Electron Acceptor Research Articles

A theoretical investigation for improving the performance of non-fullerene organic solar cells through side-chain engineering of BTR non-fused-ring electron acceptors

In the current quantum chemical study, indacenodithiophene donor core-based the end-capped alterations of the reference chromophore BTR drafted eight A2-A1-D-A1-A2 type small non-fullerene acceptors. All the computational simulations were executed under MPW1PW91/6-31G (d, p) level of DFT. The UV-Vis absorption, open circuit voltage, electron affinity, ionization potential, the density of states, reorganization energy, orbital analysis, and non-covalent interactions were studied and compared with BTR. Several molecules of our modeled series BT1-BT8 have shown distinctive features that are better than those of the BTR. The open circuit voltage (VOC) of BT5 has a favorable impact, allowing it to replace BTR in the field of organic solar cells. The charge carrier motilities for proposed molecules generated extraordinary findings when matched to the reference one (BTR). Further charge transmission was confirmed by creating the complex with a PM6 donor molecule. The remarkable dipole moment contributes to the formation of non-covalent bond interactions with chloroform, resulting in superior charge mobility. Based on these findings, it can be said that every tailored molecule has the potential to surpass chromophore molecule (BTR) in OSCs. So, all tailored molecules may enhance the efficiency of photovoltaic cells due to the involvement of potent terminal electron-capturing acceptor2 moieties. Considering these obtained results, these newly presented molecules can be regarded for developing efficient solar devices in the future.

Photoselectively modulating main products by changing the wavelength of visible light over D-π-A-D conjugated polymers

The diversity of catalytic products determines the difficulty of selective product modulation, which usually relies on adjusting the catalyst and reaction conditions to obtain different main products selectively. Herein, we synthesized D-π-A-D conjugated organic polymers (TH-COP) using cyclotriphosphonitrile, alkyne, 2H-benzimidazole, and sulfur units as electron donors, π bridges, electron acceptors, and electron donors, respectively. TH-COP exhibited excellent photoinduced carrier separation and redox ability under different visible light wavelengths, and the main products of its CO2 reduction are CH4 (1000.0 μmol g−1) and CO (837.0 μmol g−1) under 400–420 nm and 420–560 nm, respectively. In addition, TH-COP could completely convert phenylmethyl sulfide to methyl phenyl sulfone at 400–420 nm and diphenyl disulfide at 480–485 nm in yields up to 95 %. This study presents a novel strategy for the targeted fabrication of various main products using conjugated polymers by simply changing the wavelength range of visible light.

Simulation of microbial transport and petroleum hydrocarbon compound biodegradation in a fracture–matrix coupled system

In-situ bioremediation technology is considered an ideal and environment-friendly approach for the largescale treatment of petroleum-contaminated soil. Most earlier studies on bioremediation have focused on the biostimulation techniques, which can enhance the biodegradation capabilities of indigenous bacteria, rather than on bioaugmentation involving the introduction of exogenous microorganisms. Additionally, contaminated soil sites typically contain both natural and artificial fractures. These fractures serve as preferential transport pathways, complicating the transport of bacteria and related solutes. This study proposes a mathematical model to simulate the transport of exogenous bacteria and electron acceptors during the degradation of petroleum hydrocarbon pollutants in a fractured aquifer system. The model incorporates the processes such as microbial convection, diffusion, adsorption, chemotaxis, growth, death, and microbial metabolic reactions. Simulation results demonstrate that considering microbial transport significantly affects the prediction of contaminant degradation, particularly with regard to the transport of electron acceptors. The growth rate of bacteria has an evident effect on the efficiency of contaminant remediation, and microbial chemotaxis can significantly enhance the degradation efficiency. The proposed mathematical model serves as a valuable tool for assessing the effectiveness of bioaugmentation strategies and can aid in the design and optimization of remediation efforts for contaminated and fractured aquifers.

