Energy Transfer Studies Research Articles

Estimation of Land Surface Heat Fluxes Based on Landsat 7 ETM+ Data and Field Measurements over the Northern Tibetan Plateau

Land surface heat fluxes consist of the net radiation flux, soil heat flux, sensible heat flux, and latent heat flux. The estimation of these fluxes is essential to the study of energy transfer in land–atmosphere systems. In this paper, Landsat 7 ETM+ SLC-on data were applied to estimate the land surface heat fluxes on the northern Tibetan Plateau using the SEBS (surface energy balance system) model, in combination with the calculation of field measurements at CAMP/Tibet (Coordinated Enhanced Observing Period (CEOP) Asia–Australia Monsoon Project on the Tibetan Plateau) automatic weather stations based on the combinatory method (CM) for comparison. The root mean square errors between the satellite estimations and the CM calculations for the net radiation flux, soil heat flux, sensible heat flux, and latent heat flux were 49.2 W/m2, 46.3 W/m2, 68.2 W/m2, and 54.9 W/m2, respectively. The results reveal that land surface heat fluxes all present significant seasonal variability. Apart from the sensible heat flux, the satellite-estimated net radiation flux, soil heat flux, and latent heat flux exhibited a trend of summer > spring > autumn > winter. In summer, spring, autumn, and winter, respectively, the median values of the net radiation flux (631.8 W/m2, 583.0 W/m2, 404.4 W/m2, 314.3 W/m2), soil heat flux (40.9 W/m2, 37.9 W/m2, 26.1 W/m2, 20.5 W/m2), sensible heat flux (252.7 W/m2, 219.5 W/m2, 221.4 W/m2, 204.8 W/m2), and latent heat flux (320.1 W/m2, 298.3 W/m2, 142.3 W/m2, 75.5 W/m2) exhibited distinct seasonal diversity. From November to April, the in situ sensible heat flux is higher than the latent heat flux; the opposite is true between June and September, leaving May and October as transitional months. For water bodies, alpine meadows and other main underlying surface types, sensible and latent heat flux generally present contrasting and complementary spatial distributions. Due to the 15–60 m resolution of the Landsat 7 ETM+ data, the distribution of land surface heat fluxes can be used as an indicator of complex underlying surface types over the northern Tibetan Plateau.

Polymerization-Induced Polymersome Fusion.

The dynamic interactions of membranes, particularly their fusion and fission, are critical for the transmission of chemical information between cells. Fusion is primarily driven by membrane tension built up through membrane deformation. For artificial polymersomes, fusion is commonly induced via the external application of a force field. Herein, fusion-promoted development of anisotropic tubular polymersomes (tubesomes) was achieved in the absence of an external force by exploiting the unique features of aqueous ring-opening metathesis polymerization-induced self-assembly (ROMPISA). The out-of-equilibrium tubesome morphology was found to arise spontaneously during polymerization, and the composition of each tubesome sample (purity and length distribution) could be manipulated simply by targeting different core-block degrees of polymerization (DPs). The evolution of tubesomes was shown to occur via fusion of “monomeric” spherical polymersomes, evidenced most notably by a step-growth-like relationship between the fraction of tubular to spherical nano-objects and the average number of fused particles per tubesome (analogous to monomer conversion and DP, respectively). Fusion was also confirmed by Förster resonance energy transfer (FRET) studies to show membrane blending and confocal microscopy imaging to show mixing of the polymersome lumens. We term this unique phenomenon polymerization-induced polymersome fusion, which operates via the buildup of membrane tension exerted by the growing polymer chains. Given the growing body of evidence demonstrating the importance of nanoparticle shape on biological activity, our methodology provides a facile route to reproducibly obtain samples containing mixtures of spherical and tubular polymersomes, or pure samples of tubesomes, of programmed length. Moreover, the capability to mix the interior aqueous compartments of polymersomes during polymerization-induced fusion also presents opportunities for its application in catalysis, small molecule trafficking, and drug delivery.

Understanding the Behavior of Monocationic and Dicationic Room-Temperature Ionic Liquids through Resonance Energy-Transfer Studies.

