Electrocatalytic Reduction of Nitrogen to Ammonia Using Tiara-like Phenylethanethiolated Nickel Cluster.

The fixing of N2 to NH3 is challenging due to the inertness of the N≡N bond. Commercially, ammonia production depends on the energy-consuming Haber-Bosch (H-B) process, which emits CO2 while using fossil fuels as the sources of hydrogen and energy. An alternative method for NH3 production is the electrochemical nitrogen reduction reaction (NRR) process as it is powered by renewable energy sources. Here, we report a tiara-like nickel-thiolate cluster, [Ni6 (PET)12 ] (where, PET=2-phenylethanethiol)] as an efficient electro-catalyst for the electrochemical NRR at ambient conditions. Ammonia (NH3 : 16.2±0.8 µg h-1 cm-2 ) was the only nitrogenous product over the potential of -2.3 V vs. Fc + /Fc with a Faradaic efficiency of 25%±1.7. Based on theoretical calculations, NRR by [Ni6 (PET)12 ] proceeds through both the distal and alternating pathways with an onset potential of -1.84 V vs. RHE (i.e., -2.46 V vs. Fc + /Fc ) which corroborates with the experimental findings.

Dysphagia and disability in minor strokes - An institutional study.

BACKGROUND: Minor strokes, defined as NIHSS ≤5 are considered non-disabling, associated with a favourable outcome. AIM: Our aim was to study prevalence and predictors of dysphagia in patients with minor stroke and its impact on functional outcome. METHODS: Single centre retrospective study of all minor strokes admitted to Comprehensive Stroke care centre with 1 year completed follow-up were recruited. Clinical and imaging details and follow-up data were extracted from medical records. RESULTS: We had 147 patients with minor stroke, 72.1% men with median age 61 years. 71% presented within 24 h of symptom onset. Most common etiology was lacunar .Median NIHSS at admission was 3(IQR 2). 85 patients had anterior circulation strokes and 34 had chronic infarcts in imaging.19 had significant dysphagia and 10 were discharged with nasogastric feeding tube. Admission NIHSS and white mater changes in imaging were predictive of post stroke dysphagia. Excellent recovery of dysphagia was found within 1 month post stroke in all, except one who required percutaneous gastrostomy. At 3 months 76% had excellent outcome. Presence of dysphagia and diabetes were found to be predictive of short term outcome, independent of admission stroke severity. At 12 months, post stroke dysphagia, female gender and white mater changes in imaging were predictive of unfavourable outcome. CONCLUSIONS: Minor strokes are disabling in a small fraction of patients. Over 10% of them can have significant post stroke dysphagia necessitating nasogastric feeding short term. This patient subgroup tend to have less favourable outcome on short and long term follow-up.

Observation of short range ferromagnetic interactions and magnetocaloric effect in cobalt substituted Gd5Si2Ge2.

We report on the observation of double transition - a first order and a second order transition in Gd5Si2-xCoxGe2 with x = 0, 0.1, 0.2 and 0.4 with the appearance of short-range ferromagnetic correlations. The first order phase transition is due to a combined magnetostructural transition from monoclinic paramagnetic phase to orthorhombic ferromagnetic phase on cooling while the second order transition arises from an orthorhombic paramagnetic to ferromagnetic phase on cooling. Structural studies show that the substituted compounds crystallize in a combination of Gd5Si2Ge2 and Gd5Si4 phases. Low-temperature X-ray diffraction measurements confirm the complete transformation from monoclinic to orthorhombic phase. DC magnetization measurements reveal an anomalous low field magnetic behaviour indicating a Griffiths-like phase. This unusual behaviour is attributed to the local disorder within the crystallographic structure indicating the presence of short-range magnetic correlations and ferromagnetic clustering, which is stabilized and enhanced by competing intra-layer and inter-layer magnetic interactions. The magnetostructural transition results in entropy changes (-ΔSM) of 9 J kg-1 K-1 at 260 K for x = 0.1, 8.5 J kg-1 K-1 at 245 K for x = 0.2 and 4.2 J kg-1 K-1 at 210 K for x = 0.4 for a field change of 50 kOe. Co substitution induces compelling crystallographic and magnetoresponsive effects in the Gd-Si-Ge system, which could be useful for potential and smart applications such as solid-state magnetic refrigeration and sensitive magnetic switching from paramagnetic to ferromagnetic state. Universal curve analysis has been carried out on the substituted samples to study the order of the magnetic transition.

