-dihydroxybutyl)-1(3H)-isobenzofuranone (3), were isolated from the solid rice culture of the endophytic fungus Aspergillus sp. The structure of asperpyrone (1) was determined through extensive spectral analysis. However, asperpyrone (1) did not show significant amoebicidal activity against Entamoeba moshkovskii in axenic culture.
NATURAL PRODUCT RESEARCH
(2023)
Article
Chemistry, Applied
Rostan Mangoua Talla, Jean-Bosco Jouda, Isabelle Kamga Mawabo, Catherine Tegasne, Gervais Mouthe Happi, Gilbert Deccaux Wabo Fotso Kapche, Bruno Ndjakou Lenta, Norbert Sewald, Jean Wandji
Summary: The methanol extract of Chrysophyllum lacourtianum stem bark yielded a new secondary metabolite, lacourtianal (1), and eight known compounds. The structures of these compounds were determined by NMR spectroscopic and mass spectrometric analysis. The antibacterial activity of the methanol extract and compounds 1-9 were tested, and lacourtianal (1) and ursolic acid (5) showed strong antibacterial activity.
NATURAL PRODUCT RESEARCH
(2023)
Article
Chemistry, Multidisciplinary
Jannik Paulus, Beate Nachtigall, Peter Meyer, Norbert Sewald
Summary: A library of sulfonamide-modified RGD mimetics with high affinity for integrin alpha(V)beta(3) was synthesized. The best structure was selected and conjugated with a cleavable linker and the drug MMAE to form a SMDC. The resulting SMDC showed high affinity and selectivity for alpha(V)beta(3).
CHEMISTRY-A EUROPEAN JOURNAL
(2023)
Article
Physics, Applied
S. Pfeiffer, T. Baumgartner, S. Loeffler, M. Stoeger-Pollach, S. C. Hopkins, A. Ballarino, M. Eisterer, J. Bernardi
Summary: We used SEM and SHPM to analyze inhomogeneities in Nb3Sn wires. We investigated the inhomogeneities of the A15 phase in Nb3Sn sub-elements of Ti-alloyed Restacked Rod Process wire and Ta-alloyed Powder-In-Tube wire. SEM was used to examine microstructural features, EDX for elemental concentration gradients, and SHPM for superconducting properties. Correlations between the results were analyzed to understand the impact of inhomogeneities on the superconducting properties. Significant differences in geometry and performance were found between sub-elements, as well as compositional and geometric inhomogeneities within single sub-elements. Simulation of Sn concentration gradients' influence on critical current density was also performed. The viability of SHPM and EDX for determining the dependence of critical temperature on Sn concentration was demonstrated, and potential performance gains through reduction of inhomogeneities in Nb3Sn wires were discussed.
SUPERCONDUCTOR SCIENCE & TECHNOLOGY
(2023)
Article
Plant Sciences
Michel Arnaud Mbock, Raceline Gounoue Kamkumo, Rohit Shukla, William Feudjou Fouatio, Patrick Valere Tsouh Fokou, Florence Ngueguim Tsofack, Clarice Djouwoug Noussi, Rodrigue Fifen, Augustin Ephrem Nkengfack, Tiratha Raj Singh, Bruno Lenta Ndjakou, Norbert Sewald, Fabrice Fekam Boyom, Jean Justin Essia Ngang, Onana Boyomo, Theophile Dimo
Summary: This study evaluated the curative effects of the hydroethanolic extract of Detarium microcarpum root bark on Salmonella typhimurium-induced typhoid in rat and explored the in-silico inhibition of some bacterial key enzymes. The results demonstrated potent anti-typhoid activities of the extract through antioxidant properties and high inhibitory affinity of its compounds on some bacterial key enzymes, justifying its use as traditional medicine for typhoid fever.
