jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Tapan Kumar Dash | Diptendu Patra | Parvathy Venu | Biswajit Das | Rangeet Bhattacharyya | Raja Shunmugam
Source: ACS Applied Bio Materials (article, 2021-05-27)
Field: Materials Science — Biomaterials

Hetero-Trifunctional Malonate-Based Nanotheranostic System for Targeted Breast Cancer Therapy Designing multifunctional linkers is crucial for tricomponent theranostic targeted nanomedicine development as they are essential to enrich polymeric systems with different functional moieties. Herein, we have obtained a hetero-trifunctional linker from malonic acid and demonstrated its implication as an amphiphilic targeted nanotheranostic system (CB DX UN PG FL). We synthesized it with varying hydrophilic segment to fine-tune the hydrophobic/hydrophilic ratio to optimize its self-assembly. pH-responsive hydrazone-linked doxorubicin was conjugated to the backbone (UN PG FL) containing folate as a targeting ligand. Cobalt carbonyl complex was used for T2-weighted magnetic resonance imaging (MRI). Electron micrographs of optimized molecule CB DX UN PG(4 kDa) FL in an aqueous system have demonstrated about 50–60 nm-sized uniform micelles. The relaxivity study and the one-dimensional (1D) imaging experiments clearly revealed the effect of the nanotheranostics system on transverse relaxation (T2) of water molecules, which validated the system as a T2-weighted MRI contrast agent. The detailed in vitro biological studies validated the targeted delivery and anticancer potential of CB DX UN PG(4 kDa) FL. Combining the data on transverse relaxation, folate mediated uptake, and anticancer activity, the designed molecule will have a significant impact on the development of targeted theranostic. Chemistry ; Nanomedicine ; Small molecule ; Amphiphile ; Micelle ; Molecule ; Linker ; Ligand (biochemistry) ; Combinatorial chemistry ; Nanotechnology ; Aqueous solution ; Biophysics ; Materials science ; Copolymer ; Organic chemistry ; Polymer ; Biochemistry ; Receptor ; Nanoparticle Nanoparticle-Based Drug Delivery ; Nanoplatforms for cancer theranostics ; Nanocluster Synthesis and Applications
Authors: Irene Russo Krauss | Domenico Cavasso | Donato Ciccarelli | Richard K. Heenan | Ornella Ortona | Gerardino D’Errico | Luigi Paduano
Source: Journal of Molecular Liquids (article, 2021-04-19)
Field: Chemistry — Organic Chemistry

A Hofmeister series perspective on the mixed micellization of cationic and non-ionic surfactants Hofmeister series ; Chemistry ; Cationic polymerization ; Salt (chemistry) ; Halide ; Pulmonary surfactant ; Bromide ; Inorganic chemistry ; Ion ; Aggregation number ; Micelle ; Chemical engineering ; Critical micelle concentration ; Organic chemistry ; Aqueous solution Surfactants and Colloidal Systems ; Spectroscopy and Quantum Chemical Studies ; Photochemistry and Electron Transfer Studies
Authors: Jingrui Li | Hongguang Li | Jingcheng Hao
Source: Nanoscale (article, 2021-12-22)
Field: Chemistry — Organic Chemistry