Multifunctional lipid droplet probes for observing the polarity change of ferroptosis, inflammation, fatty liver and evaluating the efficacy of drugs

BackgroundLipid droplets (LDs) polarity is intricately linked to diverse biological processes and diseases. The visualization of LDs-polarity is of vital importance but challenging due to the lack of high-specificity, high-sensitivity and large-Stokes shift probes for real-time tracking LDs-polarity in biological systems. ResultsFour D-π-A based fluorescent probes (TPA-TCF1-TPA-TCF4) have been developed by combining tricyanofuran (an electron acceptor, A) and triphenylamine (an electron donor, D) derivatives with different terminal groups. Among them, TPA-TCF1 and TPA-TCF4 exhibit excellent polar sensitivity, large Stokes shift (≥182 nm in H2O), and efficient LDs targeting ability. In particular, TPA-TCF4 is capable of monitoring the change of LDs-polarity during ferroptosis, inflammation, apoptosis of cancer cell, and fatty liver. SignificanceAll these features render TPA-TCF4 a versatile tool for pharmacodynamic evaluation of anti-cancer drugs, in-depth understanding of the biological effect of LDs on ferroptosis, and medical diagnosis of LDs-polarity related diseases.

Multifunctional effect of copper in bimetallic Cu-M/Al2O3 catalysts (M = Fe, Co, and Ni) for NH3 decomposition

Ammonia is a promising hydrogen carrier, which can enhance energy transport efficiency when bulk NH3 is transported in a gas carrier vessel. At the end of the NH3 transport, the NH3 gas should be converted to H2 and N2 using NH3 decomposition catalyst, which has outstanding catalytic performance and low cost. The M/Al2O3 and Cu-M/Al2O3 catalysts (M = Fe, Co, and Ni) were test and characterized regarding catalytic NH3 decomposition because we expected the Cu addition could differently change the electronic structure and the desorption behaviors of active metal species. As our expectation, the added Cu modified the catalytic performance and characteristics, but these changes were different, depending on the kind of active metal species (Fe, Co, and Ni). The catalytic activity was improved for Fe/Al2O3 but worsened for Co/Al2O3 and Ni/Al2O3. In addition, the added Cu element acted as an electron donor in Cu-Fe/Al2O3 but as an electron acceptor in Cu-Co/Al2O3 and Cu-Ni/Al2O3 and influenced the desorption behaviors of the generated H and N atoms, particularly in the Cu-Fe/Al2O3, the added Cu alleviated the desorption behaviors of H and N atoms but suppress them in the Cu-Co/Al2O3 and Cu-Ni/Al2O3, which affected the catalytic performance of NH3 decomposition.

Elucidating distinct roles of chemical reduction and autotrophic denitrification driven by three iron-based materials in nitrate removal from low carbon-to-nitrogen ratio wastewater

Effective nitrate removal is a key challenge when treating low carbon-to-nitrogen ratio wastewater. How to select an effective inorganic electron donor to improve the autotrophic denitrification of nitrate nitrogen has become an area of intense research. In this study, the nitrate removal mechanism of three iron-based materials in the presence and absence of microorganisms was investigated with Fe2+/Fe0 as an electron donor and nitrate as an electron acceptor, and the relationship between the iron materials and denitrifying microorganisms was explored. The results indicated that the nitrogen removal efficiency of each iron-based material coupled sludge systems was higher than that of iron-based material. Furthermore, compared with the sponge iron coupled sludge system (60.6% - 70.4%) and magnetite coupled sludge (56.1% - 65.3%), the pyrite coupled sludge system had the highest removal efficiency of TN, and the removal efficiency increased from 62.5% to 82.1% with time. The test results of scanning electron microscope, X-ray photoelectron spectroscopy and X-ray diffraction indicated that iron-based materials promoted the attachment of microorganisms and the chemical reduction of nitrate in three iron-based material coupled sludge systems. Furthermore, the pyrite coupled sludge system had the highest nitrite reductase activity and can induce microorganisms to secrete more extracellular polymer substances. Combined with high-throughput sequencing and PICRUSt2 functional predictive analysis software, the total relative abundance of the dominant bacterial in pyrite coupled sludge system was the highest (72.06%) compared with the other iron-based material systems, and the abundance of Blastocatellaceae was relatively high. Overall, these results suggest that the pyrite coupled sludge system was more conducive to long-term stable nitrate removal.

