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The development of new methods of catalyst synthesis with the potential to generate active site structures orthogonal to those accessible by traditional protocols is of great importance for discovering new materials for addressing challenges in the evolving energy and chemical economy. In this work, the generality of oxidative grafting of organometallic and well-defined molecular metal precursors onto redox-active surfaces such as manganese dioxide (MnO 2 ) and lithium manganese oxide (LiMn 2 O 4 ) is investigated. Nine molecular metal precursors are explored, spanning groups 4-11 and each of the three periods of the transition metal series. The byproducts of the oxidative grafting reaction, a mixture of protodemetalation and ligand homocoupling for several organometallic precursors, was found to provide insights into the mechanism of the grafting reaction, suggesting oxidation of both the metal d-orbitals, as well as the metal-carbon σ-bonds, resulting in ejection of the ligand radical fragment. Analysis of the supported structures and oxidation state by X-ray absorption spectroscopy (XAS) and X-ray photoelectron spectroscopy (XPS) suggests that several of the chemisorbed metal ions are intercalated into interstitial vacancies of the surface structure while other complexes form intact molecular fragments on the surface. Proof of concept for the use of this metalation protocol to generate diverse, metal-dependent catalytic performance is demonstrated by the application of these materials in the conversion of cyclohexane to K/A oil (cyclohexanol and cyclohexanone) with tert -butyl hydroperoxide, as well as in the low-temperature ( T ≤ 50 °C) oxidation of carbon monoxide to carbon dioxide.

Single-phase three-dimensional vanadium oxide (V 4 O 9 ) was synthesized by reduction of V 2 O 5 using a gas stream of ammonia/argon (NH 3 /Ar). The as-synthesized oxide, prepared by this simple gas reduction method was subsequently electrochemically transformed into a disordered rock salt type-"Li3.7V4O9" phase while cycling over the voltage window 3.5 to 1.8 V versus Li. The Li-deficient phase delivers an initial reversible capacity of ∼260 mAhg -1 at an average voltage of 2.5 V vs. Li + /Li 0 . Further cycling to 50 cycles yields a steady 225 mAhg -1 . Ex situ X-ray diffraction studies confirmed that (de) intercalation phenomena follows a solid-solution electrochemical reaction mechanism. As demonstrated, the reversibility and capacity utilization of this V 4 O 9 is found to be superior to battery grade, micron-sized V 2 O 5 cathodes in lithium cells., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Senguttuvan, Lee, Key and Johnson.)

A lithium-air battery based on lithium oxide (Li 2 O) formation can theoretically deliver an energy density that is comparable to that of gasoline. Lithium oxide formation involves a four-electron reaction that is more difficult to achieve than the one- and two-electron reaction processes that result in lithium superoxide (LiO 2 ) and lithium peroxide (Li 2 O 2 ), respectively. By using a composite polymer electrolyte based on Li 10 GeP 2 S 12 nanoparticles embedded in a modified polyethylene oxide polymer matrix, we found that Li 2 O is the main product in a room temperature solid-state lithium-air battery. The battery is rechargeable for 1000 cycles with a low polarization gap and can operate at high rates. The four-electron reaction is enabled by a mixed ion-electron-conducting discharge product and its interface with air.

Realization of practical sodium metal batteries (SMBs) is hindered due to lack of compatible electrolyte components, dendrite propagation, and poor understanding of anodic interphasial chemistries. Chemically robust liquid electrolytes that facilitate both favorable sodium metal deposition and a stable solid-electrolyte interphase (SEI) are ideal to enable sodium metal and anode-free cells. Herein we present advanced characterization of a novel fluorine-free electrolyte utilizing the [HCB 11 H 11 ] 1- anion. Symmetrical Na cells operated with this electrolyte exhibit a remarkably low overpotential of 0.032 V at a current density of 2.0 mA cm -2 and a high coulombic efficiency of 99.5 % in half-cell configurations. Surface characterization of electrodes post-operation reveals the absence of dendritic sodium nucleation and a surprisingly stable fluorine-free SEI. Furthermore, weak ion-pairing is identified as key towards the successful development of fluorine-free sodium electrolytes., (© 2022 Wiley-VCH GmbH.)