Time-of-flight detection of ultra-cold atoms using resonant frequency modulation imaging.

Resonant frequency modulation imaging is used to detect free falling ultra-cold atoms. A theoretical comparison of fluorescence imaging (FI) and frequency modulation imaging (FMI) is made, indicating that for low optical depth clouds, FMI accomplished a higher signal-to-noise ratio under conditions necessary for a 200 µm spatially resolved atom interferometer. A 750 ms time-of-flight measurement reveals near atom shot-noise limited number measurements of 2×106 Bose-condensed Rb87 atoms. The detection system is applied to high precision spinor BEC based atom interferometer.

Non-destructive shadowgraph imaging of ultra-cold atoms.

An imaging system is presented that is capable of far-detuned non-destructive imaging of a Bose-Einstein condensate with the signal proportional to the second spatial derivative of the density. Whilst demonstrated with application to Rb85, the technique generalizes to other atomic species and is shown to be capable of a signal-to-noise of ∼25 at 1 GHz detuning with 100 in-trap images showing no observable heating or atom loss. The technique is also applied to the observation of individual trajectories of stochastic dynamics inaccessible to single shot imaging. Coupled with a fast optical phase locked loop, the system is capable of dynamically switching to resonant absorption imaging during the experiment.

Simultaneous Precision Gravimetry and Magnetic Gradiometry with a Bose-Einstein Condensate: A High Precision, Quantum Sensor.

A Bose-Einstein condensate is used as an atomic source for a high precision sensor. A 5×10^{6} atom F=1 spinor condensate of ^{87}Rb is released into free fall for up to 750 ms and probed with a T=130 ms Mach-Zehnder atom interferometer based on Bragg transitions. The Bragg interferometer simultaneously addresses the three magnetic states |m_{f}=1,0,-1⟩, facilitating a simultaneous measurement of the acceleration due to gravity with a 1000 run precision of Δg/g=1.45×10^{-9} and the magnetic field gradient to a precision of 120 pT/m.

Ulipristal acetate versus placebo for fibroid treatment before surgery.

BACKGROUND: The efficacy and safety of oral ulipristal acetate for the treatment of symptomatic uterine fibroids before surgery are uncertain. METHODS: We randomly assigned women with symptomatic fibroids, excessive uterine bleeding (a score of >100 on the pictorial blood-loss assessment chart [PBAC, an objective assessment of blood loss, in which monthly scores range from 0 to >500, with higher numbers indicating more bleeding]) and anemia (hemoglobin level of ≤10.2 g per deciliter) to receive treatment for up to 13 weeks with oral ulipristal acetate at a dose of 5 mg per day (96 women) or 10 mg per day (98 women) or to receive placebo (48 women). All patients received iron supplementation. The coprimary efficacy end points were control of uterine bleeding (PBAC score of <75) and reduction of fibroid volume at week 13, after which patients could undergo surgery. RESULTS: At 13 weeks, uterine bleeding was controlled in 91% of the women receiving 5 mg of ulipristal acetate, 92% of those receiving 10 mg of ulipristal acetate, and 19% of those receiving placebo (P<0.001 for the comparison of each dose of ulipristal acetate with placebo). The rates of amenorrhea were 73%, 82%, and 6%, respectively, with amenorrhea occurring within 10 days in the majority of patients receiving ulipristal acetate. The median changes in total fibroid volume were -21%, -12%, and +3% (P=0.002 for the comparison of 5 mg of ulipristal acetate with placebo, and P=0.006 for the comparison of 10 mg of ulipristal acetate with placebo). Ulipristal acetate induced benign histologic endometrial changes that had resolved by 6 months after the end of therapy. Serious adverse events occurred in one patient during treatment with 10 mg of ulipristal acetate (uterine hemorrhage) and in one patient during receipt of placebo (fibroid protruding through the cervix). Headache and breast tenderness were the most common adverse events associated with ulipristal acetate but did not occur significantly more frequently than with placebo. CONCLUSIONS: Treatment with ulipristal acetate for 13 weeks effectively controlled excessive bleeding due to uterine fibroids and reduced the size of the fibroids. (Funded by PregLem; ClinicalTrials.gov number, NCT00755755.).

Strategies to alleviate distortive phase transformations in Li-ion intercalation reactions: an example with vanadium pentoxide.

