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Perfluoroalkyl substances (PFAS), known as “forever chemicals,” are a growing concern in the sphere of human and environmental health. In response, rapid, reproducible, and inexpensive methods for PFAS detection in the environment and home water supplies are needed. We have developed a simple and inexpensive perfluoroalkyl acid detection method based on an electrically read lateral flow assay (e-LFA). Our method employs a new fluorous surfactant formulation with undoped polyaniline (F-PANI) fabricated to create test lines for the lateral flow assay. In perfluoroalkyl acid sensing studies, an increase in conductivity of the F-PANI film is caused by acidification and doping of PANI. A conductivity enhancement by 104-fold can be produced by this method and we demonstrate a limit of detection for perfluorooctanoic acid (PFOA) of 400 ppt and perfluorobutanoic acid (PFBA) of 200 ppt. This new method for PFOA detection can be expanded for wide-scale environmental and at-home water testing.

The graphite rods of used batteries have been utilized as source for Graphene Oxide (GO). The Acid Modified Graphene Oxide (AMGO) is loaded with Schiff base obtained from salicylaldehyde and 3-amino phenol. Glassy Carbon Electrode (GCE) surface when modified with the Schiff base loaded AMGO acts as electrochemical sensor for Dopamine (DA) in presence of Uric Acid (UA) and Ascorbic Acid (AA). Cyclic Voltammetry (CV), Square Wave Voltammetry (SWV) and Differential Pulse Voltammetry (DPV) shows well separated peaks for DA from UA and AA. The DA peak intensity increases in the three techniques with DA concentration. The linear range for the detection of dopamine is observed from 9.09 × 10-4 M to 1.70 × 10-3 M in presence of 1.00 × 10-1 M Ascorbic Acid and 1.00 × 10-2 M uric acid. The detection limit is estimated to be 9.38 × 10-10 M.

Bent Core Mesogens are remarkably interesting achiral Liquid Crystals. These grab attention for their utility. The compound, taken for investigation, is a Schiff base addition product, composed of 2-(4?-aminophenyl)-5-(4??-butyloxyphenyl)-1,3,4- thiadiazole and 4-n-hexadecyloxy salicylaldehyde. The property of this imine derivative is in accordance with liquid crystal and is a Bent Core Mesogen (BCM). The thin layers were prepared with the help of Langmuir-Blodgett apparatus. The morphology and photo-physical characteristics of thin films were examined in comparison to similar BCM derivative of 1,3,4-Oxadiazole. The expectation was the formation of monolayer of molecules on the substrate. Practically there were layer of clusters on the substrate. Both molecules form nano clusters. The typically different aggregates by the thiadiazole moiety in comparison to oxadiazole moiety are revealed. Cluster formation is also supported by the Atomic Force Microscopic (AFM) images.

The current study offers a comprehensive understanding on the adsorption study employing the cost-effective biomass as an effective substitute against high-cost treatment options. The present work put forth the adsorption of hazardous cationic dye: Crystal Violet (CV) from aqueous solution using Rice Husk (RH) and surfactant Modified Rice Husk (MRH). Effect of the adsorbents: RH and MRH onto CV removal is determined considering various experimental parameters viz., mass, volume, dye concentration, contact-time, equilibrium temperature, and pH where maximum CV adsorption was achieved at pH = 8. Results obtained are attributed to the favorable ion-pair formation between CV and anionic surfactant: Sodium Dodecyl Sulfate (SDS) which is validated further using quantum chemical calculations. To counterpart the sorption process onto the adsorbent, the adsorption study was validated employing several kinetic models and isotherms. The thermodynamic conduct concluded the CV adsorption to be spontaneous (negative ?G) and endothermic (positive ?H) in characteristic at ambient temperature i.e., adsorption increases with temperature.

This study evaluates the performance of commercial reverse osmosis (RO) and nanofiltration (NF) membranes for the removal of metal ions from synthetic water and surface water carried from the north‐west of Lake Tanganyika in the city of Uvira, in the east of the Democratic Republic of Congo. Metal ion analyses were performed by the standardized ICP‐MS and ICP‐OES methods. The RO membrane showed higher metal ion rejection in high‐concentration solutions (synthetic samples) prepared in the laboratory as well as in low‐concentration samples from real raw water collected near Lake Tanganyika. Rejection levels were higher than 98% for Cr3+, Pb2+, Cd2+, As3+, Ni2+, and Sb+3 ions in the synthetic solutions, and 99.2, 98.8, 98.6, 99.2, 98.4, and 98.8%, respectively, in the real samples. The concentrations of metals in the permeate varied depending on the feed concentration and were 0.15 to 1.02 mg/L, 0.33 to 22 mg/L, and 0.11 to 22 mg/L in RO, NF90, and NF270 membranes, respectively. Regarding the NF membranes, the rejection of Cr, Ni, and Cd ions was interesting: 98.2, 97.8, and 92.3%, respectively. However, it was lower for Pb, As, and Sb ions: 76.9, 52.5 and 64.1%, respectively. The flux of NF was 329 to 375 L/m2.h, much higher than for RO membranes, which had a flux of 98 to 132 L/m2.h. The studied membranes are thus a feasible solution to remove the studied metals from real water sources at low concentrations since they meet the standards of the World Health Organization on specific values assigned to chemicals from industrial sources and human habitation areas where these ions are present in drinking water.

We report herein a rationally designed metal-free ternary heterojunction, namely, black phosphorus quantum dots/ carbon nitride-reduced graphene oxide (BPQDs/CN-rGO), that functions as a photocatalyst in multiple photooxidation reactions including C=C bond cleavage, glycerol oxidation, and C-CF3 bond formation along with the removal of organic pollutants from wastewater. After the characterization of the structure and photophysical properties of BPQDs/CN-rGO heterojunction, it was first tested in the photodegradation of organic pollutants and showed superior performance. The underlying mechanism of BPQDs/CN-rGO in the photodegradation of organic pollutants revealed that the created internal electric field (IEF) among the components and photogenerated species (h+ and O-2(center dot-)) are attributed to superior activity. Prompted by these results, the BPQDs/CN-rGO photocatalyst was applied in other photooxidation reactions. The nonclassical-type-II heterojunction structure generates active species (O-2(center dot-), h(+), O-1(2)) under visible light irradiation, enabling the selective oxidation of glycerol to glyceric acid and C=C bond cleavage along with highly challenging Langlois reagent to heteroarenes., Scientific and Technological Research Council of Turkey (TÜBİTAK); Ph.D. Scholarship; Turkish Academy of Sciences (TU?BA); Council of Higher Education (YÖK)

