jablonkagroup/rise_ai_scientists huggingface dataset:
Authors: Ben L. Feringa
Source: Advanced Materials (review, 2020-02-25)
Field: Materials Science — Biomaterials

Vision Statement: Materials in Motion At the dawn of a new era of interactive and responsive materials and dynamic molecular systems there is ample opportunity to raise the level of complexity enabling mechanical motion, autonomous behavior, or interactive self-regulatory functions. Some of the major challenges and opportunities are discussed with a brief perspective toward future developments on responsive materials. Perspective (graphical) ; Motion (physics) ; Nanotechnology ; Materials science ; Statement (logic) ; Human–computer interaction ; Engineering ethics ; Systems engineering ; Engineering physics ; Computer science ; Artificial intelligence ; Engineering ; Epistemology Supramolecular Self-Assembly in Materials ; Advanced Materials and Mechanics ; Polydiacetylene-based materials and applications
Authors: Min Yang | Xu Chen | Yuan Su | Haiyan Liu | Hongxing Zhang | Xiangyang Li | Wentao Xu
Source: Frontiers in Chemistry (review, 2020-11-11)
Field: Materials Science — Materials Chemistry

The Fluorescent Palette of DNA-Templated Silver Nanoclusters for Biological Applications Recently years have witnessed a surge in application of DNA-AgNCs in optics, catalysis, sensing, and biomedicine. DNA-templated silver nanoclusters (DNA-AgNCs), as emerging fluorophores, display superior optical performance since their size is close to the Fermi wavelength. DNA-AgNCs possess unique features, including high fluorescence quantum yields and stability, biocompatibility, facile synthesis, and low toxicity, which are requisite for fluorescent probes. The fluorescent emission of DNA-AgNCs can cover the violet to near-infrared (NIR) region by varying the DNA sequences, lengths, and structures or by modifying the environmental factors (such as buffer, pH, metal ions, macromolecular polymers, and small molecules). In view of the above excellent properties, we overview the DNA-AgNCs from the viewpoints of synthesis and fluorescence properties, and summarized its biological applications of fluorescence sensing and imaging. Nanoclusters ; Palette (painting) ; Fluorescence ; Nanotechnology ; DNA ; Materials science ; Chemistry ; Computer science ; Physics ; Biochemistry ; Optics Nanocluster Synthesis and Applications ; Gold and Silver Nanoparticles Synthesis and Applications ; Advanced Nanomaterials in Catalysis
Authors: Aisha Asghar | Naseem Iqbal | Leena Aftab | Tayyaba Nооr | Benson M. Kariuki | Luke Kidwell | Timothy L. Easun
Source: Royal Society Open Science (article, 2020-03-01)
Field: Chemistry — Inorganic Chemistry

Ethylenediamine loading into a manganese-based metal–organic framework enhances water stability and carbon dioxide uptake of the framework Metal-organic frameworks (MOFs) based on 2,5-dihydroxyterepthalic acid (DOBDC) as the linker show very high CO<sub>2</sub> uptake capacities at low to moderate CO<sub>2</sub> pressures; however, these MOFs often require expensive solvent for synthesis and are difficult to regenerate. We have synthesized a Mn-DOBDC MOF and modified it to introduce amine groups into the structure by functionalizing its metal coordination sites with ethylenediamine (EDA). Repeat framework synthesis was then also successfully performed using recycled dimethylformamide (DMF) solvent. Characterization by elemental analysis, FTIR and thermogravimetric studies suggest that EDA molecules are successfully substituting the original metal-bound DMF. This modification not only enhances the material's carbon dioxide sorption capacity, increasing stability to repeated CO<sub>2</sub> sorption cycles, but also improves the framework's stability to moisture. Moreover, this is one of the first amine-modified MOFs that can demonstrably be synthesized using recycled solvent, potentially reducing the future costs of production at larger scales. Sorption ; Ethylenediamine ; Metal-organic framework ; Thermogravimetric analysis ; Manganese ; Solvent ; Fourier transform infrared spectroscopy ; Amine gas treating ; Dimethylformamide ; Materials science ; Chemistry ; Inorganic chemistry ; Chemical engineering ; Adsorption ; Organic chemistry Metal-Organic Frameworks: Synthesis and Applications ; Carbon dioxide utilization in catalysis ; Carbon Dioxide Capture Technologies
Authors: M. Kumar | Shalini Verma | Akhilesh K. Verma
Source: Organic Letters (article, 2020-06-09)
Field: Chemistry — Organic Chemistry

