Organic Compounds Research Articles

The formation of exciplex and triplet-triplet transfer in organic room temperature phosphorescent guest-host materials.

Organic materials typically do not phosphoresce at room temperature because both intersystem crossing (ISC) and phosphorescence back to the electronic ground state are slow, compared to the nonradiative decay processes. A group of organic guest-host molecules breaks this rule. Their phosphorescence at room temperature can last seconds with a quantum efficiency of over 10%. This extraordinary phenomenon is investigated with comprehensive static and transient spectroscopic techniques. Time-resolved vibrational and fluorescence spectral results suggest that a singlet guest-host exciplex quickly forms after excitation. The formation of exciplex reduces the singlet-triplet energy gap and helps facilitate charge separation that can further diffuse into the host matrix. The heavy atoms (P or As) of the host molecule can also help enhance the spin orbital coupling of the guest molecule. Both boost the rate of ISC. After the singlet exciplex transforms into the triplet exciplex through the ISC process, UV-visible transient absorption spectroscopic measurements support that the triplet exciplex quickly transforms into the guest molecule triplet state that is at a lower energy level, thereby reducing the reverse ISC-induced triplet population loss. Finally, the long-lasting separated charges that diffused into the host matrix can diffuse back to the guest hole to form new triplets, and the dilution effect of the host molecules can effectively reduce the triplet quenching. All these factors contribute to the dramatic enhancement of phosphorescence at room temperature.

Specific and high-affinity adsorption of volatile organic compounds on titanium dioxide surface.

The interaction between metal oxides and volatile organic compounds (VOCs) from the ambient atmosphere plays an important role in environmental and catalytic applications. Previous scanning probe microscopy and x-ray spectroscopy studies revealed surprisingly that the TiO2 [rutile (110)] surface selectively adsorbed atmospheric carboxylic acids, which typically exist in only parts-per-billion concentrations. In this work, we used in situ sum-frequency vibrational spectroscopy to study the interaction between rutile (110) and typical VOC molecules, including formic acid, acetic acid, and formaldehyde. Spectra from all three adsorbed molecules on rutile (110) were similar to the rutile surface spectrum in the ambient atmosphere, showing a broad resonance near 2950cm-1 that can be attributed to the bridging bidentate adsorption of corresponding compounds. In contrast, on a fused silica surface, a molecular monodentate adsorption configuration was observed for all the molecules, with aliphatic carbons appearing to be the dominant adventitious species.

A Comprehensive Review of Advanced Treatment Technologies for the Enhanced Reuse of Produced Water

Produced water (PW) is considered to be the largest source of industrial wastewater associated with oil and gas extraction operations for industrial production. It is a mixture of organic and inorganic compounds that has high complexity in terms of various characteristics. Globally, the volume of PW is increasing along with the expansion of gas and oil fields, leading to major impacts on the environment. Existing treatment technologies involve partially treating the PW through removing the suspended solids, heavy metals, without removing organic components and re-injecting the water underground using water disposal injection wells. The treatment process consists of a primary treatment unit to remove the particles, followed a secondary biological or chemical processing treatment, while the final treatment stage involves the use of a tertiary treatment unit to improve the water quality and remove the remainder of the undesired components. Moreover, while PW is considered one of the available options to be utilized as a water source, no alternate advanced treatment options on a commercial scale are available at present due to the limitations of existing PW treatment technologies, associated with their maintainability, sustainability, cost, and level of quality improvement. As such, research focused on finding an optimal treatment approach to improve the overall process continues to be conducted, with the aim of reusing the water instead of injecting it underground. This literature review discusses the latest advanced technologies for PW treatment aimed at reusing the full stream capacity of PW and eliminating the need for wastewater disposal via injection. It is concluded that researchers should focus on hybrid treatment technologies in order to remove the pollutants from PW, effectively allowing for its reuse.