Fullerene superlattices containing charge transfer complexes for an improved nonlinear optical performance To improve the nonlinear optical (NLO) properties of fullerene C<sub>60</sub>, chemical modifications are normally needed to construct a donor-π-acceptor (D-π-A) system, which requires tedious and time-consuming synthesis procedures. In addition, the conjugated structure of C<sub>60</sub> will inevitably be destroyed, which is disadvantageous for other applications. Here, we use solvent-based nanoarchitectonics to obtain highly ordered, three-dimensional (3D) C<sub>60</sub> supramolecular structures. For this purpose, a liquid-liquid interfacial precipitation (LLIP) method was employed using quinoline as the good solvent. Hollow polyhedra (HPH) and multilayer flowers (MFs) were obtained when methanol and ethanol were selected as the poor solvents, respectively. While quinoline failed to enter the HPH, it was found to be successfully intercalated with the MFs, which induced a transition of the C<sub>60</sub> organization from a pristine face-centered-cubic (fcc) phase to a hexagonal close packed (hcp) lattice. When embedded in a poly(methyl methacrylate) (PMMA) matrix, the HPH and MFs both show reverse saturable absorption (RSA) and optical limiting (OL) properties. The MFs-based film showed a third-order nonlinear absorption coefficient (<i>β</i>) of 1.25 × 10<sup>5</sup> cm·GW<sup>-1</sup> and an optical limiting threshold (<i>F</i><sub>ol</sub>) of 0.00625 J·cm<sup>-2</sup>. Comparatively, the HPH-based film exhibited a lower <i>β</i> value of 9.80 × 10<sup>4</sup> cm GW<sup>-1</sup> and a higher <i>F</i><sub>ol</sub> value of 0.00834 J cm<sup>-2</sup>. The better NLO performance of the MFs was mainly ascribed to the formation of the charge transfer complexes between quinoline and C<sub>60</sub>, proven by UV-vis and electrochemical measurements. The fine tuning of the NLO properties of C<sub>60</sub> without chemical modification provides new opportunities for C<sub>60</sub> to be applied in nonlinear optics. Superlattice ; Materials science ; Limiting ; Supramolecular chemistry ; Nonlinear optical ; Fullerene ; Nonlinear optics ; Charge (physics) ; Absorption (acoustics) ; Optoelectronics ; Nanotechnology ; Nonlinear system ; Saturable absorption ; Molecule ; Chemistry ; Organic chemistry ; Physics Fullerene Chemistry and Applications ; Nonlinear Optical Materials Studies ; Porphyrin and Phthalocyanine Chemistry
Authors: Mehmet Berat Taskin | Tina Tylek | Carina Blum | Christoph Böhm | Christina Wiesbeck | Jürgen Gröll
Source: ACS Biomaterials Science & Engineering (article, 2021-06-11)
Field: Materials Science — Biomaterials

Inducing Immunomodulatory Effects on Human Macrophages by Multifunctional NCO-sP(EO-<i>stat</i>-PO)/Gelatin Hydrogel Nanofibers Endowing materials and scaffolds with immunomodulatory properties has evolved into a very active field of research. However, combining such effects with multifunctionality regarding cell adhesion and manipulation is still challenging due to the intricate nature of cell-substrate interactions that require fine-tuning of scaffold properties. Here, we reported electrospinning of a well-known biopolymer, gelatin, together with six-arm star-shaped poly(ethylene oxide-<i>stat</i>-propylene oxide) prepolymer with isocyanate end groups (NCO-sP(EO-<i>stat</i>-PO)) as a reactive prepolymer cross-linker. Covalent coupling of two components during and after processing yielded a network of hydrogel fibers that was remarkably stable under aqueous and also proteolytic conditions without the need for extra cross-linking, with a significant increase in stability with increasing NCO-sP(EO-<i>stat</i>-PO) content. When seeded with human macrophages, cells adhered and spread on the fibers and were found highly viable after 7 days of culture across all scaffolds. Furthermore, hybrid fibrous meshes upregulated the expression of a prohealing gene, CD206, while downregulating proinflammatory genes, IL-1β and IL-8. Markedly, NCO-sP(EO-<i>stat</i>-PO)-rich samples induced a significantly reduced release of proinflammatory cytokines, IL-1β, IL-6, and IL-8. Finally, we successfully conjugated IL-4 to NCO-sP(EO-<i>stat</i>-PO) that effectively steered macrophages into a prohealing M2 type, demonstrating additional and robust control over the immunomodulatory feature of the scaffolds. Proinflammatory cytokine ; Gelatin ; Prepolymer ; Electrospinning ; Biophysics ; Nanofiber ; Materials science ; Chemistry ; Polyurethane ; Nanotechnology ; Biochemistry ; Inflammation ; Polymer ; Immunology Electrospun Nanofibers in Biomedical Applications ; Nerve injury and regeneration ; Advanced Sensor and Energy Harvesting Materials
Authors: Roberta Teixeira Polez | Bruno V. M. Rodrigues | Omar A. El Seoud | Elisabete Frollini
Source: Journal of Molecular Liquids (article, 2021-06-17)
Field: Materials Science — Biomaterials

