We present measurements of Stark interference in the (61)S(0)→6(3)P(1) transition in (199)Hg, a process whereby a static electric field E mixes magnetic dipole and electric quadrupole couplings into an electric dipole transition, leading to E-linear energy shifts similar to those produced by a permanent atomic electric dipole moment (EDM). The measured interference amplitude, a(SI) = (a(M1) + a(E2)) = (5.8 ± 1.
View Article and Find Full Text PDFThis study aims to examine resource utilization and outcomes of trauma patients with extremely high blood alcohol concentrations. We hypothesized that higher blood alcohol concentration (BAC) predicts greater resource utilization and poorer outcomes. A retrospective analysis was performed on trauma patients admitted to an urban Level I trauma center over a 5-year period.
View Article and Find Full Text PDFBackground: Patients referred to trauma centers often undergo an extensive diagnostic work-up before transfer. The purpose of our study was to quantify and examine the effects of repeat imaging in this population.
Methods: A prospective cohort study of 410 patient transfers was performed.
Purpose: To determine which internal medicine (IM) clerkship characteristics are associated with better student examination performance.
Method: The authors collected data from 17 U.S.
We report the results of a new experimental search for a permanent electric dipole moment of 199Hg utilizing a stack of four vapor cells. We find d(199Hg)=(0.49+/-1.
View Article and Find Full Text PDFWe report a three-channel, spectrally beam-combined (SBC), 1 mum fiber laser that produces 522 W of average power with near-diffraction-limited (M2 ~ 1.2) beam quality. The laser features a SBC power combining efficiency of 93%, versatile master-oscillator, power-amplifier fiber channels with up to 260 W of narrow-band, polarized, and near-diffraction-limited output that is tunable over nearly the entire 1 micro m Yb(3+) gain bandwidth, and excellent prospects for significant power scaling.
View Article and Find Full Text PDFBackground: The application of indirect reduction techniques has improved fracture-healing and reduced the need for bone-grafting compared with the outcomes of older, direct reduction techniques. We investigated the results of such indirect reduction techniques for the treatment of periprosthetic femoral shaft fractures.
Methods: Fifty consecutive patients with a femoral shaft fracture about a stable intramedullary implant (a Vancouver Type-B1 fracture) were treated with a protocol that included open reduction with use of indirect reduction techniques and internal fixation with a single lateral plate without structural allografting or other bone-grafting.
Physicians play an increasingly important role in the critical medical process of aeromedical evacuation (AE). Incomplete or inappropriate preparation for AE can result in increased patient discomfort, and in the worst cases, potentially serious or insurmountable in-flight medical problems. During military operations and in response to natural disasters, physicians are responsible for four processes necessary for a successful AE mission.
View Article and Find Full Text PDFObjective: New locked plate devices offer theoretical advantages for the treatment of supracondylar femur fractures associated with a total knee arthroplasty (TKA). These devices also can be inserted with relative ease by using minimally invasive techniques, provide a fixed angle construct, and improve fixation in osteoporotic bone. The purpose of this study was to evaluate the results and complications of treating periprosthetic supracondylar femur fractures above a TKA with a locked plate designed for the distal femur.
View Article and Find Full Text PDFBackground: The application of indirect reduction techniques has improved fracture-healing and reduced the need for bone-grafting compared with the outcomes of older, direct reduction techniques. We investigated the results of such indirect reduction techniques for the treatment of periprosthetic femoral shaft fractures.
Methods: Fifty consecutive patients with a femoral shaft fracture about a stable intramedullary implant (a Vancouver Type-B1 fracture) were treated with a protocol that included open reduction with use of indirect reduction techniques and internal fixation with a single lateral plate without structural allografting or other bone-grafting.
By varying the density of an ultracold 88Sr sample from 10(9) to>10(12) cm(-3), we make the first definitive measurement of the density-related frequency shift and linewidth broadening of the 1S0-3P1 optical clock transition in an alkaline earth system. In addition, we report the most accurate measurement to date of the 88Sr 1S0-3P1 optical clock transition frequency. Including a detailed analysis of systematic errors, the frequency is [434 829 121 312 334+/-20(stat)+/-33(syst)] Hz.
View Article and Find Full Text PDFWe present an extensive study of the unique thermal and mechanical dynamics for narrow-line cooling on the 1S0-3P1 88Sr transition. For negative detuning, trap dynamics reveal a transition from the semiclassical regime to the photon-recoil-dominated quantum regime, yielding an absolute minima in the equilibrium temperature below the single-photon-recoil limit. For positive detuning, the cloud divides into discrete momentum packets whose alignment mimics lattice points on a face-centered-cubic crystal.
View Article and Find Full Text PDFThe effects of a series of 102 bisphosphonates on the inhibition of growth of Entamoeba histolytica and Plasmodium falciparum in vitro have been determined, and selected compounds were further investigated for their in vivo activity. Forty-seven compounds tested were active (IC(50) < 200 microM) versus E. histolytica growth in vitro.
View Article and Find Full Text PDFWe report the first experimental study of sub-Doppler cooling in alkaline earth atoms (87Sr) enabled by the presence of nuclear spin-originated magnetic degeneracy in the atomic ground state. Sub-Doppler cooling in a sigma(+)-sigma(-) configuration is achieved despite the presence of multiple, closely spaced excited states. This surprising result is confirmed by an expanded multilevel theory of the radiative cooling force.