Concrete Actions for Improving Indoor Air Quality in Korea: Advancing Public Health for Vulnerable Populations

In modern society, individuals spend an increasing amount of time indoors, emphasizing the importance of understanding the health impacts of indoor environments. This study focused on measuring indoor air quality to identify vulnerable populations and observe the effects of residential environment improvements on air quality. Targeting low-income families and elderly households, known for their heightened vulnerability to environmental health risks, the study involved direct visits to 2328 low-income households across 16 cities and provinces in South Korea from 2021 to 2022. Indoor air quality parameters, including PM2.5, PM10, total volatile organic compounds (TVOC), formaldehyde (HCHO), and airborne mold, were measured. Among these households, 300 with critically compromised living conditions received support for wallpaper and paneling replacement. Comparative measurements before and after the renovations revealed that single-person households had higher levels of PM2.5 and TVOC compared with households with four or more members. Additionally, households with elevated concentrations of airborne mold also exhibited higher levels of PM2.5 and PM10. Importantly, households that received environmental improvements showed a significant reduction in airborne mold concentration by approximately 50% or more. This study underscores the importance of indoor environmental health and provides valuable evidence supporting policies focused on health promotion and residential welfare improvements for vulnerable populations. The research is distinguished by its comprehensive nature, involving direct measurements from nearly 2000 households nationwide, rather than relying solely on secondary data.

Antibacterial photocatalytic films for effective degradation of organic compounds

Antibacterial photocatalytic films for effective degradation of organic compounds

Biotechnology of groundwater purification for water supply systems, using Gallionella and Lepthothrix ferrobacteria

Aim. The aim of the study was to consider the possibility of using the consortia of chemolithoautotrophic ferrobacteria from Gallionella genus and heterotrophic bacteria from Lepthothrix genus for the biological method of groundwater purification. Methods. The photocolorimetric method to determine the concentrations of ammonium and iron ions, the titrimetric method to determine the hydrocarbon and total alkalinity, the method of determining the permanganate oxidizability using the Kubel method, the potentiometric method to determine the values of рН and Еh, the electronic microscopy using the X-ray spectral analysis of matrix structures of bio-minerals, microbiological and statistical methods. Results. The main technological parameters of the water deironing process were defined as follows: the filtration velocity of the bioreactor – 7–11 m/h, and of the filters – 3.5–5 m/h; the filter-cycle duration – 48 h. It was found that the application of the two-stage technology of biological deironing in the bioreactor and filters provided for the possible removal of Fe2+ compounds up to 5.0 mg/cdm, ammonium nitrogen — up to 1.5 mg/cdm, soluble organic substances by PO – up to 6.0 mg O2/cdm. It was determined that the optimal parameters for the process of biological purification of neutral groundwaters, containing increased concentrations of Fe2+ cations were as follows: рН 7.0–7.2; hydrocarbon alkalinity 2.5–2.2 mmol/cdm; content of soluble oxygen – 1.5–2.0 mg/cdm. The ability of concentrated (Dos 200 mg/cdm) matrix structures of Gallionella and Lepthothrix ferrobacteria to remove Cr6+ ions from natural groundwaters was determined. The study found no considerable differences in the efficiency of applying disinfectants, produced using polyhexamethylene guanidine chloride (PHMGchl) or polyhexamethylene biguanidine chloride (PHMBchl). In concentrations of 0.25–0.5 %, they effectively disinfect pathogenic microorganisms, including Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The same was found true for the bacteria, most common in the systems of technical reverse water supply, the systems of water circulation, plant watering, and fire tanks, including Aeromonas hydrophila, Aeromonas salmonicida, Pseudomonas sp., E. coli, Flavobacterium columnare, Micrococcus lysodeikticus. Conclusions. This was the first study on the possibility of applying the biotechnology of groundwater purification from excessive amounts of iron in conditions of uneven hydraulic burden, notable for the water supply systems of rural areas and most agricultural enterprises in the north-western and northern regions of Ukraine. The specificities and perspectives of PHMGchl application in the systems of water preparation were studied. It was found that from the standpoint of safety and efficiency, the use of the water deironing processes involving iron bacteria was reasonable in the systems of water consumption and technical water supply, and the disinfection of water using PHMG was possible only in the second case, due to some toxicity of the preparation. The optimal parameters for the process of biological purification of neutral groundwaters, containing increased concentrations of Fe2+ cations were determined.