Electrospinning of cellulose carboxylic esters synthesized under homogeneous conditions: Effects of the ester degree of substitution and acyl group chain length on the morphology of the fabricated mats Electrospinning ; Nanofiber ; Cellulose ; Cellulose acetate ; Polymer chemistry ; Chemical engineering ; Solvent ; Carboxylic acid ; Morphology (biology) ; Chemistry ; Materials science ; Organic chemistry ; Polymer ; Nanotechnology Electrospun Nanofibers in Biomedical Applications ; Advanced Cellulose Research Studies ; Advanced Sensor and Energy Harvesting Materials
Authors: Gabriel Mendes | Leon Kluskens | S. Lanceros‐Méndez | Manuel Mota
Source: Applied Clay Science (article, 2021-02-26)
Field: Materials Science — Materials Chemistry

Magnesium aminoclays as plasmid delivery agents for non-competent Escherichia coli JM109 transformation Magnesium aminoclays were synthesized and used to transform non-competent Escherichia coli JM109 using the exogenous plasmid pUC19. The structure determined for the Mg aminoclays is analogous to 2:1 trioctahedral smectites such as talc, with an approximate composition R8Si8Mg6O16(OH)4, where R = CH2CH2NH2, morphologically arranged in layered sheets. Mg aminoclays were employed as a cationic vehicle that enabled the passage of plasmids across the cell envelope and led to genetic modification of the host. A stock solution of 10 mg/mL of Mg aminoclays was prepared, mixed with E. coli JM109 and pUC19 plasmid, and spread over Petri dishes containing lysogeny broth (LB), isopropyl β-D-1-thiogalactopyranoside (IPTG), 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside (X-gal), ampicillin and various concentrations of agar (1–4%). The transformation efficiency obtained was higher for 1% and 2% agar even though transformation also occurred at agar concentrations of 3% and 4%. The optical density of E. coli JM109 and spreading time were also adjusted, favoring transformation when cells were used in their exponential growth phase (OD600 = 1.0) and spread for 90 s. Transformation was confirmed by the growth of blue colonies in LB/IPTG/X-gal/agar Petri dishes containing ampicillin, by regrowth of biomass in liquid media containing ampicillin and by agarose gel electrophoresis of the linearized pUC19 plasmid that followed plasmidic DNA extraction from 4 blue colonies. The maximum transformation efficiency achieved was 7.0 × 103 CFU/μg pUC19. This transformation approach proved to be suitable for a convenient, cost-effective, room-temperature, risk-free and rapid transformation of non-competent E. coli JM109. pUC19 ; Transformation efficiency ; Plasmid ; Transformation (genetics) ; Escherichia coli ; Agar ; Chemistry ; Microbiology ; Agar plate ; Biology ; Agrobacterium ; Bacteria ; Biochemistry ; DNA ; Gene ; Genetics Layered Double Hydroxides Synthesis and Applications ; Phosphorus and nutrient management ; Calcium Carbonate Crystallization and Inhibition
Authors: Jesper Dahl Jensen | Niels Bisballe | Laura Kacenauskaite | Maria Storm Thomsen | Junsheng Chen | Ole Hammerich | Bo W. Laursen
Source: The Journal of Organic Chemistry (article, 2021-11-18)
Field: Chemistry — Organic Chemistry