Effects of graphene doping and gas adsorption on the peak positions of graphene plasmon resonance and adsorbate infrared absorption

The peak positions of graphene plasmon resonance can be controlled to overlap with those of the infrared absorption spectra of gas molecules, allowing highly sensitive detection and identification by graphene nanoribbons. In this study, we investigate the adsorption of gas molecules, including SO2, SO3, H2S, and NH3, on graphene and characterize its effects on the relative positions of the two peaks using density functional theory and the finite difference time domain method. It is demonstrated that the binding energies are stronger, and the amounts of charge transfer are greater in the case of SO2 and SO3 adsorbed on n-doped graphene than in other cases. Electron acceptance by SO2 and SO3 adsorbates on n-doped graphene redshifts the graphene plasmon resonance peaks and their stretching and wagging infrared absorption peaks. However, the former is significantly further redshifted, leading to narrower peak-position-matching ribbon widths in n-doped graphene than in p-doped graphene. The amounts of charge transfer are relatively small regardless of the doping type in the case of NH3 and H2S, mitigating the doping-type dependence compared to SO2 and SO3. The wagging peaks of NH3 on n-doped graphene are shown to be further blueshifted than on p-doped graphene, rendering their peak-position-matching ribbon widths further closer to each other. These results suggest that the effects of doping and adsorption on the two types of peaks should be considered to optimize the performance of graphene plasmon-based gas sensing and identification.

Charge separation control in organic photosensitizers for photocatalytic water splitting without sacrificial electron donors

Photocatalytic hydrogen evolution reaction (photoHER) is one of the most promising approaches towards production of “green” hydrogen. Currently, the state-of-the-art photoHER systems require the use of sacrificial electron donors (SED), because of inefficient charge separation in photosensitizers and thermodynamically challenging water oxidation by the same catalyst. Here, we present a molecular design approach for all-organic photosensitizers with effective intramolecular charge separation, microsecond lifetime of excited states, controllable direction of electron transfer, and ability to oxidize water for recovery of the photocatalytic system to its initial state. Such photosensitizers comprise weakly conjugated strong electron donor and acceptor what enables charge transfer during the light absorption. The excitation energy is stored in long-living triplet states, whose lifetime can be monitored by the thermally activated delayed fluorescence. Additionally, application of heavy-atom effect helps not only to increase the population of triplet state but also to increase its stability and lifetime. When such photosensitizers are attached to the platinized TiO2, efficient photoHER catalysts are obtained which produce H2 under irradiation with sunlight. In the presence of SED, the highest turnover number after 24 h (TON24h) of such systems exceed 3500, whilst in pure water without any SED, TON24h reaches 2000. Our best system performs photocatalytic SED-free water-splitting for 48 h keeping 100 % of its activity and constant turnover frequency of 26 h−1. The described here investigations reveal that water splitting can be performed by a simple three component system “photosensitizer|TiO2|Pt” under specific control of 1) the charge separation and its direction, 2) intersystem crossing rate and triplet state lifetime, and 3) favorable water oxidation thermodynamics within a photosensitizer together with 4) appropriate alignment of energy levels to the catalyst.