JOURNAL OF ETHNOPHARMACOLOGY
(2023)
Article
Chemistry, Physical
Bel Youssouf G. Mountessou, Alexis Sylvain W. Mbobda, Hans -Georg Stammler, Eric O. Akintemi, Maraf B. Mbah, Gervais M. Happi, Simeon F. Kouam, Bruno N. Lenta, Norbert Sewald, Thishana Singh, Ibrahim N. Mbouombouo
Summary: The structural, electronic, spectroscopic, and chemical reactivity properties of costunolide were investigated using experimental and theoretical methods. The absolute configurations of the two chiral centres were determined by XRD analysis. DFT calculations accurately predicted the vibrational frequencies, electronic properties, and molecular structure of costunolide. The compound exhibited nonlinear optical properties and strong binding affinity to the main protease of Onchocerca volvulus.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Biochemistry & Molecular Biology
Ruland Tchuinkeu Nguengang, Billy Toussie Tchegnitegni, Eric Carly Nono Nono, Georges Bellier Tabekoueng, Yannick Stephane Fotsing Fongang, Jean Jules Kezetas Bankeu, Jean Rodolphe Chouna, Celine Nguefeu Nkenfou, Fabrice Boyom Fekam, Norbert Sewald, Bruno Ndjakou Lenta
Summary: The chemical investigation of the n-hexane fraction from the methanol extract of the stem bark of Symphonia globulifera Linn f. led to the isolation of three previously unreported polyprenylated benzophenones and a new tocotrienol derivative, along with 11 known compounds. Some isolated compounds showed promising antileishmanial and cytotoxic activities, with guttiferone K exhibiting the best potency but low selectivity to Vero cells. The n-hexane fraction and some compounds also exhibited moderate to potent antibacterial activity.
Article
Chemistry, Applied
Willifred Dongmo Tekapi Tsopgni, Flaure Rosette Ehawa Essoung, Phalonne Makam Kuetche, Anatole Guy Blaise Azebaze, Mbah James Ajeck, Alain Lannang Meli, Norbert Sewald, Jean Duplex Wansi, Alain Francois Kamdem Waffo, Alain Tadjong Tcho
Summary: The chemical investigation of Flacourtia vogelii's methanolic root extract resulted in the identification of a new arylbenzoate derivative, vogelinal (1), and thirteen known compounds (2-14). The structures of the isolated compounds were determined through extensive spectroscopic and spectrometric analyses, in addition to comparison with existing data. Antioxidant, antifungal, and antibacterial activities were evaluated for all compounds. Compound 7 exhibited the highest antioxidant potential, while compound 13 displayed weak antifungal effect against Candida parapsilosis, and compound 8 showed weak antibacterial effect against Shigella dysenteria. This study suggests that Flacourtia vogelii could be a valuable source of antioxidant and antibacterial constituents.
NATURAL PRODUCT RESEARCH
(2023)
Article
Biochemistry & Molecular Biology
Hermine Wete Nono, Arno Rusel Donfack Nanfack, Billy Toussie Tchegnitegni, Cyrille Armel Njanpa Ngansop, Faustine Leonie Mafodong Dongmo, Maurice Ducret Awouafack, Fabrice Fekam Boyom, Bruno Lenta Ndjakou, Hans-Georg Stammler, Beate Neumann, Norbert Sewald, Silvere Augustin Ngouela
Summary: The phytochemical investigation of Helichrysum foetidum led to the isolation of four undescribed compounds, including two ent-beyer-15-ene-type diterpenoids, foetidumins A and B, one flavonoid, foetidumin C, and one chalcopyrone, foetidumin D. In addition, fourteen known compounds were also isolated. Foetidumin C, erythroxylol A, and kaempferol showed the highest antileishmanial potency. The extracts of flowers and twigs also exhibited high activity against Plasmodium falciparum.
Article
Chemistry, Multidisciplinary
Gaelle Talle Juidzou, Elodie Gisele Mouafo Anoumedem, Denis Kehdinga Sema, Virginie Flaure Tsague Tankeu, Peron Bosco Leutcha, Larissa Yetendje Chimi, Jean Paul Dzoyem, Simeon Kouam Fogue, Norbert Sewald, M. Iqbal Choudhary, Alain Meli Lannang
Summary: A new unsaturated aliphatic anhydride derivative and ten known compounds were isolated from a fungus inhabiting Pittosporum mannii. The p-terphenyls are suggested as the chemophenetic marker for the genus Aspergillus. The tested sample showed good antibiofilm activity, low anti-inflammatory activity, and moderate cytotoxicity.