Hydrogen sulfide (H2S) as a critical messenger molecule plays vital roles in regular cell function. However, abnormal levels of H2S, especially mitochondrial H2S, are directly correlated with the formation of pathological states including neurodegenerative diseases, cardiovascular disorders, and cancer. Thus, monitoring fluxes of mitochondrial H2S concentrations both in vitro and in vivo with high selectivity and sensitivity is crucial. In this direction, herein we developed the first ever example of a mitochondria-targeted and H2S-responsive new generation 1,2-dioxetane-based chemiluminescent probe (MCH). Chemiluminescent probes offer unique advantages compared to conventional fluorophores as they do not require external light irradiation to emit light. MCH exhibited a dramatic turn-on response in its luminescence signal upon reacting with H2S with high selectivity. It was used to detect H2S activity in different biological systems ranging from cancerous cells to human serum and tumor-bearing mice. We anticipate that MCH will pave the way for development of new organelle-targeted chemiluminescence agents towards imaging of different analytes in various biological models., Scientific and Technological Research Council of Turkey (TÜBİTAK)

In pristine graphitic carbon nitride (g-CN), amino groups often function as structural defects that trap photogenerated charges, resulting in low photocatalytic activity as well as reaction with nitrite, aldehyde, etc., ensuing in poor product yield. Without significantly altering the optical characteristics, the removal of amino groups is necessary to increase the photocatalytic activity and structural stability of pristine g-CN. The deamino graphitic carbon nitride (DA-gCN-5) was prepared by tert-butyl nitrite (TBN)treatment, characterized and used as a photocatalyst for the radical C-H arylation of heteroarenes using anilines as radical source. Indeed, the photophysical characteristics of DA-gCN-5 and those of pristine g-CN are very comparable, except that DA-gCN-5 has a fewer residual amino groups, higher crystallinity, and compressed structure with a different morphology. Moreover, DA-gCN-5- catalyzed C-H arylation reaction offers greater product yield in a shorter reaction time compared to that of pristine g-CN in the coupling between heteroarenes and the in situ generated aryl diazonium salts from anilines under visible light irradiation. The amino groups in pristine g-CN absorbed the TBN that was added to convert aniline into the appropriate diazonium ions during the reaction. As a result, deamino graphitic carbon nitride produced by chemical treatment has better photophysical properties and catalytic activity than pristine g-CN. Additionally, this is the first method that uses diazotization reaction for the preparation of deamino graphitic carbon nitride, as far as we are aware., Scientific and Technological Research Council of Turkey (TÜBİTAK); European Commission (EC); European Union (EU); Horizon 2020; BİDEB Co-Funded Brain Circulation Program; TÜBİTAK PhD Scholarship

N-doped carbon quantum dots (N-CQDs) derived from the Rumex crispus L. plant were incorporated into TiO2 via a facile hydrothermal method. Asprepared materials were characterized and used in the photocatalytic tetracycline (TC) degradation under UVA light irradiation by examining several operational parameters involving the N-CQDs amount, initial TC concentration, pH, and photocatalytic reaction time. XRD analysis revealed the conversion of the rutile phase to the anatase phase after the incorporation of N-CQDs into the TiO2 structure. The results revealed that the N-CQDs/TiO2 photocatalysts demonstrated the highest efficiency in TC degradation compared to other processes of adsorption, photolysis (UVA), and photocatalysis with TiO2 (TiO2/UVA). Under optimized conditions, 10 mg/L TC at pH 5.15 with 0.2 g/L N-CQDs/TiO2 catalyst showed 97.7% photocatalytic degradation for 120 min under UVA irradiation. The formation of an S-scheme heterojunction between N-CQDs and TiO2 provided enhanced charge separation and strong redox capability, causing significant improvement in the photocatalytic performance of N-CQDs/TiO2. Trapping experiments showed that O-2(-) and h(+) are the predominant reactive species for the TC elimination in an aqueous solution., The authors would like to express special thanks to Ataturk University for the financial support (Project of FDK-2021-9201) and the East Anatolia High Technology Application and Research Center (DAYTAM) for technical support for the materials characterization. This work is a chapter in the Ph.D. thesis of M.K.

Black phosphorus (BP) has recently emerged as a versatile photocatalyst owing to its unique photophysical properties and tunable bandgap. Nonetheless, the rapid recombination of the photogenerated charges of pristine BP samples has significantly hindered its practical applications in photocatalysis. Herein, we report, for the first time, the effect of transition metal nanoparticles (Ni and Co) as co-catalysts on the photocatalytic activity of BP/tungsten disulfide (WS2) binary heterojunctions (BP/WS2-TM (TM: Ni, Co)) in the hydrogen evolution reaction (HER) under visible light irradiation (& lambda; > 420 nm). Ternary heterojunctions named BP/WS2-TM (TM: Ni, Co) were synthesized via a chemical reduction method, leading to the formation of an S-scheme heterojunction, in which BP acts as a reduction catalyst and WS2 serves as an oxidation catalyst. BP/WS2-Ni and BP/WS2-Co performed substantial amounts of hydrogen generation of 9.53 mmol h(-1)g(-1) and 12.13 mmol h(-1)g(-1), respectively. Moreover, BP/WS2-Co exhibited about 5 and 15 times higher photocatalytic activity compared to the binary BP/WS2 heterojunctions and pristine BP, respectively. The enhanced photocatalytic activity of the heterojunction catalysts is attributed to the extended light absorption ability, enhanced charge separation, and larger active sites. This study is the first example of photocatalytic hydrogen evolution from water by using Ni- and Co-doped binary BP/WS2 heterojunctions., Scientific and Technological Research Council of Turkey (TÜBİTAK); Selcuk University Scientific Research Projects

Antioksidan merupakan senyawa yang dapat mencegah atau menghambat oksidasi molekul lain, yang pada makhluk hidup berperan dalam mempertahankan pertumbuhan dan metabolisme yang normal. Studi aktivitas antioksidan individual pada senyawa dari jeruk nipis telah dilakukan. Senyawa yang dipelajari difokuskan pada bergamottin, citropten dan asam klorogenat. Tujuan dari penelitian ini adalah mempelajari hubungan antara struktur molekul dengan aktivitas antioksidannya melalui perhitungan secara kimia komputasi potensial ionisasi, electrodonating power, dan net electrophilicity. Seluruh perhitungan dilakukan menggunakan program komputasi Gaussian 09 Revision D.01, pada level teori APFD/6-31+G(d) pada keadaan muatan netral (deprotonasi, negatif), positif (netral), dan negatif (negatif dua). Hasil yang diperoleh menunjukkan bahwa citropten dan asam klorogenat berpotensi sebagai antioksidan. Vitamin C, asam galat, dan asam klorogenat dalam keadaan terdeprotonasi memiliki sifat antioksidan yang lebih kuat daripada keadaan netral. Analisis ADMET menunjukkan bahwa bergamottin, citropten dan asam klorogenat mampu menghambat enzim sitokrom P450 sehingga dapat pula meningkatkan bioavailabilitas antioksidan, maka bergamottin, citropten dan asam klorogenat dapat pula berperan tidak langsung terhadap aktivitas antioksidan.