Chemical and electrochemical Li-ion insertion in transition metal oxides, either via a phase transformation reaction (ions insert into specific crystallographic sites of the host lattice) or a solid solution insertion (ions distribute uniformly throughout the host lattice), enables high energy density electrochemical energy storage. Many phase transformation cathode materials, that undergo two-phase reactions, exhibit high theoretical capacities arising from multi-electron redox reactions. However, challenges in distortive phase transformations and uncontrolled phase nucleation, propagation, segregation, and co-existence continue to limit the energy density, (dis)charging rate performances, and cycling stability of available phase transformation cathode materials. Vanadium pentoxide (V2O5), a classical layered intercalation host material with high theoretical capacity, undergoes irreversible structural changes and capacity fading when intercalating more than one lithium ion per V2O5 unit in its thermodynamically stable phase. Here, we review recent synthetic strategies to alter the V-O connectivity, thereby alleviating distortive phase transformations and promoting solid solution-based Li-ion insertion in V2O5. We also summarize several widely accessible and classical molecular-based analytical tools that can provide local structural dynamics and phase transformation mechanism information on the lithiation of V2O5, including single-crystal X-ray diffraction, infrared and Raman spectroscopy, electron paramagnetic resonance, and nuclear magnetic resonance spectroscopy.

Control over product formation and thermodynamic stability of thiolate-protected gold nanoclusters through tuning of surface protecting ligands.

Surface-protecting ligands can regulate the structure of a cluster's core either through electronic or steric effects. However, the influence of the steric effect along with the electronic effect over controlling the structure during ligand exchange reactions remains elusive. To understand this, we have carried out ligand exchange on [Au23(CHT)16]- (CHT: cyclohexane thiol) using aromatic thiolates where we have tuned the bulkiness at the para position of the thiolate group on the incoming ligands. The outcome of the experiments reveals that each of the ligands in the chosen series is precisely selective towards the parent cluster transformation through specific intermediates. The ligand with more steric crowding directed the reaction pathway to have Au28 nanocluster as the major product while Au36 was the final product obtained with the gradual decrease of bulkiness over the ligand. The combined experimental and theoretical results elucidated the mechanism of the reaction pathways, product formation, and their stability. Indeed, this study with the series of ligands will add up to the ligand library, where we can decide on the ligand to obtain our desired cluster for specific applications through the ligand exchange reaction.

Reversible polymorphic structural transition of crown-like nickel nanoclusters and its effect on conductivity.

We report the reversible polymorphic phase transition of [Ni6(PET)12] (PET = phenylethanethiol) and its effect on the conductivity. This cluster's self-assembly leads to two polymorphic structures with distinct conductivity, caused by variation of the non-covalent SS interactions. These results enlighten the effect of non-covalent interactions on conductivity.

Frequency of and Factors Associated With Nonmedical Opioid Use Behavior Among Patients With Cancer Receiving Opioids for Cancer Pain.

