Vibrational spectra and normal coordinate analysis of neptunium (IV) borohydride and neptunium (IV) borodeuteride

Solid state, low temperature IR (25-7400 cm{sup -1}) and Raman (100-2600 cm{sup -1}) spectra were obtained for Np(BH{sub 4}){sub 4} and Np(BD{sub 4}){sub 4} from which most of the allowed fundamentals were assigned based on the T{sub d} molecular structure. Those assignments were used in a normal coordinate analysis to derive a simple force field using 8 primary and 5 interaction constants. This field is very similar to those found for Zr(BH{sb 4}){sub 4} and Hf(BH{sub 4}){sub 4}. Isotopic impurity, overtone, and combination bands were identified in the IR spectra with the help of the normal coordinate calculations. Near IR spectra of Zr(BH{sub 4}){sub 4} and Zr(BD{sub 4}({sub 4} were taken in the range 7400-4000 cm{sup -1} and the observed absorption bands were assigned as either overtone or combination levels

Bilateral Distal Radius Fractures in a 12-Year-Old Boy after Household Electrical Shock: Case Report and Literature Summary

Background. Fracture resulting from household electric shock is uncommon. When it occurs, it is usually the result of a fall; however, electricity itself can cause sufficient tetany to produce a fracture. We present the case of bilateral fractures of the distal radii of a 12-year-old boy which were sustained after accidental shock. The literature regarding fractures after domestic electric shock is also reviewed. Methods. An Ovid-Medline search was conducted. The resultant articles and their bibliographies were surveyed for cases describing fractures resulting from a typical household-level voltage (110–220 V, 50–60 Hertz) and not a fall after the shock. Twenty-one articles describing 22 patients were identified. Results. Twenty-two cases were identified. Thirteen were unilateral injuries; 9 were bilateral. Proximal humerus fractures were most frequent (8 cases), followed by scapula fractures (7 cases), forearm fractures (4 cases), femoral neck fractures (2 cases), and vertebral body fracture (1 case). Eight of the 22 cases were diagnosed days to weeks after the injury. Conclusions. Fracture after electric shock is uncommon. It should be suspected in patients with persistent pain, particularly in the shoulder or forearm area. Distal radius fractures that occur during electrocution are likely due to tetany

Research Program to Investigate the Fundamental Chemistry of Technetium

Technetium (99Tc, half-life = 2.13x105 years, b-emitter) is one of the radionuclides of major concern for nuclear waste disposal. This concern is due to the long half-life of 99Tc, the ease with which pertechnetate, TcO4 -, migrates in the geosphere, and the corresponding regulatory considerations. The problem of mobility of pertechnetate in the environment is compounded by the fact that pertechnetate is the thermodynamically stable form of technetium in aerobic environments. These two factors present challenges for the safe, long term immobilization of technetium in waste forms. Because of the stability of pertechnetate, technetium has been assumed to exist as pertechnetate in the aqueous phase of nuclear waste tanks. However, recent studies indicate that a significant fraction of the technetium is in a different chemical form. This program addresses the fundamental solution chemistry of technetium in the waste tank environment, and in a second part, the stability of technetium in various waste forms. The chemistry of this element will be studied in aqueous solutions at high pH, with various added salts such as nitrate, nitrite, and organic complexants, and as a function of radiation dose, to determine whether radiolysis effects can reduce TcO4 -. A separate facet of this research is the search for chemical forms of technetium that may be thermodynamically and/or kinetically stable and may be incorporated in various waste forms for long term storage. This phase of the program will address the problem of the possible oxidation of lower valent technetium species in various waste form matrices and the subsequent leaching of the highly soluble TcO4 -

Circadian Integration of Glutamatergic Signals by Little SAAS in Novel Suprachiasmatic Circuits