The mechanisms of larval fish transport have been rigorously studied in the past several decades, building foundational knowledge of key biological and environmental factors with which to inform decisions about species management. This study has been built upon information gained from previous studies to further elucidate the processes involved at the recruitment stage of larval fishes. Vertical swimming behaviors of larval fishes enable deliberate orientation within the water column to allow organisms of limited mobility greater control over their horizontal movements. Vertical accumulation patterns of larvae are found to be tightly dependent on the strength of stratification within the water column at nursery entrances, such as estuaries. Onshore currents, such as upwelling and surface intrusions, are found to be conduits for entry into these systems. This study observed and analyzed the influence of intrusions by the Gulf Stream into the Fort Pierce Inlet and the vertical accumulation patterns of late-stage larvae associated with those events. This study incorporated a well-established zooplanktonic abundance sampling technique to achieve two primary goals: (1) to analyze the vertical abundances of larval fishes in stratified flow during Gulf Stream intrusions and (2) to assess the correlation between larval influx and intrusion events. The results of this study show a significant and positive correlation between propagule pressure of larval fishes and incidence of Gulf Stream intrusion events. Whereas previous studies have primarily described the spatiotemporal aspects of larval transport in a broader sense, our findings revealed a greater layer of complexity in the mechanisms of transport by incorporating localized hydrographic features. The information gleaned from these results can inform the ecological considerations of future fisheries management and study efforts via additional understanding about the role of physical oceanographic events in a critical lif, 2023, Includes bibliography., Degree granted: Thesis (MS)--Florida Atlantic University, 2023., Collection: FAU Electronic Theses and Dissertations Collection

This work encompasses the synthesis, analysis, and optimization of [3.2.1] all-carbon bridged bicyclic compounds, known as resveramorphs (RVM), Studies were conducted using a Caenorhabditis elegans model, where RVMs were tested for antiseizure capabilities. In both applications, RVMs proved potent with activities in the sub-nanomolar level in one case. A structure-activity relationship (SAR) was hypothesized for the identification of the pharmacophore. The six to seven step synthesis route towards the RVM analogues is discussed in further detail. The bicyclization of the RVMs is achieved through a reductive aldol reaction. The reaction suffers from selectivity issues leading to multiple bicyclic products. By following a one-factor-at-a-time (OFAT) methodology, attempts at optimization for this reaction were made, however, despite important gains, the overall yields of the bicyclic product remain low. Other products from this reaction have been used to understand the reaction mechanism, which will be the basis for future efforts to further optimize this key step., 2023, Includes bibliography., Degree granted: Thesis (MS)--Florida Atlantic University, 2023., Collection: FAU Electronic Theses and Dissertations Collection

The emergence of multidrug-resistant bacteria as a global health threat has necessitated the exploration of alternative treatments to combat bacterial infections. Among these, photocatalytic nanomaterials such as quantum dots (QDs) have shown great promise and type-I QDs have been investigated thus far. In this study, we introduce type-II InP/ZnO core/shell QDs that are ligand-exchanged with a short-chain inorganic sulfide ion (S2−) for antibacterial activity. Interestingly, InP/ZnO QDs simultaneously generate reactive oxygen species (ROS) including hydroxyl (•OH) and superoxide (O2•−) radicals, while only O2•− radicals can be released by the type-I sulfide-capped InP/ZnS QDs. The optimized nanostructure achieved effective inhibition of Pseudomonas aeruginosa and Escherichia coli bacteria growth to the level of 99.99% and 70.31% under low-intensity green light illumination of 5 mW.cm−2. Our findings highlight the importance of type-II QDs as a new avenue for developing effective antibacterial agents against drug-resistant pathogens., European Union (EU); Horizon 2020; Research and Innovation Programme; Marie SKŁODOWSKA-CURIE; STIMULUS

Laser processing of diamond has become an important technique for fabricating next generation microelectronic and quantum devices. However, the realization of low taper, high aspect ratio structures in diamond remains a challenge. We demonstrate the effects of pulse energy, pulse number and irradiation profile on the achievable aspect ratio with 532 nm nanosecond laser machining. Strong and gentle ablation regimes were observed using percussion hole drilling of type Ib HPHT diamond. Under percussion hole drilling a maximum aspect ratio of 22:1 was achieved with 10,000 pulses. To reach aspect ratios on average 40:1 and up to 66:1, rotary assisted drilling was employed using > 2 M pulse accumulations. We additionally demonstrate methods of obtaining 0.1° taper angles via ramped pulse energy machining in 10:1 aspect ratio tubes. Finally, effects of laser induced damage are studied using confocal Raman spectroscopy with observation of up to 36% increase in tensile strain following strong laser irradiation. However, we report that upon application of 600 °C heat treatment, induced strain is reduced by up to ~ 50% with considerable homogenization of observed strain.

4H-Pyrazoles are emerging as useful click reagents.

The synthetic studies of ondansetron by a multi-platform, built-for-purpose approach were presented. The studies highlighted the complementary strengths of batch and flow approaches to API synthesis.

In photosynthesis, absorbed light energy transfers through a network of antenna proteins with near-unity quantum efficiency to reach the reaction center, which initiates the downstream biochemical reactions. While the energy transfer dynamics within individual antenna proteins have been extensively studied over the past decades, the dynamics between the proteins are poorly understood due to the heterogeneous organization of the network. Previously reported timescales averaged over such heterogeneity, obscuring individual interprotein energy transfer steps. Here, we isolated and interrogated interprotein energy transfer by embedding two variants of the primary antenna protein from purple bacteria, light-harvesting complex 2 (LH2), together into a near-native membrane disc, known as a nanodisc. We integrated ultrafast transient absorption spectroscopy, quantum dynamics simulations, and cryogenic electron microscopy to determine interprotein energy transfer timescales. By varying the diameter of the nanodiscs, we replicated a range of distances between the proteins. The closest distance possible between neighboring LH2, which is the most common in native membranes, is 25 Å and resulted in a timescale of 5.7 ps. Larger distances of 28 to 31 Å resulted in timescales of 10 to 14 ps. Corresponding simulations showed that the fast energy transfer steps between closely spaced LH2 increase transport distances by ∼15%. Overall, our results introduce a framework for well-controlled studies of interprotein energy transfer dynamics and suggest that protein pairs serve as the primary pathway for the efficient transport of solar energy.