IMPORTANCE: One of the main aims of research on nonmedical opioid use (NMOU) is to reduce the frequency of NMOU behaviors through interventions such as universal screening, reduced opioid exposure, and more intense follow-up of patients with elevated risk. The absence of data on the frequency of NMOU behavior is the major barrier to conducting research on NMOU. OBJECTIVE: To determine the overall frequency of and the independent predictors for NMOU behavior. DESIGN, SETTING, AND PARTICIPANTS: In this prognostic study, 3615 patients with cancer were referred to the supportive care center at MD Anderson Cancer Center from March 18, 2016, to June 6, 2018. Patients were eligible for inclusion if they had cancer and were taking opioids for cancer pain for at least 1 week. Patients were excluded if they had no follow-up within 3 months of initial consultation, did not complete the appropriate questionnaire, or did not have scheduled opioid treatments. After exclusion, a total of 1554 consecutive patients were assessed for NMOU behavior using established diagnostic criteria. All patients were assessed using the Edmonton Symptom Assessment Scale, the Screener and Opioid Assessment for Patients with Pain (SOAPP), and the Cut Down, Annoyed, Guilty, Eye Opener-Adapted to Include Drugs (CAGE-AID) survey. Data were analyzed from January 6 to September 25, 2020. RESULTS: A total of 1554 patients (median [interquartile range (IQR)] age, 61 [IQR, 52-69] years; 816 women [52.5%]; 1124 White patients [72.3%]) were evaluable for the study, and 299 patients (19.2%) had 1 or more NMOU behaviors. The median (IQR) number of NMOU behaviors per patient was 1 (IQR, 1-3). A total of 576 of 745 NMOU behaviors (77%) occurred by the first 2 follow-up visits. The most frequent NMOU behavior was unscheduled clinic visits for inappropriate refills (218 of 745 [29%]). Eighty-eight of 299 patients (29.4%) scored 7 or higher on SOAPP, and 48 (16.6%) scored at least 2 out of 4 points on the CAGE-AID survey. Results from the multivariate model suggest that marital status (single, hazard ratio [HR], 1.58; 95% CI, 1.15-2.18; P = .005; divorced, HR, 1.43; 95% CI, 1.01-2.03; P = .04), SOAPP score (positive vs negative, HR, 1.35; 95% CI, 1.04-1.74; P = .02), morphine equivalent daily dose (MEDD) (HR, 1.003; 95% CI, 1.002-1.004; P < .001), and Edmonton Symptom Assessment Scale pain level (HR, 1.11; 95% CI, 1.06-1.16; P < .001) were independently associated with the presence of NMOU behavior. In recursive partition analysis, single marital status, MEDD greater than 50 mg, and SOAPP scores greater than 7 were associated with a higher risk (56%) for the presence of NMOU behavior. CONCLUSIONS AND RELEVANCE: This prognostic study of patients with cancer taking opioids for cancer pain found that 19% of patients developed NMOU behavior within a median duration of 8 weeks after initial supportive care clinic consultation. Marital status (single or divorced), SOAPP score greater than 7, higher levels of pain severity, and MEDD level were independently associated with NMOU behavior. This information will assist clinicians and investigators designing clinical and research programs in this important field.

Orthorhombic crystal structure and oxygen deficient cluster distribution model for YBa2Cu3-xAlxO6+δ superconductor.

Single crystal x-ray diffraction measurements on both as-grown as well as oxygenated single crystals of an aluminium doped high temperature superconductor YBa2Cu3-xAlxO6+δ revealed the crystal structure to be orthorhombic with space group Pmmm, in contrast to, tetragonal crystal structures corresponding to space group P4/mmm, previously reported for as-grown YBa2Cu3-xAlxO6+δ, and conflicting structures on oxygenated YBa2Cu3-xAlxO6+δ. The orthorhombic crystal structure was confirmed by powder x-ray diffraction that showed the presence of two peaks corresponding to (020) and (200) reflections associated with orthorhombic structures of space group Pmmm, instead of a single (200) reflection corresponding to tetragonal crystal structures with space group P4/mmm. All the as-grown crystals were found to be superconducting. An oxygen-vacancy cluster distribution model is proposed to explain the differences in the obtained magnetisation hysteresis loop and the broad superconducting transition temperature. The model proposes the existence of two oxygen deficient clusters of (Al-..-Cu-O-Cu)n and (Cu-O-Cu-..)n juxtaposed with each other whose number and size vary as the as-grown single crystals of YBa2Cu3-xAlxO6+δ are subjected to oxygenation. X-ray photoelectron spectroscopy measurements showed the existence of two distinct peaks in each of the spectrum of O, Cu, Y and Ba in YBa2Cu3-xAlxO6+δ crystals corresponding to the two different types of clusters. The relative intensities of each XPS peak was found to decrease in the oxygenated crystals as compared to the as-grown ones confirming the change in the number and size of clusters in the as-grown crystals after oxygenation.

An atomic Fabry-Perot interferometer using a pulsed interacting Bose-Einstein condensate.

We numerically demonstrate atomic Fabry-Perot resonances for a pulsed interacting Bose-Einstein condensate (BEC) source transmitting through double Gaussian barriers. These resonances are observable for an experimentally-feasible parameter choice, which we determined using a previously-developed analytical model for a plane matter-wave incident on a double rectangular barrier system. Through numerical simulations using the non-polynomial Schödinger equation-an effective one-dimensional Gross-Pitaevskii equation-we investigate the effect of atom number, scattering length, and BEC momentum width on the resonant transmission peaks. For [Formula: see text]Rb atomic sources with the current experimentally-achievable momentum width of [Formula: see text] [[Formula: see text]], we show that reasonably high contrast Fabry-Perot resonant transmission peaks can be observed using (a) non-interacting BECs, (b) interacting BECs of [Formula: see text] atoms with s-wave scattering lengths [Formula: see text] ([Formula: see text] is the Bohr radius), and (c) interacting BECs of [Formula: see text] atoms with [Formula: see text]. Our theoretical investigation impacts any future experimental realization of an atomic Fabry-Perot interferometer with an ultracold atomic source.

