The Emerging Role of the Insulin-like Growth Factors in Oral Biology

The insulin-like growth factors (IGF) are a family of growth factors, receptors and binding proteins that are involved in numerous growth and differentiation processes, as well as in various pathological conditions. The aim of this review is to summarize data that has been accumulating in recent years linking the IGF system to a number of physiological and pathological oral processes. The IGF system fulfills an important role in growth and development of teeth, mandible, maxillae, and tongue. It has been postulated that IGF-I may be of great value in the treatment of periodontal defects and in tissue healing. Furthermore, IGF-II has been shown to be overexpressed in salivary gland adenomas, suggesting that aberrant IGF signaling may be a key factor in the etiology of oral malignancies. Understanding the role and regulation of IGF system components in salivary glands and other oral structures will be of significant basic and clinical relevance.

Experimental Investigation of the Collective Raman Scattering of Multiple Laser Beams in Inhomogeneous Plasmas

Experiments have been performed evidencing significant stimulated Raman sidescattering (SRS) at large angles from the density gradient. This was achieved in long scale-length high-temperature plasmas in which two beams couple to the same scattered electromagnetic wave further demonstrating for the first time this multiple-beam collective SRS interaction. The collective nature of the coupling and the amplification at large angles from the density gradient increase the global SRS losses and produce light scattered in novel directions out of the planes of incidence of the beams. These findings obtained in plasmas conditions relevant of inertial confinement fusion experiments similarly apply to the more complex geometry of these experiments where anomalously large levels of SRS were measured.

Plasma characterization using ultraviolet Thomson scattering from ion-acoustic and electron plasma waves (invited)

Collective Thomson scattering is a technique for measuring the plasma conditions in laser-plasma experiments. Simultaneous measurements of ion-acoustic and electron plasma-wave spectra were obtained using a 263.25-nm Thomson-scattering probe beam. A fully reflective collection system was used to record light scattered from electron plasma waves at electron densities greater than 10²¹ cm^-3, which produced scattering peaks near 200 nm. An accurate analysis of the experimental Thomson-scattering spectra required accounting for plasma gradients, instrument sensitivity, optical effects, and background radiation. Practical techniques for including these effects when fitting Thomson-scattering spectra are presented and applied to the measured spectra to show the improvements in plasma characterization.

Simulated performance of the optical Thomson scattering diagnostic designed for the National Ignition Facility

An optical Thomson scattering diagnostic has been designed for the National Ignition Facility to characterize under-dense plasmas. We report on the design of the system and the expected performance for different target configurations. The diagnostic is designed to spatially and temporally resolve the Thomson scattered light from laser driven targets. The diagnostic will collect scattered light from a 50 × 50 × 200 μm volume. The optical design allows operation with different probe laser wavelengths. A deep-UV probe beam (λ₀ = 210 nm) will be used to Thomson scatter from electron plasma densities of ∼5 × 10²⁰ cm^-3 while a 3ω probe will be used for plasma densities of ∼1 × 10¹⁹ cm^-3. The diagnostic package contains two spectrometers: the first to resolve Thomson scattering from ion acoustic wave fluctuations and the second to resolve scattering from electron plasma wave fluctuations. Expected signal levels relative to background will be presented for typical target configurations (hohlraums and a planar foil).

The design of the optical Thomson scattering diagnostic for the National Ignition Facility

The National Ignition Facility (NIF) is a 192 laser beam facility designed to support the Stockpile Stewardship, High Energy Density and Inertial Confinement Fusion (ICF) programs. We report on the design of an Optical Thomson Scattering (OTS) diagnostic that has the potential to transform the community's understanding of NIF hohlraum physics by providing first principle, local, time-resolved measurements of under-dense plasma conditions. The system design allows operation with different probe laser wavelengths by manual selection of the appropriate beam splitter and gratings before the shot. A deep-UV probe beam (λ₀-210 nm) will be used to optimize the scattered signal for plasma densities of 5 × 10²⁰ electrons/cm³ while a 3ω probe will be used for experiments investigating lower density plasmas of 1 × 10¹⁹ electrons/cm³. We report the phase I design of a two phase design strategy. Phase I includes the OTS telescope, spectrometer, and streak camera; these will be used to assess the background levels at NIF. Phase II will include the design and installation of a probe laser.