Ru(II)-Catalyzed Oxidative Olefination of Benzamides: Switchable Aza-Michael and Aza-Wacker Reaction for Synthesis of Isoindolinones Selective tandem oxidative C-H olefination-aza-Michael/aza-Wacker reaction of <i>N</i>-arylbenzamides is achieved by fine-tuning between base and additive to access valuable 3-oxoisoindolinyls and 3-oxoisoindolinylidenes, respectively. Careful optimization and control experiments provides a guiding principle in the design of a proposed catalytic cycle. The copper-iminium complex acting as a precursor for the binding of Ru catalyst was isolated and confirmed by X-ray diffraction. The versatility of this catalytic system has been demonstrated by the synthesis of biologically relevant molecules. Iminium ; Chemistry ; Catalysis ; Michael reaction ; Combinatorial chemistry ; Catalytic cycle ; Wacker process ; Tandem ; Oxidative phosphorylation ; Organic chemistry ; Palladium ; Biochemistry Catalytic C–H Functionalization Methods ; Synthesis and Catalytic Reactions ; Oxidative Organic Chemistry Reactions
Authors: Daniel Bůžek | Soňa Ondrušová | Jan Hynek | Petr Kovář | Kamil Lang | Ján Rohlíček | Jan Demel
Source: Inorganic Chemistry (article, 2020-04-10)
Field: Chemistry — Inorganic Chemistry

Robust Aluminum and Iron Phosphinate Metal–Organic Frameworks for Efficient Removal of Bisphenol A Porous metal-organic frameworks (MOFs) have excellent characteristics for the adsorptive removal of environmental pollutants. Herein, we introduce a new series of highly stable MOFs constructed using Fe<sup>3+</sup> and Al<sup>3+</sup> metal ions and bisphosphinate linkers. The isoreticular design leads to ICR-2, ICR-6, and ICR-7 MOFs with a honeycomb arrangement of linear pores, surface areas up to 1360 m<sup>2</sup> g<sup>-1</sup>, and high solvothermal stabilities. In most cases, their sorption capacity is retained even after 24 h of reflux in water. The choice of the linkers allows for fine-tuning of the pore sizes and the chemical nature of the pores. This feature can be utilized for the optimization of host-guest interactions between molecules and the pore walls. Water pollution by various endocrine disrupting chemicals has been considered a global threat to public health. In this work, we prove that the chemical stability and hydrophobic nature of the synthesized series of MOFs result in the remarkable sorption properties of these materials for endocrine disruptor bisphenol A. Chemistry ; Bisphenol A ; Sorption ; Chemical engineering ; Bisphenol ; Porosity ; Endocrine disruptor ; Molecule ; Metal ; Metal ions in aqueous solution ; Chemical stability ; Organic chemistry ; Adsorption ; Epoxy Metal-Organic Frameworks: Synthesis and Applications ; Covalent Organic Framework Applications ; Adsorption and biosorption for pollutant removal
Authors: Sijie Wu | Chengyu Liang | Jiaxu Zhang | Zhou Wu | Xiao‐Li Wang | Rui Zhou | Yaxing Wang | Shuao Wang | Dong‐Sheng Li | Tao Wu
Source: Angewandte Chemie International Edition (article, 2020-08-10)
Field: Materials Science — Materials Chemistry

A Photoconductive X‐ray Detector with a High Figure of Merit Based on an Open‐Framework Chalcogenide Semiconductor Abstract A wide range of tunability in the physical parameters of a semiconductor used for X‐ray detection is desirable to achieve targeted performance optimization. However, in a dense‐phase semiconductor, fine‐tuning one parameter often leads to unwanted changes in other parameters. Herein, the intrinsic openness in an open‐framework semiconductor has been confirmed, for the first time, to be a key structural factor that weakens the mutual exclusivity of the adjustable physical parameters owing to a non‐linear control mechanism. The controllable doping of S in a zeolitic In–Se host results in an optimal balance between resistivity, band gap, and carrier mobility, which finally results in an excellent X‐ray detector with a high figure of merit for the mobility–lifetime product (7.12×10 −4 cm 2 V −1 ); this value is superior to that of a commercial α‐Se detector. The current strategy of choosing open‐framework semiconductor materials opens a new window for targeting high‐performance X‐ray detection. Figure of merit ; Semiconductor ; Optoelectronics ; Materials science ; Detector ; Chalcogenide ; Semiconductor detector ; Doping ; Nanotechnology ; Optics ; Physics 2D Materials and Applications ; Advanced Semiconductor Detectors and Materials ; Chalcogenide Semiconductor Thin Films
Authors: Alastair Little | Alessandro Pellis | James W. Comerford | Edwin Naranjo-Valles | Nema Hafezi | Mark Mascal | Thomas J. Farmer
Source: ACS Sustainable Chemistry & Engineering (article, 2020-09-04)
Field: Materials Science — Biomaterials