Utilizing Selective Chlorination to Synthesize New Triangulenium Dyes Functionalization of new sites on the triangulenium structure has been achieved by early-stage chlorination with <i>N</i>-chlorosuccinimide (NCS), giving rise to two new triangulenium dyes (<b>1</b> and <b>3</b>). By introducing the chlorine functionalities in the acridinium precursor, positions complementary to those previously obtained by electrophilic aromatic substitution on the final dyes are accessed. The chlorination is selective, giving only one regioisomer for both mono- and dichlorination products. For the monochlorinated acridinium compound, a highly selective ring-closing reaction was discovered, generating a single regioisomer of the cationic [4]helicene product. Further investigations into the mechanism of the [4]helicene formation lead to the first isolation of the previously proposed intermediate of the two-step S<sub>N</sub>Ar reaction, key to all aza-bridged triangulenium and helicenium systems. Late-stage functionalization of DAOTA<sup>+</sup> with NCS gave rise to a different dichlorinated compound (<b>2</b>). The fully ring closed chlorinated triangulenium dyes <b>1</b>, <b>2</b>, and <b>3</b> show a redshift in absorption and emission, while maintaining relatively high fluorescence quantum yields of 36%, 26%, and 41% and long fluorescence lifetimes of 15, 12.5, and 16 ns, respectively. Cyclic voltammetry shows that chlorination of the triangulenium dyes significantly lowers reduction potentials and thus allows for efficient tuning of redox and photoredox properties. Helicene ; Chemistry ; Structural isomer ; Electrophilic substitution ; Combinatorial chemistry ; Cationic polymerization ; Fluorescence ; Photochemistry ; Electrophilic aromatic substitution ; Ring (chemistry) ; Nucleophilic aromatic substitution ; Organic chemistry ; Nucleophilic substitution ; Molecule Synthesis and Properties of Aromatic Compounds ; Porphyrin and Phthalocyanine Chemistry ; Photochromic and Fluorescence Chemistry
Authors: Ploychanok Iadrat | Chularat Wattanakit
Source: Catalysts (article, 2021-09-26)
Field: Chemistry — Inorganic Chemistry

Bioethanol Upgrading to Renewable Monomers Using Hierarchical Zeolites: Catalyst Preparation, Characterization, and Catalytic Studies Bioethanol is one of the most promising renewable resources for the production of important monomers. To date, there have been various processes proposed for bioethanol conversion to renewable monomers. In this review, the catalytic bioethanol upgrading to various types of monomers using hierarchical zeolites as catalysts is illustrated, including the recent design and preparation of hierarchical zeolites for these catalytic processes. The characterizations of catalysts including textural properties, pore architectures, acidic properties, and active species are also exemplified. Moreover, the catalytic studies with various processes of monomer production from bioethanol including bioethanol dehydration, bioethanol to hydrocarbons, and bioethanol to butadiene are revealed in terms of catalytic activities and mechanistic studies. In addition, the future perspectives of these catalytic circumstances are proposed in both economic and sustainable development contexts. Biofuel ; Catalysis ; Renewable resource ; Biochemical engineering ; Renewable energy ; Materials science ; Monomer ; Chemistry ; Chemical engineering ; Organic chemistry ; Waste management ; Engineering ; Polymer Zeolite Catalysis and Synthesis ; Catalysis for Biomass Conversion ; Catalysis and Hydrodesulfurization Studies
Authors: David T. Jenkins | Eszter Fazekas | Samuel B. H. Patterson | Georgina M. Rosair | Filipe Vilela | Ruaraidh D. McIntosh
Source: Catalysts (article, 2021-04-27)
Field: Materials Science — Biomaterials