JOURNAL OF CHEMISTRY
(2023)
Article
Biochemistry & Molecular Biology
Tobias Heinks, Simon Koopmeiners, Nicolai Montua, Norbert Sewald, Matthias Hoehne, Uwe T. Bornscheuer, Gabriele Fischer von Mollard
Summary: An enzyme cascade consisting of l-amino acid oxidase (hcLAAO4) and catalase (hCAT) was immobilized together with the (S)-selective amine transaminase (ATA-Vfl) to achieve higher reaction rates and more efficient H2O2-removal. The co-immobilized enzyme cascade showed good stability and high enantiomeric purity in preparative kinetic resolutions. However, further recycling was limited due to the instability of ATA-Vfl. The use of an engineered ATA-Vfl-8M in the immobilized enzyme cascade allowed a significant reduction in the amount of co-substrate required.
Article
Chemistry, Physical
Bel Youssouf G. Mountessou, Alain W. Ngouonpe, Alexis Sylvain W. Mbobda, Eric O. Akintemi, Hans-Georg Stammler, Simeon F. Kouam, Jean Claude Tchouankeu, Bruno N. Lenta, Norbert Sewald, Thishana Singh, Ibrahim N. Mbouombouo
Summary: Through single crystal X-ray diffraction and analysis, the intermolecular interactions in the solid state of the naturally occurring flavone derivative, pachypodostyflavone, were revealed. Experimental and theoretical investigations combining vibrational spectroscopies and density functional theory were performed. The compound was found to be more reactive in water, making it a good candidate for clinical preparations. In addition, thermodynamic properties and molecular docking results were presented.
JOURNAL OF MOLECULAR STRUCTURE
(2023)
Article
Chemistry, Applied
Charlemagne Ndoumbe Tamba, Willifred Dongmo Tekapi Tsopgni, Bernard Samuel Hodjie Fotso, Jean Pierre Longue Ekon, Mohamed Foundikou Nsangou, Judith Caroline Ngo Nyobe, Norbert Sewald, Jean Claude Ndom
Summary: The chemical investigation of the methanolic root extract of Caloncoba glauca revealed two new triterpenes, glaucalactones A and B, along with eight known compounds. The structures of the isolates were determined through spectroscopic and spectrometric analyses and comparison with previous data. The compounds were tested for antioxidant, antifungal, and antibacterial activities, with compound 1 showing weak antibacterial effect and compound 6 exhibiting moderate antifungal activity.
NATURAL PRODUCT RESEARCH
(2023)
Article
Biochemistry & Molecular Biology
Nadine Tseme Wandji, Gabin Thierry M. Bitchagno, Isabelle Mawabo Kamga, Joseph Tchamgoue, Celine Nguefeu Nkenfou, Bruno Ndjakou Lenta, Norbert Sewald, Simeon Fogue Kouam
Summary: Four polyoxygenated stigmastanes, along with known analogues and flavonoids, were isolated from the whole plant of Vernonia kotschyana. Their structures were determined through spectroscopic and spectrometric analysis. The antibacterial activity of the crude extract, fractions, and compounds was evaluated against prevalent bacterial strains, showing low to moderate activity.
Article
Biochemistry & Molecular Biology
Christian Martial Mileng Ndoumbe, Raymond Ngansop Nono, Jean Francois Zeutsop, Gabin Thierry Mbahbou Bitchagno, Bruno Ndjakou Lenta, Pepin Nkeng-Efouet-Alango, Norbert Sewald, Jean Rodolphe Chouna
Summary: A new iridoid, mitragynoid, and twelve known natural derivatives were isolated from the fruits of Mitragyna stipulosa. In addition, three likely-artifact irido-alkaloids that may have formed during the alkaloids extraction process were also isolated. The structures of these compounds were determined using spectroscopic methods, and a proposed biosynthetic route for the new ring formation was presented.
BIOCHEMICAL SYSTEMATICS AND ECOLOGY
(2023)