The present work has been undertaken with an objective to understand the differences in the local structural organization of imidazolium-based monocationic ionic liquids (MILs) and dicationic ionic liquids (DILs) through resonance energy-transfer (RET) studies. In this study, a neat IL is used as a donor and a charged species rhodamine 6G (R6G) is used as an acceptor unit because of the fact that they satisfy the spectroscopic criteria that are needed for an RET event to take place. Additionally, R6G, being a charged species, is expected to facilitate the electrostatic interactions with the ILs which are also charged. Specifically, two imidazolium-based germinal DILs and their monocationic counterparts are used for the present investigations. Additionally, the studies are carried out in some selected MILs where the lengths of the alkyl side chains are kept unchanged for MILs and DILs. Interestingly, the present data reveal that the RET interaction is more favorable for DILs than for MILs, even though the DILs are relatively bulkier than their monocationic counterparts. More interestingly, the RET interaction is also found to be more favorable for DILs than for MILs, where the length of the alkyl group is kept fixed for MILs and DILs. The result of the present study delineates that the alkyl chain length on the cation is not the sole factor contributing to the RET outcomes for DILs and MILs but the local structure of DILs also contributes significantly to the same. The current investigation clearly indicates that DILs have a more compact local structure than that of MILs. Essentially, the current study highlights that a cost-effective, noninvasive technique such as RET is quite effective in capturing the differences in the nanostructural organization of MILs and DILs.

Effects of vanadium(IV) compounds on plasma membrane lipids lead to G protein-coupled receptor signal transduction

Luteinizing hormone receptors (LHR), expressed at physiological numbers <30,000 receptors per cell, translocate to and signal within membrane rafts following binding of human chorionic gonadotropin (hCG). Similarly LHR signal in cells when treated with bis(maltolato)oxovanadium(IV) (BMOV), bis(ethylmaltolato)oxovanadium(IV) (BEOV) or VOSO4, which decrease membrane lipid packing. Overexpressed LHR (>85,000 receptors per cell) are found in larger clusters in polarized homo-transfer fluorescence resonance energy transfer (homo-FRET) studies that were not affected by either hCG or vanadium compounds. Intracellular cyclic adenylate monophosphate (cAMP) levels indicate that only clustered LHR are active and produce the intracellular second messenger, cAMP. When LHR are over-expressed, cell signaling is unaffected by binding of hCG or vanadium compounds. To confirm the existence of intact complex, the EPR spectra of vanadium compounds in cell media were obtained using 1 mM BMOV, BEOV or VOSO4. These data were used to determine intact complex in a 10 μM solution and verified by speciation calculations. Effects of BMOV and BEOV samples were about two-fold greater than those of aqueous vanadium(IV) making it likely that intact vanadium complex are responsible for effects of LHR function. This represents a new mechanism for activation of a G protein-coupled receptor; perturbations in the lipid bilayer by vanadium compounds lead to aggregation and accumulation of physiological numbers of LHR in membrane raft domains where they initiate signal transduction and production of cAMP, a second messenger involved in signaling.

Photoluminescence properties of Sm3+ -doped LiPbB5O9 phosphor for reddish-orange emitting light applications

A new system, LiPbB5O9 phosphor with varied concentrations of Sm3+ ions was synthesized by the high temperature solid state reaction method. The X-ray diffraction profiles were obtained for all phosphors. The functional groups present in these samples were analysed by the FTIR spectrum. SEM images were used to examine the morphology of the as prepared phosphors. Thermal properties were studied by the TG-DTA analysis. The luminescent properties of LiPbB5O9:Sm3+ phosphor with varied concentrations of Sm3+ ions at λem = 601 nm and λex = 401 nm were studied. And also concentration quenching and energy transfer studies in these phosphors were reported. Energy transfer parameters (Q) and correlated colour temperatures (CCT) of LiPbB5O9:Sm3+ phosphors were calculated and reported. The lifetimes of 4G5/2 level in LiPbB5O9:Sm3+ phosphors were measured using decay curves. The colour co-ordinates, which are used to characterise the colour of the phosphors were also calculated. These results suggest that LiPbB5O9:Sm3+ phosphors could be promising candidates for orange-red light emission applications.

Energy transfer studies between mixed Au-Pd cyanide nanosystems and Tb+3 doped in different alkali halides

Heterometallic d10-d8 nano systems of dicyanoaurate(I) and tetracyanopalladate(II) with Tb+3 doped in different alkali halide hosts (NaCl, NaBr, and KBr) have been studied. This is the first time three such ions have been synthesized and studied in alkali halide hosts. Raman measurements were performed to elucidate the nature of the nanocluster structures. Vibrational measurements reveal that Tb+3 substitution of the alkali halide does not occur without regard to the dispersion and configuration of Au(CN)2−/Pd(CN)4−2 codopants. Low temperature luminescence measurements show broad emission bands associated with a combination of Au(CN)2− and Pd(CN)4−2 MLCT. Terbium f-f emission bands are observed with intensities on the order of KBr > NaBr > NaCl, counter to the higher concentration of Tb+3 in NaCl. Our results indicate that f-f emissions arise from resonance energy transfer from a mixed Au/Pd nanocluster, which preferentially form in larger alkali halide hosts. We support our findings using DFT calculations.