NMR isotope shifts occur due to small differences in nuclear shielding when nearby atoms are different isotopes. For molecules dissolved in 1:1 H2O:D2O, the resulting mixture of N-H and N-D isotopes leads to a small splitting of resonances from adjacent nuclei. We used multidimensional NMR to measure isotope shifts for the proteins CUS-3iD and CspA. We observed four-bond 4∆N(ND) isotope shifts in high-resolution 2D 15N-TROSY experiments of the perdeuterated proteins that correlate with the torsional angle psi. Three-bond 3∆C’(ND) isotope shifts detected in H(N)CO spectra correlate with the intraresidue H-O distance, and to a lesser extent with the dihedral angle phi. The conformational dependence of the isotope shifts agree with those previously reported in the literature. Both the 4∆N(ND) and 3∆C’(ND) isotope shifts are sensitive to distances between the atoms giving rise to the isotope shifts and the atoms experiencing the splitting, however, these distances are strongly correlated with backbone dihedral angles making it difficult to resolve distance from stereochemical contributions to the isotope shift. H(NCA)CO spectra were used to measure two-bond 2∆C’(ND) isotope shifts and [D]/[H] fractionation factors. Neither parameter showed significant differences for hydrogen-bonded sites, or changes over a 25° temperature range, suggesting they are not sensitive to hydrogen bonding. Finally, the quartet that arises from the combination of 2∆C’(ND) and 3∆C’(ND) isotope shifts in H(CA)CO spectra was used to measure synchronized hydrogen exchange for the sequence neighbors A315-S316 in the protein CUS-3iD. In many of our experiments we observed minor resonances due to the 10% D2O used for the sample deuterium lock, indicating isotope shifts can be a source of spectral heterogeneity in standard NMR experiments. We suggest that applications of isotope shifts such as conformational analysis and correlated hydrogen exchange could benefit from the larger magnetic fiel

AbstractExceeding the energy density of lithium−carbon monofluoride (Li−CFx), today's leading Li primary battery, requires an increase in fluorine content (x) that determines the theoretical capacity available from C−F bond reduction. However, high F‐content carbon materials face challenges such as poor electronic conductivity, low reduction potentials (<1.3 V versus Li/Li+), and/or low C−F bond utilization. This study investigates molecular structural design principles for a new class of high F‐content fluoroalkyl‐aromatic catholytes that address these challenges. A polarizable conjugated system—an aromatic ring with an alkene linker—functions as electron acceptor and redox initiator, enabling a cascade defluorination of an adjacent perfluoroalkyl chain (RF = −CnF2n+1). The synthesized molecules successfully overcome premature deactivation observed in previously studied catholytes and achieve close‐to‐full defluorination (up to 15/17 available F), yielding high gravimetric capacities of 748 mAh g−1fluoroalkyl‐aromatic and energies of 1785 Wh kg−1fluoroalkyl‐aromatic. The voltage compatibility between fluoroalkyl‐aromatics and CFx enables design of hybrid cells containing C−F redox activity in both solid and liquid phases, with a projected enhancement of Li–CFx gravimetric energy by 35% based on weight of electrodes+electrolyte. With further improvement of cathode architecture, these “liquid CFx” analogues are strong candidates for exceeding the energy limitations of today's primary chemistries.

Here, we investigate the band structure, density of states, photocatalytic activity, and heterojunction mechanism of WS2 with CeO2 (CeO2@WS2) as a photoactive heterostructure. In this heterostructure, CeO2's growth within WS2 layers is achieved through ultrasonicating WS2 and intercalating CeO2's precursor within the WS2 interlayers, followed by hydrothermal treatment. Through a set of density functional calculations, we demonstrate that CeO2 and WS2 form an interface through a covalent bonding that can be highly stable. The electrochemical impedance spectroscopy (EIS) found that the CeO2@WS2 heterostructure exhibits a remarkably higher conductivity (22.23 mS cm(-2)) compared to either WS2 and CeO2, assignable to the interface in CeO2@WS2. Furthermore, in a physically mixed CeO2-WS2 where the interaction between particles is noncovalent, the resistance was significantly higher (0.67 mS cm(-2)), confirming that the heterostructure in the interface is covalently bonded. In addition, Mott-Schottky and the bandgap measurements through Tauc plots demonstrate that the heterojunction in CeO2 and WS2 is type II. Eventually, the CeO2@WS2 heterostructure indicated 446.7 mu mol g(-1) CO2 generation from photocatalytic oxidation of a volatile organic compound (VOC), formic acid, compared to WS2 and CeO2 alone., University of Tabriz and the National Institute for Materials Science (NIMS); Scientific and Technological Research Council of Turkey (TÜBİTAK); European Union (EU); Horizon 2020; Marie Sklodowska-Curie Individual Fellowship; Co-Funded Brain Circulation Program

Tau, a microtubule-associated protein, is involved in more than 20 different tauopathic disorders characterized by aberrant intracellular aggregation of tau in the brain. However, it is still unclear how this highly soluble tau protein aggregates inside the brain. Thus, understanding the mechanistic details of tau aggregation is critical for unraveling the underlying pathology of tauopathies and developing effective strategies to inhibit tau aggregation. Herein, we investigated the aggregation of a novel 20-residue model peptide, tau₂₉₈₋₃₁₇, derived from the key microtubule-binding domain of the full sequence tau. Our study demonstrates that tau₂₉₈₋₃₁₇ highly mimics full-length tau's physical and aggregation properties. The fibrillation of the peptide is strongly dependent on external factors. The presence of polyanionic heparin (Hep) significantly promotes the aggregation of this peptide to form amyloid fibrils. The Hep-induced aggregation is sensitive to the ionic strength of the solution, suggesting an important role of electrostatic interactions in the mechanism of Hep-mediated aggregation. In addition, two positively charged polysaccharides, chitosan (CHT) and its quaternary derivative N-trimethyl chitosan (TMC), effectively inhibit Hep-induced aggregation of tau₂₉₈₋₃₁₇ in a concentration-dependent manner. Attractive electrostatic interactions between the positively charged moieties in CHT/TMC and the negatively charged residues of Hep play a critical role in inhibiting Hep–peptide interactions and suppressing peptide aggregation., 2023, Includes bibliography., Degree granted: Dissertation (PhD)--Florida Atlantic University, 2023., Collection: FAU Electronic Theses and Dissertations Collection

Cu(I) from tetrakis(acetonitrile)copper(I) hexafluorophosphate ([Cu(MeCN)4]PF6) was complexed with five structurally related phosphines containing N-heterocycles. The interactions between the resulting complexes and some N-nitrosamines were studied using X-ray crystallography as well as emission spectroscopy. Upon complexation, three phosphine ligands bridge two Cu(I) centers to give paddlewheel type structures that displayed a range of emission wavelengths spanning the visible region. N-Nitrosodimethylamine (NDMA) was shown to coordinate to one of the two copper centers in some of the paddlewheel complexes in the solid state and this interaction also quenches their emissions in solution. The influence of the weakly coordinating anion on crystal and spectroscopic properties of one of the paddlewheel complexes was also examined using tetrakis(acetonitrile)copper(I) perchlorate ([Cu(MeCN)4]ClO4) as an alternative Cu(I) source. Similarly, copper(II) perchlorate hexahydrate (Cu(ClO4)2·6H2O) was used for complexation to observe the impact of metal oxidation state on the two aforementioned properties. Lastly, the spectroscopic properties of the complex between Ph2P(1-Isoquinoline) and Cu(I) was shown to exhibit solvent dependence when the counterion is ClO4−. These Cu(I) complexes are bench stable solids and may be useful materials for developing a fluorescence based detection method for N-nitrosamines.