A proton magnetic resonance spectroscopy (MRS) technique was used to measure 13 C enrichments of glutamate and glutamine in a 3.5 × 1.8 × 2 cm 3 voxel placed in the dorsal anterior cingulate cortex of five healthy participants after oral administration of [U- 13 C]glucose. Strong pseudo singlets of glutamate and glutamine were induced to enhance the signal strength of glutamate and glutamine. This study demonstrated that 13 C labeling of glutamate and glutamine can be measured with the high sensitivity and spatial resolution of 1 H MRS using a proton-only MRS technique with standard commercial hardware. Furthermore, it is feasible to measure 13 C labeling of glutamate and glutamine in limbic structures, which play major roles in behavioral and emotional responses and whose abnormalities are involved in many neuropsychiatric disorders., (© 2022. The Author(s).)

A reliable energy storage ecosystem is imperative for a renewable energy future, and continued research is needed to develop promising rechargeable battery chemistries. To this end, better theoretical and experimental understanding of electrochemical mechanisms and structure-property relationships will allow us to accelerate the development of safer batteries with higher energy densities and longer lifetimes. This Review discusses the interplay between theory and experiment in battery materials research, enabling us to not only uncover hitherto unknown mechanisms but also rationally design more promising electrode and electrolyte materials. We examine specific case studies of theory-guided experimental design in lithium-ion, lithium-metal, sodium-metal, and all-solid-state batteries. We also offer insights into how this framework can be extended to multivalent batteries. To close the loop, we outline recent efforts in coupling machine learning with high-throughput computations and experiments. Last, recommendations for effective collaboration between theorists and experimentalists are provided.

Carbonic anhydrase (CA) plays an important role in many biological processes. Recent technological advances have demonstrated the feasibility of measuring CA activity in the occipital lobe of human subjects in vivo. In this work we report, for the first time, in vivo measurement of CA activity in the frontal lobe of human brain, where structural and function abnormalities are strongly associated with symptoms of major psychiatric disorders. Despite the much larger magnetic field distortion in the frontal lobe, the pseudo first-order bicarbonate dehydration rate constant was determined with high precision using in vivo 13 C magnetic resonance magnetization transfer spectroscopy following oral administration of [U- 13 C 6 ]glucose. Nuclear Overhauser effect pulses were used to increase the signal-to-noise ratio; no proton decoupling was applied. The unidirectional dehydration rate constant of bicarbonate was found to be 0.26 ± 0.07 s -1 , which is not statistically different from the dehydration rate constant in the occipital lobe determined in our previous study, indicating that CA activity in the two brain regions is essentially indistinguishable. These results demonstrate the feasibility of characterizing CA activity in the frontal lobe for future psychiatric studies., (Published 2021. This article is a U.S. Government work and is in the public domain in the USA.)

The main drawbacks of today's state-of-the-art lithium-air (Li-air) batteries are their low energy efficiency and limited cycle life due to the lack of earth-abundant cathode catalysts that can drive both oxygen reduction and evolution reactions (ORR and OER) at high rates at thermodynamic potentials. Here, inexpensive trimolybdenum phosphide (Mo 3 P) nanoparticles with an exceptional activity-ORR and OER current densities of 7.21 and 6.85 mA cm -2 at 2.0 and 4.2 V versus Li/Li + , respectively-in an oxygen-saturated non-aqueous electrolyte are reported. The Tafel plots indicate remarkably low charge transfer resistance-Tafel slopes of 35 and 38 mV dec -1 for ORR and OER, respectively-resulting in the lowest ORR overpotential of 4.0 mV and OER overpotential of 5.1 mV reported to date. Using this catalyst, a Li-air battery cell with low discharge and charge overpotentials of 80 and 270 mV, respectively, and high energy efficiency of 90.2% in the first cycle is demonstrated. A long cycle life of 1200 is also achieved for this cell. Density functional theory calculations of ORR and OER on Mo 3 P (110) reveal that an oxide overlayer formed on the surface gives rise to the observed high ORR and OER electrocatalytic activity and small discharge/charge overpotentials., (© 2020 Wiley-VCH GmbH.)

Due to their exceptional high energy density, lithium-ion batteries are of central importance in many modern electrical devices. A serious limitation, however, is the slow charging rate used to obtain the full capacity. Thus far, there have been no ways to increase the charging rate without losses in energy density and electrochemical performance. Here we show that the charging rate of a cathode can be dramatically increased via interaction with white light. We find that a direct exposure of light to an operating LiMn 2 O 4 cathode during charging leads to a remarkable lowering of the battery charging time by a factor of two or more. This enhancement is enabled by the induction of a microsecond long-lived charge separated state, consisting of Mn 4+ (hole) plus electron. This results in more oxidized metal centers and ejected lithium ions are created under light and with voltage bias. We anticipate that this discovery could pave the way to the development of new fast recharging battery technologies.