Size Evolution Dynamics of Gold Nanoclusters at an Atom-Precision Level: Ligand Exchange, Growth Mechanism, Electrochemical, and Photophysical Properties.

Interpretation of size evolution is an essential part of nanocluster transformation processes for unraveling the mechanism at an atom-precision level. Here we report the transformation of a non-superatomic Au23 to a superatomic Au36 nanocluster via Au28 cluster formation, activated by the bulky 4-tert-butylbenzenethiol ligand. Time-dependent matrix-assisted laser desorption ionization mass spectrometry data revealed that the conversion proceeds through ligand exchange followed by the size focusing method, ultimately leading to size growth. We also validated this transformation through time-dependent ultraviolet-visible data. Density functional theory calculations predicted that the kernel of the Au28 cluster evolved through a linear combination of molecular orbitals of the fragment of 2e- units (Au42+ and Au3+) from the kernel of the Au23 cluster. Periodic growth of gold cores through continuous growth of Au4 tetrahedral unit leads to the formation of the Au36 cluster from the Au28 cluster. These results reinforce the plausibility of size evolution through the growth mechanism during the transformation process. Differential pulse voltammetry studies showed that the highest occupied molecular orbital-lowest unoccupied molecular orbital gap inversely varies with the kernel size of these clusters. Photophysical experiments support the molecular-like intersystem crossing rather than core-shell relaxation to these clusters. The trends of photoluminescence lifetime were found to be the reverse of those of the energy gap law. The increment of lifetimes for the larger cluster can be mainly due to the contribution of both hot carriers and band-edge carriers.

Synergistic Effect of Bridging Thiolate and Hub Atoms for the Aromaticity Driven Symmetry Breaking in Atomically Precise Gold Nanocluster.

The symmetry of atomically precise nanoclusters is influenced by the specific geometry of the kernel and the arrangement of staple motifs. To understanding the role of ligand and its effect on the breaking of symmetry during ligand exchange transformation, it is necessary to have a mechanism of transformation in an atomically precise manner. Herein, we report the structural transformation from bipyramidal kernel to icosahedral kernel via ligand exchange. The transformation of [Au23(CHT)16]- to [Au25(2-NPT)18]- through ligand (aromatic) exchange revealed two important principles. First, the combined effort of experimental and theoretical study on structural analysis elucidated the mechanism of this structural transformation where "bridging thiolate" and "hub" gold atoms play a crucial role. Second, we have found that the higher crystal symmetry of the Au23 cluster is broken to lower crystal symmetry during the ligand exchange process. This showed that during ligand exchange, the hub atoms and µ3-S atoms get distorted and contributed to the ligand-staple motif formation. These phenomena specified that the ligand effects might be the pivotal factor to impose lower symmetry of the crystal system in the product clusters.

Possible Effects of Perchlorate Contamination of Drinking Water on Thyroid Health.

BACKGROUND: Perchlorate is an anion that occurs as a contaminant in groundwater. It originates from the improper disposal of ammonium perchlorate, a component of rocket fuel. The objective of this study was to explore whether the exposure to perchlorate in drinking water had an impact on the thyroid function of the population residing near an ammonium perchlorate plant in Kerala. Methodology. Using an ecological study design, we compared the serum levels of thyroid-stimulating hormone, thyroxine, and thyroid peroxidase antibodies among a representative sample of 289 study subjects from the area surrounding the ammonium perchlorate enrichment plant to 281 study subjects in a control area. RESULTS: The perchlorate concentration in the groundwater varied from 1600 ppb to 57,000 ppb in the 10 samples from the contaminated area and was below 24 ppb in all locations in the control area. No significant differences were found in the mean serum TSH concentration and mean T4 levels between the subjects from the contaminated area and the control area. On regression analysis, perchlorate contamination was not found to be a significant predictor of TSH. CONCLUSION: This study did not find any significant association between perchlorate in drinking water and changes in thyroid hormone levels. Our findings indicate the need for further investigation of this hypothesis using urinary perchlorate as a measure of individual exposure.