Asymmetric acceptor-donor-acceptor type covalent organic frameworks with dual O2 reduction moieties for boosting H2O2 photosynthesis

The study of hydrogen peroxide production by O2 reduction reaction using covalent organic framework (COF) photocatalysts has attracted extensive attention in recent years. However, there are still great challenges in accurately controlling their structures to achieve rapid carrier separation and efficient O2 reduction. Based on this, we constructed the A1-D-A2 COF photocatalytic material (TT-DTDA-COF) with asymmetric dual acceptor sites by connecting thieno [3,2-b] thiophene, benzene, and triazine as the basic units through imine bonds. Under the synergistic effect of thieno [3,2-b] thiophene and triazine electron acceptors, the separation and transfer efficiency of TT-DTDA-COF photogenerated carriers was significantly enhanced. At the same time, according to the in-situ infrared and DFT calculation results, it was found that these two acceptor units served as O2 reduction sites, which realized the multi-site adsorption reduction of O2, and effectively enhanced the efficiency of photocatalytic O2 reduction to H2O2. The experimental results showed that the H2O2 generation rate of TT-DTDA-COF with A1-D-A2 dual receptor structure was 1302 μmol·g−1·h−1 under visible light irradiation, which was 3.4 times higher than that of TB-DTDA-COF with single receptor D-A structure and higher than that of most of the materials reported so far. This study provides a new idea for accurately designing COF-based photocatalysts to achieve efficient O2 reduction to produce H2O2.

Hydrogen peroxide production in pure water on a pyrrole-containing hydrothermal carbon photocatalyst

Herein, a pyrrole-containing hydrothermal carbon (N-SHTC) was developed by a simple one-step hydrothermal carbonization approach using starch and nitric acid as starting reactants. The introduction of nitric acid promoted the dehydration and carbonization of starch and led to the synthesis of N-SHTC at lower hydrothermal temperature, and also resulted in the incorporation of N into the furan structure to form pyrrole units. The charge transfer efficiency of N-SHTC was significantly improved due to the introduced pyrrole units as potential electron acceptor. With no scavengers or O2 bubbling, N-SHTC exhibited a H2O2 production rate of 1132 μmol g-1 h-1 in pure water under visible light. Notably, the H2O2 photoproduction performance of N-SHTC was further enhanced in the presence of metal salt ions due to the strengthened electron-withdrawing property of pyrrole units caused by the metal salt ions. These merits enabled N-SHTC the potentially practical applications in photocatalytic production of H2O2.

Molecular insight into the allocation of organic carbon to heterotrophic bacteria: Carbon metabolism and the involvement in nitrogen and phosphorus removal

Carbon metabolism and nutrient removal are crucial for biological wastewater treatment. This study focuses on analyzing carbon allocation and utilization by heterotrophic bacteria in response to increasing COD concentration in the influent. The study also assesses the effect of denitrification and biological phosphorus removal, particularly in combination with anaerobic ammonia oxidation (anammox). The experiment was conducted in a SBR operating under anaerobic/anoxic/oxic conditions. As COD concentration in the influent increased from 100 to 275 mg/L, intracellular COD accounted for 95.72 % of the COD removed. By regulating the NO3− concentration in the anoxic stage from 10 to 30 mg/L, the nitrite accumulation rate reached 69.46 %, which could serve as an electron acceptor for anammox. Most genes related to the tricarboxylic acid (TCA) cycle declined, while the genes involved in the glyoxylate cycle, gluconeogenesis, PHA synthesis increased. This suggests that glycogen accumulation and carbon storage, rather than direct carbon oxidation, was the dominant pathway for carbon metabolism. However, the genes responsible for the reduction of NO2−-N (nirK) and NO (nosB) decreased, contributing to NO2− accumulation. The study also employed metagenomic analysis to reveal microbial interactions. The enrichment of specific bacterial species, including Dechloromonas sp. (D2.bin.10), Ca. Competibacteraceae bacterium (D9.bin.8), Ca. Desulfobacillus denitrificans (D6.bin.17), and Ignavibacteriae bacterium (D3.bin.9), played a collaborative role in facilitating nutrient removal and promoting the combination with anammox.