Objectives: Local anesthetic injection into the interspace between the popliteal artery and the posterior capsule of the knee (IPACK) has the potential to provide motor-sparing analgesia to the posterior knee after total knee arthroplasty. The primary objective of this cadaveric study was to evaluate injectate spread to relevant anatomic structures with IPACK injection., Methods: After receipt of Institutional Review Board Biospecimen Subcommittee approval, IPACK injection was performed on fresh-frozen cadavers. The popliteal fossa in each specimen was dissected and examined for injectate spread., Results: Ten fresh-frozen cadaver knees were included in the study. Injectate was observed to spread in the popliteal fossa at a mean ± SD of 6.1 ± 0.7 cm in the medial-lateral dimension and 10.1 ± 3.2 cm in the proximal-distal dimension. No injectate was noted to be in contact with the proximal segment of the sciatic nerve, but 3 specimens showed injectate spread to the tibial nerve. In 3 specimens, the injectate showed possible contact with the common peroneal nerve. The middle genicular artery was consistently surrounded by injectate., Conclusions: This cadaver study of IPACK injection demonstrated spread throughout the popliteal fossa without proximal sciatic involvement. However, the potential for injectate to spread to the tibial or common peroneal nerve was demonstrated. Consistent surrounding of the middle genicular artery with injectate suggests a potential mechanism of analgesia for the IPACK block, due to the predictable relationship between articular sensory nerves and this artery. Further study is needed to determine the ideal site of IPACK injection., (© 2018 by the American Institute of Ultrasound in Medicine.)

Objectives: To identify any anatomic barriers to local anesthetic spread between the sciatic nerve (SN) and the posterior femoral cutaneous nerve (PFCN) at the level of the infragluteal crease and to describe a potential technique for an ultrasound (US)-guided subgluteal PFCN block in a cadaveric model., Methods: Bilateral US-guided subgluteal injections of a colored latex solution were performed around the SN (15 mL) and PFCN (10 mL) in 4 unembalmed cadavers, for a total of 8 cadaver thighs. The specimens were dissected after latex polymerization to observe the spread of the latex solutions., Results: With US guidance, the PFCN was visualized deep to the gluteus maximus and slightly superficial or lateral to the SN at the level of the infragluteal crease. The SN and PFCN were found on dissection to be coated with their respective colored latex in all 8 thighs. The SN and PFCN were consistently separated by the deep investing muscular fascia of the thigh, with only 2 thighs showing substantial mixing of latex injectates., Conclusions: The deep investing muscular fascia of the thigh appears to impede the spread of injectate between the SN and PFCN in a most unembalmed cadaver specimens. A US-guided subgluteal PFCN blockade may be a feasible technique to complement an SN block when complete anesthesia of the posterior thigh is required., (© 2017 by the American Institute of Ultrasound in Medicine.)

Carbonic anhydrase plays important role in life. This study sought to demonstrate the feasibility of detecting carbonic anhydrase activity in the human brain in vivo. After oral administration of [U- 13 C 6 ]glucose, 13 C saturation transfer experiments were performed with interleaved control spectra and carbon dioxide saturation spectra. Proton nuclear Overhauser effect pulses were used to increase signal to noise ratio; no proton decoupling was applied. Results showed that the 13 C signal of bicarbonate was reduced by 72% ± 0.03 upon saturating carbon dioxide. The unidirectional dehydration rate constant of the carbonic anhydrase reaction was found to be 0.28 ± 0.02 sec -1 in the human brain. These findings demonstrate the feasibility of measuring carbonic anhydrase activity in vivo in the human brain, which makes it possible to characterize this important enzyme in patients with brain disorders.

Transition metal-containing polyanion compounds are attractive for use as cathode materials in sodium-ion batteries (SIB) because they possess elevated higher intrinsic electrochemical potentials versus oxide analogs given the same M n+/(n+1)+ redox couple, which leads to higher energy densities. NaMPO 4 (M = transition metal) compounds have a driving force to form into the electrochemically inactive maricite phase when using conventional methods. Herein we report on the synthesis of a NaCoPO 4 (NCP) polymorph ("Red"-phase) by a microwave-assisted solvothermal process at 200 °C using tetraethylene glycol as the solvent. Ex situ XRD, XANES, and electrochemical data are used to determine the reversibility of the Co 2+/3+ redox center.