Pluripotent stem (PS) cells enable the scalable production of tissue-specific derivatives with therapeutic potential for various clinical applications, including muscular dystrophies. Given the similarity to human counterparts, the non-human primate (NHP) is an ideal preclinical model to evaluate several questions, including delivery, biodistribution, and immune response. While the generation of human-induced PS (iPS)-cell-derived myogenic progenitors is well established, there have been no data for NHP counterparts, probably due to the lack of an efficient system to differentiate NHP iPS cells towards the skeletal muscle lineage. Here, we report the generation of three independent Macaca fascicularis iPS cell lines and their myogenic differentiation using PAX7 conditional expression. The whole-transcriptome analysis confirmed the successful sequential induction of mesoderm, paraxial mesoderm, and myogenic lineages. NHP myogenic progenitors efficiently gave rise to myotubes under appropriate in vitro differentiation conditions and engrafted in vivo into the TA muscles of NSG and FKRP-NSG mice. Lastly, we explored the preclinical potential of these NHP myogenic progenitors in a single wild-type NHP recipient, demonstrating engraftment and characterizing the interaction with the host immune response. These studies establish an NHP model system through which iPS-cell-derived myogenic progenitors can be studied.

Environmental enteropathy (EE) is a subclinical condition of the small intestine that is highly prevalent in low- and middle-income countries. It is thought to be a key contributing factor to childhood malnutrition, growth stunting, and diminished oral vaccine responses. Although EE has been shown to be the by-product of a recurrent enteric infection, its full pathophysiology remains unclear. Here, we mapped the cellular and molecular correlates of EE by performing high-throughput, single-cell RNA-sequencing on 33 small intestinal biopsies from 11 adults with EE in Lusaka, Zambia (eight HIV-negative and three HIV-positive), six adults without EE in Boston, United States, and two adults in Durban, South Africa, which we complemented with published data from three additional individuals from the same clinical site. We analyzed previously defined bulk-transcriptomic signatures of reduced villus height and decreased microbial translocation in EE and showed that these signatures may be driven by an increased abundance of surface mucosal cells—a gastric-like subset previously implicated in epithelial repair in the gastrointestinal tract. In addition, we determined cell subsets whose fractional abundances associate with EE severity, small intestinal region, and HIV infection. Furthermore, by comparing duodenal EE samples with those from three control cohorts, we identified dysregulated WNT and MAPK signaling in the EE epithelium and increased proinflammatory cytokine gene expression in a T cell subset highly expressing a transcriptional signature of tissue-resident memory cells in the EE cohort. Together, our work elucidates epithelial and immune correlates of EE and nominates cellular and molecular targets for intervention.

Symbiotic partnerships with rhizobial bacteria enable legumes to grow without nitrogen fertilizer because rhizobia convert atmospheric nitrogen gas into ammonia via nitrogenase. After Sinorhizobium meliloti penetrate the root nodules that they have elicited in Medicago truncatula, the plant produces a family of about 700 nodule cysteine-rich (NCR) peptides that guide the differentiation of endocytosed bacteria into nitrogen-fixing bacteroids. The sequences of the NCR peptides are related to the defensin class of antimicrobial peptides, but have been adapted to play symbiotic roles. Using a variety of spectroscopic, biophysical and biochemical techniques, we show here that the most extensively characterized NCR peptide, 24 amino acid NCR247, binds haem with nanomolar affinity. Bound haem molecules and their iron are initially made biologically inaccessible through the formation of hexamers (6 haem/6 NCR247) and then higher-order complexes. We present evidence that NCR247 is crucial for effective nitrogen-fixing symbiosis. We propose that by sequestering haem and its bound iron, NCR247 creates a physiological state of haem deprivation. This in turn induces an iron-starvation response in rhizobia that results in iron import, which itself is required for nitrogenase activity. Using the same methods as for L-NCR247, we show that the D-enantiomer of NCR247 can bind and sequester haem in an equivalent manner. The special abilities of NCR247 and its D-enantiomer to sequester haem suggest a broad range of potential applications related to human health.

Human calprotectin (CP, S100A8/S100A9 oligomer) is an abundant neutrophil protein that contributes to innate immunity by sequestering nutrient metal ions in the extracellular space. This process starves invading microbial pathogens of essential metal nutrients, which can inhibit growth and colonization. Over the past decade, fundamental and clinical studies have revealed that the S100A8 and S100A9 subunits of CP exhibit a variety of post-translational modifications (PTMs). This review summarizes PTMs on the CP subunits that have been detected and highlights two recent studies that evaluated the structural and functional consequences of methionine and cysteine oxidation on CP. Collectively, these investigations indicate that the molecular speciation of extracellular CP is complex and composed of multiple proteoforms. Moreover, PTMs may impact biological function and the lifetime of the protein. It is therefore important that post-translationally modified CP species receive consideration and integration into the current working model for how CP functions in nutritional immunity.

Virtual high-throughput screening (VHTS) and machine learning (ML) with density functional theory (DFT) suffer from inaccuracies from the underlying density functional approximation (DFA). Many of these inaccuracies can be traced to the lack of derivative discontinuity that leads to a curvature in the energy with electron addition or removal. Over a dataset of nearly one thousand transition metal complexes typical of VHTS applications, we computed and analyzed the average curvature (i.e., deviation from piecewise linearity) for 23 density functional approximations spanning multiple rungs of “Jacob's ladder”. While we observe the expected dependence of the curvatures on Hartree-Fock exchange, we note limited correlation of curvature values between different rungs of “Jacob's ladder”. We train ML models (i.e., artificial neural networks or ANNs) to predict the curvature and the associated frontier orbital energies for each of these 23 functionals and then interpret differences in curvature among the different DFAs through analysis of the ML models. Notably, we observe spin to play a much more important role in determining the curvature of range-separated and double hybrids in comparison to semi-local functionals, explaining why curvature values are weakly correlated between these and other families of functionals. Over a space of 187.2k hypothetical compounds, we use our ANNs to pinpoint DFAs for which representative transition metal complexes have near-zero curvature with low uncertainty, demonstrating an approach to accelerate screening of complexes with targeted optical gaps.

Herein is reported the structural characterization and scalable preparation of the elusive iron–phosphido complex FpP(t Bu)(F) (2-F, Fp = (Fe(h5 -C5H5)(CO)2)) and its precursor FpP(t Bu)(Cl) (2-Cl) in 51% and 71% yields, respectively. These phosphide complexes are proposed to be relevant to an organoiron catalytic cycle for phosphinidene transfer to electron-deficient alkenes. Examination of their properties led to the discovery of a more efficient catalytic system involving the simple, commercially available organoiron catalyst Fp2. This improved catalysis also enabled the preparation of new phosphiranes with high yields ( t BuPCH2CHR; R = CO2Me, 41%; R = CN, 83%; R = 4-biphenyl, 73%; R = SO2Ph, 71%; R = POPh2, 70%; R = 4-pyridyl, 82%; R = 2-pyridyl, 67%; R = PPh3 +, 64%) and good diastereoselectivity, demonstrating the feasibility of the phosphinidene group-transfer strategy in synthetic chemistry. Experimental and theoretical studies suggest that the original catalysis involves 2-X as the nucleophile, while for the new Fp2-catalyzed reaction they implicate a diiron–phosphido complex Fp2(Pt Bu), 4, as the nucleophile which attacks the electron-deficient olefin in the key first P–C bond-forming step. In both systems, the initial nucleophilic attack may be accompanied by favorable five-membered ring formation involving a carbonyl ligand, a (reversible) pathway competitive with formation of the three-membered ring found in the phosphirane product. A novel radical mechanism is suggested for the new Fp2-catalyzed system.