View Article and Find Full Text PDFBackground: The abuse of medical students on clinical rotations is a recognized problem, but the effects on students and their responses warrant further study.
Purpose: To determine the severity of student abuse and the effects of abuse on students during the internal medicine clerkship.
Methods: Internal medicine clerks at 11 medical schools (N = 1,072) completed an exit survey.
We report the inhibition of a human recombinant geranylgeranyl diphosphate synthase (GGPPSase) by 23 bisphosphonates and six azaprenyl diphosphates. The IC50 values range from 140 nM to 690 microM. None of the nitrogen-containing bisphosphonates that inhibit farnesyl diphosphate synthase were effective in inhibiting the GGPPSase enzyme.
View Article and Find Full Text PDFWe have loaded an ultracold gas of fermionic atoms into a far-off resonance optical dipole trap and precisely controlled the spin composition of the trapped gas. We have measured a magnetic-field Feshbach resonance between atoms in the two lowest energy spin states, /9/2,-9/2> and /9/2,-7/2>. The resonance peaks at a magnetic field of 201.
View Article and Find Full Text PDFPhys Rev Lett
December 2001
We study the interaction of pulsed excitation fields with optically thin atomic ensembles subject to strong cavity-accelerated superradiance. In homogeneously broadened atom-field systems the excitation of superradiant instabilities is seen to lead to a quantization of the total pulse area accrued during excitation and subsequent superradiant decay. In inhomogeneously broadened systems, quasidiscretized area values and pulse area gaps (i.
View Article and Find Full Text PDFA new series of cosalane analogues incorporating two fragments of the dichlorodisalicylmethane pharmacophore has been synthesized. In order to identify the position for the attachment of the pharmacophore fragments to the steroid ring that results in the most potent analogues, two types of compounds were designed. In the first type, the two pharmacophore fragments were attached at C-3 and C-17 of the steroid ring by using appropriate linker units.
View Article and Find Full Text PDFThe Cache River of southernmost Illinois is used as a case study for developing and demonstrating an approach to quantitatively link (1) national agricultural policy and global agricultural markets, (2) landowner's decisions on land use, (3) spatial patterns of land use at a watershed scale, and (4) hydrologic impacts, thus providing a basis to predict, under a certain set of circumstances, the environmental consequences of economic and political decisions made at larger spatial scales. The heart of the analysis is an estimation, using logistic regression, of the affect of crop prices and Conservation Reserve Program (CRP) rental rates on farmland owner's decisions whether to reenroll in the CRP or return to crop production. This analysis shows that reasonable ranges for crop prices (80%-150% of 1985-1995 values) and CRP rental rates (0-125% of 1985-1995 rates) result in a range of 3%-92% of CRP lands being returned to crop production, with crop prices having a slightly greater effect than CRP rental rates.
View Article and Find Full Text PDFThe Sonogashira and Stille cross-coupling reactions have been employed in the synthesis of several non-nucleoside reverse transcriptase inhibitors (NNRTIs) in the alkenyldiarylmethane (ADAM) series. The synthesis has been carried out both in solution and on a solid support. In contrast to previous syntheses of NNRTIs in the ADAM series, the present strategy allows the incorporation of differently substituted aromatic rings in a stereochemically defined fashion.
View Article and Find Full Text PDFCosalane and its synthetic derivatives inhibit the binding of gp120 to CD4 as well as the fusion of the viral envelope with the cell membrane. The binding of the cosalanes to CD4 is proposed to involve ionic interactions of the negatively charged carboxylates of the ligands with positively charged arginine and lysine amino acid side chains of the protein. To investigate the effect of anion spacing on anti-HIV activity in the cosalane system, a series of cosalane tetracarboxylates was synthesized in which the two proximal and two distal carboxylates are separated by 6--12 atoms.
View Article and Find Full Text PDFWe have identified and characterized a potent new nonnucleoside reverse transcriptase (RT) inhibitor (NNRTI) of human immunodeficiency virus type 1 (HIV-1) that also is active against HIV-2 and which interferes with virus replication by two distinct mechanisms. 1-(3-Cyclopenten-1-yl)methyl-6-(3,5-dimethylbenzoyl)-5-ethyl-2,4-pyrimidinedione (SJ-3366) inhibits HIV-1 replication at concentrations of approximately 1 nM, with a therapeutic index of greater than 4 x 10(6). The efficacy and toxicity of SJ-3366 are consistent when evaluated with established or fresh human cells, and the compound is equipotent against all strains of HIV-1 evaluated, including syncytium-inducing, non-syncytium-inducing, monocyte/macrophage-tropic, and subtype virus strains.
View Article and Find Full Text PDFJ Res Natl Inst Stand Technol
August 2016
A method for calibrating iodine-125 seeds in terms of exposure has been established. The standard free-air ionization chamber, used for measuring soft x rays, was chosen for the measurements. Arrays of four to six seeds were used to enhance the ionization-current-to-background-current ratio.
View Article and Find Full Text PDFThe binding of the anti-HIV agent cosalane to CD4 is thought to involve ionic interactions of negatively charged carboxylates of the ligand with positively charged residues on the surface of the protein. The purpose of the present study was to examine the hypothesis that the two carboxyl groups of cosalane could be sacrificed through conjugation to amino acids, and the anti-HIV activity still be retained, provided that at least two new carboxyl groups are contributed by the amino acid residues.
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