Stability and Reversibility of Lithium Borohydrides Doped by Metal Halides and Hydrides

In an effort to develop reversible metal borohydrides with high hydrogen storage capacities and low dehydriding temperature, doping LiBH4 with various metal halides and hydrides has been conducted. Several metal halides such as TiCl3, TiF3, and ZnF2 effectively reduced the dehydriding temperature through a cation exchange interaction. Some of the halide doped LiBH4 are partially reversible. The LiBH4 + 0.1TiF3 desorbed 3.5 wt % and 8.5 wt % hydrogen at 150 and 450 °C, respectively, with subsequent reabsorption of 6 wt % hydrogen at 500 °C and 70 bar observed. XRD and NMR analysis of the rehydrided samples confirmed the reformation of LiBH4. The existence of the (B12H12)−2 species in dehydrided and rehydrided samples gives insight into the resultant partial reversibility. A number of other halides, MgF2, MgCl2, CaCl2, SrCl2, and FeCl3, did not reduce the dehydriding temperature of LiBH4 significantly. XRD and TGA-RGA analyses indicated that an increasing proportion of halides such as TiCl3, TiF3, and ZnCl2 from 0.1 to 0.5 mol makes lithium borohydrides less stable and volatile. Although the less stable borohydrides such as LiBH4 + 0.5TiCl3, LiBH4 + 0.5TiF3, and LiBH4 + 0.5ZnCl2 release hydrogen at room temperature, they are not reversible due to unrecoverable boron loss caused by diborane emission. In most cases, doping that produced less stable borohydrides also reduced the reversible hydrogen uptake. It was also observed that halide doping changed the melting points and reduced air sensitivity of lithium borohydrides

LUD, a new protein domain associated with lactate utilization.

BackgroundA novel highly conserved protein domain, DUF162 [Pfam: PF02589], can be mapped to two proteins: LutB and LutC. Both proteins are encoded by a highly conserved LutABC operon, which has been implicated in lactate utilization in bacteria. Based on our analysis of its sequence, structure, and recent experimental evidence reported by other groups, we hereby redefine DUF162 as the LUD domain family.ResultsJCSG solved the first crystal structure [PDB:2G40] from the LUD domain family: LutC protein, encoded by ORF DR_1909, of Deinococcus radiodurans. LutC shares features with domains in the functionally diverse ISOCOT superfamily. We have observed that the LUD domain has an increased abundance in the human gut microbiome.ConclusionsWe propose a model for the substrate and cofactor binding and regulation in LUD domain. The significance of LUD-containing proteins in the human gut microbiome, and the implication of lactate metabolism in the radiation-resistance of Deinococcus radiodurans are discussed

Two-step membrane binding by the bacterial SRP receptor enable efficient and accurate Co-translational protein targeting

The signal recognition particle (SRP) delivers ~30% of the proteome to the eukaryotic endoplasmic reticulum, or the bacterial plasma membrane. The precise mechanism by which the bacterial SRP receptor, FtsY, interacts with and is regulated at the target membrane remain unclear. Here, quantitative analysis of FtsY-lipid interactions at single-molecule resolution revealed a two-step mechanism in which FtsY initially contacts membrane via a Dynamic mode, followed by an SRP-induced conformational transition to a Stable mode that activates FtsY for downstream steps. Importantly, mutational analyses revealed extensive auto-inhibitory mechanisms that prevent free FtsY from engaging membrane in the Stable mode; an engineered FtsY pre-organized into the Stable mode led to indiscriminate targeting in vitro and disrupted FtsY function in vivo. Our results show that the two-step lipid-binding mechanism uncouples the membrane association of FtsY from its conformational activation, thus optimizing the balance between the efficiency and fidelity of co-translational protein targeting

Wide-Field Survey of Globular Clusters in M31. I. A Catalog of New Clusters

We present the result of a wide-field survey of globular clusters (GCs) in M31 covering a 3deg x 3deg field c. We have searched for GCs on CCD images taken with Washington CMT1 filters at the KPNO 0.9 m telescope using steps: (1) inspection of morphological parameters given by the SExtractor package such as stellarity, full maximum, and ellipticity; (2) consulting the spectral types and radial velocities obtained from spectra takena spectrograph at the WIYN 3.5 m telescope; and (3) visual inspection of the images of each object. We have and GC candidates, of which 605 are newly found GCs and GC candidates and 559 are previously known GCs. Amoects there are 113 genuine GCs, 258 probable GCs, and 234 possible GCs, according to our classification critee known objects there are 383 genuine GCs, 109 probable GCs, and 67 possible GCs. In total there are 496 genprobable GCs and 301 possible GCs. Most of these newly found GCs have T1 magnitudes of 17.5 - 19.5 mag, [17.9 < V < 19.9 mag assuming (C-T1) ~ 1.5], and (C-T1) colors in the range 1 - 2.Comment: accepted by AJ, using emulateapj.cl

Data-Enhanced Modeling of Sea and Swell on the Continental Shelf

LONG-TERM GOAL: Our long-term goal is to contribute to the accurate prediction of surface gravity wave generation, propagation, and dissipation in coastal regions through the combined use of measurements and models.Award #s: N00014-98-1-0019; N0001499WX30036; N0001499WR3000

Phase 2 Study of Anti-Human Cytomegalovirus Monoclonal Antibodies for Prophylaxis in Hematopoietic Cell Transplantation.