PolyMOFs prepared from mixtures of multivalent polymer linkers and free linkers display tunable surface areas and improved CO2 uptake compared to native MOF-5 and polyMOF-5.

N-Nitrosamines are found in food, drugs, air, water, and soil. They pose a significant risk to human health because of their carcinogenicity; consequently, materials that can be used to selectively and sensitively detect nitrosamines are needed. In this work, we designed and synthesized two polymers bearing calix[4]arene or 4-tert-butylcalix[4]arene tungsten-imido complexes (PCalixH and PCalixtBu) as N-nitrosodimethylamine (NDMA) receptors. The interaction between metallocalix[4]arene monomers/polymers and NDMA was confirmed by 1H NMR and IR spectroscopy. Single-crystal X-ray analysis further revealed that the host-guest interaction is based on binding of the terminal oxygen of NDMA to tungsten within the calixarene cavity. Gravimetric detection of NDMA was performed on a quartz crystal microbalance (QCM) in air. Both polymers show responses to NDMA, with PCalixtBu exhibiting a low theoretical limit of detection of 5 ppb for NDMA. The sensor also shows high selectivity toward NDMA and moderate humidity tolerance. This work provides a sensitive sensor for detection of NDMA and also offers a class of new, selective, and efficient NDMA receptors for the future design of NDMA sensors and NDMA extraction materials.

Mobile zinc is an abundant transition metal ion in the central nervous system, with pools of divalent zinc accumulating in regions of the brain engaged in sensory perception and memory formation. Here, we present essential tools that we developed to interrogate the role(s) of mobile zinc in these processes. Most important are (a) fluorescent sensors that report the presence of mobile zinc and (b) fast, Zn-selective chelating agents for measuring zinc flux in animal tissue and live animals. The results of our studies, conducted in collaboration with neuroscientist experts, are presented for sensory organs involved in hearing, smell, vision, and learning and memory. A general principle emerging from these studies is that the function of mobile zinc in all cases appears to be downregulation of the amplitude of the response following overstimulation of the respective sensory organs. Possible consequences affecting human behavior are presented for future investigations in collaboration with interested behavioral scientists.

We report a metal-organic framework (MOF) with a rare two-dimensional (2D) secondary building unit (SBU). The SBU comprises mixed-valent Fe2+ and Fe3+ metal ions bridged by oxygen atoms pertaining to the polytopic ligand 3,3',4,4',5,5'-hexahydroxybiphenyl, which also define the iron-oxide 2D layers. Overall, the anionic framework exhibits rare topology and evidences strong electronic communication between the mixed-valence iron sites. These results highlight the importance of dimensionality control of MOF SBUs for discovering new topologies in reticular chemistry, and especially for improving electronic communication within the MOF skeleton.

Iron-sulfur clusters are well-established targets in biological nitric oxide (NO) chemistry, but the key intermediate in these processes-a mononitrosylated [Fe4 S4 ] cluster-has not been fully characterized in a protein or a synthetic model thereof. Here, we report the synthesis of a three-member redox series of isostructural mononitrosylated [Fe4 S4 ] clusters. Mononitrosylation was achieved by binding NO to a 3 : 1 site-differentiated [Fe4 S4 ]+ cluster; subsequent oxidation and reduction afforded the other members of the series. All three clusters feature a local high-spin Fe3+ center antiferromagnetically coupled to 3 [NO]- . The observation of an anionic NO ligand suggests that NO binding is accompanied by formal electron transfer from the cluster to NO. Preliminary reactivity studies with the monocationic cluster demonstrate that exposure to excess NO degrades the cluster, supporting the intermediacy of mononitrosylated intermediates in NO sensing/signaling.

To accelerate the exploration of chemical space, it is necessary to identify the compounds that will provide the most additional information or value. A large-scale analysis of mononuclear octahedral transition metal complexes deposited in an experimental database confirms an under-representation of lower-symmetry complexes. From a set of around 1000 previously studied Fe(II) complexes, we show that the theoretical space of synthetically accessible complexes formed from the relatively small number of unique ligands is significantly (∼816k) larger. For the properties of these complexes, we validate the concept of ligand additivity by inferring heteroleptic properties from a stoichiometric combination of homoleptic complexes. An improved interpolation scheme that incorporates information about cis and trans isomer effects predicts the adiabatic spin-splitting energy to around 2 kcal/mol and the HOMO level to less than 0.2 eV. We demonstrate a multi-stage strategy to discover leads from the 816k Fe(II) complexes within a targeted property region. We carry out a coarse interpolation from homoleptic complexes that we refine over a subspace of ligands based on the likelihood of generating complexes with targeted properties. We validate our approach on nine new binary and ternary complexes predicted to be in a targeted zone of discovery, suggesting opportunities for efficient transition metal complex discovery.

Misfolding and aggregation of Cellular Prion Protein (PrPc) is a major molecular process involved in the pathogenesis of Prion diseases. An N-terminal portion of the Prion protein, PrP106-128, is a 23-residue peptide fragment characterized by an amphipathic structure with two domains: a hydrophilic N-terminal domain and a hydrophobic C-terminal domain. Here, we studied the aggregation properties of the prion fragment peptide PrP106-128. The results show that the peptide aggregates in a concentration-dependent manner in an aqueous solution and that the aggregation is sensitive to pH and the preformed amyloid seeds.Furthermore, we show that the zwitterionic POPC liposomes moderately inhibit the aggregation of PrP(106–128), whereas POPC/cholesterol (8:2) vesicles facilitate peptide aggregation likely due to the increase of the lipid packing order and membrane rigidity in the presence of cholesterol. In addition, anionic lipid vesicles of POPG and POPG/cholesterol above a certain concentration accelerate the aggregation of the peptide remarkably. The strong electrostatic interactions between the N-terminal region of the peptide and POPG may constrain the conformational plasticity of the peptide, preventing insertion of the peptide into the inner side of the membrane and thus promoting fibrillation on the membrane surface. The results suggest that the charge properties of the membrane, the composition of the liposomes, and the rigidity of lipid packing are critical in determining peptide adsorption on the membrane surface and the efficiency of the membrane in catalyzing peptide oligomeric nucleation and amyloid formation., 2023, Includes bibliography., Degree granted: Dissertation (PhD)--Florida Atlantic University, 2023., Collection: FAU Electronic Theses and Dissertations Collection

Broad adoption of magnetic soft robotics is hampered by the sophisticated field paradigms for their manipulation and the complexities in controlling multiple devices. Furthermore, high‐throughput fabrication of such devices across spatial scales remains challenging. Here, advances in fiber‐based actuators and magnetic elastomer composites are leveraged to create 3D magnetic soft robots controlled by unidirectional fields. Thermally drawn elastomeric fibers are instrumented with a magnetic composite synthesized to withstand strains exceeding 600%. A combination of strain and magnetization engineering in these fibers enables programming of 3D robots capable of crawling or walking in magnetic fields orthogonal to the plane of motion. Magnetic robots act as cargo carriers, and multiple robots can be controlled simultaneously and in opposing directions using a single stationary electromagnet. The scalable approach to fabrication and control of magnetic soft robots invites their future applications in constrained environments where complex fields cannot be readily deployed.