Polymetallic Group 4 Complexes: Catalysts for the Ring Opening Polymerisation of rac-Lactide Five novel air- and moisture-stable polymetallic Ti and Zr amino acid-derived amine bis(phenolate) (ABP) complexes were synthesised and fully characterised, including X-ray crystallographic studies. The reaction of the ABP proligands with Ti or Zr alkoxides has resulted in the formation of polymetallic aggregates of different nuclearity. The steric bulk on the pendant arm of the ligand was found to play a critical role in establishing the nuclearity of the aggregated complex. Sterically, less-demanding groups, such as H or Me, facilitated the formation of tetrametallic Ti clusters, bridged by carboxylate groups, while increased steric bulk (tBu) led to the formation of binuclear μ-oxo-bridged species. The isolated complexes were employed as catalysts for the ring opening polymerisation (ROP) of rac-lactide. Overall, the Ti catalysts were all active with the smaller, bimetallic Ti aggregates exhibiting relatively faster rates. A monometallic, bis(ABP) Zr complex was found to exert remarkable ROP activity, albeit with limited control over the tacticity and molecular weight distribution of the polymer. A further oxo-bridged Zr cluster was shown to display a previously unprecedented trimetallic structure and achieved a moderate rate in the ROP of rac-lactide. Steric effects ; Lactide ; Bimetallic strip ; Catalysis ; Polymer chemistry ; Ligand (biochemistry) ; Polymerization ; Carboxylate ; Chemistry ; Tacticity ; Ring-opening polymerization ; Amine gas treating ; Polymer ; Crystallography ; Stereochemistry ; Organic chemistry biodegradable polymer synthesis and properties ; Carbon dioxide utilization in catalysis ; Organometallic Complex Synthesis and Catalysis
Authors: Ofek Golan | Hila Shalom | Ifat Kaplan‐Ashiri | Sidney Cohen | Yishay Feldman | Iddo Pinkas | Rakefet Ofek Almog | Alla Zak | Reshef Tenne
Source: Polymers (article, 2021-11-08)
Field: Materials Science — Biomaterials

Poly(L-lactic acid) Reinforced with Hydroxyapatite and Tungsten Disulfide Nanotubes Poly(L-lactic acid) (PLLA) is a biocompatible, biodegradable, and semi-crystalline polymer with numerous applications including food packaging, medical implants, stents, tissue engineering scaffolds, etc. Hydroxyapatite (HA) is the major component of natural bone. Conceptually, combining PLLA and HA could produce a bioceramic suitable for implants and bone repair. However, this nanocomposite suffers from poor mechanical behavior under tensile strain. In this study, films of PLLA and HA were prepared with small amounts of nontoxic WS<sub>2</sub> nanotubes (INT-WS<sub>2</sub>). The structural aspects of the films were investigated via electron microscopy, X-ray diffraction, Raman microscopy, and infrared absorption spectroscopy. The mechanical properties were evaluated via tensile measurements, micro-hardness tests, and nanoindentation. The thermal properties were investigated via differential scanning calorimetry. The composite films exhibited improved mechanical and thermal properties compared to the films prepared from the PLLA and HA alone, which is advantageous for medical applications. Tungsten disulfide ; Lactic acid ; Tungsten ; Disulfide bond ; Materials science ; Polymer chemistry ; Chemistry ; Composite material ; Biochemistry ; Metallurgy ; Bacteria biodegradable polymer synthesis and properties ; Bone Tissue Engineering Materials ; Advanced Polymer Synthesis and Characterization
Authors: Rini Purbowati | Sugiharto Sugiharto | Agusniar Furkani Listyawati | Masfufatun Masfufatun | Lusiani Tjandra | Noer Kumala Indahsari
Source: Berkala Penelitian Hayati (article, 2021-12-25)
Field: Materials Science — Materials Chemistry

Antibacterial and antibiofilm effect of silver and gold nanoparticles in Uropathogenic Escherichia coli Nosocomial infections of the urinary tract are the most common nosocomial infections. Infectious diseases currently pose a life threatening due to the increasing phenomenon of infectious agent resistance. One of the factors known to cause resistance to broad-spectrum antimicrobials agent is the susceptibility to biofilm formation. The use of silver nanoparticles (NPs) is now regarded as one of the most promising strategies to target infections associated with biofilms. This study aims to determine the application of nanotechnology in the form of metal nanoparticles in targeting the formation of biofilms on infectious agents. The antibacterial and antibiofilm activity test was performed on a 96-well microtiter plate on uropathogenic Escherichia coli (UPEC) at concentrations of 0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100 ppm. The results showed the addition of silver and gold nanoparticles at different concentrations affected and inhibited the growth of UPEC and prevented the formation of biofilms, as indicated by a decrease in the OD value. In conclusion, silver and gold nanoparticles have antibacterial and antibiofilm effects on UPEC. Biofilm ; Microbiology ; Escherichia coli ; Silver nanoparticle ; Antimicrobial ; Chemistry ; Colloidal gold ; Antibiotic resistance ; Bacteria ; Nanoparticle ; Antibiotics ; Nanotechnology ; Biology ; Materials science ; Biochemistry Nanoparticles: synthesis and applications ; Healthcare Quality and Satisfaction ; Urinary Tract Infections Management
Authors: Daria I. Tonkoglazova | Anna V. Gulevskaya | Konstantin A. Chistyakov | О. И. Аскалепова
Source: Beilstein Journal of Organic Chemistry (article, 2021-01-04)
Field: Chemistry — Organic Chemistry