Excited State Dynamics of Geometrical Evolution of α-Substituted Dibenzoylmethanatoboron Difluoride Complex with Aggregation-Induced Emission Property.

Organic molecules with an aggregation-induced emission (AIE) property have been attracting much attention from the viewpoint of application to solid state emissive materials. For the AIE mechanism, quantum mechanical studies proposed the restriction of the intramolecular motion (RIM) model with the contribution of the conical intersection (CI) and deduced the importance of the restricted access to a conical intersection (RACI) in the potential energy surface (PES). Although these theoretical studies have contributed to the elucidation of AIE phenomena, direct detection of the reaction dynamics is indispensable to clarify the actual PES and the deactivation mechanism. Along this line, we investigated excited state dynamics of the AIE molecule with dibenzoylmethanatoboron difluoride complexes using time-resolved absorption spectroscopies in both visible and infrared (IR) regions. While the reference system of 1,3-bis(4-methoxyphenyl)methanatoboron difluoride (2aBF2) showed strong emission in solution, the methyl-substituted derivative at the α-position of the dioxaborine ring (2amBF2) led to the very weak fluorescence in solution but strong emission in the solid state. Time-resolved visible absorption measurements revealed a peak shift and broadening of the stimulated emission in the solution of 2amBF2, owing to the rapid change of the molecular geometry. With the temporal evolution of time-resolved IR absorption signals and density functional theory (DFT) calculation of these systems, it was deduced that 2amBF2 has two stable geometries, namely, planar and bending, in the S1 state and the bending geometry in the S1 state led to rapid conversion to the S0 state. These results support the RACI model in the aggregated states, leading to the AIE properties.

Transformação sustentável

The objective of the research was to apply composting techniques and social technology to treat food waste in a low -income condominium in southern Brazil, with the joint participation of university researchers and residents. The purpose was not only to reduce the environmental impact caused by waste, but also generate organic compounds of environmental and agronomic value. The project started with an observational visit to the condominium to identify appropriate spaces for the execution of the work. Then the researchers promoted the project through posters and direct conversations with the residents. After this interaction, training workshops were held for participating residents, totaling 40 families and 122 people. The workshops addressed topics such as the impacts of food waste, segregation at source, the composting process and social technology. Educational materials were distributed to assist in the learning process, and visual resources, such as workshops and educational videos, were used. Finally, the composting process was implemented. Social technology played a significant role throughout the process. During workshops and interactions with residents, participants became active learning agents, sharing traditional knowledge and integrating them with scientific knowledge. Educational materials have represented an important tool for social technology, providing information in an accessible and motivational way. The active participation of researchers and residents was also a positive aspect of this investigation, as it strengthened the condominium community, created social bonds and promoted awareness of environmental responsibility.

Immunization of male BALB/c and C57BL/6 mice similar modulates chemical signals detected in both chromatographic and behavioral tests

The odor plays a key role in communication between animals and the choice of a mate. The odor of urine of males becomes less attractive to mature females after infection or activation of the immune system. The development of the immune response in the early stages is related with the production of both pro-inflammatory and anti-inflammatory cytokines. To investigate the chemical basis of the observed differences and examine the influence of female interactions with the odor of antigen-treated males, we immunized males of inbred BALB/c (Th1) and C57BL/6 (Th2) mice with hemocyanin (KLH). For females of both tested strains, the attraction of the odor of male urine collected 3 days after immunization was lower compared with the odor of control males. Herewith, BALB/c females sniffed the urine of immunized males less frequently, and C57BL/6 females demonstrated a shorter duration of grooming in olfactory tests with urine of immunized males. The altered response of females to the odor of male urine collected on day 3 after KLH injection matched with antigen-induced modulation of relative levels of volatile organic compounds (VOCs) detected in urine samples by gas chromatography and mass spectroscopy (GC-MS). In males of both strains, after KLH injection, an increase in the content of nonanal, benzothiazole, as well as 2-sec-butyl-4,5-dihydrothiazole, and [1,4,5]-oxadithiepane was shown. At the same time, no compounds were found, the content of which changes in different directions in the urine of males after immunization, depending on the strain of the animal.