Transition state search is key in chemistry for elucidating reaction mechanisms and exploring reaction networks. The search for accurate 3D transition state structures, however, requires numerous computationally intensive quantum chemistry calculations due to the complexity of potential energy surfaces. Here we developed an object-aware SE(3) equivariant diffusion model that satisfies all physical symmetries and constraints for generating sets of structures—reactant, transition state and product—in an elementary reaction. Provided reactant and product, this model generates a transition state structure in seconds instead of hours, which is typically required when performing quantum-chemistry-based optimizations. The generated transition state structures achieve a median of 0.08 Å root mean square deviation compared to the true transition state. With a confidence scoring model for uncertainty quantification, we approach an accuracy required for reaction barrier estimation (2.6 kcal mol–1) by only performing quantum chemistry-based optimizations on 14% of the most challenging reactions. We envision usefulness for our approach in constructing large reaction networks with unknown mechanisms.

Intense surface eruptions are observed along the curved surface of a confined cylindrical film of hydrogel subject to laser-induced converging-diverging shock loading. Detailed numerical simulations are used to identify the dominant mechanisms causing mechanical instability. The mechanisms that produce surface instability are found to be fundamentally different from both acoustic parametric instability and shock-driven Richtmyer-Meshkov instability. The time scale of observed and simulated eruption formation is much larger than that of a single shock reflection, in stark contrast to previously studied shock-driven instabilities. Moreover, surface undulations are only found along external, as opposed to internal, soft solid boundaries. Specifically, classic bubble surface instability mechanisms do not occur in our experiments and here we comment only on the new surface undulations found along the outer boundary of solid hydrogel cylinders. Our findings indicate a new class of impulsively excited surface instability that is driven by cycles of internal shock reflections.

Maximizing surface-to-body ratio demands ever smaller metallic palladium (Pd) nanoparticles for catalytic applications. The quest for miniaturization is now reaching the single-atom limit. However, if the supported Pd is below a critical size, the Pd hybridization with the supporting material can detrimentally reduce the labile electrons that facilitate the catalytic reactions. Thus, the smallest attainable size, i.e., single-atom Pd, may not offer the best efficiency. Here, it is demonstrated that Pd with at least six atomic layers (or thickness of approximate to 1 nm) on the silicate sheets, synthesized via the partial exfoliation of a layered silicate, exhibits a metallic-like electronic property, yielding an excellent catalytic activity (e.g., turnover frequency) for dehydrogenating formic acid higher than both isotropic Pd nanoparticles and single-atom Pd., Scientific and Technological Research Council of Turkey (TÜBİTAK); European Union (EU); Horizon 2020; Marie Sklodowska Curie; Co-Funded Brain Circulation Program Framework; This work was supported by the JSPS KAKENHI (grant Nos. 21F20040 and 21H02034). Moreover, the authors gratefully acknowledge the funding of this project by computing time provided by the Paderborn Center for Parallel Computing (PC2).

Various glass-ceramics are widely used or considered for use as components of microelectronic materials due to their promising properties. In this study, borosilicate glass was prepared using the powder metallurgical route and then mixed with different amounts of Al2O3 and ZrO2 filler materials. Glass-ceramics are produced by high-energy ball milling and conventional sintering process under Ar or air. In this study, the effects of different filler materials and different atmospheres on the microstructural, thermal and dielectric properties were investigated. The data showed that ZrO2 filler material led to better results than Al2O3 under identical working conditions and similar composite structures. ZrO2 filler material significantly enhanced the densification process of glass-ceramics (100% relative density) and led to a thermal conductivity of 2.904 W/K.m, a dielectric constant of 3.97 (at 5 MHz) and a dielectric loss of 0.0340 (at 5 MHz) for the glass with 30 wt.% ZrO2 sample. This paper suggests that prepared borosilicate glass-ceramics have strong sinterability, high thermal conductivity, and low dielectric constants, making them promising candidates for microelectronic devices., This research was funded by Akcoat Advanced Chemical Coating Materials Co. grant number A-0020011.

In the present work, unilamellar [SrTa(2)O7](2-) perovskite nanosheets with variable lateral dimensions were synthesized via a high-yield, three-step liquid exfoliation route from layered Bi2SrTa2O9. The photocatalytic activity of the parent and exfoliated layered perovskites was evaluated for the photocatalytic dye degradation of Rhodamine B under UV light (254 nm) and reduction of water to H-2 under the full solar spectrum. A comparative study of the photocatalytic behavior of unilamellar [SrTa(2)O7](2-) perovskite nanosheets and parent layered structure showed a significant improvement in both hydrogen evolution (98.20 vs 3 mu mol g(-1)) and Rhodamine B degradation time (180 vs 30 min), with the restacked nanosheets. The exfoliation of layered perovskites not only increases their specific surface area, providing more active sites, but also reduces the recombination probability of electrons and holes due to their unilamellar structure and reduced charge transport pathways. The synthesis and preparation of strong acid solids such as [SrTa(2)O7](2-) perovskite nanosheets can be a promising approach for effective adsorption of pollutants with cationic nature and more efficient electron transfer between the dye and catalyst. Finally, the photocatalytic characteristics of the restacked unilamellar [SrTa(2)O7](2-) nanosheets remained unchanged after three successive cycles of recycling-reusing., Scientific and Technological Research Council of Turkey (TÜBİTAK); TÜBİTAK- MSRT Joint Call; Tabriz University