Теоретическое исследование безызлучательного переноса энергии от эксиплекса к перовскитам

Теоретическое исследование безызлучательного переноса энергии от эксиплекса к перовскитам

Double Rabi Splitting in a Strongly Coupled System of Core-Shell Au@Ag Nanorods and J-Aggregates of Multiple Fluorophores.

The interaction of several components in the strong coupling regime yielding multiple Rabi splittings opens up remarkable possibilities for studies of multimode hybridization and energy transfer, which is of considerable interest in both fundamental and applied science. Here we demonstrate that three different components, such as core-shell Au@Ag nanorods and J-aggregates of two different dyes, can be integrated into a single hybrid structure, which leads to strong collective exciton-plasmon coupling and double-mode Rabi splitting totaling 338 meV. We demonstrate strong coupling in these multicomponent plexitonic nanostructures by means of magnetic circular dichroism spectroscopy and demonstrate strong magneto-optical activity for the three hybridized states resulting from this coupling. The J-aggregates of two different nonmagnetic dyes interact with metal nanoparticles effectively, achieving magnetic properties due to the hybridization of electronic excitations in the three-component system.

Color tunability and energy transfer studies of a new Eu3+ doped langbeinite-type phosphate phosphor for lighting applications

Phosphate compounds have been widely studied in solid luminescence due to their variable structure types and excellent performance. In this work, we reported a new langbeinite-type phosphate, K2DyHf(PO4)3, in which the octahedral sites are mixed occupied by Dy3+ and Hf4+ ions. For further confirm the proportion of Dy/Hf, we carried out scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) analysis. Meanwhile, in order to investigate the effect of Eu3+ doping on the luminous properties, a series of Eu3+ doped solid solutions K2Dy1-xEuxHf(PO4)3 (x = 0, 0.01, 0.02, 0.03, 0.04, 0.05, 0.1, 0.2, 0.4, 0.6, 0.8, 1.0) were prepared and investigated by powder X-ray diffraction, IR, UV–Vis. The photoluminescence spectra demonstrated that energy transfer between Dy3+ and Eu3+ happens. The results suggest that the emiting light can be tuned from whitish, yellowish to orangish in K2Dy1-xEuxHf(PO4)3 phosphors by modulating x values.

A Novel Conjugate of Bis[((4-bromophenyl)amino)quinazoline], a EGFR-TK Ligand, with a Fluorescent Ru(II)-Bipyridine Complex Exhibits Specific Subcellular Localization in Mitochondria.

The epidermal growth factor receptor (EGFR) is a key target in anticancer research, whose aberrant function in malignancies has been linked to severe irregularities in critical cellular processes, including cell cycle progression, proliferation, differentiation, and survival. EGFR mutant variants, either transmembrane or translocated to the mitochondria and/or the nucleus, often exhibit resistance to EGFR inhibitors. The ability to noninvasively image and quantify EGFR provides novel approaches in the detection, monitoring, and treatment of EGFR-related malignancies. The current study aimed to deliver a new theranostic agent that combines fluorescence imaging properties with EGFR inhibition. This was achieved via conjugation of an in-house-developed ((4-bromophenyl)amino)quinazoline inhibitor of mutant EGFR-TK, selected from a focused aminoquinazoline library, with a [Ru(bipyridine)3]2+ fluorophore. A triethyleneglycol-derived diamino linker featuring (+)-ionizable sites was employed to link the two functional moieties, affording two unprecedented Ru conjugates with 1:1 and 2:1 stoichiometry of aminoquinazoline to the Ru complex (mono-quinazoline-Ru-conjugate and bis-quinazoline-Ru-conjugate, respectively). The bis-quinazoline-Ru-conjugate, which retains an essential inhibitory activity, was found by fluorescence imaging to be effectively uptaken by Uppsala 87 malignant glioma (grade IV malignant glioma) cells. The fluorescence imaging study and a time-resolved fluorescence resonance energy transfer study indicated a specific subcellular distribution of the conjugate that coincides with that of a mitochondria-targeted dye, suggesting mitochondrial localization of the conjugate and potential association with mitochondria-translocated forms of EGFR. Mitochondrial localization was further documented by the specific concentration of the bis-quinazoline-Ru-conjugate in a mitochondrial isolation assay.