G-C3N4-Catalyzed photochemical synthesis of trifluoromethylated gem-difluoroalkenes from α-trifluoromethyl styrenes and CF3SO2Na

Trifluoromethyl-substituted gem-difluoroalkenes were synthesized via the reaction of α-trifluoromethyl styrenes with trifluoromethyl radical derived from sodium trifluoromethylsulfinate under the visible light induced graphitic carbon nitride-mediated heterogeneous photocatalysis. The disclosed process is based on the sequential radical/ionic transformations of α-trifluoromethyl alkenes. The developed approach exploits the dual role of g-C3N4 as a photocatalyst. g-C3N4 acts as an electron acceptor for the generation of CF3 radicals and participates in the reduction of intermediate carbon-centered radical with β-elimination of fluoride anion and formation of the target products.

Origin of two-dimensional hole gas at the hydrogen-terminated diamond surfaces: Negative interface valence-induced upward band bending

The surface transfer doping model has been extensively adopted as a mechanism to account for the generation of hole accumulation layers below hydrogen-terminated diamond (H-diamond) surfaces. To achieve effective surface transfer doping, surface electron acceptor materials with high electron affinity (EA) are required to produce a high density of two-dimensional hole gas (2DHG) on the H-diamond subsurface. We have established ingenious theoretical models to demonstrate that even if these solid materials do not have a high EA value, they remain capable of absorbing electrons from the H-diamond surface by forming a negatively charged interface to act as a surface electron acceptor in the surface transfer doping model. Our calculations, particularly for the local density of states, provide compelling evidence that the effect of an interface with negative charges induces an upward band bending on the H-diamond side. Furthermore, the valence band maximum of the diamond atoms at the interface crosses the Fermi level, giving rise to strong surface transfer p-type doping. These results give a strong theoretical interpretation of the origin of 2DHG on H-diamond surfaces. The proposed guidelines contribute to further improvements in the performance of 2DHG H-diamond field effect transistors.

Efficient photocatalytic remediation of persistent organic pollutants using magnetically recoverable spinel manganese ferrite nanoparticles supported on activated carbon

Magnetically recoverable spinel manganese ferrite (MFO) nanoparticles (NPs) supported on activated carbon (AC) (MFC), a promising photocatalyst, were prepared by simple and cost-effective gel combustion. AC supports prevented particle agglomeration and functioned as electron acceptors to promote charge separation on MFO. MFC samples demonstrated significant surface area, paramagnetic characteristics, and visible-light absorption bandgap of 2.02 eV. Pentachlorophenol (PCP) photodegradation using MFC showed degradation efficiency of at least 90% after 150 minutes at pH 6.0 with the catalyst dose and PCP concentration of no more than 10 mg.L−1 and 9.0 ppm, respectively. MFC exhibited durability and recyclability with approximately 4% decrease in degradation efficiency after five reuses while maintaining its material structure. The crucial roles of photo-generated electrons and hydroxyl radicals related to dechlorination and hydroxylation during PCP photodegradation were also highlighted in active species investigations with appropriate scavengers. Subsequently, a plausible PCP photodegradation mechanism with intermediates was proposed.

Methane mitigation via the nitrite-DAMO process induced by nitrate dosing in sewers