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring Novel carbazole-based [6]helicenes fused with an azine ring (pyridine, pyrazine or quinoxaline) have been prepared through a five-step synthetic sequence in good overall yields. Commercially available 2,3-dihaloazines were used as starting materials. To discern the effect of merging an azine moiety within a helical skeleton, the X-ray structures, UV-vis absorption and fluorescence spectra of the helicenes were investigated and compared to that of the parent carbazole-based [6]helicene (7<i>H</i>-phenanthro[3,4-<i>c</i>]carbazole). Azine ; Carbazole ; Helicene ; Chemistry ; Moiety ; Pyrazine ; Ring (chemistry) ; Quinoxaline ; Fluorescence ; Crystallography ; Pyridine ; Annulation ; Combinatorial chemistry ; Stereochemistry ; Photochemistry ; Molecule ; Organic chemistry Synthesis and Properties of Aromatic Compounds ; Photochromic and Fluorescence Chemistry ; DNA and Nucleic Acid Chemistry
Authors: Md. Abdul Motin | Andreas Steiger‐Thirsfeld | Michael Stöger‐Pollach | Günther Rupprechter
Source: Catalysis Letters (article, 2021-12-06)
Field: Materials Science — Materials Chemistry

Model Catalysis with HOPG-Supported Pd Nanoparticles and Pd Foil: XPS, STM and C2H4 Hydrogenation Abstract A surface science based approach was applied to model carbon supported Pd nanoparticle catalysts. Employing physical vapour deposition of Pd on sputtered surfaces of highly oriented pyrolytic graphite (HOPG), model catalysts were prepared that are well-suited for characterization by X-ray photoelectron spectroscopy (XPS) and scanning tunneling microscopy (STM). Analysis of the HOPG substrate before and after ion-bombardment, and of Pd/HOPG before and after annealing, revealed the number of “nominal” HOPG defects (~ 10 14 cm −2 ) as well as the nucleation density (~ 10 12 cm −2 ) and structural characteristics of the Pd nanoparticles (mean size/height/distribution). Two model systems were stabilized by UHV annealing to 300 °C, with mean Pd particles sizes of 4.3 and 6.8 nm and size/height aspect ratio up to ~ 10. A UHV-compatible flow microreactor and gas chromatography were used to determine the catalytic performance of Pd/HOPG in ethylene (C 2 H 4 ) hydrogenation up to 150 °C under atmospheric pressure, yielding temperature-dependent conversion values, turnover frequencies (TOFs) and activation energies. The performance of Pd nanocatalysts is compared to that of polycrystalline Pd foil and contrasted to Pt/HOPG and Pt foil, pointing to a beneficial effect of the metal/carbon phase boundary, reflected by up to 10 kJ mol −1 lower activation energies for supported nanoparticles. Graphical Abstract Highly oriented pyrolytic graphite ; Nanomaterial-based catalyst ; X-ray photoelectron spectroscopy ; Catalysis ; Nanoparticle ; Nucleation ; Scanning tunneling microscope ; Annealing (glass) ; Materials science ; Analytical Chemistry (journal) ; Chemistry ; FOIL method ; Chemical engineering ; Nanotechnology ; Organic chemistry Catalytic Processes in Materials Science ; nanoparticles nucleation surface interactions ; Catalysts for Methane Reforming