Enhancement of O-atom density through collisions with Ne by laser-produced plasma in Ne–O2 gas mixtures and possible energy transfer mechanism

Laser-produced plasma in Ne and O2 gases and Ne–O2 gas mixture with different O2 fractions have been investigated. The plasma were produced by focusing a laser beam of 5 ns pulse duration from a Nd:YAG laser ([Formula: see text] = 1064 nm) through a lens of 5 cm focal length into the chamber filled with different gas species at different pressures. Possible enhancement in O-atom densities through collisions with metastable Ne atoms by the laser-created plasma in Ne–O2 gas mixtures and possible energy transfer mechanism was studied. Study of energy transfer through collisions was carried out by comparisons of the line intensities of the emitted spectra from laser-created plasma in gas mixtures and pure gases with the technique of optical emission spectroscopy (OES). Strong evidence of energy transfer from Ne to O was recorded. From the result, it was suggested that the high-lying metastable levels of Ne were responsible for enhancement of O-atoms density in gas mixture and Ne also play important role in energy transfer mechanism through collision. Also, behaviors of the line intensities under different laser energies were studied. Behaviors of line intensities and line widths were the main parameters measured. Stark broadening of lines in Ne with different laser energies was recorded. The electron temperature T[Formula: see text] and number density N[Formula: see text] were found to be 1.01 eV and 9.44 × 10[Formula: see text] cm[Formula: see text] in Ne at different laser energy/pulse with total pressure of 1000 mbar.

The study of heat energy transfer through the porous structure of the intermetallide catalyst

Abstract. Purpose. The purpose of the work is to find verified dependences for the calculation of heat and mass exchange processes in the porous structures of intermetallide catalysts, as well as to establish interdependences between the structure of the catalyst and its thermal characteristics. Methodology. The object of study was selected intermetallide catalysts of the Ni−Al system with a various granule filling scheme: in-line and staggered arrangement. To simulate the processes of heat and mass exchange, computer simulation with grid methods was used. To obtain experimental data, tests of a known composition of the catalyst obtained under thermochemical pressing were carried out. The catalytic activity and specific surface area of the catalyst obtained were evaluated. Findings. It was established that the staggered arrangement of the catalyst granules exhibits a large catalytic activity already in the initial period of time, its activity gradually increases with increasing temperature, reaching a maximum value in the investigated temperature range at T = 300 °C. The conversion of carbon monoxide at the staggered arrangement in the initial oxidation period exceeds NiAl 3 in-line arrangement by 1.3…1.5 times. However, the use of a staggered intermetallide catalyst backfill as a catalyst in the oxidation of carbon monoxide will be subjected to coking to much greater extent than a in-line backfill (high density of backfill), as a result of which it will be deactivated much faster. Originality. Research largely eliminates the gap formed between the practice of formation of thermophysical properties and information about changes in the structure and properties of intermetallide catalysts. Practical value. Research allows us to expand the scope of high-performance methods for producing porous intermetallide alloys in the technology of catalysts and to improve their quality.

Elucidation of the association of potential chemotherapeutic alkaloid chelerythrine with bovine hemoglobin by experimental probing and molecular docking simulation

Chelerythrine (CHL) is a pharmacologically important molecule that appears in positively charged iminium and neutral alkanolamine form on varying the pH. Association of bovine hemoglobin (BHb) with iminium and alkanolamine forms of CHL is explored employing several spectroscopic and theoretical tools. Our results revealed that iminium form of CHL shows greater binding affinity than the neutral alkanolamine form, with nearly one binding site on the protein for both forms. Thermodynamic data showed that the iminium binding to BHb was characterized by negative enthalpy and positive entropy changes while the association of the alkanolamine CHL was accompanied with both positive enthalpy and entropy changes. Both forms of CHL have been found to quench the intrinsic fluorescence of BHb. From Förster's resonance energy transfer (FRET) studies, the binding distance between the energy acceptor (CHL) and donor (β–Trp 37 of BHb) was found to be optimum for fluorescence quenching to occur. The conformational transformation of BHb induced by CHL complexation showed greater unfolding of the protein architecture for the iminium interaction from CD spectroscopy. Molecular docking study revealed that both iminium and alkanolamine form of CHL reside near β–Trp 37 at the α1β2 interface of BHb.