Purpose: Carbon-13 ((13)C) MR spectroscopy (MRS) of the human brain at 7 Tesla (T) may pose patient safety issues due to high radiofrequency (RF) power deposition for proton decoupling. The purpose of present work is to study the feasibility of in vivo (13)C MRS of human brain at 7 T using broadband low RF power proton decoupling., Methods: Carboxylic/amide (13)C MRS of human brain by broadband stochastic proton decoupling was demonstrated on a 7 T scanner. RF safety was evaluated using the finite-difference time-domain method. (13)C signal enhancement by nuclear Overhauser effect (NOE) and proton decoupling was evaluated in both phantoms and in vivo., Results: At 7 T, the peak amplitude of carboxylic/amide (13)C signals was increased by a factor of greater than 4 due to the combined effects of NOE and proton decoupling. The 7 T (13)C MRS technique used decoupling power and average transmit power of less than 35 watts (W) and 3.6 W, respectively., Conclusion: In vivo (13)C MRS studies of human brain can be performed at 7 T, well below the RF safety threshold, by detecting carboxylic/amide carbons with broadband stochastic proton decoupling., (© 2015 Wiley Periodicals, Inc.)

Li- and Mn-rich layered oxides with composition xLi2MnO3·(1 -x)LiMO2 enable high capacity and energy density Li-ion batteries, but suffer from degradation with cycling. Evidence of atomic instabilities during the first charge are addressed in this work with X-ray absorption spectroscopy, first principles simulation at the GGA+U level, and existing literature. The pristine material of composition xLi2MnO3·(1 -x)LiMn0.5Ni0.5O2 is assumed in the simulations to have the form of LiMn2 stripes, alternating with NiMn stripes, in the metal layers. The charged state is simulated by removing Li from the Li layer, relaxing the resultant system by steepest descents, then allowing the structure to evolve by molecular dynamics at 1000 K, and finally relaxing the evolved system by steepest descents. The simulations show that about ¼ of the oxygen ions in the Li2MnO3 domains are displaced from their original lattice sites, and form oxygen-oxygen bonds, which significantly lowers the energy, relative to that of the starting structure in which the oxygen sublattice is intact. An important consequence of the displacement of the oxygen is that it enables about ⅓ of the (Li2MnO3 domain) Mn ions to migrate to the delithiated Li layers. The decrease in the coordination of the Mn ions is about twice that of the Ni ions. The approximate agreement of simulated coordination number deficits for Mn and Ni following the first charge with analysis of EXAFS measurements on 0.3Li2MnO3·0.7LiMn0.5Ni0.5O2 suggests that the simulation captures significant features of the real material.

Nanostructured bilayered V2O5 was electrochemically deposited within a carbon nanofoam conductive support. As-prepared electrochemically synthesized bilayered V2O5 incorporates structural water and hydroxyl groups, which effectively stabilizes the interlayers and provides coordinative preference to the Mg(2+) cation in reversible cycling. This open-framework electrode shows reversible intercalation/deintercalation of Mg(2+) ions in common electrolytes such as acetonitrile. Using a scanning transmission electron microscope we demonstrate that Mg(2+) ions can be effectively intercalated into the interlayer spacing of nanostructured V2O5, enabling electrochemical magnesiation against a Mg anode with a specific capacity of 240 mAh/g. We employ HRTEM and X-ray fluorescence (XRF) imaging to understand the role of environment in the intercalation processes. A rebuilt full cell was tested by employing a high-energy ball-milled Sn alloy anode in acetonitrile with Mg(ClO4)2 salt. XRF microscopy reveals effective insertion of Mg ions throughout the V2O5 structure during discharge and removal of Mg ions during electrode charging, in agreement with the electrode capacity. We show using XANES and XRF microscopy that reversible Mg intercalation is limited by the anode capacity.

As batteries become more powerful and utilized in diverse applications, thermal management becomes one of the central problems in their application. We report the results on thermal properties of a set of different Li-ion battery electrodes enhanced with multiwalled carbon nanotubes. Our measurements reveal that the highest in-plane and cross-plane thermal conductivities achieved in the carbon-nanotube-enhanced electrodes reached up to 141 and 3.6 W/mK, respectively. The values for in-plane thermal conductivity are up to 2 orders of magnitude higher than those for conventional electrodes based on carbon black. The electrodes were synthesized via an inexpensive scalable filtration method, and we demonstrate that our approach can be extended to commercial electrode-active materials. The best performing electrodes contained a layer of γ-Fe2O3 nanoparticles on carbon nanotubes sandwiched between two layers of carbon nanotubes and had in-plane and cross-plane thermal conductivities of ∼50 and 3 W/mK, respectively, at room temperature. The obtained results are important for thermal management in Li-ion and other high-power-density batteries.