The security of future energy, hydrogen, is subject to designing high-performance, stable, and low-cost electrocatalysts for hydrogen and oxygen evolution reactions (HERs and OERs), for the realization of efficient overall water splitting. Two-dimensional (2D) metal-organic frameworks (MOFs) introduce a large family of materials with versatile chemical and structural features for a variety of applications, such as supercapacitors, gas storage, and water splitting. Herein, a series of nanocomposites based on NCM/Ni-BDC@NF (N?Ni, C?Co, M:F?Fe, C?Cu, and Z?Zn, BDC: benzene dicarboxylic acid, NF: nickel foam) were directly developed on NF using a facile yet scalable solvothermal method. After coupling, the electronic structure of metallic atoms was well-modulated. Based on the XPS results, for the NCF/Ni-BDC, cationic atoms shifted to higher oxidation states, favorable for the OER. Conversely, for the NCZ/Ni-BDC and NCC/Ni-BDC nanocomposites, cationic atoms shifted to lower oxidation states, advantageous for the HER. The as-prepared NCF/Ni-BDC demonstrated prominent OER performance, requiring only 1.35 and 1.68 V versus a reversible hydrogen electrode to afford 10 and 50 mA cm-2 current densities, respectively. On the cathodic side, NCZ/Ni-BDC exhibited the best HER activity with an overpotential of 170 and 350 mV to generate 10 and 50 mA cm-2, respectively, under 1.0 M KOH medium. In a two-electrode alkaline electrolyzer, the assembled NCZ/Ni-BDC (cathode) ? NCF/Ni-BDC (anode) couple demanded a cell voltage of only 1.58 V to produce 10 mA cm-2. The stability of NCF/Ni-BDC toward OER was also exemplary, experiencing a continuous operation at 10, 20, and 50 mA cm-2 for nearly 45 h. Surprisingly, the overpotential after OER stability at 50 mA cm-2 dropped drastically from 450 to 200 mV. Finally, the faradaic efficiencies for the overall water splitting revealed the respective values of 100 and 85% for the H2 and O2 production at a constant current density of 20 mA cm-2, U.A. would like to acknowledge the financial support provided by the Turkish Academy of Sciences?Outstanding Young Scientist Award Program. Likewise, the authors thank Dr. Barış Yağcı and Dr. Amir Motallebzadeh, at the Koç University Surface Science and Technology Center for their help with characterizations. We also would like to thank Zafer Eroğlu for his generous help with HAADF-STEM. The authors would like to express their sincere gratitude to researchers at the Koç University Tüpraş Energy Center (KUTEM), especially Saeede Tafazoli for her help with the GC measurements. Finally, we are grateful to Dr. Süleyman Tekmen from the Bayburt University Central Research Laboratory (BUMER) for the HR-TEM measurements.

Two ionic liquids (ILs) having the same cation with different anions offering opposite hydrophilic/hydrophobic characters, 1-n-butyl-1-methylpyrrolidinium dicyanamide ([BMPyr][DCA]) and 1-n-butyl-1-methylpyrrolidinium hexafluorophosphate ([BMPyr][PF6]), were impregnated onto two different reduced graphene aerogels (rGAs) prepared by the thermal treatment of GAs at 300 and 500 degrees C to investigate the consequences of the changes in the hydrophilic character of ILs and the reduction temperature of the GAs on the corresponding gas sorption and separation performance of the IL/rGAs. The structural analyses of nanoporous rGAs and IL/rGAs pointed to a change in the quantity of oxygenated functional groups upon thermal treatment and a change in the direct interactions between IL molecules and the host rGA surface upon IL deposition. Single-component CO2 and CH4 sorption measurements were performed for each rGA and IL/rGA composite, and both ideal and mixture CO2/CH4 selectivities were calculated. The samples prepared by reducing the GA at 300 and 500 degrees C yielded ideal CO2/ CH4 selectivities of 3.6 and 18 at 1 mbar and 25 degrees C, respectively. Among IL/rGA composites, the one prepared at 300 degrees C displayed a remarkable CO2/CH4 separation performance when combined with the hydrophobic [BMPyr][PF6], offering an ideal selectivity of 450.9 at 1 mbar and 25 degrees C, whereas the composite prepared with rGA500 yielded a substantially high CO2/CH4 selectivity of 173.5 after the incorporation of the hydrophilic [BMPyr][DCA] at 1 mbar and 25 degrees C. The ideal CO2/CH4 selectivities of [BMPyr][PF6]/ rGA300 and [BMPyr][DCA]/rGA500 surpassed most of the previously reported selectivities of carbon-based materials in the literature. These results demonstrate the broad potential of IL/rGAs in sorption-based gas separations owing to the highly tunable nature of both the structure of IL and the surface characteristics of rGA., Scientific and Technological Research Council of Turkey (TÜBİTAK)

It is well-known that salinity is an important adverse environmental factor (abiotic stresses) that limits plant growth, development, and productivity all over the world. Herein, we report for the first time the use of graphene oxide (GO) as a promising material against the salinity stress using melon (Cucumis melo L.) seeds as the model crop. GO as a priming material possesses various advantages such as being highly water-soluble, nontoxic, producible on a large scale from graphite, and low-cost over the existing materials. In this study, we identified the effect of different GO doses (0, 0.25, 0.50, 0.75, and 1.0 mg/mL) on seed germination of melon (Cucumis melo L. cvs. 'Hasanbey', 'Kirkagac-589', and 'Kirkagac-637') seeds under the salinity stress. The effect of GO as a priming material showed variance depending on the GO dose, melon cultivars, and level of salinity stress. It was determined that the germination percentage and the length of the radicle were higher in GO primed seeds compared to the control in all the melon cultivars tested. All cultivars did not germinate in the control at the highest salinity stress (26.20 dS m-1). The germination percentage of the GO-treated seeds changed in the range of 12.25% (0.50 mg mL-1 GO) -16.63% (0.25 mg mL-1 GO) at the highest salinity stress in 'Kirkagac-589'. Radicle lengths of 'Hasanbey', 'Kirkagac-589', and 'Kirkagac-637' varied from 0.47, 0.57, 1.67 cm to 7.80, 9.47, and 8.80 cm, respectively, as the salinity stress elevated to 15 g L-1 (0 to 26.20 dS m-1). We believe that this study will pave the way for the application of GO as a priming material for both melon and different crops for eliminating problems of salinity stress., We would like to thank the Turkish Academy of Sciences (TUBA) for the financial support.

We present accurate ab initio calculations on several properties of a gas-phase system of interest in the interstellar medium (ISM), where the title molecular anion has been often surmised but not yet confirmed by observations. The CH-3 sigma+ constitutes the smallest term in the series of longer anionic polyynes which have been observed in the ISM (e.g., C4H-and several others). Hence, its dynamical behavior in collision with He atoms, one of the most abundant atoms in that environment, can provide quantitative indicators on the changes which can occur in the rotational state population of the title anion when driven by this collision dynamics. We therefore report an accurate evaluation of the full potential energy surface (PES) which acts between the molecular anion in its ground vibrational state and the He atom. The relevant inelastic scattering cross sections and the corresponding inelastic rate coefficients are then computed within a quantum treatment of the collisions. We find that the fairly small values of the final inelastic rate coefficients indicate state-changing processes by collisions to be inefficient paths for modifying the rotational state populations of this anion and therefore to aid its possible observation from direct radiative emission in the microwave region., Open Accessis fundedby the AustrianScienceFund (FWF).