Nitrate or nitrite-dependent anaerobic methane oxidation (n-DAMO) is a microbial process that links carbon and nitrogen cycles as a methane sink in many natural environments. This study demonstrates, for the first time, that the nitrite-dependent anaerobic methane oxidation (nitrite-DAMO) process can be stimulated in sewer systems under continuous nitrate dosing for sulfide control. In a laboratory sewer system, continuous nitrate dosing not only achieved complete sulfide removal, but also significantly decreased dissolved methane concentration by ∼50 %. Independent batch tests confirmed the coupling of methane oxidation with nitrate and nitrite reduction, revealing similar methane oxidation rates of 3.68 ± 0.5 mg CH4 L−1 h−1 (with nitrate as electron acceptor) and 3.57 ± 0.4 mg CH4 L−1 h−1 (with nitrite as electron acceptor). Comprehensive microbial analysis unveiled the presence of a subgroup of the NC10 phylum, namely Candidatus Methylomirabilis (n-DAMO bacteria that couples nitrite reduction with methane oxidation), growing in sewer biofilms and surface sediments with relative abundances of 1.9 % and 1.6 %, respectively. In contrast, n-DAMO archaea that couple methane oxidation solely to nitrate reduction were not detected. Together these results indicated the successful enrichment of n-DAMO bacteria in sewerage systems, contributing to approx. 64 % of nitrite reduction and around 50 % of dissolved methane removal through the nitrite-DAMO process, as estimated by mass balance analysis. The occurrence of the nitrite-DAMO process in sewer systems opens a new path to sewer methane emissions.

Copper-Based Two-Dimensional Metal-Organic Frameworks for Fenton-like Photocatalytic Degradation of Methylene Blue under UV and Sunlight Irradiation.

To efficiently degrade organic pollutants, photocatalysts must be effective under both ultraviolet (UV) radiation and sunlight. We synthesized a series of new metal-organic frameworks by using mild hydrothermal conditions. These frameworks incorporate three distinct bipyridyl ligands: pyrazine (pyr), 4,4'-bipyridine (bpy), and 1,2-bis(4-pyridyl)ethane (bpe). The resulting compounds are denoted as [Cu(pyz)(H2O)2MF6], [Cu(bpy)2(H2O)2]·MF6, and [Cu(bpe)2(H2O)2]·MF6·H2O [M = Zr (1, 3, and 5) and Hf (2, 4, and 6)]. All six compounds exhibited a two-dimensional crystal structure comprising infinitely nonintersecting linear chains. Compound 3 achieved 100% degradation of methylene blue (MB) after 8 min under UV irradiation and 100 min under natural sunlight in the presence of H2O2 as the electron acceptor. For compound 5, 100% MB degradation was achieved after 120 min under sunlight and 10 min under UV light. Moreover, reactive radical tests revealed that the dominant species involved in photocatalytic degradation are hydroxyl (•OH), superoxide radicals (•O2-), and photogenerated holes (h+). The photodegradation process followed pseudo-first-order kinetics, with photodegradation rate constants of 0.362 min-1 (0.039 min-1) for 3 and 0.316 min-1 (0.033 min-1) for 5 under UV (sunlight) irradiation. The developed photocatalysts with excellent activity and good recyclability are promising green catalysts for degrading organic pollutants during environmental decontamination.

Synthesis, Characterization and Photovoltaic Properties of Polyplatinaynes with Side Chain Functionalization by Different Electron-Accepting Group

AbstractFour new solution-processable platinum-containing polyynes functionalized with triphenylamine backbone and different acceptor fragment in the side chain were synthesized and characterized by spectroscopic, thermal and optical methods. The main- and side-chains show different absorption features in the solar spectrum, resulting in broad absorption coverage of the whole visible region. By changing the acceptor group in the side chain, the photophysical properties including energy levels, absorption wavelength and bandgap of the polymers were finely tuned. As the strength of electron acceptor is increased, the power conversion efficiency (PCE) of organic polymer solar cells fabricated with these polymers as electron donor and (6,6)-phenyl-C61-butyric acid methyl ester (PCBM) as electron acceptor was increased. PCE of 1.35% can be obtained from solar cell based on the polyplatinayne with the dicyanovinyl side group under illumination of an AM 1.5 solar cell simulator in a 1:4 (polymer:PCBM) blend ratio. Graphical Abstract

Rapid degradation of high-concentration antibiotic via heterogeneous photocatalysis coupling Fenton-like oxidation with MIL-53(Fe) under visible light irradiation