Importance: Although clinical practice guidelines recommend combination therapy with macrolides, including azithromycin, as first-line therapy for patients hospitalized with pneumonia, recent research suggests that azithromycin may be associated with increased cardiovascular events., Objective: To examine the association of azithromycin use with all-cause mortality and cardiovascular events for patients hospitalized with pneumonia., Design: Retrospective cohort study comparing older patients hospitalized with pneumonia from fiscal years 2002 through 2012 prescribed azithromycin therapy and patients receiving other guideline-concordant antibiotic therapy., Setting: This study was conducted using national Department of Veterans Affairs administrative data of patients hospitalized at any Veterans Administration acute care hospital., Participants: Patients were included if they were aged 65 years or older, were hospitalized with pneumonia, and received antibiotic therapy concordant with national clinical practice guidelines., Main Outcomes and Measures: Outcomes included 30- and 90-day all-cause mortality and 90-day cardiac arrhythmias, heart failure, myocardial infarction, and any cardiac event. Propensity score matching was used to control for the possible effects of known confounders with conditional logistic regression., Results: Of 73,690 patients from 118 hospitals identified, propensity-matched groups were composed of 31,863 patients exposed to azithromycin and 31,863 matched patients who were not exposed. There were no significant differences in potential confounders between groups after matching. Ninety-day mortality was significantly lower in those who received azithromycin (exposed, 17.4%, vs unexposed, 22.3%; odds ratio [OR], 0.73; 95% CI, 0.70-0.76). However, we found significantly increased odds of myocardial infarction (5.1% vs 4.4%; OR, 1.17; 95% CI, 1.08-1.25) but not any cardiac event (43.0% vs 42.7%; OR, 1.01; 95% CI, 0.98-1.05), cardiac arrhythmias (25.8% vs 26.0%; OR, 0.99; 95% CI, 0.95-1.02), or heart failure (26.3% vs 26.2%; OR, 1.01; 95% CI, 0.97-1.04)., Conclusions and Relevance: Among older patients hospitalized with pneumonia, treatment that included azithromycin compared with other antibiotics was associated with a lower risk of 90-day mortality and a smaller increased risk of myocardial infarction. These findings are consistent with a net benefit associated with azithromycin use.

Introduction: Although some factors associated with rehospitalization after community-acquired pneumonia have been identified, other factors such as medical care utilization and medication usage have not been previously studied. We investigated novel predictors of rehospitalization in patients admitted with pneumonia., Methods: Using Department of Veteran Affairs (VA) administrative data from October 2001 to September 2007, we examined a cohort of patients 65 years old and older, who were hospitalized with pneumonia, in 150 VA acute care hospitals. The cohort was randomly split into derivation and validation samples, and then logistic regression models were used to identify and validate predictors of all-cause rehospitalization within 30 days., Results: Of the 45,134 subjects, 13% were rehospitalized within 30 days. No significant differences were noted between the derivation and validation cohorts. Factors associated with readmission included age, marital status, chronic renal disease, prior malignancy, nursing home residence, congestive heart failure, use of oral corticosteroids, number of emergency department visits a year prior, prior admission, number of outpatient clinic visits in a year prior, and length of hospital stay. The C statistics for the derivation and validation models were 0.615 and 0.613, respectively., Conclusions: Factors associated with readmission were largely unrelated to the underlying pneumonia, but were related to demographics, comorbidities, healthcare utilization, and length of stay on index admission., (2014 Society of Hospital Medicine. This article is a US government work and, as such, is in the public domain in the United States of America.)