Evaluation of the energy transfer mechanism leading to tunable green-to-red cooperative up-conversion emission in Eu3+-Yb3+ co-doped CaF2 powders

The luminescence from rare-earth doped alkali earth metal fluorides has been studied for applications in photonics such as lamp and display technologies. In this context, the study of energy transfer (ET) processes among rare-earth ions is of great importance. Here, we report the study of the ET mechanisms involving Eu3+ and Yb3+ in CaF2 powders prepared by combustion synthesis. Cooperative up-conversion (UC) luminescence could be tuned between green and red colors by adjusting the doping concentrations of the rare-earth ions. The energy transfer rate from pairs of Yb3+ to Eu3+ was estimated by use of a rate-equation set for the relevant 4f electronic populations engaged in the UC production.

Positively charged amino acid residues in the extracellular loops A and C of lens aquaporin 0 interact with the negative charges in the plasma membrane to facilitate cell-to-cell adhesion

This investigation was undertaken to find out whether the positive charges in the Extracellular Loops A (ELA) and C (ELC) of Aquaporin 0 (AQP0) are involved in lens fiber cell-to-cell adhesion (CTCA), and the possible mechanism of CTCA. AQP0 ELA or ELC was substituted with the corresponding AQP1 loop via Polymerase Chain Reaction. Positively charged arginine (R) and histidine (H) of mouse AQP0 ELA and ELC were substituted individually with glutamine (Q) to create R33Q, H40Q, R113Q and H122Q by mutagenesis. cRNA expression, immunostaining, Förster Resonance Energy Transfer (FRET) studies and protein analyses showed localization of all mutants except AQP0-AQP1ELC chimera (AQP0 ELC substituted with AQP1 ELC) at the plasma membrane. Osmotic Swelling Assay revealed comparable water permeability (Pf) among AQP0-AQP1ELA, R33Q, R113Q, and WT. CTCA assay demonstrated a significant reduction in adhesion in all mutants compared to the WT (14–73%) suggesting the importance of the conserved positively charged residues of ELA and ELC for adhesion. Studies involving AQP0-transfected L-cells, and lipid vesicles indicated that CTCA was due to the electrostatic interaction between the positively charged amino acids of AQP0 extracellular loops and the negative charges of the plasma membrane. Schematic models are provided to illustrate the mechanism.

Two-Dimensional Electronic Spectroscopy Reveals the Spectral Dynamics of Förster Resonance Energy Transfer

Summary Two-dimensional electronic spectroscopy (2D ES) probes the energies of chromophores and their coupling, and therefore, the technique is now widely used for studying excitation-energy-transfer mechanisms. The ubiquity and importance of Forster resonance energy transfer (FRET) demand a thorough study of its signatures in 2D ES. Here, using principles from noisy-light spectroscopy to account for the spontaneous transfer event, we describe a model of the signals that arise from FRET in 2D ES. This model yields three theoretical results regarding the energy-transfer peak, which are consistent with our laboratory measurements. A second unanticipated finding is that the solvation processes that give rise to the dynamic Stokes shift of the acceptor signal also induce a relatively slower redshift of the energy-transfer signal, revealing a fundamental difference in solvation relaxation between photoexcited and FRET-excited acceptor molecules. The signatures derived from the model serve as a benchmark for ongoing work on energy-transfer mechanisms. Here, Turner and colleagues develop a noisy-light-inspired model of FRET in 2D ES to account for the vibrations that activate it. Crucially, they reveal several unreported features that distinguish FRET from other signals. These signatures are fundamental and immediately applicable to ongoing work on photosynthetic complexes, solar nanomaterials, and other renewable energy focal points. Future interdisciplinary work ranging from studies of energy transfer in organisms to medically applicable bio-imaging methodologies will take advantage of these spectral and temporal signatures.