A Particle X-ray Temporal Diagnostic (PXTD) for studies of kinetic, multi-ion effects, and ion-electron equilibration rates in Inertial Confinement Fusion plasmas at OMEGA (invited)

A Particle X-ray Temporal Diagnostic (PXTD) has been implemented on OMEGA for simultaneous time-resolved measurements of several nuclear products as well as the x-ray continuum produced in High Energy Density Plasmas and Inertial Confinement Fusion implosions. The PXTD removes systematic timing uncertainties typically introduced by using multiple instruments, and it has been used to measure DD, DT, D³He, and T³He reaction histories and the emission history of the x-ray core continuum with relative timing uncertainties within ±10-20 ps. This enables, for the first time, accurate and simultaneous measurements of the x-ray emission histories, nuclear reaction histories, their time differences, and measurements of T_i(t) and T_e(t) from which an assessment of multiple-ion-fluid effects, kinetic effects during the shock-burn phase, and ion-electron equilibration rates can be made.

A pulse-front-tilt-compensated streaked optical spectrometer with high throughput and picosecond time resolution

A high-throughput, broadband optical spectrometer coupled to the Rochester optical streak system equipped with a Photonis P820 streak tube was designed to record time-resolved spectra with 1-ps time resolution. Spectral resolution of 0.8 nm is achieved over a wavelength coverage range of 480 to 580 nm, using a 300-groove/mm diffraction grating in conjunction with a pair of 225-mm-focal-length doublets operating at an f/2.9 aperture. Overall pulse-front tilt across the beam diameter generated by the diffraction grating is reduced by preferentially delaying discrete segments of the collimated input beam using a 34-element reflective echelon optic. The introduced delay temporally aligns the beam segments and the net pulse-front tilt is limited to the accumulation across an individual sub-element. The resulting spectrometer design balances resolving power and pulse-front tilt while maintaining high throughput.

Similar white matter but opposite grey matter changes in schizophrenia and high-functioning autism

OBJECTIVE

High-functioning autism (HFA) and schizophrenia (SZ) are two of the main neurodevelopmental disorders, sharing several clinical dimensions and risk factors. Their exact relationship is poorly understood, and few studies have directly compared both disorders. Our aim was thus to directly compare neuroanatomy of HFA and SZ using a multimodal MRI design.

METHODS

We scanned 79 male adult subjects with 3T MRI (23 with HFA, 24 with SZ and 32 healthy controls, with similar non-verbal IQ). We compared them using both diffusion-based whole-brain tractography and T1 voxel-based morphometry.

RESULTS

HFA and SZ groups exhibited similar white matter alterations in the left fronto-occipital inferior fasciculus with a decrease in generalized fractional anisotropy compared with controls. In grey matter, the HFA group demonstrated bilateral prefrontal and anterior cingulate increases in contrast with prefrontal and left temporal reductions in SZ.

CONCLUSION

HFA and SZ may share common white matter deficits in long-range connections involved in social functions, but opposite grey matter abnormalities in frontal regions that subserve complex cognitive functions. Our results are consistent with the fronto-occipital underconnectivity theory of HFA and the altered connectivity hypothesis of SZ and suggest the existence of both associated and diametrical liabilities to these two conditions.

Experimental Evidence of the Collective Brillouin Scattering of Multiple Laser Beams Sharing Acoustic Waves

The indirect-drive scheme to inertial confinement fusion uses a large number of laser beams arranged in a symmetric angular distribution. Collective laser plasma instabilities can therefore develop that couple all the incident laser waves located in a cone to the daughter wave growing along the cone symmetry axis [D. F. DuBois et al., Phys. Fluids B 4, 241 (1992)]. With complementary diagnostics of Thomson scattering and of the scattered light, we demonstrate the occurrence of collective stimulated Brillouin sidescattering driving collective acoustic waves in indirect-drive experiments.

Neutron temporal diagnostic for high-yield deuterium-tritium cryogenic implosions on OMEGA

A next-generation neutron temporal diagnostic (NTD) capable of recording high-quality data for the highest anticipated yield cryogenic deuterium-tritium (DT) implosion experiments was recently installed at the Omega Laser Facility. A high-quality measurement of the neutron production width is required to determine the hot-spot pressure achieved in inertial confinement fusion experiments-a key metric in assessing the quality of these implosions. The design of this NTD is based on a fast-rise-time plastic scintillator, which converts the neutron kinetic energy to 350- to 450-nm-wavelength light. The light from the scintillator inside the nose-cone assembly is relayed ∼16 m to a streak camera in a well-shielded location. An ∼200× reduction in neutron background was observed during the first high-yield DT cryogenic implosions compared to the current NTD installation on OMEGA. An impulse response of ∼40 ± 10 ps was measured in a dedicated experiment using hard x-rays from a planar target irradiated with a 10-ps short pulse from the OMEGA EP laser. The measured instrument response includes contributions from the scintillator rise time, optical relay, and streak camera.