Background: Mortality after pneumonia in immunocompromised patients is higher than for immunocompetent patients. The use of non-invasive mechanical ventilation for patients with severe pneumonia may provide beneficial outcomes while circumventing potential complications associated with invasive mechanical ventilation. The aim of our study was to determine if the use of non-invasive mechanical ventilation in elderly immunocompromised patients with pneumonia is associated with higher all-cause mortality., Methods: In this retrospective cohort study, data were obtained from the Department of Veterans Affairs administrative databases. We included veterans age ≥65 years who were immunocompromised and hospitalized due to pneumonia. Multilevel logistic regression analysis was used to determine the relationship between the use of invasive versus non-invasive mechanical ventilation and 30-day and 90-day mortality., Results: Of 1,946 patients in our cohort, 717 received non-invasive mechanical ventilation and 1,229 received invasive mechanical ventilation. There was no significant association between all-cause 30-day mortality and non-invasive versus invasive mechanical ventilation in our adjusted model (odds ratio (OR) 0.85, 95% confidence interval (CI) 0.66-1.10). However, those patients who received non-invasive mechanical ventilation had decreased 90-day mortality (OR 0.66, 95% CI 0.52-0.84). Additionally, receipt of guideline-concordant antibiotics in our immunocompromised cohort was significantly associated with decreased odds of 30-day mortality (OR 0.31, 95% CI 0.24-0.39) and 90-day mortality (OR 0.41, 95% CI 0.31-0.53)., Conclusions: Our findings suggest that physicians should consider the use of non-invasive mechanical ventilation, when appropriate, for elderly immunocompromised patients hospitalized with pneumonia.

The novel, lithium-rich oxide-phase Li₅FeO₄ (LFO) could, in theory, deliver a specific capacity >900 mAh/g when deployed as a cathode or cathode precursor in a battery with a lithium-based anode. However, research results to date on LFO indicate that less than one of the five Li⁺ cations can be reversibly de-intercalated/re-intercalated during repetitive charging and discharging cycles. In the present research, the system Li5+xFeO₄ with x values in the range of 0.0-2.0 was investigated by a combination of Raman and X-ray absorption spectroscopic methods supported by X-ray diffraction (XRD) analysis in order to determine if the Li₅FeO₄ lattice would accommodate additional Li⁺ ions, with concomitant lowering of the valence on the FeIII cations. Both the Raman phonon spectra and the XRD patterns were invariant for all values of x, strongly indicating that additional Li⁺ did not enter the Li₅FeO₄ lattice. Also, Raman spectral results and high-resolution synchrotron XRD data revealed the presence of second-phase Li₂O in all samples with x greater than 0.0. Synchrotron X-ray absorption spectroscopy at the Fe kα edge performed on the sample with a Li-Fe ratio of 7.0 (i.e., x = 2.0) showed no evidence for the presence of FeII. This resistance to accepting more lithium into the Li₅FeO₄ structure is attributed to the exceedingly stable nature of high-spin FeIII in tetrahedral "FeIIIO₄" structural units of Li₅FeO₄. Partial substitution of the FeIII with other cations could provide a path toward increasing the reversible Li⁺ content of Li5xFeO₄-type phases.

Material design in terms of their morphologies other than solid nanoparticles can lead to more advanced properties. At the example of iron oxide, we explored the electrochemical properties of hollow nanoparticles with an application as a cathode and anode. Such nanoparticles contain very high concentration of cation vacancies that can be efficiently utilized for reversible Li ion intercalation without structural change. Cycling in high voltage range results in high capacity (∼132 mAh/g at 2.5 V), 99.7% Coulombic efficiency, superior rate performance (133 mAh/g at 3000 mA/g) and excellent stability (no fading at fast rate during more than 500 cycles). Cation vacancies in hollow iron oxide nanoparticles are also found to be responsible for the enhanced capacity in the conversion reactions. We monitored in situ structural transformation of hollow iron oxide nanoparticles by synchrotron X-ray absorption and diffraction techniques that provided us clear understanding of the lithium intercalation processes during electrochemical cycling.

Tailoring nanoarchitecture of materials offers unprecedented opportunities in utilization of their functional properties. Nanostructures of vanadium oxide, synthesized by electrochemical deposition, are studied as a cathode material for rechargeable Na-ion batteries. Ex situ and in situ synchrotron characterizations revealed the presence of an electrochemically responsive bilayered structure with adjustable intralayer spacing that accommodates intercalation of Na(+) ions. Sodium intake induces organization of overall structure with appearance of both long- and short-range order, while deintercalation is accompanied with the loss of long-range order, whereas short-range order is preserved. Nanostructured electrodes achieve theoretical reversible capacity for Na(2)V(2)O(5) stochiometry of 250 mAh/g. The stability evaluation during charge-discharge cycles at room temperature revealed an efficient 3 V cathode material with superb performance: energy density of ~760 Wh/kg and power density of 1200 W/kg. These results demonstrate feasibility of development of the ambient temperature Na-ion rechargeable batteries by employment of electrodes with tailored nanoarchitectures., (© 2011 American Chemical Society)