Human cytomegalovirus (HCMV) can cause significant disease in immunocompromised patients, and treatment options are limited by toxicities. CSJ148 is a combination of two anti-HCMV human monoclonal antibodies (LJP538 and LJP539) that bind to and inhibit the functions of viral HCMV glycoprotein B (gB) and the pentameric complex, consisting of glycoproteins gH, gL, UL128, UL130, and UL131. In this phase 2, randomized, placebo-controlled trial, we evaluated the safety and efficacy of CSJ148 for prophylaxis of HCMV in patients undergoing allogeneic hematopoietic stem cell transplantation. As would be expected in the study population, all the patients (100%) reported at least one treatment-emergent adverse event. There were 22 deaths during this study, and over 80% of the patients receiving placebo or CSJ148 developed at least one adverse event of grade 3 or higher severity. No subject who received antibody developed a hypersensitivity- or infusion-related reaction. CSJ148-treated patients showed trends toward decreased viral load, shorter median duration of preemptive therapy, and fewer courses of preemptive therapy. However, the estimated probability that CSJ148 decreases the need for preemptive therapy compared to placebo was 69%, with a risk ratio of 0.89 and a 90% credible interval of 0.61 to 1.31. The primary efficacy endpoint was therefore not met, indicating that CSJ148 did not prevent clinically significant HCMV reactivation in recipients of allogeneic hematopoietic cell transplants. (This study has been registered at ClinicalTrials.gov under identifier NCT02268526 and at EudraCT under number 2017-002047-15.)

A Comparative Study of the ReCell® Device and Autologous Spit-Thickness Meshed Skin Graft in the Treatment of Acute Burn Injuries.

Early excision and autografting are standard care for deeper burns. However, donor sites are a source of significant morbidity. To address this, the ReCell® Autologous Cell Harvesting Device (ReCell) was designed for use at the point-of-care to prepare a noncultured, autologous skin cell suspension (ASCS) capable of epidermal regeneration using minimal donor skin. A prospective study was conducted to evaluate the clinical performance of ReCell vs meshed split-thickness skin grafts (STSG, Control) for the treatment of deep partial-thickness burns. Effectiveness measures were assessed to 1 year for both ASCS and Control treatment sites and donor sites, including the incidence of healing, scarring, and pain. At 4 weeks, 98% of the ASCS-treated sites were healed compared with 100% of the Controls. Pain and assessments of scarring at the treatment sites were reported to be similar between groups. Significant differences were observed between ReCell and Control donor sites. The mean ReCell donor area was approximately 40 times smaller than that of the Control (P &lt; .0001), and after 1 week, significantly more ReCell donor sites were healed than Controls (P = .04). Over the first 16 weeks, patients reported significantly less pain at the ReCell donor sites compared with Controls (P ≤ .05 at each time point). Long-term patients reported higher satisfaction with ReCell donor site outcomes compared with the Controls. This study provides evidence that the treatment of deep partial-thickness burns with ASCS results in comparable healing, with significantly reduced donor site size and pain and improved appearance relative to STSG

Crepuscular Rays from the Highly Inclined Active Galactic Nucleus in IC 5063

On Earth near sunset, the sun may cast "crepuscular rays" such that clouds near the horizon obscure the origin of light scattered in bright rays. In principle, AGN should be able to produce similar effects. Using new Hubble Space Telescope (HST) near-infrared and optical observations, we show that the active galaxy IC 5063 contains broad radial rays extending to $\gtrsim$11 kpc from the nucleus. We argue that the bright rays may arise from dusty scattering of continuum emission from the active nucleus, while the dark rays are due to shadowing near the nucleus, possibly by a warped torus. We also consider alternative AGN-related and stellar origins for the extended light.Comment: Accepted for publication to ApJ Letters. 13 pages, 5 figures. Facilitated by Twitter discussion (see https://twitter.com/SpaceGeck/status/1201350966945017856). This version corrects figure labels and includes other more minor update

Muon Spin Relaxation Study of (La, Ca)MnO3

We report predominantly zero field muon spin relaxation measurements in a series of Ca-doped LaMnO_3 compounds which includes the colossal magnetoresistive manganites. Our principal result is a systematic study of the spin-lattice relaxation rates 1/T_1 and magnetic order parameters in the series La_{1-x}Ca_xMnO_3, x = 0.0, 0.06, 0.18, 0.33, 0.67 and 1.0. In LaMnO_3 and CaMnO_3 we find very narrow critical regions near the Neel temperatures T_N and temperature independent 1/T_1 values above T_N. From the 1/T_1 in LaMnO_3 we derive an exchange integral J = 0.83 meV which is consistent with the mean field expression for T_N. All of the doped manganites except CaMnO_3 display anomalously slow, spatially inhomogeneous spin-lattice relaxation below their ordering temperatures. In the ferromagnetic (FM) insulating La_{0.82}Ca_{0.18}MnO_3 and ferromagnetic conducting La_{0.67}Ca_{0.33}MnO_3 systems we show that there exists a bi-modal distribution of \muSR rates \lambda_f and \lambda_s associated with relatively 'fast' and 'slow' Mn fluctuation rates, respectively. A physical picture is hypothesized for these FM phases in which the fast Mn rates are due to overdamped spin waves characteristic of a disordered FM, and the slower Mn relaxation rates derive from distinct, relatively insulating regions in the sample. Finally, likely muon sites are identified, and evidence for muon diffusion in these materials is discussed.Comment: 21 pages, 17 figure