Microbial community evolution in a lab-scale reactor operated to obtain biomass for biochemical methane potential assays.

Biochemical methane potential (BMP) test is an important tool to evaluate the methane production biodegradability and toxicity of different wastes or wastewaters. This is a key parameter for assessing design and feasibility issues in the full-scale implementation of anaerobic digestion processes. A standardized and storable inoculum is the key to obtain reproducible results. In Uruguay, a local enterprise dedicated to design and install anaerobic digesters operated a lab-scale bioreactor as a source of biomass for BMP tests, using a protocol previously described. This reactor was controlled and fed with a mixture of varied organic compounds (lipids, cellulolytic wastes, proteins). Biomass was reintroduced into the reactor after BMP assays to maintain a constant volume and biomass concentration. The aim of this work was to evaluate how the microbial community evolved during this operation and the effect of storing biomass in the refrigerator. The composition of the microbial communities was analyzed by 16S rRNA amplicon sequencing using primers for Bacteria and Archaea. The methanogenic activity was determined, and the methanogens were quantified by mcrA qPCR. One sample was stored for a 5-month period in the refrigerator (4°C); the activity and the microbial community composition were analyzed before and after storage. Results showed that applying the reported methodology, a reliable methanogenic sludge with an acceptable SMA was obtained even though the reactor suffered biomass alterations along the evaluated period. Refrigerating the acclimatized biomass for 5months did not affect its activity nor its microbial composition according to the 16S rRNA gene sequence analysis, even though changes in the mcrA abundance were observed. KEY POINTS: • The applied methodology was successful to obtain biomass suitable to perform BMP assays. • The microbial community was resilient to external biomass addition. • Biomass storage at 4°C for 5months did not alter the methanogenic activity.

Satellite‐Based Identification of Large Anthropogenic NMVOC Emission Sources

AbstractNonmethane volatile organic compounds (NMVOCs) emitted in excess from anthropogenic sources significantly contribute to the formation of harmful pollutants, thereby degrading air quality. While satellite measurements have become valuable tools for tracking anthropogenic emitters, they have primarily targeted inorganic species and methane (). This study demonstrates the potential of infrared atmospheric sounding interferometers (IASI) to detect anthropogenic NMVOC point sources on a global scale. Using an advanced oversampling technique, we enhance the spatial resolution of IASI measurements to identify emitters of three major NMVOCs: methanol (OH), acetylene (), and propylene (). These point sources are primarily associated with chemical and petrochemical facilities, coal‐burning activities, metallurgy, pharmaceutical manufacturing sites, and megacities. We also highlight the value of combining IASI measurements of NMVOCs with those of the inorganic species, such as sulfur dioxide () and ammonia (), to aid in the identification of anthropogenic point sources.

Integrated multi-approaches reveal unique metabolic mechanisms of Vestimentifera to adapt to deep sea.