Effects of Methyl Branching on the Properties and Performance of Furandioate-Adipate Copolyesters of Bio-Based Secondary Diols Furandioate-adipate copolyesters are an emerging class of bio-based biodegradable polymers with great potential to replace fossil-derived terephthalic acid-based copolyesters such as poly(butylene adipate-<i>co</i>-terephthalate) (PBAT). Furandioate-adipate polyesters have almost exclusively been prepared with conventional primary (1°) alcohol diols, while secondary (2°) alcohol diol monomers have largely been overlooked until now, despite preliminary observations that using methyl-branched diols increases the <i>T</i> <sub>g</sub> of the resultant polyesters. Little is known of what impact the use of 2° alcohol diols has on other properties such as material strength, hydrophobicity, and rate of enzymatic hydrolysis-all key parameters for performance and end-of-life. To ascertain the effects of using 2° diols on the properties of furandioate-adipate copolyesters, a series of polymers from diethyl adipate (DEA) and 2,5-furandicarboxylic acid diethyl ester (FDEE) using different 1° and 2° alcohol diols was prepared. Longer transesterification times and greater excesses of diol (diol/diester molar ratio of 2:1) were found to be necessary to achieve <i>M</i> <sub>w</sub>s > 20 kDa using 2° alcohol diols. All copolyesters from 2° diols were entirely amorphous and exhibited higher <i>T</i> <sub>g</sub>s than their linear equivalents from 1° diols. Compared to linear poly(1,4-butyleneadipate-<i>co</i>-1,4-butylenefurandioate), methyl-branched, poly(2,5-hexamethyleneadipate-<i>co</i>-2,5-hexamethylenefurandioate) (0:7:0.3 furandioate/adipate ratio) displayed both higher modulus (67.8 <i>vs</i> 19.1 MPa) and higher extension at break (89.7 <i>vs</i> 44.5 mm). All other methyl-branched copolyesters displayed lower modulus but retained higher extension at break compared with their linear analogues. Enzymatic hydrolysis studies using <i>Humicola insolens</i> cutinase revealed that copolyesters from 2° alcohol diols have significantly decreased rates of biodegradation than their linear equivalents synthesized using 1° alcohol diols, allowing for fine-tuning of polymer stability. Hydrophobicity, as revealed by water contact angles, was also found to generally increase through the introduction of methyl branching, demonstrating potential for these materials in coatings applications. Adipate ; Diol ; Polyester ; Alcohol ; Transesterification ; Organic chemistry ; Polymer chemistry ; Hydrolysis ; Materials science ; Terephthalic acid ; Chemistry ; Catalysis biodegradable polymer synthesis and properties ; Catalysis for Biomass Conversion ; Carbon dioxide utilization in catalysis
Authors: Grzegorz Czernel | Iwona Budziak-Wieczorek | Anna Oniszczuk | Dariusz Karcz | Katarzyna Pustuła | Andrzej Górecki | Alicja Matwijczuk | Bożena Gładyszewska | Mariusz Gagoś | Andrzej Niewiadomy | Arkadiusz Matwijczuk
Source: Molecules (article, 2020-09-11)
Field: Chemistry — Physical and Theoretical Chemistry

ESIPT-Related Origin of Dual Fluorescence in the Selected Model 1,3,4-Thiadiazole Derivatives In our previous work, we discussed the emergence of the dual fluorescence phenomenon in selected compounds from the group of 1,3,4-thiadiazoles. The results obtained in a number of experimental studies, supported by [TD]DFT calculations, clearly indicated that the phenomenon of dual fluorescence stemmed from an overlap of several factors, including the correct conformation of the analyzed molecule and, very significantly in this context, aggregation effects. Where those two conditions were met, we could observe the phenomenon of intermolecular charge transfer (CT) and the emergence of electronic states responsible for long wave emissions. However, in light of the new studies presented in this paper, we were able, for the first time, to provide a specific theory for the effect of dual fluorescence observed in the analyzed group of 1,3,4-thiadiazoles. We present the results of spectroscopic measurements conducted for two selected analogues from the 1,3,4-thiadiazole group, both in polar and non-polar solvents, which clearly evidence (as we have already suspected in the past, albeit have not shown in publications to date) the possibility of processes related to emission from the tautomer formed in the process of excited state intramolecular proton transfer, which is responsible for the long-wavelength emissions observed in the selected analogues. The presented results obtained with the use of UV-Vis, fluorescence (stationary and time-resolved), FTIR, and Raman spectroscopy, as well as from calculations of dipole moment changes between the ground and excited state with the use of two derivatives with different structures of the resorcylic system, corroborated our standing hypothesis. At the same time, they excluded the presence of ground state keto forms of the analyzed analogues unless necessitated by the structure of the molecule itself. In this case, aggregation factors enhance the observed effects related to the dual fluorescence of the analyzed compounds (by way of AIE-aggregated induced emissions). Intermolecular force ; Fluorescence ; Intramolecular force ; Chemistry ; Excited state ; Context (archaeology) ; Tautomer ; Raman spectroscopy ; Molecule ; Time-dependent density functional theory ; Relaxation (psychology) ; Photochemistry ; Computational chemistry ; Chemical physics ; Density functional theory ; Atomic physics ; Stereochemistry ; Physics ; Organic chemistry Photochemistry and Electron Transfer Studies ; Chemical Reactions and Mechanisms ; Organic Light-Emitting Diodes Research
Authors: Hiroki Moriya | Yuto Takita | Akira Matsumoto | Yuki Yamahata | Megumi Nishimukai | Masao Miyazaki | Hitoshi Shimoi | Sung-Jin Kawai | Miwa Yamada
Source: Frontiers in Bioengineering and Biotechnology (article, 2020-08-25)
Field: Materials Science — Biomaterials