Neuropeptides are critical integrative elements within the central circadian clock in the suprachiasmatic nucleus (SCN), where they mediate both cell-to-cell synchronization and phase adjustments that cause light entrainment. Forward peptidomics identified little SAAS, derived from the proSAAS prohormone, among novel SCN peptides, but its role in the SCN is poorly understood.Little SAAS localization and co-expression with established SCN neuropeptides were evaluated by immunohistochemistry using highly specific antisera and stereological analysis. Functional context was assessed relative to c-FOS induction in light-stimulated animals and on neuronal circadian rhythms in glutamate-stimulated brain slices. We found that little SAAS-expressing neurons comprise the third most abundant neuropeptidergic class (16.4%) with unusual functional circuit contexts. Little SAAS is localized within the densely retinorecipient central SCN of both rat and mouse, but not the retinohypothalamic tract (RHT). Some little SAAS colocalizes with vasoactive intestinal polypeptide (VIP) or gastrin-releasing peptide (GRP), known mediators of light signals, but not arginine vasopressin (AVP). Nearly 50% of little SAAS neurons express c-FOS in response to light exposure in early night. Blockade of signals that relay light information, via NMDA receptors or VIP- and GRP-cognate receptors, has no effect on phase delays of circadian rhythms induced by little SAAS.Little SAAS relays signals downstream of light/glutamatergic signaling from eye to SCN, and independent of VIP and GRP action. These findings suggest that little SAAS forms a third SCN neuropeptidergic system, processing light information and activating phase-shifts within novel circuits of the central circadian clock

Synchronous long-term oscillations in a synthetic gene circuit.

Synthetically engineered genetic circuits can perform a wide variety of tasks but are generally less accurate than natural systems. Here we revisit the first synthetic genetic oscillator, the repressilator, and modify it using principles from stochastic chemistry in single cells. Specifically, we sought to reduce error propagation and information losses, not by adding control loops, but by simply removing existing features. We show that this modification created highly regular and robust oscillations. Furthermore, some streamlined circuits kept 14 generation periods over a range of growth conditions and kept phase for hundreds of generations in single cells, allowing cells in flasks and colonies to oscillate synchronously without any coupling between them. Our results suggest that even the simplest synthetic genetic networks can achieve a precision that rivals natural systems, and emphasize the importance of noise analyses for circuit design in synthetic biology.Some work was performed at the Harvard Medical School Microfluidics Facility and the Center for Nanoscale Systems, a member of the National Nanotechnology Infrastructure Network supported by NSF award ECS-0335765. LPT acknowledges fellowship support from the Natural Sciences and Engineering Research Council of Canada (NSERC) and the Fonds de recherche du Québec – Nature et technologies. This work was supported by NIH Grant GM095784 and NSF Award 1137676.This is the author accepted manuscript. The final version is available from Nature via https://www.nature.com/nature/journal/v538/n7626/full/nature19841.htm

Reanalysis of the Aqueous Spectrum of the Neptunyl(V) [NpO2(+)] Ion.

The actinyl ions, consisting of the dioxoactinde(VI) and dioxoactinide(V) ions, are unique in the periodic table. However, very few quantitative studies of the spectra of these ions have been performed. In this paper the analysis of the optical spectrum of the aqueous neptunyl(V) [NpO2(+)] ion in 1 M HClO4 is reexamined. The species in solution is assumed to be the linear NpO2(+) ion surrounded in the equatorial plane by five oxygen atoms from five H2O molecules. The neptunyl(V) ion has the 5f(2) open-shell configuration, and the low-lying optical transitions (up to ∼20 000 cm(-1)) observed are primarily from the two 5f electrons occupying the 5fφ and 5fδ orbitals. The conventional parametric theory used for f(n) systems is applied to these low-lying transitions utilizing the intensity calculations that Matiska et al.1 have performed for this ion and the data reported by Eisenstein and Pryce.2 Possible ratios for the Slater electrostatic repulsion parameters are obtained from the data for the isoelectronic ion U(4+) (5f(2)) in various host crystals. The results are consistent with earlier crystal field analyses of the 5f(1) neptunyl(VI) [NpO2(2+)] ion