A N,N-dimethylformamide protected rhodium nanocluster with engrossing optical properties and its application.

Here, we present the synthesis and characterization of a new N,N-dimethylformamide (DMF) protected rhodium nanocluster (Rh NC) and its interesting optical properties. These small clusters are emissive and exhibit inhomogeneous broadening. The origin of the inhomogeneous broadening and emission behavior were investigated through detailed photo-physical studies. In this study, we demonstrated that the charge transfer from ligand to metal (DMF to Rh) was the source of the emission. Interactions between the polar DMF protected Rh NC and the solvent in the ground state generate inhomogeneous broadening. We probed the emission behavior for the detection of toxic metal ions. Photo-physical studies established the static mechanism of this sensing behavior.

Identification of Intermediate Au22(SR)4(SR')14 Cluster on Ligand-Induced Transformation of Au25(SR)18 Nanocluster.

We report the ligand-exchange-induced transformation from an icosahedral Au25(SR)18 cluster (where SR = 2-phenylethanethiol (PET)) to a bitetrahedral Au22(SR)4(SR')14 cluster (where SR' = 4-tert-butylbenzenethiol (TBBT)). This partial exchange of the ligands was achieved by controlling the concentration of the incoming TBBT ligand. Being a bulky and aromatic ligand, TBBT can efficiently distort the atomic structure of the Au25PET18 cluster, resulting in Au22(PET)4(TBBT)14, which is highly stable and considered to be an intermediate with a bitetrahedral structure. Time-dependent mass spectrometry and optical spectroscopy revealed the dissociation of the parent cluster and gave a deep insight on the ligand-exchange mechanism. Theoretical calculations and extended X-ray absorption fine structure studies confirm the formation of the Au22 structure. Identifying the atomic structure of the intermediate species opens a new avenue to study the transformation of one cluster to another.

Aggregation induced non-emissive-to-emissive switching of molecular platinum clusters.

We show here for the first time the Aggregation Induced Emission (AIE) mechanism and solvatochromic impact on Pt-SG (SG-deprotonated glutathione) nanoclusters. In this work, the AIE properties of Pt-SG clusters were investigated through computational and spectroscopic investigations. Computational data established that aggregation triggers a distinct change in the frontier molecular orbitals (FMOs) from metal d-orbital centered FMOs in the monomer to metal-thiolate and thiolate centered FMOs in the dimer improving the radiative decay process. Solvent dependent photoluminescence studies proved that a Lewis-acidic environment can significantly perturb the metal-thiolate and thiolate centered FMOs that are involved in the electronic transitions as predicted by our computational work. These semiconducting clusters exhibit a large Stokes shift and zero spectral overlap between absorption and emission which makes this Pt-SG cluster an excellent material for solar concentrators and solid-state light emitters. This AIE-OFF-ON emission was utilized to delineate a proof-of-concept sensor device that is sensitive to temperature and an acid/base.

Optimizing long chain-polyunsaturated fatty acid synthesis in salmonids by balancing dietary inputs.

The increasing use of terrestrial plant lipids to replace of fish oil in commercial aquafeeds requires understanding synthesis and storage of long chain-polyunsaturated fatty acids (LC-PUFA) in farmed fish. Manipulation of dietary fatty acids may maximize tissue storage of LC-PUFA, through increased production and selective utilization. A data synthesis study was conducted to estimate optimal levels of fatty acids that may maximize the production and storage of LC-PUFA in the edible portion of salmonids. Data were compiled from four studies with Atlantic salmon, rainbow trout, and steelhead trout (total n = 180) which were fed diets containing different terrestrial-based oils to replace fish oil. LC-PUFA (%) were linearly correlated between diet and muscle tissue (p < 0.001; r2 > 44%), indicating proportional storage after consumption. The slope, or retention rate, was highest for docosahexaenoic acid (DHA) at 1.23, indicating that an additional 23% of DHA was stored in the muscle. Dietary saturated fatty acids were positively related to DHA stored in the muscle (p < 0.001; r2 = 22%), which may involve membrane structural requirements, as well as selective catabolism. DHA was found to be optimally stored with a dietary n-3: n-6 ratio of 1.03: 1. These new results provide a baseline of optimal dietary ratios that can be tested experimentally to determine the efficacy of balancing dietary fatty acids for maximum LC-PUFA storage.