Single-molecule insights into the temperature and pressure dependent conformational dynamics of nucleic acids in the presence of crowders and osmolytes

In this review we discuss results from temperature and pressure dependent single-molecule Förster resonance energy transfer (smFRET) studies on nucleic acids in the presence of macromolecular crowders and organic osmolytes. As representative examples, we have chosen fragments of both DNAs and RNAs, i.e., a synthetic DNA hairpin, a human telomeric G-quadruplex and the microROSE RNA hairpin. To mimic the effects of intracellular components, our studies include the macromolecular crowding agent Ficoll, a copolymer of sucrose and epichlorohydrin, and the organic osmolytes trimethylamine N-oxide, urea and glycine as well as natural occurring osmolyte mixtures from deep sea organisms. Furthermore, the impact of mutations in an RNA sequence on the conformational dynamics is examined. Different from proteins, the effects of the osmolytes and crowding agents seem to strongly dependent on the structure and chemical make-up of the nucleic acid.

Local approach to the study of energy transfers in incompressible magnetohydrodynamic turbulence.

We present a local approach to the study of scale-to-scale energy transfers in magnetohydrodynamic (MHD) turbulence. This approach is based on performing local averages of the physical fields, which amounts to filtering scales smaller than some parameter ℓ. A key step in this work is the derivation of a local Kármán-Howarth-Monin relation which provides a local form of Politano and Pouquet's 4/3 law, without any assumption of homogeneity or isotropy. Our approach is exact and nonrandom, and we show its connection to the usual statistical results of turbulence. Its implementation on data obtained via a three-dimensional direct numerical simulation of the forced incompressible MHD equations from the John Hopkins turbulence database constitutes the main part of our study. First, we show that the local Kármán-Howarth-Monin relation holds well. The space statistics of local cross-scale transfers are studied next, their means and standard deviations being maximum at inertial scales and their probability density functions (PDFs) displaying very wide tails. Events constituting the tails of the PDFs are shown to form structures of strong transfers, either positive or negative, which can be observed over the whole available range of scales. As ℓ is decreased, these structures become more and more localized in space while contributing to an increasing fraction of the mean energy cascade rate. Finally, we highlight their quasi-one-dimensional (filamentlike) or quasi-two-dimensional (sheetlike or ribbonlike) nature and show that they appear in areas of strong vorticity or electric current density.

Experimental study of energy transfer in double shell implosions

Advances in target fabrication have made double shell capsule implosions a viable platform to study burning fusion plasmas. Central to the double shell capsule is a high-Z (e.g., Au) metal pusher that accesses the volume-burn regime by reducing radiative losses through radiation trapping and compressing a uniform fuel volume at reduced velocities. A double shell implosion relies on a series of energy transfer processes starting from x-ray absorption by the outer shell, followed by transfer of kinetic energy to an inner shell, and finally conversion of kinetic energy to fuel internal energy. We present simulation and experimental results on momentum transfer to different layers in a double shell. We also present the details of the development of the NIF cylindrical hohlraum double shell platform including an imaging shell design with a mid-Z inner shell necessary for imaging the inner shell shape and the trajectory with the current 2DConA platform capability. We examine 1D energy transfer between shell layers using trajectory measurements from a series of surrogate targets; the series builds to a complete double shell layer by layer, isolating the physics of each step of the energy transfer process. The measured energy transfer to the foam cushion and the inner shell suggests that our radiation-hydrodynamics simulations capture most of the relevant collision physics. With a 1 MJ laser drive, the experimental data indicate that 22% ± 3% of the ablator kinetic energy couples into inner shell KE, compared to a 27% ± 2% coupling in our xRAGE simulations. Thus, our xRAGE simulations match experimental energy transfer to ∼5%, without inclusion of higher order 2D and 3D effects.

Genetic Incorporation of Noncanonical Amino Acids Using Two Mutually Orthogonal Quadruplet Codons.

Genetic incorporation of noncanonical amino acids has emerged as a powerful tool for the study of protein structure and function. While the three triplet nonsense codons have been widely explored, quadruplet codons have attracted attention for the potential of creating additional blank codons for noncanonical amino acid mutagenesis. Here we demonstrated for the first time that two orthogonal quadruplet codons could be used to simultaneously encode two different noncanonical amino acids within a single protein in bacterial cells. To achieve this, we fine-tuned the interaction between aminoacyl-tRNA synthetase and tRNA, which afforded up to 21-fold improvement in quadruplet codon decoding efficiency. This work represents a significant step toward the use of multiple quadruplet codons for noncanonical amino acid mutagenesis. Simultaneous incorporation of two or more noncanonical amino acids is of significant importance for biological applications that can benefit from multiple unique functional groups, such as fluorescence resonance energy transfer and nuclear magnetic resonance studies, and ultimately for the synthesis of completely unnatural biopolymers as new biomaterials.