Cobetia sp. Bacteria, Which Are Capable of Utilizing Alginate or Waste Laminaria sp. for Poly(3-Hydroxybutyrate) Synthesis, Isolated From a Marine Environment We isolated the <i>Cobetia</i> sp. strains IU 180733JP01 (5-11-6-3) and 190790JP01 (5-25-4-2) from seaweeds and showed that both strains accumulate poly(3-hydroxybutyrate) [P(3HB)] homopolymer in a nitrogen-limiting mineral salt medium containing alginate as a sole carbon source. Genome sequence analysis of the isolated strains showed that they have putative genes which encode enzymes relevant to alginate assimilation and P(3HB) synthesis, and the putative alginate-assimilating genes formed a cluster. Investigation of the optimum culture conditions for high accumulation of P(3HB) showed that when the 5-11-6-3 strain was cultured in a nitrogen-limiting mineral salt medium (pH 5.0) containing 6% NaCl and 3% (w/v) alginate as a sole carbon source for 2 days, the P(3HB) content and P(3HB) production reached 62.1 ± 3.4 wt% and 3.11 ± 0.16 g/L, respectively. When the 5-25-4-2 strain was cultured in a nitrogen-limiting mineral salt medium (pH 4.0) containing 5% NaCl and 3% (w/v) alginate for 2 days, the P(3HB) content and P(3HB) production reached 56.9 ± 2.1 wt% and 2.67 ± 0.11 g/L, respectively. Moreover, the 5-11-6-3 strain also produced P(3HB) in a nitrogen-limiting mineral salt medium (pH 5.0) containing 6% NaCl and freeze-dried and crushed waste <i>Laminaria</i> sp., which is classified into brown algae and contains alginate abundantly. The resulting P(3HB) content and P(3HB) productivity were 13.5 ± 0.13 wt% and 3.99 ± 0.15 mg/L/h, respectively. Thus, we demonstrated the potential application of the isolated strains to a simple P(3HB) production process from seaweeds without chemical hydrolysis and enzymatic saccharification. Laminaria ; Nitrogen ; Limiting ; Strain (injury) ; Food science ; Chemistry ; Bacteria ; Brown algae ; Salt (chemistry) ; Algae ; Microorganism ; Biochemistry ; Nuclear chemistry ; Botany ; Biology ; Organic chemistry biodegradable polymer synthesis and properties ; Polyamine Metabolism and Applications ; Biopolymer Synthesis and Applications
Authors: Megan C. Wasson | Ken‐ichi Otake | Xinyi Gong | Annabella R. Strathman | Timur İslamoğlu | Nathan C. Gianneschi | Omar K. Farha
Source: CrystEngComm (article, 2020-01-01)
Field: Chemistry — Inorganic Chemistry

Modulation of crystal growth and structure within cerium-based metal–organic frameworks Cerium-based metal–organic frameworks' crystal growth and structure dictated using modulating monocarboxylate species. Cerium ; Metal-organic framework ; Crystal structure ; Materials science ; Metal ; Modulation (music) ; Crystal growth ; Crystal (programming language) ; Inorganic chemistry ; Crystallography ; Chemistry ; Computer science ; Organic chemistry ; Metallurgy ; Physics Metal-Organic Frameworks: Synthesis and Applications ; X-ray Diffraction in Crystallography ; Crystallography and molecular interactions
Authors: Pramila Chaubey | Munira Momin | Sujata Sawarkar
Source: Frontiers in Pharmacology (review, 2020-02-25)
Field: Materials Science — Biomaterials