Previously, we devised a novel strategy for in vivo 13C MRS using [2-13C]glucose infusion and low-power proton decoupling, and proposed that this strategy could be used to acquire 13C MR spectra from the frontal lobe of the human brain. Here, we demonstrate, for the first time, in vivo 13C MRS of human frontal lobe acquired at 3 T. Because the primary metabolites of [2-13C]glucose can be decoupled using very-low-radiofrequency power, we used a volume coil for proton decoupling in this study. The homogeneous B(1) field of the volume coil was found to significantly enhance the decoupling efficiency of the stochastic decoupling sequence. Detailed specific absorption rates inside the human head were analyzed using the finite difference time domain method to ensure experimental safety. In vivo 13C spectra from the occipital and frontal lobes of the human brain were obtained. At a decoupling power of 30 W (time-averaged power, 2.45 W), the spectra from the occipital lobe showed well-resolved spectral resolution and excellent signal-to-noise ratio. Although frontal lobe 13C spectra were affected by local B(0) field inhomogeneity, we demonstrated that the spectral quality could be improved using post-acquisition data processing. In particular, we showed that the frontal lobe glutamine C5 at 178.5 ppm and aspartate C4 at 178.3 ppm could be spectrally resolved with effective proton decoupling and B(0) field correction. Because of its large spatial coverage, volume coil decoupling provides the potential to acquire 13C MRS from more than one brain region simultaneously., (Copyright © 2010 John Wiley & Sons, Ltd.)

In rats, phasic external urethral sphincter (EUS) activity (bursting) is postulated to be crucial for efficient voiding. This has been reported to be lost after spinal cord transection (txSCI), contributing to impaired function. However, anesthesia may confound evaluating EUS activity. We therefore evaluated urodynamic parameters in unanesthetized, restrained rats and compared the effects of txSCI to that of a clinically relevant, incomplete, contusive injury (iSCI) on lower urinary tract function. Adult female rats were subjected to txSCI or standardized iSCI at the T8 vertebral level. As expected, all injured rats were initially unable to void but developed a reflex bladder with time, with iSCI rats recovering more rapidly than txSCI rats. LUT function was evaluated urodynamically at 2 and 6 weeks after injury. In response to infusion of saline into the bladder, controls consistently exhibited coordinated contraction of the bladder and activation of the EUS in a phasic pattern and had a high voiding efficiency (86.4+/-2.5%). Voiding efficiency of iSCI rats was reduced to approximately 57% and txSCI rats to approximately 32%. However, two different patterns of EUS activity during voiding were present in both txSCI and iSCI groups at both time points: (1) rats with phasic EUS activity, similar to controls and (2) those that only exhibited tonic EUS activity during voiding. The former had more normal voiding efficiencies. Thus, phasic EUS activity and the improved voiding efficiency associated with it can occur and can be detected in unanesthetized rats after both incomplete and complete SCI.

The amplitude of the H-reflex increases chronically after incomplete SCI and is associated with the development of exaggerated hindlimb reflexes. Although the mechanism for this increased H-reflex is not clear, previous studies have shown that pharmacological activation of the 5-HT2 receptors (5-HT2R) can potentiate the monosynaptic reflex. This study tested the hypothesis that increased expression of 5-HT2R on motoneurons is involved in increased H-reflex amplitude after a standardized clinically relevant contusive SCI. Adult female rats were subjected to contusion, complete surgical transection, or a T8 laminectomy only. At 4 weeks after surgery, H-reflex recordings from the hindpaw plantar muscles of contused rats showed twice the amplitude of that in laminectomy controls or transected rats. To probe the role of 5-HT2R in this increased amplitude, dose-response studies were done with the selective antagonists mianserin or LY53857 and the 5-HT2R agonist (+/-)-1-(2,5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI). The drugs were intrathecally infused into the lumbar cord while recording the H-reflex. Mianserin did not have any significant effects on the H-reflex after transection, consistent with the loss of distal serotonergic innervation. After contusion, both 5-HT2R antagonists reduced the H-reflex reflex amplitude with a significantly higher ID50 compared to the uninjured controls. The 5-HT2R agonist DOI significantly increased reflex amplitude in contused but not control rats. Furthermore, while 5-HT immunoreactivity was similar, contused rats displayed increased 5-HT2AR immunoreactivity in plantar muscle motoneurons compared to uninjured controls. We conclude that increased expression of 5-HT2R is likely to be involved in the enhanced H-reflex that develops after contusive SCI.