Vestimentiferan tubeworms are deep-sea colonizers, in which chemoautotrophic symbiosis was first observed. These animals are gutless and depend on endosymbiotic bacteria for organic compound synthesis and nutrition supply. Taxonomically, vestimentiferans belong to Siboglinidae and Annelida. Compared with other siboglinids, vestimentiferans are distinguished by high tolerance of the prevailing hydrogen sulfide in hydrothermal vents, rapid growth in local habitats, and a physical structure consisting of a thick chitinous tube. The metabolic mechanisms contributing to these features remain elusive. Comparative genomics revealed that unlike other annelids, vestimentiferans possessed trehaloneogenesis and lacked gluconeogenesis. Transcriptome and metabolome analyses detected the expression of trehalose-6-phosphate synthase/phosphatase (TPSP), the key enzyme of trehaloneogenesis, and trehalose production in vestimentiferan tissues. In addition to trehaloneogenesis, glycogen biosynthesis evidenced by packed glycogen granules was also found in vestimentiferan symbionts, but not in other Siboglinidae symbionts. Data mining and analyses of invertebrate TPSP revealed that the TPSP in Vestimentifera, as well as Cnidaria, Rotifera, Urochordata, and Cephalochordata, likely originated from Arthropoda, possibly as a result of transposon-mediated inter-phyla gene transfer. This study indicates a critical role of bacterial glycogen biosynthesis in the highly efficient symbiont - vestimentiferan cooperation. This study provides a new perspective for understanding the environmental adaptation strategies of vestimentiferans and adds new insights into the mechanism of metabolic evolution in Metazoa. Video Abstract.

Hydrogen-Bonded Organic Framework and Metal-Organic Framework Assembly of Waterwheel PgC-Noria Molecule: Regulating Microstructure Enables Iodine Transfer.

Hydrogen-bonded organic frameworks (HOFs) are a type of crystalline porous materials self-assembled from organic or metal-organic building blocks via intermolecular hydrogen bonding, which have received increasing attention due to their reversible and flexible hydrogen bonding properties. Currently, it remains a challenge to construct HOFs based on complex or porous organic cages as molecular building blocks. Herein, a 3D HOF (PgC-HOF) featuring honeycomb-shaped channels is crafted utilizing a sizable waterwheel-like PgC-noria organic molecule cage. The pivotal role of intermolecular multipoint hydrogen bonding interactions in upholding structural integrity and stability is underscored by the possession of 36 phenolic hydroxyl groups in PgC-HOF. Interestingly, the introduction of calcium ions into the reaction system results in the formation of the metal-organic framework (PgC-MOF), with the channel dimensions increasing from 6.8 to 9.1Å. Furthermore, I2 sorption/release experiments are conducted on PgC-HOF and PgC-MOF, achieving an increase in the optimal adsorption amount from 1.45 to 2.19gg-1 and a transition from an irreversible adsorbent to a reversible adsorbent.

A Comprehensive Study of the Degradation of Veterinary Antibiotics by Non-Thermal Plasma: Computational, Experimental, and Biotoxicity Assessments

Water quality is threatened by numerous pollutants, among which antibiotics are of great concern due to their widespread use and unaltered excretion, leading to water contamination and fostering antibiotic resistance. To comprehensively address sustainable water remediation, herein, the susceptibility to non-thermal plasma degradation of two veterinary antibiotics (Oxytetracycline (OTC) and Lincomycin (LNC)) are compared in an integral approach, including computational analyses, plasma irradiation assays, and a byproduct toxicity assessment. The computational assessment was performed by evaluating the ionization potential (IP) obtained from Density Functional Theory calculations and determining the antibiotics’ susceptible sites for radical attack. Plasma irradiation achieved nearly complete degradation (~100%) of both compounds with the initial concentration of 1 mg L−1, while 60% degradation was observed when the starting concentration was 10 mg L−1. The mineralization rates were 21% and 31% for OTC and LNC, respectively. The degradation profiles followed similar trends, as expected from their comparable IP values. After treatment, the solution exhibited lower biotoxicity compared to the original antibiotics. Therefore, this work represents a step forward in addressing one of the key environmental challenges of our time and encourages further extending the analysis towards the remediation of water polluted with many other organic compounds.

Reduction of hexavalent chromium by compost-derived dissolved organic matter.