The photocatalytic technology based on Metal-Organic Frameworks (MOFs) has shown promising applications in the field of antibiotic pollution control. However, it still faces challenges in efficiently removing high-concentration antibiotic wastewater. A typical Fe-containing MOF, MIL-53(Fe), was successfully synthesized and demonstrated efficient photocatalytic activity under visible light irradiation for high-concentrations of tetracycline hydrochloride (TCH). However, the bare MIL-53(Fe) exhibited unsatisfactory photocatalytic performance. To overcome the low degradation efficiency resulting from the rapid recombination of light-induced electron-hole pairs, H2O2 was introduced as an external electron acceptor to establish a synergistic Fenton-like system to couple with the photocatalysis process. The results showed that in the MIL-53(Fe)/H2O2/Vis system, 99% of 1 g/L TCH was degraded within 80 min, while the degradation efficiency of the MIL-53(Fe)/Vis process was only 4.89% under identical conditions. The degradation mechanism of the coupling system was performed by radical scavenging experiments and Electron Spin Resonance characterization. The results indicated that ·OH was the dominant radical in the coupled reaction, and ·O2- and h+ also played a role in this system. The significant improvement in TCH degradation efficiency during the coupling process was attributed to the following three factors: (1) In the coupling reaction process, photo-generated electrons can stimulate H2O2 to form ·OH radicals, inhibiting the recombination of photo-generated electrons and holes, improving the efficiency of the photocatalytic reaction. (2) FeIII in MIL-53(Fe) can be excited by photo-generated electrons and converted to FeII, which then stimulates H2O2 to form ·OH radicals. (3) FeIII in MIL-53(Fe) can convert with FeII, stimulate H2O2 to form ·OH radicals, and participate in the degradation reaction. In addition, the reusability and stability of the MIL-53(Fe) photocatalyst in the coupled system, as well as the impact of operational parameters, were systematically studied. This work demonstrates a feasible strategy for environmental remediation by enhancing the efficiency of MIL-53(Fe) in photocatalytic Fenton-like systems, thereby providing a viable approach for the treatment of high-concentration antibiotic wastewater.

Infection-associated gene regulation of L-tartrate metabolism in Salmonella enterica serovar Typhimurium.

Bacterial pathogens must adapt their gene expression profiles to cope with diverse environments encountered during infection. This coordinated process is carried out by the integration of cues that the pathogen senses to fine-tune gene expression in a spatiotemporal manner. Many studies have elucidated the regulatory mechanisms of how Salmonella sense metabolites in the gut to activate or repress its virulence program; however, our understanding of how Salmonella coordinates its gene expression to maximize the utilization of carbon and energy sources found in transitional nutrient niches is not well understood. In this study, we discovered how Salmonella integrates two infection-relevant cues, substrate availability and exogenous electron acceptors, to control L-tartrate metabolism. From our experiments, we propose a model for how L-tartrate metabolism is regulated in response to different metabolic cues in addition to characterizing two previously unknown transcriptional regulators. This study expands our understanding of how microbes combine metabolic cues to enhance fitness during infection.

Machine learning assisted designing of non-fullerene electron acceptors: A quest for lower exciton binding energy

The designing of acceptors materials for the organic solar cells is a hot topic. The normal experimental methods are tedious and expensive for large screening. Machine learning guided exploration is more suitable solution. Bagging regression, random forest regression, gradient boosting regression, and linear regression are trained to predict exciton binding energy. Breaking Retrosynthetically Interesting Chemical Substructures (BRICS) methodology has utilized for designing of new non-fullerene acceptors (NFAs). The predicted values were used to select the designed NFAs. On the selected NFAs, clustering and chemical similarity analyses are also performed. Chemical fingerprints are used for this purpose, and the synthetic accessibility score of the new NFAs is also investigated.30 NFAs have selected with low exciton binding energy values. This approach will allow for the rapid screening of NFAs for organic solar cells. Our proposed framework stands out as a valuable tool for strategically selecting the most effective NFAs for organic solar cells and offers a streamlined approach for material discovery.