The cathode in rechargeable lithium-ion batteries operates by conventional intercalation; Li+ is extracted from LiCoO2 on charging accompanied by oxidation of Co3+ to Co4+; the process is reversed on discharge. In contrast, Li+ may be extracted from Mn4+-based solids, e.g., Li2MnO3, without oxidation of Mn4+. A mechanism involving simultaneous Li and O removal is often proposed. Here, we demonstrate directly, by in situ differential electrochemical mass spectrometry (DEMS), that O2 is evolved from such Mn4+ -containing compounds, Li[Ni(0.2)Li(0.2)Mn(0.6)]O2, on charging and using powder neutron diffraction show that O loss from the surface is accompanied by diffusion of transition metal ions from surface to bulk where they occupy vacancies created by Li removal. The composition of the compound moves toward MO(2). Understanding such unconventional Li extraction is important because Li-Mn-Ni-O compounds, irrespective of whether they contain Co, can, after O loss, store 200 mAhg(-1) of charge compared with 140 mAhg(-1) for LiCoO(2).

The monosynaptic motoneuron response to stimulation of Ia afferents is known to be altered by spinal cord injury (SCI). Although the Hoffman (H)-reflex is a tool that is often used to measure this reflex in patients, there has not been a systematic study investigating the effect of SCI severity and time on the H-reflex. We used a clinically relevant model of spinal cord contusion (Mild and Moderate) as well as complete surgical transection to measure the H-reflex at 1, 4 and 8 weeks after injury. The H-reflex was recorded from rat hindpaw plantar muscles in order to measure the baseline reflex amplitude and its response to increased stimulus frequency, i.e. rate depression. We correlated the reflex amplitude at each frequency to spared white matter at the injury epicenter, hindlimb function and serotonin immunoreactivity associated with retrogradely labeled plantar muscle motoneurons. The three injury groups displayed different behavioral deficits and amount of spared white matter at all three times tested. H-reflex rate depression was abnormal in all three injury groups at all three time points. At 8 weeks, transected animals displayed more H-reflex rate depression than those with a mild contusion. Baseline H-reflex amplitude was increased in both contusion groups at 4 weeks and showed a positive linear correlation with serotonin immunoreactivity. This baseline amplitude was not increased after transection. Furthermore, in the contusion group, there was a U-shaped relationship between behavioral scores and H-reflex rate depression, suggesting that an intermediate sensitivity of the motoneuronal pool to afferent input is associated with better recovery of hindlimb function.

Postmenopausal women may benefit from dietary interventions in order to increase bone strength and prevent fractures. Dietary boron (B) may be beneficial for optimal calcium metabolism and, as a consequence, optimal bone metabolism. The present study evaluated the effects of boron, in the form of boric acid, with or without 17beta-estradiol (E2) supplementation (via subcutaneous implant), in ovariectomized (OVX) aged 13- mo-old F-344 rats. Boric acid was administered by gavage at a subtoxic dose (8.7 mg B/kg/d) for 40 d. Results indicate that serum level of minerals as well as osteocalcin (a marker of bone resorption) are dependent to a greater extent on the hormonal status of the animals than on boron supplementation. Boron treatment increased the E2-induced elevation of urinary calcium and magnesium. Bone mineral density (BMD) of the L5 vertebra and proximal femur was highest in the E2-treated groups; no increase in BMD was conferred by boron treatment. By histomorphometry of the proximal tibial metaphysis, osteoblastic, osteoid, and eroded surfaces were significantly suppressed by E2 treatment, but not by boron treatment. In biomechanical testing of femur and vertebra, neither E2 nor boron treatment significantly increased bone strength. At the levels given, boron alone provided no protection against OVX-induced osteopenia. In addition, combination therapy (B + E2) provided no additional benefits over those of 17beta-estradiol treatment alone in this aged rat model.

We retrieved a high-molecular-weight poly-L-lactic) (PLLA) anterior cruciate ligament (ACL) interference screw (Arthrex, Naples, FL) after 30 months in vivo during revision ACL surgery. Gross, histologic, histomorphometric, and molecular weight measurements were carried out on the implant and the surrounding bone. These studies showed a 75% decrease in the molecular weight of the screw, with implant fragmentation and new bone formation adjacent to the screw and graft. Healing of the graft within the bony tunnel with no significant inflammatory reaction had occurred. The clinical implications of these findings are that this implant dissolves slowly, and it was physically present at 30 months in vivo. It is a safe, nonreactive alternative to traditional metal interference screws used for ACL graft fixation. It will eventually be substituted by bone and will eliminate some of the problems associated with metallic devices.