Compost-derived dissolved organic matter (DOMC) is a heterogeneous assemblage of different redox-active organic molecules. We hypothesize that DOMC can interact with Cr(VI) and reduce it to Cr(III), thereby influencing the dynamics of Cr(VI) in soil and aquatic environments. Here, DOMC, along with soil humic substances isolated from red soil and black soil, were fractionated into humic acid fractions (i.e., HAC, HAB, and HAR) and fulvic acid fractions (i.e., FAC, FAB, and FAR), respectively. The reduction and interaction between Cr(VI) and the six organic matter fractions were investigated. The results showed that the total Cr(VI) reduction capacity (TRC) of the six organic matter fractions was 26.77-49.34 μM Cr(VI) per mg OM. The TRC of HA fractions was 35.54-49.34 μM Cr(VI) per mg OM, which exceeded that of FA fractions (26.77-31.29 μM Cr(VI) per mg OM). DOMC had a HA/FA ratio of 0.64, which was higher than that of black soil humic substance (0.59) and red soil humic substance (0.20). The sum of the TRC of DOMC was 35.57 μM Cr(VI) per mg OM, which was larger than that of black soil humic substance (32.87 μM Cr(VI) per mg OM) and red soil humic substance (33.01 μM Cr(VI) per mg OM). The TRC was positively correlated with TOC, TN, phenol C, alkyl C, and aromatic C contents and negatively correlated with E2/E3, O-alkyl C, and carboxyl C contents. The reduction of Cr(VI) at pH 6 was negligible, whereas 32-67% Cr(VI) was reduced at pH 2. The Cr(VI) reduction capacities (RC2, RC2, and RC6) at pH 2-6 were positively correlated (R2 > 0.71) with phenol C. Spectral analysis showed that there was no obvious complexation between Cr(VI) and the six organic matter fractions at pH 6, and thus the reduction of Cr(VI) was negligible, but solution pH could affect the accessibility of organic molecules to Cr(VI) and thus influence Cr(VI) reduction.

Carbon-silicon-switch effect in enantioselective construction of silicon-stereogenic center from silacyclohexadienones.

Carbon-silicon-switch strategy, replacing one specific carbon atom in organic molecules with a silicon, has garnered significant interest for developing new functional molecules. However, the influence of a reaction regarding its selectivity and reactivity by carbon-silicon-switch strategy has far less been investigated. Here we discover an unusual carbon-silicon-switch effect in the enantioselective construction of silicon-stereogenic center. It is found that there has been a significant change in the desymmetrization reaction of silacyclohexadienones using asymmetric conjugate addition or oxidative Heck reaction with aryl/alkyl nucleophiles when compared with their carbon analogues cyclohexadienones. Specifically, the carbon-silicon-switch leads to a reversal in enantioselectivity with arylzinc as the nucleophile by the same chiral catalyst, and results in totally different reactivity with arylboronic acid as the nucleophile. Control experiments and density functional theory (DFT) calculations have shown that the unusual carbon-silicon-switch effect comes from the unique stereoelectronic feature of silicon.

Metallaphotocatalytic triple couplings for modular synthesis of elaborate N-trifluoroalkyl anilines.

The integration of trifluoromethyl groups and three-dimensional quaternary carbon moieties into organic molecules has emerged as a prominent strategy in medicinal chemistry to augment drug efficacy. Although trifluoromethyl (hetero)aromatic amines and derivatives are prevalent frameworks in pharmaceuticals, the development of trifluoromethyl-embedded, intricately structured alkyl amine scaffolds for medicinal research remains a significant challenge. Herein, we present a metallaphotoredox multicomponent amination strategy employing 3,3,3-trifluoropropene, nitroarenes, tertiary alkylamines, and carboxylic acids. This synthetic pathway offers notable advantages, including the accessibility and cost-effectiveness of starting materials, high levels of chemo- and regioselectivity, and modularity. Furthermore, this approach enables the synthesis of a broad spectrum of aniline compounds featuring both trifluoromethyl group and distal quaternary carbon motifs along the aliphatic chains. The accelerated access to such elaborate N-trifluoroalkyl anilines likely involves three sequential radical-mediated coupling events, providing insightful implications for the retrosynthesis of potential compounds in organic synthesis and drug discovery.