A picosecond beam-timing system for the OMEGA laser

A timing system is demonstrated for the OMEGA Laser System that guarantees all 60 beams will arrive on target simultaneously with a root mean square variability of 4 ps. The system relies on placing a scattering sphere at the target position to couple the ultraviolet light from each beam into a single photodetector.

Two-Plasmon Decay Mitigation in Direct-Drive Inertial-Confinement-Fusion Experiments Using Multilayer Targets

Multilayer direct-drive inertial-confinement-fusion targets are shown to significantly reduce two-plasmon decay (TPD) driven hot-electron production while maintaining high hydrodynamic efficiency. Implosion experiments on the OMEGA laser used targets with silicon layered between an inner beryllium and outer silicon-doped plastic ablator. A factor-of-5 reduction in hot-electron generation (>50  keV) was observed in the multilayer targets relative to pure CH targets. Three-dimensional simulations of the TPD-driven hot-electron production using a laser-plasma interaction code (lpse) that includes nonlinear and kinetic effects show good agreement with the measurements. The simulations suggest that the reduction in hot-electron production observed in the multilayer targets is primarily caused by increased electron-ion collisional damping.

Direct observation of the two-plasmon-decay common plasma wave using ultraviolet Thomson scattering

A 263-nm Thomson-scattering beam was used to directly probe two-plasmon-decay (TPD) excited electron plasma waves (EPWs) driven by between two and five 351-nm beams on the OMEGA Laser System. The amplitude of these waves was nearly independent of the number of drive beams at constant overlapped intensity, showing that the observed EPWs are common to the multiple beams. In an experimental configuration where the Thomson-scattering diagnostic was not wave matched to the common TPD EPWs, a broad spectrum of TPD-driven EPWs was observed, indicative of nonlinear effects associated with TPD saturation. Electron plasma waves corresponding to Langmuir decay of TPD EPWs were observed in both Thomson-scattering spectra, suggesting the Langmuir decay instability as a TPD saturation mechanism. Simulated Thomson-scattering spectra from three-dimensional numerical solutions of the extended Zakharov equations of TPD are in excellent agreement with the experimental spectra and verify the presence of the Langmuir decay instability.

Continuous regional anaesthesia provides effective pain management and reduces opioid requirement following major lower limb amputation

OBJECTIVES

Postoperative stump pain after major lower limb amputation is a significant impediment to the recovery of amputees. The vast majority of patients require opioid analgesics following surgery, which are associated with opioid-related side-effects. Here, we investigate whether intraoperative placement of a peripheral nerve stump catheter followed by continuous infusion of local anesthetic is as effective at pain control as current analgesic practices. If beneficial, this procedure could potentially reduce post-amputation opioid consumption and opioid-related adverse effects.

METHODS

A retrospective chart review was conducted of 198 patients over a 4-year period who had undergone a major lower limb amputation for indications related to peripheral vascular disease. Postoperatively, 102 patients received a perineural catheter were compared to 96 patients who did not. The primary outcomes of this study were the amount of morphine equivalents used in the first 72 hours postoperatively and postoperative pain intensity in the first 24 hours.

RESULTS

A total of 198 lower-limb amputations were selected for analyses. Multiple regression analyses indicated that perineural catheter use was associated with a lower cumulative postoperative opioid consumption over the first 72 hours but not postoperative pain scores at 24 hours. Perineural catheter use led to a 40% reduction in opioid use during the first 72 hours postoperatively. Mixed model repeated measures analysis demonstrated that this opioid reduction was consistent over time. Other variables related to total opioid use included age, pre-surgical chronic pain, pre-surgical opioid use, patient-controlled analgesia.

CONCLUSIONS

Continuous perineural infusions of local anesthetic are a safe and effective method for reducing post-amputation opioid analgesic medications after major lower limp amputation.