Significance of Ligand-Anchored Polymers for Drug Targeting in the Treatment of Colonic Disorders Targeted drug delivery into the colon is highly desirable for the treatment of variety of bowel diseases such as ulcerative colitis, Crohn’s disease, colonic cancers, local treatment of colonic pathologies, and systemic delivery of protein/ peptide drugs. Conventional colon targeted drug delivery systems lack specificity and release significant amount of drug much prior to reaching to colon. Hence, colon targeting is still an open question for further research to deliver therapeutics efficiently and effectively to the desirable site. Ligand anchored therapy is a powerful and effective pharmaceutical approach to achieve selective drug delivery to pathological cells, for both therapeutic as well as diagnostic purposes, with the advantage of minimal side effects and toxicity. Active drug targeting strategy is based on the discovery of overexpressed receptors on pathological cells, compared to their expression in normal tissues. Further, drug resistance constitutes the one of the major reasons of the failure of chemotherapy and presents a major obstacle for the effective treatment. The reason behind drug resistance is exposure of pathological cells/ pathogens to sub-therapeutic levels of drugs due lack of specificity of therapeutics. Active targeting, specifically taken up by the target cells, can warrant exposure of pathological cells/ pathogens to high drug load at the target and sparing non-target cells hence minimal damage to normal cells and least chance of drug resistance. A variety of ligands have been investigated including folate, transferrin, antibodies, peptides and aptamers. Multiple functionalities can be incorporated into the design of nanocarriers, to enable imaging and triggered intracellular drug release. The present review article focuses on recent advances in ligand anchored therapy and its significance on the development of targeted nanocarriers and will introduce novel concepts such as multi-targeting and multi-functional nanocarriers in the treatment of colonic disorders. Nanocarriers ; Targeted drug delivery ; Drug ; Drug delivery ; Medicine ; Drug resistance ; Targeted therapy ; Pharmacology ; Ulcerative colitis ; Cancer research ; Disease ; Biology ; Pathology ; Cancer ; Chemistry ; Internal medicine Nanoparticle-Based Drug Delivery ; Advanced Drug Delivery Systems ; Drug Transport and Resistance Mechanisms
Authors: Ke Hu | Renato N. Sampaio | Jenny Schneider | Ludovic Troian‐Gautier | Gerald J. Meyer
Source: Journal of the American Chemical Society (review, 2020-08-20)
Field: Chemistry — Electrochemistry

Perspectives on Dye Sensitization of Nanocrystalline Mesoporous Thin Films Recent advances in our mechanistic understanding of dye-sensitized electron transfer reactions occurring at metal oxide interfaces are described. These advances were enabled by the advent of mesoporous thin films, comprised of anatase TiO<sub>2</sub> nanocrystallites, that are amenable to spectroscopic and electrochemical characterization in unprecedented molecular-level detail. The metal-to-ligand charge transfer (MLCT) excited states of Ru polypyridyl compounds serve as the dye sensitizers. Excited-state injection often occurs on ultrafast time scales with yields that can be tuned from unity to near zero through modification of the sensitizer or the electrolyte composition. Transport of the injected electron and the oxidized sensitizer (hole hopping) are both operative in the composite mechanism for charge recombination between the injected electron and the oxidized sensitizer. Sensitizers that contain a pendant electron donor, as well as core/shell SnO<sub>2</sub>/TiO<sub>2</sub> nanostructures, often prolong the lifetime of the injected electron and provide fundamental insights into adiabatic and nonadiabatic electron transfer mechanisms. Regeneration of the oxidized sensitizer by iodide is enhanced through halogen bonding, orbital pathways, and ion pairing. A substantial ∼10 MV cm<sup>-1</sup> electric field is created by electron injection into TiO<sub>2</sub> nanocrystallites that induces ion migration, reports on the sensitizer dipole orientation, and (in some cases) reorients or flips the sensitizer. Dye-sensitized conductive oxides also promote long-lived charge separation with bias dependent kinetics that provide insights into the reorganization energies associated with electron and proton-coupled electron transfer in the electric double layer. Chemistry ; Electron transfer ; Anatase ; Excited state ; Chemical physics ; Photochemistry ; Mesoporous material ; Dye-sensitized solar cell ; Electrolyte ; Physical chemistry ; Atomic physics ; Electrode ; Organic chemistry Electrochemical Analysis and Applications ; Advanced Photocatalysis Techniques ; TiO2 Photocatalysis and Solar Cells