Metagenomics analysis of bacterial community structure from wood- and soil-feeding termites: metabolic pathways and functional structures toward the degradation of lignocellulose and recalcitrant compounds

Some essential information on gut bacterial profiles and their unique contributions to food digestion in wood-feeding termites (WFT) and soil-feeding termites (SFT) is still inadequate. The feeding type of termites is hypothesized to influence their gut bacterial composition and its functionality in degrading lignocellulose or other organic chemicals. This could potentially provide alternative approaches for the degradation of some recalcitrant environmental chemicals. Therefore, metagenomic analysis can be employed to examine the composition and functional profiles of gut bacterial symbionts in WFT and SFT. Based on the metagenomic analysis of the 16S rRNA gene sequences of gut bacterial symbionts in the WFT, Microcerotermes sp., and the SFT, Pericapritermes nitobei, the findings revealed a total of 26 major bacterial phyla, with 18 phyla commonly represented in both termites, albeit in varying abundances. Spirochaetes dominated the bacterial symbionts in Microcerotermes sp. at 55%, followed by Fibrobacters, while Firmicutes dominated the gut bacteria symbionts in P. nitobei at 95%, with Actinobacteria coming in second at 2%. Furthermore, the Shannon and phylogenetic tree diversity indices, as well as the observed operational taxonomic units and Chao 1 richness indices, were all found to be higher in the WFT than in the SFT deduced from the alpha diversity analysis. Based on the principal coordinate analysis, exhibited a significant distance dissimilarity between the gut bacterial symbionts. The results showed that the gut bacterial composition differed significantly between the WFT and SFT. Furthermore, Tax4Fun analysis evaluated bacterial functions, revealing the predominance of carbohydrate metabolism, followed by amino acid metabolism and energy metabolism in both Microcerotermes sp. and P. nitobei termites. The results implicated that bacterial symbionts inhabiting the guts of both termites were actively involved in the degradation of lignocellulose and other recalcitrant compounds.

Plant organic nitrogen nutrition: costs, benefits, and carbon use efficiency.

Differences in soil mobility and assimilation costs between organic and inorganic nitrogen (N) compounds would hypothetically induce plant phenotypic plasticity to optimize acquisition of, and performance on, the different N forms. Here we evaluated this hypothesis experimentally and theoretically. We grew Arabidopsis in split-root setups combined with stable isotope labelling to study uptake and distribution of carbon (C) and N from l-glutamine (l-gln) and NO3 - and assessed the effect of the N source on biomass partitioning and carbon use efficiency (CUE). Analyses of stable isotopes showed that 40-48% of C acquired from l-gln resided in plants, contributing 7-8% to total C of both shoots and roots. Plants grown on l-gln exhibited increased root mass fraction and root hair length and a significantly lower N uptake rate per unit root biomass but displayed significantly enhanced CUE. Our data suggests that organic N nutrition is linked to a particular phenotype with extensive growth of roots and root hairs that optimizes for uptake of less mobile N forms. Increased CUE and lower N uptake per unit root growth may be key facets linked to the organic N phenotype.

Boron nitride nanotubes as carriers of genistein for multitherapeutic cancer treatment: A DFT study of electronic and solubility properties

Increasing cancer mortality statistics demand more accurate and efficient treatments. Nanostructures have proved to be promising choices in this regard. Nanotubes with large surface areas can play multiple roles from drug carriers in targeted drug delivery to beam absorbers in the photothermal method. While carbon nanotubes (CNTs) show cytotoxicity, Boron Nitride Nanotubes (BNNTs) offer wide bandgap and biocompatibility. In this study, we investigate the electronic and solvation properties of (5,5), (6,6), and (7,7) BNNTs computationally by the density functional theory. For multimodal therapy, we considered Iron (Fe) doping in the BNNT, which can be helpful in hyperthermia due to the magnetic moment of Fe. Our results show that doping has improved the band positions. Furthermore, we implemented an organic anticancer molecule, genistein, a metastasis inhibitor. All potent configurations connecting genistein with BNNT covalently demonstrated enhanced water solubility as compared to pristine and Fe-doped BNNTs. The results suggest that the (7,7) C3 complex is the most stable structure and the best drug carrier.